| /* Copyright (c) 2011 The Chromium OS Authors. All rights reserved. |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| /* Helper functions/wrappers for memory allocations, manipulation and |
| * comparison. |
| */ |
| |
| #ifndef VBOOT_FIRMWARE_LIB_UTILITY_H_ |
| #define VBOOT_FIRMWARE_LIB_UTILITY_H_ |
| |
| #include "sysincludes.h" |
| |
| /* Track remaining data to be read in a buffer. */ |
| typedef struct MemcpyState { |
| uint8_t* remaining_buf; |
| uint64_t remaining_len; /* Remaining length of the buffer. */ |
| uint8_t overrun; /* Flag set to 1 when an overrun occurs. */ |
| } MemcpyState; |
| |
| /* Initialize a stateful buffer struct to point to the buffer, with |
| * the specified remaining length in bytes. */ |
| void StatefulInit(MemcpyState* state, void* buf, uint64_t len); |
| |
| /* Skip [len] bytes only if there's enough data to skip according |
| * to [state]. |
| * On success, return a meaningless but non-NULL pointer and updates [state]. |
| * On failure, return NULL, set state->overrun to 1. |
| * |
| * Useful for iterating through a binary blob to populate a struct. After the |
| * first failure (buffer overrun), successive calls will always fail. |
| */ |
| void* StatefulSkip(MemcpyState* state, uint64_t len); |
| |
| /* Copy [len] bytes into [dst] only if there's enough data to read according |
| * to [state]. |
| * On success, return [dst] and update [state]. |
| * On failure, return NULL, set state->overrun to 1. |
| * |
| * Useful for iterating through a binary blob to populate a struct. After the |
| * first failure (buffer overrun), successive calls will always fail. |
| */ |
| void* StatefulMemcpy(MemcpyState* state, void* dst, uint64_t len); |
| |
| /* Like StatefulMemcpy() but copies in the opposite direction, populating |
| * data from [src] into the buffer encapsulated in state [state]. |
| * On success, return [src] and update [state]. |
| * On failure, return NULL, set state->overrun to 1. |
| * |
| * Useful for iterating through a structure to populate a binary blob. After the |
| * first failure (buffer overrun), successive calls will always fail. |
| */ |
| const void* StatefulMemcpy_r(MemcpyState* state, const void* src, uint64_t len); |
| |
| /* Like StatefulMemcpy_r() but fills a portion of the encapsulated buffer with |
| * a constant value. |
| * On success, return a meaningless but non-NULL pointer and updates [state]. |
| * On failure, return NULL, set state->overrun to 1. |
| * |
| * After the first failure (buffer overrun), successive calls will always fail. |
| */ |
| const void* StatefulMemset_r(MemcpyState* state, const uint8_t val, |
| uint64_t len); |
| |
| #endif /* VBOOT_FIRMWARE_LIB_UTILITY_H_ */ |