tor-android/external/badvpn_dns/misc/get_iface_info.h

111 lines
3.5 KiB
C

/**
* @file get_iface_info.h
* @author Ambroz Bizjak <ambrop7@gmail.com>
*
* @section LICENSE
*
* 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. Neither the name of the author nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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.
*/
#ifndef BADVPN_GETIFACEINFO_H
#define BADVPN_GETIFACEINFO_H
#include <stdio.h>
#include <string.h>
#include <stdint.h>
#include <unistd.h>
#include <sys/socket.h>
#include <net/if.h>
#include <net/if_arp.h>
#include <sys/ioctl.h>
#include <misc/debug.h>
/**
* Returns information about a network interface with the given name.
*
* @param ifname name of interface to get information for
* @param out_mac the MAC address will be returned here, unless NULL
* @param out_mtu the MTU will be returned here, unless NULL
* @param out_ifindex the interface index will be returned here, unless NULL
* @return 1 on success, 0 on failure
*/
static int badvpn_get_iface_info (const char *ifname, uint8_t *out_mac, int *out_mtu, int *out_ifindex) WARN_UNUSED;
static int badvpn_get_iface_info (const char *ifname, uint8_t *out_mac, int *out_mtu, int *out_ifindex)
{
ASSERT(ifname)
struct ifreq ifr;
int s = socket(AF_INET, SOCK_DGRAM, 0);
if (s < 0) {
goto fail0;
}
// get MAC
if (out_mac) {
memset(&ifr, 0, sizeof(ifr));
snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s", ifname);
if (ioctl(s, SIOCGIFHWADDR, &ifr)) {
goto fail1;
}
if (ifr.ifr_hwaddr.sa_family != ARPHRD_ETHER) {
goto fail1;
}
memcpy(out_mac, ifr.ifr_hwaddr.sa_data, 6);
}
// get MTU
if (out_mtu) {
memset(&ifr, 0, sizeof(ifr));
snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s", ifname);
if (ioctl(s, SIOCGIFMTU, &ifr)) {
goto fail1;
}
*out_mtu = ifr.ifr_mtu;
}
// get interface index
if (out_ifindex) {
memset(&ifr, 0, sizeof(ifr));
snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s", ifname);
if (ioctl(s, SIOCGIFINDEX, &ifr)) {
goto fail1;
}
*out_ifindex = ifr.ifr_ifindex;
}
close(s);
return 1;
fail1:
close(s);
fail0:
return 0;
}
#endif