| """ |
| OpenFlow Test Framework |
| |
| DataPlane and DataPlanePort classes |
| |
| Provide the interface to the control the set of ports being used |
| to stimulate the switch under test. |
| |
| See the class dataplaneport for more details. This class wraps |
| a set of those objects allowing general calls and parsing |
| configuration. |
| |
| @todo Add "filters" for matching packets. Actions supported |
| for filters should include a callback or a counter |
| """ |
| |
| import sys |
| import os |
| import socket |
| import time |
| import netutils |
| from threading import Thread |
| from threading import Lock |
| from threading import Condition |
| import select |
| import logging |
| from oft_assert import oft_assert |
| from ofutils import * |
| |
| have_pypcap = False |
| try: |
| import pcap |
| if hasattr(pcap, "pcap"): |
| # the incompatible pylibpcap library masquerades as pcap |
| have_pypcap = True |
| except: |
| pass |
| |
| ##@todo Find a better home for these identifiers (dataplane) |
| RCV_SIZE_DEFAULT = 4096 |
| ETH_P_ALL = 0x03 |
| RCV_TIMEOUT = 10000 |
| |
| def match_exp_pkt(exp_pkt, pkt): |
| """ |
| Compare the string value of pkt with the string value of exp_pkt, |
| and return True iff they are identical. If the length of exp_pkt is |
| less than the minimum Ethernet frame size (60 bytes), then padding |
| bytes in pkt are ignored. |
| """ |
| e = str(exp_pkt) |
| p = str(pkt) |
| if len(e) < 60: |
| p = p[:len(e)] |
| return e == p |
| |
| |
| class DataPlanePort(Thread): |
| """ |
| Class defining a port monitoring object. |
| |
| Control a dataplane port connected to the switch under test. |
| Creates a promiscuous socket on a physical interface. |
| Queues the packets received on that interface with time stamps. |
| Inherits from Thread class as meant to run in background. Also |
| supports polling. |
| |
| Currently assumes a controlling 'parent' which maintains a |
| common Lock object and a total packet-pending count. May want |
| to decouple that some day. |
| """ |
| |
| 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 |
| logname = "dp-" + interface_name |
| self.logger = logging.getLogger(logname) |
| try: |
| self.socket = self.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 |
| self.killed = False |
| |
| # Used to wake up the event loop in kill() |
| self.waker = EventDescriptor() |
| |
| def interface_open(self, interface_name): |
| """ |
| Open a socket in a promiscuous mode for a data connection. |
| @param interface_name port name as a string such as 'eth1' |
| @retval s socket |
| """ |
| s = socket.socket(socket.AF_PACKET, socket.SOCK_RAW, |
| socket.htons(ETH_P_ALL)) |
| s.bind((interface_name, 0)) |
| netutils.set_promisc(s, interface_name) |
| s.settimeout(RCV_TIMEOUT) |
| return s |
| |
| def run(self): |
| """ |
| Activity function for class |
| """ |
| self.socs = [self.socket, self.waker] |
| error_warned = False # Have we warned about error? |
| while not self.killed: |
| try: |
| sel_in, sel_out, sel_err = \ |
| select.select(self.socs, [], [], 1) |
| except: |
| print sys.exc_info() |
| self.logger.error("Select error, exiting") |
| break |
| |
| if (sel_in is None) or (len(sel_in) == 0): |
| continue |
| |
| if self.waker in sel_in: |
| self.waker.wait() |
| continue |
| |
| try: |
| rcvmsg = self.socket.recv(RCV_SIZE_DEFAULT) |
| except socket.error: |
| if not error_warned: |
| self.logger.info("Socket error on recv") |
| error_warned = True |
| continue |
| |
| if len(rcvmsg) == 0: |
| self.logger.info("Zero len pkt rcvd") |
| self.kill() |
| break |
| |
| rcvtime = time.time() |
| self.logger.debug("Pkt len " + str(len(rcvmsg)) + |
| " 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((rcvmsg, rcvtime)) |
| self.packets_total += 1 |
| self.parent.pkt_sync.notify_all() |
| |
| self.logger.info("Thread exit") |
| |
| def kill(self): |
| """ |
| Terminate the running thread |
| """ |
| self.logger.debug("Port monitor kill") |
| self.killed = True |
| self.waker.notify() |
| 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 |
| """ |
| return self.socket.send(packet) |
| |
| 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) |
| |
| |
| def port_down(self,port_number,config): |
| |
| """ |
| Grabs a port from the dataplane ports and brings it down by |
| shutting the corresponding interface |
| @port_number The port number which has brought to be down |
| @interface_name The interface corresponding to the port that needs to |
| be brought down |
| |
| """ |
| interface_name = config["port_map"].get(port_number) |
| cmd = 'ifdown '+ interface_name |
| os.system(cmd) |
| |
| def port_up(self,port_number,config): |
| |
| """ |
| Grabs a port from the dataplane ports and brings it up by |
| starting up the corresponding interface |
| @port_number The port number which has to brought up |
| @interface_name The interface corresponding to the port that has to |
| be brought up |
| |
| """ |
| interface_name = config["port_map"].get(port_number) |
| cmd = 'ifup '+ interface_name |
| os.system(cmd) |
| |
| |
| class DataPlanePortPcap(DataPlanePort): |
| """ |
| Alternate port implementation using libpcap. This is required for recent |
| versions of Linux (such as Linux 3.2 included in Ubuntu 12.04) which |
| offload the VLAN tag, so it isn't in the data returned from a read on a raw |
| socket. libpcap understands how to read the VLAN tag from the kernel. |
| """ |
| |
| def __init__(self, interface_name, port_number, parent, max_pkts=1024): |
| DataPlanePort.__init__(self, interface_name, port_number, parent, max_pkts) |
| |
| def interface_open(self, interface_name): |
| """ |
| Open a PCAP interface. |
| """ |
| self.pcap = pcap.pcap(interface_name) |
| self.pcap.setnonblock() |
| return self.pcap.fileno() |
| |
| def run(self): |
| """ |
| Activity function for class |
| """ |
| while not self.killed: |
| try: |
| sel_in, sel_out, sel_err = select.select([self.socket, self.waker], [], [], 1) |
| except: |
| print sys.exc_info() |
| self.logger.error("Select error, exiting") |
| break |
| |
| if (sel_in is None) or (len(sel_in) == 0): |
| continue |
| |
| if self.waker in sel_in: |
| self.waker.wait() |
| continue |
| |
| # Enqueue packet |
| with self.parent.pkt_sync: |
| for (timestamp, rcvmsg) in self.pcap.readpkts(): |
| self.logger.debug("Pkt len " + str(len(rcvmsg)) + |
| " in at " + str(timestamp) + " on port " + |
| str(self.port_number)) |
| |
| 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((rcvmsg, timestamp)) |
| self.packets_total += 1 |
| self.parent.pkt_sync.notify_all() |
| |
| self.logger.info("Thread exit") |
| |
| def kill(self): |
| """ |
| Terminate the running thread |
| """ |
| self.logger.debug("Port monitor kill") |
| self.killed = True |
| self.waker.notify() |
| # pcap object is closed on GC. |
| |
| 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 |
| """ |
| return self.pcap.inject(packet, len(packet)) |
| |
| class DataPlane: |
| """ |
| Class defining access primitives to the data plane |
| Controls a list of DataPlanePort objects |
| """ |
| def __init__(self, config=None): |
| self.port_list = {} |
| # pkt_sync serves double duty as a regular top level lock and |
| # as a condition variable |
| self.pkt_sync = Condition() |
| |
| # These are used to signal async pkt arrival for polling |
| self.want_pkt = False |
| self.exp_pkt = None |
| self.want_pkt_port = None # What port required (or None) |
| self.got_pkt_port = None # On what port received? |
| self.packets_pending = 0 # Total pkts in all port queues |
| self.logger = logging.getLogger("dataplane") |
| |
| if config is None: |
| self.config = {} |
| else: |
| self.config = config; |
| |
| ############################################################ |
| # |
| # We use the DataPlanePort class defined here by |
| # default for all port traffic: |
| # |
| if have_pypcap: |
| self.dppclass = DataPlanePortPcap |
| else: |
| self.logger.warning("Missing pypcap, VLAN tests may fail. See README for installation instructions.") |
| self.dppclass = DataPlanePort |
| |
| ############################################################ |
| # |
| # The platform/config can provide a custom DataPlanePort class |
| # here if you have a custom implementation with different |
| # behavior. |
| # |
| # Set config.dataplane.portclass = MyDataPlanePortClass |
| # where MyDataPlanePortClass has the same interface as the class |
| # DataPlanePort defined here. |
| # |
| if "dataplane" in self.config: |
| if "portclass" in self.config["dataplane"]: |
| self.dppclass = self.config["dataplane"]["portclass"] |
| |
| if self.dppclass == None: |
| raise Exception("Problem determining DataPlanePort class.") |
| |
| |
| def port_add(self, interface_name, port_number): |
| """ |
| Add a port to the dataplane |
| TBD: Max packets for queue? |
| @param interface_name The name of the physical interface like eth1 |
| @param port_number The port number used to refer to the port |
| """ |
| |
| self.port_list[port_number] = self.dppclass(interface_name, |
| port_number, self); |
| |
| self.port_list[port_number].start() |
| |
| |
| |
| def send(self, port_number, packet): |
| """ |
| Send a packet to the given port |
| @param port_number The port to send the data to |
| @param packet Raw packet data to send to port |
| """ |
| self.logger.debug("Sending %d bytes to port %d" % |
| (len(packet), port_number)) |
| bytes = self.port_list[port_number].send(packet) |
| if bytes != len(packet): |
| self.logger.error("Unhandled send error, length mismatch %d != %d" % |
| (bytes, len(packet))) |
| return bytes |
| |
| |
| |
| |
| def flood(self, packet): |
| """ |
| Send a packet to all ports |
| @param packet Raw packet data to send to port |
| """ |
| for port_number in self.port_list.keys(): |
| bytes = self.port_list[port_number].send(packet) |
| if bytes != len(packet): |
| self.logger.error("Unhandled send error" + |
| ", port %d, length mismatch %d != %d" % |
| (port_number, bytes, len(packet))) |
| |
| # Returns the port with the oldest packet, or None if no packets are queued. |
| def oldest_port(self): |
| min_port = None |
| min_time = float('inf') |
| for port in self.port_list.values(): |
| ptime = port.timestamp_head() |
| if ptime and ptime < min_time: |
| min_time = ptime |
| min_port = port |
| return min_port |
| |
| # Dequeues and yields packets in the order they were received. |
| # Yields (port, packet, received time). |
| # If port_number is not specified yields packets from all ports. |
| def packets(self, port_number=None): |
| while True: |
| if port_number == None: |
| port = self.oldest_port() |
| else: |
| port = self.port_list[port_number] |
| |
| if port == None or len(port.packets) == 0: |
| self.logger.debug("Out of packets for port %s" % str(port_number)) |
| # Out of packets |
| break |
| |
| pkt, time = port.packets.pop(0) |
| yield (port, pkt, time) |
| |
| def poll(self, port_number=None, timeout=-1, exp_pkt=None): |
| """ |
| Poll one or all dataplane ports for a packet |
| |
| If port_number is given, get the oldest packet from that port. |
| Otherwise, find the port with the oldest packet and return |
| that packet. |
| |
| If exp_pkt is true, discard all packets until that one is found |
| |
| @param port_number If set, get packet from this port |
| @param timeout If positive and no packet is available, block |
| until a packet is received or for this many seconds |
| @param exp_pkt If not None, look for this packet and ignore any |
| others received. Note that if port_number is None, all packets |
| from all ports will be discarded until the exp_pkt is found |
| @return The triple port_number, packet, pkt_time where packet |
| is received from port_number at time pkt_time. If a timeout |
| occurs, return None, None, None |
| """ |
| |
| if exp_pkt and not port_number: |
| self.logger.warn("Dataplane poll with exp_pkt but no port number") |
| |
| # Retrieve the packet. Returns (port number, packet, time). |
| def grab(): |
| self.logger.debug("Grabbing packet") |
| for (port, pkt, time) in self.packets(port_number): |
| self.logger.debug("Checking packet from port %d" % port.port_number) |
| if not exp_pkt or match_exp_pkt(exp_pkt, pkt): |
| return (port, pkt, time) |
| self.logger.debug("Did not find packet") |
| return None |
| |
| with self.pkt_sync: |
| ret = timed_wait(self.pkt_sync, grab, timeout=timeout) |
| |
| if ret != None: |
| (port, pkt, time) = ret |
| return (port.port_number, pkt, time) |
| else: |
| self.logger.debug("Poll time out, no packet from " + str(port_number)) |
| return (None, None, None) |
| |
| def kill(self, join_threads=True): |
| """ |
| Close all sockets for dataplane |
| @param join_threads If True call join on each thread |
| """ |
| for port_number in self.port_list.keys(): |
| self.port_list[port_number].kill() |
| |
| if join_threads: |
| for port_number in self.port_list.keys(): |
| self.logger.debug("Joining " + str(port_number)) |
| self.port_list[port_number].join() |
| |
| self.port_list = None |
| |
| self.logger.info("DataPlane shutdown") |
| |
| def show(self, prefix=''): |
| print prefix + "Dataplane Controller" |
| print prefix + "Packets pending" + str(self.packets_pending) |
| for pnum, port in self.port_list.items(): |
| print prefix + "OpenFlow Port Number " + str(pnum) |
| port.show(prefix + ' ') |
| |
| |
| def port_down(self,port_number): |
| """Brings the specified port down""" |
| self.port_list[port_number].port_down(port_number,self.config) |
| |
| |
| def port_up(self,port_number): |
| """Brings the specified port up""" |
| self.port_list[port_number].port_up(port_number,self.config) |