openwrtv4/package/network/services/dnsmasq/patches/010-Tweak-ICMP-ping-check-logic-for-DHCPv4.patch
Hans Dedecker f33de80232 dnsmasq: backport tweak ICMP ping logic for DHCPv4
Don't start ping-check of address in DHCP discover if there already
exists a lease for the address. It has been reported under some
circumstances android and netbooted windows devices can reply to
ICMP pings if they have a lease and thus block the allocation of
the IP address the device already has during boot.

Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>
2017-06-26 10:49:13 +02:00

25 lines
1.1 KiB
Diff

From 4bb68866a8aeb31db8100492bceae051e33be5d0 Mon Sep 17 00:00:00 2001
From: Simon Kelley <simon@thekelleys.org.uk>
Date: Thu, 15 Jun 2017 23:18:44 +0100
Subject: [PATCH] Tweak ICMP ping check logic for DHCPv4.
---
src/rfc2131.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/src/rfc2131.c b/src/rfc2131.c
index 1c850e5..75792da 100644
--- a/src/rfc2131.c
+++ b/src/rfc2131.c
@@ -1040,7 +1040,7 @@ size_t dhcp_reply(struct dhcp_context *context, char *iface_name, int int_index,
else if (have_config(config, CONFIG_DECLINED) &&
difftime(now, config->decline_time) < (float)DECLINE_BACKOFF)
my_syslog(MS_DHCP | LOG_WARNING, _("not using configured address %s because it was previously declined"), addrs);
- else if (!do_icmp_ping(now, config->addr, 0, loopback))
+ else if ((!lease || lease->addr.s_addr != config->addr.s_addr) && !do_icmp_ping(now, config->addr, 0, loopback))
my_syslog(MS_DHCP | LOG_WARNING, _("not using configured address %s because it is in use by another host"), addrs);
else
conf = config->addr;
--
1.9.1