[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
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
; ?: @' P5 B, K+ Q0 y* Pstruct sock4req1
' c, J/ ~0 V! S1 L! ~! U! n{
& {" p/ e* W; O2 S* H) _char VN;
char CD;
, [5 e+ I1 ~$ L# [8 Funsigned short Port;
unsigned long IPAddr;
  b( k' n3 V9 ^- Ichar other[1];
};
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struct sock4ans1
{
+ o" g9 {, z/ f9 [) ]char VN;
) l, F1 {6 K' uchar CD;
};
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) k2 {" n, S) z1 a" E2 `struct sock5req1
{
$ C% R! g( ~8 u: D) qchar Ver;
char nMethods;
1 E4 h" t& r* v) F* W& @char Methods[255];
};
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struct sock5ans1
{
char Ver;
char Method;
# G  I4 z( `4 a/ Y5 d: p1 _};
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struct sock5req2
1 m8 x6 V& L; ~- J! @, n. e{
char Ver;
. `$ m% F- a7 [char Cmd;
char Rsv;
* i9 |& B0 c' L; }char Atyp;
char other[1];
: @* t3 u* B7 b};
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, {6 g% O7 U3 P* r+ w" P1 @struct sock5ans2
{
char Ver;
& e! |3 u* I3 T6 W6 u0 ^char Rep;
char Rsv;
" \; `, t8 n# n# ~char Atyp;
& r: V$ v8 G) }1 }5 zchar other[1];
8 n' M4 r- j# e5 L4 r};
) ?) {/ J  k4 {wwww.chin aitpower.comJZM2iofLWRmFIxU68q4I3qxHU
struct authreq
+ F* }% J/ P2 k0 _5 H* R+ M{
char Ver;
+ N, @7 |+ U/ n: j. L; Ochar Ulen;
char Name[255];
char PLen;
char Pass[255];
};
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struct authans
{
7 p- O6 P3 V! ?! a, |$ n& Tchar Ver;
4 g4 w7 Q6 `! a) cchar Status;
};
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//通过Socks4方式代理
if( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
$ Q, F1 h. E# G3 m' R* F{
. _" h* y0 V; l& y: x+ wm_sError = _T("不能连接到代理服务器!");
ClientSock.Close();
return FALSE;
}
char buff[100];
memset(buff,0,100);
1 P* k& A3 B* ^9 L& W. Xstruct sock4req1 *m_proxyreq;
m_proxyreq = (struct sock4req1 *)buff;
m_proxyreq->VN = 4;
. V& v% ^1 H2 g+ Im_proxyreq->CD = 1;
; n3 h& `3 d4 b; m1 F+ D5 q$ K4 fm_proxyreq-&gtort = ntohs(GetPort());
9 c5 K+ O9 ~! r6 N9 J$ Mm_proxyreq->IPAddr = inet_addr(GetServerHostName());
ClientSock.Send(buff,9);
struct sock4ans1 *m_proxyans;
m_proxyans = (struct sock4ans1 *)buff;
memset(buff,0,100);
4 ~  O) y, M% w2 `) ?$ g' NClientSock.Receive(buff,100);
  r$ [& V0 j5 ~, w: R3 oif(m_proxyans->VN != 0 || m_proxyans->CD != 90)
1 V% A% P, v" X2 `( K, W4 Q9 i/ p* u{
+ @" \0 [& t2 {8 jm_sError = _T("通过代理连接主站不成功!");
ClientSock.Close();
return FALSE;
}
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//通过Socks5方式代理
if( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
{
* B$ N7 E! a' y6 `; @m_sError = _T("不能连接到代理服务器!");
4 _+ D( K" e6 K6 `ClientSock.Close();
return FALSE;
5 p4 X9 U! z# t4 B: Y}
char buff[600];
) `( q( F$ E8 s. ]0 Sstruct sock5req1 *m_proxyreq1;
m_proxyreq1 = (struct sock5req1 *)buff;
m_proxyreq1->Ver = 5;
m_proxyreq1->nMethods = 2;
. ?( f( H: G# J3 C2 H4 v# Dm_proxyreq1->Methods[0] = 0;
m_proxyreq1->Methods[1] = 2;
ClientSock.Send(buff,4);
# g7 x6 u0 Q9 W* U* tstruct sock5ans1 *m_proxyans1;
m_proxyans1 = (struct sock5ans1 *)buff;
( F# c8 G, }: L$ b* Imemset(buff,0,600);
ClientSock.Receive(buff,600);
& N6 M4 C" K3 F& f' L6 \: O1 yif(m_proxyans1->Ver != 5 || (m_proxyans1->Method!=0 && m_proxyans1->Method!=2))
{
) |/ Q- L6 l6 {& Tm_sError = _T("通过代理连接主站不成功!");
ClientSock.Close();
7 N! P" F2 y! f' _: ereturn FALSE;
  }8 J$ K+ O( k7 w4 y0 N}
if(m_proxyans1->Method == 2)
3 E- U: K7 z) |) a{
int nUserLen = strlen(g_ProxyInfo.m_strProxyUser);
1 I; W$ V7 _: E2 O3 j/ |int nPassLen = strlen(g_ProxyInfo.m_strProxyPass);
struct authreq *m_authreq;
m_authreq = (struct authreq *)buff;
# `5 R% q/ g+ m" em_authreq->Ver = 1;
7 T. F# e/ m" pm_authreq->Ulen = nUserLen;
' |) H, A2 A4 u! V8 ystrcpy(m_authreq->Name,g_ProxyInfo.m_strProxyUser);
3 H" M1 m( h9 H2 I% ^7 u) `# mm_authreq-&gtLen = nPassLen;
strcpy(m_authreq-&gtass,g_ProxyInfo.m_strProxyPass);
' @1 M5 Q! q+ N% ~ClientSock.Send(buff,513);
/ f: W: v5 G- U' n2 Ustruct authans *m_authans;
  o$ `# f% N' N7 H, t6 hm_authans = (struct authans *)buff;
memset(buff,0,600);
6 Q2 j4 d+ m4 P) m, \. H/ I' dClientSock.Receive(buff,600);
if(m_authans->Ver != 1 || m_authans->Status != 0)
5 n/ a, J& e% b4 T8 d2 D* u. m{
: o7 ?# f- k4 S/ [& U& o2 Um_sError = _T("代理服务器用户验证不成功!");
  a. t) c" |! C! ZClientSock.Close();
/ ]; b  Z$ k0 Y# p* `% kreturn FALSE;
}
}
struct sock5req2 *m_proxyreq2;
m_proxyreq2 = (struct sock5req2 *)buff;
. s- c- W/ v) {. m. F" N) Sm_proxyreq2->Ver = 5;
0 {5 C# @% S4 f% g3 qm_proxyreq2->Cmd = 1;
& x" `, R. {6 m5 _  om_proxyreq2->Rsv = 0;
) d/ H1 H. B& D# p- |m_proxyreq2->Atyp = 1;
unsigned long tmpLong = inet_addr(GetServerHostName());
! L! l& m1 M2 munsigned short port = ntohs(GetPort());
memcpy(m_proxyreq2->other,&tmpLong,4);
memcpy(m_proxyreq2->other+4,&port,2);
ClientSock.Send(buff,sizeof(struct sock5req2)+5);
! x3 A& t0 G7 Vstruct sock5ans2 *m_proxyans2;
memset(buff,0,600);
m_proxyans2 = (struct sock5ans2 *)buff;
ClientSock.Receive(buff,600);
! S$ X' j, R" o8 N" r) Vif(m_proxyans2->Ver != 5 || m_proxyans2->Rep != 0)
+ v9 V" o5 ?) ~: n{
* @7 u# E/ \& k/ _6 x# ~3 zm_sError = _T("通过代理连接主站不成功!");
ClientSock.Close();
return FALSE;
}
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0 E" S! P5 ~# \: \7 a0 T
//通过HTTP方式代理
0 p7 }2 }# A4 g  K$ m' f; f2 Qif( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
{
, E' T$ n2 |) S. O5 xm_sError = _T("不能连接到代理服务器!");
ClientSock.Close();
return FALSE;
}
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");
0 e1 J, W  U0 }) ^ClientSock.Send(buff,strlen(buff)); //发送请求
8 m. K3 D8 K  n) F7 N+ J" C, mmemset(buff,0,600);
1 X+ J. ?& g$ `/ TClientSock.Receive(buff,600);
if(strstr(buff, "HTTP/1.0 200 Connection established") == NULL) //连接不成功
. A$ q. ?% c' P' L  _1 J{
m_sError = _T("通过代理连接主站不成功!");
& H  T1 z+ _9 r" bClientSock.Close();
* i  T: ]! ~. C0 zreturn 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。