VOL-1097 : Ofagent integration for voltha 2.0
- Created a common location for python based components
- Adjusted the ofagent component to interact with voltha 2.0
- Added streaming rpc methods for rcv/send of packets to voltha api
- Adjusted voltha.proto
Change-Id: I47fb7b80878ead060b4b42bd16cb4f8aa384fdb6
diff --git a/python/ofagent/loxi/connection.py b/python/ofagent/loxi/connection.py
new file mode 100644
index 0000000..fc61161
--- /dev/null
+++ b/python/ofagent/loxi/connection.py
@@ -0,0 +1,263 @@
+# Copyright 2017-present Open Networking Foundation
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# Copyright 2015, Big Switch Networks, Inc.
+
+"""
+OpenFlow connection class
+
+This class creates a thread which continually parses OpenFlow messages off the
+supplied socket and places them in a queue. The class has methods for reading messages
+from the RX queue, sending messages, and higher level operations like request-response
+and multipart transactions.
+"""
+
+import loxi
+import loxi.of14
+import logging
+import time
+import socket
+import errno
+import os
+import select
+from threading import Condition, Lock, Thread
+
+DEFAULT_TIMEOUT = 1
+
+class TransactionError(Exception):
+ def __str__(self):
+ return self.args[0]
+
+ @property
+ def msg(self):
+ return self.args[1]
+
+class ConnectionClosed(Exception):
+ pass
+
+class Connection(Thread):
+ def __init__(self, sock):
+ Thread.__init__(self)
+ self.sock = sock
+ self.logger = logging.getLogger("connection")
+ self.rx = []
+ self.rx_cv = Condition()
+ self.tx_lock = Lock()
+ self.next_xid = 1
+ self.wakeup_rd, self.wakeup_wr = os.pipe()
+ self.finished = False
+ self.read_buffer = None
+
+ def start(self):
+ while not self.finished:
+ try:
+ rd, wr, err = select.select([self.sock, self.wakeup_rd], [], [])
+ except select.error:
+ print 'SELECT ERROR!!!'
+ if self.sock in rd:
+ try:
+ self.process_read()
+ except ConnectionClosed:
+ self.logger.info("Connection to controller was dropped")
+ self.finished = True
+ if self.wakeup_rd in rd:
+ os.read(self.wakeup_rd, 1)
+ self.logger.debug("Exited event loop")
+
+ def process_read(self):
+ recvd = self.sock.recv(4096)
+ if (len(recvd)) == 0:
+ # this indicates that the other end hang up
+ raise ConnectionClosed()
+
+ self.logger.debug("Received %d bytes", len(recvd))
+
+ buf = self.read_buffer
+ if buf:
+ buf += recvd
+ else:
+ buf = recvd
+
+ offset = 0
+ while offset < len(buf):
+ if offset + 8 > len(buf):
+ # Not enough data for the OpenFlow header
+ break
+
+ # Parse the header to get type
+ hdr_version, hdr_type, hdr_msglen, hdr_xid = loxi.of14.message.parse_header(buf[offset:])
+
+ # Use loxi to resolve ofp of matching version
+ ofp = loxi.protocol(hdr_version)
+
+ # Extract the raw message bytes
+ if (offset + hdr_msglen) > len(buf):
+ # Not enough data for the body
+ break
+ rawmsg = buf[offset : offset + hdr_msglen]
+ offset += hdr_msglen
+
+ msg = ofp.message.parse_message(rawmsg)
+ if not msg:
+ self.logger.warn("Could not parse message")
+ continue
+
+ self.logger.debug("Received message %s.%s xid %d length %d",
+ type(msg).__module__, type(msg).__name__, hdr_xid, hdr_msglen)
+
+ with self.rx_cv:
+ self.rx.append(msg)
+ self.rx_cv.notify_all()
+
+ if offset == len(buf):
+ self.read_buffer = None
+ else:
+ self.read_buffer = buf[offset:]
+ self.logger.debug("%d bytes remaining", len(self.read_buffer))
+
+ def recv(self, predicate, timeout=DEFAULT_TIMEOUT):
+ """
+ Remove and return the first message in the RX queue for
+ which 'predicate' returns true
+ """
+ assert self.is_alive()
+
+ deadline = time.time() + timeout
+ while True:
+ with self.rx_cv:
+ for i, msg in enumerate(self.rx):
+ if predicate(msg):
+ return self.rx.pop(i)
+
+ now = time.time()
+ if now > deadline:
+ return None
+ else:
+ self.rx_cv.wait(deadline - now)
+
+ def recv_any(self, timeout=DEFAULT_TIMEOUT):
+ """
+ Return the first message in the RX queue
+ """
+ return self.recv(lambda msg: True, timeout)
+
+ def recv_xid(self, xid, timeout=DEFAULT_TIMEOUT):
+ """
+ Return the first message in the RX queue with XID 'xid'
+ """
+ return self.recv(lambda msg: msg.xid == xid, timeout)
+
+ def recv_class(self, klass, timeout=DEFAULT_TIMEOUT):
+ """
+ Return the first message in the RX queue which is an instance of 'klass'
+ """
+ return self.recv(lambda msg: isinstance(msg, klass), timeout)
+
+ def send_raw(self, buf):
+ """
+ Send raw bytes on the socket
+ """
+ assert self.is_alive()
+ self.logger.debug("Sending raw message length %d", len(buf))
+ with self.tx_lock:
+ if self.sock.sendall(buf) is not None:
+ raise RuntimeError("failed to send message to switch")
+
+ def send(self, msg):
+ """
+ Send a message
+ """
+ assert self.is_alive()
+
+ if msg.xid is None:
+ msg.xid = self._gen_xid()
+ buf = msg.pack()
+ self.logger.debug("Sending message %s.%s xid %d length %d",
+ type(msg).__module__, type(msg).__name__, msg.xid, len(buf))
+ with self.tx_lock:
+ if self.sock.sendall(buf) is not None:
+ raise RuntimeError("failed to send message to switch")
+
+ def transact(self, msg, timeout=DEFAULT_TIMEOUT):
+ """
+ Send a message and return the reply
+ """
+ self.send(msg)
+ reply = self.recv_xid(msg.xid, timeout)
+ if reply is None:
+ raise TransactionError("no reply for %s" % type(msg).__name__, None)
+ elif isinstance(reply, loxi.protocol(reply.version).message.error_msg):
+ raise TransactionError("received %s in response to %s" % (type(reply).__name__, type(msg).__name__), reply)
+ return reply
+
+ def transact_multipart_generator(self, msg, timeout=DEFAULT_TIMEOUT):
+ """
+ Send a multipart request and yield each entry from the replies
+ """
+ self.send(msg)
+ finished = False
+ while not finished:
+ reply = self.recv_xid(msg.xid, timeout)
+ if reply is None:
+ raise TransactionError("no reply for %s" % type(msg).__name__, None)
+ elif not isinstance(reply, loxi.protocol(reply.version).message.stats_reply):
+ raise TransactionError("received %s in response to %s" % (type(reply).__name__, type(msg).__name__), reply)
+ for entry in reply.entries:
+ yield entry
+ finished = reply.flags & loxi.protocol(reply.version).OFPSF_REPLY_MORE == 0
+
+ def transact_multipart(self, msg, timeout=DEFAULT_TIMEOUT):
+ """
+ Send a multipart request and return all entries from the replies
+ """
+ entries = []
+ for entry in self.transact_multipart_generator(msg, timeout):
+ entries.append(entry)
+ return entries
+
+ def stop(self):
+ """
+ Signal the thread to exit and wait for it
+ """
+ assert not self.finished
+ self.logger.debug("Stopping connection")
+ self.finished = True
+ os.write(self.wakeup_wr, "x")
+ self.join()
+ self.sock.close()
+ os.close(self.wakeup_rd)
+ os.close(self.wakeup_wr)
+ self.logger.debug("Stopped connection")
+
+ def _gen_xid(self):
+ xid = self.next_xid
+ self.next_xid += 1
+ return xid
+
+def connect(ip, port=6653, daemon=True, ofp=loxi.of14):
+ """
+ Actively connect to a switch
+ """
+ soc = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+ soc.connect((ip, port))
+ soc.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, True)
+ cxn = Connection(soc)
+ cxn.daemon = daemon
+ cxn.logger.debug("Connected to %s:%d", ip, port)
+ cxn.start()
+
+ cxn.send(ofp.message.hello())
+ if not cxn.recv(lambda msg: msg.type == ofp.OFPT_HELLO):
+ raise Exception("Did not receive HELLO")
+
+ return cxn