Hi,
I've noticed udhcpc was not attempting to renew the address in time,
in case the server offered
only 30s lease time. The reason ended up being the "--script" which I
use to install the address.
It was still getting the 30s value, whereas udhcpc internally corrects
the 30s value into 122s.
Please see the proposed patch below.
Best regards
Karel
Fixes DHCP lease time passed from udhcpc into the "--script"
For unusually short leases, udhcpc enforces a minimum lease time to avoid
excessive network traffic.
The original, unadjusted value, was however still being passed to the dhcp
event script, which was making it install the obtained IP address with a
lifetime shorter than the udhcpc's renewal period. As a result, the address
aged out and was removed without udhcpc attempting a renewal for some time.
This patch writes the corrected value back to the packet variable, from which
the script's environment is populated.
Signed-off-by: Karel Dolezal <karel.dole...@ui.com>
--- a/networking/udhcp/dhcpc.c 2020-07-10 11:11:43.229706806 +0200
+++ b/networking/udhcp/dhcpc.c 2020-07-10 11:17:30.366254882 +0200
@@ -1867,16 +1867,21 @@ int udhcpc_main(int argc UNUSED_PARAM, c
lease_seconds = 60 * 60;
} else {
/* it IS unaligned sometimes, don't
"optimize" */
move_from_unaligned32(lease_seconds,
temp);
lease_seconds = ntohl(lease_seconds);
/* paranoia: must not be too small and
not prone to overflows */
/* timeout > 60 - ensures at least one
unicast renew attempt */
- if (lease_seconds < 2 * 61)
+ if (lease_seconds < 2 * 61) {
lease_seconds = 2 * 61;
+ /* The --script reads from the
&packet variable itself. */
+ /* Write the adjusted value
back there, to give script */
+ /* the same lease time as we'll
use internally. */
+ move_to_unaligned32(temp,
htonl(lease_seconds));
+ }
//if (lease_seconds > 0x7fffffff)
// lease_seconds = 0x7fffffff;
//^^^not necessary since "timeout =
lease_seconds / 2"
//does not overflow even for 0xffffffff.
}
#if ENABLE_FEATURE_UDHCPC_ARPING
if (opt & OPT_a) {
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