tcprelay.c

linux下的tcpreplay源代码

/* tcprelay v1.0 by  [e-mail] 2004.12.19
	http://www.ustc.edu.cn/~james/tcprelay/

*/

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/ip.h>
#include <netinet/tcp.h>
#include <linux/if.h>
#include <linux/if_ether.h>
#include <linux/if_packet.h>
#include "sock.h"

#define MAXLEN 16384

// #define DEBUG 1

char *laddr,*lport,*raddr,*rport;
unsigned long fwd,rfwd;
int r_fd, c_fd;
char scaddr[MAXLEN],sladdr[MAXLEN],sraddr[MAXLEN],srcaddr[MAXLEN];

char * PrintAddr(struct sockaddr *sa)
{
	struct sockaddr_in *sa_in;
	struct sockaddr_in6 *sa_in6;
	static char buf[MAXLEN];
	char buf2[MAXLEN];

	if(sa->sa_family==AF_INET) {
		sa_in = (struct sockaddr_in*)sa;
		snprintf(buf,MAXLEN,"%s:%d",
			inet_ntop(sa_in->sin_family,&sa_in->sin_addr,buf2,MAXLEN),
			ntohs(sa_in->sin_port));
	} else if(sa->sa_family==AF_INET6) {
		sa_in6 = (struct sockaddr_in6 *)sa;
		snprintf(buf,MAXLEN,"%s:%d",
			inet_ntop(sa_in6->sin6_family,&sa_in6->sin6_addr,buf2,MAXLEN),
			ntohs(sa_in6->sin6_port));
	} else snprintf(buf,MAXLEN,"unknow family %d",sa->sa_family);
	return buf;
}

void PrintStats(void)
{
	syslog(LOG_INFO,"%s->%s ",scaddr,sladdr);
	syslog(LOG_INFO,"==> %s->%s\n",srcaddr,sraddr);
	syslog(LOG_INFO,"===> %8lu bytes\n",fwd);
	syslog(LOG_INFO,"<=== %8lu bytes\n",rfwd);

}

void Process(int c_fd) 
{	
	fd_set rset;
	struct timeval tv;
	char buffer[MAXLEN];
	int m,n;
	int max_fd;
	struct sockaddr_in6 sa;
	int salen;
	fwd=rfwd=0;	

	r_fd= Tcp_connect(raddr,rport);
	
	scaddr[0]=sladdr[0]=sraddr[0]=srcaddr[0]=0;
	salen=sizeof(sa);
	if(getpeername(c_fd,(struct sockaddr*)&sa,&salen)==0) 
		strncpy(scaddr,PrintAddr((struct sockaddr*)&sa),MAXLEN);
	salen=sizeof(sa);
	if(getsockname(c_fd,(struct sockaddr*)&sa,&salen)==0) 
		strncpy(sladdr,PrintAddr((struct sockaddr*)&sa),MAXLEN);
	
	salen=sizeof(sa);
	if(getpeername(r_fd,(struct sockaddr*)&sa,&salen)==0) 
		strncpy(sraddr,PrintAddr((struct sockaddr*)&sa),MAXLEN);
	salen=sizeof(sa);
	if(getsockname(r_fd,(struct sockaddr*)&sa,&salen)==0) 
		strncpy(srcaddr,PrintAddr((struct sockaddr*)&sa),MAXLEN);

	while (1) {
		FD_ZERO(&rset);
		FD_SET(c_fd, &rset);
		FD_SET(r_fd, &rset);
		max_fd = max(c_fd,r_fd);
		tv.tv_sec = 300;
		tv.tv_usec = 0;

		m = Select (max_fd + 1, &rset, NULL, NULL, &tv);

		if (m == 0) 
			continue;
		
		if (FD_ISSET(r_fd, &rset)) {
			n = recv (r_fd, buffer, MAXLEN,0);
			if(n<=0)   {
				PrintStats();
				exit(0);
			}
			Write(c_fd, buffer, n);
			rfwd+=n;
		}	
		if (FD_ISSET(c_fd, &rset)) {
			n = recv (c_fd, buffer, MAXLEN,0);
			if(n<=0)   {
				PrintStats();
				exit(0);		
			}
			Write(r_fd, buffer, n);
			fwd+=n;
		}
	}
}

void usage()
{
	printf("\ntcprelay v1.0 - tcp relay by [e-mail]\n");
	printf("\n      http://www.ustc.edu.cn/~james/tcprelay\n");
	printf("\ntcprelay local_address local_port remote_address remote_port\n\n");
	exit(0);
}

int main(int argc, char *argv[])
{
	int listen_fd;
	int llen;

	signal(SIGCHLD,SIG_IGN);
	if(argc!=5) 
		usage();

	laddr=argv[1]; lport=argv[2];
	raddr=argv[3]; rport=argv[4];
	printf("tcprelay %s:%s -> %s:%s\n", laddr,lport,raddr,rport);

#ifndef DEBUG
	daemon_init("tcprelay",LOG_DAEMON);
#endif

	listen_fd = Tcp_listen(laddr,lport,&llen);

	while (1) {
		struct sockaddr sa; int slen;
		slen = sizeof(sa);
		c_fd = Accept(listen_fd, &sa, & slen);
#ifdef DEBUG
			Process(c_fd);
#else
		if( Fork()==0 ) {
			Close(listen_fd);
			Process(c_fd);
		}
#endif
		Close(c_fd);
	}
}