www.pudn.com > Tornado_Train_Workshop_demo_program.rar > unixServer.c
/* unixServer - reads client requests and sends a reply. */
/* Copyright 1984-1994 Wind River Systems, Inc. */
/*
modification history
--------------------
01c,06apr98,dlk removed free (pClientInet).
01b,05dec94,bss cleaned up. WRS coding conventions enforced.
01a,???????,??? written.
*/
/*
DESCRIPTION
*/
/* includes */
#include <arpa/inet.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
/* defines */
#define MAX_MSG_LEN 80
#define FOREVER for (;;) /* for WRS coding conventions */
#define LOCAL static
/* typedefs */
typedef int SOCK_FD;
/* forward declarations */
LOCAL void error ();
/*******************************************************************************
*
* main - entry point to unixServer
*
* This routine sets up a UDP socket and then sits in an infinite
* loop reading client messages, printing them to the console, and
* sending a reply.
*/
main (argc, argv)
int argc;
char ** argv;
{
short port;
int clientAddrLength;
SOCK_FD sockFd;
struct sockaddr_in clientAddr;
struct sockaddr_in srvAddr;
char buf [MAX_MSG_LEN];
char * reply = "Here is your reply\n";
u_short clientPort;
char * pClientInet;
clientAddrLength = sizeof (clientAddr);
/* Get the server port number */
if (argc != 2)
{
fprintf (stderr, "Usage: >s portNumber\n", argv[0]);
exit (1);
}
port = (short) atoi (argv [1]);
/* Create a socket */
if ((sockFd = socket (PF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0)
error ("Socket failed");
/*
* Bind to a well known address. INADDR_ANY says any network
* interface will do. hton?() routines put things in network
* byte order
*/
bzero ((char *) &amt;srvAddr, sizeof (srvAddr));
srvAddr.sin_family = AF_INET;
srvAddr.sin_port = htons(port);
srvAddr.sin_addr.s_addr = INADDR_ANY;
if (bind (sockFd, &amt;srvAddr, sizeof(srvAddr)) < 0)
{
close (sockFd);
error ("Bind failed");
}
FOREVER
{
if (recvfrom (sockFd, buf, MAX_MSG_LEN, 0, &amt;clientAddr,
&amt;clientAddrLength) < 0)
{
close (sockFd);
error ("recvfrom failed");
}
clientPort = ntohs (clientAddr.sin_port);
pClientInet = inet_ntoa (clientAddr.sin_addr);
printf ("Message received from client (port = >d, inet = >s):\n",
clientPort, pClientInet);
printf (">s\n", buf);
if (sendto (sockFd, reply, strlen(reply) + 1, 0,
&amt;clientAddr, clientAddrLength) < 0)
{
close (sockFd);
error ("sendto failed");
}
}
}
/*******************************************************************************
*
* error - aborts a process on an error
*
* This funcion displays the reason a process crashed
* and terminates that process.
*/
LOCAL void error (pStr)
char * pStr;
{
perror (pStr);
exit (1);
}