xref: /openbsd/sys/nfs/nfs_boot.c (revision 73471bf0)
1 /*	$OpenBSD: nfs_boot.c,v 1.47 2021/01/19 19:35:59 mvs Exp $ */
2 /*	$NetBSD: nfs_boot.c,v 1.26 1996/05/07 02:51:25 thorpej Exp $	*/
3 
4 /*
5  * Copyright (c) 1995 Adam Glass, Gordon Ross
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. The name of the authors may not be used to endorse or promote products
17  *    derived from this software without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22  * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 #include <sys/param.h>
32 #include <sys/systm.h>
33 #include <sys/kernel.h>
34 #include <sys/conf.h>
35 #include <sys/ioctl.h>
36 #include <sys/mount.h>
37 #include <sys/mbuf.h>
38 #include <sys/reboot.h>
39 #include <sys/socket.h>
40 #include <sys/socketvar.h>
41 #include <sys/queue.h>
42 
43 #include <net/if.h>
44 #include <net/if_var.h>
45 
46 #include <netinet/in.h>
47 #include <netinet/in_var.h>
48 #include <netinet/if_ether.h>
49 
50 #include <nfs/rpcv2.h>
51 #include <nfs/nfsproto.h>
52 #include <nfs/nfs.h>
53 #include <nfs/nfsdiskless.h>
54 #include <nfs/krpc.h>
55 #include <nfs/xdr_subs.h>
56 #include <nfs/nfs_var.h>
57 
58 #include "ether.h"
59 
60 #if !defined(NFSCLIENT) || (NETHER == 0 && NFDDI == 0)
61 
62 int
63 nfs_boot_init(struct nfs_diskless *nd, struct proc *procp)
64 {
65 	panic("nfs_boot_init: NFSCLIENT not enabled in kernel");
66 }
67 
68 int
69 nfs_boot_getfh(struct sockaddr_in *bpsin, char *key,
70     struct nfs_dlmount *ndmntp, int retries)
71 {
72 	/* can not get here */
73 	return (EOPNOTSUPP);
74 }
75 
76 #else
77 
78 /*
79  * Support for NFS diskless booting, specifically getting information
80  * about where to boot from, what pathnames, etc.
81  *
82  * This implementation uses RARP and the bootparam RPC.
83  * We are forced to implement RPC anyway (to get file handles)
84  * so we might as well take advantage of it for bootparam too.
85  *
86  * The diskless boot sequence goes as follows:
87  * (1) Use RARP to get our interface address
88  * (2) Use RPC/bootparam/whoami to get our hostname,
89  *     our IP address, and the server's IP address.
90  * (3) Use RPC/bootparam/getfile to get the root path
91  * (4) Use RPC/mountd to get the root file handle
92  * (5) Use RPC/bootparam/getfile to get the swap path
93  * (6) Use RPC/mountd to get the swap file handle
94  *
95  * (This happens to be the way Sun does it too.)
96  */
97 
98 /* bootparam RPC */
99 static int bp_whoami(struct sockaddr_in *bpsin,
100 	struct in_addr *my_ip, struct in_addr *gw_ip);
101 static int bp_getfile(struct sockaddr_in *bpsin, char *key,
102 	struct sockaddr_in *mdsin, char *servname, char *path, int retries);
103 
104 /* mountd RPC */
105 static int md_mount(struct sockaddr_in *mdsin, char *path,
106 	struct nfs_args *argp);
107 
108 char	*nfsbootdevname;
109 
110 /*
111  * Called with an empty nfs_diskless struct to be filled in.
112  */
113 int
114 nfs_boot_init(struct nfs_diskless *nd, struct proc *procp)
115 {
116 	struct ifreq ireq;
117 	struct in_aliasreq ifra;
118 	struct in_addr my_ip, gw_ip;
119 	struct sockaddr_in bp_sin;
120 	struct sockaddr_in *sin;
121 	struct ifnet *ifp;
122 	struct socket *so;
123 	struct ifaddr *ifa;
124 	char addr[INET_ADDRSTRLEN];
125 	int error;
126 
127 	/*
128 	 * Find an interface, rarp for its ip address, stuff it, the
129 	 * implied broadcast addr, and netmask into a nfs_diskless struct.
130 	 *
131 	 * This was moved here from nfs_vfsops.c because this procedure
132 	 * would be quite different if someone decides to write (i.e.) a
133 	 * BOOTP version of this file (might not use RARP, etc.)
134 	 */
135 
136 	/*
137 	 * Find a network interface.
138 	 */
139 	if (nfsbootdevname == NULL || (ifp = if_unit(nfsbootdevname)) == NULL)
140 		panic("nfs_boot: no suitable interface");
141 
142 	bcopy(ifp->if_xname, ireq.ifr_name, IFNAMSIZ);
143 	printf("nfs_boot: using interface %s, with revarp & bootparams\n",
144 	    ireq.ifr_name);
145 
146 	/*
147 	 * Bring up the interface.
148 	 *
149 	 * Get the old interface flags and or IFF_UP into them; if
150 	 * IFF_UP set blindly, interface selection can be clobbered.
151 	 */
152 	if ((error = socreate(AF_INET, &so, SOCK_DGRAM, 0)) != 0)
153 		panic("nfs_boot: socreate, error=%d", error);
154 	error = ifioctl(so, SIOCGIFFLAGS, (caddr_t)&ireq, procp);
155 	if (error)
156 		panic("nfs_boot: GIFFLAGS, error=%d", error);
157 	ireq.ifr_flags |= IFF_UP;
158 	error = ifioctl(so, SIOCSIFFLAGS, (caddr_t)&ireq, procp);
159 	if (error)
160 		panic("nfs_boot: SIFFLAGS, error=%d", error);
161 
162 	/*
163 	 * Do RARP for the interface address.
164 	 */
165 	if ((error = revarpwhoami(&my_ip, ifp)) != 0)
166 		panic("reverse arp not answered by rarpd(8) or dhcpd(8)");
167 	inet_ntop(AF_INET, &my_ip, addr, sizeof(addr));
168 	printf("nfs_boot: client_addr=%s\n", addr);
169 
170 	/*
171 	 * Do enough of ifconfig(8) so that the chosen interface
172 	 * can talk to the servers.  (just set the address)
173 	 */
174 	memset(&ifra, 0, sizeof(ifra));
175 	bcopy(ifp->if_xname, ifra.ifra_name, sizeof(ifra.ifra_name));
176 
177 	sin = &ifra.ifra_addr;
178 	sin->sin_len = sizeof(*sin);
179 	sin->sin_family = AF_INET;
180 	sin->sin_addr.s_addr = my_ip.s_addr;
181 	error = ifioctl(so, SIOCAIFADDR, (caddr_t)&ifra, procp);
182 	if (error)
183 		panic("nfs_boot: set if addr, error=%d", error);
184 
185 	soclose(so, 0);
186 
187 	TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) {
188 		if (ifa->ifa_addr->sa_family == AF_INET)
189 			break;
190 	}
191 	if (ifa == NULL)
192 		panic("nfs_boot: address not configured on %s", ifp->if_xname);
193 	if_put(ifp);
194 
195 	/*
196 	 * Get client name and gateway address.
197 	 * RPC: bootparam/whoami
198 	 * The server address returned by the WHOAMI call
199 	 * is used for all subsequent bootparam RPCs.
200 	 */
201 	memset(&bp_sin, 0, sizeof(bp_sin));
202 	bp_sin.sin_len = sizeof(bp_sin);
203 	bp_sin.sin_family = AF_INET;
204 	bp_sin.sin_addr.s_addr = ifatoia(ifa)->ia_broadaddr.sin_addr.s_addr;
205 	hostnamelen = MAXHOSTNAMELEN;
206 
207 	/* this returns gateway IP address */
208 	error = bp_whoami(&bp_sin, &my_ip, &gw_ip);
209 	if (error)
210 		panic("nfs_boot: bootparam whoami, error=%d", error);
211 	inet_ntop(AF_INET, &bp_sin.sin_addr, addr, sizeof(addr));
212 	printf("nfs_boot: server_addr=%s hostname=%s\n", addr, hostname);
213 
214 	bcopy(&bp_sin, &nd->nd_boot, sizeof(bp_sin));
215 
216 	return (0);
217 }
218 
219 /*
220  * bpsin:	bootparam server
221  * key:		root or swap
222  * ndmntp:	output
223  */
224 int
225 nfs_boot_getfh(struct sockaddr_in *bpsin, char *key,
226     struct nfs_dlmount *ndmntp, int retries)
227 {
228 	struct nfs_args *args;
229 	char pathname[MAXPATHLEN];
230 	char *sp, *dp, *endp;
231 	struct sockaddr_in *sin;
232 	int error;
233 
234 	args = &ndmntp->ndm_args;
235 
236 	/* Initialize mount args. */
237 	memset(args, 0, sizeof(*args));
238 	args->addr     = sintosa(&ndmntp->ndm_saddr);
239 	args->addrlen  = args->addr->sa_len;
240 	args->sotype   = SOCK_DGRAM;
241 	args->fh       = ndmntp->ndm_fh;
242 	args->hostname = ndmntp->ndm_host;
243 	args->flags    = NFSMNT_NFSV3;
244 #ifdef	NFS_BOOT_OPTIONS
245 	args->flags    |= NFS_BOOT_OPTIONS;
246 #endif
247 #ifdef	NFS_BOOT_RWSIZE
248 	/*
249 	 * Reduce rsize,wsize for interfaces that consistently
250 	 * drop fragments of long UDP messages.	 (i.e. wd8003).
251 	 * You can always change these later via remount.
252 	 */
253 	args->flags   |= NFSMNT_WSIZE | NFSMNT_RSIZE;
254 	args->wsize    = NFS_BOOT_RWSIZE;
255 	args->rsize    = NFS_BOOT_RWSIZE;
256 #endif
257 
258 	sin = &ndmntp->ndm_saddr;
259 
260 	/*
261 	 * Get server:pathname for "key" (root or swap)
262 	 * using RPC to bootparam/getfile
263 	 */
264 	error = bp_getfile(bpsin, key, sin, ndmntp->ndm_host, pathname,
265 	    retries);
266 	if (error) {
267 		printf("nfs_boot: bootparam get %s: %d\n", key, error);
268 		return (error);
269 	}
270 
271 	/*
272 	 * Get file handle for "key" (root or swap)
273 	 * using RPC to mountd/mount
274 	 */
275 	error = md_mount(sin, pathname, args);
276 	if (error) {
277 		printf("nfs_boot: mountd %s, error=%d\n", key, error);
278 		return (error);
279 	}
280 
281 	/* Set port number for NFS use. */
282 	/* XXX: NFS port is always 2049, right? */
283 	error = krpc_portmap(sin, NFS_PROG,
284 	    (args->flags & NFSMNT_NFSV3) ? NFS_VER3 : NFS_VER2,
285 	    &sin->sin_port);
286 	if (error) {
287 		printf("nfs_boot: portmap NFS, error=%d\n", error);
288 		return (error);
289 	}
290 
291 	/* Construct remote path (for getmntinfo(3)) */
292 	dp = ndmntp->ndm_host;
293 	endp = dp + MNAMELEN - 1;
294 	dp += strlen(dp);
295 	*dp++ = ':';
296 	for (sp = pathname; *sp && dp < endp;)
297 		*dp++ = *sp++;
298 	*dp = '\0';
299 
300 	return (0);
301 }
302 
303 
304 /*
305  * RPC: bootparam/whoami
306  * Given client IP address, get:
307  *	client name	(hostname)
308  *	domain name (domainname)
309  *	gateway address
310  *
311  * The hostname and domainname are set here for convenience.
312  *
313  * Note - bpsin is initialized to the broadcast address,
314  * and will be replaced with the bootparam server address
315  * after this call is complete.  Have to use PMAP_PROC_CALL
316  * to make sure we get responses only from a servers that
317  * know about us (don't want to broadcast a getport call).
318  */
319 static int
320 bp_whoami(struct sockaddr_in *bpsin, struct in_addr *my_ip,
321     struct in_addr *gw_ip)
322 {
323 	/* RPC structures for PMAPPROC_CALLIT */
324 	struct whoami_call {
325 		u_int32_t call_prog;
326 		u_int32_t call_vers;
327 		u_int32_t call_proc;
328 		u_int32_t call_arglen;
329 	} *call;
330 	struct callit_reply {
331 		u_int32_t port;
332 		u_int32_t encap_len;
333 		/* encapsulated data here */
334 	} *reply;
335 
336 	struct mbuf *m, *from;
337 	struct sockaddr_in *sin;
338 	int error, msg_len;
339 	int16_t port;
340 
341 	/*
342 	 * Build request message for PMAPPROC_CALLIT.
343 	 */
344 	m = m_get(M_WAIT, MT_DATA);
345 	call = mtod(m, struct whoami_call *);
346 	m->m_len = sizeof(*call);
347 	call->call_prog = txdr_unsigned(BOOTPARAM_PROG);
348 	call->call_vers = txdr_unsigned(BOOTPARAM_VERS);
349 	call->call_proc = txdr_unsigned(BOOTPARAM_WHOAMI);
350 
351 	/*
352 	 * append encapsulated data (client IP address)
353 	 */
354 	m->m_next = xdr_inaddr_encode(my_ip);
355 	call->call_arglen = txdr_unsigned(m->m_next->m_len);
356 
357 	/* RPC: portmap/callit */
358 	bpsin->sin_port = htons(PMAPPORT);
359 	from = NULL;
360 	error = krpc_call(bpsin, PMAPPROG, PMAPVERS,
361 			PMAPPROC_CALLIT, &m, &from, -1);
362 	if (error)
363 		return error;
364 
365 	/*
366 	 * Parse result message.
367 	 */
368 	if (m->m_len < sizeof(*reply)) {
369 		m = m_pullup(m, sizeof(*reply));
370 		if (m == NULL)
371 			goto bad;
372 	}
373 	reply = mtod(m, struct callit_reply *);
374 	port = fxdr_unsigned(u_int32_t, reply->port);
375 	msg_len = fxdr_unsigned(u_int32_t, reply->encap_len);
376 	m_adj(m, sizeof(*reply));
377 
378 	/*
379 	 * Save bootparam server address
380 	 */
381 	sin = mtod(from, struct sockaddr_in *);
382 	bpsin->sin_port = htons(port);
383 	bpsin->sin_addr.s_addr = sin->sin_addr.s_addr;
384 
385 	/* client name */
386 	hostnamelen = MAXHOSTNAMELEN-1;
387 	m = xdr_string_decode(m, hostname, &hostnamelen);
388 	if (m == NULL)
389 		goto bad;
390 
391 	/* domain name */
392 	domainnamelen = MAXHOSTNAMELEN-1;
393 	m = xdr_string_decode(m, domainname, &domainnamelen);
394 	if (m == NULL)
395 		goto bad;
396 
397 	/* gateway address */
398 	m = xdr_inaddr_decode(m, gw_ip);
399 	if (m == NULL)
400 		goto bad;
401 
402 	/* success */
403 	goto out;
404 
405 bad:
406 	printf("nfs_boot: bootparam_whoami: bad reply\n");
407 	error = EBADRPC;
408 
409 out:
410 	m_freem(from);
411 	m_freem(m);
412 	return(error);
413 }
414 
415 
416 /*
417  * RPC: bootparam/getfile
418  * Given client name and file "key", get:
419  *	server name
420  *	server IP address
421  *	server pathname
422  */
423 static int
424 bp_getfile(struct sockaddr_in *bpsin, char *key, struct sockaddr_in *md_sin,
425     char *serv_name, char *pathname, int retries)
426 {
427 	struct mbuf *m;
428 	struct sockaddr_in *sin;
429 	struct in_addr inaddr;
430 	int error, sn_len, path_len;
431 
432 	/*
433 	 * Build request message.
434 	 */
435 
436 	/* client name (hostname) */
437 	m  = xdr_string_encode(hostname, hostnamelen);
438 	if (m == NULL)
439 		return (ENOMEM);
440 
441 	/* key name (root or swap) */
442 	m->m_next = xdr_string_encode(key, strlen(key));
443 	if (m->m_next == NULL) {
444 		m_freem(m);
445 		return (ENOMEM);
446 	}
447 
448 	/* RPC: bootparam/getfile */
449 	error = krpc_call(bpsin, BOOTPARAM_PROG, BOOTPARAM_VERS,
450 			BOOTPARAM_GETFILE, &m, NULL, retries);
451 	if (error)
452 		return error;
453 
454 	/*
455 	 * Parse result message.
456 	 */
457 
458 	/* server name */
459 	sn_len = MNAMELEN-1;
460 	m = xdr_string_decode(m, serv_name, &sn_len);
461 	if (m == NULL)
462 		goto bad;
463 
464 	/* server IP address (mountd/NFS) */
465 	m = xdr_inaddr_decode(m, &inaddr);
466 	if (m == NULL)
467 		goto bad;
468 
469 	/* server pathname */
470 	path_len = MAXPATHLEN-1;
471 	m = xdr_string_decode(m, pathname, &path_len);
472 	if (m == NULL)
473 		goto bad;
474 
475 	/* setup server socket address */
476 	sin = md_sin;
477 	memset(sin, 0, sizeof(*sin));
478 	sin->sin_len = sizeof(*sin);
479 	sin->sin_family = AF_INET;
480 	sin->sin_addr = inaddr;
481 
482 	/* success */
483 	goto out;
484 
485 bad:
486 	printf("nfs_boot: bootparam_getfile: bad reply\n");
487 	error = EBADRPC;
488 
489 out:
490 	m_freem(m);
491 	return(error);
492 }
493 
494 
495 /*
496  * RPC: mountd/mount
497  * Given a server pathname, get an NFS file handle.
498  * Also, sets sin->sin_port to the NFS service port.
499  * mdsin:	mountd server address
500  */
501 static int
502 md_mount(struct sockaddr_in *mdsin, char *path, struct nfs_args *argp)
503 {
504 	/* The RPC structures */
505 	struct rdata {
506 		u_int32_t errno;
507 		union {
508 			u_int8_t v2fh[NFSX_V2FH];
509 			struct {
510 				u_int32_t fhlen;
511 				u_int8_t fh[1];
512 			} v3fh;
513 		} fh;
514 	} *rdata;
515 	struct mbuf *m;
516 	u_int8_t *fh;
517 	int minlen, error;
518 	int mntver;
519 
520 	mntver = (argp->flags & NFSMNT_NFSV3) ? 3 : 2;
521 	do {
522 		error = krpc_portmap(mdsin, RPCPROG_MNT, mntver,
523 		    &mdsin->sin_port);
524 		if (error)
525 			continue;
526 
527 		m = xdr_string_encode(path, strlen(path));
528 		if (m == NULL)
529 			return ENOMEM;
530 
531 		/* Do RPC to mountd. */
532 		error = krpc_call(mdsin, RPCPROG_MNT, mntver,
533 		    RPCMNT_MOUNT, &m, NULL, -1);
534 
535 		if (error != EPROGMISMATCH)
536 			break;
537 		/* Try lower version of mountd. */
538 	} while (--mntver >= 1);
539 	if (error)
540 		return error;	/* message already freed */
541 
542 	if (mntver != 3)
543 		argp->flags &= ~NFSMNT_NFSV3;
544 
545 	/* The reply might have only the errno. */
546 	if (m->m_len < 4)
547 		goto bad;
548 	/* Have at least errno, so check that. */
549 	rdata = mtod(m, struct rdata *);
550 	error = fxdr_unsigned(u_int32_t, rdata->errno);
551 	if (error)
552 		goto out;
553 
554 	 /* Have errno==0, so the fh must be there. */
555 	if (mntver == 3) {
556 		argp->fhsize = fxdr_unsigned(u_int32_t, rdata->fh.v3fh.fhlen);
557 		if (argp->fhsize > NFSX_V3FHMAX)
558 			goto bad;
559 		minlen = 2 * sizeof(u_int32_t) + argp->fhsize;
560 	} else {
561 		argp->fhsize = NFSX_V2FH;
562 		minlen = sizeof(u_int32_t) + argp->fhsize;
563 	}
564 
565 	if (m->m_len < minlen) {
566 		m = m_pullup(m, minlen);
567 		if (m == NULL)
568 			return (EBADRPC);
569 		rdata = mtod(m, struct rdata *);
570 	}
571 
572 	fh = (mntver == 3) ? rdata->fh.v3fh.fh : rdata->fh.v2fh;
573 	bcopy(fh, argp->fh, argp->fhsize);
574 
575 	goto out;
576 
577 bad:
578 	error = EBADRPC;
579 
580 out:
581 	m_freem(m);
582 	return error;
583 }
584 
585 #endif /* ifdef NFSCLIENT */
586