1 /****************************************************************************** 2 * 3 * Copyright (C) 2016 Google, Inc. 4 * 5 * Licensed under the Apache License, Version 2.0 (the "License"); 6 * you may not use this file except in compliance with the License. 7 * You may obtain a copy of the License at: 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 * 17 ******************************************************************************/ 18 19 #define LOG_TAG "bt_osi_rand" 20 21 #include <assert.h> 22 #include <errno.h> 23 #include <fcntl.h> 24 #include <string.h> 25 #include <sys/types.h> 26 #include <sys/stat.h> 27 #include <unistd.h> 28 29 #include "osi/include/log.h" 30 #include "osi/include/osi.h" 31 32 #define RANDOM_PATH "/dev/urandom" 33 34 int osi_rand(void) { 35 int rand; 36 int rand_fd = open(RANDOM_PATH, O_RDONLY); 37 38 if (rand_fd == INVALID_FD) { 39 LOG_ERROR(LOG_TAG, "%s can't open rand fd %s: %s ", __func__, RANDOM_PATH, 40 strerror(errno)); 41 assert(0); 42 } 43 44 ssize_t read_bytes = read(rand_fd, &rand, sizeof(rand)); 45 close(rand_fd); 46 47 assert(read_bytes == sizeof(rand)); 48 49 if (rand < 0) 50 rand = -rand; 51 52 return rand; 53 } 54
