1 const char gateway_rcs[] = "$Id: gateway.c,v 1.103 2017/07/01 18:34:07 ler762 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) 2001-2017 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
138 static struct reusable_connection reusable_connection[MAX_REUSABLE_CONNECTIONS];
139 static int mark_connection_unused(const struct reusable_connection *connection);
141 /*********************************************************************
143 * Function : initialize_reusable_connections
145 * Description : Initializes the reusable_connection structures.
146 * Must be called with connection_reuse_mutex locked.
152 *********************************************************************/
153 extern void initialize_reusable_connections(void)
155 unsigned int slot = 0;
157 #if !defined(HAVE_POLL) && !defined(_WIN32)
158 log_error(LOG_LEVEL_INFO,
159 "Detecting already dead connections might not work "
160 "correctly on your platform. In case of problems, "
161 "unset the keep-alive-timeout option.");
164 for (slot = 0; slot < SZ(reusable_connection); slot++)
166 mark_connection_closed(&reusable_connection[slot]);
169 log_error(LOG_LEVEL_CONNECT, "Initialized %d socket slots.", slot);
173 /*********************************************************************
175 * Function : remember_connection
177 * Description : Remembers a server connection for reuse later on.
180 * 1 : connection = The server connection to remember.
184 *********************************************************************/
185 void remember_connection(const struct reusable_connection *connection)
187 unsigned int slot = 0;
188 int free_slot_found = FALSE;
190 assert(NULL != connection);
191 assert(connection->sfd != JB_INVALID_SOCKET);
193 if (mark_connection_unused(connection))
198 privoxy_mutex_lock(&connection_reuse_mutex);
200 /* Find free socket slot. */
201 for (slot = 0; slot < SZ(reusable_connection); slot++)
203 if (reusable_connection[slot].sfd == JB_INVALID_SOCKET)
205 assert(reusable_connection[slot].in_use == 0);
206 log_error(LOG_LEVEL_CONNECT,
207 "Remembering socket %d for %s:%d in slot %d.",
208 connection->sfd, connection->host, connection->port, slot);
209 free_slot_found = TRUE;
214 if (!free_slot_found)
216 log_error(LOG_LEVEL_CONNECT,
217 "No free slots found to remember socket for %s:%d. Last slot %d.",
218 connection->host, connection->port, slot);
219 privoxy_mutex_unlock(&connection_reuse_mutex);
220 close_socket(connection->sfd);
224 assert(NULL != connection->host);
225 reusable_connection[slot].host = strdup_or_die(connection->host);
226 reusable_connection[slot].sfd = connection->sfd;
227 reusable_connection[slot].port = connection->port;
228 reusable_connection[slot].in_use = 0;
229 reusable_connection[slot].timestamp = connection->timestamp;
230 reusable_connection[slot].request_sent = connection->request_sent;
231 reusable_connection[slot].response_received = connection->response_received;
232 reusable_connection[slot].keep_alive_timeout = connection->keep_alive_timeout;
233 reusable_connection[slot].requests_sent_total = connection->requests_sent_total;
235 assert(reusable_connection[slot].gateway_host == NULL);
236 assert(reusable_connection[slot].gateway_port == 0);
237 assert(reusable_connection[slot].forwarder_type == SOCKS_NONE);
238 assert(reusable_connection[slot].forward_host == NULL);
239 assert(reusable_connection[slot].forward_port == 0);
241 reusable_connection[slot].forwarder_type = connection->forwarder_type;
242 if (NULL != connection->gateway_host)
244 reusable_connection[slot].gateway_host = strdup_or_die(connection->gateway_host);
248 reusable_connection[slot].gateway_host = NULL;
250 reusable_connection[slot].gateway_port = connection->gateway_port;
252 if (NULL != connection->forward_host)
254 reusable_connection[slot].forward_host = strdup_or_die(connection->forward_host);
258 reusable_connection[slot].forward_host = NULL;
260 reusable_connection[slot].forward_port = connection->forward_port;
262 privoxy_mutex_unlock(&connection_reuse_mutex);
264 #endif /* def FEATURE_CONNECTION_SHARING */
267 /*********************************************************************
269 * Function : mark_connection_closed
271 * Description : Marks a reused connection closed.
274 * 1 : closed_connection = The connection to mark as closed.
278 *********************************************************************/
279 void mark_connection_closed(struct reusable_connection *closed_connection)
281 closed_connection->in_use = FALSE;
282 closed_connection->sfd = JB_INVALID_SOCKET;
283 freez(closed_connection->host);
284 closed_connection->port = 0;
285 closed_connection->timestamp = 0;
286 closed_connection->request_sent = 0;
287 closed_connection->response_received = 0;
288 closed_connection->keep_alive_timeout = 0;
289 closed_connection->requests_sent_total = 0;
290 closed_connection->forwarder_type = SOCKS_NONE;
291 freez(closed_connection->gateway_host);
292 closed_connection->gateway_port = 0;
293 freez(closed_connection->forward_host);
294 closed_connection->forward_port = 0;
298 #ifdef FEATURE_CONNECTION_SHARING
299 /*********************************************************************
301 * Function : forget_connection
303 * Description : Removes a previously remembered connection from
304 * the list of reusable connections.
307 * 1 : sfd = The socket belonging to the connection in question.
311 *********************************************************************/
312 void forget_connection(jb_socket sfd)
314 unsigned int slot = 0;
316 assert(sfd != JB_INVALID_SOCKET);
318 privoxy_mutex_lock(&connection_reuse_mutex);
320 for (slot = 0; slot < SZ(reusable_connection); slot++)
322 if (reusable_connection[slot].sfd == sfd)
324 assert(reusable_connection[slot].in_use);
326 log_error(LOG_LEVEL_CONNECT,
327 "Forgetting socket %d for %s:%d in slot %d.",
328 sfd, reusable_connection[slot].host,
329 reusable_connection[slot].port, slot);
330 mark_connection_closed(&reusable_connection[slot]);
335 privoxy_mutex_unlock(&connection_reuse_mutex);
338 #endif /* def FEATURE_CONNECTION_SHARING */
341 #ifdef FEATURE_CONNECTION_KEEP_ALIVE
342 /*********************************************************************
344 * Function : connection_destination_matches
346 * Description : Determines whether a remembered connection can
347 * be reused. That is, whether the destination and
348 * the forwarding settings match.
351 * 1 : connection = The connection to check.
352 * 2 : http = The destination for the connection.
353 * 3 : fwd = The forwarder settings.
355 * Returns : TRUE for yes, FALSE otherwise.
357 *********************************************************************/
358 int connection_destination_matches(const struct reusable_connection *connection,
359 const struct http_request *http,
360 const struct forward_spec *fwd)
362 if ((connection->forwarder_type != fwd->type)
363 || (connection->gateway_port != fwd->gateway_port)
364 || (connection->forward_port != fwd->forward_port)
365 || (connection->port != http->port))
370 if (( (NULL != connection->gateway_host)
371 && (NULL != fwd->gateway_host)
372 && strcmpic(connection->gateway_host, fwd->gateway_host))
373 && (connection->gateway_host != fwd->gateway_host))
375 log_error(LOG_LEVEL_CONNECT,
376 "Gateway mismatch. Previous gateway: %s. Current gateway: %s",
377 connection->gateway_host, fwd->gateway_host);
381 if (( (NULL != connection->forward_host)
382 && (NULL != fwd->forward_host)
383 && strcmpic(connection->forward_host, fwd->forward_host))
384 && (connection->forward_host != fwd->forward_host))
386 log_error(LOG_LEVEL_CONNECT,
387 "Forwarding proxy mismatch. Previous proxy: %s. Current proxy: %s",
388 connection->forward_host, fwd->forward_host);
392 return (!strcmpic(connection->host, http->host));
395 #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
398 #ifdef FEATURE_CONNECTION_SHARING
399 /*********************************************************************
401 * Function : close_unusable_connections
403 * Description : Closes remembered connections that have timed
404 * out or have been closed on the other side.
408 * Returns : Number of connections that are still alive.
410 *********************************************************************/
411 int close_unusable_connections(void)
413 unsigned int slot = 0;
414 int connections_alive = 0;
416 privoxy_mutex_lock(&connection_reuse_mutex);
418 for (slot = 0; slot < SZ(reusable_connection); slot++)
420 if (!reusable_connection[slot].in_use
421 && (JB_INVALID_SOCKET != reusable_connection[slot].sfd))
423 time_t time_open = time(NULL) - reusable_connection[slot].timestamp;
424 time_t latency = (reusable_connection[slot].response_received -
425 reusable_connection[slot].request_sent) / 2;
427 if (reusable_connection[slot].keep_alive_timeout < time_open + latency)
429 log_error(LOG_LEVEL_CONNECT,
430 "The connection to %s:%d in slot %d timed out. "
431 "Closing socket %d. Timeout is: %d. Assumed latency: %d.",
432 reusable_connection[slot].host,
433 reusable_connection[slot].port, slot,
434 reusable_connection[slot].sfd,
435 reusable_connection[slot].keep_alive_timeout,
437 close_socket(reusable_connection[slot].sfd);
438 mark_connection_closed(&reusable_connection[slot]);
440 else if (!socket_is_still_alive(reusable_connection[slot].sfd))
442 log_error(LOG_LEVEL_CONNECT,
443 "The connection to %s:%d in slot %d is no longer usable. "
444 "Closing socket %d.", reusable_connection[slot].host,
445 reusable_connection[slot].port, slot,
446 reusable_connection[slot].sfd);
447 close_socket(reusable_connection[slot].sfd);
448 mark_connection_closed(&reusable_connection[slot]);
457 privoxy_mutex_unlock(&connection_reuse_mutex);
459 return connections_alive;
464 /*********************************************************************
466 * Function : get_reusable_connection
468 * Description : Returns an open socket to a previously remembered
469 * open connection (if there is one).
472 * 1 : http = The destination for the connection.
473 * 2 : fwd = The forwarder settings.
475 * Returns : JB_INVALID_SOCKET => No reusable connection found,
476 * otherwise a usable socket.
478 *********************************************************************/
479 static jb_socket get_reusable_connection(const struct http_request *http,
480 const struct forward_spec *fwd)
482 jb_socket sfd = JB_INVALID_SOCKET;
483 unsigned int slot = 0;
485 close_unusable_connections();
487 privoxy_mutex_lock(&connection_reuse_mutex);
489 for (slot = 0; slot < SZ(reusable_connection); slot++)
491 if (!reusable_connection[slot].in_use
492 && (JB_INVALID_SOCKET != reusable_connection[slot].sfd))
494 if (connection_destination_matches(&reusable_connection[slot], http, fwd))
496 reusable_connection[slot].in_use = TRUE;
497 sfd = reusable_connection[slot].sfd;
498 log_error(LOG_LEVEL_CONNECT,
499 "Found reusable socket %d for %s:%d in slot %d. Timestamp made %d "
500 "seconds ago. Timeout: %d. Latency: %d. Requests served: %d",
501 sfd, reusable_connection[slot].host, reusable_connection[slot].port,
502 slot, time(NULL) - reusable_connection[slot].timestamp,
503 reusable_connection[slot].keep_alive_timeout,
504 (int)(reusable_connection[slot].response_received -
505 reusable_connection[slot].request_sent),
506 reusable_connection[slot].requests_sent_total);
512 privoxy_mutex_unlock(&connection_reuse_mutex);
519 /*********************************************************************
521 * Function : mark_connection_unused
523 * Description : Gives a remembered connection free for reuse.
526 * 1 : connection = The connection in question.
528 * Returns : TRUE => Socket found and marked as unused.
529 * FALSE => Socket not found.
531 *********************************************************************/
532 static int mark_connection_unused(const struct reusable_connection *connection)
534 unsigned int slot = 0;
535 int socket_found = FALSE;
537 assert(connection->sfd != JB_INVALID_SOCKET);
539 privoxy_mutex_lock(&connection_reuse_mutex);
541 for (slot = 0; slot < SZ(reusable_connection); slot++)
543 if (reusable_connection[slot].sfd == connection->sfd)
545 assert(reusable_connection[slot].in_use);
547 log_error(LOG_LEVEL_CONNECT,
548 "Marking open socket %d for %s:%d in slot %d as unused.",
549 connection->sfd, reusable_connection[slot].host,
550 reusable_connection[slot].port, slot);
551 reusable_connection[slot].in_use = 0;
552 reusable_connection[slot].timestamp = connection->timestamp;
557 privoxy_mutex_unlock(&connection_reuse_mutex);
562 #endif /* def FEATURE_CONNECTION_SHARING */
565 /*********************************************************************
567 * Function : forwarded_connect
569 * Description : Connect to a specified web server, possibly via
570 * a HTTP proxy and/or a SOCKS proxy.
573 * 1 : fwd = the proxies to use when connecting.
574 * 2 : http = the http request and apropos headers
575 * 3 : csp = Current client state (buffers, headers, etc...)
577 * Returns : JB_INVALID_SOCKET => failure, else it is the socket file descriptor.
579 *********************************************************************/
580 jb_socket forwarded_connect(const struct forward_spec * fwd,
581 struct http_request *http,
582 struct client_state *csp)
584 const char * dest_host;
586 jb_socket sfd = JB_INVALID_SOCKET;
588 #ifdef FEATURE_CONNECTION_SHARING
589 if ((csp->config->feature_flags & RUNTIME_FEATURE_CONNECTION_SHARING)
590 && !(csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED))
592 sfd = get_reusable_connection(http, fwd);
593 if (JB_INVALID_SOCKET != sfd)
598 #endif /* def FEATURE_CONNECTION_SHARING */
600 /* Figure out if we need to connect to the web server or a HTTP proxy. */
601 if (fwd->forward_host)
604 dest_host = fwd->forward_host;
605 dest_port = fwd->forward_port;
610 dest_host = http->host;
611 dest_port = http->port;
614 /* Connect, maybe using a SOCKS proxy */
618 case FORWARD_WEBSERVER:
619 sfd = connect_to(dest_host, dest_port, csp);
623 sfd = socks4_connect(fwd, dest_host, dest_port, csp);
627 sfd = socks5_connect(fwd, dest_host, dest_port, csp);
630 /* Should never get here */
631 log_error(LOG_LEVEL_FATAL,
632 "Internal error in forwarded_connect(). Bad proxy type: %d", fwd->type);
635 if (JB_INVALID_SOCKET != sfd)
637 log_error(LOG_LEVEL_CONNECT,
638 "Created new connection to %s:%d on socket %d.",
639 http->host, http->port, sfd);
648 /*********************************************************************
650 * Function : socks_fuzz
652 * Description : Wrapper around socks[45]_connect() used for fuzzing.
655 * 1 : csp = Current client state (buffers, headers, etc...)
657 * Returns : JB_ERR_OK or JB_ERR_PARSE
659 *********************************************************************/
660 extern jb_err socks_fuzz(struct client_state *csp)
663 static struct forward_spec fwd;
664 char target_host[] = "fuzz.example.org";
665 int target_port = 12345;
667 fwd.gateway_host = strdup_or_die("fuzz.example.org");
668 fwd.gateway_port = 12345;
671 socket = socks4_connect(&fwd, target_host, target_port, csp);
673 if (JB_INVALID_SOCKET != socket)
676 socket = socks5_connect(&fwd, target_host, target_port, csp);
679 if (JB_INVALID_SOCKET == socket)
681 log_error(LOG_LEVEL_ERROR, "%s", csp->error_message);
685 log_error(LOG_LEVEL_INFO, "Input looks like an acceptable socks response");
692 /*********************************************************************
694 * Function : socks4_connect
696 * Description : Connect to the SOCKS server, and connect through
697 * it to the specified server. This handles
698 * all the SOCKS negotiation, and returns a file
699 * descriptor for a socket which can be treated as a
700 * normal (non-SOCKS) socket.
702 * Logged error messages are saved to csp->error_message
703 * and later reused by error_response() for the CGI
704 * message. strdup allocation failures are handled there.
707 * 1 : fwd = Specifies the SOCKS proxy to use.
708 * 2 : target_host = The final server to connect to.
709 * 3 : target_port = The final port to connect to.
710 * 4 : csp = Current client state (buffers, headers, etc...)
712 * Returns : JB_INVALID_SOCKET => failure, else a socket file descriptor.
714 *********************************************************************/
715 static jb_socket socks4_connect(const struct forward_spec * fwd,
716 const char * target_host,
718 struct client_state *csp)
720 unsigned long web_server_addr;
721 char buf[BUFFER_SIZE];
722 struct socks_op *c = (struct socks_op *)buf;
723 struct socks_reply *s = (struct socks_reply *)buf;
730 if ((fwd->gateway_host == NULL) || (*fwd->gateway_host == '\0'))
732 /* XXX: Shouldn't the config file parser prevent this? */
733 errstr = "NULL gateway host specified.";
737 if (fwd->gateway_port <= 0)
739 errstr = "invalid gateway port specified.";
745 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
746 csp->error_message = strdup(errstr);
748 return(JB_INVALID_SOCKET);
751 /* build a socks request for connection to the web server */
753 strlcpy(&(c->userid), socks_userid, sizeof(buf) - sizeof(struct socks_op));
755 csiz = sizeof(*c) + sizeof(socks_userid) - sizeof(c->userid) - sizeof(c->padding);
760 web_server_addr = resolve_hostname_to_ip(target_host);
761 if (web_server_addr == INADDR_NONE)
763 errstr = "could not resolve target host";
764 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s %s", errstr, target_host);
769 web_server_addr = htonl(web_server_addr);
773 web_server_addr = 0x00000001;
774 n = csiz + strlen(target_host) + 1;
778 errstr = "buffer cbuf too small.";
779 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
784 strlcpy(buf + csiz, target_host, sizeof(buf) - sizeof(struct socks_op) - csiz);
786 * What we forward to the socks4a server should have the
787 * size of socks_op, plus the length of the userid plus
788 * its \0 byte (which we don't have to add because the
789 * first byte of the userid is counted twice as it's also
790 * part of sock_op) minus the padding bytes (which are part
791 * of the userid as well), plus the length of the target_host
792 * (which is stored csiz bytes after the beginning of the buffer),
793 * plus another \0 byte.
795 assert(n == sizeof(struct socks_op) + strlen(&(c->userid)) - sizeof(c->padding) + strlen(buf + csiz) + 1);
800 /* Should never get here */
801 log_error(LOG_LEVEL_FATAL,
802 "socks4_connect: SOCKS4 impossible internal error - bad SOCKS type.");
804 return(JB_INVALID_SOCKET);
809 csp->error_message = strdup(errstr);
810 return(JB_INVALID_SOCKET);
815 c->dstport[0] = (unsigned char)((target_port >> 8 ) & 0xff);
816 c->dstport[1] = (unsigned char)((target_port ) & 0xff);
817 c->dstip[0] = (unsigned char)((web_server_addr >> 24) & 0xff);
818 c->dstip[1] = (unsigned char)((web_server_addr >> 16) & 0xff);
819 c->dstip[2] = (unsigned char)((web_server_addr >> 8) & 0xff);
820 c->dstip[3] = (unsigned char)((web_server_addr ) & 0xff);
825 /* pass the request to the socks server */
826 sfd = connect_to(fwd->gateway_host, fwd->gateway_port, csp);
828 if (sfd == JB_INVALID_SOCKET)
830 /* The error an its reason have already been logged by connect_to() */
831 return(JB_INVALID_SOCKET);
833 else if (write_socket(sfd, (char *)c, csiz))
835 errstr = "SOCKS4 negotiation write failed.";
836 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
840 else if (!data_is_available(sfd, csp->config->socket_timeout))
842 if (socket_is_still_alive(sfd))
844 errstr = "SOCKS4 negotiation timed out";
848 errstr = "SOCKS4 negotiation got aborted by the server";
850 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
856 if (read_socket(sfd, buf, sizeof(buf)) != sizeof(*s))
858 errstr = "SOCKS4 negotiation read failed.";
859 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
866 csp->error_message = strdup(errstr);
867 return(JB_INVALID_SOCKET);
872 case SOCKS4_REQUEST_GRANTED:
874 case SOCKS4_REQUEST_REJECT:
875 errstr = "SOCKS request rejected or failed.";
878 case SOCKS4_REQUEST_IDENT_FAILED:
879 errstr = "SOCKS request rejected because "
880 "SOCKS server cannot connect to identd on the client.";
883 case SOCKS4_REQUEST_IDENT_CONFLICT:
884 errstr = "SOCKS request rejected because "
885 "the client program and identd report "
886 "different user-ids.";
891 snprintf(buf, sizeof(buf),
892 "SOCKS request rejected for reason code %d.", s->cd);
896 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
897 csp->error_message = strdup(errstr);
900 return(JB_INVALID_SOCKET);
904 /*********************************************************************
906 * Function : translate_socks5_error
908 * Description : Translates a SOCKS errors to a string.
911 * 1 : socks_error = The error code to translate.
913 * Returns : The string translation.
915 *********************************************************************/
916 static const char *translate_socks5_error(int socks_error)
920 /* XXX: these should be more descriptive */
921 case SOCKS5_REQUEST_FAILED:
922 return "SOCKS5 request failed";
923 case SOCKS5_REQUEST_DENIED:
924 return "SOCKS5 request denied";
925 case SOCKS5_REQUEST_NETWORK_UNREACHABLE:
926 return "SOCKS5 network unreachable";
927 case SOCKS5_REQUEST_HOST_UNREACHABLE:
928 return "SOCKS5 destination host unreachable";
929 case SOCKS5_REQUEST_CONNECTION_REFUSED:
930 return "SOCKS5 connection refused";
931 case SOCKS5_REQUEST_TTL_EXPIRED:
932 return "SOCKS5 TTL expired";
933 case SOCKS5_REQUEST_PROTOCOL_ERROR:
934 return "SOCKS5 client protocol error";
935 case SOCKS5_REQUEST_BAD_ADDRESS_TYPE:
936 return "SOCKS5 domain names unsupported";
937 case SOCKS5_REQUEST_GRANTED:
938 return "everything's peachy";
940 return "SOCKS5 negotiation protocol error";
945 /*********************************************************************
947 * Function : socks5_connect
949 * Description : Connect to the SOCKS server, and connect through
950 * it to the specified server. This handles
951 * all the SOCKS negotiation, and returns a file
952 * descriptor for a socket which can be treated as a
953 * normal (non-SOCKS) socket.
956 * 1 : fwd = Specifies the SOCKS proxy to use.
957 * 2 : target_host = The final server to connect to.
958 * 3 : target_port = The final port to connect to.
959 * 4 : csp = Current client state (buffers, headers, etc...)
961 * Returns : JB_INVALID_SOCKET => failure, else a socket file descriptor.
963 *********************************************************************/
964 static jb_socket socks5_connect(const struct forward_spec *fwd,
965 const char *target_host,
967 struct client_state *csp)
969 #define SIZE_SOCKS5_REPLY_IPV4 10
970 #define SIZE_SOCKS5_REPLY_IPV6 22
971 #define SOCKS5_REPLY_DIFFERENCE (SIZE_SOCKS5_REPLY_IPV6 - SIZE_SOCKS5_REPLY_IPV4)
974 char sbuf[SIZE_SOCKS5_REPLY_IPV6];
975 size_t client_pos = 0;
979 const char *errstr = NULL;
981 assert(fwd->gateway_host);
982 if ((fwd->gateway_host == NULL) || (*fwd->gateway_host == '\0'))
984 errstr = "NULL gateway host specified";
988 if (fwd->gateway_port <= 0)
991 * XXX: currently this can't happen because in
992 * case of invalid gateway ports we use the defaults.
993 * Of course we really shouldn't do that.
995 errstr = "invalid gateway port specified";
999 hostlen = strlen(target_host);
1000 if (hostlen > (size_t)255)
1002 errstr = "target host name is longer than 255 characters";
1006 if ((fwd->type != SOCKS_5) && (fwd->type != SOCKS_5T))
1008 /* Should never get here */
1009 log_error(LOG_LEVEL_FATAL,
1010 "SOCKS5 impossible internal error - bad SOCKS type");
1017 assert(errstr != NULL);
1018 log_error(LOG_LEVEL_CONNECT, "socks5_connect: %s", errstr);
1019 csp->error_message = strdup(errstr);
1020 return(JB_INVALID_SOCKET);
1025 if (!err && read_socket(sfd, sbuf, 2) != 2)
1027 /* pass the request to the socks server */
1028 sfd = connect_to(fwd->gateway_host, fwd->gateway_port, csp);
1030 if (sfd == JB_INVALID_SOCKET)
1032 errstr = "socks5 server unreachable";
1033 log_error(LOG_LEVEL_CONNECT, "socks5_connect: %s", errstr);
1034 /* Free the generic error message provided by connect_to() */
1035 freez(csp->error_message);
1036 csp->error_message = strdup(errstr);
1037 return(JB_INVALID_SOCKET);
1041 cbuf[client_pos++] = '\x05'; /* Version */
1042 cbuf[client_pos++] = '\x01'; /* One authentication method supported */
1043 cbuf[client_pos++] = '\x00'; /* The no authentication authentication method */
1045 if (write_socket(sfd, cbuf, client_pos))
1047 errstr = "SOCKS5 negotiation write failed";
1048 csp->error_message = strdup(errstr);
1049 log_error(LOG_LEVEL_CONNECT, "%s", errstr);
1051 return(JB_INVALID_SOCKET);
1053 if (!data_is_available(sfd, csp->config->socket_timeout))
1055 if (socket_is_still_alive(sfd))
1057 errstr = "SOCKS5 negotiation timed out";
1061 errstr = "SOCKS5 negotiation got aborted by the server";
1066 if (!err && read_socket(sfd, sbuf, sizeof(sbuf)) != 2)
1069 errstr = "SOCKS5 negotiation read failed";
1073 if (!err && (sbuf[0] != '\x05'))
1075 errstr = "SOCKS5 negotiation protocol version error";
1079 if (!err && (sbuf[1] == '\xff'))
1081 errstr = "SOCKS5 authentication required";
1085 if (!err && (sbuf[1] != '\x00'))
1087 errstr = "SOCKS5 negotiation protocol error";
1093 assert(errstr != NULL);
1094 log_error(LOG_LEVEL_CONNECT, "socks5_connect: %s", errstr);
1095 csp->error_message = strdup(errstr);
1098 return(JB_INVALID_SOCKET);
1102 cbuf[client_pos++] = '\x05'; /* Version */
1103 cbuf[client_pos++] = '\x01'; /* TCP connect */
1104 cbuf[client_pos++] = '\x00'; /* Reserved, must be 0x00 */
1105 cbuf[client_pos++] = '\x03'; /* Address is domain name */
1106 cbuf[client_pos++] = (char)(hostlen & 0xffu);
1107 assert(sizeof(cbuf) - client_pos > (size_t)255);
1108 /* Using strncpy because we really want the nul byte padding. */
1109 strncpy(cbuf + client_pos, target_host, sizeof(cbuf) - client_pos);
1110 client_pos += (hostlen & 0xffu);
1111 cbuf[client_pos++] = (char)((target_port >> 8) & 0xff);
1112 cbuf[client_pos++] = (char)((target_port ) & 0xff);
1115 if (write_socket(sfd, cbuf, client_pos))
1117 errstr = "SOCKS5 negotiation write failed";
1118 csp->error_message = strdup(errstr);
1119 log_error(LOG_LEVEL_CONNECT, "%s", errstr);
1122 return(JB_INVALID_SOCKET);
1126 * Optimistically send the HTTP request with the initial
1127 * SOCKS request if the user enabled the use of Tor extensions,
1128 * the CONNECT method isn't being used (in which case the client
1129 * doesn't send data until it gets our 200 response) and the
1130 * client request has actually been completely read already.
1132 if ((fwd->type == SOCKS_5T) && (csp->http->ssl == 0)
1133 && (csp->flags & CSP_FLAG_CLIENT_REQUEST_COMPLETELY_READ))
1135 char *client_headers = list_to_text(csp->headers);
1136 size_t header_length;
1138 if (client_headers == NULL)
1140 log_error(LOG_LEVEL_FATAL, "Out of memory rebuilding client headers");
1142 list_remove_all(csp->headers);
1143 header_length= strlen(client_headers);
1145 log_error(LOG_LEVEL_CONNECT,
1146 "Optimistically sending %d bytes of client headers intended for %s",
1147 header_length, csp->http->hostport);
1149 if (write_socket(sfd, client_headers, header_length))
1151 log_error(LOG_LEVEL_CONNECT,
1152 "optimistically writing header to: %s failed: %E", csp->http->hostport);
1153 freez(client_headers);
1154 return(JB_INVALID_SOCKET);
1156 freez(client_headers);
1157 if (csp->expected_client_content_length != 0)
1159 unsigned long long buffered_request_bytes =
1160 (unsigned long long)(csp->client_iob->eod - csp->client_iob->cur);
1161 log_error(LOG_LEVEL_CONNECT,
1162 "Optimistically sending %llu bytes of client body. Expected %llu",
1163 csp->expected_client_content_length, buffered_request_bytes);
1164 assert(csp->expected_client_content_length == buffered_request_bytes);
1165 if (write_socket(sfd, csp->client_iob->cur, buffered_request_bytes))
1167 log_error(LOG_LEVEL_CONNECT,
1168 "optimistically writing %llu bytes of client body to: %s failed: %E",
1169 buffered_request_bytes, csp->http->hostport);
1170 return(JB_INVALID_SOCKET);
1172 clear_iob(csp->client_iob);
1177 server_size = read_socket(sfd, sbuf, SIZE_SOCKS5_REPLY_IPV4);
1178 if (server_size != SIZE_SOCKS5_REPLY_IPV4)
1180 errstr = "SOCKS5 negotiation read failed";
1184 if (sbuf[0] != '\x05')
1186 errstr = "SOCKS5 negotiation protocol version error";
1188 else if (sbuf[2] != '\x00')
1190 errstr = "SOCKS5 negotiation protocol error";
1192 else if (sbuf[1] != SOCKS5_REQUEST_GRANTED)
1194 errstr = translate_socks5_error(sbuf[1]);
1198 if (sbuf[3] == '\x04')
1201 * The address field contains an IPv6 address
1202 * which means we didn't get the whole reply
1203 * yet. Read and discard the rest of it to make
1204 * sure it isn't treated as HTTP data later on.
1206 server_size = read_socket(sfd, sbuf, SOCKS5_REPLY_DIFFERENCE);
1207 if (server_size != SOCKS5_REPLY_DIFFERENCE)
1209 errstr = "SOCKS5 negotiation read failed (IPv6 address)";
1212 else if (sbuf[3] != '\x01')
1214 errstr = "SOCKS5 reply contains unsupported address type";
1223 assert(errstr != NULL);
1224 csp->error_message = strdup(errstr);
1225 log_error(LOG_LEVEL_CONNECT, "socks5_connect: %s", errstr);
1229 return(JB_INVALID_SOCKET);