xref: /linux/fs/nfs/fs_context.c (revision dec1c62e91ba268ab2a6e339d4d7a59287d5eba1)
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 #define NFSDBG_FACILITY		NFSDBG_MOUNT
25 
26 #if IS_ENABLED(CONFIG_NFS_V3)
27 #define NFS_DEFAULT_VERSION 3
28 #else
29 #define NFS_DEFAULT_VERSION 2
30 #endif
31 
32 #define NFS_MAX_CONNECTIONS 16
33 
34 enum nfs_param {
35 	Opt_ac,
36 	Opt_acdirmax,
37 	Opt_acdirmin,
38 	Opt_acl,
39 	Opt_acregmax,
40 	Opt_acregmin,
41 	Opt_actimeo,
42 	Opt_addr,
43 	Opt_bg,
44 	Opt_bsize,
45 	Opt_clientaddr,
46 	Opt_cto,
47 	Opt_fg,
48 	Opt_fscache,
49 	Opt_fscache_flag,
50 	Opt_hard,
51 	Opt_intr,
52 	Opt_local_lock,
53 	Opt_lock,
54 	Opt_lookupcache,
55 	Opt_migration,
56 	Opt_minorversion,
57 	Opt_mountaddr,
58 	Opt_mounthost,
59 	Opt_mountport,
60 	Opt_mountproto,
61 	Opt_mountvers,
62 	Opt_namelen,
63 	Opt_nconnect,
64 	Opt_max_connect,
65 	Opt_port,
66 	Opt_posix,
67 	Opt_proto,
68 	Opt_rdirplus,
69 	Opt_rdma,
70 	Opt_resvport,
71 	Opt_retrans,
72 	Opt_retry,
73 	Opt_rsize,
74 	Opt_sec,
75 	Opt_sharecache,
76 	Opt_sloppy,
77 	Opt_soft,
78 	Opt_softerr,
79 	Opt_softreval,
80 	Opt_source,
81 	Opt_tcp,
82 	Opt_timeo,
83 	Opt_trunkdiscovery,
84 	Opt_udp,
85 	Opt_v,
86 	Opt_vers,
87 	Opt_wsize,
88 	Opt_write,
89 };
90 
91 enum {
92 	Opt_local_lock_all,
93 	Opt_local_lock_flock,
94 	Opt_local_lock_none,
95 	Opt_local_lock_posix,
96 };
97 
98 static const struct constant_table nfs_param_enums_local_lock[] = {
99 	{ "all",		Opt_local_lock_all },
100 	{ "flock",	Opt_local_lock_flock },
101 	{ "posix",	Opt_local_lock_posix },
102 	{ "none",		Opt_local_lock_none },
103 	{}
104 };
105 
106 enum {
107 	Opt_lookupcache_all,
108 	Opt_lookupcache_none,
109 	Opt_lookupcache_positive,
110 };
111 
112 static const struct constant_table nfs_param_enums_lookupcache[] = {
113 	{ "all",		Opt_lookupcache_all },
114 	{ "none",		Opt_lookupcache_none },
115 	{ "pos",		Opt_lookupcache_positive },
116 	{ "positive",		Opt_lookupcache_positive },
117 	{}
118 };
119 
120 enum {
121 	Opt_write_lazy,
122 	Opt_write_eager,
123 	Opt_write_wait,
124 };
125 
126 static const struct constant_table nfs_param_enums_write[] = {
127 	{ "lazy",		Opt_write_lazy },
128 	{ "eager",		Opt_write_eager },
129 	{ "wait",		Opt_write_wait },
130 	{}
131 };
132 
133 static const struct fs_parameter_spec nfs_fs_parameters[] = {
134 	fsparam_flag_no("ac",		Opt_ac),
135 	fsparam_u32   ("acdirmax",	Opt_acdirmax),
136 	fsparam_u32   ("acdirmin",	Opt_acdirmin),
137 	fsparam_flag_no("acl",		Opt_acl),
138 	fsparam_u32   ("acregmax",	Opt_acregmax),
139 	fsparam_u32   ("acregmin",	Opt_acregmin),
140 	fsparam_u32   ("actimeo",	Opt_actimeo),
141 	fsparam_string("addr",		Opt_addr),
142 	fsparam_flag  ("bg",		Opt_bg),
143 	fsparam_u32   ("bsize",		Opt_bsize),
144 	fsparam_string("clientaddr",	Opt_clientaddr),
145 	fsparam_flag_no("cto",		Opt_cto),
146 	fsparam_flag  ("fg",		Opt_fg),
147 	fsparam_flag_no("fsc",		Opt_fscache_flag),
148 	fsparam_string("fsc",		Opt_fscache),
149 	fsparam_flag  ("hard",		Opt_hard),
150 	__fsparam(NULL, "intr",		Opt_intr,
151 		  fs_param_neg_with_no|fs_param_deprecated, NULL),
152 	fsparam_enum  ("local_lock",	Opt_local_lock, nfs_param_enums_local_lock),
153 	fsparam_flag_no("lock",		Opt_lock),
154 	fsparam_enum  ("lookupcache",	Opt_lookupcache, nfs_param_enums_lookupcache),
155 	fsparam_flag_no("migration",	Opt_migration),
156 	fsparam_u32   ("minorversion",	Opt_minorversion),
157 	fsparam_string("mountaddr",	Opt_mountaddr),
158 	fsparam_string("mounthost",	Opt_mounthost),
159 	fsparam_u32   ("mountport",	Opt_mountport),
160 	fsparam_string("mountproto",	Opt_mountproto),
161 	fsparam_u32   ("mountvers",	Opt_mountvers),
162 	fsparam_u32   ("namlen",	Opt_namelen),
163 	fsparam_u32   ("nconnect",	Opt_nconnect),
164 	fsparam_u32   ("max_connect",	Opt_max_connect),
165 	fsparam_string("nfsvers",	Opt_vers),
166 	fsparam_u32   ("port",		Opt_port),
167 	fsparam_flag_no("posix",	Opt_posix),
168 	fsparam_string("proto",		Opt_proto),
169 	fsparam_flag_no("rdirplus",	Opt_rdirplus),
170 	fsparam_flag  ("rdma",		Opt_rdma),
171 	fsparam_flag_no("resvport",	Opt_resvport),
172 	fsparam_u32   ("retrans",	Opt_retrans),
173 	fsparam_string("retry",		Opt_retry),
174 	fsparam_u32   ("rsize",		Opt_rsize),
175 	fsparam_string("sec",		Opt_sec),
176 	fsparam_flag_no("sharecache",	Opt_sharecache),
177 	fsparam_flag  ("sloppy",	Opt_sloppy),
178 	fsparam_flag  ("soft",		Opt_soft),
179 	fsparam_flag  ("softerr",	Opt_softerr),
180 	fsparam_flag  ("softreval",	Opt_softreval),
181 	fsparam_string("source",	Opt_source),
182 	fsparam_flag  ("tcp",		Opt_tcp),
183 	fsparam_u32   ("timeo",		Opt_timeo),
184 	fsparam_flag_no("trunkdiscovery", Opt_trunkdiscovery),
185 	fsparam_flag  ("udp",		Opt_udp),
186 	fsparam_flag  ("v2",		Opt_v),
187 	fsparam_flag  ("v3",		Opt_v),
188 	fsparam_flag  ("v4",		Opt_v),
189 	fsparam_flag  ("v4.0",		Opt_v),
190 	fsparam_flag  ("v4.1",		Opt_v),
191 	fsparam_flag  ("v4.2",		Opt_v),
192 	fsparam_string("vers",		Opt_vers),
193 	fsparam_enum  ("write",		Opt_write, nfs_param_enums_write),
194 	fsparam_u32   ("wsize",		Opt_wsize),
195 	{}
196 };
197 
198 enum {
199 	Opt_vers_2,
200 	Opt_vers_3,
201 	Opt_vers_4,
202 	Opt_vers_4_0,
203 	Opt_vers_4_1,
204 	Opt_vers_4_2,
205 };
206 
207 static const struct constant_table nfs_vers_tokens[] = {
208 	{ "2",		Opt_vers_2 },
209 	{ "3",		Opt_vers_3 },
210 	{ "4",		Opt_vers_4 },
211 	{ "4.0",	Opt_vers_4_0 },
212 	{ "4.1",	Opt_vers_4_1 },
213 	{ "4.2",	Opt_vers_4_2 },
214 	{}
215 };
216 
217 enum {
218 	Opt_xprt_rdma,
219 	Opt_xprt_rdma6,
220 	Opt_xprt_tcp,
221 	Opt_xprt_tcp6,
222 	Opt_xprt_udp,
223 	Opt_xprt_udp6,
224 	nr__Opt_xprt
225 };
226 
227 static const struct constant_table nfs_xprt_protocol_tokens[] = {
228 	{ "rdma",	Opt_xprt_rdma },
229 	{ "rdma6",	Opt_xprt_rdma6 },
230 	{ "tcp",	Opt_xprt_tcp },
231 	{ "tcp6",	Opt_xprt_tcp6 },
232 	{ "udp",	Opt_xprt_udp },
233 	{ "udp6",	Opt_xprt_udp6 },
234 	{}
235 };
236 
237 enum {
238 	Opt_sec_krb5,
239 	Opt_sec_krb5i,
240 	Opt_sec_krb5p,
241 	Opt_sec_lkey,
242 	Opt_sec_lkeyi,
243 	Opt_sec_lkeyp,
244 	Opt_sec_none,
245 	Opt_sec_spkm,
246 	Opt_sec_spkmi,
247 	Opt_sec_spkmp,
248 	Opt_sec_sys,
249 	nr__Opt_sec
250 };
251 
252 static const struct constant_table nfs_secflavor_tokens[] = {
253 	{ "krb5",	Opt_sec_krb5 },
254 	{ "krb5i",	Opt_sec_krb5i },
255 	{ "krb5p",	Opt_sec_krb5p },
256 	{ "lkey",	Opt_sec_lkey },
257 	{ "lkeyi",	Opt_sec_lkeyi },
258 	{ "lkeyp",	Opt_sec_lkeyp },
259 	{ "none",	Opt_sec_none },
260 	{ "null",	Opt_sec_none },
261 	{ "spkm3",	Opt_sec_spkm },
262 	{ "spkm3i",	Opt_sec_spkmi },
263 	{ "spkm3p",	Opt_sec_spkmp },
264 	{ "sys",	Opt_sec_sys },
265 	{}
266 };
267 
268 /*
269  * Sanity-check a server address provided by the mount command.
270  *
271  * Address family must be initialized, and address must not be
272  * the ANY address for that family.
273  */
274 static int nfs_verify_server_address(struct sockaddr *addr)
275 {
276 	switch (addr->sa_family) {
277 	case AF_INET: {
278 		struct sockaddr_in *sa = (struct sockaddr_in *)addr;
279 		return sa->sin_addr.s_addr != htonl(INADDR_ANY);
280 	}
281 	case AF_INET6: {
282 		struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
283 		return !ipv6_addr_any(sa);
284 	}
285 	}
286 
287 	dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
288 	return 0;
289 }
290 
291 #ifdef CONFIG_NFS_DISABLE_UDP_SUPPORT
292 static bool nfs_server_transport_udp_invalid(const struct nfs_fs_context *ctx)
293 {
294 	return true;
295 }
296 #else
297 static bool nfs_server_transport_udp_invalid(const struct nfs_fs_context *ctx)
298 {
299 	if (ctx->version == 4)
300 		return true;
301 	return false;
302 }
303 #endif
304 
305 /*
306  * Sanity check the NFS transport protocol.
307  */
308 static int nfs_validate_transport_protocol(struct fs_context *fc,
309 					   struct nfs_fs_context *ctx)
310 {
311 	switch (ctx->nfs_server.protocol) {
312 	case XPRT_TRANSPORT_UDP:
313 		if (nfs_server_transport_udp_invalid(ctx))
314 			goto out_invalid_transport_udp;
315 		break;
316 	case XPRT_TRANSPORT_TCP:
317 	case XPRT_TRANSPORT_RDMA:
318 		break;
319 	default:
320 		ctx->nfs_server.protocol = XPRT_TRANSPORT_TCP;
321 	}
322 	return 0;
323 out_invalid_transport_udp:
324 	return nfs_invalf(fc, "NFS: Unsupported transport protocol udp");
325 }
326 
327 /*
328  * For text based NFSv2/v3 mounts, the mount protocol transport default
329  * settings should depend upon the specified NFS transport.
330  */
331 static void nfs_set_mount_transport_protocol(struct nfs_fs_context *ctx)
332 {
333 	if (ctx->mount_server.protocol == XPRT_TRANSPORT_UDP ||
334 	    ctx->mount_server.protocol == XPRT_TRANSPORT_TCP)
335 			return;
336 	switch (ctx->nfs_server.protocol) {
337 	case XPRT_TRANSPORT_UDP:
338 		ctx->mount_server.protocol = XPRT_TRANSPORT_UDP;
339 		break;
340 	case XPRT_TRANSPORT_TCP:
341 	case XPRT_TRANSPORT_RDMA:
342 		ctx->mount_server.protocol = XPRT_TRANSPORT_TCP;
343 	}
344 }
345 
346 /*
347  * Add 'flavor' to 'auth_info' if not already present.
348  * Returns true if 'flavor' ends up in the list, false otherwise
349  */
350 static int nfs_auth_info_add(struct fs_context *fc,
351 			     struct nfs_auth_info *auth_info,
352 			     rpc_authflavor_t flavor)
353 {
354 	unsigned int i;
355 	unsigned int max_flavor_len = ARRAY_SIZE(auth_info->flavors);
356 
357 	/* make sure this flavor isn't already in the list */
358 	for (i = 0; i < auth_info->flavor_len; i++) {
359 		if (flavor == auth_info->flavors[i])
360 			return 0;
361 	}
362 
363 	if (auth_info->flavor_len + 1 >= max_flavor_len)
364 		return nfs_invalf(fc, "NFS: too many sec= flavors");
365 
366 	auth_info->flavors[auth_info->flavor_len++] = flavor;
367 	return 0;
368 }
369 
370 /*
371  * Parse the value of the 'sec=' option.
372  */
373 static int nfs_parse_security_flavors(struct fs_context *fc,
374 				      struct fs_parameter *param)
375 {
376 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
377 	rpc_authflavor_t pseudoflavor;
378 	char *string = param->string, *p;
379 	int ret;
380 
381 	dfprintk(MOUNT, "NFS: parsing %s=%s option\n", param->key, param->string);
382 
383 	while ((p = strsep(&string, ":")) != NULL) {
384 		if (!*p)
385 			continue;
386 		switch (lookup_constant(nfs_secflavor_tokens, p, -1)) {
387 		case Opt_sec_none:
388 			pseudoflavor = RPC_AUTH_NULL;
389 			break;
390 		case Opt_sec_sys:
391 			pseudoflavor = RPC_AUTH_UNIX;
392 			break;
393 		case Opt_sec_krb5:
394 			pseudoflavor = RPC_AUTH_GSS_KRB5;
395 			break;
396 		case Opt_sec_krb5i:
397 			pseudoflavor = RPC_AUTH_GSS_KRB5I;
398 			break;
399 		case Opt_sec_krb5p:
400 			pseudoflavor = RPC_AUTH_GSS_KRB5P;
401 			break;
402 		case Opt_sec_lkey:
403 			pseudoflavor = RPC_AUTH_GSS_LKEY;
404 			break;
405 		case Opt_sec_lkeyi:
406 			pseudoflavor = RPC_AUTH_GSS_LKEYI;
407 			break;
408 		case Opt_sec_lkeyp:
409 			pseudoflavor = RPC_AUTH_GSS_LKEYP;
410 			break;
411 		case Opt_sec_spkm:
412 			pseudoflavor = RPC_AUTH_GSS_SPKM;
413 			break;
414 		case Opt_sec_spkmi:
415 			pseudoflavor = RPC_AUTH_GSS_SPKMI;
416 			break;
417 		case Opt_sec_spkmp:
418 			pseudoflavor = RPC_AUTH_GSS_SPKMP;
419 			break;
420 		default:
421 			return nfs_invalf(fc, "NFS: sec=%s option not recognized", p);
422 		}
423 
424 		ret = nfs_auth_info_add(fc, &ctx->auth_info, pseudoflavor);
425 		if (ret < 0)
426 			return ret;
427 	}
428 
429 	return 0;
430 }
431 
432 static int nfs_parse_version_string(struct fs_context *fc,
433 				    const char *string)
434 {
435 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
436 
437 	ctx->flags &= ~NFS_MOUNT_VER3;
438 	switch (lookup_constant(nfs_vers_tokens, string, -1)) {
439 	case Opt_vers_2:
440 		ctx->version = 2;
441 		break;
442 	case Opt_vers_3:
443 		ctx->flags |= NFS_MOUNT_VER3;
444 		ctx->version = 3;
445 		break;
446 	case Opt_vers_4:
447 		/* Backward compatibility option. In future,
448 		 * the mount program should always supply
449 		 * a NFSv4 minor version number.
450 		 */
451 		ctx->version = 4;
452 		break;
453 	case Opt_vers_4_0:
454 		ctx->version = 4;
455 		ctx->minorversion = 0;
456 		break;
457 	case Opt_vers_4_1:
458 		ctx->version = 4;
459 		ctx->minorversion = 1;
460 		break;
461 	case Opt_vers_4_2:
462 		ctx->version = 4;
463 		ctx->minorversion = 2;
464 		break;
465 	default:
466 		return nfs_invalf(fc, "NFS: Unsupported NFS version");
467 	}
468 	return 0;
469 }
470 
471 /*
472  * Parse a single mount parameter.
473  */
474 static int nfs_fs_context_parse_param(struct fs_context *fc,
475 				      struct fs_parameter *param)
476 {
477 	struct fs_parse_result result;
478 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
479 	unsigned short protofamily, mountfamily;
480 	unsigned int len;
481 	int ret, opt;
482 
483 	dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", param->key);
484 
485 	opt = fs_parse(fc, nfs_fs_parameters, param, &result);
486 	if (opt < 0)
487 		return ctx->sloppy ? 1 : opt;
488 
489 	if (fc->security)
490 		ctx->has_sec_mnt_opts = 1;
491 
492 	switch (opt) {
493 	case Opt_source:
494 		if (fc->source)
495 			return nfs_invalf(fc, "NFS: Multiple sources not supported");
496 		fc->source = param->string;
497 		param->string = NULL;
498 		break;
499 
500 		/*
501 		 * boolean options:  foo/nofoo
502 		 */
503 	case Opt_soft:
504 		ctx->flags |= NFS_MOUNT_SOFT;
505 		ctx->flags &= ~NFS_MOUNT_SOFTERR;
506 		break;
507 	case Opt_softerr:
508 		ctx->flags |= NFS_MOUNT_SOFTERR | NFS_MOUNT_SOFTREVAL;
509 		ctx->flags &= ~NFS_MOUNT_SOFT;
510 		break;
511 	case Opt_hard:
512 		ctx->flags &= ~(NFS_MOUNT_SOFT |
513 				NFS_MOUNT_SOFTERR |
514 				NFS_MOUNT_SOFTREVAL);
515 		break;
516 	case Opt_softreval:
517 		if (result.negated)
518 			ctx->flags &= ~NFS_MOUNT_SOFTREVAL;
519 		else
520 			ctx->flags |= NFS_MOUNT_SOFTREVAL;
521 		break;
522 	case Opt_posix:
523 		if (result.negated)
524 			ctx->flags &= ~NFS_MOUNT_POSIX;
525 		else
526 			ctx->flags |= NFS_MOUNT_POSIX;
527 		break;
528 	case Opt_cto:
529 		if (result.negated)
530 			ctx->flags |= NFS_MOUNT_NOCTO;
531 		else
532 			ctx->flags &= ~NFS_MOUNT_NOCTO;
533 		break;
534 	case Opt_trunkdiscovery:
535 		if (result.negated)
536 			ctx->flags &= ~NFS_MOUNT_TRUNK_DISCOVERY;
537 		else
538 			ctx->flags |= NFS_MOUNT_TRUNK_DISCOVERY;
539 		break;
540 	case Opt_ac:
541 		if (result.negated)
542 			ctx->flags |= NFS_MOUNT_NOAC;
543 		else
544 			ctx->flags &= ~NFS_MOUNT_NOAC;
545 		break;
546 	case Opt_lock:
547 		if (result.negated) {
548 			ctx->flags |= NFS_MOUNT_NONLM;
549 			ctx->flags |= (NFS_MOUNT_LOCAL_FLOCK | NFS_MOUNT_LOCAL_FCNTL);
550 		} else {
551 			ctx->flags &= ~NFS_MOUNT_NONLM;
552 			ctx->flags &= ~(NFS_MOUNT_LOCAL_FLOCK | NFS_MOUNT_LOCAL_FCNTL);
553 		}
554 		break;
555 	case Opt_udp:
556 		ctx->flags &= ~NFS_MOUNT_TCP;
557 		ctx->nfs_server.protocol = XPRT_TRANSPORT_UDP;
558 		break;
559 	case Opt_tcp:
560 	case Opt_rdma:
561 		ctx->flags |= NFS_MOUNT_TCP; /* for side protocols */
562 		ret = xprt_find_transport_ident(param->key);
563 		if (ret < 0)
564 			goto out_bad_transport;
565 		ctx->nfs_server.protocol = ret;
566 		break;
567 	case Opt_acl:
568 		if (result.negated)
569 			ctx->flags |= NFS_MOUNT_NOACL;
570 		else
571 			ctx->flags &= ~NFS_MOUNT_NOACL;
572 		break;
573 	case Opt_rdirplus:
574 		if (result.negated)
575 			ctx->flags |= NFS_MOUNT_NORDIRPLUS;
576 		else
577 			ctx->flags &= ~NFS_MOUNT_NORDIRPLUS;
578 		break;
579 	case Opt_sharecache:
580 		if (result.negated)
581 			ctx->flags |= NFS_MOUNT_UNSHARED;
582 		else
583 			ctx->flags &= ~NFS_MOUNT_UNSHARED;
584 		break;
585 	case Opt_resvport:
586 		if (result.negated)
587 			ctx->flags |= NFS_MOUNT_NORESVPORT;
588 		else
589 			ctx->flags &= ~NFS_MOUNT_NORESVPORT;
590 		break;
591 	case Opt_fscache_flag:
592 		if (result.negated)
593 			ctx->options &= ~NFS_OPTION_FSCACHE;
594 		else
595 			ctx->options |= NFS_OPTION_FSCACHE;
596 		kfree(ctx->fscache_uniq);
597 		ctx->fscache_uniq = NULL;
598 		break;
599 	case Opt_fscache:
600 		ctx->options |= NFS_OPTION_FSCACHE;
601 		kfree(ctx->fscache_uniq);
602 		ctx->fscache_uniq = param->string;
603 		param->string = NULL;
604 		break;
605 	case Opt_migration:
606 		if (result.negated)
607 			ctx->options &= ~NFS_OPTION_MIGRATION;
608 		else
609 			ctx->options |= NFS_OPTION_MIGRATION;
610 		break;
611 
612 		/*
613 		 * options that take numeric values
614 		 */
615 	case Opt_port:
616 		if (result.uint_32 > USHRT_MAX)
617 			goto out_of_bounds;
618 		ctx->nfs_server.port = result.uint_32;
619 		break;
620 	case Opt_rsize:
621 		ctx->rsize = result.uint_32;
622 		break;
623 	case Opt_wsize:
624 		ctx->wsize = result.uint_32;
625 		break;
626 	case Opt_bsize:
627 		ctx->bsize = result.uint_32;
628 		break;
629 	case Opt_timeo:
630 		if (result.uint_32 < 1 || result.uint_32 > INT_MAX)
631 			goto out_of_bounds;
632 		ctx->timeo = result.uint_32;
633 		break;
634 	case Opt_retrans:
635 		if (result.uint_32 > INT_MAX)
636 			goto out_of_bounds;
637 		ctx->retrans = result.uint_32;
638 		break;
639 	case Opt_acregmin:
640 		ctx->acregmin = result.uint_32;
641 		break;
642 	case Opt_acregmax:
643 		ctx->acregmax = result.uint_32;
644 		break;
645 	case Opt_acdirmin:
646 		ctx->acdirmin = result.uint_32;
647 		break;
648 	case Opt_acdirmax:
649 		ctx->acdirmax = result.uint_32;
650 		break;
651 	case Opt_actimeo:
652 		ctx->acregmin = result.uint_32;
653 		ctx->acregmax = result.uint_32;
654 		ctx->acdirmin = result.uint_32;
655 		ctx->acdirmax = result.uint_32;
656 		break;
657 	case Opt_namelen:
658 		ctx->namlen = result.uint_32;
659 		break;
660 	case Opt_mountport:
661 		if (result.uint_32 > USHRT_MAX)
662 			goto out_of_bounds;
663 		ctx->mount_server.port = result.uint_32;
664 		break;
665 	case Opt_mountvers:
666 		if (result.uint_32 < NFS_MNT_VERSION ||
667 		    result.uint_32 > NFS_MNT3_VERSION)
668 			goto out_of_bounds;
669 		ctx->mount_server.version = result.uint_32;
670 		break;
671 	case Opt_minorversion:
672 		if (result.uint_32 > NFS4_MAX_MINOR_VERSION)
673 			goto out_of_bounds;
674 		ctx->minorversion = result.uint_32;
675 		break;
676 
677 		/*
678 		 * options that take text values
679 		 */
680 	case Opt_v:
681 		ret = nfs_parse_version_string(fc, param->key + 1);
682 		if (ret < 0)
683 			return ret;
684 		break;
685 	case Opt_vers:
686 		ret = nfs_parse_version_string(fc, param->string);
687 		if (ret < 0)
688 			return ret;
689 		break;
690 	case Opt_sec:
691 		ret = nfs_parse_security_flavors(fc, param);
692 		if (ret < 0)
693 			return ret;
694 		break;
695 
696 	case Opt_proto:
697 		protofamily = AF_INET;
698 		switch (lookup_constant(nfs_xprt_protocol_tokens, param->string, -1)) {
699 		case Opt_xprt_udp6:
700 			protofamily = AF_INET6;
701 			fallthrough;
702 		case Opt_xprt_udp:
703 			ctx->flags &= ~NFS_MOUNT_TCP;
704 			ctx->nfs_server.protocol = XPRT_TRANSPORT_UDP;
705 			break;
706 		case Opt_xprt_tcp6:
707 			protofamily = AF_INET6;
708 			fallthrough;
709 		case Opt_xprt_tcp:
710 			ctx->flags |= NFS_MOUNT_TCP;
711 			ctx->nfs_server.protocol = XPRT_TRANSPORT_TCP;
712 			break;
713 		case Opt_xprt_rdma6:
714 			protofamily = AF_INET6;
715 			fallthrough;
716 		case Opt_xprt_rdma:
717 			/* vector side protocols to TCP */
718 			ctx->flags |= NFS_MOUNT_TCP;
719 			ret = xprt_find_transport_ident(param->string);
720 			if (ret < 0)
721 				goto out_bad_transport;
722 			ctx->nfs_server.protocol = ret;
723 			break;
724 		default:
725 			goto out_bad_transport;
726 		}
727 
728 		ctx->protofamily = protofamily;
729 		break;
730 
731 	case Opt_mountproto:
732 		mountfamily = AF_INET;
733 		switch (lookup_constant(nfs_xprt_protocol_tokens, param->string, -1)) {
734 		case Opt_xprt_udp6:
735 			mountfamily = AF_INET6;
736 			fallthrough;
737 		case Opt_xprt_udp:
738 			ctx->mount_server.protocol = XPRT_TRANSPORT_UDP;
739 			break;
740 		case Opt_xprt_tcp6:
741 			mountfamily = AF_INET6;
742 			fallthrough;
743 		case Opt_xprt_tcp:
744 			ctx->mount_server.protocol = XPRT_TRANSPORT_TCP;
745 			break;
746 		case Opt_xprt_rdma: /* not used for side protocols */
747 		default:
748 			goto out_bad_transport;
749 		}
750 		ctx->mountfamily = mountfamily;
751 		break;
752 
753 	case Opt_addr:
754 		len = rpc_pton(fc->net_ns, param->string, param->size,
755 			       &ctx->nfs_server.address,
756 			       sizeof(ctx->nfs_server._address));
757 		if (len == 0)
758 			goto out_invalid_address;
759 		ctx->nfs_server.addrlen = len;
760 		break;
761 	case Opt_clientaddr:
762 		kfree(ctx->client_address);
763 		ctx->client_address = param->string;
764 		param->string = NULL;
765 		break;
766 	case Opt_mounthost:
767 		kfree(ctx->mount_server.hostname);
768 		ctx->mount_server.hostname = param->string;
769 		param->string = NULL;
770 		break;
771 	case Opt_mountaddr:
772 		len = rpc_pton(fc->net_ns, param->string, param->size,
773 			       &ctx->mount_server.address,
774 			       sizeof(ctx->mount_server._address));
775 		if (len == 0)
776 			goto out_invalid_address;
777 		ctx->mount_server.addrlen = len;
778 		break;
779 	case Opt_nconnect:
780 		if (result.uint_32 < 1 || result.uint_32 > NFS_MAX_CONNECTIONS)
781 			goto out_of_bounds;
782 		ctx->nfs_server.nconnect = result.uint_32;
783 		break;
784 	case Opt_max_connect:
785 		if (result.uint_32 < 1 || result.uint_32 > NFS_MAX_TRANSPORTS)
786 			goto out_of_bounds;
787 		ctx->nfs_server.max_connect = result.uint_32;
788 		break;
789 	case Opt_lookupcache:
790 		switch (result.uint_32) {
791 		case Opt_lookupcache_all:
792 			ctx->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
793 			break;
794 		case Opt_lookupcache_positive:
795 			ctx->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
796 			ctx->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
797 			break;
798 		case Opt_lookupcache_none:
799 			ctx->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
800 			break;
801 		default:
802 			goto out_invalid_value;
803 		}
804 		break;
805 	case Opt_local_lock:
806 		switch (result.uint_32) {
807 		case Opt_local_lock_all:
808 			ctx->flags |= (NFS_MOUNT_LOCAL_FLOCK |
809 				       NFS_MOUNT_LOCAL_FCNTL);
810 			break;
811 		case Opt_local_lock_flock:
812 			ctx->flags |= NFS_MOUNT_LOCAL_FLOCK;
813 			break;
814 		case Opt_local_lock_posix:
815 			ctx->flags |= NFS_MOUNT_LOCAL_FCNTL;
816 			break;
817 		case Opt_local_lock_none:
818 			ctx->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
819 					NFS_MOUNT_LOCAL_FCNTL);
820 			break;
821 		default:
822 			goto out_invalid_value;
823 		}
824 		break;
825 	case Opt_write:
826 		switch (result.uint_32) {
827 		case Opt_write_lazy:
828 			ctx->flags &=
829 				~(NFS_MOUNT_WRITE_EAGER | NFS_MOUNT_WRITE_WAIT);
830 			break;
831 		case Opt_write_eager:
832 			ctx->flags |= NFS_MOUNT_WRITE_EAGER;
833 			ctx->flags &= ~NFS_MOUNT_WRITE_WAIT;
834 			break;
835 		case Opt_write_wait:
836 			ctx->flags |=
837 				NFS_MOUNT_WRITE_EAGER | NFS_MOUNT_WRITE_WAIT;
838 			break;
839 		default:
840 			goto out_invalid_value;
841 		}
842 		break;
843 
844 		/*
845 		 * Special options
846 		 */
847 	case Opt_sloppy:
848 		ctx->sloppy = true;
849 		dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
850 		break;
851 	}
852 
853 	return 0;
854 
855 out_invalid_value:
856 	return nfs_invalf(fc, "NFS: Bad mount option value specified");
857 out_invalid_address:
858 	return nfs_invalf(fc, "NFS: Bad IP address specified");
859 out_of_bounds:
860 	return nfs_invalf(fc, "NFS: Value for '%s' out of range", param->key);
861 out_bad_transport:
862 	return nfs_invalf(fc, "NFS: Unrecognized transport protocol");
863 }
864 
865 /*
866  * Split fc->source into "hostname:export_path".
867  *
868  * The leftmost colon demarks the split between the server's hostname
869  * and the export path.  If the hostname starts with a left square
870  * bracket, then it may contain colons.
871  *
872  * Note: caller frees hostname and export path, even on error.
873  */
874 static int nfs_parse_source(struct fs_context *fc,
875 			    size_t maxnamlen, size_t maxpathlen)
876 {
877 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
878 	const char *dev_name = fc->source;
879 	size_t len;
880 	const char *end;
881 
882 	if (unlikely(!dev_name || !*dev_name)) {
883 		dfprintk(MOUNT, "NFS: device name not specified\n");
884 		return -EINVAL;
885 	}
886 
887 	/* Is the host name protected with square brakcets? */
888 	if (*dev_name == '[') {
889 		end = strchr(++dev_name, ']');
890 		if (end == NULL || end[1] != ':')
891 			goto out_bad_devname;
892 
893 		len = end - dev_name;
894 		end++;
895 	} else {
896 		const char *comma;
897 
898 		end = strchr(dev_name, ':');
899 		if (end == NULL)
900 			goto out_bad_devname;
901 		len = end - dev_name;
902 
903 		/* kill possible hostname list: not supported */
904 		comma = memchr(dev_name, ',', len);
905 		if (comma)
906 			len = comma - dev_name;
907 	}
908 
909 	if (len > maxnamlen)
910 		goto out_hostname;
911 
912 	kfree(ctx->nfs_server.hostname);
913 
914 	/* N.B. caller will free nfs_server.hostname in all cases */
915 	ctx->nfs_server.hostname = kmemdup_nul(dev_name, len, GFP_KERNEL);
916 	if (!ctx->nfs_server.hostname)
917 		goto out_nomem;
918 	len = strlen(++end);
919 	if (len > maxpathlen)
920 		goto out_path;
921 	ctx->nfs_server.export_path = kmemdup_nul(end, len, GFP_KERNEL);
922 	if (!ctx->nfs_server.export_path)
923 		goto out_nomem;
924 
925 	dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", ctx->nfs_server.export_path);
926 	return 0;
927 
928 out_bad_devname:
929 	return nfs_invalf(fc, "NFS: device name not in host:path format");
930 out_nomem:
931 	nfs_errorf(fc, "NFS: not enough memory to parse device name");
932 	return -ENOMEM;
933 out_hostname:
934 	nfs_errorf(fc, "NFS: server hostname too long");
935 	return -ENAMETOOLONG;
936 out_path:
937 	nfs_errorf(fc, "NFS: export pathname too long");
938 	return -ENAMETOOLONG;
939 }
940 
941 static inline bool is_remount_fc(struct fs_context *fc)
942 {
943 	return fc->root != NULL;
944 }
945 
946 /*
947  * Parse monolithic NFS2/NFS3 mount data
948  * - fills in the mount root filehandle
949  *
950  * For option strings, user space handles the following behaviors:
951  *
952  * + DNS: mapping server host name to IP address ("addr=" option)
953  *
954  * + failure mode: how to behave if a mount request can't be handled
955  *   immediately ("fg/bg" option)
956  *
957  * + retry: how often to retry a mount request ("retry=" option)
958  *
959  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
960  *   mountproto=tcp after mountproto=udp, and so on
961  */
962 static int nfs23_parse_monolithic(struct fs_context *fc,
963 				  struct nfs_mount_data *data)
964 {
965 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
966 	struct nfs_fh *mntfh = ctx->mntfh;
967 	struct sockaddr *sap = (struct sockaddr *)&ctx->nfs_server.address;
968 	int extra_flags = NFS_MOUNT_LEGACY_INTERFACE;
969 	int ret;
970 
971 	if (data == NULL)
972 		goto out_no_data;
973 
974 	ctx->version = NFS_DEFAULT_VERSION;
975 	switch (data->version) {
976 	case 1:
977 		data->namlen = 0;
978 		fallthrough;
979 	case 2:
980 		data->bsize = 0;
981 		fallthrough;
982 	case 3:
983 		if (data->flags & NFS_MOUNT_VER3)
984 			goto out_no_v3;
985 		data->root.size = NFS2_FHSIZE;
986 		memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
987 		/* Turn off security negotiation */
988 		extra_flags |= NFS_MOUNT_SECFLAVOUR;
989 		fallthrough;
990 	case 4:
991 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
992 			goto out_no_sec;
993 		fallthrough;
994 	case 5:
995 		memset(data->context, 0, sizeof(data->context));
996 		fallthrough;
997 	case 6:
998 		if (data->flags & NFS_MOUNT_VER3) {
999 			if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1000 				goto out_invalid_fh;
1001 			mntfh->size = data->root.size;
1002 			ctx->version = 3;
1003 		} else {
1004 			mntfh->size = NFS2_FHSIZE;
1005 			ctx->version = 2;
1006 		}
1007 
1008 
1009 		memcpy(mntfh->data, data->root.data, mntfh->size);
1010 		if (mntfh->size < sizeof(mntfh->data))
1011 			memset(mntfh->data + mntfh->size, 0,
1012 			       sizeof(mntfh->data) - mntfh->size);
1013 
1014 		/*
1015 		 * for proto == XPRT_TRANSPORT_UDP, which is what uses
1016 		 * to_exponential, implying shift: limit the shift value
1017 		 * to BITS_PER_LONG (majortimeo is unsigned long)
1018 		 */
1019 		if (!(data->flags & NFS_MOUNT_TCP)) /* this will be UDP */
1020 			if (data->retrans >= 64) /* shift value is too large */
1021 				goto out_invalid_data;
1022 
1023 		/*
1024 		 * Translate to nfs_fs_context, which nfs_fill_super
1025 		 * can deal with.
1026 		 */
1027 		ctx->flags	= data->flags & NFS_MOUNT_FLAGMASK;
1028 		ctx->flags	|= extra_flags;
1029 		ctx->rsize	= data->rsize;
1030 		ctx->wsize	= data->wsize;
1031 		ctx->timeo	= data->timeo;
1032 		ctx->retrans	= data->retrans;
1033 		ctx->acregmin	= data->acregmin;
1034 		ctx->acregmax	= data->acregmax;
1035 		ctx->acdirmin	= data->acdirmin;
1036 		ctx->acdirmax	= data->acdirmax;
1037 		ctx->need_mount	= false;
1038 
1039 		memcpy(sap, &data->addr, sizeof(data->addr));
1040 		ctx->nfs_server.addrlen = sizeof(data->addr);
1041 		ctx->nfs_server.port = ntohs(data->addr.sin_port);
1042 		if (sap->sa_family != AF_INET ||
1043 		    !nfs_verify_server_address(sap))
1044 			goto out_no_address;
1045 
1046 		if (!(data->flags & NFS_MOUNT_TCP))
1047 			ctx->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1048 		/* N.B. caller will free nfs_server.hostname in all cases */
1049 		ctx->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1050 		if (!ctx->nfs_server.hostname)
1051 			goto out_nomem;
1052 
1053 		ctx->namlen		= data->namlen;
1054 		ctx->bsize		= data->bsize;
1055 
1056 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
1057 			ctx->selected_flavor = data->pseudoflavor;
1058 		else
1059 			ctx->selected_flavor = RPC_AUTH_UNIX;
1060 
1061 		if (!(data->flags & NFS_MOUNT_NONLM))
1062 			ctx->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
1063 					 NFS_MOUNT_LOCAL_FCNTL);
1064 		else
1065 			ctx->flags |= (NFS_MOUNT_LOCAL_FLOCK|
1066 					NFS_MOUNT_LOCAL_FCNTL);
1067 
1068 		/*
1069 		 * The legacy version 6 binary mount data from userspace has a
1070 		 * field used only to transport selinux information into the
1071 		 * kernel.  To continue to support that functionality we
1072 		 * have a touch of selinux knowledge here in the NFS code. The
1073 		 * userspace code converted context=blah to just blah so we are
1074 		 * converting back to the full string selinux understands.
1075 		 */
1076 		if (data->context[0]){
1077 #ifdef CONFIG_SECURITY_SELINUX
1078 			int ret;
1079 
1080 			data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1081 			ret = vfs_parse_fs_string(fc, "context",
1082 						  data->context, strlen(data->context));
1083 			if (ret < 0)
1084 				return ret;
1085 #else
1086 			return -EINVAL;
1087 #endif
1088 		}
1089 
1090 		break;
1091 	default:
1092 		goto generic;
1093 	}
1094 
1095 	ret = nfs_validate_transport_protocol(fc, ctx);
1096 	if (ret)
1097 		return ret;
1098 
1099 	ctx->skip_reconfig_option_check = true;
1100 	return 0;
1101 
1102 generic:
1103 	return generic_parse_monolithic(fc, data);
1104 
1105 out_no_data:
1106 	if (is_remount_fc(fc)) {
1107 		ctx->skip_reconfig_option_check = true;
1108 		return 0;
1109 	}
1110 	return nfs_invalf(fc, "NFS: mount program didn't pass any mount data");
1111 
1112 out_no_v3:
1113 	return nfs_invalf(fc, "NFS: nfs_mount_data version does not support v3");
1114 
1115 out_no_sec:
1116 	return nfs_invalf(fc, "NFS: nfs_mount_data version supports only AUTH_SYS");
1117 
1118 out_nomem:
1119 	dfprintk(MOUNT, "NFS: not enough memory to handle mount options");
1120 	return -ENOMEM;
1121 
1122 out_no_address:
1123 	return nfs_invalf(fc, "NFS: mount program didn't pass remote address");
1124 
1125 out_invalid_fh:
1126 	return nfs_invalf(fc, "NFS: invalid root filehandle");
1127 
1128 out_invalid_data:
1129 	return nfs_invalf(fc, "NFS: invalid binary mount data");
1130 }
1131 
1132 #if IS_ENABLED(CONFIG_NFS_V4)
1133 struct compat_nfs_string {
1134 	compat_uint_t len;
1135 	compat_uptr_t data;
1136 };
1137 
1138 static inline void compat_nfs_string(struct nfs_string *dst,
1139 				     struct compat_nfs_string *src)
1140 {
1141 	dst->data = compat_ptr(src->data);
1142 	dst->len = src->len;
1143 }
1144 
1145 struct compat_nfs4_mount_data_v1 {
1146 	compat_int_t version;
1147 	compat_int_t flags;
1148 	compat_int_t rsize;
1149 	compat_int_t wsize;
1150 	compat_int_t timeo;
1151 	compat_int_t retrans;
1152 	compat_int_t acregmin;
1153 	compat_int_t acregmax;
1154 	compat_int_t acdirmin;
1155 	compat_int_t acdirmax;
1156 	struct compat_nfs_string client_addr;
1157 	struct compat_nfs_string mnt_path;
1158 	struct compat_nfs_string hostname;
1159 	compat_uint_t host_addrlen;
1160 	compat_uptr_t host_addr;
1161 	compat_int_t proto;
1162 	compat_int_t auth_flavourlen;
1163 	compat_uptr_t auth_flavours;
1164 };
1165 
1166 static void nfs4_compat_mount_data_conv(struct nfs4_mount_data *data)
1167 {
1168 	struct compat_nfs4_mount_data_v1 *compat =
1169 			(struct compat_nfs4_mount_data_v1 *)data;
1170 
1171 	/* copy the fields backwards */
1172 	data->auth_flavours = compat_ptr(compat->auth_flavours);
1173 	data->auth_flavourlen = compat->auth_flavourlen;
1174 	data->proto = compat->proto;
1175 	data->host_addr = compat_ptr(compat->host_addr);
1176 	data->host_addrlen = compat->host_addrlen;
1177 	compat_nfs_string(&data->hostname, &compat->hostname);
1178 	compat_nfs_string(&data->mnt_path, &compat->mnt_path);
1179 	compat_nfs_string(&data->client_addr, &compat->client_addr);
1180 	data->acdirmax = compat->acdirmax;
1181 	data->acdirmin = compat->acdirmin;
1182 	data->acregmax = compat->acregmax;
1183 	data->acregmin = compat->acregmin;
1184 	data->retrans = compat->retrans;
1185 	data->timeo = compat->timeo;
1186 	data->wsize = compat->wsize;
1187 	data->rsize = compat->rsize;
1188 	data->flags = compat->flags;
1189 	data->version = compat->version;
1190 }
1191 
1192 /*
1193  * Validate NFSv4 mount options
1194  */
1195 static int nfs4_parse_monolithic(struct fs_context *fc,
1196 				 struct nfs4_mount_data *data)
1197 {
1198 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
1199 	struct sockaddr *sap = (struct sockaddr *)&ctx->nfs_server.address;
1200 	int ret;
1201 	char *c;
1202 
1203 	if (!data) {
1204 		if (is_remount_fc(fc))
1205 			goto done;
1206 		return nfs_invalf(fc,
1207 			"NFS4: mount program didn't pass any mount data");
1208 	}
1209 
1210 	ctx->version = 4;
1211 
1212 	if (data->version != 1)
1213 		return generic_parse_monolithic(fc, data);
1214 
1215 	if (in_compat_syscall())
1216 		nfs4_compat_mount_data_conv(data);
1217 
1218 	if (data->host_addrlen > sizeof(ctx->nfs_server.address))
1219 		goto out_no_address;
1220 	if (data->host_addrlen == 0)
1221 		goto out_no_address;
1222 	ctx->nfs_server.addrlen = data->host_addrlen;
1223 	if (copy_from_user(sap, data->host_addr, data->host_addrlen))
1224 		return -EFAULT;
1225 	if (!nfs_verify_server_address(sap))
1226 		goto out_no_address;
1227 	ctx->nfs_server.port = ntohs(((struct sockaddr_in *)sap)->sin_port);
1228 
1229 	if (data->auth_flavourlen) {
1230 		rpc_authflavor_t pseudoflavor;
1231 
1232 		if (data->auth_flavourlen > 1)
1233 			goto out_inval_auth;
1234 		if (copy_from_user(&pseudoflavor, data->auth_flavours,
1235 				   sizeof(pseudoflavor)))
1236 			return -EFAULT;
1237 		ctx->selected_flavor = pseudoflavor;
1238 	} else {
1239 		ctx->selected_flavor = RPC_AUTH_UNIX;
1240 	}
1241 
1242 	c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
1243 	if (IS_ERR(c))
1244 		return PTR_ERR(c);
1245 	ctx->nfs_server.hostname = c;
1246 
1247 	c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
1248 	if (IS_ERR(c))
1249 		return PTR_ERR(c);
1250 	ctx->nfs_server.export_path = c;
1251 	dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
1252 
1253 	c = strndup_user(data->client_addr.data, 16);
1254 	if (IS_ERR(c))
1255 		return PTR_ERR(c);
1256 	ctx->client_address = c;
1257 
1258 	/*
1259 	 * Translate to nfs_fs_context, which nfs_fill_super
1260 	 * can deal with.
1261 	 */
1262 
1263 	ctx->flags	= data->flags & NFS4_MOUNT_FLAGMASK;
1264 	ctx->rsize	= data->rsize;
1265 	ctx->wsize	= data->wsize;
1266 	ctx->timeo	= data->timeo;
1267 	ctx->retrans	= data->retrans;
1268 	ctx->acregmin	= data->acregmin;
1269 	ctx->acregmax	= data->acregmax;
1270 	ctx->acdirmin	= data->acdirmin;
1271 	ctx->acdirmax	= data->acdirmax;
1272 	ctx->nfs_server.protocol = data->proto;
1273 	ret = nfs_validate_transport_protocol(fc, ctx);
1274 	if (ret)
1275 		return ret;
1276 done:
1277 	ctx->skip_reconfig_option_check = true;
1278 	return 0;
1279 
1280 out_inval_auth:
1281 	return nfs_invalf(fc, "NFS4: Invalid number of RPC auth flavours %d",
1282 		      data->auth_flavourlen);
1283 
1284 out_no_address:
1285 	return nfs_invalf(fc, "NFS4: mount program didn't pass remote address");
1286 }
1287 #endif
1288 
1289 /*
1290  * Parse a monolithic block of data from sys_mount().
1291  */
1292 static int nfs_fs_context_parse_monolithic(struct fs_context *fc,
1293 					   void *data)
1294 {
1295 	if (fc->fs_type == &nfs_fs_type)
1296 		return nfs23_parse_monolithic(fc, data);
1297 
1298 #if IS_ENABLED(CONFIG_NFS_V4)
1299 	if (fc->fs_type == &nfs4_fs_type)
1300 		return nfs4_parse_monolithic(fc, data);
1301 #endif
1302 
1303 	return nfs_invalf(fc, "NFS: Unsupported monolithic data version");
1304 }
1305 
1306 /*
1307  * Validate the preparsed information in the config.
1308  */
1309 static int nfs_fs_context_validate(struct fs_context *fc)
1310 {
1311 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
1312 	struct nfs_subversion *nfs_mod;
1313 	struct sockaddr *sap = (struct sockaddr *)&ctx->nfs_server.address;
1314 	int max_namelen = PAGE_SIZE;
1315 	int max_pathlen = NFS_MAXPATHLEN;
1316 	int port = 0;
1317 	int ret;
1318 
1319 	if (!fc->source)
1320 		goto out_no_device_name;
1321 
1322 	/* Check for sanity first. */
1323 	if (ctx->minorversion && ctx->version != 4)
1324 		goto out_minorversion_mismatch;
1325 
1326 	if (ctx->options & NFS_OPTION_MIGRATION &&
1327 	    (ctx->version != 4 || ctx->minorversion != 0))
1328 		goto out_migration_misuse;
1329 
1330 	/* Verify that any proto=/mountproto= options match the address
1331 	 * families in the addr=/mountaddr= options.
1332 	 */
1333 	if (ctx->protofamily != AF_UNSPEC &&
1334 	    ctx->protofamily != ctx->nfs_server.address.sa_family)
1335 		goto out_proto_mismatch;
1336 
1337 	if (ctx->mountfamily != AF_UNSPEC) {
1338 		if (ctx->mount_server.addrlen) {
1339 			if (ctx->mountfamily != ctx->mount_server.address.sa_family)
1340 				goto out_mountproto_mismatch;
1341 		} else {
1342 			if (ctx->mountfamily != ctx->nfs_server.address.sa_family)
1343 				goto out_mountproto_mismatch;
1344 		}
1345 	}
1346 
1347 	if (!nfs_verify_server_address(sap))
1348 		goto out_no_address;
1349 
1350 	ret = nfs_validate_transport_protocol(fc, ctx);
1351 	if (ret)
1352 		return ret;
1353 
1354 	if (ctx->version == 4) {
1355 		if (IS_ENABLED(CONFIG_NFS_V4)) {
1356 			if (ctx->nfs_server.protocol == XPRT_TRANSPORT_RDMA)
1357 				port = NFS_RDMA_PORT;
1358 			else
1359 				port = NFS_PORT;
1360 			max_namelen = NFS4_MAXNAMLEN;
1361 			max_pathlen = NFS4_MAXPATHLEN;
1362 			ctx->flags &= ~(NFS_MOUNT_NONLM | NFS_MOUNT_NOACL |
1363 					NFS_MOUNT_VER3 | NFS_MOUNT_LOCAL_FLOCK |
1364 					NFS_MOUNT_LOCAL_FCNTL);
1365 		} else {
1366 			goto out_v4_not_compiled;
1367 		}
1368 	} else {
1369 		nfs_set_mount_transport_protocol(ctx);
1370 		if (ctx->nfs_server.protocol == XPRT_TRANSPORT_RDMA)
1371 			port = NFS_RDMA_PORT;
1372 	}
1373 
1374 	nfs_set_port(sap, &ctx->nfs_server.port, port);
1375 
1376 	ret = nfs_parse_source(fc, max_namelen, max_pathlen);
1377 	if (ret < 0)
1378 		return ret;
1379 
1380 	/* Load the NFS protocol module if we haven't done so yet */
1381 	if (!ctx->nfs_mod) {
1382 		nfs_mod = get_nfs_version(ctx->version);
1383 		if (IS_ERR(nfs_mod)) {
1384 			ret = PTR_ERR(nfs_mod);
1385 			goto out_version_unavailable;
1386 		}
1387 		ctx->nfs_mod = nfs_mod;
1388 	}
1389 
1390 	/* Ensure the filesystem context has the correct fs_type */
1391 	if (fc->fs_type != ctx->nfs_mod->nfs_fs) {
1392 		module_put(fc->fs_type->owner);
1393 		__module_get(ctx->nfs_mod->nfs_fs->owner);
1394 		fc->fs_type = ctx->nfs_mod->nfs_fs;
1395 	}
1396 	return 0;
1397 
1398 out_no_device_name:
1399 	return nfs_invalf(fc, "NFS: Device name not specified");
1400 out_v4_not_compiled:
1401 	nfs_errorf(fc, "NFS: NFSv4 is not compiled into kernel");
1402 	return -EPROTONOSUPPORT;
1403 out_no_address:
1404 	return nfs_invalf(fc, "NFS: mount program didn't pass remote address");
1405 out_mountproto_mismatch:
1406 	return nfs_invalf(fc, "NFS: Mount server address does not match mountproto= option");
1407 out_proto_mismatch:
1408 	return nfs_invalf(fc, "NFS: Server address does not match proto= option");
1409 out_minorversion_mismatch:
1410 	return nfs_invalf(fc, "NFS: Mount option vers=%u does not support minorversion=%u",
1411 			  ctx->version, ctx->minorversion);
1412 out_migration_misuse:
1413 	return nfs_invalf(fc, "NFS: 'Migration' not supported for this NFS version");
1414 out_version_unavailable:
1415 	nfs_errorf(fc, "NFS: Version unavailable");
1416 	return ret;
1417 }
1418 
1419 /*
1420  * Create an NFS superblock by the appropriate method.
1421  */
1422 static int nfs_get_tree(struct fs_context *fc)
1423 {
1424 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
1425 	int err = nfs_fs_context_validate(fc);
1426 
1427 	if (err)
1428 		return err;
1429 	if (!ctx->internal)
1430 		return ctx->nfs_mod->rpc_ops->try_get_tree(fc);
1431 	else
1432 		return nfs_get_tree_common(fc);
1433 }
1434 
1435 /*
1436  * Handle duplication of a configuration.  The caller copied *src into *sc, but
1437  * it can't deal with resource pointers in the filesystem context, so we have
1438  * to do that.  We need to clear pointers, copy data or get extra refs as
1439  * appropriate.
1440  */
1441 static int nfs_fs_context_dup(struct fs_context *fc, struct fs_context *src_fc)
1442 {
1443 	struct nfs_fs_context *src = nfs_fc2context(src_fc), *ctx;
1444 
1445 	ctx = kmemdup(src, sizeof(struct nfs_fs_context), GFP_KERNEL);
1446 	if (!ctx)
1447 		return -ENOMEM;
1448 
1449 	ctx->mntfh = nfs_alloc_fhandle();
1450 	if (!ctx->mntfh) {
1451 		kfree(ctx);
1452 		return -ENOMEM;
1453 	}
1454 	nfs_copy_fh(ctx->mntfh, src->mntfh);
1455 
1456 	__module_get(ctx->nfs_mod->owner);
1457 	ctx->client_address		= NULL;
1458 	ctx->mount_server.hostname	= NULL;
1459 	ctx->nfs_server.export_path	= NULL;
1460 	ctx->nfs_server.hostname	= NULL;
1461 	ctx->fscache_uniq		= NULL;
1462 	ctx->clone_data.fattr		= NULL;
1463 	fc->fs_private = ctx;
1464 	return 0;
1465 }
1466 
1467 static void nfs_fs_context_free(struct fs_context *fc)
1468 {
1469 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
1470 
1471 	if (ctx) {
1472 		if (ctx->server)
1473 			nfs_free_server(ctx->server);
1474 		if (ctx->nfs_mod)
1475 			put_nfs_version(ctx->nfs_mod);
1476 		kfree(ctx->client_address);
1477 		kfree(ctx->mount_server.hostname);
1478 		kfree(ctx->nfs_server.export_path);
1479 		kfree(ctx->nfs_server.hostname);
1480 		kfree(ctx->fscache_uniq);
1481 		nfs_free_fhandle(ctx->mntfh);
1482 		nfs_free_fattr(ctx->clone_data.fattr);
1483 		kfree(ctx);
1484 	}
1485 }
1486 
1487 static const struct fs_context_operations nfs_fs_context_ops = {
1488 	.free			= nfs_fs_context_free,
1489 	.dup			= nfs_fs_context_dup,
1490 	.parse_param		= nfs_fs_context_parse_param,
1491 	.parse_monolithic	= nfs_fs_context_parse_monolithic,
1492 	.get_tree		= nfs_get_tree,
1493 	.reconfigure		= nfs_reconfigure,
1494 };
1495 
1496 /*
1497  * Prepare superblock configuration.  We use the namespaces attached to the
1498  * context.  This may be the current process's namespaces, or it may be a
1499  * container's namespaces.
1500  */
1501 static int nfs_init_fs_context(struct fs_context *fc)
1502 {
1503 	struct nfs_fs_context *ctx;
1504 
1505 	ctx = kzalloc(sizeof(struct nfs_fs_context), GFP_KERNEL);
1506 	if (unlikely(!ctx))
1507 		return -ENOMEM;
1508 
1509 	ctx->mntfh = nfs_alloc_fhandle();
1510 	if (unlikely(!ctx->mntfh)) {
1511 		kfree(ctx);
1512 		return -ENOMEM;
1513 	}
1514 
1515 	ctx->protofamily	= AF_UNSPEC;
1516 	ctx->mountfamily	= AF_UNSPEC;
1517 	ctx->mount_server.port	= NFS_UNSPEC_PORT;
1518 
1519 	if (fc->root) {
1520 		/* reconfigure, start with the current config */
1521 		struct nfs_server *nfss = fc->root->d_sb->s_fs_info;
1522 		struct net *net = nfss->nfs_client->cl_net;
1523 
1524 		ctx->flags		= nfss->flags;
1525 		ctx->rsize		= nfss->rsize;
1526 		ctx->wsize		= nfss->wsize;
1527 		ctx->retrans		= nfss->client->cl_timeout->to_retries;
1528 		ctx->selected_flavor	= nfss->client->cl_auth->au_flavor;
1529 		ctx->acregmin		= nfss->acregmin / HZ;
1530 		ctx->acregmax		= nfss->acregmax / HZ;
1531 		ctx->acdirmin		= nfss->acdirmin / HZ;
1532 		ctx->acdirmax		= nfss->acdirmax / HZ;
1533 		ctx->timeo		= 10U * nfss->client->cl_timeout->to_initval / HZ;
1534 		ctx->nfs_server.port	= nfss->port;
1535 		ctx->nfs_server.addrlen	= nfss->nfs_client->cl_addrlen;
1536 		ctx->version		= nfss->nfs_client->rpc_ops->version;
1537 		ctx->minorversion	= nfss->nfs_client->cl_minorversion;
1538 
1539 		memcpy(&ctx->nfs_server.address, &nfss->nfs_client->cl_addr,
1540 			ctx->nfs_server.addrlen);
1541 
1542 		if (fc->net_ns != net) {
1543 			put_net(fc->net_ns);
1544 			fc->net_ns = get_net(net);
1545 		}
1546 
1547 		ctx->nfs_mod = nfss->nfs_client->cl_nfs_mod;
1548 		__module_get(ctx->nfs_mod->owner);
1549 	} else {
1550 		/* defaults */
1551 		ctx->timeo		= NFS_UNSPEC_TIMEO;
1552 		ctx->retrans		= NFS_UNSPEC_RETRANS;
1553 		ctx->acregmin		= NFS_DEF_ACREGMIN;
1554 		ctx->acregmax		= NFS_DEF_ACREGMAX;
1555 		ctx->acdirmin		= NFS_DEF_ACDIRMIN;
1556 		ctx->acdirmax		= NFS_DEF_ACDIRMAX;
1557 		ctx->nfs_server.port	= NFS_UNSPEC_PORT;
1558 		ctx->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1559 		ctx->selected_flavor	= RPC_AUTH_MAXFLAVOR;
1560 		ctx->minorversion	= 0;
1561 		ctx->need_mount		= true;
1562 
1563 		fc->s_iflags		|= SB_I_STABLE_WRITES;
1564 	}
1565 	fc->fs_private = ctx;
1566 	fc->ops = &nfs_fs_context_ops;
1567 	return 0;
1568 }
1569 
1570 struct file_system_type nfs_fs_type = {
1571 	.owner			= THIS_MODULE,
1572 	.name			= "nfs",
1573 	.init_fs_context	= nfs_init_fs_context,
1574 	.parameters		= nfs_fs_parameters,
1575 	.kill_sb		= nfs_kill_super,
1576 	.fs_flags		= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
1577 };
1578 MODULE_ALIAS_FS("nfs");
1579 EXPORT_SYMBOL_GPL(nfs_fs_type);
1580 
1581 #if IS_ENABLED(CONFIG_NFS_V4)
1582 struct file_system_type nfs4_fs_type = {
1583 	.owner			= THIS_MODULE,
1584 	.name			= "nfs4",
1585 	.init_fs_context	= nfs_init_fs_context,
1586 	.parameters		= nfs_fs_parameters,
1587 	.kill_sb		= nfs_kill_super,
1588 	.fs_flags		= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
1589 };
1590 MODULE_ALIAS_FS("nfs4");
1591 MODULE_ALIAS("nfs4");
1592 EXPORT_SYMBOL_GPL(nfs4_fs_type);
1593 #endif /* CONFIG_NFS_V4 */
1594