xref: /freebsd/sys/nfs/nfs_diskless.c (revision b0d29bc47dba79f6f38e67eabadfb4b32ffd9390)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1990 The Regents of the University of California.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * William Jolitz.
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. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  *	from: @(#)autoconf.c	7.1 (Berkeley) 5/9/91
35  */
36 
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
39 
40 #include "opt_bootp.h"
41 
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/jail.h>
45 #include <sys/kernel.h>
46 #include <sys/malloc.h>
47 #include <sys/mount.h>
48 #include <sys/socket.h>
49 
50 #include <net/if.h>
51 #include <net/if_dl.h>
52 #include <net/if_types.h>
53 #include <net/if_var.h>
54 #include <net/ethernet.h>
55 #include <net/vnet.h>
56 
57 #include <netinet/in.h>
58 #include <nfs/nfsproto.h>
59 #include <nfsclient/nfs.h>
60 #include <nfs/nfsdiskless.h>
61 
62 #define	NFS_IFACE_TIMEOUT_SECS	10 /* Timeout for interface to appear. */
63 
64 static int inaddr_to_sockaddr(char *ev, struct sockaddr_in *sa);
65 static int hwaddr_to_sockaddr(char *ev, struct sockaddr_dl *sa);
66 static int decode_nfshandle(char *ev, u_char *fh, int maxfh);
67 
68 /*
69  * This structure must be filled in by a primary bootstrap or bootstrap
70  * server for a diskless/dataless machine. It is initialized below just
71  * to ensure that it is allocated to initialized data (.data not .bss).
72  */
73 struct nfs_diskless	nfs_diskless = { { { 0 } } };
74 struct nfsv3_diskless	nfsv3_diskless = { { { 0 } } };
75 int			nfs_diskless_valid = 0;
76 
77 /*
78  * Validate/sanity check a rsize/wsize parameter.
79  */
80 static int
81 checkrwsize(unsigned long v, const char *name)
82 {
83 	/*
84 	 * 32K is used as an upper bound because most servers
85 	 * limit block size to satisfy IPv4's limit of
86 	 * 64K/reassembled packet.  The lower bound is pretty
87 	 * much arbitrary.
88 	 */
89 	if (!(4 <= v && v <= 32*1024)) {
90 		printf("nfs_parse_options: invalid %s %lu ignored\n", name, v);
91 		return 0;
92 	} else
93 		return 1;
94 }
95 
96 /*
97  * Parse mount options and apply them to the supplied
98  * nfs_diskless state.  Used also by bootp/dhcp support.
99  */
100 void
101 nfs_parse_options(const char *envopts, struct nfs_args *nd)
102 {
103 	char *opts, *o, *otmp;
104 	unsigned long v;
105 
106 	opts = strdup(envopts, M_TEMP);
107 	otmp = opts;
108 	while ((o = strsep(&otmp, ":;, ")) != NULL) {
109 		if (*o == '\0')
110 			; /* Skip empty options. */
111 		else if (strcmp(o, "soft") == 0)
112 			nd->flags |= NFSMNT_SOFT;
113 		else if (strcmp(o, "intr") == 0)
114 			nd->flags |= NFSMNT_INT;
115 		else if (strcmp(o, "conn") == 0)
116 			nd->flags |= NFSMNT_NOCONN;
117 		else if (strcmp(o, "nolockd") == 0)
118 			nd->flags |= NFSMNT_NOLOCKD;
119 		else if (strcmp(o, "nocto") == 0)
120 			nd->flags |= NFSMNT_NOCTO;
121 		else if (strcmp(o, "nfsv2") == 0)
122 			nd->flags &= ~(NFSMNT_NFSV3 | NFSMNT_NFSV4);
123 		else if (strcmp(o, "nfsv3") == 0) {
124 			nd->flags &= ~NFSMNT_NFSV4;
125 			nd->flags |= NFSMNT_NFSV3;
126 		} else if (strcmp(o, "tcp") == 0)
127 			nd->sotype = SOCK_STREAM;
128 		else if (strcmp(o, "udp") == 0)
129 			nd->sotype = SOCK_DGRAM;
130 		else if (strncmp(o, "rsize=", 6) == 0) {
131 			v = strtoul(o+6, NULL, 10);
132 			if (checkrwsize(v, "rsize")) {
133 				nd->rsize = (int) v;
134 				nd->flags |= NFSMNT_RSIZE;
135 			}
136 		} else if (strncmp(o, "wsize=", 6) == 0) {
137 			v = strtoul(o+6, NULL, 10);
138 			if (checkrwsize(v, "wsize")) {
139 				nd->wsize = (int) v;
140 				nd->flags |= NFSMNT_WSIZE;
141 			}
142 		} else
143 			printf("%s: skipping unknown option \"%s\"\n",
144 			    __func__, o);
145 	}
146 	free(opts, M_TEMP);
147 }
148 
149 /*
150  * Populate the essential fields in the nfsv3_diskless structure.
151  *
152  * The loader is expected to export the following environment variables:
153  *
154  * boot.netif.name		name of boot interface
155  * boot.netif.ip		IP address on boot interface
156  * boot.netif.netmask		netmask on boot interface
157  * boot.netif.gateway		default gateway (optional)
158  * boot.netif.hwaddr		hardware address of boot interface
159  * boot.netif.mtu		interface mtu from bootp/dhcp (optional)
160  * boot.nfsroot.server		IP address of root filesystem server
161  * boot.nfsroot.path		path of the root filesystem on server
162  * boot.nfsroot.nfshandle	NFS handle for root filesystem on server
163  * boot.nfsroot.nfshandlelen	and length of this handle (for NFSv3 only)
164  * boot.nfsroot.options		NFS options for the root filesystem
165  */
166 void
167 nfs_setup_diskless(void)
168 {
169 	struct nfs_diskless *nd = &nfs_diskless;
170 	struct nfsv3_diskless *nd3 = &nfsv3_diskless;
171 	struct ifnet *ifp;
172 	struct ifaddr *ifa;
173 	struct sockaddr_dl *sdl, ourdl;
174 	struct sockaddr_in myaddr, netmask;
175 	char *cp;
176 	int cnt, fhlen, is_nfsv3;
177 	uint32_t len;
178 	time_t timeout_at;
179 
180 	if (nfs_diskless_valid != 0)
181 		return;
182 
183 	/* get handle size. If this succeeds, it's an NFSv3 setup. */
184 	if ((cp = kern_getenv("boot.nfsroot.nfshandlelen")) != NULL) {
185 		cnt = sscanf(cp, "%d", &len);
186 		freeenv(cp);
187 		if (cnt != 1 || len == 0 || len > NFSX_V3FHMAX) {
188 			printf("nfs_diskless: bad NFS handle len\n");
189 			return;
190 		}
191 		nd3->root_fhsize = len;
192 		is_nfsv3 = 1;
193 	} else
194 		is_nfsv3 = 0;
195 	/* set up interface */
196 	if (inaddr_to_sockaddr("boot.netif.ip", &myaddr))
197 		return;
198 	if (inaddr_to_sockaddr("boot.netif.netmask", &netmask)) {
199 		printf("nfs_diskless: no netmask\n");
200 		return;
201 	}
202 	if (is_nfsv3 != 0) {
203 		bcopy(&myaddr, &nd3->myif.ifra_addr, sizeof(myaddr));
204 		bcopy(&myaddr, &nd3->myif.ifra_broadaddr, sizeof(myaddr));
205 		((struct sockaddr_in *)
206 		   &nd3->myif.ifra_broadaddr)->sin_addr.s_addr =
207 		    myaddr.sin_addr.s_addr | ~ netmask.sin_addr.s_addr;
208 		bcopy(&netmask, &nd3->myif.ifra_mask, sizeof(netmask));
209 	} else {
210 		bcopy(&myaddr, &nd->myif.ifra_addr, sizeof(myaddr));
211 		bcopy(&myaddr, &nd->myif.ifra_broadaddr, sizeof(myaddr));
212 		((struct sockaddr_in *)
213 		   &nd->myif.ifra_broadaddr)->sin_addr.s_addr =
214 		    myaddr.sin_addr.s_addr | ~ netmask.sin_addr.s_addr;
215 		bcopy(&netmask, &nd->myif.ifra_mask, sizeof(netmask));
216 	}
217 
218 	if (hwaddr_to_sockaddr("boot.netif.hwaddr", &ourdl)) {
219 		printf("nfs_diskless: no hardware address\n");
220 		return;
221 	}
222 	ifa = NULL;
223 	timeout_at = time_uptime + NFS_IFACE_TIMEOUT_SECS;
224 retry:
225 	CURVNET_SET(TD_TO_VNET(curthread));
226 	IFNET_RLOCK();
227 	CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) {
228 		CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
229 			if (ifa->ifa_addr->sa_family == AF_LINK) {
230 				sdl = (struct sockaddr_dl *)ifa->ifa_addr;
231 				if ((sdl->sdl_type == ourdl.sdl_type) &&
232 				    (sdl->sdl_alen == ourdl.sdl_alen) &&
233 				    !bcmp(LLADDR(sdl),
234 					  LLADDR(&ourdl),
235 					  sdl->sdl_alen)) {
236 				    IFNET_RUNLOCK();
237 				    CURVNET_RESTORE();
238 				    goto match_done;
239 				}
240 			}
241 		}
242 	}
243 	IFNET_RUNLOCK();
244 	CURVNET_RESTORE();
245 	if (time_uptime < timeout_at) {
246 		pause("nfssdl", hz / 5);
247 		goto retry;
248 	}
249 	printf("nfs_diskless: no interface\n");
250 	return;	/* no matching interface */
251 match_done:
252 	kern_setenv("boot.netif.name", ifp->if_xname);
253 	if (is_nfsv3 != 0) {
254 		strlcpy(nd3->myif.ifra_name, ifp->if_xname,
255 		    sizeof(nd3->myif.ifra_name));
256 
257 		/* set up gateway */
258 		inaddr_to_sockaddr("boot.netif.gateway", &nd3->mygateway);
259 
260 		/* set up root mount */
261 		nd3->root_args.rsize = 32768;		/* XXX tunable? */
262 		nd3->root_args.wsize = 32768;
263 		nd3->root_args.sotype = SOCK_STREAM;
264 		nd3->root_args.flags = (NFSMNT_NFSV3 | NFSMNT_WSIZE |
265 		    NFSMNT_RSIZE | NFSMNT_RESVPORT);
266 		if (inaddr_to_sockaddr("boot.nfsroot.server",
267 		    &nd3->root_saddr)) {
268 			printf("nfs_diskless: no server\n");
269 			return;
270 		}
271 		nd3->root_saddr.sin_port = htons(NFS_PORT);
272 		fhlen = decode_nfshandle("boot.nfsroot.nfshandle",
273 		    &nd3->root_fh[0], NFSX_V3FHMAX);
274 		if (fhlen == 0) {
275 			printf("nfs_diskless: no NFS handle\n");
276 			return;
277 		}
278 		if (fhlen != nd3->root_fhsize) {
279 			printf("nfs_diskless: bad NFS handle len=%d\n", fhlen);
280 			return;
281 		}
282 		if ((cp = kern_getenv("boot.nfsroot.path")) != NULL) {
283 			strncpy(nd3->root_hostnam, cp, MNAMELEN - 1);
284 			freeenv(cp);
285 		}
286 		if ((cp = kern_getenv("boot.nfsroot.options")) != NULL) {
287 			nfs_parse_options(cp, &nd3->root_args);
288 			freeenv(cp);
289 		}
290 
291 		nfs_diskless_valid = 3;
292 	} else {
293 		strlcpy(nd->myif.ifra_name, ifp->if_xname,
294 		    sizeof(nd->myif.ifra_name));
295 
296 		/* set up gateway */
297 		inaddr_to_sockaddr("boot.netif.gateway", &nd->mygateway);
298 
299 		/* set up root mount */
300 		nd->root_args.rsize = 8192;		/* XXX tunable? */
301 		nd->root_args.wsize = 8192;
302 		nd->root_args.sotype = SOCK_STREAM;
303 		nd->root_args.flags = (NFSMNT_WSIZE |
304 		    NFSMNT_RSIZE | NFSMNT_RESVPORT);
305 		if (inaddr_to_sockaddr("boot.nfsroot.server",
306 		    &nd->root_saddr)) {
307 			printf("nfs_diskless: no server\n");
308 			return;
309 		}
310 		nd->root_saddr.sin_port = htons(NFS_PORT);
311 		if (decode_nfshandle("boot.nfsroot.nfshandle",
312 		    &nd->root_fh[0], NFSX_V2FH) == 0) {
313 			printf("nfs_diskless: no NFS handle\n");
314 			return;
315 		}
316 		if ((cp = kern_getenv("boot.nfsroot.path")) != NULL) {
317 			strncpy(nd->root_hostnam, cp, MNAMELEN - 1);
318 			freeenv(cp);
319 		}
320 		if ((cp = kern_getenv("boot.nfsroot.options")) != NULL) {
321 			struct nfs_args args;
322 
323 			/*
324 			 * XXX yech, convert between old and current
325 			 * arg format
326 			 */
327 			args.flags = nd->root_args.flags;
328 			args.sotype = nd->root_args.sotype;
329 			args.rsize = nd->root_args.rsize;
330 			args.wsize = nd->root_args.wsize;
331 			nfs_parse_options(cp, &args);
332 			nd->root_args.flags = args.flags;
333 			nd->root_args.sotype = args.sotype;
334 			nd->root_args.rsize = args.rsize;
335 			nd->root_args.wsize = args.wsize;
336 			freeenv(cp);
337 		}
338 
339 		nfs_diskless_valid = 1;
340 	}
341 }
342 
343 static int
344 inaddr_to_sockaddr(char *ev, struct sockaddr_in *sa)
345 {
346 	u_int32_t a[4];
347 	char *cp;
348 	int count;
349 
350 	bzero(sa, sizeof(*sa));
351 	sa->sin_len = sizeof(*sa);
352 	sa->sin_family = AF_INET;
353 
354 	if ((cp = kern_getenv(ev)) == NULL)
355 		return (1);
356 	count = sscanf(cp, "%d.%d.%d.%d", &a[0], &a[1], &a[2], &a[3]);
357 	freeenv(cp);
358 	if (count != 4)
359 		return (1);
360 	sa->sin_addr.s_addr =
361 	    htonl((a[0] << 24) | (a[1] << 16) | (a[2] << 8) | a[3]);
362 	return (0);
363 }
364 
365 static int
366 hwaddr_to_sockaddr(char *ev, struct sockaddr_dl *sa)
367 {
368 	char *cp;
369 	u_int32_t a[6];
370 	int count;
371 
372 	bzero(sa, sizeof(*sa));
373 	sa->sdl_len = sizeof(*sa);
374 	sa->sdl_family = AF_LINK;
375 	sa->sdl_type = IFT_ETHER;
376 	sa->sdl_alen = ETHER_ADDR_LEN;
377 	if ((cp = kern_getenv(ev)) == NULL)
378 		return (1);
379 	count = sscanf(cp, "%x:%x:%x:%x:%x:%x",
380 	    &a[0], &a[1], &a[2], &a[3], &a[4], &a[5]);
381 	freeenv(cp);
382 	if (count != 6)
383 		return (1);
384 	sa->sdl_data[0] = a[0];
385 	sa->sdl_data[1] = a[1];
386 	sa->sdl_data[2] = a[2];
387 	sa->sdl_data[3] = a[3];
388 	sa->sdl_data[4] = a[4];
389 	sa->sdl_data[5] = a[5];
390 	return (0);
391 }
392 
393 static int
394 decode_nfshandle(char *ev, u_char *fh, int maxfh)
395 {
396 	u_char *cp, *ep;
397 	int len, val;
398 
399 	ep = cp = kern_getenv(ev);
400 	if (cp == NULL)
401 		return (0);
402 	if ((strlen(cp) < 2) || (*cp != 'X')) {
403 		freeenv(ep);
404 		return (0);
405 	}
406 	len = 0;
407 	cp++;
408 	for (;;) {
409 		if (*cp == 'X') {
410 			freeenv(ep);
411 			return (len);
412 		}
413 		if ((sscanf(cp, "%2x", &val) != 1) || (val > 0xff)) {
414 			freeenv(ep);
415 			return (0);
416 		}
417 		*(fh++) = val;
418 		len++;
419 		cp += 2;
420 		if (len > maxfh) {
421 		    freeenv(ep);
422 		    return (0);
423 		}
424 	}
425 }
426 
427 #if !defined(BOOTP_NFSROOT)
428 static void
429 nfs_rootconf(void)
430 {
431 
432 	nfs_setup_diskless();
433 	if (nfs_diskless_valid)
434 		rootdevnames[0] = "nfs:";
435 }
436 
437 SYSINIT(cpu_rootconf, SI_SUB_ROOT_CONF, SI_ORDER_FIRST, nfs_rootconf, NULL);
438 #endif
439 
440