Paul Sutor
2019-Jul-17 21:51 UTC
[Pkg-xen-devel] Bug#932338: xen-utils-common: vif-nat fails to find backend/vif/x/x/domain
Package: xen-utils-common
Version: 4.11.1+92-g6c33308a8d-2
Severity: normal
Dear Maintainer,
This started when I upgraded from Debian 9 (Xen 4.8, Kernel 4.9) to Debian 10
(Xen 4.11, Kernel 4.19).
It still occurred after attempting a boot with the old Xen 4.8/Kernel 4.9.
Line 88 of vif-nat attempts to assign a "hostname" variable using
xenstore_read.
This key "backend/vif/x/x/domain" does not exist in xenstore, so the
script errors out, aborting the domU creation.
Upon further inspection, this "hostname" is only used when DHCP is
enabled, so I commented out line 88 for my personal use.
The script still errored after that, but I believe that is a separate issue and
I am submitting a separate bug for it.
I believe I even saw these "unable to read backend/vif/x/x/domain"
messages on the console while shutting down the dom0 for the first reboot after
installing Debian 10.
I looked into various things that might cause access restrictions, but it seems
the real cause is just that key "backend/vif/x/x/domain" not existing
(I don't know what's supposed to put those keys into that part of the
xenstore), and the script trying to read it.
Thanks for your attention,
Paul
-- System Information:
Debian Release: 10.0
APT prefers stable
APT policy: (500, 'stable')
Architecture: amd64 (x86_64)
Kernel: Linux 4.19.0-5-amd64 (SMP w/32 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8),
LANGUAGE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled
Versions of packages xen-utils-common depends on:
ii libc6 2.28-10
ii libxenstore3.0 4.11.1+92-g6c33308a8d-2
ii lsb-base 10.2019051400
ii python 2.7.16-1
ii ucf 3.0038+nmu1
ii udev 241-5
ii xenstore-utils 4.11.1+92-g6c33308a8d-2
xen-utils-common recommends no packages.
Versions of packages xen-utils-common suggests:
pn xen-doc <none>
-- Configuration Files:
/etc/default/xendomains changed:
XENDOMAINS_RESTORE=false
XENDOMAINS_AUTO=/etc/xen/auto
XENDOMAINS_STOP_MAXWAIT=300
/etc/xen/scripts/vif-nat changed:
dir=$(dirname "$0")
. "$dir/vif-common.sh"
if [ -f /etc/dhcpd.conf ]
then
dhcp=${dhcp:-yes}
else
dhcp=${dhcp:-no}
fi
if [ "$dhcp" != 'no' ]
then
dhcpd_conf_file=$(find_dhcpd_conf_file)
dhcpd_init_file=$(find_dhcpd_init_file)
dhcpd_arg_file=$(find_dhcpd_arg_file)
if [ -z "$dhcpd_conf_file" ] || [ -z "$dhcpd_init_file" ]
|| [ -z "$dhcpd_arg_file" ]
then
echo 'Failed to find dhcpd configuration or init or args file.'
>&2
exit 1
fi
fi
domid=$(xenstore_read "$XENBUS_PATH/frontend-id")
vifid=$(xenstore_read "$XENBUS_PATH/handle")
vifid=$(( $vifid + 1 ))
ip_from_dom()
{
local domid1=$(( $domid / 256 ))
local domid2=$(( $domid % 256 ))
echo "10.$domid1.$domid2.$vifid/16"
}
routing_ip()
{
echo $(echo $1 | awk -F. '{print
$1"."$2"."$3"."$4 + 127}')
}
dotted_quad()
{
echo\
$(( ($1 & 0xFF000000) >> 24))\
.$(( ($1 & 0x00FF0000) >> 16))\
.$(( ($1 & 0x0000FF00) >> 8 ))\
.$(( $1 & 0x000000FF ))
}
if [ "$ip" = "" ]
then
ip=$(ip_from_dom)
fi
router_ip=$(routing_ip "$ip")
vif_ip=`echo ${ip} | awk -F/ '{print $1}'`
if [ "$vifid" != "1" ]
then
hostname="$hostname-$vifid"
fi
dhcparg_remove_entry()
{
local tmpfile=$(mktemp)
sed -e "s/${dev} //" "$dhcpd_arg_file"
>"$tmpfile"
if diff "$tmpfile" "$dhcpd_arg_file" >/dev/null
then
rm "$tmpfile"
else
mv "$tmpfile" "$dhcpd_arg_file"
fi
}
dhcparg_add_entry()
{
dhcparg_remove_entry
local tmpfile=$(mktemp)
# handle Red Hat, SUSE, and Debian styles, with or without quotes
sed -e
's/^DHCPDARGS="*\([^"]*\)"*/DHCPDARGS="\1'"${dev}
"'"/' \
"$dhcpd_arg_file" >"$tmpfile" && mv
"$tmpfile" "$dhcpd_arg_file"
sed -e
's/^DHCPD_INTERFACE="*\([^"]*\)"*/DHCPD_INTERFACE="\1'"${dev}
"'"/' \
"$dhcpd_arg_file" >"$tmpfile" && mv
"$tmpfile" "$dhcpd_arg_file"
sed -e
's/^INTERFACES="*\([^"]*\)"*/INTERFACES="\1'"${dev}
"'"/' \
"$dhcpd_arg_file" >"$tmpfile" && mv
"$tmpfile" "$dhcpd_arg_file"
rm -f "$tmpfile"
}
dhcp_remove_entry()
{
local tmpfile=$(mktemp)
grep -v "host $hostname" "$dhcpd_conf_file"
>"$tmpfile"
if diff "$tmpfile" "$dhcpd_conf_file" >/dev/null
then
rm "$tmpfile"
else
mv "$tmpfile" "$dhcpd_conf_file"
fi
dhcparg_remove_entry
}
dhcp_up()
{
claim_lock "vif-nat-dhcp"
dhcp_remove_entry
mac=$(xenstore_read "$XENBUS_PATH/mac")
echo >>"$dhcpd_conf_file" \
"host $hostname { hardware ethernet $mac; fixed-address $vif_ip; option
routers $router_ip; option host-name \"$hostname\"; }"
dhcparg_add_entry
release_lock "vif-nat-dhcp"
"$dhcpd_init_file" restart || true
}
dhcp_down()
{
claim_lock "vif-nat-dhcp"
dhcp_remove_entry
release_lock "vif-nat-dhcp"
"$dhcpd_init_file" restart || true # We need to ignore failure
because
# ISC dhcpd 3 borks if there is nothing
# for it to do, which is the case if
# the outgoing interface is not
# configured to offer leases and there
# are no vifs.
}
case "$command" in
online)
if ip route | grep -q "dev ${dev}"
then
log debug "${dev} already up"
exit 0
fi
do_or_die ip link set dev "${dev}" up arp on
do_or_die ip addr add "$router_ip" dev "${dev}"
do_or_die ip route add "$vif_ip" dev "${dev}" src
"$router_ip"
echo 1 >/proc/sys/net/ipv4/conf/${dev}/proxy_arp
[ "$dhcp" != 'no' ] && dhcp_up
;;
offline)
[ "$dhcp" != 'no' ] && dhcp_down
do_without_error ifconfig "${dev}" down
;;
esac
echo hi
handle_iptable
call_hooks vif post
log debug "Successful vif-nat $command for ${dev}."
if [ "$command" = "online" ]
then
success
fi
/etc/xen/xend-config.sxp changed:
(dom0-min-mem 640)
(enable-dom0-ballooning yes)
(total_available_memory 0)
(dom0-cpus 0)
(vncpasswd '')
/etc/xen/xl.conf changed:
vif.default.script="vif-nat"
-- no debconf information