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/*
* tcpproxy
*
* tcpproxy is a simple tcp connection proxy which combines the
* features of rinetd and 6tunnel. tcpproxy supports IPv4 and
* IPv6 and also supports connections from IPv6 to IPv4
* endpoints and vice versa.
*
*
* Copyright (C) 2010-2015 Christian Pointner <equinox@spreadspace.org>
*
* This file is part of tcpproxy.
*
* tcpproxy is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* any later version.
*
* tcpproxy is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with tcpproxy. If not, see <http://www.gnu.org/licenses/>.
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
int main(int argc, char* argv[])
{
if(argc < 2) {
fprintf(stderr, "Usage: %s <port>\n", argv[0]);
return -1;
}
int s = socket(AF_INET, SOCK_STREAM, 0);
if(!s) {
perror("socket()");
return -1;
}
int on = 1;
int ret = setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
if(ret) {
perror("setsockopt(SO_REUSEADDR)");
return -1;
}
struct sockaddr_in laddr;
laddr.sin_family = AF_INET;
laddr.sin_port = htons(atoi(argv[1]));
laddr.sin_addr.s_addr = htonl(INADDR_ANY);
ret = bind(s, (struct sockaddr*)(&laddr), sizeof(struct sockaddr_in));
if(ret) {
perror("bind()");
return -1;
}
ret = listen(s, 1);
if(ret) {
perror("listen()");
return -1;
}
struct sockaddr_in caddr;
socklen_t len = sizeof(struct sockaddr_in);
int c = accept(s, (struct sockaddr*)(&caddr), &len);
if(c < 0) {
perror("accept()");
return -1;
}
char addr_str[64];
if(!inet_ntop(AF_INET, (&caddr.sin_addr), addr_str, sizeof(addr_str))) {
perror("inet_ntop");
return -1;
}
printf("connection from %s:%d\n", addr_str, caddr.sin_port);
char buf[10 * 1024];
for(;;) {
int nbread = recv(c, buf, sizeof(buf), 0);
if(nbread <= 0) {
if(!nbread) {
fprintf(stderr, "connection closed\n");
return 0;
} else if (errno != EAGAIN && errno != EWOULDBLOCK && errno != EINTR) {
perror("recv()");
return -1;
}
continue;
}
printf("%d bytes received\n", nbread);
int len = 0;
for(;;) {
int nbwritten = send(c, &(buf[len]), nbread - len, 0);
if(nbwritten <= 0) {
if(nbwritten < 0 && (errno != EAGAIN && errno != EWOULDBLOCK && errno != EINTR)) {
perror("send()");
return -1;
}
continue;
}
printf("%d bytes sent\n", nbwritten);
len += nbwritten;
if(len >= nbread) {
break;
}
}
}
return 0;
}
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