dname isroot and dellabel

git-svn-id: file:///svn/unbound/trunk@492 be551aaa-1e26-0410-a405-d3ace91eadb9

doc/Changelog

@@ -1,5 +1,6 @@
 6 August 2007: Wouter
 	- key cache for validator.
+	- moved isroot and dellabel to own dname routines, with unit test.
 
 3 August 2007: Wouter
 	- replanning.

iterator/iterator.c

@@ -643,11 +643,9 @@ processInitRequest(struct module_qstate* qstate, struct iter_qstate* iq,
 		delnamelen = iq->qchase.qname_len;
 	}
 	if((iq->qchase.qtype == LDNS_RR_TYPE_DS || iq->refetch_glue)
-		&& delname[0] != 0) {
+		&& !dname_is_root(delname)) {
 		/* do not adjust root label, remove first label from delname */
-		size_t lablen = delname[0] + 1;
-		delname += lablen;
-		delnamelen -= lablen;
+		dname_remove_label(&delname, &delnamelen);
 	}
 	
 	/* Lookup the delegation in the cache. If null, then the cache needs 

testcode/unitdname.c

@@ -433,6 +433,36 @@ dname_test_strict_subdomain()
 		(uint8_t*)"\007example\003org", 3));
 }
 
+/** test dname_is_root */
+static void
+dname_test_isroot()
+{
+	unit_assert(dname_is_root((uint8_t*)"\000"));
+	unit_assert(!dname_is_root((uint8_t*)"\001a\000"));
+	unit_assert(!dname_is_root((uint8_t*)"\005abvcd\003com\000"));
+	/* malformed dname in this test, but should work */
+	unit_assert(!dname_is_root((uint8_t*)"\077a\000"));
+	unit_assert(dname_is_root((uint8_t*)"\000"));
+}
+
+/** test dname_remove_label */
+static void
+dname_test_removelabel()
+{
+	uint8_t* orig = (uint8_t*)"\007example\003com\000";
+	uint8_t* n = orig;
+	size_t l = 13;
+	dname_remove_label(&n, &l);
+	unit_assert( n == orig+8 );
+	unit_assert( l == 5 );
+	dname_remove_label(&n, &l);
+	unit_assert( n == orig+12 );
+	unit_assert( l == 1 );
+	dname_remove_label(&n, &l);
+	unit_assert( n == orig+12 );
+	unit_assert( l == 1 );
+}
+
 void dname_test()
 {
 	ldns_buffer* buff = ldns_buffer_new(65800);
@@ -446,5 +476,7 @@ void dname_test()
 	dname_test_pkt_dname_len(buff);
 	dname_test_strict_subdomain();
 	dname_test_subdomain();
+	dname_test_isroot();
+	dname_test_removelabel();
 	ldns_buffer_free(buff);
 }

util/data/dname.c

@@ -571,3 +571,27 @@ dname_subdomain_c(uint8_t* d1, uint8_t* d2)
 	}
 	return (m == labs2);
 }
+
+int 
+dname_is_root(uint8_t* dname)
+{
+	uint8_t len;
+	log_assert(dname);
+	len = dname[0];
+	log_assert(!LABEL_IS_PTR(len));
+	return (len == 0);
+}
+
+void 
+dname_remove_label(uint8_t** dname, size_t* len)
+{
+	size_t lablen;
+	log_assert(dname && *dname && len);
+	lablen = (*dname)[0];
+	log_assert(!LABEL_IS_PTR(lablen));
+	log_assert(*len > lablen);
+	if(lablen == 0)
+		return; /* do not modify root label */
+	*len -= lablen+1;
+	*dname += lablen+1;
+}

util/data/dname.h

@@ -207,4 +207,19 @@ void dname_print(FILE* out, ldns_buffer* pkt, uint8_t* dname);
  */
 void dname_str(uint8_t* dname, char* str);
 
+/**
+ * Returns true if the uncompressed wireformat dname is the root "."
+ * @param dname: the dname to check
+ * @return true if ".", false if not.
+ */
+int dname_is_root(uint8_t* dname);
+
+/**
+ * Snip off first label from a dname, returning the parent zone.
+ * @param dname: from what to strip off. uncompressed wireformat.
+ * @param len: length, adjusted to become less.
+ * @return stripped off, or "." if input was ".".
+ */
+void dname_remove_label(uint8_t** dname, size_t* len);
+
 #endif /* UTIL_DATA_DNAME_H */

validator/val_kcache.c

@@ -43,6 +43,7 @@
 #include "validator/val_kentry.h"
 #include "util/log.h"
 #include "util/config_file.h"
+#include "util/data/dname.h"
 
 struct key_cache* 
 key_cache_create(struct config_file* cfg)
@@ -140,10 +141,9 @@ key_cache_obtain(struct key_cache* kcache, uint8_t* name, size_t namelen,
 			lock_rw_unlock(&k->entry.lock);
 		}
 		/* snip off first label to continue */
-		if(name[0] == 0 || namelen <= 1)
+		if(dname_is_root(name))
 			break;
-		namelen -= (size_t)name[0] + 1;
-		name += (size_t)name[0] + 1;
+		dname_remove_label(&name, &namelen);
 	}
 	return NULL;
 }