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 static struct rpc_program       mnt_program;
  24
  25 struct mnt_fhstatus {
  26         u32 status;
  27         struct nfs_fh *fh;
  28 };
  29
  30 /**
  31  * nfs_mount - Obtain an NFS file handle for the given host and path
  32  * @info: pointer to mount request arguments
  33  *
  34  * Uses default timeout parameters specified by underlying transport.
  35  */
  36 int nfs_mount(struct nfs_mount_request *info)
  37 {
  38         struct mnt_fhstatus     result = {
  39                 .fh             = info->fh
  40         };
  41         struct rpc_message msg  = {
  42                 .rpc_argp       = info->dirpath,
  43                 .rpc_resp       = &result,
  44         };
  45         struct rpc_create_args args = {
  46                 .protocol       = info->protocol,
  47                 .address        = info->sap,
  48                 .addrsize       = info->salen,
  49                 .servername     = info->hostname,
  50                 .program        = &mnt_program,
  51                 .version        = info->version,
  52                 .authflavor     = RPC_AUTH_UNIX,
  53         };
  54         struct rpc_clnt         *mnt_clnt;
  55         int                     status;
  56
  57         dprintk("NFS: sending MNT request for %s:%s\n",
  58                 (info->hostname ? info->hostname : "server"),
  59                         info->dirpath);
  60
  61         if (info->noresvport)
  62                 args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
  63
  64         mnt_clnt = rpc_create(&args);
  65         if (IS_ERR(mnt_clnt))
  66                 goto out_clnt_err;
  67
  68         if (info->version == NFS_MNT3_VERSION)
  69                 msg.rpc_proc = &mnt_clnt->cl_procinfo[MOUNTPROC3_MNT];
  70         else
  71                 msg.rpc_proc = &mnt_clnt->cl_procinfo[MNTPROC_MNT];
  72
  73         status = rpc_call_sync(mnt_clnt, &msg, 0);
  74         rpc_shutdown_client(mnt_clnt);
  75
  76         if (status < 0)
  77                 goto out_call_err;
  78         if (result.status != 0)
  79                 goto out_mnt_err;
  80
  81         dprintk("NFS: MNT request succeeded\n");
  82         status = 0;
  83
  84 out:
  85         return status;
  86
  87 out_clnt_err:
  88         status = PTR_ERR(mnt_clnt);
  89         dprintk("NFS: failed to create RPC client, status=%d\n", status);
  90         goto out;
  91
  92 out_call_err:
  93         dprintk("NFS: failed to start MNT request, status=%d\n", status);
  94         goto out;
  95
  96 out_mnt_err:
  97         dprintk("NFS: MNT server returned result %d\n", result.status);
  98         status = nfs_stat_to_errno(result.status);
  99         goto out;
 100 }
 101
 102 /*
 103  * XDR encode/decode functions for MOUNT
 104  */
 105 static int xdr_encode_dirpath(struct rpc_rqst *req, __be32 *p,
 106                               const char *path)
 107 {
 108         p = xdr_encode_string(p, path);
 109
 110         req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
 111         return 0;
 112 }
 113
 114 static int xdr_decode_fhstatus(struct rpc_rqst *req, __be32 *p,
 115                                struct mnt_fhstatus *res)
 116 {
 117         struct nfs_fh *fh = res->fh;
 118
 119         if ((res->status = ntohl(*p++)) == 0) {
 120                 fh->size = NFS2_FHSIZE;
 121                 memcpy(fh->data, p, NFS2_FHSIZE);
 122         }
 123         return 0;
 124 }
 125
 126 static int xdr_decode_fhstatus3(struct rpc_rqst *req, __be32 *p,
 127                                 struct mnt_fhstatus *res)
 128 {
 129         struct nfs_fh *fh = res->fh;
 130         unsigned size;
 131
 132         if ((res->status = ntohl(*p++)) == 0) {
 133                 size = ntohl(*p++);
 134                 if (size <= NFS3_FHSIZE && size != 0) {
 135                         fh->size = size;
 136                         memcpy(fh->data, p, size);
 137                 } else
 138                         res->status = -EBADHANDLE;
 139         }
 140         return 0;
 141 }
 142
 143 #define MNT_dirpath_sz          (1 + 256)
 144 #define MNT_fhstatus_sz         (1 + 8)
 145 #define MNT_fhstatus3_sz        (1 + 16)
 146
 147 static struct rpc_procinfo mnt_procedures[] = {
 148         [MNTPROC_MNT] = {
 149                 .p_proc         = MNTPROC_MNT,
 150                 .p_encode       = (kxdrproc_t) xdr_encode_dirpath,
 151                 .p_decode       = (kxdrproc_t) xdr_decode_fhstatus,
 152                 .p_arglen       = MNT_dirpath_sz,
 153                 .p_replen       = MNT_fhstatus_sz,
 154                 .p_statidx      = MNTPROC_MNT,
 155                 .p_name         = "MOUNT",
 156         },
 157 };
 158
 159 static struct rpc_procinfo mnt3_procedures[] = {
 160         [MOUNTPROC3_MNT] = {
 161                 .p_proc         = MOUNTPROC3_MNT,
 162                 .p_encode       = (kxdrproc_t) xdr_encode_dirpath,
 163                 .p_decode       = (kxdrproc_t) xdr_decode_fhstatus3,
 164                 .p_arglen       = MNT_dirpath_sz,
 165                 .p_replen       = MNT_fhstatus3_sz,
 166                 .p_statidx      = MOUNTPROC3_MNT,
 167                 .p_name         = "MOUNT",
 168         },
 169 };
 170
 171
 172 static struct rpc_version mnt_version1 = {
 173         .number         = 1,
 174         .nrprocs        = 2,
 175         .procs          = mnt_procedures,
 176 };
 177
 178 static struct rpc_version mnt_version3 = {
 179         .number         = 3,
 180         .nrprocs        = 2,
 181         .procs          = mnt3_procedures,
 182 };
 183
 184 static struct rpc_version *mnt_version[] = {
 185         NULL,
 186         &mnt_version1,
 187         NULL,
 188         &mnt_version3,
 189 };
 190
 191 static struct rpc_stat mnt_stats;
 192
 193 static struct rpc_program mnt_program = {
 194         .name           = "mount",
 195         .number         = NFS_MNT_PROGRAM,
 196         .nrvers         = ARRAY_SIZE(mnt_version),
 197         .version        = mnt_version,
 198         .stats          = &mnt_stats,
 199 };