improve 'next-label' algorithm in ldns-walk

Rather than adding \000 to an existing label, add a new label "\000." to the start of the domain name, to find the closes next possible domain name.

diff --git a/examples/ldns-walk.c b/examples/ldns-walk.c
index 3710098adb76c0a46e23a9dfc748e765bff9877b..f320b99d60000fcd44855bf64f6316e6dfad2140 100644 (file)
--- a/examples/ldns-walk.c
+++ b/examples/ldns-walk.c
@@ -38,24 +38,22 @@ create_dname_plus_1(ldns_rdf *dname)
        size_t i;
        
        ldns_dname2canonical(dname);
-       labellen = ldns_rdf_data(dname)[0];
        if (verbosity >= 3) {
                 printf("Create +e for ");
                 ldns_rdf_print(stdout, dname);
                 printf("\n");
        }
-       if (labellen < 63) {
-               wire = malloc(ldns_rdf_size(dname) + 1);
+       if (ldns_rdf_size(dname) < LDNS_MAX_DOMAINLEN) {
+               wire = malloc(ldns_rdf_size(dname) + 2);
                if (!wire) {
                        fprintf(stderr, "Malloc error: out of memory?\n");
                        exit(127);
                }
-               wire[0] = labellen + 1;
-               memcpy(&wire[1], ldns_rdf_data(dname) + 1, labellen);
-               memcpy(&wire[labellen+1], ldns_rdf_data(dname) + labellen, ldns_rdf_size(dname) - labellen);
-               wire[labellen+1] = (uint8_t) '\000';
+               wire[0] = (uint8_t) 1;
+               wire[1] = (uint8_t) '\000';
+               memcpy(&wire[2], ldns_rdf_data(dname), ldns_rdf_size(dname));
                pos = 0;
-               status = ldns_wire2dname(&newdname, wire, ldns_rdf_size(dname) + 1, &pos);
+               status = ldns_wire2dname(&newdname, wire, ldns_rdf_size(dname) + 2, &pos);
                free(wire);
        } else {
                wire = malloc(ldns_rdf_size(dname));
@@ -63,6 +61,7 @@ create_dname_plus_1(ldns_rdf *dname)
                        fprintf(stderr, "Malloc error: out of memory?\n");
                        exit(127);
                }
+               labellen = ldns_rdf_data(dname)[0];
                wire[0] = labellen;
                memcpy(&wire[1], ldns_rdf_data(dname) + 1, labellen);
                memcpy(&wire[labellen], ldns_rdf_data(dname) + labellen, ldns_rdf_size(dname) - labellen);