proxy.c

来自「vxworks下的sock5代理实现,c++编写」· C语言 代码 · 共 107 行

#include "proxy.h"

int 
proxy(int argc, char ** argv)
{
	int listenfd, connfd,remotefd;
	int clilen;
	struct sockaddr_in cliaddr, servaddr, remoteaddr, bindaddr;
	struct cli_method climet;
	struct ser_method sermet;
	struct cli_req clireq;
	int recvnum, sendnum,len,maxfdp1;
	char methods[256];
	char buff[1024];
	fd_set rset;
	struct timeval tv = {100,0};

	listenfd = socket(AF_INET, SOCK_STREAM, 0);

	bzero(&servaddr, sizeof(servaddr));
	bzero(buff, sizeof(buff));
	bzero(methods, sizeof(methods));
	servaddr.sin_family = AF_INET;
	servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
	servaddr.sin_port = htons(PROXY_PORT);

	bind(listenfd, (struct sockaddr*)&servaddr, sizeof(servaddr));

	listen(listenfd, 1024);

	for(;;){
		clilen = sizeof(cliaddr);
		connfd = accept(listenfd, (struct sockaddr *)&cliaddr, &clilen);
		close(listenfd);
		recvnum = recv(connfd, &climet, sizeof(climet),0);
		if(climet.version != 5)
		{
			printf("Server only support version 5\n");
			goto err;
		}
		if(recvnum < sizeof(climet))
			goto err;
		recvnum = recv(connfd, methods, climet.nmethods, 0);
		/*printf("read %d,\n", recvnum);
		if(recvnum < climet.nmethods)
			goto err;
		*/
		sermet.version = climet.version;
		sermet.method = 0;
		
		sendnum = send(connfd, &sermet, sizeof(sermet),0);
		/* printf("write %d,\n", sendnum);
		if(sendnum < sizeof(sermet))
			goto err;
		*/	
		recvnum = recv(connfd, &clireq, sizeof(clireq),0);
		if(recvnum ==0)
			printf("read error\n");
		/*if(recvnum < sizeof(clireq))
			goto err;
		*/
		if(clireq.atyp != 1)
		{
			printf("Server only support ip V4\n");
			goto err;
		}
		remotefd = socket(AF_INET, SOCK_STREAM, 0);
		bzero(&remoteaddr, sizeof(remoteaddr));
		remoteaddr.sin_family = AF_INET;
		remoteaddr.sin_port = clireq.port;
		remoteaddr.sin_addr.s_addr = clireq.ipv4addr.s_addr;

		connect(remotefd, (struct sockaddr *)&remoteaddr, sizeof(remoteaddr));

		len = sizeof(bindaddr);
		if(getsockname(remotefd, (struct sockaddr *)&bindaddr, &len)<0)
			goto err;
		clireq.cmd = 0;

		clireq.ipv4addr.s_addr = bindaddr.sin_addr.s_addr;
		clireq.port = bindaddr.sin_port;
		
		send(connfd, &clireq, sizeof(clireq),0);

		FD_ZERO(&rset);
		for(;;){
   			FD_SET(connfd, &rset);
			FD_SET(remotefd, &rset);
			maxfdp1 = (connfd > remotefd?connfd:remotefd) +1;
			select(maxfdp1, &rset, NULL, NULL, &tv);

			if(FD_ISSET(connfd, &rset)){
				recvnum = recv(connfd, buff, sizeof(buff), 0);
				send(remotefd, buff, recvnum, 0);
			}
			else{			
				recvnum = recv(remotefd, buff, sizeof(buff), 0);
				send(connfd, buff, recvnum, 0);
			}	
		}
	}
err:
	close(connfd);
	close(listenfd);
	return 0;
}