DNSv6

This module includes functions that control DNS communication.

Summary

Typedefs
`otDnsQuery`	typedef `struct otDnsQuery` This structure implements DNS Query parameters.
`otDnsResponseHandler)(void aContext, const char aHostname, otIp6Address *aAddress, uint32_t aTtl, otError aResult)`	typedef `void(*` This function pointer is called when a DNS response is received.

Functions
`otDnsClientQuery(otInstance aInstance, const otDnsQuery aQuery, otDnsResponseHandler aHandler, void *aContext)`	`otError` This function sends a DNS query for AAAA (IPv6) record.

Structs
otDnsQuery	This structure implements DNS Query parameters.

struct otDnsQuery otDnsQuery

This structure implements DNS Query parameters.

void(* otDnsResponseHandler)(void *aContext, const char *aHostname, otIp6Address *aAddress, uint32_t aTtl, otError aResult)

This function pointer is called when a DNS response is received.

Details

Parameters

`[in] aContext`	A pointer to application-specific context.
`[in] aHostname`	Identifies hostname related with DNS response.
`[in] aAddress`	A pointer to the IPv6 address received in DNS response. May be null.
`[in] aTtl`	Specifies the maximum time in seconds that the resource record may be cached.
`[in] aResult`	A result of the DNS transaction.

Return Values

`OT_ERROR_NONE`	A response was received successfully and IPv6 address is provided in `aAddress`.
`OT_ERROR_ABORT`	A DNS transaction was aborted by stack.
`OT_ERROR_RESPONSE_TIMEOUT`	No DNS response has been received within timeout.
`OT_ERROR_NOT_FOUND`	A response was received but no IPv6 address has been found.
`OT_ERROR_FAILED`	A response was received but status code is different than success.

otError otDnsClientQuery(
  otInstance *aInstance,
  const otDnsQuery *aQuery,
  otDnsResponseHandler aHandler,
  void *aContext
)

This function sends a DNS query for AAAA (IPv6) record.

This function is available only if feature OPENTHREAD_CONFIG_DNS_CLIENT_ENABLE is enabled.

Details

Parameters

`[in] aInstance`	A pointer to an OpenThread instance.
`[in] aQuery`	A pointer to specify DNS query parameters.
`[in] aHandler`	A function pointer that shall be called on response reception or time-out.
`[in] aContext`	A pointer to arbitrary context information.

 OT_DNS_DEFAULT_SERVER_IP "2001:4860:4860::8888"

Defines default DNS Server address - Google DNS.

 OT_DNS_DEFAULT_SERVER_PORT 53

Defines default DNS Server port.

 OT_DNS_MAX_HOSTNAME_LENGTH 62

Maximum allowed hostname length (maximum label size - 1 for compression).