net/sched/act_api.c

   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/pkt_cls.h>
  28 #include <net/act_api.h>
  29 #include <net/netlink.h>
  30
  31 static void free_tcf(struct rcu_head *head)
  32 {
  33         struct tc_action *p = container_of(head, struct tc_action, tcfa_rcu);
  34
  35         free_percpu(p->cpu_bstats);
  36         free_percpu(p->cpu_qstats);
  37
  38         if (p->act_cookie) {
  39                 kfree(p->act_cookie->data);
  40                 kfree(p->act_cookie);
  41         }
  42
  43         kfree(p);
  44 }
  45
  46 static void tcf_hash_destroy(struct tcf_hashinfo *hinfo, struct tc_action *p)
  47 {
  48         spin_lock_bh(&hinfo->lock);
  49         hlist_del(&p->tcfa_head);
  50         spin_unlock_bh(&hinfo->lock);
  51         gen_kill_estimator(&p->tcfa_rate_est);
  52         /*
  53          * gen_estimator est_timer() might access p->tcfa_lock
  54          * or bstats, wait a RCU grace period before freeing p
  55          */
  56         call_rcu(&p->tcfa_rcu, free_tcf);
  57 }
  58
  59 int __tcf_hash_release(struct tc_action *p, bool bind, bool strict)
  60 {
  61         int ret = 0;
  62
  63         if (p) {
  64                 if (bind)
  65                         p->tcfa_bindcnt--;
  66                 else if (strict && p->tcfa_bindcnt > 0)
  67                         return -EPERM;
  68
  69                 p->tcfa_refcnt--;
  70                 if (p->tcfa_bindcnt <= 0 && p->tcfa_refcnt <= 0) {
  71                         if (p->ops->cleanup)
  72                                 p->ops->cleanup(p, bind);
  73                         tcf_hash_destroy(p->hinfo, p);
  74                         ret = ACT_P_DELETED;
  75                 }
  76         }
  77
  78         return ret;
  79 }
  80 EXPORT_SYMBOL(__tcf_hash_release);
  81
  82 static int tcf_dump_walker(struct tcf_hashinfo *hinfo, struct sk_buff *skb,
  83                            struct netlink_callback *cb)
  84 {
  85         int err = 0, index = -1, i = 0, s_i = 0, n_i = 0;
  86         struct nlattr *nest;
  87
  88         spin_lock_bh(&hinfo->lock);
  89
  90         s_i = cb->args[0];
  91
  92         for (i = 0; i < (hinfo->hmask + 1); i++) {
  93                 struct hlist_head *head;
  94                 struct tc_action *p;
  95
  96                 head = &hinfo->htab[tcf_hash(i, hinfo->hmask)];
  97
  98                 hlist_for_each_entry_rcu(p, head, tcfa_head) {
  99                         index++;
 100                         if (index < s_i)
 101                                 continue;
 102
 103                         nest = nla_nest_start(skb, n_i);
 104                         if (nest == NULL)
 105                                 goto nla_put_failure;
 106                         err = tcf_action_dump_1(skb, p, 0, 0);
 107                         if (err < 0) {
 108                                 index--;
 109                                 nlmsg_trim(skb, nest);
 110                                 goto done;
 111                         }
 112                         nla_nest_end(skb, nest);
 113                         n_i++;
 114                         if (n_i >= TCA_ACT_MAX_PRIO)
 115                                 goto done;
 116                 }
 117         }
 118 done:
 119         spin_unlock_bh(&hinfo->lock);
 120         if (n_i)
 121                 cb->args[0] += n_i;
 122         return n_i;
 123
 124 nla_put_failure:
 125         nla_nest_cancel(skb, nest);
 126         goto done;
 127 }
 128
 129 static int tcf_del_walker(struct tcf_hashinfo *hinfo, struct sk_buff *skb,
 130                           const struct tc_action_ops *ops)
 131 {
 132         struct nlattr *nest;
 133         int i = 0, n_i = 0;
 134         int ret = -EINVAL;
 135
 136         nest = nla_nest_start(skb, 0);
 137         if (nest == NULL)
 138                 goto nla_put_failure;
 139         if (nla_put_string(skb, TCA_KIND, ops->kind))
 140                 goto nla_put_failure;
 141         for (i = 0; i < (hinfo->hmask + 1); i++) {
 142                 struct hlist_head *head;
 143                 struct hlist_node *n;
 144                 struct tc_action *p;
 145
 146                 head = &hinfo->htab[tcf_hash(i, hinfo->hmask)];
 147                 hlist_for_each_entry_safe(p, n, head, tcfa_head) {
 148                         ret = __tcf_hash_release(p, false, true);
 149                         if (ret == ACT_P_DELETED) {
 150                                 module_put(p->ops->owner);
 151                                 n_i++;
 152                         } else if (ret < 0)
 153                                 goto nla_put_failure;
 154                 }
 155         }
 156         if (nla_put_u32(skb, TCA_FCNT, n_i))
 157                 goto nla_put_failure;
 158         nla_nest_end(skb, nest);
 159
 160         return n_i;
 161 nla_put_failure:
 162         nla_nest_cancel(skb, nest);
 163         return ret;
 164 }
 165
 166 int tcf_generic_walker(struct tc_action_net *tn, struct sk_buff *skb,
 167                        struct netlink_callback *cb, int type,
 168                        const struct tc_action_ops *ops)
 169 {
 170         struct tcf_hashinfo *hinfo = tn->hinfo;
 171
 172         if (type == RTM_DELACTION) {
 173                 return tcf_del_walker(hinfo, skb, ops);
 174         } else if (type == RTM_GETACTION) {
 175                 return tcf_dump_walker(hinfo, skb, cb);
 176         } else {
 177                 WARN(1, "tcf_generic_walker: unknown action %d\n", type);
 178                 return -EINVAL;
 179         }
 180 }
 181 EXPORT_SYMBOL(tcf_generic_walker);
 182
 183 static struct tc_action *tcf_hash_lookup(u32 index, struct tcf_hashinfo *hinfo)
 184 {
 185         struct tc_action *p = NULL;
 186         struct hlist_head *head;
 187
 188         spin_lock_bh(&hinfo->lock);
 189         head = &hinfo->htab[tcf_hash(index, hinfo->hmask)];
 190         hlist_for_each_entry_rcu(p, head, tcfa_head)
 191                 if (p->tcfa_index == index)
 192                         break;
 193         spin_unlock_bh(&hinfo->lock);
 194
 195         return p;
 196 }
 197
 198 u32 tcf_hash_new_index(struct tc_action_net *tn)
 199 {
 200         struct tcf_hashinfo *hinfo = tn->hinfo;
 201         u32 val = hinfo->index;
 202
 203         do {
 204                 if (++val == 0)
 205                         val = 1;
 206         } while (tcf_hash_lookup(val, hinfo));
 207
 208         hinfo->index = val;
 209         return val;
 210 }
 211 EXPORT_SYMBOL(tcf_hash_new_index);
 212
 213 int tcf_hash_search(struct tc_action_net *tn, struct tc_action **a, u32 index)
 214 {
 215         struct tcf_hashinfo *hinfo = tn->hinfo;
 216         struct tc_action *p = tcf_hash_lookup(index, hinfo);
 217
 218         if (p) {
 219                 *a = p;
 220                 return 1;
 221         }
 222         return 0;
 223 }
 224 EXPORT_SYMBOL(tcf_hash_search);
 225
 226 bool tcf_hash_check(struct tc_action_net *tn, u32 index, struct tc_action **a,
 227                     int bind)
 228 {
 229         struct tcf_hashinfo *hinfo = tn->hinfo;
 230         struct tc_action *p = NULL;
 231
 232         if (index && (p = tcf_hash_lookup(index, hinfo)) != NULL) {
 233                 if (bind)
 234                         p->tcfa_bindcnt++;
 235                 p->tcfa_refcnt++;
 236                 *a = p;
 237                 return true;
 238         }
 239         return false;
 240 }
 241 EXPORT_SYMBOL(tcf_hash_check);
 242
 243 void tcf_hash_cleanup(struct tc_action *a, struct nlattr *est)
 244 {
 245         if (est)
 246                 gen_kill_estimator(&a->tcfa_rate_est);
 247         call_rcu(&a->tcfa_rcu, free_tcf);
 248 }
 249 EXPORT_SYMBOL(tcf_hash_cleanup);
 250
 251 int tcf_hash_create(struct tc_action_net *tn, u32 index, struct nlattr *est,
 252                     struct tc_action **a, const struct tc_action_ops *ops,
 253                     int bind, bool cpustats)
 254 {
 255         struct tc_action *p = kzalloc(ops->size, GFP_KERNEL);
 256         struct tcf_hashinfo *hinfo = tn->hinfo;
 257         int err = -ENOMEM;
 258
 259         if (unlikely(!p))
 260                 return -ENOMEM;
 261         p->tcfa_refcnt = 1;
 262         if (bind)
 263                 p->tcfa_bindcnt = 1;
 264
 265         if (cpustats) {
 266                 p->cpu_bstats = netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
 267                 if (!p->cpu_bstats) {
 268 err1:
 269                         kfree(p);
 270                         return err;
 271                 }
 272                 p->cpu_qstats = alloc_percpu(struct gnet_stats_queue);
 273                 if (!p->cpu_qstats) {
 274 err2:
 275                         free_percpu(p->cpu_bstats);
 276                         goto err1;
 277                 }
 278         }
 279         spin_lock_init(&p->tcfa_lock);
 280         INIT_HLIST_NODE(&p->tcfa_head);
 281         p->tcfa_index = index ? index : tcf_hash_new_index(tn);
 282         p->tcfa_tm.install = jiffies;
 283         p->tcfa_tm.lastuse = jiffies;
 284         p->tcfa_tm.firstuse = 0;
 285         if (est) {
 286                 err = gen_new_estimator(&p->tcfa_bstats, p->cpu_bstats,
 287                                         &p->tcfa_rate_est,
 288                                         &p->tcfa_lock, NULL, est);
 289                 if (err) {
 290                         free_percpu(p->cpu_qstats);
 291                         goto err2;
 292                 }
 293         }
 294
 295         p->hinfo = hinfo;
 296         p->ops = ops;
 297         INIT_LIST_HEAD(&p->list);
 298         *a = p;
 299         return 0;
 300 }
 301 EXPORT_SYMBOL(tcf_hash_create);
 302
 303 void tcf_hash_insert(struct tc_action_net *tn, struct tc_action *a)
 304 {
 305         struct tcf_hashinfo *hinfo = tn->hinfo;
 306         unsigned int h = tcf_hash(a->tcfa_index, hinfo->hmask);
 307
 308         spin_lock_bh(&hinfo->lock);
 309         hlist_add_head(&a->tcfa_head, &hinfo->htab[h]);
 310         spin_unlock_bh(&hinfo->lock);
 311 }
 312 EXPORT_SYMBOL(tcf_hash_insert);
 313
 314 void tcf_hashinfo_destroy(const struct tc_action_ops *ops,
 315                           struct tcf_hashinfo *hinfo)
 316 {
 317         int i;
 318
 319         for (i = 0; i < hinfo->hmask + 1; i++) {
 320                 struct tc_action *p;
 321                 struct hlist_node *n;
 322
 323                 hlist_for_each_entry_safe(p, n, &hinfo->htab[i], tcfa_head) {
 324                         int ret;
 325
 326                         ret = __tcf_hash_release(p, false, true);
 327                         if (ret == ACT_P_DELETED)
 328                                 module_put(ops->owner);
 329                         else if (ret < 0)
 330                                 return;
 331                 }
 332         }
 333         kfree(hinfo->htab);
 334 }
 335 EXPORT_SYMBOL(tcf_hashinfo_destroy);
 336
 337 static LIST_HEAD(act_base);
 338 static DEFINE_RWLOCK(act_mod_lock);
 339
 340 int tcf_register_action(struct tc_action_ops *act,
 341                         struct pernet_operations *ops)
 342 {
 343         struct tc_action_ops *a;
 344         int ret;
 345
 346         if (!act->act || !act->dump || !act->init || !act->walk || !act->lookup)
 347                 return -EINVAL;
 348
 349         /* We have to register pernet ops before making the action ops visible,
 350          * otherwise tcf_action_init_1() could get a partially initialized
 351          * netns.
 352          */
 353         ret = register_pernet_subsys(ops);
 354         if (ret)
 355                 return ret;
 356
 357         write_lock(&act_mod_lock);
 358         list_for_each_entry(a, &act_base, head) {
 359                 if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
 360                         write_unlock(&act_mod_lock);
 361                         unregister_pernet_subsys(ops);
 362                         return -EEXIST;
 363                 }
 364         }
 365         list_add_tail(&act->head, &act_base);
 366         write_unlock(&act_mod_lock);
 367
 368         return 0;
 369 }
 370 EXPORT_SYMBOL(tcf_register_action);
 371
 372 int tcf_unregister_action(struct tc_action_ops *act,
 373                           struct pernet_operations *ops)
 374 {
 375         struct tc_action_ops *a;
 376         int err = -ENOENT;
 377
 378         write_lock(&act_mod_lock);
 379         list_for_each_entry(a, &act_base, head) {
 380                 if (a == act) {
 381                         list_del(&act->head);
 382                         err = 0;
 383                         break;
 384                 }
 385         }
 386         write_unlock(&act_mod_lock);
 387         if (!err)
 388                 unregister_pernet_subsys(ops);
 389         return err;
 390 }
 391 EXPORT_SYMBOL(tcf_unregister_action);
 392
 393 /* lookup by name */
 394 static struct tc_action_ops *tc_lookup_action_n(char *kind)
 395 {
 396         struct tc_action_ops *a, *res = NULL;
 397
 398         if (kind) {
 399                 read_lock(&act_mod_lock);
 400                 list_for_each_entry(a, &act_base, head) {
 401                         if (strcmp(kind, a->kind) == 0) {
 402                                 if (try_module_get(a->owner))
 403                                         res = a;
 404                                 break;
 405                         }
 406                 }
 407                 read_unlock(&act_mod_lock);
 408         }
 409         return res;
 410 }
 411
 412 /* lookup by nlattr */
 413 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
 414 {
 415         struct tc_action_ops *a, *res = NULL;
 416
 417         if (kind) {
 418                 read_lock(&act_mod_lock);
 419                 list_for_each_entry(a, &act_base, head) {
 420                         if (nla_strcmp(kind, a->kind) == 0) {
 421                                 if (try_module_get(a->owner))
 422                                         res = a;
 423                                 break;
 424                         }
 425                 }
 426                 read_unlock(&act_mod_lock);
 427         }
 428         return res;
 429 }
 430
 431 /*TCA_ACT_MAX_PRIO is 32, there count upto 32 */
 432 #define TCA_ACT_MAX_PRIO_MASK 0x1FF
 433 int tcf_action_exec(struct sk_buff *skb, struct tc_action **actions,
 434                     int nr_actions, struct tcf_result *res)
 435 {
 436         int ret = -1, i;
 437         u32 jmp_prgcnt = 0;
 438         u32 jmp_ttl = TCA_ACT_MAX_PRIO; /*matches actions per filter */
 439
 440         if (skb_skip_tc_classify(skb))
 441                 return TC_ACT_OK;
 442
 443 restart_act_graph:
 444         for (i = 0; i < nr_actions; i++) {
 445                 const struct tc_action *a = actions[i];
 446
 447                 if (jmp_prgcnt > 0) {
 448                         jmp_prgcnt -= 1;
 449                         continue;
 450                 }
 451 repeat:
 452                 ret = a->ops->act(skb, a, res);
 453                 if (ret == TC_ACT_REPEAT)
 454                         goto repeat;    /* we need a ttl - JHS */
 455
 456                 if (TC_ACT_EXT_CMP(ret, TC_ACT_JUMP)) {
 457                         jmp_prgcnt = ret & TCA_ACT_MAX_PRIO_MASK;
 458                         if (!jmp_prgcnt || (jmp_prgcnt > nr_actions)) {
 459                                 /* faulty opcode, stop pipeline */
 460                                 return TC_ACT_OK;
 461                         } else {
 462                                 jmp_ttl -= 1;
 463                                 if (jmp_ttl > 0)
 464                                         goto restart_act_graph;
 465                                 else /* faulty graph, stop pipeline */
 466                                         return TC_ACT_OK;
 467                         }
 468                 }
 469
 470                 if (ret != TC_ACT_PIPE)
 471                         break;
 472         }
 473
 474         return ret;
 475 }
 476 EXPORT_SYMBOL(tcf_action_exec);
 477
 478 int tcf_action_destroy(struct list_head *actions, int bind)
 479 {
 480         struct tc_action *a, *tmp;
 481         int ret = 0;
 482
 483         list_for_each_entry_safe(a, tmp, actions, list) {
 484                 ret = __tcf_hash_release(a, bind, true);
 485                 if (ret == ACT_P_DELETED)
 486                         module_put(a->ops->owner);
 487                 else if (ret < 0)
 488                         return ret;
 489         }
 490         return ret;
 491 }
 492
 493 int
 494 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 495 {
 496         return a->ops->dump(skb, a, bind, ref);
 497 }
 498
 499 int
 500 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 501 {
 502         int err = -EINVAL;
 503         unsigned char *b = skb_tail_pointer(skb);
 504         struct nlattr *nest;
 505
 506         if (nla_put_string(skb, TCA_KIND, a->ops->kind))
 507                 goto nla_put_failure;
 508         if (tcf_action_copy_stats(skb, a, 0))
 509                 goto nla_put_failure;
 510         if (a->act_cookie) {
 511                 if (nla_put(skb, TCA_ACT_COOKIE, a->act_cookie->len,
 512                             a->act_cookie->data))
 513                         goto nla_put_failure;
 514         }
 515
 516         nest = nla_nest_start(skb, TCA_OPTIONS);
 517         if (nest == NULL)
 518                 goto nla_put_failure;
 519         err = tcf_action_dump_old(skb, a, bind, ref);
 520         if (err > 0) {
 521                 nla_nest_end(skb, nest);
 522                 return err;
 523         }
 524
 525 nla_put_failure:
 526         nlmsg_trim(skb, b);
 527         return -1;
 528 }
 529 EXPORT_SYMBOL(tcf_action_dump_1);
 530
 531 int tcf_action_dump(struct sk_buff *skb, struct list_head *actions,
 532                     int bind, int ref)
 533 {
 534         struct tc_action *a;
 535         int err = -EINVAL;
 536         struct nlattr *nest;
 537
 538         list_for_each_entry(a, actions, list) {
 539                 nest = nla_nest_start(skb, a->order);
 540                 if (nest == NULL)
 541                         goto nla_put_failure;
 542                 err = tcf_action_dump_1(skb, a, bind, ref);
 543                 if (err < 0)
 544                         goto errout;
 545                 nla_nest_end(skb, nest);
 546         }
 547
 548         return 0;
 549
 550 nla_put_failure:
 551         err = -EINVAL;
 552 errout:
 553         nla_nest_cancel(skb, nest);
 554         return err;
 555 }
 556
 557 static struct tc_cookie *nla_memdup_cookie(struct nlattr **tb)
 558 {
 559         struct tc_cookie *c = kzalloc(sizeof(*c), GFP_KERNEL);
 560         if (!c)
 561                 return NULL;
 562
 563         c->data = nla_memdup(tb[TCA_ACT_COOKIE], GFP_KERNEL);
 564         if (!c->data) {
 565                 kfree(c);
 566                 return NULL;
 567         }
 568         c->len = nla_len(tb[TCA_ACT_COOKIE]);
 569
 570         return c;
 571 }
 572
 573 struct tc_action *tcf_action_init_1(struct net *net, struct nlattr *nla,
 574                                     struct nlattr *est, char *name, int ovr,
 575                                     int bind)
 576 {
 577         struct tc_action *a;
 578         struct tc_action_ops *a_o;
 579         struct tc_cookie *cookie = NULL;
 580         char act_name[IFNAMSIZ];
 581         struct nlattr *tb[TCA_ACT_MAX + 1];
 582         struct nlattr *kind;
 583         int err;
 584
 585         if (name == NULL) {
 586                 err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL, NULL);
 587                 if (err < 0)
 588                         goto err_out;
 589                 err = -EINVAL;
 590                 kind = tb[TCA_ACT_KIND];
 591                 if (kind == NULL)
 592                         goto err_out;
 593                 if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
 594                         goto err_out;
 595                 if (tb[TCA_ACT_COOKIE]) {
 596                         int cklen = nla_len(tb[TCA_ACT_COOKIE]);
 597
 598                         if (cklen > TC_COOKIE_MAX_SIZE)
 599                                 goto err_out;
 600
 601                         cookie = nla_memdup_cookie(tb);
 602                         if (!cookie) {
 603                                 err = -ENOMEM;
 604                                 goto err_out;
 605                         }
 606                 }
 607         } else {
 608                 err = -EINVAL;
 609                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
 610                         goto err_out;
 611         }
 612
 613         a_o = tc_lookup_action_n(act_name);
 614         if (a_o == NULL) {
 615 #ifdef CONFIG_MODULES
 616                 rtnl_unlock();
 617                 request_module("act_%s", act_name);
 618                 rtnl_lock();
 619
 620                 a_o = tc_lookup_action_n(act_name);
 621
 622                 /* We dropped the RTNL semaphore in order to
 623                  * perform the module load.  So, even if we
 624                  * succeeded in loading the module we have to
 625                  * tell the caller to replay the request.  We
 626                  * indicate this using -EAGAIN.
 627                  */
 628                 if (a_o != NULL) {
 629                         err = -EAGAIN;
 630                         goto err_mod;
 631                 }
 632 #endif
 633                 err = -ENOENT;
 634                 goto err_out;
 635         }
 636
 637         /* backward compatibility for policer */
 638         if (name == NULL)
 639                 err = a_o->init(net, tb[TCA_ACT_OPTIONS], est, &a, ovr, bind);
 640         else
 641                 err = a_o->init(net, nla, est, &a, ovr, bind);
 642         if (err < 0)
 643                 goto err_mod;
 644
 645         if (name == NULL && tb[TCA_ACT_COOKIE]) {
 646                 if (a->act_cookie) {
 647                         kfree(a->act_cookie->data);
 648                         kfree(a->act_cookie);
 649                 }
 650                 a->act_cookie = cookie;
 651         }
 652
 653         /* module count goes up only when brand new policy is created
 654          * if it exists and is only bound to in a_o->init() then
 655          * ACT_P_CREATED is not returned (a zero is).
 656          */
 657         if (err != ACT_P_CREATED)
 658                 module_put(a_o->owner);
 659
 660         return a;
 661
 662 err_mod:
 663         module_put(a_o->owner);
 664 err_out:
 665         if (cookie) {
 666                 kfree(cookie->data);
 667                 kfree(cookie);
 668         }
 669         return ERR_PTR(err);
 670 }
 671
 672 static void cleanup_a(struct list_head *actions, int ovr)
 673 {
 674         struct tc_action *a;
 675
 676         if (!ovr)
 677                 return;
 678
 679         list_for_each_entry(a, actions, list)
 680                 a->tcfa_refcnt--;
 681 }
 682
 683 int tcf_action_init(struct net *net, struct nlattr *nla, struct nlattr *est,
 684                     char *name, int ovr, int bind, struct list_head *actions)
 685 {
 686         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 687         struct tc_action *act;
 688         int err;
 689         int i;
 690
 691         err = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL, NULL);
 692         if (err < 0)
 693                 return err;
 694
 695         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 696                 act = tcf_action_init_1(net, tb[i], est, name, ovr, bind);
 697                 if (IS_ERR(act)) {
 698                         err = PTR_ERR(act);
 699                         goto err;
 700                 }
 701                 act->order = i;
 702                 if (ovr)
 703                         act->tcfa_refcnt++;
 704                 list_add_tail(&act->list, actions);
 705         }
 706
 707         /* Remove the temp refcnt which was necessary to protect against
 708          * destroying an existing action which was being replaced
 709          */
 710         cleanup_a(actions, ovr);
 711         return 0;
 712
 713 err:
 714         tcf_action_destroy(actions, bind);
 715         return err;
 716 }
 717
 718 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *p,
 719                           int compat_mode)
 720 {
 721         int err = 0;
 722         struct gnet_dump d;
 723
 724         if (p == NULL)
 725                 goto errout;
 726
 727         /* compat_mode being true specifies a call that is supposed
 728          * to add additional backward compatibility statistic TLVs.
 729          */
 730         if (compat_mode) {
 731                 if (p->type == TCA_OLD_COMPAT)
 732                         err = gnet_stats_start_copy_compat(skb, 0,
 733                                                            TCA_STATS,
 734                                                            TCA_XSTATS,
 735                                                            &p->tcfa_lock, &d,
 736                                                            TCA_PAD);
 737                 else
 738                         return 0;
 739         } else
 740                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
 741                                             &p->tcfa_lock, &d, TCA_ACT_PAD);
 742
 743         if (err < 0)
 744                 goto errout;
 745
 746         if (gnet_stats_copy_basic(NULL, &d, p->cpu_bstats, &p->tcfa_bstats) < 0 ||
 747             gnet_stats_copy_rate_est(&d, &p->tcfa_rate_est) < 0 ||
 748             gnet_stats_copy_queue(&d, p->cpu_qstats,
 749                                   &p->tcfa_qstats,
 750                                   p->tcfa_qstats.qlen) < 0)
 751                 goto errout;
 752
 753         if (gnet_stats_finish_copy(&d) < 0)
 754                 goto errout;
 755
 756         return 0;
 757
 758 errout:
 759         return -1;
 760 }
 761
 762 static int tca_get_fill(struct sk_buff *skb, struct list_head *actions,
 763                         u32 portid, u32 seq, u16 flags, int event, int bind,
 764                         int ref)
 765 {
 766         struct tcamsg *t;
 767         struct nlmsghdr *nlh;
 768         unsigned char *b = skb_tail_pointer(skb);
 769         struct nlattr *nest;
 770
 771         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
 772         if (!nlh)
 773                 goto out_nlmsg_trim;
 774         t = nlmsg_data(nlh);
 775         t->tca_family = AF_UNSPEC;
 776         t->tca__pad1 = 0;
 777         t->tca__pad2 = 0;
 778
 779         nest = nla_nest_start(skb, TCA_ACT_TAB);
 780         if (nest == NULL)
 781                 goto out_nlmsg_trim;
 782
 783         if (tcf_action_dump(skb, actions, bind, ref) < 0)
 784                 goto out_nlmsg_trim;
 785
 786         nla_nest_end(skb, nest);
 787
 788         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 789         return skb->len;
 790
 791 out_nlmsg_trim:
 792         nlmsg_trim(skb, b);
 793         return -1;
 794 }
 795
 796 static int
 797 act_get_notify(struct net *net, u32 portid, struct nlmsghdr *n,
 798                struct list_head *actions, int event)
 799 {
 800         struct sk_buff *skb;
 801
 802         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 803         if (!skb)
 804                 return -ENOBUFS;
 805         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, event,
 806                          0, 0) <= 0) {
 807                 kfree_skb(skb);
 808                 return -EINVAL;
 809         }
 810
 811         return rtnl_unicast(skb, net, portid);
 812 }
 813
 814 static struct tc_action *tcf_action_get_1(struct net *net, struct nlattr *nla,
 815                                           struct nlmsghdr *n, u32 portid)
 816 {
 817         struct nlattr *tb[TCA_ACT_MAX + 1];
 818         const struct tc_action_ops *ops;
 819         struct tc_action *a;
 820         int index;
 821         int err;
 822
 823         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL, NULL);
 824         if (err < 0)
 825                 goto err_out;
 826
 827         err = -EINVAL;
 828         if (tb[TCA_ACT_INDEX] == NULL ||
 829             nla_len(tb[TCA_ACT_INDEX]) < sizeof(index))
 830                 goto err_out;
 831         index = nla_get_u32(tb[TCA_ACT_INDEX]);
 832
 833         err = -EINVAL;
 834         ops = tc_lookup_action(tb[TCA_ACT_KIND]);
 835         if (!ops) /* could happen in batch of actions */
 836                 goto err_out;
 837         err = -ENOENT;
 838         if (ops->lookup(net, &a, index) == 0)
 839                 goto err_mod;
 840
 841         module_put(ops->owner);
 842         return a;
 843
 844 err_mod:
 845         module_put(ops->owner);
 846 err_out:
 847         return ERR_PTR(err);
 848 }
 849
 850 static int tca_action_flush(struct net *net, struct nlattr *nla,
 851                             struct nlmsghdr *n, u32 portid)
 852 {
 853         struct sk_buff *skb;
 854         unsigned char *b;
 855         struct nlmsghdr *nlh;
 856         struct tcamsg *t;
 857         struct netlink_callback dcb;
 858         struct nlattr *nest;
 859         struct nlattr *tb[TCA_ACT_MAX + 1];
 860         const struct tc_action_ops *ops;
 861         struct nlattr *kind;
 862         int err = -ENOMEM;
 863
 864         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 865         if (!skb) {
 866                 pr_debug("tca_action_flush: failed skb alloc\n");
 867                 return err;
 868         }
 869
 870         b = skb_tail_pointer(skb);
 871
 872         err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL, NULL);
 873         if (err < 0)
 874                 goto err_out;
 875
 876         err = -EINVAL;
 877         kind = tb[TCA_ACT_KIND];
 878         ops = tc_lookup_action(kind);
 879         if (!ops) /*some idjot trying to flush unknown action */
 880                 goto err_out;
 881
 882         nlh = nlmsg_put(skb, portid, n->nlmsg_seq, RTM_DELACTION,
 883                         sizeof(*t), 0);
 884         if (!nlh)
 885                 goto out_module_put;
 886         t = nlmsg_data(nlh);
 887         t->tca_family = AF_UNSPEC;
 888         t->tca__pad1 = 0;
 889         t->tca__pad2 = 0;
 890
 891         nest = nla_nest_start(skb, TCA_ACT_TAB);
 892         if (nest == NULL)
 893                 goto out_module_put;
 894
 895         err = ops->walk(net, skb, &dcb, RTM_DELACTION, ops);
 896         if (err <= 0)
 897                 goto out_module_put;
 898
 899         nla_nest_end(skb, nest);
 900
 901         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 902         nlh->nlmsg_flags |= NLM_F_ROOT;
 903         module_put(ops->owner);
 904         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 905                              n->nlmsg_flags & NLM_F_ECHO);
 906         if (err > 0)
 907                 return 0;
 908
 909         return err;
 910
 911 out_module_put:
 912         module_put(ops->owner);
 913 err_out:
 914         kfree_skb(skb);
 915         return err;
 916 }
 917
 918 static int
 919 tcf_del_notify(struct net *net, struct nlmsghdr *n, struct list_head *actions,
 920                u32 portid)
 921 {
 922         int ret;
 923         struct sk_buff *skb;
 924
 925         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 926         if (!skb)
 927                 return -ENOBUFS;
 928
 929         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, RTM_DELACTION,
 930                          0, 1) <= 0) {
 931                 kfree_skb(skb);
 932                 return -EINVAL;
 933         }
 934
 935         /* now do the delete */
 936         ret = tcf_action_destroy(actions, 0);
 937         if (ret < 0) {
 938                 kfree_skb(skb);
 939                 return ret;
 940         }
 941
 942         ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
 943                              n->nlmsg_flags & NLM_F_ECHO);
 944         if (ret > 0)
 945                 return 0;
 946         return ret;
 947 }
 948
 949 static int
 950 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 951               u32 portid, int event)
 952 {
 953         int i, ret;
 954         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
 955         struct tc_action *act;
 956         LIST_HEAD(actions);
 957
 958         ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL, NULL);
 959         if (ret < 0)
 960                 return ret;
 961
 962         if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
 963                 if (tb[1] != NULL)
 964                         return tca_action_flush(net, tb[1], n, portid);
 965                 else
 966                         return -EINVAL;
 967         }
 968
 969         for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
 970                 act = tcf_action_get_1(net, tb[i], n, portid);
 971                 if (IS_ERR(act)) {
 972                         ret = PTR_ERR(act);
 973                         goto err;
 974                 }
 975                 act->order = i;
 976                 list_add_tail(&act->list, &actions);
 977         }
 978
 979         if (event == RTM_GETACTION)
 980                 ret = act_get_notify(net, portid, n, &actions, event);
 981         else { /* delete */
 982                 ret = tcf_del_notify(net, n, &actions, portid);
 983                 if (ret)
 984                         goto err;
 985                 return ret;
 986         }
 987 err:
 988         if (event != RTM_GETACTION)
 989                 tcf_action_destroy(&actions, 0);
 990         return ret;
 991 }
 992
 993 static int
 994 tcf_add_notify(struct net *net, struct nlmsghdr *n, struct list_head *actions,
 995                u32 portid)
 996 {
 997         struct sk_buff *skb;
 998         int err = 0;
 999
1000         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1001         if (!skb)
1002                 return -ENOBUFS;
1003
1004         if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, n->nlmsg_flags,
1005                          RTM_NEWACTION, 0, 0) <= 0) {
1006                 kfree_skb(skb);
1007                 return -EINVAL;
1008         }
1009
1010         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1011                              n->nlmsg_flags & NLM_F_ECHO);
1012         if (err > 0)
1013                 err = 0;
1014         return err;
1015 }
1016
1017 static int tcf_action_add(struct net *net, struct nlattr *nla,
1018                           struct nlmsghdr *n, u32 portid, int ovr)
1019 {
1020         int ret = 0;
1021         LIST_HEAD(actions);
1022
1023         ret = tcf_action_init(net, nla, NULL, NULL, ovr, 0, &actions);
1024         if (ret)
1025                 return ret;
1026
1027         return tcf_add_notify(net, n, &actions, portid);
1028 }
1029
1030 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n,
1031                          struct netlink_ext_ack *extack)
1032 {
1033         struct net *net = sock_net(skb->sk);
1034         struct nlattr *tca[TCA_ACT_MAX + 1];
1035         u32 portid = skb ? NETLINK_CB(skb).portid : 0;
1036         int ret = 0, ovr = 0;
1037
1038         if ((n->nlmsg_type != RTM_GETACTION) &&
1039             !netlink_capable(skb, CAP_NET_ADMIN))
1040                 return -EPERM;
1041
1042         ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ACT_MAX, NULL,
1043                           extack);
1044         if (ret < 0)
1045                 return ret;
1046
1047         if (tca[TCA_ACT_TAB] == NULL) {
1048                 pr_notice("tc_ctl_action: received NO action attribs\n");
1049                 return -EINVAL;
1050         }
1051
1052         /* n->nlmsg_flags & NLM_F_CREATE */
1053         switch (n->nlmsg_type) {
1054         case RTM_NEWACTION:
1055                 /* we are going to assume all other flags
1056                  * imply create only if it doesn't exist
1057                  * Note that CREATE | EXCL implies that
1058                  * but since we want avoid ambiguity (eg when flags
1059                  * is zero) then just set this
1060                  */
1061                 if (n->nlmsg_flags & NLM_F_REPLACE)
1062                         ovr = 1;
1063 replay:
1064                 ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, portid, ovr);
1065                 if (ret == -EAGAIN)
1066                         goto replay;
1067                 break;
1068         case RTM_DELACTION:
1069                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1070                                     portid, RTM_DELACTION);
1071                 break;
1072         case RTM_GETACTION:
1073                 ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1074                                     portid, RTM_GETACTION);
1075                 break;
1076         default:
1077                 BUG();
1078         }
1079
1080         return ret;
1081 }
1082
1083 static struct nlattr *find_dump_kind(const struct nlmsghdr *n)
1084 {
1085         struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
1086         struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1087         struct nlattr *nla[TCAA_MAX + 1];
1088         struct nlattr *kind;
1089
1090         if (nlmsg_parse(n, sizeof(struct tcamsg), nla, TCAA_MAX,
1091                         NULL, NULL) < 0)
1092                 return NULL;
1093         tb1 = nla[TCA_ACT_TAB];
1094         if (tb1 == NULL)
1095                 return NULL;
1096
1097         if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
1098                       NLMSG_ALIGN(nla_len(tb1)), NULL, NULL) < 0)
1099                 return NULL;
1100
1101         if (tb[1] == NULL)
1102                 return NULL;
1103         if (nla_parse_nested(tb2, TCA_ACT_MAX, tb[1], NULL, NULL) < 0)
1104                 return NULL;
1105         kind = tb2[TCA_ACT_KIND];
1106
1107         return kind;
1108 }
1109
1110 static int tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1111 {
1112         struct net *net = sock_net(skb->sk);
1113         struct nlmsghdr *nlh;
1114         unsigned char *b = skb_tail_pointer(skb);
1115         struct nlattr *nest;
1116         struct tc_action_ops *a_o;
1117         int ret = 0;
1118         struct tcamsg *t = (struct tcamsg *) nlmsg_data(cb->nlh);
1119         struct nlattr *kind = find_dump_kind(cb->nlh);
1120
1121         if (kind == NULL) {
1122                 pr_info("tc_dump_action: action bad kind\n");
1123                 return 0;
1124         }
1125
1126         a_o = tc_lookup_action(kind);
1127         if (a_o == NULL)
1128                 return 0;
1129
1130         nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
1131                         cb->nlh->nlmsg_type, sizeof(*t), 0);
1132         if (!nlh)
1133                 goto out_module_put;
1134         t = nlmsg_data(nlh);
1135         t->tca_family = AF_UNSPEC;
1136         t->tca__pad1 = 0;
1137         t->tca__pad2 = 0;
1138
1139         nest = nla_nest_start(skb, TCA_ACT_TAB);
1140         if (nest == NULL)
1141                 goto out_module_put;
1142
1143         ret = a_o->walk(net, skb, cb, RTM_GETACTION, a_o);
1144         if (ret < 0)
1145                 goto out_module_put;
1146
1147         if (ret > 0) {
1148                 nla_nest_end(skb, nest);
1149                 ret = skb->len;
1150         } else
1151                 nlmsg_trim(skb, b);
1152
1153         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1154         if (NETLINK_CB(cb->skb).portid && ret)
1155                 nlh->nlmsg_flags |= NLM_F_MULTI;
1156         module_put(a_o->owner);
1157         return skb->len;
1158
1159 out_module_put:
1160         module_put(a_o->owner);
1161         nlmsg_trim(skb, b);
1162         return skb->len;
1163 }
1164
1165 static int __init tc_action_init(void)
1166 {
1167         rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, NULL);
1168         rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, NULL);
1169         rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
1170                       NULL);
1171
1172         return 0;
1173 }
1174
1175 subsys_initcall(tc_action_init);