/*************************************************************************//*                                                                       *//*                  Language Technologies Institute                      *//*                     Carnegie Mellon University                        *//*                        Copyright (c) 2000                             *//*                        All Rights Reserved.                           *//*                                                                       *//*  Permission is hereby granted, free of charge, to use and distribute  *//*  this software and its documentation without restriction, including   *//*  without limitation the rights to use, copy, modify, merge, publish,  *//*  distribute, sublicense, and/or sell copies of this work, and to      *//*  permit persons to whom this work is furnished to do so, subject to   *//*  the following conditions:                                            *//*   1. The code must retain the above copyright notice, this list of    *//*      conditions and the following disclaimer.                         *//*   2. Any modifications must be clearly marked as such.                *//*   3. Original authors' names are not deleted.                         *//*   4. The authors' names are not used to endorse or promote products   *//*      derived from this software without specific prior written        *//*      permission.                                                      *//*                                                                       *//*  CARNEGIE MELLON UNIVERSITY AND THE CONTRIBUTORS TO THIS WORK         *//*  DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING      *//*  ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT   *//*  SHALL CARNEGIE MELLON UNIVERSITY NOR THE CONTRIBUTORS BE LIABLE      *//*  FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES    *//*  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN   *//*  AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,          *//*  ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF       *//*  THIS SOFTWARE.                                                       *//*                                                                       *//*************************************************************************//*             Author:  Alan W Black (awb@cs.cmu.edu)                    *//*               Date:  October 2000                                     *//*************************************************************************//*                                                                       *//*  Some generic socket client/server code                               *//*                                                                       *//*************************************************************************/#ifdef CST_NO_SOCKETS int cst_socket_open(const char *host, int port){    (void)host;    (void)port;    return -1;} int cst_socket_server(const char *name, int port,		      int (process_client)(int name,int fd)){    (void)name;    (void)port;    (void)process_client;    return -1;} int cst_socket_close(int socket){    return -1;}#else#include <stdio.h>#include <stdlib.h>#ifndef _MSC_VER#include <unistd.h>#endif#include <string.h>#include <sys/types.h>#ifndef _MSC_VER#include <sys/socket.h>#include <netdb.h>#include <netinet/in.h>#include <arpa/inet.h>#else#include <io.h>#include <WinSock2.h>#pragma comment(lib, "Ws2_32.lib")#endif#include "cst_socket.h"#include "cst_error.h" int cst_socket_open(const char *host, int port){    /* Return an FD to a remote server */    struct sockaddr_in serv_addr;    struct hostent *serverhost;    int fd;     fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);     if (fd < 0)    {	cst_errmsg("cst_socket: can't get socket\n");	return -1;    }    memset(&serv_addr, 0, sizeof(serv_addr));    if ((serv_addr.sin_addr.s_addr = inet_addr(host)) == INADDR_NONE)    {	/* its a name rather than an ipnum */	serverhost = gethostbyname(host);	if (serverhost == (struct hostent *)0)	{	    cst_errmsg("cst_socket: gethostbyname failed\n");	    return -1;	}	memmove(&serv_addr.sin_addr,serverhost->h_addr, serverhost->h_length);    }    serv_addr.sin_family = AF_INET;    serv_addr.sin_port = htons(port);     if (connect(fd, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) != 0)    {	cst_errmsg("cst_socket: connect to server failed\n");	return -1;    }     return fd;} int cst_socket_close(int socket){    return close(socket);} int cst_socket_server(const char *name, int port,		      int (process_client)(int name,int fd)){    struct sockaddr_in serv_addr;    int fd, fd1;    int client_name = 0;    int one = 1;     fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);     if (fd < 0)    {	cst_errmsg("can't open socket %d\n",port);	return -1;    }     if (setsockopt(fd, SOL_SOCKET,SO_REUSEADDR,(char *)&one,sizeof(int)) < 0)    {	cst_errmsg("socket SO_REUSERADDR failed\n");	return -1;     }     memset(&serv_addr, 0, sizeof(serv_addr));    serv_addr.sin_family = AF_INET;    serv_addr.sin_port = htons(port);    serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);     if (bind(fd, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) != 0)    {	cst_errmsg("socket: bind failed\n");	return -1;    }     if (listen(fd, 5) != 0)    {	cst_errmsg("socket: listen failed\n");	return -1;    }     if (name)	printf("server (%s) started on port %d\n",name, port);     while(1)                          /* never exits except by signals */    {	if((fd1 = accept(fd, 0, 0)) < 0)	{	    cst_errmsg("socket: accept failed\n");	    return -1;	} 	client_name++; 	(process_client)(client_name,fd1); 	close(fd1);    }     return 0;} #endif