net/sched/act_police.c

   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 <asm/uaccess.h>
  14 #include <asm/system.h>
  15 #include <linux/bitops.h>
  16 #include <linux/module.h>
  17 #include <linux/types.h>
  18 #include <linux/kernel.h>
  19 #include <linux/sched.h>
  20 #include <linux/string.h>
  21 #include <linux/mm.h>
  22 #include <linux/socket.h>
  23 #include <linux/sockios.h>
  24 #include <linux/in.h>
  25 #include <linux/errno.h>
  26 #include <linux/interrupt.h>
  27 #include <linux/netdevice.h>
  28 #include <linux/skbuff.h>
  29 #include <linux/module.h>
  30 #include <linux/rtnetlink.h>
  31 #include <linux/init.h>
  32 #include <net/sock.h>
  33 #include <net/act_api.h>
  34
  35 #define L2T(p,L)   ((p)->R_tab->data[(L)>>(p)->R_tab->rate.cell_log])
  36 #define L2T_P(p,L) ((p)->P_tab->data[(L)>>(p)->P_tab->rate.cell_log])
  37 #define PRIV(a) ((struct tcf_police *) (a)->priv)
  38
  39 /* use generic hash table */
  40 #define MY_TAB_SIZE     16
  41 #define MY_TAB_MASK     15
  42 static u32 idx_gen;
  43 static struct tcf_police *tcf_police_ht[MY_TAB_SIZE];
  44 /* Policer hash table lock */
  45 static DEFINE_RWLOCK(police_lock);
  46
  47 /* Each policer is serialized by its individual spinlock */
  48
  49 static __inline__ unsigned tcf_police_hash(u32 index)
  50 {
  51         return index&0xF;
  52 }
  53
  54 static __inline__ struct tcf_police * tcf_police_lookup(u32 index)
  55 {
  56         struct tcf_police *p;
  57
  58         read_lock(&police_lock);
  59         for (p = tcf_police_ht[tcf_police_hash(index)]; p; p = p->next) {
  60                 if (p->index == index)
  61                         break;
  62         }
  63         read_unlock(&police_lock);
  64         return p;
  65 }
  66
  67 #ifdef CONFIG_NET_CLS_ACT
  68 static int tcf_act_police_walker(struct sk_buff *skb, struct netlink_callback *cb,
  69                               int type, struct tc_action *a)
  70 {
  71         struct tcf_police *p;
  72         int err = 0, index = -1, i = 0, s_i = 0, n_i = 0;
  73         struct rtattr *r;
  74
  75         read_lock(&police_lock);
  76
  77         s_i = cb->args[0];
  78
  79         for (i = 0; i < MY_TAB_SIZE; i++) {
  80                 p = tcf_police_ht[tcf_police_hash(i)];
  81
  82                 for (; p; p = p->next) {
  83                         index++;
  84                         if (index < s_i)
  85                                 continue;
  86                         a->priv = p;
  87                         a->order = index;
  88                         r = (struct rtattr*) skb->tail;
  89                         RTA_PUT(skb, a->order, 0, NULL);
  90                         if (type == RTM_DELACTION)
  91                                 err = tcf_action_dump_1(skb, a, 0, 1);
  92                         else
  93                                 err = tcf_action_dump_1(skb, a, 0, 0);
  94                         if (err < 0) {
  95                                 index--;
  96                                 skb_trim(skb, (u8*)r - skb->data);
  97                                 goto done;
  98                         }
  99                         r->rta_len = skb->tail - (u8*)r;
 100                         n_i++;
 101                 }
 102         }
 103 done:
 104         read_unlock(&police_lock);
 105         if (n_i)
 106                 cb->args[0] += n_i;
 107         return n_i;
 108
 109 rtattr_failure:
 110         skb_trim(skb, (u8*)r - skb->data);
 111         goto done;
 112 }
 113
 114 static inline int
 115 tcf_act_police_hash_search(struct tc_action *a, u32 index)
 116 {
 117         struct tcf_police *p = tcf_police_lookup(index);
 118
 119         if (p != NULL) {
 120                 a->priv = p;
 121                 return 1;
 122         } else {
 123                 return 0;
 124         }
 125 }
 126 #endif
 127
 128 static inline u32 tcf_police_new_index(void)
 129 {
 130         do {
 131                 if (++idx_gen == 0)
 132                         idx_gen = 1;
 133         } while (tcf_police_lookup(idx_gen));
 134
 135         return idx_gen;
 136 }
 137
 138 void tcf_police_destroy(struct tcf_police *p)
 139 {
 140         unsigned h = tcf_police_hash(p->index);
 141         struct tcf_police **p1p;
 142
 143         for (p1p = &tcf_police_ht[h]; *p1p; p1p = &(*p1p)->next) {
 144                 if (*p1p == p) {
 145                         write_lock_bh(&police_lock);
 146                         *p1p = p->next;
 147                         write_unlock_bh(&police_lock);
 148 #ifdef CONFIG_NET_ESTIMATOR
 149                         gen_kill_estimator(&p->bstats, &p->rate_est);
 150 #endif
 151                         if (p->R_tab)
 152                                 qdisc_put_rtab(p->R_tab);
 153                         if (p->P_tab)
 154                                 qdisc_put_rtab(p->P_tab);
 155                         kfree(p);
 156                         return;
 157                 }
 158         }
 159         BUG_TRAP(0);
 160 }
 161
 162 #ifdef CONFIG_NET_CLS_ACT
 163 static int tcf_act_police_locate(struct rtattr *rta, struct rtattr *est,
 164                                  struct tc_action *a, int ovr, int bind)
 165 {
 166         unsigned h;
 167         int ret = 0, err;
 168         struct rtattr *tb[TCA_POLICE_MAX];
 169         struct tc_police *parm;
 170         struct tcf_police *p;
 171         struct qdisc_rate_table *R_tab = NULL, *P_tab = NULL;
 172
 173         if (rta == NULL || rtattr_parse_nested(tb, TCA_POLICE_MAX, rta) < 0)
 174                 return -EINVAL;
 175
 176         if (tb[TCA_POLICE_TBF-1] == NULL ||
 177             RTA_PAYLOAD(tb[TCA_POLICE_TBF-1]) != sizeof(*parm))
 178                 return -EINVAL;
 179         parm = RTA_DATA(tb[TCA_POLICE_TBF-1]);
 180
 181         if (tb[TCA_POLICE_RESULT-1] != NULL &&
 182             RTA_PAYLOAD(tb[TCA_POLICE_RESULT-1]) != sizeof(u32))
 183                 return -EINVAL;
 184         if (tb[TCA_POLICE_RESULT-1] != NULL &&
 185             RTA_PAYLOAD(tb[TCA_POLICE_RESULT-1]) != sizeof(u32))
 186                 return -EINVAL;
 187
 188         if (parm->index && (p = tcf_police_lookup(parm->index)) != NULL) {
 189                 a->priv = p;
 190                 if (bind) {
 191                         p->bindcnt += 1;
 192                         p->refcnt += 1;
 193                 }
 194                 if (ovr)
 195                         goto override;
 196                 return ret;
 197         }
 198
 199         p = kmalloc(sizeof(*p), GFP_KERNEL);
 200         if (p == NULL)
 201                 return -ENOMEM;
 202         memset(p, 0, sizeof(*p));
 203
 204         ret = ACT_P_CREATED;
 205         p->refcnt = 1;
 206         spin_lock_init(&p->lock);
 207         p->stats_lock = &p->lock;
 208         if (bind)
 209                 p->bindcnt = 1;
 210 override:
 211         if (parm->rate.rate) {
 212                 err = -ENOMEM;
 213                 R_tab = qdisc_get_rtab(&parm->rate, tb[TCA_POLICE_RATE-1]);
 214                 if (R_tab == NULL)
 215                         goto failure;
 216                 if (parm->peakrate.rate) {
 217                         P_tab = qdisc_get_rtab(&parm->peakrate,
 218                                                tb[TCA_POLICE_PEAKRATE-1]);
 219                         if (p->P_tab == NULL) {
 220                                 qdisc_put_rtab(R_tab);
 221                                 goto failure;
 222                         }
 223                 }
 224         }
 225         /* No failure allowed after this point */
 226         spin_lock_bh(&p->lock);
 227         if (R_tab != NULL) {
 228                 qdisc_put_rtab(p->R_tab);
 229                 p->R_tab = R_tab;
 230         }
 231         if (P_tab != NULL) {
 232                 qdisc_put_rtab(p->P_tab);
 233                 p->P_tab = P_tab;
 234         }
 235
 236         if (tb[TCA_POLICE_RESULT-1])
 237                 p->result = *(u32*)RTA_DATA(tb[TCA_POLICE_RESULT-1]);
 238         p->toks = p->burst = parm->burst;
 239         p->mtu = parm->mtu;
 240         if (p->mtu == 0) {
 241                 p->mtu = ~0;
 242                 if (p->R_tab)
 243                         p->mtu = 255<<p->R_tab->rate.cell_log;
 244         }
 245         if (p->P_tab)
 246                 p->ptoks = L2T_P(p, p->mtu);
 247         p->action = parm->action;
 248
 249 #ifdef CONFIG_NET_ESTIMATOR
 250         if (tb[TCA_POLICE_AVRATE-1])
 251                 p->ewma_rate = *(u32*)RTA_DATA(tb[TCA_POLICE_AVRATE-1]);
 252         if (est)
 253                 gen_replace_estimator(&p->bstats, &p->rate_est, p->stats_lock, est);
 254 #endif
 255
 256         spin_unlock_bh(&p->lock);
 257         if (ret != ACT_P_CREATED)
 258                 return ret;
 259
 260         PSCHED_GET_TIME(p->t_c);
 261         p->index = parm->index ? : tcf_police_new_index();
 262         h = tcf_police_hash(p->index);
 263         write_lock_bh(&police_lock);
 264         p->next = tcf_police_ht[h];
 265         tcf_police_ht[h] = p;
 266         write_unlock_bh(&police_lock);
 267
 268         a->priv = p;
 269         return ret;
 270
 271 failure:
 272         if (ret == ACT_P_CREATED)
 273                 kfree(p);
 274         return err;
 275 }
 276
 277 static int tcf_act_police_cleanup(struct tc_action *a, int bind)
 278 {
 279         struct tcf_police *p = PRIV(a);
 280
 281         if (p != NULL)
 282                 return tcf_police_release(p, bind);
 283         return 0;
 284 }
 285
 286 static int tcf_act_police(struct sk_buff *skb, struct tc_action *a,
 287                           struct tcf_result *res)
 288 {
 289         psched_time_t now;
 290         struct tcf_police *p = PRIV(a);
 291         long toks;
 292         long ptoks = 0;
 293
 294         spin_lock(&p->lock);
 295
 296         p->bstats.bytes += skb->len;
 297         p->bstats.packets++;
 298
 299 #ifdef CONFIG_NET_ESTIMATOR
 300         if (p->ewma_rate && p->rate_est.bps >= p->ewma_rate) {
 301                 p->qstats.overlimits++;
 302                 spin_unlock(&p->lock);
 303                 return p->action;
 304         }
 305 #endif
 306
 307         if (skb->len <= p->mtu) {
 308                 if (p->R_tab == NULL) {
 309                         spin_unlock(&p->lock);
 310                         return p->result;
 311                 }
 312
 313                 PSCHED_GET_TIME(now);
 314
 315                 toks = PSCHED_TDIFF_SAFE(now, p->t_c, p->burst);
 316
 317                 if (p->P_tab) {
 318                         ptoks = toks + p->ptoks;
 319                         if (ptoks > (long)L2T_P(p, p->mtu))
 320                                 ptoks = (long)L2T_P(p, p->mtu);
 321                         ptoks -= L2T_P(p, skb->len);
 322                 }
 323                 toks += p->toks;
 324                 if (toks > (long)p->burst)
 325                         toks = p->burst;
 326                 toks -= L2T(p, skb->len);
 327
 328                 if ((toks|ptoks) >= 0) {
 329                         p->t_c = now;
 330                         p->toks = toks;
 331                         p->ptoks = ptoks;
 332                         spin_unlock(&p->lock);
 333                         return p->result;
 334                 }
 335         }
 336
 337         p->qstats.overlimits++;
 338         spin_unlock(&p->lock);
 339         return p->action;
 340 }
 341
 342 static int
 343 tcf_act_police_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 344 {
 345         unsigned char    *b = skb->tail;
 346         struct tc_police opt;
 347         struct tcf_police *p = PRIV(a);
 348
 349         opt.index = p->index;
 350         opt.action = p->action;
 351         opt.mtu = p->mtu;
 352         opt.burst = p->burst;
 353         opt.refcnt = p->refcnt - ref;
 354         opt.bindcnt = p->bindcnt - bind;
 355         if (p->R_tab)
 356                 opt.rate = p->R_tab->rate;
 357         else
 358                 memset(&opt.rate, 0, sizeof(opt.rate));
 359         if (p->P_tab)
 360                 opt.peakrate = p->P_tab->rate;
 361         else
 362                 memset(&opt.peakrate, 0, sizeof(opt.peakrate));
 363         RTA_PUT(skb, TCA_POLICE_TBF, sizeof(opt), &opt);
 364         if (p->result)
 365                 RTA_PUT(skb, TCA_POLICE_RESULT, sizeof(int), &p->result);
 366 #ifdef CONFIG_NET_ESTIMATOR
 367         if (p->ewma_rate)
 368                 RTA_PUT(skb, TCA_POLICE_AVRATE, 4, &p->ewma_rate);
 369 #endif
 370         return skb->len;
 371
 372 rtattr_failure:
 373         skb_trim(skb, b - skb->data);
 374         return -1;
 375 }
 376
 377 MODULE_AUTHOR("Alexey Kuznetsov");
 378 MODULE_DESCRIPTION("Policing actions");
 379 MODULE_LICENSE("GPL");
 380
 381 static struct tc_action_ops act_police_ops = {
 382         .kind           =       "police",
 383         .type           =       TCA_ID_POLICE,
 384         .capab          =       TCA_CAP_NONE,
 385         .owner          =       THIS_MODULE,
 386         .act            =       tcf_act_police,
 387         .dump           =       tcf_act_police_dump,
 388         .cleanup        =       tcf_act_police_cleanup,
 389         .lookup         =       tcf_act_police_hash_search,
 390         .init           =       tcf_act_police_locate,
 391         .walk           =       tcf_act_police_walker
 392 };
 393
 394 static int __init
 395 police_init_module(void)
 396 {
 397         return tcf_register_action(&act_police_ops);
 398 }
 399
 400 static void __exit
 401 police_cleanup_module(void)
 402 {
 403         tcf_unregister_action(&act_police_ops);
 404 }
 405
 406 module_init(police_init_module);
 407 module_exit(police_cleanup_module);
 408
 409 #else /* CONFIG_NET_CLS_ACT */
 410
 411 struct tcf_police * tcf_police_locate(struct rtattr *rta, struct rtattr *est)
 412 {
 413         unsigned h;
 414         struct tcf_police *p;
 415         struct rtattr *tb[TCA_POLICE_MAX];
 416         struct tc_police *parm;
 417
 418         if (rtattr_parse_nested(tb, TCA_POLICE_MAX, rta) < 0)
 419                 return NULL;
 420
 421         if (tb[TCA_POLICE_TBF-1] == NULL ||
 422             RTA_PAYLOAD(tb[TCA_POLICE_TBF-1]) != sizeof(*parm))
 423                 return NULL;
 424
 425         parm = RTA_DATA(tb[TCA_POLICE_TBF-1]);
 426
 427         if (parm->index && (p = tcf_police_lookup(parm->index)) != NULL) {
 428                 p->refcnt++;
 429                 return p;
 430         }
 431
 432         p = kmalloc(sizeof(*p), GFP_KERNEL);
 433         if (p == NULL)
 434                 return NULL;
 435
 436         memset(p, 0, sizeof(*p));
 437         p->refcnt = 1;
 438         spin_lock_init(&p->lock);
 439         p->stats_lock = &p->lock;
 440         if (parm->rate.rate) {
 441                 p->R_tab = qdisc_get_rtab(&parm->rate, tb[TCA_POLICE_RATE-1]);
 442                 if (p->R_tab == NULL)
 443                         goto failure;
 444                 if (parm->peakrate.rate) {
 445                         p->P_tab = qdisc_get_rtab(&parm->peakrate,
 446                                                   tb[TCA_POLICE_PEAKRATE-1]);
 447                         if (p->P_tab == NULL)
 448                                 goto failure;
 449                 }
 450         }
 451         if (tb[TCA_POLICE_RESULT-1]) {
 452                 if (RTA_PAYLOAD(tb[TCA_POLICE_RESULT-1]) != sizeof(u32))
 453                         goto failure;
 454                 p->result = *(u32*)RTA_DATA(tb[TCA_POLICE_RESULT-1]);
 455         }
 456 #ifdef CONFIG_NET_ESTIMATOR
 457         if (tb[TCA_POLICE_AVRATE-1]) {
 458                 if (RTA_PAYLOAD(tb[TCA_POLICE_AVRATE-1]) != sizeof(u32))
 459                         goto failure;
 460                 p->ewma_rate = *(u32*)RTA_DATA(tb[TCA_POLICE_AVRATE-1]);
 461         }
 462 #endif
 463         p->toks = p->burst = parm->burst;
 464         p->mtu = parm->mtu;
 465         if (p->mtu == 0) {
 466                 p->mtu = ~0;
 467                 if (p->R_tab)
 468                         p->mtu = 255<<p->R_tab->rate.cell_log;
 469         }
 470         if (p->P_tab)
 471                 p->ptoks = L2T_P(p, p->mtu);
 472         PSCHED_GET_TIME(p->t_c);
 473         p->index = parm->index ? : tcf_police_new_index();
 474         p->action = parm->action;
 475 #ifdef CONFIG_NET_ESTIMATOR
 476         if (est)
 477                 gen_new_estimator(&p->bstats, &p->rate_est, p->stats_lock, est);
 478 #endif
 479         h = tcf_police_hash(p->index);
 480         write_lock_bh(&police_lock);
 481         p->next = tcf_police_ht[h];
 482         tcf_police_ht[h] = p;
 483         write_unlock_bh(&police_lock);
 484         return p;
 485
 486 failure:
 487         if (p->R_tab)
 488                 qdisc_put_rtab(p->R_tab);
 489         kfree(p);
 490         return NULL;
 491 }
 492
 493 int tcf_police(struct sk_buff *skb, struct tcf_police *p)
 494 {
 495         psched_time_t now;
 496         long toks;
 497         long ptoks = 0;
 498
 499         spin_lock(&p->lock);
 500
 501         p->bstats.bytes += skb->len;
 502         p->bstats.packets++;
 503
 504 #ifdef CONFIG_NET_ESTIMATOR
 505         if (p->ewma_rate && p->rate_est.bps >= p->ewma_rate) {
 506                 p->qstats.overlimits++;
 507                 spin_unlock(&p->lock);
 508                 return p->action;
 509         }
 510 #endif
 511
 512         if (skb->len <= p->mtu) {
 513                 if (p->R_tab == NULL) {
 514                         spin_unlock(&p->lock);
 515                         return p->result;
 516                 }
 517
 518                 PSCHED_GET_TIME(now);
 519
 520                 toks = PSCHED_TDIFF_SAFE(now, p->t_c, p->burst);
 521
 522                 if (p->P_tab) {
 523                         ptoks = toks + p->ptoks;
 524                         if (ptoks > (long)L2T_P(p, p->mtu))
 525                                 ptoks = (long)L2T_P(p, p->mtu);
 526                         ptoks -= L2T_P(p, skb->len);
 527                 }
 528                 toks += p->toks;
 529                 if (toks > (long)p->burst)
 530                         toks = p->burst;
 531                 toks -= L2T(p, skb->len);
 532
 533                 if ((toks|ptoks) >= 0) {
 534                         p->t_c = now;
 535                         p->toks = toks;
 536                         p->ptoks = ptoks;
 537                         spin_unlock(&p->lock);
 538                         return p->result;
 539                 }
 540         }
 541
 542         p->qstats.overlimits++;
 543         spin_unlock(&p->lock);
 544         return p->action;
 545 }
 546 EXPORT_SYMBOL(tcf_police);
 547
 548 int tcf_police_dump(struct sk_buff *skb, struct tcf_police *p)
 549 {
 550         unsigned char    *b = skb->tail;
 551         struct tc_police opt;
 552
 553         opt.index = p->index;
 554         opt.action = p->action;
 555         opt.mtu = p->mtu;
 556         opt.burst = p->burst;
 557         if (p->R_tab)
 558                 opt.rate = p->R_tab->rate;
 559         else
 560                 memset(&opt.rate, 0, sizeof(opt.rate));
 561         if (p->P_tab)
 562                 opt.peakrate = p->P_tab->rate;
 563         else
 564                 memset(&opt.peakrate, 0, sizeof(opt.peakrate));
 565         RTA_PUT(skb, TCA_POLICE_TBF, sizeof(opt), &opt);
 566         if (p->result)
 567                 RTA_PUT(skb, TCA_POLICE_RESULT, sizeof(int), &p->result);
 568 #ifdef CONFIG_NET_ESTIMATOR
 569         if (p->ewma_rate)
 570                 RTA_PUT(skb, TCA_POLICE_AVRATE, 4, &p->ewma_rate);
 571 #endif
 572         return skb->len;
 573
 574 rtattr_failure:
 575         skb_trim(skb, b - skb->data);
 576         return -1;
 577 }
 578
 579 int tcf_police_dump_stats(struct sk_buff *skb, struct tcf_police *p)
 580 {
 581         struct gnet_dump d;
 582
 583         if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS,
 584                         TCA_XSTATS, p->stats_lock, &d) < 0)
 585                 goto errout;
 586
 587         if (gnet_stats_copy_basic(&d, &p->bstats) < 0 ||
 588 #ifdef CONFIG_NET_ESTIMATOR
 589             gnet_stats_copy_rate_est(&d, &p->rate_est) < 0 ||
 590 #endif
 591             gnet_stats_copy_queue(&d, &p->qstats) < 0)
 592                 goto errout;
 593
 594         if (gnet_stats_finish_copy(&d) < 0)
 595                 goto errout;
 596
 597         return 0;
 598
 599 errout:
 600         return -1;
 601 }
 602
 603 #endif /* CONFIG_NET_CLS_ACT */