xref: /linux/fs/nfs/fs_context.c (revision 43b46e6bc69c2aa4331cfd7fa4e2943a894339e5)
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 		trace_nfs_mount_assign(param->key, param->string);
688 		ret = nfs_parse_version_string(fc, param->string);
689 		if (ret < 0)
690 			return ret;
691 		break;
692 	case Opt_sec:
693 		ret = nfs_parse_security_flavors(fc, param);
694 		if (ret < 0)
695 			return ret;
696 		break;
697 
698 	case Opt_proto:
699 		trace_nfs_mount_assign(param->key, param->string);
700 		protofamily = AF_INET;
701 		switch (lookup_constant(nfs_xprt_protocol_tokens, param->string, -1)) {
702 		case Opt_xprt_udp6:
703 			protofamily = AF_INET6;
704 			fallthrough;
705 		case Opt_xprt_udp:
706 			ctx->flags &= ~NFS_MOUNT_TCP;
707 			ctx->nfs_server.protocol = XPRT_TRANSPORT_UDP;
708 			break;
709 		case Opt_xprt_tcp6:
710 			protofamily = AF_INET6;
711 			fallthrough;
712 		case Opt_xprt_tcp:
713 			ctx->flags |= NFS_MOUNT_TCP;
714 			ctx->nfs_server.protocol = XPRT_TRANSPORT_TCP;
715 			break;
716 		case Opt_xprt_rdma6:
717 			protofamily = AF_INET6;
718 			fallthrough;
719 		case Opt_xprt_rdma:
720 			/* vector side protocols to TCP */
721 			ctx->flags |= NFS_MOUNT_TCP;
722 			ret = xprt_find_transport_ident(param->string);
723 			if (ret < 0)
724 				goto out_bad_transport;
725 			ctx->nfs_server.protocol = ret;
726 			break;
727 		default:
728 			goto out_bad_transport;
729 		}
730 
731 		ctx->protofamily = protofamily;
732 		break;
733 
734 	case Opt_mountproto:
735 		trace_nfs_mount_assign(param->key, param->string);
736 		mountfamily = AF_INET;
737 		switch (lookup_constant(nfs_xprt_protocol_tokens, param->string, -1)) {
738 		case Opt_xprt_udp6:
739 			mountfamily = AF_INET6;
740 			fallthrough;
741 		case Opt_xprt_udp:
742 			ctx->mount_server.protocol = XPRT_TRANSPORT_UDP;
743 			break;
744 		case Opt_xprt_tcp6:
745 			mountfamily = AF_INET6;
746 			fallthrough;
747 		case Opt_xprt_tcp:
748 			ctx->mount_server.protocol = XPRT_TRANSPORT_TCP;
749 			break;
750 		case Opt_xprt_rdma: /* not used for side protocols */
751 		default:
752 			goto out_bad_transport;
753 		}
754 		ctx->mountfamily = mountfamily;
755 		break;
756 
757 	case Opt_addr:
758 		trace_nfs_mount_assign(param->key, param->string);
759 		len = rpc_pton(fc->net_ns, param->string, param->size,
760 			       &ctx->nfs_server.address,
761 			       sizeof(ctx->nfs_server._address));
762 		if (len == 0)
763 			goto out_invalid_address;
764 		ctx->nfs_server.addrlen = len;
765 		break;
766 	case Opt_clientaddr:
767 		trace_nfs_mount_assign(param->key, param->string);
768 		kfree(ctx->client_address);
769 		ctx->client_address = param->string;
770 		param->string = NULL;
771 		break;
772 	case Opt_mounthost:
773 		trace_nfs_mount_assign(param->key, param->string);
774 		kfree(ctx->mount_server.hostname);
775 		ctx->mount_server.hostname = param->string;
776 		param->string = NULL;
777 		break;
778 	case Opt_mountaddr:
779 		trace_nfs_mount_assign(param->key, param->string);
780 		len = rpc_pton(fc->net_ns, param->string, param->size,
781 			       &ctx->mount_server.address,
782 			       sizeof(ctx->mount_server._address));
783 		if (len == 0)
784 			goto out_invalid_address;
785 		ctx->mount_server.addrlen = len;
786 		break;
787 	case Opt_nconnect:
788 		if (result.uint_32 < 1 || result.uint_32 > NFS_MAX_CONNECTIONS)
789 			goto out_of_bounds;
790 		ctx->nfs_server.nconnect = result.uint_32;
791 		break;
792 	case Opt_max_connect:
793 		if (result.uint_32 < 1 || result.uint_32 > NFS_MAX_TRANSPORTS)
794 			goto out_of_bounds;
795 		ctx->nfs_server.max_connect = result.uint_32;
796 		break;
797 	case Opt_lookupcache:
798 		switch (result.uint_32) {
799 		case Opt_lookupcache_all:
800 			ctx->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
801 			break;
802 		case Opt_lookupcache_positive:
803 			ctx->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
804 			ctx->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
805 			break;
806 		case Opt_lookupcache_none:
807 			ctx->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
808 			break;
809 		default:
810 			goto out_invalid_value;
811 		}
812 		break;
813 	case Opt_local_lock:
814 		switch (result.uint_32) {
815 		case Opt_local_lock_all:
816 			ctx->flags |= (NFS_MOUNT_LOCAL_FLOCK |
817 				       NFS_MOUNT_LOCAL_FCNTL);
818 			break;
819 		case Opt_local_lock_flock:
820 			ctx->flags |= NFS_MOUNT_LOCAL_FLOCK;
821 			break;
822 		case Opt_local_lock_posix:
823 			ctx->flags |= NFS_MOUNT_LOCAL_FCNTL;
824 			break;
825 		case Opt_local_lock_none:
826 			ctx->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
827 					NFS_MOUNT_LOCAL_FCNTL);
828 			break;
829 		default:
830 			goto out_invalid_value;
831 		}
832 		break;
833 	case Opt_write:
834 		switch (result.uint_32) {
835 		case Opt_write_lazy:
836 			ctx->flags &=
837 				~(NFS_MOUNT_WRITE_EAGER | NFS_MOUNT_WRITE_WAIT);
838 			break;
839 		case Opt_write_eager:
840 			ctx->flags |= NFS_MOUNT_WRITE_EAGER;
841 			ctx->flags &= ~NFS_MOUNT_WRITE_WAIT;
842 			break;
843 		case Opt_write_wait:
844 			ctx->flags |=
845 				NFS_MOUNT_WRITE_EAGER | NFS_MOUNT_WRITE_WAIT;
846 			break;
847 		default:
848 			goto out_invalid_value;
849 		}
850 		break;
851 
852 		/*
853 		 * Special options
854 		 */
855 	case Opt_sloppy:
856 		ctx->sloppy = true;
857 		break;
858 	}
859 
860 	return 0;
861 
862 out_invalid_value:
863 	return nfs_invalf(fc, "NFS: Bad mount option value specified");
864 out_invalid_address:
865 	return nfs_invalf(fc, "NFS: Bad IP address specified");
866 out_of_bounds:
867 	return nfs_invalf(fc, "NFS: Value for '%s' out of range", param->key);
868 out_bad_transport:
869 	return nfs_invalf(fc, "NFS: Unrecognized transport protocol");
870 }
871 
872 /*
873  * Split fc->source into "hostname:export_path".
874  *
875  * The leftmost colon demarks the split between the server's hostname
876  * and the export path.  If the hostname starts with a left square
877  * bracket, then it may contain colons.
878  *
879  * Note: caller frees hostname and export path, even on error.
880  */
881 static int nfs_parse_source(struct fs_context *fc,
882 			    size_t maxnamlen, size_t maxpathlen)
883 {
884 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
885 	const char *dev_name = fc->source;
886 	size_t len;
887 	const char *end;
888 
889 	if (unlikely(!dev_name || !*dev_name))
890 		return -EINVAL;
891 
892 	/* Is the host name protected with square brakcets? */
893 	if (*dev_name == '[') {
894 		end = strchr(++dev_name, ']');
895 		if (end == NULL || end[1] != ':')
896 			goto out_bad_devname;
897 
898 		len = end - dev_name;
899 		end++;
900 	} else {
901 		const char *comma;
902 
903 		end = strchr(dev_name, ':');
904 		if (end == NULL)
905 			goto out_bad_devname;
906 		len = end - dev_name;
907 
908 		/* kill possible hostname list: not supported */
909 		comma = memchr(dev_name, ',', len);
910 		if (comma)
911 			len = comma - dev_name;
912 	}
913 
914 	if (len > maxnamlen)
915 		goto out_hostname;
916 
917 	kfree(ctx->nfs_server.hostname);
918 
919 	/* N.B. caller will free nfs_server.hostname in all cases */
920 	ctx->nfs_server.hostname = kmemdup_nul(dev_name, len, GFP_KERNEL);
921 	if (!ctx->nfs_server.hostname)
922 		goto out_nomem;
923 	len = strlen(++end);
924 	if (len > maxpathlen)
925 		goto out_path;
926 	ctx->nfs_server.export_path = kmemdup_nul(end, len, GFP_KERNEL);
927 	if (!ctx->nfs_server.export_path)
928 		goto out_nomem;
929 
930 	trace_nfs_mount_path(ctx->nfs_server.export_path);
931 	return 0;
932 
933 out_bad_devname:
934 	return nfs_invalf(fc, "NFS: device name not in host:path format");
935 out_nomem:
936 	nfs_errorf(fc, "NFS: not enough memory to parse device name");
937 	return -ENOMEM;
938 out_hostname:
939 	nfs_errorf(fc, "NFS: server hostname too long");
940 	return -ENAMETOOLONG;
941 out_path:
942 	nfs_errorf(fc, "NFS: export pathname too long");
943 	return -ENAMETOOLONG;
944 }
945 
946 static inline bool is_remount_fc(struct fs_context *fc)
947 {
948 	return fc->root != NULL;
949 }
950 
951 /*
952  * Parse monolithic NFS2/NFS3 mount data
953  * - fills in the mount root filehandle
954  *
955  * For option strings, user space handles the following behaviors:
956  *
957  * + DNS: mapping server host name to IP address ("addr=" option)
958  *
959  * + failure mode: how to behave if a mount request can't be handled
960  *   immediately ("fg/bg" option)
961  *
962  * + retry: how often to retry a mount request ("retry=" option)
963  *
964  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
965  *   mountproto=tcp after mountproto=udp, and so on
966  */
967 static int nfs23_parse_monolithic(struct fs_context *fc,
968 				  struct nfs_mount_data *data)
969 {
970 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
971 	struct nfs_fh *mntfh = ctx->mntfh;
972 	struct sockaddr_storage *sap = &ctx->nfs_server._address;
973 	int extra_flags = NFS_MOUNT_LEGACY_INTERFACE;
974 	int ret;
975 
976 	if (data == NULL)
977 		goto out_no_data;
978 
979 	ctx->version = NFS_DEFAULT_VERSION;
980 	switch (data->version) {
981 	case 1:
982 		data->namlen = 0;
983 		fallthrough;
984 	case 2:
985 		data->bsize = 0;
986 		fallthrough;
987 	case 3:
988 		if (data->flags & NFS_MOUNT_VER3)
989 			goto out_no_v3;
990 		data->root.size = NFS2_FHSIZE;
991 		memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
992 		/* Turn off security negotiation */
993 		extra_flags |= NFS_MOUNT_SECFLAVOUR;
994 		fallthrough;
995 	case 4:
996 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
997 			goto out_no_sec;
998 		fallthrough;
999 	case 5:
1000 		memset(data->context, 0, sizeof(data->context));
1001 		fallthrough;
1002 	case 6:
1003 		if (data->flags & NFS_MOUNT_VER3) {
1004 			if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1005 				goto out_invalid_fh;
1006 			mntfh->size = data->root.size;
1007 			ctx->version = 3;
1008 		} else {
1009 			mntfh->size = NFS2_FHSIZE;
1010 			ctx->version = 2;
1011 		}
1012 
1013 
1014 		memcpy(mntfh->data, data->root.data, mntfh->size);
1015 		if (mntfh->size < sizeof(mntfh->data))
1016 			memset(mntfh->data + mntfh->size, 0,
1017 			       sizeof(mntfh->data) - mntfh->size);
1018 
1019 		/*
1020 		 * for proto == XPRT_TRANSPORT_UDP, which is what uses
1021 		 * to_exponential, implying shift: limit the shift value
1022 		 * to BITS_PER_LONG (majortimeo is unsigned long)
1023 		 */
1024 		if (!(data->flags & NFS_MOUNT_TCP)) /* this will be UDP */
1025 			if (data->retrans >= 64) /* shift value is too large */
1026 				goto out_invalid_data;
1027 
1028 		/*
1029 		 * Translate to nfs_fs_context, which nfs_fill_super
1030 		 * can deal with.
1031 		 */
1032 		ctx->flags	= data->flags & NFS_MOUNT_FLAGMASK;
1033 		ctx->flags	|= extra_flags;
1034 		ctx->rsize	= data->rsize;
1035 		ctx->wsize	= data->wsize;
1036 		ctx->timeo	= data->timeo;
1037 		ctx->retrans	= data->retrans;
1038 		ctx->acregmin	= data->acregmin;
1039 		ctx->acregmax	= data->acregmax;
1040 		ctx->acdirmin	= data->acdirmin;
1041 		ctx->acdirmax	= data->acdirmax;
1042 		ctx->need_mount	= false;
1043 
1044 		memcpy(sap, &data->addr, sizeof(data->addr));
1045 		ctx->nfs_server.addrlen = sizeof(data->addr);
1046 		ctx->nfs_server.port = ntohs(data->addr.sin_port);
1047 		if (sap->ss_family != AF_INET ||
1048 		    !nfs_verify_server_address(sap))
1049 			goto out_no_address;
1050 
1051 		if (!(data->flags & NFS_MOUNT_TCP))
1052 			ctx->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1053 		/* N.B. caller will free nfs_server.hostname in all cases */
1054 		ctx->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1055 		if (!ctx->nfs_server.hostname)
1056 			goto out_nomem;
1057 
1058 		ctx->namlen		= data->namlen;
1059 		ctx->bsize		= data->bsize;
1060 
1061 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
1062 			ctx->selected_flavor = data->pseudoflavor;
1063 		else
1064 			ctx->selected_flavor = RPC_AUTH_UNIX;
1065 
1066 		if (!(data->flags & NFS_MOUNT_NONLM))
1067 			ctx->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
1068 					 NFS_MOUNT_LOCAL_FCNTL);
1069 		else
1070 			ctx->flags |= (NFS_MOUNT_LOCAL_FLOCK|
1071 					NFS_MOUNT_LOCAL_FCNTL);
1072 
1073 		/*
1074 		 * The legacy version 6 binary mount data from userspace has a
1075 		 * field used only to transport selinux information into the
1076 		 * kernel.  To continue to support that functionality we
1077 		 * have a touch of selinux knowledge here in the NFS code. The
1078 		 * userspace code converted context=blah to just blah so we are
1079 		 * converting back to the full string selinux understands.
1080 		 */
1081 		if (data->context[0]){
1082 #ifdef CONFIG_SECURITY_SELINUX
1083 			int ret;
1084 
1085 			data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1086 			ret = vfs_parse_fs_string(fc, "context",
1087 						  data->context, strlen(data->context));
1088 			if (ret < 0)
1089 				return ret;
1090 #else
1091 			return -EINVAL;
1092 #endif
1093 		}
1094 
1095 		break;
1096 	default:
1097 		goto generic;
1098 	}
1099 
1100 	ret = nfs_validate_transport_protocol(fc, ctx);
1101 	if (ret)
1102 		return ret;
1103 
1104 	ctx->skip_reconfig_option_check = true;
1105 	return 0;
1106 
1107 generic:
1108 	return generic_parse_monolithic(fc, data);
1109 
1110 out_no_data:
1111 	if (is_remount_fc(fc)) {
1112 		ctx->skip_reconfig_option_check = true;
1113 		return 0;
1114 	}
1115 	return nfs_invalf(fc, "NFS: mount program didn't pass any mount data");
1116 
1117 out_no_v3:
1118 	return nfs_invalf(fc, "NFS: nfs_mount_data version does not support v3");
1119 
1120 out_no_sec:
1121 	return nfs_invalf(fc, "NFS: nfs_mount_data version supports only AUTH_SYS");
1122 
1123 out_nomem:
1124 	return -ENOMEM;
1125 
1126 out_no_address:
1127 	return nfs_invalf(fc, "NFS: mount program didn't pass remote address");
1128 
1129 out_invalid_fh:
1130 	return nfs_invalf(fc, "NFS: invalid root filehandle");
1131 
1132 out_invalid_data:
1133 	return nfs_invalf(fc, "NFS: invalid binary mount data");
1134 }
1135 
1136 #if IS_ENABLED(CONFIG_NFS_V4)
1137 struct compat_nfs_string {
1138 	compat_uint_t len;
1139 	compat_uptr_t data;
1140 };
1141 
1142 static inline void compat_nfs_string(struct nfs_string *dst,
1143 				     struct compat_nfs_string *src)
1144 {
1145 	dst->data = compat_ptr(src->data);
1146 	dst->len = src->len;
1147 }
1148 
1149 struct compat_nfs4_mount_data_v1 {
1150 	compat_int_t version;
1151 	compat_int_t flags;
1152 	compat_int_t rsize;
1153 	compat_int_t wsize;
1154 	compat_int_t timeo;
1155 	compat_int_t retrans;
1156 	compat_int_t acregmin;
1157 	compat_int_t acregmax;
1158 	compat_int_t acdirmin;
1159 	compat_int_t acdirmax;
1160 	struct compat_nfs_string client_addr;
1161 	struct compat_nfs_string mnt_path;
1162 	struct compat_nfs_string hostname;
1163 	compat_uint_t host_addrlen;
1164 	compat_uptr_t host_addr;
1165 	compat_int_t proto;
1166 	compat_int_t auth_flavourlen;
1167 	compat_uptr_t auth_flavours;
1168 };
1169 
1170 static void nfs4_compat_mount_data_conv(struct nfs4_mount_data *data)
1171 {
1172 	struct compat_nfs4_mount_data_v1 *compat =
1173 			(struct compat_nfs4_mount_data_v1 *)data;
1174 
1175 	/* copy the fields backwards */
1176 	data->auth_flavours = compat_ptr(compat->auth_flavours);
1177 	data->auth_flavourlen = compat->auth_flavourlen;
1178 	data->proto = compat->proto;
1179 	data->host_addr = compat_ptr(compat->host_addr);
1180 	data->host_addrlen = compat->host_addrlen;
1181 	compat_nfs_string(&data->hostname, &compat->hostname);
1182 	compat_nfs_string(&data->mnt_path, &compat->mnt_path);
1183 	compat_nfs_string(&data->client_addr, &compat->client_addr);
1184 	data->acdirmax = compat->acdirmax;
1185 	data->acdirmin = compat->acdirmin;
1186 	data->acregmax = compat->acregmax;
1187 	data->acregmin = compat->acregmin;
1188 	data->retrans = compat->retrans;
1189 	data->timeo = compat->timeo;
1190 	data->wsize = compat->wsize;
1191 	data->rsize = compat->rsize;
1192 	data->flags = compat->flags;
1193 	data->version = compat->version;
1194 }
1195 
1196 /*
1197  * Validate NFSv4 mount options
1198  */
1199 static int nfs4_parse_monolithic(struct fs_context *fc,
1200 				 struct nfs4_mount_data *data)
1201 {
1202 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
1203 	struct sockaddr_storage *sap = &ctx->nfs_server._address;
1204 	int ret;
1205 	char *c;
1206 
1207 	if (!data) {
1208 		if (is_remount_fc(fc))
1209 			goto done;
1210 		return nfs_invalf(fc,
1211 			"NFS4: mount program didn't pass any mount data");
1212 	}
1213 
1214 	ctx->version = 4;
1215 
1216 	if (data->version != 1)
1217 		return generic_parse_monolithic(fc, data);
1218 
1219 	if (in_compat_syscall())
1220 		nfs4_compat_mount_data_conv(data);
1221 
1222 	if (data->host_addrlen > sizeof(ctx->nfs_server.address))
1223 		goto out_no_address;
1224 	if (data->host_addrlen == 0)
1225 		goto out_no_address;
1226 	ctx->nfs_server.addrlen = data->host_addrlen;
1227 	if (copy_from_user(sap, data->host_addr, data->host_addrlen))
1228 		return -EFAULT;
1229 	if (!nfs_verify_server_address(sap))
1230 		goto out_no_address;
1231 	ctx->nfs_server.port = ntohs(((struct sockaddr_in *)sap)->sin_port);
1232 
1233 	if (data->auth_flavourlen) {
1234 		rpc_authflavor_t pseudoflavor;
1235 
1236 		if (data->auth_flavourlen > 1)
1237 			goto out_inval_auth;
1238 		if (copy_from_user(&pseudoflavor, data->auth_flavours,
1239 				   sizeof(pseudoflavor)))
1240 			return -EFAULT;
1241 		ctx->selected_flavor = pseudoflavor;
1242 	} else {
1243 		ctx->selected_flavor = RPC_AUTH_UNIX;
1244 	}
1245 
1246 	c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
1247 	if (IS_ERR(c))
1248 		return PTR_ERR(c);
1249 	ctx->nfs_server.hostname = c;
1250 
1251 	c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
1252 	if (IS_ERR(c))
1253 		return PTR_ERR(c);
1254 	ctx->nfs_server.export_path = c;
1255 	trace_nfs_mount_path(c);
1256 
1257 	c = strndup_user(data->client_addr.data, 16);
1258 	if (IS_ERR(c))
1259 		return PTR_ERR(c);
1260 	ctx->client_address = c;
1261 
1262 	/*
1263 	 * Translate to nfs_fs_context, which nfs_fill_super
1264 	 * can deal with.
1265 	 */
1266 
1267 	ctx->flags	= data->flags & NFS4_MOUNT_FLAGMASK;
1268 	ctx->rsize	= data->rsize;
1269 	ctx->wsize	= data->wsize;
1270 	ctx->timeo	= data->timeo;
1271 	ctx->retrans	= data->retrans;
1272 	ctx->acregmin	= data->acregmin;
1273 	ctx->acregmax	= data->acregmax;
1274 	ctx->acdirmin	= data->acdirmin;
1275 	ctx->acdirmax	= data->acdirmax;
1276 	ctx->nfs_server.protocol = data->proto;
1277 	ret = nfs_validate_transport_protocol(fc, ctx);
1278 	if (ret)
1279 		return ret;
1280 done:
1281 	ctx->skip_reconfig_option_check = true;
1282 	return 0;
1283 
1284 out_inval_auth:
1285 	return nfs_invalf(fc, "NFS4: Invalid number of RPC auth flavours %d",
1286 		      data->auth_flavourlen);
1287 
1288 out_no_address:
1289 	return nfs_invalf(fc, "NFS4: mount program didn't pass remote address");
1290 }
1291 #endif
1292 
1293 /*
1294  * Parse a monolithic block of data from sys_mount().
1295  */
1296 static int nfs_fs_context_parse_monolithic(struct fs_context *fc,
1297 					   void *data)
1298 {
1299 	if (fc->fs_type == &nfs_fs_type)
1300 		return nfs23_parse_monolithic(fc, data);
1301 
1302 #if IS_ENABLED(CONFIG_NFS_V4)
1303 	if (fc->fs_type == &nfs4_fs_type)
1304 		return nfs4_parse_monolithic(fc, data);
1305 #endif
1306 
1307 	return nfs_invalf(fc, "NFS: Unsupported monolithic data version");
1308 }
1309 
1310 /*
1311  * Validate the preparsed information in the config.
1312  */
1313 static int nfs_fs_context_validate(struct fs_context *fc)
1314 {
1315 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
1316 	struct nfs_subversion *nfs_mod;
1317 	struct sockaddr_storage *sap = &ctx->nfs_server._address;
1318 	int max_namelen = PAGE_SIZE;
1319 	int max_pathlen = NFS_MAXPATHLEN;
1320 	int port = 0;
1321 	int ret;
1322 
1323 	if (!fc->source)
1324 		goto out_no_device_name;
1325 
1326 	/* Check for sanity first. */
1327 	if (ctx->minorversion && ctx->version != 4)
1328 		goto out_minorversion_mismatch;
1329 
1330 	if (ctx->options & NFS_OPTION_MIGRATION &&
1331 	    (ctx->version != 4 || ctx->minorversion != 0))
1332 		goto out_migration_misuse;
1333 
1334 	/* Verify that any proto=/mountproto= options match the address
1335 	 * families in the addr=/mountaddr= options.
1336 	 */
1337 	if (ctx->protofamily != AF_UNSPEC &&
1338 	    ctx->protofamily != ctx->nfs_server.address.sa_family)
1339 		goto out_proto_mismatch;
1340 
1341 	if (ctx->mountfamily != AF_UNSPEC) {
1342 		if (ctx->mount_server.addrlen) {
1343 			if (ctx->mountfamily != ctx->mount_server.address.sa_family)
1344 				goto out_mountproto_mismatch;
1345 		} else {
1346 			if (ctx->mountfamily != ctx->nfs_server.address.sa_family)
1347 				goto out_mountproto_mismatch;
1348 		}
1349 	}
1350 
1351 	if (!nfs_verify_server_address(sap))
1352 		goto out_no_address;
1353 
1354 	ret = nfs_validate_transport_protocol(fc, ctx);
1355 	if (ret)
1356 		return ret;
1357 
1358 	if (ctx->version == 4) {
1359 		if (IS_ENABLED(CONFIG_NFS_V4)) {
1360 			if (ctx->nfs_server.protocol == XPRT_TRANSPORT_RDMA)
1361 				port = NFS_RDMA_PORT;
1362 			else
1363 				port = NFS_PORT;
1364 			max_namelen = NFS4_MAXNAMLEN;
1365 			max_pathlen = NFS4_MAXPATHLEN;
1366 			ctx->flags &= ~(NFS_MOUNT_NONLM | NFS_MOUNT_NOACL |
1367 					NFS_MOUNT_VER3 | NFS_MOUNT_LOCAL_FLOCK |
1368 					NFS_MOUNT_LOCAL_FCNTL);
1369 		} else {
1370 			goto out_v4_not_compiled;
1371 		}
1372 	} else {
1373 		nfs_set_mount_transport_protocol(ctx);
1374 		if (ctx->nfs_server.protocol == XPRT_TRANSPORT_RDMA)
1375 			port = NFS_RDMA_PORT;
1376 	}
1377 
1378 	nfs_set_port(sap, &ctx->nfs_server.port, port);
1379 
1380 	ret = nfs_parse_source(fc, max_namelen, max_pathlen);
1381 	if (ret < 0)
1382 		return ret;
1383 
1384 	/* Load the NFS protocol module if we haven't done so yet */
1385 	if (!ctx->nfs_mod) {
1386 		nfs_mod = get_nfs_version(ctx->version);
1387 		if (IS_ERR(nfs_mod)) {
1388 			ret = PTR_ERR(nfs_mod);
1389 			goto out_version_unavailable;
1390 		}
1391 		ctx->nfs_mod = nfs_mod;
1392 	}
1393 
1394 	/* Ensure the filesystem context has the correct fs_type */
1395 	if (fc->fs_type != ctx->nfs_mod->nfs_fs) {
1396 		module_put(fc->fs_type->owner);
1397 		__module_get(ctx->nfs_mod->nfs_fs->owner);
1398 		fc->fs_type = ctx->nfs_mod->nfs_fs;
1399 	}
1400 	return 0;
1401 
1402 out_no_device_name:
1403 	return nfs_invalf(fc, "NFS: Device name not specified");
1404 out_v4_not_compiled:
1405 	nfs_errorf(fc, "NFS: NFSv4 is not compiled into kernel");
1406 	return -EPROTONOSUPPORT;
1407 out_no_address:
1408 	return nfs_invalf(fc, "NFS: mount program didn't pass remote address");
1409 out_mountproto_mismatch:
1410 	return nfs_invalf(fc, "NFS: Mount server address does not match mountproto= option");
1411 out_proto_mismatch:
1412 	return nfs_invalf(fc, "NFS: Server address does not match proto= option");
1413 out_minorversion_mismatch:
1414 	return nfs_invalf(fc, "NFS: Mount option vers=%u does not support minorversion=%u",
1415 			  ctx->version, ctx->minorversion);
1416 out_migration_misuse:
1417 	return nfs_invalf(fc, "NFS: 'Migration' not supported for this NFS version");
1418 out_version_unavailable:
1419 	nfs_errorf(fc, "NFS: Version unavailable");
1420 	return ret;
1421 }
1422 
1423 /*
1424  * Create an NFS superblock by the appropriate method.
1425  */
1426 static int nfs_get_tree(struct fs_context *fc)
1427 {
1428 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
1429 	int err = nfs_fs_context_validate(fc);
1430 
1431 	if (err)
1432 		return err;
1433 	if (!ctx->internal)
1434 		return ctx->nfs_mod->rpc_ops->try_get_tree(fc);
1435 	else
1436 		return nfs_get_tree_common(fc);
1437 }
1438 
1439 /*
1440  * Handle duplication of a configuration.  The caller copied *src into *sc, but
1441  * it can't deal with resource pointers in the filesystem context, so we have
1442  * to do that.  We need to clear pointers, copy data or get extra refs as
1443  * appropriate.
1444  */
1445 static int nfs_fs_context_dup(struct fs_context *fc, struct fs_context *src_fc)
1446 {
1447 	struct nfs_fs_context *src = nfs_fc2context(src_fc), *ctx;
1448 
1449 	ctx = kmemdup(src, sizeof(struct nfs_fs_context), GFP_KERNEL);
1450 	if (!ctx)
1451 		return -ENOMEM;
1452 
1453 	ctx->mntfh = nfs_alloc_fhandle();
1454 	if (!ctx->mntfh) {
1455 		kfree(ctx);
1456 		return -ENOMEM;
1457 	}
1458 	nfs_copy_fh(ctx->mntfh, src->mntfh);
1459 
1460 	__module_get(ctx->nfs_mod->owner);
1461 	ctx->client_address		= NULL;
1462 	ctx->mount_server.hostname	= NULL;
1463 	ctx->nfs_server.export_path	= NULL;
1464 	ctx->nfs_server.hostname	= NULL;
1465 	ctx->fscache_uniq		= NULL;
1466 	ctx->clone_data.fattr		= NULL;
1467 	fc->fs_private = ctx;
1468 	return 0;
1469 }
1470 
1471 static void nfs_fs_context_free(struct fs_context *fc)
1472 {
1473 	struct nfs_fs_context *ctx = nfs_fc2context(fc);
1474 
1475 	if (ctx) {
1476 		if (ctx->server)
1477 			nfs_free_server(ctx->server);
1478 		if (ctx->nfs_mod)
1479 			put_nfs_version(ctx->nfs_mod);
1480 		kfree(ctx->client_address);
1481 		kfree(ctx->mount_server.hostname);
1482 		kfree(ctx->nfs_server.export_path);
1483 		kfree(ctx->nfs_server.hostname);
1484 		kfree(ctx->fscache_uniq);
1485 		nfs_free_fhandle(ctx->mntfh);
1486 		nfs_free_fattr(ctx->clone_data.fattr);
1487 		kfree(ctx);
1488 	}
1489 }
1490 
1491 static const struct fs_context_operations nfs_fs_context_ops = {
1492 	.free			= nfs_fs_context_free,
1493 	.dup			= nfs_fs_context_dup,
1494 	.parse_param		= nfs_fs_context_parse_param,
1495 	.parse_monolithic	= nfs_fs_context_parse_monolithic,
1496 	.get_tree		= nfs_get_tree,
1497 	.reconfigure		= nfs_reconfigure,
1498 };
1499 
1500 /*
1501  * Prepare superblock configuration.  We use the namespaces attached to the
1502  * context.  This may be the current process's namespaces, or it may be a
1503  * container's namespaces.
1504  */
1505 static int nfs_init_fs_context(struct fs_context *fc)
1506 {
1507 	struct nfs_fs_context *ctx;
1508 
1509 	ctx = kzalloc(sizeof(struct nfs_fs_context), GFP_KERNEL);
1510 	if (unlikely(!ctx))
1511 		return -ENOMEM;
1512 
1513 	ctx->mntfh = nfs_alloc_fhandle();
1514 	if (unlikely(!ctx->mntfh)) {
1515 		kfree(ctx);
1516 		return -ENOMEM;
1517 	}
1518 
1519 	ctx->protofamily	= AF_UNSPEC;
1520 	ctx->mountfamily	= AF_UNSPEC;
1521 	ctx->mount_server.port	= NFS_UNSPEC_PORT;
1522 
1523 	if (fc->root) {
1524 		/* reconfigure, start with the current config */
1525 		struct nfs_server *nfss = fc->root->d_sb->s_fs_info;
1526 		struct net *net = nfss->nfs_client->cl_net;
1527 
1528 		ctx->flags		= nfss->flags;
1529 		ctx->rsize		= nfss->rsize;
1530 		ctx->wsize		= nfss->wsize;
1531 		ctx->retrans		= nfss->client->cl_timeout->to_retries;
1532 		ctx->selected_flavor	= nfss->client->cl_auth->au_flavor;
1533 		ctx->acregmin		= nfss->acregmin / HZ;
1534 		ctx->acregmax		= nfss->acregmax / HZ;
1535 		ctx->acdirmin		= nfss->acdirmin / HZ;
1536 		ctx->acdirmax		= nfss->acdirmax / HZ;
1537 		ctx->timeo		= 10U * nfss->client->cl_timeout->to_initval / HZ;
1538 		ctx->nfs_server.port	= nfss->port;
1539 		ctx->nfs_server.addrlen	= nfss->nfs_client->cl_addrlen;
1540 		ctx->version		= nfss->nfs_client->rpc_ops->version;
1541 		ctx->minorversion	= nfss->nfs_client->cl_minorversion;
1542 
1543 		memcpy(&ctx->nfs_server._address, &nfss->nfs_client->cl_addr,
1544 			ctx->nfs_server.addrlen);
1545 
1546 		if (fc->net_ns != net) {
1547 			put_net(fc->net_ns);
1548 			fc->net_ns = get_net(net);
1549 		}
1550 
1551 		ctx->nfs_mod = nfss->nfs_client->cl_nfs_mod;
1552 		__module_get(ctx->nfs_mod->owner);
1553 	} else {
1554 		/* defaults */
1555 		ctx->timeo		= NFS_UNSPEC_TIMEO;
1556 		ctx->retrans		= NFS_UNSPEC_RETRANS;
1557 		ctx->acregmin		= NFS_DEF_ACREGMIN;
1558 		ctx->acregmax		= NFS_DEF_ACREGMAX;
1559 		ctx->acdirmin		= NFS_DEF_ACDIRMIN;
1560 		ctx->acdirmax		= NFS_DEF_ACDIRMAX;
1561 		ctx->nfs_server.port	= NFS_UNSPEC_PORT;
1562 		ctx->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1563 		ctx->selected_flavor	= RPC_AUTH_MAXFLAVOR;
1564 		ctx->minorversion	= 0;
1565 		ctx->need_mount		= true;
1566 
1567 		fc->s_iflags		|= SB_I_STABLE_WRITES;
1568 	}
1569 	fc->fs_private = ctx;
1570 	fc->ops = &nfs_fs_context_ops;
1571 	return 0;
1572 }
1573 
1574 struct file_system_type nfs_fs_type = {
1575 	.owner			= THIS_MODULE,
1576 	.name			= "nfs",
1577 	.init_fs_context	= nfs_init_fs_context,
1578 	.parameters		= nfs_fs_parameters,
1579 	.kill_sb		= nfs_kill_super,
1580 	.fs_flags		= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
1581 };
1582 MODULE_ALIAS_FS("nfs");
1583 EXPORT_SYMBOL_GPL(nfs_fs_type);
1584 
1585 #if IS_ENABLED(CONFIG_NFS_V4)
1586 struct file_system_type nfs4_fs_type = {
1587 	.owner			= THIS_MODULE,
1588 	.name			= "nfs4",
1589 	.init_fs_context	= nfs_init_fs_context,
1590 	.parameters		= nfs_fs_parameters,
1591 	.kill_sb		= nfs_kill_super,
1592 	.fs_flags		= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
1593 };
1594 MODULE_ALIAS_FS("nfs4");
1595 MODULE_ALIAS("nfs4");
1596 EXPORT_SYMBOL_GPL(nfs4_fs_type);
1597 #endif /* CONFIG_NFS_V4 */
1598