Implement compression pointer rollback.

dns_compress_backout() -> dns_compress_rollback()

bin/tests/compress_test.c

@@ -150,6 +150,7 @@ test(unsigned int allowed, dns_name_t *name1, dns_name_t *name2,
 	RUNTIME_CHECK(dns_name_towire(name3, &cctx, &source) == DNS_R_SUCCESS);
 
 	dns_compress_localinvalidate(&cctx);
+	dns_compress_rollback(&cctx, 0);	/* testing only */
 	dns_compress_invalidate(&cctx);
 
 	if (raw) {

lib/dns/compress.c

@@ -15,7 +15,7 @@
  * SOFTWARE.
  */
 
- /* $Id: compress.c,v 1.14 1999/04/28 03:16:50 marka Exp $ */
+ /* $Id: compress.c,v 1.15 1999/05/03 03:07:16 marka Exp $ */
 
 #include <config.h>
 #include <string.h>
@@ -340,12 +340,65 @@ dns_compress_add(dns_compress_t *cctx, dns_name_t *prefix,
 }
 
 void
-dns_compress_backout(dns_compress_t *cctx, isc_uint16_t offset) {
+dns_compress_rollback(dns_compress_t *cctx, isc_uint16_t offset) {
+	dns_rbtnode_t *node;
+	dns_fixedname_t foundfixed;
+	dns_fixedname_t fullfixed;
+	dns_fixedname_t originfixed;
+	dns_name_t *foundname;
+	dns_name_t *fullname;
+	dns_name_t *origin;
+	dns_rbtnodechain_t chain;
+	dns_result_t result;
+
 	REQUIRE(VALID_CCTX(cctx));
 
-	/* XXX MPA need tree walking code */
-	/* Remove all nodes in cctx->global that have *data >= offset. */
+	/*
+	 * Initalise things.
+	 */
+	dns_fixedname_init(&foundfixed);
+	foundname = dns_fixedname_name(&foundfixed);
+	dns_fixedname_init(&fullfixed);
+	fullname = dns_fixedname_name(&fullfixed);
+	dns_fixedname_init(&originfixed);
+	origin = dns_fixedname_name(&originfixed);
+	dns_rbtnodechain_init(&chain, cctx->mctx);
 
+ again:
+	result = dns_rbtnodechain_first(&chain, cctx->global, foundname,
+					origin);
+
+	while (result == DNS_R_NEWORIGIN || result == DNS_R_SUCCESS) {
+		result = dns_rbtnodechain_current(&chain, foundname,
+						  origin, &node);
+
+		if (result != DNS_R_SUCCESS)
+			break;
+
+		if (node->data != NULL &&
+		    (*(isc_uint16_t*)node->data >= offset)) {
+			result = dns_name_concatenate(foundname,
+					dns_name_isabsolute(foundname) ?
+						      NULL : origin,
+						      fullname, NULL);
+
+			if (result != DNS_R_SUCCESS)
+				break;
+
+			result = dns_rbt_deletename(cctx->global, fullname,
+						    ISC_FALSE);
+			if (result != DNS_R_SUCCESS)
+				break;
+			/*
+			 * If the delete is successful the chain is broken.
+			 */
+			dns_rbtnodechain_reset(&chain);
+			goto again;
+		}
+
+		result = dns_rbtnodechain_next(&chain, foundname, origin);
+	}
+	dns_rbtnodechain_invalidate(&chain);
 }
 
 /***
@@ -375,7 +428,7 @@ dns_decompress_localinit(dns_decompress_t *dctx, dns_name_t *name,
 	REQUIRE(dns_name_isabsolute(name) == ISC_TRUE);
 	REQUIRE(isc_buffer_type(source) == ISC_BUFFERTYPE_BINARY);
 
-	dctx->rdata = source->current;
+	dctx->rdata = source->current;	/* XXX layer violation */
 	dctx->owner_name = *name;
 }
 

lib/dns/include/dns/compress.h

@@ -224,7 +224,7 @@ dns_compress_add(dns_compress_t *cctx, dns_name_t *prefix,
  */
 
 void
-dns_compress_backout(dns_compress_t *cctx, isc_uint16_t offset);
+dns_compress_rollback(dns_compress_t *cctx, isc_uint16_t offset);
 
 /*
  *	Remove any compression pointers from global RBT >= offset.

lib/dns/rdata.c

@@ -15,7 +15,7 @@
  * SOFTWARE.
  */
 
- /* $Id: rdata.c,v 1.38 1999/03/11 00:29:10 marka Exp $ */
+ /* $Id: rdata.c,v 1.39 1999/05/03 03:07:15 marka Exp $ */
 
 #include <config.h>
 
@@ -37,6 +37,8 @@
 #include <dns/rcode.h>
 #include <dns/cert.h>
 #include <dns/secalg.h>
+#include <dns/fixedname.h>
+#include <dns/rdatastruct.h>
 
 #define RETERR(x) do { \
 	dns_result_t __r = (x); \
@@ -317,7 +319,7 @@ dns_rdata_towire(dns_rdata_t *rdata, dns_compress_t *cctx,
 	}
 	if (result != DNS_R_SUCCESS) {
 		*target = st;
-		dns_compress_backout(cctx, target->used);
+		dns_compress_rollback(cctx, target->used);
 	}
 	return (result);
 }
@@ -472,7 +474,6 @@ dns_rdata_tostruct(dns_rdata_t *rdata, void *target) {
 	isc_boolean_t use_default = ISC_FALSE;
 
 	REQUIRE(rdata != NULL);
-	REQUIRE(isc_buffer_type(target) == ISC_BUFFERTYPE_BINARY);
 
 	TOSTRUCTSWITCH
 

lib/dns/rdataset.c

@@ -319,7 +319,8 @@ dns_rdataset_towire(dns_rdataset_t *rdataset,
 		st = *target;
 		result = dns_name_towire(owner_name, cctx, target);
 		if (result != DNS_R_SUCCESS) {
-			dns_compress_backout(cctx, st.used);
+			dns_compress_rollback(cctx, st.used);
+			*countp += count;
 			*target = st;
 			return (result);
 		}
@@ -329,7 +330,8 @@ dns_rdataset_towire(dns_rdataset_t *rdataset,
 				+ 2;  /* XXX 2 for rdata len */
 		isc_buffer_available(target, &r);
 		if (r.length < headlen) {
-			dns_compress_backout(cctx, st.used);
+			dns_compress_rollback(cctx, st.used);
+			*countp += count;
 			*target = st;
 			return (DNS_R_NOSPACE);
 		}
@@ -351,14 +353,16 @@ dns_rdataset_towire(dns_rdataset_t *rdataset,
 			result = dns_compress_localinit(cctx, owner_name,
 							target);
 			if (result != DNS_R_SUCCESS) {
-				dns_compress_backout(cctx, st.used);
+				dns_compress_rollback(cctx, st.used);
+				*countp += count;
 				*target = st;
 				return (result);
 			}
 			result = dns_rdata_towire(&rdata, cctx, target);
 			dns_compress_localinvalidate(cctx);
 			if (result != DNS_R_SUCCESS) {
-				dns_compress_backout(cctx, st.used);
+				dns_compress_rollback(cctx, st.used);
+				*countp += count;
 				*target = st;
 				return (result);
 			}