1 const char gateway_rcs[] = "$Id: gateway.c,v 1.42 2008/11/13 09:08:42 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 1.42 2008/11/13 09:08:42 fabiankeil
38 * Add new config option: keep-alive-timeout.
40 * Revision 1.41 2008/11/08 15:29:58 fabiankeil
41 * Unify two debug messages.
43 * Revision 1.40 2008/11/08 15:14:05 fabiankeil
44 * Fix duplicated debugging check.
46 * Revision 1.39 2008/10/25 11:33:01 fabiankeil
47 * Remove already out-commented line left over from debugging.
49 * Revision 1.38 2008/10/24 17:33:00 fabiankeil
50 * - Tone the "keep-alive support is experimental" warning
51 * down a bit as hackish 0-chunk detection has been
52 * implemented recently.
53 * - Only show the "ndef HAVE_POLL" warning once on start-up.
55 * Revision 1.37 2008/10/23 17:40:53 fabiankeil
56 * Fix forget_connection() and mark_connection_unused(),
57 * which would both under certain circumstances access
58 * reusable_connection[MAX_REUSABLE_CONNECTIONS]. Oops.
60 * Revision 1.36 2008/10/18 19:49:15 fabiankeil
61 * - Factor close_unusable_connections() out of
62 * get_reusable_connection() to make sure we really check
63 * all the remembered connections, not just the ones before
64 * the next reusable one.
65 * - Plug two file descriptor leaks. Internally marking
66 * connections as closed doesn't cut it.
68 * Revision 1.35 2008/10/17 17:12:01 fabiankeil
69 * In socket_is_still_usable(), use select()
70 * and FD_ISSET() if poll() isn't available.
72 * Revision 1.34 2008/10/17 17:07:13 fabiankeil
73 * Add preliminary timeout support.
75 * Revision 1.33 2008/10/16 16:34:21 fabiankeil
76 * Fix two gcc44 warnings.
78 * Revision 1.32 2008/10/16 16:27:22 fabiankeil
79 * Fix compiler warning.
81 * Revision 1.31 2008/10/16 07:31:11 fabiankeil
82 * - Factor socket_is_still_usable() out of get_reusable_connection().
83 * - If poll() isn't available, show a warning and assume the socket
86 * Revision 1.30 2008/10/13 17:31:03 fabiankeil
87 * If a remembered connection is no longer usable and
88 * has been marked closed, don't bother checking if the
89 * destination matches.
91 * Revision 1.29 2008/10/11 16:59:41 fabiankeil
92 * Add missing dots for two log messages.
94 * Revision 1.28 2008/10/09 18:21:41 fabiankeil
95 * Flush work-in-progress changes to keep outgoing connections
96 * alive where possible. Incomplete and mostly #ifdef'd out.
98 * Revision 1.27 2008/09/27 15:05:51 fabiankeil
99 * Return only once in forwarded_connect().
101 * Revision 1.26 2008/08/18 17:42:06 fabiankeil
102 * Fix typo in macro name.
104 * Revision 1.25 2008/02/07 18:09:46 fabiankeil
106 * - make the buffers quite a bit smaller.
107 * - properly report "socks5 server unreachable" failures.
108 * - let strncpy() use the whole buffer. Using a length of 0xffu wasn't actually
109 * wrong, but requires too much thinking as it doesn't depend on the buffer size.
110 * - log a message if the socks5 server sends more data than expected.
111 * - add some assertions and comments.
113 * Revision 1.24 2008/02/04 14:56:29 fabiankeil
114 * - Fix a compiler warning.
115 * - Stop assuming that htonl(INADDR_NONE) equals INADDR_NONE.
117 * Revision 1.23 2008/02/04 13:11:35 fabiankeil
118 * Remember the cause of the SOCKS5 error for the CGI message.
120 * Revision 1.22 2008/02/03 13:46:15 fabiankeil
121 * Add SOCKS5 support. Patch #1862863 by Eric M. Hopper with minor changes.
123 * Revision 1.21 2007/07/28 12:30:03 fabiankeil
124 * Modified patch from Song Weijia (#1762559) to
125 * fix socks requests on big-endian platforms.
127 * Revision 1.20 2007/05/14 10:23:48 fabiankeil
128 * - Use strlcpy() instead of strcpy().
129 * - Use the same buffer for socks requests and socks responses.
130 * - Fix bogus warning about web_server_addr being used uninitialized.
132 * Revision 1.19 2007/01/25 14:09:45 fabiankeil
133 * - Save errors in socks4_connect() to csp->error_message.
134 * - Silence some gcc43 warnings, hopefully the right way.
136 * Revision 1.18 2006/07/18 14:48:46 david__schmidt
137 * Reorganizing the repository: swapping out what was HEAD (the old 3.1 branch)
138 * with what was really the latest development (the v_3_0_branch branch)
140 * Revision 1.16 2002/05/12 21:36:29 jongfoster
141 * Correcting function comments
143 * Revision 1.15 2002/03/26 22:29:54 swa
144 * we have a new homepage!
146 * Revision 1.14 2002/03/24 13:25:43 swa
147 * name change related issues
149 * Revision 1.13 2002/03/13 00:29:59 jongfoster
152 * Revision 1.12 2002/03/09 20:03:52 jongfoster
153 * - Making various functions return int rather than size_t.
154 * (Undoing a recent change). Since size_t is unsigned on
155 * Windows, functions like read_socket that return -1 on
156 * error cannot return a size_t.
158 * THIS WAS A MAJOR BUG - it caused frequent, unpredictable
159 * crashes, and also frequently caused JB to jump to 100%
160 * CPU and stay there. (Because it thought it had just
161 * read ((unsigned)-1) == 4Gb of data...)
163 * - The signature of write_socket has changed, it now simply
164 * returns success=0/failure=nonzero.
166 * - Trying to get rid of a few warnings --with-debug on
167 * Windows, I've introduced a new type "jb_socket". This is
168 * used for the socket file descriptors. On Windows, this
169 * is SOCKET (a typedef for unsigned). Everywhere else, it's
170 * an int. The error value can't be -1 any more, so it's
171 * now JB_INVALID_SOCKET (which is -1 on UNIX, and in
172 * Windows it maps to the #define INVALID_SOCKET.)
174 * - The signature of bind_port has changed.
176 * Revision 1.11 2002/03/08 17:46:04 jongfoster
177 * Fixing int/size_t warnings
179 * Revision 1.10 2002/03/07 03:50:19 oes
180 * - Improved handling of failed DNS lookups
181 * - Fixed compiler warnings
183 * Revision 1.9 2001/10/25 03:40:48 david__schmidt
184 * Change in porting tactics: OS/2's EMX porting layer doesn't allow multiple
185 * threads to call select() simultaneously. So, it's time to do a real, live,
186 * native OS/2 port. See defines for __EMX__ (the porting layer) vs. __OS2__
187 * (native). Both versions will work, but using __OS2__ offers multi-threading.
189 * Revision 1.8 2001/09/13 20:10:12 jongfoster
190 * Fixing missing #include under Windows
192 * Revision 1.7 2001/09/12 17:58:26 steudten
194 * add #include <string.h>
196 * Revision 1.6 2001/09/10 10:41:16 oes
197 * Added #include in.h
199 * Revision 1.5 2001/07/29 18:47:57 jongfoster
200 * Adding missing #include project.h
202 * Revision 1.4 2001/07/24 12:47:06 oes
203 * Applied BeOS support update by Eugenia
205 * Revision 1.3 2001/06/09 10:55:28 jongfoster
206 * Changing BUFSIZ ==> BUFFER_SIZE
208 * Revision 1.2 2001/06/07 23:11:38 jongfoster
209 * Removing gateways[] list - no longer used.
210 * Replacing function pointer in struct gateway with a directly
211 * called function forwarded_connect(), which can do the common
212 * task of deciding whether to connect to the web server or HTTP
214 * Replacing struct gateway with struct forward_spec
215 * Fixing bug with SOCKS4A and HTTP proxy server in combination.
216 * It was a bug which led to the connection being made to the web
217 * server rather than the HTTP proxy, and also a buffer overrun.
219 * Revision 1.1.1.1 2001/05/15 13:58:54 oes
220 * Initial import of version 2.9.3 source tree
223 *********************************************************************/
229 #include <sys/types.h>
232 #include <netinet/in.h>
240 #include <winsock2.h>
241 #endif /* def _WIN32 */
245 #endif /* def __BEOS__ */
249 #endif /* def __OS2__ */
254 #include "jbsockets.h"
256 #include "miscutil.h"
257 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
260 #include <sys/poll.h>
263 #endif /* def __GLIBC__ */
264 #endif /* HAVE_POLL */
265 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
267 const char gateway_h_rcs[] = GATEWAY_H_VERSION;
269 static jb_socket socks4_connect(const struct forward_spec * fwd,
270 const char * target_host,
272 struct client_state *csp);
274 static jb_socket socks5_connect(const struct forward_spec *fwd,
275 const char *target_host,
277 struct client_state *csp);
280 #define SOCKS_REQUEST_GRANTED 90
281 #define SOCKS_REQUEST_REJECT 91
282 #define SOCKS_REQUEST_IDENT_FAILED 92
283 #define SOCKS_REQUEST_IDENT_CONFLICT 93
285 #define SOCKS5_REQUEST_GRANTED 0
286 #define SOCKS5_REQUEST_FAILED 1
287 #define SOCKS5_REQUEST_DENIED 2
288 #define SOCKS5_REQUEST_NETWORK_UNREACHABLE 3
289 #define SOCKS5_REQUEST_HOST_UNREACHABLE 4
290 #define SOCKS5_REQUEST_CONNECTION_REFUSED 5
291 #define SOCKS5_REQUEST_TTL_EXPIRED 6
292 #define SOCKS5_REQUEST_PROTOCOL_ERROR 7
293 #define SOCKS5_REQUEST_BAD_ADDRESS_TYPE 8
295 /* structure of a socks client operation */
297 unsigned char vn; /* socks version number */
298 unsigned char cd; /* command code */
299 unsigned char dstport[2]; /* destination port */
300 unsigned char dstip[4]; /* destination address */
301 char userid; /* first byte of userid */
302 char padding[3]; /* make sure sizeof(struct socks_op) is endian-independent. */
303 /* more bytes of the userid follow, terminated by a NULL */
306 /* structure of a socks server reply */
308 unsigned char vn; /* socks version number */
309 unsigned char cd; /* command code */
310 unsigned char dstport[2]; /* destination port */
311 unsigned char dstip[4]; /* destination address */
314 static const char socks_userid[] = "anonymous";
316 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
318 #define MAX_REUSABLE_CONNECTIONS 100
319 static int keep_alive_timeout = DEFAULT_KEEP_ALIVE_TIMEOUT;
321 struct reusable_connection
336 static struct reusable_connection reusable_connection[MAX_REUSABLE_CONNECTIONS];
338 static int mark_connection_unused(jb_socket sfd);
339 static void mark_connection_closed(struct reusable_connection *closed_connection);
340 static int socket_is_still_usable(jb_socket sfd);
343 /*********************************************************************
345 * Function : initialize_reusable_connections
347 * Description : Initializes the reusable_connection structures.
348 * Must be called with connection_reuse_mutex locked.
354 *********************************************************************/
355 extern void initialize_reusable_connections(void)
357 unsigned int slot = 0;
359 log_error(LOG_LEVEL_INFO,
360 "Support for 'Connection: keep-alive' is experimental."
362 " Detecting already dead connections might not work"
363 " correctly on your platform."
364 #endif /* ndef HAVE_POLL */
367 for (slot = 0; slot < SZ(reusable_connection); slot++)
369 mark_connection_closed(&reusable_connection[slot]);
372 log_error(LOG_LEVEL_CONNECT, "Initialized %d socket slots.", slot);
376 /*********************************************************************
378 * Function : remember_connection
380 * Description : Remembers a connection for reuse later on.
383 * 1 : sfd = Open socket to remember.
384 * 2 : http = The destination for the connection.
385 * 3 : fwd = The forwarder settings used.
389 *********************************************************************/
390 void remember_connection(jb_socket sfd, const struct http_request *http,
391 const struct forward_spec *fwd)
393 unsigned int slot = 0;
394 int free_slot_found = FALSE;
396 assert(sfd != JB_INVALID_SOCKET);
398 if (mark_connection_unused(sfd))
403 privoxy_mutex_lock(&connection_reuse_mutex);
405 /* Find free socket slot. */
406 for (slot = 0; slot < SZ(reusable_connection); slot++)
408 if (reusable_connection[slot].sfd == JB_INVALID_SOCKET)
410 assert(reusable_connection[slot].in_use == 0);
411 log_error(LOG_LEVEL_CONNECT,
412 "Remembering socket %d for %s:%d in slot %d.",
413 sfd, http->host, http->port, slot);
414 free_slot_found = TRUE;
419 if (!free_slot_found)
421 log_error(LOG_LEVEL_CONNECT,
422 "No free slots found to remembering socket for %s:%d. Last slot %d.",
423 http->host, http->port, slot);
424 privoxy_mutex_unlock(&connection_reuse_mutex);
429 assert(NULL != http->host);
430 reusable_connection[slot].host = strdup(http->host);
431 if (NULL == reusable_connection[slot].host)
433 log_error(LOG_LEVEL_FATAL, "Out of memory saving socket.");
435 reusable_connection[slot].sfd = sfd;
436 reusable_connection[slot].port = http->port;
437 reusable_connection[slot].in_use = 0;
438 reusable_connection[slot].timestamp = time(NULL);
441 assert(reusable_connection[slot].gateway_host == NULL);
442 assert(reusable_connection[slot].gateway_port == 0);
443 assert(reusable_connection[slot].forwarder_type == SOCKS_NONE);
444 assert(reusable_connection[slot].forward_host == NULL);
445 assert(reusable_connection[slot].forward_port == 0);
447 reusable_connection[slot].forwarder_type = fwd->type;
448 if (NULL != fwd->gateway_host)
450 reusable_connection[slot].gateway_host = strdup(fwd->gateway_host);
451 if (NULL == reusable_connection[slot].gateway_host)
453 log_error(LOG_LEVEL_FATAL, "Out of memory saving gateway_host.");
458 reusable_connection[slot].gateway_host = NULL;
460 reusable_connection[slot].gateway_port = fwd->gateway_port;
462 if (NULL != fwd->forward_host)
464 reusable_connection[slot].forward_host = strdup(fwd->forward_host);
465 if (NULL == reusable_connection[slot].forward_host)
467 log_error(LOG_LEVEL_FATAL, "Out of memory saving forward_host.");
472 reusable_connection[slot].forward_host = NULL;
474 reusable_connection[slot].forward_port = fwd->forward_port;
476 privoxy_mutex_unlock(&connection_reuse_mutex);
480 /*********************************************************************
482 * Function : mark_connection_closed
484 * Description : Marks a reused connection closed.
485 * Must be called with connection_reuse_mutex locked.
488 * 1 : closed_connection = The connection to mark as closed.
492 *********************************************************************/
493 static void mark_connection_closed(struct reusable_connection *closed_connection)
495 closed_connection->in_use = FALSE;
496 closed_connection->sfd = JB_INVALID_SOCKET;
497 freez(closed_connection->host);
498 closed_connection->port = 0;
499 closed_connection->timestamp = 0;
500 closed_connection->forwarder_type = SOCKS_NONE;
501 freez(closed_connection->gateway_host);
502 closed_connection->gateway_port = 0;
503 freez(closed_connection->forward_host);
504 closed_connection->forward_port = 0;
508 /*********************************************************************
510 * Function : forget_connection
512 * Description : Removes a previously remembered connection from
513 * the list of reusable connections.
516 * 1 : sfd = The socket belonging to the connection in question.
520 *********************************************************************/
521 void forget_connection(jb_socket sfd)
523 unsigned int slot = 0;
525 assert(sfd != JB_INVALID_SOCKET);
527 privoxy_mutex_lock(&connection_reuse_mutex);
529 for (slot = 0; slot < SZ(reusable_connection); slot++)
531 if (reusable_connection[slot].sfd == sfd)
533 assert(reusable_connection[slot].in_use);
535 log_error(LOG_LEVEL_CONNECT,
536 "Forgetting socket %d for %s:%d in slot %d.",
537 sfd, reusable_connection[slot].host,
538 reusable_connection[slot].port, slot);
539 mark_connection_closed(&reusable_connection[slot]);
540 privoxy_mutex_unlock(&connection_reuse_mutex);
546 log_error(LOG_LEVEL_CONNECT,
547 "Socket %d already forgotten or never remembered.", sfd);
549 privoxy_mutex_unlock(&connection_reuse_mutex);
553 /*********************************************************************
555 * Function : connection_destination_matches
557 * Description : Determines whether a remembered connection can
558 * be reused. That is whether the destination and
559 * the forwarding settings match.
562 * 1 : connection = The connection to check.
563 * 2 : http = The destination for the connection.
564 * 3 : fwd = The forwarder settings.
566 * Returns : TRUE for yes, FALSE otherwise.
568 *********************************************************************/
569 static int connection_destination_matches(const struct reusable_connection *connection,
570 const struct http_request *http,
571 const struct forward_spec *fwd)
573 /* XXX: Start of duplicated checks for debugging purposes. */
574 if (strcmpic(connection->host, http->host))
579 if (connection->forwarder_type != fwd->type)
581 log_error(LOG_LEVEL_CONNECT, "Type mismatch: %d %d (%s)",
582 connection->forwarder_type, fwd->type, http->host);
585 if (connection->gateway_port != fwd->gateway_port)
587 log_error(LOG_LEVEL_CONNECT, "Gateway port mismatch: %d %d (%s)",
588 connection->gateway_port, fwd->gateway_port, http->host);
591 if (connection->forward_port != fwd->forward_port)
593 log_error(LOG_LEVEL_CONNECT, "Forward port mismatch: %d %d (%s)",
594 connection->forward_port, fwd->forward_port, http->host);
597 if (connection->port != http->port)
599 log_error(LOG_LEVEL_CONNECT, "Server port mismatch: %d %d (%s)",
600 connection->port, http->port, http->host);
604 /* XXX: End of duplicated checks for debugging purposes. */
606 if ((connection->forwarder_type != fwd->type)
607 || (connection->gateway_port != fwd->gateway_port)
608 || (connection->forward_port != fwd->forward_port)
609 || (connection->port != http->port))
614 if (( (NULL != connection->gateway_host)
615 && (NULL != fwd->gateway_host)
616 && strcmpic(connection->gateway_host, fwd->gateway_host))
617 && (connection->gateway_host != fwd->gateway_host))
619 log_error(LOG_LEVEL_CONNECT, "Gateway mismatch.");
623 if (( (NULL != connection->forward_host)
624 && (NULL != fwd->forward_host)
625 && strcmpic(connection->forward_host, fwd->forward_host))
626 && (connection->forward_host != fwd->forward_host))
628 log_error(LOG_LEVEL_CONNECT, "Forwarding proxy mismatch.");
632 return (!strcmpic(connection->host, http->host));
637 /*********************************************************************
639 * Function : close_unusable_connections
641 * Description : Closes remembered connections that have timed
642 * out or have been closed on the other side.
648 *********************************************************************/
649 static void close_unusable_connections(void)
651 unsigned int slot = 0;
653 for (slot = 0; slot < SZ(reusable_connection); slot++)
655 if (!reusable_connection[slot].in_use
656 && (JB_INVALID_SOCKET != reusable_connection[slot].sfd))
658 time_t time_open = time(NULL) - reusable_connection[slot].timestamp;
660 if (keep_alive_timeout < time_open)
662 log_error(LOG_LEVEL_CONNECT,
663 "The connection to %s:%d in slot %d timed out. "
664 "Closing socket %d. Timeout is: %d.",
665 reusable_connection[slot].host,
666 reusable_connection[slot].port, slot,
667 reusable_connection[slot].sfd, keep_alive_timeout);
668 close_socket(reusable_connection[slot].sfd);
669 mark_connection_closed(&reusable_connection[slot]);
673 if (!socket_is_still_usable(reusable_connection[slot].sfd))
675 log_error(LOG_LEVEL_CONNECT,
676 "The connection to %s:%d in slot %d is no longer usable. "
677 "Closing socket %d.", reusable_connection[slot].host,
678 reusable_connection[slot].port, slot,
679 reusable_connection[slot].sfd);
680 close_socket(reusable_connection[slot].sfd);
681 mark_connection_closed(&reusable_connection[slot]);
689 /*********************************************************************
691 * Function : socket_is_still_usable
693 * Description : Decides whether or not an open socket is still usable.
696 * 1 : sfd = The socket to check.
698 * Returns : TRUE for yes, otherwise FALSE.
700 *********************************************************************/
701 static int socket_is_still_usable(jb_socket sfd)
705 struct pollfd poll_fd[1];
707 memset(poll_fd, 0, sizeof(poll_fd));
709 poll_fd[0].events = POLLIN;
711 poll_result = poll(poll_fd, 1, 0);
713 if (-1 != poll_result)
715 return !(poll_fd[0].revents & POLLIN);
719 log_error(LOG_LEVEL_CONNECT, "Polling socket %d failed.", sfd);
724 struct timeval timeout;
726 int socket_is_alive = 0;
728 memset(&timeout, '\0', sizeof(timeout));
729 FD_ZERO(&readable_fds);
730 FD_SET(sfd, &readable_fds);
732 ret = select((int)sfd+1, &readable_fds, NULL, NULL, &timeout);
735 log_error(LOG_LEVEL_ERROR, "select() failed!: %E");
739 * XXX: I'm not sure why !FD_ISSET() works,
740 * but apparently it does.
742 socket_is_alive = !FD_ISSET(sfd, &readable_fds);
744 return socket_is_alive;
745 #endif /* def HAVE_POLL */
749 /*********************************************************************
751 * Function : get_reusable_connection
753 * Description : Returns an open socket to a previously remembered
754 * open connection (if there is one).
757 * 1 : http = The destination for the connection.
758 * 2 : fwd = The forwarder settings.
760 * Returns : JB_INVALID_SOCKET => No reusable connection found,
761 * otherwise a usable socket.
763 *********************************************************************/
764 static jb_socket get_reusable_connection(const struct http_request *http,
765 const struct forward_spec *fwd)
767 jb_socket sfd = JB_INVALID_SOCKET;
768 unsigned int slot = 0;
770 privoxy_mutex_lock(&connection_reuse_mutex);
772 close_unusable_connections();
774 for (slot = 0; slot < SZ(reusable_connection); slot++)
776 if (!reusable_connection[slot].in_use
777 && (JB_INVALID_SOCKET != reusable_connection[slot].sfd))
779 if (connection_destination_matches(&reusable_connection[slot], http, fwd))
781 reusable_connection[slot].in_use = TRUE;
782 sfd = reusable_connection[slot].sfd;
783 log_error(LOG_LEVEL_CONNECT,
784 "Found reusable socket %d for %s:%d in slot %d.",
785 sfd, reusable_connection[slot].host, reusable_connection[slot].port, slot);
791 privoxy_mutex_unlock(&connection_reuse_mutex);
798 /*********************************************************************
800 * Function : mark_connection_unused
802 * Description : Gives a remembered connection free for reuse.
805 * 1 : sfd = The socket belonging to the connection in question.
807 * Returns : TRUE => Socket found and marked as unused.
808 * FALSE => Socket not found.
810 *********************************************************************/
811 static int mark_connection_unused(jb_socket sfd)
813 unsigned int slot = 0;
814 int socket_found = FALSE;
816 assert(sfd != JB_INVALID_SOCKET);
818 privoxy_mutex_lock(&connection_reuse_mutex);
820 for (slot = 0; slot < SZ(reusable_connection); slot++)
822 if (reusable_connection[slot].sfd == sfd)
824 assert(reusable_connection[slot].in_use);
826 log_error(LOG_LEVEL_CONNECT,
827 "Marking open socket %d for %s:%d in slot %d as unused.",
828 sfd, reusable_connection[slot].host,
829 reusable_connection[slot].port, slot);
830 reusable_connection[slot].in_use = 0;
831 reusable_connection[slot].timestamp = time(NULL);
836 privoxy_mutex_unlock(&connection_reuse_mutex);
843 /*********************************************************************
845 * Function : set_keep_alive_timeout
847 * Description : Sets the timeout after which open
848 * connections will no longer be reused.
851 * 1 : timeout = The timeout in seconds.
855 *********************************************************************/
856 void set_keep_alive_timeout(int timeout)
858 keep_alive_timeout = timeout;
860 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
863 /*********************************************************************
865 * Function : forwarded_connect
867 * Description : Connect to a specified web server, possibly via
868 * a HTTP proxy and/or a SOCKS proxy.
871 * 1 : fwd = the proxies to use when connecting.
872 * 2 : http = the http request and apropos headers
873 * 3 : csp = Current client state (buffers, headers, etc...)
875 * Returns : JB_INVALID_SOCKET => failure, else it is the socket file descriptor.
877 *********************************************************************/
878 jb_socket forwarded_connect(const struct forward_spec * fwd,
879 struct http_request *http,
880 struct client_state *csp)
882 const char * dest_host;
884 jb_socket sfd = JB_INVALID_SOCKET;
886 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
887 sfd = get_reusable_connection(http, fwd);
888 if (JB_INVALID_SOCKET == sfd)
890 log_error(LOG_LEVEL_CONNECT,
891 "No reusable socket for %s:%d found. Opening a new one.",
892 http->host, http->port);
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.");
938 /*********************************************************************
940 * Function : socks4_connect
942 * Description : Connect to the SOCKS server, and connect through
943 * it to the specified server. This handles
944 * all the SOCKS negotiation, and returns a file
945 * descriptor for a socket which can be treated as a
946 * normal (non-SOCKS) socket.
948 * Logged error messages are saved to csp->error_message
949 * and later reused by error_response() for the CGI
950 * message. strdup allocation failures are handled there.
953 * 1 : fwd = Specifies the SOCKS proxy to use.
954 * 2 : target_host = The final server to connect to.
955 * 3 : target_port = The final port to connect to.
956 * 4 : csp = Current client state (buffers, headers, etc...)
958 * Returns : JB_INVALID_SOCKET => failure, else a socket file descriptor.
960 *********************************************************************/
961 static jb_socket socks4_connect(const struct forward_spec * fwd,
962 const char * target_host,
964 struct client_state *csp)
966 unsigned int web_server_addr;
967 char buf[BUFFER_SIZE];
968 struct socks_op *c = (struct socks_op *)buf;
969 struct socks_reply *s = (struct socks_reply *)buf;
976 if ((fwd->gateway_host == NULL) || (*fwd->gateway_host == '\0'))
978 /* XXX: Shouldn't the config file parser prevent this? */
979 errstr = "NULL gateway host specified.";
983 if (fwd->gateway_port <= 0)
985 errstr = "invalid gateway port specified.";
991 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
992 csp->error_message = strdup(errstr);
994 return(JB_INVALID_SOCKET);
997 /* build a socks request for connection to the web server */
999 strlcpy(&(c->userid), socks_userid, sizeof(buf) - sizeof(struct socks_op));
1001 csiz = sizeof(*c) + sizeof(socks_userid) - sizeof(c->userid) - sizeof(c->padding);
1006 web_server_addr = resolve_hostname_to_ip(target_host);
1007 if (web_server_addr == INADDR_NONE)
1009 errstr = "could not resolve target host";
1010 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s %s", errstr, target_host);
1015 web_server_addr = htonl(web_server_addr);
1019 web_server_addr = 0x00000001;
1020 n = csiz + strlen(target_host) + 1;
1021 if (n > sizeof(buf))
1024 errstr = "buffer cbuf too small.";
1025 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
1030 strlcpy(buf + csiz, target_host, sizeof(buf) - sizeof(struct socks_op) - csiz);
1032 * What we forward to the socks4a server should have the
1033 * size of socks_op, plus the length of the userid plus
1034 * its \0 byte (which we don't have to add because the
1035 * first byte of the userid is counted twice as it's also
1036 * part of sock_op) minus the padding bytes (which are part
1037 * of the userid as well), plus the length of the target_host
1038 * (which is stored csiz bytes after the beginning of the buffer),
1039 * plus another \0 byte.
1041 assert(n == sizeof(struct socks_op) + strlen(&(c->userid)) - sizeof(c->padding) + strlen(buf + csiz) + 1);
1046 /* Should never get here */
1047 log_error(LOG_LEVEL_FATAL,
1048 "socks4_connect: SOCKS4 impossible internal error - bad SOCKS type.");
1050 return(JB_INVALID_SOCKET);
1055 csp->error_message = strdup(errstr);
1056 return(JB_INVALID_SOCKET);
1061 c->dstport[0] = (unsigned char)((target_port >> 8 ) & 0xff);
1062 c->dstport[1] = (unsigned char)((target_port ) & 0xff);
1063 c->dstip[0] = (unsigned char)((web_server_addr >> 24 ) & 0xff);
1064 c->dstip[1] = (unsigned char)((web_server_addr >> 16 ) & 0xff);
1065 c->dstip[2] = (unsigned char)((web_server_addr >> 8 ) & 0xff);
1066 c->dstip[3] = (unsigned char)((web_server_addr ) & 0xff);
1068 /* pass the request to the socks server */
1069 sfd = connect_to(fwd->gateway_host, fwd->gateway_port, csp);
1071 if (sfd == JB_INVALID_SOCKET)
1074 * XXX: connect_to should fill in the exact reason.
1075 * Most likely resolving the IP of the forwarder failed.
1077 errstr = "connect_to failed: see logfile for details";
1080 else if (write_socket(sfd, (char *)c, csiz))
1082 errstr = "SOCKS4 negotiation write failed.";
1083 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
1087 else if (read_socket(sfd, buf, sizeof(buf)) != sizeof(*s))
1089 errstr = "SOCKS4 negotiation read failed.";
1090 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
1097 csp->error_message = strdup(errstr);
1098 return(JB_INVALID_SOCKET);
1103 case SOCKS_REQUEST_GRANTED:
1106 case SOCKS_REQUEST_REJECT:
1107 errstr = "SOCKS request rejected or failed.";
1110 case SOCKS_REQUEST_IDENT_FAILED:
1111 errstr = "SOCKS request rejected because "
1112 "SOCKS server cannot connect to identd on the client.";
1115 case SOCKS_REQUEST_IDENT_CONFLICT:
1116 errstr = "SOCKS request rejected because "
1117 "the client program and identd report "
1118 "different user-ids.";
1123 snprintf(buf, sizeof(buf),
1124 "SOCKS request rejected for reason code %d.", s->cd);
1128 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
1129 csp->error_message = strdup(errstr);
1132 return(JB_INVALID_SOCKET);
1136 /*********************************************************************
1138 * Function : translate_socks5_error
1140 * Description : Translates a SOCKS errors to a string.
1143 * 1 : socks_error = The error code to translate.
1145 * Returns : The string translation.
1147 *********************************************************************/
1148 static const char *translate_socks5_error(int socks_error)
1150 switch (socks_error)
1152 /* XXX: these should be more descriptive */
1153 case SOCKS5_REQUEST_FAILED:
1154 return "SOCKS5 request failed";
1155 case SOCKS5_REQUEST_DENIED:
1156 return "SOCKS5 request denied";
1157 case SOCKS5_REQUEST_NETWORK_UNREACHABLE:
1158 return "SOCKS5 network unreachable";
1159 case SOCKS5_REQUEST_HOST_UNREACHABLE:
1160 return "SOCKS5 host unreachable";
1161 case SOCKS5_REQUEST_CONNECTION_REFUSED:
1162 return "SOCKS5 connection refused";
1163 case SOCKS5_REQUEST_TTL_EXPIRED:
1164 return "SOCKS5 TTL expired";
1165 case SOCKS5_REQUEST_PROTOCOL_ERROR:
1166 return "SOCKS5 client protocol error";
1167 case SOCKS5_REQUEST_BAD_ADDRESS_TYPE:
1168 return "SOCKS5 domain names unsupported";
1169 case SOCKS5_REQUEST_GRANTED:
1170 return "everything's peachy";
1172 return "SOCKS5 negotiation protocol error";
1176 /*********************************************************************
1178 * Function : socks5_connect
1180 * Description : Connect to the SOCKS server, and connect through
1181 * it to the specified server. This handles
1182 * all the SOCKS negotiation, and returns a file
1183 * descriptor for a socket which can be treated as a
1184 * normal (non-SOCKS) socket.
1187 * 1 : fwd = Specifies the SOCKS proxy to use.
1188 * 2 : target_host = The final server to connect to.
1189 * 3 : target_port = The final port to connect to.
1190 * 4 : csp = Current client state (buffers, headers, etc...)
1192 * Returns : JB_INVALID_SOCKET => failure, else a socket file descriptor.
1194 *********************************************************************/
1195 static jb_socket socks5_connect(const struct forward_spec *fwd,
1196 const char *target_host,
1198 struct client_state *csp)
1203 size_t client_pos = 0;
1204 int server_size = 0;
1207 const char *errstr = NULL;
1209 assert(fwd->gateway_host);
1210 if ((fwd->gateway_host == NULL) || (*fwd->gateway_host == '\0'))
1212 errstr = "NULL gateway host specified";
1216 if (fwd->gateway_port <= 0)
1219 * XXX: currently this can't happen because in
1220 * case of invalid gateway ports we use the defaults.
1221 * Of course we really shouldn't do that.
1223 errstr = "invalid gateway port specified";
1227 hostlen = strlen(target_host);
1230 errstr = "target host name is longer than 255 characters";
1234 if (fwd->type != SOCKS_5)
1236 /* Should never get here */
1237 log_error(LOG_LEVEL_FATAL,
1238 "SOCKS5 impossible internal error - bad SOCKS type");
1245 assert(errstr != NULL);
1246 log_error(LOG_LEVEL_CONNECT, "socks5_connect: %s", errstr);
1247 csp->error_message = strdup(errstr);
1248 return(JB_INVALID_SOCKET);
1251 /* pass the request to the socks server */
1252 sfd = connect_to(fwd->gateway_host, fwd->gateway_port, csp);
1254 if (sfd == JB_INVALID_SOCKET)
1256 errstr = "socks5 server unreachable";
1257 log_error(LOG_LEVEL_CONNECT, "socks5_connect: %s", errstr);
1258 csp->error_message = strdup(errstr);
1259 return(JB_INVALID_SOCKET);
1263 cbuf[client_pos++] = '\x05'; /* Version */
1264 cbuf[client_pos++] = '\x01'; /* One authentication method supported */
1265 cbuf[client_pos++] = '\x00'; /* The no authentication authentication method */
1267 if (write_socket(sfd, cbuf, client_pos))
1269 errstr = "SOCKS5 negotiation write failed";
1270 csp->error_message = strdup(errstr);
1271 log_error(LOG_LEVEL_CONNECT, "%s", errstr);
1273 return(JB_INVALID_SOCKET);
1276 if (read_socket(sfd, sbuf, sizeof(sbuf)) != 2)
1278 errstr = "SOCKS5 negotiation read failed";
1282 if (!err && (sbuf[0] != '\x05'))
1284 errstr = "SOCKS5 negotiation protocol version error";
1288 if (!err && (sbuf[1] == '\xff'))
1290 errstr = "SOCKS5 authentication required";
1294 if (!err && (sbuf[1] != '\x00'))
1296 errstr = "SOCKS5 negotiation protocol error";
1302 assert(errstr != NULL);
1303 log_error(LOG_LEVEL_CONNECT, "socks5_connect: %s", errstr);
1304 csp->error_message = strdup(errstr);
1307 return(JB_INVALID_SOCKET);
1311 cbuf[client_pos++] = '\x05'; /* Version */
1312 cbuf[client_pos++] = '\x01'; /* TCP connect */
1313 cbuf[client_pos++] = '\x00'; /* Reserved, must be 0x00 */
1314 cbuf[client_pos++] = '\x03'; /* Address is domain name */
1315 cbuf[client_pos++] = (char)(hostlen & 0xffu);
1316 assert(sizeof(cbuf) - client_pos > 255);
1317 /* Using strncpy because we really want the nul byte padding. */
1318 strncpy(cbuf + client_pos, target_host, sizeof(cbuf) - client_pos);
1319 client_pos += (hostlen & 0xffu);
1320 cbuf[client_pos++] = (char)((target_port >> 8) & 0xff);
1321 cbuf[client_pos++] = (char)((target_port ) & 0xff);
1323 if (write_socket(sfd, cbuf, client_pos))
1325 errstr = "SOCKS5 negotiation read failed";
1326 csp->error_message = strdup(errstr);
1327 log_error(LOG_LEVEL_CONNECT, "%s", errstr);
1330 return(JB_INVALID_SOCKET);
1333 server_size = read_socket(sfd, sbuf, sizeof(sbuf));
1334 if (server_size < 3)
1336 errstr = "SOCKS5 negotiation read failed";
1339 else if (server_size > 20)
1341 /* This is somewhat unexpected but doesn't realy matter. */
1342 log_error(LOG_LEVEL_CONNECT, "socks5_connect: read %d bytes "
1343 "from socks server. Would have accepted up to %d.",
1344 server_size, sizeof(sbuf));
1347 if (!err && (sbuf[0] != '\x05'))
1349 errstr = "SOCKS5 negotiation protocol version error";
1353 if (!err && (sbuf[2] != '\x00'))
1355 errstr = "SOCKS5 negotiation protocol error";
1361 if (sbuf[1] == SOCKS5_REQUEST_GRANTED)
1365 errstr = translate_socks5_error(sbuf[1]);
1369 assert(errstr != NULL);
1370 csp->error_message = strdup(errstr);
1371 log_error(LOG_LEVEL_CONNECT, "socks5_connect: %s", errstr);
1375 return(JB_INVALID_SOCKET);