1 const char gateway_rcs[] = "$Id: gateway.c,v 1.71 2011/02/19 13:56:22 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"
69 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
75 #endif /* def __GLIBC__ */
76 #endif /* HAVE_POLL */
77 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
79 const char gateway_h_rcs[] = GATEWAY_H_VERSION;
81 static jb_socket socks4_connect(const struct forward_spec * fwd,
82 const char * target_host,
84 struct client_state *csp);
86 static jb_socket socks5_connect(const struct forward_spec *fwd,
87 const char *target_host,
89 struct client_state *csp);
92 SOCKS4_REQUEST_GRANTED = 90,
93 SOCKS4_REQUEST_REJECT = 91,
94 SOCKS4_REQUEST_IDENT_FAILED = 92,
95 SOCKS4_REQUEST_IDENT_CONFLICT = 93
99 SOCKS5_REQUEST_GRANTED = 0,
100 SOCKS5_REQUEST_FAILED = 1,
101 SOCKS5_REQUEST_DENIED = 2,
102 SOCKS5_REQUEST_NETWORK_UNREACHABLE = 3,
103 SOCKS5_REQUEST_HOST_UNREACHABLE = 4,
104 SOCKS5_REQUEST_CONNECTION_REFUSED = 5,
105 SOCKS5_REQUEST_TTL_EXPIRED = 6,
106 SOCKS5_REQUEST_PROTOCOL_ERROR = 7,
107 SOCKS5_REQUEST_BAD_ADDRESS_TYPE = 8
110 /* structure of a socks client operation */
112 unsigned char vn; /* socks version number */
113 unsigned char cd; /* command code */
114 unsigned char dstport[2]; /* destination port */
115 unsigned char dstip[4]; /* destination address */
116 char userid; /* first byte of userid */
117 char padding[3]; /* make sure sizeof(struct socks_op) is endian-independent. */
118 /* more bytes of the userid follow, terminated by a NULL */
121 /* structure of a socks server reply */
123 unsigned char vn; /* socks version number */
124 unsigned char cd; /* command code */
125 unsigned char dstport[2]; /* destination port */
126 unsigned char dstip[4]; /* destination address */
129 static const char socks_userid[] = "anonymous";
131 #ifdef FEATURE_CONNECTION_SHARING
133 #define MAX_REUSABLE_CONNECTIONS 100
134 static unsigned int keep_alive_timeout = DEFAULT_KEEP_ALIVE_TIMEOUT;
136 static struct reusable_connection reusable_connection[MAX_REUSABLE_CONNECTIONS];
137 static int mark_connection_unused(const struct reusable_connection *connection);
139 /*********************************************************************
141 * Function : initialize_reusable_connections
143 * Description : Initializes the reusable_connection structures.
144 * Must be called with connection_reuse_mutex locked.
150 *********************************************************************/
151 extern void initialize_reusable_connections(void)
153 unsigned int slot = 0;
155 #if !defined(HAVE_POLL) && !defined(_WIN32)
156 log_error(LOG_LEVEL_INFO,
157 "Detecting already dead connections might not work "
158 "correctly on your platform. In case of problems, "
159 "unset the keep-alive-timeout option.");
162 for (slot = 0; slot < SZ(reusable_connection); slot++)
164 mark_connection_closed(&reusable_connection[slot]);
167 log_error(LOG_LEVEL_CONNECT, "Initialized %d socket slots.", slot);
171 /*********************************************************************
173 * Function : remember_connection
175 * Description : Remembers a server connection for reuse later on.
178 * 1 : connection = The server connection to remember.
182 *********************************************************************/
183 void remember_connection(const struct reusable_connection *connection)
185 unsigned int slot = 0;
186 int free_slot_found = FALSE;
188 assert(NULL != connection);
189 assert(connection->sfd != JB_INVALID_SOCKET);
191 if (mark_connection_unused(connection))
196 privoxy_mutex_lock(&connection_reuse_mutex);
198 /* Find free socket slot. */
199 for (slot = 0; slot < SZ(reusable_connection); slot++)
201 if (reusable_connection[slot].sfd == JB_INVALID_SOCKET)
203 assert(reusable_connection[slot].in_use == 0);
204 log_error(LOG_LEVEL_CONNECT,
205 "Remembering socket %d for %s:%d in slot %d.",
206 connection->sfd, connection->host, connection->port, slot);
207 free_slot_found = TRUE;
212 if (!free_slot_found)
214 log_error(LOG_LEVEL_CONNECT,
215 "No free slots found to remembering socket for %s:%d. Last slot %d.",
216 connection->host, connection->port, slot);
217 privoxy_mutex_unlock(&connection_reuse_mutex);
218 close_socket(connection->sfd);
222 assert(NULL != connection->host);
223 reusable_connection[slot].host = strdup(connection->host);
224 if (NULL == reusable_connection[slot].host)
226 log_error(LOG_LEVEL_FATAL, "Out of memory saving socket.");
228 reusable_connection[slot].sfd = connection->sfd;
229 reusable_connection[slot].port = connection->port;
230 reusable_connection[slot].in_use = 0;
231 reusable_connection[slot].timestamp = connection->timestamp;
232 reusable_connection->request_sent = connection->request_sent;
233 reusable_connection->response_received = connection->response_received;
234 reusable_connection[slot].keep_alive_timeout = connection->keep_alive_timeout;
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(connection->gateway_host);
246 if (NULL == reusable_connection[slot].gateway_host)
248 log_error(LOG_LEVEL_FATAL, "Out of memory saving gateway_host.");
253 reusable_connection[slot].gateway_host = NULL;
255 reusable_connection[slot].gateway_port = connection->gateway_port;
257 if (NULL != connection->forward_host)
259 reusable_connection[slot].forward_host = strdup(connection->forward_host);
260 if (NULL == reusable_connection[slot].forward_host)
262 log_error(LOG_LEVEL_FATAL, "Out of memory saving forward_host.");
267 reusable_connection[slot].forward_host = NULL;
269 reusable_connection[slot].forward_port = connection->forward_port;
271 privoxy_mutex_unlock(&connection_reuse_mutex);
273 #endif /* def FEATURE_CONNECTION_SHARING */
276 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
277 /*********************************************************************
279 * Function : mark_connection_closed
281 * Description : Marks a reused connection closed.
284 * 1 : closed_connection = The connection to mark as closed.
288 *********************************************************************/
289 void mark_connection_closed(struct reusable_connection *closed_connection)
291 closed_connection->in_use = FALSE;
292 closed_connection->sfd = JB_INVALID_SOCKET;
293 freez(closed_connection->host);
294 closed_connection->port = 0;
295 closed_connection->timestamp = 0;
296 closed_connection->request_sent = 0;
297 closed_connection->response_received = 0;
298 closed_connection->keep_alive_timeout = 0;
299 closed_connection->forwarder_type = SOCKS_NONE;
300 freez(closed_connection->gateway_host);
301 closed_connection->gateway_port = 0;
302 freez(closed_connection->forward_host);
303 closed_connection->forward_port = 0;
305 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
308 #ifdef FEATURE_CONNECTION_SHARING
309 /*********************************************************************
311 * Function : forget_connection
313 * Description : Removes a previously remembered connection from
314 * the list of reusable connections.
317 * 1 : sfd = The socket belonging to the connection in question.
321 *********************************************************************/
322 void forget_connection(jb_socket sfd)
324 unsigned int slot = 0;
326 assert(sfd != JB_INVALID_SOCKET);
328 privoxy_mutex_lock(&connection_reuse_mutex);
330 for (slot = 0; slot < SZ(reusable_connection); slot++)
332 if (reusable_connection[slot].sfd == sfd)
334 assert(reusable_connection[slot].in_use);
336 log_error(LOG_LEVEL_CONNECT,
337 "Forgetting socket %d for %s:%d in slot %d.",
338 sfd, reusable_connection[slot].host,
339 reusable_connection[slot].port, slot);
340 mark_connection_closed(&reusable_connection[slot]);
341 privoxy_mutex_unlock(&connection_reuse_mutex);
347 log_error(LOG_LEVEL_CONNECT,
348 "Socket %d already forgotten or never remembered.", sfd);
350 privoxy_mutex_unlock(&connection_reuse_mutex);
352 #endif /* def FEATURE_CONNECTION_SHARING */
355 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
356 /*********************************************************************
358 * Function : connection_destination_matches
360 * Description : Determines whether a remembered connection can
361 * be reused. That is, whether the destination and
362 * the forwarding settings match.
365 * 1 : connection = The connection to check.
366 * 2 : http = The destination for the connection.
367 * 3 : fwd = The forwarder settings.
369 * Returns : TRUE for yes, FALSE otherwise.
371 *********************************************************************/
372 int connection_destination_matches(const struct reusable_connection *connection,
373 const struct http_request *http,
374 const struct forward_spec *fwd)
376 if ((connection->forwarder_type != fwd->type)
377 || (connection->gateway_port != fwd->gateway_port)
378 || (connection->forward_port != fwd->forward_port)
379 || (connection->port != http->port))
384 if (( (NULL != connection->gateway_host)
385 && (NULL != fwd->gateway_host)
386 && strcmpic(connection->gateway_host, fwd->gateway_host))
387 && (connection->gateway_host != fwd->gateway_host))
389 log_error(LOG_LEVEL_CONNECT,
390 "Gateway mismatch. Previous gateway: %s. Current gateway: %s",
391 connection->gateway_host, fwd->gateway_host);
395 if (( (NULL != connection->forward_host)
396 && (NULL != fwd->forward_host)
397 && strcmpic(connection->forward_host, fwd->forward_host))
398 && (connection->forward_host != fwd->forward_host))
400 log_error(LOG_LEVEL_CONNECT,
401 "Forwarding proxy mismatch. Previous proxy: %s. Current proxy: %s",
402 connection->forward_host, fwd->forward_host);
406 return (!strcmpic(connection->host, http->host));
409 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
412 #ifdef FEATURE_CONNECTION_SHARING
413 /*********************************************************************
415 * Function : close_unusable_connections
417 * Description : Closes remembered connections that have timed
418 * out or have been closed on the other side.
422 * Returns : Number of connections that are still alive.
424 *********************************************************************/
425 int close_unusable_connections(void)
427 unsigned int slot = 0;
428 int connections_alive = 0;
430 privoxy_mutex_lock(&connection_reuse_mutex);
432 for (slot = 0; slot < SZ(reusable_connection); slot++)
434 if (!reusable_connection[slot].in_use
435 && (JB_INVALID_SOCKET != reusable_connection[slot].sfd))
437 time_t time_open = time(NULL) - reusable_connection[slot].timestamp;
438 time_t latency = (reusable_connection[slot].response_received -
439 reusable_connection[slot].request_sent) / 2;
441 if (reusable_connection[slot].keep_alive_timeout < time_open + latency)
443 log_error(LOG_LEVEL_CONNECT,
444 "The connection to %s:%d in slot %d timed out. "
445 "Closing socket %d. Timeout is: %d. Assumed latency: %d.",
446 reusable_connection[slot].host,
447 reusable_connection[slot].port, slot,
448 reusable_connection[slot].sfd,
449 reusable_connection[slot].keep_alive_timeout,
451 close_socket(reusable_connection[slot].sfd);
452 mark_connection_closed(&reusable_connection[slot]);
454 else if (!socket_is_still_alive(reusable_connection[slot].sfd))
456 log_error(LOG_LEVEL_CONNECT,
457 "The connection to %s:%d in slot %d is no longer usable. "
458 "Closing socket %d.", reusable_connection[slot].host,
459 reusable_connection[slot].port, slot,
460 reusable_connection[slot].sfd);
461 close_socket(reusable_connection[slot].sfd);
462 mark_connection_closed(&reusable_connection[slot]);
471 privoxy_mutex_unlock(&connection_reuse_mutex);
473 return connections_alive;
478 /*********************************************************************
480 * Function : get_reusable_connection
482 * Description : Returns an open socket to a previously remembered
483 * open connection (if there is one).
486 * 1 : http = The destination for the connection.
487 * 2 : fwd = The forwarder settings.
489 * Returns : JB_INVALID_SOCKET => No reusable connection found,
490 * otherwise a usable socket.
492 *********************************************************************/
493 static jb_socket get_reusable_connection(const struct http_request *http,
494 const struct forward_spec *fwd)
496 jb_socket sfd = JB_INVALID_SOCKET;
497 unsigned int slot = 0;
499 close_unusable_connections();
501 privoxy_mutex_lock(&connection_reuse_mutex);
503 for (slot = 0; slot < SZ(reusable_connection); slot++)
505 if (!reusable_connection[slot].in_use
506 && (JB_INVALID_SOCKET != reusable_connection[slot].sfd))
508 if (connection_destination_matches(&reusable_connection[slot], http, fwd))
510 reusable_connection[slot].in_use = TRUE;
511 sfd = reusable_connection[slot].sfd;
512 log_error(LOG_LEVEL_CONNECT,
513 "Found reusable socket %d for %s:%d in slot %d. "
514 "Timestamp made %d seconds ago. Timeout: %d. Latency: %d.",
515 sfd, reusable_connection[slot].host, reusable_connection[slot].port,
516 slot, time(NULL) - reusable_connection[slot].timestamp,
517 reusable_connection[slot].keep_alive_timeout,
518 (int)(reusable_connection[slot].response_received -
519 reusable_connection[slot].request_sent));
525 privoxy_mutex_unlock(&connection_reuse_mutex);
532 /*********************************************************************
534 * Function : mark_connection_unused
536 * Description : Gives a remembered connection free for reuse.
539 * 1 : connection = The connection in question.
541 * Returns : TRUE => Socket found and marked as unused.
542 * FALSE => Socket not found.
544 *********************************************************************/
545 static int mark_connection_unused(const struct reusable_connection *connection)
547 unsigned int slot = 0;
548 int socket_found = FALSE;
550 assert(connection->sfd != JB_INVALID_SOCKET);
552 privoxy_mutex_lock(&connection_reuse_mutex);
554 for (slot = 0; slot < SZ(reusable_connection); slot++)
556 if (reusable_connection[slot].sfd == connection->sfd)
558 assert(reusable_connection[slot].in_use);
560 log_error(LOG_LEVEL_CONNECT,
561 "Marking open socket %d for %s:%d in slot %d as unused.",
562 connection->sfd, reusable_connection[slot].host,
563 reusable_connection[slot].port, slot);
564 reusable_connection[slot].in_use = 0;
565 reusable_connection[slot].timestamp = connection->timestamp;
570 privoxy_mutex_unlock(&connection_reuse_mutex);
577 /*********************************************************************
579 * Function : set_keep_alive_timeout
581 * Description : Sets the timeout after which open
582 * connections will no longer be reused.
585 * 1 : timeout = The timeout in seconds.
589 *********************************************************************/
590 void set_keep_alive_timeout(unsigned int timeout)
592 keep_alive_timeout = timeout;
594 #endif /* def FEATURE_CONNECTION_SHARING */
597 /*********************************************************************
599 * Function : forwarded_connect
601 * Description : Connect to a specified web server, possibly via
602 * a HTTP proxy and/or a SOCKS proxy.
605 * 1 : fwd = the proxies to use when connecting.
606 * 2 : http = the http request and apropos headers
607 * 3 : csp = Current client state (buffers, headers, etc...)
609 * Returns : JB_INVALID_SOCKET => failure, else it is the socket file descriptor.
611 *********************************************************************/
612 jb_socket forwarded_connect(const struct forward_spec * fwd,
613 struct http_request *http,
614 struct client_state *csp)
616 const char * dest_host;
618 jb_socket sfd = JB_INVALID_SOCKET;
620 #ifdef FEATURE_CONNECTION_SHARING
621 if ((csp->config->feature_flags & RUNTIME_FEATURE_CONNECTION_SHARING)
622 && !(csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED))
624 sfd = get_reusable_connection(http, fwd);
625 if (JB_INVALID_SOCKET != sfd)
630 #endif /* def FEATURE_CONNECTION_SHARING */
632 /* Figure out if we need to connect to the web server or a HTTP proxy. */
633 if (fwd->forward_host)
636 dest_host = fwd->forward_host;
637 dest_port = fwd->forward_port;
642 dest_host = http->host;
643 dest_port = http->port;
646 /* Connect, maybe using a SOCKS proxy */
650 sfd = connect_to(dest_host, dest_port, csp);
654 sfd = socks4_connect(fwd, dest_host, dest_port, csp);
657 sfd = socks5_connect(fwd, dest_host, dest_port, csp);
660 /* Should never get here */
661 log_error(LOG_LEVEL_FATAL,
662 "SOCKS4 impossible internal error - bad SOCKS type.");
665 if (JB_INVALID_SOCKET != sfd)
667 log_error(LOG_LEVEL_CONNECT,
668 "Created new connection to %s:%d on socket %d.",
669 http->host, http->port, sfd);
677 /*********************************************************************
679 * Function : socks4_connect
681 * Description : Connect to the SOCKS server, and connect through
682 * it to the specified server. This handles
683 * all the SOCKS negotiation, and returns a file
684 * descriptor for a socket which can be treated as a
685 * normal (non-SOCKS) socket.
687 * Logged error messages are saved to csp->error_message
688 * and later reused by error_response() for the CGI
689 * message. strdup allocation failures are handled there.
692 * 1 : fwd = Specifies the SOCKS proxy to use.
693 * 2 : target_host = The final server to connect to.
694 * 3 : target_port = The final port to connect to.
695 * 4 : csp = Current client state (buffers, headers, etc...)
697 * Returns : JB_INVALID_SOCKET => failure, else a socket file descriptor.
699 *********************************************************************/
700 static jb_socket socks4_connect(const struct forward_spec * fwd,
701 const char * target_host,
703 struct client_state *csp)
705 unsigned long web_server_addr;
706 char buf[BUFFER_SIZE];
707 struct socks_op *c = (struct socks_op *)buf;
708 struct socks_reply *s = (struct socks_reply *)buf;
715 if ((fwd->gateway_host == NULL) || (*fwd->gateway_host == '\0'))
717 /* XXX: Shouldn't the config file parser prevent this? */
718 errstr = "NULL gateway host specified.";
722 if (fwd->gateway_port <= 0)
724 errstr = "invalid gateway port specified.";
730 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
731 csp->error_message = strdup(errstr);
733 return(JB_INVALID_SOCKET);
736 /* build a socks request for connection to the web server */
738 strlcpy(&(c->userid), socks_userid, sizeof(buf) - sizeof(struct socks_op));
740 csiz = sizeof(*c) + sizeof(socks_userid) - sizeof(c->userid) - sizeof(c->padding);
745 web_server_addr = resolve_hostname_to_ip(target_host);
746 if (web_server_addr == INADDR_NONE)
748 errstr = "could not resolve target host";
749 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s %s", errstr, target_host);
754 web_server_addr = htonl(web_server_addr);
758 web_server_addr = 0x00000001;
759 n = csiz + strlen(target_host) + 1;
763 errstr = "buffer cbuf too small.";
764 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
769 strlcpy(buf + csiz, target_host, sizeof(buf) - sizeof(struct socks_op) - csiz);
771 * What we forward to the socks4a server should have the
772 * size of socks_op, plus the length of the userid plus
773 * its \0 byte (which we don't have to add because the
774 * first byte of the userid is counted twice as it's also
775 * part of sock_op) minus the padding bytes (which are part
776 * of the userid as well), plus the length of the target_host
777 * (which is stored csiz bytes after the beginning of the buffer),
778 * plus another \0 byte.
780 assert(n == sizeof(struct socks_op) + strlen(&(c->userid)) - sizeof(c->padding) + strlen(buf + csiz) + 1);
785 /* Should never get here */
786 log_error(LOG_LEVEL_FATAL,
787 "socks4_connect: SOCKS4 impossible internal error - bad SOCKS type.");
789 return(JB_INVALID_SOCKET);
794 csp->error_message = strdup(errstr);
795 return(JB_INVALID_SOCKET);
800 c->dstport[0] = (unsigned char)((target_port >> 8 ) & 0xff);
801 c->dstport[1] = (unsigned char)((target_port ) & 0xff);
802 c->dstip[0] = (unsigned char)((web_server_addr >> 24 ) & 0xff);
803 c->dstip[1] = (unsigned char)((web_server_addr >> 16 ) & 0xff);
804 c->dstip[2] = (unsigned char)((web_server_addr >> 8 ) & 0xff);
805 c->dstip[3] = (unsigned char)((web_server_addr ) & 0xff);
807 /* pass the request to the socks server */
808 sfd = connect_to(fwd->gateway_host, fwd->gateway_port, csp);
810 if (sfd == JB_INVALID_SOCKET)
812 /* The error an its reason have already been logged by connect_to() */
813 return(JB_INVALID_SOCKET);
815 else if (!data_is_available(sfd, csp->config->socket_timeout))
817 if (socket_is_still_alive(sfd))
819 errstr = "SOCKS4 negotiation timed out";
823 errstr = "SOCKS4 negotiation got aborted by the server";
825 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
829 else if (write_socket(sfd, (char *)c, csiz))
831 errstr = "SOCKS4 negotiation write failed.";
832 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
836 else if (read_socket(sfd, buf, sizeof(buf)) != sizeof(*s))
838 errstr = "SOCKS4 negotiation read failed.";
839 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
846 csp->error_message = strdup(errstr);
847 return(JB_INVALID_SOCKET);
852 case SOCKS4_REQUEST_GRANTED:
854 case SOCKS4_REQUEST_REJECT:
855 errstr = "SOCKS request rejected or failed.";
858 case SOCKS4_REQUEST_IDENT_FAILED:
859 errstr = "SOCKS request rejected because "
860 "SOCKS server cannot connect to identd on the client.";
863 case SOCKS4_REQUEST_IDENT_CONFLICT:
864 errstr = "SOCKS request rejected because "
865 "the client program and identd report "
866 "different user-ids.";
871 snprintf(buf, sizeof(buf),
872 "SOCKS request rejected for reason code %d.", s->cd);
876 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
877 csp->error_message = strdup(errstr);
880 return(JB_INVALID_SOCKET);
884 /*********************************************************************
886 * Function : translate_socks5_error
888 * Description : Translates a SOCKS errors to a string.
891 * 1 : socks_error = The error code to translate.
893 * Returns : The string translation.
895 *********************************************************************/
896 static const char *translate_socks5_error(int socks_error)
900 /* XXX: these should be more descriptive */
901 case SOCKS5_REQUEST_FAILED:
902 return "SOCKS5 request failed";
903 case SOCKS5_REQUEST_DENIED:
904 return "SOCKS5 request denied";
905 case SOCKS5_REQUEST_NETWORK_UNREACHABLE:
906 return "SOCKS5 network unreachable";
907 case SOCKS5_REQUEST_HOST_UNREACHABLE:
908 return "SOCKS5 host unreachable";
909 case SOCKS5_REQUEST_CONNECTION_REFUSED:
910 return "SOCKS5 connection refused";
911 case SOCKS5_REQUEST_TTL_EXPIRED:
912 return "SOCKS5 TTL expired";
913 case SOCKS5_REQUEST_PROTOCOL_ERROR:
914 return "SOCKS5 client protocol error";
915 case SOCKS5_REQUEST_BAD_ADDRESS_TYPE:
916 return "SOCKS5 domain names unsupported";
917 case SOCKS5_REQUEST_GRANTED:
918 return "everything's peachy";
920 return "SOCKS5 negotiation protocol error";
924 /*********************************************************************
926 * Function : socks5_connect
928 * Description : Connect to the SOCKS server, and connect through
929 * it to the specified server. This handles
930 * all the SOCKS negotiation, and returns a file
931 * descriptor for a socket which can be treated as a
932 * normal (non-SOCKS) socket.
935 * 1 : fwd = Specifies the SOCKS proxy to use.
936 * 2 : target_host = The final server to connect to.
937 * 3 : target_port = The final port to connect to.
938 * 4 : csp = Current client state (buffers, headers, etc...)
940 * Returns : JB_INVALID_SOCKET => failure, else a socket file descriptor.
942 *********************************************************************/
943 static jb_socket socks5_connect(const struct forward_spec *fwd,
944 const char *target_host,
946 struct client_state *csp)
951 size_t client_pos = 0;
955 const char *errstr = NULL;
957 assert(fwd->gateway_host);
958 if ((fwd->gateway_host == NULL) || (*fwd->gateway_host == '\0'))
960 errstr = "NULL gateway host specified";
964 if (fwd->gateway_port <= 0)
967 * XXX: currently this can't happen because in
968 * case of invalid gateway ports we use the defaults.
969 * Of course we really shouldn't do that.
971 errstr = "invalid gateway port specified";
975 hostlen = strlen(target_host);
976 if (hostlen > (size_t)255)
978 errstr = "target host name is longer than 255 characters";
982 if (fwd->type != SOCKS_5)
984 /* Should never get here */
985 log_error(LOG_LEVEL_FATAL,
986 "SOCKS5 impossible internal error - bad SOCKS type");
993 assert(errstr != NULL);
994 log_error(LOG_LEVEL_CONNECT, "socks5_connect: %s", errstr);
995 csp->error_message = strdup(errstr);
996 return(JB_INVALID_SOCKET);
999 /* pass the request to the socks server */
1000 sfd = connect_to(fwd->gateway_host, fwd->gateway_port, csp);
1002 if (sfd == JB_INVALID_SOCKET)
1004 errstr = "socks5 server unreachable";
1005 log_error(LOG_LEVEL_CONNECT, "socks5_connect: %s", errstr);
1006 csp->error_message = strdup(errstr);
1007 return(JB_INVALID_SOCKET);
1011 cbuf[client_pos++] = '\x05'; /* Version */
1012 cbuf[client_pos++] = '\x01'; /* One authentication method supported */
1013 cbuf[client_pos++] = '\x00'; /* The no authentication authentication method */
1015 if (write_socket(sfd, cbuf, client_pos))
1017 errstr = "SOCKS5 negotiation write failed";
1018 csp->error_message = strdup(errstr);
1019 log_error(LOG_LEVEL_CONNECT, "%s", errstr);
1021 return(JB_INVALID_SOCKET);
1024 if (!data_is_available(sfd, csp->config->socket_timeout))
1026 if (socket_is_still_alive(sfd))
1028 errstr = "SOCKS5 negotiation timed out";
1032 errstr = "SOCKS5 negotiation got aborted by the server";
1037 if (!err && read_socket(sfd, sbuf, sizeof(sbuf)) != 2)
1039 errstr = "SOCKS5 negotiation read failed";
1043 if (!err && (sbuf[0] != '\x05'))
1045 errstr = "SOCKS5 negotiation protocol version error";
1049 if (!err && (sbuf[1] == '\xff'))
1051 errstr = "SOCKS5 authentication required";
1055 if (!err && (sbuf[1] != '\x00'))
1057 errstr = "SOCKS5 negotiation protocol error";
1063 assert(errstr != NULL);
1064 log_error(LOG_LEVEL_CONNECT, "socks5_connect: %s", errstr);
1065 csp->error_message = strdup(errstr);
1068 return(JB_INVALID_SOCKET);
1072 cbuf[client_pos++] = '\x05'; /* Version */
1073 cbuf[client_pos++] = '\x01'; /* TCP connect */
1074 cbuf[client_pos++] = '\x00'; /* Reserved, must be 0x00 */
1075 cbuf[client_pos++] = '\x03'; /* Address is domain name */
1076 cbuf[client_pos++] = (char)(hostlen & 0xffu);
1077 assert(sizeof(cbuf) - client_pos > (size_t)255);
1078 /* Using strncpy because we really want the nul byte padding. */
1079 strncpy(cbuf + client_pos, target_host, sizeof(cbuf) - client_pos);
1080 client_pos += (hostlen & 0xffu);
1081 cbuf[client_pos++] = (char)((target_port >> 8) & 0xff);
1082 cbuf[client_pos++] = (char)((target_port ) & 0xff);
1084 if (write_socket(sfd, cbuf, client_pos))
1086 errstr = "SOCKS5 negotiation read failed";
1087 csp->error_message = strdup(errstr);
1088 log_error(LOG_LEVEL_CONNECT, "%s", errstr);
1091 return(JB_INVALID_SOCKET);
1094 server_size = read_socket(sfd, sbuf, sizeof(sbuf));
1095 if (server_size < 3)
1097 errstr = "SOCKS5 negotiation read failed";
1100 else if (server_size > 20)
1102 /* This is somewhat unexpected but doesn't realy matter. */
1103 log_error(LOG_LEVEL_CONNECT, "socks5_connect: read %d bytes "
1104 "from socks server. Would have accepted up to %d.",
1105 server_size, sizeof(sbuf));
1108 if (!err && (sbuf[0] != '\x05'))
1110 errstr = "SOCKS5 negotiation protocol version error";
1114 if (!err && (sbuf[2] != '\x00'))
1116 errstr = "SOCKS5 negotiation protocol error";
1122 if (sbuf[1] == SOCKS5_REQUEST_GRANTED)
1126 errstr = translate_socks5_error(sbuf[1]);
1129 assert(errstr != NULL);
1130 csp->error_message = strdup(errstr);
1131 log_error(LOG_LEVEL_CONNECT, "socks5_connect: %s", errstr);
1135 return(JB_INVALID_SOCKET);