Merge branch 'fix_zero_label_compression' into 'master'

libknot: don't compress zero label dname

See merge request !414

src/libknot/dname.h

@@ -94,9 +94,6 @@ knot_dname_t *knot_dname_copy_part(const knot_dname_t *name, unsigned len,
  * \param maxlen Maximum wire length.
  *
  * \return number of bytes written
- *
- * \todo For most use cases this could be replaced by counting the length
- *       and simple memcpy.
  */
 int knot_dname_to_wire(uint8_t *dst, const knot_dname_t *src, size_t maxlen);
 

src/libknot/packet/compr.c

@@ -55,18 +55,18 @@ _public_
 int knot_compr_put_dname(const knot_dname_t *dname, uint8_t *dst, uint16_t max,
                          knot_compr_t *compr)
 {
-	/* Write uncompressible names directly. */
 	if (dname == NULL || dst == NULL) {
 		return KNOT_EINVAL;
 	}
+
+	/* Write uncompressible names directly (zero label dname). */
 	if (compr == NULL || *dname == '\0') {
 		return knot_dname_to_wire(dst, dname, max);
 	}
 
+	/* Get number of labels (should not be a zero label dname). */
 	int name_labels = knot_dname_labels(dname, NULL);
-	if (name_labels < 0) {
-		return name_labels;
-	}
+	assert(name_labels > 0);
 
 	/* Suffix must not be longer than whole name. */
 	const knot_dname_t *suffix = compr->wire + compr->suffix.pos;

src/libknot/packet/rrset-wire.c

@@ -284,7 +284,12 @@ static int write_owner(const knot_rrset_t *rrset, uint8_t **dst, size_t *dst_ava
 	assert(dst && *dst);
 	assert(dst_avail);
 
-	uint16_t owner_pointer = compr_get_ptr(compr, KNOT_COMPR_HINT_OWNER);
+	/* Check for zero label owner (don't compress). */
+
+	uint16_t owner_pointer = 0;
+	if (*rrset->owner != '\0') {
+		owner_pointer = compr_get_ptr(compr, KNOT_COMPR_HINT_OWNER);
+	}
 
 	/* Check size */
 
@@ -393,7 +398,6 @@ static int compress_rdata_dname(const uint8_t **src, size_t *src_avail,
 	int written = knot_compr_put_dname(dname, *dst, dname_max(*dst_avail),
 	                                   put_compr);
 	if (written < 0) {
-		assert(written == KNOT_ESPACE);
 		return written;
 	}
 
@@ -514,9 +518,7 @@ int knot_rrset_to_wire(const knot_rrset_t *rrset, uint8_t *wire, uint16_t max_si
 		}
 	}
 
-	size_t written = write - wire;
-
-	return written;
+	return write - wire;
 }
 
 /*- RRSet from wire ---------------------------------------------------------*/
@@ -644,7 +646,7 @@ static int parse_rdata(const uint8_t *pkt_wire, size_t *pos, size_t pkt_size,
 	if (buffer_size < 0) {
 		return buffer_size;
 	}
-	
+
 	if (buffer_size > MAX_RDLENGTH) {
 		/* DNAME compression caused RDATA overflow. */
 		return KNOT_EMALF;
@@ -680,7 +682,7 @@ static int parse_rdata(const uint8_t *pkt_wire, size_t *pos, size_t pkt_size,
 		knot_rdataset_unreserve(rrs, mm);
 		return ret;
 	}
-	
+
 	/* Update position pointer. */
 	*pos += rdlength;