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(struct sockaddr_in *, int, int);
  32 static struct rpc_program       mnt_program;
  33
  34 struct mnt_fhstatus {
  35         unsigned int            status;
  36         struct nfs_fh *         fh;
  37 };
  38
  39 /*
  40  * Obtain an NFS file handle for the given host and path
  41  */
  42 int
  43 nfsroot_mount(struct sockaddr_in *addr, char *path, struct nfs_fh *fh,
  44                 int version, int protocol)
  45 {
  46         struct rpc_clnt         *mnt_clnt;
  47         struct mnt_fhstatus     result = {
  48                 .fh             = fh
  49         };
  50         struct rpc_message msg  = {
  51                 .rpc_argp       = path,
  52                 .rpc_resp       = &result,
  53         };
  54         int                     status;
  55
  56         dprintk("NFS:      nfs_mount(%08x:%s)\n",
  57                         (unsigned)ntohl(addr->sin_addr.s_addr), path);
  58
  59         mnt_clnt = mnt_create(addr, version, protocol);
  60         if (IS_ERR(mnt_clnt))
  61                 return PTR_ERR(mnt_clnt);
  62
  63         if (version == NFS_MNT3_VERSION)
  64                 msg.rpc_proc = &mnt_clnt->cl_procinfo[MOUNTPROC3_MNT];
  65         else
  66                 msg.rpc_proc = &mnt_clnt->cl_procinfo[MNTPROC_MNT];
  67
  68         status = rpc_call_sync(mnt_clnt, &msg, 0);
  69         rpc_shutdown_client(mnt_clnt);
  70         return status < 0? status : (result.status? -EACCES : 0);
  71 }
  72
  73 static struct rpc_clnt *mnt_create(struct sockaddr_in *srvaddr, int version,
  74                                    int protocol)
  75 {
  76         struct rpc_create_args args = {
  77                 .protocol       = protocol,
  78                 .address        = (struct sockaddr *)srvaddr,
  79                 .addrsize       = sizeof(*srvaddr),
  80                 .program        = &mnt_program,
  81                 .version        = version,
  82                 .authflavor     = RPC_AUTH_UNIX,
  83                 .flags          = RPC_CLNT_CREATE_INTR,
  84         };
  85
  86         return rpc_create(&args);
  87 }
  88
  89 /*
  90  * XDR encode/decode functions for MOUNT
  91  */
  92 static int
  93 xdr_encode_dirpath(struct rpc_rqst *req, __be32 *p, const char *path)
  94 {
  95         p = xdr_encode_string(p, path);
  96
  97         req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
  98         return 0;
  99 }
 100
 101 static int
 102 xdr_decode_fhstatus(struct rpc_rqst *req, __be32 *p, struct mnt_fhstatus *res)
 103 {
 104         struct nfs_fh *fh = res->fh;
 105
 106         if ((res->status = ntohl(*p++)) == 0) {
 107                 fh->size = NFS2_FHSIZE;
 108                 memcpy(fh->data, p, NFS2_FHSIZE);
 109         }
 110         return 0;
 111 }
 112
 113 static int
 114 xdr_decode_fhstatus3(struct rpc_rqst *req, __be32 *p, struct mnt_fhstatus *res)
 115 {
 116         struct nfs_fh *fh = res->fh;
 117
 118         if ((res->status = ntohl(*p++)) == 0) {
 119                 int size = ntohl(*p++);
 120                 if (size <= NFS3_FHSIZE) {
 121                         fh->size = size;
 122                         memcpy(fh->data, p, size);
 123                 } else
 124                         res->status = -EBADHANDLE;
 125         }
 126         return 0;
 127 }
 128
 129 #define MNT_dirpath_sz          (1 + 256)
 130 #define MNT_fhstatus_sz         (1 + 8)
 131 #define MNT_fhstatus3_sz        (1 + 16)
 132
 133 static struct rpc_procinfo      mnt_procedures[] = {
 134 [MNTPROC_MNT] = {
 135           .p_proc               = MNTPROC_MNT,
 136           .p_encode             = (kxdrproc_t) xdr_encode_dirpath,
 137           .p_decode             = (kxdrproc_t) xdr_decode_fhstatus,
 138           .p_arglen             = MNT_dirpath_sz,
 139           .p_replen             = MNT_fhstatus_sz,
 140           .p_statidx            = MNTPROC_MNT,
 141           .p_name               = "MOUNT",
 142         },
 143 };
 144
 145 static struct rpc_procinfo mnt3_procedures[] = {
 146 [MOUNTPROC3_MNT] = {
 147           .p_proc               = MOUNTPROC3_MNT,
 148           .p_encode             = (kxdrproc_t) xdr_encode_dirpath,
 149           .p_decode             = (kxdrproc_t) xdr_decode_fhstatus3,
 150           .p_arglen             = MNT_dirpath_sz,
 151           .p_replen             = MNT_fhstatus3_sz,
 152           .p_statidx            = MOUNTPROC3_MNT,
 153           .p_name               = "MOUNT",
 154         },
 155 };
 156
 157
 158 static struct rpc_version       mnt_version1 = {
 159                 .number         = 1,
 160                 .nrprocs        = 2,
 161                 .procs          = mnt_procedures
 162 };
 163
 164 static struct rpc_version       mnt_version3 = {
 165                 .number         = 3,
 166                 .nrprocs        = 2,
 167                 .procs          = mnt3_procedures
 168 };
 169
 170 static struct rpc_version *     mnt_version[] = {
 171         NULL,
 172         &mnt_version1,
 173         NULL,
 174         &mnt_version3,
 175 };
 176
 177 static struct rpc_stat          mnt_stats;
 178
 179 static struct rpc_program       mnt_program = {
 180         .name           = "mount",
 181         .number         = NFS_MNT_PROGRAM,
 182         .nrvers         = ARRAY_SIZE(mnt_version),
 183         .version        = mnt_version,
 184         .stats          = &mnt_stats,
 185 };