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
, 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
; const Addr
: TSockAddr
); overload
;
58 destructor Destroy
; override;
66 function Connect(const HostName
: string; Port
: word): boolean;
68 procedure ReverseDNSLookup
;
69 function VerifyFCrDNS
: boolean;
70 procedure SetSockTimeOut(TimeOut
: DWord
);
71 function ReadBuffer(PtrBuffer
: pointer; Len
: size_t
): ssize_t
;
72 function WriteBuffer(PtrBuffer
: pointer; Len
: size_t
): ssize_t
;
73 function ReadLn(var Line
: string): boolean;
74 function WriteLn(const Line
: string): boolean;
75 property Connected
: boolean read FConnected
;
76 property Socket
: socket read FSocket
;
77 property HostIP
: TIPNamePair read FHostIP
;
78 property SockTimeOut
: DWord read FSockTimeOut write SetSockTimeOut
;
81 TTCPRFCConnection
= class(TTCPConnection
)
83 function ReadCommand(var Command
: shortstring
; var Prms
: string): boolean;
84 function ReadResponse(Response
: TRFCReply
): boolean;
85 function SendCommand(Command
: shortstring
): boolean; overload
;
86 function SendCommand(Command
: shortstring
; Prms
: string): boolean; overload
;
87 function SendResponse(Response
: TRFCReply
): boolean;
91 TTCPAcceptHandler
= procedure(Connection
: TTCPConnection
) of object;
93 TTCPAcceptor
= class(TThread
)
94 constructor Create(Handler
: TTCPAcceptHandler
; TCPConnection
: TTCPConnection
);
96 FHandler
: TTCPAcceptHandler
;
97 FTCPConnection
: TTCPConnection
;
98 procedure Execute
; override;
101 TTCPListener
= class(TThread
)
102 constructor Create(const Address
: string; Port
: word; FeatureRequest
: word);
103 {destructor Destroy; override;}
105 FFeatureRequest
: word;
106 FListenAddress
: string;
108 FListenSocket
: socket
;
111 procedure HandleClient(Connection
: TTCPConnection
); virtual; abstract;
112 procedure Execute
; override;
114 property ListenPort
: word read FListenPort
;
115 function StartListen
: boolean;
116 procedure StopListen
;
124 constructor TTCPConnection
.Create
;
125 { Create an instance, but don't connect to anywhere yet. }
130 FSockTimeOut
:= DEF_SOCK_TIMEOUT
;
133 constructor TTCPConnection
.Create(const HostName
: string; Port
: word);
134 { Connect to the given port on the given hostname. }
137 Connect(HostName
, Port
);
140 constructor TTCPConnection
.Create(Socket
: socket
; const Addr
: TSockAddr
);
141 { Use an already connected socket. }
146 FHostIP
:= TIPNamePair
.Create('', NetAddrToStr(Addr
.sin_addr
));
150 destructor TTCPConnection
.Destroy
;
152 if FConnected
then Disconnect
;
157 constructor TTCPAcceptor
.Create(Handler
: TTCPAcceptHandler
; TCPConnection
: TTCPConnection
);
158 { Start a connection handler on a distinct thread. }
161 FTCPConnection
:= TCPConnection
;
162 FreeOnTerminate
:= true;
163 inherited Create(false);
167 constructor TTCPListener
.Create(const Address
: string; Port
: word; FeatureRequest
: word);
169 FListenAddress
:= Address
;
171 FFeatureRequest
:= FeatureRequest
;
172 FreeOnTerminate
:= false;
173 FillChar(SockAddr
, SizeOf(SockAddr
), 0);
174 inherited Create(true);
178 function TTCPConnection
.Connect(const HostName
: string; Port
: word): boolean;
179 { Resolves the given hostname, and tries to connect it on the given port. }
180 var GAIResult
: TGAIResult
;
182 FSocket
:= fpSocket(af_inet
, sock_stream
, 0);
183 if (FSocket
<> -1) then begin
184 GAIResult
:= ResolveHost(HostName
);
185 if GAIResult
.GAIError
= 0 then begin
186 SockAddr
:= GAIResult
.AddrInfo
^.ai_addr
^;
187 SockAddr
.sin_port
:= htons(Port
);
189 if SockAddr
.sin_addr
.s_addr
<> 0 then
190 { Try to initiate connection. }
191 FConnected
:= fpConnect(FSocket
, @SockAddr
, SizeOf(SockAddr
)) <> -1;
193 if FConnected
then begin
194 FHostIP
:= TIPNamePair
.Create(HostName
, NetAddrToStr(SockAddr
.sin_addr
));
195 SetSockTimeOut(FSockTimeOut
);
198 CloseSocket(FSocket
);
206 procedure TTCPConnection
.Disconnect
;
208 fpShutdown(FSocket
, 2);
209 CloseSocket(FSocket
);
215 procedure TTCPConnection
.ReverseDNSLookup
;
216 { Performs a reverse DNS lookup, and updates the HostIP structure. }
217 var NHostIP
: TIPNamePair
;
219 if FConnected
then begin
220 NHostIP
:= TIPNamePair
.Create(ResolveIP(@SockAddr
), FHostIP
.IP
);
226 function TTCPConnection
.VerifyFCrDNS
: boolean;
227 var GAIResult
: TGAIResult
; ai
: PAddrInfo
;
230 GAIResult
:= ResolveHost(HostIP
.Name
);
231 if GAIResult
.GAIError
= 0 then begin
232 ai
:= GAIResult
.AddrInfo
;
233 { One of the addresses must match. }
234 while (ai
<> nil) and not Result
do begin
235 Result
:= NetAddrToStr(ai
^.ai_addr
^.sin_addr
) = HostIP
.IP
;
241 procedure TTCPConnection
.SetSockTimeOut(TimeOut
: DWord
);
243 FSockTimeOut
:= TimeOut
;
244 if Connected
then begin
245 fpSetSockOpt(FSocket
, SOL_SOCKET
, SO_RCVTIMEO
, @FSockTimeOut
, SizeOf(FSockTimeOut
));
246 fpSetSockOpt(FSocket
, SOL_SOCKET
, SO_SNDTIMEO
, @FSockTimeOut
, SizeOf(FSockTimeOut
));
250 function TTCPConnection
.ReadBuffer(PtrBuffer
: pointer; Len
: size_t
): ssize_t
;
252 Result
:= fpRecv(FSocket
, PtrBuffer
, Len
, 0);
255 function TTCPConnection
.WriteBuffer(PtrBuffer
: pointer; Len
: size_t
): ssize_t
;
257 Result
:= fpSend(FSocket
, PtrBuffer
, Len
, 0);
260 function TTCPConnection
.ReadLn(var Line
: string): boolean;
262 Result
:= SockReadLn(FSocket
, Line
);
265 function TTCPConnection
.WriteLn(const Line
: string): boolean;
267 Result
:= SockWriteLn(FSocket
, Line
);
271 function TTCPRFCConnection
.ReadCommand(var Command
: shortstring
; var Prms
: string): boolean;
273 Result
:= NetRFC
.ReadCommand(FSocket
, Command
, Prms
);
276 function TTCPRFCConnection
.ReadResponse(Response
: TRFCReply
): boolean;
278 Result
:= NetRFC
.ReadResponse(FSocket
, Response
);
281 function TTCPRFCConnection
.SendCommand(Command
: shortstring
): boolean;
283 Result
:= NetRFC
.SendCommand(FSocket
, Command
);
286 function TTCPRFCConnection
.SendCommand(Command
: shortstring
; Prms
: string): boolean;
288 Result
:= NetRFC
.SendCommand(FSocket
, Command
, Prms
);
291 function TTCPRFCConnection
.SendResponse(Response
: TRFCReply
): boolean;
293 Result
:= NetRFC
.SendResponse(FSocket
, Response
);
297 procedure TTCPAcceptor
.Execute
;
299 FHandler(FTCPConnection
);
303 function TTCPListener
.StartListen
: boolean;
304 var GAIResult
: TGAIResult
;
306 FListenSocket
:= fpSocket(af_inet
, sock_stream
, 0);
307 if FListenSocket
<> -1 then begin
308 GAIResult
:= ResolveHost(FListenAddress
);
309 if GAIResult
.GAIError
= 0 then begin
310 SockAddr
:= GAIResult
.AddrInfo
^.ai_addr
^;
311 SockAddr
.sin_port
:= htons(FListenPort
);
313 if fpBind(FListenSocket
, @SockAddr
, SizeOf(SockAddr
)) <> -1 then begin
314 { It seems the maximum connection value isn't enforced by the
315 Free Pascal library, so this 512 is a constant, dummy value. }
316 if fpListen(FListenSocket
, 512) <> -1 then begin
331 procedure TTCPListener
.StopListen
;
337 procedure TTCPListener
.Execute
;
338 var ClientSocket
: socket
; AcceptFailCount
: word; Len
: longint;
339 TCPConnection
: TTCPConnection
;
341 { Now, accept connections. }
343 while not Terminated
do begin
344 Len
:= SizeOf(SockAddr
);
345 ClientSocket
:= fpAccept(FListenSocket
, @SockAddr
, @Len
);
346 if ClientSocket
<> -1 then begin
349 { Creates the requested TTCPConnection object for the accepted
351 case FFeatureRequest
of
353 TCPConnection
:= TTCPConnection
.Create(ClientSocket
, SockAddr
);
355 TCPConnection
:= TTCPRFCConnection
.Create(ClientSocket
, SockAddr
);
358 { Then start a new thread with the connection handler. }
359 TTCPAcceptor
.Create(HandleClient
, TCPConnection
);
362 Inc(AcceptFailCount
);
363 if AcceptFailCount
>= 512 then Terminate
;