xref: /dragonfly/sys/vfs/nfs/bootp_subr.c (revision b7367ef6)
1 /*
2  * Copyright (c) 1995 Gordon Ross, Adam Glass
3  * Copyright (c) 1992 Regents of the University of California.
4  * All rights reserved.
5  *
6  * This software was developed by the Computer Systems Engineering group
7  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
8  * contributed to Berkeley.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the University of
21  *	California, Lawrence Berkeley Laboratory and its contributors.
22  * 4. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  *
38  * nfs/krpc_subr.c
39  * $NetBSD: krpc_subr.c,v 1.10 1995/08/08 20:43:43 gwr Exp $
40  * $FreeBSD: src/sys/nfs/bootp_subr.c,v 1.20.2.9 2003/04/24 16:51:08 ambrisko Exp $
41  * $DragonFly: src/sys/vfs/nfs/bootp_subr.c,v 1.22 2006/12/23 00:41:29 swildner Exp $
42  */
43 
44 #include "opt_bootp.h"
45 
46 #include <sys/param.h>
47 #include <sys/systm.h>
48 #include <sys/kernel.h>
49 #include <sys/sockio.h>
50 #include <sys/proc.h>
51 #include <sys/malloc.h>
52 #include <sys/mount.h>
53 #include <sys/mbuf.h>
54 #include <sys/socket.h>
55 #include <sys/socketvar.h>
56 #include <sys/sysctl.h>
57 #include <sys/uio.h>
58 #include <sys/fcntl.h>
59 
60 #include <net/if.h>
61 #include <net/route.h>
62 
63 #include <netinet/in.h>
64 #include <net/if_types.h>
65 #include <net/if_dl.h>
66 
67 #include "rpcv2.h"
68 #include "nfsproto.h"
69 #include "nfs.h"
70 #include "nfsdiskless.h"
71 #include "krpc.h"
72 #include "xdr_subs.h"
73 #include "nfsmountrpc.h"
74 
75 #define BOOTP_MIN_LEN		300	/* Minimum size of bootp udp packet */
76 
77 #ifndef BOOTP_SETTLE_DELAY
78 #define BOOTP_SETTLE_DELAY 3
79 #endif
80 
81 /*
82  * What is the longest we will wait before re-sending a request?
83  * Note this is also the frequency of "RPC timeout" messages.
84  * The re-send loop count sup linearly to this maximum, so the
85  * first complaint will happen after (1+2+3+4+5)=15 seconds.
86  */
87 #define	MAX_RESEND_DELAY 5	/* seconds */
88 
89 /* Definitions from RFC951 */
90 struct bootp_packet {
91 	u_int8_t op;
92 	u_int8_t htype;
93 	u_int8_t hlen;
94 	u_int8_t hops;
95 	u_int32_t xid;
96 	u_int16_t secs;
97 	u_int16_t flags;
98 	struct in_addr ciaddr;
99 	struct in_addr yiaddr;
100 	struct in_addr siaddr;
101 	struct in_addr giaddr;
102 	unsigned char chaddr[16];
103 	char sname[64];
104 	char file[128];
105 	unsigned char vend[1222];
106 };
107 
108 struct bootpc_ifcontext {
109 	struct bootpc_ifcontext *next;
110 	struct bootp_packet call;
111 	struct bootp_packet reply;
112 	int replylen;
113 	int overload;
114 	struct socket *so;
115 	struct ifreq ireq;
116 	struct ifnet *ifp;
117 	struct sockaddr_dl *sdl;
118 	struct sockaddr_in myaddr;
119 	struct sockaddr_in netmask;
120 	struct sockaddr_in gw;
121 	struct sockaddr_in broadcast;	/* Different for each interface */
122 	int gotgw;
123 	int gotnetmask;
124 	int gotrootpath;
125 	int outstanding;
126 	int sentmsg;
127 	u_int32_t xid;
128 	enum {
129 		IF_BOOTP_UNRESOLVED,
130 		IF_BOOTP_RESOLVED,
131 		IF_BOOTP_FAILED,
132 		IF_DHCP_UNRESOLVED,
133 		IF_DHCP_OFFERED,
134 		IF_DHCP_RESOLVED,
135 		IF_DHCP_FAILED,
136 	} state;
137 	int dhcpquerytype;		/* dhcp type sent */
138 	struct in_addr dhcpserver;
139 	int gotdhcpserver;
140 };
141 
142 #define TAG_MAXLEN 1024
143 struct bootpc_tagcontext {
144 	char buf[TAG_MAXLEN + 1];
145 	int overload;
146 	int badopt;
147 	int badtag;
148 	int foundopt;
149 	int taglen;
150 };
151 
152 struct bootpc_globalcontext {
153 	struct bootpc_ifcontext *interfaces;
154 	struct bootpc_ifcontext *lastinterface;
155 	u_int32_t xid;
156 	int gotrootpath;
157 	int gotswappath;
158 	int gotgw;
159 	int ifnum;
160 	int secs;
161 	int starttime;
162 	struct bootp_packet reply;
163 	int replylen;
164 	struct bootpc_ifcontext *setswapfs;
165 	struct bootpc_ifcontext *setrootfs;
166 	struct bootpc_ifcontext *sethostname;
167 	char lookup_path[24];
168 	struct bootpc_tagcontext tmptag;
169 	struct bootpc_tagcontext tag;
170 };
171 
172 #define IPPORT_BOOTPC 68
173 #define IPPORT_BOOTPS 67
174 
175 #define BOOTP_REQUEST 1
176 #define BOOTP_REPLY 2
177 
178 /* Common tags */
179 #define TAG_PAD		  0  /* Pad option, implicit length 1 */
180 #define TAG_SUBNETMASK	  1  /* RFC 950 subnet mask */
181 #define TAG_ROUTERS	  3  /* Routers (in order of preference) */
182 #define TAG_HOSTNAME	 12  /* Client host name */
183 #define TAG_ROOT	 17  /* Root path */
184 
185 /* DHCP specific tags */
186 #define TAG_OVERLOAD	 52  /* Option Overload */
187 #define TAG_MAXMSGSIZE   57  /* Maximum DHCP Message Size */
188 
189 #define TAG_END		255  /* End Option (i.e. no more options) */
190 
191 /* Overload values */
192 #define OVERLOAD_FILE     1
193 #define OVERLOAD_SNAME    2
194 
195 /* Site specific tags: */
196 #define TAG_SWAP	128
197 #define TAG_SWAPSIZE	129
198 #define TAG_ROOTOPTS	130
199 #define TAG_SWAPOPTS	131
200 #define TAG_COOKIE	134	/* ascii info for userland, exported via sysctl */
201 
202 #define TAG_DHCP_MSGTYPE 53
203 #define TAG_DHCP_REQ_ADDR 50
204 #define TAG_DHCP_SERVERID 54
205 #define TAG_DHCP_LEASETIME 51
206 
207 #define TAG_VENDOR_INDENTIFIER 60
208 
209 #define DHCP_NOMSG    0
210 #define DHCP_DISCOVER 1
211 #define DHCP_OFFER    2
212 #define DHCP_REQUEST  3
213 #define DHCP_ACK      5
214 
215 extern struct nfsv3_diskless nfsv3_diskless;
216 static char bootp_cookie[128];
217 SYSCTL_STRING(_kern, OID_AUTO, bootp_cookie, CTLFLAG_RD,
218 	bootp_cookie, 0, "Cookie (T134) supplied by bootp server");
219 
220 /* mountd RPC */
221 static void print_in_addr(struct in_addr addr);
222 static void print_sin_addr(struct sockaddr_in *addr);
223 static void clear_sinaddr(struct sockaddr_in *sin);
224 static
225 struct bootpc_ifcontext *allocifctx(struct bootpc_globalcontext *gctx);
226 static void bootpc_compose_query(struct bootpc_ifcontext *ifctx,
227 				 struct bootpc_globalcontext *gctx,
228 				 struct thread *td);
229 static unsigned char *bootpc_tag(struct bootpc_tagcontext *tctx,
230 				 struct bootp_packet *bp, int len, int tag);
231 static void bootpc_tag_helper(struct bootpc_tagcontext *tctx,
232 			      unsigned char *start, int len, int tag);
233 
234 #ifdef BOOTP_DEBUG
235 void bootpboot_p_sa(struct sockaddr *sa,struct sockaddr *ma);
236 void bootpboot_p_ma(struct sockaddr *ma);
237 void bootpboot_p_rtentry(struct rtentry *rt);
238 void bootpboot_p_tree(struct radix_node *rn);
239 void bootpboot_p_rtlist(void);
240 void bootpboot_p_if(struct ifnet *ifp, struct ifaddr *ifa);
241 void bootpboot_p_iflist(void);
242 #endif
243 
244 static int  bootpc_call(struct bootpc_globalcontext *gctx,
245 			struct thread *td);
246 
247 static int bootpc_fakeup_interface(struct bootpc_ifcontext *ifctx,
248 				   struct bootpc_globalcontext *gctx,
249 				   struct thread *td);
250 
251 static int bootpc_adjust_interface(struct bootpc_ifcontext *ifctx,
252 				   struct bootpc_globalcontext *gctx,
253 				   struct thread *td);
254 
255 static void bootpc_decode_reply(struct nfsv3_diskless *nd,
256 				struct bootpc_ifcontext *ifctx,
257 				struct bootpc_globalcontext *gctx);
258 
259 static int bootpc_received(struct bootpc_globalcontext *gctx,
260 			   struct bootpc_ifcontext *ifctx);
261 
262 static __inline int bootpc_ifctx_isresolved(struct bootpc_ifcontext *ifctx);
263 static __inline int bootpc_ifctx_isunresolved(struct bootpc_ifcontext *ifctx);
264 static __inline int bootpc_ifctx_isfailed(struct bootpc_ifcontext *ifctx);
265 
266 void bootpc_init(void);
267 
268 /*
269  * In order to have multiple active interfaces with address 0.0.0.0
270  * and be able to send data to a selected interface, we perform
271  * some tricks:
272  *
273  *  - The 'broadcast' address is different for each interface.
274  *
275  *  - We temporarily add routing pointing 255.255.255.255 to the
276  *    selected interface broadcast address, thus the packet sent
277  *    goes to that interface.
278  */
279 
280 #ifdef BOOTP_DEBUG
281 void
282 bootpboot_p_sa(struct sockaddr *sa, struct sockaddr *ma)
283 {
284 	if (sa == NULL) {
285 		kprintf("(sockaddr *) <null>");
286 		return;
287 	}
288 	switch (sa->sa_family) {
289 	case AF_INET:
290 	{
291 		struct sockaddr_in *sin;
292 
293 		sin = (struct sockaddr_in *) sa;
294 		kprintf("inet ");
295 		print_sin_addr(sin);
296 		if (ma != NULL) {
297 			sin = (struct sockaddr_in *) ma;
298 			kprintf(" mask ");
299 			print_sin_addr(sin);
300 		}
301 	}
302 	break;
303 	case AF_LINK:
304 	{
305 		struct sockaddr_dl *sli;
306 		int i;
307 
308 		sli = (struct sockaddr_dl *) sa;
309 		kprintf("link %.*s ", sli->sdl_nlen, sli->sdl_data);
310 		for (i = 0; i < sli->sdl_alen; i++) {
311 			if (i > 0)
312 				kprintf(":");
313 			kprintf("%x", ((unsigned char *) LLADDR(sli))[i]);
314 		}
315 	}
316 	break;
317 	default:
318 		kprintf("af%d", sa->sa_family);
319 	}
320 }
321 
322 
323 void
324 bootpboot_p_ma(struct sockaddr *ma)
325 {
326 	if (ma == NULL) {
327 		kprintf("<null>");
328 		return;
329 	}
330 	kprintf("%x", *(int *)ma);
331 }
332 
333 
334 void
335 bootpboot_p_rtentry(struct rtentry *rt)
336 {
337 	bootpboot_p_sa(rt_key(rt), rt_mask(rt));
338 	kprintf(" ");
339 	bootpboot_p_ma(rt->rt_genmask);
340 	kprintf(" ");
341 	bootpboot_p_sa(rt->rt_gateway, NULL);
342 	kprintf(" ");
343 	kprintf("flags %x", (unsigned short) rt->rt_flags);
344 	kprintf(" %d", (int) rt->rt_rmx.rmx_expire);
345 	kprintf(" %s\n", if_name(rt->rt_ifp));
346 }
347 
348 
349 void
350 bootpboot_p_tree(struct radix_node *rn)
351 {
352 	while (rn != NULL) {
353 		if (rn->rn_bit < 0) {
354 			if ((rn->rn_flags & RNF_ROOT) != 0) {
355 			} else {
356 				bootpboot_p_rtentry((struct rtentry *) rn);
357 			}
358 			rn = rn->rn_dupedkey;
359 		} else {
360 			bootpboot_p_tree(rn->rn_left);
361 			bootpboot_p_tree(rn->rn_right);
362 			return;
363 		}
364 	}
365 }
366 
367 
368 void
369 bootpboot_p_rtlist(void)
370 {
371 	kprintf("Routing table:\n");
372 	bootpboot_p_tree(rt_tables[AF_INET]->rnh_treetop);
373 }
374 
375 
376 void
377 bootpboot_p_if(struct ifnet *ifp, struct ifaddr *ifa)
378 {
379 	kprintf("%s flags %x, addr ",
380 	       if_name(ifp),
381 	       (unsigned short) ifp->if_flags);
382 	print_sin_addr((struct sockaddr_in *) ifa->ifa_addr);
383 	kprintf(", broadcast ");
384 	print_sin_addr((struct sockaddr_in *) ifa->ifa_dstaddr);
385 	kprintf(", netmask ");
386 	print_sin_addr((struct sockaddr_in *) ifa->ifa_netmask);
387 	kprintf("\n");
388 }
389 
390 
391 void
392 bootpboot_p_iflist(void)
393 {
394 	struct ifnet *ifp;
395 	struct ifaddr *ifa;
396 
397 	kprintf("Interface list:\n");
398 	TAILQ_FOREACH(ifp, &ifnet, if_link) {
399 		TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
400 			if (ifa->ifa_addr->sa_family == AF_INET)
401 				bootpboot_p_if(ifp, ifa);
402 	}
403 }
404 #endif /* defined(BOOTP_DEBUG) */
405 
406 
407 static void
408 clear_sinaddr(struct sockaddr_in *sin)
409 {
410 	bzero(sin, sizeof(*sin));
411 	sin->sin_len = sizeof(*sin);
412 	sin->sin_family = AF_INET;
413 	sin->sin_addr.s_addr = INADDR_ANY; /* XXX: htonl(INAADDR_ANY) ? */
414 	sin->sin_port = 0;
415 }
416 
417 
418 static struct bootpc_ifcontext *
419 allocifctx(struct bootpc_globalcontext *gctx)
420 {
421 	struct bootpc_ifcontext *ifctx;
422 	ifctx = (struct bootpc_ifcontext *) kmalloc(sizeof(*ifctx),
423 						   M_TEMP, M_WAITOK);
424 	if (ifctx == NULL)
425 		panic("Failed to allocate bootp interface context structure");
426 
427 	bzero(ifctx, sizeof(*ifctx));
428 	ifctx->xid = gctx->xid;
429 #ifdef BOOTP_NO_DHCP
430 	ifctx->state = IF_BOOTP_UNRESOLVED;
431 #else
432 	ifctx->state = IF_DHCP_UNRESOLVED;
433 #endif
434 	gctx->xid += 0x100;
435 	return ifctx;
436 }
437 
438 
439 static __inline int
440 bootpc_ifctx_isresolved(struct bootpc_ifcontext *ifctx)
441 {
442 	if (ifctx->state == IF_BOOTP_RESOLVED ||
443 	    ifctx->state == IF_DHCP_RESOLVED)
444 		return 1;
445 	return 0;
446 }
447 
448 
449 static __inline int
450 bootpc_ifctx_isunresolved(struct bootpc_ifcontext *ifctx)
451 {
452 	if (ifctx->state == IF_BOOTP_UNRESOLVED ||
453 	    ifctx->state == IF_DHCP_UNRESOLVED)
454 		return 1;
455 	return 0;
456 }
457 
458 
459 static __inline int
460 bootpc_ifctx_isfailed(struct bootpc_ifcontext *ifctx)
461 {
462 	if (ifctx->state == IF_BOOTP_FAILED ||
463 	    ifctx->state == IF_DHCP_FAILED)
464 		return 1;
465 	return 0;
466 }
467 
468 
469 static int
470 bootpc_received(struct bootpc_globalcontext *gctx,
471 		struct bootpc_ifcontext *ifctx)
472 {
473 	unsigned char dhcpreplytype;
474 	char *p;
475 	/*
476 	 * Need timeout for fallback to less
477 	 * desirable alternative.
478 	 */
479 
480 
481 	/* This call used for the side effect (badopt flag) */
482 	(void) bootpc_tag(&gctx->tmptag, &gctx->reply,
483 			  gctx->replylen,
484 			  TAG_END);
485 
486 	/* If packet is invalid, ignore it */
487 	if (gctx->tmptag.badopt != 0)
488 		return 0;
489 
490 	p = bootpc_tag(&gctx->tmptag, &gctx->reply,
491 		       gctx->replylen, TAG_DHCP_MSGTYPE);
492 	if (p != NULL)
493 		dhcpreplytype = *p;
494 	else
495 		dhcpreplytype = DHCP_NOMSG;
496 
497 	switch (ifctx->dhcpquerytype) {
498 	case DHCP_DISCOVER:
499 		if (dhcpreplytype != DHCP_OFFER 	/* Normal DHCP offer */
500 #ifndef BOOTP_FORCE_DHCP
501 		    && dhcpreplytype != DHCP_NOMSG	/* Fallback to BOOTP */
502 #endif
503 			)
504 			return 0;
505 		break;
506 	case DHCP_REQUEST:
507 		if (dhcpreplytype != DHCP_ACK)
508 			return 0;
509 		/* fall through */
510 	case DHCP_NOMSG:
511 		break;
512 	}
513 
514 
515 	/* Ignore packet unless it gives us a root tag we didn't have */
516 
517 	if ((ifctx->state == IF_BOOTP_RESOLVED ||
518 	     (ifctx->dhcpquerytype == DHCP_DISCOVER &&
519 	      (ifctx->state == IF_DHCP_OFFERED ||
520 	       ifctx->state == IF_DHCP_RESOLVED))) &&
521 	    (bootpc_tag(&gctx->tmptag, &ifctx->reply,
522 			ifctx->replylen,
523 			TAG_ROOT) != NULL ||
524 	     bootpc_tag(&gctx->tmptag, &gctx->reply,
525 			gctx->replylen,
526 			TAG_ROOT) == NULL))
527 		return 0;
528 
529 	bcopy(&gctx->reply,
530 	      &ifctx->reply,
531 	      gctx->replylen);
532 	ifctx->replylen = gctx->replylen;
533 
534 	/* XXX: Only reset if 'perfect' response */
535 	if (ifctx->state == IF_BOOTP_UNRESOLVED)
536 		ifctx->state = IF_BOOTP_RESOLVED;
537 	else if (ifctx->state == IF_DHCP_UNRESOLVED &&
538 		 ifctx->dhcpquerytype == DHCP_DISCOVER) {
539 		if (dhcpreplytype == DHCP_OFFER)
540 			ifctx->state = IF_DHCP_OFFERED;
541 		else
542 			ifctx->state = IF_BOOTP_RESOLVED;	/* Fallback */
543 	} else if (ifctx->state == IF_DHCP_OFFERED &&
544 		   ifctx->dhcpquerytype == DHCP_REQUEST)
545 		ifctx->state = IF_DHCP_RESOLVED;
546 
547 
548 	if (ifctx->dhcpquerytype == DHCP_DISCOVER &&
549 	    ifctx->state != IF_BOOTP_RESOLVED) {
550 		p = bootpc_tag(&gctx->tmptag, &ifctx->reply,
551 			       ifctx->replylen, TAG_DHCP_SERVERID);
552 		if (p != NULL && gctx->tmptag.taglen == 4) {
553 			memcpy(&ifctx->dhcpserver, p, 4);
554 			ifctx->gotdhcpserver = 1;
555 		} else
556 			ifctx->gotdhcpserver = 0;
557 		return 1;
558 	}
559 
560 	ifctx->gotrootpath = (bootpc_tag(&gctx->tmptag, &ifctx->reply,
561 					 ifctx->replylen,
562 					 TAG_ROOT) != NULL);
563 	ifctx->gotgw = (bootpc_tag(&gctx->tmptag, &ifctx->reply,
564 				   ifctx->replylen,
565 				   TAG_ROUTERS) != NULL);
566 	ifctx->gotnetmask = (bootpc_tag(&gctx->tmptag, &ifctx->reply,
567 					ifctx->replylen,
568 					TAG_SUBNETMASK) != NULL);
569 	return 1;
570 }
571 
572 static int
573 bootpc_call(struct bootpc_globalcontext *gctx, struct thread *td)
574 {
575 	struct socket *so;
576 	struct sockaddr_in *sin, dst;
577 	struct uio auio;
578 	struct sockopt sopt;
579 	struct iovec aio;
580 	int error, on, rcvflg, timo, len;
581 	time_t atimo;
582 	time_t rtimo;
583 	struct timeval tv;
584 	struct bootpc_ifcontext *ifctx;
585 	int outstanding;
586 	int gotrootpath;
587 	int retry;
588 	const char *s;
589 
590 	/*
591 	 * Create socket and set its recieve timeout.
592 	 */
593 	error = socreate(AF_INET, &so, SOCK_DGRAM, 0, td);
594 	if (error != 0)
595 		goto out;
596 
597 	tv.tv_sec = 1;
598 	tv.tv_usec = 0;
599 	bzero(&sopt, sizeof(sopt));
600 	sopt.sopt_level = SOL_SOCKET;
601 	sopt.sopt_name = SO_RCVTIMEO;
602 	sopt.sopt_val = &tv;
603 	sopt.sopt_valsize = sizeof tv;
604 
605 	error = sosetopt(so, &sopt);
606 	if (error != 0)
607 		goto out;
608 
609 	/*
610 	 * Enable broadcast.
611 	 */
612 	on = 1;
613 	sopt.sopt_name = SO_BROADCAST;
614 	sopt.sopt_val = &on;
615 	sopt.sopt_valsize = sizeof on;
616 
617 	error = sosetopt(so, &sopt);
618 	if (error != 0)
619 		goto out;
620 
621 	/*
622 	 * Disable routing.
623 	 */
624 
625 	on = 1;
626 	sopt.sopt_name = SO_DONTROUTE;
627 	sopt.sopt_val = &on;
628 	sopt.sopt_valsize = sizeof on;
629 
630 	error = sosetopt(so, &sopt);
631 	if (error != 0)
632 		goto out;
633 
634 	/*
635 	 * Bind the local endpoint to a bootp client port.
636 	 */
637 	sin = &dst;
638 	clear_sinaddr(sin);
639 	sin->sin_port = htons(IPPORT_BOOTPC);
640 	error = sobind(so, (struct sockaddr *)sin, td);
641 	if (error != 0) {
642 		kprintf("bind failed\n");
643 		goto out;
644 	}
645 
646 	/*
647 	 * Setup socket address for the server.
648 	 */
649 	sin = &dst;
650 	clear_sinaddr(sin);
651 	sin->sin_addr.s_addr = INADDR_BROADCAST;
652 	sin->sin_port = htons(IPPORT_BOOTPS);
653 
654 	/*
655 	 * Send it, repeatedly, until a reply is received,
656 	 * but delay each re-send by an increasing amount.
657 	 * If the delay hits the maximum, start complaining.
658 	 */
659 	timo = 0;
660 	rtimo = 0;
661 	for (;;) {
662 
663 		outstanding = 0;
664 		gotrootpath = 0;
665 
666 		for (ifctx = gctx->interfaces;
667 		     ifctx != NULL;
668 		     ifctx = ifctx->next) {
669 			if (bootpc_ifctx_isresolved(ifctx) != 0 &&
670 			    bootpc_tag(&gctx->tmptag, &ifctx->reply,
671 				       ifctx->replylen,
672 				       TAG_ROOT) != NULL)
673 				gotrootpath = 1;
674 		}
675 
676 		for (ifctx = gctx->interfaces;
677 		     ifctx != NULL;
678 		     ifctx = ifctx->next) {
679 			ifctx->outstanding = 0;
680 			if (bootpc_ifctx_isresolved(ifctx)  != 0 &&
681 			    gotrootpath != 0) {
682 				continue;
683 			}
684 			if (bootpc_ifctx_isfailed(ifctx) != 0)
685 				continue;
686 
687 			outstanding++;
688 			ifctx->outstanding = 1;
689 
690 			/* Proceed to next step in DHCP negotiation */
691 			if ((ifctx->state == IF_DHCP_OFFERED &&
692 			     ifctx->dhcpquerytype != DHCP_REQUEST) ||
693 			    (ifctx->state == IF_DHCP_UNRESOLVED &&
694 			     ifctx->dhcpquerytype != DHCP_DISCOVER) ||
695 			    (ifctx->state == IF_BOOTP_UNRESOLVED &&
696 			     ifctx->dhcpquerytype != DHCP_NOMSG)) {
697 				ifctx->sentmsg = 0;
698 				bootpc_compose_query(ifctx, gctx, td);
699 			}
700 
701 			/* Send BOOTP request (or re-send). */
702 
703 			if (ifctx->sentmsg == 0) {
704 				switch(ifctx->dhcpquerytype) {
705 				case DHCP_DISCOVER:
706 					s = "DHCP Discover";
707 					break;
708 				case DHCP_REQUEST:
709 					s = "DHCP Request";
710 					break;
711 				case DHCP_NOMSG:
712 				default:
713 					s = "BOOTP Query";
714 					break;
715 				}
716 				kprintf("Sending %s packet from "
717 				       "interface %s (%*D)\n",
718 				       s,
719 				       ifctx->ireq.ifr_name,
720 				       ifctx->sdl->sdl_alen,
721 				       (unsigned char *) LLADDR(ifctx->sdl),
722 				       ":");
723 				ifctx->sentmsg = 1;
724 			}
725 
726 			aio.iov_base = (caddr_t) &ifctx->call;
727 			aio.iov_len = sizeof(ifctx->call);
728 
729 			auio.uio_iov = &aio;
730 			auio.uio_iovcnt = 1;
731 			auio.uio_segflg = UIO_SYSSPACE;
732 			auio.uio_rw = UIO_WRITE;
733 			auio.uio_offset = 0;
734 			auio.uio_resid = sizeof(ifctx->call);
735 			auio.uio_td = td;
736 
737 			/* Set netmask to 0.0.0.0 */
738 
739 			sin = (struct sockaddr_in *) &ifctx->ireq.ifr_addr;
740 			clear_sinaddr(sin);
741 			error = ifioctl(ifctx->so, SIOCSIFNETMASK,
742 					(caddr_t) &ifctx->ireq, proc0.p_ucred);
743 			if (error != 0)
744 				panic("bootpc_call:"
745 				      "set if netmask, error=%d",
746 				      error);
747 
748 			error = sosend(so, (struct sockaddr *) &dst,
749 				       &auio, NULL, NULL, 0, td);
750 			if (error != 0) {
751 				kprintf("bootpc_call: sosend: %d state %08x\n",
752 				       error, (int) so->so_state);
753 			}
754 
755 			/* XXX: Is this needed ? */
756 			tsleep(&error, 0, "bootpw", 10);
757 
758 			/* Set netmask to 255.0.0.0 */
759 
760 			sin = (struct sockaddr_in *) &ifctx->ireq.ifr_addr;
761 			clear_sinaddr(sin);
762 			sin->sin_addr.s_addr = htonl(0xff000000u);
763 			error = ifioctl(ifctx->so, SIOCSIFNETMASK,
764 					(caddr_t) &ifctx->ireq, proc0.p_ucred);
765 			if (error != 0)
766 				panic("bootpc_call:"
767 				      "set if netmask, error=%d",
768 				      error);
769 
770 		}
771 
772 		if (outstanding == 0 &&
773 		    (rtimo == 0 || time_second >= rtimo)) {
774 			error = 0;
775 			goto gotreply;
776 		}
777 
778 		/* Determine new timeout. */
779 		if (timo < MAX_RESEND_DELAY)
780 			timo++;
781 		else {
782 			kprintf("DHCP/BOOTP timeout for server ");
783 			print_sin_addr(&dst);
784 			kprintf("\n");
785 		}
786 
787 		/*
788 		 * Wait for up to timo seconds for a reply.
789 		 * The socket receive timeout was set to 1 second.
790 		 */
791 		atimo = timo + time_second;
792 		while (time_second < atimo) {
793 			aio.iov_base = (caddr_t) &gctx->reply;
794 			aio.iov_len = sizeof(gctx->reply);
795 
796 			auio.uio_iov = &aio;
797 			auio.uio_iovcnt = 1;
798 			auio.uio_segflg = UIO_SYSSPACE;
799 			auio.uio_rw = UIO_READ;
800 			auio.uio_offset = 0;
801 			auio.uio_resid = sizeof(gctx->reply);
802 			auio.uio_td = td;
803 
804 			rcvflg = 0;
805 			error = soreceive(so, NULL, &auio,
806 					  NULL, NULL, &rcvflg);
807 			gctx->secs = time_second - gctx->starttime;
808 			for (ifctx = gctx->interfaces;
809 			     ifctx != NULL;
810 			     ifctx = ifctx->next) {
811 				if (bootpc_ifctx_isresolved(ifctx) != 0 ||
812 				    bootpc_ifctx_isfailed(ifctx) != 0)
813 					continue;
814 
815 				ifctx->call.secs = htons(gctx->secs);
816 			}
817 			if (error == EWOULDBLOCK)
818 				continue;
819 			if (error != 0)
820 				goto out;
821 			len = sizeof(gctx->reply) - auio.uio_resid;
822 
823 			/* Do we have the required number of bytes ? */
824 			if (len < BOOTP_MIN_LEN)
825 				continue;
826 			gctx->replylen = len;
827 
828 			/* Is it a reply? */
829 			if (gctx->reply.op != BOOTP_REPLY)
830 				continue;
831 
832 			/* Is this an answer to our query */
833 			for (ifctx = gctx->interfaces;
834 			     ifctx != NULL;
835 			     ifctx = ifctx->next) {
836 				if (gctx->reply.xid != ifctx->call.xid)
837 					continue;
838 
839 				/* Same HW address size ? */
840 				if (gctx->reply.hlen != ifctx->call.hlen)
841 					continue;
842 
843 				/* Correct HW address ? */
844 				if (bcmp(gctx->reply.chaddr,
845 					 ifctx->call.chaddr,
846 					 ifctx->call.hlen) != 0)
847 					continue;
848 
849 				break;
850 			}
851 
852 			if (ifctx != NULL) {
853 				s =  bootpc_tag(&gctx->tmptag,
854 						&gctx->reply,
855 						gctx->replylen,
856 						TAG_DHCP_MSGTYPE);
857 				if (s != NULL) {
858 					switch (*s) {
859 					case DHCP_OFFER:
860 						s = "DHCP Offer";
861 						break;
862 					case DHCP_ACK:
863 						s = "DHCP Ack";
864 						break;
865 					default:
866 						s = "DHCP (unexpected)";
867 						break;
868 					}
869 				} else
870 					s = "BOOTP Reply";
871 
872 				kprintf("Received %s packet"
873 				       " on %s from ",
874 				       s,
875 				       ifctx->ireq.ifr_name);
876 				print_in_addr(gctx->reply.siaddr);
877 				if (gctx->reply.giaddr.s_addr !=
878 				    htonl(INADDR_ANY)) {
879 					kprintf(" via ");
880 					print_in_addr(gctx->reply.giaddr);
881 				}
882 				if (bootpc_received(gctx, ifctx) != 0) {
883 					kprintf(" (accepted)");
884 					if (ifctx->outstanding) {
885 						ifctx->outstanding = 0;
886 						outstanding--;
887 					}
888 					/* Network settle delay */
889 					if (outstanding == 0)
890 						atimo = time_second +
891 							BOOTP_SETTLE_DELAY;
892 				} else
893 					kprintf(" (ignored)");
894 				if (ifctx->gotrootpath) {
895 					gotrootpath = 1;
896 					rtimo = time_second +
897 						BOOTP_SETTLE_DELAY;
898 					kprintf(" (got root path)");
899 				} else
900 					kprintf(" (no root path)");
901 				kprintf("\n");
902 			}
903 		} /* while secs */
904 #ifdef BOOTP_TIMEOUT
905 		if (gctx->secs > BOOTP_TIMEOUT && BOOTP_TIMEOUT > 0)
906 			break;
907 #endif
908 		/* Force a retry if halfway in DHCP negotiation */
909 		retry = 0;
910 		for (ifctx = gctx->interfaces; ifctx != NULL;
911 		     ifctx = ifctx->next) {
912 			if (ifctx->state == IF_DHCP_OFFERED) {
913 				if (ifctx->dhcpquerytype == DHCP_DISCOVER)
914 					retry = 1;
915 				else
916 					ifctx->state = IF_DHCP_UNRESOLVED;
917 			}
918 		}
919 
920 		if (retry != 0)
921 			continue;
922 
923 		if (gotrootpath != 0) {
924 			gctx->gotrootpath = gotrootpath;
925 			if (rtimo != 0 && time_second >= rtimo)
926 				break;
927 		}
928 	} /* forever send/receive */
929 
930 	/*
931 	 * XXX: These are errors of varying seriousness being silently
932 	 * ignored
933 	 */
934 
935 	for (ifctx = gctx->interfaces; ifctx != NULL; ifctx = ifctx->next) {
936 		if (bootpc_ifctx_isresolved(ifctx) == 0) {
937 			kprintf("%s timeout for interface %s\n",
938 			       ifctx->dhcpquerytype != DHCP_NOMSG ?
939 			       "DHCP" : "BOOTP",
940 			       ifctx->ireq.ifr_name);
941 		}
942 	}
943 	if (gctx->gotrootpath != 0) {
944 #if 0
945 		kprintf("Got a root path, ignoring remaining timeout\n");
946 #endif
947 		error = 0;
948 		goto out;
949 	}
950 #ifndef BOOTP_NFSROOT
951 	for (ifctx = gctx->interfaces; ifctx != NULL; ifctx = ifctx->next) {
952 		if (bootpc_ifctx_isresolved(ifctx) != 0) {
953 			error = 0;
954 			goto out;
955 		}
956 	}
957 #endif
958 	error = ETIMEDOUT;
959 	goto out;
960 
961 gotreply:
962 out:
963 	soclose(so, FNONBLOCK);
964 	return error;
965 }
966 
967 
968 static int
969 bootpc_fakeup_interface(struct bootpc_ifcontext *ifctx,
970 			struct bootpc_globalcontext *gctx,
971 			struct thread *td)
972 {
973 	struct sockaddr_in *sin;
974 	int error;
975 
976 	struct ifreq *ireq;
977 	struct socket *so;
978 	struct ifaddr *ifa;
979 	struct sockaddr_dl *sdl;
980 
981 	error = socreate(AF_INET, &ifctx->so, SOCK_DGRAM, 0, td);
982 	if (error != 0)
983 		panic("nfs_boot: socreate, error=%d", error);
984 
985 	ireq = &ifctx->ireq;
986 	so = ifctx->so;
987 
988 	/*
989 	 * Bring up the interface.
990 	 *
991 	 * Get the old interface flags and or IFF_UP into them; if
992 	 * IFF_UP set blindly, interface selection can be clobbered.
993 	 */
994 	error = ifioctl(so, SIOCGIFFLAGS, (caddr_t)ireq, proc0.p_ucred);
995 	if (error != 0)
996 		panic("bootpc_fakeup_interface: GIFFLAGS, error=%d", error);
997 	ireq->ifr_flags |= IFF_UP;
998 	error = ifioctl(so, SIOCSIFFLAGS, (caddr_t)ireq, proc0.p_ucred);
999 	if (error != 0)
1000 		panic("bootpc_fakeup_interface: SIFFLAGS, error=%d", error);
1001 
1002 	/*
1003 	 * Do enough of ifconfig(8) so that the chosen interface
1004 	 * can talk to the servers.  (just set the address)
1005 	 */
1006 
1007 	/* addr is 0.0.0.0 */
1008 
1009 	sin = (struct sockaddr_in *) &ireq->ifr_addr;
1010 	clear_sinaddr(sin);
1011 	error = ifioctl(so, SIOCSIFADDR, (caddr_t) ireq, proc0.p_ucred);
1012 	if (error != 0 && (error != EEXIST || ifctx == gctx->interfaces))
1013 		panic("bootpc_fakeup_interface: "
1014 		      "set if addr, error=%d", error);
1015 
1016 	/* netmask is 255.0.0.0 */
1017 
1018 	sin = (struct sockaddr_in *) &ireq->ifr_addr;
1019 	clear_sinaddr(sin);
1020 	sin->sin_addr.s_addr = htonl(0xff000000u);
1021 	error = ifioctl(so, SIOCSIFNETMASK, (caddr_t)ireq, proc0.p_ucred);
1022 	if (error != 0)
1023 		panic("bootpc_fakeup_interface: set if netmask, error=%d",
1024 		      error);
1025 
1026 	/* Broadcast is 255.255.255.255 */
1027 
1028 	sin = (struct sockaddr_in *)&ireq->ifr_addr;
1029 	clear_sinaddr(sin);
1030 	clear_sinaddr(&ifctx->broadcast);
1031 	sin->sin_addr.s_addr = htonl(INADDR_BROADCAST);
1032 	ifctx->broadcast.sin_addr.s_addr = sin->sin_addr.s_addr;
1033 
1034 	error = ifioctl(so, SIOCSIFBRDADDR, (caddr_t)ireq, proc0.p_ucred);
1035 	if (error != 0 && error != EADDRNOTAVAIL)
1036 		panic("bootpc_fakeup_interface: "
1037 		      "set if broadcast addr, error=%d",
1038 		      error);
1039 	error = 0;
1040 
1041 	/* Get HW address */
1042 
1043 	sdl = NULL;
1044 	TAILQ_FOREACH(ifa, &ifctx->ifp->if_addrhead, ifa_link)
1045 		if (ifa->ifa_addr->sa_family == AF_LINK &&
1046 		    (sdl = ((struct sockaddr_dl *) ifa->ifa_addr)) != NULL &&
1047 		    sdl->sdl_type == IFT_ETHER)
1048 			break;
1049 
1050 	if (sdl == NULL)
1051 		panic("bootpc: Unable to find HW address for %s",
1052 		      ifctx->ireq.ifr_name);
1053 	ifctx->sdl = sdl;
1054 
1055 	return error;
1056 }
1057 
1058 
1059 static int
1060 bootpc_adjust_interface(struct bootpc_ifcontext *ifctx,
1061 			struct bootpc_globalcontext *gctx,
1062 			struct thread *td)
1063 {
1064 	int error;
1065 	struct sockaddr_in defdst;
1066 	struct sockaddr_in defmask;
1067 	struct sockaddr_in *sin;
1068 
1069 	struct ifreq *ireq;
1070 	struct socket *so;
1071 	struct sockaddr_in *myaddr;
1072 	struct sockaddr_in *netmask;
1073 	struct sockaddr_in *gw;
1074 
1075 	ireq = &ifctx->ireq;
1076 	so = ifctx->so;
1077 	myaddr = &ifctx->myaddr;
1078 	netmask = &ifctx->netmask;
1079 	gw = &ifctx->gw;
1080 
1081 	if (bootpc_ifctx_isresolved(ifctx) == 0) {
1082 
1083 		/* Shutdown interfaces where BOOTP failed */
1084 
1085 		kprintf("Shutdown interface %s\n", ifctx->ireq.ifr_name);
1086 		error = ifioctl(so, SIOCGIFFLAGS, (caddr_t)ireq, proc0.p_ucred);
1087 		if (error != 0)
1088 			panic("bootpc_adjust_interface: "
1089 			      "SIOCGIFFLAGS, error=%d", error);
1090 		ireq->ifr_flags &= ~IFF_UP;
1091 		error = ifioctl(so, SIOCSIFFLAGS, (caddr_t)ireq, proc0.p_ucred);
1092 		if (error != 0)
1093 			panic("bootpc_adjust_interface: "
1094 			      "SIOCSIFFLAGS, error=%d", error);
1095 
1096 		sin = (struct sockaddr_in *) &ireq->ifr_addr;
1097 		clear_sinaddr(sin);
1098 		error = ifioctl(so, SIOCDIFADDR, (caddr_t) ireq, proc0.p_ucred);
1099 		if (error != 0 && (error != EADDRNOTAVAIL ||
1100 				   ifctx == gctx->interfaces))
1101 			panic("bootpc_adjust_interface: "
1102 			      "SIOCDIFADDR, error=%d", error);
1103 
1104 		return 0;
1105 	}
1106 
1107 	kprintf("Adjusted interface %s\n", ifctx->ireq.ifr_name);
1108 	/*
1109 	 * Do enough of ifconfig(8) so that the chosen interface
1110 	 * can talk to the servers.  (just set the address)
1111 	 */
1112 	bcopy(netmask, &ireq->ifr_addr, sizeof(*netmask));
1113 	error = ifioctl(so, SIOCSIFNETMASK, (caddr_t) ireq, proc0.p_ucred);
1114 	if (error != 0)
1115 		panic("bootpc_adjust_interface: "
1116 		      "set if netmask, error=%d", error);
1117 
1118 	/* Broadcast is with host part of IP address all 1's */
1119 
1120 	sin = (struct sockaddr_in *) &ireq->ifr_addr;
1121 	clear_sinaddr(sin);
1122 	sin->sin_addr.s_addr = myaddr->sin_addr.s_addr |
1123 		~ netmask->sin_addr.s_addr;
1124 	error = ifioctl(so, SIOCSIFBRDADDR, (caddr_t) ireq, proc0.p_ucred);
1125 	if (error != 0)
1126 		panic("bootpc_adjust_interface: "
1127 		      "set if broadcast addr, error=%d", error);
1128 
1129 	bcopy(myaddr, &ireq->ifr_addr, sizeof(*myaddr));
1130 	error = ifioctl(so, SIOCSIFADDR, (caddr_t) ireq, proc0.p_ucred);
1131 	if (error != 0 && (error != EEXIST || ifctx == gctx->interfaces))
1132 		panic("bootpc_adjust_interface: "
1133 		      "set if addr, error=%d", error);
1134 
1135 	/* Add new default route */
1136 
1137 	if (ifctx->gotgw != 0 || gctx->gotgw == 0) {
1138 		clear_sinaddr(&defdst);
1139 		clear_sinaddr(&defmask);
1140 		error = rtrequest_global(RTM_ADD, (struct sockaddr *) &defdst,
1141 					 (struct sockaddr *) gw,
1142 					 (struct sockaddr *) &defmask,
1143 					 (RTF_UP | RTF_GATEWAY | RTF_STATIC));
1144 		if (error != 0) {
1145 			kprintf("bootpc_adjust_interface: "
1146 			       "add net route, error=%d\n", error);
1147 			return error;
1148 		}
1149 	}
1150 
1151 	return 0;
1152 }
1153 
1154 static void
1155 print_sin_addr(struct sockaddr_in *sin)
1156 {
1157 	print_in_addr(sin->sin_addr);
1158 }
1159 
1160 
1161 static void
1162 print_in_addr(struct in_addr addr)
1163 {
1164 	unsigned int ip;
1165 
1166 	ip = ntohl(addr.s_addr);
1167 	kprintf("%d.%d.%d.%d",
1168 	       ip >> 24, (ip >> 16) & 255, (ip >> 8) & 255, ip & 255);
1169 }
1170 
1171 static void
1172 bootpc_compose_query(struct bootpc_ifcontext *ifctx,
1173 		     struct bootpc_globalcontext *gctx, struct thread *td)
1174 {
1175 	unsigned char *vendp;
1176 	unsigned char vendor_client[64];
1177 	uint32_t leasetime;
1178 	uint8_t vendor_client_len;
1179 
1180 	ifctx->gotrootpath = 0;
1181 
1182 	bzero((caddr_t) &ifctx->call, sizeof(ifctx->call));
1183 
1184 	/* bootpc part */
1185 	ifctx->call.op = BOOTP_REQUEST; 	/* BOOTREQUEST */
1186 	ifctx->call.htype = 1;			/* 10mb ethernet */
1187 	ifctx->call.hlen = ifctx->sdl->sdl_alen;/* Hardware address length */
1188 	ifctx->call.hops = 0;
1189 	if (bootpc_ifctx_isunresolved(ifctx) != 0)
1190 		ifctx->xid++;
1191 	ifctx->call.xid = txdr_unsigned(ifctx->xid);
1192 	bcopy(LLADDR(ifctx->sdl), &ifctx->call.chaddr, ifctx->sdl->sdl_alen);
1193 
1194 	vendp = ifctx->call.vend;
1195 	*vendp++ = 99;		/* RFC1048 cookie */
1196 	*vendp++ = 130;
1197 	*vendp++ = 83;
1198 	*vendp++ = 99;
1199 	*vendp++ = TAG_MAXMSGSIZE;
1200 	*vendp++ = 2;
1201 	*vendp++ = (sizeof(struct bootp_packet) >> 8) & 255;
1202 	*vendp++ = sizeof(struct bootp_packet) & 255;
1203 
1204 	ksnprintf(vendor_client, sizeof(vendor_client), "%s:%s:%s",
1205 		ostype, MACHINE, osrelease);
1206 	vendor_client_len = strlen(vendor_client);
1207 	*vendp++ = TAG_VENDOR_INDENTIFIER;
1208 	*vendp++ = vendor_client_len;
1209 	memcpy(vendp, vendor_client, vendor_client_len);
1210 	vendp += vendor_client_len;
1211 	ifctx->dhcpquerytype = DHCP_NOMSG;
1212 	switch (ifctx->state) {
1213 	case IF_DHCP_UNRESOLVED:
1214 		*vendp++ = TAG_DHCP_MSGTYPE;
1215 		*vendp++ = 1;
1216 		*vendp++ = DHCP_DISCOVER;
1217 		ifctx->dhcpquerytype = DHCP_DISCOVER;
1218 		ifctx->gotdhcpserver = 0;
1219 		break;
1220 	case IF_DHCP_OFFERED:
1221 		*vendp++ = TAG_DHCP_MSGTYPE;
1222 		*vendp++ = 1;
1223 		*vendp++ = DHCP_REQUEST;
1224 		ifctx->dhcpquerytype = DHCP_REQUEST;
1225 		*vendp++ = TAG_DHCP_REQ_ADDR;
1226 		*vendp++ = 4;
1227 		memcpy(vendp, &ifctx->reply.yiaddr, 4);
1228 		vendp += 4;
1229 		if (ifctx->gotdhcpserver != 0) {
1230 			*vendp++ = TAG_DHCP_SERVERID;
1231 			*vendp++ = 4;
1232 			memcpy(vendp, &ifctx->dhcpserver, 4);
1233 			vendp += 4;
1234 		}
1235 		*vendp++ = TAG_DHCP_LEASETIME;
1236 		*vendp++ = 4;
1237 		leasetime = htonl(300);
1238 		memcpy(vendp, &leasetime, 4);
1239 		vendp += 4;
1240 	default:
1241 		;
1242 	}
1243 	*vendp = TAG_END;
1244 
1245 	ifctx->call.secs = 0;
1246 	ifctx->call.flags = htons(0x8000); /* We need an broadcast answer */
1247 }
1248 
1249 
1250 static int
1251 bootpc_hascookie(struct bootp_packet *bp)
1252 {
1253 	return (bp->vend[0] == 99 && bp->vend[1] == 130 &&
1254 		bp->vend[2] == 83 && bp->vend[3] == 99);
1255 }
1256 
1257 
1258 static void
1259 bootpc_tag_helper(struct bootpc_tagcontext *tctx,
1260 		  unsigned char *start, int len, int tag)
1261 {
1262 	unsigned char *j;
1263 	unsigned char *ej;
1264 	unsigned char code;
1265 
1266 	if (tctx->badtag != 0 || tctx->badopt != 0)
1267 		return;
1268 
1269 	j = start;
1270 	ej = j + len;
1271 
1272 	while (j < ej) {
1273 		code = *j++;
1274 		if (code == TAG_PAD)
1275 			continue;
1276 		if (code == TAG_END)
1277 			return;
1278 		if (j >= ej || j + *j + 1 > ej) {
1279 			tctx->badopt = 1;
1280 			return;
1281 		}
1282 		len = *j++;
1283 		if (code == tag) {
1284 			if (tctx->taglen + len > TAG_MAXLEN) {
1285 				tctx->badtag = 1;
1286 				return;
1287 			}
1288 			tctx->foundopt = 1;
1289 			if (len > 0)
1290 				memcpy(tctx->buf + tctx->taglen,
1291 				       j, len);
1292 			tctx->taglen += len;
1293 		}
1294 		if (code == TAG_OVERLOAD)
1295 			tctx->overload = *j;
1296 
1297 		j += len;
1298 	}
1299 }
1300 
1301 
1302 static unsigned char *
1303 bootpc_tag(struct bootpc_tagcontext *tctx, struct bootp_packet *bp,
1304 	   int len, int tag)
1305 {
1306 	unsigned char *j;
1307 	unsigned char *ej;
1308 
1309 	tctx->overload = 0;
1310 	tctx->badopt = 0;
1311 	tctx->badtag = 0;
1312 	tctx->foundopt = 0;
1313 	tctx->taglen = 0;
1314 
1315 	if (bootpc_hascookie(bp) == 0)
1316 		return NULL;
1317 
1318 	j = &bp->vend[4];
1319 	ej = (unsigned char *) bp + len;
1320 
1321 	bootpc_tag_helper(tctx, &bp->vend[4],
1322 			  (unsigned char *) bp + len - &bp->vend[4], tag);
1323 
1324 	if ((tctx->overload & OVERLOAD_FILE) != 0)
1325 		bootpc_tag_helper(tctx,
1326 				  (unsigned char *) bp->file,
1327 				  sizeof(bp->file),
1328 				  tag);
1329 	if ((tctx->overload & OVERLOAD_SNAME) != 0)
1330 		bootpc_tag_helper(tctx,
1331 				  (unsigned char *) bp->sname,
1332 				  sizeof(bp->sname),
1333 				  tag);
1334 
1335 	if (tctx->badopt != 0 || tctx->badtag != 0 || tctx->foundopt == 0)
1336 		return NULL;
1337 	tctx->buf[tctx->taglen] = '\0';
1338 	return tctx->buf;
1339 }
1340 
1341 
1342 static void
1343 bootpc_decode_reply(struct nfsv3_diskless *nd, struct bootpc_ifcontext *ifctx,
1344 		    struct bootpc_globalcontext *gctx)
1345 {
1346 	char *p;
1347 	unsigned int ip;
1348 
1349 	ifctx->gotgw = 0;
1350 	ifctx->gotnetmask = 0;
1351 
1352 	clear_sinaddr(&ifctx->myaddr);
1353 	clear_sinaddr(&ifctx->netmask);
1354 	clear_sinaddr(&ifctx->gw);
1355 
1356 	ifctx->myaddr.sin_addr = ifctx->reply.yiaddr;
1357 
1358 	ip = ntohl(ifctx->myaddr.sin_addr.s_addr);
1359 	ksnprintf(gctx->lookup_path, sizeof(gctx->lookup_path),
1360 		 "swap.%d.%d.%d.%d",
1361 		 ip >> 24, (ip >> 16) & 255, (ip >> 8) & 255, ip & 255);
1362 
1363 	kprintf("%s at ", ifctx->ireq.ifr_name);
1364 	print_sin_addr(&ifctx->myaddr);
1365 	kprintf(" server ");
1366 	print_in_addr(ifctx->reply.siaddr);
1367 
1368 	ifctx->gw.sin_addr = ifctx->reply.giaddr;
1369 	if (ifctx->reply.giaddr.s_addr != htonl(INADDR_ANY)) {
1370 		kprintf(" via gateway ");
1371 		print_in_addr(ifctx->reply.giaddr);
1372 	}
1373 
1374 	/* This call used for the side effect (overload flag) */
1375 	(void) bootpc_tag(&gctx->tmptag,
1376 			  &ifctx->reply, ifctx->replylen, TAG_END);
1377 
1378 	if ((gctx->tmptag.overload & OVERLOAD_SNAME) == 0)
1379 		if (ifctx->reply.sname[0] != '\0')
1380 			kprintf(" server name %s", ifctx->reply.sname);
1381 	if ((gctx->tmptag.overload & OVERLOAD_FILE) == 0)
1382 		if (ifctx->reply.file[0] != '\0')
1383 			kprintf(" boot file %s", ifctx->reply.file);
1384 
1385 	kprintf("\n");
1386 
1387 	p = bootpc_tag(&gctx->tag, &ifctx->reply, ifctx->replylen,
1388 		       TAG_SUBNETMASK);
1389 	if (p != NULL) {
1390 		if (gctx->tag.taglen != 4)
1391 			panic("bootpc: subnet mask len is %d",
1392 			      gctx->tag.taglen);
1393 		bcopy(p, &ifctx->netmask.sin_addr, 4);
1394 		ifctx->gotnetmask = 1;
1395 		kprintf("subnet mask ");
1396 		print_sin_addr(&ifctx->netmask);
1397 		kprintf(" ");
1398 	}
1399 
1400 	p = bootpc_tag(&gctx->tag, &ifctx->reply, ifctx->replylen,
1401 		       TAG_ROUTERS);
1402 	if (p != NULL) {
1403 		/* Routers */
1404 		if (gctx->tag.taglen % 4)
1405 			panic("bootpc: Router Len is %d", gctx->tag.taglen);
1406 		if (gctx->tag.taglen > 0) {
1407 			bcopy(p, &ifctx->gw.sin_addr, 4);
1408 			kprintf("router ");
1409 			print_sin_addr(&ifctx->gw);
1410 			kprintf(" ");
1411 			ifctx->gotgw = 1;
1412 			gctx->gotgw = 1;
1413 		}
1414 	}
1415 
1416 	p = bootpc_tag(&gctx->tag, &ifctx->reply, ifctx->replylen,
1417 		       TAG_ROOT);
1418 	if (p != NULL) {
1419 		if (gctx->setrootfs != NULL) {
1420 			kprintf("rootfs %s (ignored) ", p);
1421 		} else 	if (setfs(&nd->root_saddr,
1422 				  nd->root_hostnam, p)) {
1423 			kprintf("rootfs %s ",p);
1424 			gctx->gotrootpath = 1;
1425 			ifctx->gotrootpath = 1;
1426 			gctx->setrootfs = ifctx;
1427 
1428 			p = bootpc_tag(&gctx->tag, &ifctx->reply,
1429 				       ifctx->replylen,
1430 				       TAG_ROOTOPTS);
1431 			if (p != NULL) {
1432 				mountopts(&nd->root_args, p);
1433 				kprintf("rootopts %s ", p);
1434 			}
1435 		} else
1436 			panic("Failed to set rootfs to %s",p);
1437 	}
1438 
1439 	p = bootpc_tag(&gctx->tag, &ifctx->reply, ifctx->replylen,
1440 		       TAG_SWAP);
1441 	if (p != NULL) {
1442 		if (gctx->setswapfs != NULL) {
1443 			kprintf("swapfs %s (ignored) ", p);
1444 		} else 	if (setfs(&nd->swap_saddr,
1445 				  nd->swap_hostnam, p)) {
1446 			gctx->gotswappath = 1;
1447 			gctx->setswapfs = ifctx;
1448 			kprintf("swapfs %s ", p);
1449 
1450 			p = bootpc_tag(&gctx->tag, &ifctx->reply,
1451 				       ifctx->replylen,
1452 				       TAG_SWAPOPTS);
1453 			if (p != NULL) {
1454 				/* swap mount options */
1455 				mountopts(&nd->swap_args, p);
1456 				kprintf("swapopts %s ", p);
1457 			}
1458 
1459 			p = bootpc_tag(&gctx->tag, &ifctx->reply,
1460 				       ifctx->replylen,
1461 				       TAG_SWAPSIZE);
1462 			if (p != NULL) {
1463 				int swaplen;
1464 				if (gctx->tag.taglen != 4)
1465 					panic("bootpc: "
1466 					      "Expected 4 bytes for swaplen, "
1467 					      "not %d bytes",
1468 					      gctx->tag.taglen);
1469 				bcopy(p, &swaplen, 4);
1470 				nd->swap_nblks = ntohl(swaplen);
1471 				kprintf("swapsize %d KB ",
1472 				       nd->swap_nblks);
1473 			}
1474 		} else
1475 			panic("Failed to set swapfs to %s", p);
1476 	}
1477 
1478 	p = bootpc_tag(&gctx->tag, &ifctx->reply, ifctx->replylen,
1479 		       TAG_HOSTNAME);
1480 	if (p != NULL) {
1481 		if (gctx->tag.taglen >= MAXHOSTNAMELEN)
1482 			panic("bootpc: hostname >= %d bytes",
1483 			      MAXHOSTNAMELEN);
1484 		if (gctx->sethostname != NULL) {
1485 			kprintf("hostname %s (ignored) ", p);
1486 		} else {
1487 			strcpy(nd->my_hostnam, p);
1488 			strcpy(hostname, p);
1489 			kprintf("hostname %s ",hostname);
1490 			gctx->sethostname = ifctx;
1491 		}
1492 	}
1493 	p = bootpc_tag(&gctx->tag, &ifctx->reply, ifctx->replylen,
1494 		       TAG_COOKIE);
1495 	if (p != NULL) {	/* store in a sysctl variable */
1496 		int i, l = sizeof(bootp_cookie) - 1;
1497 		for (i = 0; i < l && p[i] != '\0'; i++)
1498 			bootp_cookie[i] = p[i];
1499 		p[i] = '\0';
1500 	}
1501 
1502 	kprintf("\n");
1503 
1504 	if (ifctx->gotnetmask == 0) {
1505 		if (IN_CLASSA(ntohl(ifctx->myaddr.sin_addr.s_addr)))
1506 			ifctx->netmask.sin_addr.s_addr = htonl(IN_CLASSA_NET);
1507 		else if (IN_CLASSB(ntohl(ifctx->myaddr.sin_addr.s_addr)))
1508 			ifctx->netmask.sin_addr.s_addr = htonl(IN_CLASSB_NET);
1509 		else
1510 			ifctx->netmask.sin_addr.s_addr = htonl(IN_CLASSC_NET);
1511 	}
1512 	if (ifctx->gotgw == 0) {
1513 		/* Use proxyarp */
1514 		ifctx->gw.sin_addr.s_addr = ifctx->myaddr.sin_addr.s_addr;
1515 	}
1516 }
1517 
1518 void
1519 bootpc_init(void)
1520 {
1521 	struct bootpc_ifcontext *ifctx, *nctx;	/* Interface BOOTP contexts */
1522 	struct bootpc_globalcontext *gctx; 	/* Global BOOTP context */
1523 	struct ifnet *ifp;
1524 	int error;
1525 	struct nfsv3_diskless *nd;
1526 	struct thread *td;
1527 
1528 	nd = &nfsv3_diskless;
1529 	td = curthread;
1530 
1531 	/*
1532 	 * If already filled in, don't touch it here
1533 	 */
1534 	if (nfs_diskless_valid != 0)
1535 		return;
1536 
1537 	/*
1538 	 * Wait until arp entries can be handled.
1539 	 */
1540 	while (time_second == 0)
1541 		tsleep(&time_second, 0, "arpkludge", 10);
1542 
1543 	gctx = kmalloc(sizeof(*gctx), M_TEMP, M_WAITOK);
1544 	if (gctx == NULL)
1545 		panic("Failed to allocate bootp global context structure");
1546 
1547 	bzero(gctx, sizeof(*gctx));
1548 	gctx->xid = ~0xFFFF;
1549 	gctx->starttime = time_second;
1550 
1551 	ifctx = allocifctx(gctx);
1552 
1553 	/*
1554 	 * Find a network interface.
1555 	 */
1556 #ifdef BOOTP_WIRED_TO
1557 	kprintf("bootpc_init: wired to interface '%s'\n",
1558 	       __XSTRING(BOOTP_WIRED_TO));
1559 #endif
1560 	bzero(&ifctx->ireq, sizeof(ifctx->ireq));
1561 	TAILQ_FOREACH(ifp, &ifnet, if_link) {
1562 		strlcpy(ifctx->ireq.ifr_name, ifp->if_xname,
1563 			 sizeof(ifctx->ireq.ifr_name));
1564 #ifdef BOOTP_WIRED_TO
1565 		if (strcmp(ifctx->ireq.ifr_name,
1566 			   __XSTRING(BOOTP_WIRED_TO)) != 0)
1567 			continue;
1568 #else
1569 		if ((ifp->if_flags &
1570 		     (IFF_LOOPBACK | IFF_POINTOPOINT | IFF_BROADCAST)) !=
1571 		    IFF_BROADCAST)
1572 			continue;
1573 #endif
1574 		if (gctx->interfaces != NULL)
1575 			gctx->lastinterface->next = ifctx;
1576 		else
1577 			gctx->interfaces = ifctx;
1578 		ifctx->ifp = ifp;
1579 		gctx->lastinterface = ifctx;
1580 		ifctx = allocifctx(gctx);
1581 	}
1582 	kfree(ifctx, M_TEMP);
1583 
1584 	if (gctx->interfaces == NULL) {
1585 #ifdef BOOTP_WIRED_TO
1586 		panic("bootpc_init: Could not find interface specified "
1587 		      "by BOOTP_WIRED_TO: "
1588 		      __XSTRING(BOOTP_WIRED_TO));
1589 #else
1590 		panic("bootpc_init: no suitable interface");
1591 #endif
1592 	}
1593 
1594 	gctx->gotrootpath = 0;
1595 	gctx->gotswappath = 0;
1596 	gctx->gotgw = 0;
1597 
1598 	for (ifctx = gctx->interfaces; ifctx != NULL; ifctx = ifctx->next)
1599 		bootpc_fakeup_interface(ifctx, gctx, td);
1600 
1601 	for (ifctx = gctx->interfaces; ifctx != NULL; ifctx = ifctx->next)
1602 		bootpc_compose_query(ifctx, gctx, td);
1603 
1604 	ifctx = gctx->interfaces;
1605 	error = bootpc_call(gctx, td);
1606 
1607 	if (error != 0) {
1608 #ifdef BOOTP_NFSROOT
1609 		panic("BOOTP call failed");
1610 #else
1611 		kprintf("BOOTP call failed\n");
1612 #endif
1613 	}
1614 
1615 	mountopts(&nd->root_args, NULL);
1616 
1617 	mountopts(&nd->swap_args, NULL);
1618 
1619 	for (ifctx = gctx->interfaces; ifctx != NULL; ifctx = ifctx->next)
1620 		if (bootpc_ifctx_isresolved(ifctx) != 0)
1621 			bootpc_decode_reply(nd, ifctx, gctx);
1622 
1623 	if (gctx->gotswappath == 0)
1624 		nd->swap_nblks = 0;
1625 #ifdef BOOTP_NFSROOT
1626 	if (gctx->gotrootpath == 0)
1627 		panic("bootpc: No root path offered");
1628 #endif
1629 
1630 	for (ifctx = gctx->interfaces; ifctx != NULL; ifctx = ifctx->next) {
1631 		bootpc_adjust_interface(ifctx, gctx, td);
1632 
1633 		soclose(ifctx->so, FNONBLOCK);
1634 	}
1635 
1636 	for (ifctx = gctx->interfaces; ifctx != NULL; ifctx = ifctx->next)
1637 		if (ifctx->gotrootpath != 0)
1638 			break;
1639 	if (ifctx == NULL) {
1640 		for (ifctx = gctx->interfaces;
1641 		     ifctx != NULL;
1642 		     ifctx = ifctx->next)
1643 			if (bootpc_ifctx_isresolved(ifctx) != 0)
1644 				break;
1645 	}
1646 	if (ifctx == NULL)
1647 		goto out;
1648 
1649 	if (gctx->gotrootpath != 0) {
1650 
1651 		error = md_mount(&nd->root_saddr, nd->root_hostnam,
1652 				 nd->root_fh, &nd->root_fhsize,
1653 				 &nd->root_args, td);
1654 		if (error != 0)
1655 			panic("nfs_boot: mountd root, error=%d", error);
1656 
1657 		if (gctx->gotswappath != 0) {
1658 
1659 			error = md_mount(&nd->swap_saddr,
1660 					 nd->swap_hostnam,
1661 					 nd->swap_fh, &nd->swap_fhsize,
1662 					 &nd->swap_args, td);
1663 			if (error != 0)
1664 				panic("nfs_boot: mountd swap, error=%d",
1665 				      error);
1666 
1667 			error = md_lookup_swap(&nd->swap_saddr,
1668 					       gctx->lookup_path,
1669 					       nd->swap_fh, &nd->swap_fhsize,
1670 					       &nd->swap_args, td);
1671 			if (error != 0)
1672 				panic("nfs_boot: lookup swap, error=%d",
1673 				      error);
1674 		}
1675 		nfs_diskless_valid = 3;
1676 	}
1677 
1678 	strcpy(nd->myif.ifra_name, ifctx->ireq.ifr_name);
1679 	bcopy(&ifctx->myaddr, &nd->myif.ifra_addr, sizeof(ifctx->myaddr));
1680 	bcopy(&ifctx->myaddr, &nd->myif.ifra_broadaddr, sizeof(ifctx->myaddr));
1681 	((struct sockaddr_in *) &nd->myif.ifra_broadaddr)->sin_addr.s_addr =
1682 		ifctx->myaddr.sin_addr.s_addr |
1683 		~ ifctx->netmask.sin_addr.s_addr;
1684 	bcopy(&ifctx->netmask, &nd->myif.ifra_mask, sizeof(ifctx->netmask));
1685 
1686 out:
1687 	for (ifctx = gctx->interfaces; ifctx != NULL; ifctx = nctx) {
1688 		nctx = ifctx->next;
1689 		kfree(ifctx, M_TEMP);
1690 	}
1691 	kfree(gctx, M_TEMP);
1692 }
1693 
1694