kernel: backport netfilter NAT offload support to 4.14

This only works with nftables for now, iptables support will be added
later. Includes a number of related upstream nftables improvements to
simplify backporting follow-up changes

Signed-off-by: John Crispin <john@phrozen.org>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

1 files changed, 298 insertions, 0 deletions

diff --git a/target/linux/generic/backport-4.14/357-netfilter-nf_flow_table-move-init-code-to-nf_flow_ta.patch b/target/linux/generic/backport-4.14/357-netfilter-nf_flow_table-move-init-code-to-nf_flow_ta.patch
new file mode 100644
index 0000000000..75cbda6baf
--- /dev/null
+++ b/target/linux/generic/backport-4.14/357-netfilter-nf_flow_table-move-init-code-to-nf_flow_ta.patch
@@ -0,0 +1,298 @@
+From: Felix Fietkau <nbd@nbd.name>
+Date: Sun, 18 Feb 2018 18:16:31 +0100
+Subject: [PATCH] netfilter: nf_flow_table: move init code to
+ nf_flow_table_core.c
+
+Reduces duplication of .gc and .params in flowtable type definitions and
+makes the API clearer
+
+Signed-off-by: Felix Fietkau <nbd@nbd.name>
+---
+
+--- a/include/net/netfilter/nf_flow_table.h
++++ b/include/net/netfilter/nf_flow_table.h
+@@ -14,9 +14,8 @@ struct nf_flowtable;
+ struct nf_flowtable_type {
+ 	struct list_head		list;
+ 	int				family;
+-	void				(*gc)(struct work_struct *work);
++	int				(*init)(struct nf_flowtable *ft);
+ 	void				(*free)(struct nf_flowtable *ft);
+-	const struct rhashtable_params	*params;
+ 	nf_hookfn			*hook;
+ 	struct module			*owner;
+ };
+@@ -100,9 +99,8 @@ int nf_flow_table_iterate(struct nf_flow
+ 
+ void nf_flow_table_cleanup(struct net *net, struct net_device *dev);
+ 
++int nf_flow_table_init(struct nf_flowtable *flow_table);
+ void nf_flow_table_free(struct nf_flowtable *flow_table);
+-void nf_flow_offload_work_gc(struct work_struct *work);
+-extern const struct rhashtable_params nf_flow_offload_rhash_params;
+ 
+ void flow_offload_dead(struct flow_offload *flow);
+ 
+--- a/net/ipv4/netfilter/nf_flow_table_ipv4.c
++++ b/net/ipv4/netfilter/nf_flow_table_ipv4.c
+@@ -7,8 +7,7 @@
+ 
+ static struct nf_flowtable_type flowtable_ipv4 = {
+ 	.family		= NFPROTO_IPV4,
+-	.params		= &nf_flow_offload_rhash_params,
+-	.gc		= nf_flow_offload_work_gc,
++	.init		= nf_flow_table_init,
+ 	.free		= nf_flow_table_free,
+ 	.hook		= nf_flow_offload_ip_hook,
+ 	.owner		= THIS_MODULE,
+--- a/net/ipv6/netfilter/nf_flow_table_ipv6.c
++++ b/net/ipv6/netfilter/nf_flow_table_ipv6.c
+@@ -8,8 +8,7 @@
+ 
+ static struct nf_flowtable_type flowtable_ipv6 = {
+ 	.family		= NFPROTO_IPV6,
+-	.params		= &nf_flow_offload_rhash_params,
+-	.gc		= nf_flow_offload_work_gc,
++	.init		= nf_flow_table_init,
+ 	.free		= nf_flow_table_free,
+ 	.hook		= nf_flow_offload_ipv6_hook,
+ 	.owner		= THIS_MODULE,
+--- a/net/netfilter/nf_flow_table_core.c
++++ b/net/netfilter/nf_flow_table_core.c
+@@ -116,16 +116,50 @@ void flow_offload_dead(struct flow_offlo
+ }
+ EXPORT_SYMBOL_GPL(flow_offload_dead);
+ 
++static u32 flow_offload_hash(const void *data, u32 len, u32 seed)
++{
++	const struct flow_offload_tuple *tuple = data;
++
++	return jhash(tuple, offsetof(struct flow_offload_tuple, dir), seed);
++}
++
++static u32 flow_offload_hash_obj(const void *data, u32 len, u32 seed)
++{
++	const struct flow_offload_tuple_rhash *tuplehash = data;
++
++	return jhash(&tuplehash->tuple, offsetof(struct flow_offload_tuple, dir), seed);
++}
++
++static int flow_offload_hash_cmp(struct rhashtable_compare_arg *arg,
++					const void *ptr)
++{
++	const struct flow_offload_tuple *tuple = arg->key;
++	const struct flow_offload_tuple_rhash *x = ptr;
++
++	if (memcmp(&x->tuple, tuple, offsetof(struct flow_offload_tuple, dir)))
++		return 1;
++
++	return 0;
++}
++
++static const struct rhashtable_params nf_flow_offload_rhash_params = {
++	.head_offset		= offsetof(struct flow_offload_tuple_rhash, node),
++	.hashfn			= flow_offload_hash,
++	.obj_hashfn		= flow_offload_hash_obj,
++	.obj_cmpfn		= flow_offload_hash_cmp,
++	.automatic_shrinking	= true,
++};
++
+ int flow_offload_add(struct nf_flowtable *flow_table, struct flow_offload *flow)
+ {
+ 	flow->timeout = (u32)jiffies;
+ 
+ 	rhashtable_insert_fast(&flow_table->rhashtable,
+ 			       &flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].node,
+-			       *flow_table->type->params);
++			       nf_flow_offload_rhash_params);
+ 	rhashtable_insert_fast(&flow_table->rhashtable,
+ 			       &flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].node,
+-			       *flow_table->type->params);
++			       nf_flow_offload_rhash_params);
+ 	return 0;
+ }
+ EXPORT_SYMBOL_GPL(flow_offload_add);
+@@ -135,10 +169,10 @@ static void flow_offload_del(struct nf_f
+ {
+ 	rhashtable_remove_fast(&flow_table->rhashtable,
+ 			       &flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].node,
+-			       *flow_table->type->params);
++			       nf_flow_offload_rhash_params);
+ 	rhashtable_remove_fast(&flow_table->rhashtable,
+ 			       &flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].node,
+-			       *flow_table->type->params);
++			       nf_flow_offload_rhash_params);
+ 
+ 	flow_offload_free(flow);
+ }
+@@ -148,7 +182,7 @@ flow_offload_lookup(struct nf_flowtable
+ 		    struct flow_offload_tuple *tuple)
+ {
+ 	return rhashtable_lookup_fast(&flow_table->rhashtable, tuple,
+-				      *flow_table->type->params);
++				      nf_flow_offload_rhash_params);
+ }
+ EXPORT_SYMBOL_GPL(flow_offload_lookup);
+ 
+@@ -237,7 +271,7 @@ out:
+ 	return 1;
+ }
+ 
+-void nf_flow_offload_work_gc(struct work_struct *work)
++static void nf_flow_offload_work_gc(struct work_struct *work)
+ {
+ 	struct nf_flowtable *flow_table;
+ 
+@@ -245,42 +279,6 @@ void nf_flow_offload_work_gc(struct work
+ 	nf_flow_offload_gc_step(flow_table);
+ 	queue_delayed_work(system_power_efficient_wq, &flow_table->gc_work, HZ);
+ }
+-EXPORT_SYMBOL_GPL(nf_flow_offload_work_gc);
+-
+-static u32 flow_offload_hash(const void *data, u32 len, u32 seed)
+-{
+-	const struct flow_offload_tuple *tuple = data;
+-
+-	return jhash(tuple, offsetof(struct flow_offload_tuple, dir), seed);
+-}
+-
+-static u32 flow_offload_hash_obj(const void *data, u32 len, u32 seed)
+-{
+-	const struct flow_offload_tuple_rhash *tuplehash = data;
+-
+-	return jhash(&tuplehash->tuple, offsetof(struct flow_offload_tuple, dir), seed);
+-}
+-
+-static int flow_offload_hash_cmp(struct rhashtable_compare_arg *arg,
+-					const void *ptr)
+-{
+-	const struct flow_offload_tuple *tuple = arg->key;
+-	const struct flow_offload_tuple_rhash *x = ptr;
+-
+-	if (memcmp(&x->tuple, tuple, offsetof(struct flow_offload_tuple, dir)))
+-		return 1;
+-
+-	return 0;
+-}
+-
+-const struct rhashtable_params nf_flow_offload_rhash_params = {
+-	.head_offset		= offsetof(struct flow_offload_tuple_rhash, node),
+-	.hashfn			= flow_offload_hash,
+-	.obj_hashfn		= flow_offload_hash_obj,
+-	.obj_cmpfn		= flow_offload_hash_cmp,
+-	.automatic_shrinking	= true,
+-};
+-EXPORT_SYMBOL_GPL(nf_flow_offload_rhash_params);
+ 
+ static int nf_flow_nat_port_tcp(struct sk_buff *skb, unsigned int thoff,
+ 				__be16 port, __be16 new_port)
+@@ -398,6 +396,24 @@ int nf_flow_dnat_port(const struct flow_
+ }
+ EXPORT_SYMBOL_GPL(nf_flow_dnat_port);
+ 
++int nf_flow_table_init(struct nf_flowtable *flowtable)
++{
++	int err;
++
++	INIT_DEFERRABLE_WORK(&flowtable->gc_work, nf_flow_offload_work_gc);
++
++	err = rhashtable_init(&flowtable->rhashtable,
++			      &nf_flow_offload_rhash_params);
++	if (err < 0)
++		return err;
++
++	queue_delayed_work(system_power_efficient_wq,
++			   &flowtable->gc_work, HZ);
++
++	return 0;
++}
++EXPORT_SYMBOL_GPL(nf_flow_table_init);
++
+ static void nf_flow_table_do_cleanup(struct flow_offload *flow, void *data)
+ {
+ 	struct net_device *dev = data;
+@@ -423,8 +439,10 @@ EXPORT_SYMBOL_GPL(nf_flow_table_cleanup)
+ 
+ void nf_flow_table_free(struct nf_flowtable *flow_table)
+ {
++	cancel_delayed_work_sync(&flow_table->gc_work);
+ 	nf_flow_table_iterate(flow_table, nf_flow_table_do_cleanup, NULL);
+ 	WARN_ON(!nf_flow_offload_gc_step(flow_table));
++	rhashtable_destroy(&flow_table->rhashtable);
+ }
+ EXPORT_SYMBOL_GPL(nf_flow_table_free);
+ 
+--- a/net/netfilter/nf_flow_table_inet.c
++++ b/net/netfilter/nf_flow_table_inet.c
+@@ -22,8 +22,7 @@ nf_flow_offload_inet_hook(void *priv, st
+ 
+ static struct nf_flowtable_type flowtable_inet = {
+ 	.family		= NFPROTO_INET,
+-	.params		= &nf_flow_offload_rhash_params,
+-	.gc		= nf_flow_offload_work_gc,
++	.init		= nf_flow_table_init,
+ 	.free		= nf_flow_table_free,
+ 	.hook		= nf_flow_offload_inet_hook,
+ 	.owner		= THIS_MODULE,
+--- a/net/netfilter/nf_tables_api.c
++++ b/net/netfilter/nf_tables_api.c
+@@ -5013,40 +5013,38 @@ static int nf_tables_newflowtable(struct
+ 	}
+ 
+ 	flowtable->data.type = type;
+-	err = rhashtable_init(&flowtable->data.rhashtable, type->params);
++	err = type->init(&flowtable->data);
+ 	if (err < 0)
+ 		goto err3;
+ 
+ 	err = nf_tables_flowtable_parse_hook(&ctx, nla[NFTA_FLOWTABLE_HOOK],
+ 					     flowtable);
+ 	if (err < 0)
+-		goto err3;
++		goto err4;
+ 
+ 	for (i = 0; i < flowtable->ops_len; i++) {
+ 		err = nf_register_net_hook(net, &flowtable->ops[i]);
+ 		if (err < 0)
+-			goto err4;
++			goto err5;
+ 	}
+ 
+ 	err = nft_trans_flowtable_add(&ctx, NFT_MSG_NEWFLOWTABLE, flowtable);
+ 	if (err < 0)
+-		goto err5;
+-
+-	INIT_DEFERRABLE_WORK(&flowtable->data.gc_work, type->gc);
+-	queue_delayed_work(system_power_efficient_wq,
+-			   &flowtable->data.gc_work, HZ);
++		goto err6;
+ 
+ 	list_add_tail_rcu(&flowtable->list, &table->flowtables);
+ 	table->use++;
+ 
+ 	return 0;
+-err5:
++err6:
+ 	i = flowtable->ops_len;
+-err4:
++err5:
+ 	for (k = i - 1; k >= 0; k--)
+ 		nf_unregister_net_hook(net, &flowtable->ops[i]);
+ 
+ 	kfree(flowtable->ops);
++err4:
++	flowtable->data.type->free(&flowtable->data);
+ err3:
+ 	module_put(type->owner);
+ err2:
+@@ -5325,10 +5323,8 @@ err:
+ 
+ static void nf_tables_flowtable_destroy(struct nft_flowtable *flowtable)
+ {
+-	cancel_delayed_work_sync(&flowtable->data.gc_work);
+ 	kfree(flowtable->name);
+ 	flowtable->data.type->free(&flowtable->data);
+-	rhashtable_destroy(&flowtable->data.rhashtable);
+ 	module_put(flowtable->data.type->owner);
+ }
+