fs/nfs/fs_context.c

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