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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 00:53:35 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 00:53:35 +0000 |
commit | 69c6a41ffb878ef98c9378ed4b1634a404cfaa7f (patch) | |
tree | b2a4f704565d62fbb129ab9dc3b35977c50e6e7f /src/libdnssec/nsec/bitmap.c | |
parent | Initial commit. (diff) | |
download | knot-upstream.tar.xz knot-upstream.zip |
Adding upstream version 2.7.6.upstream/2.7.6upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | src/libdnssec/nsec/bitmap.c | 142 |
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..001613a --- /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 <http://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; + } +} |