samples: net: dns: Add LLMNR client support to DNS resolver

By default the LLMNR is disabled in this sample. You can enable
it by setting CONFIG_LLMNR_RESOLVER=y

Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>

samples/net/dns_resolve/README.rst

@@ -17,6 +17,10 @@ The multicast DNS (mDNS) client resolver support can be enabled by setting
 CONFIG_MDNS_RESOLVER Kconfig variable.
 See https://tools.ietf.org/html/rfc6762 for more details about mDNS.
 
+The link-local multicast name resolution (LLMNR) client resolver support can be
+enabled by setting the :option:`CONFIG_LLMNR_RESOLVER` Kconfig option.
+See https://tools.ietf.org/html/rfc4795 for more details about LLMNR.
+
 For more information about DNS configuration variables, see:
 :file:`subsys/net/lib/dns/Kconfig`. The DNS resolver API can be found at
 :file:`include/net/dns_resolve.h`. The sample code can be found at:

samples/net/dns_resolve/prj.conf

@@ -34,6 +34,8 @@ CONFIG_DNS_RESOLVER_ADDITIONAL_BUF_CTR=5
 CONFIG_DNS_RESOLVER_ADDITIONAL_QUERIES=2
 # Enable mDNS support
 CONFIG_MDNS_RESOLVER=y
+# Enable LLMNR support
+CONFIG_LLMNR_RESOLVER=n
 
 CONFIG_DNS_RESOLVER_MAX_SERVERS=2
 CONFIG_DNS_SERVER_IP_ADDRESSES=y

samples/net/dns_resolve/sample.yaml

@@ -1,13 +1,24 @@
-sample:
-  description: DNS resolver sample application
-  name: DNS Resolver
 common:
   harness: net
   depends_on: netif
   tags: net dns
+sample:
+  description: DNS resolver, mDNS and LLMNR responder
+  name: DNS resolver and responder sample application
 tests:
-  test:
+  test_mdns:
     extra_configs:
+      - CONFIG_MDNS_RESOLVER=y
+      - CONFIG_LLMNR_RESOLVER=n
       - CONFIG_NET_DHCPV4=y
       - CONFIG_NET_DEBUG_APP=y
       - CONFIG_SYS_LOG_NET_LEVEL=4
+    tags: mdns
+  test_llmnr:
+    extra_configs:
+      - CONFIG_MDNS_RESOLVER=n
+      - CONFIG_LLMNR_RESOLVER=y
+      - CONFIG_NET_DHCPV4=y
+      - CONFIG_NET_DEBUG_APP=y
+      - CONFIG_SYS_LOG_NET_LEVEL=4
+    tags: llmnr