From: Magnus Karlsson Date: Wed, 2 May 2018 11:01:26 +0000 (+0200) Subject: xsk: add support for bind for Rx X-Git-Tag: v4.18-rc1~114^2~304^2~4^2~10 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=965a990984432cd01a9eb3514c64d86f56704295;p=linux.git 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 --- diff --git a/include/net/xdp_sock.h b/include/net/xdp_sock.h index db9a321de087..85d02512f59b 100644 --- a/include/net/xdp_sock.h +++ b/include/net/xdp_sock.h @@ -28,6 +28,7 @@ struct xdp_sock { struct xsk_queue *rx; struct net_device *dev; struct xdp_umem *umem; + u16 queue_id; /* Protects multiple processes in the control path */ struct mutex mutex; }; diff --git a/include/uapi/linux/if_xdp.h b/include/uapi/linux/if_xdp.h index 65324558829d..e5091881f776 100644 --- a/include/uapi/linux/if_xdp.h +++ b/include/uapi/linux/if_xdp.h @@ -21,6 +21,17 @@ #include +/* Options for the sxdp_flags field */ +#define XDP_SHARED_UMEM 1 + +struct sockaddr_xdp { + __u16 sxdp_family; + __u32 sxdp_ifindex; + __u32 sxdp_queue_id; + __u32 sxdp_shared_umem_fd; + __u16 sxdp_flags; +}; + /* XDP socket options */ #define XDP_RX_RING 1 #define XDP_UMEM_REG 3 diff --git a/net/xdp/xdp_umem.c b/net/xdp/xdp_umem.c index e1f627d0cc1c..9bac1ad570fa 100644 --- a/net/xdp/xdp_umem.c +++ b/net/xdp/xdp_umem.c @@ -248,3 +248,8 @@ int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr) put_pid(umem->pid); return err; } + +bool xdp_umem_validate_queues(struct xdp_umem *umem) +{ + return umem->fq; +} diff --git a/net/xdp/xdp_umem.h b/net/xdp/xdp_umem.h index 25634b8a5c6f..b13133e9c501 100644 --- a/net/xdp/xdp_umem.h +++ b/net/xdp/xdp_umem.h @@ -39,6 +39,7 @@ struct xdp_umem { struct work_struct work; }; +bool xdp_umem_validate_queues(struct xdp_umem *umem); int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr); void xdp_get_umem(struct xdp_umem *umem); void xdp_put_umem(struct xdp_umem *umem); 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, diff --git a/net/xdp/xsk_queue.c b/net/xdp/xsk_queue.c index 894f9f89afc7..d012e5e23591 100644 --- a/net/xdp/xsk_queue.c +++ b/net/xdp/xsk_queue.c @@ -16,6 +16,14 @@ #include "xsk_queue.h" +void xskq_set_umem(struct xsk_queue *q, struct xdp_umem_props *umem_props) +{ + if (!q) + return; + + q->umem_props = *umem_props; +} + static u32 xskq_umem_get_ring_size(struct xsk_queue *q) { return sizeof(struct xdp_umem_ring) + q->nentries * sizeof(u32); diff --git a/net/xdp/xsk_queue.h b/net/xdp/xsk_queue.h index 5439fa381763..9ddd2ee07a84 100644 --- a/net/xdp/xsk_queue.h +++ b/net/xdp/xsk_queue.h @@ -32,6 +32,7 @@ struct xsk_queue { u64 invalid_descs; }; +void xskq_set_umem(struct xsk_queue *q, struct xdp_umem_props *umem_props); struct xsk_queue *xskq_create(u32 nentries, bool umem_queue); void xskq_destroy(struct xsk_queue *q);