nixpkgs/pkgs/os-specific/linux/systemd/0007-Ignore-IPv6-link-local-addresses.patch

From 72a89fd9b4e35da375a1cdcf0d30a0f31a78d9a5 Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <eelco.dolstra@logicblox.com>
Date: Mon, 4 Feb 2013 12:41:14 +0100
Subject: [PATCH 7/8] Ignore IPv6 link-local addresses

Returning IPv6 link-local addresses is a bad idea, because they only
work if an application connects specifically over the corresponding
interface.  So you get errors like:

  $ curl -6 http://my-machine/
  curl: (7) Failed to connect to fe80::d6be:d9ff:fe1b:8477: Invalid argument

To prevent this, this patch filters out link-local addresses.  So if
you don't have a routable IPv6 address, nss-myhostname will fall back
to returning ::1.
---
 src/nss-myhostname/netlink.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/nss-myhostname/netlink.c b/src/nss-myhostname/netlink.c
index b1ef912..4f2ab5c 100644
--- a/src/nss-myhostname/netlink.c
+++ b/src/nss-myhostname/netlink.c
@@ -113,6 +113,10 @@ static int read_reply(int fd, struct address **list, unsigned *n_list) {
                     ifaddrmsg->ifa_scope == RT_SCOPE_NOWHERE)
                         continue;
 
+                if (ifaddrmsg->ifa_family == AF_INET6 &&
+                    ifaddrmsg->ifa_scope == RT_SCOPE_LINK)
+                        continue;
+
                 if (ifaddrmsg->ifa_flags & IFA_F_DEPRECATED)
                         continue;
 
-- 
1.8.1