Add dns_rdata_totext() and dns_rdata_fromtext() to fromwire

Add dns_rdata_totext() and dns_rdata_fromtext() to fromwire for
valid inputs to ensure that what we accept in dns_rdata_fromwire()
can be written out and read back in.

(cherry picked from commit 36f30f57313747c536ea9afcd037086edea3ecb0)

diff --git a/lib/dns/tests/rdata_test.c b/lib/dns/tests/rdata_test.c
index 70e2499cf10ca4dd75e30e0fb69f24fdece03ae6..b7b66f3d37011c29ec970ea573b84afd52c69292 100644 (file)
--- a/lib/dns/tests/rdata_test.c
+++ b/lib/dns/tests/rdata_test.c
@@ -236,6 +236,12 @@ check_text_ok_single(const text_ok_t *text_ok, dns_rdataclass_t rdclass,
        isc_buffer_init(&target, buf_totext, sizeof(buf_totext));
        result = dns_rdata_totext(&rdata, NULL, &target);
        assert_int_equal(result, ISC_R_SUCCESS);
+       /*
+        * Ensure buf_totext is properly NUL terminated as dns_rdata_totext()
+        * may attempt different output formats writing into the apparently
+        * unused part of the buffer.
+        */
+       isc_buffer_putuint8(&target, 0);
        assert_string_equal(buf_totext, text_ok->text_out);
 
        /*
@@ -254,6 +260,49 @@ check_text_ok_single(const text_ok_t *text_ok, dns_rdataclass_t rdclass,
        check_struct_conversions(&rdata, structsize);
 }
 
+/*
+ * Test whether converting rdata to text form and then parsing the result of
+ * that conversion again results in the same uncompressed wire form.  This
+ * checks whether totext_*() output is parsable by fromtext_*() for given RR
+ * class and type.
+ *
+ * This function is called for every input RDATA which is successfully parsed
+ * by check_wire_ok_single() and whose type is not a meta-type.
+ */
+static void
+check_text_conversions(dns_rdata_t *rdata) {
+       char buf_totext[1024] = { 0 };
+       unsigned char buf_fromtext[1024];
+       isc_result_t result;
+       isc_buffer_t target;
+       dns_rdata_t rdata2 = DNS_RDATA_INIT;
+
+       /*
+        * Convert uncompressed wire form RDATA into text form.  This
+        * conversion must succeed since input RDATA was successfully
+        * parsed by check_wire_ok_single().
+        */
+       isc_buffer_init(&target, buf_totext, sizeof(buf_totext));
+       result = dns_rdata_totext(rdata, NULL, &target);
+       assert_int_equal(result, ISC_R_SUCCESS);
+       /*
+        * Ensure buf_totext is properly NUL terminated as dns_rdata_totext()
+        * may attempt different output formats writing into the apparently
+        * unused part of the buffer.
+        */
+       isc_buffer_putuint8(&target, 0);
+
+       /*
+        * Try parsing text form RDATA output by dns_rdata_totext() again.
+        */
+       result = dns_test_rdatafromstring(&rdata2, rdata->rdclass, rdata->type,
+                                         buf_fromtext, sizeof(buf_fromtext),
+                                         buf_totext, false);
+       assert_int_equal(result, ISC_R_SUCCESS);
+       assert_int_equal(rdata2.length, rdata->length);
+       assert_memory_equal(buf_fromtext, rdata->data, rdata->length);
+}
+
 /*
  * Test whether supplied wire form RDATA is properly handled as being either
  * valid or invalid for an RR of given rdclass and type.
@@ -282,9 +331,15 @@ check_wire_ok_single(const wire_ok_t *wire_ok, dns_rdataclass_t rdclass,
        /*
         * If data was parsed correctly, perform two-way conversion checks
         * between uncompressed wire form and type-specific struct.
+        *
+        * If the RR type is not a meta-type, additionally perform two-way
+        * conversion checks between uncompressed wire form and text form.
         */
        if (result == ISC_R_SUCCESS) {
                check_struct_conversions(&rdata, structsize);
+               if (!dns_rdatatype_ismeta(rdata.type)) {
+                       check_text_conversions(&rdata);
+               }
        }
 }