1 /* 2 * net/sched/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 tcf_act_police_walker(struct sk_buff *skb, struct netlink_callback *cb, 59 int type, struct tc_action *a) 60 { 61 struct tcf_hashinfo *hinfo = a->ops->hinfo; 62 struct hlist_head *head; 63 struct tcf_common *p; 64 int err = 0, index = -1, i = 0, s_i = 0, n_i = 0; 65 struct nlattr *nest; 66 67 spin_lock_bh(&hinfo->lock); 68 69 s_i = cb->args[0]; 70 71 for (i = 0; i < (POL_TAB_MASK + 1); i++) { 72 head = &hinfo->htab[tcf_hash(i, POL_TAB_MASK)]; 73 74 hlist_for_each_entry_rcu(p, head, tcfc_head) { 75 index++; 76 if (index < s_i) 77 continue; 78 a->priv = p; 79 a->order = index; 80 nest = nla_nest_start(skb, a->order); 81 if (nest == NULL) 82 goto nla_put_failure; 83 if (type == RTM_DELACTION) 84 err = tcf_action_dump_1(skb, a, 0, 1); 85 else 86 err = tcf_action_dump_1(skb, a, 0, 0); 87 if (err < 0) { 88 index--; 89 nla_nest_cancel(skb, nest); 90 goto done; 91 } 92 nla_nest_end(skb, nest); 93 n_i++; 94 } 95 } 96 done: 97 spin_unlock_bh(&hinfo->lock); 98 if (n_i) 99 cb->args[0] += n_i; 100 return n_i; 101 102 nla_put_failure: 103 nla_nest_cancel(skb, nest); 104 goto done; 105 } 106 107 static const struct nla_policy police_policy[TCA_POLICE_MAX + 1] = { 108 [TCA_POLICE_RATE] = { .len = TC_RTAB_SIZE }, 109 [TCA_POLICE_PEAKRATE] = { .len = TC_RTAB_SIZE }, 110 [TCA_POLICE_AVRATE] = { .type = NLA_U32 }, 111 [TCA_POLICE_RESULT] = { .type = NLA_U32 }, 112 }; 113 114 static int tcf_act_police_locate(struct net *net, struct nlattr *nla, 115 struct nlattr *est, struct tc_action *a, 116 int ovr, int bind) 117 { 118 unsigned int h; 119 int ret = 0, err; 120 struct nlattr *tb[TCA_POLICE_MAX + 1]; 121 struct tc_police *parm; 122 struct tcf_police *police; 123 struct qdisc_rate_table *R_tab = NULL, *P_tab = NULL; 124 struct tcf_hashinfo *hinfo = a->ops->hinfo; 125 int size; 126 127 if (nla == NULL) 128 return -EINVAL; 129 130 err = nla_parse_nested(tb, TCA_POLICE_MAX, nla, police_policy); 131 if (err < 0) 132 return err; 133 134 if (tb[TCA_POLICE_TBF] == NULL) 135 return -EINVAL; 136 size = nla_len(tb[TCA_POLICE_TBF]); 137 if (size != sizeof(*parm) && size != sizeof(struct tc_police_compat)) 138 return -EINVAL; 139 parm = nla_data(tb[TCA_POLICE_TBF]); 140 141 if (parm->index) { 142 if (tcf_hash_search(a, parm->index)) { 143 police = to_police(a->priv); 144 if (bind) { 145 police->tcf_bindcnt += 1; 146 police->tcf_refcnt += 1; 147 return 0; 148 } 149 if (ovr) 150 goto override; 151 /* not replacing */ 152 return -EEXIST; 153 } 154 } 155 156 police = kzalloc(sizeof(*police), GFP_KERNEL); 157 if (police == NULL) 158 return -ENOMEM; 159 ret = ACT_P_CREATED; 160 police->tcf_refcnt = 1; 161 spin_lock_init(&police->tcf_lock); 162 if (bind) 163 police->tcf_bindcnt = 1; 164 override: 165 if (parm->rate.rate) { 166 err = -ENOMEM; 167 R_tab = qdisc_get_rtab(&parm->rate, tb[TCA_POLICE_RATE]); 168 if (R_tab == NULL) 169 goto failure; 170 171 if (parm->peakrate.rate) { 172 P_tab = qdisc_get_rtab(&parm->peakrate, 173 tb[TCA_POLICE_PEAKRATE]); 174 if (P_tab == NULL) 175 goto failure; 176 } 177 } 178 179 spin_lock_bh(&police->tcf_lock); 180 if (est) { 181 err = gen_replace_estimator(&police->tcf_bstats, NULL, 182 &police->tcf_rate_est, 183 &police->tcf_lock, est); 184 if (err) 185 goto failure_unlock; 186 } else if (tb[TCA_POLICE_AVRATE] && 187 (ret == ACT_P_CREATED || 188 !gen_estimator_active(&police->tcf_bstats, 189 &police->tcf_rate_est))) { 190 err = -EINVAL; 191 goto failure_unlock; 192 } 193 194 /* No failure allowed after this point */ 195 police->tcfp_mtu = parm->mtu; 196 if (police->tcfp_mtu == 0) { 197 police->tcfp_mtu = ~0; 198 if (R_tab) 199 police->tcfp_mtu = 255 << R_tab->rate.cell_log; 200 } 201 if (R_tab) { 202 police->rate_present = true; 203 psched_ratecfg_precompute(&police->rate, &R_tab->rate, 0); 204 qdisc_put_rtab(R_tab); 205 } else { 206 police->rate_present = false; 207 } 208 if (P_tab) { 209 police->peak_present = true; 210 psched_ratecfg_precompute(&police->peak, &P_tab->rate, 0); 211 qdisc_put_rtab(P_tab); 212 } else { 213 police->peak_present = false; 214 } 215 216 if (tb[TCA_POLICE_RESULT]) 217 police->tcfp_result = nla_get_u32(tb[TCA_POLICE_RESULT]); 218 police->tcfp_burst = PSCHED_TICKS2NS(parm->burst); 219 police->tcfp_toks = police->tcfp_burst; 220 if (police->peak_present) { 221 police->tcfp_mtu_ptoks = (s64) psched_l2t_ns(&police->peak, 222 police->tcfp_mtu); 223 police->tcfp_ptoks = police->tcfp_mtu_ptoks; 224 } 225 police->tcf_action = parm->action; 226 227 if (tb[TCA_POLICE_AVRATE]) 228 police->tcfp_ewma_rate = nla_get_u32(tb[TCA_POLICE_AVRATE]); 229 230 spin_unlock_bh(&police->tcf_lock); 231 if (ret != ACT_P_CREATED) 232 return ret; 233 234 police->tcfp_t_c = ktime_get_ns(); 235 police->tcf_index = parm->index ? parm->index : 236 tcf_hash_new_index(hinfo); 237 h = tcf_hash(police->tcf_index, POL_TAB_MASK); 238 spin_lock_bh(&hinfo->lock); 239 hlist_add_head(&police->tcf_head, &hinfo->htab[h]); 240 spin_unlock_bh(&hinfo->lock); 241 242 a->priv = police; 243 return ret; 244 245 failure_unlock: 246 spin_unlock_bh(&police->tcf_lock); 247 failure: 248 qdisc_put_rtab(P_tab); 249 qdisc_put_rtab(R_tab); 250 if (ret == ACT_P_CREATED) 251 kfree(police); 252 return err; 253 } 254 255 static int tcf_act_police(struct sk_buff *skb, const struct tc_action *a, 256 struct tcf_result *res) 257 { 258 struct tcf_police *police = a->priv; 259 s64 now; 260 s64 toks; 261 s64 ptoks = 0; 262 263 spin_lock(&police->tcf_lock); 264 265 bstats_update(&police->tcf_bstats, skb); 266 267 if (police->tcfp_ewma_rate && 268 police->tcf_rate_est.bps >= police->tcfp_ewma_rate) { 269 police->tcf_qstats.overlimits++; 270 if (police->tcf_action == TC_ACT_SHOT) 271 police->tcf_qstats.drops++; 272 spin_unlock(&police->tcf_lock); 273 return police->tcf_action; 274 } 275 276 if (qdisc_pkt_len(skb) <= police->tcfp_mtu) { 277 if (!police->rate_present) { 278 spin_unlock(&police->tcf_lock); 279 return police->tcfp_result; 280 } 281 282 now = ktime_get_ns(); 283 toks = min_t(s64, now - police->tcfp_t_c, 284 police->tcfp_burst); 285 if (police->peak_present) { 286 ptoks = toks + police->tcfp_ptoks; 287 if (ptoks > police->tcfp_mtu_ptoks) 288 ptoks = police->tcfp_mtu_ptoks; 289 ptoks -= (s64) psched_l2t_ns(&police->peak, 290 qdisc_pkt_len(skb)); 291 } 292 toks += police->tcfp_toks; 293 if (toks > police->tcfp_burst) 294 toks = police->tcfp_burst; 295 toks -= (s64) psched_l2t_ns(&police->rate, qdisc_pkt_len(skb)); 296 if ((toks|ptoks) >= 0) { 297 police->tcfp_t_c = now; 298 police->tcfp_toks = toks; 299 police->tcfp_ptoks = ptoks; 300 spin_unlock(&police->tcf_lock); 301 return police->tcfp_result; 302 } 303 } 304 305 police->tcf_qstats.overlimits++; 306 if (police->tcf_action == TC_ACT_SHOT) 307 police->tcf_qstats.drops++; 308 spin_unlock(&police->tcf_lock); 309 return police->tcf_action; 310 } 311 312 static int 313 tcf_act_police_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref) 314 { 315 unsigned char *b = skb_tail_pointer(skb); 316 struct tcf_police *police = a->priv; 317 struct tc_police opt = { 318 .index = police->tcf_index, 319 .action = police->tcf_action, 320 .mtu = police->tcfp_mtu, 321 .burst = PSCHED_NS2TICKS(police->tcfp_burst), 322 .refcnt = police->tcf_refcnt - ref, 323 .bindcnt = police->tcf_bindcnt - bind, 324 }; 325 326 if (police->rate_present) 327 psched_ratecfg_getrate(&opt.rate, &police->rate); 328 if (police->peak_present) 329 psched_ratecfg_getrate(&opt.peakrate, &police->peak); 330 if (nla_put(skb, TCA_POLICE_TBF, sizeof(opt), &opt)) 331 goto nla_put_failure; 332 if (police->tcfp_result && 333 nla_put_u32(skb, TCA_POLICE_RESULT, police->tcfp_result)) 334 goto nla_put_failure; 335 if (police->tcfp_ewma_rate && 336 nla_put_u32(skb, TCA_POLICE_AVRATE, police->tcfp_ewma_rate)) 337 goto nla_put_failure; 338 return skb->len; 339 340 nla_put_failure: 341 nlmsg_trim(skb, b); 342 return -1; 343 } 344 345 MODULE_AUTHOR("Alexey Kuznetsov"); 346 MODULE_DESCRIPTION("Policing actions"); 347 MODULE_LICENSE("GPL"); 348 349 static struct tc_action_ops act_police_ops = { 350 .kind = "police", 351 .type = TCA_ID_POLICE, 352 .owner = THIS_MODULE, 353 .act = tcf_act_police, 354 .dump = tcf_act_police_dump, 355 .init = tcf_act_police_locate, 356 .walk = tcf_act_police_walker 357 }; 358 359 static int __init 360 police_init_module(void) 361 { 362 return tcf_register_action(&act_police_ops, POL_TAB_MASK); 363 } 364 365 static void __exit 366 police_cleanup_module(void) 367 { 368 tcf_unregister_action(&act_police_ops); 369 } 370 371 module_init(police_init_module); 372 module_exit(police_cleanup_module); 373