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import avahi, dbus, dbus.glib, dbus.dbus_bindings, gobject
import Buddy
import Service
import random
import logging
from sugar import env
def _get_local_ip_address(ifname):
"""Call Linux specific bits to retrieve our own IP address."""
import socket
import sys
import fcntl
addr = None
SIOCGIFADDR = 0x8915
sockfd = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
try:
ifreq = (ifname + '\0'*32)[:32]
result = fcntl.ioctl(sockfd.fileno(), SIOCGIFADDR, ifreq)
addr = socket.inet_ntoa(result[20:24])
except IOError, exc:
print "Error getting IP address: %s" % exc
sockfd.close()
return addr
class ServiceAdv(object):
"""Wrapper class to track services from Avahi."""
def __init__(self, interface, protocol, name, stype, domain):
self._interface = interface
self._protocol = protocol
if type(name) != type(u""):
raise ValueError("service advertisement name must be unicode.")
self._name = name
if type(stype) != type(u""):
raise ValueError("service advertisement type must be unicode.")
self._stype = stype
if type(domain) != type(u""):
raise ValueError("service advertisement domain must be unicode.")
self._domain = domain
self._service = None
self._resolved = False
def interface(self):
return self._interface
def protocol(self):
return self._protocol
def name(self):
return self._name
def stype(self):
return self._stype
def domain(self):
return self._domain
def service(self):
return self._service
def set_service(self, service):
if not isinstance(service, Service.Service):
raise ValueError("must be a valid service.")
self._service = service
def resolved(self):
return self._resolved
def set_resolved(self, resolved):
self._resolved = resolved
_PRESENCE_SERVICE = "org.laptop.Presence"
_PRESENCE_DBUS_INTERFACE = "org.laptop.Presence"
_PRESENCE_OBJECT_PATH = "/org/laptop/Presence"
class PresenceServiceDBusHelper(dbus.service.Object):
def __init__(self, parent, bus_name):
self._parent = parent
self._bus_name = bus_name
dbus.service.Object.__init__(self, bus_name, _PRESENCE_OBJECT_PATH)
@dbus.service.signal(_PRESENCE_DBUS_INTERFACE,
signature="o")
def BuddyAppeared(self, object_path):
pass
@dbus.service.signal(_PRESENCE_DBUS_INTERFACE,
signature="o")
def BuddyDisappeared(self, object_path):
pass
@dbus.service.signal(_PRESENCE_DBUS_INTERFACE,
signature="o")
def ServiceAppeared(self, object_path):
pass
@dbus.service.signal(_PRESENCE_DBUS_INTERFACE,
signature="o")
def ServiceDisappeared(self, object_path):
pass
@dbus.service.signal(_PRESENCE_DBUS_INTERFACE,
signature="o")
def ActivityAppeared(self, object_path):
pass
@dbus.service.signal(_PRESENCE_DBUS_INTERFACE,
signature="o")
def ActivityDisappeared(self, object_path):
pass
class PresenceService(object):
def __init__(self):
# interface -> IP address: interfaces we've gotten events on so far
self._local_addrs = {}
self._next_object_id = 0
# Our owner object
self._owner = None
self._buddies = {} # nick -> Buddy
self._services = {} # (name, type) -> Service
self._activities = {} # activity id -> Activity
# Keep track of stuff we're already browsing with ZC
self._service_type_browsers = {}
self._service_browsers = {}
self._resolve_queue = [] # Track resolve requests
# Resolved service list
self._service_advs = []
# Service types we care about resolving
self._registered_service_types = []
# Set up the dbus service we provide
session_bus = dbus.SessionBus()
self._bus_name = dbus.service.BusName(_PRESENCE_SERVICE, bus=session_bus)
self._dbus_helper = PresenceServiceDBusHelper(self, self._bus_name)
# Connect to Avahi for mDNS stuff
self._system_bus = dbus.SystemBus()
self._mdns_service = dbus.Interface(self._system_bus.get_object(avahi.DBUS_NAME,
avahi.DBUS_PATH_SERVER), avahi.DBUS_INTERFACE_SERVER)
# Always browse .local
self._new_domain_cb(avahi.IF_UNSPEC, avahi.PROTO_UNSPEC, "local")
# Connect to Avahi and start looking for stuff
domain_browser = self._mdns_service.DomainBrowserNew(avahi.IF_UNSPEC, avahi.PROTO_UNSPEC,
"", avahi.DOMAIN_BROWSER_BROWSE, dbus.UInt32(0))
db = dbus.Interface(self._system_bus.get_object(avahi.DBUS_NAME, domain_browser), avahi.DBUS_INTERFACE_DOMAIN_BROWSER)
db.connect_to_signal('ItemNew', self._new_domain_cb_glue)
def _get_next_object_id(self):
"""Increment and return the object ID counter."""
self._next_object_id = self._next_object_id + 1
return self._next_object_id
def _find_service_adv(self, interface=None, protocol=None, name=None, stype=None, domain=None):
"""Search a list of service advertisements for ones matching certain criteria."""
adv_list = []
for adv in self._service_advs:
if interface and adv.interface() != interface:
continue
if protocol and adv.protocol() != protocol:
continue
if name and adv.name() != name:
continue
if stype and adv.stype() != stype:
continue
if domain and adv.domain() != domain:
continue
adv_list.append(adv)
return adv_list
def _handle_new_service_for_buddy(self, service):
"""Deal with a new discovered service object."""
# Once a service is resolved, we match it up to an existing buddy,
# or create a new Buddy if this is the first service known about the buddy
buddy_was_valid = False
name = service.get_name()
buddy = None
try:
buddy = self._buddies[name]
buddy_was_valid = buddy.is_valid()
service_added = buddy.add_service(service)
if service_added:
self._dbus_helper.ServiceAppeared(service.object_path())
except KeyError:
# Should this service mark the owner?
owner_nick = env.get_nick_name()
publisher_addr = service.get_publisher_address()
objid = self._get_next_object_id()
if name == owner_nick and publisher_addr in self._local_addrs.values():
buddy = Buddy.Owner(self._bus_name, objid, service)
self._owner = buddy
logging.debug("Owner is '%s'." % name)
else:
buddy = Buddy.Buddy(self._bus_name, objid, service)
self._buddies[name] = buddy
self._dbus_helper.ServiceAppeared(service.object_path())
if not buddy_was_valid and buddy.is_valid():
self._dbus_helper.BuddyAppeared(buddy.object_path())
return buddy
def _handle_new_activity_service(self, service):
# If the serivce is an activity service, merge it into our activities list
actid = service.get_activity_id()
if not actid:
return
activity = None
if not self._activities.has_key(actid):
objid = self._get_next_object_id()
activity = Activity.Activity(self._bus_name, objid, service)
self._activities[actid] = activity
self._dbus_helper.ActivityAppeared(activity.object_path())
else:
activity = self._activities[actid]
if activity:
activity.add_service(service)
def _handle_remove_activity_service(self, service):
actid = service.get_activity_id()
if not actid:
return
if not self._activities.has_key(actid):
return
activity = self._activities[actid]
activity.remove_service(service)
if len(activity.get_services()) == 0:
# Kill the activity
self._dbus_helper.ActivityDisappeared(activity.object_path())
del self._activities[actid]
def _resolve_service_reply_cb(self, interface, protocol, full_name, stype, domain, host, aprotocol, address, port, txt, flags):
"""When the service discovery finally gets here, we've got enough information about the
service to assign it to a buddy."""
logging.debug("resolved service '%s' type '%s' domain '%s' to %s:%s" % (full_name, stype, domain, address, port))
# If this service was previously unresolved, remove it from the
# unresolved list
adv_list = self._find_service_adv(interface=interface, protocol=protocol,
name=full_name, stype=stype, domain=domain)
if not adv_list:
return False
adv = adv_list[0]
adv.set_resolved(True)
if adv in self._resolve_queue:
self._resolve_queue.remove(adv)
# Update the service now that it's been resolved
objid = self._get_next_object_id()
service = Service.Service(self._bus_name, objid, name=full_name,
stype=stype, domain=domain, address=address, port=port,
properties=txt)
adv.set_service(service)
# Merge the service into our buddy and activity lists, if needed
buddy = self._handle_new_service_for_buddy(service)
if buddy and service.get_activity_id():
self._handle_new_activity_service(service)
return False
def _resolve_service_reply_cb_glue(self, interface, protocol, name, stype, domain, host, aprotocol, address, port, txt, flags):
gobject.idle_add(self._resolve_service_reply_cb, interface, protocol,
name, stype, domain, host, aprotocol, address, port, txt, flags)
def _resolve_service(self, adv):
"""Resolve and lookup a ZeroConf service to obtain its address and TXT records."""
# Ask avahi to resolve this particular service
logging.debug('resolving service %s %s' % (adv.name(), adv.stype()))
self._mdns_service.ResolveService(int(adv.interface()), int(adv.protocol()), adv.name(),
adv.stype(), adv.domain(), avahi.PROTO_UNSPEC, dbus.UInt32(0),
reply_handler=self._resolve_service_reply_cb_glue,
error_handler=self._resolve_service_error_handler)
return False
def _service_appeared_cb(self, interface, protocol, full_name, stype, domain, flags):
logging.debug("found service '%s' (%d) of type '%s' in domain '%s' on %i.%i." % (full_name, flags, stype, domain, interface, protocol))
# Add the service to our unresolved services list
adv_list = self._find_service_adv(interface=interface, protocol=protocol,
name=full_name, stype=stype, domain=domain)
adv = None
if not adv_list:
adv = ServiceAdv(interface=interface, protocol=protocol, name=full_name,
stype=stype, domain=domain)
self._service_advs.append(adv)
else:
adv = adv_list[0]
# Find out the IP address of this interface, if we haven't already
if interface not in self._local_addrs.keys():
ifname = self._mdns_service.GetNetworkInterfaceNameByIndex(interface)
if ifname:
addr = _get_local_ip_address(ifname)
if addr:
self._local_addrs[interface] = addr
# Decompose service name if we can
(actid, buddy_name) = Service._decompose_service_name(full_name)
# If we care about the service right now, resolve it
resolve = False
if actid is not None or stype in self._registered_service_types:
resolve = True
if resolve and not adv in self._resolve_queue:
self._resolve_queue.append(adv)
gobject.idle_add(self._resolve_service, adv)
else:
logging.debug("Do not resolve service '%s' of type '%s', we don't care about it." % (full_name, stype))
return False
def _service_appeared_cb_glue(self, interface, protocol, name, stype, domain, flags):
gobject.idle_add(self._service_appeared_cb, interface, protocol, name, stype, domain, flags)
def _service_disappeared_cb(self, interface, protocol, full_name, stype, domain, flags):
logging.debug("service '%s' of type '%s' in domain '%s' on %i.%i disappeared." % (full_name, stype, domain, interface, protocol))
# If it's an unresolved service, remove it from our unresolved list
adv_list = self._find_service_adv(interface=interface, protocol=protocol,
name=full_name, stype=stype, domain=domain)
if not adv_list:
return False
# Get the service object; if none, we have nothing left to do
adv = adv_list[0]
if adv in self._resolve_queue:
self._resolve_queue.remove(adv)
service = adv.service()
if not service:
return False
# Decompose service name if we can
(actid, buddy_name) = Service._decompose_service_name(full_name)
# Remove the service from the buddy
try:
buddy = self._buddies[buddy_name]
except KeyError:
pass
else:
buddy.remove_service(service)
self._dbus_helper.ServiceDisappeared(service.object_path())
self._handle_remove_activity_service(service)
if not buddy.is_valid():
self._dbus_helper.BuddyDisappeared(buddy.object_path())
del self._buddies[buddy_name]
return False
def _service_disappeared_cb_glue(self, interface, protocol, name, stype, domain, flags):
gobject.idle_add(self._service_disappeared_cb, interface, protocol, name, stype, domain, flags)
def _new_service_type_cb(self, interface, protocol, stype, domain, flags):
# Are we already browsing this domain for this type?
if self._service_browsers.has_key((interface, protocol, stype, domain)):
return
# Start browsing for all services of this type in this domain
s_browser = self._mdns_service.ServiceBrowserNew(interface, protocol, stype, domain, dbus.UInt32(0))
browser_obj = dbus.Interface(self._system_bus.get_object(avahi.DBUS_NAME, s_browser),
avahi.DBUS_INTERFACE_SERVICE_BROWSER)
logging.debug("now browsing for services of type '%s' in domain '%s' on %i.%i ..." % (stype, domain, interface, protocol))
browser_obj.connect_to_signal('ItemNew', self._service_appeared_cb_glue)
browser_obj.connect_to_signal('ItemRemove', self._service_disappeared_cb_glue)
self._service_browsers[(interface, protocol, stype, domain)] = browser_obj
return False
def _new_service_type_cb_glue(self, interface, protocol, stype, domain, flags):
gobject.idle_add(self._new_service_type_cb, interface, protocol, stype, domain, flags)
def _new_domain_cb(self, interface, protocol, domain, flags=0):
"""Callback from Avahi when a new domain has been found. Start
browsing the new domain."""
# Only use .local for now...
if domain != "local":
return
# Are we already browsing this domain?
if self._service_type_browsers.has_key((interface, protocol, domain)):
return
# Start browsing this domain for the services its members offer
try:
st_browser = self._mdns_service.ServiceTypeBrowserNew(interface, protocol, domain, dbus.UInt32(0))
browser_obj = dbus.Interface(self._system_bus.get_object(avahi.DBUS_NAME, st_browser),
avahi.DBUS_INTERFACE_SERVICE_TYPE_BROWSER)
except dbus.DBusException, exc:
logging.error("got exception %s while attempting to browse domain %s on %i.%i" % (domain, interface, protocol))
str_exc = str(exc)
if str_exc.find("The name org.freedesktop.Avahi was not provided by any .service files") >= 0:
raise Exception("Avahi does not appear to be running. '%s'" % str_exc)
else:
raise exc
logging.debug("now browsing domain '%s' on %i.%i ..." % (domain, interface, protocol))
browser_obj.connect_to_signal('ItemNew', self._new_service_type_cb_glue)
self._service_type_browsers[(interface, protocol, domain)] = browser_obj
return False
def _new_domain_cb_glue(self, interface, protocol, domain, flags=0):
gobject.idle_add(self._new_domain_cb, interface, protocol, domain, flags)
def main():
import gtk
ps = PresenceService()
gtk.main()
if __name__ == "__main__":
main()
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