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| author | John Fastabend <john.fastabend@gmail.com> | 2017-10-18 07:10:36 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-10-20 13:01:29 +0100 |
| commit | 34f79502bbcfab659b8729da68b5e387f96eb4c1 (patch) | |
| tree | 27084757c315fdf13c682c3d6c57922ed5f8447c /samples | |
| parent | 435bf0d3f99a164df7e8c30428cef266b91d1d3b (diff) | |
| download | lwn-34f79502bbcfab659b8729da68b5e387f96eb4c1.tar.gz lwn-34f79502bbcfab659b8729da68b5e387f96eb4c1.zip | |
bpf: avoid preempt enable/disable in sockmap using tcp_skb_cb region
SK_SKB BPF programs are run from the socket/tcp context but early in
the stack before much of the TCP metadata is needed in tcp_skb_cb. So
we can use some unused fields to place BPF metadata needed for SK_SKB
programs when implementing the redirect function.
This allows us to drop the preempt disable logic. It does however
require an API change so sk_redirect_map() has been updated to
additionally provide ctx_ptr to skb. Note, we do however continue to
disable/enable preemption around actual BPF program running to account
for map updates.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'samples')
| -rw-r--r-- | samples/sockmap/sockmap_kern.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/samples/sockmap/sockmap_kern.c b/samples/sockmap/sockmap_kern.c index f9b38ef82dc2..52b0053274f4 100644 --- a/samples/sockmap/sockmap_kern.c +++ b/samples/sockmap/sockmap_kern.c @@ -62,7 +62,7 @@ int bpf_prog2(struct __sk_buff *skb) ret = 1; bpf_printk("sockmap: %d -> %d @ %d\n", lport, bpf_ntohl(rport), ret); - return bpf_sk_redirect_map(&sock_map, ret, 0); + return bpf_sk_redirect_map(skb, &sock_map, ret, 0); } SEC("sockops") |