[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
. d" f6 A4 A. t) G. dstruct sock4req1
{
) O' v+ V6 T/ Z8 z5 v( m' z- `char VN;
char CD;
" B3 U) d8 G6 E: O2 j5 gunsigned short Port;
5 w% G1 k; k: F, ~) @unsigned long IPAddr;
char other[1];
$ X4 N2 K- ^- O};
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struct sock4ans1
{
2 y$ [  H  D) I0 Qchar VN;
& y3 t% _7 E# ]char CD;
};
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+ Y; m/ [) o$ ?struct sock5req1
* c- g" J5 E" W% t0 P# U& i: `4 |{
char Ver;
  w+ z9 ^( N3 h+ ochar nMethods;
char Methods[255];
; o' L$ F# o2 S7 K' Z- ^7 Q* c};
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  `: q$ m7 {6 T: s: Ustruct sock5ans1
; O# O# N5 E/ W  I- {3 j{
& U/ i# n3 J4 Z' g8 c0 ^2 ~char Ver;
' Z. L$ {" q; Tchar Method;
};
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( N& A6 f- R- r- i" a* `struct sock5req2
{
4 Q' O* Q) ^8 echar Ver;
char Cmd;
3 Z6 T6 h, R8 @7 M  |5 w5 |/ Schar Rsv;
3 j. {# w- L$ C& a1 Lchar Atyp;
char other[1];
};
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# I1 m& O# i1 x+ Qstruct sock5ans2
1 v4 L& Y! {' ~# x$ ~{
) s- U' ~6 i* _$ w; _7 ]char Ver;
/ I/ _, w" D* x1 c( X- b, _char Rep;
# S" j6 G1 g' a* H+ [5 `char Rsv;
char Atyp;
# f0 F1 v4 i! m* t+ ^8 t: T5 }char other[1];
};
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struct authreq
2 p8 }! q' s9 |/ ?/ I0 g2 s{
0 e! x( ?" ]/ mchar Ver;
: [# W2 m  e8 B* ?6 M! W9 fchar Ulen;
9 ]# x' B/ T4 a2 v1 [. E7 r9 Rchar Name[255];
# D$ ^. c0 A8 \5 m4 |+ J& ]char PLen;
0 x" y/ C  ]  x7 _, U* Y$ {+ Kchar Pass[255];
};
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" B% z) q8 x- u- _3 a4 tstruct authans
' t4 O6 u/ P" x{
# {0 \9 y9 \3 Kchar Ver;
, }( v- N  _( f# F: D2 Ochar Status;
};
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5 r& P/ [1 c) i; b  e/ n//通过Socks4方式代理
if( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
7 F5 g- R2 [" e  l& \& M{
" Z2 ?, Q; o4 T' X: H' sm_sError = _T("不能连接到代理服务器!");
# D. J; y, j, p4 t" ZClientSock.Close();
1 U+ |- g0 G( Z6 Oreturn FALSE;
! j0 x1 k. ?  G  |5 y}
char buff[100];
3 I' z2 r; \9 A2 dmemset(buff,0,100);
struct sock4req1 *m_proxyreq;
m_proxyreq = (struct sock4req1 *)buff;
# T5 W( u, U; \. km_proxyreq->VN = 4;
4 J! |0 I- H9 Q  o! w8 Am_proxyreq->CD = 1;
( E# m3 O- m7 U* v/ f9 {% G; wm_proxyreq-&gtort = ntohs(GetPort());
9 N- i6 @6 K* k4 u( m- G0 B/ Qm_proxyreq->IPAddr = inet_addr(GetServerHostName());
ClientSock.Send(buff,9);
struct sock4ans1 *m_proxyans;
m_proxyans = (struct sock4ans1 *)buff;
. K4 [) c/ ^6 X$ b7 O/ T& d% D5 gmemset(buff,0,100);
) V) t( @  l9 WClientSock.Receive(buff,100);
" F* g& @% o6 v- l% _if(m_proxyans->VN != 0 || m_proxyans->CD != 90)
{
% n5 A6 B/ U5 p' V* A5 `$ Sm_sError = _T("通过代理连接主站不成功!");
ClientSock.Close();
return FALSE;
}
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//通过Socks5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!");
ClientSock.Close();
return FALSE;
}
7 f: D9 {8 ^! C: i" Kchar buff[600];
struct sock5req1 *m_proxyreq1;
m_proxyreq1 = (struct sock5req1 *)buff;
m_proxyreq1->Ver = 5;
( o7 M  G" z; R8 `m_proxyreq1->nMethods = 2;
8 c# S/ n3 w7 Y5 V9 cm_proxyreq1->Methods[0] = 0;
m_proxyreq1->Methods[1] = 2;
3 V; Y, p8 X; B- jClientSock.Send(buff,4);
. W8 S6 P- }7 K& O; Ustruct sock5ans1 *m_proxyans1;
m_proxyans1 = (struct sock5ans1 *)buff;
' O' {3 V1 p1 A! e' S1 s! r* p* {memset(buff,0,600);
9 W, X7 ~5 J* A: I: o" E* `ClientSock.Receive(buff,600);
if(m_proxyans1->Ver != 5 || (m_proxyans1->Method!=0 && m_proxyans1->Method!=2))
$ d' _' _# J* Z{
m_sError = _T("通过代理连接主站不成功!");
ClientSock.Close();
7 B3 T* e2 k5 v- J8 Preturn FALSE;
}
if(m_proxyans1->Method == 2)
{
- q( y- a/ b# z0 v6 @* `7 H1 Kint nUserLen = strlen(g_ProxyInfo.m_strProxyUser);
int nPassLen = strlen(g_ProxyInfo.m_strProxyPass);
) r1 t: A: b/ }5 Istruct authreq *m_authreq;
m_authreq = (struct authreq *)buff;
m_authreq->Ver = 1;
m_authreq->Ulen = nUserLen;
: U: R/ u. A3 A# i9 Nstrcpy(m_authreq->Name,g_ProxyInfo.m_strProxyUser);
/ j& `) M; e$ ]) A% K. [2 |m_authreq-&gtLen = nPassLen;
% t, |( a2 |0 rstrcpy(m_authreq-&gtass,g_ProxyInfo.m_strProxyPass);
ClientSock.Send(buff,513);
struct authans *m_authans;
: f8 S: z# J0 S% E$ K9 xm_authans = (struct authans *)buff;
6 l3 a! E2 r+ U- j0 a3 G0 P8 V4 {memset(buff,0,600);
1 b9 n; C( `) S  {8 ^- jClientSock.Receive(buff,600);
if(m_authans->Ver != 1 || m_authans->Status != 0)
# g  r" }- s1 X% g. |, \{
( N$ U$ A7 d4 m' G% V0 g9 ^5 wm_sError = _T("代理服务器用户验证不成功!");
" v! a5 n9 W# i( i# J) @ClientSock.Close();
4 X. O+ U8 T2 ^( F! O' Sreturn FALSE;
8 u* {8 z* u- b+ x}
9 |! v$ ?  l/ R+ D* D}
struct sock5req2 *m_proxyreq2;
' Q* Y- _4 l+ f8 bm_proxyreq2 = (struct sock5req2 *)buff;
% q$ B7 O  ]5 Z2 j! Cm_proxyreq2->Ver = 5;
& Y/ J9 z; M8 R" C2 Fm_proxyreq2->Cmd = 1;
m_proxyreq2->Rsv = 0;
m_proxyreq2->Atyp = 1;
8 r7 ?: {4 C8 Xunsigned long tmpLong = inet_addr(GetServerHostName());
unsigned short port = ntohs(GetPort());
+ \( }; m( R' m* y/ ^memcpy(m_proxyreq2->other,&tmpLong,4);
( P( S. D# m2 b. m/ B9 N3 |7 w! Q6 y) tmemcpy(m_proxyreq2->other+4,&port,2);
ClientSock.Send(buff,sizeof(struct sock5req2)+5);
struct sock5ans2 *m_proxyans2;
7 L& {0 j! N4 l0 d( i6 Pmemset(buff,0,600);
  l6 z+ Y/ _* X2 s3 ]# \- Cm_proxyans2 = (struct sock5ans2 *)buff;
ClientSock.Receive(buff,600);
1 M; E0 o- j% uif(m_proxyans2->Ver != 5 || m_proxyans2->Rep != 0)
( t# p# S* L' A- d$ D4 I5 g{
m_sError = _T("通过代理连接主站不成功!");
ClientSock.Close();
6 }7 K) ~9 }5 l3 Treturn FALSE;
}
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5 z$ ?% H. z% G8 F
! ~4 [- c5 e( C7 j0 u* }//通过HTTP方式代理
" i+ _8 l& D* k5 l3 vif( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
{
m_sError = _T("不能连接到代理服务器!");
5 n( ~3 T3 V% w  l1 D; MClientSock.Close();
6 G% P! n; F' _5 \, T0 greturn FALSE;
; X# m* @- X- @* S* X}
0 J4 B( p% ^0 v3 o0 Bchar buff[600];
sprintf( buff, "%s%s:%d%s","CONNECT ",GetServerHostName(),GetPort()," HTTP/1.1\r\nUser-Agent: MyApp/0.1\r\n\r\n");
, h/ t8 n: k: {' t6 fClientSock.Send(buff,strlen(buff)); //发送请求
, f% i# H1 ~% y% Vmemset(buff,0,600);
4 J) n1 W0 k& U+ s; vClientSock.Receive(buff,600);
if(strstr(buff, "HTTP/1.0 200 Connection established") == NULL) //连接不成功
# t- u5 w4 s! Y6 w# g0 \{
* _( N9 d3 `+ z5 ~" v$ k. im_sError = _T("通过代理连接主站不成功!");
, t  N0 B' M2 c* q5 h2 K- e0 rClientSock.Close();
' e- p+ S/ X/ q% |7 |return FALSE;
}
$ J3 z; d. n0 O. k% j2 w9 i2 D9 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。