bpf, xdp: Start using the BPF dispatcher for XDP
This commit adds a BPF dispatcher for XDP. The dispatcher is updated
from the XDP control-path, dev_xdp_install(), and used when an XDP
program is run via bpf_prog_run_xdp().
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191213175112.30208-4-bjorn.topel@gmail.com
diff --git a/net/core/dev.c b/net/core/dev.c
index 2c277b8..255d3cf 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -8542,7 +8542,17 @@ static int dev_xdp_install(struct net_device *dev, bpf_op_t bpf_op,
struct netlink_ext_ack *extack, u32 flags,
struct bpf_prog *prog)
{
+ bool non_hw = !(flags & XDP_FLAGS_HW_MODE);
+ struct bpf_prog *prev_prog = NULL;
struct netdev_bpf xdp;
+ int err;
+
+ if (non_hw) {
+ prev_prog = bpf_prog_by_id(__dev_xdp_query(dev, bpf_op,
+ XDP_QUERY_PROG));
+ if (IS_ERR(prev_prog))
+ prev_prog = NULL;
+ }
memset(&xdp, 0, sizeof(xdp));
if (flags & XDP_FLAGS_HW_MODE)
@@ -8553,7 +8563,14 @@ static int dev_xdp_install(struct net_device *dev, bpf_op_t bpf_op,
xdp.flags = flags;
xdp.prog = prog;
- return bpf_op(dev, &xdp);
+ err = bpf_op(dev, &xdp);
+ if (!err && non_hw)
+ bpf_prog_change_xdp(prev_prog, prog);
+
+ if (prev_prog)
+ bpf_prog_put(prev_prog);
+
+ return err;
}
static void dev_xdp_uninstall(struct net_device *dev)