[PATCH 2/2] ipv6: fixup RTF_* flags when restoring RTPROT_RA route from rtnetlink

[Andrew Yourtchenko <ayourtch@gmail.com>]

Fix the flags for RA-derived routes that were saved
via "ip -6 route save" and and subsequently restored via
"ip -6 route restore", allowing the incoming router advertisements
to update them, rather than complain about inability to do so.

Upon the restore of RA-derived saved routes, set the RTF_ADDRCONF
to indicate that the source of the route was originally
a router advertisement, and set the RTF_DEFAULT or RTF_ROUTEINFO
flag depending on prefix length. This can be considered a
sister change of f0396f60d7c165018c9b203fb9b89fb224835578, in
the other direction.

Signed-off-by: Andrew Yourtchenko <ayourtch@gmail.com>
---
 net/ipv6/route.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index dc37017..4da7237 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -2769,6 +2769,16 @@ static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh,
 	cfg->fc_protocol = rtm->rtm_protocol;
 	cfg->fc_type = rtm->rtm_type;
 
+	if (rtm->rtm_protocol == RTPROT_RA) {
+	    /* RA-derived route: set flags accordingly. */
+	    cfg->fc_flags |= RTF_ADDRCONF;
+	    if (rtm->rtm_dst_len == 0) {
+		cfg->fc_flags |= RTF_DEFAULT;
+	    } else {
+		cfg->fc_flags |= RTF_ROUTEINFO;
+	    }
+	}
+
 	if (rtm->rtm_type == RTN_UNREACHABLE ||
 	    rtm->rtm_type == RTN_BLACKHOLE ||
 	    rtm->rtm_type == RTN_PROHIBIT ||
-- 
2.7.4