#!/usr/bin/env python
"""
Simple (limited) netcat-like example, implemented using the socket/lib.event2 layer.
"""
from qmsk.net.socket import socket, address
from qmsk.net.socket.constants import *
from qmsk.net.lib.event2 import base, event
from qmsk.net.lib.event2.constants import *
from qmsk.net.lib.event2.event import CallbackEvent as cb_event
import sys, os, fcntl, errno
import optparse
# global options
options = None
# global event_base
ev_base = base.event_base()
# buffer size to use, 4k - perhaps slightly smaller
BUFSIZE = 4 * 1024
def parse_argv (argv) :
global options
prog = argv.pop(0)
parser = optparse.OptionParser(prog=prog)
parser.add_option('-4', "--ipv4", help="Force AF_INET", action='store_true')
parser.add_option('-6', "--ipv6", help="Force AF_INET6", action='store_true')
parser.add_option('-v', "--verbose", help="Display status output", action='store_true')
parser.add_option('-d', "--debug", help="Display extra output", action='store_true')
parser.add_option('-w', "--timeout", help="Timeout for connect()", type='float')
options, args = parser.parse_args(argv)
if options.ipv4 and options.ipv6 :
raise Exception("-4 and -6 are mutually exclusive!")
if options.debug :
# enable both
options.verbose = True
return args
def log_msg (prefix, msg, *args) :
if args :
msg = msg % args
sys.stderr.write("%s %s\n" % (prefix, msg))
def log_err (msg, *args) :
log_msg('!!!', msg, *args)
def log_warn (msg, *args) :
log_msg('+++', msg, *args)
def log_info (msg, *args) :
if options.verbose :
log_msg('***', msg, *args)
def log_debug (msg, *args) :
if options.debug :
log_msg('---', msg, *args)
def setnonblocking (file) :
"""
Set the non-blocking IO flag on the given file object
"""
fcntl.fcntl(file.fileno(), fcntl.F_SETFL, os.O_NONBLOCK)
def sock_connect (host, port, family, socktype) :
"""
Try and perform a series of non-blocking connects to the given host:port using the given family and socktype,
yielding a series of socket objects.
"""
for ai in address.getaddrinfo(host, port, family, socktype) :
log_info("sock_connect: ai: %s", ai)
# build socket
try :
# construct
log_debug("sock_connect: socket(%d, %d, %d)", ai.family, ai.socktype, ai.protocol)
sock = socket.socket(ai.family, ai.socktype, ai.protocol)
log_debug("sock_connect: socket=%s", sock)
# set nonblock mode
log_debug("sock_connect: setnonblocking(%s)", sock)
setnonblocking(sock)
# start connect
try :
log_debug("sock_connect: connect(%s)", ai.addr)
sock.connect(ai.addr)
except OSError, e :
if e.errno != errno.EINPROGRESS :
raise
else :
# XXX: wut???
log_warn("sock_connect: connect: didn't return EINPROGRESS")
except OSError, e :
# fsck
log_warn("sock_connect: %s: %s", ai.addr, e)
else :
# yay
yield sock
def client_connect_next (sock_iter) :
"""
Attempt to run the given connect operation, on the given iterable of sockets.
"""
for sock in sock_iter :
# pend for writing
log_debug("client_connect_next: cb_event(%d, EV_WRITE, on_connect, %r)", sock.fd, sock)
ev = cb_event(ev_base, sock.fd, EV_WRITE, on_connect, sock, sock_iter)
# wait specified timeout
log_debug("client_connect_next: %r: add(%s)", ev, options.timeout)
ev.add(options.timeout)
# ok
break
else :
# fail, ran out of addresses to try
log_err("client_connect_next: ran out of addresses to try")
def on_connect (ev, events, sock, sock_iter) :
"""
Outbound connect EV_WRITE callback, i.e. connection failed or was established
"""
log_debug("on_connect: ev=%r, events=%#x", ev, events)
# test for timeout
if events & EV_TIMEOUT :
log_warn("on_connect: connect failed, timeout")
# keep trying
return client_connect_next(sock_iter)
# test for errno
err = sock.getsockopt_int(SOL_SOCKET, SO_ERROR)
if err :
# fail
log_warn("on_connect: connect failed, errno=%d", err)
# keep trying
return client_connect_next(sock_iter)
# ok, connected
client_connected(sock)
def client_connected (sock) :
"""
Connection established, start shovelling data
"""
log_info("Client connected to %s (from %s)", sock.getpeername(), sock.getsockname())
# go!
start_sock(sock, sys.stdin.fileno(), sys.stdout.fileno())
def start_sock (sock, fd_in, fd_out) :
"""
Start shipping data between sock and fin/fout.
"""
# event for each
ev_in = cb_event(ev_base, fd_in, EV_READ, on_read_in, sock, fd_in)
ev_out = cb_event(ev_base, sock.fd, EV_READ, on_read_sock, sock, fd_out)
ev_in.add()
ev_out.add()
def on_read_in (ev, events, sock, fd_in) :
"""
Data readable on ev.fd, ship to sock
"""
# no timeouts yet
assert events & EV_READ
# try and read
buf = os.read(fd_in, BUFSIZE)
if buf :
# pass on
assert sock.write(buf) == len(buf)
# keep going
ev.add()
else :
# EOF
sock.shutdown(SHUT_WR)
def on_read_sock (ev, events, sock, fd_out) :
"""
Data readable on sock, ship to fd_out
"""
# no timeouts yet
assert events & EV_READ
# try and read
buf = sock.read(BUFSIZE)
if buf :
# pass on
assert os.write(fd_out, buf) == len(buf)
# keep going
ev.add()
else :
# EOF
os.close(fd_out)
log_info("EOF from %s", sock.getpeername())
def run_client (host, port) :
"""
Execute in client-mode
"""
# figure out AF to use
if options.ipv4 :
family = AF_INET
elif options.ipv6 :
family = AF_INET6
else :
family = AF_UNSPEC
# fixed socktype
socktype = SOCK_STREAM
# look up the address and start a non-blocking connect
sock_iter = sock_connect(host, port, family, socktype)
# start waiting
client_connect_next(sock_iter)
def main (argv) :
# parse args
args = parse_argv(argv)
# XXX: support listen mode
host, port = args
run_client(host, port)
# run mainloop
log_debug("main: entering event loop")
if ev_base.loop() :
log_debug("main: event loop done")
else :
log_err("main: event loop was idle!")
if __name__ == '__main__' :
main(sys.argv)