/* Bind to the any address port 0 and test if binding to AF_UNSPEC unbinds the socket. */ #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(INADDR_ANY); sin.sin_port = htobe16(0); if ( bind(fd, (const struct sockaddr*) &sin, sizeof(sin)) < 0 ) err(1, "bind"); struct sockaddr_in cos; memset(&cos, 0, sizeof(cos)); cos.sin_family = AF_UNSPEC; if ( bind(fd, (const struct sockaddr*) &cos, sizeof(cos)) < 0 ) err(1, "bind AF_UNSPEC"); return 0; }