]> Pileus Git - ~andy/linux/blobdiff - net/ipv4/ip_gre.c
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wirel...
[~andy/linux] / net / ipv4 / ip_gre.c
index 91d66dbde9c05cd05c4e8489a4abd317b378230e..c625e4dad4b05066d92fe02d1778b555234d0f2a 100644 (file)
@@ -37,7 +37,7 @@
 #include <net/ip.h>
 #include <net/icmp.h>
 #include <net/protocol.h>
-#include <net/ipip.h>
+#include <net/ip_tunnels.h>
 #include <net/arp.h>
 #include <net/checksum.h>
 #include <net/dsfield.h>
    fatal route to network, even if it were you who configured
    fatal static route: you are innocent. :-)
 
-
-
-   3. Really, ipv4/ipip.c, ipv4/ip_gre.c and ipv6/sit.c contain
-   practically identical code. It would be good to glue them
-   together, but it is not very evident, how to make them modular.
-   sit is integral part of IPv6, ipip and gre are naturally modular.
-   We could extract common parts (hash table, ioctl etc)
-   to a separate module (ip_tunnel.c).
-
    Alexey Kuznetsov.
  */
 
@@ -126,400 +117,137 @@ MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
 
 static struct rtnl_link_ops ipgre_link_ops __read_mostly;
 static int ipgre_tunnel_init(struct net_device *dev);
-static void ipgre_tunnel_setup(struct net_device *dev);
-static int ipgre_tunnel_bind_dev(struct net_device *dev);
-
-/* Fallback tunnel: no source, no destination, no key, no options */
-
-#define HASH_SIZE  16
 
 static int ipgre_net_id __read_mostly;
-struct ipgre_net {
-       struct ip_tunnel __rcu *tunnels[4][HASH_SIZE];
-
-       struct net_device *fb_tunnel_dev;
-};
-
-/* Tunnel hash table */
-
-/*
-   4 hash tables:
-
-   3: (remote,local)
-   2: (remote,*)
-   1: (*,local)
-   0: (*,*)
+static int gre_tap_net_id __read_mostly;
 
-   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.
- */
+static __sum16 check_checksum(struct sk_buff *skb)
+{
+       __sum16 csum = 0;
 
-#define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF)
+       switch (skb->ip_summed) {
+       case CHECKSUM_COMPLETE:
+               csum = csum_fold(skb->csum);
 
-#define tunnels_r_l    tunnels[3]
-#define tunnels_r      tunnels[2]
-#define tunnels_l      tunnels[1]
-#define tunnels_wc     tunnels[0]
+               if (!csum)
+                       break;
+               /* Fall through. */
 
-static struct rtnl_link_stats64 *ipgre_get_stats64(struct net_device *dev,
-                                                  struct rtnl_link_stats64 *tot)
-{
-       int i;
-
-       for_each_possible_cpu(i) {
-               const struct pcpu_tstats *tstats = per_cpu_ptr(dev->tstats, i);
-               u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
-               unsigned int start;
-
-               do {
-                       start = u64_stats_fetch_begin_bh(&tstats->syncp);
-                       rx_packets = tstats->rx_packets;
-                       tx_packets = tstats->tx_packets;
-                       rx_bytes = tstats->rx_bytes;
-                       tx_bytes = tstats->tx_bytes;
-               } while (u64_stats_fetch_retry_bh(&tstats->syncp, start));
-
-               tot->rx_packets += rx_packets;
-               tot->tx_packets += tx_packets;
-               tot->rx_bytes   += rx_bytes;
-               tot->tx_bytes   += tx_bytes;
+       case CHECKSUM_NONE:
+               skb->csum = 0;
+               csum = __skb_checksum_complete(skb);
+               skb->ip_summed = CHECKSUM_COMPLETE;
+               break;
        }
 
-       tot->multicast = dev->stats.multicast;
-       tot->rx_crc_errors = dev->stats.rx_crc_errors;
-       tot->rx_fifo_errors = dev->stats.rx_fifo_errors;
-       tot->rx_length_errors = dev->stats.rx_length_errors;
-       tot->rx_frame_errors = dev->stats.rx_frame_errors;
-       tot->rx_errors = dev->stats.rx_errors;
-
-       tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
-       tot->tx_carrier_errors = dev->stats.tx_carrier_errors;
-       tot->tx_dropped = dev->stats.tx_dropped;
-       tot->tx_aborted_errors = dev->stats.tx_aborted_errors;
-       tot->tx_errors = dev->stats.tx_errors;
-
-       return tot;
+       return csum;
 }
 
-/* Does key in tunnel parameters match packet */
-static bool ipgre_key_match(const struct ip_tunnel_parm *p,
-                           __be16 flags, __be32 key)
+static int ip_gre_calc_hlen(__be16 o_flags)
 {
-       if (p->i_flags & GRE_KEY) {
-               if (flags & GRE_KEY)
-                       return key == p->i_key;
-               else
-                       return false;   /* key expected, none present */
-       } else
-               return !(flags & GRE_KEY);
-}
+       int addend = 4;
 
-/* Given src, dst and key, find appropriate for input tunnel. */
+       if (o_flags&TUNNEL_CSUM)
+               addend += 4;
+       if (o_flags&TUNNEL_KEY)
+               addend += 4;
+       if (o_flags&TUNNEL_SEQ)
+               addend += 4;
+       return addend;
+}
 
-static struct ip_tunnel *ipgre_tunnel_lookup(struct net_device *dev,
-                                            __be32 remote, __be32 local,
-                                            __be16 flags, __be32 key,
-                                            __be16 gre_proto)
+static int parse_gre_header(struct sk_buff *skb, struct tnl_ptk_info *tpi,
+                           bool *csum_err, int *hdr_len)
 {
-       struct net *net = dev_net(dev);
-       int link = dev->ifindex;
-       unsigned int h0 = HASH(remote);
-       unsigned int h1 = HASH(key);
-       struct ip_tunnel *t, *cand = NULL;
-       struct ipgre_net *ign = net_generic(net, ipgre_net_id);
-       int dev_type = (gre_proto == htons(ETH_P_TEB)) ?
-                      ARPHRD_ETHER : ARPHRD_IPGRE;
-       int score, cand_score = 4;
-
-       for_each_ip_tunnel_rcu(t, ign->tunnels_r_l[h0 ^ h1]) {
-               if (local != t->parms.iph.saddr ||
-                   remote != t->parms.iph.daddr ||
-                   !(t->dev->flags & IFF_UP))
-                       continue;
-
-               if (!ipgre_key_match(&t->parms, flags, key))
-                       continue;
-
-               if (t->dev->type != ARPHRD_IPGRE &&
-                   t->dev->type != dev_type)
-                       continue;
-
-               score = 0;
-               if (t->parms.link != link)
-                       score |= 1;
-               if (t->dev->type != dev_type)
-                       score |= 2;
-               if (score == 0)
-                       return t;
-
-               if (score < cand_score) {
-                       cand = t;
-                       cand_score = score;
-               }
-       }
+       unsigned int ip_hlen = ip_hdrlen(skb);
+       const struct gre_base_hdr *greh;
+       __be32 *options;
 
-       for_each_ip_tunnel_rcu(t, ign->tunnels_r[h0 ^ h1]) {
-               if (remote != t->parms.iph.daddr ||
-                   !(t->dev->flags & IFF_UP))
-                       continue;
-
-               if (!ipgre_key_match(&t->parms, flags, key))
-                       continue;
-
-               if (t->dev->type != ARPHRD_IPGRE &&
-                   t->dev->type != dev_type)
-                       continue;
-
-               score = 0;
-               if (t->parms.link != link)
-                       score |= 1;
-               if (t->dev->type != dev_type)
-                       score |= 2;
-               if (score == 0)
-                       return t;
-
-               if (score < cand_score) {
-                       cand = t;
-                       cand_score = score;
-               }
-       }
+       if (unlikely(!pskb_may_pull(skb, sizeof(struct gre_base_hdr))))
+               return -EINVAL;
 
-       for_each_ip_tunnel_rcu(t, ign->tunnels_l[h1]) {
-               if ((local != t->parms.iph.saddr &&
-                    (local != t->parms.iph.daddr ||
-                     !ipv4_is_multicast(local))) ||
-                   !(t->dev->flags & IFF_UP))
-                       continue;
-
-               if (!ipgre_key_match(&t->parms, flags, key))
-                       continue;
-
-               if (t->dev->type != ARPHRD_IPGRE &&
-                   t->dev->type != dev_type)
-                       continue;
-
-               score = 0;
-               if (t->parms.link != link)
-                       score |= 1;
-               if (t->dev->type != dev_type)
-                       score |= 2;
-               if (score == 0)
-                       return t;
-
-               if (score < cand_score) {
-                       cand = t;
-                       cand_score = score;
-               }
-       }
+       greh = (struct gre_base_hdr *)(skb_network_header(skb) + ip_hlen);
+       if (unlikely(greh->flags & (GRE_VERSION | GRE_ROUTING)))
+               return -EINVAL;
 
-       for_each_ip_tunnel_rcu(t, ign->tunnels_wc[h1]) {
-               if (t->parms.i_key != key ||
-                   !(t->dev->flags & IFF_UP))
-                       continue;
-
-               if (t->dev->type != ARPHRD_IPGRE &&
-                   t->dev->type != dev_type)
-                       continue;
-
-               score = 0;
-               if (t->parms.link != link)
-                       score |= 1;
-               if (t->dev->type != dev_type)
-                       score |= 2;
-               if (score == 0)
-                       return t;
-
-               if (score < cand_score) {
-                       cand = t;
-                       cand_score = score;
-               }
-       }
+       tpi->flags = gre_flags_to_tnl_flags(greh->flags);
+       *hdr_len = ip_gre_calc_hlen(tpi->flags);
 
-       if (cand != NULL)
-               return cand;
+       if (!pskb_may_pull(skb, *hdr_len))
+               return -EINVAL;
 
-       dev = ign->fb_tunnel_dev;
-       if (dev->flags & IFF_UP)
-               return netdev_priv(dev);
+       greh = (struct gre_base_hdr *)(skb_network_header(skb) + ip_hlen);
 
-       return NULL;
-}
+       tpi->proto = greh->protocol;
 
-static struct ip_tunnel __rcu **__ipgre_bucket(struct ipgre_net *ign,
-               struct ip_tunnel_parm *parms)
-{
-       __be32 remote = parms->iph.daddr;
-       __be32 local = parms->iph.saddr;
-       __be32 key = parms->i_key;
-       unsigned int h = HASH(key);
-       int prio = 0;
-
-       if (local)
-               prio |= 1;
-       if (remote && !ipv4_is_multicast(remote)) {
-               prio |= 2;
-               h ^= HASH(remote);
+       options = (__be32 *)(greh + 1);
+       if (greh->flags & GRE_CSUM) {
+               if (check_checksum(skb)) {
+                       *csum_err = true;
+                       return -EINVAL;
+               }
+               options++;
        }
 
-       return &ign->tunnels[prio][h];
-}
-
-static inline struct ip_tunnel __rcu **ipgre_bucket(struct ipgre_net *ign,
-               struct ip_tunnel *t)
-{
-       return __ipgre_bucket(ign, &t->parms);
-}
-
-static void ipgre_tunnel_link(struct ipgre_net *ign, struct ip_tunnel *t)
-{
-       struct ip_tunnel __rcu **tp = ipgre_bucket(ign, t);
+       if (greh->flags & GRE_KEY) {
+               tpi->key = *options;
+               options++;
+       } else
+               tpi->key = 0;
 
-       rcu_assign_pointer(t->next, rtnl_dereference(*tp));
-       rcu_assign_pointer(*tp, t);
-}
+       if (unlikely(greh->flags & GRE_SEQ)) {
+               tpi->seq = *options;
+               options++;
+       } else
+               tpi->seq = 0;
 
-static void ipgre_tunnel_unlink(struct ipgre_net *ign, struct ip_tunnel *t)
-{
-       struct ip_tunnel __rcu **tp;
-       struct ip_tunnel *iter;
-
-       for (tp = ipgre_bucket(ign, t);
-            (iter = rtnl_dereference(*tp)) != NULL;
-            tp = &iter->next) {
-               if (t == iter) {
-                       rcu_assign_pointer(*tp, t->next);
-                       break;
+       /* WCCP version 1 and 2 protocol decoding.
+        * - Change protocol to IP
+        * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header
+        */
+       if (greh->flags == 0 && tpi->proto == htons(ETH_P_WCCP)) {
+               tpi->proto = htons(ETH_P_IP);
+               if ((*(u8 *)options & 0xF0) != 0x40) {
+                       *hdr_len += 4;
+                       if (!pskb_may_pull(skb, *hdr_len))
+                               return -EINVAL;
                }
        }
-}
-
-static struct ip_tunnel *ipgre_tunnel_find(struct net *net,
-                                          struct ip_tunnel_parm *parms,
-                                          int type)
-{
-       __be32 remote = parms->iph.daddr;
-       __be32 local = parms->iph.saddr;
-       __be32 key = parms->i_key;
-       int link = parms->link;
-       struct ip_tunnel *t;
-       struct ip_tunnel __rcu **tp;
-       struct ipgre_net *ign = net_generic(net, ipgre_net_id);
-
-       for (tp = __ipgre_bucket(ign, parms);
-            (t = rtnl_dereference(*tp)) != NULL;
-            tp = &t->next)
-               if (local == t->parms.iph.saddr &&
-                   remote == t->parms.iph.daddr &&
-                   key == t->parms.i_key &&
-                   link == t->parms.link &&
-                   type == t->dev->type)
-                       break;
-
-       return t;
-}
-
-static struct ip_tunnel *ipgre_tunnel_locate(struct net *net,
-               struct ip_tunnel_parm *parms, int create)
-{
-       struct ip_tunnel *t, *nt;
-       struct net_device *dev;
-       char name[IFNAMSIZ];
-       struct ipgre_net *ign = net_generic(net, ipgre_net_id);
-
-       t = ipgre_tunnel_find(net, parms, ARPHRD_IPGRE);
-       if (t || !create)
-               return t;
-
-       if (parms->name[0])
-               strlcpy(name, parms->name, IFNAMSIZ);
-       else
-               strcpy(name, "gre%d");
-
-       dev = alloc_netdev(sizeof(*t), name, ipgre_tunnel_setup);
-       if (!dev)
-               return NULL;
-
-       dev_net_set(dev, net);
-
-       nt = netdev_priv(dev);
-       nt->parms = *parms;
-       dev->rtnl_link_ops = &ipgre_link_ops;
-
-       dev->mtu = ipgre_tunnel_bind_dev(dev);
 
-       if (register_netdevice(dev) < 0)
-               goto failed_free;
-
-       /* Can use a lockless transmit, unless we generate output sequences */
-       if (!(nt->parms.o_flags & GRE_SEQ))
-               dev->features |= NETIF_F_LLTX;
-
-       dev_hold(dev);
-       ipgre_tunnel_link(ign, nt);
-       return nt;
-
-failed_free:
-       free_netdev(dev);
-       return NULL;
-}
-
-static void ipgre_tunnel_uninit(struct net_device *dev)
-{
-       struct net *net = dev_net(dev);
-       struct ipgre_net *ign = net_generic(net, ipgre_net_id);
-
-       ipgre_tunnel_unlink(ign, netdev_priv(dev));
-       dev_put(dev);
+       return 0;
 }
 
-
 static void ipgre_err(struct sk_buff *skb, u32 info)
 {
 
-/* All the routers (except for Linux) return only
-   8 bytes of packet payload. It means, that precise relaying of
-   ICMP in the real Internet is absolutely infeasible.
+       /* All the routers (except for Linux) return only
+          8 bytes of packet payload. It means, that precise relaying of
+          ICMP in the real Internet is absolutely infeasible.
 
-   Moreover, Cisco "wise men" put GRE key to the third word
-   in GRE header. It makes impossible maintaining even soft state for keyed
-   GRE tunnels with enabled checksum. Tell them "thank you".
-
-   Well, I wonder, rfc1812 was written by Cisco employee,
-   what the hell these idiots break standards established
-   by themselves???
- */
+          Moreover, Cisco "wise men" put GRE key to the third word
+          in GRE header. It makes impossible maintaining even soft
+          state for keyed GRE tunnels with enabled checksum. Tell
+          them "thank you".
 
+          Well, I wonder, rfc1812 was written by Cisco employee,
+          what the hell these idiots break standards established
+          by themselves???
+          */
+       struct net *net = dev_net(skb->dev);
+       struct ip_tunnel_net *itn;
        const struct iphdr *iph = (const struct iphdr *)skb->data;
-       __be16       *p = (__be16 *)(skb->data+(iph->ihl<<2));
-       int grehlen = (iph->ihl<<2) + 4;
        const int type = icmp_hdr(skb)->type;
        const int code = icmp_hdr(skb)->code;
        struct ip_tunnel *t;
-       __be16 flags;
-       __be32 key = 0;
+       struct tnl_ptk_info tpi;
+       int hdr_len;
+       bool csum_err = false;
 
-       flags = p[0];
-       if (flags&(GRE_CSUM|GRE_KEY|GRE_SEQ|GRE_ROUTING|GRE_VERSION)) {
-               if (flags&(GRE_VERSION|GRE_ROUTING))
+       if (parse_gre_header(skb, &tpi, &csum_err, &hdr_len)) {
+               if (!csum_err)          /* ignore csum errors. */
                        return;
-               if (flags&GRE_KEY) {
-                       grehlen += 4;
-                       if (flags&GRE_CSUM)
-                               grehlen += 4;
-               }
        }
 
-       /* If only 8 bytes returned, keyed message will be dropped here */
-       if (skb_headlen(skb) < grehlen)
-               return;
-
-       if (flags & GRE_KEY)
-               key = *(((__be32 *)p) + (grehlen / 4) - 1);
-
        switch (type) {
        default:
        case ICMP_PARAMETERPROB:
@@ -548,8 +276,13 @@ static void ipgre_err(struct sk_buff *skb, u32 info)
                break;
        }
 
-       t = ipgre_tunnel_lookup(skb->dev, iph->daddr, iph->saddr,
-                               flags, key, p[1]);
+       if (tpi.proto == htons(ETH_P_TEB))
+               itn = net_generic(net, gre_tap_net_id);
+       else
+               itn = net_generic(net, ipgre_net_id);
+
+       t = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi.flags,
+                            iph->daddr, iph->saddr, tpi.key);
 
        if (t == NULL)
                return;
@@ -578,158 +311,33 @@ static void ipgre_err(struct sk_buff *skb, u32 info)
        t->err_time = jiffies;
 }
 
-static inline u8
-ipgre_ecn_encapsulate(u8 tos, const struct iphdr *old_iph, struct sk_buff *skb)
-{
-       u8 inner = 0;
-       if (skb->protocol == htons(ETH_P_IP))
-               inner = old_iph->tos;
-       else if (skb->protocol == htons(ETH_P_IPV6))
-               inner = ipv6_get_dsfield((const struct ipv6hdr *)old_iph);
-       return INET_ECN_encapsulate(tos, inner);
-}
-
 static int ipgre_rcv(struct sk_buff *skb)
 {
+       struct net *net = dev_net(skb->dev);
+       struct ip_tunnel_net *itn;
        const struct iphdr *iph;
-       u8     *h;
-       __be16    flags;
-       __sum16   csum = 0;
-       __be32 key = 0;
-       u32    seqno = 0;
        struct ip_tunnel *tunnel;
-       int    offset = 4;
-       __be16 gre_proto;
-       int    err;
+       struct tnl_ptk_info tpi;
+       int hdr_len;
+       bool csum_err = false;
 
-       if (!pskb_may_pull(skb, 16))
+       if (parse_gre_header(skb, &tpi, &csum_err, &hdr_len) < 0)
                goto drop;
 
-       iph = ip_hdr(skb);
-       h = skb->data;
-       flags = *(__be16 *)h;
-
-       if (flags&(GRE_CSUM|GRE_KEY|GRE_ROUTING|GRE_SEQ|GRE_VERSION)) {
-               /* - Version must be 0.
-                  - We do not support routing headers.
-                */
-               if (flags&(GRE_VERSION|GRE_ROUTING))
-                       goto drop;
-
-               if (flags&GRE_CSUM) {
-                       switch (skb->ip_summed) {
-                       case CHECKSUM_COMPLETE:
-                               csum = csum_fold(skb->csum);
-                               if (!csum)
-                                       break;
-                               /* fall through */
-                       case CHECKSUM_NONE:
-                               skb->csum = 0;
-                               csum = __skb_checksum_complete(skb);
-                               skb->ip_summed = CHECKSUM_COMPLETE;
-                       }
-                       offset += 4;
-               }
-               if (flags&GRE_KEY) {
-                       key = *(__be32 *)(h + offset);
-                       offset += 4;
-               }
-               if (flags&GRE_SEQ) {
-                       seqno = ntohl(*(__be32 *)(h + offset));
-                       offset += 4;
-               }
-       }
+       if (tpi.proto == htons(ETH_P_TEB))
+               itn = net_generic(net, gre_tap_net_id);
+       else
+               itn = net_generic(net, ipgre_net_id);
 
-       gre_proto = *(__be16 *)(h + 2);
+       iph = ip_hdr(skb);
+       tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi.flags,
+                                 iph->saddr, iph->daddr, tpi.key);
 
-       tunnel = ipgre_tunnel_lookup(skb->dev,
-                                    iph->saddr, iph->daddr, flags, key,
-                                    gre_proto);
        if (tunnel) {
-               struct pcpu_tstats *tstats;
-
-               secpath_reset(skb);
-
-               skb->protocol = gre_proto;
-               /* WCCP version 1 and 2 protocol decoding.
-                * - Change protocol to IP
-                * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header
-                */
-               if (flags == 0 && gre_proto == htons(ETH_P_WCCP)) {
-                       skb->protocol = htons(ETH_P_IP);
-                       if ((*(h + offset) & 0xF0) != 0x40)
-                               offset += 4;
-               }
-
-               skb->mac_header = skb->network_header;
-               __pskb_pull(skb, offset);
-               skb_postpull_rcsum(skb, skb_transport_header(skb), offset);
-               skb->pkt_type = PACKET_HOST;
-#ifdef CONFIG_NET_IPGRE_BROADCAST
-               if (ipv4_is_multicast(iph->daddr)) {
-                       /* Looped back packet, drop it! */
-                       if (rt_is_output_route(skb_rtable(skb)))
-                               goto drop;
-                       tunnel->dev->stats.multicast++;
-                       skb->pkt_type = PACKET_BROADCAST;
-               }
-#endif
-
-               if (((flags&GRE_CSUM) && csum) ||
-                   (!(flags&GRE_CSUM) && tunnel->parms.i_flags&GRE_CSUM)) {
-                       tunnel->dev->stats.rx_crc_errors++;
-                       tunnel->dev->stats.rx_errors++;
-                       goto drop;
-               }
-               if (tunnel->parms.i_flags&GRE_SEQ) {
-                       if (!(flags&GRE_SEQ) ||
-                           (tunnel->i_seqno && (s32)(seqno - tunnel->i_seqno) < 0)) {
-                               tunnel->dev->stats.rx_fifo_errors++;
-                               tunnel->dev->stats.rx_errors++;
-                               goto drop;
-                       }
-                       tunnel->i_seqno = seqno + 1;
-               }
-
-               /* Warning: All skb pointers will be invalidated! */
-               if (tunnel->dev->type == ARPHRD_ETHER) {
-                       if (!pskb_may_pull(skb, ETH_HLEN)) {
-                               tunnel->dev->stats.rx_length_errors++;
-                               tunnel->dev->stats.rx_errors++;
-                               goto drop;
-                       }
-
-                       iph = ip_hdr(skb);
-                       skb->protocol = eth_type_trans(skb, tunnel->dev);
-                       skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
-               }
-
-               __skb_tunnel_rx(skb, tunnel->dev);
-
-               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);
-
-               gro_cells_receive(&tunnel->gro_cells, skb);
+               ip_tunnel_rcv(tunnel, skb, &tpi, log_ecn_error);
                return 0;
        }
        icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
-
 drop:
        kfree_skb(skb);
        return 0;
@@ -746,7 +354,7 @@ static struct sk_buff *handle_offloads(struct ip_tunnel *tunnel, struct sk_buff
                skb_shinfo(skb)->gso_type |= SKB_GSO_GRE;
                return skb;
        } else if (skb->ip_summed == CHECKSUM_PARTIAL &&
-                  tunnel->parms.o_flags&GRE_CSUM) {
+                  tunnel->parms.o_flags&TUNNEL_CSUM) {
                err = skb_checksum_help(skb);
                if (unlikely(err))
                        goto error;
@@ -760,494 +368,157 @@ error:
        return ERR_PTR(err);
 }
 
-static netdev_tx_t ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
+static struct sk_buff *gre_build_header(struct sk_buff *skb,
+                                       const struct tnl_ptk_info *tpi,
+                                       int hdr_len)
 {
-       struct pcpu_tstats *tstats = this_cpu_ptr(dev->tstats);
-       struct ip_tunnel *tunnel = netdev_priv(dev);
-       const struct iphdr  *old_iph;
-       const struct iphdr  *tiph;
-       struct flowi4 fl4;
-       u8     tos;
-       __be16 df;
-       struct rtable *rt;                      /* Route to the other host */
-       struct net_device *tdev;                /* Device to other host */
-       struct iphdr  *iph;                     /* Our new IP header */
-       unsigned int max_headroom;              /* The extra header space needed */
-       int    gre_hlen;
-       __be32 dst;
-       int    mtu;
-       u8     ttl;
-       int    err;
-       int    pkt_len;
-
-       skb = handle_offloads(tunnel, skb);
-       if (IS_ERR(skb)) {
-               dev->stats.tx_dropped++;
-               return NETDEV_TX_OK;
-       }
+       struct gre_base_hdr *greh;
 
-       if (!skb->encapsulation) {
-               skb_reset_inner_headers(skb);
-               skb->encapsulation = 1;
-       }
+       skb_push(skb, hdr_len);
 
-       old_iph = ip_hdr(skb);
+       greh = (struct gre_base_hdr *)skb->data;
+       greh->flags = tnl_flags_to_gre_flags(tpi->flags);
+       greh->protocol = tpi->proto;
 
-       if (dev->type == ARPHRD_ETHER)
-               IPCB(skb)->flags = 0;
+       if (tpi->flags&(TUNNEL_KEY|TUNNEL_CSUM|TUNNEL_SEQ)) {
+               __be32 *ptr = (__be32 *)(((u8 *)greh) + hdr_len - 4);
 
-       if (dev->header_ops && dev->type == ARPHRD_IPGRE) {
-               gre_hlen = 0;
-               tiph = (const struct iphdr *)skb->data;
-       } else {
-               gre_hlen = tunnel->hlen;
-               tiph = &tunnel->parms.iph;
-       }
-
-       if ((dst = tiph->daddr) == 0) {
-               /* NBMA tunnel */
-
-               if (skb_dst(skb) == NULL) {
-                       dev->stats.tx_fifo_errors++;
-                       goto tx_error;
+               if (tpi->flags&TUNNEL_SEQ) {
+                       *ptr = tpi->seq;
+                       ptr--;
                }
-
-               if (skb->protocol == htons(ETH_P_IP)) {
-                       rt = skb_rtable(skb);
-                       dst = rt_nexthop(rt, old_iph->daddr);
+               if (tpi->flags&TUNNEL_KEY) {
+                       *ptr = tpi->key;
+                       ptr--;
                }
-#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 == NULL)
-                               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;
+               if (tpi->flags&TUNNEL_CSUM &&
+                   !(skb_shinfo(skb)->gso_type & SKB_GSO_GRE)) {
+                       *(__sum16 *)ptr = 0;
+                       *(__sum16 *)ptr = csum_fold(skb_checksum(skb, 0,
+                                                                skb->len, 0));
                }
-#endif
-               else
-                       goto tx_error;
        }
 
-       ttl = tiph->ttl;
-       tos = tiph->tos;
-       if (tos & 0x1) {
-               tos &= ~0x1;
-               if (skb->protocol == htons(ETH_P_IP))
-                       tos = old_iph->tos;
-               else if (skb->protocol == htons(ETH_P_IPV6))
-                       tos = ipv6_get_dsfield((const struct ipv6hdr *)old_iph);
-       }
+       return skb;
+}
 
-       rt = ip_route_output_gre(dev_net(dev), &fl4, dst, tiph->saddr,
-                                tunnel->parms.o_key, RT_TOS(tos),
-                                tunnel->parms.link);
-       if (IS_ERR(rt)) {
-               dev->stats.tx_carrier_errors++;
-               goto tx_error;
-       }
-       tdev = rt->dst.dev;
+static void __gre_xmit(struct sk_buff *skb, struct net_device *dev,
+                      const struct iphdr *tnl_params,
+                      __be16 proto)
+{
+       struct ip_tunnel *tunnel = netdev_priv(dev);
+       struct tnl_ptk_info tpi;
 
-       if (tdev == dev) {
-               ip_rt_put(rt);
-               dev->stats.collisions++;
-               goto tx_error;
+       if (likely(!skb->encapsulation)) {
+               skb_reset_inner_headers(skb);
+               skb->encapsulation = 1;
        }
 
-       df = tiph->frag_off;
-       if (df)
-               mtu = dst_mtu(&rt->dst) - dev->hard_header_len - 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)) {
-               df |= (old_iph->frag_off&htons(IP_DF));
+       tpi.flags = tunnel->parms.o_flags;
+       tpi.proto = proto;
+       tpi.key = tunnel->parms.o_key;
+       if (tunnel->parms.o_flags & TUNNEL_SEQ)
+               tunnel->o_seqno++;
+       tpi.seq = htonl(tunnel->o_seqno);
 
-               if (!skb_is_gso(skb) &&
-                   (old_iph->frag_off&htons(IP_DF)) &&
-                   mtu < ntohs(old_iph->tot_len)) {
-                       icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
-                       ip_rt_put(rt);
-                       goto tx_error;
-               }
+       /* Push GRE header. */
+       skb = gre_build_header(skb, &tpi, tunnel->hlen);
+       if (unlikely(!skb)) {
+               dev->stats.tx_dropped++;
+               return;
        }
-#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 < skb->len - tunnel->hlen + gre_hlen) {
-                       icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
-                       ip_rt_put(rt);
-                       goto tx_error;
-               }
-       }
-#endif
+       ip_tunnel_xmit(skb, dev, tnl_params);
+}
 
-       if (tunnel->err_count > 0) {
-               if (time_before(jiffies,
-                               tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
-                       tunnel->err_count--;
+static netdev_tx_t ipgre_xmit(struct sk_buff *skb,
+                             struct net_device *dev)
+{
+       struct ip_tunnel *tunnel = netdev_priv(dev);
+       const struct iphdr *tnl_params;
 
-                       dst_link_failure(skb);
-               } else
-                       tunnel->err_count = 0;
-       }
+       skb = handle_offloads(tunnel, skb);
+       if (IS_ERR(skb))
+               goto out;
 
-       max_headroom = LL_RESERVED_SPACE(tdev) + gre_hlen + rt->dst.header_len;
-
-       if (skb_headroom(skb) < max_headroom || skb_shared(skb)||
-           (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
-               struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
-               if (max_headroom > dev->needed_headroom)
-                       dev->needed_headroom = max_headroom;
-               if (!new_skb) {
-                       ip_rt_put(rt);
-                       dev->stats.tx_dropped++;
-                       dev_kfree_skb(skb);
-                       return NETDEV_TX_OK;
-               }
-               if (skb->sk)
-                       skb_set_owner_w(new_skb, skb->sk);
-               dev_kfree_skb(skb);
-               skb = new_skb;
-               old_iph = ip_hdr(skb);
-               /* Warning : tiph value might point to freed memory */
-       }
+       if (dev->header_ops) {
+               /* Need space for new headers */
+               if (skb_cow_head(skb, dev->needed_headroom -
+                                     (tunnel->hlen + sizeof(struct iphdr))))
+                       goto free_skb;
 
-       skb_push(skb, gre_hlen);
-       skb_reset_network_header(skb);
-       skb_set_transport_header(skb, sizeof(*iph));
-       memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
-       IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED |
-                             IPSKB_REROUTED);
-       skb_dst_drop(skb);
-       skb_dst_set(skb, &rt->dst);
-
-       /*
-        *      Push down and install the IPIP header.
-        */
+               tnl_params = (const struct iphdr *)skb->data;
 
-       iph                     =       ip_hdr(skb);
-       iph->version            =       4;
-       iph->ihl                =       sizeof(struct iphdr) >> 2;
-       iph->frag_off           =       df;
-       iph->protocol           =       IPPROTO_GRE;
-       iph->tos                =       ipgre_ecn_encapsulate(tos, old_iph, skb);
-       iph->daddr              =       fl4.daddr;
-       iph->saddr              =       fl4.saddr;
-       iph->ttl                =       ttl;
-
-       tunnel_ip_select_ident(skb, old_iph, &rt->dst);
-
-       if (ttl == 0) {
-               if (skb->protocol == htons(ETH_P_IP))
-                       iph->ttl = old_iph->ttl;
-#if IS_ENABLED(CONFIG_IPV6)
-               else if (skb->protocol == htons(ETH_P_IPV6))
-                       iph->ttl = ((const struct ipv6hdr *)old_iph)->hop_limit;
-#endif
-               else
-                       iph->ttl = ip4_dst_hoplimit(&rt->dst);
-       }
-
-       ((__be16 *)(iph + 1))[0] = tunnel->parms.o_flags;
-       ((__be16 *)(iph + 1))[1] = (dev->type == ARPHRD_ETHER) ?
-                                  htons(ETH_P_TEB) : skb->protocol;
-
-       if (tunnel->parms.o_flags&(GRE_KEY|GRE_CSUM|GRE_SEQ)) {
-               __be32 *ptr = (__be32 *)(((u8 *)iph) + tunnel->hlen - 4);
+               /* Pull skb since ip_tunnel_xmit() needs skb->data pointing
+                * to gre header.
+                */
+               skb_pull(skb, tunnel->hlen + sizeof(struct iphdr));
+       } else {
+               if (skb_cow_head(skb, dev->needed_headroom))
+                       goto free_skb;
 
-               if (tunnel->parms.o_flags&GRE_SEQ) {
-                       ++tunnel->o_seqno;
-                       *ptr = htonl(tunnel->o_seqno);
-                       ptr--;
-               }
-               if (tunnel->parms.o_flags&GRE_KEY) {
-                       *ptr = tunnel->parms.o_key;
-                       ptr--;
-               }
-               /* Skip GRE checksum if skb is getting offloaded. */
-               if (!(skb_shinfo(skb)->gso_type & SKB_GSO_GRE) &&
-                   (tunnel->parms.o_flags&GRE_CSUM)) {
-                       int offset = skb_transport_offset(skb);
-
-                       if (skb_has_shared_frag(skb)) {
-                               err = __skb_linearize(skb);
-                               if (err)
-                                       goto tx_error;
-                       }
-
-                       *ptr = 0;
-                       *(__sum16 *)ptr = csum_fold(skb_checksum(skb, offset,
-                                                                skb->len - offset,
-                                                                0));
-               }
+               tnl_params = &tunnel->parms.iph;
        }
 
-       nf_reset(skb);
+       __gre_xmit(skb, dev, tnl_params, skb->protocol);
 
-       pkt_len = skb->len - skb_transport_offset(skb);
-       err = ip_local_out(skb);
-       if (likely(net_xmit_eval(err) == 0)) {
-               u64_stats_update_begin(&tstats->syncp);
-               tstats->tx_bytes += pkt_len;
-               tstats->tx_packets++;
-               u64_stats_update_end(&tstats->syncp);
-       } else {
-               dev->stats.tx_errors++;
-               dev->stats.tx_aborted_errors++;
-       }
        return NETDEV_TX_OK;
 
-#if IS_ENABLED(CONFIG_IPV6)
-tx_error_icmp:
-       dst_link_failure(skb);
-#endif
-tx_error:
-       dev->stats.tx_errors++;
+free_skb:
        dev_kfree_skb(skb);
+out:
+       dev->stats.tx_dropped++;
        return NETDEV_TX_OK;
 }
 
-static int ipgre_tunnel_bind_dev(struct net_device *dev)
+static netdev_tx_t gre_tap_xmit(struct sk_buff *skb,
+                               struct net_device *dev)
 {
-       struct net_device *tdev = NULL;
-       struct ip_tunnel *tunnel;
-       const struct iphdr *iph;
-       int hlen = LL_MAX_HEADER;
-       int mtu = ETH_DATA_LEN;
-       int addend = sizeof(struct iphdr) + 4;
-
-       tunnel = netdev_priv(dev);
-       iph = &tunnel->parms.iph;
-
-       /* Guess output device to choose reasonable mtu and needed_headroom */
-
-       if (iph->daddr) {
-               struct flowi4 fl4;
-               struct rtable *rt;
-
-               rt = ip_route_output_gre(dev_net(dev), &fl4,
-                                        iph->daddr, iph->saddr,
-                                        tunnel->parms.o_key,
-                                        RT_TOS(iph->tos),
-                                        tunnel->parms.link);
-               if (!IS_ERR(rt)) {
-                       tdev = rt->dst.dev;
-                       ip_rt_put(rt);
-               }
-
-               if (dev->type != ARPHRD_ETHER)
-                       dev->flags |= IFF_POINTOPOINT;
-       }
+       struct ip_tunnel *tunnel = netdev_priv(dev);
 
-       if (!tdev && tunnel->parms.link)
-               tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link);
+       skb = handle_offloads(tunnel, skb);
+       if (IS_ERR(skb))
+               goto out;
 
-       if (tdev) {
-               hlen = tdev->hard_header_len + tdev->needed_headroom;
-               mtu = tdev->mtu;
-       }
-       dev->iflink = tunnel->parms.link;
-
-       /* Precalculate GRE options length */
-       if (tunnel->parms.o_flags&(GRE_CSUM|GRE_KEY|GRE_SEQ)) {
-               if (tunnel->parms.o_flags&GRE_CSUM)
-                       addend += 4;
-               if (tunnel->parms.o_flags&GRE_KEY)
-                       addend += 4;
-               if (tunnel->parms.o_flags&GRE_SEQ)
-                       addend += 4;
-       }
-       dev->needed_headroom = addend + hlen;
-       mtu -= dev->hard_header_len + addend;
+       if (skb_cow_head(skb, dev->needed_headroom))
+               goto free_skb;
 
-       if (mtu < 68)
-               mtu = 68;
+       __gre_xmit(skb, dev, &tunnel->parms.iph, htons(ETH_P_TEB));
 
-       tunnel->hlen = addend;
-       /* TCP offload with GRE SEQ is not supported. */
-       if (!(tunnel->parms.o_flags & GRE_SEQ)) {
-               dev->features           |= NETIF_F_GSO_SOFTWARE;
-               dev->hw_features        |= NETIF_F_GSO_SOFTWARE;
-       }
+       return NETDEV_TX_OK;
 
-       return mtu;
+free_skb:
+       dev_kfree_skb(skb);
+out:
+       dev->stats.tx_dropped++;
+       return NETDEV_TX_OK;
 }
 
-static int
-ipgre_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
+static int ipgre_tunnel_ioctl(struct net_device *dev,
+                             struct ifreq *ifr, int cmd)
 {
        int err = 0;
        struct ip_tunnel_parm p;
-       struct ip_tunnel *t;
-       struct net *net = dev_net(dev);
-       struct ipgre_net *ign = net_generic(net, ipgre_net_id);
-
-       switch (cmd) {
-       case SIOCGETTUNNEL:
-               t = NULL;
-               if (dev == ign->fb_tunnel_dev) {
-                       if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
-                               err = -EFAULT;
-                               break;
-                       }
-                       t = ipgre_tunnel_locate(net, &p, 0);
-               }
-               if (t == NULL)
-                       t = netdev_priv(dev);
-               memcpy(&p, &t->parms, sizeof(p));
-               if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
-                       err = -EFAULT;
-               break;
-
-       case SIOCADDTUNNEL:
-       case SIOCCHGTUNNEL:
-               err = -EPERM;
-               if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
-                       goto done;
-
-               err = -EFAULT;
-               if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
-                       goto done;
-
-               err = -EINVAL;
-               if (p.iph.version != 4 || p.iph.protocol != IPPROTO_GRE ||
-                   p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)) ||
-                   ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING)))
-                       goto done;
-               if (p.iph.ttl)
-                       p.iph.frag_off |= htons(IP_DF);
-
-               if (!(p.i_flags&GRE_KEY))
-                       p.i_key = 0;
-               if (!(p.o_flags&GRE_KEY))
-                       p.o_key = 0;
-
-               t = ipgre_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
-
-               if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
-                       if (t != NULL) {
-                               if (t->dev != dev) {
-                                       err = -EEXIST;
-                                       break;
-                               }
-                       } else {
-                               unsigned int nflags = 0;
-
-                               t = netdev_priv(dev);
-
-                               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;
-                               }
-                               ipgre_tunnel_unlink(ign, t);
-                               synchronize_net();
-                               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;
-                               memcpy(dev->dev_addr, &p.iph.saddr, 4);
-                               memcpy(dev->broadcast, &p.iph.daddr, 4);
-                               ipgre_tunnel_link(ign, t);
-                               netdev_state_change(dev);
-                       }
-               }
-
-               if (t) {
-                       err = 0;
-                       if (cmd == SIOCCHGTUNNEL) {
-                               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) {
-                                       t->parms.link = p.link;
-                                       dev->mtu = ipgre_tunnel_bind_dev(dev);
-                                       netdev_state_change(dev);
-                               }
-                       }
-                       if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
-                               err = -EFAULT;
-               } else
-                       err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
-               break;
-
-       case SIOCDELTUNNEL:
-               err = -EPERM;
-               if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
-                       goto done;
-
-               if (dev == ign->fb_tunnel_dev) {
-                       err = -EFAULT;
-                       if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
-                               goto done;
-                       err = -ENOENT;
-                       if ((t = ipgre_tunnel_locate(net, &p, 0)) == NULL)
-                               goto done;
-                       err = -EPERM;
-                       if (t == netdev_priv(ign->fb_tunnel_dev))
-                               goto done;
-                       dev = t->dev;
-               }
-               unregister_netdevice(dev);
-               err = 0;
-               break;
 
-       default:
-               err = -EINVAL;
+       if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
+               return -EFAULT;
+       if (p.iph.version != 4 || p.iph.protocol != IPPROTO_GRE ||
+           p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)) ||
+           ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING))) {
+               return -EINVAL;
        }
+       p.i_flags = gre_flags_to_tnl_flags(p.i_flags);
+       p.o_flags = gre_flags_to_tnl_flags(p.o_flags);
 
-done:
-       return err;
-}
+       err = ip_tunnel_ioctl(dev, &p, cmd);
+       if (err)
+               return err;
 
-static int ipgre_tunnel_change_mtu(struct net_device *dev, int new_mtu)
-{
-       struct ip_tunnel *tunnel = netdev_priv(dev);
-       if (new_mtu < 68 ||
-           new_mtu > 0xFFF8 - dev->hard_header_len - tunnel->hlen)
-               return -EINVAL;
-       dev->mtu = new_mtu;
+       p.i_flags = tnl_flags_to_gre_flags(p.i_flags);
+       p.o_flags = tnl_flags_to_gre_flags(p.o_flags);
+
+       if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
+               return -EFAULT;
        return 0;
 }
 
@@ -1277,25 +548,23 @@ static int ipgre_tunnel_change_mtu(struct net_device *dev, int new_mtu)
    ...
    ftp fec0:6666:6666::193.233.7.65
    ...
-
  */
-
 static int ipgre_header(struct sk_buff *skb, struct net_device *dev,
                        unsigned short type,
                        const void *daddr, const void *saddr, unsigned int len)
 {
        struct ip_tunnel *t = netdev_priv(dev);
-       struct iphdr *iph = (struct iphdr *)skb_push(skb, t->hlen);
-       __be16 *p = (__be16 *)(iph+1);
+       struct iphdr *iph;
+       struct gre_base_hdr *greh;
 
-       memcpy(iph, &t->parms.iph, sizeof(struct iphdr));
-       p[0]            = t->parms.o_flags;
-       p[1]            = htons(type);
+       iph = (struct iphdr *)skb_push(skb, t->hlen + sizeof(*iph));
+       greh = (struct gre_base_hdr *)(iph+1);
+       greh->flags = tnl_flags_to_gre_flags(t->parms.o_flags);
+       greh->protocol = htons(type);
 
-       /*
-        *      Set the source hardware address.
-        */
+       memcpy(iph, &t->parms.iph, sizeof(struct iphdr));
 
+       /* Set the source hardware address. */
        if (saddr)
                memcpy(&iph->saddr, saddr, 4);
        if (daddr)
@@ -1303,7 +572,7 @@ static int ipgre_header(struct sk_buff *skb, struct net_device *dev,
        if (iph->daddr)
                return t->hlen;
 
-       return -t->hlen;
+       return -(t->hlen + sizeof(*iph));
 }
 
 static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr)
@@ -1357,31 +626,21 @@ static int ipgre_close(struct net_device *dev)
        }
        return 0;
 }
-
 #endif
 
 static const struct net_device_ops ipgre_netdev_ops = {
        .ndo_init               = ipgre_tunnel_init,
-       .ndo_uninit             = ipgre_tunnel_uninit,
+       .ndo_uninit             = ip_tunnel_uninit,
 #ifdef CONFIG_NET_IPGRE_BROADCAST
        .ndo_open               = ipgre_open,
        .ndo_stop               = ipgre_close,
 #endif
-       .ndo_start_xmit         = ipgre_tunnel_xmit,
+       .ndo_start_xmit         = ipgre_xmit,
        .ndo_do_ioctl           = ipgre_tunnel_ioctl,
-       .ndo_change_mtu         = ipgre_tunnel_change_mtu,
-       .ndo_get_stats64        = ipgre_get_stats64,
+       .ndo_change_mtu         = ip_tunnel_change_mtu,
+       .ndo_get_stats64        = ip_tunnel_get_stats64,
 };
 
-static void ipgre_dev_free(struct net_device *dev)
-{
-       struct ip_tunnel *tunnel = netdev_priv(dev);
-
-       gro_cells_destroy(&tunnel->gro_cells);
-       free_percpu(dev->tstats);
-       free_netdev(dev);
-}
-
 #define GRE_FEATURES (NETIF_F_SG |             \
                      NETIF_F_FRAGLIST |        \
                      NETIF_F_HIGHDMA |         \
@@ -1390,35 +649,48 @@ static void ipgre_dev_free(struct net_device *dev)
 static void ipgre_tunnel_setup(struct net_device *dev)
 {
        dev->netdev_ops         = &ipgre_netdev_ops;
-       dev->destructor         = ipgre_dev_free;
+       ip_tunnel_setup(dev, ipgre_net_id);
+}
 
-       dev->type               = ARPHRD_IPGRE;
-       dev->needed_headroom    = LL_MAX_HEADER + sizeof(struct iphdr) + 4;
+static void __gre_tunnel_init(struct net_device *dev)
+{
+       struct ip_tunnel *tunnel;
+
+       tunnel = netdev_priv(dev);
+       tunnel->hlen = ip_gre_calc_hlen(tunnel->parms.o_flags);
+       tunnel->parms.iph.protocol = IPPROTO_GRE;
+
+       dev->needed_headroom    = LL_MAX_HEADER + sizeof(struct iphdr) + 4;
        dev->mtu                = ETH_DATA_LEN - sizeof(struct iphdr) - 4;
-       dev->flags              = IFF_NOARP;
-       dev->iflink             = 0;
-       dev->addr_len           = 4;
-       dev->features           |= NETIF_F_NETNS_LOCAL;
-       dev->priv_flags         &= ~IFF_XMIT_DST_RELEASE;
 
-       dev->features           |= GRE_FEATURES;
+       dev->features           |= NETIF_F_NETNS_LOCAL | GRE_FEATURES;
        dev->hw_features        |= GRE_FEATURES;
+
+       if (!(tunnel->parms.o_flags & TUNNEL_SEQ)) {
+               /* TCP offload with GRE SEQ is not supported. */
+               dev->features    |= NETIF_F_GSO_SOFTWARE;
+               dev->hw_features |= NETIF_F_GSO_SOFTWARE;
+               /* Can use a lockless transmit, unless we generate
+                * output sequences
+                */
+               dev->features |= NETIF_F_LLTX;
+       }
 }
 
 static int ipgre_tunnel_init(struct net_device *dev)
 {
-       struct ip_tunnel *tunnel;
-       struct iphdr *iph;
-       int err;
+       struct ip_tunnel *tunnel = netdev_priv(dev);
+       struct iphdr *iph = &tunnel->parms.iph;
 
-       tunnel = netdev_priv(dev);
-       iph = &tunnel->parms.iph;
+       __gre_tunnel_init(dev);
 
-       tunnel->dev = dev;
-       strcpy(tunnel->parms.name, dev->name);
+       memcpy(dev->dev_addr, &iph->saddr, 4);
+       memcpy(dev->broadcast, &iph->daddr, 4);
 
-       memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
-       memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
+       dev->type               = ARPHRD_IPGRE;
+       dev->flags              = IFF_NOARP;
+       dev->priv_flags         &= ~IFF_XMIT_DST_RELEASE;
+       dev->addr_len           = 4;
 
        if (iph->daddr) {
 #ifdef CONFIG_NET_IPGRE_BROADCAST
@@ -1432,106 +704,30 @@ static int ipgre_tunnel_init(struct net_device *dev)
        } else
                dev->header_ops = &ipgre_header_ops;
 
-       dev->tstats = alloc_percpu(struct pcpu_tstats);
-       if (!dev->tstats)
-               return -ENOMEM;
-
-       err = gro_cells_init(&tunnel->gro_cells, dev);
-       if (err) {
-               free_percpu(dev->tstats);
-               return err;
-       }
-
-       return 0;
-}
-
-static void ipgre_fb_tunnel_init(struct net_device *dev)
-{
-       struct ip_tunnel *tunnel = netdev_priv(dev);
-       struct iphdr *iph = &tunnel->parms.iph;
-
-       tunnel->dev = dev;
-       strcpy(tunnel->parms.name, dev->name);
-
-       iph->version            = 4;
-       iph->protocol           = IPPROTO_GRE;
-       iph->ihl                = 5;
-       tunnel->hlen            = sizeof(struct iphdr) + 4;
-
-       dev_hold(dev);
+       return ip_tunnel_init(dev);
 }
 
-
 static const struct gre_protocol ipgre_protocol = {
        .handler     = ipgre_rcv,
        .err_handler = ipgre_err,
 };
 
-static void ipgre_destroy_tunnels(struct ipgre_net *ign, struct list_head *head)
-{
-       int prio;
-
-       for (prio = 0; prio < 4; prio++) {
-               int h;
-               for (h = 0; h < HASH_SIZE; h++) {
-                       struct ip_tunnel *t;
-
-                       t = rtnl_dereference(ign->tunnels[prio][h]);
-
-                       while (t != NULL) {
-                               unregister_netdevice_queue(t->dev, head);
-                               t = rtnl_dereference(t->next);
-                       }
-               }
-       }
-}
-
 static int __net_init ipgre_init_net(struct net *net)
 {
-       struct ipgre_net *ign = net_generic(net, ipgre_net_id);
-       int err;
-
-       ign->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "gre0",
-                                          ipgre_tunnel_setup);
-       if (!ign->fb_tunnel_dev) {
-               err = -ENOMEM;
-               goto err_alloc_dev;
-       }
-       dev_net_set(ign->fb_tunnel_dev, net);
-
-       ipgre_fb_tunnel_init(ign->fb_tunnel_dev);
-       ign->fb_tunnel_dev->rtnl_link_ops = &ipgre_link_ops;
-
-       if ((err = register_netdev(ign->fb_tunnel_dev)))
-               goto err_reg_dev;
-
-       rcu_assign_pointer(ign->tunnels_wc[0],
-                          netdev_priv(ign->fb_tunnel_dev));
-       return 0;
-
-err_reg_dev:
-       ipgre_dev_free(ign->fb_tunnel_dev);
-err_alloc_dev:
-       return err;
+       return ip_tunnel_init_net(net, ipgre_net_id, &ipgre_link_ops, NULL);
 }
 
 static void __net_exit ipgre_exit_net(struct net *net)
 {
-       struct ipgre_net *ign;
-       LIST_HEAD(list);
-
-       ign = net_generic(net, ipgre_net_id);
-       rtnl_lock();
-       ipgre_destroy_tunnels(ign, &list);
-       unregister_netdevice_many(&list);
-       rtnl_unlock();
+       struct ip_tunnel_net *itn = net_generic(net, ipgre_net_id);
+       ip_tunnel_delete_net(itn);
 }
 
 static struct pernet_operations ipgre_net_ops = {
        .init = ipgre_init_net,
        .exit = ipgre_exit_net,
        .id   = &ipgre_net_id,
-       .size = sizeof(struct ipgre_net),
+       .size = sizeof(struct ip_tunnel_net),
 };
 
 static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
@@ -1576,8 +772,8 @@ out:
        return ipgre_tunnel_validate(tb, data);
 }
 
-static void ipgre_netlink_parms(struct nlattr *data[],
-                               struct ip_tunnel_parm *parms)
+static void ipgre_netlink_parms(struct nlattr *data[], struct nlattr *tb[],
+                              struct ip_tunnel_parm *parms)
 {
        memset(parms, 0, sizeof(*parms));
 
@@ -1590,10 +786,10 @@ static void ipgre_netlink_parms(struct nlattr *data[],
                parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
 
        if (data[IFLA_GRE_IFLAGS])
-               parms->i_flags = nla_get_be16(data[IFLA_GRE_IFLAGS]);
+               parms->i_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_IFLAGS]));
 
        if (data[IFLA_GRE_OFLAGS])
-               parms->o_flags = nla_get_be16(data[IFLA_GRE_OFLAGS]);
+               parms->o_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_OFLAGS]));
 
        if (data[IFLA_GRE_IKEY])
                parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
@@ -1617,148 +813,46 @@ static void ipgre_netlink_parms(struct nlattr *data[],
                parms->iph.frag_off = htons(IP_DF);
 }
 
-static int ipgre_tap_init(struct net_device *dev)
+static int gre_tap_init(struct net_device *dev)
 {
-       struct ip_tunnel *tunnel;
-
-       tunnel = netdev_priv(dev);
-
-       tunnel->dev = dev;
-       strcpy(tunnel->parms.name, dev->name);
+       __gre_tunnel_init(dev);
 
-       ipgre_tunnel_bind_dev(dev);
-
-       dev->tstats = alloc_percpu(struct pcpu_tstats);
-       if (!dev->tstats)
-               return -ENOMEM;
-
-       return 0;
+       return ip_tunnel_init(dev);
 }
 
-static const struct net_device_ops ipgre_tap_netdev_ops = {
-       .ndo_init               = ipgre_tap_init,
-       .ndo_uninit             = ipgre_tunnel_uninit,
-       .ndo_start_xmit         = ipgre_tunnel_xmit,
+static const struct net_device_ops gre_tap_netdev_ops = {
+       .ndo_init               = gre_tap_init,
+       .ndo_uninit             = ip_tunnel_uninit,
+       .ndo_start_xmit         = gre_tap_xmit,
        .ndo_set_mac_address    = eth_mac_addr,
        .ndo_validate_addr      = eth_validate_addr,
-       .ndo_change_mtu         = ipgre_tunnel_change_mtu,
-       .ndo_get_stats64        = ipgre_get_stats64,
+       .ndo_change_mtu         = ip_tunnel_change_mtu,
+       .ndo_get_stats64        = ip_tunnel_get_stats64,
 };
 
 static void ipgre_tap_setup(struct net_device *dev)
 {
-
        ether_setup(dev);
-
-       dev->netdev_ops         = &ipgre_tap_netdev_ops;
-       dev->destructor         = ipgre_dev_free;
-
-       dev->iflink             = 0;
-       dev->features           |= NETIF_F_NETNS_LOCAL;
-
-       dev->features           |= GRE_FEATURES;
-       dev->hw_features        |= GRE_FEATURES;
+       dev->netdev_ops         = &gre_tap_netdev_ops;
+       ip_tunnel_setup(dev, gre_tap_net_id);
 }
 
-static int ipgre_newlink(struct net *src_net, struct net_device *dev, struct nlattr *tb[],
-                        struct nlattr *data[])
+static int ipgre_newlink(struct net *src_net, struct net_device *dev,
+                        struct nlattr *tb[], struct nlattr *data[])
 {
-       struct ip_tunnel *nt;
-       struct net *net = dev_net(dev);
-       struct ipgre_net *ign = net_generic(net, ipgre_net_id);
-       int mtu;
-       int err;
-
-       nt = netdev_priv(dev);
-       ipgre_netlink_parms(data, &nt->parms);
-
-       if (ipgre_tunnel_find(net, &nt->parms, dev->type))
-               return -EEXIST;
-
-       if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
-               eth_hw_addr_random(dev);
-
-       mtu = ipgre_tunnel_bind_dev(dev);
-       if (!tb[IFLA_MTU])
-               dev->mtu = mtu;
-
-       /* Can use a lockless transmit, unless we generate output sequences */
-       if (!(nt->parms.o_flags & GRE_SEQ))
-               dev->features |= NETIF_F_LLTX;
-
-       err = register_netdevice(dev);
-       if (err)
-               goto out;
-
-       dev_hold(dev);
-       ipgre_tunnel_link(ign, nt);
+       struct ip_tunnel_parm p;
 
-out:
-       return err;
+       ipgre_netlink_parms(data, tb, &p);
+       return ip_tunnel_newlink(dev, tb, &p);
 }
 
 static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[],
                            struct nlattr *data[])
 {
-       struct ip_tunnel *t, *nt;
-       struct net *net = dev_net(dev);
-       struct ipgre_net *ign = net_generic(net, ipgre_net_id);
        struct ip_tunnel_parm p;
-       int mtu;
-
-       if (dev == ign->fb_tunnel_dev)
-               return -EINVAL;
-
-       nt = netdev_priv(dev);
-       ipgre_netlink_parms(data, &p);
-
-       t = ipgre_tunnel_locate(net, &p, 0);
-
-       if (t) {
-               if (t->dev != dev)
-                       return -EEXIST;
-       } else {
-               t = nt;
-
-               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;
-               }
 
-               ipgre_tunnel_unlink(ign, t);
-               t->parms.iph.saddr = p.iph.saddr;
-               t->parms.iph.daddr = p.iph.daddr;
-               t->parms.i_key = p.i_key;
-               if (dev->type != ARPHRD_ETHER) {
-                       memcpy(dev->dev_addr, &p.iph.saddr, 4);
-                       memcpy(dev->broadcast, &p.iph.daddr, 4);
-               }
-               ipgre_tunnel_link(ign, t);
-               netdev_state_change(dev);
-       }
-
-       t->parms.o_key = p.o_key;
-       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) {
-               t->parms.link = p.link;
-               mtu = ipgre_tunnel_bind_dev(dev);
-               if (!tb[IFLA_MTU])
-                       dev->mtu = mtu;
-               netdev_state_change(dev);
-       }
-
-       return 0;
+       ipgre_netlink_parms(data, tb, &p);
+       return ip_tunnel_changelink(dev, tb, &p);
 }
 
 static size_t ipgre_get_size(const struct net_device *dev)
@@ -1793,8 +887,8 @@ static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev)
        struct ip_tunnel_parm *p = &t->parms;
 
        if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
-           nla_put_be16(skb, IFLA_GRE_IFLAGS, p->i_flags) ||
-           nla_put_be16(skb, IFLA_GRE_OFLAGS, p->o_flags) ||
+           nla_put_be16(skb, IFLA_GRE_IFLAGS, tnl_flags_to_gre_flags(p->i_flags)) ||
+           nla_put_be16(skb, IFLA_GRE_OFLAGS, tnl_flags_to_gre_flags(p->o_flags)) ||
            nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
            nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
            nla_put_be32(skb, IFLA_GRE_LOCAL, p->iph.saddr) ||
@@ -1832,6 +926,7 @@ static struct rtnl_link_ops ipgre_link_ops __read_mostly = {
        .validate       = ipgre_tunnel_validate,
        .newlink        = ipgre_newlink,
        .changelink     = ipgre_changelink,
+       .dellink        = ip_tunnel_dellink,
        .get_size       = ipgre_get_size,
        .fill_info      = ipgre_fill_info,
 };
@@ -1845,13 +940,28 @@ static struct rtnl_link_ops ipgre_tap_ops __read_mostly = {
        .validate       = ipgre_tap_validate,
        .newlink        = ipgre_newlink,
        .changelink     = ipgre_changelink,
+       .dellink        = ip_tunnel_dellink,
        .get_size       = ipgre_get_size,
        .fill_info      = ipgre_fill_info,
 };
 
-/*
- *     And now the modules code and kernel interface.
- */
+static int __net_init ipgre_tap_init_net(struct net *net)
+{
+       return ip_tunnel_init_net(net, gre_tap_net_id, &ipgre_tap_ops, NULL);
+}
+
+static void __net_exit ipgre_tap_exit_net(struct net *net)
+{
+       struct ip_tunnel_net *itn = net_generic(net, gre_tap_net_id);
+       ip_tunnel_delete_net(itn);
+}
+
+static struct pernet_operations ipgre_tap_net_ops = {
+       .init = ipgre_tap_init_net,
+       .exit = ipgre_tap_exit_net,
+       .id   = &gre_tap_net_id,
+       .size = sizeof(struct ip_tunnel_net),
+};
 
 static int __init ipgre_init(void)
 {
@@ -1863,6 +973,10 @@ static int __init ipgre_init(void)
        if (err < 0)
                return err;
 
+       err = register_pernet_device(&ipgre_tap_net_ops);
+       if (err < 0)
+               goto pnet_tap_faied;
+
        err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO);
        if (err < 0) {
                pr_info("%s: can't add protocol\n", __func__);
@@ -1877,16 +991,17 @@ static int __init ipgre_init(void)
        if (err < 0)
                goto tap_ops_failed;
 
-out:
-       return err;
+       return 0;
 
 tap_ops_failed:
        rtnl_link_unregister(&ipgre_link_ops);
 rtnl_link_failed:
        gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
 add_proto_failed:
+       unregister_pernet_device(&ipgre_tap_net_ops);
+pnet_tap_faied:
        unregister_pernet_device(&ipgre_net_ops);
-       goto out;
+       return err;
 }
 
 static void __exit ipgre_fini(void)
@@ -1895,6 +1010,7 @@ static void __exit ipgre_fini(void)
        rtnl_link_unregister(&ipgre_link_ops);
        if (gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO) < 0)
                pr_info("%s: can't remove protocol\n", __func__);
+       unregister_pernet_device(&ipgre_tap_net_ops);
        unregister_pernet_device(&ipgre_net_ops);
 }
 
@@ -1904,3 +1020,4 @@ MODULE_LICENSE("GPL");
 MODULE_ALIAS_RTNL_LINK("gre");
 MODULE_ALIAS_RTNL_LINK("gretap");
 MODULE_ALIAS_NETDEV("gre0");
+MODULE_ALIAS_NETDEV("gretap0");