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/inet.h>
  17 #include <linux/sunrpc/clnt.h>
  18 #include <linux/sunrpc/xprt.h>
  19 #include <linux/sunrpc/sched.h>
  20 #include <linux/nfs_fs.h>
  21
  22 #ifdef RPC_DEBUG
  23 # define NFSDBG_FACILITY        NFSDBG_ROOT
  24 #endif
  25
  26 /*
  27 #define MOUNT_PROGRAM           100005
  28 #define MOUNT_VERSION           1
  29 #define MOUNT_MNT               1
  30 #define MOUNT_UMNT              3
  31  */
  32
  33 static struct rpc_clnt *        mnt_create(char *, struct sockaddr_in *);
  34 extern struct rpc_program       mnt_program;
  35
  36 struct mnt_fhstatus {
  37         unsigned int            status;
  38         struct nfs_fh *         fh;
  39 };
  40
  41 /*
  42  * Obtain an NFS file handle for the given host and path
  43  */
  44 int
  45 nfs_mount(struct sockaddr_in *addr, char *path, struct nfs_fh *fh)
  46 {
  47         struct rpc_clnt         *mnt_clnt;
  48         struct mnt_fhstatus     result = { 0, fh };
  49         char                    hostname[32];
  50         int                     status;
  51
  52         dprintk("NFS:      nfs_mount(%08x:%s)\n",
  53                         (unsigned)ntohl(addr->sin_addr.s_addr), path);
  54
  55         strcpy(hostname, in_ntoa(addr->sin_addr.s_addr));
  56         if (!(mnt_clnt = mnt_create(hostname, addr)))
  57                 return -EACCES;
  58
  59         status = rpc_call(mnt_clnt, NFS_MNTPROC_MNT, path, &result, 0);
  60         return status < 0? status : (result.status? -EACCES : 0);
  61 }
  62
  63 static struct rpc_clnt *
  64 mnt_create(char *hostname, struct sockaddr_in *srvaddr)
  65 {
  66         struct rpc_xprt *xprt;
  67         struct rpc_clnt *clnt;
  68
  69         if (!(xprt = xprt_create_proto(IPPROTO_UDP, srvaddr, NULL)))
  70                 return NULL;
  71
  72         clnt = rpc_create_client(xprt, hostname,
  73                                 &mnt_program, NFS_MNT_VERSION,
  74                                 RPC_AUTH_NULL);
  75         if (!clnt) {
  76                 xprt_destroy(xprt);
  77         } else {
  78                 clnt->cl_softrtry = 1;
  79                 clnt->cl_chatty   = 1;
  80                 clnt->cl_oneshot  = 1;
  81         }
  82         return clnt;
  83 }
  84
  85 /*
  86  * XDR encode/decode functions for MOUNT
  87  */
  88 static int
  89 xdr_error(struct rpc_rqst *req, u32 *p, void *dummy)
  90 {
  91         return -EIO;
  92 }
  93
  94 static int
  95 xdr_encode_dirpath(struct rpc_rqst *req, u32 *p, const char *path)
  96 {
  97         p = xdr_encode_string(p, path);
  98
  99         req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
 100         return 0;
 101 }
 102
 103 static int
 104 xdr_decode_fhstatus(struct rpc_rqst *req, u32 *p, struct mnt_fhstatus *res)
 105 {
 106         if ((res->status = ntohl(*p++)) == 0)
 107                 memcpy(res->fh, p, sizeof(*res->fh));
 108         return 0;
 109 }
 110
 111 #define MNT_dirpath_sz          (1 + 256)
 112 #define MNT_fhstatus_sz         (1 + 8)
 113
 114 static struct rpc_procinfo      mnt_procedures[2] = {
 115         { "mnt_null",
 116                 (kxdrproc_t) xdr_error,
 117                 (kxdrproc_t) xdr_error, 0, 0 },
 118         { "mnt_mount",
 119                 (kxdrproc_t) xdr_encode_dirpath,
 120                 (kxdrproc_t) xdr_decode_fhstatus,
 121                 MNT_dirpath_sz, MNT_fhstatus_sz },
 122 };
 123
 124 static struct rpc_version       mnt_version1 = {
 125         1, 2, mnt_procedures
 126 };
 127
 128 static struct rpc_version *     mnt_version[] = {
 129         NULL,
 130         &mnt_version1,
 131 };
 132
 133 static struct rpc_stat          mnt_stats;
 134
 135 struct rpc_program      mnt_program = {
 136         "mount",
 137         NFS_MNT_PROGRAM,
 138         sizeof(mnt_version)/sizeof(mnt_version[0]),
 139         mnt_version,
 140         &mnt_stats,
 141 };