[收藏]穿透代理服务器编程

天云上人

  作者 allfresh
# X0 B- |, p9 {' W8 N9 Q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
$ E. j) Z% f2 Bstruct sock4req1
) F/ l3 R: ^) i; Z% z$ S  F{
char VN;
4 m, V- c( g& j2 d6 bchar CD;
unsigned short Port;
6 V0 {% ^/ j& g, f6 ^unsigned long IPAddr;
char other[1];
: k" Z; o( }& y" V};
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struct sock4ans1
{
) z6 E6 F3 X  u  ?4 p+ H7 Xchar VN;
& ~8 v, O, |1 B  dchar CD;
};
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struct sock5req1
{
char Ver;
1 L) l6 \& e# q% F5 M& H5 x7 pchar nMethods;
char Methods[255];
};
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& Y) ]3 T$ J2 {' Fstruct sock5ans1
{
/ n: r. a4 X7 x6 H( U. c4 `char Ver;
0 p1 O! {# j, N% f1 schar Method;
3 n: \! n3 C! ^/ Q};
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struct sock5req2
{
char Ver;
char Cmd;
8 E4 ]4 Z+ ]2 Q- U7 s0 Gchar Rsv;
char Atyp;
char other[1];
};
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struct sock5ans2
/ z7 G! H' G) x4 X- ]{
( P& D$ p" J$ y) ?' |2 Vchar Ver;
' _/ }7 N7 b' |# F. \6 Dchar Rep;
) B6 y4 z, n0 I8 Vchar Rsv;
3 s6 D* J& A, D* q+ Xchar Atyp;
char other[1];
8 H6 S7 I: D3 o1 E. [$ c( e0 J- [9 S};
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struct authreq
: Y: J; x1 }( N( b: T{
4 }! y/ r' n  p/ o, Qchar Ver;
char Ulen;
char Name[255];
, V* e5 E5 L8 m3 D; j" m9 t: ?7 \char PLen;
char Pass[255];
};
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- N0 T. L1 x6 D" g# Astruct authans
{
char Ver;
' F) W4 c! J) H. m6 s: k  Gchar Status;
% Z. R( f- e+ w4 P) q};
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//通过Socks4方式代理
  a3 g- s( ]( M; N4 e' v. R4 sif( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
. P; Z) W- p+ Y0 Z5 d6 U- B{
m_sError = _T("不能连接到代理服务器!");
: V6 F0 t- T3 P$ M# KClientSock.Close();
return FALSE;
}
char buff[100];
memset(buff,0,100);
" @  S( W# X1 N" d9 k" r  Jstruct sock4req1 *m_proxyreq;
) A6 |! n( }3 |6 o. o' ~* a) D9 Fm_proxyreq = (struct sock4req1 *)buff;
m_proxyreq->VN = 4;
; V# R9 g$ L1 e  r& R8 Cm_proxyreq->CD = 1;
5 o' \- B/ A8 Rm_proxyreq-&gtort = ntohs(GetPort());
3 W2 g! ]/ Z& L# P0 R" P& ~m_proxyreq->IPAddr = inet_addr(GetServerHostName());
9 \  {- d/ I) }. U: v7 h* fClientSock.Send(buff,9);
) G3 V, l$ p) ostruct sock4ans1 *m_proxyans;
m_proxyans = (struct sock4ans1 *)buff;
memset(buff,0,100);
ClientSock.Receive(buff,100);
if(m_proxyans->VN != 0 || m_proxyans->CD != 90)
1 y$ T+ n1 {: q4 {# D{
' b6 p+ Y$ b2 j5 d9 x4 Em_sError = _T("通过代理连接主站不成功!");
: b$ J, A& U; i% I8 _" j. vClientSock.Close();
return FALSE;
}
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- L3 e8 Z  U; v/ [9 s. v3 C2 a& u
1 y. ]  D& e7 }8 A//通过Socks5方式代理
; o: q) Q% G, V0 bif( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
- x, D) w: F* X5 A{
$ K+ Q/ s8 e# m3 }- Um_sError = _T("不能连接到代理服务器!");
ClientSock.Close();
1 V% D- x% u  Z) E* U1 r1 I, _return FALSE;
}
* W1 n% q/ A* ]7 L( L  n) ^char buff[600];
struct sock5req1 *m_proxyreq1;
7 \9 O# ^! w5 ^7 ^# y4 @1 z+ wm_proxyreq1 = (struct sock5req1 *)buff;
' C0 b% p7 a' b$ xm_proxyreq1->Ver = 5;
m_proxyreq1->nMethods = 2;
; K4 q  c, G! X; w! x- l. ym_proxyreq1->Methods[0] = 0;
m_proxyreq1->Methods[1] = 2;
2 j9 `* q$ Y" b' fClientSock.Send(buff,4);
+ e3 I' p8 F0 L- [& A3 P; Ostruct sock5ans1 *m_proxyans1;
  `+ J7 Z$ n( um_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))
{
! P8 c9 Q& ^7 H7 o  s3 zm_sError = _T("通过代理连接主站不成功!");
ClientSock.Close();
: ^" }4 z8 Y& s  ^( T$ j7 [+ ]return FALSE;
}
' W0 S6 k  |6 m+ ^5 x; nif(m_proxyans1->Method == 2)
8 f! i% e4 y, }" W{
, n. l& P4 s- D! nint nUserLen = strlen(g_ProxyInfo.m_strProxyUser);
int nPassLen = strlen(g_ProxyInfo.m_strProxyPass);
struct authreq *m_authreq;
m_authreq = (struct authreq *)buff;
. Y( ~  `' t. ?! N3 T# \m_authreq->Ver = 1;
, q1 S4 o7 p2 N) t/ ?m_authreq->Ulen = nUserLen;
strcpy(m_authreq->Name,g_ProxyInfo.m_strProxyUser);
m_authreq-&gtLen = nPassLen;
% T! `4 s& q% I8 q' u% P6 E3 Dstrcpy(m_authreq-&gtass,g_ProxyInfo.m_strProxyPass);
ClientSock.Send(buff,513);
) _) T& \0 I6 d' ^struct authans *m_authans;
  K' |) ^3 `. |1 S( um_authans = (struct authans *)buff;
memset(buff,0,600);
! X, B. ?# N9 Z' b% gClientSock.Receive(buff,600);
if(m_authans->Ver != 1 || m_authans->Status != 0)
{
' r3 I  h4 m. Wm_sError = _T("代理服务器用户验证不成功!");
# a, D2 o. W5 R/ bClientSock.Close();
return FALSE;
' S9 N7 C# D7 d+ G" S}
) o  t$ Z$ |7 t$ s  v% w}
, ?, `" I, r% `# A! R3 Tstruct sock5req2 *m_proxyreq2;
- L( h; z% ?& rm_proxyreq2 = (struct sock5req2 *)buff;
$ P" x  ]+ B2 tm_proxyreq2->Ver = 5;
7 \  X# m  k' d1 z: J$ `m_proxyreq2->Cmd = 1;
2 N6 t3 P* H4 y2 w7 y7 ^, \m_proxyreq2->Rsv = 0;
m_proxyreq2->Atyp = 1;
unsigned long tmpLong = inet_addr(GetServerHostName());
: B  W) z3 e/ Z8 q9 lunsigned short port = ntohs(GetPort());
memcpy(m_proxyreq2->other,&tmpLong,4);
7 p8 Y( K$ [6 V8 _8 L! Mmemcpy(m_proxyreq2->other+4,&port,2);
0 B4 Z9 R. W3 r. wClientSock.Send(buff,sizeof(struct sock5req2)+5);
struct sock5ans2 *m_proxyans2;
8 w- i& k$ D7 l9 z, f9 V4 ~( }memset(buff,0,600);
m_proxyans2 = (struct sock5ans2 *)buff;
2 p9 U1 l# A# X$ ~3 @. \ClientSock.Receive(buff,600);
! a& E: b+ u$ Z( k- pif(m_proxyans2->Ver != 5 || m_proxyans2->Rep != 0)
{
* V# J- F9 l; ]; h2 r' z0 wm_sError = _T("通过代理连接主站不成功!");
ClientSock.Close();
+ n1 K! g4 b% ^) @, mreturn FALSE;
* `& Y; n1 N3 V) m( O2 J- b}
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//通过HTTP方式代理
if( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
{
m_sError = _T("不能连接到代理服务器!");
& `. X3 `* d+ XClientSock.Close();
return FALSE;
4 ~! E% a- P& V5 A}
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");
4 e1 S, k6 v8 T3 V, u% f: MClientSock.Send(buff,strlen(buff)); //发送请求
memset(buff,0,600);
ClientSock.Receive(buff,600);
2 m7 X/ _9 ~3 Q$ N* fif(strstr(buff, "HTTP/1.0 200 Connection established") == NULL) //连接不成功
3 N# N8 J* y# b' c; N{
m_sError = _T("通过代理连接主站不成功!");
) \9 T  s$ S; L: H0 y- gClientSock.Close();
return FALSE;
( T6 c8 a1 x3 ^* f}
2 X" I- v" j/ \. p( H$ a1 [8 X; d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。