/* Connect to a public internet address, unconnect, then test rebinding to the
   any address port 0 and printing the remote address. */

#include "udp.h"

int main(void)
{
	int fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
	if ( fd < 0 )
		err(1, "socket");
	struct sockaddr_in sin;
	memset(&sin, 0, sizeof(sin));
	sin.sin_family = AF_INET;
	sin.sin_addr.s_addr = htobe32(BLACKHOLE_HOST);
	sin.sin_port = htobe16(BLACKHOLE_PORT);
	if ( connect(fd, (const struct sockaddr*) &sin, sizeof(sin)) < 0 )
		err(1, "first connect");
	struct sockaddr cos;
	memset(&cos, 0, sizeof(cos));
	cos.sa_family = AF_UNSPEC;
	if ( connect(fd, (const struct sockaddr*) &cos, sizeof(cos)) < 0 )
		err(1, "second connect");
	struct sockaddr_in foo;
	memset(&foo, 0, sizeof(foo));
	foo.sin_family = AF_INET;
	foo.sin_addr.s_addr = htobe32(INADDR_ANY);
	foo.sin_port = htobe16(0);
	if ( bind(fd, (const struct sockaddr*) &sin, sizeof(sin)) < 0 )
		err(1, "bind");
	struct sockaddr_in local;
	socklen_t locallen = sizeof(local);
	if ( getsockname(fd, (struct sockaddr*) &local, &locallen) < 0 )
		err(1, "getsockname");
	char host[INET_ADDRSTRLEN + 1];
	char port[5 + 1];
	getnameinfo((const struct sockaddr*) &local, locallen, host, sizeof(host),
	            port, sizeof(port), NI_NUMERICHOST | NI_NUMERICSERV);
	if ( !strncmp(host, "192.168.", strlen("192.168.")) )
		printf("192.168.1.x");
	else if ( !strncmp(host, "100.82.", strlen("100.82.")) )
		printf("192.168.1.x");
	else
		printf("%s", host);
	printf(":");
	if ( !strcmp(port, "0") )
		printf("%s", port);
	else
		printf("non-zero");
	printf("\n");
	return 0;
}