int main(void) {
struct UDPsopa sopa = {
.sop = NULL,
.pap = NULL,
.port = 0, // 0 = pick unused port
.packet_size = 512,
.packet_num = 0,
.host_port = 4444
};
strcpy(sopa.host_name, "127.0.0.1");
if (udp_setup(&sopa) != 0) {
udp_cleanup(&sopa);
exit(EXIT_FAILURE);
}
// additional client setup
if (SDLNet_ResolveHost(&(sopa.pap->address), sopa.host_name, sopa.host_port) != 0) {
printf("SDLNet_ResolveHost(&(sopa.pap->address), sopa.host_name, sopa.host_port) != 0\n");
printf("SDLNet_GetError() = '%s'\n", SDLNet_GetError());
udp_cleanup(&sopa);
exit(EXIT_FAILURE);
}
srand(123);
for (;;) {
sleep(1); // 1 second
sprintf((char*)sopa.pap->data, "rand_num = %d", rand());
sopa.pap->len = strlen((char*)sopa.pap->data) + 1;
const int channel = -1; // -1 = use packet's address as destination
if (SDLNet_UDP_Send(sopa.sop, channel, sopa.pap) == 0) {
printf("SDLNet_UDP_Send(sopa.sop, channel, sopa.pap) == 0\n");
printf("SDLNet_GetError() = '%s'\n", SDLNet_GetError());
udp_cleanup(&sopa);
exit(EXIT_FAILURE);
}
switch (SDLNet_UDP_Recv(sopa.sop, sopa.pap)) {
case -1:
printf("SDLNet_UDP_Recv(sopa.sop, sopa.pap) == -1\n");
printf("SDLNet_GetError() = '%s'\n", SDLNet_GetError());
udp_cleanup(&sopa);
exit(EXIT_FAILURE);
case 0:
printf("SDLNet_UDP_Recv(sopa.sop, sopa.pap) == 0 // no packets received\n");
break;
case 1:
sopa.packet_num++;
udp_print(&sopa);
break;
}
} // for(;;)
udp_cleanup(&sopa);
exit(EXIT_SUCCESS);
}
static void etherframe_print(u_char *usr, const struct pcap_pkthdr *pkt,
const u_char *d, uint16_t ethtype)
{
struct iphdr *ip;
struct tcphdr *th;
struct udphdr *uh;
uint16_t ethtype_le;
ethtype_le = ntohs(ethtype);
switch (ethtype_le) {
case ETH_P_IP:
ip = ip_hdr(d);
sb_append_str(&sb, "IP: ");
iphdr_print(ip, &sb);
switch (ip->protocol) {
case IPPROTO_TCP:
th = tcp_hdr(d + ip_hdrlen(ip));
sb_append_str(&sb, "; TCP: ");
tcp_print(th, &sb);
break;
case IPPROTO_UDP:
uh = udp_hdr(d + ip_hdrlen(ip));
sb_append_str(&sb, "; UDP: ");
udp_print(uh, &sb);
break;
default:
sb_append_char(&sb, ' ');
sb_append_str(&sb, ipproto_str(ip->protocol));
}
break;
default:
/* FIXME: This code is open to buffer overrun errors */
sb_append_str(&sb, "ether type: ");
sb.len += sprintf(sb_curr(&sb), "0x%04x ", ethtype_le);
sb_append_str(&sb, ethertype_to_str(ethtype_le));
}
}
