net/sched/act_gate.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* Copyright 2020 NXP */
   3
   4 #include <linux/module.h>
   5 #include <linux/types.h>
   6 #include <linux/kernel.h>
   7 #include <linux/string.h>
   8 #include <linux/errno.h>
   9 #include <linux/skbuff.h>
  10 #include <linux/rtnetlink.h>
  11 #include <linux/init.h>
  12 #include <linux/slab.h>
  13 #include <net/act_api.h>
  14 #include <net/netlink.h>
  15 #include <net/pkt_cls.h>
  16 #include <net/tc_act/tc_gate.h>
  17
  18 static unsigned int gate_net_id;
  19 static struct tc_action_ops act_gate_ops;
  20
  21 static ktime_t gate_get_time(struct tcf_gate *gact)
  22 {
  23         ktime_t mono = ktime_get();
  24
  25         switch (gact->tk_offset) {
  26         case TK_OFFS_MAX:
  27                 return mono;
  28         default:
  29                 return ktime_mono_to_any(mono, gact->tk_offset);
  30         }
  31
  32         return KTIME_MAX;
  33 }
  34
  35 static void gate_get_start_time(struct tcf_gate *gact, ktime_t *start)
  36 {
  37         struct tcf_gate_params *param = &gact->param;
  38         ktime_t now, base, cycle;
  39         u64 n;
  40
  41         base = ns_to_ktime(param->tcfg_basetime);
  42         now = gate_get_time(gact);
  43
  44         if (ktime_after(base, now)) {
  45                 *start = base;
  46                 return;
  47         }
  48
  49         cycle = param->tcfg_cycletime;
  50
  51         n = div64_u64(ktime_sub_ns(now, base), cycle);
  52         *start = ktime_add_ns(base, (n + 1) * cycle);
  53 }
  54
  55 static void gate_start_timer(struct tcf_gate *gact, ktime_t start)
  56 {
  57         ktime_t expires;
  58
  59         expires = hrtimer_get_expires(&gact->hitimer);
  60         if (expires == 0)
  61                 expires = KTIME_MAX;
  62
  63         start = min_t(ktime_t, start, expires);
  64
  65         hrtimer_start(&gact->hitimer, start, HRTIMER_MODE_ABS_SOFT);
  66 }
  67
  68 static enum hrtimer_restart gate_timer_func(struct hrtimer *timer)
  69 {
  70         struct tcf_gate *gact = container_of(timer, struct tcf_gate,
  71                                              hitimer);
  72         struct tcf_gate_params *p = &gact->param;
  73         struct tcfg_gate_entry *next;
  74         ktime_t close_time, now;
  75
  76         spin_lock(&gact->tcf_lock);
  77
  78         next = gact->next_entry;
  79
  80         /* cycle start, clear pending bit, clear total octets */
  81         gact->current_gate_status = next->gate_state ? GATE_ACT_GATE_OPEN : 0;
  82         gact->current_entry_octets = 0;
  83         gact->current_max_octets = next->maxoctets;
  84
  85         gact->current_close_time = ktime_add_ns(gact->current_close_time,
  86                                                 next->interval);
  87
  88         close_time = gact->current_close_time;
  89
  90         if (list_is_last(&next->list, &p->entries))
  91                 next = list_first_entry(&p->entries,
  92                                         struct tcfg_gate_entry, list);
  93         else
  94                 next = list_next_entry(next, list);
  95
  96         now = gate_get_time(gact);
  97
  98         if (ktime_after(now, close_time)) {
  99                 ktime_t cycle, base;
 100                 u64 n;
 101
 102                 cycle = p->tcfg_cycletime;
 103                 base = ns_to_ktime(p->tcfg_basetime);
 104                 n = div64_u64(ktime_sub_ns(now, base), cycle);
 105                 close_time = ktime_add_ns(base, (n + 1) * cycle);
 106         }
 107
 108         gact->next_entry = next;
 109
 110         hrtimer_set_expires(&gact->hitimer, close_time);
 111
 112         spin_unlock(&gact->tcf_lock);
 113
 114         return HRTIMER_RESTART;
 115 }
 116
 117 static int tcf_gate_act(struct sk_buff *skb, const struct tc_action *a,
 118                         struct tcf_result *res)
 119 {
 120         struct tcf_gate *gact = to_gate(a);
 121
 122         spin_lock(&gact->tcf_lock);
 123
 124         tcf_lastuse_update(&gact->tcf_tm);
 125         bstats_update(&gact->tcf_bstats, skb);
 126
 127         if (unlikely(gact->current_gate_status & GATE_ACT_PENDING)) {
 128                 spin_unlock(&gact->tcf_lock);
 129                 return gact->tcf_action;
 130         }
 131
 132         if (!(gact->current_gate_status & GATE_ACT_GATE_OPEN))
 133                 goto drop;
 134
 135         if (gact->current_max_octets >= 0) {
 136                 gact->current_entry_octets += qdisc_pkt_len(skb);
 137                 if (gact->current_entry_octets > gact->current_max_octets) {
 138                         gact->tcf_qstats.overlimits++;
 139                         goto drop;
 140                 }
 141         }
 142
 143         spin_unlock(&gact->tcf_lock);
 144
 145         return gact->tcf_action;
 146 drop:
 147         gact->tcf_qstats.drops++;
 148         spin_unlock(&gact->tcf_lock);
 149
 150         return TC_ACT_SHOT;
 151 }
 152
 153 static const struct nla_policy entry_policy[TCA_GATE_ENTRY_MAX + 1] = {
 154         [TCA_GATE_ENTRY_INDEX]          = { .type = NLA_U32 },
 155         [TCA_GATE_ENTRY_GATE]           = { .type = NLA_FLAG },
 156         [TCA_GATE_ENTRY_INTERVAL]       = { .type = NLA_U32 },
 157         [TCA_GATE_ENTRY_IPV]            = { .type = NLA_S32 },
 158         [TCA_GATE_ENTRY_MAX_OCTETS]     = { .type = NLA_S32 },
 159 };
 160
 161 static const struct nla_policy gate_policy[TCA_GATE_MAX + 1] = {
 162         [TCA_GATE_PARMS]                =
 163                 NLA_POLICY_EXACT_LEN(sizeof(struct tc_gate)),
 164         [TCA_GATE_PRIORITY]             = { .type = NLA_S32 },
 165         [TCA_GATE_ENTRY_LIST]           = { .type = NLA_NESTED },
 166         [TCA_GATE_BASE_TIME]            = { .type = NLA_U64 },
 167         [TCA_GATE_CYCLE_TIME]           = { .type = NLA_U64 },
 168         [TCA_GATE_CYCLE_TIME_EXT]       = { .type = NLA_U64 },
 169         [TCA_GATE_FLAGS]                = { .type = NLA_U32 },
 170         [TCA_GATE_CLOCKID]              = { .type = NLA_S32 },
 171 };
 172
 173 static int fill_gate_entry(struct nlattr **tb, struct tcfg_gate_entry *entry,
 174                            struct netlink_ext_ack *extack)
 175 {
 176         u32 interval = 0;
 177
 178         entry->gate_state = nla_get_flag(tb[TCA_GATE_ENTRY_GATE]);
 179
 180         if (tb[TCA_GATE_ENTRY_INTERVAL])
 181                 interval = nla_get_u32(tb[TCA_GATE_ENTRY_INTERVAL]);
 182
 183         if (interval == 0) {
 184                 NL_SET_ERR_MSG(extack, "Invalid interval for schedule entry");
 185                 return -EINVAL;
 186         }
 187
 188         entry->interval = interval;
 189
 190         if (tb[TCA_GATE_ENTRY_IPV])
 191                 entry->ipv = nla_get_s32(tb[TCA_GATE_ENTRY_IPV]);
 192         else
 193                 entry->ipv = -1;
 194
 195         if (tb[TCA_GATE_ENTRY_MAX_OCTETS])
 196                 entry->maxoctets = nla_get_s32(tb[TCA_GATE_ENTRY_MAX_OCTETS]);
 197         else
 198                 entry->maxoctets = -1;
 199
 200         return 0;
 201 }
 202
 203 static int parse_gate_entry(struct nlattr *n, struct  tcfg_gate_entry *entry,
 204                             int index, struct netlink_ext_ack *extack)
 205 {
 206         struct nlattr *tb[TCA_GATE_ENTRY_MAX + 1] = { };
 207         int err;
 208
 209         err = nla_parse_nested(tb, TCA_GATE_ENTRY_MAX, n, entry_policy, extack);
 210         if (err < 0) {
 211                 NL_SET_ERR_MSG(extack, "Could not parse nested entry");
 212                 return -EINVAL;
 213         }
 214
 215         entry->index = index;
 216
 217         return fill_gate_entry(tb, entry, extack);
 218 }
 219
 220 static void release_entry_list(struct list_head *entries)
 221 {
 222         struct tcfg_gate_entry *entry, *e;
 223
 224         list_for_each_entry_safe(entry, e, entries, list) {
 225                 list_del(&entry->list);
 226                 kfree(entry);
 227         }
 228 }
 229
 230 static int parse_gate_list(struct nlattr *list_attr,
 231                            struct tcf_gate_params *sched,
 232                            struct netlink_ext_ack *extack)
 233 {
 234         struct tcfg_gate_entry *entry;
 235         struct nlattr *n;
 236         int err, rem;
 237         int i = 0;
 238
 239         if (!list_attr)
 240                 return -EINVAL;
 241
 242         nla_for_each_nested(n, list_attr, rem) {
 243                 if (nla_type(n) != TCA_GATE_ONE_ENTRY) {
 244                         NL_SET_ERR_MSG(extack, "Attribute isn't type 'entry'");
 245                         continue;
 246                 }
 247
 248                 entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
 249                 if (!entry) {
 250                         NL_SET_ERR_MSG(extack, "Not enough memory for entry");
 251                         err = -ENOMEM;
 252                         goto release_list;
 253                 }
 254
 255                 err = parse_gate_entry(n, entry, i, extack);
 256                 if (err < 0) {
 257                         kfree(entry);
 258                         goto release_list;
 259                 }
 260
 261                 list_add_tail(&entry->list, &sched->entries);
 262                 i++;
 263         }
 264
 265         sched->num_entries = i;
 266
 267         return i;
 268
 269 release_list:
 270         release_entry_list(&sched->entries);
 271
 272         return err;
 273 }
 274
 275 static void gate_setup_timer(struct tcf_gate *gact, u64 basetime,
 276                              enum tk_offsets tko, s32 clockid,
 277                              bool do_init)
 278 {
 279         if (!do_init) {
 280                 if (basetime == gact->param.tcfg_basetime &&
 281                     tko == gact->tk_offset &&
 282                     clockid == gact->param.tcfg_clockid)
 283                         return;
 284
 285                 spin_unlock_bh(&gact->tcf_lock);
 286                 hrtimer_cancel(&gact->hitimer);
 287                 spin_lock_bh(&gact->tcf_lock);
 288         }
 289         gact->param.tcfg_basetime = basetime;
 290         gact->param.tcfg_clockid = clockid;
 291         gact->tk_offset = tko;
 292         hrtimer_init(&gact->hitimer, clockid, HRTIMER_MODE_ABS_SOFT);
 293         gact->hitimer.function = gate_timer_func;
 294 }
 295
 296 static int tcf_gate_init(struct net *net, struct nlattr *nla,
 297                          struct nlattr *est, struct tc_action **a,
 298                          struct tcf_proto *tp, u32 flags,
 299                          struct netlink_ext_ack *extack)
 300 {
 301         struct tc_action_net *tn = net_generic(net, gate_net_id);
 302         enum tk_offsets tk_offset = TK_OFFS_TAI;
 303         bool bind = flags & TCA_ACT_FLAGS_BIND;
 304         struct nlattr *tb[TCA_GATE_MAX + 1];
 305         struct tcf_chain *goto_ch = NULL;
 306         u64 cycletime = 0, basetime = 0;
 307         struct tcf_gate_params *p;
 308         s32 clockid = CLOCK_TAI;
 309         struct tcf_gate *gact;
 310         struct tc_gate *parm;
 311         int ret = 0, err;
 312         u32 gflags = 0;
 313         s32 prio = -1;
 314         ktime_t start;
 315         u32 index;
 316
 317         if (!nla)
 318                 return -EINVAL;
 319
 320         err = nla_parse_nested(tb, TCA_GATE_MAX, nla, gate_policy, extack);
 321         if (err < 0)
 322                 return err;
 323
 324         if (!tb[TCA_GATE_PARMS])
 325                 return -EINVAL;
 326
 327         if (tb[TCA_GATE_CLOCKID]) {
 328                 clockid = nla_get_s32(tb[TCA_GATE_CLOCKID]);
 329                 switch (clockid) {
 330                 case CLOCK_REALTIME:
 331                         tk_offset = TK_OFFS_REAL;
 332                         break;
 333                 case CLOCK_MONOTONIC:
 334                         tk_offset = TK_OFFS_MAX;
 335                         break;
 336                 case CLOCK_BOOTTIME:
 337                         tk_offset = TK_OFFS_BOOT;
 338                         break;
 339                 case CLOCK_TAI:
 340                         tk_offset = TK_OFFS_TAI;
 341                         break;
 342                 default:
 343                         NL_SET_ERR_MSG(extack, "Invalid 'clockid'");
 344                         return -EINVAL;
 345                 }
 346         }
 347
 348         parm = nla_data(tb[TCA_GATE_PARMS]);
 349         index = parm->index;
 350
 351         err = tcf_idr_check_alloc(tn, &index, a, bind);
 352         if (err < 0)
 353                 return err;
 354
 355         if (err && bind)
 356                 return 0;
 357
 358         if (!err) {
 359                 ret = tcf_idr_create(tn, index, est, a,
 360                                      &act_gate_ops, bind, false, 0);
 361                 if (ret) {
 362                         tcf_idr_cleanup(tn, index);
 363                         return ret;
 364                 }
 365
 366                 ret = ACT_P_CREATED;
 367         } else if (!(flags & TCA_ACT_FLAGS_REPLACE)) {
 368                 tcf_idr_release(*a, bind);
 369                 return -EEXIST;
 370         }
 371
 372         if (tb[TCA_GATE_PRIORITY])
 373                 prio = nla_get_s32(tb[TCA_GATE_PRIORITY]);
 374
 375         if (tb[TCA_GATE_BASE_TIME])
 376                 basetime = nla_get_u64(tb[TCA_GATE_BASE_TIME]);
 377
 378         if (tb[TCA_GATE_FLAGS])
 379                 gflags = nla_get_u32(tb[TCA_GATE_FLAGS]);
 380
 381         gact = to_gate(*a);
 382         if (ret == ACT_P_CREATED)
 383                 INIT_LIST_HEAD(&gact->param.entries);
 384
 385         err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
 386         if (err < 0)
 387                 goto release_idr;
 388
 389         spin_lock_bh(&gact->tcf_lock);
 390         p = &gact->param;
 391
 392         if (tb[TCA_GATE_CYCLE_TIME])
 393                 cycletime = nla_get_u64(tb[TCA_GATE_CYCLE_TIME]);
 394
 395         if (tb[TCA_GATE_ENTRY_LIST]) {
 396                 err = parse_gate_list(tb[TCA_GATE_ENTRY_LIST], p, extack);
 397                 if (err < 0)
 398                         goto chain_put;
 399         }
 400
 401         if (!cycletime) {
 402                 struct tcfg_gate_entry *entry;
 403                 ktime_t cycle = 0;
 404
 405                 list_for_each_entry(entry, &p->entries, list)
 406                         cycle = ktime_add_ns(cycle, entry->interval);
 407                 cycletime = cycle;
 408                 if (!cycletime) {
 409                         err = -EINVAL;
 410                         goto chain_put;
 411                 }
 412         }
 413         p->tcfg_cycletime = cycletime;
 414
 415         if (tb[TCA_GATE_CYCLE_TIME_EXT])
 416                 p->tcfg_cycletime_ext =
 417                         nla_get_u64(tb[TCA_GATE_CYCLE_TIME_EXT]);
 418
 419         gate_setup_timer(gact, basetime, tk_offset, clockid,
 420                          ret == ACT_P_CREATED);
 421         p->tcfg_priority = prio;
 422         p->tcfg_flags = gflags;
 423         gate_get_start_time(gact, &start);
 424
 425         gact->current_close_time = start;
 426         gact->current_gate_status = GATE_ACT_GATE_OPEN | GATE_ACT_PENDING;
 427
 428         gact->next_entry = list_first_entry(&p->entries,
 429                                             struct tcfg_gate_entry, list);
 430
 431         goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
 432
 433         gate_start_timer(gact, start);
 434
 435         spin_unlock_bh(&gact->tcf_lock);
 436
 437         if (goto_ch)
 438                 tcf_chain_put_by_act(goto_ch);
 439
 440         return ret;
 441
 442 chain_put:
 443         spin_unlock_bh(&gact->tcf_lock);
 444
 445         if (goto_ch)
 446                 tcf_chain_put_by_act(goto_ch);
 447 release_idr:
 448         /* action is not inserted in any list: it's safe to init hitimer
 449          * without taking tcf_lock.
 450          */
 451         if (ret == ACT_P_CREATED)
 452                 gate_setup_timer(gact, gact->param.tcfg_basetime,
 453                                  gact->tk_offset, gact->param.tcfg_clockid,
 454                                  true);
 455         tcf_idr_release(*a, bind);
 456         return err;
 457 }
 458
 459 static void tcf_gate_cleanup(struct tc_action *a)
 460 {
 461         struct tcf_gate *gact = to_gate(a);
 462         struct tcf_gate_params *p;
 463
 464         p = &gact->param;
 465         hrtimer_cancel(&gact->hitimer);
 466         release_entry_list(&p->entries);
 467 }
 468
 469 static int dumping_entry(struct sk_buff *skb,
 470                          struct tcfg_gate_entry *entry)
 471 {
 472         struct nlattr *item;
 473
 474         item = nla_nest_start_noflag(skb, TCA_GATE_ONE_ENTRY);
 475         if (!item)
 476                 return -ENOSPC;
 477
 478         if (nla_put_u32(skb, TCA_GATE_ENTRY_INDEX, entry->index))
 479                 goto nla_put_failure;
 480
 481         if (entry->gate_state && nla_put_flag(skb, TCA_GATE_ENTRY_GATE))
 482                 goto nla_put_failure;
 483
 484         if (nla_put_u32(skb, TCA_GATE_ENTRY_INTERVAL, entry->interval))
 485                 goto nla_put_failure;
 486
 487         if (nla_put_s32(skb, TCA_GATE_ENTRY_MAX_OCTETS, entry->maxoctets))
 488                 goto nla_put_failure;
 489
 490         if (nla_put_s32(skb, TCA_GATE_ENTRY_IPV, entry->ipv))
 491                 goto nla_put_failure;
 492
 493         return nla_nest_end(skb, item);
 494
 495 nla_put_failure:
 496         nla_nest_cancel(skb, item);
 497         return -1;
 498 }
 499
 500 static int tcf_gate_dump(struct sk_buff *skb, struct tc_action *a,
 501                          int bind, int ref)
 502 {
 503         unsigned char *b = skb_tail_pointer(skb);
 504         struct tcf_gate *gact = to_gate(a);
 505         struct tc_gate opt = {
 506                 .index    = gact->tcf_index,
 507                 .refcnt   = refcount_read(&gact->tcf_refcnt) - ref,
 508                 .bindcnt  = atomic_read(&gact->tcf_bindcnt) - bind,
 509         };
 510         struct tcfg_gate_entry *entry;
 511         struct tcf_gate_params *p;
 512         struct nlattr *entry_list;
 513         struct tcf_t t;
 514
 515         spin_lock_bh(&gact->tcf_lock);
 516         opt.action = gact->tcf_action;
 517
 518         p = &gact->param;
 519
 520         if (nla_put(skb, TCA_GATE_PARMS, sizeof(opt), &opt))
 521                 goto nla_put_failure;
 522
 523         if (nla_put_u64_64bit(skb, TCA_GATE_BASE_TIME,
 524                               p->tcfg_basetime, TCA_GATE_PAD))
 525                 goto nla_put_failure;
 526
 527         if (nla_put_u64_64bit(skb, TCA_GATE_CYCLE_TIME,
 528                               p->tcfg_cycletime, TCA_GATE_PAD))
 529                 goto nla_put_failure;
 530
 531         if (nla_put_u64_64bit(skb, TCA_GATE_CYCLE_TIME_EXT,
 532                               p->tcfg_cycletime_ext, TCA_GATE_PAD))
 533                 goto nla_put_failure;
 534
 535         if (nla_put_s32(skb, TCA_GATE_CLOCKID, p->tcfg_clockid))
 536                 goto nla_put_failure;
 537
 538         if (nla_put_u32(skb, TCA_GATE_FLAGS, p->tcfg_flags))
 539                 goto nla_put_failure;
 540
 541         if (nla_put_s32(skb, TCA_GATE_PRIORITY, p->tcfg_priority))
 542                 goto nla_put_failure;
 543
 544         entry_list = nla_nest_start_noflag(skb, TCA_GATE_ENTRY_LIST);
 545         if (!entry_list)
 546                 goto nla_put_failure;
 547
 548         list_for_each_entry(entry, &p->entries, list) {
 549                 if (dumping_entry(skb, entry) < 0)
 550                         goto nla_put_failure;
 551         }
 552
 553         nla_nest_end(skb, entry_list);
 554
 555         tcf_tm_dump(&t, &gact->tcf_tm);
 556         if (nla_put_64bit(skb, TCA_GATE_TM, sizeof(t), &t, TCA_GATE_PAD))
 557                 goto nla_put_failure;
 558         spin_unlock_bh(&gact->tcf_lock);
 559
 560         return skb->len;
 561
 562 nla_put_failure:
 563         spin_unlock_bh(&gact->tcf_lock);
 564         nlmsg_trim(skb, b);
 565         return -1;
 566 }
 567
 568 static int tcf_gate_walker(struct net *net, struct sk_buff *skb,
 569                            struct netlink_callback *cb, int type,
 570                            const struct tc_action_ops *ops,
 571                            struct netlink_ext_ack *extack)
 572 {
 573         struct tc_action_net *tn = net_generic(net, gate_net_id);
 574
 575         return tcf_generic_walker(tn, skb, cb, type, ops, extack);
 576 }
 577
 578 static void tcf_gate_stats_update(struct tc_action *a, u64 bytes, u64 packets,
 579                                   u64 drops, u64 lastuse, bool hw)
 580 {
 581         struct tcf_gate *gact = to_gate(a);
 582         struct tcf_t *tm = &gact->tcf_tm;
 583
 584         tcf_action_update_stats(a, bytes, packets, drops, hw);
 585         tm->lastuse = max_t(u64, tm->lastuse, lastuse);
 586 }
 587
 588 static int tcf_gate_search(struct net *net, struct tc_action **a, u32 index)
 589 {
 590         struct tc_action_net *tn = net_generic(net, gate_net_id);
 591
 592         return tcf_idr_search(tn, a, index);
 593 }
 594
 595 static size_t tcf_gate_get_fill_size(const struct tc_action *act)
 596 {
 597         return nla_total_size(sizeof(struct tc_gate));
 598 }
 599
 600 static struct tc_action_ops act_gate_ops = {
 601         .kind           =       "gate",
 602         .id             =       TCA_ID_GATE,
 603         .owner          =       THIS_MODULE,
 604         .act            =       tcf_gate_act,
 605         .dump           =       tcf_gate_dump,
 606         .init           =       tcf_gate_init,
 607         .cleanup        =       tcf_gate_cleanup,
 608         .walk           =       tcf_gate_walker,
 609         .stats_update   =       tcf_gate_stats_update,
 610         .get_fill_size  =       tcf_gate_get_fill_size,
 611         .lookup         =       tcf_gate_search,
 612         .size           =       sizeof(struct tcf_gate),
 613 };
 614
 615 static __net_init int gate_init_net(struct net *net)
 616 {
 617         struct tc_action_net *tn = net_generic(net, gate_net_id);
 618
 619         return tc_action_net_init(net, tn, &act_gate_ops);
 620 }
 621
 622 static void __net_exit gate_exit_net(struct list_head *net_list)
 623 {
 624         tc_action_net_exit(net_list, gate_net_id);
 625 }
 626
 627 static struct pernet_operations gate_net_ops = {
 628         .init = gate_init_net,
 629         .exit_batch = gate_exit_net,
 630         .id   = &gate_net_id,
 631         .size = sizeof(struct tc_action_net),
 632 };
 633
 634 static int __init gate_init_module(void)
 635 {
 636         return tcf_register_action(&act_gate_ops, &gate_net_ops);
 637 }
 638
 639 static void __exit gate_cleanup_module(void)
 640 {
 641         tcf_unregister_action(&act_gate_ops, &gate_net_ops);
 642 }
 643
 644 module_init(gate_init_module);
 645 module_exit(gate_cleanup_module);
 646 MODULE_LICENSE("GPL v2");