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 tc_action 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 41 #define to_police(pc) ((struct tcf_police *)pc) 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 static struct tc_action_ops act_police_ops; 60 61 static int tcf_act_police_walker(struct net *net, struct sk_buff *skb, 62 struct netlink_callback *cb, int type, 63 const struct tc_action_ops *ops) 64 { 65 struct tc_action_net *tn = net_generic(net, police_net_id); 66 struct tcf_hashinfo *hinfo = tn->hinfo; 67 int err = 0, index = -1, i = 0, s_i = 0, n_i = 0; 68 struct nlattr *nest; 69 70 spin_lock_bh(&hinfo->lock); 71 72 s_i = cb->args[0]; 73 74 for (i = 0; i < (POL_TAB_MASK + 1); i++) { 75 struct hlist_head *head; 76 struct tc_action *p; 77 78 head = &hinfo->htab[tcf_hash(i, POL_TAB_MASK)]; 79 80 hlist_for_each_entry_rcu(p, head, tcfa_head) { 81 index++; 82 if (index < s_i) 83 continue; 84 nest = nla_nest_start(skb, index); 85 if (nest == NULL) 86 goto nla_put_failure; 87 if (type == RTM_DELACTION) 88 err = tcf_action_dump_1(skb, p, 0, 1); 89 else 90 err = tcf_action_dump_1(skb, p, 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_init(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_check(tn, parm->index, a, bind)) { 146 if (ovr) 147 goto override; 148 /* not replacing */ 149 return -EEXIST; 150 } 151 } else { 152 ret = tcf_hash_create(tn, parm->index, NULL, a, 153 &act_police_ops, bind, false); 154 if (ret) 155 return ret; 156 ret = ACT_P_CREATED; 157 } 158 159 override: 160 police = to_police(*a); 161 if (parm->rate.rate) { 162 err = -ENOMEM; 163 R_tab = qdisc_get_rtab(&parm->rate, tb[TCA_POLICE_RATE]); 164 if (R_tab == NULL) 165 goto failure; 166 167 if (parm->peakrate.rate) { 168 P_tab = qdisc_get_rtab(&parm->peakrate, 169 tb[TCA_POLICE_PEAKRATE]); 170 if (P_tab == NULL) 171 goto failure; 172 } 173 } 174 175 spin_lock_bh(&police->tcf_lock); 176 if (est) { 177 err = gen_replace_estimator(&police->tcf_bstats, NULL, 178 &police->tcf_rate_est, 179 &police->tcf_lock, 180 NULL, est); 181 if (err) 182 goto failure_unlock; 183 } else if (tb[TCA_POLICE_AVRATE] && 184 (ret == ACT_P_CREATED || 185 !gen_estimator_active(&police->tcf_bstats, 186 &police->tcf_rate_est))) { 187 err = -EINVAL; 188 goto failure_unlock; 189 } 190 191 /* No failure allowed after this point */ 192 police->tcfp_mtu = parm->mtu; 193 if (police->tcfp_mtu == 0) { 194 police->tcfp_mtu = ~0; 195 if (R_tab) 196 police->tcfp_mtu = 255 << R_tab->rate.cell_log; 197 } 198 if (R_tab) { 199 police->rate_present = true; 200 psched_ratecfg_precompute(&police->rate, &R_tab->rate, 0); 201 qdisc_put_rtab(R_tab); 202 } else { 203 police->rate_present = false; 204 } 205 if (P_tab) { 206 police->peak_present = true; 207 psched_ratecfg_precompute(&police->peak, &P_tab->rate, 0); 208 qdisc_put_rtab(P_tab); 209 } else { 210 police->peak_present = false; 211 } 212 213 if (tb[TCA_POLICE_RESULT]) 214 police->tcfp_result = nla_get_u32(tb[TCA_POLICE_RESULT]); 215 police->tcfp_burst = PSCHED_TICKS2NS(parm->burst); 216 police->tcfp_toks = police->tcfp_burst; 217 if (police->peak_present) { 218 police->tcfp_mtu_ptoks = (s64) psched_l2t_ns(&police->peak, 219 police->tcfp_mtu); 220 police->tcfp_ptoks = police->tcfp_mtu_ptoks; 221 } 222 police->tcf_action = parm->action; 223 224 if (tb[TCA_POLICE_AVRATE]) 225 police->tcfp_ewma_rate = nla_get_u32(tb[TCA_POLICE_AVRATE]); 226 227 spin_unlock_bh(&police->tcf_lock); 228 if (ret != ACT_P_CREATED) 229 return ret; 230 231 police->tcfp_t_c = ktime_get_ns(); 232 tcf_hash_insert(tn, *a); 233 234 return ret; 235 236 failure_unlock: 237 spin_unlock_bh(&police->tcf_lock); 238 failure: 239 qdisc_put_rtab(P_tab); 240 qdisc_put_rtab(R_tab); 241 if (ret == ACT_P_CREATED) 242 tcf_hash_cleanup(*a, est); 243 return err; 244 } 245 246 static int tcf_act_police(struct sk_buff *skb, const struct tc_action *a, 247 struct tcf_result *res) 248 { 249 struct tcf_police *police = to_police(a); 250 s64 now; 251 s64 toks; 252 s64 ptoks = 0; 253 254 spin_lock(&police->tcf_lock); 255 256 bstats_update(&police->tcf_bstats, skb); 257 tcf_lastuse_update(&police->tcf_tm); 258 259 if (police->tcfp_ewma_rate && 260 police->tcf_rate_est.bps >= police->tcfp_ewma_rate) { 261 police->tcf_qstats.overlimits++; 262 if (police->tcf_action == TC_ACT_SHOT) 263 police->tcf_qstats.drops++; 264 spin_unlock(&police->tcf_lock); 265 return police->tcf_action; 266 } 267 268 if (qdisc_pkt_len(skb) <= police->tcfp_mtu) { 269 if (!police->rate_present) { 270 spin_unlock(&police->tcf_lock); 271 return police->tcfp_result; 272 } 273 274 now = ktime_get_ns(); 275 toks = min_t(s64, now - police->tcfp_t_c, 276 police->tcfp_burst); 277 if (police->peak_present) { 278 ptoks = toks + police->tcfp_ptoks; 279 if (ptoks > police->tcfp_mtu_ptoks) 280 ptoks = police->tcfp_mtu_ptoks; 281 ptoks -= (s64) psched_l2t_ns(&police->peak, 282 qdisc_pkt_len(skb)); 283 } 284 toks += police->tcfp_toks; 285 if (toks > police->tcfp_burst) 286 toks = police->tcfp_burst; 287 toks -= (s64) psched_l2t_ns(&police->rate, qdisc_pkt_len(skb)); 288 if ((toks|ptoks) >= 0) { 289 police->tcfp_t_c = now; 290 police->tcfp_toks = toks; 291 police->tcfp_ptoks = ptoks; 292 spin_unlock(&police->tcf_lock); 293 return police->tcfp_result; 294 } 295 } 296 297 police->tcf_qstats.overlimits++; 298 if (police->tcf_action == TC_ACT_SHOT) 299 police->tcf_qstats.drops++; 300 spin_unlock(&police->tcf_lock); 301 return police->tcf_action; 302 } 303 304 static int 305 tcf_act_police_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref) 306 { 307 unsigned char *b = skb_tail_pointer(skb); 308 struct tcf_police *police = to_police(a); 309 struct tc_police opt = { 310 .index = police->tcf_index, 311 .action = police->tcf_action, 312 .mtu = police->tcfp_mtu, 313 .burst = PSCHED_NS2TICKS(police->tcfp_burst), 314 .refcnt = police->tcf_refcnt - ref, 315 .bindcnt = police->tcf_bindcnt - bind, 316 }; 317 struct tcf_t t; 318 319 if (police->rate_present) 320 psched_ratecfg_getrate(&opt.rate, &police->rate); 321 if (police->peak_present) 322 psched_ratecfg_getrate(&opt.peakrate, &police->peak); 323 if (nla_put(skb, TCA_POLICE_TBF, sizeof(opt), &opt)) 324 goto nla_put_failure; 325 if (police->tcfp_result && 326 nla_put_u32(skb, TCA_POLICE_RESULT, police->tcfp_result)) 327 goto nla_put_failure; 328 if (police->tcfp_ewma_rate && 329 nla_put_u32(skb, TCA_POLICE_AVRATE, police->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; 338 339 return skb->len; 340 341 nla_put_failure: 342 nlmsg_trim(skb, b); 343 return -1; 344 } 345 346 static int tcf_police_search(struct net *net, struct tc_action **a, u32 index) 347 { 348 struct tc_action_net *tn = net_generic(net, police_net_id); 349 350 return tcf_hash_search(tn, a, index); 351 } 352 353 MODULE_AUTHOR("Alexey Kuznetsov"); 354 MODULE_DESCRIPTION("Policing actions"); 355 MODULE_LICENSE("GPL"); 356 357 static struct tc_action_ops act_police_ops = { 358 .kind = "police", 359 .type = TCA_ID_POLICE, 360 .owner = THIS_MODULE, 361 .act = tcf_act_police, 362 .dump = tcf_act_police_dump, 363 .init = tcf_act_police_init, 364 .walk = tcf_act_police_walker, 365 .lookup = tcf_police_search, 366 .size = sizeof(struct tcf_police), 367 }; 368 369 static __net_init int police_init_net(struct net *net) 370 { 371 struct tc_action_net *tn = net_generic(net, police_net_id); 372 373 return tc_action_net_init(tn, &act_police_ops, POL_TAB_MASK); 374 } 375 376 static void __net_exit police_exit_net(struct net *net) 377 { 378 struct tc_action_net *tn = net_generic(net, police_net_id); 379 380 tc_action_net_exit(tn); 381 } 382 383 static struct pernet_operations police_net_ops = { 384 .init = police_init_net, 385 .exit = police_exit_net, 386 .id = &police_net_id, 387 .size = sizeof(struct tc_action_net), 388 }; 389 390 static int __init 391 police_init_module(void) 392 { 393 return tcf_register_action(&act_police_ops, &police_net_ops); 394 } 395 396 static void __exit 397 police_cleanup_module(void) 398 { 399 tcf_unregister_action(&act_police_ops, &police_net_ops); 400 } 401 402 module_init(police_init_module); 403 module_exit(police_cleanup_module); 404