linux/net/sched/act_api.c
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   1/*
   2 * net/sched/act_api.c  Packet action API.
   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 * Author:      Jamal Hadi Salim
  10 *
  11 *
  12 */
  13
  14#include <linux/types.h>
  15#include <linux/kernel.h>
  16#include <linux/string.h>
  17#include <linux/errno.h>
  18#include <linux/slab.h>
  19#include <linux/skbuff.h>
  20#include <linux/init.h>
  21#include <linux/kmod.h>
  22#include <linux/err.h>
  23#include <linux/module.h>
  24#include <net/net_namespace.h>
  25#include <net/sock.h>
  26#include <net/sch_generic.h>
  27#include <net/act_api.h>
  28#include <net/netlink.h>
  29
  30void tcf_hash_destroy(struct tcf_common *p, struct tcf_hashinfo *hinfo)
  31{
  32        unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
  33        struct tcf_common **p1p;
  34
  35        for (p1p = &hinfo->htab[h]; *p1p; p1p = &(*p1p)->tcfc_next) {
  36                if (*p1p == p) {
  37                        write_lock_bh(hinfo->lock);
  38                        *p1p = p->tcfc_next;
  39                        write_unlock_bh(hinfo->lock);
  40                        gen_kill_estimator(&p->tcfc_bstats,
  41                                           &p->tcfc_rate_est);
  42                        /*
  43                         * gen_estimator est_timer() might access p->tcfc_lock
  44                         * or bstats, wait a RCU grace period before freeing p
  45                         */
  46                        kfree_rcu(p, tcfc_rcu);
  47                        return;
  48                }
  49        }
  50        WARN_ON(1);
  51}
  52EXPORT_SYMBOL(tcf_hash_destroy);
  53
  54int tcf_hash_release(struct tcf_common *p, int bind,
  55                     struct tcf_hashinfo *hinfo)
  56{
  57        int ret = 0;
  58
  59        if (p) {
  60                if (bind)
  61                        p->tcfc_bindcnt--;
  62
  63                p->tcfc_refcnt--;
  64                if (p->tcfc_bindcnt <= 0 && p->tcfc_refcnt <= 0) {
  65                        tcf_hash_destroy(p, hinfo);
  66                        ret = 1;
  67                }
  68        }
  69        return ret;
  70}
  71EXPORT_SYMBOL(tcf_hash_release);
  72
  73static int tcf_dump_walker(struct sk_buff *skb, struct netlink_callback *cb,
  74                           struct tc_action *a, struct tcf_hashinfo *hinfo)
  75{
  76        struct tcf_common *p;
  77        int err = 0, index = -1, i = 0, s_i = 0, n_i = 0;
  78        struct nlattr *nest;
  79
  80        read_lock_bh(hinfo->lock);
  81
  82        s_i = cb->args[0];
  83
  84        for (i = 0; i < (hinfo->hmask + 1); i++) {
  85                p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
  86
  87                for (; p; p = p->tcfc_next) {
  88                        index++;
  89                        if (index < s_i)
  90                                continue;
  91                        a->priv = p;
  92                        a->order = n_i;
  93
  94                        nest = nla_nest_start(skb, a->order);
  95                        if (nest == NULL)
  96                                goto nla_put_failure;
  97                        err = tcf_action_dump_1(skb, a, 0, 0);
  98                        if (err < 0) {
  99                                index--;
 100                                nlmsg_trim(skb, nest);
 101                                goto done;
 102                        }
 103                        nla_nest_end(skb, nest);
 104                        n_i++;
 105                        if (n_i >= TCA_ACT_MAX_PRIO)
 106                                goto done;
 107                }
 108        }
 109done:
 110        read_unlock_bh(hinfo->lock);
 111        if (n_i)
 112                cb->args[0] += n_i;
 113        return n_i;
 114
 115nla_put_failure:
 116        nla_nest_cancel(skb, nest);
 117        goto done;
 118}
 119
 120static int tcf_del_walker(struct sk_buff *skb, struct tc_action *a,
 121                          struct tcf_hashinfo *hinfo)
 122{
 123        struct tcf_common *p, *s_p;
 124        struct nlattr *nest;
 125        int i = 0, n_i = 0;
 126
 127        nest = nla_nest_start(skb, a->order);
 128        if (nest == NULL)
 129                goto nla_put_failure;
 130        if (nla_put_string(skb, TCA_KIND, a->ops->kind))
 131                goto nla_put_failure;
 132        for (i = 0; i < (hinfo->hmask + 1); i++) {
 133                p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
 134
 135                while (p != NULL) {
 136                        s_p = p->tcfc_next;
 137                        if (ACT_P_DELETED == tcf_hash_release(p, 0, hinfo))
 138                                module_put(a->ops->owner);
 139                        n_i++;
 140                        p = s_p;
 141                }
 142        }
 143        if (nla_put_u32(skb, TCA_FCNT, n_i))
 144                goto nla_put_failure;
 145        nla_nest_end(skb, nest);
 146
 147        return n_i;
 148nla_put_failure:
 149        nla_nest_cancel(skb, nest);
 150        return -EINVAL;
 151}
 152
 153int tcf_generic_walker(struct sk_buff *skb, struct netlink_callback *cb,
 154                       int type, struct tc_action *a)
 155{
 156        struct tcf_hashinfo *hinfo = a->ops->hinfo;
 157
 158        if (type == RTM_DELACTION) {
 159                return tcf_del_walker(skb, a, hinfo);
 160        } else if (type == RTM_GETACTION) {
 161                return tcf_dump_walker(skb, cb, a, hinfo);
 162        } else {
 163                WARN(1, "tcf_generic_walker: unknown action %d\n", type);
 164                return -EINVAL;
 165        }
 166}
 167EXPORT_SYMBOL(tcf_generic_walker);
 168
 169struct tcf_common *tcf_hash_lookup(u32 index, struct tcf_hashinfo *hinfo)
 170{
 171        struct tcf_common *p;
 172
 173        read_lock_bh(hinfo->lock);
 174        for (p = hinfo->htab[tcf_hash(index, hinfo->hmask)]; p;
 175             p = p->tcfc_next) {
 176                if (p->tcfc_index == index)
 177                        break;
 178        }
 179        read_unlock_bh(hinfo->lock);
 180
 181        return p;
 182}
 183EXPORT_SYMBOL(tcf_hash_lookup);
 184
 185u32 tcf_hash_new_index(u32 *idx_gen, struct tcf_hashinfo *hinfo)
 186{
 187        u32 val = *idx_gen;
 188
 189        do {
 190                if (++val == 0)
 191                        val = 1;
 192        } while (tcf_hash_lookup(val, hinfo));
 193
 194        return (*idx_gen = val);
 195}
 196EXPORT_SYMBOL(tcf_hash_new_index);
 197
 198int tcf_hash_search(struct tc_action *a, u32 index)
 199{
 200        struct tcf_hashinfo *hinfo = a->ops->hinfo;
 201        struct tcf_common *p = tcf_hash_lookup(index, hinfo);
 202
 203        if (p) {
 204                a->priv = p;
 205                return 1;
 206        }
 207        return 0;
 208}
 209EXPORT_SYMBOL(tcf_hash_search);
 210
 211struct tcf_common *tcf_hash_check(u32 index, struct tc_action *a, int bind,
 212                                  struct tcf_hashinfo *hinfo)
 213{
 214        struct tcf_common *p = NULL;
 215        if (index && (p = tcf_hash_lookup(index, hinfo)) != NULL) {
 216                if (bind)
 217                        p->tcfc_bindcnt++;
 218                p->tcfc_refcnt++;
 219                a->priv = p;
 220        }
 221        return p;
 222}
 223EXPORT_SYMBOL(tcf_hash_check);
 224
 225struct tcf_common *tcf_hash_create(u32 index, struct nlattr *est,
 226                                   struct tc_action *a, int size, int bind,
 227                                   u32 *idx_gen, struct tcf_hashinfo *hinfo)
 228{
 229        struct tcf_common *p = kzalloc(size, GFP_KERNEL);
 230
 231        if (unlikely(!p))
 232                return ERR_PTR(-ENOMEM);
 233        p->tcfc_refcnt = 1;
 234        if (bind)
 235                p->tcfc_bindcnt = 1;
 236
 237        spin_lock_init(&p->tcfc_lock);
 238        p->tcfc_index = index ? index : tcf_hash_new_index(idx_gen, hinfo);
 239        p->tcfc_tm.install = jiffies;
 240        p->tcfc_tm.lastuse = jiffies;
 241        if (est) {
 242                int err = gen_new_estimator(&p->tcfc_bstats, &p->tcfc_rate_est,
 243                                            &p->tcfc_lock, est);
 244                if (err) {
 245                        kfree(p);
 246                        return ERR_PTR(err);
 247                }
 248        }
 249
 250        a->priv = (void *) p;
 251        return p;
 252}
 253EXPORT_SYMBOL(tcf_hash_create);
 254
 255void tcf_hash_insert(struct tcf_common *p, struct tcf_hashinfo *hinfo)
 256{
 257        unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
 258
 259        write_lock_bh(hinfo->lock);
 260        p->tcfc_next = hinfo->htab[h];
 261        hinfo->htab[h] = p;
 262        write_unlock_bh(hinfo->lock);
 263}
 264EXPORT_SYMBOL(tcf_hash_insert);
 265
 266static struct tc_action_ops *act_base = NULL;
 267static DEFINE_RWLOCK(act_mod_lock);
 268
 269int tcf_register_action(struct tc_action_ops *act)
 270{
 271        struct tc_action_ops *a, **ap;
 272
 273        write_lock(&act_mod_lock);
 274        for (ap = &act_base; (a = *ap) != NULL; ap = &a->next) {
 275                if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
 276                        write_unlock(&act_mod_lock);
 277                        return -EEXIST;
 278                }
 279        }
 280        act->next = NULL;
 281        *ap = act;
 282        write_unlock(&act_mod_lock);
 283        return 0;
 284}
 285EXPORT_SYMBOL(tcf_register_action);
 286
 287int tcf_unregister_action(struct tc_action_ops *act)
 288{
 289        struct tc_action_ops *a, **ap;
 290        int err = -ENOENT;
 291
 292        write_lock(&act_mod_lock);
 293        for (ap = &act_base; (a = *ap) != NULL; ap = &a->next)
 294                if (a == act)
 295                        break;
 296        if (a) {
 297                *ap = a->next;
 298                a->next = NULL;
 299                err = 0;
 300        }
 301        write_unlock(&act_mod_lock);
 302        return err;
 303}
 304EXPORT_SYMBOL(tcf_unregister_action);
 305
 306/* lookup by name */
 307static struct tc_action_ops *tc_lookup_action_n(char *kind)
 308{
 309        struct tc_action_ops *a = NULL;
 310
 311        if (kind) {
 312                read_lock(&act_mod_lock);
 313                for (a = act_base; a; a = a->next) {
 314                        if (strcmp(kind, a->kind) == 0) {
 315                                if (!try_module_get(a->owner)) {
 316                                        read_unlock(&act_mod_lock);
 317                                        return NULL;
 318                                }
 319                                break;
 320                        }
 321                }
 322                read_unlock(&act_mod_lock);
 323        }
 324        return a;
 325}
 326
 327/* lookup by nlattr */
 328static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
 329{
 330        struct tc_action_ops *a = NULL;
 331
 332        if (kind) {
 333                read_lock(&act_mod_lock);
 334                for (a = act_base; a; a = a->next) {
 335                        if (nla_strcmp(kind, a->kind) == 0) {
 336                                if (!try_module_get(a->owner)) {
 337                                        read_unlock(&act_mod_lock);
 338                                        return NULL;
 339                                }
 340                                break;
 341                        }
 342                }
 343                read_unlock(&act_mod_lock);
 344        }
 345        return a;
 346}
 347
 348#if 0
 349/* lookup by id */
 350static struct tc_action_ops *tc_lookup_action_id(u32 type)
 351{
 352        struct tc_action_ops *a = NULL;
 353
 354        if (type) {
 355                read_lock(&act_mod_lock);
 356                for (a = act_base; a; a = a->next) {
 357                        if (a->type == type) {
 358                                if (!try_module_get(a->owner)) {
 359                                        read_unlock(&act_mod_lock);
 360                                        return NULL;
 361                                }
 362                                break;
 363                        }
 364                }
 365                read_unlock(&act_mod_lock);
 366        }
 367        return a;
 368}
 369#endif
 370
 371int tcf_action_exec(struct sk_buff *skb, const struct tc_action *act,
 372                    struct tcf_result *res)
 373{
 374        const struct tc_action *a;
 375        int ret = -1;
 376
 377        if (skb->tc_verd & TC_NCLS) {
 378                skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
 379                ret = TC_ACT_OK;
 380                goto exec_done;
 381        }
 382        while ((a = act) != NULL) {
 383repeat:
 384                if (a->ops && a->ops->act) {
 385                        ret = a->ops->act(skb, a, res);
 386                        if (TC_MUNGED & skb->tc_verd) {
 387                                /* copied already, allow trampling */
 388                                skb->tc_verd = SET_TC_OK2MUNGE(skb->tc_verd);
 389                                skb->tc_verd = CLR_TC_MUNGED(skb->tc_verd);
 390                        }
 391                        if (ret == TC_ACT_REPEAT)
 392                                goto repeat;    /* we need a ttl - JHS */
 393                        if (ret != TC_ACT_PIPE)
 394                                goto exec_done;
 395                }
 396                act = a->next;
 397        }
 398exec_done:
 399        return ret;
 400}
 401EXPORT_SYMBOL(tcf_action_exec);
 402
 403void tcf_action_destroy(struct tc_action *act, int bind)
 404{
 405        struct tc_action *a;
 406
 407        for (a = act; a; a = act) {
 408                if (a->ops && a->ops->cleanup) {
 409                        if (a->ops->cleanup(a, bind) == ACT_P_DELETED)
 410                                module_put(a->ops->owner);
 411                        act = act->next;
 412                        kfree(a);
 413                } else {
 414                        /*FIXME: Remove later - catch insertion bugs*/
 415                        WARN(1, "tcf_action_destroy: BUG? destroying NULL ops\n");
 416                        act = act->next;
 417                        kfree(a);
 418                }
 419        }
 420}
 421
 422int
 423tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 424{
 425        int err = -EINVAL;
 426
 427        if (a->ops == NULL || a->ops->dump == NULL)
 428                return err;
 429        return a->ops->dump(skb, a, bind, ref);
 430}
 431
 432int
 433tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 434{
 435        int err = -EINVAL;
 436        unsigned char *b = skb_tail_pointer(skb);
 437        struct nlattr *nest;
 438
 439        if (a->ops == NULL || a->ops->dump == NULL)
 440                return err;
 441
 442        if (nla_put_string(skb, TCA_KIND, a->ops->kind))
 443                goto nla_put_failure;
 444        if (tcf_action_copy_stats(skb, a, 0))
 445                goto nla_put_failure;
 446        nest = nla_nest_start(skb, TCA_OPTIONS);
 447        if (nest == NULL)
 448                goto nla_put_failure;
 449        err = tcf_action_dump_old(skb, a, bind, ref);
 450        if (err > 0) {
 451                nla_nest_end(skb, nest);
 452                return err;
 453        }
 454
 455nla_put_failure:
 456        nlmsg_trim(skb, b);
 457        return -1;
 458}
 459EXPORT_SYMBOL(tcf_action_dump_1);
 460
 461int
 462tcf_action_dump(struct sk_buff *skb, struct tc_action *act, int bind, int ref)
 463{
 464        struct tc_action *a;
 465        int err = -EINVAL;
 466        struct nlattr *nest;
 467
 468        while ((a = act) != NULL) {
 469                act = a->next;
 470                nest = nla_nest_start(skb, a->order);
 471                if (nest == NULL)
 472                        goto nla_put_failure;
 473                err = tcf_action_dump_1(skb, a, bind, ref);
 474                if (err < 0)
 475                        goto errout;
 476                nla_nest_end(skb, nest);
 477        }
 478
 479        return 0;
 480
 481nla_put_failure:
 482        err = -EINVAL;
 483errout:
 484        nla_nest_cancel(skb, nest);
 485        return err;
 486}
 487
 488struct tc_action *tcf_action_init_1(struct nlattr *nla, struct nlattr *est,
 489                                    char *name, int ovr, int bind)
 490{
 491        struct tc_action *a;
 492        struct tc_action_ops *a_o;
 493        char act_name[IFNAMSIZ];
 494        struct nlattr *tb[TCA_ACT_MAX + 1];
 495        struct nlattr *kind;
 496        int err;
 497
 498        if (name == NULL) {
 499                err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 500                if (err < 0)
 501                        goto err_out;
 502                err = -EINVAL;
 503                kind = tb[TCA_ACT_KIND];
 504                if (kind == NULL)
 505                        goto err_out;
 506                if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
 507                        goto err_out;
 508        } else {
 509                err = -EINVAL;
 510                if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
 511                        goto err_out;
 512        }
 513
 514        a_o = tc_lookup_action_n(act_name);
 515        if (a_o == NULL) {
 516#ifdef CONFIG_MODULES
 517                rtnl_unlock();
 518                request_module("act_%s", act_name);
 519                rtnl_lock();
 520
 521                a_o = tc_lookup_action_n(act_name);
 522
 523                /* We dropped the RTNL semaphore in order to
 524                 * perform the module load.  So, even if we
 525                 * succeeded in loading the module we have to
 526                 * tell the caller to replay the request.  We
 527                 * indicate this using -EAGAIN.
 528                 */
 529                if (a_o != NULL) {
 530                        err = -EAGAIN;
 531                        goto err_mod;
 532                }
 533#endif
 534                err = -ENOENT;
 535                goto err_out;
 536        }
 537
 538        err = -ENOMEM;
 539        a = kzalloc(sizeof(*a), GFP_KERNEL);
 540        if (a == NULL)
 541                goto err_mod;
 542
 543        /* backward compatibility for policer */
 544        if (name == NULL)
 545                err = a_o->init(tb[TCA_ACT_OPTIONS], est, a, ovr, bind);
 546        else
 547                err = a_o->init(nla, est, a, ovr, bind);
 548        if (err < 0)
 549                goto err_free;
 550
 551        /* module count goes up only when brand new policy is created
 552         * if it exists and is only bound to in a_o->init() then
 553         * ACT_P_CREATED is not returned (a zero is).
 554         */
 555        if (err != ACT_P_CREATED)
 556                module_put(a_o->owner);
 557        a->ops = a_o;
 558
 559        return a;
 560
 561err_free:
 562        kfree(a);
 563err_mod:
 564        module_put(a_o->owner);
 565err_out:
 566        return ERR_PTR(err);
 567}
 568
 569struct tc_action *tcf_action_init(struct nlattr *nla, struct nlattr *est,
 570                                  char *name, int ovr, int bind)
 571{
 572        struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 573        struct tc_action *head = NULL, *act, *act_prev = NULL;
 574        int err;
 575        int i;
 576
 577        err = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 578        if (err < 0)
 579                return ERR_PTR(err);
 580
 581        for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 582                act = tcf_action_init_1(tb[i], est, name, ovr, bind);
 583                if (IS_ERR(act))
 584                        goto err;
 585                act->order = i;
 586
 587                if (head == NULL)
 588                        head = act;
 589                else
 590                        act_prev->next = act;
 591                act_prev = act;
 592        }
 593        return head;
 594
 595err:
 596        if (head != NULL)
 597                tcf_action_destroy(head, bind);
 598        return act;
 599}
 600
 601int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
 602                          int compat_mode)
 603{
 604        int err = 0;
 605        struct gnet_dump d;
 606        struct tcf_act_hdr *h = a->priv;
 607
 608        if (h == NULL)
 609                goto errout;
 610
 611        /* compat_mode being true specifies a call that is supposed
 612         * to add additional backward compatibility statistic TLVs.
 613         */
 614        if (compat_mode) {
 615                if (a->type == TCA_OLD_COMPAT)
 616                        err = gnet_stats_start_copy_compat(skb, 0,
 617                                TCA_STATS, TCA_XSTATS, &h->tcf_lock, &d);
 618                else
 619                        return 0;
 620        } else
 621                err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
 622                                            &h->tcf_lock, &d);
 623
 624        if (err < 0)
 625                goto errout;
 626
 627        if (a->ops != NULL && a->ops->get_stats != NULL)
 628                if (a->ops->get_stats(skb, a) < 0)
 629                        goto errout;
 630
 631        if (gnet_stats_copy_basic(&d, &h->tcf_bstats) < 0 ||
 632            gnet_stats_copy_rate_est(&d, &h->tcf_bstats,
 633                                     &h->tcf_rate_est) < 0 ||
 634            gnet_stats_copy_queue(&d, &h->tcf_qstats) < 0)
 635                goto errout;
 636
 637        if (gnet_stats_finish_copy(&d) < 0)
 638                goto errout;
 639
 640        return 0;
 641
 642errout:
 643        return -1;
 644}
 645
 646static int
 647tca_get_fill(struct sk_buff *skb, struct tc_action *a, u32 pid, u32 seq,
 648             u16 flags, int event, int bind, int ref)
 649{
 650        struct tcamsg *t;
 651        struct nlmsghdr *nlh;
 652        unsigned char *b = skb_tail_pointer(skb);
 653        struct nlattr *nest;
 654
 655        nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
 656
 657        t = NLMSG_DATA(nlh);
 658        t->tca_family = AF_UNSPEC;
 659        t->tca__pad1 = 0;
 660        t->tca__pad2 = 0;
 661
 662        nest = nla_nest_start(skb, TCA_ACT_TAB);
 663        if (nest == NULL)
 664                goto nla_put_failure;
 665
 666        if (tcf_action_dump(skb, a, bind, ref) < 0)
 667                goto nla_put_failure;
 668
 669        nla_nest_end(skb, nest);
 670
 671        nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 672        return skb->len;
 673
 674nla_put_failure:
 675nlmsg_failure:
 676        nlmsg_trim(skb, b);
 677        return -1;
 678}
 679
 680static int
 681act_get_notify(struct net *net, u32 pid, struct nlmsghdr *n,
 682               struct tc_action *a, int event)
 683{
 684        struct sk_buff *skb;
 685
 686        skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 687        if (!skb)
 688                return -ENOBUFS;
 689        if (tca_get_fill(skb, a, pid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
 690                kfree_skb(skb);
 691                return -EINVAL;
 692        }
 693
 694        return rtnl_unicast(skb, net, pid);
 695}
 696
 697static struct tc_action *
 698tcf_action_get_1(struct nlattr *nla, struct nlmsghdr *n, u32 pid)
 699{
 700        struct nlattr *tb[TCA_ACT_MAX + 1];
 701        struct tc_action *a;
 702        int index;
 703        int err;
 704
 705        err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 706        if (err < 0)
 707                goto err_out;
 708
 709        err = -EINVAL;
 710        if (tb[TCA_ACT_INDEX] == NULL ||
 711            nla_len(tb[TCA_ACT_INDEX]) < sizeof(index))
 712                goto err_out;
 713        index = nla_get_u32(tb[TCA_ACT_INDEX]);
 714
 715        err = -ENOMEM;
 716        a = kzalloc(sizeof(struct tc_action), GFP_KERNEL);
 717        if (a == NULL)
 718                goto err_out;
 719
 720        err = -EINVAL;
 721        a->ops = tc_lookup_action(tb[TCA_ACT_KIND]);
 722        if (a->ops == NULL)
 723                goto err_free;
 724        if (a->ops->lookup == NULL)
 725                goto err_mod;
 726        err = -ENOENT;
 727        if (a->ops->lookup(a, index) == 0)
 728                goto err_mod;
 729
 730        module_put(a->ops->owner);
 731        return a;
 732
 733err_mod:
 734        module_put(a->ops->owner);
 735err_free:
 736        kfree(a);
 737err_out:
 738        return ERR_PTR(err);
 739}
 740
 741static void cleanup_a(struct tc_action *act)
 742{
 743        struct tc_action *a;
 744
 745        for (a = act; a; a = act) {
 746                act = a->next;
 747                kfree(a);
 748        }
 749}
 750
 751static struct tc_action *create_a(int i)
 752{
 753        struct tc_action *act;
 754
 755        act = kzalloc(sizeof(*act), GFP_KERNEL);
 756        if (act == NULL) {
 757                pr_debug("create_a: failed to alloc!\n");
 758                return NULL;
 759        }
 760        act->order = i;
 761        return act;
 762}
 763
 764static int tca_action_flush(struct net *net, struct nlattr *nla,
 765                            struct nlmsghdr *n, u32 pid)
 766{
 767        struct sk_buff *skb;
 768        unsigned char *b;
 769        struct nlmsghdr *nlh;
 770        struct tcamsg *t;
 771        struct netlink_callback dcb;
 772        struct nlattr *nest;
 773        struct nlattr *tb[TCA_ACT_MAX + 1];
 774        struct nlattr *kind;
 775        struct tc_action *a = create_a(0);
 776        int err = -ENOMEM;
 777
 778        if (a == NULL) {
 779                pr_debug("tca_action_flush: couldnt create tc_action\n");
 780                return err;
 781        }
 782
 783        skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 784        if (!skb) {
 785                pr_debug("tca_action_flush: failed skb alloc\n");
 786                kfree(a);
 787                return err;
 788        }
 789
 790        b = skb_tail_pointer(skb);
 791
 792        err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
 793        if (err < 0)
 794                goto err_out;
 795
 796        err = -EINVAL;
 797        kind = tb[TCA_ACT_KIND];
 798        a->ops = tc_lookup_action(kind);
 799        if (a->ops == NULL)
 800                goto err_out;
 801
 802        nlh = NLMSG_PUT(skb, pid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t));
 803        t = NLMSG_DATA(nlh);
 804        t->tca_family = AF_UNSPEC;
 805        t->tca__pad1 = 0;
 806        t->tca__pad2 = 0;
 807
 808        nest = nla_nest_start(skb, TCA_ACT_TAB);
 809        if (nest == NULL)
 810                goto nla_put_failure;
 811
 812        err = a->ops->walk(skb, &dcb, RTM_DELACTION, a);
 813        if (err < 0)
 814                goto nla_put_failure;
 815        if (err == 0)
 816                goto noflush_out;
 817
 818        nla_nest_end(skb, nest);
 819
 820        nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 821        nlh->nlmsg_flags |= NLM_F_ROOT;
 822        module_put(a->ops->owner);
 823        kfree(a);
 824        err = rtnetlink_send(skb, net, pid, RTNLGRP_TC,
 825                             n->nlmsg_flags & NLM_F_ECHO);
 826        if (err > 0)
 827                return 0;
 828
 829        return err;
 830
 831nla_put_failure:
 832nlmsg_failure:
 833        module_put(a->ops->owner);
 834err_out:
 835noflush_out:
 836        kfree_skb(skb);
 837        kfree(a);
 838        return err;
 839}
 840
 841static int
 842tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 843              u32 pid, int event)
 844{
 845        int i, ret;
 846        struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 847        struct tc_action *head = NULL, *act, *act_prev = NULL;
 848
 849        ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 850        if (ret < 0)
 851                return ret;
 852
 853        if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
 854                if (tb[1] != NULL)
 855                        return tca_action_flush(net, tb[1], n, pid);
 856                else
 857                        return -EINVAL;
 858        }
 859
 860        for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 861                act = tcf_action_get_1(tb[i], n, pid);
 862                if (IS_ERR(act)) {
 863                        ret = PTR_ERR(act);
 864                        goto err;
 865                }
 866                act->order = i;
 867
 868                if (head == NULL)
 869                        head = act;
 870                else
 871                        act_prev->next = act;
 872                act_prev = act;
 873        }
 874
 875        if (event == RTM_GETACTION)
 876                ret = act_get_notify(net, pid, n, head, event);
 877        else { /* delete */
 878                struct sk_buff *skb;
 879
 880                skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 881                if (!skb) {
 882                        ret = -ENOBUFS;
 883                        goto err;
 884                }
 885
 886                if (tca_get_fill(skb, head, pid, n->nlmsg_seq, 0, event,
 887                                 0, 1) <= 0) {
 888                        kfree_skb(skb);
 889                        ret = -EINVAL;
 890                        goto err;
 891                }
 892
 893                /* now do the delete */
 894                tcf_action_destroy(head, 0);
 895                ret = rtnetlink_send(skb, net, pid, RTNLGRP_TC,
 896                                     n->nlmsg_flags & NLM_F_ECHO);
 897                if (ret > 0)
 898                        return 0;
 899                return ret;
 900        }
 901err:
 902        cleanup_a(head);
 903        return ret;
 904}
 905
 906static int tcf_add_notify(struct net *net, struct tc_action *a,
 907                          u32 pid, u32 seq, int event, u16 flags)
 908{
 909        struct tcamsg *t;
 910        struct nlmsghdr *nlh;
 911        struct sk_buff *skb;
 912        struct nlattr *nest;
 913        unsigned char *b;
 914        int err = 0;
 915
 916        skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 917        if (!skb)
 918                return -ENOBUFS;
 919
 920        b = skb_tail_pointer(skb);
 921
 922        nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
 923        t = NLMSG_DATA(nlh);
 924        t->tca_family = AF_UNSPEC;
 925        t->tca__pad1 = 0;
 926        t->tca__pad2 = 0;
 927
 928        nest = nla_nest_start(skb, TCA_ACT_TAB);
 929        if (nest == NULL)
 930                goto nla_put_failure;
 931
 932        if (tcf_action_dump(skb, a, 0, 0) < 0)
 933                goto nla_put_failure;
 934
 935        nla_nest_end(skb, nest);
 936
 937        nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 938        NETLINK_CB(skb).dst_group = RTNLGRP_TC;
 939
 940        err = rtnetlink_send(skb, net, pid, RTNLGRP_TC, flags & NLM_F_ECHO);
 941        if (err > 0)
 942                err = 0;
 943        return err;
 944
 945nla_put_failure:
 946nlmsg_failure:
 947        kfree_skb(skb);
 948        return -1;
 949}
 950
 951
 952static int
 953tcf_action_add(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 954               u32 pid, int ovr)
 955{
 956        int ret = 0;
 957        struct tc_action *act;
 958        struct tc_action *a;
 959        u32 seq = n->nlmsg_seq;
 960
 961        act = tcf_action_init(nla, NULL, NULL, ovr, 0);
 962        if (act == NULL)
 963                goto done;
 964        if (IS_ERR(act)) {
 965                ret = PTR_ERR(act);
 966                goto done;
 967        }
 968
 969        /* dump then free all the actions after update; inserted policy
 970         * stays intact
 971         */
 972        ret = tcf_add_notify(net, act, pid, seq, RTM_NEWACTION, n->nlmsg_flags);
 973        for (a = act; a; a = act) {
 974                act = a->next;
 975                kfree(a);
 976        }
 977done:
 978        return ret;
 979}
 980
 981static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
 982{
 983        struct net *net = sock_net(skb->sk);
 984        struct nlattr *tca[TCA_ACT_MAX + 1];
 985        u32 pid = skb ? NETLINK_CB(skb).pid : 0;
 986        int ret = 0, ovr = 0;
 987
 988        ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ACT_MAX, NULL);
 989        if (ret < 0)
 990                return ret;
 991
 992        if (tca[TCA_ACT_TAB] == NULL) {
 993                pr_notice("tc_ctl_action: received NO action attribs\n");
 994                return -EINVAL;
 995        }
 996
 997        /* n->nlmsg_flags & NLM_F_CREATE */
 998        switch (n->nlmsg_type) {
 999        case RTM_NEWACTION:
1000                /* we are going to assume all other flags
1001                 * imply create only if it doesn't exist
1002                 * Note that CREATE | EXCL implies that
1003                 * but since we want avoid ambiguity (eg when flags
1004                 * is zero) then just set this
1005                 */
1006                if (n->nlmsg_flags & NLM_F_REPLACE)
1007                        ovr = 1;
1008replay:
1009                ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, pid, ovr);
1010                if (ret == -EAGAIN)
1011                        goto replay;
1012                break;
1013        case RTM_DELACTION:
1014                ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1015                                    pid, RTM_DELACTION);
1016                break;
1017        case RTM_GETACTION:
1018                ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1019                                    pid, RTM_GETACTION);
1020                break;
1021        default:
1022                BUG();
1023        }
1024
1025        return ret;
1026}
1027
1028static struct nlattr *
1029find_dump_kind(const struct nlmsghdr *n)
1030{
1031        struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
1032        struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1033        struct nlattr *nla[TCAA_MAX + 1];
1034        struct nlattr *kind;
1035
1036        if (nlmsg_parse(n, sizeof(struct tcamsg), nla, TCAA_MAX, NULL) < 0)
1037                return NULL;
1038        tb1 = nla[TCA_ACT_TAB];
1039        if (tb1 == NULL)
1040                return NULL;
1041
1042        if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
1043                      NLMSG_ALIGN(nla_len(tb1)), NULL) < 0)
1044                return NULL;
1045
1046        if (tb[1] == NULL)
1047                return NULL;
1048        if (nla_parse(tb2, TCA_ACT_MAX, nla_data(tb[1]),
1049                      nla_len(tb[1]), NULL) < 0)
1050                return NULL;
1051        kind = tb2[TCA_ACT_KIND];
1052
1053        return kind;
1054}
1055
1056static int
1057tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1058{
1059        struct nlmsghdr *nlh;
1060        unsigned char *b = skb_tail_pointer(skb);
1061        struct nlattr *nest;
1062        struct tc_action_ops *a_o;
1063        struct tc_action a;
1064        int ret = 0;
1065        struct tcamsg *t = (struct tcamsg *) NLMSG_DATA(cb->nlh);
1066        struct nlattr *kind = find_dump_kind(cb->nlh);
1067
1068        if (kind == NULL) {
1069                pr_info("tc_dump_action: action bad kind\n");
1070                return 0;
1071        }
1072
1073        a_o = tc_lookup_action(kind);
1074        if (a_o == NULL)
1075                return 0;
1076
1077        memset(&a, 0, sizeof(struct tc_action));
1078        a.ops = a_o;
1079
1080        if (a_o->walk == NULL) {
1081                WARN(1, "tc_dump_action: %s !capable of dumping table\n",
1082                     a_o->kind);
1083                goto nla_put_failure;
1084        }
1085
1086        nlh = NLMSG_PUT(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
1087                        cb->nlh->nlmsg_type, sizeof(*t));
1088        t = NLMSG_DATA(nlh);
1089        t->tca_family = AF_UNSPEC;
1090        t->tca__pad1 = 0;
1091        t->tca__pad2 = 0;
1092
1093        nest = nla_nest_start(skb, TCA_ACT_TAB);
1094        if (nest == NULL)
1095                goto nla_put_failure;
1096
1097        ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
1098        if (ret < 0)
1099                goto nla_put_failure;
1100
1101        if (ret > 0) {
1102                nla_nest_end(skb, nest);
1103                ret = skb->len;
1104        } else
1105                nla_nest_cancel(skb, nest);
1106
1107        nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1108        if (NETLINK_CB(cb->skb).pid && ret)
1109                nlh->nlmsg_flags |= NLM_F_MULTI;
1110        module_put(a_o->owner);
1111        return skb->len;
1112
1113nla_put_failure:
1114nlmsg_failure:
1115        module_put(a_o->owner);
1116        nlmsg_trim(skb, b);
1117        return skb->len;
1118}
1119
1120static int __init tc_action_init(void)
1121{
1122        rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, NULL);
1123        rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, NULL);
1124        rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
1125                      NULL);
1126
1127        return 0;
1128}
1129
1130subsys_initcall(tc_action_init);
1131