/*
* Waits for a beacon packet from the target AP and populates the globule->ap_capabilities field.
* This is used for obtaining the capabilities field and AP SSID.
*/
void read_ap_beacon()
{
struct pcap_pkthdr header;
const unsigned char *packet = NULL;
struct radio_tap_header *rt_header = NULL;
struct dot11_frame_header *frame_header = NULL;
struct beacon_management_frame *beacon = NULL;
int channel = 0;
size_t tag_offset = 0;
time_t start_time = 0;
set_ap_capability(0);
start_time = time(NULL);
while(get_ap_capability() == 0)
{
packet = next_packet(&header);
if(packet == NULL)
{
break;
}
if(header.len >= MIN_BEACON_SIZE)
{
rt_header = (struct radio_tap_header *) radio_header(packet, header.len);
size_t rt_header_len = end_le16toh(rt_header->len);
frame_header = (struct dot11_frame_header *) (packet + rt_header_len);
if(is_target(frame_header))
{
if((frame_header->fc & end_htole16(IEEE80211_FCTL_FTYPE | IEEE80211_FCTL_STYPE)) ==
end_htole16(IEEE80211_FTYPE_MGMT | IEEE80211_STYPE_BEACON))
{
beacon = (struct beacon_management_frame *) (packet + rt_header_len + sizeof(struct dot11_frame_header));
set_ap_capability(end_le16toh(beacon->capability));
/* Obtain the SSID and channel number from the beacon packet */
tag_offset = rt_header_len + sizeof(struct dot11_frame_header) + sizeof(struct beacon_management_frame);
channel = parse_beacon_tags(packet, header.len);
/* If no channel was manually specified, switch to the AP's current channel */
if(!get_fixed_channel() && get_auto_channel_select() && channel > 0 && channel != get_channel())
{
change_channel(channel);
set_channel(channel);
}
break;
}
}
}
/* If we haven't seen any beacon packets from the target within BEACON_WAIT_TIME seconds, try another channel */
if((time(NULL) - start_time) >= BEACON_WAIT_TIME)
{
next_channel();
start_time = time(NULL);
}
}
}
/*
* Waits for a beacon packet from the target AP and populates the globule->ap_capabilities field.
* This is used for obtaining the capabilities field and AP SSID.
*/
void read_ap_beacon()
{
struct pcap_pkthdr header;
const u_char *packet = NULL;
struct radio_tap_header *rt_header = NULL;
struct dot11_frame_header *frame_header = NULL;
struct beacon_management_frame *beacon = NULL;
int channel = 0;
time_t start_time = 0;
set_ap_capability(0);
start_time = time(NULL);
while(get_ap_capability() == 0)
{
packet = next_packet(&header);
if(packet == NULL)
{
break;
}
if(header.len >= MIN_BEACON_SIZE)
{
rt_header = (struct radio_tap_header *) radio_header(packet, header.len);
frame_header = (struct dot11_frame_header *) (packet + rt_header->len);
if(is_target(frame_header))
{
if(frame_header->fc.type == MANAGEMENT_FRAME && frame_header->fc.sub_type == SUBTYPE_BEACON)
{
beacon = (struct beacon_management_frame *) (packet + rt_header->len + sizeof(struct dot11_frame_header));
set_ap_capability(beacon->capability);
/* Obtain the SSID and channel number from the beacon packet */
channel = parse_beacon_tags(packet, header.len);
/* If no channel was manually specified, switch to the AP's current channel */
if(!get_fixed_channel() && get_auto_channel_select() && channel > 0 && channel != get_channel())
{
change_channel(channel);
set_channel(channel);
}
break;
}
}
}
/* If we haven't seen any beacon packets from the target within BEACON_WAIT_TIME seconds, try another channel */
if((time(NULL) - start_time) >= BEACON_WAIT_TIME)
{
next_channel();
start_time = time(NULL);
}
}
}
