diff options
Diffstat (limited to 'drivers/net/vrf.c')
| -rw-r--r-- | drivers/net/vrf.c | 1519 |
1 files changed, 1519 insertions, 0 deletions
diff --git a/drivers/net/vrf.c b/drivers/net/vrf.c new file mode 100644 index 000000000..857b6f80a --- /dev/null +++ b/drivers/net/vrf.c @@ -0,0 +1,1519 @@ +/* + * 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> +#include <net/netns/generic.h> + +#define DRV_NAME "vrf" +#define DRV_VERSION "1.0" + +#define FIB_RULE_PREF 1000 /* default preference for FIB rules */ + +static unsigned int vrf_net_id; + +struct net_vrf { + struct rtable __rcu *rth; + struct rt6_info __rcu *rt6; +#if IS_ENABLED(CONFIG_IPV6) + struct fib6_table *fib6_table; +#endif + 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 void 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; + } +} + +/* by default VRF devices do not have a qdisc and are expected + * to be created with only a single queue. + */ +static bool qdisc_tx_is_default(const struct net_device *dev) +{ + struct netdev_queue *txq; + struct Qdisc *qdisc; + + if (dev->num_tx_queues > 1) + return false; + + txq = netdev_get_tx_queue(dev, 0); + qdisc = rcu_access_pointer(txq->qdisc); + + return !qdisc->enqueue; +} + +/* 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); + + /* 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 int vrf_ip6_local_out(struct net *net, struct sock *sk, + struct sk_buff *skb) +{ + int err; + + err = nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net, + sk, skb, NULL, skb_dst(skb)->dev, dst_output); + + if (likely(err == 1)) + err = dst_output(net, sk, skb); + + return err; +} + +static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb, + struct net_device *dev) +{ + const struct ipv6hdr *iph; + struct net *net = dev_net(skb->dev); + struct flowi6 fl6; + int ret = NET_XMIT_DROP; + struct dst_entry *dst; + struct dst_entry *dst_null = &net->ipv6.ip6_null_entry->dst; + + if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct ipv6hdr))) + goto err; + + iph = ipv6_hdr(skb); + + memset(&fl6, 0, sizeof(fl6)); + /* needed to match OIF rule */ + fl6.flowi6_oif = dev->ifindex; + fl6.flowi6_iif = LOOPBACK_IFINDEX; + fl6.daddr = iph->daddr; + fl6.saddr = iph->saddr; + fl6.flowlabel = ip6_flowinfo(iph); + fl6.flowi6_mark = skb->mark; + fl6.flowi6_proto = iph->nexthdr; + fl6.flowi6_flags = FLOWI_FLAG_SKIP_NH_OIF; + + dst = ip6_dst_lookup_flow(net, NULL, &fl6, NULL); + if (IS_ERR(dst) || 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 + */ + if (dst->dev == dev) + return vrf_local_xmit(skb, dev, dst); + + skb_dst_set(skb, dst); + + /* strip the ethernet header added for pass through VRF device */ + __skb_pull(skb, skb_network_offset(skb)); + + memset(IP6CB(skb), 0, sizeof(*IP6CB(skb))); + ret = vrf_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 + +/* based on ip_local_out; can't use it b/c the dst is switched pointing to us */ +static int vrf_ip_local_out(struct net *net, struct sock *sk, + struct sk_buff *skb) +{ + int err; + + err = nf_hook(NFPROTO_IPV4, NF_INET_LOCAL_OUT, net, sk, + skb, NULL, skb_dst(skb)->dev, dst_output); + if (likely(err == 1)) + err = dst_output(net, sk, skb); + + return err; +} + +static netdev_tx_t vrf_process_v4_outbound(struct sk_buff *skb, + struct net_device *vrf_dev) +{ + struct iphdr *ip4h; + int ret = NET_XMIT_DROP; + struct flowi4 fl4; + struct net *net = dev_net(vrf_dev); + struct rtable *rt; + + if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct iphdr))) + goto err; + + ip4h = ip_hdr(skb); + + memset(&fl4, 0, sizeof(fl4)); + /* needed to match OIF rule */ + fl4.flowi4_oif = vrf_dev->ifindex; + fl4.flowi4_iif = LOOPBACK_IFINDEX; + fl4.flowi4_tos = RT_TOS(ip4h->tos); + fl4.flowi4_flags = FLOWI_FLAG_ANYSRC | FLOWI_FLAG_SKIP_NH_OIF; + fl4.flowi4_proto = ip4h->protocol; + fl4.daddr = ip4h->daddr; + fl4.saddr = ip4h->saddr; + + rt = ip_route_output_flow(net, &fl4, NULL); + if (IS_ERR(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 + */ + if (rt->dst.dev == vrf_dev) + return vrf_local_xmit(skb, vrf_dev, &rt->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); + } + + memset(IPCB(skb), 0, sizeof(*IPCB(skb))); + ret = vrf_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) +{ + int len = skb->len; + 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 += len; + u64_stats_update_end(&dstats->syncp); + } else { + this_cpu_inc(dev->dstats->tx_drps); + } + + return ret; +} + +static void vrf_finish_direct(struct sk_buff *skb) +{ + struct net_device *vrf_dev = skb->dev; + + if (!list_empty(&vrf_dev->ptype_all) && + likely(skb_headroom(skb) >= ETH_HLEN)) { + struct ethhdr *eth = skb_push(skb, ETH_HLEN); + + ether_addr_copy(eth->h_source, vrf_dev->dev_addr); + eth_zero_addr(eth->h_dest); + eth->h_proto = skb->protocol; + + rcu_read_lock_bh(); + dev_queue_xmit_nit(skb, vrf_dev); + rcu_read_unlock_bh(); + + skb_pull(skb, ETH_HLEN); + } + + /* reset skb device */ + nf_reset(skb); +} + +#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; + + nf_reset(skb); + + 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)) { + sock_confirm_neigh(skb, neigh); + ret = neigh_output(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)); +} + +/* set dst on skb to send packet to us via dev_xmit path. Allows + * packet to go through device based features such as qdisc, netfilter + * hooks and packet sockets with skb->dev set to vrf device. + */ +static struct sk_buff *vrf_ip6_out_redirect(struct net_device *vrf_dev, + struct sk_buff *skb) +{ + struct net_vrf *vrf = netdev_priv(vrf_dev); + struct dst_entry *dst = NULL; + struct rt6_info *rt6; + + rcu_read_lock(); + + rt6 = rcu_dereference(vrf->rt6); + if (likely(rt6)) { + dst = &rt6->dst; + dst_hold(dst); + } + + rcu_read_unlock(); + + if (unlikely(!dst)) { + vrf_tx_error(vrf_dev, skb); + return NULL; + } + + skb_dst_drop(skb); + skb_dst_set(skb, dst); + + return skb; +} + +static int vrf_output6_direct_finish(struct net *net, struct sock *sk, + struct sk_buff *skb) +{ + vrf_finish_direct(skb); + + return vrf_ip6_local_out(net, sk, skb); +} + +static int vrf_output6_direct(struct net *net, struct sock *sk, + struct sk_buff *skb) +{ + int err = 1; + + skb->protocol = htons(ETH_P_IPV6); + + if (!(IPCB(skb)->flags & IPSKB_REROUTED)) + err = nf_hook(NFPROTO_IPV6, NF_INET_POST_ROUTING, net, sk, skb, + NULL, skb->dev, vrf_output6_direct_finish); + + if (likely(err == 1)) + vrf_finish_direct(skb); + + return err; +} + +static int vrf_ip6_out_direct_finish(struct net *net, struct sock *sk, + struct sk_buff *skb) +{ + int err; + + err = vrf_output6_direct(net, sk, skb); + if (likely(err == 1)) + err = vrf_ip6_local_out(net, sk, skb); + + return err; +} + +static struct sk_buff *vrf_ip6_out_direct(struct net_device *vrf_dev, + struct sock *sk, + struct sk_buff *skb) +{ + struct net *net = dev_net(vrf_dev); + int err; + + skb->dev = vrf_dev; + + err = nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net, sk, + skb, NULL, vrf_dev, vrf_ip6_out_direct_finish); + + if (likely(err == 1)) + err = vrf_output6_direct(net, sk, skb); + + if (likely(err == 1)) + return skb; + + return NULL; +} + +static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev, + struct sock *sk, + struct sk_buff *skb) +{ + /* don't divert link scope packets */ + if (rt6_need_strict(&ipv6_hdr(skb)->daddr)) + return skb; + + if (qdisc_tx_is_default(vrf_dev) || + IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) + return vrf_ip6_out_direct(vrf_dev, sk, skb); + + return vrf_ip6_out_redirect(vrf_dev, skb); +} + +/* holding rtnl */ +static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf) +{ + struct rt6_info *rt6 = rtnl_dereference(vrf->rt6); + struct net *net = dev_net(dev); + struct dst_entry *dst; + + RCU_INIT_POINTER(vrf->rt6, 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); + } +} + +static int vrf_rt6_create(struct net_device *dev) +{ + int flags = DST_HOST | DST_NOPOLICY | DST_NOXFRM; + struct net_vrf *vrf = netdev_priv(dev); + struct net *net = dev_net(dev); + struct rt6_info *rt6; + int rc = -ENOMEM; + + /* IPv6 can be CONFIG enabled and then disabled runtime */ + if (!ipv6_mod_enabled()) + return 0; + + vrf->fib6_table = fib6_new_table(net, vrf->tb_id); + if (!vrf->fib6_table) + goto out; + + /* create a dst for routing packets out a VRF device */ + rt6 = ip6_dst_alloc(net, dev, flags); + if (!rt6) + goto out; + + rt6->dst.output = vrf_output6; + + rcu_assign_pointer(vrf->rt6, rt6); + + rc = 0; +out: + return rc; +} +#else +static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev, + struct sock *sk, + struct sk_buff *skb) +{ + return skb; +} + +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; + + nf_reset(skb); + + /* 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)) { + sock_confirm_neigh(skb, neigh); + ret = neigh_output(neigh, skb); + rcu_read_unlock_bh(); + return ret; + } + + rcu_read_unlock_bh(); +err: + 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)); +} + +/* set dst on skb to send packet to us via dev_xmit path. Allows + * packet to go through device based features such as qdisc, netfilter + * hooks and packet sockets with skb->dev set to vrf device. + */ +static struct sk_buff *vrf_ip_out_redirect(struct net_device *vrf_dev, + struct sk_buff *skb) +{ + struct net_vrf *vrf = netdev_priv(vrf_dev); + struct dst_entry *dst = NULL; + struct rtable *rth; + + rcu_read_lock(); + + rth = rcu_dereference(vrf->rth); + if (likely(rth)) { + dst = &rth->dst; + dst_hold(dst); + } + + rcu_read_unlock(); + + if (unlikely(!dst)) { + vrf_tx_error(vrf_dev, skb); + return NULL; + } + + skb_dst_drop(skb); + skb_dst_set(skb, dst); + + return skb; +} + +static int vrf_output_direct_finish(struct net *net, struct sock *sk, + struct sk_buff *skb) +{ + vrf_finish_direct(skb); + + return vrf_ip_local_out(net, sk, skb); +} + +static int vrf_output_direct(struct net *net, struct sock *sk, + struct sk_buff *skb) +{ + int err = 1; + + skb->protocol = htons(ETH_P_IP); + + if (!(IPCB(skb)->flags & IPSKB_REROUTED)) + err = nf_hook(NFPROTO_IPV4, NF_INET_POST_ROUTING, net, sk, skb, + NULL, skb->dev, vrf_output_direct_finish); + + if (likely(err == 1)) + vrf_finish_direct(skb); + + return err; +} + +static int vrf_ip_out_direct_finish(struct net *net, struct sock *sk, + struct sk_buff *skb) +{ + int err; + + err = vrf_output_direct(net, sk, skb); + if (likely(err == 1)) + err = vrf_ip_local_out(net, sk, skb); + + return err; +} + +static struct sk_buff *vrf_ip_out_direct(struct net_device *vrf_dev, + struct sock *sk, + struct sk_buff *skb) +{ + struct net *net = dev_net(vrf_dev); + int err; + + skb->dev = vrf_dev; + + err = nf_hook(NFPROTO_IPV4, NF_INET_LOCAL_OUT, net, sk, + skb, NULL, vrf_dev, vrf_ip_out_direct_finish); + + if (likely(err == 1)) + err = vrf_output_direct(net, sk, skb); + + if (likely(err == 1)) + return skb; + + return NULL; +} + +static struct sk_buff *vrf_ip_out(struct net_device *vrf_dev, + struct sock *sk, + struct sk_buff *skb) +{ + /* don't divert multicast or local broadcast */ + if (ipv4_is_multicast(ip_hdr(skb)->daddr) || + ipv4_is_lbcast(ip_hdr(skb)->daddr)) + return skb; + + if (qdisc_tx_is_default(vrf_dev) || + IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED) + return vrf_ip_out_direct(vrf_dev, sk, skb); + + return vrf_ip_out_redirect(vrf_dev, skb); +} + +/* called with rcu lock held */ +static struct sk_buff *vrf_l3_out(struct net_device *vrf_dev, + struct sock *sk, + struct sk_buff *skb, + u16 proto) +{ + switch (proto) { + case AF_INET: + return vrf_ip_out(vrf_dev, sk, skb); + case AF_INET6: + return vrf_ip6_out(vrf_dev, sk, skb); + } + + return skb; +} + +/* holding rtnl */ +static void vrf_rtable_release(struct net_device *dev, struct net_vrf *vrf) +{ + struct rtable *rth = rtnl_dereference(vrf->rth); + struct net *net = dev_net(dev); + struct dst_entry *dst; + + RCU_INIT_POINTER(vrf->rth, 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); + } +} + +static int vrf_rtable_create(struct net_device *dev) +{ + struct net_vrf *vrf = netdev_priv(dev); + struct rtable *rth; + + 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; + + rth->dst.output = vrf_output; + + rcu_assign_pointer(vrf->rth, rth); + + 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, + struct netlink_ext_ack *extack) +{ + int ret; + + /* do not allow loopback device to be enslaved to a VRF. + * The vrf device acts as the loopback for the vrf. + */ + if (port_dev == dev_net(dev)->loopback_dev) { + NL_SET_ERR_MSG(extack, + "Can not enslave loopback device to a VRF"); + return -EOPNOTSUPP; + } + + port_dev->priv_flags |= IFF_L3MDEV_SLAVE; + ret = netdev_master_upper_dev_link(port_dev, dev, NULL, NULL, extack); + if (ret < 0) + goto err; + + cycle_netdev(port_dev); + + return 0; + +err: + port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE; + return ret; +} + +static int vrf_add_slave(struct net_device *dev, struct net_device *port_dev, + struct netlink_ext_ack *extack) +{ + if (netif_is_l3_master(port_dev)) { + NL_SET_ERR_MSG(extack, + "Can not enslave an L3 master device to a VRF"); + return -EINVAL; + } + + if (netif_is_l3_slave(port_dev)) + return -EINVAL; + + return do_vrf_add_slave(dev, port_dev, extack); +} + +/* 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); + + vrf_rtable_release(dev, vrf); + vrf_rt6_release(dev, vrf); + + 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 int vrf_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb) +{ + kfree_skb(skb); + return 0; +} + +static struct sk_buff *vrf_rcv_nfhook(u8 pf, unsigned int hook, + struct sk_buff *skb, + struct net_device *dev) +{ + struct net *net = dev_net(dev); + + if (nf_hook(pf, hook, net, NULL, skb, dev, NULL, vrf_rcv_finish) != 1) + skb = NULL; /* kfree_skb(skb) handled by nf code */ + + return skb; +} + +#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, + const struct sk_buff *skb, + int flags) +{ + struct net_vrf *vrf = netdev_priv(dev); + + return ip6_pol_route(net, vrf->fib6_table, ifindex, fl6, skb, 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 = { + .flowi6_iif = ifindex, + .flowi6_mark = skb->mark, + .flowi6_proto = iph->nexthdr, + .daddr = iph->daddr, + .saddr = iph->saddr, + .flowlabel = ip6_flowinfo(iph), + }; + struct net *net = dev_net(vrf_dev); + struct rt6_info *rt6; + + rt6 = vrf_ip6_route_lookup(net, vrf_dev, &fl6, ifindex, skb, + 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; + IP6CB(skb)->flags |= IP6SKB_L3SLAVE; + 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) { + vrf_rx_stats(vrf_dev, skb->len); + skb->dev = vrf_dev; + skb->skb_iif = vrf_dev->ifindex; + + if (!list_empty(&vrf_dev->ptype_all)) { + 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); + + skb = vrf_rcv_nfhook(NFPROTO_IPV6, NF_INET_PRE_ROUTING, skb, vrf_dev); +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; + IPCB(skb)->flags |= IPSKB_L3SLAVE; + + if (ipv4_is_multicast(ip_hdr(skb)->daddr)) + goto out; + + /* 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; + } + + vrf_rx_stats(vrf_dev, skb->len); + + if (!list_empty(&vrf_dev->ptype_all)) { + skb_push(skb, skb->mac_len); + dev_queue_xmit_nit(skb, vrf_dev); + skb_pull(skb, skb->mac_len); + } + + skb = vrf_rcv_nfhook(NFPROTO_IPV4, NF_INET_PRE_ROUTING, skb, vrf_dev); +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) +/* send to link-local or multicast address via interface enslaved to + * VRF device. Force lookup to VRF table without changing flow struct + */ +static struct dst_entry *vrf_link_scope_lookup(const struct net_device *dev, + struct flowi6 *fl6) +{ + struct net *net = dev_net(dev); + int flags = RT6_LOOKUP_F_IFACE; + struct dst_entry *dst = NULL; + struct rt6_info *rt; + + /* 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) { + 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, NULL, flags); + if (rt) + dst = &rt->dst; + + return dst; +} +#endif + +static const struct l3mdev_ops vrf_l3mdev_ops = { + .l3mdev_fib_table = vrf_fib_table, + .l3mdev_l3_rcv = vrf_l3_rcv, + .l3mdev_l3_out = vrf_l3_out, +#if IS_ENABLED(CONFIG_IPV6) + .l3mdev_link_scope_lookup = vrf_link_scope_lookup, +#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 */ + sz += nla_total_size(sizeof(u8)); /* FRA_PROTOCOL */ + + 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_u8(skb, FRA_PROTOCOL, RTPROT_KERNEL)) + goto nla_put_failure; + + if (nla_put_u8(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, NULL); + if (err == -EEXIST) + err = 0; + } else { + err = fib_nl_delrule(skb, nlh, NULL); + 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; + +#if IS_ENABLED(CONFIG_IP_MROUTE_MULTIPLE_TABLES) + err = vrf_fib_rule(dev, RTNL_FAMILY_IPMR, true); + if (err < 0) + goto ipmr_err; +#endif + + return 0; + +#if IS_ENABLED(CONFIG_IP_MROUTE_MULTIPLE_TABLES) +ipmr_err: + vrf_fib_rule(dev, AF_INET6, false); +#endif + +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->needs_free_netdev = true; + + /* 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 | NETIF_F_SCTP_CRC; + 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; + dev->priv_flags |= IFF_NO_RX_HANDLER; +} + +static int vrf_validate(struct nlattr *tb[], struct nlattr *data[], + struct netlink_ext_ack *extack) +{ + if (tb[IFLA_ADDRESS]) { + if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) { + NL_SET_ERR_MSG(extack, "Invalid hardware address"); + return -EINVAL; + } + if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) { + NL_SET_ERR_MSG(extack, "Invalid hardware address"); + return -EADDRNOTAVAIL; + } + } + return 0; +} + +static void vrf_dellink(struct net_device *dev, struct list_head *head) +{ + struct net_device *port_dev; + struct list_head *iter; + + netdev_for_each_lower_dev(dev, port_dev, iter) + vrf_del_slave(dev, port_dev); + + unregister_netdevice_queue(dev, head); +} + +static int vrf_newlink(struct net *src_net, struct net_device *dev, + struct nlattr *tb[], struct nlattr *data[], + struct netlink_ext_ack *extack) +{ + struct net_vrf *vrf = netdev_priv(dev); + bool *add_fib_rules; + struct net *net; + int err; + + if (!data || !data[IFLA_VRF_TABLE]) { + NL_SET_ERR_MSG(extack, "VRF table id is missing"); + return -EINVAL; + } + + vrf->tb_id = nla_get_u32(data[IFLA_VRF_TABLE]); + if (vrf->tb_id == RT_TABLE_UNSPEC) { + NL_SET_ERR_MSG_ATTR(extack, data[IFLA_VRF_TABLE], + "Invalid VRF table id"); + return -EINVAL; + } + + dev->priv_flags |= IFF_L3MDEV_MASTER; + + err = register_netdevice(dev); + if (err) + goto out; + + net = dev_net(dev); + add_fib_rules = net_generic(net, vrf_net_id); + 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, +}; + +/* Initialize per network namespace state */ +static int __net_init vrf_netns_init(struct net *net) +{ + bool *add_fib_rules = net_generic(net, vrf_net_id); + + *add_fib_rules = true; + + return 0; +} + +static struct pernet_operations vrf_net_ops __net_initdata = { + .init = vrf_netns_init, + .id = &vrf_net_id, + .size = sizeof(bool), +}; + +static int __init vrf_init_module(void) +{ + int rc; + + register_netdevice_notifier(&vrf_notifier_block); + + rc = register_pernet_subsys(&vrf_net_ops); + if (rc < 0) + goto error; + + rc = rtnl_link_register(&vrf_link_ops); + if (rc < 0) { + unregister_pernet_subsys(&vrf_net_ops); + 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); |