File 1769-inet_dns-support-UPDATE.patch of Package erlang

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File 1769-inet_dns-support-UPDATE.patch of Package erlang (Revision 2f15b05a39d64e5cba90e927e8665465)

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From 89f6c65a4af3a21da0ecf268b0982b6fe158873b Mon Sep 17 00:00:00 2001
From: Alexander Clouter <alex@digriz.org.uk>
Date: Thu, 20 Apr 2023 08:22:11 +0100
Subject: [PATCH 09/10] inet_dns: support UPDATE

---
 lib/kernel/src/inet_dns.erl                   | 79 +++++++++++--------
 lib/kernel/src/inet_dns.hrl                   | 13 ++-
 lib/kernel/src/inet_res.erl                   |  5 ++
 lib/kernel/test/inet_res_SUITE.erl            | 62 ++++++++++++++-
 .../inet_res_SUITE_data/otptest/knot_inc.conf |  6 ++
 5 files changed, 129 insertions(+), 36 deletions(-)

diff --git a/lib/kernel/src/inet_dns.erl b/lib/kernel/src/inet_dns.erl
index fc38e437aa..6228ca9790 100644
--- a/lib/kernel/src/inet_dns.erl
+++ b/lib/kernel/src/inet_dns.erl
@@ -24,6 +24,7 @@
 %% RFC 1035: Domain Names - Implementation and Specification
 %% RFC 1995: Incremental Zone Transfer in DNS
 %% RFC 1996: A Mechanism for Prompt Notification of Zone Changes (DNS NOTIFY)
+%% RFC 2136: Dynamic Updates in the Domain Name System (DNS UPDATE)
 %% RFC 2181: Clarifications to the DNS Specification
 %% RFC 2782: A DNS RR for specifying the location of services (DNS SRV)
 %% RFC 2915: The Naming Authority Pointer (NAPTR) DNS Resource Rec
@@ -160,9 +161,9 @@ do_decode(<<Id:16,
 	   QdCount:16,AnCount:16,NsCount:16,ArCount:16,
 	   QdBuf/binary>>=Buffer) ->
     {AnBuf,QdList,QdTC} = decode_query_section(QdBuf,QdCount,Buffer),
-    {NsBuf,AnList,AnTC} = decode_rr_section(AnBuf,AnCount,Buffer),
-    {ArBuf,NsList,NsTC} = decode_rr_section(NsBuf,NsCount,Buffer),
-    {Rest,ArList,ArTC} = decode_rr_section(ArBuf,ArCount,Buffer),
+    {NsBuf,AnList,AnTC} = decode_rr_section(Opcode,AnBuf,AnCount,Buffer),
+    {ArBuf,NsList,NsTC} = decode_rr_section(Opcode,NsBuf,NsCount,Buffer),
+    {Rest,ArList,ArTC} = decode_rr_section(Opcode,ArBuf,ArCount,Buffer),
     ?MATCH_ELSE_DECODE_ERROR(
        Rest,
        <<>>,
@@ -220,14 +221,14 @@ decode_query_section(Bin, N, Buffer, Qs) ->
            decode_query_section(Rest, N-1, Buffer, [DnsQuery|Qs])
        end).
 
-decode_rr_section(Bin, N, Buffer) ->
-    decode_rr_section(Bin, N, Buffer, []).
+decode_rr_section(Opcode, Bin, N, Buffer) ->
+    decode_rr_section(Opcode, Bin, N, Buffer, []).
 
-decode_rr_section(<<>>=Rest, N, _Buffer, RRs) ->
+decode_rr_section(_Opcode, <<>>=Rest, N, _Buffer, RRs) ->
     {Rest,reverse(RRs),N =/= 0};
-decode_rr_section(Rest, 0, _Buffer, RRs) ->
+decode_rr_section(_Opcode, Rest, 0, _Buffer, RRs) ->
     {Rest,reverse(RRs),false};
-decode_rr_section(Bin, N, Buffer, RRs) ->
+decode_rr_section(Opcode, Bin, N, Buffer, RRs) ->
     ?MATCH_ELSE_DECODE_ERROR(
        decode_name(Bin, Buffer),
        {<<T:16/unsigned,C:16/unsigned,TTL:4/binary,
@@ -254,7 +255,13 @@ decode_rr_section(Bin, N, Buffer, RRs) ->
                           do               = DnssecOk};
                    _ ->
                        {Class,CacheFlush} = decode_class(C),
-                       Data = decode_data(D, Class, Type, Buffer),
+                       Data = if
+                           %% RFC 2136: 2.4. Allow length zero data for UPDATE
+                           Opcode == ?UPDATE, D == <<>> ->
+                               #dns_rr{}#dns_rr.data;
+                           true ->
+                               decode_data(D, Class, Type, Buffer)
+                       end,
                        <<TimeToLive:32/signed>> = TTL,
                        #dns_rr{
                           domain = Name,
@@ -264,7 +271,7 @@ decode_rr_section(Bin, N, Buffer, RRs) ->
                           data   = Data,
                           func   = CacheFlush}
                end,
-           decode_rr_section(Rest, N-1, Buffer, [RR|RRs])
+           decode_rr_section(Opcode, Rest, N-1, Buffer, [RR|RRs])
        end).
 
 %%
@@ -276,12 +283,13 @@ encode(Q) ->
     AnCount = length(Q#dns_rec.anlist),
     NsCount = length(Q#dns_rec.nslist),
     ArCount = length(Q#dns_rec.arlist),
+    OC = Q#dns_rec.header#dns_header.opcode,
     B0 = encode_header(Q#dns_rec.header, QdCount, AnCount, NsCount, ArCount),
     C0 = gb_trees:empty(),
     {B1,C1} = encode_query_section(B0, C0, Q#dns_rec.qdlist),
-    {B2,C2} = encode_res_section(B1, C1, Q#dns_rec.anlist),
-    {B3,C3} = encode_res_section(B2, C2, Q#dns_rec.nslist),
-    {B,_} = encode_res_section(B3, C3, Q#dns_rec.arlist),
+    {B2,C2} = encode_res_section(OC, B1, C1, Q#dns_rec.anlist),
+    {B3,C3} = encode_res_section(OC, B2, C2, Q#dns_rec.nslist),
+    {B,_} = encode_res_section(OC, B3, C3, Q#dns_rec.arlist),
     B.
 
 
@@ -313,9 +321,9 @@ encode_query_section(Bin0, Comp0, [#dns_query{domain=DName}=Q | Qs]) ->
 %% RFC 1035:  4.1.3.               Resource record format
 %% RFC 6891:  6.1.2, 6.1.3, 6.2.3  Opt RR format
 %%
-encode_res_section(Bin, Comp, []) -> {Bin,Comp};
+encode_res_section(_Opcode, Bin, Comp, []) -> {Bin,Comp};
 encode_res_section(
-  Bin, Comp,
+  Opcode, Bin, Comp,
   [#dns_rr{
       domain = DName,
       type   = Type,
@@ -324,10 +332,10 @@ encode_res_section(
       ttl    = TTL,
       data   = Data} | Rs]) ->
     encode_res_section_rr(
-      Bin, Comp, Rs, DName, Type, Class, CacheFlush,
+      Opcode, Bin, Comp, Rs, DName, Type, Class, CacheFlush,
       <<TTL:32/signed>>, Data);
 encode_res_section(
-  Bin, Comp,
+  Opcode, Bin, Comp,
   [#dns_rr_opt{
       domain           = DName,
       udp_payload_size = UdpPayloadSize,
@@ -338,18 +346,24 @@ encode_res_section(
       do               = DnssecOk} | Rs]) ->
     DO = case DnssecOk of true -> 1; false -> 0 end,
     encode_res_section_rr(
-      Bin, Comp, Rs, DName, ?S_OPT, UdpPayloadSize, false,
+      Opcode, Bin, Comp, Rs, DName, ?S_OPT, UdpPayloadSize, false,
       <<ExtRCode,Version,DO:1,Z:15>>, Data).
 
 encode_res_section_rr(
-  Bin0, Comp0, Rs, DName, Type, Class, CacheFlush, TTL, Data) ->
+  Opcode, Bin0, Comp0, Rs, DName, Type, Class, CacheFlush, TTL, Data) ->
     T = encode_type(Type),
     C = encode_class(Class, CacheFlush),
     {Bin,Comp1} = encode_name(Bin0, Comp0, byte_size(Bin0), DName),
     Pos = byte_size(Bin)+(2+2)+byte_size(TTL)+2,
-    {DataBin,Comp} = encode_data(Comp1, Pos, Type, Class, Data),
+    {DataBin,Comp} = if
+        Opcode == update, Data == #dns_rr{}#dns_rr.data ->
+            {<<>>,Comp1};
+        true ->
+            encode_data(Comp1, Pos, Type, Class, Data)
+    end,
     DataSize = byte_size(DataBin),
     encode_res_section(
+      Opcode,
       <<Bin/binary,T:16,C:16,TTL/binary,DataSize:16,DataBin/binary>>,
       Comp, Rs).
 
@@ -450,6 +464,7 @@ decode_class(C0) ->
             ?C_IN    -> in;
             ?C_CHAOS -> chaos;
             ?C_HS    -> hs;
+            ?C_NONE  -> none;
             ?C_ANY   -> any;
             _ -> C    %% raw unknown class
         end,
@@ -469,6 +484,7 @@ encode_class(Class) ->
 	in    -> ?C_IN;
 	chaos -> ?C_CHAOS;
 	hs    -> ?C_HS;
+	none  -> ?C_NONE;
 	any   -> ?C_ANY;
 	Class when is_integer(Class) -> Class    %% raw unknown class
     end.
@@ -479,6 +495,7 @@ decode_opcode(Opcode) ->
 	?IQUERY -> iquery;
 	?STATUS -> status;
 	?NOTIFY -> notify;
+	?UPDATE -> update;
 	_ when is_integer(Opcode) -> Opcode %% non-standard opcode
     end.
 
@@ -488,6 +505,7 @@ encode_opcode(Opcode) ->
 	iquery -> ?IQUERY;
 	status -> ?STATUS;
 	notify -> ?NOTIFY;
+	update -> ?UPDATE;
 	_ when is_integer(Opcode) -> Opcode %% non-standard opcode
     end.
 
@@ -715,17 +733,6 @@ decode_name_label(Label, Name, N) ->
 %%
 %% Data field -> {binary(),NewCompressionTable}
 %%
-%% Class IN RRs
-encode_data(Comp, _, ?S_A, in, Addr) ->
-    {A,B,C,D} = Addr,
-    {<<A,B,C,D>>,Comp};
-encode_data(Comp, _, ?S_AAAA, in, Addr) ->
-    {A,B,C,D,E,F,G,H} = Addr,
-    {<<A:16,B:16,C:16,D:16,E:16,F:16,G:16,H:16>>,Comp};
-encode_data(Comp, _, ?S_WKS, in, Data) ->
-    {{A,B,C,D},Proto,BitMap} = Data,
-    BitMapBin = iolist_to_binary(BitMap),
-    {<<A,B,C,D,Proto,BitMapBin/binary>>,Comp};
 %% OPT pseudo-RR (of no class) - should not take this way;
 %% this must be a #dns_rr{type = ?S_OPT} instead of a #dns_rr_opt{},
 %% so good luck getting in particular Class and TTL right...
@@ -742,6 +749,16 @@ encode_data(Comp, Pos, Type, Class, Data) ->
 %%
 %%
 %% Standard RRs (any class)
+encode_data(Comp, _, ?S_A, Addr) ->
+    {A,B,C,D} = Addr,
+    {<<A,B,C,D>>,Comp};
+encode_data(Comp, _, ?S_AAAA, Addr) ->
+    {A,B,C,D,E,F,G,H} = Addr,
+    {<<A:16,B:16,C:16,D:16,E:16,F:16,G:16,H:16>>,Comp};
+encode_data(Comp, _, ?S_WKS, Data) ->
+    {{A,B,C,D},Proto,BitMap} = Data,
+    BitMapBin = iolist_to_binary(BitMap),
+    {<<A,B,C,D,Proto,BitMapBin/binary>>,Comp};
 encode_data(Comp, Pos, ?S_SOA, Data) ->
     {MName,RName,Serial,Refresh,Retry,Expiry,Minimum} = Data,
     {B1,Comp1} = encode_name(Comp, Pos, MName),
diff --git a/lib/kernel/src/inet_dns.hrl b/lib/kernel/src/inet_dns.hrl
index 39cdd4252f..17151fbb6a 100644
--- a/lib/kernel/src/inet_dns.hrl
+++ b/lib/kernel/src/inet_dns.hrl
@@ -28,6 +28,7 @@
 -define(IQUERY,   16#1).	%% inverse query
 -define(STATUS,   16#2).	%% nameserver status query
 -define(NOTIFY,   16#4).	%% notify
+-define(UPDATE,   16#5).	%% dynamic update
 
 %%
 %% Currently defined response codes
@@ -38,6 +39,11 @@
 -define(NXDOMAIN, 3).		%% non existent domain
 -define(NOTIMP,	  4).		%% not implemented
 -define(REFUSED,  5).		%% query refused
+-define(YXDOMAIN, 6).		%% name exists when it should not (DDNS)
+-define(YXRRSET,  7).		%% RR set exists when it should not (DDNS)
+-define(NXRRSET,  8).		%% RR set that should exist does not (DDNS)
+-define(NOTAUTH,  9).		%% server not authoritative for zone (DDNS)
+-define(NOTZONE,  10).		%% name not contained in zone (DDNS)
 -define(BADVERS,  16).		%% bad version EDNS pseudo-rr RFC6891: 6.1.3
 
 %%
@@ -134,6 +140,7 @@
 -define(C_IN,		1).      	%% the arpa internet
 -define(C_CHAOS,	3).		%% for chaos net at MIT
 -define(C_HS,		4).		%% for Hesiod name server at MIT
+-define(C_NONE,		254).		%% for DDNS (RFC2136, section 2.4)
 -define(C_ANY,		255).		%% wildcard match
 
 %%
@@ -161,9 +168,9 @@
 -record(dns_rec,
 	{
 	 header,       %% dns_header record
-	 qdlist = [],  %% list of question entries
-	 anlist = [],  %% list of answer entries
-	 nslist = [],  %% list of authority entries
+	 qdlist = [],  %% list of question (for UPDATE 'zone') entries
+	 anlist = [],  %% list of answer (for UPDATE 'prequisites') entries
+	 nslist = [],  %% list of authority (for UPDATE 'update') entries
 	 arlist = []   %% list of resource entries
 	}).
 
diff --git a/lib/kernel/src/inet_res.erl b/lib/kernel/src/inet_res.erl
index 0fb46332f2..f0d2f21364 100644
--- a/lib/kernel/src/inet_res.erl
+++ b/lib/kernel/src/inet_res.erl
@@ -1106,6 +1106,11 @@ decode_answer(Answer, Q_Msg, Verbose) ->
 		?NXDOMAIN -> {error,{nxdomain,Msg}};
 		?NOTIMP   -> {error,{notimp,Msg}};
 		?REFUSED  -> {error,{refused,Msg}};
+		?YXDOMAIN -> {error,{yxdomain,Msg}};
+		?YXRRSET  -> {error,{yxrrset,Msg}};
+		?NXRRSET  -> {error,{nxrrset,Msg}};
+		?NOTAUTH  -> {error,{noauth,Msg}};
+		?NOTZONE  -> {error,{nozone,Msg}};
 		?BADVERS  -> {error,{badvers,Msg}};
 		_         -> {error,{unknown,Msg}}
 	    end;
diff --git a/lib/kernel/test/inet_res_SUITE.erl b/lib/kernel/test/inet_res_SUITE.erl
index c620e6d93e..c69cf934ce 100644
--- a/lib/kernel/test/inet_res_SUITE.erl
+++ b/lib/kernel/test/inet_res_SUITE.erl
@@ -35,7 +35,7 @@
          edns0/1, edns0_multi_formerr/1, txt_record/1, files_monitor/1,
 	 nxdomain_reply/1, last_ms_answer/1, intermediate_error/1,
          servfail_retry_timeout_default/1, servfail_retry_timeout_1000/1,
-         label_compression_limit/1
+         label_compression_limit/1, update/1
         ]).
 -export([
 	 gethostbyaddr/0, gethostbyaddr/1,
@@ -77,7 +77,7 @@ all() ->
      nxdomain_reply, last_ms_answer,
      intermediate_error,
      servfail_retry_timeout_default, servfail_retry_timeout_1000,
-     label_compression_limit,
+     label_compression_limit, update,
      gethostbyaddr, gethostbyaddr_v6, gethostbyname,
      gethostbyname_v6, getaddr, getaddr_v6, ipv4_to_ipv6,
      host_and_addr].
@@ -133,6 +133,7 @@ zone_dir(TC) ->
 	files_monitor        -> otptest;
 	nxdomain_reply       -> otptest;
 	last_ms_answer       -> otptest;
+	update               -> otptest;
         intermediate_error   ->
             {internal,
              #{rcode => ?REFUSED}};
@@ -1412,6 +1413,63 @@ incr_domain([Char | Domain]) ->
     [Char+1 | Domain].
 
 
+%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% Test that the data portion can only be zero bytes for UPDATEs
+%% and that a real DNS server (Knot DNS) accepts our packet
+
+update(Config) when is_list(Config) ->
+    {NSIP,NSPort} = ns(Config),
+    Domain = "otptest",
+
+    % test that empty data for a query fails
+    QueryRec = #dns_rec{
+        header = #dns_header{ opcode = query },
+        anlist = [
+            #dns_rr{ domain = "test-update." ++ Domain, type = a }
+        ]
+    },
+    true = try inet_dns:encode(QueryRec) of
+        _ ->
+            false
+    catch
+        error:{badmatch,[]}:_ ->
+            true
+    end,
+
+    % test that empty data for an update
+    UpdateRec = #dns_rec{
+        header = #dns_header{ opcode = update },
+        % Zone
+        qdlist = [
+            #dns_query{ domain = Domain, class = in, type = soa }
+        ],
+        % Update
+        nslist = [
+            #dns_rr{
+                domain = "update-test." ++ Domain,
+                ttl = 300,
+                class = in,
+                type = a,
+                data = {192,0,2,1}
+            }
+        ]
+    },
+    UpdatePkt = inet_dns:encode(UpdateRec),
+    true = is_binary(UpdatePkt),
+
+    % check if an actual DNS server accepts it
+    SockOpts = [binary,{active,false}],
+    {ok,Sock} = gen_udp:open(0, SockOpts),
+    ok = gen_udp:connect(Sock, NSIP, NSPort),
+    ok = gen_udp:send(Sock, UpdatePkt),
+    {ok,{NSIP,NSPort,ResponsePkt}} = gen_udp:recv(Sock, 0),
+    ok = gen_udp:close(Sock),
+    {ok,ResponseRec} = inet_dns:decode(ResponsePkt),
+    #dns_rec{ header = #dns_header{ rcode = ?NOERROR } } = ResponseRec,
+
+    ok.
+
+
 %% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %% Compatibility tests. Call the inet_SUITE tests, but with
 %% lookup = [file,dns] instead of [native]
diff --git a/lib/kernel/test/inet_res_SUITE_data/otptest/knot_inc.conf b/lib/kernel/test/inet_res_SUITE_data/otptest/knot_inc.conf
index 6dd8c6dedf..50c9f0d977 100644
--- a/lib/kernel/test/inet_res_SUITE_data/otptest/knot_inc.conf
+++ b/lib/kernel/test/inet_res_SUITE_data/otptest/knot_inc.conf
@@ -1,4 +1,10 @@
+acl:
+  - id: update_rule
+    address: 127.0.0.1
+    action: update
+
 zone:
   - domain: otptest
+    acl: [ update_rule ]
   - domain: 0.0.127.in-addr.arpa.
   - domain: 0.0.0.0.f.7.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa.
-- 
2.35.3

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File 1769-inet_dns-support-UPDATE.patch of Package erlang (Revision 2f15b05a39d64e5cba90e927e8665465)

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