tcpdtc.c

基于UNIX的中间件编程,只能运行于UNIX操作系统

/**********************************************************
**	tcpdts.cpp:the tcp and udp global functions
**
**						zhoushijie
**
**								2000/3
**********************************************************/

#include "tcpdtc.h"

u_short portbase=0;

/*
------------------------------------------------------------------
* connectTCP---conncet to a specified tcp service on a special host
*-------------------------------------------------------------------
*/

SOCKET conncetTCP(const char *host,const char *service)
{
		return connectsock(host,service,"tcp");
}


/*
--------------------------------------------------------
* connectUDP---conncet to a specified UDP service on a special host
*-----------------------------------------------------------------
*/

SOCKET connectUDP(const char *host,const char *service)
{
		return connectsock(host,service,"udp");
}


/*
-----------------------------------------------------------
* connect sock---allocate * connect a sock using TCP Or UDP
*------------------------------------------------------------
*/

SOCKET connectsock(const char *host,const char *service,const  char *transport)
{
	struct hostent *phe;
	struct servent *pse;
	struct protoent *ppe;
	struct sockaddr_in sin;
	int s,type;

	memset(&sin,0,sizeof(sin));
	sin.sin_family=AF_INET;
	
/*map serice name to port */

	if(pse=getservbyname(service,transport))
		sin.sin_port=htons(ntohs((u_short)pse->s_port )+portbase);
	else if  ((sin.sin_port=htons((u_short)atoi(service)))==0)
			errexit("can't get \"%s\" service entry\n",service);

/* map host name to IP address,allowing for dotted decimal*/

	if (phe=gethostbyname(host))
		memcpy(&sin.sin_addr,phe->h_addr,phe->h_length);
	else if ((sin.sin_addr.s_addr=inet_addr(host))==INADDR_NONE)
		errexit("can't get\"%s\" host entry\n",host);

/*map protocol name to protocol number*/

if ((ppe=getprotobyname(transport))==0)
	errexit("can't get \" %s \" protocol entry\n",transport);

/*use protocl name to chose 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());

/*connect the socket*/
if(strcmp(transport,"tcp")==0)
	if (connect(s,(struct sockaddr *)&sin,sizeof(sin)),0)
		errexit("can't connect ot %s.%s: %d\n",host ,service,GetLastError());
return s;
}


/*---------------------------------------------
* errexit ---print an error message and exit
*----------------------------------------------
*/

void errexit(const char *format,...)
{
	va_list args;
	va_start(args,format);
	vfprintf(stderr,format,args);
	va_end(args);
	exit(1);
}



SOCKET passiveTCP(const char *host,const char *service,int qlen)
{
		return passivesock(host,service,"tcp",qlen);
}

SOCKET passiveUDP(const char *host,const char *service)
{
	return passivesock(host,service,"udp",0);
}

SOCKET passivesock(const char *host,const char *service,const char *transport,int qlen)
{
	struct servent *pse;
	struct protoent  *ppe;
	struct hostent *phe;
	struct sockaddr_in sin;
	SOCKET s;
	int  type;
	memset(&sin,0,sizeof(sin));
	sin.sin_family=AF_INET;

	/*map service name to protocol number*/
	
	if (pse=getservbyname(service,transport))
		sin.sin_port=htons(ntohs((u_short)pse->s_port )+portbase);
	else if ((sin.sin_port=htons((u_short)atoi(service)))==0)
		errexit("can't get  \"%s\" service entry\n",service);

	 /*map host name to IP address,allowing for dotted decimal*/
	if (phe=gethostbyname(host))
		memcpy(&sin.sin_addr,phe->h_addr,phe->h_length);
	else if ((sin.sin_addr.s_addr=inet_addr(host))==INADDR_NONE)
		errexit("can't get\"%s\" host entry\n",host);
	

	/* map protocol name to protocol number */
	if((ppe=getprotobyname(transport))==0)
		errexit ("cannot get  %s protocol ernty\n",transport);

/* use protocol to chose a socket type*/

if(strcmp(transport,"udp")==0)
	type=SOCK_DGRAM;
else 
	type=SOCK_STREAM;
/*allocat a socket */
s=socket(PF_INET ,type,ppe->p_proto );
if(s==INVALID_SOCKET)
	errexit("can't allocate a socket:%d",GetLastError());
/* bind a socket */
if (bind(s,(struct sockaddr *)&sin,sizeof(sin))<0)
	errexit("can't bind to %S port:%d\n",service,GetLastError());

if(type==SOCK_STREAM && listen(s,qlen)==SOCKET_ERROR)
	errexit("can't listen to %s port with error:%d\n",service ,GetLastError());
return s;
}