pfSense

It seems that dnsmasq keeps all of these internally.

If we rewrite this with a daemon or cron script of some kind, it would probably have to add these to /etc/hosts without clobbering the existing entries which are kept there. The DHCP lines could probably be tagged with a comment like so:

192.168.1.52 mypc.example.com mypc #DHCP Lease Host "mypc" 

When the hosts file is built in the PHP code, these lines could be stripped out and then a function called at the end to parse the leases file and add them back in. The new program could then just append to the end of the file.

Sound reasonable? I can start tinkering with a parser if there are no objections.

Sounds good to me.

PS: I don't think anything else writes to /etc/hosts except dnsmasq.

system_hosts_generate() generates the /etc/hosts entries for dnsmasq. so it does look like we will need the code to be able to determine if an entry is for dnsmasq or not. #DHCP Lease Host "mypc" would be good.

Wrote this shell script: http://cvs.pfsense.org/~sullrich/rc.parse-isc-dhcpd

Please review.

All code commited. This appears to work but I am concerned that the shell script forks so it doubles the ram usage to about 3 megabytes. need to investigate using lua or some other language that uses less memory (c?).

After having left pfsense running for a while my dynamic hostname resolution seems to have vanished.

1. uptime
   11:58PM up 27 days, 10:54, 2 users, load averages: 0.08, 0.02, 0.01

The following are all static hosts:

1. cat /etc/hosts
   127.0.0.1 localhost localhost.adamsnet
   192.168.0.1 pfsense.adamsnet pfsense
   129.137.4.127 pohl.adamsnet pohl
   192.168.0.245 macbox.adamsnet macbox
   192.168.0.2 downstairs.adamsnet downstairs
   192.168.0.60 nasbox.adamsnet nasbox
   192.168.0.96 G4box.adamsnet G4box
   192.168.0.116 brynns.adamsnet brynns
   192.168.0.119 freebsdbox.adamsnet freebsdbox
   192.168.0.121 mythtvbox.adamsnet mythtvbox
   192.168.0.124 BRN001BA9151890.adamsnet BRN001BA9151890

As you can see there are plenty of dynamic hosts:

1. cat /var/dhcpd/var/db/dhcpd.leases
2. All times in this file are in UTC (GMT), not your local timezone. This is
3. not a bug, so please don't ask about it. There is no portable way to
4. store leases in the local timezone, so please don't request this as a
5. feature. If this is inconvenient or confusing to you, we sincerely
6. apologize. Seriously, though - don't ask.
7. The format of this file is documented in the dhcpd.leases(5) manual page.
8. This lease file was written by isc-dhcp-V3.0.7

lease 192.168.1.25 {
starts 6 2010/06/26 22:07:28;
ends 0 2010/06/27 00:07:28;
tstp 0 2010/06/27 00:07:28;
binding state free;
hardware ethernet c4:17:fe:a4:3e:92;
uid "\001\304\027\376\244>\222";
}
lease 192.168.1.21 {
starts 0 2010/07/04 01:07:53;
ends 0 2010/07/04 03:07:53;
tstp 0 2010/07/04 03:07:53;
binding state free;
hardware ethernet 00:22:5f:c8:f6:20;
uid "\001\000\"_\310\366 ";
}
lease 192.168.1.23 {
starts 0 2010/07/04 02:11:56;
ends 0 2010/07/04 04:11:56;
binding state active;
next binding state free;
hardware ethernet 00:01:02:c9:3a:76;
uid "\001\000\001\002\311:v";
client-hostname "wap1";
}
lease 192.168.1.19 {
starts 0 2010/07/04 02:14:33;
ends 0 2010/07/04 04:14:33;
binding state active;
next binding state free;
hardware ethernet 00:1f:3c:c1:bf:28;
uid "\001\000\037<\301\277(";
client-hostname "zephyr";
}
lease 192.168.1.22 {
starts 0 2010/07/04 03:07:54;
ends 0 2010/07/04 05:07:54;
binding state active;
next binding state free;
hardware ethernet 00:50:da:b9:7e:b6;
uid "\001\000P\332\271~\266";
client-hostname "wap2";
}
lease 192.168.0.244 {
starts 0 2010/02/14 20:17:42;
ends 0 2010/02/14 20:57:07;
tstp 0 2010/02/14 20:57:07;
binding state free;
hardware ethernet 00:1b:21:19:ec:63;
uid "\001\000\033!\031\354c";
}
lease 192.168.0.41 {
starts 6 2010/02/20 04:50:56;
ends 6 2010/02/20 04:56:11;
tstp 6 2010/02/20 04:56:11;
binding state free;
hardware ethernet 00:0c:29:87:40:fc;
}
lease 192.168.0.243 {
starts 3 2010/02/24 20:22:02;
ends 3 2010/02/24 21:11:15;
tstp 3 2010/02/24 21:11:15;
binding state free;
hardware ethernet 00:1b:21:19:ec:63;
}
lease 192.168.0.240 {
starts 3 2010/02/24 21:25:07;
ends 3 2010/02/24 23:25:07;
tstp 3 2010/02/24 23:25:07;
binding state free;
hardware ethernet 08:00:27:54:7e:f8;
}
lease 192.168.0.238 {
starts 0 2010/03/14 19:42:05;
ends 0 2010/03/14 21:42:05;
tstp 0 2010/03/14 21:42:05;
binding state free;
hardware ethernet 08:00:27:ec:4f:9e;
}
lease 192.168.0.75 {
starts 3 2010/03/17 16:10:27;
ends 3 2010/03/17 18:10:27;
tstp 3 2010/03/17 18:10:27;
binding state free;
hardware ethernet 00:0c:29:79:87:5b;
uid "\001\000\014)y\207[";
}
lease 192.168.0.235 {
starts 1 2010/03/22 03:38:58;
ends 1 2010/03/22 05:38:58;
tstp 1 2010/03/22 05:38:58;
binding state free;
hardware ethernet 00:0c:29:55:52:0e;
}
lease 192.168.0.234 {
starts 1 2010/03/22 03:40:23;
ends 1 2010/03/22 05:40:23;
tstp 1 2010/03/22 05:40:23;
binding state free;
hardware ethernet 08:00:27:81:b6:d8;
}
lease 192.168.0.242 {
starts 5 2010/04/30 04:33:41;
ends 5 2010/04/30 06:33:41;
tstp 5 2010/04/30 06:33:41;
binding state free;
hardware ethernet 00:24:21:61:b3:3d;
uid "\001\000$!a\263=";
}
lease 192.168.0.241 {
starts 5 2010/05/28 21:27:45;
ends 6 2010/05/29 21:27:45;
tstp 6 2010/05/29 21:27:45;
binding state free;
hardware ethernet 08:00:27:0c:9e:0d;
}
lease 192.168.0.233 {
starts 5 2010/06/04 22:03:02;
ends 6 2010/06/05 00:03:02;
tstp 6 2010/06/05 00:03:02;
binding state free;
hardware ethernet 00:0c:29:c9:68:26;
uid "\001\000\014)\311h&";
}
lease 192.168.0.230 {
starts 2 2010/06/15 22:17:47;
ends 3 2010/06/16 00:17:47;
tstp 3 2010/06/16 00:17:47;
binding state free;
hardware ethernet 00:24:1d:20:64:12;
}
lease 192.168.0.237 {
starts 1 2010/06/21 21:51:50;
ends 1 2010/06/21 21:53:50;
tstp 1 2010/06/21 21:53:50;
binding state free;
hardware ethernet e1:6c:d6:ae:52:90;
uid "\001\341l\326\256R\220";
}
lease 192.168.0.236 {
starts 1 2010/06/21 21:51:51;
ends 1 2010/06/21 21:53:51;
tstp 1 2010/06/21 21:53:51;
binding state free;
hardware ethernet e9:eb:b3:a6:db:3c;
uid "\001\351\353\263\246\333<";
}
lease 192.168.0.15 {
starts 4 2010/06/24 01:22:30;
ends 4 2010/06/24 03:22:30;
tstp 4 2010/06/24 03:22:30;
binding state free;
hardware ethernet 00:0c:29:ad:ad:eb;
}
lease 192.168.0.231 {
starts 5 2010/06/25 21:53:01;
ends 5 2010/06/25 23:53:01;
tstp 5 2010/06/25 23:53:01;
binding state free;
hardware ethernet 00:24:1d:20:64:12;
uid "\001\000$\035 d\022";
}
lease 192.168.0.232 {
starts 6 2010/07/03 20:45:41;
ends 6 2010/07/03 22:45:41;
tstp 6 2010/07/03 22:45:41;
binding state free;
hardware ethernet 00:1f:d0:81:7e:37;
uid "\001\000\037\320\201~7";
}
lease 192.168.0.93 {
starts 0 2010/07/04 02:32:44;
ends 0 2010/07/04 04:32:44;
binding state active;
next binding state free;
hardware ethernet 00:11:24:d6:92:d8;
client-hostname "powerbook";
}
lease 192.168.0.239 {
starts 0 2010/07/04 02:55:13;
ends 0 2010/07/04 04:55:13;
binding state active;
next binding state free;
hardware ethernet 00:1b:21:19:ec:63;
client-hostname "mythbox3";
}
lease 192.168.0.82 {
starts 0 2010/07/04 03:10:12;
ends 0 2010/07/04 05:10:12;
binding state active;
next binding state free;
hardware ethernet 00:e0:b8:38:ad:8e;
uid "\001\000\340\2708\255\216";
client-hostname "bsdtop";
}
lease 192.168.1.23 {
starts 0 2010/07/04 03:11:56;
ends 0 2010/07/04 05:11:56;
binding state active;
next binding state free;
hardware ethernet 00:01:02:c9:3a:76;
uid "\001\000\001\002\311:v";
client-hostname "wap1";
}
lease 192.168.1.19 {
starts 0 2010/07/04 03:14:33;
ends 0 2010/07/04 05:14:33;
binding state active;
next binding state free;
hardware ethernet 00:1f:3c:c1:bf:28;
uid "\001\000\037<\301\277(";
client-hostname "zephyr";
}
lease 192.168.0.93 {
starts 0 2010/07/04 03:32:44;
ends 0 2010/07/04 05:32:44;
binding state active;
next binding state free;
hardware ethernet 00:11:24:d6:92:d8;
client-hostname "powerbook";
}
lease 192.168.0.239 {
starts 0 2010/07/04 03:55:13;
ends 0 2010/07/04 05:55:13;
binding state active;
next binding state free;
hardware ethernet 00:1b:21:19:ec:63;
client-hostname "mythbox3";
}

Here is the process still being displayed in ps:
root 4356 0.0 0.1 3316 1060 ?? Is 6Jun10 0:00.02 /usr/local/sbin/dhcpleases -l /var/dhcpd/var/db/dhcpd.leases -d adamsnet -p /var/run/dnsmasq.p

Sadly I think we may need to reopen this problem for feedback :(.