net/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 <linux/uaccess.h>
  36 #include <linux/inet.h>
  37 #include <linux/idr.h>
  38 #include <linux/file.h>
  39 #include <net/9p/9p.h>
  40 #include <net/9p/transport.h>
  41
  42 #define P9_PORT 564
  43
  44 struct p9_trans_fd {
  45         struct file *rd;
  46         struct file *wr;
  47 };
  48
  49 static int p9_socket_open(struct p9_transport *trans, struct socket *csocket);
  50 static int p9_fd_open(struct p9_transport *trans, int rfd, int wfd);
  51 static int p9_fd_read(struct p9_transport *trans, void *v, int len);
  52 static int p9_fd_write(struct p9_transport *trans, void *v, int len);
  53 static unsigned int p9_fd_poll(struct p9_transport *trans,
  54                                                 struct poll_table_struct *pt);
  55 static void p9_fd_close(struct p9_transport *trans);
  56
  57 struct p9_transport *p9_trans_create_tcp(const char *addr, int port)
  58 {
  59         int err;
  60         struct p9_transport *trans;
  61         struct socket *csocket;
  62         struct sockaddr_in sin_server;
  63
  64         csocket = NULL;
  65         trans = kmalloc(sizeof(struct p9_transport), GFP_KERNEL);
  66         if (!trans)
  67                 return ERR_PTR(-ENOMEM);
  68
  69         trans->write = p9_fd_write;
  70         trans->read = p9_fd_read;
  71         trans->close = p9_fd_close;
  72         trans->poll = p9_fd_poll;
  73
  74         sin_server.sin_family = AF_INET;
  75         sin_server.sin_addr.s_addr = in_aton(addr);
  76         sin_server.sin_port = htons(port);
  77         sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &csocket);
  78
  79         if (!csocket) {
  80                 P9_EPRINTK(KERN_ERR, "p9_trans_tcp: problem creating socket\n");
  81                 err = -EIO;
  82                 goto error;
  83         }
  84
  85         err = csocket->ops->connect(csocket,
  86                                     (struct sockaddr *)&sin_server,
  87                                     sizeof(struct sockaddr_in), 0);
  88         if (err < 0) {
  89                 P9_EPRINTK(KERN_ERR,
  90                         "p9_trans_tcp: problem connecting socket to %s\n",
  91                         addr);
  92                 goto error;
  93         }
  94
  95         err = p9_socket_open(trans, csocket);
  96         if (err < 0)
  97                 goto error;
  98
  99         return trans;
 100
 101 error:
 102         if (csocket)
 103                 sock_release(csocket);
 104
 105         kfree(trans);
 106         return ERR_PTR(err);
 107 }
 108 EXPORT_SYMBOL(p9_trans_create_tcp);
 109
 110 struct p9_transport *p9_trans_create_unix(const char *addr)
 111 {
 112         int err;
 113         struct socket *csocket;
 114         struct sockaddr_un sun_server;
 115         struct p9_transport *trans;
 116
 117         csocket = NULL;
 118         trans = kmalloc(sizeof(struct p9_transport), GFP_KERNEL);
 119         if (!trans)
 120                 return ERR_PTR(-ENOMEM);
 121
 122         trans->write = p9_fd_write;
 123         trans->read = p9_fd_read;
 124         trans->close = p9_fd_close;
 125         trans->poll = p9_fd_poll;
 126
 127         if (strlen(addr) > UNIX_PATH_MAX) {
 128                 P9_EPRINTK(KERN_ERR, "p9_trans_unix: address too long: %s\n",
 129                         addr);
 130                 err = -ENAMETOOLONG;
 131                 goto error;
 132         }
 133
 134         sun_server.sun_family = PF_UNIX;
 135         strcpy(sun_server.sun_path, addr);
 136         sock_create_kern(PF_UNIX, SOCK_STREAM, 0, &csocket);
 137         err = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server,
 138                         sizeof(struct sockaddr_un) - 1, 0);
 139         if (err < 0) {
 140                 P9_EPRINTK(KERN_ERR,
 141                         "p9_trans_unix: problem connecting socket: %s: %d\n",
 142                         addr, err);
 143                 goto error;
 144         }
 145
 146         err = p9_socket_open(trans, csocket);
 147         if (err < 0)
 148                 goto error;
 149
 150         return trans;
 151
 152 error:
 153         if (csocket)
 154                 sock_release(csocket);
 155
 156         kfree(trans);
 157         return ERR_PTR(err);
 158 }
 159 EXPORT_SYMBOL(p9_trans_create_unix);
 160
 161 struct p9_transport *p9_trans_create_fd(int rfd, int wfd)
 162 {
 163         int err;
 164         struct p9_transport *trans;
 165
 166         if (rfd == ~0 || wfd == ~0) {
 167                 printk(KERN_ERR "v9fs: Insufficient options for proto=fd\n");
 168                 return ERR_PTR(-ENOPROTOOPT);
 169         }
 170
 171         trans = kmalloc(sizeof(struct p9_transport), GFP_KERNEL);
 172         if (!trans)
 173                 return ERR_PTR(-ENOMEM);
 174
 175         trans->write = p9_fd_write;
 176         trans->read = p9_fd_read;
 177         trans->close = p9_fd_close;
 178         trans->poll = p9_fd_poll;
 179
 180         err = p9_fd_open(trans, rfd, wfd);
 181         if (err < 0)
 182                 goto error;
 183
 184         return trans;
 185
 186 error:
 187         kfree(trans);
 188         return ERR_PTR(err);
 189 }
 190 EXPORT_SYMBOL(p9_trans_create_fd);
 191
 192 static int p9_socket_open(struct p9_transport *trans, struct socket *csocket)
 193 {
 194         int fd, ret;
 195
 196         csocket->sk->sk_allocation = GFP_NOIO;
 197         fd = sock_map_fd(csocket);
 198         if (fd < 0) {
 199                 P9_EPRINTK(KERN_ERR, "p9_socket_open: failed to map fd\n");
 200                 return fd;
 201         }
 202
 203         ret = p9_fd_open(trans, fd, fd);
 204         if (ret < 0) {
 205                 P9_EPRINTK(KERN_ERR, "p9_socket_open: failed to open fd\n");
 206                 sockfd_put(csocket);
 207                 return ret;
 208         }
 209
 210         ((struct p9_trans_fd *)trans->priv)->rd->f_flags |= O_NONBLOCK;
 211
 212         return 0;
 213 }
 214
 215 static int p9_fd_open(struct p9_transport *trans, int rfd, int wfd)
 216 {
 217         struct p9_trans_fd *ts = kmalloc(sizeof(struct p9_trans_fd),
 218                                            GFP_KERNEL);
 219         if (!ts)
 220                 return -ENOMEM;
 221
 222         ts->rd = fget(rfd);
 223         ts->wr = fget(wfd);
 224         if (!ts->rd || !ts->wr) {
 225                 if (ts->rd)
 226                         fput(ts->rd);
 227                 if (ts->wr)
 228                         fput(ts->wr);
 229                 kfree(ts);
 230                 return -EIO;
 231         }
 232
 233         trans->priv = ts;
 234         trans->status = Connected;
 235
 236         return 0;
 237 }
 238
 239 /**
 240  * p9_fd_read- read from a fd
 241  * @v9ses: session information
 242  * @v: buffer to receive data into
 243  * @len: size of receive buffer
 244  *
 245  */
 246 static int p9_fd_read(struct p9_transport *trans, void *v, int len)
 247 {
 248         int ret;
 249         struct p9_trans_fd *ts = NULL;
 250
 251         if (trans && trans->status != Disconnected)
 252                 ts = trans->priv;
 253
 254         if (!ts)
 255                 return -EREMOTEIO;
 256
 257         if (!(ts->rd->f_flags & O_NONBLOCK))
 258                 P9_DPRINTK(P9_DEBUG_ERROR, "blocking read ...\n");
 259
 260         ret = kernel_read(ts->rd, ts->rd->f_pos, v, len);
 261         if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
 262                 trans->status = Disconnected;
 263         return ret;
 264 }
 265
 266 /**
 267  * p9_fd_write - write to a socket
 268  * @v9ses: session information
 269  * @v: buffer to send data from
 270  * @len: size of send buffer
 271  *
 272  */
 273 static int p9_fd_write(struct p9_transport *trans, void *v, int len)
 274 {
 275         int ret;
 276         mm_segment_t oldfs;
 277         struct p9_trans_fd *ts = NULL;
 278
 279         if (trans && trans->status != Disconnected)
 280                 ts = trans->priv;
 281
 282         if (!ts)
 283                 return -EREMOTEIO;
 284
 285         if (!(ts->wr->f_flags & O_NONBLOCK))
 286                 P9_DPRINTK(P9_DEBUG_ERROR, "blocking write ...\n");
 287
 288         oldfs = get_fs();
 289         set_fs(get_ds());
 290         /* The cast to a user pointer is valid due to the set_fs() */
 291         ret = vfs_write(ts->wr, (void __user *)v, len, &ts->wr->f_pos);
 292         set_fs(oldfs);
 293
 294         if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
 295                 trans->status = Disconnected;
 296         return ret;
 297 }
 298
 299 static unsigned int
 300 p9_fd_poll(struct p9_transport *trans, struct poll_table_struct *pt)
 301 {
 302         int ret, n;
 303         struct p9_trans_fd *ts = NULL;
 304         mm_segment_t oldfs;
 305
 306         if (trans && trans->status == Connected)
 307                 ts = trans->priv;
 308
 309         if (!ts)
 310                 return -EREMOTEIO;
 311
 312         if (!ts->rd->f_op || !ts->rd->f_op->poll)
 313                 return -EIO;
 314
 315         if (!ts->wr->f_op || !ts->wr->f_op->poll)
 316                 return -EIO;
 317
 318         oldfs = get_fs();
 319         set_fs(get_ds());
 320
 321         ret = ts->rd->f_op->poll(ts->rd, pt);
 322         if (ret < 0)
 323                 goto end;
 324
 325         if (ts->rd != ts->wr) {
 326                 n = ts->wr->f_op->poll(ts->wr, pt);
 327                 if (n < 0) {
 328                         ret = n;
 329                         goto end;
 330                 }
 331                 ret = (ret & ~POLLOUT) | (n & ~POLLIN);
 332         }
 333
 334 end:
 335         set_fs(oldfs);
 336         return ret;
 337 }
 338
 339 /**
 340  * p9_sock_close - shutdown socket
 341  * @trans: private socket structure
 342  *
 343  */
 344 static void p9_fd_close(struct p9_transport *trans)
 345 {
 346         struct p9_trans_fd *ts;
 347
 348         if (!trans)
 349                 return;
 350
 351         ts = xchg(&trans->priv, NULL);
 352
 353         if (!ts)
 354                 return;
 355
 356         trans->status = Disconnected;
 357         if (ts->rd)
 358                 fput(ts->rd);
 359         if (ts->wr)
 360                 fput(ts->wr);
 361         kfree(ts);
 362 }
 363