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.5
  25  */
  26 enum {
  27         MOUNTPROC_NULL          = 0,
  28         MOUNTPROC_MNT           = 1,
  29         MOUNTPROC_DUMP          = 2,
  30         MOUNTPROC_UMNT          = 3,
  31         MOUNTPROC_UMNTALL       = 4,
  32         MOUNTPROC_EXPORT        = 5,
  33 };
  34
  35 /*
  36  * Defined by RFC 1813, section 5.2
  37  */
  38 enum {
  39         MOUNTPROC3_NULL         = 0,
  40         MOUNTPROC3_MNT          = 1,
  41         MOUNTPROC3_DUMP         = 2,
  42         MOUNTPROC3_UMNT         = 3,
  43         MOUNTPROC3_UMNTALL      = 4,
  44         MOUNTPROC3_EXPORT       = 5,
  45 };
  46
  47 static struct rpc_program       mnt_program;
  48
  49 struct mnt_fhstatus {
  50         u32 status;
  51         struct nfs_fh *fh;
  52 };
  53
  54 /**
  55  * nfs_mount - Obtain an NFS file handle for the given host and path
  56  * @info: pointer to mount request arguments
  57  *
  58  * Uses default timeout parameters specified by underlying transport.
  59  */
  60 int nfs_mount(struct nfs_mount_request *info)
  61 {
  62         struct mnt_fhstatus     result = {
  63                 .fh             = info->fh
  64         };
  65         struct rpc_message msg  = {
  66                 .rpc_argp       = info->dirpath,
  67                 .rpc_resp       = &result,
  68         };
  69         struct rpc_create_args args = {
  70                 .protocol       = info->protocol,
  71                 .address        = info->sap,
  72                 .addrsize       = info->salen,
  73                 .servername     = info->hostname,
  74                 .program        = &mnt_program,
  75                 .version        = info->version,
  76                 .authflavor     = RPC_AUTH_UNIX,
  77         };
  78         struct rpc_clnt         *mnt_clnt;
  79         int                     status;
  80
  81         dprintk("NFS: sending MNT request for %s:%s\n",
  82                 (info->hostname ? info->hostname : "server"),
  83                         info->dirpath);
  84
  85         if (info->noresvport)
  86                 args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
  87
  88         mnt_clnt = rpc_create(&args);
  89         if (IS_ERR(mnt_clnt))
  90                 goto out_clnt_err;
  91
  92         if (info->version == NFS_MNT3_VERSION)
  93                 msg.rpc_proc = &mnt_clnt->cl_procinfo[MOUNTPROC3_MNT];
  94         else
  95                 msg.rpc_proc = &mnt_clnt->cl_procinfo[MOUNTPROC_MNT];
  96
  97         status = rpc_call_sync(mnt_clnt, &msg, 0);
  98         rpc_shutdown_client(mnt_clnt);
  99
 100         if (status < 0)
 101                 goto out_call_err;
 102         if (result.status != 0)
 103                 goto out_mnt_err;
 104
 105         dprintk("NFS: MNT request succeeded\n");
 106         status = 0;
 107
 108 out:
 109         return status;
 110
 111 out_clnt_err:
 112         status = PTR_ERR(mnt_clnt);
 113         dprintk("NFS: failed to create RPC client, status=%d\n", status);
 114         goto out;
 115
 116 out_call_err:
 117         dprintk("NFS: failed to start MNT request, status=%d\n", status);
 118         goto out;
 119
 120 out_mnt_err:
 121         dprintk("NFS: MNT server returned result %d\n", result.status);
 122         status = nfs_stat_to_errno(result.status);
 123         goto out;
 124 }
 125
 126 /*
 127  * XDR encode/decode functions for MOUNT
 128  */
 129 static int xdr_encode_dirpath(struct rpc_rqst *req, __be32 *p,
 130                               const char *path)
 131 {
 132         p = xdr_encode_string(p, path);
 133
 134         req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
 135         return 0;
 136 }
 137
 138 static int xdr_decode_fhstatus(struct rpc_rqst *req, __be32 *p,
 139                                struct mnt_fhstatus *res)
 140 {
 141         struct nfs_fh *fh = res->fh;
 142
 143         if ((res->status = ntohl(*p++)) == 0) {
 144                 fh->size = NFS2_FHSIZE;
 145                 memcpy(fh->data, p, NFS2_FHSIZE);
 146         }
 147         return 0;
 148 }
 149
 150 static int xdr_decode_fhstatus3(struct rpc_rqst *req, __be32 *p,
 151                                 struct mnt_fhstatus *res)
 152 {
 153         struct nfs_fh *fh = res->fh;
 154         unsigned size;
 155
 156         if ((res->status = ntohl(*p++)) == 0) {
 157                 size = ntohl(*p++);
 158                 if (size <= NFS3_FHSIZE && size != 0) {
 159                         fh->size = size;
 160                         memcpy(fh->data, p, size);
 161                 } else
 162                         res->status = -EBADHANDLE;
 163         }
 164         return 0;
 165 }
 166
 167 #define MNT_dirpath_sz          (1 + 256)
 168 #define MNT_fhstatus_sz         (1 + 8)
 169 #define MNT_fhstatus3_sz        (1 + 16)
 170
 171 static struct rpc_procinfo mnt_procedures[] = {
 172         [MOUNTPROC_MNT] = {
 173                 .p_proc         = MOUNTPROC_MNT,
 174                 .p_encode       = (kxdrproc_t) xdr_encode_dirpath,
 175                 .p_decode       = (kxdrproc_t) xdr_decode_fhstatus,
 176                 .p_arglen       = MNT_dirpath_sz,
 177                 .p_replen       = MNT_fhstatus_sz,
 178                 .p_statidx      = MOUNTPROC_MNT,
 179                 .p_name         = "MOUNT",
 180         },
 181 };
 182
 183 static struct rpc_procinfo mnt3_procedures[] = {
 184         [MOUNTPROC3_MNT] = {
 185                 .p_proc         = MOUNTPROC3_MNT,
 186                 .p_encode       = (kxdrproc_t) xdr_encode_dirpath,
 187                 .p_decode       = (kxdrproc_t) xdr_decode_fhstatus3,
 188                 .p_arglen       = MNT_dirpath_sz,
 189                 .p_replen       = MNT_fhstatus3_sz,
 190                 .p_statidx      = MOUNTPROC3_MNT,
 191                 .p_name         = "MOUNT",
 192         },
 193 };
 194
 195
 196 static struct rpc_version mnt_version1 = {
 197         .number         = 1,
 198         .nrprocs        = 2,
 199         .procs          = mnt_procedures,
 200 };
 201
 202 static struct rpc_version mnt_version3 = {
 203         .number         = 3,
 204         .nrprocs        = 2,
 205         .procs          = mnt3_procedures,
 206 };
 207
 208 static struct rpc_version *mnt_version[] = {
 209         NULL,
 210         &mnt_version1,
 211         NULL,
 212         &mnt_version3,
 213 };
 214
 215 static struct rpc_stat mnt_stats;
 216
 217 static struct rpc_program mnt_program = {
 218         .name           = "mount",
 219         .number         = NFS_MNT_PROGRAM,
 220         .nrvers         = ARRAY_SIZE(mnt_version),
 221         .version        = mnt_version,
 222         .stats          = &mnt_stats,
 223 };