DNS Component
Properties Methods Events Config Settings Errors
The DNS component is used to query DNS for record information.
Syntax
TipwDNS
Remarks
The DNS component queries a DNS server for records as specified in RFC 1035 and other relevant RFCs. The component 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 component operates synchronously by default (i.e., it waits for a response before returning control to the caller); however, the component 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 component with short descriptions. Click on the links for further details.
DNSPort | This is the port to connect to on the DNS server. |
DNSServer | This is the address of the DNS server. |
Idle | This property specifies the current status of the component. |
LocalHost | This property includes the name of the local host or user-assigned IP interface through which connections are initiated or accepted. |
Protocol | This protocol is used for the DNS request. |
QueryType | This is the type of record to query. |
RecordCount | The number of records in the Record arrays. |
RecordDomain | This property contains the domain name associated with the selected response record, at RecordIndex . |
RecordFieldCount | This property contains the number of properties in the current record. |
RecordFieldIndex | This property contains the index of the selected property of the current record. |
RecordFieldName | This property contains the name of the property selected by FieldIndex . |
RecordFieldValue | This property contains the value of the property selected by FieldIndex . |
RecordData | This property contains the full record data as received from the DNS server. |
RecordType | This property contains the record type. |
RecordTypeName | This property contains the string representation of the current record type defined by RecordType . |
RecordTTL | This property contains the record Time to Live (TTL) value. |
RecordSource | The source of records provided in the Records properties. |
Recursive | This determines whether to ask the DNSServer to recursively query other servers. |
RequestId | This is the Id of the current DNS request. |
Status | This is a standard string interpretation of StatusCode . |
StatusCode | This contains the success or error code for the DNS query. |
Timeout | This property includes the timeout for the component. |
Method List
The following is the full list of the methods of the component with short descriptions. Click on the links for further details.
Config | Sets or retrieves a configuration setting. |
DoEvents | This method processes events from the internal message queue. |
GetFieldValue | This gets the value of the field indicated from a record. |
Interrupt | This method interrupts the current method. |
Query | This method queries a domain. |
Reset | This method will reset the component. |
Event List
The following is the full list of the events fired by the component with short descriptions. Click on the links for further details.
Error | Fired when information is available about errors during data delivery. |
Log | This event fires once for each log message. |
Response | This event fires after a DNS query. |
SSLServerAuthentication | This event fires when connecting to the server. |
SSLStatus | This shows the progress of the secure connection. |
Config Settings
The following is a list of config settings for the component with short descriptions. Click on the links for further details.
DoHMethod | Specifies the DNS over HTTPS method. |
ResponseTruncated | Whether the response is truncated. |
UseDNSAPIDLL | Whether to use the system dnsapi.dll on Windows Systems. |
UseIDNs | Whether to encode hostnames to internationalized domain names. |
CaptureIPPacketInfo | Used to capture the packet information. |
DelayHostResolution | Whether the hostname is resolved when RemoteHost is set. |
DestinationAddress | Used to get the destination address from the packet information. |
DontFragment | Used to set the Don't Fragment flag of outgoing packets. |
LocalHost | The name of the local host through which connections are initiated or accepted. |
LocalPort | The port in the local host where the component binds. |
MaxPacketSize | The maximum length of the packets that can be received. |
QOSDSCPValue | Used to specify an arbitrary QOS/DSCP setting (optional). |
QOSTrafficType | Used to specify QOS/DSCP settings (optional). |
ShareLocalPort | If set to True, allows more than one instance of the component to be active on the same local port. |
UseConnection | Determines whether to use a connected socket. |
UseIPv6 | Whether or not to use IPv6. |
AbsoluteTimeout | Determines whether timeouts are inactivity timeouts or absolute timeouts. |
FirewallData | Used to send extra data to the firewall. |
InBufferSize | The size in bytes of the incoming queue of the socket. |
OutBufferSize | The size in bytes of the outgoing queue of the socket. |
BuildInfo | Information about the product's build. |
CodePage | The system code page used for Unicode to Multibyte translations. |
LicenseInfo | Information about the current license. |
MaskSensitiveData | Whether sensitive data is masked in log messages. |
UseInternalSecurityAPI | Whether or not to use the system security libraries or an internal implementation. |
DNSPort Property (DNS Component)
This is the port to connect to on the DNS server.
Syntax
__property int DNSPort = { read=FDNSPort, write=FSetDNSPort };
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.
Data Type
Integer
DNSServer Property (DNS Component)
This is the address of the DNS server.
Syntax
__property String DNSServer = { read=FDNSServer, write=FSetDNSServer };
Default Value
""
Remarks
This property contains the address of the DNS server. The component 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 component 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.
Data Type
String
Idle Property (DNS Component)
This property specifies the current status of the component.
Syntax
__property bool Idle = { read=FIdle };
Default Value
True
Remarks
Idle 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
Boolean
LocalHost Property (DNS Component)
This property includes the name of the local host or user-assigned IP interface through which connections are initiated or accepted.
Syntax
__property String LocalHost = { read=FLocalHost, write=FSetLocalHost };
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 multihomed hosts (machines with more than one IP interface) setting LocalHost to the IP address of an interface will make the component initiate connections (or accept in the case of server components) 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 component 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 multihomed 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
Protocol Property (DNS Component)
This protocol is used for the DNS request.
Syntax
__property TipwDNSProtocols Protocol = { read=FProtocol, write=FSetProtocol };
enum TipwDNSProtocols { ptUDP=0, ptTCP=1, ptTLS=2, ptHTTPS=3 };
Default Value
ptUDP
Remarks
This property specifies the protocol used for the DNS request when Query is called. Possible values include the following:
0 (ptUDP - default) | User Datagram Protocol (UDP) is used. This is the most commonly used DNS protocol. |
1 (ptTCP) | Transmission Control Protocol (TCP) is used. |
2 (ptTLS) | TCP with Transport Layer Security (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. |
Data Type
Integer
QueryType Property (DNS Component)
This is the type of record to query.
Syntax
__property TipwDNSQueryTypes QueryType = { read=FQueryType, write=FSetQueryType };
enum TipwDNSQueryTypes { qtAddress=1, qtNS=2, qtMD=3, qtMF=4, qtCName=5, qtSOA=6, qtMailBox=7, qtMailGroup=8, qtMR=9, qtNULL=10, qtWKS=11, qtPointer=12, qtHostInfo=13, qtMailInfo=14, qtMX=15, qtText=16, qtRP=17, qtAFSDB=18, qtX25=19, qtISDN=20, qtRT=21, qtAAAA=28, qtSRV=33, qtNAPTR=35, qtCERT=37, qtRevLookup=100 };
Default Value
qtAddress
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.
Data Type
Integer
RecordCount Property (DNS Component)
The number of records in the Record arrays.
Syntax
__property int RecordCount = { read=FRecordCount };
Default Value
0
Remarks
This property controls the size of the following arrays:
- RecordData
- RecordDomain
- RecordFieldCount
- RecordFieldIndex
- RecordFieldName
- RecordFieldValue
- RecordTTL
- RecordType
- RecordTypeName
This property is read-only and not available at design time.
Data Type
Integer
RecordDomain Property (DNS Component)
This property contains the domain name associated with the selected response record, at RecordIndex .
Syntax
__property String RecordDomain[int RecordIndex] = { read=FRecordDomain };
Default Value
""
Remarks
This property contains the domain name associated with the selected response record, at RecordIndex.
The RecordIndex parameter specifies the index of the item in the array. The size of the array is controlled by the RecordCount property.
This property is read-only and not available at design time.
Data Type
String
RecordFieldCount Property (DNS Component)
This property contains the number of properties in the current record.
Syntax
__property int RecordFieldCount[int RecordIndex] = { read=FRecordFieldCount };
Default Value
0
Remarks
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 RecordFieldIndex to a valid response field index and then query records collection for the value of that field.
The RecordIndex parameter specifies the index of the item in the array. The size of the array is controlled by the RecordCount property.
This property is read-only and not available at design time.
Data Type
Integer
RecordFieldIndex Property (DNS Component)
This property contains the index of the selected property of the current record.
Syntax
__property int RecordFieldIndex[int RecordIndex] = { read=FRecordFieldIndex, write=FSetRecordFieldIndex };
Default Value
1
Remarks
This property contains the index of the selected property of the current record. RecordFieldIndex valid values are from 0 to (RecordFieldCount -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 RecordFieldIndex to a valid response field index and then query records collection for the value of that field.
The RecordIndex parameter specifies the index of the item in the array. The size of the array is controlled by the RecordCount property.
This property is not available at design time.
Data Type
Integer
RecordFieldName Property (DNS Component)
This property contains the name of the property selected by FieldIndex .
Syntax
__property String RecordFieldName[int RecordIndex] = { read=FRecordFieldName };
Default Value
"0"
Remarks
This property contains the name of the field selected by RecordFieldIndex. 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 Records | DNAME |
MD | MADNAME |
MF | MADNAME |
CNAME | CNAME |
SOA | MNAME |
SOA | RNAME |
SOA | SERIAL |
SOA | REFRESH |
SOA | RETRY |
SOA | EXPIRE |
SOA | MINIMUM |
MB | MADNAME |
MG | MGMNAME |
MR | NEWNAME |
NULL | NULL |
WKS | ADDRESS |
WKS | PROTOCOL |
WKS | SERVICEMAP |
PTR | PTRDNAME |
HINFO | CPU |
HINFO | OS |
MINFO | RMAILBX |
MINFO | EMAILBX |
MX | PREFERENCE |
MX | EXCHANGE |
TXT | TXT |
RP | MBOXDNAME |
RP | TXTDNAME |
AFSDB | SUBTYPE |
AFSDB | HOSTNAME |
X25 | PSDNADDRESS |
ISDN | ISDNADDRESS |
RT | PREFERENCE |
RT | INTERMEDIATE |
AAAA | ADDRESS |
SRV | PRIORITY |
SRV | WEIGHT |
SRV | PORT |
SRV | TARGET |
NAPTR | ORDER |
NAPTR | PRIORITY |
NAPTR | FLAGS |
NAPTR | SERVICES |
NAPTR | REGEXP |
NAPTR | REPLACEMENT |
The RecordIndex parameter specifies the index of the item in the array. The size of the array is controlled by the RecordCount property.
This property is read-only and not available at design time.
Data Type
String
RecordFieldValue Property (DNS Component)
This property contains the value of the property selected by FieldIndex .
Syntax
__property String RecordFieldValue[int RecordIndex] = { read=FRecordFieldValue }; __property DynamicArray<Byte> RecordFieldValueB[int RecordIndex] = { read=FRecordFieldValueB };
Default Value
""
Remarks
This property contains the value of the field selected by RecordFieldIndex.
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 RecordFieldIndex to a valid response field index and then query records collection for the value of that field.
The RecordIndex parameter specifies the index of the item in the array. The size of the array is controlled by the RecordCount property.
This property is read-only and not available at design time.
Data Type
Byte Array
RecordData Property (DNS Component)
This property contains the full record data as received from the DNS server.
Syntax
__property String RecordData[int RecordIndex] = { read=FRecordData }; __property DynamicArray<Byte> RecordDataB[int RecordIndex] = { read=FRecordDataB };
Default Value
""
Remarks
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 RecordFieldIndex to a valid response field index and then query records collection for the value of that field.
The RecordIndex parameter specifies the index of the item in the array. The size of the array is controlled by the RecordCount property.
This property is read-only and not available at design time.
Data Type
Byte Array
RecordType Property (DNS Component)
This property contains the record type.
Syntax
__property TipwDNSRecordTypes RecordType[int RecordIndex] = { read=FRecordType };
enum TipwDNSRecordTypes { rtAddress=1, rtNS=2, rtMD=3, rtMF=4, rtCName=5, rtSOA=6, rtMailBox=7, rtMailGroup=8, rtMR=9, rtNULL=10, rtWKS=11, rtPointer=12, rtHostInfo=13, rtMailInfo=14, rtMX=15, rtText=16, rtRP=17, rtAFSDB=18, rtX25=19, rtISDN=20, rtRT=21, rtAAAA=28, rtSRV=33, rtNAPTR=35 };
Default Value
rtAddress
Remarks
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 |
The RecordIndex parameter specifies the index of the item in the array. The size of the array is controlled by the RecordCount property.
This property is read-only and not available at design time.
Data Type
Integer
RecordTypeName Property (DNS Component)
This property contains the string representation of the current record type defined by RecordType .
Syntax
__property String RecordTypeName[int RecordIndex] = { read=FRecordTypeName };
Default Value
""
Remarks
This property contains the string representation of the current record type defined by RecordType.
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 |
The RecordIndex parameter specifies the index of the item in the array. The size of the array is controlled by the RecordCount property.
This property is read-only and not available at design time.
Data Type
String
RecordTTL Property (DNS Component)
This property contains the record Time to Live (TTL) value.
Syntax
__property int RecordTTL[int RecordIndex] = { read=FRecordTTL };
Default Value
0
Remarks
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.
The RecordIndex parameter specifies the index of the item in the array. The size of the array is controlled by the RecordCount property.
This property is read-only and not available at design time.
Data Type
Integer
RecordSource Property (DNS Component)
The source of records provided in the Records properties.
Syntax
__property TipwDNSRecordSources RecordSource = { read=FRecordSource, write=FSetRecordSource };
enum TipwDNSRecordSources { rsAnswerSection=0, rsNameServerSection=1, rsAdditionalRecordsSection=2 };
Default Value
rsAnswerSection
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.
Data Type
Integer
Recursive Property (DNS Component)
This determines whether to ask the DNSServer to recursively query other servers.
Syntax
__property bool Recursive = { read=FRecursive, write=FSetRecursive };
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.
Data Type
Boolean
RequestId Property (DNS Component)
This is the Id of the current DNS request.
Syntax
__property int RequestId = { read=FRequestId, write=FSetRequestId };
Default Value
1
Remarks
This property is the identifier of the request that generated the current response values. Each time the component 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 component increments RequestId automatically after sending each request.
Note: The component raises an exception when a value that is not between 1 and 32,767 is specified.
This property is not available at design time.
Data Type
Integer
Status Property (DNS Component)
This is a standard string interpretation of StatusCode .
Syntax
__property String Status = { read=FStatus };
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.
Data Type
String
StatusCode Property (DNS Component)
This contains the success or error code for the DNS query.
Syntax
__property int StatusCode = { read=FStatusCode };
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.
Data Type
Integer
Timeout Property (DNS Component)
This property includes the timeout for the component.
Syntax
__property int Timeout = { read=FTimeout, write=FSetTimeout };
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 component will wait for the operation to complete before returning control. The component will handle any potential WOULDBLOCK errors internally and automatically retry the operation for a maximum of Timeout seconds.
The component 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 component raises an exception.
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
Integer
Config Method (DNS Component)
Sets or retrieves a configuration setting.
Syntax
String __fastcall Config(String ConfigurationString);
Remarks
Config is a generic method available in every component. It is used to set and retrieve configuration settings for the component.
These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the component, 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.
DoEvents Method (DNS Component)
This method processes events from the internal message queue.
Syntax
void __fastcall DoEvents();
Remarks
When DoEvents is called, the component processes any available events. If no events are available, it waits for a preset period of time, and then returns.
GetFieldValue Method (DNS Component)
This gets the value of the field indicated from a record.
Syntax
String __fastcall GetFieldValue(int RecordIndex, String FieldName);
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 raises an exception.
Interrupt Method (DNS Component)
This method interrupts the current method.
Syntax
void __fastcall Interrupt();
Remarks
If there is no method in progress, Interrupt simply returns, doing nothing.
Query Method (DNS Component)
This method queries a domain.
Syntax
void __fastcall Query(String Domain);
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:
StatusCode | The success or error code of the DNS query. |
Status | A standard string interpretation of StatusCode. |
Records | The Records in the last DNS response. |
RecordSource | The source (type) of records being listed. |
Reset Method (DNS Component)
This method will reset the component.
Syntax
void __fastcall Reset();
Remarks
This method will reset the component's properties to their default values.
Error Event (DNS Component)
Fired when information is available about errors during data delivery.
Syntax
typedef struct { int ErrorCode; String Description; } TipwDNSErrorEventParams; typedef void __fastcall (__closure *TipwDNSErrorEvent)(System::TObject* Sender, TipwDNSErrorEventParams *e); __property TipwDNSErrorEvent OnError = { read=FOnError, write=FOnError };
Remarks
The Error event is fired in case of exceptional conditions during message processing. Normally the component raises an exception.
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.
Log Event (DNS Component)
This event fires once for each log message.
Syntax
typedef struct { int LogLevel; String Message; String LogType; } TipwDNSLogEventParams; typedef void __fastcall (__closure *TipwDNSLogEvent)(System::TObject* Sender, TipwDNSLogEventParams *e); __property TipwDNSLogEvent OnLog = { read=FOnLog, write=FOnLog };
Remarks
This event fires once for each log message generated by the component. The verbosity is controlled by the LogLevel setting.
LogLevel indicates the level of message. Possible values are as follows:
0 (None) | No events are logged. |
1 (Info - default) | Informational events are logged. |
2 (Verbose) | Detailed data are logged. |
3 (Debug) | Debug data are logged. |
The value 1 (Info) logs basic information, including the URL, HTTP version, and status details.
The value 2 (Verbose) logs additional information about the request and response.
The value 3 (Debug) logs the headers and body for both the request and response, as well as additional debug information (if any).
Message is the log entry.
LogType identifies the type of log entry. Possible values are as follows:
- "Info"
- "RequestHeaders"
- "ResponseHeaders"
- "RequestBody"
- "ResponseBody"
- "ProxyRequest"
- "ProxyResponse"
- "FirewallRequest"
- "FirewallResponse"
Response Event (DNS Component)
This event fires after a DNS query.
Syntax
typedef struct { int RequestId; String Domain; int StatusCode; String Description; bool Authoritative; } TipwDNSResponseEventParams; typedef void __fastcall (__closure *TipwDNSResponseEvent)(System::TObject* Sender, TipwDNSResponseEventParams *e); __property TipwDNSResponseEvent OnResponse = { read=FOnResponse, write=FOnResponse };
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:
StatusCode | The success or error code of the DNS query. |
Status | A standard string interpretation of StatusCode. |
Records | The Records in the last DNS response. |
RecordSource | The source (type) of records being listed. |
SSLServerAuthentication Event (DNS Component)
This event fires when connecting to the server.
Syntax
typedef struct { String RemoteAddress; int RemotePort; String CertEncoded; DynamicArray<Byte> CertEncodedB; String CertSubject; String CertIssuer; String Status; bool Accept; } TipwDNSSSLServerAuthenticationEventParams; typedef void __fastcall (__closure *TipwDNSSSLServerAuthenticationEvent)(System::TObject* Sender, TipwDNSSSLServerAuthenticationEventParams *e); __property TipwDNSSSLServerAuthenticationEvent OnSSLServerAuthentication = { read=FOnSSLServerAuthentication, write=FOnSSLServerAuthentication };
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.
SSLStatus Event (DNS Component)
This shows the progress of the secure connection.
Syntax
typedef struct { String RemoteAddress; int RemotePort; String Message; } TipwDNSSSLStatusEventParams; typedef void __fastcall (__closure *TipwDNSSSLStatusEvent)(System::TObject* Sender, TipwDNSSSLStatusEventParams *e); __property TipwDNSSSLStatusEvent OnSSLStatus = { read=FOnSSLStatus, write=FOnSSLStatus };
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.
Config Settings (DNS Component)
The component 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 component, access to these internal properties is provided through the Config method.DNS Config Settings
0 (default) | HTTP POST (DNS Wireformat) |
1 | HTTP GET (DNS Wireformat) |
2 | HTTP GET (JSON) |
The default value is False.
Note: This functionality is only available in Windows.
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.
UDP Config Settings
The default value for this setting is False.
Note: This configuration setting is available only in Windows.
The default value is false.
Note: This configuration setting is available only in Windows.
In multihomed hosts (machines with more than one IP interface), setting LocalHost to the value of an interface will make the component initiate connections (or accept in the case of server components) only through that interface.
If the component 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 multihomed hosts (machines with more than one IP interface).
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 configuration setting is useful when trying to connect to services that require a trusted port on the client side. An example is the remote shell (rsh) service in UNIX systems.
Note: This configuration setting uses the qWAVE API and is available only on Windows 7, Windows Server 2008 R2, and later.
Note: This configuration setting uses the qWAVE API and is available only on Windows Vista and Windows Server 2008 or above.
Note: QOSTrafficType must be set before setting Active to True.
The default value for this setting is False.
The default value for this setting is False.
Socket Config Settings
Note: This option is not valid for User Datagram Protocol (UDP) ports.
Some TCP/IP implementations do not support variable buffer sizes. If that is the case, when the component is activated the InBufferSize reverts to its defined size. The same happens if you attempt to make it too large or too small.
Some TCP/IP implementations do not support variable buffer sizes. If that is the case, when the component is activated the OutBufferSize reverts to its defined size. The same happens if you attempt to make it too large or too small.
Base Config Settings
The following is a list of valid code page identifiers:
Identifier | Name |
037 | IBM EBCDIC - U.S./Canada |
437 | OEM - United States |
500 | IBM EBCDIC - International |
708 | Arabic - ASMO 708 |
709 | Arabic - ASMO 449+, BCON V4 |
710 | Arabic - Transparent Arabic |
720 | Arabic - Transparent ASMO |
737 | OEM - Greek (formerly 437G) |
775 | OEM - Baltic |
850 | OEM - Multilingual Latin I |
852 | OEM - Latin II |
855 | OEM - Cyrillic (primarily Russian) |
857 | OEM - Turkish |
858 | OEM - Multilingual Latin I + Euro symbol |
860 | OEM - Portuguese |
861 | OEM - Icelandic |
862 | OEM - Hebrew |
863 | OEM - Canadian-French |
864 | OEM - Arabic |
865 | OEM - Nordic |
866 | OEM - Russian |
869 | OEM - Modern Greek |
870 | IBM EBCDIC - Multilingual/ROECE (Latin-2) |
874 | ANSI/OEM - Thai (same as 28605, ISO 8859-15) |
875 | IBM EBCDIC - Modern Greek |
932 | ANSI/OEM - Japanese, Shift-JIS |
936 | ANSI/OEM - Simplified Chinese (PRC, Singapore) |
949 | ANSI/OEM - Korean (Unified Hangul Code) |
950 | ANSI/OEM - Traditional Chinese (Taiwan; Hong Kong SAR, PRC) |
1026 | IBM EBCDIC - Turkish (Latin-5) |
1047 | IBM EBCDIC - Latin 1/Open System |
1140 | IBM EBCDIC - U.S./Canada (037 + Euro symbol) |
1141 | IBM EBCDIC - Germany (20273 + Euro symbol) |
1142 | IBM EBCDIC - Denmark/Norway (20277 + Euro symbol) |
1143 | IBM EBCDIC - Finland/Sweden (20278 + Euro symbol) |
1144 | IBM EBCDIC - Italy (20280 + Euro symbol) |
1145 | IBM EBCDIC - Latin America/Spain (20284 + Euro symbol) |
1146 | IBM EBCDIC - United Kingdom (20285 + Euro symbol) |
1147 | IBM EBCDIC - France (20297 + Euro symbol) |
1148 | IBM EBCDIC - International (500 + Euro symbol) |
1149 | IBM EBCDIC - Icelandic (20871 + Euro symbol) |
1200 | Unicode UCS-2 Little-Endian (BMP of ISO 10646) |
1201 | Unicode UCS-2 Big-Endian |
1250 | ANSI - Central European |
1251 | ANSI - Cyrillic |
1252 | ANSI - Latin I |
1253 | ANSI - Greek |
1254 | ANSI - Turkish |
1255 | ANSI - Hebrew |
1256 | ANSI - Arabic |
1257 | ANSI - Baltic |
1258 | ANSI/OEM - Vietnamese |
1361 | Korean (Johab) |
10000 | MAC - Roman |
10001 | MAC - Japanese |
10002 | MAC - Traditional Chinese (Big5) |
10003 | MAC - Korean |
10004 | MAC - Arabic |
10005 | MAC - Hebrew |
10006 | MAC - Greek I |
10007 | MAC - Cyrillic |
10008 | MAC - Simplified Chinese (GB 2312) |
10010 | MAC - Romania |
10017 | MAC - Ukraine |
10021 | MAC - Thai |
10029 | MAC - Latin II |
10079 | MAC - Icelandic |
10081 | MAC - Turkish |
10082 | MAC - Croatia |
12000 | Unicode UCS-4 Little-Endian |
12001 | Unicode UCS-4 Big-Endian |
20000 | CNS - Taiwan |
20001 | TCA - Taiwan |
20002 | Eten - Taiwan |
20003 | IBM5550 - Taiwan |
20004 | TeleText - Taiwan |
20005 | Wang - Taiwan |
20105 | IA5 IRV International Alphabet No. 5 (7-bit) |
20106 | IA5 German (7-bit) |
20107 | IA5 Swedish (7-bit) |
20108 | IA5 Norwegian (7-bit) |
20127 | US-ASCII (7-bit) |
20261 | T.61 |
20269 | ISO 6937 Non-Spacing Accent |
20273 | IBM EBCDIC - Germany |
20277 | IBM EBCDIC - Denmark/Norway |
20278 | IBM EBCDIC - Finland/Sweden |
20280 | IBM EBCDIC - Italy |
20284 | IBM EBCDIC - Latin America/Spain |
20285 | IBM EBCDIC - United Kingdom |
20290 | IBM EBCDIC - Japanese Katakana Extended |
20297 | IBM EBCDIC - France |
20420 | IBM EBCDIC - Arabic |
20423 | IBM EBCDIC - Greek |
20424 | IBM EBCDIC - Hebrew |
20833 | IBM EBCDIC - Korean Extended |
20838 | IBM EBCDIC - Thai |
20866 | Russian - KOI8-R |
20871 | IBM EBCDIC - Icelandic |
20880 | IBM EBCDIC - Cyrillic (Russian) |
20905 | IBM EBCDIC - Turkish |
20924 | IBM EBCDIC - Latin-1/Open System (1047 + Euro symbol) |
20932 | JIS X 0208-1990 & 0121-1990 |
20936 | Simplified Chinese (GB2312) |
21025 | IBM EBCDIC - Cyrillic (Serbian, Bulgarian) |
21027 | Extended Alpha Lowercase |
21866 | Ukrainian (KOI8-U) |
28591 | ISO 8859-1 Latin I |
28592 | ISO 8859-2 Central Europe |
28593 | ISO 8859-3 Latin 3 |
28594 | ISO 8859-4 Baltic |
28595 | ISO 8859-5 Cyrillic |
28596 | ISO 8859-6 Arabic |
28597 | ISO 8859-7 Greek |
28598 | ISO 8859-8 Hebrew |
28599 | ISO 8859-9 Latin 5 |
28605 | ISO 8859-15 Latin 9 |
29001 | Europa 3 |
38598 | ISO 8859-8 Hebrew |
50220 | ISO 2022 Japanese with no halfwidth Katakana |
50221 | ISO 2022 Japanese with halfwidth Katakana |
50222 | ISO 2022 Japanese JIS X 0201-1989 |
50225 | ISO 2022 Korean |
50227 | ISO 2022 Simplified Chinese |
50229 | ISO 2022 Traditional Chinese |
50930 | Japanese (Katakana) Extended |
50931 | US/Canada and Japanese |
50933 | Korean Extended and Korean |
50935 | Simplified Chinese Extended and Simplified Chinese |
50936 | Simplified Chinese |
50937 | US/Canada and Traditional Chinese |
50939 | Japanese (Latin) Extended and Japanese |
51932 | EUC - Japanese |
51936 | EUC - Simplified Chinese |
51949 | EUC - Korean |
51950 | EUC - Traditional Chinese |
52936 | HZ-GB2312 Simplified Chinese |
54936 | Windows XP: GB18030 Simplified Chinese (4 Byte) |
57002 | ISCII Devanagari |
57003 | ISCII Bengali |
57004 | ISCII Tamil |
57005 | ISCII Telugu |
57006 | ISCII Assamese |
57007 | ISCII Oriya |
57008 | ISCII Kannada |
57009 | ISCII Malayalam |
57010 | ISCII Gujarati |
57011 | ISCII Punjabi |
65000 | Unicode UTF-7 |
65001 | Unicode UTF-8 |
Identifier | Name |
1 | ASCII |
2 | NEXTSTEP |
3 | JapaneseEUC |
4 | UTF8 |
5 | ISOLatin1 |
6 | Symbol |
7 | NonLossyASCII |
8 | ShiftJIS |
9 | ISOLatin2 |
10 | Unicode |
11 | WindowsCP1251 |
12 | WindowsCP1252 |
13 | WindowsCP1253 |
14 | WindowsCP1254 |
15 | WindowsCP1250 |
21 | ISO2022JP |
30 | MacOSRoman |
10 | UTF16String |
0x90000100 | UTF16BigEndian |
0x94000100 | UTF16LittleEndian |
0x8c000100 | UTF32String |
0x98000100 | UTF32BigEndian |
0x9c000100 | UTF32LittleEndian |
65536 | Proprietary |
- 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).
- Last Valid Build: The last valid build number for which the license will work.
This setting only works on these components: AS3Receiver, AS3Sender, Atom, Client(3DS), FTP, FTPServer, IMAP, OFTPClient, SSHClient, SCP, Server(3DS), Sexec, SFTP, SFTPServer, SSHServer, TCPClient, TCPServer.
Setting this configuration setting to true tells the component to use the internal implementation instead of using the system security libraries.
This setting is set to false by default on all platforms.
Trappable Errors (DNS Component)
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 component may also return one of the following error codes, which are inherited from other components.
UDP Errors
104 | UDP is already Active. |
106 | You cannot change the LocalPort while the component is Active. |
107 | You cannot change the LocalHost at this time. A connection is in progress. |
109 | The component must be Active for this operation. |
112 | You cannot change MaxPacketSize while the component is Active. |
113 | You cannot change ShareLocalPort option while the component is Active. |
114 | You cannot change RemoteHost when UseConnection is set and the component Active. |
115 | You cannot change RemotePort when UseConnection is set and the component is Active. |
116 | RemotePort cannot be zero when UseConnection is set. Please specify a valid service port number. |
117 | You cannot change UseConnection while the component is Active. |
118 | Message cannot 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 nonsocket. |
10039 | [10039] Destination address required. |
10040 | [10040] Message is too long. |
10041 | [10041] Protocol wrong type for socket. |
10042 | [10042] Bad protocol option. |
10043 | [10043] Protocol is not supported. |
10044 | [10044] Socket type is not supported. |
10045 | [10045] Operation is not supported on socket. |
10046 | [10046] Protocol family is not supported. |
10047 | [10047] Address family is not supported by protocol family. |
10048 | [10048] Address already in use. |
10049 | [10049] Cannot 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] Cannot send after socket shutdown. |
10059 | [10059] Too many references, cannot splice. |
10060 | [10060] Connection timed out. |
10061 | [10061] Connection refused. |
10062 | [10062] Too many levels of symbolic links. |
10063 | [10063] File name is too long. |
10064 | [10064] Host is down. |
10065 | [10065] No route to host. |
10066 | [10066] Directory is 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 is not loaded yet. |
11001 | [11001] Host not found. |
11002 | [11002] Nonauthoritative 'Host not found' (try again or check DNS setup). |
11003 | [11003] Nonrecoverable errors: FORMERR, REFUSED, NOTIMP. |
11004 | [11004] Valid name, no data record (check DNS setup). |