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tor-android/external/privoxy/gateway.c

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const char gateway_rcs[] = "$Id: gateway.c,v 1.48 2009/02/13 17:20:36 fabiankeil Exp $";
/*********************************************************************
*
* File : $Source: /cvsroot/ijbswa/current/gateway.c,v $
*
* Purpose : Contains functions to connect to a server, possibly
* using a "forwarder" (i.e. HTTP proxy and/or a SOCKS4
* or SOCKS5 proxy).
*
* Copyright : Written by and Copyright (C) 2001-2009 the SourceForge
* Privoxy team. http://www.privoxy.org/
*
* Based on the Internet Junkbuster originally written
* by and Copyright (C) 1997 Anonymous Coders and
* Junkbusters Corporation. http://www.junkbusters.com
*
* This program is free software; you can redistribute it
* and/or modify it under the terms of the GNU General
* Public License as published by the Free Software
* Foundation; either version 2 of the License, or (at
* your option) any later version.
*
* This program is distributed in the hope that it will
* be useful, but WITHOUT ANY WARRANTY; without even the
* implied warranty of MERCHANTABILITY or FITNESS FOR A
* PARTICULAR PURPOSE. See the GNU General Public
* License for more details.
*
* The GNU General Public License should be included with
* this file. If not, you can view it at
* http://www.gnu.org/copyleft/gpl.html
* or write to the Free Software Foundation, Inc., 59
* Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* Revisions :
* $Log: gateway.c,v $
* Revision 1.48 2009/02/13 17:20:36 fabiankeil
* Reword keep-alive support warning and only show
* it #if !defined(HAVE_POLL) && !defined(_WIN32).
*
* Revision 1.47 2008/12/24 17:06:19 fabiankeil
* Keep a thread around to timeout alive connections
* even if no new requests are coming in.
*
* Revision 1.46 2008/12/13 11:07:23 fabiankeil
* Remove duplicated debugging checks
* in connection_destination_matches().
*
* Revision 1.45 2008/12/04 18:17:07 fabiankeil
* Fix some cparser warnings.
*
* Revision 1.44 2008/11/22 11:54:04 fabiankeil
* Move log message around to include the socket number.
*
* Revision 1.43 2008/11/13 09:15:51 fabiankeil
* Make keep_alive_timeout static.
*
* Revision 1.42 2008/11/13 09:08:42 fabiankeil
* Add new config option: keep-alive-timeout.
*
* Revision 1.41 2008/11/08 15:29:58 fabiankeil
* Unify two debug messages.
*
* Revision 1.40 2008/11/08 15:14:05 fabiankeil
* Fix duplicated debugging check.
*
* Revision 1.39 2008/10/25 11:33:01 fabiankeil
* Remove already out-commented line left over from debugging.
*
* Revision 1.38 2008/10/24 17:33:00 fabiankeil
* - Tone the "keep-alive support is experimental" warning
* down a bit as hackish 0-chunk detection has been
* implemented recently.
* - Only show the "ndef HAVE_POLL" warning once on start-up.
*
* Revision 1.37 2008/10/23 17:40:53 fabiankeil
* Fix forget_connection() and mark_connection_unused(),
* which would both under certain circumstances access
* reusable_connection[MAX_REUSABLE_CONNECTIONS]. Oops.
*
* Revision 1.36 2008/10/18 19:49:15 fabiankeil
* - Factor close_unusable_connections() out of
* get_reusable_connection() to make sure we really check
* all the remembered connections, not just the ones before
* the next reusable one.
* - Plug two file descriptor leaks. Internally marking
* connections as closed doesn't cut it.
*
* Revision 1.35 2008/10/17 17:12:01 fabiankeil
* In socket_is_still_usable(), use select()
* and FD_ISSET() if poll() isn't available.
*
* Revision 1.34 2008/10/17 17:07:13 fabiankeil
* Add preliminary timeout support.
*
* Revision 1.33 2008/10/16 16:34:21 fabiankeil
* Fix two gcc44 warnings.
*
* Revision 1.32 2008/10/16 16:27:22 fabiankeil
* Fix compiler warning.
*
* Revision 1.31 2008/10/16 07:31:11 fabiankeil
* - Factor socket_is_still_usable() out of get_reusable_connection().
* - If poll() isn't available, show a warning and assume the socket
* is still usable.
*
* Revision 1.30 2008/10/13 17:31:03 fabiankeil
* If a remembered connection is no longer usable and
* has been marked closed, don't bother checking if the
* destination matches.
*
* Revision 1.29 2008/10/11 16:59:41 fabiankeil
* Add missing dots for two log messages.
*
* Revision 1.28 2008/10/09 18:21:41 fabiankeil
* Flush work-in-progress changes to keep outgoing connections
* alive where possible. Incomplete and mostly #ifdef'd out.
*
* Revision 1.27 2008/09/27 15:05:51 fabiankeil
* Return only once in forwarded_connect().
*
* Revision 1.26 2008/08/18 17:42:06 fabiankeil
* Fix typo in macro name.
*
* Revision 1.25 2008/02/07 18:09:46 fabiankeil
* In socks5_connect:
* - make the buffers quite a bit smaller.
* - properly report "socks5 server unreachable" failures.
* - let strncpy() use the whole buffer. Using a length of 0xffu wasn't actually
* wrong, but requires too much thinking as it doesn't depend on the buffer size.
* - log a message if the socks5 server sends more data than expected.
* - add some assertions and comments.
*
* Revision 1.24 2008/02/04 14:56:29 fabiankeil
* - Fix a compiler warning.
* - Stop assuming that htonl(INADDR_NONE) equals INADDR_NONE.
*
* Revision 1.23 2008/02/04 13:11:35 fabiankeil
* Remember the cause of the SOCKS5 error for the CGI message.
*
* Revision 1.22 2008/02/03 13:46:15 fabiankeil
* Add SOCKS5 support. Patch #1862863 by Eric M. Hopper with minor changes.
*
* Revision 1.21 2007/07/28 12:30:03 fabiankeil
* Modified patch from Song Weijia (#1762559) to
* fix socks requests on big-endian platforms.
*
* Revision 1.20 2007/05/14 10:23:48 fabiankeil
* - Use strlcpy() instead of strcpy().
* - Use the same buffer for socks requests and socks responses.
* - Fix bogus warning about web_server_addr being used uninitialized.
*
* Revision 1.19 2007/01/25 14:09:45 fabiankeil
* - Save errors in socks4_connect() to csp->error_message.
* - Silence some gcc43 warnings, hopefully the right way.
*
* Revision 1.18 2006/07/18 14:48:46 david__schmidt
* Reorganizing the repository: swapping out what was HEAD (the old 3.1 branch)
* with what was really the latest development (the v_3_0_branch branch)
*
* Revision 1.16 2002/05/12 21:36:29 jongfoster
* Correcting function comments
*
* Revision 1.15 2002/03/26 22:29:54 swa
* we have a new homepage!
*
* Revision 1.14 2002/03/24 13:25:43 swa
* name change related issues
*
* Revision 1.13 2002/03/13 00:29:59 jongfoster
* Killing warnings
*
* Revision 1.12 2002/03/09 20:03:52 jongfoster
* - Making various functions return int rather than size_t.
* (Undoing a recent change). Since size_t is unsigned on
* Windows, functions like read_socket that return -1 on
* error cannot return a size_t.
*
* THIS WAS A MAJOR BUG - it caused frequent, unpredictable
* crashes, and also frequently caused JB to jump to 100%
* CPU and stay there. (Because it thought it had just
* read ((unsigned)-1) == 4Gb of data...)
*
* - The signature of write_socket has changed, it now simply
* returns success=0/failure=nonzero.
*
* - Trying to get rid of a few warnings --with-debug on
* Windows, I've introduced a new type "jb_socket". This is
* used for the socket file descriptors. On Windows, this
* is SOCKET (a typedef for unsigned). Everywhere else, it's
* an int. The error value can't be -1 any more, so it's
* now JB_INVALID_SOCKET (which is -1 on UNIX, and in
* Windows it maps to the #define INVALID_SOCKET.)
*
* - The signature of bind_port has changed.
*
* Revision 1.11 2002/03/08 17:46:04 jongfoster
* Fixing int/size_t warnings
*
* Revision 1.10 2002/03/07 03:50:19 oes
* - Improved handling of failed DNS lookups
* - Fixed compiler warnings
*
* Revision 1.9 2001/10/25 03:40:48 david__schmidt
* Change in porting tactics: OS/2's EMX porting layer doesn't allow multiple
* threads to call select() simultaneously. So, it's time to do a real, live,
* native OS/2 port. See defines for __EMX__ (the porting layer) vs. __OS2__
* (native). Both versions will work, but using __OS2__ offers multi-threading.
*
* Revision 1.8 2001/09/13 20:10:12 jongfoster
* Fixing missing #include under Windows
*
* Revision 1.7 2001/09/12 17:58:26 steudten
*
* add #include <string.h>
*
* Revision 1.6 2001/09/10 10:41:16 oes
* Added #include in.h
*
* Revision 1.5 2001/07/29 18:47:57 jongfoster
* Adding missing #include project.h
*
* Revision 1.4 2001/07/24 12:47:06 oes
* Applied BeOS support update by Eugenia
*
* Revision 1.3 2001/06/09 10:55:28 jongfoster
* Changing BUFSIZ ==> BUFFER_SIZE
*
* Revision 1.2 2001/06/07 23:11:38 jongfoster
* Removing gateways[] list - no longer used.
* Replacing function pointer in struct gateway with a directly
* called function forwarded_connect(), which can do the common
* task of deciding whether to connect to the web server or HTTP
* proxy.
* Replacing struct gateway with struct forward_spec
* Fixing bug with SOCKS4A and HTTP proxy server in combination.
* It was a bug which led to the connection being made to the web
* server rather than the HTTP proxy, and also a buffer overrun.
*
* Revision 1.1.1.1 2001/05/15 13:58:54 oes
* Initial import of version 2.9.3 source tree
*
*
*********************************************************************/
#include "config.h"
#include <stdio.h>
#include <sys/types.h>
#ifndef _WIN32
#include <netinet/in.h>
#endif
#include <errno.h>
#include <string.h>
#include "assert.h"
#ifdef _WIN32
#include <winsock2.h>
#endif /* def _WIN32 */
#ifdef __BEOS__
#include <netdb.h>
#endif /* def __BEOS__ */
#ifdef __OS2__
#include <utils.h>
#endif /* def __OS2__ */
#include "project.h"
#include "jcc.h"
#include "errlog.h"
#include "jbsockets.h"
#include "gateway.h"
#include "miscutil.h"
#ifdef FEATURE_CONNECTION_KEEP_ALIVE
#ifdef HAVE_POLL
#ifdef __GLIBC__
#include <sys/poll.h>
#else
#include <poll.h>
#endif /* def __GLIBC__ */
#endif /* HAVE_POLL */
#endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
const char gateway_h_rcs[] = GATEWAY_H_VERSION;
static jb_socket socks4_connect(const struct forward_spec * fwd,
const char * target_host,
int target_port,
struct client_state *csp);
static jb_socket socks5_connect(const struct forward_spec *fwd,
const char *target_host,
int target_port,
struct client_state *csp);
#define SOCKS_REQUEST_GRANTED 90
#define SOCKS_REQUEST_REJECT 91
#define SOCKS_REQUEST_IDENT_FAILED 92
#define SOCKS_REQUEST_IDENT_CONFLICT 93
#define SOCKS5_REQUEST_GRANTED 0
#define SOCKS5_REQUEST_FAILED 1
#define SOCKS5_REQUEST_DENIED 2
#define SOCKS5_REQUEST_NETWORK_UNREACHABLE 3
#define SOCKS5_REQUEST_HOST_UNREACHABLE 4
#define SOCKS5_REQUEST_CONNECTION_REFUSED 5
#define SOCKS5_REQUEST_TTL_EXPIRED 6
#define SOCKS5_REQUEST_PROTOCOL_ERROR 7
#define SOCKS5_REQUEST_BAD_ADDRESS_TYPE 8
/* structure of a socks client operation */
struct socks_op {
unsigned char vn; /* socks version number */
unsigned char cd; /* command code */
unsigned char dstport[2]; /* destination port */
unsigned char dstip[4]; /* destination address */
char userid; /* first byte of userid */
char padding[3]; /* make sure sizeof(struct socks_op) is endian-independent. */
/* more bytes of the userid follow, terminated by a NULL */
};
/* structure of a socks server reply */
struct socks_reply {
unsigned char vn; /* socks version number */
unsigned char cd; /* command code */
unsigned char dstport[2]; /* destination port */
unsigned char dstip[4]; /* destination address */
};
static const char socks_userid[] = "anonymous";
#ifdef FEATURE_CONNECTION_KEEP_ALIVE
#define MAX_REUSABLE_CONNECTIONS 100
static int keep_alive_timeout = DEFAULT_KEEP_ALIVE_TIMEOUT;
struct reusable_connection
{
jb_socket sfd;
int in_use;
char *host;
int port;
time_t timestamp;
int forwarder_type;
char *gateway_host;
int gateway_port;
char *forward_host;
int forward_port;
};
static struct reusable_connection reusable_connection[MAX_REUSABLE_CONNECTIONS];
static int mark_connection_unused(jb_socket sfd);
static void mark_connection_closed(struct reusable_connection *closed_connection);
static int socket_is_still_usable(jb_socket sfd);
/*********************************************************************
*
* Function : initialize_reusable_connections
*
* Description : Initializes the reusable_connection structures.
* Must be called with connection_reuse_mutex locked.
*
* Parameters : N/A
*
* Returns : void
*
*********************************************************************/
extern void initialize_reusable_connections(void)
{
unsigned int slot = 0;
#if !defined(HAVE_POLL) && !defined(_WIN32)
log_error(LOG_LEVEL_INFO,
"Detecting already dead connections might not work "
"correctly on your platform. In case of problems, "
"unset the keep-alive-timeout option.");
#endif
for (slot = 0; slot < SZ(reusable_connection); slot++)
{
mark_connection_closed(&reusable_connection[slot]);
}
log_error(LOG_LEVEL_CONNECT, "Initialized %d socket slots.", slot);
}
/*********************************************************************
*
* Function : remember_connection
*
* Description : Remembers a connection for reuse later on.
*
* Parameters :
* 1 : sfd = Open socket to remember.
* 2 : http = The destination for the connection.
* 3 : fwd = The forwarder settings used.
*
* Returns : void
*
*********************************************************************/
void remember_connection(jb_socket sfd, const struct http_request *http,
const struct forward_spec *fwd)
{
unsigned int slot = 0;
int free_slot_found = FALSE;
assert(sfd != JB_INVALID_SOCKET);
if (mark_connection_unused(sfd))
{
return;
}
privoxy_mutex_lock(&connection_reuse_mutex);
/* Find free socket slot. */
for (slot = 0; slot < SZ(reusable_connection); slot++)
{
if (reusable_connection[slot].sfd == JB_INVALID_SOCKET)
{
assert(reusable_connection[slot].in_use == 0);
log_error(LOG_LEVEL_CONNECT,
"Remembering socket %d for %s:%d in slot %d.",
sfd, http->host, http->port, slot);
free_slot_found = TRUE;
break;
}
}
if (!free_slot_found)
{
log_error(LOG_LEVEL_CONNECT,
"No free slots found to remembering socket for %s:%d. Last slot %d.",
http->host, http->port, slot);
privoxy_mutex_unlock(&connection_reuse_mutex);
close_socket(sfd);
return;
}
assert(NULL != http->host);
reusable_connection[slot].host = strdup(http->host);
if (NULL == reusable_connection[slot].host)
{
log_error(LOG_LEVEL_FATAL, "Out of memory saving socket.");
}
reusable_connection[slot].sfd = sfd;
reusable_connection[slot].port = http->port;
reusable_connection[slot].in_use = 0;
reusable_connection[slot].timestamp = time(NULL);
assert(NULL != fwd);
assert(reusable_connection[slot].gateway_host == NULL);
assert(reusable_connection[slot].gateway_port == 0);
assert(reusable_connection[slot].forwarder_type == SOCKS_NONE);
assert(reusable_connection[slot].forward_host == NULL);
assert(reusable_connection[slot].forward_port == 0);
reusable_connection[slot].forwarder_type = fwd->type;
if (NULL != fwd->gateway_host)
{
reusable_connection[slot].gateway_host = strdup(fwd->gateway_host);
if (NULL == reusable_connection[slot].gateway_host)
{
log_error(LOG_LEVEL_FATAL, "Out of memory saving gateway_host.");
}
}
else
{
reusable_connection[slot].gateway_host = NULL;
}
reusable_connection[slot].gateway_port = fwd->gateway_port;
if (NULL != fwd->forward_host)
{
reusable_connection[slot].forward_host = strdup(fwd->forward_host);
if (NULL == reusable_connection[slot].forward_host)
{
log_error(LOG_LEVEL_FATAL, "Out of memory saving forward_host.");
}
}
else
{
reusable_connection[slot].forward_host = NULL;
}
reusable_connection[slot].forward_port = fwd->forward_port;
privoxy_mutex_unlock(&connection_reuse_mutex);
}
/*********************************************************************
*
* Function : mark_connection_closed
*
* Description : Marks a reused connection closed.
* Must be called with connection_reuse_mutex locked.
*
* Parameters :
* 1 : closed_connection = The connection to mark as closed.
*
* Returns : void
*
*********************************************************************/
static void mark_connection_closed(struct reusable_connection *closed_connection)
{
closed_connection->in_use = FALSE;
closed_connection->sfd = JB_INVALID_SOCKET;
freez(closed_connection->host);
closed_connection->port = 0;
closed_connection->timestamp = 0;
closed_connection->forwarder_type = SOCKS_NONE;
freez(closed_connection->gateway_host);
closed_connection->gateway_port = 0;
freez(closed_connection->forward_host);
closed_connection->forward_port = 0;
}
/*********************************************************************
*
* Function : forget_connection
*
* Description : Removes a previously remembered connection from
* the list of reusable connections.
*
* Parameters :
* 1 : sfd = The socket belonging to the connection in question.
*
* Returns : void
*
*********************************************************************/
void forget_connection(jb_socket sfd)
{
unsigned int slot = 0;
assert(sfd != JB_INVALID_SOCKET);
privoxy_mutex_lock(&connection_reuse_mutex);
for (slot = 0; slot < SZ(reusable_connection); slot++)
{
if (reusable_connection[slot].sfd == sfd)
{
assert(reusable_connection[slot].in_use);
log_error(LOG_LEVEL_CONNECT,
"Forgetting socket %d for %s:%d in slot %d.",
sfd, reusable_connection[slot].host,
reusable_connection[slot].port, slot);
mark_connection_closed(&reusable_connection[slot]);
privoxy_mutex_unlock(&connection_reuse_mutex);
return;
}
}
log_error(LOG_LEVEL_CONNECT,
"Socket %d already forgotten or never remembered.", sfd);
privoxy_mutex_unlock(&connection_reuse_mutex);
}
/*********************************************************************
*
* Function : connection_destination_matches
*
* Description : Determines whether a remembered connection can
* be reused. That is, whether the destination and
* the forwarding settings match.
*
* Parameters :
* 1 : connection = The connection to check.
* 2 : http = The destination for the connection.
* 3 : fwd = The forwarder settings.
*
* Returns : TRUE for yes, FALSE otherwise.
*
*********************************************************************/
static int connection_destination_matches(const struct reusable_connection *connection,
const struct http_request *http,
const struct forward_spec *fwd)
{
if ((connection->forwarder_type != fwd->type)
|| (connection->gateway_port != fwd->gateway_port)
|| (connection->forward_port != fwd->forward_port)
|| (connection->port != http->port))
{
return FALSE;
}
if (( (NULL != connection->gateway_host)
&& (NULL != fwd->gateway_host)
&& strcmpic(connection->gateway_host, fwd->gateway_host))
&& (connection->gateway_host != fwd->gateway_host))
{
log_error(LOG_LEVEL_CONNECT, "Gateway mismatch.");
return FALSE;
}
if (( (NULL != connection->forward_host)
&& (NULL != fwd->forward_host)
&& strcmpic(connection->forward_host, fwd->forward_host))
&& (connection->forward_host != fwd->forward_host))
{
log_error(LOG_LEVEL_CONNECT, "Forwarding proxy mismatch.");
return FALSE;
}
return (!strcmpic(connection->host, http->host));
}
/*********************************************************************
*
* Function : close_unusable_connections
*
* Description : Closes remembered connections that have timed
* out or have been closed on the other side.
*
* Parameters : none
*
* Returns : Number of connections that are still alive.
*
*********************************************************************/
int close_unusable_connections(void)
{
unsigned int slot = 0;
int connections_alive = 0;
privoxy_mutex_lock(&connection_reuse_mutex);
for (slot = 0; slot < SZ(reusable_connection); slot++)
{
if (!reusable_connection[slot].in_use
&& (JB_INVALID_SOCKET != reusable_connection[slot].sfd))
{
time_t time_open = time(NULL) - reusable_connection[slot].timestamp;
if (keep_alive_timeout < time_open)
{
log_error(LOG_LEVEL_CONNECT,
"The connection to %s:%d in slot %d timed out. "
"Closing socket %d. Timeout is: %d.",
reusable_connection[slot].host,
reusable_connection[slot].port, slot,
reusable_connection[slot].sfd, keep_alive_timeout);
close_socket(reusable_connection[slot].sfd);
mark_connection_closed(&reusable_connection[slot]);
}
else if (!socket_is_still_usable(reusable_connection[slot].sfd))
{
log_error(LOG_LEVEL_CONNECT,
"The connection to %s:%d in slot %d is no longer usable. "
"Closing socket %d.", reusable_connection[slot].host,
reusable_connection[slot].port, slot,
reusable_connection[slot].sfd);
close_socket(reusable_connection[slot].sfd);
mark_connection_closed(&reusable_connection[slot]);
}
else
{
connections_alive++;
}
}
}
privoxy_mutex_unlock(&connection_reuse_mutex);
return connections_alive;
}
/*********************************************************************
*
* Function : socket_is_still_usable
*
* Description : Decides whether or not an open socket is still usable.
*
* Parameters :
* 1 : sfd = The socket to check.
*
* Returns : TRUE for yes, otherwise FALSE.
*
*********************************************************************/
static int socket_is_still_usable(jb_socket sfd)
{
#ifdef HAVE_POLL
int poll_result;
struct pollfd poll_fd[1];
memset(poll_fd, 0, sizeof(poll_fd));
poll_fd[0].fd = sfd;
poll_fd[0].events = POLLIN;
poll_result = poll(poll_fd, 1, 0);
if (-1 != poll_result)
{
return !(poll_fd[0].revents & POLLIN);
}
else
{
log_error(LOG_LEVEL_CONNECT, "Polling socket %d failed.", sfd);
return FALSE;
}
#else
fd_set readable_fds;
struct timeval timeout;
int ret;
int socket_is_alive = 0;
memset(&timeout, '\0', sizeof(timeout));
FD_ZERO(&readable_fds);
FD_SET(sfd, &readable_fds);
ret = select((int)sfd+1, &readable_fds, NULL, NULL, &timeout);
if (ret < 0)
{
log_error(LOG_LEVEL_ERROR, "select() failed!: %E");
}
/*
* XXX: I'm not sure why !FD_ISSET() works,
* but apparently it does.
*/
socket_is_alive = !FD_ISSET(sfd, &readable_fds);
return socket_is_alive;
#endif /* def HAVE_POLL */
}
/*********************************************************************
*
* Function : get_reusable_connection
*
* Description : Returns an open socket to a previously remembered
* open connection (if there is one).
*
* Parameters :
* 1 : http = The destination for the connection.
* 2 : fwd = The forwarder settings.
*
* Returns : JB_INVALID_SOCKET => No reusable connection found,
* otherwise a usable socket.
*
*********************************************************************/
static jb_socket get_reusable_connection(const struct http_request *http,
const struct forward_spec *fwd)
{
jb_socket sfd = JB_INVALID_SOCKET;
unsigned int slot = 0;
close_unusable_connections();
privoxy_mutex_lock(&connection_reuse_mutex);
for (slot = 0; slot < SZ(reusable_connection); slot++)
{
if (!reusable_connection[slot].in_use
&& (JB_INVALID_SOCKET != reusable_connection[slot].sfd))
{
if (connection_destination_matches(&reusable_connection[slot], http, fwd))
{
reusable_connection[slot].in_use = TRUE;
sfd = reusable_connection[slot].sfd;
log_error(LOG_LEVEL_CONNECT,
"Found reusable socket %d for %s:%d in slot %d.",
sfd, reusable_connection[slot].host, reusable_connection[slot].port, slot);
break;
}
}
}
privoxy_mutex_unlock(&connection_reuse_mutex);
return sfd;
}
/*********************************************************************
*
* Function : mark_connection_unused
*
* Description : Gives a remembered connection free for reuse.
*
* Parameters :
* 1 : sfd = The socket belonging to the connection in question.
*
* Returns : TRUE => Socket found and marked as unused.
* FALSE => Socket not found.
*
*********************************************************************/
static int mark_connection_unused(jb_socket sfd)
{
unsigned int slot = 0;
int socket_found = FALSE;
assert(sfd != JB_INVALID_SOCKET);
privoxy_mutex_lock(&connection_reuse_mutex);
for (slot = 0; slot < SZ(reusable_connection); slot++)
{
if (reusable_connection[slot].sfd == sfd)
{
assert(reusable_connection[slot].in_use);
socket_found = TRUE;
log_error(LOG_LEVEL_CONNECT,
"Marking open socket %d for %s:%d in slot %d as unused.",
sfd, reusable_connection[slot].host,
reusable_connection[slot].port, slot);
reusable_connection[slot].in_use = 0;
reusable_connection[slot].timestamp = time(NULL);
break;
}
}
privoxy_mutex_unlock(&connection_reuse_mutex);
return socket_found;
}
/*********************************************************************
*
* Function : set_keep_alive_timeout
*
* Description : Sets the timeout after which open
* connections will no longer be reused.
*
* Parameters :
* 1 : timeout = The timeout in seconds.
*
* Returns : void
*
*********************************************************************/
void set_keep_alive_timeout(int timeout)
{
keep_alive_timeout = timeout;
}
#endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
/*********************************************************************
*
* Function : forwarded_connect
*
* Description : Connect to a specified web server, possibly via
* a HTTP proxy and/or a SOCKS proxy.
*
* Parameters :
* 1 : fwd = the proxies to use when connecting.
* 2 : http = the http request and apropos headers
* 3 : csp = Current client state (buffers, headers, etc...)
*
* Returns : JB_INVALID_SOCKET => failure, else it is the socket file descriptor.
*
*********************************************************************/
jb_socket forwarded_connect(const struct forward_spec * fwd,
struct http_request *http,
struct client_state *csp)
{
const char * dest_host;
int dest_port;
jb_socket sfd = JB_INVALID_SOCKET;
#ifdef FEATURE_CONNECTION_KEEP_ALIVE
sfd = get_reusable_connection(http, fwd);
if (JB_INVALID_SOCKET != sfd)
{
return sfd;
}
#endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
/* Figure out if we need to connect to the web server or a HTTP proxy. */
if (fwd->forward_host)
{
/* HTTP proxy */
dest_host = fwd->forward_host;
dest_port = fwd->forward_port;
}
else
{
/* Web server */
dest_host = http->host;
dest_port = http->port;
}
/* Connect, maybe using a SOCKS proxy */
switch (fwd->type)
{
case SOCKS_NONE:
sfd = connect_to(dest_host, dest_port, csp);
break;
case SOCKS_4:
case SOCKS_4A:
sfd = socks4_connect(fwd, dest_host, dest_port, csp);
break;
case SOCKS_5:
sfd = socks5_connect(fwd, dest_host, dest_port, csp);
break;
default:
/* Should never get here */
log_error(LOG_LEVEL_FATAL,
"SOCKS4 impossible internal error - bad SOCKS type.");
}
if (JB_INVALID_SOCKET != sfd)
{
log_error(LOG_LEVEL_CONNECT,
"Created new connection to %s:%d on socket %d.",
http->host, http->port, sfd);
}
return sfd;
}
/*********************************************************************
*
* Function : socks4_connect
*
* Description : Connect to the SOCKS server, and connect through
* it to the specified server. This handles
* all the SOCKS negotiation, and returns a file
* descriptor for a socket which can be treated as a
* normal (non-SOCKS) socket.
*
* Logged error messages are saved to csp->error_message
* and later reused by error_response() for the CGI
* message. strdup allocation failures are handled there.
*
* Parameters :
* 1 : fwd = Specifies the SOCKS proxy to use.
* 2 : target_host = The final server to connect to.
* 3 : target_port = The final port to connect to.
* 4 : csp = Current client state (buffers, headers, etc...)
*
* Returns : JB_INVALID_SOCKET => failure, else a socket file descriptor.
*
*********************************************************************/
static jb_socket socks4_connect(const struct forward_spec * fwd,
const char * target_host,
int target_port,
struct client_state *csp)
{
unsigned int web_server_addr;
char buf[BUFFER_SIZE];
struct socks_op *c = (struct socks_op *)buf;
struct socks_reply *s = (struct socks_reply *)buf;
size_t n;
size_t csiz;
jb_socket sfd;
int err = 0;
char *errstr = NULL;
if ((fwd->gateway_host == NULL) || (*fwd->gateway_host == '\0'))
{
/* XXX: Shouldn't the config file parser prevent this? */
errstr = "NULL gateway host specified.";
err = 1;
}
if (fwd->gateway_port <= 0)
{
errstr = "invalid gateway port specified.";
err = 1;
}
if (err)
{
log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
csp->error_message = strdup(errstr);
errno = EINVAL;
return(JB_INVALID_SOCKET);
}
/* build a socks request for connection to the web server */
strlcpy(&(c->userid), socks_userid, sizeof(buf) - sizeof(struct socks_op));
csiz = sizeof(*c) + sizeof(socks_userid) - sizeof(c->userid) - sizeof(c->padding);
switch (fwd->type)
{
case SOCKS_4:
web_server_addr = resolve_hostname_to_ip(target_host);
if (web_server_addr == INADDR_NONE)
{
errstr = "could not resolve target host";
log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s %s", errstr, target_host);
err = 1;
}
else
{
web_server_addr = htonl(web_server_addr);
}
break;
case SOCKS_4A:
web_server_addr = 0x00000001;
n = csiz + strlen(target_host) + 1;
if (n > sizeof(buf))
{
errno = EINVAL;
errstr = "buffer cbuf too small.";
log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
err = 1;
}
else
{
strlcpy(buf + csiz, target_host, sizeof(buf) - sizeof(struct socks_op) - csiz);
/*
* What we forward to the socks4a server should have the
* size of socks_op, plus the length of the userid plus
* its \0 byte (which we don't have to add because the
* first byte of the userid is counted twice as it's also
* part of sock_op) minus the padding bytes (which are part
* of the userid as well), plus the length of the target_host
* (which is stored csiz bytes after the beginning of the buffer),
* plus another \0 byte.
*/
assert(n == sizeof(struct socks_op) + strlen(&(c->userid)) - sizeof(c->padding) + strlen(buf + csiz) + 1);
csiz = n;
}
break;
default:
/* Should never get here */
log_error(LOG_LEVEL_FATAL,
"socks4_connect: SOCKS4 impossible internal error - bad SOCKS type.");
/* Not reached */
return(JB_INVALID_SOCKET);
}
if (err)
{
csp->error_message = strdup(errstr);
return(JB_INVALID_SOCKET);
}
c->vn = 4;
c->cd = 1;
c->dstport[0] = (unsigned char)((target_port >> 8 ) & 0xff);
c->dstport[1] = (unsigned char)((target_port ) & 0xff);
c->dstip[0] = (unsigned char)((web_server_addr >> 24 ) & 0xff);
c->dstip[1] = (unsigned char)((web_server_addr >> 16 ) & 0xff);
c->dstip[2] = (unsigned char)((web_server_addr >> 8 ) & 0xff);
c->dstip[3] = (unsigned char)((web_server_addr ) & 0xff);
/* pass the request to the socks server */
sfd = connect_to(fwd->gateway_host, fwd->gateway_port, csp);
if (sfd == JB_INVALID_SOCKET)
{
/*
* XXX: connect_to should fill in the exact reason.
* Most likely resolving the IP of the forwarder failed.
*/
errstr = "connect_to failed: see logfile for details";
err = 1;
}
else if (write_socket(sfd, (char *)c, csiz))
{
errstr = "SOCKS4 negotiation write failed.";
log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
err = 1;
close_socket(sfd);
}
else if (read_socket(sfd, buf, sizeof(buf)) != sizeof(*s))
{
errstr = "SOCKS4 negotiation read failed.";
log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
err = 1;
close_socket(sfd);
}
if (err)
{
csp->error_message = strdup(errstr);
return(JB_INVALID_SOCKET);
}
switch (s->cd)
{
case SOCKS_REQUEST_GRANTED:
return(sfd);
case SOCKS_REQUEST_REJECT:
errstr = "SOCKS request rejected or failed.";
errno = EINVAL;
break;
case SOCKS_REQUEST_IDENT_FAILED:
errstr = "SOCKS request rejected because "
"SOCKS server cannot connect to identd on the client.";
errno = EACCES;
break;
case SOCKS_REQUEST_IDENT_CONFLICT:
errstr = "SOCKS request rejected because "
"the client program and identd report "
"different user-ids.";
errno = EACCES;
break;
default:
errno = ENOENT;
snprintf(buf, sizeof(buf),
"SOCKS request rejected for reason code %d.", s->cd);
errstr = buf;
}
log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
csp->error_message = strdup(errstr);
close_socket(sfd);
return(JB_INVALID_SOCKET);
}
/*********************************************************************
*
* Function : translate_socks5_error
*
* Description : Translates a SOCKS errors to a string.
*
* Parameters :
* 1 : socks_error = The error code to translate.
*
* Returns : The string translation.
*
*********************************************************************/
static const char *translate_socks5_error(int socks_error)
{
switch (socks_error)
{
/* XXX: these should be more descriptive */
case SOCKS5_REQUEST_FAILED:
return "SOCKS5 request failed";
case SOCKS5_REQUEST_DENIED:
return "SOCKS5 request denied";
case SOCKS5_REQUEST_NETWORK_UNREACHABLE:
return "SOCKS5 network unreachable";
case SOCKS5_REQUEST_HOST_UNREACHABLE:
return "SOCKS5 host unreachable";
case SOCKS5_REQUEST_CONNECTION_REFUSED:
return "SOCKS5 connection refused";
case SOCKS5_REQUEST_TTL_EXPIRED:
return "SOCKS5 TTL expired";
case SOCKS5_REQUEST_PROTOCOL_ERROR:
return "SOCKS5 client protocol error";
case SOCKS5_REQUEST_BAD_ADDRESS_TYPE:
return "SOCKS5 domain names unsupported";
case SOCKS5_REQUEST_GRANTED:
return "everything's peachy";
default:
return "SOCKS5 negotiation protocol error";
}
}
/*********************************************************************
*
* Function : socks5_connect
*
* Description : Connect to the SOCKS server, and connect through
* it to the specified server. This handles
* all the SOCKS negotiation, and returns a file
* descriptor for a socket which can be treated as a
* normal (non-SOCKS) socket.
*
* Parameters :
* 1 : fwd = Specifies the SOCKS proxy to use.
* 2 : target_host = The final server to connect to.
* 3 : target_port = The final port to connect to.
* 4 : csp = Current client state (buffers, headers, etc...)
*
* Returns : JB_INVALID_SOCKET => failure, else a socket file descriptor.
*
*********************************************************************/
static jb_socket socks5_connect(const struct forward_spec *fwd,
const char *target_host,
int target_port,
struct client_state *csp)
{
int err = 0;
char cbuf[300];
char sbuf[30];
size_t client_pos = 0;
int server_size = 0;
size_t hostlen = 0;
jb_socket sfd;
const char *errstr = NULL;
assert(fwd->gateway_host);
if ((fwd->gateway_host == NULL) || (*fwd->gateway_host == '\0'))
{
errstr = "NULL gateway host specified";
err = 1;
}
if (fwd->gateway_port <= 0)
{
/*
* XXX: currently this can't happen because in
* case of invalid gateway ports we use the defaults.
* Of course we really shouldn't do that.
*/
errstr = "invalid gateway port specified";
err = 1;
}
hostlen = strlen(target_host);
if (hostlen > (size_t)255)
{
errstr = "target host name is longer than 255 characters";
err = 1;
}
if (fwd->type != SOCKS_5)
{
/* Should never get here */
log_error(LOG_LEVEL_FATAL,
"SOCKS5 impossible internal error - bad SOCKS type");
err = 1;
}
if (err)
{
errno = EINVAL;
assert(errstr != NULL);
log_error(LOG_LEVEL_CONNECT, "socks5_connect: %s", errstr);
csp->error_message = strdup(errstr);
return(JB_INVALID_SOCKET);
}
/* pass the request to the socks server */
sfd = connect_to(fwd->gateway_host, fwd->gateway_port, csp);
if (sfd == JB_INVALID_SOCKET)
{
errstr = "socks5 server unreachable";
log_error(LOG_LEVEL_CONNECT, "socks5_connect: %s", errstr);
csp->error_message = strdup(errstr);
return(JB_INVALID_SOCKET);
}
client_pos = 0;
cbuf[client_pos++] = '\x05'; /* Version */
cbuf[client_pos++] = '\x01'; /* One authentication method supported */
cbuf[client_pos++] = '\x00'; /* The no authentication authentication method */
if (write_socket(sfd, cbuf, client_pos))
{
errstr = "SOCKS5 negotiation write failed";
csp->error_message = strdup(errstr);
log_error(LOG_LEVEL_CONNECT, "%s", errstr);
close_socket(sfd);
return(JB_INVALID_SOCKET);
}
if (read_socket(sfd, sbuf, sizeof(sbuf)) != 2)
{
errstr = "SOCKS5 negotiation read failed";
err = 1;
}
if (!err && (sbuf[0] != '\x05'))
{
errstr = "SOCKS5 negotiation protocol version error";
err = 1;
}
if (!err && (sbuf[1] == '\xff'))
{
errstr = "SOCKS5 authentication required";
err = 1;
}
if (!err && (sbuf[1] != '\x00'))
{
errstr = "SOCKS5 negotiation protocol error";
err = 1;
}
if (err)
{
assert(errstr != NULL);
log_error(LOG_LEVEL_CONNECT, "socks5_connect: %s", errstr);
csp->error_message = strdup(errstr);
close_socket(sfd);
errno = EINVAL;
return(JB_INVALID_SOCKET);
}
client_pos = 0;
cbuf[client_pos++] = '\x05'; /* Version */
cbuf[client_pos++] = '\x01'; /* TCP connect */
cbuf[client_pos++] = '\x00'; /* Reserved, must be 0x00 */
cbuf[client_pos++] = '\x03'; /* Address is domain name */
cbuf[client_pos++] = (char)(hostlen & 0xffu);
assert(sizeof(cbuf) - client_pos > (size_t)255);
/* Using strncpy because we really want the nul byte padding. */
strncpy(cbuf + client_pos, target_host, sizeof(cbuf) - client_pos);
client_pos += (hostlen & 0xffu);
cbuf[client_pos++] = (char)((target_port >> 8) & 0xff);
cbuf[client_pos++] = (char)((target_port ) & 0xff);
if (write_socket(sfd, cbuf, client_pos))
{
errstr = "SOCKS5 negotiation read failed";
csp->error_message = strdup(errstr);
log_error(LOG_LEVEL_CONNECT, "%s", errstr);
close_socket(sfd);
errno = EINVAL;
return(JB_INVALID_SOCKET);
}
server_size = read_socket(sfd, sbuf, sizeof(sbuf));
if (server_size < 3)
{
errstr = "SOCKS5 negotiation read failed";
err = 1;
}
else if (server_size > 20)
{
/* This is somewhat unexpected but doesn't realy matter. */
log_error(LOG_LEVEL_CONNECT, "socks5_connect: read %d bytes "
"from socks server. Would have accepted up to %d.",
server_size, sizeof(sbuf));
}
if (!err && (sbuf[0] != '\x05'))
{
errstr = "SOCKS5 negotiation protocol version error";
err = 1;
}
if (!err && (sbuf[2] != '\x00'))
{
errstr = "SOCKS5 negotiation protocol error";
err = 1;
}
if (!err)
{
if (sbuf[1] == SOCKS5_REQUEST_GRANTED)
{
return(sfd);
}
errstr = translate_socks5_error(sbuf[1]);
err = 1;
}
assert(errstr != NULL);
csp->error_message = strdup(errstr);
log_error(LOG_LEVEL_CONNECT, "socks5_connect: %s", errstr);
close_socket(sfd);
errno = EINVAL;
return(JB_INVALID_SOCKET);
}
/*
Local Variables:
tab-width: 3
end:
*/
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