From 90b602f80397657429373ca009f98aec4dd3c553 Mon Sep 17 00:00:00 2001 From: Miroslav Lichvar Date: Fri, 19 May 2017 17:52:37 +0200 Subject: [PATCH] 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 Suggested-by: Willem de Bruijn Acked-by: Willem de Bruijn Signed-off-by: Miroslav Lichvar Signed-off-by: David S. Miller --- include/linux/netdevice.h | 1 + include/linux/skbuff.h | 9 +++++++++ net/core/dev.c | 26 ++++++++++++++++++++++++++ 3 files changed, 36 insertions(+) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index f8f7cd52a0a0..c50c9218e31e 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -2456,6 +2456,7 @@ static inline int dev_recursion_level(void) struct net_device *dev_get_by_index(struct net *net, int ifindex); struct net_device *__dev_get_by_index(struct net *net, int ifindex); struct net_device *dev_get_by_index_rcu(struct net *net, int ifindex); +struct net_device *dev_get_by_napi_id(unsigned int napi_id); int netdev_get_name(struct net *net, char *name, int ifindex); int dev_restart(struct net_device *dev); int skb_gro_receive(struct sk_buff **head, struct sk_buff *skb); diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 1713e4b7ea9f..8acce7143f6a 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -858,6 +858,15 @@ static inline bool skb_pkt_type_ok(u32 ptype) return ptype <= PACKET_OTHERHOST; } +static inline unsigned int skb_napi_id(const struct sk_buff *skb) +{ +#ifdef CONFIG_NET_RX_BUSY_POLL + return skb->napi_id; +#else + return 0; +#endif +} + void kfree_skb(struct sk_buff *skb); void kfree_skb_list(struct sk_buff *segs); void skb_tx_error(struct sk_buff *skb); 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. -- 2.11.0