1 const char gateway_rcs[] = "$Id: gateway.c,v 1.62 2009/09/22 11:35:52 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 #define SOCKS_REQUEST_GRANTED 90
93 #define SOCKS_REQUEST_REJECT 91
94 #define SOCKS_REQUEST_IDENT_FAILED 92
95 #define SOCKS_REQUEST_IDENT_CONFLICT 93
97 #define SOCKS5_REQUEST_GRANTED 0
98 #define SOCKS5_REQUEST_FAILED 1
99 #define SOCKS5_REQUEST_DENIED 2
100 #define SOCKS5_REQUEST_NETWORK_UNREACHABLE 3
101 #define SOCKS5_REQUEST_HOST_UNREACHABLE 4
102 #define SOCKS5_REQUEST_CONNECTION_REFUSED 5
103 #define SOCKS5_REQUEST_TTL_EXPIRED 6
104 #define SOCKS5_REQUEST_PROTOCOL_ERROR 7
105 #define SOCKS5_REQUEST_BAD_ADDRESS_TYPE 8
107 /* structure of a socks client operation */
109 unsigned char vn; /* socks version number */
110 unsigned char cd; /* command code */
111 unsigned char dstport[2]; /* destination port */
112 unsigned char dstip[4]; /* destination address */
113 char userid; /* first byte of userid */
114 char padding[3]; /* make sure sizeof(struct socks_op) is endian-independent. */
115 /* more bytes of the userid follow, terminated by a NULL */
118 /* structure of a socks server reply */
120 unsigned char vn; /* socks version number */
121 unsigned char cd; /* command code */
122 unsigned char dstport[2]; /* destination port */
123 unsigned char dstip[4]; /* destination address */
126 static const char socks_userid[] = "anonymous";
128 #ifdef FEATURE_CONNECTION_SHARING
130 #define MAX_REUSABLE_CONNECTIONS 100
131 static unsigned int keep_alive_timeout = DEFAULT_KEEP_ALIVE_TIMEOUT;
133 static struct reusable_connection reusable_connection[MAX_REUSABLE_CONNECTIONS];
134 static int mark_connection_unused(const struct reusable_connection *connection);
136 /*********************************************************************
138 * Function : initialize_reusable_connections
140 * Description : Initializes the reusable_connection structures.
141 * Must be called with connection_reuse_mutex locked.
147 *********************************************************************/
148 extern void initialize_reusable_connections(void)
150 unsigned int slot = 0;
152 #if !defined(HAVE_POLL) && !defined(_WIN32)
153 log_error(LOG_LEVEL_INFO,
154 "Detecting already dead connections might not work "
155 "correctly on your platform. In case of problems, "
156 "unset the keep-alive-timeout option.");
159 for (slot = 0; slot < SZ(reusable_connection); slot++)
161 mark_connection_closed(&reusable_connection[slot]);
164 log_error(LOG_LEVEL_CONNECT, "Initialized %d socket slots.", slot);
168 /*********************************************************************
170 * Function : remember_connection
172 * Description : Remembers a connection for reuse later on.
175 * 1 : csp = Current client state (buffers, headers, etc...)
176 * 2 : fwd = The forwarder settings used.
180 *********************************************************************/
181 void remember_connection(const struct client_state *csp, const struct forward_spec *fwd)
183 unsigned int slot = 0;
184 int free_slot_found = FALSE;
185 const struct reusable_connection *connection = &csp->server_connection;
186 const struct http_request *http = csp->http;
188 assert(connection->sfd != JB_INVALID_SOCKET);
190 if (mark_connection_unused(connection))
195 privoxy_mutex_lock(&connection_reuse_mutex);
197 /* Find free socket slot. */
198 for (slot = 0; slot < SZ(reusable_connection); slot++)
200 if (reusable_connection[slot].sfd == JB_INVALID_SOCKET)
202 assert(reusable_connection[slot].in_use == 0);
203 log_error(LOG_LEVEL_CONNECT,
204 "Remembering socket %d for %s:%d in slot %d.",
205 connection->sfd, http->host, http->port, slot);
206 free_slot_found = TRUE;
211 if (!free_slot_found)
213 log_error(LOG_LEVEL_CONNECT,
214 "No free slots found to remembering socket for %s:%d. Last slot %d.",
215 http->host, http->port, slot);
216 privoxy_mutex_unlock(&connection_reuse_mutex);
217 close_socket(connection->sfd);
221 assert(NULL != http->host);
222 reusable_connection[slot].host = strdup(http->host);
223 if (NULL == reusable_connection[slot].host)
225 log_error(LOG_LEVEL_FATAL, "Out of memory saving socket.");
227 reusable_connection[slot].sfd = connection->sfd;
228 reusable_connection[slot].port = http->port;
229 reusable_connection[slot].in_use = 0;
230 reusable_connection[slot].timestamp = connection->timestamp;
231 reusable_connection->request_sent = connection->request_sent;
232 reusable_connection->response_received = connection->response_received;
233 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 = fwd->type;
243 if (NULL != fwd->gateway_host)
245 reusable_connection[slot].gateway_host = strdup(fwd->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 = fwd->gateway_port;
257 if (NULL != fwd->forward_host)
259 reusable_connection[slot].forward_host = strdup(fwd->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 = fwd->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, "Gateway mismatch.");
393 if (( (NULL != connection->forward_host)
394 && (NULL != fwd->forward_host)
395 && strcmpic(connection->forward_host, fwd->forward_host))
396 && (connection->forward_host != fwd->forward_host))
398 log_error(LOG_LEVEL_CONNECT, "Forwarding proxy mismatch.");
402 return (!strcmpic(connection->host, http->host));
405 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
408 #ifdef FEATURE_CONNECTION_SHARING
409 /*********************************************************************
411 * Function : close_unusable_connections
413 * Description : Closes remembered connections that have timed
414 * out or have been closed on the other side.
418 * Returns : Number of connections that are still alive.
420 *********************************************************************/
421 int close_unusable_connections(void)
423 unsigned int slot = 0;
424 int connections_alive = 0;
426 privoxy_mutex_lock(&connection_reuse_mutex);
428 for (slot = 0; slot < SZ(reusable_connection); slot++)
430 if (!reusable_connection[slot].in_use
431 && (JB_INVALID_SOCKET != reusable_connection[slot].sfd))
433 time_t time_open = time(NULL) - reusable_connection[slot].timestamp;
434 time_t latency = (reusable_connection[slot].response_received -
435 reusable_connection[slot].request_sent) / 2;
437 if (reusable_connection[slot].keep_alive_timeout < time_open + latency)
439 log_error(LOG_LEVEL_CONNECT,
440 "The connection to %s:%d in slot %d timed out. "
441 "Closing socket %d. Timeout is: %d. Assumed latency: %d.",
442 reusable_connection[slot].host,
443 reusable_connection[slot].port, slot,
444 reusable_connection[slot].sfd,
445 reusable_connection[slot].keep_alive_timeout,
447 close_socket(reusable_connection[slot].sfd);
448 mark_connection_closed(&reusable_connection[slot]);
450 else if (!socket_is_still_usable(reusable_connection[slot].sfd))
452 log_error(LOG_LEVEL_CONNECT,
453 "The connection to %s:%d in slot %d is no longer usable. "
454 "Closing socket %d.", reusable_connection[slot].host,
455 reusable_connection[slot].port, slot,
456 reusable_connection[slot].sfd);
457 close_socket(reusable_connection[slot].sfd);
458 mark_connection_closed(&reusable_connection[slot]);
467 privoxy_mutex_unlock(&connection_reuse_mutex);
469 return connections_alive;
474 /*********************************************************************
476 * Function : get_reusable_connection
478 * Description : Returns an open socket to a previously remembered
479 * open connection (if there is one).
482 * 1 : http = The destination for the connection.
483 * 2 : fwd = The forwarder settings.
485 * Returns : JB_INVALID_SOCKET => No reusable connection found,
486 * otherwise a usable socket.
488 *********************************************************************/
489 static jb_socket get_reusable_connection(const struct http_request *http,
490 const struct forward_spec *fwd)
492 jb_socket sfd = JB_INVALID_SOCKET;
493 unsigned int slot = 0;
495 close_unusable_connections();
497 privoxy_mutex_lock(&connection_reuse_mutex);
499 for (slot = 0; slot < SZ(reusable_connection); slot++)
501 if (!reusable_connection[slot].in_use
502 && (JB_INVALID_SOCKET != reusable_connection[slot].sfd))
504 if (connection_destination_matches(&reusable_connection[slot], http, fwd))
506 reusable_connection[slot].in_use = TRUE;
507 sfd = reusable_connection[slot].sfd;
508 log_error(LOG_LEVEL_CONNECT,
509 "Found reusable socket %d for %s:%d in slot %d. "
510 "Timestamp made %d seconds ago. Timeout: %d. Latency: %d.",
511 sfd, reusable_connection[slot].host, reusable_connection[slot].port,
512 slot, time(NULL) - reusable_connection[slot].timestamp,
513 reusable_connection[slot].keep_alive_timeout,
514 (int)(reusable_connection[slot].response_received -
515 reusable_connection[slot].request_sent));
521 privoxy_mutex_unlock(&connection_reuse_mutex);
528 /*********************************************************************
530 * Function : mark_connection_unused
532 * Description : Gives a remembered connection free for reuse.
535 * 1 : connection = The connection in question.
537 * Returns : TRUE => Socket found and marked as unused.
538 * FALSE => Socket not found.
540 *********************************************************************/
541 static int mark_connection_unused(const struct reusable_connection *connection)
543 unsigned int slot = 0;
544 int socket_found = FALSE;
546 assert(connection->sfd != JB_INVALID_SOCKET);
548 privoxy_mutex_lock(&connection_reuse_mutex);
550 for (slot = 0; slot < SZ(reusable_connection); slot++)
552 if (reusable_connection[slot].sfd == connection->sfd)
554 assert(reusable_connection[slot].in_use);
556 log_error(LOG_LEVEL_CONNECT,
557 "Marking open socket %d for %s:%d in slot %d as unused.",
558 connection->sfd, reusable_connection[slot].host,
559 reusable_connection[slot].port, slot);
560 reusable_connection[slot].in_use = 0;
561 reusable_connection[slot].timestamp = connection->timestamp;
566 privoxy_mutex_unlock(&connection_reuse_mutex);
573 /*********************************************************************
575 * Function : set_keep_alive_timeout
577 * Description : Sets the timeout after which open
578 * connections will no longer be reused.
581 * 1 : timeout = The timeout in seconds.
585 *********************************************************************/
586 void set_keep_alive_timeout(unsigned int timeout)
588 keep_alive_timeout = timeout;
590 #endif /* def FEATURE_CONNECTION_SHARING */
593 /*********************************************************************
595 * Function : forwarded_connect
597 * Description : Connect to a specified web server, possibly via
598 * a HTTP proxy and/or a SOCKS proxy.
601 * 1 : fwd = the proxies to use when connecting.
602 * 2 : http = the http request and apropos headers
603 * 3 : csp = Current client state (buffers, headers, etc...)
605 * Returns : JB_INVALID_SOCKET => failure, else it is the socket file descriptor.
607 *********************************************************************/
608 jb_socket forwarded_connect(const struct forward_spec * fwd,
609 struct http_request *http,
610 struct client_state *csp)
612 const char * dest_host;
614 jb_socket sfd = JB_INVALID_SOCKET;
616 #ifdef FEATURE_CONNECTION_SHARING
617 if ((csp->config->feature_flags & RUNTIME_FEATURE_CONNECTION_SHARING)
618 && !(csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED))
620 sfd = get_reusable_connection(http, fwd);
621 if (JB_INVALID_SOCKET != sfd)
626 #endif /* def FEATURE_CONNECTION_SHARING */
628 /* Figure out if we need to connect to the web server or a HTTP proxy. */
629 if (fwd->forward_host)
632 dest_host = fwd->forward_host;
633 dest_port = fwd->forward_port;
638 dest_host = http->host;
639 dest_port = http->port;
642 /* Connect, maybe using a SOCKS proxy */
646 sfd = connect_to(dest_host, dest_port, csp);
650 sfd = socks4_connect(fwd, dest_host, dest_port, csp);
653 sfd = socks5_connect(fwd, dest_host, dest_port, csp);
656 /* Should never get here */
657 log_error(LOG_LEVEL_FATAL,
658 "SOCKS4 impossible internal error - bad SOCKS type.");
661 if (JB_INVALID_SOCKET != sfd)
663 log_error(LOG_LEVEL_CONNECT,
664 "Created new connection to %s:%d on socket %d.",
665 http->host, http->port, sfd);
673 /*********************************************************************
675 * Function : socks4_connect
677 * Description : Connect to the SOCKS server, and connect through
678 * it to the specified server. This handles
679 * all the SOCKS negotiation, and returns a file
680 * descriptor for a socket which can be treated as a
681 * normal (non-SOCKS) socket.
683 * Logged error messages are saved to csp->error_message
684 * and later reused by error_response() for the CGI
685 * message. strdup allocation failures are handled there.
688 * 1 : fwd = Specifies the SOCKS proxy to use.
689 * 2 : target_host = The final server to connect to.
690 * 3 : target_port = The final port to connect to.
691 * 4 : csp = Current client state (buffers, headers, etc...)
693 * Returns : JB_INVALID_SOCKET => failure, else a socket file descriptor.
695 *********************************************************************/
696 static jb_socket socks4_connect(const struct forward_spec * fwd,
697 const char * target_host,
699 struct client_state *csp)
701 unsigned long web_server_addr;
702 char buf[BUFFER_SIZE];
703 struct socks_op *c = (struct socks_op *)buf;
704 struct socks_reply *s = (struct socks_reply *)buf;
711 if ((fwd->gateway_host == NULL) || (*fwd->gateway_host == '\0'))
713 /* XXX: Shouldn't the config file parser prevent this? */
714 errstr = "NULL gateway host specified.";
718 if (fwd->gateway_port <= 0)
720 errstr = "invalid gateway port specified.";
726 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
727 csp->error_message = strdup(errstr);
729 return(JB_INVALID_SOCKET);
732 /* build a socks request for connection to the web server */
734 strlcpy(&(c->userid), socks_userid, sizeof(buf) - sizeof(struct socks_op));
736 csiz = sizeof(*c) + sizeof(socks_userid) - sizeof(c->userid) - sizeof(c->padding);
741 web_server_addr = resolve_hostname_to_ip(target_host);
742 if (web_server_addr == INADDR_NONE)
744 errstr = "could not resolve target host";
745 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s %s", errstr, target_host);
750 web_server_addr = htonl(web_server_addr);
754 web_server_addr = 0x00000001;
755 n = csiz + strlen(target_host) + 1;
759 errstr = "buffer cbuf too small.";
760 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
765 strlcpy(buf + csiz, target_host, sizeof(buf) - sizeof(struct socks_op) - csiz);
767 * What we forward to the socks4a server should have the
768 * size of socks_op, plus the length of the userid plus
769 * its \0 byte (which we don't have to add because the
770 * first byte of the userid is counted twice as it's also
771 * part of sock_op) minus the padding bytes (which are part
772 * of the userid as well), plus the length of the target_host
773 * (which is stored csiz bytes after the beginning of the buffer),
774 * plus another \0 byte.
776 assert(n == sizeof(struct socks_op) + strlen(&(c->userid)) - sizeof(c->padding) + strlen(buf + csiz) + 1);
781 /* Should never get here */
782 log_error(LOG_LEVEL_FATAL,
783 "socks4_connect: SOCKS4 impossible internal error - bad SOCKS type.");
785 return(JB_INVALID_SOCKET);
790 csp->error_message = strdup(errstr);
791 return(JB_INVALID_SOCKET);
796 c->dstport[0] = (unsigned char)((target_port >> 8 ) & 0xff);
797 c->dstport[1] = (unsigned char)((target_port ) & 0xff);
798 c->dstip[0] = (unsigned char)((web_server_addr >> 24 ) & 0xff);
799 c->dstip[1] = (unsigned char)((web_server_addr >> 16 ) & 0xff);
800 c->dstip[2] = (unsigned char)((web_server_addr >> 8 ) & 0xff);
801 c->dstip[3] = (unsigned char)((web_server_addr ) & 0xff);
803 /* pass the request to the socks server */
804 sfd = connect_to(fwd->gateway_host, fwd->gateway_port, csp);
806 if (sfd == JB_INVALID_SOCKET)
809 * XXX: connect_to should fill in the exact reason.
810 * Most likely resolving the IP of the forwarder failed.
812 errstr = "connect_to failed: see logfile for details";
815 else if (write_socket(sfd, (char *)c, csiz))
817 errstr = "SOCKS4 negotiation write failed.";
818 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
822 else if (read_socket(sfd, buf, sizeof(buf)) != sizeof(*s))
824 errstr = "SOCKS4 negotiation read failed.";
825 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
832 csp->error_message = strdup(errstr);
833 return(JB_INVALID_SOCKET);
838 case SOCKS_REQUEST_GRANTED:
840 case SOCKS_REQUEST_REJECT:
841 errstr = "SOCKS request rejected or failed.";
844 case SOCKS_REQUEST_IDENT_FAILED:
845 errstr = "SOCKS request rejected because "
846 "SOCKS server cannot connect to identd on the client.";
849 case SOCKS_REQUEST_IDENT_CONFLICT:
850 errstr = "SOCKS request rejected because "
851 "the client program and identd report "
852 "different user-ids.";
857 snprintf(buf, sizeof(buf),
858 "SOCKS request rejected for reason code %d.", s->cd);
862 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
863 csp->error_message = strdup(errstr);
866 return(JB_INVALID_SOCKET);
870 /*********************************************************************
872 * Function : translate_socks5_error
874 * Description : Translates a SOCKS errors to a string.
877 * 1 : socks_error = The error code to translate.
879 * Returns : The string translation.
881 *********************************************************************/
882 static const char *translate_socks5_error(int socks_error)
886 /* XXX: these should be more descriptive */
887 case SOCKS5_REQUEST_FAILED:
888 return "SOCKS5 request failed";
889 case SOCKS5_REQUEST_DENIED:
890 return "SOCKS5 request denied";
891 case SOCKS5_REQUEST_NETWORK_UNREACHABLE:
892 return "SOCKS5 network unreachable";
893 case SOCKS5_REQUEST_HOST_UNREACHABLE:
894 return "SOCKS5 host unreachable";
895 case SOCKS5_REQUEST_CONNECTION_REFUSED:
896 return "SOCKS5 connection refused";
897 case SOCKS5_REQUEST_TTL_EXPIRED:
898 return "SOCKS5 TTL expired";
899 case SOCKS5_REQUEST_PROTOCOL_ERROR:
900 return "SOCKS5 client protocol error";
901 case SOCKS5_REQUEST_BAD_ADDRESS_TYPE:
902 return "SOCKS5 domain names unsupported";
903 case SOCKS5_REQUEST_GRANTED:
904 return "everything's peachy";
906 return "SOCKS5 negotiation protocol error";
910 /*********************************************************************
912 * Function : socks5_connect
914 * Description : Connect to the SOCKS server, and connect through
915 * it to the specified server. This handles
916 * all the SOCKS negotiation, and returns a file
917 * descriptor for a socket which can be treated as a
918 * normal (non-SOCKS) socket.
921 * 1 : fwd = Specifies the SOCKS proxy to use.
922 * 2 : target_host = The final server to connect to.
923 * 3 : target_port = The final port to connect to.
924 * 4 : csp = Current client state (buffers, headers, etc...)
926 * Returns : JB_INVALID_SOCKET => failure, else a socket file descriptor.
928 *********************************************************************/
929 static jb_socket socks5_connect(const struct forward_spec *fwd,
930 const char *target_host,
932 struct client_state *csp)
937 size_t client_pos = 0;
941 const char *errstr = NULL;
943 assert(fwd->gateway_host);
944 if ((fwd->gateway_host == NULL) || (*fwd->gateway_host == '\0'))
946 errstr = "NULL gateway host specified";
950 if (fwd->gateway_port <= 0)
953 * XXX: currently this can't happen because in
954 * case of invalid gateway ports we use the defaults.
955 * Of course we really shouldn't do that.
957 errstr = "invalid gateway port specified";
961 hostlen = strlen(target_host);
962 if (hostlen > (size_t)255)
964 errstr = "target host name is longer than 255 characters";
968 if (fwd->type != SOCKS_5)
970 /* Should never get here */
971 log_error(LOG_LEVEL_FATAL,
972 "SOCKS5 impossible internal error - bad SOCKS type");
979 assert(errstr != NULL);
980 log_error(LOG_LEVEL_CONNECT, "socks5_connect: %s", errstr);
981 csp->error_message = strdup(errstr);
982 return(JB_INVALID_SOCKET);
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)
990 errstr = "socks5 server unreachable";
991 log_error(LOG_LEVEL_CONNECT, "socks5_connect: %s", errstr);
992 csp->error_message = strdup(errstr);
993 return(JB_INVALID_SOCKET);
997 cbuf[client_pos++] = '\x05'; /* Version */
998 cbuf[client_pos++] = '\x01'; /* One authentication method supported */
999 cbuf[client_pos++] = '\x00'; /* The no authentication authentication method */
1001 if (write_socket(sfd, cbuf, client_pos))
1003 errstr = "SOCKS5 negotiation write failed";
1004 csp->error_message = strdup(errstr);
1005 log_error(LOG_LEVEL_CONNECT, "%s", errstr);
1007 return(JB_INVALID_SOCKET);
1010 if (read_socket(sfd, sbuf, sizeof(sbuf)) != 2)
1012 errstr = "SOCKS5 negotiation read failed";
1016 if (!err && (sbuf[0] != '\x05'))
1018 errstr = "SOCKS5 negotiation protocol version error";
1022 if (!err && (sbuf[1] == '\xff'))
1024 errstr = "SOCKS5 authentication required";
1028 if (!err && (sbuf[1] != '\x00'))
1030 errstr = "SOCKS5 negotiation protocol error";
1036 assert(errstr != NULL);
1037 log_error(LOG_LEVEL_CONNECT, "socks5_connect: %s", errstr);
1038 csp->error_message = strdup(errstr);
1041 return(JB_INVALID_SOCKET);
1045 cbuf[client_pos++] = '\x05'; /* Version */
1046 cbuf[client_pos++] = '\x01'; /* TCP connect */
1047 cbuf[client_pos++] = '\x00'; /* Reserved, must be 0x00 */
1048 cbuf[client_pos++] = '\x03'; /* Address is domain name */
1049 cbuf[client_pos++] = (char)(hostlen & 0xffu);
1050 assert(sizeof(cbuf) - client_pos > (size_t)255);
1051 /* Using strncpy because we really want the nul byte padding. */
1052 strncpy(cbuf + client_pos, target_host, sizeof(cbuf) - client_pos);
1053 client_pos += (hostlen & 0xffu);
1054 cbuf[client_pos++] = (char)((target_port >> 8) & 0xff);
1055 cbuf[client_pos++] = (char)((target_port ) & 0xff);
1057 if (write_socket(sfd, cbuf, client_pos))
1059 errstr = "SOCKS5 negotiation read failed";
1060 csp->error_message = strdup(errstr);
1061 log_error(LOG_LEVEL_CONNECT, "%s", errstr);
1064 return(JB_INVALID_SOCKET);
1067 server_size = read_socket(sfd, sbuf, sizeof(sbuf));
1068 if (server_size < 3)
1070 errstr = "SOCKS5 negotiation read failed";
1073 else if (server_size > 20)
1075 /* This is somewhat unexpected but doesn't realy matter. */
1076 log_error(LOG_LEVEL_CONNECT, "socks5_connect: read %d bytes "
1077 "from socks server. Would have accepted up to %d.",
1078 server_size, sizeof(sbuf));
1081 if (!err && (sbuf[0] != '\x05'))
1083 errstr = "SOCKS5 negotiation protocol version error";
1087 if (!err && (sbuf[2] != '\x00'))
1089 errstr = "SOCKS5 negotiation protocol error";
1095 if (sbuf[1] == SOCKS5_REQUEST_GRANTED)
1099 errstr = translate_socks5_error(sbuf[1]);
1102 assert(errstr != NULL);
1103 csp->error_message = strdup(errstr);
1104 log_error(LOG_LEVEL_CONNECT, "socks5_connect: %s", errstr);
1108 return(JB_INVALID_SOCKET);