fs/9p/trans_fd.c

   1 /*
   2  * linux/fs/9p/trans_fd.c
   3  *
   4  * Fd transport layer.  Includes deprecated socket layer.
   5  *
   6  *  Copyright (C) 2006 by Russ Cox <rsc@swtch.com>
   7  *  Copyright (C) 2004-2005 by Latchesar Ionkov <lucho@ionkov.net>
   8  *  Copyright (C) 2004-2005 by Eric Van Hensbergen <ericvh@gmail.com>
   9  *  Copyright (C) 1997-2002 by Ron Minnich <rminnich@sarnoff.com>
  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 version 2
  13  *  as published by the Free Software Foundation.
  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/in.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 #include <linux/file.h>
  39
  40 #include "debug.h"
  41 #include "v9fs.h"
  42 #include "transport.h"
  43
  44 #define V9FS_PORT 564
  45
  46 struct v9fs_trans_fd {
  47         struct file *rd;
  48         struct file *wr;
  49 };
  50
  51 /**
  52  * v9fs_fd_read- read from a fd
  53  * @v9ses: session information
  54  * @v: buffer to receive data into
  55  * @len: size of receive buffer
  56  *
  57  */
  58 static int v9fs_fd_read(struct v9fs_transport *trans, void *v, int len)
  59 {
  60         int ret;
  61         struct v9fs_trans_fd *ts;
  62
  63         if (!trans || trans->status == Disconnected || !(ts = trans->priv))
  64                 return -EREMOTEIO;
  65
  66         if (!(ts->rd->f_flags & O_NONBLOCK))
  67                 dprintk(DEBUG_ERROR, "blocking read ...\n");
  68
  69         ret = kernel_read(ts->rd, ts->rd->f_pos, v, len);
  70         if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
  71                 trans->status = Disconnected;
  72         return ret;
  73 }
  74
  75 /**
  76  * v9fs_fd_write - write to a socket
  77  * @v9ses: session information
  78  * @v: buffer to send data from
  79  * @len: size of send buffer
  80  *
  81  */
  82 static int v9fs_fd_write(struct v9fs_transport *trans, void *v, int len)
  83 {
  84         int ret;
  85         mm_segment_t oldfs;
  86         struct v9fs_trans_fd *ts;
  87
  88         if (!trans || trans->status == Disconnected || !(ts = trans->priv))
  89                 return -EREMOTEIO;
  90
  91         if (!(ts->wr->f_flags & O_NONBLOCK))
  92                 dprintk(DEBUG_ERROR, "blocking write ...\n");
  93
  94         oldfs = get_fs();
  95         set_fs(get_ds());
  96         /* The cast to a user pointer is valid due to the set_fs() */
  97         ret = vfs_write(ts->wr, (void __user *)v, len, &ts->wr->f_pos);
  98         set_fs(oldfs);
  99
 100         if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
 101                 trans->status = Disconnected;
 102         return ret;
 103 }
 104
 105 static unsigned int
 106 v9fs_fd_poll(struct v9fs_transport *trans, struct poll_table_struct *pt)
 107 {
 108         int ret, n;
 109         struct v9fs_trans_fd *ts;
 110         mm_segment_t oldfs;
 111
 112         if (!trans || trans->status != Connected || !(ts = trans->priv))
 113                 return -EREMOTEIO;
 114
 115         if (!ts->rd->f_op || !ts->rd->f_op->poll)
 116                 return -EIO;
 117
 118         if (!ts->wr->f_op || !ts->wr->f_op->poll)
 119                 return -EIO;
 120
 121         oldfs = get_fs();
 122         set_fs(get_ds());
 123
 124         ret = ts->rd->f_op->poll(ts->rd, pt);
 125         if (ret < 0)
 126                 goto end;
 127
 128         if (ts->rd != ts->wr) {
 129                 n = ts->wr->f_op->poll(ts->wr, pt);
 130                 if (n < 0) {
 131                         ret = n;
 132                         goto end;
 133                 }
 134                 ret = (ret & ~POLLOUT) | (n & ~POLLIN);
 135         }
 136
 137       end:
 138         set_fs(oldfs);
 139         return ret;
 140 }
 141
 142 static int v9fs_fd_open(struct v9fs_session_info *v9ses, int rfd, int wfd)
 143 {
 144         struct v9fs_transport *trans = v9ses->transport;
 145         struct v9fs_trans_fd *ts = kmalloc(sizeof(struct v9fs_trans_fd),
 146                                            GFP_KERNEL);
 147         if (!ts)
 148                 return -ENOMEM;
 149
 150         ts->rd = fget(rfd);
 151         ts->wr = fget(wfd);
 152         if (!ts->rd || !ts->wr) {
 153                 if (ts->rd)
 154                         fput(ts->rd);
 155                 if (ts->wr)
 156                         fput(ts->wr);
 157                 kfree(ts);
 158                 return -EIO;
 159         }
 160
 161         trans->priv = ts;
 162         trans->status = Connected;
 163
 164         return 0;
 165 }
 166
 167 static int v9fs_fd_init(struct v9fs_session_info *v9ses, const char *addr,
 168                         char *data)
 169 {
 170         if (v9ses->rfdno == ~0 || v9ses->wfdno == ~0) {
 171                 printk(KERN_ERR "v9fs: Insufficient options for proto=fd\n");
 172                 return -ENOPROTOOPT;
 173         }
 174
 175         return v9fs_fd_open(v9ses, v9ses->rfdno, v9ses->wfdno);
 176 }
 177
 178 static int v9fs_socket_open(struct v9fs_session_info *v9ses,
 179                             struct socket *csocket)
 180 {
 181         int fd, ret;
 182
 183         csocket->sk->sk_allocation = GFP_NOIO;
 184         if ((fd = sock_map_fd(csocket)) < 0) {
 185                 eprintk(KERN_ERR, "v9fs_socket_open: failed to map fd\n");
 186                 ret = fd;
 187               release_csocket:
 188                 sock_release(csocket);
 189                 return ret;
 190         }
 191
 192         if ((ret = v9fs_fd_open(v9ses, fd, fd)) < 0) {
 193                 sockfd_put(csocket);
 194                 eprintk(KERN_ERR, "v9fs_socket_open: failed to open fd\n");
 195                 goto release_csocket;
 196         }
 197
 198         ((struct v9fs_trans_fd *)v9ses->transport->priv)->rd->f_flags |=
 199             O_NONBLOCK;
 200         return 0;
 201 }
 202
 203 static int v9fs_tcp_init(struct v9fs_session_info *v9ses, const char *addr,
 204                          char *data)
 205 {
 206         int ret;
 207         struct socket *csocket = NULL;
 208         struct sockaddr_in sin_server;
 209
 210         sin_server.sin_family = AF_INET;
 211         sin_server.sin_addr.s_addr = in_aton(addr);
 212         sin_server.sin_port = htons(v9ses->port);
 213         sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &csocket);
 214
 215         if (!csocket) {
 216                 eprintk(KERN_ERR, "v9fs_trans_tcp: problem creating socket\n");
 217                 return -1;
 218         }
 219
 220         ret = csocket->ops->connect(csocket,
 221                                     (struct sockaddr *)&sin_server,
 222                                     sizeof(struct sockaddr_in), 0);
 223         if (ret < 0) {
 224                 eprintk(KERN_ERR,
 225                         "v9fs_trans_tcp: problem connecting socket to %s\n",
 226                         addr);
 227                 return ret;
 228         }
 229
 230         return v9fs_socket_open(v9ses, csocket);
 231 }
 232
 233 static int
 234 v9fs_unix_init(struct v9fs_session_info *v9ses, const char *addr, char *data)
 235 {
 236         int ret;
 237         struct socket *csocket;
 238         struct sockaddr_un sun_server;
 239
 240         if (strlen(addr) > UNIX_PATH_MAX) {
 241                 eprintk(KERN_ERR, "v9fs_trans_unix: address too long: %s\n",
 242                         addr);
 243                 return -ENAMETOOLONG;
 244         }
 245
 246         sun_server.sun_family = PF_UNIX;
 247         strcpy(sun_server.sun_path, addr);
 248         sock_create_kern(PF_UNIX, SOCK_STREAM, 0, &csocket);
 249         ret = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server,
 250                         sizeof(struct sockaddr_un) - 1, 0);
 251         if (ret < 0) {
 252                 eprintk(KERN_ERR,
 253                         "v9fs_trans_unix: problem connecting socket: %s: %d\n",
 254                         addr, ret);
 255                 return ret;
 256         }
 257
 258         return v9fs_socket_open(v9ses, csocket);
 259 }
 260
 261 /**
 262  * v9fs_sock_close - shutdown socket
 263  * @trans: private socket structure
 264  *
 265  */
 266 static void v9fs_fd_close(struct v9fs_transport *trans)
 267 {
 268         struct v9fs_trans_fd *ts;
 269
 270         if (!trans)
 271                 return;
 272
 273         ts = xchg(&trans->priv, NULL);
 274
 275         if (!ts)
 276                 return;
 277
 278         trans->status = Disconnected;
 279         if (ts->rd)
 280                 fput(ts->rd);
 281         if (ts->wr)
 282                 fput(ts->wr);
 283         kfree(ts);
 284 }
 285
 286 struct v9fs_transport v9fs_trans_fd = {
 287         .init = v9fs_fd_init,
 288         .write = v9fs_fd_write,
 289         .read = v9fs_fd_read,
 290         .close = v9fs_fd_close,
 291         .poll = v9fs_fd_poll,
 292 };
 293
 294 struct v9fs_transport v9fs_trans_tcp = {
 295         .init = v9fs_tcp_init,
 296         .write = v9fs_fd_write,
 297         .read = v9fs_fd_read,
 298         .close = v9fs_fd_close,
 299         .poll = v9fs_fd_poll,
 300 };
 301
 302 struct v9fs_transport v9fs_trans_unix = {
 303         .init = v9fs_unix_init,
 304         .write = v9fs_fd_write,
 305         .read = v9fs_fd_read,
 306         .close = v9fs_fd_close,
 307         .poll = v9fs_fd_poll,
 308 };