RFC: Add method to pass arbitrary client system info

client/client_settings.hpp

@@ -24,6 +24,7 @@
 
 // standard headers
 #include <string>
+#include <chrono>
 
 
 
@@ -73,10 +74,24 @@ struct ClientSettings
         std::string filter{"*:info"};
     };
 
+    struct SystemInfo
+    {
+        enum class Mode
+        {
+            file,
+            script,
+            none
+        };
+        Mode mode{Mode::none};
+        std::string path;
+        int interval_secs;
+    };
+
     size_t instance{1};
     std::string host_id;
 
     Server server;
     Player player;
     Logging logging;
+    SystemInfo systemInfo;
 };

client/controller.cpp

@@ -64,20 +64,25 @@
 #include "common/snap_exception.hpp"
 #include "time_provider.hpp"
 
+#include <boost/process.hpp>
+
 // standard headers
 #include <algorithm>
 #include <iostream>
 #include <memory>
 #include <string>
+#include <chrono>
 
 using namespace std;
 using namespace player;
 
+namespace bp = boost::process;
+
 static constexpr auto LOG_TAG = "Controller";
 static constexpr auto TIME_SYNC_INTERVAL = 1s;
 
 Controller::Controller(boost::asio::io_context& io_context, const ClientSettings& settings) //, std::unique_ptr<MetadataAdapter> meta)
-    : io_context_(io_context), timer_(io_context), settings_(settings), stream_(nullptr), decoder_(nullptr), player_(nullptr),
+    : io_context_(io_context), timer_(io_context), systemInfoTimer_(io_context), settings_(settings), stream_(nullptr), decoder_(nullptr), player_(nullptr),
       serverSettings_(nullptr) // meta_(std::move(meta)),
 {
 }
@@ -304,6 +309,90 @@ void Controller::sendTimeSyncMessage(int quick_syncs)
     });
 }
 
+void Controller::sendSystemInfoMessage()
+{
+    auto data = getSystemInfo();
+    if (data != nullptr)
+    {
+        auto sysInfo = std::make_shared<msg::ClientSystemInfo>();
+        sysInfo->msg = data;
+
+        LOG(TRACE, LOG_TAG) << "Sending system info: " << sysInfo->msg.dump() << "\n";
+        clientConnection_->send(sysInfo,
+                                [this](const boost::system::error_code& ec)
+                                {
+            if (ec)
+            {
+                LOG(ERROR, LOG_TAG) << "Failed to send client system info, error: " << ec.message() << "\n";
+                reconnect();
+                return;
+            }
+        });
+    }
+    auto interval = std::chrono::seconds(settings_.systemInfo.interval_secs);
+    systemInfoTimer_.expires_after(interval);
+    systemInfoTimer_.async_wait(
+        [this](const boost::system::error_code& ec)
+        {
+        if (!ec)
+        {
+            sendSystemInfoMessage();
+        }
+    });
+}
+
+json Controller::getSystemInfo()
+{
+
+    if (settings_.systemInfo.mode == ClientSettings::SystemInfo::Mode::script)
+    {
+        try
+        {
+            bp::ipstream istream;
+            auto ret = bp::system(settings_.systemInfo.path, bp::std_out > istream);
+            if (ret != 0)
+            {
+                LOG(ERROR, LOG_TAG)
+                    << "System info process returned with exit code "
+                    << ret  << std::endl;
+                return nullptr;
+            }
+            return json::parse(istream);
+        }
+        catch (const std::exception& e)
+        {
+            LOG(ERROR, LOG_TAG)
+                << "Unable to read system info from process ("
+                << settings_.systemInfo.path
+                << "): "
+                << e.what() << std::endl;
+            return nullptr;
+        }
+    }
+
+    if (settings_.systemInfo.mode == ClientSettings::SystemInfo::Mode::file)
+    {
+        try
+        {
+            ifstream fJson(settings_.systemInfo.path);
+            stringstream buffer;
+            buffer << fJson.rdbuf();
+            return json::parse(buffer.str());
+        }
+        catch (const std::exception& e)
+        {
+            LOG(ERROR, LOG_TAG)
+                << "Unable to read system info file ("
+                << settings_.systemInfo.path
+                << "): "
+                << e.what() << std::endl;
+            return nullptr;
+        }
+    }
+
+    return nullptr;
+}
+
 void Controller::browseMdns(const MdnsHandler& handler)
 {
 #if defined(HAS_AVAHI) || defined(HAS_BONJOUR)
@@ -382,6 +471,7 @@ void Controller::start()
 void Controller::reconnect()
 {
     timer_.cancel();
+    systemInfoTimer_.cancel();
     clientConnection_->disconnect();
     player_.reset();
     stream_.reset();
@@ -431,6 +521,11 @@ void Controller::worker()
 
             // Do initial time sync with the server
             sendTimeSyncMessage(50);
+            // start system info updates, if configured
+            if (settings_.systemInfo.mode != ClientSettings::SystemInfo::Mode::none)
+            {
+                sendSystemInfoMessage();
+            }
             // Start receiver loop
             getNextMessage();
         }

client/controller.hpp

@@ -59,9 +59,12 @@ class Controller
 
     void getNextMessage();
     void sendTimeSyncMessage(int quick_syncs);
+    void sendSystemInfoMessage();
+    json getSystemInfo();
 
     boost::asio::io_context& io_context_;
     boost::asio::steady_timer timer_;
+    boost::asio::steady_timer systemInfoTimer_;
     ClientSettings settings_;
     SampleFormat sampleFormat_;
     std::unique_ptr<ClientConnection> clientConnection_;

client/snapclient.cpp

@@ -179,6 +179,10 @@ int main(int argc, char** argv)
 #endif
         mixer_mode = op.add<Value<string>>("", "mixer", mixers + "|none|?[:<options>]", "software");
 
+        // system info
+        auto sysInfo = op.add<Value<string>>("", "sysinfo", "source for JSON-formatted system infomation [file:<filename>,script:<executable>]", "none");
+        op.add<Value<int>>("", "sysinfo-interval", "interval in seconds between system info updates", 10, &settings.systemInfo.interval_secs);
+
 // daemon settings
 #ifdef HAS_DAEMON
         int processPriority(-3);
@@ -427,6 +431,22 @@ int main(int argc, char** argv)
         else
             throw SnapException("Mixer mode not supported: " + mode);
 
+        string sysInfoMode = utils::string::split_left(sysInfo->value(), ':', settings.systemInfo.path);
+        if (sysInfoMode == "none")
+            settings.systemInfo.mode = ClientSettings::SystemInfo::Mode::none;
+        else if (sysInfoMode == "file")
+            settings.systemInfo.mode = ClientSettings::SystemInfo::Mode::file;
+        else if (sysInfoMode == "script")
+            settings.systemInfo.mode = ClientSettings::SystemInfo::Mode::script;
+        else
+            throw SnapException("System info mode not supported: " + sysInfoMode);
+
+        if (settings.systemInfo.interval_secs < 1)
+        {
+            LOG(ERROR, LOG_TAG) << "System info interval too low, setting to default value (10 seconds)\n";
+            settings.systemInfo.interval_secs = 10;
+        }
+
         boost::asio::io_context io_context;
         // Construct a signal set registered for process termination.
         boost::asio::signal_set signals(io_context, SIGHUP, SIGINT, SIGTERM);

common/message/client_system_info.hpp

@@ -0,0 +1,45 @@
+/***
+    This file is part of snapcast
+    Copyright (C) 2014-2022  Johannes Pohl
+    Copyright (C) 2024  Marcus Weseloh
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#ifndef MESSAGE_CLIENT_SYSTEM_INFO_HPP
+#define MESSAGE_CLIENT_SYSTEM_INFO_HPP
+
+// local headers
+#include "json_message.hpp"
+
+
+namespace msg
+{
+
+// Client system information sent from client to server.
+// This message can contrain arbitrary JSON data.
+class ClientSystemInfo : public JsonMessage
+{
+public:
+    ClientSystemInfo() : JsonMessage(message_type::kClientSystemInfo)
+    {
+    }
+
+    ~ClientSystemInfo() override = default;
+};
+} // namespace msg
+
+
+#endif
+

common/message/factory.hpp

@@ -19,6 +19,7 @@
 #pragma once
 
 // local headers
+#include "client_system_info.hpp"
 #include "client_info.hpp"
 #include "codec_header.hpp"
 #include "hello.hpp"
@@ -76,6 +77,8 @@ static std::unique_ptr<BaseMessage> createMessage(const BaseMessage& base_messag
             return createMessage<PcmChunk>(base_message, buffer);
         case message_type::kClientInfo:
             return createMessage<ClientInfo>(base_message, buffer);
+        case message_type::kClientSystemInfo:
+            return createMessage<ClientSystemInfo>(base_message, buffer);
         default:
             return nullptr;
     }

common/message/message.hpp

@@ -63,9 +63,10 @@ enum class message_type : uint16_t
     kHello = 5,
     // kStreamTags = 6,
     kClientInfo = 7,
+    kClientSystemInfo = 8,
 
     kFirst = kBase,
-    kLast = kClientInfo
+    kLast = kClientSystemInfo
 };
 
 static std::ostream& operator<<(std::ostream& os, const message_type& msg_type)
@@ -93,6 +94,9 @@ static std::ostream& operator<<(std::ostream& os, const message_type& msg_type)
         case message_type::kClientInfo:
             os << "ClientInfo";
             break;
+        case message_type::kClientSystemInfo:
+            os << "ClientSystemInfo";
+            break;
         default:
             os << "Unknown";
     }

server/config.hpp

@@ -235,6 +235,10 @@ struct ClientInfo
         lastSeen.tv_sec = jGet<int32_t>(j["lastSeen"], "sec", 0);
         lastSeen.tv_usec = jGet<int32_t>(j["lastSeen"], "usec", 0);
         connected = jGet<bool>(j, "connected", true);
+        if (j.contains("systemInfo"))
+        {
+            systemInfo = j["systemInfo"].template get<json>();
+        }
     }
 
     json toJson()
@@ -247,6 +251,7 @@ struct ClientInfo
         j["lastSeen"]["sec"] = lastSeen.tv_sec;
         j["lastSeen"]["usec"] = lastSeen.tv_usec;
         j["connected"] = connected;
+        j["systemInfo"] = systemInfo;
         return j;
     }
 
@@ -256,6 +261,7 @@ struct ClientInfo
     ClientConfig config;
     timeval lastSeen;
     bool connected;
+    json systemInfo;
 };
 
 

server/server.cpp

@@ -22,6 +22,7 @@
 // local headers
 #include "common/aixlog.hpp"
 #include "common/message/client_info.hpp"
+#include "common/message/client_system_info.hpp"
 #include "common/message/hello.hpp"
 #include "common/message/server_settings.hpp"
 #include "common/message/time.hpp"
@@ -763,6 +764,22 @@ void Server::onMessageReceived(StreamSession* streamSession, const msg::BaseMess
             "Client.OnVolumeChanged", jsonrpcpp::Parameter("id", streamSession->clientId, "volume", clientInfo->config.volume.toJson()));
         controlServer_->send(notification->to_json().dump());
     }
+    else if (baseMessage.type == message_type::kClientSystemInfo)
+    {
+        ClientInfoPtr clientInfo = Config::instance().getClientInfo(streamSession->clientId);
+        if (clientInfo == nullptr)
+        {
+            LOG(ERROR, LOG_TAG) << "client not found: " << streamSession->clientId << "\n";
+            return;
+        }
+        msg::ClientSystemInfo sysInfoMsg;
+        sysInfoMsg.deserialize(baseMessage, buffer);
+
+        clientInfo->systemInfo = sysInfoMsg.msg;
+        jsonrpcpp::notification_ptr notification = make_shared<jsonrpcpp::Notification>(
+            "Client.OnSystemInfoChanged", jsonrpcpp::Parameter("id", streamSession->clientId, "systemInfo", clientInfo->systemInfo));
+        controlServer_->send(notification->to_json().dump());
+    }
     else if (baseMessage.type == message_type::kHello)
     {
         msg::Hello helloMsg;