summaryrefslogtreecommitdiffstats
path: root/fs/nfs/nfsroot.c
blob: 169b67907a6556284948944d8b8faecec5081489 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
/*
 *  Copyright (C) 1995, 1996  Gero Kuhlmann <gero@gkminix.han.de>
 *
 *  Allow an NFS filesystem to be mounted as root. The way this works is:
 *     (1) Use the IP autoconfig mechanism to set local IP addresses and routes.
 *     (2) Handle RPC negotiation with the system which replied to RARP or
 *         was reported as a boot server by BOOTP or manually.
 *     (3) The actual mounting is done later, when init() is running.
 *
 *
 *	Changes:
 *
 *	Alan Cox	:	Removed get_address name clash with FPU.
 *	Alan Cox	:	Reformatted a bit.
 *	Gero Kuhlmann	:	Code cleanup
 *	Michael Rausch  :	Fixed recognition of an incoming RARP answer.
 *	Martin Mares	: (2.0)	Auto-configuration via BOOTP supported.
 *	Martin Mares	:	Manual selection of interface & BOOTP/RARP.
 *	Martin Mares	:	Using network routes instead of host routes,
 *				allowing the default configuration to be used
 *				for normal operation of the host.
 *	Martin Mares	:	Randomized timer with exponential backoff
 *				installed to minimize network congestion.
 *	Martin Mares	:	Code cleanup.
 *	Martin Mares	: (2.1)	BOOTP and RARP made configuration options.
 *	Martin Mares	:	Server hostname generation fixed.
 *	Gerd Knorr	:	Fixed wired inode handling
 *	Martin Mares	: (2.2)	"0.0.0.0" addresses from command line ignored.
 *	Martin Mares	:	RARP replies not tested for server address.
 *	Gero Kuhlmann	: (2.3) Some bug fixes and code cleanup again (please
 *				send me your new patches _before_ bothering
 *				Linus so that I don' always have to cleanup
 *				_afterwards_ - thanks)
 *	Gero Kuhlmann	:	Last changes of Martin Mares undone.
 *	Gero Kuhlmann	: 	RARP replies are tested for specified server
 *				again. However, it's now possible to have
 *				different RARP and NFS servers.
 *	Gero Kuhlmann	:	"0.0.0.0" addresses from command line are
 *				now mapped to INADDR_NONE.
 *	Gero Kuhlmann	:	Fixed a bug which prevented BOOTP path name
 *				from being used (thanks to Leo Spiekman)
 *	Andy Walker	:	Allow to specify the NFS server in nfs_root
 *				without giving a path name
 *	Swen Thümmler	:	Allow to specify the NFS options in nfs_root
 *				without giving a path name. Fix BOOTP request
 *				for domainname (domainname is NIS domain, not
 *				DNS domain!). Skip dummy devices for BOOTP.
 *	Jacek Zapala	:	Fixed a bug which prevented server-ip address
 *				from nfsroot parameter from being used.
 *	Olaf Kirch	:	Adapted to new NFS code.
 *	Jakub Jelinek	:	Free used code segment.
 *	Marko Kohtala	:	Fixed some bugs.
 *	Martin Mares	:	Debug message cleanup
 *	Martin Mares	:	Changed to use the new generic IP layer autoconfig
 *				code. BOOTP and RARP moved there.
 *	Martin Mares	:	Default path now contains host name instead of
 *				host IP address (but host name defaults to IP
 *				address anyway).
 *	Martin Mares	:	Use root_server_addr appropriately during setup.
 *	Martin Mares	:	Rewrote parameter parsing, now hopefully giving
 *				correct overriding.
 *	Trond Myklebust :	Add in preliminary support for NFSv3 and TCP.
 *				Fix bug in root_nfs_addr(). nfs_data.namlen
 *				is NOT for the length of the hostname.
 *	Hua Qin		:	Support for mounting root file system via
 *				NFS over TCP.
 *	Fabian Frederick:	Option parser rebuilt (using parser lib)
*/

#include <linux/types.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/time.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/xprtsock.h>
#include <linux/nfs.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_mount.h>
#include <linux/in.h>
#include <linux/major.h>
#include <linux/utsname.h>
#include <linux/inet.h>
#include <linux/root_dev.h>
#include <net/ipconfig.h>
#include <linux/parser.h>

#include "internal.h"

/* Define this to allow debugging output */
#undef NFSROOT_DEBUG
#define NFSDBG_FACILITY NFSDBG_ROOT

/* Default port to use if server is not running a portmapper */
#define NFS_MNT_PORT	627

/* Default path we try to mount. "%s" gets replaced by our IP address */
#define NFS_ROOT		"/tftpboot/%s"

/* Parameters passed from the kernel command line */
static char nfs_root_parms[256] __initdata = "";

/* Address of NFS server */
static __be32 servaddr __initdata = 0;

/* Name of directory to mount */
static char nfs_export_path[NFS_MAXPATHLEN + 1] __initdata = { 0, };

/* NFS-related data */
static struct nfs_mount_data nfs_data __initdata = { 0, };/* NFS mount info */
static int nfs_port __initdata = 0;		/* Port to connect to for NFS */
static int mount_port __initdata = 0;		/* Mount daemon port number */


/***************************************************************************

			     Parsing of options

 ***************************************************************************/

enum {
	/* Options that take integer arguments */
	Opt_port, Opt_rsize, Opt_wsize, Opt_timeo, Opt_retrans, Opt_acregmin,
	Opt_acregmax, Opt_acdirmin, Opt_acdirmax,
	/* Options that take no arguments */
	Opt_soft, Opt_hard, Opt_intr,
	Opt_nointr, Opt_posix, Opt_noposix, Opt_cto, Opt_nocto, Opt_ac, 
	Opt_noac, Opt_lock, Opt_nolock, Opt_v2, Opt_v3, Opt_udp, Opt_tcp,
	Opt_acl, Opt_noacl,
	/* Error token */
	Opt_err
};

static const match_table_t tokens __initconst = {
	{Opt_port, "port=%u"},
	{Opt_rsize, "rsize=%u"},
	{Opt_wsize, "wsize=%u"},
	{Opt_timeo, "timeo=%u"},
	{Opt_retrans, "retrans=%u"},
	{Opt_acregmin, "acregmin=%u"},
	{Opt_acregmax, "acregmax=%u"},
	{Opt_acdirmin, "acdirmin=%u"},
	{Opt_acdirmax, "acdirmax=%u"},
	{Opt_soft, "soft"},
	{Opt_hard, "hard"},
	{Opt_intr, "intr"},
	{Opt_nointr, "nointr"},
	{Opt_posix, "posix"},
	{Opt_noposix, "noposix"},
	{Opt_cto, "cto"},
	{Opt_nocto, "nocto"},
	{Opt_ac, "ac"},
	{Opt_noac, "noac"},
	{Opt_lock, "lock"},
	{Opt_nolock, "nolock"},
	{Opt_v2, "nfsvers=2"},
	{Opt_v2, "v2"},
	{Opt_v3, "nfsvers=3"},
	{Opt_v3, "v3"},
	{Opt_udp, "proto=udp"},
	{Opt_udp, "udp"},
	{Opt_tcp, "proto=tcp"},
	{Opt_tcp, "tcp"},
	{Opt_acl, "acl"},
	{Opt_noacl, "noacl"},
	{Opt_err, NULL}
	
};

/*
 *  Parse option string.
 */

static int __init root_nfs_parse(char *name, char *buf)
{

	char *p;
	substring_t args[MAX_OPT_ARGS];
	int option;

	if (!name)
		return 1;

	/* Set the NFS remote path */
	p = strsep(&name, ",");
	if (p[0] != '\0' && strcmp(p, "default") != 0)
		strlcpy(buf, p, NFS_MAXPATHLEN);

	while ((p = strsep (&name, ",")) != NULL) {
		int token; 
		if (!*p)
			continue;
		token = match_token(p, tokens, args);

		/* %u tokens only. Beware if you add new tokens! */
		if (token < Opt_soft && match_int(&args[0], &option))
			return 0;
		switch (token) {
			case Opt_port:
				nfs_port = option;
				break;
			case Opt_rsize:
				nfs_data.rsize = option;
				break;
			case Opt_wsize:
				nfs_data.wsize = option;
				break;
			case Opt_timeo:
				nfs_data.timeo = option;
				break;
			case Opt_retrans:
				nfs_data.retrans = option;
				break;
			case Opt_acregmin:
				nfs_data.acregmin = option;
				break;
			case Opt_acregmax:
				nfs_data.acregmax = option;
				break;
			case Opt_acdirmin:
				nfs_data.acdirmin = option;
				break;
			case Opt_acdirmax:
				nfs_data.acdirmax = option;
				break;
			case Opt_soft:
				nfs_data.flags |= NFS_MOUNT_SOFT;
				break;
			case Opt_hard:
				nfs_data.flags &= ~NFS_MOUNT_SOFT;
				break;
			case Opt_intr:
			case Opt_nointr:
				break;
			case Opt_posix:
				nfs_data.flags |= NFS_MOUNT_POSIX;
				break;
			case Opt_noposix:
				nfs_data.flags &= ~NFS_MOUNT_POSIX;
				break;
			case Opt_cto:
				nfs_data.flags &= ~NFS_MOUNT_NOCTO;
				break;
			case Opt_nocto:
				nfs_data.flags |= NFS_MOUNT_NOCTO;
				break;
			case Opt_ac:
				nfs_data.flags &= ~NFS_MOUNT_NOAC;
				break;
			case Opt_noac:
				nfs_data.flags |= NFS_MOUNT_NOAC;
				break;
			case Opt_lock:
				nfs_data.flags &= ~NFS_MOUNT_NONLM;
				break;
			case Opt_nolock:
				nfs_data.flags |= NFS_MOUNT_NONLM;
				break;
			case Opt_v2:
				nfs_data.flags &= ~NFS_MOUNT_VER3;
				break;
			case Opt_v3:
				nfs_data.flags |= NFS_MOUNT_VER3;
				break;
			case Opt_udp:
				nfs_data.flags &= ~NFS_MOUNT_TCP;
				break;
			case Opt_tcp:
				nfs_data.flags |= NFS_MOUNT_TCP;
				break;
			case Opt_acl:
				nfs_data.flags &= ~NFS_MOUNT_NOACL;
				break;
			case Opt_noacl:
				nfs_data.flags |= NFS_MOUNT_NOACL;
				break;
			default:
				printk(KERN_WARNING "Root-NFS: unknown "
					"option: %s\n", p);
				return 0;
		}
	}

	return 1;
}

/*
 *  Prepare the NFS data structure and parse all options.
 */
static int __init root_nfs_name(char *name)
{
	static char buf[NFS_MAXPATHLEN] __initdata;
	char *cp;

	/* Set some default values */
	memset(&nfs_data, 0, sizeof(nfs_data));
	nfs_port          = -1;
	nfs_data.version  = NFS_MOUNT_VERSION;
	nfs_data.flags    = NFS_MOUNT_NONLM;	/* No lockd in nfs root yet */
	nfs_data.rsize    = NFS_DEF_FILE_IO_SIZE;
	nfs_data.wsize    = NFS_DEF_FILE_IO_SIZE;
	nfs_data.acregmin = NFS_DEF_ACREGMIN;
	nfs_data.acregmax = NFS_DEF_ACREGMAX;
	nfs_data.acdirmin = NFS_DEF_ACDIRMIN;
	nfs_data.acdirmax = NFS_DEF_ACDIRMAX;
	strcpy(buf, NFS_ROOT);

	/* Process options received from the remote server */
	root_nfs_parse(root_server_path, buf);

	/* Override them by options set on kernel command-line */
	root_nfs_parse(name, buf);

	cp = utsname()->nodename;
	if (strlen(buf) + strlen(cp) > NFS_MAXPATHLEN) {
		printk(KERN_ERR "Root-NFS: Pathname for remote directory too long.\n");
		return -1;
	}
	sprintf(nfs_export_path, buf, cp);

	return 1;
}


/*
 *  Get NFS server address.
 */
static int __init root_nfs_addr(void)
{
	if ((servaddr = root_server_addr) == htonl(INADDR_NONE)) {
		printk(KERN_ERR "Root-NFS: No NFS server available, giving up.\n");
		return -1;
	}

	snprintf(nfs_data.hostname, sizeof(nfs_data.hostname),
		 "%pI4", &servaddr);
	return 0;
}

/*
 *  Tell the user what's going on.
 */
#ifdef NFSROOT_DEBUG
static void __init root_nfs_print(void)
{
	printk(KERN_NOTICE "Root-NFS: Mounting %s on server %s as root\n",
		nfs_export_path, nfs_data.hostname);
	printk(KERN_NOTICE "Root-NFS:     rsize = %d, wsize = %d, timeo = %d, retrans = %d\n",
		nfs_data.rsize, nfs_data.wsize, nfs_data.timeo, nfs_data.retrans);
	printk(KERN_NOTICE "Root-NFS:     acreg (min,max) = (%d,%d), acdir (min,max) = (%d,%d)\n",
		nfs_data.acregmin, nfs_data.acregmax,
		nfs_data.acdirmin, nfs_data.acdirmax);
	printk(KERN_NOTICE "Root-NFS:     nfsd port = %d, mountd port = %d, flags = %08x\n",
		nfs_port, mount_port, nfs_data.flags);
}
#endif


static int __init root_nfs_init(void)
{
#ifdef NFSROOT_DEBUG
	nfs_debug |= NFSDBG_ROOT;
#endif

	/*
	 * Decode the root directory path name and NFS options from
	 * the kernel command line. This has to go here in order to
	 * be able to use the client IP address for the remote root
	 * directory (necessary for pure RARP booting).
	 */
	if (root_nfs_name(nfs_root_parms) < 0 ||
	    root_nfs_addr() < 0)
		return -1;

#ifdef NFSROOT_DEBUG
	root_nfs_print();
#endif

	return 0;
}

/*
 *  Parse NFS server and directory information passed on the kernel
 *  command line.
 *
 *  nfsroot=[<server-ip>:]<root-dir>[,<nfs-options>]
 *
 *  If there is a "%s" token in the <root-dir> string, it is replaced
 *  by the ASCII-representation of the client's IP address.
 */
static int __init nfs_root_setup(char *line)
{
	ROOT_DEV = Root_NFS;

	if (line[0] == '/' || line[0] == ',' || (line[0] >= '0' && line[0] <= '9')) {
		strlcpy(nfs_root_parms, line, sizeof(nfs_root_parms));
	} else {
		size_t n = strlen(line) + sizeof(NFS_ROOT) - 1;
		if (n >= sizeof(nfs_root_parms))
			line[sizeof(nfs_root_parms) - sizeof(NFS_ROOT) - 2] = '\0';
		sprintf(nfs_root_parms, NFS_ROOT, line);
	}

	/*
	 * Extract the IP address of the NFS server containing our
	 * root file system, if one was specified.
	 *
	 * Note: root_nfs_parse_addr() removes the server-ip from
	 *	 nfs_root_parms, if it exists.
	 */
	root_server_addr = root_nfs_parse_addr(nfs_root_parms);

	return 1;
}

__setup("nfsroot=", nfs_root_setup);

/***************************************************************************

	       Routines to actually mount the root directory

 ***************************************************************************/

/*
 *  Construct sockaddr_in from address and port number.
 */
static inline void
set_sockaddr(struct sockaddr_in *sin, __be32 addr, __be16 port)
{
	sin->sin_family = AF_INET;
	sin->sin_addr.s_addr = addr;
	sin->sin_port = port;
}

/*
 *  Query server portmapper for the port of a daemon program.
 */
static int __init root_nfs_getport(int program, int version, int proto)
{
	struct sockaddr_in sin;

	printk(KERN_NOTICE "Looking up port of RPC %d/%d on %pI4\n",
		program, version, &servaddr);
	set_sockaddr(&sin, servaddr, 0);
	return rpcb_getport_sync(&sin, program, version, proto);
}


/*
 *  Use portmapper to find mountd and nfsd port numbers if not overriden
 *  by the user. Use defaults if portmapper is not available.
 *  XXX: Is there any nfs server with no portmapper?
 */
static int __init root_nfs_ports(void)
{
	int port;
	int nfsd_ver, mountd_ver;
	int nfsd_port, mountd_port;
	int proto;

	if (nfs_data.flags & NFS_MOUNT_VER3) {
		nfsd_ver = NFS3_VERSION;
		mountd_ver = NFS_MNT3_VERSION;
		nfsd_port = NFS_PORT;
		mountd_port = NFS_MNT_PORT;
	} else {
		nfsd_ver = NFS2_VERSION;
		mountd_ver = NFS_MNT_VERSION;
		nfsd_port = NFS_PORT;
		mountd_port = NFS_MNT_PORT;
	}

	proto = (nfs_data.flags & NFS_MOUNT_TCP) ? IPPROTO_TCP : IPPROTO_UDP;

	if (nfs_port < 0) {
		if ((port = root_nfs_getport(NFS_PROGRAM, nfsd_ver, proto)) < 0) {
			printk(KERN_ERR "Root-NFS: Unable to get nfsd port "
					"number from server, using default\n");
			port = nfsd_port;
		}
		nfs_port = port;
		dprintk("Root-NFS: Portmapper on server returned %d "
			"as nfsd port\n", port);
	}

	if ((port = root_nfs_getport(NFS_MNT_PROGRAM, mountd_ver, proto)) < 0) {
		printk(KERN_ERR "Root-NFS: Unable to get mountd port "
				"number from server, using default\n");
		port = mountd_port;
	}
	mount_port = port;
	dprintk("Root-NFS: mountd port is %d\n", port);

	return 0;
}


/*
 *  Get a file handle from the server for the directory which is to be
 *  mounted.
 */
static int __init root_nfs_get_handle(void)
{
	struct sockaddr_in sin;
	unsigned int auth_flav_len = 0;
	struct nfs_mount_request request = {
		.sap		= (struct sockaddr *)&sin,
		.salen		= sizeof(sin),
		.dirpath	= nfs_export_path,
		.version	= (nfs_data.flags & NFS_MOUNT_VER3) ?
					NFS_MNT3_VERSION : NFS_MNT_VERSION,
		.protocol	= (nfs_data.flags & NFS_MOUNT_TCP) ?
					XPRT_TRANSPORT_TCP : XPRT_TRANSPORT_UDP,
		.auth_flav_len	= &auth_flav_len,
	};
	int status = -ENOMEM;

	request.fh = nfs_alloc_fhandle();
	if (!request.fh)
		goto out;
	set_sockaddr(&sin, servaddr, htons(mount_port));
	status = nfs_mount(&request);
	if (status < 0)
		printk(KERN_ERR "Root-NFS: Server returned error %d "
				"while mounting %s\n", status, nfs_export_path);
	else {
		nfs_data.root.size = request.fh->size;
		memcpy(&nfs_data.root.data, request.fh->data, request.fh->size);
	}
	nfs_free_fhandle(request.fh);
out:
	return status;
}

/*
 *  Get the NFS port numbers and file handle, and return the prepared 'data'
 *  argument for mount() if everything went OK. Return NULL otherwise.
 */
void * __init nfs_root_data(void)
{
	if (root_nfs_init() < 0
	 || root_nfs_ports() < 0
	 || root_nfs_get_handle() < 0)
		return NULL;
	set_sockaddr((struct sockaddr_in *) &nfs_data.addr, servaddr, htons(nfs_port));
	return (void*)&nfs_data;
}