+# Copyright (c) 2011, 2012 Nicira, Inc.
+#
+# 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 types
+
+import ovs.util
+
+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):
+ 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 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)
+
+command_register("help", "", 0, 0, _unixctl_help, None)