net/sched/act_police.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * net/sched/act_police.c       Input police filter
   4  *
   5  * Authors:     Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
   6  *              J Hadi Salim (action changes)
   7  */
   8
   9 #include <linux/module.h>
  10 #include <linux/types.h>
  11 #include <linux/kernel.h>
  12 #include <linux/string.h>
  13 #include <linux/errno.h>
  14 #include <linux/skbuff.h>
  15 #include <linux/rtnetlink.h>
  16 #include <linux/init.h>
  17 #include <linux/slab.h>
  18 #include <net/act_api.h>
  19 #include <net/netlink.h>
  20 #include <net/pkt_cls.h>
  21 #include <net/tc_act/tc_police.h>
  22
  23 /* Each policer is serialized by its individual spinlock */
  24
  25 static unsigned int police_net_id;
  26 static struct tc_action_ops act_police_ops;
  27
  28 static int tcf_police_walker(struct net *net, struct sk_buff *skb,
  29                                  struct netlink_callback *cb, int type,
  30                                  const struct tc_action_ops *ops,
  31                                  struct netlink_ext_ack *extack)
  32 {
  33         struct tc_action_net *tn = net_generic(net, police_net_id);
  34
  35         return tcf_generic_walker(tn, skb, cb, type, ops, extack);
  36 }
  37
  38 static const struct nla_policy police_policy[TCA_POLICE_MAX + 1] = {
  39         [TCA_POLICE_RATE]       = { .len = TC_RTAB_SIZE },
  40         [TCA_POLICE_PEAKRATE]   = { .len = TC_RTAB_SIZE },
  41         [TCA_POLICE_AVRATE]     = { .type = NLA_U32 },
  42         [TCA_POLICE_RESULT]     = { .type = NLA_U32 },
  43 };
  44
  45 static int tcf_police_init(struct net *net, struct nlattr *nla,
  46                                struct nlattr *est, struct tc_action **a,
  47                                int ovr, int bind, bool rtnl_held,
  48                                struct tcf_proto *tp,
  49                                struct netlink_ext_ack *extack)
  50 {
  51         int ret = 0, tcfp_result = TC_ACT_OK, err, size;
  52         struct nlattr *tb[TCA_POLICE_MAX + 1];
  53         struct tcf_chain *goto_ch = NULL;
  54         struct tc_police *parm;
  55         struct tcf_police *police;
  56         struct qdisc_rate_table *R_tab = NULL, *P_tab = NULL;
  57         struct tc_action_net *tn = net_generic(net, police_net_id);
  58         struct tcf_police_params *new;
  59         bool exists = false;
  60
  61         if (nla == NULL)
  62                 return -EINVAL;
  63
  64         err = nla_parse_nested_deprecated(tb, TCA_POLICE_MAX, nla,
  65                                           police_policy, NULL);
  66         if (err < 0)
  67                 return err;
  68
  69         if (tb[TCA_POLICE_TBF] == NULL)
  70                 return -EINVAL;
  71         size = nla_len(tb[TCA_POLICE_TBF]);
  72         if (size != sizeof(*parm) && size != sizeof(struct tc_police_compat))
  73                 return -EINVAL;
  74
  75         parm = nla_data(tb[TCA_POLICE_TBF]);
  76         err = tcf_idr_check_alloc(tn, &parm->index, a, bind);
  77         if (err < 0)
  78                 return err;
  79         exists = err;
  80         if (exists && bind)
  81                 return 0;
  82
  83         if (!exists) {
  84                 ret = tcf_idr_create(tn, parm->index, NULL, a,
  85                                      &act_police_ops, bind, true);
  86                 if (ret) {
  87                         tcf_idr_cleanup(tn, parm->index);
  88                         return ret;
  89                 }
  90                 ret = ACT_P_CREATED;
  91                 spin_lock_init(&(to_police(*a)->tcfp_lock));
  92         } else if (!ovr) {
  93                 tcf_idr_release(*a, bind);
  94                 return -EEXIST;
  95         }
  96         err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
  97         if (err < 0)
  98                 goto release_idr;
  99
 100         police = to_police(*a);
 101         if (parm->rate.rate) {
 102                 err = -ENOMEM;
 103                 R_tab = qdisc_get_rtab(&parm->rate, tb[TCA_POLICE_RATE], NULL);
 104                 if (R_tab == NULL)
 105                         goto failure;
 106
 107                 if (parm->peakrate.rate) {
 108                         P_tab = qdisc_get_rtab(&parm->peakrate,
 109                                                tb[TCA_POLICE_PEAKRATE], NULL);
 110                         if (P_tab == NULL)
 111                                 goto failure;
 112                 }
 113         }
 114
 115         if (est) {
 116                 err = gen_replace_estimator(&police->tcf_bstats,
 117                                             police->common.cpu_bstats,
 118                                             &police->tcf_rate_est,
 119                                             &police->tcf_lock,
 120                                             NULL, est);
 121                 if (err)
 122                         goto failure;
 123         } else if (tb[TCA_POLICE_AVRATE] &&
 124                    (ret == ACT_P_CREATED ||
 125                     !gen_estimator_active(&police->tcf_rate_est))) {
 126                 err = -EINVAL;
 127                 goto failure;
 128         }
 129
 130         if (tb[TCA_POLICE_RESULT]) {
 131                 tcfp_result = nla_get_u32(tb[TCA_POLICE_RESULT]);
 132                 if (TC_ACT_EXT_CMP(tcfp_result, TC_ACT_GOTO_CHAIN)) {
 133                         NL_SET_ERR_MSG(extack,
 134                                        "goto chain not allowed on fallback");
 135                         err = -EINVAL;
 136                         goto failure;
 137                 }
 138         }
 139
 140         new = kzalloc(sizeof(*new), GFP_KERNEL);
 141         if (unlikely(!new)) {
 142                 err = -ENOMEM;
 143                 goto failure;
 144         }
 145
 146         /* No failure allowed after this point */
 147         new->tcfp_result = tcfp_result;
 148         new->tcfp_mtu = parm->mtu;
 149         if (!new->tcfp_mtu) {
 150                 new->tcfp_mtu = ~0;
 151                 if (R_tab)
 152                         new->tcfp_mtu = 255 << R_tab->rate.cell_log;
 153         }
 154         if (R_tab) {
 155                 new->rate_present = true;
 156                 psched_ratecfg_precompute(&new->rate, &R_tab->rate, 0);
 157                 qdisc_put_rtab(R_tab);
 158         } else {
 159                 new->rate_present = false;
 160         }
 161         if (P_tab) {
 162                 new->peak_present = true;
 163                 psched_ratecfg_precompute(&new->peak, &P_tab->rate, 0);
 164                 qdisc_put_rtab(P_tab);
 165         } else {
 166                 new->peak_present = false;
 167         }
 168
 169         new->tcfp_burst = PSCHED_TICKS2NS(parm->burst);
 170         if (new->peak_present)
 171                 new->tcfp_mtu_ptoks = (s64)psched_l2t_ns(&new->peak,
 172                                                          new->tcfp_mtu);
 173
 174         if (tb[TCA_POLICE_AVRATE])
 175                 new->tcfp_ewma_rate = nla_get_u32(tb[TCA_POLICE_AVRATE]);
 176
 177         spin_lock_bh(&police->tcf_lock);
 178         spin_lock_bh(&police->tcfp_lock);
 179         police->tcfp_t_c = ktime_get_ns();
 180         police->tcfp_toks = new->tcfp_burst;
 181         if (new->peak_present)
 182                 police->tcfp_ptoks = new->tcfp_mtu_ptoks;
 183         spin_unlock_bh(&police->tcfp_lock);
 184         goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
 185         rcu_swap_protected(police->params,
 186                            new,
 187                            lockdep_is_held(&police->tcf_lock));
 188         spin_unlock_bh(&police->tcf_lock);
 189
 190         if (goto_ch)
 191                 tcf_chain_put_by_act(goto_ch);
 192         if (new)
 193                 kfree_rcu(new, rcu);
 194
 195         if (ret == ACT_P_CREATED)
 196                 tcf_idr_insert(tn, *a);
 197         return ret;
 198
 199 failure:
 200         qdisc_put_rtab(P_tab);
 201         qdisc_put_rtab(R_tab);
 202         if (goto_ch)
 203                 tcf_chain_put_by_act(goto_ch);
 204 release_idr:
 205         tcf_idr_release(*a, bind);
 206         return err;
 207 }
 208
 209 static int tcf_police_act(struct sk_buff *skb, const struct tc_action *a,
 210                           struct tcf_result *res)
 211 {
 212         struct tcf_police *police = to_police(a);
 213         struct tcf_police_params *p;
 214         s64 now, toks, ptoks = 0;
 215         int ret;
 216
 217         tcf_lastuse_update(&police->tcf_tm);
 218         bstats_cpu_update(this_cpu_ptr(police->common.cpu_bstats), skb);
 219
 220         ret = READ_ONCE(police->tcf_action);
 221         p = rcu_dereference_bh(police->params);
 222
 223         if (p->tcfp_ewma_rate) {
 224                 struct gnet_stats_rate_est64 sample;
 225
 226                 if (!gen_estimator_read(&police->tcf_rate_est, &sample) ||
 227                     sample.bps >= p->tcfp_ewma_rate)
 228                         goto inc_overlimits;
 229         }
 230
 231         if (qdisc_pkt_len(skb) <= p->tcfp_mtu) {
 232                 if (!p->rate_present) {
 233                         ret = p->tcfp_result;
 234                         goto end;
 235                 }
 236
 237                 now = ktime_get_ns();
 238                 spin_lock_bh(&police->tcfp_lock);
 239                 toks = min_t(s64, now - police->tcfp_t_c, p->tcfp_burst);
 240                 if (p->peak_present) {
 241                         ptoks = toks + police->tcfp_ptoks;
 242                         if (ptoks > p->tcfp_mtu_ptoks)
 243                                 ptoks = p->tcfp_mtu_ptoks;
 244                         ptoks -= (s64)psched_l2t_ns(&p->peak,
 245                                                     qdisc_pkt_len(skb));
 246                 }
 247                 toks += police->tcfp_toks;
 248                 if (toks > p->tcfp_burst)
 249                         toks = p->tcfp_burst;
 250                 toks -= (s64)psched_l2t_ns(&p->rate, qdisc_pkt_len(skb));
 251                 if ((toks|ptoks) >= 0) {
 252                         police->tcfp_t_c = now;
 253                         police->tcfp_toks = toks;
 254                         police->tcfp_ptoks = ptoks;
 255                         spin_unlock_bh(&police->tcfp_lock);
 256                         ret = p->tcfp_result;
 257                         goto inc_drops;
 258                 }
 259                 spin_unlock_bh(&police->tcfp_lock);
 260         }
 261
 262 inc_overlimits:
 263         qstats_overlimit_inc(this_cpu_ptr(police->common.cpu_qstats));
 264 inc_drops:
 265         if (ret == TC_ACT_SHOT)
 266                 qstats_drop_inc(this_cpu_ptr(police->common.cpu_qstats));
 267 end:
 268         return ret;
 269 }
 270
 271 static void tcf_police_cleanup(struct tc_action *a)
 272 {
 273         struct tcf_police *police = to_police(a);
 274         struct tcf_police_params *p;
 275
 276         p = rcu_dereference_protected(police->params, 1);
 277         if (p)
 278                 kfree_rcu(p, rcu);
 279 }
 280
 281 static void tcf_police_stats_update(struct tc_action *a,
 282                                     u64 bytes, u32 packets,
 283                                     u64 lastuse, bool hw)
 284 {
 285         struct tcf_police *police = to_police(a);
 286         struct tcf_t *tm = &police->tcf_tm;
 287
 288         _bstats_cpu_update(this_cpu_ptr(a->cpu_bstats), bytes, packets);
 289         if (hw)
 290                 _bstats_cpu_update(this_cpu_ptr(a->cpu_bstats_hw),
 291                                    bytes, packets);
 292         tm->lastuse = max_t(u64, tm->lastuse, lastuse);
 293 }
 294
 295 static int tcf_police_dump(struct sk_buff *skb, struct tc_action *a,
 296                                int bind, int ref)
 297 {
 298         unsigned char *b = skb_tail_pointer(skb);
 299         struct tcf_police *police = to_police(a);
 300         struct tcf_police_params *p;
 301         struct tc_police opt = {
 302                 .index = police->tcf_index,
 303                 .refcnt = refcount_read(&police->tcf_refcnt) - ref,
 304                 .bindcnt = atomic_read(&police->tcf_bindcnt) - bind,
 305         };
 306         struct tcf_t t;
 307
 308         spin_lock_bh(&police->tcf_lock);
 309         opt.action = police->tcf_action;
 310         p = rcu_dereference_protected(police->params,
 311                                       lockdep_is_held(&police->tcf_lock));
 312         opt.mtu = p->tcfp_mtu;
 313         opt.burst = PSCHED_NS2TICKS(p->tcfp_burst);
 314         if (p->rate_present)
 315                 psched_ratecfg_getrate(&opt.rate, &p->rate);
 316         if (p->peak_present)
 317                 psched_ratecfg_getrate(&opt.peakrate, &p->peak);
 318         if (nla_put(skb, TCA_POLICE_TBF, sizeof(opt), &opt))
 319                 goto nla_put_failure;
 320         if (p->tcfp_result &&
 321             nla_put_u32(skb, TCA_POLICE_RESULT, p->tcfp_result))
 322                 goto nla_put_failure;
 323         if (p->tcfp_ewma_rate &&
 324             nla_put_u32(skb, TCA_POLICE_AVRATE, p->tcfp_ewma_rate))
 325                 goto nla_put_failure;
 326
 327         t.install = jiffies_to_clock_t(jiffies - police->tcf_tm.install);
 328         t.lastuse = jiffies_to_clock_t(jiffies - police->tcf_tm.lastuse);
 329         t.firstuse = jiffies_to_clock_t(jiffies - police->tcf_tm.firstuse);
 330         t.expires = jiffies_to_clock_t(police->tcf_tm.expires);
 331         if (nla_put_64bit(skb, TCA_POLICE_TM, sizeof(t), &t, TCA_POLICE_PAD))
 332                 goto nla_put_failure;
 333         spin_unlock_bh(&police->tcf_lock);
 334
 335         return skb->len;
 336
 337 nla_put_failure:
 338         spin_unlock_bh(&police->tcf_lock);
 339         nlmsg_trim(skb, b);
 340         return -1;
 341 }
 342
 343 static int tcf_police_search(struct net *net, struct tc_action **a, u32 index)
 344 {
 345         struct tc_action_net *tn = net_generic(net, police_net_id);
 346
 347         return tcf_idr_search(tn, a, index);
 348 }
 349
 350 MODULE_AUTHOR("Alexey Kuznetsov");
 351 MODULE_DESCRIPTION("Policing actions");
 352 MODULE_LICENSE("GPL");
 353
 354 static struct tc_action_ops act_police_ops = {
 355         .kind           =       "police",
 356         .id             =       TCA_ID_POLICE,
 357         .owner          =       THIS_MODULE,
 358         .stats_update   =       tcf_police_stats_update,
 359         .act            =       tcf_police_act,
 360         .dump           =       tcf_police_dump,
 361         .init           =       tcf_police_init,
 362         .walk           =       tcf_police_walker,
 363         .lookup         =       tcf_police_search,
 364         .cleanup        =       tcf_police_cleanup,
 365         .size           =       sizeof(struct tcf_police),
 366 };
 367
 368 static __net_init int police_init_net(struct net *net)
 369 {
 370         struct tc_action_net *tn = net_generic(net, police_net_id);
 371
 372         return tc_action_net_init(tn, &act_police_ops);
 373 }
 374
 375 static void __net_exit police_exit_net(struct list_head *net_list)
 376 {
 377         tc_action_net_exit(net_list, police_net_id);
 378 }
 379
 380 static struct pernet_operations police_net_ops = {
 381         .init = police_init_net,
 382         .exit_batch = police_exit_net,
 383         .id   = &police_net_id,
 384         .size = sizeof(struct tc_action_net),
 385 };
 386
 387 static int __init police_init_module(void)
 388 {
 389         return tcf_register_action(&act_police_ops, &police_net_ops);
 390 }
 391
 392 static void __exit police_cleanup_module(void)
 393 {
 394         tcf_unregister_action(&act_police_ops, &police_net_ops);
 395 }
 396
 397 module_init(police_init_module);
 398 module_exit(police_cleanup_module);