From 15255a43e6c917813800702e100267046e240cc0 Mon Sep 17 00:00:00 2001 From: Jiri Pirko Date: Wed, 19 Nov 2014 14:05:00 +0100 Subject: [PATCH] vlan: introduce __vlan_insert_tag helper which does not free skb There's a need for helper which inserts vlan tag but does not free the skb in case of an error. Suggested-by: Pravin Shelar Signed-off-by: Jiri Pirko Acked-by: Pravin B Shelar Signed-off-by: David S. Miller --- include/linux/if_vlan.h | 45 ++++++++++++++++++++++++++++++++++----------- 1 file changed, 34 insertions(+), 11 deletions(-) diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h index 291e6706876e..515a35e2a48a 100644 --- a/include/linux/if_vlan.h +++ b/include/linux/if_vlan.h @@ -282,28 +282,24 @@ static inline bool vlan_hw_offload_capable(netdev_features_t features, } /** - * vlan_insert_tag - regular VLAN tag inserting + * __vlan_insert_tag - regular VLAN tag inserting * @skb: skbuff to tag * @vlan_proto: VLAN encapsulation protocol * @vlan_tci: VLAN TCI to insert * * Inserts the VLAN tag into @skb as part of the payload - * Returns a VLAN tagged skb. If a new skb is created, @skb is freed. - * - * Following the skb_unshare() example, in case of error, the calling function - * doesn't have to worry about freeing the original skb. + * Returns error if skb_cow_head failes. * * Does not change skb->protocol so this function can be used during receive. */ -static inline struct sk_buff *vlan_insert_tag(struct sk_buff *skb, - __be16 vlan_proto, u16 vlan_tci) +static inline int __vlan_insert_tag(struct sk_buff *skb, + __be16 vlan_proto, u16 vlan_tci) { struct vlan_ethhdr *veth; - if (skb_cow_head(skb, VLAN_HLEN) < 0) { - dev_kfree_skb_any(skb); - return NULL; - } + if (skb_cow_head(skb, VLAN_HLEN) < 0) + return -ENOMEM; + veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN); /* Move the mac addresses to the beginning of the new header. */ @@ -316,6 +312,33 @@ static inline struct sk_buff *vlan_insert_tag(struct sk_buff *skb, /* now, the TCI */ veth->h_vlan_TCI = htons(vlan_tci); + return 0; +} + +/** + * vlan_insert_tag - regular VLAN tag inserting + * @skb: skbuff to tag + * @vlan_proto: VLAN encapsulation protocol + * @vlan_tci: VLAN TCI to insert + * + * Inserts the VLAN tag into @skb as part of the payload + * Returns a VLAN tagged skb. If a new skb is created, @skb is freed. + * + * Following the skb_unshare() example, in case of error, the calling function + * doesn't have to worry about freeing the original skb. + * + * Does not change skb->protocol so this function can be used during receive. + */ +static inline struct sk_buff *vlan_insert_tag(struct sk_buff *skb, + __be16 vlan_proto, u16 vlan_tci) +{ + int err; + + err = __vlan_insert_tag(skb, vlan_proto, vlan_tci); + if (err) { + dev_kfree_skb_any(skb); + return NULL; + } return skb; } -- 2.11.0