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/* $OpenBSD: kqueue-tun.c,v 1.3 2004/02/28 02:22:29 deraadt Exp $ */
/* $Gateweaver: tunkq.c,v 1.2 2003/11/27 22:47:41 cmaxwell Exp $ */
/*
* Copyright 2003 Christopher J. Maxwell <cmaxwell@themanor.net>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/uio.h>
#include <netinet/in.h>
#include <net/if.h>
#include <net/if_tun.h>
#include <errno.h>
#include <err.h>
#include <event.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#define TUN0 "tun98"
#define TUN1 "tun99"
#define TUN0_ADDR "192.0.2.1"
#define TUN1_ADDR "192.0.2.2"
#define TUN_MAXWAIT 5
#define TUN_PINGDEL 1
struct buffer {
u_char *buf;
size_t len;
size_t a;
};
int state;
int tunfd[2];
struct buffer tpkt;
u_char pktbuf[TUNMTU];
struct event tunwev[2];
struct timeval exittv = {TUN_MAXWAIT, 0};
void
tunnel_write(int fd, short which, void *arg)
{
uint32_t type = htonl(AF_INET);
struct iovec iv[2];
int rlen;
int fdkey = (fd == tunfd[0]) ? 0 : 1;
iv[0].iov_base = &type;
iv[0].iov_len = sizeof(type);
iv[1].iov_base = tpkt.buf;
iv[1].iov_len = tpkt.len;
state++;
if ((rlen = writev(fd, iv, 2)) > 0)
fprintf(stderr, "Tunnel %d wrote %ld bytes\n",
fdkey, (long)(rlen - sizeof(type)));
else
errx(1, "Read from tunnel %d failed", fdkey);
}
void
tunnel_read(int fd, short which, void *arg)
{
struct iovec iv[2];
uint32_t type;
int rlen;
int fdkey = (fd == tunfd[0]) ? 0 : 1;
int oppfdkey = (fd == tunfd[0]) ? 1 : 0;
iv[0].iov_base = &type;
iv[0].iov_len = sizeof(type);
iv[1].iov_base = tpkt.buf;
iv[1].iov_len = tpkt.a;
state++;
if ((rlen = readv(fd, iv, 2)) > 0) {
fprintf(stderr, "Tunnel %d read %ld bytes\n",
fdkey, (long)(rlen - sizeof(type)));
tpkt.len = rlen - sizeof(type);
/* add write event on opposite tunnel */
event_add(&tunwev[oppfdkey], &exittv);
} else
errx(1, "Read from tunnel %d failed", fdkey);
}
void
tunnel_ping(int fd, short which, void *arg)
{
system("ping -c 1 -I " TUN0_ADDR " " TUN1_ADDR " >/dev/null &");
}
/*
* +------------+ +------------+
* | TUN0 | | TUN1 |
* | TUN0_ADDR | | TUN1_ADDR |
* +------------+ +------------+
*
* Set up both tunnel devices (TUN0, TUN1)
* This works because the routing table prefers the opposing end of the ptp
* interfaces.
* Set up one read and one write event per tunnel.
* The read events add the write event.
*/
int
do_tun(void)
{
struct event tunrev[2];
struct event pingev;
struct timeval pingtv = {TUN_PINGDEL, 0};
/* read buffer */
tpkt.buf = (u_char *)&pktbuf;
tpkt.len = 0;
tpkt.a = sizeof(pktbuf);
event_init();
/* tun0 */
if ((tunfd[0] = open("/dev/" TUN0, O_RDWR)) < 0)
errx(1, "Cannot open /dev/" TUN0);
event_set(&tunrev[0], tunfd[0], EV_READ, tunnel_read, NULL);
event_set(&tunwev[0], tunfd[0], EV_WRITE, tunnel_write, NULL);
event_add(&tunrev[0], &exittv);
/* tun1 */
if ((tunfd[1] = open("/dev/" TUN1, O_RDWR)) < 0)
errx(1, "Cannot open /dev/" TUN1);
event_set(&tunrev[1], tunfd[1], EV_READ, tunnel_read, NULL);
event_set(&tunwev[1], tunfd[1], EV_WRITE, tunnel_write, NULL);
event_add(&tunrev[1], &exittv);
/* ping */
evtimer_set(&pingev, tunnel_ping, NULL);
event_add(&pingev, &pingtv);
/* configure the interfaces */
system("ifconfig " TUN0 " " TUN0_ADDR
" netmask 255.255.255.255 " TUN1_ADDR);
system("ifconfig " TUN1 " " TUN1_ADDR
" netmask 255.255.255.255 " TUN0_ADDR);
state = 0;
if (event_dispatch() < 0)
errx(errno, "Event handler failed");
return (state != 4);
}
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