/* * vrf.c: device driver to encapsulate a VRF space * * Copyright (c) 2015 Cumulus Networks. All rights reserved. * Copyright (c) 2015 Shrijeet Mukherjee <shm@cumulusnetworks.com> * Copyright (c) 2015 David Ahern <dsa@cumulusnetworks.com> * * Based on dummy, team and ipvlan drivers * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. */ #include <linux/module.h> #include <linux/kernel.h> #include <linux/netdevice.h> #include <linux/etherdevice.h> #include <linux/ip.h> #include <linux/init.h> #include <linux/moduleparam.h> #include <linux/netfilter.h> #include <linux/rtnetlink.h> #include <net/rtnetlink.h> #include <linux/u64_stats_sync.h> #include <linux/hashtable.h> #include <linux/inetdevice.h> #include <net/arp.h> #include <net/ip.h> #include <net/ip_fib.h> #include <net/ip6_fib.h> #include <net/ip6_route.h> #include <net/route.h> #include <net/addrconf.h> #include <net/l3mdev.h> #include <net/fib_rules.h> #define RT_FL_TOS(oldflp4) \ ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK)) #define DRV_NAME "vrf" #define DRV_VERSION "1.0" #define FIB_RULE_PREF 1000 /* default preference for FIB rules */ static bool add_fib_rules = true; struct net_vrf { struct rtable __rcu *rth; struct rtable __rcu *rth_local; struct rt6_info __rcu *rt6; struct rt6_info __rcu *rt6_local; u32 tb_id; }; struct pcpu_dstats { u64 tx_pkts; u64 tx_bytes; u64 tx_drps; u64 rx_pkts; u64 rx_bytes; u64 rx_drps; struct u64_stats_sync syncp; }; static void vrf_rx_stats(struct net_device *dev, int len) { struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats); u64_stats_update_begin(&dstats->syncp); dstats->rx_pkts++; dstats->rx_bytes += len; u64_stats_update_end(&dstats->syncp); } static void vrf_tx_error(struct net_device *vrf_dev, struct sk_buff *skb) { vrf_dev->stats.tx_errors++; kfree_skb(skb); } static struct rtnl_link_stats64 *vrf_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats) { int i; for_each_possible_cpu(i) { const struct pcpu_dstats *dstats; u64 tbytes, tpkts, tdrops, rbytes, rpkts; unsigned int start; dstats = per_cpu_ptr(dev->dstats, i); do { start = u64_stats_fetch_begin_irq(&dstats->syncp); tbytes = dstats->tx_bytes; tpkts = dstats->tx_pkts; tdrops = dstats->tx_drps; rbytes = dstats->rx_bytes; rpkts = dstats->rx_pkts; } while (u64_stats_fetch_retry_irq(&dstats->syncp, start)); stats->tx_bytes += tbytes; stats->tx_packets += tpkts; stats->tx_dropped += tdrops; stats->rx_bytes += rbytes; stats->rx_packets += rpkts; } return stats; } /* Local traffic destined to local address. Reinsert the packet to rx * path, similar to loopback handling. */ static int vrf_local_xmit(struct sk_buff *skb, struct net_device *dev, struct dst_entry *dst) { int len = skb->len; skb_orphan(skb); skb_dst_set(skb, dst); skb_dst_force(skb); /* set pkt_type to avoid skb hitting packet taps twice - * once on Tx and again in Rx processing */ skb->pkt_type = PACKET_LOOPBACK; skb->protocol = eth_type_trans(skb, dev); if (likely(netif_rx(skb) == NET_RX_SUCCESS)) vrf_rx_stats(dev, len); else this_cpu_inc(dev->dstats->rx_drps); return NETDEV_TX_OK; } #if IS_ENABLED(CONFIG_IPV6) static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb, struct net_device *dev) { const struct ipv6hdr *iph = ipv6_hdr(skb); struct net *net = dev_net(skb->dev); struct flowi6 fl6 = { /* needed to match OIF rule */ .flowi6_oif = dev->ifindex, .flowi6_iif = LOOPBACK_IFINDEX, .daddr = iph->daddr, .saddr = iph->saddr, .flowlabel = ip6_flowinfo(iph), .flowi6_mark = skb->mark, .flowi6_proto = iph->nexthdr, .flowi6_flags = FLOWI_FLAG_L3MDEV_SRC | FLOWI_FLAG_SKIP_NH_OIF, }; int ret = NET_XMIT_DROP; struct dst_entry *dst; struct dst_entry *dst_null = &net->ipv6.ip6_null_entry->dst; dst = ip6_route_output(net, NULL, &fl6); if (dst == dst_null) goto err; skb_dst_drop(skb); /* if dst.dev is loopback or the VRF device again this is locally * originated traffic destined to a local address. Short circuit * to Rx path using our local dst */ if (dst->dev == net->loopback_dev || dst->dev == dev) { struct net_vrf *vrf = netdev_priv(dev); struct rt6_info *rt6_local; /* release looked up dst and use cached local dst */ dst_release(dst); rcu_read_lock(); rt6_local = rcu_dereference(vrf->rt6_local); if (unlikely(!rt6_local)) { rcu_read_unlock(); goto err; } /* Ordering issue: cached local dst is created on newlink * before the IPv6 initialization. Using the local dst * requires rt6i_idev to be set so make sure it is. */ if (unlikely(!rt6_local->rt6i_idev)) { rt6_local->rt6i_idev = in6_dev_get(dev); if (!rt6_local->rt6i_idev) { rcu_read_unlock(); goto err; } } dst = &rt6_local->dst; dst_hold(dst); rcu_read_unlock(); return vrf_local_xmit(skb, dev, &rt6_local->dst); } skb_dst_set(skb, dst); /* strip the ethernet header added for pass through VRF device */ __skb_pull(skb, skb_network_offset(skb)); ret = ip6_local_out(net, skb->sk, skb); if (unlikely(net_xmit_eval(ret))) dev->stats.tx_errors++; else ret = NET_XMIT_SUCCESS; return ret; err: vrf_tx_error(dev, skb); return NET_XMIT_DROP; } #else static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb, struct net_device *dev) { vrf_tx_error(dev, skb); return NET_XMIT_DROP; } #endif static netdev_tx_t vrf_process_v4_outbound(struct sk_buff *skb, struct net_device *vrf_dev) { struct iphdr *ip4h = ip_hdr(skb); int ret = NET_XMIT_DROP; struct flowi4 fl4 = { /* needed to match OIF rule */ .flowi4_oif = vrf_dev->ifindex, .flowi4_iif = LOOPBACK_IFINDEX, .flowi4_tos = RT_TOS(ip4h->tos), .flowi4_flags = FLOWI_FLAG_ANYSRC | FLOWI_FLAG_L3MDEV_SRC | FLOWI_FLAG_SKIP_NH_OIF, .daddr = ip4h->daddr, }; struct net *net = dev_net(vrf_dev); struct rtable *rt; rt = ip_route_output_flow(net, &fl4, NULL); if (IS_ERR(rt)) goto err; if (rt->rt_type != RTN_UNICAST && rt->rt_type != RTN_LOCAL) { ip_rt_put(rt); goto err; } skb_dst_drop(skb); /* if dst.dev is loopback or the VRF device again this is locally * originated traffic destined to a local address. Short circuit * to Rx path using our local dst */ if (rt->dst.dev == net->loopback_dev || rt->dst.dev == vrf_dev) { struct net_vrf *vrf = netdev_priv(vrf_dev); struct rtable *rth_local; struct dst_entry *dst = NULL; ip_rt_put(rt); rcu_read_lock(); rth_local = rcu_dereference(vrf->rth_local); if (likely(rth_local)) { dst = &rth_local->dst; dst_hold(dst); } rcu_read_unlock(); if (unlikely(!dst)) goto err; return vrf_local_xmit(skb, vrf_dev, dst); } skb_dst_set(skb, &rt->dst); /* strip the ethernet header added for pass through VRF device */ __skb_pull(skb, skb_network_offset(skb)); if (!ip4h->saddr) { ip4h->saddr = inet_select_addr(skb_dst(skb)->dev, 0, RT_SCOPE_LINK); } ret = ip_local_out(dev_net(skb_dst(skb)->dev), skb->sk, skb); if (unlikely(net_xmit_eval(ret))) vrf_dev->stats.tx_errors++; else ret = NET_XMIT_SUCCESS; out: return ret; err: vrf_tx_error(vrf_dev, skb); goto out; } static netdev_tx_t is_ip_tx_frame(struct sk_buff *skb, struct net_device *dev) { switch (skb->protocol) { case htons(ETH_P_IP): return vrf_process_v4_outbound(skb, dev); case htons(ETH_P_IPV6): return vrf_process_v6_outbound(skb, dev); default: vrf_tx_error(dev, skb); return NET_XMIT_DROP; } } static netdev_tx_t vrf_xmit(struct sk_buff *skb, struct net_device *dev) { netdev_tx_t ret = is_ip_tx_frame(skb, dev); if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN)) { struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats); u64_stats_update_begin(&dstats->syncp); dstats->tx_pkts++; dstats->tx_bytes += skb->len; u64_stats_update_end(&dstats->syncp); } else { this_cpu_inc(dev->dstats->tx_drps); } return ret; } #if IS_ENABLED(CONFIG_IPV6) /* modelled after ip6_finish_output2 */ static int vrf_finish_output6(struct net *net, struct sock *sk, struct sk_buff *skb) { struct dst_entry *dst = skb_dst(skb); struct net_device *dev = dst->dev; struct neighbour *neigh; struct in6_addr *nexthop; int ret; skb->protocol = htons(ETH_P_IPV6); skb->dev = dev; rcu_read_lock_bh(); nexthop = rt6_nexthop((struct rt6_info *)dst, &ipv6_hdr(skb)->daddr); neigh = __ipv6_neigh_lookup_noref(dst->dev, nexthop); if (unlikely(!neigh)) neigh = __neigh_create(&nd_tbl, nexthop, dst->dev, false); if (!IS_ERR(neigh)) { ret = dst_neigh_output(dst, neigh, skb); rcu_read_unlock_bh(); return ret; } rcu_read_unlock_bh(); IP6_INC_STATS(dev_net(dst->dev), ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES); kfree_skb(skb); return -EINVAL; } /* modelled after ip6_output */ static int vrf_output6(struct net *net, struct sock *sk, struct sk_buff *skb) { return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING, net, sk, skb, NULL, skb_dst(skb)->dev, vrf_finish_output6, !(IP6CB(skb)->flags & IP6SKB_REROUTED)); } /* holding rtnl */ static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf) { struct rt6_info *rt6 = rtnl_dereference(vrf->rt6); struct rt6_info *rt6_local = rtnl_dereference(vrf->rt6_local); struct net *net = dev_net(dev); struct dst_entry *dst; RCU_INIT_POINTER(vrf->rt6, NULL); RCU_INIT_POINTER(vrf->rt6_local, NULL); synchronize_rcu(); /* move dev in dst's to loopback so this VRF device can be deleted * - based on dst_ifdown */ if (rt6) { dst = &rt6->dst; dev_put(dst->dev); dst->dev = net->loopback_dev; dev_hold(dst->dev); dst_release(dst); } if (rt6_local) { if (rt6_local->rt6i_idev) in6_dev_put(rt6_local->rt6i_idev); dst = &rt6_local->dst; dev_put(dst->dev); dst->dev = net->loopback_dev; dev_hold(dst->dev); dst_release(dst); } } static int vrf_rt6_create(struct net_device *dev) { int flags = DST_HOST | DST_NOPOLICY | DST_NOXFRM | DST_NOCACHE; struct net_vrf *vrf = netdev_priv(dev); struct net *net = dev_net(dev); struct fib6_table *rt6i_table; struct rt6_info *rt6, *rt6_local; int rc = -ENOMEM; /* IPv6 can be CONFIG enabled and then disabled runtime */ if (!ipv6_mod_enabled()) return 0; rt6i_table = fib6_new_table(net, vrf->tb_id); if (!rt6i_table) goto out; /* create a dst for routing packets out a VRF device */ rt6 = ip6_dst_alloc(net, dev, flags); if (!rt6) goto out; dst_hold(&rt6->dst); rt6->rt6i_table = rt6i_table; rt6->dst.output = vrf_output6; /* create a dst for local routing - packets sent locally * to local address via the VRF device as a loopback */ rt6_local = ip6_dst_alloc(net, dev, flags); if (!rt6_local) { dst_release(&rt6->dst); goto out; } dst_hold(&rt6_local->dst); rt6_local->rt6i_idev = in6_dev_get(dev); rt6_local->rt6i_flags = RTF_UP | RTF_NONEXTHOP | RTF_LOCAL; rt6_local->rt6i_table = rt6i_table; rt6_local->dst.input = ip6_input; rcu_assign_pointer(vrf->rt6, rt6); rcu_assign_pointer(vrf->rt6_local, rt6_local); rc = 0; out: return rc; } #else static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf) { } static int vrf_rt6_create(struct net_device *dev) { return 0; } #endif /* modelled after ip_finish_output2 */ static int vrf_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb) { struct dst_entry *dst = skb_dst(skb); struct rtable *rt = (struct rtable *)dst; struct net_device *dev = dst->dev; unsigned int hh_len = LL_RESERVED_SPACE(dev); struct neighbour *neigh; u32 nexthop; int ret = -EINVAL; /* Be paranoid, rather than too clever. */ if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) { struct sk_buff *skb2; skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev)); if (!skb2) { ret = -ENOMEM; goto err; } if (skb->sk) skb_set_owner_w(skb2, skb->sk); consume_skb(skb); skb = skb2; } rcu_read_lock_bh(); nexthop = (__force u32)rt_nexthop(rt, ip_hdr(skb)->daddr); neigh = __ipv4_neigh_lookup_noref(dev, nexthop); if (unlikely(!neigh)) neigh = __neigh_create(&arp_tbl, &nexthop, dev, false); if (!IS_ERR(neigh)) ret = dst_neigh_output(dst, neigh, skb); rcu_read_unlock_bh(); err: if (unlikely(ret < 0)) vrf_tx_error(skb->dev, skb); return ret; } static int vrf_output(struct net *net, struct sock *sk, struct sk_buff *skb) { struct net_device *dev = skb_dst(skb)->dev; IP_UPD_PO_STATS(net, IPSTATS_MIB_OUT, skb->len); skb->dev = dev; skb->protocol = htons(ETH_P_IP); return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING, net, sk, skb, NULL, dev, vrf_finish_output, !(IPCB(skb)->flags & IPSKB_REROUTED)); } /* holding rtnl */ static void vrf_rtable_release(struct net_device *dev, struct net_vrf *vrf) { struct rtable *rth = rtnl_dereference(vrf->rth); struct rtable *rth_local = rtnl_dereference(vrf->rth_local); struct net *net = dev_net(dev); struct dst_entry *dst; RCU_INIT_POINTER(vrf->rth, NULL); RCU_INIT_POINTER(vrf->rth_local, NULL); synchronize_rcu(); /* move dev in dst's to loopback so this VRF device can be deleted * - based on dst_ifdown */ if (rth) { dst = &rth->dst; dev_put(dst->dev); dst->dev = net->loopback_dev; dev_hold(dst->dev); dst_release(dst); } if (rth_local) { dst = &rth_local->dst; dev_put(dst->dev); dst->dev = net->loopback_dev; dev_hold(dst->dev); dst_release(dst); } } static int vrf_rtable_create(struct net_device *dev) { struct net_vrf *vrf = netdev_priv(dev); struct rtable *rth, *rth_local; if (!fib_new_table(dev_net(dev), vrf->tb_id)) return -ENOMEM; /* create a dst for routing packets out through a VRF device */ rth = rt_dst_alloc(dev, 0, RTN_UNICAST, 1, 1, 0); if (!rth) return -ENOMEM; /* create a dst for local ingress routing - packets sent locally * to local address via the VRF device as a loopback */ rth_local = rt_dst_alloc(dev, RTCF_LOCAL, RTN_LOCAL, 1, 1, 0); if (!rth_local) { dst_release(&rth->dst); return -ENOMEM; } rth->dst.output = vrf_output; rth->rt_table_id = vrf->tb_id; rth_local->rt_table_id = vrf->tb_id; rcu_assign_pointer(vrf->rth, rth); rcu_assign_pointer(vrf->rth_local, rth_local); return 0; } /**************************** device handling ********************/ /* cycle interface to flush neighbor cache and move routes across tables */ static void cycle_netdev(struct net_device *dev) { unsigned int flags = dev->flags; int ret; if (!netif_running(dev)) return; ret = dev_change_flags(dev, flags & ~IFF_UP); if (ret >= 0) ret = dev_change_flags(dev, flags); if (ret < 0) { netdev_err(dev, "Failed to cycle device %s; route tables might be wrong!\n", dev->name); } } static int do_vrf_add_slave(struct net_device *dev, struct net_device *port_dev) { int ret; ret = netdev_master_upper_dev_link(port_dev, dev, NULL, NULL); if (ret < 0) return ret; port_dev->priv_flags |= IFF_L3MDEV_SLAVE; cycle_netdev(port_dev); return 0; } static int vrf_add_slave(struct net_device *dev, struct net_device *port_dev) { if (netif_is_l3_master(port_dev) || netif_is_l3_slave(port_dev)) return -EINVAL; return do_vrf_add_slave(dev, port_dev); } /* inverse of do_vrf_add_slave */ static int do_vrf_del_slave(struct net_device *dev, struct net_device *port_dev) { netdev_upper_dev_unlink(port_dev, dev); port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE; cycle_netdev(port_dev); return 0; } static int vrf_del_slave(struct net_device *dev, struct net_device *port_dev) { return do_vrf_del_slave(dev, port_dev); } static void vrf_dev_uninit(struct net_device *dev) { struct net_vrf *vrf = netdev_priv(dev); struct net_device *port_dev; struct list_head *iter; vrf_rtable_release(dev, vrf); vrf_rt6_release(dev, vrf); netdev_for_each_lower_dev(dev, port_dev, iter) vrf_del_slave(dev, port_dev); free_percpu(dev->dstats); dev->dstats = NULL; } static int vrf_dev_init(struct net_device *dev) { struct net_vrf *vrf = netdev_priv(dev); dev->dstats = netdev_alloc_pcpu_stats(struct pcpu_dstats); if (!dev->dstats) goto out_nomem; /* create the default dst which points back to us */ if (vrf_rtable_create(dev) != 0) goto out_stats; if (vrf_rt6_create(dev) != 0) goto out_rth; dev->flags = IFF_MASTER | IFF_NOARP; /* MTU is irrelevant for VRF device; set to 64k similar to lo */ dev->mtu = 64 * 1024; /* similarly, oper state is irrelevant; set to up to avoid confusion */ dev->operstate = IF_OPER_UP; netdev_lockdep_set_classes(dev); return 0; out_rth: vrf_rtable_release(dev, vrf); out_stats: free_percpu(dev->dstats); dev->dstats = NULL; out_nomem: return -ENOMEM; } static const struct net_device_ops vrf_netdev_ops = { .ndo_init = vrf_dev_init, .ndo_uninit = vrf_dev_uninit, .ndo_start_xmit = vrf_xmit, .ndo_get_stats64 = vrf_get_stats64, .ndo_add_slave = vrf_add_slave, .ndo_del_slave = vrf_del_slave, }; static u32 vrf_fib_table(const struct net_device *dev) { struct net_vrf *vrf = netdev_priv(dev); return vrf->tb_id; } static struct rtable *vrf_get_rtable(const struct net_device *dev, const struct flowi4 *fl4) { struct rtable *rth = NULL; if (!(fl4->flowi4_flags & FLOWI_FLAG_L3MDEV_SRC)) { struct net_vrf *vrf = netdev_priv(dev); rcu_read_lock(); rth = rcu_dereference(vrf->rth); if (likely(rth)) dst_hold(&rth->dst); rcu_read_unlock(); } return rth; } /* called under rcu_read_lock */ static int vrf_get_saddr(struct net_device *dev, struct flowi4 *fl4) { struct fib_result res = { .tclassid = 0 }; struct net *net = dev_net(dev); u32 orig_tos = fl4->flowi4_tos; u8 flags = fl4->flowi4_flags; u8 scope = fl4->flowi4_scope; u8 tos = RT_FL_TOS(fl4); int rc; if (unlikely(!fl4->daddr)) return 0; fl4->flowi4_flags |= FLOWI_FLAG_SKIP_NH_OIF; fl4->flowi4_iif = LOOPBACK_IFINDEX; /* make sure oif is set to VRF device for lookup */ fl4->flowi4_oif = dev->ifindex; fl4->flowi4_tos = tos & IPTOS_RT_MASK; fl4->flowi4_scope = ((tos & RTO_ONLINK) ? RT_SCOPE_LINK : RT_SCOPE_UNIVERSE); rc = fib_lookup(net, fl4, &res, 0); if (!rc) { if (res.type == RTN_LOCAL) fl4->saddr = res.fi->fib_prefsrc ? : fl4->daddr; else fib_select_path(net, &res, fl4, -1); } fl4->flowi4_flags = flags; fl4->flowi4_tos = orig_tos; fl4->flowi4_scope = scope; return rc; } #if IS_ENABLED(CONFIG_IPV6) /* neighbor handling is done with actual device; do not want * to flip skb->dev for those ndisc packets. This really fails * for multiple next protocols (e.g., NEXTHDR_HOP). But it is * a start. */ static bool ipv6_ndisc_frame(const struct sk_buff *skb) { const struct ipv6hdr *iph = ipv6_hdr(skb); bool rc = false; if (iph->nexthdr == NEXTHDR_ICMP) { const struct icmp6hdr *icmph; struct icmp6hdr _icmph; icmph = skb_header_pointer(skb, sizeof(*iph), sizeof(_icmph), &_icmph); if (!icmph) goto out; switch (icmph->icmp6_type) { case NDISC_ROUTER_SOLICITATION: case NDISC_ROUTER_ADVERTISEMENT: case NDISC_NEIGHBOUR_SOLICITATION: case NDISC_NEIGHBOUR_ADVERTISEMENT: case NDISC_REDIRECT: rc = true; break; } } out: return rc; } static struct rt6_info *vrf_ip6_route_lookup(struct net *net, const struct net_device *dev, struct flowi6 *fl6, int ifindex, int flags) { struct net_vrf *vrf = netdev_priv(dev); struct fib6_table *table = NULL; struct rt6_info *rt6; rcu_read_lock(); /* fib6_table does not have a refcnt and can not be freed */ rt6 = rcu_dereference(vrf->rt6); if (likely(rt6)) table = rt6->rt6i_table; rcu_read_unlock(); if (!table) return NULL; return ip6_pol_route(net, table, ifindex, fl6, flags); } static void vrf_ip6_input_dst(struct sk_buff *skb, struct net_device *vrf_dev, int ifindex) { const struct ipv6hdr *iph = ipv6_hdr(skb); struct flowi6 fl6 = { .daddr = iph->daddr, .saddr = iph->saddr, .flowlabel = ip6_flowinfo(iph), .flowi6_mark = skb->mark, .flowi6_proto = iph->nexthdr, .flowi6_iif = ifindex, }; struct net *net = dev_net(vrf_dev); struct rt6_info *rt6; rt6 = vrf_ip6_route_lookup(net, vrf_dev, &fl6, ifindex, RT6_LOOKUP_F_HAS_SADDR | RT6_LOOKUP_F_IFACE); if (unlikely(!rt6)) return; if (unlikely(&rt6->dst == &net->ipv6.ip6_null_entry->dst)) return; skb_dst_set(skb, &rt6->dst); } static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev, struct sk_buff *skb) { int orig_iif = skb->skb_iif; bool need_strict; /* loopback traffic; do not push through packet taps again. * Reset pkt_type for upper layers to process skb */ if (skb->pkt_type == PACKET_LOOPBACK) { skb->dev = vrf_dev; skb->skb_iif = vrf_dev->ifindex; skb->pkt_type = PACKET_HOST; goto out; } /* if packet is NDISC or addressed to multicast or link-local * then keep the ingress interface */ need_strict = rt6_need_strict(&ipv6_hdr(skb)->daddr); if (!ipv6_ndisc_frame(skb) && !need_strict) { skb->dev = vrf_dev; skb->skb_iif = vrf_dev->ifindex; skb_push(skb, skb->mac_len); dev_queue_xmit_nit(skb, vrf_dev); skb_pull(skb, skb->mac_len); IP6CB(skb)->flags |= IP6SKB_L3SLAVE; } if (need_strict) vrf_ip6_input_dst(skb, vrf_dev, orig_iif); out: return skb; } #else static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev, struct sk_buff *skb) { return skb; } #endif static struct sk_buff *vrf_ip_rcv(struct net_device *vrf_dev, struct sk_buff *skb) { skb->dev = vrf_dev; skb->skb_iif = vrf_dev->ifindex; /* loopback traffic; do not push through packet taps again. * Reset pkt_type for upper layers to process skb */ if (skb->pkt_type == PACKET_LOOPBACK) { skb->pkt_type = PACKET_HOST; goto out; } skb_push(skb, skb->mac_len); dev_queue_xmit_nit(skb, vrf_dev); skb_pull(skb, skb->mac_len); out: return skb; } /* called with rcu lock held */ static struct sk_buff *vrf_l3_rcv(struct net_device *vrf_dev, struct sk_buff *skb, u16 proto) { switch (proto) { case AF_INET: return vrf_ip_rcv(vrf_dev, skb); case AF_INET6: return vrf_ip6_rcv(vrf_dev, skb); } return skb; } #if IS_ENABLED(CONFIG_IPV6) static struct dst_entry *vrf_get_rt6_dst(const struct net_device *dev, struct flowi6 *fl6) { bool need_strict = rt6_need_strict(&fl6->daddr); struct net_vrf *vrf = netdev_priv(dev); struct net *net = dev_net(dev); struct dst_entry *dst = NULL; struct rt6_info *rt; /* send to link-local or multicast address */ if (need_strict) { int flags = RT6_LOOKUP_F_IFACE; /* VRF device does not have a link-local address and * sending packets to link-local or mcast addresses over * a VRF device does not make sense */ if (fl6->flowi6_oif == dev->ifindex) { struct dst_entry *dst = &net->ipv6.ip6_null_entry->dst; dst_hold(dst); return dst; } if (!ipv6_addr_any(&fl6->saddr)) flags |= RT6_LOOKUP_F_HAS_SADDR; rt = vrf_ip6_route_lookup(net, dev, fl6, fl6->flowi6_oif, flags); if (rt) dst = &rt->dst; } else if (!(fl6->flowi6_flags & FLOWI_FLAG_L3MDEV_SRC)) { rcu_read_lock(); rt = rcu_dereference(vrf->rt6); if (likely(rt)) { dst = &rt->dst; dst_hold(dst); } rcu_read_unlock(); } /* make sure oif is set to VRF device for lookup */ if (!need_strict) fl6->flowi6_oif = dev->ifindex; return dst; } /* called under rcu_read_lock */ static int vrf_get_saddr6(struct net_device *dev, const struct sock *sk, struct flowi6 *fl6) { struct net *net = dev_net(dev); struct dst_entry *dst; struct rt6_info *rt; int err; if (rt6_need_strict(&fl6->daddr)) { rt = vrf_ip6_route_lookup(net, dev, fl6, fl6->flowi6_oif, RT6_LOOKUP_F_IFACE); if (unlikely(!rt)) return 0; dst = &rt->dst; } else { __u8 flags = fl6->flowi6_flags; fl6->flowi6_flags |= FLOWI_FLAG_L3MDEV_SRC; fl6->flowi6_flags |= FLOWI_FLAG_SKIP_NH_OIF; dst = ip6_route_output(net, sk, fl6); rt = (struct rt6_info *)dst; fl6->flowi6_flags = flags; } err = dst->error; if (!err) { err = ip6_route_get_saddr(net, rt, &fl6->daddr, sk ? inet6_sk(sk)->srcprefs : 0, &fl6->saddr); } dst_release(dst); return err; } #endif static const struct l3mdev_ops vrf_l3mdev_ops = { .l3mdev_fib_table = vrf_fib_table, .l3mdev_get_rtable = vrf_get_rtable, .l3mdev_get_saddr = vrf_get_saddr, .l3mdev_l3_rcv = vrf_l3_rcv, #if IS_ENABLED(CONFIG_IPV6) .l3mdev_get_rt6_dst = vrf_get_rt6_dst, .l3mdev_get_saddr6 = vrf_get_saddr6, #endif }; static void vrf_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 const struct ethtool_ops vrf_ethtool_ops = { .get_drvinfo = vrf_get_drvinfo, }; static inline size_t vrf_fib_rule_nl_size(void) { size_t sz; sz = NLMSG_ALIGN(sizeof(struct fib_rule_hdr)); sz += nla_total_size(sizeof(u8)); /* FRA_L3MDEV */ sz += nla_total_size(sizeof(u32)); /* FRA_PRIORITY */ return sz; } static int vrf_fib_rule(const struct net_device *dev, __u8 family, bool add_it) { struct fib_rule_hdr *frh; struct nlmsghdr *nlh; struct sk_buff *skb; int err; if (family == AF_INET6 && !ipv6_mod_enabled()) return 0; skb = nlmsg_new(vrf_fib_rule_nl_size(), GFP_KERNEL); if (!skb) return -ENOMEM; nlh = nlmsg_put(skb, 0, 0, 0, sizeof(*frh), 0); if (!nlh) goto nla_put_failure; /* rule only needs to appear once */ nlh->nlmsg_flags &= NLM_F_EXCL; frh = nlmsg_data(nlh); memset(frh, 0, sizeof(*frh)); frh->family = family; frh->action = FR_ACT_TO_TBL; if (nla_put_u32(skb, FRA_L3MDEV, 1)) goto nla_put_failure; if (nla_put_u32(skb, FRA_PRIORITY, FIB_RULE_PREF)) goto nla_put_failure; nlmsg_end(skb, nlh); /* fib_nl_{new,del}rule handling looks for net from skb->sk */ skb->sk = dev_net(dev)->rtnl; if (add_it) { err = fib_nl_newrule(skb, nlh); if (err == -EEXIST) err = 0; } else { err = fib_nl_delrule(skb, nlh); if (err == -ENOENT) err = 0; } nlmsg_free(skb); return err; nla_put_failure: nlmsg_free(skb); return -EMSGSIZE; } static int vrf_add_fib_rules(const struct net_device *dev) { int err; err = vrf_fib_rule(dev, AF_INET, true); if (err < 0) goto out_err; err = vrf_fib_rule(dev, AF_INET6, true); if (err < 0) goto ipv6_err; return 0; ipv6_err: vrf_fib_rule(dev, AF_INET, false); out_err: netdev_err(dev, "Failed to add FIB rules.\n"); return err; } static void vrf_setup(struct net_device *dev) { ether_setup(dev); /* Initialize the device structure. */ dev->netdev_ops = &vrf_netdev_ops; dev->l3mdev_ops = &vrf_l3mdev_ops; dev->ethtool_ops = &vrf_ethtool_ops; dev->destructor = free_netdev; /* Fill in device structure with ethernet-generic values. */ eth_hw_addr_random(dev); /* don't acquire vrf device's netif_tx_lock when transmitting */ dev->features |= NETIF_F_LLTX; /* don't allow vrf devices to change network namespaces. */ dev->features |= NETIF_F_NETNS_LOCAL; /* does not make sense for a VLAN to be added to a vrf device */ dev->features |= NETIF_F_VLAN_CHALLENGED; /* enable offload features */ dev->features |= NETIF_F_GSO_SOFTWARE; dev->features |= NETIF_F_RXCSUM | NETIF_F_HW_CSUM; dev->features |= NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA; dev->hw_features = dev->features; dev->hw_enc_features = dev->features; /* default to no qdisc; user can add if desired */ dev->priv_flags |= IFF_NO_QUEUE; } static int vrf_validate(struct nlattr *tb[], struct nlattr *data[]) { 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; } return 0; } static void vrf_dellink(struct net_device *dev, struct list_head *head) { unregister_netdevice_queue(dev, head); } static int vrf_newlink(struct net *src_net, struct net_device *dev, struct nlattr *tb[], struct nlattr *data[]) { struct net_vrf *vrf = netdev_priv(dev); int err; if (!data || !data[IFLA_VRF_TABLE]) return -EINVAL; vrf->tb_id = nla_get_u32(data[IFLA_VRF_TABLE]); dev->priv_flags |= IFF_L3MDEV_MASTER; err = register_netdevice(dev); if (err) goto out; if (add_fib_rules) { err = vrf_add_fib_rules(dev); if (err) { unregister_netdevice(dev); goto out; } add_fib_rules = false; } out: return err; } static size_t vrf_nl_getsize(const struct net_device *dev) { return nla_total_size(sizeof(u32)); /* IFLA_VRF_TABLE */ } static int vrf_fillinfo(struct sk_buff *skb, const struct net_device *dev) { struct net_vrf *vrf = netdev_priv(dev); return nla_put_u32(skb, IFLA_VRF_TABLE, vrf->tb_id); } static size_t vrf_get_slave_size(const struct net_device *bond_dev, const struct net_device *slave_dev) { return nla_total_size(sizeof(u32)); /* IFLA_VRF_PORT_TABLE */ } static int vrf_fill_slave_info(struct sk_buff *skb, const struct net_device *vrf_dev, const struct net_device *slave_dev) { struct net_vrf *vrf = netdev_priv(vrf_dev); if (nla_put_u32(skb, IFLA_VRF_PORT_TABLE, vrf->tb_id)) return -EMSGSIZE; return 0; } static const struct nla_policy vrf_nl_policy[IFLA_VRF_MAX + 1] = { [IFLA_VRF_TABLE] = { .type = NLA_U32 }, }; static struct rtnl_link_ops vrf_link_ops __read_mostly = { .kind = DRV_NAME, .priv_size = sizeof(struct net_vrf), .get_size = vrf_nl_getsize, .policy = vrf_nl_policy, .validate = vrf_validate, .fill_info = vrf_fillinfo, .get_slave_size = vrf_get_slave_size, .fill_slave_info = vrf_fill_slave_info, .newlink = vrf_newlink, .dellink = vrf_dellink, .setup = vrf_setup, .maxtype = IFLA_VRF_MAX, }; static int vrf_device_event(struct notifier_block *unused, unsigned long event, void *ptr) { struct net_device *dev = netdev_notifier_info_to_dev(ptr); /* only care about unregister events to drop slave references */ if (event == NETDEV_UNREGISTER) { struct net_device *vrf_dev; if (!netif_is_l3_slave(dev)) goto out; vrf_dev = netdev_master_upper_dev_get(dev); vrf_del_slave(vrf_dev, dev); } out: return NOTIFY_DONE; } static struct notifier_block vrf_notifier_block __read_mostly = { .notifier_call = vrf_device_event, }; static int __init vrf_init_module(void) { int rc; register_netdevice_notifier(&vrf_notifier_block); rc = rtnl_link_register(&vrf_link_ops); if (rc < 0) goto error; return 0; error: unregister_netdevice_notifier(&vrf_notifier_block); return rc; } module_init(vrf_init_module); MODULE_AUTHOR("Shrijeet Mukherjee, David Ahern"); MODULE_DESCRIPTION("Device driver to instantiate VRF domains"); MODULE_LICENSE("GPL"); MODULE_ALIAS_RTNL_LINK(DRV_NAME); MODULE_VERSION(DRV_VERSION);