// SPDX-License-Identifier: GPL-2.0-only /* * 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> #include <linux/net_tstamp.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) #define VETH_XDP_TX_BULK_SIZE 16 #define VETH_XDP_BATCH 16 struct veth_stats { u64 rx_drops; /* xdp */ u64 xdp_packets; u64 xdp_bytes; u64 xdp_redirect; u64 xdp_drops; u64 xdp_tx; u64 xdp_tx_err; u64 peer_tq_xdp_xmit; u64 peer_tq_xdp_xmit_err; }; struct veth_rq_stats { struct veth_stats vs; struct u64_stats_sync syncp; }; struct veth_rq { struct napi_struct xdp_napi; struct napi_struct __rcu *napi; /* points to xdp_napi when the latter is initialized */ struct net_device *dev; struct bpf_prog __rcu *xdp_prog; struct xdp_mem_info xdp_mem; struct veth_rq_stats stats; 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; }; struct veth_xdp_tx_bq { struct xdp_frame *q[VETH_XDP_TX_BULK_SIZE]; unsigned int count; }; /* * ethtool interface */ struct veth_q_stat_desc { char desc[ETH_GSTRING_LEN]; size_t offset; }; #define VETH_RQ_STAT(m) offsetof(struct veth_stats, m) static const struct veth_q_stat_desc veth_rq_stats_desc[] = { { "xdp_packets", VETH_RQ_STAT(xdp_packets) }, { "xdp_bytes", VETH_RQ_STAT(xdp_bytes) }, { "drops", VETH_RQ_STAT(rx_drops) }, { "xdp_redirect", VETH_RQ_STAT(xdp_redirect) }, { "xdp_drops", VETH_RQ_STAT(xdp_drops) }, { "xdp_tx", VETH_RQ_STAT(xdp_tx) }, { "xdp_tx_errors", VETH_RQ_STAT(xdp_tx_err) }, }; #define VETH_RQ_STATS_LEN ARRAY_SIZE(veth_rq_stats_desc) static const struct veth_q_stat_desc veth_tq_stats_desc[] = { { "xdp_xmit", VETH_RQ_STAT(peer_tq_xdp_xmit) }, { "xdp_xmit_errors", VETH_RQ_STAT(peer_tq_xdp_xmit_err) }, }; #define VETH_TQ_STATS_LEN ARRAY_SIZE(veth_tq_stats_desc) 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) { u8 *p = buf; int i, j; switch(stringset) { case ETH_SS_STATS: memcpy(p, ðtool_stats_keys, sizeof(ethtool_stats_keys)); p += sizeof(ethtool_stats_keys); for (i = 0; i < dev->real_num_rx_queues; i++) for (j = 0; j < VETH_RQ_STATS_LEN; j++) ethtool_sprintf(&p, "rx_queue_%u_%.18s", i, veth_rq_stats_desc[j].desc); for (i = 0; i < dev->real_num_tx_queues; i++) for (j = 0; j < VETH_TQ_STATS_LEN; j++) ethtool_sprintf(&p, "tx_queue_%u_%.18s", i, veth_tq_stats_desc[j].desc); 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) + VETH_RQ_STATS_LEN * dev->real_num_rx_queues + VETH_TQ_STATS_LEN * dev->real_num_tx_queues; default: return -EOPNOTSUPP; } } static void veth_get_ethtool_stats(struct net_device *dev, struct ethtool_stats *stats, u64 *data) { struct veth_priv *rcv_priv, *priv = netdev_priv(dev); struct net_device *peer = rtnl_dereference(priv->peer); int i, j, idx; data[0] = peer ? peer->ifindex : 0; idx = 1; for (i = 0; i < dev->real_num_rx_queues; i++) { const struct veth_rq_stats *rq_stats = &priv->rq[i].stats; const void *stats_base = (void *)&rq_stats->vs; unsigned int start; size_t offset; do { start = u64_stats_fetch_begin_irq(&rq_stats->syncp); for (j = 0; j < VETH_RQ_STATS_LEN; j++) { offset = veth_rq_stats_desc[j].offset; data[idx + j] = *(u64 *)(stats_base + offset); } } while (u64_stats_fetch_retry_irq(&rq_stats->syncp, start)); idx += VETH_RQ_STATS_LEN; } if (!peer) return; rcv_priv = netdev_priv(peer); for (i = 0; i < peer->real_num_rx_queues; i++) { const struct veth_rq_stats *rq_stats = &rcv_priv->rq[i].stats; const void *base = (void *)&rq_stats->vs; unsigned int start, tx_idx = idx; size_t offset; tx_idx += (i % dev->real_num_tx_queues) * VETH_TQ_STATS_LEN; do { start = u64_stats_fetch_begin_irq(&rq_stats->syncp); for (j = 0; j < VETH_TQ_STATS_LEN; j++) { offset = veth_tq_stats_desc[j].offset; data[tx_idx + j] += *(u64 *)(base + offset); } } while (u64_stats_fetch_retry_irq(&rq_stats->syncp, start)); } } static void veth_get_channels(struct net_device *dev, struct ethtool_channels *channels) { channels->tx_count = dev->real_num_tx_queues; channels->rx_count = dev->real_num_rx_queues; channels->max_tx = dev->num_tx_queues; channels->max_rx = dev->num_rx_queues; } static int veth_set_channels(struct net_device *dev, struct ethtool_channels *ch); 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, .get_ts_info = ethtool_op_get_ts_info, .get_channels = veth_get_channels, .set_channels = veth_set_channels, }; /* general routines */ static bool veth_is_xdp_frame(void *ptr) { return (unsigned long)ptr & VETH_XDP_FLAG; } static struct xdp_frame *veth_ptr_to_xdp(void *ptr) { return (void *)((unsigned long)ptr & ~VETH_XDP_FLAG); } static void *veth_xdp_to_ptr(struct xdp_frame *xdp) { return (void *)((unsigned long)xdp | 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); } /* return true if the specified skb has chances of GRO aggregation * Don't strive for accuracy, but try to avoid GRO overhead in the most * common scenarios. * When XDP is enabled, all traffic is considered eligible, as the xmit * device has TSO off. * When TSO is enabled on the xmit device, we are likely interested only * in UDP aggregation, explicitly check for that if the skb is suspected * - the sock_wfree destructor is used by UDP, ICMP and XDP sockets - * to belong to locally generated UDP traffic. */ static bool veth_skb_is_eligible_for_gro(const struct net_device *dev, const struct net_device *rcv, const struct sk_buff *skb) { return !(dev->features & NETIF_F_ALL_TSO) || (skb->destructor == sock_wfree && rcv->features & (NETIF_F_GRO_FRAGLIST | NETIF_F_GRO_UDP_FWD)); } 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 use_napi = 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]; /* The napi pointer is available when an XDP program is * attached or when GRO is enabled * Don't bother with napi/GRO if the skb can't be aggregated */ use_napi = rcu_access_pointer(rq->napi) && veth_skb_is_eligible_for_gro(dev, rcv, skb); } skb_tx_timestamp(skb); if (likely(veth_forward_skb(rcv, skb, rq, use_napi) == NET_RX_SUCCESS)) { if (!use_napi) dev_lstats_add(dev, length); } else { drop: atomic64_inc(&priv->dropped); } if (use_napi) __veth_xdp_flush(rq); rcu_read_unlock(); return NETDEV_TX_OK; } static u64 veth_stats_tx(struct net_device *dev, u64 *packets, u64 *bytes) { struct veth_priv *priv = netdev_priv(dev); dev_lstats_read(dev, packets, bytes); return atomic64_read(&priv->dropped); } static void veth_stats_rx(struct veth_stats *result, struct net_device *dev) { struct veth_priv *priv = netdev_priv(dev); int i; result->peer_tq_xdp_xmit_err = 0; result->xdp_packets = 0; result->xdp_tx_err = 0; result->xdp_bytes = 0; result->rx_drops = 0; for (i = 0; i < dev->num_rx_queues; i++) { u64 packets, bytes, drops, xdp_tx_err, peer_tq_xdp_xmit_err; struct veth_rq_stats *stats = &priv->rq[i].stats; unsigned int start; do { start = u64_stats_fetch_begin_irq(&stats->syncp); peer_tq_xdp_xmit_err = stats->vs.peer_tq_xdp_xmit_err; xdp_tx_err = stats->vs.xdp_tx_err; packets = stats->vs.xdp_packets; bytes = stats->vs.xdp_bytes; drops = stats->vs.rx_drops; } while (u64_stats_fetch_retry_irq(&stats->syncp, start)); result->peer_tq_xdp_xmit_err += peer_tq_xdp_xmit_err; result->xdp_tx_err += xdp_tx_err; result->xdp_packets += packets; result->xdp_bytes += bytes; result->rx_drops += drops; } } 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 veth_stats rx; u64 packets, bytes; tot->tx_dropped = veth_stats_tx(dev, &packets, &bytes); tot->tx_bytes = bytes; tot->tx_packets = packets; veth_stats_rx(&rx, dev); tot->tx_dropped += rx.xdp_tx_err; tot->rx_dropped = rx.rx_drops + rx.peer_tq_xdp_xmit_err; tot->rx_bytes = rx.xdp_bytes; tot->rx_packets = rx.xdp_packets; rcu_read_lock(); peer = rcu_dereference(priv->peer); if (peer) { veth_stats_tx(peer, &packets, &bytes); tot->rx_bytes += bytes; tot->rx_packets += packets; veth_stats_rx(&rx, peer); tot->tx_dropped += rx.peer_tq_xdp_xmit_err; tot->rx_dropped += rx.xdp_tx_err; tot->tx_bytes += rx.xdp_bytes; tot->tx_packets += rx.xdp_packets; } rcu_read_unlock(); } /* fake multicast ability */ static void veth_set_multicast_list(struct net_device *dev) { } static int veth_select_rxq(struct net_device *dev) { return smp_processor_id() % dev->real_num_rx_queues; } static struct net_device *veth_peer_dev(struct net_device *dev) { struct veth_priv *priv = netdev_priv(dev); /* Callers must be under RCU read side. */ return rcu_dereference(priv->peer); } static int veth_xdp_xmit(struct net_device *dev, int n, struct xdp_frame **frames, u32 flags, bool ndo_xmit) { struct veth_priv *rcv_priv, *priv = netdev_priv(dev); int i, ret = -ENXIO, nxmit = 0; struct net_device *rcv; unsigned int max_len; struct veth_rq *rq; if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK)) return -EINVAL; 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)]; /* The napi pointer is set if NAPI is enabled, which ensures that * xdp_ring is initialized on receive side and the peer device is up. */ if (!rcu_access_pointer(rq->napi)) goto out; 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(xdp_get_frame_len(frame) > max_len || __ptr_ring_produce(&rq->xdp_ring, ptr))) break; nxmit++; } spin_unlock(&rq->xdp_ring.producer_lock); if (flags & XDP_XMIT_FLUSH) __veth_xdp_flush(rq); ret = nxmit; if (ndo_xmit) { u64_stats_update_begin(&rq->stats.syncp); rq->stats.vs.peer_tq_xdp_xmit += nxmit; rq->stats.vs.peer_tq_xdp_xmit_err += n - nxmit; u64_stats_update_end(&rq->stats.syncp); } out: rcu_read_unlock(); return ret; } static int veth_ndo_xdp_xmit(struct net_device *dev, int n, struct xdp_frame **frames, u32 flags) { int err; err = veth_xdp_xmit(dev, n, frames, flags, true); if (err < 0) { struct veth_priv *priv = netdev_priv(dev); atomic64_add(n, &priv->dropped); } return err; } static void veth_xdp_flush_bq(struct veth_rq *rq, struct veth_xdp_tx_bq *bq) { int sent, i, err = 0, drops; sent = veth_xdp_xmit(rq->dev, bq->count, bq->q, 0, false); if (sent < 0) { err = sent; sent = 0; } for (i = sent; unlikely(i < bq->count); i++) xdp_return_frame(bq->q[i]); drops = bq->count - sent; trace_xdp_bulk_tx(rq->dev, sent, drops, err); u64_stats_update_begin(&rq->stats.syncp); rq->stats.vs.xdp_tx += sent; rq->stats.vs.xdp_tx_err += drops; u64_stats_update_end(&rq->stats.syncp); bq->count = 0; } static void veth_xdp_flush(struct veth_rq *rq, struct veth_xdp_tx_bq *bq) { struct veth_priv *rcv_priv, *priv = netdev_priv(rq->dev); struct net_device *rcv; struct veth_rq *rcv_rq; rcu_read_lock(); veth_xdp_flush_bq(rq, bq); rcv = rcu_dereference(priv->peer); if (unlikely(!rcv)) goto out; rcv_priv = netdev_priv(rcv); rcv_rq = &rcv_priv->rq[veth_select_rxq(rcv)]; /* xdp_ring is initialized on receive side? */ if (unlikely(!rcu_access_pointer(rcv_rq->xdp_prog))) goto out; __veth_xdp_flush(rcv_rq); out: rcu_read_unlock(); } static int veth_xdp_tx(struct veth_rq *rq, struct xdp_buff *xdp, struct veth_xdp_tx_bq *bq) { struct xdp_frame *frame = xdp_convert_buff_to_frame(xdp); if (unlikely(!frame)) return -EOVERFLOW; if (unlikely(bq->count == VETH_XDP_TX_BULK_SIZE)) veth_xdp_flush_bq(rq, bq); bq->q[bq->count++] = frame; return 0; } static struct xdp_frame *veth_xdp_rcv_one(struct veth_rq *rq, struct xdp_frame *frame, struct veth_xdp_tx_bq *bq, struct veth_stats *stats) { struct xdp_frame orig_frame; struct bpf_prog *xdp_prog; rcu_read_lock(); xdp_prog = rcu_dereference(rq->xdp_prog); if (likely(xdp_prog)) { struct xdp_buff xdp; u32 act; xdp_convert_frame_to_buff(frame, &xdp); xdp.rxq = &rq->xdp_rxq; act = bpf_prog_run_xdp(xdp_prog, &xdp); switch (act) { case XDP_PASS: if (xdp_update_frame_from_buff(&xdp, frame)) goto err_xdp; break; case XDP_TX: orig_frame = *frame; xdp.rxq->mem = frame->mem; if (unlikely(veth_xdp_tx(rq, &xdp, bq) < 0)) { trace_xdp_exception(rq->dev, xdp_prog, act); frame = &orig_frame; stats->rx_drops++; goto err_xdp; } stats->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; stats->rx_drops++; goto err_xdp; } stats->xdp_redirect++; rcu_read_unlock(); goto xdp_xmit; default: bpf_warn_invalid_xdp_action(rq->dev, xdp_prog, act); fallthrough; case XDP_ABORTED: trace_xdp_exception(rq->dev, xdp_prog, act); fallthrough; case XDP_DROP: stats->xdp_drops++; goto err_xdp; } } rcu_read_unlock(); return frame; err_xdp: rcu_read_unlock(); xdp_return_frame(frame); xdp_xmit: return NULL; } /* frames array contains VETH_XDP_BATCH at most */ static void veth_xdp_rcv_bulk_skb(struct veth_rq *rq, void **frames, int n_xdpf, struct veth_xdp_tx_bq *bq, struct veth_stats *stats) { void *skbs[VETH_XDP_BATCH]; int i; if (xdp_alloc_skb_bulk(skbs, n_xdpf, GFP_ATOMIC | __GFP_ZERO) < 0) { for (i = 0; i < n_xdpf; i++) xdp_return_frame(frames[i]); stats->rx_drops += n_xdpf; return; } for (i = 0; i < n_xdpf; i++) { struct sk_buff *skb = skbs[i]; skb = __xdp_build_skb_from_frame(frames[i], skb, rq->dev); if (!skb) { xdp_return_frame(frames[i]); stats->rx_drops++; continue; } napi_gro_receive(&rq->xdp_napi, skb); } } static void veth_xdp_get(struct xdp_buff *xdp) { struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp); int i; get_page(virt_to_page(xdp->data)); if (likely(!xdp_buff_has_frags(xdp))) return; for (i = 0; i < sinfo->nr_frags; i++) __skb_frag_ref(&sinfo->frags[i]); } static int veth_convert_skb_to_xdp_buff(struct veth_rq *rq, struct xdp_buff *xdp, struct sk_buff **pskb) { struct sk_buff *skb = *pskb; u32 frame_sz; if (skb_shared(skb) || skb_head_is_locked(skb) || skb_shinfo(skb)->nr_frags) { u32 size, len, max_head_size, off; struct sk_buff *nskb; struct page *page; int i, head_off; /* We need a private copy of the skb and data buffers since * the ebpf program can modify it. We segment the original skb * into order-0 pages without linearize it. * * Make sure we have enough space for linear and paged area */ max_head_size = SKB_WITH_OVERHEAD(PAGE_SIZE - VETH_XDP_HEADROOM); if (skb->len > PAGE_SIZE * MAX_SKB_FRAGS + max_head_size) goto drop; /* Allocate skb head */ page = alloc_page(GFP_ATOMIC | __GFP_NOWARN); if (!page) goto drop; nskb = build_skb(page_address(page), PAGE_SIZE); if (!nskb) { put_page(page); goto drop; } skb_reserve(nskb, VETH_XDP_HEADROOM); size = min_t(u32, skb->len, max_head_size); if (skb_copy_bits(skb, 0, nskb->data, size)) { consume_skb(nskb); goto drop; } skb_put(nskb, size); skb_copy_header(nskb, skb); head_off = skb_headroom(nskb) - skb_headroom(skb); skb_headers_offset_update(nskb, head_off); /* Allocate paged area of new skb */ off = size; len = skb->len - off; for (i = 0; i < MAX_SKB_FRAGS && off < skb->len; i++) { page = alloc_page(GFP_ATOMIC | __GFP_NOWARN); if (!page) { consume_skb(nskb); goto drop; } size = min_t(u32, len, PAGE_SIZE); skb_add_rx_frag(nskb, i, page, 0, size, PAGE_SIZE); if (skb_copy_bits(skb, off, page_address(page), size)) { consume_skb(nskb); goto drop; } len -= size; off += size; } consume_skb(skb); skb = nskb; } else if (skb_headroom(skb) < XDP_PACKET_HEADROOM && pskb_expand_head(skb, VETH_XDP_HEADROOM, 0, GFP_ATOMIC)) { goto drop; } /* SKB "head" area always have tailroom for skb_shared_info */ frame_sz = skb_end_pointer(skb) - skb->head; frame_sz += SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); xdp_init_buff(xdp, frame_sz, &rq->xdp_rxq); xdp_prepare_buff(xdp, skb->head, skb_headroom(skb), skb_headlen(skb), true); if (skb_is_nonlinear(skb)) { skb_shinfo(skb)->xdp_frags_size = skb->data_len; xdp_buff_set_frags_flag(xdp); } else { xdp_buff_clear_frags_flag(xdp); } *pskb = skb; return 0; drop: consume_skb(skb); *pskb = NULL; return -ENOMEM; } static struct sk_buff *veth_xdp_rcv_skb(struct veth_rq *rq, struct sk_buff *skb, struct veth_xdp_tx_bq *bq, struct veth_stats *stats) { void *orig_data, *orig_data_end; struct bpf_prog *xdp_prog; struct xdp_buff xdp; u32 act, metalen; int off; skb_prepare_for_gro(skb); rcu_read_lock(); xdp_prog = rcu_dereference(rq->xdp_prog); if (unlikely(!xdp_prog)) { rcu_read_unlock(); goto out; } __skb_push(skb, skb->data - skb_mac_header(skb)); if (veth_convert_skb_to_xdp_buff(rq, &xdp, &skb)) goto drop; 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: veth_xdp_get(&xdp); consume_skb(skb); xdp.rxq->mem = rq->xdp_mem; if (unlikely(veth_xdp_tx(rq, &xdp, bq) < 0)) { trace_xdp_exception(rq->dev, xdp_prog, act); stats->rx_drops++; goto err_xdp; } stats->xdp_tx++; rcu_read_unlock(); goto xdp_xmit; case XDP_REDIRECT: veth_xdp_get(&xdp); consume_skb(skb); xdp.rxq->mem = rq->xdp_mem; if (xdp_do_redirect(rq->dev, &xdp, xdp_prog)) { stats->rx_drops++; goto err_xdp; } stats->xdp_redirect++; rcu_read_unlock(); goto xdp_xmit; default: bpf_warn_invalid_xdp_action(rq->dev, xdp_prog, act); fallthrough; case XDP_ABORTED: trace_xdp_exception(rq->dev, xdp_prog, act); fallthrough; case XDP_DROP: stats->xdp_drops++; goto xdp_drop; } rcu_read_unlock(); /* check if bpf_xdp_adjust_head was used */ off = orig_data - xdp.data; if (off > 0) __skb_push(skb, off); else if (off < 0) __skb_pull(skb, -off); skb_reset_mac_header(skb); /* check if bpf_xdp_adjust_tail was used */ off = xdp.data_end - orig_data_end; if (off != 0) __skb_put(skb, off); /* positive on grow, negative on shrink */ /* XDP frag metadata (e.g. nr_frags) are updated in eBPF helpers * (e.g. bpf_xdp_adjust_tail), we need to update data_len here. */ if (xdp_buff_has_frags(&xdp)) skb->data_len = skb_shinfo(skb)->xdp_frags_size; else skb->data_len = 0; 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: stats->rx_drops++; xdp_drop: rcu_read_unlock(); kfree_skb(skb); return NULL; err_xdp: rcu_read_unlock(); xdp_return_buff(&xdp); xdp_xmit: return NULL; } static int veth_xdp_rcv(struct veth_rq *rq, int budget, struct veth_xdp_tx_bq *bq, struct veth_stats *stats) { int i, done = 0, n_xdpf = 0; void *xdpf[VETH_XDP_BATCH]; for (i = 0; i < budget; i++) { void *ptr = __ptr_ring_consume(&rq->xdp_ring); if (!ptr) break; if (veth_is_xdp_frame(ptr)) { /* ndo_xdp_xmit */ struct xdp_frame *frame = veth_ptr_to_xdp(ptr); stats->xdp_bytes += xdp_get_frame_len(frame); frame = veth_xdp_rcv_one(rq, frame, bq, stats); if (frame) { /* XDP_PASS */ xdpf[n_xdpf++] = frame; if (n_xdpf == VETH_XDP_BATCH) { veth_xdp_rcv_bulk_skb(rq, xdpf, n_xdpf, bq, stats); n_xdpf = 0; } } } else { /* ndo_start_xmit */ struct sk_buff *skb = ptr; stats->xdp_bytes += skb->len; skb = veth_xdp_rcv_skb(rq, skb, bq, stats); if (skb) { if (skb_shared(skb) || skb_unclone(skb, GFP_ATOMIC)) netif_receive_skb(skb); else napi_gro_receive(&rq->xdp_napi, skb); } } done++; } if (n_xdpf) veth_xdp_rcv_bulk_skb(rq, xdpf, n_xdpf, bq, stats); u64_stats_update_begin(&rq->stats.syncp); rq->stats.vs.xdp_redirect += stats->xdp_redirect; rq->stats.vs.xdp_bytes += stats->xdp_bytes; rq->stats.vs.xdp_drops += stats->xdp_drops; rq->stats.vs.rx_drops += stats->rx_drops; rq->stats.vs.xdp_packets += done; u64_stats_update_end(&rq->stats.syncp); return done; } static int veth_poll(struct napi_struct *napi, int budget) { struct veth_rq *rq = container_of(napi, struct veth_rq, xdp_napi); struct veth_stats stats = {}; struct veth_xdp_tx_bq bq; int done; bq.count = 0; xdp_set_return_frame_no_direct(); done = veth_xdp_rcv(rq, budget, &bq, &stats); 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 (stats.xdp_tx > 0) veth_xdp_flush(rq, &bq); if (stats.xdp_redirect > 0) xdp_do_flush(); xdp_clear_return_frame_no_direct(); return done; } static int __veth_napi_enable_range(struct net_device *dev, int start, int end) { struct veth_priv *priv = netdev_priv(dev); int err, i; for (i = start; i < end; 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 = start; i < end; i++) { struct veth_rq *rq = &priv->rq[i]; napi_enable(&rq->xdp_napi); rcu_assign_pointer(priv->rq[i].napi, &priv->rq[i].xdp_napi); } return 0; err_xdp_ring: for (i--; i >= start; i--) ptr_ring_cleanup(&priv->rq[i].xdp_ring, veth_ptr_free); return err; } static int __veth_napi_enable(struct net_device *dev) { return __veth_napi_enable_range(dev, 0, dev->real_num_rx_queues); } static void veth_napi_del_range(struct net_device *dev, int start, int end) { struct veth_priv *priv = netdev_priv(dev); int i; for (i = start; i < end; i++) { struct veth_rq *rq = &priv->rq[i]; rcu_assign_pointer(priv->rq[i].napi, NULL); napi_disable(&rq->xdp_napi); __netif_napi_del(&rq->xdp_napi); } synchronize_net(); for (i = start; i < end; i++) { struct veth_rq *rq = &priv->rq[i]; rq->rx_notify_masked = false; ptr_ring_cleanup(&rq->xdp_ring, veth_ptr_free); } } static void veth_napi_del(struct net_device *dev) { veth_napi_del_range(dev, 0, dev->real_num_rx_queues); } static bool veth_gro_requested(const struct net_device *dev) { return !!(dev->wanted_features & NETIF_F_GRO); } static int veth_enable_xdp_range(struct net_device *dev, int start, int end, bool napi_already_on) { struct veth_priv *priv = netdev_priv(dev); int err, i; for (i = start; i < end; i++) { struct veth_rq *rq = &priv->rq[i]; if (!napi_already_on) netif_napi_add(dev, &rq->xdp_napi, veth_poll, NAPI_POLL_WEIGHT); err = xdp_rxq_info_reg(&rq->xdp_rxq, dev, i, rq->xdp_napi.napi_id); 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; } return 0; err_reg_mem: xdp_rxq_info_unreg(&priv->rq[i].xdp_rxq); err_rxq_reg: for (i--; i >= start; i--) { struct veth_rq *rq = &priv->rq[i]; xdp_rxq_info_unreg(&rq->xdp_rxq); if (!napi_already_on) netif_napi_del(&rq->xdp_napi); } return err; } static void veth_disable_xdp_range(struct net_device *dev, int start, int end, bool delete_napi) { struct veth_priv *priv = netdev_priv(dev); int i; for (i = start; i < end; i++) { struct veth_rq *rq = &priv->rq[i]; rq->xdp_rxq.mem = rq->xdp_mem; xdp_rxq_info_unreg(&rq->xdp_rxq); if (delete_napi) netif_napi_del(&rq->xdp_napi); } } static int veth_enable_xdp(struct net_device *dev) { bool napi_already_on = veth_gro_requested(dev) && (dev->flags & IFF_UP); struct veth_priv *priv = netdev_priv(dev); int err, i; if (!xdp_rxq_info_is_reg(&priv->rq[0].xdp_rxq)) { err = veth_enable_xdp_range(dev, 0, dev->real_num_rx_queues, napi_already_on); if (err) return err; if (!napi_already_on) { err = __veth_napi_enable(dev); if (err) { veth_disable_xdp_range(dev, 0, dev->real_num_rx_queues, true); return err; } if (!veth_gro_requested(dev)) { /* user-space did not require GRO, but adding XDP * is supposed to get GRO working */ dev->features |= NETIF_F_GRO; netdev_features_change(dev); } } } for (i = 0; i < dev->real_num_rx_queues; i++) { rcu_assign_pointer(priv->rq[i].xdp_prog, priv->_xdp_prog); rcu_assign_pointer(priv->rq[i].napi, &priv->rq[i].xdp_napi); } return 0; } 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); if (!netif_running(dev) || !veth_gro_requested(dev)) { veth_napi_del(dev); /* if user-space did not require GRO, since adding XDP * enabled it, clear it now */ if (!veth_gro_requested(dev) && netif_running(dev)) { dev->features &= ~NETIF_F_GRO; netdev_features_change(dev); } } veth_disable_xdp_range(dev, 0, dev->real_num_rx_queues, false); } static int veth_napi_enable_range(struct net_device *dev, int start, int end) { struct veth_priv *priv = netdev_priv(dev); int err, i; for (i = start; i < end; i++) { struct veth_rq *rq = &priv->rq[i]; netif_napi_add(dev, &rq->xdp_napi, veth_poll, NAPI_POLL_WEIGHT); } err = __veth_napi_enable_range(dev, start, end); if (err) { for (i = start; i < end; i++) { struct veth_rq *rq = &priv->rq[i]; netif_napi_del(&rq->xdp_napi); } return err; } return err; } static int veth_napi_enable(struct net_device *dev) { return veth_napi_enable_range(dev, 0, dev->real_num_rx_queues); } static void veth_disable_range_safe(struct net_device *dev, int start, int end) { struct veth_priv *priv = netdev_priv(dev); if (start >= end) return; if (priv->_xdp_prog) { veth_napi_del_range(dev, start, end); veth_disable_xdp_range(dev, start, end, false); } else if (veth_gro_requested(dev)) { veth_napi_del_range(dev, start, end); } } static int veth_enable_range_safe(struct net_device *dev, int start, int end) { struct veth_priv *priv = netdev_priv(dev); int err; if (start >= end) return 0; if (priv->_xdp_prog) { /* these channels are freshly initialized, napi is not on there even * when GRO is requeste */ err = veth_enable_xdp_range(dev, start, end, false); if (err) return err; err = __veth_napi_enable_range(dev, start, end); if (err) { /* on error always delete the newly added napis */ veth_disable_xdp_range(dev, start, end, true); return err; } } else if (veth_gro_requested(dev)) { return veth_napi_enable_range(dev, start, end); } return 0; } static int veth_set_channels(struct net_device *dev, struct ethtool_channels *ch) { struct veth_priv *priv = netdev_priv(dev); unsigned int old_rx_count, new_rx_count; struct veth_priv *peer_priv; struct net_device *peer; int err; /* sanity check. Upper bounds are already enforced by the caller */ if (!ch->rx_count || !ch->tx_count) return -EINVAL; /* avoid braking XDP, if that is enabled */ peer = rtnl_dereference(priv->peer); peer_priv = peer ? netdev_priv(peer) : NULL; if (priv->_xdp_prog && peer && ch->rx_count < peer->real_num_tx_queues) return -EINVAL; if (peer && peer_priv && peer_priv->_xdp_prog && ch->tx_count > peer->real_num_rx_queues) return -EINVAL; old_rx_count = dev->real_num_rx_queues; new_rx_count = ch->rx_count; if (netif_running(dev)) { /* turn device off */ netif_carrier_off(dev); if (peer) netif_carrier_off(peer); /* try to allocate new resurces, as needed*/ err = veth_enable_range_safe(dev, old_rx_count, new_rx_count); if (err) goto out; } err = netif_set_real_num_rx_queues(dev, ch->rx_count); if (err) goto revert; err = netif_set_real_num_tx_queues(dev, ch->tx_count); if (err) { int err2 = netif_set_real_num_rx_queues(dev, old_rx_count); /* this error condition could happen only if rx and tx change * in opposite directions (e.g. tx nr raises, rx nr decreases) * and we can't do anything to fully restore the original * status */ if (err2) pr_warn("Can't restore rx queues config %d -> %d %d", new_rx_count, old_rx_count, err2); else goto revert; } out: if (netif_running(dev)) { /* note that we need to swap the arguments WRT the enable part * to identify the range we have to disable */ veth_disable_range_safe(dev, new_rx_count, old_rx_count); netif_carrier_on(dev); if (peer) netif_carrier_on(peer); } return err; revert: new_rx_count = old_rx_count; old_rx_count = ch->rx_count; goto out; } 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; } else if (veth_gro_requested(dev)) { err = veth_napi_enable(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); else if (veth_gro_requested(dev)) veth_napi_del(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_ACCOUNT); if (!priv->rq) return -ENOMEM; for (i = 0; i < dev->num_rx_queues; i++) { priv->rq[i].dev = dev; u64_stats_init(&priv->rq[i].stats.syncp); } 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->lstats = netdev_alloc_pcpu_stats(struct pcpu_lstats); if (!dev->lstats) return -ENOMEM; err = veth_alloc_queues(dev); if (err) { free_percpu(dev->lstats); return err; } return 0; } static void veth_dev_free(struct net_device *dev) { veth_free_queues(dev); free_percpu(dev->lstats); } #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; } if (priv->_xdp_prog) features |= NETIF_F_GRO; return features; } static int veth_set_features(struct net_device *dev, netdev_features_t features) { netdev_features_t changed = features ^ dev->features; struct veth_priv *priv = netdev_priv(dev); int err; if (!(changed & NETIF_F_GRO) || !(dev->flags & IFF_UP) || priv->_xdp_prog) return 0; if (features & NETIF_F_GRO) { err = veth_napi_enable(dev); if (err) return err; } else { veth_napi_del(dev); } return 0; } 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 = SKB_WITH_OVERHEAD(PAGE_SIZE - VETH_XDP_HEADROOM) - peer->hard_header_len; /* Allow increasing the max_mtu if the program supports * XDP fragments. */ if (prog->aux->xdp_has_frags) max_mtu += PAGE_SIZE * MAX_SKB_FRAGS; 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 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); 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_set_features = veth_set_features, .ndo_features_check = passthru_features_check, .ndo_set_rx_headroom = veth_set_rx_headroom, .ndo_bpf = veth_xdp, .ndo_xdp_xmit = veth_ndo_xdp_xmit, .ndo_get_peer_dev = veth_peer_dev, }; #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; netif_set_tso_max_size(dev, GSO_MAX_SIZE); } /* * 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 void veth_disable_gro(struct net_device *dev) { dev->features &= ~NETIF_F_GRO; dev->wanted_features &= ~NETIF_F_GRO; netdev_update_features(dev); } static int veth_init_queues(struct net_device *dev, struct nlattr *tb[]) { int err; if (!tb[IFLA_NUM_TX_QUEUES] && dev->num_tx_queues > 1) { err = netif_set_real_num_tx_queues(dev, 1); if (err) return err; } if (!tb[IFLA_NUM_RX_QUEUES] && dev->num_rx_queues > 1) { err = netif_set_real_num_rx_queues(dev, 1); if (err) return err; } return 0; } 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_strscpy(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, extack); 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; netif_inherit_tso_max(peer, dev); err = register_netdevice(peer); put_net(net); net = NULL; if (err < 0) goto err_register_peer; /* keep GRO disabled by default to be consistent with the established * veth behavior */ veth_disable_gro(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_strscpy(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); err = veth_init_queues(dev, tb); if (err) goto err_queues; priv = netdev_priv(peer); rcu_assign_pointer(priv->peer, dev); err = veth_init_queues(peer, tb); if (err) goto err_queues; veth_disable_gro(dev); return 0; err_queues: unregister_netdevice(dev); 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 unsigned int veth_get_num_queues(void) { /* enforce the same queue limit as rtnl_create_link */ int queues = num_possible_cpus(); if (queues > 4096) queues = 4096; return queues; } 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, .get_num_tx_queues = veth_get_num_queues, .get_num_rx_queues = veth_get_num_queues, }; /* * 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);