From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michael Tremer To: development@lists.ipfire.org Subject: Re: [PATCH] Add column with resolved hostname by IP address Date: Tue, 28 Nov 2023 10:40:04 +0000 Message-ID: <9679886A-0459-4561-AF0A-106B330D7532@ipfire.org> In-Reply-To: <98bd316a-0c32-4fb1-817e-27a2e9dd6dba@gmail.com> MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="===============8236599522220536630==" List-Id: --===============8236599522220536630== Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Hello, > On 28 Nov 2023, at 06:33, S=C3=A9bastien GISLAIN wrote: >=20 > Hi, >=20 > I understand your reluctance for this development. >=20 > On the one hand, the resolution only concerns local hosts. It is not guaranteed that any DNS lookups will only happen locally, but indee= d rather likely. > On the other hand, in my personal IPFire, with a Class C subnet on green ne= twork, I have 156 fixed leases and I don't see any slowdown. >=20 > Do you know of any IPFire deployments with class B or A subnets? We have lots of users that have a couple of thousand clients behind the firew= all, a couple of hundreds isn=E2=80=99t really that rare. > Additionally, searching into the local hosts file requires more complex dev= elopment... Not the hosts file=E2=80=A6 The DHCP leases file. That is being parsed furthe= r down showing a long table. It contains hostnames that the clients have subm= itted and you could match them by their MAC/IP address. That way, you only pa= rse one file and you get the hostname that the client thinks it has. > Have a nice day, > S=C3=A9bastien >=20 > P.S. Especially since I had prepared an update on the firewall log page = (firewalllog.dat) which was even slower than that of the DHCP server page (dh= cp.cgi)! 8'-( What would that do? >=20 > Je comprends ta r=C3=A9ticence pour cette =C3=A9volution. > D'une part, la r=C3=A9solution ne porte que sur des h=C3=B4tes locaux. > D'autre part, dans mon IPFire personnel, avec un sous-r=C3=A9seau de classe= C, j'ai 156 baux fixes et je ne constate pas de ralentissement. > Connais-tu des d=C3=A9ploiements d'IPFire avec des sous-r=C3=A9seaux de cla= sse B ou A ? >=20 > Le 24/11/2023 =C3=A0 14:34, Michael Tremer a =C3=A9crit : >> Hello Sebastien, >>=20 >> Thank you very much for submitting this patch. However, I do have some con= cerns about this being merged. >>=20 >> If you only have a couple of leases, everything is fine, but there are peo= ple who have hundreds of DHCP clients on their network, and it has been repor= ted before that this page is loading extremely slow. Adding a DNS request to = this will probably make loading the page many times slower than it already is. >>=20 >> And to consider the performance hit, I do not quite know what the benefit = is of showing this. Should we not rather parse the DHCP leases file and show = the hostname that the client has submitted? That would show the same result, = but it would be a lot faster. >>=20 >> -Michael >>=20 >>=20 >>> On 9 Nov 2023, at 21:36, Sebastien GISLAIN = wrote: >>>=20 >>> --- >>> html/cgi-bin/dhcp.cgi | 7 +++++++ >>> 1 file changed, 7 insertions(+) >>>=20 >>> diff --git a/html/cgi-bin/dhcp.cgi b/html/cgi-bin/dhcp.cgi >>> index f45703f0b..aabf565d7 100755 >>> --- a/html/cgi-bin/dhcp.cgi >>> +++ b/html/cgi-bin/dhcp.cgi >>> @@ -21,6 +21,7 @@ >>>=20 >>> use strict; >>> use experimental 'smartmatch'; >>> +use IO::Socket; >>>=20 >>> # enable only the following on debugging purpose >>> #use warnings; >>> @@ -1009,6 +1010,7 @@ print <>> >>> $Lang::tr{'mac address'} >>> $Lang::tr{'ip address'} >>> + $Lang::tr{'hostname'} >>> $Lang::tr{'remark'} >>> next-server<= /th> >>> filename >>> @@ -1106,9 +1108,14 @@ foreach my $line (@current2) { >>> $TAG4 =3D "class=3D'red'" if ($dhcpsettings{'KEY2'} ne $key); >>> } >>>=20 >>> + # resolved name (if exists) >>> + my $iaddr =3D inet_aton($temp[1]); >>> + my $rname =3D gethostbyaddr($iaddr, AF_INET); >>> + if (!$rname || $rname eq "") { $rname =3D $Lang::tr{'lookup failed'}; } >>> print <>> $TAG2$temp[0]$TAG3 >>> $TAG0$temp[1]$TAG1 >>> +$rname  >>> $temp[6]  >>> $temp[3]  >>> $temp[4]  >>> --=20 >>> 2.39.2 >>>=20 >>>=20 >>=20 >=20 --===============8236599522220536630==--