linux/net/sched/act_api.c
<<
>>
Prefs
   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_put(skb, pid, seq, event, sizeof(*t), flags);
 656        if (!nlh)
 657                goto out_nlmsg_trim;
 658        t = nlmsg_data(nlh);
 659        t->tca_family = AF_UNSPEC;
 660        t->tca__pad1 = 0;
 661        t->tca__pad2 = 0;
 662
 663        nest = nla_nest_start(skb, TCA_ACT_TAB);
 664        if (nest == NULL)
 665                goto out_nlmsg_trim;
 666
 667        if (tcf_action_dump(skb, a, bind, ref) < 0)
 668                goto out_nlmsg_trim;
 669
 670        nla_nest_end(skb, nest);
 671
 672        nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 673        return skb->len;
 674
 675out_nlmsg_trim:
 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), 0);
 803        if (!nlh)
 804                goto out_module_put;
 805        t = nlmsg_data(nlh);
 806        t->tca_family = AF_UNSPEC;
 807        t->tca__pad1 = 0;
 808        t->tca__pad2 = 0;
 809
 810        nest = nla_nest_start(skb, TCA_ACT_TAB);
 811        if (nest == NULL)
 812                goto out_module_put;
 813
 814        err = a->ops->walk(skb, &dcb, RTM_DELACTION, a);
 815        if (err < 0)
 816                goto out_module_put;
 817        if (err == 0)
 818                goto noflush_out;
 819
 820        nla_nest_end(skb, nest);
 821
 822        nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 823        nlh->nlmsg_flags |= NLM_F_ROOT;
 824        module_put(a->ops->owner);
 825        kfree(a);
 826        err = rtnetlink_send(skb, net, pid, RTNLGRP_TC,
 827                             n->nlmsg_flags & NLM_F_ECHO);
 828        if (err > 0)
 829                return 0;
 830
 831        return err;
 832
 833out_module_put:
 834        module_put(a->ops->owner);
 835err_out:
 836noflush_out:
 837        kfree_skb(skb);
 838        kfree(a);
 839        return err;
 840}
 841
 842static int
 843tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 844              u32 pid, int event)
 845{
 846        int i, ret;
 847        struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 848        struct tc_action *head = NULL, *act, *act_prev = NULL;
 849
 850        ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
 851        if (ret < 0)
 852                return ret;
 853
 854        if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
 855                if (tb[1] != NULL)
 856                        return tca_action_flush(net, tb[1], n, pid);
 857                else
 858                        return -EINVAL;
 859        }
 860
 861        for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 862                act = tcf_action_get_1(tb[i], n, pid);
 863                if (IS_ERR(act)) {
 864                        ret = PTR_ERR(act);
 865                        goto err;
 866                }
 867                act->order = i;
 868
 869                if (head == NULL)
 870                        head = act;
 871                else
 872                        act_prev->next = act;
 873                act_prev = act;
 874        }
 875
 876        if (event == RTM_GETACTION)
 877                ret = act_get_notify(net, pid, n, head, event);
 878        else { /* delete */
 879                struct sk_buff *skb;
 880
 881                skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 882                if (!skb) {
 883                        ret = -ENOBUFS;
 884                        goto err;
 885                }
 886
 887                if (tca_get_fill(skb, head, pid, n->nlmsg_seq, 0, event,
 888                                 0, 1) <= 0) {
 889                        kfree_skb(skb);
 890                        ret = -EINVAL;
 891                        goto err;
 892                }
 893
 894                /* now do the delete */
 895                tcf_action_destroy(head, 0);
 896                ret = rtnetlink_send(skb, net, pid, RTNLGRP_TC,
 897                                     n->nlmsg_flags & NLM_F_ECHO);
 898                if (ret > 0)
 899                        return 0;
 900                return ret;
 901        }
 902err:
 903        cleanup_a(head);
 904        return ret;
 905}
 906
 907static int tcf_add_notify(struct net *net, struct tc_action *a,
 908                          u32 pid, u32 seq, int event, u16 flags)
 909{
 910        struct tcamsg *t;
 911        struct nlmsghdr *nlh;
 912        struct sk_buff *skb;
 913        struct nlattr *nest;
 914        unsigned char *b;
 915        int err = 0;
 916
 917        skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 918        if (!skb)
 919                return -ENOBUFS;
 920
 921        b = skb_tail_pointer(skb);
 922
 923        nlh = nlmsg_put(skb, pid, seq, event, sizeof(*t), flags);
 924        if (!nlh)
 925                goto out_kfree_skb;
 926        t = nlmsg_data(nlh);
 927        t->tca_family = AF_UNSPEC;
 928        t->tca__pad1 = 0;
 929        t->tca__pad2 = 0;
 930
 931        nest = nla_nest_start(skb, TCA_ACT_TAB);
 932        if (nest == NULL)
 933                goto out_kfree_skb;
 934
 935        if (tcf_action_dump(skb, a, 0, 0) < 0)
 936                goto out_kfree_skb;
 937
 938        nla_nest_end(skb, nest);
 939
 940        nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 941        NETLINK_CB(skb).dst_group = RTNLGRP_TC;
 942
 943        err = rtnetlink_send(skb, net, pid, RTNLGRP_TC, flags & NLM_F_ECHO);
 944        if (err > 0)
 945                err = 0;
 946        return err;
 947
 948out_kfree_skb:
 949        kfree_skb(skb);
 950        return -1;
 951}
 952
 953
 954static int
 955tcf_action_add(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 956               u32 pid, int ovr)
 957{
 958        int ret = 0;
 959        struct tc_action *act;
 960        struct tc_action *a;
 961        u32 seq = n->nlmsg_seq;
 962
 963        act = tcf_action_init(nla, NULL, NULL, ovr, 0);
 964        if (act == NULL)
 965                goto done;
 966        if (IS_ERR(act)) {
 967                ret = PTR_ERR(act);
 968                goto done;
 969        }
 970
 971        /* dump then free all the actions after update; inserted policy
 972         * stays intact
 973         */
 974        ret = tcf_add_notify(net, act, pid, seq, RTM_NEWACTION, n->nlmsg_flags);
 975        for (a = act; a; a = act) {
 976                act = a->next;
 977                kfree(a);
 978        }
 979done:
 980        return ret;
 981}
 982
 983static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
 984{
 985        struct net *net = sock_net(skb->sk);
 986        struct nlattr *tca[TCA_ACT_MAX + 1];
 987        u32 pid = skb ? NETLINK_CB(skb).pid : 0;
 988        int ret = 0, ovr = 0;
 989
 990        ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ACT_MAX, NULL);
 991        if (ret < 0)
 992                return ret;
 993
 994        if (tca[TCA_ACT_TAB] == NULL) {
 995                pr_notice("tc_ctl_action: received NO action attribs\n");
 996                return -EINVAL;
 997        }
 998
 999        /* n->nlmsg_flags & NLM_F_CREATE */
1000        switch (n->nlmsg_type) {
1001        case RTM_NEWACTION:
1002                /* we are going to assume all other flags
1003                 * imply create only if it doesn't exist
1004                 * Note that CREATE | EXCL implies that
1005                 * but since we want avoid ambiguity (eg when flags
1006                 * is zero) then just set this
1007                 */
1008                if (n->nlmsg_flags & NLM_F_REPLACE)
1009                        ovr = 1;
1010replay:
1011                ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, pid, ovr);
1012                if (ret == -EAGAIN)
1013                        goto replay;
1014                break;
1015        case RTM_DELACTION:
1016                ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1017                                    pid, RTM_DELACTION);
1018                break;
1019        case RTM_GETACTION:
1020                ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1021                                    pid, RTM_GETACTION);
1022                break;
1023        default:
1024                BUG();
1025        }
1026
1027        return ret;
1028}
1029
1030static struct nlattr *
1031find_dump_kind(const struct nlmsghdr *n)
1032{
1033        struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
1034        struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1035        struct nlattr *nla[TCAA_MAX + 1];
1036        struct nlattr *kind;
1037
1038        if (nlmsg_parse(n, sizeof(struct tcamsg), nla, TCAA_MAX, NULL) < 0)
1039                return NULL;
1040        tb1 = nla[TCA_ACT_TAB];
1041        if (tb1 == NULL)
1042                return NULL;
1043
1044        if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
1045                      NLMSG_ALIGN(nla_len(tb1)), NULL) < 0)
1046                return NULL;
1047
1048        if (tb[1] == NULL)
1049                return NULL;
1050        if (nla_parse(tb2, TCA_ACT_MAX, nla_data(tb[1]),
1051                      nla_len(tb[1]), NULL) < 0)
1052                return NULL;
1053        kind = tb2[TCA_ACT_KIND];
1054
1055        return kind;
1056}
1057
1058static int
1059tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1060{
1061        struct nlmsghdr *nlh;
1062        unsigned char *b = skb_tail_pointer(skb);
1063        struct nlattr *nest;
1064        struct tc_action_ops *a_o;
1065        struct tc_action a;
1066        int ret = 0;
1067        struct tcamsg *t = (struct tcamsg *) nlmsg_data(cb->nlh);
1068        struct nlattr *kind = find_dump_kind(cb->nlh);
1069
1070        if (kind == NULL) {
1071                pr_info("tc_dump_action: action bad kind\n");
1072                return 0;
1073        }
1074
1075        a_o = tc_lookup_action(kind);
1076        if (a_o == NULL)
1077                return 0;
1078
1079        memset(&a, 0, sizeof(struct tc_action));
1080        a.ops = a_o;
1081
1082        if (a_o->walk == NULL) {
1083                WARN(1, "tc_dump_action: %s !capable of dumping table\n",
1084                     a_o->kind);
1085                goto out_module_put;
1086        }
1087
1088        nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
1089                        cb->nlh->nlmsg_type, sizeof(*t), 0);
1090        if (!nlh)
1091                goto out_module_put;
1092        t = nlmsg_data(nlh);
1093        t->tca_family = AF_UNSPEC;
1094        t->tca__pad1 = 0;
1095        t->tca__pad2 = 0;
1096
1097        nest = nla_nest_start(skb, TCA_ACT_TAB);
1098        if (nest == NULL)
1099                goto out_module_put;
1100
1101        ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
1102        if (ret < 0)
1103                goto out_module_put;
1104
1105        if (ret > 0) {
1106                nla_nest_end(skb, nest);
1107                ret = skb->len;
1108        } else
1109                nla_nest_cancel(skb, nest);
1110
1111        nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1112        if (NETLINK_CB(cb->skb).pid && ret)
1113                nlh->nlmsg_flags |= NLM_F_MULTI;
1114        module_put(a_o->owner);
1115        return skb->len;
1116
1117out_module_put:
1118        module_put(a_o->owner);
1119        nlmsg_trim(skb, b);
1120        return skb->len;
1121}
1122
1123static int __init tc_action_init(void)
1124{
1125        rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, NULL);
1126        rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, NULL);
1127        rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
1128                      NULL);
1129
1130        return 0;
1131}
1132
1133subsys_initcall(tc_action_init);
1134
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.