1 #include "watch.hpp"
2 
3 #include <sys/epoll.h>
4 #include <sys/inotify.h>
5 #include <unistd.h>
6 
7 #include <phosphor-logging/elog-errors.hpp>
8 #include <phosphor-logging/elog.hpp>
9 #include <phosphor-logging/lg2.hpp>
10 #include <sdeventplus/source/io.hpp>
11 #include <xyz/openbmc_project/Common/error.hpp>
12 
13 #include <array>
14 #include <cerrno>
15 #include <climits>
16 #include <cstdint>
17 #include <cstring>
18 #include <filesystem>
19 
20 namespace phosphor::certs
21 {
22 
23 using ::phosphor::logging::elog;
24 using ::sdbusplus::xyz::openbmc_project::Common::Error::InternalFailure;
25 namespace fs = std::filesystem;
26 
27 Watch::Watch(sdeventplus::Event& event, std::string& certFile, Callback cb) :
28     event(event), callback(std::move(cb))
29 {
30     // get parent directory of certificate file to watch
31     fs::path path = fs::path(certFile).parent_path();
32     try
33     {
34         if (!fs::exists(path))
35         {
36             fs::create_directories(path);
37         }
38     }
39     catch (const fs::filesystem_error& e)
40     {
41         lg2::error(
42             "Failed to create directory, ERR:{ERR}, DIRECTORY:{DIRECTORY}",
43             "ERR", e, "DIRECTORY", path);
44         elog<InternalFailure>();
45     }
46     watchDir = path;
47     watchFile = fs::path(certFile).filename();
48     startWatch();
49 }
50 
51 Watch::~Watch()
52 {
53     stopWatch();
54 }
55 
56 void Watch::startWatch()
57 {
58     // stop any existing watch
59     stopWatch();
60 
61     fd = inotify_init1(IN_NONBLOCK);
62     if (-1 == fd)
63     {
64         lg2::error("inotify_init1 failed: {ERR}", "ERR", std::strerror(errno));
65         elog<InternalFailure>();
66     }
67     wd = inotify_add_watch(fd, watchDir.c_str(), IN_CLOSE_WRITE);
68     if (-1 == wd)
69     {
70         close(fd);
71         lg2::error("inotify_add_watch failed, ERR:{ERR}, WATCH:{WATCH}", "ERR",
72                    std::strerror(errno), "WATCH", watchDir);
73         elog<InternalFailure>();
74     }
75 
76     ioPtr = std::make_unique<sdeventplus::source::IO>(
77         event, fd, EPOLLIN, [this](sdeventplus::source::IO&, int fd, uint32_t) {
78             constexpr int size = sizeof(struct inotify_event) + NAME_MAX + 1;
79             std::array<char, size> buffer{};
80             int length = read(fd, buffer.data(), buffer.size());
81             if (length >= static_cast<int>(sizeof(struct inotify_event)))
82             {
83                 struct inotify_event* notifyEvent =
84                     reinterpret_cast<struct inotify_event*>(&buffer[0]);
85                 if (notifyEvent->len)
86                 {
87                     if (watchFile == notifyEvent->name)
88                     {
89                         callback();
90                     }
91                 }
92             }
93             else
94             {
95                 lg2::error("Failed to read inotify event");
96             }
97         });
98 }
99 
100 void Watch::stopWatch()
101 {
102     if (-1 != fd)
103     {
104         if (-1 != wd)
105         {
106             inotify_rm_watch(fd, wd);
107         }
108         close(fd);
109     }
110     if (ioPtr)
111     {
112         ioPtr.reset();
113     }
114 }
115 
116 } // namespace phosphor::certs
117