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 [TCA_POLICE_PKTRATE64] = { .type = NLA_U64, .min = 1 }, 46 [TCA_POLICE_PKTBURST64] = { .type = NLA_U64, .min = 1 }, 47 }; 48 49 static int tcf_police_init(struct net *net, struct nlattr *nla, 50 struct nlattr *est, struct tc_action **a, 51 int ovr, int bind, bool rtnl_held, 52 struct tcf_proto *tp, u32 flags, 53 struct netlink_ext_ack *extack) 54 { 55 int ret = 0, tcfp_result = TC_ACT_OK, err, size; 56 struct nlattr *tb[TCA_POLICE_MAX + 1]; 57 struct tcf_chain *goto_ch = NULL; 58 struct tc_police *parm; 59 struct tcf_police *police; 60 struct qdisc_rate_table *R_tab = NULL, *P_tab = NULL; 61 struct tc_action_net *tn = net_generic(net, police_net_id); 62 struct tcf_police_params *new; 63 bool exists = false; 64 u32 index; 65 u64 rate64, prate64; 66 u64 pps, ppsburst; 67 68 if (nla == NULL) 69 return -EINVAL; 70 71 err = nla_parse_nested_deprecated(tb, TCA_POLICE_MAX, nla, 72 police_policy, NULL); 73 if (err < 0) 74 return err; 75 76 if (tb[TCA_POLICE_TBF] == NULL) 77 return -EINVAL; 78 size = nla_len(tb[TCA_POLICE_TBF]); 79 if (size != sizeof(*parm) && size != sizeof(struct tc_police_compat)) 80 return -EINVAL; 81 82 parm = nla_data(tb[TCA_POLICE_TBF]); 83 index = parm->index; 84 err = tcf_idr_check_alloc(tn, &index, a, bind); 85 if (err < 0) 86 return err; 87 exists = err; 88 if (exists && bind) 89 return 0; 90 91 if (!exists) { 92 ret = tcf_idr_create(tn, index, NULL, a, 93 &act_police_ops, bind, true, 0); 94 if (ret) { 95 tcf_idr_cleanup(tn, index); 96 return ret; 97 } 98 ret = ACT_P_CREATED; 99 spin_lock_init(&(to_police(*a)->tcfp_lock)); 100 } else if (!ovr) { 101 tcf_idr_release(*a, bind); 102 return -EEXIST; 103 } 104 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack); 105 if (err < 0) 106 goto release_idr; 107 108 police = to_police(*a); 109 if (parm->rate.rate) { 110 err = -ENOMEM; 111 R_tab = qdisc_get_rtab(&parm->rate, tb[TCA_POLICE_RATE], NULL); 112 if (R_tab == NULL) 113 goto failure; 114 115 if (parm->peakrate.rate) { 116 P_tab = qdisc_get_rtab(&parm->peakrate, 117 tb[TCA_POLICE_PEAKRATE], NULL); 118 if (P_tab == NULL) 119 goto failure; 120 } 121 } 122 123 if (est) { 124 err = gen_replace_estimator(&police->tcf_bstats, 125 police->common.cpu_bstats, 126 &police->tcf_rate_est, 127 &police->tcf_lock, 128 NULL, est); 129 if (err) 130 goto failure; 131 } else if (tb[TCA_POLICE_AVRATE] && 132 (ret == ACT_P_CREATED || 133 !gen_estimator_active(&police->tcf_rate_est))) { 134 err = -EINVAL; 135 goto failure; 136 } 137 138 if (tb[TCA_POLICE_RESULT]) { 139 tcfp_result = nla_get_u32(tb[TCA_POLICE_RESULT]); 140 if (TC_ACT_EXT_CMP(tcfp_result, TC_ACT_GOTO_CHAIN)) { 141 NL_SET_ERR_MSG(extack, 142 "goto chain not allowed on fallback"); 143 err = -EINVAL; 144 goto failure; 145 } 146 } 147 148 if ((tb[TCA_POLICE_PKTRATE64] && !tb[TCA_POLICE_PKTBURST64]) || 149 (!tb[TCA_POLICE_PKTRATE64] && tb[TCA_POLICE_PKTBURST64])) { 150 NL_SET_ERR_MSG(extack, 151 "Both or neither packet-per-second burst and rate must be provided"); 152 err = -EINVAL; 153 goto failure; 154 } 155 156 if (tb[TCA_POLICE_PKTRATE64] && R_tab) { 157 NL_SET_ERR_MSG(extack, 158 "packet-per-second and byte-per-second rate limits not allowed in same action"); 159 err = -EINVAL; 160 goto failure; 161 } 162 163 new = kzalloc(sizeof(*new), GFP_KERNEL); 164 if (unlikely(!new)) { 165 err = -ENOMEM; 166 goto failure; 167 } 168 169 /* No failure allowed after this point */ 170 new->tcfp_result = tcfp_result; 171 new->tcfp_mtu = parm->mtu; 172 if (!new->tcfp_mtu) { 173 new->tcfp_mtu = ~0; 174 if (R_tab) 175 new->tcfp_mtu = 255 << R_tab->rate.cell_log; 176 } 177 if (R_tab) { 178 new->rate_present = true; 179 rate64 = tb[TCA_POLICE_RATE64] ? 180 nla_get_u64(tb[TCA_POLICE_RATE64]) : 0; 181 psched_ratecfg_precompute(&new->rate, &R_tab->rate, rate64); 182 qdisc_put_rtab(R_tab); 183 } else { 184 new->rate_present = false; 185 } 186 if (P_tab) { 187 new->peak_present = true; 188 prate64 = tb[TCA_POLICE_PEAKRATE64] ? 189 nla_get_u64(tb[TCA_POLICE_PEAKRATE64]) : 0; 190 psched_ratecfg_precompute(&new->peak, &P_tab->rate, prate64); 191 qdisc_put_rtab(P_tab); 192 } else { 193 new->peak_present = false; 194 } 195 196 new->tcfp_burst = PSCHED_TICKS2NS(parm->burst); 197 if (new->peak_present) 198 new->tcfp_mtu_ptoks = (s64)psched_l2t_ns(&new->peak, 199 new->tcfp_mtu); 200 201 if (tb[TCA_POLICE_AVRATE]) 202 new->tcfp_ewma_rate = nla_get_u32(tb[TCA_POLICE_AVRATE]); 203 204 if (tb[TCA_POLICE_PKTRATE64]) { 205 pps = nla_get_u64(tb[TCA_POLICE_PKTRATE64]); 206 ppsburst = nla_get_u64(tb[TCA_POLICE_PKTBURST64]); 207 new->pps_present = true; 208 new->tcfp_pkt_burst = PSCHED_TICKS2NS(ppsburst); 209 psched_ppscfg_precompute(&new->ppsrate, pps); 210 } 211 212 spin_lock_bh(&police->tcf_lock); 213 spin_lock_bh(&police->tcfp_lock); 214 police->tcfp_t_c = ktime_get_ns(); 215 police->tcfp_toks = new->tcfp_burst; 216 if (new->peak_present) 217 police->tcfp_ptoks = new->tcfp_mtu_ptoks; 218 spin_unlock_bh(&police->tcfp_lock); 219 goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch); 220 new = rcu_replace_pointer(police->params, 221 new, 222 lockdep_is_held(&police->tcf_lock)); 223 spin_unlock_bh(&police->tcf_lock); 224 225 if (goto_ch) 226 tcf_chain_put_by_act(goto_ch); 227 if (new) 228 kfree_rcu(new, rcu); 229 230 return ret; 231 232 failure: 233 qdisc_put_rtab(P_tab); 234 qdisc_put_rtab(R_tab); 235 if (goto_ch) 236 tcf_chain_put_by_act(goto_ch); 237 release_idr: 238 tcf_idr_release(*a, bind); 239 return err; 240 } 241 242 static int tcf_police_act(struct sk_buff *skb, const struct tc_action *a, 243 struct tcf_result *res) 244 { 245 struct tcf_police *police = to_police(a); 246 s64 now, toks, ppstoks = 0, ptoks = 0; 247 struct tcf_police_params *p; 248 int ret; 249 250 tcf_lastuse_update(&police->tcf_tm); 251 bstats_cpu_update(this_cpu_ptr(police->common.cpu_bstats), skb); 252 253 ret = READ_ONCE(police->tcf_action); 254 p = rcu_dereference_bh(police->params); 255 256 if (p->tcfp_ewma_rate) { 257 struct gnet_stats_rate_est64 sample; 258 259 if (!gen_estimator_read(&police->tcf_rate_est, &sample) || 260 sample.bps >= p->tcfp_ewma_rate) 261 goto inc_overlimits; 262 } 263 264 if (qdisc_pkt_len(skb) <= p->tcfp_mtu) { 265 if (!p->rate_present && !p->pps_present) { 266 ret = p->tcfp_result; 267 goto end; 268 } 269 270 now = ktime_get_ns(); 271 spin_lock_bh(&police->tcfp_lock); 272 toks = min_t(s64, now - police->tcfp_t_c, p->tcfp_burst); 273 if (p->peak_present) { 274 ptoks = toks + police->tcfp_ptoks; 275 if (ptoks > p->tcfp_mtu_ptoks) 276 ptoks = p->tcfp_mtu_ptoks; 277 ptoks -= (s64)psched_l2t_ns(&p->peak, 278 qdisc_pkt_len(skb)); 279 } 280 if (p->rate_present) { 281 toks += police->tcfp_toks; 282 if (toks > p->tcfp_burst) 283 toks = p->tcfp_burst; 284 toks -= (s64)psched_l2t_ns(&p->rate, qdisc_pkt_len(skb)); 285 } else if (p->pps_present) { 286 ppstoks = min_t(s64, now - police->tcfp_t_c, p->tcfp_pkt_burst); 287 ppstoks += police->tcfp_pkttoks; 288 if (ppstoks > p->tcfp_pkt_burst) 289 ppstoks = p->tcfp_pkt_burst; 290 ppstoks -= (s64)psched_pkt2t_ns(&p->ppsrate, 1); 291 } 292 if ((toks | ptoks | ppstoks) >= 0) { 293 police->tcfp_t_c = now; 294 police->tcfp_toks = toks; 295 police->tcfp_ptoks = ptoks; 296 police->tcfp_pkttoks = ppstoks; 297 spin_unlock_bh(&police->tcfp_lock); 298 ret = p->tcfp_result; 299 goto inc_drops; 300 } 301 spin_unlock_bh(&police->tcfp_lock); 302 } 303 304 inc_overlimits: 305 qstats_overlimit_inc(this_cpu_ptr(police->common.cpu_qstats)); 306 inc_drops: 307 if (ret == TC_ACT_SHOT) 308 qstats_drop_inc(this_cpu_ptr(police->common.cpu_qstats)); 309 end: 310 return ret; 311 } 312 313 static void tcf_police_cleanup(struct tc_action *a) 314 { 315 struct tcf_police *police = to_police(a); 316 struct tcf_police_params *p; 317 318 p = rcu_dereference_protected(police->params, 1); 319 if (p) 320 kfree_rcu(p, rcu); 321 } 322 323 static void tcf_police_stats_update(struct tc_action *a, 324 u64 bytes, u64 packets, u64 drops, 325 u64 lastuse, bool hw) 326 { 327 struct tcf_police *police = to_police(a); 328 struct tcf_t *tm = &police->tcf_tm; 329 330 tcf_action_update_stats(a, bytes, packets, drops, hw); 331 tm->lastuse = max_t(u64, tm->lastuse, lastuse); 332 } 333 334 static int tcf_police_dump(struct sk_buff *skb, struct tc_action *a, 335 int bind, int ref) 336 { 337 unsigned char *b = skb_tail_pointer(skb); 338 struct tcf_police *police = to_police(a); 339 struct tcf_police_params *p; 340 struct tc_police opt = { 341 .index = police->tcf_index, 342 .refcnt = refcount_read(&police->tcf_refcnt) - ref, 343 .bindcnt = atomic_read(&police->tcf_bindcnt) - bind, 344 }; 345 struct tcf_t t; 346 347 spin_lock_bh(&police->tcf_lock); 348 opt.action = police->tcf_action; 349 p = rcu_dereference_protected(police->params, 350 lockdep_is_held(&police->tcf_lock)); 351 opt.mtu = p->tcfp_mtu; 352 opt.burst = PSCHED_NS2TICKS(p->tcfp_burst); 353 if (p->rate_present) { 354 psched_ratecfg_getrate(&opt.rate, &p->rate); 355 if ((police->params->rate.rate_bytes_ps >= (1ULL << 32)) && 356 nla_put_u64_64bit(skb, TCA_POLICE_RATE64, 357 police->params->rate.rate_bytes_ps, 358 TCA_POLICE_PAD)) 359 goto nla_put_failure; 360 } 361 if (p->peak_present) { 362 psched_ratecfg_getrate(&opt.peakrate, &p->peak); 363 if ((police->params->peak.rate_bytes_ps >= (1ULL << 32)) && 364 nla_put_u64_64bit(skb, TCA_POLICE_PEAKRATE64, 365 police->params->peak.rate_bytes_ps, 366 TCA_POLICE_PAD)) 367 goto nla_put_failure; 368 } 369 if (p->pps_present) { 370 if (nla_put_u64_64bit(skb, TCA_POLICE_PKTRATE64, 371 police->params->ppsrate.rate_pkts_ps, 372 TCA_POLICE_PAD)) 373 goto nla_put_failure; 374 if (nla_put_u64_64bit(skb, TCA_POLICE_PKTBURST64, 375 PSCHED_NS2TICKS(p->tcfp_pkt_burst), 376 TCA_POLICE_PAD)) 377 goto nla_put_failure; 378 } 379 if (nla_put(skb, TCA_POLICE_TBF, sizeof(opt), &opt)) 380 goto nla_put_failure; 381 if (p->tcfp_result && 382 nla_put_u32(skb, TCA_POLICE_RESULT, p->tcfp_result)) 383 goto nla_put_failure; 384 if (p->tcfp_ewma_rate && 385 nla_put_u32(skb, TCA_POLICE_AVRATE, p->tcfp_ewma_rate)) 386 goto nla_put_failure; 387 388 tcf_tm_dump(&t, &police->tcf_tm); 389 if (nla_put_64bit(skb, TCA_POLICE_TM, sizeof(t), &t, TCA_POLICE_PAD)) 390 goto nla_put_failure; 391 spin_unlock_bh(&police->tcf_lock); 392 393 return skb->len; 394 395 nla_put_failure: 396 spin_unlock_bh(&police->tcf_lock); 397 nlmsg_trim(skb, b); 398 return -1; 399 } 400 401 static int tcf_police_search(struct net *net, struct tc_action **a, u32 index) 402 { 403 struct tc_action_net *tn = net_generic(net, police_net_id); 404 405 return tcf_idr_search(tn, a, index); 406 } 407 408 MODULE_AUTHOR("Alexey Kuznetsov"); 409 MODULE_DESCRIPTION("Policing actions"); 410 MODULE_LICENSE("GPL"); 411 412 static struct tc_action_ops act_police_ops = { 413 .kind = "police", 414 .id = TCA_ID_POLICE, 415 .owner = THIS_MODULE, 416 .stats_update = tcf_police_stats_update, 417 .act = tcf_police_act, 418 .dump = tcf_police_dump, 419 .init = tcf_police_init, 420 .walk = tcf_police_walker, 421 .lookup = tcf_police_search, 422 .cleanup = tcf_police_cleanup, 423 .size = sizeof(struct tcf_police), 424 }; 425 426 static __net_init int police_init_net(struct net *net) 427 { 428 struct tc_action_net *tn = net_generic(net, police_net_id); 429 430 return tc_action_net_init(net, tn, &act_police_ops); 431 } 432 433 static void __net_exit police_exit_net(struct list_head *net_list) 434 { 435 tc_action_net_exit(net_list, police_net_id); 436 } 437 438 static struct pernet_operations police_net_ops = { 439 .init = police_init_net, 440 .exit_batch = police_exit_net, 441 .id = &police_net_id, 442 .size = sizeof(struct tc_action_net), 443 }; 444 445 static int __init police_init_module(void) 446 { 447 return tcf_register_action(&act_police_ops, &police_net_ops); 448 } 449 450 static void __exit police_cleanup_module(void) 451 { 452 tcf_unregister_action(&act_police_ops, &police_net_ops); 453 } 454 455 module_init(police_init_module); 456 module_exit(police_cleanup_module); 457