Class TBlockSocket

DescriptionHierarchyFieldsMethodsProperties

Unit

blcksock

Declaration

type TBlockSocket = class(TObject)

Description

Basic IP object.

This is parent class for other class with protocol implementations. Do not use this class directly! Use TICMPBlockSocket, TRAWBlockSocket, TTCPBlockSocket or TUDPBlockSocket instead.

Hierarchy

TBlockSocket > TObject

Methods

Overview

Public constructor Create;
Public constructor CreateAlternate(Stub: string);
Public destructor Destroy; override;
Published class function GetErrorDesc(ErrorCode: Integer): string;
Public procedure AbortSocket; virtual;
Public procedure Bind(IP, Port: string);
Public function CanRead(Timeout: Integer): Boolean; virtual;
Public function CanReadEx(Timeout: Integer): Boolean; virtual;
Public function CanWrite(Timeout: Integer): Boolean; virtual;
Public procedure CloseSocket; virtual;
Public procedure Connect(IP, Port: string); virtual;
Public procedure CreateSocket;
Public procedure CreateSocketByName(const Value: String);
Public procedure EnableReuse(Value: Boolean);
Public procedure ExceptCheck;
Public function GetLocalSinIP: string; virtual;
Public function GetLocalSinPort: Integer; virtual;
Public function GetRemoteSinIP: string; virtual;
Public function GetRemoteSinPort: Integer; virtual;
Public procedure GetSinLocal;
Public procedure GetSinRemote;
Public procedure GetSins;
Public function GetSocketProtocol: integer; Virtual;
Public function GetSocketType: integer; Virtual;
Public function GroupCanRead(const SocketList: TList; Timeout: Integer; const CanReadList: TList): Boolean;
Public function IP6ToStr(const value: TSockAddrIn6): string;
Public function LocalName: string;
Public function PeekBuffer(Buffer: TMemory; Length: Integer): Integer; virtual;
Public function PeekByte(Timeout: Integer): Byte; virtual;
Public procedure Purge;
Public function RecvBlock(Timeout: Integer): AnsiString; virtual;
Public function RecvBuffer(Buffer: TMemory; Length: Integer): Integer; virtual;
Public function RecvBufferEx(Buffer: Tmemory; Len: Integer; Timeout: Integer): Integer; virtual;
Public function RecvBufferFrom(Buffer: TMemory; Length: Integer): Integer; virtual;
Public function RecvBufferStr(Length: Integer; Timeout: Integer): AnsiString; virtual;
Public function RecvByte(Timeout: Integer): Byte; virtual;
Public function RecvInteger(Timeout: Integer): Integer; virtual;
Public function RecvPacket(Timeout: Integer): AnsiString; virtual;
Public procedure RecvStream(const Stream: TStream; Timeout: Integer); virtual;
Public procedure RecvStreamIndy(const Stream: TStream; Timeout: Integer); virtual;
Public procedure RecvStreamRaw(const Stream: TStream; Timeout: Integer); virtual;
Public procedure RecvStreamSize(const Stream: TStream; Timeout: Integer; Size: Integer);
Public function RecvString(Timeout: Integer): AnsiString; virtual;
Public function RecvTerminated(Timeout: Integer; const Terminator: AnsiString): AnsiString; virtual;
Public function ResolveIPToName(IP: string): string;
Public function ResolveName(Name: string): string;
Public procedure ResolveNameToIP(Name: string; const IPList: TStrings);
Public function ResolvePort(Port: string): Word;
Public procedure SendBlock(const Data: AnsiString); virtual;
Public function SendBuffer(Buffer: Tmemory; Length: Integer): Integer; virtual;
Public function SendBufferTo(Buffer: TMemory; Length: Integer): Integer; virtual;
Public procedure SendByte(Data: Byte); virtual;
Public procedure SendInteger(Data: integer); virtual;
Public procedure SendStream(const Stream: TStream); virtual;
Public procedure SendStreamIndy(const Stream: TStream); virtual;
Public procedure SendStreamRaw(const Stream: TStream); virtual;
Public procedure SendString(Data: AnsiString); virtual;
Public procedure SetLinger(Enable: Boolean; Linger: Integer);
Public procedure SetRecvTimeout(Timeout: Integer);
Public procedure SetRemoteSin(IP, Port: string);
Public procedure SetSendTimeout(Timeout: Integer);
Public procedure SetTimeout(Timeout: Integer);
Public function SockCheck(SockResult: Integer): Integer;
Public function StrToIP6(const value: string): TSockAddrIn6;
Public function WaitingData: Integer; virtual;
Public function WaitingDataEx: Integer;

Description

Public procedure AbortSocket; virtual;

Abort any work on Socket and destroy them.

Public procedure Bind(IP, Port: string);

Connects socket to local IP address and PORT. IP address may be numeric or symbolic ('192.168.74.50', 'cosi.nekde.cz', 'ff08::1'). The same for PORT - it may be number or mnemonic port ('23', 'telnet').

If port value is '0', system chooses itself and conects unused port in the range 1024 to 4096 (this depending by operating system!). Structure LocalSin is filled after calling this method.

Note: If you call this on non-created socket, then socket is created automaticly.

Warning: when you call : Bind('0.0.0.0','0'); then is nothing done! In this case is used implicit system bind instead.

Public function CanRead(Timeout: Integer): Boolean; virtual;

Return True, if you can read any data from socket or is incoming connection on TCP based socket. Status is tested for time Timeout (in milliseconds). If value in Timeout is 0, status is only tested and continue. If value in Timeout is -1, run is breaked and waiting for read data maybe forever.

This function is need only on special cases, when you need use RecvBuffer function directly!

Public function CanReadEx(Timeout: Integer): Boolean; virtual;

Same as CanRead, but additionally return True if is some data in LineBuffer.

Public function CanWrite(Timeout: Integer): Boolean; virtual;

Return True, if you can to socket write any data (not full sending buffer). Status is tested for time Timeout (in milliseconds). If value in Timeout is 0, status is only tested and continue. If value in Timeout is -1, run is breaked and waiting for write data maybe forever.

This function is need only on special cases!

Public procedure CloseSocket; virtual;

Destroy socket in use. This method is also automatically called from object destructor.

Public procedure Connect(IP, Port: string); virtual;

Connects socket to remote IP address and PORT. The same rules as with Bind method are valid. The only exception is that PORT with 0 value will not be connected!

Structures LocalSin and RemoteSin will be filled with valid values.

When you call this on non-created socket, then socket is created automaticly. Type of created socket is by Family property. If is used SF_IP4, then is created socket for IPv4. If is used SF_IP6, then is created socket for IPv6. When you have family on SF_Any (default!), then type of created socket is determined by address resolving of destination address. (Not work properly on prilimitary winsock IPv6 support!)

Public constructor Create;

 

Public constructor CreateAlternate(Stub: string);

Create object and load all necessary socket library. What library is loaded is described by STUB parameter. If STUB is empty string, then is loaded default libraries.

Public procedure CreateSocket;

If Family is not SF_Any, then create socket with type defined in Family property. If family is SF_Any, then do nothing! (socket is created automaticly when you know what type of socket you need to create. (i.e. inside Connect or Bind call.) When socket is created, then is aplyed all stored delayed socket options.

Public procedure CreateSocketByName(const Value: String);

It create socket. Address resolving of Value tells what type of socket is created. If Value is resolved as IPv4 IP, then is created IPv4 socket. If value is resolved as IPv6 address, then is created IPv6 socket.

Public destructor Destroy; override;

 

Public procedure EnableReuse(Value: Boolean);

By this method you may turn address reuse mode for local Bind. It is good specially for UDP protocol. Using this with TCP protocol is hazardous!

Public procedure ExceptCheck;

If LastError contains some error code and RaiseExcept property is True, raise adequate exception.

Published class function GetErrorDesc(ErrorCode: Integer): string;

Return descriptive string for given error code. This is class function. You may call it without created object!

Public function GetLocalSinIP: string; virtual;

Picks IP socket address from LocalSin.

Public function GetLocalSinPort: Integer; virtual;

Picks socket PORT number from LocalSin.

Public function GetRemoteSinIP: string; virtual;

Picks IP socket address from RemoteSin.

Public function GetRemoteSinPort: Integer; virtual;

Picks socket PORT number from RemoteSin.

Public procedure GetSinLocal;

Actualize values in LocalSin.

Public procedure GetSinRemote;

Actualize values in RemoteSin.

Public procedure GetSins;

Actualize values in LocalSin and RemoteSin.

Public function GetSocketProtocol: integer; Virtual;

Return value of protocol type for socket creation.

Public function GetSocketType: integer; Virtual;

Return value of socket type.

Public function GroupCanRead(const SocketList: TList; Timeout: Integer; const CanReadList: TList): Boolean;

This function is for check for incoming data on set of sockets. Whitch sockets is checked is decribed by SocketList Tlist with TBlockSocket objects. TList may have maximal number of objects defined by FD_SETSIZE constant. Return True, if you can from some socket read any data or is incoming connection on TCP based socket. Status is tested for time Timeout (in milliseconds). If value in Timeout is 0, status is only tested and continue. If value in Timeout is -1, run is breaked and waiting for read data maybe forever. If is returned True, CanReadList TList is filled by all TBlockSocket objects what waiting for read.

Public function IP6ToStr(const value: TSockAddrIn6): string;

Convert IPv6 address from binary to string form. This function working only on systems with IPv6 support!

Public function LocalName: string;

Returns local computer name as numerical or symbolic value. It try get fully qualified domain name. Name is returned in the format acceptable by functions demanding IP as input parameter.

Public function PeekBuffer(Buffer: TMemory; Length: Integer): Integer; virtual;

Same as RecvBuffer, but readed data stays in system input buffer. Warning: this function not respect data in LineBuffer! Is not recommended to use this function!

Public function PeekByte(Timeout: Integer): Byte; virtual;

Same as RecvByte, but readed data stays in input system buffer. Warning: this function not respect data in LineBuffer! Is not recommended to use this function!

Public procedure Purge;

Clear all waiting data for read from buffers.

Public function RecvBlock(Timeout: Integer): AnsiString; virtual;

Read one block of data from socket. Each block begin with 4 bytes with length of data in block. This function read first 4 bytes for get lenght, then it wait for reported count of bytes.

Public function RecvBuffer(Buffer: TMemory; Length: Integer): Integer; virtual;

Note: This is low-level receive function. You must be sure if data is waiting for read before call this function for avoid deadlock!

Waits until allocated buffer is filled by received data. Returns number of data received, which equals to LENGTH value under normal operation. If it is not equal the communication channel is possibly broken.

On stream oriented sockets if is received 0 bytes, it mean 'socket is closed!"

On datagram socket is readed first waiting datagram.

Public function RecvBufferEx(Buffer: Tmemory; Len: Integer; Timeout: Integer): Integer; virtual;

Note: This is high-level receive function. It using internal LineBuffer and you can combine this function freely with other high-level functions!

Method waits until data is received. If no data is received within TIMEOUT (in milliseconds) period, LastError is set to WSAETIMEDOUT. Methods serves for reading any size of data (i.e. one megabyte...). This method is preffered for reading from stream sockets (like TCP).

Public function RecvBufferFrom(Buffer: TMemory; Length: Integer): Integer; virtual;

Note: This is low-lever receive function. You must be sure if data is waiting for read before call this function for avoid deadlock!

Receives first waiting datagram to allocated buffer. If there is no waiting one, then waits until one comes. Returns length of datagram stored in BUFFER. If length exceeds buffer datagram is truncated. After this RemoteSin structure contains information about sender of UDP packet.

Public function RecvBufferStr(Length: Integer; Timeout: Integer): AnsiString; virtual;

Similar to RecvBufferEx, but readed data is stored in binary string, not in memory buffer.

Public function RecvByte(Timeout: Integer): Byte; virtual;

Note: This is high-level receive function. It using internal LineBuffer and you can combine this function freely with other high-level functions.

Waits until one data byte is received which is also returned as function result. If no data is received within TIMEOUT (in milliseconds)period, LastError is set to WSAETIMEDOUT and result have value 0.

Public function RecvInteger(Timeout: Integer): Integer; virtual;

Note: This is high-level receive function. It using internal LineBuffer and you can combine this function freely with other high-level functions.

Waits until one four bytes are received and return it as one Ineger Value. If no data is received within TIMEOUT (in milliseconds)period, LastError is set to WSAETIMEDOUT and result have value 0.

Public function RecvPacket(Timeout: Integer): AnsiString; virtual;

Note: This is high-level receive function. It using internal LineBuffer and you can combine this function freely with other high-level functions.

Method reads all data waiting for read. If no data is received within TIMEOUT (in milliseconds) period, LastError is set to WSAETIMEDOUT. Methods serves for reading unknown size of data. Because before call this function you don't know size of received data, returned data is stored in dynamic size binary string. This method is preffered for reading from stream sockets (like TCP). It is very goot for receiving datagrams too! (UDP protocol)

Public procedure RecvStream(const Stream: TStream; Timeout: Integer); virtual;

Receive data to stream. It using RecvBlock method.

Public procedure RecvStreamIndy(const Stream: TStream; Timeout: Integer); virtual;

Receive data to stream. This function is compatible with similar function in Indy library. It using RecvBlock method.

Public procedure RecvStreamRaw(const Stream: TStream; Timeout: Integer); virtual;

Read all data from socket to stream until socket is closed (or any error occured.)

Public procedure RecvStreamSize(const Stream: TStream; Timeout: Integer; Size: Integer);

Read requested count of bytes from socket to stream.

Public function RecvString(Timeout: Integer): AnsiString; virtual;

Note: This is high-level receive function. It using internal LineBuffer and you can combine this function freely with other high-level functions.

Method waits until data string is received. This string is terminated by CR-LF characters. The resulting string is returned without this termination (CR-LF)! If ConvertLineEnd is used, then CR-LF sequence may not be exactly CR-LF. See ConvertLineEnd description. If no data is received within TIMEOUT (in milliseconds) period, LastError is set to WSAETIMEDOUT. You may also specify maximum length of reading data by MaxLineLength property.

Public function RecvTerminated(Timeout: Integer; const Terminator: AnsiString): AnsiString; virtual;

Note: This is high-level receive function. It using internal LineBuffer and you can combine this function freely with other high-level functions.

Method waits until data string is received. This string is terminated by Terminator string. The resulting string is returned without this termination. If no data is received within TIMEOUT (in milliseconds) period, LastError is set to WSAETIMEDOUT. You may also specify maximum length of reading data by MaxLineLength property.

Public function ResolveIPToName(IP: string): string;

Try resolve IP to their primary domain name. If IP not have domain name, then is returned original IP.

Public function ResolveName(Name: string): string;

Try resolve name to primary IP address. i.e. If you pass as name result of LocalName method, you get primary IP addresses used by local system.

Public procedure ResolveNameToIP(Name: string; const IPList: TStrings);

Try resolve name to all possible IP address. i.e. If you pass as name result of LocalName method, you get all IP addresses used by local system.

Public function ResolvePort(Port: string): Word;

Try resolve symbolic port name to port number. (i.e. 'Echo' to 8)

Public procedure SendBlock(const Data: AnsiString); virtual;

Send data as one block to socket. Each block begin with 4 bytes with length of data in block. This 4 bytes is added automaticly by this function.

Public function SendBuffer(Buffer: Tmemory; Length: Integer): Integer; virtual;

Sends data of LENGTH from BUFFER address via connected socket. System automatically splits data to packets.

Public function SendBufferTo(Buffer: TMemory; Length: Integer): Integer; virtual;

Same as SendBuffer, but send datagram to address from RemoteSin. Usefull for sending reply to datagram received by function RecvBufferFrom.

Public procedure SendByte(Data: Byte); virtual;

One data BYTE is sent via connected socket.

Public procedure SendInteger(Data: integer); virtual;

Send integer as four bytes to socket.

Public procedure SendStream(const Stream: TStream); virtual;

Send content of stream to socket. It using SendBlock method

Public procedure SendStreamIndy(const Stream: TStream); virtual;

Send content of stream to socket. It using SendBlock method and this is compatible with streams in Indy library.

Public procedure SendStreamRaw(const Stream: TStream); virtual;

Send data from stream to socket.

Public procedure SendString(Data: AnsiString); virtual;

Send data string via connected socket. Any terminator is not added! If you need send true string with CR-LF termination, you must add CR-LF characters to sended string! Because any termination is not added automaticly, you can use this function for sending any binary data in binary string.

Public procedure SetLinger(Enable: Boolean; Linger: Integer);

Sets linger. Enabled linger means that the system waits another LINGER (in milliseconds) time for delivery of sent data. This function is only for stream type of socket! (TCP)

Public procedure SetRecvTimeout(Timeout: Integer);

Try set timeout for all receiving operations, if socket provider can do it. (It not supported by all socket providers!)

Public procedure SetRemoteSin(IP, Port: string);

Set information about remote side socket. It is good for seting remote side for sending UDP packet, etc.

Public procedure SetSendTimeout(Timeout: Integer);

Try set timeout for all sending operations, if socket provider can do it. (It not supported by all socket providers!)

Public procedure SetTimeout(Timeout: Integer);

Try set timeout for all sending and receiving operations, if socket provider can do it. (It not supported by all socket providers!)

Public function SockCheck(SockResult: Integer): Integer;

If you "manually" call Socket API functions, forward their return code as parameter to this function, which evaluates it, eventually calls GetLastError and found error code returns and stores to LastError.

Public function StrToIP6(const value: string): TSockAddrIn6;

Convert IPv6 address from their string form to binary. This function working only on systems with IPv6 support!

Public function WaitingData: Integer; virtual;

On stream sockets it returns number of received bytes waiting for picking. 0 is returned when there is no such data. On datagram socket it returns length of the first waiting datagram. Returns 0 if no datagram is waiting.

Public function WaitingDataEx: Integer;

Same as WaitingData, but if exists some of data in LineBuffer, return their length instead.

Properties

Overview

Published property ConvertLineEnd: Boolean;
Published property Family: TSocketFamily;
Published property InterPacketTimeout: Boolean;
Public property IP6used: Boolean;
Public property LastError: Integer;
Public property LastErrorDesc: string;
Public property LineBuffer: string;
Public property LocalSin: TVarSin;
Published property MaxBandwidth: Integer;
Published property MaxLineLength: Integer;
Published property MaxRecvBandwidth: Integer;
Published property MaxSendBandwidth: Integer;
Public property NonBlockMode: Boolean;
Published property OnCreateSocket: THookCreateSocket;
Published property OnReadFilter: THookDataFilter;
Published property OnStatus: THookSocketStatus;
Published property OnWriteFilter: THookDataFilter;
Published property PreferIP4: Boolean;
Published property RaiseExcept: Boolean;
Public property RecvCounter: Integer;
Public property RemoteSin: TVarSin;
Public property SendCounter: Integer;
Published property SendMaxChunk: Integer;
Public property SizeRecvBuffer: Integer;
Public property SizeSendBuffer: Integer;
Public property Socket: TSocket;
Published property StopFlag: Boolean;
Published property Tag: Integer;
Public property TTL: Integer;
Public property WSAData: TWSADATA;

Description

Published property ConvertLineEnd: Boolean;

Do a conversion of non-standard line terminators to CRLF. (Off by default) If True, then terminators like sigle CR, single LF or LFCR are converted to CRLF internally. This have effect only in RecvString method!

Published property Family: TSocketFamily;

Specified Family of this socket. When you are using Windows preliminary support for IPv6, then I recommend to set this property!

Published property InterPacketTimeout: Boolean;

By dafault (False) is all timeouts used as timeout between two packets in reading operations. If you set this to True, then Timeouts is for overall reading operation!

Public property IP6used: Boolean;

If is True, then class in in IPv6 mode.

Public property LastError: Integer;

Last socket operation error code. Error codes are described in socket documentation. Human readable error description is stored in LastErrorDesc property.

Public property LastErrorDesc: string;

Human readable error description of LastError code.

Public property LineBuffer: string;

Buffer used by all high-level receiving functions. This buffer is used for optimized reading of data from socket. In normal cases you not need access to this buffer directly!

Public property LocalSin: TVarSin;

Structure describing local socket side.

Published property MaxBandwidth: Integer;

Define maximal bandwidth for all sending and receiving operations in bytes per second. If value is 0 (default), bandwidth limitation is not used.

Published property MaxLineLength: Integer;

Define maximum length in bytes of LineBuffer for high-level receiving functions. If this functions try to read more data then this limit, error is returned! If value is 0 (default), no limitation is used. This is very good protection for stupid attacks to your server by sending lot of data without proper terminator... until all your memory is allocated by LineBuffer!

Note: This maximum length is checked only in functions, what read unknown number of bytes! (like RecvString or RecvTerminated)

Published property MaxRecvBandwidth: Integer;

Define maximal bandwidth for all receiving operations in bytes per second. If value is 0 (default), bandwidth limitation is not used.

Published property MaxSendBandwidth: Integer;

Define maximal bandwidth for all sending operations in bytes per second. If value is 0 (default), bandwidth limitation is not used.

Public property NonBlockMode: Boolean;

If True, turn class to non-blocking mode. Not all functions are working properly in this mode, you must know exactly what you are doing! However when you have big experience with non-blocking programming, then you can optimise your program by non-block mode!

Published property OnCreateSocket: THookCreateSocket;

This event is called after real socket creation for setting special socket options, because you not know when socket is created. (it is depended on Ipv4, IPv6 or automatic mode)

Published property OnReadFilter: THookDataFilter;

this event is good for some internal thinks about filtering readed datas. It is used by telnet client by example.

Published property OnStatus: THookSocketStatus;

This event is called by various reasons. It is good for monitoring socket, create gauges for data transfers, etc.

Published property OnWriteFilter: THookDataFilter;

This event is good for some internal thinks about filtering writed datas.

Published property PreferIP4: Boolean;

When resolving of domain name return both IPv4 and IPv6 addresses, then specify if is used IPv4 (dafault - True) or IPv6.

Published property RaiseExcept: Boolean;

If True, winsock errors raises exception. Otherwise is setted LastError value only and you must check it from your program! Default value is False.

Public property RecvCounter: Integer;

Return count of received bytes on this socket from begin of current connection.

Public property RemoteSin: TVarSin;

Structure describing remote socket side.

Public property SendCounter: Integer;

Return count of sended bytes on this socket from begin of current connection.

Published property SendMaxChunk: Integer;

All sended datas was splitted by this value.

Public property SizeRecvBuffer: Integer;

Size of Winsock receive buffer. If it is not supported by socket provider, it return as size one kilobyte.

Public property SizeSendBuffer: Integer;

Size of Winsock send buffer. If it is not supported by socket provider, it return as size one kilobyte.

Public property Socket: TSocket;

Socket handler. Suitable for "manual" calls to socket API or manual connection of socket to a previously created socket (i.e by Accept method on TCP socket)

Published property StopFlag: Boolean;

By setting this property to True you can stop any communication. You can use this property for soft abort of communication.

Published property Tag: Integer;

this value is for free use.

Public property TTL: Integer;

Set Time-to-live value. (if system supporting it!)

Public property WSAData: TWSADATA;

WSA structure with information about socket provider. On linux is this structure simulated!


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