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/gso.h>
  20 #include <net/netlink.h>
  21 #include <net/pkt_cls.h>
  22 #include <net/tc_act/tc_police.h>
  23 #include <net/tc_wrapper.h>
  24
  25 /* Each policer is serialized by its individual spinlock */
  26
  27 static struct tc_action_ops act_police_ops;
  28
  29 static const struct nla_policy police_policy[TCA_POLICE_MAX + 1] = {
  30         [TCA_POLICE_RATE]       = { .len = TC_RTAB_SIZE },
  31         [TCA_POLICE_PEAKRATE]   = { .len = TC_RTAB_SIZE },
  32         [TCA_POLICE_AVRATE]     = { .type = NLA_U32 },
  33         [TCA_POLICE_RESULT]     = { .type = NLA_U32 },
  34         [TCA_POLICE_RATE64]     = { .type = NLA_U64 },
  35         [TCA_POLICE_PEAKRATE64] = { .type = NLA_U64 },
  36         [TCA_POLICE_PKTRATE64]  = { .type = NLA_U64, .min = 1 },
  37         [TCA_POLICE_PKTBURST64] = { .type = NLA_U64, .min = 1 },
  38 };
  39
  40 static int tcf_police_init(struct net *net, struct nlattr *nla,
  41                                struct nlattr *est, struct tc_action **a,
  42                                struct tcf_proto *tp, u32 flags,
  43                                struct netlink_ext_ack *extack)
  44 {
  45         int ret = 0, tcfp_result = TC_ACT_OK, err, size;
  46         bool bind = flags & TCA_ACT_FLAGS_BIND;
  47         struct nlattr *tb[TCA_POLICE_MAX + 1];
  48         struct tcf_chain *goto_ch = NULL;
  49         struct tc_police *parm;
  50         struct tcf_police *police;
  51         struct qdisc_rate_table *R_tab = NULL, *P_tab = NULL;
  52         struct tc_action_net *tn = net_generic(net, act_police_ops.net_id);
  53         struct tcf_police_params *new;
  54         bool exists = false;
  55         u32 index;
  56         u64 rate64, prate64;
  57         u64 pps, ppsburst;
  58
  59         if (nla == NULL)
  60                 return -EINVAL;
  61
  62         err = nla_parse_nested_deprecated(tb, TCA_POLICE_MAX, nla,
  63                                           police_policy, NULL);
  64         if (err < 0)
  65                 return err;
  66
  67         if (tb[TCA_POLICE_TBF] == NULL)
  68                 return -EINVAL;
  69         size = nla_len(tb[TCA_POLICE_TBF]);
  70         if (size != sizeof(*parm) && size != sizeof(struct tc_police_compat))
  71                 return -EINVAL;
  72
  73         parm = nla_data(tb[TCA_POLICE_TBF]);
  74         index = parm->index;
  75         err = tcf_idr_check_alloc(tn, &index, a, bind);
  76         if (err < 0)
  77                 return err;
  78         exists = err;
  79         if (exists && bind)
  80                 return ACT_P_BOUND;
  81
  82         if (!exists) {
  83                 ret = tcf_idr_create(tn, index, NULL, a,
  84                                      &act_police_ops, bind, true, flags);
  85                 if (ret) {
  86                         tcf_idr_cleanup(tn, index);
  87                         return ret;
  88                 }
  89                 ret = ACT_P_CREATED;
  90                 spin_lock_init(&(to_police(*a)->tcfp_lock));
  91         } else if (!(flags & TCA_ACT_FLAGS_REPLACE)) {
  92                 tcf_idr_release(*a, bind);
  93                 return -EEXIST;
  94         }
  95         err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
  96         if (err < 0)
  97                 goto release_idr;
  98
  99         police = to_police(*a);
 100         if (parm->rate.rate) {
 101                 err = -ENOMEM;
 102                 R_tab = qdisc_get_rtab(&parm->rate, tb[TCA_POLICE_RATE], NULL);
 103                 if (R_tab == NULL)
 104                         goto failure;
 105
 106                 if (parm->peakrate.rate) {
 107                         P_tab = qdisc_get_rtab(&parm->peakrate,
 108                                                tb[TCA_POLICE_PEAKRATE], NULL);
 109                         if (P_tab == NULL)
 110                                 goto failure;
 111                 }
 112         }
 113
 114         if (est) {
 115                 err = gen_replace_estimator(&police->tcf_bstats,
 116                                             police->common.cpu_bstats,
 117                                             &police->tcf_rate_est,
 118                                             &police->tcf_lock,
 119                                             false, est);
 120                 if (err)
 121                         goto failure;
 122         } else if (tb[TCA_POLICE_AVRATE] &&
 123                    (ret == ACT_P_CREATED ||
 124                     !gen_estimator_active(&police->tcf_rate_est))) {
 125                 err = -EINVAL;
 126                 goto failure;
 127         }
 128
 129         if (tb[TCA_POLICE_RESULT]) {
 130                 tcfp_result = nla_get_u32(tb[TCA_POLICE_RESULT]);
 131                 if (TC_ACT_EXT_CMP(tcfp_result, TC_ACT_GOTO_CHAIN)) {
 132                         NL_SET_ERR_MSG(extack,
 133                                        "goto chain not allowed on fallback");
 134                         err = -EINVAL;
 135                         goto failure;
 136                 }
 137         }
 138
 139         if ((tb[TCA_POLICE_PKTRATE64] && !tb[TCA_POLICE_PKTBURST64]) ||
 140             (!tb[TCA_POLICE_PKTRATE64] && tb[TCA_POLICE_PKTBURST64])) {
 141                 NL_SET_ERR_MSG(extack,
 142                                "Both or neither packet-per-second burst and rate must be provided");
 143                 err = -EINVAL;
 144                 goto failure;
 145         }
 146
 147         if (tb[TCA_POLICE_PKTRATE64] && R_tab) {
 148                 NL_SET_ERR_MSG(extack,
 149                                "packet-per-second and byte-per-second rate limits not allowed in same action");
 150                 err = -EINVAL;
 151                 goto failure;
 152         }
 153
 154         new = kzalloc(sizeof(*new), GFP_KERNEL);
 155         if (unlikely(!new)) {
 156                 err = -ENOMEM;
 157                 goto failure;
 158         }
 159
 160         /* No failure allowed after this point */
 161         new->tcfp_result = tcfp_result;
 162         new->tcfp_mtu = parm->mtu;
 163         if (!new->tcfp_mtu) {
 164                 new->tcfp_mtu = ~0;
 165                 if (R_tab)
 166                         new->tcfp_mtu = 255 << R_tab->rate.cell_log;
 167         }
 168         if (R_tab) {
 169                 new->rate_present = true;
 170                 rate64 = tb[TCA_POLICE_RATE64] ?
 171                          nla_get_u64(tb[TCA_POLICE_RATE64]) : 0;
 172                 psched_ratecfg_precompute(&new->rate, &R_tab->rate, rate64);
 173                 qdisc_put_rtab(R_tab);
 174         } else {
 175                 new->rate_present = false;
 176         }
 177         if (P_tab) {
 178                 new->peak_present = true;
 179                 prate64 = tb[TCA_POLICE_PEAKRATE64] ?
 180                           nla_get_u64(tb[TCA_POLICE_PEAKRATE64]) : 0;
 181                 psched_ratecfg_precompute(&new->peak, &P_tab->rate, prate64);
 182                 qdisc_put_rtab(P_tab);
 183         } else {
 184                 new->peak_present = false;
 185         }
 186
 187         new->tcfp_burst = PSCHED_TICKS2NS(parm->burst);
 188         if (new->peak_present)
 189                 new->tcfp_mtu_ptoks = (s64)psched_l2t_ns(&new->peak,
 190                                                          new->tcfp_mtu);
 191
 192         if (tb[TCA_POLICE_AVRATE])
 193                 new->tcfp_ewma_rate = nla_get_u32(tb[TCA_POLICE_AVRATE]);
 194
 195         if (tb[TCA_POLICE_PKTRATE64]) {
 196                 pps = nla_get_u64(tb[TCA_POLICE_PKTRATE64]);
 197                 ppsburst = nla_get_u64(tb[TCA_POLICE_PKTBURST64]);
 198                 new->pps_present = true;
 199                 new->tcfp_pkt_burst = PSCHED_TICKS2NS(ppsburst);
 200                 psched_ppscfg_precompute(&new->ppsrate, pps);
 201         }
 202
 203         spin_lock_bh(&police->tcf_lock);
 204         spin_lock_bh(&police->tcfp_lock);
 205         police->tcfp_t_c = ktime_get_ns();
 206         police->tcfp_toks = new->tcfp_burst;
 207         if (new->peak_present)
 208                 police->tcfp_ptoks = new->tcfp_mtu_ptoks;
 209         spin_unlock_bh(&police->tcfp_lock);
 210         goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
 211         new = rcu_replace_pointer(police->params,
 212                                   new,
 213                                   lockdep_is_held(&police->tcf_lock));
 214         spin_unlock_bh(&police->tcf_lock);
 215
 216         if (goto_ch)
 217                 tcf_chain_put_by_act(goto_ch);
 218         if (new)
 219                 kfree_rcu(new, rcu);
 220
 221         return ret;
 222
 223 failure:
 224         qdisc_put_rtab(P_tab);
 225         qdisc_put_rtab(R_tab);
 226         if (goto_ch)
 227                 tcf_chain_put_by_act(goto_ch);
 228 release_idr:
 229         tcf_idr_release(*a, bind);
 230         return err;
 231 }
 232
 233 static bool tcf_police_mtu_check(struct sk_buff *skb, u32 limit)
 234 {
 235         u32 len;
 236
 237         if (skb_is_gso(skb))
 238                 return skb_gso_validate_mac_len(skb, limit);
 239
 240         len = qdisc_pkt_len(skb);
 241         if (skb_at_tc_ingress(skb))
 242                 len += skb->mac_len;
 243
 244         return len <= limit;
 245 }
 246
 247 TC_INDIRECT_SCOPE int tcf_police_act(struct sk_buff *skb,
 248                                      const struct tc_action *a,
 249                                      struct tcf_result *res)
 250 {
 251         struct tcf_police *police = to_police(a);
 252         s64 now, toks, ppstoks = 0, ptoks = 0;
 253         struct tcf_police_params *p;
 254         int ret;
 255
 256         tcf_lastuse_update(&police->tcf_tm);
 257         bstats_update(this_cpu_ptr(police->common.cpu_bstats), skb);
 258
 259         ret = READ_ONCE(police->tcf_action);
 260         p = rcu_dereference_bh(police->params);
 261
 262         if (p->tcfp_ewma_rate) {
 263                 struct gnet_stats_rate_est64 sample;
 264
 265                 if (!gen_estimator_read(&police->tcf_rate_est, &sample) ||
 266                     sample.bps >= p->tcfp_ewma_rate)
 267                         goto inc_overlimits;
 268         }
 269
 270         if (tcf_police_mtu_check(skb, p->tcfp_mtu)) {
 271                 if (!p->rate_present && !p->pps_present) {
 272                         ret = p->tcfp_result;
 273                         goto end;
 274                 }
 275
 276                 now = ktime_get_ns();
 277                 spin_lock_bh(&police->tcfp_lock);
 278                 toks = min_t(s64, now - police->tcfp_t_c, p->tcfp_burst);
 279                 if (p->peak_present) {
 280                         ptoks = toks + police->tcfp_ptoks;
 281                         if (ptoks > p->tcfp_mtu_ptoks)
 282                                 ptoks = p->tcfp_mtu_ptoks;
 283                         ptoks -= (s64)psched_l2t_ns(&p->peak,
 284                                                     qdisc_pkt_len(skb));
 285                 }
 286                 if (p->rate_present) {
 287                         toks += police->tcfp_toks;
 288                         if (toks > p->tcfp_burst)
 289                                 toks = p->tcfp_burst;
 290                         toks -= (s64)psched_l2t_ns(&p->rate, qdisc_pkt_len(skb));
 291                 } else if (p->pps_present) {
 292                         ppstoks = min_t(s64, now - police->tcfp_t_c, p->tcfp_pkt_burst);
 293                         ppstoks += police->tcfp_pkttoks;
 294                         if (ppstoks > p->tcfp_pkt_burst)
 295                                 ppstoks = p->tcfp_pkt_burst;
 296                         ppstoks -= (s64)psched_pkt2t_ns(&p->ppsrate, 1);
 297                 }
 298                 if ((toks | ptoks | ppstoks) >= 0) {
 299                         police->tcfp_t_c = now;
 300                         police->tcfp_toks = toks;
 301                         police->tcfp_ptoks = ptoks;
 302                         police->tcfp_pkttoks = ppstoks;
 303                         spin_unlock_bh(&police->tcfp_lock);
 304                         ret = p->tcfp_result;
 305                         goto inc_drops;
 306                 }
 307                 spin_unlock_bh(&police->tcfp_lock);
 308         }
 309
 310 inc_overlimits:
 311         qstats_overlimit_inc(this_cpu_ptr(police->common.cpu_qstats));
 312 inc_drops:
 313         if (ret == TC_ACT_SHOT)
 314                 qstats_drop_inc(this_cpu_ptr(police->common.cpu_qstats));
 315 end:
 316         return ret;
 317 }
 318
 319 static void tcf_police_cleanup(struct tc_action *a)
 320 {
 321         struct tcf_police *police = to_police(a);
 322         struct tcf_police_params *p;
 323
 324         p = rcu_dereference_protected(police->params, 1);
 325         if (p)
 326                 kfree_rcu(p, rcu);
 327 }
 328
 329 static void tcf_police_stats_update(struct tc_action *a,
 330                                     u64 bytes, u64 packets, u64 drops,
 331                                     u64 lastuse, bool hw)
 332 {
 333         struct tcf_police *police = to_police(a);
 334         struct tcf_t *tm = &police->tcf_tm;
 335
 336         tcf_action_update_stats(a, bytes, packets, drops, hw);
 337         tm->lastuse = max_t(u64, tm->lastuse, lastuse);
 338 }
 339
 340 static int tcf_police_dump(struct sk_buff *skb, struct tc_action *a,
 341                                int bind, int ref)
 342 {
 343         unsigned char *b = skb_tail_pointer(skb);
 344         struct tcf_police *police = to_police(a);
 345         struct tcf_police_params *p;
 346         struct tc_police opt = {
 347                 .index = police->tcf_index,
 348                 .refcnt = refcount_read(&police->tcf_refcnt) - ref,
 349                 .bindcnt = atomic_read(&police->tcf_bindcnt) - bind,
 350         };
 351         struct tcf_t t;
 352
 353         spin_lock_bh(&police->tcf_lock);
 354         opt.action = police->tcf_action;
 355         p = rcu_dereference_protected(police->params,
 356                                       lockdep_is_held(&police->tcf_lock));
 357         opt.mtu = p->tcfp_mtu;
 358         opt.burst = PSCHED_NS2TICKS(p->tcfp_burst);
 359         if (p->rate_present) {
 360                 psched_ratecfg_getrate(&opt.rate, &p->rate);
 361                 if ((p->rate.rate_bytes_ps >= (1ULL << 32)) &&
 362                     nla_put_u64_64bit(skb, TCA_POLICE_RATE64,
 363                                       p->rate.rate_bytes_ps,
 364                                       TCA_POLICE_PAD))
 365                         goto nla_put_failure;
 366         }
 367         if (p->peak_present) {
 368                 psched_ratecfg_getrate(&opt.peakrate, &p->peak);
 369                 if ((p->peak.rate_bytes_ps >= (1ULL << 32)) &&
 370                     nla_put_u64_64bit(skb, TCA_POLICE_PEAKRATE64,
 371                                       p->peak.rate_bytes_ps,
 372                                       TCA_POLICE_PAD))
 373                         goto nla_put_failure;
 374         }
 375         if (p->pps_present) {
 376                 if (nla_put_u64_64bit(skb, TCA_POLICE_PKTRATE64,
 377                                       p->ppsrate.rate_pkts_ps,
 378                                       TCA_POLICE_PAD))
 379                         goto nla_put_failure;
 380                 if (nla_put_u64_64bit(skb, TCA_POLICE_PKTBURST64,
 381                                       PSCHED_NS2TICKS(p->tcfp_pkt_burst),
 382                                       TCA_POLICE_PAD))
 383                         goto nla_put_failure;
 384         }
 385         if (nla_put(skb, TCA_POLICE_TBF, sizeof(opt), &opt))
 386                 goto nla_put_failure;
 387         if (p->tcfp_result &&
 388             nla_put_u32(skb, TCA_POLICE_RESULT, p->tcfp_result))
 389                 goto nla_put_failure;
 390         if (p->tcfp_ewma_rate &&
 391             nla_put_u32(skb, TCA_POLICE_AVRATE, p->tcfp_ewma_rate))
 392                 goto nla_put_failure;
 393
 394         tcf_tm_dump(&t, &police->tcf_tm);
 395         if (nla_put_64bit(skb, TCA_POLICE_TM, sizeof(t), &t, TCA_POLICE_PAD))
 396                 goto nla_put_failure;
 397         spin_unlock_bh(&police->tcf_lock);
 398
 399         return skb->len;
 400
 401 nla_put_failure:
 402         spin_unlock_bh(&police->tcf_lock);
 403         nlmsg_trim(skb, b);
 404         return -1;
 405 }
 406
 407 static int tcf_police_act_to_flow_act(int tc_act, u32 *extval,
 408                                       struct netlink_ext_ack *extack)
 409 {
 410         int act_id = -EOPNOTSUPP;
 411
 412         if (!TC_ACT_EXT_OPCODE(tc_act)) {
 413                 if (tc_act == TC_ACT_OK)
 414                         act_id = FLOW_ACTION_ACCEPT;
 415                 else if (tc_act ==  TC_ACT_SHOT)
 416                         act_id = FLOW_ACTION_DROP;
 417                 else if (tc_act == TC_ACT_PIPE)
 418                         act_id = FLOW_ACTION_PIPE;
 419                 else if (tc_act == TC_ACT_RECLASSIFY)
 420                         NL_SET_ERR_MSG_MOD(extack, "Offload not supported when conform/exceed action is \"reclassify\"");
 421                 else
 422                         NL_SET_ERR_MSG_MOD(extack, "Unsupported conform/exceed action offload");
 423         } else if (TC_ACT_EXT_CMP(tc_act, TC_ACT_GOTO_CHAIN)) {
 424                 act_id = FLOW_ACTION_GOTO;
 425                 *extval = tc_act & TC_ACT_EXT_VAL_MASK;
 426         } else if (TC_ACT_EXT_CMP(tc_act, TC_ACT_JUMP)) {
 427                 act_id = FLOW_ACTION_JUMP;
 428                 *extval = tc_act & TC_ACT_EXT_VAL_MASK;
 429         } else if (tc_act == TC_ACT_UNSPEC) {
 430                 act_id = FLOW_ACTION_CONTINUE;
 431         } else {
 432                 NL_SET_ERR_MSG_MOD(extack, "Unsupported conform/exceed action offload");
 433         }
 434
 435         return act_id;
 436 }
 437
 438 static int tcf_police_offload_act_setup(struct tc_action *act, void *entry_data,
 439                                         u32 *index_inc, bool bind,
 440                                         struct netlink_ext_ack *extack)
 441 {
 442         if (bind) {
 443                 struct flow_action_entry *entry = entry_data;
 444                 struct tcf_police *police = to_police(act);
 445                 struct tcf_police_params *p;
 446                 int act_id;
 447
 448                 p = rcu_dereference_protected(police->params,
 449                                               lockdep_is_held(&police->tcf_lock));
 450
 451                 entry->id = FLOW_ACTION_POLICE;
 452                 entry->police.burst = tcf_police_burst(act);
 453                 entry->police.rate_bytes_ps =
 454                         tcf_police_rate_bytes_ps(act);
 455                 entry->police.peakrate_bytes_ps = tcf_police_peakrate_bytes_ps(act);
 456                 entry->police.avrate = tcf_police_tcfp_ewma_rate(act);
 457                 entry->police.overhead = tcf_police_rate_overhead(act);
 458                 entry->police.burst_pkt = tcf_police_burst_pkt(act);
 459                 entry->police.rate_pkt_ps =
 460                         tcf_police_rate_pkt_ps(act);
 461                 entry->police.mtu = tcf_police_tcfp_mtu(act);
 462
 463                 act_id = tcf_police_act_to_flow_act(police->tcf_action,
 464                                                     &entry->police.exceed.extval,
 465                                                     extack);
 466                 if (act_id < 0)
 467                         return act_id;
 468
 469                 entry->police.exceed.act_id = act_id;
 470
 471                 act_id = tcf_police_act_to_flow_act(p->tcfp_result,
 472                                                     &entry->police.notexceed.extval,
 473                                                     extack);
 474                 if (act_id < 0)
 475                         return act_id;
 476
 477                 entry->police.notexceed.act_id = act_id;
 478
 479                 *index_inc = 1;
 480         } else {
 481                 struct flow_offload_action *fl_action = entry_data;
 482
 483                 fl_action->id = FLOW_ACTION_POLICE;
 484         }
 485
 486         return 0;
 487 }
 488
 489 MODULE_AUTHOR("Alexey Kuznetsov");
 490 MODULE_DESCRIPTION("Policing actions");
 491 MODULE_LICENSE("GPL");
 492
 493 static struct tc_action_ops act_police_ops = {
 494         .kind           =       "police",
 495         .id             =       TCA_ID_POLICE,
 496         .owner          =       THIS_MODULE,
 497         .stats_update   =       tcf_police_stats_update,
 498         .act            =       tcf_police_act,
 499         .dump           =       tcf_police_dump,
 500         .init           =       tcf_police_init,
 501         .cleanup        =       tcf_police_cleanup,
 502         .offload_act_setup =    tcf_police_offload_act_setup,
 503         .size           =       sizeof(struct tcf_police),
 504 };
 505 MODULE_ALIAS_NET_ACT("police");
 506
 507 static __net_init int police_init_net(struct net *net)
 508 {
 509         struct tc_action_net *tn = net_generic(net, act_police_ops.net_id);
 510
 511         return tc_action_net_init(net, tn, &act_police_ops);
 512 }
 513
 514 static void __net_exit police_exit_net(struct list_head *net_list)
 515 {
 516         tc_action_net_exit(net_list, act_police_ops.net_id);
 517 }
 518
 519 static struct pernet_operations police_net_ops = {
 520         .init = police_init_net,
 521         .exit_batch = police_exit_net,
 522         .id   = &act_police_ops.net_id,
 523         .size = sizeof(struct tc_action_net),
 524 };
 525
 526 static int __init police_init_module(void)
 527 {
 528         return tcf_register_action(&act_police_ops, &police_net_ops);
 529 }
 530
 531 static void __exit police_cleanup_module(void)
 532 {
 533         tcf_unregister_action(&act_police_ops, &police_net_ops);
 534 }
 535
 536 module_init(police_init_module);
 537 module_exit(police_cleanup_module);