+import base64
import errno
import os
import time
+import passfd
import signal
import socket
import tunchannel
-import struct
-import fcntl
from optparse import OptionParser
+PASSFD_MSG = "PASSFD"
+
IFF_TUN = 0x0001
IFF_TAP = 0x0002
IFF_NO_PI = 0x1000
SUSPEND.remove(None)
signal.signal(signal.SIGUSR2, _resume)
-def open_tap(vif_name, vif_type, pi):
- flags = 0
- flags |= vif_type
-
- if not pi:
- flags |= IFF_NO_PI
-
- fd = os.open("/dev/net/tun", os.O_RDWR)
-
- err = fcntl.ioctl(fd, TUNSETIFF, struct.pack("16sH", vif_name, flags))
- if err < 0:
- os.close(fd)
- raise RuntimeError("Could not configure device %s" % vif_name)
+def get_fd(socket_name):
+ # Socket to recive the file descriptor
+ fdsock = socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM)
+ fdsock.bind("")
+ address = fdsock.getsockname()
+
+ # Socket to connect to the pl-vif-create process
+ # and send the PASSFD message
+ sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
+ sock.connect(socket_name)
+ emsg = base64.b64encode(PASSFD_MSG)
+ eargs = base64.b64encode(address)
+ encoded = "%s|%s\n" % (emsg, eargs)
+ sock.send(encoded)
+
+ # Receive fd
+ (fd, msg) = passfd.recvfd(fdsock)
+
+ # Receive reply
+ reply = sock.recv(1024)
+ reply = base64.b64decode(reply)
+ sock.close()
+ fdsock.close()
return fd
def get_options():
- usage = ("usage: %prog -N <vif_name> -t <vif-type> -p <pi> "
+ usage = ("usage: %prog -t <vif-type> -S <fd-socket-name> -n <pi> "
"-b <bwlimit> -c <cipher> -k <cipher-key> -q <txqueuelen> "
- "-l <local-port-file> -r <remote-port-file> -H <remote-host> "
+ "-p <local-port-file> -P <remote-port-file> "
+ "-o <local-ip> -P <remote-ip> "
"-R <ret-file> ")
parser = OptionParser(usage = usage)
- parser.add_option("-N", "--vif-name", dest="vif_name",
- help = "The name of the virtual interface",
- type="str")
-
parser.add_option("-t", "--vif-type", dest="vif_type",
help = "Virtual interface type. Either IFF_TAP or IFF_TUN. "
- "Defaults to IFF_TAP. ",
- default = IFF_TAP,
- type="str")
-
- parser.add_option("-n", "--pi", dest="pi",
- action="store_true",
- default = False,
- help="Enable PI header")
+ "Defaults to IFF_TAP. ", type="str")
+ parser.add_option("-S", "--fd-socket-name", dest="fd_socket_name",
+ help = "Name for the unix socket to request the TAP file descriptor",
+ default = "tap.sock", type="str")
+ parser.add_option("-n", "--pi", dest="pi", action="store_true",
+ default=False, help="Enable PI header")
parser.add_option("-b", "--bwlimit", dest="bwlimit",
help = "Specifies the interface's emulated bandwidth in bytes ",
default = None, type="int")
-
parser.add_option("-q", "--txqueuelen", dest="txqueuelen",
help = "Specifies the interface's transmission queue length. ",
default = 1000, type="int")
-
parser.add_option("-c", "--cipher", dest="cipher",
help = "Cipher to encript communication. "
"One of PLAIN, AES, Blowfish, DES, DES3. ",
default = None, type="str")
-
parser.add_option("-k", "--cipher-key", dest="cipher_key",
help = "Specify a symmetric encryption key with which to protect "
"packets across the tunnel. python-crypto must be installed "
"on the system." ,
default = None, type="str")
- parser.add_option("-l", "--local-port-file", dest="local_port_file",
+ parser.add_option("-p", "--local-port-file", dest="local_port_file",
help = "File where to store the local binded UDP port number ",
default = "local_port_file", type="str")
-
- parser.add_option("-r", "--remote-port-file", dest="remote_port_file",
+ parser.add_option("-P", "--remote-port-file", dest="remote_port_file",
help = "File where to read the remote UDP port number to connect to",
default = "remote_port_file", type="str")
-
- parser.add_option("-H", "--remote-host", dest="remote_host",
- help = "Remote host IP",
- default = "remote_host", type="str")
-
+ parser.add_option("-o", "--local-ip", dest="local_ip",
+ help = "Local host IP", default = "local_host", type="str")
+ parser.add_option("-O", "--remote-ip", dest="remote_ip",
+ help = "Remote host IP", default = "remote_host", type="str")
parser.add_option("-R", "--ret-file", dest="ret_file",
help = "File where to store return code (success of connection) ",
default = "ret_file", type="str")
(options, args) = parser.parse_args()
- if options.vif_type == "IFF_TUN":
+ vif_type = IFF_TAP
+ if options.vif_type and options.vif_type == "IFF_TUN":
vif_type = IFF_TUN
- return ( options.vif_name, vif_type, options.pi,
+ return (vif_type, options.pi, options.fd_socket_name,
options.local_port_file, options.remote_port_file,
- options.remote_host, options.ret_file, options.bwlimit,
- options.cipher, options.cipher_key, options.txqueuelen )
+ options.local_ip, options.remote_ip, options.ret_file,
+ options.bwlimit, options.cipher, options.cipher_key,
+ options.txqueuelen )
if __name__ == '__main__':
+ ( vif_type, pi, socket_name, local_port_file, remote_port_file,
+ local_ip, remote_ip, ret_file, bwlimit, cipher, cipher_key,
+ txqueuelen ) = get_options()
- ( vif_name, vif_type, pi, local_port_file, remote_port_file,
- remote_host, ret_file, bwlimit, cipher, cipher_key, txqueuelen
- ) = get_options()
-
# Get the file descriptor of the TAP device from the process
# that created it
- fd = open_tap(vif_name, vif_type, pi)
+ fd = get_fd(socket_name)
+ tun = os.fdopen(fd, 'r+b', 0)
# Create a local socket to stablish the tunnel connection
- hostaddr = socket.gethostbyname(socket.gethostname())
sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, 0)
- sock.bind((hostaddr, 0))
+ sock.bind((local_ip, 0))
(local_host, local_port) = sock.getsockname()
# Save local port information to file
- f = open(local_port_file, 'w')
- f.write("%d\n" % local_port)
- f.close()
+ with open(local_port_file, 'w') as f:
+ f.write("%d\n" % local_port)
# Wait until remote port information is available
while not os.path.exists(remote_port_file):
# the read operation returns empty string!
# Maybe a race condition?
for i in xrange(10):
- f = open(remote_port_file, 'r')
- remote_port = f.read()
- f.close()
+ with open(remote_port_file, 'r') as f:
+ remote_port = f.read()
if remote_port:
break
remote_port = int(remote_port)
# Connect local socket to remote port
- sock.connect((remote_host, remote_port))
+ sock.connect((remote_ip, remote_port))
remote = os.fdopen(sock.fileno(), 'r+b', 0)
# TODO: Test connectivity!
# Create a ret_file to indicate success
- f = open(ret_file, 'w')
- f.write("0")
- f.close()
+ with open(ret_file, 'w') as f:
+ f.write("0")
# Establish tunnel
tunchannel.tun_fwd(tun, remote,
- with_pi = True, # Planetlab TAP devices add PI headers
+ with_pi = pi, # Planetlab TAP devices add PI headers
ether_mode = (vif_type == IFF_TAP),
udp = True,
cipher_key = cipher_key,