+# Copyright (c) 2012 Nicira Networks
+#
+# 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.
+
+import copy
+import errno
+import os
+import types
+
+import ovs.daemon
+import ovs.dirs
+import ovs.jsonrpc
+import ovs.stream
+import ovs.util
+import ovs.version
+import ovs.vlog
+
+Message = ovs.jsonrpc.Message
+vlog = ovs.vlog.Vlog("unixctl")
+commands = {}
+strtypes = types.StringTypes
+
+
+class _UnixctlCommand(object):
+ def __init__(self, usage, min_args, max_args, callback, aux):
+ self.usage = usage
+ self.min_args = min_args
+ self.max_args = max_args
+ self.callback = callback
+ self.aux = aux
+
+
+def _unixctl_help(conn, unused_argv, unused_aux):
+ assert isinstance(conn, UnixctlConnection)
+ reply = "The available commands are:\n"
+ command_names = sorted(commands.keys())
+ for name in command_names:
+ reply += " "
+ usage = commands[name].usage
+ if usage:
+ reply += "%-23s %s" % (name, usage)
+ else:
+ reply += name
+ reply += "\n"
+ conn.reply(reply)
+
+
+def _unixctl_version(conn, unused_argv, unused_aux):
+ assert isinstance(conn, UnixctlConnection)
+ version = "%s (Open vSwitch) %s %s" % (ovs.util.PROGRAM_NAME,
+ ovs.version.VERSION,
+ ovs.version.BUILDNR)
+ conn.reply(version)
+
+
+def command_register(name, usage, min_args, max_args, callback, aux):
+ """ Registers a command with the given 'name' to be exposed by the
+ UnixctlServer. 'usage' describes the arguments to the command; it is used
+ only for presentation to the user in "help" output.
+
+ 'callback' is called when the command is received. It is passed a
+ UnixctlConnection object, the list of arguments as unicode strings, and
+ 'aux'. Normally 'callback' should reply by calling
+ UnixctlConnection.reply() or UnixctlConnection.reply_error() before it
+ returns, but if the command cannot be handled immediately, then it can
+ defer the reply until later. A given connection can only process a single
+ request at a time, so a reply must be made eventually to avoid blocking
+ that connection."""
+
+ assert isinstance(name, strtypes)
+ assert isinstance(usage, strtypes)
+ assert isinstance(min_args, int)
+ assert isinstance(max_args, int)
+ assert isinstance(callback, types.FunctionType)
+
+ if name not in commands:
+ commands[name] = _UnixctlCommand(usage, min_args, max_args, callback,
+ aux)
+
+
+def socket_name_from_target(target):
+ assert isinstance(target, strtypes)
+
+ if target.startswith("/"):
+ return 0, target
+
+ pidfile_name = "%s/%s.pid" % (ovs.dirs.RUNDIR, target)
+ pid = ovs.daemon.read_pidfile(pidfile_name)
+ if pid < 0:
+ return -pid, "cannot read pidfile \"%s\"" % pidfile_name
+
+ return 0, "%s/%s.%d.ctl" % (ovs.dirs.RUNDIR, target, pid)
+
+
+class UnixctlConnection(object):
+ def __init__(self, rpc):
+ assert isinstance(rpc, ovs.jsonrpc.Connection)
+ self._rpc = rpc
+ self._request_id = None
+
+ def run(self):
+ self._rpc.run()
+ error = self._rpc.get_status()
+ if error or self._rpc.get_backlog():
+ return error
+
+ for _ in range(10):
+ if error or self._request_id:
+ break
+
+ error, msg = self._rpc.recv()
+ if msg:
+ if msg.type == Message.T_REQUEST:
+ self._process_command(msg)
+ else:
+ # XXX: rate-limit
+ vlog.warn("%s: received unexpected %s message"
+ % (self._rpc.name,
+ Message.type_to_string(msg.type)))
+ error = errno.EINVAL
+
+ if not error:
+ error = self._rpc.get_status()
+
+ return error
+
+ def reply(self, body):
+ self._reply_impl(True, body)
+
+ def reply_error(self, body):
+ self._reply_impl(False, body)
+
+ # Called only by unixctl classes.
+ def _close(self):
+ self._rpc.close()
+ self._request_id = None
+
+ def _wait(self, poller):
+ self._rpc.wait(poller)
+ if not self._rpc.get_backlog():
+ self._rpc.recv_wait(poller)
+
+ def _reply_impl(self, success, body):
+ assert isinstance(success, bool)
+ assert body is None or isinstance(body, strtypes)
+
+ assert self._request_id is not None
+
+ if body is None:
+ body = ""
+
+ if body and not body.endswith("\n"):
+ body += "\n"
+
+ if success:
+ reply = Message.create_reply(body, self._request_id)
+ else:
+ reply = Message.create_error(body, self._request_id)
+
+ self._rpc.send(reply)
+ self._request_id = None
+
+ def _process_command(self, request):
+ assert isinstance(request, ovs.jsonrpc.Message)
+ assert request.type == ovs.jsonrpc.Message.T_REQUEST
+
+ self._request_id = request.id
+
+ error = None
+ params = request.params
+ method = request.method
+ command = commands.get(method)
+ if command is None:
+ error = '"%s" is not a valid command' % method
+ elif len(params) < command.min_args:
+ error = '"%s" command requires at least %d arguments' \
+ % (method, command.min_args)
+ elif len(params) > command.max_args:
+ error = '"%s" command takes at most %d arguments' \
+ % (method, command.max_args)
+ else:
+ for param in params:
+ if not isinstance(param, strtypes):
+ error = '"%s" command has non-string argument' % method
+ break
+
+ if error is None:
+ unicode_params = [unicode(p) for p in params]
+ command.callback(self, unicode_params, command.aux)
+
+ if error:
+ self.reply_error(error)
+
+
+class UnixctlServer(object):
+ def __init__(self, listener):
+ assert isinstance(listener, ovs.stream.PassiveStream)
+ self._listener = listener
+ self._conns = []
+
+ def run(self):
+ for _ in range(10):
+ error, stream = self._listener.accept()
+ if not error:
+ rpc = ovs.jsonrpc.Connection(stream)
+ self._conns.append(UnixctlConnection(rpc))
+ elif error == errno.EAGAIN:
+ break
+ else:
+ # XXX: rate-limit
+ vlog.warn("%s: accept failed: %s" % (self._listener.name,
+ os.strerror(error)))
+
+ for conn in copy.copy(self._conns):
+ error = conn.run()
+ if error and error != errno.EAGAIN:
+ conn._close()
+ self._conns.remove(conn)
+
+ def wait(self, poller):
+ self._listener.wait(poller)
+ for conn in self._conns:
+ conn._wait(poller)
+
+ def close(self):
+ for conn in self._conns:
+ conn._close()
+ self._conns = None
+
+ self._listener.close()
+ self._listener = None
+
+ @staticmethod
+ def create(path):
+ assert path is None or isinstance(path, strtypes)
+
+ if path is not None:
+ path = "punix:%s" % ovs.util.abs_file_name(ovs.dirs.RUNDIR, path)
+ else:
+ path = "punix:%s/%s.%d.ctl" % (ovs.dirs.RUNDIR,
+ ovs.util.PROGRAM_NAME, os.getpid())
+
+ error, listener = ovs.stream.PassiveStream.open(path)
+ if error:
+ ovs.util.ovs_error(error, "could not initialize control socket %s"
+ % path)
+ return error, None
+
+ command_register("help", "", 0, 0, _unixctl_help, None)
+ command_register("version", "", 0, 0, _unixctl_version, None)
+
+ return 0, UnixctlServer(listener)
+
+
+class UnixctlClient(object):
+ def __init__(self, conn):
+ assert isinstance(conn, ovs.jsonrpc.Connection)
+ self._conn = conn
+
+ def transact(self, command, argv):
+ assert isinstance(command, strtypes)
+ assert isinstance(argv, list)
+ for arg in argv:
+ assert isinstance(arg, strtypes)
+
+ request = Message.create_request(command, argv)
+ error, reply = self._conn.transact_block(request)
+
+ if error:
+ vlog.warn("error communicating with %s: %s"
+ % (self._conn.name, os.strerror(error)))
+ return error, None, None
+
+ if reply.error is not None:
+ return 0, str(reply.error), None
+ else:
+ assert reply.result is not None
+ return 0, None, str(reply.result)
+
+ def close(self):
+ self._conn.close()
+ self.conn = None
+
+ @staticmethod
+ def create(path):
+ assert isinstance(path, str)
+
+ unix = "unix:%s" % ovs.util.abs_file_name(ovs.dirs.RUNDIR, path)
+ error, stream = ovs.stream.Stream.open_block(
+ ovs.stream.Stream.open(unix))
+
+ if error:
+ vlog.warn("failed to connect to %s" % path)
+ return error, None
+
+ return 0, UnixctlClient(ovs.jsonrpc.Connection(stream))