Merge branch 'raimo/receive-TOS-TCLASS/ERIERL-187/OTP-15145' into maint

* raimo/receive-TOS-TCLASS/ERIERL-187/OTP-15145:
  Elaborate the disclaimer for 'pktoptions'
  Improve platform filter
  Fix endianness bug for CMSG parsing

3 files changed, 48 insertions, 12 deletions

diff --git a/lib/kernel/doc/src/gen_tcp.xml b/lib/kernel/doc/src/gen_tcp.xml
index cf649991d0..24d63693fd 100644
--- a/lib/kernel/doc/src/gen_tcp.xml
+++ b/lib/kernel/doc/src/gen_tcp.xml
@@ -74,13 +74,25 @@ do_recv(Sock, Bs) ->
       <desc>
 	<p>
 	  If the platform implements the IPv4 option
-	  <c>IP_PKTOPTIONS</c> (probably Linux specific), or the IPv6 option
+	  <c>IP_PKTOPTIONS</c>, or the IPv6 option
 	  <c>IPV6_PKTOPTIONS</c> or <c>IPV6_2292PKTOPTIONS</c> for the socket
 	  this value is returned from
 	  <seealso marker="inet#getopts/2"><c>inet:getopts/2</c></seealso>
 	  when called with the option name
 	  <seealso marker="#type-option_name"><c>pktoptions</c></seealso>.
 	</p>
+	<note>
+	  <p>
+	    This option appears to be VERY Linux specific,
+	    and its existence in future Linux kernel versions
+	    is also worrying since the option is part of RFC 2292
+	    which is since long (2003) obsoleted by RFC 3542
+	    that <em>explicitly</em> removes this possibility to get
+	    packet information from a stream socket.
+	    For comparision: it has existed in FreeBSD but is now removed,
+	    at least since FreeBSD 10.
+	  </p>
+	</note>
       </desc>
     </datatype>
     <datatype>
diff --git a/lib/kernel/test/gen_tcp_misc_SUITE.erl b/lib/kernel/test/gen_tcp_misc_SUITE.erl
index d532537eb9..358ca872f7 100644
--- a/lib/kernel/test/gen_tcp_misc_SUITE.erl
+++ b/lib/kernel/test/gen_tcp_misc_SUITE.erl
@@ -1919,7 +1919,17 @@ so_priority(Config) when is_list(Config) ->
 
 
 %% IP_RECVTOS and IP_RECVTCLASS for IP_PKTOPTIONS
-%% does not seem to be implemented in Linux until kernel 3.0
+%% does not seem to be implemented in Linux until kernel 3.1
+%%
+%% It seems pktoptions does not return valid values
+%% for IPv4 connect sockets.  On the accept socket
+%% we get valid values, but on the connect socket we get
+%% the default values for TOS and TTL.
+%%
+%% Therefore the argument CheckConnect that enables
+%% checking the returned values for the connect socket.
+%% It is only used for recvtclass that is an IPv6 option
+%% and there we get valid values from both socket ends.
 
 recvtos(_Config) ->
     test_pktoptions(
@@ -1965,25 +1975,38 @@ recvtclass(_Config) ->
 %% when machines with newer versions gets installed...
 %% If the test still fails for a plausible reason these
 %% version numbers simply should be increased.
+%% Or maybe we should change to only test on known good
+%% platforms - change {unix,_} to false?
 
-%% Using the option returns einval, so it is not implemented.
+%% pktoptions is not supported for IPv4
+recvtos_ok({unix,openbsd}, OSVer) -> not semver_lt(OSVer, {6,4,0});
 recvtos_ok({unix,darwin}, OSVer) -> not semver_lt(OSVer, {17,6,0});
+recvtos_ok({unix,freebsd}, OSVer) -> not semver_lt(OSVer, {11,2,0});
+%% Using the option returns einval, so it is not implemented.
+recvtos_ok({unix,sunos}, OSVer) -> not semver_lt(OSVer, {5,12,0});
 %% Does not return any value - not implemented for pktoptions
 recvtos_ok({unix,linux}, OSVer) -> not semver_lt(OSVer, {3,1,0});
 %%
 recvtos_ok({unix,_}, _) -> true;
 recvtos_ok(_, _) -> false.
 
+%% pktoptions is not supported for IPv4
+recvttl_ok({unix,openbsd}, OSVer) -> not semver_lt(OSVer, {6,4,0});
+recvttl_ok({unix,darwin}, OSVer) -> not semver_lt(OSVer, {17,6,0});
+recvttl_ok({unix,freebsd}, OSVer) -> not semver_lt(OSVer, {11,2,0});
+%% Using the option returns einval, so it is not implemented.
+recvttl_ok({unix,sunos}, OSVer) -> not semver_lt(OSVer, {5,12,0});
+%%
 recvttl_ok({unix,linux}, _) -> true;
 recvttl_ok({unix,_}, _) -> true;
 recvttl_ok(_, _) -> false.
 
-%% Using the option returns einval, so it is not implemented.
+%% pktoptions is not supported for IPv6
 recvtclass_ok({unix,openbsd}, OSVer) -> not semver_lt(OSVer, {6,4,0});
-recvtclass_ok({unix,freebsd}, OSVer) -> not semver_lt(OSVer, {11,2,0});
-%% Using the option returns einval up to 0.9.0, so it is not implemented.
-%% Does not return any value - not implemented for pktoptions
 recvtclass_ok({unix,darwin}, OSVer) -> not semver_lt(OSVer, {17,6,0});
+recvtclass_ok({unix,sunos}, OSVer) -> not semver_lt(OSVer, {5,12,0});
+%% Using the option returns einval, so it is not implemented.
+recvtclass_ok({unix,freebsd}, OSVer) -> not semver_lt(OSVer, {11,2,0});
 %% Does not return any value - not implemented for pktoptions
 recvtclass_ok({unix,linux}, OSVer) -> not semver_lt(OSVer, {3,1,0});
 %%
@@ -2002,18 +2025,18 @@ semver_lt({X1,Y1,Z1}, {X2,Y2,Z2}) ->
     end;
 semver_lt(_, {_,_,_}) -> false.
 
-test_pktoptions(Family, Spec, OSFilter, CheckAccept) ->
+test_pktoptions(Family, Spec, OSFilter, CheckConnect) ->
     OSType = os:type(),
     OSVer = os:version(),
     case OSFilter(OSType, OSVer) of
         true ->
             io:format("Os: ~p, ~p~n", [OSType,OSVer]),
-            test_pktoptions(Family, Spec, CheckAccept, OSType, OSVer);
+            test_pktoptions(Family, Spec, CheckConnect, OSType, OSVer);
         false ->
             {skip,{not_supported_for_os_version,{OSType,OSVer}}}
     end.
 %%
-test_pktoptions(Family, Spec, CheckAccept, OSType, OSVer) ->
+test_pktoptions(Family, Spec, CheckConnect, OSType, OSVer) ->
     Timeout = 5000,
     RecvOpts = [RecvOpt || {RecvOpt,_,_} <- Spec],
     TrueRecvOpts = [{RecvOpt,true} || {RecvOpt,_,_} <- Spec],
@@ -2105,7 +2128,7 @@ test_pktoptions(Family, Spec, CheckAccept, OSType, OSVer) ->
     ok = gen_tcp:close(S4),
     ok = gen_tcp:close(S3),
     ok = gen_tcp:close(L),
-    (Result1 and ((not CheckAccept) or (Result2 and Result3)))
+    (Result1 and ((not CheckConnect) or (Result2 and Result3)))
         orelse
         exit({failed,
               [{OptsVals1,OptsVals4,OptsVals},
diff --git a/lib/kernel/test/gen_udp_SUITE.erl b/lib/kernel/test/gen_udp_SUITE.erl
index 878e48786c..af9985de45 100644
--- a/lib/kernel/test/gen_udp_SUITE.erl
+++ b/lib/kernel/test/gen_udp_SUITE.erl
@@ -616,13 +616,14 @@ recvtclass(_Config) ->
 %% when machines with newer versions gets installed...
 %% If the test still fails for a plausible reason these
 %% version numbers simply should be increased.
+%% Or maybe we should change to only test on known good platforms?
 
 %% Using the option returns einval, so it is not implemented.
 recvtos_ok({unix,darwin}, OSVer) -> not semver_lt(OSVer, {17,6,0});
 %% Using the option returns einval, so it is not implemented.
 recvtos_ok({unix,openbsd}, OSVer) -> not semver_lt(OSVer, {6,4,0});
 %% Using the option returns einval, so it is not implemented.
-recvtos_ok({unix,sunos}, OSVer) -> not semver_lt(OSVer, {5,11,0});
+recvtos_ok({unix,sunos}, OSVer) -> not semver_lt(OSVer, {5,12,0});
 %%
 recvtos_ok({unix,_}, _) -> true;
 recvtos_ok(_, _) -> false.