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Commit 959b71db authored by Björn Töpel's avatar Björn Töpel Committed by Daniel Borkmann
Browse files

xsk: remove rebind support 



Supporting rebind, i.e. after a successful bind the process can call
bind again without closing the socket, makes the AF_XDP setup state
machine more complex. Constrain the state space, by not supporting
rebind.

Signed-off-by: default avatarBjörn Töpel <bjorn.topel@intel.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
parent d849f9f9

net/xdp/xsk.c

+9 −21
Original line number Diff line number Diff line
@@ -227,14 +227,6 @@ static int xsk_init_queue(u32 entries, struct xsk_queue **queue, 
	return 0;

}



static void __xsk_release(struct xdp_sock *xs)

{

	/* Wait for driver to stop using the xdp socket. */

	synchronize_net();



	dev_put(xs->dev);

}



static int xsk_release(struct socket *sock)

{

	struct sock *sk = sock->sk;
@@ -251,7 +243,9 @@ static int xsk_release(struct socket *sock) 
	local_bh_enable();



	if (xs->dev) {

		__xsk_release(xs);

		/* Wait for driver to stop using the xdp socket. */

		synchronize_net();

		dev_put(xs->dev);

		xs->dev = NULL;

	}
@@ -285,9 +279,8 @@ static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len) 
{

	struct sockaddr_xdp *sxdp = (struct sockaddr_xdp *)addr;

	struct sock *sk = sock->sk;

	struct net_device *dev, *dev_curr;

	struct xdp_sock *xs = xdp_sk(sk);

	struct xdp_umem *old_umem = NULL;

	struct net_device *dev;

	int err = 0;



	if (addr_len < sizeof(struct sockaddr_xdp))
@@ -296,7 +289,11 @@ static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len) 
		return -EINVAL;



	mutex_lock(&xs->mutex);

	dev_curr = xs->dev;

	if (xs->dev) {

		err = -EBUSY;

		goto out_release;

	}



	dev = dev_get_by_index(sock_net(sk), sxdp->sxdp_ifindex);

	if (!dev) {

		err = -ENODEV;
@@ -343,7 +340,6 @@ static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len) 
		}



		xdp_get_umem(umem_xs->umem);

		old_umem = xs->umem;

		xs->umem = umem_xs->umem;

		sockfd_put(sock);

	} else if (!xs->umem || !xdp_umem_validate_queues(xs->umem)) {
@@ -355,14 +351,6 @@ static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len) 
		xskq_set_umem(xs->umem->cq, &xs->umem->props);

	}



	/* Rebind? */

	if (dev_curr && (dev_curr != dev ||

			 xs->queue_id != sxdp->sxdp_queue_id)) {

		__xsk_release(xs);

		if (old_umem)

			xdp_put_umem(old_umem);

	}



	xs->dev = dev;

	xs->queue_id = sxdp->sxdp_queue_id;