Use unsigned bytearray for dname lookup format.

Signed could result to overflow in label length.

Change-Id: Ic1cae2c0df295127940fe1af74561690c0cddc30

1 files changed, 18 insertions, 16 deletions

diff --git a/src/libknot/zone/zone-tree.c b/src/libknot/zone/zone-tree.c
index 1f8cb1624..f20f9189c 100644
--- a/src/libknot/zone/zone-tree.c
+++ b/src/libknot/zone/zone-tree.c
@@ -27,7 +27,7 @@
 /* Non-API functions                                                          */
 /*----------------------------------------------------------------------------*/
 
-#define DNAME_LFT_MAXLEN 256 /* maximum lookup format length */
+#define DNAME_LFT_MAXLEN 255 /* maximum lookup format length */
 
 /*!
  * \brief Convert domain name from wire to lookup format.
@@ -50,14 +50,16 @@
  * \retval KNOT_ESPACE when not enough memory.
  * \retval KNOT_EINVAL on invalid parameters
  */
-static int dname_lf(char *dst, const knot_dname_t *src, size_t maxlen) {
-	if (!src || !dst) return KNOT_EINVAL;
-	if (src->size > maxlen) return KNOT_ESPACE;
-	*dst = src->size - 1;
-	if (*dst == 0) ++*dst; /* root special case */
+static int dname_lf(uint8_t *dst, const knot_dname_t *src, size_t maxlen) {
+	if (src->size > maxlen)
+		return KNOT_ESPACE;
+	*dst = (uint8_t)src->size;
+	/* need to save last \x00 for root dname */
+	if (*dst > 1)
+		*dst -= 1;
 	*++dst = '\0';
 	uint8_t* l = src->name;
-	uint8_t lstack[127];
+	uint8_t lstack[DNAME_LFT_MAXLEN];
 	uint8_t *sp = lstack;
 	while(*l != 0) { /* build label stack */
 		*sp++ = (l - src->name);
@@ -106,10 +108,10 @@ size_t knot_zone_tree_weight(knot_zone_tree_t* tree)
 int knot_zone_tree_insert(knot_zone_tree_t *tree, knot_node_t *node)
 {
 	assert(tree && node && node->owner);
-	char lf[DNAME_LFT_MAXLEN];
+	uint8_t lf[DNAME_LFT_MAXLEN];
 	dname_lf(lf, node->owner, sizeof(lf));
 
-	*hattrie_get(tree, lf+1, *lf) = node;
+	*hattrie_get(tree, (char*)lf+1, *lf) = node;
 	return KNOT_EOK;
 }
 
@@ -134,10 +136,10 @@ int knot_zone_tree_get(knot_zone_tree_t *tree, const knot_dname_t *owner,
 		return KNOT_EINVAL;
 	}
 
-	char lf[DNAME_LFT_MAXLEN];
+	uint8_t lf[DNAME_LFT_MAXLEN];
 	dname_lf(lf, owner, sizeof(lf));
 
-	value_t *val = hattrie_tryget(tree, lf+1, *lf);
+	value_t *val = hattrie_tryget(tree, (char*)lf+1, *lf);
 	if (val == NULL) {
 		*found = NULL;
 	} else {
@@ -179,11 +181,11 @@ int knot_zone_tree_get_less_or_equal(knot_zone_tree_t *tree,
 		return KNOT_EINVAL;
 	}
 
-	char lf[DNAME_LFT_MAXLEN];
+	uint8_t lf[DNAME_LFT_MAXLEN];
 	dname_lf(lf, owner, sizeof(lf));
 
 	value_t *fval = NULL;
-	int ret = hattrie_find_leq(tree, lf+1, *lf, &fval);
+	int ret = hattrie_find_leq(tree, (char*)lf+1, *lf, &fval);
 	if (fval) *found = (knot_node_t *)(*fval);
 	int exact_match = 0;
 	if (ret == 0) {
@@ -235,10 +237,10 @@ int knot_zone_tree_remove(knot_zone_tree_t *tree,
 		return KNOT_EINVAL;
 	}
 
-	char lf[DNAME_LFT_MAXLEN];
+	uint8_t lf[DNAME_LFT_MAXLEN];
 	dname_lf(lf, owner, sizeof(lf));
 
-	value_t *rval = hattrie_tryget(tree, lf+1, *lf);
+	value_t *rval = hattrie_tryget(tree, (char*)lf+1, *lf);
 	if (rval == NULL) {
 		return KNOT_ENOENT;
 	} else {
@@ -246,7 +248,7 @@ int knot_zone_tree_remove(knot_zone_tree_t *tree,
 	}
 
 
-	hattrie_del(tree, lf+1, *lf);
+	hattrie_del(tree, (char*)lf+1, *lf);
 	return KNOT_EOK;
 }