net: sched: introduce per-block callbacks

Introduce infrastructure that allows drivers to register callbacks that
are called whenever tc would offload inserted rule for a specific block.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 187 insertions, 0 deletions

diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h
index 5c50af8f7183..4bc6b1cc245d 100644
--- a/include/net/pkt_cls.h
+++ b/include/net/pkt_cls.h
@@ -27,6 +27,8 @@ struct tcf_block_ext_info {
 	enum tcf_block_binder_type binder_type;
 };
 
+struct tcf_block_cb;
+
 #ifdef CONFIG_NET_CLS
 struct tcf_chain *tcf_chain_get(struct tcf_block *block, u32 chain_index,
 				bool create);
@@ -51,6 +53,21 @@ static inline struct net_device *tcf_block_dev(struct tcf_block *block)
 	return tcf_block_q(block)->dev_queue->dev;
 }
 
+void *tcf_block_cb_priv(struct tcf_block_cb *block_cb);
+struct tcf_block_cb *tcf_block_cb_lookup(struct tcf_block *block,
+					 tc_setup_cb_t *cb, void *cb_ident);
+void tcf_block_cb_incref(struct tcf_block_cb *block_cb);
+unsigned int tcf_block_cb_decref(struct tcf_block_cb *block_cb);
+struct tcf_block_cb *__tcf_block_cb_register(struct tcf_block *block,
+					     tc_setup_cb_t *cb, void *cb_ident,
+					     void *cb_priv);
+int tcf_block_cb_register(struct tcf_block *block,
+			  tc_setup_cb_t *cb, void *cb_ident,
+			  void *cb_priv);
+void __tcf_block_cb_unregister(struct tcf_block_cb *block_cb);
+void tcf_block_cb_unregister(struct tcf_block *block,
+			     tc_setup_cb_t *cb, void *cb_ident);
+
 int tcf_classify(struct sk_buff *skb, const struct tcf_proto *tp,
 		 struct tcf_result *res, bool compat_mode);
 
@@ -91,6 +108,70 @@ static inline struct net_device *tcf_block_dev(struct tcf_block *block)
 	return NULL;
 }
 
+static inline
+int tc_setup_cb_block_register(struct tcf_block *block, tc_setup_cb_t *cb,
+			       void *cb_priv)
+{
+	return 0;
+}
+
+static inline
+void tc_setup_cb_block_unregister(struct tcf_block *block, tc_setup_cb_t *cb,
+				  void *cb_priv)
+{
+}
+
+static inline
+void *tcf_block_cb_priv(struct tcf_block_cb *block_cb)
+{
+	return NULL;
+}
+
+static inline
+struct tcf_block_cb *tcf_block_cb_lookup(struct tcf_block *block,
+					 tc_setup_cb_t *cb, void *cb_ident)
+{
+	return NULL;
+}
+
+static inline
+void tcf_block_cb_incref(struct tcf_block_cb *block_cb)
+{
+}
+
+static inline
+unsigned int tcf_block_cb_decref(struct tcf_block_cb *block_cb)
+{
+	return 0;
+}
+
+static inline
+struct tcf_block_cb *__tcf_block_cb_register(struct tcf_block *block,
+					     tc_setup_cb_t *cb, void *cb_ident,
+					     void *cb_priv)
+{
+	return NULL;
+}
+
+static inline
+int tcf_block_cb_register(struct tcf_block *block,
+			  tc_setup_cb_t *cb, void *cb_ident,
+			  void *cb_priv)
+{
+	return 0;
+}
+
+static inline
+void __tcf_block_cb_unregister(struct tcf_block_cb *block_cb)
+{
+}
+
+static inline
+void tcf_block_cb_unregister(struct tcf_block *block,
+			     tc_setup_cb_t *cb, void *cb_ident)
+{
+}
+
 static inline int tcf_classify(struct sk_buff *skb, const struct tcf_proto *tp,
 			       struct tcf_result *res, bool compat_mode)
 {
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index 0aea9e23e97a..031dffd5836c 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -272,6 +272,7 @@ struct tcf_block {
 	struct list_head chain_list;
 	struct net *net;
 	struct Qdisc *q;
+	struct list_head cb_list;
 };
 
 static inline void qdisc_cb_private_validate(const struct sk_buff *skb, int sz)
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 92dce26d10e3..b16c79c47be5 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -278,6 +278,8 @@ int tcf_block_get_ext(struct tcf_block **p_block,
 	if (!block)
 		return -ENOMEM;
 	INIT_LIST_HEAD(&block->chain_list);
+	INIT_LIST_HEAD(&block->cb_list);
+
 	/* Create chain 0 by default, it has to be always present. */
 	chain = tcf_chain_create(block, 0);
 	if (!chain) {
@@ -354,6 +356,109 @@ void tcf_block_put(struct tcf_block *block)
 }
 EXPORT_SYMBOL(tcf_block_put);
 
+struct tcf_block_cb {
+	struct list_head list;
+	tc_setup_cb_t *cb;
+	void *cb_ident;
+	void *cb_priv;
+	unsigned int refcnt;
+};
+
+void *tcf_block_cb_priv(struct tcf_block_cb *block_cb)
+{
+	return block_cb->cb_priv;
+}
+EXPORT_SYMBOL(tcf_block_cb_priv);
+
+struct tcf_block_cb *tcf_block_cb_lookup(struct tcf_block *block,
+					 tc_setup_cb_t *cb, void *cb_ident)
+{	struct tcf_block_cb *block_cb;
+
+	list_for_each_entry(block_cb, &block->cb_list, list)
+		if (block_cb->cb == cb && block_cb->cb_ident == cb_ident)
+			return block_cb;
+	return NULL;
+}
+EXPORT_SYMBOL(tcf_block_cb_lookup);
+
+void tcf_block_cb_incref(struct tcf_block_cb *block_cb)
+{
+	block_cb->refcnt++;
+}
+EXPORT_SYMBOL(tcf_block_cb_incref);
+
+unsigned int tcf_block_cb_decref(struct tcf_block_cb *block_cb)
+{
+	return --block_cb->refcnt;
+}
+EXPORT_SYMBOL(tcf_block_cb_decref);
+
+struct tcf_block_cb *__tcf_block_cb_register(struct tcf_block *block,
+					     tc_setup_cb_t *cb, void *cb_ident,
+					     void *cb_priv)
+{
+	struct tcf_block_cb *block_cb;
+
+	block_cb = kzalloc(sizeof(*block_cb), GFP_KERNEL);
+	if (!block_cb)
+		return NULL;
+	block_cb->cb = cb;
+	block_cb->cb_ident = cb_ident;
+	block_cb->cb_priv = cb_priv;
+	list_add(&block_cb->list, &block->cb_list);
+	return block_cb;
+}
+EXPORT_SYMBOL(__tcf_block_cb_register);
+
+int tcf_block_cb_register(struct tcf_block *block,
+			  tc_setup_cb_t *cb, void *cb_ident,
+			  void *cb_priv)
+{
+	struct tcf_block_cb *block_cb;
+
+	block_cb = __tcf_block_cb_register(block, cb, cb_ident, cb_priv);
+	return block_cb ? 0 : -ENOMEM;
+}
+EXPORT_SYMBOL(tcf_block_cb_register);
+
+void __tcf_block_cb_unregister(struct tcf_block_cb *block_cb)
+{
+	list_del(&block_cb->list);
+	kfree(block_cb);
+}
+EXPORT_SYMBOL(__tcf_block_cb_unregister);
+
+void tcf_block_cb_unregister(struct tcf_block *block,
+			     tc_setup_cb_t *cb, void *cb_ident)
+{
+	struct tcf_block_cb *block_cb;
+
+	block_cb = tcf_block_cb_lookup(block, cb, cb_ident);
+	if (!block_cb)
+		return;
+	__tcf_block_cb_unregister(block_cb);
+}
+EXPORT_SYMBOL(tcf_block_cb_unregister);
+
+static int tcf_block_cb_call(struct tcf_block *block, enum tc_setup_type type,
+			     void *type_data, bool err_stop)
+{
+	struct tcf_block_cb *block_cb;
+	int ok_count = 0;
+	int err;
+
+	list_for_each_entry(block_cb, &block->cb_list, list) {
+		err = block_cb->cb(type, type_data, block_cb->cb_priv);
+		if (err) {
+			if (err_stop)
+				return err;
+		} else {
+			ok_count++;
+		}
+	}
+	return ok_count;
+}
+
 /* Main classifier routine: scans classifier chain attached
  * to this qdisc, (optionally) tests for protocol and asks
  * specific classifiers.