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  * XDR encode/decode functions for MOUNT
 214  */
 215
 216 static int encode_mntdirpath(struct xdr_stream *xdr, const char *pathname)
 217 {
 218         const u32 pathname_len = strlen(pathname);
 219         __be32 *p;
 220
 221         if (unlikely(pathname_len > MNTPATHLEN))
 222                 return -EIO;
 223
 224         p = xdr_reserve_space(xdr, sizeof(u32) + pathname_len);
 225         if (unlikely(p == NULL))
 226                 return -EIO;
 227         xdr_encode_opaque(p, pathname, pathname_len);
 228
 229         return 0;
 230 }
 231
 232 static int mnt_enc_dirpath(struct rpc_rqst *req, __be32 *p,
 233                            const char *dirpath)
 234 {
 235         struct xdr_stream xdr;
 236
 237         xdr_init_encode(&xdr, &req->rq_snd_buf, p);
 238         return encode_mntdirpath(&xdr, dirpath);
 239 }
 240
 241 /*
 242  * RFC 1094: "A non-zero status indicates some sort of error.  In this
 243  * case, the status is a UNIX error number."  This can be problematic
 244  * if the server and client use different errno values for the same
 245  * error.
 246  *
 247  * However, the OpenGroup XNFS spec provides a simple mapping that is
 248  * independent of local errno values on the server and the client.
 249  */
 250 static int decode_status(struct xdr_stream *xdr, struct mountres *res)
 251 {
 252         unsigned int i;
 253         u32 status;
 254         __be32 *p;
 255
 256         p = xdr_inline_decode(xdr, sizeof(status));
 257         if (unlikely(p == NULL))
 258                 return -EIO;
 259         status = ntohl(*p);
 260
 261         for (i = 0; i <= ARRAY_SIZE(mnt_errtbl); i++) {
 262                 if (mnt_errtbl[i].status == status) {
 263                         res->errno = mnt_errtbl[i].errno;
 264                         return 0;
 265                 }
 266         }
 267
 268         dprintk("NFS: unrecognized MNT status code: %u\n", status);
 269         res->errno = -EACCES;
 270         return 0;
 271 }
 272
 273 static int decode_fhandle(struct xdr_stream *xdr, struct mountres *res)
 274 {
 275         struct nfs_fh *fh = res->fh;
 276         __be32 *p;
 277
 278         p = xdr_inline_decode(xdr, NFS2_FHSIZE);
 279         if (unlikely(p == NULL))
 280                 return -EIO;
 281
 282         fh->size = NFS2_FHSIZE;
 283         memcpy(fh->data, p, NFS2_FHSIZE);
 284         return 0;
 285 }
 286
 287 static int mnt_dec_mountres(struct rpc_rqst *req, __be32 *p,
 288                             struct mountres *res)
 289 {
 290         struct xdr_stream xdr;
 291         int status;
 292
 293         xdr_init_decode(&xdr, &req->rq_rcv_buf, p);
 294
 295         status = decode_status(&xdr, res);
 296         if (unlikely(status != 0 || res->errno != 0))
 297                 return status;
 298         return decode_fhandle(&xdr, res);
 299 }
 300
 301 static int decode_fhs_status(struct xdr_stream *xdr, struct mountres *res)
 302 {
 303         unsigned int i;
 304         u32 status;
 305         __be32 *p;
 306
 307         p = xdr_inline_decode(xdr, sizeof(status));
 308         if (unlikely(p == NULL))
 309                 return -EIO;
 310         status = ntohl(*p);
 311
 312         for (i = 0; i <= ARRAY_SIZE(mnt3_errtbl); i++) {
 313                 if (mnt3_errtbl[i].status == status) {
 314                         res->errno = mnt3_errtbl[i].errno;
 315                         return 0;
 316                 }
 317         }
 318
 319         dprintk("NFS: unrecognized MNT3 status code: %u\n", status);
 320         res->errno = -EACCES;
 321         return 0;
 322 }
 323
 324 static int decode_fhandle3(struct xdr_stream *xdr, struct mountres *res)
 325 {
 326         struct nfs_fh *fh = res->fh;
 327         u32 size;
 328         __be32 *p;
 329
 330         p = xdr_inline_decode(xdr, sizeof(size));
 331         if (unlikely(p == NULL))
 332                 return -EIO;
 333
 334         size = ntohl(*p++);
 335         if (size > NFS3_FHSIZE || size == 0)
 336                 return -EIO;
 337
 338         p = xdr_inline_decode(xdr, size);
 339         if (unlikely(p == NULL))
 340                 return -EIO;
 341
 342         fh->size = size;
 343         memcpy(fh->data, p, size);
 344         return 0;
 345 }
 346
 347 static int decode_auth_flavors(struct xdr_stream *xdr, struct mountres *res)
 348 {
 349         rpc_authflavor_t *flavors = res->auth_flavors;
 350         unsigned int *count = res->auth_count;
 351         u32 entries, i;
 352         __be32 *p;
 353
 354         if (*count == 0)
 355                 return 0;
 356
 357         p = xdr_inline_decode(xdr, sizeof(entries));
 358         if (unlikely(p == NULL))
 359                 return -EIO;
 360         entries = ntohl(*p);
 361         dprintk("NFS: received %u auth flavors\n", entries);
 362         if (entries > NFS_MAX_SECFLAVORS)
 363                 entries = NFS_MAX_SECFLAVORS;
 364
 365         p = xdr_inline_decode(xdr, sizeof(u32) * entries);
 366         if (unlikely(p == NULL))
 367                 return -EIO;
 368
 369         if (entries > *count)
 370                 entries = *count;
 371
 372         for (i = 0; i < entries; i++) {
 373                 flavors[i] = ntohl(*p++);
 374                 dprintk("NFS:\tflavor %u: %d\n", i, flavors[i]);
 375         }
 376         *count = i;
 377
 378         return 0;
 379 }
 380
 381 static int mnt_dec_mountres3(struct rpc_rqst *req, __be32 *p,
 382                              struct mountres *res)
 383 {
 384         struct xdr_stream xdr;
 385         int status;
 386
 387         xdr_init_decode(&xdr, &req->rq_rcv_buf, p);
 388
 389         status = decode_fhs_status(&xdr, res);
 390         if (unlikely(status != 0 || res->errno != 0))
 391                 return status;
 392         status = decode_fhandle3(&xdr, res);
 393         if (unlikely(status != 0)) {
 394                 res->errno = -EBADHANDLE;
 395                 return 0;
 396         }
 397         return decode_auth_flavors(&xdr, res);
 398 }
 399
 400 static struct rpc_procinfo mnt_procedures[] = {
 401         [MOUNTPROC_MNT] = {
 402                 .p_proc         = MOUNTPROC_MNT,
 403                 .p_encode       = (kxdrproc_t)mnt_enc_dirpath,
 404                 .p_decode       = (kxdrproc_t)mnt_dec_mountres,
 405                 .p_arglen       = MNT_enc_dirpath_sz,
 406                 .p_replen       = MNT_dec_mountres_sz,
 407                 .p_statidx      = MOUNTPROC_MNT,
 408                 .p_name         = "MOUNT",
 409         },
 410 };
 411
 412 static struct rpc_procinfo mnt3_procedures[] = {
 413         [MOUNTPROC3_MNT] = {
 414                 .p_proc         = MOUNTPROC3_MNT,
 415                 .p_encode       = (kxdrproc_t)mnt_enc_dirpath,
 416                 .p_decode       = (kxdrproc_t)mnt_dec_mountres3,
 417                 .p_arglen       = MNT_enc_dirpath_sz,
 418                 .p_replen       = MNT_dec_mountres3_sz,
 419                 .p_statidx      = MOUNTPROC3_MNT,
 420                 .p_name         = "MOUNT",
 421         },
 422 };
 423
 424
 425 static struct rpc_version mnt_version1 = {
 426         .number         = 1,
 427         .nrprocs        = 2,
 428         .procs          = mnt_procedures,
 429 };
 430
 431 static struct rpc_version mnt_version3 = {
 432         .number         = 3,
 433         .nrprocs        = 2,
 434         .procs          = mnt3_procedures,
 435 };
 436
 437 static struct rpc_version *mnt_version[] = {
 438         NULL,
 439         &mnt_version1,
 440         NULL,
 441         &mnt_version3,
 442 };
 443
 444 static struct rpc_stat mnt_stats;
 445
 446 static struct rpc_program mnt_program = {
 447         .name           = "mount",
 448         .number         = NFS_MNT_PROGRAM,
 449         .nrvers         = ARRAY_SIZE(mnt_version),
 450         .version        = mnt_version,
 451         .stats          = &mnt_stats,
 452 };