From 7cc7e0ec86f3ce701a3b829f54b49eab235e43d7 Mon Sep 17 00:00:00 2001 From: Michael Brown Date: Fri, 30 Oct 2015 13:18:51 +0000 Subject: [PATCH] [dhcp] Reset start time when deferring discovery If we detect (via STP) that a switch port is in a non-forwarding state, then the link is marked as being temporarily blocked and DHCP discovery will be deferred until the link becomes unblocked. The timer used to decide when to give up waiting for ProxyDHCPOFFERs is currently based on the time that DHCP discovery was started, and makes no allowances for any time spent waiting for the link to become unblocked. Consequently, if STP is used then the timeout for ProxyDHCPOFFERs becomes essentially zero. Fix by resetting the recorded start time whenever DHCP discovery is deferred due to a blocked link. Debugged-by: Sebastian Roth Signed-off-by: Michael Brown --- src/net/udp/dhcp.c | 1 + 1 file changed, 1 insertion(+) diff --git a/src/net/udp/dhcp.c b/src/net/udp/dhcp.c index 36c2b13a6..9c7b2fdc2 100644 --- a/src/net/udp/dhcp.c +++ b/src/net/udp/dhcp.c @@ -446,6 +446,7 @@ static void dhcp_discovery_expired ( struct dhcp_session *dhcp ) { /* If link is blocked, defer DHCP discovery (and reset timeout) */ if ( netdev_link_blocked ( dhcp->netdev ) ) { DBGC ( dhcp, "DHCP %p deferring discovery\n", dhcp ); + dhcp->start = currticks(); start_timer_fixed ( &dhcp->timer, ( DHCP_DISC_START_TIMEOUT_SEC * TICKS_PER_SEC ) );