[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
/ `0 o  ?# z8 T9 W$ z' j% {wwww.chin aitpower.comJZM2iofLWRmFIxU68q4I3qxHU
正文
2 l5 p7 n) x7 Q2 n, U' [- K! B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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! J; r+ M4 w0 S6 ?( d* c//使用到的结构
5 m( X, o/ r  A! Dstruct sock4req1
{
7 T- u  f! a) \# ^  _char VN;
char CD;
unsigned short Port;
* H1 ?, z  g& e9 Lunsigned long IPAddr;
$ ?" p+ V) m+ [( e6 Z" O* Wchar other[1];
9 C: R: t. T, _" f5 }8 q};
8 p* l; a7 ~$ U0 c5 cwwww.chin aitpower.comJZM2iofLWRmFIxU68q4I3qxHU
/ S/ v/ J- E1 M& O( |5 N1 l0 W  m# o7 fstruct sock4ans1
+ a- p2 T1 @( |* q) F2 X( w7 h{
. T. y- W+ _: y& ochar VN;
) v# b9 `4 [! u$ @9 T- W  Kchar CD;
" X$ S. A8 Q5 F1 M7 q% E; k* t4 y1 ]};
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, W+ T" s5 H+ J) Pstruct sock5req1
{
! q' T4 }" t, A$ B- Nchar Ver;
char nMethods;
% F: W* G9 I4 j* Z4 f( S. fchar Methods[255];
};
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: n) X! s3 X, sstruct sock5ans1
{
char Ver;
4 b$ R$ L4 w. r& \5 r6 P$ P5 \char Method;
};
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struct sock5req2
{
char Ver;
1 X& V: [- Z) S/ F3 Cchar Cmd;
char Rsv;
  G! j' {' l) Gchar Atyp;
% H2 Z5 y; y& Gchar other[1];
};
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, @/ v* v* a! g8 t; j/ A7 E9 Zstruct sock5ans2
{
& H, z0 Z( S" X1 A" qchar Ver;
4 N& |. h* L4 l* o3 H5 kchar Rep;
char Rsv;
char Atyp;
char other[1];
$ N; g% X, T, w- y) I};
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5 e2 N  |  J& j$ rstruct authreq
{
char Ver;
char Ulen;
8 F! `$ h5 s; f( D* uchar Name[255];
char PLen;
/ C7 L& L* u9 f0 l' Zchar Pass[255];
! s! C9 W/ M$ W7 J2 z/ D) |- e};
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1 R& d! l4 U4 o+ Wstruct authans
6 G6 ]. T3 p! P' L; K{
char 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) )
{
: E2 B# j* Y' ?9 |# lm_sError = _T("不能连接到代理服务器!");
0 [. t9 G4 S( m2 MClientSock.Close();
. t1 S( z! T) K) p" y' n  g' t; ]return FALSE;
% }5 X& \+ f9 H# b0 I}
- Q$ a5 u, @# X% ]- ?+ Jchar buff[100];
memset(buff,0,100);
struct sock4req1 *m_proxyreq;
m_proxyreq = (struct sock4req1 *)buff;
m_proxyreq->VN = 4;
2 j0 K+ w& [% l& ~$ D& rm_proxyreq->CD = 1;
m_proxyreq-&gtort = ntohs(GetPort());
( [8 X1 ]6 y3 Z. E/ S  ~m_proxyreq->IPAddr = inet_addr(GetServerHostName());
4 k. d  v: ^: F$ e5 F) i1 X' GClientSock.Send(buff,9);
7 b2 T( N& o5 w" z( q  d( h$ x  _, Y# X/ u6 Gstruct sock4ans1 *m_proxyans;
* p4 D' Z0 b2 am_proxyans = (struct sock4ans1 *)buff;
memset(buff,0,100);
* w7 x& m2 W- L1 C$ mClientSock.Receive(buff,100);
3 @  X6 l/ y0 f1 O* M0 oif(m_proxyans->VN != 0 || m_proxyans->CD != 90)
  Z. d* O9 U- s4 V* e3 _{
, d9 Q2 I0 w  q( Z# s$ T* y+ Um_sError = _T("通过代理连接主站不成功!");
ClientSock.Close();
return FALSE;
1 C+ C- v9 c0 z5 W& v! I! V}
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//通过Socks5方式代理
. [1 F  ]" [  O; sif( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
{
8 L- c* T5 ?2 t( S, \( z0 m1 U2 {+ Bm_sError = _T("不能连接到代理服务器!");
ClientSock.Close();
* ?: {5 X- h, ]% i. I7 {% zreturn FALSE;
}
& A8 ?5 S& o8 N/ ?3 r6 Rchar buff[600];
- B. ?* J; x* n: G  x* i7 Qstruct sock5req1 *m_proxyreq1;
& N1 L8 f3 }* Km_proxyreq1 = (struct sock5req1 *)buff;
. v/ w& y: m  B1 Zm_proxyreq1->Ver = 5;
5 s2 {, o+ O$ N& ?$ M4 |m_proxyreq1->nMethods = 2;
+ r" V% F$ K4 R1 C; |- e; x+ k' `( tm_proxyreq1->Methods[0] = 0;
- n; L+ y) W; T" dm_proxyreq1->Methods[1] = 2;
ClientSock.Send(buff,4);
0 y2 Z6 J( W% k/ h9 n0 sstruct sock5ans1 *m_proxyans1;
m_proxyans1 = (struct sock5ans1 *)buff;
memset(buff,0,600);
ClientSock.Receive(buff,600);
if(m_proxyans1->Ver != 5 || (m_proxyans1->Method!=0 && m_proxyans1->Method!=2))
{
! y: z0 t6 ]8 P) L* ym_sError = _T("通过代理连接主站不成功!");
  y* D% z+ [& V- mClientSock.Close();
return FALSE;
- c8 A2 a3 W2 U& x. W" q% L6 S}
% W; `1 s4 T" Z: Q0 i0 i; l8 _6 tif(m_proxyans1->Method == 2)
{
int nUserLen = strlen(g_ProxyInfo.m_strProxyUser);
int nPassLen = strlen(g_ProxyInfo.m_strProxyPass);
struct authreq *m_authreq;
m_authreq = (struct authreq *)buff;
m_authreq->Ver = 1;
m_authreq->Ulen = nUserLen;
strcpy(m_authreq->Name,g_ProxyInfo.m_strProxyUser);
- ?5 Z4 h+ A- p5 sm_authreq-&gtLen = nPassLen;
7 U3 G+ V* |" Y* u% Hstrcpy(m_authreq-&gtass,g_ProxyInfo.m_strProxyPass);
8 C3 G, m' v# l8 Q6 TClientSock.Send(buff,513);
struct authans *m_authans;
m_authans = (struct authans *)buff;
memset(buff,0,600);
' E7 ?/ {6 v. g  G9 Q6 D$ h) A/ xClientSock.Receive(buff,600);
if(m_authans->Ver != 1 || m_authans->Status != 0)
' }: C& F7 D) d{
m_sError = _T("代理服务器用户验证不成功!");
2 |+ u, M, g" K; z5 O8 aClientSock.Close();
% E/ [- D- Y2 ~, I1 ]return FALSE;
}
4 L4 o6 s4 s! U" b+ J# Q( n}
struct sock5req2 *m_proxyreq2;
m_proxyreq2 = (struct sock5req2 *)buff;
m_proxyreq2->Ver = 5;
m_proxyreq2->Cmd = 1;
1 k. [: l3 Q2 x; n2 @m_proxyreq2->Rsv = 0;
, y% L* R, X" Nm_proxyreq2->Atyp = 1;
unsigned long tmpLong = inet_addr(GetServerHostName());
' [, k) t% w) @" j. zunsigned short port = ntohs(GetPort());
memcpy(m_proxyreq2->other,&tmpLong,4);
; O- @2 P; ~! P6 f- V- g. {. P% mmemcpy(m_proxyreq2->other+4,&port,2);
ClientSock.Send(buff,sizeof(struct sock5req2)+5);
struct sock5ans2 *m_proxyans2;
memset(buff,0,600);
m_proxyans2 = (struct sock5ans2 *)buff;
ClientSock.Receive(buff,600);
if(m_proxyans2->Ver != 5 || m_proxyans2->Rep != 0)
{
m_sError = _T("通过代理连接主站不成功!");
- E: F1 J* x& G4 D5 e/ u1 f  L, gClientSock.Close();
. L2 f, Z3 a8 k7 Y7 Areturn FALSE;
}
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8 s- E! C8 b+ C1 K
//通过HTTP方式代理
if( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
{
3 ?& X- j2 S) _7 l  T' s! Lm_sError = _T("不能连接到代理服务器!");
% W; u$ Z/ O& N4 ], ~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");
ClientSock.Send(buff,strlen(buff)); //发送请求
' _0 L# P) T$ d3 m2 w9 Gmemset(buff,0,600);
ClientSock.Receive(buff,600);
% O% I- J8 w" a6 u2 wif(strstr(buff, "HTTP/1.0 200 Connection established") == NULL) //连接不成功
' z, O  \! ?3 S! D{
m_sError = _T("通过代理连接主站不成功!");
% p5 K: s% b# I- t( p7 U. XClientSock.Close();
* b' `5 j+ `1 d9 a- 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。