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|
/* 05s.c */
#ifdef __cplusplus
#error Be sure you are using a C compiler...
#endif
#if defined (WIN32)
#include <winsock2.h>
#elif defined (linux)
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h> /* close */
#define INVALID_SOCKET -1
#define SOCKET_ERROR -1
#define closesocket(s) close (s)
typedef int SOCKET;
typedef struct sockaddr_in SOCKADDR_IN;
typedef struct sockaddr SOCKADDR;
#else
#error not defined for this platform
#endif
#include <stdio.h>
#include <stdlib.h>
/* macros ============================================================== */
#define TELNET 23
/* constants =========================================================== */
/* types =============================================================== */
/* structures ========================================================== */
/* private data ======================================================== */
/* private functions =================================================== */
/* ---------------------------------------------------------------------
--------------------------------------------------------------------- */
static int app (void)
{
int err = 0;
/* open a socket in TCP/IP mode. */
SOCKET sock = socket (AF_INET, SOCK_STREAM, 0);
if (sock != INVALID_SOCKET)
{
printf ("socket %d is now opened in TCP/IP mode\n", sock);
/* we want to listen on the TELNET port */
{
int sock_err;
/* assign the listening port */
SOCKADDR_IN sin =
{0};
/* automatic IP address */
sin.sin_addr.s_addr = htonl (INADDR_ANY);
/* protocol family (IP) */
sin.sin_family = AF_INET;
/* listening port */
sin.sin_port = htons (TELNET);
/* bind */
sock_err = bind (sock, (SOCKADDR *) &sin, sizeof sin);
if (sock_err != SOCKET_ERROR)
{
/* start listening (server mode) */
sock_err = listen (sock, 5);
printf ("listening on port %d...\n", TELNET);
if (sock_err != SOCKET_ERROR)
{
/* wait for a client connection */
printf ("waiting for a client connection on port %d...\n", TELNET);
{
SOCKADDR_IN csin =
{0};
int recsize = (int) sizeof csin;
SOCKET csock = accept (sock, (SOCKADDR *) & csin, &recsize);
if (csock != INVALID_SOCKET)
{
printf ("client connected with socket %d from %s:%d\n"
,csock
,inet_ntoa (csin.sin_addr)
,htons (csin.sin_port));
{
/* wait for the receive of a data block (string expected, hence + 1) */
unsigned char data[128 + 1];
sock_err = recv (csock, data, (int) sizeof data - 1, 0);
if (sock_err != SOCKET_ERROR)
{
size_t nb_rec = (size_t) sock_err;
/* convert to string */
data[nb_rec] = 0;
printf ("%u byte%s received:\n%s\n"
,(unsigned) nb_rec
,nb_rec > 1 ? "s" : ""
,data);
fflush (stdout);
/* to be continued ... */
}
else
{
perror ("socket.recv");
err = 1;
}
}
shutdown (csock, 2);
printf ("closing client socket %d...\n", csock);
closesocket (csock), csock = INVALID_SOCKET;
}
else
{
perror ("socket.accept");
err = 1;
}
}
}
else
{
perror ("socket.listen");
err = 1;
}
}
else
{
perror ("socket.bind");
err = 1;
}
printf ("closing socket %d...\n", sock);
/* close the socket. */
sock_err = closesocket (sock), sock = INVALID_SOCKET;
printf ("the socket is now closed\n");
if (sock_err)
{
perror ("socket.close");
err = 1;
}
}
}
else
{
perror ("socket.open");
err = 1;
}
return err;
}
/* entry point ========================================================= */
/* ---------------------------------------------------------------------
--------------------------------------------------------------------- */
int main (void)
{
int ret;
#if defined (WIN32)
WSADATA wsa_data;
int err = WSAStartup (MAKEWORD (2, 2), &wsa_data);
if (!err)
{
puts ("WIN: winsock2: OK");
#else
int err;
#endif
err = app ();
#if defined (WIN32)
WSACleanup ();
}
#endif
if (err)
{
ret = EXIT_FAILURE;
}
else
{
ret = EXIT_SUCCESS;
}
return ret;
} |
