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 if (tb[TCA_POLICE_RESULT]) 189 new->tcfp_result = nla_get_u32(tb[TCA_POLICE_RESULT]); 190 new->tcfp_burst = PSCHED_TICKS2NS(parm->burst); 191 new->tcfp_toks = new->tcfp_burst; 192 if (new->peak_present) { 193 new->tcfp_mtu_ptoks = (s64)psched_l2t_ns(&new->peak, 194 new->tcfp_mtu); 195 new->tcfp_ptoks = new->tcfp_mtu_ptoks; 196 } 197 198 if (tb[TCA_POLICE_AVRATE]) 199 new->tcfp_ewma_rate = nla_get_u32(tb[TCA_POLICE_AVRATE]); 200 201 spin_lock_bh(&police->tcf_lock); 202 new->tcfp_t_c = ktime_get_ns(); 203 police->tcf_action = parm->action; 204 rcu_swap_protected(police->params, 205 new, 206 lockdep_is_held(&police->tcf_lock)); 207 spin_unlock_bh(&police->tcf_lock); 208 209 if (new) 210 kfree_rcu(new, rcu); 211 212 if (ret == ACT_P_CREATED) 213 tcf_idr_insert(tn, *a); 214 return ret; 215 216 failure: 217 qdisc_put_rtab(P_tab); 218 qdisc_put_rtab(R_tab); 219 tcf_idr_release(*a, bind); 220 return err; 221 } 222 223 static int tcf_police_act(struct sk_buff *skb, const struct tc_action *a, 224 struct tcf_result *res) 225 { 226 struct tcf_police *police = to_police(a); 227 struct tcf_police_params *p; 228 s64 now, toks, ptoks = 0; 229 int ret; 230 231 tcf_lastuse_update(&police->tcf_tm); 232 bstats_cpu_update(this_cpu_ptr(police->common.cpu_bstats), skb); 233 234 ret = READ_ONCE(police->tcf_action); 235 p = rcu_dereference_bh(police->params); 236 237 if (p->tcfp_ewma_rate) { 238 struct gnet_stats_rate_est64 sample; 239 240 if (!gen_estimator_read(&police->tcf_rate_est, &sample) || 241 sample.bps >= p->tcfp_ewma_rate) 242 goto inc_overlimits; 243 } 244 245 if (qdisc_pkt_len(skb) <= p->tcfp_mtu) { 246 if (!p->rate_present) { 247 ret = p->tcfp_result; 248 goto end; 249 } 250 251 now = ktime_get_ns(); 252 toks = min_t(s64, now - p->tcfp_t_c, p->tcfp_burst); 253 if (p->peak_present) { 254 ptoks = toks + p->tcfp_ptoks; 255 if (ptoks > p->tcfp_mtu_ptoks) 256 ptoks = p->tcfp_mtu_ptoks; 257 ptoks -= (s64)psched_l2t_ns(&p->peak, 258 qdisc_pkt_len(skb)); 259 } 260 toks += p->tcfp_toks; 261 if (toks > p->tcfp_burst) 262 toks = p->tcfp_burst; 263 toks -= (s64)psched_l2t_ns(&p->rate, qdisc_pkt_len(skb)); 264 if ((toks|ptoks) >= 0) { 265 p->tcfp_t_c = now; 266 p->tcfp_toks = toks; 267 p->tcfp_ptoks = ptoks; 268 ret = p->tcfp_result; 269 goto inc_drops; 270 } 271 } 272 273 inc_overlimits: 274 qstats_overlimit_inc(this_cpu_ptr(police->common.cpu_qstats)); 275 inc_drops: 276 if (ret == TC_ACT_SHOT) 277 qstats_drop_inc(this_cpu_ptr(police->common.cpu_qstats)); 278 end: 279 return ret; 280 } 281 282 static void tcf_police_cleanup(struct tc_action *a) 283 { 284 struct tcf_police *police = to_police(a); 285 struct tcf_police_params *p; 286 287 p = rcu_dereference_protected(police->params, 1); 288 if (p) 289 kfree_rcu(p, rcu); 290 } 291 292 static int tcf_police_dump(struct sk_buff *skb, struct tc_action *a, 293 int bind, int ref) 294 { 295 unsigned char *b = skb_tail_pointer(skb); 296 struct tcf_police *police = to_police(a); 297 struct tcf_police_params *p; 298 struct tc_police opt = { 299 .index = police->tcf_index, 300 .refcnt = refcount_read(&police->tcf_refcnt) - ref, 301 .bindcnt = atomic_read(&police->tcf_bindcnt) - bind, 302 }; 303 struct tcf_t t; 304 305 spin_lock_bh(&police->tcf_lock); 306 opt.action = police->tcf_action; 307 p = rcu_dereference_protected(police->params, 308 lockdep_is_held(&police->tcf_lock)); 309 opt.mtu = p->tcfp_mtu; 310 opt.burst = PSCHED_NS2TICKS(p->tcfp_burst); 311 if (p->rate_present) 312 psched_ratecfg_getrate(&opt.rate, &p->rate); 313 if (p->peak_present) 314 psched_ratecfg_getrate(&opt.peakrate, &p->peak); 315 if (nla_put(skb, TCA_POLICE_TBF, sizeof(opt), &opt)) 316 goto nla_put_failure; 317 if (p->tcfp_result && 318 nla_put_u32(skb, TCA_POLICE_RESULT, p->tcfp_result)) 319 goto nla_put_failure; 320 if (p->tcfp_ewma_rate && 321 nla_put_u32(skb, TCA_POLICE_AVRATE, p->tcfp_ewma_rate)) 322 goto nla_put_failure; 323 324 t.install = jiffies_to_clock_t(jiffies - police->tcf_tm.install); 325 t.lastuse = jiffies_to_clock_t(jiffies - police->tcf_tm.lastuse); 326 t.firstuse = jiffies_to_clock_t(jiffies - police->tcf_tm.firstuse); 327 t.expires = jiffies_to_clock_t(police->tcf_tm.expires); 328 if (nla_put_64bit(skb, TCA_POLICE_TM, sizeof(t), &t, TCA_POLICE_PAD)) 329 goto nla_put_failure; 330 spin_unlock_bh(&police->tcf_lock); 331 332 return skb->len; 333 334 nla_put_failure: 335 spin_unlock_bh(&police->tcf_lock); 336 nlmsg_trim(skb, b); 337 return -1; 338 } 339 340 static int tcf_police_search(struct net *net, struct tc_action **a, u32 index) 341 { 342 struct tc_action_net *tn = net_generic(net, police_net_id); 343 344 return tcf_idr_search(tn, a, index); 345 } 346 347 MODULE_AUTHOR("Alexey Kuznetsov"); 348 MODULE_DESCRIPTION("Policing actions"); 349 MODULE_LICENSE("GPL"); 350 351 static struct tc_action_ops act_police_ops = { 352 .kind = "police", 353 .type = TCA_ID_POLICE, 354 .owner = THIS_MODULE, 355 .act = tcf_police_act, 356 .dump = tcf_police_dump, 357 .init = tcf_police_init, 358 .walk = tcf_police_walker, 359 .lookup = tcf_police_search, 360 .cleanup = tcf_police_cleanup, 361 .size = sizeof(struct tcf_police), 362 }; 363 364 static __net_init int police_init_net(struct net *net) 365 { 366 struct tc_action_net *tn = net_generic(net, police_net_id); 367 368 return tc_action_net_init(tn, &act_police_ops); 369 } 370 371 static void __net_exit police_exit_net(struct list_head *net_list) 372 { 373 tc_action_net_exit(net_list, police_net_id); 374 } 375 376 static struct pernet_operations police_net_ops = { 377 .init = police_init_net, 378 .exit_batch = police_exit_net, 379 .id = &police_net_id, 380 .size = sizeof(struct tc_action_net), 381 }; 382 383 static int __init police_init_module(void) 384 { 385 return tcf_register_action(&act_police_ops, &police_net_ops); 386 } 387 388 static void __exit police_cleanup_module(void) 389 { 390 tcf_unregister_action(&act_police_ops, &police_net_ops); 391 } 392 393 module_init(police_init_module); 394 module_exit(police_cleanup_module); 395