From 28e086141aead2e43f958f0ae14d58cac557fa2d Mon Sep 17 00:00:00 2001
From: trondeau <trondeau@221aa14e-8319-0410-a670-987f0aec2ac5>
Date: Wed, 7 Mar 2007 04:31:19 +0000
Subject: merged trondeau/digital-wip2 r4193:4730 into trunk - improves digital
receiver and fixes ticket:72
git-svn-id: http://gnuradio.org/svn/gnuradio/trunk@4731 221aa14e-8319-0410-a670-987f0aec2ac5
---
gnuradio-examples/python/hier/digital/tunnel.py | 290 ++++++++++++++++++++++++
1 file changed, 290 insertions(+)
create mode 100755 gnuradio-examples/python/hier/digital/tunnel.py
(limited to 'gnuradio-examples/python/hier/digital/tunnel.py')
diff --git a/gnuradio-examples/python/hier/digital/tunnel.py b/gnuradio-examples/python/hier/digital/tunnel.py
new file mode 100755
index 0000000000..56229f5360
--- /dev/null
+++ b/gnuradio-examples/python/hier/digital/tunnel.py
@@ -0,0 +1,290 @@
+#!/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, modulation_utils
+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,
+ rx_callback, options):
+
+ gr.flow_graph.__init__(self)
+ self.txpath = transmit_path(self, mod_class, options)
+ self.rxpath = receive_path(self, demod_class, 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():
+
+ mods = modulation_utils.type_1_mods()
+ demods = modulation_utils.type_1_demods()
+
+ parser = OptionParser (option_class=eng_option, conflict_handler="resolve")
+ expert_grp = parser.add_option_group("Expert")
+
+ parser.add_option("-m", "--modulation", type="choice", choices=mods.keys(),
+ default='gmsk',
+ help="Select modulation from: %s [default=%%default]"
+ % (', '.join(mods.keys()),))
+
+ parser.add_option("-v","--verbose", action="store_true", default=False)
+ expert_grp.add_option("-c", "--carrier-threshold", type="eng_float", default=30,
+ help="set carrier detect threshold (dB) [default=%default]")
+ expert_grp.add_option("","--tun-device-filename", default="/dev/net/tun",
+ help="path to tun device file [default=%default]")
+
+ transmit_path.add_options(parser, expert_grp)
+ receive_path.add_options(parser, expert_grp)
+
+ for mod in mods.values():
+ mod.add_options(expert_grp)
+
+ for demod in demods.values():
+ demod.add_options(expert_grp)
+
+ fusb_options.add_options(expert_grp)
+
+ (options, args) = parser.parse_args ()
+ if len(args) != 0:
+ parser.print_help(sys.stderr)
+ sys.exit(1)
+
+ if options.rx_freq is None or options.tx_freq is None:
+ sys.stderr.write("You must specify -f FREQ or --freq FREQ\n")
+ parser.print_help(sys.stderr)
+ sys.exit(1)
+
+ # 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(mods[options.modulation],
+ demods[options.modulation],
+ mac.phy_rx_callback,
+ options)
+
+ 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 "modulation: %s" % (options.modulation,)
+ print "freq: %s" % (eng_notation.num_to_str(options.tx_freq))
+ print "bitrate: %sb/sec" % (eng_notation.num_to_str(fg.txpath.bitrate()),)
+ print "samples/symbol: %3d" % (fg.txpath.samples_per_symbol(),)
+ #print "interp: %3d" % (fg.txpath.interp(),)
+ #print "decim: %3d" % (fg.rxpath.decim(),)
+
+ 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 192.168.200.1" % (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
--
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