1 /* Private definitions for libsepol. */
2 
3 /* Endian conversion for reading and writing binary policies */
4 
5 #include <sepol/policydb/policydb.h>
6 
7 
8 #ifdef __APPLE__
9 #include <sys/types.h>
10 #include <machine/endian.h>
11 #else
12 #include <byteswap.h>
13 #include <endian.h>
14 #endif
15 
16 #include <errno.h>
17 
18 #ifdef __APPLE__
19 #define __BYTE_ORDER  BYTE_ORDER
20 #define __LITTLE_ENDIAN  LITTLE_ENDIAN
21 #endif
22 
23 #if __BYTE_ORDER == __LITTLE_ENDIAN
24 #define cpu_to_le16(x) (x)
25 #define le16_to_cpu(x) (x)
26 #define cpu_to_le32(x) (x)
27 #define le32_to_cpu(x) (x)
28 #define cpu_to_le64(x) (x)
29 #define le64_to_cpu(x) (x)
30 #else
31 #define cpu_to_le16(x) bswap_16(x)
32 #define le16_to_cpu(x) bswap_16(x)
33 #define cpu_to_le32(x) bswap_32(x)
34 #define le32_to_cpu(x) bswap_32(x)
35 #define cpu_to_le64(x) bswap_64(x)
36 #define le64_to_cpu(x) bswap_64(x)
37 #endif
38 
39 #undef min
40 #define min(a,b) (((a) < (b)) ? (a) : (b))
41 
42 #undef max
43 #define max(a,b) ((a) >= (b) ? (a) : (b))
44 
45 #define ARRAY_SIZE(x) (sizeof(x)/sizeof((x)[0]))
46 
47 #ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
48 # define is_saturated(x) (x == (typeof(x))-1 || (x) > (1U << 16))
49 #else
50 # define is_saturated(x) (x == (typeof(x))-1)
51 #endif
52 
53 #define zero_or_saturated(x) ((x == 0) || is_saturated(x))
54 
55 #define spaceship_cmp(a, b) (((a) > (b)) - ((a) < (b)))
56 
57 /* Use to ignore intentional unsigned under- and overflows while running under UBSAN. */
58 #if defined(__clang__) && defined(__clang_major__) && (__clang_major__ >= 4)
59 #if (__clang_major__ >= 12)
60 #define ignore_unsigned_overflow_        __attribute__((no_sanitize("unsigned-integer-overflow", "unsigned-shift-base")))
61 #else
62 #define ignore_unsigned_overflow_        __attribute__((no_sanitize("unsigned-integer-overflow")))
63 #endif
64 #else
65 #define ignore_unsigned_overflow_
66 #endif
67 
68 /* Policy compatibility information. */
69 struct policydb_compat_info {
70 	unsigned int type;
71 	unsigned int version;
72 	unsigned int sym_num;
73 	unsigned int ocon_num;
74 	unsigned int target_platform;
75 };
76 
77 extern const struct policydb_compat_info *policydb_lookup_compat(unsigned int version,
78 								 unsigned int type,
79 								 unsigned int target_platform);
80 
81 /* Reading from a policy "file". */
82 extern int next_entry(void *buf, struct policy_file *fp, size_t bytes);
83 extern size_t put_entry(const void *ptr, size_t size, size_t n,
84 		        struct policy_file *fp);
85 extern int str_read(char **strp, struct policy_file *fp, size_t len);
86 
87 #ifndef HAVE_REALLOCARRAY
reallocarray(void *ptr, size_t nmemb, size_t size)88 static inline void* reallocarray(void *ptr, size_t nmemb, size_t size) {
89 	if (size && nmemb > (size_t)-1 / size) {
90 		errno = ENOMEM;
91 		return NULL;
92 	}
93 
94 	return realloc(ptr, nmemb * size);
95 }
96 #endif
97