tools/testing/selftests/bpf/bpf_rand.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef __BPF_RAND__
   3 #define __BPF_RAND__
   4
   5 #include <stdint.h>
   6 #include <stdlib.h>
   7 #include <time.h>
   8
   9 static inline uint64_t bpf_rand_mask(uint64_t mask)
  10 {
  11         return (((uint64_t)(uint32_t)rand()) |
  12                 ((uint64_t)(uint32_t)rand() << 32)) & mask;
  13 }
  14
  15 #define bpf_rand_ux(x, m)                       \
  16 static inline uint64_t bpf_rand_u##x(int shift) \
  17 {                                               \
  18         return bpf_rand_mask((m)) << shift;     \
  19 }
  20
  21 bpf_rand_ux( 8,               0xffULL)
  22 bpf_rand_ux(16,             0xffffULL)
  23 bpf_rand_ux(24,           0xffffffULL)
  24 bpf_rand_ux(32,         0xffffffffULL)
  25 bpf_rand_ux(40,       0xffffffffffULL)
  26 bpf_rand_ux(48,     0xffffffffffffULL)
  27 bpf_rand_ux(56,   0xffffffffffffffULL)
  28 bpf_rand_ux(64, 0xffffffffffffffffULL)
  29
  30 static inline void bpf_semi_rand_init(void)
  31 {
  32         srand(time(NULL));
  33 }
  34
  35 static inline uint64_t bpf_semi_rand_get(void)
  36 {
  37         switch (rand() % 39) {
  38         case  0: return 0x000000ff00000000ULL | bpf_rand_u8(0);
  39         case  1: return 0xffffffff00000000ULL | bpf_rand_u16(0);
  40         case  2: return 0x00000000ffff0000ULL | bpf_rand_u16(0);
  41         case  3: return 0x8000000000000000ULL | bpf_rand_u32(0);
  42         case  4: return 0x00000000f0000000ULL | bpf_rand_u32(0);
  43         case  5: return 0x0000000100000000ULL | bpf_rand_u24(0);
  44         case  6: return 0x800ff00000000000ULL | bpf_rand_u32(0);
  45         case  7: return 0x7fffffff00000000ULL | bpf_rand_u32(0);
  46         case  8: return 0xffffffffffffff00ULL ^ bpf_rand_u32(24);
  47         case  9: return 0xffffffffffffff00ULL | bpf_rand_u8(0);
  48         case 10: return 0x0000000010000000ULL | bpf_rand_u32(0);
  49         case 11: return 0xf000000000000000ULL | bpf_rand_u8(0);
  50         case 12: return 0x0000f00000000000ULL | bpf_rand_u8(8);
  51         case 13: return 0x000000000f000000ULL | bpf_rand_u8(16);
  52         case 14: return 0x0000000000000f00ULL | bpf_rand_u8(32);
  53         case 15: return 0x00fff00000000f00ULL | bpf_rand_u8(48);
  54         case 16: return 0x00007fffffffffffULL ^ bpf_rand_u32(1);
  55         case 17: return 0xffff800000000000ULL | bpf_rand_u8(4);
  56         case 18: return 0xffff800000000000ULL | bpf_rand_u8(20);
  57         case 19: return (0xffffffc000000000ULL + 0x80000ULL) | bpf_rand_u32(0);
  58         case 20: return (0xffffffc000000000ULL - 0x04000000ULL) | bpf_rand_u32(0);
  59         case 21: return 0x0000000000000000ULL | bpf_rand_u8(55) | bpf_rand_u32(20);
  60         case 22: return 0xffffffffffffffffULL ^ bpf_rand_u8(3) ^ bpf_rand_u32(40);
  61         case 23: return 0x0000000000000000ULL | bpf_rand_u8(bpf_rand_u8(0) % 64);
  62         case 24: return 0x0000000000000000ULL | bpf_rand_u16(bpf_rand_u8(0) % 64);
  63         case 25: return 0xffffffffffffffffULL ^ bpf_rand_u8(bpf_rand_u8(0) % 64);
  64         case 26: return 0xffffffffffffffffULL ^ bpf_rand_u40(bpf_rand_u8(0) % 64);
  65         case 27: return 0x0000800000000000ULL;
  66         case 28: return 0x8000000000000000ULL;
  67         case 29: return 0x0000000000000000ULL;
  68         case 30: return 0xffffffffffffffffULL;
  69         case 31: return bpf_rand_u16(bpf_rand_u8(0) % 64);
  70         case 32: return bpf_rand_u24(bpf_rand_u8(0) % 64);
  71         case 33: return bpf_rand_u32(bpf_rand_u8(0) % 64);
  72         case 34: return bpf_rand_u40(bpf_rand_u8(0) % 64);
  73         case 35: return bpf_rand_u48(bpf_rand_u8(0) % 64);
  74         case 36: return bpf_rand_u56(bpf_rand_u8(0) % 64);
  75         case 37: return bpf_rand_u64(bpf_rand_u8(0) % 64);
  76         default: return bpf_rand_u64(0);
  77         }
  78 }
  79
  80 #endif /* __BPF_RAND__ */