fs/nfs/mount_clnt.c

   1 /*
   2  * In-kernel MOUNT protocol client
   3  *
   4  * Copyright (C) 1997, Olaf Kirch <okir@monad.swb.de>
   5  */
   6
   7 #include <linux/types.h>
   8 #include <linux/socket.h>
   9 #include <linux/kernel.h>
  10 #include <linux/errno.h>
  11 #include <linux/uio.h>
  12 #include <linux/net.h>
  13 #include <linux/in.h>
  14 #include <linux/sunrpc/clnt.h>
  15 #include <linux/sunrpc/sched.h>
  16 #include <linux/nfs_fs.h>
  17 #include "internal.h"
  18
  19 #define NFSDBG_FACILITY NFSDBG_MOUNT
  20
  21 /*
  22  * Defined by RFC 1094, section A.3; and RFC 1813, section 5.1.4
  23  */
  24 #define MNTPATHLEN              (1024)
  25
  26 /*
  27  * XDR data type sizes
  28  */
  29 #define encode_dirpath_sz       (1 + XDR_QUADLEN(MNTPATHLEN))
  30 #define MNT_status_sz           (1)
  31 #define MNT_fhs_status_sz       (1)
  32 #define MNT_fhandle_sz          XDR_QUADLEN(NFS2_FHSIZE)
  33 #define MNT_fhandle3_sz         (1 + XDR_QUADLEN(NFS3_FHSIZE))
  34 #define MNT_authflav3_sz        (1 + NFS_MAX_SECFLAVORS)
  35
  36 /*
  37  * XDR argument and result sizes
  38  */
  39 #define MNT_enc_dirpath_sz      encode_dirpath_sz
  40 #define MNT_dec_mountres_sz     (MNT_status_sz + MNT_fhandle_sz)
  41 #define MNT_dec_mountres3_sz    (MNT_status_sz + MNT_fhandle_sz + \
  42                                  MNT_authflav3_sz)
  43
  44 /*
  45  * Defined by RFC 1094, section A.5
  46  */
  47 enum {
  48         MOUNTPROC_NULL          = 0,
  49         MOUNTPROC_MNT           = 1,
  50         MOUNTPROC_DUMP          = 2,
  51         MOUNTPROC_UMNT          = 3,
  52         MOUNTPROC_UMNTALL       = 4,
  53         MOUNTPROC_EXPORT        = 5,
  54 };
  55
  56 /*
  57  * Defined by RFC 1813, section 5.2
  58  */
  59 enum {
  60         MOUNTPROC3_NULL         = 0,
  61         MOUNTPROC3_MNT          = 1,
  62         MOUNTPROC3_DUMP         = 2,
  63         MOUNTPROC3_UMNT         = 3,
  64         MOUNTPROC3_UMNTALL      = 4,
  65         MOUNTPROC3_EXPORT       = 5,
  66 };
  67
  68 static const struct rpc_program mnt_program;
  69
  70 /*
  71  * Defined by OpenGroup XNFS Version 3W, chapter 8
  72  */
  73 enum mountstat {
  74         MNT_OK                  = 0,
  75         MNT_EPERM               = 1,
  76         MNT_ENOENT              = 2,
  77         MNT_EACCES              = 13,
  78         MNT_EINVAL              = 22,
  79 };
  80
  81 static struct {
  82         u32 status;
  83         int errno;
  84 } mnt_errtbl[] = {
  85         { .status = MNT_OK,                     .errno = 0,             },
  86         { .status = MNT_EPERM,                  .errno = -EPERM,        },
  87         { .status = MNT_ENOENT,                 .errno = -ENOENT,       },
  88         { .status = MNT_EACCES,                 .errno = -EACCES,       },
  89         { .status = MNT_EINVAL,                 .errno = -EINVAL,       },
  90 };
  91
  92 /*
  93  * Defined by RFC 1813, section 5.1.5
  94  */
  95 enum mountstat3 {
  96         MNT3_OK                 = 0,            /* no error */
  97         MNT3ERR_PERM            = 1,            /* Not owner */
  98         MNT3ERR_NOENT           = 2,            /* No such file or directory */
  99         MNT3ERR_IO              = 5,            /* I/O error */
 100         MNT3ERR_ACCES           = 13,           /* Permission denied */
 101         MNT3ERR_NOTDIR          = 20,           /* Not a directory */
 102         MNT3ERR_INVAL           = 22,           /* Invalid argument */
 103         MNT3ERR_NAMETOOLONG     = 63,           /* Filename too long */
 104         MNT3ERR_NOTSUPP         = 10004,        /* Operation not supported */
 105         MNT3ERR_SERVERFAULT     = 10006,        /* A failure on the server */
 106 };
 107
 108 static struct {
 109         u32 status;
 110         int errno;
 111 } mnt3_errtbl[] = {
 112         { .status = MNT3_OK,                    .errno = 0,             },
 113         { .status = MNT3ERR_PERM,               .errno = -EPERM,        },
 114         { .status = MNT3ERR_NOENT,              .errno = -ENOENT,       },
 115         { .status = MNT3ERR_IO,                 .errno = -EIO,          },
 116         { .status = MNT3ERR_ACCES,              .errno = -EACCES,       },
 117         { .status = MNT3ERR_NOTDIR,             .errno = -ENOTDIR,      },
 118         { .status = MNT3ERR_INVAL,              .errno = -EINVAL,       },
 119         { .status = MNT3ERR_NAMETOOLONG,        .errno = -ENAMETOOLONG, },
 120         { .status = MNT3ERR_NOTSUPP,            .errno = -ENOTSUPP,     },
 121         { .status = MNT3ERR_SERVERFAULT,        .errno = -EREMOTEIO,    },
 122 };
 123
 124 struct mountres {
 125         int errno;
 126         struct nfs_fh *fh;
 127         unsigned int *auth_count;
 128         rpc_authflavor_t *auth_flavors;
 129 };
 130
 131 struct mnt_fhstatus {
 132         u32 status;
 133         struct nfs_fh *fh;
 134 };
 135
 136 /**
 137  * nfs_mount - Obtain an NFS file handle for the given host and path
 138  * @info: pointer to mount request arguments
 139  *
 140  * Uses default timeout parameters specified by underlying transport. On
 141  * successful return, the auth_flavs list and auth_flav_len will be populated
 142  * with the list from the server or a faked-up list if the server didn't
 143  * provide one.
 144  */
 145 int nfs_mount(struct nfs_mount_request *info)
 146 {
 147         struct mountres result = {
 148                 .fh             = info->fh,
 149                 .auth_count     = info->auth_flav_len,
 150                 .auth_flavors   = info->auth_flavs,
 151         };
 152         struct rpc_message msg  = {
 153                 .rpc_argp       = info->dirpath,
 154                 .rpc_resp       = &result,
 155         };
 156         struct rpc_create_args args = {
 157                 .net            = info->net,
 158                 .protocol       = info->protocol,
 159                 .address        = info->sap,
 160                 .addrsize       = info->salen,
 161                 .servername     = info->hostname,
 162                 .program        = &mnt_program,
 163                 .version        = info->version,
 164                 .authflavor     = RPC_AUTH_UNIX,
 165         };
 166         struct rpc_clnt         *mnt_clnt;
 167         int                     status;
 168
 169         dprintk("NFS: sending MNT request for %s:%s\n",
 170                 (info->hostname ? info->hostname : "server"),
 171                         info->dirpath);
 172
 173         if (strlen(info->dirpath) > MNTPATHLEN)
 174                 return -ENAMETOOLONG;
 175
 176         if (info->noresvport)
 177                 args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
 178
 179         mnt_clnt = rpc_create(&args);
 180         if (IS_ERR(mnt_clnt))
 181                 goto out_clnt_err;
 182
 183         if (info->version == NFS_MNT3_VERSION)
 184                 msg.rpc_proc = &mnt_clnt->cl_procinfo[MOUNTPROC3_MNT];
 185         else
 186                 msg.rpc_proc = &mnt_clnt->cl_procinfo[MOUNTPROC_MNT];
 187
 188         status = rpc_call_sync(mnt_clnt, &msg, RPC_TASK_SOFT|RPC_TASK_TIMEOUT);
 189         rpc_shutdown_client(mnt_clnt);
 190
 191         if (status < 0)
 192                 goto out_call_err;
 193         if (result.errno != 0)
 194                 goto out_mnt_err;
 195
 196         dprintk("NFS: MNT request succeeded\n");
 197         status = 0;
 198
 199         /*
 200          * If the server didn't provide a flavor list, allow the
 201          * client to try any flavor.
 202          */
 203         if (info->version != NFS_MNT3_VERSION || *info->auth_flav_len == 0) {
 204                 dprintk("NFS: Faking up auth_flavs list\n");
 205                 info->auth_flavs[0] = RPC_AUTH_NULL;
 206                 *info->auth_flav_len = 1;
 207         }
 208 out:
 209         return status;
 210
 211 out_clnt_err:
 212         status = PTR_ERR(mnt_clnt);
 213         dprintk("NFS: failed to create MNT RPC client, status=%d\n", status);
 214         goto out;
 215
 216 out_call_err:
 217         dprintk("NFS: MNT request failed, status=%d\n", status);
 218         goto out;
 219
 220 out_mnt_err:
 221         dprintk("NFS: MNT server returned result %d\n", result.errno);
 222         status = result.errno;
 223         goto out;
 224 }
 225
 226 /**
 227  * nfs_umount - Notify a server that we have unmounted this export
 228  * @info: pointer to umount request arguments
 229  *
 230  * MOUNTPROC_UMNT is advisory, so we set a short timeout, and always
 231  * use UDP.
 232  */
 233 void nfs_umount(const struct nfs_mount_request *info)
 234 {
 235         static const struct rpc_timeout nfs_umnt_timeout = {
 236                 .to_initval = 1 * HZ,
 237                 .to_maxval = 3 * HZ,
 238                 .to_retries = 2,
 239         };
 240         struct rpc_create_args args = {
 241                 .net            = info->net,
 242                 .protocol       = IPPROTO_UDP,
 243                 .address        = info->sap,
 244                 .addrsize       = info->salen,
 245                 .timeout        = &nfs_umnt_timeout,
 246                 .servername     = info->hostname,
 247                 .program        = &mnt_program,
 248                 .version        = info->version,
 249                 .authflavor     = RPC_AUTH_UNIX,
 250                 .flags          = RPC_CLNT_CREATE_NOPING,
 251         };
 252         struct rpc_message msg  = {
 253                 .rpc_argp       = info->dirpath,
 254         };
 255         struct rpc_clnt *clnt;
 256         int status;
 257
 258         if (strlen(info->dirpath) > MNTPATHLEN)
 259                 return;
 260
 261         if (info->noresvport)
 262                 args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
 263
 264         clnt = rpc_create(&args);
 265         if (IS_ERR(clnt))
 266                 goto out_clnt_err;
 267
 268         dprintk("NFS: sending UMNT request for %s:%s\n",
 269                 (info->hostname ? info->hostname : "server"), info->dirpath);
 270
 271         if (info->version == NFS_MNT3_VERSION)
 272                 msg.rpc_proc = &clnt->cl_procinfo[MOUNTPROC3_UMNT];
 273         else
 274                 msg.rpc_proc = &clnt->cl_procinfo[MOUNTPROC_UMNT];
 275
 276         status = rpc_call_sync(clnt, &msg, 0);
 277         rpc_shutdown_client(clnt);
 278
 279         if (unlikely(status < 0))
 280                 goto out_call_err;
 281
 282         return;
 283
 284 out_clnt_err:
 285         dprintk("NFS: failed to create UMNT RPC client, status=%ld\n",
 286                         PTR_ERR(clnt));
 287         return;
 288
 289 out_call_err:
 290         dprintk("NFS: UMNT request failed, status=%d\n", status);
 291 }
 292
 293 /*
 294  * XDR encode/decode functions for MOUNT
 295  */
 296
 297 static void encode_mntdirpath(struct xdr_stream *xdr, const char *pathname)
 298 {
 299         const u32 pathname_len = strlen(pathname);
 300         __be32 *p;
 301
 302         p = xdr_reserve_space(xdr, 4 + pathname_len);
 303         xdr_encode_opaque(p, pathname, pathname_len);
 304 }
 305
 306 static void mnt_xdr_enc_dirpath(struct rpc_rqst *req, struct xdr_stream *xdr,
 307                                 const char *dirpath)
 308 {
 309         encode_mntdirpath(xdr, dirpath);
 310 }
 311
 312 /*
 313  * RFC 1094: "A non-zero status indicates some sort of error.  In this
 314  * case, the status is a UNIX error number."  This can be problematic
 315  * if the server and client use different errno values for the same
 316  * error.
 317  *
 318  * However, the OpenGroup XNFS spec provides a simple mapping that is
 319  * independent of local errno values on the server and the client.
 320  */
 321 static int decode_status(struct xdr_stream *xdr, struct mountres *res)
 322 {
 323         unsigned int i;
 324         u32 status;
 325         __be32 *p;
 326
 327         p = xdr_inline_decode(xdr, 4);
 328         if (unlikely(p == NULL))
 329                 return -EIO;
 330         status = be32_to_cpup(p);
 331
 332         for (i = 0; i < ARRAY_SIZE(mnt_errtbl); i++) {
 333                 if (mnt_errtbl[i].status == status) {
 334                         res->errno = mnt_errtbl[i].errno;
 335                         return 0;
 336                 }
 337         }
 338
 339         dprintk("NFS: unrecognized MNT status code: %u\n", status);
 340         res->errno = -EACCES;
 341         return 0;
 342 }
 343
 344 static int decode_fhandle(struct xdr_stream *xdr, struct mountres *res)
 345 {
 346         struct nfs_fh *fh = res->fh;
 347         __be32 *p;
 348
 349         p = xdr_inline_decode(xdr, NFS2_FHSIZE);
 350         if (unlikely(p == NULL))
 351                 return -EIO;
 352
 353         fh->size = NFS2_FHSIZE;
 354         memcpy(fh->data, p, NFS2_FHSIZE);
 355         return 0;
 356 }
 357
 358 static int mnt_xdr_dec_mountres(struct rpc_rqst *req,
 359                                 struct xdr_stream *xdr,
 360                                 struct mountres *res)
 361 {
 362         int status;
 363
 364         status = decode_status(xdr, res);
 365         if (unlikely(status != 0 || res->errno != 0))
 366                 return status;
 367         return decode_fhandle(xdr, res);
 368 }
 369
 370 static int decode_fhs_status(struct xdr_stream *xdr, struct mountres *res)
 371 {
 372         unsigned int i;
 373         u32 status;
 374         __be32 *p;
 375
 376         p = xdr_inline_decode(xdr, 4);
 377         if (unlikely(p == NULL))
 378                 return -EIO;
 379         status = be32_to_cpup(p);
 380
 381         for (i = 0; i < ARRAY_SIZE(mnt3_errtbl); i++) {
 382                 if (mnt3_errtbl[i].status == status) {
 383                         res->errno = mnt3_errtbl[i].errno;
 384                         return 0;
 385                 }
 386         }
 387
 388         dprintk("NFS: unrecognized MNT3 status code: %u\n", status);
 389         res->errno = -EACCES;
 390         return 0;
 391 }
 392
 393 static int decode_fhandle3(struct xdr_stream *xdr, struct mountres *res)
 394 {
 395         struct nfs_fh *fh = res->fh;
 396         u32 size;
 397         __be32 *p;
 398
 399         p = xdr_inline_decode(xdr, 4);
 400         if (unlikely(p == NULL))
 401                 return -EIO;
 402
 403         size = be32_to_cpup(p);
 404         if (size > NFS3_FHSIZE || size == 0)
 405                 return -EIO;
 406
 407         p = xdr_inline_decode(xdr, size);
 408         if (unlikely(p == NULL))
 409                 return -EIO;
 410
 411         fh->size = size;
 412         memcpy(fh->data, p, size);
 413         return 0;
 414 }
 415
 416 static int decode_auth_flavors(struct xdr_stream *xdr, struct mountres *res)
 417 {
 418         rpc_authflavor_t *flavors = res->auth_flavors;
 419         unsigned int *count = res->auth_count;
 420         u32 entries, i;
 421         __be32 *p;
 422
 423         if (*count == 0)
 424                 return 0;
 425
 426         p = xdr_inline_decode(xdr, 4);
 427         if (unlikely(p == NULL))
 428                 return -EIO;
 429         entries = be32_to_cpup(p);
 430         dprintk("NFS: received %u auth flavors\n", entries);
 431         if (entries > NFS_MAX_SECFLAVORS)
 432                 entries = NFS_MAX_SECFLAVORS;
 433
 434         p = xdr_inline_decode(xdr, 4 * entries);
 435         if (unlikely(p == NULL))
 436                 return -EIO;
 437
 438         if (entries > *count)
 439                 entries = *count;
 440
 441         for (i = 0; i < entries; i++) {
 442                 flavors[i] = be32_to_cpup(p++);
 443                 dprintk("NFS:   auth flavor[%u]: %d\n", i, flavors[i]);
 444         }
 445         *count = i;
 446
 447         return 0;
 448 }
 449
 450 static int mnt_xdr_dec_mountres3(struct rpc_rqst *req,
 451                                  struct xdr_stream *xdr,
 452                                  struct mountres *res)
 453 {
 454         int status;
 455
 456         status = decode_fhs_status(xdr, res);
 457         if (unlikely(status != 0 || res->errno != 0))
 458                 return status;
 459         status = decode_fhandle3(xdr, res);
 460         if (unlikely(status != 0)) {
 461                 res->errno = -EBADHANDLE;
 462                 return 0;
 463         }
 464         return decode_auth_flavors(xdr, res);
 465 }
 466
 467 static struct rpc_procinfo mnt_procedures[] = {
 468         [MOUNTPROC_MNT] = {
 469                 .p_proc         = MOUNTPROC_MNT,
 470                 .p_encode       = (kxdreproc_t)mnt_xdr_enc_dirpath,
 471                 .p_decode       = (kxdrdproc_t)mnt_xdr_dec_mountres,
 472                 .p_arglen       = MNT_enc_dirpath_sz,
 473                 .p_replen       = MNT_dec_mountres_sz,
 474                 .p_statidx      = MOUNTPROC_MNT,
 475                 .p_name         = "MOUNT",
 476         },
 477         [MOUNTPROC_UMNT] = {
 478                 .p_proc         = MOUNTPROC_UMNT,
 479                 .p_encode       = (kxdreproc_t)mnt_xdr_enc_dirpath,
 480                 .p_arglen       = MNT_enc_dirpath_sz,
 481                 .p_statidx      = MOUNTPROC_UMNT,
 482                 .p_name         = "UMOUNT",
 483         },
 484 };
 485
 486 static struct rpc_procinfo mnt3_procedures[] = {
 487         [MOUNTPROC3_MNT] = {
 488                 .p_proc         = MOUNTPROC3_MNT,
 489                 .p_encode       = (kxdreproc_t)mnt_xdr_enc_dirpath,
 490                 .p_decode       = (kxdrdproc_t)mnt_xdr_dec_mountres3,
 491                 .p_arglen       = MNT_enc_dirpath_sz,
 492                 .p_replen       = MNT_dec_mountres3_sz,
 493                 .p_statidx      = MOUNTPROC3_MNT,
 494                 .p_name         = "MOUNT",
 495         },
 496         [MOUNTPROC3_UMNT] = {
 497                 .p_proc         = MOUNTPROC3_UMNT,
 498                 .p_encode       = (kxdreproc_t)mnt_xdr_enc_dirpath,
 499                 .p_arglen       = MNT_enc_dirpath_sz,
 500                 .p_statidx      = MOUNTPROC3_UMNT,
 501                 .p_name         = "UMOUNT",
 502         },
 503 };
 504
 505
 506 static const struct rpc_version mnt_version1 = {
 507         .number         = 1,
 508         .nrprocs        = ARRAY_SIZE(mnt_procedures),
 509         .procs          = mnt_procedures,
 510 };
 511
 512 static const struct rpc_version mnt_version3 = {
 513         .number         = 3,
 514         .nrprocs        = ARRAY_SIZE(mnt3_procedures),
 515         .procs          = mnt3_procedures,
 516 };
 517
 518 static const struct rpc_version *mnt_version[] = {
 519         NULL,
 520         &mnt_version1,
 521         NULL,
 522         &mnt_version3,
 523 };
 524
 525 static struct rpc_stat mnt_stats;
 526
 527 static const struct rpc_program mnt_program = {
 528         .name           = "mount",
 529         .number         = NFS_MNT_PROGRAM,
 530         .nrvers         = ARRAY_SIZE(mnt_version),
 531         .version        = mnt_version,
 532         .stats          = &mnt_stats,
 533 };