xref: /freebsd/sys/nfs/nfs_diskless.c (revision 4543ef516683042d46f3bd3bb8a4f3f746e00499)
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 
35 #include <sys/cdefs.h>
36 #include "opt_bootp.h"
37 
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/jail.h>
41 #include <sys/kernel.h>
42 #include <sys/malloc.h>
43 #include <sys/mount.h>
44 #include <sys/socket.h>
45 
46 #include <net/if.h>
47 #include <net/if_dl.h>
48 #include <net/if_types.h>
49 #include <net/if_var.h>
50 #include <net/ethernet.h>
51 #include <net/vnet.h>
52 
53 #include <netinet/in.h>
54 #include <nfs/nfsproto.h>
55 #include <nfsclient/nfs.h>
56 #include <nfs/nfsdiskless.h>
57 
58 #define	NFS_IFACE_TIMEOUT_SECS	10 /* Timeout for interface to appear. */
59 
60 static int inaddr_to_sockaddr(char *ev, struct sockaddr_in *sa);
61 static int hwaddr_to_sockaddr(char *ev, struct sockaddr_dl *sa);
62 static int decode_nfshandle(char *ev, u_char *fh, int maxfh);
63 
64 /*
65  * This structure must be filled in by a primary bootstrap or bootstrap
66  * server for a diskless/dataless machine. It is initialized below just
67  * to ensure that it is allocated to initialized data (.data not .bss).
68  */
69 struct nfs_diskless	nfs_diskless = { { { 0 } } };
70 struct nfsv3_diskless	nfsv3_diskless = { { { 0 } } };
71 int			nfs_diskless_valid = 0;
72 
73 /*
74  * Validate/sanity check a rsize/wsize parameter.
75  */
76 static int
77 checkrwsize(unsigned long v, const char *name)
78 {
79 	/*
80 	 * 32K is used as an upper bound because most servers
81 	 * limit block size to satisfy IPv4's limit of
82 	 * 64K/reassembled packet.  The lower bound is pretty
83 	 * much arbitrary.
84 	 */
85 	if (!(4 <= v && v <= 32*1024)) {
86 		printf("nfs_parse_options: invalid %s %lu ignored\n", name, v);
87 		return 0;
88 	} else
89 		return 1;
90 }
91 
92 /*
93  * Parse mount options and apply them to the supplied
94  * nfs_diskless state.  Used also by bootp/dhcp support.
95  */
96 void
97 nfs_parse_options(const char *envopts, struct nfs_args *nd)
98 {
99 	char *opts, *o, *otmp;
100 	unsigned long v;
101 
102 	opts = strdup(envopts, M_TEMP);
103 	otmp = opts;
104 	while ((o = strsep(&otmp, ":;, ")) != NULL) {
105 		if (*o == '\0')
106 			; /* Skip empty options. */
107 		else if (strcmp(o, "soft") == 0)
108 			nd->flags |= NFSMNT_SOFT;
109 		else if (strcmp(o, "intr") == 0)
110 			nd->flags |= NFSMNT_INT;
111 		else if (strcmp(o, "conn") == 0)
112 			nd->flags |= NFSMNT_NOCONN;
113 		else if (strcmp(o, "nolockd") == 0)
114 			nd->flags |= NFSMNT_NOLOCKD;
115 		else if (strcmp(o, "nocto") == 0)
116 			nd->flags |= NFSMNT_NOCTO;
117 		else if (strcmp(o, "nfsv2") == 0)
118 			nd->flags &= ~(NFSMNT_NFSV3 | NFSMNT_NFSV4);
119 		else if (strcmp(o, "nfsv3") == 0) {
120 			nd->flags &= ~NFSMNT_NFSV4;
121 			nd->flags |= NFSMNT_NFSV3;
122 		} else if (strcmp(o, "tcp") == 0)
123 			nd->sotype = SOCK_STREAM;
124 		else if (strcmp(o, "udp") == 0)
125 			nd->sotype = SOCK_DGRAM;
126 		else if (strncmp(o, "rsize=", 6) == 0) {
127 			v = strtoul(o+6, NULL, 10);
128 			if (checkrwsize(v, "rsize")) {
129 				nd->rsize = (int) v;
130 				nd->flags |= NFSMNT_RSIZE;
131 			}
132 		} else if (strncmp(o, "wsize=", 6) == 0) {
133 			v = strtoul(o+6, NULL, 10);
134 			if (checkrwsize(v, "wsize")) {
135 				nd->wsize = (int) v;
136 				nd->flags |= NFSMNT_WSIZE;
137 			}
138 		} else
139 			printf("%s: skipping unknown option \"%s\"\n",
140 			    __func__, o);
141 	}
142 	free(opts, M_TEMP);
143 }
144 
145 static u_int
146 nfs_setup_diskless_ifa_cb(void *arg, struct sockaddr_dl *sdl, u_int count)
147 {
148 	struct sockaddr_dl *ourdl = arg;
149 
150 	if ((sdl->sdl_type == ourdl->sdl_type) &&
151 	    (sdl->sdl_alen == ourdl->sdl_alen) &&
152 	    !bcmp(LLADDR(sdl), LLADDR(ourdl), sdl->sdl_alen))
153 		return (1);
154 
155 	return (0);
156 }
157 
158 /*
159  * Populate the essential fields in the nfsv3_diskless structure.
160  *
161  * The loader is expected to export the following environment variables:
162  *
163  * boot.netif.name		name of boot interface
164  * boot.netif.ip		IP address on boot interface
165  * boot.netif.netmask		netmask on boot interface
166  * boot.netif.gateway		default gateway (optional)
167  * boot.netif.hwaddr		hardware address of boot interface
168  * boot.netif.mtu		interface mtu from bootp/dhcp (optional)
169  * boot.nfsroot.server		IP address of root filesystem server
170  * boot.nfsroot.path		path of the root filesystem on server
171  * boot.nfsroot.nfshandle	NFS handle for root filesystem on server
172  * boot.nfsroot.nfshandlelen	and length of this handle (for NFSv3 only)
173  * boot.nfsroot.options		NFS options for the root filesystem
174  */
175 void
176 nfs_setup_diskless(void)
177 {
178 	struct epoch_tracker et;
179 	struct if_iter iter;
180 	struct nfs_diskless *nd = &nfs_diskless;
181 	struct nfsv3_diskless *nd3 = &nfsv3_diskless;
182 	if_t ifp;
183 	struct sockaddr_dl ourdl;
184 	struct sockaddr_in myaddr, netmask;
185 	char *cp;
186 	int cnt, fhlen, is_nfsv3;
187 	uint32_t len;
188 	time_t timeout_at;
189 
190 	if (nfs_diskless_valid != 0)
191 		return;
192 
193 	/* get handle size. If this succeeds, it's an NFSv3 setup. */
194 	if ((cp = kern_getenv("boot.nfsroot.nfshandlelen")) != NULL) {
195 		cnt = sscanf(cp, "%d", &len);
196 		freeenv(cp);
197 		if (cnt != 1 || len == 0 || len > NFSX_V3FHMAX) {
198 			printf("nfs_diskless: bad NFS handle len\n");
199 			return;
200 		}
201 		nd3->root_fhsize = len;
202 		is_nfsv3 = 1;
203 	} else
204 		is_nfsv3 = 0;
205 	/* set up interface */
206 	if (inaddr_to_sockaddr("boot.netif.ip", &myaddr))
207 		return;
208 	if (inaddr_to_sockaddr("boot.netif.netmask", &netmask)) {
209 		printf("nfs_diskless: no netmask\n");
210 		return;
211 	}
212 	if (is_nfsv3 != 0) {
213 		bcopy(&myaddr, &nd3->myif.ifra_addr, sizeof(myaddr));
214 		bcopy(&myaddr, &nd3->myif.ifra_broadaddr, sizeof(myaddr));
215 		((struct sockaddr_in *)
216 		   &nd3->myif.ifra_broadaddr)->sin_addr.s_addr =
217 		    myaddr.sin_addr.s_addr | ~ netmask.sin_addr.s_addr;
218 		bcopy(&netmask, &nd3->myif.ifra_mask, sizeof(netmask));
219 	} else {
220 		bcopy(&myaddr, &nd->myif.ifra_addr, sizeof(myaddr));
221 		bcopy(&myaddr, &nd->myif.ifra_broadaddr, sizeof(myaddr));
222 		((struct sockaddr_in *)
223 		   &nd->myif.ifra_broadaddr)->sin_addr.s_addr =
224 		    myaddr.sin_addr.s_addr | ~ netmask.sin_addr.s_addr;
225 		bcopy(&netmask, &nd->myif.ifra_mask, sizeof(netmask));
226 	}
227 
228 	if (hwaddr_to_sockaddr("boot.netif.hwaddr", &ourdl)) {
229 		printf("nfs_diskless: no hardware address\n");
230 		return;
231 	}
232 	timeout_at = time_uptime + NFS_IFACE_TIMEOUT_SECS;
233 retry:
234 	CURVNET_SET(TD_TO_VNET(curthread));
235 	NET_EPOCH_ENTER(et);
236 	for (ifp = if_iter_start(&iter); ifp != NULL; ifp = if_iter_next(&iter)) {
237 		cnt = if_foreach_lladdr(ifp, nfs_setup_diskless_ifa_cb, &ourdl);
238 		if (cnt > 0)
239 			break;
240 	}
241 	if_iter_finish(&iter);
242 	NET_EPOCH_EXIT(et);
243 	CURVNET_RESTORE();
244 	if (ifp != NULL)
245 		goto match_done;
246 
247 	if (time_uptime < timeout_at) {
248 		pause("nfssdl", hz / 5);
249 		goto retry;
250 	}
251 	printf("nfs_diskless: no interface\n");
252 	return;	/* no matching interface */
253 match_done:
254 	kern_setenv("boot.netif.name", if_name(ifp));
255 	if (is_nfsv3 != 0) {
256 		strlcpy(nd3->myif.ifra_name, if_name(ifp),
257 		    sizeof(nd3->myif.ifra_name));
258 
259 		/* set up gateway */
260 		inaddr_to_sockaddr("boot.netif.gateway", &nd3->mygateway);
261 
262 		/* set up root mount */
263 		nd3->root_args.rsize = 32768;		/* XXX tunable? */
264 		nd3->root_args.wsize = 32768;
265 		nd3->root_args.sotype = SOCK_STREAM;
266 		nd3->root_args.flags = (NFSMNT_NFSV3 | NFSMNT_WSIZE |
267 		    NFSMNT_RSIZE | NFSMNT_RESVPORT);
268 		if (inaddr_to_sockaddr("boot.nfsroot.server",
269 		    &nd3->root_saddr)) {
270 			printf("nfs_diskless: no server\n");
271 			return;
272 		}
273 		nd3->root_saddr.sin_port = htons(NFS_PORT);
274 		fhlen = decode_nfshandle("boot.nfsroot.nfshandle",
275 		    &nd3->root_fh[0], NFSX_V3FHMAX);
276 		if (fhlen == 0) {
277 			printf("nfs_diskless: no NFS handle\n");
278 			return;
279 		}
280 		if (fhlen != nd3->root_fhsize) {
281 			printf("nfs_diskless: bad NFS handle len=%d\n", fhlen);
282 			return;
283 		}
284 		if ((cp = kern_getenv("boot.nfsroot.path")) != NULL) {
285 			strncpy(nd3->root_hostnam, cp, MNAMELEN - 1);
286 			freeenv(cp);
287 		}
288 		if ((cp = kern_getenv("boot.nfsroot.options")) != NULL) {
289 			nfs_parse_options(cp, &nd3->root_args);
290 			freeenv(cp);
291 		}
292 
293 		nfs_diskless_valid = 3;
294 	} else {
295 		strlcpy(nd->myif.ifra_name, if_name(ifp),
296 		    sizeof(nd->myif.ifra_name));
297 
298 		/* set up gateway */
299 		inaddr_to_sockaddr("boot.netif.gateway", &nd->mygateway);
300 
301 		/* set up root mount */
302 		nd->root_args.rsize = 8192;		/* XXX tunable? */
303 		nd->root_args.wsize = 8192;
304 		nd->root_args.sotype = SOCK_STREAM;
305 		nd->root_args.flags = (NFSMNT_WSIZE |
306 		    NFSMNT_RSIZE | NFSMNT_RESVPORT);
307 		if (inaddr_to_sockaddr("boot.nfsroot.server",
308 		    &nd->root_saddr)) {
309 			printf("nfs_diskless: no server\n");
310 			return;
311 		}
312 		nd->root_saddr.sin_port = htons(NFS_PORT);
313 		if (decode_nfshandle("boot.nfsroot.nfshandle",
314 		    &nd->root_fh[0], NFSX_V2FH) == 0) {
315 			printf("nfs_diskless: no NFS handle\n");
316 			return;
317 		}
318 		if ((cp = kern_getenv("boot.nfsroot.path")) != NULL) {
319 			strncpy(nd->root_hostnam, cp, MNAMELEN - 1);
320 			freeenv(cp);
321 		}
322 		if ((cp = kern_getenv("boot.nfsroot.options")) != NULL) {
323 			struct nfs_args args;
324 
325 			/*
326 			 * XXX yech, convert between old and current
327 			 * arg format
328 			 */
329 			args.flags = nd->root_args.flags;
330 			args.sotype = nd->root_args.sotype;
331 			args.rsize = nd->root_args.rsize;
332 			args.wsize = nd->root_args.wsize;
333 			nfs_parse_options(cp, &args);
334 			nd->root_args.flags = args.flags;
335 			nd->root_args.sotype = args.sotype;
336 			nd->root_args.rsize = args.rsize;
337 			nd->root_args.wsize = args.wsize;
338 			freeenv(cp);
339 		}
340 
341 		nfs_diskless_valid = 1;
342 	}
343 }
344 
345 static int
346 inaddr_to_sockaddr(char *ev, struct sockaddr_in *sa)
347 {
348 	u_int32_t a[4];
349 	char *cp;
350 	int count;
351 
352 	bzero(sa, sizeof(*sa));
353 	sa->sin_len = sizeof(*sa);
354 	sa->sin_family = AF_INET;
355 
356 	if ((cp = kern_getenv(ev)) == NULL)
357 		return (1);
358 	count = sscanf(cp, "%d.%d.%d.%d", &a[0], &a[1], &a[2], &a[3]);
359 	freeenv(cp);
360 	if (count != 4)
361 		return (1);
362 	sa->sin_addr.s_addr =
363 	    htonl((a[0] << 24) | (a[1] << 16) | (a[2] << 8) | a[3]);
364 	return (0);
365 }
366 
367 static int
368 hwaddr_to_sockaddr(char *ev, struct sockaddr_dl *sa)
369 {
370 	char *cp;
371 	u_int32_t a[6];
372 	int count;
373 
374 	bzero(sa, sizeof(*sa));
375 	sa->sdl_len = sizeof(*sa);
376 	sa->sdl_family = AF_LINK;
377 	sa->sdl_type = IFT_ETHER;
378 	sa->sdl_alen = ETHER_ADDR_LEN;
379 	if ((cp = kern_getenv(ev)) == NULL)
380 		return (1);
381 	count = sscanf(cp, "%x:%x:%x:%x:%x:%x",
382 	    &a[0], &a[1], &a[2], &a[3], &a[4], &a[5]);
383 	freeenv(cp);
384 	if (count != 6)
385 		return (1);
386 	sa->sdl_data[0] = a[0];
387 	sa->sdl_data[1] = a[1];
388 	sa->sdl_data[2] = a[2];
389 	sa->sdl_data[3] = a[3];
390 	sa->sdl_data[4] = a[4];
391 	sa->sdl_data[5] = a[5];
392 	return (0);
393 }
394 
395 static int
396 decode_nfshandle(char *ev, u_char *fh, int maxfh)
397 {
398 	u_char *cp, *ep;
399 	int len, val;
400 
401 	ep = cp = kern_getenv(ev);
402 	if (cp == NULL)
403 		return (0);
404 	if ((strlen(cp) < 2) || (*cp != 'X')) {
405 		freeenv(ep);
406 		return (0);
407 	}
408 	len = 0;
409 	cp++;
410 	for (;;) {
411 		if (*cp == 'X') {
412 			freeenv(ep);
413 			return (len);
414 		}
415 		if ((sscanf(cp, "%2x", &val) != 1) || (val > 0xff)) {
416 			freeenv(ep);
417 			return (0);
418 		}
419 		*(fh++) = val;
420 		len++;
421 		cp += 2;
422 		if (len > maxfh) {
423 		    freeenv(ep);
424 		    return (0);
425 		}
426 	}
427 }
428 
429 #if !defined(BOOTP_NFSROOT)
430 static void
431 nfs_rootconf(void)
432 {
433 
434 	nfs_setup_diskless();
435 	if (nfs_diskless_valid)
436 		rootdevnames[0] = "nfs:";
437 }
438 
439 SYSINIT(cpu_rootconf, SI_SUB_ROOT_CONF, SI_ORDER_FIRST, nfs_rootconf, NULL);
440 #endif
441