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#include <errno.h>
#include <fcntl.h>
#include <libwifi.h>
#include <linux/if_packet.h>
#include <net/if.h>
#include <netinet/ether.h>
#include <netinet/ip.h>
#include <pcap/pcap.h>
#include <stdio.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include "beacon_data.h"
static unsigned char kBroadcastAddress[] = "\xFF\xFF\xFF\xFF\xFF\xFF";
int get_interface_mac_address(int sock, const char *interface, unsigned char *output)
{
struct ifreq ifr = {0};
strncpy(ifr.ifr_name, interface, IFNAMSIZ - 1);
if (ioctl(sock, SIOCGIFHWADDR, &ifr) < 0)
{
return -1;
}
memcpy(output, ifr.ifr_hwaddr.sa_data, 6);
return 0;
}
int get_interface_index(int sock, const char *interface, int *index)
{
struct ifreq ifr = {0};
strncpy(ifr.ifr_name, interface, IFNAMSIZ - 1);
if (ioctl(sock, SIOCGIFINDEX, &ifr) < 0)
{
return -1;
}
*index = ifr.ifr_ifindex;
return 0;
}
int make_beacon_frame(int index, const unsigned char tx_addr[6], int seq_number, unsigned char **buf)
{
struct libwifi_beacon beacon = {0};
if (libwifi_create_beacon(&beacon, kBroadcastAddress, tx_addr, tx_addr, NULL, 7))
{
printf("Could not create beacon frame.\n");
return -3;
}
beacon.frame_header.seq_control.sequence_number = seq_number;
static const unsigned char supported_rates[] = {0x82, 0x84, 0x0b, 0x16, 0x24, 0x30, 0x48, 0x6c};
if (libwifi_quick_add_tag(&beacon.tags, TAG_SUPP_RATES, supported_rates, 8)) {
printf("Could not add supported rates tag.\n");
return -7;
}
static const unsigned char extended_supported_rates[] = {0x0c, 0x12, 0x18, 0x60};
if (libwifi_quick_add_tag(&beacon.tags, TAG_EXTENDED_SUPPORTED_RATES, extended_supported_rates, 4)) {
printf("Could not add extended supported rates tag.\n");
return -7;
}
unsigned char payload_data[BEACON_PAYLOAD_LENGTH + 8];
payload_data[0] = 0x00;
payload_data[1] = 0x09;
payload_data[2] = 0xBF;
payload_data[3] = 0x00;
payload_data[4] = 0xFF;
payload_data[5] = 0xFF;
payload_data[6] = 0x00;
payload_data[7] = 0x00;
memcpy(payload_data + 8, kBeaconPayloads[index], BEACON_PAYLOAD_LENGTH);
if (libwifi_quick_add_tag(&beacon.tags, TAG_VENDOR_SPECIFIC, payload_data, BEACON_PAYLOAD_LENGTH + 8))
{
printf("Could not add beacon data tag.\n");
return -6;
}
size_t beacon_size = libwifi_get_beacon_length(&beacon);
unsigned char *beacon_output = (unsigned char *)malloc(beacon_size);
if (beacon_output == NULL)
{
printf("Could not allocate beacon output.\n");
return -4;
}
if (libwifi_dump_beacon(&beacon, beacon_output, beacon_size) < 0)
{
printf("Could not dump beacon.\n");
return -5;
}
libwifi_free_beacon(&beacon);
*buf = beacon_output;
return beacon_size;
}
int prepend_radiotap(const unsigned char *input, int input_size, unsigned char **output)
{
static const unsigned char radiotap[] = "\x00\x00\x08\x00\x00\x00\x00\x00";
static const int radiotap_size = 8;
int output_size = input_size + radiotap_size;
unsigned char *buf = (unsigned char *)malloc(output_size);
if (buf == NULL)
{
return -1;
}
memcpy(buf, radiotap, radiotap_size);
memcpy(buf + radiotap_size, input, input_size);
*output = buf;
return output_size;
}
int send_packet(int sock, int device_index, const unsigned char dst_addr[6], const unsigned char *packet, int packet_size)
{
struct sockaddr_ll socket_address;
socket_address.sll_ifindex = device_index;
socket_address.sll_halen = ETH_ALEN;
memcpy(socket_address.sll_addr, dst_addr, 6);
if (sendto(sock, packet, packet_size, 0, (struct sockaddr *)&socket_address, sizeof(struct sockaddr_ll)) < 0)
{
printf("Could not send packet.\n");
return errno;
}
return 0;
}
int send_packet_with_radiotap(int sock, int device_index, const unsigned char dst_addr[6], const unsigned char *packet, int packet_size)
{
unsigned char *buffer;
int buffer_size = prepend_radiotap(packet, packet_size, &buffer);
if (buffer_size < 0)
{
printf("Could not prepend radiotap.\n");
return -2;
}
int ret = send_packet(sock, device_index, dst_addr, buffer, buffer_size);
free(buffer);
return ret;
}
int main(int argc, char **argv)
{
static const char *interface_name = "mon0";
int sock = socket(AF_PACKET, SOCK_RAW, 0);
if (sock == -1)
{
printf("Could not open socket.\n");
return 1;
}
unsigned char tx_addr[6];
if (get_interface_mac_address(sock, interface_name, tx_addr))
{
printf("Could not get hardware address.\n");
return 2;
}
int device_index = 0;
if (get_interface_index(sock, interface_name, &device_index))
{
printf("Could not get device index.\n");
return 2;
}
int beacon_index = 0;
int seq_number = 0;
for (;;)
{
unsigned char *beacon_output;
int beacon_size = make_beacon_frame(beacon_index, tx_addr, seq_number, &beacon_output);
if (beacon_size < 0)
{
return 3;
}
if (send_packet_with_radiotap(sock, device_index, kBroadcastAddress, beacon_output, beacon_size))
{
return 4;
}
free(beacon_output);
beacon_index = (beacon_index + 1) % 10;
seq_number++;
usleep(1024 * 100);
}
return 0;
}
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