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/* Based on Documentation/networking/tuntap.txt */
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <stdlib.h>
#include <unistd.h>
#include "sis.h"
#ifdef __linux__
#include <sys/socket.h>
#include <sys/file.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <linux/if_tun.h>
#include <linux/if_bridge.h>
#include <net/if_arp.h> /* for ARPHRD_ETHER */
#include <arpa/inet.h>
#include <poll.h>
#define POLLTIME 5000
static struct ifreq ifr;
static int fd, err, sockfd;
static char dev[64];
static int tun_fd, nread, br_socket_fd;
static int br_add_interface (const char *bridge, const char *dev);
static void sis_tap_poll ();
int
sis_tap_init (long unsigned emac)
{
int i;
long unsigned xmac, xmac2;
if (fd)
return 1;
if ((fd = open ("/dev/net/tun", O_RDWR)) < 0)
{
printf ("Cannot open TUN/TAP dev\n");
return 0;
}
memset (&ifr, 0, sizeof (ifr));
/* Flags: IFF_TUN - TUN device (no Ethernet headers)
* IFF_TAP - TAP device
*
* IFF_NO_PI - Do not provide packet information
*/
ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
if ((err = ioctl (fd, TUNSETIFF, (void *) &ifr)) < 0)
{
printf ("ERR: Could not ioctl tun: %s\n", strerror (errno));
close (fd);
return 0;
}
strcpy (dev, ifr.ifr_name);
sockfd = socket (PF_PACKET, SOCK_RAW, htons (ETH_P_ALL));
ifr.ifr_flags = IFF_UP;
if ((err = ioctl (sockfd, SIOCSIFFLAGS, (void *) &ifr)) < 0)
{
printf ("net: could not enable tun %s\n", strerror (errno));
close (fd);
close (sockfd);
return 0;
}
ifr.ifr_hwaddr.sa_family = ARPHRD_ETHER;
xmac = 0;
for (i = 0; i < 6; i++)
{
xmac <<= 8;
xmac |= (emac >> (i * 8)) & 0x0ff;
}
xmac2 = xmac;
memcpy (ifr.ifr_hwaddr.sa_data, &xmac, 6);
if (ioctl (sockfd, SIOCSIFHWADDR, &ifr) < 0)
{
printf ("net: hwaddr error\n");
close (fd);
close (sockfd);
return 0;
}
if (ioctl (sockfd, SIOCGIFHWADDR, &ifr) < 0)
{
printf ("net: hwaddr error\n");
close (fd);
close (sockfd);
return 0;
}
memcpy (&xmac, ifr.ifr_hwaddr.sa_data, 6);
if (xmac != xmac2)
{
printf ("net: could not set hwaddr\n");
close (fd);
close (sockfd);
return 0;
}
printf ("net: using %s, ether %lx", dev, emac);
if (bridge[0])
{
if (br_add_interface (bridge, dev))
{
printf ("ERR: Could not attach %s to bridge %s: %s\n",
dev, bridge, strerror (errno));
/*
close (fd);
close (sockfd);
return 0;
*/
}
else
printf (", bridge %s\n", bridge);
}
printf ("\n");
tun_fd = fd;
event (sis_tap_poll, 0, POLLTIME);
return 1;
}
int
sis_tap_write (unsigned char *buffer, int len)
{
int i, nwrite;
nwrite = write (tun_fd, buffer, len);
if (nread < 0)
{
perror ("Writing from interface");
close (tun_fd);
exit (1);
}
if (sis_verbose)
{
printf ("Write %d bytes to device %s\n", len, dev);
for (i = 0; i < len; i++)
printf ("%02x", buffer[i]);
printf ("\n");
}
}
static void
sis_tap_poll ()
{
struct pollfd fds[1];
int ret;
unsigned char buffer[1536];
fds[0].fd = tun_fd;
fds[0].events = POLLRDNORM;
ret = poll (fds, 1, 0);
if (ret > 0)
{
if (fds[0].revents & POLLRDNORM)
{
nread = read (tun_fd, buffer, 1536);
if (nread < 0)
{
perror ("Reading from interface");
close (tun_fd);
exit (1);
}
greth_rxready (buffer, nread);
}
}
event (sis_tap_poll, 0, POLLTIME);
}
/* Attach tap device to bridge */
/* Taken from bridge-utils-1.6 */
static int
br_add_interface (const char *bridge, const char *dev)
{
struct ifreq ifr;
int err;
int ifindex = if_nametoindex (dev);
if ((br_socket_fd = socket (AF_LOCAL, SOCK_STREAM, 0)) < 0)
return ENODEV;
if (ifindex == 0)
return ENODEV;
strncpy (ifr.ifr_name, bridge, IFNAMSIZ);
#ifdef SIOCBRADDIF
ifr.ifr_ifindex = ifindex;
err = ioctl (br_socket_fd, SIOCBRADDIF, &ifr);
#endif
{
unsigned long args[4] = { BRCTL_ADD_IF, ifindex, 0, 0 };
ifr.ifr_data = (char *) args;
err = ioctl (br_socket_fd, SIOCDEVPRIVATE, &ifr);
}
return err < 0 ? errno : 0;
}
#else
int
sis_tap_init (long unsigned emac)
{
printf ("Error: networking not supported on this host\n");
}
int
sis_tap_write (unsigned char *buffer, int len)
{
printf ("Error: networking not supported on this host\n");
}
#endif
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