xref: /linux/fs/nfs/fs_context.c (revision e80a48bade619ec5a92230b3d4ae84bfc2746822)
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/compat.h>
14 #include <linux/module.h>
15 #include <linux/fs.h>
16 #include <linux/fs_context.h>
17 #include <linux/fs_parser.h>
18 #include <linux/nfs_fs.h>
19 #include <linux/nfs_mount.h>
20 #include <linux/nfs4_mount.h>
21 #include "nfs.h"
22 #include "internal.h"
23 
24 #include "nfstrace.h"
25 
26 #define NFSDBG_FACILITY		NFSDBG_MOUNT
27 
28 #if IS_ENABLED(CONFIG_NFS_V3)
29 #define NFS_DEFAULT_VERSION 3
30 #else
31 #define NFS_DEFAULT_VERSION 2
32 #endif
33 
34 #define NFS_MAX_CONNECTIONS 16
35 
36 enum nfs_param {
37 	Opt_ac,
38 	Opt_acdirmax,
39 	Opt_acdirmin,
40 	Opt_acl,
41 	Opt_acregmax,
42 	Opt_acregmin,
43 	Opt_actimeo,
44 	Opt_addr,
45 	Opt_bg,
46 	Opt_bsize,
47 	Opt_clientaddr,
48 	Opt_cto,
49 	Opt_fg,
50 	Opt_fscache,
51 	Opt_fscache_flag,
52 	Opt_hard,
53 	Opt_intr,
54 	Opt_local_lock,
55 	Opt_lock,
56 	Opt_lookupcache,
57 	Opt_migration,
58 	Opt_minorversion,
59 	Opt_mountaddr,
60 	Opt_mounthost,
61 	Opt_mountport,
62 	Opt_mountproto,
63 	Opt_mountvers,
64 	Opt_namelen,
65 	Opt_nconnect,
66 	Opt_max_connect,
67 	Opt_port,
68 	Opt_posix,
69 	Opt_proto,
70 	Opt_rdirplus,
71 	Opt_rdma,
72 	Opt_resvport,
73 	Opt_retrans,
74 	Opt_retry,
75 	Opt_rsize,
76 	Opt_sec,
77 	Opt_sharecache,
78 	Opt_sloppy,
79 	Opt_soft,
80 	Opt_softerr,
81 	Opt_softreval,
82 	Opt_source,
83 	Opt_tcp,
84 	Opt_timeo,
85 	Opt_trunkdiscovery,
86 	Opt_udp,
87 	Opt_v,
88 	Opt_vers,
89 	Opt_wsize,
90 	Opt_write,
91 };
92 
93 enum {
94 	Opt_local_lock_all,
95 	Opt_local_lock_flock,
96 	Opt_local_lock_none,
97 	Opt_local_lock_posix,
98 };
99 
100 static const struct constant_table nfs_param_enums_local_lock[] = {
101 	{ "all",		Opt_local_lock_all },
102 	{ "flock",	Opt_local_lock_flock },
103 	{ "posix",	Opt_local_lock_posix },
104 	{ "none",		Opt_local_lock_none },
105 	{}
106 };
107 
108 enum {
109 	Opt_lookupcache_all,
110 	Opt_lookupcache_none,
111 	Opt_lookupcache_positive,
112 };
113 
114 static const struct constant_table nfs_param_enums_lookupcache[] = {
115 	{ "all",		Opt_lookupcache_all },
116 	{ "none",		Opt_lookupcache_none },
117 	{ "pos",		Opt_lookupcache_positive },
118 	{ "positive",		Opt_lookupcache_positive },
119 	{}
120 };
121 
122 enum {
123 	Opt_write_lazy,
124 	Opt_write_eager,
125 	Opt_write_wait,
126 };
127 
128 static const struct constant_table nfs_param_enums_write[] = {
129 	{ "lazy",		Opt_write_lazy },
130 	{ "eager",		Opt_write_eager },
131 	{ "wait",		Opt_write_wait },
132 	{}
133 };
134 
135 static const struct fs_parameter_spec nfs_fs_parameters[] = {
136 	fsparam_flag_no("ac",		Opt_ac),
137 	fsparam_u32   ("acdirmax",	Opt_acdirmax),
138 	fsparam_u32   ("acdirmin",	Opt_acdirmin),
139 	fsparam_flag_no("acl",		Opt_acl),
140 	fsparam_u32   ("acregmax",	Opt_acregmax),
141 	fsparam_u32   ("acregmin",	Opt_acregmin),
142 	fsparam_u32   ("actimeo",	Opt_actimeo),
143 	fsparam_string("addr",		Opt_addr),
144 	fsparam_flag  ("bg",		Opt_bg),
145 	fsparam_u32   ("bsize",		Opt_bsize),
146 	fsparam_string("clientaddr",	Opt_clientaddr),
147 	fsparam_flag_no("cto",		Opt_cto),
148 	fsparam_flag  ("fg",		Opt_fg),
149 	fsparam_flag_no("fsc",		Opt_fscache_flag),
150 	fsparam_string("fsc",		Opt_fscache),
151 	fsparam_flag  ("hard",		Opt_hard),
152 	__fsparam(NULL, "intr",		Opt_intr,
153 		  fs_param_neg_with_no|fs_param_deprecated, NULL),
154 	fsparam_enum  ("local_lock",	Opt_local_lock, nfs_param_enums_local_lock),
155 	fsparam_flag_no("lock",		Opt_lock),
156 	fsparam_enum  ("lookupcache",	Opt_lookupcache, nfs_param_enums_lookupcache),
157 	fsparam_flag_no("migration",	Opt_migration),
158 	fsparam_u32   ("minorversion",	Opt_minorversion),
159 	fsparam_string("mountaddr",	Opt_mountaddr),
160 	fsparam_string("mounthost",	Opt_mounthost),
161 	fsparam_u32   ("mountport",	Opt_mountport),
162 	fsparam_string("mountproto",	Opt_mountproto),
163 	fsparam_u32   ("mountvers",	Opt_mountvers),
164 	fsparam_u32   ("namlen",	Opt_namelen),
165 	fsparam_u32   ("nconnect",	Opt_nconnect),
166 	fsparam_u32   ("max_connect",	Opt_max_connect),
167 	fsparam_string("nfsvers",	Opt_vers),
168 	fsparam_u32   ("port",		Opt_port),
169 	fsparam_flag_no("posix",	Opt_posix),
170 	fsparam_string("proto",		Opt_proto),
171 	fsparam_flag_no("rdirplus",	Opt_rdirplus),
172 	fsparam_flag  ("rdma",		Opt_rdma),
173 	fsparam_flag_no("resvport",	Opt_resvport),
174 	fsparam_u32   ("retrans",	Opt_retrans),
175 	fsparam_string("retry",		Opt_retry),
176 	fsparam_u32   ("rsize",		Opt_rsize),
177 	fsparam_string("sec",		Opt_sec),
178 	fsparam_flag_no("sharecache",	Opt_sharecache),
179 	fsparam_flag  ("sloppy",	Opt_sloppy),
180 	fsparam_flag  ("soft",		Opt_soft),
181 	fsparam_flag  ("softerr",	Opt_softerr),
182 	fsparam_flag  ("softreval",	Opt_softreval),
183 	fsparam_string("source",	Opt_source),
184 	fsparam_flag  ("tcp",		Opt_tcp),
185 	fsparam_u32   ("timeo",		Opt_timeo),
186 	fsparam_flag_no("trunkdiscovery", Opt_trunkdiscovery),
187 	fsparam_flag  ("udp",		Opt_udp),
188 	fsparam_flag  ("v2",		Opt_v),
189 	fsparam_flag  ("v3",		Opt_v),
190 	fsparam_flag  ("v4",		Opt_v),
191 	fsparam_flag  ("v4.0",		Opt_v),
192 	fsparam_flag  ("v4.1",		Opt_v),
193 	fsparam_flag  ("v4.2",		Opt_v),
194 	fsparam_string("vers",		Opt_vers),
195 	fsparam_enum  ("write",		Opt_write, nfs_param_enums_write),
196 	fsparam_u32   ("wsize",		Opt_wsize),
197 	{}
198 };
199 
200 enum {
201 	Opt_vers_2,
202 	Opt_vers_3,
203 	Opt_vers_4,
204 	Opt_vers_4_0,
205 	Opt_vers_4_1,
206 	Opt_vers_4_2,
207 };
208 
209 static const struct constant_table nfs_vers_tokens[] = {
210 	{ "2",		Opt_vers_2 },
211 	{ "3",		Opt_vers_3 },
212 	{ "4",		Opt_vers_4 },
213 	{ "4.0",	Opt_vers_4_0 },
214 	{ "4.1",	Opt_vers_4_1 },
215 	{ "4.2",	Opt_vers_4_2 },
216 	{}
217 };
218 
219 enum {
220 	Opt_xprt_rdma,
221 	Opt_xprt_rdma6,
222 	Opt_xprt_tcp,
223 	Opt_xprt_tcp6,
224 	Opt_xprt_udp,
225 	Opt_xprt_udp6,
226 	nr__Opt_xprt
227 };
228 
229 static const struct constant_table nfs_xprt_protocol_tokens[] = {
230 	{ "rdma",	Opt_xprt_rdma },
231 	{ "rdma6",	Opt_xprt_rdma6 },
232 	{ "tcp",	Opt_xprt_tcp },
233 	{ "tcp6",	Opt_xprt_tcp6 },
234 	{ "udp",	Opt_xprt_udp },
235 	{ "udp6",	Opt_xprt_udp6 },
236 	{}
237 };
238 
239 enum {
240 	Opt_sec_krb5,
241 	Opt_sec_krb5i,
242 	Opt_sec_krb5p,
243 	Opt_sec_lkey,
244 	Opt_sec_lkeyi,
245 	Opt_sec_lkeyp,
246 	Opt_sec_none,
247 	Opt_sec_spkm,
248 	Opt_sec_spkmi,
249 	Opt_sec_spkmp,
250 	Opt_sec_sys,
251 	nr__Opt_sec
252 };
253 
254 static const struct constant_table nfs_secflavor_tokens[] = {
255 	{ "krb5",	Opt_sec_krb5 },
256 	{ "krb5i",	Opt_sec_krb5i },
257 	{ "krb5p",	Opt_sec_krb5p },
258 	{ "lkey",	Opt_sec_lkey },
259 	{ "lkeyi",	Opt_sec_lkeyi },
260 	{ "lkeyp",	Opt_sec_lkeyp },
261 	{ "none",	Opt_sec_none },
262 	{ "null",	Opt_sec_none },
263 	{ "spkm3",	Opt_sec_spkm },
264 	{ "spkm3i",	Opt_sec_spkmi },
265 	{ "spkm3p",	Opt_sec_spkmp },
266 	{ "sys",	Opt_sec_sys },
267 	{}
268 };
269 
270 /*
271  * Sanity-check a server address provided by the mount command.
272  *
273  * Address family must be initialized, and address must not be
274  * the ANY address for that family.
275  */
276 static int nfs_verify_server_address(struct sockaddr_storage *addr)
277 {
278 	switch (addr->ss_family) {
279 	case AF_INET: {
280 		struct sockaddr_in *sa = (struct sockaddr_in *)addr;
281 		return sa->sin_addr.s_addr != htonl(INADDR_ANY);
282 	}
283 	case AF_INET6: {
284 		struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
285 		return !ipv6_addr_any(sa);
286 	}
287 	}
288 
289 	return 0;
290 }
291 
292 #ifdef CONFIG_NFS_DISABLE_UDP_SUPPORT
293 static bool nfs_server_transport_udp_invalid(const struct nfs_fs_context *ctx)
294 {
295 	return true;
296 }
297 #else
298 static bool nfs_server_transport_udp_invalid(const struct nfs_fs_context *ctx)
299 {
300 	if (ctx->version == 4)
301 		return true;
302 	return false;
303 }
304 #endif
305 
306 /*
307  * Sanity check the NFS transport protocol.
308  */
309 static int nfs_validate_transport_protocol(struct fs_context *fc,
310 					   struct nfs_fs_context *ctx)
311 {
312 	switch (ctx->nfs_server.protocol) {
313 	case XPRT_TRANSPORT_UDP:
314 		if (nfs_server_transport_udp_invalid(ctx))
315 			goto out_invalid_transport_udp;
316 		break;
317 	case XPRT_TRANSPORT_TCP:
318 	case XPRT_TRANSPORT_RDMA:
319 		break;
320 	default:
321 		ctx->nfs_server.protocol = XPRT_TRANSPORT_TCP;
322 	}
323 	return 0;
324 out_invalid_transport_udp:
325 	return nfs_invalf(fc, "NFS: Unsupported transport protocol udp");
326 }
327 
328 /*
329  * For text based NFSv2/v3 mounts, the mount protocol transport default
330  * settings should depend upon the specified NFS transport.
331  */
332 static void nfs_set_mount_transport_protocol(struct nfs_fs_context *ctx)
333 {
334 	if (ctx->mount_server.protocol == XPRT_TRANSPORT_UDP ||
335 	    ctx->mount_server.protocol == XPRT_TRANSPORT_TCP)
336 			return;
337 	switch (ctx->nfs_server.protocol) {
338 	case XPRT_TRANSPORT_UDP:
339 		ctx->mount_server.protocol = XPRT_TRANSPORT_UDP;
340 		break;
341 	case XPRT_TRANSPORT_TCP:
342 	case XPRT_TRANSPORT_RDMA:
343 		ctx->mount_server.protocol = XPRT_TRANSPORT_TCP;
344 	}
345 }
346 
347 /*
348  * Add 'flavor' to 'auth_info' if not already present.
349  * Returns true if 'flavor' ends up in the list, false otherwise
350  */
351 static int nfs_auth_info_add(struct fs_context *fc,
352 			     struct nfs_auth_info *auth_info,
353 			     rpc_authflavor_t flavor)
354 {
355 	unsigned int i;
356 	unsigned int max_flavor_len = ARRAY_SIZE(auth_info->flavors);
357 
358 	/* make sure this flavor isn't already in the list */
359 	for (i = 0; i < auth_info->flavor_len; i++) {
360 		if (flavor == auth_info->flavors[i])
361 			return 0;
362 	}
363 
364 	if (auth_info->flavor_len + 1 >= max_flavor_len)
365 		return nfs_invalf(fc, "NFS: too many sec= flavors");
366 
367 	auth_info->flavors[auth_info->flavor_len++] = flavor;
368 	return 0;
369 }
370 
371 /*
372  * Parse the value of the 'sec=' option.
373  */
374 static int nfs_parse_security_flavors(struct fs_context *fc,
375 				      struct fs_parameter *param)
376 {
377 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
378 	rpc_authflavor_t pseudoflavor;
379 	char *string = param->string, *p;
380 	int ret;
381 
382 	trace_nfs_mount_assign(param->key, string);
383 
384 	while ((p = strsep(&string, ":")) != NULL) {
385 		if (!*p)
386 			continue;
387 		switch (lookup_constant(nfs_secflavor_tokens, p, -1)) {
388 		case Opt_sec_none:
389 			pseudoflavor = RPC_AUTH_NULL;
390 			break;
391 		case Opt_sec_sys:
392 			pseudoflavor = RPC_AUTH_UNIX;
393 			break;
394 		case Opt_sec_krb5:
395 			pseudoflavor = RPC_AUTH_GSS_KRB5;
396 			break;
397 		case Opt_sec_krb5i:
398 			pseudoflavor = RPC_AUTH_GSS_KRB5I;
399 			break;
400 		case Opt_sec_krb5p:
401 			pseudoflavor = RPC_AUTH_GSS_KRB5P;
402 			break;
403 		case Opt_sec_lkey:
404 			pseudoflavor = RPC_AUTH_GSS_LKEY;
405 			break;
406 		case Opt_sec_lkeyi:
407 			pseudoflavor = RPC_AUTH_GSS_LKEYI;
408 			break;
409 		case Opt_sec_lkeyp:
410 			pseudoflavor = RPC_AUTH_GSS_LKEYP;
411 			break;
412 		case Opt_sec_spkm:
413 			pseudoflavor = RPC_AUTH_GSS_SPKM;
414 			break;
415 		case Opt_sec_spkmi:
416 			pseudoflavor = RPC_AUTH_GSS_SPKMI;
417 			break;
418 		case Opt_sec_spkmp:
419 			pseudoflavor = RPC_AUTH_GSS_SPKMP;
420 			break;
421 		default:
422 			return nfs_invalf(fc, "NFS: sec=%s option not recognized", p);
423 		}
424 
425 		ret = nfs_auth_info_add(fc, &ctx->auth_info, pseudoflavor);
426 		if (ret < 0)
427 			return ret;
428 	}
429 
430 	return 0;
431 }
432 
433 static int nfs_parse_version_string(struct fs_context *fc,
434 				    const char *string)
435 {
436 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
437 
438 	ctx->flags &= ~NFS_MOUNT_VER3;
439 	switch (lookup_constant(nfs_vers_tokens, string, -1)) {
440 	case Opt_vers_2:
441 		ctx->version = 2;
442 		break;
443 	case Opt_vers_3:
444 		ctx->flags |= NFS_MOUNT_VER3;
445 		ctx->version = 3;
446 		break;
447 	case Opt_vers_4:
448 		/* Backward compatibility option. In future,
449 		 * the mount program should always supply
450 		 * a NFSv4 minor version number.
451 		 */
452 		ctx->version = 4;
453 		break;
454 	case Opt_vers_4_0:
455 		ctx->version = 4;
456 		ctx->minorversion = 0;
457 		break;
458 	case Opt_vers_4_1:
459 		ctx->version = 4;
460 		ctx->minorversion = 1;
461 		break;
462 	case Opt_vers_4_2:
463 		ctx->version = 4;
464 		ctx->minorversion = 2;
465 		break;
466 	default:
467 		return nfs_invalf(fc, "NFS: Unsupported NFS version");
468 	}
469 	return 0;
470 }
471 
472 /*
473  * Parse a single mount parameter.
474  */
475 static int nfs_fs_context_parse_param(struct fs_context *fc,
476 				      struct fs_parameter *param)
477 {
478 	struct fs_parse_result result;
479 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
480 	unsigned short protofamily, mountfamily;
481 	unsigned int len;
482 	int ret, opt;
483 
484 	trace_nfs_mount_option(param);
485 
486 	opt = fs_parse(fc, nfs_fs_parameters, param, &result);
487 	if (opt < 0)
488 		return (opt == -ENOPARAM && ctx->sloppy) ? 1 : opt;
489 
490 	if (fc->security)
491 		ctx->has_sec_mnt_opts = 1;
492 
493 	switch (opt) {
494 	case Opt_source:
495 		if (fc->source)
496 			return nfs_invalf(fc, "NFS: Multiple sources not supported");
497 		fc->source = param->string;
498 		param->string = NULL;
499 		break;
500 
501 		/*
502 		 * boolean options:  foo/nofoo
503 		 */
504 	case Opt_soft:
505 		ctx->flags |= NFS_MOUNT_SOFT;
506 		ctx->flags &= ~NFS_MOUNT_SOFTERR;
507 		break;
508 	case Opt_softerr:
509 		ctx->flags |= NFS_MOUNT_SOFTERR | NFS_MOUNT_SOFTREVAL;
510 		ctx->flags &= ~NFS_MOUNT_SOFT;
511 		break;
512 	case Opt_hard:
513 		ctx->flags &= ~(NFS_MOUNT_SOFT |
514 				NFS_MOUNT_SOFTERR |
515 				NFS_MOUNT_SOFTREVAL);
516 		break;
517 	case Opt_softreval:
518 		if (result.negated)
519 			ctx->flags &= ~NFS_MOUNT_SOFTREVAL;
520 		else
521 			ctx->flags |= NFS_MOUNT_SOFTREVAL;
522 		break;
523 	case Opt_posix:
524 		if (result.negated)
525 			ctx->flags &= ~NFS_MOUNT_POSIX;
526 		else
527 			ctx->flags |= NFS_MOUNT_POSIX;
528 		break;
529 	case Opt_cto:
530 		if (result.negated)
531 			ctx->flags |= NFS_MOUNT_NOCTO;
532 		else
533 			ctx->flags &= ~NFS_MOUNT_NOCTO;
534 		break;
535 	case Opt_trunkdiscovery:
536 		if (result.negated)
537 			ctx->flags &= ~NFS_MOUNT_TRUNK_DISCOVERY;
538 		else
539 			ctx->flags |= NFS_MOUNT_TRUNK_DISCOVERY;
540 		break;
541 	case Opt_ac:
542 		if (result.negated)
543 			ctx->flags |= NFS_MOUNT_NOAC;
544 		else
545 			ctx->flags &= ~NFS_MOUNT_NOAC;
546 		break;
547 	case Opt_lock:
548 		if (result.negated) {
549 			ctx->flags |= NFS_MOUNT_NONLM;
550 			ctx->flags |= (NFS_MOUNT_LOCAL_FLOCK | NFS_MOUNT_LOCAL_FCNTL);
551 		} else {
552 			ctx->flags &= ~NFS_MOUNT_NONLM;
553 			ctx->flags &= ~(NFS_MOUNT_LOCAL_FLOCK | NFS_MOUNT_LOCAL_FCNTL);
554 		}
555 		break;
556 	case Opt_udp:
557 		ctx->flags &= ~NFS_MOUNT_TCP;
558 		ctx->nfs_server.protocol = XPRT_TRANSPORT_UDP;
559 		break;
560 	case Opt_tcp:
561 	case Opt_rdma:
562 		ctx->flags |= NFS_MOUNT_TCP; /* for side protocols */
563 		ret = xprt_find_transport_ident(param->key);
564 		if (ret < 0)
565 			goto out_bad_transport;
566 		ctx->nfs_server.protocol = ret;
567 		break;
568 	case Opt_acl:
569 		if (result.negated)
570 			ctx->flags |= NFS_MOUNT_NOACL;
571 		else
572 			ctx->flags &= ~NFS_MOUNT_NOACL;
573 		break;
574 	case Opt_rdirplus:
575 		if (result.negated)
576 			ctx->flags |= NFS_MOUNT_NORDIRPLUS;
577 		else
578 			ctx->flags &= ~NFS_MOUNT_NORDIRPLUS;
579 		break;
580 	case Opt_sharecache:
581 		if (result.negated)
582 			ctx->flags |= NFS_MOUNT_UNSHARED;
583 		else
584 			ctx->flags &= ~NFS_MOUNT_UNSHARED;
585 		break;
586 	case Opt_resvport:
587 		if (result.negated)
588 			ctx->flags |= NFS_MOUNT_NORESVPORT;
589 		else
590 			ctx->flags &= ~NFS_MOUNT_NORESVPORT;
591 		break;
592 	case Opt_fscache_flag:
593 		if (result.negated)
594 			ctx->options &= ~NFS_OPTION_FSCACHE;
595 		else
596 			ctx->options |= NFS_OPTION_FSCACHE;
597 		kfree(ctx->fscache_uniq);
598 		ctx->fscache_uniq = NULL;
599 		break;
600 	case Opt_fscache:
601 		ctx->options |= NFS_OPTION_FSCACHE;
602 		kfree(ctx->fscache_uniq);
603 		ctx->fscache_uniq = param->string;
604 		param->string = NULL;
605 		break;
606 	case Opt_migration:
607 		if (result.negated)
608 			ctx->options &= ~NFS_OPTION_MIGRATION;
609 		else
610 			ctx->options |= NFS_OPTION_MIGRATION;
611 		break;
612 
613 		/*
614 		 * options that take numeric values
615 		 */
616 	case Opt_port:
617 		if (result.uint_32 > USHRT_MAX)
618 			goto out_of_bounds;
619 		ctx->nfs_server.port = result.uint_32;
620 		break;
621 	case Opt_rsize:
622 		ctx->rsize = result.uint_32;
623 		break;
624 	case Opt_wsize:
625 		ctx->wsize = result.uint_32;
626 		break;
627 	case Opt_bsize:
628 		ctx->bsize = result.uint_32;
629 		break;
630 	case Opt_timeo:
631 		if (result.uint_32 < 1 || result.uint_32 > INT_MAX)
632 			goto out_of_bounds;
633 		ctx->timeo = result.uint_32;
634 		break;
635 	case Opt_retrans:
636 		if (result.uint_32 > INT_MAX)
637 			goto out_of_bounds;
638 		ctx->retrans = result.uint_32;
639 		break;
640 	case Opt_acregmin:
641 		ctx->acregmin = result.uint_32;
642 		break;
643 	case Opt_acregmax:
644 		ctx->acregmax = result.uint_32;
645 		break;
646 	case Opt_acdirmin:
647 		ctx->acdirmin = result.uint_32;
648 		break;
649 	case Opt_acdirmax:
650 		ctx->acdirmax = result.uint_32;
651 		break;
652 	case Opt_actimeo:
653 		ctx->acregmin = result.uint_32;
654 		ctx->acregmax = result.uint_32;
655 		ctx->acdirmin = result.uint_32;
656 		ctx->acdirmax = result.uint_32;
657 		break;
658 	case Opt_namelen:
659 		ctx->namlen = result.uint_32;
660 		break;
661 	case Opt_mountport:
662 		if (result.uint_32 > USHRT_MAX)
663 			goto out_of_bounds;
664 		ctx->mount_server.port = result.uint_32;
665 		break;
666 	case Opt_mountvers:
667 		if (result.uint_32 < NFS_MNT_VERSION ||
668 		    result.uint_32 > NFS_MNT3_VERSION)
669 			goto out_of_bounds;
670 		ctx->mount_server.version = result.uint_32;
671 		break;
672 	case Opt_minorversion:
673 		if (result.uint_32 > NFS4_MAX_MINOR_VERSION)
674 			goto out_of_bounds;
675 		ctx->minorversion = result.uint_32;
676 		break;
677 
678 		/*
679 		 * options that take text values
680 		 */
681 	case Opt_v:
682 		ret = nfs_parse_version_string(fc, param->key + 1);
683 		if (ret < 0)
684 			return ret;
685 		break;
686 	case Opt_vers:
687 		if (!param->string)
688 			goto out_invalid_value;
689 		trace_nfs_mount_assign(param->key, param->string);
690 		ret = nfs_parse_version_string(fc, param->string);
691 		if (ret < 0)
692 			return ret;
693 		break;
694 	case Opt_sec:
695 		ret = nfs_parse_security_flavors(fc, param);
696 		if (ret < 0)
697 			return ret;
698 		break;
699 
700 	case Opt_proto:
701 		if (!param->string)
702 			goto out_invalid_value;
703 		trace_nfs_mount_assign(param->key, param->string);
704 		protofamily = AF_INET;
705 		switch (lookup_constant(nfs_xprt_protocol_tokens, param->string, -1)) {
706 		case Opt_xprt_udp6:
707 			protofamily = AF_INET6;
708 			fallthrough;
709 		case Opt_xprt_udp:
710 			ctx->flags &= ~NFS_MOUNT_TCP;
711 			ctx->nfs_server.protocol = XPRT_TRANSPORT_UDP;
712 			break;
713 		case Opt_xprt_tcp6:
714 			protofamily = AF_INET6;
715 			fallthrough;
716 		case Opt_xprt_tcp:
717 			ctx->flags |= NFS_MOUNT_TCP;
718 			ctx->nfs_server.protocol = XPRT_TRANSPORT_TCP;
719 			break;
720 		case Opt_xprt_rdma6:
721 			protofamily = AF_INET6;
722 			fallthrough;
723 		case Opt_xprt_rdma:
724 			/* vector side protocols to TCP */
725 			ctx->flags |= NFS_MOUNT_TCP;
726 			ret = xprt_find_transport_ident(param->string);
727 			if (ret < 0)
728 				goto out_bad_transport;
729 			ctx->nfs_server.protocol = ret;
730 			break;
731 		default:
732 			goto out_bad_transport;
733 		}
734 
735 		ctx->protofamily = protofamily;
736 		break;
737 
738 	case Opt_mountproto:
739 		if (!param->string)
740 			goto out_invalid_value;
741 		trace_nfs_mount_assign(param->key, param->string);
742 		mountfamily = AF_INET;
743 		switch (lookup_constant(nfs_xprt_protocol_tokens, param->string, -1)) {
744 		case Opt_xprt_udp6:
745 			mountfamily = AF_INET6;
746 			fallthrough;
747 		case Opt_xprt_udp:
748 			ctx->mount_server.protocol = XPRT_TRANSPORT_UDP;
749 			break;
750 		case Opt_xprt_tcp6:
751 			mountfamily = AF_INET6;
752 			fallthrough;
753 		case Opt_xprt_tcp:
754 			ctx->mount_server.protocol = XPRT_TRANSPORT_TCP;
755 			break;
756 		case Opt_xprt_rdma: /* not used for side protocols */
757 		default:
758 			goto out_bad_transport;
759 		}
760 		ctx->mountfamily = mountfamily;
761 		break;
762 
763 	case Opt_addr:
764 		trace_nfs_mount_assign(param->key, param->string);
765 		len = rpc_pton(fc->net_ns, param->string, param->size,
766 			       &ctx->nfs_server.address,
767 			       sizeof(ctx->nfs_server._address));
768 		if (len == 0)
769 			goto out_invalid_address;
770 		ctx->nfs_server.addrlen = len;
771 		break;
772 	case Opt_clientaddr:
773 		trace_nfs_mount_assign(param->key, param->string);
774 		kfree(ctx->client_address);
775 		ctx->client_address = param->string;
776 		param->string = NULL;
777 		break;
778 	case Opt_mounthost:
779 		trace_nfs_mount_assign(param->key, param->string);
780 		kfree(ctx->mount_server.hostname);
781 		ctx->mount_server.hostname = param->string;
782 		param->string = NULL;
783 		break;
784 	case Opt_mountaddr:
785 		trace_nfs_mount_assign(param->key, param->string);
786 		len = rpc_pton(fc->net_ns, param->string, param->size,
787 			       &ctx->mount_server.address,
788 			       sizeof(ctx->mount_server._address));
789 		if (len == 0)
790 			goto out_invalid_address;
791 		ctx->mount_server.addrlen = len;
792 		break;
793 	case Opt_nconnect:
794 		if (result.uint_32 < 1 || result.uint_32 > NFS_MAX_CONNECTIONS)
795 			goto out_of_bounds;
796 		ctx->nfs_server.nconnect = result.uint_32;
797 		break;
798 	case Opt_max_connect:
799 		if (result.uint_32 < 1 || result.uint_32 > NFS_MAX_TRANSPORTS)
800 			goto out_of_bounds;
801 		ctx->nfs_server.max_connect = result.uint_32;
802 		break;
803 	case Opt_lookupcache:
804 		switch (result.uint_32) {
805 		case Opt_lookupcache_all:
806 			ctx->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
807 			break;
808 		case Opt_lookupcache_positive:
809 			ctx->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
810 			ctx->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
811 			break;
812 		case Opt_lookupcache_none:
813 			ctx->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
814 			break;
815 		default:
816 			goto out_invalid_value;
817 		}
818 		break;
819 	case Opt_local_lock:
820 		switch (result.uint_32) {
821 		case Opt_local_lock_all:
822 			ctx->flags |= (NFS_MOUNT_LOCAL_FLOCK |
823 				       NFS_MOUNT_LOCAL_FCNTL);
824 			break;
825 		case Opt_local_lock_flock:
826 			ctx->flags |= NFS_MOUNT_LOCAL_FLOCK;
827 			break;
828 		case Opt_local_lock_posix:
829 			ctx->flags |= NFS_MOUNT_LOCAL_FCNTL;
830 			break;
831 		case Opt_local_lock_none:
832 			ctx->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
833 					NFS_MOUNT_LOCAL_FCNTL);
834 			break;
835 		default:
836 			goto out_invalid_value;
837 		}
838 		break;
839 	case Opt_write:
840 		switch (result.uint_32) {
841 		case Opt_write_lazy:
842 			ctx->flags &=
843 				~(NFS_MOUNT_WRITE_EAGER | NFS_MOUNT_WRITE_WAIT);
844 			break;
845 		case Opt_write_eager:
846 			ctx->flags |= NFS_MOUNT_WRITE_EAGER;
847 			ctx->flags &= ~NFS_MOUNT_WRITE_WAIT;
848 			break;
849 		case Opt_write_wait:
850 			ctx->flags |=
851 				NFS_MOUNT_WRITE_EAGER | NFS_MOUNT_WRITE_WAIT;
852 			break;
853 		default:
854 			goto out_invalid_value;
855 		}
856 		break;
857 
858 		/*
859 		 * Special options
860 		 */
861 	case Opt_sloppy:
862 		ctx->sloppy = true;
863 		break;
864 	}
865 
866 	return 0;
867 
868 out_invalid_value:
869 	return nfs_invalf(fc, "NFS: Bad mount option value specified");
870 out_invalid_address:
871 	return nfs_invalf(fc, "NFS: Bad IP address specified");
872 out_of_bounds:
873 	return nfs_invalf(fc, "NFS: Value for '%s' out of range", param->key);
874 out_bad_transport:
875 	return nfs_invalf(fc, "NFS: Unrecognized transport protocol");
876 }
877 
878 /*
879  * Split fc->source into "hostname:export_path".
880  *
881  * The leftmost colon demarks the split between the server's hostname
882  * and the export path.  If the hostname starts with a left square
883  * bracket, then it may contain colons.
884  *
885  * Note: caller frees hostname and export path, even on error.
886  */
887 static int nfs_parse_source(struct fs_context *fc,
888 			    size_t maxnamlen, size_t maxpathlen)
889 {
890 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
891 	const char *dev_name = fc->source;
892 	size_t len;
893 	const char *end;
894 
895 	if (unlikely(!dev_name || !*dev_name))
896 		return -EINVAL;
897 
898 	/* Is the host name protected with square brakcets? */
899 	if (*dev_name == '[') {
900 		end = strchr(++dev_name, ']');
901 		if (end == NULL || end[1] != ':')
902 			goto out_bad_devname;
903 
904 		len = end - dev_name;
905 		end++;
906 	} else {
907 		const char *comma;
908 
909 		end = strchr(dev_name, ':');
910 		if (end == NULL)
911 			goto out_bad_devname;
912 		len = end - dev_name;
913 
914 		/* kill possible hostname list: not supported */
915 		comma = memchr(dev_name, ',', len);
916 		if (comma)
917 			len = comma - dev_name;
918 	}
919 
920 	if (len > maxnamlen)
921 		goto out_hostname;
922 
923 	kfree(ctx->nfs_server.hostname);
924 
925 	/* N.B. caller will free nfs_server.hostname in all cases */
926 	ctx->nfs_server.hostname = kmemdup_nul(dev_name, len, GFP_KERNEL);
927 	if (!ctx->nfs_server.hostname)
928 		goto out_nomem;
929 	len = strlen(++end);
930 	if (len > maxpathlen)
931 		goto out_path;
932 	ctx->nfs_server.export_path = kmemdup_nul(end, len, GFP_KERNEL);
933 	if (!ctx->nfs_server.export_path)
934 		goto out_nomem;
935 
936 	trace_nfs_mount_path(ctx->nfs_server.export_path);
937 	return 0;
938 
939 out_bad_devname:
940 	return nfs_invalf(fc, "NFS: device name not in host:path format");
941 out_nomem:
942 	nfs_errorf(fc, "NFS: not enough memory to parse device name");
943 	return -ENOMEM;
944 out_hostname:
945 	nfs_errorf(fc, "NFS: server hostname too long");
946 	return -ENAMETOOLONG;
947 out_path:
948 	nfs_errorf(fc, "NFS: export pathname too long");
949 	return -ENAMETOOLONG;
950 }
951 
952 static inline bool is_remount_fc(struct fs_context *fc)
953 {
954 	return fc->root != NULL;
955 }
956 
957 /*
958  * Parse monolithic NFS2/NFS3 mount data
959  * - fills in the mount root filehandle
960  *
961  * For option strings, user space handles the following behaviors:
962  *
963  * + DNS: mapping server host name to IP address ("addr=" option)
964  *
965  * + failure mode: how to behave if a mount request can't be handled
966  *   immediately ("fg/bg" option)
967  *
968  * + retry: how often to retry a mount request ("retry=" option)
969  *
970  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
971  *   mountproto=tcp after mountproto=udp, and so on
972  */
973 static int nfs23_parse_monolithic(struct fs_context *fc,
974 				  struct nfs_mount_data *data)
975 {
976 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
977 	struct nfs_fh *mntfh = ctx->mntfh;
978 	struct sockaddr_storage *sap = &ctx->nfs_server._address;
979 	int extra_flags = NFS_MOUNT_LEGACY_INTERFACE;
980 	int ret;
981 
982 	if (data == NULL)
983 		goto out_no_data;
984 
985 	ctx->version = NFS_DEFAULT_VERSION;
986 	switch (data->version) {
987 	case 1:
988 		data->namlen = 0;
989 		fallthrough;
990 	case 2:
991 		data->bsize = 0;
992 		fallthrough;
993 	case 3:
994 		if (data->flags & NFS_MOUNT_VER3)
995 			goto out_no_v3;
996 		data->root.size = NFS2_FHSIZE;
997 		memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
998 		/* Turn off security negotiation */
999 		extra_flags |= NFS_MOUNT_SECFLAVOUR;
1000 		fallthrough;
1001 	case 4:
1002 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
1003 			goto out_no_sec;
1004 		fallthrough;
1005 	case 5:
1006 		memset(data->context, 0, sizeof(data->context));
1007 		fallthrough;
1008 	case 6:
1009 		if (data->flags & NFS_MOUNT_VER3) {
1010 			if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1011 				goto out_invalid_fh;
1012 			mntfh->size = data->root.size;
1013 			ctx->version = 3;
1014 		} else {
1015 			mntfh->size = NFS2_FHSIZE;
1016 			ctx->version = 2;
1017 		}
1018 
1019 
1020 		memcpy(mntfh->data, data->root.data, mntfh->size);
1021 		if (mntfh->size < sizeof(mntfh->data))
1022 			memset(mntfh->data + mntfh->size, 0,
1023 			       sizeof(mntfh->data) - mntfh->size);
1024 
1025 		/*
1026 		 * for proto == XPRT_TRANSPORT_UDP, which is what uses
1027 		 * to_exponential, implying shift: limit the shift value
1028 		 * to BITS_PER_LONG (majortimeo is unsigned long)
1029 		 */
1030 		if (!(data->flags & NFS_MOUNT_TCP)) /* this will be UDP */
1031 			if (data->retrans >= 64) /* shift value is too large */
1032 				goto out_invalid_data;
1033 
1034 		/*
1035 		 * Translate to nfs_fs_context, which nfs_fill_super
1036 		 * can deal with.
1037 		 */
1038 		ctx->flags	= data->flags & NFS_MOUNT_FLAGMASK;
1039 		ctx->flags	|= extra_flags;
1040 		ctx->rsize	= data->rsize;
1041 		ctx->wsize	= data->wsize;
1042 		ctx->timeo	= data->timeo;
1043 		ctx->retrans	= data->retrans;
1044 		ctx->acregmin	= data->acregmin;
1045 		ctx->acregmax	= data->acregmax;
1046 		ctx->acdirmin	= data->acdirmin;
1047 		ctx->acdirmax	= data->acdirmax;
1048 		ctx->need_mount	= false;
1049 
1050 		memcpy(sap, &data->addr, sizeof(data->addr));
1051 		ctx->nfs_server.addrlen = sizeof(data->addr);
1052 		ctx->nfs_server.port = ntohs(data->addr.sin_port);
1053 		if (sap->ss_family != AF_INET ||
1054 		    !nfs_verify_server_address(sap))
1055 			goto out_no_address;
1056 
1057 		if (!(data->flags & NFS_MOUNT_TCP))
1058 			ctx->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1059 		/* N.B. caller will free nfs_server.hostname in all cases */
1060 		ctx->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1061 		if (!ctx->nfs_server.hostname)
1062 			goto out_nomem;
1063 
1064 		ctx->namlen		= data->namlen;
1065 		ctx->bsize		= data->bsize;
1066 
1067 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
1068 			ctx->selected_flavor = data->pseudoflavor;
1069 		else
1070 			ctx->selected_flavor = RPC_AUTH_UNIX;
1071 
1072 		if (!(data->flags & NFS_MOUNT_NONLM))
1073 			ctx->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
1074 					 NFS_MOUNT_LOCAL_FCNTL);
1075 		else
1076 			ctx->flags |= (NFS_MOUNT_LOCAL_FLOCK|
1077 					NFS_MOUNT_LOCAL_FCNTL);
1078 
1079 		/*
1080 		 * The legacy version 6 binary mount data from userspace has a
1081 		 * field used only to transport selinux information into the
1082 		 * kernel.  To continue to support that functionality we
1083 		 * have a touch of selinux knowledge here in the NFS code. The
1084 		 * userspace code converted context=blah to just blah so we are
1085 		 * converting back to the full string selinux understands.
1086 		 */
1087 		if (data->context[0]){
1088 #ifdef CONFIG_SECURITY_SELINUX
1089 			int ret;
1090 
1091 			data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1092 			ret = vfs_parse_fs_string(fc, "context",
1093 						  data->context, strlen(data->context));
1094 			if (ret < 0)
1095 				return ret;
1096 #else
1097 			return -EINVAL;
1098 #endif
1099 		}
1100 
1101 		break;
1102 	default:
1103 		goto generic;
1104 	}
1105 
1106 	ret = nfs_validate_transport_protocol(fc, ctx);
1107 	if (ret)
1108 		return ret;
1109 
1110 	ctx->skip_reconfig_option_check = true;
1111 	return 0;
1112 
1113 generic:
1114 	return generic_parse_monolithic(fc, data);
1115 
1116 out_no_data:
1117 	if (is_remount_fc(fc)) {
1118 		ctx->skip_reconfig_option_check = true;
1119 		return 0;
1120 	}
1121 	return nfs_invalf(fc, "NFS: mount program didn't pass any mount data");
1122 
1123 out_no_v3:
1124 	return nfs_invalf(fc, "NFS: nfs_mount_data version does not support v3");
1125 
1126 out_no_sec:
1127 	return nfs_invalf(fc, "NFS: nfs_mount_data version supports only AUTH_SYS");
1128 
1129 out_nomem:
1130 	return -ENOMEM;
1131 
1132 out_no_address:
1133 	return nfs_invalf(fc, "NFS: mount program didn't pass remote address");
1134 
1135 out_invalid_fh:
1136 	return nfs_invalf(fc, "NFS: invalid root filehandle");
1137 
1138 out_invalid_data:
1139 	return nfs_invalf(fc, "NFS: invalid binary mount data");
1140 }
1141 
1142 #if IS_ENABLED(CONFIG_NFS_V4)
1143 struct compat_nfs_string {
1144 	compat_uint_t len;
1145 	compat_uptr_t data;
1146 };
1147 
1148 static inline void compat_nfs_string(struct nfs_string *dst,
1149 				     struct compat_nfs_string *src)
1150 {
1151 	dst->data = compat_ptr(src->data);
1152 	dst->len = src->len;
1153 }
1154 
1155 struct compat_nfs4_mount_data_v1 {
1156 	compat_int_t version;
1157 	compat_int_t flags;
1158 	compat_int_t rsize;
1159 	compat_int_t wsize;
1160 	compat_int_t timeo;
1161 	compat_int_t retrans;
1162 	compat_int_t acregmin;
1163 	compat_int_t acregmax;
1164 	compat_int_t acdirmin;
1165 	compat_int_t acdirmax;
1166 	struct compat_nfs_string client_addr;
1167 	struct compat_nfs_string mnt_path;
1168 	struct compat_nfs_string hostname;
1169 	compat_uint_t host_addrlen;
1170 	compat_uptr_t host_addr;
1171 	compat_int_t proto;
1172 	compat_int_t auth_flavourlen;
1173 	compat_uptr_t auth_flavours;
1174 };
1175 
1176 static void nfs4_compat_mount_data_conv(struct nfs4_mount_data *data)
1177 {
1178 	struct compat_nfs4_mount_data_v1 *compat =
1179 			(struct compat_nfs4_mount_data_v1 *)data;
1180 
1181 	/* copy the fields backwards */
1182 	data->auth_flavours = compat_ptr(compat->auth_flavours);
1183 	data->auth_flavourlen = compat->auth_flavourlen;
1184 	data->proto = compat->proto;
1185 	data->host_addr = compat_ptr(compat->host_addr);
1186 	data->host_addrlen = compat->host_addrlen;
1187 	compat_nfs_string(&data->hostname, &compat->hostname);
1188 	compat_nfs_string(&data->mnt_path, &compat->mnt_path);
1189 	compat_nfs_string(&data->client_addr, &compat->client_addr);
1190 	data->acdirmax = compat->acdirmax;
1191 	data->acdirmin = compat->acdirmin;
1192 	data->acregmax = compat->acregmax;
1193 	data->acregmin = compat->acregmin;
1194 	data->retrans = compat->retrans;
1195 	data->timeo = compat->timeo;
1196 	data->wsize = compat->wsize;
1197 	data->rsize = compat->rsize;
1198 	data->flags = compat->flags;
1199 	data->version = compat->version;
1200 }
1201 
1202 /*
1203  * Validate NFSv4 mount options
1204  */
1205 static int nfs4_parse_monolithic(struct fs_context *fc,
1206 				 struct nfs4_mount_data *data)
1207 {
1208 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
1209 	struct sockaddr_storage *sap = &ctx->nfs_server._address;
1210 	int ret;
1211 	char *c;
1212 
1213 	if (!data) {
1214 		if (is_remount_fc(fc))
1215 			goto done;
1216 		return nfs_invalf(fc,
1217 			"NFS4: mount program didn't pass any mount data");
1218 	}
1219 
1220 	ctx->version = 4;
1221 
1222 	if (data->version != 1)
1223 		return generic_parse_monolithic(fc, data);
1224 
1225 	if (in_compat_syscall())
1226 		nfs4_compat_mount_data_conv(data);
1227 
1228 	if (data->host_addrlen > sizeof(ctx->nfs_server.address))
1229 		goto out_no_address;
1230 	if (data->host_addrlen == 0)
1231 		goto out_no_address;
1232 	ctx->nfs_server.addrlen = data->host_addrlen;
1233 	if (copy_from_user(sap, data->host_addr, data->host_addrlen))
1234 		return -EFAULT;
1235 	if (!nfs_verify_server_address(sap))
1236 		goto out_no_address;
1237 	ctx->nfs_server.port = ntohs(((struct sockaddr_in *)sap)->sin_port);
1238 
1239 	if (data->auth_flavourlen) {
1240 		rpc_authflavor_t pseudoflavor;
1241 
1242 		if (data->auth_flavourlen > 1)
1243 			goto out_inval_auth;
1244 		if (copy_from_user(&pseudoflavor, data->auth_flavours,
1245 				   sizeof(pseudoflavor)))
1246 			return -EFAULT;
1247 		ctx->selected_flavor = pseudoflavor;
1248 	} else {
1249 		ctx->selected_flavor = RPC_AUTH_UNIX;
1250 	}
1251 
1252 	c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
1253 	if (IS_ERR(c))
1254 		return PTR_ERR(c);
1255 	ctx->nfs_server.hostname = c;
1256 
1257 	c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
1258 	if (IS_ERR(c))
1259 		return PTR_ERR(c);
1260 	ctx->nfs_server.export_path = c;
1261 	trace_nfs_mount_path(c);
1262 
1263 	c = strndup_user(data->client_addr.data, 16);
1264 	if (IS_ERR(c))
1265 		return PTR_ERR(c);
1266 	ctx->client_address = c;
1267 
1268 	/*
1269 	 * Translate to nfs_fs_context, which nfs_fill_super
1270 	 * can deal with.
1271 	 */
1272 
1273 	ctx->flags	= data->flags & NFS4_MOUNT_FLAGMASK;
1274 	ctx->rsize	= data->rsize;
1275 	ctx->wsize	= data->wsize;
1276 	ctx->timeo	= data->timeo;
1277 	ctx->retrans	= data->retrans;
1278 	ctx->acregmin	= data->acregmin;
1279 	ctx->acregmax	= data->acregmax;
1280 	ctx->acdirmin	= data->acdirmin;
1281 	ctx->acdirmax	= data->acdirmax;
1282 	ctx->nfs_server.protocol = data->proto;
1283 	ret = nfs_validate_transport_protocol(fc, ctx);
1284 	if (ret)
1285 		return ret;
1286 done:
1287 	ctx->skip_reconfig_option_check = true;
1288 	return 0;
1289 
1290 out_inval_auth:
1291 	return nfs_invalf(fc, "NFS4: Invalid number of RPC auth flavours %d",
1292 		      data->auth_flavourlen);
1293 
1294 out_no_address:
1295 	return nfs_invalf(fc, "NFS4: mount program didn't pass remote address");
1296 }
1297 #endif
1298 
1299 /*
1300  * Parse a monolithic block of data from sys_mount().
1301  */
1302 static int nfs_fs_context_parse_monolithic(struct fs_context *fc,
1303 					   void *data)
1304 {
1305 	if (fc->fs_type == &nfs_fs_type)
1306 		return nfs23_parse_monolithic(fc, data);
1307 
1308 #if IS_ENABLED(CONFIG_NFS_V4)
1309 	if (fc->fs_type == &nfs4_fs_type)
1310 		return nfs4_parse_monolithic(fc, data);
1311 #endif
1312 
1313 	return nfs_invalf(fc, "NFS: Unsupported monolithic data version");
1314 }
1315 
1316 /*
1317  * Validate the preparsed information in the config.
1318  */
1319 static int nfs_fs_context_validate(struct fs_context *fc)
1320 {
1321 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
1322 	struct nfs_subversion *nfs_mod;
1323 	struct sockaddr_storage *sap = &ctx->nfs_server._address;
1324 	int max_namelen = PAGE_SIZE;
1325 	int max_pathlen = NFS_MAXPATHLEN;
1326 	int port = 0;
1327 	int ret;
1328 
1329 	if (!fc->source)
1330 		goto out_no_device_name;
1331 
1332 	/* Check for sanity first. */
1333 	if (ctx->minorversion && ctx->version != 4)
1334 		goto out_minorversion_mismatch;
1335 
1336 	if (ctx->options & NFS_OPTION_MIGRATION &&
1337 	    (ctx->version != 4 || ctx->minorversion != 0))
1338 		goto out_migration_misuse;
1339 
1340 	/* Verify that any proto=/mountproto= options match the address
1341 	 * families in the addr=/mountaddr= options.
1342 	 */
1343 	if (ctx->protofamily != AF_UNSPEC &&
1344 	    ctx->protofamily != ctx->nfs_server.address.sa_family)
1345 		goto out_proto_mismatch;
1346 
1347 	if (ctx->mountfamily != AF_UNSPEC) {
1348 		if (ctx->mount_server.addrlen) {
1349 			if (ctx->mountfamily != ctx->mount_server.address.sa_family)
1350 				goto out_mountproto_mismatch;
1351 		} else {
1352 			if (ctx->mountfamily != ctx->nfs_server.address.sa_family)
1353 				goto out_mountproto_mismatch;
1354 		}
1355 	}
1356 
1357 	if (!nfs_verify_server_address(sap))
1358 		goto out_no_address;
1359 
1360 	ret = nfs_validate_transport_protocol(fc, ctx);
1361 	if (ret)
1362 		return ret;
1363 
1364 	if (ctx->version == 4) {
1365 		if (IS_ENABLED(CONFIG_NFS_V4)) {
1366 			if (ctx->nfs_server.protocol == XPRT_TRANSPORT_RDMA)
1367 				port = NFS_RDMA_PORT;
1368 			else
1369 				port = NFS_PORT;
1370 			max_namelen = NFS4_MAXNAMLEN;
1371 			max_pathlen = NFS4_MAXPATHLEN;
1372 			ctx->flags &= ~(NFS_MOUNT_NONLM | NFS_MOUNT_NOACL |
1373 					NFS_MOUNT_VER3 | NFS_MOUNT_LOCAL_FLOCK |
1374 					NFS_MOUNT_LOCAL_FCNTL);
1375 		} else {
1376 			goto out_v4_not_compiled;
1377 		}
1378 	} else {
1379 		nfs_set_mount_transport_protocol(ctx);
1380 		if (ctx->nfs_server.protocol == XPRT_TRANSPORT_RDMA)
1381 			port = NFS_RDMA_PORT;
1382 	}
1383 
1384 	nfs_set_port(sap, &ctx->nfs_server.port, port);
1385 
1386 	ret = nfs_parse_source(fc, max_namelen, max_pathlen);
1387 	if (ret < 0)
1388 		return ret;
1389 
1390 	/* Load the NFS protocol module if we haven't done so yet */
1391 	if (!ctx->nfs_mod) {
1392 		nfs_mod = get_nfs_version(ctx->version);
1393 		if (IS_ERR(nfs_mod)) {
1394 			ret = PTR_ERR(nfs_mod);
1395 			goto out_version_unavailable;
1396 		}
1397 		ctx->nfs_mod = nfs_mod;
1398 	}
1399 
1400 	/* Ensure the filesystem context has the correct fs_type */
1401 	if (fc->fs_type != ctx->nfs_mod->nfs_fs) {
1402 		module_put(fc->fs_type->owner);
1403 		__module_get(ctx->nfs_mod->nfs_fs->owner);
1404 		fc->fs_type = ctx->nfs_mod->nfs_fs;
1405 	}
1406 	return 0;
1407 
1408 out_no_device_name:
1409 	return nfs_invalf(fc, "NFS: Device name not specified");
1410 out_v4_not_compiled:
1411 	nfs_errorf(fc, "NFS: NFSv4 is not compiled into kernel");
1412 	return -EPROTONOSUPPORT;
1413 out_no_address:
1414 	return nfs_invalf(fc, "NFS: mount program didn't pass remote address");
1415 out_mountproto_mismatch:
1416 	return nfs_invalf(fc, "NFS: Mount server address does not match mountproto= option");
1417 out_proto_mismatch:
1418 	return nfs_invalf(fc, "NFS: Server address does not match proto= option");
1419 out_minorversion_mismatch:
1420 	return nfs_invalf(fc, "NFS: Mount option vers=%u does not support minorversion=%u",
1421 			  ctx->version, ctx->minorversion);
1422 out_migration_misuse:
1423 	return nfs_invalf(fc, "NFS: 'Migration' not supported for this NFS version");
1424 out_version_unavailable:
1425 	nfs_errorf(fc, "NFS: Version unavailable");
1426 	return ret;
1427 }
1428 
1429 /*
1430  * Create an NFS superblock by the appropriate method.
1431  */
1432 static int nfs_get_tree(struct fs_context *fc)
1433 {
1434 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
1435 	int err = nfs_fs_context_validate(fc);
1436 
1437 	if (err)
1438 		return err;
1439 	if (!ctx->internal)
1440 		return ctx->nfs_mod->rpc_ops->try_get_tree(fc);
1441 	else
1442 		return nfs_get_tree_common(fc);
1443 }
1444 
1445 /*
1446  * Handle duplication of a configuration.  The caller copied *src into *sc, but
1447  * it can't deal with resource pointers in the filesystem context, so we have
1448  * to do that.  We need to clear pointers, copy data or get extra refs as
1449  * appropriate.
1450  */
1451 static int nfs_fs_context_dup(struct fs_context *fc, struct fs_context *src_fc)
1452 {
1453 	struct nfs_fs_context *src = nfs_fc2context(src_fc), *ctx;
1454 
1455 	ctx = kmemdup(src, sizeof(struct nfs_fs_context), GFP_KERNEL);
1456 	if (!ctx)
1457 		return -ENOMEM;
1458 
1459 	ctx->mntfh = nfs_alloc_fhandle();
1460 	if (!ctx->mntfh) {
1461 		kfree(ctx);
1462 		return -ENOMEM;
1463 	}
1464 	nfs_copy_fh(ctx->mntfh, src->mntfh);
1465 
1466 	__module_get(ctx->nfs_mod->owner);
1467 	ctx->client_address		= NULL;
1468 	ctx->mount_server.hostname	= NULL;
1469 	ctx->nfs_server.export_path	= NULL;
1470 	ctx->nfs_server.hostname	= NULL;
1471 	ctx->fscache_uniq		= NULL;
1472 	ctx->clone_data.fattr		= NULL;
1473 	fc->fs_private = ctx;
1474 	return 0;
1475 }
1476 
1477 static void nfs_fs_context_free(struct fs_context *fc)
1478 {
1479 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
1480 
1481 	if (ctx) {
1482 		if (ctx->server)
1483 			nfs_free_server(ctx->server);
1484 		if (ctx->nfs_mod)
1485 			put_nfs_version(ctx->nfs_mod);
1486 		kfree(ctx->client_address);
1487 		kfree(ctx->mount_server.hostname);
1488 		kfree(ctx->nfs_server.export_path);
1489 		kfree(ctx->nfs_server.hostname);
1490 		kfree(ctx->fscache_uniq);
1491 		nfs_free_fhandle(ctx->mntfh);
1492 		nfs_free_fattr(ctx->clone_data.fattr);
1493 		kfree(ctx);
1494 	}
1495 }
1496 
1497 static const struct fs_context_operations nfs_fs_context_ops = {
1498 	.free			= nfs_fs_context_free,
1499 	.dup			= nfs_fs_context_dup,
1500 	.parse_param		= nfs_fs_context_parse_param,
1501 	.parse_monolithic	= nfs_fs_context_parse_monolithic,
1502 	.get_tree		= nfs_get_tree,
1503 	.reconfigure		= nfs_reconfigure,
1504 };
1505 
1506 /*
1507  * Prepare superblock configuration.  We use the namespaces attached to the
1508  * context.  This may be the current process's namespaces, or it may be a
1509  * container's namespaces.
1510  */
1511 static int nfs_init_fs_context(struct fs_context *fc)
1512 {
1513 	struct nfs_fs_context *ctx;
1514 
1515 	ctx = kzalloc(sizeof(struct nfs_fs_context), GFP_KERNEL);
1516 	if (unlikely(!ctx))
1517 		return -ENOMEM;
1518 
1519 	ctx->mntfh = nfs_alloc_fhandle();
1520 	if (unlikely(!ctx->mntfh)) {
1521 		kfree(ctx);
1522 		return -ENOMEM;
1523 	}
1524 
1525 	ctx->protofamily	= AF_UNSPEC;
1526 	ctx->mountfamily	= AF_UNSPEC;
1527 	ctx->mount_server.port	= NFS_UNSPEC_PORT;
1528 
1529 	if (fc->root) {
1530 		/* reconfigure, start with the current config */
1531 		struct nfs_server *nfss = fc->root->d_sb->s_fs_info;
1532 		struct net *net = nfss->nfs_client->cl_net;
1533 
1534 		ctx->flags		= nfss->flags;
1535 		ctx->rsize		= nfss->rsize;
1536 		ctx->wsize		= nfss->wsize;
1537 		ctx->retrans		= nfss->client->cl_timeout->to_retries;
1538 		ctx->selected_flavor	= nfss->client->cl_auth->au_flavor;
1539 		ctx->acregmin		= nfss->acregmin / HZ;
1540 		ctx->acregmax		= nfss->acregmax / HZ;
1541 		ctx->acdirmin		= nfss->acdirmin / HZ;
1542 		ctx->acdirmax		= nfss->acdirmax / HZ;
1543 		ctx->timeo		= 10U * nfss->client->cl_timeout->to_initval / HZ;
1544 		ctx->nfs_server.port	= nfss->port;
1545 		ctx->nfs_server.addrlen	= nfss->nfs_client->cl_addrlen;
1546 		ctx->version		= nfss->nfs_client->rpc_ops->version;
1547 		ctx->minorversion	= nfss->nfs_client->cl_minorversion;
1548 
1549 		memcpy(&ctx->nfs_server._address, &nfss->nfs_client->cl_addr,
1550 			ctx->nfs_server.addrlen);
1551 
1552 		if (fc->net_ns != net) {
1553 			put_net(fc->net_ns);
1554 			fc->net_ns = get_net(net);
1555 		}
1556 
1557 		ctx->nfs_mod = nfss->nfs_client->cl_nfs_mod;
1558 		__module_get(ctx->nfs_mod->owner);
1559 	} else {
1560 		/* defaults */
1561 		ctx->timeo		= NFS_UNSPEC_TIMEO;
1562 		ctx->retrans		= NFS_UNSPEC_RETRANS;
1563 		ctx->acregmin		= NFS_DEF_ACREGMIN;
1564 		ctx->acregmax		= NFS_DEF_ACREGMAX;
1565 		ctx->acdirmin		= NFS_DEF_ACDIRMIN;
1566 		ctx->acdirmax		= NFS_DEF_ACDIRMAX;
1567 		ctx->nfs_server.port	= NFS_UNSPEC_PORT;
1568 		ctx->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1569 		ctx->selected_flavor	= RPC_AUTH_MAXFLAVOR;
1570 		ctx->minorversion	= 0;
1571 		ctx->need_mount		= true;
1572 
1573 		fc->s_iflags		|= SB_I_STABLE_WRITES;
1574 	}
1575 	fc->fs_private = ctx;
1576 	fc->ops = &nfs_fs_context_ops;
1577 	return 0;
1578 }
1579 
1580 struct file_system_type nfs_fs_type = {
1581 	.owner			= THIS_MODULE,
1582 	.name			= "nfs",
1583 	.init_fs_context	= nfs_init_fs_context,
1584 	.parameters		= nfs_fs_parameters,
1585 	.kill_sb		= nfs_kill_super,
1586 	.fs_flags		= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
1587 };
1588 MODULE_ALIAS_FS("nfs");
1589 EXPORT_SYMBOL_GPL(nfs_fs_type);
1590 
1591 #if IS_ENABLED(CONFIG_NFS_V4)
1592 struct file_system_type nfs4_fs_type = {
1593 	.owner			= THIS_MODULE,
1594 	.name			= "nfs4",
1595 	.init_fs_context	= nfs_init_fs_context,
1596 	.parameters		= nfs_fs_parameters,
1597 	.kill_sb		= nfs_kill_super,
1598 	.fs_flags		= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
1599 };
1600 MODULE_ALIAS_FS("nfs4");
1601 MODULE_ALIAS("nfs4");
1602 EXPORT_SYMBOL_GPL(nfs4_fs_type);
1603 #endif /* CONFIG_NFS_V4 */
1604