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
  37 /*
  38  * XDR argument and result sizes
  39  */
  40 #define MNT_enc_dirpath_sz      encode_dirpath_sz
  41
  42 /*
  43  * Defined by RFC 1094, section A.5
  44  */
  45 enum {
  46         MOUNTPROC_NULL          = 0,
  47         MOUNTPROC_MNT           = 1,
  48         MOUNTPROC_DUMP          = 2,
  49         MOUNTPROC_UMNT          = 3,
  50         MOUNTPROC_UMNTALL       = 4,
  51         MOUNTPROC_EXPORT        = 5,
  52 };
  53
  54 /*
  55  * Defined by RFC 1813, section 5.2
  56  */
  57 enum {
  58         MOUNTPROC3_NULL         = 0,
  59         MOUNTPROC3_MNT          = 1,
  60         MOUNTPROC3_DUMP         = 2,
  61         MOUNTPROC3_UMNT         = 3,
  62         MOUNTPROC3_UMNTALL      = 4,
  63         MOUNTPROC3_EXPORT       = 5,
  64 };
  65
  66 static struct rpc_program       mnt_program;
  67
  68 /*
  69  * Defined by OpenGroup XNFS Version 3W, chapter 8
  70  */
  71 enum mountstat {
  72         MNT_OK                  = 0,
  73         MNT_EPERM               = 1,
  74         MNT_ENOENT              = 2,
  75         MNT_EACCES              = 13,
  76         MNT_EINVAL              = 22,
  77 };
  78
  79 static struct {
  80         u32 status;
  81         int errno;
  82 } mnt_errtbl[] = {
  83         { .status = MNT_OK,                     .errno = 0,             },
  84         { .status = MNT_EPERM,                  .errno = -EPERM,        },
  85         { .status = MNT_ENOENT,                 .errno = -ENOENT,       },
  86         { .status = MNT_EACCES,                 .errno = -EACCES,       },
  87         { .status = MNT_EINVAL,                 .errno = -EINVAL,       },
  88 };
  89
  90 /*
  91  * Defined by RFC 1813, section 5.1.5
  92  */
  93 enum mountstat3 {
  94         MNT3_OK                 = 0,            /* no error */
  95         MNT3ERR_PERM            = 1,            /* Not owner */
  96         MNT3ERR_NOENT           = 2,            /* No such file or directory */
  97         MNT3ERR_IO              = 5,            /* I/O error */
  98         MNT3ERR_ACCES           = 13,           /* Permission denied */
  99         MNT3ERR_NOTDIR          = 20,           /* Not a directory */
 100         MNT3ERR_INVAL           = 22,           /* Invalid argument */
 101         MNT3ERR_NAMETOOLONG     = 63,           /* Filename too long */
 102         MNT3ERR_NOTSUPP         = 10004,        /* Operation not supported */
 103         MNT3ERR_SERVERFAULT     = 10006,        /* A failure on the server */
 104 };
 105
 106 static struct {
 107         u32 status;
 108         int errno;
 109 } mnt3_errtbl[] = {
 110         { .status = MNT3_OK,                    .errno = 0,             },
 111         { .status = MNT3ERR_PERM,               .errno = -EPERM,        },
 112         { .status = MNT3ERR_NOENT,              .errno = -ENOENT,       },
 113         { .status = MNT3ERR_IO,                 .errno = -EIO,          },
 114         { .status = MNT3ERR_ACCES,              .errno = -EACCES,       },
 115         { .status = MNT3ERR_NOTDIR,             .errno = -ENOTDIR,      },
 116         { .status = MNT3ERR_INVAL,              .errno = -EINVAL,       },
 117         { .status = MNT3ERR_NAMETOOLONG,        .errno = -ENAMETOOLONG, },
 118         { .status = MNT3ERR_NOTSUPP,            .errno = -ENOTSUPP,     },
 119         { .status = MNT3ERR_SERVERFAULT,        .errno = -ESERVERFAULT, },
 120 };
 121
 122 struct mountres {
 123         int errno;
 124         struct nfs_fh *fh;
 125 };
 126
 127 struct mnt_fhstatus {
 128         u32 status;
 129         struct nfs_fh *fh;
 130 };
 131
 132 /**
 133  * nfs_mount - Obtain an NFS file handle for the given host and path
 134  * @info: pointer to mount request arguments
 135  *
 136  * Uses default timeout parameters specified by underlying transport.
 137  */
 138 int nfs_mount(struct nfs_mount_request *info)
 139 {
 140         struct mnt_fhstatus     result = {
 141                 .fh             = info->fh
 142         };
 143         struct rpc_message msg  = {
 144                 .rpc_argp       = info->dirpath,
 145                 .rpc_resp       = &result,
 146         };
 147         struct rpc_create_args args = {
 148                 .protocol       = info->protocol,
 149                 .address        = info->sap,
 150                 .addrsize       = info->salen,
 151                 .servername     = info->hostname,
 152                 .program        = &mnt_program,
 153                 .version        = info->version,
 154                 .authflavor     = RPC_AUTH_UNIX,
 155         };
 156         struct rpc_clnt         *mnt_clnt;
 157         int                     status;
 158
 159         dprintk("NFS: sending MNT request for %s:%s\n",
 160                 (info->hostname ? info->hostname : "server"),
 161                         info->dirpath);
 162
 163         if (info->noresvport)
 164                 args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
 165
 166         mnt_clnt = rpc_create(&args);
 167         if (IS_ERR(mnt_clnt))
 168                 goto out_clnt_err;
 169
 170         if (info->version == NFS_MNT3_VERSION)
 171                 msg.rpc_proc = &mnt_clnt->cl_procinfo[MOUNTPROC3_MNT];
 172         else
 173                 msg.rpc_proc = &mnt_clnt->cl_procinfo[MOUNTPROC_MNT];
 174
 175         status = rpc_call_sync(mnt_clnt, &msg, 0);
 176         rpc_shutdown_client(mnt_clnt);
 177
 178         if (status < 0)
 179                 goto out_call_err;
 180         if (result.status != 0)
 181                 goto out_mnt_err;
 182
 183         dprintk("NFS: MNT request succeeded\n");
 184         status = 0;
 185
 186 out:
 187         return status;
 188
 189 out_clnt_err:
 190         status = PTR_ERR(mnt_clnt);
 191         dprintk("NFS: failed to create RPC client, status=%d\n", status);
 192         goto out;
 193
 194 out_call_err:
 195         dprintk("NFS: failed to start MNT request, status=%d\n", status);
 196         goto out;
 197
 198 out_mnt_err:
 199         dprintk("NFS: MNT server returned result %d\n", result.status);
 200         status = nfs_stat_to_errno(result.status);
 201         goto out;
 202 }
 203
 204 /*
 205  * XDR encode/decode functions for MOUNT
 206  */
 207
 208 static int encode_mntdirpath(struct xdr_stream *xdr, const char *pathname)
 209 {
 210         const u32 pathname_len = strlen(pathname);
 211         __be32 *p;
 212
 213         if (unlikely(pathname_len > MNTPATHLEN))
 214                 return -EIO;
 215
 216         p = xdr_reserve_space(xdr, sizeof(u32) + pathname_len);
 217         if (unlikely(p == NULL))
 218                 return -EIO;
 219         xdr_encode_opaque(p, pathname, pathname_len);
 220
 221         return 0;
 222 }
 223
 224 static int mnt_enc_dirpath(struct rpc_rqst *req, __be32 *p,
 225                            const char *dirpath)
 226 {
 227         struct xdr_stream xdr;
 228
 229         xdr_init_encode(&xdr, &req->rq_snd_buf, p);
 230         return encode_mntdirpath(&xdr, dirpath);
 231 }
 232
 233 static int xdr_decode_fhstatus(struct rpc_rqst *req, __be32 *p,
 234                                struct mnt_fhstatus *res)
 235 {
 236         struct nfs_fh *fh = res->fh;
 237
 238         if ((res->status = ntohl(*p++)) == 0) {
 239                 fh->size = NFS2_FHSIZE;
 240                 memcpy(fh->data, p, NFS2_FHSIZE);
 241         }
 242         return 0;
 243 }
 244
 245 /*
 246  * RFC 1094: "A non-zero status indicates some sort of error.  In this
 247  * case, the status is a UNIX error number."  This can be problematic
 248  * if the server and client use different errno values for the same
 249  * error.
 250  *
 251  * However, the OpenGroup XNFS spec provides a simple mapping that is
 252  * independent of local errno values on the server and the client.
 253  */
 254 static int decode_status(struct xdr_stream *xdr, struct mountres *res)
 255 {
 256         unsigned int i;
 257         u32 status;
 258         __be32 *p;
 259
 260         p = xdr_inline_decode(xdr, sizeof(status));
 261         if (unlikely(p == NULL))
 262                 return -EIO;
 263         status = ntohl(*p);
 264
 265         for (i = 0; i <= ARRAY_SIZE(mnt_errtbl); i++) {
 266                 if (mnt_errtbl[i].status == status) {
 267                         res->errno = mnt_errtbl[i].errno;
 268                         return 0;
 269                 }
 270         }
 271
 272         dprintk("NFS: unrecognized MNT status code: %u\n", status);
 273         res->errno = -EACCES;
 274         return 0;
 275 }
 276
 277 static int decode_fhandle(struct xdr_stream *xdr, struct mountres *res)
 278 {
 279         struct nfs_fh *fh = res->fh;
 280         __be32 *p;
 281
 282         p = xdr_inline_decode(xdr, NFS2_FHSIZE);
 283         if (unlikely(p == NULL))
 284                 return -EIO;
 285
 286         fh->size = NFS2_FHSIZE;
 287         memcpy(fh->data, p, NFS2_FHSIZE);
 288         return 0;
 289 }
 290
 291 static int decode_fhs_status(struct xdr_stream *xdr, struct mountres *res)
 292 {
 293         unsigned int i;
 294         u32 status;
 295         __be32 *p;
 296
 297         p = xdr_inline_decode(xdr, sizeof(status));
 298         if (unlikely(p == NULL))
 299                 return -EIO;
 300         status = ntohl(*p);
 301
 302         for (i = 0; i <= ARRAY_SIZE(mnt3_errtbl); i++) {
 303                 if (mnt3_errtbl[i].status == status) {
 304                         res->errno = mnt3_errtbl[i].errno;
 305                         return 0;
 306                 }
 307         }
 308
 309         dprintk("NFS: unrecognized MNT3 status code: %u\n", status);
 310         res->errno = -EACCES;
 311         return 0;
 312 }
 313
 314 static int decode_fhandle3(struct xdr_stream *xdr, struct mountres *res)
 315 {
 316         struct nfs_fh *fh = res->fh;
 317         u32 size;
 318         __be32 *p;
 319
 320         p = xdr_inline_decode(xdr, sizeof(size));
 321         if (unlikely(p == NULL))
 322                 return -EIO;
 323
 324         size = ntohl(*p++);
 325         if (size > NFS3_FHSIZE || size == 0)
 326                 return -EIO;
 327
 328         p = xdr_inline_decode(xdr, size);
 329         if (unlikely(p == NULL))
 330                 return -EIO;
 331
 332         fh->size = size;
 333         memcpy(fh->data, p, size);
 334         return 0;
 335 }
 336
 337 static int xdr_decode_fhstatus3(struct rpc_rqst *req, __be32 *p,
 338                                 struct mnt_fhstatus *res)
 339 {
 340         struct nfs_fh *fh = res->fh;
 341         unsigned size;
 342
 343         if ((res->status = ntohl(*p++)) == 0) {
 344                 size = ntohl(*p++);
 345                 if (size <= NFS3_FHSIZE && size != 0) {
 346                         fh->size = size;
 347                         memcpy(fh->data, p, size);
 348                 } else
 349                         res->status = -EBADHANDLE;
 350         }
 351         return 0;
 352 }
 353
 354 #define MNT_fhstatus_sz         (1 + 8)
 355 #define MNT_fhstatus3_sz        (1 + 16)
 356
 357 static struct rpc_procinfo mnt_procedures[] = {
 358         [MOUNTPROC_MNT] = {
 359                 .p_proc         = MOUNTPROC_MNT,
 360                 .p_encode       = (kxdrproc_t)mnt_enc_dirpath,
 361                 .p_decode       = (kxdrproc_t) xdr_decode_fhstatus,
 362                 .p_arglen       = MNT_enc_dirpath_sz,
 363                 .p_replen       = MNT_fhstatus_sz,
 364                 .p_statidx      = MOUNTPROC_MNT,
 365                 .p_name         = "MOUNT",
 366         },
 367 };
 368
 369 static struct rpc_procinfo mnt3_procedures[] = {
 370         [MOUNTPROC3_MNT] = {
 371                 .p_proc         = MOUNTPROC3_MNT,
 372                 .p_encode       = (kxdrproc_t)mnt_enc_dirpath,
 373                 .p_decode       = (kxdrproc_t) xdr_decode_fhstatus3,
 374                 .p_arglen       = MNT_enc_dirpath_sz,
 375                 .p_replen       = MNT_fhstatus3_sz,
 376                 .p_statidx      = MOUNTPROC3_MNT,
 377                 .p_name         = "MOUNT",
 378         },
 379 };
 380
 381
 382 static struct rpc_version mnt_version1 = {
 383         .number         = 1,
 384         .nrprocs        = 2,
 385         .procs          = mnt_procedures,
 386 };
 387
 388 static struct rpc_version mnt_version3 = {
 389         .number         = 3,
 390         .nrprocs        = 2,
 391         .procs          = mnt3_procedures,
 392 };
 393
 394 static struct rpc_version *mnt_version[] = {
 395         NULL,
 396         &mnt_version1,
 397         NULL,
 398         &mnt_version3,
 399 };
 400
 401 static struct rpc_stat mnt_stats;
 402
 403 static struct rpc_program mnt_program = {
 404         .name           = "mount",
 405         .number         = NFS_MNT_PROGRAM,
 406         .nrvers         = ARRAY_SIZE(mnt_version),
 407         .version        = mnt_version,
 408         .stats          = &mnt_stats,
 409 };