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   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  *  Copyright (C) 1995, 1996 by Olaf Kirch <okir@monad.swb.de>
  11  *
  12  *  This program is free software; you can redistribute it and/or modify
  13  *  it under the terms of the GNU General Public License as published by
  14  *  the Free Software Foundation; either version 2 of the License, or
  15  *  (at your option) any later version.
  16  *
  17  *  This program is distributed in the hope that it will be useful,
  18  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  *  GNU General Public License for more details.
  21  *
  22  *  You should have received a copy of the GNU General Public License
  23  *  along with this program; if not, write to:
  24  *  Free Software Foundation
  25  *  51 Franklin Street, Fifth Floor
  26  *  Boston, MA  02111-1301  USA
  27  *
  28  */
  29
  30 #include <linux/config.h>
  31 #include <linux/in.h>
  32 #include <linux/module.h>
  33 #include <linux/net.h>
  34 #include <linux/ipv6.h>
  35 #include <linux/errno.h>
  36 #include <linux/kernel.h>
  37 #include <linux/un.h>
  38 #include <asm/uaccess.h>
  39 #include <linux/inet.h>
  40 #include <linux/idr.h>
  41 #include <linux/file.h>
  42
  43 #include "debug.h"
  44 #include "v9fs.h"
  45 #include "transport.h"
  46
  47 #define V9FS_PORT 564
  48
  49 struct v9fs_trans_fd {
  50         struct file *rd;
  51         struct file *wr;
  52 };
  53
  54 /**
  55  * v9fs_fd_read- read from a fd
  56  * @v9ses: session information
  57  * @v: buffer to receive data into
  58  * @len: size of receive buffer
  59  *
  60  */
  61 static int v9fs_fd_read(struct v9fs_transport *trans, void *v, int len)
  62 {
  63         int ret;
  64         struct v9fs_trans_fd *ts;
  65
  66         if (!trans || trans->status == Disconnected || !(ts = trans->priv))
  67                 return -EREMOTEIO;
  68
  69         if (!(ts->rd->f_flags & O_NONBLOCK))
  70                 dprintk(DEBUG_ERROR, "blocking read ...\n");
  71
  72         ret = kernel_read(ts->rd, ts->rd->f_pos, v, len);
  73         if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
  74                 trans->status = Disconnected;
  75         return ret;
  76 }
  77
  78 /**
  79  * v9fs_fd_write - write to a socket
  80  * @v9ses: session information
  81  * @v: buffer to send data from
  82  * @len: size of send buffer
  83  *
  84  */
  85 static int v9fs_fd_write(struct v9fs_transport *trans, void *v, int len)
  86 {
  87         int ret;
  88         mm_segment_t oldfs;
  89         struct v9fs_trans_fd *ts;
  90
  91         if (!trans || trans->status == Disconnected || !(ts = trans->priv))
  92                 return -EREMOTEIO;
  93
  94         if (!(ts->wr->f_flags & O_NONBLOCK))
  95                 dprintk(DEBUG_ERROR, "blocking write ...\n");
  96
  97         oldfs = get_fs();
  98         set_fs(get_ds());
  99         /* The cast to a user pointer is valid due to the set_fs() */
 100         ret = vfs_write(ts->wr, (void __user *)v, len, &ts->wr->f_pos);
 101         set_fs(oldfs);
 102
 103         if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
 104                 trans->status = Disconnected;
 105         return ret;
 106 }
 107
 108 static unsigned int
 109 v9fs_fd_poll(struct v9fs_transport *trans, struct poll_table_struct *pt)
 110 {
 111         int ret, n;
 112         struct v9fs_trans_fd *ts;
 113         mm_segment_t oldfs;
 114
 115         if (!trans || trans->status != Connected || !(ts = trans->priv))
 116                 return -EREMOTEIO;
 117
 118         if (!ts->rd->f_op || !ts->rd->f_op->poll)
 119                 return -EIO;
 120
 121         if (!ts->wr->f_op || !ts->wr->f_op->poll)
 122                 return -EIO;
 123
 124         oldfs = get_fs();
 125         set_fs(get_ds());
 126
 127         ret = ts->rd->f_op->poll(ts->rd, pt);
 128         if (ret < 0)
 129                 goto end;
 130
 131         if (ts->rd != ts->wr) {
 132                 n = ts->wr->f_op->poll(ts->wr, pt);
 133                 if (n < 0) {
 134                         ret = n;
 135                         goto end;
 136                 }
 137                 ret = (ret & ~POLLOUT) | (n & ~POLLIN);
 138         }
 139
 140       end:
 141         set_fs(oldfs);
 142         return ret;
 143 }
 144
 145 static int v9fs_fd_open(struct v9fs_session_info *v9ses, int rfd, int wfd)
 146 {
 147         struct v9fs_transport *trans = v9ses->transport;
 148         struct v9fs_trans_fd *ts = kmalloc(sizeof(struct v9fs_trans_fd),
 149                                            GFP_KERNEL);
 150         if (!ts)
 151                 return -ENOMEM;
 152
 153         ts->rd = fget(rfd);
 154         ts->wr = fget(wfd);
 155         if (!ts->rd || !ts->wr) {
 156                 if (ts->rd)
 157                         fput(ts->rd);
 158                 if (ts->wr)
 159                         fput(ts->wr);
 160                 kfree(ts);
 161                 return -EIO;
 162         }
 163
 164         trans->priv = ts;
 165         trans->status = Connected;
 166
 167         return 0;
 168 }
 169
 170 static int v9fs_fd_init(struct v9fs_session_info *v9ses, const char *addr,
 171                         char *data)
 172 {
 173         if (v9ses->rfdno == ~0 || v9ses->wfdno == ~0) {
 174                 printk(KERN_ERR "v9fs: Insufficient options for proto=fd\n");
 175                 return -ENOPROTOOPT;
 176         }
 177
 178         return v9fs_fd_open(v9ses, v9ses->rfdno, v9ses->wfdno);
 179 }
 180
 181 static int v9fs_socket_open(struct v9fs_session_info *v9ses,
 182                             struct socket *csocket)
 183 {
 184         int fd, ret;
 185
 186         csocket->sk->sk_allocation = GFP_NOIO;
 187         if ((fd = sock_map_fd(csocket)) < 0) {
 188                 eprintk(KERN_ERR, "v9fs_socket_open: failed to map fd\n");
 189                 ret = fd;
 190               release_csocket:
 191                 sock_release(csocket);
 192                 return ret;
 193         }
 194
 195         if ((ret = v9fs_fd_open(v9ses, fd, fd)) < 0) {
 196                 sockfd_put(csocket);
 197                 eprintk(KERN_ERR, "v9fs_socket_open: failed to open fd\n");
 198                 goto release_csocket;
 199         }
 200
 201         ((struct v9fs_trans_fd *)v9ses->transport->priv)->rd->f_flags |=
 202             O_NONBLOCK;
 203         return 0;
 204 }
 205
 206 static int v9fs_tcp_init(struct v9fs_session_info *v9ses, const char *addr,
 207                          char *data)
 208 {
 209         int ret;
 210         struct socket *csocket = NULL;
 211         struct sockaddr_in sin_server;
 212
 213         sin_server.sin_family = AF_INET;
 214         sin_server.sin_addr.s_addr = in_aton(addr);
 215         sin_server.sin_port = htons(v9ses->port);
 216         sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &csocket);
 217
 218         if (!csocket) {
 219                 eprintk(KERN_ERR, "v9fs_trans_tcp: problem creating socket\n");
 220                 return -1;
 221         }
 222
 223         ret = csocket->ops->connect(csocket,
 224                                     (struct sockaddr *)&sin_server,
 225                                     sizeof(struct sockaddr_in), 0);
 226         if (ret < 0) {
 227                 eprintk(KERN_ERR,
 228                         "v9fs_trans_tcp: problem connecting socket to %s\n",
 229                         addr);
 230                 return ret;
 231         }
 232
 233         return v9fs_socket_open(v9ses, csocket);
 234 }
 235
 236 static int
 237 v9fs_unix_init(struct v9fs_session_info *v9ses, const char *addr, char *data)
 238 {
 239         int ret;
 240         struct socket *csocket;
 241         struct sockaddr_un sun_server;
 242
 243         if (strlen(addr) > UNIX_PATH_MAX) {
 244                 eprintk(KERN_ERR, "v9fs_trans_unix: address too long: %s\n",
 245                         addr);
 246                 return -ENAMETOOLONG;
 247         }
 248
 249         sun_server.sun_family = PF_UNIX;
 250         strcpy(sun_server.sun_path, addr);
 251         sock_create_kern(PF_UNIX, SOCK_STREAM, 0, &csocket);
 252         ret = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server,
 253                         sizeof(struct sockaddr_un) - 1, 0);
 254         if (ret < 0) {
 255                 eprintk(KERN_ERR,
 256                         "v9fs_trans_unix: problem connecting socket: %s: %d\n",
 257                         addr, ret);
 258                 return ret;
 259         }
 260
 261         return v9fs_socket_open(v9ses, csocket);
 262 }
 263
 264 /**
 265  * v9fs_sock_close - shutdown socket
 266  * @trans: private socket structure
 267  *
 268  */
 269 static void v9fs_fd_close(struct v9fs_transport *trans)
 270 {
 271         struct v9fs_trans_fd *ts;
 272
 273         if (!trans)
 274                 return;
 275
 276         ts = xchg(&trans->priv, NULL);
 277
 278         if (!ts)
 279                 return;
 280
 281         trans->status = Disconnected;
 282         if (ts->rd)
 283                 fput(ts->rd);
 284         if (ts->wr)
 285                 fput(ts->wr);
 286         kfree(ts);
 287 }
 288
 289 struct v9fs_transport v9fs_trans_fd = {
 290         .init = v9fs_fd_init,
 291         .write = v9fs_fd_write,
 292         .read = v9fs_fd_read,
 293         .close = v9fs_fd_close,
 294         .poll = v9fs_fd_poll,
 295 };
 296
 297 struct v9fs_transport v9fs_trans_tcp = {
 298         .init = v9fs_tcp_init,
 299         .write = v9fs_fd_write,
 300         .read = v9fs_fd_read,
 301         .close = v9fs_fd_close,
 302         .poll = v9fs_fd_poll,
 303 };
 304
 305 struct v9fs_transport v9fs_trans_unix = {
 306         .init = v9fs_unix_init,
 307         .write = v9fs_fd_write,
 308         .read = v9fs_fd_read,
 309         .close = v9fs_fd_close,
 310         .poll = v9fs_fd_poll,
 311 };