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|
#
# Copyright (c) 2005 XenSource Ltd.
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of version 2.1 of the GNU Lesser General Public
# License as published by the Free Software Foundation.
#
# This library 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
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; If not, see <http://www.gnu.org/licenses/>.
#
dir=$(dirname "$0")
. "$dir/xen-hotplug-common.sh"
. "$dir/xen-network-common.sh"
findCommand "$@"
if [ "$command" != "online" ] &&
[ "$command" != "offline" ] &&
[ "$command" != "add" ] &&
[ "$command" != "remove" ]
then
log err "Invalid command: $command"
exit 1
fi
# Parameters may be read from the environment, the command line arguments, and
# the store, with overriding in that order. The environment is given by the
# driver, the command line is given by the Xend global configuration, and
# store details are given by the per-domain or per-device configuration.
evalVariables "$@"
# Older versions of Xen do not pass in the type as an argument,
# so the default value is vif.
: ${type_if:=vif}
case "$type_if" in
vif)
dev=$vif
;;
tap)
dev=$INTERFACE
;;
*)
log err "unknown interface type $type_if"
exit 1
;;
esac
case "$command" in
online | offline)
test "$type_if" != vif && exit 0
;;
add | remove)
test "$type_if" != tap && exit 0
;;
esac
rename_vif() {
local dev=$1
local vifname=$2
# if a custom vifname was chosen and a link with that desired name
# already exists, then stop, before messing up whatever is using
# that interface (e.g. another running domU) because it's likely a
# configuration error
if ip link show "$vifname" >&/dev/null
then
fatal "Cannot rename interface $dev. An interface with name $vifname already exists."
fi
do_or_die ip link set "$dev" name "$vifname"
}
if [ "$type_if" = vif ]; then
# Check presence of compulsory args.
XENBUS_PATH="${XENBUS_PATH:?}"
dev="${dev:?}"
vifname=$(xenstore_read_default "$XENBUS_PATH/vifname" "")
if [ "$vifname" ]
then
if [ "$command" == "online" ]
then
rename_vif "$dev" "$vifname"
fi
dev="$vifname"
fi
elif [ "$type_if" = tap ]; then
# Check presence of compulsory args.
: ${INTERFACE:?}
# Get xenbus_path from device name.
# The name is built like that: "vif${domid}.${devid}-emu".
dev_=${dev#vif}
dev_=${dev_%-emu}
domid=${dev_%.*}
devid=${dev_#*.}
XENBUS_PATH="/local/domain/0/backend/vif/$domid/$devid"
vifname=$(xenstore_read_default "$XENBUS_PATH/vifname" "")
if [ "$vifname" ]
then
vifname="${vifname}-emu"
if [ "$command" == "add" ]
then
rename_vif "$dev" "$vifname"
fi
dev="$vifname"
fi
fi
ip=${ip:-}
ip=$(xenstore_read_default "$XENBUS_PATH/ip" "$ip")
IPTABLES_WAIT_RUNE="-w"
IPTABLES_WAIT_RUNE_CHECKED=false
# When iptables introduced locking, in the event of lock contention,
# they made "fail" rather than "wait for the lock" the default
# behavior. In order to select "wait for the lock" behavior, you have
# to add the '-w' parameter. Unfortunately, both the locking and the
# option were only introduced in 2013, and older versions of iptables
# will fail if the '-w' parameter is included (since they don't
# recognize it). So check to see if it's supported the first time we
# use it.
iptables_w()
{
if ! $IPTABLES_WAIT_RUNE_CHECKED ; then
iptables $IPTABLES_WAIT_RUNE -L -n >& /dev/null
if [[ $? == 0 ]] ; then
# If we succeed, then -w is supported; don't check again
IPTABLES_WAIT_RUNE_CHECKED=true
elif [[ $? == 2 ]] ; then
iptables -L -n >& /dev/null
if [[ $? != 2 ]] ; then
# If we fail with PARAMETER_PROBLEM (2) with -w and
# don't fail with PARAMETER_PROBLEM without it, then
# it's the -w option
IPTABLES_WAIT_RUNE_CHECKED=true
IPTABLES_WAIT_RUNE=""
fi
fi
fi
iptables $IPTABLES_WAIT_RUNE "$@"
}
frob_iptable()
{
if [ "$command" == "online" -o "$command" == "add" ]
then
local c="-I"
else
local c="-D"
fi
iptables_w "$c" FORWARD -m physdev --physdev-is-bridged --physdev-in "$dev" \
"$@" -j ACCEPT 2>/dev/null &&
iptables_w "$c" FORWARD -m physdev --physdev-is-bridged --physdev-out "$dev" \
-j ACCEPT 2>/dev/null
if [ \( "$command" == "online" -o "$command" == "add" \) -a $? -ne 0 ]
then
log err "iptables setup failed. This may affect guest networking."
fi
}
##
# Add or remove the appropriate entries in the iptables. With antispoofing
# turned on, we have to explicitly allow packets to the interface, regardless
# of the ip setting. If ip is set, then we additionally restrict the packets
# to those coming from the specified networks, though we allow DHCP requests
# as well.
#
handle_iptable()
{
# Check for a working iptables installation. Checking for the iptables
# binary is not sufficient, because the user may not have the appropriate
# modules installed. If iptables is not working, then there's no need to do
# anything with it, so we can just return.
if ! iptables_w -L -n >&/dev/null
then
return
fi
claim_lock "iptables"
if [ "$ip" != "" ]
then
local addr
for addr in $ip
do
frob_iptable -s "$addr"
done
# Always allow the domain to talk to a DHCP server.
frob_iptable -p udp --sport 68 --dport 67
else
# No IP addresses have been specified, so allow anything.
frob_iptable
fi
release_lock "iptables"
}
##
# ip_of interface
#
# Print the IP address currently in use at the given interface, or nothing if
# the interface is not up.
#
ip_of()
{
ip -4 -o addr show primary dev "$1" | awk '$3 == "inet" {split($4,i,"/"); print i[1]; exit}'
}
##
# dom0_ip
#
# Print the IP address of the interface in dom0 through which we are routing.
# This is the IP address on the interface specified as "netdev" as a parameter
# to these scripts, or eth0 by default. This function will call fatal if no
# such interface could be found.
#
dom0_ip()
{
local nd=${netdev:-eth0}
local result=$(ip_of "$nd")
if [ -z "$result" ]
then
fatal \
"$netdev is not up. Bring it up or specify another interface with " \
"netdev=<if> as a parameter to $0."
fi
echo "$result"
}
|
