ICMPPort Class

Properties   Methods   Events   Configuration Settings   Errors  

The ICMPPort class is used to facilitate ICMP communications. It can act both as a client and a server and communicate with any number of hosts simultaneously, as well as generate and receive broadcast packets.

Syntax

ICMPPort

Remarks

The interface of the class is similar to the interface of IPPort, only much simpler. The class is activated/deactivated by using the Active property. This property enables or disables sends or receives. Data can be sent in the same way as IPPort, using the Send method and Text parameter or the DataToSend property. The destination is specified using the RemoteHost property. The class automatically creates an ICMP header containing MessageType, MessageSubType, and a checksum for the message.

If the UseConnection config setting is set to True, then a local association is created with the remote host. Otherwise, the class can receive datagrams (packets) from any host, and send datagrams to any host. Packets can be broadcast on the local net by setting the destination to 255.255.255.255.

Inbound data is received through the DataIn event.

The operation of the class is almost completely asynchronous. All the calls, except the ones that deal with domain name resolution, operate through Windows messages (no blocking calls). The gain in performance is considerable when compared to using blocking calls.

Property List

The following is the full list of the properties of the class with short descriptions. Click on the links for further details.

Method List

The following is the full list of the methods of the class with short descriptions. Click on the links for further details.

Event List

The following is the full list of the events fired by the class with short descriptions. Click on the links for further details.

Configuration Settings

The following is a list of configuration settings for the class with short descriptions. Click on the links for further details.

AcceptData Property (ICMPPort Class)

Enables or disables data reception (the DataIn event).

Syntax

• C++
• Objective-C
• C

ANSI (Cross Platform)
int GetAcceptData();
int SetAcceptData(int bAcceptData);

Unicode (Windows)
BOOL GetAcceptData();
INT SetAcceptData(BOOL bAcceptData);

@property (nonatomic,readwrite,assign,getter=acceptData,setter=setAcceptData:) BOOL acceptData;

- (BOOL)acceptData;
- (void)setAcceptData:(BOOL)newAcceptData;

int ipworks_icmpport_getacceptdata(void* lpObj);
int ipworks_icmpport_setacceptdata(void* lpObj, int bAcceptData);

Default Value

TRUE

Remarks

This property enables or disables data reception (the DataIn event). Setting this property to False, temporarily disables data reception (and the DataIn event). Setting this property to True, re-enables data reception.

Note: It is recommended to use the PauseData or ProcessData method instead of setting this property.

This property is not available at design time.

Data Type

Boolean

Active Property (ICMPPort Class)

Enables or disables sending and receiving of data.

Syntax

• C++
• Objective-C
• C

ANSI (Cross Platform)
int GetActive();
int SetActive(int bActive);

Unicode (Windows)
BOOL GetActive();
INT SetActive(BOOL bActive);

@property (nonatomic,readwrite,assign,getter=active,setter=setActive:) BOOL active;

- (BOOL)active;
- (void)setActive:(BOOL)newActive;

int ipworks_icmpport_getactive(void* lpObj);
int ipworks_icmpport_setactive(void* lpObj, int bActive);

Default Value

FALSE

Remarks

Setting this property to True makes the class create a communication endpoint (socket) which can be used for sending and receiving ICMP messages. Setting it to False destroys the socket and disables data communications.

If the UseConnection config setting is set to True, then a local association (connection) to the remote host is also created.

Note: It is recommended to use the Activate or Deactivate method instead of setting this property.

This property is not available at design time.

Data Type

Boolean

DontRoute Property (ICMPPort Class)

If set to True, it forces the socket to send data directly to interface (no routing).

Syntax

• C++
• Objective-C
• C

ANSI (Cross Platform)
int GetDontRoute();
int SetDontRoute(int bDontRoute);

Unicode (Windows)
BOOL GetDontRoute();
INT SetDontRoute(BOOL bDontRoute);

@property (nonatomic,readwrite,assign,getter=dontRoute,setter=setDontRoute:) BOOL dontRoute;

- (BOOL)dontRoute;
- (void)setDontRoute:(BOOL)newDontRoute;

int ipworks_icmpport_getdontroute(void* lpObj);
int ipworks_icmpport_setdontroute(void* lpObj, int bDontRoute);

Default Value

FALSE

Remarks

If this property is set to True, it forces the socket to send data directly to interface (no routing). Normally IP sockets send packets of data through routers and gateways until they reach the final destination. If this property is set to True, then data will be delivered on the local subnet only.

This property is not available at design time.

Data Type

Boolean

LocalHost Property (ICMPPort Class)

The name of the local host or user-assigned IP interface through which connections are initiated or accepted.

Syntax

• C++
• Objective-C
• C

ANSI (Cross Platform)
char* GetLocalHost();
int SetLocalHost(const char* lpszLocalHost);

Unicode (Windows)
LPWSTR GetLocalHost();
INT SetLocalHost(LPCWSTR lpszLocalHost);

@property (nonatomic,readwrite,assign,getter=localHost,setter=setLocalHost:) NSString* localHost;

- (NSString*)localHost;
- (void)setLocalHost:(NSString*)newLocalHost;

char* ipworks_icmpport_getlocalhost(void* lpObj);
int ipworks_icmpport_setlocalhost(void* lpObj, const char* lpszLocalHost);

Default Value

""

Remarks

The LocalHost property contains the name of the local host as obtained by the gethostname() system call, or if the user has assigned an IP address, the value of that address.

In multi-homed hosts (machines with more than one IP interface) setting LocalHost to the value of an interface will make the class initiate connections (or accept in the case of server classs) only through that interface.

If the class is connected, the LocalHost property shows the IP address of the interface through which the connection is made in internet dotted format (aaa.bbb.ccc.ddd). In most cases, this is the address of the local host, except for multi-homed hosts (machines with more than one IP interface).

NOTE: LocalHost is not persistent. You must always set it in code, and never in the property window.

Data Type

String

MessageSubType Property (ICMPPort Class)

The subtype of the ICMP message (part of the ICMP header).

Syntax

• C++
• Objective-C
• C

ANSI (Cross Platform)
int GetMessageSubType();
int SetMessageSubType(int iMessageSubType);

Unicode (Windows)
INT GetMessageSubType();
INT SetMessageSubType(INT iMessageSubType);

@property (nonatomic,readwrite,assign,getter=messageSubType,setter=setMessageSubType:) int messageSubType;

- (int)messageSubType;
- (void)setMessageSubType:(int)newMessageSubType;

int ipworks_icmpport_getmessagesubtype(void* lpObj);
int ipworks_icmpport_setmessagesubtype(void* lpObj, int iMessageSubType);

Default Value

0

Remarks

This property contains the subtype of the ICMP message (part of the ICMP header). The ICMP message subtype (also referred to as 'code') is a byte value representing the message subclass. Its meaning is associated with the MessageType.

Types and subtypes for ICMP messages are defined in the various internet RFCs and other documentation associated with TCP/IP.

Data Type

Integer

MessageType Property (ICMPPort Class)

The type of the ICMP message (part of the ICMP header).

Syntax

• C++
• Objective-C
• C

ANSI (Cross Platform)
int GetMessageType();
int SetMessageType(int iMessageType);

Unicode (Windows)
INT GetMessageType();
INT SetMessageType(INT iMessageType);

@property (nonatomic,readwrite,assign,getter=messageType,setter=setMessageType:) int messageType;

- (int)messageType;
- (void)setMessageType:(int)newMessageType;

int ipworks_icmpport_getmessagetype(void* lpObj);
int ipworks_icmpport_setmessagetype(void* lpObj, int iMessageType);

Default Value

0

Remarks

This property contains the type of the ICMP message (part of the ICMP header). The ICMP message type is a byte value representing the message class. The message type defines the structure and meaning of the message data assigned to DataToSend.

Types for ICMP messages are defined in the various internet RFCs and other documentation associated with TCP/IP. The following are a few examples of ICMP message types:

Data Type

Integer

RemoteHost Property (ICMPPort Class)

The address of the RemoteHost. Domain names are resolved to IP addresses.

Syntax

• C++
• Objective-C
• C

ANSI (Cross Platform)
char* GetRemoteHost();
int SetRemoteHost(const char* lpszRemoteHost);

Unicode (Windows)
LPWSTR GetRemoteHost();
INT SetRemoteHost(LPCWSTR lpszRemoteHost);

@property (nonatomic,readwrite,assign,getter=remoteHost,setter=setRemoteHost:) NSString* remoteHost;

- (NSString*)remoteHost;
- (void)setRemoteHost:(NSString*)newRemoteHost;

char* ipworks_icmpport_getremotehost(void* lpObj);
int ipworks_icmpport_setremotehost(void* lpObj, const char* lpszRemoteHost);

Default Value

""

Remarks

This property specifies the IP address (IP number in dotted internet format) or Domain Name of the remote host.

If this property is set to 255.255.255.255, the class broadcasts data on the local subnet.

If this property is set to a Domain Name, a DNS request is initiated and upon successful termination of the request, the property is set to the corresponding address. If the search is not successful, the class fails with an error.

If UseConnection is True, this property must be set before the class is activated (Active is set to True).

Data Type

String

Timeout Property (ICMPPort Class)

A timeout for the class.

Syntax

• C++
• Objective-C
• C

ANSI (Cross Platform)
int GetTimeout();
int SetTimeout(int iTimeout);

Unicode (Windows)
INT GetTimeout();
INT SetTimeout(INT iTimeout);

@property (nonatomic,readwrite,assign,getter=timeout,setter=setTimeout:) int timeout;

- (int)timeout;
- (void)setTimeout:(int)newTimeout;

int ipworks_icmpport_gettimeout(void* lpObj);
int ipworks_icmpport_settimeout(void* lpObj, int iTimeout);

Default Value

0

Remarks

If the Timeout property is set to 0, all operations return immediately, potentially failing with an 'WOULDBLOCK' error if data can't be sent or received immediately.

If Timeout is set to a positive value, the class will automatically retry each operation that would otherwise result in a 'WOULDBLOCK' error for a maximum of Timeout seconds.

The class will use DoEvents to enter an efficient wait loop during any potential waiting period, making sure that all system events are processed immediately as they arrive. This ensures that the host application does not "freeze" and remains responsive.

If Timeout expires, and the operation is not yet complete, the class fails with an error.

Please note that by default, all timeouts are inactivity timeouts, i.e. the timeout period is extended by Timeout seconds when any amount of data is successfully sent or received.

The default value for the Timeout property is 0 (asynchronous operation).

Data Type

Integer

TimeToLive Property (ICMPPort Class)

The time to live (TTL) value for the ICMP packets sent by the class.

Syntax

• C++
• Objective-C
• C

ANSI (Cross Platform)
int GetTimeToLive();
int SetTimeToLive(int iTimeToLive);

Unicode (Windows)
INT GetTimeToLive();
INT SetTimeToLive(INT iTimeToLive);

@property (nonatomic,readwrite,assign,getter=timeToLive,setter=setTimeToLive:) int timeToLive;

- (int)timeToLive;
- (void)setTimeToLive:(int)newTimeToLive;

int ipworks_icmpport_gettimetolive(void* lpObj);
int ipworks_icmpport_settimetolive(void* lpObj, int iTimeToLive);

Default Value

0

Remarks

This method contains the Time-To-Live (TTL) value for the ICMP packets sent by the class. The Time-to-Live (TTL) field of the ICMP packet is a counter limiting the lifetime of a packet.

Each router (or other module) that handles a packet decrements the TTL field by one or more if it holds the packet for more than one second, thus the TTL is effectively a hop count limit on how far a datagram can propagate through the Internet. When the TTL is reduced to zero (or less), the packet is discarded.

If the value of the property is set to 0, then the default TTL value of the underlying TCP/IP subsystem will be used.

This property is not available at design time.

Data Type

Integer

Activate Method (ICMPPort Class)

Enables sending and receiving of data.

Syntax

• C++
• Objective-C
• C

ANSI (Cross Platform)
int Activate();

Unicode (Windows)
INT Activate();

- (void)activate;

int ipworks_icmpport_activate(void* lpObj);

Remarks

This method enables sending and receiving of data. When called the class will create a communication endpoint (socket) which can be used for sending and receiving ICMP messages. This method must be called before using the class to send and receive data.

If the UseConnection configuration setting is set to true, then a local association (connection) to the remote host is also created.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

Config Method (ICMPPort Class)

Sets or retrieves a configuration setting.

Syntax

• C++
• Objective-C
• C

ANSI (Cross Platform)
char* Config(const char* lpszConfigurationString);

Unicode (Windows)
LPWSTR Config(LPCWSTR lpszConfigurationString);

- (NSString*)config:(NSString*)configurationString;

char* ipworks_icmpport_config(void* lpObj, const char* lpszConfigurationString);

Remarks

Config is a generic method available in every class. It is used to set and retrieve configuration settings for the class.

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the class, access to these internal properties is provided through the Config method.

To set a configuration setting named PROPERTY, you must call Config("PROPERTY=VALUE"), where VALUE is the value of the setting expressed as a string. For boolean values, use the strings "True", "False", "0", "1", "Yes", or "No" (case does not matter).

To read (query) the value of a configuration setting, you must call Config("PROPERTY"). The value will be returned as a string.

Error Handling (C++)

This method returns a String value; after it returns, call the GetLastErrorCode() method to obtain its result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message.

Deactivate Method (ICMPPort Class)

Disables sending and receive of data.

Syntax

• C++
• Objective-C
• C

ANSI (Cross Platform)
int Deactivate();

Unicode (Windows)
INT Deactivate();

- (void)deactivate;

int ipworks_icmpport_deactivate(void* lpObj);

Remarks

This method disables sending and receiving of data. When called the class will destroy the existing socket and disable data communications.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

DoEvents Method (ICMPPort Class)

Processes events from the internal message queue.

Syntax

• C++
• Objective-C
• C

ANSI (Cross Platform)
int DoEvents();

Unicode (Windows)
INT DoEvents();

- (void)doEvents;

int ipworks_icmpport_doevents(void* lpObj);

Remarks

When DoEvents is called, the class processes any available events. If no events are available, it waits for a preset period of time, and then returns.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

PauseData Method (ICMPPort Class)

Pauses data reception.

Syntax

• C++
• Objective-C
• C

ANSI (Cross Platform)
int PauseData();

Unicode (Windows)
INT PauseData();

- (void)pauseData;

int ipworks_icmpport_pausedata(void* lpObj);

Remarks

This method pauses data reception when called. While data reception is paused the DataIn event will not fire. Call ProcessData to re-enable data reception.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

ProcessData Method (ICMPPort Class)

Re-enables data reception after a call to PauseData .

Syntax

• C++
• Objective-C
• C

ANSI (Cross Platform)
int ProcessData();

Unicode (Windows)
INT ProcessData();

- (void)processData;

int ipworks_icmpport_processdata(void* lpObj);

Remarks

This method re-enables data reception after a previous call to PauseData. When PauseData is called the DataIn event will not fire. To re-enable data reception and allow DataIn to fire call this method.

Note: This method is only used after previously calling PauseData. It does not need to be called to process incoming data by default.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

Reset Method (ICMPPort Class)

Reset the class.

Syntax

• C++
• Objective-C
• C

ANSI (Cross Platform)
int Reset();

Unicode (Windows)
INT Reset();

- (void)reset;

int ipworks_icmpport_reset(void* lpObj);

Remarks

This method will reset the class's properties to their default values.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

ResolveRemoteHost Method (ICMPPort Class)

Resolves the hostname in RemoteHost to an IP address.

Syntax

• C++
• Objective-C
• C

ANSI (Cross Platform)
int ResolveRemoteHost();

Unicode (Windows)
INT ResolveRemoteHost();

- (void)resolveRemoteHost;

int ipworks_icmpport_resolveremotehost(void* lpObj);

Remarks

This method resolves the hostname specified by RemoteHost to an IP address. The resolved value is available in the RemoteHost property after this method returns.

In most cases calling this method is not necessary, the class will resolve the hostname automatically when necessary. If DelayHostResolution is true this method may be called to manually resolve RemoteHost if desired.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

Send Method (ICMPPort Class)

Sends data to the remote host.

Syntax

• C++
• Objective-C
• C

ANSI (Cross Platform)
int Send(const char* lpText, int lenText);

Unicode (Windows)
INT Send(LPCSTR lpText, INT lenText);

- (void)send:(NSData*)text;

int ipworks_icmpport_send(void* lpObj, const char* lpText, int lenText);

Remarks

This method sends data to the remote host. Calling this method is equivalent to setting the DataToSend property to Text.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

SendBytes Method (ICMPPort Class)

Sends data to the remote host.

Syntax

• C++
• Objective-C
• C

ANSI (Cross Platform)
int SendBytes(const char* lpData, int lenData);

Unicode (Windows)
INT SendBytes(LPCSTR lpData, INT lenData);

- (void)sendBytes:(NSData*)data;

int ipworks_icmpport_sendbytes(void* lpObj, const char* lpData, int lenData);

Remarks

This method sends data to the remote host. Calling this method is equivalent to call SendBytes/SendText method.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

SendText Method (ICMPPort Class)

Sends data to the remote host.

Syntax

• C++
• Objective-C
• C

ANSI (Cross Platform)
int SendText(const char* lpszText);

Unicode (Windows)
INT SendText(LPCWSTR lpszText);

- (void)sendText:(NSString*)text;

int ipworks_icmpport_sendtext(void* lpObj, const char* lpszText);

Remarks

This method sends data to the remote host. Calling this method is equivalent to call SendBytes/SendText method.

Error Handling (C++)

This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)

DataIn Event (ICMPPort Class)

Fired when new ICMP messages come in.

Syntax

• C++
• Objective-C
• C

ANSI (Cross Platform)
virtual int FireDataIn(ICMPPortDataInEventParams *e);

typedef struct {
  int MessageType;
  int MessageSubType;
  const char *MessageData;
  int lenMessageData;
  int Checksum;
  const char *SourceAddress;
  int reserved;
} ICMPPortDataInEventParams;


Unicode (Windows)
virtual INT FireDataIn(ICMPPortDataInEventParams *e);

typedef struct {
  INT MessageType;
  INT MessageSubType;
  LPCSTR MessageData;
  INT lenMessageData;
  INT Checksum;
  LPCWSTR SourceAddress;
  INT reserved;
} ICMPPortDataInEventParams;

- (void)onDataIn:(int)messageType :(int)messageSubType :(NSData*)messageData :(int)checksum :(NSString*)sourceAddress;

#define EID_ICMPPORT_DATAIN 1

virtual INT IPWORKS_CALL FireDataIn(INT &iMessageType, INT &iMessageSubType, LPSTR &lpMessageData, INT &lenMessageData, INT &iChecksum, LPSTR &lpszSourceAddress);

Remarks

The MessageType parameter shows the type of the ICMP messages and MessageSubType its subtype.

The MessageData parameter contains the message data.

The Checksum parameter is True or False depending on the ICMP checksum check on the message.

Note that events are not re-entrant. Performing time consuming operations within this event will prevent it from firing again in a timely manner and may impact overall performance.

Error Event (ICMPPort Class)

Information about errors during data delivery.

Syntax

• C++
• Objective-C
• C

ANSI (Cross Platform)
virtual int FireError(ICMPPortErrorEventParams *e);

typedef struct {
  int ErrorCode;
  const char *Description;
  int reserved;
} ICMPPortErrorEventParams;


Unicode (Windows)
virtual INT FireError(ICMPPortErrorEventParams *e);

typedef struct {
  INT ErrorCode;
  LPCWSTR Description;
  INT reserved;
} ICMPPortErrorEventParams;

- (void)onError:(int)errorCode :(NSString*)description;

#define EID_ICMPPORT_ERROR 2

virtual INT IPWORKS_CALL FireError(INT &iErrorCode, LPSTR &lpszDescription);

Remarks

The Error event is fired in case of exceptional conditions during message processing. Normally the class fails with an error.

ErrorCode contains an error code and Description contains a textual description of the error. For a list of valid error codes and their descriptions, please refer to the Error Codes section.