#1332: add a "list-mdns" subcommand for showing mdns sessions

git-svn-id: https://xpra.org/svn/Xpra/trunk@14011 3bb7dfac-3a0b-4e04-842a-767bc560f471

src/man/xpra.1

@@ -246,6 +246,8 @@ xpra \- viewer for remote, persistent X applications
 .HP
 \fBxpra\fP \fBlist\fP [\fB\-\-socket\-dir\fP=\fIDIR\fP]
 .HP
+\fBxpra\fP \fBlist-mdns\fP
+.HP
 \fBxpra\fP \fBupgrade\fP \fI:[DISPLAY]\fP [...any options accepted by
 \fBxpra start\fP...]
 .PD
@@ -312,6 +314,9 @@ appear until you attach with \fBxpra attach\fP.
 \fBxpra list\fP
 Show a list of xpra servers you have running on the current host.
 .TP
+\fBxpra\fP \fBlist-mdns\fP
+Show a list of xpra servers found via mDNS. (local network)
+.TP
 \fBxpra showconfig\fP
 Shows the configuration that would be used with other sub-commands,
 taking into account the command line arguments.

src/xpra/net/mdns/avahi_listener.py

@@ -0,0 +1,117 @@
+#!/usr/bin/env python
+
+# This file is part of Xpra.
+# Copyright (C) 2009-2016 Antoine Martin <[email protected]>
+# Xpra is released under the terms of the GNU GPL v2, or, at your option, any
+# later version. See the file COPYING for details.
+
+import avahi
+import dbus
+
+from xpra.net.mdns import XPRA_MDNS_TYPE
+from xpra.dbus.common import init_system_bus
+from xpra.dbus.helper import dbus_to_native
+
+from xpra.log import Logger
+log = Logger("network", "mdns")
+
+
+class AvahiListener:
+
+	def __init__(self, service_type, mdns_found=None, mdns_add=None, mdns_remove=None):
+		log("AvahiListener%s", (service_type, mdns_found, mdns_add, mdns_remove))
+		try:
+			self.bus = init_system_bus()
+			assert self.bus
+		except Exception as e:
+			log.warn("failed to connect to the system dbus: %s", e)
+			log.warn(" either start a dbus session or disable mdns support")
+			return
+		self.sdref = None
+		self.readers = []
+		self.resolvers = []
+		self.service_type = service_type
+		self.mdns_found = mdns_found
+		self.mdns_add = mdns_add
+		self.mdns_remove = mdns_remove
+		self.server = None
+
+	def resolve_error(self, *args):
+		log.error("AvahiListener.resolve_error%s", args)
+
+	def service_resolved(self, interface, protocol, name, stype, domain, host, x, address, port, text_array, v):
+		log("AvahiListener.service_resolved%s", (interface, protocol, name, stype, domain, host, x, address, port, "..", v))
+		if self.mdns_add:
+			#parse text data:
+			text = {}
+			try:
+				for text_line in text_array:
+					line = ""
+					for b in text_line:
+						line += chr(b.real)
+					parts = line.split("=", 1)
+					if len(parts)==2:
+						text[parts[0]] = parts[1]
+				log(" text=%s", text)
+			except Exception:
+				log.error("failed to parse text record", exc_info=True)
+			nargs = (dbus_to_native(x) for x in (interface, name, domain, host, address, port, text))
+			self.mdns_add(*nargs)
+
+	def service_found(self, interface, protocol, name, stype, domain, flags):
+		log("service_found%s", (interface, protocol, name, stype, domain, flags))
+		if flags & avahi.LOOKUP_RESULT_LOCAL:
+			# local service, skip
+			pass
+		if self.mdns_found:
+			self.mdns_found(dbus_to_native(interface), dbus_to_native(name))
+		self.server.ResolveService(interface, protocol, name, stype,
+				domain, avahi.PROTO_UNSPEC, dbus.UInt32(0),
+				reply_handler=self.service_resolved, error_handler=self.resolve_error)
+
+	def service_removed(self, interface, protocol, name, stype, domain, flags):
+		log("service_removed%s", (interface, protocol, name, stype, domain, flags))
+		if self.mdns_remove:
+			nargs = (dbus_to_native(x) for x in (interface, protocol, name, stype, domain, flags))
+			self.mdns_remove(*nargs)
+
+
+	def start(self):
+		self.server = dbus.Interface(self.bus.get_object(avahi.DBUS_NAME, '/'), 'org.freedesktop.Avahi.Server')
+		log("AvahiListener.start() server=%s", self.server)
+
+		self.sbrowser = dbus.Interface(self.bus.get_object(avahi.DBUS_NAME,
+								self.server.ServiceBrowserNew(avahi.IF_UNSPEC,
+								avahi.PROTO_UNSPEC, XPRA_MDNS_TYPE, 'local', dbus.UInt32(0))),
+								avahi.DBUS_INTERFACE_SERVICE_BROWSER)
+		log("AvahiListener.start() service browser=%s", self.sbrowser)
+		self.sbrowser.connect_to_signal("ItemNew", self.service_found)
+		self.sbrowser.connect_to_signal("ItemRemove", self.service_removed)
+
+	def stop(self):
+		#FIXME: how do we tell dbus we are no longer interested?
+		pass
+
+
+def main():
+	def mdns_found(*args):
+		print("mdns_found: %s" % (args, ))
+	def mdns_add(*args):
+		print("mdns_add: %s" % (args, ))
+	def mdns_remove(*args):
+		print("mdns_remove: %s" % (args, ))
+
+	from xpra.dbus.common import loop_init
+	loop_init()
+	listener = AvahiListener(XPRA_MDNS_TYPE, mdns_found, mdns_add, mdns_remove)
+	try:
+		from xpra.gtk_common.gobject_compat import import_glib
+		glib = import_glib()
+		glib.idle_add(listener.start)
+		glib.MainLoop().run()
+	finally:
+		listener.stop()
+
+
+if __name__ == "__main__":
+	main()

src/xpra/scripts/main.py

@@ -82,6 +82,11 @@ def nox():
         from xpra.x11.bindings.wait_for_x_server import wait_for_x_server    #@UnresolvedImport @UnusedImport
     except:
         supports_server = False
+try:
+    from xpra.net import mdns
+    supports_mdns = bool(mdns)
+except:
+    supports_mdns = False
 
 
 #this parse doesn't exit when it encounters an error,
@@ -236,6 +241,8 @@ def do_parse_cmdline(cmdline, defaults):
                         "\t%prog version [DISPLAY]\n"
                         "\t%prog showconfig\n"
                       ]
+    if supports_mdns:
+        command_options.append("\t%prog list-mdns\n")
     server_modes = []
     if supports_server:
         server_modes.append("start")
@@ -1031,7 +1038,7 @@ def show_sound_codec_help(is_server, speaker_codecs, microphone_codecs):
 
 def configure_logging(options, mode):
     to = sys.stderr
-    if mode in ("showconfig", "info", "control", "list", "attach", "stop", "version", "print", "opengl", "test-connect"):
+    if mode in ("showconfig", "info", "control", "list", "list-mdns", "attach", "stop", "version", "print", "opengl", "test-connect"):
         to = sys.stdout
     #a bit naughty here, but it's easier to let xpra.log initialize
     #the logging system every time, and just undo things here..
@@ -1170,6 +1177,8 @@ def run_mode(script_file, error_cb, options, args, mode, defaults):
             return run_stopexit(mode, error_cb, options, args)
         elif mode == "list" and (supports_server or supports_shadow):
             return run_list(error_cb, options, args)
+        elif mode == "list-mdns" and supports_mdns:
+            return run_list_mdns(error_cb, options, args)
         elif mode in ("_proxy", "_proxy_start", "_proxy_start_desktop", "_shadow_start") and (supports_server or supports_shadow):
             nox()
             return run_proxy(error_cb, options, script_file, args, mode, defaults)
@@ -2439,6 +2448,78 @@ def may_cleanup_socket(state, display, sockpath, clean_states=[DotXpra.DEAD]):
             sys.stdout.write(" (cleaned up)")
     sys.stdout.write("\n")
 
+def run_list_mdns(error_cb, opts, extra_args):
+    no_gtk()
+    if len(extra_args)<=1:
+        try:
+            MDNS_WAIT = int(extra_args[0])
+        except:
+            MDNS_WAIT = 5
+    else:
+        error_cb("too many arguments for mode")
+    assert supports_mdns
+    from xpra.net.mdns import XPRA_MDNS_TYPE
+    try:
+        from xpra.net.mdns.avahi_listener import AvahiListener
+    except ImportError:
+        error_cb("sorry, 'list-mdns' is not supported on this platform yet")
+    from xpra.net.net_util import if_indextoname
+    from xpra.dbus.common import loop_init
+    from xpra.gtk_common.gobject_compat import import_glib
+    glib = import_glib()
+    loop_init()
+    try:
+        import collections
+        found = collections.OrderedDict()
+    except:
+        found = {}
+    shown = set()
+    def show_new_found():
+        new_found = [x for x in found.keys() if x not in shown]
+        for uq in new_found:
+            recs = found[uq]
+            for i, rec in enumerate(recs):
+                iface, _, _, host, address, port, text = rec
+                display = text.get("display")
+                mode = text.get("mode", "")
+                username = text.get("username", "")
+                session = text.get("session")
+                if i==0:
+                    print("* user '%s' on '%s'" % (username, host))
+                    if session:
+                        print(" session '%s'" % session)
+                print(" + %s endpoint on host %s, port %i, interface %s" % (mode, address, port, iface))
+                dstr = ""
+                if display.startswith(":"):
+                    dstr = display[1:]
+                uri = "%s/%s@%s:%s/%s" % (mode, username, address, port, dstr)
+                print("   \"%s\"" % uri)
+            shown.add(uq)
+    def mdns_add(interface, name, domain, host, address, port, text):
+        text = text or {}
+        iface = interface
+        if if_indextoname:
+            iface = if_indextoname(interface)
+        username = text.get("username", "")
+        uq = text.get("uuid", len(found)), username, host
+        found.setdefault(uq, []).append((iface, name, domain, host, address, port, text))
+        glib.timeout_add(1000, show_new_found)
+    listener = AvahiListener(XPRA_MDNS_TYPE, mdns_add=mdns_add)
+    print("Looking for xpra services via mdns")
+    try:
+        glib.idle_add(listener.start)
+        loop = glib.MainLoop()
+        glib.timeout_add(MDNS_WAIT*1000, loop.quit)
+        loop.run()
+    finally:
+        listener.stop()
+    if not found:
+        print("no services found")
+    else:
+        from xpra.util import engs
+        print("%i service%s found" % (len(found), engs(found)))
+
+
 def run_list(error_cb, opts, extra_args):
     no_gtk()
     if extra_args: