[thci] improve mDNS browsing using Zeroconf (#7249)

Previous approach with `dig` was not enough because it was only parsing one mDNS response and not taking account that the response could be from an inactive Border Router. Use Python Zeroconf to properly parse all services.
2026-06-06 05:24:51 +00:00 · 2021-12-23 21:55:47 +01:00
parent b7c40afb66
commit f10e662692
1 changed files with 64 additions and 21 deletions
@@ -618,31 +618,74 @@ EOF"
    def mdns_query(self, dst='ff02::fb', service='_meshcop._udp.local', addrs_blacklist=[]):
        print('mdns_query %s %s %s' % (dst, service, addrs_blacklist))

-        result = self.bash('dig -p 5353 @%s %s ptr +time=2 +retry=2' % (dst, service))
-
+        # For BBR-TC-03 or DH test cases just send a query
        if dst == 'ff02::fb' and not addrs_blacklist:
-            return (0, '')
+            self.bash('dig -p 5353 @%s %s ptr' % (dst, service))
+            return

-        # Remove responses from unwanted devices
-        responses = ' '.join(result).split(';; ANSWER SECTION:')
-        for response in responses:
-            if not set(response.split()).isdisjoint(set(addrs_blacklist)):
-                break
+        # For MATN-TC-17 and MATN-TC-18 use Zeroconf to get the BBR address and border agent port
+        from zeroconf import ServiceBrowser, ServiceStateChange, Zeroconf, DNSAddress, DNSService, DNSText

-        # Records patterns:
-        # raspberrypi-2.local.	10	IN	AAAA	fe80::81:46ff:fe0d:bfe.43684
-        # OpenThread_BorderRouter._meshcop._udp.local. 10\tIN SRV 0 0 49153 raspberrypi.local.
-        try:
-            addr = response.split('AAAA\tfe80')[1].split(' ')[0]
-            addr = 'fe80%s%%eth0' % addr
-        except Exception:
-            raise Exception('Unable to find the DUT address in the mDNS response')
-        try:
-            port = int(response.split('IN SRV')[1].split(' ')[3])
-        except Exception:
-            raise Exception('Unable to find the DUT port in the mDNS response')
+        def on_service_state_change(zeroconf, service_type, name, state_change):
+            if state_change is ServiceStateChange.Added:
+                zeroconf.get_service_info(service_type, name)

-        return (addr, port)
+        class BorderAgent(object):
+            alias = None
+            server_name = None
+            link_local_addr = None
+            port = None
+            thread_status = None
+
+            def __init__(self, alias):
+                self.alias = alias
+
+            def __repr__(self):
+                return '%s # [%s]:%s TIS=%s' % (self.alias, self.link_local_addr, self.port, self.thread_status)
+
+        def parse_cache(cache):
+            border_agents = []
+
+            # Find all border routers
+            for ptr in cache['_meshcop._udp.local.']:
+                border_agents.append(BorderAgent(ptr.alias))
+
+            # Find server name, port and Thread Interface status for each border router
+            for ba in border_agents:
+                for record in cache[ba.alias.lower()]:
+                    if isinstance(record, DNSService):
+                        ba.server_name = record.server
+                        ba.port = record.port
+                    elif isinstance(record, DNSText):
+                        text = bytearray(record.text)
+                        sb = text.split(b'sb=')[1][0:4]
+                        ba.thread_status = (sb[3] & 0x18) >> 3
+
+            # Find link local address for each border router
+            for ba in border_agents:
+                for record in cache[ba.server_name]:
+                    if isinstance(record, DNSAddress):
+                        addr = ipaddress.ip_address(record.address)
+                        if addr.is_link_local:
+                            ba.link_local_addr = str(addr)
+                            break
+
+            return border_agents
+
+        # Browse border agents
+        zeroconf = Zeroconf()
+        ServiceBrowser(zeroconf, "_meshcop._udp.local.", handlers=[on_service_state_change])
+        time.sleep(2)
+        cache = zeroconf.cache.cache
+        zeroconf.close()
+
+        # Find an active border agent not in the blacklist
+        border_agents = parse_cache(cache)
+        for ba in border_agents:
+            if ba.thread_status == 2 and ba.link_local_addr not in addrs_blacklist:
+                return ('%s%%eth0' % ba.link_local_addr, ba.port)
+
+        raise Exception('No active Border Agents found')

    # Override powerDown
    @API