From 959b71db53e310bc63be22bfa3401aef30c6035d Mon Sep 17 00:00:00 2001 From: =?utf8?q?Bj=C3=B6rn=20T=C3=B6pel?= Date: Tue, 22 May 2018 09:34:56 +0200 Subject: [PATCH] xsk: remove rebind support MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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: Björn Töpel Signed-off-by: Daniel Borkmann --- net/xdp/xsk.c | 30 +++++++++--------------------- 1 file changed, 9 insertions(+), 21 deletions(-) diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c index 817340f7725d..cb1acd7009f4 100644 --- a/net/xdp/xsk.c +++ b/net/xdp/xsk.c @@ -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; -- 2.11.0