net: sock: introduce SOCK_XDP
This patch introduces a new sock flag - SOCK_XDP. This will be used
for notifying the upper layer that XDP program is attached on the
lower socket, and requires for extra headroom.
TUN will be the first user.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index ebd07ad..2c548bd 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -869,6 +869,9 @@ static int tun_attach(struct tun_struct *tun, struct file *file,
tun_napi_init(tun, tfile, napi);
}
+ if (rtnl_dereference(tun->xdp_prog))
+ sock_set_flag(&tfile->sk, SOCK_XDP);
+
tun_set_real_num_queues(tun);
/* device is allowed to go away first, so no need to hold extra
@@ -1241,13 +1244,29 @@ static int tun_xdp_set(struct net_device *dev, struct bpf_prog *prog,
struct netlink_ext_ack *extack)
{
struct tun_struct *tun = netdev_priv(dev);
+ struct tun_file *tfile;
struct bpf_prog *old_prog;
+ int i;
old_prog = rtnl_dereference(tun->xdp_prog);
rcu_assign_pointer(tun->xdp_prog, prog);
if (old_prog)
bpf_prog_put(old_prog);
+ for (i = 0; i < tun->numqueues; i++) {
+ tfile = rtnl_dereference(tun->tfiles[i]);
+ if (prog)
+ sock_set_flag(&tfile->sk, SOCK_XDP);
+ else
+ sock_reset_flag(&tfile->sk, SOCK_XDP);
+ }
+ list_for_each_entry(tfile, &tun->disabled, next) {
+ if (prog)
+ sock_set_flag(&tfile->sk, SOCK_XDP);
+ else
+ sock_reset_flag(&tfile->sk, SOCK_XDP);
+ }
+
return 0;
}