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sk_buff: drop all skb extensions on free and skb scrubbing

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Now that we have a 3rd extension, add a new helper that drops the
extension space and use it when we need to scrub an sk_buff.

At this time, scrubbing clears secpath and bridge netfilter data, but
retains the tc skb extension, after this patch all three get cleared.

NAPI reuse/free assumes we can only have a secpath attached to skb, but
it seems better to clear all extensions there as well.

v2: add unlikely hint (Eric Dumazet)

Fixes: 95a7233c45 ("net: openvswitch: Set OvS recirc_id from tc chain index")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Florian Westphal 2019-09-26 20:37:05 +02:00 committed by David S. Miller
parent 6b3656a60f
commit 174e23810c
3 changed files with 12 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
include/linux/skbuff.h
View File

@ -4144,8 +4144,17 @@ static inline void *skb_ext_find(const struct sk_buff *skb, enum skb_ext_id id)
return NULL;
}
static inline void skb_ext_reset(struct sk_buff *skb)
{
if (unlikely(skb->active_extensions)) {
__skb_ext_put(skb->extensions);
skb->active_extensions = 0;
}
}
#else
static inline void skb_ext_put(struct sk_buff *skb) {}
static inline void skb_ext_reset(struct sk_buff *skb) {}
static inline void skb_ext_del(struct sk_buff *skb, int unused) {}
static inline void __skb_ext_copy(struct sk_buff *d, const struct sk_buff *s) {}
static inline void skb_ext_copy(struct sk_buff *dst, const struct sk_buff *s) {}

4
net/core/dev.c
View File

@ -5666,7 +5666,7 @@ EXPORT_SYMBOL(gro_find_complete_by_type);
static void napi_skb_free_stolen_head(struct sk_buff *skb)
{
skb_dst_drop(skb);
secpath_reset(skb);
skb_ext_put(skb);
kmem_cache_free(skbuff_head_cache, skb);
}
@ -5733,7 +5733,7 @@ static void napi_reuse_skb(struct napi_struct *napi, struct sk_buff *skb)
skb->encapsulation = 0;
skb_shinfo(skb)->gso_type = 0;
skb->truesize = SKB_TRUESIZE(skb_end_offset(skb));
secpath_reset(skb);
skb_ext_reset(skb);
napi->skb = skb;
}

2
net/core/skbuff.c
View File

@ -5119,7 +5119,7 @@ void skb_scrub_packet(struct sk_buff *skb, bool xnet)
skb->skb_iif = 0;
skb->ignore_df = 0;
skb_dst_drop(skb);
secpath_reset(skb);
skb_ext_reset(skb);
nf_reset(skb);
nf_reset_trace(skb);