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523767660c
curl/lib/socks.c
Daniel Stenberg 48064f8dee if we read zero bytes from the proxy, the connection is broken and we need 
to bail out
2007-06-05 13:42:23 +00:00

606 lines
18 KiB
C
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/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 1998 - 2007, Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at http://curl.haxx.se/docs/copyright.html.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the COPYING file.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
* $Id$
***************************************************************************/
#include "setup.h"
#include <string.h>
#ifdef NEED_MALLOC_H
#include <malloc.h>
#endif
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#ifdef HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif
#include "urldata.h"
#include "sendf.h"
#include "strequal.h"
#include "select.h"
#include "connect.h"
#include "timeval.h"
#include "socks.h"
/* The last #include file should be: */
#include "memdebug.h"
/*
* Helper read-from-socket functions. Does the same as Curl_read() but it
* blocks until all bytes amount of buffersize will be read. No more, no less.
*
* This is STUPID BLOCKING behaviour which we frown upon, but right now this
* is what we have...
*/
static int blockread_all(struct connectdata *conn, /* connection data */
curl_socket_t sockfd, /* read from this socket */
char *buf, /* store read data here */
ssize_t buffersize, /* max amount to read */
ssize_t *n, /* amount bytes read */
long conn_timeout) /* timeout for data wait
relative to
conn->created */
{
ssize_t nread;
ssize_t allread = 0;
int result;
struct timeval tvnow;
long conntime;
*n = 0;
do {
tvnow = Curl_tvnow();
/* calculating how long connection is establishing */
conntime = Curl_tvdiff(tvnow, conn->created);
if(conntime > conn_timeout) {
/* we already got the timeout */
result = ~CURLE_OK;
break;
}
if(Curl_socket_ready(sockfd, CURL_SOCKET_BAD,
(int)(conn_timeout - conntime)) <= 0) {
result = ~CURLE_OK;
break;
}
result = Curl_read(conn, sockfd, buf, buffersize, &nread);
if(result)
break;
if(buffersize == nread) {
allread += nread;
*n = allread;
result = CURLE_OK;
break;
}
if(!nread) {
result = ~CURLE_OK;
break;
}
buffersize -= nread;
buf += nread;
allread += nread;
} while(1);
return result;
}
/*
* This function logs in to a SOCKS4 proxy and sends the specifics to the final
* destination server.
*
* Reference :
* http://socks.permeo.com/protocol/socks4.protocol
*
* Note :
* Nonsupport "SOCKS 4A (Simple Extension to SOCKS 4 Protocol)"
* Nonsupport "Identification Protocol (RFC1413)"
*/
CURLcode Curl_SOCKS4(const char *proxy_name,
char *hostname,
int remote_port,
int sockindex,
struct connectdata *conn)
{
unsigned char socksreq[262]; /* room for SOCKS4 request incl. user id */
int result;
CURLcode code;
curl_socket_t sock = conn->sock[sockindex];
long timeout;
struct SessionHandle *data = conn->data;
/* get timeout */
if(data->set.timeout && data->set.connecttimeout) {
if (data->set.timeout < data->set.connecttimeout)
timeout = data->set.timeout;
else
timeout = data->set.connecttimeout;
}
else if(data->set.timeout)
timeout = data->set.timeout;
else if(data->set.connecttimeout)
timeout = data->set.connecttimeout;
else
timeout = DEFAULT_CONNECT_TIMEOUT;
Curl_nonblock(sock, FALSE);
/*
* Compose socks4 request
*
* Request format
*
* +----+----+----+----+----+----+----+----+----+----+....+----+
* | VN | CD | DSTPORT | DSTIP | USERID |NULL|
* +----+----+----+----+----+----+----+----+----+----+....+----+
* # of bytes: 1 1 2 4 variable 1
*/
socksreq[0] = 4; /* version (SOCKS4) */
socksreq[1] = 1; /* connect */
*((unsigned short*)&socksreq[2]) = htons((unsigned short)remote_port);
/* DNS resolve */
{
struct Curl_dns_entry *dns;
Curl_addrinfo *hp=NULL;
int rc;
rc = Curl_resolv(conn, hostname, remote_port, &dns);
if(rc == CURLRESOLV_ERROR)
return CURLE_COULDNT_RESOLVE_PROXY;
if(rc == CURLRESOLV_PENDING)
/* this requires that we're in "wait for resolve" state */
rc = Curl_wait_for_resolv(conn, &dns);
/*
* We cannot use 'hostent' as a struct that Curl_resolv() returns. It
* returns a Curl_addrinfo pointer that may not always look the same.
*/
if(dns)
hp=dns->addr;
if (hp) {
char buf[64];
unsigned short ip[4];
Curl_printable_address(hp, buf, sizeof(buf));
if(4 == sscanf( buf, "%hu.%hu.%hu.%hu",
&ip[0], &ip[1], &ip[2], &ip[3])) {
/* Set DSTIP */
socksreq[4] = (unsigned char)ip[0];
socksreq[5] = (unsigned char)ip[1];
socksreq[6] = (unsigned char)ip[2];
socksreq[7] = (unsigned char)ip[3];
}
else
hp = NULL; /* fail! */
Curl_resolv_unlock(data, dns); /* not used anymore from now on */
}
if(!hp) {
failf(data, "Failed to resolve \"%s\" for SOCKS4 connect.",
hostname);
return CURLE_COULDNT_RESOLVE_HOST;
}
}
/*
* This is currently not supporting "Identification Protocol (RFC1413)".
*/
socksreq[8] = 0; /* ensure empty userid is NUL-terminated */
if (proxy_name)
strlcat((char*)socksreq + 8, proxy_name, sizeof(socksreq) - 8);
/*
* Make connection
*/
{
ssize_t actualread;
ssize_t written;
int packetsize = 9 +
(int)strlen((char*)socksreq + 8); /* size including NUL */
/* Send request */
code = Curl_write(conn, sock, (char *)socksreq, packetsize, &written);
if ((code != CURLE_OK) || (written != packetsize)) {
failf(data, "Failed to send SOCKS4 connect request.");
return CURLE_COULDNT_CONNECT;
}
packetsize = 8; /* receive data size */
/* Receive response */
result = blockread_all(conn, sock, (char *)socksreq, packetsize,
&actualread, timeout);
if ((result != CURLE_OK) || (actualread != packetsize)) {
failf(data, "Failed to receive SOCKS4 connect request ack.");
return CURLE_COULDNT_CONNECT;
}
/*
* Response format
*
* +----+----+----+----+----+----+----+----+
* | VN | CD | DSTPORT | DSTIP |
* +----+----+----+----+----+----+----+----+
* # of bytes: 1 1 2 4
*
* VN is the version of the reply code and should be 0. CD is the result
* code with one of the following values:
*
* 90: request granted
* 91: request rejected or failed
* 92: request rejected because SOCKS server cannot connect to
* identd on the client
* 93: request rejected because the client program and identd
* report different user-ids
*/
/* wrong version ? */
if (socksreq[0] != 0) {
failf(data,
"SOCKS4 reply has wrong version, version should be 4.");
return CURLE_COULDNT_CONNECT;
}
/* Result */
switch(socksreq[1])
{
case 90:
infof(data, "SOCKS4 request granted.\n");
break;
case 91:
failf(data,
"Can't complete SOCKS4 connection to %d.%d.%d.%d:%d. (%d)"
", request rejected or failed.",
(unsigned char)socksreq[4], (unsigned char)socksreq[5],
(unsigned char)socksreq[6], (unsigned char)socksreq[7],
(unsigned int)ntohs(*(unsigned short*)(&socksreq[8])),
socksreq[1]);
return CURLE_COULDNT_CONNECT;
case 92:
failf(data,
"Can't complete SOCKS4 connection to %d.%d.%d.%d:%d. (%d)"
", request rejected because SOCKS server cannot connect to "
"identd on the client.",
(unsigned char)socksreq[4], (unsigned char)socksreq[5],
(unsigned char)socksreq[6], (unsigned char)socksreq[7],
(unsigned int)ntohs(*(unsigned short*)(&socksreq[8])),
socksreq[1]);
return CURLE_COULDNT_CONNECT;
case 93:
failf(data,
"Can't complete SOCKS4 connection to %d.%d.%d.%d:%d. (%d)"
", request rejected because the client program and identd "
"report different user-ids.",
(unsigned char)socksreq[4], (unsigned char)socksreq[5],
(unsigned char)socksreq[6], (unsigned char)socksreq[7],
(unsigned int)ntohs(*(unsigned short*)(&socksreq[8])),
socksreq[1]);
return CURLE_COULDNT_CONNECT;
default:
failf(data,
"Can't complete SOCKS4 connection to %d.%d.%d.%d:%d. (%d)"
", Unknown.",
(unsigned char)socksreq[4], (unsigned char)socksreq[5],
(unsigned char)socksreq[6], (unsigned char)socksreq[7],
(unsigned int)ntohs(*(unsigned short*)(&socksreq[8])),
socksreq[1]);
return CURLE_COULDNT_CONNECT;
}
}
Curl_nonblock(sock, TRUE);
return CURLE_OK; /* Proxy was successful! */
}
/*
* This function logs in to a SOCKS5 proxy and sends the specifics to the final
* destination server.
*/
CURLcode Curl_SOCKS5(const char *proxy_name,
const char *proxy_password,
char *hostname,
int remote_port,
int sockindex,
struct connectdata *conn)
{
/*
According to the RFC1928, section "6. Replies". This is what a SOCK5
replies:
+----+-----+-------+------+----------+----------+
|VER | REP | RSV | ATYP | BND.ADDR | BND.PORT |
+----+-----+-------+------+----------+----------+
| 1 | 1 | X'00' | 1 | Variable | 2 |
+----+-----+-------+------+----------+----------+
Where:
o VER protocol version: X'05'
o REP Reply field:
o X'00' succeeded
*/
unsigned char socksreq[600]; /* room for large user/pw (255 max each) */
ssize_t actualread;
ssize_t written;
int result;
CURLcode code;
curl_socket_t sock = conn->sock[sockindex];
struct SessionHandle *data = conn->data;
long timeout;
/* get timeout */
if(data->set.timeout && data->set.connecttimeout) {
if (data->set.timeout < data->set.connecttimeout)
timeout = data->set.timeout;
else
timeout = data->set.connecttimeout;
}
else if(data->set.timeout)
timeout = data->set.timeout;
else if(data->set.connecttimeout)
timeout = data->set.connecttimeout;
else
timeout = DEFAULT_CONNECT_TIMEOUT;
Curl_nonblock(sock, TRUE);
/* wait until socket gets connected */
result = Curl_socket_ready(CURL_SOCKET_BAD, sock, (int)timeout);
if(-1 == result) {
failf(conn->data, "SOCKS5: no connection here");
return CURLE_COULDNT_CONNECT;
}
else if(0 == result) {
failf(conn->data, "SOCKS5: connection timeout");
return CURLE_OPERATION_TIMEDOUT;
}
if(result & CURL_CSELECT_ERR) {
failf(conn->data, "SOCKS5: error occured during connection");
return CURLE_COULDNT_CONNECT;
}
socksreq[0] = 5; /* version */
socksreq[1] = (char)(proxy_name ? 2 : 1); /* number of methods (below) */
socksreq[2] = 0; /* no authentication */
socksreq[3] = 2; /* username/password */
Curl_nonblock(sock, FALSE);
code = Curl_write(conn, sock, (char *)socksreq, (2 + (int)socksreq[1]),
&written);
if ((code != CURLE_OK) || (written != (2 + (int)socksreq[1]))) {
failf(data, "Unable to send initial SOCKS5 request.");
return CURLE_COULDNT_CONNECT;
}
Curl_nonblock(sock, TRUE);
result = Curl_socket_ready(sock, CURL_SOCKET_BAD, (int)timeout);
if(-1 == result) {
failf(conn->data, "SOCKS5 nothing to read");
return CURLE_COULDNT_CONNECT;
}
else if(0 == result) {
failf(conn->data, "SOCKS5 read timeout");
return CURLE_OPERATION_TIMEDOUT;
}
if(result & CURL_CSELECT_ERR) {
failf(conn->data, "SOCKS5 read error occured");
return CURLE_RECV_ERROR;
}
Curl_nonblock(sock, FALSE);
result=blockread_all(conn, sock, (char *)socksreq, 2, &actualread, timeout);
if ((result != CURLE_OK) || (actualread != 2)) {
failf(data, "Unable to receive initial SOCKS5 response.");
return CURLE_COULDNT_CONNECT;
}
if (socksreq[0] != 5) {
failf(data, "Received invalid version in initial SOCKS5 response.");
return CURLE_COULDNT_CONNECT;
}
if (socksreq[1] == 0) {
/* Nothing to do, no authentication needed */
;
}
else if (socksreq[1] == 2) {
/* Needs user name and password */
size_t userlen, pwlen;
int len;
if(proxy_name && proxy_password) {
userlen = strlen(proxy_name);
pwlen = strlen(proxy_password);
}
else {
userlen = 0;
pwlen = 0;
}
/* username/password request looks like
* +----+------+----------+------+----------+
* |VER | ULEN | UNAME | PLEN | PASSWD |
* +----+------+----------+------+----------+
* | 1 | 1 | 1 to 255 | 1 | 1 to 255 |
* +----+------+----------+------+----------+
*/
len = 0;
socksreq[len++] = 1; /* username/pw subnegotiation version */
socksreq[len++] = (char) userlen;
memcpy(socksreq + len, proxy_name, (int) userlen);
len += userlen;
socksreq[len++] = (char) pwlen;
memcpy(socksreq + len, proxy_password, (int) pwlen);
len += pwlen;
code = Curl_write(conn, sock, (char *)socksreq, len, &written);
if ((code != CURLE_OK) || (len != written)) {
failf(data, "Failed to send SOCKS5 sub-negotiation request.");
return CURLE_COULDNT_CONNECT;
}
result=blockread_all(conn, sock, (char *)socksreq, 2, &actualread,
timeout);
if ((result != CURLE_OK) || (actualread != 2)) {
failf(data, "Unable to receive SOCKS5 sub-negotiation response.");
return CURLE_COULDNT_CONNECT;
}
/* ignore the first (VER) byte */
if (socksreq[1] != 0) { /* status */
failf(data, "User was rejected by the SOCKS5 server (%d %d).",
socksreq[0], socksreq[1]);
return CURLE_COULDNT_CONNECT;
}
/* Everything is good so far, user was authenticated! */
}
else {
/* error */
if (socksreq[1] == 1) {
failf(data,
"SOCKS5 GSSAPI per-message authentication is not supported.");
return CURLE_COULDNT_CONNECT;
}
else if (socksreq[1] == 255) {
if (!proxy_name || !*proxy_name) {
failf(data,
"No authentication method was acceptable. (It is quite likely"
" that the SOCKS5 server wanted a username/password, since none"
" was supplied to the server on this connection.)");
}
else {
failf(data, "No authentication method was acceptable.");
}
return CURLE_COULDNT_CONNECT;
}
else {
failf(data,
"Undocumented SOCKS5 mode attempted to be used by server.");
return CURLE_COULDNT_CONNECT;
}
}
/* Authentication is complete, now specify destination to the proxy */
socksreq[0] = 5; /* version (SOCKS5) */
socksreq[1] = 1; /* connect */
socksreq[2] = 0; /* must be zero */
socksreq[3] = 1; /* IPv4 = 1 */
{
struct Curl_dns_entry *dns;
Curl_addrinfo *hp=NULL;
int rc = Curl_resolv(conn, hostname, remote_port, &dns);
if(rc == CURLRESOLV_ERROR)
return CURLE_COULDNT_RESOLVE_HOST;
if(rc == CURLRESOLV_PENDING)
/* this requires that we're in "wait for resolve" state */
rc = Curl_wait_for_resolv(conn, &dns);
/*
* We cannot use 'hostent' as a struct that Curl_resolv() returns. It
* returns a Curl_addrinfo pointer that may not always look the same.
*/
if(dns)
hp=dns->addr;
if (hp) {
char buf[64];
unsigned short ip[4];
Curl_printable_address(hp, buf, sizeof(buf));
if(4 == sscanf( buf, "%hu.%hu.%hu.%hu",
&ip[0], &ip[1], &ip[2], &ip[3])) {
socksreq[4] = (unsigned char)ip[0];
socksreq[5] = (unsigned char)ip[1];
socksreq[6] = (unsigned char)ip[2];
socksreq[7] = (unsigned char)ip[3];
}
else
hp = NULL; /* fail! */
Curl_resolv_unlock(data, dns); /* not used anymore from now on */
}
if(!hp) {
failf(data, "Failed to resolve \"%s\" for SOCKS5 connect.",
hostname);
return CURLE_COULDNT_RESOLVE_HOST;
}
}
*((unsigned short*)&socksreq[8]) = htons((unsigned short)remote_port);
{
const int packetsize = 10;
code = Curl_write(conn, sock, (char *)socksreq, packetsize, &written);
if ((code != CURLE_OK) || (written != packetsize)) {
failf(data, "Failed to send SOCKS5 connect request.");
return CURLE_COULDNT_CONNECT;
}
result = blockread_all(conn, sock, (char *)socksreq, packetsize,
&actualread, timeout);
if ((result != CURLE_OK) || (actualread != packetsize)) {
failf(data, "Failed to receive SOCKS5 connect request ack.");
return CURLE_COULDNT_CONNECT;
}
if (socksreq[0] != 5) { /* version */
failf(data,
"SOCKS5 reply has wrong version, version should be 5.");
return CURLE_COULDNT_CONNECT;
}
if (socksreq[1] != 0) { /* Anything besides 0 is an error */
failf(data,
"Can't complete SOCKS5 connection to %d.%d.%d.%d:%d. (%d)",
(unsigned char)socksreq[4], (unsigned char)socksreq[5],
(unsigned char)socksreq[6], (unsigned char)socksreq[7],
(unsigned int)ntohs(*(unsigned short*)(&socksreq[8])),
socksreq[1]);
return CURLE_COULDNT_CONNECT;
}
}
Curl_nonblock(sock, TRUE);
return CURLE_OK; /* Proxy was successful! */
}
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