xref: /openbmc/bmcweb/include/dbus_monitor.hpp (revision b5a76932eab7d40487ffb305cd745ec155813c4e)
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 crow
16 {
17 namespace dbus_monitor
18 {
19 
20 struct DbusWebsocketSession
21 {
22     std::vector<std::unique_ptr<sdbusplus::bus::match::match>> matches;
23     boost::container::flat_set<std::string> interfaces;
24 };
25 
26 static boost::container::flat_map<crow::websocket::Connection*,
27                                   DbusWebsocketSession>
28     sessions;
29 
30 inline int onPropertyUpdate(sd_bus_message* m, void* userdata,
31                             sd_bus_error* ret_error)
32 {
33     if (ret_error == nullptr || sd_bus_error_is_set(ret_error))
34     {
35         BMCWEB_LOG_ERROR << "Got sdbus error on match";
36         return 0;
37     }
38     crow::websocket::Connection* connection =
39         static_cast<crow::websocket::Connection*>(userdata);
40     auto thisSession = sessions.find(connection);
41     if (thisSession == sessions.end())
42     {
43         BMCWEB_LOG_ERROR << "Couldn't find dbus connection " << connection;
44         return 0;
45     }
46     sdbusplus::message::message message(m);
47     nlohmann::json j{{"event", message.get_member()},
48                      {"path", message.get_path()}};
49     if (strcmp(message.get_member(), "PropertiesChanged") == 0)
50     {
51         nlohmann::json data;
52         int r = openbmc_mapper::convertDBusToJSON("sa{sv}as", message, data);
53         if (r < 0)
54         {
55             BMCWEB_LOG_ERROR << "convertDBusToJSON failed with " << r;
56             return 0;
57         }
58         if (!data.is_array())
59         {
60             BMCWEB_LOG_ERROR << "No data in PropertiesChanged signal";
61             return 0;
62         }
63 
64         // data is type sa{sv}as and is an array[3] of string, object, array
65         j["interface"] = data[0];
66         j["properties"] = data[1];
67     }
68     else if (strcmp(message.get_member(), "InterfacesAdded") == 0)
69     {
70         nlohmann::json data;
71         int r = openbmc_mapper::convertDBusToJSON("oa{sa{sv}}", message, data);
72         if (r < 0)
73         {
74             BMCWEB_LOG_ERROR << "convertDBusToJSON failed with " << r;
75             return 0;
76         }
77 
78         if (!data.is_array())
79         {
80             BMCWEB_LOG_ERROR << "No data in InterfacesAdded signal";
81             return 0;
82         }
83 
84         // data is type oa{sa{sv}} which is an array[2] of string, object
85         for (auto& entry : data[1].items())
86         {
87             auto it = thisSession->second.interfaces.find(entry.key());
88             if (it != thisSession->second.interfaces.end())
89             {
90                 j["interfaces"][entry.key()] = entry.value();
91             }
92         }
93     }
94     else
95     {
96         BMCWEB_LOG_CRITICAL << "message " << message.get_member()
97                             << " was unexpected";
98         return 0;
99     }
100 
101     connection->sendText(j.dump());
102     return 0;
103 }
104 
105 inline void requestRoutes(App& app)
106 {
107     BMCWEB_ROUTE(app, "/subscribe")
108         .privileges({"Login"})
109         .websocket()
110         .onopen([&](crow::websocket::Connection& conn,
111                     const std::shared_ptr<bmcweb::AsyncResp>&) {
112             BMCWEB_LOG_DEBUG << "Connection " << &conn << " opened";
113             sessions[&conn] = DbusWebsocketSession();
114         })
115         .onclose([&](crow::websocket::Connection& conn, const std::string&) {
116             sessions.erase(&conn);
117         })
118         .onmessage([&](crow::websocket::Connection& conn,
119                        const std::string& data, bool) {
120             DbusWebsocketSession& thisSession = sessions[&conn];
121             BMCWEB_LOG_DEBUG << "Connection " << &conn << " received " << data;
122             nlohmann::json j = nlohmann::json::parse(data, nullptr, false);
123             if (j.is_discarded())
124             {
125                 BMCWEB_LOG_ERROR << "Unable to parse json data for monitor";
126                 conn.close("Unable to parse json request");
127                 return;
128             }
129             nlohmann::json::iterator interfaces = j.find("interfaces");
130             if (interfaces != j.end())
131             {
132                 thisSession.interfaces.reserve(interfaces->size());
133                 for (auto& interface : *interfaces)
134                 {
135                     const std::string* str =
136                         interface.get_ptr<const std::string*>();
137                     if (str != nullptr)
138                     {
139                         thisSession.interfaces.insert(*str);
140                     }
141                 }
142             }
143 
144             nlohmann::json::iterator paths = j.find("paths");
145             if (paths != j.end())
146             {
147                 size_t interfaceCount = thisSession.interfaces.size();
148                 if (interfaceCount == 0)
149                 {
150                     interfaceCount = 1;
151                 }
152                 // Reserve our matches upfront.  For each path there is 1 for
153                 // interfacesAdded, and InterfaceCount number for
154                 // PropertiesChanged
155                 thisSession.matches.reserve(thisSession.matches.size() +
156                                             paths->size() *
157                                                 (1U + interfaceCount));
158             }
159             std::string objectManagerMatchString;
160             std::string propertiesMatchString;
161             std::string objectManagerInterfacesMatchString;
162             // These regexes derived on the rules here:
163             // https://dbus.freedesktop.org/doc/dbus-specification.html#message-protocol-names
164             std::regex validPath("^/([A-Za-z0-9_]+/?)*$");
165             std::regex validInterface(
166                 "^[A-Za-z_][A-Za-z0-9_]*(\\.[A-Za-z_][A-Za-z0-9_]*)+$");
167 
168             for (const auto& thisPath : *paths)
169             {
170                 const std::string* thisPathString =
171                     thisPath.get_ptr<const std::string*>();
172                 if (thisPathString == nullptr)
173                 {
174                     BMCWEB_LOG_ERROR << "subscribe path isn't a string?";
175                     conn.close();
176                     return;
177                 }
178                 if (!std::regex_match(*thisPathString, validPath))
179                 {
180                     BMCWEB_LOG_ERROR << "Invalid path name " << *thisPathString;
181                     conn.close();
182                     return;
183                 }
184                 propertiesMatchString =
185                     ("type='signal',"
186                      "interface='org.freedesktop.DBus.Properties',"
187                      "path_namespace='" +
188                      *thisPathString +
189                      "',"
190                      "member='PropertiesChanged'");
191                 // If interfaces weren't specified, add a single match for all
192                 // interfaces
193                 if (thisSession.interfaces.size() == 0)
194                 {
195                     BMCWEB_LOG_DEBUG << "Creating match "
196                                      << propertiesMatchString;
197 
198                     thisSession.matches.emplace_back(
199                         std::make_unique<sdbusplus::bus::match::match>(
200                             *crow::connections::systemBus,
201                             propertiesMatchString, onPropertyUpdate, &conn));
202                 }
203                 else
204                 {
205                     // If interfaces were specified, add a match for each
206                     // interface
207                     for (const std::string& interface : thisSession.interfaces)
208                     {
209                         if (!std::regex_match(interface, validInterface))
210                         {
211                             BMCWEB_LOG_ERROR << "Invalid interface name "
212                                              << interface;
213                             conn.close();
214                             return;
215                         }
216                         std::string ifaceMatchString =
217                             propertiesMatchString + ",arg0='" + interface + "'";
218                         BMCWEB_LOG_DEBUG << "Creating match "
219                                          << ifaceMatchString;
220                         thisSession.matches.emplace_back(
221                             std::make_unique<sdbusplus::bus::match::match>(
222                                 *crow::connections::systemBus, ifaceMatchString,
223                                 onPropertyUpdate, &conn));
224                     }
225                 }
226                 objectManagerMatchString =
227                     ("type='signal',"
228                      "interface='org.freedesktop.DBus.ObjectManager',"
229                      "path_namespace='" +
230                      *thisPathString +
231                      "',"
232                      "member='InterfacesAdded'");
233                 BMCWEB_LOG_DEBUG << "Creating match "
234                                  << objectManagerMatchString;
235                 thisSession.matches.emplace_back(
236                     std::make_unique<sdbusplus::bus::match::match>(
237                         *crow::connections::systemBus, objectManagerMatchString,
238                         onPropertyUpdate, &conn));
239             }
240         });
241 }
242 } // namespace dbus_monitor
243 } // namespace crow
244