summaryrefslogtreecommitdiffstats
path: root/Documentation/networking/af_xdp.rst
diff options
context:
space:
mode:
authorEric Leblond <eric@regit.org>2019-06-21 22:13:10 +0200
committerAlexei Starovoitov <ast@kernel.org>2019-06-24 18:18:30 -0700
commit0bed61371f7d537ecb6e1833acf59a74ae183b37 (patch)
treefec3937ab54550da57718c313d1686231dd91030 /Documentation/networking/af_xdp.rst
parent900de4ac4953fcf5e25ea45bea5bb28e797b1420 (diff)
downloadlinux-0bed61371f7d537ecb6e1833acf59a74ae183b37.tar.bz2
xsk: sample kernel code is now in libbpf
Fix documentation that mention xdpsock_kern.c which has been replaced by code embedded in libbpf. Signed-off-by: Eric Leblond <eric@regit.org> Acked-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'Documentation/networking/af_xdp.rst')
-rw-r--r--Documentation/networking/af_xdp.rst16
1 files changed, 15 insertions, 1 deletions
diff --git a/Documentation/networking/af_xdp.rst b/Documentation/networking/af_xdp.rst
index 50bccbf68308..eeedc2e826aa 100644
--- a/Documentation/networking/af_xdp.rst
+++ b/Documentation/networking/af_xdp.rst
@@ -220,7 +220,21 @@ Usage
In order to use AF_XDP sockets there are two parts needed. The
user-space application and the XDP program. For a complete setup and
usage example, please refer to the sample application. The user-space
-side is xdpsock_user.c and the XDP side xdpsock_kern.c.
+side is xdpsock_user.c and the XDP side is part of libbpf.
+
+The XDP code sample included in tools/lib/bpf/xsk.c is the following::
+
+ SEC("xdp_sock") int xdp_sock_prog(struct xdp_md *ctx)
+ {
+ int index = ctx->rx_queue_index;
+
+ // A set entry here means that the correspnding queue_id
+ // has an active AF_XDP socket bound to it.
+ if (bpf_map_lookup_elem(&xsks_map, &index))
+ return bpf_redirect_map(&xsks_map, index, 0);
+
+ return XDP_PASS;
+ }
Naive ring dequeue and enqueue could look like this::