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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/shared/dname.c | |
parent | Initial commit. (diff) | |
download | knot-upstream/2.7.6.tar.xz knot-upstream/2.7.6.zip |
Adding upstream version 2.7.6.upstream/2.7.6upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/libdnssec/shared/dname.c')
-rw-r--r-- | src/libdnssec/shared/dname.c | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/src/libdnssec/shared/dname.c b/src/libdnssec/shared/dname.c new file mode 100644 index 0000000..51605f6 --- /dev/null +++ b/src/libdnssec/shared/dname.c @@ -0,0 +1,165 @@ +/* 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 <assert.h> +#include <stdbool.h> +#include <stdlib.h> +#include <stdint.h> +#include <string.h> + +#include "libdnssec/shared/dname.h" +#include "libdnssec/shared/shared.h" +#include "contrib/tolower.h" + +/*! + * Get length of a domain name in wire format. + */ +size_t dname_length(const uint8_t *dname) +{ + if (!dname) { + return 0; + } + + const uint8_t *scan = dname; + uint8_t label_len; + do { + label_len = *scan; + scan += 1 + label_len; + } while (label_len > 0); + assert(scan > dname); + + size_t length = scan - dname; + if (length > DNAME_MAX_LENGTH) { + return 0; + } + + return length; +} + +/*! + * Copy domain name in wire format. + */ +uint8_t *dname_copy(const uint8_t *dname) +{ + if (!dname) { + return NULL; + } + + size_t length = dname_length(dname); + if (length == 0) { + return NULL; + } + + uint8_t *copy = malloc(length); + if (!copy) { + return NULL; + } + + memmove(copy, dname, length); + return copy; +} + +/*! + * Normalize dname label in-place. + * + * \return Number of processed bytes, 0 if we encounter the last label. + */ +static uint8_t normalize_label(uint8_t *label) +{ + assert(label); + + uint8_t len = *label; + if (len == 0 || len > DNAME_MAX_LABEL_LENGTH) { + return 0; + } + + for (uint8_t *scan = label + 1, *end = scan + len; scan < end; scan++) { + *scan = knot_tolower(*scan); + } + + return len + 1; +} + +/*! + * Normalize domain name in wire format. + */ +void dname_normalize(uint8_t *dname) +{ + if (!dname) { + return; + } + + uint8_t read, *scan = dname; + do { + read = normalize_label(scan); + scan += read; + } while (read > 0); +} + +/*! + * Compare dname labels case insensitively. + */ +static int label_casecmp(const uint8_t *a, const uint8_t *b, uint8_t len) +{ + assert(a); + assert(b); + + for (const uint8_t *a_end = a + len; a < a_end; a++, b++) { + if (knot_tolower(*a) != knot_tolower(*b)) { + return false; + } + } + + return true; +} + +/*! + * Check if two dnames are equal. + */ +bool dname_equal(const uint8_t *one, const uint8_t *two) +{ + if (!one || !two) { + return false; + } + + const uint8_t *scan_one = one; + const uint8_t *scan_two = two; + + for (;;) { + if (*scan_one != *scan_two) { + return false; + } + + uint8_t len = *scan_one; + if (len == 0) { + return true; + } else if (len > DNAME_MAX_LABEL_LENGTH) { + return false; + } + + scan_one += 1; + scan_two += 1; + + if (!label_casecmp(scan_one, scan_two, len)) { + return false; + } + + scan_one += len; + scan_two += len; + } + + return true; +} |