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 "argument.hpp"
18 #include "physical.hpp"
19 #include "sysfs.hpp"
20 
21 #include <boost/algorithm/string.hpp>
22 
23 #include <algorithm>
24 #include <iostream>
25 #include <string>
26 
27 static void exitWithError(const char* err, char** argv)
28 {
29     phosphor::led::ArgumentParser::usage(argv);
30     std::cerr << std::endl;
31     std::cerr << "ERROR: " << err << std::endl;
32     exit(-1);
33 }
34 
35 struct LedDescr
36 {
37     std::string devicename;
38     std::string color;
39     std::string function;
40 };
41 
42 /** @brief parse LED name in sysfs
43  *  Parse sysfs LED name in format "devicename:colour:function"
44  *  or "devicename:colour" or "devicename" and sets corresponding
45  *  fields in LedDescr struct.
46  *
47  *  @param[in] name      - LED name in sysfs
48  *  @param[out] ledDescr - LED description
49  */
50 void getLedDescr(const std::string& name, LedDescr& ledDescr)
51 {
52     std::vector<std::string> words;
53     boost::split(words, name, boost::is_any_of(":"));
54     try
55     {
56         ledDescr.devicename = words.at(0);
57         ledDescr.color = words.at(1);
58         ledDescr.function = words.at(2);
59     }
60     catch (const std::out_of_range&)
61     {
62         return;
63     }
64 }
65 
66 /** @brief generates LED DBus name from LED description
67  *
68  *  @param[in] name      - LED description
69  *  @return              - DBus LED name
70  */
71 std::string getDbusName(const LedDescr& ledDescr)
72 {
73     std::vector<std::string> words;
74     words.emplace_back(ledDescr.devicename);
75     if (!ledDescr.function.empty())
76     {
77         words.emplace_back(ledDescr.function);
78     }
79     if (!ledDescr.color.empty())
80     {
81         words.emplace_back(ledDescr.color);
82     }
83     return boost::join(words, "_");
84 }
85 
86 int main(int argc, char** argv)
87 {
88     namespace fs = std::filesystem;
89     static constexpr auto busParent = "xyz.openbmc_project.LED.Controller";
90     static constexpr auto objParent = "/xyz/openbmc_project/led/physical";
91     static constexpr auto devParent = "/sys/class/leds/";
92 
93     // Read arguments.
94     auto options = phosphor::led::ArgumentParser(argc, argv);
95 
96     // FIXME: https://bugs.llvm.org/show_bug.cgi?id=41141
97     // NOLINTBEGIN(clang-analyzer-cplusplus.NewDeleteLeaks)
98 
99     // Parse out Path argument.
100     if (options["path"].empty())
101     {
102         exitWithError("Path not specified.", argv);
103     }
104 
105     auto path = options["path"];
106 
107     // If the LED has a hyphen in the name like: "one-two", then it gets passed
108     // as /one/two/ as opposed to /one-two to the service file. There is a
109     // change needed in systemd to solve this issue and hence putting in this
110     // work-around.
111 
112     // Since this application always gets invoked as part of a udev rule,
113     // it is always guaranteed to get /sys/class/leds/one/two
114     // and we can go beyond leds/ to get the actual LED name.
115     // Refer: systemd/systemd#5072
116 
117     // On an error, this throws an exception and terminates.
118     auto name = path.substr(strlen(devParent));
119 
120     // LED names may have a hyphen and that would be an issue for
121     // dbus paths and hence need to convert them to underscores.
122     std::replace(name.begin(), name.end(), '/', '-');
123     path = devParent + name;
124 
125     // Convert to lowercase just in case some are not and that
126     // we follow lowercase all over
127     std::transform(name.begin(), name.end(), name.begin(), ::tolower);
128 
129     // LED names may have a hyphen and that would be an issue for
130     // dbus paths and hence need to convert them to underscores.
131     std::replace(name.begin(), name.end(), '-', '_');
132 
133     // Convert LED name in sysfs into DBus name
134     LedDescr ledDescr;
135     getLedDescr(name, ledDescr);
136     // NOLINTEND(clang-analyzer-cplusplus.NewDeleteLeaks)
137     name = getDbusName(ledDescr);
138 
139     // Unique bus name representing a single LED.
140     auto busName = std::string(busParent) + '.' + name;
141     auto objPath = std::string(objParent) + '/' + name;
142 
143     // Get a handle to system dbus.
144     auto bus = sdbusplus::bus::new_default();
145 
146     sdbusplus::server::manager_t manager{bus, objPath.c_str()};
147 
148     // Create the Physical LED objects for directing actions.
149     // Need to save this else sdbusplus destructor will wipe this off.
150     phosphor::led::SysfsLed sled{fs::path(path)};
151     phosphor::led::Physical led(bus, objPath, sled, ledDescr.color);
152 
153     /** @brief Claim the bus */
154     bus.request_name(busName.c_str());
155 
156     /** @brief Wait for client requests */
157     while (true)
158     {
159         // Handle dbus message / signals discarding unhandled
160         bus.process_discard();
161         bus.wait();
162     }
163     return 0;
164 }
165