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 #define L2T(p,L) qdisc_l2t((p)->tcfp_R_tab, L) 26 #define L2T_P(p,L) qdisc_l2t((p)->tcfp_P_tab, L) 27 28 #define POL_TAB_MASK 15 29 static struct tcf_common *tcf_police_ht[POL_TAB_MASK + 1]; 30 static u32 police_idx_gen; 31 static DEFINE_RWLOCK(police_lock); 32 33 static struct tcf_hashinfo police_hash_info = { 34 .htab = tcf_police_ht, 35 .hmask = POL_TAB_MASK, 36 .lock = &police_lock, 37 }; 38 39 /* old policer structure from before tc actions */ 40 struct tc_police_compat 41 { 42 u32 index; 43 int action; 44 u32 limit; 45 u32 burst; 46 u32 mtu; 47 struct tc_ratespec rate; 48 struct tc_ratespec peakrate; 49 }; 50 51 /* Each policer is serialized by its individual spinlock */ 52 53 static int tcf_act_police_walker(struct sk_buff *skb, struct netlink_callback *cb, 54 int type, struct tc_action *a) 55 { 56 struct tcf_common *p; 57 int err = 0, index = -1, i = 0, s_i = 0, n_i = 0; 58 struct nlattr *nest; 59 60 read_lock_bh(&police_lock); 61 62 s_i = cb->args[0]; 63 64 for (i = 0; i < (POL_TAB_MASK + 1); i++) { 65 p = tcf_police_ht[tcf_hash(i, POL_TAB_MASK)]; 66 67 for (; p; p = p->tcfc_next) { 68 index++; 69 if (index < s_i) 70 continue; 71 a->priv = p; 72 a->order = index; 73 nest = nla_nest_start(skb, a->order); 74 if (nest == NULL) 75 goto nla_put_failure; 76 if (type == RTM_DELACTION) 77 err = tcf_action_dump_1(skb, a, 0, 1); 78 else 79 err = tcf_action_dump_1(skb, a, 0, 0); 80 if (err < 0) { 81 index--; 82 nla_nest_cancel(skb, nest); 83 goto done; 84 } 85 nla_nest_end(skb, nest); 86 n_i++; 87 } 88 } 89 done: 90 read_unlock_bh(&police_lock); 91 if (n_i) 92 cb->args[0] += n_i; 93 return n_i; 94 95 nla_put_failure: 96 nla_nest_cancel(skb, nest); 97 goto done; 98 } 99 100 static void tcf_police_destroy(struct tcf_police *p) 101 { 102 unsigned int h = tcf_hash(p->tcf_index, POL_TAB_MASK); 103 struct tcf_common **p1p; 104 105 for (p1p = &tcf_police_ht[h]; *p1p; p1p = &(*p1p)->tcfc_next) { 106 if (*p1p == &p->common) { 107 write_lock_bh(&police_lock); 108 *p1p = p->tcf_next; 109 write_unlock_bh(&police_lock); 110 gen_kill_estimator(&p->tcf_bstats, 111 &p->tcf_rate_est); 112 if (p->tcfp_R_tab) 113 qdisc_put_rtab(p->tcfp_R_tab); 114 if (p->tcfp_P_tab) 115 qdisc_put_rtab(p->tcfp_P_tab); 116 kfree(p); 117 return; 118 } 119 } 120 WARN_ON(1); 121 } 122 123 static const struct nla_policy police_policy[TCA_POLICE_MAX + 1] = { 124 [TCA_POLICE_RATE] = { .len = TC_RTAB_SIZE }, 125 [TCA_POLICE_PEAKRATE] = { .len = TC_RTAB_SIZE }, 126 [TCA_POLICE_AVRATE] = { .type = NLA_U32 }, 127 [TCA_POLICE_RESULT] = { .type = NLA_U32 }, 128 }; 129 130 static int tcf_act_police_locate(struct nlattr *nla, struct nlattr *est, 131 struct tc_action *a, int ovr, int bind) 132 { 133 unsigned h; 134 int ret = 0, err; 135 struct nlattr *tb[TCA_POLICE_MAX + 1]; 136 struct tc_police *parm; 137 struct tcf_police *police; 138 struct qdisc_rate_table *R_tab = NULL, *P_tab = NULL; 139 int size; 140 141 if (nla == NULL) 142 return -EINVAL; 143 144 err = nla_parse_nested(tb, TCA_POLICE_MAX, nla, police_policy); 145 if (err < 0) 146 return err; 147 148 if (tb[TCA_POLICE_TBF] == NULL) 149 return -EINVAL; 150 size = nla_len(tb[TCA_POLICE_TBF]); 151 if (size != sizeof(*parm) && size != sizeof(struct tc_police_compat)) 152 return -EINVAL; 153 parm = nla_data(tb[TCA_POLICE_TBF]); 154 155 if (parm->index) { 156 struct tcf_common *pc; 157 158 pc = tcf_hash_lookup(parm->index, &police_hash_info); 159 if (pc != NULL) { 160 a->priv = pc; 161 police = to_police(pc); 162 if (bind) { 163 police->tcf_bindcnt += 1; 164 police->tcf_refcnt += 1; 165 } 166 if (ovr) 167 goto override; 168 return ret; 169 } 170 } 171 172 police = kzalloc(sizeof(*police), GFP_KERNEL); 173 if (police == NULL) 174 return -ENOMEM; 175 ret = ACT_P_CREATED; 176 police->tcf_refcnt = 1; 177 spin_lock_init(&police->tcf_lock); 178 if (bind) 179 police->tcf_bindcnt = 1; 180 override: 181 if (parm->rate.rate) { 182 err = -ENOMEM; 183 R_tab = qdisc_get_rtab(&parm->rate, tb[TCA_POLICE_RATE]); 184 if (R_tab == NULL) 185 goto failure; 186 187 if (parm->peakrate.rate) { 188 P_tab = qdisc_get_rtab(&parm->peakrate, 189 tb[TCA_POLICE_PEAKRATE]); 190 if (P_tab == NULL) 191 goto failure; 192 } 193 } 194 195 spin_lock_bh(&police->tcf_lock); 196 if (est) { 197 err = gen_replace_estimator(&police->tcf_bstats, 198 &police->tcf_rate_est, 199 &police->tcf_lock, est); 200 if (err) 201 goto failure_unlock; 202 } else if (tb[TCA_POLICE_AVRATE] && 203 (ret == ACT_P_CREATED || 204 !gen_estimator_active(&police->tcf_bstats, 205 &police->tcf_rate_est))) { 206 err = -EINVAL; 207 goto failure_unlock; 208 } 209 210 /* No failure allowed after this point */ 211 if (R_tab != NULL) { 212 qdisc_put_rtab(police->tcfp_R_tab); 213 police->tcfp_R_tab = R_tab; 214 } 215 if (P_tab != NULL) { 216 qdisc_put_rtab(police->tcfp_P_tab); 217 police->tcfp_P_tab = P_tab; 218 } 219 220 if (tb[TCA_POLICE_RESULT]) 221 police->tcfp_result = nla_get_u32(tb[TCA_POLICE_RESULT]); 222 police->tcfp_toks = police->tcfp_burst = parm->burst; 223 police->tcfp_mtu = parm->mtu; 224 if (police->tcfp_mtu == 0) { 225 police->tcfp_mtu = ~0; 226 if (police->tcfp_R_tab) 227 police->tcfp_mtu = 255<<police->tcfp_R_tab->rate.cell_log; 228 } 229 if (police->tcfp_P_tab) 230 police->tcfp_ptoks = L2T_P(police, police->tcfp_mtu); 231 police->tcf_action = parm->action; 232 233 if (tb[TCA_POLICE_AVRATE]) 234 police->tcfp_ewma_rate = nla_get_u32(tb[TCA_POLICE_AVRATE]); 235 236 spin_unlock_bh(&police->tcf_lock); 237 if (ret != ACT_P_CREATED) 238 return ret; 239 240 police->tcfp_t_c = psched_get_time(); 241 police->tcf_index = parm->index ? parm->index : 242 tcf_hash_new_index(&police_idx_gen, &police_hash_info); 243 h = tcf_hash(police->tcf_index, POL_TAB_MASK); 244 write_lock_bh(&police_lock); 245 police->tcf_next = tcf_police_ht[h]; 246 tcf_police_ht[h] = &police->common; 247 write_unlock_bh(&police_lock); 248 249 a->priv = police; 250 return ret; 251 252 failure_unlock: 253 spin_unlock_bh(&police->tcf_lock); 254 failure: 255 if (P_tab) 256 qdisc_put_rtab(P_tab); 257 if (R_tab) 258 qdisc_put_rtab(R_tab); 259 if (ret == ACT_P_CREATED) 260 kfree(police); 261 return err; 262 } 263 264 static int tcf_act_police_cleanup(struct tc_action *a, int bind) 265 { 266 struct tcf_police *p = a->priv; 267 int ret = 0; 268 269 if (p != NULL) { 270 if (bind) 271 p->tcf_bindcnt--; 272 273 p->tcf_refcnt--; 274 if (p->tcf_refcnt <= 0 && !p->tcf_bindcnt) { 275 tcf_police_destroy(p); 276 ret = 1; 277 } 278 } 279 return ret; 280 } 281 282 static int tcf_act_police(struct sk_buff *skb, struct tc_action *a, 283 struct tcf_result *res) 284 { 285 struct tcf_police *police = a->priv; 286 psched_time_t now; 287 long toks; 288 long ptoks = 0; 289 290 spin_lock(&police->tcf_lock); 291 292 police->tcf_bstats.bytes += qdisc_pkt_len(skb); 293 police->tcf_bstats.packets++; 294 295 if (police->tcfp_ewma_rate && 296 police->tcf_rate_est.bps >= police->tcfp_ewma_rate) { 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 if (qdisc_pkt_len(skb) <= police->tcfp_mtu) { 305 if (police->tcfp_R_tab == NULL) { 306 spin_unlock(&police->tcf_lock); 307 return police->tcfp_result; 308 } 309 310 now = psched_get_time(); 311 toks = psched_tdiff_bounded(now, police->tcfp_t_c, 312 police->tcfp_burst); 313 if (police->tcfp_P_tab) { 314 ptoks = toks + police->tcfp_ptoks; 315 if (ptoks > (long)L2T_P(police, police->tcfp_mtu)) 316 ptoks = (long)L2T_P(police, police->tcfp_mtu); 317 ptoks -= L2T_P(police, qdisc_pkt_len(skb)); 318 } 319 toks += police->tcfp_toks; 320 if (toks > (long)police->tcfp_burst) 321 toks = police->tcfp_burst; 322 toks -= L2T(police, qdisc_pkt_len(skb)); 323 if ((toks|ptoks) >= 0) { 324 police->tcfp_t_c = now; 325 police->tcfp_toks = toks; 326 police->tcfp_ptoks = ptoks; 327 spin_unlock(&police->tcf_lock); 328 return police->tcfp_result; 329 } 330 } 331 332 police->tcf_qstats.overlimits++; 333 if (police->tcf_action == TC_ACT_SHOT) 334 police->tcf_qstats.drops++; 335 spin_unlock(&police->tcf_lock); 336 return police->tcf_action; 337 } 338 339 static int 340 tcf_act_police_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref) 341 { 342 unsigned char *b = skb_tail_pointer(skb); 343 struct tcf_police *police = a->priv; 344 struct tc_police opt; 345 346 opt.index = police->tcf_index; 347 opt.action = police->tcf_action; 348 opt.mtu = police->tcfp_mtu; 349 opt.burst = police->tcfp_burst; 350 opt.refcnt = police->tcf_refcnt - ref; 351 opt.bindcnt = police->tcf_bindcnt - bind; 352 if (police->tcfp_R_tab) 353 opt.rate = police->tcfp_R_tab->rate; 354 else 355 memset(&opt.rate, 0, sizeof(opt.rate)); 356 if (police->tcfp_P_tab) 357 opt.peakrate = police->tcfp_P_tab->rate; 358 else 359 memset(&opt.peakrate, 0, sizeof(opt.peakrate)); 360 NLA_PUT(skb, TCA_POLICE_TBF, sizeof(opt), &opt); 361 if (police->tcfp_result) 362 NLA_PUT_U32(skb, TCA_POLICE_RESULT, police->tcfp_result); 363 if (police->tcfp_ewma_rate) 364 NLA_PUT_U32(skb, TCA_POLICE_AVRATE, police->tcfp_ewma_rate); 365 return skb->len; 366 367 nla_put_failure: 368 nlmsg_trim(skb, b); 369 return -1; 370 } 371 372 MODULE_AUTHOR("Alexey Kuznetsov"); 373 MODULE_DESCRIPTION("Policing actions"); 374 MODULE_LICENSE("GPL"); 375 376 static struct tc_action_ops act_police_ops = { 377 .kind = "police", 378 .hinfo = &police_hash_info, 379 .type = TCA_ID_POLICE, 380 .capab = TCA_CAP_NONE, 381 .owner = THIS_MODULE, 382 .act = tcf_act_police, 383 .dump = tcf_act_police_dump, 384 .cleanup = tcf_act_police_cleanup, 385 .lookup = tcf_hash_search, 386 .init = tcf_act_police_locate, 387 .walk = tcf_act_police_walker 388 }; 389 390 static int __init 391 police_init_module(void) 392 { 393 return tcf_register_action(&act_police_ops); 394 } 395 396 static void __exit 397 police_cleanup_module(void) 398 { 399 tcf_unregister_action(&act_police_ops); 400 } 401 402 module_init(police_init_module); 403 module_exit(police_cleanup_module); 404