Commit e5f7e211 authored by Davide Caratti's avatar Davide Caratti Committed by David S. Miller
Browse files

ip6gre: avoid tx_error when sending MLD/DAD on external tunnels 



similarly to what has been done with commit 9d149045 ("geneve: change
from tx_error to tx_dropped on missing metadata"), avoid reporting errors
to userspace in case the kernel doesn't find any tunnel information for a
skb that is going to be transmitted: an increase of tx_dropped is enough.

tested with the following script:

 # for t in ip6gre ip6gretap ip6erspan; do
 > ip link add dev gre6-test0 type $t external
 > ip address add dev gre6-test0 2001:db8::1/64
 > ip link set dev gre6-test0 up
 > sleep 30
 > ip -s -j link show dev gre6-test0 | jq \
 > '.[0].stats64.tx | {"errors": .errors, "dropped": .dropped}'
 > ip link del dev gre6-test0
 > done

Reported-by: default avatarJianlin Shi <jishi@redhat.com>
Signed-off-by: default avatarDavide Caratti <dcaratti@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent be589d04

net/ipv6/ip6_gre.c

+22 −11
Original line number Diff line number Diff line
@@ -707,6 +707,17 @@ static int prepare_ip6gre_xmit_ipv6(struct sk_buff *skb, 
	return 0;

}



static struct ip_tunnel_info *skb_tunnel_info_txcheck(struct sk_buff *skb)

{

	struct ip_tunnel_info *tun_info;



	tun_info = skb_tunnel_info(skb);

	if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX)))

		return ERR_PTR(-EINVAL);



	return tun_info;

}



static netdev_tx_t __gre6_xmit(struct sk_buff *skb,

			       struct net_device *dev, __u8 dsfield,

			       struct flowi6 *fl6, int encap_limit,
@@ -734,10 +745,9 @@ static netdev_tx_t __gre6_xmit(struct sk_buff *skb, 
		const struct ip_tunnel_key *key;

		__be16 flags;



		tun_info = skb_tunnel_info(skb);

		if (unlikely(!tun_info ||

			     !(tun_info->mode & IP_TUNNEL_INFO_TX) ||

			     ip_tunnel_info_af(tun_info) != AF_INET6))

		tun_info = skb_tunnel_info_txcheck(skb);

		if (IS_ERR(tun_info) ||

		    unlikely(ip_tunnel_info_af(tun_info) != AF_INET6))

			return -EINVAL;



		key = &tun_info->key;
@@ -908,6 +918,7 @@ static netdev_tx_t ip6gre_tunnel_xmit(struct sk_buff *skb, 
	return NETDEV_TX_OK;



tx_err:

	if (!t->parms.collect_md || !IS_ERR(skb_tunnel_info_txcheck(skb)))

		stats->tx_errors++;

	stats->tx_dropped++;

	kfree_skb(skb);
@@ -917,6 +928,7 @@ tx_err: 
static netdev_tx_t ip6erspan_tunnel_xmit(struct sk_buff *skb,

					 struct net_device *dev)

{

	struct ip_tunnel_info *tun_info = NULL;

	struct ip6_tnl *t = netdev_priv(dev);

	struct dst_entry *dst = skb_dst(skb);

	struct net_device_stats *stats;
@@ -964,15 +976,13 @@ static netdev_tx_t ip6erspan_tunnel_xmit(struct sk_buff *skb, 
	 * for native mode, call prepare_ip6gre_xmit_{ipv4,ipv6}.

	 */

	if (t->parms.collect_md) {

		struct ip_tunnel_info *tun_info;

		const struct ip_tunnel_key *key;

		struct erspan_metadata *md;

		__be32 tun_id;



		tun_info = skb_tunnel_info(skb);

		if (unlikely(!tun_info ||

			     !(tun_info->mode & IP_TUNNEL_INFO_TX) ||

			     ip_tunnel_info_af(tun_info) != AF_INET6))

		tun_info = skb_tunnel_info_txcheck(skb);

		if (IS_ERR(tun_info) ||

		    unlikely(ip_tunnel_info_af(tun_info) != AF_INET6))

			goto tx_err;



		key = &tun_info->key;
@@ -1065,6 +1075,7 @@ static netdev_tx_t ip6erspan_tunnel_xmit(struct sk_buff *skb, 


tx_err:

	stats = &t->dev->stats;

	if (!IS_ERR(tun_info))

		stats->tx_errors++;

	stats->tx_dropped++;

	kfree_skb(skb);

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