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1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * linux/fs/nfs/fs_context.c
4  *
5  * Copyright (C) 1992 Rick Sladkey
6  * Conversion to new mount api Copyright (C) David Howells
7  *
8  * NFS mount handling.
9  *
10  * Split from fs/nfs/super.c by David Howells <dhowells@redhat.com>
11  */
12 
13 #include <linux/module.h>
14 #include <linux/fs.h>
15 #include <linux/fs_context.h>
16 #include <linux/fs_parser.h>
17 #include <linux/nfs_fs.h>
18 #include <linux/nfs_mount.h>
19 #include <linux/nfs4_mount.h>
20 #include "nfs.h"
21 #include "internal.h"
22 
23 #define NFSDBG_FACILITY		NFSDBG_MOUNT
24 
25 #if IS_ENABLED(CONFIG_NFS_V3)
26 #define NFS_DEFAULT_VERSION 3
27 #else
28 #define NFS_DEFAULT_VERSION 2
29 #endif
30 
31 #define NFS_MAX_CONNECTIONS 16
32 
33 enum nfs_param {
34 	Opt_ac,
35 	Opt_acdirmax,
36 	Opt_acdirmin,
37 	Opt_acl,
38 	Opt_acregmax,
39 	Opt_acregmin,
40 	Opt_actimeo,
41 	Opt_addr,
42 	Opt_bg,
43 	Opt_bsize,
44 	Opt_clientaddr,
45 	Opt_cto,
46 	Opt_fg,
47 	Opt_fscache,
48 	Opt_fscache_flag,
49 	Opt_hard,
50 	Opt_intr,
51 	Opt_local_lock,
52 	Opt_lock,
53 	Opt_lookupcache,
54 	Opt_migration,
55 	Opt_minorversion,
56 	Opt_mountaddr,
57 	Opt_mounthost,
58 	Opt_mountport,
59 	Opt_mountproto,
60 	Opt_mountvers,
61 	Opt_namelen,
62 	Opt_nconnect,
63 	Opt_max_connect,
64 	Opt_port,
65 	Opt_posix,
66 	Opt_proto,
67 	Opt_rdirplus,
68 	Opt_rdma,
69 	Opt_resvport,
70 	Opt_retrans,
71 	Opt_retry,
72 	Opt_rsize,
73 	Opt_sec,
74 	Opt_sharecache,
75 	Opt_sloppy,
76 	Opt_soft,
77 	Opt_softerr,
78 	Opt_softreval,
79 	Opt_source,
80 	Opt_tcp,
81 	Opt_timeo,
82 	Opt_udp,
83 	Opt_v,
84 	Opt_vers,
85 	Opt_wsize,
86 	Opt_write,
87 };
88 
89 enum {
90 	Opt_local_lock_all,
91 	Opt_local_lock_flock,
92 	Opt_local_lock_none,
93 	Opt_local_lock_posix,
94 };
95 
96 static const struct constant_table nfs_param_enums_local_lock[] = {
97 	{ "all",		Opt_local_lock_all },
98 	{ "flock",	Opt_local_lock_flock },
99 	{ "posix",	Opt_local_lock_posix },
100 	{ "none",		Opt_local_lock_none },
101 	{}
102 };
103 
104 enum {
105 	Opt_lookupcache_all,
106 	Opt_lookupcache_none,
107 	Opt_lookupcache_positive,
108 };
109 
110 static const struct constant_table nfs_param_enums_lookupcache[] = {
111 	{ "all",		Opt_lookupcache_all },
112 	{ "none",		Opt_lookupcache_none },
113 	{ "pos",		Opt_lookupcache_positive },
114 	{ "positive",		Opt_lookupcache_positive },
115 	{}
116 };
117 
118 enum {
119 	Opt_write_lazy,
120 	Opt_write_eager,
121 	Opt_write_wait,
122 };
123 
124 static const struct constant_table nfs_param_enums_write[] = {
125 	{ "lazy",		Opt_write_lazy },
126 	{ "eager",		Opt_write_eager },
127 	{ "wait",		Opt_write_wait },
128 	{}
129 };
130 
131 static const struct fs_parameter_spec nfs_fs_parameters[] = {
132 	fsparam_flag_no("ac",		Opt_ac),
133 	fsparam_u32   ("acdirmax",	Opt_acdirmax),
134 	fsparam_u32   ("acdirmin",	Opt_acdirmin),
135 	fsparam_flag_no("acl",		Opt_acl),
136 	fsparam_u32   ("acregmax",	Opt_acregmax),
137 	fsparam_u32   ("acregmin",	Opt_acregmin),
138 	fsparam_u32   ("actimeo",	Opt_actimeo),
139 	fsparam_string("addr",		Opt_addr),
140 	fsparam_flag  ("bg",		Opt_bg),
141 	fsparam_u32   ("bsize",		Opt_bsize),
142 	fsparam_string("clientaddr",	Opt_clientaddr),
143 	fsparam_flag_no("cto",		Opt_cto),
144 	fsparam_flag  ("fg",		Opt_fg),
145 	fsparam_flag_no("fsc",		Opt_fscache_flag),
146 	fsparam_string("fsc",		Opt_fscache),
147 	fsparam_flag  ("hard",		Opt_hard),
148 	__fsparam(NULL, "intr",		Opt_intr,
149 		  fs_param_neg_with_no|fs_param_deprecated, NULL),
150 	fsparam_enum  ("local_lock",	Opt_local_lock, nfs_param_enums_local_lock),
151 	fsparam_flag_no("lock",		Opt_lock),
152 	fsparam_enum  ("lookupcache",	Opt_lookupcache, nfs_param_enums_lookupcache),
153 	fsparam_flag_no("migration",	Opt_migration),
154 	fsparam_u32   ("minorversion",	Opt_minorversion),
155 	fsparam_string("mountaddr",	Opt_mountaddr),
156 	fsparam_string("mounthost",	Opt_mounthost),
157 	fsparam_u32   ("mountport",	Opt_mountport),
158 	fsparam_string("mountproto",	Opt_mountproto),
159 	fsparam_u32   ("mountvers",	Opt_mountvers),
160 	fsparam_u32   ("namlen",	Opt_namelen),
161 	fsparam_u32   ("nconnect",	Opt_nconnect),
162 	fsparam_u32   ("max_connect",	Opt_max_connect),
163 	fsparam_string("nfsvers",	Opt_vers),
164 	fsparam_u32   ("port",		Opt_port),
165 	fsparam_flag_no("posix",	Opt_posix),
166 	fsparam_string("proto",		Opt_proto),
167 	fsparam_flag_no("rdirplus",	Opt_rdirplus),
168 	fsparam_flag  ("rdma",		Opt_rdma),
169 	fsparam_flag_no("resvport",	Opt_resvport),
170 	fsparam_u32   ("retrans",	Opt_retrans),
171 	fsparam_string("retry",		Opt_retry),
172 	fsparam_u32   ("rsize",		Opt_rsize),
173 	fsparam_string("sec",		Opt_sec),
174 	fsparam_flag_no("sharecache",	Opt_sharecache),
175 	fsparam_flag  ("sloppy",	Opt_sloppy),
176 	fsparam_flag  ("soft",		Opt_soft),
177 	fsparam_flag  ("softerr",	Opt_softerr),
178 	fsparam_flag  ("softreval",	Opt_softreval),
179 	fsparam_string("source",	Opt_source),
180 	fsparam_flag  ("tcp",		Opt_tcp),
181 	fsparam_u32   ("timeo",		Opt_timeo),
182 	fsparam_flag  ("udp",		Opt_udp),
183 	fsparam_flag  ("v2",		Opt_v),
184 	fsparam_flag  ("v3",		Opt_v),
185 	fsparam_flag  ("v4",		Opt_v),
186 	fsparam_flag  ("v4.0",		Opt_v),
187 	fsparam_flag  ("v4.1",		Opt_v),
188 	fsparam_flag  ("v4.2",		Opt_v),
189 	fsparam_string("vers",		Opt_vers),
190 	fsparam_enum  ("write",		Opt_write, nfs_param_enums_write),
191 	fsparam_u32   ("wsize",		Opt_wsize),
192 	{}
193 };
194 
195 enum {
196 	Opt_vers_2,
197 	Opt_vers_3,
198 	Opt_vers_4,
199 	Opt_vers_4_0,
200 	Opt_vers_4_1,
201 	Opt_vers_4_2,
202 };
203 
204 static const struct constant_table nfs_vers_tokens[] = {
205 	{ "2",		Opt_vers_2 },
206 	{ "3",		Opt_vers_3 },
207 	{ "4",		Opt_vers_4 },
208 	{ "4.0",	Opt_vers_4_0 },
209 	{ "4.1",	Opt_vers_4_1 },
210 	{ "4.2",	Opt_vers_4_2 },
211 	{}
212 };
213 
214 enum {
215 	Opt_xprt_rdma,
216 	Opt_xprt_rdma6,
217 	Opt_xprt_tcp,
218 	Opt_xprt_tcp6,
219 	Opt_xprt_udp,
220 	Opt_xprt_udp6,
221 	nr__Opt_xprt
222 };
223 
224 static const struct constant_table nfs_xprt_protocol_tokens[] = {
225 	{ "rdma",	Opt_xprt_rdma },
226 	{ "rdma6",	Opt_xprt_rdma6 },
227 	{ "tcp",	Opt_xprt_tcp },
228 	{ "tcp6",	Opt_xprt_tcp6 },
229 	{ "udp",	Opt_xprt_udp },
230 	{ "udp6",	Opt_xprt_udp6 },
231 	{}
232 };
233 
234 enum {
235 	Opt_sec_krb5,
236 	Opt_sec_krb5i,
237 	Opt_sec_krb5p,
238 	Opt_sec_lkey,
239 	Opt_sec_lkeyi,
240 	Opt_sec_lkeyp,
241 	Opt_sec_none,
242 	Opt_sec_spkm,
243 	Opt_sec_spkmi,
244 	Opt_sec_spkmp,
245 	Opt_sec_sys,
246 	nr__Opt_sec
247 };
248 
249 static const struct constant_table nfs_secflavor_tokens[] = {
250 	{ "krb5",	Opt_sec_krb5 },
251 	{ "krb5i",	Opt_sec_krb5i },
252 	{ "krb5p",	Opt_sec_krb5p },
253 	{ "lkey",	Opt_sec_lkey },
254 	{ "lkeyi",	Opt_sec_lkeyi },
255 	{ "lkeyp",	Opt_sec_lkeyp },
256 	{ "none",	Opt_sec_none },
257 	{ "null",	Opt_sec_none },
258 	{ "spkm3",	Opt_sec_spkm },
259 	{ "spkm3i",	Opt_sec_spkmi },
260 	{ "spkm3p",	Opt_sec_spkmp },
261 	{ "sys",	Opt_sec_sys },
262 	{}
263 };
264 
265 /*
266  * Sanity-check a server address provided by the mount command.
267  *
268  * Address family must be initialized, and address must not be
269  * the ANY address for that family.
270  */
nfs_verify_server_address(struct sockaddr * addr)271 static int nfs_verify_server_address(struct sockaddr *addr)
272 {
273 	switch (addr->sa_family) {
274 	case AF_INET: {
275 		struct sockaddr_in *sa = (struct sockaddr_in *)addr;
276 		return sa->sin_addr.s_addr != htonl(INADDR_ANY);
277 	}
278 	case AF_INET6: {
279 		struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
280 		return !ipv6_addr_any(sa);
281 	}
282 	}
283 
284 	dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
285 	return 0;
286 }
287 
288 #ifdef CONFIG_NFS_DISABLE_UDP_SUPPORT
nfs_server_transport_udp_invalid(const struct nfs_fs_context * ctx)289 static bool nfs_server_transport_udp_invalid(const struct nfs_fs_context *ctx)
290 {
291 	return true;
292 }
293 #else
nfs_server_transport_udp_invalid(const struct nfs_fs_context * ctx)294 static bool nfs_server_transport_udp_invalid(const struct nfs_fs_context *ctx)
295 {
296 	if (ctx->version == 4)
297 		return true;
298 	return false;
299 }
300 #endif
301 
302 /*
303  * Sanity check the NFS transport protocol.
304  */
nfs_validate_transport_protocol(struct fs_context * fc,struct nfs_fs_context * ctx)305 static int nfs_validate_transport_protocol(struct fs_context *fc,
306 					   struct nfs_fs_context *ctx)
307 {
308 	switch (ctx->nfs_server.protocol) {
309 	case XPRT_TRANSPORT_UDP:
310 		if (nfs_server_transport_udp_invalid(ctx))
311 			goto out_invalid_transport_udp;
312 		break;
313 	case XPRT_TRANSPORT_TCP:
314 	case XPRT_TRANSPORT_RDMA:
315 		break;
316 	default:
317 		ctx->nfs_server.protocol = XPRT_TRANSPORT_TCP;
318 	}
319 	return 0;
320 out_invalid_transport_udp:
321 	return nfs_invalf(fc, "NFS: Unsupported transport protocol udp");
322 }
323 
324 /*
325  * For text based NFSv2/v3 mounts, the mount protocol transport default
326  * settings should depend upon the specified NFS transport.
327  */
nfs_set_mount_transport_protocol(struct nfs_fs_context * ctx)328 static void nfs_set_mount_transport_protocol(struct nfs_fs_context *ctx)
329 {
330 	if (ctx->mount_server.protocol == XPRT_TRANSPORT_UDP ||
331 	    ctx->mount_server.protocol == XPRT_TRANSPORT_TCP)
332 			return;
333 	switch (ctx->nfs_server.protocol) {
334 	case XPRT_TRANSPORT_UDP:
335 		ctx->mount_server.protocol = XPRT_TRANSPORT_UDP;
336 		break;
337 	case XPRT_TRANSPORT_TCP:
338 	case XPRT_TRANSPORT_RDMA:
339 		ctx->mount_server.protocol = XPRT_TRANSPORT_TCP;
340 	}
341 }
342 
343 /*
344  * Add 'flavor' to 'auth_info' if not already present.
345  * Returns true if 'flavor' ends up in the list, false otherwise
346  */
nfs_auth_info_add(struct fs_context * fc,struct nfs_auth_info * auth_info,rpc_authflavor_t flavor)347 static int nfs_auth_info_add(struct fs_context *fc,
348 			     struct nfs_auth_info *auth_info,
349 			     rpc_authflavor_t flavor)
350 {
351 	unsigned int i;
352 	unsigned int max_flavor_len = ARRAY_SIZE(auth_info->flavors);
353 
354 	/* make sure this flavor isn't already in the list */
355 	for (i = 0; i < auth_info->flavor_len; i++) {
356 		if (flavor == auth_info->flavors[i])
357 			return 0;
358 	}
359 
360 	if (auth_info->flavor_len + 1 >= max_flavor_len)
361 		return nfs_invalf(fc, "NFS: too many sec= flavors");
362 
363 	auth_info->flavors[auth_info->flavor_len++] = flavor;
364 	return 0;
365 }
366 
367 /*
368  * Parse the value of the 'sec=' option.
369  */
nfs_parse_security_flavors(struct fs_context * fc,struct fs_parameter * param)370 static int nfs_parse_security_flavors(struct fs_context *fc,
371 				      struct fs_parameter *param)
372 {
373 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
374 	rpc_authflavor_t pseudoflavor;
375 	char *string = param->string, *p;
376 	int ret;
377 
378 	dfprintk(MOUNT, "NFS: parsing %s=%s option\n", param->key, param->string);
379 
380 	while ((p = strsep(&string, ":")) != NULL) {
381 		if (!*p)
382 			continue;
383 		switch (lookup_constant(nfs_secflavor_tokens, p, -1)) {
384 		case Opt_sec_none:
385 			pseudoflavor = RPC_AUTH_NULL;
386 			break;
387 		case Opt_sec_sys:
388 			pseudoflavor = RPC_AUTH_UNIX;
389 			break;
390 		case Opt_sec_krb5:
391 			pseudoflavor = RPC_AUTH_GSS_KRB5;
392 			break;
393 		case Opt_sec_krb5i:
394 			pseudoflavor = RPC_AUTH_GSS_KRB5I;
395 			break;
396 		case Opt_sec_krb5p:
397 			pseudoflavor = RPC_AUTH_GSS_KRB5P;
398 			break;
399 		case Opt_sec_lkey:
400 			pseudoflavor = RPC_AUTH_GSS_LKEY;
401 			break;
402 		case Opt_sec_lkeyi:
403 			pseudoflavor = RPC_AUTH_GSS_LKEYI;
404 			break;
405 		case Opt_sec_lkeyp:
406 			pseudoflavor = RPC_AUTH_GSS_LKEYP;
407 			break;
408 		case Opt_sec_spkm:
409 			pseudoflavor = RPC_AUTH_GSS_SPKM;
410 			break;
411 		case Opt_sec_spkmi:
412 			pseudoflavor = RPC_AUTH_GSS_SPKMI;
413 			break;
414 		case Opt_sec_spkmp:
415 			pseudoflavor = RPC_AUTH_GSS_SPKMP;
416 			break;
417 		default:
418 			return nfs_invalf(fc, "NFS: sec=%s option not recognized", p);
419 		}
420 
421 		ret = nfs_auth_info_add(fc, &ctx->auth_info, pseudoflavor);
422 		if (ret < 0)
423 			return ret;
424 	}
425 
426 	return 0;
427 }
428 
nfs_parse_version_string(struct fs_context * fc,const char * string)429 static int nfs_parse_version_string(struct fs_context *fc,
430 				    const char *string)
431 {
432 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
433 
434 	ctx->flags &= ~NFS_MOUNT_VER3;
435 	switch (lookup_constant(nfs_vers_tokens, string, -1)) {
436 	case Opt_vers_2:
437 		ctx->version = 2;
438 		break;
439 	case Opt_vers_3:
440 		ctx->flags |= NFS_MOUNT_VER3;
441 		ctx->version = 3;
442 		break;
443 	case Opt_vers_4:
444 		/* Backward compatibility option. In future,
445 		 * the mount program should always supply
446 		 * a NFSv4 minor version number.
447 		 */
448 		ctx->version = 4;
449 		break;
450 	case Opt_vers_4_0:
451 		ctx->version = 4;
452 		ctx->minorversion = 0;
453 		break;
454 	case Opt_vers_4_1:
455 		ctx->version = 4;
456 		ctx->minorversion = 1;
457 		break;
458 	case Opt_vers_4_2:
459 		ctx->version = 4;
460 		ctx->minorversion = 2;
461 		break;
462 	default:
463 		return nfs_invalf(fc, "NFS: Unsupported NFS version");
464 	}
465 	return 0;
466 }
467 
468 /*
469  * Parse a single mount parameter.
470  */
nfs_fs_context_parse_param(struct fs_context * fc,struct fs_parameter * param)471 static int nfs_fs_context_parse_param(struct fs_context *fc,
472 				      struct fs_parameter *param)
473 {
474 	struct fs_parse_result result;
475 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
476 	unsigned short protofamily, mountfamily;
477 	unsigned int len;
478 	int ret, opt;
479 
480 	dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", param->key);
481 
482 	opt = fs_parse(fc, nfs_fs_parameters, param, &result);
483 	if (opt < 0)
484 		return ctx->sloppy ? 1 : opt;
485 
486 	if (fc->security)
487 		ctx->has_sec_mnt_opts = 1;
488 
489 	switch (opt) {
490 	case Opt_source:
491 		if (fc->source)
492 			return nfs_invalf(fc, "NFS: Multiple sources not supported");
493 		fc->source = param->string;
494 		param->string = NULL;
495 		break;
496 
497 		/*
498 		 * boolean options:  foo/nofoo
499 		 */
500 	case Opt_soft:
501 		ctx->flags |= NFS_MOUNT_SOFT;
502 		ctx->flags &= ~NFS_MOUNT_SOFTERR;
503 		break;
504 	case Opt_softerr:
505 		ctx->flags |= NFS_MOUNT_SOFTERR | NFS_MOUNT_SOFTREVAL;
506 		ctx->flags &= ~NFS_MOUNT_SOFT;
507 		break;
508 	case Opt_hard:
509 		ctx->flags &= ~(NFS_MOUNT_SOFT |
510 				NFS_MOUNT_SOFTERR |
511 				NFS_MOUNT_SOFTREVAL);
512 		break;
513 	case Opt_softreval:
514 		if (result.negated)
515 			ctx->flags &= ~NFS_MOUNT_SOFTREVAL;
516 		else
517 			ctx->flags |= NFS_MOUNT_SOFTREVAL;
518 		break;
519 	case Opt_posix:
520 		if (result.negated)
521 			ctx->flags &= ~NFS_MOUNT_POSIX;
522 		else
523 			ctx->flags |= NFS_MOUNT_POSIX;
524 		break;
525 	case Opt_cto:
526 		if (result.negated)
527 			ctx->flags |= NFS_MOUNT_NOCTO;
528 		else
529 			ctx->flags &= ~NFS_MOUNT_NOCTO;
530 		break;
531 	case Opt_ac:
532 		if (result.negated)
533 			ctx->flags |= NFS_MOUNT_NOAC;
534 		else
535 			ctx->flags &= ~NFS_MOUNT_NOAC;
536 		break;
537 	case Opt_lock:
538 		if (result.negated) {
539 			ctx->flags |= NFS_MOUNT_NONLM;
540 			ctx->flags |= (NFS_MOUNT_LOCAL_FLOCK | NFS_MOUNT_LOCAL_FCNTL);
541 		} else {
542 			ctx->flags &= ~NFS_MOUNT_NONLM;
543 			ctx->flags &= ~(NFS_MOUNT_LOCAL_FLOCK | NFS_MOUNT_LOCAL_FCNTL);
544 		}
545 		break;
546 	case Opt_udp:
547 		ctx->flags &= ~NFS_MOUNT_TCP;
548 		ctx->nfs_server.protocol = XPRT_TRANSPORT_UDP;
549 		break;
550 	case Opt_tcp:
551 	case Opt_rdma:
552 		ctx->flags |= NFS_MOUNT_TCP; /* for side protocols */
553 		ret = xprt_find_transport_ident(param->key);
554 		if (ret < 0)
555 			goto out_bad_transport;
556 		ctx->nfs_server.protocol = ret;
557 		break;
558 	case Opt_acl:
559 		if (result.negated)
560 			ctx->flags |= NFS_MOUNT_NOACL;
561 		else
562 			ctx->flags &= ~NFS_MOUNT_NOACL;
563 		break;
564 	case Opt_rdirplus:
565 		if (result.negated)
566 			ctx->flags |= NFS_MOUNT_NORDIRPLUS;
567 		else
568 			ctx->flags &= ~NFS_MOUNT_NORDIRPLUS;
569 		break;
570 	case Opt_sharecache:
571 		if (result.negated)
572 			ctx->flags |= NFS_MOUNT_UNSHARED;
573 		else
574 			ctx->flags &= ~NFS_MOUNT_UNSHARED;
575 		break;
576 	case Opt_resvport:
577 		if (result.negated)
578 			ctx->flags |= NFS_MOUNT_NORESVPORT;
579 		else
580 			ctx->flags &= ~NFS_MOUNT_NORESVPORT;
581 		break;
582 	case Opt_fscache_flag:
583 		if (result.negated)
584 			ctx->options &= ~NFS_OPTION_FSCACHE;
585 		else
586 			ctx->options |= NFS_OPTION_FSCACHE;
587 		kfree(ctx->fscache_uniq);
588 		ctx->fscache_uniq = NULL;
589 		break;
590 	case Opt_fscache:
591 		ctx->options |= NFS_OPTION_FSCACHE;
592 		kfree(ctx->fscache_uniq);
593 		ctx->fscache_uniq = param->string;
594 		param->string = NULL;
595 		break;
596 	case Opt_migration:
597 		if (result.negated)
598 			ctx->options &= ~NFS_OPTION_MIGRATION;
599 		else
600 			ctx->options |= NFS_OPTION_MIGRATION;
601 		break;
602 
603 		/*
604 		 * options that take numeric values
605 		 */
606 	case Opt_port:
607 		if (result.uint_32 > USHRT_MAX)
608 			goto out_of_bounds;
609 		ctx->nfs_server.port = result.uint_32;
610 		break;
611 	case Opt_rsize:
612 		ctx->rsize = result.uint_32;
613 		break;
614 	case Opt_wsize:
615 		ctx->wsize = result.uint_32;
616 		break;
617 	case Opt_bsize:
618 		ctx->bsize = result.uint_32;
619 		break;
620 	case Opt_timeo:
621 		if (result.uint_32 < 1 || result.uint_32 > INT_MAX)
622 			goto out_of_bounds;
623 		ctx->timeo = result.uint_32;
624 		break;
625 	case Opt_retrans:
626 		if (result.uint_32 > INT_MAX)
627 			goto out_of_bounds;
628 		ctx->retrans = result.uint_32;
629 		break;
630 	case Opt_acregmin:
631 		ctx->acregmin = result.uint_32;
632 		break;
633 	case Opt_acregmax:
634 		ctx->acregmax = result.uint_32;
635 		break;
636 	case Opt_acdirmin:
637 		ctx->acdirmin = result.uint_32;
638 		break;
639 	case Opt_acdirmax:
640 		ctx->acdirmax = result.uint_32;
641 		break;
642 	case Opt_actimeo:
643 		ctx->acregmin = result.uint_32;
644 		ctx->acregmax = result.uint_32;
645 		ctx->acdirmin = result.uint_32;
646 		ctx->acdirmax = result.uint_32;
647 		break;
648 	case Opt_namelen:
649 		ctx->namlen = result.uint_32;
650 		break;
651 	case Opt_mountport:
652 		if (result.uint_32 > USHRT_MAX)
653 			goto out_of_bounds;
654 		ctx->mount_server.port = result.uint_32;
655 		break;
656 	case Opt_mountvers:
657 		if (result.uint_32 < NFS_MNT_VERSION ||
658 		    result.uint_32 > NFS_MNT3_VERSION)
659 			goto out_of_bounds;
660 		ctx->mount_server.version = result.uint_32;
661 		break;
662 	case Opt_minorversion:
663 		if (result.uint_32 > NFS4_MAX_MINOR_VERSION)
664 			goto out_of_bounds;
665 		ctx->minorversion = result.uint_32;
666 		break;
667 
668 		/*
669 		 * options that take text values
670 		 */
671 	case Opt_v:
672 		ret = nfs_parse_version_string(fc, param->key + 1);
673 		if (ret < 0)
674 			return ret;
675 		break;
676 	case Opt_vers:
677 		ret = nfs_parse_version_string(fc, param->string);
678 		if (ret < 0)
679 			return ret;
680 		break;
681 	case Opt_sec:
682 		ret = nfs_parse_security_flavors(fc, param);
683 		if (ret < 0)
684 			return ret;
685 		break;
686 
687 	case Opt_proto:
688 		protofamily = AF_INET;
689 		switch (lookup_constant(nfs_xprt_protocol_tokens, param->string, -1)) {
690 		case Opt_xprt_udp6:
691 			protofamily = AF_INET6;
692 			fallthrough;
693 		case Opt_xprt_udp:
694 			ctx->flags &= ~NFS_MOUNT_TCP;
695 			ctx->nfs_server.protocol = XPRT_TRANSPORT_UDP;
696 			break;
697 		case Opt_xprt_tcp6:
698 			protofamily = AF_INET6;
699 			fallthrough;
700 		case Opt_xprt_tcp:
701 			ctx->flags |= NFS_MOUNT_TCP;
702 			ctx->nfs_server.protocol = XPRT_TRANSPORT_TCP;
703 			break;
704 		case Opt_xprt_rdma6:
705 			protofamily = AF_INET6;
706 			fallthrough;
707 		case Opt_xprt_rdma:
708 			/* vector side protocols to TCP */
709 			ctx->flags |= NFS_MOUNT_TCP;
710 			ret = xprt_find_transport_ident(param->string);
711 			if (ret < 0)
712 				goto out_bad_transport;
713 			ctx->nfs_server.protocol = ret;
714 			break;
715 		default:
716 			goto out_bad_transport;
717 		}
718 
719 		ctx->protofamily = protofamily;
720 		break;
721 
722 	case Opt_mountproto:
723 		mountfamily = AF_INET;
724 		switch (lookup_constant(nfs_xprt_protocol_tokens, param->string, -1)) {
725 		case Opt_xprt_udp6:
726 			mountfamily = AF_INET6;
727 			fallthrough;
728 		case Opt_xprt_udp:
729 			ctx->mount_server.protocol = XPRT_TRANSPORT_UDP;
730 			break;
731 		case Opt_xprt_tcp6:
732 			mountfamily = AF_INET6;
733 			fallthrough;
734 		case Opt_xprt_tcp:
735 			ctx->mount_server.protocol = XPRT_TRANSPORT_TCP;
736 			break;
737 		case Opt_xprt_rdma: /* not used for side protocols */
738 		default:
739 			goto out_bad_transport;
740 		}
741 		ctx->mountfamily = mountfamily;
742 		break;
743 
744 	case Opt_addr:
745 		len = rpc_pton(fc->net_ns, param->string, param->size,
746 			       &ctx->nfs_server.address,
747 			       sizeof(ctx->nfs_server._address));
748 		if (len == 0)
749 			goto out_invalid_address;
750 		ctx->nfs_server.addrlen = len;
751 		break;
752 	case Opt_clientaddr:
753 		kfree(ctx->client_address);
754 		ctx->client_address = param->string;
755 		param->string = NULL;
756 		break;
757 	case Opt_mounthost:
758 		kfree(ctx->mount_server.hostname);
759 		ctx->mount_server.hostname = param->string;
760 		param->string = NULL;
761 		break;
762 	case Opt_mountaddr:
763 		len = rpc_pton(fc->net_ns, param->string, param->size,
764 			       &ctx->mount_server.address,
765 			       sizeof(ctx->mount_server._address));
766 		if (len == 0)
767 			goto out_invalid_address;
768 		ctx->mount_server.addrlen = len;
769 		break;
770 	case Opt_nconnect:
771 		if (result.uint_32 < 1 || result.uint_32 > NFS_MAX_CONNECTIONS)
772 			goto out_of_bounds;
773 		ctx->nfs_server.nconnect = result.uint_32;
774 		break;
775 	case Opt_max_connect:
776 		if (result.uint_32 < 1 || result.uint_32 > NFS_MAX_TRANSPORTS)
777 			goto out_of_bounds;
778 		ctx->nfs_server.max_connect = result.uint_32;
779 		break;
780 	case Opt_lookupcache:
781 		switch (result.uint_32) {
782 		case Opt_lookupcache_all:
783 			ctx->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
784 			break;
785 		case Opt_lookupcache_positive:
786 			ctx->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
787 			ctx->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
788 			break;
789 		case Opt_lookupcache_none:
790 			ctx->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
791 			break;
792 		default:
793 			goto out_invalid_value;
794 		}
795 		break;
796 	case Opt_local_lock:
797 		switch (result.uint_32) {
798 		case Opt_local_lock_all:
799 			ctx->flags |= (NFS_MOUNT_LOCAL_FLOCK |
800 				       NFS_MOUNT_LOCAL_FCNTL);
801 			break;
802 		case Opt_local_lock_flock:
803 			ctx->flags |= NFS_MOUNT_LOCAL_FLOCK;
804 			break;
805 		case Opt_local_lock_posix:
806 			ctx->flags |= NFS_MOUNT_LOCAL_FCNTL;
807 			break;
808 		case Opt_local_lock_none:
809 			ctx->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
810 					NFS_MOUNT_LOCAL_FCNTL);
811 			break;
812 		default:
813 			goto out_invalid_value;
814 		}
815 		break;
816 	case Opt_write:
817 		switch (result.uint_32) {
818 		case Opt_write_lazy:
819 			ctx->flags &=
820 				~(NFS_MOUNT_WRITE_EAGER | NFS_MOUNT_WRITE_WAIT);
821 			break;
822 		case Opt_write_eager:
823 			ctx->flags |= NFS_MOUNT_WRITE_EAGER;
824 			ctx->flags &= ~NFS_MOUNT_WRITE_WAIT;
825 			break;
826 		case Opt_write_wait:
827 			ctx->flags |=
828 				NFS_MOUNT_WRITE_EAGER | NFS_MOUNT_WRITE_WAIT;
829 			break;
830 		default:
831 			goto out_invalid_value;
832 		}
833 		break;
834 
835 		/*
836 		 * Special options
837 		 */
838 	case Opt_sloppy:
839 		ctx->sloppy = true;
840 		dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
841 		break;
842 	}
843 
844 	return 0;
845 
846 out_invalid_value:
847 	return nfs_invalf(fc, "NFS: Bad mount option value specified");
848 out_invalid_address:
849 	return nfs_invalf(fc, "NFS: Bad IP address specified");
850 out_of_bounds:
851 	return nfs_invalf(fc, "NFS: Value for '%s' out of range", param->key);
852 out_bad_transport:
853 	return nfs_invalf(fc, "NFS: Unrecognized transport protocol");
854 }
855 
856 /*
857  * Split fc->source into "hostname:export_path".
858  *
859  * The leftmost colon demarks the split between the server's hostname
860  * and the export path.  If the hostname starts with a left square
861  * bracket, then it may contain colons.
862  *
863  * Note: caller frees hostname and export path, even on error.
864  */
nfs_parse_source(struct fs_context * fc,size_t maxnamlen,size_t maxpathlen)865 static int nfs_parse_source(struct fs_context *fc,
866 			    size_t maxnamlen, size_t maxpathlen)
867 {
868 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
869 	const char *dev_name = fc->source;
870 	size_t len;
871 	const char *end;
872 
873 	if (unlikely(!dev_name || !*dev_name)) {
874 		dfprintk(MOUNT, "NFS: device name not specified\n");
875 		return -EINVAL;
876 	}
877 
878 	/* Is the host name protected with square brakcets? */
879 	if (*dev_name == '[') {
880 		end = strchr(++dev_name, ']');
881 		if (end == NULL || end[1] != ':')
882 			goto out_bad_devname;
883 
884 		len = end - dev_name;
885 		end++;
886 	} else {
887 		const char *comma;
888 
889 		end = strchr(dev_name, ':');
890 		if (end == NULL)
891 			goto out_bad_devname;
892 		len = end - dev_name;
893 
894 		/* kill possible hostname list: not supported */
895 		comma = memchr(dev_name, ',', len);
896 		if (comma)
897 			len = comma - dev_name;
898 	}
899 
900 	if (len > maxnamlen)
901 		goto out_hostname;
902 
903 	kfree(ctx->nfs_server.hostname);
904 
905 	/* N.B. caller will free nfs_server.hostname in all cases */
906 	ctx->nfs_server.hostname = kmemdup_nul(dev_name, len, GFP_KERNEL);
907 	if (!ctx->nfs_server.hostname)
908 		goto out_nomem;
909 	len = strlen(++end);
910 	if (len > maxpathlen)
911 		goto out_path;
912 	ctx->nfs_server.export_path = kmemdup_nul(end, len, GFP_KERNEL);
913 	if (!ctx->nfs_server.export_path)
914 		goto out_nomem;
915 
916 	dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", ctx->nfs_server.export_path);
917 	return 0;
918 
919 out_bad_devname:
920 	return nfs_invalf(fc, "NFS: device name not in host:path format");
921 out_nomem:
922 	nfs_errorf(fc, "NFS: not enough memory to parse device name");
923 	return -ENOMEM;
924 out_hostname:
925 	nfs_errorf(fc, "NFS: server hostname too long");
926 	return -ENAMETOOLONG;
927 out_path:
928 	nfs_errorf(fc, "NFS: export pathname too long");
929 	return -ENAMETOOLONG;
930 }
931 
is_remount_fc(struct fs_context * fc)932 static inline bool is_remount_fc(struct fs_context *fc)
933 {
934 	return fc->root != NULL;
935 }
936 
937 /*
938  * Parse monolithic NFS2/NFS3 mount data
939  * - fills in the mount root filehandle
940  *
941  * For option strings, user space handles the following behaviors:
942  *
943  * + DNS: mapping server host name to IP address ("addr=" option)
944  *
945  * + failure mode: how to behave if a mount request can't be handled
946  *   immediately ("fg/bg" option)
947  *
948  * + retry: how often to retry a mount request ("retry=" option)
949  *
950  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
951  *   mountproto=tcp after mountproto=udp, and so on
952  */
nfs23_parse_monolithic(struct fs_context * fc,struct nfs_mount_data * data)953 static int nfs23_parse_monolithic(struct fs_context *fc,
954 				  struct nfs_mount_data *data)
955 {
956 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
957 	struct nfs_fh *mntfh = ctx->mntfh;
958 	struct sockaddr *sap = (struct sockaddr *)&ctx->nfs_server.address;
959 	int extra_flags = NFS_MOUNT_LEGACY_INTERFACE;
960 	int ret;
961 
962 	if (data == NULL)
963 		goto out_no_data;
964 
965 	ctx->version = NFS_DEFAULT_VERSION;
966 	switch (data->version) {
967 	case 1:
968 		data->namlen = 0;
969 		fallthrough;
970 	case 2:
971 		data->bsize = 0;
972 		fallthrough;
973 	case 3:
974 		if (data->flags & NFS_MOUNT_VER3)
975 			goto out_no_v3;
976 		data->root.size = NFS2_FHSIZE;
977 		memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
978 		/* Turn off security negotiation */
979 		extra_flags |= NFS_MOUNT_SECFLAVOUR;
980 		fallthrough;
981 	case 4:
982 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
983 			goto out_no_sec;
984 		fallthrough;
985 	case 5:
986 		memset(data->context, 0, sizeof(data->context));
987 		fallthrough;
988 	case 6:
989 		if (data->flags & NFS_MOUNT_VER3) {
990 			if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
991 				goto out_invalid_fh;
992 			mntfh->size = data->root.size;
993 			ctx->version = 3;
994 		} else {
995 			mntfh->size = NFS2_FHSIZE;
996 			ctx->version = 2;
997 		}
998 
999 
1000 		memcpy(mntfh->data, data->root.data, mntfh->size);
1001 		if (mntfh->size < sizeof(mntfh->data))
1002 			memset(mntfh->data + mntfh->size, 0,
1003 			       sizeof(mntfh->data) - mntfh->size);
1004 
1005 		/*
1006 		 * for proto == XPRT_TRANSPORT_UDP, which is what uses
1007 		 * to_exponential, implying shift: limit the shift value
1008 		 * to BITS_PER_LONG (majortimeo is unsigned long)
1009 		 */
1010 		if (!(data->flags & NFS_MOUNT_TCP)) /* this will be UDP */
1011 			if (data->retrans >= 64) /* shift value is too large */
1012 				goto out_invalid_data;
1013 
1014 		/*
1015 		 * Translate to nfs_fs_context, which nfs_fill_super
1016 		 * can deal with.
1017 		 */
1018 		ctx->flags	= data->flags & NFS_MOUNT_FLAGMASK;
1019 		ctx->flags	|= extra_flags;
1020 		ctx->rsize	= data->rsize;
1021 		ctx->wsize	= data->wsize;
1022 		ctx->timeo	= data->timeo;
1023 		ctx->retrans	= data->retrans;
1024 		ctx->acregmin	= data->acregmin;
1025 		ctx->acregmax	= data->acregmax;
1026 		ctx->acdirmin	= data->acdirmin;
1027 		ctx->acdirmax	= data->acdirmax;
1028 		ctx->need_mount	= false;
1029 
1030 		memcpy(sap, &data->addr, sizeof(data->addr));
1031 		ctx->nfs_server.addrlen = sizeof(data->addr);
1032 		ctx->nfs_server.port = ntohs(data->addr.sin_port);
1033 		if (sap->sa_family != AF_INET ||
1034 		    !nfs_verify_server_address(sap))
1035 			goto out_no_address;
1036 
1037 		if (!(data->flags & NFS_MOUNT_TCP))
1038 			ctx->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1039 		/* N.B. caller will free nfs_server.hostname in all cases */
1040 		ctx->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1041 		if (!ctx->nfs_server.hostname)
1042 			goto out_nomem;
1043 
1044 		ctx->namlen		= data->namlen;
1045 		ctx->bsize		= data->bsize;
1046 
1047 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
1048 			ctx->selected_flavor = data->pseudoflavor;
1049 		else
1050 			ctx->selected_flavor = RPC_AUTH_UNIX;
1051 
1052 		if (!(data->flags & NFS_MOUNT_NONLM))
1053 			ctx->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
1054 					 NFS_MOUNT_LOCAL_FCNTL);
1055 		else
1056 			ctx->flags |= (NFS_MOUNT_LOCAL_FLOCK|
1057 					NFS_MOUNT_LOCAL_FCNTL);
1058 
1059 		/*
1060 		 * The legacy version 6 binary mount data from userspace has a
1061 		 * field used only to transport selinux information into the
1062 		 * kernel.  To continue to support that functionality we
1063 		 * have a touch of selinux knowledge here in the NFS code. The
1064 		 * userspace code converted context=blah to just blah so we are
1065 		 * converting back to the full string selinux understands.
1066 		 */
1067 		if (data->context[0]){
1068 #ifdef CONFIG_SECURITY_SELINUX
1069 			int ret;
1070 
1071 			data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1072 			ret = vfs_parse_fs_string(fc, "context",
1073 						  data->context, strlen(data->context));
1074 			if (ret < 0)
1075 				return ret;
1076 #else
1077 			return -EINVAL;
1078 #endif
1079 		}
1080 
1081 		break;
1082 	default:
1083 		goto generic;
1084 	}
1085 
1086 	ret = nfs_validate_transport_protocol(fc, ctx);
1087 	if (ret)
1088 		return ret;
1089 
1090 	ctx->skip_reconfig_option_check = true;
1091 	return 0;
1092 
1093 generic:
1094 	return generic_parse_monolithic(fc, data);
1095 
1096 out_no_data:
1097 	if (is_remount_fc(fc)) {
1098 		ctx->skip_reconfig_option_check = true;
1099 		return 0;
1100 	}
1101 	return nfs_invalf(fc, "NFS: mount program didn't pass any mount data");
1102 
1103 out_no_v3:
1104 	return nfs_invalf(fc, "NFS: nfs_mount_data version does not support v3");
1105 
1106 out_no_sec:
1107 	return nfs_invalf(fc, "NFS: nfs_mount_data version supports only AUTH_SYS");
1108 
1109 out_nomem:
1110 	dfprintk(MOUNT, "NFS: not enough memory to handle mount options");
1111 	return -ENOMEM;
1112 
1113 out_no_address:
1114 	return nfs_invalf(fc, "NFS: mount program didn't pass remote address");
1115 
1116 out_invalid_fh:
1117 	return nfs_invalf(fc, "NFS: invalid root filehandle");
1118 
1119 out_invalid_data:
1120 	return nfs_invalf(fc, "NFS: invalid binary mount data");
1121 }
1122 
1123 #if IS_ENABLED(CONFIG_NFS_V4)
1124 struct compat_nfs_string {
1125 	compat_uint_t len;
1126 	compat_uptr_t data;
1127 };
1128 
compat_nfs_string(struct nfs_string * dst,struct compat_nfs_string * src)1129 static inline void compat_nfs_string(struct nfs_string *dst,
1130 				     struct compat_nfs_string *src)
1131 {
1132 	dst->data = compat_ptr(src->data);
1133 	dst->len = src->len;
1134 }
1135 
1136 struct compat_nfs4_mount_data_v1 {
1137 	compat_int_t version;
1138 	compat_int_t flags;
1139 	compat_int_t rsize;
1140 	compat_int_t wsize;
1141 	compat_int_t timeo;
1142 	compat_int_t retrans;
1143 	compat_int_t acregmin;
1144 	compat_int_t acregmax;
1145 	compat_int_t acdirmin;
1146 	compat_int_t acdirmax;
1147 	struct compat_nfs_string client_addr;
1148 	struct compat_nfs_string mnt_path;
1149 	struct compat_nfs_string hostname;
1150 	compat_uint_t host_addrlen;
1151 	compat_uptr_t host_addr;
1152 	compat_int_t proto;
1153 	compat_int_t auth_flavourlen;
1154 	compat_uptr_t auth_flavours;
1155 };
1156 
nfs4_compat_mount_data_conv(struct nfs4_mount_data * data)1157 static void nfs4_compat_mount_data_conv(struct nfs4_mount_data *data)
1158 {
1159 	struct compat_nfs4_mount_data_v1 *compat =
1160 			(struct compat_nfs4_mount_data_v1 *)data;
1161 
1162 	/* copy the fields backwards */
1163 	data->auth_flavours = compat_ptr(compat->auth_flavours);
1164 	data->auth_flavourlen = compat->auth_flavourlen;
1165 	data->proto = compat->proto;
1166 	data->host_addr = compat_ptr(compat->host_addr);
1167 	data->host_addrlen = compat->host_addrlen;
1168 	compat_nfs_string(&data->hostname, &compat->hostname);
1169 	compat_nfs_string(&data->mnt_path, &compat->mnt_path);
1170 	compat_nfs_string(&data->client_addr, &compat->client_addr);
1171 	data->acdirmax = compat->acdirmax;
1172 	data->acdirmin = compat->acdirmin;
1173 	data->acregmax = compat->acregmax;
1174 	data->acregmin = compat->acregmin;
1175 	data->retrans = compat->retrans;
1176 	data->timeo = compat->timeo;
1177 	data->wsize = compat->wsize;
1178 	data->rsize = compat->rsize;
1179 	data->flags = compat->flags;
1180 	data->version = compat->version;
1181 }
1182 
1183 /*
1184  * Validate NFSv4 mount options
1185  */
nfs4_parse_monolithic(struct fs_context * fc,struct nfs4_mount_data * data)1186 static int nfs4_parse_monolithic(struct fs_context *fc,
1187 				 struct nfs4_mount_data *data)
1188 {
1189 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
1190 	struct sockaddr *sap = (struct sockaddr *)&ctx->nfs_server.address;
1191 	int ret;
1192 	char *c;
1193 
1194 	if (!data) {
1195 		if (is_remount_fc(fc))
1196 			goto done;
1197 		return nfs_invalf(fc,
1198 			"NFS4: mount program didn't pass any mount data");
1199 	}
1200 
1201 	ctx->version = 4;
1202 
1203 	if (data->version != 1)
1204 		return generic_parse_monolithic(fc, data);
1205 
1206 	if (in_compat_syscall())
1207 		nfs4_compat_mount_data_conv(data);
1208 
1209 	if (data->host_addrlen > sizeof(ctx->nfs_server.address))
1210 		goto out_no_address;
1211 	if (data->host_addrlen == 0)
1212 		goto out_no_address;
1213 	ctx->nfs_server.addrlen = data->host_addrlen;
1214 	if (copy_from_user(sap, data->host_addr, data->host_addrlen))
1215 		return -EFAULT;
1216 	if (!nfs_verify_server_address(sap))
1217 		goto out_no_address;
1218 	ctx->nfs_server.port = ntohs(((struct sockaddr_in *)sap)->sin_port);
1219 
1220 	if (data->auth_flavourlen) {
1221 		rpc_authflavor_t pseudoflavor;
1222 
1223 		if (data->auth_flavourlen > 1)
1224 			goto out_inval_auth;
1225 		if (copy_from_user(&pseudoflavor, data->auth_flavours,
1226 				   sizeof(pseudoflavor)))
1227 			return -EFAULT;
1228 		ctx->selected_flavor = pseudoflavor;
1229 	} else {
1230 		ctx->selected_flavor = RPC_AUTH_UNIX;
1231 	}
1232 
1233 	c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
1234 	if (IS_ERR(c))
1235 		return PTR_ERR(c);
1236 	ctx->nfs_server.hostname = c;
1237 
1238 	c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
1239 	if (IS_ERR(c))
1240 		return PTR_ERR(c);
1241 	ctx->nfs_server.export_path = c;
1242 	dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
1243 
1244 	c = strndup_user(data->client_addr.data, 16);
1245 	if (IS_ERR(c))
1246 		return PTR_ERR(c);
1247 	ctx->client_address = c;
1248 
1249 	/*
1250 	 * Translate to nfs_fs_context, which nfs_fill_super
1251 	 * can deal with.
1252 	 */
1253 
1254 	ctx->flags	= data->flags & NFS4_MOUNT_FLAGMASK;
1255 	ctx->rsize	= data->rsize;
1256 	ctx->wsize	= data->wsize;
1257 	ctx->timeo	= data->timeo;
1258 	ctx->retrans	= data->retrans;
1259 	ctx->acregmin	= data->acregmin;
1260 	ctx->acregmax	= data->acregmax;
1261 	ctx->acdirmin	= data->acdirmin;
1262 	ctx->acdirmax	= data->acdirmax;
1263 	ctx->nfs_server.protocol = data->proto;
1264 	ret = nfs_validate_transport_protocol(fc, ctx);
1265 	if (ret)
1266 		return ret;
1267 done:
1268 	ctx->skip_reconfig_option_check = true;
1269 	return 0;
1270 
1271 out_inval_auth:
1272 	return nfs_invalf(fc, "NFS4: Invalid number of RPC auth flavours %d",
1273 		      data->auth_flavourlen);
1274 
1275 out_no_address:
1276 	return nfs_invalf(fc, "NFS4: mount program didn't pass remote address");
1277 }
1278 #endif
1279 
1280 /*
1281  * Parse a monolithic block of data from sys_mount().
1282  */
nfs_fs_context_parse_monolithic(struct fs_context * fc,void * data)1283 static int nfs_fs_context_parse_monolithic(struct fs_context *fc,
1284 					   void *data)
1285 {
1286 	if (fc->fs_type == &nfs_fs_type)
1287 		return nfs23_parse_monolithic(fc, data);
1288 
1289 #if IS_ENABLED(CONFIG_NFS_V4)
1290 	if (fc->fs_type == &nfs4_fs_type)
1291 		return nfs4_parse_monolithic(fc, data);
1292 #endif
1293 
1294 	return nfs_invalf(fc, "NFS: Unsupported monolithic data version");
1295 }
1296 
1297 /*
1298  * Validate the preparsed information in the config.
1299  */
nfs_fs_context_validate(struct fs_context * fc)1300 static int nfs_fs_context_validate(struct fs_context *fc)
1301 {
1302 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
1303 	struct nfs_subversion *nfs_mod;
1304 	struct sockaddr *sap = (struct sockaddr *)&ctx->nfs_server.address;
1305 	int max_namelen = PAGE_SIZE;
1306 	int max_pathlen = NFS_MAXPATHLEN;
1307 	int port = 0;
1308 	int ret;
1309 
1310 	if (!fc->source)
1311 		goto out_no_device_name;
1312 
1313 	/* Check for sanity first. */
1314 	if (ctx->minorversion && ctx->version != 4)
1315 		goto out_minorversion_mismatch;
1316 
1317 	if (ctx->options & NFS_OPTION_MIGRATION &&
1318 	    (ctx->version != 4 || ctx->minorversion != 0))
1319 		goto out_migration_misuse;
1320 
1321 	/* Verify that any proto=/mountproto= options match the address
1322 	 * families in the addr=/mountaddr= options.
1323 	 */
1324 	if (ctx->protofamily != AF_UNSPEC &&
1325 	    ctx->protofamily != ctx->nfs_server.address.sa_family)
1326 		goto out_proto_mismatch;
1327 
1328 	if (ctx->mountfamily != AF_UNSPEC) {
1329 		if (ctx->mount_server.addrlen) {
1330 			if (ctx->mountfamily != ctx->mount_server.address.sa_family)
1331 				goto out_mountproto_mismatch;
1332 		} else {
1333 			if (ctx->mountfamily != ctx->nfs_server.address.sa_family)
1334 				goto out_mountproto_mismatch;
1335 		}
1336 	}
1337 
1338 	if (!nfs_verify_server_address(sap))
1339 		goto out_no_address;
1340 
1341 	ret = nfs_validate_transport_protocol(fc, ctx);
1342 	if (ret)
1343 		return ret;
1344 
1345 	if (ctx->version == 4) {
1346 		if (IS_ENABLED(CONFIG_NFS_V4)) {
1347 			if (ctx->nfs_server.protocol == XPRT_TRANSPORT_RDMA)
1348 				port = NFS_RDMA_PORT;
1349 			else
1350 				port = NFS_PORT;
1351 			max_namelen = NFS4_MAXNAMLEN;
1352 			max_pathlen = NFS4_MAXPATHLEN;
1353 			ctx->flags &= ~(NFS_MOUNT_NONLM | NFS_MOUNT_NOACL |
1354 					NFS_MOUNT_VER3 | NFS_MOUNT_LOCAL_FLOCK |
1355 					NFS_MOUNT_LOCAL_FCNTL);
1356 		} else {
1357 			goto out_v4_not_compiled;
1358 		}
1359 	} else {
1360 		nfs_set_mount_transport_protocol(ctx);
1361 		if (ctx->nfs_server.protocol == XPRT_TRANSPORT_RDMA)
1362 			port = NFS_RDMA_PORT;
1363 	}
1364 
1365 	nfs_set_port(sap, &ctx->nfs_server.port, port);
1366 
1367 	ret = nfs_parse_source(fc, max_namelen, max_pathlen);
1368 	if (ret < 0)
1369 		return ret;
1370 
1371 	/* Load the NFS protocol module if we haven't done so yet */
1372 	if (!ctx->nfs_mod) {
1373 		nfs_mod = get_nfs_version(ctx->version);
1374 		if (IS_ERR(nfs_mod)) {
1375 			ret = PTR_ERR(nfs_mod);
1376 			goto out_version_unavailable;
1377 		}
1378 		ctx->nfs_mod = nfs_mod;
1379 	}
1380 
1381 	/* Ensure the filesystem context has the correct fs_type */
1382 	if (fc->fs_type != ctx->nfs_mod->nfs_fs) {
1383 		module_put(fc->fs_type->owner);
1384 		__module_get(ctx->nfs_mod->nfs_fs->owner);
1385 		fc->fs_type = ctx->nfs_mod->nfs_fs;
1386 	}
1387 	return 0;
1388 
1389 out_no_device_name:
1390 	return nfs_invalf(fc, "NFS: Device name not specified");
1391 out_v4_not_compiled:
1392 	nfs_errorf(fc, "NFS: NFSv4 is not compiled into kernel");
1393 	return -EPROTONOSUPPORT;
1394 out_no_address:
1395 	return nfs_invalf(fc, "NFS: mount program didn't pass remote address");
1396 out_mountproto_mismatch:
1397 	return nfs_invalf(fc, "NFS: Mount server address does not match mountproto= option");
1398 out_proto_mismatch:
1399 	return nfs_invalf(fc, "NFS: Server address does not match proto= option");
1400 out_minorversion_mismatch:
1401 	return nfs_invalf(fc, "NFS: Mount option vers=%u does not support minorversion=%u",
1402 			  ctx->version, ctx->minorversion);
1403 out_migration_misuse:
1404 	return nfs_invalf(fc, "NFS: 'Migration' not supported for this NFS version");
1405 out_version_unavailable:
1406 	nfs_errorf(fc, "NFS: Version unavailable");
1407 	return ret;
1408 }
1409 
1410 /*
1411  * Create an NFS superblock by the appropriate method.
1412  */
nfs_get_tree(struct fs_context * fc)1413 static int nfs_get_tree(struct fs_context *fc)
1414 {
1415 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
1416 	int err = nfs_fs_context_validate(fc);
1417 
1418 	if (err)
1419 		return err;
1420 	if (!ctx->internal)
1421 		return ctx->nfs_mod->rpc_ops->try_get_tree(fc);
1422 	else
1423 		return nfs_get_tree_common(fc);
1424 }
1425 
1426 /*
1427  * Handle duplication of a configuration.  The caller copied *src into *sc, but
1428  * it can't deal with resource pointers in the filesystem context, so we have
1429  * to do that.  We need to clear pointers, copy data or get extra refs as
1430  * appropriate.
1431  */
nfs_fs_context_dup(struct fs_context * fc,struct fs_context * src_fc)1432 static int nfs_fs_context_dup(struct fs_context *fc, struct fs_context *src_fc)
1433 {
1434 	struct nfs_fs_context *src = nfs_fc2context(src_fc), *ctx;
1435 
1436 	ctx = kmemdup(src, sizeof(struct nfs_fs_context), GFP_KERNEL);
1437 	if (!ctx)
1438 		return -ENOMEM;
1439 
1440 	ctx->mntfh = nfs_alloc_fhandle();
1441 	if (!ctx->mntfh) {
1442 		kfree(ctx);
1443 		return -ENOMEM;
1444 	}
1445 	nfs_copy_fh(ctx->mntfh, src->mntfh);
1446 
1447 	__module_get(ctx->nfs_mod->owner);
1448 	ctx->client_address		= NULL;
1449 	ctx->mount_server.hostname	= NULL;
1450 	ctx->nfs_server.export_path	= NULL;
1451 	ctx->nfs_server.hostname	= NULL;
1452 	ctx->fscache_uniq		= NULL;
1453 	ctx->clone_data.fattr		= NULL;
1454 	fc->fs_private = ctx;
1455 	return 0;
1456 }
1457 
nfs_fs_context_free(struct fs_context * fc)1458 static void nfs_fs_context_free(struct fs_context *fc)
1459 {
1460 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
1461 
1462 	if (ctx) {
1463 		if (ctx->server)
1464 			nfs_free_server(ctx->server);
1465 		if (ctx->nfs_mod)
1466 			put_nfs_version(ctx->nfs_mod);
1467 		kfree(ctx->client_address);
1468 		kfree(ctx->mount_server.hostname);
1469 		kfree(ctx->nfs_server.export_path);
1470 		kfree(ctx->nfs_server.hostname);
1471 		kfree(ctx->fscache_uniq);
1472 		nfs_free_fhandle(ctx->mntfh);
1473 		nfs_free_fattr(ctx->clone_data.fattr);
1474 		kfree(ctx);
1475 	}
1476 }
1477 
1478 static const struct fs_context_operations nfs_fs_context_ops = {
1479 	.free			= nfs_fs_context_free,
1480 	.dup			= nfs_fs_context_dup,
1481 	.parse_param		= nfs_fs_context_parse_param,
1482 	.parse_monolithic	= nfs_fs_context_parse_monolithic,
1483 	.get_tree		= nfs_get_tree,
1484 	.reconfigure		= nfs_reconfigure,
1485 };
1486 
1487 /*
1488  * Prepare superblock configuration.  We use the namespaces attached to the
1489  * context.  This may be the current process's namespaces, or it may be a
1490  * container's namespaces.
1491  */
nfs_init_fs_context(struct fs_context * fc)1492 static int nfs_init_fs_context(struct fs_context *fc)
1493 {
1494 	struct nfs_fs_context *ctx;
1495 
1496 	ctx = kzalloc(sizeof(struct nfs_fs_context), GFP_KERNEL);
1497 	if (unlikely(!ctx))
1498 		return -ENOMEM;
1499 
1500 	ctx->mntfh = nfs_alloc_fhandle();
1501 	if (unlikely(!ctx->mntfh)) {
1502 		kfree(ctx);
1503 		return -ENOMEM;
1504 	}
1505 
1506 	ctx->protofamily	= AF_UNSPEC;
1507 	ctx->mountfamily	= AF_UNSPEC;
1508 	ctx->mount_server.port	= NFS_UNSPEC_PORT;
1509 
1510 	if (fc->root) {
1511 		/* reconfigure, start with the current config */
1512 		struct nfs_server *nfss = fc->root->d_sb->s_fs_info;
1513 		struct net *net = nfss->nfs_client->cl_net;
1514 
1515 		ctx->flags		= nfss->flags;
1516 		ctx->rsize		= nfss->rsize;
1517 		ctx->wsize		= nfss->wsize;
1518 		ctx->retrans		= nfss->client->cl_timeout->to_retries;
1519 		ctx->selected_flavor	= nfss->client->cl_auth->au_flavor;
1520 		ctx->acregmin		= nfss->acregmin / HZ;
1521 		ctx->acregmax		= nfss->acregmax / HZ;
1522 		ctx->acdirmin		= nfss->acdirmin / HZ;
1523 		ctx->acdirmax		= nfss->acdirmax / HZ;
1524 		ctx->timeo		= 10U * nfss->client->cl_timeout->to_initval / HZ;
1525 		ctx->nfs_server.port	= nfss->port;
1526 		ctx->nfs_server.addrlen	= nfss->nfs_client->cl_addrlen;
1527 		ctx->version		= nfss->nfs_client->rpc_ops->version;
1528 		ctx->minorversion	= nfss->nfs_client->cl_minorversion;
1529 
1530 		memcpy(&ctx->nfs_server.address, &nfss->nfs_client->cl_addr,
1531 			ctx->nfs_server.addrlen);
1532 
1533 		if (fc->net_ns != net) {
1534 			put_net(fc->net_ns);
1535 			fc->net_ns = get_net(net);
1536 		}
1537 
1538 		ctx->nfs_mod = nfss->nfs_client->cl_nfs_mod;
1539 		__module_get(ctx->nfs_mod->owner);
1540 	} else {
1541 		/* defaults */
1542 		ctx->timeo		= NFS_UNSPEC_TIMEO;
1543 		ctx->retrans		= NFS_UNSPEC_RETRANS;
1544 		ctx->acregmin		= NFS_DEF_ACREGMIN;
1545 		ctx->acregmax		= NFS_DEF_ACREGMAX;
1546 		ctx->acdirmin		= NFS_DEF_ACDIRMIN;
1547 		ctx->acdirmax		= NFS_DEF_ACDIRMAX;
1548 		ctx->nfs_server.port	= NFS_UNSPEC_PORT;
1549 		ctx->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1550 		ctx->selected_flavor	= RPC_AUTH_MAXFLAVOR;
1551 		ctx->minorversion	= 0;
1552 		ctx->need_mount		= true;
1553 
1554 		fc->s_iflags		|= SB_I_STABLE_WRITES;
1555 	}
1556 	fc->fs_private = ctx;
1557 	fc->ops = &nfs_fs_context_ops;
1558 	return 0;
1559 }
1560 
1561 struct file_system_type nfs_fs_type = {
1562 	.owner			= THIS_MODULE,
1563 	.name			= "nfs",
1564 	.init_fs_context	= nfs_init_fs_context,
1565 	.parameters		= nfs_fs_parameters,
1566 	.kill_sb		= nfs_kill_super,
1567 	.fs_flags		= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
1568 };
1569 MODULE_ALIAS_FS("nfs");
1570 EXPORT_SYMBOL_GPL(nfs_fs_type);
1571 
1572 #if IS_ENABLED(CONFIG_NFS_V4)
1573 struct file_system_type nfs4_fs_type = {
1574 	.owner			= THIS_MODULE,
1575 	.name			= "nfs4",
1576 	.init_fs_context	= nfs_init_fs_context,
1577 	.parameters		= nfs_fs_parameters,
1578 	.kill_sb		= nfs_kill_super,
1579 	.fs_flags		= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
1580 };
1581 MODULE_ALIAS_FS("nfs4");
1582 MODULE_ALIAS("nfs4");
1583 EXPORT_SYMBOL_GPL(nfs4_fs_type);
1584 #endif /* CONFIG_NFS_V4 */
1585