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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/contrib/wire_ctx.h | |
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 '')
-rw-r--r-- | src/contrib/wire_ctx.h | 361 |
1 files changed, 361 insertions, 0 deletions
diff --git a/src/contrib/wire_ctx.h b/src/contrib/wire_ctx.h new file mode 100644 index 0000000..25ff143 --- /dev/null +++ b/src/contrib/wire_ctx.h @@ -0,0 +1,361 @@ +/* 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/>. + */ + +#pragma once + +#include <assert.h> +#include <stdbool.h> +#include <stddef.h> +#include <stdint.h> +#include <string.h> +#include <sys/types.h> + +#include "libknot/endian.h" +#include "libknot/errcode.h" + +/*! + * \brief Struct to keep the wire context. + */ +typedef struct wire_ctx { + size_t size; + uint8_t *wire; + uint8_t *position; + int error; + bool readonly; +} wire_ctx_t; + +/*! + * \brief Initialize wire context. + */ +static inline wire_ctx_t wire_ctx_init(uint8_t *data, size_t size) +{ + assert(data); + + wire_ctx_t result = { + .size = size, + .wire = data, + .position = data, + .error = KNOT_EOK, + .readonly = false + }; + + return result; +} + +/*! + * \brief Initialize read only wire context. + * + * \note No write is performed, and error is set to KNOT_EACCES. + * + */ +static inline wire_ctx_t wire_ctx_init_const(const uint8_t *data, size_t size) +{ + assert(data); + + wire_ctx_t result = wire_ctx_init((uint8_t *)data, size); + result.readonly = true; + + return result; +} + +/*! + * \brief Gets actual position. + * + * \return position from the begin. + */ +static inline size_t wire_ctx_offset(wire_ctx_t *ctx) +{ + assert(ctx); + + return ctx->position - ctx->wire; +} + +/*! + * \brief Set position offset from the begin. + * + * \param offset Wire offset (starts from 0). + * + * \note Noop if previous error. + */ +static inline void wire_ctx_set_offset(wire_ctx_t *ctx, size_t offset) +{ + assert(ctx); + + if (ctx->error != KNOT_EOK) { + return; + } + + if (offset > ctx->size) { + ctx->error = KNOT_ERANGE; + return; + } + + ctx->position = ctx->wire + offset; +} + +/*! + * \brief Gets available bytes. + * + * \return Number of bytes to end. + */ +static inline size_t wire_ctx_available(wire_ctx_t *ctx) +{ + assert(ctx); + + return ctx->size - wire_ctx_offset(ctx); +} + +/*! + * \brief Add offset to the current position. + * + * \note Noop if previous error. + */ +static inline void wire_ctx_skip(wire_ctx_t *ctx, ssize_t offset) +{ + assert(ctx); + + if (ctx->error != KNOT_EOK) { + return; + } + + // Check for out of scope skip. + if (offset >= 0) { + if (offset > wire_ctx_available(ctx)) { + ctx->error = KNOT_ERANGE; + return; + } + } else { + if (-offset > wire_ctx_offset(ctx)) { + ctx->error = KNOT_ERANGE; + return; + } + } + + ctx->position += offset; +} + +/*! + * \brief Check the context if reading is possible. + */ +static inline int wire_ctx_can_read(wire_ctx_t *ctx, size_t size) +{ + assert(ctx); + + if (ctx->error != KNOT_EOK) { + return ctx->error; + } + + if (wire_ctx_available(ctx) < size) { + return KNOT_EFEWDATA; + } + + return KNOT_EOK; +} + +/*! + * \brief Check the context if writing is possible. + */ +static inline int wire_ctx_can_write(wire_ctx_t *ctx, size_t size) +{ + assert(ctx); + + if (ctx->error != KNOT_EOK) { + return ctx->error; + } + + if (ctx->readonly) { + return KNOT_EACCES; + } + + if (wire_ctx_available(ctx) < size) { + return KNOT_ESPACE; + } + + return KNOT_EOK; +} + + +static inline void wire_ctx_read(wire_ctx_t *ctx, void *data, size_t size) +{ + assert(ctx); + assert(data); + + if (ctx->error != KNOT_EOK) { + /* Avoid leaving data uninitialized. */ + memset(data, 0, size); + return; + } + + int ret = wire_ctx_can_read(ctx, size); + if (ret != KNOT_EOK) { + ctx->error = ret; + memset(data, 0, size); + return; + } + + memcpy(data, ctx->position, size); + ctx->position += size; +} + +static inline uint8_t wire_ctx_read_u8(wire_ctx_t *ctx) +{ + uint8_t result; + wire_ctx_read(ctx, &result, sizeof(result)); + + return result; +} + +static inline uint16_t wire_ctx_read_u16(wire_ctx_t *ctx) +{ + uint16_t result; + wire_ctx_read(ctx, &result, sizeof(result)); + + return be16toh(result); +} + +static inline uint32_t wire_ctx_read_u32(wire_ctx_t *ctx) +{ + uint32_t result; + wire_ctx_read(ctx, &result, sizeof(result)); + + return be32toh(result); +} + +static inline uint64_t wire_ctx_read_u48(wire_ctx_t *ctx) +{ + /* This case is slightly tricky. */ + uint64_t result = 0; + wire_ctx_read(ctx, (uint8_t *)&result + 1, 6); + + return be64toh(result) >> 8; +} + +static inline uint64_t wire_ctx_read_u64(wire_ctx_t *ctx) +{ + uint64_t result; + wire_ctx_read(ctx, &result, sizeof(result)); + + return be64toh(result); +} + + +static inline void wire_ctx_write(wire_ctx_t *ctx, const void *data, size_t size) +{ + assert(ctx); + + if (ctx->error != KNOT_EOK) { + return; + } + + if (size == 0) { + return; + } + + assert(data); + + int ret = wire_ctx_can_write(ctx, size); + if (ret != KNOT_EOK) { + ctx->error = ret; + return; + } + + memcpy(ctx->position, data, size); + ctx->position += size; +} + +static inline void wire_ctx_write_u8(wire_ctx_t *ctx, uint8_t value) +{ + wire_ctx_write(ctx, &value, sizeof(value)); +} + +static inline void wire_ctx_write_u16(wire_ctx_t *ctx, uint16_t value) +{ + uint16_t beval = htobe16(value); + wire_ctx_write(ctx, &beval, sizeof(beval)); +} + +static inline void wire_ctx_write_u32(wire_ctx_t *ctx, uint32_t value) +{ + uint32_t beval = htobe32(value); + wire_ctx_write(ctx, &beval, sizeof(beval)); +} + +static inline void wire_ctx_write_u48(wire_ctx_t *ctx, uint64_t value) +{ + /* This case is slightly tricky. */ + uint64_t swapped = htobe64(value << 8); + wire_ctx_write(ctx, (uint8_t *)&swapped + 1, 6); +} + +static inline void wire_ctx_write_u64(wire_ctx_t *ctx, uint64_t value) +{ + uint64_t beval = htobe64(value); + wire_ctx_write(ctx, &beval, sizeof(beval)); +} + + +static inline void wire_ctx_memset(wire_ctx_t *dst, int value, size_t size) +{ + assert(dst); + + if (dst->error != KNOT_EOK) { + return; + } + + if (size == 0) { + return; + } + + int ret = wire_ctx_can_write(dst, size); + if (ret != KNOT_EOK) { + dst->error = ret; + return; + } + + memset(dst->position, value, size); + dst->position += size; +} + +static inline void wire_ctx_clear(wire_ctx_t *ctx, size_t size) +{ + wire_ctx_memset(ctx, 0, size); +} + +static inline void wire_ctx_copy(wire_ctx_t *dst, wire_ctx_t *src, size_t size) +{ + assert(dst); + assert(src); + + if (size == 0 || dst->error != KNOT_EOK) { + return; + } + + if (wire_ctx_can_read(src, size) != KNOT_EOK) { + dst->error = KNOT_EFEWDATA; + return; + } + + int ret = wire_ctx_can_write(dst, size); + if (ret != KNOT_EOK) { + dst->error = ret; + return; + } + + memcpy(dst->position, src->position, size); + dst->position += size; + src->position += size; +} + |