Add descriptors for some obsolete records

src/common/descriptor.c

@@ -136,6 +136,30 @@ static const rdata_descriptor_t rdata_descriptors[] = {
 	                               KNOT_RDATA_WF_END }, "ANY" },
 };
 
+/*!
+ * \brief Some (OBSOLETE) RR type descriptors.
+ */
+static const rdata_descriptor_t obsolete_rdata_descriptors[] = {
+	[0]                      = { { KNOT_RDATA_WF_REMAINDER,
+	                               KNOT_RDATA_WF_END }, NULL },
+	[KNOT_RRTYPE_MD]         = { { KNOT_RDATA_WF_COMPRESSED_DNAME,
+	                               KNOT_RDATA_WF_END }, "MD" },
+	[KNOT_RRTYPE_MF]         = { { KNOT_RDATA_WF_COMPRESSED_DNAME,
+	                               KNOT_RDATA_WF_END }, "MF" },
+	[KNOT_RRTYPE_MB]         = { { KNOT_RDATA_WF_COMPRESSED_DNAME,
+	                               KNOT_RDATA_WF_END }, "MB" },
+	[KNOT_RRTYPE_MG]         = { { KNOT_RDATA_WF_COMPRESSED_DNAME,
+	                               KNOT_RDATA_WF_END }, "MG" },
+	[KNOT_RRTYPE_MR]         = { { KNOT_RDATA_WF_COMPRESSED_DNAME,
+	                               KNOT_RDATA_WF_END }, "MR" },
+	[KNOT_RRTYPE_PX]         = { { 2, KNOT_RDATA_WF_COMPRESSED_DNAME,
+	                               KNOT_RDATA_WF_COMPRESSED_DNAME,
+	                               KNOT_RDATA_WF_END }, "PX" },
+	[KNOT_RRTYPE_NXT]        = { { KNOT_RDATA_WF_COMPRESSED_DNAME,
+	                               KNOT_RDATA_WF_REMAINDER,
+	                               KNOT_RDATA_WF_END }, "NXT" },
+};
+
 const rdata_descriptor_t *get_rdata_descriptor(const uint16_t type)
 {
 	if (type <= KNOT_RRTYPE_ANY && rdata_descriptors[type].type_name != 0) {
@@ -145,6 +169,16 @@ const rdata_descriptor_t *get_rdata_descriptor(const uint16_t type)
 	}
 }
 
+const rdata_descriptor_t *get_obsolete_rdata_descriptor(const uint16_t type)
+{
+	if (type <= KNOT_RRTYPE_NXT &&
+	    obsolete_rdata_descriptors[type].type_name != 0) {
+		return &obsolete_rdata_descriptors[type];
+	} else {
+		return &obsolete_rdata_descriptors[0];
+	}
+}
+
 int knot_rrtype_to_string(const uint16_t rrtype,
                           char           *out,
                           const size_t   out_len)

src/common/descriptor.h

@@ -109,6 +109,25 @@ enum knot_rr_type {
 	KNOT_RRTYPE_ANY        = 255  /*!< QTYPE. Any record. */
 };
 
+/*!
+ * \brief Some (OBSOLETE) resource record type constants.
+ *
+ * http://www.iana.org/assignments/dns-parameters/dns-parameters.xml
+ *
+ * \note These records can contain compressed domain name in rdata so
+ *       it is important to know the position of it during transfers.
+ *       See RFC 3597#4.
+ */
+enum knot_obsolete_rr_type {
+	KNOT_RRTYPE_MD         =   3,
+	KNOT_RRTYPE_MF         =   4,
+	KNOT_RRTYPE_MB         =   7,
+	KNOT_RRTYPE_MG         =   8,
+	KNOT_RRTYPE_MR         =   9,
+	KNOT_RRTYPE_PX         =  26,
+	KNOT_RRTYPE_NXT        =  30
+};
+
 /*!
  * \brief Constants characterising the wire format of RDATA items.
  */
@@ -138,13 +157,23 @@ typedef struct {
 /*!
  * \brief Gets rdata descriptor for given RR name.
  *
- * \param name Mnemonic of RR type whose descriptor should be retvaled.
+ * \param name Mnemonic of RR type whose descriptor should be returned.
  *
  * \retval RR descriptor for given name, NULL descriptor if
  *         unknown type.
  */
 const rdata_descriptor_t *get_rdata_descriptor(const uint16_t type);
 
+/*!
+ * \brief Gets rdata descriptor for given RR name (obsolete version).
+ *
+ * \param name Mnemonic of RR type whose descriptor should be returned.
+ *
+ * \retval RR descriptor for given name, NULL descriptor if
+ *         unknown type.
+ */
+const rdata_descriptor_t *get_obsolete_rdata_descriptor(const uint16_t type);
+
 /*!
  * \brief Converts numeric type representation to mnemonic string.
  *

src/tests/common/descriptor_tests.c

@@ -36,7 +36,7 @@ unit_api descriptor_tests_api = {
 
 static int descriptor_tests_count(int argc, char *argv[])
 {
-	return 68;
+	return 81;
 }
 
 static int descriptor_tests_run(int argc, char *argv[])
@@ -230,5 +230,40 @@ static int descriptor_tests_run(int argc, char *argv[])
 	ret = knot_rrclass_from_string("CLASS65536", &num);
 	cmp_ok(ret, "==", -1, "get CLASS65536 num ret");
 
+	// Get obsolete descriptor:
+	// 30. TYPE0
+	descr = get_obsolete_rdata_descriptor(0);
+	ok(descr->type_name == 0, "get TYPE0 descriptor name");
+	cmp_ok(descr->block_types[0], "==", KNOT_RDATA_WF_REMAINDER,
+	       "get TYPE0 descriptor 1. item type");
+	cmp_ok(descr->block_types[1], "==", KNOT_RDATA_WF_END,
+	       "get TYPE0 descriptor 2. item type");
+
+	// 31. MD
+	descr = get_obsolete_rdata_descriptor(3);
+	ok(strcmp(descr->type_name, "MD") == 0, "get MD descriptor name");
+	cmp_ok(descr->block_types[0], "==", KNOT_RDATA_WF_COMPRESSED_DNAME,
+	       "get A descriptor 1. item type");
+	cmp_ok(descr->block_types[1], "==", KNOT_RDATA_WF_END,
+	       "get A descriptor 2. item type");
+
+	// 32. NXT
+	descr = get_obsolete_rdata_descriptor(30);
+	ok(strcmp(descr->type_name, "NXT") == 0, "get NXT descriptor name");
+	cmp_ok(descr->block_types[0], "==", KNOT_RDATA_WF_COMPRESSED_DNAME,
+	       "get CNAME descriptor 1. item type");
+	cmp_ok(descr->block_types[1], "==", KNOT_RDATA_WF_REMAINDER,
+	       "get CNAME descriptor 2. item type");
+	cmp_ok(descr->block_types[2], "==", KNOT_RDATA_WF_END,
+	       "get CNAME descriptor 3. item type");
+
+	// 33. TYPE38 (A6)
+	descr = get_obsolete_rdata_descriptor(38);
+	ok(descr->type_name == 0, "get TYPE38 descriptor name");
+	cmp_ok(descr->block_types[0], "==", KNOT_RDATA_WF_REMAINDER,
+	       "get TYPE38 descriptor 1. item type");
+	cmp_ok(descr->block_types[1], "==", KNOT_RDATA_WF_END,
+	       "get TYPE38 descriptor 2. item type");
+
 	return 0;
 }