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 { 26 struct tcf_common common; 27 int tcfp_result; 28 u32 tcfp_ewma_rate; 29 s64 tcfp_burst; 30 u32 tcfp_mtu; 31 s64 tcfp_toks; 32 s64 tcfp_ptoks; 33 s64 tcfp_mtu_ptoks; 34 s64 tcfp_t_c; 35 struct psched_ratecfg rate; 36 bool rate_present; 37 struct psched_ratecfg peak; 38 bool peak_present; 39 }; 40 #define to_police(pc) \ 41 container_of(pc->priv, struct tcf_police, common) 42 43 #define POL_TAB_MASK 15 44 45 /* old policer structure from before tc actions */ 46 struct tc_police_compat { 47 u32 index; 48 int action; 49 u32 limit; 50 u32 burst; 51 u32 mtu; 52 struct tc_ratespec rate; 53 struct tc_ratespec peakrate; 54 }; 55 56 /* Each policer is serialized by its individual spinlock */ 57 58 static int police_net_id; 59 60 static int tcf_act_police_walker(struct net *net, struct sk_buff *skb, 61 struct netlink_callback *cb, int type, 62 struct tc_action *a) 63 { 64 struct tc_action_net *tn = net_generic(net, police_net_id); 65 struct tcf_hashinfo *hinfo = tn->hinfo; 66 struct hlist_head *head; 67 struct tcf_common *p; 68 int err = 0, index = -1, i = 0, s_i = 0, n_i = 0; 69 struct nlattr *nest; 70 71 spin_lock_bh(&hinfo->lock); 72 73 s_i = cb->args[0]; 74 75 for (i = 0; i < (POL_TAB_MASK + 1); i++) { 76 head = &hinfo->htab[tcf_hash(i, POL_TAB_MASK)]; 77 78 hlist_for_each_entry_rcu(p, head, tcfc_head) { 79 index++; 80 if (index < s_i) 81 continue; 82 a->priv = p; 83 a->order = index; 84 nest = nla_nest_start(skb, a->order); 85 if (nest == NULL) 86 goto nla_put_failure; 87 if (type == RTM_DELACTION) 88 err = tcf_action_dump_1(skb, a, 0, 1); 89 else 90 err = tcf_action_dump_1(skb, a, 0, 0); 91 if (err < 0) { 92 index--; 93 nla_nest_cancel(skb, nest); 94 goto done; 95 } 96 nla_nest_end(skb, nest); 97 n_i++; 98 } 99 } 100 done: 101 spin_unlock_bh(&hinfo->lock); 102 if (n_i) 103 cb->args[0] += n_i; 104 return n_i; 105 106 nla_put_failure: 107 nla_nest_cancel(skb, nest); 108 goto done; 109 } 110 111 static const struct nla_policy police_policy[TCA_POLICE_MAX + 1] = { 112 [TCA_POLICE_RATE] = { .len = TC_RTAB_SIZE }, 113 [TCA_POLICE_PEAKRATE] = { .len = TC_RTAB_SIZE }, 114 [TCA_POLICE_AVRATE] = { .type = NLA_U32 }, 115 [TCA_POLICE_RESULT] = { .type = NLA_U32 }, 116 }; 117 118 static int tcf_act_police_locate(struct net *net, struct nlattr *nla, 119 struct nlattr *est, struct tc_action *a, 120 int ovr, int bind) 121 { 122 int ret = 0, err; 123 struct nlattr *tb[TCA_POLICE_MAX + 1]; 124 struct tc_police *parm; 125 struct tcf_police *police; 126 struct qdisc_rate_table *R_tab = NULL, *P_tab = NULL; 127 struct tc_action_net *tn = net_generic(net, police_net_id); 128 int size; 129 130 if (nla == NULL) 131 return -EINVAL; 132 133 err = nla_parse_nested(tb, TCA_POLICE_MAX, nla, police_policy); 134 if (err < 0) 135 return err; 136 137 if (tb[TCA_POLICE_TBF] == NULL) 138 return -EINVAL; 139 size = nla_len(tb[TCA_POLICE_TBF]); 140 if (size != sizeof(*parm) && size != sizeof(struct tc_police_compat)) 141 return -EINVAL; 142 parm = nla_data(tb[TCA_POLICE_TBF]); 143 144 if (parm->index) { 145 if (tcf_hash_search(tn, a, parm->index)) { 146 police = to_police(a); 147 if (bind) { 148 police->tcf_bindcnt += 1; 149 police->tcf_refcnt += 1; 150 return 0; 151 } 152 if (ovr) 153 goto override; 154 /* not replacing */ 155 return -EEXIST; 156 } 157 } else { 158 ret = tcf_hash_create(tn, parm->index, NULL, a, 159 sizeof(*police), bind, false); 160 if (ret) 161 return ret; 162 ret = ACT_P_CREATED; 163 } 164 165 police = to_police(a); 166 override: 167 if (parm->rate.rate) { 168 err = -ENOMEM; 169 R_tab = qdisc_get_rtab(&parm->rate, tb[TCA_POLICE_RATE]); 170 if (R_tab == NULL) 171 goto failure; 172 173 if (parm->peakrate.rate) { 174 P_tab = qdisc_get_rtab(&parm->peakrate, 175 tb[TCA_POLICE_PEAKRATE]); 176 if (P_tab == NULL) 177 goto failure; 178 } 179 } 180 181 spin_lock_bh(&police->tcf_lock); 182 if (est) { 183 err = gen_replace_estimator(&police->tcf_bstats, NULL, 184 &police->tcf_rate_est, 185 &police->tcf_lock, est); 186 if (err) 187 goto failure_unlock; 188 } else if (tb[TCA_POLICE_AVRATE] && 189 (ret == ACT_P_CREATED || 190 !gen_estimator_active(&police->tcf_bstats, 191 &police->tcf_rate_est))) { 192 err = -EINVAL; 193 goto failure_unlock; 194 } 195 196 /* No failure allowed after this point */ 197 police->tcfp_mtu = parm->mtu; 198 if (police->tcfp_mtu == 0) { 199 police->tcfp_mtu = ~0; 200 if (R_tab) 201 police->tcfp_mtu = 255 << R_tab->rate.cell_log; 202 } 203 if (R_tab) { 204 police->rate_present = true; 205 psched_ratecfg_precompute(&police->rate, &R_tab->rate, 0); 206 qdisc_put_rtab(R_tab); 207 } else { 208 police->rate_present = false; 209 } 210 if (P_tab) { 211 police->peak_present = true; 212 psched_ratecfg_precompute(&police->peak, &P_tab->rate, 0); 213 qdisc_put_rtab(P_tab); 214 } else { 215 police->peak_present = false; 216 } 217 218 if (tb[TCA_POLICE_RESULT]) 219 police->tcfp_result = nla_get_u32(tb[TCA_POLICE_RESULT]); 220 police->tcfp_burst = PSCHED_TICKS2NS(parm->burst); 221 police->tcfp_toks = police->tcfp_burst; 222 if (police->peak_present) { 223 police->tcfp_mtu_ptoks = (s64) psched_l2t_ns(&police->peak, 224 police->tcfp_mtu); 225 police->tcfp_ptoks = police->tcfp_mtu_ptoks; 226 } 227 police->tcf_action = parm->action; 228 229 if (tb[TCA_POLICE_AVRATE]) 230 police->tcfp_ewma_rate = nla_get_u32(tb[TCA_POLICE_AVRATE]); 231 232 spin_unlock_bh(&police->tcf_lock); 233 if (ret != ACT_P_CREATED) 234 return ret; 235 236 police->tcfp_t_c = ktime_get_ns(); 237 tcf_hash_insert(tn, a); 238 239 return ret; 240 241 failure_unlock: 242 spin_unlock_bh(&police->tcf_lock); 243 failure: 244 qdisc_put_rtab(P_tab); 245 qdisc_put_rtab(R_tab); 246 if (ret == ACT_P_CREATED) 247 tcf_hash_cleanup(a, est); 248 return err; 249 } 250 251 static int tcf_act_police(struct sk_buff *skb, const struct tc_action *a, 252 struct tcf_result *res) 253 { 254 struct tcf_police *police = a->priv; 255 s64 now; 256 s64 toks; 257 s64 ptoks = 0; 258 259 spin_lock(&police->tcf_lock); 260 261 bstats_update(&police->tcf_bstats, skb); 262 tcf_lastuse_update(&police->tcf_tm); 263 264 if (police->tcfp_ewma_rate && 265 police->tcf_rate_est.bps >= police->tcfp_ewma_rate) { 266 police->tcf_qstats.overlimits++; 267 if (police->tcf_action == TC_ACT_SHOT) 268 police->tcf_qstats.drops++; 269 spin_unlock(&police->tcf_lock); 270 return police->tcf_action; 271 } 272 273 if (qdisc_pkt_len(skb) <= police->tcfp_mtu) { 274 if (!police->rate_present) { 275 spin_unlock(&police->tcf_lock); 276 return police->tcfp_result; 277 } 278 279 now = ktime_get_ns(); 280 toks = min_t(s64, now - police->tcfp_t_c, 281 police->tcfp_burst); 282 if (police->peak_present) { 283 ptoks = toks + police->tcfp_ptoks; 284 if (ptoks > police->tcfp_mtu_ptoks) 285 ptoks = police->tcfp_mtu_ptoks; 286 ptoks -= (s64) psched_l2t_ns(&police->peak, 287 qdisc_pkt_len(skb)); 288 } 289 toks += police->tcfp_toks; 290 if (toks > police->tcfp_burst) 291 toks = police->tcfp_burst; 292 toks -= (s64) psched_l2t_ns(&police->rate, qdisc_pkt_len(skb)); 293 if ((toks|ptoks) >= 0) { 294 police->tcfp_t_c = now; 295 police->tcfp_toks = toks; 296 police->tcfp_ptoks = ptoks; 297 spin_unlock(&police->tcf_lock); 298 return police->tcfp_result; 299 } 300 } 301 302 police->tcf_qstats.overlimits++; 303 if (police->tcf_action == TC_ACT_SHOT) 304 police->tcf_qstats.drops++; 305 spin_unlock(&police->tcf_lock); 306 return police->tcf_action; 307 } 308 309 static int 310 tcf_act_police_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref) 311 { 312 unsigned char *b = skb_tail_pointer(skb); 313 struct tcf_police *police = a->priv; 314 struct tc_police opt = { 315 .index = police->tcf_index, 316 .action = police->tcf_action, 317 .mtu = police->tcfp_mtu, 318 .burst = PSCHED_NS2TICKS(police->tcfp_burst), 319 .refcnt = police->tcf_refcnt - ref, 320 .bindcnt = police->tcf_bindcnt - bind, 321 }; 322 struct tcf_t t; 323 324 if (police->rate_present) 325 psched_ratecfg_getrate(&opt.rate, &police->rate); 326 if (police->peak_present) 327 psched_ratecfg_getrate(&opt.peakrate, &police->peak); 328 if (nla_put(skb, TCA_POLICE_TBF, sizeof(opt), &opt)) 329 goto nla_put_failure; 330 if (police->tcfp_result && 331 nla_put_u32(skb, TCA_POLICE_RESULT, police->tcfp_result)) 332 goto nla_put_failure; 333 if (police->tcfp_ewma_rate && 334 nla_put_u32(skb, TCA_POLICE_AVRATE, police->tcfp_ewma_rate)) 335 goto nla_put_failure; 336 337 t.install = jiffies_to_clock_t(jiffies - police->tcf_tm.install); 338 t.lastuse = jiffies_to_clock_t(jiffies - police->tcf_tm.lastuse); 339 t.expires = jiffies_to_clock_t(police->tcf_tm.expires); 340 if (nla_put_64bit(skb, TCA_POLICE_TM, sizeof(t), &t, TCA_POLICE_PAD)) 341 goto nla_put_failure; 342 343 return skb->len; 344 345 nla_put_failure: 346 nlmsg_trim(skb, b); 347 return -1; 348 } 349 350 static int tcf_police_search(struct net *net, struct tc_action *a, u32 index) 351 { 352 struct tc_action_net *tn = net_generic(net, police_net_id); 353 354 return tcf_hash_search(tn, a, index); 355 } 356 357 MODULE_AUTHOR("Alexey Kuznetsov"); 358 MODULE_DESCRIPTION("Policing actions"); 359 MODULE_LICENSE("GPL"); 360 361 static struct tc_action_ops act_police_ops = { 362 .kind = "police", 363 .type = TCA_ID_POLICE, 364 .owner = THIS_MODULE, 365 .act = tcf_act_police, 366 .dump = tcf_act_police_dump, 367 .init = tcf_act_police_locate, 368 .walk = tcf_act_police_walker, 369 .lookup = tcf_police_search, 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, POL_TAB_MASK); 377 } 378 379 static void __net_exit police_exit_net(struct net *net) 380 { 381 struct tc_action_net *tn = net_generic(net, police_net_id); 382 383 tc_action_net_exit(tn); 384 } 385 386 static struct pernet_operations police_net_ops = { 387 .init = police_init_net, 388 .exit = police_exit_net, 389 .id = &police_net_id, 390 .size = sizeof(struct tc_action_net), 391 }; 392 393 static int __init 394 police_init_module(void) 395 { 396 return tcf_register_action(&act_police_ops, &police_net_ops); 397 } 398 399 static void __exit 400 police_cleanup_module(void) 401 { 402 tcf_unregister_action(&act_police_ops, &police_net_ops); 403 } 404 405 module_init(police_init_module); 406 module_exit(police_cleanup_module); 407