1 /*
2  * Copyright (C) 2012 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 #include <stdint.h>
18 #include <sys/types.h>
19 
20 #include <binder/PermissionCache.h>
21 #include <binder/IPCThreadState.h>
22 
23 #include <private/android_filesystem_config.h>
24 
25 #include "Client.h"
26 #include "Layer.h"
27 #include "SurfaceFlinger.h"
28 
29 namespace android {
30 
31 // ---------------------------------------------------------------------------
32 
33 const String16 sAccessSurfaceFlinger("android.permission.ACCESS_SURFACE_FLINGER");
34 
35 // ---------------------------------------------------------------------------
36 
Client(const sp<SurfaceFlinger> & flinger)37 Client::Client(const sp<SurfaceFlinger>& flinger)
38     : Client(flinger, nullptr)
39 {
40 }
41 
Client(const sp<SurfaceFlinger> & flinger,const sp<Layer> & parentLayer)42 Client::Client(const sp<SurfaceFlinger>& flinger, const sp<Layer>& parentLayer)
43     : mFlinger(flinger),
44       mParentLayer(parentLayer)
45 {
46 }
47 
~Client()48 Client::~Client()
49 {
50     // We need to post a message to remove our remaining layers rather than
51     // do so directly by acquiring the SurfaceFlinger lock. If we were to
52     // attempt to directly call the lock it becomes effectively impossible
53     // to use sp<Client> while holding the SF lock as descoping it could
54     // then trigger a dead-lock.
55 
56     const size_t count = mLayers.size();
57     for (size_t i=0 ; i<count ; i++) {
58         sp<Layer> l = mLayers.valueAt(i).promote();
59         if (l == nullptr) {
60             continue;
61         }
62         mFlinger->postMessageAsync(new LambdaMessage([flinger = mFlinger, l]() {
63             flinger->removeLayer(l);
64         }));
65     }
66 }
67 
updateParent(const sp<Layer> & parentLayer)68 void Client::updateParent(const sp<Layer>& parentLayer) {
69     Mutex::Autolock _l(mLock);
70 
71     // If we didn't ever have a parent, then we must instead be
72     // relying on permissions and we never need a parent.
73     if (mParentLayer != nullptr) {
74         mParentLayer = parentLayer;
75     }
76 }
77 
getParentLayer(bool * outParentDied) const78 sp<Layer> Client::getParentLayer(bool* outParentDied) const {
79     Mutex::Autolock _l(mLock);
80     sp<Layer> parent = mParentLayer.promote();
81     if (outParentDied != nullptr) {
82         *outParentDied = (mParentLayer != nullptr && parent == nullptr);
83     }
84     return parent;
85 }
86 
initCheck() const87 status_t Client::initCheck() const {
88     return NO_ERROR;
89 }
90 
attachLayer(const sp<IBinder> & handle,const sp<Layer> & layer)91 void Client::attachLayer(const sp<IBinder>& handle, const sp<Layer>& layer)
92 {
93     Mutex::Autolock _l(mLock);
94     mLayers.add(handle, layer);
95 }
96 
detachLayer(const Layer * layer)97 void Client::detachLayer(const Layer* layer)
98 {
99     Mutex::Autolock _l(mLock);
100     // we do a linear search here, because this doesn't happen often
101     const size_t count = mLayers.size();
102     for (size_t i=0 ; i<count ; i++) {
103         if (mLayers.valueAt(i) == layer) {
104             mLayers.removeItemsAt(i, 1);
105             break;
106         }
107     }
108 }
getLayerUser(const sp<IBinder> & handle) const109 sp<Layer> Client::getLayerUser(const sp<IBinder>& handle) const
110 {
111     Mutex::Autolock _l(mLock);
112     sp<Layer> lbc;
113     wp<Layer> layer(mLayers.valueFor(handle));
114     if (layer != 0) {
115         lbc = layer.promote();
116         ALOGE_IF(lbc==0, "getLayerUser(name=%p) is dead", handle.get());
117     }
118     return lbc;
119 }
120 
121 
onTransact(uint32_t code,const Parcel & data,Parcel * reply,uint32_t flags)122 status_t Client::onTransact(
123     uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags)
124 {
125     // these must be checked
126      IPCThreadState* ipc = IPCThreadState::self();
127      const int pid = ipc->getCallingPid();
128      const int uid = ipc->getCallingUid();
129      const int self_pid = getpid();
130      // If we are called from another non root process without the GRAPHICS, SYSTEM, or ROOT
131      // uid we require the sAccessSurfaceFlinger permission.
132      // We grant an exception in the case that the Client has a "parent layer", as its
133      // effects will be scoped to that layer.
134      if (CC_UNLIKELY(pid != self_pid && uid != AID_GRAPHICS && uid != AID_SYSTEM && uid != 0)
135              && (getParentLayer() == nullptr)) {
136          // we're called from a different process, do the real check
137          if (!PermissionCache::checkCallingPermission(sAccessSurfaceFlinger))
138          {
139              ALOGE("Permission Denial: "
140                      "can't openGlobalTransaction pid=%d, uid<=%d", pid, uid);
141              return PERMISSION_DENIED;
142          }
143      }
144      return BnSurfaceComposerClient::onTransact(code, data, reply, flags);
145 }
146 
147 
createSurface(const String8 & name,uint32_t w,uint32_t h,PixelFormat format,uint32_t flags,const sp<IBinder> & parentHandle,int32_t windowType,int32_t ownerUid,sp<IBinder> * handle,sp<IGraphicBufferProducer> * gbp)148 status_t Client::createSurface(
149         const String8& name,
150         uint32_t w, uint32_t h, PixelFormat format, uint32_t flags,
151         const sp<IBinder>& parentHandle, int32_t windowType, int32_t ownerUid,
152         sp<IBinder>* handle,
153         sp<IGraphicBufferProducer>* gbp)
154 {
155     sp<Layer> parent = nullptr;
156     if (parentHandle != nullptr) {
157         auto layerHandle = reinterpret_cast<Layer::Handle*>(parentHandle.get());
158         parent = layerHandle->owner.promote();
159         if (parent == nullptr) {
160             return NAME_NOT_FOUND;
161         }
162     }
163     if (parent == nullptr) {
164         bool parentDied;
165         parent = getParentLayer(&parentDied);
166         // If we had a parent, but it died, we've lost all
167         // our capabilities.
168         if (parentDied) {
169             return NAME_NOT_FOUND;
170         }
171     }
172 
173     /*
174      * createSurface must be called from the GL thread so that it can
175      * have access to the GL context.
176      */
177     class MessageCreateLayer : public MessageBase {
178         SurfaceFlinger* flinger;
179         Client* client;
180         sp<IBinder>* handle;
181         sp<IGraphicBufferProducer>* gbp;
182         status_t result;
183         const String8& name;
184         uint32_t w, h;
185         PixelFormat format;
186         uint32_t flags;
187         sp<Layer>* parent;
188         int32_t windowType;
189         int32_t ownerUid;
190     public:
191         MessageCreateLayer(SurfaceFlinger* flinger,
192                 const String8& name, Client* client,
193                 uint32_t w, uint32_t h, PixelFormat format, uint32_t flags,
194                 sp<IBinder>* handle, int32_t windowType, int32_t ownerUid,
195                 sp<IGraphicBufferProducer>* gbp,
196                 sp<Layer>* parent)
197             : flinger(flinger), client(client),
198               handle(handle), gbp(gbp), result(NO_ERROR),
199               name(name), w(w), h(h), format(format), flags(flags),
200               parent(parent), windowType(windowType), ownerUid(ownerUid) {
201         }
202         status_t getResult() const { return result; }
203         virtual bool handler() {
204             result = flinger->createLayer(name, client, w, h, format, flags,
205                     windowType, ownerUid, handle, gbp, parent);
206             return true;
207         }
208     };
209 
210     sp<MessageBase> msg = new MessageCreateLayer(mFlinger.get(),
211             name, this, w, h, format, flags, handle,
212             windowType, ownerUid, gbp, &parent);
213     mFlinger->postMessageSync(msg);
214     return static_cast<MessageCreateLayer*>( msg.get() )->getResult();
215 }
216 
destroySurface(const sp<IBinder> & handle)217 status_t Client::destroySurface(const sp<IBinder>& handle) {
218     return mFlinger->onLayerRemoved(this, handle);
219 }
220 
clearLayerFrameStats(const sp<IBinder> & handle) const221 status_t Client::clearLayerFrameStats(const sp<IBinder>& handle) const {
222     sp<Layer> layer = getLayerUser(handle);
223     if (layer == nullptr) {
224         return NAME_NOT_FOUND;
225     }
226     layer->clearFrameStats();
227     return NO_ERROR;
228 }
229 
getLayerFrameStats(const sp<IBinder> & handle,FrameStats * outStats) const230 status_t Client::getLayerFrameStats(const sp<IBinder>& handle, FrameStats* outStats) const {
231     sp<Layer> layer = getLayerUser(handle);
232     if (layer == nullptr) {
233         return NAME_NOT_FOUND;
234     }
235     layer->getFrameStats(outStats);
236     return NO_ERROR;
237 }
238 
239 // ---------------------------------------------------------------------------
240 }; // namespace android
241