diff options
| author | Miroslav Lichvar <mlichvar@redhat.com> | 2017-05-19 17:52:37 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-05-21 13:37:32 -0400 |
| commit | 90b602f80397657429373ca009f98aec4dd3c553 (patch) | |
| tree | b6ce4214ce48199983704bf95540370472b5da44 /net/core | |
| parent | e3412575488ac2408f737a14296cce34c9d8b4f8 (diff) | |
net: add function to retrieve original skb device using NAPI ID
Since commit b68581778cd0 ("net: Make skb->skb_iif always track
skb->dev") skbs don't have the original index of the interface which
received the packet. This information is now needed for a new control
message related to hardware timestamping.
Instead of adding a new field to skb, we can find the device by the NAPI
ID if it is available, i.e. CONFIG_NET_RX_BUSY_POLL is enabled and the
driver is using NAPI. Add dev_get_by_napi_id() and also skb_napi_id() to
hide the CONFIG_NET_RX_BUSY_POLL ifdef.
CC: Richard Cochran <richardcochran@gmail.com>
Suggested-by: Willem de Bruijn <willemb@google.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Miroslav Lichvar <mlichvar@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/dev.c | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index bb136f726890..3d98fbf4cbb0 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -163,6 +163,7 @@ static int netif_rx_internal(struct sk_buff *skb); static int call_netdevice_notifiers_info(unsigned long val, struct net_device *dev, struct netdev_notifier_info *info); +static struct napi_struct *napi_by_id(unsigned int napi_id); /* * The @dev_base_head list is protected by @dev_base_lock and the rtnl @@ -867,6 +868,31 @@ struct net_device *dev_get_by_index(struct net *net, int ifindex) EXPORT_SYMBOL(dev_get_by_index); /** + * dev_get_by_napi_id - find a device by napi_id + * @napi_id: ID of the NAPI struct + * + * Search for an interface by NAPI ID. Returns %NULL if the device + * is not found or a pointer to the device. The device has not had + * its reference counter increased so the caller must be careful + * about locking. The caller must hold RCU lock. + */ + +struct net_device *dev_get_by_napi_id(unsigned int napi_id) +{ + struct napi_struct *napi; + + WARN_ON_ONCE(!rcu_read_lock_held()); + + if (napi_id < MIN_NAPI_ID) + return NULL; + + napi = napi_by_id(napi_id); + + return napi ? napi->dev : NULL; +} +EXPORT_SYMBOL(dev_get_by_napi_id); + +/** * netdev_get_name - get a netdevice name, knowing its ifindex. * @net: network namespace * @name: a pointer to the buffer where the name will be stored. |