[PATCH 03/10] flow_dissector: add flow action infrastructure

[Pablo Neira Ayuso <pablo@netfilter.org>]

This new infrastructure defines the nic actions that you can perform
from existing network drivers. This infrastructure allows us to avoid a
direct dependency with the native software TC action representation.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 include/net/flow_dissector.h | 70 ++++++++++++++++++++++++++++++++++++++++++++
 net/core/flow_dissector.c    | 18 ++++++++++++
 2 files changed, 88 insertions(+)

diff --git a/include/net/flow_dissector.h b/include/net/flow_dissector.h
index 965a82b8d881..925c208816f1 100644
--- a/include/net/flow_dissector.h
+++ b/include/net/flow_dissector.h
@@ -402,8 +402,78 @@ void flow_rule_match_enc_keyid(const struct flow_rule *rule,
 void flow_rule_match_enc_opts(const struct flow_rule *rule,
 			      struct flow_match_enc_opts *out);
 
+enum flow_action_key_id {
+	FLOW_ACTION_KEY_ACCEPT		= 0,
+	FLOW_ACTION_KEY_DROP,
+	FLOW_ACTION_KEY_TRAP,
+	FLOW_ACTION_KEY_GOTO,
+	FLOW_ACTION_KEY_REDIRECT,
+	FLOW_ACTION_KEY_MIRRED,
+	FLOW_ACTION_KEY_VLAN_PUSH,
+	FLOW_ACTION_KEY_VLAN_POP,
+	FLOW_ACTION_KEY_VLAN_MANGLE,
+	FLOW_ACTION_KEY_TUNNEL_ENCAP,
+	FLOW_ACTION_KEY_TUNNEL_DECAP,
+	FLOW_ACTION_KEY_MANGLE,
+	FLOW_ACTION_KEY_ADD,
+	FLOW_ACTION_KEY_CSUM,
+	FLOW_ACTION_KEY_MARK,
+};
+
+/* This is mirroring enum pedit_header_type definition for easy mapping between
+ * tc pedit action. Legacy TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK is mapped to
+ * FLOW_ACT_MANGLE_UNSPEC, which is supported by no driver.
+ */
+enum flow_act_mangle_base {
+	FLOW_ACT_MANGLE_UNSPEC		= 0,
+	FLOW_ACT_MANGLE_HDR_TYPE_ETH,
+	FLOW_ACT_MANGLE_HDR_TYPE_IP4,
+	FLOW_ACT_MANGLE_HDR_TYPE_IP6,
+	FLOW_ACT_MANGLE_HDR_TYPE_TCP,
+	FLOW_ACT_MANGLE_HDR_TYPE_UDP,
+};
+
+struct flow_action_key {
+	enum flow_action_key_id		id;
+	union {
+		u32			chain_index;	/* FLOW_ACTION_KEY_GOTO */
+		struct net_device	*dev;		/* FLOW_ACTION_KEY_REDIRECT */
+		struct {				/* FLOW_ACTION_KEY_VLAN */
+			u16		vid;
+			__be16		proto;
+			u8		prio;
+		} vlan;
+		struct {				/* FLOW_ACTION_KEY_PACKET_EDIT */
+			enum flow_act_mangle_base htype;
+			u32		offset;
+			u32		mask;
+			u32		val;
+		} mangle;
+		const struct ip_tunnel_info *tunnel;	/* FLOW_ACTION_KEY_TUNNEL_ENCAP */
+		u32			csum_flags;	/* FLOW_ACTION_KEY_CSUM */
+		u32			mark;		/* FLOW_ACTION_KEY_MARK */
+	};
+};
+
+struct flow_action {
+	int			num_keys;
+	struct flow_action_key	*keys;
+};
+
+int flow_action_init(struct flow_action *flow_action, int num_acts);
+void flow_action_free(struct flow_action *flow_action);
+
+static inline bool flow_action_has_keys(const struct flow_action *action)
+{
+	return action->num_keys;
+}
+
+#define flow_action_for_each(__i, __act, __actions)			\
+        for (__i = 0, __act = &(__actions)->keys[0]; __i < (__actions)->num_keys; __act = &(__actions)->keys[++__i])
+
 struct flow_rule {
 	struct flow_match	match;
+	struct flow_action	action;
 };
 
 static inline bool flow_rule_match_key(const struct flow_rule *rule,
diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index 186089b8d852..b9368349f0f7 100644
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c
@@ -258,6 +258,24 @@ void flow_rule_match_enc_opts(const struct flow_rule *rule,
 }
 EXPORT_SYMBOL(flow_rule_match_enc_opts);
 
+int flow_action_init(struct flow_action *flow_action, int num_acts)
+{
+	flow_action->keys = kmalloc(sizeof(struct flow_action_key) * num_acts,
+				    GFP_KERNEL);
+	if (!flow_action->keys)
+		return -ENOMEM;
+
+	flow_action->num_keys = num_acts;
+	return 0;
+}
+EXPORT_SYMBOL(flow_action_init);
+
+void flow_action_free(struct flow_action *flow_action)
+{
+	kfree(flow_action->keys);
+}
+EXPORT_SYMBOL(flow_action_free);
+
 /**
  * __skb_flow_get_ports - extract the upper layer ports and return them
  * @skb: sk_buff to extract the ports from
-- 
2.11.0