v4.19.13 snapshot.
diff --git a/drivers/net/veth.c b/drivers/net/veth.c
new file mode 100644
index 0000000..41a00cd
--- /dev/null
+++ b/drivers/net/veth.c
@@ -0,0 +1,1264 @@
+/*
+ * drivers/net/veth.c
+ *
+ * Copyright (C) 2007 OpenVZ http://openvz.org, SWsoft Inc
+ *
+ * Author: Pavel Emelianov <xemul@openvz.org>
+ * Ethtool interface from: Eric W. Biederman <ebiederm@xmission.com>
+ *
+ */
+
+#include <linux/netdevice.h>
+#include <linux/slab.h>
+#include <linux/ethtool.h>
+#include <linux/etherdevice.h>
+#include <linux/u64_stats_sync.h>
+
+#include <net/rtnetlink.h>
+#include <net/dst.h>
+#include <net/xfrm.h>
+#include <net/xdp.h>
+#include <linux/veth.h>
+#include <linux/module.h>
+#include <linux/bpf.h>
+#include <linux/filter.h>
+#include <linux/ptr_ring.h>
+#include <linux/bpf_trace.h>
+
+#define DRV_NAME "veth"
+#define DRV_VERSION "1.0"
+
+#define VETH_XDP_FLAG BIT(0)
+#define VETH_RING_SIZE 256
+#define VETH_XDP_HEADROOM (XDP_PACKET_HEADROOM + NET_IP_ALIGN)
+
+/* Separating two types of XDP xmit */
+#define VETH_XDP_TX BIT(0)
+#define VETH_XDP_REDIR BIT(1)
+
+struct pcpu_vstats {
+ u64 packets;
+ u64 bytes;
+ struct u64_stats_sync syncp;
+};
+
+struct veth_rq {
+ struct napi_struct xdp_napi;
+ struct net_device *dev;
+ struct bpf_prog __rcu *xdp_prog;
+ struct xdp_mem_info xdp_mem;
+ bool rx_notify_masked;
+ struct ptr_ring xdp_ring;
+ struct xdp_rxq_info xdp_rxq;
+};
+
+struct veth_priv {
+ struct net_device __rcu *peer;
+ atomic64_t dropped;
+ struct bpf_prog *_xdp_prog;
+ struct veth_rq *rq;
+ unsigned int requested_headroom;
+};
+
+/*
+ * ethtool interface
+ */
+
+static struct {
+ const char string[ETH_GSTRING_LEN];
+} ethtool_stats_keys[] = {
+ { "peer_ifindex" },
+};
+
+static int veth_get_link_ksettings(struct net_device *dev,
+ struct ethtool_link_ksettings *cmd)
+{
+ cmd->base.speed = SPEED_10000;
+ cmd->base.duplex = DUPLEX_FULL;
+ cmd->base.port = PORT_TP;
+ cmd->base.autoneg = AUTONEG_DISABLE;
+ return 0;
+}
+
+static void veth_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
+{
+ strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
+ strlcpy(info->version, DRV_VERSION, sizeof(info->version));
+}
+
+static void veth_get_strings(struct net_device *dev, u32 stringset, u8 *buf)
+{
+ switch(stringset) {
+ case ETH_SS_STATS:
+ memcpy(buf, ðtool_stats_keys, sizeof(ethtool_stats_keys));
+ break;
+ }
+}
+
+static int veth_get_sset_count(struct net_device *dev, int sset)
+{
+ switch (sset) {
+ case ETH_SS_STATS:
+ return ARRAY_SIZE(ethtool_stats_keys);
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+static void veth_get_ethtool_stats(struct net_device *dev,
+ struct ethtool_stats *stats, u64 *data)
+{
+ struct veth_priv *priv = netdev_priv(dev);
+ struct net_device *peer = rtnl_dereference(priv->peer);
+
+ data[0] = peer ? peer->ifindex : 0;
+}
+
+static const struct ethtool_ops veth_ethtool_ops = {
+ .get_drvinfo = veth_get_drvinfo,
+ .get_link = ethtool_op_get_link,
+ .get_strings = veth_get_strings,
+ .get_sset_count = veth_get_sset_count,
+ .get_ethtool_stats = veth_get_ethtool_stats,
+ .get_link_ksettings = veth_get_link_ksettings,
+};
+
+/* general routines */
+
+static bool veth_is_xdp_frame(void *ptr)
+{
+ return (unsigned long)ptr & VETH_XDP_FLAG;
+}
+
+static void *veth_ptr_to_xdp(void *ptr)
+{
+ return (void *)((unsigned long)ptr & ~VETH_XDP_FLAG);
+}
+
+static void *veth_xdp_to_ptr(void *ptr)
+{
+ return (void *)((unsigned long)ptr | VETH_XDP_FLAG);
+}
+
+static void veth_ptr_free(void *ptr)
+{
+ if (veth_is_xdp_frame(ptr))
+ xdp_return_frame(veth_ptr_to_xdp(ptr));
+ else
+ kfree_skb(ptr);
+}
+
+static void __veth_xdp_flush(struct veth_rq *rq)
+{
+ /* Write ptr_ring before reading rx_notify_masked */
+ smp_mb();
+ if (!rq->rx_notify_masked) {
+ rq->rx_notify_masked = true;
+ napi_schedule(&rq->xdp_napi);
+ }
+}
+
+static int veth_xdp_rx(struct veth_rq *rq, struct sk_buff *skb)
+{
+ if (unlikely(ptr_ring_produce(&rq->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,
+ struct veth_rq *rq, bool xdp)
+{
+ return __dev_forward_skb(dev, skb) ?: xdp ?
+ veth_xdp_rx(rq, 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 veth_rq *rq = NULL;
+ struct net_device *rcv;
+ int length = skb->len;
+ bool rcv_xdp = false;
+ int rxq;
+
+ rcu_read_lock();
+ rcv = rcu_dereference(priv->peer);
+ if (unlikely(!rcv)) {
+ kfree_skb(skb);
+ goto drop;
+ }
+
+ rcv_priv = netdev_priv(rcv);
+ rxq = skb_get_queue_mapping(skb);
+ if (rxq < rcv->real_num_rx_queues) {
+ rq = &rcv_priv->rq[rxq];
+ rcv_xdp = rcu_access_pointer(rq->xdp_prog);
+ if (rcv_xdp)
+ skb_record_rx_queue(skb, rxq);
+ }
+
+ if (likely(veth_forward_skb(rcv, skb, rq, rcv_xdp) == NET_RX_SUCCESS)) {
+ struct pcpu_vstats *stats = this_cpu_ptr(dev->vstats);
+
+ u64_stats_update_begin(&stats->syncp);
+ stats->bytes += length;
+ stats->packets++;
+ u64_stats_update_end(&stats->syncp);
+ } else {
+drop:
+ atomic64_inc(&priv->dropped);
+ }
+
+ if (rcv_xdp)
+ __veth_xdp_flush(rq);
+
+ rcu_read_unlock();
+
+ return NETDEV_TX_OK;
+}
+
+static u64 veth_stats_one(struct pcpu_vstats *result, struct net_device *dev)
+{
+ struct veth_priv *priv = netdev_priv(dev);
+ int cpu;
+
+ result->packets = 0;
+ result->bytes = 0;
+ for_each_possible_cpu(cpu) {
+ struct pcpu_vstats *stats = per_cpu_ptr(dev->vstats, cpu);
+ u64 packets, bytes;
+ unsigned int start;
+
+ do {
+ start = u64_stats_fetch_begin_irq(&stats->syncp);
+ packets = stats->packets;
+ bytes = stats->bytes;
+ } while (u64_stats_fetch_retry_irq(&stats->syncp, start));
+ result->packets += packets;
+ result->bytes += bytes;
+ }
+ return atomic64_read(&priv->dropped);
+}
+
+static void veth_get_stats64(struct net_device *dev,
+ struct rtnl_link_stats64 *tot)
+{
+ struct veth_priv *priv = netdev_priv(dev);
+ struct net_device *peer;
+ struct pcpu_vstats one;
+
+ tot->tx_dropped = veth_stats_one(&one, dev);
+ tot->tx_bytes = one.bytes;
+ tot->tx_packets = one.packets;
+
+ rcu_read_lock();
+ peer = rcu_dereference(priv->peer);
+ if (peer) {
+ tot->rx_dropped = veth_stats_one(&one, peer);
+ tot->rx_bytes = one.bytes;
+ tot->rx_packets = one.packets;
+ }
+ rcu_read_unlock();
+}
+
+/* fake multicast ability */
+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 int veth_select_rxq(struct net_device *dev)
+{
+ return smp_processor_id() % dev->real_num_rx_queues;
+}
+
+static int veth_xdp_xmit(struct net_device *dev, int n,
+ struct xdp_frame **frames, u32 flags)
+{
+ struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
+ struct net_device *rcv;
+ unsigned int max_len;
+ struct veth_rq *rq;
+ int i, drops = 0;
+
+ if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
+ return -EINVAL;
+
+ rcv = rcu_dereference(priv->peer);
+ if (unlikely(!rcv))
+ return -ENXIO;
+
+ rcv_priv = netdev_priv(rcv);
+ rq = &rcv_priv->rq[veth_select_rxq(rcv)];
+ /* Non-NULL xdp_prog ensures that xdp_ring is initialized on receive
+ * side. This means an XDP program is loaded on the peer and the peer
+ * device is up.
+ */
+ if (!rcu_access_pointer(rq->xdp_prog))
+ return -ENXIO;
+
+ max_len = rcv->mtu + rcv->hard_header_len + VLAN_HLEN;
+
+ spin_lock(&rq->xdp_ring.producer_lock);
+ for (i = 0; i < n; i++) {
+ struct xdp_frame *frame = frames[i];
+ void *ptr = veth_xdp_to_ptr(frame);
+
+ if (unlikely(frame->len > max_len ||
+ __ptr_ring_produce(&rq->xdp_ring, ptr))) {
+ xdp_return_frame_rx_napi(frame);
+ drops++;
+ }
+ }
+ spin_unlock(&rq->xdp_ring.producer_lock);
+
+ if (flags & XDP_XMIT_FLUSH)
+ __veth_xdp_flush(rq);
+
+ return n - drops;
+}
+
+static void veth_xdp_flush(struct net_device *dev)
+{
+ struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
+ struct net_device *rcv;
+ struct veth_rq *rq;
+
+ rcu_read_lock();
+ rcv = rcu_dereference(priv->peer);
+ if (unlikely(!rcv))
+ goto out;
+
+ rcv_priv = netdev_priv(rcv);
+ rq = &rcv_priv->rq[veth_select_rxq(rcv)];
+ /* xdp_ring is initialized on receive side? */
+ if (unlikely(!rcu_access_pointer(rq->xdp_prog)))
+ goto out;
+
+ __veth_xdp_flush(rq);
+out:
+ rcu_read_unlock();
+}
+
+static int veth_xdp_tx(struct net_device *dev, struct xdp_buff *xdp)
+{
+ struct xdp_frame *frame = convert_to_xdp_frame(xdp);
+
+ if (unlikely(!frame))
+ return -EOVERFLOW;
+
+ return veth_xdp_xmit(dev, 1, &frame, 0);
+}
+
+static struct sk_buff *veth_xdp_rcv_one(struct veth_rq *rq,
+ struct xdp_frame *frame,
+ unsigned int *xdp_xmit)
+{
+ void *hard_start = frame->data - frame->headroom;
+ void *head = hard_start - sizeof(struct xdp_frame);
+ int len = frame->len, delta = 0;
+ struct xdp_frame orig_frame;
+ struct bpf_prog *xdp_prog;
+ unsigned int headroom;
+ struct sk_buff *skb;
+
+ rcu_read_lock();
+ xdp_prog = rcu_dereference(rq->xdp_prog);
+ if (likely(xdp_prog)) {
+ struct xdp_buff xdp;
+ u32 act;
+
+ xdp.data_hard_start = hard_start;
+ xdp.data = frame->data;
+ xdp.data_end = frame->data + frame->len;
+ xdp.data_meta = frame->data - frame->metasize;
+ xdp.rxq = &rq->xdp_rxq;
+
+ act = bpf_prog_run_xdp(xdp_prog, &xdp);
+
+ switch (act) {
+ case XDP_PASS:
+ delta = frame->data - xdp.data;
+ len = xdp.data_end - xdp.data;
+ break;
+ case XDP_TX:
+ orig_frame = *frame;
+ xdp.data_hard_start = head;
+ xdp.rxq->mem = frame->mem;
+ if (unlikely(veth_xdp_tx(rq->dev, &xdp) < 0)) {
+ trace_xdp_exception(rq->dev, xdp_prog, act);
+ frame = &orig_frame;
+ goto err_xdp;
+ }
+ *xdp_xmit |= VETH_XDP_TX;
+ rcu_read_unlock();
+ goto xdp_xmit;
+ case XDP_REDIRECT:
+ orig_frame = *frame;
+ xdp.data_hard_start = head;
+ xdp.rxq->mem = frame->mem;
+ if (xdp_do_redirect(rq->dev, &xdp, xdp_prog)) {
+ frame = &orig_frame;
+ goto err_xdp;
+ }
+ *xdp_xmit |= VETH_XDP_REDIR;
+ rcu_read_unlock();
+ goto xdp_xmit;
+ default:
+ bpf_warn_invalid_xdp_action(act);
+ case XDP_ABORTED:
+ trace_xdp_exception(rq->dev, xdp_prog, act);
+ case XDP_DROP:
+ goto err_xdp;
+ }
+ }
+ rcu_read_unlock();
+
+ headroom = sizeof(struct xdp_frame) + frame->headroom - delta;
+ skb = veth_build_skb(head, headroom, len, 0);
+ if (!skb) {
+ xdp_return_frame(frame);
+ goto err;
+ }
+
+ xdp_scrub_frame(frame);
+ skb->protocol = eth_type_trans(skb, rq->dev);
+err:
+ return skb;
+err_xdp:
+ rcu_read_unlock();
+ xdp_return_frame(frame);
+xdp_xmit:
+ return NULL;
+}
+
+static struct sk_buff *veth_xdp_rcv_skb(struct veth_rq *rq, struct sk_buff *skb,
+ unsigned int *xdp_xmit)
+{
+ 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;
+
+ skb_orphan(skb);
+
+ rcu_read_lock();
+ xdp_prog = rcu_dereference(rq->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);
+ 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 = &rq->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;
+ case XDP_TX:
+ get_page(virt_to_page(xdp.data));
+ consume_skb(skb);
+ xdp.rxq->mem = rq->xdp_mem;
+ if (unlikely(veth_xdp_tx(rq->dev, &xdp) < 0)) {
+ trace_xdp_exception(rq->dev, xdp_prog, act);
+ goto err_xdp;
+ }
+ *xdp_xmit |= VETH_XDP_TX;
+ rcu_read_unlock();
+ goto xdp_xmit;
+ case XDP_REDIRECT:
+ get_page(virt_to_page(xdp.data));
+ consume_skb(skb);
+ xdp.rxq->mem = rq->xdp_mem;
+ if (xdp_do_redirect(rq->dev, &xdp, xdp_prog))
+ goto err_xdp;
+ *xdp_xmit |= VETH_XDP_REDIR;
+ rcu_read_unlock();
+ goto xdp_xmit;
+ default:
+ bpf_warn_invalid_xdp_action(act);
+ case XDP_ABORTED:
+ trace_xdp_exception(rq->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, rq->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;
+err_xdp:
+ rcu_read_unlock();
+ page_frag_free(xdp.data);
+xdp_xmit:
+ return NULL;
+}
+
+static int veth_xdp_rcv(struct veth_rq *rq, int budget, unsigned int *xdp_xmit)
+{
+ int i, done = 0;
+
+ for (i = 0; i < budget; i++) {
+ void *ptr = __ptr_ring_consume(&rq->xdp_ring);
+ struct sk_buff *skb;
+
+ if (!ptr)
+ break;
+
+ if (veth_is_xdp_frame(ptr)) {
+ skb = veth_xdp_rcv_one(rq, veth_ptr_to_xdp(ptr),
+ xdp_xmit);
+ } else {
+ skb = veth_xdp_rcv_skb(rq, ptr, xdp_xmit);
+ }
+
+ if (skb)
+ napi_gro_receive(&rq->xdp_napi, skb);
+
+ done++;
+ }
+
+ return done;
+}
+
+static int veth_poll(struct napi_struct *napi, int budget)
+{
+ struct veth_rq *rq =
+ container_of(napi, struct veth_rq, xdp_napi);
+ unsigned int xdp_xmit = 0;
+ int done;
+
+ xdp_set_return_frame_no_direct();
+ done = veth_xdp_rcv(rq, budget, &xdp_xmit);
+
+ if (done < budget && napi_complete_done(napi, done)) {
+ /* Write rx_notify_masked before reading ptr_ring */
+ smp_store_mb(rq->rx_notify_masked, false);
+ if (unlikely(!__ptr_ring_empty(&rq->xdp_ring))) {
+ rq->rx_notify_masked = true;
+ napi_schedule(&rq->xdp_napi);
+ }
+ }
+
+ if (xdp_xmit & VETH_XDP_TX)
+ veth_xdp_flush(rq->dev);
+ if (xdp_xmit & VETH_XDP_REDIR)
+ xdp_do_flush_map();
+ xdp_clear_return_frame_no_direct();
+
+ return done;
+}
+
+static int veth_napi_add(struct net_device *dev)
+{
+ struct veth_priv *priv = netdev_priv(dev);
+ int err, i;
+
+ for (i = 0; i < dev->real_num_rx_queues; i++) {
+ struct veth_rq *rq = &priv->rq[i];
+
+ err = ptr_ring_init(&rq->xdp_ring, VETH_RING_SIZE, GFP_KERNEL);
+ if (err)
+ goto err_xdp_ring;
+ }
+
+ for (i = 0; i < dev->real_num_rx_queues; i++) {
+ struct veth_rq *rq = &priv->rq[i];
+
+ netif_napi_add(dev, &rq->xdp_napi, veth_poll, NAPI_POLL_WEIGHT);
+ napi_enable(&rq->xdp_napi);
+ }
+
+ return 0;
+err_xdp_ring:
+ for (i--; i >= 0; i--)
+ ptr_ring_cleanup(&priv->rq[i].xdp_ring, veth_ptr_free);
+
+ return err;
+}
+
+static void veth_napi_del(struct net_device *dev)
+{
+ struct veth_priv *priv = netdev_priv(dev);
+ int i;
+
+ for (i = 0; i < dev->real_num_rx_queues; i++) {
+ struct veth_rq *rq = &priv->rq[i];
+
+ napi_disable(&rq->xdp_napi);
+ napi_hash_del(&rq->xdp_napi);
+ }
+ synchronize_net();
+
+ for (i = 0; i < dev->real_num_rx_queues; i++) {
+ struct veth_rq *rq = &priv->rq[i];
+
+ netif_napi_del(&rq->xdp_napi);
+ rq->rx_notify_masked = false;
+ ptr_ring_cleanup(&rq->xdp_ring, veth_ptr_free);
+ }
+}
+
+static int veth_enable_xdp(struct net_device *dev)
+{
+ struct veth_priv *priv = netdev_priv(dev);
+ int err, i;
+
+ if (!xdp_rxq_info_is_reg(&priv->rq[0].xdp_rxq)) {
+ for (i = 0; i < dev->real_num_rx_queues; i++) {
+ struct veth_rq *rq = &priv->rq[i];
+
+ err = xdp_rxq_info_reg(&rq->xdp_rxq, dev, i);
+ if (err < 0)
+ goto err_rxq_reg;
+
+ err = xdp_rxq_info_reg_mem_model(&rq->xdp_rxq,
+ MEM_TYPE_PAGE_SHARED,
+ NULL);
+ if (err < 0)
+ goto err_reg_mem;
+
+ /* Save original mem info as it can be overwritten */
+ rq->xdp_mem = rq->xdp_rxq.mem;
+ }
+
+ err = veth_napi_add(dev);
+ if (err)
+ goto err_rxq_reg;
+ }
+
+ for (i = 0; i < dev->real_num_rx_queues; i++)
+ rcu_assign_pointer(priv->rq[i].xdp_prog, priv->_xdp_prog);
+
+ return 0;
+err_reg_mem:
+ xdp_rxq_info_unreg(&priv->rq[i].xdp_rxq);
+err_rxq_reg:
+ for (i--; i >= 0; i--)
+ xdp_rxq_info_unreg(&priv->rq[i].xdp_rxq);
+
+ return err;
+}
+
+static void veth_disable_xdp(struct net_device *dev)
+{
+ struct veth_priv *priv = netdev_priv(dev);
+ int i;
+
+ for (i = 0; i < dev->real_num_rx_queues; i++)
+ rcu_assign_pointer(priv->rq[i].xdp_prog, NULL);
+ veth_napi_del(dev);
+ for (i = 0; i < dev->real_num_rx_queues; i++) {
+ struct veth_rq *rq = &priv->rq[i];
+
+ rq->xdp_rxq.mem = rq->xdp_mem;
+ xdp_rxq_info_unreg(&rq->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;
+}
+
+static int veth_close(struct net_device *dev)
+{
+ struct veth_priv *priv = netdev_priv(dev);
+ struct net_device *peer = rtnl_dereference(priv->peer);
+
+ netif_carrier_off(dev);
+ if (peer)
+ netif_carrier_off(peer);
+
+ if (priv->_xdp_prog)
+ veth_disable_xdp(dev);
+
+ return 0;
+}
+
+static int is_valid_veth_mtu(int mtu)
+{
+ return mtu >= ETH_MIN_MTU && mtu <= ETH_MAX_MTU;
+}
+
+static int veth_alloc_queues(struct net_device *dev)
+{
+ struct veth_priv *priv = netdev_priv(dev);
+ int i;
+
+ priv->rq = kcalloc(dev->num_rx_queues, sizeof(*priv->rq), GFP_KERNEL);
+ if (!priv->rq)
+ return -ENOMEM;
+
+ for (i = 0; i < dev->num_rx_queues; i++)
+ priv->rq[i].dev = dev;
+
+ return 0;
+}
+
+static void veth_free_queues(struct net_device *dev)
+{
+ struct veth_priv *priv = netdev_priv(dev);
+
+ kfree(priv->rq);
+}
+
+static int veth_dev_init(struct net_device *dev)
+{
+ int err;
+
+ dev->vstats = netdev_alloc_pcpu_stats(struct pcpu_vstats);
+ if (!dev->vstats)
+ return -ENOMEM;
+
+ err = veth_alloc_queues(dev);
+ if (err) {
+ free_percpu(dev->vstats);
+ return err;
+ }
+
+ return 0;
+}
+
+static void veth_dev_free(struct net_device *dev)
+{
+ veth_free_queues(dev);
+ free_percpu(dev->vstats);
+}
+
+#ifdef CONFIG_NET_POLL_CONTROLLER
+static void veth_poll_controller(struct net_device *dev)
+{
+ /* veth only receives frames when its peer sends one
+ * 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.
+ *
+ * We need this though so netpoll recognizes us as an interface that
+ * supports polling, which enables bridge devices in virt setups to
+ * still use netconsole
+ */
+}
+#endif /* CONFIG_NET_POLL_CONTROLLER */
+
+static int veth_get_iflink(const struct net_device *dev)
+{
+ struct veth_priv *priv = netdev_priv(dev);
+ struct net_device *peer;
+ int iflink;
+
+ rcu_read_lock();
+ peer = rcu_dereference(priv->peer);
+ iflink = peer ? peer->ifindex : 0;
+ rcu_read_unlock();
+
+ return iflink;
+}
+
+static netdev_features_t veth_fix_features(struct net_device *dev,
+ netdev_features_t features)
+{
+ struct veth_priv *priv = netdev_priv(dev);
+ struct net_device *peer;
+
+ peer = rtnl_dereference(priv->peer);
+ if (peer) {
+ struct veth_priv *peer_priv = netdev_priv(peer);
+
+ if (peer_priv->_xdp_prog)
+ features &= ~NETIF_F_GSO_SOFTWARE;
+ }
+
+ return features;
+}
+
+static void veth_set_rx_headroom(struct net_device *dev, int new_hr)
+{
+ struct veth_priv *peer_priv, *priv = netdev_priv(dev);
+ struct net_device *peer;
+
+ if (new_hr < 0)
+ new_hr = 0;
+
+ rcu_read_lock();
+ peer = rcu_dereference(priv->peer);
+ if (unlikely(!peer))
+ goto out;
+
+ peer_priv = netdev_priv(peer);
+ priv->requested_headroom = new_hr;
+ new_hr = max(priv->requested_headroom, peer_priv->requested_headroom);
+ dev->needed_headroom = new_hr;
+ peer->needed_headroom = new_hr;
+
+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;
+ unsigned int max_mtu;
+ 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;
+ }
+
+ max_mtu = PAGE_SIZE - VETH_XDP_HEADROOM -
+ peer->hard_header_len -
+ SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
+ if (peer->mtu > max_mtu) {
+ NL_SET_ERR_MSG_MOD(extack, "Peer MTU is too large to set XDP");
+ err = -ERANGE;
+ goto err;
+ }
+
+ if (dev->real_num_rx_queues < peer->real_num_tx_queues) {
+ NL_SET_ERR_MSG_MOD(extack, "XDP expects number of rx queues not less than peer tx queues");
+ err = -ENOSPC;
+ 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) {
+ peer->hw_features &= ~NETIF_F_GSO_SOFTWARE;
+ peer->max_mtu = max_mtu;
+ }
+ }
+
+ if (old_prog) {
+ if (!prog) {
+ if (dev->flags & IFF_UP)
+ veth_disable_xdp(dev);
+
+ if (peer) {
+ peer->hw_features |= NETIF_F_GSO_SOFTWARE;
+ peer->max_mtu = ETH_MAX_MTU;
+ }
+ }
+ bpf_prog_put(old_prog);
+ }
+
+ if ((!!old_prog ^ !!prog) && peer)
+ netdev_update_features(peer);
+
+ 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_stop = veth_close,
+ .ndo_start_xmit = veth_xmit,
+ .ndo_get_stats64 = veth_get_stats64,
+ .ndo_set_rx_mode = veth_set_multicast_list,
+ .ndo_set_mac_address = eth_mac_addr,
+#ifdef CONFIG_NET_POLL_CONTROLLER
+ .ndo_poll_controller = veth_poll_controller,
+#endif
+ .ndo_get_iflink = veth_get_iflink,
+ .ndo_fix_features = veth_fix_features,
+ .ndo_features_check = passthru_features_check,
+ .ndo_set_rx_headroom = veth_set_rx_headroom,
+ .ndo_bpf = veth_xdp,
+ .ndo_xdp_xmit = veth_xdp_xmit,
+};
+
+#define VETH_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HW_CSUM | \
+ NETIF_F_RXCSUM | NETIF_F_SCTP_CRC | NETIF_F_HIGHDMA | \
+ NETIF_F_GSO_SOFTWARE | NETIF_F_GSO_ENCAP_ALL | \
+ NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX | \
+ NETIF_F_HW_VLAN_STAG_TX | NETIF_F_HW_VLAN_STAG_RX )
+
+static void veth_setup(struct net_device *dev)
+{
+ ether_setup(dev);
+
+ dev->priv_flags &= ~IFF_TX_SKB_SHARING;
+ dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
+ dev->priv_flags |= IFF_NO_QUEUE;
+ dev->priv_flags |= IFF_PHONY_HEADROOM;
+
+ dev->netdev_ops = &veth_netdev_ops;
+ dev->ethtool_ops = &veth_ethtool_ops;
+ dev->features |= NETIF_F_LLTX;
+ dev->features |= VETH_FEATURES;
+ dev->vlan_features = dev->features &
+ ~(NETIF_F_HW_VLAN_CTAG_TX |
+ NETIF_F_HW_VLAN_STAG_TX |
+ NETIF_F_HW_VLAN_CTAG_RX |
+ NETIF_F_HW_VLAN_STAG_RX);
+ dev->needs_free_netdev = true;
+ dev->priv_destructor = veth_dev_free;
+ dev->max_mtu = ETH_MAX_MTU;
+
+ dev->hw_features = VETH_FEATURES;
+ dev->hw_enc_features = VETH_FEATURES;
+ dev->mpls_features = NETIF_F_HW_CSUM | NETIF_F_GSO_SOFTWARE;
+}
+
+/*
+ * netlink interface
+ */
+
+static int veth_validate(struct nlattr *tb[], struct nlattr *data[],
+ struct netlink_ext_ack *extack)
+{
+ if (tb[IFLA_ADDRESS]) {
+ if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
+ return -EINVAL;
+ if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
+ return -EADDRNOTAVAIL;
+ }
+ if (tb[IFLA_MTU]) {
+ if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU])))
+ return -EINVAL;
+ }
+ return 0;
+}
+
+static struct rtnl_link_ops veth_link_ops;
+
+static int veth_newlink(struct net *src_net, struct net_device *dev,
+ struct nlattr *tb[], struct nlattr *data[],
+ struct netlink_ext_ack *extack)
+{
+ int err;
+ struct net_device *peer;
+ struct veth_priv *priv;
+ char ifname[IFNAMSIZ];
+ struct nlattr *peer_tb[IFLA_MAX + 1], **tbp;
+ unsigned char name_assign_type;
+ struct ifinfomsg *ifmp;
+ struct net *net;
+
+ /*
+ * create and register peer first
+ */
+ if (data != NULL && data[VETH_INFO_PEER] != NULL) {
+ struct nlattr *nla_peer;
+
+ nla_peer = data[VETH_INFO_PEER];
+ ifmp = nla_data(nla_peer);
+ err = rtnl_nla_parse_ifla(peer_tb,
+ nla_data(nla_peer) + sizeof(struct ifinfomsg),
+ nla_len(nla_peer) - sizeof(struct ifinfomsg),
+ NULL);
+ if (err < 0)
+ return err;
+
+ err = veth_validate(peer_tb, NULL, extack);
+ if (err < 0)
+ return err;
+
+ tbp = peer_tb;
+ } else {
+ ifmp = NULL;
+ tbp = tb;
+ }
+
+ if (ifmp && tbp[IFLA_IFNAME]) {
+ nla_strlcpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);
+ name_assign_type = NET_NAME_USER;
+ } else {
+ snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");
+ name_assign_type = NET_NAME_ENUM;
+ }
+
+ net = rtnl_link_get_net(src_net, tbp);
+ if (IS_ERR(net))
+ return PTR_ERR(net);
+
+ peer = rtnl_create_link(net, ifname, name_assign_type,
+ &veth_link_ops, tbp);
+ if (IS_ERR(peer)) {
+ put_net(net);
+ return PTR_ERR(peer);
+ }
+
+ if (!ifmp || !tbp[IFLA_ADDRESS])
+ eth_hw_addr_random(peer);
+
+ if (ifmp && (dev->ifindex != 0))
+ peer->ifindex = ifmp->ifi_index;
+
+ peer->gso_max_size = dev->gso_max_size;
+ peer->gso_max_segs = dev->gso_max_segs;
+
+ err = register_netdevice(peer);
+ put_net(net);
+ net = NULL;
+ if (err < 0)
+ goto err_register_peer;
+
+ netif_carrier_off(peer);
+
+ err = rtnl_configure_link(peer, ifmp);
+ if (err < 0)
+ goto err_configure_peer;
+
+ /*
+ * register dev last
+ *
+ * note, that since we've registered new device the dev's name
+ * should be re-allocated
+ */
+
+ if (tb[IFLA_ADDRESS] == NULL)
+ eth_hw_addr_random(dev);
+
+ if (tb[IFLA_IFNAME])
+ nla_strlcpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);
+ else
+ snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d");
+
+ err = register_netdevice(dev);
+ if (err < 0)
+ goto err_register_dev;
+
+ netif_carrier_off(dev);
+
+ /*
+ * tie the deviced together
+ */
+
+ priv = netdev_priv(dev);
+ rcu_assign_pointer(priv->peer, peer);
+
+ priv = netdev_priv(peer);
+ rcu_assign_pointer(priv->peer, dev);
+
+ return 0;
+
+err_register_dev:
+ /* nothing to do */
+err_configure_peer:
+ unregister_netdevice(peer);
+ return err;
+
+err_register_peer:
+ free_netdev(peer);
+ return err;
+}
+
+static void veth_dellink(struct net_device *dev, struct list_head *head)
+{
+ struct veth_priv *priv;
+ struct net_device *peer;
+
+ priv = netdev_priv(dev);
+ peer = rtnl_dereference(priv->peer);
+
+ /* Note : dellink() is called from default_device_exit_batch(),
+ * before a rcu_synchronize() point. The devices are guaranteed
+ * not being freed before one RCU grace period.
+ */
+ RCU_INIT_POINTER(priv->peer, NULL);
+ unregister_netdevice_queue(dev, head);
+
+ if (peer) {
+ priv = netdev_priv(peer);
+ RCU_INIT_POINTER(priv->peer, NULL);
+ unregister_netdevice_queue(peer, head);
+ }
+}
+
+static const struct nla_policy veth_policy[VETH_INFO_MAX + 1] = {
+ [VETH_INFO_PEER] = { .len = sizeof(struct ifinfomsg) },
+};
+
+static struct net *veth_get_link_net(const struct net_device *dev)
+{
+ struct veth_priv *priv = netdev_priv(dev);
+ struct net_device *peer = rtnl_dereference(priv->peer);
+
+ return peer ? dev_net(peer) : dev_net(dev);
+}
+
+static struct rtnl_link_ops veth_link_ops = {
+ .kind = DRV_NAME,
+ .priv_size = sizeof(struct veth_priv),
+ .setup = veth_setup,
+ .validate = veth_validate,
+ .newlink = veth_newlink,
+ .dellink = veth_dellink,
+ .policy = veth_policy,
+ .maxtype = VETH_INFO_MAX,
+ .get_link_net = veth_get_link_net,
+};
+
+/*
+ * init/fini
+ */
+
+static __init int veth_init(void)
+{
+ return rtnl_link_register(&veth_link_ops);
+}
+
+static __exit void veth_exit(void)
+{
+ rtnl_link_unregister(&veth_link_ops);
+}
+
+module_init(veth_init);
+module_exit(veth_exit);
+
+MODULE_DESCRIPTION("Virtual Ethernet Tunnel");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS_RTNL_LINK(DRV_NAME);