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/* horst - Highly Optimized Radio Scanning Tool
*
* Copyright (C) 2005-2014 Bruno Randolf (br1@einfach.org)
*
* 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 2
* 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <netpacket/packet.h>
#include <net/ethernet.h>
#include <net/if.h>
#include <arpa/inet.h>
#include <err.h>
#include "capture.h"
#include "util.h"
#include "main.h"
static int
device_index(int fd, const char *devname)
{
struct ifreq req;
strncpy(req.ifr_name, devname, IFNAMSIZ);
req.ifr_addr.sa_family = AF_INET;
if (ioctl(fd, SIOCGIFINDEX, &req) < 0)
err(1, "Interface %s not found", devname);
if (req.ifr_ifindex < 0)
err(1, "Interface %s not found", devname);
DEBUG("index %d\n", req.ifr_ifindex);
return req.ifr_ifindex;
}
static void
device_promisc(int fd, const char *devname, int on)
{
struct ifreq req;
strncpy(req.ifr_name, devname, IFNAMSIZ);
req.ifr_addr.sa_family = AF_INET;
if (ioctl(fd, SIOCGIFFLAGS, &req) < 0)
err(1, "Could not get device flags for %s", devname);
/* put interface up in any case */
req.ifr_flags |= IFF_UP;
if (on)
req.ifr_flags |= IFF_PROMISC;
else
req.ifr_flags &= ~IFF_PROMISC;
if (ioctl(fd, SIOCSIFFLAGS, &req) < 0)
err(1, "Could not set promisc mode for %s", devname);
}
/*
* Get the hardware type of the given interface as ARPHRD_xxx constant.
*/
int
device_get_hwinfo(int fd, char* ifname, unsigned char* mac)
{
struct ifreq ifr;
memset(&ifr, 0, sizeof(ifr));
strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
if (ioctl(fd, SIOCGIFHWADDR, &ifr) < 0)
err(1, "Could not get arptype");
DEBUG("ARPTYPE %d\n", ifr.ifr_hwaddr.sa_family);
memcpy(mac, ifr.ifr_hwaddr.sa_data, 6);
DEBUG("MY MAC %s\n", ether_sprintf(mac));
return ifr.ifr_hwaddr.sa_family;
}
static void
set_receive_buffer(int fd, int sockbufsize)
{
int ret;
/* the maximum allowed value is set by the rmem_max sysctl */
FILE* PF = fopen("/proc/sys/net/core/rmem_max", "w");
fprintf(PF, "%d", sockbufsize);
fclose(PF);
ret = setsockopt (fd, SOL_SOCKET, SO_RCVBUF, &sockbufsize, sizeof(sockbufsize));
if (ret != 0)
err(1, "setsockopt failed");
#if DO_DEBUG
socklen_t size = sizeof(sockbufsize);
sockbufsize = 0;
ret = getsockopt(fd, SOL_SOCKET, SO_RCVBUF, &sockbufsize, &size);
if (ret != 0)
err(1, "getsockopt failed");
DEBUG("socket receive buffer size %d\n", sockbufsize);
#endif
}
int
open_packet_socket(char* devname, int recv_buffer_size)
{
int ret;
int mon_fd;
int ifindex;
struct sockaddr_ll sall;
mon_fd = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
if (mon_fd < 0) {
printf("Could not create packet socket! Please run horst as root!\n");
exit(1);
}
/* bind only to one interface */
ifindex = device_index(mon_fd, devname);
memset(&sall, 0, sizeof(struct sockaddr_ll));
sall.sll_ifindex = ifindex;
sall.sll_family = AF_PACKET;
sall.sll_protocol = htons(ETH_P_ALL);
ret = bind(mon_fd, (struct sockaddr*)&sall, sizeof(sall));
if (ret != 0)
err(1, "bind failed");
device_promisc(mon_fd, devname, 1);
if (recv_buffer_size)
set_receive_buffer(mon_fd, recv_buffer_size);
return mon_fd;
}
inline int
recv_packet(int fd, unsigned char* buffer, size_t bufsize)
{
return recv(fd, buffer, bufsize, MSG_DONTWAIT);
}
void
close_packet_socket(int fd, char* ifname)
{
if (fd > 0) {
device_promisc(fd, ifname, 0);
close(fd);
}
}
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