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         [TCA_POLICE_RATE64]     = { .type = NLA_U64 },
  44         [TCA_POLICE_PEAKRATE64] = { .type = NLA_U64 },
  45         [TCA_POLICE_PKTRATE64]  = { .type = NLA_U64, .min = 1 },
  46         [TCA_POLICE_PKTBURST64] = { .type = NLA_U64, .min = 1 },
  47 };
  48
  49 static int tcf_police_init(struct net *net, struct nlattr *nla,
  50                                struct nlattr *est, struct tc_action **a,
  51                                struct tcf_proto *tp, u32 flags,
  52                                struct netlink_ext_ack *extack)
  53 {
  54         int ret = 0, tcfp_result = TC_ACT_OK, err, size;
  55         bool bind = flags & TCA_ACT_FLAGS_BIND;
  56         struct nlattr *tb[TCA_POLICE_MAX + 1];
  57         struct tcf_chain *goto_ch = NULL;
  58         struct tc_police *parm;
  59         struct tcf_police *police;
  60         struct qdisc_rate_table *R_tab = NULL, *P_tab = NULL;
  61         struct tc_action_net *tn = net_generic(net, police_net_id);
  62         struct tcf_police_params *new;
  63         bool exists = false;
  64         u32 index;
  65         u64 rate64, prate64;
  66         u64 pps, ppsburst;
  67
  68         if (nla == NULL)
  69                 return -EINVAL;
  70
  71         err = nla_parse_nested_deprecated(tb, TCA_POLICE_MAX, nla,
  72                                           police_policy, NULL);
  73         if (err < 0)
  74                 return err;
  75
  76         if (tb[TCA_POLICE_TBF] == NULL)
  77                 return -EINVAL;
  78         size = nla_len(tb[TCA_POLICE_TBF]);
  79         if (size != sizeof(*parm) && size != sizeof(struct tc_police_compat))
  80                 return -EINVAL;
  81
  82         parm = nla_data(tb[TCA_POLICE_TBF]);
  83         index = parm->index;
  84         err = tcf_idr_check_alloc(tn, &index, a, bind);
  85         if (err < 0)
  86                 return err;
  87         exists = err;
  88         if (exists && bind)
  89                 return 0;
  90
  91         if (!exists) {
  92                 ret = tcf_idr_create(tn, index, NULL, a,
  93                                      &act_police_ops, bind, true, 0);
  94                 if (ret) {
  95                         tcf_idr_cleanup(tn, index);
  96                         return ret;
  97                 }
  98                 ret = ACT_P_CREATED;
  99                 spin_lock_init(&(to_police(*a)->tcfp_lock));
 100         } else if (!(flags & TCA_ACT_FLAGS_REPLACE)) {
 101                 tcf_idr_release(*a, bind);
 102                 return -EEXIST;
 103         }
 104         err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
 105         if (err < 0)
 106                 goto release_idr;
 107
 108         police = to_police(*a);
 109         if (parm->rate.rate) {
 110                 err = -ENOMEM;
 111                 R_tab = qdisc_get_rtab(&parm->rate, tb[TCA_POLICE_RATE], NULL);
 112                 if (R_tab == NULL)
 113                         goto failure;
 114
 115                 if (parm->peakrate.rate) {
 116                         P_tab = qdisc_get_rtab(&parm->peakrate,
 117                                                tb[TCA_POLICE_PEAKRATE], NULL);
 118                         if (P_tab == NULL)
 119                                 goto failure;
 120                 }
 121         }
 122
 123         if (est) {
 124                 err = gen_replace_estimator(&police->tcf_bstats,
 125                                             police->common.cpu_bstats,
 126                                             &police->tcf_rate_est,
 127                                             &police->tcf_lock,
 128                                             NULL, est);
 129                 if (err)
 130                         goto failure;
 131         } else if (tb[TCA_POLICE_AVRATE] &&
 132                    (ret == ACT_P_CREATED ||
 133                     !gen_estimator_active(&police->tcf_rate_est))) {
 134                 err = -EINVAL;
 135                 goto failure;
 136         }
 137
 138         if (tb[TCA_POLICE_RESULT]) {
 139                 tcfp_result = nla_get_u32(tb[TCA_POLICE_RESULT]);
 140                 if (TC_ACT_EXT_CMP(tcfp_result, TC_ACT_GOTO_CHAIN)) {
 141                         NL_SET_ERR_MSG(extack,
 142                                        "goto chain not allowed on fallback");
 143                         err = -EINVAL;
 144                         goto failure;
 145                 }
 146         }
 147
 148         if ((tb[TCA_POLICE_PKTRATE64] && !tb[TCA_POLICE_PKTBURST64]) ||
 149             (!tb[TCA_POLICE_PKTRATE64] && tb[TCA_POLICE_PKTBURST64])) {
 150                 NL_SET_ERR_MSG(extack,
 151                                "Both or neither packet-per-second burst and rate must be provided");
 152                 err = -EINVAL;
 153                 goto failure;
 154         }
 155
 156         if (tb[TCA_POLICE_PKTRATE64] && R_tab) {
 157                 NL_SET_ERR_MSG(extack,
 158                                "packet-per-second and byte-per-second rate limits not allowed in same action");
 159                 err = -EINVAL;
 160                 goto failure;
 161         }
 162
 163         new = kzalloc(sizeof(*new), GFP_KERNEL);
 164         if (unlikely(!new)) {
 165                 err = -ENOMEM;
 166                 goto failure;
 167         }
 168
 169         /* No failure allowed after this point */
 170         new->tcfp_result = tcfp_result;
 171         new->tcfp_mtu = parm->mtu;
 172         if (!new->tcfp_mtu) {
 173                 new->tcfp_mtu = ~0;
 174                 if (R_tab)
 175                         new->tcfp_mtu = 255 << R_tab->rate.cell_log;
 176         }
 177         if (R_tab) {
 178                 new->rate_present = true;
 179                 rate64 = tb[TCA_POLICE_RATE64] ?
 180                          nla_get_u64(tb[TCA_POLICE_RATE64]) : 0;
 181                 psched_ratecfg_precompute(&new->rate, &R_tab->rate, rate64);
 182                 qdisc_put_rtab(R_tab);
 183         } else {
 184                 new->rate_present = false;
 185         }
 186         if (P_tab) {
 187                 new->peak_present = true;
 188                 prate64 = tb[TCA_POLICE_PEAKRATE64] ?
 189                           nla_get_u64(tb[TCA_POLICE_PEAKRATE64]) : 0;
 190                 psched_ratecfg_precompute(&new->peak, &P_tab->rate, prate64);
 191                 qdisc_put_rtab(P_tab);
 192         } else {
 193                 new->peak_present = false;
 194         }
 195
 196         new->tcfp_burst = PSCHED_TICKS2NS(parm->burst);
 197         if (new->peak_present)
 198                 new->tcfp_mtu_ptoks = (s64)psched_l2t_ns(&new->peak,
 199                                                          new->tcfp_mtu);
 200
 201         if (tb[TCA_POLICE_AVRATE])
 202                 new->tcfp_ewma_rate = nla_get_u32(tb[TCA_POLICE_AVRATE]);
 203
 204         if (tb[TCA_POLICE_PKTRATE64]) {
 205                 pps = nla_get_u64(tb[TCA_POLICE_PKTRATE64]);
 206                 ppsburst = nla_get_u64(tb[TCA_POLICE_PKTBURST64]);
 207                 new->pps_present = true;
 208                 new->tcfp_pkt_burst = PSCHED_TICKS2NS(ppsburst);
 209                 psched_ppscfg_precompute(&new->ppsrate, pps);
 210         }
 211
 212         spin_lock_bh(&police->tcf_lock);
 213         spin_lock_bh(&police->tcfp_lock);
 214         police->tcfp_t_c = ktime_get_ns();
 215         police->tcfp_toks = new->tcfp_burst;
 216         if (new->peak_present)
 217                 police->tcfp_ptoks = new->tcfp_mtu_ptoks;
 218         spin_unlock_bh(&police->tcfp_lock);
 219         goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
 220         new = rcu_replace_pointer(police->params,
 221                                   new,
 222                                   lockdep_is_held(&police->tcf_lock));
 223         spin_unlock_bh(&police->tcf_lock);
 224
 225         if (goto_ch)
 226                 tcf_chain_put_by_act(goto_ch);
 227         if (new)
 228                 kfree_rcu(new, rcu);
 229
 230         return ret;
 231
 232 failure:
 233         qdisc_put_rtab(P_tab);
 234         qdisc_put_rtab(R_tab);
 235         if (goto_ch)
 236                 tcf_chain_put_by_act(goto_ch);
 237 release_idr:
 238         tcf_idr_release(*a, bind);
 239         return err;
 240 }
 241
 242 static int tcf_police_act(struct sk_buff *skb, const struct tc_action *a,
 243                           struct tcf_result *res)
 244 {
 245         struct tcf_police *police = to_police(a);
 246         s64 now, toks, ppstoks = 0, ptoks = 0;
 247         struct tcf_police_params *p;
 248         int ret;
 249
 250         tcf_lastuse_update(&police->tcf_tm);
 251         bstats_cpu_update(this_cpu_ptr(police->common.cpu_bstats), skb);
 252
 253         ret = READ_ONCE(police->tcf_action);
 254         p = rcu_dereference_bh(police->params);
 255
 256         if (p->tcfp_ewma_rate) {
 257                 struct gnet_stats_rate_est64 sample;
 258
 259                 if (!gen_estimator_read(&police->tcf_rate_est, &sample) ||
 260                     sample.bps >= p->tcfp_ewma_rate)
 261                         goto inc_overlimits;
 262         }
 263
 264         if (qdisc_pkt_len(skb) <= p->tcfp_mtu) {
 265                 if (!p->rate_present && !p->pps_present) {
 266                         ret = p->tcfp_result;
 267                         goto end;
 268                 }
 269
 270                 now = ktime_get_ns();
 271                 spin_lock_bh(&police->tcfp_lock);
 272                 toks = min_t(s64, now - police->tcfp_t_c, p->tcfp_burst);
 273                 if (p->peak_present) {
 274                         ptoks = toks + police->tcfp_ptoks;
 275                         if (ptoks > p->tcfp_mtu_ptoks)
 276                                 ptoks = p->tcfp_mtu_ptoks;
 277                         ptoks -= (s64)psched_l2t_ns(&p->peak,
 278                                                     qdisc_pkt_len(skb));
 279                 }
 280                 if (p->rate_present) {
 281                         toks += police->tcfp_toks;
 282                         if (toks > p->tcfp_burst)
 283                                 toks = p->tcfp_burst;
 284                         toks -= (s64)psched_l2t_ns(&p->rate, qdisc_pkt_len(skb));
 285                 } else if (p->pps_present) {
 286                         ppstoks = min_t(s64, now - police->tcfp_t_c, p->tcfp_pkt_burst);
 287                         ppstoks += police->tcfp_pkttoks;
 288                         if (ppstoks > p->tcfp_pkt_burst)
 289                                 ppstoks = p->tcfp_pkt_burst;
 290                         ppstoks -= (s64)psched_pkt2t_ns(&p->ppsrate, 1);
 291                 }
 292                 if ((toks | ptoks | ppstoks) >= 0) {
 293                         police->tcfp_t_c = now;
 294                         police->tcfp_toks = toks;
 295                         police->tcfp_ptoks = ptoks;
 296                         police->tcfp_pkttoks = ppstoks;
 297                         spin_unlock_bh(&police->tcfp_lock);
 298                         ret = p->tcfp_result;
 299                         goto inc_drops;
 300                 }
 301                 spin_unlock_bh(&police->tcfp_lock);
 302         }
 303
 304 inc_overlimits:
 305         qstats_overlimit_inc(this_cpu_ptr(police->common.cpu_qstats));
 306 inc_drops:
 307         if (ret == TC_ACT_SHOT)
 308                 qstats_drop_inc(this_cpu_ptr(police->common.cpu_qstats));
 309 end:
 310         return ret;
 311 }
 312
 313 static void tcf_police_cleanup(struct tc_action *a)
 314 {
 315         struct tcf_police *police = to_police(a);
 316         struct tcf_police_params *p;
 317
 318         p = rcu_dereference_protected(police->params, 1);
 319         if (p)
 320                 kfree_rcu(p, rcu);
 321 }
 322
 323 static void tcf_police_stats_update(struct tc_action *a,
 324                                     u64 bytes, u64 packets, u64 drops,
 325                                     u64 lastuse, bool hw)
 326 {
 327         struct tcf_police *police = to_police(a);
 328         struct tcf_t *tm = &police->tcf_tm;
 329
 330         tcf_action_update_stats(a, bytes, packets, drops, hw);
 331         tm->lastuse = max_t(u64, tm->lastuse, lastuse);
 332 }
 333
 334 static int tcf_police_dump(struct sk_buff *skb, struct tc_action *a,
 335                                int bind, int ref)
 336 {
 337         unsigned char *b = skb_tail_pointer(skb);
 338         struct tcf_police *police = to_police(a);
 339         struct tcf_police_params *p;
 340         struct tc_police opt = {
 341                 .index = police->tcf_index,
 342                 .refcnt = refcount_read(&police->tcf_refcnt) - ref,
 343                 .bindcnt = atomic_read(&police->tcf_bindcnt) - bind,
 344         };
 345         struct tcf_t t;
 346
 347         spin_lock_bh(&police->tcf_lock);
 348         opt.action = police->tcf_action;
 349         p = rcu_dereference_protected(police->params,
 350                                       lockdep_is_held(&police->tcf_lock));
 351         opt.mtu = p->tcfp_mtu;
 352         opt.burst = PSCHED_NS2TICKS(p->tcfp_burst);
 353         if (p->rate_present) {
 354                 psched_ratecfg_getrate(&opt.rate, &p->rate);
 355                 if ((police->params->rate.rate_bytes_ps >= (1ULL << 32)) &&
 356                     nla_put_u64_64bit(skb, TCA_POLICE_RATE64,
 357                                       police->params->rate.rate_bytes_ps,
 358                                       TCA_POLICE_PAD))
 359                         goto nla_put_failure;
 360         }
 361         if (p->peak_present) {
 362                 psched_ratecfg_getrate(&opt.peakrate, &p->peak);
 363                 if ((police->params->peak.rate_bytes_ps >= (1ULL << 32)) &&
 364                     nla_put_u64_64bit(skb, TCA_POLICE_PEAKRATE64,
 365                                       police->params->peak.rate_bytes_ps,
 366                                       TCA_POLICE_PAD))
 367                         goto nla_put_failure;
 368         }
 369         if (p->pps_present) {
 370                 if (nla_put_u64_64bit(skb, TCA_POLICE_PKTRATE64,
 371                                       police->params->ppsrate.rate_pkts_ps,
 372                                       TCA_POLICE_PAD))
 373                         goto nla_put_failure;
 374                 if (nla_put_u64_64bit(skb, TCA_POLICE_PKTBURST64,
 375                                       PSCHED_NS2TICKS(p->tcfp_pkt_burst),
 376                                       TCA_POLICE_PAD))
 377                         goto nla_put_failure;
 378         }
 379         if (nla_put(skb, TCA_POLICE_TBF, sizeof(opt), &opt))
 380                 goto nla_put_failure;
 381         if (p->tcfp_result &&
 382             nla_put_u32(skb, TCA_POLICE_RESULT, p->tcfp_result))
 383                 goto nla_put_failure;
 384         if (p->tcfp_ewma_rate &&
 385             nla_put_u32(skb, TCA_POLICE_AVRATE, p->tcfp_ewma_rate))
 386                 goto nla_put_failure;
 387
 388         tcf_tm_dump(&t, &police->tcf_tm);
 389         if (nla_put_64bit(skb, TCA_POLICE_TM, sizeof(t), &t, TCA_POLICE_PAD))
 390                 goto nla_put_failure;
 391         spin_unlock_bh(&police->tcf_lock);
 392
 393         return skb->len;
 394
 395 nla_put_failure:
 396         spin_unlock_bh(&police->tcf_lock);
 397         nlmsg_trim(skb, b);
 398         return -1;
 399 }
 400
 401 static int tcf_police_search(struct net *net, struct tc_action **a, u32 index)
 402 {
 403         struct tc_action_net *tn = net_generic(net, police_net_id);
 404
 405         return tcf_idr_search(tn, a, index);
 406 }
 407
 408 MODULE_AUTHOR("Alexey Kuznetsov");
 409 MODULE_DESCRIPTION("Policing actions");
 410 MODULE_LICENSE("GPL");
 411
 412 static struct tc_action_ops act_police_ops = {
 413         .kind           =       "police",
 414         .id             =       TCA_ID_POLICE,
 415         .owner          =       THIS_MODULE,
 416         .stats_update   =       tcf_police_stats_update,
 417         .act            =       tcf_police_act,
 418         .dump           =       tcf_police_dump,
 419         .init           =       tcf_police_init,
 420         .walk           =       tcf_police_walker,
 421         .lookup         =       tcf_police_search,
 422         .cleanup        =       tcf_police_cleanup,
 423         .size           =       sizeof(struct tcf_police),
 424 };
 425
 426 static __net_init int police_init_net(struct net *net)
 427 {
 428         struct tc_action_net *tn = net_generic(net, police_net_id);
 429
 430         return tc_action_net_init(net, tn, &act_police_ops);
 431 }
 432
 433 static void __net_exit police_exit_net(struct list_head *net_list)
 434 {
 435         tc_action_net_exit(net_list, police_net_id);
 436 }
 437
 438 static struct pernet_operations police_net_ops = {
 439         .init = police_init_net,
 440         .exit_batch = police_exit_net,
 441         .id   = &police_net_id,
 442         .size = sizeof(struct tc_action_net),
 443 };
 444
 445 static int __init police_init_module(void)
 446 {
 447         return tcf_register_action(&act_police_ops, &police_net_ops);
 448 }
 449
 450 static void __exit police_cleanup_module(void)
 451 {
 452         tcf_unregister_action(&act_police_ops, &police_net_ops);
 453 }
 454
 455 module_init(police_init_module);
 456 module_exit(police_cleanup_module);