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