frodo-wii/Src/network-broker/main.py
2009-03-08 09:00:13 +00:00

277 lines
8.4 KiB
Python

import socket, struct, syslog
import SocketServer
FRODO_NETWORK_MAGIC = 0x1976
CONNECT_TO_BROKER = 99 # Hello, broker
LIST_PEERS = 98 # List of peers
CONNECT_TO_PEER = 97 # A peer wants to connect
SELECT_PEER = 93 # The client selects who to connect to
DISCONNECT = 96 # Disconnect from a peer
PING = 95 # Are you alive?
ACK = 94 # Yep
STOP = 55 # No more packets
def log(pri, msg, echo):
syslog.syslog(pri, msg)
# if echo:
print msg
def log_error(msg, echo = False):
log(syslog.LOG_ERR, msg, echo)
def log_warn(msg, echo = False):
log(syslog.LOG_WARNING, msg, echo)
def log_info(msg, echo = False):
log(syslog.LOG_INFO, msg, echo)
class Packet:
def __init__(self):
"""Create a new packet"""
self.magic = FRODO_NETWORK_MAGIC
self.type = 0
self.size = 8
def demarshal_from_data(self, data):
"""Create a new packet from raw data. Data should always be in network
byte order"""
self.magic = struct.unpack(">H", data[0:2])[0]
self.type = struct.unpack(">H", data[2:4])[0]
self.size = struct.unpack(">L", data[4:8])[0]
def get_magic(self):
return self.magic
def get_type(self):
return self.type
def get_size(self):
return self.size
def marshal(self):
return struct.pack(">HHL", self.magic, self.type, self.size)
class StopPacket(Packet):
def __init__(self):
Packet.__init__(self)
self.type = STOP
class SelectPeerPacket(Packet):
def __init__(self):
Packet.__init__(self)
self.type = SELECT_PEER
self.server_id = 0
def demarshal_from_data(self, data):
"""Create a new packet from raw data."""
Packet.demarshal_from_data(self, data)
self.server_id = struct.unpack("<L", data[8:12])[0]
def get_id(self):
return self.server_id
class ConnectToBrokerPacket(Packet):
def __init__(self):
self.key = 0
self._is_master = 0
self.private_port = 0
self.public_port = 0
self.private_ip = ""
self.public_ip = ""
self.type = CONNECT_TO_BROKER
self.name = ""
self.serverid = 0
def demarshal_from_data(self, data):
Packet.demarshal_from_data(self, data)
self.key = struct.unpack(">H", data[44:46])[0]
self._is_master = struct.unpack(">H", data[46:48])[0]
self.name = struct.unpack(">32s", data[48:48+32])[0]
def get_key(self):
return self.key
def get_name(self):
return self.name
def is_master(self):
return self._is_master
class ListPeersPacket(Packet):
def __init__(self):
Packet.__init__(self)
self.n_peers = 0
self.peers = []
self.type = LIST_PEERS
self.size = self.size + 24
def add_peer(self, peer):
self.peers.append(peer)
self.n_peers = self.n_peers + 1
self.size = self.size + 76
def marshal(self):
out = struct.pack(">L16sHxx", self.n_peers, "", 0)
for peer in self.peers:
out = out + struct.pack(">HH16s16sHH32sL",
0, peer.public_port, "",
peer.public_ip, peer.key,
peer.is_master, peer.name,
peer.id)
return Packet.marshal(self) + out
class Peer:
def __init__(self, addr, srv, id):
self.srv = srv
self.addr = addr
self.public_ip, self.public_port = self.addr_to_ip_and_port(addr)
# These will be set by the CONNECT_TO_BROKER packet below
self.key = 0
self.name = ""
self.is_master = 0
self.id = id
def addr_to_ip_and_port(self, addr):
ip = struct.unpack("@L", socket.inet_pton(socket.AF_INET, addr[0]))[0]
port = addr[1]
return "%08x" % (ip), port
def handle_packet(self, pkt):
if pkt.type == CONNECT_TO_BROKER:
self.key = pkt.get_key()
self.name = pkt.get_name()
self.is_master = pkt.is_master()
# Send list of peers if this is not a master
if not self.is_master:
lp = ListPeersPacket()
for peer in self.srv.peers.itervalues():
if peer != self and peer.is_master:
lp.add_peer(peer)
# And send the packet to this peer
log_info("Sending list of peers (%d) to %s:%d" % (lp.n_peers,
self.addr[0], self.addr[1]) )
self.send_packet(lp.marshal())
if pkt.type == SELECT_PEER:
peer = self.srv.get_peer_by_id( pkt.get_id() )
# Tell the peer that we have connected
lp = ListPeersPacket()
lp.add_peer(self)
log_info("Sending list of peers for peer selected to %s:%d" % (
self.addr[0], self.addr[1]))
peer.send_packet( lp.marshal() )
# These two are no longer needed
self.srv.remove_peer(peer)
self.srv.remove_peer(self)
def send_packet(self, data):
self.srv.socket.sendto(data + StopPacket().marshal(),
0, self.addr)
def __str__(self):
return '%s:%d "%s" %d %d' % (self.public_ip, self.public_port,
self.name, self.key, self.is_master)
class BrokerPacketHandler(SocketServer.DatagramRequestHandler):
def get_packet_from_data(self, data):
magic = struct.unpack(">H", data[0:2])[0]
type = struct.unpack(">H", data[2:4])[0]
if magic != FRODO_NETWORK_MAGIC:
raise Exception("Packet magic does not match: %4x vs %4x\n" % (magic,
FRODO_NETWORK_MAGIC) )
try:
out = packet_class_by_type[type]()
out.demarshal_from_data(data)
return out
except KeyError, e:
raise Exception("Unknown packet type %d" % (type))
def handle(self):
srv = self.server
data = self.rfile.read()
try:
pkt = self.get_packet_from_data(data)
except Exception, e:
log_error("Broken packet: %s" % e)
return
log_info("Received packet %d from %s:%d" % (pkt.get_type(), self.client_address[0],
self.client_address[1]))
peer = srv.get_peer(self.client_address)
try:
peer.handle_packet(pkt)
except Exception, e:
# Sends crap, let's remove it
log_error("Handling packet failed, removing peer: %s" % e)
srv.remove_peer(peer)
class Broker(SocketServer.UDPServer):
def __init__(self, host, req_handler):
SocketServer.UDPServer.__init__(self, host, req_handler)
# Instead of setsockopt( ... REUSEADDR ... )
self.allow_reuse_address = True
self.peers = {}
self.peers_by_id = {}
self.id = 0
def send_data(self, dst, data):
self.socket.sendto(data, dst)
def get_peer(self, key):
"Return the peer for a certain key, or a new one if it doesn't exist"
try:
peer = self.peers[key]
except KeyError, e:
peer = Peer(key, self, self.id)
self.peers[key] = peer
self.peers_by_id[self.id] = peer
self.id = self.id + 1
return peer
def get_peer_by_id(self, id):
return self.peers_by_id[id]
def get_peer_by_name_key(self, name, key):
for k,v in self.peers.iteritems():
if name == v.get_name() and key == v.get_key():
return v
return None
def remove_peer(self, peer):
try:
del self.peers[ peer.addr ]
del self.peers_by_id[ peer.id ]
except:
log_error("Could not remove %s, something is wrong" % (str(peer.addr)))
# Some of the Frodo network packets. There are more packets, but these
# are not interesting to the broker (and shouldn't be sent there either!)
packet_class_by_type = {
CONNECT_TO_BROKER : ConnectToBrokerPacket,
SELECT_PEER : SelectPeerPacket,
}
if __name__ == "__main__":
syslog.openlog("frodo")
log_info("Starting Frodo network broker", True)
s = Broker( ("", 46214), BrokerPacketHandler)
s.serve_forever()