1 /* $NetBSD: nfs_boot.c,v 1.90 2024/07/05 04:31:54 rin 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 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 /*
33 * Support for NFS diskless booting, specifically getting information
34 * about where to mount root from, what pathnames, etc.
35 */
36
37 #include <sys/cdefs.h>
38 __KERNEL_RCSID(0, "$NetBSD: nfs_boot.c,v 1.90 2024/07/05 04:31:54 rin Exp $");
39
40 #ifdef _KERNEL_OPT
41 #include "opt_nfs.h"
42 #include "opt_tftproot.h"
43 #include "opt_nfs_boot.h"
44 #endif
45
46 #ifdef NFS_BOOT_TCP
47 #undef NFS_BOOT_UDP
48 #endif
49
50 #include <sys/param.h>
51 #include <sys/systm.h>
52 #include <sys/kernel.h>
53 #include <sys/device.h>
54 #include <sys/ioctl.h>
55 #include <sys/proc.h>
56 #include <sys/mount.h>
57 #include <sys/mbuf.h>
58 #include <sys/reboot.h>
59 #include <sys/socket.h>
60 #include <sys/socketvar.h>
61
62 #include <net/if.h>
63 #include <net/route.h>
64 #include <net/if_ether.h>
65 #include <net/if_types.h>
66
67 #include <netinet/in.h>
68 #include <netinet/if_inarp.h>
69
70 #include <nfs/rpcv2.h>
71 #include <nfs/krpc.h>
72 #include <nfs/xdr_subs.h>
73
74 #include <nfs/nfsproto.h>
75 #include <nfs/nfs.h>
76 #include <nfs/nfsmount.h>
77 #include <nfs/nfsdiskless.h>
78
79 /*
80 * There are three implementations of NFS diskless boot.
81 * One implementation uses BOOTP (RFC951, RFC1048),
82 * Sun RPC/bootparams or static configuration. See the
83 * files:
84 * nfs_bootdhcp.c: BOOTP (RFC951, RFC1048)
85 * nfs_bootparam.c: Sun RPC/bootparams
86 * nfs_bootstatic.c: honour config(1) description
87 */
88 #if defined(NFS_BOOT_BOOTP) || defined(NFS_BOOT_DHCP)
89 int nfs_boot_rfc951 = 1; /* BOOTP enabled (default) */
90 #endif
91 #ifdef NFS_BOOT_BOOTPARAM
92 int nfs_boot_bootparam = 1; /* BOOTPARAM enabled (default) */
93 #endif
94 #ifdef NFS_BOOT_BOOTSTATIC
95 int nfs_boot_bootstatic = 1; /* BOOTSTATIC enabled (default) */
96 #endif
97
98 #define IP_MIN_MTU 576
99
100 /* mountd RPC */
101 static int md_mount(struct sockaddr_in *mdsin, char *path,
102 struct nfs_args *argp, struct lwp *l);
103
104 static int nfs_boot_delroute_matcher(struct rtentry *, void *);
105 static void nfs_boot_defrt(struct in_addr *);
106 static int nfs_boot_getfh(struct nfs_dlmount *ndm, struct lwp *);
107
108
109 /*
110 * Called with an empty nfs_diskless struct to be filled in.
111 * Find an interface, determine its ip address (etc.) and
112 * save all the boot parameters in the nfs_diskless struct.
113 */
114 int
nfs_boot_init(struct nfs_diskless * nd,struct lwp * lwp)115 nfs_boot_init(struct nfs_diskless *nd, struct lwp *lwp)
116 {
117 struct ifnet *ifp;
118 int error = 0;
119 int flags __unused;
120
121 /* Explicitly necessary or build fails
122 * due to unused variable, otherwise.
123 */
124 flags = 0;
125
126 /*
127 * Find the network interface.
128 */
129 ifp = ifunit(device_xname(root_device));
130 if (ifp == NULL) {
131 printf("nfs_boot: '%s' not found\n",
132 device_xname(root_device));
133 return (ENXIO);
134 }
135 nd->nd_ifp = ifp;
136
137 error = EADDRNOTAVAIL; /* ??? */
138 #if defined(NFS_BOOT_BOOTSTATIC)
139 if (error && nfs_boot_bootstatic) {
140 printf("nfs_boot: trying static\n");
141 error = nfs_bootstatic(nd, lwp, &flags);
142 }
143 #endif
144 #if defined(NFS_BOOT_BOOTP) || defined(NFS_BOOT_DHCP)
145 if (error && nfs_boot_rfc951) {
146 #if defined(NFS_BOOT_DHCP)
147 printf("nfs_boot: trying DHCP/BOOTP\n");
148 #else
149 printf("nfs_boot: trying BOOTP\n");
150 #endif
151 error = nfs_bootdhcp(nd, lwp, &flags);
152 }
153 #endif
154 #ifdef NFS_BOOT_BOOTPARAM
155 if (error && nfs_boot_bootparam) {
156 printf("nfs_boot: trying RARP (and RPC/bootparam)\n");
157 error = nfs_bootparam(nd, lwp, &flags);
158 }
159 #endif
160 if (error)
161 return (error);
162
163 /*
164 * Set MTU if passed
165 */
166 if (nd->nd_mtu >= IP_MIN_MTU )
167 nfs_boot_setmtu(nd->nd_ifp, nd->nd_mtu, lwp);
168
169 /*
170 * If the gateway address is set, add a default route.
171 * (The mountd RPCs may go across a gateway.)
172 */
173 if (nd->nd_gwip.s_addr)
174 nfs_boot_defrt(&nd->nd_gwip);
175
176 #ifdef TFTPROOT
177 if (nd->nd_nomount)
178 goto out;
179 #endif
180 /*
181 * Now fetch the NFS file handles as appropriate.
182 */
183 error = nfs_boot_getfh(&nd->nd_root, lwp);
184
185 if (error)
186 nfs_boot_cleanup(nd, lwp);
187
188 #ifdef TFTPROOT
189 out:
190 #endif
191 return (error);
192 }
193
194 void
nfs_boot_cleanup(struct nfs_diskless * nd,struct lwp * lwp)195 nfs_boot_cleanup(struct nfs_diskless *nd, struct lwp *lwp)
196 {
197
198 nfs_boot_deladdress(nd->nd_ifp, lwp, nd->nd_myip.s_addr);
199 nfs_boot_ifupdown(nd->nd_ifp, lwp, 0);
200 nfs_boot_flushrt(nd->nd_ifp);
201 }
202
203 int
nfs_boot_ifupdown(struct ifnet * ifp,struct lwp * lwp,int up)204 nfs_boot_ifupdown(struct ifnet *ifp, struct lwp *lwp, int up)
205 {
206 struct socket *so;
207 struct ifreq ireq;
208 int error;
209
210 memset(&ireq, 0, sizeof(ireq));
211 memcpy(ireq.ifr_name, ifp->if_xname, IFNAMSIZ);
212
213 /*
214 * Get a socket to use for various things in here.
215 * After this, use "goto out" to cleanup and return.
216 */
217 error = socreate(AF_INET, &so, SOCK_DGRAM, 0, lwp, NULL);
218 if (error) {
219 printf("ifupdown: socreate, error=%d\n", error);
220 return (error);
221 }
222
223 /*
224 * Bring up the interface. (just set the "up" flag)
225 * Get the old interface flags and or IFF_UP into them so
226 * things like media selection flags are not clobbered.
227 */
228 error = ifioctl(so, SIOCGIFFLAGS, (void *)&ireq, lwp);
229 if (error) {
230 printf("ifupdown: GIFFLAGS, error=%d\n", error);
231 goto out;
232 }
233 if (up)
234 ireq.ifr_flags |= IFF_UP;
235 else
236 ireq.ifr_flags &= ~IFF_UP;
237 error = ifioctl(so, SIOCSIFFLAGS, &ireq, lwp);
238 if (error) {
239 printf("ifupdown: SIFFLAGS, error=%d\n", error);
240 goto out;
241 }
242
243 if (up)
244 /* give the link some time to get up */
245 tsleep(nfs_boot_ifupdown, PZERO, "nfsbif", 3 * hz);
246 out:
247 soclose(so);
248 return (error);
249 }
250
251 void
nfs_boot_setmtu(struct ifnet * ifp,int mtu,struct lwp * lwp)252 nfs_boot_setmtu(struct ifnet *ifp, int mtu, struct lwp *lwp)
253 {
254 struct socket *so;
255 struct ifreq ireq;
256 int error;
257
258 memset(&ireq, 0, sizeof(ireq));
259 memcpy(ireq.ifr_name, ifp->if_xname, IFNAMSIZ);
260
261 /*
262 * Get a socket to use for various things in here.
263 * After this, use "goto out" to cleanup and return.
264 */
265 error = socreate(AF_INET, &so, SOCK_DGRAM, 0, lwp, NULL);
266 if (error) {
267 printf("setmtu: socreate, error=%d\n", error);
268 return;
269 }
270
271 /*
272 * Get structure, set the new MTU, push structure.
273 */
274 error = ifioctl(so, SIOCGIFMTU, (void *)&ireq, lwp);
275 if (error) {
276 printf("setmtu: GIFMTU, error=%d\n", error);
277 goto out;
278 }
279
280 ireq.ifr_mtu = mtu;
281
282 error = ifioctl(so, SIOCSIFMTU, &ireq, lwp);
283 if (error) {
284 printf("setmtu: SIFMTU, error=%d\n", error);
285 goto out;
286 }
287
288 out:
289 soclose(so);
290 return;
291 }
292
293 int
nfs_boot_setaddress(struct ifnet * ifp,struct lwp * lwp,uint32_t addr,uint32_t netmask,uint32_t braddr)294 nfs_boot_setaddress(struct ifnet *ifp, struct lwp *lwp,
295 uint32_t addr, uint32_t netmask, uint32_t braddr)
296 {
297 struct socket *so;
298 struct ifaliasreq iareq;
299 struct sockaddr_in *sin;
300 int error;
301
302 /*
303 * Get a socket to use for various things in here.
304 * After this, use "goto out" to cleanup and return.
305 */
306 error = socreate(AF_INET, &so, SOCK_DGRAM, 0, lwp, NULL);
307 if (error) {
308 printf("setaddress: socreate, error=%d\n", error);
309 return (error);
310 }
311
312 memset(&iareq, 0, sizeof(iareq));
313 memcpy(iareq.ifra_name, ifp->if_xname, IFNAMSIZ);
314
315 /* Set the I/F address */
316 sin = (struct sockaddr_in *)&iareq.ifra_addr;
317 sin->sin_len = sizeof(*sin);
318 sin->sin_family = AF_INET;
319 sin->sin_addr.s_addr = addr;
320
321 /* Set the netmask */
322 if (netmask != INADDR_ANY) {
323 sin = (struct sockaddr_in *)&iareq.ifra_mask;
324 sin->sin_len = sizeof(*sin);
325 sin->sin_family = AF_INET;
326 sin->sin_addr.s_addr = netmask;
327 } /* else leave subnetmask unspecified (len=0) */
328
329 /* Set the broadcast addr. */
330 if (braddr != INADDR_ANY) {
331 sin = (struct sockaddr_in *)&iareq.ifra_broadaddr;
332 sin->sin_len = sizeof(*sin);
333 sin->sin_family = AF_INET;
334 sin->sin_addr.s_addr = braddr;
335 } /* else leave broadcast addr unspecified (len=0) */
336
337 error = ifioctl(so, SIOCAIFADDR, (void *)&iareq, lwp);
338 if (error) {
339 printf("setaddress, error=%d\n", error);
340 goto out;
341 }
342
343 /* give the link some time to get up */
344 tsleep(nfs_boot_setaddress, PZERO, "nfsbtd", 3 * hz);
345 out:
346 soclose(so);
347 return (error);
348 }
349
350 int
nfs_boot_deladdress(struct ifnet * ifp,struct lwp * lwp,uint32_t addr)351 nfs_boot_deladdress(struct ifnet *ifp, struct lwp *lwp, uint32_t addr)
352 {
353 struct socket *so;
354 struct ifreq ifr;
355 struct sockaddr_in sin;
356 struct in_addr ia = {.s_addr = addr};
357 int error;
358
359 /*
360 * Get a socket to use for various things in here.
361 * After this, use "goto out" to cleanup and return.
362 */
363 error = socreate(AF_INET, &so, SOCK_DGRAM, 0, lwp, NULL);
364 if (error) {
365 printf("deladdress: socreate, error=%d\n", error);
366 return (error);
367 }
368
369 memset(&ifr, 0, sizeof(ifr));
370 memcpy(ifr.ifr_name, ifp->if_xname, IFNAMSIZ);
371
372 sockaddr_in_init(&sin, &ia, 0);
373 ifreq_setaddr(SIOCDIFADDR, &ifr, sintocsa(&sin));
374
375 error = ifioctl(so, SIOCDIFADDR, &ifr, lwp);
376 if (error) {
377 printf("deladdress, error=%d\n", error);
378 goto out;
379 }
380
381 out:
382 soclose(so);
383 return (error);
384 }
385
386 int
nfs_boot_setrecvtimo(struct socket * so)387 nfs_boot_setrecvtimo(struct socket *so)
388 {
389 struct timeval tv;
390
391 tv.tv_sec = 1;
392 tv.tv_usec = 0;
393
394 return (so_setsockopt(NULL, so, SOL_SOCKET, SO_RCVTIMEO, &tv,
395 sizeof(tv)));
396 }
397
398 int
nfs_boot_enbroadcast(struct socket * so)399 nfs_boot_enbroadcast(struct socket *so)
400 {
401 int32_t on;
402
403 on = 1;
404 return (so_setsockopt(NULL, so, SOL_SOCKET, SO_BROADCAST, &on,
405 sizeof(on)));
406 }
407
408 int
nfs_boot_sobind_ipport(struct socket * so,uint16_t port,struct lwp * l)409 nfs_boot_sobind_ipport(struct socket *so, uint16_t port, struct lwp *l)
410 {
411 struct sockaddr_in sin;
412 int error;
413
414 sin.sin_len = sizeof(sin);
415 sin.sin_family = AF_INET;
416 sin.sin_addr.s_addr = INADDR_ANY;
417 sin.sin_port = htons(port);
418 error = sobind(so, (struct sockaddr *)&sin, l);
419 return (error);
420 }
421
422 /*
423 * What is the longest we will wait before re-sending a request?
424 * Note this is also the frequency of "timeout" messages.
425 * The re-send loop counts up linearly to this maximum, so the
426 * first complaint will happen after (1+2+3+4+5)=15 seconds.
427 */
428 #define MAX_RESEND_DELAY 5 /* seconds */
429 #define TOTAL_TIMEOUT 30 /* seconds */
430
431 int
nfs_boot_sendrecv(struct socket * so,struct sockaddr_in * nam,int (* sndproc)(struct mbuf *,void *,int),struct mbuf * snd,int (* rcvproc)(struct mbuf **,void *),struct mbuf ** rcv,struct mbuf ** from_p,void * context,struct lwp * lwp)432 nfs_boot_sendrecv(struct socket *so, struct sockaddr_in *nam,
433 int (*sndproc)(struct mbuf *, void *, int),
434 struct mbuf *snd,
435 int (*rcvproc)(struct mbuf **, void *),
436 struct mbuf **rcv, struct mbuf **from_p,
437 void *context, struct lwp *lwp)
438 {
439 int error, rcvflg, timo, secs, waited;
440 struct mbuf *m, *from;
441 struct uio uio;
442
443 /* Free at end if not null. */
444 from = NULL;
445
446 /*
447 * Send it, repeatedly, until a reply is received,
448 * but delay each re-send by an increasing amount.
449 * If the delay hits the maximum, start complaining.
450 */
451 waited = timo = 0;
452 send_again:
453 waited += timo;
454 if (waited >= TOTAL_TIMEOUT)
455 return (ETIMEDOUT);
456
457 /* Determine new timeout. */
458 if (timo < MAX_RESEND_DELAY)
459 timo++;
460 else
461 printf("nfs_boot: timeout...\n");
462
463 if (sndproc) {
464 error = (*sndproc)(snd, context, waited);
465 if (error)
466 goto out;
467 }
468
469 /* Send request (or re-send). */
470 m = m_copypacket(snd, M_WAIT);
471 if (m == NULL) {
472 error = ENOBUFS;
473 goto out;
474 }
475 error = (*so->so_send)(so, (struct sockaddr *)nam, NULL,
476 m, NULL, 0, lwp);
477 if (error) {
478 printf("nfs_boot: sosend: %d\n", error);
479 goto out;
480 }
481 m = NULL;
482
483 /*
484 * Wait for up to timo seconds for a reply.
485 * The socket receive timeout was set to 1 second.
486 */
487
488 secs = timo;
489 for (;;) {
490 m_freem(from);
491 from = NULL;
492 m_freem(m);
493 m = NULL;
494 uio.uio_resid = 1 << 16; /* ??? */
495 rcvflg = 0;
496 error = (*so->so_receive)(so, &from, &uio, &m, NULL, &rcvflg);
497 if (error == EWOULDBLOCK) {
498 if (--secs <= 0)
499 goto send_again;
500 continue;
501 }
502 if (error)
503 goto out;
504 #ifdef DIAGNOSTIC
505 if (!m || !(m->m_flags & M_PKTHDR)
506 || (1 << 16) - uio.uio_resid != m->m_pkthdr.len)
507 panic("nfs_boot_sendrecv: return size");
508 #endif
509
510 if ((*rcvproc)(&m, context))
511 continue;
512
513 if (rcv)
514 *rcv = m;
515 else
516 m_freem(m);
517 if (from_p) {
518 *from_p = from;
519 from = NULL;
520 }
521 break;
522 }
523 out:
524 m_freem(from);
525 return (error);
526 }
527
528 /*
529 * Install a default route to the passed IP address.
530 */
531 static void
nfs_boot_defrt(struct in_addr * gw_ip)532 nfs_boot_defrt(struct in_addr *gw_ip)
533 {
534 struct sockaddr dst, gw, mask;
535 struct sockaddr_in *sin;
536 int error;
537
538 /* Destination: (default) */
539 memset((void *)&dst, 0, sizeof(dst));
540 dst.sa_len = sizeof(dst);
541 dst.sa_family = AF_INET;
542 /* Gateway: */
543 memset((void *)&gw, 0, sizeof(gw));
544 sin = (struct sockaddr_in *)&gw;
545 sin->sin_len = sizeof(*sin);
546 sin->sin_family = AF_INET;
547 sin->sin_addr.s_addr = gw_ip->s_addr;
548 /* Mask: (zero length) */
549 /* XXX - Just pass a null pointer? */
550 memset(&mask, 0, sizeof(mask));
551
552 /* add, dest, gw, mask, flags, 0 */
553 error = rtrequest(RTM_ADD, &dst, &gw, &mask,
554 (RTF_UP | RTF_GATEWAY | RTF_STATIC), NULL);
555 if (error) {
556 printf("nfs_boot: add route, error=%d\n", error);
557 error = 0;
558 }
559 }
560
561 static int
nfs_boot_delroute_matcher(struct rtentry * rt,void * w)562 nfs_boot_delroute_matcher(struct rtentry *rt, void *w)
563 {
564
565 if ((void *)rt->rt_ifp != w)
566 return 0;
567
568 return 1;
569 }
570
571 void
nfs_boot_flushrt(struct ifnet * ifp)572 nfs_boot_flushrt(struct ifnet *ifp)
573 {
574
575 rt_delete_matched_entries(AF_INET, nfs_boot_delroute_matcher, ifp, false);
576 }
577
578 /*
579 * Get an initial NFS file handle using Sun RPC/mountd.
580 * Separate function because we used to call it twice.
581 * (once for root and once for swap)
582 *
583 * ndm output
584 */
585 static int
nfs_boot_getfh(struct nfs_dlmount * ndm,struct lwp * l)586 nfs_boot_getfh(struct nfs_dlmount *ndm, struct lwp *l)
587 {
588 struct nfs_args *args;
589 struct sockaddr_in *sin;
590 char *pathname;
591 int error;
592 u_int16_t port;
593
594 args = &ndm->ndm_args;
595
596 /* Initialize mount args. */
597 memset((void *) args, 0, sizeof(*args));
598 args->addr = &ndm->ndm_saddr;
599 args->addrlen = args->addr->sa_len;
600 #ifdef NFS_BOOT_UDP
601 args->sotype = SOCK_DGRAM;
602 #else
603 args->sotype = SOCK_STREAM;
604 #endif
605 args->fh = ndm->ndm_fh;
606 args->hostname = ndm->ndm_host;
607 args->flags = NFSMNT_NOCONN | NFSMNT_RESVPORT;
608
609 #ifndef NFS_V2_ONLY
610 args->flags |= NFSMNT_NFSV3;
611 #endif
612 #ifdef NFS_BOOT_OPTIONS
613 args->flags |= NFS_BOOT_OPTIONS;
614 #endif
615 #ifdef NFS_BOOT_RWSIZE
616 /*
617 * Reduce rsize,wsize for interfaces that consistently
618 * drop fragments of long UDP messages. (i.e. wd8003).
619 * You can always change these later via remount.
620 */
621 args->flags |= NFSMNT_WSIZE | NFSMNT_RSIZE;
622 args->wsize = NFS_BOOT_RWSIZE;
623 args->rsize = NFS_BOOT_RWSIZE;
624 #endif
625
626 /*
627 * Find the pathname part of the "server:pathname"
628 * string left in ndm->ndm_host by nfs_boot_init.
629 */
630 pathname = strchr(ndm->ndm_host, ':');
631 if (pathname == 0) {
632 printf("nfs_boot: getfh - no pathname\n");
633 return (EIO);
634 }
635 pathname++;
636
637 /*
638 * Get file handle using RPC to mountd/mount
639 */
640 sin = (struct sockaddr_in *)&ndm->ndm_saddr;
641 error = md_mount(sin, pathname, args, l);
642 if (error) {
643 printf("nfs_boot: mountd `%s', error=%d\n",
644 ndm->ndm_host, error);
645 return (error);
646 }
647
648 /* Set port number for NFS use. */
649 /* XXX: NFS port is always 2049, right? */
650 retry:
651 error = krpc_portmap(sin, NFS_PROG,
652 (args->flags & NFSMNT_NFSV3) ? NFS_VER3 : NFS_VER2,
653 (args->sotype == SOCK_STREAM) ? IPPROTO_TCP : IPPROTO_UDP,
654 &port, l);
655 if (port == htons(0))
656 error = EIO;
657 if (error) {
658 if (args->sotype == SOCK_STREAM) {
659 args->sotype = SOCK_DGRAM;
660 goto retry;
661 }
662 printf("nfs_boot: portmap NFS, error=%d\n", error);
663 return (error);
664 }
665 sin->sin_port = port;
666 return (0);
667 }
668
669
670 /*
671 * RPC: mountd/mount
672 * Given a server pathname, get an NFS file handle.
673 * Also, sets sin->sin_port to the NFS service port.
674 *
675 * mdsin mountd server address
676 */
677 static int
md_mount(struct sockaddr_in * mdsin,char * path,struct nfs_args * argp,struct lwp * lwp)678 md_mount(struct sockaddr_in *mdsin, char *path,
679 struct nfs_args *argp, struct lwp *lwp)
680 {
681 /* The RPC structures */
682 struct rdata {
683 u_int32_t errno;
684 union {
685 u_int8_t v2fh[NFSX_V2FH];
686 struct {
687 u_int32_t fhlen;
688 u_int8_t fh[1];
689 } v3fh;
690 } fh;
691 } *rdata;
692 struct mbuf *m;
693 u_int8_t *fh;
694 int minlen, error;
695 int mntver;
696
697 mntver = (argp->flags & NFSMNT_NFSV3) ? 3 : 2;
698 do {
699 /*
700 * Get port number for MOUNTD.
701 */
702 error = krpc_portmap(mdsin, RPCPROG_MNT, mntver,
703 IPPROTO_UDP, &mdsin->sin_port, lwp);
704 if (error)
705 continue;
706
707 /* This mbuf is consumed by krpc_call. */
708 m = xdr_string_encode(path, strlen(path));
709 if (m == NULL)
710 return ENOMEM;
711
712 /* Do RPC to mountd. */
713 error = krpc_call(mdsin, RPCPROG_MNT, mntver,
714 RPCMNT_MOUNT, &m, NULL, lwp);
715 if (error != EPROGMISMATCH)
716 break;
717 /* Try lower version of mountd. */
718 } while (--mntver >= 1);
719 if (error) {
720 printf("nfs_boot: mountd error=%d\n", error);
721 return error;
722 }
723 if (mntver != 3)
724 argp->flags &= ~NFSMNT_NFSV3;
725
726 /* The reply might have only the errno. */
727 if (m->m_len < 4)
728 goto bad;
729 /* Have at least errno, so check that. */
730 rdata = mtod(m, struct rdata *);
731 error = fxdr_unsigned(u_int32_t, rdata->errno);
732 if (error)
733 goto out;
734
735 /* Have errno==0, so the fh must be there. */
736 if (mntver == 3) {
737 argp->fhsize = fxdr_unsigned(u_int32_t, rdata->fh.v3fh.fhlen);
738 if (argp->fhsize > NFSX_V3FHMAX)
739 goto bad;
740 minlen = 2 * sizeof(u_int32_t) + argp->fhsize;
741 } else {
742 argp->fhsize = NFSX_V2FH;
743 minlen = sizeof(u_int32_t) + argp->fhsize;
744 }
745
746 if (m->m_len < minlen) {
747 m = m_pullup(m, minlen);
748 if (m == NULL)
749 return(EBADRPC);
750 rdata = mtod(m, struct rdata *);
751 }
752
753 fh = (mntver == 3) ?
754 rdata->fh.v3fh.fh : rdata->fh.v2fh;
755 memcpy(argp->fh, fh, argp->fhsize);
756
757 goto out;
758
759 bad:
760 error = EBADRPC;
761
762 out:
763 m_freem(m);
764 return error;
765 }
766