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