/**
* 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;
}
/**
* Create new domain name.
*
*/
dname_type*
dname_create(region_type* r, const char* str)
{
uint8_t wire[DNAME_MAXLEN];
uint8_t label_offsets[DNAME_MAXLEN];
uint8_t label_count = 0;
size_t size = 0;
const uint8_t* label = wire;
dname_type *dname;
ssize_t i;
assert(r);
assert(str);
if (!dname_str2wire(wire, str)) {
fprintf(stderr, "[%s] error: parse dname %s failed", logstr, str);
return NULL;
}
while (1) {
if (label_is_pointer(label)) {
return NULL;
}
label_offsets[label_count] = (uint8_t) (label - wire);
++label_count;
size += label_length(label) + 1;
if (label_is_root(label)) {
break;
}
label = label_next(label);
}
if (size > DNAME_MAXLEN) {
return NULL;
}
assert(label_count <= DNAME_MAXLEN / 2 + 1);
/* reverse label offsets. */
/* reverse label offsets. */
for (i = 0; i < label_count / 2; ++i) {
uint8_t tmp = label_offsets[i];
label_offsets[i] = label_offsets[label_count - i - 1];
label_offsets[label_count - i - 1] = tmp;
}
dname = (dname_type *) region_alloc(r, (sizeof(dname_type)
+ (label_count + size) * sizeof(uint8_t)));
dname->size = size;
dname->label_count = label_count;
memcpy((uint8_t *) dname_label_offsets(dname), label_offsets,
label_count * sizeof(uint8_t));
memcpy((uint8_t *) dname_name(dname), wire, size * sizeof(uint8_t));
return dname;
}
const dname_type *
dname_make(region_type *region, const uint8_t *name, int normalize)
{
size_t name_size = 0;
uint8_t label_offsets[MAXDOMAINLEN];
uint8_t label_count = 0;
const uint8_t *label = name;
dname_type *result;
ssize_t i;
assert(name);
while (1) {
if (label_is_pointer(label))
return NULL;
label_offsets[label_count] = (uint8_t) (label - name);
++label_count;
name_size += label_length(label) + 1;
if (label_is_root(label))
break;
label = label_next(label);
}
if (name_size > MAXDOMAINLEN)
return NULL;
assert(label_count <= MAXDOMAINLEN / 2 + 1);
/* Reverse label offsets. */
for (i = 0; i < label_count / 2; ++i) {
uint8_t tmp = label_offsets[i];
label_offsets[i] = label_offsets[label_count - i - 1];
label_offsets[label_count - i - 1] = tmp;
}
result = (dname_type *) region_alloc(
region,
(sizeof(dname_type)
+ (label_count + name_size) * sizeof(uint8_t)));
result->name_size = name_size;
result->label_count = label_count;
memcpy((uint8_t *) dname_label_offsets(result),
label_offsets,
label_count * sizeof(uint8_t));
if (normalize) {
uint8_t *dst = (uint8_t *) dname_name(result);
const uint8_t *src = name;
while (!label_is_root(src)) {
ssize_t len = label_length(src);
*dst++ = *src++;
for (i = 0; i < len; ++i) {
*dst++ = DNAME_NORMALIZE(*src++);
}
}
*dst = *src;
} else {
memcpy((uint8_t *) dname_name(result),
name,
name_size * sizeof(uint8_t));
}
return result;
}
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;
}
