In a vSockets application, obtain the new address family (domain) to replace AF_INET.

int afVMCI = VMCISock_GetAFValue();
if ((sockfd = socket(afVMCI, SOCK_STREAM, 0)) == -1) {
      perror("socket");
      goto cleanup;
}

VMCISock_GetAFValue() returns a descriptor for the vSockets address family if available.