net: use dst_confirm_neigh for UDP, RAW, ICMP, L2TP
When same struct dst_entry can be used for many different
neighbours we can not use it for pending confirmations.
The datagram protocols can use MSG_CONFIRM to confirm the
neighbour. When used with MSG_PROBE we do not reach the
code where neighbour is confirmed, so we have to do the
same slow lookup by using the dst_confirm_neigh() helper.
When MSG_PROBE is not used, ip_append_data/ip6_append_data
will set the skb flag dst_pending_confirm.
Reported-by: YueHaibing <yuehaibing@huawei.com>
Fixes: 5110effee8fd ("net: Do delayed neigh confirmation.")
Fixes: f2bb4bedf35d ("ipv4: Cache output routes in fib_info nexthops.")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 98b183f..f54f426 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1381,6 +1381,7 @@ static bool rt6_cache_allowed_for_pmtu(const struct rt6_info *rt)
static void __ip6_rt_update_pmtu(struct dst_entry *dst, const struct sock *sk,
const struct ipv6hdr *iph, u32 mtu)
{
+ const struct in6_addr *daddr, *saddr;
struct rt6_info *rt6 = (struct rt6_info *)dst;
if (rt6->rt6i_flags & RTF_LOCAL)
@@ -1389,26 +1390,26 @@ static void __ip6_rt_update_pmtu(struct dst_entry *dst, const struct sock *sk,
if (dst_metric_locked(dst, RTAX_MTU))
return;
- dst_confirm(dst);
+ if (iph) {
+ daddr = &iph->daddr;
+ saddr = &iph->saddr;
+ } else if (sk) {
+ daddr = &sk->sk_v6_daddr;
+ saddr = &inet6_sk(sk)->saddr;
+ } else {
+ daddr = NULL;
+ saddr = NULL;
+ }
+ dst_confirm_neigh(dst, daddr);
mtu = max_t(u32, mtu, IPV6_MIN_MTU);
if (mtu >= dst_mtu(dst))
return;
if (!rt6_cache_allowed_for_pmtu(rt6)) {
rt6_do_update_pmtu(rt6, mtu);
- } else {
- const struct in6_addr *daddr, *saddr;
+ } else if (daddr) {
struct rt6_info *nrt6;
- if (iph) {
- daddr = &iph->daddr;
- saddr = &iph->saddr;
- } else if (sk) {
- daddr = &sk->sk_v6_daddr;
- saddr = &inet6_sk(sk)->saddr;
- } else {
- return;
- }
nrt6 = ip6_rt_cache_alloc(rt6, daddr, saddr);
if (nrt6) {
rt6_do_update_pmtu(nrt6, mtu);
@@ -2332,7 +2333,7 @@ static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_bu
* Look, redirects are sent only in response to data packets,
* so that this nexthop apparently is reachable. --ANK
*/
- dst_confirm(&rt->dst);
+ dst_confirm_neigh(&rt->dst, &ipv6_hdr(skb)->saddr);
neigh = __neigh_lookup(&nd_tbl, &msg->target, skb->dev, 1);
if (!neigh)