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: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
John Fastabend 2017-10-31 19:17:31 -07:00 committed by David S. Miller
parent 14fc0abafe
commit 04686ef299
3 changed files with 13 additions and 7 deletions

View File

@ -788,7 +788,6 @@ struct xdp_md {
enum sk_action {
SK_DROP = 0,
SK_PASS,
SK_REDIRECT,
};
#define BPF_TAG_SIZE 8

View File

@ -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);
}

View File

@ -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