1/* 2 * Copyright (C) 2006 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17#ifndef __CUTILS_PROPERTIES_H 18#define __CUTILS_PROPERTIES_H 19 20#include <sys/cdefs.h> 21#include <stddef.h> 22#include <sys/system_properties.h> 23#include <stdint.h> 24 25#ifdef __cplusplus 26extern "C" { 27#endif 28 29/* System properties are *small* name value pairs managed by the 30** property service. If your data doesn't fit in the provided 31** space it is not appropriate for a system property. 32** 33** WARNING: system/bionic/include/sys/system_properties.h also defines 34** these, but with different names. (TODO: fix that) 35*/ 36#define PROPERTY_KEY_MAX PROP_NAME_MAX 37#define PROPERTY_VALUE_MAX PROP_VALUE_MAX 38 39/* property_get: returns the length of the value which will never be 40** greater than PROPERTY_VALUE_MAX - 1 and will always be zero terminated. 41** (the length does not include the terminating zero). 42** 43** If the property read fails or returns an empty value, the default 44** value is used (if nonnull). 45*/ 46int property_get(const char *key, char *value, const char *default_value) 47/* Sometimes we use not-Bionic with this, so we need this check. */ 48#if defined(__BIONIC_FORTIFY) 49 __overloadable __RENAME_CLANG(property_get) 50#endif 51 ; 52 53/* property_get_bool: returns the value of key coerced into a 54** boolean. If the property is not set, then the default value is returned. 55** 56* The following is considered to be true (1): 57** "1", "true", "y", "yes", "on" 58** 59** The following is considered to be false (0): 60** "0", "false", "n", "no", "off" 61** 62** The conversion is whitespace-sensitive (e.g. " off" will not be false). 63** 64** If no property with this key is set (or the key is NULL) or the boolean 65** conversion fails, the default value is returned. 66**/ 67int8_t property_get_bool(const char *key, int8_t default_value); 68 69/* property_get_int64: returns the value of key truncated and coerced into a 70** int64_t. If the property is not set, then the default value is used. 71** 72** The numeric conversion is identical to strtoimax with the base inferred: 73** - All digits up to the first non-digit characters are read 74** - The longest consecutive prefix of digits is converted to a long 75** 76** Valid strings of digits are: 77** - An optional sign character + or - 78** - An optional prefix indicating the base (otherwise base 10 is assumed) 79** -- 0 prefix is octal 80** -- 0x / 0X prefix is hex 81** 82** Leading/trailing whitespace is ignored. Overflow/underflow will cause 83** numeric conversion to fail. 84** 85** If no property with this key is set (or the key is NULL) or the numeric 86** conversion fails, the default value is returned. 87**/ 88int64_t property_get_int64(const char *key, int64_t default_value); 89 90/* property_get_int32: returns the value of key truncated and coerced into an 91** int32_t. If the property is not set, then the default value is used. 92** 93** The numeric conversion is identical to strtoimax with the base inferred: 94** - All digits up to the first non-digit characters are read 95** - The longest consecutive prefix of digits is converted to a long 96** 97** Valid strings of digits are: 98** - An optional sign character + or - 99** - An optional prefix indicating the base (otherwise base 10 is assumed) 100** -- 0 prefix is octal 101** -- 0x / 0X prefix is hex 102** 103** Leading/trailing whitespace is ignored. Overflow/underflow will cause 104** numeric conversion to fail. 105** 106** If no property with this key is set (or the key is NULL) or the numeric 107** conversion fails, the default value is returned. 108**/ 109int32_t property_get_int32(const char *key, int32_t default_value); 110 111/* property_set: returns 0 on success, < 0 on failure 112*/ 113int property_set(const char *key, const char *value); 114 115int property_list(void (*propfn)(const char *key, const char *value, void *cookie), void *cookie); 116 117#if defined(__BIONIC_FORTIFY) 118#define __property_get_err_str "property_get() called with too small of a buffer" 119 120#if defined(__clang__) 121 122/* Some projects use -Weverything; enable_if is clang-specific. 123** FIXME: This is marked used because we'll otherwise get complaints about an 124** unused static function. This is more robust than marking it unused, since 125** -Wused-but-marked-unused is a thing that will complain if this function is 126** actually used, thus making FORTIFY noisier when an error happens. It's going 127** to go away anyway during our FORTIFY cleanup. 128**/ 129#pragma clang diagnostic push 130#pragma clang diagnostic ignored "-Wgcc-compat" 131__BIONIC_ERROR_FUNCTION_VISIBILITY 132int property_get(const char *key, char *value, const char *default_value) 133 __overloadable 134 __enable_if(__bos(value) != __BIONIC_FORTIFY_UNKNOWN_SIZE && 135 __bos(value) < PROPERTY_VALUE_MAX, __property_get_err_str) 136 __errorattr(__property_get_err_str) 137 __attribute__((used)); 138#pragma clang diagnostic pop 139 140/* No object size? No FORTIFY. 141*/ 142 143#else /* defined(__clang__) */ 144 145extern int __property_get_real(const char *, char *, const char *) 146 __asm__(__USER_LABEL_PREFIX__ "property_get"); 147__errordecl(__property_get_too_small_error, __property_get_err_str); 148 149__BIONIC_FORTIFY_INLINE 150int property_get(const char *key, char *value, const char *default_value) { 151 size_t bos = __bos(value); 152 if (bos < PROPERTY_VALUE_MAX) { 153 __property_get_too_small_error(); 154 } 155 return __property_get_real(key, value, default_value); 156} 157 158#endif /* defined(__clang__) */ 159 160#undef __property_get_err_str 161#endif /* defined(__BIONIC_FORTIFY) */ 162 163#ifdef __cplusplus 164} 165#endif 166 167#endif 168