xref: /openbmc/bmcweb/include/dbus_monitor.hpp (revision a14c9113)
1 #pragma once
2 #include "app.hpp"
3 #include "async_resp.hpp"
4 #include "dbus_singleton.hpp"
5 #include "openbmc_dbus_rest.hpp"
6 #include "websocket.hpp"
7 
8 #include <boost/container/flat_map.hpp>
9 #include <boost/container/flat_set.hpp>
10 #include <sdbusplus/bus/match.hpp>
11 #include <sdbusplus/message/types.hpp>
12 
13 #include <variant>
14 
15 namespace crow
16 {
17 namespace dbus_monitor
18 {
19 
20 struct DbusWebsocketSession
21 {
22     std::vector<std::unique_ptr<sdbusplus::bus::match_t>> matches;
23     boost::container::flat_set<std::string, std::less<>,
24                                std::vector<std::string>>
25         interfaces;
26 };
27 
28 using SessionMap = boost::container::flat_map<crow::websocket::Connection*,
29                                               DbusWebsocketSession>;
30 
31 // NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
32 static SessionMap sessions;
33 
34 inline int onPropertyUpdate(sd_bus_message* m, void* userdata,
35                             sd_bus_error* retError)
36 {
37     if (retError == nullptr || (sd_bus_error_is_set(retError) != 0))
38     {
39         BMCWEB_LOG_ERROR("Got sdbus error on match");
40         return 0;
41     }
42     crow::websocket::Connection* connection =
43         static_cast<crow::websocket::Connection*>(userdata);
44     auto thisSession = sessions.find(connection);
45     if (thisSession == sessions.end())
46     {
47         BMCWEB_LOG_ERROR("Couldn't find dbus connection {}",
48                          logPtr(connection));
49         return 0;
50     }
51     sdbusplus::message_t message(m);
52     nlohmann::json json;
53     json["event"] = message.get_member();
54     json["path"] = message.get_path();
55     if (strcmp(message.get_member(), "PropertiesChanged") == 0)
56     {
57         nlohmann::json data;
58         int r = openbmc_mapper::convertDBusToJSON("sa{sv}as", message, data);
59         if (r < 0)
60         {
61             BMCWEB_LOG_ERROR("convertDBusToJSON failed with {}", r);
62             return 0;
63         }
64         if (!data.is_array())
65         {
66             BMCWEB_LOG_ERROR("No data in PropertiesChanged signal");
67             return 0;
68         }
69 
70         // data is type sa{sv}as and is an array[3] of string, object, array
71         json["interface"] = data[0];
72         json["properties"] = data[1];
73     }
74     else if (strcmp(message.get_member(), "InterfacesAdded") == 0)
75     {
76         nlohmann::json data;
77         int r = openbmc_mapper::convertDBusToJSON("oa{sa{sv}}", message, data);
78         if (r < 0)
79         {
80             BMCWEB_LOG_ERROR("convertDBusToJSON failed with {}", r);
81             return 0;
82         }
83         nlohmann::json::array_t* arr = data.get_ptr<nlohmann::json::array_t*>();
84         if (arr == nullptr)
85         {
86             BMCWEB_LOG_ERROR("No data in InterfacesAdded signal");
87             return 0;
88         }
89         if (arr->size() < 2)
90         {
91             BMCWEB_LOG_ERROR("No data in InterfacesAdded signal");
92             return 0;
93         }
94 
95         nlohmann::json::object_t* obj =
96             (*arr)[1].get_ptr<nlohmann::json::object_t*>();
97         if (obj == nullptr)
98         {
99             BMCWEB_LOG_ERROR("No data in InterfacesAdded signal");
100             return 0;
101         }
102         // data is type oa{sa{sv}} which is an array[2] of string, object
103         for (const auto& entry : *obj)
104         {
105             auto it = thisSession->second.interfaces.find(entry.first);
106             if (it != thisSession->second.interfaces.end())
107             {
108                 json["interfaces"][entry.first] = entry.second;
109             }
110         }
111     }
112     else
113     {
114         BMCWEB_LOG_CRITICAL("message {} was unexpected", message.get_member());
115         return 0;
116     }
117 
118     connection->sendText(
119         json.dump(2, ' ', true, nlohmann::json::error_handler_t::replace));
120     return 0;
121 }
122 
123 inline void requestRoutes(App& app)
124 {
125     BMCWEB_ROUTE(app, "/subscribe")
126         .privileges({{"Login"}})
127         .websocket()
128         .onopen([](crow::websocket::Connection& conn) {
129             BMCWEB_LOG_DEBUG("Connection {} opened", logPtr(&conn));
130             sessions.try_emplace(&conn);
131         })
132         .onclose([](crow::websocket::Connection& conn, const std::string&) {
133             sessions.erase(&conn);
134         })
135         .onmessage([](crow::websocket::Connection& conn,
136                       const std::string& data, bool) {
137             const auto sessionPair = sessions.find(&conn);
138             if (sessionPair == sessions.end())
139             {
140                 conn.close("Internal error");
141             }
142             DbusWebsocketSession& thisSession = sessionPair->second;
143             BMCWEB_LOG_DEBUG("Connection {} received {}", logPtr(&conn), data);
144             nlohmann::json j = nlohmann::json::parse(data, nullptr, false);
145             if (j.is_discarded())
146             {
147                 BMCWEB_LOG_ERROR("Unable to parse json data for monitor");
148                 conn.close("Unable to parse json request");
149                 return;
150             }
151             nlohmann::json::iterator interfaces = j.find("interfaces");
152             if (interfaces != j.end())
153             {
154                 thisSession.interfaces.reserve(interfaces->size());
155                 for (auto& interface : *interfaces)
156                 {
157                     const std::string* str =
158                         interface.get_ptr<const std::string*>();
159                     if (str != nullptr)
160                     {
161                         thisSession.interfaces.insert(*str);
162                     }
163                 }
164             }
165 
166             nlohmann::json::iterator paths = j.find("paths");
167             if (paths == j.end())
168             {
169                 BMCWEB_LOG_ERROR("Unable to find paths in json data");
170                 conn.close("Unable to find paths in json data");
171                 return;
172             }
173 
174             size_t interfaceCount = thisSession.interfaces.size();
175             if (interfaceCount == 0)
176             {
177                 interfaceCount = 1;
178             }
179 
180             // These regexes derived on the rules here:
181             // https://dbus.freedesktop.org/doc/dbus-specification.html#message-protocol-names
182             static std::regex validPath("^/([A-Za-z0-9_]+/?)*$");
183             static std::regex validInterface(
184                 "^[A-Za-z_][A-Za-z0-9_]*(\\.[A-Za-z_][A-Za-z0-9_]*)+$");
185 
186             for (const auto& thisPath : *paths)
187             {
188                 const std::string* thisPathString =
189                     thisPath.get_ptr<const std::string*>();
190                 if (thisPathString == nullptr)
191                 {
192                     BMCWEB_LOG_ERROR("subscribe path isn't a string?");
193                     conn.close();
194                     return;
195                 }
196                 if (!std::regex_match(*thisPathString, validPath))
197                 {
198                     BMCWEB_LOG_ERROR("Invalid path name {}", *thisPathString);
199                     conn.close();
200                     return;
201                 }
202                 std::string propertiesMatchString =
203                     ("type='signal',"
204                      "interface='org.freedesktop.DBus.Properties',"
205                      "path_namespace='" +
206                      *thisPathString +
207                      "',"
208                      "member='PropertiesChanged'");
209                 // If interfaces weren't specified, add a single match for all
210                 // interfaces
211                 if (thisSession.interfaces.empty())
212                 {
213                     BMCWEB_LOG_DEBUG("Creating match {}",
214                                      propertiesMatchString);
215 
216                     thisSession.matches.emplace_back(
217                         std::make_unique<sdbusplus::bus::match_t>(
218                             *crow::connections::systemBus,
219                             propertiesMatchString, onPropertyUpdate, &conn));
220                 }
221                 else
222                 {
223                     // If interfaces were specified, add a match for each
224                     // interface
225                     for (const std::string& interface : thisSession.interfaces)
226                     {
227                         if (!std::regex_match(interface, validInterface))
228                         {
229                             BMCWEB_LOG_ERROR("Invalid interface name {}",
230                                              interface);
231                             conn.close();
232                             return;
233                         }
234                         std::string ifaceMatchString = propertiesMatchString;
235                         ifaceMatchString += ",arg0='";
236                         ifaceMatchString += interface;
237                         ifaceMatchString += "'";
238                         BMCWEB_LOG_DEBUG("Creating match {}", ifaceMatchString);
239                         thisSession.matches.emplace_back(
240                             std::make_unique<sdbusplus::bus::match_t>(
241                                 *crow::connections::systemBus, ifaceMatchString,
242                                 onPropertyUpdate, &conn));
243                     }
244                 }
245                 std::string objectManagerMatchString =
246                     ("type='signal',"
247                      "interface='org.freedesktop.DBus.ObjectManager',"
248                      "path_namespace='" +
249                      *thisPathString +
250                      "',"
251                      "member='InterfacesAdded'");
252                 BMCWEB_LOG_DEBUG("Creating match {}", objectManagerMatchString);
253                 thisSession.matches.emplace_back(
254                     std::make_unique<sdbusplus::bus::match_t>(
255                         *crow::connections::systemBus, objectManagerMatchString,
256                         onPropertyUpdate, &conn));
257             }
258         });
259 }
260 } // namespace dbus_monitor
261 } // namespace crow
262