PlanetlabTap reads STOP from unix socket

[nepi.git] / src / nepi / resources / planetlab / scripts / pl-vif-create.py

diff --git a/src/nepi/resources/planetlab/scripts/pl-vif-create.py b/src/nepi/resources/planetlab/scripts/pl-vif-create.py
new file mode 100644 (file)
index 0000000..758cfc4
--- /dev/null
+++ b/src/nepi/resources/planetlab/scripts/pl-vif-create.py
@@ -0,0 +1,157 @@
+#
+#    NEPI, a framework to manage network experiments
+#    Copyright (C) 2013 INRIA
+#
+#    This program 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 3 of the License, or
+#    (at your option) any later version.
+#
+#    This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+# Author: Alina Quereilhac <alina.quereilhac@inria.fr>
+
+import base64
+import errno
+import vsys
+import socket
+from optparse import OptionParser, SUPPRESS_HELP
+
+# TODO: GRE OPTION!! CONFIGURE THE VIF-UP IN GRE MODE!!
+
+STOP_MSG = "STOP"
+
+def create_socket(socket_name):
+    sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
+    sock.bind(socket_name)
+    return sock
+
+def recv_msg(conn):
+    msg = []
+    chunk = ''
+
+    while '\n' not in chunk:
+        try:
+            chunk = conn.recv(1024)
+        except (OSError, socket.error), e:
+            if e[0] != errno.EINTR:
+                raise
+            # Ignore eintr errors
+            continue
+
+        if chunk:
+            msg.append(chunk)
+        else:
+            # empty chunk = EOF
+            break
+
+    msg = ''.join(msg).split('\n')[0]
+    decoded = base64.b64decode(msg)
+    return decoded.rstrip()
+
+def send_reply(conn, reply):
+    encoded = base64.b64encode(reply)
+    conn.send("%s\n" % encoded)
+
+def stop_action():
+    return "STOP-ACK"
+
+def reply_action(msg):
+    return "Reply to: %s" % msg
+
+def get_options():
+    usage = ("usage: %prog -t <vif-type> -a <ip4-address> -n <net-prefix> "
+        "-s <snat> -p <pointopoint> -f <if-name-file> -S <socket-name>")
+    
+    parser = OptionParser(usage = usage)
+
+    parser.add_option("-t", "--vif-type", dest="vif_type",
+        help = "Virtual interface type. Either IFF_TAP or IFF_TUN. "
+            "Defaults to IFF_TAP. ", type="str")
+
+    parser.add_option("-a", "--ip4-address", dest="ip4_address",
+        help = "IPv4 address to assign to interface. It must belong to the "
+            "network segment owned by the slice, given by the vsys_vnet tag. ",
+        type="str")
+
+    parser.add_option("-n", "--net-prefix", dest="net_prefix",
+        help = "IPv4 network prefix for the interface. It must be the one "
+            "given by the slice's vsys_vnet tag. ",
+        type="int")
+
+    parser.add_option("-s", "--snat", dest="snat", default = False,
+        action="store_true", help="Enable SNAT for the interface")
+
+    parser.add_option("-p", "--pointopoint", dest="pointopoint",
+        help = "Peer end point for the interface  ", default = None,
+        type="str")
+
+    parser.add_option("-f", "--if-name-file", dest="if_name_file",
+        help = "File to store the interface name assigned by the OS", 
+        default = "if_name", type="str")
+
+    parser.add_option("-S", "--socket-name", dest="socket_name",
+        help = "Name for the unix socket used to interact with this process", 
+        default = "tap.sock", type="str")
+
+    (options, args) = parser.parse_args()
+    
+    vif_type = vsys.IFF_TAP
+    if options.vif_type and options.vif_type == "IFF_TUN":
+        vif_type = vsys.IFF_TUN
+
+    return (vif_type, options.ip4_address, options.net_prefix, options.snat,
+            options.pointopoint, options.if_name_file, options.socket_name)
+
+if __name__ == '__main__':
+
+    (vif_type, ip4_address, net_prefix, snat, pointopoint,
+            if_name_file, socket_name) = get_options()
+
+    (fd, if_name) = vsys.fd_tuntap(vif_type)
+    vsys.vif_up(if_name, ip4_address, net_prefix, snat, pointopoint)
+    
+    # Saving interface name to 'if_name_file
+    f = open(if_name_file, 'w')
+    f.write(if_name)
+    f.close()
+
+    # create unix socket to receive instructions
+    sock = create_socket(socket_name)
+    sock.listen(0)
+
+    # wait for messages to arrive and process them
+    stop = False
+
+    while not stop:
+        conn, addr = sock.accept()
+        conn.settimeout(5)
+
+        while not stop:
+            try:
+                msg = recv_msg(conn)
+            except socket.timeout, e:
+                # Ingore time-out
+                continue
+
+            if not msg:
+                # Ignore - connection lost
+                break
+
+            if msg == STOP_MSG:
+                stop = True
+                reply = stop_action()
+            else:
+                reply = reply_action(msg)
+
+            try:
+                send_reply(conn, reply)
+            except socket.error:
+                break
+