1 /* 2 * Copyright (c) 2016 Nordic Semiconductor ASA 3 * Copyright (c) 2016 Vinayak Kariappa Chettimada 4 * 5 * SPDX-License-Identifier: Apache-2.0 6 */ 7 8 #include <zephyr/types.h> 9 #include <zephyr/sys/byteorder.h> 10 #include <zephyr/ztest.h> 11 #include "util.h" 12 13 #include "pdu_df.h" 14 #include "lll/pdu_vendor.h" 15 #include "pdu.h" 16 17 #include "util/mem.h" 18 #include "util/memq.h" 19 #include "util/mayfly.h" 20 #include "lll.h" 21 22 /** 23 * @brief Population count: Count the number of bits set to 1 24 * 25 * @param octets Data to count over 26 * @param octets_len Must not be bigger than 255/8 = 31 bytes 27 * 28 * @return popcnt of 'octets' 29 */ util_ones_count_get(uint8_t * octets,uint8_t octets_len)30uint8_t util_ones_count_get(uint8_t *octets, uint8_t octets_len) 31 { 32 uint8_t one_count = 0U; 33 34 while (octets_len--) { 35 uint8_t bite; 36 37 bite = *octets; 38 while (bite) { 39 bite &= (bite - 1); 40 one_count++; 41 } 42 octets++; 43 } 44 45 return one_count; 46 } 47 util_rand(void * buf,size_t len)48int util_rand(void *buf, size_t len) 49 { 50 return 0xDEADBEEF; 51 } 52 53 /** @brief Prepare access address as per BT Spec. 54 * 55 * - It shall have no more than six consecutive zeros or ones. 56 * - It shall not be the advertising channel packets' Access Address. 57 * - It shall not be a sequence that differs from the advertising channel 58 * packets Access Address by only one bit. 59 * - It shall not have all four octets equal. 60 * - It shall have no more than 24 transitions. 61 * - It shall have a minimum of two transitions in the most significant six 62 * bits. 63 * 64 * LE Coded PHY requirements: 65 * - It shall have at least three ones in the least significant 8 bits. 66 * - It shall have no more than eleven transitions in the least significant 16 67 * bits. 68 */ util_aa_le32(uint8_t * dst)69int util_aa_le32(uint8_t *dst) 70 { 71 #if defined(CONFIG_BT_CTLR_PHY_CODED) 72 uint8_t transitions_lsb16; 73 uint8_t ones_count_lsb8; 74 #endif /* CONFIG_BT_CTLR_PHY_CODED */ 75 uint8_t consecutive_cnt; 76 uint8_t consecutive_bit; 77 uint32_t adv_aa_check; 78 uint32_t aa; 79 uint8_t transitions; 80 uint8_t bit_idx; 81 uint8_t retry; 82 83 retry = 3U; 84 again: 85 if (!retry) { 86 return -EFAULT; 87 } 88 retry--; 89 90 *dst = lll_csrand_get(dst, sizeof(uint32_t)); 91 aa = sys_get_le32(dst); 92 93 bit_idx = 31U; 94 transitions = 0U; 95 consecutive_cnt = 1U; 96 #if defined(CONFIG_BT_CTLR_PHY_CODED) 97 ones_count_lsb8 = 0U; 98 transitions_lsb16 = 0U; 99 #endif /* CONFIG_BT_CTLR_PHY_CODED */ 100 consecutive_bit = (aa >> bit_idx) & 0x01; 101 while (bit_idx--) { 102 #if defined(CONFIG_BT_CTLR_PHY_CODED) 103 uint8_t transitions_lsb16_prev = transitions_lsb16; 104 #endif /* CONFIG_BT_CTLR_PHY_CODED */ 105 uint8_t consecutive_cnt_prev = consecutive_cnt; 106 uint8_t transitions_prev = transitions; 107 uint8_t bit; 108 109 bit = (aa >> bit_idx) & 0x01; 110 if (bit == consecutive_bit) { 111 consecutive_cnt++; 112 } else { 113 consecutive_cnt = 1U; 114 consecutive_bit = bit; 115 transitions++; 116 117 #if defined(CONFIG_BT_CTLR_PHY_CODED) 118 if (bit_idx < 15) { 119 transitions_lsb16++; 120 } 121 #endif /* CONFIG_BT_CTLR_PHY_CODED */ 122 } 123 124 #if defined(CONFIG_BT_CTLR_PHY_CODED) 125 if ((bit_idx < 8) && consecutive_bit) { 126 ones_count_lsb8++; 127 } 128 #endif /* CONFIG_BT_CTLR_PHY_CODED */ 129 130 /* It shall have no more than six consecutive zeros or ones. */ 131 /* It shall have a minimum of two transitions in the most 132 * significant six bits. 133 */ 134 if ((consecutive_cnt > 6) || 135 #if defined(CONFIG_BT_CTLR_PHY_CODED) 136 (!consecutive_bit && (((bit_idx < 6) && (ones_count_lsb8 < 1)) || 137 ((bit_idx < 5) && (ones_count_lsb8 < 2)) || 138 ((bit_idx < 4) && (ones_count_lsb8 < 3)))) || 139 #endif /* CONFIG_BT_CTLR_PHY_CODED */ 140 ((consecutive_cnt < 6) && (((bit_idx < 29) && (transitions < 1)) || 141 ((bit_idx < 28) && (transitions < 2))))) { 142 if (consecutive_bit) { 143 consecutive_bit = 0U; 144 aa &= ~BIT(bit_idx); 145 #if defined(CONFIG_BT_CTLR_PHY_CODED) 146 if (bit_idx < 8) { 147 ones_count_lsb8--; 148 } 149 #endif /* CONFIG_BT_CTLR_PHY_CODED */ 150 } else { 151 consecutive_bit = 1U; 152 aa |= BIT(bit_idx); 153 #if defined(CONFIG_BT_CTLR_PHY_CODED) 154 if (bit_idx < 8) { 155 ones_count_lsb8++; 156 } 157 #endif /* CONFIG_BT_CTLR_PHY_CODED */ 158 } 159 160 if (transitions != transitions_prev) { 161 consecutive_cnt = consecutive_cnt_prev; 162 transitions = transitions_prev; 163 } else { 164 consecutive_cnt = 1U; 165 transitions++; 166 } 167 168 #if defined(CONFIG_BT_CTLR_PHY_CODED) 169 if (bit_idx < 15) { 170 if (transitions_lsb16 != transitions_lsb16_prev) { 171 transitions_lsb16 = transitions_lsb16_prev; 172 } else { 173 transitions_lsb16++; 174 } 175 } 176 #endif /* CONFIG_BT_CTLR_PHY_CODED */ 177 } 178 179 /* It shall have no more than 24 transitions 180 * It shall have no more than eleven transitions in the least 181 * significant 16 bits. 182 */ 183 if ((transitions > 24) || 184 #if defined(CONFIG_BT_CTLR_PHY_CODED) 185 (transitions_lsb16 > 11) || 186 #endif /* CONFIG_BT_CTLR_PHY_CODED */ 187 0) { 188 if (consecutive_bit) { 189 aa &= ~(BIT(bit_idx + 1) - 1); 190 } else { 191 aa |= (BIT(bit_idx + 1) - 1); 192 } 193 194 break; 195 } 196 } 197 198 /* It shall not be the advertising channel packets Access Address. 199 * It shall not be a sequence that differs from the advertising channel 200 * packets Access Address by only one bit. 201 */ 202 adv_aa_check = aa ^ PDU_AC_ACCESS_ADDR; 203 if (util_ones_count_get((uint8_t *)&adv_aa_check, sizeof(adv_aa_check)) <= 1) { 204 goto again; 205 } 206 207 /* It shall not have all four octets equal. */ 208 if (!((aa & 0xFFFF) ^ (aa >> 16)) && !((aa & 0xFF) ^ (aa >> 24))) { 209 goto again; 210 } 211 212 sys_put_le32(aa, dst); 213 214 return 0; 215 } 216
