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