Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / net / ipv4 / ip_tunnel.c
diff --git a/kernel/net/ipv4/ip_tunnel.c b/kernel/net/ipv4/ip_tunnel.c
new file mode 100644 (file)
index 0000000..4c2c3ba
--- /dev/null
@@ -0,0 +1,1191 @@
+/*
+ * Copyright (c) 2013 Nicira, Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/capability.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <linux/in.h>
+#include <linux/tcp.h>
+#include <linux/udp.h>
+#include <linux/if_arp.h>
+#include <linux/mroute.h>
+#include <linux/init.h>
+#include <linux/in6.h>
+#include <linux/inetdevice.h>
+#include <linux/igmp.h>
+#include <linux/netfilter_ipv4.h>
+#include <linux/etherdevice.h>
+#include <linux/if_ether.h>
+#include <linux/if_vlan.h>
+#include <linux/rculist.h>
+#include <linux/err.h>
+
+#include <net/sock.h>
+#include <net/ip.h>
+#include <net/icmp.h>
+#include <net/protocol.h>
+#include <net/ip_tunnels.h>
+#include <net/arp.h>
+#include <net/checksum.h>
+#include <net/dsfield.h>
+#include <net/inet_ecn.h>
+#include <net/xfrm.h>
+#include <net/net_namespace.h>
+#include <net/netns/generic.h>
+#include <net/rtnetlink.h>
+#include <net/udp.h>
+
+#if IS_ENABLED(CONFIG_IPV6)
+#include <net/ipv6.h>
+#include <net/ip6_fib.h>
+#include <net/ip6_route.h>
+#endif
+
+static unsigned int ip_tunnel_hash(__be32 key, __be32 remote)
+{
+       return hash_32((__force u32)key ^ (__force u32)remote,
+                        IP_TNL_HASH_BITS);
+}
+
+static void __tunnel_dst_set(struct ip_tunnel_dst *idst,
+                            struct dst_entry *dst, __be32 saddr)
+{
+       struct dst_entry *old_dst;
+
+       dst_clone(dst);
+       old_dst = xchg((__force struct dst_entry **)&idst->dst, dst);
+       dst_release(old_dst);
+       idst->saddr = saddr;
+}
+
+static noinline void tunnel_dst_set(struct ip_tunnel *t,
+                          struct dst_entry *dst, __be32 saddr)
+{
+       __tunnel_dst_set(raw_cpu_ptr(t->dst_cache), dst, saddr);
+}
+
+static void tunnel_dst_reset(struct ip_tunnel *t)
+{
+       tunnel_dst_set(t, NULL, 0);
+}
+
+void ip_tunnel_dst_reset_all(struct ip_tunnel *t)
+{
+       int i;
+
+       for_each_possible_cpu(i)
+               __tunnel_dst_set(per_cpu_ptr(t->dst_cache, i), NULL, 0);
+}
+EXPORT_SYMBOL(ip_tunnel_dst_reset_all);
+
+static struct rtable *tunnel_rtable_get(struct ip_tunnel *t,
+                                       u32 cookie, __be32 *saddr)
+{
+       struct ip_tunnel_dst *idst;
+       struct dst_entry *dst;
+
+       rcu_read_lock();
+       idst = raw_cpu_ptr(t->dst_cache);
+       dst = rcu_dereference(idst->dst);
+       if (dst && !atomic_inc_not_zero(&dst->__refcnt))
+               dst = NULL;
+       if (dst) {
+               if (!dst->obsolete || dst->ops->check(dst, cookie)) {
+                       *saddr = idst->saddr;
+               } else {
+                       tunnel_dst_reset(t);
+                       dst_release(dst);
+                       dst = NULL;
+               }
+       }
+       rcu_read_unlock();
+       return (struct rtable *)dst;
+}
+
+static bool ip_tunnel_key_match(const struct ip_tunnel_parm *p,
+                               __be16 flags, __be32 key)
+{
+       if (p->i_flags & TUNNEL_KEY) {
+               if (flags & TUNNEL_KEY)
+                       return key == p->i_key;
+               else
+                       /* key expected, none present */
+                       return false;
+       } else
+               return !(flags & TUNNEL_KEY);
+}
+
+/* Fallback tunnel: no source, no destination, no key, no options
+
+   Tunnel hash table:
+   We require exact key match i.e. if a key is present in packet
+   it will match only tunnel with the same key; if it is not present,
+   it will match only keyless tunnel.
+
+   All keysless packets, if not matched configured keyless tunnels
+   will match fallback tunnel.
+   Given src, dst and key, find appropriate for input tunnel.
+*/
+struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn,
+                                  int link, __be16 flags,
+                                  __be32 remote, __be32 local,
+                                  __be32 key)
+{
+       unsigned int hash;
+       struct ip_tunnel *t, *cand = NULL;
+       struct hlist_head *head;
+
+       hash = ip_tunnel_hash(key, remote);
+       head = &itn->tunnels[hash];
+
+       hlist_for_each_entry_rcu(t, head, hash_node) {
+               if (local != t->parms.iph.saddr ||
+                   remote != t->parms.iph.daddr ||
+                   !(t->dev->flags & IFF_UP))
+                       continue;
+
+               if (!ip_tunnel_key_match(&t->parms, flags, key))
+                       continue;
+
+               if (t->parms.link == link)
+                       return t;
+               else
+                       cand = t;
+       }
+
+       hlist_for_each_entry_rcu(t, head, hash_node) {
+               if (remote != t->parms.iph.daddr ||
+                   t->parms.iph.saddr != 0 ||
+                   !(t->dev->flags & IFF_UP))
+                       continue;
+
+               if (!ip_tunnel_key_match(&t->parms, flags, key))
+                       continue;
+
+               if (t->parms.link == link)
+                       return t;
+               else if (!cand)
+                       cand = t;
+       }
+
+       hash = ip_tunnel_hash(key, 0);
+       head = &itn->tunnels[hash];
+
+       hlist_for_each_entry_rcu(t, head, hash_node) {
+               if ((local != t->parms.iph.saddr || t->parms.iph.daddr != 0) &&
+                   (local != t->parms.iph.daddr || !ipv4_is_multicast(local)))
+                       continue;
+
+               if (!(t->dev->flags & IFF_UP))
+                       continue;
+
+               if (!ip_tunnel_key_match(&t->parms, flags, key))
+                       continue;
+
+               if (t->parms.link == link)
+                       return t;
+               else if (!cand)
+                       cand = t;
+       }
+
+       if (flags & TUNNEL_NO_KEY)
+               goto skip_key_lookup;
+
+       hlist_for_each_entry_rcu(t, head, hash_node) {
+               if (t->parms.i_key != key ||
+                   t->parms.iph.saddr != 0 ||
+                   t->parms.iph.daddr != 0 ||
+                   !(t->dev->flags & IFF_UP))
+                       continue;
+
+               if (t->parms.link == link)
+                       return t;
+               else if (!cand)
+                       cand = t;
+       }
+
+skip_key_lookup:
+       if (cand)
+               return cand;
+
+       if (itn->fb_tunnel_dev && itn->fb_tunnel_dev->flags & IFF_UP)
+               return netdev_priv(itn->fb_tunnel_dev);
+
+
+       return NULL;
+}
+EXPORT_SYMBOL_GPL(ip_tunnel_lookup);
+
+static struct hlist_head *ip_bucket(struct ip_tunnel_net *itn,
+                                   struct ip_tunnel_parm *parms)
+{
+       unsigned int h;
+       __be32 remote;
+       __be32 i_key = parms->i_key;
+
+       if (parms->iph.daddr && !ipv4_is_multicast(parms->iph.daddr))
+               remote = parms->iph.daddr;
+       else
+               remote = 0;
+
+       if (!(parms->i_flags & TUNNEL_KEY) && (parms->i_flags & VTI_ISVTI))
+               i_key = 0;
+
+       h = ip_tunnel_hash(i_key, remote);
+       return &itn->tunnels[h];
+}
+
+static void ip_tunnel_add(struct ip_tunnel_net *itn, struct ip_tunnel *t)
+{
+       struct hlist_head *head = ip_bucket(itn, &t->parms);
+
+       hlist_add_head_rcu(&t->hash_node, head);
+}
+
+static void ip_tunnel_del(struct ip_tunnel *t)
+{
+       hlist_del_init_rcu(&t->hash_node);
+}
+
+static struct ip_tunnel *ip_tunnel_find(struct ip_tunnel_net *itn,
+                                       struct ip_tunnel_parm *parms,
+                                       int type)
+{
+       __be32 remote = parms->iph.daddr;
+       __be32 local = parms->iph.saddr;
+       __be32 key = parms->i_key;
+       __be16 flags = parms->i_flags;
+       int link = parms->link;
+       struct ip_tunnel *t = NULL;
+       struct hlist_head *head = ip_bucket(itn, parms);
+
+       hlist_for_each_entry_rcu(t, head, hash_node) {
+               if (local == t->parms.iph.saddr &&
+                   remote == t->parms.iph.daddr &&
+                   link == t->parms.link &&
+                   type == t->dev->type &&
+                   ip_tunnel_key_match(&t->parms, flags, key))
+                       break;
+       }
+       return t;
+}
+
+static struct net_device *__ip_tunnel_create(struct net *net,
+                                            const struct rtnl_link_ops *ops,
+                                            struct ip_tunnel_parm *parms)
+{
+       int err;
+       struct ip_tunnel *tunnel;
+       struct net_device *dev;
+       char name[IFNAMSIZ];
+
+       if (parms->name[0])
+               strlcpy(name, parms->name, IFNAMSIZ);
+       else {
+               if (strlen(ops->kind) > (IFNAMSIZ - 3)) {
+                       err = -E2BIG;
+                       goto failed;
+               }
+               strlcpy(name, ops->kind, IFNAMSIZ);
+               strncat(name, "%d", 2);
+       }
+
+       ASSERT_RTNL();
+       dev = alloc_netdev(ops->priv_size, name, NET_NAME_UNKNOWN, ops->setup);
+       if (!dev) {
+               err = -ENOMEM;
+               goto failed;
+       }
+       dev_net_set(dev, net);
+
+       dev->rtnl_link_ops = ops;
+
+       tunnel = netdev_priv(dev);
+       tunnel->parms = *parms;
+       tunnel->net = net;
+
+       err = register_netdevice(dev);
+       if (err)
+               goto failed_free;
+
+       return dev;
+
+failed_free:
+       free_netdev(dev);
+failed:
+       return ERR_PTR(err);
+}
+
+static inline void init_tunnel_flow(struct flowi4 *fl4,
+                                   int proto,
+                                   __be32 daddr, __be32 saddr,
+                                   __be32 key, __u8 tos, int oif)
+{
+       memset(fl4, 0, sizeof(*fl4));
+       fl4->flowi4_oif = oif;
+       fl4->daddr = daddr;
+       fl4->saddr = saddr;
+       fl4->flowi4_tos = tos;
+       fl4->flowi4_proto = proto;
+       fl4->fl4_gre_key = key;
+}
+
+static int ip_tunnel_bind_dev(struct net_device *dev)
+{
+       struct net_device *tdev = NULL;
+       struct ip_tunnel *tunnel = netdev_priv(dev);
+       const struct iphdr *iph;
+       int hlen = LL_MAX_HEADER;
+       int mtu = ETH_DATA_LEN;
+       int t_hlen = tunnel->hlen + sizeof(struct iphdr);
+
+       iph = &tunnel->parms.iph;
+
+       /* Guess output device to choose reasonable mtu and needed_headroom */
+       if (iph->daddr) {
+               struct flowi4 fl4;
+               struct rtable *rt;
+
+               init_tunnel_flow(&fl4, iph->protocol, iph->daddr,
+                                iph->saddr, tunnel->parms.o_key,
+                                RT_TOS(iph->tos), tunnel->parms.link);
+               rt = ip_route_output_key(tunnel->net, &fl4);
+
+               if (!IS_ERR(rt)) {
+                       tdev = rt->dst.dev;
+                       tunnel_dst_set(tunnel, &rt->dst, fl4.saddr);
+                       ip_rt_put(rt);
+               }
+               if (dev->type != ARPHRD_ETHER)
+                       dev->flags |= IFF_POINTOPOINT;
+       }
+
+       if (!tdev && tunnel->parms.link)
+               tdev = __dev_get_by_index(tunnel->net, tunnel->parms.link);
+
+       if (tdev) {
+               hlen = tdev->hard_header_len + tdev->needed_headroom;
+               mtu = tdev->mtu;
+       }
+
+       dev->needed_headroom = t_hlen + hlen;
+       mtu -= (dev->hard_header_len + t_hlen);
+
+       if (mtu < 68)
+               mtu = 68;
+
+       return mtu;
+}
+
+static struct ip_tunnel *ip_tunnel_create(struct net *net,
+                                         struct ip_tunnel_net *itn,
+                                         struct ip_tunnel_parm *parms)
+{
+       struct ip_tunnel *nt;
+       struct net_device *dev;
+
+       BUG_ON(!itn->fb_tunnel_dev);
+       dev = __ip_tunnel_create(net, itn->fb_tunnel_dev->rtnl_link_ops, parms);
+       if (IS_ERR(dev))
+               return ERR_CAST(dev);
+
+       dev->mtu = ip_tunnel_bind_dev(dev);
+
+       nt = netdev_priv(dev);
+       ip_tunnel_add(itn, nt);
+       return nt;
+}
+
+int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb,
+                 const struct tnl_ptk_info *tpi, bool log_ecn_error)
+{
+       struct pcpu_sw_netstats *tstats;
+       const struct iphdr *iph = ip_hdr(skb);
+       int err;
+
+#ifdef CONFIG_NET_IPGRE_BROADCAST
+       if (ipv4_is_multicast(iph->daddr)) {
+               tunnel->dev->stats.multicast++;
+               skb->pkt_type = PACKET_BROADCAST;
+       }
+#endif
+
+       if ((!(tpi->flags&TUNNEL_CSUM) &&  (tunnel->parms.i_flags&TUNNEL_CSUM)) ||
+            ((tpi->flags&TUNNEL_CSUM) && !(tunnel->parms.i_flags&TUNNEL_CSUM))) {
+               tunnel->dev->stats.rx_crc_errors++;
+               tunnel->dev->stats.rx_errors++;
+               goto drop;
+       }
+
+       if (tunnel->parms.i_flags&TUNNEL_SEQ) {
+               if (!(tpi->flags&TUNNEL_SEQ) ||
+                   (tunnel->i_seqno && (s32)(ntohl(tpi->seq) - tunnel->i_seqno) < 0)) {
+                       tunnel->dev->stats.rx_fifo_errors++;
+                       tunnel->dev->stats.rx_errors++;
+                       goto drop;
+               }
+               tunnel->i_seqno = ntohl(tpi->seq) + 1;
+       }
+
+       skb_reset_network_header(skb);
+
+       err = IP_ECN_decapsulate(iph, skb);
+       if (unlikely(err)) {
+               if (log_ecn_error)
+                       net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n",
+                                       &iph->saddr, iph->tos);
+               if (err > 1) {
+                       ++tunnel->dev->stats.rx_frame_errors;
+                       ++tunnel->dev->stats.rx_errors;
+                       goto drop;
+               }
+       }
+
+       tstats = this_cpu_ptr(tunnel->dev->tstats);
+       u64_stats_update_begin(&tstats->syncp);
+       tstats->rx_packets++;
+       tstats->rx_bytes += skb->len;
+       u64_stats_update_end(&tstats->syncp);
+
+       skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(tunnel->dev)));
+
+       if (tunnel->dev->type == ARPHRD_ETHER) {
+               skb->protocol = eth_type_trans(skb, tunnel->dev);
+               skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
+       } else {
+               skb->dev = tunnel->dev;
+       }
+
+       gro_cells_receive(&tunnel->gro_cells, skb);
+       return 0;
+
+drop:
+       kfree_skb(skb);
+       return 0;
+}
+EXPORT_SYMBOL_GPL(ip_tunnel_rcv);
+
+static int ip_encap_hlen(struct ip_tunnel_encap *e)
+{
+       const struct ip_tunnel_encap_ops *ops;
+       int hlen = -EINVAL;
+
+       if (e->type == TUNNEL_ENCAP_NONE)
+               return 0;
+
+       if (e->type >= MAX_IPTUN_ENCAP_OPS)
+               return -EINVAL;
+
+       rcu_read_lock();
+       ops = rcu_dereference(iptun_encaps[e->type]);
+       if (likely(ops && ops->encap_hlen))
+               hlen = ops->encap_hlen(e);
+       rcu_read_unlock();
+
+       return hlen;
+}
+
+const struct ip_tunnel_encap_ops __rcu *
+               iptun_encaps[MAX_IPTUN_ENCAP_OPS] __read_mostly;
+
+int ip_tunnel_encap_add_ops(const struct ip_tunnel_encap_ops *ops,
+                           unsigned int num)
+{
+       if (num >= MAX_IPTUN_ENCAP_OPS)
+               return -ERANGE;
+
+       return !cmpxchg((const struct ip_tunnel_encap_ops **)
+                       &iptun_encaps[num],
+                       NULL, ops) ? 0 : -1;
+}
+EXPORT_SYMBOL(ip_tunnel_encap_add_ops);
+
+int ip_tunnel_encap_del_ops(const struct ip_tunnel_encap_ops *ops,
+                           unsigned int num)
+{
+       int ret;
+
+       if (num >= MAX_IPTUN_ENCAP_OPS)
+               return -ERANGE;
+
+       ret = (cmpxchg((const struct ip_tunnel_encap_ops **)
+                      &iptun_encaps[num],
+                      ops, NULL) == ops) ? 0 : -1;
+
+       synchronize_net();
+
+       return ret;
+}
+EXPORT_SYMBOL(ip_tunnel_encap_del_ops);
+
+int ip_tunnel_encap_setup(struct ip_tunnel *t,
+                         struct ip_tunnel_encap *ipencap)
+{
+       int hlen;
+
+       memset(&t->encap, 0, sizeof(t->encap));
+
+       hlen = ip_encap_hlen(ipencap);
+       if (hlen < 0)
+               return hlen;
+
+       t->encap.type = ipencap->type;
+       t->encap.sport = ipencap->sport;
+       t->encap.dport = ipencap->dport;
+       t->encap.flags = ipencap->flags;
+
+       t->encap_hlen = hlen;
+       t->hlen = t->encap_hlen + t->tun_hlen;
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(ip_tunnel_encap_setup);
+
+int ip_tunnel_encap(struct sk_buff *skb, struct ip_tunnel *t,
+                   u8 *protocol, struct flowi4 *fl4)
+{
+       const struct ip_tunnel_encap_ops *ops;
+       int ret = -EINVAL;
+
+       if (t->encap.type == TUNNEL_ENCAP_NONE)
+               return 0;
+
+       if (t->encap.type >= MAX_IPTUN_ENCAP_OPS)
+               return -EINVAL;
+
+       rcu_read_lock();
+       ops = rcu_dereference(iptun_encaps[t->encap.type]);
+       if (likely(ops && ops->build_header))
+               ret = ops->build_header(skb, &t->encap, protocol, fl4);
+       rcu_read_unlock();
+
+       return ret;
+}
+EXPORT_SYMBOL(ip_tunnel_encap);
+
+static int tnl_update_pmtu(struct net_device *dev, struct sk_buff *skb,
+                           struct rtable *rt, __be16 df)
+{
+       struct ip_tunnel *tunnel = netdev_priv(dev);
+       int pkt_size = skb->len - tunnel->hlen - dev->hard_header_len;
+       int mtu;
+
+       if (df)
+               mtu = dst_mtu(&rt->dst) - dev->hard_header_len
+                                       - sizeof(struct iphdr) - tunnel->hlen;
+       else
+               mtu = skb_dst(skb) ? dst_mtu(skb_dst(skb)) : dev->mtu;
+
+       if (skb_dst(skb))
+               skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
+
+       if (skb->protocol == htons(ETH_P_IP)) {
+               if (!skb_is_gso(skb) &&
+                   (df & htons(IP_DF)) && mtu < pkt_size) {
+                       memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
+                       icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
+                       return -E2BIG;
+               }
+       }
+#if IS_ENABLED(CONFIG_IPV6)
+       else if (skb->protocol == htons(ETH_P_IPV6)) {
+               struct rt6_info *rt6 = (struct rt6_info *)skb_dst(skb);
+
+               if (rt6 && mtu < dst_mtu(skb_dst(skb)) &&
+                          mtu >= IPV6_MIN_MTU) {
+                       if ((tunnel->parms.iph.daddr &&
+                           !ipv4_is_multicast(tunnel->parms.iph.daddr)) ||
+                           rt6->rt6i_dst.plen == 128) {
+                               rt6->rt6i_flags |= RTF_MODIFIED;
+                               dst_metric_set(skb_dst(skb), RTAX_MTU, mtu);
+                       }
+               }
+
+               if (!skb_is_gso(skb) && mtu >= IPV6_MIN_MTU &&
+                                       mtu < pkt_size) {
+                       icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
+                       return -E2BIG;
+               }
+       }
+#endif
+       return 0;
+}
+
+void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
+                   const struct iphdr *tnl_params, u8 protocol)
+{
+       struct ip_tunnel *tunnel = netdev_priv(dev);
+       const struct iphdr *inner_iph;
+       struct flowi4 fl4;
+       u8     tos, ttl;
+       __be16 df;
+       struct rtable *rt;              /* Route to the other host */
+       unsigned int max_headroom;      /* The extra header space needed */
+       __be32 dst;
+       int err;
+       bool connected;
+
+       inner_iph = (const struct iphdr *)skb_inner_network_header(skb);
+       connected = (tunnel->parms.iph.daddr != 0);
+
+       dst = tnl_params->daddr;
+       if (dst == 0) {
+               /* NBMA tunnel */
+
+               if (!skb_dst(skb)) {
+                       dev->stats.tx_fifo_errors++;
+                       goto tx_error;
+               }
+
+               if (skb->protocol == htons(ETH_P_IP)) {
+                       rt = skb_rtable(skb);
+                       dst = rt_nexthop(rt, inner_iph->daddr);
+               }
+#if IS_ENABLED(CONFIG_IPV6)
+               else if (skb->protocol == htons(ETH_P_IPV6)) {
+                       const struct in6_addr *addr6;
+                       struct neighbour *neigh;
+                       bool do_tx_error_icmp;
+                       int addr_type;
+
+                       neigh = dst_neigh_lookup(skb_dst(skb),
+                                                &ipv6_hdr(skb)->daddr);
+                       if (!neigh)
+                               goto tx_error;
+
+                       addr6 = (const struct in6_addr *)&neigh->primary_key;
+                       addr_type = ipv6_addr_type(addr6);
+
+                       if (addr_type == IPV6_ADDR_ANY) {
+                               addr6 = &ipv6_hdr(skb)->daddr;
+                               addr_type = ipv6_addr_type(addr6);
+                       }
+
+                       if ((addr_type & IPV6_ADDR_COMPATv4) == 0)
+                               do_tx_error_icmp = true;
+                       else {
+                               do_tx_error_icmp = false;
+                               dst = addr6->s6_addr32[3];
+                       }
+                       neigh_release(neigh);
+                       if (do_tx_error_icmp)
+                               goto tx_error_icmp;
+               }
+#endif
+               else
+                       goto tx_error;
+
+               connected = false;
+       }
+
+       tos = tnl_params->tos;
+       if (tos & 0x1) {
+               tos &= ~0x1;
+               if (skb->protocol == htons(ETH_P_IP)) {
+                       tos = inner_iph->tos;
+                       connected = false;
+               } else if (skb->protocol == htons(ETH_P_IPV6)) {
+                       tos = ipv6_get_dsfield((const struct ipv6hdr *)inner_iph);
+                       connected = false;
+               }
+       }
+
+       init_tunnel_flow(&fl4, protocol, dst, tnl_params->saddr,
+                        tunnel->parms.o_key, RT_TOS(tos), tunnel->parms.link);
+
+       if (ip_tunnel_encap(skb, tunnel, &protocol, &fl4) < 0)
+               goto tx_error;
+
+       rt = connected ? tunnel_rtable_get(tunnel, 0, &fl4.saddr) : NULL;
+
+       if (!rt) {
+               rt = ip_route_output_key(tunnel->net, &fl4);
+
+               if (IS_ERR(rt)) {
+                       dev->stats.tx_carrier_errors++;
+                       goto tx_error;
+               }
+               if (connected)
+                       tunnel_dst_set(tunnel, &rt->dst, fl4.saddr);
+       }
+
+       if (rt->dst.dev == dev) {
+               ip_rt_put(rt);
+               dev->stats.collisions++;
+               goto tx_error;
+       }
+
+       if (tnl_update_pmtu(dev, skb, rt, tnl_params->frag_off)) {
+               ip_rt_put(rt);
+               goto tx_error;
+       }
+
+       if (tunnel->err_count > 0) {
+               if (time_before(jiffies,
+                               tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
+                       tunnel->err_count--;
+
+                       memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
+                       dst_link_failure(skb);
+               } else
+                       tunnel->err_count = 0;
+       }
+
+       tos = ip_tunnel_ecn_encap(tos, inner_iph, skb);
+       ttl = tnl_params->ttl;
+       if (ttl == 0) {
+               if (skb->protocol == htons(ETH_P_IP))
+                       ttl = inner_iph->ttl;
+#if IS_ENABLED(CONFIG_IPV6)
+               else if (skb->protocol == htons(ETH_P_IPV6))
+                       ttl = ((const struct ipv6hdr *)inner_iph)->hop_limit;
+#endif
+               else
+                       ttl = ip4_dst_hoplimit(&rt->dst);
+       }
+
+       df = tnl_params->frag_off;
+       if (skb->protocol == htons(ETH_P_IP))
+               df |= (inner_iph->frag_off&htons(IP_DF));
+
+       max_headroom = LL_RESERVED_SPACE(rt->dst.dev) + sizeof(struct iphdr)
+                       + rt->dst.header_len + ip_encap_hlen(&tunnel->encap);
+       if (max_headroom > dev->needed_headroom)
+               dev->needed_headroom = max_headroom;
+
+       if (skb_cow_head(skb, dev->needed_headroom)) {
+               ip_rt_put(rt);
+               dev->stats.tx_dropped++;
+               kfree_skb(skb);
+               return;
+       }
+
+       err = iptunnel_xmit(NULL, rt, skb, fl4.saddr, fl4.daddr, protocol,
+                           tos, ttl, df, !net_eq(tunnel->net, dev_net(dev)));
+       iptunnel_xmit_stats(err, &dev->stats, dev->tstats);
+
+       return;
+
+#if IS_ENABLED(CONFIG_IPV6)
+tx_error_icmp:
+       dst_link_failure(skb);
+#endif
+tx_error:
+       dev->stats.tx_errors++;
+       kfree_skb(skb);
+}
+EXPORT_SYMBOL_GPL(ip_tunnel_xmit);
+
+static void ip_tunnel_update(struct ip_tunnel_net *itn,
+                            struct ip_tunnel *t,
+                            struct net_device *dev,
+                            struct ip_tunnel_parm *p,
+                            bool set_mtu)
+{
+       ip_tunnel_del(t);
+       t->parms.iph.saddr = p->iph.saddr;
+       t->parms.iph.daddr = p->iph.daddr;
+       t->parms.i_key = p->i_key;
+       t->parms.o_key = p->o_key;
+       if (dev->type != ARPHRD_ETHER) {
+               memcpy(dev->dev_addr, &p->iph.saddr, 4);
+               memcpy(dev->broadcast, &p->iph.daddr, 4);
+       }
+       ip_tunnel_add(itn, t);
+
+       t->parms.iph.ttl = p->iph.ttl;
+       t->parms.iph.tos = p->iph.tos;
+       t->parms.iph.frag_off = p->iph.frag_off;
+
+       if (t->parms.link != p->link) {
+               int mtu;
+
+               t->parms.link = p->link;
+               mtu = ip_tunnel_bind_dev(dev);
+               if (set_mtu)
+                       dev->mtu = mtu;
+       }
+       ip_tunnel_dst_reset_all(t);
+       netdev_state_change(dev);
+}
+
+int ip_tunnel_ioctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd)
+{
+       int err = 0;
+       struct ip_tunnel *t = netdev_priv(dev);
+       struct net *net = t->net;
+       struct ip_tunnel_net *itn = net_generic(net, t->ip_tnl_net_id);
+
+       BUG_ON(!itn->fb_tunnel_dev);
+       switch (cmd) {
+       case SIOCGETTUNNEL:
+               if (dev == itn->fb_tunnel_dev) {
+                       t = ip_tunnel_find(itn, p, itn->fb_tunnel_dev->type);
+                       if (!t)
+                               t = netdev_priv(dev);
+               }
+               memcpy(p, &t->parms, sizeof(*p));
+               break;
+
+       case SIOCADDTUNNEL:
+       case SIOCCHGTUNNEL:
+               err = -EPERM;
+               if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
+                       goto done;
+               if (p->iph.ttl)
+                       p->iph.frag_off |= htons(IP_DF);
+               if (!(p->i_flags & VTI_ISVTI)) {
+                       if (!(p->i_flags & TUNNEL_KEY))
+                               p->i_key = 0;
+                       if (!(p->o_flags & TUNNEL_KEY))
+                               p->o_key = 0;
+               }
+
+               t = ip_tunnel_find(itn, p, itn->fb_tunnel_dev->type);
+
+               if (cmd == SIOCADDTUNNEL) {
+                       if (!t) {
+                               t = ip_tunnel_create(net, itn, p);
+                               err = PTR_ERR_OR_ZERO(t);
+                               break;
+                       }
+
+                       err = -EEXIST;
+                       break;
+               }
+               if (dev != itn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
+                       if (t) {
+                               if (t->dev != dev) {
+                                       err = -EEXIST;
+                                       break;
+                               }
+                       } else {
+                               unsigned int nflags = 0;
+
+                               if (ipv4_is_multicast(p->iph.daddr))
+                                       nflags = IFF_BROADCAST;
+                               else if (p->iph.daddr)
+                                       nflags = IFF_POINTOPOINT;
+
+                               if ((dev->flags^nflags)&(IFF_POINTOPOINT|IFF_BROADCAST)) {
+                                       err = -EINVAL;
+                                       break;
+                               }
+
+                               t = netdev_priv(dev);
+                       }
+               }
+
+               if (t) {
+                       err = 0;
+                       ip_tunnel_update(itn, t, dev, p, true);
+               } else {
+                       err = -ENOENT;
+               }
+               break;
+
+       case SIOCDELTUNNEL:
+               err = -EPERM;
+               if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
+                       goto done;
+
+               if (dev == itn->fb_tunnel_dev) {
+                       err = -ENOENT;
+                       t = ip_tunnel_find(itn, p, itn->fb_tunnel_dev->type);
+                       if (!t)
+                               goto done;
+                       err = -EPERM;
+                       if (t == netdev_priv(itn->fb_tunnel_dev))
+                               goto done;
+                       dev = t->dev;
+               }
+               unregister_netdevice(dev);
+               err = 0;
+               break;
+
+       default:
+               err = -EINVAL;
+       }
+
+done:
+       return err;
+}
+EXPORT_SYMBOL_GPL(ip_tunnel_ioctl);
+
+int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu)
+{
+       struct ip_tunnel *tunnel = netdev_priv(dev);
+       int t_hlen = tunnel->hlen + sizeof(struct iphdr);
+
+       if (new_mtu < 68 ||
+           new_mtu > 0xFFF8 - dev->hard_header_len - t_hlen)
+               return -EINVAL;
+       dev->mtu = new_mtu;
+       return 0;
+}
+EXPORT_SYMBOL_GPL(ip_tunnel_change_mtu);
+
+static void ip_tunnel_dev_free(struct net_device *dev)
+{
+       struct ip_tunnel *tunnel = netdev_priv(dev);
+
+       gro_cells_destroy(&tunnel->gro_cells);
+       free_percpu(tunnel->dst_cache);
+       free_percpu(dev->tstats);
+       free_netdev(dev);
+}
+
+void ip_tunnel_dellink(struct net_device *dev, struct list_head *head)
+{
+       struct ip_tunnel *tunnel = netdev_priv(dev);
+       struct ip_tunnel_net *itn;
+
+       itn = net_generic(tunnel->net, tunnel->ip_tnl_net_id);
+
+       if (itn->fb_tunnel_dev != dev) {
+               ip_tunnel_del(netdev_priv(dev));
+               unregister_netdevice_queue(dev, head);
+       }
+}
+EXPORT_SYMBOL_GPL(ip_tunnel_dellink);
+
+struct net *ip_tunnel_get_link_net(const struct net_device *dev)
+{
+       struct ip_tunnel *tunnel = netdev_priv(dev);
+
+       return tunnel->net;
+}
+EXPORT_SYMBOL(ip_tunnel_get_link_net);
+
+int ip_tunnel_get_iflink(const struct net_device *dev)
+{
+       struct ip_tunnel *tunnel = netdev_priv(dev);
+
+       return tunnel->parms.link;
+}
+EXPORT_SYMBOL(ip_tunnel_get_iflink);
+
+int ip_tunnel_init_net(struct net *net, int ip_tnl_net_id,
+                                 struct rtnl_link_ops *ops, char *devname)
+{
+       struct ip_tunnel_net *itn = net_generic(net, ip_tnl_net_id);
+       struct ip_tunnel_parm parms;
+       unsigned int i;
+
+       for (i = 0; i < IP_TNL_HASH_SIZE; i++)
+               INIT_HLIST_HEAD(&itn->tunnels[i]);
+
+       if (!ops) {
+               itn->fb_tunnel_dev = NULL;
+               return 0;
+       }
+
+       memset(&parms, 0, sizeof(parms));
+       if (devname)
+               strlcpy(parms.name, devname, IFNAMSIZ);
+
+       rtnl_lock();
+       itn->fb_tunnel_dev = __ip_tunnel_create(net, ops, &parms);
+       /* FB netdevice is special: we have one, and only one per netns.
+        * Allowing to move it to another netns is clearly unsafe.
+        */
+       if (!IS_ERR(itn->fb_tunnel_dev)) {
+               itn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
+               itn->fb_tunnel_dev->mtu = ip_tunnel_bind_dev(itn->fb_tunnel_dev);
+               ip_tunnel_add(itn, netdev_priv(itn->fb_tunnel_dev));
+       }
+       rtnl_unlock();
+
+       return PTR_ERR_OR_ZERO(itn->fb_tunnel_dev);
+}
+EXPORT_SYMBOL_GPL(ip_tunnel_init_net);
+
+static void ip_tunnel_destroy(struct ip_tunnel_net *itn, struct list_head *head,
+                             struct rtnl_link_ops *ops)
+{
+       struct net *net = dev_net(itn->fb_tunnel_dev);
+       struct net_device *dev, *aux;
+       int h;
+
+       for_each_netdev_safe(net, dev, aux)
+               if (dev->rtnl_link_ops == ops)
+                       unregister_netdevice_queue(dev, head);
+
+       for (h = 0; h < IP_TNL_HASH_SIZE; h++) {
+               struct ip_tunnel *t;
+               struct hlist_node *n;
+               struct hlist_head *thead = &itn->tunnels[h];
+
+               hlist_for_each_entry_safe(t, n, thead, hash_node)
+                       /* If dev is in the same netns, it has already
+                        * been added to the list by the previous loop.
+                        */
+                       if (!net_eq(dev_net(t->dev), net))
+                               unregister_netdevice_queue(t->dev, head);
+       }
+}
+
+void ip_tunnel_delete_net(struct ip_tunnel_net *itn, struct rtnl_link_ops *ops)
+{
+       LIST_HEAD(list);
+
+       rtnl_lock();
+       ip_tunnel_destroy(itn, &list, ops);
+       unregister_netdevice_many(&list);
+       rtnl_unlock();
+}
+EXPORT_SYMBOL_GPL(ip_tunnel_delete_net);
+
+int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[],
+                     struct ip_tunnel_parm *p)
+{
+       struct ip_tunnel *nt;
+       struct net *net = dev_net(dev);
+       struct ip_tunnel_net *itn;
+       int mtu;
+       int err;
+
+       nt = netdev_priv(dev);
+       itn = net_generic(net, nt->ip_tnl_net_id);
+
+       if (ip_tunnel_find(itn, p, dev->type))
+               return -EEXIST;
+
+       nt->net = net;
+       nt->parms = *p;
+       err = register_netdevice(dev);
+       if (err)
+               goto out;
+
+       if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
+               eth_hw_addr_random(dev);
+
+       mtu = ip_tunnel_bind_dev(dev);
+       if (!tb[IFLA_MTU])
+               dev->mtu = mtu;
+
+       ip_tunnel_add(itn, nt);
+
+out:
+       return err;
+}
+EXPORT_SYMBOL_GPL(ip_tunnel_newlink);
+
+int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[],
+                        struct ip_tunnel_parm *p)
+{
+       struct ip_tunnel *t;
+       struct ip_tunnel *tunnel = netdev_priv(dev);
+       struct net *net = tunnel->net;
+       struct ip_tunnel_net *itn = net_generic(net, tunnel->ip_tnl_net_id);
+
+       if (dev == itn->fb_tunnel_dev)
+               return -EINVAL;
+
+       t = ip_tunnel_find(itn, p, dev->type);
+
+       if (t) {
+               if (t->dev != dev)
+                       return -EEXIST;
+       } else {
+               t = tunnel;
+
+               if (dev->type != ARPHRD_ETHER) {
+                       unsigned int nflags = 0;
+
+                       if (ipv4_is_multicast(p->iph.daddr))
+                               nflags = IFF_BROADCAST;
+                       else if (p->iph.daddr)
+                               nflags = IFF_POINTOPOINT;
+
+                       if ((dev->flags ^ nflags) &
+                           (IFF_POINTOPOINT | IFF_BROADCAST))
+                               return -EINVAL;
+               }
+       }
+
+       ip_tunnel_update(itn, t, dev, p, !tb[IFLA_MTU]);
+       return 0;
+}
+EXPORT_SYMBOL_GPL(ip_tunnel_changelink);
+
+int ip_tunnel_init(struct net_device *dev)
+{
+       struct ip_tunnel *tunnel = netdev_priv(dev);
+       struct iphdr *iph = &tunnel->parms.iph;
+       int err;
+
+       dev->destructor = ip_tunnel_dev_free;
+       dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
+       if (!dev->tstats)
+               return -ENOMEM;
+
+       tunnel->dst_cache = alloc_percpu(struct ip_tunnel_dst);
+       if (!tunnel->dst_cache) {
+               free_percpu(dev->tstats);
+               return -ENOMEM;
+       }
+
+       err = gro_cells_init(&tunnel->gro_cells, dev);
+       if (err) {
+               free_percpu(tunnel->dst_cache);
+               free_percpu(dev->tstats);
+               return err;
+       }
+
+       tunnel->dev = dev;
+       tunnel->net = dev_net(dev);
+       strcpy(tunnel->parms.name, dev->name);
+       iph->version            = 4;
+       iph->ihl                = 5;
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(ip_tunnel_init);
+
+void ip_tunnel_uninit(struct net_device *dev)
+{
+       struct ip_tunnel *tunnel = netdev_priv(dev);
+       struct net *net = tunnel->net;
+       struct ip_tunnel_net *itn;
+
+       itn = net_generic(net, tunnel->ip_tnl_net_id);
+       /* fb_tunnel_dev will be unregisted in net-exit call. */
+       if (itn->fb_tunnel_dev != dev)
+               ip_tunnel_del(netdev_priv(dev));
+
+       ip_tunnel_dst_reset_all(tunnel);
+}
+EXPORT_SYMBOL_GPL(ip_tunnel_uninit);
+
+/* Do least required initialization, rest of init is done in tunnel_init call */
+void ip_tunnel_setup(struct net_device *dev, int net_id)
+{
+       struct ip_tunnel *tunnel = netdev_priv(dev);
+       tunnel->ip_tnl_net_id = net_id;
+}
+EXPORT_SYMBOL_GPL(ip_tunnel_setup);
+
+MODULE_LICENSE("GPL");