Re: [Dnsmasq-discuss] Query: DNSMASQ_LEASE_EXPIRES
On Thu, Sep 22, 2016 at 3:21 PM, Nehal J Wani <nehaljw.k...@gmail.com> wrote: > Hi! > > According to the man page of dnsmasq, DNSMASQ_LEASE_EXPIRES stores the > time of lease expiry and DNSMASQ_TIME_REMAINING stores the number of > seconds until expiry and these are passed to the script specified to > the option --dhcp-script. > > Consider the scenario when the configuration has specified 'infinite' > as the value of for a particular dhcp-range. In this > case, the value of DNSMASQ_LEASE_EXPIRES is always 0 and > DNSMASQ_TIME_REMAINING is not even present. Is this an expected > behaviour? > > Another query: the value of lease-time is stored in an unsigned int > while parsing the options and it is different in struct script_data. > Is there a specific reason behind choosing different datatypes? > Ping! :-) -- Nehal J Wani ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
[Dnsmasq-discuss] Query: DNSMASQ_LEASE_EXPIRES
Hi! According to the man page of dnsmasq, DNSMASQ_LEASE_EXPIRES stores the time of lease expiry and DNSMASQ_TIME_REMAINING stores the number of seconds until expiry and these are passed to the script specified to the option --dhcp-script. Consider the scenario when the configuration has specified 'infinite' as the value of for a particular dhcp-range. In this case, the value of DNSMASQ_LEASE_EXPIRES is always 0 and DNSMASQ_TIME_REMAINING is not even present. Is this an expected behaviour? Another query: the value of lease-time is stored in an unsigned int while parsing the options and it is different in struct script_data. Is there a specific reason behind choosing different datatypes? Cheers! Nehal J Wani ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
Re: [Dnsmasq-discuss] Query regarding --leasefile-ro
That looks sensible. I guess from these questions that you're thinking about storing the lease database just in the custom format, and using --leasefile-ro Right now, libvirt stores all leases for each interface in separate files. That is, one lease database per dnsmasq instance, it does so, on the basis of the environment variable DNSMASQ_INTERFACE (I know that it is not set in case of del events everytime). The trouble is, when it gets the argument 'init', how will my helper program know which database it has to read and print to stdout? Suppose if we have only one lease database for all dnsmasq instances, how will the leases helper program distinguish between different interfaces (that is, for which interface should I print info, if I get 'init' as argument)? How does it happen by default, when none of --dhcp-script and --leasefile-ro are provided? Thanking You, Nehal J Wani ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
[Dnsmasq-discuss] Query regarding --leasefile-ro
Hi! The man page of dnsmasq (under the section -9, --leasefile-ro), states: When called like this the script should write the saved state of the lease database, in dnsmasq leasefile format, to stdout and exit with zero exit code. Q1. What is the purpose of printing to stdout? I guess it is for dnsmasq to know the information of previous leases, but I am not sure. Q2. What all information do I need to print in 'dnsmasq leasefile format' ? What is the exact format? Is there an example for this (like the example file macscript)? Q3. Apart from the leases, dnsmasq also prints some extra information like duid 00:01:00:01:1b:40:8d:94:00:25:64:8b:e4:2c in the lease file. Is this also mandatory to print to stdout in case I use leasefile-ro ? Thanking You, Nehal J Wani ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
[Dnsmasq-discuss] old event to dhcp-script on lease expiry
Hi! I am trying to understand whether an 'old' event is generated or not when a lease expires. To experiment this, I used Dnsmasq version 2.72test3-5-gcdb755c I launch dnsmasq like this: sudo /sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/default6.conf --dhcp-script=/tmp/script.sh Contents of script: #!/bin/bash echo $@ /tmp/out env /tmp/out echo /tmp/out Contents of default6.conf: strict-order pid-file=/var/run/libvirt/network/default6.pid except-interface=lo bind-dynamic interface=virbr3 dhcp-range=192.168.150.128,192.168.150.254,2m dhcp-no-override dhcp-range=2001:db8:ca2:2:1::10,2001:db8:ca2:2:1::ff,2m dhcp-leasefile=/var/lib/libvirt/dnsmasq/default6.leases dhcp-lease-max=367 dhcp-hostsfile=/var/lib/libvirt/dnsmasq/default6.hostsfile addn-hosts=/var/lib/libvirt/dnsmasq/default6.addnhosts enable-ra When I run 'service network restart' inside my guest machine, I see that the script is exec'ed with 'old' event. Now, I see that the lease file /var/lib/libvirt/dnsmasq/default6.leases keeps getting updated after every 2 minutes, since the lease expires, but the script /tmp/script.sh doesn't get invoked when the lease gets renewed. Is this expected? I don't see any 'old' event for the renewed lease. Regards, Nehal J Wani ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
Re: [Dnsmasq-discuss] old event to dhcp-script on lease expiry
An old event is not generated when a lease is _renewed_ (ie when the only thing that changes is the expiration time) unless the option leasefile-ro is set. Note that setting leasefile-ro has a bunch of other effects too. When a lease _expires_ (ie the end time of the lease is reached without it being renewed) then a a del event is generated. So, if I understand correctly, there is no way to maintain the leases file database *and* have my own script catch all events? Why does dnsmasq put such restrictions? It would be cool to have both concurrently. Another question, not very much related to dnsmasq, is that when a machine receives a lease for a particular period, when should it query the DHCP again for a new lease? Is it bound to do so, by some RFC? Or is a matter of choice by the developer? -- Nehal J Wani ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
Re: [Dnsmasq-discuss] old event to dhcp-script on lease expiry
On Sat, Jun 28, 2014 at 12:58 AM, Simon Kelley si...@thekelleys.org.uk wrote: On 27/06/14 19:40, Nehal J Wani wrote: An old event is not generated when a lease is _renewed_ (ie when the only thing that changes is the expiration time) unless the option leasefile-ro is set. Note that setting leasefile-ro has a bunch of other effects too. When a lease _expires_ (ie the end time of the lease is reached without it being renewed) then a a del event is generated. So, if I understand correctly, there is no way to maintain the leases file database *and* have my own script catch all events? Why does dnsmasq put such restrictions? That's correct. The reason for the behaviour is mainly historical. At first, the script received just the events needed to log the existance of leases. Later, the ability to use the script to maintain the lease database was added, and for that, changes to the expiration time had to be noted. THe old behaviour (when leasefile-ro is not set) stayed for backwards compatibility. It would be cool to have both concurrently. As a pragmatic approach, the patch to get the behaviour you want is very small. Recently, an API for querying leases info guest machines was pushed in libvirt and will most likely be available in 1.2.6. Since this library is used by many people around the world, and we have our custom lease file helper, which maintains a separate database for leases in JSON format, if we just enable leasefile-ro, then we will loose the lease file generated by dnsmasq, and we don't want that. Hence, sending a patch is fine by me, but will you be willing to have this option available in dnsmasq? Another question, not very much related to dnsmasq, is that when a machine receives a lease for a particular period, when should it query the DHCP again for a new lease? Is it bound to do so, by some RFC? Or is a matter of choice by the developer? The server can include the information in the lease. There are three options which it can include. The length of the lease is mandatory, and there are two options called T1 and T2. T1 is the time after which the client should renew the lease by doing unicast to the server which gave it the lease. T2 is the time after which the client should try broadcasting if it fails to renew the lease, to give the other half of a failover pair a chance to reply. T1 defaults to half of the lease time, and T2 to 7/8ths of the leasetime. In practise it's very rare to use other values for these. Dnsmasq always send T1 as half lease time and T2 as 7/8th the lease time. It doesn't allow them to be configured differently. The RFC the details this is RFC 2131. Thanks for all this info. Query1: If the lease time is say, 10 minutes, then T1 will be 5 minutes. Then according to the RFC, the machine should ask for a renewal of the lease from the DHCP server using the unicast method? In this case, no event will be generated? But you said that, The old behaviour (when leasefile-ro is not set) stayed for backwards compatibility. Query2: What does dnsmasq do if the machine sends no request for renewal at all? Will it just delete the lease? ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
[Dnsmasq-discuss] Reg: --dhcp-script option
Suppose I am using the script for dnsmasq lease-change hook ([dnsmasq.git] / contrib / mactable / macscript) and 3 leases have been handed out for a particular network. Now, if I shutdown the network and start dnsmasq again after these 3 leases have expired, the leases file has zero entries, but the /tmp/dnsmasq-ip-mac.status file will have those old entries. How will I clean them up? Will I have to manually check the timestamps and remove those entries or dnsmasq provides something that I am missing? -- Nehal J Wani ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
Re: [Dnsmasq-discuss] Reg: --dhcp-script option
Is the environment variable DNSMASQ_INTERFACE set when del action is called? If not, why? On 12/17/13, Simon Kelley si...@thekelleys.org.uk wrote: On 16/12/13 19:06, Nehal J Wani wrote: Suppose I am using the script for dnsmasq lease-change hook ([dnsmasq.git] / contrib / mactable / macscript) and 3 leases have been handed out for a particular network. Now, if I shutdown the network and start dnsmasq again after these 3 leases have expired, the leases file has zero entries, but the /tmp/dnsmasq-ip-mac.status file will have those old entries. How will I clean them up? Will I have to manually check the timestamps and remove those entries or dnsmasq provides something that I am missing? You'll see del events for the leases, either when they actually expire, or (if dnsmasq isn't running then) when dnsmasq is started again. Cheers, Simon. ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss -- Nehal J Wani ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
Re: [Dnsmasq-discuss] Reg: --dhcp-script option
On 12/17/13, Simon Kelley si...@thekelleys.org.uk wrote:
On 16/12/13 21:26, Nehal J Wani wrote:
Is the environment variable DNSMASQ_INTERFACE set when del action is
called? If not, why?
It _may_ be, if the interface associated with the lease is known. That
information is not stored in the lease file, so restarting dnsmasq will
lose the knowledge of the interface and DNSMASQ_INTERFACE will not be
set, unless there's an intervening event that provides the information.
So
restart dnsmasq
renew DHCP lease
DHCP lease expires
del event sent
will set DNSMASQ_INTERFACE
but
stop dnsmasq
wait whilst lease expires
start dnsmasq
dnsmasq notices that lease has expired and sends del event
won't.
This is also true of many of the other data supplied, eg
DNSMASQ_VENDOR_CLASS, DNSMASQ_SUPPLIED_HOSTNAME, DNSMASQ_CIRCUIT_ID
Cheers,
Simon.
On 12/17/13, Simon Kelley si...@thekelleys.org.uk wrote:
On 16/12/13 19:06, Nehal J Wani wrote:
Suppose I am using the script for dnsmasq lease-change hook
([dnsmasq.git] / contrib / mactable / macscript) and 3 leases have
been handed out for a particular network. Now, if I shutdown the
network and start dnsmasq again after these 3 leases have expired, the
leases file has zero entries, but the /tmp/dnsmasq-ip-mac.status
file will have those old entries. How will I clean them up? Will I
have to manually check the timestamps and remove those entries or
dnsmasq provides something that I am missing?
You'll see del events for the leases, either when they actually
expire, or (if dnsmasq isn't running then) when dnsmasq is started
again.
Cheers,
Simon.
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Actually, while developing the leases API for libvirt, I have to keep
separate custom-leases file for each network. (One active network is
mapped to one interface only) So, I thought, why not use the env
DNSMASQ_INTERFACE to differentiate? I have attached the source code of
script. The problem arises during:
restart dnsmasq
renew DHCP lease
DHCP lease expires
del event sent
Now, since the interface is not known, I'll have to compare IP address
in each file! Is there no way of knowing which file it should
correspond to?
I want to keep leases in different files to ease my task, so that once
a network is completely destroyed and undefined, its leases can also
be deleted easily (by just using unlink() on the desired file).
--
Nehal J Wani
/*
* leasehelper.c:
*
* Copyright (C) 2013-2014 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* 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/.
*
* Author: Nehal J Wani nehaljw.k...@gmail.com
*
*/
#include config.h
#include stdio.h
#include stdlib.h
#include virutil.h
#include virfile.h
#include virbuffer.h
#include virstring.h
#include virerror.h
#include viralloc.h
#include configmake.h
#define VIR_FROM_THIS VIR_FROM_NETWORK
/**
* VIR_NETWORK_DHCP_LEASE_FIELDS:
*
* Macro providing the maximum number of fields in an entry in
* the leases file
*/
#define VIR_NETWORK_DHCP_LEASE_FIELDS 6
/**
* VIR_NETWORK_DHCP_LEASE_FILE_SIZE_MAX:
*
* Macro providing the upper limit on the size of leases file
*/
#define VIR_NETWORK_DHCP_LEASE_FILE_SIZE_MAX 2097152
/*
* Use this when passing possibly-NULL strings to printf-a-likes.
*/
# define NULL_STR(s) ((s) ? (s) : *)
int
main(int argc, char **argv) {
/* Doesn't hurt to check */
if (argc 4)
return -1;
const char *action = argv[1];
const char *interface = NULL_STR(getenv(DNSMASQ_INTERFACE));
const char *expirytime = NULL_STR(getenv(DNSMASQ_LEASE_EXPIRES));
const char *mac = argv[2];
const char *ip = argv[3];
const char *iaid = NULL_STR(getenv(DNSMASQ_IAID));
const char *hostname = NULL_STR(getenv(DNSMASQ_SUPPLIED_HOSTNAME));
const char *clientid = NULL_STR(getenv(DNSMASQ_CLIENT_ID));
const char *leases_str = NULL;
char *lease_file = NULL;
char *lease_entries = NULL;
char *lease_entry = NULL;
char **lease_fields = NULL;
bool delete = false;
bool add = false;
int rv = -1;
int lease_file_len = 0;
FILE *fp = NULL;
virBuffer buf_new_lease = VIR_BUFFER_INITIALIZER;
virBuffer buf_all_leases = VIR_BUFFER_INITIALIZER;
if (virAsprintf
Re: [Dnsmasq-discuss] Reg: Info related to leases file
if [ -n $DNSMASQ_IAID ]; then mac=$DNSMASQ_MAC # IPv6 The existence of the environment variable DNSMASQ_MAC is not mentioned in the man page formed from the recent pull of dnsmaq code. It would be helpful if someone could add it :) -- Nehal J Wani ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
Re: [Dnsmasq-discuss] Reg: Info related to leases file
On Tue, Oct 22, 2013 at 11:44 PM, Simon Kelley si...@thekelleys.org.uk wrote: On 22/10/13 19:09, Nehal J Wani wrote: if [ -n $DNSMASQ_IAID ]; then mac=$DNSMASQ_MAC # IPv6 The existence of the environment variable DNSMASQ_MAC is not mentioned in the man page formed from the recent pull of dnsmaq code. It would be helpful if someone could add it :) The man page was updated in the checkin that added the feature. http://thekelleys.org.uk/gitweb/?p=dnsmasq.git;a=blobdiff;f=man/dnsmasq.8;h=e313d54fa86abf77ecbc3253d976bcae9b15997e;hp=05733b8da95cfc36c7c557005d850f7ef4aa607a;hb=89500e31f199e9ae1eadc86213b911ff44d30d6f;hpb=c8f2dd8b5363b9026ae3de6ce84b5b64df657892 Cheers, Simon. I am using Fedora 18 and after a successful make install, man dnsmasq reads from /usr/share/man/man8/dnsmasq.8.gz (the old version) whereas /usr/local/share/man/man8/dnsmasq.8 contains the latest version. Seems like removal of the old gziped file was required. -- Nehal J Wani ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
Re: [Dnsmasq-discuss] Reg: Info related to leases file
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?
(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)
--
Nehal J Wani
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Re: [Dnsmasq-discuss] Reg: Info related to leases file
Could you give an example of the DHCPv6 leases file with IPv4 as well as IPv6 addresses? Never Mind. I generated it myself. 1380008809 52:54:00:c3:73:d7 192.168.122.62 * * 1380007610 52:54:00:2a:47:ee 192.168.122.68 * * duid 00:01:00:01:19:d3:ec:62:f0:4d:a2:8c:14:51 1380008810 12809175 2001:db8:ca2:2:1::67 * 00:01:00:01:19:d3:f1:da:52:54:00:c3:73:d7 1380007610 2770926 2001:db8:ca2:2:1::3e * 00:01:00:01:19:d3:ed:2a:52:54:00:2a:47:ee Thanks for the info. -- Nehal J Wani UG3, BTech CS+MS(CL) IIIT-Hyderabad http://commandlinewani.blogspot.com -- Nehal J Wani ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
Re: [Dnsmasq-discuss] Reg: Info related to leases file
On Tue, Sep 24, 2013 at 1:15 AM, Simon Kelley si...@thekelleys.org.uk wrote: On 23/09/13 19:12, Nehal J Wani wrote: If I am not wrong, there are 5 fields in a dnsmasq/network-name.leases file: (i) Expiry time (ii) MAC Address (iii) IP Address (iv) Hostname (v) Client ID Q1: Is the above order fixed? Q2: Which values from above can be NULL? (I know that leases contains '*' for fields whose values are not known, but is it safe to assume that it will be '*' for any value that is unknown?) A1: Yes. A2: There will always be an expiry time and an IP address. The hostname and the client-id can be missing, in which case the fields will contain *. The Mac address may have a hardware type (rfc1060) appended like so: 02-01:02:03:04:05:06 If the hardware type is 01 (ethernet), then it's omitted For IEEE1394 clients, the hardware type is 24, and the length of the MAC address is zero, so this appears as 24- See rfc2855 for details. There's also I completely different format for DHCPv6. If DHCPv6 is in use then the IPv4 leases will be terminated with a line like this: duid server DUID as colon-separated hex and then there will follow the DHCPv6 leases as 1) Expiry time 2) IAID 3) IPv6 address 4) hostname 5) client DUID In case of DHCPv6, which of the above 5 fields can be missing (for IPv6 addresses)? Cheers, Simon. ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss -- Nehal J Wani UG3, BTech CS+MS(CL) IIIT-Hyderabad http://commandlinewani.blogspot.com ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
Re: [Dnsmasq-discuss] Reg: Info related to leases file
On Tue, Sep 24, 2013 at 3:37 PM, Simon Kelley si...@thekelleys.org.uk wrote: On 24/09/13 10:48, Nehal J Wani wrote: On Tue, Sep 24, 2013 at 1:15 AM, Simon Kelleysi...@thekelleys.org.uk wrote: On 23/09/13 19:12, Nehal J Wani wrote: If I am not wrong, there are 5 fields in a dnsmasq/network-name.leases file: (i) Expiry time (ii) MAC Address (iii) IP Address (iv) Hostname (v) Client ID Q1: Is the above order fixed? Q2: Which values from above can be NULL? (I know that leases contains '*' for fields whose values are not known, but is it safe to assume that it will be '*' for any value that is unknown?) A1: Yes. A2: There will always be an expiry time and an IP address. The hostname and the client-id can be missing, in which case the fields will contain *. The Mac address may have a hardware type (rfc1060) appended like so: 02-01:02:03:04:05:06 If the hardware type is 01 (ethernet), then it's omitted For IEEE1394 clients, the hardware type is 24, and the length of the MAC address is zero, so this appears as 24- See rfc2855 for details. There's also I completely different format for DHCPv6. If DHCPv6 is in use then the IPv4 leases will be terminated with a line like this: duidserver DUID as colon-separated hex and then there will follow the DHCPv6 leases as 1) Expiry time 2) IAID 3) IPv6 address 4) hostname 5) client DUID In case of DHCPv6, which of the above 5 fields can be missing (for IPv6 addresses)? Only the hostname, which can be replaced with * if no hostname is known. All the others are required. For both IPv4 and IPv6 leases, the expiry time can be zero which means never. Out of the three types: DUID-LLT, DUID-EN and DUID-LL, which one is used by dnsmasq? I am asking because I want to confirm whether the MAC address of the network interface is always a substring of the client DUID or not. Cheers, Simon. Cheers, Simon. ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss -- Nehal J Wani UG3, BTech CS+MS(CL) IIIT-Hyderabad http://commandlinewani.blogspot.com ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
[Dnsmasq-discuss] Reg: Info related to leases file
If I am not wrong, there are 5 fields in a dnsmasq/network-name.leases file: (i) Expiry time (ii) MAC Address (iii) IP Address (iv) Hostname (v) Client ID Q1: Is the above order fixed? Q2: Which values from above can be NULL? (I know that leases contains '*' for fields whose values are not known, but is it safe to assume that it will be '*' for any value that is unknown?) -- Nehal J Wani UG3, BTech CS+MS(CL) IIIT-Hyderabad http://commandlinewani.blogspot.com ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
Re: [Dnsmasq-discuss] Reg: Info related to leases file
On Tue, Sep 24, 2013 at 1:15 AM, Simon Kelley si...@thekelleys.org.uk wrote: On 23/09/13 19:12, Nehal J Wani wrote: If I am not wrong, there are 5 fields in a dnsmasq/network-name.leases file: (i) Expiry time (ii) MAC Address (iii) IP Address (iv) Hostname (v) Client ID Q1: Is the above order fixed? Q2: Which values from above can be NULL? (I know that leases contains '*' for fields whose values are not known, but is it safe to assume that it will be '*' for any value that is unknown?) A1: Yes. A2: There will always be an expiry time and an IP address. The hostname and the client-id can be missing, in which case the fields will contain *. The Mac address may have a hardware type (rfc1060) appended like so: 02-01:02:03:04:05:06 If the hardware type is 01 (ethernet), then it's omitted For IEEE1394 clients, the hardware type is 24, and the length of the MAC address is zero, so this appears as 24- See rfc2855 for details. There's also I completely different format for DHCPv6. If DHCPv6 is in use then the IPv4 leases will be terminated with a line like this: duid server DUID as colon-separated hex and then there will follow the DHCPv6 leases as 1) Expiry time 2) IAID 3) IPv6 address 4) hostname 5) client DUID Could you give an example of the DHCPv6 leases file with IPv4 as well as IPv6 addresses? Cheers, Simon. ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss -- Nehal J Wani UG3, BTech CS+MS(CL) IIIT-Hyderabad http://commandlinewani.blogspot.com ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
[Dnsmasq-discuss] Fwd: Reg: Max Length if an entry
I am implementing a public API in libvirt as part of my GSoC project, for which I need to parse the dnsmasq/network-name.leases file. I would like to know the maximum length that an entry can have in the leases file. Thanking You, Nehal J. Wani UG3, BTech CS+MS(CL) IIIT-Hyderabad http://commandlinewani.blogspot.com ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
