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IPWorks 2022 JavaScript Edition

Version 22.0 [Build 8171]

DNS Class

Properties   Methods   Events   Configuration Settings   Errors  

The DNS class is used to query DNS for record information.

Syntax

ipworks.dns()

Remarks

The DNS class queries a DNS server for records as specified in RFC 1035 and other relevant RFCs. The class property QueryType indicates the record to be queried. Calling Query will initiate the query.

Once the query is complete, a single Response event will fire and the record properties will be filled. StatusCode is the server's success or fail code, and Status is a standard string interpretation of the code.

The records are contained in the Records properties. The programming interface is designed to allow a full walk of the records in the DNS response, including provisions for handling new record types.

The class operates synchronously by default (i.e., it waits for a response before returning control to the caller); however, the class also may operate asynchronously (i.e., return control immediately), by setting Timeout to 0. Please see the Timeout property for more information.

Property List


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

DNSPortThis is the port to connect to on the DNS server.
DNSServerThis is the address of the DNS server.
IdleThe current status of the class.
LocalHostThe name of the local host or user-assigned IP interface through which connections are initiated or accepted.
ProtocolThis protocol is used for the DNS request.
QueryTypeThis is the type of record to query.
RecordsThis is the collection of records in the last response.
RecordSourceThe source of records provided in the Records properties.
RecursiveThis determines whether to ask the DNSServer to recursively query other servers.
RequestIdThis is the Id of the current DNS request.
StatusThis is a standard string interpretation of StatusCode .
StatusCodeThis contains the success or error code for the DNS query.
TimeoutA timeout for the class.

Method List


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

ConfigSets or retrieves a configuration setting.
DoEventsProcesses events from the internal message queue.
GetFieldValueThis gets the value of the field indicated from a record.
InterruptInterrupt the current method.
QueryThis method queries a domain.
ResetReset the class.

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.

ErrorInformation about errors during data delivery.
LogThis event fires once for each log message.
ResponseThis event fires after a DNS query.
SSLServerAuthenticationThis event fires when connecting to the server.
SSLStatusThis shows the progress of the secure connection.

Configuration Settings


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

DoHMethodSpecifies the DNS over HTTPS method.
ResponseTruncatedWhether the response is truncated.
UseDNSAPIDLLWhether to use the system dnsapi.dll on Windows Systems.
UseIDNsWhether to encode hostnames to internationalized domain names.
CaptureIPPacketInfoUsed to capture the packet information.
DelayHostResolutionWhether the hostname is resolved when RemoteHost is set.
DestinationAddressUsed to get the destination address from the packet information.
DontFragmentUsed to set the Don't Fragment flag of outgoing packets.
LocalHostThe name of the local host through which connections are initiated or accepted.
LocalPortThe port in the local host where the class binds.
MaxPacketSizeThe maximum length of the packets that can be received.
QOSDSCPValueUsed to specify an arbitrary QOS/DSCP setting (optional).
QOSTrafficTypeUsed to specify QOS/DSCP settings (optional).
ShareLocalPortIf set to True, allows more than one instance of the class to be active on the same local port.
UseConnectionDetermines whether to use a connected socket.
UseIPv6Whether or not to use IPv6.
AbsoluteTimeoutDetermines whether timeouts are inactivity timeouts or absolute timeouts.
FirewallDataUsed to send extra data to the firewall.
InBufferSizeThe size in bytes of the incoming queue of the socket.
OutBufferSizeThe size in bytes of the outgoing queue of the socket.
BuildInfoInformation about the product's build.
CodePageThe system code page used for Unicode to Multibyte translations.
LicenseInfoInformation about the current license.
UseInternalSecurityAPITells the class whether or not to use the system security libraries or an internal implementation.

DNS.DNSPort Property

This is the port to connect to on the DNS server.

Syntax


 getDNSPort(): number;


 setDNSPort(DNSPort: number): void;


Default Value

53

Remarks

This property contains the port to connect to on the DNS server. A valid port number (a value between 1 and 65535) is required for the connection to take place. The property must be set before a connection is attempted and cannot be changed once a connection is established. Any attempt to change this property while connected will fail with an error.

This property is not available at design time.

DNS.DNSServer Property

This is the address of the DNS server.

Syntax


 getDNSServer(): string;


 setDNSServer(DNSServer: string): void;


Default Value

""

Remarks

This property contains the address of the DNS server. The class attempts to find the default DNS server for the machine where it is installed, and provide it in the DNSServer property. You may change it to any particular DNS server you want to query. While any internet host running a DNS service will suffice, it is preferable to use either the DNS server for your network or the DNS server for the domain that you are querying.

If the class cannot determine the default DNS server address, the property value will be an empty string.

Note: Automatic discovery of the default DNS server is not supported in the Java edition.

This property is not available at design time.

DNS.Idle Property

The current status of the class.

Syntax


 isIdle(): boolean;



Default Value

TRUE

Remarks

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

This property is read-only.

DNS.LocalHost Property

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

Syntax


 getLocalHost(): string;


 setLocalHost(localHost: string): void;


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.

DNS.Protocol Property

This protocol is used for the DNS request.

Syntax


 getProtocol(): DnsProtocols;


 setProtocol(protocol: DnsProtocols): void;


enum DnsProtocols { ptUDP, ptTCP, ptTLS, ptHTTPS }

Default Value

0

Remarks

This property specifies the protocol used for the DNS request when Query is called. Possible values include the following:

0 (ptUDP - default) UDP is used. This is the most commonly used DNS protocol.
1 (ptTCP) TCP is used.
2 (ptTLS) TCP with TLS is used. Set DNSPort to the port that the server uses for TLS connections. Typically this is port 853.
3 (ptHTTPS) HTTP is used. The DNS request is made over HTTP. DNSServer must be set to a URL of a server accepting DNS over HTTPS (DoH) requests. See the DoHMethod configuration setting for additional options when using this protocol.

DNS.QueryType Property

This is the type of record to query.

Syntax


 getQueryType(): DnsQueryTypes;


 setQueryType(queryType: DnsQueryTypes): void;


enum DnsQueryTypes { qtAddress, qtNS, qtMD, qtMF, qtCName, qtSOA, qtMailBox, qtMailGroup, qtMR, qtNULL, qtWKS, qtPointer, qtHostInfo, qtMailInfo, qtMX, qtText, qtRP, qtAFSDB, qtX25, qtISDN, qtRT, qtAAAA, qtSRV, qtNAPTR, qtCERT, qtRevLookup }

Default Value

1

Remarks

Before a query is attempted, this property must be set to the desired record type. The records are defined as follows:

qtAddress (1)Address Records
qtNS (2)Name Server Records
qtMD (3)Mail Destination Records
qtMF (4)Mail Forwarder Records
qtCName (5)Canonical Name Records
qtSOA (6)Start Of Authority Records
qtMailBox (7)MailBox Records
qtMailGroup (8)Mail Group Records
qtMR (9)MailBox Rename Records
qtNULL (10)NULL Records
qtWKS (11)Well-Known Services Records
qtPointer (12)Pointer Records
qtHostInfo (13)Host Information Records
qtMailInfo (14)Mail Information Records
qtMX (15)Mail Exchange Records
qtText (16)Text Records
qtRP (17)Responsible Person Records
qtAFSDB (18)Service Records
qtX25 (19)X25 Records
qtISDN (20)ISDN Records
qtRT (21)Route Through Records
qtAAAA (28)AAAA Record
qtSRV (33)SRV Record (location of services)
qtNAPTR (35)NAPTR Record (Naming Authority Pointer)
qtCERT (37)Certificate Record (e.g., Stores PKIX, SPKI, PGP)
qtRevLookup (100)Reverse Lookup (Reverse Lookup)

This property is not available at design time.

DNS.Records Property

This is the collection of records in the last response.

Syntax


 getRecords(): DNSRecordList;



Default Value

Remarks

Once the query is complete, a single Response event will fire. The following properties will contain the results:

StatusCodeThe success or error code of the DNS query.
StatusA standard string interpretation of StatusCode.
RecordsThe Records in the last DNS response.
RecordSourceThe source (type) of records being listed.

Example (loop through all fields of all records)

For i = 0 to DNSControl.RecordsCount - 1 For j = 0 to DNSControl.RecordFieldCount(i) - 1 DNSControl.Records(i).RecordFieldIndex(i) = j DoSomethingWith(DNSControl.RecordFieldName(i), DNSControl.RecordFieldValue(i)) Next j Next i

This property is read-only and not available at design time.

DNS.RecordSource Property

The source of records provided in the Records properties.

Syntax


 getRecordSource(): DnsRecordSources;


 setRecordSource(recordSource: DnsRecordSources): void;


enum DnsRecordSources { rsAnswerSection, rsNameServerSection, rsAdditionalRecordsSection }

Default Value

0

Remarks

This property contains the source of records provided in the Records properties and can have one of the following values:

rsAnswerSection (0)Records answering the question/query.
rsNameServerSection (1)Records pointing toward an authoritative name server.
rsAdditionalRecordsSection (2)Records holding additional information.

This property is not available at design time.

DNS.Recursive Property

This determines whether to ask the DNSServer to recursively query other servers.

Syntax


 isRecursive(): boolean;


 setRecursive(recursive: boolean): void;


Default Value

TRUE

Remarks

If this property is True, the component will tell the DNS server to perform the query recursively. This means that if the DNS server does not have information about the domain being queried, it will send the request to another DNS server.

This property is not available at design time.

DNS.RequestId Property

This is the Id of the current DNS request.

Syntax


 getRequestId(): number;


 setRequestId(requestId: number): void;


Default Value

1

Remarks

This property is the identifier of the request that generated the current response values. Each time the class makes a DNS query, it generates a unique request identifier to track the response.

If a custom value is needed for RequestId, the property must be set before sending a request. The class increments RequestId automatically after sending each request.

Note: The class fails with an error when a value that is not between 1 and 32,767 is specified.

This property is not available at design time.

DNS.Status Property

This is a standard string interpretation of StatusCode .

Syntax


 getStatus(): string;



Default Value

""

Remarks

This property contains a standard string interpretation of StatusCode. For a list of valid error codes and their descriptions, please see the Error Codes section.

This property is read-only and not available at design time.

DNS.StatusCode Property

This contains the success or error code for the DNS query.

Syntax


 getStatusCode(): number;



Default Value

0

Remarks

This property contains the success or error code for the DNS query. For a list of valid error codes and their descriptions, please see the Error Codes section.

This property is read-only and not available at design time.

DNS.Timeout Property

A timeout for the class.

Syntax


 getTimeout(): number;


 setTimeout(timeout: number): void;


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 class will wait for the operation to complete before returning control. The class will handle any potential WOULDBLOCK errors internally and automatically retry the operation 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 60 seconds.

DNS.config Method

Sets or retrieves a configuration setting.

Syntax

async dns.config(configurationString : string): Promise<string>

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.

DNS.doEvents Method

Processes events from the internal message queue.

Syntax

async dns.doEvents(): Promise<void>

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.

DNS.getFieldValue Method

This gets the value of the field indicated from a record.

Syntax

async dns.getFieldValue(recordIndex : number, fieldName : string): Promise<string>

Remarks

This method will get the value of the DNS record field specified by FieldName from the DNS record at RecordIndex. If no such field exists for that record type, the component fails with an error.

DNS.interrupt Method

Interrupt the current method.

Syntax

async dns.interrupt(): Promise<void>

Remarks

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

DNS.query Method

This method queries a domain.

Syntax

async dns.query(domain : string): Promise<void>

Remarks

This method will query the host Domain for any records of the type in QueryType. After the query, RequestId is the identifier corresponding to the request. Once the query is complete, a single Response event will fire. The following properties will contain the results:

StatusCodeThe success or error code of the DNS query.
StatusA standard string interpretation of StatusCode.
RecordsThe Records in the last DNS response.
RecordSourceThe source (type) of records being listed.

DNS.reset Method

Reset the class.

Syntax

async dns.reset(): Promise<void>

Remarks

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

DNS.Error Event

Information about errors during data delivery.

Syntax

dns.on('Error', listener: (e: {readonly errorCode: number, readonly description: string}) => void )

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.

DNS.Log Event

This event fires once for each log message.

Syntax

dns.on('Log', listener: (e: {readonly logLevel: number, readonly message: string, readonly logType: string}) => void )

Remarks

TBD

DNS.Response Event

This event fires after a DNS query.

Syntax

dns.on('Response', listener: (e: {readonly requestId: number, readonly domain: string, readonly statusCode: number, readonly description: string, readonly authoritative: boolean}) => void )

Remarks

The Response event will fire after a call to Query. The RequestId parameter contains the request Id associated with the original query. Domain is the domain of the query. The Authoritative parameter is true if the response is from an authoritative name server. If there is an error returned by the server, StatusCode and Description provide them.

Once the query is complete, a single Response event will fire. The following properties will contain the results:

StatusCodeThe success or error code of the DNS query.
StatusA standard string interpretation of StatusCode.
RecordsThe Records in the last DNS response.
RecordSourceThe source (type) of records being listed.

DNS.SSLServerAuthentication Event

This event fires when connecting to the server.

Syntax

dns.on('SSLServerAuthentication', listener: (e: {readonly remoteAddress: string, readonly remotePort: number, readonly certEncoded: string, readonly certEncodedB: Uint8Array, readonly certSubject: string, readonly certIssuer: string, readonly status: string, accept: boolean}) => void )

Remarks

This event allows the client to decide whether or not to continue with the connection process. The Accept parameter recommends whether to continue or close the connection. This is just a suggestion: application software must use its own logic to determine whether or not to continue.

When Accept is False, Status shows why the verification failed (otherwise, Status contains the string "OK"). If the client decides to continue, you can override and accept the certificate by setting the Accept parameter to True.

RemoteAddress is the IP address of the server.

RemotePort is the source port of the server.

CertEncoded is the Base64-encoded certificate presented by the server.

CertSubject is the subject of the certificate presented by the server.

CertIssuer is the subject of the issuer of the certificate presented by the server.

Status is the status of the certificate.

Accept defines whether the certificate is accepted.

DNS.SSLStatus Event

This shows the progress of the secure connection.

Syntax

dns.on('SSLStatus', listener: (e: {readonly remoteAddress: string, readonly remotePort: number, readonly message: string}) => void )

Remarks

The event is fired for informational and logging purposes only. It is used to track the progress of the connection.

RemoteAddress is the IP address of the remote machine.

RemotePort is the port of the remote machine.

Message is the log message.

DNSRecord Type

This is a record that is returned by the DNS server.

Remarks

When a Query method is performed by the DNS class, the DNS server returns one or more DNSRecords containing information about the domain you specified. This information is contained in the different fields of the record.

Each record may have multiple FieldNames and corresponding FieldValues. You may iterate through these by setting the FieldIndex field.

Fields

Domain
string

This property contains the domain name associated with the selected response record, at RecordIndex.

FieldCount
number

This property contains the number of properties in the current record.

After a successful query, the field values for each record will be provided in the Records properties.

To retrieve a particular field value for a record, first set to a valid response field index and then query records collection for the value of that field.

FieldIndex
number

This property contains the index of the selected property of the current record. valid values are from 0 to ( -1).

After a successful query, the field values for each record will be provided in the Records properties.

To retrieve a particular field value for a record, first set to a valid response field index and then query records collection for the value of that field.

FieldName
string

This property contains the name of the field selected by . Field names are different depending on the record type. For example, an MX record type will contain two properties: PREFERENCE and EXCHANGE, but an SOA record type contains seven properties.

Field names:

A Records ADDRESS
NS RecordsDNAME
MDMADNAME
MFMADNAME
CNAMECNAME
SOAMNAME
SOARNAME
SOASERIAL
SOAREFRESH
SOARETRY
SOAEXPIRE
SOAMINIMUM
MBMADNAME
MGMGMNAME
MRNEWNAME
NULLNULL
WKSADDRESS
WKSPROTOCOL
WKSSERVICEMAP
PTRPTRDNAME
HINFOCPU
HINFOOS
MINFORMAILBX
MINFOEMAILBX
MXPREFERENCE
MXEXCHANGE
TXTTXT
RPMBOXDNAME
RPTXTDNAME
AFSDBSUBTYPE
AFSDBHOSTNAME
X25PSDNADDRESS
ISDNISDNADDRESS
RTPREFERENCE
RTINTERMEDIATE
AAAAADDRESS
SRVPRIORITY
SRVWEIGHT
SRVPORT
SRVTARGET
NAPTRORDER
NAPTRPRIORITY
NAPTRFLAGS
NAPTRSERVICES
NAPTRREGEXP
NAPTRREPLACEMENT

FieldValue
Uint8Array

This property contains the value of the field selected by .

After a successful query, the field values for each record will be provided in the Records properties.

To retrieve a particular field value for a record, first set to a valid response field index and then query records collection for the value of that field.

FieldValueB
byte[]

This property contains the value of the field selected by .

After a successful query, the field values for each record will be provided in the Records properties.

To retrieve a particular field value for a record, first set to a valid response field index and then query records collection for the value of that field.

RecordData
Uint8Array

This property contains the full record data as received from the DNS server.

After a successful query, the field values for each record will be provided in the Records properties.

To retrieve a particular field value for a record, first set to a valid response field index and then query records collection for the value of that field.

RecordDataB
byte[]

This property contains the full record data as received from the DNS server.

After a successful query, the field values for each record will be provided in the Records properties.

To retrieve a particular field value for a record, first set to a valid response field index and then query records collection for the value of that field.

RecordType
DNSRecordTypes

This property contains the record type.

Record types correspond to QueryType and are defined as follows:

rtAddress (1)Address Record
rtNS (2)Name Server Record
rtMD (3)Mail Destination Record
rtMF (4)Mail Forwarder Record
rtCName (5)Canonical Name Record
rtSOA (6)Start of Authority Record
rtMailBox (7)MailBox Record
rtMailGroup (8)Mail Group Record
rtMR (9)MailBox Rename Record
rtNULL (10)NULL Record
rtWKS (11)Well-Known Services Record
rtPointer (12)Pointer Record
rtHostInfo (13)Host Information Record
rtMailInfo (14)Mail Information Record
rtMX (15)Mail Exchange Record
rtText (16)Text Record
rtRP (17)Responsible Person Record
rtAFSDB (18)Service Record
rtX25 (19)X25 Record
rtISDN (20)ISDN Record
rtRT (21)Route Through Record
rtAAAA (28)AAAA Record
rtSRV (33)SRV Record (Location of Services)
rtNAPTR (35)Naming Authority Pointer Record

RecordTypeName
string

This property contains the string representation of the current record type defined by .

A (1)Address Record
NS (2)Name Server Record
MD (3)Mail Destination Record
MF (4)Mail Forwarder Record
CName (5)Canonical Name Record
SOA (6)Start of Authority Record
MB (7)MailBox Record
MG (8)Mail Group Record
MR (9)MailBox Rename Record
NULL (10)NULL Record
WKS (11)Well-Known Services Record
PTR (12)Pointer Record
HINFO (13)Host Information Record
MINFO (14)Mail Information Record
MX (15)Mail Exchange Record
TXT (16)Text Record
RP (17)Responsible Person Record
AFSDB (18)Service Record
X25 (19)X25 Record
ISDN (20)ISDN Record
RT (21)Route Through Record
AAAA (28)AAAA Record
rtSRV (33)SRV Record (Location of Services)
NAPTR (35)Naming Authority Pointer Record

TTL
number

This property contains the record Time to Live (TTL) value. The TTL specifies the time interval in seconds that the record is valid, or the time interval that the record can be cached before the DNS server should be queried again.

Constructors

public DNSRecord();



Configuration Settings (class ipworks.dns)

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.

DNS Configuration Settings

DoHMethod:   Specifies the DNS over HTTPS method.

This setting may be used to configure the method used when performing DNS over HTTPS (DoH). Possible values are as follows:

0 (default)HTTP POST (DNS Wireformat)
1HTTP GET (DNS Wireformat)
2HTTP GET (JSON)

This setting is applicable only when Protocol is set to ptHTTPS.

ResponseTruncated:   Whether the response is truncated.

This setting may be queried after calling Query to determine if the response from thet DNSServer is truncated. If the response is large and cannot be transferred over UDP, the server may truncate the response. When this setting is True the response is truncated and the request should be attempted again over a different Protocol, such as ptTCP.

UseDNSAPIDLL:   Whether to use the system dnsapi.dll on Windows Systems.

This setting specifies whether to use the system dnsapi.dll when using the class. If True, the class will use the Windows System dnsapi.dll. This may be desirable in some cases to allow querying against the system cache. If set to False (default), the class will use its own DNS implementation to perform queries.

The default value is False.

NOTE: This functionality is only available in Windows.

UseIDNs:   Whether to encode hostnames to internationalized domain names.

This setting specifies whether hostnames containing non-ASCII characters are encoded to internationalized domain names. When set to True if a hostname contains non-ASCII characters it is encoded using Punycode to an IDN.

The default value is False and the hostname will always be used exactly as specified. Note: The CodePage setting must be set to a value capable of interpreting the specified host name. For instance to specify UTF-8 set CodePage to 65001. In the C++ Edition for Windows the *W version of the class must be used. For instance DNSW or HTTPW.

UDPPort Configuration Settings

CaptureIPPacketInfo:   Used to capture the packet information.

If this is set to true, the component will capture the IP packet information.

The default value for this setting is False.

Note: This setting is only available in Windows.

DelayHostResolution:   Whether the hostname is resolved when RemoteHost is set.

This setting specifies whether a hostname is resolved immediately when RemoteHost is set. If true the class will resolve the hostname and the IP address will be present in the RemoteHost property. If false, the hostname is not resolved until needed by the component when a method to connect or send data is called. If desired, ResolveRemoteHost may called to manually resolve the value in RemoteHost at any time.

The default value is false.

DestinationAddress:   Used to get the destination address from the packet information.

If CaptureIPPacketInfo is set to true, then this will be populated with the packet's destination address when a packet is received. This information will be accessible in the DataIn event.

Note: This setting is only available in Windows.

DontFragment:   Used to set the Don't Fragment flag of outgoing packets.

When set to True, packets sent by the class will have the Don't Fragment flag set. The default value is False.

LocalHost:   The name of the local host through which connections are initiated or accepted.

The LocalHost setting 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 setting 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).

LocalPort:   The port in the local host where the class binds.

This must be set before a connection is attempted. It instructs the class to bind to a specific port (or communication endpoint) in the local machine.

Setting this to 0 (default) enables the system to choose a port at random. The chosen port will be shown by LocalPort after the connection is established.

LocalPort cannot be changed once a connection is made. Any attempt to set this when a connection is active will generate an error.

This; setting is useful when trying to connect to services that require a trusted port in the client side. An example is the remote shell (rsh) service in UNIX systems.

MaxPacketSize:   The maximum length of the packets that can be received.

This setting specifies the maximum size of the datagrams that the class will accept without truncation.

QOSDSCPValue:   Used to specify an arbitrary QOS/DSCP setting (optional).

UseConnection must be True to use this setting. This option allows you to specify an arbitrary DSCP value between 0 and 63. The default is 0. When set to the default value the component will not set a DSCP value.

Note: This setting uses the qWAVE API is only available on Windows 7, Windows Server 2008 R2, and later.

QOSTrafficType:   Used to specify QOS/DSCP settings (optional).

UseConnection must be True to use this setting. You may specify either the text or integer values: BestEffort (0), Background (1), ExcellentEffort (2), AudioVideo (3), Voice (4), and Control (5).

Note: This setting uses the qWAVE API which is only available on Windows Vista and Windows Server 2008 or above.

Note: QOSTrafficType must be set before setting Active to true.

ShareLocalPort:   If set to True, allows more than one instance of the class to be active on the same local port.

This option must be set before the class is activated through the Active property or it will have no effect.

The default value for this setting is False.

UseConnection:   Determines whether to use a connected socket.

UseConnection specifies whether the class should use a connected socket or not. The connection is defined as an association in between the local address/port and the remote address/port. As such, this is not a connection in the traditional TCP sense. What it means is only that the class will send and receive data only to and from the specified destination.

The default value for this setting is False.

UseIPv6:   Whether or not to use IPv6.

By default, the component expects an IPv4 address for local and remote host properties, and will create an IPv4 socket. To use IPv6 instead, set this to True.

Socket Configuration Settings

AbsoluteTimeout:   Determines whether timeouts are inactivity timeouts or absolute timeouts.

If AbsoluteTimeout is set to True, any method which does not complete within Timeout seconds will be aborted. By default, AbsoluteTimeout is False, and the timeout is an inactivity timeout.

Note: This option is not valid for UDP ports.

FirewallData:   Used to send extra data to the firewall.

When the firewall is a tunneling proxy, use this property to send custom (additional) headers to the firewall (e.g. headers for custom authentication schemes).

InBufferSize:   The size in bytes of the incoming queue of the socket.

This is the size of an internal queue in the TCP/IP stack. You can increase or decrease its size depending on the amount of data that you will be receiving. Increasing the value of the InBufferSize setting can provide significant improvements in performance in some cases.

Some TCP/IP implementations do not support variable buffer sizes. If that is the case, when the class is activated the InBufferSize reverts to its defined size. The same happens if you attempt to make it too large or too small.

OutBufferSize:   The size in bytes of the outgoing queue of the socket.

This is the size of an internal queue in the TCP/IP stack. You can increase or decrease its size depending on the amount of data that you will be sending. Increasing the value of the OutBufferSize setting can provide significant improvements in performance in some cases.

Some TCP/IP implementations do not support variable buffer sizes. If that is the case, when the class is activated the OutBufferSize reverts to its defined size. The same happens if you attempt to make it too large or too small.

Base Configuration Settings

BuildInfo:   Information about the product's build.

When queried, this setting will return a string containing information about the product's build.

CodePage:   The system code page used for Unicode to Multibyte translations.

The default code page is Unicode UTF-8 (65001).

The following is a list of valid code page identifiers:

IdentifierName
037IBM EBCDIC - U.S./Canada
437OEM - United States
500IBM EBCDIC - International
708Arabic - ASMO 708
709Arabic - ASMO 449+, BCON V4
710Arabic - Transparent Arabic
720Arabic - Transparent ASMO
737OEM - Greek (formerly 437G)
775OEM - Baltic
850OEM - Multilingual Latin I
852OEM - Latin II
855OEM - Cyrillic (primarily Russian)
857OEM - Turkish
858OEM - Multilingual Latin I + Euro symbol
860OEM - Portuguese
861OEM - Icelandic
862OEM - Hebrew
863OEM - Canadian-French
864OEM - Arabic
865OEM - Nordic
866OEM - Russian
869OEM - Modern Greek
870IBM EBCDIC - Multilingual/ROECE (Latin-2)
874ANSI/OEM - Thai (same as 28605, ISO 8859-15)
875IBM EBCDIC - Modern Greek
932ANSI/OEM - Japanese, Shift-JIS
936ANSI/OEM - Simplified Chinese (PRC, Singapore)
949ANSI/OEM - Korean (Unified Hangul Code)
950ANSI/OEM - Traditional Chinese (Taiwan; Hong Kong SAR, PRC)
1026IBM EBCDIC - Turkish (Latin-5)
1047IBM EBCDIC - Latin 1/Open System
1140IBM EBCDIC - U.S./Canada (037 + Euro symbol)
1141IBM EBCDIC - Germany (20273 + Euro symbol)
1142IBM EBCDIC - Denmark/Norway (20277 + Euro symbol)
1143IBM EBCDIC - Finland/Sweden (20278 + Euro symbol)
1144IBM EBCDIC - Italy (20280 + Euro symbol)
1145IBM EBCDIC - Latin America/Spain (20284 + Euro symbol)
1146IBM EBCDIC - United Kingdom (20285 + Euro symbol)
1147IBM EBCDIC - France (20297 + Euro symbol)
1148IBM EBCDIC - International (500 + Euro symbol)
1149IBM EBCDIC - Icelandic (20871 + Euro symbol)
1200Unicode UCS-2 Little-Endian (BMP of ISO 10646)
1201Unicode UCS-2 Big-Endian
1250ANSI - Central European
1251ANSI - Cyrillic
1252ANSI - Latin I
1253ANSI - Greek
1254ANSI - Turkish
1255ANSI - Hebrew
1256ANSI - Arabic
1257ANSI - Baltic
1258ANSI/OEM - Vietnamese
1361Korean (Johab)
10000MAC - Roman
10001MAC - Japanese
10002MAC - Traditional Chinese (Big5)
10003MAC - Korean
10004MAC - Arabic
10005MAC - Hebrew
10006MAC - Greek I
10007MAC - Cyrillic
10008MAC - Simplified Chinese (GB 2312)
10010MAC - Romania
10017MAC - Ukraine
10021MAC - Thai
10029MAC - Latin II
10079MAC - Icelandic
10081MAC - Turkish
10082MAC - Croatia
12000Unicode UCS-4 Little-Endian
12001Unicode UCS-4 Big-Endian
20000CNS - Taiwan
20001TCA - Taiwan
20002Eten - Taiwan
20003IBM5550 - Taiwan
20004TeleText - Taiwan
20005Wang - Taiwan
20105IA5 IRV International Alphabet No. 5 (7-bit)
20106IA5 German (7-bit)
20107IA5 Swedish (7-bit)
20108IA5 Norwegian (7-bit)
20127US-ASCII (7-bit)
20261T.61
20269ISO 6937 Non-Spacing Accent
20273IBM EBCDIC - Germany
20277IBM EBCDIC - Denmark/Norway
20278IBM EBCDIC - Finland/Sweden
20280IBM EBCDIC - Italy
20284IBM EBCDIC - Latin America/Spain
20285IBM EBCDIC - United Kingdom
20290IBM EBCDIC - Japanese Katakana Extended
20297IBM EBCDIC - France
20420IBM EBCDIC - Arabic
20423IBM EBCDIC - Greek
20424IBM EBCDIC - Hebrew
20833IBM EBCDIC - Korean Extended
20838IBM EBCDIC - Thai
20866Russian - KOI8-R
20871IBM EBCDIC - Icelandic
20880IBM EBCDIC - Cyrillic (Russian)
20905IBM EBCDIC - Turkish
20924IBM EBCDIC - Latin-1/Open System (1047 + Euro symbol)
20932JIS X 0208-1990 & 0121-1990
20936Simplified Chinese (GB2312)
21025IBM EBCDIC - Cyrillic (Serbian, Bulgarian)
21027Extended Alpha Lowercase
21866Ukrainian (KOI8-U)
28591ISO 8859-1 Latin I
28592ISO 8859-2 Central Europe
28593ISO 8859-3 Latin 3
28594ISO 8859-4 Baltic
28595ISO 8859-5 Cyrillic
28596ISO 8859-6 Arabic
28597ISO 8859-7 Greek
28598ISO 8859-8 Hebrew
28599ISO 8859-9 Latin 5
28605ISO 8859-15 Latin 9
29001Europa 3
38598ISO 8859-8 Hebrew
50220ISO 2022 Japanese with no halfwidth Katakana
50221ISO 2022 Japanese with halfwidth Katakana
50222ISO 2022 Japanese JIS X 0201-1989
50225ISO 2022 Korean
50227ISO 2022 Simplified Chinese
50229ISO 2022 Traditional Chinese
50930Japanese (Katakana) Extended
50931US/Canada and Japanese
50933Korean Extended and Korean
50935Simplified Chinese Extended and Simplified Chinese
50936Simplified Chinese
50937US/Canada and Traditional Chinese
50939Japanese (Latin) Extended and Japanese
51932EUC - Japanese
51936EUC - Simplified Chinese
51949EUC - Korean
51950EUC - Traditional Chinese
52936HZ-GB2312 Simplified Chinese
54936Windows XP: GB18030 Simplified Chinese (4 Byte)
57002ISCII Devanagari
57003ISCII Bengali
57004ISCII Tamil
57005ISCII Telugu
57006ISCII Assamese
57007ISCII Oriya
57008ISCII Kannada
57009ISCII Malayalam
57010ISCII Gujarati
57011ISCII Punjabi
65000Unicode UTF-7
65001Unicode UTF-8

The following is a list of valid code page identifiers for Mac OS only:

IdentifierName
1ASCII
2NEXTSTEP
3JapaneseEUC
4UTF8
5ISOLatin1
6Symbol
7NonLossyASCII
8ShiftJIS
9ISOLatin2
10Unicode
11WindowsCP1251
12WindowsCP1252
13WindowsCP1253
14WindowsCP1254
15WindowsCP1250
21ISO2022JP
30MacOSRoman
10UTF16String
0x90000100UTF16BigEndian
0x94000100UTF16LittleEndian
0x8c000100UTF32String
0x98000100UTF32BigEndian
0x9c000100UTF32LittleEndian
65536Proprietary

LicenseInfo:   Information about the current license.

When queried, this setting will return a string containing information about the license this instance of a class is using. It will return the following information:

  • Product: The product the license is for.
  • Product Key: The key the license was generated from.
  • License Source: Where the license was found (e.g., RuntimeLicense, License File).
  • License Type: The type of license installed (e.g., Royalty Free, Single Server).
UseInternalSecurityAPI:   Tells the class whether or not to use the system security libraries or an internal implementation.

By default the class will use the system security libraries to perform cryptographic functions. Setting this to True tells the class to use the internal implementation instead of using the system's security API.

Trappable Errors (class ipworks.dns)

DNS Errors

100   No records were found.
220   Invalid record index.
221   Invalid field index for record type.
222   Invalid record source.
223   Unknown record type.
224   Could not determine DNS server address.
225   Could not parse address.

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

UDPPort Errors

104   UDPPort is already Active.
106   You cannot change the LocalPort while the class is Active.
107   You cannot change the LocalHost at this time. A connection is in progress.
109   The class must be Active for this operation.
112   Cannot change MaxPacketSize while the class is Active.
113   Cannot change ShareLocalPort option while the class is Active.
114   Cannot change RemoteHost when UseConnection is set and the class Active.
115   Cannot change RemotePort when UseConnection is set and the class is Active.
116   RemotePort can't be zero when UseConnection is set. Please specify a valid service port number.
117   Cannot change UseConnection while the class is Active.
118   Message can't be longer than MaxPacketSize.
119   Message too short.
434   Unable to convert string to selected CodePage

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).

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IPWorks 2022 JavaScript Edition - Version 22.0 [Build 8171]