2 Basic object-oriented network functions
3 Copyright (C) 2010-2018 MegaBrutal
5 This unit is free software: you can redistribute it and/or modify
6 it under the terms of the GNU Lesser General Public License as published by
7 the Free Software Foundation, either version 3 of the License, or
8 (at your option) any later version.
10 This unit is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>.
21 This unit provides an object-oriented interface to manage TCP/IPv4
24 TTCPConnection - provides methods for sending/receiving buffers through
25 the connection, and some support for text-based communication.
27 TTCPRFCConnection - in addition to TTCPConnection, it provides methods
28 to send/receive RFC-style commands and responses.
30 TTCPListener - opens a port to listen on, and accepts incoming connections
31 through it. Override its "HandleClient" method to serve connected
40 uses Classes
, Sockets
, SocketUtils
, SysUtils
, DNSResolve
, NetRFC
, Common
;
44 { Connection feature requests: }
46 NET_TCP_RFCSUPPORT
= 1;
48 { Default socket timeout: }
49 DEF_SOCK_TIMEOUT
= 5 * 60000; { 5 minutes. }
54 TTCPConnection
= class
55 constructor Create
; overload
;
56 constructor Create(const HostName
: string; Port
: word); overload
;
57 constructor Create(Socket
: socket
); overload
;
58 destructor Destroy
; override;
64 SrcSockAddr
, DstSockAddr
: TSockAddr
;
66 function SetBindAddress(const HostName
: string): boolean;
67 function Connect(const HostName
: string; Port
: word): boolean;
69 procedure ReverseDNSLookup
;
70 function VerifyFCrDNS
: boolean;
71 procedure SetSockTimeOut(TimeOut
: DWord
);
72 function ReadBuffer(PtrBuffer
: pointer; Len
: size_t
): ssize_t
;
73 function WriteBuffer(PtrBuffer
: pointer; Len
: size_t
): ssize_t
;
74 function ReadLn(var Line
: string): boolean;
75 function WriteLn(const Line
: string): boolean;
76 property Connected
: boolean read FConnected
;
77 property Socket
: socket read FSocket
;
78 property HostIP
: TIPNamePair read FHostIP
;
79 property SockTimeOut
: DWord read FSockTimeOut write SetSockTimeOut
;
82 TTCPRFCConnection
= class(TTCPConnection
)
84 function ReadCommand(var Command
: shortstring
; var Prms
: string): boolean;
85 function ReadResponse(Response
: TRFCReply
): boolean;
86 function SendCommand(Command
: shortstring
): boolean; overload
;
87 function SendCommand(Command
: shortstring
; Prms
: string): boolean; overload
;
88 function SendResponse(Response
: TRFCReply
): boolean;
92 TTCPAcceptHandler
= procedure(Connection
: TTCPConnection
) of object;
94 TTCPAcceptor
= class(TThread
)
95 constructor Create(Handler
: TTCPAcceptHandler
; TCPConnection
: TTCPConnection
);
97 FHandler
: TTCPAcceptHandler
;
98 FTCPConnection
: TTCPConnection
;
99 procedure Execute
; override;
102 TTCPListener
= class(TThread
)
103 constructor Create(const Address
: string; Port
: word; FeatureRequest
: word);
104 {destructor Destroy; override;}
106 FFeatureRequest
: word;
107 FListenAddress
: string;
109 FListenSocket
: socket
;
111 procedure HandleClient(Connection
: TTCPConnection
); virtual; abstract;
112 procedure Execute
; override;
114 property ListenAddress
: string read FListenAddress
;
115 property ListenPort
: word read FListenPort
;
116 function GetSockAddrStr
: string;
117 function StartListen
: boolean;
118 procedure StopListen
;
126 constructor TTCPConnection
.Create
;
127 { Create an instance, but don't connect to anywhere yet. }
132 FSockTimeOut
:= DEF_SOCK_TIMEOUT
;
133 FillChar(SrcSockAddr
, SizeOf(SrcSockAddr
), 0);
134 FillChar(DstSockAddr
, SizeOf(DstSockAddr
), 0);
137 constructor TTCPConnection
.Create(const HostName
: string; Port
: word);
138 { Connect to the given port on the given hostname. }
141 Connect(HostName
, Port
);
144 constructor TTCPConnection
.Create(Socket
: socket
);
145 { Use an already connected socket. }
146 var ssocklen
, dsocklen
: TSockLen
;
150 ssocklen
:= SizeOf(SrcSockAddr
);
151 dsocklen
:= SizeOf(DstSockAddr
);
152 fpgetsockname(FSocket
, @SrcSockAddr
, @ssocklen
);
153 fpgetpeername(FSocket
, @DstSockAddr
, @dsocklen
);
154 FHostIP
:= TIPNamePair
.Create('', NetAddrToStr(DstSockAddr
.sin_addr
));
158 destructor TTCPConnection
.Destroy
;
160 if FConnected
then Disconnect
;
165 constructor TTCPAcceptor
.Create(Handler
: TTCPAcceptHandler
; TCPConnection
: TTCPConnection
);
166 { Start a connection handler on a distinct thread. }
169 FTCPConnection
:= TCPConnection
;
170 FreeOnTerminate
:= true;
171 inherited Create(false);
175 constructor TTCPListener
.Create(const Address
: string; Port
: word; FeatureRequest
: word);
177 FListenAddress
:= Address
;
179 FFeatureRequest
:= FeatureRequest
;
180 FreeOnTerminate
:= false;
181 FillChar(SockAddr
, SizeOf(SockAddr
), 0);
182 inherited Create(true);
186 function TTCPConnection
.SetBindAddress(const HostName
: string): boolean;
187 var GAIResult
: TGAIResult
;
189 GAIResult
:= ResolveHost(HostName
);
190 if GAIResult
.GAIError
= 0 then begin
191 SrcSockAddr
:= GAIResult
.AddrInfo
^.ai_addr
^;
199 function TTCPConnection
.Connect(const HostName
: string; Port
: word): boolean;
200 { Resolves the given hostname, and tries to connect it on the given port. }
201 var GAIResult
: TGAIResult
;
203 FSocket
:= fpSocket(af_inet
, sock_stream
, 0);
204 if (FSocket
<> -1) then begin
205 if (SrcSockAddr
.sin_addr
.s_addr
= 0) or (fpBind(FSocket
, @SrcSockAddr
, SizeOf(SrcSockAddr
)) = 0) then begin
206 GAIResult
:= ResolveHost(HostName
);
207 if GAIResult
.GAIError
= 0 then begin
208 DstSockAddr
:= GAIResult
.AddrInfo
^.ai_addr
^;
209 DstSockAddr
.sin_port
:= htons(Port
);
211 if DstSockAddr
.sin_addr
.s_addr
<> 0 then
212 { Try to initiate connection. }
213 FConnected
:= fpConnect(FSocket
, @DstSockAddr
, SizeOf(DstSockAddr
)) <> -1;
215 if FConnected
then begin
216 FHostIP
:= TIPNamePair
.Create(HostName
, NetAddrToStr(DstSockAddr
.sin_addr
));
217 SetSockTimeOut(FSockTimeOut
);
220 CloseSocket(FSocket
);
229 procedure TTCPConnection
.Disconnect
;
231 fpShutdown(FSocket
, 2);
232 CloseSocket(FSocket
);
238 procedure TTCPConnection
.ReverseDNSLookup
;
239 { Performs a reverse DNS lookup, and updates the HostIP structure. }
240 var NHostIP
: TIPNamePair
;
242 if FConnected
then begin
243 NHostIP
:= TIPNamePair
.Create(ResolveIP(@DstSockAddr
), FHostIP
.IP
);
249 function TTCPConnection
.VerifyFCrDNS
: boolean;
250 var GAIResult
: TGAIResult
; ai
: PAddrInfo
;
253 GAIResult
:= ResolveHost(HostIP
.Name
);
254 if GAIResult
.GAIError
= 0 then begin
255 ai
:= GAIResult
.AddrInfo
;
256 { One of the addresses must match. }
257 while (ai
<> nil) and not Result
do begin
258 Result
:= NetAddrToStr(ai
^.ai_addr
^.sin_addr
) = HostIP
.IP
;
264 procedure TTCPConnection
.SetSockTimeOut(TimeOut
: DWord
);
266 FSockTimeOut
:= TimeOut
;
267 if Connected
then begin
268 fpSetSockOpt(FSocket
, SOL_SOCKET
, SO_RCVTIMEO
, @FSockTimeOut
, SizeOf(FSockTimeOut
));
269 fpSetSockOpt(FSocket
, SOL_SOCKET
, SO_SNDTIMEO
, @FSockTimeOut
, SizeOf(FSockTimeOut
));
273 function TTCPConnection
.ReadBuffer(PtrBuffer
: pointer; Len
: size_t
): ssize_t
;
275 Result
:= fpRecv(FSocket
, PtrBuffer
, Len
, 0);
278 function TTCPConnection
.WriteBuffer(PtrBuffer
: pointer; Len
: size_t
): ssize_t
;
280 Result
:= fpSend(FSocket
, PtrBuffer
, Len
, 0);
283 function TTCPConnection
.ReadLn(var Line
: string): boolean;
285 Result
:= SockReadLn(FSocket
, Line
);
288 function TTCPConnection
.WriteLn(const Line
: string): boolean;
290 Result
:= SockWriteLn(FSocket
, Line
);
294 function TTCPRFCConnection
.ReadCommand(var Command
: shortstring
; var Prms
: string): boolean;
296 Result
:= NetRFC
.ReadCommand(FSocket
, Command
, Prms
);
299 function TTCPRFCConnection
.ReadResponse(Response
: TRFCReply
): boolean;
301 Result
:= NetRFC
.ReadResponse(FSocket
, Response
);
304 function TTCPRFCConnection
.SendCommand(Command
: shortstring
): boolean;
306 Result
:= NetRFC
.SendCommand(FSocket
, Command
);
309 function TTCPRFCConnection
.SendCommand(Command
: shortstring
; Prms
: string): boolean;
311 Result
:= NetRFC
.SendCommand(FSocket
, Command
, Prms
);
314 function TTCPRFCConnection
.SendResponse(Response
: TRFCReply
): boolean;
316 Result
:= NetRFC
.SendResponse(FSocket
, Response
);
320 procedure TTCPAcceptor
.Execute
;
322 FHandler(FTCPConnection
);
326 function TTCPListener
.GetSockAddrStr
: string;
328 Result
:= NetAddrToStr(SockAddr
.sin_addr
) + ':' + IntToStr(ntohs(SockAddr
.sin_port
));
331 function TTCPListener
.StartListen
: boolean;
332 var GAIResult
: TGAIResult
;
334 FListenSocket
:= fpSocket(af_inet
, sock_stream
, 0);
335 if FListenSocket
<> -1 then begin
336 GAIResult
:= ResolveHost(FListenAddress
);
337 if GAIResult
.GAIError
= 0 then begin
338 SockAddr
:= GAIResult
.AddrInfo
^.ai_addr
^;
339 SockAddr
.sin_port
:= htons(FListenPort
);
341 if fpBind(FListenSocket
, @SockAddr
, SizeOf(SockAddr
)) <> -1 then begin
342 { It seems the maximum connection value isn't enforced by the
343 Free Pascal library, so this 512 is a constant, dummy value. }
344 if fpListen(FListenSocket
, 512) <> -1 then begin
359 procedure TTCPListener
.StopListen
;
365 procedure TTCPListener
.Execute
;
366 var ClientSocket
: socket
; AcceptFailCount
: word; Len
: longint;
367 TCPConnection
: TTCPConnection
;
369 { Now, accept connections. }
371 while not Terminated
do begin
372 Len
:= SizeOf(SockAddr
);
373 ClientSocket
:= fpAccept(FListenSocket
, @SockAddr
, @Len
);
374 if ClientSocket
<> -1 then begin
377 { Creates the requested TTCPConnection object for the accepted
379 case FFeatureRequest
of
381 TCPConnection
:= TTCPConnection
.Create(ClientSocket
);
383 TCPConnection
:= TTCPRFCConnection
.Create(ClientSocket
);
386 { Then start a new thread with the connection handler. }
387 TTCPAcceptor
.Create(HandleClient
, TCPConnection
);
390 Inc(AcceptFailCount
);
391 if AcceptFailCount
>= 512 then Terminate
;