Merge pull request #3556 from rdica/SRV-directoryaddress

Provides SRV support for connecting to directories from client or server

Author: pljones

Jamulus.pro

@@ -1182,6 +1182,12 @@ contains(CONFIG, "disable_version_check") {
     DEFINES += DISABLE_VERSION_CHECK
 }
 
+# disable SRV resolution in DNS if requested (#3556)
+contains(CONFIG, "disable_srv_dns") {
+    message(The use of SRV records in DNS is disabled.)
+    DEFINES += DISABLE_SRV_DNS
+}
+
 # Enable formatting all code via `make clang_format`.
 # Note: When extending the list of file extensions or when adding new code directories,
 # be sure to update .github/workflows/coding-style-check.yml and .clang-format-ignore as well.

src/client.cpp

@@ -570,11 +570,7 @@ void CClient::SetRemoteChanPan ( const int iId, const float fPan )
 bool CClient::SetServerAddr ( QString strNAddr )
 {
     CHostAddress HostAddress;
-#ifdef CLIENT_NO_SRV_CONNECT
-    if ( NetworkUtil().ParseNetworkAddress ( strNAddr, HostAddress, bEnableIPv6 ) )
-#else
-    if ( NetworkUtil().ParseNetworkAddressWithSrvDiscovery ( strNAddr, HostAddress, bEnableIPv6 ) )
-#endif
+    if ( NetworkUtil::ParseNetworkAddress ( strNAddr, HostAddress, bEnableIPv6 ) )
     {
         // apply address to the channel
         Channel.SetAddress ( HostAddress );

src/clientdlg.cpp

@@ -588,12 +588,14 @@ CClientDlg::CClientDlg ( CClient*         pNCliP,
     // Send the request to two servers for redundancy if either or both of them
     // has a higher release version number, the reply will trigger the notification.
 
-    if ( NetworkUtil().ParseNetworkAddress ( UPDATECHECK1_ADDRESS, UpdateServerHostAddress, bEnableIPv6 ) )
+    // Don't use SRV resolution when resolving update servers.
+
+    if ( NetworkUtil::ParseNetworkAddressBare ( UPDATECHECK1_ADDRESS, UpdateServerHostAddress, bEnableIPv6 ) )
     {
         pClient->CreateCLServerListReqVerAndOSMes ( UpdateServerHostAddress );
     }
 
-    if ( NetworkUtil().ParseNetworkAddress ( UPDATECHECK2_ADDRESS, UpdateServerHostAddress, bEnableIPv6 ) )
+    if ( NetworkUtil::ParseNetworkAddressBare ( UPDATECHECK2_ADDRESS, UpdateServerHostAddress, bEnableIPv6 ) )
     {
         pClient->CreateCLServerListReqVerAndOSMes ( UpdateServerHostAddress );
     }

src/clientrpc.cpp

@@ -164,7 +164,9 @@ CClientRpc::CClientRpc ( CClient* pClient, CRpcServer* pRpcServer, QObject* pare
         }
 
         CHostAddress haDirectoryAddress;
-        if ( NetworkUtil().ParseNetworkAddress ( jsonDirectoryIp.toString(), haDirectoryAddress, false ) )
+
+        // Allow IPv4 only for communicating with Directories
+        if ( NetworkUtil::ParseNetworkAddress ( jsonDirectoryIp.toString(), haDirectoryAddress, false ) )
         {
             // send the request for the server list
             pClient->CreateCLReqServerListMes ( haDirectoryAddress );

src/connectdlg.cpp

@@ -318,13 +318,13 @@ void CConnectDlg::RequestServerList()
     }
     cbxDirectory->blockSignals ( false );
 
-    // Get the IP address of the directory server (using the ParseNetworAddress
+    // Get the IP address of the directory server (using the ParseNetworkAddress
     // function) when the connect dialog is opened, this seems to be the correct
     // time to do it. Note that in case of custom directories we
     // use iCustomDirectoryIndex as an index into the vector.
 
     // Allow IPv4 only for communicating with Directories
-    if ( NetworkUtil().ParseNetworkAddress (
+    if ( NetworkUtil::ParseNetworkAddress (
              NetworkUtil::GetDirectoryAddress ( pSettings->eDirectoryType, pSettings->vstrDirectoryAddress[pSettings->iCustomDirectoryIndex] ),
              haDirectoryAddress,
              false ) )
@@ -856,7 +856,8 @@ void CConnectDlg::OnTimerPing()
 
         // try to parse host address string which is stored as user data
         // in the server list item GUI control element
-        if ( NetworkUtil().ParseNetworkAddress ( pCurListViewItem->data ( LVC_NAME, Qt::UserRole ).toString(), haServerAddress, bEnableIPv6 ) )
+        // the data to be parsed is just IP:port, so no SRV discovery is needed
+        if ( NetworkUtil::ParseNetworkAddressBare ( pCurListViewItem->data ( LVC_NAME, Qt::UserRole ).toString(), haServerAddress, bEnableIPv6 ) )
         {
             // if address is valid, send ping message using a new thread
 #if QT_VERSION >= QT_VERSION_CHECK( 6, 0, 0 )

src/global.h

@@ -96,8 +96,8 @@ LED bar:      lbr
 #define MAX_DELAY_PANNING_SAMPLES 64
 
 // default server address and port numbers
-#define DEFAULT_QOS_NUMBER            128 // CS4 (Quality of Service)
-#define DEFAULT_SERVER_ADDRESS        "anygenre1.jamulus.io"
+#define DEFAULT_QOS_NUMBER            128                          // CS4 (Quality of Service)
+#define DEFAULT_SERVER_ADDRESS        "anygenre1.jamulus.io:22124" // default port explicit to avoid unneeded SRV lookup
 #define DEFAULT_PORT_NUMBER           22124
 #define CENTSERV_ANY_GENRE2           "anygenre2.jamulus.io:22224"
 #define CENTSERV_ANY_GENRE3           "anygenre3.jamulus.io:22624"

src/serverdlg.cpp

@@ -482,12 +482,14 @@ CServerDlg::CServerDlg ( CServer* pNServP, CServerSettings* pNSetP, const bool b
     // Send the request to two servers for redundancy if either or both of them
     // has a higher release version number, the reply will trigger the notification.
 
-    if ( NetworkUtil().ParseNetworkAddress ( UPDATECHECK1_ADDRESS, UpdateServerHostAddress, pServer->IsIPv6Enabled() ) )
+    // Don't use SRV resolution when resolving update servers.
+
+    if ( NetworkUtil::ParseNetworkAddressBare ( UPDATECHECK1_ADDRESS, UpdateServerHostAddress, pServer->IsIPv6Enabled() ) )
     {
         pServer->CreateCLServerListReqVerAndOSMes ( UpdateServerHostAddress );
     }
 
-    if ( NetworkUtil().ParseNetworkAddress ( UPDATECHECK2_ADDRESS, UpdateServerHostAddress, pServer->IsIPv6Enabled() ) )
+    if ( NetworkUtil::ParseNetworkAddressBare ( UPDATECHECK2_ADDRESS, UpdateServerHostAddress, pServer->IsIPv6Enabled() ) )
     {
         pServer->CreateCLServerListReqVerAndOSMes ( UpdateServerHostAddress );
     }

src/serverlist.cpp

@@ -805,7 +805,9 @@ bool CServerListManager::Load()
             continue;
         }
 
-        NetworkUtil::ParseNetworkAddress ( slLine[0], haServerHostAddr, bEnableIPv6 );
+        // This uses ParseNetworkAddressBare because it is just parsing ip:host that was saved to the file.
+        // Therefore no SRV lookup is appropriate.
+        NetworkUtil::ParseNetworkAddressBare ( slLine[0], haServerHostAddr, bEnableIPv6 );
         int iIdx = IndexOf ( haServerHostAddr );
         if ( iIdx != INVALID_INDEX )
         {
@@ -969,13 +971,23 @@ void CServerListManager::SetRegistered ( const bool bIsRegister )
         return;
     }
 
+    // It is very important to unlock the Mutex before doing address resolution,
+    // so that the event loop can run and any other timers that need the mutex
+    // can obtain it. Otherwise there is the possibility of deadlock when doing
+    // the SRV lookup, if another timer fires that needs the same mutex.
+    locker.unlock();
+
     // get the correct directory address
     // Note that we always have to parse the server address again since if
     // it is an URL of a dynamic IP address, the IP address might have
     // changed in the meanwhile.
     // Allow IPv4 only for communicating with Directories
+    // Use SRV DNS discovery for directory connections, fallback to A/AAAA if none.
     const QString strNetworkAddress      = NetworkUtil::GetDirectoryAddress ( DirectoryType, strDirectoryAddress );
-    const bool    bDirectoryAddressValid = NetworkUtil().ParseNetworkAddress ( strNetworkAddress, DirectoryAddress, false );
+    const bool    bDirectoryAddressValid = NetworkUtil::ParseNetworkAddress ( strNetworkAddress, DirectoryAddress, false );
+
+    // lock the mutex again now that the address has been resolved.
+    locker.relock();
 
     if ( bIsRegister )
     {

src/util.cpp

@@ -750,7 +750,7 @@ bool NetworkUtil::ParseNetworkAddressString ( QString strAddress, QHostAddress&
     return false;
 }
 
-#ifndef CLIENT_NO_SRV_CONNECT
+#ifndef DISABLE_SRV_DNS
 bool NetworkUtil::ParseNetworkAddressSrv ( QString strAddress, CHostAddress& HostAddress, bool bEnableIPv6 )
 {
     // init requested host address with invalid address first
@@ -806,20 +806,22 @@ bool NetworkUtil::ParseNetworkAddressSrv ( QString strAddress, CHostAddress& Hos
     }
     return false;
 }
+#endif
 
-bool NetworkUtil::ParseNetworkAddressWithSrvDiscovery ( QString strAddress, CHostAddress& HostAddress, bool bEnableIPv6 )
+bool NetworkUtil::ParseNetworkAddress ( QString strAddress, CHostAddress& HostAddress, bool bEnableIPv6 )
 {
+#ifndef DISABLE_SRV_DNS
     // Try SRV-based discovery first:
     if ( ParseNetworkAddressSrv ( strAddress, HostAddress, bEnableIPv6 ) )
     {
         return true;
     }
+#endif
     // Try regular connect via plain IP or host name lookup (A/AAAA):
-    return ParseNetworkAddress ( strAddress, HostAddress, bEnableIPv6 );
+    return ParseNetworkAddressBare ( strAddress, HostAddress, bEnableIPv6 );
 }
-#endif
 
-bool NetworkUtil::ParseNetworkAddress ( QString strAddress, CHostAddress& HostAddress, bool bEnableIPv6 )
+bool NetworkUtil::ParseNetworkAddressBare ( QString strAddress, CHostAddress& HostAddress, bool bEnableIPv6 )
 {
     QHostAddress InetAddr;
     unsigned int iNetPort = DEFAULT_PORT_NUMBER;

src/util.h

@@ -53,7 +53,7 @@
 #include <QElapsedTimer>
 #include <QTextBoundaryFinder>
 #include <QTimer>
-#ifndef CLIENT_NO_SRV_CONNECT
+#ifndef DISABLE_SRV_DNS
 #    include <QDnsLookup>
 #endif
 #ifndef _WIN32
@@ -1055,11 +1055,11 @@ class NetworkUtil
 public:
     static bool ParseNetworkAddressString ( QString strAddress, QHostAddress& InetAddr, bool bEnableIPv6 );
 
-#ifndef CLIENT_NO_SRV_CONNECT
+#ifndef DISABLE_SRV_DNS
     static bool ParseNetworkAddressSrv ( QString strAddress, CHostAddress& HostAddress, bool bEnableIPv6 );
-    static bool ParseNetworkAddressWithSrvDiscovery ( QString strAddress, CHostAddress& HostAddress, bool bEnableIPv6 );
 #endif
     static bool ParseNetworkAddress ( QString strAddress, CHostAddress& HostAddress, bool bEnableIPv6 );
+    static bool ParseNetworkAddressBare ( QString strAddress, CHostAddress& HostAddress, bool bEnableIPv6 );
 
     static QString      FixAddress ( const QString& strAddress );
     static CHostAddress GetLocalAddress();