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         if (ret == ACT_P_CREATED)
 205                 tcf_idr_insert(tn, *a);
 206         return ret;
 207
 208 failure:
 209         qdisc_put_rtab(P_tab);
 210         qdisc_put_rtab(R_tab);
 211         if (goto_ch)
 212                 tcf_chain_put_by_act(goto_ch);
 213 release_idr:
 214         tcf_idr_release(*a, bind);
 215         return err;
 216 }
 217
 218 static int tcf_police_act(struct sk_buff *skb, const struct tc_action *a,
 219                           struct tcf_result *res)
 220 {
 221         struct tcf_police *police = to_police(a);
 222         struct tcf_police_params *p;
 223         s64 now, toks, ptoks = 0;
 224         int ret;
 225
 226         tcf_lastuse_update(&police->tcf_tm);
 227         bstats_cpu_update(this_cpu_ptr(police->common.cpu_bstats), skb);
 228
 229         ret = READ_ONCE(police->tcf_action);
 230         p = rcu_dereference_bh(police->params);
 231
 232         if (p->tcfp_ewma_rate) {
 233                 struct gnet_stats_rate_est64 sample;
 234
 235                 if (!gen_estimator_read(&police->tcf_rate_est, &sample) ||
 236                     sample.bps >= p->tcfp_ewma_rate)
 237                         goto inc_overlimits;
 238         }
 239
 240         if (qdisc_pkt_len(skb) <= p->tcfp_mtu) {
 241                 if (!p->rate_present) {
 242                         ret = p->tcfp_result;
 243                         goto end;
 244                 }
 245
 246                 now = ktime_get_ns();
 247                 spin_lock_bh(&police->tcfp_lock);
 248                 toks = min_t(s64, now - police->tcfp_t_c, p->tcfp_burst);
 249                 if (p->peak_present) {
 250                         ptoks = toks + police->tcfp_ptoks;
 251                         if (ptoks > p->tcfp_mtu_ptoks)
 252                                 ptoks = p->tcfp_mtu_ptoks;
 253                         ptoks -= (s64)psched_l2t_ns(&p->peak,
 254                                                     qdisc_pkt_len(skb));
 255                 }
 256                 toks += police->tcfp_toks;
 257                 if (toks > p->tcfp_burst)
 258                         toks = p->tcfp_burst;
 259                 toks -= (s64)psched_l2t_ns(&p->rate, qdisc_pkt_len(skb));
 260                 if ((toks|ptoks) >= 0) {
 261                         police->tcfp_t_c = now;
 262                         police->tcfp_toks = toks;
 263                         police->tcfp_ptoks = ptoks;
 264                         spin_unlock_bh(&police->tcfp_lock);
 265                         ret = p->tcfp_result;
 266                         goto inc_drops;
 267                 }
 268                 spin_unlock_bh(&police->tcfp_lock);
 269         }
 270
 271 inc_overlimits:
 272         qstats_overlimit_inc(this_cpu_ptr(police->common.cpu_qstats));
 273 inc_drops:
 274         if (ret == TC_ACT_SHOT)
 275                 qstats_drop_inc(this_cpu_ptr(police->common.cpu_qstats));
 276 end:
 277         return ret;
 278 }
 279
 280 static void tcf_police_cleanup(struct tc_action *a)
 281 {
 282         struct tcf_police *police = to_police(a);
 283         struct tcf_police_params *p;
 284
 285         p = rcu_dereference_protected(police->params, 1);
 286         if (p)
 287                 kfree_rcu(p, rcu);
 288 }
 289
 290 static void tcf_police_stats_update(struct tc_action *a,
 291                                     u64 bytes, u32 packets,
 292                                     u64 lastuse, bool hw)
 293 {
 294         struct tcf_police *police = to_police(a);
 295         struct tcf_t *tm = &police->tcf_tm;
 296
 297         _bstats_cpu_update(this_cpu_ptr(a->cpu_bstats), bytes, packets);
 298         if (hw)
 299                 _bstats_cpu_update(this_cpu_ptr(a->cpu_bstats_hw),
 300                                    bytes, packets);
 301         tm->lastuse = max_t(u64, tm->lastuse, lastuse);
 302 }
 303
 304 static int tcf_police_dump(struct sk_buff *skb, struct tc_action *a,
 305                                int bind, int ref)
 306 {
 307         unsigned char *b = skb_tail_pointer(skb);
 308         struct tcf_police *police = to_police(a);
 309         struct tcf_police_params *p;
 310         struct tc_police opt = {
 311                 .index = police->tcf_index,
 312                 .refcnt = refcount_read(&police->tcf_refcnt) - ref,
 313                 .bindcnt = atomic_read(&police->tcf_bindcnt) - bind,
 314         };
 315         struct tcf_t t;
 316
 317         spin_lock_bh(&police->tcf_lock);
 318         opt.action = police->tcf_action;
 319         p = rcu_dereference_protected(police->params,
 320                                       lockdep_is_held(&police->tcf_lock));
 321         opt.mtu = p->tcfp_mtu;
 322         opt.burst = PSCHED_NS2TICKS(p->tcfp_burst);
 323         if (p->rate_present) {
 324                 psched_ratecfg_getrate(&opt.rate, &p->rate);
 325                 if ((police->params->rate.rate_bytes_ps >= (1ULL << 32)) &&
 326                     nla_put_u64_64bit(skb, TCA_POLICE_RATE64,
 327                                       police->params->rate.rate_bytes_ps,
 328                                       TCA_POLICE_PAD))
 329                         goto nla_put_failure;
 330         }
 331         if (p->peak_present) {
 332                 psched_ratecfg_getrate(&opt.peakrate, &p->peak);
 333                 if ((police->params->peak.rate_bytes_ps >= (1ULL << 32)) &&
 334                     nla_put_u64_64bit(skb, TCA_POLICE_PEAKRATE64,
 335                                       police->params->peak.rate_bytes_ps,
 336                                       TCA_POLICE_PAD))
 337                         goto nla_put_failure;
 338         }
 339         if (nla_put(skb, TCA_POLICE_TBF, sizeof(opt), &opt))
 340                 goto nla_put_failure;
 341         if (p->tcfp_result &&
 342             nla_put_u32(skb, TCA_POLICE_RESULT, p->tcfp_result))
 343                 goto nla_put_failure;
 344         if (p->tcfp_ewma_rate &&
 345             nla_put_u32(skb, TCA_POLICE_AVRATE, p->tcfp_ewma_rate))
 346                 goto nla_put_failure;
 347
 348         t.install = jiffies_to_clock_t(jiffies - police->tcf_tm.install);
 349         t.lastuse = jiffies_to_clock_t(jiffies - police->tcf_tm.lastuse);
 350         t.firstuse = jiffies_to_clock_t(jiffies - police->tcf_tm.firstuse);
 351         t.expires = jiffies_to_clock_t(police->tcf_tm.expires);
 352         if (nla_put_64bit(skb, TCA_POLICE_TM, sizeof(t), &t, TCA_POLICE_PAD))
 353                 goto nla_put_failure;
 354         spin_unlock_bh(&police->tcf_lock);
 355
 356         return skb->len;
 357
 358 nla_put_failure:
 359         spin_unlock_bh(&police->tcf_lock);
 360         nlmsg_trim(skb, b);
 361         return -1;
 362 }
 363
 364 static int tcf_police_search(struct net *net, struct tc_action **a, u32 index)
 365 {
 366         struct tc_action_net *tn = net_generic(net, police_net_id);
 367
 368         return tcf_idr_search(tn, a, index);
 369 }
 370
 371 MODULE_AUTHOR("Alexey Kuznetsov");
 372 MODULE_DESCRIPTION("Policing actions");
 373 MODULE_LICENSE("GPL");
 374
 375 static struct tc_action_ops act_police_ops = {
 376         .kind           =       "police",
 377         .id             =       TCA_ID_POLICE,
 378         .owner          =       THIS_MODULE,
 379         .stats_update   =       tcf_police_stats_update,
 380         .act            =       tcf_police_act,
 381         .dump           =       tcf_police_dump,
 382         .init           =       tcf_police_init,
 383         .walk           =       tcf_police_walker,
 384         .lookup         =       tcf_police_search,
 385         .cleanup        =       tcf_police_cleanup,
 386         .size           =       sizeof(struct tcf_police),
 387 };
 388
 389 static __net_init int police_init_net(struct net *net)
 390 {
 391         struct tc_action_net *tn = net_generic(net, police_net_id);
 392
 393         return tc_action_net_init(net, tn, &act_police_ops);
 394 }
 395
 396 static void __net_exit police_exit_net(struct list_head *net_list)
 397 {
 398         tc_action_net_exit(net_list, police_net_id);
 399 }
 400
 401 static struct pernet_operations police_net_ops = {
 402         .init = police_init_net,
 403         .exit_batch = police_exit_net,
 404         .id   = &police_net_id,
 405         .size = sizeof(struct tc_action_net),
 406 };
 407
 408 static int __init police_init_module(void)
 409 {
 410         return tcf_register_action(&act_police_ops, &police_net_ops);
 411 }
 412
 413 static void __exit police_cleanup_module(void)
 414 {
 415         tcf_unregister_action(&act_police_ops, &police_net_ops);
 416 }
 417
 418 module_init(police_init_module);
 419 module_exit(police_cleanup_module);