xref: /aosp_15_r20/external/selinux/libsepol/src/private.h (revision 2d543d20722ada2425b5bdab9d0d1d29470e7bba)

/* Private definitions for libsepol. */

/* Endian conversion for reading and writing binary policies */

#include <sepol/policydb/policydb.h>


#ifdef __APPLE__
#include <sys/types.h>
#include <machine/endian.h>
#else
#include <byteswap.h>
#include <endian.h>
#endif

#include <errno.h>

#ifdef __APPLE__
#define __BYTE_ORDER  BYTE_ORDER
#define __LITTLE_ENDIAN  LITTLE_ENDIAN
#endif

#if __BYTE_ORDER == __LITTLE_ENDIAN
#define cpu_to_le16(x) (x)
#define le16_to_cpu(x) (x)
#define cpu_to_le32(x) (x)
#define le32_to_cpu(x) (x)
#define cpu_to_le64(x) (x)
#define le64_to_cpu(x) (x)
#else
#define cpu_to_le16(x) bswap_16(x)
#define le16_to_cpu(x) bswap_16(x)
#define cpu_to_le32(x) bswap_32(x)
#define le32_to_cpu(x) bswap_32(x)
#define cpu_to_le64(x) bswap_64(x)
#define le64_to_cpu(x) bswap_64(x)
#endif

#undef min
#define min(a,b) (((a) < (b)) ? (a) : (b))

#undef max
#define max(a,b) ((a) >= (b) ? (a) : (b))

#define ARRAY_SIZE(x) (sizeof(x)/sizeof((x)[0]))

static inline int exceeds_available_bytes(const struct policy_file *fp, size_t x, size_t req_elem_size)
{
	size_t req_size;

	/* Remaining input size is only available for mmap'ed memory */
	if (fp->type != PF_USE_MEMORY)
		return 0;

	if (__builtin_mul_overflow(x, req_elem_size, &req_size))
		return 1;

	return req_size > fp->len;
}

#define is_saturated(x) ((x) == (typeof(x))-1)

#define zero_or_saturated(x) (((x) == 0) || is_saturated(x))

#define spaceship_cmp(a, b) (((a) > (b)) - ((a) < (b)))

/* Use to ignore intentional unsigned under- and overflows while running under UBSAN. */
#if defined(__clang__) && defined(__clang_major__) && (__clang_major__ >= 4)
#if (__clang_major__ >= 12)
#define ignore_unsigned_overflow_        __attribute__((no_sanitize("unsigned-integer-overflow", "unsigned-shift-base")))
#else
#define ignore_unsigned_overflow_        __attribute__((no_sanitize("unsigned-integer-overflow")))
#endif
#else
#define ignore_unsigned_overflow_
#endif

/* Policy compatibility information. */
struct policydb_compat_info {
	unsigned int type;
	unsigned int version;
	unsigned int sym_num;
	unsigned int ocon_num;
	unsigned int target_platform;
};

extern const struct policydb_compat_info *policydb_lookup_compat(unsigned int version,
								 unsigned int type,
								 unsigned int target_platform);

/* Reading from a policy "file". */
extern int next_entry(void *buf, struct policy_file *fp, size_t bytes);
extern size_t put_entry(const void *ptr, size_t size, size_t n,
		        struct policy_file *fp);
extern int str_read(char **strp, struct policy_file *fp, size_t len);

#ifndef HAVE_REALLOCARRAY
static inline void* reallocarray(void *ptr, size_t nmemb, size_t size) {
	if (size && nmemb > (size_t)-1 / size) {
		errno = ENOMEM;
		return NULL;
	}

	return realloc(ptr, nmemb * size);
}
#endif