[PATCH net-next] tun: use symmetric hash

From: Jason Wang
Date: Tue Jun 06 2017 - 02:10:03 EST


Tun actually expects a symmetric hash for queue selecting to work
correctly, otherwise packets belongs to a single flow may be
redirected to the wrong queue. So this patch switch to use
__skb_get_hash_symmetric().

Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
---
drivers/net/tun.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index f8041f9c..fe660e5 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -465,7 +465,7 @@ static u16 tun_select_queue(struct net_device *dev, struct sk_buff *skb,
rcu_read_lock();
numqueues = ACCESS_ONCE(tun->numqueues);

- txq = skb_get_hash(skb);
+ txq = __skb_get_hash_symmetric(skb);
if (txq) {
e = tun_flow_find(&tun->flows[tun_hashfn(txq)], txq);
if (e) {
@@ -867,7 +867,7 @@ static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
*/
__u32 rxhash;

- rxhash = skb_get_hash(skb);
+ rxhash = __skb_get_hash_symmetric(skb);
if (rxhash) {
struct tun_flow_entry *e;
e = tun_flow_find(&tun->flows[tun_hashfn(rxhash)],
@@ -1334,7 +1334,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
skb_reset_network_header(skb);
skb_probe_transport_header(skb, 0);

- rxhash = skb_get_hash(skb);
+ rxhash = __skb_get_hash_symmetric(skb);
#ifndef CONFIG_4KSTACKS
tun_rx_batched(tun, tfile, skb, more);
#else
--
2.7.4