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