[收藏]穿透代理服务器编程

天云上人

  作者 allfresh
4 b9 Z2 h' \7 {/ x. h文章原始出处 www.allfresh.net/program/proxy.htm
+ @9 Z2 e5 x+ o4 }  rwwww.chin aitpower.comJZM2iofLWRmFIxU68q4I3qxHU
5 L' y2 V+ k. W' X0 g/ {/ q8 |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
2 P2 r8 N. V9 O8 `6 Q{
char VN;
2 ]- s7 ]3 J& x/ u5 f' b+ ?, x6 ichar CD;
unsigned short Port;
% L  i) \! r+ Aunsigned long IPAddr;
7 ?5 d, P! a( e8 u9 Ochar other[1];
1 _# w) S- A% ^- w- ]};
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struct sock4ans1
' _- P. D& C5 Q0 N, s" [{
$ F3 N( G% k! Rchar VN;
char CD;
};
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struct sock5req1
* B$ V2 f$ L2 ?! a8 {6 Q: T6 f{
char Ver;
char nMethods;
char Methods[255];
};
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$ t9 f3 N/ s7 [8 {0 Sstruct sock5ans1
{
4 p! s$ n7 Z/ L( f7 u8 tchar Ver;
char Method;
' I- L! U# g  d};
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struct sock5req2
$ y; Q6 j- E7 C2 u{
char Ver;
5 b! T0 T0 }6 ?char Cmd;
6 h: _! V) j/ V" P5 b; Qchar Rsv;
char Atyp;
$ G1 v; ^* i/ Z" l5 v3 ichar other[1];
};
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struct sock5ans2
( P$ s" J+ J" k8 U7 D{
char Ver;
char Rep;
$ x* C, E2 [1 Schar Rsv;
+ M* Q; }: B' p; ochar Atyp;
char other[1];
) k; [  H3 D+ m/ w5 X  d& e# w};
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6 m9 `0 @( T3 J  vstruct authreq
; V3 `% m5 G* V, k: O  F1 {{
; h* b$ z$ ^3 ychar Ver;
char Ulen;
- b6 g5 {7 J8 S# @  u3 m$ Mchar Name[255];
" Q3 c9 k6 I# F4 `7 T0 bchar PLen;
char Pass[255];
; Z# E* s" v  ^: |& F8 w};
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/ h  y7 t8 l4 u( hstruct authans
! v- i8 j5 b, s: h{
: w4 ?9 U' A5 W% i* ?5 b  Lchar Ver;
char Status;
};
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//通过Socks4方式代理
if( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
{
m_sError = _T("不能连接到代理服务器!");
ClientSock.Close();
0 A: k5 E6 H, ?# f/ t4 Qreturn FALSE;
}
/ P7 h- O% m& N2 x$ u2 L" n4 wchar buff[100];
memset(buff,0,100);
6 Z; }! V& _% l3 S4 O! w8 E, Hstruct sock4req1 *m_proxyreq;
m_proxyreq = (struct sock4req1 *)buff;
& _9 B, d. F; t- W9 a% B5 ~" D7 wm_proxyreq->VN = 4;
m_proxyreq->CD = 1;
m_proxyreq-&gtort = ntohs(GetPort());
m_proxyreq->IPAddr = inet_addr(GetServerHostName());
ClientSock.Send(buff,9);
3 k: Z- E) s- d3 b% N% Cstruct sock4ans1 *m_proxyans;
$ L+ u9 {/ Q' ]: km_proxyans = (struct sock4ans1 *)buff;
2 ~0 O) L( Y% dmemset(buff,0,100);
ClientSock.Receive(buff,100);
% i9 |  s3 x- b! L: X3 h! \if(m_proxyans->VN != 0 || m_proxyans->CD != 90)
{
' G/ M' H( }$ t3 J6 a; hm_sError = _T("通过代理连接主站不成功!");
ClientSock.Close();
return FALSE;
1 D! i( Y8 ?" H% R* t1 B8 ]}
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; C7 ]% p% m  J0 M
//通过Socks5方式代理
if( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
{
! H4 C( b' E+ k  p7 gm_sError = _T("不能连接到代理服务器!");
ClientSock.Close();
0 V, N9 }7 Q' w* j* I% Mreturn FALSE;
}
char buff[600];
struct sock5req1 *m_proxyreq1;
! q( a) u, p& D( D& V4 m' Sm_proxyreq1 = (struct sock5req1 *)buff;
6 n6 d: C( H6 b8 V$ L$ m0 wm_proxyreq1->Ver = 5;
m_proxyreq1->nMethods = 2;
m_proxyreq1->Methods[0] = 0;
% x. X4 y8 I+ [/ Y9 um_proxyreq1->Methods[1] = 2;
; k2 x7 V3 v' n1 P% rClientSock.Send(buff,4);
  u1 O( o2 M/ ^  D+ u7 M4 `, D$ K& estruct sock5ans1 *m_proxyans1;
m_proxyans1 = (struct sock5ans1 *)buff;
% v) O3 ~$ t6 I& \6 Mmemset(buff,0,600);
ClientSock.Receive(buff,600);
" P/ [  p  q" L, p2 J% Sif(m_proxyans1->Ver != 5 || (m_proxyans1->Method!=0 && m_proxyans1->Method!=2))
+ ?, S% @7 v, V% j! q/ G{
m_sError = _T("通过代理连接主站不成功!");
ClientSock.Close();
return FALSE;
4 P& z) A: Q/ j1 |$ D4 @+ c}
5 h% K9 e  s' [+ f& K0 U# Cif(m_proxyans1->Method == 2)
{
. N, Z) a+ S/ `6 |$ m/ u# A; }/ ^int nUserLen = strlen(g_ProxyInfo.m_strProxyUser);
int nPassLen = strlen(g_ProxyInfo.m_strProxyPass);
8 u) B$ M8 u5 D9 E" Fstruct authreq *m_authreq;
m_authreq = (struct authreq *)buff;
m_authreq->Ver = 1;
, e3 a1 A* W$ um_authreq->Ulen = nUserLen;
* @; W+ s  F- i5 C8 Fstrcpy(m_authreq->Name,g_ProxyInfo.m_strProxyUser);
m_authreq-&gtLen = nPassLen;
* ]8 Q+ A" c- D/ m7 {0 v* Y( @strcpy(m_authreq-&gtass,g_ProxyInfo.m_strProxyPass);
- ?( e5 f; y4 Z8 TClientSock.Send(buff,513);
  }! Q1 F2 y! i* p: d+ c) h  @struct authans *m_authans;
m_authans = (struct authans *)buff;
3 \9 ?8 `" q1 c! e' ]memset(buff,0,600);
/ {; F' z. M- C5 k1 ]5 r- rClientSock.Receive(buff,600);
if(m_authans->Ver != 1 || m_authans->Status != 0)
8 Z- f' k! h, r5 j. ]& t' a8 x{
m_sError = _T("代理服务器用户验证不成功!");
ClientSock.Close();
* ~: B5 U, i& Q- Y* f: @0 yreturn FALSE;
! q& a( S( r' x- q% R# U9 h}
}
struct sock5req2 *m_proxyreq2;
% Z6 B& R$ t- T+ ]0 Rm_proxyreq2 = (struct sock5req2 *)buff;
m_proxyreq2->Ver = 5;
0 B% @9 d& h; U# D/ @m_proxyreq2->Cmd = 1;
m_proxyreq2->Rsv = 0;
- m5 t0 T; i$ y) q5 j9 L( b9 Dm_proxyreq2->Atyp = 1;
unsigned long tmpLong = inet_addr(GetServerHostName());
unsigned short port = ntohs(GetPort());
memcpy(m_proxyreq2->other,&tmpLong,4);
; F) l; ]+ g, f* [" o  r5 P: Smemcpy(m_proxyreq2->other+4,&port,2);
ClientSock.Send(buff,sizeof(struct sock5req2)+5);
& j8 X7 C5 c+ _7 ^5 h$ u: ]% |* C/ istruct sock5ans2 *m_proxyans2;
memset(buff,0,600);
m_proxyans2 = (struct sock5ans2 *)buff;
ClientSock.Receive(buff,600);
/ `. H4 G/ O3 W0 E$ k( Eif(m_proxyans2->Ver != 5 || m_proxyans2->Rep != 0)
: F7 n! l1 j8 l& B{
m_sError = _T("通过代理连接主站不成功!");
, ^+ b$ j* o  DClientSock.Close();
3 v7 I" O" Z1 S* w" }return FALSE;
}
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' F* T7 x0 [! m3 F: o
//通过HTTP方式代理
if( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
7 y) g$ j* H7 Y: c. @{
m_sError = _T("不能连接到代理服务器!");
0 Y8 O+ x% c3 ^6 y: SClientSock.Close();
return FALSE;
; H5 y8 _% N" C, q& ?3 d}
0 A* `+ I$ k2 b! B1 j, fchar buff[600];
% f, L9 ]6 H2 k9 A4 Asprintf( 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);
6 S2 R/ j. j7 V4 pif(strstr(buff, "HTTP/1.0 200 Connection established") == NULL) //连接不成功
1 N( @! K% w2 X6 K9 S" U{
m_sError = _T("通过代理连接主站不成功!");
$ S$ e, ]7 c3 e+ kClientSock.Close();
5 k+ C. _2 j7 W5 {return FALSE;
+ G2 S; C7 W! w}
8 J6 R& l2 S) B$ U% _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。