fs/9p/trans_sock.c

   1 /*
   2  * linux/fs/9p/trans_socket.c
   3  *
   4  * Socket Transport Layer
   5  *
   6  *  Copyright (C) 2004-2005 by Latchesar Ionkov <lucho@ionkov.net>
   7  *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
   8  *  Copyright (C) 1997-2002 by Ron Minnich <rminnich@sarnoff.com>
   9  *  Copyright (C) 1995, 1996 by Olaf Kirch <okir@monad.swb.de>
  10  *
  11  *  This program is free software; you can redistribute it and/or modify
  12  *  it under the terms of the GNU General Public License as published by
  13  *  the Free Software Foundation; either version 2 of the License, or
  14  *  (at your option) any later version.
  15  *
  16  *  This program is distributed in the hope that it will be useful,
  17  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  *  GNU General Public License for more details.
  20  *
  21  *  You should have received a copy of the GNU General Public License
  22  *  along with this program; if not, write to:
  23  *  Free Software Foundation
  24  *  51 Franklin Street, Fifth Floor
  25  *  Boston, MA  02111-1301  USA
  26  *
  27  */
  28
  29 #include <linux/config.h>
  30 #include <linux/in.h>
  31 #include <linux/module.h>
  32 #include <linux/net.h>
  33 #include <linux/ipv6.h>
  34 #include <linux/errno.h>
  35 #include <linux/kernel.h>
  36 #include <linux/un.h>
  37 #include <asm/uaccess.h>
  38 #include <linux/inet.h>
  39 #include <linux/idr.h>
  40 #include <linux/file.h>
  41
  42 #include "debug.h"
  43 #include "v9fs.h"
  44 #include "transport.h"
  45
  46 #define V9FS_PORT 564
  47
  48 struct v9fs_trans_sock {
  49         struct socket *s;
  50         struct file *filp;
  51 };
  52
  53 /**
  54  * v9fs_sock_recv - receive from a socket
  55  * @v9ses: session information
  56  * @v: buffer to receive data into
  57  * @len: size of receive buffer
  58  *
  59  */
  60
  61 static int v9fs_sock_recv(struct v9fs_transport *trans, void *v, int len)
  62 {
  63         int ret;
  64         struct v9fs_trans_sock *ts;
  65
  66         if (!trans || trans->status == Disconnected) {
  67                 dprintk(DEBUG_ERROR, "disconnected ...\n");
  68                 return -EREMOTEIO;
  69         }
  70
  71         ts = trans->priv;
  72
  73         if (!(ts->filp->f_flags & O_NONBLOCK))
  74                 dprintk(DEBUG_ERROR, "blocking read ...\n");
  75
  76         ret = kernel_read(ts->filp, ts->filp->f_pos, v, len);
  77         if (ret <= 0) {
  78                 if (ret != -ERESTARTSYS && ret != -EAGAIN)
  79                         trans->status = Disconnected;
  80         }
  81
  82         return ret;
  83 }
  84
  85 /**
  86  * v9fs_sock_send - send to a socket
  87  * @v9ses: session information
  88  * @v: buffer to send data from
  89  * @len: size of send buffer
  90  *
  91  */
  92
  93 static int v9fs_sock_send(struct v9fs_transport *trans, void *v, int len)
  94 {
  95         int ret;
  96         mm_segment_t oldfs;
  97         struct v9fs_trans_sock *ts;
  98
  99         if (!trans || trans->status == Disconnected) {
 100                 dprintk(DEBUG_ERROR, "disconnected ...\n");
 101                 return -EREMOTEIO;
 102         }
 103
 104         ts = trans->priv;
 105         if (!ts) {
 106                 dprintk(DEBUG_ERROR, "no transport ...\n");
 107                 return -EREMOTEIO;
 108         }
 109
 110         if (!(ts->filp->f_flags & O_NONBLOCK))
 111                 dprintk(DEBUG_ERROR, "blocking write ...\n");
 112
 113         oldfs = get_fs();
 114         set_fs(get_ds());
 115         ret = vfs_write(ts->filp, (void __user *)v, len, &ts->filp->f_pos);
 116         set_fs(oldfs);
 117
 118         if (ret < 0) {
 119                 if (ret != -ERESTARTSYS)
 120                         trans->status = Disconnected;
 121         }
 122
 123         return ret;
 124 }
 125
 126 static unsigned int v9fs_sock_poll(struct v9fs_transport *trans,
 127         struct poll_table_struct *pt) {
 128
 129         int ret;
 130         struct v9fs_trans_sock *ts;
 131         mm_segment_t oldfs;
 132
 133         if (!trans) {
 134                 dprintk(DEBUG_ERROR, "no transport\n");
 135                 return -EIO;
 136         }
 137
 138         ts = trans->priv;
 139         if (trans->status != Connected || !ts) {
 140                 dprintk(DEBUG_ERROR, "transport disconnected: %d\n", trans->status);
 141                 return -EIO;
 142         }
 143
 144         oldfs = get_fs();
 145         set_fs(get_ds());
 146
 147         if (!ts->filp->f_op || !ts->filp->f_op->poll) {
 148                 dprintk(DEBUG_ERROR, "no poll operation\n");
 149                 ret = -EIO;
 150                 goto end;
 151         }
 152
 153         ret = ts->filp->f_op->poll(ts->filp, pt);
 154
 155 end:
 156         set_fs(oldfs);
 157         return ret;
 158 }
 159
 160
 161 /**
 162  * v9fs_tcp_init - initialize TCP socket
 163  * @v9ses: session information
 164  * @addr: address of server to mount
 165  * @data: mount options
 166  *
 167  */
 168
 169 static int
 170 v9fs_tcp_init(struct v9fs_session_info *v9ses, const char *addr, char *data)
 171 {
 172         struct socket *csocket = NULL;
 173         struct sockaddr_in sin_server;
 174         int rc = 0;
 175         struct v9fs_trans_sock *ts = NULL;
 176         struct v9fs_transport *trans = v9ses->transport;
 177         int fd;
 178
 179         trans->status = Disconnected;
 180
 181         ts = kmalloc(sizeof(struct v9fs_trans_sock), GFP_KERNEL);
 182
 183         if (!ts)
 184                 return -ENOMEM;
 185
 186         trans->priv = ts;
 187         ts->s = NULL;
 188         ts->filp = NULL;
 189
 190         if (!addr)
 191                 return -EINVAL;
 192
 193         dprintk(DEBUG_TRANS, "Connecting to %s\n", addr);
 194
 195         sin_server.sin_family = AF_INET;
 196         sin_server.sin_addr.s_addr = in_aton(addr);
 197         sin_server.sin_port = htons(v9ses->port);
 198         sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &csocket);
 199         rc = csocket->ops->connect(csocket,
 200                                    (struct sockaddr *)&sin_server,
 201                                    sizeof(struct sockaddr_in), 0);
 202         if (rc < 0) {
 203                 eprintk(KERN_ERR,
 204                         "v9fs_trans_tcp: problem connecting socket to %s\n",
 205                         addr);
 206                 return rc;
 207         }
 208         csocket->sk->sk_allocation = GFP_NOIO;
 209
 210         fd = sock_map_fd(csocket);
 211         if (fd < 0) {
 212                 sock_release(csocket);
 213                 kfree(ts);
 214                 trans->priv = NULL;
 215                 return fd;
 216         }
 217
 218         ts->s = csocket;
 219         ts->filp = fget(fd);
 220         ts->filp->f_flags |= O_NONBLOCK;
 221         trans->status = Connected;
 222
 223         return 0;
 224 }
 225
 226 /**
 227  * v9fs_unix_init - initialize UNIX domain socket
 228  * @v9ses: session information
 229  * @dev_name: path to named pipe
 230  * @data: mount options
 231  *
 232  */
 233
 234 static int
 235 v9fs_unix_init(struct v9fs_session_info *v9ses, const char *dev_name,
 236                char *data)
 237 {
 238         int rc, fd;
 239         struct socket *csocket;
 240         struct sockaddr_un sun_server;
 241         struct v9fs_transport *trans;
 242         struct v9fs_trans_sock *ts;
 243
 244         rc = 0;
 245         csocket = NULL;
 246         trans = v9ses->transport;
 247
 248         trans->status = Disconnected;
 249
 250         if (strlen(dev_name) > UNIX_PATH_MAX) {
 251                 eprintk(KERN_ERR, "v9fs_trans_unix: address too long: %s\n",
 252                         dev_name);
 253                 return -ENOMEM;
 254         }
 255
 256         ts = kmalloc(sizeof(struct v9fs_trans_sock), GFP_KERNEL);
 257         if (!ts)
 258                 return -ENOMEM;
 259
 260         trans->priv = ts;
 261         ts->s = NULL;
 262         ts->filp = NULL;
 263
 264         sun_server.sun_family = PF_UNIX;
 265         strcpy(sun_server.sun_path, dev_name);
 266         sock_create_kern(PF_UNIX, SOCK_STREAM, 0, &csocket);
 267         rc = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server,
 268                 sizeof(struct sockaddr_un) - 1, 0);     /* -1 *is* important */
 269         if (rc < 0) {
 270                 eprintk(KERN_ERR,
 271                         "v9fs_trans_unix: problem connecting socket: %s: %d\n",
 272                         dev_name, rc);
 273                 return rc;
 274         }
 275         csocket->sk->sk_allocation = GFP_NOIO;
 276
 277         fd = sock_map_fd(csocket);
 278         if (fd < 0) {
 279                 sock_release(csocket);
 280                 kfree(ts);
 281                 trans->priv = NULL;
 282                 return fd;
 283         }
 284
 285         ts->s = csocket;
 286         ts->filp = fget(fd);
 287         ts->filp->f_flags |= O_NONBLOCK;
 288         trans->status = Connected;
 289
 290         return 0;
 291 }
 292
 293 /**
 294  * v9fs_sock_close - shutdown socket
 295  * @trans: private socket structure
 296  *
 297  */
 298
 299 static void v9fs_sock_close(struct v9fs_transport *trans)
 300 {
 301         struct v9fs_trans_sock *ts;
 302
 303         if (!trans)
 304                 return;
 305
 306         ts = trans->priv;
 307
 308         if ((ts) && (ts->filp)) {
 309                 fput(ts->filp);
 310                 ts->filp = NULL;
 311                 ts->s = NULL;
 312                 trans->status = Disconnected;
 313         }
 314
 315         kfree(ts);
 316
 317         trans->priv = NULL;
 318 }
 319
 320 struct v9fs_transport v9fs_trans_tcp = {
 321         .init = v9fs_tcp_init,
 322         .write = v9fs_sock_send,
 323         .read = v9fs_sock_recv,
 324         .close = v9fs_sock_close,
 325         .poll = v9fs_sock_poll,
 326 };
 327
 328 struct v9fs_transport v9fs_trans_unix = {
 329         .init = v9fs_unix_init,
 330         .write = v9fs_sock_send,
 331         .read = v9fs_sock_recv,
 332         .close = v9fs_sock_close,
 333         .poll = v9fs_sock_poll,
 334 };