return ds;
}
+/* From RFC3845:
+ *
+ * 2.1.2. The List of Type Bit Map(s) Field
+ *
+ * The RR type space is split into 256 window blocks, each representing
+ * the low-order 8 bits of the 16-bit RR type space. Each block that
+ * has at least one active RR type is encoded using a single octet
+ * window number (from 0 to 255), a single octet bitmap length (from 1
+ * to 32) indicating the number of octets used for the window block's
+ * bitmap, and up to 32 octets (256 bits) of bitmap.
+ *
+ * Window blocks are present in the NSEC RR RDATA in increasing
+ * numerical order.
+ *
+ * "|" denotes concatenation
+ *
+ * Type Bit Map(s) Field = ( Window Block # | Bitmap Length | Bitmap ) +
+ *
+ * <cut>
+ *
+ * Blocks with no types present MUST NOT be included. Trailing zero
+ * octets in the bitmap MUST be omitted. The length of each block's
+ * bitmap is determined by the type code with the largest numerical
+ * value within that block, among the set of RR types present at the
+ * NSEC RR's owner name. Trailing zero octets not specified MUST be
+ * interpreted as zero octets.
+ */
ldns_rdf *
ldns_dnssec_create_nsec_bitmap(ldns_rr_type rr_type_list[],
size_t size,
ldns_rr_type nsec_type)
{
- size_t i;
- uint8_t *bitmap;
- uint16_t bm_len = 0;
- uint16_t i_type;
- ldns_rdf *bitmap_rdf;
+ uint8_t window; /* most significant octet of type */
+ uint8_t subtype; /* least significant octet of type */
+ uint16_t windows[256] /* Max subtype per window */
+#ifndef S_SPLINT_S
+ = { 0 }
+#endif
+ ;
+ ldns_rr_type* d; /* used to traverse rr_type_list*/
+ size_t i; /* used to traverse windows array */
- uint8_t *data = NULL;
- uint8_t cur_data[32];
- uint8_t cur_window = 0;
- uint8_t cur_window_max = 0;
- uint16_t cur_data_size = 0;
+ size_t sz; /* size needed for type bitmap rdf */
+ uint8_t* data = NULL; /* rdf data */
+ uint8_t* dptr; /* used to itraverse rdf data */
+ ldns_rdf* rdf; /* bitmap rdf to return */
if (nsec_type != LDNS_RR_TYPE_NSEC &&
nsec_type != LDNS_RR_TYPE_NSEC3) {
return NULL;
}
- i_type = 0;
- for (i = 0; i < size; i++) {
- if (i_type < rr_type_list[i])
- i_type = rr_type_list[i];
- }
- if (i_type < nsec_type) {
- i_type = nsec_type;
- }
-
- bm_len = i_type / 8 + 2;
- bitmap = LDNS_XMALLOC(uint8_t, bm_len);
- if(!bitmap) return NULL;
- for (i = 0; i < bm_len; i++) {
- bitmap[i] = 0;
- }
-
- for (i = 0; i < size; i++) {
- i_type = rr_type_list[i];
- ldns_set_bit(bitmap + (int) i_type / 8,
- (int) (7 - (i_type % 8)),
- true);
- }
-
- /* fold it into windows TODO: can this be done directly? */
- memset(cur_data, 0, 32);
- for (i = 0; i < bm_len; i++) {
- if (i / 32 > cur_window) {
- /* check, copy, new */
- if (cur_window_max > 0) {
- /* this window has stuff, add it */
- data = LDNS_XREALLOC(data,
- uint8_t,
- cur_data_size + cur_window_max + 3);
- if(!data) {
- LDNS_FREE(bitmap);
- return NULL;
- }
- data[cur_data_size] = cur_window;
- data[cur_data_size + 1] = cur_window_max + 1;
- memcpy(data + cur_data_size + 2,
- cur_data,
- cur_window_max+1);
- cur_data_size += cur_window_max + 3;
- }
- cur_window++;
- cur_window_max = 0;
- memset(cur_data, 0, 32);
+ /* The NSEC type itself is in the bitmap always
+ */
+ windows[nsec_type >> 8] = nsec_type & 0xff;
+
+ /* Which other windows need to be in the bitmap rdf?
+ */
+ for (d = rr_type_list; d < rr_type_list + size; d++) {
+ window = *d >> 8;
+ subtype = *d & 0xff;
+ if (windows[window] < subtype) {
+ windows[window] = subtype;
}
- cur_data[i%32] = bitmap[i];
- if (bitmap[i] > 0) {
- cur_window_max = i%32;
+ }
+
+ /* How much space do we need in the rdf for those windows?
+ */
+ sz = 0;
+ for (i = 0; i < 256; i++) {
+ if (windows[i]) {
+ sz += windows[i] / 8 + 3;
}
}
- if (cur_window_max > 0 || cur_data[0] != 0) {
- /* this window has stuff, add it */
- data = LDNS_XREALLOC(data,
- uint8_t,
- cur_data_size + cur_window_max + 3);
- if(!data) {
- LDNS_FREE(bitmap);
- return NULL;
- }
- data[cur_data_size] = cur_window;
- data[cur_data_size + 1] = cur_window_max + 1;
- memcpy(data + cur_data_size + 2, cur_data, cur_window_max+1);
- cur_data_size += cur_window_max + 3;
+ if (sz > 0) {
+ /* Format rdf data according RFC3845 Section 2.1.2 (see above)
+ */
+ dptr = data = LDNS_XMALLOC(uint8_t, sz);
+ if (!data) {
+ return NULL;
+ }
+ for (i = 0; i < 256; i++) {
+ if (windows[i]) {
+ *dptr++ = (uint8_t)i;
+ *dptr++ = (uint8_t)(windows[i] / 8 + 1);
+
+ /* Now let windows[i] index the bitmap
+ * within data
+ */
+ windows[i] = (uint16_t)(dptr - data);
+
+ dptr += dptr[-1];
+ }
+ }
}
- bitmap_rdf = ldns_rdf_new_frm_data(LDNS_RDF_TYPE_NSEC,
- cur_data_size,
- data);
- LDNS_FREE(bitmap);
- LDNS_FREE(data);
+ /* Set the bits?
+ */
+ subtype = nsec_type & 0xff;
+ data[windows[nsec_type >> 8] + subtype/8] |= (0x80 >> (subtype % 8));
+ for (d = rr_type_list; d < rr_type_list + size; d++) {
+ subtype = *d & 0xff;
+ data[windows[*d >> 8] + subtype/8] |= (0x80 >> (subtype % 8));
+ }
- return bitmap_rdf;
+ /* Allocate and return rdf structure for the data
+ */
+ rdf = ldns_rdf_new(LDNS_RDF_TYPE_BITMAP, sz, data);
+ if (!rdf) {
+ LDNS_FREE(data);
+ return NULL;
+ }
+ return rdf;
}
int
if (dptr[0] == window && subtype / 8 < dptr[1] &&
dptr + dptr[1] + 2 <= dend) {
- return dptr[2 + subtype / 8] & (1 << (subtype % 8));
+ return dptr[2 + subtype / 8] & (0x80 >> (subtype % 8));
}
dptr += dptr[1] + 2; /* next window */
}
if (dptr[0] == window && subtype / 8 < dptr[1] &&
dptr + dptr[1] + 2 <= dend) {
- dptr[2 + subtype / 8] |= (1 << (subtype % 8));
+ dptr[2 + subtype / 8] |= (0x80 >> (subtype % 8));
return LDNS_STATUS_OK;
}
dptr += dptr[1] + 2; /* next window */
if (dptr[0] == window && subtype / 8 < dptr[1] &&
dptr + dptr[1] + 2 <= dend) {
- dptr[2 + subtype / 8] &= ~(1 << (subtype % 8));
+ dptr[2 + subtype / 8] &= ~(0x80 >> (subtype % 8));
return LDNS_STATUS_OK;
}
dptr += dptr[1] + 2; /* next window */
projects / thirdparty / ldns.git / commitdiff
