[收藏]穿透代理服务器编程

天云上人

  作者 allfresh
( _+ _5 i3 Q) j( A5 V文章原始出处 www.allfresh.net/program/proxy.htm
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; V$ j. w& A8 g; \# ]" `4 e正文
, ~# `, D- y0 Q! X7 F4 t+ p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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( {3 f  X/ s- l# ~6 t7 R3 j( R: n+ E//使用到的结构
6 G1 c! j4 Y+ D/ f* C3 ?struct sock4req1
{
$ Z  u8 ]7 E  R# J$ |0 C# Lchar VN;
, h( L( A8 g8 x7 _& dchar CD;
6 z+ d+ w8 l+ h& }6 ?. o1 cunsigned short Port;
unsigned long IPAddr;
char other[1];
8 E1 e* A  `4 K; g2 X1 h* f};
1 n; ]' L% M1 \4 J1 H" Twwww.chin aitpower.comJZM2iofLWRmFIxU68q4I3qxHU
4 Z5 K* D2 m; }5 V) Ustruct sock4ans1
{
+ H" @0 {. K% G5 B0 |char VN;
; z5 d; s! {! a6 t: nchar CD;
/ ?4 O5 z5 O& W+ u3 D};
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- T7 D! F4 g* O  Z: L$ P& Sstruct sock5req1
  c$ R6 S6 F- E* M# k{
char Ver;
char nMethods;
1 ?- p" e7 @/ I5 y2 ]: G9 a6 v1 Pchar Methods[255];
4 U2 b- Q) U3 ]. s( F6 X};
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struct sock5ans1
2 G- \1 ]$ M( }" C1 e: u/ ~" E: o- y{
9 b. X! ?) i$ U5 ^char Ver;
char Method;
) E4 s% y: S5 x4 a$ E};
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( ?: V8 Z1 r6 z& Lstruct sock5req2
4 {8 E. H" x; l$ B/ d) g& f# k5 A{
char Ver;
; E" b/ Z* g! X+ ~+ N) S& \char Cmd;
char Rsv;
2 M; o( {: ?! u) j) P! Q- achar Atyp;
char other[1];
};
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9 g+ }% \( n, D& P  e7 q1 |struct sock5ans2
: h- {: H* x$ B' {2 |# B- O{
0 [9 q! ~( |: c0 G1 @4 L* hchar Ver;
6 H- {2 `) l5 [3 Bchar Rep;
8 N+ A& F7 C! w1 R. g, M. Dchar Rsv;
char Atyp;
. R- ^) i6 e( ^+ Ychar other[1];
};
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struct authreq
( _$ j, B# m1 [' I0 Z{
' {1 n* U/ }! Z: s. wchar Ver;
char Ulen;
) U0 w4 d% U6 ~7 Ochar Name[255];
* s. }' E" ~! ]; h6 C9 Wchar PLen;
9 T# J3 `! R  i4 s  I7 jchar Pass[255];
9 P- H# \( O" A( ?, b; S* v, q};
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struct authans
{
; @( t7 D) {& H; y& O# A* bchar Ver;
* j+ c7 r- D! U+ k8 Qchar Status;
# _% a9 z  F' ^2 _; S};
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3 U( a% `9 T8 D//通过Socks4方式代理
# {& M$ }! L, s  q' h' ^0 c( qif( !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;
}
char buff[100];
) N: G1 G  }' Q; \5 `memset(buff,0,100);
struct sock4req1 *m_proxyreq;
" L! P8 q: H6 ?, P& A3 l& x, {m_proxyreq = (struct sock4req1 *)buff;
m_proxyreq->VN = 4;
6 E, I" A; e: sm_proxyreq->CD = 1;
5 J4 L5 Y3 Q7 Z5 T7 ]. Q; Jm_proxyreq-&gtort = ntohs(GetPort());
m_proxyreq->IPAddr = inet_addr(GetServerHostName());
ClientSock.Send(buff,9);
struct sock4ans1 *m_proxyans;
! U4 s% f! T, r, U. ^" \" W9 {/ j. Gm_proxyans = (struct sock4ans1 *)buff;
memset(buff,0,100);
! W8 d& G' x3 K: }. F# pClientSock.Receive(buff,100);
if(m_proxyans->VN != 0 || m_proxyans->CD != 90)
$ e. Q) C+ o* T' {9 B+ [{
7 a! m- ^. s7 M, H9 c% \3 ]$ ^m_sError = _T("通过代理连接主站不成功!");
1 ~- n! `$ Z* [8 }; L  ?6 AClientSock.Close();
return FALSE;
6 y% Y2 m% w- K$ q/ b' n, z}
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9 B2 L/ o' q. L9 N
0 c$ `4 `! |1 K% {' S//通过Socks5方式代理
/ s' s/ o5 L5 b. [0 ~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();
+ F2 ~( ~+ d/ s( F( \4 f+ \$ ?return FALSE;
# N4 k! R% E7 \# ~, B+ c# h}
char buff[600];
! ~, C/ A1 K4 d; u$ |; Qstruct sock5req1 *m_proxyreq1;
: |6 ?6 N; X  t! e$ ]m_proxyreq1 = (struct sock5req1 *)buff;
m_proxyreq1->Ver = 5;
m_proxyreq1->nMethods = 2;
, g- X; @8 {0 F/ j/ a7 Z: `: `8 Cm_proxyreq1->Methods[0] = 0;
/ ?- J7 A# a1 w( b1 `) ^" a6 P# Om_proxyreq1->Methods[1] = 2;
2 b$ Z, }7 Z9 b# {( D$ x' rClientSock.Send(buff,4);
struct sock5ans1 *m_proxyans1;
m_proxyans1 = (struct sock5ans1 *)buff;
; j7 |8 `2 o& p1 mmemset(buff,0,600);
ClientSock.Receive(buff,600);
if(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;
}
9 \) |3 @3 ~0 v/ R9 B( D" ^+ qif(m_proxyans1->Method == 2)
& h, t0 l/ a2 l& C7 @3 i* k{
+ B1 l0 g- N8 ~, fint nUserLen = strlen(g_ProxyInfo.m_strProxyUser);
+ t) W, p7 Z4 m6 Oint nPassLen = strlen(g_ProxyInfo.m_strProxyPass);
3 \! p: I# {$ f: istruct authreq *m_authreq;
m_authreq = (struct authreq *)buff;
m_authreq->Ver = 1;
3 ]4 o5 E3 ~  P, m+ gm_authreq->Ulen = nUserLen;
9 ^: |4 ~2 F' C8 C# r" [strcpy(m_authreq->Name,g_ProxyInfo.m_strProxyUser);
m_authreq-&gtLen = nPassLen;
strcpy(m_authreq-&gtass,g_ProxyInfo.m_strProxyPass);
ClientSock.Send(buff,513);
6 s8 F# C' s/ Q6 |/ Bstruct authans *m_authans;
m_authans = (struct authans *)buff;
2 P" h4 v9 t7 g  ]- i6 Cmemset(buff,0,600);
! L# g4 U8 C6 T6 Q+ {6 [ClientSock.Receive(buff,600);
( C3 _  Q7 c/ l* ^' K) ^if(m_authans->Ver != 1 || m_authans->Status != 0)
9 w+ o0 o) J+ m; P' L0 p% j{
m_sError = _T("代理服务器用户验证不成功!");
ClientSock.Close();
. ^. x6 ?5 ^! b' R5 V+ ^return FALSE;
}
}
struct sock5req2 *m_proxyreq2;
m_proxyreq2 = (struct sock5req2 *)buff;
, }3 F- r+ s. H1 um_proxyreq2->Ver = 5;
* i( Y, T3 q5 V, V5 h3 gm_proxyreq2->Cmd = 1;
! m: t5 Z4 H: w2 ym_proxyreq2->Rsv = 0;
m_proxyreq2->Atyp = 1;
& S4 ~* V6 h, o" y4 Q* |9 ?" wunsigned long tmpLong = inet_addr(GetServerHostName());
. _! Z! X1 {6 kunsigned short port = ntohs(GetPort());
8 k( L! S' O: }0 P; r4 z7 cmemcpy(m_proxyreq2->other,&tmpLong,4);
memcpy(m_proxyreq2->other+4,&port,2);
, c1 ?; i2 ~3 \' r0 w& _2 m+ I4 QClientSock.Send(buff,sizeof(struct sock5req2)+5);
struct sock5ans2 *m_proxyans2;
$ z( |( O; u+ ?. g7 g- _memset(buff,0,600);
m_proxyans2 = (struct sock5ans2 *)buff;
' g" m3 ^* O( m) x3 O& I# z& @ClientSock.Receive(buff,600);
1 @1 t( A. ]9 C5 F' Xif(m_proxyans2->Ver != 5 || m_proxyans2->Rep != 0)
$ R+ p: e- n" l8 n, ~{
m_sError = _T("通过代理连接主站不成功!");
8 p- E7 Y4 w% y, T; eClientSock.Close();
return FALSE;
  W7 }- b8 t2 `2 m}
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wwww.chin aitpower.comJZM2iofLWRmFIxU68q4I3qxHU
9 J, c1 y# v) m8 E/ l" d& s
//通过HTTP方式代理
( C# x) r; B! u+ u$ s8 Vif( !ClientSock.Connect( g_ProxyInfo.m_strProxyIP,g_ProxyInfo.m_nProxyPort) )
7 P( m( I6 F* |) |: A+ \0 ^{
m_sError = _T("不能连接到代理服务器!");
ClientSock.Close();
return FALSE;
}
# V! M2 O% Z  V6 c/ C. |) dchar buff[600];
' b, p) U. [. `! a! ^1 i+ Vsprintf( buff, "%s%s:%d%s","CONNECT ",GetServerHostName(),GetPort()," HTTP/1.1\r\nUser-Agent: MyApp/0.1\r\n\r\n");
" D3 t) u( y! H, A+ a  \# Q  kClientSock.Send(buff,strlen(buff)); //发送请求
; B: \- K  [; U6 j/ |memset(buff,0,600);
ClientSock.Receive(buff,600);
if(strstr(buff, "HTTP/1.0 200 Connection established") == NULL) //连接不成功
6 g5 f4 Z' I0 p, m  A( O{
m_sError = _T("通过代理连接主站不成功!");
ClientSock.Close();
return 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。