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/* SPDX-License-Identifier: GPL-3.0-or-later
* Copyright © 2022 The TokTok team.
*/
#include "bin_unpack.h"
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include "../third_party/cmp/cmp.h"
#include "ccompat.h"
struct Bin_Unpack {
const uint8_t *bytes;
uint32_t bytes_size;
cmp_ctx_t ctx;
};
non_null()
static bool buf_reader(cmp_ctx_t *ctx, void *data, size_t limit)
{
Bin_Unpack *reader = (Bin_Unpack *)ctx->buf;
assert(reader != nullptr && reader->bytes != nullptr);
if (limit > reader->bytes_size) {
return false;
}
memcpy(data, reader->bytes, limit);
reader->bytes += limit;
reader->bytes_size -= limit;
return true;
}
non_null()
static bool buf_skipper(cmp_ctx_t *ctx, size_t limit)
{
Bin_Unpack *reader = (Bin_Unpack *)ctx->buf;
assert(reader != nullptr && reader->bytes != nullptr);
if (limit > reader->bytes_size) {
return false;
}
reader->bytes += limit;
reader->bytes_size -= limit;
return true;
}
non_null()
static size_t null_writer(cmp_ctx_t *ctx, const void *data, size_t count)
{
assert(count == 0);
return 0;
}
Bin_Unpack *bin_unpack_new(const uint8_t *buf, uint32_t buf_size)
{
Bin_Unpack *bu = (Bin_Unpack *)calloc(1, sizeof(Bin_Unpack));
if (bu == nullptr) {
return nullptr;
}
bu->bytes = buf;
bu->bytes_size = buf_size;
cmp_init(&bu->ctx, bu, buf_reader, buf_skipper, null_writer);
return bu;
}
void bin_unpack_free(Bin_Unpack *bu)
{
free(bu);
}
bool bin_unpack_array(Bin_Unpack *bu, uint32_t *size)
{
return cmp_read_array(&bu->ctx, size) && *size <= bu->bytes_size;
}
bool bin_unpack_array_fixed(Bin_Unpack *bu, uint32_t required_size)
{
uint32_t size;
return cmp_read_array(&bu->ctx, &size) && size == required_size;
}
bool bin_unpack_bool(Bin_Unpack *bu, bool *val)
{
return cmp_read_bool(&bu->ctx, val);
}
bool bin_unpack_u08(Bin_Unpack *bu, uint8_t *val)
{
return cmp_read_uchar(&bu->ctx, val);
}
bool bin_unpack_u16(Bin_Unpack *bu, uint16_t *val)
{
return cmp_read_ushort(&bu->ctx, val);
}
bool bin_unpack_u32(Bin_Unpack *bu, uint32_t *val)
{
return cmp_read_uint(&bu->ctx, val);
}
bool bin_unpack_u64(Bin_Unpack *bu, uint64_t *val)
{
return cmp_read_ulong(&bu->ctx, val);
}
bool bin_unpack_bin(Bin_Unpack *bu, uint8_t **data_ptr, uint32_t *data_length_ptr)
{
uint32_t bin_size;
if (!bin_unpack_bin_size(bu, &bin_size) || bin_size > bu->bytes_size) {
// There aren't as many bytes as this bin claims to want to allocate.
return false;
}
uint8_t *const data = (uint8_t *)malloc(bin_size);
if (!bin_unpack_bin_b(bu, data, bin_size)) {
free(data);
return false;
}
*data_ptr = data;
*data_length_ptr = bin_size;
return true;
}
bool bin_unpack_bin_fixed(Bin_Unpack *bu, uint8_t *data, uint32_t data_length)
{
uint32_t bin_size;
if (!bin_unpack_bin_size(bu, &bin_size) || bin_size != data_length) {
return false;
}
return bin_unpack_bin_b(bu, data, bin_size);
}
bool bin_unpack_bin_size(Bin_Unpack *bu, uint32_t *size)
{
return cmp_read_bin_size(&bu->ctx, size);
}
bool bin_unpack_u08_b(Bin_Unpack *bu, uint8_t *val)
{
return bin_unpack_bin_b(bu, val, 1);
}
bool bin_unpack_u16_b(Bin_Unpack *bu, uint16_t *val)
{
uint8_t hi = 0;
uint8_t lo = 0;
if (!(bin_unpack_u08_b(bu, &hi)
&& bin_unpack_u08_b(bu, &lo))) {
return false;
}
*val = ((uint16_t)hi << 8) | lo;
return true;
}
bool bin_unpack_u32_b(Bin_Unpack *bu, uint32_t *val)
{
uint16_t hi = 0;
uint16_t lo = 0;
if (!(bin_unpack_u16_b(bu, &hi)
&& bin_unpack_u16_b(bu, &lo))) {
return false;
}
*val = ((uint32_t)hi << 16) | lo;
return true;
}
bool bin_unpack_u64_b(Bin_Unpack *bu, uint64_t *val)
{
uint32_t hi = 0;
uint32_t lo = 0;
if (!(bin_unpack_u32_b(bu, &hi)
&& bin_unpack_u32_b(bu, &lo))) {
return false;
}
*val = ((uint64_t)hi << 32) | lo;
return true;
}
bool bin_unpack_bin_b(Bin_Unpack *bu, uint8_t *data, uint32_t length)
{
return bu->ctx.read(&bu->ctx, data, length);
}
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