xref: /freebsd/sys/nfs/nfs_diskless.c (revision 3416500aef140042c64bc149cb1ec6620483bc44)
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  * 3. 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 #define	NFS_IFACE_TIMEOUT_SECS	10 /* Timeout for interface to appear. */
61 
62 static int inaddr_to_sockaddr(char *ev, struct sockaddr_in *sa);
63 static int hwaddr_to_sockaddr(char *ev, struct sockaddr_dl *sa);
64 static int decode_nfshandle(char *ev, u_char *fh, int maxfh);
65 
66 /*
67  * This structure must be filled in by a primary bootstrap or bootstrap
68  * server for a diskless/dataless machine. It is initialized below just
69  * to ensure that it is allocated to initialized data (.data not .bss).
70  */
71 struct nfs_diskless	nfs_diskless = { { { 0 } } };
72 struct nfsv3_diskless	nfsv3_diskless = { { { 0 } } };
73 int			nfs_diskless_valid = 0;
74 
75 /*
76  * Validate/sanity check a rsize/wsize parameter.
77  */
78 static int
79 checkrwsize(unsigned long v, const char *name)
80 {
81 	/*
82 	 * 32K is used as an upper bound because most servers
83 	 * limit block size to satisfy IPv4's limit of
84 	 * 64K/reassembled packet.  The lower bound is pretty
85 	 * much arbitrary.
86 	 */
87 	if (!(4 <= v && v <= 32*1024)) {
88 		printf("nfs_parse_options: invalid %s %lu ignored\n", name, v);
89 		return 0;
90 	} else
91 		return 1;
92 }
93 
94 /*
95  * Parse mount options and apply them to the supplied
96  * nfs_diskless state.  Used also by bootp/dhcp support.
97  */
98 void
99 nfs_parse_options(const char *envopts, struct nfs_args *nd)
100 {
101 	char *opts, *o, *otmp;
102 	unsigned long v;
103 
104 	opts = strdup(envopts, M_TEMP);
105 	otmp = opts;
106 	while ((o = strsep(&otmp, ":;, ")) != NULL) {
107 		if (*o == '\0')
108 			; /* Skip empty options. */
109 		else if (strcmp(o, "soft") == 0)
110 			nd->flags |= NFSMNT_SOFT;
111 		else if (strcmp(o, "intr") == 0)
112 			nd->flags |= NFSMNT_INT;
113 		else if (strcmp(o, "conn") == 0)
114 			nd->flags |= NFSMNT_NOCONN;
115 		else if (strcmp(o, "nolockd") == 0)
116 			nd->flags |= NFSMNT_NOLOCKD;
117 		else if (strcmp(o, "nocto") == 0)
118 			nd->flags |= NFSMNT_NOCTO;
119 		else if (strcmp(o, "nfsv2") == 0)
120 			nd->flags &= ~(NFSMNT_NFSV3 | NFSMNT_NFSV4);
121 		else if (strcmp(o, "nfsv3") == 0) {
122 			nd->flags &= ~NFSMNT_NFSV4;
123 			nd->flags |= NFSMNT_NFSV3;
124 		} else if (strcmp(o, "tcp") == 0)
125 			nd->sotype = SOCK_STREAM;
126 		else if (strcmp(o, "udp") == 0)
127 			nd->sotype = SOCK_DGRAM;
128 		else if (strncmp(o, "rsize=", 6) == 0) {
129 			v = strtoul(o+6, NULL, 10);
130 			if (checkrwsize(v, "rsize")) {
131 				nd->rsize = (int) v;
132 				nd->flags |= NFSMNT_RSIZE;
133 			}
134 		} else if (strncmp(o, "wsize=", 6) == 0) {
135 			v = strtoul(o+6, NULL, 10);
136 			if (checkrwsize(v, "wsize")) {
137 				nd->wsize = (int) v;
138 				nd->flags |= NFSMNT_WSIZE;
139 			}
140 		} else
141 			printf("%s: skipping unknown option \"%s\"\n",
142 			    __func__, o);
143 	}
144 	free(opts, M_TEMP);
145 }
146 
147 /*
148  * Populate the essential fields in the nfsv3_diskless structure.
149  *
150  * The loader is expected to export the following environment variables:
151  *
152  * boot.netif.name		name of boot interface
153  * boot.netif.ip		IP address on boot interface
154  * boot.netif.netmask		netmask on boot interface
155  * boot.netif.gateway		default gateway (optional)
156  * boot.netif.hwaddr		hardware address of boot interface
157  * boot.netif.mtu		interface mtu from bootp/dhcp (optional)
158  * boot.nfsroot.server		IP address of root filesystem server
159  * boot.nfsroot.path		path of the root filesystem on server
160  * boot.nfsroot.nfshandle	NFS handle for root filesystem on server
161  * boot.nfsroot.nfshandlelen	and length of this handle (for NFSv3 only)
162  * boot.nfsroot.options		NFS options for the root filesystem
163  */
164 void
165 nfs_setup_diskless(void)
166 {
167 	struct nfs_diskless *nd = &nfs_diskless;
168 	struct nfsv3_diskless *nd3 = &nfsv3_diskless;
169 	struct ifnet *ifp;
170 	struct ifaddr *ifa;
171 	struct sockaddr_dl *sdl, ourdl;
172 	struct sockaddr_in myaddr, netmask;
173 	char *cp;
174 	int cnt, fhlen, is_nfsv3;
175 	uint32_t len;
176 	time_t timeout_at;
177 
178 	if (nfs_diskless_valid != 0)
179 		return;
180 
181 	/* get handle size. If this succeeds, it's an NFSv3 setup. */
182 	if ((cp = kern_getenv("boot.nfsroot.nfshandlelen")) != NULL) {
183 		cnt = sscanf(cp, "%d", &len);
184 		freeenv(cp);
185 		if (cnt != 1 || len == 0 || len > NFSX_V3FHMAX) {
186 			printf("nfs_diskless: bad NFS handle len\n");
187 			return;
188 		}
189 		nd3->root_fhsize = len;
190 		is_nfsv3 = 1;
191 	} else
192 		is_nfsv3 = 0;
193 	/* set up interface */
194 	if (inaddr_to_sockaddr("boot.netif.ip", &myaddr))
195 		return;
196 	if (inaddr_to_sockaddr("boot.netif.netmask", &netmask)) {
197 		printf("nfs_diskless: no netmask\n");
198 		return;
199 	}
200 	if (is_nfsv3 != 0) {
201 		bcopy(&myaddr, &nd3->myif.ifra_addr, sizeof(myaddr));
202 		bcopy(&myaddr, &nd3->myif.ifra_broadaddr, sizeof(myaddr));
203 		((struct sockaddr_in *)
204 		   &nd3->myif.ifra_broadaddr)->sin_addr.s_addr =
205 		    myaddr.sin_addr.s_addr | ~ netmask.sin_addr.s_addr;
206 		bcopy(&netmask, &nd3->myif.ifra_mask, sizeof(netmask));
207 	} else {
208 		bcopy(&myaddr, &nd->myif.ifra_addr, sizeof(myaddr));
209 		bcopy(&myaddr, &nd->myif.ifra_broadaddr, sizeof(myaddr));
210 		((struct sockaddr_in *)
211 		   &nd->myif.ifra_broadaddr)->sin_addr.s_addr =
212 		    myaddr.sin_addr.s_addr | ~ netmask.sin_addr.s_addr;
213 		bcopy(&netmask, &nd->myif.ifra_mask, sizeof(netmask));
214 	}
215 
216 	if (hwaddr_to_sockaddr("boot.netif.hwaddr", &ourdl)) {
217 		printf("nfs_diskless: no hardware address\n");
218 		return;
219 	}
220 	ifa = NULL;
221 	timeout_at = time_uptime + NFS_IFACE_TIMEOUT_SECS;
222 retry:
223 	CURVNET_SET(TD_TO_VNET(curthread));
224 	IFNET_RLOCK();
225 	TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
226 		TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
227 			if (ifa->ifa_addr->sa_family == AF_LINK) {
228 				sdl = (struct sockaddr_dl *)ifa->ifa_addr;
229 				if ((sdl->sdl_type == ourdl.sdl_type) &&
230 				    (sdl->sdl_alen == ourdl.sdl_alen) &&
231 				    !bcmp(LLADDR(sdl),
232 					  LLADDR(&ourdl),
233 					  sdl->sdl_alen)) {
234 				    IFNET_RUNLOCK();
235 				    CURVNET_RESTORE();
236 				    goto match_done;
237 				}
238 			}
239 		}
240 	}
241 	IFNET_RUNLOCK();
242 	CURVNET_RESTORE();
243 	if (time_uptime < timeout_at) {
244 		pause("nfssdl", hz / 5);
245 		goto retry;
246 	}
247 	printf("nfs_diskless: no interface\n");
248 	return;	/* no matching interface */
249 match_done:
250 	kern_setenv("boot.netif.name", ifp->if_xname);
251 	if (is_nfsv3 != 0) {
252 		strlcpy(nd3->myif.ifra_name, ifp->if_xname,
253 		    sizeof(nd3->myif.ifra_name));
254 
255 		/* set up gateway */
256 		inaddr_to_sockaddr("boot.netif.gateway", &nd3->mygateway);
257 
258 		/* set up root mount */
259 		nd3->root_args.rsize = 32768;		/* XXX tunable? */
260 		nd3->root_args.wsize = 32768;
261 		nd3->root_args.sotype = SOCK_STREAM;
262 		nd3->root_args.flags = (NFSMNT_NFSV3 | NFSMNT_WSIZE |
263 		    NFSMNT_RSIZE | NFSMNT_RESVPORT);
264 		if (inaddr_to_sockaddr("boot.nfsroot.server",
265 		    &nd3->root_saddr)) {
266 			printf("nfs_diskless: no server\n");
267 			return;
268 		}
269 		nd3->root_saddr.sin_port = htons(NFS_PORT);
270 		fhlen = decode_nfshandle("boot.nfsroot.nfshandle",
271 		    &nd3->root_fh[0], NFSX_V3FHMAX);
272 		if (fhlen == 0) {
273 			printf("nfs_diskless: no NFS handle\n");
274 			return;
275 		}
276 		if (fhlen != nd3->root_fhsize) {
277 			printf("nfs_diskless: bad NFS handle len=%d\n", fhlen);
278 			return;
279 		}
280 		if ((cp = kern_getenv("boot.nfsroot.path")) != NULL) {
281 			strncpy(nd3->root_hostnam, cp, MNAMELEN - 1);
282 			freeenv(cp);
283 		}
284 		if ((cp = kern_getenv("boot.nfsroot.options")) != NULL) {
285 			nfs_parse_options(cp, &nd3->root_args);
286 			freeenv(cp);
287 		}
288 
289 		nfs_diskless_valid = 3;
290 	} else {
291 		strlcpy(nd->myif.ifra_name, ifp->if_xname,
292 		    sizeof(nd->myif.ifra_name));
293 
294 		/* set up gateway */
295 		inaddr_to_sockaddr("boot.netif.gateway", &nd->mygateway);
296 
297 		/* set up root mount */
298 		nd->root_args.rsize = 8192;		/* XXX tunable? */
299 		nd->root_args.wsize = 8192;
300 		nd->root_args.sotype = SOCK_STREAM;
301 		nd->root_args.flags = (NFSMNT_WSIZE |
302 		    NFSMNT_RSIZE | NFSMNT_RESVPORT);
303 		if (inaddr_to_sockaddr("boot.nfsroot.server",
304 		    &nd->root_saddr)) {
305 			printf("nfs_diskless: no server\n");
306 			return;
307 		}
308 		nd->root_saddr.sin_port = htons(NFS_PORT);
309 		if (decode_nfshandle("boot.nfsroot.nfshandle",
310 		    &nd->root_fh[0], NFSX_V2FH) == 0) {
311 			printf("nfs_diskless: no NFS handle\n");
312 			return;
313 		}
314 		if ((cp = kern_getenv("boot.nfsroot.path")) != NULL) {
315 			strncpy(nd->root_hostnam, cp, MNAMELEN - 1);
316 			freeenv(cp);
317 		}
318 		if ((cp = kern_getenv("boot.nfsroot.options")) != NULL) {
319 			struct nfs_args args;
320 
321 			/*
322 			 * XXX yech, convert between old and current
323 			 * arg format
324 			 */
325 			args.flags = nd->root_args.flags;
326 			args.sotype = nd->root_args.sotype;
327 			args.rsize = nd->root_args.rsize;
328 			args.wsize = nd->root_args.wsize;
329 			nfs_parse_options(cp, &args);
330 			nd->root_args.flags = args.flags;
331 			nd->root_args.sotype = args.sotype;
332 			nd->root_args.rsize = args.rsize;
333 			nd->root_args.wsize = args.wsize;
334 			freeenv(cp);
335 		}
336 
337 		nfs_diskless_valid = 1;
338 	}
339 }
340 
341 static int
342 inaddr_to_sockaddr(char *ev, struct sockaddr_in *sa)
343 {
344 	u_int32_t a[4];
345 	char *cp;
346 	int count;
347 
348 	bzero(sa, sizeof(*sa));
349 	sa->sin_len = sizeof(*sa);
350 	sa->sin_family = AF_INET;
351 
352 	if ((cp = kern_getenv(ev)) == NULL)
353 		return (1);
354 	count = sscanf(cp, "%d.%d.%d.%d", &a[0], &a[1], &a[2], &a[3]);
355 	freeenv(cp);
356 	if (count != 4)
357 		return (1);
358 	sa->sin_addr.s_addr =
359 	    htonl((a[0] << 24) | (a[1] << 16) | (a[2] << 8) | a[3]);
360 	return (0);
361 }
362 
363 static int
364 hwaddr_to_sockaddr(char *ev, struct sockaddr_dl *sa)
365 {
366 	char *cp;
367 	u_int32_t a[6];
368 	int count;
369 
370 	bzero(sa, sizeof(*sa));
371 	sa->sdl_len = sizeof(*sa);
372 	sa->sdl_family = AF_LINK;
373 	sa->sdl_type = IFT_ETHER;
374 	sa->sdl_alen = ETHER_ADDR_LEN;
375 	if ((cp = kern_getenv(ev)) == NULL)
376 		return (1);
377 	count = sscanf(cp, "%x:%x:%x:%x:%x:%x",
378 	    &a[0], &a[1], &a[2], &a[3], &a[4], &a[5]);
379 	freeenv(cp);
380 	if (count != 6)
381 		return (1);
382 	sa->sdl_data[0] = a[0];
383 	sa->sdl_data[1] = a[1];
384 	sa->sdl_data[2] = a[2];
385 	sa->sdl_data[3] = a[3];
386 	sa->sdl_data[4] = a[4];
387 	sa->sdl_data[5] = a[5];
388 	return (0);
389 }
390 
391 static int
392 decode_nfshandle(char *ev, u_char *fh, int maxfh)
393 {
394 	u_char *cp, *ep;
395 	int len, val;
396 
397 	ep = cp = kern_getenv(ev);
398 	if (cp == NULL)
399 		return (0);
400 	if ((strlen(cp) < 2) || (*cp != 'X')) {
401 		freeenv(ep);
402 		return (0);
403 	}
404 	len = 0;
405 	cp++;
406 	for (;;) {
407 		if (*cp == 'X') {
408 			freeenv(ep);
409 			return (len);
410 		}
411 		if ((sscanf(cp, "%2x", &val) != 1) || (val > 0xff)) {
412 			freeenv(ep);
413 			return (0);
414 		}
415 		*(fh++) = val;
416 		len++;
417 		cp += 2;
418 		if (len > maxfh) {
419 		    freeenv(ep);
420 		    return (0);
421 		}
422 	}
423 }
424 
425 #if !defined(BOOTP_NFSROOT)
426 static void
427 nfs_rootconf(void)
428 {
429 
430 	nfs_setup_diskless();
431 	if (nfs_diskless_valid)
432 		rootdevnames[0] = "nfs:";
433 }
434 
435 SYSINIT(cpu_rootconf, SI_SUB_ROOT_CONF, SI_ORDER_FIRST, nfs_rootconf, NULL);
436 #endif
437 
438