void* ntp_connect(
const char* server,
int server_port,
void (*ntp_func)(uint32_t, uint32_t, uint32_t, uint32_t))
{
ntp_handle* handle;
if((handle = (ntp_handle*)malloc(sizeof(ntp_handle))) == NULL)
return NULL;
handle->receive_func = ntp_func;
handle->last_sec_sent = 0;
handle->last_nsec_sent = 0;
if((handle->sock = network_connect_udp(
server,
server_port,
NULL,
NULL)) == INVALID_SOCKET)
{
free(handle);
return NULL;
}
//printf("Unable to reach '%s:%d'\n", server, server_port);
if((handle->listener = network_listen_udp_from(
handle->sock,
ntp_listen,
handle->receive_packet,
NTP_PACKET_SIZE,
(void*)handle)) == NULL)
{
network_disconnect(handle->sock);
free(handle);
return NULL;
}
return (void*)handle;
}
int main(int argc, char *argv[])
{
dnsPacket *dns, *dnsresponse;
int iResult, iReceived;
char *qdomain, *qserver, *response;
unsigned short qtype = 1, qclass = 1;
qdomain = ((qdomain = command_arg_get(0, '-', argc, argv)) != NULL) ? qdomain : DNS_DEFAULT_LOOKUP;
qserver = ((qserver = command_arg_get(1, '-', argc, argv)) != NULL) ? qserver : DNS_LOOKUP_SERVER;
// create our empty DNS packet
dns = dns_create();
// set the required header fields
dns->base->id = DNS_IDENTIFIER;
// use recursive query?
if (command_opt_set("-r", argc, argv))
{
dns->base->flags |= DNS_FLAGS_RD;
printf("+ Using recursive querying\n");
}
// use a different query type?
if (command_opt_set("-cname", argc, argv))
{
qtype = DNS_TYPE_CNAME;
printf("+ Using CNAME query type\n");
}
else if (command_opt_set("-ns", argc, argv))
{
qtype = DNS_TYPE_NS;
printf("+ Using NS query type\n");
}
else if (command_opt_set("-mx", argc, argv))
{
qtype = DNS_TYPE_MX;
printf("+ Using MX query type\n");
}
else if (command_opt_set("-ptr", argc, argv))
{
qtype = DNS_TYPE_PTR;
printf("+ Using PTR query type\n");
}
else if (command_opt_set("-aaaa", argc, argv))
{
qtype = DNS_TYPE_AAAA;
printf("+ Using AAAA query type\n");
}
// add our question section
dns_add_question(dns, qdomain, strlen(qdomain), qtype, qclass);
dns_hton(dns);
// initialize the network
network_init(qserver, DNS_PORT);
network_connect_udp();
// send the packet out
printf("Looking up %s using %s...\n", qdomain, qserver);
iResult = network_send((char *)dns->base, dns->size);
assert(iResult > 0);
// block until a response is ready
response = network_receive(&iReceived);
assert(iReceived > 0);
// load up the response packet
dnsresponse = dns_parse(response, iReceived);
assert(dnsresponse->base->flags & DNS_FLAGS_RESPONSE && dnsresponse->base->id == DNS_IDENTIFIER);
output_print_response(dnsresponse);
output_print_sections(dnsresponse);
}
