xref: /netbsd-src/sys/nfs/nfs_bootdhcp.c (revision a5a68ff5f29de57339ca14f6c671c0a87714f1f8)
1 /*	$NetBSD: nfs_bootdhcp.c,v 1.2 1997/09/30 20:51:03 drochner Exp $	*/
2 
3 /*-
4  * Copyright (c) 1995, 1997 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Adam Glass and Gordon W. Ross.
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 NetBSD
21  *        Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 /*
40  * Support for NFS diskless booting with BOOTP (RFC951, RFC1048)
41  *
42  * History:
43  *
44  * Tor Egge developed the initial version of this code based on
45  * the Sun RPC/bootparam sources nfs_boot.c and krpc_subr.c and
46  * submitted that work to NetBSD as bugreport "kern/2351" on
47  * 29 Apr 1996.
48  *
49  * Gordon Ross reorganized Tor's version into this form and
50  * integrated it into the NetBSD sources during Aug 1997.
51  */
52 
53 #include <sys/param.h>
54 #include <sys/systm.h>
55 #include <sys/kernel.h>
56 #include <sys/conf.h>
57 #include <sys/device.h>
58 #include <sys/ioctl.h>
59 #include <sys/proc.h>
60 #include <sys/mount.h>
61 #include <sys/mbuf.h>
62 #include <sys/reboot.h>
63 #include <sys/socket.h>
64 #include <sys/socketvar.h>
65 
66 #include <net/if.h>
67 #include <net/if_arp.h> 	/* ARPHRD_ETHER, etc. */
68 #include <net/if_dl.h>
69 #include <net/if_ether.h>
70 #include <net/route.h>
71 
72 #include <netinet/in.h>
73 #include <netinet/if_inarp.h>
74 
75 #include <nfs/nfsproto.h>
76 /* #include <nfs/nfs.h> */
77 #include <nfs/nfsdiskless.h>
78 
79 /*
80  * There are two implementations of NFS diskless boot.
81  * This implementation uses BOOTP (RFC951, RFC1048), and
82  * the other uses Sun RPC/bootparams (nfs_bootparam.c).
83  *
84  * This method gets everything it needs with one BOOTP
85  * request and reply.  Note that this actually uses only
86  * the old BOOTP functionality subset of DHCP.  It is not
87  * clear that DHCP provides any advantage over BOOTP for
88  * diskless boot.  DHCP allows the server to assign an IP
89  * address without any a-priori knowledge of the client,
90  * but we require that the server has a-priori knowledge
91  * of the client so it can export our (unique) NFS root.
92  * Given that the server needs a-priori knowledge about
93  * the client anyway, it might as well assign a fixed IP
94  * address for the client and support BOOTP.
95  *
96  * On the other hand, disk-FULL clients may use DHCP, but
97  * in that case the DHCP client should be user-mode code,
98  * and has no bearing on the code below. -gwr
99  */
100 
101 /* Begin stuff from bootp.h */
102 /* Definitions from RFC951 */
103 #define BP_CHADDR_LEN	 16
104 #define BP_SNAME_LEN	 64
105 #define BP_FILE_LEN	128
106 #define BP_VEND_LEN	 64
107 struct bootp {
108 	u_int8_t	bp_op;		/* packet opcode type */
109 	u_int8_t	bp_htype;	/* hardware addr type */
110 	u_int8_t	bp_hlen;	/* hardware addr length */
111 	u_int8_t	bp_hops;	/* gateway hops */
112 	u_int32_t	bp_xid;		/* transaction ID */
113 	u_int16_t	bp_secs;	/* seconds since boot began */
114 	u_int16_t	bp_flags;	/* RFC1532 broadcast, etc. */
115 	struct in_addr	bp_ciaddr;	/* client IP address */
116 	struct in_addr	bp_yiaddr;	/* 'your' IP address */
117 	struct in_addr	bp_siaddr;	/* server IP address */
118 	struct in_addr	bp_giaddr;	/* gateway IP address */
119 	u_int8_t bp_chaddr[BP_CHADDR_LEN]; /* client hardware address */
120 	char	bp_sname[BP_SNAME_LEN]; /* server host name */
121 	char	bp_file[BP_FILE_LEN];	/* boot file name */
122 	u_int8_t bp_vend[BP_VEND_LEN];	/* RFC1048 options */
123 	/*
124 	 * Note that BOOTP packets are allowed to be longer
125 	 * (see RFC 1532 sect. 2.1) and common practice is to
126 	 * allow the option data in bp_vend to extend into the
127 	 * additional space provided in longer packets.
128 	 */
129 };
130 
131 #define IPPORT_BOOTPS 67
132 #define IPPORT_BOOTPC 68
133 
134 #define BOOTREQUEST		1
135 #define BOOTREPLY		2
136 
137 /*
138  * Is this available from the sockaddr_dl somehow?
139  * Perhaps (struct arphdr)->ar_hrd = ARPHRD_ETHER?
140  * The interface has ->if_type but not the ARP fmt.
141  */
142 #define HTYPE_ETHERNET		  1
143 
144 /*
145  * Vendor magic cookie (v_magic) for RFC1048
146  */
147 static const u_int8_t vm_rfc1048[4] = { 99, 130, 83, 99 };
148 
149 /*
150  * Tag values used to specify what information is being supplied in
151  * the vendor (options) data area of the packet.
152  */
153 /* RFC 1048 */
154 #define TAG_END			((unsigned char) 255)
155 #define TAG_PAD			((unsigned char)   0)
156 #define TAG_SUBNET_MASK		((unsigned char)   1)
157 #define TAG_TIME_OFFSET		((unsigned char)   2)
158 #define TAG_GATEWAY		((unsigned char)   3)
159 #define TAG_TIME_SERVER		((unsigned char)   4)
160 #define TAG_NAME_SERVER		((unsigned char)   5)
161 #define TAG_DOMAIN_SERVER	((unsigned char)   6)
162 #define TAG_LOG_SERVER		((unsigned char)   7)
163 #define TAG_COOKIE_SERVER	((unsigned char)   8)
164 #define TAG_LPR_SERVER		((unsigned char)   9)
165 #define TAG_IMPRESS_SERVER	((unsigned char)  10)
166 #define TAG_RLP_SERVER		((unsigned char)  11)
167 #define TAG_HOST_NAME		((unsigned char)  12)
168 #define TAG_BOOT_SIZE		((unsigned char)  13)
169 /* RFC 1395 */
170 #define TAG_DUMP_FILE		((unsigned char)  14)
171 #define TAG_DOMAIN_NAME		((unsigned char)  15)
172 #define TAG_SWAP_SERVER		((unsigned char)  16)
173 #define TAG_ROOT_PATH		((unsigned char)  17)
174 /* End of stuff from bootp.h */
175 
176 #ifdef NFS_BOOT_DHCP
177 #define TAG_REQ_ADDR		((unsigned char)  50)
178 #define TAG_LEASETIME		((unsigned char)  51)
179 #define TAG_OVERLOAD		((unsigned char)  52)
180 #define TAG_DHCP_MSGTYPE	((unsigned char)  53)
181 #define TAG_SERVERID		((unsigned char)  54)
182 #define TAG_PARAM_REQ		((unsigned char)  55)
183 #define TAG_MSG			((unsigned char)  56)
184 #define TAG_MAXSIZE		((unsigned char)  57)
185 #define TAG_T1			((unsigned char)  58)
186 #define TAG_T2			((unsigned char)  59)
187 #define TAG_CLASSID		((unsigned char)  60)
188 #define TAG_CLIENTID		((unsigned char)  61)
189 #endif
190 
191 #ifdef NFS_BOOT_DHCP
192 #define DHCPDISCOVER 1
193 #define DHCPOFFER 2
194 #define DHCPREQUEST 3
195 #define DHCPDECLINE 4
196 #define DHCPACK 5
197 #define DHCPNAK 6
198 #define DHCPRELEASE 7
199 #endif
200 
201 #ifdef NFS_BOOT_DHCP
202 #define BOOTP_SIZE_MAX	(sizeof(struct bootp)+312-64)
203 #else
204 /*
205  * The "extended" size is somewhat arbitrary, but is
206  * constrained by the maximum message size specified
207  * by RFC1533 (567 total).  This value increases the
208  * space for options from 64 bytes to 256 bytes.
209  */
210 #define BOOTP_SIZE_MAX	(sizeof(struct bootp)+256-64)
211 #endif
212 #define BOOTP_SIZE_MIN	(sizeof(struct bootp))
213 
214 /* Convenience macro */
215 #define INTOHL(ina) ((u_int32_t)ntohl((ina).s_addr))
216 
217 static int bootpc_call __P((struct socket *, struct ifnet *,
218 			struct nfs_diskless *, struct proc *));
219 static void bootp_extract __P((struct bootp *, int, struct nfs_diskless *));
220 
221 /* #define DEBUG	XXX */
222 
223 #ifdef	DEBUG
224 #define DPRINT(s) printf("nfs_boot: %s\n", s)
225 #else
226 #define DPRINT(s) (void)0
227 #endif
228 
229 
230 /*
231  * Get our boot parameters using BOOTP.
232  */
233 int
234 nfs_bootdhcp(ifp, nd, procp)
235 	struct ifnet *ifp;
236 	struct nfs_diskless *nd;
237 	struct proc *procp;
238 {
239 	struct ifaliasreq iareq;
240 	struct socket *so;
241 	struct sockaddr_in *sin;
242 	int error;
243 
244 	/*
245 	 * Get a socket to use for various things in here.
246 	 * After this, use "goto out" to cleanup and return.
247 	 */
248 	error = socreate(AF_INET, &so, SOCK_DGRAM, 0);
249 	if (error) {
250 		printf("nfs_boot: socreate, error=%d\n", error);
251 		return (error);
252 	}
253 
254 	/*
255 	 * Do enough of ifconfig(8) so that the chosen interface
256 	 * can talk to the servers.  Use address zero for now.
257 	 */
258 	bzero(&iareq, sizeof(iareq));
259 	bcopy(ifp->if_xname, iareq.ifra_name, IFNAMSIZ);
260 	/* Set the I/F address */
261 	sin = (struct sockaddr_in *)&iareq.ifra_addr;
262 	sin->sin_len = sizeof(*sin);
263 	sin->sin_family = AF_INET;
264 	sin->sin_addr.s_addr = INADDR_ANY;
265 	/* Leave subnetmask unspecified (len=0) */
266 	/* Set the broadcast addr. */
267 	sin = (struct sockaddr_in *)&iareq.ifra_broadaddr;
268 	sin->sin_len = sizeof(*sin);
269 	sin->sin_family = AF_INET;
270 	sin->sin_addr.s_addr = INADDR_BROADCAST;
271 	error = ifioctl(so, SIOCAIFADDR, (caddr_t)&iareq, procp);
272 	if (error) {
273 		printf("nfs_boot: set ifaddr zero, error=%d\n", error);
274 		goto out;
275 	}
276 
277 	/* This function call does the real send/recv work. */
278 	error = bootpc_call(so, ifp, nd, procp);
279 	/* Get rid of the temporary (zero) IP address. */
280 	/*
281 	 * XXX SIOCDIFADDR takes a "struct ifreq", which is
282 	 * an exact subset of "struct ifaliasreq".
283 	 */
284 	(void) ifioctl(so, SIOCDIFADDR, (caddr_t)&iareq, procp);
285 	/* NOW we can test the error from bootpc_call. */
286 	if (error)
287 		goto out;
288 
289 	/*
290 	 * Do ifconfig with our real IP address and mask.
291 	 */
292 	/* I/F address */
293 	sin = (struct sockaddr_in *)&iareq.ifra_addr;
294 	sin->sin_addr = nd->nd_myip;
295 	/* subnetmask */
296 	if (nd->nd_mask.s_addr) {
297 		sin = (struct sockaddr_in *)&iareq.ifra_mask;
298 		sin->sin_len = sizeof(*sin);
299 		sin->sin_family = AF_INET;
300 		sin->sin_addr = nd->nd_mask;
301 	}
302 	/* Let ifioctl() default the broadcast address. */
303 	sin = (struct sockaddr_in *)&iareq.ifra_broadaddr;
304 	sin->sin_len = 0;
305 	sin->sin_family = 0;
306 	sin->sin_addr.s_addr = 0;
307 	error = ifioctl(so, SIOCAIFADDR, (caddr_t)&iareq, procp);
308 	if (error) {
309 		printf("nfs_boot: set ifaddr real, error=%d\n", error);
310 		goto out;
311 	}
312 
313 out:
314 	soclose(so);
315 	return (error);
316 }
317 
318 struct bootpcontext {
319 	int xid;
320 	u_char *haddr;
321 	u_char halen;
322 	struct bootp *replybuf;
323 	int replylen;
324 #ifdef NFS_BOOT_DHCP
325 	char expected_dhcpmsgtype, dhcp_ok;
326 	struct in_addr dhcp_serverip;
327 #endif
328 };
329 
330 static int bootpset __P((struct mbuf*, void*, int));
331 static int bootpcheck __P((struct mbuf*, void*));
332 
333 static int bootpset(m, context, waited)
334 struct mbuf *m;
335 void *context;
336 int waited;
337 {
338 	struct bootp *bootp;
339 
340 	/* we know it's contigous (in 1 mbuf cluster) */
341 	bootp = mtod(m, struct bootp*);
342 
343 	bootp->bp_secs = htons(waited);
344 
345 	return(0);
346 }
347 
348 static int bootpcheck(m, context)
349 struct mbuf *m;
350 void *context;
351 {
352 	struct bootp *bootp;
353 	struct bootpcontext *bpc = context;
354 	u_int tag, len;
355 	u_char *p, *limit;
356 
357 	/*
358 	 * Is this a valid reply?
359 	 */
360 	if (m->m_pkthdr.len < BOOTP_SIZE_MIN) {
361 		DPRINT("short packet");
362 		return(-1);
363 	}
364 	if (m->m_pkthdr.len > BOOTP_SIZE_MAX) {
365 		DPRINT("long packet");
366 		return(-1);
367 	}
368 
369 	/*
370 	 * don't make first checks more expensive than necessary
371 	 */
372 #define ofs(what, elem) ((int)&(((what *)0)->elem))
373 	if (m->m_len < ofs(struct bootp, bp_secs)) {
374 		m = m_pullup(m, ofs(struct bootp, bp_secs));
375 		if (m == NULL)
376 			return(-1);
377 	}
378 #undef ofs
379 	bootp = mtod(m, struct bootp*);
380 
381 	if (bootp->bp_op != BOOTREPLY) {
382 		DPRINT("not reply");
383 		return(-1);
384 	}
385 	if (bootp->bp_hlen != bpc->halen) {
386 		DPRINT("bad hwa_len");
387 		return(-1);
388 	}
389 	if (bcmp(bootp->bp_chaddr, bpc->haddr, bpc->halen)) {
390 		DPRINT("wrong hwaddr");
391 		return(-1);
392 	}
393 	if (bootp->bp_xid != bpc->xid) {
394 		DPRINT("wrong xid");
395 		return(-1);
396 	}
397 
398 	/*
399 	 * OK, it's worth to look deeper.
400 	 * We copy the mbuf into a flat buffer here because
401 	 * m_pullup() is a bit limited for this purpose
402 	 * (doesn't allocate a cluster if necessary).
403 	 */
404 	bpc->replylen = m->m_pkthdr.len;
405 	m_copydata(m, 0, bpc->replylen, (caddr_t)bpc->replybuf);
406 	bootp = bpc->replybuf;
407 
408 	/*
409 	 * Check the vendor data.
410 	 */
411 	if (bcmp(bootp->bp_vend, vm_rfc1048, 4)) {
412 		printf("nfs_boot: reply missing options\n");
413 		return(-1);
414 	}
415 	p = &bootp->bp_vend[4];
416 	limit = ((char*)bootp) + bpc->replylen;
417 	while (p < limit) {
418 		tag = *p++;
419 		if (tag == TAG_END)
420 			break;
421 		if (tag == TAG_PAD)
422 			continue;
423 		len = *p++;
424 		if ((p + len) > limit) {
425 			printf("nfs_boot: option %d too long\n", tag);
426 			return(-1);
427 		}
428 		switch (tag) {
429 #ifdef NFS_BOOT_DHCP
430 		    case TAG_DHCP_MSGTYPE:
431 			if (*p != bpc->expected_dhcpmsgtype)
432 				return(-1);
433 			bpc->dhcp_ok = 1;
434 			break;
435 		    case TAG_SERVERID:
436 			bcopy(p, &bpc->dhcp_serverip.s_addr,
437 			      sizeof(bpc->dhcp_serverip.s_addr));
438 			break;
439 #endif
440 		    default:
441 			break;
442 		}
443 		p += len;
444 	}
445 	return(0);
446 }
447 
448 static int
449 bootpc_call(so, ifp, nd, procp)
450 	struct socket *so;
451 	struct ifnet *ifp;
452 	struct nfs_diskless *nd;
453 	struct proc *procp;
454 {
455 	static u_int32_t xid = ~0xFF;
456 	struct bootp *bootp;	/* request */
457 	struct mbuf *m, *nam;
458 	struct sockaddr_in *sin;
459 	int error;
460 	u_char *haddr;
461 	u_char hafmt, halen;
462 	struct bootpcontext bpc;
463 
464 	/*
465 	 * Initialize to NULL anything that will hold an allocation,
466 	 * and free each at the end if not null.
467 	 */
468 	bpc.replybuf = NULL;
469 	m = nam = NULL;
470 
471 	/* Record our H/W (Ethernet) address. */
472 	{	struct sockaddr_dl *sdl = ifp->if_sadl;
473 		hafmt = HTYPE_ETHERNET; /* XXX: sdl->sdl_type? */
474 		halen = sdl->sdl_alen;
475 		haddr = (unsigned char *)LLADDR(sdl);
476 	}
477 
478 	/*
479 	 * Skip the route table when sending on this socket.
480 	 * If this is not done, ip_output finds the loopback
481 	 * interface (why?) and then fails because broadcast
482 	 * is not supported on that interface...
483 	 */
484 	{	int32_t *opt;
485 		m = m_get(M_WAIT, MT_SOOPTS);
486 		opt = mtod(m, int32_t *);
487 		m->m_len = sizeof(*opt);
488 		*opt = 1;
489 		error = sosetopt(so, SOL_SOCKET, SO_DONTROUTE, m);
490 		m = NULL;	/* was consumed */
491 	}
492 	if (error) {
493 		DPRINT("SO_DONTROUTE");
494 		goto out;
495 	}
496 
497 	/* Enable broadcast. */
498 	if ((error = nfs_boot_enbroadcast(so))) {
499 		DPRINT("SO_BROADCAST");
500 		goto out;
501 	}
502 
503 	/* Set the receive timeout for the socket. */
504 	if ((error = nfs_boot_setrecvtimo(so))) {
505 		DPRINT("SO_RCVTIMEO");
506 		goto out;
507 	}
508 
509 	/*
510 	 * Bind the local endpoint to a bootp client port.
511 	 */
512 	if ((error = nfs_boot_sobind_ipport(so, IPPORT_BOOTPC))) {
513 		DPRINT("bind failed\n");
514 		goto out;
515 	}
516 
517 	/*
518 	 * Setup socket address for the server.
519 	 */
520 	nam = m_get(M_WAIT, MT_SONAME);
521 	sin = mtod(nam, struct sockaddr_in *);
522 	sin->sin_len = nam->m_len = sizeof(*sin);
523 	sin->sin_family = AF_INET;
524 	sin->sin_addr.s_addr = INADDR_BROADCAST;
525 	sin->sin_port = htons(IPPORT_BOOTPS);
526 
527 	/*
528 	 * Allocate buffer used for request
529 	 */
530 	m = m_gethdr(M_WAIT, MT_DATA);
531 	MCLGET(m, M_WAIT);
532 	bootp = mtod(m, struct bootp*);
533 	m->m_pkthdr.len = m->m_len = BOOTP_SIZE_MAX;
534 	m->m_pkthdr.rcvif = NULL;
535 
536 	/*
537 	 * Build the BOOTP reqest message.
538 	 * Note: xid is host order! (opaque to server)
539 	 */
540 	bzero((caddr_t)bootp, BOOTP_SIZE_MAX);
541 	bootp->bp_op    = BOOTREQUEST;
542 	bootp->bp_htype = hafmt;
543 	bootp->bp_hlen  = halen;	/* Hardware address length */
544 	bootp->bp_xid = ++xid;
545 	bcopy(haddr, bootp->bp_chaddr, halen);
546 	/* Fill-in the vendor data. */
547 	bcopy(vm_rfc1048, bootp->bp_vend, 4);
548 #ifdef NFS_BOOT_DHCP
549 	bootp->bp_vend[4] = TAG_DHCP_MSGTYPE;
550 	bootp->bp_vend[5] = 1;
551 	bootp->bp_vend[6] = DHCPDISCOVER;
552 	bootp->bp_vend[7] = TAG_END;
553 #else
554 	bootp->bp_vend[4] = TAG_END;
555 #endif
556 
557 	bpc.xid = xid;
558 	bpc.haddr = haddr;
559 	bpc.halen = halen;
560 	bpc.replybuf = malloc(BOOTP_SIZE_MAX, M_DEVBUF, M_WAITOK);
561 	if (bpc.replybuf == NULL)
562 		panic("nfs_boot: malloc reply buf");
563 #ifdef NFS_BOOT_DHCP
564 	bpc.expected_dhcpmsgtype = DHCPOFFER;
565 	bpc.dhcp_ok = 0;
566 #endif
567 
568 	error = nfs_boot_sendrecv(so, nam, bootpset, m,
569 				  bootpcheck, 0, 0, &bpc);
570 	if (error)
571 		goto out;
572 
573 #ifdef NFS_BOOT_DHCP
574 	if (bpc.dhcp_ok) {
575 		u_int32_t leasetime;
576 		bootp->bp_vend[6] = DHCPREQUEST;
577 		bootp->bp_vend[7] = TAG_REQ_ADDR;
578 		bootp->bp_vend[8] = 4;
579 		bcopy(&bpc.replybuf->bp_yiaddr, &bootp->bp_vend[9], 4);
580 		bootp->bp_vend[13] = TAG_SERVERID;
581 		bootp->bp_vend[14] = 4;
582 		bcopy(&bpc.dhcp_serverip.s_addr, &bootp->bp_vend[15], 4);
583 		bootp->bp_vend[19] = TAG_LEASETIME;
584 		bootp->bp_vend[20] = 4;
585 		leasetime = htonl(300);
586 		bcopy(&leasetime, &bootp->bp_vend[21], 4);
587 		bootp->bp_vend[25] = TAG_END;
588 
589 		bpc.expected_dhcpmsgtype = DHCPACK;
590 
591 		error = nfs_boot_sendrecv(so, nam, bootpset, m,
592 					  bootpcheck, 0, 0, &bpc);
593 		if (error)
594 			goto out;
595 	}
596 #endif
597 
598 	/*
599 	 * bootpcheck() has copied the receive mbuf into
600 	 * the buffer at bpc.replybuf.
601 	 */
602 	bootp_extract(bpc.replybuf, bpc.replylen, nd);
603 
604 out:
605 	if (bpc.replybuf)
606 		free(bpc.replybuf, M_DEVBUF);
607 	if (m)
608 		m_freem(m);
609 	if (nam)
610 		m_freem(nam);
611 	return (error);
612 }
613 
614 static void bootp_extract(bootp, replylen, nd)
615 	struct bootp *bootp;
616 	int replylen;
617 	struct nfs_diskless *nd;
618 {
619 	struct sockaddr_in *sin;
620 	struct in_addr netmask;
621 	struct in_addr gateway;
622 	struct in_addr rootserver;
623 	char *myname;	/* my hostname */
624 	char *mydomain;	/* my domainname */
625 	char *rootpath;
626 	int mynamelen;
627 	int mydomainlen;
628 	int rootpathlen;
629 	u_int tag, len;
630 	u_char *p, *limit;
631 
632 	/* Default these to "unspecified". */
633 	netmask.s_addr = 0;
634 	gateway.s_addr = 0;
635 	mydomain    = myname    = rootpath = NULL;
636 	mydomainlen = mynamelen = rootpathlen = 0;
637 	/* default root server to bootp next-server */
638 	rootserver = bootp->bp_siaddr;
639 
640 	p = &bootp->bp_vend[4];
641 	limit = ((char*)bootp) + replylen;
642 	while (p < limit) {
643 		tag = *p++;
644 		if (tag == TAG_END)
645 			break;
646 		if (tag == TAG_PAD)
647 			continue;
648 		len = *p++;
649 		if ((p + len) > limit) {
650 			printf("nfs_boot: option %d too long\n", tag);
651 			break;
652 		}
653 		switch (tag) {
654 		    case TAG_SUBNET_MASK:
655 			bcopy(p, &netmask, 4);
656 			break;
657 		    case TAG_GATEWAY:
658 			/* Routers */
659 			bcopy(p, &gateway, 4);
660 			break;
661 		    case TAG_HOST_NAME:
662 			if (len >= sizeof(hostname)) {
663 				printf("nfs_boot: host name >=%d bytes",
664 				       sizeof(hostname));
665 				break;
666 			}
667 			myname = p;
668 			mynamelen = len;
669 			break;
670 		    case TAG_DOMAIN_NAME:
671 			if (len >= sizeof(domainname)) {
672 				printf("nfs_boot: domain name >=%d bytes",
673 				       sizeof(domainname));
674 				break;
675 			}
676 			mydomain = p;
677 			mydomainlen = len;
678 			break;
679 		    case TAG_ROOT_PATH:
680 			/* Leave some room for the server name. */
681 			if (len >= (MNAMELEN-10)) {
682 				printf("nfs_boot: rootpath >=%d bytes",
683 				       (MNAMELEN-10));
684 				break;
685 			}
686 			rootpath = p;
687 			rootpathlen = len;
688 			break;
689 		    case TAG_SWAP_SERVER:
690 			/* override NFS server address */
691 			bcopy(p, &rootserver, 4);
692 			break;
693 		    default:
694 			break;
695 		}
696 		p += len;
697 	}
698 
699 	/*
700 	 * Store and print network config info.
701 	 */
702 	if (myname) {
703 		myname[mynamelen] = '\0';
704 		strncpy(hostname, myname, sizeof(hostname));
705 		hostnamelen = mynamelen;
706 		printf("nfs_boot: my_name=%s\n", hostname);
707 	}
708 	if (mydomain) {
709 		mydomain[mydomainlen] = '\0';
710 		strncpy(domainname, mydomain, sizeof(domainname));
711 		domainnamelen = mydomainlen;
712 		printf("nfs_boot: my_domain=%s\n", domainname);
713 	}
714 	nd->nd_myip = bootp->bp_yiaddr;
715 	if (nd->nd_myip.s_addr)
716 		printf("nfs_boot: my_addr=0x%x\n", INTOHL(nd->nd_myip));
717 	nd->nd_mask = netmask;
718 	if (nd->nd_mask.s_addr)
719 		printf("nfs_boot: my_mask=0x%x\n", INTOHL(nd->nd_mask));
720 	nd->nd_gwip = gateway;
721 	if (nd->nd_gwip.s_addr)
722 		printf("nfs_boot: gateway=0x%x\n", INTOHL(nd->nd_gwip));
723 
724 	/*
725 	 * Store the information about our NFS root mount.
726 	 * The caller will print it, so be silent here.
727 	 */
728 	{
729 		struct nfs_dlmount *ndm = &nd->nd_root;
730 
731 		/* Server IP address. */
732 		sin = (struct sockaddr_in *) &ndm->ndm_saddr;
733 		bzero((caddr_t)sin, sizeof(*sin));
734 		sin->sin_len = sizeof(*sin);
735 		sin->sin_family = AF_INET;
736 		sin->sin_addr = rootserver;
737 		/* Server name. */
738 		if (!bcmp(&rootserver, &bootp->bp_siaddr,
739 			  sizeof(struct in_addr))) {
740 			/* standard root server, we have the name */
741 			strncpy(ndm->ndm_host, bootp->bp_sname, BP_SNAME_LEN-1);
742 		} else {
743 			/* Show the server IP address numerically. */
744 			sprintf(ndm->ndm_host, "0x%8x",
745 				INTOHL(rootserver));
746 		}
747 		len = strlen(ndm->ndm_host);
748 		if (rootpath &&
749 		    len + 1 + rootpathlen + 1 <= sizeof(ndm->ndm_host)) {
750 			ndm->ndm_host[len++] = ':';
751 			strncpy(ndm->ndm_host + len,
752 				rootpath, rootpathlen);
753 			ndm->ndm_host[len + rootpathlen] = '\0';
754 		} /* else: upper layer will handle error */
755 	}
756 }
757