diff options
Diffstat (limited to 'drivers/net')
| -rw-r--r-- | drivers/net/veth.c | 374 |
1 files changed, 367 insertions, 7 deletions
diff --git a/drivers/net/veth.c b/drivers/net/veth.c index a69ad39ee57e..d3b9f10bea24 100644 --- a/drivers/net/veth.c +++ b/drivers/net/veth.c @@ -19,10 +19,18 @@ #include <net/xfrm.h> #include <linux/veth.h> #include <linux/module.h> +#include <linux/bpf.h> +#include <linux/filter.h> +#include <linux/ptr_ring.h> +#include <linux/skb_array.h> +#include <linux/bpf_trace.h> #define DRV_NAME "veth" #define DRV_VERSION "1.0" +#define VETH_RING_SIZE 256 +#define VETH_XDP_HEADROOM (XDP_PACKET_HEADROOM + NET_IP_ALIGN) + struct pcpu_vstats { u64 packets; u64 bytes; @@ -30,9 +38,16 @@ struct pcpu_vstats { }; struct veth_priv { + struct napi_struct xdp_napi; + struct net_device *dev; + struct bpf_prog __rcu *xdp_prog; + struct bpf_prog *_xdp_prog; struct net_device __rcu *peer; atomic64_t dropped; unsigned requested_headroom; + bool rx_notify_masked; + struct ptr_ring xdp_ring; + struct xdp_rxq_info xdp_rxq; }; /* @@ -98,11 +113,43 @@ static const struct ethtool_ops veth_ethtool_ops = { .get_link_ksettings = veth_get_link_ksettings, }; -static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev) +/* general routines */ + +static void __veth_xdp_flush(struct veth_priv *priv) +{ + /* Write ptr_ring before reading rx_notify_masked */ + smp_mb(); + if (!priv->rx_notify_masked) { + priv->rx_notify_masked = true; + napi_schedule(&priv->xdp_napi); + } +} + +static int veth_xdp_rx(struct veth_priv *priv, struct sk_buff *skb) +{ + if (unlikely(ptr_ring_produce(&priv->xdp_ring, skb))) { + dev_kfree_skb_any(skb); + return NET_RX_DROP; + } + + return NET_RX_SUCCESS; +} + +static int veth_forward_skb(struct net_device *dev, struct sk_buff *skb, bool xdp) { struct veth_priv *priv = netdev_priv(dev); + + return __dev_forward_skb(dev, skb) ?: xdp ? + veth_xdp_rx(priv, skb) : + netif_rx(skb); +} + +static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev) +{ + struct veth_priv *rcv_priv, *priv = netdev_priv(dev); struct net_device *rcv; int length = skb->len; + bool rcv_xdp = false; rcu_read_lock(); rcv = rcu_dereference(priv->peer); @@ -111,7 +158,10 @@ static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev) goto drop; } - if (likely(dev_forward_skb(rcv, skb) == NET_RX_SUCCESS)) { + rcv_priv = netdev_priv(rcv); + rcv_xdp = rcu_access_pointer(rcv_priv->xdp_prog); + + if (likely(veth_forward_skb(rcv, skb, rcv_xdp) == NET_RX_SUCCESS)) { struct pcpu_vstats *stats = this_cpu_ptr(dev->vstats); u64_stats_update_begin(&stats->syncp); @@ -122,14 +172,15 @@ static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev) drop: atomic64_inc(&priv->dropped); } + + if (rcv_xdp) + __veth_xdp_flush(rcv_priv); + rcu_read_unlock(); + return NETDEV_TX_OK; } -/* - * general routines - */ - static u64 veth_stats_one(struct pcpu_vstats *result, struct net_device *dev) { struct veth_priv *priv = netdev_priv(dev); @@ -179,18 +230,254 @@ static void veth_set_multicast_list(struct net_device *dev) { } +static struct sk_buff *veth_build_skb(void *head, int headroom, int len, + int buflen) +{ + struct sk_buff *skb; + + if (!buflen) { + buflen = SKB_DATA_ALIGN(headroom + len) + + SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); + } + skb = build_skb(head, buflen); + if (!skb) + return NULL; + + skb_reserve(skb, headroom); + skb_put(skb, len); + + return skb; +} + +static struct sk_buff *veth_xdp_rcv_skb(struct veth_priv *priv, + struct sk_buff *skb) +{ + u32 pktlen, headroom, act, metalen; + void *orig_data, *orig_data_end; + struct bpf_prog *xdp_prog; + int mac_len, delta, off; + struct xdp_buff xdp; + + rcu_read_lock(); + xdp_prog = rcu_dereference(priv->xdp_prog); + if (unlikely(!xdp_prog)) { + rcu_read_unlock(); + goto out; + } + + mac_len = skb->data - skb_mac_header(skb); + pktlen = skb->len + mac_len; + headroom = skb_headroom(skb) - mac_len; + + if (skb_shared(skb) || skb_head_is_locked(skb) || + skb_is_nonlinear(skb) || headroom < XDP_PACKET_HEADROOM) { + struct sk_buff *nskb; + int size, head_off; + void *head, *start; + struct page *page; + + size = SKB_DATA_ALIGN(VETH_XDP_HEADROOM + pktlen) + + SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); + if (size > PAGE_SIZE) + goto drop; + + page = alloc_page(GFP_ATOMIC | __GFP_NOWARN); + if (!page) + goto drop; + + head = page_address(page); + start = head + VETH_XDP_HEADROOM; + if (skb_copy_bits(skb, -mac_len, start, pktlen)) { + page_frag_free(head); + goto drop; + } + + nskb = veth_build_skb(head, + VETH_XDP_HEADROOM + mac_len, skb->len, + PAGE_SIZE); + if (!nskb) { + page_frag_free(head); + goto drop; + } + + skb_copy_header(nskb, skb); + head_off = skb_headroom(nskb) - skb_headroom(skb); + skb_headers_offset_update(nskb, head_off); + if (skb->sk) + skb_set_owner_w(nskb, skb->sk); + consume_skb(skb); + skb = nskb; + } + + xdp.data_hard_start = skb->head; + xdp.data = skb_mac_header(skb); + xdp.data_end = xdp.data + pktlen; + xdp.data_meta = xdp.data; + xdp.rxq = &priv->xdp_rxq; + orig_data = xdp.data; + orig_data_end = xdp.data_end; + + act = bpf_prog_run_xdp(xdp_prog, &xdp); + + switch (act) { + case XDP_PASS: + break; + default: + bpf_warn_invalid_xdp_action(act); + case XDP_ABORTED: + trace_xdp_exception(priv->dev, xdp_prog, act); + case XDP_DROP: + goto drop; + } + rcu_read_unlock(); + + delta = orig_data - xdp.data; + off = mac_len + delta; + if (off > 0) + __skb_push(skb, off); + else if (off < 0) + __skb_pull(skb, -off); + skb->mac_header -= delta; + off = xdp.data_end - orig_data_end; + if (off != 0) + __skb_put(skb, off); + skb->protocol = eth_type_trans(skb, priv->dev); + + metalen = xdp.data - xdp.data_meta; + if (metalen) + skb_metadata_set(skb, metalen); +out: + return skb; +drop: + rcu_read_unlock(); + kfree_skb(skb); + return NULL; +} + +static int veth_xdp_rcv(struct veth_priv *priv, int budget) +{ + int i, done = 0; + + for (i = 0; i < budget; i++) { + struct sk_buff *skb = __ptr_ring_consume(&priv->xdp_ring); + + if (!skb) + break; + + skb = veth_xdp_rcv_skb(priv, skb); + + if (skb) + napi_gro_receive(&priv->xdp_napi, skb); + + done++; + } + + return done; +} + +static int veth_poll(struct napi_struct *napi, int budget) +{ + struct veth_priv *priv = + container_of(napi, struct veth_priv, xdp_napi); + int done; + + done = veth_xdp_rcv(priv, budget); + + if (done < budget && napi_complete_done(napi, done)) { + /* Write rx_notify_masked before reading ptr_ring */ + smp_store_mb(priv->rx_notify_masked, false); + if (unlikely(!__ptr_ring_empty(&priv->xdp_ring))) { + priv->rx_notify_masked = true; + napi_schedule(&priv->xdp_napi); + } + } + + return done; +} + +static int veth_napi_add(struct net_device *dev) +{ + struct veth_priv *priv = netdev_priv(dev); + int err; + + err = ptr_ring_init(&priv->xdp_ring, VETH_RING_SIZE, GFP_KERNEL); + if (err) + return err; + + netif_napi_add(dev, &priv->xdp_napi, veth_poll, NAPI_POLL_WEIGHT); + napi_enable(&priv->xdp_napi); + + return 0; +} + +static void veth_napi_del(struct net_device *dev) +{ + struct veth_priv *priv = netdev_priv(dev); + + napi_disable(&priv->xdp_napi); + netif_napi_del(&priv->xdp_napi); + priv->rx_notify_masked = false; + ptr_ring_cleanup(&priv->xdp_ring, __skb_array_destroy_skb); +} + +static int veth_enable_xdp(struct net_device *dev) +{ + struct veth_priv *priv = netdev_priv(dev); + int err; + + if (!xdp_rxq_info_is_reg(&priv->xdp_rxq)) { + err = xdp_rxq_info_reg(&priv->xdp_rxq, dev, 0); + if (err < 0) + return err; + + err = xdp_rxq_info_reg_mem_model(&priv->xdp_rxq, + MEM_TYPE_PAGE_SHARED, NULL); + if (err < 0) + goto err; + + err = veth_napi_add(dev); + if (err) + goto err; + } + + rcu_assign_pointer(priv->xdp_prog, priv->_xdp_prog); + + return 0; +err: + xdp_rxq_info_unreg(&priv->xdp_rxq); + + return err; +} + +static void veth_disable_xdp(struct net_device *dev) +{ + struct veth_priv *priv = netdev_priv(dev); + + rcu_assign_pointer(priv->xdp_prog, NULL); + veth_napi_del(dev); + xdp_rxq_info_unreg(&priv->xdp_rxq); +} + static int veth_open(struct net_device *dev) { struct veth_priv *priv = netdev_priv(dev); struct net_device *peer = rtnl_dereference(priv->peer); + int err; if (!peer) return -ENOTCONN; + if (priv->_xdp_prog) { + err = veth_enable_xdp(dev); + if (err) + return err; + } + if (peer->flags & IFF_UP) { netif_carrier_on(dev); netif_carrier_on(peer); } + return 0; } @@ -203,6 +490,9 @@ static int veth_close(struct net_device *dev) if (peer) netif_carrier_off(peer); + if (priv->_xdp_prog) + veth_disable_xdp(dev); + return 0; } @@ -228,7 +518,7 @@ static void veth_dev_free(struct net_device *dev) static void veth_poll_controller(struct net_device *dev) { /* veth only receives frames when its peer sends one - * Since it's a synchronous operation, we are guaranteed + * Since it has nothing to do with disabling irqs, we are guaranteed * never to have pending data when we poll for it so * there is nothing to do here. * @@ -276,6 +566,72 @@ out: rcu_read_unlock(); } +static int veth_xdp_set(struct net_device *dev, struct bpf_prog *prog, + struct netlink_ext_ack *extack) +{ + struct veth_priv *priv = netdev_priv(dev); + struct bpf_prog *old_prog; + struct net_device *peer; + int err; + + old_prog = priv->_xdp_prog; + priv->_xdp_prog = prog; + peer = rtnl_dereference(priv->peer); + + if (prog) { + if (!peer) { + NL_SET_ERR_MSG_MOD(extack, "Cannot set XDP when peer is detached"); + err = -ENOTCONN; + goto err; + } + + if (dev->flags & IFF_UP) { + err = veth_enable_xdp(dev); + if (err) { + NL_SET_ERR_MSG_MOD(extack, "Setup for XDP failed"); + goto err; + } + } + } + + if (old_prog) { + if (!prog && dev->flags & IFF_UP) + veth_disable_xdp(dev); + bpf_prog_put(old_prog); + } + + return 0; +err: + priv->_xdp_prog = old_prog; + + return err; +} + +static u32 veth_xdp_query(struct net_device *dev) +{ + struct veth_priv *priv = netdev_priv(dev); + const struct bpf_prog *xdp_prog; + + xdp_prog = priv->_xdp_prog; + if (xdp_prog) + return xdp_prog->aux->id; + + return 0; +} + +static int veth_xdp(struct net_device *dev, struct netdev_bpf *xdp) +{ + switch (xdp->command) { + case XDP_SETUP_PROG: + return veth_xdp_set(dev, xdp->prog, xdp->extack); + case XDP_QUERY_PROG: + xdp->prog_id = veth_xdp_query(dev); + return 0; + default: + return -EINVAL; + } +} + static const struct net_device_ops veth_netdev_ops = { .ndo_init = veth_dev_init, .ndo_open = veth_open, @@ -290,6 +646,7 @@ static const struct net_device_ops veth_netdev_ops = { .ndo_get_iflink = veth_get_iflink, .ndo_features_check = passthru_features_check, .ndo_set_rx_headroom = veth_set_rx_headroom, + .ndo_bpf = veth_xdp, }; #define VETH_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HW_CSUM | \ @@ -451,10 +808,13 @@ static int veth_newlink(struct net *src_net, struct net_device *dev, */ priv = netdev_priv(dev); + priv->dev = dev; rcu_assign_pointer(priv->peer, peer); priv = netdev_priv(peer); + priv->dev = peer; rcu_assign_pointer(priv->peer, dev); + return 0; err_register_dev: |