#!/usr/bin/env python
"""
coresendmsg: utility for generating CORE messages
"""
import optparse
import os
import socket
import sys
from core.api.tlv import coreapi
from core.emulator.enumerations import (
CORE_API_PORT,
MessageFlags,
MessageTypes,
SessionTlvs,
)
def print_available_tlvs(t, tlv_class):
"""
Print a TLV list.
"""
print(f"TLVs available for {t} message:")
for tlv in sorted([tlv for tlv in tlv_class.tlv_type_map], key=lambda x: x.name):
print(f"{tlv.value}:{tlv.name}")
def print_examples(name):
"""
Print example usage of this script.
"""
examples = [
("link n1number=2 n2number=3 delay=15000",
"set a 15ms delay on the link between n2 and n3"),
("link n1number=2 n2number=3 guiattr=\"color=blue\"",
"change the color of the link between n2 and n3"),
("node number=3 xpos=125 ypos=525",
"move node number 3 to x,y=(125,525)"),
("node number=4 icon=/usr/local/share/core/icons/normal/router_red.gif",
"change node number 4\"s icon to red"),
("node flags=add number=5 type=0 name=\"n5\" xpos=500 ypos=500",
"add a new router node n5"),
("link flags=add n1number=4 n2number=5 if1ip4=\"10.0.3.2\" " \
"if1ip4mask=24 if2ip4=\"10.0.3.1\" if2ip4mask=24",
"link node n5 with n4 using the given interface addresses"),
("exec flags=str,txt node=1 num=1000 cmd=\"uname -a\" -l",
"run a command on node 1 and wait for the result"),
("exec node=2 num=1001 cmd=\"killall ospfd\"",
"run a command on node 2 and ignore the result"),
("file flags=add node=1 name=\"/var/log/test.log\" data=\"Hello World.\"",
"write a test.log file on node 1 with the given contents"),
("file flags=add node=2 name=\"test.log\" " \
"srcname=\"./test.log\"",
"move a test.log file from host to node 2"),
]
print(f"Example {name} invocations:")
for cmd, descr in examples:
print(f" {name} {cmd}\n\t\t{descr}")
def receive_message(sock):
"""
Retrieve a message from a socket and return the CoreMessage object or
None upon disconnect. Socket data beyond the first message is dropped.
"""
try:
# large receive buffer used for UDP sockets, instead of just receiving
# the 4-byte header
data = sock.recv(4096)
msghdr = data[:coreapi.CoreMessage.header_len]
except KeyboardInterrupt:
print("CTRL+C pressed")
sys.exit(1)
if len(msghdr) == 0:
return None
msgdata = None
msgtype, msgflags, msglen = coreapi.CoreMessage.unpack_header(msghdr)
if msglen:
msgdata = data[coreapi.CoreMessage.header_len:]
try:
msgcls = coreapi.CLASS_MAP[msgtype]
except KeyError:
msg = coreapi.CoreMessage(msgflags, msghdr, msgdata)
msg.message_type = msgtype
print(f"unimplemented CORE message type: {msg.type_str()}")
return msg
if len(data) > msglen + coreapi.CoreMessage.header_len:
data_size = len(data) - (msglen + coreapi.CoreMessage.header_len)
print(f"received a message of type {msgtype}, dropping {data_size} bytes of extra data")
return msgcls(msgflags, msghdr, msgdata)
def connect_to_session(sock, requested):
"""
Use Session Messages to retrieve the current list of sessions and
connect to the first one.
"""
# request the session list
tlvdata = coreapi.CoreSessionTlv.pack(SessionTlvs.NUMBER.value, "")
flags = MessageFlags.STRING.value
smsg = coreapi.CoreSessionMessage.pack(flags, tlvdata)
sock.sendall(smsg)
print("waiting for session list...")
smsgreply = receive_message(sock)
if smsgreply is None:
print("disconnected")
return False
sessstr = smsgreply.get_tlv(SessionTlvs.NUMBER.value)
if sessstr is None:
print("missing session numbers")
return False
# join the first session (that is not our own connection)
tmp, localport = sock.getsockname()
sessions = sessstr.split("|")
sessions.remove(str(localport))
if len(sessions) == 0:
print("no sessions to join")
return False
if not requested:
session = sessions[0]
elif requested in sessions:
session = requested
else:
print("requested session not found!")
return False
print(f"joining session: {session}")
tlvdata = coreapi.CoreSessionTlv.pack(SessionTlvs.NUMBER.value, session)
flags = MessageFlags.ADD.value
smsg = coreapi.CoreSessionMessage.pack(flags, tlvdata)
sock.sendall(smsg)
return True
def receive_response(sock, opt):
"""
Receive and print a CORE message from the given socket.
"""
print("waiting for response...")
msg = receive_message(sock)
if msg is None:
print(f"disconnected from {opt.address}:{opt.port}")
sys.exit(0)
print(f"received message: {msg}")
def main():
"""
Parse command-line arguments to build and send a CORE message.
"""
types = [message_type.name for message_type in MessageTypes]
flags = [flag.name for flag in MessageFlags]
usagestr = "usage: %prog [-h|-H] [options] [message-type] [flags=flags] "
usagestr += "[message-TLVs]\n\n"
usagestr += f"Supported message types:\n {types}\n"
usagestr += f"Supported message flags (flags=f1,f2,...):\n {flags}"
parser = optparse.OptionParser(usage=usagestr)
default_address = "localhost"
default_session = None
default_tcp = False
parser.set_defaults(
port=CORE_API_PORT,
address=default_address,
session=default_session,
listen=False,
examples=False,
tlvs=False,
tcp=default_tcp
)
parser.add_option("-H", dest="examples", action="store_true",
help="show example usage help message and exit")
parser.add_option("-p", "--port", dest="port", type=int,
help=f"TCP port to connect to, default: {CORE_API_PORT}")
parser.add_option("-a", "--address", dest="address", type=str,
help=f"Address to connect to, default: {default_address}")
parser.add_option("-s", "--session", dest="session", type=str,
help=f"Session to join, default: {default_session}")
parser.add_option("-l", "--listen", dest="listen", action="store_true",
help="Listen for a response message and print it.")
parser.add_option("-t", "--list-tlvs", dest="tlvs", action="store_true",
help="List TLVs for the specified message type.")
parser.add_option("--tcp", dest="tcp", action="store_true",
help=f"Use TCP instead of UDP and connect to a session default: {default_tcp}")
def usage(msg=None, err=0):
sys.stdout.write("\n")
if msg:
sys.stdout.write(msg + "\n\n")
parser.print_help()
sys.exit(err)
# parse command line opt
opt, args = parser.parse_args()
if opt.examples:
print_examples(os.path.basename(sys.argv[0]))
sys.exit(0)
if len(args) == 0:
usage("Please specify a message type to send.")
# given a message type t, determine the message and TLV classes
t = args.pop(0)
if t not in types:
usage(f"Unknown message type requested: {t}")
message_type = MessageTypes[t]
msg_cls = coreapi.CLASS_MAP[message_type.value]
tlv_cls = msg_cls.tlv_class
# list TLV types for this message type
if opt.tlvs:
print_available_tlvs(t, tlv_cls)
sys.exit(0)
# build a message consisting of TLVs from "type=value" arguments
flagstr = ""
tlvdata = b""
for a in args:
typevalue = a.split("=")
if len(typevalue) < 2:
usage(f"Use \"type=value\" syntax instead of \"{a}\".")
tlv_typestr = typevalue[0]
tlv_valstr = "=".join(typevalue[1:])
if tlv_typestr == "flags":
flagstr = tlv_valstr
continue
tlv_name = tlv_typestr
try:
tlv_type = tlv_cls.tlv_type_map[tlv_name]
tlvdata += tlv_cls.pack_string(tlv_type.value, tlv_valstr)
except KeyError:
usage(f"Unknown TLV: \"{tlv_name}\"")
flags = 0
for f in flagstr.split(","):
if f == "":
continue
try:
flag_enum = MessageFlags[f]
n = flag_enum.value
flags |= n
except KeyError:
usage(f"Invalid flag \"{f}\".")
msg = msg_cls.pack(flags, tlvdata)
if opt.tcp:
protocol = socket.SOCK_STREAM
else:
protocol = socket.SOCK_DGRAM
sock = socket.socket(socket.AF_INET, protocol)
sock.setblocking(True)
try:
sock.connect((opt.address, opt.port))
except Exception as e:
print(f"Error connecting to {opt.address}:{opt.port}:\n\t{e}")
sys.exit(1)
if opt.tcp and not connect_to_session(sock, opt.session):
print("warning: continuing without joining a session!")
sock.sendall(msg)
if opt.listen:
receive_response(sock, opt)
if opt.tcp:
sock.shutdown(socket.SHUT_RDWR)
sock.close()
sys.exit(0)
if __name__ == "__main__":
main()