Package: dnsmasq
Version: 2.80-1
Severity: normal
Tags: ipv6 patch upstream
Hello,
Situation: My ISP doesn't offer IPv6 prefix delegation and just gives
/64 IPv6 address. I configure my router with ndppd (NDP Proxy
Daemon), running dnsmasq for internal network.
It mostly works, but I observed no periodical IPv6 Router
Advertisement (only reply to Router Solicitation) to internal network.
With a line in dnsmasq.conf:
no-dhcp-interface=<external_interface_with_same_ipv6_net>
interface=<internal_interface_with_ipv6_net>
I expected dnsmasq does IPv6 Router Advertisement, even though these
interfaces share same IPv6 network address. It does for Router
Solicitation request, but no periodical ones.
I think I found a problem in src/radv.c. When an interface is
searched, it doesn't skip interfaces with no-dhcp-interface, so,
invalid interface may be identified. (Note that in the periodic_ra
function, there is code to skip the interface _after_ interface is
identified.)
When I applied following patch, I started to observe IPv6 Router
Advertisement in internal network.
I'm not sure if this patch is correct, or good one. This is for
sharing the problem.
diff --git a/src/radv.c b/src/radv.c
index cad0530..82f9603 100644
--- a/src/radv.c
+++ b/src/radv.c
@@ -917,6 +917,17 @@ static int iface_search(struct in6_addr *local, int
prefix,
param->iface = 0;
return 0;
}
+
+ {
+ struct iname *tmp;
+ for (tmp = daemon->dhcp_except; tmp; tmp = tmp->next)
+ if (tmp->name && wildcard_match(tmp->name, param->name))
+ break;
+
+ /* Skip this interface. */
+ if (tmp)
+ return 1;
+ }
new_timeout(context, param->name, param->now);
-- System Information:
Debian Release: 10.2
APT prefers stable
APT policy: (990, 'stable'), (500, 'stable-debug'), (500, 'unstable'), (500,
'oldstable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386
Kernel: Linux 4.19.0-6-amd64 (SMP w/4 CPU cores)
Locale: LANG=C, LC_CTYPE=C.UTF-8 (charmap=UTF-8), LANGUAGE=C (charmap=UTF-8)
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled
Versions of packages dnsmasq depends on:
ii dnsmasq-base [dnsmasq-base] 2.80-1
ii init-system-helpers 1.56+nmu1
ii lsb-base 10.2019051400
ii netbase 5.6
dnsmasq recommends no packages.
Versions of packages dnsmasq suggests:
pn resolvconf <none>
-- Configuration Files:
/etc/default/dnsmasq changed [not included]
-- no debconf information
