#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;
};
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;
};
/*
.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);
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);
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);
{
}
+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;
}
if (peer)
netif_carrier_off(peer);
+ if (priv->_xdp_prog)
+ veth_disable_xdp(dev);
+
return 0;
}
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.
*
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,
.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 | \
*/
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:
projects / users / hch / configfs.git / commitdiff