xref: /openbmc/bmcweb/include/dbus_monitor.hpp (revision 57fce80e) 
1 #pragma once
2 #include <app.h>
3 #include <websocket.h>
4 
5 #include <async_resp.hpp>
6 #include <boost/container/flat_map.hpp>
7 #include <boost/container/flat_set.hpp>
8 #include <dbus_singleton.hpp>
9 #include <openbmc_dbus_rest.hpp>
10 #include <sdbusplus/bus/match.hpp>
11 #include <sdbusplus/message/types.hpp>
12 
13 #include <variant>
14 
15 namespace nlohmann
16 {
17 template <typename... Args>
18 struct adl_serializer<std::variant<Args...>>
19 {
20     static void to_json(json& j, const std::variant<Args...>& v)
21     {
22         std::visit([&](auto&& val) { j = val; }, v);
23     }
24 };
25 } // namespace nlohmann
26 
27 namespace crow
28 {
29 namespace dbus_monitor
30 {
31 
32 struct DbusWebsocketSession
33 {
34     std::vector<std::unique_ptr<sdbusplus::bus::match::match>> matches;
35     boost::container::flat_set<std::string> interfaces;
36 };
37 
38 static boost::container::flat_map<crow::websocket::Connection*,
39                                   DbusWebsocketSession>
40     sessions;
41 
42 inline int onPropertyUpdate(sd_bus_message* m, void* userdata,
43                             sd_bus_error* ret_error)
44 {
45     if (ret_error == nullptr || sd_bus_error_is_set(ret_error))
46     {
47         BMCWEB_LOG_ERROR << "Got sdbus error on match";
48         return 0;
49     }
50     crow::websocket::Connection* connection =
51         static_cast<crow::websocket::Connection*>(userdata);
52     auto thisSession = sessions.find(connection);
53     if (thisSession == sessions.end())
54     {
55         BMCWEB_LOG_ERROR << "Couldn't find dbus connection " << connection;
56         return 0;
57     }
58     sdbusplus::message::message message(m);
59     nlohmann::json j{{"event", message.get_member()},
60                      {"path", message.get_path()}};
61     if (strcmp(message.get_member(), "PropertiesChanged") == 0)
62     {
63         nlohmann::json data;
64         int r = openbmc_mapper::convertDBusToJSON("sa{sv}as", message, data);
65         if (r < 0)
66         {
67             BMCWEB_LOG_ERROR << "convertDBusToJSON failed with " << r;
68             return 0;
69         }
70         if (!data.is_array())
71         {
72             BMCWEB_LOG_ERROR << "No data in PropertiesChanged signal";
73             return 0;
74         }
75 
76         // data is type sa{sv}as and is an array[3] of string, object, array
77         j["interface"] = data[0];
78         j["properties"] = data[1];
79     }
80     else if (strcmp(message.get_member(), "InterfacesAdded") == 0)
81     {
82         nlohmann::json data;
83         int r = openbmc_mapper::convertDBusToJSON("oa{sa{sv}}", message, data);
84         if (r < 0)
85         {
86             BMCWEB_LOG_ERROR << "convertDBusToJSON failed with " << r;
87             return 0;
88         }
89 
90         if (!data.is_array())
91         {
92             BMCWEB_LOG_ERROR << "No data in InterfacesAdded signal";
93             return 0;
94         }
95 
96         // data is type oa{sa{sv}} which is an array[2] of string, object
97         for (auto& entry : data[1].items())
98         {
99             auto it = thisSession->second.interfaces.find(entry.key());
100             if (it != thisSession->second.interfaces.end())
101             {
102                 j["interfaces"][entry.key()] = entry.value();
103             }
104         }
105     }
106     else
107     {
108         BMCWEB_LOG_CRITICAL << "message " << message.get_member()
109                             << " was unexpected";
110         return 0;
111     }
112 
113     connection->sendText(j.dump());
114     return 0;
115 }
116 
117 inline void requestRoutes(App& app)
118 {
119     BMCWEB_ROUTE(app, "/subscribe")
120         .privileges({"Login"})
121         .websocket()
122         .onopen([&](crow::websocket::Connection& conn,
123                     std::shared_ptr<bmcweb::AsyncResp>) {
124             BMCWEB_LOG_DEBUG << "Connection " << &conn << " opened";
125             sessions[&conn] = DbusWebsocketSession();
126         })
127         .onclose([&](crow::websocket::Connection& conn, const std::string&) {
128             sessions.erase(&conn);
129         })
130         .onmessage([&](crow::websocket::Connection& conn,
131                        const std::string& data, bool) {
132             DbusWebsocketSession& thisSession = sessions[&conn];
133             BMCWEB_LOG_DEBUG << "Connection " << &conn << " received " << data;
134             nlohmann::json j = nlohmann::json::parse(data, nullptr, false);
135             if (j.is_discarded())
136             {
137                 BMCWEB_LOG_ERROR << "Unable to parse json data for monitor";
138                 conn.close("Unable to parse json request");
139                 return;
140             }
141             nlohmann::json::iterator interfaces = j.find("interfaces");
142             if (interfaces != j.end())
143             {
144                 thisSession.interfaces.reserve(interfaces->size());
145                 for (auto& interface : *interfaces)
146                 {
147                     const std::string* str =
148                         interface.get_ptr<const std::string*>();
149                     if (str != nullptr)
150                     {
151                         thisSession.interfaces.insert(*str);
152                     }
153                 }
154             }
155 
156             nlohmann::json::iterator paths = j.find("paths");
157             if (paths != j.end())
158             {
159                 size_t interfaceCount = thisSession.interfaces.size();
160                 if (interfaceCount == 0)
161                 {
162                     interfaceCount = 1;
163                 }
164                 // Reserve our matches upfront.  For each path there is 1 for
165                 // interfacesAdded, and InterfaceCount number for
166                 // PropertiesChanged
167                 thisSession.matches.reserve(thisSession.matches.size() +
168                                             paths->size() *
169                                                 (1U + interfaceCount));
170             }
171             std::string object_manager_match_string;
172             std::string properties_match_string;
173             std::string object_manager_interfaces_match_string;
174             // These regexes derived on the rules here:
175             // https://dbus.freedesktop.org/doc/dbus-specification.html#message-protocol-names
176             std::regex validPath("^/([A-Za-z0-9_]+/?)*$");
177             std::regex validInterface(
178                 "^[A-Za-z_][A-Za-z0-9_]*(\\.[A-Za-z_][A-Za-z0-9_]*)+$");
179 
180             for (const auto& thisPath : *paths)
181             {
182                 const std::string* thisPathString =
183                     thisPath.get_ptr<const std::string*>();
184                 if (thisPathString == nullptr)
185                 {
186                     BMCWEB_LOG_ERROR << "subscribe path isn't a string?";
187                     conn.close();
188                     return;
189                 }
190                 if (!std::regex_match(*thisPathString, validPath))
191                 {
192                     BMCWEB_LOG_ERROR << "Invalid path name " << *thisPathString;
193                     conn.close();
194                     return;
195                 }
196                 properties_match_string =
197                     ("type='signal',"
198                      "interface='org.freedesktop.DBus.Properties',"
199                      "path_namespace='" +
200                      *thisPathString +
201                      "',"
202                      "member='PropertiesChanged'");
203                 // If interfaces weren't specified, add a single match for all
204                 // interfaces
205                 if (thisSession.interfaces.size() == 0)
206                 {
207                     BMCWEB_LOG_DEBUG << "Creating match "
208                                      << properties_match_string;
209 
210                     thisSession.matches.emplace_back(
211                         std::make_unique<sdbusplus::bus::match::match>(
212                             *crow::connections::systemBus,
213                             properties_match_string, onPropertyUpdate, &conn));
214                 }
215                 else
216                 {
217                     // If interfaces were specified, add a match for each
218                     // interface
219                     for (const std::string& interface : thisSession.interfaces)
220                     {
221                         if (!std::regex_match(interface, validInterface))
222                         {
223                             BMCWEB_LOG_ERROR << "Invalid interface name "
224                                              << interface;
225                             conn.close();
226                             return;
227                         }
228                         std::string ifaceMatchString = properties_match_string +
229                                                        ",arg0='" + interface +
230                                                        "'";
231                         BMCWEB_LOG_DEBUG << "Creating match "
232                                          << ifaceMatchString;
233                         thisSession.matches.emplace_back(
234                             std::make_unique<sdbusplus::bus::match::match>(
235                                 *crow::connections::systemBus, ifaceMatchString,
236                                 onPropertyUpdate, &conn));
237                     }
238                 }
239                 object_manager_match_string =
240                     ("type='signal',"
241                      "interface='org.freedesktop.DBus.ObjectManager',"
242                      "path_namespace='" +
243                      *thisPathString +
244                      "',"
245                      "member='InterfacesAdded'");
246                 BMCWEB_LOG_DEBUG << "Creating match "
247                                  << object_manager_match_string;
248                 thisSession.matches.emplace_back(
249                     std::make_unique<sdbusplus::bus::match::match>(
250                         *crow::connections::systemBus,
251                         object_manager_match_string, onPropertyUpdate, &conn));
252             }
253         });
254 }
255 } // namespace dbus_monitor
256 } // namespace crow
257