1 /**
2  * Copyright © 2016 IBM Corporation
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 "physical.hpp"
18 #include "sysfs.hpp"
19 
20 #include <CLI/CLI.hpp>
21 #include <boost/algorithm/string.hpp>
22 
23 #include <algorithm>
24 #include <iostream>
25 #include <string>
26 
27 struct LedDescr
28 {
29     std::string devicename;
30     std::string color;
31     std::string function;
32 };
33 
34 /** @brief parse LED name in sysfs
35  *  Parse sysfs LED name in format "devicename:colour:function"
36  *  or "devicename:colour" or "devicename" and sets corresponding
37  *  fields in LedDescr struct.
38  *
39  *  @param[in] name      - LED name in sysfs
40  *  @param[out] ledDescr - LED description
41  */
42 void getLedDescr(const std::string& name, LedDescr& ledDescr)
43 {
44     std::vector<std::string> words;
45     // FIXME: https://bugs.llvm.org/show_bug.cgi?id=41141
46     // NOLINTBEGIN(clang-analyzer-cplusplus.NewDeleteLeaks)
47     boost::split(words, name, boost::is_any_of(":"));
48     // NOLINTEND(clang-analyzer-cplusplus.NewDeleteLeaks)
49     try
50     {
51         ledDescr.devicename = words.at(0);
52         ledDescr.color = words.at(1);
53         ledDescr.function = words.at(2);
54     }
55     catch (const std::out_of_range&)
56     {
57         return;
58     }
59 }
60 
61 /** @brief generates LED DBus name from LED description
62  *
63  *  @param[in] name      - LED description
64  *  @return              - DBus LED name
65  */
66 std::string getDbusName(const LedDescr& ledDescr)
67 {
68     std::vector<std::string> words;
69     words.emplace_back(ledDescr.devicename);
70     if (!ledDescr.function.empty())
71     {
72         words.emplace_back(ledDescr.function);
73     }
74     if (!ledDescr.color.empty())
75     {
76         words.emplace_back(ledDescr.color);
77     }
78     return boost::join(words, "_");
79 }
80 
81 int main(int argc, char** argv)
82 {
83     namespace fs = std::filesystem;
84     static constexpr auto busParent = "xyz.openbmc_project.LED.Controller";
85     static constexpr auto objParent = "/xyz/openbmc_project/led/physical";
86     static constexpr auto devParent = "/sys/class/leds/";
87 
88     CLI::App app{"Control and Drive the physical LEDs"};
89 
90     // Read arguments.
91     std::string path{};
92     app.add_option("-p,--path", path,
93                    "absolute path of LED in sysfs; like /sys/class/leds/<name>")
94         ->required();
95 
96     // Parse out Path argument.
97     try
98     {
99         app.parse(argc, argv);
100     }
101     catch (const CLI::Error& e)
102     {
103         return app.exit(e);
104     }
105 
106     // If the LED has a hyphen in the name like: "one-two", then it gets passed
107     // as /one/two/ as opposed to /one-two to the service file. There is a
108     // change needed in systemd to solve this issue and hence putting in this
109     // work-around.
110 
111     // Since this application always gets invoked as part of a udev rule,
112     // it is always guaranteed to get /sys/class/leds/one/two
113     // and we can go beyond leds/ to get the actual LED name.
114     // Refer: systemd/systemd#5072
115 
116     // On an error, this throws an exception and terminates.
117     auto name = path.substr(strlen(devParent));
118 
119     // LED names may have a hyphen and that would be an issue for
120     // dbus paths and hence need to convert them to underscores.
121     std::replace(name.begin(), name.end(), '/', '-');
122     path = devParent + name;
123 
124     // Convert to lowercase just in case some are not and that
125     // we follow lowercase all over
126     std::transform(name.begin(), name.end(), name.begin(), ::tolower);
127 
128     // LED names may have a hyphen and that would be an issue for
129     // dbus paths and hence need to convert them to underscores.
130     std::replace(name.begin(), name.end(), '-', '_');
131 
132     // Convert LED name in sysfs into DBus name
133     LedDescr ledDescr;
134     getLedDescr(name, ledDescr);
135 
136     name = getDbusName(ledDescr);
137 
138     // Unique bus name representing a single LED.
139     auto busName = std::string(busParent) + '.' + name;
140     auto objPath = std::string(objParent) + '/' + name;
141 
142     // Get a handle to system dbus.
143     auto bus = sdbusplus::bus::new_default();
144 
145     sdbusplus::server::manager_t manager{bus, objPath.c_str()};
146 
147     // Create the Physical LED objects for directing actions.
148     // Need to save this else sdbusplus destructor will wipe this off.
149     phosphor::led::SysfsLed sled{fs::path(path)};
150     phosphor::led::Physical led(bus, objPath, sled, ledDescr.color);
151 
152     /** @brief Claim the bus */
153     bus.request_name(busName.c_str());
154 
155     /** @brief Wait for client requests */
156     while (true)
157     {
158         // Handle dbus message / signals discarding unhandled
159         bus.process_discard();
160         bus.wait();
161     }
162     return 0;
163 }
164