[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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& h" b' ^, o/ ?2 ~8 r8 e' q正文
/ L3 H' {7 w: B* Z( Z2 ^# C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;
4 n& t$ X8 E; r; xunsigned long IPAddr;
char other[1];
$ A1 w; \. `9 Z  y+ L- l};
$ Y1 _6 U* h  f; u3 Kwwww.chin aitpower.comJZM2iofLWRmFIxU68q4I3qxHU
struct sock4ans1
  D# o1 F# w: g1 r{
char VN;
char CD;
! Y- B  `+ y' w- i! K* D};
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5 n4 I6 S# v5 `( Dstruct sock5req1
{
char Ver;
3 }* q% B. U0 }# vchar nMethods;
) V1 A' V1 Y/ [  F3 Pchar Methods[255];
};
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+ V  u; ^0 x7 B* X0 b( Vstruct sock5ans1
0 Q* ~' r+ N- E  f3 J$ i5 E8 b{
" t  O% x: p, L; ?/ k0 E1 d: W: D7 ochar Ver;
char Method;
};
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, z- q& ]9 Z7 J  k% c+ v7 D$ ~$ h& mstruct sock5req2
: R8 D. ]+ t& X% I{
  Y' f9 B- I2 [2 N# K" K% h; |' fchar Ver;
char Cmd;
char Rsv;
char Atyp;
char other[1];
};
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" y* q) w! f/ i# l3 R. w/ astruct sock5ans2
* J8 `8 k+ P4 U0 k: h{
char Ver;
% g, K) F1 W& ]3 {char Rep;
char Rsv;
char Atyp;
char other[1];
};
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+ Q; q% y9 @- ^3 e# mstruct authreq
5 i4 R% L1 `( `0 U{
char Ver;
char Ulen;
char Name[255];
char PLen;
char Pass[255];
2 |# k# O3 A! G; c};
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struct authans
, i% z3 u: W, c- w& h% O, x{
char Ver;
0 q, s2 @& g; l, X$ Ychar Status;
. @! |. O- N4 l( v};
1 {5 N% j0 J1 b+ G/ lwwww.chin aitpower.comJZM2iofLWRmFIxU68q4I3qxHU
//通过Socks4方式代理
if( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
4 I8 [  D2 J) d* d  D& R, [9 f{
: ^$ a" e9 r& Q+ F* p, R/ Vm_sError = _T("不能连接到代理服务器!");
ClientSock.Close();
% F# B: r) {$ b! h1 d/ `return FALSE;
}
$ Z8 z% U" }: p6 u7 J8 i% U7 }char buff[100];
7 j3 |; {( b4 `2 W) R' ^5 k$ Y& ~& P5 omemset(buff,0,100);
struct sock4req1 *m_proxyreq;
* Z8 u( u& `0 a  q0 f; \m_proxyreq = (struct sock4req1 *)buff;
. Z& d4 d+ R0 r7 q" x5 Q/ Bm_proxyreq->VN = 4;
m_proxyreq->CD = 1;
m_proxyreq-&gtort = ntohs(GetPort());
m_proxyreq->IPAddr = inet_addr(GetServerHostName());
- m1 u5 I! S5 E  O# [ClientSock.Send(buff,9);
! q/ E; I& Y: V! l7 S* }/ Pstruct sock4ans1 *m_proxyans;
m_proxyans = (struct sock4ans1 *)buff;
memset(buff,0,100);
2 a( e9 }3 ?, t. h3 G& J8 dClientSock.Receive(buff,100);
; |" [' V# k4 L* p- A! L* X9 ?% }if(m_proxyans->VN != 0 || m_proxyans->CD != 90)
( Z5 z, i) C. E  l{
& \1 [! z6 }1 q+ E+ Km_sError = _T("通过代理连接主站不成功!");
% a, L% z/ I4 r% ~* {ClientSock.Close();
0 r& _% ?- w& Mreturn FALSE;
}
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: j; m0 t+ }. F/ \, k//通过Socks5方式代理
if( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
1 P  ^6 O' B5 `9 Z' t# A5 H{
m_sError = _T("不能连接到代理服务器!");
ClientSock.Close();
return FALSE;
+ O: H5 v& \( ~2 _3 @8 L}
" c" n3 M- X1 Echar buff[600];
3 R; ]. b- k+ kstruct sock5req1 *m_proxyreq1;
m_proxyreq1 = (struct sock5req1 *)buff;
4 `+ }% _8 Z, }$ G8 km_proxyreq1->Ver = 5;
4 R& `0 {3 I5 {& ]m_proxyreq1->nMethods = 2;
m_proxyreq1->Methods[0] = 0;
& W; J* L- e7 sm_proxyreq1->Methods[1] = 2;
  u' g& O* J4 h: x( @% l8 jClientSock.Send(buff,4);
! l+ G2 @1 a9 [- H6 Hstruct sock5ans1 *m_proxyans1;
m_proxyans1 = (struct sock5ans1 *)buff;
9 G8 \6 o4 [# Z- Umemset(buff,0,600);
0 G; _+ f+ G+ W* nClientSock.Receive(buff,600);
) O. X" x7 b( C6 v1 rif(m_proxyans1->Ver != 5 || (m_proxyans1->Method!=0 && m_proxyans1->Method!=2))
{
6 @4 `# u* n* y4 X9 e2 t# im_sError = _T("通过代理连接主站不成功!");
ClientSock.Close();
0 }& X+ J# Q' ^* nreturn FALSE;
( l3 R/ j; b/ m9 ]: G* @" ?}
9 G- h$ Y2 T1 P* W) ~if(m_proxyans1->Method == 2)
5 q2 t0 H$ z8 k: K{
int nUserLen = strlen(g_ProxyInfo.m_strProxyUser);
int nPassLen = strlen(g_ProxyInfo.m_strProxyPass);
9 [/ H" j, j1 }, M$ j8 hstruct authreq *m_authreq;
m_authreq = (struct authreq *)buff;
+ J( X9 }$ i+ C0 Nm_authreq->Ver = 1;
+ H1 h# {) s/ t( H- d  Z5 ~, `, F/ o& H; tm_authreq->Ulen = nUserLen;
) O" F. `7 _8 _* Y2 [strcpy(m_authreq->Name,g_ProxyInfo.m_strProxyUser);
m_authreq-&gtLen = nPassLen;
$ d: k, ]# I4 [7 n: ?  X" f4 sstrcpy(m_authreq-&gtass,g_ProxyInfo.m_strProxyPass);
ClientSock.Send(buff,513);
$ R4 E* C4 h2 Q: V; U# k- wstruct authans *m_authans;
m_authans = (struct authans *)buff;
7 }, L% z% M7 J7 C$ k. `! {memset(buff,0,600);
& S/ l6 M% e4 o/ E& g. ?- nClientSock.Receive(buff,600);
if(m_authans->Ver != 1 || m_authans->Status != 0)
( L5 }  p- D9 i! ]{
$ l! r) X# S" T3 ^3 tm_sError = _T("代理服务器用户验证不成功!");
ClientSock.Close();
return FALSE;
}
}
* O! X  ]; l$ I' I- istruct sock5req2 *m_proxyreq2;
; A, O; i' j# ?/ xm_proxyreq2 = (struct sock5req2 *)buff;
, X9 A( s: u$ U4 W  V5 ^" _* ]0 om_proxyreq2->Ver = 5;
m_proxyreq2->Cmd = 1;
8 ?6 ]( V' d) `0 w4 zm_proxyreq2->Rsv = 0;
m_proxyreq2->Atyp = 1;
* W$ |3 |1 X3 q( H" x5 o# xunsigned long tmpLong = inet_addr(GetServerHostName());
$ Y+ |- m/ ~/ k, F/ {9 T0 vunsigned short port = ntohs(GetPort());
, R1 A. i- s$ s* j' C* V7 b% @& {# Imemcpy(m_proxyreq2->other,&tmpLong,4);
memcpy(m_proxyreq2->other+4,&port,2);
( q/ @+ C% M( v6 _- n% OClientSock.Send(buff,sizeof(struct sock5req2)+5);
2 i7 ?/ i, b2 vstruct sock5ans2 *m_proxyans2;
1 n. t, A$ L2 I# F3 A! xmemset(buff,0,600);
m_proxyans2 = (struct sock5ans2 *)buff;
ClientSock.Receive(buff,600);
% O, Z# R. v$ L. Fif(m_proxyans2->Ver != 5 || m_proxyans2->Rep != 0)
% U5 A' t# H! ]* G0 M! R- H{
m_sError = _T("通过代理连接主站不成功!");
ClientSock.Close();
return FALSE;
, [  {/ Z( \1 Y. ?3 z: _0 W$ }: `}
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//通过HTTP方式代理
if( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
; D8 V4 |7 K; u* i/ y, |2 p- y{
m_sError = _T("不能连接到代理服务器!");
ClientSock.Close();
return FALSE;
5 B5 P( [6 G9 |. P6 q6 {0 }* i}
char buff[600];
! m6 a1 x" P7 \3 _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
memset(buff,0,600);
ClientSock.Receive(buff,600);
$ \+ z7 e- ^/ n4 yif(strstr(buff, "HTTP/1.0 200 Connection established") == NULL) //连接不成功
% D# B( g5 U6 y& c! A' {2 `9 I6 [" s{
' k8 W" M6 w& \3 ]' t3 rm_sError = _T("通过代理连接主站不成功!");
ClientSock.Close();
return FALSE;
}
- E8 D3 K% K! m' W0 w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。