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