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