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/*
* Copyright (c) 2002-2009 Moxie Marlinspike
*
* 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 3 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
* USA
*/
// XXX define one of these through autoconf
//#define HAVE_PF
#define HAVE_NETFILTER
#include <arpa/inet.h>
#ifdef HAVE_NETFILTER
#include <limits.h>
#include <linux/netfilter_ipv4.h>
#endif
#ifdef HAVE_PF
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <sys/fcntl.h>
#include <net/if.h>
#include <netinet/in.h>
#include <net/pfvar.h>
#endif
#include "util/Destination.hpp"
int Destination::getOriginalDestination(boost::asio::ip::tcp::socket &socket,
boost::asio::ip::tcp::endpoint &originalDestination)
{
#ifdef HAVE_NETFILTER
struct sockaddr_in serverAddr;
int fd = (int)socket.native_handle();
int size = sizeof(serverAddr);
if (getsockopt(fd, SOL_IP, SO_ORIGINAL_DST, &serverAddr, (socklen_t*)&size) < 0) {
perror("Could not determine socket's original destination.");
throw IndeterminateDestinationException();
}
originalDestination = boost::asio::ip::tcp::endpoint(boost::asio::ip::address_v4(ntohl(serverAddr.sin_addr.s_addr)),
ntohs(serverAddr.sin_port));
return 1;
#elif defined(HAVE_PF)
boost::asio::ip::tcp::endpoint le = socket.local_endpoint();
boost::asio::ip::tcp::endpoint re = socket.remote_endpoint();
static int fd = -1;
struct pfioc_natlook nl;
if (fd < 0) {
fd = open("/dev/pf", O_RDONLY);
if (fd >= 0) {
fcntl(fd, F_SETFD, fcntl(fd, F_GETFD) | FD_CLOEXEC);
}
}
if (fd < 0) {
perror("PF open failed");
throw IndeterminateDestinationException();
}
memset(&nl, 0, sizeof(struct pfioc_natlook));
nl.saddr.v4.s_addr = htonl(re.address().to_v4().to_ulong());
nl.sport = htons(re.port());
nl.daddr.v4.s_addr = htonl(le.address().to_v4().to_ulong());
nl.dport = htons(le.port());
nl.af = AF_INET;
nl.proto = IPPROTO_TCP;
nl.direction = PF_OUT;
if (ioctl(fd, DIOCNATLOOK, &nl)) {
if (errno != ENOENT) {
perror("PF lookup failed: ioctl(DIOCNATLOOK)");
close(fd);
fd = -1;
}
throw IndeterminateDestinationException();
}
if (nl.daddr.v4.s_addr == nl.rdaddr.v4.s_addr && nl.dport == nl.rdport) {
/* no destination addr/port rewriting in place */
throw IndeterminateDestinationException();
}
originalDestination = boost::asio::ip::tcp::endpoint(boost::asio::ip::address_v4(ntohl(nl.rdaddr.v4.s_addr)),
ntohs(nl.rdport));
return 1;
#else
throw IndeterminateDestinationException();
#endif
}
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