fs/nfs/fs_context.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * linux/fs/nfs/fs_context.c
   4  *
   5  * Copyright (C) 1992 Rick Sladkey
   6  * Conversion to new mount api Copyright (C) David Howells
   7  *
   8  * NFS mount handling.
   9  *
  10  * Split from fs/nfs/super.c by David Howells <dhowells@redhat.com>
  11  */
  12
  13 #include <linux/compat.h>
  14 #include <linux/module.h>
  15 #include <linux/fs.h>
  16 #include <linux/fs_context.h>
  17 #include <linux/fs_parser.h>
  18 #include <linux/nfs_fs.h>
  19 #include <linux/nfs_mount.h>
  20 #include <linux/nfs4_mount.h>
  21
  22 #include <net/handshake.h>
  23
  24 #include "nfs.h"
  25 #include "internal.h"
  26
  27 #include "nfstrace.h"
  28
  29 #define NFSDBG_FACILITY         NFSDBG_MOUNT
  30
  31 #if IS_ENABLED(CONFIG_NFS_V3)
  32 #define NFS_DEFAULT_VERSION 3
  33 #else
  34 #define NFS_DEFAULT_VERSION 2
  35 #endif
  36
  37 #define NFS_MAX_CONNECTIONS 16
  38
  39 enum nfs_param {
  40         Opt_ac,
  41         Opt_acdirmax,
  42         Opt_acdirmin,
  43         Opt_acl,
  44         Opt_acregmax,
  45         Opt_acregmin,
  46         Opt_actimeo,
  47         Opt_addr,
  48         Opt_bg,
  49         Opt_bsize,
  50         Opt_clientaddr,
  51         Opt_cto,
  52         Opt_fg,
  53         Opt_fscache,
  54         Opt_fscache_flag,
  55         Opt_hard,
  56         Opt_intr,
  57         Opt_local_lock,
  58         Opt_lock,
  59         Opt_lookupcache,
  60         Opt_migration,
  61         Opt_minorversion,
  62         Opt_mountaddr,
  63         Opt_mounthost,
  64         Opt_mountport,
  65         Opt_mountproto,
  66         Opt_mountvers,
  67         Opt_namelen,
  68         Opt_nconnect,
  69         Opt_max_connect,
  70         Opt_port,
  71         Opt_posix,
  72         Opt_proto,
  73         Opt_rdirplus,
  74         Opt_rdma,
  75         Opt_resvport,
  76         Opt_retrans,
  77         Opt_retry,
  78         Opt_rsize,
  79         Opt_sec,
  80         Opt_sharecache,
  81         Opt_sloppy,
  82         Opt_soft,
  83         Opt_softerr,
  84         Opt_softreval,
  85         Opt_source,
  86         Opt_tcp,
  87         Opt_timeo,
  88         Opt_trunkdiscovery,
  89         Opt_udp,
  90         Opt_v,
  91         Opt_vers,
  92         Opt_wsize,
  93         Opt_write,
  94         Opt_xprtsec,
  95 };
  96
  97 enum {
  98         Opt_local_lock_all,
  99         Opt_local_lock_flock,
 100         Opt_local_lock_none,
 101         Opt_local_lock_posix,
 102 };
 103
 104 static const struct constant_table nfs_param_enums_local_lock[] = {
 105         { "all",                Opt_local_lock_all },
 106         { "flock",      Opt_local_lock_flock },
 107         { "posix",      Opt_local_lock_posix },
 108         { "none",               Opt_local_lock_none },
 109         {}
 110 };
 111
 112 enum {
 113         Opt_lookupcache_all,
 114         Opt_lookupcache_none,
 115         Opt_lookupcache_positive,
 116 };
 117
 118 static const struct constant_table nfs_param_enums_lookupcache[] = {
 119         { "all",                Opt_lookupcache_all },
 120         { "none",               Opt_lookupcache_none },
 121         { "pos",                Opt_lookupcache_positive },
 122         { "positive",           Opt_lookupcache_positive },
 123         {}
 124 };
 125
 126 enum {
 127         Opt_write_lazy,
 128         Opt_write_eager,
 129         Opt_write_wait,
 130 };
 131
 132 static const struct constant_table nfs_param_enums_write[] = {
 133         { "lazy",               Opt_write_lazy },
 134         { "eager",              Opt_write_eager },
 135         { "wait",               Opt_write_wait },
 136         {}
 137 };
 138
 139 static const struct fs_parameter_spec nfs_fs_parameters[] = {
 140         fsparam_flag_no("ac",           Opt_ac),
 141         fsparam_u32   ("acdirmax",      Opt_acdirmax),
 142         fsparam_u32   ("acdirmin",      Opt_acdirmin),
 143         fsparam_flag_no("acl",          Opt_acl),
 144         fsparam_u32   ("acregmax",      Opt_acregmax),
 145         fsparam_u32   ("acregmin",      Opt_acregmin),
 146         fsparam_u32   ("actimeo",       Opt_actimeo),
 147         fsparam_string("addr",          Opt_addr),
 148         fsparam_flag  ("bg",            Opt_bg),
 149         fsparam_u32   ("bsize",         Opt_bsize),
 150         fsparam_string("clientaddr",    Opt_clientaddr),
 151         fsparam_flag_no("cto",          Opt_cto),
 152         fsparam_flag  ("fg",            Opt_fg),
 153         fsparam_flag_no("fsc",          Opt_fscache_flag),
 154         fsparam_string("fsc",           Opt_fscache),
 155         fsparam_flag  ("hard",          Opt_hard),
 156         __fsparam(NULL, "intr",         Opt_intr,
 157                   fs_param_neg_with_no|fs_param_deprecated, NULL),
 158         fsparam_enum  ("local_lock",    Opt_local_lock, nfs_param_enums_local_lock),
 159         fsparam_flag_no("lock",         Opt_lock),
 160         fsparam_enum  ("lookupcache",   Opt_lookupcache, nfs_param_enums_lookupcache),
 161         fsparam_flag_no("migration",    Opt_migration),
 162         fsparam_u32   ("minorversion",  Opt_minorversion),
 163         fsparam_string("mountaddr",     Opt_mountaddr),
 164         fsparam_string("mounthost",     Opt_mounthost),
 165         fsparam_u32   ("mountport",     Opt_mountport),
 166         fsparam_string("mountproto",    Opt_mountproto),
 167         fsparam_u32   ("mountvers",     Opt_mountvers),
 168         fsparam_u32   ("namlen",        Opt_namelen),
 169         fsparam_u32   ("nconnect",      Opt_nconnect),
 170         fsparam_u32   ("max_connect",   Opt_max_connect),
 171         fsparam_string("nfsvers",       Opt_vers),
 172         fsparam_u32   ("port",          Opt_port),
 173         fsparam_flag_no("posix",        Opt_posix),
 174         fsparam_string("proto",         Opt_proto),
 175         fsparam_flag_no("rdirplus",     Opt_rdirplus),
 176         fsparam_flag  ("rdma",          Opt_rdma),
 177         fsparam_flag_no("resvport",     Opt_resvport),
 178         fsparam_u32   ("retrans",       Opt_retrans),
 179         fsparam_string("retry",         Opt_retry),
 180         fsparam_u32   ("rsize",         Opt_rsize),
 181         fsparam_string("sec",           Opt_sec),
 182         fsparam_flag_no("sharecache",   Opt_sharecache),
 183         fsparam_flag  ("sloppy",        Opt_sloppy),
 184         fsparam_flag  ("soft",          Opt_soft),
 185         fsparam_flag  ("softerr",       Opt_softerr),
 186         fsparam_flag  ("softreval",     Opt_softreval),
 187         fsparam_string("source",        Opt_source),
 188         fsparam_flag  ("tcp",           Opt_tcp),
 189         fsparam_u32   ("timeo",         Opt_timeo),
 190         fsparam_flag_no("trunkdiscovery", Opt_trunkdiscovery),
 191         fsparam_flag  ("udp",           Opt_udp),
 192         fsparam_flag  ("v2",            Opt_v),
 193         fsparam_flag  ("v3",            Opt_v),
 194         fsparam_flag  ("v4",            Opt_v),
 195         fsparam_flag  ("v4.0",          Opt_v),
 196         fsparam_flag  ("v4.1",          Opt_v),
 197         fsparam_flag  ("v4.2",          Opt_v),
 198         fsparam_string("vers",          Opt_vers),
 199         fsparam_enum  ("write",         Opt_write, nfs_param_enums_write),
 200         fsparam_u32   ("wsize",         Opt_wsize),
 201         fsparam_string("xprtsec",       Opt_xprtsec),
 202         {}
 203 };
 204
 205 enum {
 206         Opt_vers_2,
 207         Opt_vers_3,
 208         Opt_vers_4,
 209         Opt_vers_4_0,
 210         Opt_vers_4_1,
 211         Opt_vers_4_2,
 212 };
 213
 214 static const struct constant_table nfs_vers_tokens[] = {
 215         { "2",          Opt_vers_2 },
 216         { "3",          Opt_vers_3 },
 217         { "4",          Opt_vers_4 },
 218         { "4.0",        Opt_vers_4_0 },
 219         { "4.1",        Opt_vers_4_1 },
 220         { "4.2",        Opt_vers_4_2 },
 221         {}
 222 };
 223
 224 enum {
 225         Opt_xprt_rdma,
 226         Opt_xprt_rdma6,
 227         Opt_xprt_tcp,
 228         Opt_xprt_tcp6,
 229         Opt_xprt_udp,
 230         Opt_xprt_udp6,
 231         nr__Opt_xprt
 232 };
 233
 234 static const struct constant_table nfs_xprt_protocol_tokens[] = {
 235         { "rdma",       Opt_xprt_rdma },
 236         { "rdma6",      Opt_xprt_rdma6 },
 237         { "tcp",        Opt_xprt_tcp },
 238         { "tcp6",       Opt_xprt_tcp6 },
 239         { "udp",        Opt_xprt_udp },
 240         { "udp6",       Opt_xprt_udp6 },
 241         {}
 242 };
 243
 244 enum {
 245         Opt_sec_krb5,
 246         Opt_sec_krb5i,
 247         Opt_sec_krb5p,
 248         Opt_sec_lkey,
 249         Opt_sec_lkeyi,
 250         Opt_sec_lkeyp,
 251         Opt_sec_none,
 252         Opt_sec_spkm,
 253         Opt_sec_spkmi,
 254         Opt_sec_spkmp,
 255         Opt_sec_sys,
 256         nr__Opt_sec
 257 };
 258
 259 static const struct constant_table nfs_secflavor_tokens[] = {
 260         { "krb5",       Opt_sec_krb5 },
 261         { "krb5i",      Opt_sec_krb5i },
 262         { "krb5p",      Opt_sec_krb5p },
 263         { "lkey",       Opt_sec_lkey },
 264         { "lkeyi",      Opt_sec_lkeyi },
 265         { "lkeyp",      Opt_sec_lkeyp },
 266         { "none",       Opt_sec_none },
 267         { "null",       Opt_sec_none },
 268         { "spkm3",      Opt_sec_spkm },
 269         { "spkm3i",     Opt_sec_spkmi },
 270         { "spkm3p",     Opt_sec_spkmp },
 271         { "sys",        Opt_sec_sys },
 272         {}
 273 };
 274
 275 enum {
 276         Opt_xprtsec_none,
 277         Opt_xprtsec_tls,
 278         Opt_xprtsec_mtls,
 279         nr__Opt_xprtsec
 280 };
 281
 282 static const struct constant_table nfs_xprtsec_policies[] = {
 283         { "none",       Opt_xprtsec_none },
 284         { "tls",        Opt_xprtsec_tls },
 285         { "mtls",       Opt_xprtsec_mtls },
 286         {}
 287 };
 288
 289 /*
 290  * Sanity-check a server address provided by the mount command.
 291  *
 292  * Address family must be initialized, and address must not be
 293  * the ANY address for that family.
 294  */
 295 static int nfs_verify_server_address(struct sockaddr_storage *addr)
 296 {
 297         switch (addr->ss_family) {
 298         case AF_INET: {
 299                 struct sockaddr_in *sa = (struct sockaddr_in *)addr;
 300                 return sa->sin_addr.s_addr != htonl(INADDR_ANY);
 301         }
 302         case AF_INET6: {
 303                 struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
 304                 return !ipv6_addr_any(sa);
 305         }
 306         }
 307
 308         return 0;
 309 }
 310
 311 #ifdef CONFIG_NFS_DISABLE_UDP_SUPPORT
 312 static bool nfs_server_transport_udp_invalid(const struct nfs_fs_context *ctx)
 313 {
 314         return true;
 315 }
 316 #else
 317 static bool nfs_server_transport_udp_invalid(const struct nfs_fs_context *ctx)
 318 {
 319         if (ctx->version == 4)
 320                 return true;
 321         return false;
 322 }
 323 #endif
 324
 325 /*
 326  * Sanity check the NFS transport protocol.
 327  */
 328 static int nfs_validate_transport_protocol(struct fs_context *fc,
 329                                            struct nfs_fs_context *ctx)
 330 {
 331         switch (ctx->nfs_server.protocol) {
 332         case XPRT_TRANSPORT_UDP:
 333                 if (nfs_server_transport_udp_invalid(ctx))
 334                         goto out_invalid_transport_udp;
 335                 break;
 336         case XPRT_TRANSPORT_TCP:
 337         case XPRT_TRANSPORT_RDMA:
 338                 break;
 339         default:
 340                 ctx->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 341         }
 342
 343         if (ctx->xprtsec.policy != RPC_XPRTSEC_NONE)
 344                 switch (ctx->nfs_server.protocol) {
 345                 case XPRT_TRANSPORT_TCP:
 346                         ctx->nfs_server.protocol = XPRT_TRANSPORT_TCP_TLS;
 347                         break;
 348                 default:
 349                         goto out_invalid_xprtsec_policy;
 350         }
 351
 352         return 0;
 353 out_invalid_transport_udp:
 354         return nfs_invalf(fc, "NFS: Unsupported transport protocol udp");
 355 out_invalid_xprtsec_policy:
 356         return nfs_invalf(fc, "NFS: Transport does not support xprtsec");
 357 }
 358
 359 /*
 360  * For text based NFSv2/v3 mounts, the mount protocol transport default
 361  * settings should depend upon the specified NFS transport.
 362  */
 363 static void nfs_set_mount_transport_protocol(struct nfs_fs_context *ctx)
 364 {
 365         if (ctx->mount_server.protocol == XPRT_TRANSPORT_UDP ||
 366             ctx->mount_server.protocol == XPRT_TRANSPORT_TCP)
 367                         return;
 368         switch (ctx->nfs_server.protocol) {
 369         case XPRT_TRANSPORT_UDP:
 370                 ctx->mount_server.protocol = XPRT_TRANSPORT_UDP;
 371                 break;
 372         case XPRT_TRANSPORT_TCP:
 373         case XPRT_TRANSPORT_RDMA:
 374                 ctx->mount_server.protocol = XPRT_TRANSPORT_TCP;
 375         }
 376 }
 377
 378 /*
 379  * Add 'flavor' to 'auth_info' if not already present.
 380  * Returns true if 'flavor' ends up in the list, false otherwise
 381  */
 382 static int nfs_auth_info_add(struct fs_context *fc,
 383                              struct nfs_auth_info *auth_info,
 384                              rpc_authflavor_t flavor)
 385 {
 386         unsigned int i;
 387         unsigned int max_flavor_len = ARRAY_SIZE(auth_info->flavors);
 388
 389         /* make sure this flavor isn't already in the list */
 390         for (i = 0; i < auth_info->flavor_len; i++) {
 391                 if (flavor == auth_info->flavors[i])
 392                         return 0;
 393         }
 394
 395         if (auth_info->flavor_len + 1 >= max_flavor_len)
 396                 return nfs_invalf(fc, "NFS: too many sec= flavors");
 397
 398         auth_info->flavors[auth_info->flavor_len++] = flavor;
 399         return 0;
 400 }
 401
 402 /*
 403  * Parse the value of the 'sec=' option.
 404  */
 405 static int nfs_parse_security_flavors(struct fs_context *fc,
 406                                       struct fs_parameter *param)
 407 {
 408         struct nfs_fs_context *ctx = nfs_fc2context(fc);
 409         rpc_authflavor_t pseudoflavor;
 410         char *string = param->string, *p;
 411         int ret;
 412
 413         trace_nfs_mount_assign(param->key, string);
 414
 415         while ((p = strsep(&string, ":")) != NULL) {
 416                 if (!*p)
 417                         continue;
 418                 switch (lookup_constant(nfs_secflavor_tokens, p, -1)) {
 419                 case Opt_sec_none:
 420                         pseudoflavor = RPC_AUTH_NULL;
 421                         break;
 422                 case Opt_sec_sys:
 423                         pseudoflavor = RPC_AUTH_UNIX;
 424                         break;
 425                 case Opt_sec_krb5:
 426                         pseudoflavor = RPC_AUTH_GSS_KRB5;
 427                         break;
 428                 case Opt_sec_krb5i:
 429                         pseudoflavor = RPC_AUTH_GSS_KRB5I;
 430                         break;
 431                 case Opt_sec_krb5p:
 432                         pseudoflavor = RPC_AUTH_GSS_KRB5P;
 433                         break;
 434                 case Opt_sec_lkey:
 435                         pseudoflavor = RPC_AUTH_GSS_LKEY;
 436                         break;
 437                 case Opt_sec_lkeyi:
 438                         pseudoflavor = RPC_AUTH_GSS_LKEYI;
 439                         break;
 440                 case Opt_sec_lkeyp:
 441                         pseudoflavor = RPC_AUTH_GSS_LKEYP;
 442                         break;
 443                 case Opt_sec_spkm:
 444                         pseudoflavor = RPC_AUTH_GSS_SPKM;
 445                         break;
 446                 case Opt_sec_spkmi:
 447                         pseudoflavor = RPC_AUTH_GSS_SPKMI;
 448                         break;
 449                 case Opt_sec_spkmp:
 450                         pseudoflavor = RPC_AUTH_GSS_SPKMP;
 451                         break;
 452                 default:
 453                         return nfs_invalf(fc, "NFS: sec=%s option not recognized", p);
 454                 }
 455
 456                 ret = nfs_auth_info_add(fc, &ctx->auth_info, pseudoflavor);
 457                 if (ret < 0)
 458                         return ret;
 459         }
 460
 461         return 0;
 462 }
 463
 464 static int nfs_parse_xprtsec_policy(struct fs_context *fc,
 465                                     struct fs_parameter *param)
 466 {
 467         struct nfs_fs_context *ctx = nfs_fc2context(fc);
 468
 469         trace_nfs_mount_assign(param->key, param->string);
 470
 471         switch (lookup_constant(nfs_xprtsec_policies, param->string, -1)) {
 472         case Opt_xprtsec_none:
 473                 ctx->xprtsec.policy = RPC_XPRTSEC_NONE;
 474                 break;
 475         case Opt_xprtsec_tls:
 476                 ctx->xprtsec.policy = RPC_XPRTSEC_TLS_ANON;
 477                 break;
 478         case Opt_xprtsec_mtls:
 479                 ctx->xprtsec.policy = RPC_XPRTSEC_TLS_X509;
 480                 break;
 481         default:
 482                 return nfs_invalf(fc, "NFS: Unrecognized transport security policy");
 483         }
 484         return 0;
 485 }
 486
 487 static int nfs_parse_version_string(struct fs_context *fc,
 488                                     const char *string)
 489 {
 490         struct nfs_fs_context *ctx = nfs_fc2context(fc);
 491
 492         ctx->flags &= ~NFS_MOUNT_VER3;
 493         switch (lookup_constant(nfs_vers_tokens, string, -1)) {
 494         case Opt_vers_2:
 495                 ctx->version = 2;
 496                 break;
 497         case Opt_vers_3:
 498                 ctx->flags |= NFS_MOUNT_VER3;
 499                 ctx->version = 3;
 500                 break;
 501         case Opt_vers_4:
 502                 /* Backward compatibility option. In future,
 503                  * the mount program should always supply
 504                  * a NFSv4 minor version number.
 505                  */
 506                 ctx->version = 4;
 507                 break;
 508         case Opt_vers_4_0:
 509                 ctx->version = 4;
 510                 ctx->minorversion = 0;
 511                 break;
 512         case Opt_vers_4_1:
 513                 ctx->version = 4;
 514                 ctx->minorversion = 1;
 515                 break;
 516         case Opt_vers_4_2:
 517                 ctx->version = 4;
 518                 ctx->minorversion = 2;
 519                 break;
 520         default:
 521                 return nfs_invalf(fc, "NFS: Unsupported NFS version");
 522         }
 523         return 0;
 524 }
 525
 526 /*
 527  * Parse a single mount parameter.
 528  */
 529 static int nfs_fs_context_parse_param(struct fs_context *fc,
 530                                       struct fs_parameter *param)
 531 {
 532         struct fs_parse_result result;
 533         struct nfs_fs_context *ctx = nfs_fc2context(fc);
 534         unsigned short protofamily, mountfamily;
 535         unsigned int len;
 536         int ret, opt;
 537
 538         trace_nfs_mount_option(param);
 539
 540         opt = fs_parse(fc, nfs_fs_parameters, param, &result);
 541         if (opt < 0)
 542                 return (opt == -ENOPARAM && ctx->sloppy) ? 1 : opt;
 543
 544         if (fc->security)
 545                 ctx->has_sec_mnt_opts = 1;
 546
 547         switch (opt) {
 548         case Opt_source:
 549                 if (fc->source)
 550                         return nfs_invalf(fc, "NFS: Multiple sources not supported");
 551                 fc->source = param->string;
 552                 param->string = NULL;
 553                 break;
 554
 555                 /*
 556                  * boolean options:  foo/nofoo
 557                  */
 558         case Opt_soft:
 559                 ctx->flags |= NFS_MOUNT_SOFT;
 560                 ctx->flags &= ~NFS_MOUNT_SOFTERR;
 561                 break;
 562         case Opt_softerr:
 563                 ctx->flags |= NFS_MOUNT_SOFTERR | NFS_MOUNT_SOFTREVAL;
 564                 ctx->flags &= ~NFS_MOUNT_SOFT;
 565                 break;
 566         case Opt_hard:
 567                 ctx->flags &= ~(NFS_MOUNT_SOFT |
 568                                 NFS_MOUNT_SOFTERR |
 569                                 NFS_MOUNT_SOFTREVAL);
 570                 break;
 571         case Opt_softreval:
 572                 if (result.negated)
 573                         ctx->flags &= ~NFS_MOUNT_SOFTREVAL;
 574                 else
 575                         ctx->flags |= NFS_MOUNT_SOFTREVAL;
 576                 break;
 577         case Opt_posix:
 578                 if (result.negated)
 579                         ctx->flags &= ~NFS_MOUNT_POSIX;
 580                 else
 581                         ctx->flags |= NFS_MOUNT_POSIX;
 582                 break;
 583         case Opt_cto:
 584                 if (result.negated)
 585                         ctx->flags |= NFS_MOUNT_NOCTO;
 586                 else
 587                         ctx->flags &= ~NFS_MOUNT_NOCTO;
 588                 break;
 589         case Opt_trunkdiscovery:
 590                 if (result.negated)
 591                         ctx->flags &= ~NFS_MOUNT_TRUNK_DISCOVERY;
 592                 else
 593                         ctx->flags |= NFS_MOUNT_TRUNK_DISCOVERY;
 594                 break;
 595         case Opt_ac:
 596                 if (result.negated)
 597                         ctx->flags |= NFS_MOUNT_NOAC;
 598                 else
 599                         ctx->flags &= ~NFS_MOUNT_NOAC;
 600                 break;
 601         case Opt_lock:
 602                 if (result.negated) {
 603                         ctx->flags |= NFS_MOUNT_NONLM;
 604                         ctx->flags |= (NFS_MOUNT_LOCAL_FLOCK | NFS_MOUNT_LOCAL_FCNTL);
 605                 } else {
 606                         ctx->flags &= ~NFS_MOUNT_NONLM;
 607                         ctx->flags &= ~(NFS_MOUNT_LOCAL_FLOCK | NFS_MOUNT_LOCAL_FCNTL);
 608                 }
 609                 break;
 610         case Opt_udp:
 611                 ctx->flags &= ~NFS_MOUNT_TCP;
 612                 ctx->nfs_server.protocol = XPRT_TRANSPORT_UDP;
 613                 break;
 614         case Opt_tcp:
 615         case Opt_rdma:
 616                 ctx->flags |= NFS_MOUNT_TCP; /* for side protocols */
 617                 ret = xprt_find_transport_ident(param->key);
 618                 if (ret < 0)
 619                         goto out_bad_transport;
 620                 ctx->nfs_server.protocol = ret;
 621                 break;
 622         case Opt_acl:
 623                 if (result.negated)
 624                         ctx->flags |= NFS_MOUNT_NOACL;
 625                 else
 626                         ctx->flags &= ~NFS_MOUNT_NOACL;
 627                 break;
 628         case Opt_rdirplus:
 629                 if (result.negated)
 630                         ctx->flags |= NFS_MOUNT_NORDIRPLUS;
 631                 else
 632                         ctx->flags &= ~NFS_MOUNT_NORDIRPLUS;
 633                 break;
 634         case Opt_sharecache:
 635                 if (result.negated)
 636                         ctx->flags |= NFS_MOUNT_UNSHARED;
 637                 else
 638                         ctx->flags &= ~NFS_MOUNT_UNSHARED;
 639                 break;
 640         case Opt_resvport:
 641                 if (result.negated)
 642                         ctx->flags |= NFS_MOUNT_NORESVPORT;
 643                 else
 644                         ctx->flags &= ~NFS_MOUNT_NORESVPORT;
 645                 break;
 646         case Opt_fscache_flag:
 647                 if (result.negated)
 648                         ctx->options &= ~NFS_OPTION_FSCACHE;
 649                 else
 650                         ctx->options |= NFS_OPTION_FSCACHE;
 651                 kfree(ctx->fscache_uniq);
 652                 ctx->fscache_uniq = NULL;
 653                 break;
 654         case Opt_fscache:
 655                 ctx->options |= NFS_OPTION_FSCACHE;
 656                 kfree(ctx->fscache_uniq);
 657                 ctx->fscache_uniq = param->string;
 658                 param->string = NULL;
 659                 break;
 660         case Opt_migration:
 661                 if (result.negated)
 662                         ctx->options &= ~NFS_OPTION_MIGRATION;
 663                 else
 664                         ctx->options |= NFS_OPTION_MIGRATION;
 665                 break;
 666
 667                 /*
 668                  * options that take numeric values
 669                  */
 670         case Opt_port:
 671                 if (result.uint_32 > USHRT_MAX)
 672                         goto out_of_bounds;
 673                 ctx->nfs_server.port = result.uint_32;
 674                 break;
 675         case Opt_rsize:
 676                 ctx->rsize = result.uint_32;
 677                 break;
 678         case Opt_wsize:
 679                 ctx->wsize = result.uint_32;
 680                 break;
 681         case Opt_bsize:
 682                 ctx->bsize = result.uint_32;
 683                 break;
 684         case Opt_timeo:
 685                 if (result.uint_32 < 1 || result.uint_32 > INT_MAX)
 686                         goto out_of_bounds;
 687                 ctx->timeo = result.uint_32;
 688                 break;
 689         case Opt_retrans:
 690                 if (result.uint_32 > INT_MAX)
 691                         goto out_of_bounds;
 692                 ctx->retrans = result.uint_32;
 693                 break;
 694         case Opt_acregmin:
 695                 ctx->acregmin = result.uint_32;
 696                 break;
 697         case Opt_acregmax:
 698                 ctx->acregmax = result.uint_32;
 699                 break;
 700         case Opt_acdirmin:
 701                 ctx->acdirmin = result.uint_32;
 702                 break;
 703         case Opt_acdirmax:
 704                 ctx->acdirmax = result.uint_32;
 705                 break;
 706         case Opt_actimeo:
 707                 ctx->acregmin = result.uint_32;
 708                 ctx->acregmax = result.uint_32;
 709                 ctx->acdirmin = result.uint_32;
 710                 ctx->acdirmax = result.uint_32;
 711                 break;
 712         case Opt_namelen:
 713                 ctx->namlen = result.uint_32;
 714                 break;
 715         case Opt_mountport:
 716                 if (result.uint_32 > USHRT_MAX)
 717                         goto out_of_bounds;
 718                 ctx->mount_server.port = result.uint_32;
 719                 break;
 720         case Opt_mountvers:
 721                 if (result.uint_32 < NFS_MNT_VERSION ||
 722                     result.uint_32 > NFS_MNT3_VERSION)
 723                         goto out_of_bounds;
 724                 ctx->mount_server.version = result.uint_32;
 725                 break;
 726         case Opt_minorversion:
 727                 if (result.uint_32 > NFS4_MAX_MINOR_VERSION)
 728                         goto out_of_bounds;
 729                 ctx->minorversion = result.uint_32;
 730                 break;
 731
 732                 /*
 733                  * options that take text values
 734                  */
 735         case Opt_v:
 736                 ret = nfs_parse_version_string(fc, param->key + 1);
 737                 if (ret < 0)
 738                         return ret;
 739                 break;
 740         case Opt_vers:
 741                 if (!param->string)
 742                         goto out_invalid_value;
 743                 trace_nfs_mount_assign(param->key, param->string);
 744                 ret = nfs_parse_version_string(fc, param->string);
 745                 if (ret < 0)
 746                         return ret;
 747                 break;
 748         case Opt_sec:
 749                 ret = nfs_parse_security_flavors(fc, param);
 750                 if (ret < 0)
 751                         return ret;
 752                 break;
 753         case Opt_xprtsec:
 754                 ret = nfs_parse_xprtsec_policy(fc, param);
 755                 if (ret < 0)
 756                         return ret;
 757                 break;
 758
 759         case Opt_proto:
 760                 if (!param->string)
 761                         goto out_invalid_value;
 762                 trace_nfs_mount_assign(param->key, param->string);
 763                 protofamily = AF_INET;
 764                 switch (lookup_constant(nfs_xprt_protocol_tokens, param->string, -1)) {
 765                 case Opt_xprt_udp6:
 766                         protofamily = AF_INET6;
 767                         fallthrough;
 768                 case Opt_xprt_udp:
 769                         ctx->flags &= ~NFS_MOUNT_TCP;
 770                         ctx->nfs_server.protocol = XPRT_TRANSPORT_UDP;
 771                         break;
 772                 case Opt_xprt_tcp6:
 773                         protofamily = AF_INET6;
 774                         fallthrough;
 775                 case Opt_xprt_tcp:
 776                         ctx->flags |= NFS_MOUNT_TCP;
 777                         ctx->nfs_server.protocol = XPRT_TRANSPORT_TCP;
 778                         break;
 779                 case Opt_xprt_rdma6:
 780                         protofamily = AF_INET6;
 781                         fallthrough;
 782                 case Opt_xprt_rdma:
 783                         /* vector side protocols to TCP */
 784                         ctx->flags |= NFS_MOUNT_TCP;
 785                         ret = xprt_find_transport_ident(param->string);
 786                         if (ret < 0)
 787                                 goto out_bad_transport;
 788                         ctx->nfs_server.protocol = ret;
 789                         break;
 790                 default:
 791                         goto out_bad_transport;
 792                 }
 793
 794                 ctx->protofamily = protofamily;
 795                 break;
 796
 797         case Opt_mountproto:
 798                 if (!param->string)
 799                         goto out_invalid_value;
 800                 trace_nfs_mount_assign(param->key, param->string);
 801                 mountfamily = AF_INET;
 802                 switch (lookup_constant(nfs_xprt_protocol_tokens, param->string, -1)) {
 803                 case Opt_xprt_udp6:
 804                         mountfamily = AF_INET6;
 805                         fallthrough;
 806                 case Opt_xprt_udp:
 807                         ctx->mount_server.protocol = XPRT_TRANSPORT_UDP;
 808                         break;
 809                 case Opt_xprt_tcp6:
 810                         mountfamily = AF_INET6;
 811                         fallthrough;
 812                 case Opt_xprt_tcp:
 813                         ctx->mount_server.protocol = XPRT_TRANSPORT_TCP;
 814                         break;
 815                 case Opt_xprt_rdma: /* not used for side protocols */
 816                 default:
 817                         goto out_bad_transport;
 818                 }
 819                 ctx->mountfamily = mountfamily;
 820                 break;
 821
 822         case Opt_addr:
 823                 trace_nfs_mount_assign(param->key, param->string);
 824                 len = rpc_pton(fc->net_ns, param->string, param->size,
 825                                &ctx->nfs_server.address,
 826                                sizeof(ctx->nfs_server._address));
 827                 if (len == 0)
 828                         goto out_invalid_address;
 829                 ctx->nfs_server.addrlen = len;
 830                 break;
 831         case Opt_clientaddr:
 832                 trace_nfs_mount_assign(param->key, param->string);
 833                 kfree(ctx->client_address);
 834                 ctx->client_address = param->string;
 835                 param->string = NULL;
 836                 break;
 837         case Opt_mounthost:
 838                 trace_nfs_mount_assign(param->key, param->string);
 839                 kfree(ctx->mount_server.hostname);
 840                 ctx->mount_server.hostname = param->string;
 841                 param->string = NULL;
 842                 break;
 843         case Opt_mountaddr:
 844                 trace_nfs_mount_assign(param->key, param->string);
 845                 len = rpc_pton(fc->net_ns, param->string, param->size,
 846                                &ctx->mount_server.address,
 847                                sizeof(ctx->mount_server._address));
 848                 if (len == 0)
 849                         goto out_invalid_address;
 850                 ctx->mount_server.addrlen = len;
 851                 break;
 852         case Opt_nconnect:
 853                 trace_nfs_mount_assign(param->key, param->string);
 854                 if (result.uint_32 < 1 || result.uint_32 > NFS_MAX_CONNECTIONS)
 855                         goto out_of_bounds;
 856                 ctx->nfs_server.nconnect = result.uint_32;
 857                 break;
 858         case Opt_max_connect:
 859                 trace_nfs_mount_assign(param->key, param->string);
 860                 if (result.uint_32 < 1 || result.uint_32 > NFS_MAX_TRANSPORTS)
 861                         goto out_of_bounds;
 862                 ctx->nfs_server.max_connect = result.uint_32;
 863                 break;
 864         case Opt_lookupcache:
 865                 trace_nfs_mount_assign(param->key, param->string);
 866                 switch (result.uint_32) {
 867                 case Opt_lookupcache_all:
 868                         ctx->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
 869                         break;
 870                 case Opt_lookupcache_positive:
 871                         ctx->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
 872                         ctx->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
 873                         break;
 874                 case Opt_lookupcache_none:
 875                         ctx->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
 876                         break;
 877                 default:
 878                         goto out_invalid_value;
 879                 }
 880                 break;
 881         case Opt_local_lock:
 882                 trace_nfs_mount_assign(param->key, param->string);
 883                 switch (result.uint_32) {
 884                 case Opt_local_lock_all:
 885                         ctx->flags |= (NFS_MOUNT_LOCAL_FLOCK |
 886                                        NFS_MOUNT_LOCAL_FCNTL);
 887                         break;
 888                 case Opt_local_lock_flock:
 889                         ctx->flags |= NFS_MOUNT_LOCAL_FLOCK;
 890                         break;
 891                 case Opt_local_lock_posix:
 892                         ctx->flags |= NFS_MOUNT_LOCAL_FCNTL;
 893                         break;
 894                 case Opt_local_lock_none:
 895                         ctx->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
 896                                         NFS_MOUNT_LOCAL_FCNTL);
 897                         break;
 898                 default:
 899                         goto out_invalid_value;
 900                 }
 901                 break;
 902         case Opt_write:
 903                 trace_nfs_mount_assign(param->key, param->string);
 904                 switch (result.uint_32) {
 905                 case Opt_write_lazy:
 906                         ctx->flags &=
 907                                 ~(NFS_MOUNT_WRITE_EAGER | NFS_MOUNT_WRITE_WAIT);
 908                         break;
 909                 case Opt_write_eager:
 910                         ctx->flags |= NFS_MOUNT_WRITE_EAGER;
 911                         ctx->flags &= ~NFS_MOUNT_WRITE_WAIT;
 912                         break;
 913                 case Opt_write_wait:
 914                         ctx->flags |=
 915                                 NFS_MOUNT_WRITE_EAGER | NFS_MOUNT_WRITE_WAIT;
 916                         break;
 917                 default:
 918                         goto out_invalid_value;
 919                 }
 920                 break;
 921
 922                 /*
 923                  * Special options
 924                  */
 925         case Opt_sloppy:
 926                 ctx->sloppy = true;
 927                 break;
 928         }
 929
 930         return 0;
 931
 932 out_invalid_value:
 933         return nfs_invalf(fc, "NFS: Bad mount option value specified");
 934 out_invalid_address:
 935         return nfs_invalf(fc, "NFS: Bad IP address specified");
 936 out_of_bounds:
 937         return nfs_invalf(fc, "NFS: Value for '%s' out of range", param->key);
 938 out_bad_transport:
 939         return nfs_invalf(fc, "NFS: Unrecognized transport protocol");
 940 }
 941
 942 /*
 943  * Split fc->source into "hostname:export_path".
 944  *
 945  * The leftmost colon demarks the split between the server's hostname
 946  * and the export path.  If the hostname starts with a left square
 947  * bracket, then it may contain colons.
 948  *
 949  * Note: caller frees hostname and export path, even on error.
 950  */
 951 static int nfs_parse_source(struct fs_context *fc,
 952                             size_t maxnamlen, size_t maxpathlen)
 953 {
 954         struct nfs_fs_context *ctx = nfs_fc2context(fc);
 955         const char *dev_name = fc->source;
 956         size_t len;
 957         const char *end;
 958
 959         if (unlikely(!dev_name || !*dev_name))
 960                 return -EINVAL;
 961
 962         /* Is the host name protected with square brakcets? */
 963         if (*dev_name == '[') {
 964                 end = strchr(++dev_name, ']');
 965                 if (end == NULL || end[1] != ':')
 966                         goto out_bad_devname;
 967
 968                 len = end - dev_name;
 969                 end++;
 970         } else {
 971                 const char *comma;
 972
 973                 end = strchr(dev_name, ':');
 974                 if (end == NULL)
 975                         goto out_bad_devname;
 976                 len = end - dev_name;
 977
 978                 /* kill possible hostname list: not supported */
 979                 comma = memchr(dev_name, ',', len);
 980                 if (comma)
 981                         len = comma - dev_name;
 982         }
 983
 984         if (len > maxnamlen)
 985                 goto out_hostname;
 986
 987         kfree(ctx->nfs_server.hostname);
 988
 989         /* N.B. caller will free nfs_server.hostname in all cases */
 990         ctx->nfs_server.hostname = kmemdup_nul(dev_name, len, GFP_KERNEL);
 991         if (!ctx->nfs_server.hostname)
 992                 goto out_nomem;
 993         len = strlen(++end);
 994         if (len > maxpathlen)
 995                 goto out_path;
 996         ctx->nfs_server.export_path = kmemdup_nul(end, len, GFP_KERNEL);
 997         if (!ctx->nfs_server.export_path)
 998                 goto out_nomem;
 999
1000         trace_nfs_mount_path(ctx->nfs_server.export_path);
1001         return 0;
1002
1003 out_bad_devname:
1004         return nfs_invalf(fc, "NFS: device name not in host:path format");
1005 out_nomem:
1006         nfs_errorf(fc, "NFS: not enough memory to parse device name");
1007         return -ENOMEM;
1008 out_hostname:
1009         nfs_errorf(fc, "NFS: server hostname too long");
1010         return -ENAMETOOLONG;
1011 out_path:
1012         nfs_errorf(fc, "NFS: export pathname too long");
1013         return -ENAMETOOLONG;
1014 }
1015
1016 static inline bool is_remount_fc(struct fs_context *fc)
1017 {
1018         return fc->root != NULL;
1019 }
1020
1021 /*
1022  * Parse monolithic NFS2/NFS3 mount data
1023  * - fills in the mount root filehandle
1024  *
1025  * For option strings, user space handles the following behaviors:
1026  *
1027  * + DNS: mapping server host name to IP address ("addr=" option)
1028  *
1029  * + failure mode: how to behave if a mount request can't be handled
1030  *   immediately ("fg/bg" option)
1031  *
1032  * + retry: how often to retry a mount request ("retry=" option)
1033  *
1034  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1035  *   mountproto=tcp after mountproto=udp, and so on
1036  */
1037 static int nfs23_parse_monolithic(struct fs_context *fc,
1038                                   struct nfs_mount_data *data)
1039 {
1040         struct nfs_fs_context *ctx = nfs_fc2context(fc);
1041         struct nfs_fh *mntfh = ctx->mntfh;
1042         struct sockaddr_storage *sap = &ctx->nfs_server._address;
1043         int extra_flags = NFS_MOUNT_LEGACY_INTERFACE;
1044         int ret;
1045
1046         if (data == NULL)
1047                 goto out_no_data;
1048
1049         ctx->version = NFS_DEFAULT_VERSION;
1050         switch (data->version) {
1051         case 1:
1052                 data->namlen = 0;
1053                 fallthrough;
1054         case 2:
1055                 data->bsize = 0;
1056                 fallthrough;
1057         case 3:
1058                 if (data->flags & NFS_MOUNT_VER3)
1059                         goto out_no_v3;
1060                 data->root.size = NFS2_FHSIZE;
1061                 memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1062                 /* Turn off security negotiation */
1063                 extra_flags |= NFS_MOUNT_SECFLAVOUR;
1064                 fallthrough;
1065         case 4:
1066                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1067                         goto out_no_sec;
1068                 fallthrough;
1069         case 5:
1070                 memset(data->context, 0, sizeof(data->context));
1071                 fallthrough;
1072         case 6:
1073                 if (data->flags & NFS_MOUNT_VER3) {
1074                         if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1075                                 goto out_invalid_fh;
1076                         mntfh->size = data->root.size;
1077                         ctx->version = 3;
1078                 } else {
1079                         mntfh->size = NFS2_FHSIZE;
1080                         ctx->version = 2;
1081                 }
1082
1083
1084                 memcpy(mntfh->data, data->root.data, mntfh->size);
1085                 if (mntfh->size < sizeof(mntfh->data))
1086                         memset(mntfh->data + mntfh->size, 0,
1087                                sizeof(mntfh->data) - mntfh->size);
1088
1089                 /*
1090                  * for proto == XPRT_TRANSPORT_UDP, which is what uses
1091                  * to_exponential, implying shift: limit the shift value
1092                  * to BITS_PER_LONG (majortimeo is unsigned long)
1093                  */
1094                 if (!(data->flags & NFS_MOUNT_TCP)) /* this will be UDP */
1095                         if (data->retrans >= 64) /* shift value is too large */
1096                                 goto out_invalid_data;
1097
1098                 /*
1099                  * Translate to nfs_fs_context, which nfs_fill_super
1100                  * can deal with.
1101                  */
1102                 ctx->flags      = data->flags & NFS_MOUNT_FLAGMASK;
1103                 ctx->flags      |= extra_flags;
1104                 ctx->rsize      = data->rsize;
1105                 ctx->wsize      = data->wsize;
1106                 ctx->timeo      = data->timeo;
1107                 ctx->retrans    = data->retrans;
1108                 ctx->acregmin   = data->acregmin;
1109                 ctx->acregmax   = data->acregmax;
1110                 ctx->acdirmin   = data->acdirmin;
1111                 ctx->acdirmax   = data->acdirmax;
1112                 ctx->need_mount = false;
1113
1114                 memcpy(sap, &data->addr, sizeof(data->addr));
1115                 ctx->nfs_server.addrlen = sizeof(data->addr);
1116                 ctx->nfs_server.port = ntohs(data->addr.sin_port);
1117                 if (sap->ss_family != AF_INET ||
1118                     !nfs_verify_server_address(sap))
1119                         goto out_no_address;
1120
1121                 if (!(data->flags & NFS_MOUNT_TCP))
1122                         ctx->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1123                 /* N.B. caller will free nfs_server.hostname in all cases */
1124                 ctx->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1125                 if (!ctx->nfs_server.hostname)
1126                         goto out_nomem;
1127
1128                 ctx->namlen             = data->namlen;
1129                 ctx->bsize              = data->bsize;
1130
1131                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1132                         ctx->selected_flavor = data->pseudoflavor;
1133                 else
1134                         ctx->selected_flavor = RPC_AUTH_UNIX;
1135
1136                 if (!(data->flags & NFS_MOUNT_NONLM))
1137                         ctx->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
1138                                          NFS_MOUNT_LOCAL_FCNTL);
1139                 else
1140                         ctx->flags |= (NFS_MOUNT_LOCAL_FLOCK|
1141                                         NFS_MOUNT_LOCAL_FCNTL);
1142
1143                 /*
1144                  * The legacy version 6 binary mount data from userspace has a
1145                  * field used only to transport selinux information into the
1146                  * kernel.  To continue to support that functionality we
1147                  * have a touch of selinux knowledge here in the NFS code. The
1148                  * userspace code converted context=blah to just blah so we are
1149                  * converting back to the full string selinux understands.
1150                  */
1151                 if (data->context[0]){
1152 #ifdef CONFIG_SECURITY_SELINUX
1153                         int ret;
1154
1155                         data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1156                         ret = vfs_parse_fs_string(fc, "context",
1157                                                   data->context, strlen(data->context));
1158                         if (ret < 0)
1159                                 return ret;
1160 #else
1161                         return -EINVAL;
1162 #endif
1163                 }
1164
1165                 break;
1166         default:
1167                 goto generic;
1168         }
1169
1170         ret = nfs_validate_transport_protocol(fc, ctx);
1171         if (ret)
1172                 return ret;
1173
1174         ctx->skip_reconfig_option_check = true;
1175         return 0;
1176
1177 generic:
1178         return generic_parse_monolithic(fc, data);
1179
1180 out_no_data:
1181         if (is_remount_fc(fc)) {
1182                 ctx->skip_reconfig_option_check = true;
1183                 return 0;
1184         }
1185         return nfs_invalf(fc, "NFS: mount program didn't pass any mount data");
1186
1187 out_no_v3:
1188         return nfs_invalf(fc, "NFS: nfs_mount_data version does not support v3");
1189
1190 out_no_sec:
1191         return nfs_invalf(fc, "NFS: nfs_mount_data version supports only AUTH_SYS");
1192
1193 out_nomem:
1194         return -ENOMEM;
1195
1196 out_no_address:
1197         return nfs_invalf(fc, "NFS: mount program didn't pass remote address");
1198
1199 out_invalid_fh:
1200         return nfs_invalf(fc, "NFS: invalid root filehandle");
1201
1202 out_invalid_data:
1203         return nfs_invalf(fc, "NFS: invalid binary mount data");
1204 }
1205
1206 #if IS_ENABLED(CONFIG_NFS_V4)
1207 struct compat_nfs_string {
1208         compat_uint_t len;
1209         compat_uptr_t data;
1210 };
1211
1212 static inline void compat_nfs_string(struct nfs_string *dst,
1213                                      struct compat_nfs_string *src)
1214 {
1215         dst->data = compat_ptr(src->data);
1216         dst->len = src->len;
1217 }
1218
1219 struct compat_nfs4_mount_data_v1 {
1220         compat_int_t version;
1221         compat_int_t flags;
1222         compat_int_t rsize;
1223         compat_int_t wsize;
1224         compat_int_t timeo;
1225         compat_int_t retrans;
1226         compat_int_t acregmin;
1227         compat_int_t acregmax;
1228         compat_int_t acdirmin;
1229         compat_int_t acdirmax;
1230         struct compat_nfs_string client_addr;
1231         struct compat_nfs_string mnt_path;
1232         struct compat_nfs_string hostname;
1233         compat_uint_t host_addrlen;
1234         compat_uptr_t host_addr;
1235         compat_int_t proto;
1236         compat_int_t auth_flavourlen;
1237         compat_uptr_t auth_flavours;
1238 };
1239
1240 static void nfs4_compat_mount_data_conv(struct nfs4_mount_data *data)
1241 {
1242         struct compat_nfs4_mount_data_v1 *compat =
1243                         (struct compat_nfs4_mount_data_v1 *)data;
1244
1245         /* copy the fields backwards */
1246         data->auth_flavours = compat_ptr(compat->auth_flavours);
1247         data->auth_flavourlen = compat->auth_flavourlen;
1248         data->proto = compat->proto;
1249         data->host_addr = compat_ptr(compat->host_addr);
1250         data->host_addrlen = compat->host_addrlen;
1251         compat_nfs_string(&data->hostname, &compat->hostname);
1252         compat_nfs_string(&data->mnt_path, &compat->mnt_path);
1253         compat_nfs_string(&data->client_addr, &compat->client_addr);
1254         data->acdirmax = compat->acdirmax;
1255         data->acdirmin = compat->acdirmin;
1256         data->acregmax = compat->acregmax;
1257         data->acregmin = compat->acregmin;
1258         data->retrans = compat->retrans;
1259         data->timeo = compat->timeo;
1260         data->wsize = compat->wsize;
1261         data->rsize = compat->rsize;
1262         data->flags = compat->flags;
1263         data->version = compat->version;
1264 }
1265
1266 /*
1267  * Validate NFSv4 mount options
1268  */
1269 static int nfs4_parse_monolithic(struct fs_context *fc,
1270                                  struct nfs4_mount_data *data)
1271 {
1272         struct nfs_fs_context *ctx = nfs_fc2context(fc);
1273         struct sockaddr_storage *sap = &ctx->nfs_server._address;
1274         int ret;
1275         char *c;
1276
1277         if (!data) {
1278                 if (is_remount_fc(fc))
1279                         goto done;
1280                 return nfs_invalf(fc,
1281                         "NFS4: mount program didn't pass any mount data");
1282         }
1283
1284         ctx->version = 4;
1285
1286         if (data->version != 1)
1287                 return generic_parse_monolithic(fc, data);
1288
1289         if (in_compat_syscall())
1290                 nfs4_compat_mount_data_conv(data);
1291
1292         if (data->host_addrlen > sizeof(ctx->nfs_server.address))
1293                 goto out_no_address;
1294         if (data->host_addrlen == 0)
1295                 goto out_no_address;
1296         ctx->nfs_server.addrlen = data->host_addrlen;
1297         if (copy_from_user(sap, data->host_addr, data->host_addrlen))
1298                 return -EFAULT;
1299         if (!nfs_verify_server_address(sap))
1300                 goto out_no_address;
1301         ctx->nfs_server.port = ntohs(((struct sockaddr_in *)sap)->sin_port);
1302
1303         if (data->auth_flavourlen) {
1304                 rpc_authflavor_t pseudoflavor;
1305
1306                 if (data->auth_flavourlen > 1)
1307                         goto out_inval_auth;
1308                 if (copy_from_user(&pseudoflavor, data->auth_flavours,
1309                                    sizeof(pseudoflavor)))
1310                         return -EFAULT;
1311                 ctx->selected_flavor = pseudoflavor;
1312         } else {
1313                 ctx->selected_flavor = RPC_AUTH_UNIX;
1314         }
1315
1316         c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
1317         if (IS_ERR(c))
1318                 return PTR_ERR(c);
1319         ctx->nfs_server.hostname = c;
1320
1321         c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
1322         if (IS_ERR(c))
1323                 return PTR_ERR(c);
1324         ctx->nfs_server.export_path = c;
1325         trace_nfs_mount_path(c);
1326
1327         c = strndup_user(data->client_addr.data, 16);
1328         if (IS_ERR(c))
1329                 return PTR_ERR(c);
1330         ctx->client_address = c;
1331
1332         /*
1333          * Translate to nfs_fs_context, which nfs_fill_super
1334          * can deal with.
1335          */
1336
1337         ctx->flags      = data->flags & NFS4_MOUNT_FLAGMASK;
1338         ctx->rsize      = data->rsize;
1339         ctx->wsize      = data->wsize;
1340         ctx->timeo      = data->timeo;
1341         ctx->retrans    = data->retrans;
1342         ctx->acregmin   = data->acregmin;
1343         ctx->acregmax   = data->acregmax;
1344         ctx->acdirmin   = data->acdirmin;
1345         ctx->acdirmax   = data->acdirmax;
1346         ctx->nfs_server.protocol = data->proto;
1347         ret = nfs_validate_transport_protocol(fc, ctx);
1348         if (ret)
1349                 return ret;
1350 done:
1351         ctx->skip_reconfig_option_check = true;
1352         return 0;
1353
1354 out_inval_auth:
1355         return nfs_invalf(fc, "NFS4: Invalid number of RPC auth flavours %d",
1356                       data->auth_flavourlen);
1357
1358 out_no_address:
1359         return nfs_invalf(fc, "NFS4: mount program didn't pass remote address");
1360 }
1361 #endif
1362
1363 /*
1364  * Parse a monolithic block of data from sys_mount().
1365  */
1366 static int nfs_fs_context_parse_monolithic(struct fs_context *fc,
1367                                            void *data)
1368 {
1369         if (fc->fs_type == &nfs_fs_type)
1370                 return nfs23_parse_monolithic(fc, data);
1371
1372 #if IS_ENABLED(CONFIG_NFS_V4)
1373         if (fc->fs_type == &nfs4_fs_type)
1374                 return nfs4_parse_monolithic(fc, data);
1375 #endif
1376
1377         return nfs_invalf(fc, "NFS: Unsupported monolithic data version");
1378 }
1379
1380 /*
1381  * Validate the preparsed information in the config.
1382  */
1383 static int nfs_fs_context_validate(struct fs_context *fc)
1384 {
1385         struct nfs_fs_context *ctx = nfs_fc2context(fc);
1386         struct nfs_subversion *nfs_mod;
1387         struct sockaddr_storage *sap = &ctx->nfs_server._address;
1388         int max_namelen = PAGE_SIZE;
1389         int max_pathlen = NFS_MAXPATHLEN;
1390         int port = 0;
1391         int ret;
1392
1393         if (!fc->source)
1394                 goto out_no_device_name;
1395
1396         /* Check for sanity first. */
1397         if (ctx->minorversion && ctx->version != 4)
1398                 goto out_minorversion_mismatch;
1399
1400         if (ctx->options & NFS_OPTION_MIGRATION &&
1401             (ctx->version != 4 || ctx->minorversion != 0))
1402                 goto out_migration_misuse;
1403
1404         /* Verify that any proto=/mountproto= options match the address
1405          * families in the addr=/mountaddr= options.
1406          */
1407         if (ctx->protofamily != AF_UNSPEC &&
1408             ctx->protofamily != ctx->nfs_server.address.sa_family)
1409                 goto out_proto_mismatch;
1410
1411         if (ctx->mountfamily != AF_UNSPEC) {
1412                 if (ctx->mount_server.addrlen) {
1413                         if (ctx->mountfamily != ctx->mount_server.address.sa_family)
1414                                 goto out_mountproto_mismatch;
1415                 } else {
1416                         if (ctx->mountfamily != ctx->nfs_server.address.sa_family)
1417                                 goto out_mountproto_mismatch;
1418                 }
1419         }
1420
1421         if (!nfs_verify_server_address(sap))
1422                 goto out_no_address;
1423
1424         ret = nfs_validate_transport_protocol(fc, ctx);
1425         if (ret)
1426                 return ret;
1427
1428         if (ctx->version == 4) {
1429                 if (IS_ENABLED(CONFIG_NFS_V4)) {
1430                         if (ctx->nfs_server.protocol == XPRT_TRANSPORT_RDMA)
1431                                 port = NFS_RDMA_PORT;
1432                         else
1433                                 port = NFS_PORT;
1434                         max_namelen = NFS4_MAXNAMLEN;
1435                         max_pathlen = NFS4_MAXPATHLEN;
1436                         ctx->flags &= ~(NFS_MOUNT_NONLM | NFS_MOUNT_NOACL |
1437                                         NFS_MOUNT_VER3 | NFS_MOUNT_LOCAL_FLOCK |
1438                                         NFS_MOUNT_LOCAL_FCNTL);
1439                 } else {
1440                         goto out_v4_not_compiled;
1441                 }
1442         } else {
1443                 nfs_set_mount_transport_protocol(ctx);
1444                 if (ctx->nfs_server.protocol == XPRT_TRANSPORT_RDMA)
1445                         port = NFS_RDMA_PORT;
1446         }
1447
1448         nfs_set_port(sap, &ctx->nfs_server.port, port);
1449
1450         ret = nfs_parse_source(fc, max_namelen, max_pathlen);
1451         if (ret < 0)
1452                 return ret;
1453
1454         /* Load the NFS protocol module if we haven't done so yet */
1455         if (!ctx->nfs_mod) {
1456                 nfs_mod = get_nfs_version(ctx->version);
1457                 if (IS_ERR(nfs_mod)) {
1458                         ret = PTR_ERR(nfs_mod);
1459                         goto out_version_unavailable;
1460                 }
1461                 ctx->nfs_mod = nfs_mod;
1462         }
1463
1464         /* Ensure the filesystem context has the correct fs_type */
1465         if (fc->fs_type != ctx->nfs_mod->nfs_fs) {
1466                 module_put(fc->fs_type->owner);
1467                 __module_get(ctx->nfs_mod->nfs_fs->owner);
1468                 fc->fs_type = ctx->nfs_mod->nfs_fs;
1469         }
1470         return 0;
1471
1472 out_no_device_name:
1473         return nfs_invalf(fc, "NFS: Device name not specified");
1474 out_v4_not_compiled:
1475         nfs_errorf(fc, "NFS: NFSv4 is not compiled into kernel");
1476         return -EPROTONOSUPPORT;
1477 out_no_address:
1478         return nfs_invalf(fc, "NFS: mount program didn't pass remote address");
1479 out_mountproto_mismatch:
1480         return nfs_invalf(fc, "NFS: Mount server address does not match mountproto= option");
1481 out_proto_mismatch:
1482         return nfs_invalf(fc, "NFS: Server address does not match proto= option");
1483 out_minorversion_mismatch:
1484         return nfs_invalf(fc, "NFS: Mount option vers=%u does not support minorversion=%u",
1485                           ctx->version, ctx->minorversion);
1486 out_migration_misuse:
1487         return nfs_invalf(fc, "NFS: 'Migration' not supported for this NFS version");
1488 out_version_unavailable:
1489         nfs_errorf(fc, "NFS: Version unavailable");
1490         return ret;
1491 }
1492
1493 /*
1494  * Create an NFS superblock by the appropriate method.
1495  */
1496 static int nfs_get_tree(struct fs_context *fc)
1497 {
1498         struct nfs_fs_context *ctx = nfs_fc2context(fc);
1499         int err = nfs_fs_context_validate(fc);
1500
1501         if (err)
1502                 return err;
1503         if (!ctx->internal)
1504                 return ctx->nfs_mod->rpc_ops->try_get_tree(fc);
1505         else
1506                 return nfs_get_tree_common(fc);
1507 }
1508
1509 /*
1510  * Handle duplication of a configuration.  The caller copied *src into *sc, but
1511  * it can't deal with resource pointers in the filesystem context, so we have
1512  * to do that.  We need to clear pointers, copy data or get extra refs as
1513  * appropriate.
1514  */
1515 static int nfs_fs_context_dup(struct fs_context *fc, struct fs_context *src_fc)
1516 {
1517         struct nfs_fs_context *src = nfs_fc2context(src_fc), *ctx;
1518
1519         ctx = kmemdup(src, sizeof(struct nfs_fs_context), GFP_KERNEL);
1520         if (!ctx)
1521                 return -ENOMEM;
1522
1523         ctx->mntfh = nfs_alloc_fhandle();
1524         if (!ctx->mntfh) {
1525                 kfree(ctx);
1526                 return -ENOMEM;
1527         }
1528         nfs_copy_fh(ctx->mntfh, src->mntfh);
1529
1530         __module_get(ctx->nfs_mod->owner);
1531         ctx->client_address             = NULL;
1532         ctx->mount_server.hostname      = NULL;
1533         ctx->nfs_server.export_path     = NULL;
1534         ctx->nfs_server.hostname        = NULL;
1535         ctx->fscache_uniq               = NULL;
1536         ctx->clone_data.fattr           = NULL;
1537         fc->fs_private = ctx;
1538         return 0;
1539 }
1540
1541 static void nfs_fs_context_free(struct fs_context *fc)
1542 {
1543         struct nfs_fs_context *ctx = nfs_fc2context(fc);
1544
1545         if (ctx) {
1546                 if (ctx->server)
1547                         nfs_free_server(ctx->server);
1548                 if (ctx->nfs_mod)
1549                         put_nfs_version(ctx->nfs_mod);
1550                 kfree(ctx->client_address);
1551                 kfree(ctx->mount_server.hostname);
1552                 kfree(ctx->nfs_server.export_path);
1553                 kfree(ctx->nfs_server.hostname);
1554                 kfree(ctx->fscache_uniq);
1555                 nfs_free_fhandle(ctx->mntfh);
1556                 nfs_free_fattr(ctx->clone_data.fattr);
1557                 kfree(ctx);
1558         }
1559 }
1560
1561 static const struct fs_context_operations nfs_fs_context_ops = {
1562         .free                   = nfs_fs_context_free,
1563         .dup                    = nfs_fs_context_dup,
1564         .parse_param            = nfs_fs_context_parse_param,
1565         .parse_monolithic       = nfs_fs_context_parse_monolithic,
1566         .get_tree               = nfs_get_tree,
1567         .reconfigure            = nfs_reconfigure,
1568 };
1569
1570 /*
1571  * Prepare superblock configuration.  We use the namespaces attached to the
1572  * context.  This may be the current process's namespaces, or it may be a
1573  * container's namespaces.
1574  */
1575 static int nfs_init_fs_context(struct fs_context *fc)
1576 {
1577         struct nfs_fs_context *ctx;
1578
1579         ctx = kzalloc(sizeof(struct nfs_fs_context), GFP_KERNEL);
1580         if (unlikely(!ctx))
1581                 return -ENOMEM;
1582
1583         ctx->mntfh = nfs_alloc_fhandle();
1584         if (unlikely(!ctx->mntfh)) {
1585                 kfree(ctx);
1586                 return -ENOMEM;
1587         }
1588
1589         ctx->protofamily        = AF_UNSPEC;
1590         ctx->mountfamily        = AF_UNSPEC;
1591         ctx->mount_server.port  = NFS_UNSPEC_PORT;
1592
1593         if (fc->root) {
1594                 /* reconfigure, start with the current config */
1595                 struct nfs_server *nfss = fc->root->d_sb->s_fs_info;
1596                 struct net *net = nfss->nfs_client->cl_net;
1597
1598                 ctx->flags              = nfss->flags;
1599                 ctx->rsize              = nfss->rsize;
1600                 ctx->wsize              = nfss->wsize;
1601                 ctx->retrans            = nfss->client->cl_timeout->to_retries;
1602                 ctx->selected_flavor    = nfss->client->cl_auth->au_flavor;
1603                 ctx->acregmin           = nfss->acregmin / HZ;
1604                 ctx->acregmax           = nfss->acregmax / HZ;
1605                 ctx->acdirmin           = nfss->acdirmin / HZ;
1606                 ctx->acdirmax           = nfss->acdirmax / HZ;
1607                 ctx->timeo              = 10U * nfss->client->cl_timeout->to_initval / HZ;
1608                 ctx->nfs_server.port    = nfss->port;
1609                 ctx->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
1610                 ctx->version            = nfss->nfs_client->rpc_ops->version;
1611                 ctx->minorversion       = nfss->nfs_client->cl_minorversion;
1612
1613                 memcpy(&ctx->nfs_server._address, &nfss->nfs_client->cl_addr,
1614                         ctx->nfs_server.addrlen);
1615
1616                 if (fc->net_ns != net) {
1617                         put_net(fc->net_ns);
1618                         fc->net_ns = get_net(net);
1619                 }
1620
1621                 ctx->nfs_mod = nfss->nfs_client->cl_nfs_mod;
1622                 __module_get(ctx->nfs_mod->owner);
1623         } else {
1624                 /* defaults */
1625                 ctx->timeo              = NFS_UNSPEC_TIMEO;
1626                 ctx->retrans            = NFS_UNSPEC_RETRANS;
1627                 ctx->acregmin           = NFS_DEF_ACREGMIN;
1628                 ctx->acregmax           = NFS_DEF_ACREGMAX;
1629                 ctx->acdirmin           = NFS_DEF_ACDIRMIN;
1630                 ctx->acdirmax           = NFS_DEF_ACDIRMAX;
1631                 ctx->nfs_server.port    = NFS_UNSPEC_PORT;
1632                 ctx->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1633                 ctx->selected_flavor    = RPC_AUTH_MAXFLAVOR;
1634                 ctx->minorversion       = 0;
1635                 ctx->need_mount         = true;
1636                 ctx->xprtsec.policy     = RPC_XPRTSEC_NONE;
1637                 ctx->xprtsec.cert_serial        = TLS_NO_CERT;
1638                 ctx->xprtsec.privkey_serial     = TLS_NO_PRIVKEY;
1639
1640                 fc->s_iflags            |= SB_I_STABLE_WRITES;
1641         }
1642         fc->fs_private = ctx;
1643         fc->ops = &nfs_fs_context_ops;
1644         return 0;
1645 }
1646
1647 struct file_system_type nfs_fs_type = {
1648         .owner                  = THIS_MODULE,
1649         .name                   = "nfs",
1650         .init_fs_context        = nfs_init_fs_context,
1651         .parameters             = nfs_fs_parameters,
1652         .kill_sb                = nfs_kill_super,
1653         .fs_flags               = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
1654 };
1655 MODULE_ALIAS_FS("nfs");
1656 EXPORT_SYMBOL_GPL(nfs_fs_type);
1657
1658 #if IS_ENABLED(CONFIG_NFS_V4)
1659 struct file_system_type nfs4_fs_type = {
1660         .owner                  = THIS_MODULE,
1661         .name                   = "nfs4",
1662         .init_fs_context        = nfs_init_fs_context,
1663         .parameters             = nfs_fs_parameters,
1664         .kill_sb                = nfs_kill_super,
1665         .fs_flags               = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
1666 };
1667 MODULE_ALIAS_FS("nfs4");
1668 MODULE_ALIAS("nfs4");
1669 EXPORT_SYMBOL_GPL(nfs4_fs_type);
1670 #endif /* CONFIG_NFS_V4 */