-const char gateway_rcs[] = "$Id: gateway.c,v 1.14 2002/03/24 13:25:43 swa Exp $";
+const char gateway_rcs[] = "$Id: gateway.c,v 1.24 2008/02/04 14:56:29 fabiankeil Exp $";
/*********************************************************************
*
* File : $Source: /cvsroot/ijbswa/current/gateway.c,v $
* using a "forwarder" (i.e. HTTP proxy and/or a SOCKS4
* proxy).
*
- * Copyright : Written by and Copyright (C) 2001 the SourceForge
+ * Copyright : Written by and Copyright (C) 2001-2007 the SourceForge
* Privoxy team. http://www.privoxy.org/
*
* Based on the Internet Junkbuster originally written
*
* Revisions :
* $Log: gateway.c,v $
+ * 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
*
#include <errno.h>
#include <string.h>
+#include "assert.h"
#ifdef _WIN32
#include <winsock2.h>
#include "errlog.h"
#include "jbsockets.h"
#include "gateway.h"
+#include "miscutil.h"
const char gateway_h_rcs[] = GATEWAY_H_VERSION;
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_REFUSEDD 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 */
- unsigned char userid; /* first byte of userid */
+ 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 */
};
* a HTTP proxy and/or a SOCKS proxy.
*
* Parameters :
- * 1 : gw = pointer to a gateway structure (such as gw_default)
+ * 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 : -1 => failure, else it is the socket file descriptor.
+ * Returns : JB_INVALID_SOCKET => failure, else it is the socket file descriptor.
*
*********************************************************************/
jb_socket forwarded_connect(const struct forward_spec * fwd,
case SOCKS_4A:
return (socks4_connect(fwd, dest_host, dest_port, csp));
+ case SOCKS_5:
+ return (socks5_connect(fwd, dest_host, dest_port, csp));
+
default:
/* Should never get here */
log_error(LOG_LEVEL_FATAL, "SOCKS4 impossible internal error - bad SOCKS type.");
* 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 : gw = pointer to a gateway structure (such as gw_default)
- * 2 : http = the http request and apropos headers
- * 3 : csp = Current client state (buffers, headers, etc...)
+ * 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 : -1 => failure, else a socket file descriptor.
+ * Returns : JB_INVALID_SOCKET => failure, else a socket file descriptor.
*
*********************************************************************/
static jb_socket socks4_connect(const struct forward_spec * fwd,
int target_port,
struct client_state *csp)
{
- int web_server_addr;
- char cbuf[BUFFER_SIZE];
- char sbuf[BUFFER_SIZE];
- struct socks_op *c = (struct socks_op *)cbuf;
- struct socks_reply *s = (struct socks_reply *)sbuf;
+ 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;
+ char *errstr = NULL;
if ((fwd->gateway_host == NULL) || (*fwd->gateway_host == '\0'))
{
- log_error(LOG_LEVEL_CONNECT, "socks4_connect: NULL gateway host specified");
+ /* XXX: Shouldn't the config file parser prevent this? */
+ errstr = "NULL gateway host specified.";
err = 1;
}
if (fwd->gateway_port <= 0)
{
- log_error(LOG_LEVEL_CONNECT, "socks4_connect: invalid gateway port specified");
+ 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 */
- strcpy((char *)&(c->userid), socks_userid);
+ strlcpy(&(c->userid), socks_userid, sizeof(buf) - sizeof(struct socks_op));
- csiz = sizeof(*c) + sizeof(socks_userid) - 1;
+ csiz = sizeof(*c) + sizeof(socks_userid) - sizeof(c->userid) - sizeof(c->padding);
switch (fwd->type)
{
case SOCKS_4:
- web_server_addr = htonl(resolve_hostname_to_ip(target_host));
+ web_server_addr = resolve_hostname_to_ip(target_host);
if (web_server_addr == INADDR_NONE)
{
- log_error(LOG_LEVEL_CONNECT, "socks4_connect: could not resolve target host %s", target_host);
- return(JB_INVALID_SOCKET);
+ 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(cbuf))
+ if (n > sizeof(buf))
{
errno = EINVAL;
- return(JB_INVALID_SOCKET);
+ 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;
}
- strcpy(cbuf + csiz, target_host);
- csiz = n;
break;
default:
/* Should never get here */
- log_error(LOG_LEVEL_FATAL, "SOCKS4 impossible internal error - bad SOCKS type.");
- errno = EINVAL;
+ 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] = (target_port >> 8 ) & 0xff;
- c->dstport[1] = (target_port ) & 0xff;
- c->dstip[0] = (web_server_addr >> 24 ) & 0xff;
- c->dstip[1] = (web_server_addr >> 16 ) & 0xff;
- c->dstip[2] = (web_server_addr >> 8 ) & 0xff;
- c->dstip[3] = (web_server_addr ) & 0xff;
+ 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)
{
- return(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;
}
-
- if (write_socket(sfd, (char *)c, csiz))
+ else if (write_socket(sfd, (char *)c, csiz))
{
- log_error(LOG_LEVEL_CONNECT, "SOCKS4 negotiation write failed...");
+ errstr = "SOCKS4 negotiation write failed.";
+ log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
+ err = 1;
close_socket(sfd);
- return(JB_INVALID_SOCKET);
}
-
- if (read_socket(sfd, sbuf, sizeof(sbuf)) != sizeof(*s))
+ else if (read_socket(sfd, buf, sizeof(buf)) != sizeof(*s))
{
- log_error(LOG_LEVEL_CONNECT, "SOCKS4 negotiation read failed...");
+ 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);
}
return(sfd);
break;
case SOCKS_REQUEST_REJECT:
- errstr = "SOCKS request rejected or failed";
+ 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";
+ "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";
+ "different user-ids.";
errno = EACCES;
break;
default:
- errstr = cbuf;
errno = ENOENT;
- sprintf(errstr,
- "SOCKS request rejected for reason code %d\n", s->cd);
+ snprintf(buf, sizeof(buf),
+ "SOCKS request rejected for reason code %d.", s->cd);
+ errstr = buf;
}
- log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s ...", errstr);
-
+ 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_REFUSEDD:
+ 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 > 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 > 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) & 0xffu);
+ cbuf[client_pos++] = (char)((target_port ) & 0xffu);
+
+ 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:
projects / privoxy.git / blobdiff