socks5协议转http协议源码

socks5代理可以看rfc 1928
socks5的用户名口令认证方法看rfc 1929

http代理可以看 rfc2616
socks5代理可以支持tcp和udp 而http只支持tcp

所以这个代理转换器只支持tcp

写作原因
很多软件都有socks5认证方法 但是它们不支持http认证方法
而从原理上可以使用http认证方法(因为它们没有使用udp)
所以写这个软件可以方便的使其它程序可以使用http代理

如联众 或是foxmail

CODE

#include <winsock2.h>
#include <stdio.h>
#include <stdlib.h>
#define INIT_SOCKET(){WSADATA    wsadata;WSAStartup(MAKEWORD(2,2),&wsadata);}
#define CLOSESOCKET(x) closesocket(x)
#define CLEAN_SOCKET()   {WSACleanup();}
//   http.c   实现http代理功能

#define PROTO_EXCHANGE_TIMEOUT 15
#define PROTO_RECVRESP_TIMEOUT 75
#define PROTO_SENDRESP_TIMEOUT 10

#define WAIT_AND_RECV(sd,buf,len,waittime,recvflags)     do{/
    struct fd_set sset;/
    struct timeval waited;/
    waited.tv_sec    = waittime;waited.tv_usec    = 0;/
    FD_ZERO(&sset);FD_SET(sd,&sset);/
    if(select(sd+1,&sset,NULL,NULL,&waited) != 1 || (len = recv(sd,buf,len,recvflags)) == -1 )/
    len = -1;/
}while(0);

#define DEBUG_DUMP       printf

static int httpproxy_connect(const char*proxyaddr,int proxyport,
        const char*dstaddr,int dstport)
{
    int                  proxysd = -1;
    char                 buf[2048];
    int                  len;
    char                 *ptoken;
    int                  status;

    struct   sockaddr_in inaddr;

    if( !proxyaddr || !proxyaddr[0] || proxyport < 1
            ||!dstaddr || !dstaddr[0] )
        return -1;

    DEBUG_DUMP("代理:%s:%d,目标:%s:%d/n",proxyaddr,proxyport,dstaddr,dstport);

    len                  = sizeof(inaddr);
    memset(&inaddr,0,len);
    if( (inaddr.sin_addr.s_addr = inet_addr(proxyaddr) ) == INADDR_NONE )
        return -1;

    inaddr.sin_family     = AF_INET;
    inaddr.sin_port       = htons(proxyport);

    //   connect to proxy
    if((proxysd = socket(AF_INET,SOCK_STREAM,0)) == -1 )
        return -1;
    if( connect(proxysd,(struct sockaddr*)&inaddr,len))
        goto errorparse;

    //   发送connect请求并判断返回,根据HTTP协议说明,详细内容请看RFC2616
    //   HTTP代理使用CONNECT指令实现，CONNECT时指定选端的地址与端口号,
    //   当代理服务器返回成功后(状态值是2xx),后面的代理服务器不再对此连接的数据
    //   进行HTTP协议处理
    if( dstport > 0 )
        len = sprintf(buf,"CONNECT %s:%d HTTP/1.1/r/n/r/n",dstaddr,dstport);
    else
        len = sprintf(buf,"CONNECT %s HTTP/1.1/r/n/r/n",dstaddr);

    if( send(proxysd,buf,len,0) != len ){
        DEBUG_DUMP("发送CONNECT请求失败:包内容:%s/n",buf);
        goto errorparse;
    }

    len = sizeof(buf)-1;
    WAIT_AND_RECV(proxysd,buf,len,PROTO_RECVRESP_TIMEOUT,MSG_PEEK);
    if( len == -1){
        DEBUG_DUMP("接收CONNECT响应失败/n");
        goto errorparse;
    }

    buf[len]     = 0;
    DEBUG_DUMP("CONNECT响应为:%s|/n",buf);
    if( strnicmp(buf,"HTTP/1.",7)
            || (!strstr(buf,"/r/n/r/n") && !strstr(buf,"/n/n")))
        goto errorparse;

    ptoken   = buf;
    while(!isspace(*ptoken) && *ptoken) ptoken ++;
    status   = atoi(ptoken);
    if( status < 300 && status > 199 ){
        ptoken   = strstr(buf,"/r/n/r/n");
        if( ptoken )
            len   = ptoken - buf +4;
        else{
            ptoken = strstr(buf,"/n/n");
            len   = ptoken - buf +2;
        }
        WAIT_AND_RECV(proxysd,buf,len,PROTO_RECVRESP_TIMEOUT,0);
        return proxysd;
    }

errorparse:
    CLOSESOCKET(proxysd);
    return -1;
}

//   sd           [in]     使用socks5的客户端的连接id
//   proxyaddr    [in]     http代理地址
//   proxyport    [in]     http代理端口
//   return:
//           -1   失败
//           >=0 与http代理的连接id
static int socks5_accept(int sd,const char *proxyaddr,int proxyport)
{
    unsigned char        buf[512];
    int                  len = 2;
    int                  i    = 0;
    char                 dstaddr[260];
    int                  dstport;

    if( !proxyaddr || !proxyaddr[0] || proxyport <1 )
        return -1;

    //   处理协商,现在只处理无认证情况,无论对方会不会处理这种情况
    //   没有要求无认证方式,sorry,那我就不理它
    //   另外只处理SOCKS5的CONNECT命令,其它不处理
    WAIT_AND_RECV(sd,(char*)buf,len,PROTO_EXCHANGE_TIMEOUT,0);
    if( len != 2 || buf[0] != 5 ){
        DEBUG_DUMP("接收socks5协商包失败,len:%d,buf[0]:%d/n",len,buf[0]);
        return -1;
    }
    len = buf[1];
    i    = len;
    WAIT_AND_RECV(sd,(char*)buf,i,PROTO_EXCHANGE_TIMEOUT,0);
    if( len != i ){
        DEBUG_DUMP("接收socks5协商包失败,想接收%d,收到:%d/n",len,i);
        return -1;
    }

    for( i = 0;i< len && buf[i];i++ );

    if( i == len ){
        DEBUG_DUMP("用户没有请求socks5无认证方法:/n");
        return -1;
    }

    buf[0]   = 5;
    buf[1]   = 0;
    if( send(sd,(char*)buf,2,0) != 2)
        return -1;

    len      = 5;
    WAIT_AND_RECV(sd,(char*)buf,len,PROTO_RECVRESP_TIMEOUT,0);
    if( len != 5 || buf[0] != 5 || buf[1] != 1 ){
        DEBUG_DUMP("处理socks5CONNECT命令失败:len:%d,buf[0]:0x%x,buf[1]:0x%x/n",len,buf[0],buf[1]);
        return -1;
    }

    switch( buf[3] ){
        case 1:      //   是IP地址
            len = 5;
            WAIT_AND_RECV(sd,(char*)buf+5,len,PROTO_RECVRESP_TIMEOUT,0);
            if( len != 5 ){
                DEBUG_DUMP("处理socks5CONNECT命令[IP方式]失败:len:%d/n",len);
                return -1;
            }
            {
                struct in_addr   addr;
                memcpy((char*)&addr.s_addr,buf+4,4);
                strcpy(dstaddr,inet_ntoa(addr));
                dstport = ntohs(*(unsigned short*)(buf+8));
            }
            break;
        case 3:      //   是域方式
            len = buf[4]+2;
            WAIT_AND_RECV(sd,(char*)buf+5,len,PROTO_RECVRESP_TIMEOUT,0);
            if( len != buf[4]+2 ){
                DEBUG_DUMP("处理socks5CONNECT命令[域方式]失败:len:%d/n",len);
                return -1;
            }
            memcpy(dstaddr,buf+5,buf[4]);
            dstaddr[buf[4]] = 0;
            dstport      = ntohs(*(unsigned short*)(buf+5+buf[4]));
            break;
        default:
            DEBUG_DUMP("处理socks5CONNECT命令[]失败:未知方式:type:0x%x/n",buf[3]);
            return -1;
    }

    return httpproxy_connect(proxyaddr,proxyport,dstaddr,dstport);
}

int listenport(int port,const char*addr)
{
    int                  len = sizeof(struct sockaddr_in);
    struct sockaddr_in   bindaddr;

    int                  sd           = socket(AF_INET,SOCK_STREAM,0);
    if( sd == -1)
        return -1;

    memset(&bindaddr,0,len);
    bindaddr.sin_family              = AF_INET;
    bindaddr.sin_port                = htons(port);
    if( addr && addr[0] )
        bindaddr.sin_addr.s_addr     = inet_addr(addr);

    if( bind ( sd,(struct sockaddr*)&bindaddr,&len) || listen(sd,100 )){
        DEBUG_DUMP("打开端口失败,port:%d/n",port);
        CLOSESOCKET(sd);
        return -1;
    }

    return sd;
}

void running(int sd){
    int ad;
    if( sd == -1 )
        return;

    while(1){
        int proxyid;
        char     buf[10240];
        int      len;
        int      maxid;
        int      actcount;

        ad   = accept(sd,NULL,NULL);
        if( ad == -1 )
            break;

        DEBUG_DUMP("有客户连接,id:%d/n",ad);
        if((proxyid = socks5_accept(ad,"172.16.68.21",80)) == -1 ){
            CLOSESOCKET(ad);
            continue;
        }

        //   进行代理转发工作
        maxid    = ad > proxyid? ad:proxyid;
        while( ad > -1 ){
            struct timeval   waittime     = {10,0};
            struct fd_set    sset;
            FD_ZERO(&sset);
            FD_SET(ad,&sset);
            FD_SET(proxyid,&sset);

            actcount = select(maxid+1,&sset,NULL,NULL,&waittime);
            while(actcount > 0 ){
                int actid    = FD_ISSET(proxyid,&sset)?proxyid:ad;
                int sendid   = actid == ad? proxyid:ad;

                FD_CLR(actid,&sset);
    len = sizeof(buf)-1;
                WAIT_AND_RECV(actid,buf,len,10,0);
                if( len > 0 ){
     buf[len] = 0;
                    send(sendid,buf,len,0);
                DEBUG_DUMP("%d接口活动,内容为:%s/n",actid,buf);
    }
                else{
                    DEBUG_DUMP("接收失败,id:%d/n",actid);
                    CLOSESOCKET(ad);
                    ad   = -1;
                    break;
                }
                actcount --;
            }
        }
        //   某一方已经关闭,继续下一组转发
        CLOSESOCKET(proxyid);
    }
    CLOSESOCKET(sd);
}

main(){
    int ld;
    INIT_SOCKET();
    ld   = listenport(1080,NULL);
    if( ld != -1)
        running(ld);
    else
        DEBUG_DUMP("监听失败/n");
    CLEAN_SOCKET();
}

http及socks5代理只是在CONNECT时进行协商
后面的操作不需要附加的信息
同时代理也不会对数据进行解释 只是进行转发

这只是一个测试程序

可以自己使用httpproxy_connect与socks5_accept来实现自己的代理转换程序

另外在flashfxp上测试成功

在foxmail上还没有测试成功

主要函数说明
httpproxy_connect
通过http代理创建到目标机器的连接

socks5_accept
接收socks5连接请求,并把它转换成http代理,
创建http代理通道成功后返回http代理通道的socketid

以上两个失败都返回-1

创建成功后
客户端 <-数据-->socks5 sd <---数据--->http proxy sd<---->目标

From: http://hi.baidu.com/sorc/blog/item/555add16d2e35218962b4360.html