This commit updates the unit tests that emulate the radio platform API
to define `otPlatRadioGetCaps()`, which returns the ACK_TIMEOUT and
CSMA capabilities. This is to avoid having CSMA being implemented by
the `SubMac`, which then uses the microsecond timer that is not
emulated in the unit test platform.
It also updates the `InitTest()` function to clear the radio platform
variable `sRadioTxOngoing`. This is to avoid the possible
(though unlikely) situation where an earlier test finishes in the
middle of a transmission, causing an extra `TxDone` event in the
following test.
This commit adds `otDnsClientResolveServiceAndHostAddress()` function
as a new DNS Client API. This function starts a DNS service instance
resolution for a given service instance, with a potential follow-up
address resolution for the host name discovered for the service
instance (when the server/resolver does not provide AAAA/A records
for the host name in the response to SRV query).
In order to test the behavior of the newly added function, `TestMode`
in `Dns::ServiceDiscovery::Server` is updated to add a new mode where
no RR is added in the Additional Data section of a DNS query response.
This commit adds a related CLI command for the new API and updates
`test_dns_client` to validate the behavior of new API using the new
`TestMode` on `Server`.
This commit updates DNS client to add `otDnsServiceMode` to the
`otDnsQueryConfig`. This new config property determines which records
to query and allow the API user to control the behavior during
service resolution: We can query for SRV record only or TXT record
only, or query for both SRV and TXT records in the same message, or
in parallel in different messages, or an "optimized" mode where
client will first try to query for both records together in the same
message but if server responds with an error, it then retries using
two parallel separate queries.
This gives flexibility and control to the API user. It also helps
address situations where the server (DNS resolver) may not accept
queries with more than one questions.
To support this new feature, this commit updates and enhances the
internal design of the `Dns::Client`. A new mechanism is added to
allow multiple `Query` instances to be associated with each other
under a main `Query` and responses for the related queries are saved
until all are received and validated before finalizing the main
`Query` and invoking the callback and allowing caller to retrieve the
info.
This commit also adds a detailed unit test `test_dns_client` which
covers DNS client browse and service resolution validating behavior
under all service modes. In order to test `Client` functionality,
this commit also adds a `TestMode` in `Dns::ServiceDiscovery::Server`
allowing us to change server behavior, e.g., reject messages with
more than one question in query.
Jonathan Hui