[收藏]穿透代理服务器编程

天云上人

  作者 allfresh
7 s" G, G% ^/ n# g' v. @! r文章原始出处 www.allfresh.net/program/proxy.htm
, n- H1 `0 X" C- W" G+ }wwww.chin aitpower.comJZM2iofLWRmFIxU68q4I3qxHU
正文
4 W. Y; `( D, a* M# K7 E; K! S6 ?& O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
{
char VN;
char CD;
unsigned short Port;
9 {; G# F0 t" G. f% \( H4 Lunsigned long IPAddr;
char other[1];
( v1 x- `" ~& x- `$ ^: J};
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struct sock4ans1
{
; P7 ?! A0 g9 d7 L+ x( echar VN;
6 k/ ^. b2 T1 Nchar CD;
) o6 A6 R+ b# K2 V3 k) J};
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struct sock5req1
) O0 M* J$ }3 `: {5 d) ?% `6 |( L{
char Ver;
  h9 V7 Y! e7 U* p8 v+ k; {char nMethods;
. Q! C$ h7 H/ J2 ~char Methods[255];
. `) g7 }# L! u  w* X};
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struct sock5ans1
$ K1 ^! d- s9 Z- m" D' |' o9 W3 ^{
char Ver;
/ i9 Z$ l& k' h) Cchar Method;
3 W  v0 m( M1 P7 ^};
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- r# A9 X, v. Z; [: }struct sock5req2
9 _) g! k5 z! O) S# f4 d9 G{
char Ver;
char Cmd;
( `1 |4 s  Y4 Dchar Rsv;
char Atyp;
char other[1];
};
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struct sock5ans2
{
$ ?9 M3 S* _, {. e; g0 Ichar Ver;
; d9 o# p1 O9 V4 Q/ |# }char Rep;
/ K0 @2 D; }$ @char Rsv;
: }7 N1 J' b7 x( rchar Atyp;
( J1 Q6 q7 H& H8 b: E8 Tchar other[1];
2 s7 h: W& D9 x5 c& R  Q};
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struct authreq
' V/ @* U" k0 A5 G/ s" W$ g. t{
char Ver;
char Ulen;
char Name[255];
5 o9 X: j% G! n4 J+ r6 [: dchar PLen;
( M4 z0 Y8 x6 E3 ]7 Wchar Pass[255];
};
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% G, V( v' i5 _+ sstruct authans
{
& K' u, e+ K; O  a. F- F, zchar Ver;
char Status;
; C/ W8 h5 i+ z( Z};
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; E/ A& V' U  B3 J1 e3 R//通过Socks4方式代理
if( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
5 d8 ]/ ?1 o* d" ^8 y! m{
m_sError = _T("不能连接到代理服务器!");
ClientSock.Close();
4 f9 N& L" q5 F' V3 j# @' lreturn FALSE;
}
: {9 E3 j7 c, wchar buff[100];
memset(buff,0,100);
struct sock4req1 *m_proxyreq;
* F1 X# }$ x* r( b7 u1 H1 B5 am_proxyreq = (struct sock4req1 *)buff;
m_proxyreq->VN = 4;
m_proxyreq->CD = 1;
m_proxyreq-&gtort = ntohs(GetPort());
& D  y' Z: d# m( n. ^: Km_proxyreq->IPAddr = inet_addr(GetServerHostName());
' ~( n( E  u* G/ ~) cClientSock.Send(buff,9);
: K3 U- U2 G' B; Bstruct sock4ans1 *m_proxyans;
m_proxyans = (struct sock4ans1 *)buff;
memset(buff,0,100);
ClientSock.Receive(buff,100);
5 n* N: v8 @" E9 G# W* n: b8 ~if(m_proxyans->VN != 0 || m_proxyans->CD != 90)
{
# G$ c: ^- J% Vm_sError = _T("通过代理连接主站不成功!");
ClientSock.Close();
8 s- c) ~1 U$ _return FALSE;
' T* {( e% x5 X# L5 H+ m/ z- a' K}
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" f3 @$ }& P* t& L( a1 U
//通过Socks5方式代理
, y' c7 Q0 }  k- E  v" Zif( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
) j+ V7 A) F- L0 S{
2 U# N( b) u3 W& b6 e" k" Q' Vm_sError = _T("不能连接到代理服务器!");
+ W$ J! N. @! ~) G! k9 E/ IClientSock.Close();
/ ~. ?* w* X4 Y, e# R% c" Creturn FALSE;
# I2 C* v( T5 L) L4 [9 e, S% S; H+ b}
char buff[600];
struct sock5req1 *m_proxyreq1;
m_proxyreq1 = (struct sock5req1 *)buff;
. U- l  |0 w' O2 \0 M6 o& om_proxyreq1->Ver = 5;
% C0 Z1 ~& P, {8 C- l! o) x. M" ?m_proxyreq1->nMethods = 2;
) p& ~# x- ^$ F7 Sm_proxyreq1->Methods[0] = 0;
m_proxyreq1->Methods[1] = 2;
' b. a9 V4 N6 f- vClientSock.Send(buff,4);
struct sock5ans1 *m_proxyans1;
m_proxyans1 = (struct sock5ans1 *)buff;
. l! ~. q5 ]% `  @memset(buff,0,600);
: ^4 N% q$ D/ a6 S& e: TClientSock.Receive(buff,600);
if(m_proxyans1->Ver != 5 || (m_proxyans1->Method!=0 && m_proxyans1->Method!=2))
{
* S$ i. @/ F. [4 Q) X- q' gm_sError = _T("通过代理连接主站不成功!");
ClientSock.Close();
4 B8 z1 t* w0 D4 `return FALSE;
, T9 n0 T0 {3 z0 M}
if(m_proxyans1->Method == 2)
) b# X5 ^' V- ?{
3 e3 t* s1 G3 D* n% c/ b7 t6 V. D1 ?int nUserLen = strlen(g_ProxyInfo.m_strProxyUser);
, \% N8 p/ x& Iint nPassLen = strlen(g_ProxyInfo.m_strProxyPass);
struct authreq *m_authreq;
m_authreq = (struct authreq *)buff;
4 `0 f& l& c% Q. b+ p" a" tm_authreq->Ver = 1;
5 V' J) X0 I- ~, \+ f1 ?m_authreq->Ulen = nUserLen;
strcpy(m_authreq->Name,g_ProxyInfo.m_strProxyUser);
m_authreq-&gtLen = nPassLen;
- M) G0 ?0 P1 P4 c% T+ sstrcpy(m_authreq-&gtass,g_ProxyInfo.m_strProxyPass);
1 Q) {& h( t$ ?/ R0 p, MClientSock.Send(buff,513);
/ ?0 U, v- F" I! l/ M1 H# s5 D* @$ Jstruct authans *m_authans;
m_authans = (struct authans *)buff;
" ?3 z2 C6 X  d/ Mmemset(buff,0,600);
ClientSock.Receive(buff,600);
' d2 C$ ?1 F4 V7 H, Lif(m_authans->Ver != 1 || m_authans->Status != 0)
{
8 Y( C! j# B+ [& l( U6 hm_sError = _T("代理服务器用户验证不成功!");
ClientSock.Close();
return FALSE;
}
}
struct sock5req2 *m_proxyreq2;
m_proxyreq2 = (struct sock5req2 *)buff;
' V0 `4 T9 Q! |) Z* a9 Q+ N# dm_proxyreq2->Ver = 5;
m_proxyreq2->Cmd = 1;
m_proxyreq2->Rsv = 0;
; W2 A  X$ J& O4 _% nm_proxyreq2->Atyp = 1;
unsigned long tmpLong = inet_addr(GetServerHostName());
unsigned short port = ntohs(GetPort());
- p5 G3 [* }7 Vmemcpy(m_proxyreq2->other,&tmpLong,4);
memcpy(m_proxyreq2->other+4,&port,2);
ClientSock.Send(buff,sizeof(struct sock5req2)+5);
struct sock5ans2 *m_proxyans2;
6 ?! P  K6 X# f5 l4 R. `memset(buff,0,600);
9 w! A! }- W7 Q# y1 Ym_proxyans2 = (struct sock5ans2 *)buff;
* [: N- k& ]0 j8 O% O3 wClientSock.Receive(buff,600);
if(m_proxyans2->Ver != 5 || m_proxyans2->Rep != 0)
{
) b2 {2 L8 h% ~0 o2 N3 m; T6 i( ^, A/ Cm_sError = _T("通过代理连接主站不成功!");
5 F' L2 P% Q, j% ~* `ClientSock.Close();
2 ^( W7 v* i% @: ^1 S3 @) hreturn FALSE;
/ ~+ a% S, A# [8 \3 e% A- {+ W}
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8 ]; C( G* c; ~0 F( O$ {
. J5 m" _. X; @5 X3 `7 Z& z* s/ P! J//通过HTTP方式代理
% {# L$ H0 C( m+ s+ q; mif( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
9 N2 b  R9 @% q6 X3 g; `: b% m{
' D) t/ }! r3 L, ?: g* fm_sError = _T("不能连接到代理服务器!");
$ c& @' T1 r9 C* D. WClientSock.Close();
return FALSE;
}
3 Q/ u' v1 F& C% @; echar buff[600];
6 K, I2 n. T3 Bsprintf( buff, "%s%s:%d%s","CONNECT ",GetServerHostName(),GetPort()," HTTP/1.1\r\nUser-Agent: MyApp/0.1\r\n\r\n");
5 `% B6 f& A1 ?- X' B" aClientSock.Send(buff,strlen(buff)); //发送请求
memset(buff,0,600);
% Q" y* t. w. f" g1 S" KClientSock.Receive(buff,600);
if(strstr(buff, "HTTP/1.0 200 Connection established") == NULL) //连接不成功
- j5 H6 d0 r* R' i- P8 S( v) @{
5 y4 z- g( S: q% Im_sError = _T("通过代理连接主站不成功!");
ClientSock.Close();
7 `# P( W: t9 M1 Greturn FALSE;
}
9 k& O/ `8 L% |0 O5 t2 T. o8 N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。