int
label_compare(const uint8_t *left, const uint8_t *right)
{
int left_length;
int right_length;
size_t size;
int result;
assert(left);
assert(right);
assert(label_is_normal(left));
assert(label_is_normal(right));
left_length = label_length(left);
right_length = label_length(right);
size = left_length < right_length ? left_length : right_length;
result = memcmp(label_data(left), label_data(right), size);
if (result) {
return result;
} else {
return (int) left_length - (int) right_length;
}
}
/**
* Length of label.
*
*/
uint8_t
label_length(const uint8_t* label)
{
assert(label);
assert(label_is_normal(label));
return label[0];
}
/**
* Get the next label.
*
*/
const uint8_t*
label_next(const uint8_t* label)
{
assert(label);
assert(label_is_normal(label));
assert(!label_is_root(label));
return label + label_length(label) + 1;
}
int
dname_make_wire_from_packet(uint8_t *buf, buffer_type *packet,
int allow_pointers)
{
int done = 0;
uint8_t visited[(MAX_PACKET_SIZE+7)/8];
size_t dname_length = 0;
const uint8_t *label;
ssize_t mark = -1;
memset(visited, 0, (buffer_limit(packet)+7)/8);
while (!done) {
if (!buffer_available(packet, 1)) {
/* error("dname out of bounds"); */
return 0;
}
if (get_bit(visited, buffer_position(packet))) {
/* error("dname loops"); */
return 0;
}
set_bit(visited, buffer_position(packet));
label = buffer_current(packet);
if (label_is_pointer(label)) {
size_t pointer;
if (!allow_pointers) {
return 0;
}
if (!buffer_available(packet, 2)) {
/* error("dname pointer out of bounds"); */
return 0;
}
pointer = label_pointer_location(label);
if (pointer >= buffer_limit(packet)) {
/* error("dname pointer points outside packet"); */
return 0;
}
buffer_skip(packet, 2);
if (mark == -1) {
mark = buffer_position(packet);
}
buffer_set_position(packet, pointer);
} else if (label_is_normal(label)) {
size_t length = label_length(label) + 1;
done = label_is_root(label);
if (!buffer_available(packet, length)) {
/* error("dname label out of bounds"); */
return 0;
}
if (dname_length + length >= MAXDOMAINLEN+1) {
/* error("dname too large"); */
return 0;
}
buffer_read(packet, buf + dname_length, length);
dname_length += length;
} else {
/* error("bad label type"); */
return 0;
}
}
if (mark != -1) {
buffer_set_position(packet, mark);
}
return dname_length;
}
