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/xprt.h>
  18 #include <linux/sunrpc/sched.h>
  19 #include <linux/nfs_fs.h>
  20
  21 #ifdef RPC_DEBUG
  22 # define NFSDBG_FACILITY        NFSDBG_ROOT
  23 #endif
  24
  25 /*
  26 #define MOUNT_PROGRAM           100005
  27 #define MOUNT_VERSION           1
  28 #define MOUNT_MNT               1
  29 #define MOUNT_UMNT              3
  30  */
  31
  32 static struct rpc_clnt *        mnt_create(char *, struct sockaddr_in *,
  33                                                                 int, int);
  34 static 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 nfsroot_mount(struct sockaddr_in *addr, char *path, struct nfs_fh *fh,
  46                 int version, int protocol)
  47 {
  48         struct rpc_clnt         *mnt_clnt;
  49         struct mnt_fhstatus     result = {
  50                 .fh             = fh
  51         };
  52         struct rpc_message msg  = {
  53                 .rpc_argp       = path,
  54                 .rpc_resp       = &result,
  55         };
  56         char                    hostname[32];
  57         int                     status;
  58
  59         dprintk("NFS:      nfs_mount(%08x:%s)\n",
  60                         (unsigned)ntohl(addr->sin_addr.s_addr), path);
  61
  62         sprintf(hostname, "%u.%u.%u.%u", NIPQUAD(addr->sin_addr.s_addr));
  63         mnt_clnt = mnt_create(hostname, addr, version, protocol);
  64         if (IS_ERR(mnt_clnt))
  65                 return PTR_ERR(mnt_clnt);
  66
  67         if (version == NFS_MNT3_VERSION)
  68                 msg.rpc_proc = &mnt_clnt->cl_procinfo[MOUNTPROC3_MNT];
  69         else
  70                 msg.rpc_proc = &mnt_clnt->cl_procinfo[MNTPROC_MNT];
  71
  72         status = rpc_call_sync(mnt_clnt, &msg, 0);
  73         return status < 0? status : (result.status? -EACCES : 0);
  74 }
  75
  76 static struct rpc_clnt *
  77 mnt_create(char *hostname, struct sockaddr_in *srvaddr, int version,
  78                 int protocol)
  79 {
  80         struct rpc_xprt *xprt;
  81         struct rpc_clnt *clnt;
  82
  83         xprt = xprt_create_proto(protocol, srvaddr, NULL);
  84         if (IS_ERR(xprt))
  85                 return (struct rpc_clnt *)xprt;
  86
  87         clnt = rpc_create_client(xprt, hostname,
  88                                 &mnt_program, version,
  89                                 RPC_AUTH_UNIX);
  90         if (!IS_ERR(clnt)) {
  91                 clnt->cl_softrtry = 1;
  92                 clnt->cl_oneshot  = 1;
  93                 clnt->cl_intr = 1;
  94         }
  95         return clnt;
  96 }
  97
  98 /*
  99  * XDR encode/decode functions for MOUNT
 100  */
 101 static int
 102 xdr_encode_dirpath(struct rpc_rqst *req, u32 *p, const char *path)
 103 {
 104         p = xdr_encode_string(p, path);
 105
 106         req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
 107         return 0;
 108 }
 109
 110 static int
 111 xdr_decode_fhstatus(struct rpc_rqst *req, u32 *p, struct mnt_fhstatus *res)
 112 {
 113         struct nfs_fh *fh = res->fh;
 114
 115         if ((res->status = ntohl(*p++)) == 0) {
 116                 fh->size = NFS2_FHSIZE;
 117                 memcpy(fh->data, p, NFS2_FHSIZE);
 118         }
 119         return 0;
 120 }
 121
 122 static int
 123 xdr_decode_fhstatus3(struct rpc_rqst *req, u32 *p, struct mnt_fhstatus *res)
 124 {
 125         struct nfs_fh *fh = res->fh;
 126
 127         if ((res->status = ntohl(*p++)) == 0) {
 128                 int size = ntohl(*p++);
 129                 if (size <= NFS3_FHSIZE) {
 130                         fh->size = size;
 131                         memcpy(fh->data, p, size);
 132                 } else
 133                         res->status = -EBADHANDLE;
 134         }
 135         return 0;
 136 }
 137
 138 #define MNT_dirpath_sz          (1 + 256)
 139 #define MNT_fhstatus_sz         (1 + 8)
 140
 141 static struct rpc_procinfo      mnt_procedures[] = {
 142 [MNTPROC_MNT] = {
 143           .p_proc               = MNTPROC_MNT,
 144           .p_encode             = (kxdrproc_t) xdr_encode_dirpath,
 145           .p_decode             = (kxdrproc_t) xdr_decode_fhstatus,
 146           .p_bufsiz             = MNT_dirpath_sz << 2,
 147           .p_statidx            = MNTPROC_MNT,
 148           .p_name               = "MOUNT",
 149         },
 150 };
 151
 152 static struct rpc_procinfo mnt3_procedures[] = {
 153 [MOUNTPROC3_MNT] = {
 154           .p_proc               = MOUNTPROC3_MNT,
 155           .p_encode             = (kxdrproc_t) xdr_encode_dirpath,
 156           .p_decode             = (kxdrproc_t) xdr_decode_fhstatus3,
 157           .p_bufsiz             = MNT_dirpath_sz << 2,
 158           .p_statidx            = MOUNTPROC3_MNT,
 159           .p_name               = "MOUNT",
 160         },
 161 };
 162
 163
 164 static struct rpc_version       mnt_version1 = {
 165                 .number         = 1,
 166                 .nrprocs        = 2,
 167                 .procs          = mnt_procedures
 168 };
 169
 170 static struct rpc_version       mnt_version3 = {
 171                 .number         = 3,
 172                 .nrprocs        = 2,
 173                 .procs          = mnt3_procedures
 174 };
 175
 176 static struct rpc_version *     mnt_version[] = {
 177         NULL,
 178         &mnt_version1,
 179         NULL,
 180         &mnt_version3,
 181 };
 182
 183 static struct rpc_stat          mnt_stats;
 184
 185 static struct rpc_program       mnt_program = {
 186         .name           = "mount",
 187         .number         = NFS_MNT_PROGRAM,
 188         .nrvers         = ARRAY_SIZE(mnt_version),
 189         .version        = mnt_version,
 190         .stats          = &mnt_stats,
 191 };