[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
struct sock4req1
! @6 ]+ ]& @% f0 Y9 q" e0 G# J# C  d{
6 D( J" J# ?1 h7 Cchar VN;
; {* A5 s5 ]& `char CD;
7 \) p; k9 B) _3 Punsigned short Port;
unsigned long IPAddr;
char other[1];
) Y& R3 p7 M& _};
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struct sock4ans1
{
char VN;
& ]5 T! C' f2 C) ~( W+ Nchar CD;
. \  Y5 J  B6 i8 q: n- S- Z6 M$ j};
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struct sock5req1
{
char Ver;
char nMethods;
" Z4 g! x- g: x, `( b; i$ _char Methods[255];
4 ]. u7 Y9 u9 R  B# O};
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5 S+ g  d) @2 Q$ z5 g: `& k; Ostruct sock5ans1
{
char Ver;
- r) q8 ~. q% |+ Fchar Method;
6 k) N, ^) B, A( Z# m3 ]};
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, \( {$ F) r1 c1 c6 W3 W8 Estruct sock5req2
{
0 u" F. H; c' G. S1 Xchar Ver;
char Cmd;
char Rsv;
char Atyp;
char other[1];
};
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struct sock5ans2
{
5 k# ?7 ^  G3 Nchar Ver;
char Rep;
% t- j# t4 E* Z8 J8 F. n  bchar Rsv;
1 C0 O& s( T2 e+ a# N" Q" achar Atyp;
9 ~9 ~' |: e9 J. e9 A0 Wchar other[1];
};
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+ C2 O  \3 S: k: O( Mstruct authreq
{
1 n4 |9 E  p6 R& P3 ^0 ~6 Gchar Ver;
& W7 X% n" Q. f" N% T; C' Schar Ulen;
char Name[255];
, L0 ?. E7 o9 u" D; u1 P9 ^char PLen;
$ r  m$ R0 y5 q3 ~' Nchar Pass[255];
% S3 ^% G0 ^; w+ d  b& j/ z; {};
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struct authans
{
+ e, ^8 v3 Q3 d4 qchar Ver;
; L0 s, m  W4 ]3 k: Mchar Status;
# a! u$ R! N& b( q! G1 r" e};
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  Q2 I! g& N9 `. `; n//通过Socks4方式代理
# L6 w7 ~* q, Lif( !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();
return FALSE;
" a+ m  D" l$ T}
* ?& c8 y2 ^; o! Z( @. s# U) l) P1 s$ Cchar buff[100];
1 o, v7 S! t& V% \memset(buff,0,100);
6 e# n$ {$ d" B0 [1 ?struct sock4req1 *m_proxyreq;
m_proxyreq = (struct sock4req1 *)buff;
m_proxyreq->VN = 4;
- Q( c; w& [; u6 }5 F) _+ ~m_proxyreq->CD = 1;
2 }8 l% m# w& o( Em_proxyreq-&gtort = ntohs(GetPort());
m_proxyreq->IPAddr = inet_addr(GetServerHostName());
ClientSock.Send(buff,9);
1 m; B# N* u) |1 w* |6 [! a3 ~struct sock4ans1 *m_proxyans;
" `0 ^0 Z) ~( [! U3 Wm_proxyans = (struct sock4ans1 *)buff;
memset(buff,0,100);
ClientSock.Receive(buff,100);
if(m_proxyans->VN != 0 || m_proxyans->CD != 90)
{
; V& p3 y; W. \  _8 q. }m_sError = _T("通过代理连接主站不成功!");
8 j6 N% i  b2 g) O" H6 ~$ Y+ sClientSock.Close();
' J5 }% O5 ]" A# D. B, T  j5 y4 m4 `return FALSE;
# ^, z/ ]7 ?- B" S}
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//通过Socks5方式代理
if( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
; K. i4 ~' m( e1 x5 g{
" E# a. v& Q9 f. km_sError = _T("不能连接到代理服务器!");
) d( c+ r! m4 xClientSock.Close();
return FALSE;
}
! Y, i& v. i6 c4 l* V8 N/ B0 k3 q0 pchar buff[600];
9 Y" G8 b* v! U5 B5 T- A7 p: ~: P2 Tstruct sock5req1 *m_proxyreq1;
6 R- r1 Q. p  z5 b+ o# ^m_proxyreq1 = (struct sock5req1 *)buff;
5 n1 a9 R6 {% K* B2 X5 L" `m_proxyreq1->Ver = 5;
. [. v# M0 M3 U, Z. wm_proxyreq1->nMethods = 2;
m_proxyreq1->Methods[0] = 0;
m_proxyreq1->Methods[1] = 2;
ClientSock.Send(buff,4);
) K: o9 K, v: e* n+ wstruct sock5ans1 *m_proxyans1;
* _8 P9 C& z! Tm_proxyans1 = (struct sock5ans1 *)buff;
% L. H! G- N# s* u  Z3 w9 x8 Cmemset(buff,0,600);
ClientSock.Receive(buff,600);
  V% i$ Y7 q. H1 z1 c" C8 g) wif(m_proxyans1->Ver != 5 || (m_proxyans1->Method!=0 && m_proxyans1->Method!=2))
{
m_sError = _T("通过代理连接主站不成功!");
ClientSock.Close();
return FALSE;
5 p) P% p2 Y" |2 u- x& m}
if(m_proxyans1->Method == 2)
{
int nUserLen = strlen(g_ProxyInfo.m_strProxyUser);
int nPassLen = strlen(g_ProxyInfo.m_strProxyPass);
  Z% p) x0 a# n2 ?8 istruct authreq *m_authreq;
4 z6 g3 B9 c8 L  vm_authreq = (struct authreq *)buff;
# a, f" g9 `( fm_authreq->Ver = 1;
) c9 V* ^/ T4 {2 V. n: h' d) Fm_authreq->Ulen = nUserLen;
strcpy(m_authreq->Name,g_ProxyInfo.m_strProxyUser);
m_authreq-&gtLen = nPassLen;
/ A- Z; N  z' k2 Ostrcpy(m_authreq-&gtass,g_ProxyInfo.m_strProxyPass);
& Y$ w. j8 ^; c$ i' c  t% [1 OClientSock.Send(buff,513);
6 B8 S2 J+ b' d) T: e) Cstruct authans *m_authans;
m_authans = (struct authans *)buff;
3 b3 x5 C- H$ |memset(buff,0,600);
0 t3 ?. e& V6 }0 l1 f, LClientSock.Receive(buff,600);
if(m_authans->Ver != 1 || m_authans->Status != 0)
* P$ A" }2 L0 A# J% R" F) k{
5 U0 z! C7 j2 s* i  qm_sError = _T("代理服务器用户验证不成功!");
ClientSock.Close();
return FALSE;
) k6 H/ S/ H8 c( P1 r}
}
3 g/ k. Z# X4 ?struct sock5req2 *m_proxyreq2;
, f; p4 W1 g) o: g2 Vm_proxyreq2 = (struct sock5req2 *)buff;
m_proxyreq2->Ver = 5;
3 x+ r7 P& t! W% w" im_proxyreq2->Cmd = 1;
m_proxyreq2->Rsv = 0;
9 n' t8 K# m# v( ?: o" Jm_proxyreq2->Atyp = 1;
unsigned long tmpLong = inet_addr(GetServerHostName());
unsigned short port = ntohs(GetPort());
memcpy(m_proxyreq2->other,&tmpLong,4);
  O/ ?" T/ a3 y  Q+ E/ Vmemcpy(m_proxyreq2->other+4,&port,2);
. P4 I' F+ T" g7 a) @  ^ClientSock.Send(buff,sizeof(struct sock5req2)+5);
struct sock5ans2 *m_proxyans2;
memset(buff,0,600);
0 E; x1 ^0 Q$ n; b6 B0 bm_proxyans2 = (struct sock5ans2 *)buff;
ClientSock.Receive(buff,600);
if(m_proxyans2->Ver != 5 || m_proxyans2->Rep != 0)
) s! L8 {2 @3 n: Y1 \4 B{
m_sError = _T("通过代理连接主站不成功!");
  u/ n0 \- @# @( D6 AClientSock.Close();
return FALSE;
}
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! G. l" X/ F/ l; S0 v6 R: D, x
//通过HTTP方式代理
if( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
, K4 {4 |1 Y. ]: V, g& a; A! M{
! t; Q) [" V, x0 U% b7 `! gm_sError = _T("不能连接到代理服务器!");
ClientSock.Close();
/ \1 L- @6 s3 k/ B" oreturn FALSE;
}
char buff[600];
0 ?" r4 N1 |" U1 }( ^, X% T9 Esprintf( 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
8 V0 l' A9 j* C; o6 cmemset(buff,0,600);
ClientSock.Receive(buff,600);
8 Y  M0 Y7 g; }2 C, s8 Bif(strstr(buff, "HTTP/1.0 200 Connection established") == NULL) //连接不成功
" L$ ]( U3 b  E& J{
m_sError = _T("通过代理连接主站不成功!");
ClientSock.Close();
0 a# E& @. S( ^- L$ Creturn FALSE;
, p. X, ?: |" P" ~7 j$ w% K}
  ]# c3 s$ b# z- p- Y9 e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。