linux/fs/nfs/fs_context.c
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   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
  33enum 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
  88enum {
  89        Opt_local_lock_all,
  90        Opt_local_lock_flock,
  91        Opt_local_lock_none,
  92        Opt_local_lock_posix,
  93};
  94
  95static 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
 103enum {
 104        Opt_lookupcache_all,
 105        Opt_lookupcache_none,
 106        Opt_lookupcache_positive,
 107};
 108
 109static 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
 117enum {
 118        Opt_write_lazy,
 119        Opt_write_eager,
 120        Opt_write_wait,
 121};
 122
 123static 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
 130static 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
 193enum {
 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
 202static 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
 212enum {
 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
 222static 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
 232enum {
 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
 247static 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 */
 269static 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
 287static bool nfs_server_transport_udp_invalid(const struct nfs_fs_context *ctx)
 288{
 289        return true;
 290}
 291#else
 292static 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 */
 303static 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;
 318out_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 */
 326static 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 */
 345static 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 */
 368static 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
 427static 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 */
 469static 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
 839out_invalid_value:
 840        return nfs_invalf(fc, "NFS: Bad mount option value specified");
 841out_invalid_address:
 842        return nfs_invalf(fc, "NFS: Bad IP address specified");
 843out_of_bounds:
 844        return nfs_invalf(fc, "NFS: Value for '%s' out of range", param->key);
 845out_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 */
 858static 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
 912out_bad_devname:
 913        return nfs_invalf(fc, "NFS: device name not in host:path format");
 914out_nomem:
 915        nfs_errorf(fc, "NFS: not enough memory to parse device name");
 916        return -ENOMEM;
 917out_hostname:
 918        nfs_errorf(fc, "NFS: server hostname too long");
 919        return -ENAMETOOLONG;
 920out_path:
 921        nfs_errorf(fc, "NFS: export pathname too long");
 922        return -ENAMETOOLONG;
 923}
 924
 925static 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 */
 946static 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
1086generic:
1087        return generic_parse_monolithic(fc, data);
1088
1089out_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
1096out_no_v3:
1097        return nfs_invalf(fc, "NFS: nfs_mount_data version does not support v3");
1098
1099out_no_sec:
1100        return nfs_invalf(fc, "NFS: nfs_mount_data version supports only AUTH_SYS");
1101
1102out_nomem:
1103        dfprintk(MOUNT, "NFS: not enough memory to handle mount options");
1104        return -ENOMEM;
1105
1106out_no_address:
1107        return nfs_invalf(fc, "NFS: mount program didn't pass remote address");
1108
1109out_invalid_fh:
1110        return nfs_invalf(fc, "NFS: invalid root filehandle");
1111
1112out_invalid_data:
1113        return nfs_invalf(fc, "NFS: invalid binary mount data");
1114}
1115
1116#if IS_ENABLED(CONFIG_NFS_V4)
1117struct compat_nfs_string {
1118        compat_uint_t len;
1119        compat_uptr_t data;
1120};
1121
1122static 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
1129struct 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
1150static 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 */
1179static 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;
1260done:
1261        ctx->skip_reconfig_option_check = true;
1262        return 0;
1263
1264out_inval_auth:
1265        return nfs_invalf(fc, "NFS4: Invalid number of RPC auth flavours %d",
1266                      data->auth_flavourlen);
1267
1268out_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 */
1276static 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 */
1293static 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
1382out_no_device_name:
1383        return nfs_invalf(fc, "NFS: Device name not specified");
1384out_v4_not_compiled:
1385        nfs_errorf(fc, "NFS: NFSv4 is not compiled into kernel");
1386        return -EPROTONOSUPPORT;
1387out_no_address:
1388        return nfs_invalf(fc, "NFS: mount program didn't pass remote address");
1389out_mountproto_mismatch:
1390        return nfs_invalf(fc, "NFS: Mount server address does not match mountproto= option");
1391out_proto_mismatch:
1392        return nfs_invalf(fc, "NFS: Server address does not match proto= option");
1393out_minorversion_mismatch:
1394        return nfs_invalf(fc, "NFS: Mount option vers=%u does not support minorversion=%u",
1395                          ctx->version, ctx->minorversion);
1396out_migration_misuse:
1397        return nfs_invalf(fc, "NFS: 'Migration' not supported for this NFS version");
1398out_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 */
1406static 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 */
1425static 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
1451static 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
1471static 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 */
1485static 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
1554struct 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};
1562MODULE_ALIAS_FS("nfs");
1563EXPORT_SYMBOL_GPL(nfs_fs_type);
1564
1565#if IS_ENABLED(CONFIG_NFS_V4)
1566struct 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};
1574MODULE_ALIAS_FS("nfs4");
1575MODULE_ALIAS("nfs4");
1576EXPORT_SYMBOL_GPL(nfs4_fs_type);
1577#endif /* CONFIG_NFS_V4 */
1578