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 26 extern "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 */ 46 int property_get(const char* key, char* value, const char* default_value); 47 48 /* property_get_bool: returns the value of key coerced into a 49 ** boolean. If the property is not set, then the default value is returned. 50 ** 51 * The following is considered to be true (1): 52 ** "1", "true", "y", "yes", "on" 53 ** 54 ** The following is considered to be false (0): 55 ** "0", "false", "n", "no", "off" 56 ** 57 ** The conversion is whitespace-sensitive (e.g. " off" will not be false). 58 ** 59 ** If no property with this key is set (or the key is NULL) or the boolean 60 ** conversion fails, the default value is returned. 61 **/ 62 int8_t property_get_bool(const char *key, int8_t default_value); 63 64 /* property_get_int64: returns the value of key truncated and coerced into a 65 ** int64_t. If the property is not set, then the default value is used. 66 ** 67 ** The numeric conversion is identical to strtoimax with the base inferred: 68 ** - All digits up to the first non-digit characters are read 69 ** - The longest consecutive prefix of digits is converted to a long 70 ** 71 ** Valid strings of digits are: 72 ** - An optional sign character + or - 73 ** - An optional prefix indicating the base (otherwise base 10 is assumed) 74 ** -- 0 prefix is octal 75 ** -- 0x / 0X prefix is hex 76 ** 77 ** Leading/trailing whitespace is ignored. Overflow/underflow will cause 78 ** numeric conversion to fail. 79 ** 80 ** If no property with this key is set (or the key is NULL) or the numeric 81 ** conversion fails, the default value is returned. 82 **/ 83 int64_t property_get_int64(const char *key, int64_t default_value); 84 85 /* property_get_int32: returns the value of key truncated and coerced into an 86 ** int32_t. If the property is not set, then the default value is used. 87 ** 88 ** The numeric conversion is identical to strtoimax with the base inferred: 89 ** - All digits up to the first non-digit characters are read 90 ** - The longest consecutive prefix of digits is converted to a long 91 ** 92 ** Valid strings of digits are: 93 ** - An optional sign character + or - 94 ** - An optional prefix indicating the base (otherwise base 10 is assumed) 95 ** -- 0 prefix is octal 96 ** -- 0x / 0X prefix is hex 97 ** 98 ** Leading/trailing whitespace is ignored. Overflow/underflow will cause 99 ** numeric conversion to fail. 100 ** 101 ** If no property with this key is set (or the key is NULL) or the numeric 102 ** conversion fails, the default value is returned. 103 **/ 104 int32_t property_get_int32(const char *key, int32_t default_value); 105 106 /* property_set: returns 0 on success, < 0 on failure 107 */ 108 int property_set(const char *key, const char *value); 109 110 int property_list(void (*propfn)(const char *key, const char *value, void *cookie), void *cookie); 111 112 #if defined(__BIONIC_FORTIFY) 113 #define __property_get_err_str "property_get() called with too small of a buffer" 114 115 #if defined(__clang__) 116 117 /* Some projects use -Weverything; diagnose_if is clang-specific. */ 118 #pragma clang diagnostic push 119 #pragma clang diagnostic ignored "-Wgcc-compat" 120 int property_get(const char* key, char* value, const char* default_value) 121 __clang_error_if(__bos(value) != __BIONIC_FORTIFY_UNKNOWN_SIZE && 122 __bos(value) < PROPERTY_VALUE_MAX, 123 __property_get_err_str); 124 #pragma clang diagnostic pop 125 126 #else /* defined(__clang__) */ 127 128 extern int __property_get_real(const char *, char *, const char *) 129 __asm__(__USER_LABEL_PREFIX__ "property_get"); 130 __errordecl(__property_get_too_small_error, __property_get_err_str); 131 132 __BIONIC_FORTIFY_INLINE 133 int property_get(const char *key, char *value, const char *default_value) { 134 size_t bos = __bos(value); 135 if (bos < PROPERTY_VALUE_MAX) { 136 __property_get_too_small_error(); 137 } 138 return __property_get_real(key, value, default_value); 139 } 140 141 #endif /* defined(__clang__) */ 142 143 #undef __property_get_err_str 144 #endif /* defined(__BIONIC_FORTIFY) */ 145 146 #ifdef __cplusplus 147 } 148 #endif 149 150 #endif 151
