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/config.h>
  29 #include <linux/in.h>
  30 #include <linux/module.h>
  31 #include <linux/net.h>
  32 #include <linux/ipv6.h>
  33 #include <linux/errno.h>
  34 #include <linux/kernel.h>
  35 #include <linux/un.h>
  36 #include <asm/uaccess.h>
  37 #include <linux/inet.h>
  38 #include <linux/idr.h>
  39 #include <linux/file.h>
  40
  41 #include "debug.h"
  42 #include "v9fs.h"
  43 #include "transport.h"
  44
  45 #define V9FS_PORT 564
  46
  47 struct v9fs_trans_fd {
  48         struct file *rd;
  49         struct file *wr;
  50 };
  51
  52 /**
  53  * v9fs_fd_read- read from a fd
  54  * @v9ses: session information
  55  * @v: buffer to receive data into
  56  * @len: size of receive buffer
  57  *
  58  */
  59 static int v9fs_fd_read(struct v9fs_transport *trans, void *v, int len)
  60 {
  61         int ret;
  62         struct v9fs_trans_fd *ts;
  63
  64         if (!trans || trans->status == Disconnected || !(ts = trans->priv))
  65                 return -EREMOTEIO;
  66
  67         if (!(ts->rd->f_flags & O_NONBLOCK))
  68                 dprintk(DEBUG_ERROR, "blocking read ...\n");
  69
  70         ret = kernel_read(ts->rd, ts->rd->f_pos, v, len);
  71         if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
  72                 trans->status = Disconnected;
  73         return ret;
  74 }
  75
  76 /**
  77  * v9fs_fd_write - write to a socket
  78  * @v9ses: session information
  79  * @v: buffer to send data from
  80  * @len: size of send buffer
  81  *
  82  */
  83 static int v9fs_fd_write(struct v9fs_transport *trans, void *v, int len)
  84 {
  85         int ret;
  86         mm_segment_t oldfs;
  87         struct v9fs_trans_fd *ts;
  88
  89         if (!trans || trans->status == Disconnected || !(ts = trans->priv))
  90                 return -EREMOTEIO;
  91
  92         if (!(ts->wr->f_flags & O_NONBLOCK))
  93                 dprintk(DEBUG_ERROR, "blocking write ...\n");
  94
  95         oldfs = get_fs();
  96         set_fs(get_ds());
  97         /* The cast to a user pointer is valid due to the set_fs() */
  98         ret = vfs_write(ts->wr, (void __user *)v, len, &ts->wr->f_pos);
  99         set_fs(oldfs);
 100
 101         if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
 102                 trans->status = Disconnected;
 103         return ret;
 104 }
 105
 106 static unsigned int
 107 v9fs_fd_poll(struct v9fs_transport *trans, struct poll_table_struct *pt)
 108 {
 109         int ret, n;
 110         struct v9fs_trans_fd *ts;
 111         mm_segment_t oldfs;
 112
 113         if (!trans || trans->status != Connected || !(ts = trans->priv))
 114                 return -EREMOTEIO;
 115
 116         if (!ts->rd->f_op || !ts->rd->f_op->poll)
 117                 return -EIO;
 118
 119         if (!ts->wr->f_op || !ts->wr->f_op->poll)
 120                 return -EIO;
 121
 122         oldfs = get_fs();
 123         set_fs(get_ds());
 124
 125         ret = ts->rd->f_op->poll(ts->rd, pt);
 126         if (ret < 0)
 127                 goto end;
 128
 129         if (ts->rd != ts->wr) {
 130                 n = ts->wr->f_op->poll(ts->wr, pt);
 131                 if (n < 0) {
 132                         ret = n;
 133                         goto end;
 134                 }
 135                 ret = (ret & ~POLLOUT) | (n & ~POLLIN);
 136         }
 137
 138       end:
 139         set_fs(oldfs);
 140         return ret;
 141 }
 142
 143 static int v9fs_fd_open(struct v9fs_session_info *v9ses, int rfd, int wfd)
 144 {
 145         struct v9fs_transport *trans = v9ses->transport;
 146         struct v9fs_trans_fd *ts = kmalloc(sizeof(struct v9fs_trans_fd),
 147                                            GFP_KERNEL);
 148         if (!ts)
 149                 return -ENOMEM;
 150
 151         ts->rd = fget(rfd);
 152         ts->wr = fget(wfd);
 153         if (!ts->rd || !ts->wr) {
 154                 if (ts->rd)
 155                         fput(ts->rd);
 156                 if (ts->wr)
 157                         fput(ts->wr);
 158                 kfree(ts);
 159                 return -EIO;
 160         }
 161
 162         trans->priv = ts;
 163         trans->status = Connected;
 164
 165         return 0;
 166 }
 167
 168 static int v9fs_fd_init(struct v9fs_session_info *v9ses, const char *addr,
 169                         char *data)
 170 {
 171         if (v9ses->rfdno == ~0 || v9ses->wfdno == ~0) {
 172                 printk(KERN_ERR "v9fs: Insufficient options for proto=fd\n");
 173                 return -ENOPROTOOPT;
 174         }
 175
 176         return v9fs_fd_open(v9ses, v9ses->rfdno, v9ses->wfdno);
 177 }
 178
 179 static int v9fs_socket_open(struct v9fs_session_info *v9ses,
 180                             struct socket *csocket)
 181 {
 182         int fd, ret;
 183
 184         csocket->sk->sk_allocation = GFP_NOIO;
 185         if ((fd = sock_map_fd(csocket)) < 0) {
 186                 eprintk(KERN_ERR, "v9fs_socket_open: failed to map fd\n");
 187                 ret = fd;
 188               release_csocket:
 189                 sock_release(csocket);
 190                 return ret;
 191         }
 192
 193         if ((ret = v9fs_fd_open(v9ses, fd, fd)) < 0) {
 194                 sockfd_put(csocket);
 195                 eprintk(KERN_ERR, "v9fs_socket_open: failed to open fd\n");
 196                 goto release_csocket;
 197         }
 198
 199         ((struct v9fs_trans_fd *)v9ses->transport->priv)->rd->f_flags |=
 200             O_NONBLOCK;
 201         return 0;
 202 }
 203
 204 static int v9fs_tcp_init(struct v9fs_session_info *v9ses, const char *addr,
 205                          char *data)
 206 {
 207         int ret;
 208         struct socket *csocket = NULL;
 209         struct sockaddr_in sin_server;
 210
 211         sin_server.sin_family = AF_INET;
 212         sin_server.sin_addr.s_addr = in_aton(addr);
 213         sin_server.sin_port = htons(v9ses->port);
 214         sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &csocket);
 215
 216         if (!csocket) {
 217                 eprintk(KERN_ERR, "v9fs_trans_tcp: problem creating socket\n");
 218                 return -1;
 219         }
 220
 221         ret = csocket->ops->connect(csocket,
 222                                     (struct sockaddr *)&sin_server,
 223                                     sizeof(struct sockaddr_in), 0);
 224         if (ret < 0) {
 225                 eprintk(KERN_ERR,
 226                         "v9fs_trans_tcp: problem connecting socket to %s\n",
 227                         addr);
 228                 return ret;
 229         }
 230
 231         return v9fs_socket_open(v9ses, csocket);
 232 }
 233
 234 static int
 235 v9fs_unix_init(struct v9fs_session_info *v9ses, const char *addr, char *data)
 236 {
 237         int ret;
 238         struct socket *csocket;
 239         struct sockaddr_un sun_server;
 240
 241         if (strlen(addr) > UNIX_PATH_MAX) {
 242                 eprintk(KERN_ERR, "v9fs_trans_unix: address too long: %s\n",
 243                         addr);
 244                 return -ENAMETOOLONG;
 245         }
 246
 247         sun_server.sun_family = PF_UNIX;
 248         strcpy(sun_server.sun_path, addr);
 249         sock_create_kern(PF_UNIX, SOCK_STREAM, 0, &csocket);
 250         ret = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server,
 251                         sizeof(struct sockaddr_un) - 1, 0);
 252         if (ret < 0) {
 253                 eprintk(KERN_ERR,
 254                         "v9fs_trans_unix: problem connecting socket: %s: %d\n",
 255                         addr, ret);
 256                 return ret;
 257         }
 258
 259         return v9fs_socket_open(v9ses, csocket);
 260 }
 261
 262 /**
 263  * v9fs_sock_close - shutdown socket
 264  * @trans: private socket structure
 265  *
 266  */
 267 static void v9fs_fd_close(struct v9fs_transport *trans)
 268 {
 269         struct v9fs_trans_fd *ts;
 270
 271         if (!trans)
 272                 return;
 273
 274         ts = xchg(&trans->priv, NULL);
 275
 276         if (!ts)
 277                 return;
 278
 279         trans->status = Disconnected;
 280         if (ts->rd)
 281                 fput(ts->rd);
 282         if (ts->wr)
 283                 fput(ts->wr);
 284         kfree(ts);
 285 }
 286
 287 struct v9fs_transport v9fs_trans_fd = {
 288         .init = v9fs_fd_init,
 289         .write = v9fs_fd_write,
 290         .read = v9fs_fd_read,
 291         .close = v9fs_fd_close,
 292         .poll = v9fs_fd_poll,
 293 };
 294
 295 struct v9fs_transport v9fs_trans_tcp = {
 296         .init = v9fs_tcp_init,
 297         .write = v9fs_fd_write,
 298         .read = v9fs_fd_read,
 299         .close = v9fs_fd_close,
 300         .poll = v9fs_fd_poll,
 301 };
 302
 303 struct v9fs_transport v9fs_trans_unix = {
 304         .init = v9fs_unix_init,
 305         .write = v9fs_fd_write,
 306         .read = v9fs_fd_read,
 307         .close = v9fs_fd_close,
 308         .poll = v9fs_fd_poll,
 309 };