diff options
Diffstat (limited to 'drivers/net/veth.c')
| -rw-r--r-- | drivers/net/veth.c | 1265 |
1 files changed, 1265 insertions, 0 deletions
diff --git a/drivers/net/veth.c b/drivers/net/veth.c new file mode 100644 index 000000000..ea999a663 --- /dev/null +++ b/drivers/net/veth.c @@ -0,0 +1,1265 @@ +/* + * 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 (!READ_ONCE(rq->rx_notify_masked) && + napi_schedule_prep(&rq->xdp_napi)) { + WRITE_ONCE(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) || !pskb_may_pull(skb, ETH_HLEN)) { + 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 (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; + int len = frame->len, delta = 0; + struct xdp_frame orig_frame; + struct bpf_prog *xdp_prog; + unsigned int headroom; + struct sk_buff *skb; + + /* bpf_xdp_adjust_head() assures BPF cannot access xdp_frame area */ + hard_start -= sizeof(struct xdp_frame); + + 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.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.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(hard_start, 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))) { + if (napi_schedule_prep(&rq->xdp_napi)) { + WRITE_ONCE(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); |