#!/usr/bin/env python
#
# Copyright 2005,2006 Free Software Foundation, Inc.
#
# This file is part of GNU Radio
#
# GNU Radio is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2, or (at your option)
# any later version.
#
# GNU Radio is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with GNU Radio; see the file COPYING. If not, write to
# the Free Software Foundation, Inc., 51 Franklin Street,
# Boston, MA 02110-1301, USA.
#
# /////////////////////////////////////////////////////////////////////////////
#
# This code sets up up a virtual ethernet interface (typically gr0),
# and relays packets between the interface and the GNU Radio PHY+MAC
#
# What this means in plain language, is that if you've got a couple
# of USRPs on different machines, and if you run this code on those
# machines, you can talk between them using normal TCP/IP networking.
#
# /////////////////////////////////////////////////////////////////////////////
from gnuradio import gr, gru, blks
from gnuradio import usrp
from gnuradio import eng_notation
from gnuradio.eng_option import eng_option
from optparse import OptionParser
import random
import time
import struct
import sys
import os
# from current dir
from transmit_path import transmit_path
from receive_path import receive_path
import fusb_options
#print os.getpid()
#raw_input('Attach and press enter')
# /////////////////////////////////////////////////////////////////////////////
#
# Use the Universal TUN/TAP device driver to move packets to/from kernel
#
# See /usr/src/linux/Documentation/networking/tuntap.txt
#
# /////////////////////////////////////////////////////////////////////////////
# Linux specific...
# TUNSETIFF ifr flags from <linux/tun_if.h>
IFF_TUN = 0x0001 # tunnel IP packets
IFF_TAP = 0x0002 # tunnel ethernet frames
IFF_NO_PI = 0x1000 # don't pass extra packet info
IFF_ONE_QUEUE = 0x2000 # beats me ;)
def open_tun_interface(tun_device_filename):
from fcntl import ioctl
mode = IFF_TAP | IFF_NO_PI
TUNSETIFF = 0x400454ca
tun = os.open(tun_device_filename, os.O_RDWR)
ifs = ioctl(tun, TUNSETIFF, struct.pack("16sH", "gr%d", mode))
ifname = ifs[:16].strip("\x00")
return (tun, ifname)
# /////////////////////////////////////////////////////////////////////////////
# the flow graph
# /////////////////////////////////////////////////////////////////////////////
class my_graph(gr.flow_graph):
def __init__(self, mod_class, demod_class,
tx_subdev_spec, rx_subdev_spec,
rx_callback,
options, kwargs):
gr.flow_graph.__init__(self)
self.txpath = transmit_path(self, mod_class, tx_subdev_spec,
options.bitrate, options.interp, options.spb,
options.tx_gain, options, kwargs)
self.rxpath = receive_path(self, demod_class, rx_subdev_spec,
options.bitrate, options.decim, options.spb,
rx_callback, options, {})
def send_pkt(self, payload='', eof=False):
return self.txpath.send_pkt(payload, eof)
def carrier_sensed(self):
"""
Return True if the receive path thinks there's carrier
"""
return self.rxpath.carrier_sensed()
# /////////////////////////////////////////////////////////////////////////////
# Carrier Sense MAC
# /////////////////////////////////////////////////////////////////////////////
class cs_mac(object):
"""
Prototype carrier sense MAC
Reads packets from the TUN/TAP interface, and sends them to the PHY.
Receives packets from the PHY via phy_rx_callback, and sends them
into the TUN/TAP interface.
Of course, we're not restricted to getting packets via TUN/TAP, this
is just an example.
"""
def __init__(self, tun_fd, verbose=False):
self.tun_fd = tun_fd # file descriptor for TUN/TAP interface
self.verbose = verbose
self.fg = None # flow graph (access to PHY)
def set_flow_graph(self, fg):
self.fg = fg
def phy_rx_callback(self, ok, payload):
"""
Invoked by thread associated with PHY to pass received packet up.
@param ok: bool indicating whether payload CRC was OK
@param payload: contents of the packet (string)
"""
if self.verbose:
print "Rx: ok = %r len(payload) = %4d" % (ok, len(payload))
if ok:
os.write(self.tun_fd, payload)
def main_loop(self):
"""
Main loop for MAC.
Only returns if we get an error reading from TUN.
FIXME: may want to check for EINTR and EAGAIN and reissue read
"""
min_delay = 0.001 # seconds
while 1:
payload = os.read(self.tun_fd, 10*1024)
if not payload:
self.fg.send_pkt(eof=True)
break
if self.verbose:
print "Tx: len(payload) = %4d" % (len(payload),)
delay = min_delay
while self.fg.carrier_sensed():
sys.stderr.write('B')
time.sleep(delay)
if delay < 0.050:
delay = delay * 2 # exponential back-off
self.fg.send_pkt(payload)
# /////////////////////////////////////////////////////////////////////////////
# main
# /////////////////////////////////////////////////////////////////////////////
def main():
parser = OptionParser (option_class=eng_option)
parser.add_option("-f", "--freq", type="eng_float", default=423.1e6,
help="set Tx and Rx frequency to FREQ [default=%default]",
metavar="FREQ")
parser.add_option("-r", "--bitrate", type="eng_float", default=None,
help="specify bitrate. spb and interp will be derived.")
parser.add_option("-g", "--rx-gain", type="eng_float", default=27,
help="set rx gain")
parser.add_option("-p", "--tx-gain", type="eng_float", default=100,
help="set tx gain")
parser.add_option("-T", "--tx-subdev-spec", type="subdev", default=None,
help="select USRP Tx side A or B")
parser.add_option("-R", "--rx-subdev-spec", type="subdev", default=None,
help="select USRP Rx side A or B")
parser.add_option("-S", "--spb", type="int", default=None,
help="set samples/baud [default=%default]")
parser.add_option("-d", "--decim", type="intx", default=None,
help="set fpga decim rate to DECIM [default=%default]")
parser.add_option("-i", "--interp", type="intx", default=None,
help="set fpga interpolation rate to INTERP [default=%default]")
parser.add_option("-c", "--carrier-threshold", type="eng_float", default=30,
help="set carrier detect threshold (dB) [default=%default]")
parser.add_option("", "--bt", type="float", default=0.3,
help="set bandwidth-time product [default=%default]")
parser.add_option("","--tun-device-filename", default="/dev/net/tun",
help="path to tun device file [default=%default]")
parser.add_option("-v","--verbose", action="store_true", default=False)
fusb_options.add_options(parser)
(options, args) = parser.parse_args ()
if len(args) != 0:
parser.print_help()
sys.exit(1)
if options.freq < 1e6:
options.freq *= 1e6
mod_kwargs = {
'bt' : options.bt,
}
# open the TUN/TAP interface
(tun_fd, tun_ifname) = open_tun_interface(options.tun_device_filename)
# Attempt to enable realtime scheduling
r = gr.enable_realtime_scheduling()
if r == gr.RT_OK:
realtime = True
else:
realtime = False
print "Note: failed to enable realtime scheduling"
# If the user hasn't set the fusb_* parameters on the command line,
# pick some values that will reduce latency.
if options.fusb_block_size == 0 and options.fusb_nblocks == 0:
if realtime: # be more aggressive
options.fusb_block_size = gr.prefs().get_long('fusb', 'rt_block_size', 1024)
options.fusb_nblocks = gr.prefs().get_long('fusb', 'rt_nblocks', 16)
else:
options.fusb_block_size = gr.prefs().get_long('fusb', 'block_size', 4096)
options.fusb_nblocks = gr.prefs().get_long('fusb', 'nblocks', 16)
print "fusb_block_size =", options.fusb_block_size
print "fusb_nblocks =", options.fusb_nblocks
# instantiate the MAC
mac = cs_mac(tun_fd, verbose=True)
# build the graph (PHY)
fg = my_graph(blks.gmsk2_mod, blks.gmsk2_demod,
options.tx_subdev_spec, options.rx_subdev_spec,
mac.phy_rx_callback,
options, mod_kwargs)
mac.set_flow_graph(fg) # give the MAC a handle for the PHY
if fg.txpath.bitrate() != fg.rxpath.bitrate():
print "WARNING: Transmit bitrate = %sb/sec, Receive bitrate = %sb/sec" % (
eng_notation.num_to_str(fg.txpath.bitrate()),
eng_notation.num_to_str(fg.rxpath.bitrate()))
print "bitrate: %sb/sec" % (eng_notation.num_to_str(fg.txpath.bitrate()),)
print "spb: %3d" % (fg.txpath.spb(),)
print "interp: %3d" % (fg.txpath.interp(),)
ok = fg.txpath.set_freq(options.freq)
if not ok:
print "Failed to set Tx frequency to %s" % (eng_notation.num_to_str(options.freq),)
raise SystemExit
ok = fg.rxpath.set_freq(options.freq)
if not ok:
print "Failed to set Rx frequency to %s" % (eng_notation.num_to_str(options.freq),)
raise SystemExit
print "Tx gain: ", options.tx_gain
fg.rxpath.set_gain(options.rx_gain)
print "Rx gain_range: ", fg.rxpath.subdev.gain_range(), " using", fg.rxpath.gain
fg.rxpath.set_carrier_threshold(options.carrier_threshold)
print "Carrier sense threshold:", options.carrier_threshold, "dB"
print
print "Allocated virtual ethernet interface: %s" % (tun_ifname,)
print "You must now use ifconfig to set its IP address. E.g.,"
print
print " $ sudo ifconfig %s 10.10.10.1" % (tun_ifname,)
print
print "Be sure to use a different address in the same subnet for each machine."
print
fg.start() # Start executing the flow graph (runs in separate threads)
mac.main_loop() # don't expect this to return...
fg.stop() # but if it does, tell flow graph to stop.
fg.wait() # wait for it to finish
if __name__ == '__main__':
try:
main()
except KeyboardInterrupt:
pass