// SPDX-License-Identifier: GPL-2.0-only /* * drivers/net/veth.c * * Copyright (C) 2007 OpenVZ http://openvz.org, SWsoft Inc * * Author: Pavel Emelianov * Ethtool interface from: Eric W. Biederman * */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #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) #define VETH_XDP_TX_BULK_SIZE 16 struct veth_stats { u64 xdp_packets; u64 xdp_bytes; u64 xdp_drops; }; struct veth_rq_stats { struct veth_stats vs; 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; 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) }, { "xdp_drops", VETH_RQ_STAT(xdp_drops) }, }; #define VETH_RQ_STATS_LEN ARRAY_SIZE(veth_rq_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) { char *p = (char *)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++) { snprintf(p, ETH_GSTRING_LEN, "rx_queue_%u_%.11s", i, veth_rq_stats_desc[j].desc); p += ETH_GSTRING_LEN; } } 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; 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); 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; } } 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, }; /* 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); } skb_tx_timestamp(skb); if (likely(veth_forward_skb(rcv, skb, rq, rcv_xdp) == NET_RX_SUCCESS)) { if (!rcv_xdp) dev_lstats_add(dev, length); } else { drop: atomic64_inc(&priv->dropped); } if (rcv_xdp) __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->xdp_packets = 0; result->xdp_bytes = 0; result->xdp_drops = 0; for (i = 0; i < dev->num_rx_queues; i++) { struct veth_rq_stats *stats = &priv->rq[i].stats; u64 packets, bytes, drops; unsigned int start; do { start = u64_stats_fetch_begin_irq(&stats->syncp); packets = stats->vs.xdp_packets; bytes = stats->vs.xdp_bytes; drops = stats->vs.xdp_drops; } while (u64_stats_fetch_retry_irq(&stats->syncp, start)); result->xdp_packets += packets; result->xdp_bytes += bytes; result->xdp_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->rx_dropped = rx.xdp_drops; 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_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 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; int i, ret, drops = n; unsigned int max_len; struct veth_rq *rq; rcu_read_lock(); if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK)) { ret = -EINVAL; goto drop; } rcv = rcu_dereference(priv->peer); if (unlikely(!rcv)) { ret = -ENXIO; goto drop; } 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)) { ret = -ENXIO; goto drop; } drops = 0; 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); if (likely(!drops)) { rcu_read_unlock(); return n; } ret = n - drops; drop: rcu_read_unlock(); atomic64_add(drops, &priv->dropped); return ret; } static void veth_xdp_flush_bq(struct net_device *dev, struct veth_xdp_tx_bq *bq) { int sent, i, err = 0; sent = veth_xdp_xmit(dev, bq->count, bq->q, 0); if (sent < 0) { err = sent; sent = 0; for (i = 0; i < bq->count; i++) xdp_return_frame(bq->q[i]); } trace_xdp_bulk_tx(dev, sent, bq->count - sent, err); bq->count = 0; } static void veth_xdp_flush(struct net_device *dev, struct veth_xdp_tx_bq *bq) { struct veth_priv *rcv_priv, *priv = netdev_priv(dev); struct net_device *rcv; struct veth_rq *rq; rcu_read_lock(); veth_xdp_flush_bq(dev, bq); 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 veth_xdp_tx_bq *bq) { struct xdp_frame *frame = convert_to_xdp_frame(xdp); if (unlikely(!frame)) return -EOVERFLOW; if (unlikely(bq->count == VETH_XDP_TX_BULK_SIZE)) veth_xdp_flush_bq(dev, bq); bq->q[bq->count++] = frame; return 0; } static struct sk_buff *veth_xdp_rcv_one(struct veth_rq *rq, struct xdp_frame *frame, unsigned int *xdp_xmit, struct veth_xdp_tx_bq *bq) { 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, bq) < 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); /* fall through */ case XDP_ABORTED: trace_xdp_exception(rq->dev, xdp_prog, act); /* fall through */ 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_release_frame(frame); 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, struct veth_xdp_tx_bq *bq) { 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, bq) < 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); /* fall through */ case XDP_ABORTED: trace_xdp_exception(rq->dev, xdp_prog, act); /* fall through */ 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, struct veth_xdp_tx_bq *bq) { int i, done = 0, drops = 0, bytes = 0; for (i = 0; i < budget; i++) { void *ptr = __ptr_ring_consume(&rq->xdp_ring); unsigned int xdp_xmit_one = 0; struct sk_buff *skb; if (!ptr) break; if (veth_is_xdp_frame(ptr)) { struct xdp_frame *frame = veth_ptr_to_xdp(ptr); bytes += frame->len; skb = veth_xdp_rcv_one(rq, frame, &xdp_xmit_one, bq); } else { skb = ptr; bytes += skb->len; skb = veth_xdp_rcv_skb(rq, skb, &xdp_xmit_one, bq); } *xdp_xmit |= xdp_xmit_one; if (skb) napi_gro_receive(&rq->xdp_napi, skb); else if (!xdp_xmit_one) drops++; done++; } u64_stats_update_begin(&rq->stats.syncp); rq->stats.vs.xdp_packets += done; rq->stats.vs.xdp_bytes += bytes; rq->stats.vs.xdp_drops += drops; 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); unsigned int xdp_xmit = 0; struct veth_xdp_tx_bq bq; int done; bq.count = 0; xdp_set_return_frame_no_direct(); done = veth_xdp_rcv(rq, budget, &xdp_xmit, &bq); 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, &bq); if (xdp_xmit & VETH_XDP_REDIR) xdp_do_flush(); 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; 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; } 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, 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; 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);