int main (void)
{
zctx_t *ctx = zctx_new ();
udp_t *udp = udp_new (PING_PORT_NUMBER);
byte buffer [PING_MSG_SIZE];
zmq_pollitem_t pollitems [] = {{ NULL, udp_handle (udp), ZMQ_POLLIN, 0 }};
// Send first ping right away
uint64_t ping_at = zclock_time ();
while (!zctx_interrupted) {
long timeout = (long) (ping_at - zclock_time ());
if (timeout < 0)
timeout = 0;
if (zmq_poll (pollitems, 1, timeout * ZMQ_POLL_MSEC) == -1)
break; // Interrupted
// Someone answered our ping
if (pollitems [0].revents & ZMQ_POLLIN)
udp_recv (udp, buffer, PING_MSG_SIZE);
if (zclock_time () >= ping_at) {
puts ("Pinging peers...");
buffer [0] = '!';
udp_send (udp, buffer, PING_MSG_SIZE);
ping_at = zclock_time () + PING_INTERVAL;
}
}
udp_destroy (&udp);
zctx_destroy (&ctx);
return 0;
}
void ip_handle() {
int * data = ethernet_rx_data + ETHERNET_HDR_LEN;
// not IPv4 or header is longer than 20bit
if(data[IP_VERSION] != IP_VERSION_VAL)
return;
if (data[IP_DST] != IP_ADDR[0] ||
data[IP_DST + 1] != IP_ADDR[1] ||
data[IP_DST + 2] != IP_ADDR[2] ||
data[IP_DST + 3] != IP_ADDR[3]) {
//cprintf("IP destination not correct.\n");
return;
}
int length = (data[IP_TOTAL_LEN] << 8) | data[IP_TOTAL_LEN + 1];
length -= 20; // ip header
if(data[IP_PROTOCAL] == IP_PROTOCAL_ICMP)
icmp_handle(length);
else if(data[IP_PROTOCAL] == IP_PROTOCAL_TCP)
tcp_handle(length);
else if (data[IP_PROTOCAL] == IP_PROTOCAL_UDP) {
//cprintf("udp\n");
udp_handle(length);
}
else
cprintf("unknown protocal %x\n", data[IP_PROTOCAL]);
}
static void* run_discovery(void* data) {
discovery_opts_t* opts = (discovery_opts_t*)data;
char ip[INET_ADDRSTRLEN] = { '\0' };
const char* interface = opts->interface;
udp_t *udp = udp_new(PING_PORT_NUMBER, interface);
assert(udp);
struct pollfd ufds[1];
int ret;
time_t t0, t1;
beacon_t beacon;
uuid_t uuid;
beacon_t recv;
peers_t* peers = peers_new();
struct in_addr addr;
find_my_ip(&addr, NULL);
uuid_generate(uuid);
beacon_fill(&beacon, (uint8_t*)BEACON_PROTOCOL, BEACON_VERSION, uuid, addr, htons(47473));
ufds[0].fd = udp_handle(udp);
ufds[0].events = POLLIN;
t0 = time(NULL);
t1 = time(NULL);
struct sockaddr_in sockaddr;
socklen_t si_len = sizeof(struct sockaddr_in);
while (1) {
t1 = time(NULL);
if ((long)(t1 - t0) >= PING_INTERVAL) {
ret = udp_send(udp, (uint8_t*)(&beacon), sizeof(beacon_t));
assert(ret == sizeof(beacon_t));
t0 = time(NULL);
}
ret = poll(ufds, 1, 200);
if (ret == -1) {
printf("Error: poll returned -1\n");
break;
} else if (ret == 0) {
continue;
}
if (ufds[0].revents & POLLIN) {
ret = udp_recv(udp, (uint8_t*)&recv, sizeof(beacon_t), &sockaddr, si_len);
if (ret == sizeof(beacon_t) && beacon_check(&recv, (uint8_t*)BEACON_PROTOCOL, BEACON_VERSION)) {
if (uuid_compare(uuid, recv.uuid) != 0) {
peer_t* peer = peers_exist(peers, recv.uuid);
if (!peer) {
inet_ntop(sockaddr.sin_family, &sockaddr.sin_addr, ip, INET_ADDRSTRLEN);
peer = peer_new(recv.uuid, ip, recv.port);
peers_add(peers, peer);
opts->add_peer_cb((void*)peer);
}
peer_is_alive(peer);
}
}
}
peers_check(peers);
}
peers_destroy(&peers);
udp_destroy(&udp);
return NULL;
}
