[收藏]穿透代理服务器编程

天云上人

  作者 allfresh
# _) S  c; V# a) @- [$ D4 c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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//使用到的结构
struct sock4req1
" \; E! R  e  z0 `! C{
+ N# f  Y- ]) w2 e8 v0 W* nchar VN;
; T1 o8 |* @$ Y: E$ uchar CD;
unsigned short Port;
9 \% @& }- y3 B/ \  Q3 \unsigned long IPAddr;
5 e7 ^4 A' v0 ]3 G) cchar other[1];
  R+ ]8 o) _  W) F};
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& F, B/ l. I; H6 Bstruct sock4ans1
5 p7 X% m1 h/ n  X0 b3 ~{
char VN;
char CD;
7 T8 l" [8 ?# x8 P6 f};
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struct sock5req1
/ q4 L$ ~! q! l* v  O7 }6 G( d{
1 R6 W: i  ?2 \" P( [2 J. W- f: o' Vchar Ver;
; f! U6 I. @# K2 G4 Mchar nMethods;
char Methods[255];
};
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struct sock5ans1
$ ^, E+ l! y1 v{
3 l' z! ]* n4 E- j) Uchar Ver;
- g) c8 o* [& [char Method;
( n' z0 s9 f) x};
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  }& Q6 [3 R9 t' o# A$ e& ?1 {  Rstruct sock5req2
: l+ i, \" x8 b6 l! x{
+ U2 U% P3 @" k& J1 T* U. }char Ver;
char Cmd;
& b; J7 j/ Z9 E+ L. Cchar Rsv;
& k# d  Y( r: [: Uchar Atyp;
- [  B/ Z' Q: C3 ^% B6 B( ~char other[1];
9 [  ?6 Y5 U2 r& e& K};
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: k  T+ ~5 `1 i  Istruct sock5ans2
{
' E: ?& J9 e9 D. x1 W; dchar Ver;
char Rep;
char Rsv;
char Atyp;
. A. ~  I1 t( }9 Q2 Y2 v! pchar other[1];
};
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; O7 m4 m4 o1 j) F! H. a  w1 y7 M" _7 pstruct authreq
& R6 a: a& Z7 o5 v/ E0 U{
char Ver;
char Ulen;
0 t) `/ k4 p; \& C* j5 Achar Name[255];
char PLen;
0 B9 G' }0 b& G. ^char Pass[255];
8 R3 `* o7 B. v* r};
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struct authans
{
char Ver;
char Status;
};
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, [; d/ s! Z6 C$ f5 N( X//通过Socks4方式代理
if( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
{
3 G& H. b  J0 q+ j7 @; B" Pm_sError = _T("不能连接到代理服务器!");
: B. `& K8 R+ OClientSock.Close();
' ~1 n& T# o# z: _return FALSE;
}
char buff[100];
& B0 ?" a7 K+ X4 t& t3 _1 W- L$ wmemset(buff,0,100);
) d1 @- I( y- e! `- Y* Z9 Nstruct sock4req1 *m_proxyreq;
m_proxyreq = (struct sock4req1 *)buff;
: p) R0 U* a2 h. e- Z6 z% c2 Qm_proxyreq->VN = 4;
! h6 E% a3 t& Y' Y+ R' Vm_proxyreq->CD = 1;
% O6 G. x& d% n( [9 im_proxyreq-&gtort = ntohs(GetPort());
1 u1 k1 y) C* S  ^9 ]m_proxyreq->IPAddr = inet_addr(GetServerHostName());
ClientSock.Send(buff,9);
struct sock4ans1 *m_proxyans;
9 _: V% ~- g: i7 A9 mm_proxyans = (struct sock4ans1 *)buff;
5 O% R2 p& I" xmemset(buff,0,100);
ClientSock.Receive(buff,100);
if(m_proxyans->VN != 0 || m_proxyans->CD != 90)
{
: e& W$ n* K' P( d" H/ s8 E/ vm_sError = _T("通过代理连接主站不成功!");
0 @7 V$ z7 ?" Z4 tClientSock.Close();
+ F+ M. k$ n1 y# o+ Q7 j6 N! E2 V, Oreturn FALSE;
2 j7 c; w; N8 Q5 |7 Y}
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* H- P- ]% S0 |" G; q) }
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) M+ B* r2 r. _- @5 `
! l8 Q) G# [/ S7 F( y//通过Socks5方式代理
3 {) N6 Z1 _: |2 M4 |: Uif( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
) k  j0 l, \- P1 F{
% K! j2 D' z! D' `m_sError = _T("不能连接到代理服务器!");
' E1 y* O7 f9 bClientSock.Close();
- ]8 j& |8 U2 Q6 V& t( `$ a0 wreturn FALSE;
}
& Z9 i& \1 ?3 f! i$ R) nchar buff[600];
- z( H% \0 I& I7 Wstruct sock5req1 *m_proxyreq1;
m_proxyreq1 = (struct sock5req1 *)buff;
m_proxyreq1->Ver = 5;
5 q2 M! n, M$ ^m_proxyreq1->nMethods = 2;
m_proxyreq1->Methods[0] = 0;
m_proxyreq1->Methods[1] = 2;
& C; Q. ]- S% h4 c" g0 EClientSock.Send(buff,4);
struct sock5ans1 *m_proxyans1;
( O( |7 s2 m( L. y# hm_proxyans1 = (struct sock5ans1 *)buff;
3 o4 k& d6 V' o/ _( A( p' Ymemset(buff,0,600);
" U8 L( a( j1 x. E7 {ClientSock.Receive(buff,600);
if(m_proxyans1->Ver != 5 || (m_proxyans1->Method!=0 && m_proxyans1->Method!=2))
{
7 _( d) W8 y' y( D# Nm_sError = _T("通过代理连接主站不成功!");
ClientSock.Close();
0 @3 h' b6 B& L9 k* B4 q3 M4 u- ^return FALSE;
}
if(m_proxyans1->Method == 2)
{
int nUserLen = strlen(g_ProxyInfo.m_strProxyUser);
int nPassLen = strlen(g_ProxyInfo.m_strProxyPass);
struct authreq *m_authreq;
4 d. Q$ X7 q+ P0 b9 h% [m_authreq = (struct authreq *)buff;
m_authreq->Ver = 1;
m_authreq->Ulen = nUserLen;
% ^/ i8 V. X6 X7 j4 Nstrcpy(m_authreq->Name,g_ProxyInfo.m_strProxyUser);
m_authreq-&gtLen = nPassLen;
strcpy(m_authreq-&gtass,g_ProxyInfo.m_strProxyPass);
ClientSock.Send(buff,513);
/ ~1 K% a$ ?3 l! g4 dstruct authans *m_authans;
! D8 j5 z7 G! r2 K) m1 I5 im_authans = (struct authans *)buff;
( Q- A1 g; v" E  r7 j0 ]% e. W% Smemset(buff,0,600);
ClientSock.Receive(buff,600);
9 X1 M, A; X' ^5 ]/ Z4 lif(m_authans->Ver != 1 || m_authans->Status != 0)
2 n( N1 M  [: G9 p{
m_sError = _T("代理服务器用户验证不成功!");
ClientSock.Close();
return FALSE;
}
% N' J) r$ Y' X: b; M4 I1 h}
8 ?+ x6 R7 @. E& h/ Zstruct sock5req2 *m_proxyreq2;
, \! o& k! a7 D0 E  Nm_proxyreq2 = (struct sock5req2 *)buff;
m_proxyreq2->Ver = 5;
6 R2 d# O1 A1 z) t" \/ Lm_proxyreq2->Cmd = 1;
$ S0 G' v7 A1 g8 tm_proxyreq2->Rsv = 0;
m_proxyreq2->Atyp = 1;
2 n: p$ ^. j0 H+ @2 Tunsigned long tmpLong = inet_addr(GetServerHostName());
unsigned short port = ntohs(GetPort());
7 i% Q+ Y, Z- O5 ~memcpy(m_proxyreq2->other,&tmpLong,4);
memcpy(m_proxyreq2->other+4,&port,2);
3 G. U. K' _1 [$ rClientSock.Send(buff,sizeof(struct sock5req2)+5);
9 n: T3 @+ z( a8 c" v0 Fstruct sock5ans2 *m_proxyans2;
; n# \& A- H, H4 z$ dmemset(buff,0,600);
" X* f; ~, S2 f% a- |, ym_proxyans2 = (struct sock5ans2 *)buff;
ClientSock.Receive(buff,600);
if(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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2 s9 D; L. ]* T! ~
& f: C- ?* _4 b8 I6 n* v4 x//通过HTTP方式代理
  Z) p. {( Y) k2 i7 Kif( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
9 r( C8 }5 U3 ]  J{
m_sError = _T("不能连接到代理服务器!");
ClientSock.Close();
: p! ~' V! N& g" l; W$ j9 sreturn FALSE;
- w% I% H8 c' r7 A* q6 d: c}
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");
ClientSock.Send(buff,strlen(buff)); //发送请求
memset(buff,0,600);
ClientSock.Receive(buff,600);
& Q( [: E5 y9 W4 C2 {5 E+ d, u9 ]if(strstr(buff, "HTTP/1.0 200 Connection established") == NULL) //连接不成功
; n4 F' P- q( n. D- k, p{
; R$ A8 g0 {5 \0 t3 X2 C: hm_sError = _T("通过代理连接主站不成功!");
ClientSock.Close();
return FALSE;
% B- m/ y7 {# k0 M}
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。