802.1x EAPoL PDU header support

[kruegger]

Hi

I have added the 802.1x EAPoL PDU header support. Please, review and let me know.

[msantos]

@kruegger this looks great! thanks so much! Sorry about the delay, just catching up after vacation. The test is failing for me:

$ rebar3 do clean, compile, eunit
===> Cleaning out pkt...
===> Verifying dependencies...
===> Compiling pkt
===> Verifying dependencies...
===> Compiling pkt
===> Performing EUnit tests...
......................
Pending:
  undefined
    %% Unknown error: {abort,
                   {generator_failed,
                       {{pkt_802_1x_tests,codec_test_,0},
                        {error,function_clause,
                            [{pkt_ether,type,
                                 [34958],
                                 [{file,
                                      "/home/msantos/src/erlang/pkt/_build/test/lib/pkt/src/pkt_ether.erl"},
                                  {line,37}]},
                             {pkt,decapsulate_next,2,
                                 [{file,
                                      "/home/msantos/src/erlang/pkt/_build/test/lib/pkt/src/pkt.erl"},
                                  {line,122}]},
                             {pkt_802_1x_tests,decode,0,
                                 [{file,
                                      "/home/msantos/src/erlang/pkt/_build/test/lib/pkt/test/pkt_802_1x_tests.erl"},
                                  {line,21}]},
                             {pkt_802_1x_tests,codec_test_,0,
                                 [{file,
                                      "/home/msantos/src/erlang/pkt/_build/test/lib/pkt/test/pkt_802_1x_tests.erl"},
                                  {line,8}]}]}}}}

Finished in ? seconds
25 tests, 0 failures, 3 cancelled
===> Error running tests

Seems like some boilerplate just needs to be added to pkt.erl. There is also a LLC header in the test packet that needs to be accounted for.

diff --git a/src/pkt.erl b/src/pkt.erl
index abc1921..d9239f8 100644
--- a/src/pkt.erl
+++ b/src/pkt.erl
@@ -43,6 +43,7 @@
         ether_type/1,
         mpls/1,
         '802.1q'/1,
+        '802.1x'/1,
         llc/1,
         arp/1,
         rarp/1,
@@ -129,6 +130,9 @@ decapsulate_next({'802.1q', Data}, Headers) ->
 decapsulate_next({'802.1qinq', Data}, Headers) ->
     {Header, Payload} = '802.1q'(Data),
     decapsulate_next({next(Header), Payload}, [Header|Headers]);
+decapsulate_next({'802.1x', Data}, Headers) ->
+    {Header, Payload} = '802.1x'(Data),
+    decapsulate_next({next(Header), Payload}, [Header|Headers]);
 decapsulate_next({llc, Data}, Headers) ->
     {Header, Payload} = llc(Data),
     lists:reverse([Payload, Header|Headers]);
@@ -244,6 +248,7 @@ decode_next({Proto, Data}, Headers) when
     Proto =:= linux_cooked;
     Proto =:= null;
     Proto =:= '802.1q';
+    Proto =:= '802.1x';

     Proto =:= ipv6_ah;
     Proto =:= ipv6_dstopts;
@@ -282,6 +287,7 @@ decode_next({ipv6_none, Data}, Headers) ->
 decode_next({Proto, Data}, Headers) when
     Proto =:= arp;
     Proto =:= rarp;
+    Proto =:= llc;
     Proto =:= lldp;
     Proto =:= icmp;
     Proto =:= icmp6;
@@ -302,6 +308,7 @@ next(#null{family = Family}) -> family(Family);
 next(#linux_cooked{pro = Pro}) -> ether_type(Pro);
 next(#ether{type = Type}) -> ether_type(Type);
 next(#'802.1q'{type = Type}) -> ether_type(Type);
+next(#'802.1x'{type = Type}) -> ether_type(Type);
 next(#ipv4{p = P}) -> ipproto(P);
 next(#gre{type = Type}) -> ether_type(Type);
 next(#ipv6{next = Next}) -> ipproto(Next);
@@ -349,6 +356,9 @@ llc(N) ->
 '802.1q'(N) ->
     pkt_802_1q:codec(N).

+'802.1x'(N) ->
+    pkt_802_1x:codec(N).
+
 %% IPv4
 ipv4(N) ->
     pkt_ipv4:codec(N).
diff --git a/src/pkt_ether.erl b/src/pkt_ether.erl
index 77ea6e3..fd8c7a4 100644
--- a/src/pkt_ether.erl
+++ b/src/pkt_ether.erl
@@ -45,6 +45,8 @@ type(EtherType) when EtherType < 16#05DC -> llc;
 type(?ETH_P_802_1Q) -> '802.1q';
 %% 802.1ad (802.1q QinQ)
 type(?ETH_P_802_1QinQ) -> '802.1qinq';
+%% 802.1X
+type(?ETH_P_802_1X) -> '802.1x';
 %% MPLS_
 type(?ETH_P_MPLS_UNI) -> mpls;
 type(?ETH_P_MPLS_MULTI) -> mpls.
diff --git a/test/pkt_802_1x_tests.erl b/test/pkt_802_1x_tests.erl
index 9a293d9..c36bdb5 100644
--- a/test/pkt_802_1x_tests.erl
+++ b/test/pkt_802_1x_tests.erl
@@ -18,7 +18,7 @@ packet() ->
       202,98,8,201,119,185,73,11,98,90,123,40,181,73,189,189,89,19,137>>.

 decode() ->
-    [_Ether, EAPoL, _Payload] = pkt:decapsulate(packet()),
+    [_Ether, EAPoL, _LLC, _Payload] = pkt:decapsulate(packet()),
     ?_assertEqual(
        {'802.1x',2, 3, 127 },
        EAPoL

[kruegger]

@msantos Thanks for the comment and my apology for missing merge code which I thought I checked in last year.

On your comment on LLC handling and following code: @@ -302,6 +308,7 @@ next(#null{family = Family}) -> family(Family); next(#linux_cooked{pro = Pro}) -> ether_type(Pro); next(#ether{type = Type}) -> ether_type(Type); next(#'802.1q'{type = Type}) -> ether_type(Type); +next(#'802.1x'{type = Type}) -> ether_type(Type); next(#ipv4{p = P}) -> ipproto(P); next(#gre{type = Type}) -> ether_type(Type); next(#ipv6{next = Next}) -> ipproto(Next);

IMHO, I think, we shouldn't do this since the payload contains the message that requires additional decoders of various applications. The test PDU happens to be EAPoL-Key(type 16#0003) message which needs decoder. It is not cascaded other type of Layer 2 message.

What do you think?

[msantos]

Agreed, my mistake, thanks for the clarification. Merged, thank you!