Merge branch 'sched-introduce-chain-templates-support-with-offloading-to-mlxsw'

Jiri Pirko says:

====================
sched: introduce chain templates support with offloading to mlxsw

For the TC clsact offload these days, some of HW drivers need
to hold a magic ball. The reason is, with the first inserted rule inside
HW they need to guess what fields will be used for the matching. If
later on this guess proves to be wrong and user adds a filter with a
different field to match, there's a problem. Mlxsw resolves it now with
couple of patterns. Those try to cover as many match fields as possible.
This aproach is far from optimal, both performance-wise and scale-wise.
Also, there is a combination of filters that in certain order won't
succeed.

Most of the time, when user inserts filters in chain, he knows right away
how the filters are going to look like - what type and option will they
have. For example, he knows that he will only insert filters of type
flower matching destination IP address. He can specify a template that
would cover all the filters in the chain.

This patchset is providing the possibility to user to provide such
template to kernel and propagate it all the way down to device
drivers.

See the examples below.

Create dummy device with clsact first:

There is no chain present by by default:

Add chain number 11 by explicit command:
chain parent ffff: chain 11

Add filter to chain number 12 which does not exist. That will create
implicit chain 12:
chain parent ffff: chain 11
chain parent ffff: chain 12

Delete both chains:

Add a chain with template of type flower allowing to insert rules matching
on last 2 bytes of destination mac address:

The chain with template is now showed in the list:
chain parent ffff: flower chain 0
  dst_mac 00:00:00:00:00:00/00:00:00:00:ff:ff
  eth_type ipv4

Add another chain (number 22) with template:
chain parent ffff: flower chain 0
  dst_mac 00:00:00:00:00:00/00:00:00:00:ff:ff
  eth_type ipv4
chain parent ffff: flower chain 22
  eth_type ipv4
  dst_ip 0.0.0.0/16

Add a filter that fits the template:

Addition of filters that does not fit the template would fail:
Error: cls_flower: Mask does not fit the template.
We have an error talking to the kernel, -1
Error: cls_flower: Mask does not fit the template.
We have an error talking to the kernel, -1

Additions of filters to chain 22:
Error: cls_flower: Mask does not fit the template.
We have an error talking to the kernel, -1
Error: cls_flower: Mask does not fit the template.
We have an error talking to the kernel, -1

---
v3->v4:
- patch 2:
  - new patch
- patch 3:
  - new patch, derived from the previous v3 chaintemplate obj patch
- patch 4:
  - only templates part as chains creation/deletion is now a separate patch
  - don't pass template priv as arg of "change" op
- patch 6:
  - rebased on top of flower cvlan patch and ip tos/ttl patch
- patch 7:
  - templave priv is no longer passed as an arg to "change" op
- patch 11:
  - split from the originally single patch
- patch 12:
  - split from the originally single patch
v2->v3:
- patch 7:
  - rebase on top of the reoffload patchset
- patch 8:
  - rebase on top of the reoffload patchset
v1->v2:
- patch 8:
  - remove leftover extack arg in fl_hw_create_tmplt()
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

15 files changed, 829 insertions, 139 deletions

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
index 317c92d6496e..039228525fb1 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
@@ -1455,6 +1455,11 @@ mlxsw_sp_setup_tc_cls_flower(struct mlxsw_sp_acl_block *acl_block,
 		return 0;
 	case TC_CLSFLOWER_STATS:
 		return mlxsw_sp_flower_stats(mlxsw_sp, acl_block, f);
+	case TC_CLSFLOWER_TMPLT_CREATE:
+		return mlxsw_sp_flower_tmplt_create(mlxsw_sp, acl_block, f);
+	case TC_CLSFLOWER_TMPLT_DESTROY:
+		mlxsw_sp_flower_tmplt_destroy(mlxsw_sp, acl_block, f);
+		return 0;
 	default:
 		return -EOPNOTSUPP;
 	}
diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum.h b/drivers/net/ethernet/mellanox/mlxsw/spectrum.h
index 016058961542..3db386c2573f 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum.h
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum.h
@@ -543,7 +543,8 @@ mlxsw_sp_acl_ruleset_lookup(struct mlxsw_sp *mlxsw_sp,
 struct mlxsw_sp_acl_ruleset *
 mlxsw_sp_acl_ruleset_get(struct mlxsw_sp *mlxsw_sp,
 			 struct mlxsw_sp_acl_block *block, u32 chain_index,
-			 enum mlxsw_sp_acl_profile profile);
+			 enum mlxsw_sp_acl_profile profile,
+			 struct mlxsw_afk_element_usage *tmplt_elusage);
 void mlxsw_sp_acl_ruleset_put(struct mlxsw_sp *mlxsw_sp,
 			      struct mlxsw_sp_acl_ruleset *ruleset);
 u16 mlxsw_sp_acl_ruleset_group_id(struct mlxsw_sp_acl_ruleset *ruleset);
@@ -667,6 +668,12 @@ void mlxsw_sp_flower_destroy(struct mlxsw_sp *mlxsw_sp,
 int mlxsw_sp_flower_stats(struct mlxsw_sp *mlxsw_sp,
 			  struct mlxsw_sp_acl_block *block,
 			  struct tc_cls_flower_offload *f);
+int mlxsw_sp_flower_tmplt_create(struct mlxsw_sp *mlxsw_sp,
+				 struct mlxsw_sp_acl_block *block,
+				 struct tc_cls_flower_offload *f);
+void mlxsw_sp_flower_tmplt_destroy(struct mlxsw_sp *mlxsw_sp,
+				   struct mlxsw_sp_acl_block *block,
+				   struct tc_cls_flower_offload *f);
 
 /* spectrum_qdisc.c */
 int mlxsw_sp_tc_qdisc_init(struct mlxsw_sp_port *mlxsw_sp_port);
diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl.c
index 217621d79e26..4a4739139d11 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl.c
@@ -317,7 +317,8 @@ int mlxsw_sp_acl_block_unbind(struct mlxsw_sp *mlxsw_sp,
 static struct mlxsw_sp_acl_ruleset *
 mlxsw_sp_acl_ruleset_create(struct mlxsw_sp *mlxsw_sp,
 			    struct mlxsw_sp_acl_block *block, u32 chain_index,
-			    const struct mlxsw_sp_acl_profile_ops *ops)
+			    const struct mlxsw_sp_acl_profile_ops *ops,
+			    struct mlxsw_afk_element_usage *tmplt_elusage)
 {
 	struct mlxsw_sp_acl *acl = mlxsw_sp->acl;
 	struct mlxsw_sp_acl_ruleset *ruleset;
@@ -337,7 +338,8 @@ mlxsw_sp_acl_ruleset_create(struct mlxsw_sp *mlxsw_sp,
 	if (err)
 		goto err_rhashtable_init;
 
-	err = ops->ruleset_add(mlxsw_sp, &acl->tcam, ruleset->priv);
+	err = ops->ruleset_add(mlxsw_sp, &acl->tcam, ruleset->priv,
+			       tmplt_elusage);
 	if (err)
 		goto err_ops_ruleset_add;
 
@@ -419,7 +421,8 @@ mlxsw_sp_acl_ruleset_lookup(struct mlxsw_sp *mlxsw_sp,
 struct mlxsw_sp_acl_ruleset *
 mlxsw_sp_acl_ruleset_get(struct mlxsw_sp *mlxsw_sp,
 			 struct mlxsw_sp_acl_block *block, u32 chain_index,
-			 enum mlxsw_sp_acl_profile profile)
+			 enum mlxsw_sp_acl_profile profile,
+			 struct mlxsw_afk_element_usage *tmplt_elusage)
 {
 	const struct mlxsw_sp_acl_profile_ops *ops;
 	struct mlxsw_sp_acl *acl = mlxsw_sp->acl;
@@ -434,7 +437,8 @@ mlxsw_sp_acl_ruleset_get(struct mlxsw_sp *mlxsw_sp,
 		mlxsw_sp_acl_ruleset_ref_inc(ruleset);
 		return ruleset;
 	}
-	return mlxsw_sp_acl_ruleset_create(mlxsw_sp, block, chain_index, ops);
+	return mlxsw_sp_acl_ruleset_create(mlxsw_sp, block, chain_index, ops,
+					   tmplt_elusage);
 }
 
 void mlxsw_sp_acl_ruleset_put(struct mlxsw_sp *mlxsw_sp,
diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.c
index e06d7d9e5b7f..310fd87895b8 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.c
@@ -189,6 +189,8 @@ struct mlxsw_sp_acl_tcam_group {
 	struct mlxsw_sp_acl_tcam_group_ops *ops;
 	const struct mlxsw_sp_acl_tcam_pattern *patterns;
 	unsigned int patterns_count;
+	bool tmplt_elusage_set;
+	struct mlxsw_afk_element_usage tmplt_elusage;
 };
 
 struct mlxsw_sp_acl_tcam_chunk {
@@ -234,13 +236,19 @@ mlxsw_sp_acl_tcam_group_add(struct mlxsw_sp *mlxsw_sp,
 			    struct mlxsw_sp_acl_tcam *tcam,
 			    struct mlxsw_sp_acl_tcam_group *group,
 			    const struct mlxsw_sp_acl_tcam_pattern *patterns,
-			    unsigned int patterns_count)
+			    unsigned int patterns_count,
+			    struct mlxsw_afk_element_usage *tmplt_elusage)
 {
 	int err;
 
 	group->tcam = tcam;
 	group->patterns = patterns;
 	group->patterns_count = patterns_count;
+	if (tmplt_elusage) {
+		group->tmplt_elusage_set = true;
+		memcpy(&group->tmplt_elusage, tmplt_elusage,
+		       sizeof(group->tmplt_elusage));
+	}
 	INIT_LIST_HEAD(&group->region_list);
 	err = mlxsw_sp_acl_tcam_group_id_get(tcam, &group->id);
 	if (err)
@@ -449,6 +457,15 @@ mlxsw_sp_acl_tcam_group_use_patterns(struct mlxsw_sp_acl_tcam_group *group,
 	const struct mlxsw_sp_acl_tcam_pattern *pattern;
 	int i;
 
+	/* In case the template is set, we don't have to look up the pattern
+	 * and just use the template.
+	 */
+	if (group->tmplt_elusage_set) {
+		memcpy(out, &group->tmplt_elusage, sizeof(*out));
+		WARN_ON(!mlxsw_afk_element_usage_subset(elusage, out));
+		return;
+	}
+
 	for (i = 0; i < group->patterns_count; i++) {
 		pattern = &group->patterns[i];
 		mlxsw_afk_element_usage_fill(out, pattern->elements,
@@ -865,13 +882,15 @@ struct mlxsw_sp_acl_tcam_flower_rule {
 static int
 mlxsw_sp_acl_tcam_flower_ruleset_add(struct mlxsw_sp *mlxsw_sp,
 				     struct mlxsw_sp_acl_tcam *tcam,
-				     void *ruleset_priv)
+				     void *ruleset_priv,
+				     struct mlxsw_afk_element_usage *tmplt_elusage)
 {
 	struct mlxsw_sp_acl_tcam_flower_ruleset *ruleset = ruleset_priv;
 
 	return mlxsw_sp_acl_tcam_group_add(mlxsw_sp, tcam, &ruleset->group,
 					   mlxsw_sp_acl_tcam_patterns,
-					   MLXSW_SP_ACL_TCAM_PATTERNS_COUNT);
+					   MLXSW_SP_ACL_TCAM_PATTERNS_COUNT,
+					   tmplt_elusage);
 }
 
 static void
diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.h b/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.h
index 68551da2221d..6403ec4f5267 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.h
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.h
@@ -64,7 +64,8 @@ int mlxsw_sp_acl_tcam_priority_get(struct mlxsw_sp *mlxsw_sp,
 struct mlxsw_sp_acl_profile_ops {
 	size_t ruleset_priv_size;
 	int (*ruleset_add)(struct mlxsw_sp *mlxsw_sp,
-			   struct mlxsw_sp_acl_tcam *tcam, void *ruleset_priv);
+			   struct mlxsw_sp_acl_tcam *tcam, void *ruleset_priv,
+			   struct mlxsw_afk_element_usage *tmplt_elusage);
 	void (*ruleset_del)(struct mlxsw_sp *mlxsw_sp, void *ruleset_priv);
 	int (*ruleset_bind)(struct mlxsw_sp *mlxsw_sp, void *ruleset_priv,
 			    struct mlxsw_sp_port *mlxsw_sp_port,
diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_flower.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_flower.c
index 201761a3539e..b3cb618775af 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_flower.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_flower.c
@@ -414,7 +414,7 @@ int mlxsw_sp_flower_replace(struct mlxsw_sp *mlxsw_sp,
 
 	ruleset = mlxsw_sp_acl_ruleset_get(mlxsw_sp, block,
 					   f->common.chain_index,
-					   MLXSW_SP_ACL_PROFILE_FLOWER);
+					   MLXSW_SP_ACL_PROFILE_FLOWER, NULL);
 	if (IS_ERR(ruleset))
 		return PTR_ERR(ruleset);
 
@@ -458,7 +458,7 @@ void mlxsw_sp_flower_destroy(struct mlxsw_sp *mlxsw_sp,
 
 	ruleset = mlxsw_sp_acl_ruleset_get(mlxsw_sp, block,
 					   f->common.chain_index,
-					   MLXSW_SP_ACL_PROFILE_FLOWER);
+					   MLXSW_SP_ACL_PROFILE_FLOWER, NULL);
 	if (IS_ERR(ruleset))
 		return;
 
@@ -484,7 +484,7 @@ int mlxsw_sp_flower_stats(struct mlxsw_sp *mlxsw_sp,
 
 	ruleset = mlxsw_sp_acl_ruleset_get(mlxsw_sp, block,
 					   f->common.chain_index,
-					   MLXSW_SP_ACL_PROFILE_FLOWER);
+					   MLXSW_SP_ACL_PROFILE_FLOWER, NULL);
 	if (WARN_ON(IS_ERR(ruleset)))
 		return -EINVAL;
 
@@ -506,3 +506,41 @@ err_rule_get_stats:
 	mlxsw_sp_acl_ruleset_put(mlxsw_sp, ruleset);
 	return err;
 }
+
+int mlxsw_sp_flower_tmplt_create(struct mlxsw_sp *mlxsw_sp,
+				 struct mlxsw_sp_acl_block *block,
+				 struct tc_cls_flower_offload *f)
+{
+	struct mlxsw_sp_acl_ruleset *ruleset;
+	struct mlxsw_sp_acl_rule_info rulei;
+	int err;
+
+	memset(&rulei, 0, sizeof(rulei));
+	err = mlxsw_sp_flower_parse(mlxsw_sp, block, &rulei, f);
+	if (err)
+		return err;
+	ruleset = mlxsw_sp_acl_ruleset_get(mlxsw_sp, block,
+					   f->common.chain_index,
+					   MLXSW_SP_ACL_PROFILE_FLOWER,
+					   &rulei.values.elusage);
+	if (IS_ERR(ruleset))
+		return PTR_ERR(ruleset);
+	/* keep the reference to the ruleset */
+	return 0;
+}
+
+void mlxsw_sp_flower_tmplt_destroy(struct mlxsw_sp *mlxsw_sp,
+				   struct mlxsw_sp_acl_block *block,
+				   struct tc_cls_flower_offload *f)
+{
+	struct mlxsw_sp_acl_ruleset *ruleset;
+
+	ruleset = mlxsw_sp_acl_ruleset_get(mlxsw_sp, block,
+					   f->common.chain_index,
+					   MLXSW_SP_ACL_PROFILE_FLOWER, NULL);
+	if (IS_ERR(ruleset))
+		return;
+	/* put the reference to the ruleset kept in create */
+	mlxsw_sp_acl_ruleset_put(mlxsw_sp, ruleset);
+	mlxsw_sp_acl_ruleset_put(mlxsw_sp, ruleset);
+}
diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h
index 4f405ca8346f..a3101582f642 100644
--- a/include/net/pkt_cls.h
+++ b/include/net/pkt_cls.h
@@ -721,6 +721,8 @@ enum tc_fl_command {
 	TC_CLSFLOWER_REPLACE,
 	TC_CLSFLOWER_DESTROY,
 	TC_CLSFLOWER_STATS,
+	TC_CLSFLOWER_TMPLT_CREATE,
+	TC_CLSFLOWER_TMPLT_DESTROY,
 };
 
 struct tc_cls_flower_offload {
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index 7432100027b7..085c509c8674 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -238,6 +238,8 @@ struct tcf_result {
 	};
 };
 
+struct tcf_chain;
+
 struct tcf_proto_ops {
 	struct list_head	head;
 	char			kind[IFNAMSIZ];
@@ -263,10 +265,18 @@ struct tcf_proto_ops {
 					     tc_setup_cb_t *cb, void *cb_priv,
 					     struct netlink_ext_ack *extack);
 	void			(*bind_class)(void *, u32, unsigned long);
+	void *			(*tmplt_create)(struct net *net,
+						struct tcf_chain *chain,
+						struct nlattr **tca,
+						struct netlink_ext_ack *extack);
+	void			(*tmplt_destroy)(void *tmplt_priv);
 
 	/* rtnetlink specific */
 	int			(*dump)(struct net*, struct tcf_proto*, void *,
 					struct sk_buff *skb, struct tcmsg*);
+	int			(*tmplt_dump)(struct sk_buff *skb,
+					      struct net *net,
+					      void *tmplt_priv);
 
 	struct module		*owner;
 };
@@ -300,11 +310,13 @@ typedef void tcf_chain_head_change_t(struct tcf_proto *tp_head, void *priv);
 
 struct tcf_chain {
 	struct tcf_proto __rcu *filter_chain;
-	struct list_head filter_chain_list;
 	struct list_head list;
 	struct tcf_block *block;
 	u32 index; /* chain index */
 	unsigned int refcnt;
+	bool explicitly_created;
+	const struct tcf_proto_ops *tmplt_ops;
+	void *tmplt_priv;
 };
 
 struct tcf_block {
@@ -318,6 +330,10 @@ struct tcf_block {
 	bool keep_dst;
 	unsigned int offloadcnt; /* Number of oddloaded filters */
 	unsigned int nooffloaddevcnt; /* Number of devs unable to do offload */
+	struct {
+		struct tcf_chain *chain;
+		struct list_head filter_chain_list;
+	} chain0;
 };
 
 static inline void tcf_block_offload_inc(struct tcf_block *block, u32 *flags)
diff --git a/include/uapi/linux/rtnetlink.h b/include/uapi/linux/rtnetlink.h
index 7d8502313c99..46399367627f 100644
--- a/include/uapi/linux/rtnetlink.h
+++ b/include/uapi/linux/rtnetlink.h
@@ -150,6 +150,13 @@ enum {
 	RTM_NEWCACHEREPORT = 96,
 #define RTM_NEWCACHEREPORT RTM_NEWCACHEREPORT
 
+	RTM_NEWCHAIN = 100,
+#define RTM_NEWCHAIN RTM_NEWCHAIN
+	RTM_DELCHAIN,
+#define RTM_DELCHAIN RTM_DELCHAIN
+	RTM_GETCHAIN,
+#define RTM_GETCHAIN RTM_GETCHAIN
+
 	__RTM_MAX,
 #define RTM_MAX		(((__RTM_MAX + 3) & ~3) - 1)
 };
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 620067209ba8..5f7098b5405e 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -39,7 +39,7 @@ static DEFINE_RWLOCK(cls_mod_lock);
 
 /* Find classifier type by string name */
 
-static const struct tcf_proto_ops *tcf_proto_lookup_ops(const char *kind)
+static const struct tcf_proto_ops *__tcf_proto_lookup_ops(const char *kind)
 {
 	const struct tcf_proto_ops *t, *res = NULL;
 
@@ -57,6 +57,33 @@ static const struct tcf_proto_ops *tcf_proto_lookup_ops(const char *kind)
 	return res;
 }
 
+static const struct tcf_proto_ops *
+tcf_proto_lookup_ops(const char *kind, struct netlink_ext_ack *extack)
+{
+	const struct tcf_proto_ops *ops;
+
+	ops = __tcf_proto_lookup_ops(kind);
+	if (ops)
+		return ops;
+#ifdef CONFIG_MODULES
+	rtnl_unlock();
+	request_module("cls_%s", kind);
+	rtnl_lock();
+	ops = __tcf_proto_lookup_ops(kind);
+	/* We dropped the RTNL semaphore in order to perform
+	 * the module load. So, even if we succeeded in loading
+	 * the module we have to replay the request. We indicate
+	 * this using -EAGAIN.
+	 */
+	if (ops) {
+		module_put(ops->owner);
+		return ERR_PTR(-EAGAIN);
+	}
+#endif
+	NL_SET_ERR_MSG(extack, "TC classifier not found");
+	return ERR_PTR(-ENOENT);
+}
+
 /* Register(unregister) new classifier type */
 
 int register_tcf_proto_ops(struct tcf_proto_ops *ops)
@@ -133,27 +160,9 @@ static struct tcf_proto *tcf_proto_create(const char *kind, u32 protocol,
 	if (!tp)
 		return ERR_PTR(-ENOBUFS);
 
-	err = -ENOENT;
-	tp->ops = tcf_proto_lookup_ops(kind);
-	if (!tp->ops) {
-#ifdef CONFIG_MODULES
-		rtnl_unlock();
-		request_module("cls_%s", kind);
-		rtnl_lock();
-		tp->ops = tcf_proto_lookup_ops(kind);
-		/* We dropped the RTNL semaphore in order to perform
-		 * the module load. So, even if we succeeded in loading
-		 * the module we have to replay the request. We indicate
-		 * this using -EAGAIN.
-		 */
-		if (tp->ops) {
-			module_put(tp->ops->owner);
-			err = -EAGAIN;
-		} else {
-			NL_SET_ERR_MSG(extack, "TC classifier not found");
-			err = -ENOENT;
-		}
-#endif
+	tp->ops = tcf_proto_lookup_ops(kind, extack);
+	if (IS_ERR(tp->ops)) {
+		err = PTR_ERR(tp->ops);
 		goto errout;
 	}
 	tp->classify = tp->ops->classify;
@@ -195,11 +204,12 @@ static struct tcf_chain *tcf_chain_create(struct tcf_block *block,
 	chain = kzalloc(sizeof(*chain), GFP_KERNEL);
 	if (!chain)
 		return NULL;
-	INIT_LIST_HEAD(&chain->filter_chain_list);
 	list_add_tail(&chain->list, &block->chain_list);
 	chain->block = block;
 	chain->index = chain_index;
 	chain->refcnt = 1;
+	if (!chain->index)
+		block->chain0.chain = chain;
 	return chain;
 }
 
@@ -209,12 +219,16 @@ static void tcf_chain_head_change_item(struct tcf_filter_chain_list_item *item,
 	if (item->chain_head_change)
 		item->chain_head_change(tp_head, item->chain_head_change_priv);
 }
-static void tcf_chain_head_change(struct tcf_chain *chain,
-				  struct tcf_proto *tp_head)
+
+static void tcf_chain0_head_change(struct tcf_chain *chain,
+				   struct tcf_proto *tp_head)
 {
 	struct tcf_filter_chain_list_item *item;
+	struct tcf_block *block = chain->block;
 
-	list_for_each_entry(item, &chain->filter_chain_list, list)
+	if (chain->index)
+		return;
+	list_for_each_entry(item, &block->chain0.filter_chain_list, list)
 		tcf_chain_head_change_item(item, tp_head);
 }
 
@@ -222,7 +236,7 @@ static void tcf_chain_flush(struct tcf_chain *chain)
 {
 	struct tcf_proto *tp = rtnl_dereference(chain->filter_chain);
 
-	tcf_chain_head_change(chain, NULL);
+	tcf_chain0_head_change(chain, NULL);
 	while (tp) {
 		RCU_INIT_POINTER(chain->filter_chain, tp->next);
 		tcf_proto_destroy(tp, NULL);
@@ -236,8 +250,10 @@ static void tcf_chain_destroy(struct tcf_chain *chain)
 	struct tcf_block *block = chain->block;
 
 	list_del(&chain->list);
+	if (!chain->index)
+		block->chain0.chain = NULL;
 	kfree(chain);
-	if (list_empty(&block->chain_list))
+	if (list_empty(&block->chain_list) && block->refcnt == 0)
 		kfree(block);
 }
 
@@ -246,29 +262,60 @@ static void tcf_chain_hold(struct tcf_chain *chain)
 	++chain->refcnt;
 }
 
-struct tcf_chain *tcf_chain_get(struct tcf_block *block, u32 chain_index,
-				bool create)
+static struct tcf_chain *tcf_chain_lookup(struct tcf_block *block,
+					  u32 chain_index)
 {
 	struct tcf_chain *chain;
 
 	list_for_each_entry(chain, &block->chain_list, list) {
-		if (chain->index == chain_index) {
-			tcf_chain_hold(chain);
+		if (chain->index == chain_index)
 			return chain;
-		}
 	}
+	return NULL;
+}
 
-	return create ? tcf_chain_create(block, chain_index) : NULL;
+static int tc_chain_notify(struct tcf_chain *chain, struct sk_buff *oskb,
+			   u32 seq, u16 flags, int event, bool unicast);
+
+struct tcf_chain *tcf_chain_get(struct tcf_block *block, u32 chain_index,
+				bool create)
+{
+	struct tcf_chain *chain = tcf_chain_lookup(block, chain_index);
+
+	if (chain) {
+		tcf_chain_hold(chain);
+		return chain;
+	}
+
+	if (!create)
+		return NULL;
+	chain = tcf_chain_create(block, chain_index);
+	if (!chain)
+		return NULL;
+	tc_chain_notify(chain, NULL, 0, NLM_F_CREATE | NLM_F_EXCL,
+			RTM_NEWCHAIN, false);
+	return chain;
 }
 EXPORT_SYMBOL(tcf_chain_get);
 
+static void tc_chain_tmplt_del(struct tcf_chain *chain);
+
 void tcf_chain_put(struct tcf_chain *chain)
 {
-	if (--chain->refcnt == 0)
+	if (--chain->refcnt == 0) {
+		tc_chain_notify(chain, NULL, 0, 0, RTM_DELCHAIN, false);
+		tc_chain_tmplt_del(chain);
 		tcf_chain_destroy(chain);
+	}
 }
 EXPORT_SYMBOL(tcf_chain_put);
 
+static void tcf_chain_put_explicitly_created(struct tcf_chain *chain)
+{
+	if (chain->explicitly_created)
+		tcf_chain_put(chain);
+}
+
 static bool tcf_block_offload_in_use(struct tcf_block *block)
 {
 	return block->offloadcnt;
@@ -337,10 +384,11 @@ no_offload_dev_dec:
 }
 
 static int
-tcf_chain_head_change_cb_add(struct tcf_chain *chain,
-			     struct tcf_block_ext_info *ei,
-			     struct netlink_ext_ack *extack)
+tcf_chain0_head_change_cb_add(struct tcf_block *block,
+			      struct tcf_block_ext_info *ei,
+			      struct netlink_ext_ack *extack)
 {
+	struct tcf_chain *chain0 = block->chain0.chain;
 	struct tcf_filter_chain_list_item *item;
 
 	item = kmalloc(sizeof(*item), GFP_KERNEL);
@@ -350,23 +398,25 @@ tcf_chain_head_change_cb_add(struct tcf_chain *chain,
 	}
 	item->chain_head_change = ei->chain_head_change;
 	item->chain_head_change_priv = ei->chain_head_change_priv;
-	if (chain->filter_chain)
-		tcf_chain_head_change_item(item, chain->filter_chain);
-	list_add(&item->list, &chain->filter_chain_list);
+	if (chain0 && chain0->filter_chain)
+		tcf_chain_head_change_item(item, chain0->filter_chain);
+	list_add(&item->list, &block->chain0.filter_chain_list);
 	return 0;
 }
 
 static void
-tcf_chain_head_change_cb_del(struct tcf_chain *chain,
-			     struct tcf_block_ext_info *ei)
+tcf_chain0_head_change_cb_del(struct tcf_block *block,
+			      struct tcf_block_ext_info *ei)
 {
+	struct tcf_chain *chain0 = block->chain0.chain;
 	struct tcf_filter_chain_list_item *item;
 
-	list_for_each_entry(item, &chain->filter_chain_list, list) {
+	list_for_each_entry(item, &block->chain0.filter_chain_list, list) {
 		if ((!ei->chain_head_change && !ei->chain_head_change_priv) ||
 		    (item->chain_head_change == ei->chain_head_change &&
 		     item->chain_head_change_priv == ei->chain_head_change_priv)) {
-			tcf_chain_head_change_item(item, NULL);
+			if (chain0)
+				tcf_chain_head_change_item(item, NULL);
 			list_del(&item->list);
 			kfree(item);
 			return;
@@ -402,8 +452,6 @@ static struct tcf_block *tcf_block_create(struct net *net, struct Qdisc *q,
 					  struct netlink_ext_ack *extack)
 {
 	struct tcf_block *block;
-	struct tcf_chain *chain;
-	int err;
 
 	block = kzalloc(sizeof(*block), GFP_KERNEL);
 	if (!block) {
@@ -413,14 +461,8 @@ static struct tcf_block *tcf_block_create(struct net *net, struct Qdisc *q,
 	INIT_LIST_HEAD(&block->chain_list);
 	INIT_LIST_HEAD(&block->cb_list);
 	INIT_LIST_HEAD(&block->owner_list);
+	INIT_LIST_HEAD(&block->chain0.filter_chain_list);
 
-	/* Create chain 0 by default, it has to be always present. */
-	chain = tcf_chain_create(block, 0);
-	if (!chain) {
-		NL_SET_ERR_MSG(extack, "Failed to create new tcf chain");
-		err = -ENOMEM;
-		goto err_chain_create;
-	}
 	block->refcnt = 1;
 	block->net = net;
 	block->index = block_index;
@@ -429,10 +471,6 @@ static struct tcf_block *tcf_block_create(struct net *net, struct Qdisc *q,
 	if (!tcf_block_shared(block))
 		block->q = q;
 	return block;
-
-err_chain_create:
-	kfree(block);
-	return ERR_PTR(err);
 }
 
 static struct tcf_block *tcf_block_lookup(struct net *net, u32 block_index)
@@ -514,11 +552,6 @@ static struct tcf_block *tcf_block_find(struct net *net, struct Qdisc **q,
 	return block;
 }
 
-static struct tcf_chain *tcf_block_chain_zero(struct tcf_block *block)
-{
-	return list_first_entry(&block->chain_list, struct tcf_chain, list);
-}
-
 struct tcf_block_owner_item {
 	struct list_head list;
 	struct Qdisc *q;
@@ -612,10 +645,9 @@ int tcf_block_get_ext(struct tcf_block **p_block, struct Qdisc *q,
 
 	tcf_block_owner_netif_keep_dst(block, q, ei->binder_type);
 
-	err = tcf_chain_head_change_cb_add(tcf_block_chain_zero(block),
-					   ei, extack);
+	err = tcf_chain0_head_change_cb_add(block, ei, extack);
 	if (err)
-		goto err_chain_head_change_cb_add;
+		goto err_chain0_head_change_cb_add;
 
 	err = tcf_block_offload_bind(block, q, ei, extack);
 	if (err)
@@ -625,15 +657,14 @@ int tcf_block_get_ext(struct tcf_block **p_block, struct Qdisc *q,
 	return 0;
 
 err_block_offload_bind:
-	tcf_chain_head_change_cb_del(tcf_block_chain_zero(block), ei);
-err_chain_head_change_cb_add:
+	tcf_chain0_head_change_cb_del(block, ei);
+err_chain0_head_change_cb_add:
 	tcf_block_owner_del(block, q, ei->binder_type);
 err_block_owner_add:
 	if (created) {
 		if (tcf_block_shared(block))
 			tcf_block_remove(block, net);
 err_block_insert:
-		kfree(tcf_block_chain_zero(block));
 		kfree(block);
 	} else {
 		block->refcnt--;
@@ -673,10 +704,10 @@ void tcf_block_put_ext(struct tcf_block *block, struct Qdisc *q,
 
 	if (!block)
 		return;
-	tcf_chain_head_change_cb_del(tcf_block_chain_zero(block), ei);
+	tcf_chain0_head_change_cb_del(block, ei);
 	tcf_block_owner_del(block, q, ei->binder_type);
 
-	if (--block->refcnt == 0) {
+	if (block->refcnt == 1) {
 		if (tcf_block_shared(block))
 			tcf_block_remove(block, block->net);
 
@@ -692,13 +723,16 @@ void tcf_block_put_ext(struct tcf_block *block, struct Qdisc *q,
 
 	tcf_block_offload_unbind(block, q, ei);
 
-	if (block->refcnt == 0) {
+	if (block->refcnt == 1) {
 		/* At this point, all the chains should have refcnt >= 1. */
-		list_for_each_entry_safe(chain, tmp, &block->chain_list, list)
+		list_for_each_entry_safe(chain, tmp, &block->chain_list, list) {
+			tcf_chain_put_explicitly_created(chain);
 			tcf_chain_put(chain);
+		}
 
-		/* Finally, put chain 0 and allow block to be freed. */
-		tcf_chain_put(tcf_block_chain_zero(block));
+		block->refcnt--;
+		if (list_empty(&block->chain_list))
+			kfree(block);
 	}
 }
 EXPORT_SYMBOL(tcf_block_put_ext);
@@ -938,7 +972,7 @@ static void tcf_chain_tp_insert(struct tcf_chain *chain,
 				struct tcf_proto *tp)
 {
 	if (*chain_info->pprev == chain->filter_chain)
-		tcf_chain_head_change(chain, tp);
+		tcf_chain0_head_change(chain, tp);
 	RCU_INIT_POINTER(tp->next, tcf_chain_tp_prev(chain_info));
 	rcu_assign_pointer(*chain_info->pprev, tp);
 	tcf_chain_hold(chain);
@@ -951,7 +985,7 @@ static void tcf_chain_tp_remove(struct tcf_chain *chain,
 	struct tcf_proto *next = rtnl_dereference(chain_info->next);
 
 	if (tp == chain->filter_chain)
-		tcf_chain_head_change(chain, next);
+		tcf_chain0_head_change(chain, next);
 	RCU_INIT_POINTER(*chain_info->pprev, next);
 	tcf_chain_put(chain);
 }
@@ -1227,6 +1261,12 @@ replay:
 		goto errout;
 	}
 
+	if (chain->tmplt_ops && chain->tmplt_ops != tp->ops) {
+		NL_SET_ERR_MSG(extack, "Chain template is set to a different filter kind");
+		err = -EINVAL;
+		goto errout;
+	}
+
 	err = tp->ops->change(net, skb, tp, cl, t->tcm_handle, tca, &fh,
 			      n->nlmsg_flags & NLM_F_CREATE ? TCA_ACT_NOREPLACE : TCA_ACT_REPLACE,
 			      extack);
@@ -1608,6 +1648,320 @@ out:
 	return skb->len;
 }
 
+static int tc_chain_fill_node(struct tcf_chain *chain, struct net *net,
+			      struct sk_buff *skb, struct tcf_block *block,
+			      u32 portid, u32 seq, u16 flags, int event)
+{
+	unsigned char *b = skb_tail_pointer(skb);
+	const struct tcf_proto_ops *ops;
+	struct nlmsghdr *nlh;
+	struct tcmsg *tcm;
+	void *priv;
+
+	ops = chain->tmplt_ops;
+	priv = chain->tmplt_priv;
+
+	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
+	if (!nlh)
+		goto out_nlmsg_trim;
+	tcm = nlmsg_data(nlh);
+	tcm->tcm_family = AF_UNSPEC;
+	tcm->tcm__pad1 = 0;
+	tcm->tcm__pad2 = 0;
+	tcm->tcm_handle = 0;
+	if (block->q) {
+		tcm->tcm_ifindex = qdisc_dev(block->q)->ifindex;
+		tcm->tcm_parent = block->q->handle;
+	} else {
+		tcm->tcm_ifindex = TCM_IFINDEX_MAGIC_BLOCK;
+		tcm->tcm_block_index = block->index;
+	}
+
+	if (nla_put_u32(skb, TCA_CHAIN, chain->index))
+		goto nla_put_failure;
+
+	if (ops) {
+		if (nla_put_string(skb, TCA_KIND, ops->kind))
+			goto nla_put_failure;
+		if (ops->tmplt_dump(skb, net, priv) < 0)
+			goto nla_put_failure;
+	}
+
+	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
+	return skb->len;
+
+out_nlmsg_trim:
+nla_put_failure:
+	nlmsg_trim(skb, b);
+	return -EMSGSIZE;
+}
+
+static int tc_chain_notify(struct tcf_chain *chain, struct sk_buff *oskb,
+			   u32 seq, u16 flags, int event, bool unicast)
+{
+	u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
+	struct tcf_block *block = chain->block;
+	struct net *net = block->net;
+	struct sk_buff *skb;
+
+	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
+	if (!skb)
+		return -ENOBUFS;
+
+	if (tc_chain_fill_node(chain, net, skb, block, portid,
+			       seq, flags, event) <= 0) {
+		kfree_skb(skb);
+		return -EINVAL;
+	}
+
+	if (unicast)
+		return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
+
+	return rtnetlink_send(skb, net, portid, RTNLGRP_TC, flags & NLM_F_ECHO);
+}
+
+static int tc_chain_tmplt_add(struct tcf_chain *chain, struct net *net,
+			      struct nlattr **tca,
+			      struct netlink_ext_ack *extack)
+{
+	const struct tcf_proto_ops *ops;
+	void *tmplt_priv;
+
+	/* If kind is not set, user did not specify template. */
+	if (!tca[TCA_KIND])
+		return 0;
+
+	ops = tcf_proto_lookup_ops(nla_data(tca[TCA_KIND]), extack);
+	if (IS_ERR(ops))
+		return PTR_ERR(ops);
+	if (!ops->tmplt_create || !ops->tmplt_destroy || !ops->tmplt_dump) {
+		NL_SET_ERR_MSG(extack, "Chain templates are not supported with specified classifier");
+		return -EOPNOTSUPP;
+	}
+
+	tmplt_priv = ops->tmplt_create(net, chain, tca, extack);
+	if (IS_ERR(tmplt_priv)) {
+		module_put(ops->owner);
+		return PTR_ERR(tmplt_priv);
+	}
+	chain->tmplt_ops = ops;
+	chain->tmplt_priv = tmplt_priv;
+	return 0;
+}
+
+static void tc_chain_tmplt_del(struct tcf_chain *chain)
+{
+	const struct tcf_proto_ops *ops = chain->tmplt_ops;
+
+	/* If template ops are set, no work to do for us. */
+	if (!ops)
+		return;
+
+	ops->tmplt_destroy(chain->tmplt_priv);
+	module_put(ops->owner);
+}
+
+/* Add/delete/get a chain */
+
+static int tc_ctl_chain(struc