1 /*
2 * Copyright (C) 2008 The Android Open Source Project
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * * Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in
12 * the documentation and/or other materials provided with the
13 * distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 /*
30 * This file is only used to provide backwards compatibility to property areas
31 * created by old versions of init, which occurs when an ota runs. The updater
32 * binary is compiled statically against the newest bionic, but the recovery
33 * ramdisk may be using an old version of init. This can all be removed once
34 * OTAs from pre-K versions are no longer supported.
35 */
36
37 #include <string.h>
38
39 #include "private/bionic_futex.h"
40
41 #define _REALLY_INCLUDE_SYS__SYSTEM_PROPERTIES_H_
42 #include <sys/_system_properties.h>
43
44 #define TOC_NAME_LEN(toc) ((toc) >> 24)
45 #define TOC_TO_INFO(area, toc) ((prop_info_compat*) (((char*) area) + ((toc) & 0xFFFFFF)))
46
47 struct prop_area_compat {
48 unsigned volatile count;
49 unsigned volatile serial;
50 unsigned magic;
51 unsigned version;
52 unsigned reserved[4];
53 unsigned toc[1];
54 };
55
56 typedef struct prop_area_compat prop_area_compat;
57
58 struct prop_area;
59 typedef struct prop_area prop_area;
60
61 struct prop_info_compat {
62 char name[PROP_NAME_MAX];
63 unsigned volatile serial;
64 char value[PROP_VALUE_MAX];
65 };
66
67 typedef struct prop_info_compat prop_info_compat;
68
69 extern prop_area *__system_property_area__;
70
__system_property_find_compat(const char * name)71 __LIBC_HIDDEN__ const prop_info *__system_property_find_compat(const char *name)
72 {
73 prop_area_compat *pa = (prop_area_compat *)__system_property_area__;
74 unsigned count = pa->count;
75 unsigned *toc = pa->toc;
76 unsigned len = strlen(name);
77 prop_info_compat *pi;
78
79 if (len >= PROP_NAME_MAX)
80 return 0;
81 if (len < 1)
82 return 0;
83
84 while(count--) {
85 unsigned entry = *toc++;
86 if(TOC_NAME_LEN(entry) != len) continue;
87
88 pi = TOC_TO_INFO(pa, entry);
89 if(memcmp(name, pi->name, len)) continue;
90
91 return (const prop_info *)pi;
92 }
93
94 return 0;
95 }
96
__system_property_read_compat(const prop_info * _pi,char * name,char * value)97 __LIBC_HIDDEN__ int __system_property_read_compat(const prop_info *_pi, char *name, char *value)
98 {
99 unsigned serial, len;
100 const prop_info_compat *pi = (const prop_info_compat *)_pi;
101
102 for(;;) {
103 serial = pi->serial;
104 while(SERIAL_DIRTY(serial)) {
105 __futex_wait((volatile void *)&pi->serial, serial, NULL);
106 serial = pi->serial;
107 }
108 len = SERIAL_VALUE_LEN(serial);
109 memcpy(value, pi->value, len + 1);
110 if(serial == pi->serial) {
111 if(name != 0) {
112 strcpy(name, pi->name);
113 }
114 return len;
115 }
116 }
117 }
118
__system_property_foreach_compat(void (* propfn)(const prop_info * pi,void * cookie),void * cookie)119 __LIBC_HIDDEN__ int __system_property_foreach_compat(
120 void (*propfn)(const prop_info *pi, void *cookie),
121 void *cookie)
122 {
123 prop_area_compat *pa = (prop_area_compat *)__system_property_area__;
124 unsigned i;
125
126 for (i = 0; i < pa->count; i++) {
127 unsigned entry = pa->toc[i];
128 prop_info_compat *pi = TOC_TO_INFO(pa, entry);
129 propfn((const prop_info *)pi, cookie);
130 }
131
132 return 0;
133 }
134