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