1 const char gateway_rcs[] = "$Id: gateway.c,v 1.44 2008/11/22 11:54:04 fabiankeil Exp $";
2 /*********************************************************************
4 * File : $Source: /cvsroot/ijbswa/current/gateway.c,v $
6 * Purpose : Contains functions to connect to a server, possibly
7 * using a "forwarder" (i.e. HTTP proxy and/or a SOCKS4
10 * Copyright : Written by and Copyright (C) 2001-2008 the SourceForge
11 * Privoxy team. http://www.privoxy.org/
13 * Based on the Internet Junkbuster originally written
14 * by and Copyright (C) 1997 Anonymous Coders and
15 * Junkbusters Corporation. http://www.junkbusters.com
17 * This program is free software; you can redistribute it
18 * and/or modify it under the terms of the GNU General
19 * Public License as published by the Free Software
20 * Foundation; either version 2 of the License, or (at
21 * your option) any later version.
23 * This program is distributed in the hope that it will
24 * be useful, but WITHOUT ANY WARRANTY; without even the
25 * implied warranty of MERCHANTABILITY or FITNESS FOR A
26 * PARTICULAR PURPOSE. See the GNU General Public
27 * License for more details.
29 * The GNU General Public License should be included with
30 * this file. If not, you can view it at
31 * http://www.gnu.org/copyleft/gpl.html
32 * or write to the Free Software Foundation, Inc., 59
33 * Temple Place - Suite 330, Boston, MA 02111-1307, USA.
37 * Revision 1.44 2008/11/22 11:54:04 fabiankeil
38 * Move log message around to include the socket number.
40 * Revision 1.43 2008/11/13 09:15:51 fabiankeil
41 * Make keep_alive_timeout static.
43 * Revision 1.42 2008/11/13 09:08:42 fabiankeil
44 * Add new config option: keep-alive-timeout.
46 * Revision 1.41 2008/11/08 15:29:58 fabiankeil
47 * Unify two debug messages.
49 * Revision 1.40 2008/11/08 15:14:05 fabiankeil
50 * Fix duplicated debugging check.
52 * Revision 1.39 2008/10/25 11:33:01 fabiankeil
53 * Remove already out-commented line left over from debugging.
55 * Revision 1.38 2008/10/24 17:33:00 fabiankeil
56 * - Tone the "keep-alive support is experimental" warning
57 * down a bit as hackish 0-chunk detection has been
58 * implemented recently.
59 * - Only show the "ndef HAVE_POLL" warning once on start-up.
61 * Revision 1.37 2008/10/23 17:40:53 fabiankeil
62 * Fix forget_connection() and mark_connection_unused(),
63 * which would both under certain circumstances access
64 * reusable_connection[MAX_REUSABLE_CONNECTIONS]. Oops.
66 * Revision 1.36 2008/10/18 19:49:15 fabiankeil
67 * - Factor close_unusable_connections() out of
68 * get_reusable_connection() to make sure we really check
69 * all the remembered connections, not just the ones before
70 * the next reusable one.
71 * - Plug two file descriptor leaks. Internally marking
72 * connections as closed doesn't cut it.
74 * Revision 1.35 2008/10/17 17:12:01 fabiankeil
75 * In socket_is_still_usable(), use select()
76 * and FD_ISSET() if poll() isn't available.
78 * Revision 1.34 2008/10/17 17:07:13 fabiankeil
79 * Add preliminary timeout support.
81 * Revision 1.33 2008/10/16 16:34:21 fabiankeil
82 * Fix two gcc44 warnings.
84 * Revision 1.32 2008/10/16 16:27:22 fabiankeil
85 * Fix compiler warning.
87 * Revision 1.31 2008/10/16 07:31:11 fabiankeil
88 * - Factor socket_is_still_usable() out of get_reusable_connection().
89 * - If poll() isn't available, show a warning and assume the socket
92 * Revision 1.30 2008/10/13 17:31:03 fabiankeil
93 * If a remembered connection is no longer usable and
94 * has been marked closed, don't bother checking if the
95 * destination matches.
97 * Revision 1.29 2008/10/11 16:59:41 fabiankeil
98 * Add missing dots for two log messages.
100 * Revision 1.28 2008/10/09 18:21:41 fabiankeil
101 * Flush work-in-progress changes to keep outgoing connections
102 * alive where possible. Incomplete and mostly #ifdef'd out.
104 * Revision 1.27 2008/09/27 15:05:51 fabiankeil
105 * Return only once in forwarded_connect().
107 * Revision 1.26 2008/08/18 17:42:06 fabiankeil
108 * Fix typo in macro name.
110 * Revision 1.25 2008/02/07 18:09:46 fabiankeil
112 * - make the buffers quite a bit smaller.
113 * - properly report "socks5 server unreachable" failures.
114 * - let strncpy() use the whole buffer. Using a length of 0xffu wasn't actually
115 * wrong, but requires too much thinking as it doesn't depend on the buffer size.
116 * - log a message if the socks5 server sends more data than expected.
117 * - add some assertions and comments.
119 * Revision 1.24 2008/02/04 14:56:29 fabiankeil
120 * - Fix a compiler warning.
121 * - Stop assuming that htonl(INADDR_NONE) equals INADDR_NONE.
123 * Revision 1.23 2008/02/04 13:11:35 fabiankeil
124 * Remember the cause of the SOCKS5 error for the CGI message.
126 * Revision 1.22 2008/02/03 13:46:15 fabiankeil
127 * Add SOCKS5 support. Patch #1862863 by Eric M. Hopper with minor changes.
129 * Revision 1.21 2007/07/28 12:30:03 fabiankeil
130 * Modified patch from Song Weijia (#1762559) to
131 * fix socks requests on big-endian platforms.
133 * Revision 1.20 2007/05/14 10:23:48 fabiankeil
134 * - Use strlcpy() instead of strcpy().
135 * - Use the same buffer for socks requests and socks responses.
136 * - Fix bogus warning about web_server_addr being used uninitialized.
138 * Revision 1.19 2007/01/25 14:09:45 fabiankeil
139 * - Save errors in socks4_connect() to csp->error_message.
140 * - Silence some gcc43 warnings, hopefully the right way.
142 * Revision 1.18 2006/07/18 14:48:46 david__schmidt
143 * Reorganizing the repository: swapping out what was HEAD (the old 3.1 branch)
144 * with what was really the latest development (the v_3_0_branch branch)
146 * Revision 1.16 2002/05/12 21:36:29 jongfoster
147 * Correcting function comments
149 * Revision 1.15 2002/03/26 22:29:54 swa
150 * we have a new homepage!
152 * Revision 1.14 2002/03/24 13:25:43 swa
153 * name change related issues
155 * Revision 1.13 2002/03/13 00:29:59 jongfoster
158 * Revision 1.12 2002/03/09 20:03:52 jongfoster
159 * - Making various functions return int rather than size_t.
160 * (Undoing a recent change). Since size_t is unsigned on
161 * Windows, functions like read_socket that return -1 on
162 * error cannot return a size_t.
164 * THIS WAS A MAJOR BUG - it caused frequent, unpredictable
165 * crashes, and also frequently caused JB to jump to 100%
166 * CPU and stay there. (Because it thought it had just
167 * read ((unsigned)-1) == 4Gb of data...)
169 * - The signature of write_socket has changed, it now simply
170 * returns success=0/failure=nonzero.
172 * - Trying to get rid of a few warnings --with-debug on
173 * Windows, I've introduced a new type "jb_socket". This is
174 * used for the socket file descriptors. On Windows, this
175 * is SOCKET (a typedef for unsigned). Everywhere else, it's
176 * an int. The error value can't be -1 any more, so it's
177 * now JB_INVALID_SOCKET (which is -1 on UNIX, and in
178 * Windows it maps to the #define INVALID_SOCKET.)
180 * - The signature of bind_port has changed.
182 * Revision 1.11 2002/03/08 17:46:04 jongfoster
183 * Fixing int/size_t warnings
185 * Revision 1.10 2002/03/07 03:50:19 oes
186 * - Improved handling of failed DNS lookups
187 * - Fixed compiler warnings
189 * Revision 1.9 2001/10/25 03:40:48 david__schmidt
190 * Change in porting tactics: OS/2's EMX porting layer doesn't allow multiple
191 * threads to call select() simultaneously. So, it's time to do a real, live,
192 * native OS/2 port. See defines for __EMX__ (the porting layer) vs. __OS2__
193 * (native). Both versions will work, but using __OS2__ offers multi-threading.
195 * Revision 1.8 2001/09/13 20:10:12 jongfoster
196 * Fixing missing #include under Windows
198 * Revision 1.7 2001/09/12 17:58:26 steudten
200 * add #include <string.h>
202 * Revision 1.6 2001/09/10 10:41:16 oes
203 * Added #include in.h
205 * Revision 1.5 2001/07/29 18:47:57 jongfoster
206 * Adding missing #include project.h
208 * Revision 1.4 2001/07/24 12:47:06 oes
209 * Applied BeOS support update by Eugenia
211 * Revision 1.3 2001/06/09 10:55:28 jongfoster
212 * Changing BUFSIZ ==> BUFFER_SIZE
214 * Revision 1.2 2001/06/07 23:11:38 jongfoster
215 * Removing gateways[] list - no longer used.
216 * Replacing function pointer in struct gateway with a directly
217 * called function forwarded_connect(), which can do the common
218 * task of deciding whether to connect to the web server or HTTP
220 * Replacing struct gateway with struct forward_spec
221 * Fixing bug with SOCKS4A and HTTP proxy server in combination.
222 * It was a bug which led to the connection being made to the web
223 * server rather than the HTTP proxy, and also a buffer overrun.
225 * Revision 1.1.1.1 2001/05/15 13:58:54 oes
226 * Initial import of version 2.9.3 source tree
229 *********************************************************************/
235 #include <sys/types.h>
238 #include <netinet/in.h>
246 #include <winsock2.h>
247 #endif /* def _WIN32 */
251 #endif /* def __BEOS__ */
255 #endif /* def __OS2__ */
260 #include "jbsockets.h"
262 #include "miscutil.h"
263 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
266 #include <sys/poll.h>
269 #endif /* def __GLIBC__ */
270 #endif /* HAVE_POLL */
271 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
273 const char gateway_h_rcs[] = GATEWAY_H_VERSION;
275 static jb_socket socks4_connect(const struct forward_spec * fwd,
276 const char * target_host,
278 struct client_state *csp);
280 static jb_socket socks5_connect(const struct forward_spec *fwd,
281 const char *target_host,
283 struct client_state *csp);
286 #define SOCKS_REQUEST_GRANTED 90
287 #define SOCKS_REQUEST_REJECT 91
288 #define SOCKS_REQUEST_IDENT_FAILED 92
289 #define SOCKS_REQUEST_IDENT_CONFLICT 93
291 #define SOCKS5_REQUEST_GRANTED 0
292 #define SOCKS5_REQUEST_FAILED 1
293 #define SOCKS5_REQUEST_DENIED 2
294 #define SOCKS5_REQUEST_NETWORK_UNREACHABLE 3
295 #define SOCKS5_REQUEST_HOST_UNREACHABLE 4
296 #define SOCKS5_REQUEST_CONNECTION_REFUSED 5
297 #define SOCKS5_REQUEST_TTL_EXPIRED 6
298 #define SOCKS5_REQUEST_PROTOCOL_ERROR 7
299 #define SOCKS5_REQUEST_BAD_ADDRESS_TYPE 8
301 /* structure of a socks client operation */
303 unsigned char vn; /* socks version number */
304 unsigned char cd; /* command code */
305 unsigned char dstport[2]; /* destination port */
306 unsigned char dstip[4]; /* destination address */
307 char userid; /* first byte of userid */
308 char padding[3]; /* make sure sizeof(struct socks_op) is endian-independent. */
309 /* more bytes of the userid follow, terminated by a NULL */
312 /* structure of a socks server reply */
314 unsigned char vn; /* socks version number */
315 unsigned char cd; /* command code */
316 unsigned char dstport[2]; /* destination port */
317 unsigned char dstip[4]; /* destination address */
320 static const char socks_userid[] = "anonymous";
322 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
324 #define MAX_REUSABLE_CONNECTIONS 100
325 static int keep_alive_timeout = DEFAULT_KEEP_ALIVE_TIMEOUT;
327 struct reusable_connection
342 static struct reusable_connection reusable_connection[MAX_REUSABLE_CONNECTIONS];
344 static int mark_connection_unused(jb_socket sfd);
345 static void mark_connection_closed(struct reusable_connection *closed_connection);
346 static int socket_is_still_usable(jb_socket sfd);
349 /*********************************************************************
351 * Function : initialize_reusable_connections
353 * Description : Initializes the reusable_connection structures.
354 * Must be called with connection_reuse_mutex locked.
360 *********************************************************************/
361 extern void initialize_reusable_connections(void)
363 unsigned int slot = 0;
365 log_error(LOG_LEVEL_INFO,
366 "Support for 'Connection: keep-alive' is experimental."
368 " Detecting already dead connections might not work"
369 " correctly on your platform."
370 #endif /* ndef HAVE_POLL */
373 for (slot = 0; slot < SZ(reusable_connection); slot++)
375 mark_connection_closed(&reusable_connection[slot]);
378 log_error(LOG_LEVEL_CONNECT, "Initialized %d socket slots.", slot);
382 /*********************************************************************
384 * Function : remember_connection
386 * Description : Remembers a connection for reuse later on.
389 * 1 : sfd = Open socket to remember.
390 * 2 : http = The destination for the connection.
391 * 3 : fwd = The forwarder settings used.
395 *********************************************************************/
396 void remember_connection(jb_socket sfd, const struct http_request *http,
397 const struct forward_spec *fwd)
399 unsigned int slot = 0;
400 int free_slot_found = FALSE;
402 assert(sfd != JB_INVALID_SOCKET);
404 if (mark_connection_unused(sfd))
409 privoxy_mutex_lock(&connection_reuse_mutex);
411 /* Find free socket slot. */
412 for (slot = 0; slot < SZ(reusable_connection); slot++)
414 if (reusable_connection[slot].sfd == JB_INVALID_SOCKET)
416 assert(reusable_connection[slot].in_use == 0);
417 log_error(LOG_LEVEL_CONNECT,
418 "Remembering socket %d for %s:%d in slot %d.",
419 sfd, http->host, http->port, slot);
420 free_slot_found = TRUE;
425 if (!free_slot_found)
427 log_error(LOG_LEVEL_CONNECT,
428 "No free slots found to remembering socket for %s:%d. Last slot %d.",
429 http->host, http->port, slot);
430 privoxy_mutex_unlock(&connection_reuse_mutex);
435 assert(NULL != http->host);
436 reusable_connection[slot].host = strdup(http->host);
437 if (NULL == reusable_connection[slot].host)
439 log_error(LOG_LEVEL_FATAL, "Out of memory saving socket.");
441 reusable_connection[slot].sfd = sfd;
442 reusable_connection[slot].port = http->port;
443 reusable_connection[slot].in_use = 0;
444 reusable_connection[slot].timestamp = time(NULL);
447 assert(reusable_connection[slot].gateway_host == NULL);
448 assert(reusable_connection[slot].gateway_port == 0);
449 assert(reusable_connection[slot].forwarder_type == SOCKS_NONE);
450 assert(reusable_connection[slot].forward_host == NULL);
451 assert(reusable_connection[slot].forward_port == 0);
453 reusable_connection[slot].forwarder_type = fwd->type;
454 if (NULL != fwd->gateway_host)
456 reusable_connection[slot].gateway_host = strdup(fwd->gateway_host);
457 if (NULL == reusable_connection[slot].gateway_host)
459 log_error(LOG_LEVEL_FATAL, "Out of memory saving gateway_host.");
464 reusable_connection[slot].gateway_host = NULL;
466 reusable_connection[slot].gateway_port = fwd->gateway_port;
468 if (NULL != fwd->forward_host)
470 reusable_connection[slot].forward_host = strdup(fwd->forward_host);
471 if (NULL == reusable_connection[slot].forward_host)
473 log_error(LOG_LEVEL_FATAL, "Out of memory saving forward_host.");
478 reusable_connection[slot].forward_host = NULL;
480 reusable_connection[slot].forward_port = fwd->forward_port;
482 privoxy_mutex_unlock(&connection_reuse_mutex);
486 /*********************************************************************
488 * Function : mark_connection_closed
490 * Description : Marks a reused connection closed.
491 * Must be called with connection_reuse_mutex locked.
494 * 1 : closed_connection = The connection to mark as closed.
498 *********************************************************************/
499 static void mark_connection_closed(struct reusable_connection *closed_connection)
501 closed_connection->in_use = FALSE;
502 closed_connection->sfd = JB_INVALID_SOCKET;
503 freez(closed_connection->host);
504 closed_connection->port = 0;
505 closed_connection->timestamp = 0;
506 closed_connection->forwarder_type = SOCKS_NONE;
507 freez(closed_connection->gateway_host);
508 closed_connection->gateway_port = 0;
509 freez(closed_connection->forward_host);
510 closed_connection->forward_port = 0;
514 /*********************************************************************
516 * Function : forget_connection
518 * Description : Removes a previously remembered connection from
519 * the list of reusable connections.
522 * 1 : sfd = The socket belonging to the connection in question.
526 *********************************************************************/
527 void forget_connection(jb_socket sfd)
529 unsigned int slot = 0;
531 assert(sfd != JB_INVALID_SOCKET);
533 privoxy_mutex_lock(&connection_reuse_mutex);
535 for (slot = 0; slot < SZ(reusable_connection); slot++)
537 if (reusable_connection[slot].sfd == sfd)
539 assert(reusable_connection[slot].in_use);
541 log_error(LOG_LEVEL_CONNECT,
542 "Forgetting socket %d for %s:%d in slot %d.",
543 sfd, reusable_connection[slot].host,
544 reusable_connection[slot].port, slot);
545 mark_connection_closed(&reusable_connection[slot]);
546 privoxy_mutex_unlock(&connection_reuse_mutex);
552 log_error(LOG_LEVEL_CONNECT,
553 "Socket %d already forgotten or never remembered.", sfd);
555 privoxy_mutex_unlock(&connection_reuse_mutex);
559 /*********************************************************************
561 * Function : connection_destination_matches
563 * Description : Determines whether a remembered connection can
564 * be reused. That is whether the destination and
565 * the forwarding settings match.
568 * 1 : connection = The connection to check.
569 * 2 : http = The destination for the connection.
570 * 3 : fwd = The forwarder settings.
572 * Returns : TRUE for yes, FALSE otherwise.
574 *********************************************************************/
575 static int connection_destination_matches(const struct reusable_connection *connection,
576 const struct http_request *http,
577 const struct forward_spec *fwd)
579 /* XXX: Start of duplicated checks for debugging purposes. */
580 if (strcmpic(connection->host, http->host))
585 if (connection->forwarder_type != fwd->type)
587 log_error(LOG_LEVEL_CONNECT, "Type mismatch: %d %d (%s)",
588 connection->forwarder_type, fwd->type, http->host);
591 if (connection->gateway_port != fwd->gateway_port)
593 log_error(LOG_LEVEL_CONNECT, "Gateway port mismatch: %d %d (%s)",
594 connection->gateway_port, fwd->gateway_port, http->host);
597 if (connection->forward_port != fwd->forward_port)
599 log_error(LOG_LEVEL_CONNECT, "Forward port mismatch: %d %d (%s)",
600 connection->forward_port, fwd->forward_port, http->host);
603 if (connection->port != http->port)
605 log_error(LOG_LEVEL_CONNECT, "Server port mismatch: %d %d (%s)",
606 connection->port, http->port, http->host);
610 /* XXX: End of duplicated checks for debugging purposes. */
612 if ((connection->forwarder_type != fwd->type)
613 || (connection->gateway_port != fwd->gateway_port)
614 || (connection->forward_port != fwd->forward_port)
615 || (connection->port != http->port))
620 if (( (NULL != connection->gateway_host)
621 && (NULL != fwd->gateway_host)
622 && strcmpic(connection->gateway_host, fwd->gateway_host))
623 && (connection->gateway_host != fwd->gateway_host))
625 log_error(LOG_LEVEL_CONNECT, "Gateway mismatch.");
629 if (( (NULL != connection->forward_host)
630 && (NULL != fwd->forward_host)
631 && strcmpic(connection->forward_host, fwd->forward_host))
632 && (connection->forward_host != fwd->forward_host))
634 log_error(LOG_LEVEL_CONNECT, "Forwarding proxy mismatch.");
638 return (!strcmpic(connection->host, http->host));
643 /*********************************************************************
645 * Function : close_unusable_connections
647 * Description : Closes remembered connections that have timed
648 * out or have been closed on the other side.
654 *********************************************************************/
655 static void close_unusable_connections(void)
657 unsigned int slot = 0;
659 for (slot = 0; slot < SZ(reusable_connection); slot++)
661 if (!reusable_connection[slot].in_use
662 && (JB_INVALID_SOCKET != reusable_connection[slot].sfd))
664 time_t time_open = time(NULL) - reusable_connection[slot].timestamp;
666 if (keep_alive_timeout < time_open)
668 log_error(LOG_LEVEL_CONNECT,
669 "The connection to %s:%d in slot %d timed out. "
670 "Closing socket %d. Timeout is: %d.",
671 reusable_connection[slot].host,
672 reusable_connection[slot].port, slot,
673 reusable_connection[slot].sfd, keep_alive_timeout);
674 close_socket(reusable_connection[slot].sfd);
675 mark_connection_closed(&reusable_connection[slot]);
679 if (!socket_is_still_usable(reusable_connection[slot].sfd))
681 log_error(LOG_LEVEL_CONNECT,
682 "The connection to %s:%d in slot %d is no longer usable. "
683 "Closing socket %d.", reusable_connection[slot].host,
684 reusable_connection[slot].port, slot,
685 reusable_connection[slot].sfd);
686 close_socket(reusable_connection[slot].sfd);
687 mark_connection_closed(&reusable_connection[slot]);
695 /*********************************************************************
697 * Function : socket_is_still_usable
699 * Description : Decides whether or not an open socket is still usable.
702 * 1 : sfd = The socket to check.
704 * Returns : TRUE for yes, otherwise FALSE.
706 *********************************************************************/
707 static int socket_is_still_usable(jb_socket sfd)
711 struct pollfd poll_fd[1];
713 memset(poll_fd, 0, sizeof(poll_fd));
715 poll_fd[0].events = POLLIN;
717 poll_result = poll(poll_fd, 1, 0);
719 if (-1 != poll_result)
721 return !(poll_fd[0].revents & POLLIN);
725 log_error(LOG_LEVEL_CONNECT, "Polling socket %d failed.", sfd);
730 struct timeval timeout;
732 int socket_is_alive = 0;
734 memset(&timeout, '\0', sizeof(timeout));
735 FD_ZERO(&readable_fds);
736 FD_SET(sfd, &readable_fds);
738 ret = select((int)sfd+1, &readable_fds, NULL, NULL, &timeout);
741 log_error(LOG_LEVEL_ERROR, "select() failed!: %E");
745 * XXX: I'm not sure why !FD_ISSET() works,
746 * but apparently it does.
748 socket_is_alive = !FD_ISSET(sfd, &readable_fds);
750 return socket_is_alive;
751 #endif /* def HAVE_POLL */
755 /*********************************************************************
757 * Function : get_reusable_connection
759 * Description : Returns an open socket to a previously remembered
760 * open connection (if there is one).
763 * 1 : http = The destination for the connection.
764 * 2 : fwd = The forwarder settings.
766 * Returns : JB_INVALID_SOCKET => No reusable connection found,
767 * otherwise a usable socket.
769 *********************************************************************/
770 static jb_socket get_reusable_connection(const struct http_request *http,
771 const struct forward_spec *fwd)
773 jb_socket sfd = JB_INVALID_SOCKET;
774 unsigned int slot = 0;
776 privoxy_mutex_lock(&connection_reuse_mutex);
778 close_unusable_connections();
780 for (slot = 0; slot < SZ(reusable_connection); slot++)
782 if (!reusable_connection[slot].in_use
783 && (JB_INVALID_SOCKET != reusable_connection[slot].sfd))
785 if (connection_destination_matches(&reusable_connection[slot], http, fwd))
787 reusable_connection[slot].in_use = TRUE;
788 sfd = reusable_connection[slot].sfd;
789 log_error(LOG_LEVEL_CONNECT,
790 "Found reusable socket %d for %s:%d in slot %d.",
791 sfd, reusable_connection[slot].host, reusable_connection[slot].port, slot);
797 privoxy_mutex_unlock(&connection_reuse_mutex);
804 /*********************************************************************
806 * Function : mark_connection_unused
808 * Description : Gives a remembered connection free for reuse.
811 * 1 : sfd = The socket belonging to the connection in question.
813 * Returns : TRUE => Socket found and marked as unused.
814 * FALSE => Socket not found.
816 *********************************************************************/
817 static int mark_connection_unused(jb_socket sfd)
819 unsigned int slot = 0;
820 int socket_found = FALSE;
822 assert(sfd != JB_INVALID_SOCKET);
824 privoxy_mutex_lock(&connection_reuse_mutex);
826 for (slot = 0; slot < SZ(reusable_connection); slot++)
828 if (reusable_connection[slot].sfd == sfd)
830 assert(reusable_connection[slot].in_use);
832 log_error(LOG_LEVEL_CONNECT,
833 "Marking open socket %d for %s:%d in slot %d as unused.",
834 sfd, reusable_connection[slot].host,
835 reusable_connection[slot].port, slot);
836 reusable_connection[slot].in_use = 0;
837 reusable_connection[slot].timestamp = time(NULL);
842 privoxy_mutex_unlock(&connection_reuse_mutex);
849 /*********************************************************************
851 * Function : set_keep_alive_timeout
853 * Description : Sets the timeout after which open
854 * connections will no longer be reused.
857 * 1 : timeout = The timeout in seconds.
861 *********************************************************************/
862 void set_keep_alive_timeout(int timeout)
864 keep_alive_timeout = timeout;
866 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
869 /*********************************************************************
871 * Function : forwarded_connect
873 * Description : Connect to a specified web server, possibly via
874 * a HTTP proxy and/or a SOCKS proxy.
877 * 1 : fwd = the proxies to use when connecting.
878 * 2 : http = the http request and apropos headers
879 * 3 : csp = Current client state (buffers, headers, etc...)
881 * Returns : JB_INVALID_SOCKET => failure, else it is the socket file descriptor.
883 *********************************************************************/
884 jb_socket forwarded_connect(const struct forward_spec * fwd,
885 struct http_request *http,
886 struct client_state *csp)
888 const char * dest_host;
890 jb_socket sfd = JB_INVALID_SOCKET;
892 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
893 sfd = get_reusable_connection(http, fwd);
894 if (JB_INVALID_SOCKET != sfd)
898 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
900 /* Figure out if we need to connect to the web server or a HTTP proxy. */
901 if (fwd->forward_host)
904 dest_host = fwd->forward_host;
905 dest_port = fwd->forward_port;
910 dest_host = http->host;
911 dest_port = http->port;
914 /* Connect, maybe using a SOCKS proxy */
918 sfd = connect_to(dest_host, dest_port, csp);
922 sfd = socks4_connect(fwd, dest_host, dest_port, csp);
925 sfd = socks5_connect(fwd, dest_host, dest_port, csp);
928 /* Should never get here */
929 log_error(LOG_LEVEL_FATAL,
930 "SOCKS4 impossible internal error - bad SOCKS type.");
933 if (JB_INVALID_SOCKET != sfd)
935 log_error(LOG_LEVEL_CONNECT,
936 "Created new connection to %s:%d on socket %d.",
937 http->host, http->port, sfd);
945 /*********************************************************************
947 * Function : socks4_connect
949 * Description : Connect to the SOCKS server, and connect through
950 * it to the specified server. This handles
951 * all the SOCKS negotiation, and returns a file
952 * descriptor for a socket which can be treated as a
953 * normal (non-SOCKS) socket.
955 * Logged error messages are saved to csp->error_message
956 * and later reused by error_response() for the CGI
957 * message. strdup allocation failures are handled there.
960 * 1 : fwd = Specifies the SOCKS proxy to use.
961 * 2 : target_host = The final server to connect to.
962 * 3 : target_port = The final port to connect to.
963 * 4 : csp = Current client state (buffers, headers, etc...)
965 * Returns : JB_INVALID_SOCKET => failure, else a socket file descriptor.
967 *********************************************************************/
968 static jb_socket socks4_connect(const struct forward_spec * fwd,
969 const char * target_host,
971 struct client_state *csp)
973 unsigned int web_server_addr;
974 char buf[BUFFER_SIZE];
975 struct socks_op *c = (struct socks_op *)buf;
976 struct socks_reply *s = (struct socks_reply *)buf;
983 if ((fwd->gateway_host == NULL) || (*fwd->gateway_host == '\0'))
985 /* XXX: Shouldn't the config file parser prevent this? */
986 errstr = "NULL gateway host specified.";
990 if (fwd->gateway_port <= 0)
992 errstr = "invalid gateway port specified.";
998 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
999 csp->error_message = strdup(errstr);
1001 return(JB_INVALID_SOCKET);
1004 /* build a socks request for connection to the web server */
1006 strlcpy(&(c->userid), socks_userid, sizeof(buf) - sizeof(struct socks_op));
1008 csiz = sizeof(*c) + sizeof(socks_userid) - sizeof(c->userid) - sizeof(c->padding);
1013 web_server_addr = resolve_hostname_to_ip(target_host);
1014 if (web_server_addr == INADDR_NONE)
1016 errstr = "could not resolve target host";
1017 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s %s", errstr, target_host);
1022 web_server_addr = htonl(web_server_addr);
1026 web_server_addr = 0x00000001;
1027 n = csiz + strlen(target_host) + 1;
1028 if (n > sizeof(buf))
1031 errstr = "buffer cbuf too small.";
1032 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
1037 strlcpy(buf + csiz, target_host, sizeof(buf) - sizeof(struct socks_op) - csiz);
1039 * What we forward to the socks4a server should have the
1040 * size of socks_op, plus the length of the userid plus
1041 * its \0 byte (which we don't have to add because the
1042 * first byte of the userid is counted twice as it's also
1043 * part of sock_op) minus the padding bytes (which are part
1044 * of the userid as well), plus the length of the target_host
1045 * (which is stored csiz bytes after the beginning of the buffer),
1046 * plus another \0 byte.
1048 assert(n == sizeof(struct socks_op) + strlen(&(c->userid)) - sizeof(c->padding) + strlen(buf + csiz) + 1);
1053 /* Should never get here */
1054 log_error(LOG_LEVEL_FATAL,
1055 "socks4_connect: SOCKS4 impossible internal error - bad SOCKS type.");
1057 return(JB_INVALID_SOCKET);
1062 csp->error_message = strdup(errstr);
1063 return(JB_INVALID_SOCKET);
1068 c->dstport[0] = (unsigned char)((target_port >> 8 ) & 0xff);
1069 c->dstport[1] = (unsigned char)((target_port ) & 0xff);
1070 c->dstip[0] = (unsigned char)((web_server_addr >> 24 ) & 0xff);
1071 c->dstip[1] = (unsigned char)((web_server_addr >> 16 ) & 0xff);
1072 c->dstip[2] = (unsigned char)((web_server_addr >> 8 ) & 0xff);
1073 c->dstip[3] = (unsigned char)((web_server_addr ) & 0xff);
1075 /* pass the request to the socks server */
1076 sfd = connect_to(fwd->gateway_host, fwd->gateway_port, csp);
1078 if (sfd == JB_INVALID_SOCKET)
1081 * XXX: connect_to should fill in the exact reason.
1082 * Most likely resolving the IP of the forwarder failed.
1084 errstr = "connect_to failed: see logfile for details";
1087 else if (write_socket(sfd, (char *)c, csiz))
1089 errstr = "SOCKS4 negotiation write failed.";
1090 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
1094 else if (read_socket(sfd, buf, sizeof(buf)) != sizeof(*s))
1096 errstr = "SOCKS4 negotiation read failed.";
1097 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
1104 csp->error_message = strdup(errstr);
1105 return(JB_INVALID_SOCKET);
1110 case SOCKS_REQUEST_GRANTED:
1112 case SOCKS_REQUEST_REJECT:
1113 errstr = "SOCKS request rejected or failed.";
1116 case SOCKS_REQUEST_IDENT_FAILED:
1117 errstr = "SOCKS request rejected because "
1118 "SOCKS server cannot connect to identd on the client.";
1121 case SOCKS_REQUEST_IDENT_CONFLICT:
1122 errstr = "SOCKS request rejected because "
1123 "the client program and identd report "
1124 "different user-ids.";
1129 snprintf(buf, sizeof(buf),
1130 "SOCKS request rejected for reason code %d.", s->cd);
1134 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
1135 csp->error_message = strdup(errstr);
1138 return(JB_INVALID_SOCKET);
1142 /*********************************************************************
1144 * Function : translate_socks5_error
1146 * Description : Translates a SOCKS errors to a string.
1149 * 1 : socks_error = The error code to translate.
1151 * Returns : The string translation.
1153 *********************************************************************/
1154 static const char *translate_socks5_error(int socks_error)
1156 switch (socks_error)
1158 /* XXX: these should be more descriptive */
1159 case SOCKS5_REQUEST_FAILED:
1160 return "SOCKS5 request failed";
1161 case SOCKS5_REQUEST_DENIED:
1162 return "SOCKS5 request denied";
1163 case SOCKS5_REQUEST_NETWORK_UNREACHABLE:
1164 return "SOCKS5 network unreachable";
1165 case SOCKS5_REQUEST_HOST_UNREACHABLE:
1166 return "SOCKS5 host unreachable";
1167 case SOCKS5_REQUEST_CONNECTION_REFUSED:
1168 return "SOCKS5 connection refused";
1169 case SOCKS5_REQUEST_TTL_EXPIRED:
1170 return "SOCKS5 TTL expired";
1171 case SOCKS5_REQUEST_PROTOCOL_ERROR:
1172 return "SOCKS5 client protocol error";
1173 case SOCKS5_REQUEST_BAD_ADDRESS_TYPE:
1174 return "SOCKS5 domain names unsupported";
1175 case SOCKS5_REQUEST_GRANTED:
1176 return "everything's peachy";
1178 return "SOCKS5 negotiation protocol error";
1182 /*********************************************************************
1184 * Function : socks5_connect
1186 * Description : Connect to the SOCKS server, and connect through
1187 * it to the specified server. This handles
1188 * all the SOCKS negotiation, and returns a file
1189 * descriptor for a socket which can be treated as a
1190 * normal (non-SOCKS) socket.
1193 * 1 : fwd = Specifies the SOCKS proxy to use.
1194 * 2 : target_host = The final server to connect to.
1195 * 3 : target_port = The final port to connect to.
1196 * 4 : csp = Current client state (buffers, headers, etc...)
1198 * Returns : JB_INVALID_SOCKET => failure, else a socket file descriptor.
1200 *********************************************************************/
1201 static jb_socket socks5_connect(const struct forward_spec *fwd,
1202 const char *target_host,
1204 struct client_state *csp)
1209 size_t client_pos = 0;
1210 int server_size = 0;
1213 const char *errstr = NULL;
1215 assert(fwd->gateway_host);
1216 if ((fwd->gateway_host == NULL) || (*fwd->gateway_host == '\0'))
1218 errstr = "NULL gateway host specified";
1222 if (fwd->gateway_port <= 0)
1225 * XXX: currently this can't happen because in
1226 * case of invalid gateway ports we use the defaults.
1227 * Of course we really shouldn't do that.
1229 errstr = "invalid gateway port specified";
1233 hostlen = strlen(target_host);
1234 if (hostlen > (size_t)255)
1236 errstr = "target host name is longer than 255 characters";
1240 if (fwd->type != SOCKS_5)
1242 /* Should never get here */
1243 log_error(LOG_LEVEL_FATAL,
1244 "SOCKS5 impossible internal error - bad SOCKS type");
1251 assert(errstr != NULL);
1252 log_error(LOG_LEVEL_CONNECT, "socks5_connect: %s", errstr);
1253 csp->error_message = strdup(errstr);
1254 return(JB_INVALID_SOCKET);
1257 /* pass the request to the socks server */
1258 sfd = connect_to(fwd->gateway_host, fwd->gateway_port, csp);
1260 if (sfd == JB_INVALID_SOCKET)
1262 errstr = "socks5 server unreachable";
1263 log_error(LOG_LEVEL_CONNECT, "socks5_connect: %s", errstr);
1264 csp->error_message = strdup(errstr);
1265 return(JB_INVALID_SOCKET);
1269 cbuf[client_pos++] = '\x05'; /* Version */
1270 cbuf[client_pos++] = '\x01'; /* One authentication method supported */
1271 cbuf[client_pos++] = '\x00'; /* The no authentication authentication method */
1273 if (write_socket(sfd, cbuf, client_pos))
1275 errstr = "SOCKS5 negotiation write failed";
1276 csp->error_message = strdup(errstr);
1277 log_error(LOG_LEVEL_CONNECT, "%s", errstr);
1279 return(JB_INVALID_SOCKET);
1282 if (read_socket(sfd, sbuf, sizeof(sbuf)) != 2)
1284 errstr = "SOCKS5 negotiation read failed";
1288 if (!err && (sbuf[0] != '\x05'))
1290 errstr = "SOCKS5 negotiation protocol version error";
1294 if (!err && (sbuf[1] == '\xff'))
1296 errstr = "SOCKS5 authentication required";
1300 if (!err && (sbuf[1] != '\x00'))
1302 errstr = "SOCKS5 negotiation protocol error";
1308 assert(errstr != NULL);
1309 log_error(LOG_LEVEL_CONNECT, "socks5_connect: %s", errstr);
1310 csp->error_message = strdup(errstr);
1313 return(JB_INVALID_SOCKET);
1317 cbuf[client_pos++] = '\x05'; /* Version */
1318 cbuf[client_pos++] = '\x01'; /* TCP connect */
1319 cbuf[client_pos++] = '\x00'; /* Reserved, must be 0x00 */
1320 cbuf[client_pos++] = '\x03'; /* Address is domain name */
1321 cbuf[client_pos++] = (char)(hostlen & 0xffu);
1322 assert(sizeof(cbuf) - client_pos > (size_t)255);
1323 /* Using strncpy because we really want the nul byte padding. */
1324 strncpy(cbuf + client_pos, target_host, sizeof(cbuf) - client_pos);
1325 client_pos += (hostlen & 0xffu);
1326 cbuf[client_pos++] = (char)((target_port >> 8) & 0xff);
1327 cbuf[client_pos++] = (char)((target_port ) & 0xff);
1329 if (write_socket(sfd, cbuf, client_pos))
1331 errstr = "SOCKS5 negotiation read failed";
1332 csp->error_message = strdup(errstr);
1333 log_error(LOG_LEVEL_CONNECT, "%s", errstr);
1336 return(JB_INVALID_SOCKET);
1339 server_size = read_socket(sfd, sbuf, sizeof(sbuf));
1340 if (server_size < 3)
1342 errstr = "SOCKS5 negotiation read failed";
1345 else if (server_size > 20)
1347 /* This is somewhat unexpected but doesn't realy matter. */
1348 log_error(LOG_LEVEL_CONNECT, "socks5_connect: read %d bytes "
1349 "from socks server. Would have accepted up to %d.",
1350 server_size, sizeof(sbuf));
1353 if (!err && (sbuf[0] != '\x05'))
1355 errstr = "SOCKS5 negotiation protocol version error";
1359 if (!err && (sbuf[2] != '\x00'))
1361 errstr = "SOCKS5 negotiation protocol error";
1367 if (sbuf[1] == SOCKS5_REQUEST_GRANTED)
1371 errstr = translate_socks5_error(sbuf[1]);
1375 assert(errstr != NULL);
1376 csp->error_message = strdup(errstr);
1377 log_error(LOG_LEVEL_CONNECT, "socks5_connect: %s", errstr);
1381 return(JB_INVALID_SOCKET);