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 /* old policer structure from before tc actions */ 44 struct tc_police_compat { 45 u32 index; 46 int action; 47 u32 limit; 48 u32 burst; 49 u32 mtu; 50 struct tc_ratespec rate; 51 struct tc_ratespec peakrate; 52 }; 53 54 /* Each policer is serialized by its individual spinlock */ 55 56 static unsigned int police_net_id; 57 static struct tc_action_ops act_police_ops; 58 59 static int tcf_act_police_walker(struct net *net, struct sk_buff *skb, 60 struct netlink_callback *cb, int type, 61 const struct tc_action_ops *ops, 62 struct netlink_ext_ack *extack) 63 { 64 struct tc_action_net *tn = net_generic(net, police_net_id); 65 66 return tcf_generic_walker(tn, skb, cb, type, ops, extack); 67 } 68 69 static const struct nla_policy police_policy[TCA_POLICE_MAX + 1] = { 70 [TCA_POLICE_RATE] = { .len = TC_RTAB_SIZE }, 71 [TCA_POLICE_PEAKRATE] = { .len = TC_RTAB_SIZE }, 72 [TCA_POLICE_AVRATE] = { .type = NLA_U32 }, 73 [TCA_POLICE_RESULT] = { .type = NLA_U32 }, 74 }; 75 76 static int tcf_act_police_init(struct net *net, struct nlattr *nla, 77 struct nlattr *est, struct tc_action **a, 78 int ovr, int bind, 79 struct netlink_ext_ack *extack) 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, NULL); 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_idr_check(tn, parm->index, a, bind); 105 if (exists && bind) 106 return 0; 107 108 if (!exists) { 109 ret = tcf_idr_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_idr_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], NULL); 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], NULL); 130 if (P_tab == NULL) 131 goto failure; 132 } 133 } 134 135 if (est) { 136 err = gen_replace_estimator(&police->tcf_bstats, NULL, 137 &police->tcf_rate_est, 138 &police->tcf_lock, 139 NULL, est); 140 if (err) 141 goto failure; 142 } else if (tb[TCA_POLICE_AVRATE] && 143 (ret == ACT_P_CREATED || 144 !gen_estimator_active(&police->tcf_rate_est))) { 145 err = -EINVAL; 146 goto failure; 147 } 148 149 spin_lock_bh(&police->tcf_lock); 150 /* No failure allowed after this point */ 151 police->tcfp_mtu = parm->mtu; 152 if (police->tcfp_mtu == 0) { 153 police->tcfp_mtu = ~0; 154 if (R_tab) 155 police->tcfp_mtu = 255 << R_tab->rate.cell_log; 156 } 157 if (R_tab) { 158 police->rate_present = true; 159 psched_ratecfg_precompute(&police->rate, &R_tab->rate, 0); 160 qdisc_put_rtab(R_tab); 161 } else { 162 police->rate_present = false; 163 } 164 if (P_tab) { 165 police->peak_present = true; 166 psched_ratecfg_precompute(&police->peak, &P_tab->rate, 0); 167 qdisc_put_rtab(P_tab); 168 } else { 169 police->peak_present = false; 170 } 171 172 if (tb[TCA_POLICE_RESULT]) 173 police->tcfp_result = nla_get_u32(tb[TCA_POLICE_RESULT]); 174 police->tcfp_burst = PSCHED_TICKS2NS(parm->burst); 175 police->tcfp_toks = police->tcfp_burst; 176 if (police->peak_present) { 177 police->tcfp_mtu_ptoks = (s64) psched_l2t_ns(&police->peak, 178 police->tcfp_mtu); 179 police->tcfp_ptoks = police->tcfp_mtu_ptoks; 180 } 181 police->tcf_action = parm->action; 182 183 if (tb[TCA_POLICE_AVRATE]) 184 police->tcfp_ewma_rate = nla_get_u32(tb[TCA_POLICE_AVRATE]); 185 186 spin_unlock_bh(&police->tcf_lock); 187 if (ret != ACT_P_CREATED) 188 return ret; 189 190 police->tcfp_t_c = ktime_get_ns(); 191 tcf_idr_insert(tn, *a); 192 193 return ret; 194 195 failure: 196 qdisc_put_rtab(P_tab); 197 qdisc_put_rtab(R_tab); 198 if (ret == ACT_P_CREATED) 199 tcf_idr_release(*a, bind); 200 return err; 201 } 202 203 static int tcf_act_police(struct sk_buff *skb, const struct tc_action *a, 204 struct tcf_result *res) 205 { 206 struct tcf_police *police = to_police(a); 207 s64 now; 208 s64 toks; 209 s64 ptoks = 0; 210 211 spin_lock(&police->tcf_lock); 212 213 bstats_update(&police->tcf_bstats, skb); 214 tcf_lastuse_update(&police->tcf_tm); 215 216 if (police->tcfp_ewma_rate) { 217 struct gnet_stats_rate_est64 sample; 218 219 if (!gen_estimator_read(&police->tcf_rate_est, &sample) || 220 sample.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 } 228 229 if (qdisc_pkt_len(skb) <= police->tcfp_mtu) { 230 if (!police->rate_present) { 231 spin_unlock(&police->tcf_lock); 232 return police->tcfp_result; 233 } 234 235 now = ktime_get_ns(); 236 toks = min_t(s64, now - police->tcfp_t_c, 237 police->tcfp_burst); 238 if (police->peak_present) { 239 ptoks = toks + police->tcfp_ptoks; 240 if (ptoks > police->tcfp_mtu_ptoks) 241 ptoks = police->tcfp_mtu_ptoks; 242 ptoks -= (s64) psched_l2t_ns(&police->peak, 243 qdisc_pkt_len(skb)); 244 } 245 toks += police->tcfp_toks; 246 if (toks > police->tcfp_burst) 247 toks = police->tcfp_burst; 248 toks -= (s64) psched_l2t_ns(&police->rate, qdisc_pkt_len(skb)); 249 if ((toks|ptoks) >= 0) { 250 police->tcfp_t_c = now; 251 police->tcfp_toks = toks; 252 police->tcfp_ptoks = ptoks; 253 if (police->tcfp_result == TC_ACT_SHOT) 254 police->tcf_qstats.drops++; 255 spin_unlock(&police->tcf_lock); 256 return police->tcfp_result; 257 } 258 } 259 260 police->tcf_qstats.overlimits++; 261 if (police->tcf_action == TC_ACT_SHOT) 262 police->tcf_qstats.drops++; 263 spin_unlock(&police->tcf_lock); 264 return police->tcf_action; 265 } 266 267 static int tcf_act_police_dump(struct sk_buff *skb, struct tc_action *a, 268 int bind, int ref) 269 { 270 unsigned char *b = skb_tail_pointer(skb); 271 struct tcf_police *police = to_police(a); 272 struct tc_police opt = { 273 .index = police->tcf_index, 274 .action = police->tcf_action, 275 .mtu = police->tcfp_mtu, 276 .burst = PSCHED_NS2TICKS(police->tcfp_burst), 277 .refcnt = police->tcf_refcnt - ref, 278 .bindcnt = police->tcf_bindcnt - bind, 279 }; 280 struct tcf_t t; 281 282 if (police->rate_present) 283 psched_ratecfg_getrate(&opt.rate, &police->rate); 284 if (police->peak_present) 285 psched_ratecfg_getrate(&opt.peakrate, &police->peak); 286 if (nla_put(skb, TCA_POLICE_TBF, sizeof(opt), &opt)) 287 goto nla_put_failure; 288 if (police->tcfp_result && 289 nla_put_u32(skb, TCA_POLICE_RESULT, police->tcfp_result)) 290 goto nla_put_failure; 291 if (police->tcfp_ewma_rate && 292 nla_put_u32(skb, TCA_POLICE_AVRATE, police->tcfp_ewma_rate)) 293 goto nla_put_failure; 294 295 t.install = jiffies_to_clock_t(jiffies - police->tcf_tm.install); 296 t.lastuse = jiffies_to_clock_t(jiffies - police->tcf_tm.lastuse); 297 t.firstuse = jiffies_to_clock_t(jiffies - police->tcf_tm.firstuse); 298 t.expires = jiffies_to_clock_t(police->tcf_tm.expires); 299 if (nla_put_64bit(skb, TCA_POLICE_TM, sizeof(t), &t, TCA_POLICE_PAD)) 300 goto nla_put_failure; 301 302 return skb->len; 303 304 nla_put_failure: 305 nlmsg_trim(skb, b); 306 return -1; 307 } 308 309 static int tcf_police_search(struct net *net, struct tc_action **a, u32 index, 310 struct netlink_ext_ack *extack) 311 { 312 struct tc_action_net *tn = net_generic(net, police_net_id); 313 314 return tcf_idr_search(tn, a, index); 315 } 316 317 MODULE_AUTHOR("Alexey Kuznetsov"); 318 MODULE_DESCRIPTION("Policing actions"); 319 MODULE_LICENSE("GPL"); 320 321 static struct tc_action_ops act_police_ops = { 322 .kind = "police", 323 .type = TCA_ID_POLICE, 324 .owner = THIS_MODULE, 325 .act = tcf_act_police, 326 .dump = tcf_act_police_dump, 327 .init = tcf_act_police_init, 328 .walk = tcf_act_police_walker, 329 .lookup = tcf_police_search, 330 .size = sizeof(struct tcf_police), 331 }; 332 333 static __net_init int police_init_net(struct net *net) 334 { 335 struct tc_action_net *tn = net_generic(net, police_net_id); 336 337 return tc_action_net_init(tn, &act_police_ops); 338 } 339 340 static void __net_exit police_exit_net(struct list_head *net_list) 341 { 342 tc_action_net_exit(net_list, police_net_id); 343 } 344 345 static struct pernet_operations police_net_ops = { 346 .init = police_init_net, 347 .exit_batch = 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