1 /*
2 * Copyright (C) 2019 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 #include <binder/Stability.h>
17
18 #include <binder/BpBinder.h>
19 #include <binder/Binder.h>
20
21 namespace android {
22 namespace internal {
23
markCompilationUnit(IBinder * binder)24 void Stability::markCompilationUnit(IBinder* binder) {
25 status_t result = set(binder, getLocalStability(), true /*log*/);
26 LOG_ALWAYS_FATAL_IF(result != OK, "Should only mark known object.");
27 }
28
markVintf(IBinder * binder)29 void Stability::markVintf(IBinder* binder) {
30 status_t result = set(binder, Level::VINTF, true /*log*/);
31 LOG_ALWAYS_FATAL_IF(result != OK, "Should only mark known object.");
32 }
33
debugLogStability(const std::string & tag,const sp<IBinder> & binder)34 void Stability::debugLogStability(const std::string& tag, const sp<IBinder>& binder) {
35 ALOGE("%s: stability is %s", tag.c_str(), stabilityString(get(binder.get())).c_str());
36 }
37
markVndk(IBinder * binder)38 void Stability::markVndk(IBinder* binder) {
39 status_t result = set(binder, Level::VENDOR, true /*log*/);
40 LOG_ALWAYS_FATAL_IF(result != OK, "Should only mark known object.");
41 }
42
requiresVintfDeclaration(const sp<IBinder> & binder)43 bool Stability::requiresVintfDeclaration(const sp<IBinder>& binder) {
44 return check(get(binder.get()), Level::VINTF);
45 }
46
tryMarkCompilationUnit(IBinder * binder)47 void Stability::tryMarkCompilationUnit(IBinder* binder) {
48 (void) set(binder, getLocalStability(), false /*log*/);
49 }
50
getLocalStability()51 Stability::Level Stability::getLocalStability() {
52 #ifdef __ANDROID_VNDK__
53 #ifdef __ANDROID_APEX__
54 // TODO(b/142684679) avoid use_vendor on system APEXes
55 #if !defined(__ANDROID_APEX_COM_ANDROID_MEDIA_SWCODEC__) \
56 && !defined(__ANDROID_APEX_TEST_COM_ANDROID_MEDIA_SWCODEC__)
57 #error VNDK + APEX only defined for com.android.media.swcodec
58 #endif
59 // TODO(b/142684679) avoid use_vendor on system APEXes
60 return Level::SYSTEM;
61 #else
62 return Level::VENDOR;
63 #endif
64 #else
65 // TODO(b/139325195): split up stability levels for system/APEX.
66 return Level::SYSTEM;
67 #endif
68 }
69
set(IBinder * binder,int32_t stability,bool log)70 status_t Stability::set(IBinder* binder, int32_t stability, bool log) {
71 Level currentStability = get(binder);
72
73 // null binder is always written w/ 'UNDECLARED' stability
74 if (binder == nullptr) {
75 if (stability == UNDECLARED) {
76 return OK;
77 } else {
78 if (log) {
79 ALOGE("Null binder written with stability %s.",
80 stabilityString(stability).c_str());
81 }
82 return BAD_TYPE;
83 }
84 }
85
86 if (!isDeclaredStability(stability)) {
87 if (log) {
88 ALOGE("Can only set known stability, not %d.", stability);
89 }
90 return BAD_TYPE;
91 }
92
93 if (currentStability != Level::UNDECLARED && currentStability != stability) {
94 if (log) {
95 ALOGE("Interface being set with %s but it is already marked as %s.",
96 stabilityString(stability).c_str(), stabilityString(currentStability).c_str());
97 }
98 return BAD_TYPE;
99 }
100
101 if (currentStability == stability) return OK;
102
103 BBinder* local = binder->localBinder();
104 if (local != nullptr) {
105 local->mStability = static_cast<int32_t>(stability);
106 } else {
107 binder->remoteBinder()->mStability = static_cast<int32_t>(stability);
108 }
109
110 return OK;
111 }
112
get(IBinder * binder)113 Stability::Level Stability::get(IBinder* binder) {
114 if (binder == nullptr) return UNDECLARED;
115
116 BBinder* local = binder->localBinder();
117 if (local != nullptr) {
118 return static_cast<Stability::Level>(local->mStability);
119 }
120
121 return static_cast<Stability::Level>(binder->remoteBinder()->mStability);
122 }
123
check(int32_t provided,Level required)124 bool Stability::check(int32_t provided, Level required) {
125 bool stable = (provided & required) == required;
126
127 if (!isDeclaredStability(provided) && provided != UNDECLARED) {
128 ALOGE("Unknown stability when checking interface stability %d.", provided);
129
130 stable = false;
131 }
132
133 return stable;
134 }
135
isDeclaredStability(int32_t stability)136 bool Stability::isDeclaredStability(int32_t stability) {
137 return stability == VENDOR || stability == SYSTEM || stability == VINTF;
138 }
139
stabilityString(int32_t stability)140 std::string Stability::stabilityString(int32_t stability) {
141 switch (stability) {
142 case Level::UNDECLARED: return "undeclared stability";
143 case Level::VENDOR: return "vendor stability";
144 case Level::SYSTEM: return "system stability";
145 case Level::VINTF: return "vintf stability";
146 }
147 return "unknown stability " + std::to_string(stability);
148 }
149
150 } // namespace internal
151 } // namespace stability
152