// SPDX-License-Identifier: GPL-2.0-or-later /* * net/sched/act_police.c Input police filter * * 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> #include <net/pkt_cls.h> #include <net/tc_act/tc_police.h> /* Each policer is serialized by its individual spinlock */ static unsigned int police_net_id; static struct tc_action_ops act_police_ops; static int tcf_police_walker(struct net *net, struct sk_buff *skb, struct netlink_callback *cb, int type, const struct tc_action_ops *ops, struct netlink_ext_ack *extack) { struct tc_action_net *tn = net_generic(net, police_net_id); return tcf_generic_walker(tn, skb, cb, type, ops, extack); } 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 }, [TCA_POLICE_RATE64] = { .type = NLA_U64 }, [TCA_POLICE_PEAKRATE64] = { .type = NLA_U64 }, }; static int tcf_police_init(struct net *net, struct nlattr *nla, struct nlattr *est, struct tc_action **a, int ovr, int bind, bool rtnl_held, struct tcf_proto *tp, u32 flags, struct netlink_ext_ack *extack) { int ret = 0, tcfp_result = TC_ACT_OK, err, size; struct nlattr *tb[TCA_POLICE_MAX + 1]; struct tcf_chain *goto_ch = NULL; struct tc_police *parm; struct tcf_police *police; struct qdisc_rate_table *R_tab = NULL, *P_tab = NULL; struct tc_action_net *tn = net_generic(net, police_net_id); struct tcf_police_params *new; bool exists = false; u32 index; u64 rate64, prate64; if (nla == NULL) return -EINVAL; err = nla_parse_nested_deprecated(tb, TCA_POLICE_MAX, nla, police_policy, NULL); 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]); index = parm->index; err = tcf_idr_check_alloc(tn, &index, a, bind); if (err < 0) return err; exists = err; if (exists && bind) return 0; if (!exists) { ret = tcf_idr_create(tn, index, NULL, a, &act_police_ops, bind, true, 0); if (ret) { tcf_idr_cleanup(tn, index); return ret; } ret = ACT_P_CREATED; spin_lock_init(&(to_police(*a)->tcfp_lock)); } else if (!ovr) { tcf_idr_release(*a, bind); return -EEXIST; } err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack); if (err < 0) goto release_idr; police = to_police(*a); if (parm->rate.rate) { err = -ENOMEM; R_tab = qdisc_get_rtab(&parm->rate, tb[TCA_POLICE_RATE], NULL); if (R_tab == NULL) goto failure; if (parm->peakrate.rate) { P_tab = qdisc_get_rtab(&parm->peakrate, tb[TCA_POLICE_PEAKRATE], NULL); if (P_tab == NULL) goto failure; } } if (est) { err = gen_replace_estimator(&police->tcf_bstats, police->common.cpu_bstats, &police->tcf_rate_est, &police->tcf_lock, NULL, est); if (err) goto failure; } else if (tb[TCA_POLICE_AVRATE] && (ret == ACT_P_CREATED || !gen_estimator_active(&police->tcf_rate_est))) { err = -EINVAL; goto failure; } if (tb[TCA_POLICE_RESULT]) { tcfp_result = nla_get_u32(tb[TCA_POLICE_RESULT]); if (TC_ACT_EXT_CMP(tcfp_result, TC_ACT_GOTO_CHAIN)) { NL_SET_ERR_MSG(extack, "goto chain not allowed on fallback"); err = -EINVAL; goto failure; } } new = kzalloc(sizeof(*new), GFP_KERNEL); if (unlikely(!new)) { err = -ENOMEM; goto failure; } /* No failure allowed after this point */ new->tcfp_result = tcfp_result; new->tcfp_mtu = parm->mtu; if (!new->tcfp_mtu) { new->tcfp_mtu = ~0; if (R_tab) new->tcfp_mtu = 255 << R_tab->rate.cell_log; } if (R_tab) { new->rate_present = true; rate64 = tb[TCA_POLICE_RATE64] ? nla_get_u64(tb[TCA_POLICE_RATE64]) : 0; psched_ratecfg_precompute(&new->rate, &R_tab->rate, rate64); qdisc_put_rtab(R_tab); } else { new->rate_present = false; } if (P_tab) { new->peak_present = true; prate64 = tb[TCA_POLICE_PEAKRATE64] ? nla_get_u64(tb[TCA_POLICE_PEAKRATE64]) : 0; psched_ratecfg_precompute(&new->peak, &P_tab->rate, prate64); qdisc_put_rtab(P_tab); } else { new->peak_present = false; } new->tcfp_burst = PSCHED_TICKS2NS(parm->burst); if (new->peak_present) new->tcfp_mtu_ptoks = (s64)psched_l2t_ns(&new->peak, new->tcfp_mtu); if (tb[TCA_POLICE_AVRATE]) new->tcfp_ewma_rate = nla_get_u32(tb[TCA_POLICE_AVRATE]); spin_lock_bh(&police->tcf_lock); spin_lock_bh(&police->tcfp_lock); police->tcfp_t_c = ktime_get_ns(); police->tcfp_toks = new->tcfp_burst; if (new->peak_present) police->tcfp_ptoks = new->tcfp_mtu_ptoks; spin_unlock_bh(&police->tcfp_lock); goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch); new = rcu_replace_pointer(police->params, new, lockdep_is_held(&police->tcf_lock)); spin_unlock_bh(&police->tcf_lock); if (goto_ch) tcf_chain_put_by_act(goto_ch); if (new) kfree_rcu(new, rcu); return ret; failure: qdisc_put_rtab(P_tab); qdisc_put_rtab(R_tab); if (goto_ch) tcf_chain_put_by_act(goto_ch); release_idr: tcf_idr_release(*a, bind); return err; } static int tcf_police_act(struct sk_buff *skb, const struct tc_action *a, struct tcf_result *res) { struct tcf_police *police = to_police(a); struct tcf_police_params *p; s64 now, toks, ptoks = 0; int ret; tcf_lastuse_update(&police->tcf_tm); bstats_cpu_update(this_cpu_ptr(police->common.cpu_bstats), skb); ret = READ_ONCE(police->tcf_action); p = rcu_dereference_bh(police->params); if (p->tcfp_ewma_rate) { struct gnet_stats_rate_est64 sample; if (!gen_estimator_read(&police->tcf_rate_est, &sample) || sample.bps >= p->tcfp_ewma_rate) goto inc_overlimits; } if (qdisc_pkt_len(skb) <= p->tcfp_mtu) { if (!p->rate_present) { ret = p->tcfp_result; goto end; } now = ktime_get_ns(); spin_lock_bh(&police->tcfp_lock); toks = min_t(s64, now - police->tcfp_t_c, p->tcfp_burst); if (p->peak_present) { ptoks = toks + police->tcfp_ptoks; if (ptoks > p->tcfp_mtu_ptoks) ptoks = p->tcfp_mtu_ptoks; ptoks -= (s64)psched_l2t_ns(&p->peak, qdisc_pkt_len(skb)); } toks += police->tcfp_toks; if (toks > p->tcfp_burst) toks = p->tcfp_burst; toks -= (s64)psched_l2t_ns(&p->rate, qdisc_pkt_len(skb)); if ((toks|ptoks) >= 0) { police->tcfp_t_c = now; police->tcfp_toks = toks; police->tcfp_ptoks = ptoks; spin_unlock_bh(&police->tcfp_lock); ret = p->tcfp_result; goto inc_drops; } spin_unlock_bh(&police->tcfp_lock); } inc_overlimits: qstats_overlimit_inc(this_cpu_ptr(police->common.cpu_qstats)); inc_drops: if (ret == TC_ACT_SHOT) qstats_drop_inc(this_cpu_ptr(police->common.cpu_qstats)); end: return ret; } static void tcf_police_cleanup(struct tc_action *a) { struct tcf_police *police = to_police(a); struct tcf_police_params *p; p = rcu_dereference_protected(police->params, 1); if (p) kfree_rcu(p, rcu); } static void tcf_police_stats_update(struct tc_action *a, u64 bytes, u64 packets, u64 drops, u64 lastuse, bool hw) { struct tcf_police *police = to_police(a); struct tcf_t *tm = &police->tcf_tm; tcf_action_update_stats(a, bytes, packets, drops, hw); tm->lastuse = max_t(u64, tm->lastuse, lastuse); } static int tcf_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 = to_police(a); struct tcf_police_params *p; struct tc_police opt = { .index = police->tcf_index, .refcnt = refcount_read(&police->tcf_refcnt) - ref, .bindcnt = atomic_read(&police->tcf_bindcnt) - bind, }; struct tcf_t t; spin_lock_bh(&police->tcf_lock); opt.action = police->tcf_action; p = rcu_dereference_protected(police->params, lockdep_is_held(&police->tcf_lock)); opt.mtu = p->tcfp_mtu; opt.burst = PSCHED_NS2TICKS(p->tcfp_burst); if (p->rate_present) { psched_ratecfg_getrate(&opt.rate, &p->rate); if ((police->params->rate.rate_bytes_ps >= (1ULL << 32)) && nla_put_u64_64bit(skb, TCA_POLICE_RATE64, police->params->rate.rate_bytes_ps, TCA_POLICE_PAD)) goto nla_put_failure; } if (p->peak_present) { psched_ratecfg_getrate(&opt.peakrate, &p->peak); if ((police->params->peak.rate_bytes_ps >= (1ULL << 32)) && nla_put_u64_64bit(skb, TCA_POLICE_PEAKRATE64, police->params->peak.rate_bytes_ps, TCA_POLICE_PAD)) goto nla_put_failure; } if (nla_put(skb, TCA_POLICE_TBF, sizeof(opt), &opt)) goto nla_put_failure; if (p->tcfp_result && nla_put_u32(skb, TCA_POLICE_RESULT, p->tcfp_result)) goto nla_put_failure; if (p->tcfp_ewma_rate && nla_put_u32(skb, TCA_POLICE_AVRATE, p->tcfp_ewma_rate)) goto nla_put_failure; tcf_tm_dump(&t, &police->tcf_tm); if (nla_put_64bit(skb, TCA_POLICE_TM, sizeof(t), &t, TCA_POLICE_PAD)) goto nla_put_failure; spin_unlock_bh(&police->tcf_lock); return skb->len; nla_put_failure: spin_unlock_bh(&police->tcf_lock); nlmsg_trim(skb, b); return -1; } static int tcf_police_search(struct net *net, struct tc_action **a, u32 index) { struct tc_action_net *tn = net_generic(net, police_net_id); return tcf_idr_search(tn, a, index); } MODULE_AUTHOR("Alexey Kuznetsov"); MODULE_DESCRIPTION("Policing actions"); MODULE_LICENSE("GPL"); static struct tc_action_ops act_police_ops = { .kind = "police", .id = TCA_ID_POLICE, .owner = THIS_MODULE, .stats_update = tcf_police_stats_update, .act = tcf_police_act, .dump = tcf_police_dump, .init = tcf_police_init, .walk = tcf_police_walker, .lookup = tcf_police_search, .cleanup = tcf_police_cleanup, .size = sizeof(struct tcf_police), }; static __net_init int police_init_net(struct net *net) { struct tc_action_net *tn = net_generic(net, police_net_id); return tc_action_net_init(net, tn, &act_police_ops); } static void __net_exit police_exit_net(struct list_head *net_list) { tc_action_net_exit(net_list, police_net_id); } static struct pernet_operations police_net_ops = { .init = police_init_net, .exit_batch = police_exit_net, .id = &police_net_id, .size = sizeof(struct tc_action_net), }; static int __init police_init_module(void) { return tcf_register_action(&act_police_ops, &police_net_ops); } static void __exit police_cleanup_module(void) { tcf_unregister_action(&act_police_ops, &police_net_ops); } module_init(police_init_module); module_exit(police_cleanup_module);