trans_fd.c 6.9 KB

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