1 /*
2  * Copyright (c) 2021-2023 Huawei Device Co., Ltd.
3  * Licensed under the Apache License, Version 2.0 (the "License");
4  * you may not use this file except in compliance with the License.
5  * You may obtain a copy of the License at
6  *
7  *     http://www.apache.org/licenses/LICENSE-2.0
8  *
9  * Unless required by applicable law or agreed to in writing, software
10  * distributed under the License is distributed on an "AS IS" BASIS,
11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12  * See the License for the specific language governing permissions and
13  * limitations under the License.
14  */
15 
16 #include "hdi_netlink_monitor.h"
17 #include <arpa/inet.h>
18 #include <netinet/in.h>
19 #include <sys/socket.h>
20 #include <linux/netlink.h>
21 #include "hdi_session.h"
22 
23 namespace OHOS {
24 namespace HDI {
25 namespace DISPLAY {
HdiNetLinkMonitor()26 HdiNetLinkMonitor::HdiNetLinkMonitor()
27 {
28     DISPLAY_LOGD();
29 }
30 
Init()31 int HdiNetLinkMonitor::Init()
32 {
33     DISPLAY_LOGD();
34     mThread = std::make_unique<std::thread>(std::bind(&HdiNetLinkMonitor::MonitorThread, this));
35     mThread->detach();
36     mRunning = true;
37     return DISPLAY_SUCCESS;
38 }
39 
~HdiNetLinkMonitor()40 HdiNetLinkMonitor::~HdiNetLinkMonitor()
41 {
42     DISPLAY_LOGD();
43     if (mScoketFd >= 0) {
44         close(mScoketFd);
45     }
46 }
47 
ThreadInit()48 static int ThreadInit()
49 {
50     int ret;
51     int fd = -1;
52     const int32_t bufferSize = 1024;
53     struct sockaddr_nl snl;
54 
55     bzero(&snl, sizeof(struct sockaddr_nl));
56     snl.nl_family = AF_NETLINK;
57     snl.nl_pid = getpid();
58     snl.nl_groups = 1;
59     fd = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT);
60     DISPLAY_CHK_RETURN(fd < 0, DISPLAY_FAILURE, DISPLAY_LOGE("socket fail"));
61     ret = setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &bufferSize, sizeof(bufferSize));
62     if (ret == -1) {
63         DISPLAY_LOGE("setsockopt fail");
64         close(fd);
65         return -1;
66     }
67     ret = bind(fd, reinterpret_cast<struct sockaddr *>(&snl), sizeof(struct sockaddr_nl));
68     if (ret < 0) {
69         DISPLAY_LOGE("bind fail");
70         close(fd);
71         return -1;
72     }
73     return fd;
74 }
75 
ParseUeventMessage(const char * buf,uint32_t len)76 static void ParseUeventMessage(const char *buf, uint32_t len)
77 {
78     uint32_t num;
79 
80     for (num = 0; num < len;) {
81         const char *event = buf + num;
82         if (strcmp(event, "STATE=HDMI=0") == 0) {
83             HdiSession::GetInstance().HandleHotplug(false);
84             break;
85         } else if (strcmp(event, "STATE=HDMI=1") == 0) {
86             HdiSession::GetInstance().HandleHotplug(true);
87             break;
88         }
89         num += strlen(event) + 1;
90     }
91 }
92 
MonitorThread()93 void HdiNetLinkMonitor::MonitorThread()
94 {
95     constexpr int BUFFER_SIZE = 2048; /* buffer for the variables */
96     int len;
97     int fd = -1;
98 
99     fd = ThreadInit();
100     DISPLAY_CHK_RETURN_NOT_VALUE(fd < 0, DISPLAY_LOGE("socket fail"));
101     mScoketFd = fd;
102     while (mRunning) {
103         char buf[BUFFER_SIZE] = { 0 };
104         len = read(fd, &buf, sizeof(buf));
105         if (len < 0) {
106             DISPLAY_LOGE("read uevent message fail");
107             break;
108         }
109         ParseUeventMessage(buf, len);
110     }
111 }
112 } // DISPLAY
113 }  // HDI
114 }  // OHOS
115