Allow combining socket activation and extra ports

The common use case is probably to only listem to the systemd provided
socket when using socket activation, but it might not be the only use
case. Make sure things can be combined if explicitly requested.

unix/x0vncserver/x0vncserver.cxx

@@ -116,9 +116,20 @@ static void CleanupSignalHandler(int /*sig*/)
   caughtSignal = true;
 }
 
+static bool hasSystemdListeners()
+{
 #ifdef HAVE_SYSTEMD_H
+  // This also returns true on errors, because we then assume we were
+  // meant to use systemd but failed somewhere
+  return sd_listen_fds(0) != 0;
+#else
+  return false;
+#endif
+}
+
 static int createSystemdListeners(std::list<SocketListener*> *listeners)
 {
+#ifdef HAVE_SYSTEMD_H
   int count = sd_listen_fds(0);
   if (count < 0) {
     vlog.error("Error getting listening sockets from systemd: %s",
@@ -130,13 +141,11 @@ static int createSystemdListeners(std::list<SocketListener*> *listeners)
       listeners->push_back(new TcpListener(SD_LISTEN_FDS_START + i));
 
   return count;
-}
 #else
-static int createSystemdListeners(std::list<SocketListener*> *)
-{
+  (void)listeners;
   return 0;
-}
 #endif
+}
 
 
 class FileTcpFilter : public TcpFilter
@@ -277,6 +286,10 @@ int main(int argc, char** argv)
   Configuration::removeParam("SendCutText");
   Configuration::removeParam("MaxCutText");
 
+  // Assume different defaults when socket activated
+  if (hasSystemdListeners())
+    rfbport.setParam(-1);
+
   for (int i = 1; i < argc; i++) {
     if (Configuration::setParam(argv[i]))
       continue;
@@ -325,40 +338,40 @@ int main(int argc, char** argv)
 
     VNCServerST server(desktopName, &desktop);
 
-    if (createSystemdListeners(&listeners)) {
+    if (createSystemdListeners(&listeners) > 0) {
       // When systemd is in charge of listeners, do not listen to anything else
       vlog.info("Listening on systemd sockets");
-    } else {
-      if (rfbunixpath.getValueStr()[0] != '\0') {
-        listeners.push_back(new network::UnixListener(rfbunixpath, rfbunixmode));
-        vlog.info("Listening on %s (mode %04o)", (const char*)rfbunixpath, (int)rfbunixmode);
-      }
+    }
 
-      if ((int)rfbport != -1) {
-        std::list<network::SocketListener*> tcp_listeners;
-        const char *addr = interface;
-
-        if (strcasecmp(addr, "all") == 0)
-          addr = 0;
-        if (localhostOnly)
-          createLocalTcpListeners(&tcp_listeners, (int)rfbport);
-        else
-          createTcpListeners(&tcp_listeners, addr, (int)rfbport);
-
-        if (!tcp_listeners.empty()) {
-          listeners.splice (listeners.end(), tcp_listeners);
-          vlog.info("Listening for VNC connections on %s interface(s), port %d",
-                    localhostOnly ? "local" : (const char*)interface,
-                    (int)rfbport);
-        }
+    if (rfbunixpath.getValueStr()[0] != '\0') {
+      listeners.push_back(new network::UnixListener(rfbunixpath, rfbunixmode));
+      vlog.info("Listening on %s (mode %04o)", (const char*)rfbunixpath, (int)rfbunixmode);
+    }
 
-        FileTcpFilter fileTcpFilter(hostsFile);
-        if (strlen(hostsFile) != 0)
-          for (std::list<SocketListener*>::iterator i = listeners.begin();
-               i != listeners.end();
-               i++)
-            (*i)->setFilter(&fileTcpFilter);
+    if ((int)rfbport != -1) {
+      std::list<network::SocketListener*> tcp_listeners;
+      const char *addr = interface;
+
+      if (strcasecmp(addr, "all") == 0)
+        addr = 0;
+      if (localhostOnly)
+        createLocalTcpListeners(&tcp_listeners, (int)rfbport);
+      else
+        createTcpListeners(&tcp_listeners, addr, (int)rfbport);
+
+      if (!tcp_listeners.empty()) {
+        listeners.splice (listeners.end(), tcp_listeners);
+        vlog.info("Listening for VNC connections on %s interface(s), port %d",
+                  localhostOnly ? "local" : (const char*)interface,
+                  (int)rfbport);
       }
+
+      FileTcpFilter fileTcpFilter(hostsFile);
+      if (strlen(hostsFile) != 0)
+        for (std::list<SocketListener*>::iterator i = listeners.begin();
+             i != listeners.end();
+             i++)
+          (*i)->setFilter(&fileTcpFilter);
     }
 
     if (listeners.empty()) {

unix/x0vncserver/x0vncserver.man

@@ -60,8 +60,8 @@ DISPLAY environment variable.
 .B \-rfbport \fIport\fP
 Specifies the TCP port on which x0vncserver listens for connections from
 viewers (the protocol used in VNC is called RFB - "remote framebuffer").
-The default port is 5900. Specify \fB-1\fP to disable listening on a TCP
-port. Ignored when activated by a systemd socket.
+Specify \fB-1\fP to disable listening on a TCP port. The default port is
+5900 when started directly, and -1 when activated by a systemd socket.
 .
 .TP
 .B \-UseIPv4
@@ -74,7 +74,8 @@ Use IPv6 for incoming and outgoing connections. Default is on.
 .TP
 .B \-rfbunixpath \fIpath\fP
 Specifies the path of a Unix domain socket on which x0vncserver listens for
-connections from viewers. Ignored when activated by a systemd socket.
+connections from viewers. Default is to not listen to any Unix domain
+socket.
 .
 .TP
 .B \-rfbunixmode \fImode\fP