/* connectsock.c - connectsock */
 
#include <sys/types.h>
#include <sys/socket.h>
 
#include <netinet/in.h>
 
#include <netdb.h>
 
#ifndef INADDR_NONE
#define INADDR_NONE 0xffffffff
#endif /* INADDR_NONE */
 
u_long inet_addr();
 
/*------------------------------------------------------------------------
 * connectsock - allocate & connect a socket using TCP or UDP
 *------------------------------------------------------------------------
 */
int
connectsock( host, service, protocol )
char *host; /* name of host to which connection is desired */
char *service; /* service associated with the desired port */
char *protocol; /* name of protocol to use ("tcp" or "udp") */
{
 struct hostent *phe; /* pointer to host information entry */
 struct servent *pse; /* pointer to service information entry */
 struct protoent *ppe; /* pointer to protocol information entry*/
 struct sockaddr_in sin; /* an Internet endpoint address */
 int s, type; /* socket descriptor and socket type */
 
 
 bzero((char *)&sin, sizeof(sin));
 sin.sin_family = AF_INET;
 
 /* Map service name to port number */
 if ( pse = getservbyname(service, protocol) )
 sin.sin_port = pse->s_port;
 else if ( (sin.sin_port = htons((u_short)atoi(service))) == 0)
 {
 perror("can't get service\n");
 exit(1);
 }
 /* Map host name to IP address, allowing for dotted decimal */
 if ( phe = gethostbyname(host) )
 bcopy(phe->h_addr, (char *)&sin.sin_addr, phe->h_length);
 else if ( (sin.sin_addr.s_addr = inet_addr(host)) == INADDR_NONE ) 
 {
 perror("can't get host\n");
 exit(1);
 }
 /* Map protocol name to protocol number */
 if ( (ppe = getprotobyname(protocol)) == 0)
 {
 perror("can't get protocol\n");
 exit(1);
  }
 
 /* Use protocol to choose a socket type */
 if (strcmp(protocol, "udp") == 0)
 type = SOCK_DGRAM;
 else
 type = SOCK_STREAM;
 /* Allocate a socket */
 s = socket(PF_INET, type, ppe->p_proto);
  if (s < 0)
 {
 perror("can't create socket\n");
 exit(1);
 }
 
 /* Connect the socket */
 if (connect(s, (struct sockaddr *)&sin, sizeof(sin)) < 0)
 perror("can't connect to \n");
  return s;
}