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         char                    hostname[32];
  53         int                     status;
  54         int                     call;
  55
  56         dprintk("NFS:      nfs_mount(%08x:%s)\n",
  57                         (unsigned)ntohl(addr->sin_addr.s_addr), path);
  58
  59         sprintf(hostname, "%u.%u.%u.%u", NIPQUAD(addr->sin_addr.s_addr));
  60         mnt_clnt = mnt_create(hostname, addr, version, protocol);
  61         if (IS_ERR(mnt_clnt))
  62                 return PTR_ERR(mnt_clnt);
  63
  64         call = (version == NFS_MNT3_VERSION) ? MOUNTPROC3_MNT : MNTPROC_MNT;
  65         status = rpc_call(mnt_clnt, call, path, &result, 0);
  66         return status < 0? status : (result.status? -EACCES : 0);
  67 }
  68
  69 static struct rpc_clnt *
  70 mnt_create(char *hostname, struct sockaddr_in *srvaddr, int version,
  71                 int protocol)
  72 {
  73         struct rpc_xprt *xprt;
  74         struct rpc_clnt *clnt;
  75
  76         xprt = xprt_create_proto(protocol, srvaddr, NULL);
  77         if (IS_ERR(xprt))
  78                 return (struct rpc_clnt *)xprt;
  79
  80         clnt = rpc_create_client(xprt, hostname,
  81                                 &mnt_program, version,
  82                                 RPC_AUTH_UNIX);
  83         if (IS_ERR(clnt)) {
  84                 xprt_destroy(xprt);
  85         } else {
  86                 clnt->cl_softrtry = 1;
  87                 clnt->cl_chatty   = 1;
  88                 clnt->cl_oneshot  = 1;
  89                 clnt->cl_intr = 1;
  90         }
  91         return clnt;
  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         },
 144 };
 145
 146 static struct rpc_procinfo mnt3_procedures[] = {
 147 [MOUNTPROC3_MNT] = {
 148           .p_proc               = MOUNTPROC3_MNT,
 149           .p_encode             = (kxdrproc_t) xdr_encode_dirpath,
 150           .p_decode             = (kxdrproc_t) xdr_decode_fhstatus3,
 151           .p_bufsiz             = MNT_dirpath_sz << 2,
 152         },
 153 };
 154
 155
 156 static struct rpc_version       mnt_version1 = {
 157                 .number         = 1,
 158                 .nrprocs        = 2,
 159                 .procs          = mnt_procedures
 160 };
 161
 162 static struct rpc_version       mnt_version3 = {
 163                 .number         = 3,
 164                 .nrprocs        = 2,
 165                 .procs          = mnt3_procedures
 166 };
 167
 168 static struct rpc_version *     mnt_version[] = {
 169         NULL,
 170         &mnt_version1,
 171         NULL,
 172         &mnt_version3,
 173 };
 174
 175 static struct rpc_stat          mnt_stats;
 176
 177 static struct rpc_program       mnt_program = {
 178         .name           = "mount",
 179         .number         = NFS_MNT_PROGRAM,
 180         .nrvers         = sizeof(mnt_version)/sizeof(mnt_version[0]),
 181         .version        = mnt_version,
 182         .stats          = &mnt_stats,
 183 };