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, 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 unsigned int h; 123 int ret = 0, err; 124 struct nlattr *tb[TCA_POLICE_MAX + 1]; 125 struct tc_police *parm; 126 struct tcf_police *police; 127 struct qdisc_rate_table *R_tab = NULL, *P_tab = NULL; 128 struct tc_action_net *tn = net_generic(net, police_net_id); 129 struct tcf_hashinfo *hinfo = tn->hinfo; 130 int size; 131 132 if (nla == NULL) 133 return -EINVAL; 134 135 err = nla_parse_nested(tb, TCA_POLICE_MAX, nla, police_policy); 136 if (err < 0) 137 return err; 138 139 if (tb[TCA_POLICE_TBF] == NULL) 140 return -EINVAL; 141 size = nla_len(tb[TCA_POLICE_TBF]); 142 if (size != sizeof(*parm) && size != sizeof(struct tc_police_compat)) 143 return -EINVAL; 144 parm = nla_data(tb[TCA_POLICE_TBF]); 145 146 if (parm->index) { 147 if (tcf_hash_search(tn, a, parm->index)) { 148 police = to_police(a->priv); 149 if (bind) { 150 police->tcf_bindcnt += 1; 151 police->tcf_refcnt += 1; 152 return 0; 153 } 154 if (ovr) 155 goto override; 156 /* not replacing */ 157 return -EEXIST; 158 } 159 } 160 161 police = kzalloc(sizeof(*police), GFP_KERNEL); 162 if (police == NULL) 163 return -ENOMEM; 164 ret = ACT_P_CREATED; 165 police->tcf_refcnt = 1; 166 spin_lock_init(&police->tcf_lock); 167 if (bind) 168 police->tcf_bindcnt = 1; 169 override: 170 if (parm->rate.rate) { 171 err = -ENOMEM; 172 R_tab = qdisc_get_rtab(&parm->rate, tb[TCA_POLICE_RATE]); 173 if (R_tab == NULL) 174 goto failure; 175 176 if (parm->peakrate.rate) { 177 P_tab = qdisc_get_rtab(&parm->peakrate, 178 tb[TCA_POLICE_PEAKRATE]); 179 if (P_tab == NULL) 180 goto failure; 181 } 182 } 183 184 spin_lock_bh(&police->tcf_lock); 185 if (est) { 186 err = gen_replace_estimator(&police->tcf_bstats, NULL, 187 &police->tcf_rate_est, 188 &police->tcf_lock, est); 189 if (err) 190 goto failure_unlock; 191 } else if (tb[TCA_POLICE_AVRATE] && 192 (ret == ACT_P_CREATED || 193 !gen_estimator_active(&police->tcf_bstats, 194 &police->tcf_rate_est))) { 195 err = -EINVAL; 196 goto failure_unlock; 197 } 198 199 /* No failure allowed after this point */ 200 police->tcfp_mtu = parm->mtu; 201 if (police->tcfp_mtu == 0) { 202 police->tcfp_mtu = ~0; 203 if (R_tab) 204 police->tcfp_mtu = 255 << R_tab->rate.cell_log; 205 } 206 if (R_tab) { 207 police->rate_present = true; 208 psched_ratecfg_precompute(&police->rate, &R_tab->rate, 0); 209 qdisc_put_rtab(R_tab); 210 } else { 211 police->rate_present = false; 212 } 213 if (P_tab) { 214 police->peak_present = true; 215 psched_ratecfg_precompute(&police->peak, &P_tab->rate, 0); 216 qdisc_put_rtab(P_tab); 217 } else { 218 police->peak_present = false; 219 } 220 221 if (tb[TCA_POLICE_RESULT]) 222 police->tcfp_result = nla_get_u32(tb[TCA_POLICE_RESULT]); 223 police->tcfp_burst = PSCHED_TICKS2NS(parm->burst); 224 police->tcfp_toks = police->tcfp_burst; 225 if (police->peak_present) { 226 police->tcfp_mtu_ptoks = (s64) psched_l2t_ns(&police->peak, 227 police->tcfp_mtu); 228 police->tcfp_ptoks = police->tcfp_mtu_ptoks; 229 } 230 police->tcf_action = parm->action; 231 232 if (tb[TCA_POLICE_AVRATE]) 233 police->tcfp_ewma_rate = nla_get_u32(tb[TCA_POLICE_AVRATE]); 234 235 spin_unlock_bh(&police->tcf_lock); 236 if (ret != ACT_P_CREATED) 237 return ret; 238 239 police->tcfp_t_c = ktime_get_ns(); 240 police->tcf_index = parm->index ? parm->index : 241 tcf_hash_new_index(tn); 242 h = tcf_hash(police->tcf_index, POL_TAB_MASK); 243 spin_lock_bh(&hinfo->lock); 244 hlist_add_head(&police->tcf_head, &hinfo->htab[h]); 245 spin_unlock_bh(&hinfo->lock); 246 247 a->priv = police; 248 return ret; 249 250 failure_unlock: 251 spin_unlock_bh(&police->tcf_lock); 252 failure: 253 qdisc_put_rtab(P_tab); 254 qdisc_put_rtab(R_tab); 255 if (ret == ACT_P_CREATED) 256 kfree(police); 257 return err; 258 } 259 260 static int tcf_act_police(struct sk_buff *skb, const struct tc_action *a, 261 struct tcf_result *res) 262 { 263 struct tcf_police *police = a->priv; 264 s64 now; 265 s64 toks; 266 s64 ptoks = 0; 267 268 spin_lock(&police->tcf_lock); 269 270 bstats_update(&police->tcf_bstats, skb); 271 272 if (police->tcfp_ewma_rate && 273 police->tcf_rate_est.bps >= police->tcfp_ewma_rate) { 274 police->tcf_qstats.overlimits++; 275 if (police->tcf_action == TC_ACT_SHOT) 276 police->tcf_qstats.drops++; 277 spin_unlock(&police->tcf_lock); 278 return police->tcf_action; 279 } 280 281 if (qdisc_pkt_len(skb) <= police->tcfp_mtu) { 282 if (!police->rate_present) { 283 spin_unlock(&police->tcf_lock); 284 return police->tcfp_result; 285 } 286 287 now = ktime_get_ns(); 288 toks = min_t(s64, now - police->tcfp_t_c, 289 police->tcfp_burst); 290 if (police->peak_present) { 291 ptoks = toks + police->tcfp_ptoks; 292 if (ptoks > police->tcfp_mtu_ptoks) 293 ptoks = police->tcfp_mtu_ptoks; 294 ptoks -= (s64) psched_l2t_ns(&police->peak, 295 qdisc_pkt_len(skb)); 296 } 297 toks += police->tcfp_toks; 298 if (toks > police->tcfp_burst) 299 toks = police->tcfp_burst; 300 toks -= (s64) psched_l2t_ns(&police->rate, qdisc_pkt_len(skb)); 301 if ((toks|ptoks) >= 0) { 302 police->tcfp_t_c = now; 303 police->tcfp_toks = toks; 304 police->tcfp_ptoks = ptoks; 305 spin_unlock(&police->tcf_lock); 306 return police->tcfp_result; 307 } 308 } 309 310 police->tcf_qstats.overlimits++; 311 if (police->tcf_action == TC_ACT_SHOT) 312 police->tcf_qstats.drops++; 313 spin_unlock(&police->tcf_lock); 314 return police->tcf_action; 315 } 316 317 static int 318 tcf_act_police_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref) 319 { 320 unsigned char *b = skb_tail_pointer(skb); 321 struct tcf_police *police = a->priv; 322 struct tc_police opt = { 323 .index = police->tcf_index, 324 .action = police->tcf_action, 325 .mtu = police->tcfp_mtu, 326 .burst = PSCHED_NS2TICKS(police->tcfp_burst), 327 .refcnt = police->tcf_refcnt - ref, 328 .bindcnt = police->tcf_bindcnt - bind, 329 }; 330 331 if (police->rate_present) 332 psched_ratecfg_getrate(&opt.rate, &police->rate); 333 if (police->peak_present) 334 psched_ratecfg_getrate(&opt.peakrate, &police->peak); 335 if (nla_put(skb, TCA_POLICE_TBF, sizeof(opt), &opt)) 336 goto nla_put_failure; 337 if (police->tcfp_result && 338 nla_put_u32(skb, TCA_POLICE_RESULT, police->tcfp_result)) 339 goto nla_put_failure; 340 if (police->tcfp_ewma_rate && 341 nla_put_u32(skb, TCA_POLICE_AVRATE, police->tcfp_ewma_rate)) 342 goto nla_put_failure; 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