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 = -ESERVERFAULT, },
 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                 .protocol       = info->protocol,
 157                 .address        = info->sap,
 158                 .addrsize       = info->salen,
 159                 .servername     = info->hostname,
 160                 .program        = &mnt_program,
 161                 .version        = info->version,
 162                 .authflavor     = RPC_AUTH_UNIX,
 163         };
 164         struct rpc_clnt         *mnt_clnt;
 165         int                     status;
 166
 167         dprintk("NFS: sending MNT request for %s:%s\n",
 168                 (info->hostname ? info->hostname : "server"),
 169                         info->dirpath);
 170
 171         if (info->noresvport)
 172                 args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
 173
 174         mnt_clnt = rpc_create(&args);
 175         if (IS_ERR(mnt_clnt))
 176                 goto out_clnt_err;
 177
 178         if (info->version == NFS_MNT3_VERSION)
 179                 msg.rpc_proc = &mnt_clnt->cl_procinfo[MOUNTPROC3_MNT];
 180         else
 181                 msg.rpc_proc = &mnt_clnt->cl_procinfo[MOUNTPROC_MNT];
 182
 183         status = rpc_call_sync(mnt_clnt, &msg, 0);
 184         rpc_shutdown_client(mnt_clnt);
 185
 186         if (status < 0)
 187                 goto out_call_err;
 188         if (result.errno != 0)
 189                 goto out_mnt_err;
 190
 191         dprintk("NFS: MNT request succeeded\n");
 192         status = 0;
 193
 194 out:
 195         return status;
 196
 197 out_clnt_err:
 198         status = PTR_ERR(mnt_clnt);
 199         dprintk("NFS: failed to create MNT RPC client, status=%d\n", status);
 200         goto out;
 201
 202 out_call_err:
 203         dprintk("NFS: MNT request failed, status=%d\n", status);
 204         goto out;
 205
 206 out_mnt_err:
 207         dprintk("NFS: MNT server returned result %d\n", result.errno);
 208         status = result.errno;
 209         goto out;
 210 }
 211
 212 /**
 213  * nfs_umount - Notify a server that we have unmounted this export
 214  * @info: pointer to umount request arguments
 215  *
 216  * MOUNTPROC_UMNT is advisory, so we set a short timeout, and always
 217  * use UDP.
 218  */
 219 void nfs_umount(const struct nfs_mount_request *info)
 220 {
 221         static const struct rpc_timeout nfs_umnt_timeout = {
 222                 .to_initval = 1 * HZ,
 223                 .to_maxval = 3 * HZ,
 224                 .to_retries = 2,
 225         };
 226         struct rpc_create_args args = {
 227                 .protocol       = IPPROTO_UDP,
 228                 .address        = info->sap,
 229                 .addrsize       = info->salen,
 230                 .timeout        = &nfs_umnt_timeout,
 231                 .servername     = info->hostname,
 232                 .program        = &mnt_program,
 233                 .version        = info->version,
 234                 .authflavor     = RPC_AUTH_UNIX,
 235                 .flags          = RPC_CLNT_CREATE_NOPING,
 236         };
 237         struct mountres result;
 238         struct rpc_message msg  = {
 239                 .rpc_argp       = info->dirpath,
 240                 .rpc_resp       = &result,
 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 (unlikely(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 int encode_mntdirpath(struct xdr_stream *xdr, const char *pathname)
 282 {
 283         const u32 pathname_len = strlen(pathname);
 284         __be32 *p;
 285
 286         if (unlikely(pathname_len > MNTPATHLEN))
 287                 return -EIO;
 288
 289         p = xdr_reserve_space(xdr, sizeof(u32) + pathname_len);
 290         if (unlikely(p == NULL))
 291                 return -EIO;
 292         xdr_encode_opaque(p, pathname, pathname_len);
 293
 294         return 0;
 295 }
 296
 297 static int mnt_enc_dirpath(struct rpc_rqst *req, __be32 *p,
 298                            const char *dirpath)
 299 {
 300         struct xdr_stream xdr;
 301
 302         xdr_init_encode(&xdr, &req->rq_snd_buf, p);
 303         return encode_mntdirpath(&xdr, dirpath);
 304 }
 305
 306 /*
 307  * RFC 1094: "A non-zero status indicates some sort of error.  In this
 308  * case, the status is a UNIX error number."  This can be problematic
 309  * if the server and client use different errno values for the same
 310  * error.
 311  *
 312  * However, the OpenGroup XNFS spec provides a simple mapping that is
 313  * independent of local errno values on the server and the client.
 314  */
 315 static int decode_status(struct xdr_stream *xdr, struct mountres *res)
 316 {
 317         unsigned int i;
 318         u32 status;
 319         __be32 *p;
 320
 321         p = xdr_inline_decode(xdr, sizeof(status));
 322         if (unlikely(p == NULL))
 323                 return -EIO;
 324         status = ntohl(*p);
 325
 326         for (i = 0; i < ARRAY_SIZE(mnt_errtbl); i++) {
 327                 if (mnt_errtbl[i].status == status) {
 328                         res->errno = mnt_errtbl[i].errno;
 329                         return 0;
 330                 }
 331         }
 332
 333         dprintk("NFS: unrecognized MNT status code: %u\n", status);
 334         res->errno = -EACCES;
 335         return 0;
 336 }
 337
 338 static int decode_fhandle(struct xdr_stream *xdr, struct mountres *res)
 339 {
 340         struct nfs_fh *fh = res->fh;
 341         __be32 *p;
 342
 343         p = xdr_inline_decode(xdr, NFS2_FHSIZE);
 344         if (unlikely(p == NULL))
 345                 return -EIO;
 346
 347         fh->size = NFS2_FHSIZE;
 348         memcpy(fh->data, p, NFS2_FHSIZE);
 349         return 0;
 350 }
 351
 352 static int mnt_dec_mountres(struct rpc_rqst *req, __be32 *p,
 353                             struct mountres *res)
 354 {
 355         struct xdr_stream xdr;
 356         int status;
 357
 358         xdr_init_decode(&xdr, &req->rq_rcv_buf, p);
 359
 360         status = decode_status(&xdr, res);
 361         if (unlikely(status != 0 || res->errno != 0))
 362                 return status;
 363         return decode_fhandle(&xdr, res);
 364 }
 365
 366 static int decode_fhs_status(struct xdr_stream *xdr, struct mountres *res)
 367 {
 368         unsigned int i;
 369         u32 status;
 370         __be32 *p;
 371
 372         p = xdr_inline_decode(xdr, sizeof(status));
 373         if (unlikely(p == NULL))
 374                 return -EIO;
 375         status = ntohl(*p);
 376
 377         for (i = 0; i < ARRAY_SIZE(mnt3_errtbl); i++) {
 378                 if (mnt3_errtbl[i].status == status) {
 379                         res->errno = mnt3_errtbl[i].errno;
 380                         return 0;
 381                 }
 382         }
 383
 384         dprintk("NFS: unrecognized MNT3 status code: %u\n", status);
 385         res->errno = -EACCES;
 386         return 0;
 387 }
 388
 389 static int decode_fhandle3(struct xdr_stream *xdr, struct mountres *res)
 390 {
 391         struct nfs_fh *fh = res->fh;
 392         u32 size;
 393         __be32 *p;
 394
 395         p = xdr_inline_decode(xdr, sizeof(size));
 396         if (unlikely(p == NULL))
 397                 return -EIO;
 398
 399         size = ntohl(*p++);
 400         if (size > NFS3_FHSIZE || size == 0)
 401                 return -EIO;
 402
 403         p = xdr_inline_decode(xdr, size);
 404         if (unlikely(p == NULL))
 405                 return -EIO;
 406
 407         fh->size = size;
 408         memcpy(fh->data, p, size);
 409         return 0;
 410 }
 411
 412 static int decode_auth_flavors(struct xdr_stream *xdr, struct mountres *res)
 413 {
 414         rpc_authflavor_t *flavors = res->auth_flavors;
 415         unsigned int *count = res->auth_count;
 416         u32 entries, i;
 417         __be32 *p;
 418
 419         if (*count == 0)
 420                 return 0;
 421
 422         p = xdr_inline_decode(xdr, sizeof(entries));
 423         if (unlikely(p == NULL))
 424                 return -EIO;
 425         entries = ntohl(*p);
 426         dprintk("NFS: received %u auth flavors\n", entries);
 427         if (entries > NFS_MAX_SECFLAVORS)
 428                 entries = NFS_MAX_SECFLAVORS;
 429
 430         p = xdr_inline_decode(xdr, sizeof(u32) * entries);
 431         if (unlikely(p == NULL))
 432                 return -EIO;
 433
 434         if (entries > *count)
 435                 entries = *count;
 436
 437         for (i = 0; i < entries; i++) {
 438                 flavors[i] = ntohl(*p++);
 439                 dprintk("NFS:\tflavor %u: %d\n", i, flavors[i]);
 440         }
 441         *count = i;
 442
 443         return 0;
 444 }
 445
 446 static int mnt_dec_mountres3(struct rpc_rqst *req, __be32 *p,
 447                              struct mountres *res)
 448 {
 449         struct xdr_stream xdr;
 450         int status;
 451
 452         xdr_init_decode(&xdr, &req->rq_rcv_buf, p);
 453
 454         status = decode_fhs_status(&xdr, res);
 455         if (unlikely(status != 0 || res->errno != 0))
 456                 return status;
 457         status = decode_fhandle3(&xdr, res);
 458         if (unlikely(status != 0)) {
 459                 res->errno = -EBADHANDLE;
 460                 return 0;
 461         }
 462         return decode_auth_flavors(&xdr, res);
 463 }
 464
 465 static struct rpc_procinfo mnt_procedures[] = {
 466         [MOUNTPROC_MNT] = {
 467                 .p_proc         = MOUNTPROC_MNT,
 468                 .p_encode       = (kxdrproc_t)mnt_enc_dirpath,
 469                 .p_decode       = (kxdrproc_t)mnt_dec_mountres,
 470                 .p_arglen       = MNT_enc_dirpath_sz,
 471                 .p_replen       = MNT_dec_mountres_sz,
 472                 .p_statidx      = MOUNTPROC_MNT,
 473                 .p_name         = "MOUNT",
 474         },
 475         [MOUNTPROC_UMNT] = {
 476                 .p_proc         = MOUNTPROC_UMNT,
 477                 .p_encode       = (kxdrproc_t)mnt_enc_dirpath,
 478                 .p_arglen       = MNT_enc_dirpath_sz,
 479                 .p_statidx      = MOUNTPROC_UMNT,
 480                 .p_name         = "UMOUNT",
 481         },
 482 };
 483
 484 static struct rpc_procinfo mnt3_procedures[] = {
 485         [MOUNTPROC3_MNT] = {
 486                 .p_proc         = MOUNTPROC3_MNT,
 487                 .p_encode       = (kxdrproc_t)mnt_enc_dirpath,
 488                 .p_decode       = (kxdrproc_t)mnt_dec_mountres3,
 489                 .p_arglen       = MNT_enc_dirpath_sz,
 490                 .p_replen       = MNT_dec_mountres3_sz,
 491                 .p_statidx      = MOUNTPROC3_MNT,
 492                 .p_name         = "MOUNT",
 493         },
 494         [MOUNTPROC3_UMNT] = {
 495                 .p_proc         = MOUNTPROC3_UMNT,
 496                 .p_encode       = (kxdrproc_t)mnt_enc_dirpath,
 497                 .p_arglen       = MNT_enc_dirpath_sz,
 498                 .p_statidx      = MOUNTPROC3_UMNT,
 499                 .p_name         = "UMOUNT",
 500         },
 501 };
 502
 503
 504 static struct rpc_version mnt_version1 = {
 505         .number         = 1,
 506         .nrprocs        = 2,
 507         .procs          = mnt_procedures,
 508 };
 509
 510 static struct rpc_version mnt_version3 = {
 511         .number         = 3,
 512         .nrprocs        = 2,
 513         .procs          = mnt3_procedures,
 514 };
 515
 516 static struct rpc_version *mnt_version[] = {
 517         NULL,
 518         &mnt_version1,
 519         NULL,
 520         &mnt_version3,
 521 };
 522
 523 static struct rpc_stat mnt_stats;
 524
 525 static struct rpc_program mnt_program = {
 526         .name           = "mount",
 527         .number         = NFS_MNT_PROGRAM,
 528         .nrvers         = ARRAY_SIZE(mnt_version),
 529         .version        = mnt_version,
 530         .stats          = &mnt_stats,
 531 };