[收藏]穿透代理服务器编程

天云上人

  作者 allfresh
2 h1 L. E6 E- L) R文章原始出处 www.allfresh.net/program/proxy.htm
% u9 X2 Y; K4 e7 D  i9 [4 swwww.chin aitpower.comJZM2iofLWRmFIxU68q4I3qxHU
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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//使用到的结构
) F! ?# n, E( T* g  {; J. t3 Hstruct sock4req1
{
char VN;
/ F$ S" y+ Z# n; H  m$ pchar CD;
unsigned short Port;
" D4 Q- L* i3 munsigned long IPAddr;
+ t! L, T% q! e1 p4 \! t/ Bchar other[1];
' v# F3 r9 ]0 B$ ]0 |};
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% i# c9 S: {" D6 `  e+ estruct sock4ans1
{
0 c4 f) m) A" u/ f* I' k; Rchar VN;
( r# `7 V) R- F8 F1 }, R- C  ichar CD;
$ P, v' ^6 r0 T0 ~- F: L. T. g( ?; g};
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1 U, h# f: Z2 d1 p1 Astruct sock5req1
{
4 ]! n- A! s. ]" Wchar Ver;
char nMethods;
char Methods[255];
};
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struct sock5ans1
{
char Ver;
3 `" K- q5 l! Q! Ychar Method;
};
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) v- D# B/ I3 h! s, r+ K2 R; c% estruct sock5req2
, V3 p' e. w, v  l{
char Ver;
char Cmd;
char Rsv;
$ o7 }  k1 K$ [  Z8 Y/ pchar Atyp;
char other[1];
};
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5 L! |$ T4 u% @; rstruct sock5ans2
2 J- x/ k( k3 W! j1 J{
char Ver;
char Rep;
char Rsv;
5 ~; P, n/ j$ O7 Gchar Atyp;
  C/ H% o9 e2 D" ~char other[1];
};
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struct authreq
{
( Q2 E3 W" T4 T, k3 c0 lchar Ver;
) @. C, e# q0 x- zchar Ulen;
* }# q' G. J4 _1 }& u/ J3 u: Hchar Name[255];
* n5 R( j$ O" ?' P0 mchar PLen;
7 y( a0 j' j! S$ Wchar Pass[255];
};
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& b. W9 z0 l4 J0 c, Fstruct authans
{
char Ver;
8 y: ]7 Z  U# P: F" K  ^. Fchar Status;
% C: z* N8 c* a) b};
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) {& O) S4 i1 }( y3 p1 h% S//通过Socks4方式代理
if( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
# c. U3 `7 d8 C. J  g1 s2 V; D{
m_sError = _T("不能连接到代理服务器!");
% s7 y! ^" ~$ A: Y# \# s8 T" {4 nClientSock.Close();
* x' W. V# P- f- T9 F- Kreturn FALSE;
}
: g/ }2 I7 p8 o, I: V2 B/ gchar buff[100];
; U" N' F; S( P7 J# xmemset(buff,0,100);
& e# d8 R+ U9 }struct sock4req1 *m_proxyreq;
m_proxyreq = (struct sock4req1 *)buff;
m_proxyreq->VN = 4;
; }  c! I3 U* um_proxyreq->CD = 1;
0 ~* b: s! g0 Q4 t  D5 mm_proxyreq-&gtort = ntohs(GetPort());
/ {( X+ ]* l7 W; |m_proxyreq->IPAddr = inet_addr(GetServerHostName());
ClientSock.Send(buff,9);
struct sock4ans1 *m_proxyans;
2 T9 c9 f: u1 ~+ Q5 g# O% ]; }m_proxyans = (struct sock4ans1 *)buff;
memset(buff,0,100);
ClientSock.Receive(buff,100);
, v% i" J, ]7 l/ g% n! [# Jif(m_proxyans->VN != 0 || m_proxyans->CD != 90)
{
m_sError = _T("通过代理连接主站不成功!");
# _: c, T+ O  z, QClientSock.Close();
return FALSE;
- u9 c, c' f5 J' l}
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" i3 D- I- B) T( X; \5 |//通过Socks5方式代理
5 Q, K8 g0 z8 F5 x/ v8 k8 i. `if( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
, g' t9 u: {& [' N% t' M+ \7 J! @{
m_sError = _T("不能连接到代理服务器!");
ClientSock.Close();
return FALSE;
* ?; y& u+ U8 ]: |8 q5 a! K}
( R& w( x9 ~( }char buff[600];
+ S: G% D7 o" q* x& J6 @* I6 fstruct sock5req1 *m_proxyreq1;
0 V7 N# G! J9 y, Dm_proxyreq1 = (struct sock5req1 *)buff;
% w% v6 x* }+ R% Tm_proxyreq1->Ver = 5;
m_proxyreq1->nMethods = 2;
m_proxyreq1->Methods[0] = 0;
m_proxyreq1->Methods[1] = 2;
  m) z- N- A( G' kClientSock.Send(buff,4);
struct sock5ans1 *m_proxyans1;
* r! b. _3 [4 a" pm_proxyans1 = (struct sock5ans1 *)buff;
memset(buff,0,600);
ClientSock.Receive(buff,600);
( G2 k5 d5 J/ Z, V( nif(m_proxyans1->Ver != 5 || (m_proxyans1->Method!=0 && m_proxyans1->Method!=2))
* Z/ ]* n4 Z* u8 g5 ^{
m_sError = _T("通过代理连接主站不成功!");
ClientSock.Close();
return FALSE;
' P, {( o( D3 A4 m, `2 Z}
7 I9 m! }2 v, [: M- Aif(m_proxyans1->Method == 2)
' Q* ~. ~. b0 i6 T4 u% D3 p& i3 F{
3 g# Q; Z: ?8 q5 r/ B! }! Mint nUserLen = strlen(g_ProxyInfo.m_strProxyUser);
) S/ j4 K3 ~  Y2 o* Hint nPassLen = strlen(g_ProxyInfo.m_strProxyPass);
. K9 e7 |4 A) ?% q4 s. k0 Wstruct authreq *m_authreq;
m_authreq = (struct authreq *)buff;
( |$ r: f: x' _$ |$ T% Rm_authreq->Ver = 1;
m_authreq->Ulen = nUserLen;
strcpy(m_authreq->Name,g_ProxyInfo.m_strProxyUser);
m_authreq-&gtLen = nPassLen;
strcpy(m_authreq-&gtass,g_ProxyInfo.m_strProxyPass);
ClientSock.Send(buff,513);
) ]: L8 r* I, _: q) j5 H) Tstruct authans *m_authans;
m_authans = (struct authans *)buff;
5 d* X: a6 }+ g3 {6 Qmemset(buff,0,600);
ClientSock.Receive(buff,600);
: v8 Y$ }2 Q& k# M; Z* K! t& ~if(m_authans->Ver != 1 || m_authans->Status != 0)
{
6 H' t. }2 v& ?9 d4 Bm_sError = _T("代理服务器用户验证不成功!");
* ]: M  j( x: s0 m/ fClientSock.Close();
return FALSE;
}
2 R9 b% t% v% x: }9 [4 W+ I}
" ?' U1 C* V' s) H. h5 e7 N- Tstruct sock5req2 *m_proxyreq2;
m_proxyreq2 = (struct sock5req2 *)buff;
( h" \5 s  P/ G( a; x$ F! Am_proxyreq2->Ver = 5;
m_proxyreq2->Cmd = 1;
8 D/ U* m+ X1 ^, vm_proxyreq2->Rsv = 0;
m_proxyreq2->Atyp = 1;
) ^) g" n7 @) b  ^% z: U6 cunsigned long tmpLong = inet_addr(GetServerHostName());
$ s3 Z$ y7 ?+ |8 B0 z+ r8 a% s' _+ Dunsigned short port = ntohs(GetPort());
3 _! E3 ?4 C  zmemcpy(m_proxyreq2->other,&tmpLong,4);
8 t; j6 x# Z" x6 Z# [memcpy(m_proxyreq2->other+4,&port,2);
ClientSock.Send(buff,sizeof(struct sock5req2)+5);
* |( t, a9 d$ L. B6 _# u6 ^% K% Qstruct sock5ans2 *m_proxyans2;
memset(buff,0,600);
1 W/ o# d4 b" e+ Cm_proxyans2 = (struct sock5ans2 *)buff;
ClientSock.Receive(buff,600);
% |& n6 ?7 m# q* q- @' s2 Sif(m_proxyans2->Ver != 5 || m_proxyans2->Rep != 0)
{
3 s' f# O9 t) l% P2 J4 \m_sError = _T("通过代理连接主站不成功!");
  l; ?4 M/ |- `  q! j; mClientSock.Close();
return FALSE;
}
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# e9 Z( Z+ L! ?; Q1 T//通过HTTP方式代理
if( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
  c3 z9 H% S# R. j: F; s" g! |{
m_sError = _T("不能连接到代理服务器!");
ClientSock.Close();
/ C- h4 Y: t: C$ E6 z$ A( Creturn FALSE;
/ I1 [& V. V  p! A$ S}
char buff[600];
sprintf( buff, "%s%s:%d%s","CONNECT ",GetServerHostName(),GetPort()," HTTP/1.1\r\nUser-Agent: MyApp/0.1\r\n\r\n");
# Q6 }0 T% e/ k$ v* c5 eClientSock.Send(buff,strlen(buff)); //发送请求
memset(buff,0,600);
ClientSock.Receive(buff,600);
if(strstr(buff, "HTTP/1.0 200 Connection established") == NULL) //连接不成功
, U4 c! U0 x* U# d$ Q3 o: |, M( J{
m_sError = _T("通过代理连接主站不成功!");
, n! \. g; u9 w% `3 d' |ClientSock.Close();
7 Q, I$ q6 b# X: ~* h$ c: J2 u- y3 Rreturn FALSE;
}
% |0 w+ h% ?5 M/ v1 C3 H  i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。