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_toks; 31 s64 tcfp_ptoks; 32 s64 tcfp_mtu_ptoks; 33 s64 tcfp_t_c; 34 struct psched_ratecfg rate; 35 bool rate_present; 36 struct psched_ratecfg peak; 37 bool peak_present; 38 struct rcu_head rcu; 39 }; 40 41 struct tcf_police { 42 struct tc_action common; 43 struct tcf_police_params __rcu *params; 44 }; 45 46 #define to_police(pc) ((struct tcf_police *)pc) 47 48 /* old policer structure from before tc actions */ 49 struct tc_police_compat { 50 u32 index; 51 int action; 52 u32 limit; 53 u32 burst; 54 u32 mtu; 55 struct tc_ratespec rate; 56 struct tc_ratespec peakrate; 57 }; 58 59 /* Each policer is serialized by its individual spinlock */ 60 61 static unsigned int police_net_id; 62 static struct tc_action_ops act_police_ops; 63 64 static int tcf_police_walker(struct net *net, struct sk_buff *skb, 65 struct netlink_callback *cb, int type, 66 const struct tc_action_ops *ops, 67 struct netlink_ext_ack *extack) 68 { 69 struct tc_action_net *tn = net_generic(net, police_net_id); 70 71 return tcf_generic_walker(tn, skb, cb, type, ops, extack); 72 } 73 74 static const struct nla_policy police_policy[TCA_POLICE_MAX + 1] = { 75 [TCA_POLICE_RATE] = { .len = TC_RTAB_SIZE }, 76 [TCA_POLICE_PEAKRATE] = { .len = TC_RTAB_SIZE }, 77 [TCA_POLICE_AVRATE] = { .type = NLA_U32 }, 78 [TCA_POLICE_RESULT] = { .type = NLA_U32 }, 79 }; 80 81 static int tcf_police_init(struct net *net, struct nlattr *nla, 82 struct nlattr *est, struct tc_action **a, 83 int ovr, int bind, bool rtnl_held, 84 struct netlink_ext_ack *extack) 85 { 86 int ret = 0, err; 87 struct nlattr *tb[TCA_POLICE_MAX + 1]; 88 struct tc_police *parm; 89 struct tcf_police *police; 90 struct qdisc_rate_table *R_tab = NULL, *P_tab = NULL; 91 struct tc_action_net *tn = net_generic(net, police_net_id); 92 struct tcf_police_params *new; 93 bool exists = false; 94 int size; 95 96 if (nla == NULL) 97 return -EINVAL; 98 99 err = nla_parse_nested(tb, TCA_POLICE_MAX, nla, police_policy, NULL); 100 if (err < 0) 101 return err; 102 103 if (tb[TCA_POLICE_TBF] == NULL) 104 return -EINVAL; 105 size = nla_len(tb[TCA_POLICE_TBF]); 106 if (size != sizeof(*parm) && size != sizeof(struct tc_police_compat)) 107 return -EINVAL; 108 109 parm = nla_data(tb[TCA_POLICE_TBF]); 110 err = tcf_idr_check_alloc(tn, &parm->index, a, bind); 111 if (err < 0) 112 return err; 113 exists = err; 114 if (exists && bind) 115 return 0; 116 117 if (!exists) { 118 ret = tcf_idr_create(tn, parm->index, NULL, a, 119 &act_police_ops, bind, true); 120 if (ret) { 121 tcf_idr_cleanup(tn, parm->index); 122 return ret; 123 } 124 ret = ACT_P_CREATED; 125 } else if (!ovr) { 126 tcf_idr_release(*a, bind); 127 return -EEXIST; 128 } 129 130 police = to_police(*a); 131 if (parm->rate.rate) { 132 err = -ENOMEM; 133 R_tab = qdisc_get_rtab(&parm->rate, tb[TCA_POLICE_RATE], NULL); 134 if (R_tab == NULL) 135 goto failure; 136 137 if (parm->peakrate.rate) { 138 P_tab = qdisc_get_rtab(&parm->peakrate, 139 tb[TCA_POLICE_PEAKRATE], NULL); 140 if (P_tab == NULL) 141 goto failure; 142 } 143 } 144 145 if (est) { 146 err = gen_replace_estimator(&police->tcf_bstats, 147 police->common.cpu_bstats, 148 &police->tcf_rate_est, 149 &police->tcf_lock, 150 NULL, est); 151 if (err) 152 goto failure; 153 } else if (tb[TCA_POLICE_AVRATE] && 154 (ret == ACT_P_CREATED || 155 !gen_estimator_active(&police->tcf_rate_est))) { 156 err = -EINVAL; 157 goto failure; 158 } 159 160 new = kzalloc(sizeof(*new), GFP_KERNEL); 161 if (unlikely(!new)) { 162 err = -ENOMEM; 163 goto failure; 164 } 165 166 /* No failure allowed after this point */ 167 new->tcfp_mtu = parm->mtu; 168 if (!new->tcfp_mtu) { 169 new->tcfp_mtu = ~0; 170 if (R_tab) 171 new->tcfp_mtu = 255 << R_tab->rate.cell_log; 172 } 173 if (R_tab) { 174 new->rate_present = true; 175 psched_ratecfg_precompute(&new->rate, &R_tab->rate, 0); 176 qdisc_put_rtab(R_tab); 177 } else { 178 new->rate_present = false; 179 } 180 if (P_tab) { 181 new->peak_present = true; 182 psched_ratecfg_precompute(&new->peak, &P_tab->rate, 0); 183 qdisc_put_rtab(P_tab); 184 } else { 185 new->peak_present = false; 186 } 187 188 new->tcfp_burst = PSCHED_TICKS2NS(parm->burst); 189 new->tcfp_toks = new->tcfp_burst; 190 if (new->peak_present) { 191 new->tcfp_mtu_ptoks = (s64)psched_l2t_ns(&new->peak, 192 new->tcfp_mtu); 193 new->tcfp_ptoks = new->tcfp_mtu_ptoks; 194 } 195 196 if (tb[TCA_POLICE_AVRATE]) 197 new->tcfp_ewma_rate = nla_get_u32(tb[TCA_POLICE_AVRATE]); 198 199 if (tb[TCA_POLICE_RESULT]) { 200 new->tcfp_result = nla_get_u32(tb[TCA_POLICE_RESULT]); 201 if (TC_ACT_EXT_CMP(new->tcfp_result, TC_ACT_GOTO_CHAIN)) { 202 NL_SET_ERR_MSG(extack, 203 "goto chain not allowed on fallback"); 204 err = -EINVAL; 205 goto failure; 206 } 207 } 208 209 spin_lock_bh(&police->tcf_lock); 210 new->tcfp_t_c = ktime_get_ns(); 211 police->tcf_action = parm->action; 212 rcu_swap_protected(police->params, 213 new, 214 lockdep_is_held(&police->tcf_lock)); 215 spin_unlock_bh(&police->tcf_lock); 216 217 if (new) 218 kfree_rcu(new, rcu); 219 220 if (ret == ACT_P_CREATED) 221 tcf_idr_insert(tn, *a); 222 return ret; 223 224 failure: 225 qdisc_put_rtab(P_tab); 226 qdisc_put_rtab(R_tab); 227 tcf_idr_release(*a, bind); 228 return err; 229 } 230 231 static int tcf_police_act(struct sk_buff *skb, const struct tc_action *a, 232 struct tcf_result *res) 233 { 234 struct tcf_police *police = to_police(a); 235 struct tcf_police_params *p; 236 s64 now, toks, ptoks = 0; 237 int ret; 238 239 tcf_lastuse_update(&police->tcf_tm); 240 bstats_cpu_update(this_cpu_ptr(police->common.cpu_bstats), skb); 241 242 ret = READ_ONCE(police->tcf_action); 243 p = rcu_dereference_bh(police->params); 244 245 if (p->tcfp_ewma_rate) { 246 struct gnet_stats_rate_est64 sample; 247 248 if (!gen_estimator_read(&police->tcf_rate_est, &sample) || 249 sample.bps >= p->tcfp_ewma_rate) 250 goto inc_overlimits; 251 } 252 253 if (qdisc_pkt_len(skb) <= p->tcfp_mtu) { 254 if (!p->rate_present) { 255 ret = p->tcfp_result; 256 goto end; 257 } 258 259 now = ktime_get_ns(); 260 toks = min_t(s64, now - p->tcfp_t_c, p->tcfp_burst); 261 if (p->peak_present) { 262 ptoks = toks + p->tcfp_ptoks; 263 if (ptoks > p->tcfp_mtu_ptoks) 264 ptoks = p->tcfp_mtu_ptoks; 265 ptoks -= (s64)psched_l2t_ns(&p->peak, 266 qdisc_pkt_len(skb)); 267 } 268 toks += p->tcfp_toks; 269 if (toks > p->tcfp_burst) 270 toks = p->tcfp_burst; 271 toks -= (s64)psched_l2t_ns(&p->rate, qdisc_pkt_len(skb)); 272 if ((toks|ptoks) >= 0) { 273 p->tcfp_t_c = now; 274 p->tcfp_toks = toks; 275 p->tcfp_ptoks = ptoks; 276 ret = p->tcfp_result; 277 goto inc_drops; 278 } 279 } 280 281 inc_overlimits: 282 qstats_overlimit_inc(this_cpu_ptr(police->common.cpu_qstats)); 283 inc_drops: 284 if (ret == TC_ACT_SHOT) 285 qstats_drop_inc(this_cpu_ptr(police->common.cpu_qstats)); 286 end: 287 return ret; 288 } 289 290 static void tcf_police_cleanup(struct tc_action *a) 291 { 292 struct tcf_police *police = to_police(a); 293 struct tcf_police_params *p; 294 295 p = rcu_dereference_protected(police->params, 1); 296 if (p) 297 kfree_rcu(p, rcu); 298 } 299 300 static int tcf_police_dump(struct sk_buff *skb, struct tc_action *a, 301 int bind, int ref) 302 { 303 unsigned char *b = skb_tail_pointer(skb); 304 struct tcf_police *police = to_police(a); 305 struct tcf_police_params *p; 306 struct tc_police opt = { 307 .index = police->tcf_index, 308 .refcnt = refcount_read(&police->tcf_refcnt) - ref, 309 .bindcnt = atomic_read(&police->tcf_bindcnt) - bind, 310 }; 311 struct tcf_t t; 312 313 spin_lock_bh(&police->tcf_lock); 314 opt.action = police->tcf_action; 315 p = rcu_dereference_protected(police->params, 316 lockdep_is_held(&police->tcf_lock)); 317 opt.mtu = p->tcfp_mtu; 318 opt.burst = PSCHED_NS2TICKS(p->tcfp_burst); 319 if (p->rate_present) 320 psched_ratecfg_getrate(&opt.rate, &p->rate); 321 if (p->peak_present) 322 psched_ratecfg_getrate(&opt.peakrate, &p->peak); 323 if (nla_put(skb, TCA_POLICE_TBF, sizeof(opt), &opt)) 324 goto nla_put_failure; 325 if (p->tcfp_result && 326 nla_put_u32(skb, TCA_POLICE_RESULT, p->tcfp_result)) 327 goto nla_put_failure; 328 if (p->tcfp_ewma_rate && 329 nla_put_u32(skb, TCA_POLICE_AVRATE, p->tcfp_ewma_rate)) 330 goto nla_put_failure; 331 332 t.install = jiffies_to_clock_t(jiffies - police->tcf_tm.install); 333 t.lastuse = jiffies_to_clock_t(jiffies - police->tcf_tm.lastuse); 334 t.firstuse = jiffies_to_clock_t(jiffies - police->tcf_tm.firstuse); 335 t.expires = jiffies_to_clock_t(police->tcf_tm.expires); 336 if (nla_put_64bit(skb, TCA_POLICE_TM, sizeof(t), &t, TCA_POLICE_PAD)) 337 goto nla_put_failure; 338 spin_unlock_bh(&police->tcf_lock); 339 340 return skb->len; 341 342 nla_put_failure: 343 spin_unlock_bh(&police->tcf_lock); 344 nlmsg_trim(skb, b); 345 return -1; 346 } 347 348 static int tcf_police_search(struct net *net, struct tc_action **a, u32 index) 349 { 350 struct tc_action_net *tn = net_generic(net, police_net_id); 351 352 return tcf_idr_search(tn, a, index); 353 } 354 355 MODULE_AUTHOR("Alexey Kuznetsov"); 356 MODULE_DESCRIPTION("Policing actions"); 357 MODULE_LICENSE("GPL"); 358 359 static struct tc_action_ops act_police_ops = { 360 .kind = "police", 361 .type = TCA_ID_POLICE, 362 .owner = THIS_MODULE, 363 .act = tcf_police_act, 364 .dump = tcf_police_dump, 365 .init = tcf_police_init, 366 .walk = tcf_police_walker, 367 .lookup = tcf_police_search, 368 .cleanup = tcf_police_cleanup, 369 .size = sizeof(struct tcf_police), 370 }; 371 372 static __net_init int police_init_net(struct net *net) 373 { 374 struct tc_action_net *tn = net_generic(net, police_net_id); 375 376 return tc_action_net_init(tn, &act_police_ops); 377 } 378 379 static void __net_exit police_exit_net(struct list_head *net_list) 380 { 381 tc_action_net_exit(net_list, police_net_id); 382 } 383 384 static struct pernet_operations police_net_ops = { 385 .init = police_init_net, 386 .exit_batch = police_exit_net, 387 .id = &police_net_id, 388 .size = sizeof(struct tc_action_net), 389 }; 390 391 static int __init police_init_module(void) 392 { 393 return tcf_register_action(&act_police_ops, &police_net_ops); 394 } 395 396 static void __exit police_cleanup_module(void) 397 { 398 tcf_unregister_action(&act_police_ops, &police_net_ops); 399 } 400 401 module_init(police_init_module); 402 module_exit(police_cleanup_module); 403