Treat TYPE0 like any other unknown type

Author: k0ekk0ek

FORMAT.md

@@ -225,3 +225,6 @@ anything other than domain names and text strings, MUST not be quoted.
 
 * BIND10 had a nice writeup on zone files, kindly provided by Shane Kerr.
   [Zone File Loading Requirements on Wayback Machine](https://web.archive.org/web/20140928215002/http://bind10.isc.org:80/wiki/ZoneLoadingRequirements)
+
+* `TYPE0` is sometimes used for debugging and therefore may occur in type
+  bitmaps or as unknown RR type.

src/generic/types.h

@@ -123,27 +123,6 @@ static really_inline ssize_t check_ttl(
   return 4;
 }
 
-zone_nonnull((1,2,3,4))
-static really_inline ssize_t check_type(
-  parser_t *parser,
-  const type_info_t *type,
-  const rdata_info_t *field,
-  const uint8_t *data,
-  const size_t length)
-{
-  uint16_t number;
-
-  if (length < sizeof(number))
-    SYNTAX_ERROR(parser, "Missing %s in %s", NAME(field), NAME(type));
-
-  memcpy(&number, data, sizeof(number));
-
-  if (!number)
-    SEMANTIC_ERROR(parser, "Invalid %s in %s", NAME(field), NAME(type));
-
-  return 2;
-}
-
 zone_nonnull((1,2,3,4))
 static really_inline ssize_t check_name(
   parser_t *parser,
@@ -1584,7 +1563,7 @@ static int32_t check_rrsig_rr(
   const uint8_t *o = parser->rdata->octets;
   const rdata_info_t *f = type->rdata.fields;
 
-  if ((r = check(&c, check_type(parser, type, &f[0], o, n))) ||
+  if ((r = check(&c, check_int16(parser, type, &f[0], o, n))) ||
       (r = check(&c, check_int8(parser, type, &f[1], o+c, n-c))) ||
       (r = check(&c, check_int8(parser, type, &f[2], o+c, n-c))) ||
       (r = check(&c, check_ttl(parser, type, &f[3], o+c, n-c))) ||
@@ -2845,6 +2824,7 @@ static const rdata_info_t dlv_rdata_fields[] = {
   FIELD("digest")
 };
 
+// https://www.iana.org/assignments/dns-parameters/dns-parameters.xhtml
 static const type_info_t types[] = {
   UNKNOWN_TYPE(0),
 

tests/types.c

@@ -867,6 +867,11 @@ static const char dlv_text[] =
 static const char dlv_generic_text[] =
   PAD("foo. DLV \\# 24 e466 05 01 3079f1593ebad6dc121e202a8b766a6a4837206c");
 
+static const char type0_generic_text[] =
+  PAD("foo. TYPE0 \\# 6 666f6f626172");
+static const rdata_t type0_rdata =
+  RDATA('f', 'o', 'o', 'b', 'a', 'r');
+
 typedef struct test test_t;
 struct test {
   const uint16_t type;
@@ -876,6 +881,7 @@ struct test {
 
 
 static const test_t tests[] = {
+  { 0, type0_generic_text, &type0_rdata },
   { ZONE_A, a_text, &a_rdata },
   { ZONE_A, a_generic_text, &a_rdata },
   { ZONE_NS, ns_text, &ns_rdata },