fs/9p/trans_sock.c

   1 /*
   2  * linux/fs/9p/trans_socket.c
   3  *
   4  * Socket Transport Layer
   5  *
   6  *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
   7  *  Copyright (C) 1997-2002 by Ron Minnich <rminnich@sarnoff.com>
   8  *  Copyright (C) 1995, 1996 by Olaf Kirch <okir@monad.swb.de>
   9  *
  10  *  This program is free software; you can redistribute it and/or modify
  11  *  it under the terms of the GNU General Public License as published by
  12  *  the Free Software Foundation; either version 2 of the License, or
  13  *  (at your option) any later version.
  14  *
  15  *  This program is distributed in the hope that it will be useful,
  16  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  *  GNU General Public License for more details.
  19  *
  20  *  You should have received a copy of the GNU General Public License
  21  *  along with this program; if not, write to:
  22  *  Free Software Foundation
  23  *  51 Franklin Street, Fifth Floor
  24  *  Boston, MA  02111-1301  USA
  25  *
  26  */
  27
  28 #include <linux/config.h>
  29 #include <linux/module.h>
  30 #include <linux/net.h>
  31 #include <linux/ipv6.h>
  32 #include <linux/errno.h>
  33 #include <linux/kernel.h>
  34 #include <linux/un.h>
  35 #include <asm/uaccess.h>
  36 #include <linux/inet.h>
  37 #include <linux/idr.h>
  38
  39 #include "debug.h"
  40 #include "v9fs.h"
  41 #include "transport.h"
  42
  43 #define V9FS_PORT 564
  44
  45 struct v9fs_trans_sock {
  46         struct socket *s;
  47 };
  48
  49 /**
  50  * v9fs_sock_recv - receive from a socket
  51  * @v9ses: session information
  52  * @v: buffer to receive data into
  53  * @len: size of receive buffer
  54  *
  55  */
  56
  57 static int v9fs_sock_recv(struct v9fs_transport *trans, void *v, int len)
  58 {
  59         struct msghdr msg;
  60         struct kvec iov;
  61         int result;
  62         mm_segment_t oldfs;
  63         struct v9fs_trans_sock *ts = trans ? trans->priv : NULL;
  64
  65         if (trans->status == Disconnected)
  66                 return -EREMOTEIO;
  67
  68         result = -EINVAL;
  69
  70         oldfs = get_fs();
  71         set_fs(get_ds());
  72
  73         iov.iov_base = v;
  74         iov.iov_len = len;
  75         msg.msg_name = NULL;
  76         msg.msg_namelen = 0;
  77         msg.msg_iovlen = 1;
  78         msg.msg_control = NULL;
  79         msg.msg_controllen = 0;
  80         msg.msg_namelen = 0;
  81         msg.msg_flags = MSG_NOSIGNAL;
  82
  83         result = kernel_recvmsg(ts->s, &msg, &iov, 1, len, 0);
  84
  85         dprintk(DEBUG_TRANS, "socket state %d\n", ts->s->state);
  86         set_fs(oldfs);
  87
  88         if (result <= 0) {
  89                 if (result != -ERESTARTSYS)
  90                         trans->status = Disconnected;
  91         }
  92
  93         return result;
  94 }
  95
  96 /**
  97  * v9fs_sock_send - send to a socket
  98  * @v9ses: session information
  99  * @v: buffer to send data from
 100  * @len: size of send buffer
 101  *
 102  */
 103
 104 static int v9fs_sock_send(struct v9fs_transport *trans, void *v, int len)
 105 {
 106         struct kvec iov;
 107         struct msghdr msg;
 108         int result = -1;
 109         mm_segment_t oldfs;
 110         struct v9fs_trans_sock *ts = trans ? trans->priv : NULL;
 111
 112         dprintk(DEBUG_TRANS, "Sending packet size %d (%x)\n", len, len);
 113         dump_data(v, len);
 114
 115         down(&trans->writelock);
 116
 117         oldfs = get_fs();
 118         set_fs(get_ds());
 119         iov.iov_base = v;
 120         iov.iov_len = len;
 121         msg.msg_name = NULL;
 122         msg.msg_namelen = 0;
 123         msg.msg_iovlen = 1;
 124         msg.msg_control = NULL;
 125         msg.msg_controllen = 0;
 126         msg.msg_namelen = 0;
 127         msg.msg_flags = MSG_NOSIGNAL;
 128         result = kernel_sendmsg(ts->s, &msg, &iov, 1, len);
 129         set_fs(oldfs);
 130
 131         if (result < 0) {
 132                 if (result != -ERESTARTSYS)
 133                         trans->status = Disconnected;
 134         }
 135
 136         up(&trans->writelock);
 137         return result;
 138 }
 139
 140 /**
 141  * v9fs_tcp_init - initialize TCP socket
 142  * @v9ses: session information
 143  * @addr: address of server to mount
 144  * @data: mount options
 145  *
 146  */
 147
 148 static int
 149 v9fs_tcp_init(struct v9fs_session_info *v9ses, const char *addr, char *data)
 150 {
 151         struct socket *csocket = NULL;
 152         struct sockaddr_in sin_server;
 153         int rc = 0;
 154         struct v9fs_trans_sock *ts = NULL;
 155         struct v9fs_transport *trans = v9ses->transport;
 156
 157         sema_init(&trans->writelock, 1);
 158         sema_init(&trans->readlock, 1);
 159
 160         ts = kmalloc(sizeof(struct v9fs_trans_sock), GFP_KERNEL);
 161
 162         if (!ts)
 163                 return -ENOMEM;
 164
 165         trans->priv = ts;
 166         ts->s = NULL;
 167
 168         if (!addr)
 169                 return -EINVAL;
 170
 171         dprintk(DEBUG_TRANS, "Connecting to %s\n", addr);
 172
 173         sin_server.sin_family = AF_INET;
 174         sin_server.sin_addr.s_addr = in_aton(addr);
 175         sin_server.sin_port = htons(v9ses->port);
 176         sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &csocket);
 177         rc = csocket->ops->connect(csocket,
 178                                    (struct sockaddr *)&sin_server,
 179                                    sizeof(struct sockaddr_in), 0);
 180         if (rc < 0) {
 181                 eprintk(KERN_ERR,
 182                         "v9fs_trans_tcp: problem connecting socket to %s\n",
 183                         addr);
 184                 return rc;
 185         }
 186         csocket->sk->sk_allocation = GFP_NOIO;
 187         ts->s = csocket;
 188         trans->status = Connected;
 189
 190         return 0;
 191 }
 192
 193 /**
 194  * v9fs_unix_init - initialize UNIX domain socket
 195  * @v9ses: session information
 196  * @dev_name: path to named pipe
 197  * @data: mount options
 198  *
 199  */
 200
 201 static int
 202 v9fs_unix_init(struct v9fs_session_info *v9ses, const char *dev_name,
 203                char *data)
 204 {
 205         int rc;
 206         struct socket *csocket;
 207         struct sockaddr_un sun_server;
 208         struct v9fs_transport *trans;
 209         struct v9fs_trans_sock *ts;
 210
 211         rc = 0;
 212         csocket = NULL;
 213         trans = v9ses->transport;
 214
 215         if (strlen(dev_name) > UNIX_PATH_MAX) {
 216                 eprintk(KERN_ERR, "v9fs_trans_unix: address too long: %s\n",
 217                         dev_name);
 218                 return -ENOMEM;
 219         }
 220
 221         ts = kmalloc(sizeof(struct v9fs_trans_sock), GFP_KERNEL);
 222         if (!ts)
 223                 return -ENOMEM;
 224
 225         trans->priv = ts;
 226         ts->s = NULL;
 227
 228         sema_init(&trans->writelock, 1);
 229         sema_init(&trans->readlock, 1);
 230
 231         sun_server.sun_family = PF_UNIX;
 232         strcpy(sun_server.sun_path, dev_name);
 233         sock_create_kern(PF_UNIX, SOCK_STREAM, 0, &csocket);
 234         rc = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server,
 235                 sizeof(struct sockaddr_un) - 1, 0);     /* -1 *is* important */
 236         if (rc < 0) {
 237                 eprintk(KERN_ERR,
 238                         "v9fs_trans_unix: problem connecting socket: %s: %d\n",
 239                         dev_name, rc);
 240                 return rc;
 241         }
 242         csocket->sk->sk_allocation = GFP_NOIO;
 243         ts->s = csocket;
 244         trans->status = Connected;
 245
 246         return 0;
 247 }
 248
 249 /**
 250  * v9fs_sock_close - shutdown socket
 251  * @trans: private socket structure
 252  *
 253  */
 254
 255 static void v9fs_sock_close(struct v9fs_transport *trans)
 256 {
 257         struct v9fs_trans_sock *ts;
 258
 259         if (!trans)
 260                 return;
 261
 262         ts = trans->priv;
 263
 264         if ((ts) && (ts->s)) {
 265                 dprintk(DEBUG_TRANS, "closing the socket %p\n", ts->s);
 266                 sock_release(ts->s);
 267                 ts->s = NULL;
 268                 trans->status = Disconnected;
 269                 dprintk(DEBUG_TRANS, "socket closed\n");
 270         }
 271
 272         kfree(ts);
 273
 274         trans->priv = NULL;
 275 }
 276
 277 struct v9fs_transport v9fs_trans_tcp = {
 278         .init = v9fs_tcp_init,
 279         .write = v9fs_sock_send,
 280         .read = v9fs_sock_recv,
 281         .close = v9fs_sock_close,
 282 };
 283
 284 struct v9fs_transport v9fs_trans_unix = {
 285         .init = v9fs_unix_init,
 286         .write = v9fs_sock_send,
 287         .read = v9fs_sock_recv,
 288         .close = v9fs_sock_close,
 289 };