static EVENT_HANDLER(listening)
{
char buf[1024];
size_t len = sizeof(buf);
int link, from;
double rx_signal, rx_angle;
CHECK(CNET_read_physical(&link, buf, &len));
memcpy(&from, buf, sizeof(int));
CHECK(CNET_wlan_arrival(link, &rx_signal, &rx_angle));
fprintf(stdout,"\t\t%d: received from %d (%.3fdBm @%.3f)\n",
nodeinfo.nodenumber, from, rx_signal, rx_angle);
}
static EVENT_HANDLER(receive)
{
WLAN_FRAME frame;
size_t len;
int link;
// READ THE ARRIVING FRAME FROM OUR PHYSICAL LINK
len = sizeof(frame);
CHECK(CNET_read_physical(&link, &frame, &len));
if(verbose) {
double rx_signal;
CHECK(CNET_wlan_arrival(link, &rx_signal, NULL));
fprintf(stdout, "\t%5s: received '%s' @%.3fdBm\n",
nodeinfo.nodename, frame.payload, rx_signal);
}
// IS THIS FRAME FOR ME?
if(frame.header.dest == nodeinfo.nodenumber) {
++stats[1];
if(verbose)
fprintf(stdout, "\t\tfor me!\n");
}
// NO; RETRANSMIT FRAME IF WE'RE CLOSER TO THE DESTINATION THAN THE PREV NODE
else {
CnetPosition dest = positions[frame.header.dest];
double prev = distance(frame.header.prevpos, dest);
double now = distance(positions[nodeinfo.nodenumber],dest);
if(now < prev) { // closer?
frame.header.prevpos = positions[nodeinfo.nodenumber]; // me!
len = sizeof(WLAN_HEADER) + frame.header.length;
CHECK(CNET_write_physical_reliable(link, &frame, &len));
if(verbose)
fprintf(stdout, "\t\tretransmitting\n");
}
}
}