From 965a990984432cd01a9eb3514c64d86f56704295 Mon Sep 17 00:00:00 2001 From: Magnus Karlsson Date: Wed, 2 May 2018 13:01:26 +0200 Subject: xsk: add support for bind for Rx Here, the bind syscall is added. Binding an AF_XDP socket, means associating the socket to an umem, a netdev and a queue index. This can be done in two ways. The first way, creating a "socket from scratch". Create the umem using the XDP_UMEM_REG setsockopt and an associated fill queue with XDP_UMEM_FILL_QUEUE. Create the Rx queue using the XDP_RX_QUEUE setsockopt. Call bind passing ifindex and queue index ("channel" in ethtool speak). The second way to bind a socket, is simply skipping the umem/netdev/queue index, and passing another already setup AF_XDP socket. The new socket will then have the same umem/netdev/queue index as the parent so it will share the same umem. You must also set the flags field in the socket address to XDP_SHARED_UMEM. v2: Use PTR_ERR instead of passing error variable explicitly. Signed-off-by: Magnus Karlsson Signed-off-by: Alexei Starovoitov --- net/xdp/xsk.c | 124 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 123 insertions(+), 1 deletion(-) (limited to 'net/xdp/xsk.c') diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c index 92bd9b7e548f..bf2c97b87992 100644 --- a/net/xdp/xsk.c +++ b/net/xdp/xsk.c @@ -57,9 +57,18 @@ 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; + struct xdp_sock *xs = xdp_sk(sk); struct net *net; if (!sk) @@ -71,6 +80,11 @@ static int xsk_release(struct socket *sock) sock_prot_inuse_add(net, sk->sk_prot, -1); local_bh_enable(); + if (xs->dev) { + __xsk_release(xs); + xs->dev = NULL; + } + sock_orphan(sk); sock->sk = NULL; @@ -80,6 +94,114 @@ static int xsk_release(struct socket *sock) return 0; } +static struct socket *xsk_lookup_xsk_from_fd(int fd) +{ + struct socket *sock; + int err; + + sock = sockfd_lookup(fd, &err); + if (!sock) + return ERR_PTR(-ENOTSOCK); + + if (sock->sk->sk_family != PF_XDP) { + sockfd_put(sock); + return ERR_PTR(-ENOPROTOOPT); + } + + return sock; +} + +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; + int err = 0; + + if (addr_len < sizeof(struct sockaddr_xdp)) + return -EINVAL; + if (sxdp->sxdp_family != AF_XDP) + return -EINVAL; + + mutex_lock(&xs->mutex); + dev_curr = xs->dev; + dev = dev_get_by_index(sock_net(sk), sxdp->sxdp_ifindex); + if (!dev) { + err = -ENODEV; + goto out_release; + } + + if (!xs->rx) { + err = -EINVAL; + goto out_unlock; + } + + if (sxdp->sxdp_queue_id >= dev->num_rx_queues) { + err = -EINVAL; + goto out_unlock; + } + + if (sxdp->sxdp_flags & XDP_SHARED_UMEM) { + struct xdp_sock *umem_xs; + struct socket *sock; + + if (xs->umem) { + /* We have already our own. */ + err = -EINVAL; + goto out_unlock; + } + + sock = xsk_lookup_xsk_from_fd(sxdp->sxdp_shared_umem_fd); + if (IS_ERR(sock)) { + err = PTR_ERR(sock); + goto out_unlock; + } + + umem_xs = xdp_sk(sock->sk); + if (!umem_xs->umem) { + /* No umem to inherit. */ + err = -EBADF; + sockfd_put(sock); + goto out_unlock; + } else if (umem_xs->dev != dev || + umem_xs->queue_id != sxdp->sxdp_queue_id) { + err = -EINVAL; + sockfd_put(sock); + goto out_unlock; + } + + 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)) { + err = -EINVAL; + goto out_unlock; + } + + /* 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; + + xskq_set_umem(xs->rx, &xs->umem->props); + +out_unlock: + if (err) + dev_put(dev); +out_release: + mutex_unlock(&xs->mutex); + return err; +} + static int xsk_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen) { @@ -203,7 +325,7 @@ static const struct proto_ops xsk_proto_ops = { .family = PF_XDP, .owner = THIS_MODULE, .release = xsk_release, - .bind = sock_no_bind, + .bind = xsk_bind, .connect = sock_no_connect, .socketpair = sock_no_socketpair, .accept = sock_no_accept, -- cgit v1.2.3