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   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 = kzalloc(sizeof(*p), GFP_KERNEL);
 200         if (p == NULL)
 201                 return -ENOMEM;
 202
 203         ret = ACT_P_CREATED;
 204         p->refcnt = 1;
 205         spin_lock_init(&p->lock);
 206         p->stats_lock = &p->lock;
 207         if (bind)
 208                 p->bindcnt = 1;
 209 override:
 210         if (parm->rate.rate) {
 211                 err = -ENOMEM;
 212                 R_tab = qdisc_get_rtab(&parm->rate, tb[TCA_POLICE_RATE-1]);
 213                 if (R_tab == NULL)
 214                         goto failure;
 215                 if (parm->peakrate.rate) {
 216                         P_tab = qdisc_get_rtab(&parm->peakrate,
 217                                                tb[TCA_POLICE_PEAKRATE-1]);
 218                         if (p->P_tab == NULL) {
 219                                 qdisc_put_rtab(R_tab);
 220                                 goto failure;
 221                         }
 222                 }
 223         }
 224         /* No failure allowed after this point */
 225         spin_lock_bh(&p->lock);
 226         if (R_tab != NULL) {
 227                 qdisc_put_rtab(p->R_tab);
 228                 p->R_tab = R_tab;
 229         }
 230         if (P_tab != NULL) {
 231                 qdisc_put_rtab(p->P_tab);
 232                 p->P_tab = P_tab;
 233         }
 234
 235         if (tb[TCA_POLICE_RESULT-1])
 236                 p->result = *(u32*)RTA_DATA(tb[TCA_POLICE_RESULT-1]);
 237         p->toks = p->burst = parm->burst;
 238         p->mtu = parm->mtu;
 239         if (p->mtu == 0) {
 240                 p->mtu = ~0;
 241                 if (p->R_tab)
 242                         p->mtu = 255<<p->R_tab->rate.cell_log;
 243         }
 244         if (p->P_tab)
 245                 p->ptoks = L2T_P(p, p->mtu);
 246         p->action = parm->action;
 247
 248 #ifdef CONFIG_NET_ESTIMATOR
 249         if (tb[TCA_POLICE_AVRATE-1])
 250                 p->ewma_rate = *(u32*)RTA_DATA(tb[TCA_POLICE_AVRATE-1]);
 251         if (est)
 252                 gen_replace_estimator(&p->bstats, &p->rate_est, p->stats_lock, est);
 253 #endif
 254
 255         spin_unlock_bh(&p->lock);
 256         if (ret != ACT_P_CREATED)
 257                 return ret;
 258
 259         PSCHED_GET_TIME(p->t_c);
 260         p->index = parm->index ? : tcf_police_new_index();
 261         h = tcf_police_hash(p->index);
 262         write_lock_bh(&police_lock);
 263         p->next = tcf_police_ht[h];
 264         tcf_police_ht[h] = p;
 265         write_unlock_bh(&police_lock);
 266
 267         a->priv = p;
 268         return ret;
 269
 270 failure:
 271         if (ret == ACT_P_CREATED)
 272                 kfree(p);
 273         return err;
 274 }
 275
 276 static int tcf_act_police_cleanup(struct tc_action *a, int bind)
 277 {
 278         struct tcf_police *p = PRIV(a);
 279
 280         if (p != NULL)
 281                 return tcf_police_release(p, bind);
 282         return 0;
 283 }
 284
 285 static int tcf_act_police(struct sk_buff *skb, struct tc_action *a,
 286                           struct tcf_result *res)
 287 {
 288         psched_time_t now;
 289         struct tcf_police *p = PRIV(a);
 290         long toks;
 291         long ptoks = 0;
 292
 293         spin_lock(&p->lock);
 294
 295         p->bstats.bytes += skb->len;
 296         p->bstats.packets++;
 297
 298 #ifdef CONFIG_NET_ESTIMATOR
 299         if (p->ewma_rate && p->rate_est.bps >= p->ewma_rate) {
 300                 p->qstats.overlimits++;
 301                 spin_unlock(&p->lock);
 302                 return p->action;
 303         }
 304 #endif
 305
 306         if (skb->len <= p->mtu) {
 307                 if (p->R_tab == NULL) {
 308                         spin_unlock(&p->lock);
 309                         return p->result;
 310                 }
 311
 312                 PSCHED_GET_TIME(now);
 313
 314                 toks = PSCHED_TDIFF_SAFE(now, p->t_c, p->burst);
 315
 316                 if (p->P_tab) {
 317                         ptoks = toks + p->ptoks;
 318                         if (ptoks > (long)L2T_P(p, p->mtu))
 319                                 ptoks = (long)L2T_P(p, p->mtu);
 320                         ptoks -= L2T_P(p, skb->len);
 321                 }
 322                 toks += p->toks;
 323                 if (toks > (long)p->burst)
 324                         toks = p->burst;
 325                 toks -= L2T(p, skb->len);
 326
 327                 if ((toks|ptoks) >= 0) {
 328                         p->t_c = now;
 329                         p->toks = toks;
 330                         p->ptoks = ptoks;
 331                         spin_unlock(&p->lock);
 332                         return p->result;
 333                 }
 334         }
 335
 336         p->qstats.overlimits++;
 337         spin_unlock(&p->lock);
 338         return p->action;
 339 }
 340
 341 static int
 342 tcf_act_police_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 343 {
 344         unsigned char    *b = skb->tail;
 345         struct tc_police opt;
 346         struct tcf_police *p = PRIV(a);
 347
 348         opt.index = p->index;
 349         opt.action = p->action;
 350         opt.mtu = p->mtu;
 351         opt.burst = p->burst;
 352         opt.refcnt = p->refcnt - ref;
 353         opt.bindcnt = p->bindcnt - bind;
 354         if (p->R_tab)
 355                 opt.rate = p->R_tab->rate;
 356         else
 357                 memset(&opt.rate, 0, sizeof(opt.rate));
 358         if (p->P_tab)
 359                 opt.peakrate = p->P_tab->rate;
 360         else
 361                 memset(&opt.peakrate, 0, sizeof(opt.peakrate));
 362         RTA_PUT(skb, TCA_POLICE_TBF, sizeof(opt), &opt);
 363         if (p->result)
 364                 RTA_PUT(skb, TCA_POLICE_RESULT, sizeof(int), &p->result);
 365 #ifdef CONFIG_NET_ESTIMATOR
 366         if (p->ewma_rate)
 367                 RTA_PUT(skb, TCA_POLICE_AVRATE, 4, &p->ewma_rate);
 368 #endif
 369         return skb->len;
 370
 371 rtattr_failure:
 372         skb_trim(skb, b - skb->data);
 373         return -1;
 374 }
 375
 376 MODULE_AUTHOR("Alexey Kuznetsov");
 377 MODULE_DESCRIPTION("Policing actions");
 378 MODULE_LICENSE("GPL");
 379
 380 static struct tc_action_ops act_police_ops = {
 381         .kind           =       "police",
 382         .type           =       TCA_ID_POLICE,
 383         .capab          =       TCA_CAP_NONE,
 384         .owner          =       THIS_MODULE,
 385         .act            =       tcf_act_police,
 386         .dump           =       tcf_act_police_dump,
 387         .cleanup        =       tcf_act_police_cleanup,
 388         .lookup         =       tcf_act_police_hash_search,
 389         .init           =       tcf_act_police_locate,
 390         .walk           =       tcf_act_police_walker
 391 };
 392
 393 static int __init
 394 police_init_module(void)
 395 {
 396         return tcf_register_action(&act_police_ops);
 397 }
 398
 399 static void __exit
 400 police_cleanup_module(void)
 401 {
 402         tcf_unregister_action(&act_police_ops);
 403 }
 404
 405 module_init(police_init_module);
 406 module_exit(police_cleanup_module);
 407
 408 #else /* CONFIG_NET_CLS_ACT */
 409
 410 struct tcf_police * tcf_police_locate(struct rtattr *rta, struct rtattr *est)
 411 {
 412         unsigned h;
 413         struct tcf_police *p;
 414         struct rtattr *tb[TCA_POLICE_MAX];
 415         struct tc_police *parm;
 416
 417         if (rtattr_parse_nested(tb, TCA_POLICE_MAX, rta) < 0)
 418                 return NULL;
 419
 420         if (tb[TCA_POLICE_TBF-1] == NULL ||
 421             RTA_PAYLOAD(tb[TCA_POLICE_TBF-1]) != sizeof(*parm))
 422                 return NULL;
 423
 424         parm = RTA_DATA(tb[TCA_POLICE_TBF-1]);
 425
 426         if (parm->index && (p = tcf_police_lookup(parm->index)) != NULL) {
 427                 p->refcnt++;
 428                 return p;
 429         }
 430
 431         p = kzalloc(sizeof(*p), GFP_KERNEL);
 432         if (p == NULL)
 433                 return NULL;
 434
 435         p->refcnt = 1;
 436         spin_lock_init(&p->lock);
 437         p->stats_lock = &p->lock;
 438         if (parm->rate.rate) {
 439                 p->R_tab = qdisc_get_rtab(&parm->rate, tb[TCA_POLICE_RATE-1]);
 440                 if (p->R_tab == NULL)
 441                         goto failure;
 442                 if (parm->peakrate.rate) {
 443                         p->P_tab = qdisc_get_rtab(&parm->peakrate,
 444                                                   tb[TCA_POLICE_PEAKRATE-1]);
 445                         if (p->P_tab == NULL)
 446                                 goto failure;
 447                 }
 448         }
 449         if (tb[TCA_POLICE_RESULT-1]) {
 450                 if (RTA_PAYLOAD(tb[TCA_POLICE_RESULT-1]) != sizeof(u32))
 451                         goto failure;
 452                 p->result = *(u32*)RTA_DATA(tb[TCA_POLICE_RESULT-1]);
 453         }
 454 #ifdef CONFIG_NET_ESTIMATOR
 455         if (tb[TCA_POLICE_AVRATE-1]) {
 456                 if (RTA_PAYLOAD(tb[TCA_POLICE_AVRATE-1]) != sizeof(u32))
 457                         goto failure;
 458                 p->ewma_rate = *(u32*)RTA_DATA(tb[TCA_POLICE_AVRATE-1]);
 459         }
 460 #endif
 461         p->toks = p->burst = parm->burst;
 462         p->mtu = parm->mtu;
 463         if (p->mtu == 0) {
 464                 p->mtu = ~0;
 465                 if (p->R_tab)
 466                         p->mtu = 255<<p->R_tab->rate.cell_log;
 467         }
 468         if (p->P_tab)
 469                 p->ptoks = L2T_P(p, p->mtu);
 470         PSCHED_GET_TIME(p->t_c);
 471         p->index = parm->index ? : tcf_police_new_index();
 472         p->action = parm->action;
 473 #ifdef CONFIG_NET_ESTIMATOR
 474         if (est)
 475                 gen_new_estimator(&p->bstats, &p->rate_est, p->stats_lock, est);
 476 #endif
 477         h = tcf_police_hash(p->index);
 478         write_lock_bh(&police_lock);
 479         p->next = tcf_police_ht[h];
 480         tcf_police_ht[h] = p;
 481         write_unlock_bh(&police_lock);
 482         return p;
 483
 484 failure:
 485         if (p->R_tab)
 486                 qdisc_put_rtab(p->R_tab);
 487         kfree(p);
 488         return NULL;
 489 }
 490
 491 int tcf_police(struct sk_buff *skb, struct tcf_police *p)
 492 {
 493         psched_time_t now;
 494         long toks;
 495         long ptoks = 0;
 496
 497         spin_lock(&p->lock);
 498
 499         p->bstats.bytes += skb->len;
 500         p->bstats.packets++;
 501
 502 #ifdef CONFIG_NET_ESTIMATOR
 503         if (p->ewma_rate && p->rate_est.bps >= p->ewma_rate) {
 504                 p->qstats.overlimits++;
 505                 spin_unlock(&p->lock);
 506                 return p->action;
 507         }
 508 #endif
 509
 510         if (skb->len <= p->mtu) {
 511                 if (p->R_tab == NULL) {
 512                         spin_unlock(&p->lock);
 513                         return p->result;
 514                 }
 515
 516                 PSCHED_GET_TIME(now);
 517
 518                 toks = PSCHED_TDIFF_SAFE(now, p->t_c, p->burst);
 519
 520                 if (p->P_tab) {
 521                         ptoks = toks + p->ptoks;
 522                         if (ptoks > (long)L2T_P(p, p->mtu))
 523                                 ptoks = (long)L2T_P(p, p->mtu);
 524                         ptoks -= L2T_P(p, skb->len);
 525                 }
 526                 toks += p->toks;
 527                 if (toks > (long)p->burst)
 528                         toks = p->burst;
 529                 toks -= L2T(p, skb->len);
 530
 531                 if ((toks|ptoks) >= 0) {
 532                         p->t_c = now;
 533                         p->toks = toks;
 534                         p->ptoks = ptoks;
 535                         spin_unlock(&p->lock);
 536                         return p->result;
 537                 }
 538         }
 539
 540         p->qstats.overlimits++;
 541         spin_unlock(&p->lock);
 542         return p->action;
 543 }
 544 EXPORT_SYMBOL(tcf_police);
 545
 546 int tcf_police_dump(struct sk_buff *skb, struct tcf_police *p)
 547 {
 548         unsigned char    *b = skb->tail;
 549         struct tc_police opt;
 550
 551         opt.index = p->index;
 552         opt.action = p->action;
 553         opt.mtu = p->mtu;
 554         opt.burst = p->burst;
 555         if (p->R_tab)
 556                 opt.rate = p->R_tab->rate;
 557         else
 558                 memset(&opt.rate, 0, sizeof(opt.rate));
 559         if (p->P_tab)
 560                 opt.peakrate = p->P_tab->rate;
 561         else
 562                 memset(&opt.peakrate, 0, sizeof(opt.peakrate));
 563         RTA_PUT(skb, TCA_POLICE_TBF, sizeof(opt), &opt);
 564         if (p->result)
 565                 RTA_PUT(skb, TCA_POLICE_RESULT, sizeof(int), &p->result);
 566 #ifdef CONFIG_NET_ESTIMATOR
 567         if (p->ewma_rate)
 568                 RTA_PUT(skb, TCA_POLICE_AVRATE, 4, &p->ewma_rate);
 569 #endif
 570         return skb->len;
 571
 572 rtattr_failure:
 573         skb_trim(skb, b - skb->data);
 574         return -1;
 575 }
 576
 577 int tcf_police_dump_stats(struct sk_buff *skb, struct tcf_police *p)
 578 {
 579         struct gnet_dump d;
 580
 581         if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS,
 582                         TCA_XSTATS, p->stats_lock, &d) < 0)
 583                 goto errout;
 584
 585         if (gnet_stats_copy_basic(&d, &p->bstats) < 0 ||
 586 #ifdef CONFIG_NET_ESTIMATOR
 587             gnet_stats_copy_rate_est(&d, &p->rate_est) < 0 ||
 588 #endif
 589             gnet_stats_copy_queue(&d, &p->qstats) < 0)
 590                 goto errout;
 591
 592         if (gnet_stats_finish_copy(&d) < 0)
 593                 goto errout;
 594
 595         return 0;
 596
 597 errout:
 598         return -1;
 599 }
 600
 601 #endif /* CONFIG_NET_CLS_ACT */