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Commit 04686ef2 authored by John Fastabend's avatar John Fastabend Committed by David S. Miller
Browse files

bpf: remove SK_REDIRECT from UAPI 



Now that SK_REDIRECT is no longer a valid return code. Remove it
from the UAPI completely. Then do a namespace remapping internal
to sockmap so SK_REDIRECT is no longer externally visible.

Patchs primary change is to do a namechange from SK_REDIRECT to
__SK_REDIRECT

Reported-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarJohn Fastabend <john.fastabend@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 14fc0aba

include/uapi/linux/bpf.h

+0 −1
Original line number Diff line number Diff line
@@ -788,7 +788,6 @@ struct xdp_md { 
enum sk_action {

	SK_DROP = 0,

	SK_PASS,

	SK_REDIRECT,

};



#define BPF_TAG_SIZE	8

kernel/bpf/sockmap.c

+12 −4
Original line number Diff line number Diff line
@@ -101,13 +101,19 @@ static inline void bpf_compute_data_end_sk_skb(struct sk_buff *skb) 
	TCP_SKB_CB(skb)->bpf.data_end = skb->data + skb_headlen(skb);

}



enum __sk_action {

	__SK_DROP = 0,

	__SK_PASS,

	__SK_REDIRECT,

};



static int smap_verdict_func(struct smap_psock *psock, struct sk_buff *skb)

{

	struct bpf_prog *prog = READ_ONCE(psock->bpf_verdict);

	int rc;



	if (unlikely(!prog))

		return SK_DROP;

		return __SK_DROP;



	skb_orphan(skb);

	/* We need to ensure that BPF metadata for maps is also cleared
@@ -122,8 +128,10 @@ static int smap_verdict_func(struct smap_psock *psock, struct sk_buff *skb) 
	preempt_enable();

	skb->sk = NULL;



	/* Moving return codes from UAPI namespace into internal namespace */

	return rc == SK_PASS ?

		(TCP_SKB_CB(skb)->bpf.map ? SK_REDIRECT : SK_PASS) : SK_DROP;

		(TCP_SKB_CB(skb)->bpf.map ? __SK_REDIRECT : __SK_PASS) :

		__SK_DROP;

}



static void smap_do_verdict(struct smap_psock *psock, struct sk_buff *skb)
@@ -133,7 +141,7 @@ static void smap_do_verdict(struct smap_psock *psock, struct sk_buff *skb) 


	rc = smap_verdict_func(psock, skb);

	switch (rc) {

	case SK_REDIRECT:

	case __SK_REDIRECT:

		sk = do_sk_redirect_map(skb);

		if (likely(sk)) {

			struct smap_psock *peer = smap_psock_sk(sk);
@@ -149,7 +157,7 @@ static void smap_do_verdict(struct smap_psock *psock, struct sk_buff *skb) 
			}

		}

	/* Fall through and free skb otherwise */

	case SK_DROP:

	case __SK_DROP:

	default:

		kfree_skb(skb);

	}

tools/include/uapi/linux/bpf.h

+1 −2
Original line number Diff line number Diff line
@@ -576,7 +576,7 @@ union bpf_attr { 
 *     @map: pointer to sockmap

 *     @key: key to lookup sock in map

 *     @flags: reserved for future use

 *     Return: SK_REDIRECT

 *     Return: SK_PASS

 *

 * int bpf_sock_map_update(skops, map, key, flags)

 *	@skops: pointer to bpf_sock_ops
@@ -789,7 +789,6 @@ struct xdp_md { 
enum sk_action {

	SK_DROP = 0,

	SK_PASS,

	SK_REDIRECT,

};



#define BPF_TAG_SIZE	8