/*---------------------------------------------------------------
* passiveUDP - create a passive socket for use in a UDP server
*---------------------------------------------------------------
*/
SOCKET
passiveUDP(const char *service)
{
return passivesock(service, "udp", 0);
}
void errexit(const char *, ...);
u_short portbase = 0; /* port base, for test servers */
/*---------------------------------------------------------------------
* passivesock - allocate & bind a server socket using TCP or UDP
*---------------------------------------------------------------------
*/
SOCKET
passivesock(const char *service, const char *transport, int qlen)
{
struct servent *pse; /* pointer to service information entry */
struct protoent *ppe; /* pointer to protocol information entry */
struct sockaddr_in sin; /* an Internet endpoint address */
SOCKET s; /* socket descriptor */
int type; /* socket type (SOCK_STREAM, SOCK_DGRAM) */
/* Map service name to port number */
if( pse = getservbyname(service, transport) )
sin.sin_port = htons((u_short)atoi(pse->s_port) + portbase);
else if( (sin.sin_port = htos((u_short)atoi(service))) == 0 )
errexit("can't get \"%s\" service entry\n", service);
/* Map protocol name to protocol number */
if( ppe = getprotobyname(transport)) == 0 )
errexit("can't get \"%s\" protocol entry\n", transport);
/* Use protocol to choose a socket type */
if( strcmp(transport, "udp") == 0 )
type = SOCK_DGRAM;
else
type = SOCK_STREAM;
/* Allocate a socket */
s = socket(PF_INET, type, ppe->p_proto);
if( s == INVALID_SOCKET )
errexit("can't create socket: %d\n", GetLastError());
/* Bind the socket */
if( bind(s, (struct sockaddr*)&sin, sizeof(sin)) == SOCKET_ERROR)
errexit("can't bind to %s port: %d\n", service, GetLastError());
if( type == SOCK_STREAM && listen(s, qlen) == SOCKET_ERROR)
errexit("can't listen on %s port: %d\n", service, GetLastError());
#define WINEPOCH 2208988800 /* Windows epoch, in UCT secs */
#define WSVERS MAKEWORD(2, 0)
/*------------------------------------------------------------------------
* main - Iterative UDP server for TIME service
*------------------------------------------------------------------------
*/
int
main(int argc, char *argv[])
{
struct sockaddr_in fsin; /* the from address of a client */
char *service = "time"; /* service name or port number */
char buf[2048]; /* "input" buffer; any size > 1 packet */
SOCKET sock; /* server socket */
time_t now; /* current time */
int alen; /* from-address length */
WSADATA wsadata;
switch( argc )
{
case 1 : break;
case 2 : service = argv[1]; break;
default : errexit("usage" UDPtimed [port]\n");
}