[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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% `7 H* G6 n9 E3 d% F+ r4 Q& ^正文
" e7 f: U% U5 l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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% f5 Q6 T' T9 P- Z6 E: f, V  q9 @//使用到的结构
/ ]& R. n; x1 z! Astruct sock4req1
{
: C! R% M, t2 O  S: s$ d# ^- ~char VN;
, E5 J0 X* x, i: Nchar CD;
$ x* E' y  b' @* N4 ounsigned short Port;
, g: W3 K# ^2 Q  `unsigned long IPAddr;
; j" H1 e" [1 B6 J) _9 cchar other[1];
};
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+ B3 @( Q: y/ m' L8 L7 o5 v6 r* Kstruct sock4ans1
{
, D. U- U, b. {& e# P5 C# O3 echar VN;
char CD;
};
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struct sock5req1
7 V; G$ M8 |6 p{
char Ver;
char nMethods;
char Methods[255];
# C) F) S9 e! x+ s};
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; O# M. Y0 H! v% \/ C( ystruct sock5ans1
3 ^9 b& Z* e. I7 ]* y/ @1 k) `{
char Ver;
  v7 N/ Q8 T' ^7 `char Method;
6 Z+ \  @7 e0 o$ [$ @};
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struct sock5req2
{
char Ver;
char Cmd;
char Rsv;
. N$ [9 U2 ?& b6 d. b! gchar Atyp;
$ c" K. V3 V' o8 hchar other[1];
};
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struct sock5ans2
* V% ]) b9 \% [  p1 K! n{
char Ver;
6 q  @# V( ^1 v$ |8 M) Wchar Rep;
. r1 W% [9 ]6 f! d$ D7 Ochar Rsv;
. ^$ |+ h9 A1 p; W/ U) U. hchar Atyp;
char other[1];
7 L7 p! i; f2 {2 {+ ~5 ?};
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struct authreq
8 P2 b! N. W3 c9 c/ R# J8 V{
char Ver;
! X% u, s0 z( A/ b3 _char Ulen;
' i- r1 K; @. [7 N2 K, ]0 c# q# Vchar Name[255];
; Q0 d2 C# ~7 z4 B/ `" L( r  ~# A6 q8 Zchar PLen;
char Pass[255];
};
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struct authans
! s% e. }# n% T{
char Ver;
char Status;
% r) I( _6 h: a& w};
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- Y9 R6 M- O9 B9 y6 Y7 |7 r//通过Socks4方式代理
if( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
{
0 w: }# w( e- pm_sError = _T("不能连接到代理服务器!");
ClientSock.Close();
% I& u: O2 l: F, Ireturn FALSE;
$ u. s  k6 R: [7 l. f}
char buff[100];
8 O1 N) r  V# [# V( {) z; S0 M7 bmemset(buff,0,100);
7 n* T( z7 Z( |; c! |struct sock4req1 *m_proxyreq;
1 G' r5 S* j4 L2 P  Om_proxyreq = (struct sock4req1 *)buff;
m_proxyreq->VN = 4;
) ~5 I8 D( O) h( @. Z; V+ x' o" Mm_proxyreq->CD = 1;
m_proxyreq-&gtort = ntohs(GetPort());
# N% X) q3 r1 s7 E. \% Xm_proxyreq->IPAddr = inet_addr(GetServerHostName());
" A5 A( M& ~# ]$ i  H  eClientSock.Send(buff,9);
3 A0 d4 L" V0 m4 r7 z, L9 }) ~struct sock4ans1 *m_proxyans;
m_proxyans = (struct sock4ans1 *)buff;
7 i- O( e9 U! T, A, _& E( Kmemset(buff,0,100);
ClientSock.Receive(buff,100);
if(m_proxyans->VN != 0 || m_proxyans->CD != 90)
{
6 f: J+ b. ~9 [: ?, c, ^, I- X* _m_sError = _T("通过代理连接主站不成功!");
" a6 ^5 N( m" O/ M( R- HClientSock.Close();
return FALSE;
}
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0 I; p, Q- W; }! t
* |$ U$ t( @+ ~, y$ t7 `wwww.chin aitpower.comJZM2iofLWRmFIxU68q4I3qxHU

//通过Socks5方式代理
2 f' h( W( R1 k0 Rif( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
{
$ \- Z% e/ c+ C* Em_sError = _T("不能连接到代理服务器!");
! N3 u- K, f8 L9 ~) }8 S& D# pClientSock.Close();
return FALSE;
4 L: m: s' b. z: r" v% [# ~}
+ Z& D4 d/ f7 O7 achar buff[600];
3 f% F1 \+ h: C4 u/ D- `' `struct sock5req1 *m_proxyreq1;
m_proxyreq1 = (struct sock5req1 *)buff;
9 k- a6 E, F: S3 E5 L% `6 ~0 gm_proxyreq1->Ver = 5;
m_proxyreq1->nMethods = 2;
% y, m' f' n* q! @+ R9 ]4 J5 A) \/ Km_proxyreq1->Methods[0] = 0;
, v8 S0 y* t+ p) j  Y9 wm_proxyreq1->Methods[1] = 2;
ClientSock.Send(buff,4);
struct sock5ans1 *m_proxyans1;
m_proxyans1 = (struct sock5ans1 *)buff;
memset(buff,0,600);
( a4 u9 r8 u9 O" V# f+ q) B. m; ~1 |0 cClientSock.Receive(buff,600);
8 P, p' K  @6 Q7 I# Zif(m_proxyans1->Ver != 5 || (m_proxyans1->Method!=0 && m_proxyans1->Method!=2))
7 P7 I; Q% R- p6 }! N  U) @{
m_sError = _T("通过代理连接主站不成功!");
+ n% j* P! K, g: t) o# o1 v! r9 QClientSock.Close();
7 Z6 z% Y+ |/ t) u% Creturn FALSE;
}
# z2 z2 Q' o9 \8 q  O, ~- aif(m_proxyans1->Method == 2)
: d( h. `3 [6 P. K9 ?{
int nUserLen = strlen(g_ProxyInfo.m_strProxyUser);
int nPassLen = strlen(g_ProxyInfo.m_strProxyPass);
struct authreq *m_authreq;
7 k( b" N8 s& W! x7 Vm_authreq = (struct authreq *)buff;
m_authreq->Ver = 1;
m_authreq->Ulen = nUserLen;
3 L) J: r5 a& R/ F! sstrcpy(m_authreq->Name,g_ProxyInfo.m_strProxyUser);
: J, V9 Y# c. ~8 o+ [" N/ Ym_authreq-&gtLen = nPassLen;
strcpy(m_authreq-&gtass,g_ProxyInfo.m_strProxyPass);
/ b+ V, i0 @$ j6 I4 rClientSock.Send(buff,513);
% j, A5 [- m. Y* mstruct authans *m_authans;
& C/ T" Q* v; E+ {) L; R$ ~9 Q' Zm_authans = (struct authans *)buff;
memset(buff,0,600);
3 A; ?" R. u) Y7 kClientSock.Receive(buff,600);
2 S3 Y' M% K2 v! t  Tif(m_authans->Ver != 1 || m_authans->Status != 0)
{
m_sError = _T("代理服务器用户验证不成功!");
ClientSock.Close();
3 @7 f* W& }- l) L, f9 Nreturn FALSE;
}
" E4 y' I- C$ g: d' i2 ]/ m}
6 `% c' @) M8 D3 V% f0 P# Ustruct sock5req2 *m_proxyreq2;
8 t; z7 r* }8 ]6 ]+ Y6 |3 s! Pm_proxyreq2 = (struct sock5req2 *)buff;
9 h2 }4 Y( \# P+ r! T! em_proxyreq2->Ver = 5;
- h3 V. o* J4 M1 V1 Om_proxyreq2->Cmd = 1;
) ]9 z5 C0 z4 \- t" X" Bm_proxyreq2->Rsv = 0;
+ x  d" v& ]+ c5 Y  Gm_proxyreq2->Atyp = 1;
unsigned long tmpLong = inet_addr(GetServerHostName());
unsigned short port = ntohs(GetPort());
# e  }; d& ?$ h8 {( amemcpy(m_proxyreq2->other,&tmpLong,4);
memcpy(m_proxyreq2->other+4,&port,2);
: Q% C; ~: p: M" N8 ]2 u/ [ClientSock.Send(buff,sizeof(struct sock5req2)+5);
+ a8 w# ^- u; S$ ?2 estruct sock5ans2 *m_proxyans2;
6 K8 n$ t2 ]4 F, g2 ?% D* @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!");
  a6 E+ D" J, c0 p4 Q! n; oClientSock.Close();
& \6 S* f* A2 T) z7 Areturn FALSE;
}
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4 [0 [1 r# c7 @. ?
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, N, U# m9 f( t' w: h/ B, }5 x
//通过HTTP方式代理
4 E2 o$ ^& e8 \, x5 `  ~3 v' W4 sif( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
{
" d. x* o1 I0 H0 v: u( E* z" Fm_sError = _T("不能连接到代理服务器!");
ClientSock.Close();
( g. @( R9 s+ ~: w8 s! u6 j' xreturn 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
5 f! n9 _- p$ @: e1 o4 t! O5 lmemset(buff,0,600);
ClientSock.Receive(buff,600);
if(strstr(buff, "HTTP/1.0 200 Connection established") == NULL) //连接不成功
4 h0 Q2 B5 A- l& m( N# D{
m_sError = _T("通过代理连接主站不成功!");
ClientSock.Close();
2 W; m# C; Z: A# Ereturn 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。