From: Andreas Gustafsson <source@isc.org>
Date: Mon, 11 Dec 2000 21:02:04 +0000 (+0000)
Subject: pullup:
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f7c0bec9fba40b662278e50604e3bb6cd5dd3ac9;p=thirdparty%2Fbind9.git

pullup:
Bitstring labels *still* suck.  They didn't somehow magically get less
sucky in the past couple of months.  The nerve.

Anyway, dns_name_split now correctly compacts the preceding bitstring label
(if any) when a maximal bitstring is split.

It also correctly creates the suffix when a maximal bitstring is split.
It was doing this incorrectly before, independent of the compaction issue.
---

diff --git a/lib/dns/name.c b/lib/dns/name.c
index 9c88601a127..8d5050beb23 100644
--- a/lib/dns/name.c
+++ b/lib/dns/name.c
@@ -15,7 +15,7 @@
  * SOFTWARE.
  */
 
-/* $Id: name.c,v 1.93.2.1 2000/10/16 23:32:34 bwelling Exp $ */
+/* $Id: name.c,v 1.93.2.2 2000/12/11 21:02:04 gson Exp $ */
 
 #include <config.h>
 
@@ -2592,11 +2592,12 @@ dns_name_split(dns_name_t *name,
 	       dns_name_t *prefix, dns_name_t *suffix)
 
 {
-	dns_offsets_t name_odata, split_odata;
-	unsigned char *offsets, *splitoffsets;
+	dns_offsets_t name_odata, prefix_odata, suffix_odata;
+	unsigned char *offsets, *prefix_offsets = NULL, *suffix_offsets;
 	isc_result_t result = ISC_R_SUCCESS;
 	unsigned int splitlabel, bitbytes, mod, len;
 	unsigned char *p, *src, *dst;
+	isc_boolean_t maybe_compact_prefix = ISC_FALSE;
 
 	REQUIRE(VALID_NAME(name));
 	REQUIRE((nbits == 0 &&
@@ -2665,11 +2666,14 @@ dns_name_split(dns_name_t *name,
 			}
 
 			/*
-			 * Set the new bit count.
+			 * Set the new bit count.  Also, when a bitstring
+			 * label being split is maximal length, compaction
+			 * might be necessary on the prefix.
 			 */
-			if (*p == 0)
+			if (*p == 0) {
+				maybe_compact_prefix = ISC_TRUE;
 				*p = 256 - nbits;
-			else
+			} else
 				*p = *p - nbits;
 
 			/*
@@ -2743,8 +2747,8 @@ dns_name_split(dns_name_t *name,
 			 */
 			INSIST(len = prefix->length);
 
-			INIT_OFFSETS(prefix, splitoffsets, split_odata);
-			set_offsets(prefix, splitoffsets, prefix);
+			INIT_OFFSETS(prefix, prefix_offsets, prefix_odata);
+			set_offsets(prefix, prefix_offsets, prefix);
 
 			INSIST(prefix->labels == splitlabel + 1 &&
 			       prefix->length == len);
@@ -2768,7 +2772,9 @@ dns_name_split(dns_name_t *name,
 			 * the new name.
 			 */
 			src = &name->ndata[offsets[splitlabel] + 1];
-			len = (*src++ - 1) / 8 - (bitbytes - 1);
+			len = ((*src == 0 ? 256 : *src) - 1) / 8;
+			len -= (bitbytes - 1);
+			src++;
 
 			suffix->length = name->length -
 				offsets[splitlabel] - len;
@@ -2844,8 +2850,8 @@ dns_name_split(dns_name_t *name,
 			 */
 			INSIST(len = suffix->length);
 
-			INIT_OFFSETS(suffix, splitoffsets, split_odata);
-			set_offsets(suffix, splitoffsets, suffix);
+			INIT_OFFSETS(suffix, suffix_offsets, suffix_odata);
+			set_offsets(suffix, suffix_offsets, suffix);
 
 			INSIST(suffix->labels == suffixlabels &&
 			       suffix->length == len);
@@ -2856,6 +2862,16 @@ dns_name_split(dns_name_t *name,
 
 	}
 
+	/*
+	 * Compacting the prefix can't be done until after the suffix is
+	 * set, because it would screw up the offsets table of 'name'
+	 * when 'name' == 'prefix'.
+	 */
+	if (maybe_compact_prefix && splitlabel > 0 &&
+	    prefix->ndata[prefix_offsets[splitlabel - 1]] ==
+	    DNS_LABELTYPE_BITSTRING)
+		compact(prefix, prefix_offsets);
+
 	return (result);
 }