/*-
 * SPDX-License-Identifier: BSD-4-Clause
 *
 * Copyright (c) 1995 Gordon Ross, Adam Glass
 * Copyright (c) 1992 Regents of the University of California.
 * All rights reserved.
 *
 * This software was developed by the Computer Systems Engineering group
 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
 * contributed to Berkeley.
 *
 * 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Lawrence Berkeley Laboratory and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS 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.
 *
 * based on:
 *      nfs/krpc_subr.c
 *      $NetBSD: krpc_subr.c,v 1.10 1995/08/08 20:43:43 gwr Exp $
 */

#define IN_HISTORICAL_NETS              /* include class masks */

#include <sys/cdefs.h>
#include "opt_bootp.h"
#include "opt_nfs.h"
#include "opt_rootdevname.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/endian.h>
#include <sys/jail.h>
#include <sys/kernel.h>
#include <sys/sockio.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/mbuf.h>
#include <sys/proc.h>
#include <sys/reboot.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sysctl.h>
#include <sys/uio.h>

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

#include <netinet/in.h>
#include <netinet/in_var.h>
#include <net/if_types.h>
#include <net/if_dl.h>
#include <net/vnet.h>

#include <nfs/nfsproto.h>
#include <nfsclient/nfs.h>
#include <nfs/nfsdiskless.h>
#include <nfs/krpc.h>
#include <nfs/xdr_subs.h>

#define BOOTP_MIN_LEN           300     /* Minimum size of bootp udp packet */

#ifndef BOOTP_SETTLE_DELAY
#define BOOTP_SETTLE_DELAY 3
#endif

/* 
 * Wait 10 seconds for interface appearance
 * USB ethernet adapters might require some time to pop up
 */
#ifndef BOOTP_IFACE_WAIT_TIMEOUT
#define BOOTP_IFACE_WAIT_TIMEOUT        10
#endif

/*
 * What is the longest we will wait before re-sending a request?
 * Note this is also the frequency of "RPC timeout" messages.
 * The re-send loop count sup linearly to this maximum, so the
 * first complaint will happen after (1+2+3+4+5)=15 seconds.
 */
#define MAX_RESEND_DELAY 5      /* seconds */

/* Definitions from RFC951 */
struct bootp_packet {
        u_int8_t op;
        u_int8_t htype;
        u_int8_t hlen;
        u_int8_t hops;
        u_int32_t xid;
        u_int16_t secs;
        u_int16_t flags;
        struct in_addr ciaddr;
        struct in_addr yiaddr;
        struct in_addr siaddr;
        struct in_addr giaddr;
        unsigned char chaddr[16];
        char sname[64];
        char file[128];
        unsigned char vend[1222];
};

struct bootpc_ifcontext {
        STAILQ_ENTRY(bootpc_ifcontext) next;
        struct bootp_packet call;
        struct bootp_packet reply;
        int replylen;
        int overload;
        union {
                struct ifreq _ifreq;
                struct in_aliasreq _in_alias_req;
        } _req;
#define ireq    _req._ifreq
#define iareq   _req._in_alias_req
        if_t ifp;
        struct sockaddr_dl *sdl;
        struct sockaddr_in myaddr;
        struct sockaddr_in netmask;
        struct sockaddr_in gw;
        int gotgw;
        int gotnetmask;
        int gotrootpath;
        int outstanding;
        int sentmsg;
        u_int32_t xid;
        enum {
                IF_BOOTP_UNRESOLVED,
                IF_BOOTP_RESOLVED,
                IF_BOOTP_FAILED,
                IF_DHCP_UNRESOLVED,
                IF_DHCP_OFFERED,
                IF_DHCP_RESOLVED,
                IF_DHCP_FAILED,
        } state;
        int dhcpquerytype;              /* dhcp type sent */
        struct in_addr dhcpserver;
        int gotdhcpserver;
        uint16_t mtu;
};

#define TAG_MAXLEN 1024
struct bootpc_tagcontext {
        char buf[TAG_MAXLEN + 1];
        int overload;
        int badopt;
        int badtag;
        int foundopt;
        int taglen;
};

struct bootpc_globalcontext {
        STAILQ_HEAD(, bootpc_ifcontext) interfaces;
        u_int32_t xid;
        int any_root_overrides;
        int gotrootpath;
        int gotgw;
        int ifnum;
        int secs;
        int starttime;
        struct bootp_packet reply;
        int replylen;
        struct bootpc_ifcontext *setrootfs;
        struct bootpc_ifcontext *sethostname;
        struct bootpc_tagcontext tmptag;
        struct bootpc_tagcontext tag;
};

#define IPPORT_BOOTPC 68
#define IPPORT_BOOTPS 67

#define BOOTP_REQUEST 1
#define BOOTP_REPLY 2

/* Common tags */
#define TAG_PAD           0  /* Pad option, implicit length 1 */
#define TAG_SUBNETMASK    1  /* RFC 950 subnet mask */
#define TAG_ROUTERS       3  /* Routers (in order of preference) */
#define TAG_HOSTNAME     12  /* Client host name */
#define TAG_ROOT         17  /* Root path */
#define TAG_INTF_MTU     26  /* Interface MTU Size (RFC2132) */

/* DHCP specific tags */
#define TAG_OVERLOAD     52  /* Option Overload */
#define TAG_MAXMSGSIZE   57  /* Maximum DHCP Message Size */

#define TAG_END         255  /* End Option (i.e. no more options) */

/* Overload values */
#define OVERLOAD_FILE     1
#define OVERLOAD_SNAME    2

/* Site specific tags: */
#define TAG_ROOTOPTS    130
#define TAG_COOKIE      134     /* ascii info for userland, via sysctl */

#define TAG_DHCP_MSGTYPE 53
#define TAG_DHCP_REQ_ADDR 50
#define TAG_DHCP_SERVERID 54
#define TAG_DHCP_LEASETIME 51

#define TAG_VENDOR_INDENTIFIER 60

#define DHCP_NOMSG    0
#define DHCP_DISCOVER 1
#define DHCP_OFFER    2
#define DHCP_REQUEST  3
#define DHCP_ACK      5

/* NFS read/write block size */
#ifndef BOOTP_BLOCKSIZE
#define BOOTP_BLOCKSIZE 8192
#endif

static char bootp_cookie[128];
static struct socket *bootp_so;
SYSCTL_STRING(_kern, OID_AUTO, bootp_cookie, CTLFLAG_RD,
        bootp_cookie, 0, "Cookie (T134) supplied by bootp server");

/* mountd RPC */
static int      md_mount(struct sockaddr_in *mdsin, char *path, u_char *fhp,
                    int *fhsizep, struct nfs_args *args, struct thread *td);
static int      setfs(struct sockaddr_in *addr, char *path, char *p,
                    const struct in_addr *siaddr);
static int      getdec(char **ptr);
static int      getip(char **ptr, struct in_addr *ip);
static void     mountopts(struct nfs_args *args, char *p);
static int      xdr_opaque_decode(struct mbuf **ptr, u_char *buf, int len);
static int      xdr_int_decode(struct mbuf **ptr, int *iptr);
static void     print_in_addr(struct in_addr addr);
static void     print_sin_addr(struct sockaddr_in *addr);
static void     clear_sinaddr(struct sockaddr_in *sin);
static void     allocifctx(struct bootpc_globalcontext *gctx);
static void     bootpc_compose_query(struct bootpc_ifcontext *ifctx,
                    struct thread *td);
static unsigned char *bootpc_tag(struct bootpc_tagcontext *tctx,
                    struct bootp_packet *bp, int len, int tag);
static void bootpc_tag_helper(struct bootpc_tagcontext *tctx,
                    unsigned char *start, int len, int tag);

#ifdef BOOTP_DEBUG
void bootpboot_p_iflist(void);
#endif

static int      bootpc_call(struct bootpc_globalcontext *gctx,
                    struct thread *td);

static void     bootpc_fakeup_interface(struct bootpc_ifcontext *ifctx,
                    struct thread *td);

static void     bootpc_adjust_interface(struct bootpc_ifcontext *ifctx,
                    struct bootpc_globalcontext *gctx, struct thread *td);

static void     bootpc_decode_reply(struct nfsv3_diskless *nd,
                    struct bootpc_ifcontext *ifctx,
                    struct bootpc_globalcontext *gctx);

static int      bootpc_received(struct bootpc_globalcontext *gctx,
                    struct bootpc_ifcontext *ifctx);

static __inline int bootpc_ifctx_isresolved(struct bootpc_ifcontext *ifctx);
static __inline int bootpc_ifctx_isunresolved(struct bootpc_ifcontext *ifctx);
static __inline int bootpc_ifctx_isfailed(struct bootpc_ifcontext *ifctx);

/*
 * In order to have multiple active interfaces with address 0.0.0.0
 * and be able to send data to a selected interface, we first set
 * mask to /8 on all interfaces, and temporarily set it to /0 when
 * doing sosend().
 */

#ifdef BOOTP_DEBUG
static u_int
bootpboot_p_ifa(void *ifp, struct ifaddr *ifa, u_int count __unused)
{

        printf("%s flags %x, addr ",
               if_name(ifp), if_getflags(ifp));
        print_sin_addr((struct sockaddr_in *) ifa->ifa_addr);
        printf(", broadcast ");
        print_sin_addr((struct sockaddr_in *) ifa->ifa_dstaddr);
        printf(", netmask ");
        print_sin_addr((struct sockaddr_in *) ifa->ifa_netmask);
        printf("\n");

        return (0);
}

void
bootpboot_p_iflist(void)
{
        struct epoch_tracker et;
        struct if_iter iter;
        if_t ifp;

        printf("Interface list:\n");
        NET_EPOCH_ENTER(et);
        for (ifp = if_iter_start(&iter); ifp != NULL; ifp = if_iter_next(&iter))
                if_foreach_addr_type(ifp, AF_INET, bootpboot_p_ifa, ifp);
        if_iter_finish(&iter);
        NET_EPOCH_EXIT(et);
}
#endif /* defined(BOOTP_DEBUG) */

static void
clear_sinaddr(struct sockaddr_in *sin)
{

        bzero(sin, sizeof(*sin));
        sin->sin_len = sizeof(*sin);
        sin->sin_family = AF_INET;
        sin->sin_addr.s_addr = INADDR_ANY; /* XXX: htonl(INAADDR_ANY) ? */
        sin->sin_port = 0;
}

static void
allocifctx(struct bootpc_globalcontext *gctx)
{
        struct bootpc_ifcontext *ifctx;

        ifctx = malloc(sizeof(*ifctx), M_TEMP, M_WAITOK | M_ZERO);
        ifctx->xid = gctx->xid;
#ifdef BOOTP_NO_DHCP
        ifctx->state = IF_BOOTP_UNRESOLVED;
#else
        ifctx->state = IF_DHCP_UNRESOLVED;
#endif
        gctx->xid += 0x100;
        STAILQ_INSERT_TAIL(&gctx->interfaces, ifctx, next);
}

static __inline int
bootpc_ifctx_isresolved(struct bootpc_ifcontext *ifctx)
{

        if (ifctx->state == IF_BOOTP_RESOLVED ||
            ifctx->state == IF_DHCP_RESOLVED)
                return 1;
        return 0;
}

static __inline int
bootpc_ifctx_isunresolved(struct bootpc_ifcontext *ifctx)
{

        if (ifctx->state == IF_BOOTP_UNRESOLVED ||
            ifctx->state == IF_DHCP_UNRESOLVED)
                return 1;
        return 0;
}

static __inline int
bootpc_ifctx_isfailed(struct bootpc_ifcontext *ifctx)
{

        if (ifctx->state == IF_BOOTP_FAILED ||
            ifctx->state == IF_DHCP_FAILED)
                return 1;
        return 0;
}

static int
bootpc_received(struct bootpc_globalcontext *gctx,
    struct bootpc_ifcontext *ifctx)
{
        unsigned char dhcpreplytype;
        char *p;

        /*
         * Need timeout for fallback to less
         * desirable alternative.
         */

        /* This call used for the side effect (badopt flag) */
        (void) bootpc_tag(&gctx->tmptag, &gctx->reply,
                          gctx->replylen,
                          TAG_END);

        /* If packet is invalid, ignore it */
        if (gctx->tmptag.badopt != 0)
                return 0;

        p = bootpc_tag(&gctx->tmptag, &gctx->reply,
                       gctx->replylen, TAG_DHCP_MSGTYPE);
        if (p != NULL)
                dhcpreplytype = *p;
        else
                dhcpreplytype = DHCP_NOMSG;

        switch (ifctx->dhcpquerytype) {
        case DHCP_DISCOVER:
                if (dhcpreplytype != DHCP_OFFER         /* Normal DHCP offer */
#ifndef BOOTP_FORCE_DHCP
                    && dhcpreplytype != DHCP_NOMSG      /* Fallback to BOOTP */
#endif
                        )
                        return 0;
                break;
        case DHCP_REQUEST:
                if (dhcpreplytype != DHCP_ACK)
                        return 0;
        case DHCP_NOMSG:
                break;
        }

        /* Ignore packet unless it gives us a root tag we didn't have */

        if ((ifctx->state == IF_BOOTP_RESOLVED ||
             (ifctx->dhcpquerytype == DHCP_DISCOVER &&
              (ifctx->state == IF_DHCP_OFFERED ||
               ifctx->state == IF_DHCP_RESOLVED))) &&
            (bootpc_tag(&gctx->tmptag, &ifctx->reply,
                        ifctx->replylen,
                        TAG_ROOT) != NULL ||
             bootpc_tag(&gctx->tmptag, &gctx->reply,
                        gctx->replylen,
                        TAG_ROOT) == NULL))
                return 0;

        bcopy(&gctx->reply, &ifctx->reply, gctx->replylen);
        ifctx->replylen = gctx->replylen;

        /* XXX: Only reset if 'perfect' response */
        if (ifctx->state == IF_BOOTP_UNRESOLVED)
                ifctx->state = IF_BOOTP_RESOLVED;
        else if (ifctx->state == IF_DHCP_UNRESOLVED &&
                 ifctx->dhcpquerytype == DHCP_DISCOVER) {
                if (dhcpreplytype == DHCP_OFFER)
                        ifctx->state = IF_DHCP_OFFERED;
                else
                        ifctx->state = IF_BOOTP_RESOLVED;       /* Fallback */
        } else if (ifctx->state == IF_DHCP_OFFERED &&
                   ifctx->dhcpquerytype == DHCP_REQUEST)
                ifctx->state = IF_DHCP_RESOLVED;

        if (ifctx->dhcpquerytype == DHCP_DISCOVER &&
            ifctx->state != IF_BOOTP_RESOLVED) {
                p = bootpc_tag(&gctx->tmptag, &ifctx->reply,
                               ifctx->replylen, TAG_DHCP_SERVERID);
                if (p != NULL && gctx->tmptag.taglen == 4) {
                        memcpy(&ifctx->dhcpserver, p, 4);
                        ifctx->gotdhcpserver = 1;
                } else
                        ifctx->gotdhcpserver = 0;
                return 1;
        }

        ifctx->gotrootpath = (bootpc_tag(&gctx->tmptag, &ifctx->reply,
                                         ifctx->replylen,
                                         TAG_ROOT) != NULL);
        ifctx->gotgw = (bootpc_tag(&gctx->tmptag, &ifctx->reply,
                                   ifctx->replylen,
                                   TAG_ROUTERS) != NULL);
        ifctx->gotnetmask = (bootpc_tag(&gctx->tmptag, &ifctx->reply,
                                        ifctx->replylen,
                                        TAG_SUBNETMASK) != NULL);
        return 1;
}

static int
bootpc_call(struct bootpc_globalcontext *gctx, struct thread *td)
{
        struct sockaddr_in *sin, dst;
        struct uio auio;
        struct sockopt sopt;
        struct iovec aio;
        int error, on, rcvflg, timo, len;
        time_t atimo;
        time_t rtimo;
        struct timeval tv;
        struct bootpc_ifcontext *ifctx;
        int outstanding;
        int gotrootpath;
        int retry;
        const char *s;

        tv.tv_sec = 1;
        tv.tv_usec = 0;
        bzero(&sopt, sizeof(sopt));
        sopt.sopt_dir = SOPT_SET;
        sopt.sopt_level = SOL_SOCKET;
        sopt.sopt_name = SO_RCVTIMEO;
        sopt.sopt_val = &tv;
        sopt.sopt_valsize = sizeof tv;

        error = sosetopt(bootp_so, &sopt);
        if (error != 0)
                goto out;

        /*
         * Enable broadcast.
         */
        on = 1;
        sopt.sopt_name = SO_BROADCAST;
        sopt.sopt_val = &on;
        sopt.sopt_valsize = sizeof on;

        error = sosetopt(bootp_so, &sopt);
        if (error != 0)
                goto out;

        /*
         * Disable routing.
         */

        on = 1;
        sopt.sopt_name = SO_DONTROUTE;
        sopt.sopt_val = &on;
        sopt.sopt_valsize = sizeof on;

        error = sosetopt(bootp_so, &sopt);
        if (error != 0)
                goto out;

        /*
         * Bind the local endpoint to a bootp client port.
         */
        sin = &dst;
        clear_sinaddr(sin);
        sin->sin_port = htons(IPPORT_BOOTPC);
        error = sobind(bootp_so, (struct sockaddr *)sin, td);
        if (error != 0) {
                printf("bind failed\n");
                goto out;
        }

        /*
         * Setup socket address for the server.
         */
        sin = &dst;
        clear_sinaddr(sin);
        sin->sin_addr.s_addr = INADDR_BROADCAST;
        sin->sin_port = htons(IPPORT_BOOTPS);

        /*
         * Send it, repeatedly, until a reply is received,
         * but delay each re-send by an increasing amount.
         * If the delay hits the maximum, start complaining.
         */
        timo = 0;
        rtimo = 0;
        for (;;) {
                outstanding = 0;
                gotrootpath = 0;

                STAILQ_FOREACH(ifctx, &gctx->interfaces, next) {
                        if (bootpc_ifctx_isresolved(ifctx) != 0 &&
                            bootpc_tag(&gctx->tmptag, &ifctx->reply,
                                       ifctx->replylen,
                                       TAG_ROOT) != NULL)
                                gotrootpath = 1;
                }

                STAILQ_FOREACH(ifctx, &gctx->interfaces, next) {
                        struct in_aliasreq *ifra = &ifctx->iareq;
                        sin = (struct sockaddr_in *)&ifra->ifra_mask;

                        ifctx->outstanding = 0;
                        if (bootpc_ifctx_isresolved(ifctx)  != 0 &&
                            gotrootpath != 0) {
                                continue;
                        }
                        if (bootpc_ifctx_isfailed(ifctx) != 0)
                                continue;

                        outstanding++;
                        ifctx->outstanding = 1;

                        /* Proceed to next step in DHCP negotiation */
                        if ((ifctx->state == IF_DHCP_OFFERED &&
                             ifctx->dhcpquerytype != DHCP_REQUEST) ||
                            (ifctx->state == IF_DHCP_UNRESOLVED &&
                             ifctx->dhcpquerytype != DHCP_DISCOVER) ||
                            (ifctx->state == IF_BOOTP_UNRESOLVED &&
                             ifctx->dhcpquerytype != DHCP_NOMSG)) {
                                ifctx->sentmsg = 0;
                                bootpc_compose_query(ifctx, td);
                        }

                        /* Send BOOTP request (or re-send). */

                        if (ifctx->sentmsg == 0) {
                                switch(ifctx->dhcpquerytype) {
                                case DHCP_DISCOVER:
                                        s = "DHCP Discover";
                                        break;
                                case DHCP_REQUEST:
                                        s = "DHCP Request";
                                        break;
                                case DHCP_NOMSG:
                                default:
                                        s = "BOOTP Query";
                                        break;
                                }
                                printf("Sending %s packet from "
                                       "interface %s (%*D)\n",
                                       s,
                                       ifctx->ireq.ifr_name,
                                       ifctx->sdl->sdl_alen,
                                       (unsigned char *) LLADDR(ifctx->sdl),
                                       ":");
                                ifctx->sentmsg = 1;
                        }

                        aio.iov_base = (caddr_t) &ifctx->call;
                        aio.iov_len = sizeof(ifctx->call);

                        auio.uio_iov = &aio;
                        auio.uio_iovcnt = 1;
                        auio.uio_segflg = UIO_SYSSPACE;
                        auio.uio_rw = UIO_WRITE;
                        auio.uio_offset = 0;
                        auio.uio_resid = sizeof(ifctx->call);
                        auio.uio_td = td;

                        /* Set netmask to 0.0.0.0 */
                        clear_sinaddr(sin);
                        error = ifioctl(bootp_so, SIOCAIFADDR, (caddr_t)ifra,
                            td);
                        if (error != 0)
                                panic("%s: SIOCAIFADDR, error=%d", __func__,
                                    error);

                        error = sosend(bootp_so, (struct sockaddr *) &dst,
                                       &auio, NULL, NULL, 0, td);
                        if (error != 0)
                                printf("%s: sosend: %d state %08x\n", __func__,
                                    error, (int )bootp_so->so_state);

                        /* Set netmask to 255.0.0.0 */
                        sin->sin_addr.s_addr = htonl(0xff000000);
                        error = ifioctl(bootp_so, SIOCAIFADDR, (caddr_t)ifra,
                            td);
                        if (error != 0)
                                panic("%s: SIOCAIFADDR, error=%d", __func__,
                                    error);
                }

                if (outstanding == 0 &&
                    (rtimo == 0 || time_second >= rtimo)) {
                        error = 0;
                        goto out;
                }

                /* Determine new timeout. */
                if (timo < MAX_RESEND_DELAY)
                        timo++;
                else {
                        printf("DHCP/BOOTP timeout for server ");
                        print_sin_addr(&dst);
                        printf("\n");
                }

                /*
                 * Wait for up to timo seconds for a reply.
                 * The socket receive timeout was set to 1 second.
                 */
                atimo = timo + time_second;
                while (time_second < atimo) {
                        aio.iov_base = (caddr_t) &gctx->reply;
                        aio.iov_len = sizeof(gctx->reply);

                        auio.uio_iov = &aio;
                        auio.uio_iovcnt = 1;
                        auio.uio_segflg = UIO_SYSSPACE;
                        auio.uio_rw = UIO_READ;
                        auio.uio_offset = 0;
                        auio.uio_resid = sizeof(gctx->reply);
                        auio.uio_td = td;

                        rcvflg = 0;
                        error = soreceive(bootp_so, NULL, &auio,
                                          NULL, NULL, &rcvflg);
                        gctx->secs = time_second - gctx->starttime;
                        STAILQ_FOREACH(ifctx, &gctx->interfaces, next) {
                                if (bootpc_ifctx_isresolved(ifctx) != 0 ||
                                    bootpc_ifctx_isfailed(ifctx) != 0)
                                        continue;

                                ifctx->call.secs = htons(gctx->secs);
                        }
                        if (error == EWOULDBLOCK)
                                continue;
                        if (error != 0)
                                goto out;
                        len = sizeof(gctx->reply) - auio.uio_resid;

                        /* Do we have the required number of bytes ? */
                        if (len < BOOTP_MIN_LEN)
                                continue;
                        gctx->replylen = len;

                        /* Is it a reply? */
                        if (gctx->reply.op != BOOTP_REPLY)
                                continue;

                        /* Is this an answer to our query */
                        STAILQ_FOREACH(ifctx, &gctx->interfaces, next) {
                                if (gctx->reply.xid != ifctx->call.xid)
                                        continue;

                                /* Same HW address size ? */
                                if (gctx->reply.hlen != ifctx->call.hlen)
                                        continue;

                                /* Correct HW address ? */
                                if (bcmp(gctx->reply.chaddr,
                                         ifctx->call.chaddr,
                                         ifctx->call.hlen) != 0)
                                        continue;

                                break;
                        }

                        if (ifctx != NULL) {
                                s =  bootpc_tag(&gctx->tmptag,
                                                &gctx->reply,
                                                gctx->replylen,
                                                TAG_DHCP_MSGTYPE);
                                if (s != NULL) {
                                        switch (*s) {
                                        case DHCP_OFFER:
                                                s = "DHCP Offer";
                                                break;
                                        case DHCP_ACK:
                                                s = "DHCP Ack";
                                                break;
                                        default:
                                                s = "DHCP (unexpected)";
                                                break;
                                        }
                                } else
                                        s = "BOOTP Reply";

                                printf("Received %s packet"
                                       " on %s from ",
                                       s,
                                       ifctx->ireq.ifr_name);
                                print_in_addr(gctx->reply.siaddr);
                                if (gctx->reply.giaddr.s_addr !=
                                    htonl(INADDR_ANY)) {
                                        printf(" via ");
                                        print_in_addr(gctx->reply.giaddr);
                                }
                                if (bootpc_received(gctx, ifctx) != 0) {
                                        printf(" (accepted)");
                                        if (ifctx->outstanding) {
                                                ifctx->outstanding = 0;
                                                outstanding--;
                                        }
                                        /* Network settle delay */
                                        if (outstanding == 0)
                                                atimo = time_second +
                                                        BOOTP_SETTLE_DELAY;
                                } else
                                        printf(" (ignored)");
                                if (ifctx->gotrootpath || 
                                    gctx->any_root_overrides) {
                                        gotrootpath = 1;
                                        rtimo = time_second +
                                                BOOTP_SETTLE_DELAY;
                                        if (ifctx->gotrootpath)
                                                printf(" (got root path)");
                                }
                                printf("\n");
                        }
                } /* while secs */
#ifdef BOOTP_TIMEOUT
                if (gctx->secs > BOOTP_TIMEOUT && BOOTP_TIMEOUT > 0)
                        break;
#endif
                /* Force a retry if halfway in DHCP negotiation */
                retry = 0;
                STAILQ_FOREACH(ifctx, &gctx->interfaces, next)
                        if (ifctx->state == IF_DHCP_OFFERED) {
                                if (ifctx->dhcpquerytype == DHCP_DISCOVER)
                                        retry = 1;
                                else
                                        ifctx->state = IF_DHCP_UNRESOLVED;
                        }

                if (retry != 0)
                        continue;

                if (gotrootpath != 0) {
                        gctx->gotrootpath = gotrootpath;
                        if (rtimo != 0 && time_second >= rtimo)
                                break;
                }
        } /* forever send/receive */

        /*
         * XXX: These are errors of varying seriousness being silently
         * ignored
         */

        STAILQ_FOREACH(ifctx, &gctx->interfaces, next)
                if (bootpc_ifctx_isresolved(ifctx) == 0) {
                        printf("%s timeout for interface %s\n",
                               ifctx->dhcpquerytype != DHCP_NOMSG ?
                               "DHCP" : "BOOTP",
                               ifctx->ireq.ifr_name);
                }

        if (gctx->gotrootpath != 0) {
#if 0
                printf("Got a root path, ignoring remaining timeout\n");
#endif
                error = 0;
                goto out;
        }
#ifndef BOOTP_NFSROOT
        STAILQ_FOREACH(ifctx, &gctx->interfaces, next)
                if (bootpc_ifctx_isresolved(ifctx) != 0) {
                        error = 0;
                        goto out;
                }
#endif
        error = ETIMEDOUT;

out:
        return (error);
}

static void
bootpc_fakeup_interface(struct bootpc_ifcontext *ifctx, struct thread *td)
{
        struct ifreq *ifr;
        struct in_aliasreq *ifra;
        struct sockaddr_in *sin;
        int error;

        ifr = &ifctx->ireq;
        ifra = &ifctx->iareq;

        /*
         * Bring up the interface.
         *
         * Get the old interface flags and or IFF_UP into them; if
         * IFF_UP set blindly, interface selection can be clobbered.
         */
        error = ifioctl(bootp_so, SIOCGIFFLAGS, (caddr_t)ifr, td);
        if (error != 0)
                panic("%s: SIOCGIFFLAGS, error=%d", __func__, error);
        ifr->ifr_flags |= IFF_UP;
        error = ifioctl(bootp_so, SIOCSIFFLAGS, (caddr_t)ifr, td);
        if (error != 0)
                panic("%s: SIOCSIFFLAGS, error=%d", __func__, error);

        /*
         * Do enough of ifconfig(8) so that the chosen interface
         * can talk to the servers. Set address to 0.0.0.0/8 and
         * broadcast address to local broadcast.
         */
        sin = (struct sockaddr_in *)&ifra->ifra_addr;
        clear_sinaddr(sin);
        sin = (struct sockaddr_in *)&ifra->ifra_mask;
        clear_sinaddr(sin);
        sin->sin_addr.s_addr = htonl(0xff000000);
        sin = (struct sockaddr_in *)&ifra->ifra_broadaddr;
        clear_sinaddr(sin);
        sin->sin_addr.s_addr = htonl(INADDR_BROADCAST);
        error = ifioctl(bootp_so, SIOCAIFADDR, (caddr_t)ifra, td);
        if (error != 0)
                panic("%s: SIOCAIFADDR, error=%d", __func__, error);
}

static void
bootpc_shutdown_interface(struct bootpc_ifcontext *ifctx, struct thread *td)
{
        struct ifreq *ifr;
        struct sockaddr_in *sin;
        int error;

        ifr = &ifctx->ireq;

        printf("Shutdown interface %s\n", ifctx->ireq.ifr_name);
        error = ifioctl(bootp_so, SIOCGIFFLAGS, (caddr_t)ifr, td);
        if (error != 0)
                panic("%s: SIOCGIFFLAGS, error=%d", __func__, error);
        ifr->ifr_flags &= ~IFF_UP;
        error = ifioctl(bootp_so, SIOCSIFFLAGS, (caddr_t)ifr, td);
        if (error != 0)
                panic("%s: SIOCSIFFLAGS, error=%d", __func__, error);

        sin = (struct sockaddr_in *) &ifr->ifr_addr;
        clear_sinaddr(sin);
        error = ifioctl(bootp_so, SIOCDIFADDR, (caddr_t) ifr, td);
        if (error != 0)
                panic("%s: SIOCDIFADDR, error=%d", __func__, error);
}

static void
bootpc_adjust_interface(struct bootpc_ifcontext *ifctx,
    struct bootpc_globalcontext *gctx, struct thread *td)
{
        int error;
        struct sockaddr_in *sin;
        struct ifreq *ifr;
        struct in_aliasreq *ifra;
        struct sockaddr_in *myaddr;
        struct sockaddr_in *netmask;

        ifr = &ifctx->ireq;
        ifra = &ifctx->iareq;
        myaddr = &ifctx->myaddr;
        netmask = &ifctx->netmask;

        if (bootpc_ifctx_isresolved(ifctx) == 0) {
                /* Shutdown interfaces where BOOTP failed */
                bootpc_shutdown_interface(ifctx, td);
                return;
        }

        printf("Adjusted interface %s", ifctx->ireq.ifr_name);

        /* Do BOOTP interface options */
        if (ifctx->mtu != 0) {
                printf(" (MTU=%d%s)", ifctx->mtu, 
                    (ifctx->mtu > 1514) ? "/JUMBO" : "");
                ifr->ifr_mtu = ifctx->mtu;
                error = ifioctl(bootp_so, SIOCSIFMTU, (caddr_t) ifr, td);
                if (error != 0)
                        panic("%s: SIOCSIFMTU, error=%d", __func__, error);
        }
        printf("\n");

        /*
         * Do enough of ifconfig(8) so that the chosen interface
         * can talk to the servers.  (just set the address)
         */
        sin = (struct sockaddr_in *) &ifr->ifr_addr;
        clear_sinaddr(sin);
        error = ifioctl(bootp_so, SIOCDIFADDR, (caddr_t) ifr, td);
        if (error != 0)
                panic("%s: SIOCDIFADDR, error=%d", __func__, error);

        bcopy(myaddr, &ifra->ifra_addr, sizeof(*myaddr));
        bcopy(netmask, &ifra->ifra_mask, sizeof(*netmask));
        clear_sinaddr(&ifra->ifra_broadaddr);
        ifra->ifra_broadaddr.sin_addr.s_addr = myaddr->sin_addr.s_addr |
            ~netmask->sin_addr.s_addr;

        error = ifioctl(bootp_so, SIOCAIFADDR, (caddr_t)ifra, td);
        if (error != 0)
                panic("%s: SIOCAIFADDR, error=%d", __func__, error);
}

static void
bootpc_add_default_route(struct bootpc_ifcontext *ifctx)
{
        int error;
        struct sockaddr_in defdst;
        struct sockaddr_in defmask;
        struct rt_addrinfo info;
        struct rib_cmd_info rc;

        if (ifctx->gw.sin_addr.s_addr == htonl(INADDR_ANY))
                return;

        clear_sinaddr(&defdst);
        clear_sinaddr(&defmask);

        bzero((caddr_t)&info, sizeof(info));
        info.rti_flags = RTF_UP | RTF_GATEWAY | RTF_STATIC;
        info.rti_info[RTAX_DST] = (struct sockaddr *)&defdst;
        info.rti_info[RTAX_NETMASK] = (struct sockaddr *)&defmask;
        info.rti_info[RTAX_GATEWAY] = (struct sockaddr *)&ifctx->gw;

        error = rib_action(RT_DEFAULT_FIB, RTM_ADD, &info, &rc);

        if (error != 0) {
                printf("%s: RTM_ADD, error=%d\n", __func__, error);
        }
}

static void
bootpc_remove_default_route(struct bootpc_ifcontext *ifctx)
{
        int error;
        struct sockaddr_in defdst;
        struct sockaddr_in defmask;
        struct rt_addrinfo info;
        struct rib_cmd_info rc;

        if (ifctx->gw.sin_addr.s_addr == htonl(INADDR_ANY))
                return;

        clear_sinaddr(&defdst);
        clear_sinaddr(&defmask);

        bzero((caddr_t)&info, sizeof(info));
        info.rti_flags = RTF_UP | RTF_GATEWAY | RTF_STATIC;
        info.rti_info[RTAX_DST] = (struct sockaddr *)&defdst;
        info.rti_info[RTAX_NETMASK] = (struct sockaddr *)&defmask;
        info.rti_info[RTAX_GATEWAY] = (struct sockaddr *)&ifctx->gw;

        error = rib_action(RT_DEFAULT_FIB, RTM_DELETE, &info, &rc);
        if (error != 0) {
                printf("%s: RTM_DELETE, error=%d\n", __func__, error);
        }
}

static int
setfs(struct sockaddr_in *addr, char *path, char *p,
    const struct in_addr *siaddr)
{

        if (getip(&p, &addr->sin_addr) == 0) {
                if (siaddr != NULL && *p == '/')
                        bcopy(siaddr, &addr->sin_addr, sizeof(struct in_addr));
                else
                        return 0;
        } else {
                if (*p != ':')
                        return 0;
                p++;
        }
                
        addr->sin_len = sizeof(struct sockaddr_in);
        addr->sin_family = AF_INET;

        strlcpy(path, p, MNAMELEN);
        return 1;
}

static int
getip(char **ptr, struct in_addr *addr)
{
        char *p;
        unsigned int ip;
        int val;

        p = *ptr;
        ip = 0;
        if (((val = getdec(&p)) < 0) || (val > 255))
                return 0;
        ip = val << 24;
        if (*p != '.')
                return 0;
        p++;
        if (((val = getdec(&p)) < 0) || (val > 255))
                return 0;
        ip |= (val << 16);
        if (*p != '.')
                return 0;
        p++;
        if (((val = getdec(&p)) < 0) || (val > 255))
                return 0;
        ip |= (val << 8);
        if (*p != '.')
                return 0;
        p++;
        if (((val = getdec(&p)) < 0) || (val > 255))
                return 0;
        ip |= val;

        addr->s_addr = htonl(ip);
        *ptr = p;
        return 1;
}

static int
getdec(char **ptr)
{
        char *p;
        int ret;

        p = *ptr;
        ret = 0;
        if ((*p < '0') || (*p > '9'))
                return -1;
        while ((*p >= '0') && (*p <= '9')) {
                ret = ret * 10 + (*p - '0');
                p++;
        }
        *ptr = p;
        return ret;
}

static void
mountopts(struct nfs_args *args, char *p)
{
        args->version = NFS_ARGSVERSION;
        args->rsize = BOOTP_BLOCKSIZE;
        args->wsize = BOOTP_BLOCKSIZE;
        args->flags = NFSMNT_RSIZE | NFSMNT_WSIZE | NFSMNT_RESVPORT;
        args->sotype = SOCK_DGRAM;
        if (p != NULL)
                nfs_parse_options(p, args);
}

static int
xdr_opaque_decode(struct mbuf **mptr, u_char *buf, int len)
{
        struct mbuf *m;
        int alignedlen;

        m = *mptr;
        alignedlen = ( len + 3 ) & ~3;

        if (m->m_len < alignedlen) {
                m = m_pullup(m, alignedlen);
                if (m == NULL) {
                        *mptr = NULL;
                        return EBADRPC;
                }
        }
        bcopy(mtod(m, u_char *), buf, len);
        m_adj(m, alignedlen);
        *mptr = m;
        return 0;
}

static int
xdr_int_decode(struct mbuf **mptr, int *iptr)
{
        u_int32_t i;

        if (xdr_opaque_decode(mptr, (u_char *) &i, sizeof(u_int32_t)) != 0)
                return EBADRPC;
        *iptr = fxdr_unsigned(u_int32_t, i);
        return 0;
}

static void
print_sin_addr(struct sockaddr_in *sin)
{

        print_in_addr(sin->sin_addr);
}

static void
print_in_addr(struct in_addr addr)
{
        unsigned int ip;

        ip = ntohl(addr.s_addr);
        printf("%d.%d.%d.%d",
               ip >> 24, (ip >> 16) & 255, (ip >> 8) & 255, ip & 255);
}

static void
bootpc_compose_query(struct bootpc_ifcontext *ifctx, struct thread *td)
{
        unsigned char *vendp;
        unsigned char vendor_client[64];
        uint32_t leasetime;
        uint8_t vendor_client_len;

        ifctx->gotrootpath = 0;

        bzero((caddr_t) &ifctx->call, sizeof(ifctx->call));

        /* bootpc part */
        ifctx->call.op = BOOTP_REQUEST;         /* BOOTREQUEST */
        ifctx->call.htype = 1;                  /* 10mb ethernet */
        ifctx->call.hlen = ifctx->sdl->sdl_alen;/* Hardware address length */
        ifctx->call.hops = 0;
        if (bootpc_ifctx_isunresolved(ifctx) != 0)
                ifctx->xid++;
        ifctx->call.xid = txdr_unsigned(ifctx->xid);
        bcopy(LLADDR(ifctx->sdl), &ifctx->call.chaddr, ifctx->sdl->sdl_alen);

        vendp = ifctx->call.vend;
        *vendp++ = 99;          /* RFC1048 cookie */
        *vendp++ = 130;
        *vendp++ = 83;
        *vendp++ = 99;
        *vendp++ = TAG_MAXMSGSIZE;
        *vendp++ = 2;
        *vendp++ = (sizeof(struct bootp_packet) >> 8) & 255;
        *vendp++ = sizeof(struct bootp_packet) & 255;

        snprintf(vendor_client, sizeof(vendor_client), "%s:%s:%s",
                ostype, MACHINE, osrelease);
        vendor_client_len = strlen(vendor_client);
        *vendp++ = TAG_VENDOR_INDENTIFIER;
        *vendp++ = vendor_client_len;
        memcpy(vendp, vendor_client, vendor_client_len);
        vendp += vendor_client_len;
        ifctx->dhcpquerytype = DHCP_NOMSG;
        switch (ifctx->state) {
        case IF_DHCP_UNRESOLVED:
                *vendp++ = TAG_DHCP_MSGTYPE;
                *vendp++ = 1;
                *vendp++ = DHCP_DISCOVER;
                ifctx->dhcpquerytype = DHCP_DISCOVER;
                ifctx->gotdhcpserver = 0;
                break;
        case IF_DHCP_OFFERED:
                *vendp++ = TAG_DHCP_MSGTYPE;
                *vendp++ = 1;
                *vendp++ = DHCP_REQUEST;
                ifctx->dhcpquerytype = DHCP_REQUEST;
                *vendp++ = TAG_DHCP_REQ_ADDR;
                *vendp++ = 4;
                memcpy(vendp, &ifctx->reply.yiaddr, 4);
                vendp += 4;
                if (ifctx->gotdhcpserver != 0) {
                        *vendp++ = TAG_DHCP_SERVERID;
                        *vendp++ = 4;
                        memcpy(vendp, &ifctx->dhcpserver, 4);
                        vendp += 4;
                }
                *vendp++ = TAG_DHCP_LEASETIME;
                *vendp++ = 4;
                leasetime = htonl(300);
                memcpy(vendp, &leasetime, 4);
                vendp += 4;
                break;
        default:
                break;
        }
        *vendp = TAG_END;

        ifctx->call.secs = 0;
        ifctx->call.flags = htons(0x8000); /* We need a broadcast answer */
}

static int
bootpc_hascookie(struct bootp_packet *bp)
{

        return (bp->vend[0] == 99 && bp->vend[1] == 130 &&
                bp->vend[2] == 83 && bp->vend[3] == 99);
}

static void
bootpc_tag_helper(struct bootpc_tagcontext *tctx,
    unsigned char *start, int len, int tag)
{
        unsigned char *j;
        unsigned char *ej;
        unsigned char code;

        if (tctx->badtag != 0 || tctx->badopt != 0)
                return;

        j = start;
        ej = j + len;

        while (j < ej) {
                code = *j++;
                if (code == TAG_PAD)
                        continue;
                if (code == TAG_END)
                        return;
                if (j >= ej || j + *j + 1 > ej) {
                        tctx->badopt = 1;
                        return;
                }
                len = *j++;
                if (code == tag) {
                        if (tctx->taglen + len > TAG_MAXLEN) {
                                tctx->badtag = 1;
                                return;
                        }
                        tctx->foundopt = 1;
                        if (len > 0)
                                memcpy(tctx->buf + tctx->taglen,
                                       j, len);
                        tctx->taglen += len;
                }
                if (code == TAG_OVERLOAD)
                        tctx->overload = *j;

                j += len;
        }
}

static unsigned char *
bootpc_tag(struct bootpc_tagcontext *tctx,
    struct bootp_packet *bp, int len, int tag)
{
        tctx->overload = 0;
        tctx->badopt = 0;
        tctx->badtag = 0;
        tctx->foundopt = 0;
        tctx->taglen = 0;

        if (bootpc_hascookie(bp) == 0)
                return NULL;

        bootpc_tag_helper(tctx, &bp->vend[4],
                          (unsigned char *) bp + len - &bp->vend[4], tag);

        if ((tctx->overload & OVERLOAD_FILE) != 0)
                bootpc_tag_helper(tctx,
                                  (unsigned char *) bp->file,
                                  sizeof(bp->file),
                                  tag);
        if ((tctx->overload & OVERLOAD_SNAME) != 0)
                bootpc_tag_helper(tctx,
                                  (unsigned char *) bp->sname,
                                  sizeof(bp->sname),
                                  tag);

        if (tctx->badopt != 0 || tctx->badtag != 0 || tctx->foundopt == 0)
                return NULL;
        tctx->buf[tctx->taglen] = '\0';
        return tctx->buf;
}

static void
bootpc_decode_reply(struct nfsv3_diskless *nd, struct bootpc_ifcontext *ifctx,
    struct bootpc_globalcontext *gctx)
{
        char *p, *s;

        ifctx->gotgw = 0;
        ifctx->gotnetmask = 0;

        clear_sinaddr(&ifctx->myaddr);
        clear_sinaddr(&ifctx->netmask);
        clear_sinaddr(&ifctx->gw);

        ifctx->myaddr.sin_addr = ifctx->reply.yiaddr;

        printf("%s at ", ifctx->ireq.ifr_name);
        print_sin_addr(&ifctx->myaddr);
        printf(" server ");
        print_in_addr(ifctx->reply.siaddr);

        ifctx->gw.sin_addr = ifctx->reply.giaddr;
        if (ifctx->reply.giaddr.s_addr != htonl(INADDR_ANY)) {
                printf(" via gateway ");
                print_in_addr(ifctx->reply.giaddr);
        }

        /* This call used for the side effect (overload flag) */
        (void) bootpc_tag(&gctx->tmptag,
                          &ifctx->reply, ifctx->replylen, TAG_END);

        if ((gctx->tmptag.overload & OVERLOAD_SNAME) == 0)
                if (ifctx->reply.sname[0] != '\0')
                        printf(" server name %s", ifctx->reply.sname);
        if ((gctx->tmptag.overload & OVERLOAD_FILE) == 0)
                if (ifctx->reply.file[0] != '\0')
                        printf(" boot file %s", ifctx->reply.file);

        printf("\n");

        p = bootpc_tag(&gctx->tag, &ifctx->reply, ifctx->replylen,
                       TAG_SUBNETMASK);
        if (p != NULL) {
                if (gctx->tag.taglen != 4)
                        panic("bootpc: subnet mask len is %d",
                              gctx->tag.taglen);
                bcopy(p, &ifctx->netmask.sin_addr, 4);
                ifctx->gotnetmask = 1;
                printf("subnet mask ");
                print_sin_addr(&ifctx->netmask);
                printf(" ");
        }

        p = bootpc_tag(&gctx->tag, &ifctx->reply, ifctx->replylen,
                       TAG_ROUTERS);
        if (p != NULL) {
                /* Routers */
                if (gctx->tag.taglen % 4)
                        panic("bootpc: Router Len is %d", gctx->tag.taglen);
                if (gctx->tag.taglen > 0) {
                        bcopy(p, &ifctx->gw.sin_addr, 4);
                        printf("router ");
                        print_sin_addr(&ifctx->gw);
                        printf(" ");
                        ifctx->gotgw = 1;
                        gctx->gotgw = 1;
                }
        }

        /*
         * Choose a root filesystem.  If a value is forced in the environment
         * and it contains "nfs:", use it unconditionally.  Otherwise, if the
         * kernel is compiled with the ROOTDEVNAME option, then use it if:
         *  - The server doesn't provide a pathname.
         *  - The boothowto flags include RB_DFLTROOT (user said to override
         *    the server value).
         */
        p = NULL;
        if ((s = kern_getenv("vfs.root.mountfrom")) != NULL) {
                if ((p = strstr(s, "nfs:")) != NULL)
                        p = strdup(p + 4, M_TEMP);
                freeenv(s);
        }
        if (p == NULL) {
                p = bootpc_tag(&gctx->tag, &ifctx->reply, ifctx->replylen,
                       TAG_ROOT);
                if (p != NULL)
                        ifctx->gotrootpath = 1;
        }
#ifdef ROOTDEVNAME
        if ((p == NULL || (boothowto & RB_DFLTROOT) != 0) && 
            (p = strstr(ROOTDEVNAME, "nfs:")) != NULL) {
                p += 4;
        }
#endif
        if (p != NULL) {
                if (gctx->setrootfs != NULL) {
                        printf("rootfs %s (ignored) ", p);
                } else  if (setfs(&nd->root_saddr,
                                  nd->root_hostnam, p, &ifctx->reply.siaddr)) {
                        if (*p == '/') {
                                printf("root_server ");
                                print_sin_addr(&nd->root_saddr);
                                printf(" ");
                        }
                        printf("rootfs %s ", p);
                        gctx->gotrootpath = 1;
                        gctx->setrootfs = ifctx;

                        p = bootpc_tag(&gctx->tag, &ifctx->reply,
                                       ifctx->replylen,
                                       TAG_ROOTOPTS);
                        if (p != NULL) {
                                mountopts(&nd->root_args, p);
                                printf("rootopts %s ", p);
                        }
                } else
                        panic("Failed to set rootfs to %s", p);
        }

        p = bootpc_tag(&gctx->tag, &ifctx->reply, ifctx->replylen,
                       TAG_HOSTNAME);
        if (p != NULL) {
                if (gctx->tag.taglen >= MAXHOSTNAMELEN)
                        panic("bootpc: hostname >= %d bytes",
                              MAXHOSTNAMELEN);
                if (gctx->sethostname != NULL) {
                        printf("hostname %s (ignored) ", p);
                } else {
                        strcpy(nd->my_hostnam, p);
                        mtx_lock(&prison0.pr_mtx);
                        strcpy(prison0.pr_hostname, p);
                        mtx_unlock(&prison0.pr_mtx);
                        printf("hostname %s ", p);
                        gctx->sethostname = ifctx;
                }
        }
        p = bootpc_tag(&gctx->tag, &ifctx->reply, ifctx->replylen,
                        TAG_COOKIE);
        if (p != NULL) {        /* store in a sysctl variable */
                int i, l = sizeof(bootp_cookie) - 1;
                for (i = 0; i < l && p[i] != '\0'; i++)
                        bootp_cookie[i] = p[i];
                p[i] = '\0';
        }

        p = bootpc_tag(&gctx->tag, &ifctx->reply, ifctx->replylen,
                       TAG_INTF_MTU);
        if (p != NULL) {
                ifctx->mtu = be16dec(p);
        }

        printf("\n");

        if (ifctx->gotnetmask == 0) {
                /*
                 * If there is no netmask, use historical default,
                 * but we really need the right mask from the server.
                 */
                printf("%s: no netmask received!\n", ifctx->ireq.ifr_name);
                if (IN_CLASSA(ntohl(ifctx->myaddr.sin_addr.s_addr)))
                        ifctx->netmask.sin_addr.s_addr = htonl(IN_CLASSA_NET);
                else if (IN_CLASSB(ntohl(ifctx->myaddr.sin_addr.s_addr)))
                        ifctx->netmask.sin_addr.s_addr = htonl(IN_CLASSB_NET);
                else
                        ifctx->netmask.sin_addr.s_addr = htonl(IN_CLASSC_NET);
        }
}

static u_int
bootpc_init_ifa_cb(void *arg, struct ifaddr *ifa, u_int count)
{
        struct sockaddr_dl *sdl = (struct sockaddr_dl *)ifa->ifa_addr;

        if (count != 0)
                return (0);

        if (sdl->sdl_type != IFT_ETHER)
                return (0);

        *(struct sockaddr_dl **)arg = sdl;

        return (1);
}

void
bootpc_init(void)
{
        struct epoch_tracker et;
        struct bootpc_ifcontext *ifctx = NULL;  /* Interface BOOTP contexts */
        struct bootpc_globalcontext *gctx;      /* Global BOOTP context */
        struct sockaddr_dl *sdl;
        struct if_iter iter;
        if_t ifp;
        int error;
#ifndef BOOTP_WIRED_TO
        int ifcnt;
#endif
        struct nfsv3_diskless *nd;
        struct thread *td;
        int timeout;
        int delay;
        char *s;

        timeout = BOOTP_IFACE_WAIT_TIMEOUT * hz;
        delay = hz / 10;

        nd = &nfsv3_diskless;
        td = curthread;

        /*
         * If already filled in, don't touch it here
         */
        if (nfs_diskless_valid != 0)
                return;

        /*
         * If "vfs.root.mountfrom" is set and the value is something other
         * than "nfs:", it means the user doesn't want to mount root via nfs,
         * there's no reason to continue with bootpc
         */
        if ((s = kern_getenv("vfs.root.mountfrom")) != NULL) {
                if ((strncmp(s, "nfs:", 4)) != 0) {
                        printf("%s: vfs.root.mountfrom set to %s. "
                               "BOOTP aborted.\n", __func__, s);
                        freeenv(s);
                        return;
                }
                freeenv(s);
        }

        gctx = malloc(sizeof(*gctx), M_TEMP, M_WAITOK | M_ZERO);
        STAILQ_INIT(&gctx->interfaces);
        gctx->xid = ~0xFFFF;
        gctx->starttime = time_second;

        /*
         * If ROOTDEVNAME is defined or vfs.root.mountfrom is set then we have
         * root-path overrides that can potentially let us boot even if we don't
         * get a root path from the server, so we can treat that as a non-error.
         */
#ifdef ROOTDEVNAME
        gctx->any_root_overrides = 1;
#else
        gctx->any_root_overrides = testenv("vfs.root.mountfrom");
#endif

        /*
         * Find a network interface.
         */
        CURVNET_SET(TD_TO_VNET(td));
#ifdef BOOTP_WIRED_TO
        printf("%s: wired to interface '%s'\n", __func__, 
               __XSTRING(BOOTP_WIRED_TO));
        allocifctx(gctx);
#else
        /*
         * Preallocate interface context storage, if another interface
         * attaches and wins the race, it won't be eligible for bootp.
         */
        ifcnt = 0;
        NET_EPOCH_ENTER(et);
        for (if_t ifp = if_iter_start(&iter); ifp != NULL; ifp = if_iter_next(&iter)) {
                if ((if_getflags(ifp) &
                    (IFF_LOOPBACK | IFF_POINTOPOINT | IFF_BROADCAST)) ==
                    IFF_BROADCAST)
                        ifcnt++;
        }
        if_iter_finish(&iter);
        NET_EPOCH_EXIT(et);
        if (ifcnt == 0) {
                printf("WARNING: BOOTP found no eligible network interfaces, skipping!\n");
                goto out;
        }

        for (; ifcnt > 0; ifcnt--)
                allocifctx(gctx);
#endif

retry:
        ifctx = STAILQ_FIRST(&gctx->interfaces);
        NET_EPOCH_ENTER(et);
        for (ifp = if_iter_start(&iter); ifp != NULL; ifp = if_iter_next(&iter)) {
                if (ifctx == NULL)
                        break;
#ifdef BOOTP_WIRED_TO
                if (strcmp(if_name(ifp), __XSTRING(BOOTP_WIRED_TO)) != 0)
                        continue;
#else
                if ((if_getflags(ifp) &
                     (IFF_LOOPBACK | IFF_POINTOPOINT | IFF_BROADCAST)) !=
                    IFF_BROADCAST)
                        break;
                switch (if_getalloctype(ifp)) {
                        case IFT_ETHER:
                                break;
                        default:
                                continue;
                }
#endif
                strlcpy(ifctx->ireq.ifr_name, if_name(ifp),
                    sizeof(ifctx->ireq.ifr_name));
                ifctx->ifp = ifp;

                /* Get HW address */
                sdl = NULL;
                if_foreach_addr_type(ifp, AF_LINK, bootpc_init_ifa_cb, &sdl);
                if (sdl == NULL)
                        panic("bootpc: Unable to find HW address for %s",
                            ifctx->ireq.ifr_name);
                ifctx->sdl = sdl;

                ifctx = STAILQ_NEXT(ifctx, next);
        }
        if_iter_finish(&iter);
        NET_EPOCH_EXIT(et);
        CURVNET_RESTORE();

        if (STAILQ_EMPTY(&gctx->interfaces) ||
            STAILQ_FIRST(&gctx->interfaces)->ifp == NULL) {
                if (timeout > 0) {
                        pause("bootpc", delay);
                        timeout -= delay;
                        goto retry;
                }
#ifdef BOOTP_WIRED_TO
                panic("%s: Could not find interface specified "
                      "by BOOTP_WIRED_TO: "
                      __XSTRING(BOOTP_WIRED_TO), __func__);
#else
                panic("%s: no suitable interface", __func__);
#endif
        }

        error = socreate(AF_INET, &bootp_so, SOCK_DGRAM, 0, td->td_ucred, td);
        if (error != 0)
                panic("%s: socreate, error=%d", __func__, error);

        STAILQ_FOREACH(ifctx, &gctx->interfaces, next)
                bootpc_fakeup_interface(ifctx, td);

        STAILQ_FOREACH(ifctx, &gctx->interfaces, next)
                bootpc_compose_query(ifctx, td);

        error = bootpc_call(gctx, td);
        if (error != 0) {
                printf("BOOTP call failed\n");
        }

        mountopts(&nd->root_args, NULL);

        STAILQ_FOREACH(ifctx, &gctx->interfaces, next)
                if (bootpc_ifctx_isresolved(ifctx) != 0)
                        bootpc_decode_reply(nd, ifctx, gctx);

#ifdef BOOTP_NFSROOT
        if (gctx->gotrootpath == 0 && gctx->any_root_overrides == 0)
                panic("bootpc: No root path offered");
#endif

        STAILQ_FOREACH(ifctx, &gctx->interfaces, next)
                bootpc_adjust_interface(ifctx, gctx, td);

        soclose(bootp_so);

        STAILQ_FOREACH(ifctx, &gctx->interfaces, next)
                if (ifctx->gotrootpath != 0)
                        break;
        if (ifctx == NULL) {
                STAILQ_FOREACH(ifctx, &gctx->interfaces, next)
                        if (bootpc_ifctx_isresolved(ifctx) != 0)
                                break;
        }
        if (ifctx == NULL)
                goto out;

        if (gctx->gotrootpath != 0) {
                struct epoch_tracker et;

                kern_setenv("boot.netif.name", if_name(ifctx->ifp));

                NET_EPOCH_ENTER(et);
                bootpc_add_default_route(ifctx);
                NET_EPOCH_EXIT(et);
                error = md_mount(&nd->root_saddr, nd->root_hostnam,
                                 nd->root_fh, &nd->root_fhsize,
                                 &nd->root_args, td);
                NET_EPOCH_ENTER(et);
                bootpc_remove_default_route(ifctx);
                NET_EPOCH_EXIT(et);
                if (error != 0) {
                        if (gctx->any_root_overrides == 0)
                                panic("nfs_boot: mount root, error=%d", error);
                        else
                                goto out;
                }
                rootdevnames[0] = "nfs:";
                nfs_diskless_valid = 3;
        }

        strcpy(nd->myif.ifra_name, ifctx->ireq.ifr_name);
        bcopy(&ifctx->myaddr, &nd->myif.ifra_addr, sizeof(ifctx->myaddr));
        bcopy(&ifctx->myaddr, &nd->myif.ifra_broadaddr, sizeof(ifctx->myaddr));
        ((struct sockaddr_in *) &nd->myif.ifra_broadaddr)->sin_addr.s_addr =
                ifctx->myaddr.sin_addr.s_addr |
                ~ ifctx->netmask.sin_addr.s_addr;
        bcopy(&ifctx->netmask, &nd->myif.ifra_mask, sizeof(ifctx->netmask));
        bcopy(&ifctx->gw, &nd->mygateway, sizeof(ifctx->gw));

out:
        while((ifctx = STAILQ_FIRST(&gctx->interfaces)) != NULL) {
                STAILQ_REMOVE_HEAD(&gctx->interfaces, next);
                free(ifctx, M_TEMP);
        }
        free(gctx, M_TEMP);
}

/*
 * RPC: mountd/mount
 * Given a server pathname, get an NFS file handle.
 * Also, sets sin->sin_port to the NFS service port.
 */
static int
md_mount(struct sockaddr_in *mdsin, char *path, u_char *fhp, int *fhsizep,
    struct nfs_args *args, struct thread *td)
{
        struct mbuf *m;
        int error;
        int authunixok;
        int authcount;
        int authver;

#define RPCPROG_MNT     100005
#define RPCMNT_VER1     1
#define RPCMNT_VER3     3
#define RPCMNT_MOUNT    1
#define AUTH_SYS        1               /* unix style (uid, gids) */
#define AUTH_UNIX       AUTH_SYS

        /* XXX honor v2/v3 flags in args->flags? */
#ifdef BOOTP_NFSV3
        /* First try NFS v3 */
        /* Get port number for MOUNTD. */
        error = krpc_portmap(mdsin, RPCPROG_MNT, RPCMNT_VER3,
                             &mdsin->sin_port, td);
        if (error == 0) {
                m = xdr_string_encode(path, strlen(path));

                /* Do RPC to mountd. */
                error = krpc_call(mdsin, RPCPROG_MNT, RPCMNT_VER3,
                                  RPCMNT_MOUNT, &m, NULL, td);
        }
        if (error == 0) {
                args->flags |= NFSMNT_NFSV3;
        } else {
#endif
                /* Fallback to NFS v2 */

                /* Get port number for MOUNTD. */
                error = krpc_portmap(mdsin, RPCPROG_MNT, RPCMNT_VER1,
                                     &mdsin->sin_port, td);
                if (error != 0)
                        return error;

                m = xdr_string_encode(path, strlen(path));

                /* Do RPC to mountd. */
                error = krpc_call(mdsin, RPCPROG_MNT, RPCMNT_VER1,
                                  RPCMNT_MOUNT, &m, NULL, td);
                if (error != 0)
                        return error;   /* message already freed */

#ifdef BOOTP_NFSV3
        }
#endif

        if (xdr_int_decode(&m, &error) != 0 || error != 0)
                goto bad;

        if ((args->flags & NFSMNT_NFSV3) != 0) {
                if (xdr_int_decode(&m, fhsizep) != 0 ||
                    *fhsizep > NFSX_V3FHMAX ||
                    *fhsizep <= 0)
                        goto bad;
        } else
                *fhsizep = NFSX_V2FH;

        if (xdr_opaque_decode(&m, fhp, *fhsizep) != 0)
                goto bad;

        if (args->flags & NFSMNT_NFSV3) {
                if (xdr_int_decode(&m, &authcount) != 0)
                        goto bad;
                authunixok = 0;
                if (authcount < 0 || authcount > 100)
                        goto bad;
                while (authcount > 0) {
                        if (xdr_int_decode(&m, &authver) != 0)
                                goto bad;
                        if (authver == AUTH_UNIX)
                                authunixok = 1;
                        authcount--;
                }
                if (authunixok == 0)
                        goto bad;
        }

        /* Set port number for NFS use. */
        error = krpc_portmap(mdsin, NFS_PROG,
                             (args->flags &
                              NFSMNT_NFSV3) ? NFS_VER3 : NFS_VER2,
                             &mdsin->sin_port, td);

        goto out;

bad:
        error = EBADRPC;

out:
        m_freem(m);
        return error;
}

SYSINIT(bootp_rootconf, SI_SUB_ROOT_CONF, SI_ORDER_FIRST, bootpc_init, NULL);