[收藏]穿透代理服务器编程

天云上人

  作者 allfresh
$ K* g  }1 w, K' K+ e9 c文章原始出处 www.allfresh.net/program/proxy.htm
$ Z3 F& |3 F# e( K$ `  {wwww.chin aitpower.comJZM2iofLWRmFIxU68q4I3qxHU
" H2 b# o7 L$ t* J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。
4 S+ z7 [, g0 h( z6 V# E5 f. `wwww.chin aitpower.comJZM2iofLWRmFIxU68q4I3qxHU
9 I0 Y$ V: d. y% d+ A//使用到的结构
, n8 k6 `+ ~% m& N6 c8 L) Gstruct sock4req1
{
char VN;
char CD;
$ V9 Y8 B4 \' @4 o$ \2 e" V' G7 C& Uunsigned short Port;
unsigned long IPAddr;
2 O. D$ H% ]) N# Ychar other[1];
};
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, [) m( y7 z8 D$ \2 Vstruct sock4ans1
{
char VN;
9 K; _+ G" I! B3 Nchar CD;
};
6 G: U5 V5 V# G! q  \+ owwww.chin aitpower.comJZM2iofLWRmFIxU68q4I3qxHU
struct sock5req1
: M; }% H8 j$ J5 G+ L3 v3 ~/ Z{
char Ver;
0 P+ p+ E, F; f8 ^) _  jchar nMethods;
char Methods[255];
};
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1 Q  {4 R: C  {: cstruct sock5ans1
{
char Ver;
char Method;
};
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struct sock5req2
{
, I% j% Q$ o$ I8 Kchar Ver;
4 ?5 E9 C- A( O7 h4 d% vchar Cmd;
5 @8 h2 _0 w1 `1 ]9 _: I! Ochar Rsv;
char Atyp;
char other[1];
% o9 ~/ e* b5 ?. [" s};
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% R$ a6 R; J  K8 h- Fstruct sock5ans2
4 M( ^" r/ S  J5 `1 D$ x{
char Ver;
6 ]$ l3 g& z+ N9 @# pchar Rep;
3 `! D! m0 j. _/ Z( l1 hchar Rsv;
, E7 S" B. k- h9 J8 N7 Xchar Atyp;
char other[1];
& ?: e5 D- X/ g- e& W};
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struct authreq
{
7 w/ w1 L+ `8 Ychar Ver;
char Ulen;
: L1 e3 A: h8 h; v4 Q  y5 z3 achar Name[255];
char PLen;
char Pass[255];
};
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struct authans
2 l' H% Q& L) G, }{
char Ver;
char Status;
) g" h  g8 A. L" |6 B5 j$ v$ c) }};
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/ y6 s8 R: B+ n! ~& P//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();
9 y9 ^% U; h# Creturn FALSE;
" W6 M0 \5 d1 j  |, c- q% M) `" j}
$ Y# S, L$ @, @2 c. b2 x& S4 n' pchar buff[100];
# T/ V3 z) T" c5 \; Amemset(buff,0,100);
/ H5 w) A. m" r9 n0 P; d( [struct sock4req1 *m_proxyreq;
$ ]7 D! U- X) y0 d  Xm_proxyreq = (struct sock4req1 *)buff;
: Y+ c  c" J" R# S8 lm_proxyreq->VN = 4;
% X; p( J; e5 l. l5 ~- nm_proxyreq->CD = 1;
m_proxyreq-&gtort = ntohs(GetPort());
, b1 z+ p% d! C, R: ym_proxyreq->IPAddr = inet_addr(GetServerHostName());
! [9 I; h  W0 U; T; Z3 ~+ \ClientSock.Send(buff,9);
# n6 X. M6 f" ]6 ?struct sock4ans1 *m_proxyans;
" Y& f4 n( U$ V4 S7 ~m_proxyans = (struct sock4ans1 *)buff;
7 e: x" f7 d& y. q& g- Jmemset(buff,0,100);
ClientSock.Receive(buff,100);
if(m_proxyans->VN != 0 || m_proxyans->CD != 90)
9 V: i& I/ W/ f{
m_sError = _T("通过代理连接主站不成功!");
+ Q' w) g3 ~1 J" AClientSock.Close();
& K) R4 e( _* ^; e' X* E% G8 zreturn FALSE;
}
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2 W9 c7 \6 l: ^9 _  W( X//通过Socks5方式代理
if( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
{
% C6 i+ b( p$ P! T1 D; D' [7 Pm_sError = _T("不能连接到代理服务器!");
. m" u& _# f; s4 z& v; x5 ?0 y4 WClientSock.Close();
return FALSE;
  E5 @$ z# Q3 v# M}
char buff[600];
struct sock5req1 *m_proxyreq1;
  a6 G8 t! d# w1 i, T) g3 {# [- ~m_proxyreq1 = (struct sock5req1 *)buff;
# ^+ T, f8 v" Hm_proxyreq1->Ver = 5;
m_proxyreq1->nMethods = 2;
, A( P: n* X% j; lm_proxyreq1->Methods[0] = 0;
m_proxyreq1->Methods[1] = 2;
) l& e! Y" G  B6 d/ t- kClientSock.Send(buff,4);
struct sock5ans1 *m_proxyans1;
2 M+ X4 ~0 n3 rm_proxyans1 = (struct sock5ans1 *)buff;
  A$ Q+ _5 M) D8 O* }memset(buff,0,600);
ClientSock.Receive(buff,600);
* X5 |9 i2 x3 Dif(m_proxyans1->Ver != 5 || (m_proxyans1->Method!=0 && m_proxyans1->Method!=2))
- Z! V2 X* @9 |  ?+ L& u{
6 ]  T" t/ x; m8 U8 zm_sError = _T("通过代理连接主站不成功!");
ClientSock.Close();
return FALSE;
/ U% \$ ?' L  }! T1 ^}
* m1 I, h$ t2 h/ C0 K5 c" rif(m_proxyans1->Method == 2)
" ?& O9 o- Z8 y{
: ?0 ?* r( X% c# R; sint nUserLen = strlen(g_ProxyInfo.m_strProxyUser);
4 O# r% M% Q/ H% s! V/ N  Y4 ~int nPassLen = strlen(g_ProxyInfo.m_strProxyPass);
+ S& D7 g% b1 H" I1 Y) Nstruct authreq *m_authreq;
m_authreq = (struct authreq *)buff;
2 _% _' n  p' um_authreq->Ver = 1;
- w1 s" S& _# d- ?" _m_authreq->Ulen = nUserLen;
strcpy(m_authreq->Name,g_ProxyInfo.m_strProxyUser);
m_authreq-&gtLen = nPassLen;
strcpy(m_authreq-&gtass,g_ProxyInfo.m_strProxyPass);
- d( }+ i1 ]! y# b: {% _0 VClientSock.Send(buff,513);
2 o( w+ [4 r0 j2 Z' Q1 M6 fstruct authans *m_authans;
m_authans = (struct authans *)buff;
" {+ ~$ S+ j" ?! b" A6 Z' }# S9 u3 Umemset(buff,0,600);
2 J9 A$ [. |5 t! M4 b+ b- C# tClientSock.Receive(buff,600);
2 z( ~4 N+ x' ?" R4 l2 o, d0 nif(m_authans->Ver != 1 || m_authans->Status != 0)
{
% _# X( G; j5 c2 n) Em_sError = _T("代理服务器用户验证不成功!");
1 J) Q' w0 V- {0 U# C, v7 `ClientSock.Close();
return FALSE;
}
}
struct sock5req2 *m_proxyreq2;
m_proxyreq2 = (struct sock5req2 *)buff;
! J" g. V! {5 B, H' Jm_proxyreq2->Ver = 5;
m_proxyreq2->Cmd = 1;
m_proxyreq2->Rsv = 0;
- U! H) _7 C, sm_proxyreq2->Atyp = 1;
unsigned long tmpLong = inet_addr(GetServerHostName());
2 U9 j2 j1 n. i' i7 h# R/ u1 Dunsigned short port = ntohs(GetPort());
( J5 G. a+ B; z5 p  |( J# H3 e. i: Hmemcpy(m_proxyreq2->other,&tmpLong,4);
memcpy(m_proxyreq2->other+4,&port,2);
* g* }, t) B' n6 B0 WClientSock.Send(buff,sizeof(struct sock5req2)+5);
, }& C+ A+ R6 P9 s; Zstruct sock5ans2 *m_proxyans2;
' b  B5 ^, ?; U& n* Mmemset(buff,0,600);
m_proxyans2 = (struct sock5ans2 *)buff;
' ]; g( u# }! z/ ?+ Q/ r5 s8 ^ClientSock.Receive(buff,600);
6 F0 {% Q. l" h1 j8 lif(m_proxyans2->Ver != 5 || m_proxyans2->Rep != 0)
. s6 j( y9 _+ `{
m_sError = _T("通过代理连接主站不成功!");
8 L; b' m. }2 J# `- }4 |: WClientSock.Close();
return FALSE;
8 k1 `, D) B5 \* t, ]}
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//通过HTTP方式代理
if( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
{
" o4 H$ U) o2 H# n! e& ^, ~# km_sError = _T("不能连接到代理服务器!");
9 J& C# Y! p3 UClientSock.Close();
return FALSE;
}
char buff[600];
; L' |8 \  m$ ]0 B* r4 m. R! Dsprintf( buff, "%s%s:%d%s","CONNECT ",GetServerHostName(),GetPort()," HTTP/1.1\r\nUser-Agent: MyApp/0.1\r\n\r\n");
3 w  V- J1 W  ]  i3 pClientSock.Send(buff,strlen(buff)); //发送请求
3 ?! r% n& n4 Zmemset(buff,0,600);
ClientSock.Receive(buff,600);
* }5 v( ~# Z% \! H' iif(strstr(buff, "HTTP/1.0 200 Connection established") == NULL) //连接不成功
1 q0 Q$ k8 G7 [. `+ L{
m_sError = _T("通过代理连接主站不成功!");
ClientSock.Close();
8 s/ s% l- s0 w: jreturn FALSE;
}
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。