#include	<stdio.h>
#include	<sys/types.h>
#include	<sys/socket.h>
#include	<netinet/in.h>
#include	<netdb.h>
#include	"tcpUtilities.h"



int makeConnection( char *host, int portNumber )
{
	struct hostent			*hostInfo;
	struct sockaddr_in		sin;
	int					sock;
	
  /* Set up socket address */
	bzero( (char *)(&sin), sizeof(sin) );
	sin.sin_family = AF_INET;
	sin.sin_port = htons( (u_short)portNumber );


  /* Get destination IP address using the host name. */
  /* Put address in  sin.sin_addr */

  	if( hostInfo = gethostbyname(host) )
		bcopy( hostInfo->h_addr, (char *)(&sin.sin_addr), hostInfo->h_length );
	else if( (sin.sin_addr.s_addr = inet_addr(host)) == INADDR_NONE )
		bailOut( "can't get TCP host entry\n" );


  /* Allocate a socket */
  
	sock = socket( PF_INET, SOCK_STREAM, 0 );
	if( sock < 0 )
		bailOut( "can't create socket: %s\n", sys_errlist[errno] );


  /* Connect the socket to destination address/port */
  
	if( connect( sock, (struct sockaddr *)&sin, sizeof(sin) ) < 0 )
		bailOut( "can't connect to %s.%d: %s\n", host, portNumber, sys_errlist[errno] );
	

  /* The connection is good.  Return the socket. */

	return( sock );

}

/* Modified from pp. 117-118, Comer "Internetworking with TCP/IP, VIII" */

int setUpPassiveSocket( int portNumber, int qLength )
{
	struct sockaddr_in	sin;
	int				sock;

  /* Set up the socket address */

	bzero( (char *)(&sin), sizeof(sin) );
	sin.sin_family = AF_INET;
	sin.sin_addr.s_addr = INADDR_ANY;
	sin.sin_port = (u_short)htons( portNumber );


  /* Allocate a socket */

	sock = socket( PF_INET, SOCK_STREAM, 0 );
	if( sock < 0 )
		bailOut( "can't create socket: %s\n", sys_errlist[errno] );


  /* Bind the socket and start listening */
  
	if( bind( sock, (struct sockaddr *)(&sin), sizeof(sin) ) < 0 )
		bailOut( "can't bind to %d port: %s\n", portNumber, sys_errlist[errno] );

	if( listen( sock, qLength ) < 0 )
		bailOut( "can't listen on %d port: %s\n", portNumber, sys_errlist[errno] );


  /* The socket is ready.  Caller may call accept(). */
  
	return( sock );
}

int readFromSocket( int sock, char *where, int bytesToRead )
{
	int		n, bytesToGo;

	bytesToGo = bytesToRead;
	while( bytesToGo > 0 )
	{
		n = read( sock, where, bytesToGo );
		if( n < 0 )
			return( n );  /* error: caller should handle it */
		if( n == 0 )	/* EOF */
			return( bytesToRead - bytesToGo );
		
		bytesToGo = bytesToGo - n;
		where = where + n;
	}
	return( bytesToRead - bytesToGo );
}

void getPeerHostName( int sock, char *name )
{
	struct sockaddr_in	peer;
	struct hostent		*hostInfo;
	int				failed;
	int				pSize=sizeof(peer), iSize=sizeof(struct in_addr);
	
	failed = getpeername( sock, (struct sockaddr *)&peer, &pSize );
	hostInfo = gethostbyaddr( (char *)(&peer.sin_addr), iSize, AF_INET );
	if( !failed && hostInfo )
		strcpy( name, hostInfo->h_name );
	else
		name[0] = '\0';
}

void bailOut( char *format, ... )
{
	va_list		args;
	
	va_start( args, format );
	_doprnt( format, args, stderr );
	va_end( args );
	exit(1);
}