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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 15:24:08 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 15:24:08 +0000
commitf449f278dd3c70e479a035f50a9bb817a9b433ba (patch)
tree8ca2bfb785dda9bb4d573acdf9b42aea9cd51383 /src/libdnssec/nsec/bitmap.c
parentInitial commit. (diff)
downloadknot-f449f278dd3c70e479a035f50a9bb817a9b433ba.tar.xz
knot-f449f278dd3c70e479a035f50a9bb817a9b433ba.zip
Adding upstream version 3.2.6.upstream/3.2.6upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/libdnssec/nsec/bitmap.c')
-rw-r--r--src/libdnssec/nsec/bitmap.c142
1 files changed, 142 insertions, 0 deletions
diff --git a/src/libdnssec/nsec/bitmap.c b/src/libdnssec/nsec/bitmap.c
new file mode 100644
index 0000000..05f8cfa
--- /dev/null
+++ b/src/libdnssec/nsec/bitmap.c
@@ -0,0 +1,142 @@
+/* Copyright (C) 2018 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <limits.h>
+#include <stdint.h>
+#include <string.h>
+
+#include "libdnssec/nsec.h"
+#include "libdnssec/shared/shared.h"
+
+#define BITMAP_WINDOW_SIZE 256
+#define BITMAP_WINDOW_BYTES (BITMAP_WINDOW_SIZE/CHAR_BIT)
+#define BITMAP_WINDOW_COUNT 256
+
+/*!
+ * One window of an NSEC bitmap.
+ */
+typedef struct window {
+ uint8_t used;
+ uint8_t data[BITMAP_WINDOW_BYTES];
+} window_t;
+
+struct dnssec_nsec_bitmap {
+ int used;
+ window_t windows[BITMAP_WINDOW_COUNT];
+};
+
+/* -- public API ----------------------------------------------------------- */
+
+/*!
+ * Allocate new bit map encoding context.
+ */
+_public_
+dnssec_nsec_bitmap_t *dnssec_nsec_bitmap_new(void)
+{
+ dnssec_nsec_bitmap_t *bitmap = malloc(sizeof(*bitmap));
+ if (!bitmap) {
+ return NULL;
+ }
+
+ dnssec_nsec_bitmap_clear(bitmap);
+
+ return bitmap;
+}
+
+/*!
+ * Clear existing bit map encoding context.
+ */
+_public_
+void dnssec_nsec_bitmap_clear(dnssec_nsec_bitmap_t *bitmap)
+{
+ clear_struct(bitmap);
+}
+
+/*!
+ * Free bit map encoding context.
+ */
+_public_
+void dnssec_nsec_bitmap_free(dnssec_nsec_bitmap_t *bitmap)
+{
+ free(bitmap);
+}
+
+/*!
+ * Add one RR type into the bitmap.
+ */
+_public_
+void dnssec_nsec_bitmap_add(dnssec_nsec_bitmap_t *bitmap, uint16_t type)
+{
+ int win = type / BITMAP_WINDOW_SIZE;
+ int bit = type % BITMAP_WINDOW_SIZE;
+
+ if (bitmap->used <= win) {
+ bitmap->used = win + 1;
+ }
+
+ int win_byte = bit / CHAR_BIT;
+ int win_bit = bit % CHAR_BIT;
+
+ window_t *window = &bitmap->windows[win];
+ window->data[win_byte] |= 0x80 >> win_bit;
+ if (window->used <= win_byte) {
+ window->used = win_byte + 1;
+ }
+}
+
+/*!
+ * Compute the size of the encoded bitmap.
+ */
+_public_
+size_t dnssec_nsec_bitmap_size(const dnssec_nsec_bitmap_t *bitmap)
+{
+ size_t result = 0;
+
+ for (int i = 0; i < bitmap->used; i++) {
+ int used = bitmap->windows[i].used;
+ if (used == 0) {
+ continue;
+ }
+
+ result += 2 + used; // windows number, window size, data
+ }
+
+ return result;
+}
+
+/*!
+ * Write encoded bitmap into the given buffer.
+ */
+_public_
+void dnssec_nsec_bitmap_write(const dnssec_nsec_bitmap_t *bitmap, uint8_t *output)
+{
+ uint8_t *write_ptr = output;
+ for (int win = 0; win < bitmap->used; win++) {
+ int used = bitmap->windows[win].used;
+ if (used == 0) {
+ continue;
+ }
+
+ *write_ptr = (uint8_t)win;
+ write_ptr += 1;
+
+ *write_ptr = (uint8_t)used;
+ write_ptr += 1;
+
+ memmove(write_ptr, bitmap->windows[win].data, used);
+ write_ptr += used;
+ }
+}