[收藏]穿透代理服务器编程

天云上人

  作者 allfresh
文章原始出处 www.allfresh.net/program/proxy.htm
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正文
在网络程序设计过程中，我们经常要与各种类型的代理服务器打交道，比如在企业内部网通过代理去访问Internet网上的服务器等等，一般代理服务器支持几种常见的代理协议标准，如Socks4,Socks5,Http代理，其中Socks5需要用户验证，代理相对复杂。我在查阅RFC文档和相关资料后，特总结一些TCP协议穿透代理服务器的程序片断，希望对大家有所帮助。
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2 [: t. ^6 {) j4 E. L4 Q//使用到的结构
struct sock4req1
- Z& j# f! x; r  s5 I. d, x{
) N" F9 B% {# hchar VN;
3 i. T! H& N9 F$ [3 B9 zchar CD;
unsigned short Port;
unsigned long IPAddr;
char other[1];
, j+ K/ R; K) Q9 c};
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struct sock4ans1
0 E* ^5 h/ s3 _: J7 ^3 B6 W{
char VN;
char CD;
. p7 z1 e* y0 i4 X};
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  _6 j/ }! s; _struct sock5req1
{
& F( X% E4 M: G1 h/ h8 Y1 C8 S4 T1 uchar Ver;
char nMethods;
  m& A2 p) i, M5 k& k2 x) E4 ~char Methods[255];
6 ]# K/ x8 z$ w$ g5 E# o};
% e4 M' n. J# O3 m" ~wwww.chin aitpower.comJZM2iofLWRmFIxU68q4I3qxHU
struct sock5ans1
{
& ]' c5 m0 E) t  z  K* Nchar Ver;
char Method;
. o6 t" v+ T: N# W};
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struct sock5req2
9 r2 d7 b& w" L) Z3 \{
8 I3 Q5 |- X( @) Z5 J7 k; f: }char Ver;
, j* [+ E: E5 q( _char Cmd;
/ A/ v3 u* [' ]* Qchar Rsv;
char Atyp;
4 ]  Q& {! s- D6 r5 |: R2 p! @/ x' n8 Rchar other[1];
4 c2 E# o+ B" B' Q8 g};
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struct sock5ans2
{
char Ver;
char Rep;
. E2 d+ j- D) K: V8 r( |" Tchar Rsv;
char Atyp;
char other[1];
/ q# y# {7 y" m( S" s8 |- K- R};
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! v9 y. z7 @) E# [) {struct authreq
{
$ m( }! ?- B+ Z, W& R* ^; q1 ?0 vchar Ver;
" r4 g# c$ ?7 e  n: Bchar Ulen;
char Name[255];
char PLen;
char Pass[255];
};
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. d1 ~2 Y  A' d2 S4 Z+ g' M$ Mstruct authans
{
5 i9 |  |! e" V0 q% G# O+ mchar Ver;
3 y/ r  e7 H! z* \9 D! Z5 d; ichar Status;
' e7 I/ ]; ^# J" }3 `" w};
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//通过Socks4方式代理
if( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
2 b% L$ I# a$ O, h0 _" G{
9 Z* o) H6 I  Zm_sError = _T("不能连接到代理服务器!");
ClientSock.Close();
return FALSE;
}
, O2 e; }- E' _1 s$ wchar buff[100];
0 N' S) }( F% S! wmemset(buff,0,100);
# y: f2 n8 s, b+ fstruct sock4req1 *m_proxyreq;
m_proxyreq = (struct sock4req1 *)buff;
m_proxyreq->VN = 4;
m_proxyreq->CD = 1;
m_proxyreq-&gtort = ntohs(GetPort());
; k" e. I- X1 g4 w. S  wm_proxyreq->IPAddr = inet_addr(GetServerHostName());
" @( L' h- k- {" w9 XClientSock.Send(buff,9);
struct sock4ans1 *m_proxyans;
m_proxyans = (struct sock4ans1 *)buff;
memset(buff,0,100);
4 o  N$ |7 Y- B( u- s6 d7 M9 JClientSock.Receive(buff,100);
if(m_proxyans->VN != 0 || m_proxyans->CD != 90)
{
m_sError = _T("通过代理连接主站不成功!");
2 G. e6 [/ S- ]. j5 L5 i4 o7 EClientSock.Close();
return FALSE;
}
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//通过Socks5方式代理
if( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
8 x+ ~# [: q/ h0 e. i! j{
m_sError = _T("不能连接到代理服务器!");
3 k: e1 O0 E. P' d. X# mClientSock.Close();
return FALSE;
' Y: @( Y3 U. H& K) V}
char buff[600];
  g+ U4 P: `9 @8 ^struct sock5req1 *m_proxyreq1;
m_proxyreq1 = (struct sock5req1 *)buff;
8 k/ ]) m( a7 K7 d( Km_proxyreq1->Ver = 5;
3 h7 ]% B9 W. K8 `; \& `) ym_proxyreq1->nMethods = 2;
m_proxyreq1->Methods[0] = 0;
m_proxyreq1->Methods[1] = 2;
( A/ i, N, l3 OClientSock.Send(buff,4);
struct sock5ans1 *m_proxyans1;
m_proxyans1 = (struct sock5ans1 *)buff;
# i4 p$ P" w0 N6 N9 `+ v3 fmemset(buff,0,600);
7 B9 P6 \+ A6 B8 u4 x, B. BClientSock.Receive(buff,600);
% y& K7 e8 L( w0 I: B+ gif(m_proxyans1->Ver != 5 || (m_proxyans1->Method!=0 && m_proxyans1->Method!=2))
{
( C, N" N) ?; d( I) ?6 J. Ym_sError = _T("通过代理连接主站不成功!");
  j2 r) }$ U- I1 o$ q$ J8 p1 dClientSock.Close();
1 G0 H8 a! b. `/ p/ t) Freturn FALSE;
; i, Y2 a/ P5 N+ Z0 Z6 ~- |}
if(m_proxyans1->Method == 2)
{
% q3 s7 P: C) }9 N3 \# Xint nUserLen = strlen(g_ProxyInfo.m_strProxyUser);
5 I1 R( g* V# E( F1 \int nPassLen = strlen(g_ProxyInfo.m_strProxyPass);
struct authreq *m_authreq;
m_authreq = (struct authreq *)buff;
( d; L  V* M, v3 ?! h0 A* U$ Rm_authreq->Ver = 1;
4 Q3 n' T- ~0 z6 W. ~m_authreq->Ulen = nUserLen;
1 s8 q# ~' i4 i. L3 ^' ?7 Z7 ]strcpy(m_authreq->Name,g_ProxyInfo.m_strProxyUser);
m_authreq-&gtLen = nPassLen;
strcpy(m_authreq-&gtass,g_ProxyInfo.m_strProxyPass);
6 D0 _0 J+ ]( A2 [; VClientSock.Send(buff,513);
9 `' u* z0 M; v, Y# `  U7 ~struct authans *m_authans;
- l0 m0 B5 T3 Q+ q& V  {* Em_authans = (struct authans *)buff;
! i0 w) T) M+ V4 e) Imemset(buff,0,600);
+ T& ^0 N8 T! ^  ^. s3 bClientSock.Receive(buff,600);
if(m_authans->Ver != 1 || m_authans->Status != 0)
{
m_sError = _T("代理服务器用户验证不成功!");
ClientSock.Close();
" H, M% O/ v# y& j* }3 `* o* `" }, Treturn FALSE;
}
}
struct sock5req2 *m_proxyreq2;
m_proxyreq2 = (struct sock5req2 *)buff;
% Q' L' D4 O. Z( O) Z4 `' Gm_proxyreq2->Ver = 5;
+ n, Y) C' E* C$ {+ B3 Zm_proxyreq2->Cmd = 1;
m_proxyreq2->Rsv = 0;
m_proxyreq2->Atyp = 1;
9 T8 H7 F2 @0 }9 O& w2 A  sunsigned long tmpLong = inet_addr(GetServerHostName());
! K5 v* V; H( \unsigned short port = ntohs(GetPort());
: j8 G  p7 ^  z) Q6 `9 w7 Q/ F! Smemcpy(m_proxyreq2->other,&tmpLong,4);
0 _# x% y5 U8 d6 }memcpy(m_proxyreq2->other+4,&port,2);
ClientSock.Send(buff,sizeof(struct sock5req2)+5);
! c9 x: Z* b; {& o1 jstruct sock5ans2 *m_proxyans2;
memset(buff,0,600);
m_proxyans2 = (struct sock5ans2 *)buff;
ClientSock.Receive(buff,600);
  I* e- U  |4 _# S1 c9 \0 wif(m_proxyans2->Ver != 5 || m_proxyans2->Rep != 0)
{
m_sError = _T("通过代理连接主站不成功!");
4 ~# L& v2 c# i1 Q) {5 m, o; mClientSock.Close();
return FALSE;
9 ~# E7 m5 L, Z7 A! n}
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0 {( H. i+ e9 f! F' `
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: b5 q. r- _1 y$ |% `  \//通过HTTP方式代理
if( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
{
m_sError = _T("不能连接到代理服务器!");
ClientSock.Close();
+ a& [2 ]' r5 ~: Sreturn FALSE;
, P5 ~9 @+ o4 r. P+ Q7 Q- Z}
' P. @. {9 N6 p3 R/ S5 Nchar buff[600];
sprintf( buff, "%s%s:%d%s","CONNECT ",GetServerHostName(),GetPort()," HTTP/1.1\r\nUser-Agent: MyApp/0.1\r\n\r\n");
) l/ k3 T1 x2 l) s9 aClientSock.Send(buff,strlen(buff)); //发送请求
( L; S" m; y$ [- f  Nmemset(buff,0,600);
5 U& Z) M9 F- l. _, P: f2 ?ClientSock.Receive(buff,600);
, |( `. i/ }, ^' u* aif(strstr(buff, "HTTP/1.0 200 Connection established") == NULL) //连接不成功
{
# D2 ?+ c* ]( `' F/ G: L8 bm_sError = _T("通过代理连接主站不成功!");
2 |8 z/ u1 t; f3 {% fClientSock.Close();
return FALSE;
}
我们一般先与代理服务器连通，然后向代理服务器发送代理验证的用户名和密码(如果需要,如Socks5代理)，验证成功后，再向代理服务器发送需要连接的目的地址和端口。以上代码仅用于TCP连接，如果在内部网侦听或通过UDP协议发送信息，可查阅RFC1829等文档资料。