On 03/10/13 14:05, Nehal J Wani wrote:
Yes. I just added contrib/mactable/macscript to the git repo, which is your
previous script slightly less elegantly modified by me for this
circumstance. I also put back the "make new file then atomically rename"
behaviour since that means anything using this file doesn't risk a race
condition leading to a half-written file.
I gave a try to the --dhcp-script option of dnsmasq. Following are the findings:
Script used: (a little modified version of
http://thekelleys.org.uk/gitweb/?p=dnsmasq.git;a=blob_plain;f=contrib/mactable/macscript;hb=HEAD):
#!/bin/bash
STATUS_FILE="/var/lib/libvirt/
dnsmasq/dnsmasq-ip-mac.status"
# Script for dnsmasq lease-change hook.
# Maintains the above file with a IP address/MAC address pairs,
# one lease per line. Works with IPv4 and IPv6 leases, file is
# atomically updated, so no races for users of the data.
action="$1"
mac="$2" # IPv4
ip="$3"
expirytime="$DNSMASQ_LEASE_EXPIRES"
hostname="$DNSMASQ_SUPPLIED_HOSTNAME"
clientid="$DNSMASQ_CLIENT_ID"
# ensure it always exists.
if [ ! -f "$STATUS_FILE" ]; then
touch "$STATUS_FILE"
fi
if [ -n "$DNSMASQ_IAID" ]; then
mac="$DNSMASQ_MAC" # IPv6
clientid="$2"
fi
# worry about an add or old action when the MAC address is not known:
# leave any old one in place in that case.
if [ "$action" = "add" -o "$action" = "old" -o "$action" = "del" ]; then
if [ -n "$mac" -o "$action" = "del" ]; then
sed "/^${ip//./\.} / d" "$STATUS_FILE"> "$STATUS_FILE".new
if [ "$action" = "add" -o "$action" = "old" ]; then
echo "$expirytime $mac $ip $hostname $clientid">> "$STATUS_FILE".new
fi
mv "$STATUS_FILE".new "$STATUS_FILE" # atomic update.
fi
fi
Changes made to libvirt code:
diff --git a/src/network/bridge_driver.c b/src/network/bridge_driver.c
index 8787bdb..7f9a74f 100644
--- a/src/network/bridge_driver.c
+++ b/src/network/bridge_driver.c
@@ -1058,6 +1058,7 @@
networkBuildDhcpDaemonCommandLine(virNetworkObjPtr network,
cmd = virCommandNew(dnsmasqCapsGetBinaryPath(caps));
virCommandAddArgFormat(cmd, "--conf-file=%s", configfile);
+ virCommandAddArgFormat(cmd, "--dhcp-script=%s",
"/var/lib/libvirt/dnsmasq/macscript.sh");
*cmdout = cmd;
ret = 0;
cleanup:
In dnsmasq version 2.65 (latest on f18 repos), useful variables that were set:
In the case of ipv4:
$1=add $2=52:54:00:95:41:5d $3=192.168.100.128
DNSMASQ_INTERFACE=virbr0
DNSMASQ_TAGS=virbr0
DNSMASQ_TIME_REMAINING=3600
DNSMASQ_LEASE_EXPIRES=1380745674
In the case of ipv6:
$1=add $2=00:01:00:01:19:df:2e:19:52:54:00:24:13:15 $3=2001:db8:ca2:2:1::45
DNSMASQ_INTERFACE=virbr3
DNSMASQ_TAGS=dhcpv6 virbr3
DNSMASQ_SERVER_DUID=00:01:00:01:19:df:29:7e:f0:4d:a2:8c:14:51
DNSMASQ_IAID=2364181
DNSMASQ_TIME_REMAINING=3600
DNSMASQ_LEASE_EXPIRES=1380745131
In the latest dnsmasq version 2.67rc2-3-g889d8a1 (built after cloning
from git://thekelleys.org.uk/dnsmasq.git), useful variables that were
set:
In the case of ipv4:
add 52:54:00:1a:a1:55 192.168.100.204
DNSMASQ_INTERFACE=virbr0
DNSMASQ_LEASE_EXPIRES=1380749702
DNSMASQ_TAGS=virbr0
DNSMASQ_TIME_REMAINING=3600
In the case of ipv6:
add 00:01:00:01:19:df:3a:8e:52:54:00:7d:49:25 2001:db8:ca2:2:1::f5
DNSMASQ_IAID=8210725
DNSMASQ_INTERFACE=virbr3
DNSMASQ_LEASE_EXPIRES=1380748320
DNSMASQ_MAC=52:54:00:7d:49:25
DNSMASQ_SERVER_DUID=
DNSMASQ_TAGS=dhcpv6 virbr3
DNSMASQ_TIME_REMAINING=3600
So, in case of latest dnsmasq code, output in dnsmasq-ip-mac.status:
1380747917 52:54:00:82:5e:09 2001:db8:ca2:2:1::79
1380747943 52:54:00:61:bd:d8 2001:db8:ca2:2:1::88
1380748110 52:54:00:15:1e:05 192.168.100.180
1380748320 52:54:00:7d:49:25 2001:db8:ca2:2:1::f5
00:01:00:01:19:df:3a:8e:52:54:00:7d:49:25
1380749702 52:54:00:1a:a1:55 192.168.100.204
1380749877 52:54:00:73:0a:27 192.168.100.190
1380749879 52:54:00:b7:87:3e 2001:db8:ca2:2:1::3e
00:01:00:01:19:df:40:a6:52:54:00:b7:87:3e
1380749880 52:54:00:bc:55:df 2001:db8:ca2:2:1::8f
00:01:00:01:19:df:40:a6:52:54:00:bc:55:df
1380749880 52:54:00:b7:87:3e 2001:db8:ca2:2:1::3e
00:01:00:01:19:df:40:a6:52:54:00:b7:87:3e
Apologies for the long message.
Queries:
(i) Why is DNSMASQ_SERVER_DUID blank in case of ipv6 (dnsmasq
2.67rc2-3-g889d8a1) ? Is it an issue with libvirt code or dnsmasq?
I don't know. It's working fine for me in a fairly standard dnsmasq
installation, which is some evidence that it's a libvirt thing, but not
strong evidence. On the other hand, the code that deals with that has
been touched, so the difference between 2.65 and the latest code is
suspicious. I'd be interested in any clues you can find about what's
going on.
(ii) When will be dnsmasq version 2.67rc2-3-g889d8a1 be out as tarball
and when will it be available in the fedora repositories? (I don't
know who maintains the package buildings, but a tentative date would
be fine)
You can get a tarball of any state of the git repository, including the
latest, from http://thekelleys.org.uk/gitweb/?p=dnsmasq.git;a=summary
The "snapshot" links on the right allow you to download tarballs.
dnsmasq-2.67 is in the process of release. I anticipate a final release
soon, probably later next week.
Cheers,
Simon.
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