dname isroot and dellabel

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

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 */