[收藏]穿透代理服务器编程

天云上人

  作者 allfresh
; z. o6 G& u' Z8 N文章原始出处 www.allfresh.net/program/proxy.htm
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. ?6 f' d5 P& b6 I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
struct sock4req1
1 D9 f, v- r1 g/ D- {& f/ n{
, y0 X- e. _+ Y% S! ?+ U7 mchar VN;
( I# I; K2 z- ]1 Q; lchar CD;
unsigned short Port;
unsigned long IPAddr;
char other[1];
6 i/ |5 b  k# q5 E( h};
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struct sock4ans1
+ O$ m& x2 a' D% l. }" H5 a1 Z{
  ]( P" R: {% S0 i8 e* tchar VN;
' G2 v3 f  G# W  s' T  xchar CD;
};
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( Z" ^6 R1 J3 R* ~' I- }/ [struct sock5req1
* N, C9 z) M5 }) T5 S/ {{
char Ver;
* l+ ^5 `2 m+ x. ?+ ~% w' r6 k) `char nMethods;
char Methods[255];
$ M6 K& Y! s4 J};
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struct sock5ans1
% w- j3 I4 [. J% h: n{
" P) e- [2 f9 i" j. H' rchar Ver;
char Method;
};
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6 |8 I7 G2 e& i: Nstruct sock5req2
{
2 ]9 A7 t4 i3 f% t/ ichar Ver;
char Cmd;
char Rsv;
char Atyp;
; w6 n( K' t' p9 y8 j) J& Ochar other[1];
9 M7 z: P: @* A/ c1 t, x};
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struct sock5ans2
$ E# s- g$ `! }! g1 P{
char Ver;
# n' i; A7 ~5 f" S) qchar Rep;
char Rsv;
* W  B: q/ _) t- Bchar Atyp;
1 Z- H- U+ O* R# R5 Mchar other[1];
};
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6 L6 \1 \7 d* \( J1 f) T: n) Qstruct authreq
{
char Ver;
char Ulen;
char Name[255];
# F. m6 |3 O/ g1 ^- Uchar PLen;
char Pass[255];
};
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! t4 C6 a  o" ]struct authans
{
. I9 x/ z  Q) u  ~% @  @char Ver;
* S  J5 a' P7 g* Hchar Status;
0 e* s# F. n& R0 i8 {; Z};
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//通过Socks4方式代理
6 |/ j/ I: X) lif( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
{
% d: ^; C  u, R  sm_sError = _T("不能连接到代理服务器!");
ClientSock.Close();
) l. h. _4 v- g0 j$ R4 Dreturn FALSE;
! |( i" M4 b& h1 g, _8 {' {}
char buff[100];
+ P' j7 v# n# t* J7 hmemset(buff,0,100);
struct sock4req1 *m_proxyreq;
m_proxyreq = (struct sock4req1 *)buff;
m_proxyreq->VN = 4;
m_proxyreq->CD = 1;
m_proxyreq-&gtort = ntohs(GetPort());
m_proxyreq->IPAddr = inet_addr(GetServerHostName());
ClientSock.Send(buff,9);
struct sock4ans1 *m_proxyans;
7 w* E: x* d) R; L' s; d! Zm_proxyans = (struct sock4ans1 *)buff;
memset(buff,0,100);
  s7 w7 `, L' S. l8 c$ dClientSock.Receive(buff,100);
/ V7 ?* f7 f0 y4 _if(m_proxyans->VN != 0 || m_proxyans->CD != 90)
{
m_sError = _T("通过代理连接主站不成功!");
ClientSock.Close();
+ Z$ b/ f, ]) m& ereturn FALSE;
' `7 I3 E8 r, i( i}
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+ m# T3 o. a* O/ S
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  i( N& L  P3 ^1 R- e
) j& L. q* W( {2 r4 Z+ Y//通过Socks5方式代理
if( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
$ C; S" h/ }2 m& s" O6 V{
+ ~5 |  `1 L7 F3 w+ L$ Z. C1 O6 b# Mm_sError = _T("不能连接到代理服务器!");
2 f( O* ^0 Q, T0 p6 O  ^1 k+ vClientSock.Close();
return FALSE;
}
char buff[600];
struct sock5req1 *m_proxyreq1;
m_proxyreq1 = (struct sock5req1 *)buff;
8 V3 K" U+ x& D% Z. O8 d% Lm_proxyreq1->Ver = 5;
m_proxyreq1->nMethods = 2;
0 k" _) X5 `0 M) C+ {8 Im_proxyreq1->Methods[0] = 0;
: I$ D; ?5 {9 O; M$ f; y( Q5 em_proxyreq1->Methods[1] = 2;
5 A6 j5 k9 T5 z) l! KClientSock.Send(buff,4);
struct sock5ans1 *m_proxyans1;
# b0 i& b" j  A6 L$ ]m_proxyans1 = (struct sock5ans1 *)buff;
memset(buff,0,600);
) E0 @+ W& b/ K& h% E8 z2 J, AClientSock.Receive(buff,600);
" L, r& a4 W* n( |if(m_proxyans1->Ver != 5 || (m_proxyans1->Method!=0 && m_proxyans1->Method!=2))
) _1 p& Q2 q5 \* w' t{
1 A8 L+ K/ m2 }( a7 F1 p7 Vm_sError = _T("通过代理连接主站不成功!");
ClientSock.Close();
return FALSE;
}
9 d, H  S, d* t6 vif(m_proxyans1->Method == 2)
{
5 G0 A: x* W$ P5 sint nUserLen = strlen(g_ProxyInfo.m_strProxyUser);
3 Z) [8 F4 o2 M# i  u& x) O- Mint nPassLen = strlen(g_ProxyInfo.m_strProxyPass);
! t9 v% H9 [  k2 I& I. M$ F' Astruct authreq *m_authreq;
8 T& a0 F# e( t9 Em_authreq = (struct authreq *)buff;
m_authreq->Ver = 1;
+ ]5 L: ~9 Z" u: zm_authreq->Ulen = nUserLen;
strcpy(m_authreq->Name,g_ProxyInfo.m_strProxyUser);
- r7 G" O, v& S9 `+ \' \" Em_authreq-&gtLen = nPassLen;
strcpy(m_authreq-&gtass,g_ProxyInfo.m_strProxyPass);
ClientSock.Send(buff,513);
+ u) C( v$ [1 d; l5 o5 y, ystruct authans *m_authans;
m_authans = (struct authans *)buff;
2 O. b! z" a; xmemset(buff,0,600);
, r3 h" u# F2 }+ i- i& gClientSock.Receive(buff,600);
7 G6 @9 i5 e, \0 `if(m_authans->Ver != 1 || m_authans->Status != 0)
" {/ ^. t( K0 U9 H7 y: Y4 J7 w{
5 t* ~" T5 f' ^' d2 qm_sError = _T("代理服务器用户验证不成功!");
ClientSock.Close();
% Z8 m- I- |7 s0 Y; B5 }return FALSE;
}
}
struct sock5req2 *m_proxyreq2;
' w8 C$ v) ?0 \6 T% _! a& nm_proxyreq2 = (struct sock5req2 *)buff;
m_proxyreq2->Ver = 5;
1 g  D- f6 E2 r9 }+ z( ?m_proxyreq2->Cmd = 1;
m_proxyreq2->Rsv = 0;
, w% ~9 H- S& W/ b  um_proxyreq2->Atyp = 1;
( C8 I, G. W* |6 ~unsigned long tmpLong = inet_addr(GetServerHostName());
unsigned short port = ntohs(GetPort());
memcpy(m_proxyreq2->other,&tmpLong,4);
memcpy(m_proxyreq2->other+4,&port,2);
ClientSock.Send(buff,sizeof(struct sock5req2)+5);
struct sock5ans2 *m_proxyans2;
memset(buff,0,600);
m_proxyans2 = (struct sock5ans2 *)buff;
2 r( Q) E6 U7 {- M- P6 m: \ClientSock.Receive(buff,600);
" R4 ?0 X5 [$ V2 m; z* S0 k" N8 @if(m_proxyans2->Ver != 5 || m_proxyans2->Rep != 0)
{
  ]9 V! a- [5 J- X$ bm_sError = _T("通过代理连接主站不成功!");
ClientSock.Close();
( h6 [% H7 {% {- _0 w5 hreturn FALSE;
" ^* C% U6 l2 L7 V}
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, q6 c6 K2 D& t3 Q( a# |
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//通过HTTP方式代理
if( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
( ~2 t9 R+ r% D! C{
m_sError = _T("不能连接到代理服务器!");
ClientSock.Close();
# M6 k  F; @( r3 h9 ^; ^/ |return FALSE;
- d# e; \" K; d4 C/ N& x: r4 H7 j6 P}
' }; g- s) @; Q5 t2 m  Zchar buff[600];
sprintf( buff, "%s%s:%d%s","CONNECT ",GetServerHostName(),GetPort()," HTTP/1.1\r\nUser-Agent: MyApp/0.1\r\n\r\n");
! L6 z8 q% d. e% Q) ^ClientSock.Send(buff,strlen(buff)); //发送请求
, S0 Y: \- J. cmemset(buff,0,600);
, c) I, z. v! m0 N7 `) D( qClientSock.Receive(buff,600);
if(strstr(buff, "HTTP/1.0 200 Connection established") == NULL) //连接不成功
{
& r. R) H( J& \m_sError = _T("通过代理连接主站不成功!");
ClientSock.Close();
return FALSE;
}
2 x0 x# O( H6 m. r; V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。