1/*
2 * Copyright (C) 2010 The Android Open Source Project
3 * Copyright (C) 2012-2014, The Linux Foundation. All rights reserved.
4 *
5 * Not a Contribution, Apache license notifications and license are
6 * retained for attribution purposes only.
7
8 * Licensed under the Apache License, Version 2.0 (the "License");
9 * you may not use this file except in compliance with the License.
10 * You may obtain a copy of the License at
11 *
12 *      http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing, software
15 * distributed under the License is distributed on an "AS IS" BASIS,
16 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17 * See the License for the specific language governing permissions and
18 * limitations under the License.
19 */
20
21#include <fcntl.h>
22#include <stdint.h>
23#include <sys/types.h>
24#include <binder/Parcel.h>
25#include <binder/IBinder.h>
26#include <binder/IInterface.h>
27#include <binder/IPCThreadState.h>
28#include <utils/Errors.h>
29#include <private/android_filesystem_config.h>
30#include <IQService.h>
31
32#define QSERVICE_DEBUG 0
33
34using namespace android;
35using namespace qClient;
36
37// ---------------------------------------------------------------------------
38
39namespace qService {
40
41class BpQService : public BpInterface<IQService>
42{
43public:
44    BpQService(const sp<IBinder>& impl)
45        : BpInterface<IQService>(impl) {}
46
47    virtual void connect(const sp<IQClient>& client) {
48        ALOGD_IF(QSERVICE_DEBUG, "%s: connect client", __FUNCTION__);
49        Parcel data, reply;
50        data.writeInterfaceToken(IQService::getInterfaceDescriptor());
51        data.writeStrongBinder(IInterface::asBinder(client));
52        remote()->transact(CONNECT, data, &reply);
53    }
54
55    virtual android::status_t dispatch(uint32_t command, const Parcel* inParcel,
56            Parcel* outParcel) {
57        ALOGD_IF(QSERVICE_DEBUG, "%s: dispatch in:%p", __FUNCTION__, inParcel);
58        status_t err = (status_t) android::FAILED_TRANSACTION;
59        Parcel data;
60        Parcel *reply = outParcel;
61        data.writeInterfaceToken(IQService::getInterfaceDescriptor());
62        if (inParcel && inParcel->dataSize() > 0)
63            data.appendFrom(inParcel, 0, inParcel->dataSize());
64        err = remote()->transact(command, data, reply);
65        return err;
66    }
67};
68
69IMPLEMENT_META_INTERFACE(QService, "android.display.IQService");
70
71// ----------------------------------------------------------------------
72
73static void getProcName(int pid, char *buf, int size);
74
75status_t BnQService::onTransact(
76    uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags)
77{
78    ALOGD_IF(QSERVICE_DEBUG, "%s: code: %d", __FUNCTION__, code);
79    // IPC should be from certain processes only
80    IPCThreadState* ipc = IPCThreadState::self();
81    const int callerPid = ipc->getCallingPid();
82    const int callerUid = ipc->getCallingUid();
83    const int MAX_BUF_SIZE = 1024;
84    char callingProcName[MAX_BUF_SIZE] = {0};
85
86    getProcName(callerPid, callingProcName, MAX_BUF_SIZE);
87
88    const bool permission = (callerUid == AID_MEDIA ||
89            callerUid == AID_GRAPHICS ||
90            callerUid == AID_ROOT ||
91            callerUid == AID_SYSTEM);
92
93    if (code == CONNECT) {
94        CHECK_INTERFACE(IQService, data, reply);
95        if(callerUid != AID_GRAPHICS) {
96            ALOGE("display.qservice CONNECT access denied: \
97                    pid=%d uid=%d process=%s",
98                    callerPid, callerUid, callingProcName);
99            return PERMISSION_DENIED;
100        }
101        sp<IQClient> client =
102                interface_cast<IQClient>(data.readStrongBinder());
103        connect(client);
104        return NO_ERROR;
105    } else if (code > COMMAND_LIST_START && code < COMMAND_LIST_END) {
106        if(!permission) {
107            ALOGE("display.qservice access denied: command=%d\
108                  pid=%d uid=%d process=%s", code, callerPid,
109                  callerUid, callingProcName);
110            return PERMISSION_DENIED;
111        }
112        CHECK_INTERFACE(IQService, data, reply);
113        dispatch(code, &data, reply);
114        return NO_ERROR;
115    } else {
116        return BBinder::onTransact(code, data, reply, flags);
117    }
118}
119
120//Helper
121static void getProcName(int pid, char *buf, int size) {
122    int fd = -1;
123    snprintf(buf, size, "/proc/%d/cmdline", pid);
124    fd = open(buf, O_RDONLY);
125    if (fd < 0) {
126        strlcpy(buf, "Unknown", size);
127    } else {
128        ssize_t len = read(fd, buf, size - 1);
129        if (len >= 0)
130           buf[len] = 0;
131
132        close(fd);
133    }
134}
135
136}; // namespace qService
137