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
  18 #ifdef RPC_DEBUG
  19 # define NFSDBG_FACILITY        NFSDBG_MOUNT
  20 #endif
  21
  22 static struct rpc_program       mnt_program;
  23
  24 struct mnt_fhstatus {
  25         u32 status;
  26         struct nfs_fh *fh;
  27 };
  28
  29 /**
  30  * nfs_mount - Obtain an NFS file handle for the given host and path
  31  * @addr: pointer to server's address
  32  * @len: size of server's address
  33  * @hostname: name of server host, or NULL
  34  * @path: pointer to string containing export path to mount
  35  * @version: mount version to use for this request
  36  * @protocol: transport protocol to use for thie request
  37  * @fh: pointer to location to place returned file handle
  38  *
  39  * Uses default timeout parameters specified by underlying transport.
  40  */
  41 int nfs_mount(struct sockaddr *addr, size_t len, char *hostname, char *path,
  42               int version, int protocol, struct nfs_fh *fh)
  43 {
  44         struct mnt_fhstatus     result = {
  45                 .fh             = fh
  46         };
  47         struct rpc_message msg  = {
  48                 .rpc_argp       = path,
  49                 .rpc_resp       = &result,
  50         };
  51         struct rpc_create_args args = {
  52                 .protocol       = protocol,
  53                 .address        = addr,
  54                 .addrsize       = len,
  55                 .servername     = hostname,
  56                 .program        = &mnt_program,
  57                 .version        = version,
  58                 .authflavor     = RPC_AUTH_UNIX,
  59                 .flags          = 0,
  60         };
  61         struct rpc_clnt         *mnt_clnt;
  62         int                     status;
  63
  64         dprintk("NFS: sending MNT request for %s:%s\n",
  65                 (hostname ? hostname : "server"), path);
  66
  67         mnt_clnt = rpc_create(&args);
  68         if (IS_ERR(mnt_clnt))
  69                 goto out_clnt_err;
  70
  71         if (version == NFS_MNT3_VERSION)
  72                 msg.rpc_proc = &mnt_clnt->cl_procinfo[MOUNTPROC3_MNT];
  73         else
  74                 msg.rpc_proc = &mnt_clnt->cl_procinfo[MNTPROC_MNT];
  75
  76         status = rpc_call_sync(mnt_clnt, &msg, 0);
  77         rpc_shutdown_client(mnt_clnt);
  78
  79         if (status < 0)
  80                 goto out_call_err;
  81         if (result.status != 0)
  82                 goto out_mnt_err;
  83
  84         dprintk("NFS: MNT request succeeded\n");
  85         status = 0;
  86
  87 out:
  88         return status;
  89
  90 out_clnt_err:
  91         status = PTR_ERR(mnt_clnt);
  92         dprintk("NFS: failed to create RPC client, status=%d\n", status);
  93         goto out;
  94
  95 out_call_err:
  96         dprintk("NFS: failed to start MNT request, status=%d\n", status);
  97         goto out;
  98
  99 out_mnt_err:
 100         dprintk("NFS: MNT server returned result %d\n", result.status);
 101         status = -EACCES;
 102         goto out;
 103 }
 104
 105 /*
 106  * XDR encode/decode functions for MOUNT
 107  */
 108 static int xdr_encode_dirpath(struct rpc_rqst *req, __be32 *p,
 109                               const char *path)
 110 {
 111         p = xdr_encode_string(p, path);
 112
 113         req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
 114         return 0;
 115 }
 116
 117 static int xdr_decode_fhstatus(struct rpc_rqst *req, __be32 *p,
 118                                struct mnt_fhstatus *res)
 119 {
 120         struct nfs_fh *fh = res->fh;
 121
 122         if ((res->status = ntohl(*p++)) == 0) {
 123                 fh->size = NFS2_FHSIZE;
 124                 memcpy(fh->data, p, NFS2_FHSIZE);
 125         }
 126         return 0;
 127 }
 128
 129 static int xdr_decode_fhstatus3(struct rpc_rqst *req, __be32 *p,
 130                                 struct mnt_fhstatus *res)
 131 {
 132         struct nfs_fh *fh = res->fh;
 133
 134         if ((res->status = ntohl(*p++)) == 0) {
 135                 int size = ntohl(*p++);
 136                 if (size <= NFS3_FHSIZE) {
 137                         fh->size = size;
 138                         memcpy(fh->data, p, size);
 139                 } else
 140                         res->status = -EBADHANDLE;
 141         }
 142         return 0;
 143 }
 144
 145 #define MNT_dirpath_sz          (1 + 256)
 146 #define MNT_fhstatus_sz         (1 + 8)
 147 #define MNT_fhstatus3_sz        (1 + 16)
 148
 149 static struct rpc_procinfo mnt_procedures[] = {
 150         [MNTPROC_MNT] = {
 151                 .p_proc         = MNTPROC_MNT,
 152                 .p_encode       = (kxdrproc_t) xdr_encode_dirpath,
 153                 .p_decode       = (kxdrproc_t) xdr_decode_fhstatus,
 154                 .p_arglen       = MNT_dirpath_sz,
 155                 .p_replen       = MNT_fhstatus_sz,
 156                 .p_statidx      = MNTPROC_MNT,
 157                 .p_name         = "MOUNT",
 158         },
 159 };
 160
 161 static struct rpc_procinfo mnt3_procedures[] = {
 162         [MOUNTPROC3_MNT] = {
 163                 .p_proc         = MOUNTPROC3_MNT,
 164                 .p_encode       = (kxdrproc_t) xdr_encode_dirpath,
 165                 .p_decode       = (kxdrproc_t) xdr_decode_fhstatus3,
 166                 .p_arglen       = MNT_dirpath_sz,
 167                 .p_replen       = MNT_fhstatus3_sz,
 168                 .p_statidx      = MOUNTPROC3_MNT,
 169                 .p_name         = "MOUNT",
 170         },
 171 };
 172
 173
 174 static struct rpc_version mnt_version1 = {
 175         .number         = 1,
 176         .nrprocs        = 2,
 177         .procs          = mnt_procedures,
 178 };
 179
 180 static struct rpc_version mnt_version3 = {
 181         .number         = 3,
 182         .nrprocs        = 2,
 183         .procs          = mnt3_procedures,
 184 };
 185
 186 static struct rpc_version *mnt_version[] = {
 187         NULL,
 188         &mnt_version1,
 189         NULL,
 190         &mnt_version3,
 191 };
 192
 193 static struct rpc_stat mnt_stats;
 194
 195 static struct rpc_program mnt_program = {
 196         .name           = "mount",
 197         .number         = NFS_MNT_PROGRAM,
 198         .nrvers         = ARRAY_SIZE(mnt_version),
 199         .version        = mnt_version,
 200         .stats          = &mnt_stats,
 201 };