18 files changed, 348 insertions, 110 deletions

diff --git a/net/ipv4/netfilter/Kconfig b/net/ipv4/netfilter/Kconfig
index c11eb1744ab1..7d5d444964aa 100644
--- a/net/ipv4/netfilter/Kconfig
+++ b/net/ipv4/netfilter/Kconfig
@@ -72,11 +72,20 @@ endif # NF_TABLES_IPV4
 
 config NF_TABLES_ARP
 	tristate "ARP nf_tables support"
+	select NETFILTER_FAMILY_ARP
 	help
 	  This option enables the ARP support for nf_tables.
 
 endif # NF_TABLES
 
+config NF_FLOW_TABLE_IPV4
+	select NF_FLOW_TABLE
+	tristate "Netfilter flow table IPv4 module"
+	help
+	  This option adds the flow table IPv4 support.
+
+	  To compile it as a module, choose M here.
+
 config NF_DUP_IPV4
 	tristate "Netfilter IPv4 packet duplication to alternate destination"
 	depends on !NF_CONNTRACK || NF_CONNTRACK
@@ -392,6 +401,7 @@ endif # IP_NF_IPTABLES
 config IP_NF_ARPTABLES
 	tristate "ARP tables support"
 	select NETFILTER_XTABLES
+	select NETFILTER_FAMILY_ARP
 	depends on NETFILTER_ADVANCED
 	help
 	  arptables is a general, extensible packet identification framework.
diff --git a/net/ipv4/netfilter/Makefile b/net/ipv4/netfilter/Makefile
index adcdae358365..8bb1f0c7a375 100644
--- a/net/ipv4/netfilter/Makefile
+++ b/net/ipv4/netfilter/Makefile
@@ -43,6 +43,9 @@ obj-$(CONFIG_NFT_REDIR_IPV4) += nft_redir_ipv4.o
 obj-$(CONFIG_NFT_DUP_IPV4) += nft_dup_ipv4.o
 obj-$(CONFIG_NF_TABLES_ARP) += nf_tables_arp.o
 
+# flow table support
+obj-$(CONFIG_NF_FLOW_TABLE_IPV4) += nf_flow_table_ipv4.o
+
 # generic IP tables 
 obj-$(CONFIG_IP_NF_IPTABLES) += ip_tables.o
 
diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index 0c3c944a7b72..bf8a5340f15e 100644
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -810,9 +810,8 @@ static int get_info(struct net *net, void __user *user,
 	if (compat)
 		xt_compat_lock(NFPROTO_ARP);
 #endif
-	t = try_then_request_module(xt_find_table_lock(net, NFPROTO_ARP, name),
-				    "arptable_%s", name);
-	if (t) {
+	t = xt_request_find_table_lock(net, NFPROTO_ARP, name);
+	if (!IS_ERR(t)) {
 		struct arpt_getinfo info;
 		const struct xt_table_info *private = t->private;
 #ifdef CONFIG_COMPAT
@@ -841,7 +840,7 @@ static int get_info(struct net *net, void __user *user,
 		xt_table_unlock(t);
 		module_put(t->me);
 	} else
-		ret = -ENOENT;
+		ret = PTR_ERR(t);
 #ifdef CONFIG_COMPAT
 	if (compat)
 		xt_compat_unlock(NFPROTO_ARP);
@@ -866,7 +865,7 @@ static int get_entries(struct net *net, struct arpt_get_entries __user *uptr,
 	get.name[sizeof(get.name) - 1] = '\0';
 
 	t = xt_find_table_lock(net, NFPROTO_ARP, get.name);
-	if (t) {
+	if (!IS_ERR(t)) {
 		const struct xt_table_info *private = t->private;
 
 		if (get.size == private->size)
@@ -878,7 +877,7 @@ static int get_entries(struct net *net, struct arpt_get_entries __user *uptr,
 		module_put(t->me);
 		xt_table_unlock(t);
 	} else
-		ret = -ENOENT;
+		ret = PTR_ERR(t);
 
 	return ret;
 }
@@ -903,10 +902,9 @@ static int __do_replace(struct net *net, const char *name,
 		goto out;
 	}
 
-	t = try_then_request_module(xt_find_table_lock(net, NFPROTO_ARP, name),
-				    "arptable_%s", name);
-	if (!t) {
-		ret = -ENOENT;
+	t = xt_request_find_table_lock(net, NFPROTO_ARP, name);
+	if (IS_ERR(t)) {
+		ret = PTR_ERR(t);
 		goto free_newinfo_counters_untrans;
 	}
 
@@ -1020,8 +1018,8 @@ static int do_add_counters(struct net *net, const void __user *user,
 		return PTR_ERR(paddc);
 
 	t = xt_find_table_lock(net, NFPROTO_ARP, tmp.name);
-	if (!t) {
-		ret = -ENOENT;
+	if (IS_ERR(t)) {
+		ret = PTR_ERR(t);
 		goto free;
 	}
 
@@ -1408,7 +1406,7 @@ static int compat_get_entries(struct net *net,
 
 	xt_compat_lock(NFPROTO_ARP);
 	t = xt_find_table_lock(net, NFPROTO_ARP, get.name);
-	if (t) {
+	if (!IS_ERR(t)) {
 		const struct xt_table_info *private = t->private;
 		struct xt_table_info info;
 
@@ -1423,7 +1421,7 @@ static int compat_get_entries(struct net *net,
 		module_put(t->me);
 		xt_table_unlock(t);
 	} else
-		ret = -ENOENT;
+		ret = PTR_ERR(t);
 
 	xt_compat_unlock(NFPROTO_ARP);
 	return ret;
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index 2e0d339028bb..0b975aa2d363 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -973,9 +973,8 @@ static int get_info(struct net *net, void __user *user,
 	if (compat)
 		xt_compat_lock(AF_INET);
 #endif
-	t = try_then_request_module(xt_find_table_lock(net, AF_INET, name),
-				    "iptable_%s", name);
-	if (t) {
+	t = xt_request_find_table_lock(net, AF_INET, name);
+	if (!IS_ERR(t)) {
 		struct ipt_getinfo info;
 		const struct xt_table_info *private = t->private;
 #ifdef CONFIG_COMPAT
@@ -1005,7 +1004,7 @@ static int get_info(struct net *net, void __user *user,
 		xt_table_unlock(t);
 		module_put(t->me);
 	} else
-		ret = -ENOENT;
+		ret = PTR_ERR(t);
 #ifdef CONFIG_COMPAT
 	if (compat)
 		xt_compat_unlock(AF_INET);
@@ -1030,7 +1029,7 @@ get_entries(struct net *net, struct ipt_get_entries __user *uptr,
 	get.name[sizeof(get.name) - 1] = '\0';
 
 	t = xt_find_table_lock(net, AF_INET, get.name);
-	if (t) {
+	if (!IS_ERR(t)) {
 		const struct xt_table_info *private = t->private;
 		if (get.size == private->size)
 			ret = copy_entries_to_user(private->size,
@@ -1041,7 +1040,7 @@ get_entries(struct net *net, struct ipt_get_entries __user *uptr,
 		module_put(t->me);
 		xt_table_unlock(t);
 	} else
-		ret = -ENOENT;
+		ret = PTR_ERR(t);
 
 	return ret;
 }
@@ -1064,10 +1063,9 @@ __do_replace(struct net *net, const char *name, unsigned int valid_hooks,
 		goto out;
 	}
 
-	t = try_then_request_module(xt_find_table_lock(net, AF_INET, name),
-				    "iptable_%s", name);
-	if (!t) {
-		ret = -ENOENT;
+	t = xt_request_find_table_lock(net, AF_INET, name);
+	if (IS_ERR(t)) {
+		ret = PTR_ERR(t);
 		goto free_newinfo_counters_untrans;
 	}
 
@@ -1181,8 +1179,8 @@ do_add_counters(struct net *net, const void __user *user,
 		return PTR_ERR(paddc);
 
 	t = xt_find_table_lock(net, AF_INET, tmp.name);
-	if (!t) {
-		ret = -ENOENT;
+	if (IS_ERR(t)) {
+		ret = PTR_ERR(t);
 		goto free;
 	}
 
@@ -1625,7 +1623,7 @@ compat_get_entries(struct net *net, struct compat_ipt_get_entries __user *uptr,
 
 	xt_compat_lock(AF_INET);
 	t = xt_find_table_lock(net, AF_INET, get.name);
-	if (t) {
+	if (!IS_ERR(t)) {
 		const struct xt_table_info *private = t->private;
 		struct xt_table_info info;
 		ret = compat_table_info(private, &info);
@@ -1639,7 +1637,7 @@ compat_get_entries(struct net *net, struct compat_ipt_get_entries __user *uptr,
 		module_put(t->me);
 		xt_table_unlock(t);
 	} else
-		ret = -ENOENT;
+		ret = PTR_ERR(t);
 
 	xt_compat_unlock(AF_INET);
 	return ret;
diff --git a/net/ipv4/netfilter/ipt_CLUSTERIP.c b/net/ipv4/netfilter/ipt_CLUSTERIP.c
index 69060e3abe85..c29a6ca6c6d6 100644
--- a/net/ipv4/netfilter/ipt_CLUSTERIP.c
+++ b/net/ipv4/netfilter/ipt_CLUSTERIP.c
@@ -776,7 +776,6 @@ static ssize_t clusterip_proc_write(struct file *file, const char __user *input,
 }
 
 static const struct file_operations clusterip_proc_fops = {
-	.owner	 = THIS_MODULE,
 	.open	 = clusterip_proc_open,
 	.read	 = seq_read,
 	.write	 = clusterip_proc_write,
diff --git a/net/ipv4/netfilter/iptable_filter.c b/net/ipv4/netfilter/iptable_filter.c
index 7667f223d7f8..9ac92ea7b93c 100644
--- a/net/ipv4/netfilter/iptable_filter.c
+++ b/net/ipv4/netfilter/iptable_filter.c
@@ -38,12 +38,6 @@ static unsigned int
 iptable_filter_hook(void *priv, struct sk_buff *skb,
 		    const struct nf_hook_state *state)
 {
-	if (state->hook == NF_INET_LOCAL_OUT &&
-	    (skb->len < sizeof(struct iphdr) ||
-	     ip_hdrlen(skb) < sizeof(struct iphdr)))
-		/* root is playing with raw sockets. */
-		return NF_ACCEPT;
-
 	return ipt_do_table(skb, state, state->net->ipv4.iptable_filter);
 }
 
diff --git a/net/ipv4/netfilter/iptable_mangle.c b/net/ipv4/netfilter/iptable_mangle.c
index aebdb337fd7e..dea138ca8925 100644
--- a/net/ipv4/netfilter/iptable_mangle.c
+++ b/net/ipv4/netfilter/iptable_mangle.c
@@ -49,11 +49,6 @@ ipt_mangle_out(struct sk_buff *skb, const struct nf_hook_state *state)
 	u_int32_t mark;
 	int err;
 
-	/* root is playing with raw sockets. */
-	if (skb->len < sizeof(struct iphdr) ||
-	    ip_hdrlen(skb) < sizeof(struct iphdr))
-		return NF_ACCEPT;
-
 	/* Save things which could affect route */
 	mark = skb->mark;
 	iph = ip_hdr(skb);
diff --git a/net/ipv4/netfilter/iptable_nat.c b/net/ipv4/netfilter/iptable_nat.c
index a1a07b338ccf..0f7255cc65ee 100644
--- a/net/ipv4/netfilter/iptable_nat.c
+++ b/net/ipv4/netfilter/iptable_nat.c
@@ -72,6 +72,7 @@ static const struct nf_hook_ops nf_nat_ipv4_ops[] = {
 	{
 		.hook		= iptable_nat_ipv4_in,
 		.pf		= NFPROTO_IPV4,
+		.nat_hook	= true,
 		.hooknum	= NF_INET_PRE_ROUTING,
 		.priority	= NF_IP_PRI_NAT_DST,
 	},
@@ -79,6 +80,7 @@ static const struct nf_hook_ops nf_nat_ipv4_ops[] = {
 	{
 		.hook		= iptable_nat_ipv4_out,
 		.pf		= NFPROTO_IPV4,
+		.nat_hook	= true,
 		.hooknum	= NF_INET_POST_ROUTING,
 		.priority	= NF_IP_PRI_NAT_SRC,
 	},
@@ -86,6 +88,7 @@ static const struct nf_hook_ops nf_nat_ipv4_ops[] = {
 	{
 		.hook		= iptable_nat_ipv4_local_fn,
 		.pf		= NFPROTO_IPV4,
+		.nat_hook	= true,
 		.hooknum	= NF_INET_LOCAL_OUT,
 		.priority	= NF_IP_PRI_NAT_DST,
 	},
@@ -93,6 +96,7 @@ static const struct nf_hook_ops nf_nat_ipv4_ops[] = {
 	{
 		.hook		= iptable_nat_ipv4_fn,
 		.pf		= NFPROTO_IPV4,
+		.nat_hook	= true,
 		.hooknum	= NF_INET_LOCAL_IN,
 		.priority	= NF_IP_PRI_NAT_SRC,
 	},
diff --git a/net/ipv4/netfilter/iptable_raw.c b/net/ipv4/netfilter/iptable_raw.c
index 2642ecd2645c..a869d1fea7d9 100644
--- a/net/ipv4/netfilter/iptable_raw.c
+++ b/net/ipv4/netfilter/iptable_raw.c
@@ -26,12 +26,6 @@ static unsigned int
 iptable_raw_hook(void *priv, struct sk_buff *skb,
 		 const struct nf_hook_state *state)
 {
-	if (state->hook == NF_INET_LOCAL_OUT &&
-	    (skb->len < sizeof(struct iphdr) ||
-	     ip_hdrlen(skb) < sizeof(struct iphdr)))
-		/* root is playing with raw sockets. */
-		return NF_ACCEPT;
-
 	return ipt_do_table(skb, state, state->net->ipv4.iptable_raw);
 }
 
diff --git a/net/ipv4/netfilter/iptable_security.c b/net/ipv4/netfilter/iptable_security.c
index ff226596e4b5..e5379fe57b64 100644
--- a/net/ipv4/netfilter/iptable_security.c
+++ b/net/ipv4/netfilter/iptable_security.c
@@ -43,12 +43,6 @@ static unsigned int
 iptable_security_hook(void *priv, struct sk_buff *skb,
 		      const struct nf_hook_state *state)
 {
-	if (state->hook == NF_INET_LOCAL_OUT &&
-	    (skb->len < sizeof(struct iphdr) ||
-	     ip_hdrlen(skb) < sizeof(struct iphdr)))
-		/* Somebody is playing with raw sockets. */
-		return NF_ACCEPT;
-
 	return ipt_do_table(skb, state, state->net->ipv4.iptable_security);
 }
 
diff --git a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
index 89af9d88ca21..de213a397ea8 100644
--- a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
+++ b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
@@ -154,11 +154,6 @@ static unsigned int ipv4_conntrack_local(void *priv,
 					 struct sk_buff *skb,
 					 const struct nf_hook_state *state)
 {
-	/* root is playing with raw sockets. */
-	if (skb->len < sizeof(struct iphdr) ||
-	    ip_hdrlen(skb) < sizeof(struct iphdr))
-		return NF_ACCEPT;
-
 	if (ip_is_fragment(ip_hdr(skb))) /* IP_NODEFRAG setsockopt set */
 		return NF_ACCEPT;
 
@@ -368,7 +363,7 @@ MODULE_ALIAS("nf_conntrack-" __stringify(AF_INET));
 MODULE_ALIAS("ip_conntrack");
 MODULE_LICENSE("GPL");
 
-static struct nf_conntrack_l4proto *builtin_l4proto4[] = {
+static const struct nf_conntrack_l4proto * const builtin_l4proto4[] = {
 	&nf_conntrack_l4proto_tcp4,
 	&nf_conntrack_l4proto_udp4,
 	&nf_conntrack_l4proto_icmp,
diff --git a/net/ipv4/netfilter/nf_conntrack_proto_icmp.c b/net/ipv4/netfilter/nf_conntrack_proto_icmp.c
index 1849fedd9b81..5c15beafa711 100644
--- a/net/ipv4/netfilter/nf_conntrack_proto_icmp.c
+++ b/net/ipv4/netfilter/nf_conntrack_proto_icmp.c
@@ -22,7 +22,7 @@
 #include <net/netfilter/nf_conntrack_zones.h>
 #include <net/netfilter/nf_log.h>
 
-static unsigned int nf_ct_icmp_timeout __read_mostly = 30*HZ;
+static const unsigned int nf_ct_icmp_timeout = 30*HZ;
 
 static inline struct nf_icmp_net *icmp_pernet(struct net *net)
 {
@@ -351,7 +351,7 @@ static struct nf_proto_net *icmp_get_net_proto(struct net *net)
 	return &net->ct.nf_ct_proto.icmp.pn;
 }
 
-struct nf_conntrack_l4proto nf_conntrack_l4proto_icmp __read_mostly =
+const struct nf_conntrack_l4proto nf_conntrack_l4proto_icmp =
 {
 	.l3proto		= PF_INET,
 	.l4proto		= IPPROTO_ICMP,
diff --git a/net/ipv4/netfilter/nf_flow_table_ipv4.c b/net/ipv4/netfilter/nf_flow_table_ipv4.c
new file mode 100644
index 000000000000..b2d01eb25f2c
--- /dev/null
+++ b/net/ipv4/netfilter/nf_flow_table_ipv4.c
@@ -0,0 +1,284 @@
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/netfilter.h>
+#include <linux/rhashtable.h>
+#include <linux/ip.h>
+#include <linux/netdevice.h>
+#include <net/ip.h>
+#include <net/neighbour.h>
+#include <net/netfilter/nf_flow_table.h>
+#include <net/netfilter/nf_tables.h>
+/* For layer 4 checksum field offset. */
+#include <linux/tcp.h>
+#include <linux/udp.h>
+
+static int nf_flow_nat_ip_tcp(struct sk_buff *skb, unsigned int thoff,
+			      __be32 addr, __be32 new_addr)
+{
+	struct tcphdr *tcph;
+
+	if (!pskb_may_pull(skb, thoff + sizeof(*tcph)) ||
+	    skb_try_make_writable(skb, thoff + sizeof(*tcph)))
+		return -1;
+
+	tcph = (void *)(skb_network_header(skb) + thoff);
+	inet_proto_csum_replace4(&tcph->check, skb, addr, new_addr, true);
+
+	return 0;
+}
+
+static int nf_flow_nat_ip_udp(struct sk_buff *skb, unsigned int thoff,
+			      __be32 addr, __be32 new_addr)
+{
+	struct udphdr *udph;
+
+	if (!pskb_may_pull(skb, thoff + sizeof(*udph)) ||
+	    skb_try_make_writable(skb, thoff + sizeof(*udph)))
+		return -1;
+
+	udph = (void *)(skb_network_header(skb) + thoff);
+	if (udph->check || skb->ip_summed == CHECKSUM_PARTIAL) {
+		inet_proto_csum_replace4(&udph->check, skb, addr,
+					 new_addr, true);
+		if (!udph->check)
+			udph->check = CSUM_MANGLED_0;
+	}
+
+	return 0;
+}
+
+static int nf_flow_nat_ip_l4proto(struct sk_buff *skb, struct iphdr *iph,
+				  unsigned int thoff, __be32 addr,
+				  __be32 new_addr)
+{
+	switch (iph->protocol) {
+	case IPPROTO_TCP:
+		if (nf_flow_nat_ip_tcp(skb, thoff, addr, new_addr) < 0)
+			return NF_DROP;
+		break;
+	case IPPROTO_UDP:
+		if (nf_flow_nat_ip_udp(skb, thoff, addr, new_addr) < 0)
+			return NF_DROP;
+		break;
+	}
+
+	return 0;
+}
+
+static int nf_flow_snat_ip(const struct flow_offload *flow, struct sk_buff *skb,
+			   struct iphdr *iph, unsigned int thoff,
+			   enum flow_offload_tuple_dir dir)
+{
+	__be32 addr, new_addr;
+
+	switch (dir) {
+	case FLOW_OFFLOAD_DIR_ORIGINAL:
+		addr = iph->saddr;
+		new_addr = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.dst_v4.s_addr;
+		iph->saddr = new_addr;
+		break;
+	case FLOW_OFFLOAD_DIR_REPLY:
+		addr = iph->daddr;
+		new_addr = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.src_v4.s_addr;
+		iph->daddr = new_addr;
+		break;
+	default:
+		return -1;
+	}
+	csum_replace4(&iph->check, addr, new_addr);
+
+	return nf_flow_nat_ip_l4proto(skb, iph, thoff, addr, new_addr);
+}
+
+static int nf_flow_dnat_ip(const struct flow_offload *flow, struct sk_buff *skb,
+			   struct iphdr *iph, unsigned int thoff,
+			   enum flow_offload_tuple_dir dir)
+{
+	__be32 addr, new_addr;
+
+	switch (dir) {
+	case FLOW_OFFLOAD_DIR_ORIGINAL:
+		addr = iph->daddr;
+		new_addr = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.src_v4.s_addr;
+		iph->daddr = new_addr;
+		break;
+	case FLOW_OFFLOAD_DIR_REPLY:
+		addr = iph->saddr;
+		new_addr = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.dst_v4.s_addr;
+		iph->saddr = new_addr;
+		break;
+	default:
+		return -1;
+	}
+
+	return nf_flow_nat_ip_l4proto(skb, iph, thoff, addr, new_addr);
+}
+
+static int nf_flow_nat_ip(const struct flow_offload *flow, struct sk_buff *skb,
+			  enum flow_offload_tuple_dir dir)
+{
+	struct iphdr *iph = ip_hdr(skb);
+	unsigned int thoff = iph->ihl * 4;
+
+	if (flow->flags & FLOW_OFFLOAD_SNAT &&
+	    (nf_flow_snat_port(flow, skb, thoff, iph->protocol, dir) < 0 ||
+	     nf_flow_snat_ip(flow, skb, iph, thoff, dir) < 0))
+		return -1;
+	if (flow->flags & FLOW_OFFLOAD_DNAT &&
+	    (nf_flow_dnat_port(flow, skb, thoff, iph->protocol, dir) < 0 ||
+	     nf_flow_dnat_ip(flow, skb, iph, thoff, dir) < 0))
+		return -1;
+
+	return 0;
+}
+
+static bool ip_has_options(unsigned int thoff)
+{
+	return thoff != sizeof(struct iphdr);
+}
+
+static int nf_flow_tuple_ip(struct sk_buff *skb, const struct net_device *dev,
+			    struct flow_offload_tuple *tuple)
+{
+	struct flow_ports *ports;
+	unsigned int thoff;
+	struct iphdr *iph;
+
+	if (!pskb_may_pull(skb, sizeof(*iph)))
+		return -1;
+
+	iph = ip_hdr(skb);
+	thoff = iph->ihl * 4;
+
+	if (ip_is_fragment(iph) ||
+	    unlikely(ip_has_options(thoff)))
+		return -1;
+
+	if (iph->protocol != IPPROTO_TCP &&
+	    iph->protocol != IPPROTO_UDP)
+		return -1;
+
+	thoff = iph->ihl * 4;
+	if (!pskb_may_pull(skb, thoff + sizeof(*ports)))
+		return -1;
+
+	ports = (struct flow_ports *)(skb_network_header(skb) + thoff);
+
+	tuple->src_v4.s_addr	= iph->saddr;
+	tuple->dst_v4.s_addr	= iph->daddr;
+	tuple->src_port		= ports->source;
+	tuple->dst_port		= ports->dest;
+	tuple->l3proto		= AF_INET;
+	tuple->l4proto		= iph->protocol;
+	tuple->iifidx		= dev->ifindex;
+
+	return 0;
+}
+
+/* Based on ip_exceeds_mtu(). */
+static bool __nf_flow_exceeds_mtu(const struct sk_buff *skb, unsigned int mtu)
+{
+	if (skb->len <= mtu)
+		return false;
+
+	if ((ip_hdr(skb)->frag_off & htons(IP_DF)) == 0)
+		return false;
+
+	if (skb_is_gso(skb) && skb_gso_validate_mtu(skb, mtu))
+		return false;
+
+	return true;
+}
+
+static bool nf_flow_exceeds_mtu(struct sk_buff *skb, const struct rtable *rt)
+{
+	u32 mtu;
+
+	mtu = ip_dst_mtu_maybe_forward(&rt->dst, true);
+	if (__nf_flow_exceeds_mtu(skb, mtu))
+		return true;
+
+	return false;
+}
+
+unsigned int
+nf_flow_offload_ip_hook(void *priv, struct sk_buff *skb,
+			const struct nf_hook_state *state)
+{
+	struct flow_offload_tuple_rhash *tuplehash;
+	struct nf_flowtable *flow_table = priv;
+	struct flow_offload_tuple tuple = {};
+	enum flow_offload_tuple_dir dir;
+	struct flow_offload *flow;
+	struct net_device *outdev;
+	const struct rtable *rt;
+	struct iphdr *iph;
+	__be32 nexthop;
+
+	if (skb->protocol != htons(ETH_P_IP))
+		return NF_ACCEPT;
+
+	if (nf_flow_tuple_ip(skb, state->in, &tuple) < 0)
+		return NF_ACCEPT;
+
+	tuplehash = flow_offload_lookup(flow_table, &tuple);
+	if (tuplehash == NULL)
+		return NF_ACCEPT;
+
+	outdev = dev_get_by_index_rcu(state->net, tuplehash->tuple.oifidx);
+	if (!outdev)
+		return NF_ACCEPT;
+
+	dir = tuplehash->tuple.dir;
+	flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]);
+
+	rt = (const struct rtable *)flow->tuplehash[dir].tuple.dst_cache;
+	if (unlikely(nf_flow_exceeds_mtu(skb, rt)))
+		return NF_ACCEPT;
+
+	if (skb_try_make_writable(skb, sizeof(*iph)))
+		return NF_DROP;
+
+	if (flow->flags & (FLOW_OFFLOAD_SNAT | FLOW_OFFLOAD_DNAT) &&
+	    nf_flow_nat_ip(flow, skb, dir) < 0)
+		return NF_DROP;
+
+	flow->timeout = (u32)jiffies + NF_FLOW_TIMEOUT;
+	iph = ip_hdr(skb);
+	ip_decrease_ttl(iph);
+
+	skb->dev = outdev;
+	nexthop = rt_nexthop(rt, flow->tuplehash[!dir].tuple.src_v4.s_addr);
+	neigh_xmit(NEIGH_ARP_TABLE, outdev, &nexthop, skb);
+
+	return NF_STOLEN;
+}
+EXPORT_SYMBOL_GPL(nf_flow_offload_ip_hook);
+
+static struct nf_flowtable_type flowtable_ipv4 = {
+	.family		= NFPROTO_IPV4,
+	.params		= &nf_flow_offload_rhash_params,
+	.gc		= nf_flow_offload_work_gc,
+	.hook		= nf_flow_offload_ip_hook,
+	.owner		= THIS_MODULE,
+};
+
+static int __init nf_flow_ipv4_module_init(void)
+{
+	nft_register_flowtable_type(&flowtable_ipv4);
+
+	return 0;
+}
+
+static void __exit nf_flow_ipv4_module_exit(void)
+{
+	nft_unregister_flowtable_type(&flowtable_ipv4);
+}
+
+module_init(nf_flow_ipv4_module_init);
+module_exit(nf_flow_ipv4_module_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
+MODULE_ALIAS_NF_FLOWTABLE(AF_INET);
diff --git a/net/ipv4/netfilter/nf_nat_l3proto_ipv4.c b/net/ipv4/netfilter/nf_nat_l3proto_ipv4.c
index 0443ca4120b0..f7ff6a364d7b 100644
--- a/net/ipv4/netfilter/nf_nat_l3proto_ipv4.c
+++ b/net/ipv4/netfilter/nf_nat_l3proto_ipv4.c
@@ -356,11 +356,6 @@ nf_nat_ipv4_out(void *priv, struct sk_buff *skb,
 #endif
 	unsigned int ret;
 
-	/* root is playing with raw sockets. */
-	if (skb->len < sizeof(struct iphdr) ||
-	    ip_hdrlen(skb) < sizeof(struct iphdr))
-		return NF_ACCEPT;
-
 	ret = nf_nat_ipv4_fn(priv, skb, state, do_chain);
 #ifdef CONFIG_XFRM
 	if (ret != NF_DROP && ret != NF_STOLEN &&
@@ -396,11 +391,6 @@ nf_nat_ipv4_local_fn(void *priv, struct sk_buff *skb,
 	unsigned int ret;
 	int err;
 
-	/* root is playing with raw sockets. */
-	if (skb->len < sizeof(struct iphdr) ||
-	    ip_hdrlen(skb) < sizeof(struct iphdr))
-		return NF_ACCEPT;
-
 	ret = nf_nat_ipv4_fn(priv, skb, state, do_chain);
 	if (ret != NF_DROP && ret != NF_STOLEN &&
 	    (ct = nf_ct_get(skb, &ctinfo)) != NULL) {
diff --git a/net/ipv4/netfilter/nf_tables_arp.c b/net/ipv4/netfilter/nf_tables_arp.c
index 4bbc273b45e8..f84c17763f6f 100644
--- a/net/ipv4/netfilter/nf_tables_arp.c
+++ b/net/ipv4/netfilter/nf_tables_arp.c
@@ -21,7 +21,8 @@ nft_do_chain_arp(void *priv,
 {
 	struct nft_pktinfo pkt;
 
-	nft_set_pktinfo_unspec(&pkt, skb, state);
+	nft_set_pktinfo(&pkt, skb, state);
+	nft_set_pktinfo_unspec(&pkt, skb);
 
 	return nft_do_chain(&pkt, priv);
 }
@@ -30,12 +31,6 @@ static struct nft_af_info nft_af_arp __read_mostly = {
 	.family		= NFPROTO_ARP,
 	.nhooks		= NF_ARP_NUMHOOKS,
 	.owner		= THIS_MODULE,
-	.nops		= 1,
-	.hooks		= {
-		[NF_ARP_IN]		= nft_do_chain_arp,
-		[NF_ARP_OUT]		= nft_do_chain_arp,
-		[NF_ARP_FORWARD]	= nft_do_chain_arp,
-	},
 };
 
 static int nf_tables_arp_init_net(struct net *net)
@@ -73,6 +68,10 @@ static const struct nf_chain_type filter_arp = {
 	.owner		= THIS_MODULE,
 	.hook_mask	= (1 << NF_ARP_IN) |
 			  (1 << NF_ARP_OUT),
+	.hooks		= {
+		[NF_ARP_IN]		= nft_do_chain_arp,
+		[NF_ARP_OUT]		= nft_do_chain_arp,
+	},
 };
 
 static int __init nf_tables_arp_init(void)
diff --git a/net/ipv4/netfilter/nf_tables_ipv4.c b/net/ipv4/netfilter/nf_tables_ipv4.c
index 2840a29b2e04..f4675253f1e6 100644
--- a/net/ipv4/netfilter/nf_tables_ipv4.c
+++ b/net/ipv4/netfilter/nf_tables_ipv4.c
@@ -24,40 +24,17 @@ static unsigned int nft_do_chain_ipv4(void *priv,
 {
 	struct nft_pktinfo pkt;
 
-	nft_set_pktinfo_ipv4(&pkt, skb, state);
+	nft_set_pktinfo(&pkt, skb, state);
+	nft_set_pktinfo_ipv4(&pkt, skb);
 
 	return nft_do_chain(&pkt, priv);
 }
 
-static unsigned int nft_ipv4_output(void *priv,
-				    struct sk_buff *skb,
-				    const struct nf_hook_state *state)
-{
-	if (unlikely(skb->len < sizeof(struct iphdr) ||
-		     ip_hdr(skb)->ihl < sizeof(struct iphdr) / 4)) {
-		if (net_ratelimit())
-			pr_info("nf_tables_ipv4: ignoring short SOCK_RAW "
-				"packet\n");
-		return NF_ACCEPT;
-	}
-
-	return nft_do_chain_ipv4(priv, skb, state);
-}
-
-struct nft_af_info nft_af_ipv4 __read_mostly = {
+static struct nft_af_info nft_af_ipv4 __read_mostly = {
 	.family		= NFPROTO_IPV4,
 	.nhooks		= NF_INET_NUMHOOKS,
 	.owner		= THIS_MODULE,
-	.nops		= 1,
-	.hooks		= {
-		[NF_INET_LOCAL_IN]	= nft_do_chain_ipv4,
-		[NF_INET_LOCAL_OUT]	= nft_ipv4_output,
-		[NF_INET_FORWARD]	= nft_do_chain_ipv4,
-		[NF_INET_PRE_ROUTING]	= nft_do_chain_ipv4,
-		[NF_INET_POST_ROUTING]	= nft_do_chain_ipv4,
-	},
 };
-EXPORT_SYMBOL_GPL(nft_af_ipv4);
 
 static int nf_tables_ipv4_init_net(struct net *net)
 {
@@ -97,6 +74,13 @@ static const struct nf_chain_type filter_ipv4 = {
 			  (1 << NF_INET_FORWARD) |
 			  (1 << NF_INET_PRE_ROUTING) |
 			  (1 << NF_INET_POST_ROUTING),
+	.hooks		= {
+		[NF_INET_LOCAL_IN]	= nft_do_chain_ipv4,
+		[NF_INET_LOCAL_OUT]	= nft_do_chain_ipv4,
+		[NF_INET_FORWARD]	= nft_do_chain_ipv4,
+		[NF_INET_PRE_ROUTING]	= nft_do_chain_ipv4,
+		[NF_INET_POST_ROUTING]	= nft_do_chain_ipv4,
+	},
 };
 
 static int __init nf_tables_ipv4_init(void)
diff --git a/net/ipv4/netfilter/nft_chain_nat_ipv4.c b/net/ipv4/netfilter/nft_chain_nat_ipv4.c
index f5c66a7a4bf2..f2a490981594 100644
--- a/net/ipv4/netfilter/nft_chain_nat_ipv4.c
+++ b/net/ipv4/netfilter/nft_chain_nat_ipv4.c
@@ -33,7 +33,8 @@ static unsigned int nft_nat_do_chain(void *priv,
 {
 	struct nft_pktinfo pkt;
 
-	nft_set_pktinfo_ipv4(&pkt, skb, state);
+	nft_set_pktinfo(&pkt, skb, state);
+	nft_set_pktinfo_ipv4(&pkt, skb);
 
 	return nft_do_chain(&pkt, priv);
 }
diff --git a/net/ipv4/netfilter/nft_chain_route_ipv4.c b/net/ipv4/netfilter/nft_chain_route_ipv4.c
index 30493beb611a..d965c225b9f6 100644
--- a/net/ipv4/netfilter/nft_chain_route_ipv4.c
+++ b/net/ipv4/netfilter/nft_chain_route_ipv4.c
@@ -33,12 +33,8 @@ static unsigned int nf_route_table_hook(void *priv,
 	const struct iphdr *iph;
 	int err;
 
-	/* root is playing with raw sockets. */
-	if (skb->len < sizeof(struct iphdr) ||
-	    ip_hdrlen(skb) < sizeof(struct iphdr))
-		return NF_ACCEPT;
-
-	nft_set_pktinfo_ipv4(&pkt, skb, state);
+	nft_set_pktinfo(&pkt, skb, state);
+	nft_set_pktinfo_ipv4(&pkt, skb);
 
 	mark = skb->mark;
 	iph = ip_hdr(skb);