xref: /netbsd-src/sys/nfs/nfs_bootparam.c (revision deb6f0161a9109e7de9b519dc8dfb9478668dcdd)
1 /*	$NetBSD: nfs_bootparam.c,v 1.38 2013/09/12 18:00:18 drochner 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, Sun-style (RPC/bootparams)
34  */
35 
36 #include <sys/cdefs.h>
37 __KERNEL_RCSID(0, "$NetBSD: nfs_bootparam.c,v 1.38 2013/09/12 18:00:18 drochner Exp $");
38 
39 #ifdef _KERNEL_OPT
40 #include "opt_nfs_boot.h"
41 #include "arp.h"
42 #endif
43 
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/kernel.h>
47 #include <sys/ioctl.h>
48 #include <sys/proc.h>
49 #include <sys/mount.h>
50 #include <sys/mbuf.h>
51 #include <sys/reboot.h>
52 #include <sys/socket.h>
53 #include <sys/socketvar.h>
54 #include <sys/vnode.h>
55 
56 #include <net/if.h>
57 #include <net/if_types.h>
58 #include <net/route.h>
59 #include <net/if_ether.h>
60 
61 #include <netinet/in.h>
62 #include <netinet/if_inarp.h>
63 
64 #include <nfs/rpcv2.h>
65 #include <nfs/krpc.h>
66 #include <nfs/xdr_subs.h>
67 
68 #include <nfs/nfsproto.h>
69 #include <nfs/nfs.h>
70 #include <nfs/nfsmount.h>
71 #include <nfs/nfsdiskless.h>
72 #include <nfs/nfs_var.h>
73 
74 /*
75  * There are two implementations of NFS diskless boot.
76  * This implementation uses Sun RPC/bootparams, and the
77  * the other uses BOOTP (RFC951 - see nfs_bootdhcp.c).
78  *
79  * The Sun-style boot sequence goes as follows:
80  * (1) Use RARP to get our interface address
81  * (2) Use RPC/bootparam/whoami to get our hostname,
82  *     our IP address, and the server's IP address.
83  * (3) Use RPC/bootparam/getfile to get the root path
84  * (4) Use RPC/mountd to get the root file handle
85  * (5) Use RPC/bootparam/getfile to get the swap path
86  * (6) Use RPC/mountd to get the swap file handle
87  */
88 
89 /* bootparam RPC */
90 static int bp_whoami (struct sockaddr_in *bpsin,
91 	struct in_addr *my_ip, struct in_addr *gw_ip, struct lwp *l);
92 static int bp_getfile (struct sockaddr_in *bpsin, const char *key,
93 	struct nfs_dlmount *ndm, struct lwp *l);
94 
95 
96 /*
97  * Get client name, gateway address, then
98  * get root and swap server:pathname info.
99  * RPCs: bootparam/whoami, bootparam/getfile
100  *
101  * Use the old broadcast address for the WHOAMI
102  * call because we do not yet know our netmask.
103  * The server address returned by the WHOAMI call
104  * is used for all subsequent bootparam RPCs.
105  */
106 int
107 nfs_bootparam(struct nfs_diskless *nd, struct lwp *lwp, int *flags)
108 {
109 	struct ifnet *ifp = nd->nd_ifp;
110 	struct in_addr my_ip, arps_ip, gw_ip;
111 	struct sockaddr_in bp_sin;
112 	struct sockaddr_in *sin;
113 #ifndef NFS_BOOTPARAM_NOGATEWAY
114 	struct nfs_dlmount *gw_ndm = 0;
115 	char *p;
116 	u_int32_t mask;
117 #endif
118 	int error;
119 
120 	/*
121 	 * Bring up the interface. (just set the "up" flag)
122 	 */
123 	error = nfs_boot_ifupdown(ifp, lwp, 1);
124 	if (error) {
125 		printf("nfs_boot: SIFFLAGS, error=%d\n", error);
126 		return (error);
127 	}
128 
129 	error = EADDRNOTAVAIL;
130 #if NARP > 0
131 	if (ifp->if_type == IFT_ETHER || ifp->if_type == IFT_FDDI) {
132 		/*
133 		 * Do RARP for the interface address.
134 		 */
135 		error = revarpwhoarewe(ifp, &arps_ip, &my_ip);
136 	}
137 #endif
138 	if (error) {
139 		printf("revarp failed, error=%d\n", error);
140 		goto out;
141 	}
142 
143 	if (!(*flags & NFS_BOOT_HAS_MYIP)) {
144 		nd->nd_myip.s_addr = my_ip.s_addr;
145 		printf("nfs_boot: client_addr=%s", inet_ntoa(my_ip));
146 		printf(" (RARP from %s)\n", inet_ntoa(arps_ip));
147 		*flags |= NFS_BOOT_HAS_MYIP;
148 	}
149 
150 	/*
151 	 * Do enough of ifconfig(8) so that the chosen interface
152 	 * can talk to the servers.  (just set the address)
153 	 */
154 	error = nfs_boot_setaddress(ifp, lwp, my_ip.s_addr,
155 				    INADDR_ANY, INADDR_ANY);
156 	if (error) {
157 		printf("nfs_boot: set ifaddr, error=%d\n", error);
158 		goto out;
159 	}
160 
161 	/*
162 	 * Get client name and gateway address.
163 	 * RPC: bootparam/whoami
164 	 * Use the old broadcast address for the WHOAMI
165 	 * call because we do not yet know our netmask.
166 	 * The server address returned by the WHOAMI call
167 	 * is used for all subsequent booptaram RPCs.
168 	 */
169 	sin = &bp_sin;
170 	memset((void *)sin, 0, sizeof(*sin));
171 	sin->sin_len = sizeof(*sin);
172 	sin->sin_family = AF_INET;
173 	sin->sin_addr.s_addr = INADDR_BROADCAST;
174 
175 	/* Do the RPC/bootparam/whoami. */
176 	error = bp_whoami(sin, &my_ip, &gw_ip, lwp);
177 	if (error) {
178 		printf("nfs_boot: bootparam whoami, error=%d\n", error);
179 		goto delout;
180 	}
181 	*flags |= NFS_BOOT_HAS_SERVADDR | NFS_BOOT_HAS_SERVER;
182 	printf("nfs_boot: server_addr=%s\n", inet_ntoa(sin->sin_addr));
183 	printf("nfs_boot: hostname=%s\n", hostname);
184 
185 	/*
186 	 * Now fetch the server:pathname strings and server IP
187 	 * for root and swap.  Missing swap is not fatal.
188 	 */
189 	error = bp_getfile(sin, "root", &nd->nd_root, lwp);
190 	if (error) {
191 		printf("nfs_boot: bootparam get root: %d\n", error);
192 		goto delout;
193 	}
194 	*flags |= NFS_BOOT_HAS_ROOTPATH;
195 
196 #ifndef NFS_BOOTPARAM_NOGATEWAY
197 	gw_ndm = kmem_alloc(sizeof(*gw_ndm), KM_SLEEP);
198 	memset((void *)gw_ndm, 0, sizeof(*gw_ndm));
199 	error = bp_getfile(sin, "gateway", gw_ndm, lwp);
200 	if (error) {
201 		/* No gateway supplied. No error, but try fallback. */
202 		error = 0;
203 		goto nogwrepl;
204 	}
205 	sin = (struct sockaddr_in *) &gw_ndm->ndm_saddr;
206 	if (sin->sin_addr.s_addr == 0)
207 		goto out;	/* no gateway */
208 
209 	/* OK, we have a gateway! */
210 	printf("nfs_boot: gateway=%s\n", inet_ntoa(sin->sin_addr));
211 	/* Just save it.  Caller adds the route. */
212 	nd->nd_gwip = sin->sin_addr;
213 	*flags |= NFS_BOOT_HAS_GWIP;
214 
215 	/* Look for a mask string after the colon. */
216 	p = strchr(gw_ndm->ndm_host, ':');
217 	if (p == 0)
218 		goto out;	/* no netmask */
219 	/* have pathname */
220 	p++;	/* skip ':' */
221 	mask = inet_addr(p);	/* libkern */
222 	if (mask == 0)
223 		goto out;	/* no netmask */
224 
225 	/* Have a netmask too!  Save it; update the I/F. */
226 	nd->nd_mask.s_addr = mask;
227 	*flags |= NFS_BOOT_HAS_MASK;
228 	printf("nfs_boot: my_mask=%s\n", inet_ntoa(nd->nd_mask));
229 	(void)  nfs_boot_deladdress(ifp, lwp, my_ip.s_addr);
230 	error = nfs_boot_setaddress(ifp, lwp, my_ip.s_addr,
231 				    mask, INADDR_ANY);
232 	if (error) {
233 		printf("nfs_boot: set ifmask, error=%d\n", error);
234 		goto out;
235 	}
236 	goto gwok;
237 nogwrepl:
238 #endif
239 #ifdef NFS_BOOT_GATEWAY
240 	/*
241 	 * Note: we normally ignore the gateway address returned
242 	 * by the "bootparam/whoami" RPC above, because many old
243 	 * bootparam servers supply a bogus gateway value.
244 	 *
245 	 * These deficiencies in the bootparam RPC interface are
246 	 * circumvented by using the bootparam/getfile RPC.  The
247 	 * parameter "gateway" is requested, and if its returned,
248 	 * we use the "server" part of the reply as the gateway,
249 	 * and use the "pathname" part of the reply as the mask.
250 	 * (The mask comes to us as a string.)
251 	 */
252 	if (gw_ip.s_addr) {
253 		/* Our caller will add the route. */
254 		nd->nd_gwip = gw_ip;
255 		*flags |= NFS_BOOT_HAS_GWIP;
256 	}
257 #endif
258 
259 delout:
260 	if (error)
261 		(void) nfs_boot_deladdress(ifp, lwp, my_ip.s_addr);
262 out:
263 	if (error) {
264 		(void) nfs_boot_ifupdown(ifp, lwp, 0);
265 		nfs_boot_flushrt(ifp);
266 	}
267 #ifndef NFS_BOOTPARAM_NOGATEWAY
268 gwok:
269 	if (gw_ndm)
270 		kmem_free(gw_ndm, sizeof(*gw_ndm));
271 #endif
272 	if ((*flags & NFS_BOOT_ALLINFO) != NFS_BOOT_ALLINFO)
273 		return error ? error : EADDRNOTAVAIL;
274 
275 	return (error);
276 }
277 
278 
279 /*
280  * RPC: bootparam/whoami
281  * Given client IP address, get:
282  *	client name	(hostname)
283  *	domain name (domainname)
284  *	gateway address
285  *
286  * The hostname and domainname are set here for convenience.
287  *
288  * Note - bpsin is initialized to the broadcast address,
289  * and will be replaced with the bootparam server address
290  * after this call is complete.  Have to use PMAP_PROC_CALL
291  * to make sure we get responses only from a servers that
292  * know about us (don't want to broadcast a getport call).
293  */
294 static int
295 bp_whoami(struct sockaddr_in *bpsin, struct in_addr *my_ip,
296 	struct in_addr *gw_ip, struct lwp *l)
297 {
298 	/* RPC structures for PMAPPROC_CALLIT */
299 	struct whoami_call {
300 		u_int32_t call_prog;
301 		u_int32_t call_vers;
302 		u_int32_t call_proc;
303 		u_int32_t call_arglen;
304 	} *call;
305 	struct callit_reply {
306 		u_int32_t port;
307 		u_int32_t encap_len;
308 		/* encapsulated data here */
309 	} *reply;
310 
311 	struct mbuf *m, *from;
312 	struct sockaddr_in *sin;
313 	int error;
314 	int16_t port;
315 
316 	/*
317 	 * Build request message for PMAPPROC_CALLIT.
318 	 */
319 	m = m_get(M_WAIT, MT_DATA);
320 	call = mtod(m, struct whoami_call *);
321 	m->m_len = sizeof(*call);
322 	call->call_prog = txdr_unsigned(BOOTPARAM_PROG);
323 	call->call_vers = txdr_unsigned(BOOTPARAM_VERS);
324 	call->call_proc = txdr_unsigned(BOOTPARAM_WHOAMI);
325 
326 	/*
327 	 * append encapsulated data (client IP address)
328 	 */
329 	m->m_next = xdr_inaddr_encode(my_ip);
330 	call->call_arglen = txdr_unsigned(m->m_next->m_len);
331 
332 	/* RPC: portmap/callit */
333 	bpsin->sin_port = htons(PMAPPORT);
334 	error = krpc_call(bpsin, PMAPPROG, PMAPVERS,
335 			PMAPPROC_CALLIT, &m, &from, l);
336 	if (error) {
337 		m_freem(m);
338 		return error;
339 	}
340 
341 	/*
342 	 * Parse result message.
343 	 */
344 	if (m->m_len < sizeof(*reply)) {
345 		m = m_pullup(m, sizeof(*reply));
346 		if (m == NULL)
347 			goto bad;
348 	}
349 	reply = mtod(m, struct callit_reply *);
350 	port = fxdr_unsigned(u_int32_t, reply->port);
351 	m_adj(m, sizeof(*reply));
352 
353 	/*
354 	 * Save bootparam server address
355 	 */
356 	sin = mtod(from, struct sockaddr_in *);
357 	bpsin->sin_port = htons(port);
358 	bpsin->sin_addr.s_addr = sin->sin_addr.s_addr;
359 
360 	/* client name */
361 	hostnamelen = MAXHOSTNAMELEN-1;
362 	m = xdr_string_decode(m, hostname, &hostnamelen);
363 	if (m == NULL)
364 		goto bad;
365 
366 	/* domain name */
367 	domainnamelen = MAXHOSTNAMELEN-1;
368 	m = xdr_string_decode(m, domainname, &domainnamelen);
369 	if (m == NULL)
370 		goto bad;
371 
372 	/* gateway address */
373 	m = xdr_inaddr_decode(m, gw_ip);
374 	if (m == NULL)
375 		goto bad;
376 
377 	/* success */
378 	goto out;
379 
380 bad:
381 	printf("nfs_boot: bootparam_whoami: bad reply\n");
382 	error = EBADRPC;
383 
384 out:
385 	m_freem(from);
386 	if (m)
387 		m_freem(m);
388 	return(error);
389 }
390 
391 
392 /*
393  * RPC: bootparam/getfile
394  * Given client name and file "key", get:
395  *	server name
396  *	server IP address
397  *	server pathname
398  */
399 static int
400 bp_getfile(struct sockaddr_in *bpsin, const char *key,
401 	struct nfs_dlmount *ndm, struct lwp *l)
402 {
403 	char pathname[MNAMELEN];
404 	struct in_addr inaddr;
405 	struct sockaddr_in *sin;
406 	struct mbuf *m;
407 	char *serv_name;
408 	int error, sn_len, path_len;
409 
410 	/*
411 	 * Build request message.
412 	 */
413 
414 	/* client name (hostname) */
415 	m  = xdr_string_encode(hostname, hostnamelen);
416 	if (m == NULL)
417 		return (ENOMEM);
418 
419 	/* key name (root or swap) */
420 	/*XXXUNCONST*/
421 	m->m_next = xdr_string_encode(__UNCONST(key), strlen(key));
422 	if (m->m_next == NULL)
423 		return (ENOMEM);
424 
425 	/* RPC: bootparam/getfile */
426 	error = krpc_call(bpsin, BOOTPARAM_PROG, BOOTPARAM_VERS,
427 	                  BOOTPARAM_GETFILE, &m, NULL, l);
428 	if (error)
429 		return error;
430 
431 	/*
432 	 * Parse result message.
433 	 */
434 
435 	/* server name */
436 	serv_name = &ndm->ndm_host[0];
437 	sn_len = sizeof(ndm->ndm_host) - 1;
438 	m = xdr_string_decode(m, serv_name, &sn_len);
439 	if (m == NULL)
440 		goto bad;
441 
442 	/* server IP address (mountd/NFS) */
443 	m = xdr_inaddr_decode(m, &inaddr);
444 	if (m == NULL)
445 		goto bad;
446 
447 	/* server pathname */
448 	path_len = sizeof(pathname) - 1;
449 	m = xdr_string_decode(m, pathname, &path_len);
450 	if (m == NULL)
451 		goto bad;
452 
453 	/*
454 	 * Store the results in the nfs_dlmount.
455 	 * The strings become "server:pathname"
456 	 */
457 	sin = (struct sockaddr_in *) &ndm->ndm_saddr;
458 	memset((void *)sin, 0, sizeof(*sin));
459 	sin->sin_len = sizeof(*sin);
460 	sin->sin_family = AF_INET;
461 	sin->sin_addr = inaddr;
462 	if ((sn_len + 1 + path_len + 1) > sizeof(ndm->ndm_host)) {
463 		printf("nfs_boot: getfile name too long\n");
464 		error = EIO;
465 		goto out;
466 	}
467 	ndm->ndm_host[sn_len] = ':';
468 	memcpy(ndm->ndm_host + sn_len + 1, pathname, path_len + 1);
469 
470 	/* success */
471 	goto out;
472 
473 bad:
474 	printf("nfs_boot: bootparam_getfile: bad reply\n");
475 	error = EBADRPC;
476 
477 out:
478 	m_freem(m);
479 	return(0);
480 }
481