Implement uri-queries for .well-known/core resources

README.md

@@ -8,9 +8,8 @@ which aims to be conformant with:
  - CoRE link format [RFC 6690](https://tools.ietf.org/rfc/rfc6690.txt)
 
 The following features are not (yet) implemented:
- - DTLS
- - Proxying
- - Uri Query
+ - DTLS transport
+ - Proxying and virtual servers (Uri-Host, Uri-Port, Proxy-Uri and Proxy-Scheme options)
 
 It was tested with the following CoAP implementations:
  - C [libcoap](https://www.libcoap.net/) (develop branch)
@@ -48,6 +47,7 @@ The tool accepts the following arguments:
 Run the example simply by:
 
     $ ./coap-client.sh coap://127.0.0.1/.well-known/core
+    $ ./coap-client.sh coap://127.0.0.1/.well-known/core?rt=core.ps
     $ ./coap-client.sh coap://127.0.0.1/resource
     $ ./coap-client.sh coap://127.0.0.1/resource -s 1000
     $ ./coap-client.sh -m put coap://127.0.0.1/resource -e data

src/coap_responder_sup.erl

@@ -26,8 +26,9 @@ get_responder(SupPid, Request) ->
 
 start_responder(SupPid, #coap_message{method=Method, options=Options}) ->
     Uri = proplists:get_value(uri_path, Options, []),
+    Query = proplists:get_value(uri_query, Options, []),
     supervisor:start_child(SupPid,
-        {{Method, Uri},
+        {{Method, Uri, Query},
             {coap_responder, start_link, [self(), Uri]},
             temporary, 5000, worker, []}).
 

src/coap_server_content.erl

@@ -7,7 +7,7 @@
 % Copyright (c) 2015 Petr Gotthard <petr.gotthard@centrum.cz>
 %
 
-% provides the .well-known/core resource and (in future) content queries
+% provides the .well-known/core resource and content queries
 -module(coap_server_content).
 -behaviour(coap_resource).
 
@@ -36,14 +36,40 @@ coap_unobserve(_State) -> ok.
 handle_info(_Message, State) -> {noreply, State}.
 coap_ack(_Ref, State) -> {ok, State}.
 
+% uri-query processing
+
 filter(Links, []) ->
     Links;
 filter(Links, [Search | Query]) ->
-    case binary:split(Search, <<$=>>) of
-        [Name, Value] ->
-            ok;
-        _Else -> ok
-    end,
-    filter(Links, Query).
+    filter(
+        case binary:split(Search, <<$=>>) of
+            [Name0, Value0] ->
+                Name = list_to_atom(binary_to_list(Name0)),
+                Value = wildcard_value(Value0),
+                lists:filter(
+                    fun (Link) -> match_link(Link, Name, Value) end,
+                    Links);
+            _Else ->
+                Links
+        end,
+        Query).
+
+wildcard_value(<<>>) ->
+    {global, <<>>};
+wildcard_value(Value) ->
+    case binary:last(Value) of
+        $* -> {prefix, binary:part(Value, 0, byte_size(Value)-1)};
+        _Else -> {global, Value}
+    end.
+
+match_link({_Type, _Uri, Attrs}, Name, Value0) ->
+    lists:any(
+        fun (AttrVal) ->
+            case Value0 of
+                {prefix, Value} -> binary:part(AttrVal, 0, byte_size(Value)) =:= Value;
+                {global, Value} -> AttrVal =:= Value
+            end
+        end,
+        proplists:get_all_values(Name, Attrs)).
 
 % end of file