kernel: mark source kernel for netfilter backports

This helps keeping track on patches & adding new kernels in the future.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>

1 files changed, 354 insertions, 0 deletions

diff --git a/target/linux/generic/backport-4.14/324-v4.16-netfilter-flow-table-support-for-IPv6.patch b/target/linux/generic/backport-4.14/324-v4.16-netfilter-flow-table-support-for-IPv6.patch
new file mode 100644
index 0000000000..abe7ef0092
--- /dev/null
+++ b/target/linux/generic/backport-4.14/324-v4.16-netfilter-flow-table-support-for-IPv6.patch
@@ -0,0 +1,354 @@
+From: Pablo Neira Ayuso <pablo@netfilter.org>
+Date: Sun, 7 Jan 2018 01:04:19 +0100
+Subject: [PATCH] netfilter: flow table support for IPv6
+
+This patch adds the IPv6 flow table type, that implements the datapath
+flow table to forward IPv6 traffic.
+
+This patch exports ip6_dst_mtu_forward() that is required to check for
+mtu to pass up packets that need PMTUD handling to the classic
+forwarding path.
+
+Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
+---
+ create mode 100644 net/ipv6/netfilter/nf_flow_table_ipv6.c
+
+--- a/include/net/ipv6.h
++++ b/include/net/ipv6.h
+@@ -913,6 +913,8 @@ static inline struct sk_buff *ip6_finish
+ 			      &inet6_sk(sk)->cork);
+ }
+ 
++unsigned int ip6_dst_mtu_forward(const struct dst_entry *dst);
++
+ int ip6_dst_lookup(struct net *net, struct sock *sk, struct dst_entry **dst,
+ 		   struct flowi6 *fl6);
+ struct dst_entry *ip6_dst_lookup_flow(const struct sock *sk, struct flowi6 *fl6,
+--- a/net/ipv6/ip6_output.c
++++ b/net/ipv6/ip6_output.c
+@@ -383,7 +383,7 @@ static inline int ip6_forward_finish(str
+ 	return dst_output(net, sk, skb);
+ }
+ 
+-static unsigned int ip6_dst_mtu_forward(const struct dst_entry *dst)
++unsigned int ip6_dst_mtu_forward(const struct dst_entry *dst)
+ {
+ 	unsigned int mtu;
+ 	struct inet6_dev *idev;
+@@ -403,6 +403,7 @@ static unsigned int ip6_dst_mtu_forward(
+ 
+ 	return mtu;
+ }
++EXPORT_SYMBOL_GPL(ip6_dst_mtu_forward);
+ 
+ static bool ip6_pkt_too_big(const struct sk_buff *skb, unsigned int mtu)
+ {
+--- a/net/ipv6/netfilter/Kconfig
++++ b/net/ipv6/netfilter/Kconfig
+@@ -71,6 +71,14 @@ config NFT_FIB_IPV6
+ endif # NF_TABLES_IPV6
+ endif # NF_TABLES
+ 
++config NF_FLOW_TABLE_IPV6
++	select NF_FLOW_TABLE
++	tristate "Netfilter flow table IPv6 module"
++	help
++	  This option adds the flow table IPv6 support.
++
++	  To compile it as a module, choose M here.
++
+ config NF_DUP_IPV6
+ 	tristate "Netfilter IPv6 packet duplication to alternate destination"
+ 	depends on !NF_CONNTRACK || NF_CONNTRACK
+--- a/net/ipv6/netfilter/Makefile
++++ b/net/ipv6/netfilter/Makefile
+@@ -45,6 +45,9 @@ obj-$(CONFIG_NFT_REDIR_IPV6) += nft_redi
+ obj-$(CONFIG_NFT_DUP_IPV6) += nft_dup_ipv6.o
+ obj-$(CONFIG_NFT_FIB_IPV6) += nft_fib_ipv6.o
+ 
++# flow table support
++obj-$(CONFIG_NF_FLOW_TABLE_IPV6) += nf_flow_table_ipv6.o
++
+ # matches
+ obj-$(CONFIG_IP6_NF_MATCH_AH) += ip6t_ah.o
+ obj-$(CONFIG_IP6_NF_MATCH_EUI64) += ip6t_eui64.o
+--- /dev/null
++++ b/net/ipv6/netfilter/nf_flow_table_ipv6.c
+@@ -0,0 +1,277 @@
++#include <linux/kernel.h>
++#include <linux/init.h>
++#include <linux/module.h>
++#include <linux/netfilter.h>
++#include <linux/rhashtable.h>
++#include <linux/ipv6.h>
++#include <linux/netdevice.h>
++#include <linux/ipv6.h>
++#include <net/ipv6.h>
++#include <net/ip6_route.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_ipv6_tcp(struct sk_buff *skb, unsigned int thoff,
++				struct in6_addr *addr,
++				struct in6_addr *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_replace16(&tcph->check, skb, addr->s6_addr32,
++				  new_addr->s6_addr32, true);
++
++	return 0;
++}
++
++static int nf_flow_nat_ipv6_udp(struct sk_buff *skb, unsigned int thoff,
++				struct in6_addr *addr,
++				struct in6_addr *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_replace16(&udph->check, skb, addr->s6_addr32,
++					  new_addr->s6_addr32, true);
++		if (!udph->check)
++			udph->check = CSUM_MANGLED_0;
++	}
++
++	return 0;
++}
++
++static int nf_flow_nat_ipv6_l4proto(struct sk_buff *skb, struct ipv6hdr *ip6h,
++				    unsigned int thoff, struct in6_addr *addr,
++				    struct in6_addr *new_addr)
++{
++	switch (ip6h->nexthdr) {
++	case IPPROTO_TCP:
++		if (nf_flow_nat_ipv6_tcp(skb, thoff, addr, new_addr) < 0)
++			return NF_DROP;
++		break;
++	case IPPROTO_UDP:
++		if (nf_flow_nat_ipv6_udp(skb, thoff, addr, new_addr) < 0)
++			return NF_DROP;
++		break;
++	}
++
++	return 0;
++}
++
++static int nf_flow_snat_ipv6(const struct flow_offload *flow,
++			     struct sk_buff *skb, struct ipv6hdr *ip6h,
++			     unsigned int thoff,
++			     enum flow_offload_tuple_dir dir)
++{
++	struct in6_addr addr, new_addr;
++
++	switch (dir) {
++	case FLOW_OFFLOAD_DIR_ORIGINAL:
++		addr = ip6h->saddr;
++		new_addr = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.dst_v6;
++		ip6h->saddr = new_addr;
++		break;
++	case FLOW_OFFLOAD_DIR_REPLY:
++		addr = ip6h->daddr;
++		new_addr = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.src_v6;
++		ip6h->daddr = new_addr;
++		break;
++	default:
++		return -1;
++	}
++
++	return nf_flow_nat_ipv6_l4proto(skb, ip6h, thoff, &addr, &new_addr);
++}
++
++static int nf_flow_dnat_ipv6(const struct flow_offload *flow,
++			     struct sk_buff *skb, struct ipv6hdr *ip6h,
++			     unsigned int thoff,
++			     enum flow_offload_tuple_dir dir)
++{
++	struct in6_addr addr, new_addr;
++
++	switch (dir) {
++	case FLOW_OFFLOAD_DIR_ORIGINAL:
++		addr = ip6h->daddr;
++		new_addr = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.src_v6;
++		ip6h->daddr = new_addr;
++		break;
++	case FLOW_OFFLOAD_DIR_REPLY:
++		addr = ip6h->saddr;
++		new_addr = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.dst_v6;
++		ip6h->saddr = new_addr;
++		break;
++	default:
++		return -1;
++	}
++
++	return nf_flow_nat_ipv6_l4proto(skb, ip6h, thoff, &addr, &new_addr);
++}
++
++static int nf_flow_nat_ipv6(const struct flow_offload *flow,
++			    struct sk_buff *skb,
++			    enum flow_offload_tuple_dir dir)
++{
++	struct ipv6hdr *ip6h = ipv6_hdr(skb);
++	unsigned int thoff = sizeof(*ip6h);
++
++	if (flow->flags & FLOW_OFFLOAD_SNAT &&
++	    (nf_flow_snat_port(flow, skb, thoff, ip6h->nexthdr, dir) < 0 ||
++	     nf_flow_snat_ipv6(flow, skb, ip6h, thoff, dir) < 0))
++		return -1;
++	if (flow->flags & FLOW_OFFLOAD_DNAT &&
++	    (nf_flow_dnat_port(flow, skb, thoff, ip6h->nexthdr, dir) < 0 ||
++	     nf_flow_dnat_ipv6(flow, skb, ip6h, thoff, dir) < 0))
++		return -1;
++
++	return 0;
++}
++
++static int nf_flow_tuple_ipv6(struct sk_buff *skb, const struct net_device *dev,
++			      struct flow_offload_tuple *tuple)
++{
++	struct flow_ports *ports;
++	struct ipv6hdr *ip6h;
++	unsigned int thoff;
++
++	if (!pskb_may_pull(skb, sizeof(*ip6h)))
++		return -1;
++
++	ip6h = ipv6_hdr(skb);
++
++	if (ip6h->nexthdr != IPPROTO_TCP &&
++	    ip6h->nexthdr != IPPROTO_UDP)
++		return -1;
++
++	thoff = sizeof(*ip6h);
++	if (!pskb_may_pull(skb, thoff + sizeof(*ports)))
++		return -1;
++
++	ports = (struct flow_ports *)(skb_network_header(skb) + thoff);
++
++	tuple->src_v6		= ip6h->saddr;
++	tuple->dst_v6		= ip6h->daddr;
++	tuple->src_port		= ports->source;
++	tuple->dst_port		= ports->dest;
++	tuple->l3proto		= AF_INET6;
++	tuple->l4proto		= ip6h->nexthdr;
++	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 (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 rt6_info *rt)
++{
++	u32 mtu;
++
++	mtu = ip6_dst_mtu_forward(&rt->dst);
++	if (__nf_flow_exceeds_mtu(skb, mtu))
++		return true;
++
++	return false;
++}
++
++static unsigned int
++nf_flow_offload_ipv6_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;
++	struct in6_addr *nexthop;
++	struct ipv6hdr *ip6h;
++	struct rt6_info *rt;
++
++	if (skb->protocol != htons(ETH_P_IPV6))
++		return NF_ACCEPT;
++
++	if (nf_flow_tuple_ipv6(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 = (struct rt6_info *)flow->tuplehash[dir].tuple.dst_cache;
++	if (unlikely(nf_flow_exceeds_mtu(skb, rt)))
++		return NF_ACCEPT;
++
++	if (skb_try_make_writable(skb, sizeof(*ip6h)))
++		return NF_DROP;
++
++	if (flow->flags & (FLOW_OFFLOAD_SNAT | FLOW_OFFLOAD_DNAT) &&
++	    nf_flow_nat_ipv6(flow, skb, dir) < 0)
++		return NF_DROP;
++
++	flow->timeout = (u32)jiffies + NF_FLOW_TIMEOUT;
++	ip6h = ipv6_hdr(skb);
++	ip6h->hop_limit--;
++
++	skb->dev = outdev;
++	nexthop = rt6_nexthop(rt, &flow->tuplehash[!dir].tuple.src_v6);
++	neigh_xmit(NEIGH_ND_TABLE, outdev, nexthop, skb);
++
++	return NF_STOLEN;
++}
++
++static struct nf_flowtable_type flowtable_ipv6 = {
++	.family		= NFPROTO_IPV6,
++	.params		= &nf_flow_offload_rhash_params,
++	.gc		= nf_flow_offload_work_gc,
++	.hook		= nf_flow_offload_ipv6_hook,
++	.owner		= THIS_MODULE,
++};
++
++static int __init nf_flow_ipv6_module_init(void)
++{
++	nft_register_flowtable_type(&flowtable_ipv6);
++
++	return 0;
++}
++
++static void __exit nf_flow_ipv6_module_exit(void)
++{
++	nft_unregister_flowtable_type(&flowtable_ipv6);
++}
++
++module_init(nf_flow_ipv6_module_init);
++module_exit(nf_flow_ipv6_module_exit);
++
++MODULE_LICENSE("GPL");
++MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
++MODULE_ALIAS_NF_FLOWTABLE(AF_INET6);