fs/nfs/mount_clnt.c

   1 /*
   2  * linux/fs/nfs/mount_clnt.c
   3  *
   4  * MOUNT client to support NFSroot.
   5  *
   6  * Copyright (C) 1997, Olaf Kirch <okir@monad.swb.de>
   7  */
   8
   9 #include <linux/types.h>
  10 #include <linux/socket.h>
  11 #include <linux/kernel.h>
  12 #include <linux/errno.h>
  13 #include <linux/uio.h>
  14 #include <linux/net.h>
  15 #include <linux/in.h>
  16 #include <linux/sunrpc/clnt.h>
  17 #include <linux/sunrpc/sched.h>
  18 #include <linux/nfs_fs.h>
  19
  20 #ifdef RPC_DEBUG
  21 # define NFSDBG_FACILITY        NFSDBG_ROOT
  22 #endif
  23
  24 /*
  25 #define MOUNT_PROGRAM           100005
  26 #define MOUNT_VERSION           1
  27 #define MOUNT_MNT               1
  28 #define MOUNT_UMNT              3
  29  */
  30
  31 static struct rpc_clnt *        mnt_create(char *, struct sockaddr_in *,
  32                                                                 int, int);
  33 static struct rpc_program       mnt_program;
  34
  35 struct mnt_fhstatus {
  36         unsigned int            status;
  37         struct nfs_fh *         fh;
  38 };
  39
  40 /*
  41  * Obtain an NFS file handle for the given host and path
  42  */
  43 int
  44 nfsroot_mount(struct sockaddr_in *addr, char *path, struct nfs_fh *fh,
  45                 int version, int protocol)
  46 {
  47         struct rpc_clnt         *mnt_clnt;
  48         struct mnt_fhstatus     result = {
  49                 .fh             = fh
  50         };
  51         struct rpc_message msg  = {
  52                 .rpc_argp       = path,
  53                 .rpc_resp       = &result,
  54         };
  55         char                    hostname[32];
  56         int                     status;
  57
  58         dprintk("NFS:      nfs_mount(%08x:%s)\n",
  59                         (unsigned)ntohl(addr->sin_addr.s_addr), path);
  60
  61         sprintf(hostname, "%u.%u.%u.%u", NIPQUAD(addr->sin_addr.s_addr));
  62         mnt_clnt = mnt_create(hostname, addr, version, protocol);
  63         if (IS_ERR(mnt_clnt))
  64                 return PTR_ERR(mnt_clnt);
  65
  66         if (version == NFS_MNT3_VERSION)
  67                 msg.rpc_proc = &mnt_clnt->cl_procinfo[MOUNTPROC3_MNT];
  68         else
  69                 msg.rpc_proc = &mnt_clnt->cl_procinfo[MNTPROC_MNT];
  70
  71         status = rpc_call_sync(mnt_clnt, &msg, 0);
  72         return status < 0? status : (result.status? -EACCES : 0);
  73 }
  74
  75 static struct rpc_clnt *
  76 mnt_create(char *hostname, struct sockaddr_in *srvaddr, int version,
  77                 int protocol)
  78 {
  79         struct rpc_create_args args = {
  80                 .protocol       = protocol,
  81                 .address        = (struct sockaddr *)srvaddr,
  82                 .addrsize       = sizeof(*srvaddr),
  83                 .servername     = hostname,
  84                 .program        = &mnt_program,
  85                 .version        = version,
  86                 .authflavor     = RPC_AUTH_UNIX,
  87                 .flags          = (RPC_CLNT_CREATE_ONESHOT |
  88                                    RPC_CLNT_CREATE_INTR),
  89         };
  90
  91         return rpc_create(&args);
  92 }
  93
  94 /*
  95  * XDR encode/decode functions for MOUNT
  96  */
  97 static int
  98 xdr_encode_dirpath(struct rpc_rqst *req, u32 *p, const char *path)
  99 {
 100         p = xdr_encode_string(p, path);
 101
 102         req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
 103         return 0;
 104 }
 105
 106 static int
 107 xdr_decode_fhstatus(struct rpc_rqst *req, u32 *p, struct mnt_fhstatus *res)
 108 {
 109         struct nfs_fh *fh = res->fh;
 110
 111         if ((res->status = ntohl(*p++)) == 0) {
 112                 fh->size = NFS2_FHSIZE;
 113                 memcpy(fh->data, p, NFS2_FHSIZE);
 114         }
 115         return 0;
 116 }
 117
 118 static int
 119 xdr_decode_fhstatus3(struct rpc_rqst *req, u32 *p, struct mnt_fhstatus *res)
 120 {
 121         struct nfs_fh *fh = res->fh;
 122
 123         if ((res->status = ntohl(*p++)) == 0) {
 124                 int size = ntohl(*p++);
 125                 if (size <= NFS3_FHSIZE) {
 126                         fh->size = size;
 127                         memcpy(fh->data, p, size);
 128                 } else
 129                         res->status = -EBADHANDLE;
 130         }
 131         return 0;
 132 }
 133
 134 #define MNT_dirpath_sz          (1 + 256)
 135 #define MNT_fhstatus_sz         (1 + 8)
 136
 137 static struct rpc_procinfo      mnt_procedures[] = {
 138 [MNTPROC_MNT] = {
 139           .p_proc               = MNTPROC_MNT,
 140           .p_encode             = (kxdrproc_t) xdr_encode_dirpath,
 141           .p_decode             = (kxdrproc_t) xdr_decode_fhstatus,
 142           .p_bufsiz             = MNT_dirpath_sz << 2,
 143           .p_statidx            = MNTPROC_MNT,
 144           .p_name               = "MOUNT",
 145         },
 146 };
 147
 148 static struct rpc_procinfo mnt3_procedures[] = {
 149 [MOUNTPROC3_MNT] = {
 150           .p_proc               = MOUNTPROC3_MNT,
 151           .p_encode             = (kxdrproc_t) xdr_encode_dirpath,
 152           .p_decode             = (kxdrproc_t) xdr_decode_fhstatus3,
 153           .p_bufsiz             = MNT_dirpath_sz << 2,
 154           .p_statidx            = MOUNTPROC3_MNT,
 155           .p_name               = "MOUNT",
 156         },
 157 };
 158
 159
 160 static struct rpc_version       mnt_version1 = {
 161                 .number         = 1,
 162                 .nrprocs        = 2,
 163                 .procs          = mnt_procedures
 164 };
 165
 166 static struct rpc_version       mnt_version3 = {
 167                 .number         = 3,
 168                 .nrprocs        = 2,
 169                 .procs          = mnt3_procedures
 170 };
 171
 172 static struct rpc_version *     mnt_version[] = {
 173         NULL,
 174         &mnt_version1,
 175         NULL,
 176         &mnt_version3,
 177 };
 178
 179 static struct rpc_stat          mnt_stats;
 180
 181 static struct rpc_program       mnt_program = {
 182         .name           = "mount",
 183         .number         = NFS_MNT_PROGRAM,
 184         .nrvers         = ARRAY_SIZE(mnt_version),
 185         .version        = mnt_version,
 186         .stats          = &mnt_stats,
 187 };