/*      $OpenBSD: if_spppsubr.c,v 1.200 2025/11/02 08:33:43 dlg Exp $   */
/*
 * Synchronous PPP link level subroutines.
 *
 * Copyright (C) 1994-1996 Cronyx Engineering Ltd.
 * Author: Serge Vakulenko, <vak@cronyx.ru>
 *
 * Heavily revamped to conform to RFC 1661.
 * Copyright (C) 1997, Joerg Wunsch.
 *
 * RFC2472 IPv6CP support.
 * Copyright (C) 2000, Jun-ichiro itojun Hagino <itojun@iijlab.net>.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE FREEBSD PROJECT ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE FREEBSD PROJECT OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 * From: Version 2.6, Tue May 12 17:10:39 MSD 1998
 */

#include <sys/param.h>

#include <sys/systm.h>
#include <sys/sockio.h>
#include <sys/socket.h>
#include <sys/syslog.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>

#include <sys/timeout.h>
#include <crypto/md5.h>

#include <net/if.h>
#include <net/if_var.h>
#include <net/if_types.h>
#include <net/route.h>

#include <sys/stdarg.h>

#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>

#ifdef INET6
#include <netinet6/in6_ifattach.h>
#endif

#include <net/if_sppp.h>

extern unsigned int     rtmap_limit;

# define UNTIMEOUT(fun, arg, handle)    \
        timeout_del(&(handle))

#define MAXALIVECNT                     3       /* max. missed alive packets */
#define NORECV_TIME                     15      /* before we get worried */

/*
 * 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", "chap", "pap", etc.
 */

#define IFF_PASSIVE     IFF_LINK0       /* wait passively for connection */
#define IFF_AUTO        IFF_LINK1       /* 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_IPX         0x002b          /* Novell IPX Protocol */
#define PPP_IPV6        0x0057          /* Internet Protocol v6 */
#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 IPCP_OPT_PRIMDNS        129     /* primary remote dns address */
#define IPCP_OPT_SECDNS         131     /* secondary remote dns address */

/* bitmask value to enable or disable individual IPCP options */
#define SPPP_IPCP_OPT_ADDRESSES         1
#define SPPP_IPCP_OPT_COMPRESSION       2
#define SPPP_IPCP_OPT_ADDRESS           3
#define SPPP_IPCP_OPT_PRIMDNS           4
#define SPPP_IPCP_OPT_SECDNS            5

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

#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 */

/* 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

#define PKTHDRLEN       2

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

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

/*
 * 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 timeout keepalive_ch;

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

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

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

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

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

void sppp_null(struct sppp *sp);

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

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

void sppp_ipv6cp_init(struct sppp *sp);
void sppp_ipv6cp_destroy(struct sppp *sp);
void sppp_ipv6cp_up(struct sppp *sp);
void sppp_ipv6cp_down(struct sppp *sp);
void sppp_ipv6cp_open(struct sppp *sp);
void sppp_ipv6cp_close(struct sppp *sp);
void sppp_ipv6cp_TO(void *sp);
int sppp_ipv6cp_RCR(struct sppp *sp, struct lcp_header *h, int len);
void sppp_ipv6cp_RCN_rej(struct sppp *sp, struct lcp_header *h, int len);
void sppp_ipv6cp_RCN_nak(struct sppp *sp, struct lcp_header *h, int len);
void sppp_ipv6cp_tlu(struct sppp *sp);
void sppp_ipv6cp_tld(struct sppp *sp);
void sppp_ipv6cp_tls(struct sppp *sp);
void sppp_ipv6cp_tlf(struct sppp *sp);
void sppp_ipv6cp_scr(struct sppp *sp);
const char *sppp_ipv6cp_opt_name(u_char opt);
void sppp_get_ip6_addrs(struct sppp *sp, struct in6_addr *src,
                               struct in6_addr *dst, struct in6_addr *srcmask);
void sppp_set_ip6_addr(struct sppp *sp, const struct in6_addr *src, const struct in6_addr *dst);
void sppp_update_ip6_addr(void *sp);
void sppp_suggest_ip6_addr(struct sppp *sp, struct in6_addr *suggest);

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

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

const char *sppp_auth_type_name(u_short proto, u_char type);
const char *sppp_cp_type_name(u_char type);
const char *sppp_dotted_quad(u_int32_t addr);
const char *sppp_ipcp_opt_name(u_char opt);
const char *sppp_lcp_opt_name(u_char opt);
const char *sppp_phase_name(enum ppp_phase phase);
const char *sppp_proto_name(u_short proto);
const char *sppp_state_name(int state);
int sppp_get_params(struct sppp *sp, struct ifreq *data);
int sppp_set_params(struct sppp *sp, struct ifreq *data);
void sppp_get_ip_addrs(struct sppp *sp, u_int32_t *src, u_int32_t *dst,
                              u_int32_t *srcmask);
void sppp_keepalive(void *dummy);
void sppp_phase_network(struct sppp *sp);
void sppp_print_bytes(const u_char *p, u_short len);
void sppp_print_string(const char *p, u_short len);
int sppp_update_gw_walker(struct rtentry *rt, void *arg, unsigned int id);
void sppp_update_gw(struct ifnet *ifp);
void sppp_set_ip_addrs(void *);
void sppp_clear_ip_addrs(void *);
void sppp_set_phase(struct sppp *sp);
void sppp_update_dns(struct ifnet *ifp);
void sppp_rtrequest(struct ifnet *ifp, int req, struct rtentry *rt);

/* 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 */
};


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

/* Workaround */
void
spppattach(struct ifnet *ifp)
{
}

int
sppp_proto_up(struct ifnet *ifp, uint16_t proto)
{
        struct sppp *sp = (struct sppp *)ifp;
        int af = AF_UNSPEC;

        switch (ntohs(proto)) {
        case PPP_IP:
                if (sp->state[IDX_IPCP] == STATE_OPENED)
                        af = AF_INET;
                break;
#ifdef INET6
        case PPP_IPV6:
                if (sp->state[IDX_IPV6CP] == STATE_OPENED)
                        af = AF_INET6;
                break;
#endif
        default:
                break;
        }

        return (af);
}

/*
 * Process the received packet.
 */
void
sppp_input(struct ifnet *ifp, struct mbuf *m)
{
        struct ppp_header ht;
        struct sppp *sp = (struct sppp *)ifp;
        struct timeval tv;
        int debug = ifp->if_flags & IFF_DEBUG;

        getmicrouptime(&tv);

        if (ifp->if_flags & IFF_UP) {
                /* Count received bytes, add hardware framing */
                ifp->if_ibytes += m->m_pkthdr.len + sp->pp_framebytes;
                /* Note time of last receive */
                sp->pp_last_receive = tv.tv_sec;
        }

        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);
                ++ifp->if_ierrors;
                ++ifp->if_iqdrops;
                return;
        }

        /* mark incoming routing domain */
        m->m_pkthdr.ph_rtableid = ifp->if_rdomain;

        m_copydata(m, 0, sizeof(ht.protocol), (caddr_t)&ht.protocol);
        m_adj(m, 2);
        ht.control = PPP_UI;
        ht.address = PPP_ALLSTATIONS;

        /* preserve the alignment */
        if (m->m_len < m->m_pkthdr.len) {
                m = m_pullup(m, m->m_pkthdr.len);
                if (m == NULL) {
                        if (debug)
                                log(LOG_DEBUG,
                                    SPP_FMT "Failed to align packet!\n", SPP_ARGS(ifp));
                        ++ifp->if_ierrors;
                        ++ifp->if_iqdrops;
                        return;
                }
        }

        switch (ht.address) {
        case PPP_ALLSTATIONS:
                if (ht.control != PPP_UI)
                        goto invalid;
                switch (ntohs (ht.protocol)) {
                default:
                        if (sp->state[IDX_LCP] == STATE_OPENED)
                                sppp_cp_send (sp, PPP_LCP, PROTO_REJ,
                                    ++sp->pp_seq, 2, &ht.protocol);
                        if (debug)
                                log(LOG_DEBUG,
                                    SPP_FMT "invalid input protocol "
                                    "<addr=0x%x ctrl=0x%x proto=0x%x>\n",
                                    SPP_ARGS(ifp),
                                    ht.address, ht.control, ntohs(ht.protocol));
                        ++ifp->if_noproto;
                        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;
                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) {
                                sp->pp_last_activity = tv.tv_sec;
                                if (ifp->if_flags & IFF_UP) {
                                        ipv4_input(ifp, m, NULL);
                                        return;
                                }
                        }
                        break;
#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) {
                                sp->pp_last_activity = tv.tv_sec;
                                if (ifp->if_flags & IFF_UP) {
                                        ipv6_input(ifp, m, NULL);
                                        return;
                                }
                        }
                        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),
                            ht.address, ht.control, ntohs(ht.protocol));
                goto drop;
        }

        goto drop;
}

void
sppp_autodial(void *arg)
{
        struct sppp *sp = arg;
        struct ifnet *ifp = &sp->pp_if;

        NET_LOCK();
        if ((ifp->if_flags & (IFF_RUNNING | IFF_AUTO)) == IFF_AUTO) {
                ifp->if_flags |= IFF_RUNNING;
                lcp.Open(sp);
        }
        NET_UNLOCK();
}

/*
 * Enqueue transmit packet.
 */
int
sppp_output(struct ifnet *ifp, struct mbuf *m,
            struct sockaddr *dst, struct rtentry *rt)
{
        struct sppp *sp = (struct sppp*) ifp;
        struct timeval tv;
        int s, rv = 0;
        u_int16_t protocol;
        int if_flags;

#ifdef DIAGNOSTIC
        if (ifp->if_rdomain != rtable_l2(m->m_pkthdr.ph_rtableid)) {
                printf("%s: trying to send packet on wrong domain. "
                    "if %d vs. mbuf %d, AF %d\n", ifp->if_xname,
                    ifp->if_rdomain, rtable_l2(m->m_pkthdr.ph_rtableid),
                    dst->sa_family);
        }
#endif

        s = splnet();

        getmicrouptime(&tv);
        sp->pp_last_activity = tv.tv_sec;

        if_flags = ifp->if_flags;
        if ((if_flags & IFF_UP) == 0 ||
            (if_flags & (IFF_RUNNING | IFF_AUTO)) == 0) {
                m_freem (m);
                splx (s);
                return (ENETDOWN);
        }

        if ((if_flags & (IFF_RUNNING | IFF_AUTO)) == IFF_AUTO) {
                /*
                 * Interface is not yet running, but auto-dial.  Need
                 * to start LCP for it.
                 */
                task_add(systq, &sp->pp_autodial);
        }

        if (dst->sa_family == AF_INET) {
                struct ip *ip = NULL;

                if (m->m_len >= sizeof(struct ip))
                        ip = mtod(m, struct ip *);

                /*
                 * 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->ip_src.s_addr == INADDR_ANY) {
                        u_int8_t proto = ip->ip_p;

                        m_freem(m);
                        splx(s);
                        if (proto == IPPROTO_TCP)
                                return (EADDRNOTAVAIL);
                        else
                                return (0);
                }
        }

        switch (dst->sa_family) {
        case AF_INET:   /* Internet Protocol */
                /*
                 * 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.
                 */
                protocol = htons(PPP_IP);
                if (sp->state[IDX_IPCP] != STATE_OPENED) {
                        rv = ENETDOWN;
                }
                break;
#ifdef INET6
        case AF_INET6:   /* Internet Protocol v6 */
                /*
                 * 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 IPv6 packets, and return
                 * ENETDOWN, as opposed to ENOBUFS.
                 */
                protocol = htons(PPP_IPV6);
                if (sp->state[IDX_IPV6CP] != STATE_OPENED)
                        rv = ENETDOWN;
                break;
#endif
        default:
                m_freem(m);
                ++ifp->if_oerrors;
                splx(s);
                return (EAFNOSUPPORT);
        }

        m->m_pkthdr.ph_family = dst->sa_family; /* for bpf */

        M_PREPEND(m, 2, M_DONTWAIT);
        if (m == NULL) {
                if (ifp->if_flags & IFF_DEBUG)
                        log(LOG_DEBUG, SPP_FMT
                            "no memory for transmit header\n",
                            SPP_ARGS(ifp));
                ++ifp->if_oerrors;
                splx(s);
                return (rv ? rv : ENOBUFS);
        }
        *mtod(m, u_int16_t *) = protocol;

        /*
         * Queue message on interface, and start output if interface
         * not yet active.
         */
        rv = if_enqueue(ifp, m);
        if (rv != 0) {
                ifp->if_oerrors++;
                splx(s);
                return (rv);
        }

        /*
         * Count output packets and bytes.
         * The packet length includes header, FCS and 1 flag,
         * according to RFC 1333.
         */
        ifp->if_obytes += sp->pp_framebytes;
        splx(s);

        return (0);
}

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

        /* Initialize keepalive handler. */
        if (! spppq) {
                timeout_set_proc(&keepalive_ch, sppp_keepalive, NULL);
                timeout_add_sec(&keepalive_ch, 10);
        }

        /* Insert new entry into the keepalive list. */
        sp->pp_next = spppq;
        spppq = sp;

        sp->pp_if.if_type = IFT_PPP;
        sp->pp_if.if_output = sppp_output;
        sp->pp_if.if_rtrequest = sppp_rtrequest;
        ifq_init_maxlen(&sp->pp_if.if_snd, 50);
        mq_init(&sp->pp_cpq, 50, IPL_NET);
        sp->pp_loopcnt = 0;
        sp->pp_alivecnt = 0;
        sp->pp_last_activity = 0;
        sp->pp_last_receive = 0;
        sp->pp_seq = 0;
        sp->pp_rseq = 0;
        sp->pp_phase = PHASE_DEAD;
        sp->pp_up = lcp.Up;
        sp->pp_down = lcp.Down;

        task_set(&sp->pp_autodial, sppp_autodial, sp);

        for (i = 0; i < IDX_COUNT; i++)
                timeout_set(&sp->ch[i], (cps[i])->TO, (void *)sp);
        timeout_set(&sp->pap_my_to_ch, sppp_pap_my_TO, (void *)sp);

        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;

        taskq_del_barrier(systq, &sp->pp_autodial);

        sppp_ipcp_destroy(sp);
        sppp_ipv6cp_destroy(sp);

        /* 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)
                UNTIMEOUT(sppp_keepalive, 0, keepalive_ch);

        for (i = 0; i < IDX_COUNT; i++)
                UNTIMEOUT((cps[i])->TO, (void *)sp, sp->ch[i]);
        UNTIMEOUT(sppp_pap_my_TO, (void *)sp, sp->pap_my_to_ch);

        /* release authentication data */
        if (sp->myauth.name != NULL)
                free(sp->myauth.name, M_DEVBUF, strlen(sp->myauth.name) + 1);
        if (sp->myauth.secret != NULL)
                free(sp->myauth.secret, M_DEVBUF,
                    strlen(sp->myauth.secret) + 1);
        if (sp->hisauth.name != NULL)
                free(sp->hisauth.name, M_DEVBUF, strlen(sp->hisauth.name) + 1);
        if (sp->hisauth.secret != NULL)
                free(sp->hisauth.secret, M_DEVBUF,
                    strlen(sp->hisauth.secret) + 1);
}

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

        ifq_purge(&sp->pp_if.if_snd);
        mq_purge(&sp->pp_cpq);
}

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

        s = splnet();
        empty = mq_empty(&sp->pp_cpq) && ifq_empty(&sp->pp_if.if_snd);
        splx(s);
        return (empty);
}

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

        s = splnet();
        /*
         * Process only the control protocol queue until we have at
         * least one NCP open.
         */
        m = mq_dequeue(&sp->pp_cpq);
        if (m == NULL && sppp_ncp_check(sp)) {
                m = ifq_dequeue(&sp->pp_if.if_snd);
        }
        splx(s);
        return m;
}

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

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

        case SIOCSIFADDR:
                if_up(ifp);
                /* FALLTHROUGH */

        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_AUTO | IFF_PASSIVE);
                if (newmode == (IFF_AUTO | IFF_PASSIVE)) {
                        /* sanity */
                        newmode = IFF_PASSIVE;
                        ifp->if_flags &= ~IFF_AUTO;
                }

                if (going_up || going_down)
                        lcp.Close(sp);

                if (going_up && newmode == 0) {
                        /* neither auto-dial nor passive */
                        ifp->if_flags |= IFF_RUNNING;
                        lcp.Open(sp);
                } else if (going_down) {
                        sppp_flush(ifp);
                        ifp->if_flags &= ~IFF_RUNNING;
                }
                break;

        case SIOCSIFMTU:
                if (ifr->ifr_mtu < 128 ||
                    (sp->lcp.their_mru > 0 &&
                     ifr->ifr_mtu > sp->lcp.their_mru)) {
                        splx(s);
                        return (EINVAL);
                }
                ifp->if_mtu = ifr->ifr_mtu;
                break;
        case SIOCADDMULTI:
        case SIOCDELMULTI:
                break;

        case SIOCGSPPPPARAMS:
                rv = sppp_get_params(sp, ifr);
                break;

        case SIOCSSPPPPARAMS:
                if ((rv = suser(curproc)) != 0)
                        break;
                rv = sppp_set_params(sp, ifr);
                break;

        default:
                rv = ENOTTY;
        }
        splx(s);
        return rv;
}

/*
 * PPP protocol implementation.
 */

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

        if (len > MHLEN - PKTHDRLEN - LCP_HEADER_LEN)
                len = MHLEN - PKTHDRLEN - LCP_HEADER_LEN;
        MGETHDR (m, M_DONTWAIT, MT_DATA);
        if (! m)
                return;
        m->m_pkthdr.len = m->m_len = PKTHDRLEN + LCP_HEADER_LEN + len;
        m->m_pkthdr.ph_ifidx = 0;
        m->m_pkthdr.pf.prio = sp->pp_if.if_llprio;

        *mtod(m, u_int16_t *) = htons(proto);
        lh = (struct lcp_header *)(mtod(m, u_int8_t *) + 2);
        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));
                if (len)
                        sppp_print_bytes ((u_char*) (lh+1), len);
                addlog(">\n");
        }

        len = m->m_pkthdr.len + sp->pp_framebytes;
        if (mq_enqueue(&sp->pp_cpq, m) != 0) {
                ifp->if_oerrors++;
                return;
        }

        ifp->if_obytes += len;
        s = splnet();
        if_start(ifp);
        splx(s);
}

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

        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) {
                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, ntohs (h->len));
                if (len > 4)
                        sppp_print_bytes ((u_char*) (h+1), len-4);
                addlog(">\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)
                                addlog(SPP_FMT "%s invalid conf-req length %d\n",
                                       SPP_ARGS(ifp), cp->name,
                                       len);
                        ++ifp->if_ierrors;
                        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);
                /* silently drop illegal packets */
                if (rv == -1)
                        return;
                switch (sp->state[cp->protoidx]) {
                case STATE_OPENED:
                        sppp_cp_change_state(cp, sp, rv?
                                             STATE_ACK_SENT: STATE_REQ_SENT);
                        (cp->tld)(sp);
                        (cp->scr)(sp);
                        break;
                case STATE_ACK_SENT:
                case STATE_REQ_SENT:
                        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;
                        sppp_cp_change_state(cp, sp, rv?
                                             STATE_ACK_SENT: STATE_REQ_SENT);
                        (cp->scr)(sp);
                        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:
                        /* printf(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])); */
                        ++ifp->if_ierrors;
                }
                break;
        case CONF_ACK:
                if (h->ident != sp->confid[cp->protoidx]) {
                        if (debug)
                                addlog(SPP_FMT "%s id mismatch 0x%x != 0x%x\n",
                                       SPP_ARGS(ifp), cp->name,
                                       h->ident, sp->confid[cp->protoidx]);
                        ++ifp->if_ierrors;
                        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:
                        sppp_cp_change_state(cp, sp, STATE_REQ_SENT);
                        (cp->tld)(sp);
                        (cp->scr)(sp);
                        break;
                case STATE_ACK_RCVD:
                        sppp_cp_change_state(cp, sp, STATE_REQ_SENT);
                        (cp->scr)(sp);
                        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:
                        /* printf(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])); */
                        ++ifp->if_ierrors;
                }
                break;
        case CONF_NAK:
        case CONF_REJ:
                if (h->ident != sp->confid[cp->protoidx]) {
                        if (debug)
                                addlog(SPP_FMT "%s id mismatch 0x%x != 0x%x\n",
                                       SPP_ARGS(ifp), cp->name,
                                       h->ident, sp->confid[cp->protoidx]);
                        ++ifp->if_ierrors;
                        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;
                        (cp->scr)(sp);
                        break;
                case STATE_OPENED:
                        sppp_cp_change_state(cp, sp, STATE_ACK_SENT);
                        (cp->tld)(sp);
                        (cp->scr)(sp);
                        break;
                case STATE_ACK_RCVD:
                        sppp_cp_change_state(cp, sp, STATE_ACK_SENT);
                        (cp->scr)(sp);
                        break;
                case STATE_CLOSING:
                case STATE_STOPPING:
                        break;
                default:
                        /* printf(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])); */
                        ++ifp->if_ierrors;
                }
                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);
                        /* FALLTHROUGH */
                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:
                        sp->rst_counter[cp->protoidx] = 0;
                        sppp_cp_change_state(cp, sp, STATE_STOPPING);
                        (cp->tld)(sp);
                        goto sta;
                        break;
                default:
                        /* printf(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])); */
                        ++ifp->if_ierrors;
                }
                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:
                        sppp_cp_change_state(cp, sp, STATE_ACK_RCVD);
                        (cp->tld)(sp);
                        (cp->scr)(sp);
                        break;
                default:
                        /* printf(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])); */
                        ++ifp->if_ierrors;
                }
                break;
        case CODE_REJ:
        case PROTO_REJ:
            {
                int catastrophic = 0;
                const struct cp *upper = NULL;
                int i;
                u_int16_t proto;

                if (len < 2) {
                        if (debug)
                                log(LOG_DEBUG, SPP_FMT "invalid proto-rej length\n",
                                       SPP_ARGS(ifp));
                        ++ifp->if_ierrors;
                        break;
                }

                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) {
                        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:
                        /* printf(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])); */
                        ++ifp->if_ierrors;
                }
                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)
                                addlog(SPP_FMT "lcp echo req but lcp closed\n",
                                       SPP_ARGS(ifp));
                        ++ifp->if_ierrors;
                        break;
                }
                if (len < 8) {
                        if (debug)
                                addlog(SPP_FMT "invalid lcp echo request "
                                       "packet length: %d bytes\n",
                                       SPP_ARGS(ifp), len);
                        break;
                }

                nmagic = (u_long)p[0] << 24 |
                    (u_long)p[1] << 16 | p[2] << 8 | p[3];

                if (nmagic == sp->lcp.magic) {
                        /* Line loopback mode detected. */
                        log(LOG_INFO, SPP_FMT "loopback\n", SPP_ARGS(ifp));
                        /* Shut down the PPP link. */
                        lcp.Close(sp);
                        break;
                }

                p[0] = sp->lcp.magic >> 24;
                p[1] = sp->lcp.magic >> 16;
                p[2] = sp->lcp.magic >> 8;
                p[3] = sp->lcp.magic;

                if (debug)
                        addlog(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) {
                        ++ifp->if_ierrors;
                        break;
                }
                if (len < 8) {
                        if (debug)
                                addlog(SPP_FMT "lcp invalid echo reply "
                                       "packet length: %d bytes\n",
                                       SPP_ARGS(ifp), len);
                        break;
                }
                if (debug)
                        addlog(SPP_FMT "lcp got echo rep\n",
                               SPP_ARGS(ifp));

                nmagic = (u_long)p[0] << 24 |
                    (u_long)p[1] << 16 | p[2] << 8 | p[3];

                if (nmagic != sp->lcp.magic)
                        sp->pp_alivecnt = 0;
                break;
        default:
                /* Unknown packet type -- send Code-Reject packet. */
          illegal:
                if (debug)
                        addlog(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,
                             m->m_pkthdr.len, h);
                ++ifp->if_ierrors;
        }
}


/*
 * The generic part of all Up/Down/Open/Close/TO event handlers.
 * Basically, the state transition handling in the automaton.
 */
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;
                sppp_cp_change_state(cp, sp, STATE_REQ_SENT);
                (cp->scr)(sp);
                break;
        default:
                /* printf(SPP_FMT "%s illegal up in state %s\n",
                       SPP_ARGS(ifp), cp->name,
                       sppp_state_name(sp->state[cp->protoidx])); */
                break;
        }
}

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:
                sppp_cp_change_state(cp, sp, STATE_STARTING);
                (cp->tld)(sp);
                break;
        default:
                /* printf(SPP_FMT "%s illegal down in state %s\n",
                       SPP_ARGS(ifp), cp->name,
                       sppp_state_name(sp->state[cp->protoidx])); */
                break;
        }
}


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;
                sppp_cp_change_state(cp, sp, STATE_REQ_SENT);
                (cp->scr)(sp);
                break;
        case STATE_STOPPED:
        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;
        }
}


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:
                sppp_cp_change_state(cp, sp, STATE_CLOSING);
                sp->rst_counter[cp->protoidx] = sp->lcp.max_terminate;
                sppp_cp_send(sp, cp->proto, TERM_REQ, ++sp->pp_seq, 0, 0);
                (cp->tld)(sp);
                break;
        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, 0, 0);
                sppp_cp_change_state(cp, sp, STATE_CLOSING);
                break;
        }
}

void
sppp_increasing_timeout(const struct cp *cp, struct sppp *sp)
{
        int timo;

        timo = sp->lcp.max_configure - sp->rst_counter[cp->protoidx];
        if (timo < 1)
                timo = 1;
        timeout_add_sec(&sp->ch[cp->protoidx], timo * sp->lcp.timeout);
}

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

        s = splnet();
        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,
                                     0, 0);
                        sppp_increasing_timeout (cp, sp);
                        break;
                case STATE_REQ_SENT:
                case STATE_ACK_RCVD:
                        /* sppp_cp_change_state() will restart the timer */
                        sppp_cp_change_state(cp, sp, STATE_REQ_SENT);
                        (cp->scr)(sp);
                        break;
                case STATE_ACK_SENT:
                        sppp_increasing_timeout (cp, sp);
                        (cp->scr)(sp);
                        break;
                }

        splx(s);
}

/*
 * Change the state of a control protocol in the state automaton.
 * Takes care of starting/stopping the restart timer.
 */
void
sppp_cp_change_state(const struct cp *cp, struct sppp *sp, int newstate)
{
        STDDCL;

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

        switch (newstate) {
        case STATE_INITIAL:
        case STATE_STARTING:
        case STATE_CLOSED:
        case STATE_STOPPED:
        case STATE_OPENED:
                UNTIMEOUT(cp->TO, (void *)sp, sp->ch[cp->protoidx]);
                break;
        case STATE_CLOSING:
        case STATE_STOPPING:
        case STATE_REQ_SENT:
        case STATE_ACK_RCVD:
        case STATE_ACK_SENT:
                if (!timeout_pending(&sp->ch[cp->protoidx]))
                        sppp_increasing_timeout (cp, sp);
                break;
        }
}
/*
 *--------------------------------------------------------------------------*
 *                                                                          *
 *                         The LCP implementation.                          *
 *                                                                          *
 *--------------------------------------------------------------------------*
 */
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->lcp.protos = 0;
        sp->lcp.mru = sp->pp_if.if_mtu;
        sp->lcp.their_mru = 0;

        /*
         * Initialize counters and timeout values.  Note that we don't
         * use the 3 seconds suggested in RFC 1661 since we are likely
         * running on a fast link.  XXX We should probably implement
         * the exponential backoff option.  Note that these values are
         * relevant for all control protocols, not just LCP only.
         */
        sp->lcp.timeout = 1;    /* seconds */
        sp->lcp.max_terminate = 2;
        sp->lcp.max_configure = 10;
        sp->lcp.max_failure = 10;
}

void
sppp_lcp_up(struct sppp *sp)
{
        STDDCL;
        struct timeval tv;

        sp->pp_alivecnt = 0;
        sp->lcp.opts = (1 << LCP_OPT_MAGIC);
        sp->lcp.magic = 0;
        sp->lcp.protos = 0;
        if (sp->pp_if.if_mtu != PP_MTU) {
                sp->lcp.mru = sp->pp_if.if_mtu;
                sp->lcp.opts |= (1 << LCP_OPT_MRU);
        } else
                sp->lcp.mru = PP_MTU;
        sp->lcp.their_mru = PP_MTU;

        getmicrouptime(&tv);
        sp->pp_last_receive = sp->pp_last_activity = tv.tv_sec;

        /*
         * 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)
                                addlog("(incoming call)\n");
                        sp->pp_flags |= PP_CALLIN;
                        lcp.Open(sp);
                } else if (debug)
                        addlog("\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);
}

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) {
                if (debug)
                        log(LOG_DEBUG, SPP_FMT "Down event (carrier loss), "
                            "taking interface down.", SPP_ARGS(ifp));
                if_down(ifp);
        } else {
                if (debug)
                        log(LOG_DEBUG, SPP_FMT "Down event (carrier loss)\n",
                            SPP_ARGS(ifp));
        }

        if (sp->state[IDX_LCP] != STATE_INITIAL)
                lcp.Close(sp);
        sp->lcp.their_mru = 0;
        sp->pp_flags &= ~PP_CALLIN;
        ifp->if_flags &= ~IFF_RUNNING;
        sppp_flush(ifp);
}

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);
}

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

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.)
 */
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 = malloc (origlen, M_TEMP, M_NOWAIT);
        if (! buf)
                return (0);

        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; len -= p[1], p += p[1]) {
                if (p[1] < 2 || p[1] > len) {
                        free(buf, M_TEMP, origlen);
                        return (-1);
                }
                if (debug)
                        addlog("%s ", sppp_lcp_opt_name(*p));
                switch (*p) {
                case LCP_OPT_MAGIC:
                        /* Magic number. */
                        /* FALLTHROUGH, both are same length */
                case LCP_OPT_ASYNC_MAP:
                        /* Async control character map. */
                        if (len >= 6 && p[1] == 6)
                                continue;
                        if (debug)
                                addlog("[invalid] ");
                        break;
                case LCP_OPT_MRU:
                        /* Maximum receive unit. */
                        if (len >= 4 && p[1] == 4)
                                continue;
                        if (debug)
                                addlog("[invalid] ");
                        break;
                case LCP_OPT_AUTH_PROTO:
                        if (len < 4) {
                                if (debug)
                                        addlog("[invalid] ");
                                break;
                        }
                        authproto = (p[2] << 8) + p[3];
                        if (authproto == PPP_CHAP && p[1] != 5) {
                                if (debug)
                                        addlog("[invalid chap len] ");
                                break;
                        }
                        if (sp->myauth.proto == 0) {
                                /* we are not configured to do auth */
                                if (debug)
                                        addlog("[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)
                                addlog("[rej] ");
                        break;
                }
                /* Add the option to rejected list. */
                bcopy (p, r, p[1]);
                r += p[1];
                rlen += p[1];
        }
        if (rlen) {
                if (debug)
                        addlog(" send conf-rej\n");
                sppp_cp_send(sp, PPP_LCP, CONF_REJ, h->ident, rlen, buf);
                goto end;
        } else if (debug)
                addlog("\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)
                        addlog("%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) {
                                if (debug)
                                        addlog("0x%lx ", nmagic);
                                continue;
                        }
                        if (debug)
                                addlog("[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 -- check to be zero. */
                        if (! p[2] && ! p[3] && ! p[4] && ! p[5]) {
                                if (debug)
                                        addlog("[empty] ");
                                continue;
                        }
                        if (debug)
                                addlog("[non-empty] ");
                        /* suggest a zero one */
                        p[2] = p[3] = p[4] = p[5] = 0;
                        break;

                case LCP_OPT_MRU:
                        /*
                         * Maximum receive unit.  Always agreeable,
                         * but ignored by now.
                         */
                        sp->lcp.their_mru = p[2] * 256 + p[3];
                        if (debug)
                                addlog("%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)
                                        addlog("[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)
                                        addlog("[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) {
                if (++sp->fail_counter[IDX_LCP] >= sp->lcp.max_failure) {
                        if (debug)
                                addlog(" 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)
                                addlog(" send conf-nak\n");
                        sppp_cp_send(sp, PPP_LCP, CONF_NAK, h->ident, rlen, buf);
                }
                goto end;
        } else {
                if (debug)
                        addlog("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);
        }

 end:
        free(buf, M_TEMP, origlen);
        return (rlen == 0);
}

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

        len -= 4;

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

        p = (void*) (h+1);
        for (; len > 1; len -= p[1], p += p[1]) {
                if (p[1] < 2 || p[1] > len)
                        return;
                if (debug)
                        addlog("%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)
                                        addlog("[don't insist on auth "
                                               "for callout]");
                                sp->lcp.opts &= ~(1 << LCP_OPT_AUTH_PROTO);
                                break;
                        }
                        if (debug)
                                addlog("[access denied]\n");
                        lcp.Close(sp);
                        break;
                }
        }
        if (debug)
                addlog("\n");
}

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

        len -= 4;

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

        p = (void*) (h+1);
        for (; len > 1; len -= p[1], p += p[1]) {
                if (p[1] < 2 || p[1] > len)
                        return;
                if (debug)
                        addlog("%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)
                                                addlog("magic glitch ");
                                        sp->lcp.magic = arc4random();
                                } else {
                                        sp->lcp.magic = magic;
                                        if (debug)
                                                addlog("%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)
                                        addlog("%d ", mru);
                                if (mru < PP_MIN_MRU)
                                        mru = PP_MIN_MRU;
                                if (mru > PP_MAX_MRU)
                                        mru = PP_MAX_MRU;
                                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)
                                addlog("[access denied]\n");
                        lcp.Close(sp);
                        break;
                }
        }
        if (debug)
                addlog("\n");
}

void
sppp_lcp_tlu(struct sppp *sp)
{
        struct ifnet *ifp = &sp->pp_if;
        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);
                if (ifp->if_flags & IFF_DEBUG)
                        log(LOG_INFO, 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;

        sppp_set_phase(sp);

        /*
         * 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)
                                (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);
}

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

        sp->pp_phase = PHASE_TERMINATE;

        sppp_set_phase(sp);

        /*
         * 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);
                }
}

void
sppp_lcp_tls(struct sppp *sp)
{
        sp->pp_phase = PHASE_ESTABLISH;

        sppp_set_phase(sp);

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

void
sppp_lcp_tlf(struct sppp *sp)
{
        sp->pp_phase = PHASE_DEAD;
        sppp_set_phase(sp);

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

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 = arc4random();
                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;
        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.
 */
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.
 */
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.                          *
 *                                                                          *
 *--------------------------------------------------------------------------*
 */

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;
        task_set(&sp->ipcp.set_addr_task, sppp_set_ip_addrs, sp);
        task_set(&sp->ipcp.clear_addr_task, sppp_clear_ip_addrs, sp);
}

void
sppp_ipcp_destroy(struct sppp *sp)
{
        task_del(systq, &sp->ipcp.set_addr_task);
        task_del(systq, &sp->ipcp.clear_addr_task);
}

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

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

void
sppp_ipcp_open(struct sppp *sp)
{
        sppp_open_event(&ipcp, sp);
}

void
sppp_ipcp_close(struct sppp *sp)
{
        sppp_close_event(&ipcp, sp);
}

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.)
 */
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, buflen, debug = ifp->if_flags & IFF_DEBUG;
        u_int32_t hisaddr, desiredaddr;

        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.
         */
        buflen = len < 6? 6: len;
        buf = r = malloc (buflen, M_TEMP, M_NOWAIT);
        if (! buf)
                return (0);

        /* 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; len -= p[1], p += p[1]) {
                if (p[1] < 2 || p[1] > len) {
                        free(buf, M_TEMP, buflen);
                        return (-1);
                }
                if (debug)
                        addlog("%s ", sppp_ipcp_opt_name(*p));
                switch (*p) {
#ifdef notyet
                case IPCP_OPT_COMPRESSION:
                        if (len >= 6 && p[1] >= 6) {
                                /* correctly formed compress option */
                                continue;
                        }
                        if (debug)
                                addlog("[invalid] ");
                        break;
#endif
                case IPCP_OPT_ADDRESS:
                        if (len >= 6 && p[1] == 6) {
                                /* correctly formed address option */
                                continue;
                        }
                        if (debug)
                                addlog("[invalid] ");
                        break;
                default:
                        /* Others not supported. */
                        if (debug)
                                addlog("[rej] ");
                        break;
                }
                /* Add the option to rejected list. */
                bcopy (p, r, p[1]);
                r += p[1];
                rlen += p[1];
        }
        if (rlen) {
                if (debug)
                        addlog(" send conf-rej\n");
                sppp_cp_send(sp, PPP_IPCP, CONF_REJ, h->ident, rlen, buf);
                goto end;
        } else if (debug)
                addlog("\n");

        /* pass 2: parse option values */
        if (sp->ipcp.flags & IPCP_HISADDR_SEEN)
                hisaddr = sp->ipcp.req_hisaddr; /* we already agreed on that */
        else
                sppp_get_ip_addrs(sp, 0, &hisaddr, 0); /* user configuration */
        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)
                        addlog(" %s ", sppp_ipcp_opt_name(*p));
                switch (*p) {
#ifdef notyet
                case IPCP_OPT_COMPRESSION:
                        continue;
#endif
                case IPCP_OPT_ADDRESS:
                        desiredaddr = p[2] << 24 | p[3] << 16 |
                                p[4] << 8 | p[5];
                        if (desiredaddr == hisaddr ||
                            ((sp->ipcp.flags & IPCP_HISADDR_DYN) &&
                            desiredaddr != 0)) {
                                /*
                                 * Peer's address is same as our value,
                                 * or we have set it to 0.0.0.1 to
                                 * indicate that we do not really care,
                                 * this is agreeable.  Gonna conf-ack
                                 * it.
                                 */
                                if (debug)
                                        addlog("%s [ack] ",
                                               sppp_dotted_quad(desiredaddr));
                                /* record that we've seen it already */
                                sp->ipcp.flags |= IPCP_HISADDR_SEEN;
                                sp->ipcp.req_hisaddr = desiredaddr;
                                hisaddr = desiredaddr;
                                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.
                         */
                        if (debug) {
                                if (desiredaddr == 0)
                                        addlog("[addr requested] ");
                                else
                                        addlog("%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)) {
                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)
                        addlog("still need hisaddr ");
        }

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

 end:
        free(buf, M_TEMP, buflen);
        return (rlen == 0);
}

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

        len -= 4;

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

        p = (void*) (h+1);
        for (; len > 1; len -= p[1], p += p[1]) {
                if (p[1] < 2 || p[1] > len)
                        return;
                if (debug)
                        addlog("%s ", sppp_ipcp_opt_name(*p));
                switch (*p) {
                case IPCP_OPT_ADDRESS:
                        /*
                         * Peer doesn't grok address option.  This is
                         * bad.  XXX  Should we better give up here?
                         */
                        sp->ipcp.opts &= ~(1 << SPPP_IPCP_OPT_ADDRESS);
                        break;
#ifdef notyet
                case IPCP_OPT_COMPRESS:
                        sp->ipcp.opts &= ~(1 << SPPP_IPCP_OPT_COMPRESS);
                        break;
#endif
                case IPCP_OPT_PRIMDNS:
                        sp->ipcp.opts &= ~(1 << SPPP_IPCP_OPT_PRIMDNS);
                        break;
                case IPCP_OPT_SECDNS:
                        sp->ipcp.opts &= ~(1 << SPPP_IPCP_OPT_SECDNS);
                        break;
                }
        }
        if (debug)
                addlog("\n");
}

/*
 * Analyze the IPCP Configure-NAK option list, and adjust our
 * negotiation.
 */
void
sppp_ipcp_RCN_nak(struct sppp *sp, struct lcp_header *h, int len)
{
        u_char *p;
        struct ifnet *ifp = &sp->pp_if;
        int debug = ifp->if_flags & IFF_DEBUG;
        u_int32_t wantaddr;

        len -= 4;

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

        p = (void*) (h+1);
        for (; len > 1; len -= p[1], p += p[1]) {
                if (p[1] < 2 || p[1] > len)
                        return;
                if (debug)
                        addlog("%s ", sppp_ipcp_opt_name(*p));
                switch (*p) {
                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 << SPPP_IPCP_OPT_ADDRESS);
                                if (debug)
                                        addlog("[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.
                                 */
                                if (sp->ipcp.flags & IPCP_MYADDR_DYN) {
                                        if (debug)
                                                addlog("[agree] ");
                                        sp->ipcp.flags |= IPCP_MYADDR_SEEN;
                                        sp->ipcp.req_myaddr = wantaddr;
                                }
                        }
                        break;
#ifdef notyet
                case IPCP_OPT_COMPRESS:
                        /*
                         * Peer wants different compression parameters.
                         */
                        break;
#endif
                case IPCP_OPT_PRIMDNS:
                        if (len >= 6 && p[1] == 6)
                                memcpy(&sp->ipcp.dns[0].s_addr, p + 2,
                                    sizeof(sp->ipcp.dns[0]));
                        break;
                case IPCP_OPT_SECDNS:
                        if (len >= 6 && p[1] == 6)
                                memcpy(&sp->ipcp.dns[1].s_addr, p + 2,
                                    sizeof(sp->ipcp.dns[1]));
                        break;
                }
        }
        if (debug)
                addlog("\n");
}

void
sppp_ipcp_tlu(struct sppp *sp)
{
        if (sp->ipcp.req_myaddr != 0 || sp->ipcp.req_hisaddr != 0)
                task_add(systq, &sp->ipcp.set_addr_task);
}

void
sppp_ipcp_tld(struct sppp *sp)
{
}

void
sppp_ipcp_tls(struct sppp *sp)
{
        STDDCL;
        u_int32_t myaddr, hisaddr;

        sp->ipcp.flags &= ~(IPCP_HISADDR_SEEN|IPCP_MYADDR_SEEN|
            IPCP_MYADDR_DYN|IPCP_HISADDR_DYN);
        sp->ipcp.req_myaddr = 0;
        sp->ipcp.req_hisaddr = 0;
        memset(&sp->ipcp.dns, 0, sizeof(sp->ipcp.dns));

        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 == 0) {
                /* 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 == 0) {
                /*
                 * I don't have an assigned address, so i need to
                 * negotiate my address.
                 */
                sp->ipcp.flags |= IPCP_MYADDR_DYN;
                sp->ipcp.opts |= (1 << SPPP_IPCP_OPT_ADDRESS);
        }
        if (hisaddr >= 1 && hisaddr <= 255) {
                /*
                 * XXX - remove this hack!
                 * remote has no valid address, we need to get one assigned.
                 */
                sp->ipcp.flags |= IPCP_HISADDR_DYN;
        }

        /* negotiate name server addresses */
        sp->ipcp.opts |= (1 << SPPP_IPCP_OPT_PRIMDNS);
        sp->ipcp.opts |= (1 << SPPP_IPCP_OPT_SECDNS);

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

void
sppp_ipcp_tlf(struct sppp *sp)
{
        if (sp->ipcp.flags & (IPCP_MYADDR_DYN|IPCP_HISADDR_DYN))
                /* Some address was dynamic, clear it again. */
                task_add(systq, &sp->ipcp.clear_addr_task);

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

void
sppp_ipcp_scr(struct sppp *sp)
{
        char opt[6 /* compression */ + 6 /* address */ + 12 /* dns addrs */];
        u_int32_t ouraddr;
        int i = 0;

#ifdef notyet
        if (sp->ipcp.opts & (1 << SPPP_IPCP_OPT_COMPRESSION)) {
                opt[i++] = IPCP_OPT_COMPRESSION;
                opt[i++] = 6;
                opt[i++] = 0;   /* VJ header compression */
                opt[i++] = 0x2d; /* VJ header compression */
                opt[i++] = max_slot_id;
                opt[i++] = comp_slot_id;
        }
#endif

        if (sp->ipcp.opts & (1 << SPPP_IPCP_OPT_ADDRESS)) {
                if (sp->ipcp.flags & IPCP_MYADDR_SEEN)
                        /* not sure if this can ever happen */
                        ouraddr = sp->ipcp.req_myaddr;
                else
                        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;
        }

        if (sp->ipcp.opts & (1 << SPPP_IPCP_OPT_PRIMDNS)) {
                opt[i++] = IPCP_OPT_PRIMDNS;
                opt[i++] = 6;
                memcpy(&opt[i], &sp->ipcp.dns[0].s_addr,
                    sizeof(sp->ipcp.dns[0]));
                i += sizeof(sp->ipcp.dns[0]);
        }

        if (sp->ipcp.opts & (1 << SPPP_IPCP_OPT_SECDNS)) {
                opt[i++] = IPCP_OPT_SECDNS;
                opt[i++] = 6;
                memcpy(&opt[i], &sp->ipcp.dns[1].s_addr,
                    sizeof(sp->ipcp.dns[1]));
                i += sizeof(sp->ipcp.dns[1]);
        }

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

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

#ifdef INET6
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;
        task_set(&sp->ipv6cp.set_addr_task, sppp_update_ip6_addr, sp);
}

void
sppp_ipv6cp_destroy(struct sppp *sp)
{
        task_del(systq, &sp->ipv6cp.set_addr_task);
}

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

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

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

        sp->ipv6cp.flags &= ~(IPV6CP_MYIFID_SEEN|IPV6CP_MYIFID_DYN);

        sppp_get_ip6_addrs(sp, &myaddr, &hisaddr, NULL);
        /*
         * 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 the IFXF_NOINET6 flag is set, 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.opts |= (1 << IPV6CP_OPT_IFID);
        sppp_open_event(&ipv6cp, sp);
}

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

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

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, buflen, debug = ifp->if_flags & IFF_DEBUG;
        struct in6_addr myaddr, desiredaddr, suggestaddr;
        int ifidcount;
        int type;
        int collision, nohisaddr;
        char addr[INET6_ADDRSTRLEN];

        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.
         */
        buflen = len < 6? 6: len;
        buf = r = malloc (buflen, M_TEMP, M_NOWAIT);
        if (! buf)
                return (0);

        /* pass 1: see if we can recognize them */
        if (debug)
                log(LOG_DEBUG, "%s: 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] < 2 || p[1] > len) {
                        free(buf, M_TEMP, buflen);
                        return (-1);
                }
                if (debug)
                        addlog(" %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)
                                addlog(" [invalid]");
                        break;
#ifdef notyet
                case IPV6CP_OPT_COMPRESSION:
                        if (len >= 4 && p[1] >= 4) {
                                /* correctly formed compress option */
                                continue;
                        }
                        if (debug)
                                addlog(" [invalid]");
                        break;
#endif
                default:
                        /* Others not supported. */
                        if (debug)
                                addlog(" [rej]");
                        break;
                }
                /* Add the option to rejected list. */
                bcopy (p, r, p[1]);
                r += p[1];
                rlen += p[1];
        }
        if (rlen) {
                if (debug)
                        addlog(" send conf-rej\n");
                sppp_cp_send(sp, PPP_IPV6CP, CONF_REJ, h->ident, rlen, buf);
                goto end;
        } else if (debug)
                addlog("\n");

        /* pass 2: parse option values */
        if (sp->ipv6cp.flags & IPV6CP_MYIFID_DYN)
                myaddr = sp->ipv6cp.req_ifid.ifra_addr.sin6_addr;
        else
                sppp_get_ip6_addrs(sp, &myaddr, NULL, NULL);
        if (debug)
                log(LOG_DEBUG, "%s: 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)
                        addlog(" %s", sppp_ipv6cp_opt_name(*p));
                switch (*p) {
#ifdef notyet
                case IPV6CP_OPT_COMPRESSION:
                        continue;
#endif
                case IPV6CP_OPT_IFID:
                        memset(&desiredaddr, 0, sizeof(desiredaddr));
                        bcopy(&p[2], &desiredaddr.s6_addr[8], 8);
                        collision = (memcmp(&desiredaddr.s6_addr[8],
                                        &myaddr.s6_addr[8], 8) == 0);
                        nohisaddr = IN6_IS_ADDR_UNSPECIFIED(&desiredaddr);

                        desiredaddr.s6_addr16[0] = htons(0xfe80);

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

                                if (debug) {
                                        addlog(" %s [%s]",
                                            inet_ntop(AF_INET6, &desiredaddr,
                                                addr, sizeof(addr)),
                                            sppp_cp_type_name(type));
                                }
                                sppp_set_ip6_addr(sp, &myaddr, &desiredaddr);
                                continue;
                        }

                        memset(&suggestaddr, 0, sizeof(suggestaddr));
                        if (collision && nohisaddr) {
                                /* collision, hisaddr unknown - Conf-Rej */
                                type = CONF_REJ;
                                memset(&p[2], 0, 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)
                                addlog(" %s [%s]",
                                    inet_ntop(AF_INET6, &desiredaddr, addr,
                                        sizeof(addr)),
                                    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)
                        addlog(" send %s\n", sppp_cp_type_name(type));
                sppp_cp_send(sp, PPP_IPV6CP, type, h->ident, origlen, h + 1);
        } else {
#ifdef notdef
                if (type == CONF_ACK)
                        panic("IPv6CP RCR: CONF_ACK with non-zero rlen");
#endif

                if (debug) {
                        addlog(" send %s suggest %s\n",
                            sppp_cp_type_name(type),
                            inet_ntop(AF_INET6, &suggestaddr, addr,
                                sizeof(addr)));
                }
                sppp_cp_send(sp, PPP_IPV6CP, type, h->ident, rlen, buf);
        }

end:
        free(buf, M_TEMP, buflen);
        return (rlen == 0);
}

void
sppp_ipv6cp_RCN_rej(struct sppp *sp, struct lcp_header *h, int len)
{
        u_char *p;
        struct ifnet *ifp = &sp->pp_if;
        int debug = ifp->if_flags & IFF_DEBUG;

        len -= 4;

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

        p = (void *)(h + 1);
        for (; len > 1 && p[1]; len -= p[1], p += p[1]) {
                if (p[1] < 2 || p[1] > len)
                        return;
                if (debug)
                        addlog(" %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)
                addlog("\n");
        return;
}

void
sppp_ipv6cp_RCN_nak(struct sppp *sp, struct lcp_header *h, int len)
{
        u_char *p;
        struct ifnet *ifp = &sp->pp_if;
        int debug = ifp->if_flags & IFF_DEBUG;
        struct in6_addr suggestaddr;
        char addr[INET6_ADDRSTRLEN];

        len -= 4;

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

        p = (void*) (h+1);
        for (; len > 1; len -= p[1], p += p[1]) {
                if (p[1] < 2 || p[1] > len)
                        return;
                if (debug)
                        addlog("%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;
                        sp->ipv6cp.flags |= IPV6CP_MYIFID_DYN;
                        memset(&suggestaddr, 0, sizeof(suggestaddr));
                        bcopy(&p[2], &suggestaddr.s6_addr[8], 8);
                        if (IN6_IS_ADDR_UNSPECIFIED(&suggestaddr) ||
                            (sp->ipv6cp.flags & IPV6CP_MYIFID_SEEN)) {
                                /*
                                 * The peer didn't suggest anything,
                                 * or wants us to change a previously
                                 * suggested address.
                                 * Configure a new address for us.
                                 */
                                sppp_suggest_ip6_addr(sp, &suggestaddr);
                                sppp_set_ip6_addr(sp, &suggestaddr, NULL);
                                sp->ipv6cp.flags &= ~IPV6CP_MYIFID_SEEN;
                        } else {
                                /* Configure address suggested by peer. */
                                suggestaddr.s6_addr16[0] = htons(0xfe80);
                                sp->ipv6cp.opts |= (1 << IPV6CP_OPT_IFID);
                                if (debug)
                                        addlog(" [suggestaddr %s]",
                                            inet_ntop(AF_INET6, &suggestaddr,
                                                addr, sizeof(addr)));
                                sppp_set_ip6_addr(sp, &suggestaddr, NULL);
                                if (debug)
                                        addlog(" [agree]");
                                sp->ipv6cp.flags |= IPV6CP_MYIFID_SEEN;
                        }
                        break;
#ifdef notyet
                case IPV6CP_OPT_COMPRESS:
                        /*
                         * Peer wants different compression parameters.
                         */
                        break;
#endif
                }
        }
        if (debug)
                addlog("\n");
}

void
sppp_ipv6cp_tlu(struct sppp *sp)
{
}

void
sppp_ipv6cp_tld(struct sppp *sp)
{
}

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

void
sppp_ipv6cp_tlf(struct sppp *sp)
{
        /* we no longer need LCP */
        sp->lcp.protos &= ~(1 << IDX_IPV6CP);
        sppp_lcp_check_and_close(sp);
}

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)) {
                if (sp->ipv6cp.flags & IPV6CP_MYIFID_DYN)
                        ouraddr = sp->ipv6cp.req_ifid.ifra_addr.sin6_addr;
                else
                        sppp_get_ip6_addrs(sp, &ouraddr, NULL, NULL);
                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;
        sppp_cp_send(sp, PPP_IPV6CP, CONF_REQ, sp->confid[IDX_IPV6CP], i, opt);
}
#else /*INET6*/
void
sppp_ipv6cp_init(struct sppp *sp)
{
}

void
sppp_ipv6cp_destroy(struct sppp *sp)
{
}

void
sppp_ipv6cp_up(struct sppp *sp)
{
}

void
sppp_ipv6cp_down(struct sppp *sp)
{
}

void
sppp_ipv6cp_open(struct sppp *sp)
{
}

void
sppp_ipv6cp_close(struct sppp *sp)
{
}

void
sppp_ipv6cp_TO(void *sp)
{
}

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

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

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

void
sppp_ipv6cp_tlu(struct sppp *sp)
{
}

void
sppp_ipv6cp_tld(struct sppp *sp)
{
}

void
sppp_ipv6cp_tls(struct sppp *sp)
{
}

void
sppp_ipv6cp_tlf(struct sppp *sp)
{
}

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.
 */
void
sppp_chap_input(struct sppp *sp, struct mbuf *m)
{
        STDDCL;
        struct lcp_header *h;
        int len, x;
        u_char *value, *name, digest[AUTHCHALEN], 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));
                                if (len > 4)
                                        sppp_print_bytes((u_char*) (h+1), len-4);
                                addlog(">\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);
                        addlog(" value-size=%d value=", value_len);
                        sppp_print_bytes(value, value_len);
                        addlog(">\n");
                }

                /* Compute reply value. */
                MD5Init(&ctx);
                MD5Update(&ctx, &h->ident, 1);
                MD5Update(&ctx, sp->myauth.secret, strlen(sp->myauth.secret));
                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,
                               strlen(sp->myauth.name),
                               sp->myauth.name,
                               0);
                break;

        case CHAP_SUCCESS:
                if (debug) {
                        log(LOG_DEBUG, SPP_FMT "chap success",
                            SPP_ARGS(ifp));
                        if (len > 4) {
                                addlog(": ");
                                sppp_print_string((char*)(h + 1), len - 4);
                        }
                        addlog("\n");
                }
                x = splnet();
                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.
                         */
                        splx(x);
                        break;
                }
                splx(x);
                sppp_phase_network(sp);
                break;

        case CHAP_FAILURE:
                if (debug) {
                        log(LOG_INFO, SPP_FMT "chap failure",
                            SPP_ARGS(ifp));
                        if (len > 4) {
                                addlog(": ");
                                sppp_print_string((char*)(h + 1), len - 4);
                        }
                        addlog("\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));
                                if (len > 4)
                                        sppp_print_bytes((u_char*)(h+1), len-4);
                                addlog(">\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 != strlen(sp->hisauth.name)
                    || 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);
                        addlog(" != expected ");
                        sppp_print_string(sp->hisauth.name,
                            strlen(sp->hisauth.name));
                        addlog("\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);
                        addlog(" value-size=%d value=", value_len);
                        sppp_print_bytes(value, value_len);
                        addlog(">\n");
                }
                if (value_len != AUTHCHALEN) {
                        if (debug)
                                log(LOG_DEBUG,
                                    SPP_FMT "chap bad hash value length: "
                                    "%d bytes, should be %d\n",
                                    SPP_ARGS(ifp), value_len,
                                    AUTHCHALEN);
                        break;
                }

                MD5Init(&ctx);
                MD5Update(&ctx, &h->ident, 1);
                MD5Update(&ctx, sp->hisauth.secret, strlen(sp->hisauth.secret));
                MD5Update(&ctx, sp->chap_challenge, AUTHCHALEN);
                MD5Final(digest, &ctx);

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

                if (value_len != sizeof digest ||
                    timingsafe_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));
                        if (len > 4)
                                sppp_print_bytes((u_char*)(h+1), len-4);
                        addlog(">\n");
                }
                break;

        }
}

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;
}

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 */
}

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

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

        s = splnet();
        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;
                        /* FALLTHROUGH */
                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;
                }

        splx(s);
}

void
sppp_chap_tlu(struct sppp *sp)
{
        STDDCL;
        int i = 0, x;

        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 + arc4random_uniform(1 + 810 - 300);

                timeout_add_sec(&sp->ch[IDX_CHAP], i);
        }

        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)
                        addlog("next re-challenge in %d seconds\n", i);
                else
                        addlog("re-challenging suppressed\n");
        }

        x = splnet();
        /* 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.
                 */
                splx(x);
                return;
        }
        splx(x);

        /*
         * 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);
}

void
sppp_chap_tld(struct sppp *sp)
{
        STDDCL;

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

        lcp.Close(sp);
}

void
sppp_chap_scr(struct sppp *sp)
{
        u_char clen;

        /* Compute random challenge. */
        arc4random_buf(sp->chap_challenge, sizeof(sp->chap_challenge));
        clen = AUTHCHALEN;

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

        sppp_auth_send(&chap, sp, CHAP_CHALLENGE, sp->confid[IDX_CHAP],
                       sizeof clen, (const char *)&clen,
                       (size_t)AUTHCHALEN, sp->chap_challenge,
                       strlen(sp->myauth.name),
                       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.  */
void
sppp_pap_input(struct sppp *sp, struct mbuf *m)
{
        STDDCL;
        struct lcp_header *h;
        int len, x;
        u_char *name, *passwd, mlen;
        int name_len, passwd_len;

        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));
                                if (len > 4)
                                        sppp_print_bytes((u_char*)(h+1), len-4);
                                addlog(">\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);
                        addlog(" passwd=");
                        sppp_print_string((char*)passwd, passwd_len);
                        addlog(">\n");
                }
                if (name_len > AUTHMAXLEN ||
                    passwd_len > AUTHMAXLEN ||
                    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:
                UNTIMEOUT(sppp_pap_my_TO, (void *)sp, sp->pap_my_to_ch);
                if (debug) {
                        log(LOG_DEBUG, SPP_FMT "pap success",
                            SPP_ARGS(ifp));
                        name_len = *((char *)h);
                        if (len > 5 && name_len) {
                                addlog(": ");
                                sppp_print_string((char*)(h+1), name_len);
                        }
                        addlog("\n");
                }
                x = splnet();
                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.
                         */
                        splx(x);
                        break;
                }
                splx(x);
                sppp_phase_network(sp);
                break;

        case PAP_NAK:
                UNTIMEOUT(sppp_pap_my_TO, (void *)sp, sp->pap_my_to_ch);
                if (debug) {
                        log(LOG_INFO, SPP_FMT "pap failure",
                            SPP_ARGS(ifp));
                        name_len = *((char *)h);
                        if (len > 5 && name_len) {
                                addlog(": ");
                                sppp_print_string((char*)(h+1), name_len);
                        }
                        addlog("\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));
                        if (len > 4)
                                sppp_print_bytes((u_char*)(h+1), len-4);
                        addlog(">\n");
                }
                break;

        }
}

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;
}

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);
                timeout_add_sec(&sp->pap_my_to_ch, sp->lcp.timeout);
        }
}

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.
 */
void
sppp_pap_TO(void *cookie)
{
        struct sppp *sp = (struct sppp *)cookie;
        STDDCL;
        int s;

        s = splnet();
        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;
                }

        splx(s);
}

/*
 * 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.
 */
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);
}

void
sppp_pap_tlu(struct sppp *sp)
{
        STDDCL;
        int x;

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

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

        x = splnet();
        /* 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.
                 */
                splx(x);
                return;
        }
        splx(x);
        sppp_phase_network(sp);
}

void
sppp_pap_tld(struct sppp *sp)
{
        STDDCL;

        if (debug)
                log(LOG_DEBUG, SPP_FMT "pap tld\n", SPP_ARGS(ifp));
        UNTIMEOUT(pap.TO, (void *)sp, sp->ch[IDX_PAP]);
        UNTIMEOUT(sppp_pap_my_TO, (void *)sp, sp->pap_my_to_ch);
        sp->lcp.protos &= ~(1 << IDX_PAP);

        lcp.Close(sp);
}

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

        sp->confid[IDX_PAP] = ++sp->pp_seq;
        pwdlen = strlen(sp->myauth.secret);
        idlen = strlen(sp->myauth.name);

        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.
 *
 * Variadic function, each of the elements for the ellipsis is of type
 * ``size_t mlen, const u_char *msg''.  Processing will stop iff
 * mlen == 0.
 */

void
sppp_auth_send(const struct cp *cp, struct sppp *sp,
                unsigned int type, u_int id, ...)
{
        STDDCL;
        struct lcp_header *lh;
        struct mbuf *m;
        u_char *p;
        int len, s;
        unsigned int mlen;
        const char *msg;
        va_list ap;

        MGETHDR (m, M_DONTWAIT, MT_DATA);
        if (! m)
                return;
        m->m_pkthdr.ph_ifidx = 0;
        m->m_pkthdr.pf.prio = sp->pp_if.if_llprio;

        *mtod(m, u_int16_t *) = htons(cp->proto);
        lh = (struct lcp_header *)(mtod(m, u_int8_t *) + 2);

        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 - PKTHDRLEN - 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 = PKTHDRLEN + 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));
                if (len)
                        sppp_print_bytes((u_char*) (lh+1), len);
                addlog(">\n");
        }

        len = m->m_pkthdr.len + sp->pp_framebytes;
        if (mq_enqueue(&sp->pp_cpq, m) != 0) {
                ifp->if_oerrors++;
                return;
        }

        ifp->if_obytes += len;
        s = splnet();
        if_start(ifp);
        splx(s);
}

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

        NET_LOCK();
        s = splnet();
        getmicrouptime(&tv);
        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 if LCP not opened yet. */
                if (sp->pp_phase < PHASE_AUTHENTICATE)
                        continue;

                /* No echo reply, but maybe user data passed through? */
                if ((tv.tv_sec - sp->pp_last_receive) < NORECV_TIME) {
                        sp->pp_alivecnt = 0;
                        continue;
                }

                if (sp->pp_alivecnt >= MAXALIVECNT) {
                        /* No keepalive packets got.  Stop the interface. */
                        if_down (ifp);
                        mq_purge(&sp->pp_cpq);
                        log(LOG_INFO, SPP_FMT "LCP keepalive timeout\n",
                            SPP_ARGS(ifp));
                        sp->pp_alivecnt = 0;

                        /* we are down, close all open protocols */
                        lcp.Close(sp);

                        /* And now prepare LCP to reestablish the link,
                         * if configured to do so. */
                        sppp_cp_change_state(&lcp, sp, STATE_STOPPED);

                        /* Close connection immediately, completion of this
                         * will summon the magic needed to reestablish it. */
                        if (sp->pp_tlf)
                                sp->pp_tlf(sp);
                        continue;
                }
                if (sp->pp_alivecnt < MAXALIVECNT)
                        ++sp->pp_alivecnt;
                if (sp->pp_phase >= PHASE_AUTHENTICATE) {
                        u_int32_t nmagic = htonl(sp->lcp.magic);
                        sp->lcp.echoid = ++sp->pp_seq;
                        sppp_cp_send (sp, PPP_LCP, ECHO_REQ,
                                sp->lcp.echoid, 4, &nmagic);
                }
        }
        splx(s);
        NET_UNLOCK();
        timeout_add_sec(&keepalive_ch, 10);
}

/*
 * Get both IP addresses.
 */
void
sppp_get_ip_addrs(struct sppp *sp, u_int32_t *src, u_int32_t *dst,
    u_int32_t *srcmask)
{
        struct ifnet *ifp = &sp->pp_if;
        struct ifaddr *ifa;
        struct sockaddr_in *si, *sm = 0;
        u_int32_t ssrc, ddst;

        sm = NULL;
        ssrc = ddst = 0;
        /*
         * Pick the first AF_INET address from the list,
         * aliases don't make any sense on a p2p link anyway.
         */
        si = 0;
        TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
        {
                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 (ifa) {
                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);
}

int
sppp_update_gw_walker(struct rtentry *rt, void *arg, unsigned int id)
{
        struct ifnet *ifp = arg;

        if (rt->rt_ifidx == ifp->if_index) {
                if (rt->rt_ifa->ifa_dstaddr->sa_family !=
                    rt->rt_gateway->sa_family ||
                    !ISSET(rt->rt_flags, RTF_GATEWAY))
                        return (0);     /* do not modify non-gateway routes */
                rt_setgate(rt, rt->rt_ifa->ifa_dstaddr, ifp->if_rdomain);
        }
        return (0);
}

void
sppp_update_gw(struct ifnet *ifp)
{
        u_int tid;

        /* update routing table */
        for (tid = 0; tid <= rtmap_limit; tid++) {
                rtable_walk(tid, AF_INET, NULL, sppp_update_gw_walker, ifp);
        }
}

/*
 * Task adding addresses from process context.
 * If an address is 0, leave it the way it is.
 */
void
sppp_set_ip_addrs(void *arg1)
{
        struct sppp *sp = arg1;
        u_int32_t myaddr;
        u_int32_t hisaddr;
        struct ifnet *ifp = &sp->pp_if;
        int debug = ifp->if_flags & IFF_DEBUG;
        struct ifaddr *ifa;
        struct sockaddr_in *si;
        struct sockaddr_in *dest;

        sppp_get_ip_addrs(sp, &myaddr, &hisaddr, NULL);
        if ((sp->ipcp.flags & IPCP_MYADDR_DYN) &&
            (sp->ipcp.flags & IPCP_MYADDR_SEEN))
                myaddr = sp->ipcp.req_myaddr;
        if ((sp->ipcp.flags & IPCP_HISADDR_DYN) &&
            (sp->ipcp.flags & IPCP_HISADDR_SEEN))
                hisaddr = sp->ipcp.req_hisaddr;


        NET_LOCK();
        /*
         * Pick the first AF_INET address from the list,
         * aliases don't make any sense on a p2p link anyway.
         */

        si = 0;
        TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
        {
                if (ifa->ifa_addr->sa_family == AF_INET)
                {
                        si = (struct sockaddr_in *)ifa->ifa_addr;
                        dest = (struct sockaddr_in *)ifa->ifa_dstaddr;
                        if (si)
                                break;
                }
        }

        if (ifa && si) {
                int error;
                struct sockaddr_in new_sin = *si;
                struct sockaddr_in new_dst = *dest;

                in_ifscrub(ifp, ifatoia(ifa));

                if (myaddr != 0)
                        new_sin.sin_addr.s_addr = htonl(myaddr);
                if (hisaddr != 0) {
                        new_dst.sin_addr.s_addr = htonl(hisaddr);
                        if (new_dst.sin_addr.s_addr != dest->sin_addr.s_addr) {
                                sp->ipcp.saved_hisaddr = dest->sin_addr.s_addr;
                                *dest = new_dst; /* fix dstaddr in place */
                        }
                }
                if (!(error = in_ifinit(ifp, ifatoia(ifa), &new_sin, 0)))
                        if_addrhooks_run(ifp);
                if (debug && error) {
                        log(LOG_DEBUG, SPP_FMT "sppp_set_ip_addrs: in_ifinit "
                        " failed, error=%d\n", SPP_ARGS(ifp), error);
                        goto out;
                }
                sppp_update_gw(ifp);
                sppp_update_dns(ifp);
        }
out:
        NET_UNLOCK();
}

/*
 * Task clearing addresses from process context.
 * Clear IP addresses.
 */
void
sppp_clear_ip_addrs(void *arg1)
{
        struct sppp *sp = (struct sppp *)arg1;
        struct ifnet *ifp = &sp->pp_if;
        int debug = ifp->if_flags & IFF_DEBUG;
        struct ifaddr *ifa;
        struct sockaddr_in *si;
        struct sockaddr_in *dest;
        u_int32_t remote;

        NET_LOCK();

        if (sp->ipcp.flags & IPCP_HISADDR_DYN)
                remote = sp->ipcp.saved_hisaddr;
        else
                sppp_get_ip_addrs(sp, 0, &remote, 0);

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

        si = 0;
        TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) {
                if (ifa->ifa_addr->sa_family == AF_INET) {
                        si = (struct sockaddr_in *)ifa->ifa_addr;
                        dest = (struct sockaddr_in *)ifa->ifa_dstaddr;
                        if (si)
                                break;
                }
        }

        if (ifa && si) {
                int error;
                struct sockaddr_in new_sin = *si;

                in_ifscrub(ifp, ifatoia(ifa));
                if (sp->ipcp.flags & IPCP_MYADDR_DYN)
                        new_sin.sin_addr.s_addr = 0;
                if (sp->ipcp.flags & IPCP_HISADDR_DYN)
                        /* replace peer addr in place */
                        dest->sin_addr.s_addr = sp->ipcp.saved_hisaddr;
                if (!(error = in_ifinit(ifp, ifatoia(ifa), &new_sin, 0)))
                        if_addrhooks_run(ifp);
                if (debug && error) {
                        log(LOG_DEBUG, SPP_FMT "sppp_clear_ip_addrs: in_ifinit "
                        " failed, error=%d\n", SPP_ARGS(ifp), error);
                        goto out;
                }
                sppp_update_gw(ifp);

                memset(sp->ipcp.dns, 0, sizeof(sp->ipcp.dns));
                sppp_update_dns(ifp);
        }
out:
        NET_UNLOCK();
}


#ifdef INET6
/*
 * Get both IPv6 addresses.
 */
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 in6_ifaddr *ia6;
        struct in6_addr ssrc, ddst;

        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.
         */
        ia6 = in6ifa_ifpforlinklocal(ifp, 0);
        if (ia6) {
                if (!IN6_IS_ADDR_UNSPECIFIED(&ia6->ia_addr.sin6_addr)) {
                        bcopy(&ia6->ia_addr.sin6_addr, &ssrc, sizeof(ssrc));
                        if (srcmask) {
                                bcopy(&ia6->ia_prefixmask.sin6_addr, srcmask,
                                    sizeof(*srcmask));
                        }
                }

                if (!IN6_IS_ADDR_UNSPECIFIED(&ia6->ia_dstaddr.sin6_addr))
                        bcopy(&ia6->ia_dstaddr.sin6_addr, &ddst, sizeof(ddst));
        }

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

/* Task to update my IPv6 address from process context. */
void
sppp_update_ip6_addr(void *arg)
{
        struct sppp *sp = arg;
        struct ifnet *ifp = &sp->pp_if;
        struct in6_aliasreq *ifra = &sp->ipv6cp.req_ifid;
        struct in6_ifaddr *ia6;
        int error;

        NET_LOCK();

        ia6 = in6ifa_ifpforlinklocal(ifp, 0);
        if (ia6 == NULL) {
                /* IPv6 disabled? */
                goto out;
        }

        /*
         * Changing the link-local address requires purging all
         * existing addresses and routes for the interface first.
         */
        if (sp->ipv6cp.flags & IPV6CP_MYIFID_DYN) {
                in6_ifdetach(ifp);
                error = in6_ifattach_linklocal(ifp, &ifra->ifra_addr.sin6_addr);
                if (error)
                        log(LOG_ERR, SPP_FMT
                            "could not update IPv6 address (error %d)\n",
                            SPP_ARGS(ifp), error);
                goto out;
        }

        /*
         * Code below changes address parameters only, not the address itself.
         */

        /* Destination address can only be set for /128. */
        if (memcmp(&ia6->ia_prefixmask.sin6_addr, &in6mask128,
            sizeof(in6mask128)) != 0) {
                ifra->ifra_dstaddr.sin6_len = 0;
                ifra->ifra_dstaddr.sin6_family = AF_UNSPEC;
        }

        ifra->ifra_lifetime = ia6->ia6_lifetime;

        error = in6_update_ifa(ifp, ifra, ia6);
        if (error) {
                log(LOG_ERR, SPP_FMT
                    "could not update IPv6 address (error %d)\n",
                    SPP_ARGS(ifp), error);
        }
out:
        NET_UNLOCK();
}

/*
 * Configure my link-local address.
 */
void
sppp_set_ip6_addr(struct sppp *sp, const struct in6_addr *src,
        const struct in6_addr *dst)
{
        struct ifnet *ifp = &sp->pp_if;
        struct in6_aliasreq *ifra = &sp->ipv6cp.req_ifid;

        bzero(ifra, sizeof(*ifra));
        bcopy(ifp->if_xname, ifra->ifra_name, sizeof(ifra->ifra_name));

        ifra->ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
        ifra->ifra_addr.sin6_family = AF_INET6;
        ifra->ifra_addr.sin6_addr = *src;
        if (dst) {
                ifra->ifra_dstaddr.sin6_len = sizeof(struct sockaddr_in6);
                ifra->ifra_dstaddr.sin6_family = AF_INET6;
                ifra->ifra_dstaddr.sin6_addr = *dst;
        } else
                ifra->ifra_dstaddr.sin6_family = AF_UNSPEC;

        /*
         * Don't change the existing prefixlen.
         * It is common to use a /64 for IPv6 over point-to-point links
         * to allow e.g. neighbour discovery and autoconf to work.
         * But it is legal to use other values.
         */
        ifra->ifra_prefixmask.sin6_family = AF_UNSPEC;

        task_add(systq, &sp->ipv6cp.set_addr_task);
}

/*
 * Generate an address that differs from our existing address.
 */
void
sppp_suggest_ip6_addr(struct sppp *sp, struct in6_addr *suggest)
{
        struct in6_addr myaddr;
        u_int32_t random;

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

        myaddr.s6_addr[8] &= ~0x02;     /* u bit to "local" */

        random = arc4random();
        if ((random & 0xff) == 0 && (random & 0xff00) == 0) {
                myaddr.s6_addr[14] ^= 0xff;
                myaddr.s6_addr[15] ^= 0xff;
        } else {
                myaddr.s6_addr[14] ^= (random & 0xff);
                myaddr.s6_addr[15] ^= ((random & 0xff00) >> 8);
        }
        myaddr.s6_addr16[1] = 0; /* KAME hack: clear ifindex */
        bcopy(&myaddr, suggest, sizeof(myaddr));
}
#endif /*INET6*/

int
sppp_get_params(struct sppp *sp, struct ifreq *ifr)
{
        int cmd;

        if (copyin((caddr_t)ifr->ifr_data, &cmd, sizeof cmd) != 0)
                return EFAULT;

        switch (cmd) {
        case SPPPIOGDEFS:
        {
                struct spppreq *spr;

                spr = malloc(sizeof(*spr), M_DEVBUF, M_WAITOK);
                spr->cmd = cmd;
                spr->phase = sp->pp_phase;

                if (copyout(spr, (caddr_t)ifr->ifr_data, sizeof(*spr)) != 0) {
                        free(spr, M_DEVBUF, sizeof(*spr));
                        return EFAULT;
                }
                free(spr, M_DEVBUF, sizeof(*spr));
                break;
        }
        case SPPPIOGMAUTH:
        case SPPPIOGHAUTH:
        {
                struct sauthreq *spa;
                struct sauth *auth;

                spa = malloc(sizeof(*spa), M_DEVBUF, M_WAITOK);
                auth = (cmd == SPPPIOGMAUTH) ? &sp->myauth : &sp->hisauth;
                bzero(spa, sizeof(*spa));
                spa->proto = auth->proto;
                spa->flags = auth->flags;

                /* do not copy the secret, and only let root know the name */
                if (auth->name != NULL && suser(curproc) == 0)
                        strlcpy(spa->name, auth->name, sizeof(spa->name));

                if (copyout(spa, (caddr_t)ifr->ifr_data, sizeof(*spa)) != 0) {
                        free(spa, M_DEVBUF, sizeof(*spa));
                        return EFAULT;
                }
                free(spa, M_DEVBUF, sizeof(*spa));
                break;
        }
        case SPPPIOGDNS:
        {
                struct sdnsreq *spd;

                spd = malloc(sizeof(*spd), M_DEVBUF, M_WAITOK);

                spd->cmd = cmd;
                memcpy(spd->dns, sp->ipcp.dns, sizeof(spd->dns));

                if (copyout(spd, (caddr_t)ifr->ifr_data, sizeof(*spd)) != 0) {
                        free(spd, M_DEVBUF, 0);
                        return EFAULT;
                }

                free(spd, M_DEVBUF, sizeof(*spd));
                break;
        }
        default:
                return EINVAL;
        }

        return 0;
}


int
sppp_set_params(struct sppp *sp, struct ifreq *ifr)
{
        int cmd;

        if (copyin((caddr_t)ifr->ifr_data, &cmd, sizeof cmd) != 0)
                return EFAULT;

        switch (cmd) {
        case SPPPIOSDEFS:
        {
                struct spppreq *spr;

                spr = malloc(sizeof(*spr), M_DEVBUF, M_WAITOK);

                if (copyin((caddr_t)ifr->ifr_data, spr, sizeof(*spr)) != 0) {
                        free(spr, M_DEVBUF, sizeof(*spr));
                        return EFAULT;
                }
                /*
                 * Also, we only allow for authentication parameters to be
                 * specified.
                 *
                 * XXX Should allow to set or clear pp_flags.
                 */
                free(spr, M_DEVBUF, sizeof(*spr));
                break;
        }
        case SPPPIOSMAUTH:
        case SPPPIOSHAUTH:
        {
                /*
                 * 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 SPPPIOGXAUTH call).  However, the
                 * secrets are cleared if the authentication protocol is
                 * reset to 0.
                 */

                struct sauthreq *spa;
                struct sauth *auth;
                char *p;
                int len;

                spa = malloc(sizeof(*spa), M_DEVBUF, M_WAITOK);

                auth = (cmd == SPPPIOSMAUTH) ? &sp->myauth : &sp->hisauth;

                if (copyin((caddr_t)ifr->ifr_data, spa, sizeof(*spa)) != 0) {
                        free(spa, M_DEVBUF, sizeof(*spa));
                        return EFAULT;
                }

                if (spa->proto != 0 && spa->proto != PPP_PAP &&
                    spa->proto != PPP_CHAP) {
                        free(spa, M_DEVBUF, sizeof(*spa));
                        return EINVAL;
                }

                if (spa->proto == 0) {
                        /* resetting auth */
                        if (auth->name != NULL)
                                free(auth->name, M_DEVBUF,
                                    strlen(auth->name) + 1);
                        if (auth->secret != NULL)
                                free(auth->secret, M_DEVBUF,
                                    strlen(auth->secret) + 1);
                        bzero(auth, sizeof *auth);
                        explicit_bzero(sp->chap_challenge, sizeof sp->chap_challenge);
                } else {
                        /* setting/changing auth */
                        auth->proto = spa->proto;
                        auth->flags = spa->flags;

                        spa->name[AUTHMAXLEN - 1] = '\0';
                        len = strlen(spa->name) + 1;
                        p = malloc(len, M_DEVBUF, M_WAITOK);
                        strlcpy(p, spa->name, len);
                        if (auth->name != NULL)
                                free(auth->name, M_DEVBUF,
                                    strlen(auth->name) + 1);
                        auth->name = p;

                        if (spa->secret[0] != '\0') {
                                spa->secret[AUTHMAXLEN - 1] = '\0';
                                len = strlen(spa->secret) + 1;
                                p = malloc(len, M_DEVBUF, M_WAITOK);
                                strlcpy(p, spa->secret, len);
                                if (auth->secret != NULL)
                                        free(auth->secret, M_DEVBUF,
                                            strlen(auth->secret) + 1);
                                auth->secret = p;
                        } else if (!auth->secret) {
                                p = malloc(1, M_DEVBUF, M_WAITOK);
                                p[0] = '\0';
                                auth->secret = p;
                        }
                }
                free(spa, M_DEVBUF, sizeof(*spa));
                break;
        }
        default:
                return EINVAL;
        }

        return (ENETRESET);
}

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

        sp->pp_phase = PHASE_NETWORK;

        sppp_set_phase(sp);

        /* 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);
}


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";
        }
        snprintf (buf, sizeof buf, "0x%x", type);
        return buf;
}

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";
                }
        }
        snprintf (buf, sizeof buf, "0x%x", type);
        return buf;
}

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";
        }
        snprintf (buf, sizeof buf, "0x%x", opt);
        return buf;
}

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";
        case IPCP_OPT_PRIMDNS:          return "primdns";
        case IPCP_OPT_SECDNS:           return "secdns";
        }
        snprintf (buf, sizeof buf, "0x%x", opt);
        return buf;
}

#ifdef INET6
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";
        }
        snprintf (buf, sizeof buf, "0x%x", opt);
        return buf;
}
#endif

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";
}

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";
}

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_IPV6CP: return "ipv6cp";
        case PPP_PAP:   return "pap";
        case PPP_CHAP:  return "chap";
        }
        snprintf(buf, sizeof buf, "0x%x", (unsigned)proto);
        return buf;
}

void
sppp_print_bytes(const u_char *p, u_short len)
{
        addlog(" %02x", *p++);
        while (--len > 0)
                addlog("-%02x", *p++);
}

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 > '~')
                        addlog("\\x%x", c);
                else
                        addlog("%c", c);
        }
}

const char *
sppp_dotted_quad(u_int32_t addr)
{
        static char s[16];
        snprintf(s, sizeof 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 */
void
sppp_null(struct sppp *unused)
{
        /* do just nothing */
}

void
sppp_set_phase(struct sppp *sp)
{
        STDDCL;
        int lstate;

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

        /* set link state */
        if (sp->pp_phase == PHASE_NETWORK)
                lstate = LINK_STATE_UP;
        else
                lstate = LINK_STATE_DOWN;

        if (ifp->if_link_state != lstate) {
                ifp->if_link_state = lstate;
                if_link_state_change(ifp);
        }
}

void
sppp_update_dns(struct ifnet *ifp)
{
        struct rt_addrinfo info;
        struct sockaddr_rtdns rtdns;
        struct sppp *sp = ifp->if_softc;
        size_t sz = 0;
        int i, flag = 0;

        memset(&rtdns, 0, sizeof(rtdns));
        memset(&info, 0, sizeof(info));

        for (i = 0; i < IPCP_MAX_DNSSRV; i++) {
                if (sp->ipcp.dns[i].s_addr == INADDR_ANY)
                        break;
                sz = sizeof(sp->ipcp.dns[i]);
                memcpy(rtdns.sr_dns + i * sz, &sp->ipcp.dns[i].s_addr, sz);
                flag = RTF_UP;
        }

        rtdns.sr_family = AF_INET;
        rtdns.sr_len = 2 + i * sz;
        info.rti_info[RTAX_DNS] = srtdnstosa(&rtdns);

        rtm_proposal(ifp, &info, flag, RTP_PROPOSAL_PPP);
}

void
sppp_rtrequest(struct ifnet *ifp, int req, struct rtentry *rt)
{
        if (req == RTM_PROPOSAL) {
                KERNEL_LOCK();
                sppp_update_dns(ifp);
                KERNEL_UNLOCK();
                return;
        }

        p2p_rtrequest(ifp, req, rt);
}