3 # Copyright 2005,2006 Free Software Foundation, Inc.
5 # This file is part of GNU Radio
7 # GNU Radio is free software; you can redistribute it and/or modify
8 # it under the terms of the GNU General Public License as published by
9 # the Free Software Foundation; either version 2, or (at your option)
12 # GNU Radio is distributed in the hope that it will be useful,
13 # but WITHOUT ANY WARRANTY; without even the implied warranty of
14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 # GNU General Public License for more details.
17 # You should have received a copy of the GNU General Public License
18 # along with GNU Radio; see the file COPYING. If not, write to
19 # the Free Software Foundation, Inc., 51 Franklin Street,
20 # Boston, MA 02110-1301, USA.
24 # /////////////////////////////////////////////////////////////////////////////
26 # This code sets up up a virtual ethernet interface (typically gr0),
27 # and relays packets between the interface and the GNU Radio PHY+MAC
29 # What this means in plain language, is that if you've got a couple
30 # of USRPs on different machines, and if you run this code on those
31 # machines, you can talk between them using normal TCP/IP networking.
33 # /////////////////////////////////////////////////////////////////////////////
36 from gnuradio import gr, gru, modulation_utils
37 from gnuradio import usrp
38 from gnuradio import eng_notation
39 from gnuradio.eng_option import eng_option
40 from optparse import OptionParser
49 from transmit_path import transmit_path
50 from receive_path import receive_path
54 #raw_input('Attach and press enter')
57 # /////////////////////////////////////////////////////////////////////////////
59 # Use the Universal TUN/TAP device driver to move packets to/from kernel
61 # See /usr/src/linux/Documentation/networking/tuntap.txt
63 # /////////////////////////////////////////////////////////////////////////////
66 # TUNSETIFF ifr flags from <linux/tun_if.h>
68 IFF_TUN = 0x0001 # tunnel IP packets
69 IFF_TAP = 0x0002 # tunnel ethernet frames
70 IFF_NO_PI = 0x1000 # don't pass extra packet info
71 IFF_ONE_QUEUE = 0x2000 # beats me ;)
73 def open_tun_interface(tun_device_filename):
74 from fcntl import ioctl
76 mode = IFF_TAP | IFF_NO_PI
77 TUNSETIFF = 0x400454ca
79 tun = os.open(tun_device_filename, os.O_RDWR)
80 ifs = ioctl(tun, TUNSETIFF, struct.pack("16sH", "gr%d", mode))
81 ifname = ifs[:16].strip("\x00")
85 # /////////////////////////////////////////////////////////////////////////////
87 # /////////////////////////////////////////////////////////////////////////////
89 class my_graph(gr.flow_graph):
91 def __init__(self, mod_class, demod_class,
92 rx_callback, options):
94 gr.flow_graph.__init__(self)
95 self.txpath = transmit_path(self, mod_class, options)
96 self.rxpath = receive_path(self, demod_class, rx_callback, options)
98 def send_pkt(self, payload='', eof=False):
99 return self.txpath.send_pkt(payload, eof)
101 def carrier_sensed(self):
103 Return True if the receive path thinks there's carrier
105 return self.rxpath.carrier_sensed()
108 # /////////////////////////////////////////////////////////////////////////////
110 # /////////////////////////////////////////////////////////////////////////////
112 class cs_mac(object):
114 Prototype carrier sense MAC
116 Reads packets from the TUN/TAP interface, and sends them to the PHY.
117 Receives packets from the PHY via phy_rx_callback, and sends them
118 into the TUN/TAP interface.
120 Of course, we're not restricted to getting packets via TUN/TAP, this
123 def __init__(self, tun_fd, verbose=False):
124 self.tun_fd = tun_fd # file descriptor for TUN/TAP interface
125 self.verbose = verbose
126 self.fg = None # flow graph (access to PHY)
128 def set_flow_graph(self, fg):
131 def phy_rx_callback(self, ok, payload):
133 Invoked by thread associated with PHY to pass received packet up.
135 @param ok: bool indicating whether payload CRC was OK
136 @param payload: contents of the packet (string)
139 print "Rx: ok = %r len(payload) = %4d" % (ok, len(payload))
141 os.write(self.tun_fd, payload)
146 Only returns if we get an error reading from TUN.
148 FIXME: may want to check for EINTR and EAGAIN and reissue read
150 min_delay = 0.001 # seconds
153 payload = os.read(self.tun_fd, 10*1024)
155 self.fg.send_pkt(eof=True)
159 print "Tx: len(payload) = %4d" % (len(payload),)
162 while self.fg.carrier_sensed():
163 sys.stderr.write('B')
166 delay = delay * 2 # exponential back-off
168 self.fg.send_pkt(payload)
171 # /////////////////////////////////////////////////////////////////////////////
173 # /////////////////////////////////////////////////////////////////////////////
177 mods = modulation_utils.type_1_mods()
178 demods = modulation_utils.type_1_demods()
180 parser = OptionParser (option_class=eng_option, conflict_handler="resolve")
181 expert_grp = parser.add_option_group("Expert")
183 parser.add_option("-m", "--modulation", type="choice", choices=mods.keys(),
185 help="Select modulation from: %s [default=%%default]"
186 % (', '.join(mods.keys()),))
188 parser.add_option("-v","--verbose", action="store_true", default=False)
189 expert_grp.add_option("-c", "--carrier-threshold", type="eng_float", default=30,
190 help="set carrier detect threshold (dB) [default=%default]")
191 expert_grp.add_option("","--tun-device-filename", default="/dev/net/tun",
192 help="path to tun device file [default=%default]")
194 transmit_path.add_options(parser, expert_grp)
195 receive_path.add_options(parser, expert_grp)
197 for mod in mods.values():
198 mod.add_options(expert_grp)
200 for demod in demods.values():
201 demod.add_options(expert_grp)
203 fusb_options.add_options(expert_grp)
205 (options, args) = parser.parse_args ()
207 parser.print_help(sys.stderr)
210 if options.rx_freq is None or options.tx_freq is None:
211 sys.stderr.write("You must specify -f FREQ or --freq FREQ\n")
212 parser.print_help(sys.stderr)
215 # open the TUN/TAP interface
216 (tun_fd, tun_ifname) = open_tun_interface(options.tun_device_filename)
218 # Attempt to enable realtime scheduling
219 r = gr.enable_realtime_scheduling()
224 print "Note: failed to enable realtime scheduling"
227 # If the user hasn't set the fusb_* parameters on the command line,
228 # pick some values that will reduce latency.
230 if options.fusb_block_size == 0 and options.fusb_nblocks == 0:
231 if realtime: # be more aggressive
232 options.fusb_block_size = gr.prefs().get_long('fusb', 'rt_block_size', 1024)
233 options.fusb_nblocks = gr.prefs().get_long('fusb', 'rt_nblocks', 16)
235 options.fusb_block_size = gr.prefs().get_long('fusb', 'block_size', 4096)
236 options.fusb_nblocks = gr.prefs().get_long('fusb', 'nblocks', 16)
238 #print "fusb_block_size =", options.fusb_block_size
239 #print "fusb_nblocks =", options.fusb_nblocks
241 # instantiate the MAC
242 mac = cs_mac(tun_fd, verbose=True)
245 # build the graph (PHY)
246 fg = my_graph(mods[options.modulation],
247 demods[options.modulation],
251 mac.set_flow_graph(fg) # give the MAC a handle for the PHY
253 if fg.txpath.bitrate() != fg.rxpath.bitrate():
254 print "WARNING: Transmit bitrate = %sb/sec, Receive bitrate = %sb/sec" % (
255 eng_notation.num_to_str(fg.txpath.bitrate()),
256 eng_notation.num_to_str(fg.rxpath.bitrate()))
258 print "modulation: %s" % (options.modulation,)
259 print "freq: %s" % (eng_notation.num_to_str(options.tx_freq))
260 print "bitrate: %sb/sec" % (eng_notation.num_to_str(fg.txpath.bitrate()),)
261 print "samples/symbol: %3d" % (fg.txpath.samples_per_symbol(),)
262 #print "interp: %3d" % (fg.txpath.interp(),)
263 #print "decim: %3d" % (fg.rxpath.decim(),)
265 fg.rxpath.set_carrier_threshold(options.carrier_threshold)
266 print "Carrier sense threshold:", options.carrier_threshold, "dB"
269 print "Allocated virtual ethernet interface: %s" % (tun_ifname,)
270 print "You must now use ifconfig to set its IP address. E.g.,"
272 print " $ sudo ifconfig %s 192.168.200.1" % (tun_ifname,)
274 print "Be sure to use a different address in the same subnet for each machine."
278 fg.start() # Start executing the flow graph (runs in separate threads)
280 mac.main_loop() # don't expect this to return...
282 fg.stop() # but if it does, tell flow graph to stop.
283 fg.wait() # wait for it to finish
286 if __name__ == '__main__':
289 except KeyboardInterrupt: