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strongswan-ext/src/libstrongswan/chunk.h
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/**
* @file chunk.h
*
* @brief Pointer/length abstraction and its functions.
*
*/
/*
* Copyright (C) 2005-2006 Martin Willi
* Copyright (C) 2005 Jan Hutter
* Hochschule fuer Technik Rapperswil
*
* 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 2 of the License, or (at your
* option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
*
* 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.
*/
#ifndef CHUNK_H_
#define CHUNK_H_
#include <string.h>
#include <stdarg.h>
#include <library.h>
typedef struct chunk_t chunk_t;
/**
* General purpose pointer/length abstraction.
*/
struct chunk_t {
/** Pointer to start of data */
u_char *ptr;
/** Length of data in bytes */
size_t len;
};
/**
* A { NULL, 0 }-chunk handy for initialization.
*/
extern chunk_t chunk_empty;
/**
* Create a new chunk pointing to "ptr" with length "len"
*/
chunk_t chunk_create(u_char *ptr, size_t len);
/**
* Create a clone of a chunk pointing to "ptr"
*/
chunk_t chunk_create_clone(u_char *ptr, chunk_t chunk);
/**
* Calculate length of multiple chunks
*/
size_t chunk_length(const char *mode, ...);
/**
* Concatenate chunks into a chunk pointing to "ptr",
* "mode" is a string of "c" (copy) and "m" (move), which says
* how to handle to chunks in "..."
*/
chunk_t chunk_create_cat(u_char *ptr, const char* mode, ...);
/**
* Split up a chunk into parts, "mode" is a string of "a" (alloc),
* "c" (copy) and "m" (move). Each letter say for the corresponding chunk if
* it should get allocated on heap, copied into existing chunk, or the chunk
* should point into "chunk". The length of each part is an argument before
* each target chunk. E.g.:
* chunk_split(chunk, "mcac", 3, &a, 7, &b, 5, &c, d.len, &d);
*/
void chunk_split(chunk_t chunk, const char *mode, ...);
/**
* Write the binary contents of a chunk_t to a file
*/
bool chunk_write(chunk_t chunk, const char *path, const char *label, mode_t mask, bool force);
/**
* Free contents of a chunk
*/
void chunk_free(chunk_t *chunk);
/**
* Overwrite the contents of a chunk with pseudo-random bytes and free them
*/
void chunk_free_randomized(chunk_t *chunk);
/**
* Initialize a chunk to point to buffer inspectable by sizeof()
*/
#define chunk_from_buf(str) { str, sizeof(str) }
/**
* Initialize a chunk to point to a thing
*/
#define chunk_from_thing(thing) chunk_create((char*)&(thing), sizeof(thing))
/**
* Allocate a chunk on the heap
*/
#define chunk_alloc(bytes) chunk_create(malloc(bytes), bytes)
/**
* Allocate a chunk on the stack
*/
#define chunk_alloca(bytes) chunk_create(alloca(bytes), bytes)
/**
* Clone a chunk on heap
*/
#define chunk_clone(chunk) chunk_create_clone(malloc(chunk.len), chunk)
/**
* Clone a chunk on stack
*/
#define chunk_clonea(chunk) chunk_create_clone(alloca(chunk.len), chunk)
/**
* Concatenate chunks into a chunk on heap
*/
#define chunk_cat(mode, ...) chunk_create_cat(malloc(chunk_length(mode, __VA_ARGS__)), mode, __VA_ARGS__)
/**
* Concatenate chunks into a chunk on stack
*/
#define chunk_cata(mode, ...) chunk_create_cat(alloca(chunk_length(mode, __VA_ARGS__)), mode, __VA_ARGS__)
/**
* Skip n bytes in chunk (forward pointer, shorten length)
*/
chunk_t chunk_skip(chunk_t chunk, size_t bytes);
/**
* Compare two chunks, returns zero if a equals b
* or negative/positive if a is small/greater than b
*/
int chunk_compare(chunk_t a, chunk_t b);
/**
* Compare two chunks for equality,
* NULL chunks are never equal.
*/
bool chunk_equals(chunk_t a, chunk_t b);
/**
* Compare two chunks for equality,
* NULL chunks are always equal.
*/
bool chunk_equals_or_null(chunk_t a, chunk_t b);
#endif /* CHUNK_H_ */