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, bool rtnl_held, 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 if (!ovr) { 115 tcf_idr_release(*a, bind); 116 return -EEXIST; 117 } 118 119 police = to_police(*a); 120 if (parm->rate.rate) { 121 err = -ENOMEM; 122 R_tab = qdisc_get_rtab(&parm->rate, tb[TCA_POLICE_RATE], NULL); 123 if (R_tab == NULL) 124 goto failure; 125 126 if (parm->peakrate.rate) { 127 P_tab = qdisc_get_rtab(&parm->peakrate, 128 tb[TCA_POLICE_PEAKRATE], NULL); 129 if (P_tab == NULL) 130 goto failure; 131 } 132 } 133 134 if (est) { 135 err = gen_replace_estimator(&police->tcf_bstats, NULL, 136 &police->tcf_rate_est, 137 &police->tcf_lock, 138 NULL, est); 139 if (err) 140 goto failure; 141 } else if (tb[TCA_POLICE_AVRATE] && 142 (ret == ACT_P_CREATED || 143 !gen_estimator_active(&police->tcf_rate_est))) { 144 err = -EINVAL; 145 goto failure; 146 } 147 148 spin_lock_bh(&police->tcf_lock); 149 /* No failure allowed after this point */ 150 police->tcfp_mtu = parm->mtu; 151 if (police->tcfp_mtu == 0) { 152 police->tcfp_mtu = ~0; 153 if (R_tab) 154 police->tcfp_mtu = 255 << R_tab->rate.cell_log; 155 } 156 if (R_tab) { 157 police->rate_present = true; 158 psched_ratecfg_precompute(&police->rate, &R_tab->rate, 0); 159 qdisc_put_rtab(R_tab); 160 } else { 161 police->rate_present = false; 162 } 163 if (P_tab) { 164 police->peak_present = true; 165 psched_ratecfg_precompute(&police->peak, &P_tab->rate, 0); 166 qdisc_put_rtab(P_tab); 167 } else { 168 police->peak_present = false; 169 } 170 171 if (tb[TCA_POLICE_RESULT]) 172 police->tcfp_result = nla_get_u32(tb[TCA_POLICE_RESULT]); 173 police->tcfp_burst = PSCHED_TICKS2NS(parm->burst); 174 police->tcfp_toks = police->tcfp_burst; 175 if (police->peak_present) { 176 police->tcfp_mtu_ptoks = (s64) psched_l2t_ns(&police->peak, 177 police->tcfp_mtu); 178 police->tcfp_ptoks = police->tcfp_mtu_ptoks; 179 } 180 police->tcf_action = parm->action; 181 182 if (tb[TCA_POLICE_AVRATE]) 183 police->tcfp_ewma_rate = nla_get_u32(tb[TCA_POLICE_AVRATE]); 184 185 spin_unlock_bh(&police->tcf_lock); 186 if (ret != ACT_P_CREATED) 187 return ret; 188 189 police->tcfp_t_c = ktime_get_ns(); 190 tcf_idr_insert(tn, *a); 191 192 return ret; 193 194 failure: 195 qdisc_put_rtab(P_tab); 196 qdisc_put_rtab(R_tab); 197 tcf_idr_release(*a, bind); 198 return err; 199 } 200 201 static int tcf_act_police(struct sk_buff *skb, const struct tc_action *a, 202 struct tcf_result *res) 203 { 204 struct tcf_police *police = to_police(a); 205 s64 now; 206 s64 toks; 207 s64 ptoks = 0; 208 209 spin_lock(&police->tcf_lock); 210 211 bstats_update(&police->tcf_bstats, skb); 212 tcf_lastuse_update(&police->tcf_tm); 213 214 if (police->tcfp_ewma_rate) { 215 struct gnet_stats_rate_est64 sample; 216 217 if (!gen_estimator_read(&police->tcf_rate_est, &sample) || 218 sample.bps >= police->tcfp_ewma_rate) { 219 police->tcf_qstats.overlimits++; 220 if (police->tcf_action == TC_ACT_SHOT) 221 police->tcf_qstats.drops++; 222 spin_unlock(&police->tcf_lock); 223 return police->tcf_action; 224 } 225 } 226 227 if (qdisc_pkt_len(skb) <= police->tcfp_mtu) { 228 if (!police->rate_present) { 229 spin_unlock(&police->tcf_lock); 230 return police->tcfp_result; 231 } 232 233 now = ktime_get_ns(); 234 toks = min_t(s64, now - police->tcfp_t_c, 235 police->tcfp_burst); 236 if (police->peak_present) { 237 ptoks = toks + police->tcfp_ptoks; 238 if (ptoks > police->tcfp_mtu_ptoks) 239 ptoks = police->tcfp_mtu_ptoks; 240 ptoks -= (s64) psched_l2t_ns(&police->peak, 241 qdisc_pkt_len(skb)); 242 } 243 toks += police->tcfp_toks; 244 if (toks > police->tcfp_burst) 245 toks = police->tcfp_burst; 246 toks -= (s64) psched_l2t_ns(&police->rate, qdisc_pkt_len(skb)); 247 if ((toks|ptoks) >= 0) { 248 police->tcfp_t_c = now; 249 police->tcfp_toks = toks; 250 police->tcfp_ptoks = ptoks; 251 if (police->tcfp_result == TC_ACT_SHOT) 252 police->tcf_qstats.drops++; 253 spin_unlock(&police->tcf_lock); 254 return police->tcfp_result; 255 } 256 } 257 258 police->tcf_qstats.overlimits++; 259 if (police->tcf_action == TC_ACT_SHOT) 260 police->tcf_qstats.drops++; 261 spin_unlock(&police->tcf_lock); 262 return police->tcf_action; 263 } 264 265 static int tcf_act_police_dump(struct sk_buff *skb, struct tc_action *a, 266 int bind, int ref) 267 { 268 unsigned char *b = skb_tail_pointer(skb); 269 struct tcf_police *police = to_police(a); 270 struct tc_police opt = { 271 .index = police->tcf_index, 272 .action = police->tcf_action, 273 .mtu = police->tcfp_mtu, 274 .burst = PSCHED_NS2TICKS(police->tcfp_burst), 275 .refcnt = refcount_read(&police->tcf_refcnt) - ref, 276 .bindcnt = atomic_read(&police->tcf_bindcnt) - bind, 277 }; 278 struct tcf_t t; 279 280 if (police->rate_present) 281 psched_ratecfg_getrate(&opt.rate, &police->rate); 282 if (police->peak_present) 283 psched_ratecfg_getrate(&opt.peakrate, &police->peak); 284 if (nla_put(skb, TCA_POLICE_TBF, sizeof(opt), &opt)) 285 goto nla_put_failure; 286 if (police->tcfp_result && 287 nla_put_u32(skb, TCA_POLICE_RESULT, police->tcfp_result)) 288 goto nla_put_failure; 289 if (police->tcfp_ewma_rate && 290 nla_put_u32(skb, TCA_POLICE_AVRATE, police->tcfp_ewma_rate)) 291 goto nla_put_failure; 292 293 t.install = jiffies_to_clock_t(jiffies - police->tcf_tm.install); 294 t.lastuse = jiffies_to_clock_t(jiffies - police->tcf_tm.lastuse); 295 t.firstuse = jiffies_to_clock_t(jiffies - police->tcf_tm.firstuse); 296 t.expires = jiffies_to_clock_t(police->tcf_tm.expires); 297 if (nla_put_64bit(skb, TCA_POLICE_TM, sizeof(t), &t, TCA_POLICE_PAD)) 298 goto nla_put_failure; 299 300 return skb->len; 301 302 nla_put_failure: 303 nlmsg_trim(skb, b); 304 return -1; 305 } 306 307 static int tcf_police_search(struct net *net, struct tc_action **a, u32 index, 308 struct netlink_ext_ack *extack) 309 { 310 struct tc_action_net *tn = net_generic(net, police_net_id); 311 312 return tcf_idr_search(tn, a, index); 313 } 314 315 static int tcf_police_delete(struct net *net, u32 index) 316 { 317 struct tc_action_net *tn = net_generic(net, police_net_id); 318 319 return tcf_idr_delete_index(tn, index); 320 } 321 322 MODULE_AUTHOR("Alexey Kuznetsov"); 323 MODULE_DESCRIPTION("Policing actions"); 324 MODULE_LICENSE("GPL"); 325 326 static struct tc_action_ops act_police_ops = { 327 .kind = "police", 328 .type = TCA_ID_POLICE, 329 .owner = THIS_MODULE, 330 .act = tcf_act_police, 331 .dump = tcf_act_police_dump, 332 .init = tcf_act_police_init, 333 .walk = tcf_act_police_walker, 334 .lookup = tcf_police_search, 335 .delete = tcf_police_delete, 336 .size = sizeof(struct tcf_police), 337 }; 338 339 static __net_init int police_init_net(struct net *net) 340 { 341 struct tc_action_net *tn = net_generic(net, police_net_id); 342 343 return tc_action_net_init(tn, &act_police_ops); 344 } 345 346 static void __net_exit police_exit_net(struct list_head *net_list) 347 { 348 tc_action_net_exit(net_list, police_net_id); 349 } 350 351 static struct pernet_operations police_net_ops = { 352 .init = police_init_net, 353 .exit_batch = police_exit_net, 354 .id = &police_net_id, 355 .size = sizeof(struct tc_action_net), 356 }; 357 358 static int __init police_init_module(void) 359 { 360 return tcf_register_action(&act_police_ops, &police_net_ops); 361 } 362 363 static void __exit police_cleanup_module(void) 364 { 365 tcf_unregister_action(&act_police_ops, &police_net_ops); 366 } 367 368 module_init(police_init_module); 369 module_exit(police_cleanup_module); 370