Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next

Pull networking updates from David Miller:
 "This is a re-do of the net-next pull request for the current merge
  window.  The only difference from the one I made the other day is that
  this has Eliezer's interface renames and the timeout handling changes
  made based upon your feedback, as well as a few bug fixes that have
  trickeled in.

  Highlights:

   1) Low latency device polling, eliminating the cost of interrupt
      handling and context switches.  Allows direct polling of a network
      device from socket operations, such as recvmsg() and poll().

      Currently ixgbe, mlx4, and bnx2x support this feature.

      Full high level description, performance numbers, and design in
      commit 0a4db187a999 ("Merge branch 'll_poll'")

      From Eliezer Tamir.

   2) With the routing cache removed, ip_check_mc_rcu() gets exercised
      more than ever before in the case where we have lots of multicast
      addresses.  Use a hash table instead of a simple linked list, from
      Eric Dumazet.

   3) Add driver for Atheros CQA98xx 802.11ac wireless devices, from
      Bartosz Markowski, Janusz Dziedzic, Kalle Valo, Marek Kwaczynski,
      Marek Puzyniak, Michal Kazior, and Sujith Manoharan.

   4) Support reporting the TUN device persist flag to userspace, from
      Pavel Emelyanov.

   5) Allow controlling network device VF link state using netlink, from
      Rony Efraim.

   6) Support GRE tunneling in openvswitch, from Pravin B Shelar.

   7) Adjust SOCK_MIN_RCVBUF and SOCK_MIN_SNDBUF for modern times, from
      Daniel Borkmann and Eric Dumazet.

   8) Allow controlling of TCP quickack behavior on a per-route basis,
      from Cong Wang.

   9) Several bug fixes and improvements to vxlan from Stephen
      Hemminger, Pravin B Shelar, and Mike Rapoport.  In particular,
      support receiving on multiple UDP ports.

  10) Major cleanups, particular in the area of debugging and cookie
      lifetime handline, to the SCTP protocol code.  From Daniel
      Borkmann.

  11) Allow packets to cross network namespaces when traversing tunnel
      devices.  From Nicolas Dichtel.

  12) Allow monitoring netlink traffic via AF_PACKET sockets, in a
      manner akin to how we monitor real network traffic via ptype_all.
      From Daniel Borkmann.

  13) Several bug fixes and improvements for the new alx device driver,
      from Johannes Berg.

  14) Fix scalability issues in the netem packet scheduler's time queue,
      by using an rbtree.  From Eric Dumazet.

  15) Several bug fixes in TCP loss recovery handling, from Yuchung
      Cheng.

  16) Add support for GSO segmentation of MPLS packets, from Simon
      Horman.

  17) Make network notifiers have a real data type for the opaque
      pointer that's passed into them.  Use this to properly handle
      network device flag changes in arp_netdev_event().  From Jiri
      Pirko and Timo Teräs.

  18) Convert several drivers over to module_pci_driver(), from Peter
      Huewe.

  19) tcp_fixup_rcvbuf() can loop 500 times over loopback, just use a
      O(1) calculation instead.  From Eric Dumazet.

  20) Support setting of explicit tunnel peer addresses in ipv6, just
      like ipv4.  From Nicolas Dichtel.

  21) Protect x86 BPF JIT against spraying attacks, from Eric Dumazet.

  22) Prevent a single high rate flow from overruning an individual cpu
      during RX packet processing via selective flow shedding.  From
      Willem de Bruijn.

  23) Don't use spinlocks in TCP md5 signing fast paths, from Eric
      Dumazet.

  24) Don't just drop GSO packets which are above the TBF scheduler's
      burst limit, chop them up so they are in-bounds instead.  Also
      from Eric Dumazet.

  25) VLAN offloads are missed when configured on top of a bridge, fix
      from Vlad Yasevich.

  26) Support IPV6 in ping sockets.  From Lorenzo Colitti.

  27) Receive flow steering targets should be updated at poll() time
      too, from David Majnemer.

  28) Fix several corner case regressions in PMTU/redirect handling due
      to the routing cache removal, from Timo Teräs.

  29) We have to be mindful of ipv4 mapped ipv6 sockets in
      upd_v6_push_pending_frames().  From Hannes Frederic Sowa.

  30) Fix L2TP sequence number handling bugs, from James Chapman."

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1214 commits)
  drivers/net: caif: fix wrong rtnl_is_locked() usage
  drivers/net: enic: release rtnl_lock on error-path
  vhost-net: fix use-after-free in vhost_net_flush
  net: mv643xx_eth: do not use port number as platform device id
  net: sctp: confirm route during forward progress
  virtio_net: fix race in RX VQ processing
  virtio: support unlocked queue poll
  net/cadence/macb: fix bug/typo in extracting gem_irq_read_clear bit
  Documentation: Fix references to defunct linux-net@vger.kernel.org
  net/fs: change busy poll time accounting
  net: rename low latency sockets functions to busy poll
  bridge: fix some kernel warning in multicast timer
  sfc: Fix memory leak when discarding scattered packets
  sit: fix tunnel update via netlink
  dt:net:stmmac: Add dt specific phy reset callback support.
  dt:net:stmmac: Add support to dwmac version 3.610 and 3.710
  dt:net:stmmac: Allocate platform data only if its NULL.
  net:stmmac: fix memleak in the open method
  ipv6: rt6_check_neigh should successfully verify neigh if no NUD information are available
  net: ipv6: fix wrong ping_v6_sendmsg return value
  ...

39 files changed, 2236 insertions, 1709 deletions

diff --git a/net/ipv4/Kconfig b/net/ipv4/Kconfig
index 8603ca827104..37cf1a6ea3ad 100644
--- a/net/ipv4/Kconfig
+++ b/net/ipv4/Kconfig
@@ -9,10 +9,7 @@ config IP_MULTICAST
 	  intend to participate in the MBONE, a high bandwidth network on top
 	  of the Internet which carries audio and video broadcasts. More
 	  information about the MBONE is on the WWW at
-	  <http://www.savetz.com/mbone/>. Information about the multicast
-	  capabilities of the various network cards is contained in
-	  <file:Documentation/networking/multicast.txt>. For most people, it's
-	  safe to say N.
+	  <http://www.savetz.com/mbone/>. For most people, it's safe to say N.
 
 config IP_ADVANCED_ROUTER
 	bool "IP: advanced router"
@@ -223,10 +220,8 @@ config IP_MROUTE
 	  packets that have several destination addresses. It is needed on the
 	  MBONE, a high bandwidth network on top of the Internet which carries
 	  audio and video broadcasts. In order to do that, you would most
-	  likely run the program mrouted. Information about the multicast
-	  capabilities of the various network cards is contained in
-	  <file:Documentation/networking/multicast.txt>. If you haven't heard
-	  about it, you don't need it.
+	  likely run the program mrouted. If you haven't heard about it, you
+	  don't need it.
 
 config IP_MROUTE_MULTIPLE_TABLES
 	bool "IP: multicast policy routing"
diff --git a/net/ipv4/Makefile b/net/ipv4/Makefile
index 089cb9f36387..4b81e91c80fe 100644
--- a/net/ipv4/Makefile
+++ b/net/ipv4/Makefile
@@ -8,10 +8,10 @@ obj-y     := route.o inetpeer.o protocol.o \
 	     inet_timewait_sock.o inet_connection_sock.o \
 	     tcp.o tcp_input.o tcp_output.o tcp_timer.o tcp_ipv4.o \
 	     tcp_minisocks.o tcp_cong.o tcp_metrics.o tcp_fastopen.o \
-	     datagram.o raw.o udp.o udplite.o \
-	     arp.o icmp.o devinet.o af_inet.o  igmp.o \
+	     tcp_offload.o datagram.o raw.o udp.o udplite.o \
+	     udp_offload.o arp.o icmp.o devinet.o af_inet.o igmp.o \
 	     fib_frontend.o fib_semantics.o fib_trie.o \
-	     inet_fragment.o ping.o
+	     inet_fragment.o ping.o ip_tunnel_core.o
 
 obj-$(CONFIG_NET_IP_TUNNEL) += ip_tunnel.o
 obj-$(CONFIG_SYSCTL) += sysctl_net_ipv4.o
@@ -19,6 +19,7 @@ obj-$(CONFIG_PROC_FS) += proc.o
 obj-$(CONFIG_IP_MULTIPLE_TABLES) += fib_rules.o
 obj-$(CONFIG_IP_MROUTE) += ipmr.o
 obj-$(CONFIG_NET_IPIP) += ipip.o
+gre-y := gre_demux.o gre_offload.o
 obj-$(CONFIG_NET_IPGRE_DEMUX) += gre.o
 obj-$(CONFIG_NET_IPGRE) += ip_gre.o
 obj-$(CONFIG_NET_IPVTI) += ip_vti.o
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index d01be2a3ae53..b4d0be2b7ce9 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1295,6 +1295,7 @@ static struct sk_buff *inet_gso_segment(struct sk_buff *skb,
 		       SKB_GSO_GRE |
 		       SKB_GSO_TCPV6 |
 		       SKB_GSO_UDP_TUNNEL |
+		       SKB_GSO_MPLS |
 		       0)))
 		goto out;
 
@@ -1384,7 +1385,7 @@ static struct sk_buff **inet_gro_receive(struct sk_buff **head,
 		goto out_unlock;
 
 	id = ntohl(*(__be32 *)&iph->id);
-	flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id ^ IP_DF));
+	flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id & ~IP_DF));
 	id >>= 16;
 
 	for (p = *head; p; p = p->next) {
@@ -1406,6 +1407,7 @@ static struct sk_buff **inet_gro_receive(struct sk_buff **head,
 		NAPI_GRO_CB(p)->flush |=
 			(iph->ttl ^ iph2->ttl) |
 			(iph->tos ^ iph2->tos) |
+			(__force int)((iph->frag_off ^ iph2->frag_off) & htons(IP_DF)) |
 			((u16)(ntohs(iph2->id) + NAPI_GRO_CB(p)->count) ^ id);
 
 		NAPI_GRO_CB(p)->flush |= flush;
@@ -1557,15 +1559,6 @@ static const struct net_protocol tcp_protocol = {
 	.netns_ok	=	1,
 };
 
-static const struct net_offload tcp_offload = {
-	.callbacks = {
-		.gso_send_check	=	tcp_v4_gso_send_check,
-		.gso_segment	=	tcp_tso_segment,
-		.gro_receive	=	tcp4_gro_receive,
-		.gro_complete	=	tcp4_gro_complete,
-	},
-};
-
 static const struct net_protocol udp_protocol = {
 	.handler =	udp_rcv,
 	.err_handler =	udp_err,
@@ -1573,13 +1566,6 @@ static const struct net_protocol udp_protocol = {
 	.netns_ok =	1,
 };
 
-static const struct net_offload udp_offload = {
-	.callbacks = {
-		.gso_send_check = udp4_ufo_send_check,
-		.gso_segment = udp4_ufo_fragment,
-	},
-};
-
 static const struct net_protocol icmp_protocol = {
 	.handler =	icmp_rcv,
 	.err_handler =	icmp_err,
@@ -1679,10 +1665,10 @@ static int __init ipv4_offload_init(void)
 	/*
 	 * Add offloads
 	 */
-	if (inet_add_offload(&udp_offload, IPPROTO_UDP) < 0)
+	if (udpv4_offload_init() < 0)
 		pr_crit("%s: Cannot add UDP protocol offload\n", __func__);
-	if (inet_add_offload(&tcp_offload, IPPROTO_TCP) < 0)
-		pr_crit("%s: Cannot add TCP protocol offlaod\n", __func__);
+	if (tcpv4_offload_init() < 0)
+		pr_crit("%s: Cannot add TCP protocol offload\n", __func__);
 
 	dev_add_offload(&ip_packet_offload);
 	return 0;
diff --git a/net/ipv4/ah4.c b/net/ipv4/ah4.c
index 2e7f1948216f..717902669d2f 100644
--- a/net/ipv4/ah4.c
+++ b/net/ipv4/ah4.c
@@ -419,12 +419,9 @@ static void ah4_err(struct sk_buff *skb, u32 info)
 	if (!x)
 		return;
 
-	if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH) {
-		atomic_inc(&flow_cache_genid);
-		rt_genid_bump(net);
-
+	if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
 		ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_AH, 0);
-	} else
+	else
 		ipv4_redirect(skb, net, 0, 0, IPPROTO_AH, 0);
 	xfrm_state_put(x);
 }
diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c
index 247ec1951c35..4429b013f269 100644
--- a/net/ipv4/arp.c
+++ b/net/ipv4/arp.c
@@ -1234,13 +1234,19 @@ out:
 static int arp_netdev_event(struct notifier_block *this, unsigned long event,
 			    void *ptr)
 {
-	struct net_device *dev = ptr;
+	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+	struct netdev_notifier_change_info *change_info;
 
 	switch (event) {
 	case NETDEV_CHANGEADDR:
 		neigh_changeaddr(&arp_tbl, dev);
 		rt_cache_flush(dev_net(dev));
 		break;
+	case NETDEV_CHANGE:
+		change_info = ptr;
+		if (change_info->flags_changed & IFF_NOARP)
+			neigh_changeaddr(&arp_tbl, dev);
+		break;
 	default:
 		break;
 	}
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index dfc39d4d48b7..8d48c392adcc 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -215,6 +215,7 @@ void in_dev_finish_destroy(struct in_device *idev)
 
 	WARN_ON(idev->ifa_list);
 	WARN_ON(idev->mc_list);
+	kfree(rcu_dereference_protected(idev->mc_hash, 1));
 #ifdef NET_REFCNT_DEBUG
 	pr_debug("%s: %p=%s\n", __func__, idev, dev ? dev->name : "NIL");
 #endif
@@ -1333,7 +1334,7 @@ static void inetdev_send_gratuitous_arp(struct net_device *dev,
 static int inetdev_event(struct notifier_block *this, unsigned long event,
 			 void *ptr)
 {
-	struct net_device *dev = ptr;
+	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 	struct in_device *in_dev = __in_dev_get_rtnl(dev);
 
 	ASSERT_RTNL();
@@ -1941,7 +1942,7 @@ static void inet_forward_change(struct net *net)
 	}
 }
 
-static int devinet_conf_proc(ctl_table *ctl, int write,
+static int devinet_conf_proc(struct ctl_table *ctl, int write,
 			     void __user *buffer,
 			     size_t *lenp, loff_t *ppos)
 {
@@ -1984,7 +1985,7 @@ static int devinet_conf_proc(ctl_table *ctl, int write,
 	return ret;
 }
 
-static int devinet_sysctl_forward(ctl_table *ctl, int write,
+static int devinet_sysctl_forward(struct ctl_table *ctl, int write,
 				  void __user *buffer,
 				  size_t *lenp, loff_t *ppos)
 {
@@ -2027,7 +2028,7 @@ static int devinet_sysctl_forward(ctl_table *ctl, int write,
 	return ret;
 }
 
-static int ipv4_doint_and_flush(ctl_table *ctl, int write,
+static int ipv4_doint_and_flush(struct ctl_table *ctl, int write,
 				void __user *buffer,
 				size_t *lenp, loff_t *ppos)
 {
diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c
index 4cfe34d4cc96..ab3d814bc80a 100644
--- a/net/ipv4/esp4.c
+++ b/net/ipv4/esp4.c
@@ -502,12 +502,9 @@ static void esp4_err(struct sk_buff *skb, u32 info)
 	if (!x)
 		return;
 
-	if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH) {
-		atomic_inc(&flow_cache_genid);
-		rt_genid_bump(net);
-
+	if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
 		ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_ESP, 0);
-	} else
+	else
 		ipv4_redirect(skb, net, 0, 0, IPPROTO_ESP, 0);
 	xfrm_state_put(x);
 }
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index c7629a209f9d..b3f627ac4ed8 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -961,7 +961,7 @@ static void nl_fib_input(struct sk_buff *skb)
 	    nlmsg_len(nlh) < sizeof(*frn))
 		return;
 
-	skb = skb_clone(skb, GFP_KERNEL);
+	skb = netlink_skb_clone(skb, GFP_KERNEL);
 	if (skb == NULL)
 		return;
 	nlh = nlmsg_hdr(skb);
@@ -1038,7 +1038,7 @@ static int fib_inetaddr_event(struct notifier_block *this, unsigned long event,
 
 static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
 {
-	struct net_device *dev = ptr;
+	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 	struct in_device *in_dev;
 	struct net *net = dev_net(dev);
 
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index 8f6cb7a87cd6..d5dbca5ecf62 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -169,7 +169,8 @@ static void free_nh_exceptions(struct fib_nh *nh)
 			
 			next = rcu_dereference_protected(fnhe->fnhe_next, 1);
 
-			rt_fibinfo_free(&fnhe->fnhe_rth);
+			rt_fibinfo_free(&fnhe->fnhe_rth_input);
+			rt_fibinfo_free(&fnhe->fnhe_rth_output);
 
 			kfree(fnhe);
 
diff --git a/net/ipv4/gre.c b/net/ipv4/gre.c
deleted file mode 100644
index 7856d1651d05..000000000000
--- a/net/ipv4/gre.c
+++ /dev/null
@@ -1,253 +0,0 @@
-/*
- *	GRE over IPv4 demultiplexer driver
- *
- *	Authors: Dmitry Kozlov (xeb@mail.ru)
- *
- *	This program is free software; you can redistribute it and/or
- *	modify it under the terms of the GNU General Public License
- *	as published by the Free Software Foundation; either version
- *	2 of the License, or (at your option) any later version.
- *
- */
-
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-
-#include <linux/module.h>
-#include <linux/kernel.h>
-#include <linux/kmod.h>
-#include <linux/skbuff.h>
-#include <linux/in.h>
-#include <linux/ip.h>
-#include <linux/netdevice.h>
-#include <linux/if_tunnel.h>
-#include <linux/spinlock.h>
-#include <net/protocol.h>
-#include <net/gre.h>
-
-
-static const struct gre_protocol __rcu *gre_proto[GREPROTO_MAX] __read_mostly;
-static DEFINE_SPINLOCK(gre_proto_lock);
-
-int gre_add_protocol(const struct gre_protocol *proto, u8 version)
-{
-	if (version >= GREPROTO_MAX)
-		goto err_out;
-
-	spin_lock(&gre_proto_lock);
-	if (gre_proto[version])
-		goto err_out_unlock;
-
-	RCU_INIT_POINTER(gre_proto[version], proto);
-	spin_unlock(&gre_proto_lock);
-	return 0;
-
-err_out_unlock:
-	spin_unlock(&gre_proto_lock);
-err_out:
-	return -1;
-}
-EXPORT_SYMBOL_GPL(gre_add_protocol);
-
-int gre_del_protocol(const struct gre_protocol *proto, u8 version)
-{
-	if (version >= GREPROTO_MAX)
-		goto err_out;
-
-	spin_lock(&gre_proto_lock);
-	if (rcu_dereference_protected(gre_proto[version],
-			lockdep_is_held(&gre_proto_lock)) != proto)
-		goto err_out_unlock;
-	RCU_INIT_POINTER(gre_proto[version], NULL);
-	spin_unlock(&gre_proto_lock);
-	synchronize_rcu();
-	return 0;
-
-err_out_unlock:
-	spin_unlock(&gre_proto_lock);
-err_out:
-	return -1;
-}
-EXPORT_SYMBOL_GPL(gre_del_protocol);
-
-static int gre_rcv(struct sk_buff *skb)
-{
-	const struct gre_protocol *proto;
-	u8 ver;
-	int ret;
-
-	if (!pskb_may_pull(skb, 12))
-		goto drop;
-
-	ver = skb->data[1]&0x7f;
-	if (ver >= GREPROTO_MAX)
-		goto drop;
-
-	rcu_read_lock();
-	proto = rcu_dereference(gre_proto[ver]);
-	if (!proto || !proto->handler)
-		goto drop_unlock;
-	ret = proto->handler(skb);
-	rcu_read_unlock();
-	return ret;
-
-drop_unlock:
-	rcu_read_unlock();
-drop:
-	kfree_skb(skb);
-	return NET_RX_DROP;
-}
-
-static void gre_err(struct sk_buff *skb, u32 info)
-{
-	const struct gre_protocol *proto;
-	const struct iphdr *iph = (const struct iphdr *)skb->data;
-	u8 ver = skb->data[(iph->ihl<<2) + 1]&0x7f;
-
-	if (ver >= GREPROTO_MAX)
-		return;
-
-	rcu_read_lock();
-	proto = rcu_dereference(gre_proto[ver]);
-	if (proto && proto->err_handler)
-		proto->err_handler(skb, info);
-	rcu_read_unlock();
-}
-
-static struct sk_buff *gre_gso_segment(struct sk_buff *skb,
-				       netdev_features_t features)
-{
-	struct sk_buff *segs = ERR_PTR(-EINVAL);
-	netdev_features_t enc_features;
-	int ghl = GRE_HEADER_SECTION;
-	struct gre_base_hdr *greh;
-	int mac_len = skb->mac_len;
-	__be16 protocol = skb->protocol;
-	int tnl_hlen;
-	bool csum;
-
-	if (unlikely(skb_shinfo(skb)->gso_type &
-				~(SKB_GSO_TCPV4 |
-				  SKB_GSO_TCPV6 |
-				  SKB_GSO_UDP |
-				  SKB_GSO_DODGY |
-				  SKB_GSO_TCP_ECN |
-				  SKB_GSO_GRE)))
-		goto out;
-
-	if (unlikely(!pskb_may_pull(skb, sizeof(*greh))))
-		goto out;
-
-	greh = (struct gre_base_hdr *)skb_transport_header(skb);
-
-	if (greh->flags & GRE_KEY)
-		ghl += GRE_HEADER_SECTION;
-	if (greh->flags & GRE_SEQ)
-		ghl += GRE_HEADER_SECTION;
-	if (greh->flags & GRE_CSUM) {
-		ghl += GRE_HEADER_SECTION;
-		csum = true;
-	} else
-		csum = false;
-
-	/* setup inner skb. */
-	skb->protocol = greh->protocol;
-	skb->encapsulation = 0;
-
-	if (unlikely(!pskb_may_pull(skb, ghl)))
-		goto out;
-	__skb_pull(skb, ghl);
-	skb_reset_mac_header(skb);
-	skb_set_network_header(skb, skb_inner_network_offset(skb));
-	skb->mac_len = skb_inner_network_offset(skb);
-
-	/* segment inner packet. */
-	enc_features = skb->dev->hw_enc_features & netif_skb_features(skb);
-	segs = skb_mac_gso_segment(skb, enc_features);
-	if (!segs || IS_ERR(segs))
-		goto out;
-
-	skb = segs;
-	tnl_hlen = skb_tnl_header_len(skb);
-	do {
-		__skb_push(skb, ghl);
-		if (csum) {
-			__be32 *pcsum;
-
-			if (skb_has_shared_frag(skb)) {
-				int err;
-
-				err = __skb_linearize(skb);
-				if (err) {
-					kfree_skb_list(segs);
-					segs = ERR_PTR(err);
-					goto out;
-				}
-			}
-
-			greh = (struct gre_base_hdr *)(skb->data);
-			pcsum = (__be32 *)(greh + 1);
-			*pcsum = 0;
-			*(__sum16 *)pcsum = csum_fold(skb_checksum(skb, 0, skb->len, 0));
-		}
-		__skb_push(skb, tnl_hlen - ghl);
-
-		skb_reset_mac_header(skb);
-		skb_set_network_header(skb, mac_len);
-		skb->mac_len = mac_len;
-		skb->protocol = protocol;
-	} while ((skb = skb->next));
-out:
-	return segs;
-}
-
-static int gre_gso_send_check(struct sk_buff *skb)
-{
-	if (!skb->encapsulation)
-		return -EINVAL;
-	return 0;
-}
-
-static const struct net_protocol net_gre_protocol = {
-	.handler     = gre_rcv,
-	.err_handler = gre_err,
-	.netns_ok    = 1,
-};
-
-static const struct net_offload gre_offload = {
-	.callbacks = {
-		.gso_send_check =	gre_gso_send_check,
-		.gso_segment    =	gre_gso_segment,
-	},
-};
-
-static int __init gre_init(void)
-{
-	pr_info("GRE over IPv4 demultiplexor driver\n");
-
-	if (inet_add_protocol(&net_gre_protocol, IPPROTO_GRE) < 0) {
-		pr_err("can't add protocol\n");
-		return -EAGAIN;
-	}
-
-	if (inet_add_offload(&gre_offload, IPPROTO_GRE)) {
-		pr_err("can't add protocol offload\n");
-		inet_del_protocol(&net_gre_protocol, IPPROTO_GRE);
-		return -EAGAIN;
-	}
-
-	return 0;
-}
-
-static void __exit gre_exit(void)
-{
-	inet_del_offload(&gre_offload, IPPROTO_GRE);
-	inet_del_protocol(&net_gre_protocol, IPPROTO_GRE);
-}
-
-module_init(gre_init);
-module_exit(gre_exit);
-
-MODULE_DESCRIPTION("GRE over IPv4 demultiplexer driver");
-MODULE_AUTHOR("D. Kozlov (xeb@mail.ru)");
-MODULE_LICENSE("GPL");
-
diff --git a/net/ipv4/gre_demux.c b/net/ipv4/gre_demux.c
new file mode 100644
index 000000000000..736c9fc3ef93
--- /dev/null
+++ b/net/ipv4/gre_demux.c
@@ -0,0 +1,414 @@
+/*
+ *	GRE over IPv4 demultiplexer driver
+ *
+ *	Authors: Dmitry Kozlov (xeb@mail.ru)
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/if.h>
+#include <linux/icmp.h>
+#include <linux/kernel.h>
+#include <linux/kmod.h>
+#include <linux/skbuff.h>
+#include <linux/in.h>
+#include <linux/ip.h>
+#include <linux/netdevice.h>
+#include <linux/if_tunnel.h>
+#include <linux/spinlock.h>
+#include <net/protocol.h>
+#include <net/gre.h>
+
+#include <net/icmp.h>
+#include <net/route.h>
+#include <net/xfrm.h>
+
+static const struct gre_protocol __rcu *gre_proto[GREPROTO_MAX] __read_mostly;
+static struct gre_cisco_protocol __rcu *gre_cisco_proto_list[GRE_IP_PROTO_MAX];
+
+int gre_add_protocol(const struct gre_protocol *proto, u8 version)
+{
+	if (version >= GREPROTO_MAX)
+		return -EINVAL;
+
+	return (cmpxchg((const struct gre_protocol **)&gre_proto[version], NULL, proto) == NULL) ?
+		0 : -EBUSY;
+}
+EXPORT_SYMBOL_GPL(gre_add_protocol);
+
+int gre_del_protocol(const struct gre_protocol *proto, u8 version)
+{
+	int ret;
+
+	if (version >= GREPROTO_MAX)
+		return -EINVAL;
+
+	ret = (cmpxchg((const struct gre_protocol **)&gre_proto[version], proto, NULL) == proto) ?
+		0 : -EBUSY;
+
+	if (ret)
+		return ret;
+
+	synchronize_rcu();
+	return 0;
+}
+EXPORT_SYMBOL_GPL(gre_del_protocol);
+
+void gre_build_header(struct sk_buff *skb, const struct tnl_ptk_info *tpi,
+		      int hdr_len)
+{
+	struct gre_base_hdr *greh;
+
+	skb_push(skb, hdr_len);
+
+	greh = (struct gre_base_hdr *)skb->data;
+	greh->flags = tnl_flags_to_gre_flags(tpi->flags);
+	greh->protocol = tpi->proto;
+
+	if (tpi->flags&(TUNNEL_KEY|TUNNEL_CSUM|TUNNEL_SEQ)) {
+		__be32 *ptr = (__be32 *)(((u8 *)greh) + hdr_len - 4);
+
+		if (tpi->flags&TUNNEL_SEQ) {
+			*ptr = tpi->seq;
+			ptr--;
+		}
+		if (tpi->flags&TUNNEL_KEY) {
+			*ptr = tpi->key;
+			ptr--;
+		}
+		if (tpi->flags&TUNNEL_CSUM &&
+		    !(skb_shinfo(skb)->gso_type & SKB_GSO_GRE)) {
+			*ptr = 0;
+			*(__sum16 *)ptr = csum_fold(skb_checksum(skb, 0,
+								 skb->len, 0));
+		}
+	}
+}
+EXPORT_SYMBOL_GPL(gre_build_header);
+
+struct sk_buff *gre_handle_offloads(struct sk_buff *skb, bool gre_csum)
+{
+	int err;
+
+	if (likely(!skb->encapsulation)) {
+		skb_reset_inner_headers(skb);
+		skb->encapsulation = 1;
+	}
+
+	if (skb_is_gso(skb)) {
+		err = skb_unclone(skb, GFP_ATOMIC);
+		if (unlikely(err))
+			goto error;
+		skb_shinfo(skb)->gso_type |= SKB_GSO_GRE;
+		return skb;
+	} else if (skb->ip_summed == CHECKSUM_PARTIAL && gre_csum) {
+		err = skb_checksum_help(skb);
+		if (unlikely(err))
+			goto error;
+	} else if (skb->ip_summed != CHECKSUM_PARTIAL)
+		skb->ip_summed = CHECKSUM_NONE;
+
+	return skb;
+error:
+	kfree_skb(skb);
+	return ERR_PTR(err);
+}
+EXPORT_SYMBOL_GPL(gre_handle_offloads);
+
+static __sum16 check_checksum(struct sk_buff *skb)
+{
+	__sum16 csum = 0;
+
+	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;
+		break;
+	}
+
+	return csum;
+}
+
+static int parse_gre_header(struct sk_buff *skb, struct tnl_ptk_info *tpi,
+			    bool *csum_err)
+{
+	unsigned int ip_hlen = ip_hdrlen(skb);
+	const struct gre_base_hdr *greh;
+	__be32 *options;
+	int hdr_len;
+
+	if (unlikely(!pskb_may_pull(skb, sizeof(struct gre_base_hdr))))
+		return -EINVAL;
+
+	greh = (struct gre_base_hdr *)(skb_network_header(skb) + ip_hlen);
+	if (unlikely(greh->flags & (GRE_VERSION | GRE_ROUTING)))
+		return -EINVAL;
+
+	tpi->flags = gre_flags_to_tnl_flags(greh->flags);
+	hdr_len = ip_gre_calc_hlen(tpi->flags);
+
+	if (!pskb_may_pull(skb, hdr_len))
+		return -EINVAL;
+
+	greh = (struct gre_base_hdr *)(skb_network_header(skb) + ip_hlen);
+	tpi->proto = greh->protocol;
+
+	options = (__be32 *)(greh + 1);
+	if (greh->flags & GRE_CSUM) {
+		if (check_checksum(skb)) {
+			*csum_err = true;
+			return -EINVAL;
+		}
+		options++;
+	}
+
+	if (greh->flags & GRE_KEY) {
+		tpi->key = *options;
+		options++;
+	} else
+		tpi->key = 0;
+
+	if (unlikely(greh->flags & GRE_SEQ)) {
+		tpi->seq = *options;
+		options++;
+	} else
+		tpi->seq = 0;
+
+	/* WCCP version 1 and 2 protocol decoding.
+	 * - Change protocol to IP
+	 * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header
+