1 /*
2 * $Id: nfsroot.c,v 1.45 1998/03/07 10:44:46 mj Exp $
3 *
4 * Copyright (C) 1995, 1996 Gero Kuhlmann <gero@gkminix.han.de>
5 *
6 * Allow an NFS filesystem to be mounted as root. The way this works is:
7 * (1) Use the IP autoconfig mechanism to set local IP addresses and routes.
8 * (2) Handle RPC negotiation with the system which replied to RARP or
9 * was reported as a boot server by BOOTP or manually.
10 * (3) The actual mounting is done later, when init() is running.
11 *
12 *
13 * Changes:
14 *
15 * Alan Cox : Removed get_address name clash with FPU.
16 * Alan Cox : Reformatted a bit.
17 * Gero Kuhlmann : Code cleanup
18 * Michael Rausch : Fixed recognition of an incoming RARP answer.
19 * Martin Mares : (2.0) Auto-configuration via BOOTP supported.
20 * Martin Mares : Manual selection of interface & BOOTP/RARP.
21 * Martin Mares : Using network routes instead of host routes,
22 * allowing the default configuration to be used
23 * for normal operation of the host.
24 * Martin Mares : Randomized timer with exponential backoff
25 * installed to minimize network congestion.
26 * Martin Mares : Code cleanup.
27 * Martin Mares : (2.1) BOOTP and RARP made configuration options.
28 * Martin Mares : Server hostname generation fixed.
29 * Gerd Knorr : Fixed wired inode handling
30 * Martin Mares : (2.2) "0.0.0.0" addresses from command line ignored.
31 * Martin Mares : RARP replies not tested for server address.
32 * Gero Kuhlmann : (2.3) Some bug fixes and code cleanup again (please
33 * send me your new patches _before_ bothering
34 * Linus so that I don' always have to cleanup
35 * _afterwards_ - thanks)
36 * Gero Kuhlmann : Last changes of Martin Mares undone.
37 * Gero Kuhlmann : RARP replies are tested for specified server
38 * again. However, it's now possible to have
39 * different RARP and NFS servers.
40 * Gero Kuhlmann : "0.0.0.0" addresses from command line are
41 * now mapped to INADDR_NONE.
42 * Gero Kuhlmann : Fixed a bug which prevented BOOTP path name
43 * from being used (thanks to Leo Spiekman)
44 * Andy Walker : Allow to specify the NFS server in nfs_root
45 * without giving a path name
46 * Swen Thümmler : Allow to specify the NFS options in nfs_root
47 * without giving a path name. Fix BOOTP request
48 * for domainname (domainname is NIS domain, not
49 * DNS domain!). Skip dummy devices for BOOTP.
50 * Jacek Zapala : Fixed a bug which prevented server-ip address
51 * from nfsroot parameter from being used.
52 * Olaf Kirch : Adapted to new NFS code.
53 * Jakub Jelinek : Free used code segment.
54 * Marko Kohtala : Fixed some bugs.
55 * Martin Mares : Debug message cleanup
56 * Martin Mares : Changed to use the new generic IP layer autoconfig
57 * code. BOOTP and RARP moved there.
58 * Martin Mares : Default path now contains host name instead of
59 * host IP address (but host name defaults to IP
60 * address anyway).
61 * Martin Mares : Use root_server_addr appropriately during setup.
62 * Martin Mares : Rewrote parameter parsing, now hopefully giving
63 * correct overriding.
64 * Trond Myklebust : Add in preliminary support for NFSv3 and TCP.
65 * Fix bug in root_nfs_addr(). nfs_data.namlen
66 * is NOT for the length of the hostname.
67 */
68
69 #include <linux/config.h>
70 #include <linux/types.h>
71 #include <linux/string.h>
72 #include <linux/kernel.h>
73 #include <linux/sched.h>
74 #include <linux/fs.h>
75 #include <linux/init.h>
76 #include <linux/sunrpc/clnt.h>
77 #include <linux/nfs.h>
78 #include <linux/nfs_fs.h>
79 #include <linux/nfs_mount.h>
80 #include <linux/in.h>
81 #include <linux/inet.h>
82 #include <linux/major.h>
83 #include <linux/utsname.h>
84 #include <net/ipconfig.h>
85
86 /* Define this to allow debugging output */
87 #undef NFSROOT_DEBUG
88 #define NFSDBG_FACILITY NFSDBG_ROOT
89
90 /* Default path we try to mount. "%s" gets replaced by our IP address */
91 #define NFS_ROOT "/tftpboot/%s"
92
93 /* Parameters passed from the kernel command line */
94 static char nfs_root_name[256] __initdata = "";
95
96 /* Address of NFS server */
97 static __u32 servaddr __initdata = 0;
98
99 /* Name of directory to mount */
100 static char nfs_path[NFS_MAXPATHLEN] __initdata = { 0, };
101
102 /* NFS-related data */
103 static struct nfs_mount_data nfs_data __initdata = { 0, };/* NFS mount info */
104 static int nfs_port __initdata = 0; /* Port to connect to for NFS */
105 static int mount_port __initdata = 0; /* Mount daemon port number */
106
107
108 /***************************************************************************
109
110 Parsing of options
111
112 ***************************************************************************/
113
114 /*
115 * The following integer options are recognized
116 */
117 static struct nfs_int_opts {
118 char *name;
119 int *val;
120 } root_int_opts[] __initdata = {
121 { "port", &nfs_port },
122 { "rsize", &nfs_data.rsize },
123 { "wsize", &nfs_data.wsize },
124 { "timeo", &nfs_data.timeo },
125 { "retrans", &nfs_data.retrans },
126 { "acregmin", &nfs_data.acregmin },
127 { "acregmax", &nfs_data.acregmax },
128 { "acdirmin", &nfs_data.acdirmin },
129 { "acdirmax", &nfs_data.acdirmax },
130 { NULL, NULL }
131 };
132
133
134 /*
135 * And now the flag options
136 */
137 static struct nfs_bool_opts {
138 char *name;
139 int and_mask;
140 int or_mask;
141 } root_bool_opts[] __initdata = {
142 { "soft", ~NFS_MOUNT_SOFT, NFS_MOUNT_SOFT },
143 { "hard", ~NFS_MOUNT_SOFT, 0 },
144 { "intr", ~NFS_MOUNT_INTR, NFS_MOUNT_INTR },
145 { "nointr", ~NFS_MOUNT_INTR, 0 },
146 { "posix", ~NFS_MOUNT_POSIX, NFS_MOUNT_POSIX },
147 { "noposix", ~NFS_MOUNT_POSIX, 0 },
148 { "cto", ~NFS_MOUNT_NOCTO, 0 },
149 { "nocto", ~NFS_MOUNT_NOCTO, NFS_MOUNT_NOCTO },
150 { "ac", ~NFS_MOUNT_NOAC, 0 },
151 { "noac", ~NFS_MOUNT_NOAC, NFS_MOUNT_NOAC },
152 { "lock", ~NFS_MOUNT_NONLM, 0 },
153 { "nolock", ~NFS_MOUNT_NONLM, NFS_MOUNT_NONLM },
154 #ifdef CONFIG_NFS_V3
155 { "v2", ~NFS_MOUNT_VER3, 0 },
156 { "v3", ~NFS_MOUNT_VER3, NFS_MOUNT_VER3 },
157 #endif
158 { "udp", ~NFS_MOUNT_TCP, 0 },
159 { "tcp", ~NFS_MOUNT_TCP, NFS_MOUNT_TCP },
160 { "broken_suid",~NFS_MOUNT_BROKEN_SUID, NFS_MOUNT_BROKEN_SUID },
161 { NULL, 0, 0 }
162 };
163
164
165 /*
166 * Extract IP address from the parameter string if needed. Note that we
167 * need to have root_server_addr set _before_ IPConfig gets called as it
168 * can override it.
169 */
170 static void __init root_nfs_parse_addr(char *name)
171 {
172 int octets = 0;
173 char *cp, *cq;
174
175 cp = cq = name;
176 while (octets < 4) {
177 while (*cp >= '' && *cp <= '9')
178 cp++;
179 if (cp == cq || cp - cq > 3)
180 break;
181 if (*cp == '.' || octets == 3)
182 octets++;
183 if (octets < 4)
184 cp++;
185 cq = cp;
186 }
187 if (octets == 4 && (*cp == ':' || *cp == '\0')) {
188 if (*cp == ':')
189 *cp++ = '\0';
190 root_server_addr = in_aton(name);
191 strcpy(name, cp);
192 }
193 }
194
195
196 /*
197 * Parse option string.
198 */
199 static void __init root_nfs_parse(char *name, char *buf)
200 {
201 char *options, *val, *cp;
202
203 if ((options = strchr(name, ','))) {
204 *options++ = 0;
205 cp = strtok(options, ",");
206 while (cp) {
207 if ((val = strchr(cp, '='))) {
208 struct nfs_int_opts *opts = root_int_opts;
209 *val++ = '\0';
210 while (opts->name && strcmp(opts->name, cp))
211 opts++;
212 if (opts->name)
213 *(opts->val) = (int) simple_strtoul(val, NULL, 10);
214 } else {
215 struct nfs_bool_opts *opts = root_bool_opts;
216 while (opts->name && strcmp(opts->name, cp))
217 opts++;
218 if (opts->name) {
219 nfs_data.flags &= opts->and_mask;
220 nfs_data.flags |= opts->or_mask;
221 }
222 }
223 cp = strtok(NULL, ",");
224 }
225 }
226 if (name[0] && strcmp(name, "default")) {
227 strncpy(buf, name, NFS_MAXPATHLEN-1);
228 buf[NFS_MAXPATHLEN-1] = 0;
229 }
230 }
231
232
233 /*
234 * Prepare the NFS data structure and parse all options.
235 */
236 static int __init root_nfs_name(char *name)
237 {
238 char buf[NFS_MAXPATHLEN];
239 char *cp;
240
241 /* Set some default values */
242 memset(&nfs_data, 0, sizeof(nfs_data));
243 nfs_port = -1;
244 nfs_data.version = NFS_MOUNT_VERSION;
245 nfs_data.flags = NFS_MOUNT_NONLM; /* No lockd in nfs root yet */
246 nfs_data.rsize = NFS_DEF_FILE_IO_BUFFER_SIZE;
247 nfs_data.wsize = NFS_DEF_FILE_IO_BUFFER_SIZE;
248 nfs_data.bsize = 0;
249 nfs_data.timeo = 7;
250 nfs_data.retrans = 3;
251 nfs_data.acregmin = 3;
252 nfs_data.acregmax = 60;
253 nfs_data.acdirmin = 30;
254 nfs_data.acdirmax = 60;
255 strcpy(buf, NFS_ROOT);
256
257 /* Process options received from the remote server */
258 root_nfs_parse(root_server_path, buf);
259
260 /* Override them by options set on kernel command-line */
261 root_nfs_parse(name, buf);
262
263 cp = system_utsname.nodename;
264 if (strlen(buf) + strlen(cp) > NFS_MAXPATHLEN) {
265 printk(KERN_ERR "Root-NFS: Pathname for remote directory too long.\n");
266 return -1;
267 }
268 sprintf(nfs_path, buf, cp);
269
270 return 1;
271 }
272
273
274 /*
275 * Get NFS server address.
276 */
277 static int __init root_nfs_addr(void)
278 {
279 if ((servaddr = root_server_addr) == INADDR_NONE) {
280 printk(KERN_ERR "Root-NFS: No NFS server available, giving up.\n");
281 return -1;
282 }
283
284 strncpy(nfs_data.hostname, in_ntoa(servaddr), sizeof(nfs_data.hostname)-1);
285 return 0;
286 }
287
288 /*
289 * Tell the user what's going on.
290 */
291 #ifdef NFSROOT_DEBUG
292 static void __init root_nfs_print(void)
293 {
294 printk(KERN_NOTICE "Root-NFS: Mounting %s on server %s as root\n",
295 nfs_path, nfs_data.hostname);
296 printk(KERN_NOTICE "Root-NFS: rsize = %d, wsize = %d, timeo = %d, retrans = %d\n",
297 nfs_data.rsize, nfs_data.wsize, nfs_data.timeo, nfs_data.retrans);
298 printk(KERN_NOTICE "Root-NFS: acreg (min,max) = (%d,%d), acdir (min,max) = (%d,%d)\n",
299 nfs_data.acregmin, nfs_data.acregmax,
300 nfs_data.acdirmin, nfs_data.acdirmax);
301 printk(KERN_NOTICE "Root-NFS: nfsd port = %d, mountd port = %d, flags = %08x\n",
302 nfs_port, mount_port, nfs_data.flags);
303 }
304 #endif
305
306
307 int __init root_nfs_init(void)
308 {
309 #ifdef NFSROOT_DEBUG
310 nfs_debug |= NFSDBG_ROOT;
311 #endif
312
313 /*
314 * Decode the root directory path name and NFS options from
315 * the kernel command line. This has to go here in order to
316 * be able to use the client IP address for the remote root
317 * directory (necessary for pure RARP booting).
318 */
319 if (root_nfs_name(nfs_root_name) < 0 ||
320 root_nfs_addr() < 0)
321 return -1;
322
323 #ifdef NFSROOT_DEBUG
324 root_nfs_print();
325 #endif
326
327 return 0;
328 }
329
330
331 /*
332 * Parse NFS server and directory information passed on the kernel
333 * command line.
334 */
335 int __init nfs_root_setup(char *line)
336 {
337 ROOT_DEV = MKDEV(UNNAMED_MAJOR, 255);
338 if (line[0] == '/' || line[0] == ',' || (line[0] >= '' && line[0] <= '9')) {
339 strncpy(nfs_root_name, line, sizeof(nfs_root_name));
340 nfs_root_name[sizeof(nfs_root_name)-1] = '\0';
341 } else {
342 int n = strlen(line) + strlen(NFS_ROOT);
343 if (n >= sizeof(nfs_root_name))
344 line[sizeof(nfs_root_name) - strlen(NFS_ROOT) - 1] = '\0';
345 sprintf(nfs_root_name, NFS_ROOT, line);
346 }
347 root_nfs_parse_addr(nfs_root_name);
348 return 1;
349 }
350
351 __setup("nfsroot=", nfs_root_setup);
352
353 /***************************************************************************
354
355 Routines to actually mount the root directory
356
357 ***************************************************************************/
358
359 /*
360 * Construct sockaddr_in from address and port number.
361 */
362 static inline void
363 set_sockaddr(struct sockaddr_in *sin, __u32 addr, __u16 port)
364 {
365 sin->sin_family = AF_INET;
366 sin->sin_addr.s_addr = addr;
367 sin->sin_port = port;
368 }
369
370 /*
371 * Query server portmapper for the port of a daemon program.
372 */
373 static int __init root_nfs_getport(int program, int version, int proto)
374 {
375 struct sockaddr_in sin;
376
377 printk(KERN_NOTICE "Looking up port of RPC %d/%d on %s\n",
378 program, version, in_ntoa(servaddr));
379 set_sockaddr(&sin, servaddr, 0);
380 return rpc_getport_external(&sin, program, version, proto);
381 }
382
383
384 /*
385 * Use portmapper to find mountd and nfsd port numbers if not overriden
386 * by the user. Use defaults if portmapper is not available.
387 * XXX: Is there any nfs server with no portmapper?
388 */
389 static int __init root_nfs_ports(void)
390 {
391 int port;
392 int nfsd_ver, mountd_ver;
393 int nfsd_port, mountd_port;
394 int proto;
395
396 if (nfs_data.flags & NFS_MOUNT_VER3) {
397 nfsd_ver = NFS3_VERSION;
398 mountd_ver = NFS_MNT3_VERSION;
399 nfsd_port = NFS_PORT;
400 mountd_port = NFS_MNT_PORT;
401 } else {
402 nfsd_ver = NFS2_VERSION;
403 mountd_ver = NFS_MNT_VERSION;
404 nfsd_port = NFS_PORT;
405 mountd_port = NFS_MNT_PORT;
406 }
407
408 proto = (nfs_data.flags & NFS_MOUNT_TCP) ? IPPROTO_TCP : IPPROTO_UDP;
409
410 if (nfs_port < 0) {
411 if ((port = root_nfs_getport(NFS_PROGRAM, nfsd_ver, proto)) < 0) {
412 printk(KERN_ERR "Root-NFS: Unable to get nfsd port "
413 "number from server, using default\n");
414 port = nfsd_port;
415 }
416 nfs_port = htons(port);
417 dprintk("Root-NFS: Portmapper on server returned %d "
418 "as nfsd port\n", port);
419 }
420
421 if ((port = root_nfs_getport(NFS_MNT_PROGRAM, nfsd_ver, proto)) < 0) {
422 printk(KERN_ERR "Root-NFS: Unable to get mountd port "
423 "number from server, using default\n");
424 port = mountd_port;
425 }
426 mount_port = htons(port);
427 dprintk("Root-NFS: mountd port is %d\n", port);
428
429 return 0;
430 }
431
432
433 /*
434 * Get a file handle from the server for the directory which is to be
435 * mounted.
436 */
437 static int __init root_nfs_get_handle(void)
438 {
439 struct sockaddr_in sin;
440 int status;
441
442 set_sockaddr(&sin, servaddr, mount_port);
443 if (nfs_data.flags & NFS_MOUNT_VER3)
444 status = nfs3_mount(&sin, nfs_path, &nfs_data.root);
445 else
446 status = nfs_mount(&sin, nfs_path, &nfs_data.root);
447 if (status < 0)
448 printk(KERN_ERR "Root-NFS: Server returned error %d "
449 "while mounting %s\n", status, nfs_path);
450
451 return status;
452 }
453
454 /*
455 * Get the NFS port numbers and file handle, and return the prepared 'data'
456 * argument for ->read_super() if everything went OK. Return NULL otherwise.
457 */
458 void * __init nfs_root_data(void)
459 {
460 if (root_nfs_init() < 0
461 || root_nfs_ports() < 0
462 || root_nfs_get_handle() < 0)
463 return NULL;
464 set_sockaddr((struct sockaddr_in *) &nfs_data.addr, servaddr, nfs_port);
465 return (void*)&nfs_data;
466 }
467
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