add patch to set uradvd preferred lifetime to 0

patches/0002-add-patch-to-announce-node-prefix-with-preferred-lif.patch

+From d9632c77cdf45b65df2a31084ad63454c58e50aa Mon Sep 17 00:00:00 2001
+From: Nico <github@nicoboehr.de>
+Date: Thu, 3 Jun 2021 20:35:15 +0000
+Subject: [PATCH 2/2] add patch to announce node prefix with preferred lifetime
+ of 0
+
+---
+ ...radvd-adjust-preferred-lifetime-to-0.patch | 23 +++++++++++++++++++
+ 1 file changed, 23 insertions(+)
+ create mode 100644 patches/packages/gluon/0001-uradvd-adjust-preferred-lifetime-to-0.patch
+
+diff --git a/patches/packages/gluon/0001-uradvd-adjust-preferred-lifetime-to-0.patch b/patches/packages/gluon/0001-uradvd-adjust-preferred-lifetime-to-0.patch
+new file mode 100644
+index 00000000..b974a8b5
+--- /dev/null
++++ b/patches/packages/gluon/0001-uradvd-adjust-preferred-lifetime-to-0.patch
+@@ -0,0 +1,23 @@
++From: Nico <github@nicoboehr.de>
++Date: Thu, 3 Jun 2021 20:31:55 +0000
++Subject: uradvd: adjust preferred lifetime to 0
++
++When we announce a prefix from nodes which has a preferred lifetime
++of nonzero, clients can use this prefix as a source IP address.
++
++As we announce the same prefix for every segment, this won't work. Hence,
++set the preferred lifetime to 0 so nobody ever uses it as a source IP.
++
++diff --git a/net/uradvd/src/uradvd.c b/net/uradvd/src/uradvd.c
++index f6549f249518714e3d9210708b54cc23d85b26df..0edcfdcc02c3c1d513413d8cb580880e4ef9eab6 100644
++--- a/net/uradvd/src/uradvd.c
+++++ b/net/uradvd/src/uradvd.c
++@@ -62,7 +62,7 @@
++ 
++ /* These are in seconds */
++ #define AdvValidLifetime 86400u
++-#define AdvPreferredLifetime 14400u
+++#define AdvPreferredLifetime 0u
++ #define AdvDefaultLifetime 0u
++ #define AdvCurHopLimit 64u
++ #define AdvRDNSSLifetime 1200u
+-- 
+2.31.1
+