This commit enhances the OpenThread DNSSD name server/resolver and its
native Discovery Proxy to support queries for arbitrary record
types.
To enable this, a new set of `otPlatDnssd` APIs are introduced for
generic `RecordQuerier`. These APIs mirror the existing APIs in the
OpenThread native mDNS module, allowing direct use of the native mDNS
implementation.
The discovery proxy implementation is updated to start and stop the
mDNS `RecordQuerier` when receiving a query for an arbitrary record
type, passing the first response record back to the client.
The unit tests `test_dnssd_discovery_proxy` and `test_dns_client`
are updated to cover all the newly added behaviors in discovery proxy.
Config `OPENTHREAD_CONFIG_SRP_CLIENT_AUTO_START_DEFAULT_MODE` is
changed to use `1` by default (unless explicitly overridden in
project configs).
It also updates related test scripts to utilize auto-start mode or
explicitly disable it for manual SRP client control, reflecting this
default change.
This commit updates `Dns::ServiceDiscovery::Server` such that when
answering a PTR query with more than one answer, it does not include
additional records. This is to keep the size of the response small.
This commit also updates the test scripts validating browse (PTR
query) function to check the new behavior. In particular, a common
python function `_parse_dns_service_info()` is added to parse service
info in CLI output of "dns browse" or "dns service" commands and
handle if output of "dns browse" does not include service info.
This commit updates the MLE attach process so that in the first attach
cycle device tries a total of six MLE Parent Requests, the first two
to routers only followed by four to routers and REEDs. For example,
the six Parent Request message will be used before device can decide
to act the leader. An MTD in the next attach attempt (if cannot find a
parent in first attempt cycle), will go to the model of two Parent
Requests (first to routers, then to routers/REEDs).
This change impacts the time it takes for a device to start as leader
(due to increased number of Parent Request and wait time). This commit
updates different test scripts to address the change in the wait
time. It adds a new `config.LEADER_STARTUP_DELAY` constants which is
used for wait time for leader to start.
This commit updates `Dns::ServiceDiscovery::Server` to use
case-insensitive string match when comparing DNS names. It also
updates `test_dnssd.py` to use mixed case names when browsing for or
resolving services. This validates the case-insensitive treatment
of names by SRP client and server and DNS-SD server (resolver) and
DNS client.
When a new service with subtypes is added to an existing
host, the SRP server incorrectly merges the subtype service
copies so that the TXT information is lost, i.e. 0-length
TXT record is created.
Moreover, the OT DNS client cannot parse services with
0-length TXT record (instead of ignoring the TXT record
itself) causing that such a service cannot be examined
at all.
The problem is caused by incorrect merging of the service
description structure which is shared across all services
with the same instance name (i.e. among the base type
service and its subtypes).
Signed-off-by: Damian Krolik <damian.krolik@nordicsemi.no>
This commit updates `Dns::ServiceDiscovery::Server` to add support for
browsing a service subtype. In particular, it updates the code which
breaks a DNS name into its components such that it can correctly
parse and accept a service subtype name. It also updates how the
service name compression is done to handle the subtype names.
This commit also updates `Dns::Client` to remove the extra check of
service name (which is already verified) when trying to find a PTR
record for a given service instance name. This change enables browse
for service subtype (parsing the browse response).
This commit also updates and enhances the `test_dnssd.py` script
adding test-cases for browsing for service subtype.
This commit adds a new public `ot` API for parsing an encoded DNS TXT
record data into `TxtEntry` key/value pairs. It also updates the TXT
data iterator model used for going through all TXT entries. The new
iterator definition provides a small buffer to store the key string.
This helps simplify the definition of `otDnsTxtEntry` to use
null-terminated C string for the key. The new parsing APIs are used in
CLI module.
This commit also fixes an issue with `TxtEntry::AppendEntries()` using
incorrect value for the key length.
Finally, this commit adds a test covering the behavior of all
`TxtEntry` related methods (encoding and parsing TXT data) in the unit
test `test_dns`.
This commit enhances the DNS-SD server to handle multiple questions.
Specifically for DNS service resolving query with SRV+TXT questions,
this commit would reply with SRV+TXT+AAAA RRs, so that the service
instance can be fully resolved with one query.
More implementation details:
- This commit enhances NameCompressInfo so that question names can be
compressed together with RR names.
- Full compression is limited to only one instance / service / host
name.
- For any RR type in the question, this commit will exclude it in
additional RRs. For example, if the query contains a AAAA question,
the response won't include any additional AAAA RR, but will only
have AAAA answer(s). The purpose is to avoid duplicate RRs in answer
section and additional section.
This commit implements the DNS-SD server:
- Handle Standard DNS Query from clients
- Supported resource records: PTR, SRV, TXT, AAAA
- Query services from SRP server
- Add tests
- simulation test using DNS client (only test AAAA query)
- OTBR test using dig command to verify all resource records can be
queried successfully
Abtin Keshavarzian