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 int encode_mntdirpath(struct xdr_stream *xdr, const char *pathname)
 284 {
 285         const u32 pathname_len = strlen(pathname);
 286         __be32 *p;
 287
 288         if (unlikely(pathname_len > MNTPATHLEN))
 289                 return -EIO;
 290
 291         p = xdr_reserve_space(xdr, sizeof(u32) + pathname_len);
 292         if (unlikely(p == NULL))
 293                 return -EIO;
 294         xdr_encode_opaque(p, pathname, pathname_len);
 295
 296         return 0;
 297 }
 298
 299 static int mnt_enc_dirpath(struct rpc_rqst *req, __be32 *p,
 300                            const char *dirpath)
 301 {
 302         struct xdr_stream xdr;
 303
 304         xdr_init_encode(&xdr, &req->rq_snd_buf, p);
 305         return encode_mntdirpath(&xdr, dirpath);
 306 }
 307
 308 /*
 309  * RFC 1094: "A non-zero status indicates some sort of error.  In this
 310  * case, the status is a UNIX error number."  This can be problematic
 311  * if the server and client use different errno values for the same
 312  * error.
 313  *
 314  * However, the OpenGroup XNFS spec provides a simple mapping that is
 315  * independent of local errno values on the server and the client.
 316  */
 317 static int decode_status(struct xdr_stream *xdr, struct mountres *res)
 318 {
 319         unsigned int i;
 320         u32 status;
 321         __be32 *p;
 322
 323         p = xdr_inline_decode(xdr, sizeof(status));
 324         if (unlikely(p == NULL))
 325                 return -EIO;
 326         status = ntohl(*p);
 327
 328         for (i = 0; i < ARRAY_SIZE(mnt_errtbl); i++) {
 329                 if (mnt_errtbl[i].status == status) {
 330                         res->errno = mnt_errtbl[i].errno;
 331                         return 0;
 332                 }
 333         }
 334
 335         dprintk("NFS: unrecognized MNT status code: %u\n", status);
 336         res->errno = -EACCES;
 337         return 0;
 338 }
 339
 340 static int decode_fhandle(struct xdr_stream *xdr, struct mountres *res)
 341 {
 342         struct nfs_fh *fh = res->fh;
 343         __be32 *p;
 344
 345         p = xdr_inline_decode(xdr, NFS2_FHSIZE);
 346         if (unlikely(p == NULL))
 347                 return -EIO;
 348
 349         fh->size = NFS2_FHSIZE;
 350         memcpy(fh->data, p, NFS2_FHSIZE);
 351         return 0;
 352 }
 353
 354 static int mnt_dec_mountres(struct rpc_rqst *req, __be32 *p,
 355                             struct mountres *res)
 356 {
 357         struct xdr_stream xdr;
 358         int status;
 359
 360         xdr_init_decode(&xdr, &req->rq_rcv_buf, p);
 361
 362         status = decode_status(&xdr, res);
 363         if (unlikely(status != 0 || res->errno != 0))
 364                 return status;
 365         return decode_fhandle(&xdr, res);
 366 }
 367
 368 static int decode_fhs_status(struct xdr_stream *xdr, struct mountres *res)
 369 {
 370         unsigned int i;
 371         u32 status;
 372         __be32 *p;
 373
 374         p = xdr_inline_decode(xdr, sizeof(status));
 375         if (unlikely(p == NULL))
 376                 return -EIO;
 377         status = ntohl(*p);
 378
 379         for (i = 0; i < ARRAY_SIZE(mnt3_errtbl); i++) {
 380                 if (mnt3_errtbl[i].status == status) {
 381                         res->errno = mnt3_errtbl[i].errno;
 382                         return 0;
 383                 }
 384         }
 385
 386         dprintk("NFS: unrecognized MNT3 status code: %u\n", status);
 387         res->errno = -EACCES;
 388         return 0;
 389 }
 390
 391 static int decode_fhandle3(struct xdr_stream *xdr, struct mountres *res)
 392 {
 393         struct nfs_fh *fh = res->fh;
 394         u32 size;
 395         __be32 *p;
 396
 397         p = xdr_inline_decode(xdr, sizeof(size));
 398         if (unlikely(p == NULL))
 399                 return -EIO;
 400
 401         size = ntohl(*p++);
 402         if (size > NFS3_FHSIZE || size == 0)
 403                 return -EIO;
 404
 405         p = xdr_inline_decode(xdr, size);
 406         if (unlikely(p == NULL))
 407                 return -EIO;
 408
 409         fh->size = size;
 410         memcpy(fh->data, p, size);
 411         return 0;
 412 }
 413
 414 static int decode_auth_flavors(struct xdr_stream *xdr, struct mountres *res)
 415 {
 416         rpc_authflavor_t *flavors = res->auth_flavors;
 417         unsigned int *count = res->auth_count;
 418         u32 entries, i;
 419         __be32 *p;
 420
 421         if (*count == 0)
 422                 return 0;
 423
 424         p = xdr_inline_decode(xdr, sizeof(entries));
 425         if (unlikely(p == NULL))
 426                 return -EIO;
 427         entries = ntohl(*p);
 428         dprintk("NFS: received %u auth flavors\n", entries);
 429         if (entries > NFS_MAX_SECFLAVORS)
 430                 entries = NFS_MAX_SECFLAVORS;
 431
 432         p = xdr_inline_decode(xdr, sizeof(u32) * entries);
 433         if (unlikely(p == NULL))
 434                 return -EIO;
 435
 436         if (entries > *count)
 437                 entries = *count;
 438
 439         for (i = 0; i < entries; i++) {
 440                 flavors[i] = ntohl(*p++);
 441                 dprintk("NFS:   auth flavor[%u]: %d\n", i, flavors[i]);
 442         }
 443         *count = i;
 444
 445         return 0;
 446 }
 447
 448 static int mnt_dec_mountres3(struct rpc_rqst *req, __be32 *p,
 449                              struct mountres *res)
 450 {
 451         struct xdr_stream xdr;
 452         int status;
 453
 454         xdr_init_decode(&xdr, &req->rq_rcv_buf, p);
 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       = (kxdrproc_t)mnt_enc_dirpath,
 471                 .p_decode       = (kxdrproc_t)mnt_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       = (kxdrproc_t)mnt_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       = (kxdrproc_t)mnt_enc_dirpath,
 490                 .p_decode       = (kxdrproc_t)mnt_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       = (kxdrproc_t)mnt_enc_dirpath,
 499                 .p_arglen       = MNT_enc_dirpath_sz,
 500                 .p_statidx      = MOUNTPROC3_UMNT,
 501                 .p_name         = "UMOUNT",
 502         },
 503 };
 504
 505
 506 static struct rpc_version mnt_version1 = {
 507         .number         = 1,
 508         .nrprocs        = 2,
 509         .procs          = mnt_procedures,
 510 };
 511
 512 static struct rpc_version mnt_version3 = {
 513         .number         = 3,
 514         .nrprocs        = 2,
 515         .procs          = mnt3_procedures,
 516 };
 517
 518 static 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 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 };