utils.h File Reference

Zero-overhead utility functions and RAII cleanup helpers. More...

#include <stdarg.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

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Macros
#define	CLEANUP_FILE   __attribute__((cleanup(cleanup_file)))
	Macro to define a FILE* that closes itself at scope exit. More...
#define	RAII_SATISFY_FILE(f)   (void)0
	Satisfies Static Analyzers for file resource management. More...
#define	CLEANUP_FREE   __attribute__((cleanup(cleanup_free)))
	Macro to define a pointer that frees itself at scope exit. More...
#define	RAII_SATISFY_FREE(p)   (void)0
	Satisfies Static Analyzers for memory resource management. More...
#define	TRANSFER_OWNERSHIP(ptr)
	Transfers ownership of an RAII-managed variable to the caller. More...

Functions
void *	utils_buffer_offset (size_t offset)
	Helper to securely cast an integer offset to a pointer, often used for VBO/EBO byte offsets. More...
int	safe_snprintf (char *buf, size_t buf_size, const char *format,...)
	Safe wrapper around vsnprintf to format strings with bounds checking. More...
static bool	check_flag (int value, int flag)
	Bitwise flag check helper. More...
void *	safe_calloc (size_t num, size_t size)
	calloc wrapper with zero-size check. More...
bool	safe_memcpy (void *dest, size_t dest_size, const void *src, size_t count)
	memcpy wrapper with bounds checking. More...
bool	safe_memset (void *dest, size_t dest_size, int value, size_t count)
	memset wrapper with bounds checking. More...
void	safe_strncpy (char *dest, size_t dest_size, const char *src, size_t src_size)
	Safe wrapper around strncpy to ensure null-termination. More...
void	safe_strncat (char *dest, size_t dest_size, const char *src)
	Safe wrapper around strncat to ensure bounds safety. More...
bool	is_safe_filename (const char *filename)
	Validates a filename to prevent path traversal and shell injection. More...
bool	is_safe_relative_path (const char *path)
	Validates a relative path to prevent arbitrary file access. More...
static void	cleanup_file (FILE **file_ptr)
	RAII callback for FILE*. More...
static void	cleanup_free (void *ptr_ptr)
	RAII callback for free(). More...

Detailed Description

Zero-overhead utility functions and RAII cleanup helpers.

Macro Definition Documentation

CLEANUP_FILE

#define CLEANUP_FILE   __attribute__((cleanup(cleanup_file)))

Macro to define a FILE* that closes itself at scope exit.

CLEANUP_FREE

#define CLEANUP_FREE   __attribute__((cleanup(cleanup_free)))

Macro to define a pointer that frees itself at scope exit.

RAII_SATISFY_FILE

#define RAII_SATISFY_FILE

(

f

)

(void)0

Satisfies Static Analyzers for file resource management.

RAII_SATISFY_FREE

#define RAII_SATISFY_FREE

(

p

)

(void)0

Satisfies Static Analyzers for memory resource management.

TRANSFER_OWNERSHIP

#define TRANSFER_OWNERSHIP

(

ptr

)

Value:

    ({                                        \
        __typeof__(ptr) _tmp_ptr = (ptr); \
        (ptr) = 0;                        \
        _tmp_ptr;                         \
    })

Transfers ownership of an RAII-managed variable to the caller.

Sets the local variable to NULL to prevent the cleanup attribute from triggering.

Function Documentation

check_flag()

static bool check_flag ( int  value, int  flag  )

inlinestatic

Bitwise flag check helper.

cleanup_file()

static void cleanup_file ( FILE **  file_ptr )

inlinestatic

RAII callback for FILE*.

cleanup_free()

static void cleanup_free ( void *  ptr_ptr )

inlinestatic

RAII callback for free().

is_safe_filename()

bool is_safe_filename

(

const char *

filename

)

Validates a filename to prevent path traversal and shell injection.

Rejects strings containing path separators ('/', '\') or directory traversal sequences ("..") or current directory (".").

Parameters

filename

The filename to check.

Returns

true if the filename is safe, false otherwise.

is_safe_relative_path()

bool is_safe_relative_path

(

const char *

path

)

Validates a relative path to prevent arbitrary file access.

Rejects absolute paths, parent directory traversal (".."), and platform-specific path features like backslashes or drive letters.

Parameters

path	The relative path to check.

Returns

true if the path is safe, false otherwise.

safe_calloc()

void* safe_calloc	(	size_t	num,
		size_t	size
	)

calloc wrapper with zero-size check.

safe_memcpy()

bool safe_memcpy	(	void *	dest,
		size_t	dest_size,
		const void *	src,
		size_t	count
	)

memcpy wrapper with bounds checking.

safe_memset()

bool safe_memset	(	void *	dest,
		size_t	dest_size,
		int	value,
		size_t	count
	)

memset wrapper with bounds checking.

safe_snprintf()

int safe_snprintf	(	char *	buf,
		size_t	buf_size,
		const char *	format,
			...
	)

Safe wrapper around vsnprintf to format strings with bounds checking.

Parameters

buf	Destination buffer.
buf_size	Buffer capacity.
format	Printf-style format string.

Returns

number of characters written (excluding null terminator) on success, -1 if truncated or error.

safe_strncat()

void safe_strncat	(	char *	dest,
		size_t	dest_size,
		const char *	src
	)

Safe wrapper around strncat to ensure bounds safety.

Parameters

dest	Destination buffer.
dest_size	Total size of destination buffer.
src	Source string.

safe_strncpy()

void safe_strncpy	(	char *	dest,
		size_t	dest_size,
		const char *	src,
		size_t	src_size
	)

Safe wrapper around strncpy to ensure null-termination.

Parameters

dest	Destination buffer.
dest_size	Size of destination buffer.
src	Source string.
src_size	Max characters to copy (or just use sizeof(dest)).

utils_buffer_offset()

void* utils_buffer_offset

(

size_t

offset

)

Helper to securely cast an integer offset to a pointer, often used for VBO/EBO byte offsets.

Parameters

offset

The byte offset to cast.

Returns

A void pointer representing the offset.