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 mountres result;
 240         struct rpc_message msg  = {
 241                 .rpc_argp       = info->dirpath,
 242                 .rpc_resp       = &result,
 243         };
 244         struct rpc_clnt *clnt;
 245         int status;
 246
 247         if (info->noresvport)
 248                 args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
 249
 250         clnt = rpc_create(&args);
 251         if (unlikely(IS_ERR(clnt)))
 252                 goto out_clnt_err;
 253
 254         dprintk("NFS: sending UMNT request for %s:%s\n",
 255                 (info->hostname ? info->hostname : "server"), info->dirpath);
 256
 257         if (info->version == NFS_MNT3_VERSION)
 258                 msg.rpc_proc = &clnt->cl_procinfo[MOUNTPROC3_UMNT];
 259         else
 260                 msg.rpc_proc = &clnt->cl_procinfo[MOUNTPROC_UMNT];
 261
 262         status = rpc_call_sync(clnt, &msg, 0);
 263         rpc_shutdown_client(clnt);
 264
 265         if (unlikely(status < 0))
 266                 goto out_call_err;
 267
 268         return;
 269
 270 out_clnt_err:
 271         dprintk("NFS: failed to create UMNT RPC client, status=%ld\n",
 272                         PTR_ERR(clnt));
 273         return;
 274
 275 out_call_err:
 276         dprintk("NFS: UMNT request failed, status=%d\n", status);
 277 }
 278
 279 /*
 280  * XDR encode/decode functions for MOUNT
 281  */
 282
 283 static void encode_mntdirpath(struct xdr_stream *xdr, const char *pathname)
 284 {
 285         const u32 pathname_len = strlen(pathname);
 286         __be32 *p;
 287
 288         BUG_ON(pathname_len > MNTPATHLEN);
 289         p = xdr_reserve_space(xdr, 4 + pathname_len);
 290         xdr_encode_opaque(p, pathname, pathname_len);
 291 }
 292
 293 static int mnt_enc_dirpath(struct rpc_rqst *req, __be32 *p,
 294                            const char *dirpath)
 295 {
 296         struct xdr_stream xdr;
 297
 298         xdr_init_encode(&xdr, &req->rq_snd_buf, p);
 299         encode_mntdirpath(&xdr, dirpath);
 300         return 0;
 301 }
 302
 303 /*
 304  * RFC 1094: "A non-zero status indicates some sort of error.  In this
 305  * case, the status is a UNIX error number."  This can be problematic
 306  * if the server and client use different errno values for the same
 307  * error.
 308  *
 309  * However, the OpenGroup XNFS spec provides a simple mapping that is
 310  * independent of local errno values on the server and the client.
 311  */
 312 static int decode_status(struct xdr_stream *xdr, struct mountres *res)
 313 {
 314         unsigned int i;
 315         u32 status;
 316         __be32 *p;
 317
 318         p = xdr_inline_decode(xdr, 4);
 319         if (unlikely(p == NULL))
 320                 return -EIO;
 321         status = be32_to_cpup(p);
 322
 323         for (i = 0; i < ARRAY_SIZE(mnt_errtbl); i++) {
 324                 if (mnt_errtbl[i].status == status) {
 325                         res->errno = mnt_errtbl[i].errno;
 326                         return 0;
 327                 }
 328         }
 329
 330         dprintk("NFS: unrecognized MNT status code: %u\n", status);
 331         res->errno = -EACCES;
 332         return 0;
 333 }
 334
 335 static int decode_fhandle(struct xdr_stream *xdr, struct mountres *res)
 336 {
 337         struct nfs_fh *fh = res->fh;
 338         __be32 *p;
 339
 340         p = xdr_inline_decode(xdr, NFS2_FHSIZE);
 341         if (unlikely(p == NULL))
 342                 return -EIO;
 343
 344         fh->size = NFS2_FHSIZE;
 345         memcpy(fh->data, p, NFS2_FHSIZE);
 346         return 0;
 347 }
 348
 349 static int mnt_dec_mountres(struct rpc_rqst *req, __be32 *p,
 350                             struct mountres *res)
 351 {
 352         struct xdr_stream xdr;
 353         int status;
 354
 355         xdr_init_decode(&xdr, &req->rq_rcv_buf, p);
 356
 357         status = decode_status(&xdr, res);
 358         if (unlikely(status != 0 || res->errno != 0))
 359                 return status;
 360         return decode_fhandle(&xdr, res);
 361 }
 362
 363 static int decode_fhs_status(struct xdr_stream *xdr, struct mountres *res)
 364 {
 365         unsigned int i;
 366         u32 status;
 367         __be32 *p;
 368
 369         p = xdr_inline_decode(xdr, 4);
 370         if (unlikely(p == NULL))
 371                 return -EIO;
 372         status = be32_to_cpup(p);
 373
 374         for (i = 0; i < ARRAY_SIZE(mnt3_errtbl); i++) {
 375                 if (mnt3_errtbl[i].status == status) {
 376                         res->errno = mnt3_errtbl[i].errno;
 377                         return 0;
 378                 }
 379         }
 380
 381         dprintk("NFS: unrecognized MNT3 status code: %u\n", status);
 382         res->errno = -EACCES;
 383         return 0;
 384 }
 385
 386 static int decode_fhandle3(struct xdr_stream *xdr, struct mountres *res)
 387 {
 388         struct nfs_fh *fh = res->fh;
 389         u32 size;
 390         __be32 *p;
 391
 392         p = xdr_inline_decode(xdr, 4);
 393         if (unlikely(p == NULL))
 394                 return -EIO;
 395
 396         size = be32_to_cpup(p);
 397         if (size > NFS3_FHSIZE || size == 0)
 398                 return -EIO;
 399
 400         p = xdr_inline_decode(xdr, size);
 401         if (unlikely(p == NULL))
 402                 return -EIO;
 403
 404         fh->size = size;
 405         memcpy(fh->data, p, size);
 406         return 0;
 407 }
 408
 409 static int decode_auth_flavors(struct xdr_stream *xdr, struct mountres *res)
 410 {
 411         rpc_authflavor_t *flavors = res->auth_flavors;
 412         unsigned int *count = res->auth_count;
 413         u32 entries, i;
 414         __be32 *p;
 415
 416         if (*count == 0)
 417                 return 0;
 418
 419         p = xdr_inline_decode(xdr, 4);
 420         if (unlikely(p == NULL))
 421                 return -EIO;
 422         entries = be32_to_cpup(p);
 423         dprintk("NFS: received %u auth flavors\n", entries);
 424         if (entries > NFS_MAX_SECFLAVORS)
 425                 entries = NFS_MAX_SECFLAVORS;
 426
 427         p = xdr_inline_decode(xdr, 4 * entries);
 428         if (unlikely(p == NULL))
 429                 return -EIO;
 430
 431         if (entries > *count)
 432                 entries = *count;
 433
 434         for (i = 0; i < entries; i++) {
 435                 flavors[i] = be32_to_cpup(p++);
 436                 dprintk("NFS:   auth flavor[%u]: %d\n", i, flavors[i]);
 437         }
 438         *count = i;
 439
 440         return 0;
 441 }
 442
 443 static int mnt_dec_mountres3(struct rpc_rqst *req, __be32 *p,
 444                              struct mountres *res)
 445 {
 446         struct xdr_stream xdr;
 447         int status;
 448
 449         xdr_init_decode(&xdr, &req->rq_rcv_buf, p);
 450
 451         status = decode_fhs_status(&xdr, res);
 452         if (unlikely(status != 0 || res->errno != 0))
 453                 return status;
 454         status = decode_fhandle3(&xdr, res);
 455         if (unlikely(status != 0)) {
 456                 res->errno = -EBADHANDLE;
 457                 return 0;
 458         }
 459         return decode_auth_flavors(&xdr, res);
 460 }
 461
 462 static struct rpc_procinfo mnt_procedures[] = {
 463         [MOUNTPROC_MNT] = {
 464                 .p_proc         = MOUNTPROC_MNT,
 465                 .p_encode       = (kxdrproc_t)mnt_enc_dirpath,
 466                 .p_decode       = (kxdrproc_t)mnt_dec_mountres,
 467                 .p_arglen       = MNT_enc_dirpath_sz,
 468                 .p_replen       = MNT_dec_mountres_sz,
 469                 .p_statidx      = MOUNTPROC_MNT,
 470                 .p_name         = "MOUNT",
 471         },
 472         [MOUNTPROC_UMNT] = {
 473                 .p_proc         = MOUNTPROC_UMNT,
 474                 .p_encode       = (kxdrproc_t)mnt_enc_dirpath,
 475                 .p_arglen       = MNT_enc_dirpath_sz,
 476                 .p_statidx      = MOUNTPROC_UMNT,
 477                 .p_name         = "UMOUNT",
 478         },
 479 };
 480
 481 static struct rpc_procinfo mnt3_procedures[] = {
 482         [MOUNTPROC3_MNT] = {
 483                 .p_proc         = MOUNTPROC3_MNT,
 484                 .p_encode       = (kxdrproc_t)mnt_enc_dirpath,
 485                 .p_decode       = (kxdrproc_t)mnt_dec_mountres3,
 486                 .p_arglen       = MNT_enc_dirpath_sz,
 487                 .p_replen       = MNT_dec_mountres3_sz,
 488                 .p_statidx      = MOUNTPROC3_MNT,
 489                 .p_name         = "MOUNT",
 490         },
 491         [MOUNTPROC3_UMNT] = {
 492                 .p_proc         = MOUNTPROC3_UMNT,
 493                 .p_encode       = (kxdrproc_t)mnt_enc_dirpath,
 494                 .p_arglen       = MNT_enc_dirpath_sz,
 495                 .p_statidx      = MOUNTPROC3_UMNT,
 496                 .p_name         = "UMOUNT",
 497         },
 498 };
 499
 500
 501 static struct rpc_version mnt_version1 = {
 502         .number         = 1,
 503         .nrprocs        = ARRAY_SIZE(mnt_procedures),
 504         .procs          = mnt_procedures,
 505 };
 506
 507 static struct rpc_version mnt_version3 = {
 508         .number         = 3,
 509         .nrprocs        = ARRAY_SIZE(mnt3_procedures),
 510         .procs          = mnt3_procedures,
 511 };
 512
 513 static struct rpc_version *mnt_version[] = {
 514         NULL,
 515         &mnt_version1,
 516         NULL,
 517         &mnt_version3,
 518 };
 519
 520 static struct rpc_stat mnt_stats;
 521
 522 static struct rpc_program mnt_program = {
 523         .name           = "mount",
 524         .number         = NFS_MNT_PROGRAM,
 525         .nrvers         = ARRAY_SIZE(mnt_version),
 526         .version        = mnt_version,
 527         .stats          = &mnt_stats,
 528 };