Fix #1: Ensure recv buf is always NUL terminated

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>
size_t pktlen(unsigned char *buf)
{
	size_t hdr = sizeof(struct udphdr);

	return strlen((char *)buf + hdr) + hdr;
}

size_t pktlen(unsigned char *buf)
{
	size_t hdr = sizeof(struct udphdr);

	return strlen((char *)buf + hdr) + hdr;
}
