1 const char gateway_rcs[] = "$Id: gateway.c,v 1.48 2009/02/13 17:20:36 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) 2001-2009 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 1.48 2009/02/13 17:20:36 fabiankeil
38 * Reword keep-alive support warning and only show
39 * it #if !defined(HAVE_POLL) && !defined(_WIN32).
41 * Revision 1.47 2008/12/24 17:06:19 fabiankeil
42 * Keep a thread around to timeout alive connections
43 * even if no new requests are coming in.
45 * Revision 1.46 2008/12/13 11:07:23 fabiankeil
46 * Remove duplicated debugging checks
47 * in connection_destination_matches().
49 * Revision 1.45 2008/12/04 18:17:07 fabiankeil
50 * Fix some cparser warnings.
52 * Revision 1.44 2008/11/22 11:54:04 fabiankeil
53 * Move log message around to include the socket number.
55 * Revision 1.43 2008/11/13 09:15:51 fabiankeil
56 * Make keep_alive_timeout static.
58 * Revision 1.42 2008/11/13 09:08:42 fabiankeil
59 * Add new config option: keep-alive-timeout.
61 * Revision 1.41 2008/11/08 15:29:58 fabiankeil
62 * Unify two debug messages.
64 * Revision 1.40 2008/11/08 15:14:05 fabiankeil
65 * Fix duplicated debugging check.
67 * Revision 1.39 2008/10/25 11:33:01 fabiankeil
68 * Remove already out-commented line left over from debugging.
70 * Revision 1.38 2008/10/24 17:33:00 fabiankeil
71 * - Tone the "keep-alive support is experimental" warning
72 * down a bit as hackish 0-chunk detection has been
73 * implemented recently.
74 * - Only show the "ndef HAVE_POLL" warning once on start-up.
76 * Revision 1.37 2008/10/23 17:40:53 fabiankeil
77 * Fix forget_connection() and mark_connection_unused(),
78 * which would both under certain circumstances access
79 * reusable_connection[MAX_REUSABLE_CONNECTIONS]. Oops.
81 * Revision 1.36 2008/10/18 19:49:15 fabiankeil
82 * - Factor close_unusable_connections() out of
83 * get_reusable_connection() to make sure we really check
84 * all the remembered connections, not just the ones before
85 * the next reusable one.
86 * - Plug two file descriptor leaks. Internally marking
87 * connections as closed doesn't cut it.
89 * Revision 1.35 2008/10/17 17:12:01 fabiankeil
90 * In socket_is_still_usable(), use select()
91 * and FD_ISSET() if poll() isn't available.
93 * Revision 1.34 2008/10/17 17:07:13 fabiankeil
94 * Add preliminary timeout support.
96 * Revision 1.33 2008/10/16 16:34:21 fabiankeil
97 * Fix two gcc44 warnings.
99 * Revision 1.32 2008/10/16 16:27:22 fabiankeil
100 * Fix compiler warning.
102 * Revision 1.31 2008/10/16 07:31:11 fabiankeil
103 * - Factor socket_is_still_usable() out of get_reusable_connection().
104 * - If poll() isn't available, show a warning and assume the socket
107 * Revision 1.30 2008/10/13 17:31:03 fabiankeil
108 * If a remembered connection is no longer usable and
109 * has been marked closed, don't bother checking if the
110 * destination matches.
112 * Revision 1.29 2008/10/11 16:59:41 fabiankeil
113 * Add missing dots for two log messages.
115 * Revision 1.28 2008/10/09 18:21:41 fabiankeil
116 * Flush work-in-progress changes to keep outgoing connections
117 * alive where possible. Incomplete and mostly #ifdef'd out.
119 * Revision 1.27 2008/09/27 15:05:51 fabiankeil
120 * Return only once in forwarded_connect().
122 * Revision 1.26 2008/08/18 17:42:06 fabiankeil
123 * Fix typo in macro name.
125 * Revision 1.25 2008/02/07 18:09:46 fabiankeil
127 * - make the buffers quite a bit smaller.
128 * - properly report "socks5 server unreachable" failures.
129 * - let strncpy() use the whole buffer. Using a length of 0xffu wasn't actually
130 * wrong, but requires too much thinking as it doesn't depend on the buffer size.
131 * - log a message if the socks5 server sends more data than expected.
132 * - add some assertions and comments.
134 * Revision 1.24 2008/02/04 14:56:29 fabiankeil
135 * - Fix a compiler warning.
136 * - Stop assuming that htonl(INADDR_NONE) equals INADDR_NONE.
138 * Revision 1.23 2008/02/04 13:11:35 fabiankeil
139 * Remember the cause of the SOCKS5 error for the CGI message.
141 * Revision 1.22 2008/02/03 13:46:15 fabiankeil
142 * Add SOCKS5 support. Patch #1862863 by Eric M. Hopper with minor changes.
144 * Revision 1.21 2007/07/28 12:30:03 fabiankeil
145 * Modified patch from Song Weijia (#1762559) to
146 * fix socks requests on big-endian platforms.
148 * Revision 1.20 2007/05/14 10:23:48 fabiankeil
149 * - Use strlcpy() instead of strcpy().
150 * - Use the same buffer for socks requests and socks responses.
151 * - Fix bogus warning about web_server_addr being used uninitialized.
153 * Revision 1.19 2007/01/25 14:09:45 fabiankeil
154 * - Save errors in socks4_connect() to csp->error_message.
155 * - Silence some gcc43 warnings, hopefully the right way.
157 * Revision 1.18 2006/07/18 14:48:46 david__schmidt
158 * Reorganizing the repository: swapping out what was HEAD (the old 3.1 branch)
159 * with what was really the latest development (the v_3_0_branch branch)
161 * Revision 1.16 2002/05/12 21:36:29 jongfoster
162 * Correcting function comments
164 * Revision 1.15 2002/03/26 22:29:54 swa
165 * we have a new homepage!
167 * Revision 1.14 2002/03/24 13:25:43 swa
168 * name change related issues
170 * Revision 1.13 2002/03/13 00:29:59 jongfoster
173 * Revision 1.12 2002/03/09 20:03:52 jongfoster
174 * - Making various functions return int rather than size_t.
175 * (Undoing a recent change). Since size_t is unsigned on
176 * Windows, functions like read_socket that return -1 on
177 * error cannot return a size_t.
179 * THIS WAS A MAJOR BUG - it caused frequent, unpredictable
180 * crashes, and also frequently caused JB to jump to 100%
181 * CPU and stay there. (Because it thought it had just
182 * read ((unsigned)-1) == 4Gb of data...)
184 * - The signature of write_socket has changed, it now simply
185 * returns success=0/failure=nonzero.
187 * - Trying to get rid of a few warnings --with-debug on
188 * Windows, I've introduced a new type "jb_socket". This is
189 * used for the socket file descriptors. On Windows, this
190 * is SOCKET (a typedef for unsigned). Everywhere else, it's
191 * an int. The error value can't be -1 any more, so it's
192 * now JB_INVALID_SOCKET (which is -1 on UNIX, and in
193 * Windows it maps to the #define INVALID_SOCKET.)
195 * - The signature of bind_port has changed.
197 * Revision 1.11 2002/03/08 17:46:04 jongfoster
198 * Fixing int/size_t warnings
200 * Revision 1.10 2002/03/07 03:50:19 oes
201 * - Improved handling of failed DNS lookups
202 * - Fixed compiler warnings
204 * Revision 1.9 2001/10/25 03:40:48 david__schmidt
205 * Change in porting tactics: OS/2's EMX porting layer doesn't allow multiple
206 * threads to call select() simultaneously. So, it's time to do a real, live,
207 * native OS/2 port. See defines for __EMX__ (the porting layer) vs. __OS2__
208 * (native). Both versions will work, but using __OS2__ offers multi-threading.
210 * Revision 1.8 2001/09/13 20:10:12 jongfoster
211 * Fixing missing #include under Windows
213 * Revision 1.7 2001/09/12 17:58:26 steudten
215 * add #include <string.h>
217 * Revision 1.6 2001/09/10 10:41:16 oes
218 * Added #include in.h
220 * Revision 1.5 2001/07/29 18:47:57 jongfoster
221 * Adding missing #include project.h
223 * Revision 1.4 2001/07/24 12:47:06 oes
224 * Applied BeOS support update by Eugenia
226 * Revision 1.3 2001/06/09 10:55:28 jongfoster
227 * Changing BUFSIZ ==> BUFFER_SIZE
229 * Revision 1.2 2001/06/07 23:11:38 jongfoster
230 * Removing gateways[] list - no longer used.
231 * Replacing function pointer in struct gateway with a directly
232 * called function forwarded_connect(), which can do the common
233 * task of deciding whether to connect to the web server or HTTP
235 * Replacing struct gateway with struct forward_spec
236 * Fixing bug with SOCKS4A and HTTP proxy server in combination.
237 * It was a bug which led to the connection being made to the web
238 * server rather than the HTTP proxy, and also a buffer overrun.
240 * Revision 1.1.1.1 2001/05/15 13:58:54 oes
241 * Initial import of version 2.9.3 source tree
244 *********************************************************************/
250 #include <sys/types.h>
253 #include <netinet/in.h>
261 #include <winsock2.h>
262 #endif /* def _WIN32 */
266 #endif /* def __BEOS__ */
270 #endif /* def __OS2__ */
275 #include "jbsockets.h"
277 #include "miscutil.h"
278 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
281 #include <sys/poll.h>
284 #endif /* def __GLIBC__ */
285 #endif /* HAVE_POLL */
286 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
288 const char gateway_h_rcs[] = GATEWAY_H_VERSION;
290 static jb_socket socks4_connect(const struct forward_spec * fwd,
291 const char * target_host,
293 struct client_state *csp);
295 static jb_socket socks5_connect(const struct forward_spec *fwd,
296 const char *target_host,
298 struct client_state *csp);
301 #define SOCKS_REQUEST_GRANTED 90
302 #define SOCKS_REQUEST_REJECT 91
303 #define SOCKS_REQUEST_IDENT_FAILED 92
304 #define SOCKS_REQUEST_IDENT_CONFLICT 93
306 #define SOCKS5_REQUEST_GRANTED 0
307 #define SOCKS5_REQUEST_FAILED 1
308 #define SOCKS5_REQUEST_DENIED 2
309 #define SOCKS5_REQUEST_NETWORK_UNREACHABLE 3
310 #define SOCKS5_REQUEST_HOST_UNREACHABLE 4
311 #define SOCKS5_REQUEST_CONNECTION_REFUSED 5
312 #define SOCKS5_REQUEST_TTL_EXPIRED 6
313 #define SOCKS5_REQUEST_PROTOCOL_ERROR 7
314 #define SOCKS5_REQUEST_BAD_ADDRESS_TYPE 8
316 /* structure of a socks client operation */
318 unsigned char vn; /* socks version number */
319 unsigned char cd; /* command code */
320 unsigned char dstport[2]; /* destination port */
321 unsigned char dstip[4]; /* destination address */
322 char userid; /* first byte of userid */
323 char padding[3]; /* make sure sizeof(struct socks_op) is endian-independent. */
324 /* more bytes of the userid follow, terminated by a NULL */
327 /* structure of a socks server reply */
329 unsigned char vn; /* socks version number */
330 unsigned char cd; /* command code */
331 unsigned char dstport[2]; /* destination port */
332 unsigned char dstip[4]; /* destination address */
335 static const char socks_userid[] = "anonymous";
337 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
339 #define MAX_REUSABLE_CONNECTIONS 100
340 static int keep_alive_timeout = DEFAULT_KEEP_ALIVE_TIMEOUT;
342 static struct reusable_connection reusable_connection[MAX_REUSABLE_CONNECTIONS];
343 static int mark_connection_unused(jb_socket sfd);
345 /*********************************************************************
347 * Function : initialize_reusable_connections
349 * Description : Initializes the reusable_connection structures.
350 * Must be called with connection_reuse_mutex locked.
356 *********************************************************************/
357 extern void initialize_reusable_connections(void)
359 unsigned int slot = 0;
361 #if !defined(HAVE_POLL) && !defined(_WIN32)
362 log_error(LOG_LEVEL_INFO,
363 "Detecting already dead connections might not work "
364 "correctly on your platform. In case of problems, "
365 "unset the keep-alive-timeout option.");
368 for (slot = 0; slot < SZ(reusable_connection); slot++)
370 mark_connection_closed(&reusable_connection[slot]);
373 log_error(LOG_LEVEL_CONNECT, "Initialized %d socket slots.", slot);
377 /*********************************************************************
379 * Function : remember_connection
381 * Description : Remembers a connection for reuse later on.
384 * 1 : sfd = Open socket to remember.
385 * 2 : http = The destination for the connection.
386 * 3 : fwd = The forwarder settings used.
390 *********************************************************************/
391 void remember_connection(jb_socket sfd, const struct http_request *http,
392 const struct forward_spec *fwd)
394 unsigned int slot = 0;
395 int free_slot_found = FALSE;
397 assert(sfd != JB_INVALID_SOCKET);
399 if (mark_connection_unused(sfd))
404 privoxy_mutex_lock(&connection_reuse_mutex);
406 /* Find free socket slot. */
407 for (slot = 0; slot < SZ(reusable_connection); slot++)
409 if (reusable_connection[slot].sfd == JB_INVALID_SOCKET)
411 assert(reusable_connection[slot].in_use == 0);
412 log_error(LOG_LEVEL_CONNECT,
413 "Remembering socket %d for %s:%d in slot %d.",
414 sfd, http->host, http->port, slot);
415 free_slot_found = TRUE;
420 if (!free_slot_found)
422 log_error(LOG_LEVEL_CONNECT,
423 "No free slots found to remembering socket for %s:%d. Last slot %d.",
424 http->host, http->port, slot);
425 privoxy_mutex_unlock(&connection_reuse_mutex);
430 assert(NULL != http->host);
431 reusable_connection[slot].host = strdup(http->host);
432 if (NULL == reusable_connection[slot].host)
434 log_error(LOG_LEVEL_FATAL, "Out of memory saving socket.");
436 reusable_connection[slot].sfd = sfd;
437 reusable_connection[slot].port = http->port;
438 reusable_connection[slot].in_use = 0;
439 reusable_connection[slot].timestamp = time(NULL);
442 assert(reusable_connection[slot].gateway_host == NULL);
443 assert(reusable_connection[slot].gateway_port == 0);
444 assert(reusable_connection[slot].forwarder_type == SOCKS_NONE);
445 assert(reusable_connection[slot].forward_host == NULL);
446 assert(reusable_connection[slot].forward_port == 0);
448 reusable_connection[slot].forwarder_type = fwd->type;
449 if (NULL != fwd->gateway_host)
451 reusable_connection[slot].gateway_host = strdup(fwd->gateway_host);
452 if (NULL == reusable_connection[slot].gateway_host)
454 log_error(LOG_LEVEL_FATAL, "Out of memory saving gateway_host.");
459 reusable_connection[slot].gateway_host = NULL;
461 reusable_connection[slot].gateway_port = fwd->gateway_port;
463 if (NULL != fwd->forward_host)
465 reusable_connection[slot].forward_host = strdup(fwd->forward_host);
466 if (NULL == reusable_connection[slot].forward_host)
468 log_error(LOG_LEVEL_FATAL, "Out of memory saving forward_host.");
473 reusable_connection[slot].forward_host = NULL;
475 reusable_connection[slot].forward_port = fwd->forward_port;
477 privoxy_mutex_unlock(&connection_reuse_mutex);
481 /*********************************************************************
483 * Function : mark_connection_closed
485 * Description : Marks a reused connection closed.
488 * 1 : closed_connection = The connection to mark as closed.
492 *********************************************************************/
493 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 int connection_destination_matches(const struct reusable_connection *connection,
570 const struct http_request *http,
571 const struct forward_spec *fwd)
573 if ((connection->forwarder_type != fwd->type)
574 || (connection->gateway_port != fwd->gateway_port)
575 || (connection->forward_port != fwd->forward_port)
576 || (connection->port != http->port))
581 if (( (NULL != connection->gateway_host)
582 && (NULL != fwd->gateway_host)
583 && strcmpic(connection->gateway_host, fwd->gateway_host))
584 && (connection->gateway_host != fwd->gateway_host))
586 log_error(LOG_LEVEL_CONNECT, "Gateway mismatch.");
590 if (( (NULL != connection->forward_host)
591 && (NULL != fwd->forward_host)
592 && strcmpic(connection->forward_host, fwd->forward_host))
593 && (connection->forward_host != fwd->forward_host))
595 log_error(LOG_LEVEL_CONNECT, "Forwarding proxy mismatch.");
599 return (!strcmpic(connection->host, http->host));
604 /*********************************************************************
606 * Function : close_unusable_connections
608 * Description : Closes remembered connections that have timed
609 * out or have been closed on the other side.
613 * Returns : Number of connections that are still alive.
615 *********************************************************************/
616 int close_unusable_connections(void)
618 unsigned int slot = 0;
619 int connections_alive = 0;
621 privoxy_mutex_lock(&connection_reuse_mutex);
623 for (slot = 0; slot < SZ(reusable_connection); slot++)
625 if (!reusable_connection[slot].in_use
626 && (JB_INVALID_SOCKET != reusable_connection[slot].sfd))
628 time_t time_open = time(NULL) - reusable_connection[slot].timestamp;
630 if (keep_alive_timeout < time_open)
632 log_error(LOG_LEVEL_CONNECT,
633 "The connection to %s:%d in slot %d timed out. "
634 "Closing socket %d. Timeout is: %d.",
635 reusable_connection[slot].host,
636 reusable_connection[slot].port, slot,
637 reusable_connection[slot].sfd, keep_alive_timeout);
638 close_socket(reusable_connection[slot].sfd);
639 mark_connection_closed(&reusable_connection[slot]);
641 else if (!socket_is_still_usable(reusable_connection[slot].sfd))
643 log_error(LOG_LEVEL_CONNECT,
644 "The connection to %s:%d in slot %d is no longer usable. "
645 "Closing socket %d.", reusable_connection[slot].host,
646 reusable_connection[slot].port, slot,
647 reusable_connection[slot].sfd);
648 close_socket(reusable_connection[slot].sfd);
649 mark_connection_closed(&reusable_connection[slot]);
658 privoxy_mutex_unlock(&connection_reuse_mutex);
660 return connections_alive;
665 /*********************************************************************
667 * Function : get_reusable_connection
669 * Description : Returns an open socket to a previously remembered
670 * open connection (if there is one).
673 * 1 : http = The destination for the connection.
674 * 2 : fwd = The forwarder settings.
676 * Returns : JB_INVALID_SOCKET => No reusable connection found,
677 * otherwise a usable socket.
679 *********************************************************************/
680 static jb_socket get_reusable_connection(const struct http_request *http,
681 const struct forward_spec *fwd)
683 jb_socket sfd = JB_INVALID_SOCKET;
684 unsigned int slot = 0;
686 close_unusable_connections();
688 privoxy_mutex_lock(&connection_reuse_mutex);
690 for (slot = 0; slot < SZ(reusable_connection); slot++)
692 if (!reusable_connection[slot].in_use
693 && (JB_INVALID_SOCKET != reusable_connection[slot].sfd))
695 if (connection_destination_matches(&reusable_connection[slot], http, fwd))
697 reusable_connection[slot].in_use = TRUE;
698 sfd = reusable_connection[slot].sfd;
699 log_error(LOG_LEVEL_CONNECT,
700 "Found reusable socket %d for %s:%d in slot %d.",
701 sfd, reusable_connection[slot].host, reusable_connection[slot].port, slot);
707 privoxy_mutex_unlock(&connection_reuse_mutex);
714 /*********************************************************************
716 * Function : mark_connection_unused
718 * Description : Gives a remembered connection free for reuse.
721 * 1 : sfd = The socket belonging to the connection in question.
723 * Returns : TRUE => Socket found and marked as unused.
724 * FALSE => Socket not found.
726 *********************************************************************/
727 static int mark_connection_unused(jb_socket sfd)
729 unsigned int slot = 0;
730 int socket_found = FALSE;
732 assert(sfd != JB_INVALID_SOCKET);
734 privoxy_mutex_lock(&connection_reuse_mutex);
736 for (slot = 0; slot < SZ(reusable_connection); slot++)
738 if (reusable_connection[slot].sfd == sfd)
740 assert(reusable_connection[slot].in_use);
742 log_error(LOG_LEVEL_CONNECT,
743 "Marking open socket %d for %s:%d in slot %d as unused.",
744 sfd, reusable_connection[slot].host,
745 reusable_connection[slot].port, slot);
746 reusable_connection[slot].in_use = 0;
747 reusable_connection[slot].timestamp = time(NULL);
752 privoxy_mutex_unlock(&connection_reuse_mutex);
759 /*********************************************************************
761 * Function : set_keep_alive_timeout
763 * Description : Sets the timeout after which open
764 * connections will no longer be reused.
767 * 1 : timeout = The timeout in seconds.
771 *********************************************************************/
772 void set_keep_alive_timeout(int timeout)
774 keep_alive_timeout = timeout;
776 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
779 /*********************************************************************
781 * Function : forwarded_connect
783 * Description : Connect to a specified web server, possibly via
784 * a HTTP proxy and/or a SOCKS proxy.
787 * 1 : fwd = the proxies to use when connecting.
788 * 2 : http = the http request and apropos headers
789 * 3 : csp = Current client state (buffers, headers, etc...)
791 * Returns : JB_INVALID_SOCKET => failure, else it is the socket file descriptor.
793 *********************************************************************/
794 jb_socket forwarded_connect(const struct forward_spec * fwd,
795 struct http_request *http,
796 struct client_state *csp)
798 const char * dest_host;
800 jb_socket sfd = JB_INVALID_SOCKET;
802 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
803 sfd = get_reusable_connection(http, fwd);
804 if (JB_INVALID_SOCKET != sfd)
808 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
810 /* Figure out if we need to connect to the web server or a HTTP proxy. */
811 if (fwd->forward_host)
814 dest_host = fwd->forward_host;
815 dest_port = fwd->forward_port;
820 dest_host = http->host;
821 dest_port = http->port;
824 /* Connect, maybe using a SOCKS proxy */
828 sfd = connect_to(dest_host, dest_port, csp);
832 sfd = socks4_connect(fwd, dest_host, dest_port, csp);
835 sfd = socks5_connect(fwd, dest_host, dest_port, csp);
838 /* Should never get here */
839 log_error(LOG_LEVEL_FATAL,
840 "SOCKS4 impossible internal error - bad SOCKS type.");
843 if (JB_INVALID_SOCKET != sfd)
845 log_error(LOG_LEVEL_CONNECT,
846 "Created new connection to %s:%d on socket %d.",
847 http->host, http->port, sfd);
855 /*********************************************************************
857 * Function : socks4_connect
859 * Description : Connect to the SOCKS server, and connect through
860 * it to the specified server. This handles
861 * all the SOCKS negotiation, and returns a file
862 * descriptor for a socket which can be treated as a
863 * normal (non-SOCKS) socket.
865 * Logged error messages are saved to csp->error_message
866 * and later reused by error_response() for the CGI
867 * message. strdup allocation failures are handled there.
870 * 1 : fwd = Specifies the SOCKS proxy to use.
871 * 2 : target_host = The final server to connect to.
872 * 3 : target_port = The final port to connect to.
873 * 4 : csp = Current client state (buffers, headers, etc...)
875 * Returns : JB_INVALID_SOCKET => failure, else a socket file descriptor.
877 *********************************************************************/
878 static jb_socket socks4_connect(const struct forward_spec * fwd,
879 const char * target_host,
881 struct client_state *csp)
883 unsigned int web_server_addr;
884 char buf[BUFFER_SIZE];
885 struct socks_op *c = (struct socks_op *)buf;
886 struct socks_reply *s = (struct socks_reply *)buf;
893 if ((fwd->gateway_host == NULL) || (*fwd->gateway_host == '\0'))
895 /* XXX: Shouldn't the config file parser prevent this? */
896 errstr = "NULL gateway host specified.";
900 if (fwd->gateway_port <= 0)
902 errstr = "invalid gateway port specified.";
908 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
909 csp->error_message = strdup(errstr);
911 return(JB_INVALID_SOCKET);
914 /* build a socks request for connection to the web server */
916 strlcpy(&(c->userid), socks_userid, sizeof(buf) - sizeof(struct socks_op));
918 csiz = sizeof(*c) + sizeof(socks_userid) - sizeof(c->userid) - sizeof(c->padding);
923 web_server_addr = resolve_hostname_to_ip(target_host);
924 if (web_server_addr == INADDR_NONE)
926 errstr = "could not resolve target host";
927 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s %s", errstr, target_host);
932 web_server_addr = htonl(web_server_addr);
936 web_server_addr = 0x00000001;
937 n = csiz + strlen(target_host) + 1;
941 errstr = "buffer cbuf too small.";
942 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
947 strlcpy(buf + csiz, target_host, sizeof(buf) - sizeof(struct socks_op) - csiz);
949 * What we forward to the socks4a server should have the
950 * size of socks_op, plus the length of the userid plus
951 * its \0 byte (which we don't have to add because the
952 * first byte of the userid is counted twice as it's also
953 * part of sock_op) minus the padding bytes (which are part
954 * of the userid as well), plus the length of the target_host
955 * (which is stored csiz bytes after the beginning of the buffer),
956 * plus another \0 byte.
958 assert(n == sizeof(struct socks_op) + strlen(&(c->userid)) - sizeof(c->padding) + strlen(buf + csiz) + 1);
963 /* Should never get here */
964 log_error(LOG_LEVEL_FATAL,
965 "socks4_connect: SOCKS4 impossible internal error - bad SOCKS type.");
967 return(JB_INVALID_SOCKET);
972 csp->error_message = strdup(errstr);
973 return(JB_INVALID_SOCKET);
978 c->dstport[0] = (unsigned char)((target_port >> 8 ) & 0xff);
979 c->dstport[1] = (unsigned char)((target_port ) & 0xff);
980 c->dstip[0] = (unsigned char)((web_server_addr >> 24 ) & 0xff);
981 c->dstip[1] = (unsigned char)((web_server_addr >> 16 ) & 0xff);
982 c->dstip[2] = (unsigned char)((web_server_addr >> 8 ) & 0xff);
983 c->dstip[3] = (unsigned char)((web_server_addr ) & 0xff);
985 /* pass the request to the socks server */
986 sfd = connect_to(fwd->gateway_host, fwd->gateway_port, csp);
988 if (sfd == JB_INVALID_SOCKET)
991 * XXX: connect_to should fill in the exact reason.
992 * Most likely resolving the IP of the forwarder failed.
994 errstr = "connect_to failed: see logfile for details";
997 else if (write_socket(sfd, (char *)c, csiz))
999 errstr = "SOCKS4 negotiation write failed.";
1000 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
1004 else if (read_socket(sfd, buf, sizeof(buf)) != sizeof(*s))
1006 errstr = "SOCKS4 negotiation read failed.";
1007 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
1014 csp->error_message = strdup(errstr);
1015 return(JB_INVALID_SOCKET);
1020 case SOCKS_REQUEST_GRANTED:
1022 case SOCKS_REQUEST_REJECT:
1023 errstr = "SOCKS request rejected or failed.";
1026 case SOCKS_REQUEST_IDENT_FAILED:
1027 errstr = "SOCKS request rejected because "
1028 "SOCKS server cannot connect to identd on the client.";
1031 case SOCKS_REQUEST_IDENT_CONFLICT:
1032 errstr = "SOCKS request rejected because "
1033 "the client program and identd report "
1034 "different user-ids.";
1039 snprintf(buf, sizeof(buf),
1040 "SOCKS request rejected for reason code %d.", s->cd);
1044 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
1045 csp->error_message = strdup(errstr);
1048 return(JB_INVALID_SOCKET);
1052 /*********************************************************************
1054 * Function : translate_socks5_error
1056 * Description : Translates a SOCKS errors to a string.
1059 * 1 : socks_error = The error code to translate.
1061 * Returns : The string translation.
1063 *********************************************************************/
1064 static const char *translate_socks5_error(int socks_error)
1066 switch (socks_error)
1068 /* XXX: these should be more descriptive */
1069 case SOCKS5_REQUEST_FAILED:
1070 return "SOCKS5 request failed";
1071 case SOCKS5_REQUEST_DENIED:
1072 return "SOCKS5 request denied";
1073 case SOCKS5_REQUEST_NETWORK_UNREACHABLE:
1074 return "SOCKS5 network unreachable";
1075 case SOCKS5_REQUEST_HOST_UNREACHABLE:
1076 return "SOCKS5 host unreachable";
1077 case SOCKS5_REQUEST_CONNECTION_REFUSED:
1078 return "SOCKS5 connection refused";
1079 case SOCKS5_REQUEST_TTL_EXPIRED:
1080 return "SOCKS5 TTL expired";
1081 case SOCKS5_REQUEST_PROTOCOL_ERROR:
1082 return "SOCKS5 client protocol error";
1083 case SOCKS5_REQUEST_BAD_ADDRESS_TYPE:
1084 return "SOCKS5 domain names unsupported";
1085 case SOCKS5_REQUEST_GRANTED:
1086 return "everything's peachy";
1088 return "SOCKS5 negotiation protocol error";
1092 /*********************************************************************
1094 * Function : socks5_connect
1096 * Description : Connect to the SOCKS server, and connect through
1097 * it to the specified server. This handles
1098 * all the SOCKS negotiation, and returns a file
1099 * descriptor for a socket which can be treated as a
1100 * normal (non-SOCKS) socket.
1103 * 1 : fwd = Specifies the SOCKS proxy to use.
1104 * 2 : target_host = The final server to connect to.
1105 * 3 : target_port = The final port to connect to.
1106 * 4 : csp = Current client state (buffers, headers, etc...)
1108 * Returns : JB_INVALID_SOCKET => failure, else a socket file descriptor.
1110 *********************************************************************/
1111 static jb_socket socks5_connect(const struct forward_spec *fwd,
1112 const char *target_host,
1114 struct client_state *csp)
1119 size_t client_pos = 0;
1120 int server_size = 0;
1123 const char *errstr = NULL;
1125 assert(fwd->gateway_host);
1126 if ((fwd->gateway_host == NULL) || (*fwd->gateway_host == '\0'))
1128 errstr = "NULL gateway host specified";
1132 if (fwd->gateway_port <= 0)
1135 * XXX: currently this can't happen because in
1136 * case of invalid gateway ports we use the defaults.
1137 * Of course we really shouldn't do that.
1139 errstr = "invalid gateway port specified";
1143 hostlen = strlen(target_host);
1144 if (hostlen > (size_t)255)
1146 errstr = "target host name is longer than 255 characters";
1150 if (fwd->type != SOCKS_5)
1152 /* Should never get here */
1153 log_error(LOG_LEVEL_FATAL,
1154 "SOCKS5 impossible internal error - bad SOCKS type");
1161 assert(errstr != NULL);
1162 log_error(LOG_LEVEL_CONNECT, "socks5_connect: %s", errstr);
1163 csp->error_message = strdup(errstr);
1164 return(JB_INVALID_SOCKET);
1167 /* pass the request to the socks server */
1168 sfd = connect_to(fwd->gateway_host, fwd->gateway_port, csp);
1170 if (sfd == JB_INVALID_SOCKET)
1172 errstr = "socks5 server unreachable";
1173 log_error(LOG_LEVEL_CONNECT, "socks5_connect: %s", errstr);
1174 csp->error_message = strdup(errstr);
1175 return(JB_INVALID_SOCKET);
1179 cbuf[client_pos++] = '\x05'; /* Version */
1180 cbuf[client_pos++] = '\x01'; /* One authentication method supported */
1181 cbuf[client_pos++] = '\x00'; /* The no authentication authentication method */
1183 if (write_socket(sfd, cbuf, client_pos))
1185 errstr = "SOCKS5 negotiation write failed";
1186 csp->error_message = strdup(errstr);
1187 log_error(LOG_LEVEL_CONNECT, "%s", errstr);
1189 return(JB_INVALID_SOCKET);
1192 if (read_socket(sfd, sbuf, sizeof(sbuf)) != 2)
1194 errstr = "SOCKS5 negotiation read failed";
1198 if (!err && (sbuf[0] != '\x05'))
1200 errstr = "SOCKS5 negotiation protocol version error";
1204 if (!err && (sbuf[1] == '\xff'))
1206 errstr = "SOCKS5 authentication required";
1210 if (!err && (sbuf[1] != '\x00'))
1212 errstr = "SOCKS5 negotiation protocol error";
1218 assert(errstr != NULL);
1219 log_error(LOG_LEVEL_CONNECT, "socks5_connect: %s", errstr);
1220 csp->error_message = strdup(errstr);
1223 return(JB_INVALID_SOCKET);
1227 cbuf[client_pos++] = '\x05'; /* Version */
1228 cbuf[client_pos++] = '\x01'; /* TCP connect */
1229 cbuf[client_pos++] = '\x00'; /* Reserved, must be 0x00 */
1230 cbuf[client_pos++] = '\x03'; /* Address is domain name */
1231 cbuf[client_pos++] = (char)(hostlen & 0xffu);
1232 assert(sizeof(cbuf) - client_pos > (size_t)255);
1233 /* Using strncpy because we really want the nul byte padding. */
1234 strncpy(cbuf + client_pos, target_host, sizeof(cbuf) - client_pos);
1235 client_pos += (hostlen & 0xffu);
1236 cbuf[client_pos++] = (char)((target_port >> 8) & 0xff);
1237 cbuf[client_pos++] = (char)((target_port ) & 0xff);
1239 if (write_socket(sfd, cbuf, client_pos))
1241 errstr = "SOCKS5 negotiation read failed";
1242 csp->error_message = strdup(errstr);
1243 log_error(LOG_LEVEL_CONNECT, "%s", errstr);
1246 return(JB_INVALID_SOCKET);
1249 server_size = read_socket(sfd, sbuf, sizeof(sbuf));
1250 if (server_size < 3)
1252 errstr = "SOCKS5 negotiation read failed";
1255 else if (server_size > 20)
1257 /* This is somewhat unexpected but doesn't realy matter. */
1258 log_error(LOG_LEVEL_CONNECT, "socks5_connect: read %d bytes "
1259 "from socks server. Would have accepted up to %d.",
1260 server_size, sizeof(sbuf));
1263 if (!err && (sbuf[0] != '\x05'))
1265 errstr = "SOCKS5 negotiation protocol version error";
1269 if (!err && (sbuf[2] != '\x00'))
1271 errstr = "SOCKS5 negotiation protocol error";
1277 if (sbuf[1] == SOCKS5_REQUEST_GRANTED)
1281 errstr = translate_socks5_error(sbuf[1]);
1285 assert(errstr != NULL);
1286 csp->error_message = strdup(errstr);
1287 log_error(LOG_LEVEL_CONNECT, "socks5_connect: %s", errstr);
1291 return(JB_INVALID_SOCKET);