1 const char gateway_rcs[] = "$Id: gateway.c,v 1.43 2008/11/13 09:15:51 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 1.43 2008/11/13 09:15:51 fabiankeil
38 * Make keep_alive_timeout static.
40 * Revision 1.42 2008/11/13 09:08:42 fabiankeil
41 * Add new config option: keep-alive-timeout.
43 * Revision 1.41 2008/11/08 15:29:58 fabiankeil
44 * Unify two debug messages.
46 * Revision 1.40 2008/11/08 15:14:05 fabiankeil
47 * Fix duplicated debugging check.
49 * Revision 1.39 2008/10/25 11:33:01 fabiankeil
50 * Remove already out-commented line left over from debugging.
52 * Revision 1.38 2008/10/24 17:33:00 fabiankeil
53 * - Tone the "keep-alive support is experimental" warning
54 * down a bit as hackish 0-chunk detection has been
55 * implemented recently.
56 * - Only show the "ndef HAVE_POLL" warning once on start-up.
58 * Revision 1.37 2008/10/23 17:40:53 fabiankeil
59 * Fix forget_connection() and mark_connection_unused(),
60 * which would both under certain circumstances access
61 * reusable_connection[MAX_REUSABLE_CONNECTIONS]. Oops.
63 * Revision 1.36 2008/10/18 19:49:15 fabiankeil
64 * - Factor close_unusable_connections() out of
65 * get_reusable_connection() to make sure we really check
66 * all the remembered connections, not just the ones before
67 * the next reusable one.
68 * - Plug two file descriptor leaks. Internally marking
69 * connections as closed doesn't cut it.
71 * Revision 1.35 2008/10/17 17:12:01 fabiankeil
72 * In socket_is_still_usable(), use select()
73 * and FD_ISSET() if poll() isn't available.
75 * Revision 1.34 2008/10/17 17:07:13 fabiankeil
76 * Add preliminary timeout support.
78 * Revision 1.33 2008/10/16 16:34:21 fabiankeil
79 * Fix two gcc44 warnings.
81 * Revision 1.32 2008/10/16 16:27:22 fabiankeil
82 * Fix compiler warning.
84 * Revision 1.31 2008/10/16 07:31:11 fabiankeil
85 * - Factor socket_is_still_usable() out of get_reusable_connection().
86 * - If poll() isn't available, show a warning and assume the socket
89 * Revision 1.30 2008/10/13 17:31:03 fabiankeil
90 * If a remembered connection is no longer usable and
91 * has been marked closed, don't bother checking if the
92 * destination matches.
94 * Revision 1.29 2008/10/11 16:59:41 fabiankeil
95 * Add missing dots for two log messages.
97 * Revision 1.28 2008/10/09 18:21:41 fabiankeil
98 * Flush work-in-progress changes to keep outgoing connections
99 * alive where possible. Incomplete and mostly #ifdef'd out.
101 * Revision 1.27 2008/09/27 15:05:51 fabiankeil
102 * Return only once in forwarded_connect().
104 * Revision 1.26 2008/08/18 17:42:06 fabiankeil
105 * Fix typo in macro name.
107 * Revision 1.25 2008/02/07 18:09:46 fabiankeil
109 * - make the buffers quite a bit smaller.
110 * - properly report "socks5 server unreachable" failures.
111 * - let strncpy() use the whole buffer. Using a length of 0xffu wasn't actually
112 * wrong, but requires too much thinking as it doesn't depend on the buffer size.
113 * - log a message if the socks5 server sends more data than expected.
114 * - add some assertions and comments.
116 * Revision 1.24 2008/02/04 14:56:29 fabiankeil
117 * - Fix a compiler warning.
118 * - Stop assuming that htonl(INADDR_NONE) equals INADDR_NONE.
120 * Revision 1.23 2008/02/04 13:11:35 fabiankeil
121 * Remember the cause of the SOCKS5 error for the CGI message.
123 * Revision 1.22 2008/02/03 13:46:15 fabiankeil
124 * Add SOCKS5 support. Patch #1862863 by Eric M. Hopper with minor changes.
126 * Revision 1.21 2007/07/28 12:30:03 fabiankeil
127 * Modified patch from Song Weijia (#1762559) to
128 * fix socks requests on big-endian platforms.
130 * Revision 1.20 2007/05/14 10:23:48 fabiankeil
131 * - Use strlcpy() instead of strcpy().
132 * - Use the same buffer for socks requests and socks responses.
133 * - Fix bogus warning about web_server_addr being used uninitialized.
135 * Revision 1.19 2007/01/25 14:09:45 fabiankeil
136 * - Save errors in socks4_connect() to csp->error_message.
137 * - Silence some gcc43 warnings, hopefully the right way.
139 * Revision 1.18 2006/07/18 14:48:46 david__schmidt
140 * Reorganizing the repository: swapping out what was HEAD (the old 3.1 branch)
141 * with what was really the latest development (the v_3_0_branch branch)
143 * Revision 1.16 2002/05/12 21:36:29 jongfoster
144 * Correcting function comments
146 * Revision 1.15 2002/03/26 22:29:54 swa
147 * we have a new homepage!
149 * Revision 1.14 2002/03/24 13:25:43 swa
150 * name change related issues
152 * Revision 1.13 2002/03/13 00:29:59 jongfoster
155 * Revision 1.12 2002/03/09 20:03:52 jongfoster
156 * - Making various functions return int rather than size_t.
157 * (Undoing a recent change). Since size_t is unsigned on
158 * Windows, functions like read_socket that return -1 on
159 * error cannot return a size_t.
161 * THIS WAS A MAJOR BUG - it caused frequent, unpredictable
162 * crashes, and also frequently caused JB to jump to 100%
163 * CPU and stay there. (Because it thought it had just
164 * read ((unsigned)-1) == 4Gb of data...)
166 * - The signature of write_socket has changed, it now simply
167 * returns success=0/failure=nonzero.
169 * - Trying to get rid of a few warnings --with-debug on
170 * Windows, I've introduced a new type "jb_socket". This is
171 * used for the socket file descriptors. On Windows, this
172 * is SOCKET (a typedef for unsigned). Everywhere else, it's
173 * an int. The error value can't be -1 any more, so it's
174 * now JB_INVALID_SOCKET (which is -1 on UNIX, and in
175 * Windows it maps to the #define INVALID_SOCKET.)
177 * - The signature of bind_port has changed.
179 * Revision 1.11 2002/03/08 17:46:04 jongfoster
180 * Fixing int/size_t warnings
182 * Revision 1.10 2002/03/07 03:50:19 oes
183 * - Improved handling of failed DNS lookups
184 * - Fixed compiler warnings
186 * Revision 1.9 2001/10/25 03:40:48 david__schmidt
187 * Change in porting tactics: OS/2's EMX porting layer doesn't allow multiple
188 * threads to call select() simultaneously. So, it's time to do a real, live,
189 * native OS/2 port. See defines for __EMX__ (the porting layer) vs. __OS2__
190 * (native). Both versions will work, but using __OS2__ offers multi-threading.
192 * Revision 1.8 2001/09/13 20:10:12 jongfoster
193 * Fixing missing #include under Windows
195 * Revision 1.7 2001/09/12 17:58:26 steudten
197 * add #include <string.h>
199 * Revision 1.6 2001/09/10 10:41:16 oes
200 * Added #include in.h
202 * Revision 1.5 2001/07/29 18:47:57 jongfoster
203 * Adding missing #include project.h
205 * Revision 1.4 2001/07/24 12:47:06 oes
206 * Applied BeOS support update by Eugenia
208 * Revision 1.3 2001/06/09 10:55:28 jongfoster
209 * Changing BUFSIZ ==> BUFFER_SIZE
211 * Revision 1.2 2001/06/07 23:11:38 jongfoster
212 * Removing gateways[] list - no longer used.
213 * Replacing function pointer in struct gateway with a directly
214 * called function forwarded_connect(), which can do the common
215 * task of deciding whether to connect to the web server or HTTP
217 * Replacing struct gateway with struct forward_spec
218 * Fixing bug with SOCKS4A and HTTP proxy server in combination.
219 * It was a bug which led to the connection being made to the web
220 * server rather than the HTTP proxy, and also a buffer overrun.
222 * Revision 1.1.1.1 2001/05/15 13:58:54 oes
223 * Initial import of version 2.9.3 source tree
226 *********************************************************************/
232 #include <sys/types.h>
235 #include <netinet/in.h>
243 #include <winsock2.h>
244 #endif /* def _WIN32 */
248 #endif /* def __BEOS__ */
252 #endif /* def __OS2__ */
257 #include "jbsockets.h"
259 #include "miscutil.h"
260 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
263 #include <sys/poll.h>
266 #endif /* def __GLIBC__ */
267 #endif /* HAVE_POLL */
268 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
270 const char gateway_h_rcs[] = GATEWAY_H_VERSION;
272 static jb_socket socks4_connect(const struct forward_spec * fwd,
273 const char * target_host,
275 struct client_state *csp);
277 static jb_socket socks5_connect(const struct forward_spec *fwd,
278 const char *target_host,
280 struct client_state *csp);
283 #define SOCKS_REQUEST_GRANTED 90
284 #define SOCKS_REQUEST_REJECT 91
285 #define SOCKS_REQUEST_IDENT_FAILED 92
286 #define SOCKS_REQUEST_IDENT_CONFLICT 93
288 #define SOCKS5_REQUEST_GRANTED 0
289 #define SOCKS5_REQUEST_FAILED 1
290 #define SOCKS5_REQUEST_DENIED 2
291 #define SOCKS5_REQUEST_NETWORK_UNREACHABLE 3
292 #define SOCKS5_REQUEST_HOST_UNREACHABLE 4
293 #define SOCKS5_REQUEST_CONNECTION_REFUSED 5
294 #define SOCKS5_REQUEST_TTL_EXPIRED 6
295 #define SOCKS5_REQUEST_PROTOCOL_ERROR 7
296 #define SOCKS5_REQUEST_BAD_ADDRESS_TYPE 8
298 /* structure of a socks client operation */
300 unsigned char vn; /* socks version number */
301 unsigned char cd; /* command code */
302 unsigned char dstport[2]; /* destination port */
303 unsigned char dstip[4]; /* destination address */
304 char userid; /* first byte of userid */
305 char padding[3]; /* make sure sizeof(struct socks_op) is endian-independent. */
306 /* more bytes of the userid follow, terminated by a NULL */
309 /* structure of a socks server reply */
311 unsigned char vn; /* socks version number */
312 unsigned char cd; /* command code */
313 unsigned char dstport[2]; /* destination port */
314 unsigned char dstip[4]; /* destination address */
317 static const char socks_userid[] = "anonymous";
319 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
321 #define MAX_REUSABLE_CONNECTIONS 100
322 static int keep_alive_timeout = DEFAULT_KEEP_ALIVE_TIMEOUT;
324 struct reusable_connection
339 static struct reusable_connection reusable_connection[MAX_REUSABLE_CONNECTIONS];
341 static int mark_connection_unused(jb_socket sfd);
342 static void mark_connection_closed(struct reusable_connection *closed_connection);
343 static int socket_is_still_usable(jb_socket sfd);
346 /*********************************************************************
348 * Function : initialize_reusable_connections
350 * Description : Initializes the reusable_connection structures.
351 * Must be called with connection_reuse_mutex locked.
357 *********************************************************************/
358 extern void initialize_reusable_connections(void)
360 unsigned int slot = 0;
362 log_error(LOG_LEVEL_INFO,
363 "Support for 'Connection: keep-alive' is experimental."
365 " Detecting already dead connections might not work"
366 " correctly on your platform."
367 #endif /* ndef HAVE_POLL */
370 for (slot = 0; slot < SZ(reusable_connection); slot++)
372 mark_connection_closed(&reusable_connection[slot]);
375 log_error(LOG_LEVEL_CONNECT, "Initialized %d socket slots.", slot);
379 /*********************************************************************
381 * Function : remember_connection
383 * Description : Remembers a connection for reuse later on.
386 * 1 : sfd = Open socket to remember.
387 * 2 : http = The destination for the connection.
388 * 3 : fwd = The forwarder settings used.
392 *********************************************************************/
393 void remember_connection(jb_socket sfd, const struct http_request *http,
394 const struct forward_spec *fwd)
396 unsigned int slot = 0;
397 int free_slot_found = FALSE;
399 assert(sfd != JB_INVALID_SOCKET);
401 if (mark_connection_unused(sfd))
406 privoxy_mutex_lock(&connection_reuse_mutex);
408 /* Find free socket slot. */
409 for (slot = 0; slot < SZ(reusable_connection); slot++)
411 if (reusable_connection[slot].sfd == JB_INVALID_SOCKET)
413 assert(reusable_connection[slot].in_use == 0);
414 log_error(LOG_LEVEL_CONNECT,
415 "Remembering socket %d for %s:%d in slot %d.",
416 sfd, http->host, http->port, slot);
417 free_slot_found = TRUE;
422 if (!free_slot_found)
424 log_error(LOG_LEVEL_CONNECT,
425 "No free slots found to remembering socket for %s:%d. Last slot %d.",
426 http->host, http->port, slot);
427 privoxy_mutex_unlock(&connection_reuse_mutex);
432 assert(NULL != http->host);
433 reusable_connection[slot].host = strdup(http->host);
434 if (NULL == reusable_connection[slot].host)
436 log_error(LOG_LEVEL_FATAL, "Out of memory saving socket.");
438 reusable_connection[slot].sfd = sfd;
439 reusable_connection[slot].port = http->port;
440 reusable_connection[slot].in_use = 0;
441 reusable_connection[slot].timestamp = time(NULL);
444 assert(reusable_connection[slot].gateway_host == NULL);
445 assert(reusable_connection[slot].gateway_port == 0);
446 assert(reusable_connection[slot].forwarder_type == SOCKS_NONE);
447 assert(reusable_connection[slot].forward_host == NULL);
448 assert(reusable_connection[slot].forward_port == 0);
450 reusable_connection[slot].forwarder_type = fwd->type;
451 if (NULL != fwd->gateway_host)
453 reusable_connection[slot].gateway_host = strdup(fwd->gateway_host);
454 if (NULL == reusable_connection[slot].gateway_host)
456 log_error(LOG_LEVEL_FATAL, "Out of memory saving gateway_host.");
461 reusable_connection[slot].gateway_host = NULL;
463 reusable_connection[slot].gateway_port = fwd->gateway_port;
465 if (NULL != fwd->forward_host)
467 reusable_connection[slot].forward_host = strdup(fwd->forward_host);
468 if (NULL == reusable_connection[slot].forward_host)
470 log_error(LOG_LEVEL_FATAL, "Out of memory saving forward_host.");
475 reusable_connection[slot].forward_host = NULL;
477 reusable_connection[slot].forward_port = fwd->forward_port;
479 privoxy_mutex_unlock(&connection_reuse_mutex);
483 /*********************************************************************
485 * Function : mark_connection_closed
487 * Description : Marks a reused connection closed.
488 * Must be called with connection_reuse_mutex locked.
491 * 1 : closed_connection = The connection to mark as closed.
495 *********************************************************************/
496 static void mark_connection_closed(struct reusable_connection *closed_connection)
498 closed_connection->in_use = FALSE;
499 closed_connection->sfd = JB_INVALID_SOCKET;
500 freez(closed_connection->host);
501 closed_connection->port = 0;
502 closed_connection->timestamp = 0;
503 closed_connection->forwarder_type = SOCKS_NONE;
504 freez(closed_connection->gateway_host);
505 closed_connection->gateway_port = 0;
506 freez(closed_connection->forward_host);
507 closed_connection->forward_port = 0;
511 /*********************************************************************
513 * Function : forget_connection
515 * Description : Removes a previously remembered connection from
516 * the list of reusable connections.
519 * 1 : sfd = The socket belonging to the connection in question.
523 *********************************************************************/
524 void forget_connection(jb_socket sfd)
526 unsigned int slot = 0;
528 assert(sfd != JB_INVALID_SOCKET);
530 privoxy_mutex_lock(&connection_reuse_mutex);
532 for (slot = 0; slot < SZ(reusable_connection); slot++)
534 if (reusable_connection[slot].sfd == sfd)
536 assert(reusable_connection[slot].in_use);
538 log_error(LOG_LEVEL_CONNECT,
539 "Forgetting socket %d for %s:%d in slot %d.",
540 sfd, reusable_connection[slot].host,
541 reusable_connection[slot].port, slot);
542 mark_connection_closed(&reusable_connection[slot]);
543 privoxy_mutex_unlock(&connection_reuse_mutex);
549 log_error(LOG_LEVEL_CONNECT,
550 "Socket %d already forgotten or never remembered.", sfd);
552 privoxy_mutex_unlock(&connection_reuse_mutex);
556 /*********************************************************************
558 * Function : connection_destination_matches
560 * Description : Determines whether a remembered connection can
561 * be reused. That is whether the destination and
562 * the forwarding settings match.
565 * 1 : connection = The connection to check.
566 * 2 : http = The destination for the connection.
567 * 3 : fwd = The forwarder settings.
569 * Returns : TRUE for yes, FALSE otherwise.
571 *********************************************************************/
572 static int connection_destination_matches(const struct reusable_connection *connection,
573 const struct http_request *http,
574 const struct forward_spec *fwd)
576 /* XXX: Start of duplicated checks for debugging purposes. */
577 if (strcmpic(connection->host, http->host))
582 if (connection->forwarder_type != fwd->type)
584 log_error(LOG_LEVEL_CONNECT, "Type mismatch: %d %d (%s)",
585 connection->forwarder_type, fwd->type, http->host);
588 if (connection->gateway_port != fwd->gateway_port)
590 log_error(LOG_LEVEL_CONNECT, "Gateway port mismatch: %d %d (%s)",
591 connection->gateway_port, fwd->gateway_port, http->host);
594 if (connection->forward_port != fwd->forward_port)
596 log_error(LOG_LEVEL_CONNECT, "Forward port mismatch: %d %d (%s)",
597 connection->forward_port, fwd->forward_port, http->host);
600 if (connection->port != http->port)
602 log_error(LOG_LEVEL_CONNECT, "Server port mismatch: %d %d (%s)",
603 connection->port, http->port, http->host);
607 /* XXX: End of duplicated checks for debugging purposes. */
609 if ((connection->forwarder_type != fwd->type)
610 || (connection->gateway_port != fwd->gateway_port)
611 || (connection->forward_port != fwd->forward_port)
612 || (connection->port != http->port))
617 if (( (NULL != connection->gateway_host)
618 && (NULL != fwd->gateway_host)
619 && strcmpic(connection->gateway_host, fwd->gateway_host))
620 && (connection->gateway_host != fwd->gateway_host))
622 log_error(LOG_LEVEL_CONNECT, "Gateway mismatch.");
626 if (( (NULL != connection->forward_host)
627 && (NULL != fwd->forward_host)
628 && strcmpic(connection->forward_host, fwd->forward_host))
629 && (connection->forward_host != fwd->forward_host))
631 log_error(LOG_LEVEL_CONNECT, "Forwarding proxy mismatch.");
635 return (!strcmpic(connection->host, http->host));
640 /*********************************************************************
642 * Function : close_unusable_connections
644 * Description : Closes remembered connections that have timed
645 * out or have been closed on the other side.
651 *********************************************************************/
652 static void close_unusable_connections(void)
654 unsigned int slot = 0;
656 for (slot = 0; slot < SZ(reusable_connection); slot++)
658 if (!reusable_connection[slot].in_use
659 && (JB_INVALID_SOCKET != reusable_connection[slot].sfd))
661 time_t time_open = time(NULL) - reusable_connection[slot].timestamp;
663 if (keep_alive_timeout < time_open)
665 log_error(LOG_LEVEL_CONNECT,
666 "The connection to %s:%d in slot %d timed out. "
667 "Closing socket %d. Timeout is: %d.",
668 reusable_connection[slot].host,
669 reusable_connection[slot].port, slot,
670 reusable_connection[slot].sfd, keep_alive_timeout);
671 close_socket(reusable_connection[slot].sfd);
672 mark_connection_closed(&reusable_connection[slot]);
676 if (!socket_is_still_usable(reusable_connection[slot].sfd))
678 log_error(LOG_LEVEL_CONNECT,
679 "The connection to %s:%d in slot %d is no longer usable. "
680 "Closing socket %d.", reusable_connection[slot].host,
681 reusable_connection[slot].port, slot,
682 reusable_connection[slot].sfd);
683 close_socket(reusable_connection[slot].sfd);
684 mark_connection_closed(&reusable_connection[slot]);
692 /*********************************************************************
694 * Function : socket_is_still_usable
696 * Description : Decides whether or not an open socket is still usable.
699 * 1 : sfd = The socket to check.
701 * Returns : TRUE for yes, otherwise FALSE.
703 *********************************************************************/
704 static int socket_is_still_usable(jb_socket sfd)
708 struct pollfd poll_fd[1];
710 memset(poll_fd, 0, sizeof(poll_fd));
712 poll_fd[0].events = POLLIN;
714 poll_result = poll(poll_fd, 1, 0);
716 if (-1 != poll_result)
718 return !(poll_fd[0].revents & POLLIN);
722 log_error(LOG_LEVEL_CONNECT, "Polling socket %d failed.", sfd);
727 struct timeval timeout;
729 int socket_is_alive = 0;
731 memset(&timeout, '\0', sizeof(timeout));
732 FD_ZERO(&readable_fds);
733 FD_SET(sfd, &readable_fds);
735 ret = select((int)sfd+1, &readable_fds, NULL, NULL, &timeout);
738 log_error(LOG_LEVEL_ERROR, "select() failed!: %E");
742 * XXX: I'm not sure why !FD_ISSET() works,
743 * but apparently it does.
745 socket_is_alive = !FD_ISSET(sfd, &readable_fds);
747 return socket_is_alive;
748 #endif /* def HAVE_POLL */
752 /*********************************************************************
754 * Function : get_reusable_connection
756 * Description : Returns an open socket to a previously remembered
757 * open connection (if there is one).
760 * 1 : http = The destination for the connection.
761 * 2 : fwd = The forwarder settings.
763 * Returns : JB_INVALID_SOCKET => No reusable connection found,
764 * otherwise a usable socket.
766 *********************************************************************/
767 static jb_socket get_reusable_connection(const struct http_request *http,
768 const struct forward_spec *fwd)
770 jb_socket sfd = JB_INVALID_SOCKET;
771 unsigned int slot = 0;
773 privoxy_mutex_lock(&connection_reuse_mutex);
775 close_unusable_connections();
777 for (slot = 0; slot < SZ(reusable_connection); slot++)
779 if (!reusable_connection[slot].in_use
780 && (JB_INVALID_SOCKET != reusable_connection[slot].sfd))
782 if (connection_destination_matches(&reusable_connection[slot], http, fwd))
784 reusable_connection[slot].in_use = TRUE;
785 sfd = reusable_connection[slot].sfd;
786 log_error(LOG_LEVEL_CONNECT,
787 "Found reusable socket %d for %s:%d in slot %d.",
788 sfd, reusable_connection[slot].host, reusable_connection[slot].port, slot);
794 privoxy_mutex_unlock(&connection_reuse_mutex);
801 /*********************************************************************
803 * Function : mark_connection_unused
805 * Description : Gives a remembered connection free for reuse.
808 * 1 : sfd = The socket belonging to the connection in question.
810 * Returns : TRUE => Socket found and marked as unused.
811 * FALSE => Socket not found.
813 *********************************************************************/
814 static int mark_connection_unused(jb_socket sfd)
816 unsigned int slot = 0;
817 int socket_found = FALSE;
819 assert(sfd != JB_INVALID_SOCKET);
821 privoxy_mutex_lock(&connection_reuse_mutex);
823 for (slot = 0; slot < SZ(reusable_connection); slot++)
825 if (reusable_connection[slot].sfd == sfd)
827 assert(reusable_connection[slot].in_use);
829 log_error(LOG_LEVEL_CONNECT,
830 "Marking open socket %d for %s:%d in slot %d as unused.",
831 sfd, reusable_connection[slot].host,
832 reusable_connection[slot].port, slot);
833 reusable_connection[slot].in_use = 0;
834 reusable_connection[slot].timestamp = time(NULL);
839 privoxy_mutex_unlock(&connection_reuse_mutex);
846 /*********************************************************************
848 * Function : set_keep_alive_timeout
850 * Description : Sets the timeout after which open
851 * connections will no longer be reused.
854 * 1 : timeout = The timeout in seconds.
858 *********************************************************************/
859 void set_keep_alive_timeout(int timeout)
861 keep_alive_timeout = timeout;
863 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
866 /*********************************************************************
868 * Function : forwarded_connect
870 * Description : Connect to a specified web server, possibly via
871 * a HTTP proxy and/or a SOCKS proxy.
874 * 1 : fwd = the proxies to use when connecting.
875 * 2 : http = the http request and apropos headers
876 * 3 : csp = Current client state (buffers, headers, etc...)
878 * Returns : JB_INVALID_SOCKET => failure, else it is the socket file descriptor.
880 *********************************************************************/
881 jb_socket forwarded_connect(const struct forward_spec * fwd,
882 struct http_request *http,
883 struct client_state *csp)
885 const char * dest_host;
887 jb_socket sfd = JB_INVALID_SOCKET;
889 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
890 sfd = get_reusable_connection(http, fwd);
891 if (JB_INVALID_SOCKET != sfd)
895 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
897 /* Figure out if we need to connect to the web server or a HTTP proxy. */
898 if (fwd->forward_host)
901 dest_host = fwd->forward_host;
902 dest_port = fwd->forward_port;
907 dest_host = http->host;
908 dest_port = http->port;
911 /* Connect, maybe using a SOCKS proxy */
915 sfd = connect_to(dest_host, dest_port, csp);
919 sfd = socks4_connect(fwd, dest_host, dest_port, csp);
922 sfd = socks5_connect(fwd, dest_host, dest_port, csp);
925 /* Should never get here */
926 log_error(LOG_LEVEL_FATAL,
927 "SOCKS4 impossible internal error - bad SOCKS type.");
930 if (JB_INVALID_SOCKET != sfd)
932 log_error(LOG_LEVEL_CONNECT,
933 "Created new connection to %s:%d on socket %d.",
934 http->host, http->port, sfd);
942 /*********************************************************************
944 * Function : socks4_connect
946 * Description : Connect to the SOCKS server, and connect through
947 * it to the specified server. This handles
948 * all the SOCKS negotiation, and returns a file
949 * descriptor for a socket which can be treated as a
950 * normal (non-SOCKS) socket.
952 * Logged error messages are saved to csp->error_message
953 * and later reused by error_response() for the CGI
954 * message. strdup allocation failures are handled there.
957 * 1 : fwd = Specifies the SOCKS proxy to use.
958 * 2 : target_host = The final server to connect to.
959 * 3 : target_port = The final port to connect to.
960 * 4 : csp = Current client state (buffers, headers, etc...)
962 * Returns : JB_INVALID_SOCKET => failure, else a socket file descriptor.
964 *********************************************************************/
965 static jb_socket socks4_connect(const struct forward_spec * fwd,
966 const char * target_host,
968 struct client_state *csp)
970 unsigned int web_server_addr;
971 char buf[BUFFER_SIZE];
972 struct socks_op *c = (struct socks_op *)buf;
973 struct socks_reply *s = (struct socks_reply *)buf;
980 if ((fwd->gateway_host == NULL) || (*fwd->gateway_host == '\0'))
982 /* XXX: Shouldn't the config file parser prevent this? */
983 errstr = "NULL gateway host specified.";
987 if (fwd->gateway_port <= 0)
989 errstr = "invalid gateway port specified.";
995 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
996 csp->error_message = strdup(errstr);
998 return(JB_INVALID_SOCKET);
1001 /* build a socks request for connection to the web server */
1003 strlcpy(&(c->userid), socks_userid, sizeof(buf) - sizeof(struct socks_op));
1005 csiz = sizeof(*c) + sizeof(socks_userid) - sizeof(c->userid) - sizeof(c->padding);
1010 web_server_addr = resolve_hostname_to_ip(target_host);
1011 if (web_server_addr == INADDR_NONE)
1013 errstr = "could not resolve target host";
1014 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s %s", errstr, target_host);
1019 web_server_addr = htonl(web_server_addr);
1023 web_server_addr = 0x00000001;
1024 n = csiz + strlen(target_host) + 1;
1025 if (n > sizeof(buf))
1028 errstr = "buffer cbuf too small.";
1029 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
1034 strlcpy(buf + csiz, target_host, sizeof(buf) - sizeof(struct socks_op) - csiz);
1036 * What we forward to the socks4a server should have the
1037 * size of socks_op, plus the length of the userid plus
1038 * its \0 byte (which we don't have to add because the
1039 * first byte of the userid is counted twice as it's also
1040 * part of sock_op) minus the padding bytes (which are part
1041 * of the userid as well), plus the length of the target_host
1042 * (which is stored csiz bytes after the beginning of the buffer),
1043 * plus another \0 byte.
1045 assert(n == sizeof(struct socks_op) + strlen(&(c->userid)) - sizeof(c->padding) + strlen(buf + csiz) + 1);
1050 /* Should never get here */
1051 log_error(LOG_LEVEL_FATAL,
1052 "socks4_connect: SOCKS4 impossible internal error - bad SOCKS type.");
1054 return(JB_INVALID_SOCKET);
1059 csp->error_message = strdup(errstr);
1060 return(JB_INVALID_SOCKET);
1065 c->dstport[0] = (unsigned char)((target_port >> 8 ) & 0xff);
1066 c->dstport[1] = (unsigned char)((target_port ) & 0xff);
1067 c->dstip[0] = (unsigned char)((web_server_addr >> 24 ) & 0xff);
1068 c->dstip[1] = (unsigned char)((web_server_addr >> 16 ) & 0xff);
1069 c->dstip[2] = (unsigned char)((web_server_addr >> 8 ) & 0xff);
1070 c->dstip[3] = (unsigned char)((web_server_addr ) & 0xff);
1072 /* pass the request to the socks server */
1073 sfd = connect_to(fwd->gateway_host, fwd->gateway_port, csp);
1075 if (sfd == JB_INVALID_SOCKET)
1078 * XXX: connect_to should fill in the exact reason.
1079 * Most likely resolving the IP of the forwarder failed.
1081 errstr = "connect_to failed: see logfile for details";
1084 else if (write_socket(sfd, (char *)c, csiz))
1086 errstr = "SOCKS4 negotiation write failed.";
1087 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
1091 else if (read_socket(sfd, buf, sizeof(buf)) != sizeof(*s))
1093 errstr = "SOCKS4 negotiation read failed.";
1094 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
1101 csp->error_message = strdup(errstr);
1102 return(JB_INVALID_SOCKET);
1107 case SOCKS_REQUEST_GRANTED:
1110 case SOCKS_REQUEST_REJECT:
1111 errstr = "SOCKS request rejected or failed.";
1114 case SOCKS_REQUEST_IDENT_FAILED:
1115 errstr = "SOCKS request rejected because "
1116 "SOCKS server cannot connect to identd on the client.";
1119 case SOCKS_REQUEST_IDENT_CONFLICT:
1120 errstr = "SOCKS request rejected because "
1121 "the client program and identd report "
1122 "different user-ids.";
1127 snprintf(buf, sizeof(buf),
1128 "SOCKS request rejected for reason code %d.", s->cd);
1132 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
1133 csp->error_message = strdup(errstr);
1136 return(JB_INVALID_SOCKET);
1140 /*********************************************************************
1142 * Function : translate_socks5_error
1144 * Description : Translates a SOCKS errors to a string.
1147 * 1 : socks_error = The error code to translate.
1149 * Returns : The string translation.
1151 *********************************************************************/
1152 static const char *translate_socks5_error(int socks_error)
1154 switch (socks_error)
1156 /* XXX: these should be more descriptive */
1157 case SOCKS5_REQUEST_FAILED:
1158 return "SOCKS5 request failed";
1159 case SOCKS5_REQUEST_DENIED:
1160 return "SOCKS5 request denied";
1161 case SOCKS5_REQUEST_NETWORK_UNREACHABLE:
1162 return "SOCKS5 network unreachable";
1163 case SOCKS5_REQUEST_HOST_UNREACHABLE:
1164 return "SOCKS5 host unreachable";
1165 case SOCKS5_REQUEST_CONNECTION_REFUSED:
1166 return "SOCKS5 connection refused";
1167 case SOCKS5_REQUEST_TTL_EXPIRED:
1168 return "SOCKS5 TTL expired";
1169 case SOCKS5_REQUEST_PROTOCOL_ERROR:
1170 return "SOCKS5 client protocol error";
1171 case SOCKS5_REQUEST_BAD_ADDRESS_TYPE:
1172 return "SOCKS5 domain names unsupported";
1173 case SOCKS5_REQUEST_GRANTED:
1174 return "everything's peachy";
1176 return "SOCKS5 negotiation protocol error";
1180 /*********************************************************************
1182 * Function : socks5_connect
1184 * Description : Connect to the SOCKS server, and connect through
1185 * it to the specified server. This handles
1186 * all the SOCKS negotiation, and returns a file
1187 * descriptor for a socket which can be treated as a
1188 * normal (non-SOCKS) socket.
1191 * 1 : fwd = Specifies the SOCKS proxy to use.
1192 * 2 : target_host = The final server to connect to.
1193 * 3 : target_port = The final port to connect to.
1194 * 4 : csp = Current client state (buffers, headers, etc...)
1196 * Returns : JB_INVALID_SOCKET => failure, else a socket file descriptor.
1198 *********************************************************************/
1199 static jb_socket socks5_connect(const struct forward_spec *fwd,
1200 const char *target_host,
1202 struct client_state *csp)
1207 size_t client_pos = 0;
1208 int server_size = 0;
1211 const char *errstr = NULL;
1213 assert(fwd->gateway_host);
1214 if ((fwd->gateway_host == NULL) || (*fwd->gateway_host == '\0'))
1216 errstr = "NULL gateway host specified";
1220 if (fwd->gateway_port <= 0)
1223 * XXX: currently this can't happen because in
1224 * case of invalid gateway ports we use the defaults.
1225 * Of course we really shouldn't do that.
1227 errstr = "invalid gateway port specified";
1231 hostlen = strlen(target_host);
1234 errstr = "target host name is longer than 255 characters";
1238 if (fwd->type != SOCKS_5)
1240 /* Should never get here */
1241 log_error(LOG_LEVEL_FATAL,
1242 "SOCKS5 impossible internal error - bad SOCKS type");
1249 assert(errstr != NULL);
1250 log_error(LOG_LEVEL_CONNECT, "socks5_connect: %s", errstr);
1251 csp->error_message = strdup(errstr);
1252 return(JB_INVALID_SOCKET);
1255 /* pass the request to the socks server */
1256 sfd = connect_to(fwd->gateway_host, fwd->gateway_port, csp);
1258 if (sfd == JB_INVALID_SOCKET)
1260 errstr = "socks5 server unreachable";
1261 log_error(LOG_LEVEL_CONNECT, "socks5_connect: %s", errstr);
1262 csp->error_message = strdup(errstr);
1263 return(JB_INVALID_SOCKET);
1267 cbuf[client_pos++] = '\x05'; /* Version */
1268 cbuf[client_pos++] = '\x01'; /* One authentication method supported */
1269 cbuf[client_pos++] = '\x00'; /* The no authentication authentication method */
1271 if (write_socket(sfd, cbuf, client_pos))
1273 errstr = "SOCKS5 negotiation write failed";
1274 csp->error_message = strdup(errstr);
1275 log_error(LOG_LEVEL_CONNECT, "%s", errstr);
1277 return(JB_INVALID_SOCKET);
1280 if (read_socket(sfd, sbuf, sizeof(sbuf)) != 2)
1282 errstr = "SOCKS5 negotiation read failed";
1286 if (!err && (sbuf[0] != '\x05'))
1288 errstr = "SOCKS5 negotiation protocol version error";
1292 if (!err && (sbuf[1] == '\xff'))
1294 errstr = "SOCKS5 authentication required";
1298 if (!err && (sbuf[1] != '\x00'))
1300 errstr = "SOCKS5 negotiation protocol error";
1306 assert(errstr != NULL);
1307 log_error(LOG_LEVEL_CONNECT, "socks5_connect: %s", errstr);
1308 csp->error_message = strdup(errstr);
1311 return(JB_INVALID_SOCKET);
1315 cbuf[client_pos++] = '\x05'; /* Version */
1316 cbuf[client_pos++] = '\x01'; /* TCP connect */
1317 cbuf[client_pos++] = '\x00'; /* Reserved, must be 0x00 */
1318 cbuf[client_pos++] = '\x03'; /* Address is domain name */
1319 cbuf[client_pos++] = (char)(hostlen & 0xffu);
1320 assert(sizeof(cbuf) - client_pos > 255);
1321 /* Using strncpy because we really want the nul byte padding. */
1322 strncpy(cbuf + client_pos, target_host, sizeof(cbuf) - client_pos);
1323 client_pos += (hostlen & 0xffu);
1324 cbuf[client_pos++] = (char)((target_port >> 8) & 0xff);
1325 cbuf[client_pos++] = (char)((target_port ) & 0xff);
1327 if (write_socket(sfd, cbuf, client_pos))
1329 errstr = "SOCKS5 negotiation read failed";
1330 csp->error_message = strdup(errstr);
1331 log_error(LOG_LEVEL_CONNECT, "%s", errstr);
1334 return(JB_INVALID_SOCKET);
1337 server_size = read_socket(sfd, sbuf, sizeof(sbuf));
1338 if (server_size < 3)
1340 errstr = "SOCKS5 negotiation read failed";
1343 else if (server_size > 20)
1345 /* This is somewhat unexpected but doesn't realy matter. */
1346 log_error(LOG_LEVEL_CONNECT, "socks5_connect: read %d bytes "
1347 "from socks server. Would have accepted up to %d.",
1348 server_size, sizeof(sbuf));
1351 if (!err && (sbuf[0] != '\x05'))
1353 errstr = "SOCKS5 negotiation protocol version error";
1357 if (!err && (sbuf[2] != '\x00'))
1359 errstr = "SOCKS5 negotiation protocol error";
1365 if (sbuf[1] == SOCKS5_REQUEST_GRANTED)
1369 errstr = translate_socks5_error(sbuf[1]);
1373 assert(errstr != NULL);
1374 csp->error_message = strdup(errstr);
1375 log_error(LOG_LEVEL_CONNECT, "socks5_connect: %s", errstr);
1379 return(JB_INVALID_SOCKET);