net/sched/act_gact.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * net/sched/act_gact.c		Generic actions
  *
  * copyright 	Jamal Hadi Salim (2002-4)
  */

 #include <linux/types.h>
 #include <linux/kernel.h>
 #include <linux/string.h>
 #include <linux/errno.h>
 #include <linux/skbuff.h>
 #include <linux/rtnetlink.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <net/netlink.h>
 #include <net/pkt_sched.h>
 #include <net/pkt_cls.h>
 #include <linux/tc_act/tc_gact.h>
 #include <net/tc_act/tc_gact.h>

 static struct tc_action_ops act_gact_ops;

 #ifdef CONFIG_GACT_PROB
 static int gact_net_rand(struct tcf_gact *gact)
 {
 	smp_rmb(); /* coupled with smp_wmb() in tcf_gact_init() */
 	if (prandom_u32_max(gact->tcfg_pval))
 		return gact->tcf_action;
 	return gact->tcfg_paction;
 }

 static int gact_determ(struct tcf_gact *gact)
 {
 	u32 pack = atomic_inc_return(&gact->packets);

 	smp_rmb(); /* coupled with smp_wmb() in tcf_gact_init() */
 	if (pack % gact->tcfg_pval)
 		return gact->tcf_action;
 	return gact->tcfg_paction;
 }

 typedef int (*g_rand)(struct tcf_gact *gact);
 static g_rand gact_rand[MAX_RAND] = { NULL, gact_net_rand, gact_determ };
 #endif /* CONFIG_GACT_PROB */

 static const struct nla_policy gact_policy[TCA_GACT_MAX + 1] = {
 	[TCA_GACT_PARMS]	= { .len = sizeof(struct tc_gact) },
 	[TCA_GACT_PROB]		= { .len = sizeof(struct tc_gact_p) },
 };

 static int tcf_gact_init(struct net *net, struct nlattr *nla,
 			 struct nlattr *est, struct tc_action **a,
 			 struct tcf_proto *tp, u32 flags,
 			 struct netlink_ext_ack *extack)
 {
 	struct tc_action_net *tn = net_generic(net, act_gact_ops.net_id);
 	bool bind = flags & TCA_ACT_FLAGS_BIND;
 	struct nlattr *tb[TCA_GACT_MAX + 1];
 	struct tcf_chain *goto_ch = NULL;
 	struct tc_gact *parm;
 	struct tcf_gact *gact;
 	int ret = 0;
 	u32 index;
 	int err;
 #ifdef CONFIG_GACT_PROB
 	struct tc_gact_p *p_parm = NULL;
 #endif

 	if (nla == NULL)
 		return -EINVAL;

 	err = nla_parse_nested_deprecated(tb, TCA_GACT_MAX, nla, gact_policy,
 					  NULL);
 	if (err < 0)
 		return err;

 	if (tb[TCA_GACT_PARMS] == NULL)
 		return -EINVAL;
 	parm = nla_data(tb[TCA_GACT_PARMS]);
 	index = parm->index;

 #ifndef CONFIG_GACT_PROB
 	if (tb[TCA_GACT_PROB] != NULL)
 		return -EOPNOTSUPP;
 #else
 	if (tb[TCA_GACT_PROB]) {
 		p_parm = nla_data(tb[TCA_GACT_PROB]);
 		if (p_parm->ptype >= MAX_RAND)
 			return -EINVAL;
 		if (TC_ACT_EXT_CMP(p_parm->paction, TC_ACT_GOTO_CHAIN)) {
 			NL_SET_ERR_MSG(extack,
 				       "goto chain not allowed on fallback");
 			return -EINVAL;
 		}
 	}
 #endif

 	err = tcf_idr_check_alloc(tn, &index, a, bind);
 	if (!err) {
 		ret = tcf_idr_create_from_flags(tn, index, est, a,
 						&act_gact_ops, bind, flags);
 		if (ret) {
 			tcf_idr_cleanup(tn, index);
 			return ret;
 		}
 		ret = ACT_P_CREATED;
 	} else if (err > 0) {
 		if (bind)/* dont override defaults */
 			return 0;
 		if (!(flags & TCA_ACT_FLAGS_REPLACE)) {
 			tcf_idr_release(*a, bind);
 			return -EEXIST;
 		}
 	} else {
 		return err;
 	}

 	err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
 	if (err < 0)
 		goto release_idr;
 	gact = to_gact(*a);

 	spin_lock_bh(&gact->tcf_lock);
 	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
 #ifdef CONFIG_GACT_PROB
 	if (p_parm) {
 		gact->tcfg_paction = p_parm->paction;
 		gact->tcfg_pval    = max_t(u16, 1, p_parm->pval);
 		/* Make sure tcfg_pval is written before tcfg_ptype
 		 * coupled with smp_rmb() in gact_net_rand() & gact_determ()
 		 */
 		smp_wmb();
 		gact->tcfg_ptype   = p_parm->ptype;
 	}
 #endif
 	spin_unlock_bh(&gact->tcf_lock);

 	if (goto_ch)
 		tcf_chain_put_by_act(goto_ch);

 	return ret;
 release_idr:
 	tcf_idr_release(*a, bind);
 	return err;
 }

 static int tcf_gact_act(struct sk_buff *skb, const struct tc_action *a,
 			struct tcf_result *res)
 {
 	struct tcf_gact *gact = to_gact(a);
 	int action = READ_ONCE(gact->tcf_action);

 #ifdef CONFIG_GACT_PROB
 	{
 	u32 ptype = READ_ONCE(gact->tcfg_ptype);

 	if (ptype)
 		action = gact_rand[ptype](gact);
 	}
 #endif
 	tcf_action_update_bstats(&gact->common, skb);
 	if (action == TC_ACT_SHOT)
 		tcf_action_inc_drop_qstats(&gact->common);

 	tcf_lastuse_update(&gact->tcf_tm);

 	return action;
 }

 static void tcf_gact_stats_update(struct tc_action *a, u64 bytes, u64 packets,
 				  u64 drops, u64 lastuse, bool hw)
 {
 	struct tcf_gact *gact = to_gact(a);
 	int action = READ_ONCE(gact->tcf_action);
 	struct tcf_t *tm = &gact->tcf_tm;

 	tcf_action_update_stats(a, bytes, packets,
 				action == TC_ACT_SHOT ? packets : drops, hw);
 	tm->lastuse = max_t(u64, tm->lastuse, lastuse);
 }

 static int tcf_gact_dump(struct sk_buff *skb, struct tc_action *a,
 			 int bind, int ref)
 {
 	unsigned char *b = skb_tail_pointer(skb);
 	struct tcf_gact *gact = to_gact(a);
 	struct tc_gact opt = {
 		.index   = gact->tcf_index,
 		.refcnt  = refcount_read(&gact->tcf_refcnt) - ref,
 		.bindcnt = atomic_read(&gact->tcf_bindcnt) - bind,
 	};
 	struct tcf_t t;

 	spin_lock_bh(&gact->tcf_lock);
 	opt.action = gact->tcf_action;
 	if (nla_put(skb, TCA_GACT_PARMS, sizeof(opt), &opt))
 		goto nla_put_failure;
 #ifdef CONFIG_GACT_PROB
 	if (gact->tcfg_ptype) {
 		struct tc_gact_p p_opt = {
 			.paction = gact->tcfg_paction,
 			.pval    = gact->tcfg_pval,
 			.ptype   = gact->tcfg_ptype,
 		};

 		if (nla_put(skb, TCA_GACT_PROB, sizeof(p_opt), &p_opt))
 			goto nla_put_failure;
 	}
 #endif
 	tcf_tm_dump(&t, &gact->tcf_tm);
 	if (nla_put_64bit(skb, TCA_GACT_TM, sizeof(t), &t, TCA_GACT_PAD))
 		goto nla_put_failure;
 	spin_unlock_bh(&gact->tcf_lock);

 	return skb->len;

 nla_put_failure:
 	spin_unlock_bh(&gact->tcf_lock);
 	nlmsg_trim(skb, b);
 	return -1;
 }

 static size_t tcf_gact_get_fill_size(const struct tc_action *act)
 {
 	size_t sz = nla_total_size(sizeof(struct tc_gact)); /* TCA_GACT_PARMS */

 #ifdef CONFIG_GACT_PROB
 	if (to_gact(act)->tcfg_ptype)
 		/* TCA_GACT_PROB */
 		sz += nla_total_size(sizeof(struct tc_gact_p));
 #endif

 	return sz;
 }

 static int tcf_gact_offload_act_setup(struct tc_action *act, void *entry_data,
 				      u32 *index_inc, bool bind,
 				      struct netlink_ext_ack *extack)
 {
 	if (bind) {
 		struct flow_action_entry *entry = entry_data;

 		if (is_tcf_gact_ok(act)) {
 			entry->id = FLOW_ACTION_ACCEPT;
 		} else if (is_tcf_gact_shot(act)) {
 			entry->id = FLOW_ACTION_DROP;
 		} else if (is_tcf_gact_trap(act)) {
 			entry->id = FLOW_ACTION_TRAP;
 		} else if (is_tcf_gact_goto_chain(act)) {
 			entry->id = FLOW_ACTION_GOTO;
 			entry->chain_index = tcf_gact_goto_chain_index(act);
 		} else if (is_tcf_gact_continue(act)) {
 			NL_SET_ERR_MSG_MOD(extack, "Offload of \"continue\" action is not supported");
 			return -EOPNOTSUPP;
 		} else if (is_tcf_gact_reclassify(act)) {
 			NL_SET_ERR_MSG_MOD(extack, "Offload of \"reclassify\" action is not supported");
 			return -EOPNOTSUPP;
 		} else if (is_tcf_gact_pipe(act)) {
 			NL_SET_ERR_MSG_MOD(extack, "Offload of \"pipe\" action is not supported");
 			return -EOPNOTSUPP;
 		} else {
 			NL_SET_ERR_MSG_MOD(extack, "Unsupported generic action offload");
 			return -EOPNOTSUPP;
 		}
 		*index_inc = 1;
 	} else {
 		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;
 }

 static struct tc_action_ops act_gact_ops = {
 	.kind		=	"gact",
 	.id		=	TCA_ID_GACT,
 	.owner		=	THIS_MODULE,
 	.act		=	tcf_gact_act,
 	.stats_update	=	tcf_gact_stats_update,
 	.dump		=	tcf_gact_dump,
 	.init		=	tcf_gact_init,
 	.get_fill_size	=	tcf_gact_get_fill_size,
 	.offload_act_setup =	tcf_gact_offload_act_setup,
 	.size		=	sizeof(struct tcf_gact),
 };

 static __net_init int gact_init_net(struct net *net)
 {
 	struct tc_action_net *tn = net_generic(net, act_gact_ops.net_id);

 	return tc_action_net_init(net, tn, &act_gact_ops);
 }

 static void __net_exit gact_exit_net(struct list_head *net_list)
 {
 	tc_action_net_exit(net_list, act_gact_ops.net_id);
 }

 static struct pernet_operations gact_net_ops = {
 	.init = gact_init_net,
 	.exit_batch = gact_exit_net,
 	.id   = &act_gact_ops.net_id,
 	.size = sizeof(struct tc_action_net),
 };

 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
 MODULE_DESCRIPTION("Generic Classifier actions");
 MODULE_LICENSE("GPL");

 static int __init gact_init_module(void)
 {
 #ifdef CONFIG_GACT_PROB
 	pr_info("GACT probability on\n");
 #else
 	pr_info("GACT probability NOT on\n");
 #endif

 	return tcf_register_action(&act_gact_ops, &gact_net_ops);
 }

 static void __exit gact_cleanup_module(void)
 {
 	tcf_unregister_action(&act_gact_ops, &gact_net_ops);
 }

 module_init(gact_init_module);
 module_exit(gact_cleanup_module);
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* net/sched/act_gact.c Generic actions
	*
	* copyright Jamal Hadi Salim (2002-4)
	*/

	#include <linux/types.h>
	#include <linux/kernel.h>
	#include <linux/string.h>
	#include <linux/errno.h>
	#include <linux/skbuff.h>
	#include <linux/rtnetlink.h>
	#include <linux/module.h>
	#include <linux/init.h>
	#include <net/netlink.h>
	#include <net/pkt_sched.h>
	#include <net/pkt_cls.h>
	#include <linux/tc_act/tc_gact.h>
	#include <net/tc_act/tc_gact.h>

	static struct tc_action_ops act_gact_ops;

	#ifdef CONFIG_GACT_PROB
	static int gact_net_rand(struct tcf_gact *gact)
	{
	smp_rmb(); /* coupled with smp_wmb() in tcf_gact_init() */
	if (prandom_u32_max(gact->tcfg_pval))
	return gact->tcf_action;
	return gact->tcfg_paction;
	}

	static int gact_determ(struct tcf_gact *gact)
	{
	u32 pack = atomic_inc_return(&gact->packets);

	smp_rmb(); /* coupled with smp_wmb() in tcf_gact_init() */
	if (pack % gact->tcfg_pval)
	return gact->tcf_action;
	return gact->tcfg_paction;
	}

	typedef int (g_rand)(struct tcf_gact gact);
	static g_rand gact_rand[MAX_RAND] = { NULL, gact_net_rand, gact_determ };
	#endif /* CONFIG_GACT_PROB */

	static const struct nla_policy gact_policy[TCA_GACT_MAX + 1] = {
	[TCA_GACT_PARMS] = { .len = sizeof(struct tc_gact) },
	[TCA_GACT_PROB] = { .len = sizeof(struct tc_gact_p) },
	};

	static int tcf_gact_init(struct net net, struct nlattr nla,
	struct nlattr est, struct tc_action *a,
	struct tcf_proto *tp, u32 flags,
	struct netlink_ext_ack *extack)
	{
	struct tc_action_net *tn = net_generic(net, act_gact_ops.net_id);
	bool bind = flags & TCA_ACT_FLAGS_BIND;
	struct nlattr *tb[TCA_GACT_MAX + 1];
	struct tcf_chain *goto_ch = NULL;
	struct tc_gact *parm;
	struct tcf_gact *gact;
	int ret = 0;
	u32 index;
	int err;
	#ifdef CONFIG_GACT_PROB
	struct tc_gact_p *p_parm = NULL;
	#endif

	if (nla == NULL)
	return -EINVAL;

	err = nla_parse_nested_deprecated(tb, TCA_GACT_MAX, nla, gact_policy,
	NULL);
	if (err < 0)
	return err;

	if (tb[TCA_GACT_PARMS] == NULL)
	return -EINVAL;
	parm = nla_data(tb[TCA_GACT_PARMS]);
	index = parm->index;

	#ifndef CONFIG_GACT_PROB
	if (tb[TCA_GACT_PROB] != NULL)
	return -EOPNOTSUPP;
	#else
	if (tb[TCA_GACT_PROB]) {
	p_parm = nla_data(tb[TCA_GACT_PROB]);
	if (p_parm->ptype >= MAX_RAND)
	return -EINVAL;
	if (TC_ACT_EXT_CMP(p_parm->paction, TC_ACT_GOTO_CHAIN)) {
	NL_SET_ERR_MSG(extack,
	"goto chain not allowed on fallback");
	return -EINVAL;
	}
	}
	#endif

	err = tcf_idr_check_alloc(tn, &index, a, bind);
	if (!err) {
	ret = tcf_idr_create_from_flags(tn, index, est, a,
	&act_gact_ops, bind, flags);
	if (ret) {
	tcf_idr_cleanup(tn, index);
	return ret;
	}
	ret = ACT_P_CREATED;
	} else if (err > 0) {
	if (bind)/* dont override defaults */
	return 0;
	if (!(flags & TCA_ACT_FLAGS_REPLACE)) {
	tcf_idr_release(*a, bind);
	return -EEXIST;
	}
	} else {
	return err;
	}

	err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
	if (err < 0)
	goto release_idr;
	gact = to_gact(*a);

	spin_lock_bh(&gact->tcf_lock);
	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
	#ifdef CONFIG_GACT_PROB
	if (p_parm) {
	gact->tcfg_paction = p_parm->paction;
	gact->tcfg_pval = max_t(u16, 1, p_parm->pval);
	/* Make sure tcfg_pval is written before tcfg_ptype
	* coupled with smp_rmb() in gact_net_rand() & gact_determ()
	*/
	smp_wmb();
	gact->tcfg_ptype = p_parm->ptype;
	}
	#endif
	spin_unlock_bh(&gact->tcf_lock);

	if (goto_ch)
	tcf_chain_put_by_act(goto_ch);

	return ret;
	release_idr:
	tcf_idr_release(*a, bind);
	return err;
	}

	static int tcf_gact_act(struct sk_buff skb, const struct tc_action a,
	struct tcf_result *res)
	{
	struct tcf_gact *gact = to_gact(a);
	int action = READ_ONCE(gact->tcf_action);

	#ifdef CONFIG_GACT_PROB
	{
	u32 ptype = READ_ONCE(gact->tcfg_ptype);

	if (ptype)
	action = gact_rand[ptype](gact);
	}
	#endif
	tcf_action_update_bstats(&gact->common, skb);
	if (action == TC_ACT_SHOT)
	tcf_action_inc_drop_qstats(&gact->common);

	tcf_lastuse_update(&gact->tcf_tm);

	return action;
	}

	static void tcf_gact_stats_update(struct tc_action *a, u64 bytes, u64 packets,
	u64 drops, u64 lastuse, bool hw)
	{
	struct tcf_gact *gact = to_gact(a);
	int action = READ_ONCE(gact->tcf_action);
	struct tcf_t *tm = &gact->tcf_tm;

	tcf_action_update_stats(a, bytes, packets,
	action == TC_ACT_SHOT ? packets : drops, hw);
	tm->lastuse = max_t(u64, tm->lastuse, lastuse);
	}

	static int tcf_gact_dump(struct sk_buff skb, struct tc_action a,
	int bind, int ref)
	{
	unsigned char *b = skb_tail_pointer(skb);
	struct tcf_gact *gact = to_gact(a);
	struct tc_gact opt = {
	.index = gact->tcf_index,
	.refcnt = refcount_read(&gact->tcf_refcnt) - ref,
	.bindcnt = atomic_read(&gact->tcf_bindcnt) - bind,
	};
	struct tcf_t t;

	spin_lock_bh(&gact->tcf_lock);
	opt.action = gact->tcf_action;
	if (nla_put(skb, TCA_GACT_PARMS, sizeof(opt), &opt))
	goto nla_put_failure;
	#ifdef CONFIG_GACT_PROB
	if (gact->tcfg_ptype) {
	struct tc_gact_p p_opt = {
	.paction = gact->tcfg_paction,
	.pval = gact->tcfg_pval,
	.ptype = gact->tcfg_ptype,
	};

	if (nla_put(skb, TCA_GACT_PROB, sizeof(p_opt), &p_opt))
	goto nla_put_failure;
	}
	#endif
	tcf_tm_dump(&t, &gact->tcf_tm);
	if (nla_put_64bit(skb, TCA_GACT_TM, sizeof(t), &t, TCA_GACT_PAD))
	goto nla_put_failure;
	spin_unlock_bh(&gact->tcf_lock);

	return skb->len;

	nla_put_failure:
	spin_unlock_bh(&gact->tcf_lock);
	nlmsg_trim(skb, b);
	return -1;
	}

	static size_t tcf_gact_get_fill_size(const struct tc_action *act)
	{
	size_t sz = nla_total_size(sizeof(struct tc_gact)); /* TCA_GACT_PARMS */

	#ifdef CONFIG_GACT_PROB
	if (to_gact(act)->tcfg_ptype)
	/* TCA_GACT_PROB */
	sz += nla_total_size(sizeof(struct tc_gact_p));
	#endif

	return sz;
	}

	static int tcf_gact_offload_act_setup(struct tc_action act, void entry_data,
	u32 *index_inc, bool bind,
	struct netlink_ext_ack *extack)
	{
	if (bind) {
	struct flow_action_entry *entry = entry_data;

	if (is_tcf_gact_ok(act)) {
	entry->id = FLOW_ACTION_ACCEPT;
	} else if (is_tcf_gact_shot(act)) {
	entry->id = FLOW_ACTION_DROP;
	} else if (is_tcf_gact_trap(act)) {
	entry->id = FLOW_ACTION_TRAP;
	} else if (is_tcf_gact_goto_chain(act)) {
	entry->id = FLOW_ACTION_GOTO;
	entry->chain_index = tcf_gact_goto_chain_index(act);
	} else if (is_tcf_gact_continue(act)) {
	NL_SET_ERR_MSG_MOD(extack, "Offload of \"continue\" action is not supported");
	return -EOPNOTSUPP;
	} else if (is_tcf_gact_reclassify(act)) {
	NL_SET_ERR_MSG_MOD(extack, "Offload of \"reclassify\" action is not supported");
	return -EOPNOTSUPP;
	} else if (is_tcf_gact_pipe(act)) {
	NL_SET_ERR_MSG_MOD(extack, "Offload of \"pipe\" action is not supported");
	return -EOPNOTSUPP;
	} else {
	NL_SET_ERR_MSG_MOD(extack, "Unsupported generic action offload");
	return -EOPNOTSUPP;
	}
	*index_inc = 1;
	} else {
	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;
	}

	static struct tc_action_ops act_gact_ops = {
	.kind = "gact",
	.id = TCA_ID_GACT,
	.owner = THIS_MODULE,
	.act = tcf_gact_act,
	.stats_update = tcf_gact_stats_update,
	.dump = tcf_gact_dump,
	.init = tcf_gact_init,
	.get_fill_size = tcf_gact_get_fill_size,
	.offload_act_setup = tcf_gact_offload_act_setup,
	.size = sizeof(struct tcf_gact),
	};

	static __net_init int gact_init_net(struct net *net)
	{
	struct tc_action_net *tn = net_generic(net, act_gact_ops.net_id);

	return tc_action_net_init(net, tn, &act_gact_ops);
	}

	static void __net_exit gact_exit_net(struct list_head *net_list)
	{
	tc_action_net_exit(net_list, act_gact_ops.net_id);
	}

	static struct pernet_operations gact_net_ops = {
	.init = gact_init_net,
	.exit_batch = gact_exit_net,
	.id = &act_gact_ops.net_id,
	.size = sizeof(struct tc_action_net),
	};

	MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
	MODULE_DESCRIPTION("Generic Classifier actions");
	MODULE_LICENSE("GPL");

	static int __init gact_init_module(void)
	{
	#ifdef CONFIG_GACT_PROB
	pr_info("GACT probability on\n");
	#else
	pr_info("GACT probability NOT on\n");
	#endif

	return tcf_register_action(&act_gact_ops, &gact_net_ops);
	}

	static void __exit gact_cleanup_module(void)
	{
	tcf_unregister_action(&act_gact_ops, &gact_net_ops);
	}

	module_init(gact_init_module);
	module_exit(gact_cleanup_module);