From: John Fastabend <john.fastabend@gmail.com>
Date: Tue, 31 Oct 2017 19:17:31 -0700
Subject: bpf: remove SK_REDIRECT from UAPI
Patch-mainline: v4.14-rc8
Git-commit: 04686ef299db5ff299bfc5a4504b189e46842078
References: bsc#1109837
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>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
include/uapi/linux/bpf.h | 1 -
kernel/bpf/sockmap.c | 16 ++++++++++++----
tools/include/uapi/linux/bpf.h | 3 +--
3 files changed, 13 insertions(+), 7 deletions(-)
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -788,7 +788,6 @@ struct xdp_md {
enum sk_action {
SK_DROP = 0,
SK_PASS,
- SK_REDIRECT,
};
#define BPF_TAG_SIZE 8
--- a/kernel/bpf/sockmap.c
+++ b/kernel/bpf/sockmap.c
@@ -101,13 +101,19 @@ static inline void bpf_compute_data_end_
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
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_
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_
}
}
/* Fall through and free skb otherwise */
- case SK_DROP:
+ case __SK_DROP:
default:
kfree_skb(skb);
}
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -571,7 +571,7 @@ 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
@@ -781,7 +781,6 @@ struct xdp_md {
enum sk_action {
SK_DROP = 0,
SK_PASS,
- SK_REDIRECT,
};
#define BPF_TAG_SIZE 8