Added handling of multicast membership for PTP messages.

Limited PTP domain value to the range 0 - 127.

daemon/config.cpp

@@ -68,6 +68,8 @@ std::shared_ptr<Config> Config::parse(const std::string& filename) {
   if (ip::address_v4::from_string(config.rtp_mcast_base_.c_str()).to_ulong() ==
       INADDR_NONE)
     config.rtp_mcast_base_ = "239.1.0.1";
+  if (config.ptp_domain_ > 127)
+    config.ptp_domain_ = 0;
 
   auto [mac_addr, mac_str] = get_interface_mac(config.interface_name_);
   if (mac_str.empty()) {

daemon/http_server.cpp

@@ -137,6 +137,11 @@ bool HttpServer::start() {
   svr_.Post("/api/ptp/config", [this](const Request& req, Response& res) {
     try {
       PTPConfig ptpConfig = json_to_ptp_config(req.body);
+      auto ret = session_manager_->set_ptp_config(ptpConfig);
+      if (ret) {
+        set_error(ret, "failed to set ptp config", res);
+        return;
+      }
       Config config(*config_);
       config.set_ptp_domain(ptpConfig.domain);
       config.set_ptp_dscp(ptpConfig.dscp);
@@ -144,11 +149,6 @@ bool HttpServer::start() {
         set_error(500, "failed to save config", res);
         return;
       }
-      auto ret = session_manager_->set_ptp_config(ptpConfig);
-      if (ret) {
-        set_error(ret, "failed to set ptp config", res);
-        return;
-      }
       set_headers(res);
     } catch (const std::runtime_error& e) {
       set_error(400, e.what(), res);

daemon/scripts/ptp_master_start.sh

@@ -1 +1,4 @@
+# Note:
+# currently ptp4l disables IP_MULTICAST_LOOP, so sockets on the same host cannot receive ptp4l traffic.
+# Only exception is for lo network interface.
 sudo ptp4l -i $1 -m -l7 -E -S

daemon/session_manager.cpp

@@ -918,6 +918,11 @@ bool SessionManager::worker() {
 
   sap_.set_multicast_interface(config_->get_ip_addr_str());
 
+  // join PTP multicast address for specific domain
+  uint32_t ptp_addr = ip::address_v4::from_string(ptp_dflt_mcast_addr).to_ulong() +
+                      config_->get_ptp_domain();
+  igmp_.join(config_->get_ip_addr_str(), ip::address_v4(ptp_addr).to_string());
+
   while (running_) {
     // check if it's time to update the PTP status
     if (std::chrono::duration_cast<second_t> (clock_::now() - ptp_timepoint).count() > 
@@ -944,6 +949,7 @@ bool SessionManager::worker() {
         // update PTP clock status
         std::unique_lock ptp_lock(ptp_mutex_);
 
+	// update status
         ptp_status_.gmid = ptp_clock_id;
         ptp_status_.jitter = ptp_status.i32Jitter;
         std::string new_ptp_status;
@@ -967,9 +973,17 @@ bool SessionManager::worker() {
             (void)driver_->set_sample_rate(driver_->get_current_sample_rate());
           }
         }
-        // update config
-        ptp_config_.domain = ptp_config.ui8Domain;
-        ptp_config_.dscp = ptp_config.ui8DSCP;
+
+        // update PTP multicast join
+        uint32_t new_ptp_addr = ip::address_v4::from_string(ptp_dflt_mcast_addr).to_ulong() +
+                                ptp_config.ui8Domain;
+	if (new_ptp_addr != ptp_addr) {
+          // leave old PTP multicast address for specific domain
+          igmp_.leave(config_->get_ip_addr_str(), ip::address_v4(ptp_addr).to_string());
+	  ptp_addr = new_ptp_addr;
+          // join new PTP multicast address for specific domain
+          igmp_.join(config_->get_ip_addr_str(), ip::address_v4(ptp_addr).to_string());
+	}
       }
       ptp_interval = 10;
     }
@@ -1010,6 +1024,8 @@ bool SessionManager::worker() {
     // send deletion for this source
     sap_.deletion(static_cast<uint16_t>(msg_id_hash), addr, sdp);
   }
+  // leave PTP primary multicast
+  igmp_.leave(config_->get_ip_addr_str(), ip::address_v4(ptp_addr).to_string());
 
   return true;
 }

daemon/session_manager.hpp

@@ -147,6 +147,8 @@ class SessionManager {
   size_t process_sap();
 
  protected:
+  constexpr static const char ptp_dflt_mcast_addr[] = "224.0.1.129";
+
   std::string get_removed_source_sdp_(uint32_t id, uint32_t src_addr) const;
   std::string get_source_sdp_(uint32_t id, const StreamInfo& info) const;
   StreamSource get_source_(uint8_t id, const StreamInfo& info) const;
@@ -157,7 +159,10 @@ class SessionManager {
   // singleton, use create() to build
   SessionManager(std::shared_ptr<DriverManager> driver,
                  std::shared_ptr<Config> config)
-      : driver_(driver), config_(config){};
+      : driver_(driver), config_(config){
+    ptp_config_.domain = config->get_ptp_domain();
+    ptp_config_.dscp = config->get_ptp_dscp();
+  };
 
   std::shared_ptr<DriverManager> driver_;
   std::shared_ptr<Config> config_;

webui/src/PTP.js

@@ -95,7 +95,7 @@ class PTP extends Component {
           </tr>
           <tr>
             <th align="left"> <label>Domain</label> </th>
-             <th align="left"> <input type='number' min='0' max='255' className='input-number' value={this.state.domain} onChange={e => this.setState({domain: e.target.value, domainErr: !e.currentTarget.checkValidity()})} required/> </th>
+             <th align="left"> <input type='number' min='0' max='127' className='input-number' value={this.state.domain} onChange={e => this.setState({domain: e.target.value, domainErr: !e.currentTarget.checkValidity()})} required/> </th>
           </tr>
           <tr>
             <th align="left"> <label>DSCP</label> </th>