Kir: moved from the Simple TCP pair page

2013-04-12T16:57:58Z

New page

<syntaxhighlight lang="c">
#include <sys/socket.h>
#include <linux/types.h>
#include <sys/types.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <signal.h>

static int serve_new_conn(int sk)
{
int rd, wr;
char buf[1024];

printf("New connection\n");

while (1) {
rd = read(sk, buf, sizeof(buf));
if (!rd)
break;

if (rd < 0) {
perror("Can't read socket");
return 1;
}

wr = 0;
while (wr < rd) {
int w;

w = write(sk, buf + wr, rd - wr);
if (w <= 0) {
perror("Can't write socket");
return 1;
}

wr += w;
}
}

printf("Done\n");
return 0;
}

static int main_srv(int argc, char **argv)
{
int sk, port, ret;
struct sockaddr_in addr;

/*
* Let kids die themselves
*/

signal(SIGCHLD, SIG_IGN);

sk = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
if (sk < 0) {
perror("Can't create socket");
return -1;
}

port = atoi(argv[1]);
memset(&addr, 0, sizeof(addr));
addr.sin_family = AF_INET;
addr.sin_addr.s_addr = htonl(INADDR_ANY);
addr.sin_port = htons(port);

printf("Binding to port %d\n", port);

ret = bind(sk, (struct sockaddr *)&addr, sizeof(addr));
if (ret < 0) {
perror("Can't bind socket");
return -1;
}

ret = listen(sk, 16);
if (ret < 0) {
perror("Can't put sock to listen");
return -1;
}

printf("Waiting for connections\n");
while (1) {
int ask, pid;

ask = accept(sk, NULL, NULL);
if (ask < 0) {
perror("Can't accept new conn");
return -1;
}

pid = fork();
if (pid < 0) {
perror("Can't fork");
return -1;
}

if (pid > 0)
close(ask);
else {
close(sk);
ret = serve_new_conn(ask);
exit(ret);
}
}
}

static int main_cl(int argc, char **argv)
{
int sk, port, ret, val = 1, rval;
struct sockaddr_in addr;

sk = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
if (sk < 0) {
perror("Can't create socket");
return -1;
}

port = atoi(argv[2]);
printf("Connecting to %s:%d\n", argv[1], port);
memset(&addr, 0, sizeof(addr));
addr.sin_family = AF_INET;
ret = inet_aton(argv[1], &addr.sin_addr);
if (ret < 0) {
perror("Can't convert addr");
return -1;
}
addr.sin_port = htons(port);

ret = connect(sk, (struct sockaddr *)&addr, sizeof(addr));
if (ret < 0) {
perror("Can't connect");
return -1;
}

while (1) {
write(sk, &val, sizeof(val));
rval = -1;
read(sk, &rval, sizeof(rval));
printf("PP %d -> %d\n", val, rval);
sleep(2);
val++;
}
}

int main(int argc, char **argv)
{
if (argc == 2)
return main_srv(argc, argv);
else if (argc == 3)
return main_cl(argc, argv);

printf("Bad usage\n");
return 1;
}
</syntaxhighlight>

Simple TCP pair/tcp-howto.c - Revision history

Kir: moved from the Simple TCP pair page