1 const char gateway_rcs[] = "$Id: gateway.c,v 1.95 2015/08/12 10:37:11 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
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.
35 *********************************************************************/
41 #include <sys/types.h>
44 #include <netinet/in.h>
53 #endif /* def _WIN32 */
57 #endif /* def __BEOS__ */
61 #endif /* def __OS2__ */
66 #include "jbsockets.h"
72 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
78 #endif /* def __GLIBC__ */
79 #endif /* HAVE_POLL */
80 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
82 const char gateway_h_rcs[] = GATEWAY_H_VERSION;
84 static jb_socket socks4_connect(const struct forward_spec * fwd,
85 const char * target_host,
87 struct client_state *csp);
89 static jb_socket socks5_connect(const struct forward_spec *fwd,
90 const char *target_host,
92 struct client_state *csp);
95 SOCKS4_REQUEST_GRANTED = 90,
96 SOCKS4_REQUEST_REJECT = 91,
97 SOCKS4_REQUEST_IDENT_FAILED = 92,
98 SOCKS4_REQUEST_IDENT_CONFLICT = 93
102 SOCKS5_REQUEST_GRANTED = 0,
103 SOCKS5_REQUEST_FAILED = 1,
104 SOCKS5_REQUEST_DENIED = 2,
105 SOCKS5_REQUEST_NETWORK_UNREACHABLE = 3,
106 SOCKS5_REQUEST_HOST_UNREACHABLE = 4,
107 SOCKS5_REQUEST_CONNECTION_REFUSED = 5,
108 SOCKS5_REQUEST_TTL_EXPIRED = 6,
109 SOCKS5_REQUEST_PROTOCOL_ERROR = 7,
110 SOCKS5_REQUEST_BAD_ADDRESS_TYPE = 8
113 /* structure of a socks client operation */
115 unsigned char vn; /* socks version number */
116 unsigned char cd; /* command code */
117 unsigned char dstport[2]; /* destination port */
118 unsigned char dstip[4]; /* destination address */
119 char userid; /* first byte of userid */
120 char padding[3]; /* make sure sizeof(struct socks_op) is endian-independent. */
121 /* more bytes of the userid follow, terminated by a NULL */
124 /* structure of a socks server reply */
126 unsigned char vn; /* socks version number */
127 unsigned char cd; /* command code */
128 unsigned char dstport[2]; /* destination port */
129 unsigned char dstip[4]; /* destination address */
132 static const char socks_userid[] = "anonymous";
134 #ifdef FEATURE_CONNECTION_SHARING
136 #define MAX_REUSABLE_CONNECTIONS 100
137 static unsigned int keep_alive_timeout = DEFAULT_KEEP_ALIVE_TIMEOUT;
139 static struct reusable_connection reusable_connection[MAX_REUSABLE_CONNECTIONS];
140 static int mark_connection_unused(const struct reusable_connection *connection);
142 /*********************************************************************
144 * Function : initialize_reusable_connections
146 * Description : Initializes the reusable_connection structures.
147 * Must be called with connection_reuse_mutex locked.
153 *********************************************************************/
154 extern void initialize_reusable_connections(void)
156 unsigned int slot = 0;
158 #if !defined(HAVE_POLL) && !defined(_WIN32)
159 log_error(LOG_LEVEL_INFO,
160 "Detecting already dead connections might not work "
161 "correctly on your platform. In case of problems, "
162 "unset the keep-alive-timeout option.");
165 for (slot = 0; slot < SZ(reusable_connection); slot++)
167 mark_connection_closed(&reusable_connection[slot]);
170 log_error(LOG_LEVEL_CONNECT, "Initialized %d socket slots.", slot);
174 /*********************************************************************
176 * Function : remember_connection
178 * Description : Remembers a server connection for reuse later on.
181 * 1 : connection = The server connection to remember.
185 *********************************************************************/
186 void remember_connection(const struct reusable_connection *connection)
188 unsigned int slot = 0;
189 int free_slot_found = FALSE;
191 assert(NULL != connection);
192 assert(connection->sfd != JB_INVALID_SOCKET);
194 if (mark_connection_unused(connection))
199 privoxy_mutex_lock(&connection_reuse_mutex);
201 /* Find free socket slot. */
202 for (slot = 0; slot < SZ(reusable_connection); slot++)
204 if (reusable_connection[slot].sfd == JB_INVALID_SOCKET)
206 assert(reusable_connection[slot].in_use == 0);
207 log_error(LOG_LEVEL_CONNECT,
208 "Remembering socket %d for %s:%d in slot %d.",
209 connection->sfd, connection->host, connection->port, slot);
210 free_slot_found = TRUE;
215 if (!free_slot_found)
217 log_error(LOG_LEVEL_CONNECT,
218 "No free slots found to remember socket for %s:%d. Last slot %d.",
219 connection->host, connection->port, slot);
220 privoxy_mutex_unlock(&connection_reuse_mutex);
221 close_socket(connection->sfd);
225 assert(NULL != connection->host);
226 reusable_connection[slot].host = strdup_or_die(connection->host);
227 reusable_connection[slot].sfd = connection->sfd;
228 reusable_connection[slot].port = connection->port;
229 reusable_connection[slot].in_use = 0;
230 reusable_connection[slot].timestamp = connection->timestamp;
231 reusable_connection[slot].request_sent = connection->request_sent;
232 reusable_connection[slot].response_received = connection->response_received;
233 reusable_connection[slot].keep_alive_timeout = connection->keep_alive_timeout;
234 reusable_connection[slot].requests_sent_total = connection->requests_sent_total;
236 assert(reusable_connection[slot].gateway_host == NULL);
237 assert(reusable_connection[slot].gateway_port == 0);
238 assert(reusable_connection[slot].forwarder_type == SOCKS_NONE);
239 assert(reusable_connection[slot].forward_host == NULL);
240 assert(reusable_connection[slot].forward_port == 0);
242 reusable_connection[slot].forwarder_type = connection->forwarder_type;
243 if (NULL != connection->gateway_host)
245 reusable_connection[slot].gateway_host = strdup_or_die(connection->gateway_host);
249 reusable_connection[slot].gateway_host = NULL;
251 reusable_connection[slot].gateway_port = connection->gateway_port;
253 if (NULL != connection->forward_host)
255 reusable_connection[slot].forward_host = strdup_or_die(connection->forward_host);
259 reusable_connection[slot].forward_host = NULL;
261 reusable_connection[slot].forward_port = connection->forward_port;
263 privoxy_mutex_unlock(&connection_reuse_mutex);
265 #endif /* def FEATURE_CONNECTION_SHARING */
268 /*********************************************************************
270 * Function : mark_connection_closed
272 * Description : Marks a reused connection closed.
275 * 1 : closed_connection = The connection to mark as closed.
279 *********************************************************************/
280 void mark_connection_closed(struct reusable_connection *closed_connection)
282 closed_connection->in_use = FALSE;
283 closed_connection->sfd = JB_INVALID_SOCKET;
284 freez(closed_connection->host);
285 closed_connection->port = 0;
286 closed_connection->timestamp = 0;
287 closed_connection->request_sent = 0;
288 closed_connection->response_received = 0;
289 closed_connection->keep_alive_timeout = 0;
290 closed_connection->requests_sent_total = 0;
291 closed_connection->forwarder_type = SOCKS_NONE;
292 freez(closed_connection->gateway_host);
293 closed_connection->gateway_port = 0;
294 freez(closed_connection->forward_host);
295 closed_connection->forward_port = 0;
299 #ifdef FEATURE_CONNECTION_SHARING
300 /*********************************************************************
302 * Function : forget_connection
304 * Description : Removes a previously remembered connection from
305 * the list of reusable connections.
308 * 1 : sfd = The socket belonging to the connection in question.
312 *********************************************************************/
313 void forget_connection(jb_socket sfd)
315 unsigned int slot = 0;
317 assert(sfd != JB_INVALID_SOCKET);
319 privoxy_mutex_lock(&connection_reuse_mutex);
321 for (slot = 0; slot < SZ(reusable_connection); slot++)
323 if (reusable_connection[slot].sfd == sfd)
325 assert(reusable_connection[slot].in_use);
327 log_error(LOG_LEVEL_CONNECT,
328 "Forgetting socket %d for %s:%d in slot %d.",
329 sfd, reusable_connection[slot].host,
330 reusable_connection[slot].port, slot);
331 mark_connection_closed(&reusable_connection[slot]);
336 privoxy_mutex_unlock(&connection_reuse_mutex);
339 #endif /* def FEATURE_CONNECTION_SHARING */
342 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
343 /*********************************************************************
345 * Function : connection_destination_matches
347 * Description : Determines whether a remembered connection can
348 * be reused. That is, whether the destination and
349 * the forwarding settings match.
352 * 1 : connection = The connection to check.
353 * 2 : http = The destination for the connection.
354 * 3 : fwd = The forwarder settings.
356 * Returns : TRUE for yes, FALSE otherwise.
358 *********************************************************************/
359 int connection_destination_matches(const struct reusable_connection *connection,
360 const struct http_request *http,
361 const struct forward_spec *fwd)
363 if ((connection->forwarder_type != fwd->type)
364 || (connection->gateway_port != fwd->gateway_port)
365 || (connection->forward_port != fwd->forward_port)
366 || (connection->port != http->port))
371 if (( (NULL != connection->gateway_host)
372 && (NULL != fwd->gateway_host)
373 && strcmpic(connection->gateway_host, fwd->gateway_host))
374 && (connection->gateway_host != fwd->gateway_host))
376 log_error(LOG_LEVEL_CONNECT,
377 "Gateway mismatch. Previous gateway: %s. Current gateway: %s",
378 connection->gateway_host, fwd->gateway_host);
382 if (( (NULL != connection->forward_host)
383 && (NULL != fwd->forward_host)
384 && strcmpic(connection->forward_host, fwd->forward_host))
385 && (connection->forward_host != fwd->forward_host))
387 log_error(LOG_LEVEL_CONNECT,
388 "Forwarding proxy mismatch. Previous proxy: %s. Current proxy: %s",
389 connection->forward_host, fwd->forward_host);
393 return (!strcmpic(connection->host, http->host));
396 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
399 #ifdef FEATURE_CONNECTION_SHARING
400 /*********************************************************************
402 * Function : close_unusable_connections
404 * Description : Closes remembered connections that have timed
405 * out or have been closed on the other side.
409 * Returns : Number of connections that are still alive.
411 *********************************************************************/
412 int close_unusable_connections(void)
414 unsigned int slot = 0;
415 int connections_alive = 0;
417 privoxy_mutex_lock(&connection_reuse_mutex);
419 for (slot = 0; slot < SZ(reusable_connection); slot++)
421 if (!reusable_connection[slot].in_use
422 && (JB_INVALID_SOCKET != reusable_connection[slot].sfd))
424 time_t time_open = time(NULL) - reusable_connection[slot].timestamp;
425 time_t latency = (reusable_connection[slot].response_received -
426 reusable_connection[slot].request_sent) / 2;
428 if (reusable_connection[slot].keep_alive_timeout < time_open + latency)
430 log_error(LOG_LEVEL_CONNECT,
431 "The connection to %s:%d in slot %d timed out. "
432 "Closing socket %d. Timeout is: %d. Assumed latency: %d.",
433 reusable_connection[slot].host,
434 reusable_connection[slot].port, slot,
435 reusable_connection[slot].sfd,
436 reusable_connection[slot].keep_alive_timeout,
438 close_socket(reusable_connection[slot].sfd);
439 mark_connection_closed(&reusable_connection[slot]);
441 else if (!socket_is_still_alive(reusable_connection[slot].sfd))
443 log_error(LOG_LEVEL_CONNECT,
444 "The connection to %s:%d in slot %d is no longer usable. "
445 "Closing socket %d.", reusable_connection[slot].host,
446 reusable_connection[slot].port, slot,
447 reusable_connection[slot].sfd);
448 close_socket(reusable_connection[slot].sfd);
449 mark_connection_closed(&reusable_connection[slot]);
458 privoxy_mutex_unlock(&connection_reuse_mutex);
460 return connections_alive;
465 /*********************************************************************
467 * Function : get_reusable_connection
469 * Description : Returns an open socket to a previously remembered
470 * open connection (if there is one).
473 * 1 : http = The destination for the connection.
474 * 2 : fwd = The forwarder settings.
476 * Returns : JB_INVALID_SOCKET => No reusable connection found,
477 * otherwise a usable socket.
479 *********************************************************************/
480 static jb_socket get_reusable_connection(const struct http_request *http,
481 const struct forward_spec *fwd)
483 jb_socket sfd = JB_INVALID_SOCKET;
484 unsigned int slot = 0;
486 close_unusable_connections();
488 privoxy_mutex_lock(&connection_reuse_mutex);
490 for (slot = 0; slot < SZ(reusable_connection); slot++)
492 if (!reusable_connection[slot].in_use
493 && (JB_INVALID_SOCKET != reusable_connection[slot].sfd))
495 if (connection_destination_matches(&reusable_connection[slot], http, fwd))
497 reusable_connection[slot].in_use = TRUE;
498 sfd = reusable_connection[slot].sfd;
499 log_error(LOG_LEVEL_CONNECT,
500 "Found reusable socket %d for %s:%d in slot %d. Timestamp made %d "
501 "seconds ago. Timeout: %d. Latency: %d. Requests served: %d",
502 sfd, reusable_connection[slot].host, reusable_connection[slot].port,
503 slot, time(NULL) - reusable_connection[slot].timestamp,
504 reusable_connection[slot].keep_alive_timeout,
505 (int)(reusable_connection[slot].response_received -
506 reusable_connection[slot].request_sent),
507 reusable_connection[slot].requests_sent_total);
513 privoxy_mutex_unlock(&connection_reuse_mutex);
520 /*********************************************************************
522 * Function : mark_connection_unused
524 * Description : Gives a remembered connection free for reuse.
527 * 1 : connection = The connection in question.
529 * Returns : TRUE => Socket found and marked as unused.
530 * FALSE => Socket not found.
532 *********************************************************************/
533 static int mark_connection_unused(const struct reusable_connection *connection)
535 unsigned int slot = 0;
536 int socket_found = FALSE;
538 assert(connection->sfd != JB_INVALID_SOCKET);
540 privoxy_mutex_lock(&connection_reuse_mutex);
542 for (slot = 0; slot < SZ(reusable_connection); slot++)
544 if (reusable_connection[slot].sfd == connection->sfd)
546 assert(reusable_connection[slot].in_use);
548 log_error(LOG_LEVEL_CONNECT,
549 "Marking open socket %d for %s:%d in slot %d as unused.",
550 connection->sfd, reusable_connection[slot].host,
551 reusable_connection[slot].port, slot);
552 reusable_connection[slot].in_use = 0;
553 reusable_connection[slot].timestamp = connection->timestamp;
558 privoxy_mutex_unlock(&connection_reuse_mutex);
565 /*********************************************************************
567 * Function : set_keep_alive_timeout
569 * Description : Sets the timeout after which open
570 * connections will no longer be reused.
573 * 1 : timeout = The timeout in seconds.
577 *********************************************************************/
578 void set_keep_alive_timeout(unsigned int timeout)
580 keep_alive_timeout = timeout;
582 #endif /* def FEATURE_CONNECTION_SHARING */
585 /*********************************************************************
587 * Function : forwarded_connect
589 * Description : Connect to a specified web server, possibly via
590 * a HTTP proxy and/or a SOCKS proxy.
593 * 1 : fwd = the proxies to use when connecting.
594 * 2 : http = the http request and apropos headers
595 * 3 : csp = Current client state (buffers, headers, etc...)
597 * Returns : JB_INVALID_SOCKET => failure, else it is the socket file descriptor.
599 *********************************************************************/
600 jb_socket forwarded_connect(const struct forward_spec * fwd,
601 struct http_request *http,
602 struct client_state *csp)
604 const char * dest_host;
606 jb_socket sfd = JB_INVALID_SOCKET;
608 #ifdef FEATURE_CONNECTION_SHARING
609 if ((csp->config->feature_flags & RUNTIME_FEATURE_CONNECTION_SHARING)
610 && !(csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED))
612 sfd = get_reusable_connection(http, fwd);
613 if (JB_INVALID_SOCKET != sfd)
618 #endif /* def FEATURE_CONNECTION_SHARING */
620 /* Figure out if we need to connect to the web server or a HTTP proxy. */
621 if (fwd->forward_host)
624 dest_host = fwd->forward_host;
625 dest_port = fwd->forward_port;
630 dest_host = http->host;
631 dest_port = http->port;
634 /* Connect, maybe using a SOCKS proxy */
638 case FORWARD_WEBSERVER:
639 sfd = connect_to(dest_host, dest_port, csp);
643 sfd = socks4_connect(fwd, dest_host, dest_port, csp);
647 sfd = socks5_connect(fwd, dest_host, dest_port, csp);
650 /* Should never get here */
651 log_error(LOG_LEVEL_FATAL,
652 "Internal error in forwarded_connect(). Bad proxy type: %d", fwd->type);
655 if (JB_INVALID_SOCKET != sfd)
657 log_error(LOG_LEVEL_CONNECT,
658 "Created new connection to %s:%d on socket %d.",
659 http->host, http->port, sfd);
667 /*********************************************************************
669 * Function : socks4_connect
671 * Description : Connect to the SOCKS server, and connect through
672 * it to the specified server. This handles
673 * all the SOCKS negotiation, and returns a file
674 * descriptor for a socket which can be treated as a
675 * normal (non-SOCKS) socket.
677 * Logged error messages are saved to csp->error_message
678 * and later reused by error_response() for the CGI
679 * message. strdup allocation failures are handled there.
682 * 1 : fwd = Specifies the SOCKS proxy to use.
683 * 2 : target_host = The final server to connect to.
684 * 3 : target_port = The final port to connect to.
685 * 4 : csp = Current client state (buffers, headers, etc...)
687 * Returns : JB_INVALID_SOCKET => failure, else a socket file descriptor.
689 *********************************************************************/
690 static jb_socket socks4_connect(const struct forward_spec * fwd,
691 const char * target_host,
693 struct client_state *csp)
695 unsigned long web_server_addr;
696 char buf[BUFFER_SIZE];
697 struct socks_op *c = (struct socks_op *)buf;
698 struct socks_reply *s = (struct socks_reply *)buf;
705 if ((fwd->gateway_host == NULL) || (*fwd->gateway_host == '\0'))
707 /* XXX: Shouldn't the config file parser prevent this? */
708 errstr = "NULL gateway host specified.";
712 if (fwd->gateway_port <= 0)
714 errstr = "invalid gateway port specified.";
720 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
721 csp->error_message = strdup(errstr);
723 return(JB_INVALID_SOCKET);
726 /* build a socks request for connection to the web server */
728 strlcpy(&(c->userid), socks_userid, sizeof(buf) - sizeof(struct socks_op));
730 csiz = sizeof(*c) + sizeof(socks_userid) - sizeof(c->userid) - sizeof(c->padding);
735 web_server_addr = resolve_hostname_to_ip(target_host);
736 if (web_server_addr == INADDR_NONE)
738 errstr = "could not resolve target host";
739 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s %s", errstr, target_host);
744 web_server_addr = htonl(web_server_addr);
748 web_server_addr = 0x00000001;
749 n = csiz + strlen(target_host) + 1;
753 errstr = "buffer cbuf too small.";
754 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
759 strlcpy(buf + csiz, target_host, sizeof(buf) - sizeof(struct socks_op) - csiz);
761 * What we forward to the socks4a server should have the
762 * size of socks_op, plus the length of the userid plus
763 * its \0 byte (which we don't have to add because the
764 * first byte of the userid is counted twice as it's also
765 * part of sock_op) minus the padding bytes (which are part
766 * of the userid as well), plus the length of the target_host
767 * (which is stored csiz bytes after the beginning of the buffer),
768 * plus another \0 byte.
770 assert(n == sizeof(struct socks_op) + strlen(&(c->userid)) - sizeof(c->padding) + strlen(buf + csiz) + 1);
775 /* Should never get here */
776 log_error(LOG_LEVEL_FATAL,
777 "socks4_connect: SOCKS4 impossible internal error - bad SOCKS type.");
779 return(JB_INVALID_SOCKET);
784 csp->error_message = strdup(errstr);
785 return(JB_INVALID_SOCKET);
790 c->dstport[0] = (unsigned char)((target_port >> 8 ) & 0xff);
791 c->dstport[1] = (unsigned char)((target_port ) & 0xff);
792 c->dstip[0] = (unsigned char)((web_server_addr >> 24) & 0xff);
793 c->dstip[1] = (unsigned char)((web_server_addr >> 16) & 0xff);
794 c->dstip[2] = (unsigned char)((web_server_addr >> 8) & 0xff);
795 c->dstip[3] = (unsigned char)((web_server_addr ) & 0xff);
797 /* pass the request to the socks server */
798 sfd = connect_to(fwd->gateway_host, fwd->gateway_port, csp);
800 if (sfd == JB_INVALID_SOCKET)
802 /* The error an its reason have already been logged by connect_to() */
803 return(JB_INVALID_SOCKET);
805 else if (write_socket(sfd, (char *)c, csiz))
807 errstr = "SOCKS4 negotiation write failed.";
808 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
812 else if (!data_is_available(sfd, csp->config->socket_timeout))
814 if (socket_is_still_alive(sfd))
816 errstr = "SOCKS4 negotiation timed out";
820 errstr = "SOCKS4 negotiation got aborted by the server";
822 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
826 else if (read_socket(sfd, buf, sizeof(buf)) != sizeof(*s))
828 errstr = "SOCKS4 negotiation read failed.";
829 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
836 csp->error_message = strdup(errstr);
837 return(JB_INVALID_SOCKET);
842 case SOCKS4_REQUEST_GRANTED:
844 case SOCKS4_REQUEST_REJECT:
845 errstr = "SOCKS request rejected or failed.";
848 case SOCKS4_REQUEST_IDENT_FAILED:
849 errstr = "SOCKS request rejected because "
850 "SOCKS server cannot connect to identd on the client.";
853 case SOCKS4_REQUEST_IDENT_CONFLICT:
854 errstr = "SOCKS request rejected because "
855 "the client program and identd report "
856 "different user-ids.";
861 snprintf(buf, sizeof(buf),
862 "SOCKS request rejected for reason code %d.", s->cd);
866 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
867 csp->error_message = strdup(errstr);
870 return(JB_INVALID_SOCKET);
874 /*********************************************************************
876 * Function : translate_socks5_error
878 * Description : Translates a SOCKS errors to a string.
881 * 1 : socks_error = The error code to translate.
883 * Returns : The string translation.
885 *********************************************************************/
886 static const char *translate_socks5_error(int socks_error)
890 /* XXX: these should be more descriptive */
891 case SOCKS5_REQUEST_FAILED:
892 return "SOCKS5 request failed";
893 case SOCKS5_REQUEST_DENIED:
894 return "SOCKS5 request denied";
895 case SOCKS5_REQUEST_NETWORK_UNREACHABLE:
896 return "SOCKS5 network unreachable";
897 case SOCKS5_REQUEST_HOST_UNREACHABLE:
898 return "SOCKS5 destination host unreachable";
899 case SOCKS5_REQUEST_CONNECTION_REFUSED:
900 return "SOCKS5 connection refused";
901 case SOCKS5_REQUEST_TTL_EXPIRED:
902 return "SOCKS5 TTL expired";
903 case SOCKS5_REQUEST_PROTOCOL_ERROR:
904 return "SOCKS5 client protocol error";
905 case SOCKS5_REQUEST_BAD_ADDRESS_TYPE:
906 return "SOCKS5 domain names unsupported";
907 case SOCKS5_REQUEST_GRANTED:
908 return "everything's peachy";
910 return "SOCKS5 negotiation protocol error";
914 /*********************************************************************
916 * Function : socks5_connect
918 * Description : Connect to the SOCKS server, and connect through
919 * it to the specified server. This handles
920 * all the SOCKS negotiation, and returns a file
921 * descriptor for a socket which can be treated as a
922 * normal (non-SOCKS) socket.
925 * 1 : fwd = Specifies the SOCKS proxy to use.
926 * 2 : target_host = The final server to connect to.
927 * 3 : target_port = The final port to connect to.
928 * 4 : csp = Current client state (buffers, headers, etc...)
930 * Returns : JB_INVALID_SOCKET => failure, else a socket file descriptor.
932 *********************************************************************/
933 static jb_socket socks5_connect(const struct forward_spec *fwd,
934 const char *target_host,
936 struct client_state *csp)
941 size_t client_pos = 0;
945 const char *errstr = NULL;
947 assert(fwd->gateway_host);
948 if ((fwd->gateway_host == NULL) || (*fwd->gateway_host == '\0'))
950 errstr = "NULL gateway host specified";
954 if (fwd->gateway_port <= 0)
957 * XXX: currently this can't happen because in
958 * case of invalid gateway ports we use the defaults.
959 * Of course we really shouldn't do that.
961 errstr = "invalid gateway port specified";
965 hostlen = strlen(target_host);
966 if (hostlen > (size_t)255)
968 errstr = "target host name is longer than 255 characters";
972 if ((fwd->type != SOCKS_5) && (fwd->type != SOCKS_5T))
974 /* Should never get here */
975 log_error(LOG_LEVEL_FATAL,
976 "SOCKS5 impossible internal error - bad SOCKS type");
983 assert(errstr != NULL);
984 log_error(LOG_LEVEL_CONNECT, "socks5_connect: %s", errstr);
985 csp->error_message = strdup(errstr);
986 return(JB_INVALID_SOCKET);
989 /* pass the request to the socks server */
990 sfd = connect_to(fwd->gateway_host, fwd->gateway_port, csp);
992 if (sfd == JB_INVALID_SOCKET)
994 errstr = "socks5 server unreachable";
995 log_error(LOG_LEVEL_CONNECT, "socks5_connect: %s", errstr);
996 /* Free the generic error message provided by connect_to() */
997 freez(csp->error_message);
998 csp->error_message = strdup(errstr);
999 return(JB_INVALID_SOCKET);
1003 cbuf[client_pos++] = '\x05'; /* Version */
1004 cbuf[client_pos++] = '\x01'; /* One authentication method supported */
1005 cbuf[client_pos++] = '\x00'; /* The no authentication authentication method */
1007 if (write_socket(sfd, cbuf, client_pos))
1009 errstr = "SOCKS5 negotiation write failed";
1010 csp->error_message = strdup(errstr);
1011 log_error(LOG_LEVEL_CONNECT, "%s", errstr);
1013 return(JB_INVALID_SOCKET);
1016 if (!data_is_available(sfd, csp->config->socket_timeout))
1018 if (socket_is_still_alive(sfd))
1020 errstr = "SOCKS5 negotiation timed out";
1024 errstr = "SOCKS5 negotiation got aborted by the server";
1029 if (!err && read_socket(sfd, sbuf, sizeof(sbuf)) != 2)
1031 errstr = "SOCKS5 negotiation read failed";
1035 if (!err && (sbuf[0] != '\x05'))
1037 errstr = "SOCKS5 negotiation protocol version error";
1041 if (!err && (sbuf[1] == '\xff'))
1043 errstr = "SOCKS5 authentication required";
1047 if (!err && (sbuf[1] != '\x00'))
1049 errstr = "SOCKS5 negotiation protocol error";
1055 assert(errstr != NULL);
1056 log_error(LOG_LEVEL_CONNECT, "socks5_connect: %s", errstr);
1057 csp->error_message = strdup(errstr);
1060 return(JB_INVALID_SOCKET);
1064 cbuf[client_pos++] = '\x05'; /* Version */
1065 cbuf[client_pos++] = '\x01'; /* TCP connect */
1066 cbuf[client_pos++] = '\x00'; /* Reserved, must be 0x00 */
1067 cbuf[client_pos++] = '\x03'; /* Address is domain name */
1068 cbuf[client_pos++] = (char)(hostlen & 0xffu);
1069 assert(sizeof(cbuf) - client_pos > (size_t)255);
1070 /* Using strncpy because we really want the nul byte padding. */
1071 strncpy(cbuf + client_pos, target_host, sizeof(cbuf) - client_pos);
1072 client_pos += (hostlen & 0xffu);
1073 cbuf[client_pos++] = (char)((target_port >> 8) & 0xff);
1074 cbuf[client_pos++] = (char)((target_port ) & 0xff);
1076 if (write_socket(sfd, cbuf, client_pos))
1078 errstr = "SOCKS5 negotiation write failed";
1079 csp->error_message = strdup(errstr);
1080 log_error(LOG_LEVEL_CONNECT, "%s", errstr);
1083 return(JB_INVALID_SOCKET);
1087 * Optimistically send the HTTP request with the initial
1088 * SOCKS request if the user enabled the use of Tor extensions,
1089 * the CONNECT method isn't being used (in which case the client
1090 * doesn't send data until it gets our 200 response) and the
1091 * client request has actually been completely read already.
1093 if ((fwd->type == SOCKS_5T) && (csp->http->ssl == 0)
1094 && (csp->flags & CSP_FLAG_CLIENT_REQUEST_COMPLETELY_READ))
1096 char *client_headers = list_to_text(csp->headers);
1097 size_t header_length;
1099 if (client_headers == NULL)
1101 log_error(LOG_LEVEL_FATAL, "Out of memory rebuilding client headers");
1103 list_remove_all(csp->headers);
1104 header_length= strlen(client_headers);
1106 log_error(LOG_LEVEL_CONNECT,
1107 "Optimistically sending %d bytes of client headers intended for %s",
1108 header_length, csp->http->hostport);
1110 if (write_socket(sfd, client_headers, header_length))
1112 log_error(LOG_LEVEL_CONNECT,
1113 "optimistically writing header to: %s failed: %E", csp->http->hostport);
1114 freez(client_headers);
1115 return(JB_INVALID_SOCKET);
1117 freez(client_headers);
1118 if (csp->expected_client_content_length != 0)
1120 unsigned long long buffered_request_bytes =
1121 (unsigned long long)(csp->client_iob->eod - csp->client_iob->cur);
1122 log_error(LOG_LEVEL_CONNECT,
1123 "Optimistically sending %d bytes of client body. Expected %d",
1124 csp->expected_client_content_length, buffered_request_bytes);
1125 assert(csp->expected_client_content_length == buffered_request_bytes);
1126 if (write_socket(sfd, csp->client_iob->cur, buffered_request_bytes))
1128 log_error(LOG_LEVEL_CONNECT,
1129 "optimistically writing %d bytes of client body to: %s failed: %E",
1130 buffered_request_bytes, csp->http->hostport);
1131 return(JB_INVALID_SOCKET);
1133 clear_iob(csp->client_iob);
1137 server_size = read_socket(sfd, sbuf, sizeof(sbuf));
1138 if (server_size != sizeof(sbuf))
1140 errstr = "SOCKS5 negotiation read failed";
1144 if (sbuf[0] != '\x05')
1146 errstr = "SOCKS5 negotiation protocol version error";
1148 else if (sbuf[2] != '\x00')
1150 errstr = "SOCKS5 negotiation protocol error";
1152 else if (sbuf[1] != SOCKS5_REQUEST_GRANTED)
1154 errstr = translate_socks5_error(sbuf[1]);
1162 assert(errstr != NULL);
1163 csp->error_message = strdup(errstr);
1164 log_error(LOG_LEVEL_CONNECT, "socks5_connect: %s", errstr);
1168 return(JB_INVALID_SOCKET);