xref: /freebsd/sys/nfs/nfs_diskless.c (revision 48855ec75316aaec5538ef22132f96fd04e137d4)
1 /*-
2  * Copyright (c) 1990 The Regents of the University of California.
3  * All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * William Jolitz.
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  * 4. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  *
32  *	from: @(#)autoconf.c	7.1 (Berkeley) 5/9/91
33  */
34 
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
37 
38 #include "opt_bootp.h"
39 
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/jail.h>
43 #include <sys/kernel.h>
44 #include <sys/malloc.h>
45 #include <sys/mount.h>
46 #include <sys/socket.h>
47 
48 #include <net/if.h>
49 #include <net/if_dl.h>
50 #include <net/if_types.h>
51 #include <net/if_var.h>
52 #include <net/ethernet.h>
53 #include <net/vnet.h>
54 
55 #include <netinet/in.h>
56 #include <nfs/nfsproto.h>
57 #include <nfsclient/nfs.h>
58 #include <nfs/nfsdiskless.h>
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, "nfsv2") == 0)
116 			nd->flags &= ~(NFSMNT_NFSV3 | NFSMNT_NFSV4);
117 		else if (strcmp(o, "nfsv3") == 0) {
118 			nd->flags &= ~NFSMNT_NFSV4;
119 			nd->flags |= NFSMNT_NFSV3;
120 		} else if (strcmp(o, "tcp") == 0)
121 			nd->sotype = SOCK_STREAM;
122 		else if (strcmp(o, "udp") == 0)
123 			nd->sotype = SOCK_DGRAM;
124 		else if (strncmp(o, "rsize=", 6) == 0) {
125 			v = strtoul(o+6, NULL, 10);
126 			if (checkrwsize(v, "rsize")) {
127 				nd->rsize = (int) v;
128 				nd->flags |= NFSMNT_RSIZE;
129 			}
130 		} else if (strncmp(o, "wsize=", 6) == 0) {
131 			v = strtoul(o+6, NULL, 10);
132 			if (checkrwsize(v, "wsize")) {
133 				nd->wsize = (int) v;
134 				nd->flags |= NFSMNT_WSIZE;
135 			}
136 		} else
137 			printf("%s: skipping unknown option \"%s\"\n",
138 			    __func__, o);
139 	}
140 	free(opts, M_TEMP);
141 }
142 
143 /*
144  * Populate the essential fields in the nfsv3_diskless structure.
145  *
146  * The loader is expected to export the following environment variables:
147  *
148  * boot.netif.name		name of boot interface
149  * boot.netif.ip		IP address on boot interface
150  * boot.netif.netmask		netmask on boot interface
151  * boot.netif.gateway		default gateway (optional)
152  * boot.netif.hwaddr		hardware address of boot interface
153  * boot.nfsroot.server		IP address of root filesystem server
154  * boot.nfsroot.path		path of the root filesystem on server
155  * boot.nfsroot.nfshandle	NFS handle for root filesystem on server
156  * boot.nfsroot.nfshandlelen	and length of this handle (for NFSv3 only)
157  * boot.nfsroot.options		NFS options for the root filesystem
158  */
159 void
160 nfs_setup_diskless(void)
161 {
162 	struct nfs_diskless *nd = &nfs_diskless;
163 	struct nfsv3_diskless *nd3 = &nfsv3_diskless;
164 	struct ifnet *ifp;
165 	struct ifaddr *ifa;
166 	struct sockaddr_dl *sdl, ourdl;
167 	struct sockaddr_in myaddr, netmask;
168 	char *cp;
169 	int cnt, fhlen, is_nfsv3;
170 	uint32_t len;
171 
172 	if (nfs_diskless_valid != 0)
173 		return;
174 
175 	/* get handle size. If this succeeds, it's an NFSv3 setup. */
176 	if ((cp = getenv("boot.nfsroot.nfshandlelen")) != NULL) {
177 		cnt = sscanf(cp, "%d", &len);
178 		freeenv(cp);
179 		if (cnt != 1 || len == 0 || len > NFSX_V3FHMAX) {
180 			printf("nfs_diskless: bad NFS handle len\n");
181 			return;
182 		}
183 		nd3->root_fhsize = len;
184 		is_nfsv3 = 1;
185 	} else
186 		is_nfsv3 = 0;
187 	/* set up interface */
188 	if (inaddr_to_sockaddr("boot.netif.ip", &myaddr))
189 		return;
190 	if (inaddr_to_sockaddr("boot.netif.netmask", &netmask)) {
191 		printf("nfs_diskless: no netmask\n");
192 		return;
193 	}
194 	if (is_nfsv3 != 0) {
195 		bcopy(&myaddr, &nd3->myif.ifra_addr, sizeof(myaddr));
196 		bcopy(&myaddr, &nd3->myif.ifra_broadaddr, sizeof(myaddr));
197 		((struct sockaddr_in *)
198 		   &nd3->myif.ifra_broadaddr)->sin_addr.s_addr =
199 		    myaddr.sin_addr.s_addr | ~ netmask.sin_addr.s_addr;
200 		bcopy(&netmask, &nd3->myif.ifra_mask, sizeof(netmask));
201 	} else {
202 		bcopy(&myaddr, &nd->myif.ifra_addr, sizeof(myaddr));
203 		bcopy(&myaddr, &nd->myif.ifra_broadaddr, sizeof(myaddr));
204 		((struct sockaddr_in *)
205 		   &nd->myif.ifra_broadaddr)->sin_addr.s_addr =
206 		    myaddr.sin_addr.s_addr | ~ netmask.sin_addr.s_addr;
207 		bcopy(&netmask, &nd->myif.ifra_mask, sizeof(netmask));
208 	}
209 
210 	if (hwaddr_to_sockaddr("boot.netif.hwaddr", &ourdl)) {
211 		printf("nfs_diskless: no hardware address\n");
212 		return;
213 	}
214 	ifa = NULL;
215 	CURVNET_SET(TD_TO_VNET(curthread));
216 	IFNET_RLOCK();
217 	TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
218 		TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
219 			if (ifa->ifa_addr->sa_family == AF_LINK) {
220 				sdl = (struct sockaddr_dl *)ifa->ifa_addr;
221 				if ((sdl->sdl_type == ourdl.sdl_type) &&
222 				    (sdl->sdl_alen == ourdl.sdl_alen) &&
223 				    !bcmp(LLADDR(sdl),
224 					  LLADDR(&ourdl),
225 					  sdl->sdl_alen)) {
226 				    IFNET_RUNLOCK();
227 				    CURVNET_RESTORE();
228 				    goto match_done;
229 				}
230 			}
231 		}
232 	}
233 	IFNET_RUNLOCK();
234 	CURVNET_RESTORE();
235 	printf("nfs_diskless: no interface\n");
236 	return;	/* no matching interface */
237 match_done:
238 	setenv("boot.netif.name", ifp->if_xname);
239 	if (is_nfsv3 != 0) {
240 		strlcpy(nd3->myif.ifra_name, ifp->if_xname,
241 		    sizeof(nd3->myif.ifra_name));
242 
243 		/* set up gateway */
244 		inaddr_to_sockaddr("boot.netif.gateway", &nd3->mygateway);
245 
246 		/* set up root mount */
247 		nd3->root_args.rsize = 32768;		/* XXX tunable? */
248 		nd3->root_args.wsize = 32768;
249 		nd3->root_args.sotype = SOCK_STREAM;
250 		nd3->root_args.flags = (NFSMNT_NFSV3 | NFSMNT_WSIZE |
251 		    NFSMNT_RSIZE | NFSMNT_RESVPORT);
252 		if (inaddr_to_sockaddr("boot.nfsroot.server",
253 		    &nd3->root_saddr)) {
254 			printf("nfs_diskless: no server\n");
255 			return;
256 		}
257 		nd3->root_saddr.sin_port = htons(NFS_PORT);
258 		fhlen = decode_nfshandle("boot.nfsroot.nfshandle",
259 		    &nd3->root_fh[0], NFSX_V3FHMAX);
260 		if (fhlen == 0) {
261 			printf("nfs_diskless: no NFS handle\n");
262 			return;
263 		}
264 		if (fhlen != nd3->root_fhsize) {
265 			printf("nfs_diskless: bad NFS handle len=%d\n", fhlen);
266 			return;
267 		}
268 		if ((cp = getenv("boot.nfsroot.path")) != NULL) {
269 			strncpy(nd3->root_hostnam, cp, MNAMELEN - 1);
270 			freeenv(cp);
271 		}
272 		if ((cp = getenv("boot.nfsroot.options")) != NULL) {
273 			nfs_parse_options(cp, &nd3->root_args);
274 			freeenv(cp);
275 		}
276 
277 		nfs_diskless_valid = 3;
278 	} else {
279 		strlcpy(nd->myif.ifra_name, ifp->if_xname,
280 		    sizeof(nd->myif.ifra_name));
281 
282 		/* set up gateway */
283 		inaddr_to_sockaddr("boot.netif.gateway", &nd->mygateway);
284 
285 		/* set up root mount */
286 		nd->root_args.rsize = 8192;		/* XXX tunable? */
287 		nd->root_args.wsize = 8192;
288 		nd->root_args.sotype = SOCK_STREAM;
289 		nd->root_args.flags = (NFSMNT_WSIZE |
290 		    NFSMNT_RSIZE | NFSMNT_RESVPORT);
291 		if (inaddr_to_sockaddr("boot.nfsroot.server",
292 		    &nd->root_saddr)) {
293 			printf("nfs_diskless: no server\n");
294 			return;
295 		}
296 		nd->root_saddr.sin_port = htons(NFS_PORT);
297 		if (decode_nfshandle("boot.nfsroot.nfshandle",
298 		    &nd->root_fh[0], NFSX_V2FH) == 0) {
299 			printf("nfs_diskless: no NFS handle\n");
300 			return;
301 		}
302 		if ((cp = getenv("boot.nfsroot.path")) != NULL) {
303 			strncpy(nd->root_hostnam, cp, MNAMELEN - 1);
304 			freeenv(cp);
305 		}
306 		if ((cp = getenv("boot.nfsroot.options")) != NULL) {
307 			struct nfs_args args;
308 
309 			/*
310 			 * XXX yech, convert between old and current
311 			 * arg format
312 			 */
313 			args.flags = nd->root_args.flags;
314 			args.sotype = nd->root_args.sotype;
315 			args.rsize = nd->root_args.rsize;
316 			args.wsize = nd->root_args.wsize;
317 			nfs_parse_options(cp, &args);
318 			nd->root_args.flags = args.flags;
319 			nd->root_args.sotype = args.sotype;
320 			nd->root_args.rsize = args.rsize;
321 			nd->root_args.wsize = args.wsize;
322 			freeenv(cp);
323 		}
324 
325 		nfs_diskless_valid = 1;
326 	}
327 }
328 
329 static int
330 inaddr_to_sockaddr(char *ev, struct sockaddr_in *sa)
331 {
332 	u_int32_t a[4];
333 	char *cp;
334 	int count;
335 
336 	bzero(sa, sizeof(*sa));
337 	sa->sin_len = sizeof(*sa);
338 	sa->sin_family = AF_INET;
339 
340 	if ((cp = getenv(ev)) == NULL)
341 		return (1);
342 	count = sscanf(cp, "%d.%d.%d.%d", &a[0], &a[1], &a[2], &a[3]);
343 	freeenv(cp);
344 	if (count != 4)
345 		return (1);
346 	sa->sin_addr.s_addr =
347 	    htonl((a[0] << 24) | (a[1] << 16) | (a[2] << 8) | a[3]);
348 	return (0);
349 }
350 
351 static int
352 hwaddr_to_sockaddr(char *ev, struct sockaddr_dl *sa)
353 {
354 	char *cp;
355 	u_int32_t a[6];
356 	int count;
357 
358 	bzero(sa, sizeof(*sa));
359 	sa->sdl_len = sizeof(*sa);
360 	sa->sdl_family = AF_LINK;
361 	sa->sdl_type = IFT_ETHER;
362 	sa->sdl_alen = ETHER_ADDR_LEN;
363 	if ((cp = getenv(ev)) == NULL)
364 		return (1);
365 	count = sscanf(cp, "%x:%x:%x:%x:%x:%x",
366 	    &a[0], &a[1], &a[2], &a[3], &a[4], &a[5]);
367 	freeenv(cp);
368 	if (count != 6)
369 		return (1);
370 	sa->sdl_data[0] = a[0];
371 	sa->sdl_data[1] = a[1];
372 	sa->sdl_data[2] = a[2];
373 	sa->sdl_data[3] = a[3];
374 	sa->sdl_data[4] = a[4];
375 	sa->sdl_data[5] = a[5];
376 	return (0);
377 }
378 
379 static int
380 decode_nfshandle(char *ev, u_char *fh, int maxfh)
381 {
382 	u_char *cp, *ep;
383 	int len, val;
384 
385 	ep = cp = getenv(ev);
386 	if (cp == NULL)
387 		return (0);
388 	if ((strlen(cp) < 2) || (*cp != 'X')) {
389 		freeenv(ep);
390 		return (0);
391 	}
392 	len = 0;
393 	cp++;
394 	for (;;) {
395 		if (*cp == 'X') {
396 			freeenv(ep);
397 			return (len);
398 		}
399 		if ((sscanf(cp, "%2x", &val) != 1) || (val > 0xff)) {
400 			freeenv(ep);
401 			return (0);
402 		}
403 		*(fh++) = val;
404 		len++;
405 		cp += 2;
406 		if (len > maxfh) {
407 		    freeenv(ep);
408 		    return (0);
409 		}
410 	}
411 }
412 
413 #if !defined(BOOTP_NFSROOT)
414 static void
415 nfs_rootconf(void)
416 {
417 
418 	nfs_setup_diskless();
419 	if (nfs_diskless_valid)
420 		rootdevnames[0] = "nfs:";
421 }
422 
423 SYSINIT(cpu_rootconf, SI_SUB_ROOT_CONF, SI_ORDER_FIRST, nfs_rootconf, NULL);
424 #endif
425 
426