1 files changed, 372 insertions, 0 deletions

diff --git a/net/sched/act_police.c b/net/sched/act_police.c
new file mode 100644
index 000000000..9a1c42a43
--- /dev/null
+++ b/net/sched/act_police.c
@@ -0,0 +1,372 @@
+/*
+ * net/sched/act_police.c	Input police filter
+ *
+ *		This program is free software; you can redistribute it and/or
+ *		modify it under the terms of the GNU General Public License
+ *		as published by the Free Software Foundation; either version
+ *		2 of the License, or (at your option) any later version.
+ *
+ * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
+ * 		J Hadi Salim (action changes)
+ */
+
+#include <linux/module.h>
+#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/init.h>
+#include <linux/slab.h>
+#include <net/act_api.h>
+#include <net/netlink.h>
+
+struct tcf_police {
+	struct tcf_common	common;
+	int			tcfp_result;
+	u32			tcfp_ewma_rate;
+	s64			tcfp_burst;
+	u32			tcfp_mtu;
+	s64			tcfp_toks;
+	s64			tcfp_ptoks;
+	s64			tcfp_mtu_ptoks;
+	s64			tcfp_t_c;
+	struct psched_ratecfg	rate;
+	bool			rate_present;
+	struct psched_ratecfg	peak;
+	bool			peak_present;
+};
+#define to_police(pc)	\
+	container_of(pc, struct tcf_police, common)
+
+#define POL_TAB_MASK     15
+
+/* old policer structure from before tc actions */
+struct tc_police_compat {
+	u32			index;
+	int			action;
+	u32			limit;
+	u32			burst;
+	u32			mtu;
+	struct tc_ratespec	rate;
+	struct tc_ratespec	peakrate;
+};
+
+/* Each policer is serialized by its individual spinlock */
+
+static int tcf_act_police_walker(struct sk_buff *skb, struct netlink_callback *cb,
+			      int type, struct tc_action *a)
+{
+	struct tcf_hashinfo *hinfo = a->ops->hinfo;
+	struct hlist_head *head;
+	struct tcf_common *p;
+	int err = 0, index = -1, i = 0, s_i = 0, n_i = 0;
+	struct nlattr *nest;
+
+	spin_lock_bh(&hinfo->lock);
+
+	s_i = cb->args[0];
+
+	for (i = 0; i < (POL_TAB_MASK + 1); i++) {
+		head = &hinfo->htab[tcf_hash(i, POL_TAB_MASK)];
+
+		hlist_for_each_entry_rcu(p, head, tcfc_head) {
+			index++;
+			if (index < s_i)
+				continue;
+			a->priv = p;
+			a->order = index;
+			nest = nla_nest_start(skb, a->order);
+			if (nest == NULL)
+				goto nla_put_failure;
+			if (type == RTM_DELACTION)
+				err = tcf_action_dump_1(skb, a, 0, 1);
+			else
+				err = tcf_action_dump_1(skb, a, 0, 0);
+			if (err < 0) {
+				index--;
+				nla_nest_cancel(skb, nest);
+				goto done;
+			}
+			nla_nest_end(skb, nest);
+			n_i++;
+		}
+	}
+done:
+	spin_unlock_bh(&hinfo->lock);
+	if (n_i)
+		cb->args[0] += n_i;
+	return n_i;
+
+nla_put_failure:
+	nla_nest_cancel(skb, nest);
+	goto done;
+}
+
+static const struct nla_policy police_policy[TCA_POLICE_MAX + 1] = {
+	[TCA_POLICE_RATE]	= { .len = TC_RTAB_SIZE },
+	[TCA_POLICE_PEAKRATE]	= { .len = TC_RTAB_SIZE },
+	[TCA_POLICE_AVRATE]	= { .type = NLA_U32 },
+	[TCA_POLICE_RESULT]	= { .type = NLA_U32 },
+};
+
+static int tcf_act_police_locate(struct net *net, struct nlattr *nla,
+				 struct nlattr *est, struct tc_action *a,
+				 int ovr, int bind)
+{
+	unsigned int h;
+	int ret = 0, err;
+	struct nlattr *tb[TCA_POLICE_MAX + 1];
+	struct tc_police *parm;
+	struct tcf_police *police;
+	struct qdisc_rate_table *R_tab = NULL, *P_tab = NULL;
+	struct tcf_hashinfo *hinfo = a->ops->hinfo;
+	int size;
+
+	if (nla == NULL)
+		return -EINVAL;
+
+	err = nla_parse_nested(tb, TCA_POLICE_MAX, nla, police_policy);
+	if (err < 0)
+		return err;
+
+	if (tb[TCA_POLICE_TBF] == NULL)
+		return -EINVAL;
+	size = nla_len(tb[TCA_POLICE_TBF]);
+	if (size != sizeof(*parm) && size != sizeof(struct tc_police_compat))
+		return -EINVAL;
+	parm = nla_data(tb[TCA_POLICE_TBF]);
+
+	if (parm->index) {
+		if (tcf_hash_search(a, parm->index)) {
+			police = to_police(a->priv);
+			if (bind) {
+				police->tcf_bindcnt += 1;
+				police->tcf_refcnt += 1;
+				return 0;
+			}
+			if (ovr)
+				goto override;
+			/* not replacing */
+			return -EEXIST;
+		}
+	}
+
+	police = kzalloc(sizeof(*police), GFP_KERNEL);
+	if (police == NULL)
+		return -ENOMEM;
+	ret = ACT_P_CREATED;
+	police->tcf_refcnt = 1;
+	spin_lock_init(&police->tcf_lock);
+	if (bind)
+		police->tcf_bindcnt = 1;
+override:
+	if (parm->rate.rate) {
+		err = -ENOMEM;
+		R_tab = qdisc_get_rtab(&parm->rate, tb[TCA_POLICE_RATE]);
+		if (R_tab == NULL)
+			goto failure;
+
+		if (parm->peakrate.rate) {
+			P_tab = qdisc_get_rtab(&parm->peakrate,
+					       tb[TCA_POLICE_PEAKRATE]);
+			if (P_tab == NULL)
+				goto failure;
+		}
+	}
+
+	spin_lock_bh(&police->tcf_lock);
+	if (est) {
+		err = gen_replace_estimator(&police->tcf_bstats, NULL,
+					    &police->tcf_rate_est,
+					    &police->tcf_lock, est);
+		if (err)
+			goto failure_unlock;
+	} else if (tb[TCA_POLICE_AVRATE] &&
+		   (ret == ACT_P_CREATED ||
+		    !gen_estimator_active(&police->tcf_bstats,
+					  &police->tcf_rate_est))) {
+		err = -EINVAL;
+		goto failure_unlock;
+	}
+
+	/* No failure allowed after this point */
+	police->tcfp_mtu = parm->mtu;
+	if (police->tcfp_mtu == 0) {
+		police->tcfp_mtu = ~0;
+		if (R_tab)
+			police->tcfp_mtu = 255 << R_tab->rate.cell_log;
+	}
+	if (R_tab) {
+		police->rate_present = true;
+		psched_ratecfg_precompute(&police->rate, &R_tab->rate, 0);
+		qdisc_put_rtab(R_tab);
+	} else {
+		police->rate_present = false;
+	}
+	if (P_tab) {
+		police->peak_present = true;
+		psched_ratecfg_precompute(&police->peak, &P_tab->rate, 0);
+		qdisc_put_rtab(P_tab);
+	} else {
+		police->peak_present = false;
+	}
+
+	if (tb[TCA_POLICE_RESULT])
+		police->tcfp_result = nla_get_u32(tb[TCA_POLICE_RESULT]);
+	police->tcfp_burst = PSCHED_TICKS2NS(parm->burst);
+	police->tcfp_toks = police->tcfp_burst;
+	if (police->peak_present) {
+		police->tcfp_mtu_ptoks = (s64) psched_l2t_ns(&police->peak,
+							     police->tcfp_mtu);
+		police->tcfp_ptoks = police->tcfp_mtu_ptoks;
+	}
+	police->tcf_action = parm->action;
+
+	if (tb[TCA_POLICE_AVRATE])
+		police->tcfp_ewma_rate = nla_get_u32(tb[TCA_POLICE_AVRATE]);
+
+	spin_unlock_bh(&police->tcf_lock);
+	if (ret != ACT_P_CREATED)
+		return ret;
+
+	police->tcfp_t_c = ktime_get_ns();
+	police->tcf_index = parm->index ? parm->index :
+		tcf_hash_new_index(hinfo);
+	h = tcf_hash(police->tcf_index, POL_TAB_MASK);
+	spin_lock_bh(&hinfo->lock);
+	hlist_add_head(&police->tcf_head, &hinfo->htab[h]);
+	spin_unlock_bh(&hinfo->lock);
+
+	a->priv = police;
+	return ret;
+
+failure_unlock:
+	spin_unlock_bh(&police->tcf_lock);
+failure:
+	qdisc_put_rtab(P_tab);
+	qdisc_put_rtab(R_tab);
+	if (ret == ACT_P_CREATED)
+		kfree(police);
+	return err;
+}
+
+static int tcf_act_police(struct sk_buff *skb, const struct tc_action *a,
+			  struct tcf_result *res)
+{
+	struct tcf_police *police = a->priv;
+	s64 now;
+	s64 toks;
+	s64 ptoks = 0;
+
+	spin_lock(&police->tcf_lock);
+
+	bstats_update(&police->tcf_bstats, skb);
+
+	if (police->tcfp_ewma_rate &&
+	    police->tcf_rate_est.bps >= police->tcfp_ewma_rate) {
+		police->tcf_qstats.overlimits++;
+		if (police->tcf_action == TC_ACT_SHOT)
+			police->tcf_qstats.drops++;
+		spin_unlock(&police->tcf_lock);
+		return police->tcf_action;
+	}
+
+	if (qdisc_pkt_len(skb) <= police->tcfp_mtu) {
+		if (!police->rate_present) {
+			spin_unlock(&police->tcf_lock);
+			return police->tcfp_result;
+		}
+
+		now = ktime_get_ns();
+		toks = min_t(s64, now - police->tcfp_t_c,
+			     police->tcfp_burst);
+		if (police->peak_present) {
+			ptoks = toks + police->tcfp_ptoks;
+			if (ptoks > police->tcfp_mtu_ptoks)
+				ptoks = police->tcfp_mtu_ptoks;
+			ptoks -= (s64) psched_l2t_ns(&police->peak,
+						     qdisc_pkt_len(skb));
+		}
+		toks += police->tcfp_toks;
+		if (toks > police->tcfp_burst)
+			toks = police->tcfp_burst;
+		toks -= (s64) psched_l2t_ns(&police->rate, qdisc_pkt_len(skb));
+		if ((toks|ptoks) >= 0) {
+			police->tcfp_t_c = now;
+			police->tcfp_toks = toks;
+			police->tcfp_ptoks = ptoks;
+			spin_unlock(&police->tcf_lock);
+			return police->tcfp_result;
+		}
+	}
+
+	police->tcf_qstats.overlimits++;
+	if (police->tcf_action == TC_ACT_SHOT)
+		police->tcf_qstats.drops++;
+	spin_unlock(&police->tcf_lock);
+	return police->tcf_action;
+}
+
+static int
+tcf_act_police_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
+{
+	unsigned char *b = skb_tail_pointer(skb);
+	struct tcf_police *police = a->priv;
+	struct tc_police opt = {
+		.index = police->tcf_index,
+		.action = police->tcf_action,
+		.mtu = police->tcfp_mtu,
+		.burst = PSCHED_NS2TICKS(police->tcfp_burst),
+		.refcnt = police->tcf_refcnt - ref,
+		.bindcnt = police->tcf_bindcnt - bind,
+	};
+
+	if (police->rate_present)
+		psched_ratecfg_getrate(&opt.rate, &police->rate);
+	if (police->peak_present)
+		psched_ratecfg_getrate(&opt.peakrate, &police->peak);
+	if (nla_put(skb, TCA_POLICE_TBF, sizeof(opt), &opt))
+		goto nla_put_failure;
+	if (police->tcfp_result &&
+	    nla_put_u32(skb, TCA_POLICE_RESULT, police->tcfp_result))
+		goto nla_put_failure;
+	if (police->tcfp_ewma_rate &&
+	    nla_put_u32(skb, TCA_POLICE_AVRATE, police->tcfp_ewma_rate))
+		goto nla_put_failure;
+	return skb->len;
+
+nla_put_failure:
+	nlmsg_trim(skb, b);
+	return -1;
+}
+
+MODULE_AUTHOR("Alexey Kuznetsov");
+MODULE_DESCRIPTION("Policing actions");
+MODULE_LICENSE("GPL");
+
+static struct tc_action_ops act_police_ops = {
+	.kind		=	"police",
+	.type		=	TCA_ID_POLICE,
+	.owner		=	THIS_MODULE,
+	.act		=	tcf_act_police,
+	.dump		=	tcf_act_police_dump,
+	.init		=	tcf_act_police_locate,
+	.walk		=	tcf_act_police_walker
+};
+
+static int __init
+police_init_module(void)
+{
+	return tcf_register_action(&act_police_ops, POL_TAB_MASK);
+}
+
+static void __exit
+police_cleanup_module(void)
+{
+	tcf_unregister_action(&act_police_ops);
+}
+
+module_init(police_init_module);
+module_exit(police_cleanup_module);