Merge branch 'raimo/kernel/inet_ntoa_1-IPv6-lowercase/ERIERL-20/ERL-429/OTP-13006'

* raimo/kernel/inet_ntoa_1-IPv6-lowercase/ERIERL-20/ERL-429/OTP-13006:
  Accept IPv6 address %suffixes when parsing
  Adjust inet:ntoa/1 to RFC5952, but not deeper
  Update inet:ntoa according to modern RFCs

2 files changed, 191 insertions, 65 deletions

diff --git a/lib/kernel/src/inet_parse.erl b/lib/kernel/src/inet_parse.erl
index 0f5dc40553..29804dc50b 100644
--- a/lib/kernel/src/inet_parse.erl
+++ b/lib/kernel/src/inet_parse.erl
@@ -644,8 +644,12 @@ ipv6_addr(Cs) ->
     ipv6_addr(hex(Cs), [], 0).
 
 %% Before "::"
+ipv6_addr({Cs0,"%"++Cs1}, A, N) when N == 7 ->
+    ipv6_addr_scope(Cs1, [hex_to_int(Cs0)|A], [], N+1, []);
 ipv6_addr({Cs0,[]}, A, N) when N == 7 ->
     ipv6_addr_done([hex_to_int(Cs0)|A]);
+ipv6_addr({Cs0,"::%"++Cs1}, A, N) when N =< 6 ->
+    ipv6_addr_scope(Cs1, [hex_to_int(Cs0)|A], [], N+1, []);
 ipv6_addr({Cs0,"::"}, A, N) when N =< 6 ->
     ipv6_addr_done([hex_to_int(Cs0)|A], [], N+1);
 ipv6_addr({Cs0,"::"++Cs1}, A, N) when N =< 5 ->
@@ -658,6 +662,8 @@ ipv6_addr(_, _, _) ->
     erlang:error(badarg).
 
 %% After "::"
+ipv6_addr({Cs0,"%"++Cs1}, A, B, N) when N =< 6 ->
+    ipv6_addr_scope(Cs1, A, [hex_to_int(Cs0)|B], N+1, []);
 ipv6_addr({Cs0,[]}, A, B, N) when N =< 6 ->
     ipv6_addr_done(A, [hex_to_int(Cs0)|B], N+1);
 ipv6_addr({Cs0,":"++Cs1}, A, B, N) when N =< 5 ->
@@ -667,6 +673,43 @@ ipv6_addr({Cs0,"."++_=Cs1}, A, B, N) when N =< 5 ->
 ipv6_addr(_, _, _, _) ->
     erlang:error(badarg).
 
+%% After "%"
+ipv6_addr_scope([], Ar, Br, N, Sr) ->
+    ScopeId =
+        case lists:reverse(Sr) of
+            %% Empty scope id
+            "" -> 0;
+            %% Scope id starts with 0
+            "0"++S -> dec16(S);
+            _ -> 0
+        end,
+    %% Suggested formats for scope id parsing:
+    %%   "" -> "0"
+    %%   "0" -> Scope id 0
+    %%   "1" - "9", "10" - "99" -> "0"++S
+    %%   "0"++DecimalScopeId -> decimal scope id
+    %%   "25"++PercentEncoded -> Percent encoded interface name
+    %%   S -> Interface name (Unicode?)
+    %% Missing: translation from interface name into integer scope id.
+    %% XXX: scope id is actually 32 bit, but we only have room for
+    %% 16 bit in the second address word - ignore or fix (how)?
+    ipv6_addr_scope(ScopeId, Ar, Br, N);
+ipv6_addr_scope([C|Cs], Ar, Br, N, Sr) ->
+    ipv6_addr_scope(Cs, Ar, Br, N, [C|Sr]).
+%%
+ipv6_addr_scope(ScopeId, [P], Br, N)
+  when N =< 7, P =:= 16#fe80;
+       N =< 7, P =:= 16#ff02 ->
+    %% Optimized special case
+    ipv6_addr_done([ScopeId,P], Br, N+1);
+ipv6_addr_scope(ScopeId, Ar, Br, N) ->
+    case lists:reverse(Br++dup(8-N, 0, Ar)) of
+        [P,0|Xs] when P =:= 16#fe80; P =:= 16#ff02 ->
+            list_to_tuple([P,ScopeId|Xs]);
+        _ ->
+            erlang:error(badarg)
+    end.
+
 ipv6_addr_done(Ar, Br, N, {D1,D2,D3,D4}) ->
     ipv6_addr_done(Ar, [((D3 bsl 8) bor D4),((D1 bsl 8) bor D2)|Br], N+2).
 
@@ -690,6 +733,19 @@ hex(Cs, [_|_]=R, _) when is_list(Cs) ->
 hex(_, _, _) ->
     erlang:error(badarg).
 
+%% Parse a reverse decimal integer string, empty is 0
+dec16(Cs) -> dec16(Cs, 0).
+%%
+dec16([], I) -> I;
+dec16([C|Cs], I) when C >= $0, C =< $9 ->
+    case 10*I + (C - $0) of
+        J when 16#ffff < J ->
+            erlang:error(badarg);
+        J ->
+            dec16(Cs, J)
+    end;
+dec16(_, _) -> erlang:error(badarg).
+
 %% Hex string to integer
 hex_to_int(Cs) -> erlang:list_to_integer(Cs, 16).
 
@@ -703,7 +759,7 @@ dup(N, E, L) when is_integer(N), N >= 1 ->
 
 %% Convert IPv4 address to ascii
 %% Convert IPv6 / IPV4 address to ascii (plain format)
-ntoa({A,B,C,D}) ->
+ntoa({A,B,C,D}) when (A band B band C band D band (bnot 16#ff)) =:= 0 ->
     integer_to_list(A) ++ "." ++ integer_to_list(B) ++ "." ++ 
 	integer_to_list(C) ++ "." ++ integer_to_list(D);
 %% ANY
@@ -711,13 +767,25 @@ ntoa({0,0,0,0,0,0,0,0}) -> "::";
 %% LOOPBACK
 ntoa({0,0,0,0,0,0,0,1}) -> "::1";
 %% IPV4 ipv6 host address
-ntoa({0,0,0,0,0,0,A,B}) -> "::" ++ dig_to_dec(A) ++ "." ++ dig_to_dec(B);
+ntoa({0,0,0,0,0,0,A,B}) when (A band B band (bnot 16#ffff)) =:= 0 ->
+    "::" ++ dig_to_dec(A) ++ "." ++ dig_to_dec(B);
 %% IPV4 non ipv6 host address
-ntoa({0,0,0,0,0,16#ffff,A,B}) -> 
-    "::FFFF:" ++ dig_to_dec(A) ++ "." ++ dig_to_dec(B);
-ntoa({_,_,_,_,_,_,_,_}=T) ->
-    %% Find longest sequence of zeros, at least 2, to replace with "::"
-    ntoa(tuple_to_list(T), []);
+ntoa({0,0,0,0,0,16#ffff,A,B}) when (A band B band (bnot 16#ffff)) =:= 0 ->
+    "::ffff:" ++ dig_to_dec(A) ++ "." ++ dig_to_dec(B);
+ntoa({A,B,C,D,E,F,G,H})
+  when (A band B band C band D band E band F band G band H band
+            (bnot 16#ffff)) =:= 0 ->
+    if
+        A =:= 16#fe80, B =/= 0;
+        A =:= 16#ff02, B =/= 0 ->
+            %% Find longest sequence of zeros, at least 2,
+            %% to replace with "::"
+            ntoa([A,0,C,D,E,F,G,H], []) ++ "%0" ++ integer_to_list(B);
+        true ->
+            %% Find longest sequence of zeros, at least 2,
+            %% to replace with "::"
+            ntoa([A,B,C,D,E,F,G,H], [])
+    end;
 ntoa(_) ->
     {error, einval}.
 
@@ -780,9 +848,19 @@ dig_to_dec(X) ->
     integer_to_list((X bsr 8) band 16#ff) ++ "." ++
 	integer_to_list(X band 16#ff).
 
-%% Convert a integer to hex string
-dig_to_hex(X) ->
-    erlang:integer_to_list(X, 16).
+%% Convert a integer to hex string (lowercase)
+dig_to_hex(0) -> "0";
+dig_to_hex(X) when is_integer(X), 0 < X ->
+    dig_to_hex(X, "").
+%%
+dig_to_hex(0, Acc) -> Acc;
+dig_to_hex(X, Acc) ->
+    dig_to_hex(
+      X bsr 4,
+      [case X band 15 of
+           D when D < 10 -> D + $0;
+           D -> D - 10 + $a
+       end|Acc]).
 
 %%
 %% Count number of '.' in a name
diff --git a/lib/kernel/test/inet_SUITE.erl b/lib/kernel/test/inet_SUITE.erl
index 97f789b61c..3b502be8b8 100644
--- a/lib/kernel/test/inet_SUITE.erl
+++ b/lib/kernel/test/inet_SUITE.erl
@@ -447,91 +447,125 @@ parse_hosts(Config) when is_list(Config) ->
     inet_parse:resolv(ResolvErr1).
 
 parse_address(Config) when is_list(Config) ->
-    V4Strict =
+    V4Reversable =
 	[{{0,0,0,0},"0.0.0.0"},
-	 {{1,2,3,4},"1.2.3.4"},
+         {{1,2,3,4},"1.2.3.4"},
 	 {{253,252,251,250},"253.252.251.250"},
 	 {{1,2,255,254},"1.2.255.254"}],
-    V6Strict =
+    V6Reversable =
 	[{{0,0,0,0,0,0,0,0},"::"},
+	 {{0,0,0,0,0,0,0,1},"::1"},
+	 {{0,0,0,0,0,0,0,2},"::0.0.0.2"},
 	 {{15,0,0,0,0,0,0,2},"f::2"},
-	 {{15,16#f11,0,0,0,0,256,2},"f:f11::0100:2"},
-	 {{0,0,0,0,0,0,0,16#17},"::17"},
-	 {{16#700,0,0,0,0,0,0,0},"0700::"},
-	 {{0,0,0,0,0,0,2,1},"::2:1"},
+	 {{15,16#f11,0,0,0,0,256,2},"f:f11::100:2"},
+	 {{16#700,0,0,0,0,0,0,0},"700::"},
+	 {{0,0,0,0,0,0,2,1},"::0.2.0.1"},
 	 {{0,0,0,0,0,3,2,1},"::3:2:1"},
 	 {{0,0,0,0,4,3,2,1},"::4:3:2:1"},
 	 {{0,0,0,5,4,3,2,1},"::5:4:3:2:1"},
 	 {{0,0,6,5,4,3,2,1},"::6:5:4:3:2:1"},
-	 {{0,7,6,5,4,3,2,1},"::7:6:5:4:3:2:1"},
+	 {{0,7,6,5,4,3,2,1},"0:7:6:5:4:3:2:1"},
 	 {{7,0,0,0,0,0,0,0},"7::"},
 	 {{7,6,0,0,0,0,0,0},"7:6::"},
 	 {{7,6,5,0,0,0,0,0},"7:6:5::"},
 	 {{7,6,5,4,0,0,0,0},"7:6:5:4::"},
 	 {{7,6,5,4,3,0,0,0},"7:6:5:4:3::"},
 	 {{7,6,5,4,3,2,0,0},"7:6:5:4:3:2::"},
-	 {{7,6,5,4,3,2,1,0},"7:6:5:4:3:2:1::"},
+	 {{7,6,5,4,3,2,1,0},"7:6:5:4:3:2:1:0"},
+	 {{0,0,6,5,4,3,0,0},"::6:5:4:3:0:0"},
+	 {{0,0,6,5,4,0,0,0},"0:0:6:5:4::"},
+	 {{8,0,0,5,4,0,0,1},"8::5:4:0:0:1"},
+	 {{8,0,0,5,0,0,0,1},"8:0:0:5::1"},
+	 {{0,7,6,5,4,3,2,0},"0:7:6:5:4:3:2:0"},
+	 {{0,0,6,5,4,3,0,0},"::6:5:4:3:0:0"},
+	 {{0,0,0,5,4,0,0,0},"::5:4:0:0:0"},
+	 {{0,0,0,0,4,0,0,0},"::4:0:0:0"},
+	 {{0,0,0,5,0,0,0,0},"0:0:0:5::"},
 	 {{16#c11,16#c22,16#5c33,16#c440,16#55c0,16#c66c,16#77,16#88},
-	  "c11:0c22:5c33:c440:55c0:c66c:77:0088"},
+	  "c11:c22:5c33:c440:55c0:c66c:77:88"},
+	 {{0,16#c22,16#5c33,16#c440,16#55c0,16#c66c,16#77,16#88},
+	  "0:c22:5c33:c440:55c0:c66c:77:88"},
 	 {{16#c11,0,16#5c33,16#c440,16#55c0,16#c66c,16#77,16#88},
-	  "c11::5c33:c440:55c0:c66c:77:0088"},
+	  "c11:0:5c33:c440:55c0:c66c:77:88"},
 	 {{16#c11,16#c22,0,16#c440,16#55c0,16#c66c,16#77,16#88},
-	  "c11:0c22::c440:55c0:c66c:77:0088"},
+	  "c11:c22:0:c440:55c0:c66c:77:88"},
 	 {{16#c11,16#c22,16#5c33,0,16#55c0,16#c66c,16#77,16#88},
-	  "c11:0c22:5c33::55c0:c66c:77:0088"},
+	  "c11:c22:5c33:0:55c0:c66c:77:88"},
 	 {{16#c11,16#c22,16#5c33,16#c440,0,16#c66c,16#77,16#88},
-	  "c11:0c22:5c33:c440::c66c:77:0088"},
+	  "c11:c22:5c33:c440:0:c66c:77:88"},
 	 {{16#c11,16#c22,16#5c33,16#c440,16#55c0,0,16#77,16#88},
-	  "c11:0c22:5c33:c440:55c0::77:0088"},
+	  "c11:c22:5c33:c440:55c0:0:77:88"},
 	 {{16#c11,16#c22,16#5c33,16#c440,16#55c0,16#c66c,0,16#88},
-	  "c11:0c22:5c33:c440:55c0:c66c::0088"},
+	  "c11:c22:5c33:c440:55c0:c66c:0:88"},
+	 {{16#c11,16#c22,16#5c33,16#c440,16#55c0,16#c66c,16#77,0},
+	  "c11:c22:5c33:c440:55c0:c66c:77:0"},
+	 {{0,0,16#5c33,16#c440,16#55c0,16#c66c,16#77,16#88},
+	  "::5c33:c440:55c0:c66c:77:88"},
 	 {{16#c11,0,0,16#c440,16#55c0,16#c66c,16#77,16#88},
-	  "c11::c440:55c0:c66c:77:0088"},
+	  "c11::c440:55c0:c66c:77:88"},
 	 {{16#c11,16#c22,0,0,16#55c0,16#c66c,16#77,16#88},
-	  "c11:0c22::55c0:c66c:77:0088"},
+	  "c11:c22::55c0:c66c:77:88"},
 	 {{16#c11,16#c22,16#5c33,0,0,16#c66c,16#77,16#88},
-	  "c11:0c22:5c33::c66c:77:0088"},
+	  "c11:c22:5c33::c66c:77:88"},
 	 {{16#c11,16#c22,16#5c33,16#c440,0,0,16#77,16#88},
-	  "c11:0c22:5c33:c440::77:0088"},
+	  "c11:c22:5c33:c440::77:88"},
 	 {{16#c11,16#c22,16#5c33,16#c440,16#55c0,0,0,16#88},
-	  "c11:0c22:5c33:c440:55c0::0088"},
+	  "c11:c22:5c33:c440:55c0::88"},
+	 {{16#c11,16#c22,16#5c33,16#c440,16#55c0,16#c66c,0,0},
+	  "c11:c22:5c33:c440:55c0:c66c::"},
+	 {{0,0,0,16#c440,16#55c0,16#c66c,16#77,16#88},
+	  "::c440:55c0:c66c:77:88"},
 	 {{16#c11,0,0,0,16#55c0,16#c66c,16#77,16#88},
-	  "c11::55c0:c66c:77:0088"},
+	  "c11::55c0:c66c:77:88"},
 	 {{16#c11,16#c22,0,0,0,16#c66c,16#77,16#88},
-	  "c11:0c22::c66c:77:0088"},
+	  "c11:c22::c66c:77:88"},
 	 {{16#c11,16#c22,16#5c33,0,0,0,16#77,16#88},
-	  "c11:0c22:5c33::77:0088"},
+	  "c11:c22:5c33::77:88"},
 	 {{16#c11,16#c22,16#5c33,16#c440,0,0,0,16#88},
-	  "c11:0c22:5c33:c440::0088"},
+	  "c11:c22:5c33:c440::88"},
+	 {{16#c11,16#c22,16#5c33,16#c440,16#55c0,0,0,0},
+	  "c11:c22:5c33:c440:55c0::"},
+	 {{0,0,0,0,16#55c0,16#c66c,16#77,16#88},
+	  "::55c0:c66c:77:88"},
 	 {{16#c11,0,0,0,0,16#c66c,16#77,16#88},
-	  "c11::c66c:77:0088"},
+	  "c11::c66c:77:88"},
 	 {{16#c11,16#c22,0,0,0,0,16#77,16#88},
-	  "c11:0c22::77:0088"},
+	  "c11:c22::77:88"},
 	 {{16#c11,16#c22,16#5c33,0,0,0,0,16#88},
-	  "c11:0c22:5c33::0088"},
+	  "c11:c22:5c33::88"},
+	 {{16#c11,16#c22,16#5c33,16#c440,0,0,0,0},
+	  "c11:c22:5c33:c440::"},
+	 {{0,0,0,0,0,16#c66c,16#77,16#88},
+	  "::c66c:77:88"},
 	 {{16#c11,0,0,0,0,0,16#77,16#88},
-	  "c11::77:0088"},
+	  "c11::77:88"},
 	 {{16#c11,16#c22,0,0,0,0,0,16#88},
-	  "c11:0c22::0088"},
-	 {{0,0,0,0,0,65535,258,65534},"::FFFF:1.2.255.254"},
+	  "c11:c22::88"},
+	 {{16#c11,16#c22,16#5c33,0,0,0,0,0},
+	  "c11:c22:5c33::"},
+	 {{0,0,0,0,0,65535,258,65534},"::ffff:1.2.255.254"},
+         {{16#fe80,12345,0,0,0,0,0,16#12},"fe80::12%012345"},
 	 {{16#ffff,16#ffff,16#ffff,16#ffff,16#ffff,16#ffff,16#ffff,16#ffff},
 	  "ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff"}
-	 |[{{D2,0,0,0,0,P,(D1 bsl 8) bor D2,(D3 bsl 8) bor D4},
-	    erlang:integer_to_list(D2, 16)++"::"++Q++S}
-	   || {{D1,D2,D3,D4},S} <- V4Strict,
-	      {P,Q} <- [{0,""},{16#17,"17:"},{16#ff0,"0ff0:"}]]],
+         |[{list_to_tuple(P++[(D1 bsl 8) bor D2,(D3 bsl 8) bor D4]),
+            Q++S}
+           || {{D1,D2,D3,D4},S} <-
+                  tl(V4Reversable),
+              {P,Q} <-
+                  [{[0,0,0,0,0,16#ffff],"::ffff:"},
+                   {[0,0,0,0,0,0],"::"}]]],
     V4Sloppy =
 	[{{10,1,16#98,16#76},"10.0x019876"},
 	 {{8#12,1,8#130,8#321},"012.01.054321"},
-	 {{255,255,255,255},"255.255.255.0377"},
-	 {{255,255,255,255},"0Xff.000000000377.0x0000ff.255"},
-	 {{255,255,255,255},"255.255.65535"},
-	 {{255,255,255,255},"255.0xFF.0177777"},
-	 {{255,255,255,255},"255.16777215"},
-	 {{255,255,255,255},"00377.0XFFFFFF"},
-	 {{255,255,255,255},"4294967295"},
-	 {{255,255,255,255},"0xffffffff"},
-	 {{255,255,255,255},"00000000000037777777777"},
+	 {{252,253,254,255},"252.253.254.0377"},
+	 {{252,253,254,255},"0Xfc.000000000375.0x0000fe.255"},
+	 {{252,253,254,255},"252.253.65279"},
+	 {{252,253,254,255},"252.0xFD.0177377"},
+	 {{252,253,254,255},"252.16645887"},
+	 {{252,253,254,255},"00374.0XFDFEFF"},
+	 {{252,253,254,255},"4244504319"},
+	 {{252,253,254,255},"0xfcfdfeff"},
+	 {{252,253,254,255},"00000000000037477377377"},
 	 {{16#12,16#34,16#56,16#78},"0x12345678"},
 	 {{16#12,16#34,16#56,16#78},"0x12.0x345678"},
 	 {{16#12,16#34,16#56,16#78},"0x12.0X34.0x5678"},
@@ -543,8 +577,14 @@ parse_address(Config) when is_list(Config) ->
 	 {{0,0,0,0},"0.00.0.0"},
 	 {{0,0,0,0},"0.0.000000000000.0"}],
     V6Sloppy =
-	[{{0,0,0,0,0,65535,(D1 bsl 8) bor D2,(D3 bsl 8) bor D4},S}
-	 || {{D1,D2,D3,D4},S} <- V4Strict++V4Sloppy],
+        [{{16#a,16#b,16#c,16#0,16#0,16#d,16#e,16#f},"A:B:C::d:e:f"},
+         {{16#fe80,0,0,0,0,0,0,16#12},"fe80::12%XXXXXXX"}]
+        ++
+        [{{P,0,0,0,0,D2,(D1 bsl 8) bor D2,(D3 bsl 8) bor D4},
+          Q++erlang:integer_to_list(D2, 16)++":"++S}
+         || {{D1,D2,D3,D4},S} <- V4Reversable,
+            {P,Q} <-
+                [{16#2001,"2001::"},{16#177,"177::"},{16#ff0,"Ff0::"}]],
     V4Err =
 	["0.256.0.1",
 	 "1.2.3.4.5",
@@ -588,28 +628,36 @@ parse_address(Config) when is_list(Config) ->
 	 "fec0::fFfF:127.0.0.1."],
     t_parse_address
       (parse_ipv6_address,
-       V6Strict++V6Sloppy++V6Err++V4Err),
+       false,
+       V6Reversable++V6Sloppy++V6Err++V4Err),
     t_parse_address
       (parse_ipv6strict_address,
-       V6Strict++V6Err++V4Err++[S || {_,S} <- V6Sloppy]),
+       true,
+       V6Reversable++V6Err++V4Err),
     t_parse_address
       (parse_ipv4_address,
-       V4Strict++V4Sloppy++V4Err++V6Err++[S || {_,S} <- V6Strict]),
+       false,
+       V4Reversable++V4Sloppy++V4Err++V6Err++[S || {_,S} <- V6Reversable]),
     t_parse_address
       (parse_ipv4strict_address,
-       V4Strict++V4Err++V6Err++[S || {_,S} <- V4Sloppy++V6Strict]).
+       true,
+       V4Reversable++V4Err++V6Err++[S || {_,S} <- V4Sloppy++V6Reversable]).
 
-t_parse_address(Func, []) ->
+t_parse_address(Func, _Reversable, []) ->
     io:format("~p done.~n", [Func]),
     ok;
-t_parse_address(Func, [{Addr,String}|L]) ->
+t_parse_address(Func, Reversable, [{Addr,String}|L]) ->
     io:format("~p = ~p.~n", [Addr,String]),
     {ok,Addr} = inet:Func(String),
-    t_parse_address(Func, L);
-t_parse_address(Func, [String|L]) ->
+    case Reversable of
+        true ->String = inet:ntoa(Addr);
+        false -> ok
+    end,
+    t_parse_address(Func, Reversable, L);
+t_parse_address(Func, Reversable, [String|L]) ->
     io:format("~p.~n", [String]),
     {error,einval} = inet:Func(String),
-    t_parse_address(Func, L).
+    t_parse_address(Func, Reversable, L).
 
 parse_strict_address(Config) when is_list(Config) ->
     {ok, {127,0,0,1}} =