decode multiple DNS labels for the tests

and fix issues with the decoder.

src/bin/unit_test_attribute.c

@@ -1301,32 +1301,52 @@ static size_t command_decode_dns_label(command_result_t *result, UNUSED command_
 				       char *data, UNUSED size_t data_used, char *in, size_t inlen)
 {
 	size_t len;
-	ssize_t slen;
+	ssize_t slen, total, i;
 	uint8_t dns_label[1024];
+	char *out, *end;
 	fr_value_box_t *box = talloc_zero(NULL, fr_value_box_t);
 
 	/*
 	 *	Decode hex from input text
 	 */
-	slen = hex_to_bin(dns_label, sizeof(dns_label), in, inlen);
-	if (slen <= 0) RETURN_PARSE_ERROR(-(slen));
+	total = hex_to_bin(dns_label, sizeof(dns_label), in, inlen);
+	if (total <= 0) RETURN_PARSE_ERROR(-total);
 
-	/*
-	 *	@todo - decode multiple labels, and print them with commas separating them.
-	 */
-	slen = fr_value_box_from_dns_label(box, box, dns_label, slen, dns_label, false);
-	if (slen < 0) {
-		talloc_free(box);
-		RETURN_OK_WITH_ERROR();
+	out = data;
+	end = data + COMMAND_OUTPUT_MAX;
+
+	for (i = 0; i < total; i += slen) {
+		slen = fr_value_box_from_dns_label(box, box, dns_label, total, dns_label + i, false);
+		if (slen < 0) {
+			talloc_free(box);
+			RETURN_OK_WITH_ERROR();
+		}
+
+		/*
+		 *	Separate names by commas
+		 */
+		if (i > 0) *(out++) = ',';
+
+		/*
+		 *	As a special case, print '.' if there is no label
+		 */
+		if (box->vb_length == 0) {
+		       *(out++) = '.';
+		       *out = '\0';
+
+		} else {
+			/*
+			 *	We don't print it with quotes.
+			 */
+			len = fr_value_box_snprint(out, end - out, box, '\0');
+			out += len;
+		}
+
+		fr_value_box_clear(box);
 	}
 
-	/*
-	 *	We don't print it with quotes.
-	 */
-	len = fr_value_box_snprint(data, COMMAND_OUTPUT_MAX, box, '\0');
 	talloc_free(box);
-
-	RETURN_OK(len);
+	RETURN_OK(out - data);
 }
 
 static size_t command_encode_pair(command_result_t *result, command_ctx_t *cc,

src/lib/util/value.c

@@ -1625,7 +1625,19 @@ ssize_t fr_dns_label_length(uint8_t const *buf, size_t buf_len, uint8_t const **
 	 *	We silently accept labels *without* a trailing 0x00,
 	 *	so long as they end at the end of the input buffer.
 	 */
-	while (*p != 0x00) {
+	while (p < end) {
+		/*
+		 *	End of label byte.  Skip it.
+		 *
+		 *	If necessary, also tell the caller to skip
+		 *	over it, too.
+		 */
+		if (*p == 0x00) {
+			p++;
+			if (at_first_label) length++;
+			break;
+		}
+
 		/*
 		 *	Maybe it's a compression pointer.
 		 */
@@ -1776,9 +1788,11 @@ ssize_t fr_dns_labels_network_verify(uint8_t const *buf, size_t buf_len)
 	return buf_len;
 }
 
-static ssize_t dns_label_decode(uint8_t const *buf, uint8_t const *label, uint8_t const **next)
+static ssize_t dns_label_decode(uint8_t const *buf, uint8_t const **p_label, uint8_t const **next)
 {
-	uint8_t const *p = label;
+	uint8_t const *p;
+
+	p = *p_label;
 
 	if (*p == 0x00) {
 		*next = p + 1;
@@ -1798,6 +1812,7 @@ static ssize_t dns_label_decode(uint8_t const *buf, uint8_t const *label, uint8_
 		p = buf + offset;
 	}
 
+	*p_label = p;
 	*next = p + *p + 1;
 	return *p;
 }
@@ -1835,26 +1850,29 @@ ssize_t fr_value_box_from_dns_label(TALLOC_CTX *ctx, fr_value_box_t *dst,
 	 *	label after this one.
 	 */
 	slen = fr_dns_label_length(src, len, &after);
-	if (slen < 0) return slen;
+	if (slen <= 0) return slen;
 
-	/*
-	 *	Allocate the string and set up the value_box
-	 */
-	dst->vb_strvalue = q = talloc_zero_array(ctx, char, slen + 1);
-	dst->datum.length = slen;
 	dst->type = FR_TYPE_STRING;
 	dst->tainted = tainted;
 	dst->enumv = NULL;
 	dst->next = NULL;
 
 	/*
-	 *	An empty label, just create an empty string.
+	 *	An empty label is a 0x00 byte.  Just create an empty
+	 *	string.
 	 */
-	if (slen == 0) {
-		*q = '\0';
+	if (slen == 1) {
+		dst->vb_strvalue = talloc_zero_array(ctx, char, 1);
+		dst->datum.length = 0;
 		return after - label;
 	}
 
+	/*
+	 *	Allocate the string and set up the value_box
+	 */
+	dst->vb_strvalue = q = talloc_array(ctx, char, slen + 1);
+	dst->datum.length = slen;
+
 	current = label;
 	p = (uint8_t *) q;
 	q += slen;
@@ -1864,7 +1882,7 @@ ssize_t fr_value_box_from_dns_label(TALLOC_CTX *ctx, fr_value_box_t *dst,
 		 *	Get how many bytes this label has, and where
 		 *	we will go to obtain the next label.
 		 */
-		slen = dns_label_decode(src, current, &next);
+		slen = dns_label_decode(src, &current, &next);
 		if (slen < 0) {
 		fail:
 			fr_value_box_clear(dst);

src/tests/unit/data_types.txt

@@ -107,14 +107,23 @@ match foo.com
 encode-dns-label foo.com,b.ca
 match 03 66 6f 6f 03 63 6f 6d 00 01 62 02 63 61 00
 
+decode-dns-label -
+match foo.com,b.ca
+
 # root gets encoded as a plain 0.
 encode-dns-label .
 match 00
 
+decode-dns-label -
+match .
+
 # From RFC 1035 Section 4.1.4
-encode-dns-label F.ISI.ARPA,FOO.F.ISI.ARPA, ARPA, .
+encode-dns-label F.ISI.ARPA,FOO.F.ISI.ARPA,ARPA,.
 match 01 46 03 49 53 49 04 41 52 50 41 00 03 46 4f 4f c0 00 c0 06 00
 
+decode-dns-label -
+match F.ISI.ARPA,FOO.F.ISI.ARPA,ARPA,.
+
 
 count
-match 52
+match 58