ICMP Class

Properties   Methods   Events   Config Settings   Errors  

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

Syntax

class ipworks.ICMP

Remarks

The interface of the class is similar to the interface of TCPClient, only it is much simpler. The class is activated/deactivated by using the active property. This property enables or disables the sending or receiving of data. Data can be sent in the same way as TCPClient, using the send method and Text parameter or the data_to_send property. The destination is specified using the remote_host property. The class automatically creates an ICMP header containing message_type, message_sub_type, and a checksum for the message.

If the UseConnection configuration 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 can 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 on_data_in 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 with using blocking calls.

Property List

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

Method List

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

Event List

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

Config Settings

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

accept_data Property

This property enables or disables data reception (the DataIn event).

Syntax

def get_accept_data() -> bool: ...
def set_accept_data(value: bool) -> None: ...

accept_data = property(get_accept_data, set_accept_data)

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 on_data_in event). Setting this property to True, reenables data reception.

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

active Property

This property indicates whether the class is active.

Syntax

def get_active() -> bool: ...
def set_active(value: bool) -> None: ...

active = property(get_active, set_active)

Default Value

FALSE

Remarks

This property indicates whether the class is currently active and can send or receive data.

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

Note: Use the activate or deactivate method to control whether the class is active.

data_to_send Property

This write-only property includes a string of data to be sent to the remote host.

Syntax

def set_data_to_send(value: bytes) -> None: ...

data_to_send = property(None, set_data_to_send)

Default Value

""

Remarks

This property is write-only and contains a string of data to be sent to the remote host. Assigning a string to this property makes the class send the string to the remote host. The send method provides similar functionality.

The Transmission Control Protocol (TCP)/IP subsystem attempts to send the string assigned to this property as a complete message. If socket buffers are full, or if the message cannot be delivered for any other reason, an error is fired, and no portion of the message is sent. This is different from TCP in which case portions of the messages can be sent. ICMP sends either a complete message or nothing at all.

If you are sending data to the remote host faster than it can process it, or faster than the network's bandwidth allows, the outgoing queue might fill up. When this happens, data_to_send fails with error 10035: "[10035] Operation would block" (WSAEWOULDBLOCK). You can check this error, and then try to send the data again. .

This property is write-only.

dont_route Property

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

Syntax

def get_dont_route() -> bool: ...
def set_dont_route(value: bool) -> None: ...

dont_route = property(get_dont_route, set_dont_route)

Default Value

FALSE

Remarks

If this property is set to True, it forces the socket to send data directly to the 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.

local_host Property

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

Syntax

def get_local_host() -> str: ...
def set_local_host(value: str) -> None: ...

local_host = property(get_local_host, set_local_host)

Default Value

""

Remarks

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

message_sub_type Property

This property is the subtype of the ICMP message (part of the ICMP header).

Syntax

def get_message_sub_type() -> int: ...
def set_message_sub_type(value: int) -> None: ...

message_sub_type = property(get_message_sub_type, set_message_sub_type)

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 message_type.

Types and subtypes of ICMP messages are defined in the various internet RFCs and other documentation associated with Transmission Control Protocol (TCP)/IP.

message_type Property

This property includes the type of the ICMP message (part of the ICMP header).

Syntax

def get_message_type() -> int: ...
def set_message_type(value: int) -> None: ...

message_type = property(get_message_type, set_message_type)

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 data_to_send.

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

remote_host Property

This property includes the address of the RemoteHost. Domain names are resolved to IP addresses.

Syntax

def get_remote_host() -> str: ...
def set_remote_host(value: str) -> None: ...

remote_host = property(get_remote_host, set_remote_host)

Default Value

""

Remarks

This property specifies the IP address (IP number in dotted internet format) or the 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. 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).

timeout Property

A timeout for the class.

Syntax

def get_timeout() -> int: ...
def set_timeout(value: int) -> None: ...

timeout = property(get_timeout, set_timeout)

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 do_events 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).

time_to_live Property

This property includes the time-to-live (TTL) value for the ICMP packets sent by the class.

Syntax

def get_time_to_live() -> int: ...
def set_time_to_live(value: int) -> None: ...

time_to_live = property(get_time_to_live, set_time_to_live)

Default Value

0

Remarks

This method contains the time-to-live (TTL) value for the ICMP packets sent by the class. The 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 value is effectively a hop count limit on how far a datagram can propagate through the internet. When the TTL value is reduced to zero (or less), the packet is discarded.

If the value of the property is set to zero, then the default TTL value of the underlying Transmission Control Protocol (TCP)/IP subsystem will be used.

activate Method

This method enables sending and receiving of data.

Syntax

def activate() -> None: ...

Remarks

This method enables sending and receiving of data. When called, the class will create a communication endpoint (socket) that 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 also is created.

config Method

Sets or retrieves a configuration setting.

Syntax

def config(configuration_string: str) -> str: ...

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.

deactivate Method

This method disables sending and receiving of data.

Syntax

def deactivate() -> None: ...

Remarks

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

do_events Method

Processes events from the internal message queue.

Syntax

def do_events() -> None: ...

Remarks

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

pause_data Method

This method pauses data reception.

Syntax

def pause_data() -> None: ...

Remarks

This method pauses data reception when called. While data reception is paused, the on_data_in event will not fire. Call process_data to reenable data reception.

process_data Method

This method reenables data reception after a call to PauseData .

Syntax

def process_data() -> None: ...

Remarks

This method reenables data reception after a previous call to pause_data. When pause_data is called, the on_data_in event will not fire. To reenable data reception and allow on_data_in to fire, call this method.

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

reset Method

Reset the class.

Syntax

def reset() -> None: ...

Remarks

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

resolve_remote_host Method

Resolves the hostname in RemoteHost to an IP address.

Syntax

def resolve_remote_host() -> None: ...

Remarks

This method resolves the hostname specified by remote_host to an IP address. The resolved value is available in the remote_host 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 remote_host if desired.

send Method

This method sends data to the remote host.

Syntax

def send(text: bytes) -> None: ...

Remarks

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

send_bytes Method

This method sends data to the remote host.

Syntax

def send_bytes(data: bytes) -> None: ...

Remarks

This method sends data to the remote host. Calling this method is equivalent to calling the send_bytes/send_text method.

send_text Method

This method sends data to the remote host.

Syntax

def send_text(text: str) -> None: ...

Remarks

This method sends data to the remote host. Calling this method is equivalent to calling the send_bytes/send_text method.

on_data_in Event

This event is fired when a new ICMP messages come in.

Syntax

class ICMPDataInEventParams(object):
  @property
  def message_type() -> int: ...

  @property
  def message_sub_type() -> int: ...

  @property
  def message_data() -> bytes: ...

  @property
  def checksum() -> int: ...

  @property
  def source_address() -> str: ...

# In class ICMP:
@property
def on_data_in() -> Callable[[ICMPDataInEventParams], None]: ...
@on_data_in.setter
def on_data_in(event_hook: Callable[[ICMPDataInEventParams], None]) -> None: ...

Remarks

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

The MessageData parameter contains the message data.

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

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

on_error Event

Fired when information is available about errors during data delivery.

Syntax

class ICMPErrorEventParams(object):
  @property
  def error_code() -> int: ...

  @property
  def description() -> str: ...

# In class ICMP:
@property
def on_error() -> Callable[[ICMPErrorEventParams], None]: ...
@on_error.setter
def on_error(event_hook: Callable[[ICMPErrorEventParams], None]) -> None: ...

Remarks

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

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

on_ready_to_send Event

Fired when the class is ready to send data.

Syntax

class ICMPReadyToSendEventParams(object):
# In class ICMP:
@property
def on_ready_to_send() -> Callable[[ICMPReadyToSendEventParams], None]: ...
@on_ready_to_send.setter
def on_ready_to_send(event_hook: Callable[[ICMPReadyToSendEventParams], None]) -> None: ...

Remarks

The on_ready_to_send event indicates that the underlying TCP/IP subsystem is ready to accept data after a failed data_to_send.

ICMP Config Settings

The class accepts one or more of the following configuration settings. Configuration 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.

ICMP Config Settings

Socket Config Settings

Base Config Settings

ICMP Errors

ICMP Errors

	104   The class is already active.
	107   Cannot change the LocalHost at this time. A connection is in progress.
	109   The class must be active for this operation.
	112   Cannot change MaxMessageSize while ICMP is active.
	114   Cannot change remote_host when UseConnection is set and the class is active.
	117   Cannot change UseConnection while the class is active.
	118   The message cannot be longer than MaxMessageSize.
	119   The message is too short.
	120   Cannot create ICMP handle.

SSL Errors

	270   Cannot load specified security library.
	271   Cannot open certificate store.
	272   Cannot find specified certificate.
	273   Cannot acquire security credentials.
	274   Cannot find certificate chain.
	275   Cannot verify certificate chain.
	276   Error during handshake.
	280   Error verifying certificate.
	281   Could not find client certificate.
	282   Could not find server certificate.
	283   Error encrypting data.
	284   Error decrypting data.

TCP/IP Errors

	10004   [10004] Interrupted system call.
	10009   [10009] Bad file number.
	10013   [10013] Access denied.
	10014   [10014] Bad address.
	10022   [10022] Invalid argument.
	10024   [10024] Too many open files.
	10035   [10035] Operation would block.
	10036   [10036] Operation now in progress.
	10037   [10037] Operation already in progress.
	10038   [10038] Socket operation on non-socket.
	10039   [10039] Destination address required.
	10040   [10040] Message too long.
	10041   [10041] Protocol wrong type for socket.
	10042   [10042] Bad protocol option.
	10043   [10043] Protocol not supported.
	10044   [10044] Socket type not supported.
	10045   [10045] Operation not supported on socket.
	10046   [10046] Protocol family not supported.
	10047   [10047] Address family not supported by protocol family.
	10048   [10048] Address already in use.
	10049   [10049] Can't assign requested address.
	10050   [10050] Network is down.
	10051   [10051] Network is unreachable.
	10052   [10052] Net dropped connection or reset.
	10053   [10053] Software caused connection abort.
	10054   [10054] Connection reset by peer.
	10055   [10055] No buffer space available.
	10056   [10056] Socket is already connected.
	10057   [10057] Socket is not connected.
	10058   [10058] Can't send after socket shutdown.
	10059   [10059] Too many references, can't splice.
	10060   [10060] Connection timed out.
	10061   [10061] Connection refused.
	10062   [10062] Too many levels of symbolic links.
	10063   [10063] File name too long.
	10064   [10064] Host is down.
	10065   [10065] No route to host.
	10066   [10066] Directory not empty
	10067   [10067] Too many processes.
	10068   [10068] Too many users.
	10069   [10069] Disc Quota Exceeded.
	10070   [10070] Stale NFS file handle.
	10071   [10071] Too many levels of remote in path.
	10091   [10091] Network subsystem is unavailable.
	10092   [10092] WINSOCK DLL Version out of range.
	10093   [10093] Winsock not loaded yet.
	11001   [11001] Host not found.
	11002   [11002] Non-authoritative 'Host not found' (try again or check DNS setup).
	11003   [11003] Non-recoverable errors: FORMERR, REFUSED, NOTIMP.
	11004   [11004] Valid name, no data record (check DNS setup).