From: Pali Rohár <pali@kernel.org>
Date: Sun, 10 Jan 2021 18:09:25 +0000 (+0100)
Subject: pppd: Disable Duplicate Address Detection for IPv6 peer address
X-Git-Tag: ppp-2.5.0~85^2~2
X-Git-Url: https://git.ozlabs.org/?a=commitdiff_plain;h=5d97adda1862153e29f918b58a36831b2e038f9b;p=ppp.git

pppd: Disable Duplicate Address Detection for IPv6 peer address

IPv6 link-local addresses are negotiated via IPV6CP and therefore are
unique and not duplicate. Doing additional Duplicate Address Detection
is redundant and not needed, so disable it.

Signed-off-by: Pali Rohár <pali@kernel.org>
---

diff --git a/pppd/sys-linux.c b/pppd/sys-linux.c
index a7508fe..ca0db84 100644
--- a/pppd/sys-linux.c
+++ b/pppd/sys-linux.c
@@ -2885,7 +2885,7 @@ static int append_peer_ipv6_address(unsigned int iface, struct in6_addr *local_a
     ifa = NLMSG_DATA(nlmsg);
     ifa->ifa_family = AF_INET6;
     ifa->ifa_prefixlen = 128;
-    ifa->ifa_flags = IFA_F_PERMANENT;
+    ifa->ifa_flags = IFA_F_NODAD | IFA_F_PERMANENT;
     ifa->ifa_scope = RT_SCOPE_LINK;
     ifa->ifa_index = iface;