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 <[email protected]>
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/fs.h>
  15 #include <linux/fs_context.h>
  16 #include <linux/fs_parser.h>
  17 #include <linux/nfs_fs.h>
  18 #include <linux/nfs_mount.h>
  19 #include <linux/nfs4_mount.h>
  20 #include "nfs.h"
  21 #include "internal.h"
  22
  23 #define NFSDBG_FACILITY         NFSDBG_MOUNT
  24
  25 #if IS_ENABLED(CONFIG_NFS_V3)
  26 #define NFS_DEFAULT_VERSION 3
  27 #else
  28 #define NFS_DEFAULT_VERSION 2
  29 #endif
  30
  31 #define NFS_MAX_CONNECTIONS 16
  32
  33 enum nfs_param {
  34         Opt_ac,
  35         Opt_acdirmax,
  36         Opt_acdirmin,
  37         Opt_acl,
  38         Opt_acregmax,
  39         Opt_acregmin,
  40         Opt_actimeo,
  41         Opt_addr,
  42         Opt_bg,
  43         Opt_bsize,
  44         Opt_clientaddr,
  45         Opt_cto,
  46         Opt_fg,
  47         Opt_fscache,
  48         Opt_fscache_flag,
  49         Opt_hard,
  50         Opt_intr,
  51         Opt_local_lock,
  52         Opt_lock,
  53         Opt_lookupcache,
  54         Opt_migration,
  55         Opt_minorversion,
  56         Opt_mountaddr,
  57         Opt_mounthost,
  58         Opt_mountport,
  59         Opt_mountproto,
  60         Opt_mountvers,
  61         Opt_namelen,
  62         Opt_nconnect,
  63         Opt_port,
  64         Opt_posix,
  65         Opt_proto,
  66         Opt_rdirplus,
  67         Opt_rdma,
  68         Opt_resvport,
  69         Opt_retrans,
  70         Opt_retry,
  71         Opt_rsize,
  72         Opt_sec,
  73         Opt_sharecache,
  74         Opt_sloppy,
  75         Opt_soft,
  76         Opt_softerr,
  77         Opt_softreval,
  78         Opt_source,
  79         Opt_tcp,
  80         Opt_timeo,
  81         Opt_udp,
  82         Opt_v,
  83         Opt_vers,
  84         Opt_wsize,
  85         Opt_write,
  86 };
  87
  88 enum {
  89         Opt_local_lock_all,
  90         Opt_local_lock_flock,
  91         Opt_local_lock_none,
  92         Opt_local_lock_posix,
  93 };
  94
  95 static const struct constant_table nfs_param_enums_local_lock[] = {
  96         { "all",                Opt_local_lock_all },
  97         { "flock",      Opt_local_lock_flock },
  98         { "posix",      Opt_local_lock_posix },
  99         { "none",               Opt_local_lock_none },
 100         {}
 101 };
 102
 103 enum {
 104         Opt_lookupcache_all,
 105         Opt_lookupcache_none,
 106         Opt_lookupcache_positive,
 107 };
 108
 109 static const struct constant_table nfs_param_enums_lookupcache[] = {
 110         { "all",                Opt_lookupcache_all },
 111         { "none",               Opt_lookupcache_none },
 112         { "pos",                Opt_lookupcache_positive },
 113         { "positive",           Opt_lookupcache_positive },
 114         {}
 115 };
 116
 117 enum {
 118         Opt_write_lazy,
 119         Opt_write_eager,
 120         Opt_write_wait,
 121 };
 122
 123 static const struct constant_table nfs_param_enums_write[] = {
 124         { "lazy",               Opt_write_lazy },
 125         { "eager",              Opt_write_eager },
 126         { "wait",               Opt_write_wait },
 127         {}
 128 };
 129
 130 static const struct fs_parameter_spec nfs_fs_parameters[] = {
 131         fsparam_flag_no("ac",           Opt_ac),
 132         fsparam_u32   ("acdirmax",      Opt_acdirmax),
 133         fsparam_u32   ("acdirmin",      Opt_acdirmin),
 134         fsparam_flag_no("acl",          Opt_acl),
 135         fsparam_u32   ("acregmax",      Opt_acregmax),
 136         fsparam_u32   ("acregmin",      Opt_acregmin),
 137         fsparam_u32   ("actimeo",       Opt_actimeo),
 138         fsparam_string("addr",          Opt_addr),
 139         fsparam_flag  ("bg",            Opt_bg),
 140         fsparam_u32   ("bsize",         Opt_bsize),
 141         fsparam_string("clientaddr",    Opt_clientaddr),
 142         fsparam_flag_no("cto",          Opt_cto),
 143         fsparam_flag  ("fg",            Opt_fg),
 144         fsparam_flag_no("fsc",          Opt_fscache_flag),
 145         fsparam_string("fsc",           Opt_fscache),
 146         fsparam_flag  ("hard",          Opt_hard),
 147         __fsparam(NULL, "intr",         Opt_intr,
 148                   fs_param_neg_with_no|fs_param_deprecated, NULL),
 149         fsparam_enum  ("local_lock",    Opt_local_lock, nfs_param_enums_local_lock),
 150         fsparam_flag_no("lock",         Opt_lock),
 151         fsparam_enum  ("lookupcache",   Opt_lookupcache, nfs_param_enums_lookupcache),
 152         fsparam_flag_no("migration",    Opt_migration),
 153         fsparam_u32   ("minorversion",  Opt_minorversion),
 154         fsparam_string("mountaddr",     Opt_mountaddr),
 155         fsparam_string("mounthost",     Opt_mounthost),
 156         fsparam_u32   ("mountport",     Opt_mountport),
 157         fsparam_string("mountproto",    Opt_mountproto),
 158         fsparam_u32   ("mountvers",     Opt_mountvers),
 159         fsparam_u32   ("namlen",        Opt_namelen),
 160         fsparam_u32   ("nconnect",      Opt_nconnect),
 161         fsparam_string("nfsvers",       Opt_vers),
 162         fsparam_u32   ("port",          Opt_port),
 163         fsparam_flag_no("posix",        Opt_posix),
 164         fsparam_string("proto",         Opt_proto),
 165         fsparam_flag_no("rdirplus",     Opt_rdirplus),
 166         fsparam_flag  ("rdma",          Opt_rdma),
 167         fsparam_flag_no("resvport",     Opt_resvport),
 168         fsparam_u32   ("retrans",       Opt_retrans),
 169         fsparam_string("retry",         Opt_retry),
 170         fsparam_u32   ("rsize",         Opt_rsize),
 171         fsparam_string("sec",           Opt_sec),
 172         fsparam_flag_no("sharecache",   Opt_sharecache),
 173         fsparam_flag  ("sloppy",        Opt_sloppy),
 174         fsparam_flag  ("soft",          Opt_soft),
 175         fsparam_flag  ("softerr",       Opt_softerr),
 176         fsparam_flag  ("softreval",     Opt_softreval),
 177         fsparam_string("source",        Opt_source),
 178         fsparam_flag  ("tcp",           Opt_tcp),
 179         fsparam_u32   ("timeo",         Opt_timeo),
 180         fsparam_flag  ("udp",           Opt_udp),
 181         fsparam_flag  ("v2",            Opt_v),
 182         fsparam_flag  ("v3",            Opt_v),
 183         fsparam_flag  ("v4",            Opt_v),
 184         fsparam_flag  ("v4.0",          Opt_v),
 185         fsparam_flag  ("v4.1",          Opt_v),
 186         fsparam_flag  ("v4.2",          Opt_v),
 187         fsparam_string("vers",          Opt_vers),
 188         fsparam_enum  ("write",         Opt_write, nfs_param_enums_write),
 189         fsparam_u32   ("wsize",         Opt_wsize),
 190         {}
 191 };
 192
 193 enum {
 194         Opt_vers_2,
 195         Opt_vers_3,
 196         Opt_vers_4,
 197         Opt_vers_4_0,
 198         Opt_vers_4_1,
 199         Opt_vers_4_2,
 200 };
 201
 202 static const struct constant_table nfs_vers_tokens[] = {
 203         { "2",          Opt_vers_2 },
 204         { "3",          Opt_vers_3 },
 205         { "4",          Opt_vers_4 },
 206         { "4.0",        Opt_vers_4_0 },
 207         { "4.1",        Opt_vers_4_1 },
 208         { "4.2",        Opt_vers_4_2 },
 209         {}
 210 };
 211
 212 enum {
 213         Opt_xprt_rdma,
 214         Opt_xprt_rdma6,
 215         Opt_xprt_tcp,
 216         Opt_xprt_tcp6,
 217         Opt_xprt_udp,
 218         Opt_xprt_udp6,
 219         nr__Opt_xprt
 220 };
 221
 222 static const struct constant_table nfs_xprt_protocol_tokens[] = {
 223         { "rdma",       Opt_xprt_rdma },
 224         { "rdma6",      Opt_xprt_rdma6 },
 225         { "tcp",        Opt_xprt_tcp },
 226         { "tcp6",       Opt_xprt_tcp6 },
 227         { "udp",        Opt_xprt_udp },
 228         { "udp6",       Opt_xprt_udp6 },
 229         {}
 230 };
 231
 232 enum {
 233         Opt_sec_krb5,
 234         Opt_sec_krb5i,
 235         Opt_sec_krb5p,
 236         Opt_sec_lkey,
 237         Opt_sec_lkeyi,
 238         Opt_sec_lkeyp,
 239         Opt_sec_none,
 240         Opt_sec_spkm,
 241         Opt_sec_spkmi,
 242         Opt_sec_spkmp,
 243         Opt_sec_sys,
 244         nr__Opt_sec
 245 };
 246
 247 static const struct constant_table nfs_secflavor_tokens[] = {
 248         { "krb5",       Opt_sec_krb5 },
 249         { "krb5i",      Opt_sec_krb5i },
 250         { "krb5p",      Opt_sec_krb5p },
 251         { "lkey",       Opt_sec_lkey },
 252         { "lkeyi",      Opt_sec_lkeyi },
 253         { "lkeyp",      Opt_sec_lkeyp },
 254         { "none",       Opt_sec_none },
 255         { "null",       Opt_sec_none },
 256         { "spkm3",      Opt_sec_spkm },
 257         { "spkm3i",     Opt_sec_spkmi },
 258         { "spkm3p",     Opt_sec_spkmp },
 259         { "sys",        Opt_sec_sys },
 260         {}
 261 };
 262
 263 /*
 264  * Sanity-check a server address provided by the mount command.
 265  *
 266  * Address family must be initialized, and address must not be
 267  * the ANY address for that family.
 268  */
 269 static int nfs_verify_server_address(struct sockaddr *addr)
 270 {
 271         switch (addr->sa_family) {
 272         case AF_INET: {
 273                 struct sockaddr_in *sa = (struct sockaddr_in *)addr;
 274                 return sa->sin_addr.s_addr != htonl(INADDR_ANY);
 275         }
 276         case AF_INET6: {
 277                 struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
 278                 return !ipv6_addr_any(sa);
 279         }
 280         }
 281
 282         dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
 283         return 0;
 284 }
 285
 286 #ifdef CONFIG_NFS_DISABLE_UDP_SUPPORT
 287 static bool nfs_server_transport_udp_invalid(const struct nfs_fs_context *ctx)
 288 {
 289         return true;
 290 }
 291 #else
 292 static bool nfs_server_transport_udp_invalid(const struct nfs_fs_context *ctx)
 293 {
 294         if (ctx->version == 4)
 295                 return true;
 296         return false;
 297 }
 298 #endif
 299
 300 /*
 301  * Sanity check the NFS transport protocol.
 302  */
 303 static int nfs_validate_transport_protocol(struct fs_context *fc,
 304                                            struct nfs_fs_context *ctx)
 305 {
 306         switch (ctx->nfs_server.protocol) {
 307         case XPRT_TRANSPORT_UDP:
 308                 if (nfs_server_transport_udp_invalid(ctx))
 309                         goto out_invalid_transport_udp;
 310                 break;
 311         case XPRT_TRANSPORT_TCP:
 312         case XPRT_TRANSPORT_RDMA:
 313                 break;
 314         default:
 315                 ctx->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 316         }
 317         return 0;
 318 out_invalid_transport_udp:
 319         return nfs_invalf(fc, "NFS: Unsupported transport protocol udp");
 320 }
 321
 322 /*
 323  * For text based NFSv2/v3 mounts, the mount protocol transport default
 324  * settings should depend upon the specified NFS transport.
 325  */
 326 static void nfs_set_mount_transport_protocol(struct nfs_fs_context *ctx)
 327 {
 328         if (ctx->mount_server.protocol == XPRT_TRANSPORT_UDP ||
 329             ctx->mount_server.protocol == XPRT_TRANSPORT_TCP)
 330                         return;
 331         switch (ctx->nfs_server.protocol) {
 332         case XPRT_TRANSPORT_UDP:
 333                 ctx->mount_server.protocol = XPRT_TRANSPORT_UDP;
 334                 break;
 335         case XPRT_TRANSPORT_TCP:
 336         case XPRT_TRANSPORT_RDMA:
 337                 ctx->mount_server.protocol = XPRT_TRANSPORT_TCP;
 338         }
 339 }
 340
 341 /*
 342  * Add 'flavor' to 'auth_info' if not already present.
 343  * Returns true if 'flavor' ends up in the list, false otherwise
 344  */
 345 static int nfs_auth_info_add(struct fs_context *fc,
 346                              struct nfs_auth_info *auth_info,
 347                              rpc_authflavor_t flavor)
 348 {
 349         unsigned int i;
 350         unsigned int max_flavor_len = ARRAY_SIZE(auth_info->flavors);
 351
 352         /* make sure this flavor isn't already in the list */
 353         for (i = 0; i < auth_info->flavor_len; i++) {
 354                 if (flavor == auth_info->flavors[i])
 355                         return 0;
 356         }
 357
 358         if (auth_info->flavor_len + 1 >= max_flavor_len)
 359                 return nfs_invalf(fc, "NFS: too many sec= flavors");
 360
 361         auth_info->flavors[auth_info->flavor_len++] = flavor;
 362         return 0;
 363 }
 364
 365 /*
 366  * Parse the value of the 'sec=' option.
 367  */
 368 static int nfs_parse_security_flavors(struct fs_context *fc,
 369                                       struct fs_parameter *param)
 370 {
 371         struct nfs_fs_context *ctx = nfs_fc2context(fc);
 372         rpc_authflavor_t pseudoflavor;
 373         char *string = param->string, *p;
 374         int ret;
 375
 376         dfprintk(MOUNT, "NFS: parsing %s=%s option\n", param->key, param->string);
 377
 378         while ((p = strsep(&string, ":")) != NULL) {
 379                 if (!*p)
 380                         continue;
 381                 switch (lookup_constant(nfs_secflavor_tokens, p, -1)) {
 382                 case Opt_sec_none:
 383                         pseudoflavor = RPC_AUTH_NULL;
 384                         break;
 385                 case Opt_sec_sys:
 386                         pseudoflavor = RPC_AUTH_UNIX;
 387                         break;
 388                 case Opt_sec_krb5:
 389                         pseudoflavor = RPC_AUTH_GSS_KRB5;
 390                         break;
 391                 case Opt_sec_krb5i:
 392                         pseudoflavor = RPC_AUTH_GSS_KRB5I;
 393                         break;
 394                 case Opt_sec_krb5p:
 395                         pseudoflavor = RPC_AUTH_GSS_KRB5P;
 396                         break;
 397                 case Opt_sec_lkey:
 398                         pseudoflavor = RPC_AUTH_GSS_LKEY;
 399                         break;
 400                 case Opt_sec_lkeyi:
 401                         pseudoflavor = RPC_AUTH_GSS_LKEYI;
 402                         break;
 403                 case Opt_sec_lkeyp:
 404                         pseudoflavor = RPC_AUTH_GSS_LKEYP;
 405                         break;
 406                 case Opt_sec_spkm:
 407                         pseudoflavor = RPC_AUTH_GSS_SPKM;
 408                         break;
 409                 case Opt_sec_spkmi:
 410                         pseudoflavor = RPC_AUTH_GSS_SPKMI;
 411                         break;
 412                 case Opt_sec_spkmp:
 413                         pseudoflavor = RPC_AUTH_GSS_SPKMP;
 414                         break;
 415                 default:
 416                         return nfs_invalf(fc, "NFS: sec=%s option not recognized", p);
 417                 }
 418
 419                 ret = nfs_auth_info_add(fc, &ctx->auth_info, pseudoflavor);
 420                 if (ret < 0)
 421                         return ret;
 422         }
 423
 424         return 0;
 425 }
 426
 427 static int nfs_parse_version_string(struct fs_context *fc,
 428                                     const char *string)
 429 {
 430         struct nfs_fs_context *ctx = nfs_fc2context(fc);
 431
 432         ctx->flags &= ~NFS_MOUNT_VER3;
 433         switch (lookup_constant(nfs_vers_tokens, string, -1)) {
 434         case Opt_vers_2:
 435                 ctx->version = 2;
 436                 break;
 437         case Opt_vers_3:
 438                 ctx->flags |= NFS_MOUNT_VER3;
 439                 ctx->version = 3;
 440                 break;
 441         case Opt_vers_4:
 442                 /* Backward compatibility option. In future,
 443                  * the mount program should always supply
 444                  * a NFSv4 minor version number.
 445                  */
 446                 ctx->version = 4;
 447                 break;
 448         case Opt_vers_4_0:
 449                 ctx->version = 4;
 450                 ctx->minorversion = 0;
 451                 break;
 452         case Opt_vers_4_1:
 453                 ctx->version = 4;
 454                 ctx->minorversion = 1;
 455                 break;
 456         case Opt_vers_4_2:
 457                 ctx->version = 4;
 458                 ctx->minorversion = 2;
 459                 break;
 460         default:
 461                 return nfs_invalf(fc, "NFS: Unsupported NFS version");
 462         }
 463         return 0;
 464 }
 465
 466 /*
 467  * Parse a single mount parameter.
 468  */
 469 static int nfs_fs_context_parse_param(struct fs_context *fc,
 470                                       struct fs_parameter *param)
 471 {
 472         struct fs_parse_result result;
 473         struct nfs_fs_context *ctx = nfs_fc2context(fc);
 474         unsigned short protofamily, mountfamily;
 475         unsigned int len;
 476         int ret, opt;
 477
 478         dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", param->key);
 479
 480         opt = fs_parse(fc, nfs_fs_parameters, param, &result);
 481         if (opt < 0)
 482                 return ctx->sloppy ? 1 : opt;
 483
 484         if (fc->security)
 485                 ctx->has_sec_mnt_opts = 1;
 486
 487         switch (opt) {
 488         case Opt_source:
 489                 if (fc->source)
 490                         return nfs_invalf(fc, "NFS: Multiple sources not supported");
 491                 fc->source = param->string;
 492                 param->string = NULL;
 493                 break;
 494
 495                 /*
 496                  * boolean options:  foo/nofoo
 497                  */
 498         case Opt_soft:
 499                 ctx->flags |= NFS_MOUNT_SOFT;
 500                 ctx->flags &= ~NFS_MOUNT_SOFTERR;
 501                 break;
 502         case Opt_softerr:
 503                 ctx->flags |= NFS_MOUNT_SOFTERR | NFS_MOUNT_SOFTREVAL;
 504                 ctx->flags &= ~NFS_MOUNT_SOFT;
 505                 break;
 506         case Opt_hard:
 507                 ctx->flags &= ~(NFS_MOUNT_SOFT |
 508                                 NFS_MOUNT_SOFTERR |
 509                                 NFS_MOUNT_SOFTREVAL);
 510                 break;
 511         case Opt_softreval:
 512                 if (result.negated)
 513                         ctx->flags &= ~NFS_MOUNT_SOFTREVAL;
 514                 else
 515                         ctx->flags &= NFS_MOUNT_SOFTREVAL;
 516                 break;
 517         case Opt_posix:
 518                 if (result.negated)
 519                         ctx->flags &= ~NFS_MOUNT_POSIX;
 520                 else
 521                         ctx->flags |= NFS_MOUNT_POSIX;
 522                 break;
 523         case Opt_cto:
 524                 if (result.negated)
 525                         ctx->flags |= NFS_MOUNT_NOCTO;
 526                 else
 527                         ctx->flags &= ~NFS_MOUNT_NOCTO;
 528                 break;
 529         case Opt_ac:
 530                 if (result.negated)
 531                         ctx->flags |= NFS_MOUNT_NOAC;
 532                 else
 533                         ctx->flags &= ~NFS_MOUNT_NOAC;
 534                 break;
 535         case Opt_lock:
 536                 if (result.negated) {
 537                         ctx->flags |= NFS_MOUNT_NONLM;
 538                         ctx->flags |= (NFS_MOUNT_LOCAL_FLOCK | NFS_MOUNT_LOCAL_FCNTL);
 539                 } else {
 540                         ctx->flags &= ~NFS_MOUNT_NONLM;
 541                         ctx->flags &= ~(NFS_MOUNT_LOCAL_FLOCK | NFS_MOUNT_LOCAL_FCNTL);
 542                 }
 543                 break;
 544         case Opt_udp:
 545                 ctx->flags &= ~NFS_MOUNT_TCP;
 546                 ctx->nfs_server.protocol = XPRT_TRANSPORT_UDP;
 547                 break;
 548         case Opt_tcp:
 549         case Opt_rdma:
 550                 ctx->flags |= NFS_MOUNT_TCP; /* for side protocols */
 551                 ret = xprt_find_transport_ident(param->key);
 552                 if (ret < 0)
 553                         goto out_bad_transport;
 554                 ctx->nfs_server.protocol = ret;
 555                 break;
 556         case Opt_acl:
 557                 if (result.negated)
 558                         ctx->flags |= NFS_MOUNT_NOACL;
 559                 else
 560                         ctx->flags &= ~NFS_MOUNT_NOACL;
 561                 break;
 562         case Opt_rdirplus:
 563                 if (result.negated)
 564                         ctx->flags |= NFS_MOUNT_NORDIRPLUS;
 565                 else
 566                         ctx->flags &= ~NFS_MOUNT_NORDIRPLUS;
 567                 break;
 568         case Opt_sharecache:
 569                 if (result.negated)
 570                         ctx->flags |= NFS_MOUNT_UNSHARED;
 571                 else
 572                         ctx->flags &= ~NFS_MOUNT_UNSHARED;
 573                 break;
 574         case Opt_resvport:
 575                 if (result.negated)
 576                         ctx->flags |= NFS_MOUNT_NORESVPORT;
 577                 else
 578                         ctx->flags &= ~NFS_MOUNT_NORESVPORT;
 579                 break;
 580         case Opt_fscache_flag:
 581                 if (result.negated)
 582                         ctx->options &= ~NFS_OPTION_FSCACHE;
 583                 else
 584                         ctx->options |= NFS_OPTION_FSCACHE;
 585                 kfree(ctx->fscache_uniq);
 586                 ctx->fscache_uniq = NULL;
 587                 break;
 588         case Opt_fscache:
 589                 ctx->options |= NFS_OPTION_FSCACHE;
 590                 kfree(ctx->fscache_uniq);
 591                 ctx->fscache_uniq = param->string;
 592                 param->string = NULL;
 593                 break;
 594         case Opt_migration:
 595                 if (result.negated)
 596                         ctx->options &= ~NFS_OPTION_MIGRATION;
 597                 else
 598                         ctx->options |= NFS_OPTION_MIGRATION;
 599                 break;
 600
 601                 /*
 602                  * options that take numeric values
 603                  */
 604         case Opt_port:
 605                 if (result.uint_32 > USHRT_MAX)
 606                         goto out_of_bounds;
 607                 ctx->nfs_server.port = result.uint_32;
 608                 break;
 609         case Opt_rsize:
 610                 ctx->rsize = result.uint_32;
 611                 break;
 612         case Opt_wsize:
 613                 ctx->wsize = result.uint_32;
 614                 break;
 615         case Opt_bsize:
 616                 ctx->bsize = result.uint_32;
 617                 break;
 618         case Opt_timeo:
 619                 if (result.uint_32 < 1 || result.uint_32 > INT_MAX)
 620                         goto out_of_bounds;
 621                 ctx->timeo = result.uint_32;
 622                 break;
 623         case Opt_retrans:
 624                 if (result.uint_32 > INT_MAX)
 625                         goto out_of_bounds;
 626                 ctx->retrans = result.uint_32;
 627                 break;
 628         case Opt_acregmin:
 629                 ctx->acregmin = result.uint_32;
 630                 break;
 631         case Opt_acregmax:
 632                 ctx->acregmax = result.uint_32;
 633                 break;
 634         case Opt_acdirmin:
 635                 ctx->acdirmin = result.uint_32;
 636                 break;
 637         case Opt_acdirmax:
 638                 ctx->acdirmax = result.uint_32;
 639                 break;
 640         case Opt_actimeo:
 641                 ctx->acregmin = result.uint_32;
 642                 ctx->acregmax = result.uint_32;
 643                 ctx->acdirmin = result.uint_32;
 644                 ctx->acdirmax = result.uint_32;
 645                 break;
 646         case Opt_namelen:
 647                 ctx->namlen = result.uint_32;
 648                 break;
 649         case Opt_mountport:
 650                 if (result.uint_32 > USHRT_MAX)
 651                         goto out_of_bounds;
 652                 ctx->mount_server.port = result.uint_32;
 653                 break;
 654         case Opt_mountvers:
 655                 if (result.uint_32 < NFS_MNT_VERSION ||
 656                     result.uint_32 > NFS_MNT3_VERSION)
 657                         goto out_of_bounds;
 658                 ctx->mount_server.version = result.uint_32;
 659                 break;
 660         case Opt_minorversion:
 661                 if (result.uint_32 > NFS4_MAX_MINOR_VERSION)
 662                         goto out_of_bounds;
 663                 ctx->minorversion = result.uint_32;
 664                 break;
 665
 666                 /*
 667                  * options that take text values
 668                  */
 669         case Opt_v:
 670                 ret = nfs_parse_version_string(fc, param->key + 1);
 671                 if (ret < 0)
 672                         return ret;
 673                 break;
 674         case Opt_vers:
 675                 ret = nfs_parse_version_string(fc, param->string);
 676                 if (ret < 0)
 677                         return ret;
 678                 break;
 679         case Opt_sec:
 680                 ret = nfs_parse_security_flavors(fc, param);
 681                 if (ret < 0)
 682                         return ret;
 683                 break;
 684
 685         case Opt_proto:
 686                 protofamily = AF_INET;
 687                 switch (lookup_constant(nfs_xprt_protocol_tokens, param->string, -1)) {
 688                 case Opt_xprt_udp6:
 689                         protofamily = AF_INET6;
 690                         fallthrough;
 691                 case Opt_xprt_udp:
 692                         ctx->flags &= ~NFS_MOUNT_TCP;
 693                         ctx->nfs_server.protocol = XPRT_TRANSPORT_UDP;
 694                         break;
 695                 case Opt_xprt_tcp6:
 696                         protofamily = AF_INET6;
 697                         fallthrough;
 698                 case Opt_xprt_tcp:
 699                         ctx->flags |= NFS_MOUNT_TCP;
 700                         ctx->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 701                         break;
 702                 case Opt_xprt_rdma6:
 703                         protofamily = AF_INET6;
 704                         fallthrough;
 705                 case Opt_xprt_rdma:
 706                         /* vector side protocols to TCP */
 707                         ctx->flags |= NFS_MOUNT_TCP;
 708                         ret = xprt_find_transport_ident(param->string);
 709                         if (ret < 0)
 710                                 goto out_bad_transport;
 711                         ctx->nfs_server.protocol = ret;
 712                         break;
 713                 default:
 714                         goto out_bad_transport;
 715                 }
 716
 717                 ctx->protofamily = protofamily;
 718                 break;
 719
 720         case Opt_mountproto:
 721                 mountfamily = AF_INET;
 722                 switch (lookup_constant(nfs_xprt_protocol_tokens, param->string, -1)) {
 723                 case Opt_xprt_udp6:
 724                         mountfamily = AF_INET6;
 725                         fallthrough;
 726                 case Opt_xprt_udp:
 727                         ctx->mount_server.protocol = XPRT_TRANSPORT_UDP;
 728                         break;
 729                 case Opt_xprt_tcp6:
 730                         mountfamily = AF_INET6;
 731                         fallthrough;
 732                 case Opt_xprt_tcp:
 733                         ctx->mount_server.protocol = XPRT_TRANSPORT_TCP;
 734                         break;
 735                 case Opt_xprt_rdma: /* not used for side protocols */
 736                 default:
 737                         goto out_bad_transport;
 738                 }
 739                 ctx->mountfamily = mountfamily;
 740                 break;
 741
 742         case Opt_addr:
 743                 len = rpc_pton(fc->net_ns, param->string, param->size,
 744                                &ctx->nfs_server.address,
 745                                sizeof(ctx->nfs_server._address));
 746                 if (len == 0)
 747                         goto out_invalid_address;
 748                 ctx->nfs_server.addrlen = len;
 749                 break;
 750         case Opt_clientaddr:
 751                 kfree(ctx->client_address);
 752                 ctx->client_address = param->string;
 753                 param->string = NULL;
 754                 break;
 755         case Opt_mounthost:
 756                 kfree(ctx->mount_server.hostname);
 757                 ctx->mount_server.hostname = param->string;
 758                 param->string = NULL;
 759                 break;
 760         case Opt_mountaddr:
 761                 len = rpc_pton(fc->net_ns, param->string, param->size,
 762                                &ctx->mount_server.address,
 763                                sizeof(ctx->mount_server._address));
 764                 if (len == 0)
 765                         goto out_invalid_address;
 766                 ctx->mount_server.addrlen = len;
 767                 break;
 768         case Opt_nconnect:
 769                 if (result.uint_32 < 1 || result.uint_32 > NFS_MAX_CONNECTIONS)
 770                         goto out_of_bounds;
 771                 ctx->nfs_server.nconnect = result.uint_32;
 772                 break;
 773         case Opt_lookupcache:
 774                 switch (result.uint_32) {
 775                 case Opt_lookupcache_all:
 776                         ctx->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
 777                         break;
 778                 case Opt_lookupcache_positive:
 779                         ctx->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
 780                         ctx->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
 781                         break;
 782                 case Opt_lookupcache_none:
 783                         ctx->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
 784                         break;
 785                 default:
 786                         goto out_invalid_value;
 787                 }
 788                 break;
 789         case Opt_local_lock:
 790                 switch (result.uint_32) {
 791                 case Opt_local_lock_all:
 792                         ctx->flags |= (NFS_MOUNT_LOCAL_FLOCK |
 793                                        NFS_MOUNT_LOCAL_FCNTL);
 794                         break;
 795                 case Opt_local_lock_flock:
 796                         ctx->flags |= NFS_MOUNT_LOCAL_FLOCK;
 797                         break;
 798                 case Opt_local_lock_posix:
 799                         ctx->flags |= NFS_MOUNT_LOCAL_FCNTL;
 800                         break;
 801                 case Opt_local_lock_none:
 802                         ctx->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
 803                                         NFS_MOUNT_LOCAL_FCNTL);
 804                         break;
 805                 default:
 806                         goto out_invalid_value;
 807                 }
 808                 break;
 809         case Opt_write:
 810                 switch (result.uint_32) {
 811                 case Opt_write_lazy:
 812                         ctx->flags &=
 813                                 ~(NFS_MOUNT_WRITE_EAGER | NFS_MOUNT_WRITE_WAIT);
 814                         break;
 815                 case Opt_write_eager:
 816                         ctx->flags |= NFS_MOUNT_WRITE_EAGER;
 817                         ctx->flags &= ~NFS_MOUNT_WRITE_WAIT;
 818                         break;
 819                 case Opt_write_wait:
 820                         ctx->flags |=
 821                                 NFS_MOUNT_WRITE_EAGER | NFS_MOUNT_WRITE_WAIT;
 822                         break;
 823                 default:
 824                         goto out_invalid_value;
 825                 }
 826                 break;
 827
 828                 /*
 829                  * Special options
 830                  */
 831         case Opt_sloppy:
 832                 ctx->sloppy = true;
 833                 dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
 834                 break;
 835         }
 836
 837         return 0;
 838
 839 out_invalid_value:
 840         return nfs_invalf(fc, "NFS: Bad mount option value specified");
 841 out_invalid_address:
 842         return nfs_invalf(fc, "NFS: Bad IP address specified");
 843 out_of_bounds:
 844         return nfs_invalf(fc, "NFS: Value for '%s' out of range", param->key);
 845 out_bad_transport:
 846         return nfs_invalf(fc, "NFS: Unrecognized transport protocol");
 847 }
 848
 849 /*
 850  * Split fc->source into "hostname:export_path".
 851  *
 852  * The leftmost colon demarks the split between the server's hostname
 853  * and the export path.  If the hostname starts with a left square
 854  * bracket, then it may contain colons.
 855  *
 856  * Note: caller frees hostname and export path, even on error.
 857  */
 858 static int nfs_parse_source(struct fs_context *fc,
 859                             size_t maxnamlen, size_t maxpathlen)
 860 {
 861         struct nfs_fs_context *ctx = nfs_fc2context(fc);
 862         const char *dev_name = fc->source;
 863         size_t len;
 864         const char *end;
 865
 866         if (unlikely(!dev_name || !*dev_name)) {
 867                 dfprintk(MOUNT, "NFS: device name not specified\n");
 868                 return -EINVAL;
 869         }
 870
 871         /* Is the host name protected with square brakcets? */
 872         if (*dev_name == '[') {
 873                 end = strchr(++dev_name, ']');
 874                 if (end == NULL || end[1] != ':')
 875                         goto out_bad_devname;
 876
 877                 len = end - dev_name;
 878                 end++;
 879         } else {
 880                 const char *comma;
 881
 882                 end = strchr(dev_name, ':');
 883                 if (end == NULL)
 884                         goto out_bad_devname;
 885                 len = end - dev_name;
 886
 887                 /* kill possible hostname list: not supported */
 888                 comma = memchr(dev_name, ',', len);
 889                 if (comma)
 890                         len = comma - dev_name;
 891         }
 892
 893         if (len > maxnamlen)
 894                 goto out_hostname;
 895
 896         kfree(ctx->nfs_server.hostname);
 897
 898         /* N.B. caller will free nfs_server.hostname in all cases */
 899         ctx->nfs_server.hostname = kmemdup_nul(dev_name, len, GFP_KERNEL);
 900         if (!ctx->nfs_server.hostname)
 901                 goto out_nomem;
 902         len = strlen(++end);
 903         if (len > maxpathlen)
 904                 goto out_path;
 905         ctx->nfs_server.export_path = kmemdup_nul(end, len, GFP_KERNEL);
 906         if (!ctx->nfs_server.export_path)
 907                 goto out_nomem;
 908
 909         dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", ctx->nfs_server.export_path);
 910         return 0;
 911
 912 out_bad_devname:
 913         return nfs_invalf(fc, "NFS: device name not in host:path format");
 914 out_nomem:
 915         nfs_errorf(fc, "NFS: not enough memory to parse device name");
 916         return -ENOMEM;
 917 out_hostname:
 918         nfs_errorf(fc, "NFS: server hostname too long");
 919         return -ENAMETOOLONG;
 920 out_path:
 921         nfs_errorf(fc, "NFS: export pathname too long");
 922         return -ENAMETOOLONG;
 923 }
 924
 925 static inline bool is_remount_fc(struct fs_context *fc)
 926 {
 927         return fc->root != NULL;
 928 }
 929
 930 /*
 931  * Parse monolithic NFS2/NFS3 mount data
 932  * - fills in the mount root filehandle
 933  *
 934  * For option strings, user space handles the following behaviors:
 935  *
 936  * + DNS: mapping server host name to IP address ("addr=" option)
 937  *
 938  * + failure mode: how to behave if a mount request can't be handled
 939  *   immediately ("fg/bg" option)
 940  *
 941  * + retry: how often to retry a mount request ("retry=" option)
 942  *
 943  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
 944  *   mountproto=tcp after mountproto=udp, and so on
 945  */
 946 static int nfs23_parse_monolithic(struct fs_context *fc,
 947                                   struct nfs_mount_data *data)
 948 {
 949         struct nfs_fs_context *ctx = nfs_fc2context(fc);
 950         struct nfs_fh *mntfh = ctx->mntfh;
 951         struct sockaddr *sap = (struct sockaddr *)&ctx->nfs_server.address;
 952         int extra_flags = NFS_MOUNT_LEGACY_INTERFACE;
 953         int ret;
 954
 955         if (data == NULL)
 956                 goto out_no_data;
 957
 958         ctx->version = NFS_DEFAULT_VERSION;
 959         switch (data->version) {
 960         case 1:
 961                 data->namlen = 0;
 962                 fallthrough;
 963         case 2:
 964                 data->bsize = 0;
 965                 fallthrough;
 966         case 3:
 967                 if (data->flags & NFS_MOUNT_VER3)
 968                         goto out_no_v3;
 969                 data->root.size = NFS2_FHSIZE;
 970                 memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
 971                 /* Turn off security negotiation */
 972                 extra_flags |= NFS_MOUNT_SECFLAVOUR;
 973                 fallthrough;
 974         case 4:
 975                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
 976                         goto out_no_sec;
 977                 fallthrough;
 978         case 5:
 979                 memset(data->context, 0, sizeof(data->context));
 980                 fallthrough;
 981         case 6:
 982                 if (data->flags & NFS_MOUNT_VER3) {
 983                         if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
 984                                 goto out_invalid_fh;
 985                         mntfh->size = data->root.size;
 986                         ctx->version = 3;
 987                 } else {
 988                         mntfh->size = NFS2_FHSIZE;
 989                         ctx->version = 2;
 990                 }
 991
 992
 993                 memcpy(mntfh->data, data->root.data, mntfh->size);
 994                 if (mntfh->size < sizeof(mntfh->data))
 995                         memset(mntfh->data + mntfh->size, 0,
 996                                sizeof(mntfh->data) - mntfh->size);
 997
 998                 /*
 999                  * for proto == XPRT_TRANSPORT_UDP, which is what uses
1000                  * to_exponential, implying shift: limit the shift value
1001                  * to BITS_PER_LONG (majortimeo is unsigned long)
1002                  */
1003                 if (!(data->flags & NFS_MOUNT_TCP)) /* this will be UDP */
1004                         if (data->retrans >= 64) /* shift value is too large */
1005                                 goto out_invalid_data;
1006
1007                 /*
1008                  * Translate to nfs_fs_context, which nfs_fill_super
1009                  * can deal with.
1010                  */
1011                 ctx->flags      = data->flags & NFS_MOUNT_FLAGMASK;
1012                 ctx->flags      |= extra_flags;
1013                 ctx->rsize      = data->rsize;
1014                 ctx->wsize      = data->wsize;
1015                 ctx->timeo      = data->timeo;
1016                 ctx->retrans    = data->retrans;
1017                 ctx->acregmin   = data->acregmin;
1018                 ctx->acregmax   = data->acregmax;
1019                 ctx->acdirmin   = data->acdirmin;
1020                 ctx->acdirmax   = data->acdirmax;
1021                 ctx->need_mount = false;
1022
1023                 memcpy(sap, &data->addr, sizeof(data->addr));
1024                 ctx->nfs_server.addrlen = sizeof(data->addr);
1025                 ctx->nfs_server.port = ntohs(data->addr.sin_port);
1026                 if (sap->sa_family != AF_INET ||
1027                     !nfs_verify_server_address(sap))
1028                         goto out_no_address;
1029
1030                 if (!(data->flags & NFS_MOUNT_TCP))
1031                         ctx->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1032                 /* N.B. caller will free nfs_server.hostname in all cases */
1033                 ctx->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1034                 if (!ctx->nfs_server.hostname)
1035                         goto out_nomem;
1036
1037                 ctx->namlen             = data->namlen;
1038                 ctx->bsize              = data->bsize;
1039
1040                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1041                         ctx->selected_flavor = data->pseudoflavor;
1042                 else
1043                         ctx->selected_flavor = RPC_AUTH_UNIX;
1044
1045                 if (!(data->flags & NFS_MOUNT_NONLM))
1046                         ctx->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
1047                                          NFS_MOUNT_LOCAL_FCNTL);
1048                 else
1049                         ctx->flags |= (NFS_MOUNT_LOCAL_FLOCK|
1050                                         NFS_MOUNT_LOCAL_FCNTL);
1051
1052                 /*
1053                  * The legacy version 6 binary mount data from userspace has a
1054                  * field used only to transport selinux information into the
1055                  * kernel.  To continue to support that functionality we
1056                  * have a touch of selinux knowledge here in the NFS code. The
1057                  * userspace code converted context=blah to just blah so we are
1058                  * converting back to the full string selinux understands.
1059                  */
1060                 if (data->context[0]){
1061 #ifdef CONFIG_SECURITY_SELINUX
1062                         int ret;
1063
1064                         data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1065                         ret = vfs_parse_fs_string(fc, "context",
1066                                                   data->context, strlen(data->context));
1067                         if (ret < 0)
1068                                 return ret;
1069 #else
1070                         return -EINVAL;
1071 #endif
1072                 }
1073
1074                 break;
1075         default:
1076                 goto generic;
1077         }
1078
1079         ret = nfs_validate_transport_protocol(fc, ctx);
1080         if (ret)
1081                 return ret;
1082
1083         ctx->skip_reconfig_option_check = true;
1084         return 0;
1085
1086 generic:
1087         return generic_parse_monolithic(fc, data);
1088
1089 out_no_data:
1090         if (is_remount_fc(fc)) {
1091                 ctx->skip_reconfig_option_check = true;
1092                 return 0;
1093         }
1094         return nfs_invalf(fc, "NFS: mount program didn't pass any mount data");
1095
1096 out_no_v3:
1097         return nfs_invalf(fc, "NFS: nfs_mount_data version does not support v3");
1098
1099 out_no_sec:
1100         return nfs_invalf(fc, "NFS: nfs_mount_data version supports only AUTH_SYS");
1101
1102 out_nomem:
1103         dfprintk(MOUNT, "NFS: not enough memory to handle mount options");
1104         return -ENOMEM;
1105
1106 out_no_address:
1107         return nfs_invalf(fc, "NFS: mount program didn't pass remote address");
1108
1109 out_invalid_fh:
1110         return nfs_invalf(fc, "NFS: invalid root filehandle");
1111
1112 out_invalid_data:
1113         return nfs_invalf(fc, "NFS: invalid binary mount data");
1114 }
1115
1116 #if IS_ENABLED(CONFIG_NFS_V4)
1117 struct compat_nfs_string {
1118         compat_uint_t len;
1119         compat_uptr_t data;
1120 };
1121
1122 static inline void compat_nfs_string(struct nfs_string *dst,
1123                                      struct compat_nfs_string *src)
1124 {
1125         dst->data = compat_ptr(src->data);
1126         dst->len = src->len;
1127 }
1128
1129 struct compat_nfs4_mount_data_v1 {
1130         compat_int_t version;
1131         compat_int_t flags;
1132         compat_int_t rsize;
1133         compat_int_t wsize;
1134         compat_int_t timeo;
1135         compat_int_t retrans;
1136         compat_int_t acregmin;
1137         compat_int_t acregmax;
1138         compat_int_t acdirmin;
1139         compat_int_t acdirmax;
1140         struct compat_nfs_string client_addr;
1141         struct compat_nfs_string mnt_path;
1142         struct compat_nfs_string hostname;
1143         compat_uint_t host_addrlen;
1144         compat_uptr_t host_addr;
1145         compat_int_t proto;
1146         compat_int_t auth_flavourlen;
1147         compat_uptr_t auth_flavours;
1148 };
1149
1150 static void nfs4_compat_mount_data_conv(struct nfs4_mount_data *data)
1151 {
1152         struct compat_nfs4_mount_data_v1 *compat =
1153                         (struct compat_nfs4_mount_data_v1 *)data;
1154
1155         /* copy the fields backwards */
1156         data->auth_flavours = compat_ptr(compat->auth_flavours);
1157         data->auth_flavourlen = compat->auth_flavourlen;
1158         data->proto = compat->proto;
1159         data->host_addr = compat_ptr(compat->host_addr);
1160         data->host_addrlen = compat->host_addrlen;
1161         compat_nfs_string(&data->hostname, &compat->hostname);
1162         compat_nfs_string(&data->mnt_path, &compat->mnt_path);
1163         compat_nfs_string(&data->client_addr, &compat->client_addr);
1164         data->acdirmax = compat->acdirmax;
1165         data->acdirmin = compat->acdirmin;
1166         data->acregmax = compat->acregmax;
1167         data->acregmin = compat->acregmin;
1168         data->retrans = compat->retrans;
1169         data->timeo = compat->timeo;
1170         data->wsize = compat->wsize;
1171         data->rsize = compat->rsize;
1172         data->flags = compat->flags;
1173         data->version = compat->version;
1174 }
1175
1176 /*
1177  * Validate NFSv4 mount options
1178  */
1179 static int nfs4_parse_monolithic(struct fs_context *fc,
1180                                  struct nfs4_mount_data *data)
1181 {
1182         struct nfs_fs_context *ctx = nfs_fc2context(fc);
1183         struct sockaddr *sap = (struct sockaddr *)&ctx->nfs_server.address;
1184         int ret;
1185         char *c;
1186
1187         if (!data) {
1188                 if (is_remount_fc(fc))
1189                         goto done;
1190                 return nfs_invalf(fc,
1191                         "NFS4: mount program didn't pass any mount data");
1192         }
1193
1194         ctx->version = 4;
1195
1196         if (data->version != 1)
1197                 return generic_parse_monolithic(fc, data);
1198
1199         if (in_compat_syscall())
1200                 nfs4_compat_mount_data_conv(data);
1201
1202         if (data->host_addrlen > sizeof(ctx->nfs_server.address))
1203                 goto out_no_address;
1204         if (data->host_addrlen == 0)
1205                 goto out_no_address;
1206         ctx->nfs_server.addrlen = data->host_addrlen;
1207         if (copy_from_user(sap, data->host_addr, data->host_addrlen))
1208                 return -EFAULT;
1209         if (!nfs_verify_server_address(sap))
1210                 goto out_no_address;
1211         ctx->nfs_server.port = ntohs(((struct sockaddr_in *)sap)->sin_port);
1212
1213         if (data->auth_flavourlen) {
1214                 rpc_authflavor_t pseudoflavor;
1215
1216                 if (data->auth_flavourlen > 1)
1217                         goto out_inval_auth;
1218                 if (copy_from_user(&pseudoflavor, data->auth_flavours,
1219                                    sizeof(pseudoflavor)))
1220                         return -EFAULT;
1221                 ctx->selected_flavor = pseudoflavor;
1222         } else {
1223                 ctx->selected_flavor = RPC_AUTH_UNIX;
1224         }
1225
1226         c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
1227         if (IS_ERR(c))
1228                 return PTR_ERR(c);
1229         ctx->nfs_server.hostname = c;
1230
1231         c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
1232         if (IS_ERR(c))
1233                 return PTR_ERR(c);
1234         ctx->nfs_server.export_path = c;
1235         dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
1236
1237         c = strndup_user(data->client_addr.data, 16);
1238         if (IS_ERR(c))
1239                 return PTR_ERR(c);
1240         ctx->client_address = c;
1241
1242         /*
1243          * Translate to nfs_fs_context, which nfs_fill_super
1244          * can deal with.
1245          */
1246
1247         ctx->flags      = data->flags & NFS4_MOUNT_FLAGMASK;
1248         ctx->rsize      = data->rsize;
1249         ctx->wsize      = data->wsize;
1250         ctx->timeo      = data->timeo;
1251         ctx->retrans    = data->retrans;
1252         ctx->acregmin   = data->acregmin;
1253         ctx->acregmax   = data->acregmax;
1254         ctx->acdirmin   = data->acdirmin;
1255         ctx->acdirmax   = data->acdirmax;
1256         ctx->nfs_server.protocol = data->proto;
1257         ret = nfs_validate_transport_protocol(fc, ctx);
1258         if (ret)
1259                 return ret;
1260 done:
1261         ctx->skip_reconfig_option_check = true;
1262         return 0;
1263
1264 out_inval_auth:
1265         return nfs_invalf(fc, "NFS4: Invalid number of RPC auth flavours %d",
1266                       data->auth_flavourlen);
1267
1268 out_no_address:
1269         return nfs_invalf(fc, "NFS4: mount program didn't pass remote address");
1270 }
1271 #endif
1272
1273 /*
1274  * Parse a monolithic block of data from sys_mount().
1275  */
1276 static int nfs_fs_context_parse_monolithic(struct fs_context *fc,
1277                                            void *data)
1278 {
1279         if (fc->fs_type == &nfs_fs_type)
1280                 return nfs23_parse_monolithic(fc, data);
1281
1282 #if IS_ENABLED(CONFIG_NFS_V4)
1283         if (fc->fs_type == &nfs4_fs_type)
1284                 return nfs4_parse_monolithic(fc, data);
1285 #endif
1286
1287         return nfs_invalf(fc, "NFS: Unsupported monolithic data version");
1288 }
1289
1290 /*
1291  * Validate the preparsed information in the config.
1292  */
1293 static int nfs_fs_context_validate(struct fs_context *fc)
1294 {
1295         struct nfs_fs_context *ctx = nfs_fc2context(fc);
1296         struct nfs_subversion *nfs_mod;
1297         struct sockaddr *sap = (struct sockaddr *)&ctx->nfs_server.address;
1298         int max_namelen = PAGE_SIZE;
1299         int max_pathlen = NFS_MAXPATHLEN;
1300         int port = 0;
1301         int ret;
1302
1303         if (!fc->source)
1304                 goto out_no_device_name;
1305
1306         /* Check for sanity first. */
1307         if (ctx->minorversion && ctx->version != 4)
1308                 goto out_minorversion_mismatch;
1309
1310         if (ctx->options & NFS_OPTION_MIGRATION &&
1311             (ctx->version != 4 || ctx->minorversion != 0))
1312                 goto out_migration_misuse;
1313
1314         /* Verify that any proto=/mountproto= options match the address
1315          * families in the addr=/mountaddr= options.
1316          */
1317         if (ctx->protofamily != AF_UNSPEC &&
1318             ctx->protofamily != ctx->nfs_server.address.sa_family)
1319                 goto out_proto_mismatch;
1320
1321         if (ctx->mountfamily != AF_UNSPEC) {
1322                 if (ctx->mount_server.addrlen) {
1323                         if (ctx->mountfamily != ctx->mount_server.address.sa_family)
1324                                 goto out_mountproto_mismatch;
1325                 } else {
1326                         if (ctx->mountfamily != ctx->nfs_server.address.sa_family)
1327                                 goto out_mountproto_mismatch;
1328                 }
1329         }
1330
1331         if (!nfs_verify_server_address(sap))
1332                 goto out_no_address;
1333
1334         ret = nfs_validate_transport_protocol(fc, ctx);
1335         if (ret)
1336                 return ret;
1337
1338         if (ctx->version == 4) {
1339                 if (IS_ENABLED(CONFIG_NFS_V4)) {
1340                         if (ctx->nfs_server.protocol == XPRT_TRANSPORT_RDMA)
1341                                 port = NFS_RDMA_PORT;
1342                         else
1343                                 port = NFS_PORT;
1344                         max_namelen = NFS4_MAXNAMLEN;
1345                         max_pathlen = NFS4_MAXPATHLEN;
1346                         ctx->flags &= ~(NFS_MOUNT_NONLM | NFS_MOUNT_NOACL |
1347                                         NFS_MOUNT_VER3 | NFS_MOUNT_LOCAL_FLOCK |
1348                                         NFS_MOUNT_LOCAL_FCNTL);
1349                 } else {
1350                         goto out_v4_not_compiled;
1351                 }
1352         } else {
1353                 nfs_set_mount_transport_protocol(ctx);
1354                 if (ctx->nfs_server.protocol == XPRT_TRANSPORT_RDMA)
1355                         port = NFS_RDMA_PORT;
1356         }
1357
1358         nfs_set_port(sap, &ctx->nfs_server.port, port);
1359
1360         ret = nfs_parse_source(fc, max_namelen, max_pathlen);
1361         if (ret < 0)
1362                 return ret;
1363
1364         /* Load the NFS protocol module if we haven't done so yet */
1365         if (!ctx->nfs_mod) {
1366                 nfs_mod = get_nfs_version(ctx->version);
1367                 if (IS_ERR(nfs_mod)) {
1368                         ret = PTR_ERR(nfs_mod);
1369                         goto out_version_unavailable;
1370                 }
1371                 ctx->nfs_mod = nfs_mod;
1372         }
1373
1374         /* Ensure the filesystem context has the correct fs_type */
1375         if (fc->fs_type != ctx->nfs_mod->nfs_fs) {
1376                 module_put(fc->fs_type->owner);
1377                 __module_get(ctx->nfs_mod->nfs_fs->owner);
1378                 fc->fs_type = ctx->nfs_mod->nfs_fs;
1379         }
1380         return 0;
1381
1382 out_no_device_name:
1383         return nfs_invalf(fc, "NFS: Device name not specified");
1384 out_v4_not_compiled:
1385         nfs_errorf(fc, "NFS: NFSv4 is not compiled into kernel");
1386         return -EPROTONOSUPPORT;
1387 out_no_address:
1388         return nfs_invalf(fc, "NFS: mount program didn't pass remote address");
1389 out_mountproto_mismatch:
1390         return nfs_invalf(fc, "NFS: Mount server address does not match mountproto= option");
1391 out_proto_mismatch:
1392         return nfs_invalf(fc, "NFS: Server address does not match proto= option");
1393 out_minorversion_mismatch:
1394         return nfs_invalf(fc, "NFS: Mount option vers=%u does not support minorversion=%u",
1395                           ctx->version, ctx->minorversion);
1396 out_migration_misuse:
1397         return nfs_invalf(fc, "NFS: 'Migration' not supported for this NFS version");
1398 out_version_unavailable:
1399         nfs_errorf(fc, "NFS: Version unavailable");
1400         return ret;
1401 }
1402
1403 /*
1404  * Create an NFS superblock by the appropriate method.
1405  */
1406 static int nfs_get_tree(struct fs_context *fc)
1407 {
1408         struct nfs_fs_context *ctx = nfs_fc2context(fc);
1409         int err = nfs_fs_context_validate(fc);
1410
1411         if (err)
1412                 return err;
1413         if (!ctx->internal)
1414                 return ctx->nfs_mod->rpc_ops->try_get_tree(fc);
1415         else
1416                 return nfs_get_tree_common(fc);
1417 }
1418
1419 /*
1420  * Handle duplication of a configuration.  The caller copied *src into *sc, but
1421  * it can't deal with resource pointers in the filesystem context, so we have
1422  * to do that.  We need to clear pointers, copy data or get extra refs as
1423  * appropriate.
1424  */
1425 static int nfs_fs_context_dup(struct fs_context *fc, struct fs_context *src_fc)
1426 {
1427         struct nfs_fs_context *src = nfs_fc2context(src_fc), *ctx;
1428
1429         ctx = kmemdup(src, sizeof(struct nfs_fs_context), GFP_KERNEL);
1430         if (!ctx)
1431                 return -ENOMEM;
1432
1433         ctx->mntfh = nfs_alloc_fhandle();
1434         if (!ctx->mntfh) {
1435                 kfree(ctx);
1436                 return -ENOMEM;
1437         }
1438         nfs_copy_fh(ctx->mntfh, src->mntfh);
1439
1440         __module_get(ctx->nfs_mod->owner);
1441         ctx->client_address             = NULL;
1442         ctx->mount_server.hostname      = NULL;
1443         ctx->nfs_server.export_path     = NULL;
1444         ctx->nfs_server.hostname        = NULL;
1445         ctx->fscache_uniq               = NULL;
1446         ctx->clone_data.fattr           = NULL;
1447         fc->fs_private = ctx;
1448         return 0;
1449 }
1450
1451 static void nfs_fs_context_free(struct fs_context *fc)
1452 {
1453         struct nfs_fs_context *ctx = nfs_fc2context(fc);
1454
1455         if (ctx) {
1456                 if (ctx->server)
1457                         nfs_free_server(ctx->server);
1458                 if (ctx->nfs_mod)
1459                         put_nfs_version(ctx->nfs_mod);
1460                 kfree(ctx->client_address);
1461                 kfree(ctx->mount_server.hostname);
1462                 kfree(ctx->nfs_server.export_path);
1463                 kfree(ctx->nfs_server.hostname);
1464                 kfree(ctx->fscache_uniq);
1465                 nfs_free_fhandle(ctx->mntfh);
1466                 nfs_free_fattr(ctx->clone_data.fattr);
1467                 kfree(ctx);
1468         }
1469 }
1470
1471 static const struct fs_context_operations nfs_fs_context_ops = {
1472         .free                   = nfs_fs_context_free,
1473         .dup                    = nfs_fs_context_dup,
1474         .parse_param            = nfs_fs_context_parse_param,
1475         .parse_monolithic       = nfs_fs_context_parse_monolithic,
1476         .get_tree               = nfs_get_tree,
1477         .reconfigure            = nfs_reconfigure,
1478 };
1479
1480 /*
1481  * Prepare superblock configuration.  We use the namespaces attached to the
1482  * context.  This may be the current process's namespaces, or it may be a
1483  * container's namespaces.
1484  */
1485 static int nfs_init_fs_context(struct fs_context *fc)
1486 {
1487         struct nfs_fs_context *ctx;
1488
1489         ctx = kzalloc(sizeof(struct nfs_fs_context), GFP_KERNEL);
1490         if (unlikely(!ctx))
1491                 return -ENOMEM;
1492
1493         ctx->mntfh = nfs_alloc_fhandle();
1494         if (unlikely(!ctx->mntfh)) {
1495                 kfree(ctx);
1496                 return -ENOMEM;
1497         }
1498
1499         ctx->protofamily        = AF_UNSPEC;
1500         ctx->mountfamily        = AF_UNSPEC;
1501         ctx->mount_server.port  = NFS_UNSPEC_PORT;
1502
1503         if (fc->root) {
1504                 /* reconfigure, start with the current config */
1505                 struct nfs_server *nfss = fc->root->d_sb->s_fs_info;
1506                 struct net *net = nfss->nfs_client->cl_net;
1507
1508                 ctx->flags              = nfss->flags;
1509                 ctx->rsize              = nfss->rsize;
1510                 ctx->wsize              = nfss->wsize;
1511                 ctx->retrans            = nfss->client->cl_timeout->to_retries;
1512                 ctx->selected_flavor    = nfss->client->cl_auth->au_flavor;
1513                 ctx->acregmin           = nfss->acregmin / HZ;
1514                 ctx->acregmax           = nfss->acregmax / HZ;
1515                 ctx->acdirmin           = nfss->acdirmin / HZ;
1516                 ctx->acdirmax           = nfss->acdirmax / HZ;
1517                 ctx->timeo              = 10U * nfss->client->cl_timeout->to_initval / HZ;
1518                 ctx->nfs_server.port    = nfss->port;
1519                 ctx->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
1520                 ctx->version            = nfss->nfs_client->rpc_ops->version;
1521                 ctx->minorversion       = nfss->nfs_client->cl_minorversion;
1522
1523                 memcpy(&ctx->nfs_server.address, &nfss->nfs_client->cl_addr,
1524                         ctx->nfs_server.addrlen);
1525
1526                 if (fc->net_ns != net) {
1527                         put_net(fc->net_ns);
1528                         fc->net_ns = get_net(net);
1529                 }
1530
1531                 ctx->nfs_mod = nfss->nfs_client->cl_nfs_mod;
1532                 __module_get(ctx->nfs_mod->owner);
1533         } else {
1534                 /* defaults */
1535                 ctx->timeo              = NFS_UNSPEC_TIMEO;
1536                 ctx->retrans            = NFS_UNSPEC_RETRANS;
1537                 ctx->acregmin           = NFS_DEF_ACREGMIN;
1538                 ctx->acregmax           = NFS_DEF_ACREGMAX;
1539                 ctx->acdirmin           = NFS_DEF_ACDIRMIN;
1540                 ctx->acdirmax           = NFS_DEF_ACDIRMAX;
1541                 ctx->nfs_server.port    = NFS_UNSPEC_PORT;
1542                 ctx->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1543                 ctx->selected_flavor    = RPC_AUTH_MAXFLAVOR;
1544                 ctx->minorversion       = 0;
1545                 ctx->need_mount         = true;
1546
1547                 fc->s_iflags            |= SB_I_STABLE_WRITES;
1548         }
1549         fc->fs_private = ctx;
1550         fc->ops = &nfs_fs_context_ops;
1551         return 0;
1552 }
1553
1554 struct file_system_type nfs_fs_type = {
1555         .owner                  = THIS_MODULE,
1556         .name                   = "nfs",
1557         .init_fs_context        = nfs_init_fs_context,
1558         .parameters             = nfs_fs_parameters,
1559         .kill_sb                = nfs_kill_super,
1560         .fs_flags               = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
1561 };
1562 MODULE_ALIAS_FS("nfs");
1563 EXPORT_SYMBOL_GPL(nfs_fs_type);
1564
1565 #if IS_ENABLED(CONFIG_NFS_V4)
1566 struct file_system_type nfs4_fs_type = {
1567         .owner                  = THIS_MODULE,
1568         .name                   = "nfs4",
1569         .init_fs_context        = nfs_init_fs_context,
1570         .parameters             = nfs_fs_parameters,
1571         .kill_sb                = nfs_kill_super,
1572         .fs_flags               = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
1573 };
1574 MODULE_ALIAS_FS("nfs4");
1575 MODULE_ALIAS("nfs4");
1576 EXPORT_SYMBOL_GPL(nfs4_fs_type);
1577 #endif /* CONFIG_NFS_V4 */