1 const char gateway_rcs[] = "$Id: gateway.c,v 1.14 2002/03/24 13:25:43 swa 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 the SourceForge
11 * Privoxy team. http://www.privoxy.org/
13 * Based on the Internet Junkbuster originally written
14 * by and Copyright (C) 1997 Anonymous Coders and
15 * Junkbusters Corporation. http://www.junkbusters.com
17 * This program is free software; you can redistribute it
18 * and/or modify it under the terms of the GNU General
19 * Public License as published by the Free Software
20 * Foundation; either version 2 of the License, or (at
21 * your option) any later version.
23 * This program is distributed in the hope that it will
24 * be useful, but WITHOUT ANY WARRANTY; without even the
25 * implied warranty of MERCHANTABILITY or FITNESS FOR A
26 * PARTICULAR PURPOSE. See the GNU General Public
27 * License for more details.
29 * The GNU General Public License should be included with
30 * this file. If not, you can view it at
31 * http://www.gnu.org/copyleft/gpl.html
32 * or write to the Free Software Foundation, Inc., 59
33 * Temple Place - Suite 330, Boston, MA 02111-1307, USA.
37 * Revision 1.14 2002/03/24 13:25:43 swa
38 * name change related issues
40 * Revision 1.13 2002/03/13 00:29:59 jongfoster
43 * Revision 1.12 2002/03/09 20:03:52 jongfoster
44 * - Making various functions return int rather than size_t.
45 * (Undoing a recent change). Since size_t is unsigned on
46 * Windows, functions like read_socket that return -1 on
47 * error cannot return a size_t.
49 * THIS WAS A MAJOR BUG - it caused frequent, unpredictable
50 * crashes, and also frequently caused JB to jump to 100%
51 * CPU and stay there. (Because it thought it had just
52 * read ((unsigned)-1) == 4Gb of data...)
54 * - The signature of write_socket has changed, it now simply
55 * returns success=0/failure=nonzero.
57 * - Trying to get rid of a few warnings --with-debug on
58 * Windows, I've introduced a new type "jb_socket". This is
59 * used for the socket file descriptors. On Windows, this
60 * is SOCKET (a typedef for unsigned). Everywhere else, it's
61 * an int. The error value can't be -1 any more, so it's
62 * now JB_INVALID_SOCKET (which is -1 on UNIX, and in
63 * Windows it maps to the #define INVALID_SOCKET.)
65 * - The signature of bind_port has changed.
67 * Revision 1.11 2002/03/08 17:46:04 jongfoster
68 * Fixing int/size_t warnings
70 * Revision 1.10 2002/03/07 03:50:19 oes
71 * - Improved handling of failed DNS lookups
72 * - Fixed compiler warnings
74 * Revision 1.9 2001/10/25 03:40:48 david__schmidt
75 * Change in porting tactics: OS/2's EMX porting layer doesn't allow multiple
76 * threads to call select() simultaneously. So, it's time to do a real, live,
77 * native OS/2 port. See defines for __EMX__ (the porting layer) vs. __OS2__
78 * (native). Both versions will work, but using __OS2__ offers multi-threading.
80 * Revision 1.8 2001/09/13 20:10:12 jongfoster
81 * Fixing missing #include under Windows
83 * Revision 1.7 2001/09/12 17:58:26 steudten
85 * add #include <string.h>
87 * Revision 1.6 2001/09/10 10:41:16 oes
90 * Revision 1.5 2001/07/29 18:47:57 jongfoster
91 * Adding missing #include project.h
93 * Revision 1.4 2001/07/24 12:47:06 oes
94 * Applied BeOS support update by Eugenia
96 * Revision 1.3 2001/06/09 10:55:28 jongfoster
97 * Changing BUFSIZ ==> BUFFER_SIZE
99 * Revision 1.2 2001/06/07 23:11:38 jongfoster
100 * Removing gateways[] list - no longer used.
101 * Replacing function pointer in struct gateway with a directly
102 * called function forwarded_connect(), which can do the common
103 * task of deciding whether to connect to the web server or HTTP
105 * Replacing struct gateway with struct forward_spec
106 * Fixing bug with SOCKS4A and HTTP proxy server in combination.
107 * It was a bug which led to the connection being made to the web
108 * server rather than the HTTP proxy, and also a buffer overrun.
110 * Revision 1.1.1.1 2001/05/15 13:58:54 oes
111 * Initial import of version 2.9.3 source tree
114 *********************************************************************/
120 #include <sys/types.h>
123 #include <netinet/in.h>
130 #include <winsock2.h>
131 #endif /* def _WIN32 */
135 #endif /* def __BEOS__ */
139 #endif /* def __OS2__ */
144 #include "jbsockets.h"
147 const char gateway_h_rcs[] = GATEWAY_H_VERSION;
149 static jb_socket socks4_connect(const struct forward_spec * fwd,
150 const char * target_host,
152 struct client_state *csp);
155 #define SOCKS_REQUEST_GRANTED 90
156 #define SOCKS_REQUEST_REJECT 91
157 #define SOCKS_REQUEST_IDENT_FAILED 92
158 #define SOCKS_REQUEST_IDENT_CONFLICT 93
160 /* structure of a socks client operation */
162 unsigned char vn; /* socks version number */
163 unsigned char cd; /* command code */
164 unsigned char dstport[2]; /* destination port */
165 unsigned char dstip[4]; /* destination address */
166 unsigned char userid; /* first byte of userid */
167 /* more bytes of the userid follow, terminated by a NULL */
170 /* structure of a socks server reply */
172 unsigned char vn; /* socks version number */
173 unsigned char cd; /* command code */
174 unsigned char dstport[2]; /* destination port */
175 unsigned char dstip[4]; /* destination address */
178 static const char socks_userid[] = "anonymous";
181 /*********************************************************************
183 * Function : forwarded_connect
185 * Description : Connect to a specified web server, possibly via
186 * a HTTP proxy and/or a SOCKS proxy.
189 * 1 : gw = pointer to a gateway structure (such as gw_default)
190 * 2 : http = the http request and apropos headers
191 * 3 : csp = Current client state (buffers, headers, etc...)
193 * Returns : -1 => failure, else it is the socket file descriptor.
195 *********************************************************************/
196 jb_socket forwarded_connect(const struct forward_spec * fwd,
197 struct http_request *http,
198 struct client_state *csp)
200 const char * dest_host;
203 /* Figure out if we need to connect to the web server or a HTTP proxy. */
204 if (fwd->forward_host)
207 dest_host = fwd->forward_host;
208 dest_port = fwd->forward_port;
213 dest_host = http->host;
214 dest_port = http->port;
217 /* Connect, maybe using a SOCKS proxy */
221 return (connect_to(dest_host, dest_port, csp));
225 return (socks4_connect(fwd, dest_host, dest_port, csp));
228 /* Should never get here */
229 log_error(LOG_LEVEL_FATAL, "SOCKS4 impossible internal error - bad SOCKS type.");
231 return(JB_INVALID_SOCKET);
236 /*********************************************************************
238 * Function : socks4_connect
240 * Description : Connect to the SOCKS server, and connect through
241 * it to the specified server. This handles
242 * all the SOCKS negotiation, and returns a file
243 * descriptor for a socket which can be treated as a
244 * normal (non-SOCKS) socket.
247 * 1 : gw = pointer to a gateway structure (such as gw_default)
248 * 2 : http = the http request and apropos headers
249 * 3 : csp = Current client state (buffers, headers, etc...)
251 * Returns : -1 => failure, else a socket file descriptor.
253 *********************************************************************/
254 static jb_socket socks4_connect(const struct forward_spec * fwd,
255 const char * target_host,
257 struct client_state *csp)
260 char cbuf[BUFFER_SIZE];
261 char sbuf[BUFFER_SIZE];
262 struct socks_op *c = (struct socks_op *)cbuf;
263 struct socks_reply *s = (struct socks_reply *)sbuf;
270 if ((fwd->gateway_host == NULL) || (*fwd->gateway_host == '\0'))
272 log_error(LOG_LEVEL_CONNECT, "socks4_connect: NULL gateway host specified");
276 if (fwd->gateway_port <= 0)
278 log_error(LOG_LEVEL_CONNECT, "socks4_connect: invalid gateway port specified");
285 return(JB_INVALID_SOCKET);
288 /* build a socks request for connection to the web server */
290 strcpy((char *)&(c->userid), socks_userid);
292 csiz = sizeof(*c) + sizeof(socks_userid) - 1;
297 web_server_addr = htonl(resolve_hostname_to_ip(target_host));
298 if (web_server_addr == INADDR_NONE)
300 log_error(LOG_LEVEL_CONNECT, "socks4_connect: could not resolve target host %s", target_host);
301 return(JB_INVALID_SOCKET);
305 web_server_addr = 0x00000001;
306 n = csiz + strlen(target_host) + 1;
307 if (n > sizeof(cbuf))
310 return(JB_INVALID_SOCKET);
312 strcpy(cbuf + csiz, target_host);
316 /* Should never get here */
317 log_error(LOG_LEVEL_FATAL, "SOCKS4 impossible internal error - bad SOCKS type.");
319 return(JB_INVALID_SOCKET);
324 c->dstport[0] = (target_port >> 8 ) & 0xff;
325 c->dstport[1] = (target_port ) & 0xff;
326 c->dstip[0] = (web_server_addr >> 24 ) & 0xff;
327 c->dstip[1] = (web_server_addr >> 16 ) & 0xff;
328 c->dstip[2] = (web_server_addr >> 8 ) & 0xff;
329 c->dstip[3] = (web_server_addr ) & 0xff;
331 /* pass the request to the socks server */
332 sfd = connect_to(fwd->gateway_host, fwd->gateway_port, csp);
334 if (sfd == JB_INVALID_SOCKET)
336 return(JB_INVALID_SOCKET);
339 if (write_socket(sfd, (char *)c, csiz))
341 log_error(LOG_LEVEL_CONNECT, "SOCKS4 negotiation write failed...");
343 return(JB_INVALID_SOCKET);
346 if (read_socket(sfd, sbuf, sizeof(sbuf)) != sizeof(*s))
348 log_error(LOG_LEVEL_CONNECT, "SOCKS4 negotiation read failed...");
350 return(JB_INVALID_SOCKET);
355 case SOCKS_REQUEST_GRANTED:
358 case SOCKS_REQUEST_REJECT:
359 errstr = "SOCKS request rejected or failed";
362 case SOCKS_REQUEST_IDENT_FAILED:
363 errstr = "SOCKS request rejected because "
364 "SOCKS server cannot connect to identd on the client";
367 case SOCKS_REQUEST_IDENT_CONFLICT:
368 errstr = "SOCKS request rejected because "
369 "the client program and identd report "
370 "different user-ids";
377 "SOCKS request rejected for reason code %d\n", s->cd);
380 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s ...", errstr);
383 return(JB_INVALID_SOCKET);