Add zeroconf/mdns support

libs/ardour/ardour/zeroconf.h

@@ -0,0 +1,58 @@
+/*
+ * Copyright (C) 2022 Robin Gareus <robin@gareus.org>
+ *
+ * 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 2 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, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <cstdint>
+#include <string>
+
+#ifdef __APPLE__
+#include <dns_sd.h>
+#include <glibmm/iochannel.h>
+#include <glibmm/main.h>
+#endif
+
+#include "ardour/libardour_visibility.h"
+#include "ardour/system_exec.h"
+
+namespace ARDOUR {
+
+class LIBARDOUR_API ZeroConf
+{
+public:
+	ZeroConf (std::string const& type = "_osc._udp", uint16_t port = 3819, std::string const& host = "");
+	~ZeroConf ();
+
+private:
+	bool start ();
+	void stop ();
+
+	std::string _type;
+	uint16_t    _port;
+	std::string _host;
+
+#ifdef __APPLE__
+	static gboolean event (GIOChannel*, GIOCondition, gpointer);
+
+	DNSServiceRef _ref;
+	guint         _source_id;
+	GIOChannel*   _gio_channel;
+#else
+	SystemExec* _avahi;
+#endif
+};
+
+}; // namespace ARDOUR

libs/ardour/wscript

@@ -282,7 +282,8 @@ libardour_sources = [
         'vca_manager.cc',
         'video_tools_paths.cc',
         'vumeterdsp.cc',
-        'worker.cc'
+        'worker.cc',
+        'zeroconf.cc'
 ]
 
 def options(opt):

libs/ardour/zeroconf.cc

@@ -0,0 +1,166 @@
+/*
+ * Copyright (C) 2022 Robin Gareus <robin@gareus.org>
+ *
+ * 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 2 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, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "pbd/compose.h"
+#include "pbd/error.h"
+#include "pbd/file_utils.h"
+
+#include "ardour/filesystem_paths.h"
+#include "ardour/zeroconf.h"
+
+#include "pbd/i18n.h"
+
+using namespace ARDOUR;
+
+ZeroConf::ZeroConf (std::string const& type, uint16_t port, std::string const& host)
+	: _type (type)
+	, _port (port)
+	, _host (host)
+#ifdef __APPLE__
+	, _source_id (0)
+	, _gio_channel (NULL)
+#else
+	, _avahi (NULL)
+#endif
+{
+	start ();
+}
+
+ZeroConf::~ZeroConf ()
+{
+	stop ();
+}
+
+#ifdef __APPLE__
+
+void
+ZeroConf::stop ()
+{
+	if (_gio_channel) {
+		g_source_remove (_source_id);
+		g_io_channel_unref (_gio_channel);
+	}
+	DNSServiceRefDeallocate (_ref);
+}
+
+static void
+dns_callback (DNSServiceRef       sdref,
+              DNSServiceFlags     flags,
+              DNSServiceErrorType errorCode,
+              const char*         name,
+              const char*         regtype,
+              const char* domain, void* context)
+{
+	if (errorCode == kDNSServiceErr_NoError) {
+		PBD::info << string_compose (_("ZeroConf registered: %1 %2 %3"), name, regtype, domain) << endmsg;
+	} else {
+		PBD::info << _("ZeroConf registration failed") << endmsg;
+	}
+}
+
+gboolean
+ZeroConf::event (GIOChannel*  source,
+                 GIOCondition condition,
+                 gpointer     data)
+{
+	ZeroConf* self = reinterpret_cast<ZeroConf*> (data);
+	// assert (_fd == g_io_channel_unix_get_fd (source));
+
+	if (condition & ~G_IO_IN) {
+		/* remove on error */
+		return false;
+	} else {
+		if (DNSServiceProcessResult (self->_ref) != kDNSServiceErr_NoError) {
+			/* ZeroConf Error in data callback */
+			return false;
+		}
+		return true;
+	}
+}
+
+bool
+ZeroConf::start ()
+{
+	if (kDNSServiceErr_NoError != DNSServiceRegister (&_ref, /*flags*/ 0, /*interfaceIndex*/ 0, /*name*/ NULL, _type.c_str (),
+	                                                  /*domain*/ NULL, _host.empty () ? NULL : _host.c_str (), g_htons (_port),
+	                                                  /*txtlen*/ 0, /*TXT*/ NULL, dns_callback, this)) {
+		return false;
+	}
+
+	int fd       = DNSServiceRefSockFD (_ref);
+	_gio_channel = g_io_channel_unix_new (fd);
+	_source_id   = g_io_add_watch (_gio_channel, (GIOCondition) (G_IO_IN | G_IO_ERR | G_IO_HUP), ZeroConf::event, this);
+	return true;
+}
+
+#elif defined PLATFORM_WINDOWS
+
+/* in theory dns_sd API also works on Windows 10+
+ * windns.h and dnsapi.dll
+ */
+
+bool
+ZeroConf::start ()
+{
+	return false;
+}
+
+bool
+ZeroConf::stop ()
+{
+}
+
+#else
+
+bool
+ZeroConf::start ()
+{
+	std::string avahi_exec;
+
+	PBD::Searchpath sp (ARDOUR::ardour_dll_directory ());
+	if (!PBD::find_file (sp, "ardour-avahi.sh", avahi_exec)) {
+		PBD::warning << "ardour-avahi.sh was not found." << endmsg;
+		return false;
+	}
+
+	char** argp;
+	char   tmp[128];
+	argp    = (char**)calloc (5, sizeof (char*));
+	argp[0] = strdup (avahi_exec.c_str ());
+	snprintf (tmp, sizeof (tmp), "%d", _port);
+	argp[1] = strdup (tmp);
+	argp[2] = strdup (_type.c_str ());
+	snprintf (tmp, sizeof (tmp), "%d", getpid ());
+	argp[3] = strdup (tmp);
+	argp[4] = 0;
+
+	_avahi = new ARDOUR::SystemExec (avahi_exec, argp);
+	if (_avahi->start (SystemExec::ShareWithParent)) {
+		return false;
+	}
+	return false;
+}
+
+void
+ZeroConf::stop ()
+{
+	ARDOUR::SystemExec* tmp = _avahi;
+	_avahi = 0;
+	delete tmp;
+}
+#endif

tools/avahi.sh

@@ -0,0 +1,24 @@
+#!/bin/sh
+
+set -e
+
+test -n "`which avahi-publish`"
+test -n "`which tail`"
+
+PORT=$1
+TYPE=$2
+test -n "$PORT"
+test -n "$TYPE"
+
+if test -n "$3"; then
+	PARENT_PID=$3
+else
+	PARENT_PID=$$
+fi
+
+avahi-publish -s Ardour-$PARENT_PID "$TYPE" "$PORT" &
+CHILD_PID=$!
+
+trap "kill -- $CHILD_PID" EXIT
+
+tail --pid=$PARENT_PID -f 2>/dev/null

tools/linux_packaging/build

@@ -506,6 +506,9 @@ EOF
 	chmod +x $APPLIB/ardour-util.sh
 fi
 
+cp $BUILD_ROOT/avahi.sh $APPLIB/ardour-avahi.sh
+chmod +x $APPLIB/ardour-avahi.sh
+
 OURLIBDIR=$BUILD_ROOT/libs
 OURLIBS=$OURLIBDIR/ctrl-interface/midi_surface:$OURLIBDIR/ctrl-interface/control_protocol:$OURLIBDIR/ardour:$OURLIBDIR/midi++2:$OURLIBDIR/pbd:$OURLIBDIR/gtkmm2ext:$OURLIBDIR/glibmm2:$OURLIBDIR/canvas:$OURLIBDIR/widgets:$OURLIBDIR/waveview:$OURLIBDIR/evoral:$OURLIBDIR/evoral/src/libsmf:$OURLIBDIR/audiographer:$OURLIBDIR/temporal:$OURLIBDIR/libltc:$OURLIBDIR/qm-dsp:$OURLIBDIR/ardouralsautil:$OURLIBDIR/ptformat:$BUILD_ROOT/gtk2_ardour
 

wscript

@@ -10,6 +10,7 @@ import platform as PLATFORM
 from waflib.Tools import winres
 from waflib.Build import Context
 from waflib.Build import BuildContext
+import waflib.Utils as Utils
 
 # Fixup OSX 10.5/10.6 builds
 # prefer gcc, g++ 4.x over ancient clang-1.5
@@ -1619,6 +1620,12 @@ def build(bld):
         bld.recurse('tools/sanity_check')
         bld.recurse('tools/gccabicheck')
 
+        obj              = bld(features = 'subst')
+        obj.source       = 'tools/avahi.sh'
+        obj.target       = 'libs/ardour-avahi.sh'
+        obj.chmod        = Utils.O755
+        obj.install_path = bld.env['LIBDIR']
+
     bld.recurse('libs/clearlooks-newer')
 
     for i in children: