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 67 return tcf_generic_walker(tn, skb, cb, type, ops); 68 } 69 70 static const struct nla_policy police_policy[TCA_POLICE_MAX + 1] = { 71 [TCA_POLICE_RATE] = { .len = TC_RTAB_SIZE }, 72 [TCA_POLICE_PEAKRATE] = { .len = TC_RTAB_SIZE }, 73 [TCA_POLICE_AVRATE] = { .type = NLA_U32 }, 74 [TCA_POLICE_RESULT] = { .type = NLA_U32 }, 75 }; 76 77 static int tcf_act_police_init(struct net *net, struct nlattr *nla, 78 struct nlattr *est, struct tc_action **a, 79 int ovr, int bind) 80 { 81 int ret = 0, err; 82 struct nlattr *tb[TCA_POLICE_MAX + 1]; 83 struct tc_police *parm; 84 struct tcf_police *police; 85 struct qdisc_rate_table *R_tab = NULL, *P_tab = NULL; 86 struct tc_action_net *tn = net_generic(net, police_net_id); 87 bool exists = false; 88 int size; 89 90 if (nla == NULL) 91 return -EINVAL; 92 93 err = nla_parse_nested(tb, TCA_POLICE_MAX, nla, police_policy); 94 if (err < 0) 95 return err; 96 97 if (tb[TCA_POLICE_TBF] == NULL) 98 return -EINVAL; 99 size = nla_len(tb[TCA_POLICE_TBF]); 100 if (size != sizeof(*parm) && size != sizeof(struct tc_police_compat)) 101 return -EINVAL; 102 103 parm = nla_data(tb[TCA_POLICE_TBF]); 104 exists = tcf_hash_check(tn, parm->index, a, bind); 105 if (exists && bind) 106 return 0; 107 108 if (!exists) { 109 ret = tcf_hash_create(tn, parm->index, NULL, a, 110 &act_police_ops, bind, false); 111 if (ret) 112 return ret; 113 ret = ACT_P_CREATED; 114 } else { 115 tcf_hash_release(*a, bind); 116 if (!ovr) 117 return -EEXIST; 118 } 119 120 police = to_police(*a); 121 if (parm->rate.rate) { 122 err = -ENOMEM; 123 R_tab = qdisc_get_rtab(&parm->rate, tb[TCA_POLICE_RATE]); 124 if (R_tab == NULL) 125 goto failure; 126 127 if (parm->peakrate.rate) { 128 P_tab = qdisc_get_rtab(&parm->peakrate, 129 tb[TCA_POLICE_PEAKRATE]); 130 if (P_tab == NULL) 131 goto failure; 132 } 133 } 134 135 spin_lock_bh(&police->tcf_lock); 136 if (est) { 137 err = gen_replace_estimator(&police->tcf_bstats, NULL, 138 &police->tcf_rate_est, 139 &police->tcf_lock, 140 NULL, est); 141 if (err) 142 goto failure_unlock; 143 } else if (tb[TCA_POLICE_AVRATE] && 144 (ret == ACT_P_CREATED || 145 !gen_estimator_active(&police->tcf_bstats, 146 &police->tcf_rate_est))) { 147 err = -EINVAL; 148 goto failure_unlock; 149 } 150 151 /* No failure allowed after this point */ 152 police->tcfp_mtu = parm->mtu; 153 if (police->tcfp_mtu == 0) { 154 police->tcfp_mtu = ~0; 155 if (R_tab) 156 police->tcfp_mtu = 255 << R_tab->rate.cell_log; 157 } 158 if (R_tab) { 159 police->rate_present = true; 160 psched_ratecfg_precompute(&police->rate, &R_tab->rate, 0); 161 qdisc_put_rtab(R_tab); 162 } else { 163 police->rate_present = false; 164 } 165 if (P_tab) { 166 police->peak_present = true; 167 psched_ratecfg_precompute(&police->peak, &P_tab->rate, 0); 168 qdisc_put_rtab(P_tab); 169 } else { 170 police->peak_present = false; 171 } 172 173 if (tb[TCA_POLICE_RESULT]) 174 police->tcfp_result = nla_get_u32(tb[TCA_POLICE_RESULT]); 175 police->tcfp_burst = PSCHED_TICKS2NS(parm->burst); 176 police->tcfp_toks = police->tcfp_burst; 177 if (police->peak_present) { 178 police->tcfp_mtu_ptoks = (s64) psched_l2t_ns(&police->peak, 179 police->tcfp_mtu); 180 police->tcfp_ptoks = police->tcfp_mtu_ptoks; 181 } 182 police->tcf_action = parm->action; 183 184 if (tb[TCA_POLICE_AVRATE]) 185 police->tcfp_ewma_rate = nla_get_u32(tb[TCA_POLICE_AVRATE]); 186 187 spin_unlock_bh(&police->tcf_lock); 188 if (ret != ACT_P_CREATED) 189 return ret; 190 191 police->tcfp_t_c = ktime_get_ns(); 192 tcf_hash_insert(tn, *a); 193 194 return ret; 195 196 failure_unlock: 197 spin_unlock_bh(&police->tcf_lock); 198 failure: 199 qdisc_put_rtab(P_tab); 200 qdisc_put_rtab(R_tab); 201 if (ret == ACT_P_CREATED) 202 tcf_hash_cleanup(*a, est); 203 return err; 204 } 205 206 static int tcf_act_police(struct sk_buff *skb, const struct tc_action *a, 207 struct tcf_result *res) 208 { 209 struct tcf_police *police = to_police(a); 210 s64 now; 211 s64 toks; 212 s64 ptoks = 0; 213 214 spin_lock(&police->tcf_lock); 215 216 bstats_update(&police->tcf_bstats, skb); 217 tcf_lastuse_update(&police->tcf_tm); 218 219 if (police->tcfp_ewma_rate && 220 police->tcf_rate_est.bps >= police->tcfp_ewma_rate) { 221 police->tcf_qstats.overlimits++; 222 if (police->tcf_action == TC_ACT_SHOT) 223 police->tcf_qstats.drops++; 224 spin_unlock(&police->tcf_lock); 225 return police->tcf_action; 226 } 227 228 if (qdisc_pkt_len(skb) <= police->tcfp_mtu) { 229 if (!police->rate_present) { 230 spin_unlock(&police->tcf_lock); 231 return police->tcfp_result; 232 } 233 234 now = ktime_get_ns(); 235 toks = min_t(s64, now - police->tcfp_t_c, 236 police->tcfp_burst); 237 if (police->peak_present) { 238 ptoks = toks + police->tcfp_ptoks; 239 if (ptoks > police->tcfp_mtu_ptoks) 240 ptoks = police->tcfp_mtu_ptoks; 241 ptoks -= (s64) psched_l2t_ns(&police->peak, 242 qdisc_pkt_len(skb)); 243 } 244 toks += police->tcfp_toks; 245 if (toks > police->tcfp_burst) 246 toks = police->tcfp_burst; 247 toks -= (s64) psched_l2t_ns(&police->rate, qdisc_pkt_len(skb)); 248 if ((toks|ptoks) >= 0) { 249 police->tcfp_t_c = now; 250 police->tcfp_toks = toks; 251 police->tcfp_ptoks = ptoks; 252 if (police->tcfp_result == TC_ACT_SHOT) 253 police->tcf_qstats.drops++; 254 spin_unlock(&police->tcf_lock); 255 return police->tcfp_result; 256 } 257 } 258 259 police->tcf_qstats.overlimits++; 260 if (police->tcf_action == TC_ACT_SHOT) 261 police->tcf_qstats.drops++; 262 spin_unlock(&police->tcf_lock); 263 return police->tcf_action; 264 } 265 266 static int tcf_act_police_dump(struct sk_buff *skb, struct tc_action *a, 267 int bind, int ref) 268 { 269 unsigned char *b = skb_tail_pointer(skb); 270 struct tcf_police *police = to_police(a); 271 struct tc_police opt = { 272 .index = police->tcf_index, 273 .action = police->tcf_action, 274 .mtu = police->tcfp_mtu, 275 .burst = PSCHED_NS2TICKS(police->tcfp_burst), 276 .refcnt = police->tcf_refcnt - ref, 277 .bindcnt = police->tcf_bindcnt - bind, 278 }; 279 struct tcf_t t; 280 281 if (police->rate_present) 282 psched_ratecfg_getrate(&opt.rate, &police->rate); 283 if (police->peak_present) 284 psched_ratecfg_getrate(&opt.peakrate, &police->peak); 285 if (nla_put(skb, TCA_POLICE_TBF, sizeof(opt), &opt)) 286 goto nla_put_failure; 287 if (police->tcfp_result && 288 nla_put_u32(skb, TCA_POLICE_RESULT, police->tcfp_result)) 289 goto nla_put_failure; 290 if (police->tcfp_ewma_rate && 291 nla_put_u32(skb, TCA_POLICE_AVRATE, police->tcfp_ewma_rate)) 292 goto nla_put_failure; 293 294 t.install = jiffies_to_clock_t(jiffies - police->tcf_tm.install); 295 t.lastuse = jiffies_to_clock_t(jiffies - police->tcf_tm.lastuse); 296 t.firstuse = jiffies_to_clock_t(jiffies - police->tcf_tm.firstuse); 297 t.expires = jiffies_to_clock_t(police->tcf_tm.expires); 298 if (nla_put_64bit(skb, TCA_POLICE_TM, sizeof(t), &t, TCA_POLICE_PAD)) 299 goto nla_put_failure; 300 301 return skb->len; 302 303 nla_put_failure: 304 nlmsg_trim(skb, b); 305 return -1; 306 } 307 308 static int tcf_police_search(struct net *net, struct tc_action **a, u32 index) 309 { 310 struct tc_action_net *tn = net_generic(net, police_net_id); 311 312 return tcf_hash_search(tn, a, index); 313 } 314 315 MODULE_AUTHOR("Alexey Kuznetsov"); 316 MODULE_DESCRIPTION("Policing actions"); 317 MODULE_LICENSE("GPL"); 318 319 static struct tc_action_ops act_police_ops = { 320 .kind = "police", 321 .type = TCA_ID_POLICE, 322 .owner = THIS_MODULE, 323 .act = tcf_act_police, 324 .dump = tcf_act_police_dump, 325 .init = tcf_act_police_init, 326 .walk = tcf_act_police_walker, 327 .lookup = tcf_police_search, 328 .size = sizeof(struct tcf_police), 329 }; 330 331 static __net_init int police_init_net(struct net *net) 332 { 333 struct tc_action_net *tn = net_generic(net, police_net_id); 334 335 return tc_action_net_init(tn, &act_police_ops, POL_TAB_MASK); 336 } 337 338 static void __net_exit police_exit_net(struct net *net) 339 { 340 struct tc_action_net *tn = net_generic(net, police_net_id); 341 342 tc_action_net_exit(tn); 343 } 344 345 static struct pernet_operations police_net_ops = { 346 .init = police_init_net, 347 .exit = police_exit_net, 348 .id = &police_net_id, 349 .size = sizeof(struct tc_action_net), 350 }; 351 352 static int __init police_init_module(void) 353 { 354 return tcf_register_action(&act_police_ops, &police_net_ops); 355 } 356 357 static void __exit police_cleanup_module(void) 358 { 359 tcf_unregister_action(&act_police_ops, &police_net_ops); 360 } 361 362 module_init(police_init_module); 363 module_exit(police_cleanup_module); 364