[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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7 h1 P+ S# R5 Y' X正文
4 M( m, K9 r3 ?, S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
5 ]9 p' u; ]+ X& w2 vstruct sock4req1
1 {; @7 ?$ e* m) ~; g5 i: ?& Z% H{
) s% R  o$ }" N. Dchar VN;
: {$ `5 H8 p. B2 Dchar CD;
2 v: Q8 `7 [7 Z- \unsigned short Port;
unsigned long IPAddr;
) U, c3 p" J- Q2 X, z/ i) A& wchar other[1];
};
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struct sock4ans1
{
char VN;
1 E; y0 H, r" X2 b% R, zchar CD;
};
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" ^$ m2 Y; t9 b. W1 Istruct sock5req1
' Y4 Q$ y, m/ p5 J; `{
9 X6 g1 T" A1 D! d0 G. l0 z8 ichar Ver;
char nMethods;
+ }8 y) `$ S( N0 nchar Methods[255];
6 ^* l- d- G  N};
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" L! Y4 H. b$ B( X/ R. n' _* B1 estruct sock5ans1
6 p6 c2 O8 ~' V  ^1 ~{
; |* S$ x. S  p: j' O& Echar Ver;
5 Q- O* W8 ~9 s* @char Method;
! T9 c0 f( B+ z  i! g$ t9 O};
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struct sock5req2
+ T$ |  W! v: ^" I' ?3 R' l; N2 r{
. o/ x5 O3 C' H% L: S1 }char Ver;
char Cmd;
' i& f7 \; q- \; @6 U* p2 X1 u" ~char Rsv;
char Atyp;
& g  r; b8 r" ^: c, Vchar other[1];
};
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struct sock5ans2
3 F/ v$ L% E( Q4 c( l{
4 H. I0 N# v1 k& Z. m0 y6 ?char Ver;
char Rep;
( n- s- ]/ ?, l5 R' w8 tchar Rsv;
( R. Z- @6 \7 E" }  R* R! achar Atyp;
char other[1];
};
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5 I" |% C# |" L6 N) J- s4 e  A9 ^6 t: |struct authreq
{
char Ver;
char Ulen;
char Name[255];
char PLen;
char Pass[255];
. v3 Y8 n* b4 a. J" b};
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2 _6 [5 t9 `( G7 A( c1 Wstruct authans
9 {% q& W3 ]) [: T0 J& [' b{
& p& b, X. Y& U! J) e  I1 z" W: |char Ver;
6 _3 v# k0 T* D3 c7 }char Status;
7 \+ Y6 m% Q; U* T. \6 J};
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//通过Socks4方式代理
6 q+ N. A" [0 I5 f. i0 eif( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
: B& o9 f5 t- `$ e$ L, u{
m_sError = _T("不能连接到代理服务器!");
( W- C. ^# G( eClientSock.Close();
return FALSE;
}
char buff[100];
memset(buff,0,100);
" F# R' i# _/ P  l! s$ {struct sock4req1 *m_proxyreq;
m_proxyreq = (struct sock4req1 *)buff;
. x* C2 F! @/ ?% Xm_proxyreq->VN = 4;
3 x' o0 u7 E: b; S1 G4 l+ km_proxyreq->CD = 1;
m_proxyreq-&gtort = ntohs(GetPort());
m_proxyreq->IPAddr = inet_addr(GetServerHostName());
( s1 e! E6 s- Q+ n: Y: d) XClientSock.Send(buff,9);
struct sock4ans1 *m_proxyans;
m_proxyans = (struct sock4ans1 *)buff;
memset(buff,0,100);
ClientSock.Receive(buff,100);
3 k: I, i5 N. Mif(m_proxyans->VN != 0 || m_proxyans->CD != 90)
{
m_sError = _T("通过代理连接主站不成功!");
' K& }1 E9 }% K6 fClientSock.Close();
return FALSE;
) e3 y3 Y1 H* m) W- k. h}
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3 A- B6 U% o8 c$ V/ k# Q
/ Y) B# ~1 }0 [/ k//通过Socks5方式代理
# i/ }3 R2 m1 m8 _: O, M) r7 Kif( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
{
- R' U" S; ~6 k/ s1 M( lm_sError = _T("不能连接到代理服务器!");
ClientSock.Close();
return FALSE;
6 l1 d3 f/ A7 M8 E# I- m}
4 }4 s+ v' Y" ichar buff[600];
& [; z0 X  {4 O7 g/ i$ Q  V! {struct sock5req1 *m_proxyreq1;
1 D/ ]! b6 M- Lm_proxyreq1 = (struct sock5req1 *)buff;
m_proxyreq1->Ver = 5;
m_proxyreq1->nMethods = 2;
m_proxyreq1->Methods[0] = 0;
- x5 Q+ T/ [! j  N+ ~" Wm_proxyreq1->Methods[1] = 2;
& x2 c# N  ^; hClientSock.Send(buff,4);
9 ^4 M; n5 Y  N3 ?+ pstruct sock5ans1 *m_proxyans1;
m_proxyans1 = (struct sock5ans1 *)buff;
2 G( k% @- a8 a/ ?2 |8 \memset(buff,0,600);
ClientSock.Receive(buff,600);
if(m_proxyans1->Ver != 5 || (m_proxyans1->Method!=0 && m_proxyans1->Method!=2))
. C. a) f! m6 F$ h1 z* @" E# `{
m_sError = _T("通过代理连接主站不成功!");
ClientSock.Close();
6 Z( _4 e# v4 z; }% u" e3 ireturn FALSE;
}
if(m_proxyans1->Method == 2)
{
int nUserLen = strlen(g_ProxyInfo.m_strProxyUser);
& |* h5 S" z; oint nPassLen = strlen(g_ProxyInfo.m_strProxyPass);
- x4 Q1 P1 p( Cstruct authreq *m_authreq;
m_authreq = (struct authreq *)buff;
m_authreq->Ver = 1;
3 w  p7 b3 T( L" V2 Gm_authreq->Ulen = nUserLen;
strcpy(m_authreq->Name,g_ProxyInfo.m_strProxyUser);
& z# {# l8 o6 I* [m_authreq-&gtLen = nPassLen;
& g$ a( T* H2 ?8 I) A; ?strcpy(m_authreq-&gtass,g_ProxyInfo.m_strProxyPass);
  L, H, Q& ~' S/ a) I( jClientSock.Send(buff,513);
struct authans *m_authans;
m_authans = (struct authans *)buff;
memset(buff,0,600);
. b  L5 W* J# |- x1 lClientSock.Receive(buff,600);
if(m_authans->Ver != 1 || m_authans->Status != 0)
9 [, ^. ]7 r2 d! x4 x0 E8 H{
m_sError = _T("代理服务器用户验证不成功!");
+ a( s% s, C) Z0 V% jClientSock.Close();
' ~" j1 M6 [0 U) Oreturn FALSE;
}
}
! q1 z) @- E& c% V# pstruct sock5req2 *m_proxyreq2;
; z1 U3 }% ~4 t, M3 A3 C+ Sm_proxyreq2 = (struct sock5req2 *)buff;
m_proxyreq2->Ver = 5;
! W7 a: N" |: F& a! [m_proxyreq2->Cmd = 1;
7 I% E) O, I; w: J% ~4 mm_proxyreq2->Rsv = 0;
; |+ K2 B& y9 k0 n0 o+ dm_proxyreq2->Atyp = 1;
unsigned long tmpLong = inet_addr(GetServerHostName());
unsigned short port = ntohs(GetPort());
: [. d" P9 J3 @7 `memcpy(m_proxyreq2->other,&tmpLong,4);
memcpy(m_proxyreq2->other+4,&port,2);
ClientSock.Send(buff,sizeof(struct sock5req2)+5);
struct sock5ans2 *m_proxyans2;
& h; O8 _* l# }memset(buff,0,600);
& R* z( }/ G1 N. V, o: X& h4 mm_proxyans2 = (struct sock5ans2 *)buff;
# S2 ^9 c" n+ t+ q" B5 e& y( eClientSock.Receive(buff,600);
& ~4 l, b: U! l+ Aif(m_proxyans2->Ver != 5 || m_proxyans2->Rep != 0)
{
m_sError = _T("通过代理连接主站不成功!");
ClientSock.Close();
return FALSE;
}
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- n) B2 j, T! k8 B//通过HTTP方式代理
. R- E% @: ^' ]( Z' V3 i4 j; lif( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
# z5 f2 a2 ?& ^- W" \3 b{
- x$ D4 x; I% G% ^0 T' Xm_sError = _T("不能连接到代理服务器!");
: |4 ]/ H, M1 ^0 O7 X; P# S# lClientSock.Close();
7 p; h6 y, ^/ c$ `* q0 l, Wreturn FALSE;
# K" n# E  e0 @}
, F& ?3 u+ ?" R6 r$ ]; cchar buff[600];
sprintf( buff, "%s%s:%d%s","CONNECT ",GetServerHostName(),GetPort()," HTTP/1.1\r\nUser-Agent: MyApp/0.1\r\n\r\n");
! U% M. q- E& ^  X0 pClientSock.Send(buff,strlen(buff)); //发送请求
. w5 J& \1 I/ \& C0 ~memset(buff,0,600);
2 f7 P/ _# T+ u9 }2 h9 T3 S/ ZClientSock.Receive(buff,600);
0 r7 m5 N) e7 @4 {if(strstr(buff, "HTTP/1.0 200 Connection established") == NULL) //连接不成功
{
m_sError = _T("通过代理连接主站不成功!");
ClientSock.Close();
return FALSE;
1 r0 w: i9 j( K3 `( X}
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。