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. On
 143  * successful return, the auth_flavs list and auth_flav_len will be populated
 144  * with the list from the server or a faked-up list if the server didn't
 145  * provide one.
 146  */
 147 int nfs_mount(struct nfs_mount_request *info)
 148 {
 149         struct mountres result = {
 150                 .fh             = info->fh,
 151                 .auth_count     = info->auth_flav_len,
 152                 .auth_flavors   = info->auth_flavs,
 153         };
 154         struct rpc_message msg  = {
 155                 .rpc_argp       = info->dirpath,
 156                 .rpc_resp       = &result,
 157         };
 158         struct rpc_create_args args = {
 159                 .net            = info->net,
 160                 .protocol       = info->protocol,
 161                 .address        = info->sap,
 162                 .addrsize       = info->salen,
 163                 .servername     = info->hostname,
 164                 .program        = &mnt_program,
 165                 .version        = info->version,
 166                 .authflavor     = RPC_AUTH_UNIX,
 167         };
 168         struct rpc_clnt         *mnt_clnt;
 169         int                     status;
 170
 171         dprintk("NFS: sending MNT request for %s:%s\n",
 172                 (info->hostname ? info->hostname : "server"),
 173                         info->dirpath);
 174
 175         if (strlen(info->dirpath) > MNTPATHLEN)
 176                 return -ENAMETOOLONG;
 177
 178         if (info->noresvport)
 179                 args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
 180
 181         mnt_clnt = rpc_create(&args);
 182         if (IS_ERR(mnt_clnt))
 183                 goto out_clnt_err;
 184
 185         if (info->version == NFS_MNT3_VERSION)
 186                 msg.rpc_proc = &mnt_clnt->cl_procinfo[MOUNTPROC3_MNT];
 187         else
 188                 msg.rpc_proc = &mnt_clnt->cl_procinfo[MOUNTPROC_MNT];
 189
 190         status = rpc_call_sync(mnt_clnt, &msg, RPC_TASK_SOFT|RPC_TASK_TIMEOUT);
 191         rpc_shutdown_client(mnt_clnt);
 192
 193         if (status < 0)
 194                 goto out_call_err;
 195         if (result.errno != 0)
 196                 goto out_mnt_err;
 197
 198         dprintk("NFS: MNT request succeeded\n");
 199         status = 0;
 200
 201         /*
 202          * If the server didn't provide a flavor list, allow the
 203          * client to try any flavor.
 204          */
 205         if (info->version != NFS_MNT3_VERSION || *info->auth_flav_len == 0) {
 206                 dprintk("NFS: Faking up auth_flavs list\n");
 207                 info->auth_flavs[0] = RPC_AUTH_NULL;
 208                 *info->auth_flav_len = 1;
 209         }
 210 out:
 211         return status;
 212
 213 out_clnt_err:
 214         status = PTR_ERR(mnt_clnt);
 215         dprintk("NFS: failed to create MNT RPC client, status=%d\n", status);
 216         goto out;
 217
 218 out_call_err:
 219         dprintk("NFS: MNT request failed, status=%d\n", status);
 220         goto out;
 221
 222 out_mnt_err:
 223         dprintk("NFS: MNT server returned result %d\n", result.errno);
 224         status = result.errno;
 225         goto out;
 226 }
 227
 228 /**
 229  * nfs_umount - Notify a server that we have unmounted this export
 230  * @info: pointer to umount request arguments
 231  *
 232  * MOUNTPROC_UMNT is advisory, so we set a short timeout, and always
 233  * use UDP.
 234  */
 235 void nfs_umount(const struct nfs_mount_request *info)
 236 {
 237         static const struct rpc_timeout nfs_umnt_timeout = {
 238                 .to_initval = 1 * HZ,
 239                 .to_maxval = 3 * HZ,
 240                 .to_retries = 2,
 241         };
 242         struct rpc_create_args args = {
 243                 .net            = info->net,
 244                 .protocol       = IPPROTO_UDP,
 245                 .address        = info->sap,
 246                 .addrsize       = info->salen,
 247                 .timeout        = &nfs_umnt_timeout,
 248                 .servername     = info->hostname,
 249                 .program        = &mnt_program,
 250                 .version        = info->version,
 251                 .authflavor     = RPC_AUTH_UNIX,
 252                 .flags          = RPC_CLNT_CREATE_NOPING,
 253         };
 254         struct rpc_message msg  = {
 255                 .rpc_argp       = info->dirpath,
 256         };
 257         struct rpc_clnt *clnt;
 258         int status;
 259
 260         if (strlen(info->dirpath) > MNTPATHLEN)
 261                 return;
 262
 263         if (info->noresvport)
 264                 args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
 265
 266         clnt = rpc_create(&args);
 267         if (IS_ERR(clnt))
 268                 goto out_clnt_err;
 269
 270         dprintk("NFS: sending UMNT request for %s:%s\n",
 271                 (info->hostname ? info->hostname : "server"), info->dirpath);
 272
 273         if (info->version == NFS_MNT3_VERSION)
 274                 msg.rpc_proc = &clnt->cl_procinfo[MOUNTPROC3_UMNT];
 275         else
 276                 msg.rpc_proc = &clnt->cl_procinfo[MOUNTPROC_UMNT];
 277
 278         status = rpc_call_sync(clnt, &msg, 0);
 279         rpc_shutdown_client(clnt);
 280
 281         if (unlikely(status < 0))
 282                 goto out_call_err;
 283
 284         return;
 285
 286 out_clnt_err:
 287         dprintk("NFS: failed to create UMNT RPC client, status=%ld\n",
 288                         PTR_ERR(clnt));
 289         return;
 290
 291 out_call_err:
 292         dprintk("NFS: UMNT request failed, status=%d\n", status);
 293 }
 294
 295 /*
 296  * XDR encode/decode functions for MOUNT
 297  */
 298
 299 static void encode_mntdirpath(struct xdr_stream *xdr, const char *pathname)
 300 {
 301         const u32 pathname_len = strlen(pathname);
 302         __be32 *p;
 303
 304         p = xdr_reserve_space(xdr, 4 + pathname_len);
 305         xdr_encode_opaque(p, pathname, pathname_len);
 306 }
 307
 308 static void mnt_xdr_enc_dirpath(struct rpc_rqst *req, struct xdr_stream *xdr,
 309                                 const char *dirpath)
 310 {
 311         encode_mntdirpath(xdr, dirpath);
 312 }
 313
 314 /*
 315  * RFC 1094: "A non-zero status indicates some sort of error.  In this
 316  * case, the status is a UNIX error number."  This can be problematic
 317  * if the server and client use different errno values for the same
 318  * error.
 319  *
 320  * However, the OpenGroup XNFS spec provides a simple mapping that is
 321  * independent of local errno values on the server and the client.
 322  */
 323 static int decode_status(struct xdr_stream *xdr, struct mountres *res)
 324 {
 325         unsigned int i;
 326         u32 status;
 327         __be32 *p;
 328
 329         p = xdr_inline_decode(xdr, 4);
 330         if (unlikely(p == NULL))
 331                 return -EIO;
 332         status = be32_to_cpup(p);
 333
 334         for (i = 0; i < ARRAY_SIZE(mnt_errtbl); i++) {
 335                 if (mnt_errtbl[i].status == status) {
 336                         res->errno = mnt_errtbl[i].errno;
 337                         return 0;
 338                 }
 339         }
 340
 341         dprintk("NFS: unrecognized MNT status code: %u\n", status);
 342         res->errno = -EACCES;
 343         return 0;
 344 }
 345
 346 static int decode_fhandle(struct xdr_stream *xdr, struct mountres *res)
 347 {
 348         struct nfs_fh *fh = res->fh;
 349         __be32 *p;
 350
 351         p = xdr_inline_decode(xdr, NFS2_FHSIZE);
 352         if (unlikely(p == NULL))
 353                 return -EIO;
 354
 355         fh->size = NFS2_FHSIZE;
 356         memcpy(fh->data, p, NFS2_FHSIZE);
 357         return 0;
 358 }
 359
 360 static int mnt_xdr_dec_mountres(struct rpc_rqst *req,
 361                                 struct xdr_stream *xdr,
 362                                 struct mountres *res)
 363 {
 364         int status;
 365
 366         status = decode_status(xdr, res);
 367         if (unlikely(status != 0 || res->errno != 0))
 368                 return status;
 369         return decode_fhandle(xdr, res);
 370 }
 371
 372 static int decode_fhs_status(struct xdr_stream *xdr, struct mountres *res)
 373 {
 374         unsigned int i;
 375         u32 status;
 376         __be32 *p;
 377
 378         p = xdr_inline_decode(xdr, 4);
 379         if (unlikely(p == NULL))
 380                 return -EIO;
 381         status = be32_to_cpup(p);
 382
 383         for (i = 0; i < ARRAY_SIZE(mnt3_errtbl); i++) {
 384                 if (mnt3_errtbl[i].status == status) {
 385                         res->errno = mnt3_errtbl[i].errno;
 386                         return 0;
 387                 }
 388         }
 389
 390         dprintk("NFS: unrecognized MNT3 status code: %u\n", status);
 391         res->errno = -EACCES;
 392         return 0;
 393 }
 394
 395 static int decode_fhandle3(struct xdr_stream *xdr, struct mountres *res)
 396 {
 397         struct nfs_fh *fh = res->fh;
 398         u32 size;
 399         __be32 *p;
 400
 401         p = xdr_inline_decode(xdr, 4);
 402         if (unlikely(p == NULL))
 403                 return -EIO;
 404
 405         size = be32_to_cpup(p);
 406         if (size > NFS3_FHSIZE || size == 0)
 407                 return -EIO;
 408
 409         p = xdr_inline_decode(xdr, size);
 410         if (unlikely(p == NULL))
 411                 return -EIO;
 412
 413         fh->size = size;
 414         memcpy(fh->data, p, size);
 415         return 0;
 416 }
 417
 418 static int decode_auth_flavors(struct xdr_stream *xdr, struct mountres *res)
 419 {
 420         rpc_authflavor_t *flavors = res->auth_flavors;
 421         unsigned int *count = res->auth_count;
 422         u32 entries, i;
 423         __be32 *p;
 424
 425         if (*count == 0)
 426                 return 0;
 427
 428         p = xdr_inline_decode(xdr, 4);
 429         if (unlikely(p == NULL))
 430                 return -EIO;
 431         entries = be32_to_cpup(p);
 432         dprintk("NFS: received %u auth flavors\n", entries);
 433         if (entries > NFS_MAX_SECFLAVORS)
 434                 entries = NFS_MAX_SECFLAVORS;
 435
 436         p = xdr_inline_decode(xdr, 4 * entries);
 437         if (unlikely(p == NULL))
 438                 return -EIO;
 439
 440         if (entries > *count)
 441                 entries = *count;
 442
 443         for (i = 0; i < entries; i++) {
 444                 flavors[i] = be32_to_cpup(p++);
 445                 dprintk("NFS:   auth flavor[%u]: %d\n", i, flavors[i]);
 446         }
 447         *count = i;
 448
 449         return 0;
 450 }
 451
 452 static int mnt_xdr_dec_mountres3(struct rpc_rqst *req,
 453                                  struct xdr_stream *xdr,
 454                                  struct mountres *res)
 455 {
 456         int status;
 457
 458         status = decode_fhs_status(xdr, res);
 459         if (unlikely(status != 0 || res->errno != 0))
 460                 return status;
 461         status = decode_fhandle3(xdr, res);
 462         if (unlikely(status != 0)) {
 463                 res->errno = -EBADHANDLE;
 464                 return 0;
 465         }
 466         return decode_auth_flavors(xdr, res);
 467 }
 468
 469 static struct rpc_procinfo mnt_procedures[] = {
 470         [MOUNTPROC_MNT] = {
 471                 .p_proc         = MOUNTPROC_MNT,
 472                 .p_encode       = (kxdreproc_t)mnt_xdr_enc_dirpath,
 473                 .p_decode       = (kxdrdproc_t)mnt_xdr_dec_mountres,
 474                 .p_arglen       = MNT_enc_dirpath_sz,
 475                 .p_replen       = MNT_dec_mountres_sz,
 476                 .p_statidx      = MOUNTPROC_MNT,
 477                 .p_name         = "MOUNT",
 478         },
 479         [MOUNTPROC_UMNT] = {
 480                 .p_proc         = MOUNTPROC_UMNT,
 481                 .p_encode       = (kxdreproc_t)mnt_xdr_enc_dirpath,
 482                 .p_arglen       = MNT_enc_dirpath_sz,
 483                 .p_statidx      = MOUNTPROC_UMNT,
 484                 .p_name         = "UMOUNT",
 485         },
 486 };
 487
 488 static struct rpc_procinfo mnt3_procedures[] = {
 489         [MOUNTPROC3_MNT] = {
 490                 .p_proc         = MOUNTPROC3_MNT,
 491                 .p_encode       = (kxdreproc_t)mnt_xdr_enc_dirpath,
 492                 .p_decode       = (kxdrdproc_t)mnt_xdr_dec_mountres3,
 493                 .p_arglen       = MNT_enc_dirpath_sz,
 494                 .p_replen       = MNT_dec_mountres3_sz,
 495                 .p_statidx      = MOUNTPROC3_MNT,
 496                 .p_name         = "MOUNT",
 497         },
 498         [MOUNTPROC3_UMNT] = {
 499                 .p_proc         = MOUNTPROC3_UMNT,
 500                 .p_encode       = (kxdreproc_t)mnt_xdr_enc_dirpath,
 501                 .p_arglen       = MNT_enc_dirpath_sz,
 502                 .p_statidx      = MOUNTPROC3_UMNT,
 503                 .p_name         = "UMOUNT",
 504         },
 505 };
 506
 507
 508 static const struct rpc_version mnt_version1 = {
 509         .number         = 1,
 510         .nrprocs        = ARRAY_SIZE(mnt_procedures),
 511         .procs          = mnt_procedures,
 512 };
 513
 514 static const struct rpc_version mnt_version3 = {
 515         .number         = 3,
 516         .nrprocs        = ARRAY_SIZE(mnt3_procedures),
 517         .procs          = mnt3_procedures,
 518 };
 519
 520 static const struct rpc_version *mnt_version[] = {
 521         NULL,
 522         &mnt_version1,
 523         NULL,
 524         &mnt_version3,
 525 };
 526
 527 static struct rpc_stat mnt_stats;
 528
 529 static const struct rpc_program mnt_program = {
 530         .name           = "mount",
 531         .number         = NFS_MNT_PROGRAM,
 532         .nrvers         = ARRAY_SIZE(mnt_version),
 533         .version        = mnt_version,
 534         .stats          = &mnt_stats,
 535 };