flow_offload: allow user to offload tc action to net device

Use flow_indr_dev_register/flow_indr_dev_setup_offload to
offload tc action.

We need to call tc_cleanup_flow_action to clean up tc action entry since
in tc_setup_action, some actions may hold dev refcnt, especially the mirror
action.

Signed-off-by: Baowen Zheng <[email protected]>
Signed-off-by: Louis Peens <[email protected]>
Signed-off-by: Simon Horman <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

Author: zhengbaowen

include/linux/netdevice.h

@@ -920,6 +920,7 @@ enum tc_setup_type {
 	TC_SETUP_QDISC_TBF,
 	TC_SETUP_QDISC_FIFO,
 	TC_SETUP_QDISC_HTB,
+	TC_SETUP_ACT,
 };
 
 /* These structures hold the attributes of bpf state that are being passed

include/net/flow_offload.h

@@ -551,6 +551,23 @@ struct flow_cls_offload {
 	u32 classid;
 };
 
+enum offload_act_command  {
+	FLOW_ACT_REPLACE,
+	FLOW_ACT_DESTROY,
+	FLOW_ACT_STATS,
+};
+
+struct flow_offload_action {
+	struct netlink_ext_ack *extack; /* NULL in FLOW_ACT_STATS process*/
+	enum offload_act_command  command;
+	enum flow_action_id id;
+	u32 index;
+	struct flow_stats stats;
+	struct flow_action action;
+};
+
+struct flow_offload_action *offload_action_alloc(unsigned int num_actions);
+
 static inline struct flow_rule *
 flow_cls_offload_flow_rule(struct flow_cls_offload *flow_cmd)
 {

include/net/pkt_cls.h

@@ -262,6 +262,9 @@ static inline void tcf_exts_put_net(struct tcf_exts *exts)
 	for (; 0; (void)(i), (void)(a), (void)(exts))
 #endif
 
+#define tcf_act_for_each_action(i, a, actions) \
+	for (i = 0; i < TCA_ACT_MAX_PRIO && ((a) = actions[i]); i++)
+
 static inline void
 tcf_exts_stats_update(const struct tcf_exts *exts,
 		      u64 bytes, u64 packets, u64 drops, u64 lastuse,
@@ -539,6 +542,8 @@ tcf_match_indev(struct sk_buff *skb, int ifindex)
 int tc_setup_offload_action(struct flow_action *flow_action,
 			    const struct tcf_exts *exts);
 void tc_cleanup_offload_action(struct flow_action *flow_action);
+int tc_setup_action(struct flow_action *flow_action,
+		    struct tc_action *actions[]);
 
 int tc_setup_cb_call(struct tcf_block *block, enum tc_setup_type type,
 		     void *type_data, bool err_stop, bool rtnl_held);

net/core/flow_offload.c

@@ -27,6 +27,26 @@ struct flow_rule *flow_rule_alloc(unsigned int num_actions)
 }
 EXPORT_SYMBOL(flow_rule_alloc);
 
+struct flow_offload_action *offload_action_alloc(unsigned int num_actions)
+{
+	struct flow_offload_action *fl_action;
+	int i;
+
+	fl_action = kzalloc(struct_size(fl_action, action.entries, num_actions),
+			    GFP_KERNEL);
+	if (!fl_action)
+		return NULL;
+
+	fl_action->action.num_entries = num_actions;
+	/* Pre-fill each action hw_stats with DONT_CARE.
+	 * Caller can override this if it wants stats for a given action.
+	 */
+	for (i = 0; i < num_actions; i++)
+		fl_action->action.entries[i].hw_stats = FLOW_ACTION_HW_STATS_DONT_CARE;
+
+	return fl_action;
+}
+
 #define FLOW_DISSECTOR_MATCH(__rule, __type, __out)				\
 	const struct flow_match *__m = &(__rule)->match;			\
 	struct flow_dissector *__d = (__m)->dissector;				\
@@ -549,19 +569,25 @@ int flow_indr_dev_setup_offload(struct net_device *dev,	struct Qdisc *sch,
 				void (*cleanup)(struct flow_block_cb *block_cb))
 {
 	struct flow_indr_dev *this;
+	u32 count = 0;
+	int err;
 
 	mutex_lock(&flow_indr_block_lock);
+	if (bo) {
+		if (bo->command == FLOW_BLOCK_BIND)
+			indir_dev_add(data, dev, sch, type, cleanup, bo);
+		else if (bo->command == FLOW_BLOCK_UNBIND)
+			indir_dev_remove(data);
+	}
 
-	if (bo->command == FLOW_BLOCK_BIND)
-		indir_dev_add(data, dev, sch, type, cleanup, bo);
-	else if (bo->command == FLOW_BLOCK_UNBIND)
-		indir_dev_remove(data);
-
-	list_for_each_entry(this, &flow_block_indr_dev_list, list)
-		this->cb(dev, sch, this->cb_priv, type, bo, data, cleanup);
+	list_for_each_entry(this, &flow_block_indr_dev_list, list) {
+		err = this->cb(dev, sch, this->cb_priv, type, bo, data, cleanup);
+		if (!err)
+			count++;
+	}
 
 	mutex_unlock(&flow_indr_block_lock);
 
-	return list_empty(&bo->cb_list) ? -EOPNOTSUPP : 0;
+	return (bo && list_empty(&bo->cb_list)) ? -EOPNOTSUPP : count;
 }
 EXPORT_SYMBOL(flow_indr_dev_setup_offload);

net/sched/act_api.c

@@ -19,8 +19,10 @@
 #include <net/sock.h>
 #include <net/sch_generic.h>
 #include <net/pkt_cls.h>
+#include <net/tc_act/tc_pedit.h>
 #include <net/act_api.h>
 #include <net/netlink.h>
+#include <net/flow_offload.h>
 
 #ifdef CONFIG_INET
 DEFINE_STATIC_KEY_FALSE(tcf_frag_xmit_count);
@@ -129,8 +131,92 @@ static void free_tcf(struct tc_action *p)
 	kfree(p);
 }
 
+static unsigned int tcf_offload_act_num_actions_single(struct tc_action *act)
+{
+	if (is_tcf_pedit(act))
+		return tcf_pedit_nkeys(act);
+	else
+		return 1;
+}
+
+static int offload_action_init(struct flow_offload_action *fl_action,
+			       struct tc_action *act,
+			       enum offload_act_command  cmd,
+			       struct netlink_ext_ack *extack)
+{
+	fl_action->extack = extack;
+	fl_action->command = cmd;
+	fl_action->index = act->tcfa_index;
+
+	if (act->ops->offload_act_setup)
+		return act->ops->offload_act_setup(act, fl_action, NULL, false);
+
+	return -EOPNOTSUPP;
+}
+
+static int tcf_action_offload_cmd(struct flow_offload_action *fl_act,
+				  struct netlink_ext_ack *extack)
+{
+	int err;
+
+	err = flow_indr_dev_setup_offload(NULL, NULL, TC_SETUP_ACT,
+					  fl_act, NULL, NULL);
+	if (err < 0)
+		return err;
+
+	return 0;
+}
+
+/* offload the tc action after it is inserted */
+static int tcf_action_offload_add(struct tc_action *action,
+				  struct netlink_ext_ack *extack)
+{
+	struct tc_action *actions[TCA_ACT_MAX_PRIO] = {
+		[0] = action,
+	};
+	struct flow_offload_action *fl_action;
+	int num, err = 0;
+
+	num = tcf_offload_act_num_actions_single(action);
+	fl_action = offload_action_alloc(num);
+	if (!fl_action)
+		return -ENOMEM;
+
+	err = offload_action_init(fl_action, action, FLOW_ACT_REPLACE, extack);
+	if (err)
+		goto fl_err;
+
+	err = tc_setup_action(&fl_action->action, actions);
+	if (err) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Failed to setup tc actions for offload\n");
+		goto fl_err;
+	}
+
+	err = tcf_action_offload_cmd(fl_action, extack);
+	tc_cleanup_offload_action(&fl_action->action);
+
+fl_err:
+	kfree(fl_action);
+
+	return err;
+}
+
+static int tcf_action_offload_del(struct tc_action *action)
+{
+	struct flow_offload_action fl_act = {};
+	int err = 0;
+
+	err = offload_action_init(&fl_act, action, FLOW_ACT_DESTROY, NULL);
+	if (err)
+		return err;
+
+	return tcf_action_offload_cmd(&fl_act, NULL);
+}
+
 static void tcf_action_cleanup(struct tc_action *p)
 {
+	tcf_action_offload_del(p);
 	if (p->ops->cleanup)
 		p->ops->cleanup(p);
 
@@ -1061,6 +1147,11 @@ struct tc_action *tcf_action_init_1(struct net *net, struct tcf_proto *tp,
 	return ERR_PTR(err);
 }
 
+static bool tc_act_bind(u32 flags)
+{
+	return !!(flags & TCA_ACT_FLAGS_BIND);
+}
+
 /* Returns numbers of initialized actions or negative error. */
 
 int tcf_action_init(struct net *net, struct tcf_proto *tp, struct nlattr *nla,
@@ -1103,6 +1194,8 @@ int tcf_action_init(struct net *net, struct tcf_proto *tp, struct nlattr *nla,
 		sz += tcf_action_fill_size(act);
 		/* Start from index 0 */
 		actions[i - 1] = act;
+		if (!tc_act_bind(flags))
+			tcf_action_offload_add(act, extack);
 	}
 
 	/* We have to commit them all together, because if any error happened in

net/sched/act_csum.c

@@ -705,7 +705,9 @@ static int tcf_csum_offload_act_setup(struct tc_action *act, void *entry_data,
 		entry->csum_flags = tcf_csum_update_flags(act);
 		*index_inc = 1;
 	} else {
-		return -EOPNOTSUPP;
+		struct flow_offload_action *fl_action = entry_data;
+
+		fl_action->id = FLOW_ACTION_CSUM;
 	}
 
 	return 0;

net/sched/act_ct.c

@@ -1505,7 +1505,9 @@ static int tcf_ct_offload_act_setup(struct tc_action *act, void *entry_data,
 		entry->ct.flow_table = tcf_ct_ft(act);
 		*index_inc = 1;
 	} else {
-		return -EOPNOTSUPP;
+		struct flow_offload_action *fl_action = entry_data;
+
+		fl_action->id = FLOW_ACTION_CT;
 	}
 
 	return 0;

net/sched/act_gact.c

@@ -272,7 +272,18 @@ static int tcf_gact_offload_act_setup(struct tc_action *act, void *entry_data,
 		}
 		*index_inc = 1;
 	} else {
-		return -EOPNOTSUPP;
+		struct flow_offload_action *fl_action = entry_data;
+
+		if (is_tcf_gact_ok(act))
+			fl_action->id = FLOW_ACTION_ACCEPT;
+		else if (is_tcf_gact_shot(act))
+			fl_action->id = FLOW_ACTION_DROP;
+		else if (is_tcf_gact_trap(act))
+			fl_action->id = FLOW_ACTION_TRAP;
+		else if (is_tcf_gact_goto_chain(act))
+			fl_action->id = FLOW_ACTION_GOTO;
+		else
+			return -EOPNOTSUPP;
 	}
 
 	return 0;

net/sched/act_gate.c

@@ -637,7 +637,9 @@ static int tcf_gate_offload_act_setup(struct tc_action *act, void *entry_data,
 			return err;
 		*index_inc = 1;
 	} else {
-		return -EOPNOTSUPP;
+		struct flow_offload_action *fl_action = entry_data;
+
+		fl_action->id = FLOW_ACTION_GATE;
 	}
 
 	return 0;

net/sched/act_mirred.c

@@ -482,7 +482,18 @@ static int tcf_mirred_offload_act_setup(struct tc_action *act, void *entry_data,
 		}
 		*index_inc = 1;
 	} else {
-		return -EOPNOTSUPP;
+		struct flow_offload_action *fl_action = entry_data;
+
+		if (is_tcf_mirred_egress_redirect(act))
+			fl_action->id = FLOW_ACTION_REDIRECT;
+		else if (is_tcf_mirred_egress_mirror(act))
+			fl_action->id = FLOW_ACTION_MIRRED;
+		else if (is_tcf_mirred_ingress_redirect(act))
+			fl_action->id = FLOW_ACTION_REDIRECT_INGRESS;
+		else if (is_tcf_mirred_ingress_mirror(act))
+			fl_action->id = FLOW_ACTION_MIRRED_INGRESS;
+		else
+			return -EOPNOTSUPP;
 	}
 
 	return 0;

net/sched/act_mpls.c

@@ -415,7 +415,21 @@ static int tcf_mpls_offload_act_setup(struct tc_action *act, void *entry_data,
 		}
 		*index_inc = 1;
 	} else {
-		return -EOPNOTSUPP;
+		struct flow_offload_action *fl_action = entry_data;
+
+		switch (tcf_mpls_action(act)) {
+		case TCA_MPLS_ACT_PUSH:
+			fl_action->id = FLOW_ACTION_MPLS_PUSH;
+			break;
+		case TCA_MPLS_ACT_POP:
+			fl_action->id = FLOW_ACTION_MPLS_POP;
+			break;
+		case TCA_MPLS_ACT_MODIFY:
+			fl_action->id = FLOW_ACTION_MPLS_MANGLE;
+			break;
+		default:
+			return -EOPNOTSUPP;
+		}
 	}
 
 	return 0;

net/sched/act_police.c

@@ -421,7 +421,9 @@ static int tcf_police_offload_act_setup(struct tc_action *act, void *entry_data,
 		entry->police.mtu = tcf_police_tcfp_mtu(act);
 		*index_inc = 1;
 	} else {
-		return -EOPNOTSUPP;
+		struct flow_offload_action *fl_action = entry_data;
+
+		fl_action->id = FLOW_ACTION_POLICE;
 	}
 
 	return 0;

net/sched/act_sample.c

@@ -303,7 +303,9 @@ static int tcf_sample_offload_act_setup(struct tc_action *act, void *entry_data,
 		tcf_offload_sample_get_group(entry, act);
 		*index_inc = 1;
 	} else {
-		return -EOPNOTSUPP;
+		struct flow_offload_action *fl_action = entry_data;
+
+		fl_action->id = FLOW_ACTION_SAMPLE;
 	}
 
 	return 0;

net/sched/act_skbedit.c

@@ -347,7 +347,16 @@ static int tcf_skbedit_offload_act_setup(struct tc_action *act, void *entry_data
 		}
 		*index_inc = 1;
 	} else {
-		return -EOPNOTSUPP;
+		struct flow_offload_action *fl_action = entry_data;
+
+		if (is_tcf_skbedit_mark(act))
+			fl_action->id = FLOW_ACTION_MARK;
+		else if (is_tcf_skbedit_ptype(act))
+			fl_action->id = FLOW_ACTION_PTYPE;
+		else if (is_tcf_skbedit_priority(act))
+			fl_action->id = FLOW_ACTION_PRIORITY;
+		else
+			return -EOPNOTSUPP;
 	}
 
 	return 0;

net/sched/act_tunnel_key.c

@@ -827,7 +827,14 @@ static int tcf_tunnel_key_offload_act_setup(struct tc_action *act,
 		}
 		*index_inc = 1;
 	} else {
-		return -EOPNOTSUPP;
+		struct flow_offload_action *fl_action = entry_data;
+
+		if (is_tcf_tunnel_set(act))
+			fl_action->id = FLOW_ACTION_TUNNEL_ENCAP;
+		else if (is_tcf_tunnel_release(act))
+			fl_action->id = FLOW_ACTION_TUNNEL_DECAP;
+		else
+			return -EOPNOTSUPP;
 	}
 
 	return 0;