SOCKS代理服务器
项目初衷：
时序图：
目录结构：
代码：
protocol.h
//定义了需要协商的四个协议
#pragma once
#pragma pack(1)
struct startReq//请求
{
char ver;//5
char n_methods;//方法数量
};
struct startRep//回复
{
char ver;//5
char method;
};
// VER CMD RSV ATYP DST.ADDR DST.PROT
// 1 1 X’00’ 1 Variable 2
struct addrReq
{
char ver;
char cmd;//CONNECT：X’01‘ BIND：X’02’ UDP ASSOCIATE：X’03’
char rsv;//保留
char atyp;//后面的地址类型
};
// VER REP RSV ATYP BND.ADDR BND.PORT
// 1 1 X’00’ 1 Variable 2
struct addrRep
{
char ver;
char rep;
char rsv;
char atpy;
};comm.h
服务器端和客户端共同使用的函数，客户端暂未实现
#pragma once #include <iostream> #include <sys/types.h> #include <sys/socket.h> #include <pthread.h> #include <string.h> #include <errno.h> #include <stdio.h> #define SIZE 1024 int recv_data(int sock,void* buf,size_t size); int send_data(int sock,void* buf,size_t size);
comm.cpp
#include "comm.h"
using namespace std;
int recv_data(int sock,void* buf,size_t len)
{
char* data_buf=(char*)buf;
int ret=0;
int size=len;
int left=size;
while(left){
ret=recv(sock,data_buf+size-left,left,0);
if(ret<=0){
return -1;
}
left-=ret;
}
return 0;
}
int send_data(int sock,void* buf,size_t len)
{
char* data_buf=(char*)buf;
int ret=0;
int size=len;
int left=size;
while(left){
int ret=0;
ret=send(sock,(char*)buf+size-left,left,0);
if(ret<=0){
return -1;
}
left-=ret;
}
data_buf[size-left]=‘\0‘;
return 0;
}server.cpp
#include <iostream>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <pthread.h>
#include <sys/wait.h>
#include <netdb.h>
#include <stdlib.h>
#include "protocol.h"
#include "comm.h"
#include <assert.h>
extern int h_errno;
using namespace std;
struct ThreadInfo
{
int in;
int out;
pthread_t id;
};
void proc_handler(int sock);
void* thre_handler(void* argc);
int main(int argc,char* argv[])
{
if(argc!=2){
cout<<"Usage:[proc] [port] "<<endl;
return -1;
}
int listen_sock=socket(AF_INET,SOCK_STREAM,0);
if(listen_sock<0){
perror("socket");
}
sockaddr_in local;
local.sin_family=AF_INET;
local.sin_addr.s_addr=INADDR_ANY;
//local.sin_addr.s_addr=inet_addr(argv[1]);
local.sin_port=ntohs(atoi(argv[1]));
socklen_t len=sizeof(local);
if(0!=bind(listen_sock,(sockaddr*)&local,len)){
perror("bind");
return -1;
}
if(0!=listen(listen_sock,5)){
perror("listen");
return -1;
}
int done=0;
while(!done){
sockaddr_in cli_addr;
socklen_t len;
int sock=accept(listen_sock,(sockaddr*)&cli_addr,&len);
cout<<"connection new sock:"<<inet_ntoa(cli_addr.sin_addr)<<endl;
pid_t pid1=fork();
if(pid1<0){
perror("fork");
return -1;
}else if(pid1>0){
waitpid(pid1,NULL,0);
}else{
pid_t pid2=fork();
if(pid2<0){
perror("fork");
return -1;
}else if(pid2>0){
return 0;
}else{
proc_handler(sock);
//close(sock);
return 0;
}
}
}
return 0;
}
void proc_handler(int in)//in是和客户端通信的socket
{
cout<<"proc_handler start..."<<endl;
//VER NMETHODS METHODS
// 1 1 1 to 255
startReq req;
if(0!=recv_data(in,&req,sizeof(req))){
cout<<"recv error in protocol!"<<endl;
return;
}
if(req.ver!=5 || req.n_methods<1){
cout<<"recv error in protocol!"<<endl;
return;
}
//选择methods,八位组0-255
startRep rep;
// VER METHOD
// 1 1
char methods[256];
if(req.n_methods==1){
if(0!=recv_data(in,methods,1)){
cout<<"recv error in protocol!"<<endl;
return;
}
if(methods[0]==0xFF){//FF没有可接受的方法
return;
}
else if(methods[0]==0x00){//不需要认证
rep.ver=5;
rep.method=0;
if(0!=send_data(in,&rep,sizeof(rep))){
cout<<"send error in protocol!"<<endl;
return;
}
}else{
}
}else{//选择methods
}
//接受目标server addr
// VER CMD RSV ATYP DST.ADDR DST.PROT
// 1 1 X’00’ 1 Variable 2
addrReq reqaddr;
if(0!=recv_data(in,&reqaddr,sizeof(reqaddr))){
cout<<"recv error in dstaddr!"<<endl;
return;
}
if(reqaddr.ver!=5 ||reqaddr.rsv!=0){
cout<<"recv error in dstaddr!"<<endl;
return;
}
sockaddr_in remote;
remote.sin_family=AF_INET;
if(reqaddr.atyp==1){//ipv4
cout<<"accept dst_addr ipv4"<<endl;
in_addr_t dstip;
if(0!=recv_data(in,&remote.sin_addr.s_addr,4)){
cout<<"recv error in dstaddr!"<<endl;
return;
}
}else if(reqaddr.atyp==3){//域名
cout<<"accept dst_addr domain"<<endl;
char domain[SIZE];
if(0!=recv_data(in,&domain,sizeof(domain))){
cout<<"recv error in dstaddr!"<<endl;
return;
}
cout<<"connect to domain: "<<domain<<endl;
struct hostent* ht;
if((ht=gethostbyname(domain))==NULL){
herror("gethostbyname");
return;
}
memcpy(&remote.sin_addr.s_addr,ht->h_addr_list[0],sizeof(remote.sin_addr.s_addr));//web服务端可能有多个ip，选择一个
}else{//ipv6 or error
return;
}
//获取目的port
if(0!=recv_data(in,&remote.sin_port,2)){
cout<<"recv error in dstport!"<<endl;
return;
}
cout<<"web ip: "<<inet_ntoa(remote.sin_addr)<<" web port: "<<ntohs(remote.sin_port)<<endl;
//至此获得客户端想要连接服务器的ip,port
// VER REP RSV ATYP BND.ADDR BND.PORT
// 1 1 X’00’ 1 Variable 2
addrRep repaddr;
repaddr.ver=5;
repaddr.rsv=0;//标识为RSV 的字段必须设为X’00’
int out=socket(AF_INET,SOCK_STREAM,0);
socklen_t rlen=sizeof(remote);
if(0!=connect(out,(sockaddr*)&remote,rlen)){
perror("connect");
repaddr.rep=3;//网络不可达
if(0!=send_data(in,&repaddr,sizeof(repaddr))){
cout<<"error in connect remote!"<<endl;
return;
}
}
cout<<"connect success!"<<endl;
repaddr.rep=0;//成功
repaddr.atpy=1;//ipv4
if(0!=send_data(in,&repaddr,sizeof(repaddr))){
cout<<"send error to client!"<<endl;
return;
}
struct sockaddr_in local;
socklen_t locallen=sizeof(local);
if(0!=getsockname(out,(sockaddr*)&local,&locallen)){
perror("getsockname");
return;
}
cout<<"ip: "<<inet_ntoa(local.sin_addr)<<" port: "<<ntohs(local.sin_port)<<endl;
//sleep(5);
int len=sizeof(local.sin_addr)+sizeof(local.sin_port);
if(0!=send_data(in,&local,len)){
cout<<"send error to client!"<<endl;
return;
}
cout<<"协商完成"<<endl;
///////////////////////////////////////////////////////////////////
//至此，完成了协商过程，
//以下为正式处理HTTP请求
pthread_t th1,th2;
ThreadInfo thInfo1={in,out,th2};
ThreadInfo thInfo2={out,in,th1};
pthread_create(&th1,NULL,thre_handler,&thInfo1);
pthread_create(&th2,NULL,thre_handler,&thInfo2);
}
void* thre_handler(void* argc)
{
ThreadInfo* info=(ThreadInfo*)argc;
int in=info->in;
int out=info->out;
pthread_t id=info->id;
char buf[SIZE*SIZE];
while(1){
int ret=0;
ret=recv(in,buf,sizeof(buf),0);
if(ret<=0){
perror("recv");
}
ret=send(out,buf,ret,0);
}
close(in);
close(out);
pthread_cancel(id);
return NULL;
}Makefile
.PHONY:all all:server server:server.cpp comm.cpp g++ -o $@ $^ -lpthread .PHONY:clean clean: rm -f server
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文章来自：http://lingdandan.blog.51cto.com/10697032/1839184