RFC2131 paragraph 4.1 states DHCP messages broadcast by a client prior to
that client obtaining its IP address must have the source IP address
field in the header set to 0.
Request messages transmitted in renewing and rebinding state need to use
the obtained IP address as source IP address in the header; this behavior
lines up with other implementations like ISC dhcp client.
Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
While RFC1035 recommends a label not to start with a number, there is
actually no such limitation in dns. One may buy a domain name like
0x1.net and use it.
This commit remove this check and allow a user to use such domains.
Signed-off-by: Arthur Gautier <baloo@gandi.net>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Prevent nasty surprises if script runs longer than lease time / 2.
Signed-off-by: John Schroeder <jschroed@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Based on the following user report:
I ran into an issue where I was seeing a long delay in the scripts called
in udhcp_run_script. I was using an old version of OpenWrt (kamikaze)
and a satellite modem. An NTP script was being called and the modem
would sometimes take a long time to respond to the DNS lookup when
it was offline.
This delay started affecting my lease time. The lease that I would
get from my satellite modem before it was online would be short:
only 60 seconds. The delay with NTP and the modem would typically
be about 18 seconds. This would cause the first DHCP renew request
from dhcpc to be a little late. Under certain circumstances,
I could even see the first DHCP renew to occur after the lease
had expired!
function old new delta
udhcpc_main 2816 2837 +21
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Some clients have a very short timeout for sending the DHCP
DISCOVER, shorter than the arpping timeout of 2000 milliseconds
that udhcpd uses by default.
This patch allows tweaking the timeout, or disabling of arpping
altogether, at the risk of handing out addresses which are
already in use.
function old new delta
udhcpd_main 1460 1501 +41
udhcpc_main 2814 2851 +37
packed_usage 29957 29974 +17
arpping 477 493 +16
find_free_or_expired_nip 161 174 +13
send_offer 285 292 +7
nobody_responds_to_arp 85 89 +4
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 7/0 up/down: 135/0) Total: 135 bytes
Signed-off-by: Michel Stam <m.stam@fugro.nl>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Scenario:
1. udhcpc gets lease for 86400 secs and sleeps for 43200 before renew attempt
2. PC gets physically disconnected and connected to another network
3. some phy control software sends SIGUSR1 to renew the lease, SIGUSR2 isn't
used because newly connected network could be the same as before
4. udhcpc sends unicast renew requests until lease timeout fall to 60 sec.
They are ignored by new network dhcp servers
5. udhcpc sends broadcast rebind requests for 60 seconds, which are NAKed
or ignored too
6. udhcpc deconfigs and starting from discover state, gets new lease for the
new network
So, pt.4+5 it could take up to 86400 secs without correct lease, which is
too long and not acceptable.
Second SIGUSR1 will immediately run into deconfig/discover state, which is
not preferable in case of the same subnet replugged.
This patch makes sure after SIGUSR1 timeout is no more than -A NUM
(usually 20 sec). It means that renew will be requested via broadcast,
and if no replies come back, full deconf/reconf cycle will be initiated
in 20 seconds.
Signed-off-by: Vladislav Grishenko <themiron@mail.ru>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
In theory, sending secs set to constant zero should be ok too.
But some bleeping servers can actually be configured to answer ONLY
if secs is bigger than a preset value (!!)
http://developer.apple.com/library/mac/#documentation/Darwin/Reference/ManPages/man8/bootpd.8.html
grep for "reply_threshold_seconds"
function old new delta
udhcpc_main 2573 2623 +50
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
