[git commit] udhcpc: account for script run time

[Denys Vlasenko]

commit: http://git.busybox.net/busybox/commit/?id=28634924f0950f1938ea74a7808d412dc1063fd0
branch: http://git.busybox.net/busybox/commit/?id=refs/heads/master

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 at googlemail.com>
---
 networking/udhcp/dhcpc.c |    6 +++++-
 1 files changed, 5 insertions(+), 1 deletions(-)

diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c
index 35e7c20..a34829c 100644
--- a/networking/udhcp/dhcpc.c
+++ b/networking/udhcp/dhcpc.c
@@ -1697,6 +1697,7 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
 		case RENEW_REQUESTED:
 		case REBINDING:
 			if (*message == DHCPACK) {
+				unsigned start;
 				uint32_t lease_seconds;
 				struct in_addr temp_addr;
 				uint8_t *temp;
@@ -1756,7 +1757,10 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
 				bb_info_msg("Lease of %s obtained, lease time %u",
 					inet_ntoa(temp_addr), (unsigned)lease_seconds);
 				requested_ip = packet.yiaddr;
+
+				start = monotonic_sec();
 				udhcp_run_script(&packet, state == REQUESTING ? "bound" : "renew");
+				already_waited_sec = (unsigned)monotonic_sec() - start;
 
 				state = BOUND;
 				change_listen_mode(LISTEN_NONE);
@@ -1774,7 +1778,7 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
 #endif
 				/* make future renew packets use different xid */
 				/* xid = random_xid(); ...but why bother? */
-				already_waited_sec = 0;
+
 				continue; /* back to main loop */
 			}
 			if (*message == DHCPNAK) {