[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
* J5 k2 V. G3 {: f# ]( 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
9 W/ |3 Y: B( L. Ystruct sock4req1
2 i/ s  `% Q# z( y5 g5 i1 U{
char VN;
char CD;
8 z4 `  V" m0 V. ~unsigned short Port;
unsigned long IPAddr;
char other[1];
/ T: E- h+ N; R& Y};
wwww.chin aitpower.comJZM2iofLWRmFIxU68q4I3qxHU
+ J$ @% l7 O  V* d: B- g2 f2 J& Estruct sock4ans1
$ X; E# [/ a) l8 ^{
char VN;
char CD;
};
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2 x4 |2 d9 ]. m$ @! O! Vstruct sock5req1
{
char Ver;
char nMethods;
* y  e+ B5 h* w# W( Y4 fchar Methods[255];
};
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3 V5 H; R$ U, h: U/ o( Q/ Gstruct sock5ans1
{
char Ver;
8 d3 _) o; t' ~1 Ochar Method;
* m. A& X" \1 k, O- z};
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struct sock5req2
1 v5 f; Q/ C) f/ R{
6 M, ^' C' p$ O  M3 T6 kchar Ver;
8 s3 @: B! z: Y7 F& S3 a" dchar Cmd;
. J2 |: N4 y1 F$ schar Rsv;
6 x- z' T2 q: ?char Atyp;
char other[1];
% t; d. F5 U1 a* s6 K! C};
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struct sock5ans2
{
- W0 }8 C$ q$ m9 Ichar Ver;
1 {5 I/ l8 n6 v- O# J3 ochar Rep;
7 n; @* E" }( _$ a6 R( N" d- A# W4 achar Rsv;
char Atyp;
  x. G' x# b. U3 R* mchar other[1];
};
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struct authreq
& \- a$ r; L" y( ]{
char Ver;
& o* i. g  k' U& u+ c/ Z. i7 nchar Ulen;
char Name[255];
char PLen;
, [; N" g7 s3 Y# Fchar Pass[255];
9 j$ i' Q9 k" E5 C9 \9 z};
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  {  C2 O; G2 z+ S9 A+ Kstruct authans
{
" l5 v8 m; T( B- u9 }' ]+ [) D7 Uchar Ver;
char Status;
: F3 A4 s6 q+ G  S' J6 m: Q};
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//通过Socks4方式代理
* {7 ]4 N& B: i( O; S) n, Qif( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
{
m_sError = _T("不能连接到代理服务器!");
5 \  _: Z2 |9 b5 h$ ]ClientSock.Close();
( c1 ?" M5 M4 _8 I" s" Lreturn FALSE;
3 \! P1 G8 f& ?( g+ H; l}
char buff[100];
2 k  y; B. P  N0 \memset(buff,0,100);
3 N4 y! V6 i0 B# Z! j  Ostruct sock4req1 *m_proxyreq;
m_proxyreq = (struct sock4req1 *)buff;
4 M* S' Y$ [& E/ O/ ?% Om_proxyreq->VN = 4;
$ }; h3 G4 t2 l3 T0 rm_proxyreq->CD = 1;
m_proxyreq-&gtort = ntohs(GetPort());
m_proxyreq->IPAddr = inet_addr(GetServerHostName());
ClientSock.Send(buff,9);
9 O- J+ V- |, [2 Y) d3 gstruct sock4ans1 *m_proxyans;
4 r' f4 F7 Z5 t3 f: g% J# {$ L% |. Fm_proxyans = (struct sock4ans1 *)buff;
" {+ D# `4 m# f7 q) M6 zmemset(buff,0,100);
! e. [, ^: ^; ~# @, y4 nClientSock.Receive(buff,100);
7 B" f8 `! J5 J2 B+ Aif(m_proxyans->VN != 0 || m_proxyans->CD != 90)
, D( k; m2 E4 u& n: \8 Y- |{
1 _3 p# l5 Z- ^- m) ym_sError = _T("通过代理连接主站不成功!");
% @; @1 N% ?; I6 r$ }- X& }8 ?: |ClientSock.Close();
% ~: r: F6 g" L* H0 y+ o" A; hreturn FALSE;
}
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" m/ X" I; |( V. O! ?+ a
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8 J% |" \3 {* m8 x/ Q) o
//通过Socks5方式代理
1 ?) X# X" S! `0 k' {if( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
5 v$ g# |; u$ q{
( M# Z: r  O8 }9 W+ Vm_sError = _T("不能连接到代理服务器!");
+ P0 l2 ?+ f8 z! YClientSock.Close();
return FALSE;
$ |) `' i3 Q3 F$ T/ `}
3 M- M% `5 I* B1 ^6 J/ ?) rchar buff[600];
. `% `' G, G/ a& Vstruct sock5req1 *m_proxyreq1;
; [4 q  }) B1 p" @6 Zm_proxyreq1 = (struct sock5req1 *)buff;
; ]0 d% z: g& S' ^0 i3 em_proxyreq1->Ver = 5;
m_proxyreq1->nMethods = 2;
: y2 c$ U: b5 K! k: c+ J  `) B" C( n' sm_proxyreq1->Methods[0] = 0;
m_proxyreq1->Methods[1] = 2;
! I% P+ b& Y& e8 a7 TClientSock.Send(buff,4);
4 W' ^. y# f7 m6 k, xstruct sock5ans1 *m_proxyans1;
4 b3 s1 _+ {8 e' lm_proxyans1 = (struct sock5ans1 *)buff;
memset(buff,0,600);
ClientSock.Receive(buff,600);
/ K/ Q2 Y2 P1 z* a8 O6 J6 l* fif(m_proxyans1->Ver != 5 || (m_proxyans1->Method!=0 && m_proxyans1->Method!=2))
{
  U+ q8 a! q4 ^( om_sError = _T("通过代理连接主站不成功!");
6 z" d2 }% L, P6 l  dClientSock.Close();
return FALSE;
}
3 ^. y! ]: Z) m4 F& \! E. a: ^if(m_proxyans1->Method == 2)
{
/ f+ [- }6 K% fint nUserLen = strlen(g_ProxyInfo.m_strProxyUser);
$ c0 G8 ^) l  D# O+ L) d4 R% [int nPassLen = strlen(g_ProxyInfo.m_strProxyPass);
# P: h  f, C+ H% E# r7 @struct authreq *m_authreq;
m_authreq = (struct authreq *)buff;
3 M+ o" T2 F2 N& E7 pm_authreq->Ver = 1;
- k+ A7 Y0 T7 h: L3 l! E4 O" ]. Nm_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);
struct authans *m_authans;
, r& q8 ]2 k/ I- l1 qm_authans = (struct authans *)buff;
memset(buff,0,600);
ClientSock.Receive(buff,600);
8 l1 n7 `) Y! N- I; a) f4 {8 wif(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();
return FALSE;
}
: k! l* i& ^3 S, V8 g8 w}
struct sock5req2 *m_proxyreq2;
m_proxyreq2 = (struct sock5req2 *)buff;
m_proxyreq2->Ver = 5;
m_proxyreq2->Cmd = 1;
m_proxyreq2->Rsv = 0;
m_proxyreq2->Atyp = 1;
unsigned long tmpLong = inet_addr(GetServerHostName());
unsigned short port = ntohs(GetPort());
) W# b! X- h& N4 u' hmemcpy(m_proxyreq2->other,&tmpLong,4);
memcpy(m_proxyreq2->other+4,&port,2);
ClientSock.Send(buff,sizeof(struct sock5req2)+5);
6 W, h1 v. ~3 o# S2 D# L* jstruct sock5ans2 *m_proxyans2;
3 x# t6 n2 r, Ememset(buff,0,600);
* M: M' [6 }9 e$ T: Lm_proxyans2 = (struct sock5ans2 *)buff;
ClientSock.Receive(buff,600);
if(m_proxyans2->Ver != 5 || m_proxyans2->Rep != 0)
! `5 g  a  F- l* m  g7 I{
: x, B- v6 n; f: Q0 @m_sError = _T("通过代理连接主站不成功!");
" y( S5 y6 X- J( V1 j- D6 u, J. VClientSock.Close();
return FALSE;
) X( _9 N( S7 A7 ]4 w}
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' _# k! k3 n  n8 a$ s
  n4 q' F( E( z2 I# C1 e* _//通过HTTP方式代理
if( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
: i3 @7 h: W4 M$ l7 m{
m_sError = _T("不能连接到代理服务器!");
ClientSock.Close();
- y) J9 {5 a; _2 R( Z8 y  Q; Y; h( D' rreturn FALSE;
}
char buff[600];
' @, B3 d; d& e$ Gsprintf( buff, "%s%s:%d%s","CONNECT ",GetServerHostName(),GetPort()," HTTP/1.1\r\nUser-Agent: MyApp/0.1\r\n\r\n");
& A/ b, j' W. M5 j- U  T9 i" YClientSock.Send(buff,strlen(buff)); //发送请求
memset(buff,0,600);
ClientSock.Receive(buff,600);
0 D5 A+ T' x+ R6 Qif(strstr(buff, "HTTP/1.0 200 Connection established") == NULL) //连接不成功
1 p) r8 C0 ^. D+ `: q. h{
" R1 L% i  }. z8 C7 R# qm_sError = _T("通过代理连接主站不成功!");
ClientSock.Close();
return FALSE;
8 {5 K' ~( K; o}
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。