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                 ctx->flags |= NFS_MOUNT_TCP;
 514                 ctx->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 515                 break;
 516         case Opt_rdma:
 517                 ctx->flags |= NFS_MOUNT_TCP; /* for side protocols */
 518                 ctx->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
 519                 xprt_load_transport(param->key);
 520                 break;
 521         case Opt_acl:
 522                 if (result.negated)
 523                         ctx->flags |= NFS_MOUNT_NOACL;
 524                 else
 525                         ctx->flags &= ~NFS_MOUNT_NOACL;
 526                 break;
 527         case Opt_rdirplus:
 528                 if (result.negated)
 529                         ctx->flags |= NFS_MOUNT_NORDIRPLUS;
 530                 else
 531                         ctx->flags &= ~NFS_MOUNT_NORDIRPLUS;
 532                 break;
 533         case Opt_sharecache:
 534                 if (result.negated)
 535                         ctx->flags |= NFS_MOUNT_UNSHARED;
 536                 else
 537                         ctx->flags &= ~NFS_MOUNT_UNSHARED;
 538                 break;
 539         case Opt_resvport:
 540                 if (result.negated)
 541                         ctx->flags |= NFS_MOUNT_NORESVPORT;
 542                 else
 543                         ctx->flags &= ~NFS_MOUNT_NORESVPORT;
 544                 break;
 545         case Opt_fscache_flag:
 546                 if (result.negated)
 547                         ctx->options &= ~NFS_OPTION_FSCACHE;
 548                 else
 549                         ctx->options |= NFS_OPTION_FSCACHE;
 550                 kfree(ctx->fscache_uniq);
 551                 ctx->fscache_uniq = NULL;
 552                 break;
 553         case Opt_fscache:
 554                 ctx->options |= NFS_OPTION_FSCACHE;
 555                 kfree(ctx->fscache_uniq);
 556                 ctx->fscache_uniq = param->string;
 557                 param->string = NULL;
 558                 break;
 559         case Opt_migration:
 560                 if (result.negated)
 561                         ctx->options &= ~NFS_OPTION_MIGRATION;
 562                 else
 563                         ctx->options |= NFS_OPTION_MIGRATION;
 564                 break;
 565
 566                 /*
 567                  * options that take numeric values
 568                  */
 569         case Opt_port:
 570                 if (result.uint_32 > USHRT_MAX)
 571                         goto out_of_bounds;
 572                 ctx->nfs_server.port = result.uint_32;
 573                 break;
 574         case Opt_rsize:
 575                 ctx->rsize = result.uint_32;
 576                 break;
 577         case Opt_wsize:
 578                 ctx->wsize = result.uint_32;
 579                 break;
 580         case Opt_bsize:
 581                 ctx->bsize = result.uint_32;
 582                 break;
 583         case Opt_timeo:
 584                 if (result.uint_32 < 1 || result.uint_32 > INT_MAX)
 585                         goto out_of_bounds;
 586                 ctx->timeo = result.uint_32;
 587                 break;
 588         case Opt_retrans:
 589                 if (result.uint_32 > INT_MAX)
 590                         goto out_of_bounds;
 591                 ctx->retrans = result.uint_32;
 592                 break;
 593         case Opt_acregmin:
 594                 ctx->acregmin = result.uint_32;
 595                 break;
 596         case Opt_acregmax:
 597                 ctx->acregmax = result.uint_32;
 598                 break;
 599         case Opt_acdirmin:
 600                 ctx->acdirmin = result.uint_32;
 601                 break;
 602         case Opt_acdirmax:
 603                 ctx->acdirmax = result.uint_32;
 604                 break;
 605         case Opt_actimeo:
 606                 ctx->acregmin = result.uint_32;
 607                 ctx->acregmax = result.uint_32;
 608                 ctx->acdirmin = result.uint_32;
 609                 ctx->acdirmax = result.uint_32;
 610                 break;
 611         case Opt_namelen:
 612                 ctx->namlen = result.uint_32;
 613                 break;
 614         case Opt_mountport:
 615                 if (result.uint_32 > USHRT_MAX)
 616                         goto out_of_bounds;
 617                 ctx->mount_server.port = result.uint_32;
 618                 break;
 619         case Opt_mountvers:
 620                 if (result.uint_32 < NFS_MNT_VERSION ||
 621                     result.uint_32 > NFS_MNT3_VERSION)
 622                         goto out_of_bounds;
 623                 ctx->mount_server.version = result.uint_32;
 624                 break;
 625         case Opt_minorversion:
 626                 if (result.uint_32 > NFS4_MAX_MINOR_VERSION)
 627                         goto out_of_bounds;
 628                 ctx->minorversion = result.uint_32;
 629                 break;
 630
 631                 /*
 632                  * options that take text values
 633                  */
 634         case Opt_v:
 635                 ret = nfs_parse_version_string(fc, param->key + 1);
 636                 if (ret < 0)
 637                         return ret;
 638                 break;
 639         case Opt_vers:
 640                 ret = nfs_parse_version_string(fc, param->string);
 641                 if (ret < 0)
 642                         return ret;
 643                 break;
 644         case Opt_sec:
 645                 ret = nfs_parse_security_flavors(fc, param);
 646                 if (ret < 0)
 647                         return ret;
 648                 break;
 649
 650         case Opt_proto:
 651                 protofamily = AF_INET;
 652                 switch (lookup_constant(nfs_xprt_protocol_tokens, param->string, -1)) {
 653                 case Opt_xprt_udp6:
 654                         protofamily = AF_INET6;
 655                         fallthrough;
 656                 case Opt_xprt_udp:
 657                         ctx->flags &= ~NFS_MOUNT_TCP;
 658                         ctx->nfs_server.protocol = XPRT_TRANSPORT_UDP;
 659                         break;
 660                 case Opt_xprt_tcp6:
 661                         protofamily = AF_INET6;
 662                         fallthrough;
 663                 case Opt_xprt_tcp:
 664                         ctx->flags |= NFS_MOUNT_TCP;
 665                         ctx->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 666                         break;
 667                 case Opt_xprt_rdma6:
 668                         protofamily = AF_INET6;
 669                         fallthrough;
 670                 case Opt_xprt_rdma:
 671                         /* vector side protocols to TCP */
 672                         ctx->flags |= NFS_MOUNT_TCP;
 673                         ctx->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
 674                         xprt_load_transport(param->string);
 675                         break;
 676                 default:
 677                         return nfs_invalf(fc, "NFS: Unrecognized transport protocol");
 678                 }
 679
 680                 ctx->protofamily = protofamily;
 681                 break;
 682
 683         case Opt_mountproto:
 684                 mountfamily = AF_INET;
 685                 switch (lookup_constant(nfs_xprt_protocol_tokens, param->string, -1)) {
 686                 case Opt_xprt_udp6:
 687                         mountfamily = AF_INET6;
 688                         fallthrough;
 689                 case Opt_xprt_udp:
 690                         ctx->mount_server.protocol = XPRT_TRANSPORT_UDP;
 691                         break;
 692                 case Opt_xprt_tcp6:
 693                         mountfamily = AF_INET6;
 694                         fallthrough;
 695                 case Opt_xprt_tcp:
 696                         ctx->mount_server.protocol = XPRT_TRANSPORT_TCP;
 697                         break;
 698                 case Opt_xprt_rdma: /* not used for side protocols */
 699                 default:
 700                         return nfs_invalf(fc, "NFS: Unrecognized transport protocol");
 701                 }
 702                 ctx->mountfamily = mountfamily;
 703                 break;
 704
 705         case Opt_addr:
 706                 len = rpc_pton(fc->net_ns, param->string, param->size,
 707                                &ctx->nfs_server.address,
 708                                sizeof(ctx->nfs_server._address));
 709                 if (len == 0)
 710                         goto out_invalid_address;
 711                 ctx->nfs_server.addrlen = len;
 712                 break;
 713         case Opt_clientaddr:
 714                 kfree(ctx->client_address);
 715                 ctx->client_address = param->string;
 716                 param->string = NULL;
 717                 break;
 718         case Opt_mounthost:
 719                 kfree(ctx->mount_server.hostname);
 720                 ctx->mount_server.hostname = param->string;
 721                 param->string = NULL;
 722                 break;
 723         case Opt_mountaddr:
 724                 len = rpc_pton(fc->net_ns, param->string, param->size,
 725                                &ctx->mount_server.address,
 726                                sizeof(ctx->mount_server._address));
 727                 if (len == 0)
 728                         goto out_invalid_address;
 729                 ctx->mount_server.addrlen = len;
 730                 break;
 731         case Opt_nconnect:
 732                 if (result.uint_32 < 1 || result.uint_32 > NFS_MAX_CONNECTIONS)
 733                         goto out_of_bounds;
 734                 ctx->nfs_server.nconnect = result.uint_32;
 735                 break;
 736         case Opt_lookupcache:
 737                 switch (result.uint_32) {
 738                 case Opt_lookupcache_all:
 739                         ctx->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
 740                         break;
 741                 case Opt_lookupcache_positive:
 742                         ctx->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
 743                         ctx->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
 744                         break;
 745                 case Opt_lookupcache_none:
 746                         ctx->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
 747                         break;
 748                 default:
 749                         goto out_invalid_value;
 750                 }
 751                 break;
 752         case Opt_local_lock:
 753                 switch (result.uint_32) {
 754                 case Opt_local_lock_all:
 755                         ctx->flags |= (NFS_MOUNT_LOCAL_FLOCK |
 756                                        NFS_MOUNT_LOCAL_FCNTL);
 757                         break;
 758                 case Opt_local_lock_flock:
 759                         ctx->flags |= NFS_MOUNT_LOCAL_FLOCK;
 760                         break;
 761                 case Opt_local_lock_posix:
 762                         ctx->flags |= NFS_MOUNT_LOCAL_FCNTL;
 763                         break;
 764                 case Opt_local_lock_none:
 765                         ctx->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
 766                                         NFS_MOUNT_LOCAL_FCNTL);
 767                         break;
 768                 default:
 769                         goto out_invalid_value;
 770                 }
 771                 break;
 772
 773                 /*
 774                  * Special options
 775                  */
 776         case Opt_sloppy:
 777                 ctx->sloppy = true;
 778                 dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
 779                 break;
 780         }
 781
 782         return 0;
 783
 784 out_invalid_value:
 785         return nfs_invalf(fc, "NFS: Bad mount option value specified");
 786 out_invalid_address:
 787         return nfs_invalf(fc, "NFS: Bad IP address specified");
 788 out_of_bounds:
 789         return nfs_invalf(fc, "NFS: Value for '%s' out of range", param->key);
 790 }
 791
 792 /*
 793  * Split fc->source into "hostname:export_path".
 794  *
 795  * The leftmost colon demarks the split between the server's hostname
 796  * and the export path.  If the hostname starts with a left square
 797  * bracket, then it may contain colons.
 798  *
 799  * Note: caller frees hostname and export path, even on error.
 800  */
 801 static int nfs_parse_source(struct fs_context *fc,
 802                             size_t maxnamlen, size_t maxpathlen)
 803 {
 804         struct nfs_fs_context *ctx = nfs_fc2context(fc);
 805         const char *dev_name = fc->source;
 806         size_t len;
 807         const char *end;
 808
 809         if (unlikely(!dev_name || !*dev_name)) {
 810                 dfprintk(MOUNT, "NFS: device name not specified\n");
 811                 return -EINVAL;
 812         }
 813
 814         /* Is the host name protected with square brakcets? */
 815         if (*dev_name == '[') {
 816                 end = strchr(++dev_name, ']');
 817                 if (end == NULL || end[1] != ':')
 818                         goto out_bad_devname;
 819
 820                 len = end - dev_name;
 821                 end++;
 822         } else {
 823                 const char *comma;
 824
 825                 end = strchr(dev_name, ':');
 826                 if (end == NULL)
 827                         goto out_bad_devname;
 828                 len = end - dev_name;
 829
 830                 /* kill possible hostname list: not supported */
 831                 comma = memchr(dev_name, ',', len);
 832                 if (comma)
 833                         len = comma - dev_name;
 834         }
 835
 836         if (len > maxnamlen)
 837                 goto out_hostname;
 838
 839         kfree(ctx->nfs_server.hostname);
 840
 841         /* N.B. caller will free nfs_server.hostname in all cases */
 842         ctx->nfs_server.hostname = kmemdup_nul(dev_name, len, GFP_KERNEL);
 843         if (!ctx->nfs_server.hostname)
 844                 goto out_nomem;
 845         len = strlen(++end);
 846         if (len > maxpathlen)
 847                 goto out_path;
 848         ctx->nfs_server.export_path = kmemdup_nul(end, len, GFP_KERNEL);
 849         if (!ctx->nfs_server.export_path)
 850                 goto out_nomem;
 851
 852         dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", ctx->nfs_server.export_path);
 853         return 0;
 854
 855 out_bad_devname:
 856         return nfs_invalf(fc, "NFS: device name not in host:path format");
 857 out_nomem:
 858         nfs_errorf(fc, "NFS: not enough memory to parse device name");
 859         return -ENOMEM;
 860 out_hostname:
 861         nfs_errorf(fc, "NFS: server hostname too long");
 862         return -ENAMETOOLONG;
 863 out_path:
 864         nfs_errorf(fc, "NFS: export pathname too long");
 865         return -ENAMETOOLONG;
 866 }
 867
 868 static inline bool is_remount_fc(struct fs_context *fc)
 869 {
 870         return fc->root != NULL;
 871 }
 872
 873 /*
 874  * Parse monolithic NFS2/NFS3 mount data
 875  * - fills in the mount root filehandle
 876  *
 877  * For option strings, user space handles the following behaviors:
 878  *
 879  * + DNS: mapping server host name to IP address ("addr=" option)
 880  *
 881  * + failure mode: how to behave if a mount request can't be handled
 882  *   immediately ("fg/bg" option)
 883  *
 884  * + retry: how often to retry a mount request ("retry=" option)
 885  *
 886  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
 887  *   mountproto=tcp after mountproto=udp, and so on
 888  */
 889 static int nfs23_parse_monolithic(struct fs_context *fc,
 890                                   struct nfs_mount_data *data)
 891 {
 892         struct nfs_fs_context *ctx = nfs_fc2context(fc);
 893         struct nfs_fh *mntfh = ctx->mntfh;
 894         struct sockaddr *sap = (struct sockaddr *)&ctx->nfs_server.address;
 895         int extra_flags = NFS_MOUNT_LEGACY_INTERFACE;
 896
 897         if (data == NULL)
 898                 goto out_no_data;
 899
 900         ctx->version = NFS_DEFAULT_VERSION;
 901         switch (data->version) {
 902         case 1:
 903                 data->namlen = 0;
 904                 fallthrough;
 905         case 2:
 906                 data->bsize = 0;
 907                 fallthrough;
 908         case 3:
 909                 if (data->flags & NFS_MOUNT_VER3)
 910                         goto out_no_v3;
 911                 data->root.size = NFS2_FHSIZE;
 912                 memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
 913                 /* Turn off security negotiation */
 914                 extra_flags |= NFS_MOUNT_SECFLAVOUR;
 915                 fallthrough;
 916         case 4:
 917                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
 918                         goto out_no_sec;
 919                 fallthrough;
 920         case 5:
 921                 memset(data->context, 0, sizeof(data->context));
 922                 fallthrough;
 923         case 6:
 924                 if (data->flags & NFS_MOUNT_VER3) {
 925                         if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
 926                                 goto out_invalid_fh;
 927                         mntfh->size = data->root.size;
 928                         ctx->version = 3;
 929                 } else {
 930                         mntfh->size = NFS2_FHSIZE;
 931                         ctx->version = 2;
 932                 }
 933
 934
 935                 memcpy(mntfh->data, data->root.data, mntfh->size);
 936                 if (mntfh->size < sizeof(mntfh->data))
 937                         memset(mntfh->data + mntfh->size, 0,
 938                                sizeof(mntfh->data) - mntfh->size);
 939
 940                 /*
 941                  * for proto == XPRT_TRANSPORT_UDP, which is what uses
 942                  * to_exponential, implying shift: limit the shift value
 943                  * to BITS_PER_LONG (majortimeo is unsigned long)
 944                  */
 945                 if (!(data->flags & NFS_MOUNT_TCP)) /* this will be UDP */
 946                         if (data->retrans >= 64) /* shift value is too large */
 947                                 goto out_invalid_data;
 948
 949                 /*
 950                  * Translate to nfs_fs_context, which nfs_fill_super
 951                  * can deal with.
 952                  */
 953                 ctx->flags      = data->flags & NFS_MOUNT_FLAGMASK;
 954                 ctx->flags      |= extra_flags;
 955                 ctx->rsize      = data->rsize;
 956                 ctx->wsize      = data->wsize;
 957                 ctx->timeo      = data->timeo;
 958                 ctx->retrans    = data->retrans;
 959                 ctx->acregmin   = data->acregmin;
 960                 ctx->acregmax   = data->acregmax;
 961                 ctx->acdirmin   = data->acdirmin;
 962                 ctx->acdirmax   = data->acdirmax;
 963                 ctx->need_mount = false;
 964
 965                 memcpy(sap, &data->addr, sizeof(data->addr));
 966                 ctx->nfs_server.addrlen = sizeof(data->addr);
 967                 ctx->nfs_server.port = ntohs(data->addr.sin_port);
 968                 if (sap->sa_family != AF_INET ||
 969                     !nfs_verify_server_address(sap))
 970                         goto out_no_address;
 971
 972                 if (!(data->flags & NFS_MOUNT_TCP))
 973                         ctx->nfs_server.protocol = XPRT_TRANSPORT_UDP;
 974                 /* N.B. caller will free nfs_server.hostname in all cases */
 975                 ctx->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
 976                 if (!ctx->nfs_server.hostname)
 977                         goto out_nomem;
 978
 979                 ctx->namlen             = data->namlen;
 980                 ctx->bsize              = data->bsize;
 981
 982                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
 983                         ctx->selected_flavor = data->pseudoflavor;
 984                 else
 985                         ctx->selected_flavor = RPC_AUTH_UNIX;
 986
 987                 if (!(data->flags & NFS_MOUNT_NONLM))
 988                         ctx->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
 989                                          NFS_MOUNT_LOCAL_FCNTL);
 990                 else
 991                         ctx->flags |= (NFS_MOUNT_LOCAL_FLOCK|
 992                                         NFS_MOUNT_LOCAL_FCNTL);
 993
 994                 /*
 995                  * The legacy version 6 binary mount data from userspace has a
 996                  * field used only to transport selinux information into the
 997                  * kernel.  To continue to support that functionality we
 998                  * have a touch of selinux knowledge here in the NFS code. The
 999                  * userspace code converted context=blah to just blah so we are
1000                  * converting back to the full string selinux understands.
1001                  */
1002                 if (data->context[0]){
1003 #ifdef CONFIG_SECURITY_SELINUX
1004                         int ret;
1005
1006                         data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1007                         ret = vfs_parse_fs_string(fc, "context",
1008                                                   data->context, strlen(data->context));
1009                         if (ret < 0)
1010                                 return ret;
1011 #else
1012                         return -EINVAL;
1013 #endif
1014                 }
1015
1016                 break;
1017         default:
1018                 goto generic;
1019         }
1020
1021         ctx->skip_reconfig_option_check = true;
1022         return 0;
1023
1024 generic:
1025         return generic_parse_monolithic(fc, data);
1026
1027 out_no_data:
1028         if (is_remount_fc(fc)) {
1029                 ctx->skip_reconfig_option_check = true;
1030                 return 0;
1031         }
1032         return nfs_invalf(fc, "NFS: mount program didn't pass any mount data");
1033
1034 out_no_v3:
1035         return nfs_invalf(fc, "NFS: nfs_mount_data version does not support v3");
1036
1037 out_no_sec:
1038         return nfs_invalf(fc, "NFS: nfs_mount_data version supports only AUTH_SYS");
1039
1040 out_nomem:
1041         dfprintk(MOUNT, "NFS: not enough memory to handle mount options");
1042         return -ENOMEM;
1043
1044 out_no_address:
1045         return nfs_invalf(fc, "NFS: mount program didn't pass remote address");
1046
1047 out_invalid_fh:
1048         return nfs_invalf(fc, "NFS: invalid root filehandle");
1049
1050 out_invalid_data:
1051         return nfs_invalf(fc, "NFS: invalid binary mount data");
1052 }
1053
1054 #if IS_ENABLED(CONFIG_NFS_V4)
1055 struct compat_nfs_string {
1056         compat_uint_t len;
1057         compat_uptr_t data;
1058 };
1059
1060 static inline void compat_nfs_string(struct nfs_string *dst,
1061                                      struct compat_nfs_string *src)
1062 {
1063         dst->data = compat_ptr(src->data);
1064         dst->len = src->len;
1065 }
1066
1067 struct compat_nfs4_mount_data_v1 {
1068         compat_int_t version;
1069         compat_int_t flags;
1070         compat_int_t rsize;
1071         compat_int_t wsize;
1072         compat_int_t timeo;
1073         compat_int_t retrans;
1074         compat_int_t acregmin;
1075         compat_int_t acregmax;
1076         compat_int_t acdirmin;
1077         compat_int_t acdirmax;
1078         struct compat_nfs_string client_addr;
1079         struct compat_nfs_string mnt_path;
1080         struct compat_nfs_string hostname;
1081         compat_uint_t host_addrlen;
1082         compat_uptr_t host_addr;
1083         compat_int_t proto;
1084         compat_int_t auth_flavourlen;
1085         compat_uptr_t auth_flavours;
1086 };
1087
1088 static void nfs4_compat_mount_data_conv(struct nfs4_mount_data *data)
1089 {
1090         struct compat_nfs4_mount_data_v1 *compat =
1091                         (struct compat_nfs4_mount_data_v1 *)data;
1092
1093         /* copy the fields backwards */
1094         data->auth_flavours = compat_ptr(compat->auth_flavours);
1095         data->auth_flavourlen = compat->auth_flavourlen;
1096         data->proto = compat->proto;
1097         data->host_addr = compat_ptr(compat->host_addr);
1098         data->host_addrlen = compat->host_addrlen;
1099         compat_nfs_string(&data->hostname, &compat->hostname);
1100         compat_nfs_string(&data->mnt_path, &compat->mnt_path);
1101         compat_nfs_string(&data->client_addr, &compat->client_addr);
1102         data->acdirmax = compat->acdirmax;
1103         data->acdirmin = compat->acdirmin;
1104         data->acregmax = compat->acregmax;
1105         data->acregmin = compat->acregmin;
1106         data->retrans = compat->retrans;
1107         data->timeo = compat->timeo;
1108         data->wsize = compat->wsize;
1109         data->rsize = compat->rsize;
1110         data->flags = compat->flags;
1111         data->version = compat->version;
1112 }
1113
1114 /*
1115  * Validate NFSv4 mount options
1116  */
1117 static int nfs4_parse_monolithic(struct fs_context *fc,
1118                                  struct nfs4_mount_data *data)
1119 {
1120         struct nfs_fs_context *ctx = nfs_fc2context(fc);
1121         struct sockaddr *sap = (struct sockaddr *)&ctx->nfs_server.address;
1122         char *c;
1123
1124         if (!data) {
1125                 if (is_remount_fc(fc))
1126                         goto done;
1127                 return nfs_invalf(fc,
1128                         "NFS4: mount program didn't pass any mount data");
1129         }
1130
1131         ctx->version = 4;
1132
1133         if (data->version != 1)
1134                 return generic_parse_monolithic(fc, data);
1135
1136         if (in_compat_syscall())
1137                 nfs4_compat_mount_data_conv(data);
1138
1139         if (data->host_addrlen > sizeof(ctx->nfs_server.address))
1140                 goto out_no_address;
1141         if (data->host_addrlen == 0)
1142                 goto out_no_address;
1143         ctx->nfs_server.addrlen = data->host_addrlen;
1144         if (copy_from_user(sap, data->host_addr, data->host_addrlen))
1145                 return -EFAULT;
1146         if (!nfs_verify_server_address(sap))
1147                 goto out_no_address;
1148         ctx->nfs_server.port = ntohs(((struct sockaddr_in *)sap)->sin_port);
1149
1150         if (data->auth_flavourlen) {
1151                 rpc_authflavor_t pseudoflavor;
1152
1153                 if (data->auth_flavourlen > 1)
1154                         goto out_inval_auth;
1155                 if (copy_from_user(&pseudoflavor, data->auth_flavours,
1156                                    sizeof(pseudoflavor)))
1157                         return -EFAULT;
1158                 ctx->selected_flavor = pseudoflavor;
1159         } else {
1160                 ctx->selected_flavor = RPC_AUTH_UNIX;
1161         }
1162
1163         c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
1164         if (IS_ERR(c))
1165                 return PTR_ERR(c);
1166         ctx->nfs_server.hostname = c;
1167
1168         c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
1169         if (IS_ERR(c))
1170                 return PTR_ERR(c);
1171         ctx->nfs_server.export_path = c;
1172         dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
1173
1174         c = strndup_user(data->client_addr.data, 16);
1175         if (IS_ERR(c))
1176                 return PTR_ERR(c);
1177         ctx->client_address = c;
1178
1179         /*
1180          * Translate to nfs_fs_context, which nfs_fill_super
1181          * can deal with.
1182          */
1183
1184         ctx->flags      = data->flags & NFS4_MOUNT_FLAGMASK;
1185         ctx->rsize      = data->rsize;
1186         ctx->wsize      = data->wsize;
1187         ctx->timeo      = data->timeo;
1188         ctx->retrans    = data->retrans;
1189         ctx->acregmin   = data->acregmin;
1190         ctx->acregmax   = data->acregmax;
1191         ctx->acdirmin   = data->acdirmin;
1192         ctx->acdirmax   = data->acdirmax;
1193         ctx->nfs_server.protocol = data->proto;
1194         nfs_validate_transport_protocol(ctx);
1195         if (ctx->nfs_server.protocol == XPRT_TRANSPORT_UDP)
1196                 goto out_invalid_transport_udp;
1197 done:
1198         ctx->skip_reconfig_option_check = true;
1199         return 0;
1200
1201 out_inval_auth:
1202         return nfs_invalf(fc, "NFS4: Invalid number of RPC auth flavours %d",
1203                       data->auth_flavourlen);
1204
1205 out_no_address:
1206         return nfs_invalf(fc, "NFS4: mount program didn't pass remote address");
1207
1208 out_invalid_transport_udp:
1209         return nfs_invalf(fc, "NFS: Unsupported transport protocol udp");
1210 }
1211 #endif
1212
1213 /*
1214  * Parse a monolithic block of data from sys_mount().
1215  */
1216 static int nfs_fs_context_parse_monolithic(struct fs_context *fc,
1217                                            void *data)
1218 {
1219         if (fc->fs_type == &nfs_fs_type)
1220                 return nfs23_parse_monolithic(fc, data);
1221
1222 #if IS_ENABLED(CONFIG_NFS_V4)
1223         if (fc->fs_type == &nfs4_fs_type)
1224                 return nfs4_parse_monolithic(fc, data);
1225 #endif
1226
1227         return nfs_invalf(fc, "NFS: Unsupported monolithic data version");
1228 }
1229
1230 /*
1231  * Validate the preparsed information in the config.
1232  */
1233 static int nfs_fs_context_validate(struct fs_context *fc)
1234 {
1235         struct nfs_fs_context *ctx = nfs_fc2context(fc);
1236         struct nfs_subversion *nfs_mod;
1237         struct sockaddr *sap = (struct sockaddr *)&ctx->nfs_server.address;
1238         int max_namelen = PAGE_SIZE;
1239         int max_pathlen = NFS_MAXPATHLEN;
1240         int port = 0;
1241         int ret;
1242
1243         if (!fc->source)
1244                 goto out_no_device_name;
1245
1246         /* Check for sanity first. */
1247         if (ctx->minorversion && ctx->version != 4)
1248                 goto out_minorversion_mismatch;
1249
1250         if (ctx->options & NFS_OPTION_MIGRATION &&
1251             (ctx->version != 4 || ctx->minorversion != 0))
1252                 goto out_migration_misuse;
1253
1254         /* Verify that any proto=/mountproto= options match the address
1255          * families in the addr=/mountaddr= options.
1256          */
1257         if (ctx->protofamily != AF_UNSPEC &&
1258             ctx->protofamily != ctx->nfs_server.address.sa_family)
1259                 goto out_proto_mismatch;
1260
1261         if (ctx->mountfamily != AF_UNSPEC) {
1262                 if (ctx->mount_server.addrlen) {
1263                         if (ctx->mountfamily != ctx->mount_server.address.sa_family)
1264                                 goto out_mountproto_mismatch;
1265                 } else {
1266                         if (ctx->mountfamily != ctx->nfs_server.address.sa_family)
1267                                 goto out_mountproto_mismatch;
1268                 }
1269         }
1270
1271         if (!nfs_verify_server_address(sap))
1272                 goto out_no_address;
1273
1274         if (ctx->version == 4) {
1275                 if (IS_ENABLED(CONFIG_NFS_V4)) {
1276                         if (ctx->nfs_server.protocol == XPRT_TRANSPORT_RDMA)
1277                                 port = NFS_RDMA_PORT;
1278                         else
1279                                 port = NFS_PORT;
1280                         max_namelen = NFS4_MAXNAMLEN;
1281                         max_pathlen = NFS4_MAXPATHLEN;
1282                         nfs_validate_transport_protocol(ctx);
1283                         if (ctx->nfs_server.protocol == XPRT_TRANSPORT_UDP)
1284                                 goto out_invalid_transport_udp;
1285                         ctx->flags &= ~(NFS_MOUNT_NONLM | NFS_MOUNT_NOACL |
1286                                         NFS_MOUNT_VER3 | NFS_MOUNT_LOCAL_FLOCK |
1287                                         NFS_MOUNT_LOCAL_FCNTL);
1288                 } else {
1289                         goto out_v4_not_compiled;
1290                 }
1291         } else {
1292                 nfs_set_mount_transport_protocol(ctx);
1293 #ifdef CONFIG_NFS_DISABLE_UDP_SUPPORT
1294                if (ctx->nfs_server.protocol == XPRT_TRANSPORT_UDP)
1295                        goto out_invalid_transport_udp;
1296 #endif
1297                 if (ctx->nfs_server.protocol == XPRT_TRANSPORT_RDMA)
1298                         port = NFS_RDMA_PORT;
1299         }
1300
1301         nfs_set_port(sap, &ctx->nfs_server.port, port);
1302
1303         ret = nfs_parse_source(fc, max_namelen, max_pathlen);
1304         if (ret < 0)
1305                 return ret;
1306
1307         /* Load the NFS protocol module if we haven't done so yet */
1308         if (!ctx->nfs_mod) {
1309                 nfs_mod = get_nfs_version(ctx->version);
1310                 if (IS_ERR(nfs_mod)) {
1311                         ret = PTR_ERR(nfs_mod);
1312                         goto out_version_unavailable;
1313                 }
1314                 ctx->nfs_mod = nfs_mod;
1315         }
1316
1317         /* Ensure the filesystem context has the correct fs_type */
1318         if (fc->fs_type != ctx->nfs_mod->nfs_fs) {
1319                 module_put(fc->fs_type->owner);
1320                 __module_get(ctx->nfs_mod->nfs_fs->owner);
1321                 fc->fs_type = ctx->nfs_mod->nfs_fs;
1322         }
1323         return 0;
1324
1325 out_no_device_name:
1326         return nfs_invalf(fc, "NFS: Device name not specified");
1327 out_v4_not_compiled:
1328         nfs_errorf(fc, "NFS: NFSv4 is not compiled into kernel");
1329         return -EPROTONOSUPPORT;
1330 out_invalid_transport_udp:
1331         return nfs_invalf(fc, "NFS: Unsupported transport protocol udp");
1332 out_no_address:
1333         return nfs_invalf(fc, "NFS: mount program didn't pass remote address");
1334 out_mountproto_mismatch:
1335         return nfs_invalf(fc, "NFS: Mount server address does not match mountproto= option");
1336 out_proto_mismatch:
1337         return nfs_invalf(fc, "NFS: Server address does not match proto= option");
1338 out_minorversion_mismatch:
1339         return nfs_invalf(fc, "NFS: Mount option vers=%u does not support minorversion=%u",
1340                           ctx->version, ctx->minorversion);
1341 out_migration_misuse:
1342         return nfs_invalf(fc, "NFS: 'Migration' not supported for this NFS version");
1343 out_version_unavailable:
1344         nfs_errorf(fc, "NFS: Version unavailable");
1345         return ret;
1346 }
1347
1348 /*
1349  * Create an NFS superblock by the appropriate method.
1350  */
1351 static int nfs_get_tree(struct fs_context *fc)
1352 {
1353         struct nfs_fs_context *ctx = nfs_fc2context(fc);
1354         int err = nfs_fs_context_validate(fc);
1355
1356         if (err)
1357                 return err;
1358         if (!ctx->internal)
1359                 return ctx->nfs_mod->rpc_ops->try_get_tree(fc);
1360         else
1361                 return nfs_get_tree_common(fc);
1362 }
1363
1364 /*
1365  * Handle duplication of a configuration.  The caller copied *src into *sc, but
1366  * it can't deal with resource pointers in the filesystem context, so we have
1367  * to do that.  We need to clear pointers, copy data or get extra refs as
1368  * appropriate.
1369  */
1370 static int nfs_fs_context_dup(struct fs_context *fc, struct fs_context *src_fc)
1371 {
1372         struct nfs_fs_context *src = nfs_fc2context(src_fc), *ctx;
1373
1374         ctx = kmemdup(src, sizeof(struct nfs_fs_context), GFP_KERNEL);
1375         if (!ctx)
1376                 return -ENOMEM;
1377
1378         ctx->mntfh = nfs_alloc_fhandle();
1379         if (!ctx->mntfh) {
1380                 kfree(ctx);
1381                 return -ENOMEM;
1382         }
1383         nfs_copy_fh(ctx->mntfh, src->mntfh);
1384
1385         __module_get(ctx->nfs_mod->owner);
1386         ctx->client_address             = NULL;
1387         ctx->mount_server.hostname      = NULL;
1388         ctx->nfs_server.export_path     = NULL;
1389         ctx->nfs_server.hostname        = NULL;
1390         ctx->fscache_uniq               = NULL;
1391         ctx->clone_data.fattr           = NULL;
1392         fc->fs_private = ctx;
1393         return 0;
1394 }
1395
1396 static void nfs_fs_context_free(struct fs_context *fc)
1397 {
1398         struct nfs_fs_context *ctx = nfs_fc2context(fc);
1399
1400         if (ctx) {
1401                 if (ctx->server)
1402                         nfs_free_server(ctx->server);
1403                 if (ctx->nfs_mod)
1404                         put_nfs_version(ctx->nfs_mod);
1405                 kfree(ctx->client_address);
1406                 kfree(ctx->mount_server.hostname);
1407                 kfree(ctx->nfs_server.export_path);
1408                 kfree(ctx->nfs_server.hostname);
1409                 kfree(ctx->fscache_uniq);
1410                 nfs_free_fhandle(ctx->mntfh);
1411                 nfs_free_fattr(ctx->clone_data.fattr);
1412                 kfree(ctx);
1413         }
1414 }
1415
1416 static const struct fs_context_operations nfs_fs_context_ops = {
1417         .free                   = nfs_fs_context_free,
1418         .dup                    = nfs_fs_context_dup,
1419         .parse_param            = nfs_fs_context_parse_param,
1420         .parse_monolithic       = nfs_fs_context_parse_monolithic,
1421         .get_tree               = nfs_get_tree,
1422         .reconfigure            = nfs_reconfigure,
1423 };
1424
1425 /*
1426  * Prepare superblock configuration.  We use the namespaces attached to the
1427  * context.  This may be the current process's namespaces, or it may be a
1428  * container's namespaces.
1429  */
1430 static int nfs_init_fs_context(struct fs_context *fc)
1431 {
1432         struct nfs_fs_context *ctx;
1433
1434         ctx = kzalloc(sizeof(struct nfs_fs_context), GFP_KERNEL);
1435         if (unlikely(!ctx))
1436                 return -ENOMEM;
1437
1438         ctx->mntfh = nfs_alloc_fhandle();
1439         if (unlikely(!ctx->mntfh)) {
1440                 kfree(ctx);
1441                 return -ENOMEM;
1442         }
1443
1444         ctx->protofamily        = AF_UNSPEC;
1445         ctx->mountfamily        = AF_UNSPEC;
1446         ctx->mount_server.port  = NFS_UNSPEC_PORT;
1447
1448         if (fc->root) {
1449                 /* reconfigure, start with the current config */
1450                 struct nfs_server *nfss = fc->root->d_sb->s_fs_info;
1451                 struct net *net = nfss->nfs_client->cl_net;
1452
1453                 ctx->flags              = nfss->flags;
1454                 ctx->rsize              = nfss->rsize;
1455                 ctx->wsize              = nfss->wsize;
1456                 ctx->retrans            = nfss->client->cl_timeout->to_retries;
1457                 ctx->selected_flavor    = nfss->client->cl_auth->au_flavor;
1458                 ctx->acregmin           = nfss->acregmin / HZ;
1459                 ctx->acregmax           = nfss->acregmax / HZ;
1460                 ctx->acdirmin           = nfss->acdirmin / HZ;
1461                 ctx->acdirmax           = nfss->acdirmax / HZ;
1462                 ctx->timeo              = 10U * nfss->client->cl_timeout->to_initval / HZ;
1463                 ctx->nfs_server.port    = nfss->port;
1464                 ctx->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
1465                 ctx->version            = nfss->nfs_client->rpc_ops->version;
1466                 ctx->minorversion       = nfss->nfs_client->cl_minorversion;
1467
1468                 memcpy(&ctx->nfs_server.address, &nfss->nfs_client->cl_addr,
1469                         ctx->nfs_server.addrlen);
1470
1471                 if (fc->net_ns != net) {
1472                         put_net(fc->net_ns);
1473                         fc->net_ns = get_net(net);
1474                 }
1475
1476                 ctx->nfs_mod = nfss->nfs_client->cl_nfs_mod;
1477                 __module_get(ctx->nfs_mod->owner);
1478         } else {
1479                 /* defaults */
1480                 ctx->timeo              = NFS_UNSPEC_TIMEO;
1481                 ctx->retrans            = NFS_UNSPEC_RETRANS;
1482                 ctx->acregmin           = NFS_DEF_ACREGMIN;
1483                 ctx->acregmax           = NFS_DEF_ACREGMAX;
1484                 ctx->acdirmin           = NFS_DEF_ACDIRMIN;
1485                 ctx->acdirmax           = NFS_DEF_ACDIRMAX;
1486                 ctx->nfs_server.port    = NFS_UNSPEC_PORT;
1487                 ctx->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1488                 ctx->selected_flavor    = RPC_AUTH_MAXFLAVOR;
1489                 ctx->minorversion       = 0;
1490                 ctx->need_mount         = true;
1491         }
1492         fc->fs_private = ctx;
1493         fc->ops = &nfs_fs_context_ops;
1494         return 0;
1495 }
1496
1497 struct file_system_type nfs_fs_type = {
1498         .owner                  = THIS_MODULE,
1499         .name                   = "nfs",
1500         .init_fs_context        = nfs_init_fs_context,
1501         .parameters             = nfs_fs_parameters,
1502         .kill_sb                = nfs_kill_super,
1503         .fs_flags               = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
1504 };
1505 MODULE_ALIAS_FS("nfs");
1506 EXPORT_SYMBOL_GPL(nfs_fs_type);
1507
1508 #if IS_ENABLED(CONFIG_NFS_V4)
1509 struct file_system_type nfs4_fs_type = {
1510         .owner                  = THIS_MODULE,
1511         .name                   = "nfs4",
1512         .init_fs_context        = nfs_init_fs_context,
1513         .parameters             = nfs_fs_parameters,
1514         .kill_sb                = nfs_kill_super,
1515         .fs_flags               = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
1516 };
1517 MODULE_ALIAS_FS("nfs4");
1518 MODULE_ALIAS("nfs4");
1519 EXPORT_SYMBOL_GPL(nfs4_fs_type);
1520 #endif /* CONFIG_NFS_V4 */