Struct ipworks::Ping

Properties   Methods   Events   Config Settings   Errors  

The PING struct encapsulates Internet Control Message Protocol (ICMP) ECHO functionality, which is used to check whether there is a communications link between two computers.

Syntax

ipworks::Ping

Remarks

When the ping_host method is called with the Host parameter, or if remote_host is assigned an IP address or domain name, the struct sends an ICMP ECHO packet to the remote host. The response_time and response_source properties are updated with the time of the roundtrip to the remote host and the address of the host actually sending the response.

The struct operates synchronously by default (i.e., waits for a response before returning control to the caller); however, the struct may also operate asynchronously (i.e., returns control immediately) by setting timeout to 0. Please refer to the timeout property for more information.

Object Lifetime

The new() method returns a mutable reference to a struct instance. The object itself is kept in the global list maintained by IPWorks. Due to this, the Ping struct cannot be disposed of automatically. Please, call the dispose(&mut self) method of Ping when you have finished using the instance.

Property List

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

active property (Ping Struct)

This property indicates whether the struct is active.

Syntax

fn active(&self ) -> Result<bool, IPWorksError> 

Default Value

false

Remarks

This property indicates whether the struct is currently active and can send or receive data. Use the activate and deactivate methods to control whether the struct is active.

The ping_host method will automatically change the value of this property to True.

This property is read-only.

Data Type

bool

idle property (Ping Struct)

The current status of the struct.

Syntax

fn idle(&self ) -> Result<bool, IPWorksError> 

Default Value

true

Remarks

This property will be False if the component is currently busy (communicating or waiting for an answer), and True at all other times.

This property is read-only.

Data Type

bool

local_host property (Ping Struct)

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

Syntax

fn local_host(&self ) -> Result<String, IPWorksError> 
fn set_local_host(&self, value : &str) ->  Option<IPWorksError> 
fn set_local_host_ref(&self, value : &String) ->  Option<IPWorksError> 

Default Value

""

Remarks

This 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 multihomed hosts (machines with more than one IP interface) setting LocalHost to the IP address of an interface will make the struct initiate connections (or accept in the case of server structs) only through that interface. It is recommended to provide an IP address rather than a hostname when setting this property to ensure the desired interface is used.

If the struct 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 multihomed 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.

Data Type

String

packet_size property (Ping Struct)

This property includes the size of the packet to send as the ping request.

Syntax

fn packet_size(&self ) -> Result<i32, IPWorksError> 
fn set_packet_size(&self, value : i32) ->  Option<IPWorksError> 

Default Value

64

Remarks

This property allows you to control the size of the data packet sent in the ping_host method. The default packet size is 64 bytes, with a minimum of 8 bytes (4 bytes of the ICMP header plus the ECHO identifier). The maximum value is 65520.

Data Type

i32

remote_host property (Ping Struct)

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

Syntax

fn remote_host(&self ) -> Result<String, IPWorksError> 
fn set_remote_host(&self, value : &str) ->  Option<IPWorksError> 
fn set_remote_host_ref(&self, value : &String) ->  Option<IPWorksError> 

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 struct 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 struct fails with an error.

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

Data Type

String

request_id property (Ping Struct)

This property includes a unique identifier for outgoing packets.

Syntax

fn request_id(&self ) -> Result<i32, IPWorksError> 

Default Value

0

Remarks

This property contains a unique identifier for outgoing packets. This property is useful during asynchronous ping operations. The RequestId parameter of the on_response event is used to match requests with responses.

The identifier of the outgoing ping packet is provided in this property after the ping_host method returns.

This property is read-only.

Data Type

i32

response_source property (Ping Struct)

This property includes the source of the last PING response.

Syntax

fn response_source(&self ) -> Result<String, IPWorksError> 

Default Value

""

Remarks

This property contains the address of the host responding to the PING (ICMP ECHO) request. This may or may not be the host used in ping_host.

This property is read-only.

Data Type

String

response_status property (Ping Struct)

This property includes the status of the last PING response.

Syntax

fn response_status(&self ) -> Result<String, IPWorksError> 

Default Value

""

Remarks

This property contains the status of the last response. After ping_host has returned, this property will be populated with the status of the response. For responses without error, the value will be OK. In the case of an error, the value will hold a description of the error, such as Network Unreachable or Host Unreachable.

This property is read-only.

Data Type

String

response_time property (Ping Struct)

This property includes the time elapsed between sending the original packet and the remote host reply.

Syntax

fn response_time(&self ) -> Result<i32, IPWorksError> 

Default Value

0

Remarks

This property contains the time elapsed between sending the original packet and the remote host reply. The time value is expressed in milliseconds. The lowest resolution available depends on the resolution of the clock on the host system (normally between 10 ms and 20 ms).

This property is read-only.

Data Type

i32

timeout property (Ping Struct)

This property includes the timeout for the struct.

Syntax

fn timeout(&self ) -> Result<i32, IPWorksError> 
fn set_timeout(&self, value : i32) ->  Option<IPWorksError> 

Default Value

60

Remarks

If the timeout property is set to 0, all operations return immediately, potentially failing with a WOULDBLOCK error if data cannot be sent immediately.

If timeout is set to a positive value, data is sent in a blocking manner and the struct will wait for the operation to complete before returning control. The struct will handle any potential WOULDBLOCK errors internally and automatically retry the operation for a maximum of timeout seconds.

The struct 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 struct fails with an error.

NOTE: By default, all timeouts are inactivity timeouts, that is, 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 60 seconds.

Data Type

i32

time_to_live property (Ping Struct)

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

Syntax

fn time_to_live(&self ) -> Result<i32, IPWorksError> 
fn set_time_to_live(&self, value : i32) ->  Option<IPWorksError> 

Default Value

0

Remarks

This method contains the time-to-live (TTL) value for the ICMP packets sent by the struct. 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.

Data Type

i32

type_of_service property (Ping Struct)

This property includes the type of ICMP message sent as a ping request.

Syntax

fn type_of_service(&self ) -> Result<i32, IPWorksError> 
fn set_type_of_service(&self, value : i32) ->  Option<IPWorksError> 

Default Value

8

Remarks

This property contains the type of the ICMP message sent as a ping request. The default value is 8 (ECHO REQUEST).

Data Type

i32

activate method (Ping Struct)

This method enables sending and receiving data.

Syntax

fn activate(&self) -> Result<(), IPWorksError>

Remarks

This method enables sending and receiving of data.

NOTE: Calling the ping_host method will automatically activate the struct.

config method (Ping Struct)

Sets or retrieves a configuration setting.

Syntax

fn config(&self, configuration_string : &str) ->  Result<String, IPWorksError>

Remarks

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

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the struct, 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 (Ping Struct)

This method disables sending and receiving data.

Syntax

fn deactivate(&self) -> Result<(), IPWorksError>

Remarks

This method disables sending and receiving data.

do_events method (Ping Struct)

This method processes events from the internal message queue.

Syntax

fn do_events(&self) -> Result<(), IPWorksError>

Remarks

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

interrupt method (Ping Struct)

This method interrupts the current method.

Syntax

fn interrupt(&self) -> Result<(), IPWorksError>

Remarks

If there is no method in progress, interrupt simply returns, doing nothing.

ping_host method (Ping Struct)

This method pings a host.

Syntax

fn ping_host(&self, host : &str) -> Result<(), IPWorksError>

Remarks

This method will ping a host. A valid internet domain name or address must be specified in host, or an error will be returned.

A PING request (ICMP ECHO) is sent to the host.

Example. Ping a Host:

PingControl.PingHost("MyHostName") ResponseTime = PingControl.ResponseTime

reset method (Ping Struct)

This method will reset the struct.

Syntax

fn reset(&self) -> Result<(), IPWorksError>

Remarks

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

resolve_remote_host method (Ping Struct)

This method resolves the hostname in RemoteHost to an IP address.

Syntax

fn resolve_remote_host(&self) -> Result<(), IPWorksError>

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 struct will resolve the hostname automatically when needed. If DelayHostResolution is true, this method may be called to manually resolve remote_host, if desired.

wake_on_lan method (Ping Struct)

This method sends a Wake-On-LAN packet.

Syntax

fn wake_on_lan(&self, remote_host : &str, mac_address : &str) -> Result<(), IPWorksError>

Remarks

When this method is called, a Wake-On-LAN packet is sent to remote_host (which may also be a broadcast address). This has the effect of powering on the machine (if such functionality is supported by the network card on the remote machine).

The physical address of the remote host must be supplied in the mac_address parameter.

on_error event (Ping Struct)

Fired when information is available about errors during data delivery.

Syntax

// PingErrorEventArgs carries the Ping Error event's parameters.
pub struct PingErrorEventArgs {
  fn error_code(&self) -> i32
  fn description(&self) -> &String
}

// PingErrorEvent defines the signature of the Ping Error event's handler function.
pub trait PingErrorEvent {
  fn on_error(&self, sender : Ping, e : &mut PingErrorEventArgs);
}

impl <'a> Ping<'a> {
  pub fn on_error(&self) -> &'a dyn PingErrorEvent;
  pub fn set_on_error(&mut self, value : &'a dyn PingErrorEvent);
  ...
}

Remarks

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

The error_code 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_response event (Ping Struct)

This event is fired when a response packet is received.

Syntax

// PingResponseEventArgs carries the Ping Response event's parameters.
pub struct PingResponseEventArgs {
  fn request_id(&self) -> i32
  fn response_source(&self) -> &String
  fn response_status(&self) -> &String
  fn response_time(&self) -> i32
}

// PingResponseEvent defines the signature of the Ping Response event's handler function.
pub trait PingResponseEvent {
  fn on_response(&self, sender : Ping, e : &mut PingResponseEventArgs);
}

impl <'a> Ping<'a> {
  pub fn on_response(&self) -> &'a dyn PingResponseEvent;
  pub fn set_on_response(&mut self, value : &'a dyn PingResponseEvent);
  ...
}

Remarks

The request_id parameter is used along with the request_id property to match requests with responses.

response_status is set to OK for normal operation, or it contains an error string, such as Network unreachable or Host unreachable.

Config Settings (Ping Struct)

The struct 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 struct, access to these internal properties is provided through the config method.

Ping Config Settings

ICMP Config Settings

Socket Config Settings

Base Config Settings

Trappable Errors (Ping Struct)

Ping Errors

The class may also return one of the following error codes, which are inherited from other classes.

ICMP Errors

SSL Errors

TCP/IP Errors