ipv4: properly refresh rtable entries on pmtu/redirect events

This reverts commit 05ab86c5 (xfrm4: Invalidate all ipv4 routes on
IPsec pmtu events). Flushing all cached entries is not needed.

Instead, invalidate only the related next hop dsts to recheck for
the added next hop exception where needed. This also fixes a subtle
race due to bumping generation id's before updating the pmtu.

Cc: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Timo Teräs <timo.teras@iki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 5 deletions

diff --git a/net/ipv4/ah4.c b/net/ipv4/ah4.c
index 2e7f1948216f..717902669d2f 100644
--- a/net/ipv4/ah4.c
+++ b/net/ipv4/ah4.c
@@ -419,12 +419,9 @@ static void ah4_err(struct sk_buff *skb, u32 info)
         if (!x)
                 return;
 
-        if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH) {
-                atomic_inc(&flow_cache_genid);
-                rt_genid_bump(net);
-
+        if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
                 ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_AH, 0);
-        } else
+        else
                 ipv4_redirect(skb, net, 0, 0, IPPROTO_AH, 0);
         xfrm_state_put(x);
 }