1 /* 2 * net/sched/act_police.c Input police filter 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation; either version 7 * 2 of the License, or (at your option) any later version. 8 * 9 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 10 * J Hadi Salim (action changes) 11 */ 12 13 #include <linux/module.h> 14 #include <linux/types.h> 15 #include <linux/kernel.h> 16 #include <linux/string.h> 17 #include <linux/errno.h> 18 #include <linux/skbuff.h> 19 #include <linux/rtnetlink.h> 20 #include <linux/init.h> 21 #include <linux/slab.h> 22 #include <net/act_api.h> 23 #include <net/netlink.h> 24 25 struct tcf_police_params { 26 int tcfp_result; 27 u32 tcfp_ewma_rate; 28 s64 tcfp_burst; 29 u32 tcfp_mtu; 30 s64 tcfp_mtu_ptoks; 31 struct psched_ratecfg rate; 32 bool rate_present; 33 struct psched_ratecfg peak; 34 bool peak_present; 35 struct rcu_head rcu; 36 }; 37 38 struct tcf_police { 39 struct tc_action common; 40 struct tcf_police_params __rcu *params; 41 42 spinlock_t tcfp_lock ____cacheline_aligned_in_smp; 43 s64 tcfp_toks; 44 s64 tcfp_ptoks; 45 s64 tcfp_t_c; 46 }; 47 48 #define to_police(pc) ((struct tcf_police *)pc) 49 50 /* old policer structure from before tc actions */ 51 struct tc_police_compat { 52 u32 index; 53 int action; 54 u32 limit; 55 u32 burst; 56 u32 mtu; 57 struct tc_ratespec rate; 58 struct tc_ratespec peakrate; 59 }; 60 61 /* Each policer is serialized by its individual spinlock */ 62 63 static unsigned int police_net_id; 64 static struct tc_action_ops act_police_ops; 65 66 static int tcf_police_walker(struct net *net, struct sk_buff *skb, 67 struct netlink_callback *cb, int type, 68 const struct tc_action_ops *ops, 69 struct netlink_ext_ack *extack) 70 { 71 struct tc_action_net *tn = net_generic(net, police_net_id); 72 73 return tcf_generic_walker(tn, skb, cb, type, ops, extack); 74 } 75 76 static const struct nla_policy police_policy[TCA_POLICE_MAX + 1] = { 77 [TCA_POLICE_RATE] = { .len = TC_RTAB_SIZE }, 78 [TCA_POLICE_PEAKRATE] = { .len = TC_RTAB_SIZE }, 79 [TCA_POLICE_AVRATE] = { .type = NLA_U32 }, 80 [TCA_POLICE_RESULT] = { .type = NLA_U32 }, 81 }; 82 83 static int tcf_police_init(struct net *net, struct nlattr *nla, 84 struct nlattr *est, struct tc_action **a, 85 int ovr, int bind, bool rtnl_held, 86 struct netlink_ext_ack *extack) 87 { 88 int ret = 0, tcfp_result = TC_ACT_OK, err, size; 89 struct nlattr *tb[TCA_POLICE_MAX + 1]; 90 struct tc_police *parm; 91 struct tcf_police *police; 92 struct qdisc_rate_table *R_tab = NULL, *P_tab = NULL; 93 struct tc_action_net *tn = net_generic(net, police_net_id); 94 struct tcf_police_params *new; 95 bool exists = false; 96 97 if (nla == NULL) 98 return -EINVAL; 99 100 err = nla_parse_nested(tb, TCA_POLICE_MAX, nla, police_policy, NULL); 101 if (err < 0) 102 return err; 103 104 if (tb[TCA_POLICE_TBF] == NULL) 105 return -EINVAL; 106 size = nla_len(tb[TCA_POLICE_TBF]); 107 if (size != sizeof(*parm) && size != sizeof(struct tc_police_compat)) 108 return -EINVAL; 109 110 parm = nla_data(tb[TCA_POLICE_TBF]); 111 err = tcf_idr_check_alloc(tn, &parm->index, a, bind); 112 if (err < 0) 113 return err; 114 exists = err; 115 if (exists && bind) 116 return 0; 117 118 if (!exists) { 119 ret = tcf_idr_create(tn, parm->index, NULL, a, 120 &act_police_ops, bind, true); 121 if (ret) { 122 tcf_idr_cleanup(tn, parm->index); 123 return ret; 124 } 125 ret = ACT_P_CREATED; 126 spin_lock_init(&(to_police(*a)->tcfp_lock)); 127 } else if (!ovr) { 128 tcf_idr_release(*a, bind); 129 return -EEXIST; 130 } 131 132 police = to_police(*a); 133 if (parm->rate.rate) { 134 err = -ENOMEM; 135 R_tab = qdisc_get_rtab(&parm->rate, tb[TCA_POLICE_RATE], NULL); 136 if (R_tab == NULL) 137 goto failure; 138 139 if (parm->peakrate.rate) { 140 P_tab = qdisc_get_rtab(&parm->peakrate, 141 tb[TCA_POLICE_PEAKRATE], NULL); 142 if (P_tab == NULL) 143 goto failure; 144 } 145 } 146 147 if (est) { 148 err = gen_replace_estimator(&police->tcf_bstats, 149 police->common.cpu_bstats, 150 &police->tcf_rate_est, 151 &police->tcf_lock, 152 NULL, est); 153 if (err) 154 goto failure; 155 } else if (tb[TCA_POLICE_AVRATE] && 156 (ret == ACT_P_CREATED || 157 !gen_estimator_active(&police->tcf_rate_est))) { 158 err = -EINVAL; 159 goto failure; 160 } 161 162 if (tb[TCA_POLICE_RESULT]) { 163 tcfp_result = nla_get_u32(tb[TCA_POLICE_RESULT]); 164 if (TC_ACT_EXT_CMP(tcfp_result, TC_ACT_GOTO_CHAIN)) { 165 NL_SET_ERR_MSG(extack, 166 "goto chain not allowed on fallback"); 167 err = -EINVAL; 168 goto failure; 169 } 170 } 171 172 new = kzalloc(sizeof(*new), GFP_KERNEL); 173 if (unlikely(!new)) { 174 err = -ENOMEM; 175 goto failure; 176 } 177 178 /* No failure allowed after this point */ 179 new->tcfp_result = tcfp_result; 180 new->tcfp_mtu = parm->mtu; 181 if (!new->tcfp_mtu) { 182 new->tcfp_mtu = ~0; 183 if (R_tab) 184 new->tcfp_mtu = 255 << R_tab->rate.cell_log; 185 } 186 if (R_tab) { 187 new->rate_present = true; 188 psched_ratecfg_precompute(&new->rate, &R_tab->rate, 0); 189 qdisc_put_rtab(R_tab); 190 } else { 191 new->rate_present = false; 192 } 193 if (P_tab) { 194 new->peak_present = true; 195 psched_ratecfg_precompute(&new->peak, &P_tab->rate, 0); 196 qdisc_put_rtab(P_tab); 197 } else { 198 new->peak_present = false; 199 } 200 201 new->tcfp_burst = PSCHED_TICKS2NS(parm->burst); 202 if (new->peak_present) 203 new->tcfp_mtu_ptoks = (s64)psched_l2t_ns(&new->peak, 204 new->tcfp_mtu); 205 206 if (tb[TCA_POLICE_AVRATE]) 207 new->tcfp_ewma_rate = nla_get_u32(tb[TCA_POLICE_AVRATE]); 208 209 spin_lock_bh(&police->tcf_lock); 210 spin_lock_bh(&police->tcfp_lock); 211 police->tcfp_t_c = ktime_get_ns(); 212 police->tcfp_toks = new->tcfp_burst; 213 if (new->peak_present) 214 police->tcfp_ptoks = new->tcfp_mtu_ptoks; 215 spin_unlock_bh(&police->tcfp_lock); 216 police->tcf_action = parm->action; 217 rcu_swap_protected(police->params, 218 new, 219 lockdep_is_held(&police->tcf_lock)); 220 spin_unlock_bh(&police->tcf_lock); 221 222 if (new) 223 kfree_rcu(new, rcu); 224 225 if (ret == ACT_P_CREATED) 226 tcf_idr_insert(tn, *a); 227 return ret; 228 229 failure: 230 qdisc_put_rtab(P_tab); 231 qdisc_put_rtab(R_tab); 232 tcf_idr_release(*a, bind); 233 return err; 234 } 235 236 static int tcf_police_act(struct sk_buff *skb, const struct tc_action *a, 237 struct tcf_result *res) 238 { 239 struct tcf_police *police = to_police(a); 240 struct tcf_police_params *p; 241 s64 now, toks, ptoks = 0; 242 int ret; 243 244 tcf_lastuse_update(&police->tcf_tm); 245 bstats_cpu_update(this_cpu_ptr(police->common.cpu_bstats), skb); 246 247 ret = READ_ONCE(police->tcf_action); 248 p = rcu_dereference_bh(police->params); 249 250 if (p->tcfp_ewma_rate) { 251 struct gnet_stats_rate_est64 sample; 252 253 if (!gen_estimator_read(&police->tcf_rate_est, &sample) || 254 sample.bps >= p->tcfp_ewma_rate) 255 goto inc_overlimits; 256 } 257 258 if (qdisc_pkt_len(skb) <= p->tcfp_mtu) { 259 if (!p->rate_present) { 260 ret = p->tcfp_result; 261 goto end; 262 } 263 264 now = ktime_get_ns(); 265 spin_lock_bh(&police->tcfp_lock); 266 toks = min_t(s64, now - police->tcfp_t_c, p->tcfp_burst); 267 if (p->peak_present) { 268 ptoks = toks + police->tcfp_ptoks; 269 if (ptoks > p->tcfp_mtu_ptoks) 270 ptoks = p->tcfp_mtu_ptoks; 271 ptoks -= (s64)psched_l2t_ns(&p->peak, 272 qdisc_pkt_len(skb)); 273 } 274 toks += police->tcfp_toks; 275 if (toks > p->tcfp_burst) 276 toks = p->tcfp_burst; 277 toks -= (s64)psched_l2t_ns(&p->rate, qdisc_pkt_len(skb)); 278 if ((toks|ptoks) >= 0) { 279 police->tcfp_t_c = now; 280 police->tcfp_toks = toks; 281 police->tcfp_ptoks = ptoks; 282 spin_unlock_bh(&police->tcfp_lock); 283 ret = p->tcfp_result; 284 goto inc_drops; 285 } 286 spin_unlock_bh(&police->tcfp_lock); 287 } 288 289 inc_overlimits: 290 qstats_overlimit_inc(this_cpu_ptr(police->common.cpu_qstats)); 291 inc_drops: 292 if (ret == TC_ACT_SHOT) 293 qstats_drop_inc(this_cpu_ptr(police->common.cpu_qstats)); 294 end: 295 return ret; 296 } 297 298 static void tcf_police_cleanup(struct tc_action *a) 299 { 300 struct tcf_police *police = to_police(a); 301 struct tcf_police_params *p; 302 303 p = rcu_dereference_protected(police->params, 1); 304 if (p) 305 kfree_rcu(p, rcu); 306 } 307 308 static int tcf_police_dump(struct sk_buff *skb, struct tc_action *a, 309 int bind, int ref) 310 { 311 unsigned char *b = skb_tail_pointer(skb); 312 struct tcf_police *police = to_police(a); 313 struct tcf_police_params *p; 314 struct tc_police opt = { 315 .index = police->tcf_index, 316 .refcnt = refcount_read(&police->tcf_refcnt) - ref, 317 .bindcnt = atomic_read(&police->tcf_bindcnt) - bind, 318 }; 319 struct tcf_t t; 320 321 spin_lock_bh(&police->tcf_lock); 322 opt.action = police->tcf_action; 323 p = rcu_dereference_protected(police->params, 324 lockdep_is_held(&police->tcf_lock)); 325 opt.mtu = p->tcfp_mtu; 326 opt.burst = PSCHED_NS2TICKS(p->tcfp_burst); 327 if (p->rate_present) 328 psched_ratecfg_getrate(&opt.rate, &p->rate); 329 if (p->peak_present) 330 psched_ratecfg_getrate(&opt.peakrate, &p->peak); 331 if (nla_put(skb, TCA_POLICE_TBF, sizeof(opt), &opt)) 332 goto nla_put_failure; 333 if (p->tcfp_result && 334 nla_put_u32(skb, TCA_POLICE_RESULT, p->tcfp_result)) 335 goto nla_put_failure; 336 if (p->tcfp_ewma_rate && 337 nla_put_u32(skb, TCA_POLICE_AVRATE, p->tcfp_ewma_rate)) 338 goto nla_put_failure; 339 340 t.install = jiffies_to_clock_t(jiffies - police->tcf_tm.install); 341 t.lastuse = jiffies_to_clock_t(jiffies - police->tcf_tm.lastuse); 342 t.firstuse = jiffies_to_clock_t(jiffies - police->tcf_tm.firstuse); 343 t.expires = jiffies_to_clock_t(police->tcf_tm.expires); 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 .type = TCA_ID_POLICE, 370 .owner = THIS_MODULE, 371 .act = tcf_police_act, 372 .dump = tcf_police_dump, 373 .init = tcf_police_init, 374 .walk = tcf_police_walker, 375 .lookup = tcf_police_search, 376 .cleanup = tcf_police_cleanup, 377 .size = sizeof(struct tcf_police), 378 }; 379 380 static __net_init int police_init_net(struct net *net) 381 { 382 struct tc_action_net *tn = net_generic(net, police_net_id); 383 384 return tc_action_net_init(tn, &act_police_ops); 385 } 386 387 static void __net_exit police_exit_net(struct list_head *net_list) 388 { 389 tc_action_net_exit(net_list, police_net_id); 390 } 391 392 static struct pernet_operations police_net_ops = { 393 .init = police_init_net, 394 .exit_batch = police_exit_net, 395 .id = &police_net_id, 396 .size = sizeof(struct tc_action_net), 397 }; 398 399 static int __init police_init_module(void) 400 { 401 return tcf_register_action(&act_police_ops, &police_net_ops); 402 } 403 404 static void __exit police_cleanup_module(void) 405 { 406 tcf_unregister_action(&act_police_ops, &police_net_ops); 407 } 408 409 module_init(police_init_module); 410 module_exit(police_cleanup_module); 411