2 # NEPI, a framework to manage network experiments
3 # Copyright (C) 2013 INRIA
5 # This program is free software: you can redistribute it and/or modify
6 # it under the terms of the GNU General Public License as published by
7 # the Free Software Foundation, either version 3 of the License, or
8 # (at your option) any later version.
10 # This program is distributed in the hope that it will be useful,
11 # but WITHOUT ANY WARRANTY; without even the implied warranty of
12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 # GNU General Public License for more details.
15 # You should have received a copy of the GNU General Public License
16 # along with this program. If not, see <http://www.gnu.org/licenses/>.
18 # Author: Alina Quereilhac <alina.quereilhac@inria.fr>
25 from optparse import OptionParser
30 def create_socket(socket_name):
31 sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
32 sock.bind(socket_name)
39 while '\n' not in chunk:
41 chunk = conn.recv(1024)
42 except (OSError, socket.error), e:
43 if e[0] != errno.EINTR:
54 msg = ''.join(msg).split('\n')[0]
55 # The message might have arguments that will be appended
56 # as a '|' separated list after the message type
60 dmsg = base64.b64decode(msg)
63 darg = base64.b64decode(arg)
64 dargs.append(darg.rstrip())
66 return (dmsg.rstrip(), dargs)
68 def send_reply(conn, reply):
69 encoded = base64.b64encode(reply)
70 conn.send("%s\n" % encoded)
75 def passfd_action(fd, args):
76 """ Sends the file descriptor associated to the TAP device
77 to another process through a unix socket.
81 sock = socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM)
83 passfd.sendfd(sock, fd, '0')
87 usage = ("usage: %prog -t <vif-type> -a <ip4-address> -n <net-prefix> "
88 "-s <snat> -p <pointopoint> -q <txqueuelen> -f <vif-name-file> "
91 parser = OptionParser(usage = usage)
93 parser.add_option("-t", "--vif-type", dest="vif_type",
94 help = "Virtual interface type. Either IFF_TAP or IFF_TUN. "
95 "Defaults to IFF_TAP. ", type="str")
97 parser.add_option("-a", "--ip4-address", dest="ip4_address",
98 help = "IPv4 address to assign to interface. It must belong to the "
99 "network segment owned by the slice, given by the vsys_vnet tag. ",
102 parser.add_option("-n", "--net-prefix", dest="net_prefix",
103 help = "IPv4 network prefix for the interface. It must be the one "
104 "given by the slice's vsys_vnet tag. ",
107 parser.add_option("-s", "--snat", dest="snat", default = False,
108 action="store_true", help="Enable SNAT for the interface")
110 parser.add_option("-p", "--pointopoint", dest="pointopoint",
111 help = "Peer end point for the interface ", default = None,
114 parser.add_option("-q", "--txqueuelen", dest="txqueuelen",
115 help = "Size of transmision queue. Defaults to 0.",
119 parser.add_option("-f", "--vif-name-file", dest="vif_name_file",
120 help = "File to store the virtual interface name assigned by the OS",
121 default = "if_name", type="str")
123 parser.add_option("-S", "--socket-name", dest="socket_name",
124 help = "Name for the unix socket used to interact with this process",
125 default = "tap.sock", type="str")
127 (options, args) = parser.parse_args()
129 vif_type = vsys.IFF_TAP
130 if options.vif_type and options.vif_type == "IFF_TUN":
131 vif_type = vsys.IFF_TUN
133 return (vif_type, options.ip4_address, options.net_prefix,
134 options.snat, options.pointopoint, options.txqueuelen,
135 options.vif_name_file, options.socket_name)
137 if __name__ == '__main__':
139 (vif_type, ip4_address, net_prefix, snat, pointopoint,
140 txqueuelen, vif_name_file, socket_name) = get_options()
142 (fd, vif_name) = vsys.fd_tuntap(vif_type)
144 vsys.vif_up(vif_name, ip4_address, net_prefix, snat = snat,
145 pointopoint = pointopoint, txqueuelen = txqueuelen)
147 # Saving interface name to 'if_name_file
148 f = open(vif_name_file, 'w')
152 # create unix socket to receive instructions
153 sock = create_socket(socket_name)
156 # wait for messages to arrive and process them
160 conn, addr = sock.accept()
165 (msg, args) = recv_msg(conn)
166 except socket.timeout, e:
171 # Ignore - connection lost
176 reply = stop_action()
177 elif msg == PASSFD_MSG:
178 reply = passfd_action(fd, args)
181 send_reply(conn, reply)