sys/net/sppp/if_spppsubr.c

root/sys/net/sppp/if_spppsubr.c
/*
 * Synchronous PPP/Cisco link level subroutines.
 * Keepalive protocol implemented in both Cisco and PPP modes.
 *
 * Copyright (C) 1994-1996 Cronyx Engineering Ltd.
 * Author: Serge Vakulenko, <vak@cronyx.ru>
 *
 * Heavily revamped to conform to RFC 1661.
 * Copyright (C) 1997, 2001 Joerg Wunsch.
 *
 * This software is distributed with NO WARRANTIES, not even the implied
 * warranties for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 *
 * Authors grant any other persons or organisations permission to use
 * or modify this software as long as this message is kept with the software,
 * all derivative works or modified versions.
 *
 * From: Version 2.4, Thu Apr 30 17:17:21 MSD 1997
 *
 * $FreeBSD: src/sys/net/if_spppsubr.c,v 1.59.2.13 2002/07/03 15:44:41 joerg Exp $
 */

#include <sys/param.h>
#include <sys/libkern.h>

#include "opt_inet.h"
#include "opt_inet6.h"

#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/sockio.h>
#include <sys/socket.h>
#include <sys/syslog.h>
#include <sys/random.h>
#include <sys/thread2.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/md5.h>

#include <net/if.h>
#include <net/ifq_var.h>
#include <net/netisr.h>
#include <net/if_types.h>
#include <net/route.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <net/slcompress.h>

#include <machine/stdarg.h>

#include <netinet/in_var.h>

#ifdef INET
#include <netinet/tcp.h>
#endif

#include <netinet/if_ether.h>

#include "if_sppp.h"

#define IOCTL_CMD_T     u_long
#define MAXALIVECNT     3               /* max. alive packets */

/*
 * Interface flags that can be set in an ifconfig command.
 *
 * Setting link0 will make the link passive, i.e. it will be marked
 * as being administrative openable, but won't be opened to begin
 * with.  Incoming calls will be answered, or subsequent calls with
 * -link1 will cause the administrative open of the LCP layer.
 *
 * Setting link1 will cause the link to auto-dial only as packets
 * arrive to be sent.
 *
 * Setting IFF_DEBUG will syslog the option negotiation and state
 * transitions at level kern.debug.  Note: all logs consistently look
 * like
 *
 *   <if-name><unit>: <proto-name> <additional info...>
 *
 * with <if-name><unit> being something like "bppp0", and <proto-name>
 * being one of "lcp", "ipcp", "cisco", "chap", "pap", etc.
 */

#define IFF_PASSIVE     IFF_LINK0       /* wait passively for connection */
#define IFF_AUTO        IFF_LINK1       /* auto-dial on output */
#define IFF_CISCO       IFF_LINK2       /* auto-dial on output */

#define PPP_ALLSTATIONS 0xff            /* All-Stations broadcast address */
#define PPP_UI          0x03            /* Unnumbered Information */
#define PPP_IP          0x0021          /* Internet Protocol */
#define PPP_ISO         0x0023          /* ISO OSI Protocol */
#define PPP_XNS         0x0025          /* Xerox NS Protocol */
#define PPP_VJ_COMP     0x002d          /* VJ compressed TCP/IP */
#define PPP_VJ_UCOMP    0x002f          /* VJ uncompressed TCP/IP */
#define PPP_IPV6        0x0057          /* Internet Protocol Version 6 */
#define PPP_LCP         0xc021          /* Link Control Protocol */
#define PPP_PAP         0xc023          /* Password Authentication Protocol */
#define PPP_CHAP        0xc223          /* Challenge-Handshake Auth Protocol */
#define PPP_IPCP        0x8021          /* Internet Protocol Control Protocol */
#define PPP_IPV6CP      0x8057          /* IPv6 Control Protocol */

#define CONF_REQ        1               /* PPP configure request */
#define CONF_ACK        2               /* PPP configure acknowledge */
#define CONF_NAK        3               /* PPP configure negative ack */
#define CONF_REJ        4               /* PPP configure reject */
#define TERM_REQ        5               /* PPP terminate request */
#define TERM_ACK        6               /* PPP terminate acknowledge */
#define CODE_REJ        7               /* PPP code reject */
#define PROTO_REJ       8               /* PPP protocol reject */
#define ECHO_REQ        9               /* PPP echo request */
#define ECHO_REPLY      10              /* PPP echo reply */
#define DISC_REQ        11              /* PPP discard request */

#define LCP_OPT_MRU             1       /* maximum receive unit */
#define LCP_OPT_ASYNC_MAP       2       /* async control character map */
#define LCP_OPT_AUTH_PROTO      3       /* authentication protocol */
#define LCP_OPT_QUAL_PROTO      4       /* quality protocol */
#define LCP_OPT_MAGIC           5       /* magic number */
#define LCP_OPT_RESERVED        6       /* reserved */
#define LCP_OPT_PROTO_COMP      7       /* protocol field compression */
#define LCP_OPT_ADDR_COMP       8       /* address/control field compression */

#define IPCP_OPT_ADDRESSES      1       /* both IP addresses; deprecated */
#define IPCP_OPT_COMPRESSION    2       /* IP compression protocol (VJ) */
#define IPCP_OPT_ADDRESS        3       /* local IP address */

#define IPV6CP_OPT_IFID 1       /* interface identifier */
#define IPV6CP_OPT_COMPRESSION  2       /* IPv6 compression protocol */

#define IPCP_COMP_VJ            0x2d    /* Code for VJ compression */

#define PAP_REQ                 1       /* PAP name/password request */
#define PAP_ACK                 2       /* PAP acknowledge */
#define PAP_NAK                 3       /* PAP fail */

#define CHAP_CHALLENGE          1       /* CHAP challenge request */
#define CHAP_RESPONSE           2       /* CHAP challenge response */
#define CHAP_SUCCESS            3       /* CHAP response ok */
#define CHAP_FAILURE            4       /* CHAP response failed */

#define CHAP_MD5                5       /* hash algorithm - MD5 */

#define CISCO_MULTICAST         0x8f    /* Cisco multicast address */
#define CISCO_UNICAST           0x0f    /* Cisco unicast address */
#define CISCO_KEEPALIVE         0x8035  /* Cisco keepalive protocol */
#define CISCO_ADDR_REQ          0       /* Cisco address request */
#define CISCO_ADDR_REPLY        1       /* Cisco address reply */
#define CISCO_KEEPALIVE_REQ     2       /* Cisco keepalive request */

/* states are named and numbered according to RFC 1661 */
#define STATE_INITIAL   0
#define STATE_STARTING  1
#define STATE_CLOSED    2
#define STATE_STOPPED   3
#define STATE_CLOSING   4
#define STATE_STOPPING  5
#define STATE_REQ_SENT  6
#define STATE_ACK_RCVD  7
#define STATE_ACK_SENT  8
#define STATE_OPENED    9

struct ppp_header {
        u_char address;
        u_char control;
        u_short protocol;
} __attribute__((__packed__));
#define PPP_HEADER_LEN          sizeof (struct ppp_header)

struct lcp_header {
        u_char type;
        u_char ident;
        u_short len;
} __attribute__((__packed__));
#define LCP_HEADER_LEN          sizeof (struct lcp_header)

struct cisco_packet {
        u_long type;
        u_long par1;
        u_long par2;
        u_short rel;
        u_short time0;
        u_short time1;
} __attribute__((__packed__));
#define CISCO_PACKET_LEN        sizeof (struct cisco_packet)

/*
 * We follow the spelling and capitalization of RFC 1661 here, to make
 * it easier comparing with the standard.  Please refer to this RFC in
 * case you can't make sense out of these abbreviation; it will also
 * explain the semantics related to the various events and actions.
 */
struct cp {
        u_short proto;          /* PPP control protocol number */
        u_char protoidx;        /* index into state table in struct sppp */
        u_char flags;
#define CP_LCP          0x01    /* this is the LCP */
#define CP_AUTH         0x02    /* this is an authentication protocol */
#define CP_NCP          0x04    /* this is a NCP */
#define CP_QUAL         0x08    /* this is a quality reporting protocol */
        const char *name;       /* name of this control protocol */
        /* event handlers */
        void    (*Up)(struct sppp *sp);
        void    (*Down)(struct sppp *sp);
        void    (*Open)(struct sppp *sp);
        void    (*Close)(struct sppp *sp);
        void    (*TO)(void *sp);
        int     (*RCR)(struct sppp *sp, struct lcp_header *h, int len);
        void    (*RCN_rej)(struct sppp *sp, struct lcp_header *h, int len);
        void    (*RCN_nak)(struct sppp *sp, struct lcp_header *h, int len);
        /* actions */
        void    (*tlu)(struct sppp *sp);
        void    (*tld)(struct sppp *sp);
        void    (*tls)(struct sppp *sp);
        void    (*tlf)(struct sppp *sp);
        void    (*scr)(struct sppp *sp);
};

static struct sppp *spppq;
static struct callout keepalive_timeout;

#define SPP_FMT         "%s: "
#define SPP_ARGS(ifp)   (ifp)->if_xname

#ifdef INET
/*
 * The following disgusting hack gets around the problem that IP TOS
 * can't be set yet.  We want to put "interactive" traffic on a high
 * priority queue.  To decide if traffic is interactive, we check that
 * a) it is TCP and b) one of its ports is telnet, rlogin or ftp control.
 *
 * XXX is this really still necessary?  - joerg -
 */
static u_short interactive_ports[8] = {
        0,      513,    0,      0,
        0,      21,     0,      23,
};
#define INTERACTIVE(p) (interactive_ports[(p) & 7] == (p))
#endif

/* almost every function needs these */
#define STDDCL                                                  \
        struct ifnet *ifp = &sp->pp_if;                         \
        int debug = ifp->if_flags & IFF_DEBUG

static int sppp_output(struct ifnet *ifp, struct mbuf *m,
                       struct sockaddr *dst, struct rtentry *rt);

static void sppp_cisco_send(struct sppp *sp, int type, long par1, long par2);
static void sppp_cisco_input(struct sppp *sp, struct mbuf *m);

static void sppp_cp_input(const struct cp *cp, struct sppp *sp,
                          struct mbuf *m);
static void sppp_cp_send(struct sppp *sp, u_short proto, u_char type,
                         u_char ident, u_short len, void *data);
/* static void sppp_cp_timeout(void *arg); */
static void sppp_cp_change_state(const struct cp *cp, struct sppp *sp,
                                 int newstate);
static void sppp_auth_send(const struct cp *cp,
                           struct sppp *sp, unsigned int type, unsigned int id,
                           ...);

static void sppp_up_event(const struct cp *cp, struct sppp *sp);
static void sppp_down_event(const struct cp *cp, struct sppp *sp);
static void sppp_open_event(const struct cp *cp, struct sppp *sp);
static void sppp_close_event(const struct cp *cp, struct sppp *sp);
static void sppp_to_event(const struct cp *cp, struct sppp *sp);

static void sppp_null(struct sppp *sp);

static void sppp_lcp_init(struct sppp *sp);
static void sppp_lcp_up(struct sppp *sp);
static void sppp_lcp_down(struct sppp *sp);
static void sppp_lcp_open(struct sppp *sp);
static void sppp_lcp_close(struct sppp *sp);
static void sppp_lcp_TO(void *sp);
static int sppp_lcp_RCR(struct sppp *sp, struct lcp_header *h, int len);
static void sppp_lcp_RCN_rej(struct sppp *sp, struct lcp_header *h, int len);
static void sppp_lcp_RCN_nak(struct sppp *sp, struct lcp_header *h, int len);
static void sppp_lcp_tlu(struct sppp *sp);
static void sppp_lcp_tld(struct sppp *sp);
static void sppp_lcp_tls(struct sppp *sp);
static void sppp_lcp_tlf(struct sppp *sp);
static void sppp_lcp_scr(struct sppp *sp);
static void sppp_lcp_check_and_close(struct sppp *sp);
static int sppp_ncp_check(struct sppp *sp);

static void sppp_ipcp_init(struct sppp *sp);
static void sppp_ipcp_up(struct sppp *sp);
static void sppp_ipcp_down(struct sppp *sp);
static void sppp_ipcp_open(struct sppp *sp);
static void sppp_ipcp_close(struct sppp *sp);
static void sppp_ipcp_TO(void *sp);
static int sppp_ipcp_RCR(struct sppp *sp, struct lcp_header *h, int len);
static void sppp_ipcp_RCN_rej(struct sppp *sp, struct lcp_header *h, int len);
static void sppp_ipcp_RCN_nak(struct sppp *sp, struct lcp_header *h, int len);
static void sppp_ipcp_tlu(struct sppp *sp);
static void sppp_ipcp_tld(struct sppp *sp);
static void sppp_ipcp_tls(struct sppp *sp);
static void sppp_ipcp_tlf(struct sppp *sp);
static void sppp_ipcp_scr(struct sppp *sp);

static void sppp_ipv6cp_init(struct sppp *sp);
static void sppp_ipv6cp_up(struct sppp *sp);
static void sppp_ipv6cp_down(struct sppp *sp);
static void sppp_ipv6cp_open(struct sppp *sp);
static void sppp_ipv6cp_close(struct sppp *sp);
static void sppp_ipv6cp_TO(void *sp);
static int sppp_ipv6cp_RCR(struct sppp *sp, struct lcp_header *h, int len);
static void sppp_ipv6cp_RCN_rej(struct sppp *sp, struct lcp_header *h, int len);
static void sppp_ipv6cp_RCN_nak(struct sppp *sp, struct lcp_header *h, int len);
static void sppp_ipv6cp_tlu(struct sppp *sp);
static void sppp_ipv6cp_tld(struct sppp *sp);
static void sppp_ipv6cp_tls(struct sppp *sp);
static void sppp_ipv6cp_tlf(struct sppp *sp);
static void sppp_ipv6cp_scr(struct sppp *sp);

static void sppp_pap_input(struct sppp *sp, struct mbuf *m);
static void sppp_pap_init(struct sppp *sp);
static void sppp_pap_open(struct sppp *sp);
static void sppp_pap_close(struct sppp *sp);
static void sppp_pap_TO(void *sp);
static void sppp_pap_my_TO(void *sp);
static void sppp_pap_tlu(struct sppp *sp);
static void sppp_pap_tld(struct sppp *sp);
static void sppp_pap_scr(struct sppp *sp);

static void sppp_chap_input(struct sppp *sp, struct mbuf *m);
static void sppp_chap_init(struct sppp *sp);
static void sppp_chap_open(struct sppp *sp);
static void sppp_chap_close(struct sppp *sp);
static void sppp_chap_TO(void *sp);
static void sppp_chap_tlu(struct sppp *sp);
static void sppp_chap_tld(struct sppp *sp);
static void sppp_chap_scr(struct sppp *sp);

static const char *sppp_auth_type_name(u_short proto, u_char type);
static const char *sppp_cp_type_name(u_char type);
static const char *sppp_dotted_quad(u_long addr);
static const char *sppp_ipcp_opt_name(u_char opt);
#ifdef INET6
static const char *sppp_ipv6cp_opt_name(u_char opt);
#endif
static const char *sppp_lcp_opt_name(u_char opt);
static const char *sppp_phase_name(enum ppp_phase phase);
static const char *sppp_proto_name(u_short proto);
static const char *sppp_state_name(int state);
static int sppp_params(struct sppp *sp, u_long cmd, void *data);
static void sppp_get_ip_addrs(struct sppp *sp, u_long *src, u_long *dst,
                              u_long *srcmask);
static void sppp_keepalive(void *dummy);
static void sppp_phase_network(struct sppp *sp);
static void sppp_print_bytes(const u_char *p, u_short len);
static void sppp_print_string(const char *p, u_short len);
static void sppp_set_ip_addr(struct sppp *sp, u_long src);
#ifdef INET6
static void sppp_get_ip6_addrs(struct sppp *sp, struct in6_addr *src,
                               struct in6_addr *dst, struct in6_addr *srcmask);
#ifdef IPV6CP_MYIFID_DYN
static void sppp_set_ip6_addr(struct sppp *sp, const struct in6_addr *src);
static void sppp_gen_ip6_addr(struct sppp *sp, const struct in6_addr *src);
#endif
static void sppp_suggest_ip6_addr(struct sppp *sp, struct in6_addr *src);
#endif

/* our control protocol descriptors */
static const struct cp lcp = {
        PPP_LCP, IDX_LCP, CP_LCP, "lcp",
        sppp_lcp_up, sppp_lcp_down, sppp_lcp_open, sppp_lcp_close,
        sppp_lcp_TO, sppp_lcp_RCR, sppp_lcp_RCN_rej, sppp_lcp_RCN_nak,
        sppp_lcp_tlu, sppp_lcp_tld, sppp_lcp_tls, sppp_lcp_tlf,
        sppp_lcp_scr
};

static const struct cp ipcp = {
        PPP_IPCP, IDX_IPCP, CP_NCP, "ipcp",
        sppp_ipcp_up, sppp_ipcp_down, sppp_ipcp_open, sppp_ipcp_close,
        sppp_ipcp_TO, sppp_ipcp_RCR, sppp_ipcp_RCN_rej, sppp_ipcp_RCN_nak,
        sppp_ipcp_tlu, sppp_ipcp_tld, sppp_ipcp_tls, sppp_ipcp_tlf,
        sppp_ipcp_scr
};

static const struct cp ipv6cp = {
        PPP_IPV6CP, IDX_IPV6CP,
#ifdef INET6    /*don't run IPv6CP if there's no IPv6 support*/
        CP_NCP,
#else
        0,
#endif
        "ipv6cp",
        sppp_ipv6cp_up, sppp_ipv6cp_down, sppp_ipv6cp_open, sppp_ipv6cp_close,
        sppp_ipv6cp_TO, sppp_ipv6cp_RCR, sppp_ipv6cp_RCN_rej, sppp_ipv6cp_RCN_nak,
        sppp_ipv6cp_tlu, sppp_ipv6cp_tld, sppp_ipv6cp_tls, sppp_ipv6cp_tlf,
        sppp_ipv6cp_scr
};

static const struct cp pap = {
        PPP_PAP, IDX_PAP, CP_AUTH, "pap",
        sppp_null, sppp_null, sppp_pap_open, sppp_pap_close,
        sppp_pap_TO, 0, 0, 0,
        sppp_pap_tlu, sppp_pap_tld, sppp_null, sppp_null,
        sppp_pap_scr
};

static const struct cp chap = {
        PPP_CHAP, IDX_CHAP, CP_AUTH, "chap",
        sppp_null, sppp_null, sppp_chap_open, sppp_chap_close,
        sppp_chap_TO, 0, 0, 0,
        sppp_chap_tlu, sppp_chap_tld, sppp_null, sppp_null,
        sppp_chap_scr
};

static const struct cp *cps[IDX_COUNT] = {
        &lcp,                   /* IDX_LCP */
        &ipcp,                  /* IDX_IPCP */
        &ipv6cp,                /* IDX_IPV6CP */
        &pap,                   /* IDX_PAP */
        &chap,                  /* IDX_CHAP */
};

static int
sppp_modevent(module_t mod, int type, void *unused)
{
        switch (type) {
        case MOD_LOAD:
                callout_init(&keepalive_timeout);
                break;
        case MOD_UNLOAD:
                return EACCES;
                break;
        default:
                break;
        }
        return 0;
}
static moduledata_t spppmod = {
        "sppp",
        sppp_modevent,
        0
};
MODULE_VERSION(sppp, 1);
DECLARE_MODULE(sppp, spppmod, SI_SUB_DRIVERS, SI_ORDER_ANY);

/*
 * Exported functions, comprising our interface to the lower layer.
 */

/*
 * Process the received packet.
 */
void
sppp_input(struct ifnet *ifp, struct mbuf *m)
{
        struct ppp_header *h;
        int isr = -1;
        struct sppp *sp = (struct sppp *)ifp;
        u_char *iphdr;
        int hlen, vjlen, do_account = 0;
        int debug = ifp->if_flags & IFF_DEBUG;

        if (ifp->if_flags & IFF_UP)
                /* Count received bytes, add FCS and one flag */
                IFNET_STAT_INC(ifp, ibytes, m->m_pkthdr.len + 3);

        if (m->m_pkthdr.len <= PPP_HEADER_LEN) {
                /* Too small packet, drop it. */
                if (debug)
                        log(LOG_DEBUG,
                            SPP_FMT "input packet is too small, %d bytes\n",
                            SPP_ARGS(ifp), m->m_pkthdr.len);
drop:
                m_freem (m);
drop2:
                IFNET_STAT_INC(ifp, ierrors, 1);
                IFNET_STAT_INC(ifp, iqdrops, 1);
                return;
        }

        /* Get PPP header. */
        h = mtod (m, struct ppp_header*);
        m_adj (m, PPP_HEADER_LEN);

        switch (h->address) {
        case PPP_ALLSTATIONS:
                if (h->control != PPP_UI)
                        goto invalid;
                if (sp->pp_mode == IFF_CISCO) {
                        if (debug)
                                log(LOG_DEBUG,
                                    SPP_FMT "PPP packet in Cisco mode "
                                    "<addr=0x%x ctrl=0x%x proto=0x%x>\n",
                                    SPP_ARGS(ifp),
                                    h->address, h->control, ntohs(h->protocol));
                        goto drop;
                }
                switch (ntohs (h->protocol)) {
                default:
                        if (debug)
                                log(LOG_DEBUG,
                                    SPP_FMT "rejecting protocol "
                                    "<addr=0x%x ctrl=0x%x proto=0x%x>\n",
                                    SPP_ARGS(ifp),
                                    h->address, h->control, ntohs(h->protocol));
                        if (sp->state[IDX_LCP] == STATE_OPENED)
                                sppp_cp_send (sp, PPP_LCP, PROTO_REJ,
                                        ++sp->pp_seq[IDX_LCP], m->m_pkthdr.len + 2,
                                        &h->protocol);
                        IFNET_STAT_INC(ifp, noproto, 1);
                        goto drop;
                case PPP_LCP:
                        sppp_cp_input(&lcp, sp, m);
                        m_freem (m);
                        return;
                case PPP_PAP:
                        if (sp->pp_phase >= PHASE_AUTHENTICATE)
                                sppp_pap_input(sp, m);
                        m_freem (m);
                        return;
                case PPP_CHAP:
                        if (sp->pp_phase >= PHASE_AUTHENTICATE)
                                sppp_chap_input(sp, m);
                        m_freem (m);
                        return;
#ifdef INET
                case PPP_IPCP:
                        if (sp->pp_phase == PHASE_NETWORK)
                                sppp_cp_input(&ipcp, sp, m);
                        m_freem (m);
                        return;
                case PPP_IP:
                        if (sp->state[IDX_IPCP] == STATE_OPENED) {
                                isr = NETISR_IP;
                        }
                        do_account++;
                        break;
                case PPP_VJ_COMP:
                        if (sp->state[IDX_IPCP] == STATE_OPENED) {
                                if ((vjlen =
                                     sl_uncompress_tcp_core(mtod(m, u_char *),
                                                            m->m_len, m->m_len,
                                                            TYPE_COMPRESSED_TCP,
                                                            sp->pp_comp,
                                                            &iphdr, &hlen)) <= 0) {
                                        if (debug)
                                                log(LOG_INFO,
                            SPP_FMT "VJ uncompress failed on compressed packet\n",
                                                    SPP_ARGS(ifp));
                                        goto drop;
                                }

                                /*
                                 * Trim the VJ header off the packet, and prepend
                                 * the uncompressed IP header (which will usually
                                 * end up in two chained mbufs since there's not
                                 * enough leading space in the existing mbuf).
                                 */
                                m_adj(m, vjlen);
                                M_PREPEND(m, hlen, M_NOWAIT);
                                if (m == NULL)
                                        goto drop2;
                                bcopy(iphdr, mtod(m, u_char *), hlen);

                                isr = NETISR_IP;
                        }
                        do_account++;
                        break;
                case PPP_VJ_UCOMP:
                        if (sp->state[IDX_IPCP] == STATE_OPENED) {
                                if (sl_uncompress_tcp_core(mtod(m, u_char *),
                                                           m->m_len, m->m_len,
                                                           TYPE_UNCOMPRESSED_TCP,
                                                           sp->pp_comp,
                                                           &iphdr, &hlen) != 0) {
                                        if (debug)
                                                log(LOG_INFO,
                            SPP_FMT "VJ uncompress failed on uncompressed packet\n",
                                                    SPP_ARGS(ifp));
                                        goto drop;
                                }
                                isr = NETISR_IP;
                        }
                        do_account++;
                        break;
#endif
#ifdef INET6
                case PPP_IPV6CP:
                        if (sp->pp_phase == PHASE_NETWORK)
                            sppp_cp_input(&ipv6cp, sp, m);
                        m_freem (m);
                        return;

                case PPP_IPV6:
                        if (sp->state[IDX_IPV6CP] == STATE_OPENED) {
                                isr = NETISR_IPV6;
                        }
                        do_account++;
                        break;
#endif
                }
                break;
        case CISCO_MULTICAST:
        case CISCO_UNICAST:
                /* Don't check the control field here (RFC 1547). */
                if (sp->pp_mode != IFF_CISCO) {
                        if (debug)
                                log(LOG_DEBUG,
                                    SPP_FMT "Cisco packet in PPP mode "
                                    "<addr=0x%x ctrl=0x%x proto=0x%x>\n",
                                    SPP_ARGS(ifp),
                                    h->address, h->control, ntohs(h->protocol));
                        goto drop;
                }
                switch (ntohs (h->protocol)) {
                default:
                        IFNET_STAT_INC(ifp, noproto, 1);
                        goto invalid;
                case CISCO_KEEPALIVE:
                        sppp_cisco_input ((struct sppp*) ifp, m);
                        m_freem (m);
                        return;
#ifdef INET
                case ETHERTYPE_IP:
                        isr = NETISR_IP;
                        do_account++;
                        break;
#endif
#ifdef INET6
                case ETHERTYPE_IPV6:
                        isr = NETISR_IPV6;
                        do_account++;
                        break;
#endif
                }
                break;
        default:        /* Invalid PPP packet. */
          invalid:
                if (debug)
                        log(LOG_DEBUG,
                            SPP_FMT "invalid input packet "
                            "<addr=0x%x ctrl=0x%x proto=0x%x>\n",
                            SPP_ARGS(ifp),
                            h->address, h->control, ntohs(h->protocol));
                goto drop;
        }

        if (! (ifp->if_flags & IFF_UP) || isr < 0)
                goto drop;

        /* Check queue. */

        netisr_queue(isr, m);

        /*
         * Do only account for network packets, not for control
         * packets.  This is used by some subsystems to detect
         * idle lines.
         */
        if (do_account)
                sp->pp_last_recv = time_uptime;
}

/*
 * Enqueue transmit packet.
 */
static int
sppp_output_serialized(struct ifnet *ifp, struct ifaltq_subque *ifsq,
    struct mbuf *m, struct sockaddr *dst, struct rtentry *rt)
{
        struct sppp *sp = (struct sppp*) ifp;
        struct ppp_header *h;
        struct ifqueue *ifq = NULL;
        int rv = 0;
        int ipproto = PPP_IP;
        int debug = ifp->if_flags & IFF_DEBUG;
        struct altq_pktattr pktattr;

        crit_enter();

        if ((ifp->if_flags & IFF_UP) == 0 ||
            (ifp->if_flags & (IFF_RUNNING | IFF_AUTO)) == 0) {
#ifdef INET6
          drop:
#endif
                m_freem (m);
                crit_exit();
                return (ENETDOWN);
        }

        if ((ifp->if_flags & (IFF_RUNNING | IFF_AUTO)) == IFF_AUTO) {
#ifdef INET6
                /*
                 * XXX
                 *
                 * Hack to prevent the initialization-time generated
                 * IPv6 multicast packet to erroneously cause a
                 * dialout event in case IPv6 has been
                 * administratively disabled on that interface.
                 */
                if (dst->sa_family == AF_INET6 &&
                    !(sp->confflags & CONF_ENABLE_IPV6))
                        goto drop;
#endif
                /*
                 * Interface is not yet running, but auto-dial.  Need
                 * to start LCP for it.
                 */
                ifp->if_flags |= IFF_RUNNING;
                crit_exit();
                lcp.Open(sp);
                crit_enter();
        }

        /*
         * if the queueing discipline needs packet classification,
         * do it before prepending link headers.
         */
        ifq_classify(&ifp->if_snd, m, dst->sa_family, &pktattr);

#ifdef INET
        if (dst->sa_family == AF_INET) {
                /* XXX Check mbuf length here? */
                struct ip *ip = mtod (m, struct ip*);
                struct tcphdr *tcp = (struct tcphdr*) ((long*)ip + ip->ip_hl);

                /*
                 * When using dynamic local IP address assignment by using
                 * 0.0.0.0 as a local address, the first TCP session will
                 * not connect because the local TCP checksum is computed
                 * using 0.0.0.0 which will later become our real IP address
                 * so the TCP checksum computed at the remote end will
                 * become invalid. So we
                 * - don't let packets with src ip addr 0 thru
                 * - we flag TCP packets with src ip 0 as an error
                 */

                if(ip->ip_src.s_addr == INADDR_ANY)     /* -hm */
                {
                        m_freem(m);
                        crit_exit();
                        if(ip->ip_p == IPPROTO_TCP)
                                return(EADDRNOTAVAIL);
                        else
                                return(0);
                }

                /*
                 * Put low delay, telnet, rlogin and ftp control packets
                 * in front of the queue.
                 */
                if (IF_QFULL (&sp->pp_fastq))
                        ;
                else if (ip->ip_tos & IPTOS_LOWDELAY)
                        ifq = &sp->pp_fastq;
                else if (m->m_len < sizeof *ip + sizeof *tcp)
                        ;
                else if (ip->ip_p != IPPROTO_TCP)
                        ;
                else if (INTERACTIVE (ntohs (tcp->th_sport)))
                        ifq = &sp->pp_fastq;
                else if (INTERACTIVE (ntohs (tcp->th_dport)))
                        ifq = &sp->pp_fastq;

                /*
                 * Do IP Header compression
                 */
                if (sp->pp_mode != IFF_CISCO && (sp->ipcp.flags & IPCP_VJ) &&
                    ip->ip_p == IPPROTO_TCP)
                        switch (sl_compress_tcp(m, ip, sp->pp_comp,
                                                sp->ipcp.compress_cid)) {
                        case TYPE_COMPRESSED_TCP:
                                ipproto = PPP_VJ_COMP;
                                break;
                        case TYPE_UNCOMPRESSED_TCP:
                                ipproto = PPP_VJ_UCOMP;
                                break;
                        case TYPE_IP:
                                ipproto = PPP_IP;
                                break;
                        default:
                                m_freem(m);
                                crit_exit();
                                return (EINVAL);
                        }
        }
#endif

#ifdef INET6
        if (dst->sa_family == AF_INET6) {
                /* XXX do something tricky here? */
        }
#endif

        /*
         * Prepend general data packet PPP header. For now, IP only.
         */
        M_PREPEND (m, PPP_HEADER_LEN, M_NOWAIT);
        if (! m) {
                if (debug)
                        log(LOG_DEBUG, SPP_FMT "no memory for transmit header\n",
                                SPP_ARGS(ifp));
                IFNET_STAT_INC(ifp, oerrors, 1);
                crit_exit();
                return (ENOBUFS);
        }
        /*
         * May want to check size of packet
         * (albeit due to the implementation it's always enough)
         */
        h = mtod (m, struct ppp_header*);
        if (sp->pp_mode == IFF_CISCO) {
                h->address = CISCO_UNICAST;        /* unicast address */
                h->control = 0;
        } else {
                h->address = PPP_ALLSTATIONS;        /* broadcast address */
                h->control = PPP_UI;                 /* Unnumbered Info */
        }

        switch (dst->sa_family) {
#ifdef INET
        case AF_INET:   /* Internet Protocol */
                if (sp->pp_mode == IFF_CISCO)
                        h->protocol = htons (ETHERTYPE_IP);
                else {
                        /*
                         * Don't choke with an ENETDOWN early.  It's
                         * possible that we just started dialing out,
                         * so don't drop the packet immediately.  If
                         * we notice that we run out of buffer space
                         * below, we will however remember that we are
                         * not ready to carry IP packets, and return
                         * ENETDOWN, as opposed to ENOBUFS.
                         */
                        h->protocol = htons(ipproto);
                        if (sp->state[IDX_IPCP] != STATE_OPENED)
                                rv = ENETDOWN;
                }
                break;
#endif
#ifdef INET6
        case AF_INET6:   /* Internet Protocol */
                if (sp->pp_mode == IFF_CISCO)
                        h->protocol = htons (ETHERTYPE_IPV6);
                else {
                        /*
                         * Don't choke with an ENETDOWN early.  It's
                         * possible that we just started dialing out,
                         * so don't drop the packet immediately.  If
                         * we notice that we run out of buffer space
                         * below, we will however remember that we are
                         * not ready to carry IP packets, and return
                         * ENETDOWN, as opposed to ENOBUFS.
                         */
                        h->protocol = htons(PPP_IPV6);
                        if (sp->state[IDX_IPV6CP] != STATE_OPENED)
                                rv = ENETDOWN;
                }
                break;
#endif
        default:
                m_freem (m);
                IFNET_STAT_INC(ifp, oerrors, 1);
                crit_exit();
                return (EAFNOSUPPORT);
        }

        /*
         * Queue message on interface, and start output if interface
         * not yet active.
         */
        if (ifq != NULL) {
                if (IF_QFULL(ifq)) {
                        IF_DROP(ifq);
                        m_freem(m);
                        rv = ENOBUFS;
                } else {
                        IF_ENQUEUE(ifq, m);
                        rv = 0;
                }
        } else {
                rv = ifsq_enqueue(ifsq, m, &pktattr);
        }
        if (rv) {
                IFNET_STAT_INC(ifp, oqdrops, 1);
                crit_exit();
                return(rv);
        }
        if (!ifsq_is_oactive(ifsq))
                (*ifp->if_start) (ifp, ifsq);

        /*
         * Count output packets and bytes.
         * The packet length includes header, FCS and 1 flag,
         * according to RFC 1333.
         */
        IFNET_STAT_INC(ifp, obytes, m->m_pkthdr.len + 3);

        /*
         * Unlike in sppp_input(), we can always bump the timestamp
         * here since sppp_output() is only called on behalf of
         * network-layer traffic; control-layer traffic is handled
         * by sppp_cp_send().
         */
        sp->pp_last_sent = time_uptime;

        crit_exit();
        return (0);
}

static int
sppp_output(struct ifnet *ifp, struct mbuf *m,
            struct sockaddr *dst, struct rtentry *rt)
{
        struct ifaltq_subque *ifsq = ifq_get_subq_default(&ifp->if_snd);
        int error;

        ifsq_serialize_hw(ifsq);
        error = sppp_output_serialized(ifp, ifsq, m, dst, rt);
        ifsq_deserialize_hw(ifsq);

        return error;
}

void
sppp_attach(struct ifnet *ifp)
{
        struct sppp *sp = (struct sppp*) ifp;

        /* Initialize keepalive handler. */
        if (!spppq) {
                callout_reset(&keepalive_timeout, hz * 10,
                                sppp_keepalive, NULL);
        }
        /* Insert new entry into the keepalive list. */
        sp->pp_next = spppq;
        spppq = sp;

        sp->pp_if.if_mtu = PP_MTU;
        sp->pp_if.if_flags = IFF_POINTOPOINT | IFF_MULTICAST;
        sp->pp_if.if_type = IFT_PPP;
        sp->pp_if.if_output = sppp_output;
#if 0
        sp->pp_flags = PP_KEEPALIVE;
#endif
        ifq_set_maxlen(&sp->pp_if.if_snd, 32);
        sp->pp_fastq.ifq_maxlen = 32;
        sp->pp_cpq.ifq_maxlen = 20;
        sp->pp_loopcnt = 0;
        sp->pp_alivecnt = 0;
        bzero(&sp->pp_seq[0], sizeof(sp->pp_seq));
        bzero(&sp->pp_rseq[0], sizeof(sp->pp_rseq));
        sp->pp_phase = PHASE_DEAD;
        sp->pp_up = lcp.Up;
        sp->pp_down = lcp.Down;
        sp->pp_last_recv = sp->pp_last_sent = time_uptime;
        sp->confflags = 0;
#ifdef INET
        sp->confflags |= CONF_ENABLE_VJ;
#endif
#ifdef INET6
        sp->confflags |= CONF_ENABLE_IPV6;
#endif
        sp->pp_comp = kmalloc(sizeof(struct slcompress), M_TEMP, M_WAITOK);
        sl_compress_init(sp->pp_comp, -1);
        sppp_lcp_init(sp);
        sppp_ipcp_init(sp);
        sppp_ipv6cp_init(sp);
        sppp_pap_init(sp);
        sppp_chap_init(sp);
}

void
sppp_detach(struct ifnet *ifp)
{
        struct sppp **q, *p, *sp = (struct sppp*) ifp;
        int i;

        /* Remove the entry from the keepalive list. */
        for (q = &spppq; (p = *q); q = &p->pp_next)
                if (p == sp) {
                        *q = p->pp_next;
                        break;
                }

        /* Stop keepalive handler. */
        if (!spppq)
                callout_stop(&keepalive_timeout);

        for (i = 0; i < IDX_COUNT; i++)
                callout_stop(&sp->timeout[i]);
        callout_stop(&sp->pap_my_to);
}

/*
 * Flush the interface output queue.
 */
void
sppp_flush(struct ifnet *ifp)
{
        struct sppp *sp = (struct sppp*) ifp;

        ifq_purge_all(&sp->pp_if.if_snd);
        IF_DRAIN(&sp->pp_fastq);
        IF_DRAIN(&sp->pp_cpq);
}

/*
 * Check if the output queue is empty.
 */
int
sppp_isempty(struct ifnet *ifp)
{
        struct sppp *sp = (struct sppp*) ifp;
        int empty;

        crit_enter();
        empty = IF_QEMPTY(&sp->pp_fastq) && IF_QEMPTY(&sp->pp_cpq) &&
                ifsq_is_empty(ifq_get_subq_default(&sp->pp_if.if_snd));
        crit_exit();
        return (empty);
}

/*
 * Get next packet to send.
 */
struct mbuf *
sppp_dequeue(struct ifnet *ifp)
{
        struct sppp *sp = (struct sppp*) ifp;
        struct mbuf *m;

        crit_enter();

        /*
         * Process only the control protocol queue until we have at
         * least one NCP open.
         *
         * Do always serve all three queues in Cisco mode.
         */
        IF_DEQUEUE(&sp->pp_cpq, m);
        if (m == NULL &&
            (sppp_ncp_check(sp) || sp->pp_mode == IFF_CISCO)) {
                IF_DEQUEUE(&sp->pp_fastq, m);
                if (m == NULL) {
                        m = ifsq_dequeue(
                            ifq_get_subq_default(&sp->pp_if.if_snd));
                }
        }

        crit_exit();
        return m;
}

/*
 * Pick the next packet, do not remove it from the queue.
 */
struct mbuf *
sppp_pick(struct ifnet *ifp)
{
        struct sppp *sp = (struct sppp*)ifp;
        struct mbuf *m;

        crit_enter();

        m = sp->pp_cpq.ifq_head;
        if (m == NULL &&
            (sp->pp_phase == PHASE_NETWORK || sp->pp_mode == IFF_CISCO)) {
                if ((m = sp->pp_fastq.ifq_head) == NULL)
                        m = ifsq_poll(ifq_get_subq_default(&sp->pp_if.if_snd));
        }

        crit_exit();
        return (m);
}

/*
 * Process an ioctl request.  Called on low priority level.
 */
int
sppp_ioctl(struct ifnet *ifp, IOCTL_CMD_T cmd, void *data)
{
        struct ifreq *ifr = (struct ifreq*) data;
        struct sppp *sp = (struct sppp*) ifp;
        int rv, going_up, going_down, newmode;

        crit_enter();

        rv = 0;
        switch (cmd) {
        case SIOCAIFADDR:
        case SIOCSIFDSTADDR:
                break;

        case SIOCSIFADDR:
                /* set the interface "up" when assigning an IP address */
                ifp->if_flags |= IFF_UP;
                /* fall through... */

        case SIOCSIFFLAGS:
                going_up = ifp->if_flags & IFF_UP &&
                        (ifp->if_flags & IFF_RUNNING) == 0;
                going_down = (ifp->if_flags & IFF_UP) == 0 &&
                        ifp->if_flags & IFF_RUNNING;

                newmode = ifp->if_flags & IFF_PASSIVE;
                if (!newmode)
                        newmode = ifp->if_flags & IFF_AUTO;
                if (!newmode)
                        newmode = ifp->if_flags & IFF_CISCO;
                ifp->if_flags &= ~(IFF_PASSIVE | IFF_AUTO | IFF_CISCO);
                ifp->if_flags |= newmode;

                if (newmode != sp->pp_mode) {
                        going_down = 1;
                        if (!going_up)
                                going_up = ifp->if_flags & IFF_RUNNING;
                }

                if (going_down) {
                        if (sp->pp_mode != IFF_CISCO)
                                lcp.Close(sp);
                        else if (sp->pp_tlf)
                                (sp->pp_tlf)(sp);
                        sppp_flush(ifp);
                        ifp->if_flags &= ~IFF_RUNNING;
                        sp->pp_mode = newmode;
                }

                if (going_up) {
                        if (sp->pp_mode != IFF_CISCO)
                                lcp.Close(sp);
                        sp->pp_mode = newmode;
                        if (sp->pp_mode == 0) {
                                ifp->if_flags |= IFF_RUNNING;
                                lcp.Open(sp);
                        }
                        if (sp->pp_mode == IFF_CISCO) {
                                if (sp->pp_tls)
                                        (sp->pp_tls)(sp);
                                ifp->if_flags |= IFF_RUNNING;
                        }
                }

                break;

#ifdef SIOCSIFMTU
#ifndef ifr_mtu
#define ifr_mtu ifr_metric
#endif
        case SIOCSIFMTU:
                if (ifr->ifr_mtu < 128 || ifr->ifr_mtu > sp->lcp.their_mru) {
                        crit_exit();
                        return (EINVAL);
                }
                ifp->if_mtu = ifr->ifr_mtu;
                break;
#endif
#ifdef SLIOCSETMTU
        case SLIOCSETMTU:
                if (*(short*)data < 128 || *(short*)data > sp->lcp.their_mru) {
                        crit_exit();
                        return (EINVAL);
                }
                ifp->if_mtu = *(short*)data;
                break;
#endif
#ifdef SIOCGIFMTU
        case SIOCGIFMTU:
                ifr->ifr_mtu = ifp->if_mtu;
                break;
#endif
#ifdef SLIOCGETMTU
        case SLIOCGETMTU:
                *(short*)data = ifp->if_mtu;
                break;
#endif
        case SIOCADDMULTI:
        case SIOCDELMULTI:
                break;

        case SIOCGIFGENERIC:
        case SIOCSIFGENERIC:
                rv = sppp_params(sp, cmd, data);
                break;

        default:
                rv = ENOTTY;
        }

        crit_exit();
        return rv;
}

/*
 * Cisco framing implementation.
 */

/*
 * Handle incoming Cisco keepalive protocol packets.
 */
static void
sppp_cisco_input(struct sppp *sp, struct mbuf *m)
{
        STDDCL;
        struct cisco_packet *h;
        u_long me, mymask;

        if (m->m_pkthdr.len < CISCO_PACKET_LEN) {
                if (debug)
                        log(LOG_DEBUG,
                            SPP_FMT "cisco invalid packet length: %d bytes\n",
                            SPP_ARGS(ifp), m->m_pkthdr.len);
                return;
        }
        h = mtod (m, struct cisco_packet*);
        if (debug)
                log(LOG_DEBUG,
                    SPP_FMT "cisco input: %d bytes "
                    "<0x%lx 0x%lx 0x%lx 0x%x 0x%x-0x%x>\n",
                    SPP_ARGS(ifp), m->m_pkthdr.len,
                    (u_long)ntohl (h->type), h->par1, h->par2, (u_int)h->rel,
                    (u_int)h->time0, (u_int)h->time1);
        switch (ntohl (h->type)) {
        default:
                if (debug)
                        log(-1, SPP_FMT "cisco unknown packet type: 0x%lx\n",
                               SPP_ARGS(ifp), (u_long)ntohl (h->type));
                break;
        case CISCO_ADDR_REPLY:
                /* Reply on address request, ignore */
                break;
        case CISCO_KEEPALIVE_REQ:
                sp->pp_alivecnt = 0;
                sp->pp_rseq[IDX_LCP] = ntohl (h->par1);
                if (sp->pp_seq[IDX_LCP] == sp->pp_rseq[IDX_LCP]) {
                        /* Local and remote sequence numbers are equal.
                         * Probably, the line is in loopback mode. */
                        if (sp->pp_loopcnt >= MAXALIVECNT) {
                                kprintf (SPP_FMT "loopback\n",
                                        SPP_ARGS(ifp));
                                sp->pp_loopcnt = 0;
                                if (ifp->if_flags & IFF_UP) {
                                        if_down (ifp);
                                        IF_DRAIN(&sp->pp_cpq);
                                }
                        }
                        ++sp->pp_loopcnt;

                        /* Generate new local sequence number */
                        sp->pp_seq[IDX_LCP] = krandom();
                        break;
                }
                sp->pp_loopcnt = 0;
                if (! (ifp->if_flags & IFF_UP) &&
                    (ifp->if_flags & IFF_RUNNING)) {
                        if_up(ifp);
                        kprintf (SPP_FMT "up\n", SPP_ARGS(ifp));
                }
                break;
        case CISCO_ADDR_REQ:
                sppp_get_ip_addrs(sp, &me, 0, &mymask);
                if (me != 0L)
                        sppp_cisco_send(sp, CISCO_ADDR_REPLY, me, mymask);
                break;
        }
}

/*
 * Send Cisco keepalive packet.
 */
static void
sppp_cisco_send(struct sppp *sp, int type, long par1, long par2)
{
        STDDCL;
        struct ppp_header *h;
        struct cisco_packet *ch;
        struct mbuf *m;
        struct timeval tv;
        struct ifaltq_subque *ifsq;

        getmicrouptime(&tv);

        MGETHDR (m, M_NOWAIT, MT_DATA);
        if (! m)
                return;
        m->m_pkthdr.len = m->m_len = PPP_HEADER_LEN + CISCO_PACKET_LEN;
        m->m_pkthdr.rcvif = 0;

        h = mtod (m, struct ppp_header*);
        h->address = CISCO_MULTICAST;
        h->control = 0;
        h->protocol = htons (CISCO_KEEPALIVE);

        ch = (struct cisco_packet*) (h + 1);
        ch->type = htonl (type);
        ch->par1 = htonl (par1);
        ch->par2 = htonl (par2);
        ch->rel = -1;

        ch->time0 = htons ((u_short) (tv.tv_sec >> 16));
        ch->time1 = htons ((u_short) tv.tv_sec);

        if (debug)
                log(LOG_DEBUG,
                    SPP_FMT "cisco output: <0x%lx 0x%lx 0x%lx 0x%x 0x%x-0x%x>\n",
                        SPP_ARGS(ifp), (u_long)ntohl (ch->type), ch->par1,
                        ch->par2, (u_int)ch->rel, (u_int)ch->time0, (u_int)ch->time1);

        if (IF_QFULL (&sp->pp_cpq)) {
                IF_DROP (&sp->pp_fastq);
                m_freem (m);
        } else
                IF_ENQUEUE (&sp->pp_cpq, m);
        ifsq = ifq_get_subq_default(&ifp->if_snd);
        if (!ifsq_is_oactive(ifsq))
                (*ifp->if_start) (ifp, ifsq);
        IFNET_STAT_INC(ifp, obytes, m->m_pkthdr.len + 3);
}

/*
 * PPP protocol implementation.
 */

/*
 * Send PPP control protocol packet.
 */
static void
sppp_cp_send(struct sppp *sp, u_short proto, u_char type,
             u_char ident, u_short len, void *data)
{
        STDDCL;
        struct ppp_header *h;
        struct lcp_header *lh;
        struct mbuf *m;
        struct ifaltq_subque *ifsq;

        if (len > MHLEN - PPP_HEADER_LEN - LCP_HEADER_LEN)
                len = MHLEN - PPP_HEADER_LEN - LCP_HEADER_LEN;
        MGETHDR (m, M_NOWAIT, MT_DATA);
        if (! m)
                return;
        m->m_pkthdr.len = m->m_len = PPP_HEADER_LEN + LCP_HEADER_LEN + len;
        m->m_pkthdr.rcvif = 0;

        h = mtod (m, struct ppp_header*);
        h->address = PPP_ALLSTATIONS;        /* broadcast address */
        h->control = PPP_UI;                 /* Unnumbered Info */
        h->protocol = htons (proto);         /* Link Control Protocol */

        lh = (struct lcp_header*) (h + 1);
        lh->type = type;
        lh->ident = ident;
        lh->len = htons (LCP_HEADER_LEN + len);
        if (len)
                bcopy (data, lh+1, len);

        if (debug) {
                log(LOG_DEBUG, SPP_FMT "%s output <%s id=0x%x len=%d",
                    SPP_ARGS(ifp),
                    sppp_proto_name(proto),
                    sppp_cp_type_name (lh->type), lh->ident,
                    ntohs (lh->len));
                sppp_print_bytes ((u_char*) (lh+1), len);
                log(-1, ">\n");
        }
        if (IF_QFULL (&sp->pp_cpq)) {
                IF_DROP (&sp->pp_fastq);
                m_freem (m);
                IFNET_STAT_INC(ifp, oerrors, 1);
        } else
                IF_ENQUEUE (&sp->pp_cpq, m);
        ifsq = ifq_get_subq_default(&ifp->if_snd);
        if (!ifsq_is_oactive(ifsq))
                (*ifp->if_start) (ifp, ifsq);
        IFNET_STAT_INC(ifp, obytes, m->m_pkthdr.len + 3);
}

/*
 * Handle incoming PPP control protocol packets.
 */
static void
sppp_cp_input(const struct cp *cp, struct sppp *sp, struct mbuf *m)
{
        STDDCL;
        struct lcp_header *h;
        int printlen, len = m->m_pkthdr.len;
        int rv;
        u_char *p;

        if (len < 4) {
                if (debug)
                        log(LOG_DEBUG,
                            SPP_FMT "%s invalid packet length: %d bytes\n",
                            SPP_ARGS(ifp), cp->name, len);
                return;
        }
        h = mtod (m, struct lcp_header*);
        if (debug) {
                printlen = ntohs(h->len);
                log(LOG_DEBUG,
                    SPP_FMT "%s input(%s): <%s id=0x%x len=%d",
                    SPP_ARGS(ifp), cp->name,
                    sppp_state_name(sp->state[cp->protoidx]),
                    sppp_cp_type_name (h->type), h->ident, printlen);
                if (len < printlen)
                        printlen = len;
                if (printlen > 4)
                        sppp_print_bytes ((u_char*) (h+1), printlen - 4);
                log(-1, ">\n");
        }
        if (len > ntohs (h->len))
                len = ntohs (h->len);
        p = (u_char *)(h + 1);
        switch (h->type) {
        case CONF_REQ:
                if (len < 4) {
                        if (debug)
                                log(-1, SPP_FMT "%s invalid conf-req length %d\n",
                                       SPP_ARGS(ifp), cp->name,
                                       len);
                        IFNET_STAT_INC(ifp, ierrors, 1);
                        break;
                }
                /* handle states where RCR doesn't get a SCA/SCN */
                switch (sp->state[cp->protoidx]) {
                case STATE_CLOSING:
                case STATE_STOPPING:
                        return;
                case STATE_CLOSED:
                        sppp_cp_send(sp, cp->proto, TERM_ACK, h->ident,
                                     0, 0);
                        return;
                }
                rv = (cp->RCR)(sp, h, len);
                if (rv < 0) {
                        /* fatal error, shut down */
                        (cp->tld)(sp);
                        sppp_lcp_tlf(sp);
                        return;
                }
                switch (sp->state[cp->protoidx]) {
                case STATE_OPENED:
                        (cp->tld)(sp);
                        (cp->scr)(sp);
                        /* fall through... */
                case STATE_ACK_SENT:
                case STATE_REQ_SENT:
                        /*
                         * sppp_cp_change_state() have the side effect of
                         * restarting the timeouts. We want to avoid that
                         * if the state don't change, otherwise we won't
                         * ever timeout and resend a configuration request
                         * that got lost.
                         */
                        if (sp->state[cp->protoidx] == (rv ? STATE_ACK_SENT:
                            STATE_REQ_SENT))
                                break;
                        sppp_cp_change_state(cp, sp, rv?
                                             STATE_ACK_SENT: STATE_REQ_SENT);
                        break;
                case STATE_STOPPED:
                        sp->rst_counter[cp->protoidx] = sp->lcp.max_configure;
                        (cp->scr)(sp);
                        sppp_cp_change_state(cp, sp, rv?
                                             STATE_ACK_SENT: STATE_REQ_SENT);
                        break;
                case STATE_ACK_RCVD:
                        if (rv) {
                                sppp_cp_change_state(cp, sp, STATE_OPENED);
                                if (debug)
                                        log(LOG_DEBUG, SPP_FMT "%s tlu\n",
                                            SPP_ARGS(ifp),
                                            cp->name);
                                (cp->tlu)(sp);
                        } else
                                sppp_cp_change_state(cp, sp, STATE_ACK_RCVD);
                        break;
                default:
                        kprintf(SPP_FMT "%s illegal %s in state %s\n",
                               SPP_ARGS(ifp), cp->name,
                               sppp_cp_type_name(h->type),
                               sppp_state_name(sp->state[cp->protoidx]));
                        IFNET_STAT_INC(ifp, ierrors, 1);
                }
                break;
        case CONF_ACK:
                if (h->ident != sp->confid[cp->protoidx]) {
                        if (debug)
                                log(-1, SPP_FMT "%s id mismatch 0x%x != 0x%x\n",
                                       SPP_ARGS(ifp), cp->name,
                                       h->ident, sp->confid[cp->protoidx]);
                        IFNET_STAT_INC(ifp, ierrors, 1);
                        break;
                }
                switch (sp->state[cp->protoidx]) {
                case STATE_CLOSED:
                case STATE_STOPPED:
                        sppp_cp_send(sp, cp->proto, TERM_ACK, h->ident, 0, 0);
                        break;
                case STATE_CLOSING:
                case STATE_STOPPING:
                        break;
                case STATE_REQ_SENT:
                        sp->rst_counter[cp->protoidx] = sp->lcp.max_configure;
                        sppp_cp_change_state(cp, sp, STATE_ACK_RCVD);
                        break;
                case STATE_OPENED:
                        (cp->tld)(sp);
                        /* fall through */
                case STATE_ACK_RCVD:
                        (cp->scr)(sp);
                        sppp_cp_change_state(cp, sp, STATE_REQ_SENT);
                        break;
                case STATE_ACK_SENT:
                        sp->rst_counter[cp->protoidx] = sp->lcp.max_configure;
                        sppp_cp_change_state(cp, sp, STATE_OPENED);
                        if (debug)
                                log(LOG_DEBUG, SPP_FMT "%s tlu\n",
                                       SPP_ARGS(ifp), cp->name);
                        (cp->tlu)(sp);
                        break;
                default:
                        kprintf(SPP_FMT "%s illegal %s in state %s\n",
                               SPP_ARGS(ifp), cp->name,
                               sppp_cp_type_name(h->type),
                               sppp_state_name(sp->state[cp->protoidx]));
                        IFNET_STAT_INC(ifp, ierrors, 1);
                }
                break;
        case CONF_NAK:
        case CONF_REJ:
                if (h->ident != sp->confid[cp->protoidx]) {
                        if (debug)
                                log(-1, SPP_FMT "%s id mismatch 0x%x != 0x%x\n",
                                       SPP_ARGS(ifp), cp->name,
                                       h->ident, sp->confid[cp->protoidx]);
                        IFNET_STAT_INC(ifp, ierrors, 1);
                        break;
                }
                if (h->type == CONF_NAK)
                        (cp->RCN_nak)(sp, h, len);
                else /* CONF_REJ */
                        (cp->RCN_rej)(sp, h, len);

                switch (sp->state[cp->protoidx]) {
                case STATE_CLOSED:
                case STATE_STOPPED:
                        sppp_cp_send(sp, cp->proto, TERM_ACK, h->ident, 0, 0);
                        break;
                case STATE_REQ_SENT:
                case STATE_ACK_SENT:
                        sp->rst_counter[cp->protoidx] = sp->lcp.max_configure;
                        /*
                         * Slow things down a bit if we think we might be
                         * in loopback. Depend on the timeout to send the
                         * next configuration request.
                         */
                        if (sp->pp_loopcnt)
                                break;
                        (cp->scr)(sp);
                        break;
                case STATE_OPENED:
                        (cp->tld)(sp);
                        /* fall through */
                case STATE_ACK_RCVD:
                        sppp_cp_change_state(cp, sp, STATE_REQ_SENT);
                        (cp->scr)(sp);
                        break;
                case STATE_CLOSING:
                case STATE_STOPPING:
                        break;
                default:
                        kprintf(SPP_FMT "%s illegal %s in state %s\n",
                               SPP_ARGS(ifp), cp->name,
                               sppp_cp_type_name(h->type),
                               sppp_state_name(sp->state[cp->protoidx]));
                        IFNET_STAT_INC(ifp, ierrors, 1);
                }
                break;

        case TERM_REQ:
                switch (sp->state[cp->protoidx]) {
                case STATE_ACK_RCVD:
                case STATE_ACK_SENT:
                        sppp_cp_change_state(cp, sp, STATE_REQ_SENT);
                        /* fall through */
                case STATE_CLOSED:
                case STATE_STOPPED:
                case STATE_CLOSING:
                case STATE_STOPPING:
                case STATE_REQ_SENT:
                  sta:
                        /* Send Terminate-Ack packet. */
                        if (debug)
                                log(LOG_DEBUG, SPP_FMT "%s send terminate-ack\n",
                                    SPP_ARGS(ifp), cp->name);
                        sppp_cp_send(sp, cp->proto, TERM_ACK, h->ident, 0, 0);
                        break;
                case STATE_OPENED:
                        (cp->tld)(sp);
                        sp->rst_counter[cp->protoidx] = 0;
                        sppp_cp_change_state(cp, sp, STATE_STOPPING);
                        goto sta;
                        break;
                default:
                        kprintf(SPP_FMT "%s illegal %s in state %s\n",
                               SPP_ARGS(ifp), cp->name,
                               sppp_cp_type_name(h->type),
                               sppp_state_name(sp->state[cp->protoidx]));
                        IFNET_STAT_INC(ifp, ierrors, 1);
                }
                break;
        case TERM_ACK:
                switch (sp->state[cp->protoidx]) {
                case STATE_CLOSED:
                case STATE_STOPPED:
                case STATE_REQ_SENT:
                case STATE_ACK_SENT:
                        break;
                case STATE_CLOSING:
                        sppp_cp_change_state(cp, sp, STATE_CLOSED);
                        (cp->tlf)(sp);
                        break;
                case STATE_STOPPING:
                        sppp_cp_change_state(cp, sp, STATE_STOPPED);
                        (cp->tlf)(sp);
                        break;
                case STATE_ACK_RCVD:
                        sppp_cp_change_state(cp, sp, STATE_REQ_SENT);
                        break;
                case STATE_OPENED:
                        (cp->tld)(sp);
                        (cp->scr)(sp);
                        sppp_cp_change_state(cp, sp, STATE_ACK_RCVD);
                        break;
                default:
                        kprintf(SPP_FMT "%s illegal %s in state %s\n",
                               SPP_ARGS(ifp), cp->name,
                               sppp_cp_type_name(h->type),
                               sppp_state_name(sp->state[cp->protoidx]));
                        IFNET_STAT_INC(ifp, ierrors, 1);
                }
                break;
        case CODE_REJ:
                /* XXX catastrophic rejects (RXJ-) aren't handled yet. */
                log(LOG_INFO,
                    SPP_FMT "%s: ignoring RXJ (%s) for proto 0x%x, "
                    "danger will robinson\n",
                    SPP_ARGS(ifp), cp->name,
                    sppp_cp_type_name(h->type), ntohs(*((u_short *)p)));
                switch (sp->state[cp->protoidx]) {
                case STATE_CLOSED:
                case STATE_STOPPED:
                case STATE_REQ_SENT:
                case STATE_ACK_SENT:
                case STATE_CLOSING:
                case STATE_STOPPING:
                case STATE_OPENED:
                        break;
                case STATE_ACK_RCVD:
                        sppp_cp_change_state(cp, sp, STATE_REQ_SENT);
                        break;
                default:
                        kprintf(SPP_FMT "%s illegal %s in state %s\n",
                               SPP_ARGS(ifp), cp->name,
                               sppp_cp_type_name(h->type),
                               sppp_state_name(sp->state[cp->protoidx]));
                        IFNET_STAT_INC(ifp, ierrors, 1);
                }
                break;
        case PROTO_REJ:
            {
                int catastrophic;
                const struct cp *upper;
                int i;
                u_int16_t proto;

                catastrophic = 0;
                upper = NULL;
                proto = ntohs(*((u_int16_t *)p));
                for (i = 0; i < IDX_COUNT; i++) {
                        if (cps[i]->proto == proto) {
                                upper = cps[i];
                                break;
                        }
                }
                if (upper == NULL)
                        catastrophic++;

                if (catastrophic || debug)
                        log(catastrophic? LOG_INFO: LOG_DEBUG,
                            SPP_FMT "%s: RXJ%c (%s) for proto 0x%x (%s/%s)\n",
                            SPP_ARGS(ifp), cp->name, catastrophic ? '-' : '+',
                            sppp_cp_type_name(h->type), proto,
                            upper ? upper->name : "unknown",
                            upper ? sppp_state_name(sp->state[upper->protoidx]) : "?");

                /*
                 * if we got RXJ+ against conf-req, the peer does not implement
                 * this particular protocol type.  terminate the protocol.
                 */
                if (upper && !catastrophic) {
                        if (sp->state[upper->protoidx] == STATE_REQ_SENT) {
                                upper->Close(sp);
                                break;
                        }
                }

                /* XXX catastrophic rejects (RXJ-) aren't handled yet. */
                switch (sp->state[cp->protoidx]) {
                case STATE_CLOSED:
                case STATE_STOPPED:
                case STATE_REQ_SENT:
                case STATE_ACK_SENT:
                case STATE_CLOSING:
                case STATE_STOPPING:
                case STATE_OPENED:
                        break;
                case STATE_ACK_RCVD:
                        sppp_cp_change_state(cp, sp, STATE_REQ_SENT);
                        break;
                default:
                        kprintf(SPP_FMT "%s illegal %s in state %s\n",
                               SPP_ARGS(ifp), cp->name,
                               sppp_cp_type_name(h->type),
                               sppp_state_name(sp->state[cp->protoidx]));
                        IFNET_STAT_INC(ifp, ierrors, 1);
                }
                break;
            }
        case DISC_REQ:
                if (cp->proto != PPP_LCP)
                        goto illegal;
                /* Discard the packet. */
                break;
        case ECHO_REQ:
                if (cp->proto != PPP_LCP)
                        goto illegal;
                if (sp->state[cp->protoidx] != STATE_OPENED) {
                        if (debug)
                                log(-1, SPP_FMT "lcp echo req but lcp closed\n",
                                       SPP_ARGS(ifp));
                        IFNET_STAT_INC(ifp, ierrors, 1);
                        break;
                }
                if (len < 8) {
                        if (debug)
                                log(-1, SPP_FMT "invalid lcp echo request "
                                       "packet length: %d bytes\n",
                                       SPP_ARGS(ifp), len);
                        break;
                }
                if ((sp->lcp.opts & (1 << LCP_OPT_MAGIC)) &&
                    ntohl (*(long*)(h+1)) == sp->lcp.magic) {
                        /* Line loopback mode detected. */
                        kprintf(SPP_FMT "loopback\n", SPP_ARGS(ifp));
                        sp->pp_loopcnt = MAXALIVECNT * 5;
                        if_down (ifp);
                        IF_DRAIN(&sp->pp_cpq);

                        /* Shut down the PPP link. */
                        /* XXX */
                        lcp.Down(sp);
                        lcp.Up(sp);
                        break;
                }
                *(long*)(h+1) = htonl (sp->lcp.magic);
                if (debug)
                        log(-1, SPP_FMT "got lcp echo req, sending echo rep\n",
                               SPP_ARGS(ifp));
                sppp_cp_send (sp, PPP_LCP, ECHO_REPLY, h->ident, len-4, h+1);
                break;
        case ECHO_REPLY:
                if (cp->proto != PPP_LCP)
                        goto illegal;
                if (h->ident != sp->lcp.echoid) {
                        IFNET_STAT_INC(ifp, ierrors, 1);
                        break;
                }
                if (len < 8) {
                        if (debug)
                                log(-1, SPP_FMT "lcp invalid echo reply "
                                       "packet length: %d bytes\n",
                                       SPP_ARGS(ifp), len);
                        break;
                }
                if (debug)
                        log(-1, SPP_FMT "lcp got echo rep\n",
                               SPP_ARGS(ifp));
                if (!(sp->lcp.opts & (1 << LCP_OPT_MAGIC)) ||
                    ntohl (*(long*)(h+1)) != sp->lcp.magic)
                        sp->pp_alivecnt = 0;
                break;
        default:
                /* Unknown packet type -- send Code-Reject packet. */
          illegal:
                if (debug)
                        log(-1, SPP_FMT "%s send code-rej for 0x%x\n",
                               SPP_ARGS(ifp), cp->name, h->type);
                sppp_cp_send(sp, cp->proto, CODE_REJ,
                             ++sp->pp_seq[cp->protoidx], m->m_pkthdr.len, h);
                IFNET_STAT_INC(ifp, ierrors, 1);
        }
}


/*
 * The generic part of all Up/Down/Open/Close/TO event handlers.
 * Basically, the state transition handling in the automaton.
 */
static void
sppp_up_event(const struct cp *cp, struct sppp *sp)
{
        STDDCL;

        if (debug)
                log(LOG_DEBUG, SPP_FMT "%s up(%s)\n",
                    SPP_ARGS(ifp), cp->name,
                    sppp_state_name(sp->state[cp->protoidx]));

        switch (sp->state[cp->protoidx]) {
        case STATE_INITIAL:
                sppp_cp_change_state(cp, sp, STATE_CLOSED);
                break;
        case STATE_STARTING:
                sp->rst_counter[cp->protoidx] = sp->lcp.max_configure;
                (cp->scr)(sp);
                sppp_cp_change_state(cp, sp, STATE_REQ_SENT);
                break;
        default:
                kprintf(SPP_FMT "%s illegal up in state %s\n",
                       SPP_ARGS(ifp), cp->name,
                       sppp_state_name(sp->state[cp->protoidx]));
        }
}

static void
sppp_down_event(const struct cp *cp, struct sppp *sp)
{
        STDDCL;

        if (debug)
                log(LOG_DEBUG, SPP_FMT "%s down(%s)\n",
                    SPP_ARGS(ifp), cp->name,
                    sppp_state_name(sp->state[cp->protoidx]));

        switch (sp->state[cp->protoidx]) {
        case STATE_CLOSED:
        case STATE_CLOSING:
                sppp_cp_change_state(cp, sp, STATE_INITIAL);
                break;
        case STATE_STOPPED:
                sppp_cp_change_state(cp, sp, STATE_STARTING);
                (cp->tls)(sp);
                break;
        case STATE_STOPPING:
        case STATE_REQ_SENT:
        case STATE_ACK_RCVD:
        case STATE_ACK_SENT:
                sppp_cp_change_state(cp, sp, STATE_STARTING);
                break;
        case STATE_OPENED:
                (cp->tld)(sp);
                sppp_cp_change_state(cp, sp, STATE_STARTING);
                break;
        default:
                kprintf(SPP_FMT "%s illegal down in state %s\n",
                       SPP_ARGS(ifp), cp->name,
                       sppp_state_name(sp->state[cp->protoidx]));
        }
}


static void
sppp_open_event(const struct cp *cp, struct sppp *sp)
{
        STDDCL;

        if (debug)
                log(LOG_DEBUG, SPP_FMT "%s open(%s)\n",
                    SPP_ARGS(ifp), cp->name,
                    sppp_state_name(sp->state[cp->protoidx]));

        switch (sp->state[cp->protoidx]) {
        case STATE_INITIAL:
                sppp_cp_change_state(cp, sp, STATE_STARTING);
                (cp->tls)(sp);
                break;
        case STATE_STARTING:
                break;
        case STATE_CLOSED:
                sp->rst_counter[cp->protoidx] = sp->lcp.max_configure;
                (cp->scr)(sp);
                sppp_cp_change_state(cp, sp, STATE_REQ_SENT);
                break;
        case STATE_STOPPED:
                /*
                 * Try escaping stopped state.  This seems to bite
                 * people occasionally, in particular for IPCP,
                 * presumably following previous IPCP negotiation
                 * aborts.  Somehow, we must have missed a Down event
                 * which would have caused a transition into starting
                 * state, so as a bandaid we force the Down event now.
                 * This effectively implements (something like the)
                 * `restart' option mentioned in the state transition
                 * table of RFC 1661.
                 */
                sppp_cp_change_state(cp, sp, STATE_STARTING);
                (cp->tls)(sp);
                break;
        case STATE_STOPPING:
        case STATE_REQ_SENT:
        case STATE_ACK_RCVD:
        case STATE_ACK_SENT:
        case STATE_OPENED:
                break;
        case STATE_CLOSING:
                sppp_cp_change_state(cp, sp, STATE_STOPPING);
                break;
        }
}


static void
sppp_close_event(const struct cp *cp, struct sppp *sp)
{
        STDDCL;

        if (debug)
                log(LOG_DEBUG, SPP_FMT "%s close(%s)\n",
                    SPP_ARGS(ifp), cp->name,
                    sppp_state_name(sp->state[cp->protoidx]));

        switch (sp->state[cp->protoidx]) {
        case STATE_INITIAL:
        case STATE_CLOSED:
        case STATE_CLOSING:
                break;
        case STATE_STARTING:
                sppp_cp_change_state(cp, sp, STATE_INITIAL);
                (cp->tlf)(sp);
                break;
        case STATE_STOPPED:
                sppp_cp_change_state(cp, sp, STATE_CLOSED);
                break;
        case STATE_STOPPING:
                sppp_cp_change_state(cp, sp, STATE_CLOSING);
                break;
        case STATE_OPENED:
                (cp->tld)(sp);
                /* fall through */
        case STATE_REQ_SENT:
        case STATE_ACK_RCVD:
        case STATE_ACK_SENT:
                sp->rst_counter[cp->protoidx] = sp->lcp.max_terminate;
                sppp_cp_send(sp, cp->proto, TERM_REQ,
                             ++sp->pp_seq[cp->protoidx], 0, 0);
                sppp_cp_change_state(cp, sp, STATE_CLOSING);
                break;
        }
}

static void
sppp_to_event(const struct cp *cp, struct sppp *sp)
{
        STDDCL;

        crit_enter();

        if (debug)
                log(LOG_DEBUG, SPP_FMT "%s TO(%s) rst_counter = %d\n",
                    SPP_ARGS(ifp), cp->name,
                    sppp_state_name(sp->state[cp->protoidx]),
                    sp->rst_counter[cp->protoidx]);

        if (--sp->rst_counter[cp->protoidx] < 0)
                /* TO- event */
                switch (sp->state[cp->protoidx]) {
                case STATE_CLOSING:
                        sppp_cp_change_state(cp, sp, STATE_CLOSED);
                        (cp->tlf)(sp);
                        break;
                case STATE_STOPPING:
                        sppp_cp_change_state(cp, sp, STATE_STOPPED);
                        (cp->tlf)(sp);
                        break;
                case STATE_REQ_SENT:
                case STATE_ACK_RCVD:
                case STATE_ACK_SENT:
                        sppp_cp_change_state(cp, sp, STATE_STOPPED);
                        (cp->tlf)(sp);
                        break;
                }
        else
                /* TO+ event */
                switch (sp->state[cp->protoidx]) {
                case STATE_CLOSING:
                case STATE_STOPPING:
                        sppp_cp_send(sp, cp->proto, TERM_REQ,
                                     ++sp->pp_seq[cp->protoidx], 0, 0);
                        callout_reset(&sp->timeout[cp->protoidx],
                                        sp->lcp.timeout, cp->TO, sp);
                        break;
                case STATE_REQ_SENT:
                case STATE_ACK_RCVD:
                        (cp->scr)(sp);
                        /* sppp_cp_change_state() will restart the timer */
                        sppp_cp_change_state(cp, sp, STATE_REQ_SENT);
                        break;
                case STATE_ACK_SENT:
                        (cp->scr)(sp);
                        callout_reset(&sp->timeout[cp->protoidx],
                                        sp->lcp.timeout, cp->TO, sp);
                        break;
                }

        crit_exit();
}

/*
 * Change the state of a control protocol in the state automaton.
 * Takes care of starting/stopping the restart timer.
 */
static void
sppp_cp_change_state(const struct cp *cp, struct sppp *sp, int newstate)
{
        sp->state[cp->protoidx] = newstate;
        callout_stop(&sp->timeout[cp->protoidx]);

        switch (newstate) {
        case STATE_INITIAL:
        case STATE_STARTING:
        case STATE_CLOSED:
        case STATE_STOPPED:
        case STATE_OPENED:
                break;
        case STATE_CLOSING:
        case STATE_STOPPING:
        case STATE_REQ_SENT:
        case STATE_ACK_RCVD:
        case STATE_ACK_SENT:
                callout_reset(&sp->timeout[cp->protoidx], 
                                sp->lcp.timeout, cp->TO, sp);
                break;
        }
}

/*
 *--------------------------------------------------------------------------*
 *                                                                          *
 *                         The LCP implementation.                          *
 *                                                                          *
 *--------------------------------------------------------------------------*
 */
static void
sppp_lcp_init(struct sppp *sp)
{
        sp->lcp.opts = (1 << LCP_OPT_MAGIC);
        sp->lcp.magic = 0;
        sp->state[IDX_LCP] = STATE_INITIAL;
        sp->fail_counter[IDX_LCP] = 0;
        sp->pp_seq[IDX_LCP] = 0;
        sp->pp_rseq[IDX_LCP] = 0;
        sp->lcp.protos = 0;
        sp->lcp.mru = sp->lcp.their_mru = PP_MTU;

        /* Note that these values are  relevant for all control protocols */
        sp->lcp.timeout = 3 * hz;
        sp->lcp.max_terminate = 2;
        sp->lcp.max_configure = 10;
        sp->lcp.max_failure = 10;
        callout_init(&sp->timeout[IDX_LCP]);
}

static void
sppp_lcp_up(struct sppp *sp)
{
        STDDCL;

        sp->pp_alivecnt = 0;
        sp->lcp.opts = (1 << LCP_OPT_MAGIC);
        sp->lcp.magic = 0;
        sp->lcp.protos = 0;
        sp->lcp.mru = sp->lcp.their_mru = PP_MTU;
        /*
         * If this interface is passive or dial-on-demand, and we are
         * still in Initial state, it means we've got an incoming
         * call.  Activate the interface.
         */
        if ((ifp->if_flags & (IFF_AUTO | IFF_PASSIVE)) != 0) {
                if (debug)
                        log(LOG_DEBUG,
                            SPP_FMT "Up event", SPP_ARGS(ifp));
                ifp->if_flags |= IFF_RUNNING;
                if (sp->state[IDX_LCP] == STATE_INITIAL) {
                        if (debug)
                                log(-1, "(incoming call)\n");
                        sp->pp_flags |= PP_CALLIN;
                        lcp.Open(sp);
                } else if (debug)
                        log(-1, "\n");
        } else if ((ifp->if_flags & (IFF_AUTO | IFF_PASSIVE)) == 0 &&
                   (sp->state[IDX_LCP] == STATE_INITIAL)) {
                ifp->if_flags |= IFF_RUNNING;
                lcp.Open(sp);
        }

        sppp_up_event(&lcp, sp);
}

static void
sppp_lcp_down(struct sppp *sp)
{
        STDDCL;

        sppp_down_event(&lcp, sp);

        /*
         * If this is neither a dial-on-demand nor a passive
         * interface, simulate an ``ifconfig down'' action, so the
         * administrator can force a redial by another ``ifconfig
         * up''.  XXX For leased line operation, should we immediately
         * try to reopen the connection here?
         */
        if ((ifp->if_flags & (IFF_AUTO | IFF_PASSIVE)) == 0) {
                log(LOG_INFO,
                    SPP_FMT "Down event, taking interface down.\n",
                    SPP_ARGS(ifp));
                if_down(ifp);
        } else {
                if (debug)
                        log(LOG_DEBUG,
                            SPP_FMT "Down event (carrier loss)\n",
                            SPP_ARGS(ifp));
                sp->pp_flags &= ~PP_CALLIN;
                if (sp->state[IDX_LCP] != STATE_INITIAL)
                        lcp.Close(sp);
                ifp->if_flags &= ~IFF_RUNNING;
        }
}

static void
sppp_lcp_open(struct sppp *sp)
{
        /*
         * If we are authenticator, negotiate LCP_AUTH
         */
        if (sp->hisauth.proto != 0)
                sp->lcp.opts |= (1 << LCP_OPT_AUTH_PROTO);
        else
                sp->lcp.opts &= ~(1 << LCP_OPT_AUTH_PROTO);
        sp->pp_flags &= ~PP_NEEDAUTH;
        sppp_open_event(&lcp, sp);
}

static void
sppp_lcp_close(struct sppp *sp)
{
        sppp_close_event(&lcp, sp);
}

static void
sppp_lcp_TO(void *cookie)
{
        sppp_to_event(&lcp, (struct sppp *)cookie);
}

/*
 * Analyze a configure request.  Return true if it was agreeable, and
 * caused action sca, false if it has been rejected or nak'ed, and
 * caused action scn.  (The return value is used to make the state
 * transition decision in the state automaton.)
 */
static int
sppp_lcp_RCR(struct sppp *sp, struct lcp_header *h, int len)
{
        STDDCL;
        u_char *buf, *r, *p;
        int origlen, rlen;
        u_long nmagic;
        u_short authproto;

        len -= 4;
        origlen = len;
        buf = r = kmalloc (len, M_TEMP, M_INTWAIT);

        if (debug)
                log(LOG_DEBUG, SPP_FMT "lcp parse opts: ",
                    SPP_ARGS(ifp));

        /* pass 1: check for things that need to be rejected */
        p = (void*) (h+1);
        for (rlen=0; len>1 && p[1]; len-=p[1], p+=p[1]) {
                /* Sanity check option length */
                if (p[1] > len) {
                        /* Malicious option - drop immediately.
                         * XXX Maybe we should just RXJ it?
                         */
                         log(-1, "%s: received malicious LCP option 0x%02x, "
                             "length 0x%02x, (len: 0x%02x) dropping.\n", ifp->if_xname,
                             p[0], p[1], len);
                        goto drop;
                }
                if (debug)
                        log(-1, " %s ", sppp_lcp_opt_name(*p));
                switch (*p) {
                case LCP_OPT_MAGIC:
                        /* Magic number. */
                        if (len >= 6 && p[1] == 6)
                                continue;
                        if (debug)
                                log(-1, "[invalid] ");
                        break;
                case LCP_OPT_ASYNC_MAP:
                        /* Async control character map. */
                        if (len >= 6 && p[1] == 6)
                                continue;
                        if (debug)
                                log(-1, "[invalid] ");
                        break;
                case LCP_OPT_MRU:
                        /* Maximum receive unit. */
                        if (len >= 4 && p[1] == 4)
                                continue;
                        if (debug)
                                log(-1, "[invalid] ");
                        break;
                case LCP_OPT_AUTH_PROTO:
                        if (len < 4) {
                                if (debug)
                                        log(-1, "[invalid] ");
                                break;
                        }
                        authproto = (p[2] << 8) + p[3];
                        if (authproto == PPP_CHAP && p[1] != 5) {
                                if (debug)
                                        log(-1, "[invalid chap len] ");
                                break;
                        }
                        if (sp->myauth.proto == 0) {
                                /* we are not configured to do auth */
                                if (debug)
                                        log(-1, "[not configured] ");
                                break;
                        }
                        /*
                         * Remote want us to authenticate, remember this,
                         * so we stay in PHASE_AUTHENTICATE after LCP got
                         * up.
                         */
                        sp->pp_flags |= PP_NEEDAUTH;
                        continue;
                default:
                        /* Others not supported. */
                        if (debug)
                                log(-1, "[rej] ");
                        break;
                }
                /* Add the option to rejected list. */
                bcopy (p, r, p[1]);
                r += p[1];
                rlen += p[1];
        }
        if (rlen) {
                if (debug)
                        log(-1, " send conf-rej\n");
                sppp_cp_send (sp, PPP_LCP, CONF_REJ, h->ident, rlen, buf);
                return 0;
        } else if (debug)
                log(-1, "\n");

        /*
         * pass 2: check for option values that are unacceptable and
         * thus require to be nak'ed.
         */
        if (debug)
                log(LOG_DEBUG, SPP_FMT "lcp parse opt values: ",
                    SPP_ARGS(ifp));

        p = (void*) (h+1);
        len = origlen;
        for (rlen=0; len>1 && p[1]; len-=p[1], p+=p[1]) {
                if (debug)
                        log(-1, " %s ", sppp_lcp_opt_name(*p));
                switch (*p) {
                case LCP_OPT_MAGIC:
                        /* Magic number -- extract. */
                        nmagic = (u_long)p[2] << 24 |
                                (u_long)p[3] << 16 | p[4] << 8 | p[5];
                        if (nmagic != sp->lcp.magic) {
                                sp->pp_loopcnt = 0;
                                if (debug)
                                        log(-1, "0x%lx ", nmagic);
                                continue;
                        }
                        if (debug && sp->pp_loopcnt < MAXALIVECNT*5)
                                log(-1, "[glitch] ");
                        ++sp->pp_loopcnt;
                        /*
                         * We negate our magic here, and NAK it.  If
                         * we see it later in an NAK packet, we
                         * suggest a new one.
                         */
                        nmagic = ~sp->lcp.magic;
                        /* Gonna NAK it. */
                        p[2] = nmagic >> 24;
                        p[3] = nmagic >> 16;
                        p[4] = nmagic >> 8;
                        p[5] = nmagic;
                        break;

                case LCP_OPT_ASYNC_MAP:
                        /*
                         * Async control character map -- just ignore it.
                         *
                         * Quote from RFC 1662, chapter 6:
                         * To enable this functionality, synchronous PPP
                         * implementations MUST always respond to the
                         * Async-Control-Character-Map Configuration
                         * Option with the LCP Configure-Ack.  However,
                         * acceptance of the Configuration Option does
                         * not imply that the synchronous implementation
                         * will do any ACCM mapping.  Instead, all such
                         * octet mapping will be performed by the
                         * asynchronous-to-synchronous converter.
                         */
                        continue;

                case LCP_OPT_MRU:
                        /*
                         * Maximum receive unit.  Always agreeable,
                         * but ignored by now.
                         */
                        sp->lcp.their_mru = p[2] * 256 + p[3];
                        if (debug)
                                log(-1, "%lu ", sp->lcp.their_mru);
                        continue;

                case LCP_OPT_AUTH_PROTO:
                        authproto = (p[2] << 8) + p[3];
                        if (sp->myauth.proto != authproto) {
                                /* not agreed, nak */
                                if (debug)
                                        log(-1, "[mine %s != his %s] ",
                                               sppp_proto_name(sp->hisauth.proto),
                                               sppp_proto_name(authproto));
                                p[2] = sp->myauth.proto >> 8;
                                p[3] = sp->myauth.proto;
                                break;
                        }
                        if (authproto == PPP_CHAP && p[4] != CHAP_MD5) {
                                if (debug)
                                        log(-1, "[chap not MD5] ");
                                p[4] = CHAP_MD5;
                                break;
                        }
                        continue;
                }
                /* Add the option to nak'ed list. */
                bcopy (p, r, p[1]);
                r += p[1];
                rlen += p[1];
        }
        if (rlen) {
                /*
                 * Local and remote magics equal -- loopback?
                 */
                if (sp->pp_loopcnt >= MAXALIVECNT*5) {
                        if (sp->pp_loopcnt == MAXALIVECNT*5)
                                kprintf (SPP_FMT "loopback\n",
                                        SPP_ARGS(ifp));
                        if (ifp->if_flags & IFF_UP) {
                                if_down(ifp);
                                IF_DRAIN(&sp->pp_cpq);
                                /* XXX ? */
                                lcp.Down(sp);
                                lcp.Up(sp);
                        }
                } else if (++sp->fail_counter[IDX_LCP] >= sp->lcp.max_failure) {
                        if (debug)
                                log(-1, " max_failure (%d) exceeded, "
                                       "send conf-rej\n",
                                       sp->lcp.max_failure);
                        sppp_cp_send(sp, PPP_LCP, CONF_REJ, h->ident, rlen, buf);
                } else {
                        if (debug)
                                log(-1, " send conf-nak\n");
                        sppp_cp_send (sp, PPP_LCP, CONF_NAK, h->ident, rlen, buf);
                }
        } else {
                if (debug)
                        log(-1, " send conf-ack\n");
                sp->fail_counter[IDX_LCP] = 0;
                sp->pp_loopcnt = 0;
                sppp_cp_send (sp, PPP_LCP, CONF_ACK,
                              h->ident, origlen, h+1);
        }

        kfree (buf, M_TEMP);
        return (rlen == 0);

drop:
        kfree(buf, M_TEMP);
        return (-1);
}

/*
 * Analyze the LCP Configure-Reject option list, and adjust our
 * negotiation.
 */
static void
sppp_lcp_RCN_rej(struct sppp *sp, struct lcp_header *h, int len)
{
        STDDCL;
        u_char *buf, *p;

        len -= 4;
        buf = kmalloc (len, M_TEMP, M_INTWAIT);

        if (debug)
                log(LOG_DEBUG, SPP_FMT "lcp rej opts: ",
                    SPP_ARGS(ifp));

        p = (void*) (h+1);
        for (; len > 1 && p[1]; len -= p[1], p += p[1]) {
                /* Sanity check option length */
                if (p[1] > len) {
                        /*
                         * Malicious option - drop immediately.
                         * XXX Maybe we should just RXJ it?
                         */
                        log(-1, "%s: received malicious LCP option, "
                            "dropping.\n", ifp->if_xname);
                        goto drop;
                }
                if (debug)
                        log(-1, " %s ", sppp_lcp_opt_name(*p));
                switch (*p) {
                case LCP_OPT_MAGIC:
                        /* Magic number -- can't use it, use 0 */
                        sp->lcp.opts &= ~(1 << LCP_OPT_MAGIC);
                        sp->lcp.magic = 0;
                        break;
                case LCP_OPT_MRU:
                        /*
                         * Should not be rejected anyway, since we only
                         * negotiate a MRU if explicitly requested by
                         * peer.
                         */
                        sp->lcp.opts &= ~(1 << LCP_OPT_MRU);
                        break;
                case LCP_OPT_AUTH_PROTO:
                        /*
                         * Peer doesn't want to authenticate himself,
                         * deny unless this is a dialout call, and
                         * AUTHFLAG_NOCALLOUT is set.
                         */
                        if ((sp->pp_flags & PP_CALLIN) == 0 &&
                            (sp->hisauth.flags & AUTHFLAG_NOCALLOUT) != 0) {
                                if (debug)
                                        log(-1, "[don't insist on auth "
                                               "for callout]");
                                sp->lcp.opts &= ~(1 << LCP_OPT_AUTH_PROTO);
                                break;
                        }
                        if (debug)
                                log(-1, "[access denied]\n");
                        lcp.Close(sp);
                        break;
                }
        }
        if (debug)
                log(-1, "\n");
drop:
        kfree (buf, M_TEMP);
        return;
}

/*
 * Analyze the LCP Configure-NAK option list, and adjust our
 * negotiation.
 */
static void
sppp_lcp_RCN_nak(struct sppp *sp, struct lcp_header *h, int len)
{
        STDDCL;
        u_char *buf, *p;
        u_long magic;

        len -= 4;
        buf = kmalloc (len, M_TEMP, M_INTWAIT);

        if (debug)
                log(LOG_DEBUG, SPP_FMT "lcp nak opts: ",
                    SPP_ARGS(ifp));

        p = (void*) (h+1);
        for (; len > 1 && p[1]; len -= p[1], p += p[1]) {
                /* Sanity check option length */
                if (p[1] > len) {
                        /*
                         * Malicious option - drop immediately.
                         * XXX Maybe we should just RXJ it?
                         */
                        log(-1, "%s: received malicious LCP option, "
                            "dropping.\n", ifp->if_xname);
                        goto drop;
                }
                if (debug)
                        log(-1, " %s ", sppp_lcp_opt_name(*p));
                switch (*p) {
                case LCP_OPT_MAGIC:
                        /* Magic number -- renegotiate */
                        if ((sp->lcp.opts & (1 << LCP_OPT_MAGIC)) &&
                            len >= 6 && p[1] == 6) {
                                magic = (u_long)p[2] << 24 |
                                        (u_long)p[3] << 16 | p[4] << 8 | p[5];
                                /*
                                 * If the remote magic is our negated one,
                                 * this looks like a loopback problem.
                                 * Suggest a new magic to make sure.
                                 */
                                if (magic == ~sp->lcp.magic) {
                                        if (debug)
                                                log(-1, "magic glitch ");
                                        sp->lcp.magic = krandom();
                                } else {
                                        sp->lcp.magic = magic;
                                        if (debug)
                                                log(-1, "%lu ", magic);
                                }
                        }
                        break;
                case LCP_OPT_MRU:
                        /*
                         * Peer wants to advise us to negotiate an MRU.
                         * Agree on it if it's reasonable, or use
                         * default otherwise.
                         */
                        if (len >= 4 && p[1] == 4) {
                                u_int mru = p[2] * 256 + p[3];
                                if (debug)
                                        log(-1, "%d ", mru);
                                if (mru < PP_MTU || mru > PP_MAX_MRU)
                                        mru = PP_MTU;
                                sp->lcp.mru = mru;
                                sp->lcp.opts |= (1 << LCP_OPT_MRU);
                        }
                        break;
                case LCP_OPT_AUTH_PROTO:
                        /*
                         * Peer doesn't like our authentication method,
                         * deny.
                         */
                        if (debug)
                                log(-1, "[access denied]\n");
                        lcp.Close(sp);
                        break;
                }
        }
        if (debug)
                log(-1, "\n");
drop:
        kfree (buf, M_TEMP);
        return;
}

static void
sppp_lcp_tlu(struct sppp *sp)
{
        STDDCL;
        int i;
        u_long mask;

        /* XXX ? */
        if (! (ifp->if_flags & IFF_UP) &&
            (ifp->if_flags & IFF_RUNNING)) {
                /* Coming out of loopback mode. */
                if_up(ifp);
                kprintf (SPP_FMT "up\n", SPP_ARGS(ifp));
        }

        for (i = 0; i < IDX_COUNT; i++)
                if ((cps[i])->flags & CP_QUAL)
                        (cps[i])->Open(sp);

        if ((sp->lcp.opts & (1 << LCP_OPT_AUTH_PROTO)) != 0 ||
            (sp->pp_flags & PP_NEEDAUTH) != 0)
                sp->pp_phase = PHASE_AUTHENTICATE;
        else
                sp->pp_phase = PHASE_NETWORK;

        if (debug)
                log(LOG_DEBUG, SPP_FMT "phase %s\n", SPP_ARGS(ifp),
                    sppp_phase_name(sp->pp_phase));

        /*
         * Open all authentication protocols.  This is even required
         * if we already proceeded to network phase, since it might be
         * that remote wants us to authenticate, so we might have to
         * send a PAP request.  Undesired authentication protocols
         * don't do anything when they get an Open event.
         */
        for (i = 0; i < IDX_COUNT; i++)
                if ((cps[i])->flags & CP_AUTH)
                        (cps[i])->Open(sp);

        if (sp->pp_phase == PHASE_NETWORK) {
                /* Notify all NCPs. */
                for (i = 0; i < IDX_COUNT; i++)
                        if (((cps[i])->flags & CP_NCP) &&
                            /*
                             * XXX
                             * Hack to administratively disable IPv6 if
                             * not desired.  Perhaps we should have another
                             * flag for this, but right now, we can make
                             * all struct cp's read/only.
                             */
                            (cps[i] != &ipv6cp ||
                             (sp->confflags & CONF_ENABLE_IPV6)))
                                (cps[i])->Open(sp);
        }

        /* Send Up events to all started protos. */
        for (i = 0, mask = 1; i < IDX_COUNT; i++, mask <<= 1)
                if ((sp->lcp.protos & mask) && ((cps[i])->flags & CP_LCP) == 0)
                        (cps[i])->Up(sp);

        /* notify low-level driver of state change */
        if (sp->pp_chg)
                sp->pp_chg(sp, (int)sp->pp_phase);
        
        if (sp->pp_phase == PHASE_NETWORK)
                /* if no NCP is starting, close down */
                sppp_lcp_check_and_close(sp);
}

static void
sppp_lcp_tld(struct sppp *sp)
{
        STDDCL;
        int i;
        u_long mask;

        sp->pp_phase = PHASE_TERMINATE;

        if (debug)
                log(LOG_DEBUG, SPP_FMT "phase %s\n", SPP_ARGS(ifp),
                    sppp_phase_name(sp->pp_phase));

        /*
         * Take upper layers down.  We send the Down event first and
         * the Close second to prevent the upper layers from sending
         * ``a flurry of terminate-request packets'', as the RFC
         * describes it.
         */
        for (i = 0, mask = 1; i < IDX_COUNT; i++, mask <<= 1)
                if ((sp->lcp.protos & mask) && ((cps[i])->flags & CP_LCP) == 0) {
                        (cps[i])->Down(sp);
                        (cps[i])->Close(sp);
                }
}

static void
sppp_lcp_tls(struct sppp *sp)
{
        STDDCL;

        sp->pp_phase = PHASE_ESTABLISH;

        if (debug)
                log(LOG_DEBUG, SPP_FMT "phase %s\n", SPP_ARGS(ifp),
                    sppp_phase_name(sp->pp_phase));

        /* Notify lower layer if desired. */
        if (sp->pp_tls)
                (sp->pp_tls)(sp);
        else
                (sp->pp_up)(sp);
}

static void
sppp_lcp_tlf(struct sppp *sp)
{
        STDDCL;

        sp->pp_phase = PHASE_DEAD;
        if (debug)
                log(LOG_DEBUG, SPP_FMT "phase %s\n", SPP_ARGS(ifp),
                    sppp_phase_name(sp->pp_phase));

        /* Notify lower layer if desired. */
        if (sp->pp_tlf)
                (sp->pp_tlf)(sp);
        else
                (sp->pp_down)(sp);
}

static void
sppp_lcp_scr(struct sppp *sp)
{
        char opt[6 /* magicnum */ + 4 /* mru */ + 5 /* chap */];
        int i = 0;
        u_short authproto;

        if (sp->lcp.opts & (1 << LCP_OPT_MAGIC)) {
                if (! sp->lcp.magic)
                        sp->lcp.magic = krandom();
                opt[i++] = LCP_OPT_MAGIC;
                opt[i++] = 6;
                opt[i++] = sp->lcp.magic >> 24;
                opt[i++] = sp->lcp.magic >> 16;
                opt[i++] = sp->lcp.magic >> 8;
                opt[i++] = sp->lcp.magic;
        }

        if (sp->lcp.opts & (1 << LCP_OPT_MRU)) {
                opt[i++] = LCP_OPT_MRU;
                opt[i++] = 4;
                opt[i++] = sp->lcp.mru >> 8;
                opt[i++] = sp->lcp.mru;
        }

        if (sp->lcp.opts & (1 << LCP_OPT_AUTH_PROTO)) {
                authproto = sp->hisauth.proto;
                opt[i++] = LCP_OPT_AUTH_PROTO;
                opt[i++] = authproto == PPP_CHAP? 5: 4;
                opt[i++] = authproto >> 8;
                opt[i++] = authproto;
                if (authproto == PPP_CHAP)
                        opt[i++] = CHAP_MD5;
        }

        sp->confid[IDX_LCP] = ++sp->pp_seq[IDX_LCP];
        sppp_cp_send (sp, PPP_LCP, CONF_REQ, sp->confid[IDX_LCP], i, &opt);
}

/*
 * Check the open NCPs, return true if at least one NCP is open.
 */
static int
sppp_ncp_check(struct sppp *sp)
{
        int i, mask;

        for (i = 0, mask = 1; i < IDX_COUNT; i++, mask <<= 1)
                if ((sp->lcp.protos & mask) && (cps[i])->flags & CP_NCP)
                        return 1;
        return 0;
}

/*
 * Re-check the open NCPs and see if we should terminate the link.
 * Called by the NCPs during their tlf action handling.
 */
static void
sppp_lcp_check_and_close(struct sppp *sp)
{

        if (sp->pp_phase < PHASE_NETWORK)
                /* don't bother, we are already going down */
                return;

        if (sppp_ncp_check(sp))
                return;

        lcp.Close(sp);
}

/*
 *--------------------------------------------------------------------------*
 *                                                                          *
 *                        The IPCP implementation.                          *
 *                                                                          *
 *--------------------------------------------------------------------------*
 */

static void
sppp_ipcp_init(struct sppp *sp)
{
        sp->ipcp.opts = 0;
        sp->ipcp.flags = 0;
        sp->state[IDX_IPCP] = STATE_INITIAL;
        sp->fail_counter[IDX_IPCP] = 0;
        sp->pp_seq[IDX_IPCP] = 0;
        sp->pp_rseq[IDX_IPCP] = 0;
        callout_init(&sp->timeout[IDX_IPCP]);
}

static void
sppp_ipcp_up(struct sppp *sp)
{
        sppp_up_event(&ipcp, sp);
}

static void
sppp_ipcp_down(struct sppp *sp)
{
        sppp_down_event(&ipcp, sp);
}

static void
sppp_ipcp_open(struct sppp *sp)
{
        STDDCL;
        u_long myaddr, hisaddr;

        sp->ipcp.flags &= ~(IPCP_HISADDR_SEEN | IPCP_MYADDR_SEEN |
                            IPCP_MYADDR_DYN | IPCP_VJ);
        sp->ipcp.opts = 0;

        sppp_get_ip_addrs(sp, &myaddr, &hisaddr, 0);
        /*
         * If we don't have his address, this probably means our
         * interface doesn't want to talk IP at all.  (This could
         * be the case if somebody wants to speak only IPX, for
         * example.)  Don't open IPCP in this case.
         */
        if (hisaddr == 0L) {
                /* XXX this message should go away */
                if (debug)
                        log(LOG_DEBUG, SPP_FMT "ipcp_open(): no IP interface\n",
                            SPP_ARGS(ifp));
                return;
        }
        if (myaddr == 0L) {
                /*
                 * I don't have an assigned address, so i need to
                 * negotiate my address.
                 */
                sp->ipcp.flags |= IPCP_MYADDR_DYN;
                sp->ipcp.opts |= (1 << IPCP_OPT_ADDRESS);
        } else
                sp->ipcp.flags |= IPCP_MYADDR_SEEN;
        if (sp->confflags & CONF_ENABLE_VJ) {
                sp->ipcp.opts |= (1 << IPCP_OPT_COMPRESSION);
                sp->ipcp.max_state = MAX_STATES - 1;
                sp->ipcp.compress_cid = 1;
        }
        sppp_open_event(&ipcp, sp);
}

static void
sppp_ipcp_close(struct sppp *sp)
{
        sppp_close_event(&ipcp, sp);
        if (sp->ipcp.flags & IPCP_MYADDR_DYN)
                /*
                 * My address was dynamic, clear it again.
                 */
                sppp_set_ip_addr(sp, 0L);
}

static void
sppp_ipcp_TO(void *cookie)
{
        sppp_to_event(&ipcp, (struct sppp *)cookie);
}

/*
 * Analyze a configure request.  Return true if it was agreeable, and
 * caused action sca, false if it has been rejected or nak'ed, and
 * caused action scn.  (The return value is used to make the state
 * transition decision in the state automaton.)
 */
static int
sppp_ipcp_RCR(struct sppp *sp, struct lcp_header *h, int len)
{
        u_char *buf, *r, *p;
        struct ifnet *ifp = &sp->pp_if;
        int rlen, origlen, debug = ifp->if_flags & IFF_DEBUG;
        u_long hisaddr, desiredaddr;
        int gotmyaddr = 0;
        int desiredcomp;

        len -= 4;
        origlen = len;
        /*
         * Make sure to allocate a buf that can at least hold a
         * conf-nak with an `address' option.  We might need it below.
         */
        buf = r = kmalloc ((len < 6? 6: len), M_TEMP, M_INTWAIT);

        /* pass 1: see if we can recognize them */
        if (debug)
                log(LOG_DEBUG, SPP_FMT "ipcp parse opts: ",
                    SPP_ARGS(ifp));
        p = (void*) (h+1);
        for (rlen=0; len>1 && p[1]; len-=p[1], p+=p[1]) {
                /* Sanity check option length */
                if (p[1] > len) {
                        /* XXX should we just RXJ? */
                        log(-1, "%s: malicious IPCP option received, dropping\n",
                            ifp->if_xname);
                        goto drop;
                }
                if (debug)
                        log(-1, " %s ", sppp_ipcp_opt_name(*p));
                switch (*p) {
                case IPCP_OPT_COMPRESSION:
                        if (!(sp->confflags & CONF_ENABLE_VJ)) {
                                /* VJ compression administratively disabled */
                                if (debug)
                                        log(-1, "[locally disabled] ");
                                break;
                        }
                        /*
                         * In theory, we should only conf-rej an
                         * option that is shorter than RFC 1618
                         * requires (i.e. < 4), and should conf-nak
                         * anything else that is not VJ.  However,
                         * since our algorithm always uses the
                         * original option to NAK it with new values,
                         * things would become more complicated.  In
                         * pratice, the only commonly implemented IP
                         * compression option is VJ anyway, so the
                         * difference is negligible.
                         */
                        if (len >= 6 && p[1] == 6) {
                                /*
                                 * correctly formed compression option
                                 * that could be VJ compression
                                 */
                                continue;
                        }
                        if (debug)
                                log(-1, "optlen %d [invalid/unsupported] ",
                                    p[1]);
                        break;
                case IPCP_OPT_ADDRESS:
                        if (len >= 6 && p[1] == 6) {
                                /* correctly formed address option */
                                continue;
                        }
                        if (debug)
                                log(-1, "[invalid] ");
                        break;
                default:
                        /* Others not supported. */
                        if (debug)
                                log(-1, "[rej] ");
                        break;
                }
                /* Add the option to rejected list. */
                bcopy (p, r, p[1]);
                r += p[1];
                rlen += p[1];
        }
        if (rlen) {
                if (debug)
                        log(-1, " send conf-rej\n");
                sppp_cp_send (sp, PPP_IPCP, CONF_REJ, h->ident, rlen, buf);
                return 0;
        } else if (debug)
                log(-1, "\n");

        /* pass 2: parse option values */
        sppp_get_ip_addrs(sp, 0, &hisaddr, 0);
        if (debug)
                log(LOG_DEBUG, SPP_FMT "ipcp parse opt values: ",
                       SPP_ARGS(ifp));
        p = (void*) (h+1);
        len = origlen;
        for (rlen=0; len>1 && p[1]; len-=p[1], p+=p[1]) {
                if (debug)
                        log(-1, " %s ", sppp_ipcp_opt_name(*p));
                switch (*p) {
                case IPCP_OPT_COMPRESSION:
                        desiredcomp = p[2] << 8 | p[3];
                        /* We only support VJ */
                        if (desiredcomp == IPCP_COMP_VJ) {
                                if (debug)
                                        log(-1, "VJ [ack] ");
                                sp->ipcp.flags |= IPCP_VJ;
                                sl_compress_init(sp->pp_comp, p[4]);
                                sp->ipcp.max_state = p[4];
                                sp->ipcp.compress_cid = p[5];
                                continue;
                        }
                        if (debug)
                                log(-1, "compproto %#04x [not supported] ",
                                    desiredcomp);
                        p[2] = IPCP_COMP_VJ >> 8;
                        p[3] = IPCP_COMP_VJ;
                        p[4] = sp->ipcp.max_state;
                        p[5] = sp->ipcp.compress_cid;
                        break;
                case IPCP_OPT_ADDRESS:
                        /* This is the address he wants in his end */
                        desiredaddr = p[2] << 24 | p[3] << 16 |
                                p[4] << 8 | p[5];
                        if (desiredaddr == hisaddr ||
                            (hisaddr >= 1 && hisaddr <= 254 && desiredaddr != 0)) {
                                /*
                                 * Peer's address is same as our value,
                                 * or we have set it to 0.0.0.* to
                                 * indicate that we do not really care,
                                 * this is agreeable.  Gonna conf-ack
                                 * it.
                                 */
                                if (debug)
                                        log(-1, "%s [ack] ",
                                                sppp_dotted_quad(hisaddr));
                                /* record that we've seen it already */
                                sp->ipcp.flags |= IPCP_HISADDR_SEEN;
                                continue;
                        }
                        /*
                         * The address wasn't agreeable.  This is either
                         * he sent us 0.0.0.0, asking to assign him an
                         * address, or he send us another address not
                         * matching our value.  Either case, we gonna
                         * conf-nak it with our value.
                         * XXX: we should "rej" if hisaddr == 0
                         */
                        if (debug) {
                                if (desiredaddr == 0)
                                        log(-1, "[addr requested] ");
                                else
                                        log(-1, "%s [not agreed] ",
                                                sppp_dotted_quad(desiredaddr));

                        }
                        p[2] = hisaddr >> 24;
                        p[3] = hisaddr >> 16;
                        p[4] = hisaddr >> 8;
                        p[5] = hisaddr;
                        break;
                }
                /* Add the option to nak'ed list. */
                bcopy (p, r, p[1]);
                r += p[1];
                rlen += p[1];
        }

        /*
         * If we are about to conf-ack the request, but haven't seen
         * his address so far, gonna conf-nak it instead, with the
         * `address' option present and our idea of his address being
         * filled in there, to request negotiation of both addresses.
         *
         * XXX This can result in an endless req - nak loop if peer
         * doesn't want to send us his address.  Q: What should we do
         * about it?  XXX  A: implement the max-failure counter.
         */
        if (rlen == 0 && !(sp->ipcp.flags & IPCP_HISADDR_SEEN) && !gotmyaddr) {
                buf[0] = IPCP_OPT_ADDRESS;
                buf[1] = 6;
                buf[2] = hisaddr >> 24;
                buf[3] = hisaddr >> 16;
                buf[4] = hisaddr >> 8;
                buf[5] = hisaddr;
                rlen = 6;
                if (debug)
                        log(-1, "still need hisaddr ");
        }

        if (rlen) {
                if (debug)
                        log(-1, " send conf-nak\n");
                sppp_cp_send (sp, PPP_IPCP, CONF_NAK, h->ident, rlen, buf);
        } else {
                if (debug)
                        log(-1, " send conf-ack\n");
                sppp_cp_send (sp, PPP_IPCP, CONF_ACK,
                              h->ident, origlen, h+1);
        }

        kfree (buf, M_TEMP);
        return (rlen == 0);

drop:
        kfree(buf, M_TEMP);
        return (-1);
}

/*
 * Analyze the IPCP Configure-Reject option list, and adjust our
 * negotiation.
 */
static void
sppp_ipcp_RCN_rej(struct sppp *sp, struct lcp_header *h, int len)
{
        u_char *buf, *p;
        struct ifnet *ifp = &sp->pp_if;
        int debug = ifp->if_flags & IFF_DEBUG;

        len -= 4;
        buf = kmalloc (len, M_TEMP, M_INTWAIT);

        if (debug)
                log(LOG_DEBUG, SPP_FMT "ipcp rej opts: ",
                    SPP_ARGS(ifp));

        p = (void*) (h+1);
        for (; len > 1 && p[1]; len -= p[1], p += p[1]) {
                /* Sanity check option length */
                if (p[1] > len) {
                        /* XXX should we just RXJ? */
                        log(-1, "%s: malicious IPCP option received, dropping\n",
                            ifp->if_xname);
                        goto drop;
                }
                if (debug)
                        log(-1, " %s ", sppp_ipcp_opt_name(*p));
                switch (*p) {
                case IPCP_OPT_COMPRESSION:
                        sp->ipcp.opts &= ~(1 << IPCP_OPT_COMPRESSION);
                        break;
                case IPCP_OPT_ADDRESS:
                        /*
                         * Peer doesn't grok address option.  This is
                         * bad.  XXX  Should we better give up here?
                         * XXX We could try old "addresses" option...
                         */
                        sp->ipcp.opts &= ~(1 << IPCP_OPT_ADDRESS);
                        break;
                }
        }
        if (debug)
                log(-1, "\n");
drop:
        kfree (buf, M_TEMP);
        return;
}

/*
 * Analyze the IPCP Configure-NAK option list, and adjust our
 * negotiation.
 */
static void
sppp_ipcp_RCN_nak(struct sppp *sp, struct lcp_header *h, int len)
{
        u_char *buf, *p;
        struct ifnet *ifp = &sp->pp_if;
        int debug = ifp->if_flags & IFF_DEBUG;
        int desiredcomp;
        u_long wantaddr;

        len -= 4;
        buf = kmalloc (len, M_TEMP, M_INTWAIT);

        if (debug)
                log(LOG_DEBUG, SPP_FMT "ipcp nak opts: ",
                    SPP_ARGS(ifp));

        p = (void*) (h+1);
        for (; len > 1 && p[1]; len -= p[1], p += p[1]) {
                /* Sanity check option length */
                if (p[1] > len) {
                        /* XXX should we just RXJ? */
                        log(-1, "%s: malicious IPCP option received, dropping\n",
                            ifp->if_xname);
                        return;
                }
                if (debug)
                        log(-1, " %s ", sppp_ipcp_opt_name(*p));
                switch (*p) {
                case IPCP_OPT_COMPRESSION:
                        if (len >= 6 && p[1] == 6) {
                                desiredcomp = p[2] << 8 | p[3];
                                if (debug)
                                        log(-1, "[wantcomp %#04x] ",
                                                desiredcomp);
                                if (desiredcomp == IPCP_COMP_VJ) {
                                        sl_compress_init(sp->pp_comp, p[4]);
                                        sp->ipcp.max_state = p[4];
                                        sp->ipcp.compress_cid = p[5];
                                        if (debug)
                                                log(-1, "[agree] ");
                                } else
                                        sp->ipcp.opts &=
                                                ~(1 << IPCP_OPT_COMPRESSION);
                        }
                        break;
                case IPCP_OPT_ADDRESS:
                        /*
                         * Peer doesn't like our local IP address.  See
                         * if we can do something for him.  We'll drop
                         * him our address then.
                         */
                        if (len >= 6 && p[1] == 6) {
                                wantaddr = p[2] << 24 | p[3] << 16 |
                                        p[4] << 8 | p[5];
                                sp->ipcp.opts |= (1 << IPCP_OPT_ADDRESS);
                                if (debug)
                                        log(-1, "[wantaddr %s] ",
                                               sppp_dotted_quad(wantaddr));
                                /*
                                 * When doing dynamic address assignment,
                                 * we accept his offer.  Otherwise, we
                                 * ignore it and thus continue to negotiate
                                 * our already existing value.
                                 * XXX: Bogus, if he said no once, he'll
                                 * just say no again, might as well die.
                                 */
                                if (sp->ipcp.flags & IPCP_MYADDR_DYN) {
                                        sppp_set_ip_addr(sp, wantaddr);
                                        if (debug)
                                                log(-1, "[agree] ");
                                        sp->ipcp.flags |= IPCP_MYADDR_SEEN;
                                }
                        }
                        break;
                }
        }
        if (debug)
                log(-1, "\n");
        kfree (buf, M_TEMP);
        return;
}

static void
sppp_ipcp_tlu(struct sppp *sp)
{
        /* we are up - notify isdn daemon */
        if (sp->pp_con)
                sp->pp_con(sp);
}

static void
sppp_ipcp_tld(struct sppp *sp)
{
}

static void
sppp_ipcp_tls(struct sppp *sp)
{
        /* indicate to LCP that it must stay alive */
        sp->lcp.protos |= (1 << IDX_IPCP);
}

static void
sppp_ipcp_tlf(struct sppp *sp)
{
        /* we no longer need LCP */
        sp->lcp.protos &= ~(1 << IDX_IPCP);
        sppp_lcp_check_and_close(sp);
}

static void
sppp_ipcp_scr(struct sppp *sp)
{
        char opt[6 /* compression */ + 6 /* address */];
        u_long ouraddr;
        int i = 0;

        if (sp->ipcp.opts & (1 << IPCP_OPT_COMPRESSION)) {
                opt[i++] = IPCP_OPT_COMPRESSION;
                opt[i++] = 6;
                opt[i++] = IPCP_COMP_VJ >> 8;
                opt[i++] = IPCP_COMP_VJ;
                opt[i++] = sp->ipcp.max_state;
                opt[i++] = sp->ipcp.compress_cid;
        }
        if (sp->ipcp.opts & (1 << IPCP_OPT_ADDRESS)) {
                sppp_get_ip_addrs(sp, &ouraddr, 0, 0);
                opt[i++] = IPCP_OPT_ADDRESS;
                opt[i++] = 6;
                opt[i++] = ouraddr >> 24;
                opt[i++] = ouraddr >> 16;
                opt[i++] = ouraddr >> 8;
                opt[i++] = ouraddr;
        }

        sp->confid[IDX_IPCP] = ++sp->pp_seq[IDX_IPCP];
        sppp_cp_send(sp, PPP_IPCP, CONF_REQ, sp->confid[IDX_IPCP], i, &opt);
}

/*
 *--------------------------------------------------------------------------*
 *                                                                          *
 *                      The IPv6CP implementation.                          *
 *                                                                          *
 *--------------------------------------------------------------------------*
 */

#ifdef INET6
static void
sppp_ipv6cp_init(struct sppp *sp)
{
        sp->ipv6cp.opts = 0;
        sp->ipv6cp.flags = 0;
        sp->state[IDX_IPV6CP] = STATE_INITIAL;
        sp->fail_counter[IDX_IPV6CP] = 0;
        sp->pp_seq[IDX_IPV6CP] = 0;
        sp->pp_rseq[IDX_IPV6CP] = 0;
        callout_init(&sp->timeout[IDX_IPV6CP]);
}

static void
sppp_ipv6cp_up(struct sppp *sp)
{
        sppp_up_event(&ipv6cp, sp);
}

static void
sppp_ipv6cp_down(struct sppp *sp)
{
        sppp_down_event(&ipv6cp, sp);
}

static void
sppp_ipv6cp_open(struct sppp *sp)
{
        STDDCL;
        struct in6_addr myaddr, hisaddr;

#ifdef IPV6CP_MYIFID_DYN
        sp->ipv6cp.flags &= ~(IPV6CP_MYIFID_SEEN|IPV6CP_MYIFID_DYN);
#else
        sp->ipv6cp.flags &= ~IPV6CP_MYIFID_SEEN;
#endif

        sppp_get_ip6_addrs(sp, &myaddr, &hisaddr, 0);
        /*
         * If we don't have our address, this probably means our
         * interface doesn't want to talk IPv6 at all.  (This could
         * be the case if somebody wants to speak only IPX, for
         * example.)  Don't open IPv6CP in this case.
         */
        if (IN6_IS_ADDR_UNSPECIFIED(&myaddr)) {
                /* XXX this message should go away */
                if (debug)
                        log(LOG_DEBUG, SPP_FMT "ipv6cp_open(): no IPv6 interface\n",
                            SPP_ARGS(ifp));
                return;
        }

        sp->ipv6cp.flags |= IPV6CP_MYIFID_SEEN;
        sp->ipv6cp.opts |= (1 << IPV6CP_OPT_IFID);
        sppp_open_event(&ipv6cp, sp);
}

static void
sppp_ipv6cp_close(struct sppp *sp)
{
        sppp_close_event(&ipv6cp, sp);
}

static void
sppp_ipv6cp_TO(void *cookie)
{
        sppp_to_event(&ipv6cp, (struct sppp *)cookie);
}

/*
 * Analyze a configure request.  Return true if it was agreeable, and
 * caused action sca, false if it has been rejected or nak'ed, and
 * caused action scn.  (The return value is used to make the state
 * transition decision in the state automaton.)
 */
static int
sppp_ipv6cp_RCR(struct sppp *sp, struct lcp_header *h, int len)
{
        u_char *buf, *r, *p;
        struct ifnet *ifp = &sp->pp_if;
        int rlen, origlen, debug = ifp->if_flags & IFF_DEBUG;
        struct in6_addr myaddr, desiredaddr, suggestaddr;
        int ifidcount;
        int type;
        int collision, nohisaddr;

        len -= 4;
        origlen = len;
        /*
         * Make sure to allocate a buf that can at least hold a
         * conf-nak with an `address' option.  We might need it below.
         */
        buf = r = kmalloc ((len < 6? 6: len), M_TEMP, M_INTWAIT);

        /* pass 1: see if we can recognize them */
        if (debug)
                log(LOG_DEBUG, SPP_FMT "ipv6cp parse opts:",
                    SPP_ARGS(ifp));
        p = (void*) (h+1);
        ifidcount = 0;
        for (rlen=0; len>1 && p[1]; len-=p[1], p+=p[1]) {
                /* Sanity check option length */
                if (p[1] > len) {
                        /* XXX just RXJ? */
                        log(-1, "%s: received malicious IPCPv6 option, "
                            "dropping\n", ifp->if_xname);
                        goto drop;
                }
                if (debug)
                        log(-1, " %s", sppp_ipv6cp_opt_name(*p));
                switch (*p) {
                case IPV6CP_OPT_IFID:
                        if (len >= 10 && p[1] == 10 && ifidcount == 0) {
                                /* correctly formed address option */
                                ifidcount++;
                                continue;
                        }
                        if (debug)
                                log(-1, " [invalid]");
                        break;
#ifdef notyet
                case IPV6CP_OPT_COMPRESSION:
                        if (len >= 4 && p[1] >= 4) {
                                /* correctly formed compress option */
                                continue;
                        }
                        if (debug)
                                log(-1, " [invalid]");
                        break;
#endif
                default:
                        /* Others not supported. */
                        if (debug)
                                log(-1, " [rej]");
                        break;
                }
                /* Add the option to rejected list. */
                bcopy (p, r, p[1]);
                r += p[1];
                rlen += p[1];
        }
        if (rlen) {
                if (debug)
                        log(-1, " send conf-rej\n");
                sppp_cp_send (sp, PPP_IPV6CP, CONF_REJ, h->ident, rlen, buf);
                goto end;
        } else if (debug)
                log(-1, "\n");

        /* pass 2: parse option values */
        sppp_get_ip6_addrs(sp, &myaddr, 0, 0);
        if (debug)
                log(LOG_DEBUG, SPP_FMT "ipv6cp parse opt values: ",
                    SPP_ARGS(ifp));
        p = (void*) (h+1);
        len = origlen;
        type = CONF_ACK;
        for (rlen=0; len>1 && p[1]; len-=p[1], p+=p[1]) {
                if (debug)
                        log(-1, " %s", sppp_ipv6cp_opt_name(*p));
                switch (*p) {
#ifdef notyet
                case IPV6CP_OPT_COMPRESSION:
                        continue;
#endif
                case IPV6CP_OPT_IFID:
                        bzero(&desiredaddr, sizeof(desiredaddr));
                        bcopy(&p[2], &desiredaddr.s6_addr[8], 8);
                        collision = (bcmp(&desiredaddr.s6_addr[8],
                                          &myaddr.s6_addr[8], 8) == 0);
                        nohisaddr = IN6_IS_ADDR_UNSPECIFIED(&desiredaddr);

                        desiredaddr.s6_addr16[0] = htons(0xfe80);
                        desiredaddr.s6_addr16[1] = htons(sp->pp_if.if_index);

                        if (!collision && !nohisaddr) {
                                /* no collision, hisaddr known - Conf-Ack */
                                type = CONF_ACK;

                                if (debug) {
                                        log(-1, " %s [%s]",
                                               ip6_sprintf(&desiredaddr),
                                               sppp_cp_type_name(type));
                                }
                                continue;
                        }

                        bzero(&suggestaddr, sizeof(suggestaddr));
                        if (collision && nohisaddr) {
                                /* collision, hisaddr unknown - Conf-Rej */
                                type = CONF_REJ;
                                bzero(&p[2], 8);
                        } else {
                                /*
                                 * - no collision, hisaddr unknown, or
                                 * - collision, hisaddr known
                                 * Conf-Nak, suggest hisaddr
                                 */
                                type = CONF_NAK;
                                sppp_suggest_ip6_addr(sp, &suggestaddr);
                                bcopy(&suggestaddr.s6_addr[8], &p[2], 8);
                        }
                        if (debug)
                                log(-1, " %s [%s]", ip6_sprintf(&desiredaddr),
                                       sppp_cp_type_name(type));
                        break;
                }
                /* Add the option to nak'ed list. */
                bcopy (p, r, p[1]);
                r += p[1];
                rlen += p[1];
        }

        if (rlen == 0 && type == CONF_ACK) {
                if (debug)
                        log(-1, " send %s\n", sppp_cp_type_name(type));
                sppp_cp_send (sp, PPP_IPV6CP, type, h->ident, origlen, h+1);
        } else {
#ifdef DIAGNOSTIC
                if (type == CONF_ACK)
                        panic("IPv6CP RCR: CONF_ACK with non-zero rlen");
#endif

                if (debug) {
                        log(-1, " send %s suggest %s\n",
                               sppp_cp_type_name(type), ip6_sprintf(&suggestaddr));
                }
                sppp_cp_send (sp, PPP_IPV6CP, type, h->ident, rlen, buf);
        }

 end:
        kfree (buf, M_TEMP);
        return (rlen == 0);

drop:
        kfree(buf, M_TEMP);
        return (-1);
}

/*
 * Analyze the IPv6CP Configure-Reject option list, and adjust our
 * negotiation.
 */
static void
sppp_ipv6cp_RCN_rej(struct sppp *sp, struct lcp_header *h, int len)
{
        u_char *buf, *p;
        struct ifnet *ifp = &sp->pp_if;
        int debug = ifp->if_flags & IFF_DEBUG;

        len -= 4;
        buf = kmalloc (len, M_TEMP, M_INTWAIT);

        if (debug)
                log(LOG_DEBUG, SPP_FMT "ipv6cp rej opts:",
                    SPP_ARGS(ifp));

        p = (void*) (h+1);
        for (; len > 1 && p[1]; len -= p[1], p += p[1]) {
                if (p[1] > len) {
                        /* XXX just RXJ? */
                        log(-1, "%s: received malicious IPCPv6 option, "
                            "dropping\n", ifp->if_xname);
                        goto drop;
                }
                if (debug)
                        log(-1, " %s", sppp_ipv6cp_opt_name(*p));
                switch (*p) {
                case IPV6CP_OPT_IFID:
                        /*
                         * Peer doesn't grok address option.  This is
                         * bad.  XXX  Should we better give up here?
                         */
                        sp->ipv6cp.opts &= ~(1 << IPV6CP_OPT_IFID);
                        break;
#ifdef notyet
                case IPV6CP_OPT_COMPRESS:
                        sp->ipv6cp.opts &= ~(1 << IPV6CP_OPT_COMPRESS);
                        break;
#endif
                }
        }
        if (debug)
                log(-1, "\n");
drop:
        kfree (buf, M_TEMP);
        return;
}

/*
 * Analyze the IPv6CP Configure-NAK option list, and adjust our
 * negotiation.
 */
static void
sppp_ipv6cp_RCN_nak(struct sppp *sp, struct lcp_header *h, int len)
{
        u_char *buf, *p;
        struct ifnet *ifp = &sp->pp_if;
        int debug = ifp->if_flags & IFF_DEBUG;
        struct in6_addr suggestaddr;

        len -= 4;
        buf = kmalloc (len, M_TEMP, M_INTWAIT);

        if (debug)
                log(LOG_DEBUG, SPP_FMT "ipv6cp nak opts:",
                    SPP_ARGS(ifp));

        p = (void*) (h+1);
        for (; len > 1 && p[1]; len -= p[1], p += p[1]) {
                if (p[1] > len) {
                        /* XXX just RXJ? */
                        log(-1, "%s: received malicious IPCPv6 option, "
                            "dropping\n", ifp->if_xname);
                        goto drop;
                }
                if (debug)
                        log(-1, " %s", sppp_ipv6cp_opt_name(*p));
                switch (*p) {
                case IPV6CP_OPT_IFID:
                        /*
                         * Peer doesn't like our local ifid.  See
                         * if we can do something for him.  We'll drop
                         * him our address then.
                         */
                        if (len < 10 || p[1] != 10)
                                break;
                        bzero(&suggestaddr, sizeof(suggestaddr));
                        suggestaddr.s6_addr16[0] = htons(0xfe80);
                        suggestaddr.s6_addr16[1] = htons(sp->pp_if.if_index);
                        bcopy(&p[2], &suggestaddr.s6_addr[8], 8);

                        sp->ipv6cp.opts |= (1 << IPV6CP_OPT_IFID);
                        if (debug)
                                log(-1, " [suggestaddr %s]",
                                       ip6_sprintf(&suggestaddr));
#ifdef IPV6CP_MYIFID_DYN
                        /*
                         * When doing dynamic address assignment,
                         * we accept his offer.
                         */
                        if (sp->ipv6cp.flags & IPV6CP_MYIFID_DYN) {
                                struct in6_addr lastsuggest;
                                /*
                                 * If <suggested myaddr from peer> equals to
                                 * <hisaddr we have suggested last time>,
                                 * we have a collision.  generate new random
                                 * ifid.
                                 */
                                sppp_suggest_ip6_addr(&lastsuggest);
                                if (IN6_ARE_ADDR_EQUAL(&suggestaddr,
                                                       lastsuggest)) {
                                        if (debug)
                                                log(-1, " [random]");
                                        sppp_gen_ip6_addr(sp, &suggestaddr);
                                }
                                sppp_set_ip6_addr(sp, &suggestaddr, 0);
                                if (debug)
                                        log(-1, " [agree]");
                                sp->ipv6cp.flags |= IPV6CP_MYIFID_SEEN;
                        }
#else
                        /*
                         * Since we do not do dynamic address assignment,
                         * we ignore it and thus continue to negotiate
                         * our already existing value.  This can possibly
                         * go into infinite request-reject loop.
                         *
                         * This is not likely because we normally use
                         * ifid based on MAC-address.
                         * If you have no ethernet card on the node, too bad.
                         * XXX should we use fail_counter?
                         */
#endif
                        break;
#ifdef notyet
                case IPV6CP_OPT_COMPRESS:
                        /*
                         * Peer wants different compression parameters.
                         */
                        break;
#endif
                }
        }
        if (debug)
                log(-1, "\n");
drop:
        kfree (buf, M_TEMP);
        return;
}
static void
sppp_ipv6cp_tlu(struct sppp *sp)
{
        /* we are up - notify isdn daemon */
        if (sp->pp_con)
                sp->pp_con(sp);
}

static void
sppp_ipv6cp_tld(struct sppp *sp)
{
}

static void
sppp_ipv6cp_tls(struct sppp *sp)
{
        /* indicate to LCP that it must stay alive */
        sp->lcp.protos |= (1 << IDX_IPV6CP);
}

static void
sppp_ipv6cp_tlf(struct sppp *sp)
{

#if 0   /* need #if 0 to close IPv6CP properly */
        /* we no longer need LCP */
        sp->lcp.protos &= ~(1 << IDX_IPV6CP);
        sppp_lcp_check_and_close(sp);
#endif
}

static void
sppp_ipv6cp_scr(struct sppp *sp)
{
        char opt[10 /* ifid */ + 4 /* compression, minimum */];
        struct in6_addr ouraddr;
        int i = 0;

        if (sp->ipv6cp.opts & (1 << IPV6CP_OPT_IFID)) {
                sppp_get_ip6_addrs(sp, &ouraddr, 0, 0);
                opt[i++] = IPV6CP_OPT_IFID;
                opt[i++] = 10;
                bcopy(&ouraddr.s6_addr[8], &opt[i], 8);
                i += 8;
        }

#ifdef notyet
        if (sp->ipv6cp.opts & (1 << IPV6CP_OPT_COMPRESSION)) {
                opt[i++] = IPV6CP_OPT_COMPRESSION;
                opt[i++] = 4;
                opt[i++] = 0;   /* TBD */
                opt[i++] = 0;   /* TBD */
                /* variable length data may follow */
        }
#endif

        sp->confid[IDX_IPV6CP] = ++sp->pp_seq[IDX_IPV6CP];
        sppp_cp_send(sp, PPP_IPV6CP, CONF_REQ, sp->confid[IDX_IPV6CP], i, &opt);
}
#else /*INET6*/
static void
sppp_ipv6cp_init(struct sppp *sp)
{
}

static void
sppp_ipv6cp_up(struct sppp *sp)
{
}

static void
sppp_ipv6cp_down(struct sppp *sp)
{
}


static void
sppp_ipv6cp_open(struct sppp *sp)
{
}

static void
sppp_ipv6cp_close(struct sppp *sp)
{
}

static void
sppp_ipv6cp_TO(void *sp)
{
}

static int
sppp_ipv6cp_RCR(struct sppp *sp, struct lcp_header *h, int len)
{
        return 0;
}

static void
sppp_ipv6cp_RCN_rej(struct sppp *sp, struct lcp_header *h, int len)
{
}

static void
sppp_ipv6cp_RCN_nak(struct sppp *sp, struct lcp_header *h, int len)
{
}

static void
sppp_ipv6cp_tlu(struct sppp *sp)
{
}

static void
sppp_ipv6cp_tld(struct sppp *sp)
{
}

static void
sppp_ipv6cp_tls(struct sppp *sp)
{
}

static void
sppp_ipv6cp_tlf(struct sppp *sp)
{
}

static void
sppp_ipv6cp_scr(struct sppp *sp)
{
}
#endif /*INET6*/

/*
 *--------------------------------------------------------------------------*
 *                                                                          *
 *                        The CHAP implementation.                          *
 *                                                                          *
 *--------------------------------------------------------------------------*
 */

/*
 * The authentication protocols don't employ a full-fledged state machine as
 * the control protocols do, since they do have Open and Close events, but
 * not Up and Down, nor are they explicitly terminated.  Also, use of the
 * authentication protocols may be different in both directions (this makes
 * sense, think of a machine that never accepts incoming calls but only
 * calls out, it doesn't require the called party to authenticate itself).
 *
 * Our state machine for the local authentication protocol (we are requesting
 * the peer to authenticate) looks like:
 *
 *                                                  RCA-
 *            +--------------------------------------------+
 *            V                                     scn,tld|
 *        +--------+                           Close   +---------+ RCA+
 *        |        |<----------------------------------|         |------+
 *   +--->| Closed |                            TO*    | Opened  | sca  |
 *   |    |        |-----+                     +-------|         |<-----+
 *   |    +--------+ irc |                     |       +---------+
 *   |      ^            |                     |           ^
 *   |      |            |                     |           |
 *   |      |            |                     |           |
 *   |   TO-|            |                     |           |
 *   |      |tld  TO+    V                     |           |
 *   |      |   +------->+                     |           |
 *   |      |   |        |                     |           |
 *   |    +--------+     V                     |           |
 *   |    |        |<----+<--------------------+           |
 *   |    | Req-   | scr                                   |
 *   |    | Sent   |                                       |
 *   |    |        |                                       |
 *   |    +--------+                                       |
 *   | RCA- |   | RCA+                                     |
 *   +------+   +------------------------------------------+
 *   scn,tld      sca,irc,ict,tlu
 *
 *
 *   with:
 *
 *      Open:   LCP reached authentication phase
 *      Close:  LCP reached terminate phase
 *
 *      RCA+:   received reply (pap-req, chap-response), acceptable
 *      RCN:    received reply (pap-req, chap-response), not acceptable
 *      TO+:    timeout with restart counter >= 0
 *      TO-:    timeout with restart counter < 0
 *      TO*:    reschedule timeout for CHAP
 *
 *      scr:    send request packet (none for PAP, chap-challenge)
 *      sca:    send ack packet (pap-ack, chap-success)
 *      scn:    send nak packet (pap-nak, chap-failure)
 *      ict:    initialize re-challenge timer (CHAP only)
 *
 *      tlu:    this-layer-up, LCP reaches network phase
 *      tld:    this-layer-down, LCP enters terminate phase
 *
 * Note that in CHAP mode, after sending a new challenge, while the state
 * automaton falls back into Req-Sent state, it doesn't signal a tld
 * event to LCP, so LCP remains in network phase.  Only after not getting
 * any response (or after getting an unacceptable response), CHAP closes,
 * causing LCP to enter terminate phase.
 *
 * With PAP, there is no initial request that can be sent.  The peer is
 * expected to send one based on the successful negotiation of PAP as
 * the authentication protocol during the LCP option negotiation.
 *
 * Incoming authentication protocol requests (remote requests
 * authentication, we are peer) don't employ a state machine at all,
 * they are simply answered.  Some peers [Ascend P50 firmware rev
 * 4.50] react allergically when sending IPCP requests while they are
 * still in authentication phase (thereby violating the standard that
 * demands that these NCP packets are to be discarded), so we keep
 * track of the peer demanding us to authenticate, and only proceed to
 * phase network once we've seen a positive acknowledge for the
 * authentication.
 */

/*
 * Handle incoming CHAP packets.
 */
static void
sppp_chap_input(struct sppp *sp, struct mbuf *m)
{
        STDDCL;
        struct lcp_header *h;
        int len;
        u_char *value, *name, digest[AUTHKEYLEN], dsize;
        int value_len, name_len;
        MD5_CTX ctx;

        len = m->m_pkthdr.len;
        if (len < 4) {
                if (debug)
                        log(LOG_DEBUG,
                            SPP_FMT "chap invalid packet length: %d bytes\n",
                            SPP_ARGS(ifp), len);
                return;
        }
        h = mtod (m, struct lcp_header*);
        if (len > ntohs (h->len))
                len = ntohs (h->len);

        switch (h->type) {
        /* challenge, failure and success are his authproto */
        case CHAP_CHALLENGE:
                value = 1 + (u_char*)(h+1);
                value_len = value[-1];
                name = value + value_len;
                name_len = len - value_len - 5;
                if (name_len < 0) {
                        if (debug) {
                                log(LOG_DEBUG,
                                    SPP_FMT "chap corrupted challenge "
                                    "<%s id=0x%x len=%d",
                                    SPP_ARGS(ifp),
                                    sppp_auth_type_name(PPP_CHAP, h->type),
                                    h->ident, ntohs(h->len));
                                sppp_print_bytes((u_char*) (h+1), len-4);
                                log(-1, ">\n");
                        }
                        break;
                }

                if (debug) {
                        log(LOG_DEBUG,
                            SPP_FMT "chap input <%s id=0x%x len=%d name=",
                            SPP_ARGS(ifp),
                            sppp_auth_type_name(PPP_CHAP, h->type), h->ident,
                            ntohs(h->len));
                        sppp_print_string((char*) name, name_len);
                        log(-1, " value-size=%d value=", value_len);
                        sppp_print_bytes(value, value_len);
                        log(-1, ">\n");
                }

                /* Compute reply value. */
                MD5Init(&ctx);
                MD5Update(&ctx, &h->ident, 1);
                MD5Update(&ctx, sp->myauth.secret,
                          strnlen(sp->myauth.secret, AUTHKEYLEN));
                MD5Update(&ctx, value, value_len);
                MD5Final(digest, &ctx);
                dsize = sizeof digest;

                sppp_auth_send(&chap, sp, CHAP_RESPONSE, h->ident,
                               sizeof dsize, (const char *)&dsize,
                               sizeof digest, digest,
                               (size_t)strnlen(sp->myauth.name, AUTHNAMELEN),
                               sp->myauth.name,
                               0);
                break;

        case CHAP_SUCCESS:
                if (debug) {
                        log(LOG_DEBUG, SPP_FMT "chap success",
                            SPP_ARGS(ifp));
                        if (len > 4) {
                                log(-1, ": ");
                                sppp_print_string((char*)(h + 1), len - 4);
                        }
                        log(-1, "\n");
                }

                crit_enter();

                sp->pp_flags &= ~PP_NEEDAUTH;
                if (sp->myauth.proto == PPP_CHAP &&
                    (sp->lcp.opts & (1 << LCP_OPT_AUTH_PROTO)) &&
                    (sp->lcp.protos & (1 << IDX_CHAP)) == 0) {
                        /*
                         * We are authenticator for CHAP but didn't
                         * complete yet.  Leave it to tlu to proceed
                         * to network phase.
                         */
                        crit_exit();
                        break;
                }
                crit_exit();
                sppp_phase_network(sp);
                break;

        case CHAP_FAILURE:
                if (debug) {
                        log(LOG_INFO, SPP_FMT "chap failure",
                            SPP_ARGS(ifp));
                        if (len > 4) {
                                log(-1, ": ");
                                sppp_print_string((char*)(h + 1), len - 4);
                        }
                        log(-1, "\n");
                } else
                        log(LOG_INFO, SPP_FMT "chap failure\n",
                            SPP_ARGS(ifp));
                /* await LCP shutdown by authenticator */
                break;

        /* response is my authproto */
        case CHAP_RESPONSE:
                value = 1 + (u_char*)(h+1);
                value_len = value[-1];
                name = value + value_len;
                name_len = len - value_len - 5;
                if (name_len < 0) {
                        if (debug) {
                                log(LOG_DEBUG,
                                    SPP_FMT "chap corrupted response "
                                    "<%s id=0x%x len=%d",
                                    SPP_ARGS(ifp),
                                    sppp_auth_type_name(PPP_CHAP, h->type),
                                    h->ident, ntohs(h->len));
                                sppp_print_bytes((u_char*)(h+1), len-4);
                                log(-1, ">\n");
                        }
                        break;
                }
                if (h->ident != sp->confid[IDX_CHAP]) {
                        if (debug)
                                log(LOG_DEBUG,
                                    SPP_FMT "chap dropping response for old ID "
                                    "(got %d, expected %d)\n",
                                    SPP_ARGS(ifp),
                                    h->ident, sp->confid[IDX_CHAP]);
                        break;
                }
                if (name_len != strnlen(sp->hisauth.name, AUTHNAMELEN)
                    || bcmp(name, sp->hisauth.name, name_len) != 0) {
                        log(LOG_INFO, SPP_FMT "chap response, his name ",
                            SPP_ARGS(ifp));
                        sppp_print_string(name, name_len);
                        log(-1, " != expected ");
                        sppp_print_string(sp->hisauth.name,
                                          strnlen(sp->hisauth.name, AUTHNAMELEN));
                        log(-1, "\n");
                }
                if (debug) {
                        log(LOG_DEBUG, SPP_FMT "chap input(%s) "
                            "<%s id=0x%x len=%d name=",
                            SPP_ARGS(ifp),
                            sppp_state_name(sp->state[IDX_CHAP]),
                            sppp_auth_type_name(PPP_CHAP, h->type),
                            h->ident, ntohs (h->len));
                        sppp_print_string((char*)name, name_len);
                        log(-1, " value-size=%d value=", value_len);
                        sppp_print_bytes(value, value_len);
                        log(-1, ">\n");
                }
                if (value_len != AUTHKEYLEN) {
                        if (debug)
                                log(LOG_DEBUG,
                                    SPP_FMT "chap bad hash value length: "
                                    "%d bytes, should be %d\n",
                                    SPP_ARGS(ifp), value_len,
                                    AUTHKEYLEN);
                        break;
                }

                MD5Init(&ctx);
                MD5Update(&ctx, &h->ident, 1);
                MD5Update(&ctx, sp->hisauth.secret,
                          strnlen(sp->hisauth.secret, AUTHKEYLEN));
                MD5Update(&ctx, sp->myauth.challenge, AUTHKEYLEN);
                MD5Final(digest, &ctx);

#define FAILMSG "Failed..."
#define SUCCMSG "Welcome!"

                if (value_len != sizeof digest ||
                    bcmp(digest, value, value_len) != 0) {
                        /* action scn, tld */
                        sppp_auth_send(&chap, sp, CHAP_FAILURE, h->ident,
                                       sizeof(FAILMSG) - 1, (u_char *)FAILMSG,
                                       0);
                        chap.tld(sp);
                        break;
                }
                /* action sca, perhaps tlu */
                if (sp->state[IDX_CHAP] == STATE_REQ_SENT ||
                    sp->state[IDX_CHAP] == STATE_OPENED)
                        sppp_auth_send(&chap, sp, CHAP_SUCCESS, h->ident,
                                       sizeof(SUCCMSG) - 1, (u_char *)SUCCMSG,
                                       0);
                if (sp->state[IDX_CHAP] == STATE_REQ_SENT) {
                        sppp_cp_change_state(&chap, sp, STATE_OPENED);
                        chap.tlu(sp);
                }
                break;

        default:
                /* Unknown CHAP packet type -- ignore. */
                if (debug) {
                        log(LOG_DEBUG, SPP_FMT "chap unknown input(%s) "
                            "<0x%x id=0x%xh len=%d",
                            SPP_ARGS(ifp),
                            sppp_state_name(sp->state[IDX_CHAP]),
                            h->type, h->ident, ntohs(h->len));
                        sppp_print_bytes((u_char*)(h+1), len-4);
                        log(-1, ">\n");
                }
                break;

        }
}

static void
sppp_chap_init(struct sppp *sp)
{
        /* Chap doesn't have STATE_INITIAL at all. */
        sp->state[IDX_CHAP] = STATE_CLOSED;
        sp->fail_counter[IDX_CHAP] = 0;
        sp->pp_seq[IDX_CHAP] = 0;
        sp->pp_rseq[IDX_CHAP] = 0;
        callout_init(&sp->timeout[IDX_CHAP]);
}

static void
sppp_chap_open(struct sppp *sp)
{
        if (sp->myauth.proto == PPP_CHAP &&
            (sp->lcp.opts & (1 << LCP_OPT_AUTH_PROTO)) != 0) {
                /* we are authenticator for CHAP, start it */
                chap.scr(sp);
                sp->rst_counter[IDX_CHAP] = sp->lcp.max_configure;
                sppp_cp_change_state(&chap, sp, STATE_REQ_SENT);
        }
        /* nothing to be done if we are peer, await a challenge */
}

static void
sppp_chap_close(struct sppp *sp)
{
        if (sp->state[IDX_CHAP] != STATE_CLOSED)
                sppp_cp_change_state(&chap, sp, STATE_CLOSED);
}

static void
sppp_chap_TO(void *cookie)
{
        struct sppp *sp = (struct sppp *)cookie;
        STDDCL;

        crit_enter();

        if (debug)
                log(LOG_DEBUG, SPP_FMT "chap TO(%s) rst_counter = %d\n",
                    SPP_ARGS(ifp),
                    sppp_state_name(sp->state[IDX_CHAP]),
                    sp->rst_counter[IDX_CHAP]);

        if (--sp->rst_counter[IDX_CHAP] < 0)
                /* TO- event */
                switch (sp->state[IDX_CHAP]) {
                case STATE_REQ_SENT:
                        chap.tld(sp);
                        sppp_cp_change_state(&chap, sp, STATE_CLOSED);
                        break;
                }
        else
                /* TO+ (or TO*) event */
                switch (sp->state[IDX_CHAP]) {
                case STATE_OPENED:
                        /* TO* event */
                        sp->rst_counter[IDX_CHAP] = sp->lcp.max_configure;
                        /* fall through */
                case STATE_REQ_SENT:
                        chap.scr(sp);
                        /* sppp_cp_change_state() will restart the timer */
                        sppp_cp_change_state(&chap, sp, STATE_REQ_SENT);
                        break;
                }

        crit_exit();
}

static void
sppp_chap_tlu(struct sppp *sp)
{
        STDDCL;
        int i;

        i = 0;
        sp->rst_counter[IDX_CHAP] = sp->lcp.max_configure;

        /*
         * Some broken CHAP implementations (Conware CoNet, firmware
         * 4.0.?) don't want to re-authenticate their CHAP once the
         * initial challenge-response exchange has taken place.
         * Provide for an option to avoid rechallenges.
         */
        if ((sp->hisauth.flags & AUTHFLAG_NORECHALLENGE) == 0) {
                /*
                 * Compute the re-challenge timeout.  This will yield
                 * a number between 300 and 810 seconds.
                 */
                i = 300 + ((unsigned)(krandom() & 0xff00) >> 7);
                callout_reset(&sp->timeout[IDX_CHAP], i * hz, chap.TO, sp);
        }

        if (debug) {
                log(LOG_DEBUG,
                    SPP_FMT "chap %s, ",
                    SPP_ARGS(ifp),
                    sp->pp_phase == PHASE_NETWORK? "reconfirmed": "tlu");
                if ((sp->hisauth.flags & AUTHFLAG_NORECHALLENGE) == 0)
                        log(-1, "next re-challenge in %d seconds\n", i);
                else
                        log(-1, "re-challenging suppressed\n");
        }

        crit_enter();

        /* indicate to LCP that we need to be closed down */
        sp->lcp.protos |= (1 << IDX_CHAP);

        if (sp->pp_flags & PP_NEEDAUTH) {
                /*
                 * Remote is authenticator, but his auth proto didn't
                 * complete yet.  Defer the transition to network
                 * phase.
                 */
                crit_exit();
                return;
        }

        crit_exit();

        /*
         * If we are already in phase network, we are done here.  This
         * is the case if this is a dummy tlu event after a re-challenge.
         */
        if (sp->pp_phase != PHASE_NETWORK)
                sppp_phase_network(sp);
}

static void
sppp_chap_tld(struct sppp *sp)
{
        STDDCL;

        if (debug)
                log(LOG_DEBUG, SPP_FMT "chap tld\n", SPP_ARGS(ifp));
        callout_stop(&sp->timeout[IDX_CHAP]);
        sp->lcp.protos &= ~(1 << IDX_CHAP);

        lcp.Close(sp);
}

static void
sppp_chap_scr(struct sppp *sp)
{
        u_long *ch, seed;
        u_char clen;

        /* Compute random challenge. */
        ch = (u_long *)sp->myauth.challenge;
        read_random(&seed, sizeof(seed), 0);
        ch[0] = seed ^ krandom();
        ch[1] = seed ^ krandom();
        ch[2] = seed ^ krandom();
        ch[3] = seed ^ krandom();
        clen = AUTHKEYLEN;

        sp->confid[IDX_CHAP] = ++sp->pp_seq[IDX_CHAP];

        sppp_auth_send(&chap, sp, CHAP_CHALLENGE, sp->confid[IDX_CHAP],
                       sizeof clen, (const char *)&clen,
                       (size_t)AUTHKEYLEN, sp->myauth.challenge,
                       (size_t)strnlen(sp->myauth.name, AUTHNAMELEN),
                       sp->myauth.name,
                       0);
}

/*
 *--------------------------------------------------------------------------*
 *                                                                          *
 *                        The PAP implementation.                           *
 *                                                                          *
 *--------------------------------------------------------------------------*
 */
/*
 * For PAP, we need to keep a little state also if we are the peer, not the
 * authenticator.  This is since we don't get a request to authenticate, but
 * have to repeatedly authenticate ourself until we got a response (or the
 * retry counter is expired).
 */

/*
 * Handle incoming PAP packets.  */
static void
sppp_pap_input(struct sppp *sp, struct mbuf *m)
{
        STDDCL;
        struct lcp_header *h;
        int len;
        u_char *name, *passwd, mlen;
        int name_len, passwd_len;

        /*
         * Malicious input might leave this uninitialized, so
         * init to an impossible value.
         */
        passwd_len = -1;

        len = m->m_pkthdr.len;
        if (len < 5) {
                if (debug)
                        log(LOG_DEBUG,
                            SPP_FMT "pap invalid packet length: %d bytes\n",
                            SPP_ARGS(ifp), len);
                return;
        }
        h = mtod (m, struct lcp_header*);
        if (len > ntohs (h->len))
                len = ntohs (h->len);
        switch (h->type) {
        /* PAP request is my authproto */
        case PAP_REQ:
                name = 1 + (u_char*)(h+1);
                name_len = name[-1];
                passwd = name + name_len + 1;
                if (name_len > len - 6 ||
                    (passwd_len = passwd[-1]) > len - 6 - name_len) {
                        if (debug) {
                                log(LOG_DEBUG, SPP_FMT "pap corrupted input "
                                    "<%s id=0x%x len=%d",
                                    SPP_ARGS(ifp),
                                    sppp_auth_type_name(PPP_PAP, h->type),
                                    h->ident, ntohs(h->len));
                                sppp_print_bytes((u_char*)(h+1), len-4);
                                log(-1, ">\n");
                        }
                        break;
                }
                if (debug) {
                        log(LOG_DEBUG, SPP_FMT "pap input(%s) "
                            "<%s id=0x%x len=%d name=",
                            SPP_ARGS(ifp),
                            sppp_state_name(sp->state[IDX_PAP]),
                            sppp_auth_type_name(PPP_PAP, h->type),
                            h->ident, ntohs(h->len));
                        sppp_print_string((char*)name, name_len);
                        log(-1, " passwd=");
                        sppp_print_string((char*)passwd, passwd_len);
                        log(-1, ">\n");
                }
                if (name_len != strnlen(sp->hisauth.name, AUTHNAMELEN) ||
                    passwd_len != strnlen(sp->hisauth.secret, AUTHKEYLEN) ||
                    bcmp(name, sp->hisauth.name, name_len) != 0 ||
                    bcmp(passwd, sp->hisauth.secret, passwd_len) != 0) {
                        /* action scn, tld */
                        mlen = sizeof(FAILMSG) - 1;
                        sppp_auth_send(&pap, sp, PAP_NAK, h->ident,
                                       sizeof mlen, (const char *)&mlen,
                                       sizeof(FAILMSG) - 1, (u_char *)FAILMSG,
                                       0);
                        pap.tld(sp);
                        break;
                }
                /* action sca, perhaps tlu */
                if (sp->state[IDX_PAP] == STATE_REQ_SENT ||
                    sp->state[IDX_PAP] == STATE_OPENED) {
                        mlen = sizeof(SUCCMSG) - 1;
                        sppp_auth_send(&pap, sp, PAP_ACK, h->ident,
                                       sizeof mlen, (const char *)&mlen,
                                       sizeof(SUCCMSG) - 1, (u_char *)SUCCMSG,
                                       0);
                }
                if (sp->state[IDX_PAP] == STATE_REQ_SENT) {
                        sppp_cp_change_state(&pap, sp, STATE_OPENED);
                        pap.tlu(sp);
                }
                break;

        /* ack and nak are his authproto */
        case PAP_ACK:
                callout_stop(&sp->pap_my_to);
                if (debug) {
                        log(LOG_DEBUG, SPP_FMT "pap success",
                            SPP_ARGS(ifp));
                        name = 1 + (u_char *)(h + 1);
                        name_len = name[-1];
                        if (len > 5 && name_len < len+4) {
                                log(-1, ": ");
                                sppp_print_string(name, name_len);
                        }
                        log(-1, "\n");
                }

                crit_enter();

                sp->pp_flags &= ~PP_NEEDAUTH;
                if (sp->myauth.proto == PPP_PAP &&
                    (sp->lcp.opts & (1 << LCP_OPT_AUTH_PROTO)) &&
                    (sp->lcp.protos & (1 << IDX_PAP)) == 0) {
                        /*
                         * We are authenticator for PAP but didn't
                         * complete yet.  Leave it to tlu to proceed
                         * to network phase.
                         */

                        crit_exit();

                        break;
                }

                crit_exit();

                sppp_phase_network(sp);
                break;

        case PAP_NAK:
                callout_stop(&sp->pap_my_to);
                if (debug) {
                        log(LOG_INFO, SPP_FMT "pap failure",
                            SPP_ARGS(ifp));
                        name = 1 + (u_char *)(h + 1);
                        name_len = name[-1];
                        if (len > 5 && name_len < len+4) {
                                log(-1, ": ");
                                sppp_print_string(name, name_len);
                        }
                        log(-1, "\n");
                } else
                        log(LOG_INFO, SPP_FMT "pap failure\n",
                            SPP_ARGS(ifp));
                /* await LCP shutdown by authenticator */
                break;

        default:
                /* Unknown PAP packet type -- ignore. */
                if (debug) {
                        log(LOG_DEBUG, SPP_FMT "pap corrupted input "
                            "<0x%x id=0x%x len=%d",
                            SPP_ARGS(ifp),
                            h->type, h->ident, ntohs(h->len));
                        sppp_print_bytes((u_char*)(h+1), len-4);
                        log(-1, ">\n");
                }
                break;

        }
}

static void
sppp_pap_init(struct sppp *sp)
{
        /* PAP doesn't have STATE_INITIAL at all. */
        sp->state[IDX_PAP] = STATE_CLOSED;
        sp->fail_counter[IDX_PAP] = 0;
        sp->pp_seq[IDX_PAP] = 0;
        sp->pp_rseq[IDX_PAP] = 0;
        callout_init(&sp->timeout[IDX_PAP]);
        callout_init(&sp->pap_my_to);
}

static void
sppp_pap_open(struct sppp *sp)
{
        if (sp->hisauth.proto == PPP_PAP &&
            (sp->lcp.opts & (1 << LCP_OPT_AUTH_PROTO)) != 0) {
                /* we are authenticator for PAP, start our timer */
                sp->rst_counter[IDX_PAP] = sp->lcp.max_configure;
                sppp_cp_change_state(&pap, sp, STATE_REQ_SENT);
        }
        if (sp->myauth.proto == PPP_PAP) {
                /* we are peer, send a request, and start a timer */
                pap.scr(sp);
                callout_reset(&sp->pap_my_to, sp->lcp.timeout,
                                sppp_pap_my_TO, sp);
        }
}

static void
sppp_pap_close(struct sppp *sp)
{
        if (sp->state[IDX_PAP] != STATE_CLOSED)
                sppp_cp_change_state(&pap, sp, STATE_CLOSED);
}

/*
 * That's the timeout routine if we are authenticator.  Since the
 * authenticator is basically passive in PAP, we can't do much here.
 */
static void
sppp_pap_TO(void *cookie)
{
        struct sppp *sp = (struct sppp *)cookie;
        STDDCL;

        crit_enter();

        if (debug)
                log(LOG_DEBUG, SPP_FMT "pap TO(%s) rst_counter = %d\n",
                    SPP_ARGS(ifp),
                    sppp_state_name(sp->state[IDX_PAP]),
                    sp->rst_counter[IDX_PAP]);

        if (--sp->rst_counter[IDX_PAP] < 0)
                /* TO- event */
                switch (sp->state[IDX_PAP]) {
                case STATE_REQ_SENT:
                        pap.tld(sp);
                        sppp_cp_change_state(&pap, sp, STATE_CLOSED);
                        break;
                }
        else
                /* TO+ event, not very much we could do */
                switch (sp->state[IDX_PAP]) {
                case STATE_REQ_SENT:
                        /* sppp_cp_change_state() will restart the timer */
                        sppp_cp_change_state(&pap, sp, STATE_REQ_SENT);
                        break;
                }

        crit_exit();
}

/*
 * That's the timeout handler if we are peer.  Since the peer is active,
 * we need to retransmit our PAP request since it is apparently lost.
 * XXX We should impose a max counter.
 */
static void
sppp_pap_my_TO(void *cookie)
{
        struct sppp *sp = (struct sppp *)cookie;
        STDDCL;

        if (debug)
                log(LOG_DEBUG, SPP_FMT "pap peer TO\n",
                    SPP_ARGS(ifp));

        pap.scr(sp);
}

static void
sppp_pap_tlu(struct sppp *sp)
{
        STDDCL;

        sp->rst_counter[IDX_PAP] = sp->lcp.max_configure;

        if (debug)
                log(LOG_DEBUG, SPP_FMT "%s tlu\n",
                    SPP_ARGS(ifp), pap.name);

        crit_enter();

        /* indicate to LCP that we need to be closed down */
        sp->lcp.protos |= (1 << IDX_PAP);

        if (sp->pp_flags & PP_NEEDAUTH) {
                /*
                 * Remote is authenticator, but his auth proto didn't
                 * complete yet.  Defer the transition to network
                 * phase.
                 */
                crit_exit();
                return;
        }
        crit_exit();
        sppp_phase_network(sp);
}

static void
sppp_pap_tld(struct sppp *sp)
{
        STDDCL;

        if (debug)
                log(LOG_DEBUG, SPP_FMT "pap tld\n", SPP_ARGS(ifp));
        callout_stop(&sp->timeout[IDX_PAP]);
        callout_stop(&sp->pap_my_to);
        sp->lcp.protos &= ~(1 << IDX_PAP);

        lcp.Close(sp);
}

static void
sppp_pap_scr(struct sppp *sp)
{
        u_char idlen, pwdlen;

        sp->confid[IDX_PAP] = ++sp->pp_seq[IDX_PAP];
        pwdlen = strnlen(sp->myauth.secret, AUTHKEYLEN);
        idlen = strnlen(sp->myauth.name, AUTHNAMELEN);

        sppp_auth_send(&pap, sp, PAP_REQ, sp->confid[IDX_PAP],
                       sizeof idlen, (const char *)&idlen,
                       (size_t)idlen, sp->myauth.name,
                       sizeof pwdlen, (const char *)&pwdlen,
                       (size_t)pwdlen, sp->myauth.secret,
                       0);
}

/*
 * Random miscellaneous functions.
 */

/*
 * Send a PAP or CHAP proto packet.
 *
 * Varadic function, each of the elements for the ellipsis is of type
 * ``size_t mlen, const u_char *msg''.  Processing will stop iff
 * mlen == 0.
 * NOTE: never declare variadic functions with types subject to type
 * promotion (i.e. u_char). This is asking for big trouble depending
 * on the architecture you are on...
 */

static void
sppp_auth_send(const struct cp *cp, struct sppp *sp,
               unsigned int type, unsigned int id,
               ...)
{
        STDDCL;
        struct ppp_header *h;
        struct lcp_header *lh;
        struct mbuf *m;
        u_char *p;
        int len;
        unsigned int mlen;
        const char *msg;
        struct ifaltq_subque *ifsq;
        __va_list ap;

        MGETHDR (m, M_NOWAIT, MT_DATA);
        if (! m)
                return;
        m->m_pkthdr.rcvif = 0;

        h = mtod (m, struct ppp_header*);
        h->address = PPP_ALLSTATIONS;           /* broadcast address */
        h->control = PPP_UI;                    /* Unnumbered Info */
        h->protocol = htons(cp->proto);

        lh = (struct lcp_header*)(h + 1);
        lh->type = type;
        lh->ident = id;
        p = (u_char*) (lh+1);

        __va_start(ap, id);
        len = 0;

        while ((mlen = (unsigned int)__va_arg(ap, size_t)) != 0) {
                msg = __va_arg(ap, const char *);
                len += mlen;
                if (len > MHLEN - PPP_HEADER_LEN - LCP_HEADER_LEN) {
                        __va_end(ap);
                        m_freem(m);
                        return;
                }

                bcopy(msg, p, mlen);
                p += mlen;
        }
        __va_end(ap);

        m->m_pkthdr.len = m->m_len = PPP_HEADER_LEN + LCP_HEADER_LEN + len;
        lh->len = htons (LCP_HEADER_LEN + len);

        if (debug) {
                log(LOG_DEBUG, SPP_FMT "%s output <%s id=0x%x len=%d",
                    SPP_ARGS(ifp), cp->name,
                    sppp_auth_type_name(cp->proto, lh->type),
                    lh->ident, ntohs(lh->len));
                sppp_print_bytes((u_char*) (lh+1), len);
                log(-1, ">\n");
        }
        if (IF_QFULL (&sp->pp_cpq)) {
                IF_DROP (&sp->pp_fastq);
                m_freem (m);
                IFNET_STAT_INC(ifp, oerrors, 1);
        } else
                IF_ENQUEUE (&sp->pp_cpq, m);
        ifsq = ifq_get_subq_default(&ifp->if_snd);
        if (!ifsq_is_oactive(ifsq))
                (*ifp->if_start) (ifp, ifsq);
        IFNET_STAT_INC(ifp, obytes, m->m_pkthdr.len + 3);
}

/*
 * Send keepalive packets, every 10 seconds.
 */
static void
sppp_keepalive(void *dummy)
{
        struct sppp *sp;

        crit_enter();

        for (sp=spppq; sp; sp=sp->pp_next) {
                struct ifnet *ifp = &sp->pp_if;

                /* Keepalive mode disabled or channel down? */
                if (! (sp->pp_flags & PP_KEEPALIVE) ||
                    ! (ifp->if_flags & IFF_RUNNING))
                        continue;

                /* No keepalive in PPP mode if LCP not opened yet. */
                if (sp->pp_mode != IFF_CISCO &&
                    sp->pp_phase < PHASE_AUTHENTICATE)
                        continue;

                if (sp->pp_alivecnt == MAXALIVECNT) {
                        /* No keepalive packets got.  Stop the interface. */
                        kprintf (SPP_FMT "down\n", SPP_ARGS(ifp));
                        if_down (ifp);
                        IF_DRAIN(&sp->pp_cpq);
                        if (sp->pp_mode != IFF_CISCO) {
                                /* XXX */
                                /* Shut down the PPP link. */
                                lcp.Down(sp);
                                /* Initiate negotiation. XXX */
                                lcp.Up(sp);
                        }
                }
                ifnet_serialize_all(ifp);
                if (sp->pp_alivecnt <= MAXALIVECNT)
                        ++sp->pp_alivecnt;
                if (sp->pp_mode == IFF_CISCO)
                        sppp_cisco_send (sp, CISCO_KEEPALIVE_REQ,
                                 ++sp->pp_seq[IDX_LCP], sp->pp_rseq[IDX_LCP]);
                else if (sp->pp_phase >= PHASE_AUTHENTICATE) {
                        long nmagic = htonl (sp->lcp.magic);
                        sp->lcp.echoid = ++sp->pp_seq[IDX_LCP];
                        sppp_cp_send (sp, PPP_LCP, ECHO_REQ,
                                sp->lcp.echoid, 4, &nmagic);
                }
                ifnet_deserialize_all(ifp);
        }
        callout_reset(&keepalive_timeout, hz * 10, sppp_keepalive, NULL);
        crit_exit();
}

/*
 * Get both IP addresses.
 */
static void
sppp_get_ip_addrs(struct sppp *sp, u_long *src, u_long *dst, u_long *srcmask)
{
        struct ifnet *ifp = &sp->pp_if;
        struct ifaddr_container *ifac;
        struct ifaddr *ifa;
        struct sockaddr_in *si, *sm;
        u_long ssrc, ddst;

        sm = NULL;
        ssrc = ddst = 0L;
        if (srcmask)
                *srcmask = 0;   /* avoid gcc warnings */
        /*
         * Pick the first AF_INET address from the list,
         * aliases don't make any sense on a p2p link anyway.
         */
        si = NULL;
        TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
                ifa = ifac->ifa;
                if (ifa->ifa_addr->sa_family == AF_INET) {
                        si = (struct sockaddr_in *)ifa->ifa_addr;
                        sm = (struct sockaddr_in *)ifa->ifa_netmask;
                        if (si)
                                break;
                }
        }
        if (ifac != NULL) {
                if (si && si->sin_addr.s_addr) {
                        ssrc = si->sin_addr.s_addr;
                        if (srcmask)
                                *srcmask = ntohl(sm->sin_addr.s_addr);
                }

                si = (struct sockaddr_in *)ifa->ifa_dstaddr;
                if (si && si->sin_addr.s_addr)
                        ddst = si->sin_addr.s_addr;
        }

        if (dst) *dst = ntohl(ddst);
        if (src) *src = ntohl(ssrc);
}

/*
 * Set my IP address.  Must be called at splimp.
 */
static void
sppp_set_ip_addr(struct sppp *sp, u_long src)
{
        STDDCL;
        struct ifaddr_container *ifac;
        struct ifaddr *ifa = NULL;
        struct sockaddr_in *si;
        struct in_ifaddr *ia;

        /*
         * Pick the first AF_INET address from the list,
         * aliases don't make any sense on a p2p link anyway.
         */
        si = NULL;
        TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
                ifa = ifac->ifa;
                if (ifa->ifa_addr->sa_family == AF_INET) {
                        si = (struct sockaddr_in *)ifa->ifa_addr;
                        if (si)
                                break;
                }
        }

        if (ifac != NULL && si != NULL) {
                int error;

                /* delete old route */
                error = rtinit(ifa, (int)RTM_DELETE, RTF_HOST);
                if(debug && error)
                {
                        log(LOG_DEBUG, SPP_FMT "sppp_set_ip_addr: rtinit DEL failed, error=%d\n",
                                SPP_ARGS(ifp), error);
                }

                ia = ifatoia(ifa);
                in_iahash_remove(ia);

                /* set new address */
                si->sin_addr.s_addr = htonl(src);
                in_iahash_insert(ia);

                /* add new route */
                error = rtinit(ifa, (int)RTM_ADD, RTF_HOST);
                if (debug && error)
                {
                        log(LOG_DEBUG, SPP_FMT "sppp_set_ip_addr: rtinit ADD failed, error=%d",
                                SPP_ARGS(ifp), error);
                }
        }
}

#ifdef INET6
/*
 * Get both IPv6 addresses.
 */
static void
sppp_get_ip6_addrs(struct sppp *sp, struct in6_addr *src, struct in6_addr *dst,
                   struct in6_addr *srcmask)
{
        struct ifnet *ifp = &sp->pp_if;
        struct ifaddr_container *ifac;
        struct ifaddr *ifa;
        struct sockaddr_in6 *si, *sm;
        struct in6_addr ssrc, ddst;

        sm = NULL;
        bzero(&ssrc, sizeof(ssrc));
        bzero(&ddst, sizeof(ddst));
        /*
         * Pick the first link-local AF_INET6 address from the list,
         * aliases don't make any sense on a p2p link anyway.
         */
        si = NULL;
        TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
                ifa = ifac->ifa;
                if (ifa->ifa_addr->sa_family == AF_INET6) {
                        si = (struct sockaddr_in6 *)ifa->ifa_addr;
                        sm = (struct sockaddr_in6 *)ifa->ifa_netmask;
                        if (si && IN6_IS_ADDR_LINKLOCAL(&si->sin6_addr))
                                break;
                }
        }
        if (ifac != NULL) {
                if (si && !IN6_IS_ADDR_UNSPECIFIED(&si->sin6_addr)) {
                        bcopy(&si->sin6_addr, &ssrc, sizeof(ssrc));
                        if (srcmask) {
                                bcopy(&sm->sin6_addr, srcmask,
                                      sizeof(*srcmask));
                        }
                }

                si = (struct sockaddr_in6 *)ifa->ifa_dstaddr;
                if (si && !IN6_IS_ADDR_UNSPECIFIED(&si->sin6_addr))
                        bcopy(&si->sin6_addr, &ddst, sizeof(ddst));
        }

        if (dst)
                bcopy(&ddst, dst, sizeof(*dst));
        if (src)
                bcopy(&ssrc, src, sizeof(*src));
}

#ifdef IPV6CP_MYIFID_DYN
/*
 * Generate random ifid.
 */
static void
sppp_gen_ip6_addr(struct sppp *sp, struct in6_addr *addr)
{
        /* TBD */
}

/*
 * Set my IPv6 address.  Must be called at splimp.
 */
static void
sppp_set_ip6_addr(struct sppp *sp, const struct in6_addr *src)
{
        STDDCL;
        struct ifaddr_container *ifac;
        struct ifaddr *ifa;
        struct sockaddr_in6 *sin6;

        /*
         * Pick the first link-local AF_INET6 address from the list,
         * aliases don't make any sense on a p2p link anyway.
         */

        sin6 = NULL;
        TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
                ifa = ifac->ifa;
                if (ifa->ifa_addr->sa_family == AF_INET6) {
                        sin6 = (struct sockaddr_in6 *)ifa->ifa_addr;
                        if (sin6 && IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr))
                                break;
                }
        }

        if (ifac != NULL && sin6 != NULL) {
                int error;
                struct sockaddr_in6 new_sin6 = *sin6;

                bcopy(src, &new_sin6.sin6_addr, sizeof(new_sin6.sin6_addr));
                error = in6_ifinit(ifp, ifatoia6(ifa), &new_sin6, 1);
                if (debug && error) {
                        log(LOG_DEBUG, SPP_FMT "sppp_set_ip6_addr: in6_ifinit "
                            " failed, error=%d\n", SPP_ARGS(ifp), error);
                }
        }
}
#endif

/*
 * Suggest a candidate address to be used by peer.
 */
static void
sppp_suggest_ip6_addr(struct sppp *sp, struct in6_addr *suggest)
{
        struct in6_addr myaddr;
        struct timeval tv;

        sppp_get_ip6_addrs(sp, &myaddr, 0, 0);

        myaddr.s6_addr[8] &= ~0x02;     /* u bit to "local" */
        microtime(&tv);
        if ((tv.tv_usec & 0xff) == 0 && (tv.tv_sec & 0xff) == 0) {
                myaddr.s6_addr[14] ^= 0xff;
                myaddr.s6_addr[15] ^= 0xff;
        } else {
                myaddr.s6_addr[14] ^= (tv.tv_usec & 0xff);
                myaddr.s6_addr[15] ^= (tv.tv_sec & 0xff);
        }
        if (suggest)
                bcopy(&myaddr, suggest, sizeof(myaddr));
}
#endif /*INET6*/

static int
sppp_params(struct sppp *sp, u_long cmd, void *data)
{
        u_long subcmd;
        struct ifreq *ifr = (struct ifreq *)data;
        struct spppreq *spr;
        int rv = 0;

        spr = kmalloc(sizeof(struct spppreq), M_TEMP, M_INTWAIT);

        /*
         * ifr->ifr_data is supposed to point to a struct spppreq.
         * Check the cmd word first before attempting to fetch all the
         * data.
         */
        if ((subcmd = fuword64(ifr->ifr_data)) == -1) {
                rv = EFAULT;
                goto quit;
        }

        if (copyin((caddr_t)ifr->ifr_data, spr, sizeof(struct spppreq)) != 0) {
                rv = EFAULT;
                goto quit;
        }

        switch (subcmd) {
        case (u_long)SPPPIOGDEFS:
                if (cmd != SIOCGIFGENERIC) {
                        rv = EINVAL;
                        break;
                }
                /*
                 * We copy over the entire current state, but clean
                 * out some of the stuff we don't wanna pass up.
                 * Remember, SIOCGIFGENERIC is unprotected, and can be
                 * called by any user.  No need to ever get PAP or
                 * CHAP secrets back to userland anyway.
                 */
                spr->defs.pp_phase = sp->pp_phase;
                spr->defs.enable_vj = (sp->confflags & CONF_ENABLE_VJ) != 0;
                spr->defs.enable_ipv6 = (sp->confflags & CONF_ENABLE_IPV6) != 0;
                spr->defs.lcp = sp->lcp;
                spr->defs.ipcp = sp->ipcp;
                spr->defs.ipv6cp = sp->ipv6cp;
                spr->defs.myauth = sp->myauth;
                spr->defs.hisauth = sp->hisauth;
                bzero(spr->defs.myauth.secret, AUTHKEYLEN);
                bzero(spr->defs.myauth.challenge, AUTHKEYLEN);
                bzero(spr->defs.hisauth.secret, AUTHKEYLEN);
                bzero(spr->defs.hisauth.challenge, AUTHKEYLEN);
                /*
                 * Fixup the LCP timeout value to milliseconds so
                 * spppcontrol doesn't need to bother about the value
                 * of "hz".  We do the reverse calculation below when
                 * setting it.
                 */
                spr->defs.lcp.timeout = sp->lcp.timeout * 1000 / hz;
                rv = copyout(spr, (caddr_t)ifr->ifr_data,
                             sizeof(struct spppreq));
                break;

        case (u_long)SPPPIOSDEFS:
                if (cmd != SIOCSIFGENERIC) {
                        rv = EINVAL;
                        break;
                }
                /*
                 * We have a very specific idea of which fields we
                 * allow being passed back from userland, so to not
                 * clobber our current state.  For one, we only allow
                 * setting anything if LCP is in dead or establish
                 * phase.  Once the authentication negotiations
                 * started, the authentication settings must not be
                 * changed again.  (The administrator can force an
                 * ifconfig down in order to get LCP back into dead
                 * phase.)
                 *
                 * Also, we only allow for authentication parameters to be
                 * specified.
                 *
                 * XXX Should allow to set or clear pp_flags.
                 *
                 * Finally, if the respective authentication protocol to
                 * be used is set differently than 0, but the secret is
                 * passed as all zeros, we don't trash the existing secret.
                 * This allows an administrator to change the system name
                 * only without clobbering the secret (which he didn't get
                 * back in a previous SPPPIOGDEFS call).  However, the
                 * secrets are cleared if the authentication protocol is
                 * reset to 0.  */
                if (sp->pp_phase != PHASE_DEAD &&
                    sp->pp_phase != PHASE_ESTABLISH) {
                        rv = EBUSY;
                        break;
                }

                if ((spr->defs.myauth.proto != 0 && spr->defs.myauth.proto != PPP_PAP &&
                     spr->defs.myauth.proto != PPP_CHAP) ||
                    (spr->defs.hisauth.proto != 0 && spr->defs.hisauth.proto != PPP_PAP &&
                     spr->defs.hisauth.proto != PPP_CHAP)) {
                        rv = EINVAL;
                        break;
                }

                if (spr->defs.myauth.proto == 0)
                        /* resetting myauth */
                        bzero(&sp->myauth, sizeof sp->myauth);
                else {
                        /* setting/changing myauth */
                        sp->myauth.proto = spr->defs.myauth.proto;
                        bcopy(spr->defs.myauth.name, sp->myauth.name, AUTHNAMELEN);
                        if (spr->defs.myauth.secret[0] != '\0')
                                bcopy(spr->defs.myauth.secret, sp->myauth.secret,
                                      AUTHKEYLEN);
                }
                if (spr->defs.hisauth.proto == 0)
                        /* resetting hisauth */
                        bzero(&sp->hisauth, sizeof sp->hisauth);
                else {
                        /* setting/changing hisauth */
                        sp->hisauth.proto = spr->defs.hisauth.proto;
                        sp->hisauth.flags = spr->defs.hisauth.flags;
                        bcopy(spr->defs.hisauth.name, sp->hisauth.name, AUTHNAMELEN);
                        if (spr->defs.hisauth.secret[0] != '\0')
                                bcopy(spr->defs.hisauth.secret, sp->hisauth.secret,
                                      AUTHKEYLEN);
                }
                /* set LCP restart timer timeout */
                if (spr->defs.lcp.timeout != 0)
                        sp->lcp.timeout = spr->defs.lcp.timeout * hz / 1000;
                /* set VJ enable and IPv6 disable flags */
#ifdef INET
                if (spr->defs.enable_vj)
                        sp->confflags |= CONF_ENABLE_VJ;
                else
                        sp->confflags &= ~CONF_ENABLE_VJ;
#endif
#ifdef INET6
                if (spr->defs.enable_ipv6)
                        sp->confflags |= CONF_ENABLE_IPV6;
                else
                        sp->confflags &= ~CONF_ENABLE_IPV6;
#endif
                break;

        default:
                rv = EINVAL;
        }

 quit:
        kfree(spr, M_TEMP);

        return (rv);
}

static void
sppp_phase_network(struct sppp *sp)
{
        STDDCL;
        int i;
        u_long mask;

        sp->pp_phase = PHASE_NETWORK;

        if (debug)
                log(LOG_DEBUG, SPP_FMT "phase %s\n", SPP_ARGS(ifp),
                    sppp_phase_name(sp->pp_phase));

        /* Notify NCPs now. */
        for (i = 0; i < IDX_COUNT; i++)
                if ((cps[i])->flags & CP_NCP)
                        (cps[i])->Open(sp);

        /* Send Up events to all NCPs. */
        for (i = 0, mask = 1; i < IDX_COUNT; i++, mask <<= 1)
                if ((sp->lcp.protos & mask) && ((cps[i])->flags & CP_NCP))
                        (cps[i])->Up(sp);

        /* if no NCP is starting, all this was in vain, close down */
        sppp_lcp_check_and_close(sp);
}


static const char *
sppp_cp_type_name(u_char type)
{
        static char buf[12];
        switch (type) {
        case CONF_REQ:   return "conf-req";
        case CONF_ACK:   return "conf-ack";
        case CONF_NAK:   return "conf-nak";
        case CONF_REJ:   return "conf-rej";
        case TERM_REQ:   return "term-req";
        case TERM_ACK:   return "term-ack";
        case CODE_REJ:   return "code-rej";
        case PROTO_REJ:  return "proto-rej";
        case ECHO_REQ:   return "echo-req";
        case ECHO_REPLY: return "echo-reply";
        case DISC_REQ:   return "discard-req";
        }
        ksnprintf (buf, sizeof(buf), "cp/0x%x", type);
        return buf;
}

static const char *
sppp_auth_type_name(u_short proto, u_char type)
{
        static char buf[12];
        switch (proto) {
        case PPP_CHAP:
                switch (type) {
                case CHAP_CHALLENGE:    return "challenge";
                case CHAP_RESPONSE:     return "response";
                case CHAP_SUCCESS:      return "success";
                case CHAP_FAILURE:      return "failure";
                }
        case PPP_PAP:
                switch (type) {
                case PAP_REQ:           return "req";
                case PAP_ACK:           return "ack";
                case PAP_NAK:           return "nak";
                }
        }
        ksnprintf (buf, sizeof(buf), "auth/0x%x", type);
        return buf;
}

static const char *
sppp_lcp_opt_name(u_char opt)
{
        static char buf[12];
        switch (opt) {
        case LCP_OPT_MRU:               return "mru";
        case LCP_OPT_ASYNC_MAP:         return "async-map";
        case LCP_OPT_AUTH_PROTO:        return "auth-proto";
        case LCP_OPT_QUAL_PROTO:        return "qual-proto";
        case LCP_OPT_MAGIC:             return "magic";
        case LCP_OPT_PROTO_COMP:        return "proto-comp";
        case LCP_OPT_ADDR_COMP:         return "addr-comp";
        }
        ksnprintf (buf, sizeof(buf), "lcp/0x%x", opt);
        return buf;
}

static const char *
sppp_ipcp_opt_name(u_char opt)
{
        static char buf[12];
        switch (opt) {
        case IPCP_OPT_ADDRESSES:        return "addresses";
        case IPCP_OPT_COMPRESSION:      return "compression";
        case IPCP_OPT_ADDRESS:          return "address";
        }
        ksnprintf (buf, sizeof(buf), "ipcp/0x%x", opt);
        return buf;
}

#ifdef INET6
static const char *
sppp_ipv6cp_opt_name(u_char opt)
{
        static char buf[12];
        switch (opt) {
        case IPV6CP_OPT_IFID:           return "ifid";
        case IPV6CP_OPT_COMPRESSION:    return "compression";
        }
        ksprintf (buf, "0x%x", opt);
        return buf;
}
#endif

static const char *
sppp_state_name(int state)
{
        switch (state) {
        case STATE_INITIAL:     return "initial";
        case STATE_STARTING:    return "starting";
        case STATE_CLOSED:      return "closed";
        case STATE_STOPPED:     return "stopped";
        case STATE_CLOSING:     return "closing";
        case STATE_STOPPING:    return "stopping";
        case STATE_REQ_SENT:    return "req-sent";
        case STATE_ACK_RCVD:    return "ack-rcvd";
        case STATE_ACK_SENT:    return "ack-sent";
        case STATE_OPENED:      return "opened";
        }
        return "illegal";
}

static const char *
sppp_phase_name(enum ppp_phase phase)
{
        switch (phase) {
        case PHASE_DEAD:        return "dead";
        case PHASE_ESTABLISH:   return "establish";
        case PHASE_TERMINATE:   return "terminate";
        case PHASE_AUTHENTICATE: return "authenticate";
        case PHASE_NETWORK:     return "network";
        }
        return "illegal";
}

static const char *
sppp_proto_name(u_short proto)
{
        static char buf[12];
        switch (proto) {
        case PPP_LCP:   return "lcp";
        case PPP_IPCP:  return "ipcp";
        case PPP_PAP:   return "pap";
        case PPP_CHAP:  return "chap";
        case PPP_IPV6CP: return "ipv6cp";
        }
        ksnprintf(buf, sizeof(buf), "proto/0x%x", (unsigned)proto);
        return buf;
}

static void
sppp_print_bytes(const u_char *p, u_short len)
{
        char hexstr[len];
        if (len)
                log(-1, " %s", hexncpy(p, len, hexstr, HEX_NCPYLEN(len), "-"));
}

static void
sppp_print_string(const char *p, u_short len)
{
        u_char c;

        while (len-- > 0) {
                c = *p++;
                /*
                 * Print only ASCII chars directly.  RFC 1994 recommends
                 * using only them, but we don't rely on it.  */
                if (c < ' ' || c > '~')
                        log(-1, "\\x%x", c);
                else
                        log(-1, "%c", c);
        }
}

static const char *
sppp_dotted_quad(u_long addr)
{
        static char s[16];
        ksprintf(s, "%d.%d.%d.%d",
                (int)((addr >> 24) & 0xff),
                (int)((addr >> 16) & 0xff),
                (int)((addr >> 8) & 0xff),
                (int)(addr & 0xff));
        return s;
}

/* a dummy, used to drop uninteresting events */
static void
sppp_null(struct sppp *unused)
{
        /* do just nothing */
}
DragonflyBSD
