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 NFS_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 const 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            = info->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 (strlen(info->dirpath) > MNTPATHLEN)
 173                 return -ENAMETOOLONG;
 174
 175         if (info->noresvport)
 176                 args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
 177
 178         mnt_clnt = rpc_create(&args);
 179         if (IS_ERR(mnt_clnt))
 180                 goto out_clnt_err;
 181
 182         if (info->version == NFS_MNT3_VERSION)
 183                 msg.rpc_proc = &mnt_clnt->cl_procinfo[MOUNTPROC3_MNT];
 184         else
 185                 msg.rpc_proc = &mnt_clnt->cl_procinfo[MOUNTPROC_MNT];
 186
 187         status = rpc_call_sync(mnt_clnt, &msg, RPC_TASK_SOFT|RPC_TASK_TIMEOUT);
 188         rpc_shutdown_client(mnt_clnt);
 189
 190         if (status < 0)
 191                 goto out_call_err;
 192         if (result.errno != 0)
 193                 goto out_mnt_err;
 194
 195         dprintk("NFS: MNT request succeeded\n");
 196         status = 0;
 197
 198 out:
 199         return status;
 200
 201 out_clnt_err:
 202         status = PTR_ERR(mnt_clnt);
 203         dprintk("NFS: failed to create MNT RPC client, status=%d\n", status);
 204         goto out;
 205
 206 out_call_err:
 207         dprintk("NFS: MNT request failed, status=%d\n", status);
 208         goto out;
 209
 210 out_mnt_err:
 211         dprintk("NFS: MNT server returned result %d\n", result.errno);
 212         status = result.errno;
 213         goto out;
 214 }
 215
 216 /**
 217  * nfs_umount - Notify a server that we have unmounted this export
 218  * @info: pointer to umount request arguments
 219  *
 220  * MOUNTPROC_UMNT is advisory, so we set a short timeout, and always
 221  * use UDP.
 222  */
 223 void nfs_umount(const struct nfs_mount_request *info)
 224 {
 225         static const struct rpc_timeout nfs_umnt_timeout = {
 226                 .to_initval = 1 * HZ,
 227                 .to_maxval = 3 * HZ,
 228                 .to_retries = 2,
 229         };
 230         struct rpc_create_args args = {
 231                 .net            = info->net,
 232                 .protocol       = IPPROTO_UDP,
 233                 .address        = info->sap,
 234                 .addrsize       = info->salen,
 235                 .timeout        = &nfs_umnt_timeout,
 236                 .servername     = info->hostname,
 237                 .program        = &mnt_program,
 238                 .version        = info->version,
 239                 .authflavor     = RPC_AUTH_UNIX,
 240                 .flags          = RPC_CLNT_CREATE_NOPING,
 241         };
 242         struct rpc_message msg  = {
 243                 .rpc_argp       = info->dirpath,
 244         };
 245         struct rpc_clnt *clnt;
 246         int status;
 247
 248         if (strlen(info->dirpath) > MNTPATHLEN)
 249                 return;
 250
 251         if (info->noresvport)
 252                 args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
 253
 254         clnt = rpc_create(&args);
 255         if (IS_ERR(clnt))
 256                 goto out_clnt_err;
 257
 258         dprintk("NFS: sending UMNT request for %s:%s\n",
 259                 (info->hostname ? info->hostname : "server"), info->dirpath);
 260
 261         if (info->version == NFS_MNT3_VERSION)
 262                 msg.rpc_proc = &clnt->cl_procinfo[MOUNTPROC3_UMNT];
 263         else
 264                 msg.rpc_proc = &clnt->cl_procinfo[MOUNTPROC_UMNT];
 265
 266         status = rpc_call_sync(clnt, &msg, 0);
 267         rpc_shutdown_client(clnt);
 268
 269         if (unlikely(status < 0))
 270                 goto out_call_err;
 271
 272         return;
 273
 274 out_clnt_err:
 275         dprintk("NFS: failed to create UMNT RPC client, status=%ld\n",
 276                         PTR_ERR(clnt));
 277         return;
 278
 279 out_call_err:
 280         dprintk("NFS: UMNT request failed, status=%d\n", status);
 281 }
 282
 283 /*
 284  * XDR encode/decode functions for MOUNT
 285  */
 286
 287 static void encode_mntdirpath(struct xdr_stream *xdr, const char *pathname)
 288 {
 289         const u32 pathname_len = strlen(pathname);
 290         __be32 *p;
 291
 292         p = xdr_reserve_space(xdr, 4 + pathname_len);
 293         xdr_encode_opaque(p, pathname, pathname_len);
 294 }
 295
 296 static void mnt_xdr_enc_dirpath(struct rpc_rqst *req, struct xdr_stream *xdr,
 297                                 const char *dirpath)
 298 {
 299         encode_mntdirpath(xdr, dirpath);
 300 }
 301
 302 /*
 303  * RFC 1094: "A non-zero status indicates some sort of error.  In this
 304  * case, the status is a UNIX error number."  This can be problematic
 305  * if the server and client use different errno values for the same
 306  * error.
 307  *
 308  * However, the OpenGroup XNFS spec provides a simple mapping that is
 309  * independent of local errno values on the server and the client.
 310  */
 311 static int decode_status(struct xdr_stream *xdr, struct mountres *res)
 312 {
 313         unsigned int i;
 314         u32 status;
 315         __be32 *p;
 316
 317         p = xdr_inline_decode(xdr, 4);
 318         if (unlikely(p == NULL))
 319                 return -EIO;
 320         status = be32_to_cpup(p);
 321
 322         for (i = 0; i < ARRAY_SIZE(mnt_errtbl); i++) {
 323                 if (mnt_errtbl[i].status == status) {
 324                         res->errno = mnt_errtbl[i].errno;
 325                         return 0;
 326                 }
 327         }
 328
 329         dprintk("NFS: unrecognized MNT status code: %u\n", status);
 330         res->errno = -EACCES;
 331         return 0;
 332 }
 333
 334 static int decode_fhandle(struct xdr_stream *xdr, struct mountres *res)
 335 {
 336         struct nfs_fh *fh = res->fh;
 337         __be32 *p;
 338
 339         p = xdr_inline_decode(xdr, NFS2_FHSIZE);
 340         if (unlikely(p == NULL))
 341                 return -EIO;
 342
 343         fh->size = NFS2_FHSIZE;
 344         memcpy(fh->data, p, NFS2_FHSIZE);
 345         return 0;
 346 }
 347
 348 static int mnt_xdr_dec_mountres(struct rpc_rqst *req,
 349                                 struct xdr_stream *xdr,
 350                                 struct mountres *res)
 351 {
 352         int status;
 353
 354         status = decode_status(xdr, res);
 355         if (unlikely(status != 0 || res->errno != 0))
 356                 return status;
 357         return decode_fhandle(xdr, res);
 358 }
 359
 360 static int decode_fhs_status(struct xdr_stream *xdr, struct mountres *res)
 361 {
 362         unsigned int i;
 363         u32 status;
 364         __be32 *p;
 365
 366         p = xdr_inline_decode(xdr, 4);
 367         if (unlikely(p == NULL))
 368                 return -EIO;
 369         status = be32_to_cpup(p);
 370
 371         for (i = 0; i < ARRAY_SIZE(mnt3_errtbl); i++) {
 372                 if (mnt3_errtbl[i].status == status) {
 373                         res->errno = mnt3_errtbl[i].errno;
 374                         return 0;
 375                 }
 376         }
 377
 378         dprintk("NFS: unrecognized MNT3 status code: %u\n", status);
 379         res->errno = -EACCES;
 380         return 0;
 381 }
 382
 383 static int decode_fhandle3(struct xdr_stream *xdr, struct mountres *res)
 384 {
 385         struct nfs_fh *fh = res->fh;
 386         u32 size;
 387         __be32 *p;
 388
 389         p = xdr_inline_decode(xdr, 4);
 390         if (unlikely(p == NULL))
 391                 return -EIO;
 392
 393         size = be32_to_cpup(p);
 394         if (size > NFS3_FHSIZE || size == 0)
 395                 return -EIO;
 396
 397         p = xdr_inline_decode(xdr, size);
 398         if (unlikely(p == NULL))
 399                 return -EIO;
 400
 401         fh->size = size;
 402         memcpy(fh->data, p, size);
 403         return 0;
 404 }
 405
 406 static int decode_auth_flavors(struct xdr_stream *xdr, struct mountres *res)
 407 {
 408         rpc_authflavor_t *flavors = res->auth_flavors;
 409         unsigned int *count = res->auth_count;
 410         u32 entries, i;
 411         __be32 *p;
 412
 413         if (*count == 0)
 414                 return 0;
 415
 416         p = xdr_inline_decode(xdr, 4);
 417         if (unlikely(p == NULL))
 418                 return -EIO;
 419         entries = be32_to_cpup(p);
 420         dprintk("NFS: received %u auth flavors\n", entries);
 421         if (entries > NFS_MAX_SECFLAVORS)
 422                 entries = NFS_MAX_SECFLAVORS;
 423
 424         p = xdr_inline_decode(xdr, 4 * entries);
 425         if (unlikely(p == NULL))
 426                 return -EIO;
 427
 428         if (entries > *count)
 429                 entries = *count;
 430
 431         for (i = 0; i < entries; i++) {
 432                 flavors[i] = be32_to_cpup(p++);
 433                 dprintk("NFS:   auth flavor[%u]: %d\n", i, flavors[i]);
 434         }
 435         *count = i;
 436
 437         return 0;
 438 }
 439
 440 static int mnt_xdr_dec_mountres3(struct rpc_rqst *req,
 441                                  struct xdr_stream *xdr,
 442                                  struct mountres *res)
 443 {
 444         int status;
 445
 446         status = decode_fhs_status(xdr, res);
 447         if (unlikely(status != 0 || res->errno != 0))
 448                 return status;
 449         status = decode_fhandle3(xdr, res);
 450         if (unlikely(status != 0)) {
 451                 res->errno = -EBADHANDLE;
 452                 return 0;
 453         }
 454         return decode_auth_flavors(xdr, res);
 455 }
 456
 457 static struct rpc_procinfo mnt_procedures[] = {
 458         [MOUNTPROC_MNT] = {
 459                 .p_proc         = MOUNTPROC_MNT,
 460                 .p_encode       = (kxdreproc_t)mnt_xdr_enc_dirpath,
 461                 .p_decode       = (kxdrdproc_t)mnt_xdr_dec_mountres,
 462                 .p_arglen       = MNT_enc_dirpath_sz,
 463                 .p_replen       = MNT_dec_mountres_sz,
 464                 .p_statidx      = MOUNTPROC_MNT,
 465                 .p_name         = "MOUNT",
 466         },
 467         [MOUNTPROC_UMNT] = {
 468                 .p_proc         = MOUNTPROC_UMNT,
 469                 .p_encode       = (kxdreproc_t)mnt_xdr_enc_dirpath,
 470                 .p_arglen       = MNT_enc_dirpath_sz,
 471                 .p_statidx      = MOUNTPROC_UMNT,
 472                 .p_name         = "UMOUNT",
 473         },
 474 };
 475
 476 static struct rpc_procinfo mnt3_procedures[] = {
 477         [MOUNTPROC3_MNT] = {
 478                 .p_proc         = MOUNTPROC3_MNT,
 479                 .p_encode       = (kxdreproc_t)mnt_xdr_enc_dirpath,
 480                 .p_decode       = (kxdrdproc_t)mnt_xdr_dec_mountres3,
 481                 .p_arglen       = MNT_enc_dirpath_sz,
 482                 .p_replen       = MNT_dec_mountres3_sz,
 483                 .p_statidx      = MOUNTPROC3_MNT,
 484                 .p_name         = "MOUNT",
 485         },
 486         [MOUNTPROC3_UMNT] = {
 487                 .p_proc         = MOUNTPROC3_UMNT,
 488                 .p_encode       = (kxdreproc_t)mnt_xdr_enc_dirpath,
 489                 .p_arglen       = MNT_enc_dirpath_sz,
 490                 .p_statidx      = MOUNTPROC3_UMNT,
 491                 .p_name         = "UMOUNT",
 492         },
 493 };
 494
 495
 496 static const struct rpc_version mnt_version1 = {
 497         .number         = 1,
 498         .nrprocs        = ARRAY_SIZE(mnt_procedures),
 499         .procs          = mnt_procedures,
 500 };
 501
 502 static const struct rpc_version mnt_version3 = {
 503         .number         = 3,
 504         .nrprocs        = ARRAY_SIZE(mnt3_procedures),
 505         .procs          = mnt3_procedures,
 506 };
 507
 508 static const struct rpc_version *mnt_version[] = {
 509         NULL,
 510         &mnt_version1,
 511         NULL,
 512         &mnt_version3,
 513 };
 514
 515 static struct rpc_stat mnt_stats;
 516
 517 static const struct rpc_program mnt_program = {
 518         .name           = "mount",
 519         .number         = NFS_MNT_PROGRAM,
 520         .nrvers         = ARRAY_SIZE(mnt_version),
 521         .version        = mnt_version,
 522         .stats          = &mnt_stats,
 523 };