xref: /freebsd/sys/nfs/bootp_subr.c (revision 685dc743dc3b5645e34836464128e1c0558b404b)

/*-
 * 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);