[Discuss-gnuradio] Issue with tuntap_pdu

[Jonathan Fox]

I am trying to run the example simple_trx.py script from the gr-mac module and I am having an issue related to what I believe is gr::blocks::tuntap_pdu.

This is what I am doing.

I open up a couple of terminal windows and in two of them I place in these separate commands.

address@hidden project]# ./simple_trx.py --radio-addr 85 --dest-addr 86 --port 12345 -a addr=10.2.8.104

address@hidden project]# ./simple_trx.py --radio-addr 86 --dest-addr 85 --port 12346 -a addr=10.2.8.105

The former will run just fine and then the second one gives me this error

address@hidden project]# ./simple_trx.py --radio-addr 86 --dest-addr 85 --port 12346 -a addr=10.2.8.105
linux; GNU C++ version 4.4.7 20120313 (Red Hat 4.4.7-4); Boost_104100; UHD_003.007.001-64-g92b0b7ab

libGL error: failed to load driver: nouveau
libGL error: Try again with LIBGL_DEBUG=verbose for more details.
Using Volk machine: sse4_2_64
Simple MAC ARQ in non-blocking mode
<virtual_channel_encoder[25]> MTU: 128
'post_msg' not found. Using 'message_port_pub' instead.
Virtual channel encoder in non-blocking mode
<virtual_channel_encoder[26]> MTU: 128
'post_msg' not found. Using 'message_port_pub' instead.
Virtual channel encoder in non-blocking mode
-- Opening a USRP2/N-Series device...
-- Current recv frame size: 1472 bytes
-- Current send frame size: 1472 bytes
-- Detecting internal GPSDO.... Found an internal GPSDO
-- found
-- Setting references to the internal GPSDO
-- Initializing time to the internal GPSDO
<burst_tagger[36]> tag name: length, multiplier: 32.000000, tag front: 0, tag rear: 16, drop residue: yes, verbose: yes
bits per symbol = 1
M&M clock recovery omega = 4.000000
M&M clock recovery gain mu = 0.175000
M&M clock recovery mu = 0.500000
M&M clock recovery omega rel. limit = 0.005000
frequency error = 0.000000
Traceback (most recent call last):
  File "./simple_trx.py", line 386, in <module>
    tb = simple_trx(args=options.args, tx_lo_offset=options.tx_lo_offset, rx_lo_offset=options.rx_lo_offset, rate=options.rate, rx_antenna=options.rx_antenna, rx_freq=options.rx_freq, tx_freq=options.tx_freq, rx_gain=options.rx_gain, tx_gain=options.tx_gain, samps_per_sym=options.samps_per_sym, ampl=options.ampl, arq_timeout=options.arq_timeout, dest_addr=options.dest_addr, max_arq_attempts=options.max_arq_attempts, radio_addr=options.radio_addr, iface=options.iface, mtu=options.mtu, port=options.port)
  File "./simple_trx.py", line 157, in __init__
    self.blocks_tuntap_pdu_0 = blocks.tuntap_pdu(iface, mtu*0 + 1514)
  File "/usr/local/lib64/python2.6/site-packages/gnuradio/blocks/blocks_swig5.py", line 1796, in make
    return _blocks_swig5.tuntap_pdu_make(*args, **kwargs)
RuntimeError: gr::tuntap_pdu::make: tun_alloc failed (are you running as root?)

Of course I am running this as root. Why can't I have two instances of this running?

Jonathan Fox