add ovs-dummy platform
Original author: Ben Pfaff <blp@nicira.com>
diff --git a/platforms/ovs-dummy.py b/platforms/ovs-dummy.py
new file mode 100644
index 0000000..bc6f862
--- /dev/null
+++ b/platforms/ovs-dummy.py
@@ -0,0 +1,213 @@
+"""
+Dummy platform
+
+This platform uses Open vSwitch dummy interfaces.
+"""
+
+import logging
+import os
+import select
+import socket
+import struct
+import sys
+import time
+from threading import Thread
+from threading import Lock
+
+RCV_TIMEOUT = 10000
+RUN_DIR = os.environ.get("OVS_RUNDIR", "/var/run/openvswitch")
+
+class DataPlanePortOVSDummy(Thread):
+ """
+ Class defining a port monitoring object that uses Unix domain
+ sockets for ports, intended for connecting to Open vSwitch "dummy"
+ netdevs.
+ """
+
+ def __init__(self, interface_name, port_number, parent, max_pkts=1024):
+ """
+ Set up a port monitor object
+ @param interface_name The name of the physical interface like eth1
+ @param port_number The port number associated with this port
+ @param parent The controlling dataplane object; for pkt wait CV
+ @param max_pkts Maximum number of pkts to keep in queue
+ """
+ Thread.__init__(self)
+ self.interface_name = interface_name
+ self.max_pkts = max_pkts
+ self.packets_total = 0
+ self.packets = []
+ self.packets_discarded = 0
+ self.port_number = port_number
+ self.txq = []
+ self.txq_lock = Lock()
+ logname = "dp-" + interface_name
+ self.logger = logging.getLogger(logname)
+ try:
+ self.socket = DataPlanePortOVSDummy.interface_open(interface_name)
+ except:
+ self.logger.info("Could not open socket")
+ raise
+ self.logger.info("Opened port monitor (class %s)", type(self).__name__)
+ self.parent = parent
+
+ @staticmethod
+ def interface_open(interface_name):
+ """
+ Open a Unix domain socket interface.
+ @param interface_name port name as a string such as 'eth1'
+ @retval s socket
+ """
+ s = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
+ s.settimeout(RCV_TIMEOUT)
+ s.setblocking(0)
+ s.connect("%s/%s" % (RUN_DIR, interface_name))
+ return s
+
+ def run(self):
+ """
+ Activity function for class
+ """
+ self.running = True
+ rxbuf = ""
+ while self.running:
+ try:
+ self.txq_lock.acquire()
+ if self.txq:
+ wlist = [self.socket]
+ else:
+ wlist = []
+ self.txq_lock.release()
+
+ rout, wout, eout = select.select([self.socket], wlist, [], 1)
+ except:
+ print sys.exc_info()
+ self.logger.error("Select error, exiting")
+ break
+
+ if not self.running:
+ break
+
+ if wout:
+ self.txq_lock.acquire()
+ if self.txq:
+ retval = self.socket.send(self.txq[0])
+ if retval > 0:
+ self.txq[0] = self.txq[0][retval:]
+ if len(self.txq[0]) == 0:
+ self.txq = self.txq[1:]
+ self.txq_lock.release()
+
+ if rout:
+ if len(rxbuf) < 2:
+ n = 2 - len(rxbuf)
+ else:
+ frame_len = struct.unpack('>h', rxbuf[:2])[0]
+ n = (2 + frame_len) - len(rxbuf)
+
+ data = self.socket.recv(n)
+ rxbuf += data
+ if len(data) == n and len(rxbuf) > 2:
+ rcvtime = time.clock()
+ self.logger.debug("Pkt len " + str(len(rxbuf)) +
+ " in at " + str(rcvtime) + " on port " +
+ str(self.port_number))
+
+ # Enqueue packet
+ with self.parent.pkt_sync:
+ if len(self.packets) >= self.max_pkts:
+ # Queue full, throw away oldest
+ self.packets.pop(0)
+ self.packets_discarded += 1
+ self.logger.debug("Discarding oldest packet to make room")
+ self.packets.append((rxbuf[2:], rcvtime))
+ self.packets_total += 1
+ self.parent.pkt_sync.notify_all()
+
+ rxbuf = ''
+
+ self.logger.info("Thread exit")
+
+ def kill(self):
+ """
+ Terminate the running thread
+ """
+ self.logger.debug("Port monitor kill")
+ self.running = False
+ try:
+ self.socket.close()
+ except:
+ self.logger.info("Ignoring dataplane soc shutdown error")
+
+ def timestamp_head(self):
+ """
+ Return the timestamp of the head of queue or None if empty
+ """
+ rv = None
+ try:
+ rv = self.packets[0][1]
+ except:
+ rv = None
+ return rv
+
+ def flush(self):
+ """
+ Clear the packet queue
+ """
+ with self.parent.pkt_sync:
+ self.packets_discarded += len(self.packets)
+ self.packets = []
+
+ def send(self, packet):
+ """
+ Send a packet to the dataplane port
+ @param packet The packet data to send to the port
+ @retval The number of bytes sent
+ """
+
+ self.txq_lock.acquire()
+ if len(self.txq) < self.max_pkts:
+ self.txq.append(struct.pack('>h', len(packet)) + packet)
+ retval = len(packet)
+ else:
+ retval = 0
+ self.txq_lock.release()
+
+ return retval
+
+ def register(self, handler):
+ """
+ Register a callback function to receive packets from this
+ port. The callback will be passed the packet, the
+ interface name and the port number (if set) on which the
+ packet was received.
+
+ To be implemented
+ """
+ pass
+
+ def show(self, prefix=''):
+ print prefix + "Name: " + self.interface_name
+ print prefix + "Pkts pending: " + str(len(self.packets))
+ print prefix + "Pkts total: " + str(self.packets_total)
+ print prefix + "socket: " + str(self.socket)
+
+# Update this dictionary to suit your environment.
+dummy_port_map = {
+ 1 : "p1",
+ 2 : "p2",
+ 3 : "p3",
+ 4 : "p4"
+}
+
+def platform_config_update(config):
+ """
+ Update configuration for the dummy platform
+
+ @param config The configuration dictionary to use/update
+ """
+ global dummy_port_map
+ config["port_map"] = dummy_port_map.copy()
+ config["caps_table_idx"] = 0
+ config["dataplane"] = {"portclass": DataPlanePortOVSDummy}
+ config["allow_user"] = True