Commit 174e2381 authored by Florian Westphal's avatar Florian Westphal Committed by David S. Miller
Browse files

sk_buff: drop all skb extensions on free and skb scrubbing 



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: 95a7233c ("net: openvswitch: Set OvS recirc_id from tc chain index")
Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 6b3656a6

include/linux/skbuff.h

+9 −0
Original line number Diff line number Diff line
@@ -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) {}

net/core/dev.c

+2 −2
Original line number Diff line number Diff line
@@ -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;

}

net/core/skbuff.c

+1 −1
Original line number Diff line number Diff line
@@ -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);

CRA Git | Maintained and supported by SUSTech CRA and CCSE