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 <asm/uaccess.h>
  15 #include <asm/system.h>
  16 #include <linux/bitops.h>
  17 #include <linux/config.h>
  18 #include <linux/types.h>
  19 #include <linux/kernel.h>
  20 #include <linux/sched.h>
  21 #include <linux/string.h>
  22 #include <linux/mm.h>
  23 #include <linux/socket.h>
  24 #include <linux/sockios.h>
  25 #include <linux/in.h>
  26 #include <linux/errno.h>
  27 #include <linux/interrupt.h>
  28 #include <linux/netdevice.h>
  29 #include <linux/skbuff.h>
  30 #include <linux/rtnetlink.h>
  31 #include <linux/init.h>
  32 #include <linux/kmod.h>
  33 #include <net/sock.h>
  34 #include <net/sch_generic.h>
  35 #include <net/act_api.h>
  36
  37 #if 1 /* control */
  38 #define DPRINTK(format, args...) printk(KERN_DEBUG format, ##args)
  39 #else
  40 #define DPRINTK(format, args...)
  41 #endif
  42 #if 0 /* data */
  43 #define D2PRINTK(format, args...) printk(KERN_DEBUG format, ##args)
  44 #else
  45 #define D2PRINTK(format, args...)
  46 #endif
  47
  48 static struct tc_action_ops *act_base = NULL;
  49 static DEFINE_RWLOCK(act_mod_lock);
  50
  51 int tcf_register_action(struct tc_action_ops *act)
  52 {
  53         struct tc_action_ops *a, **ap;
  54
  55         write_lock(&act_mod_lock);
  56         for (ap = &act_base; (a = *ap) != NULL; ap = &a->next) {
  57                 if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
  58                         write_unlock(&act_mod_lock);
  59                         return -EEXIST;
  60                 }
  61         }
  62         act->next = NULL;
  63         *ap = act;
  64         write_unlock(&act_mod_lock);
  65         return 0;
  66 }
  67
  68 int tcf_unregister_action(struct tc_action_ops *act)
  69 {
  70         struct tc_action_ops *a, **ap;
  71         int err = -ENOENT;
  72
  73         write_lock(&act_mod_lock);
  74         for (ap = &act_base; (a = *ap) != NULL; ap = &a->next)
  75                 if (a == act)
  76                         break;
  77         if (a) {
  78                 *ap = a->next;
  79                 a->next = NULL;
  80                 err = 0;
  81         }
  82         write_unlock(&act_mod_lock);
  83         return err;
  84 }
  85
  86 /* lookup by name */
  87 static struct tc_action_ops *tc_lookup_action_n(char *kind)
  88 {
  89         struct tc_action_ops *a = NULL;
  90
  91         if (kind) {
  92                 read_lock(&act_mod_lock);
  93                 for (a = act_base; a; a = a->next) {
  94                         if (strcmp(kind, a->kind) == 0) {
  95                                 if (!try_module_get(a->owner)) {
  96                                         read_unlock(&act_mod_lock);
  97                                         return NULL;
  98                                 }
  99                                 break;
 100                         }
 101                 }
 102                 read_unlock(&act_mod_lock);
 103         }
 104         return a;
 105 }
 106
 107 /* lookup by rtattr */
 108 static struct tc_action_ops *tc_lookup_action(struct rtattr *kind)
 109 {
 110         struct tc_action_ops *a = NULL;
 111
 112         if (kind) {
 113                 read_lock(&act_mod_lock);
 114                 for (a = act_base; a; a = a->next) {
 115                         if (rtattr_strcmp(kind, a->kind) == 0) {
 116                                 if (!try_module_get(a->owner)) {
 117                                         read_unlock(&act_mod_lock);
 118                                         return NULL;
 119                                 }
 120                                 break;
 121                         }
 122                 }
 123                 read_unlock(&act_mod_lock);
 124         }
 125         return a;
 126 }
 127
 128 #if 0
 129 /* lookup by id */
 130 static struct tc_action_ops *tc_lookup_action_id(u32 type)
 131 {
 132         struct tc_action_ops *a = NULL;
 133
 134         if (type) {
 135                 read_lock(&act_mod_lock);
 136                 for (a = act_base; a; a = a->next) {
 137                         if (a->type == type) {
 138                                 if (!try_module_get(a->owner)) {
 139                                         read_unlock(&act_mod_lock);
 140                                         return NULL;
 141                                 }
 142                                 break;
 143                         }
 144                 }
 145                 read_unlock(&act_mod_lock);
 146         }
 147         return a;
 148 }
 149 #endif
 150
 151 int tcf_action_exec(struct sk_buff *skb, struct tc_action *act,
 152                     struct tcf_result *res)
 153 {
 154         struct tc_action *a;
 155         int ret = -1;
 156
 157         if (skb->tc_verd & TC_NCLS) {
 158                 skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
 159                 D2PRINTK("(%p)tcf_action_exec: cleared TC_NCLS in %s out %s\n",
 160                          skb, skb->input_dev ? skb->input_dev->name : "xxx",
 161                          skb->dev->name);
 162                 ret = TC_ACT_OK;
 163                 goto exec_done;
 164         }
 165         while ((a = act) != NULL) {
 166 repeat:
 167                 if (a->ops && a->ops->act) {
 168                         ret = a->ops->act(&skb, a);
 169                         if (TC_MUNGED & skb->tc_verd) {
 170                                 /* copied already, allow trampling */
 171                                 skb->tc_verd = SET_TC_OK2MUNGE(skb->tc_verd);
 172                                 skb->tc_verd = CLR_TC_MUNGED(skb->tc_verd);
 173                         }
 174                         if (ret != TC_ACT_PIPE)
 175                                 goto exec_done;
 176                         if (ret == TC_ACT_REPEAT)
 177                                 goto repeat;    /* we need a ttl - JHS */
 178                 }
 179                 act = a->next;
 180         }
 181 exec_done:
 182         if (skb->tc_classid > 0) {
 183                 res->classid = skb->tc_classid;
 184                 res->class = 0;
 185                 skb->tc_classid = 0;
 186         }
 187         return ret;
 188 }
 189
 190 void tcf_action_destroy(struct tc_action *act, int bind)
 191 {
 192         struct tc_action *a;
 193
 194         for (a = act; a; a = act) {
 195                 if (a->ops && a->ops->cleanup) {
 196                         DPRINTK("tcf_action_destroy destroying %p next %p\n",
 197                                 a, a->next);
 198                         if (a->ops->cleanup(a, bind) == ACT_P_DELETED)
 199                                 module_put(a->ops->owner);
 200                         act = act->next;
 201                         kfree(a);
 202                 } else { /*FIXME: Remove later - catch insertion bugs*/
 203                         printk("tcf_action_destroy: BUG? destroying NULL ops\n");
 204                         act = act->next;
 205                         kfree(a);
 206                 }
 207         }
 208 }
 209
 210 int
 211 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 212 {
 213         int err = -EINVAL;
 214
 215         if (a->ops == NULL || a->ops->dump == NULL)
 216                 return err;
 217         return a->ops->dump(skb, a, bind, ref);
 218 }
 219
 220 int
 221 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 222 {
 223         int err = -EINVAL;
 224         unsigned char *b = skb->tail;
 225         struct rtattr *r;
 226
 227         if (a->ops == NULL || a->ops->dump == NULL)
 228                 return err;
 229
 230         RTA_PUT(skb, TCA_KIND, IFNAMSIZ, a->ops->kind);
 231         if (tcf_action_copy_stats(skb, a, 0))
 232                 goto rtattr_failure;
 233         r = (struct rtattr*) skb->tail;
 234         RTA_PUT(skb, TCA_OPTIONS, 0, NULL);
 235         if ((err = tcf_action_dump_old(skb, a, bind, ref)) > 0) {
 236                 r->rta_len = skb->tail - (u8*)r;
 237                 return err;
 238         }
 239
 240 rtattr_failure:
 241         skb_trim(skb, b - skb->data);
 242         return -1;
 243 }
 244
 245 int
 246 tcf_action_dump(struct sk_buff *skb, struct tc_action *act, int bind, int ref)
 247 {
 248         struct tc_action *a;
 249         int err = -EINVAL;
 250         unsigned char *b = skb->tail;
 251         struct rtattr *r ;
 252
 253         while ((a = act) != NULL) {
 254                 r = (struct rtattr*) skb->tail;
 255                 act = a->next;
 256                 RTA_PUT(skb, a->order, 0, NULL);
 257                 err = tcf_action_dump_1(skb, a, bind, ref);
 258                 if (err < 0)
 259                         goto rtattr_failure;
 260                 r->rta_len = skb->tail - (u8*)r;
 261         }
 262
 263         return 0;
 264
 265 rtattr_failure:
 266         skb_trim(skb, b - skb->data);
 267         return -err;
 268 }
 269
 270 struct tc_action *tcf_action_init_1(struct rtattr *rta, struct rtattr *est,
 271                                     char *name, int ovr, int bind, int *err)
 272 {
 273         struct tc_action *a;
 274         struct tc_action_ops *a_o;
 275         char act_name[IFNAMSIZ];
 276         struct rtattr *tb[TCA_ACT_MAX+1];
 277         struct rtattr *kind;
 278
 279         *err = -EINVAL;
 280
 281         if (name == NULL) {
 282                 if (rtattr_parse_nested(tb, TCA_ACT_MAX, rta) < 0)
 283                         goto err_out;
 284                 kind = tb[TCA_ACT_KIND-1];
 285                 if (kind == NULL)
 286                         goto err_out;
 287                 if (rtattr_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
 288                         goto err_out;
 289         } else {
 290                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
 291                         goto err_out;
 292         }
 293
 294         a_o = tc_lookup_action_n(act_name);
 295         if (a_o == NULL) {
 296 #ifdef CONFIG_KMOD
 297                 rtnl_unlock();
 298                 request_module(act_name);
 299                 rtnl_lock();
 300
 301                 a_o = tc_lookup_action_n(act_name);
 302
 303                 /* We dropped the RTNL semaphore in order to
 304                  * perform the module load.  So, even if we
 305                  * succeeded in loading the module we have to
 306                  * tell the caller to replay the request.  We
 307                  * indicate this using -EAGAIN.
 308                  */
 309                 if (a_o != NULL) {
 310                         *err = -EAGAIN;
 311                         goto err_mod;
 312                 }
 313 #endif
 314                 goto err_out;
 315         }
 316
 317         *err = -ENOMEM;
 318         a = kmalloc(sizeof(*a), GFP_KERNEL);
 319         if (a == NULL)
 320                 goto err_mod;
 321         memset(a, 0, sizeof(*a));
 322
 323         /* backward compatibility for policer */
 324         if (name == NULL)
 325                 *err = a_o->init(tb[TCA_ACT_OPTIONS-1], est, a, ovr, bind);
 326         else
 327                 *err = a_o->init(rta, est, a, ovr, bind);
 328         if (*err < 0)
 329                 goto err_free;
 330
 331         /* module count goes up only when brand new policy is created
 332            if it exists and is only bound to in a_o->init() then
 333            ACT_P_CREATED is not returned (a zero is).
 334         */
 335         if (*err != ACT_P_CREATED)
 336                 module_put(a_o->owner);
 337         a->ops = a_o;
 338         DPRINTK("tcf_action_init_1: successfull %s\n", act_name);
 339
 340         *err = 0;
 341         return a;
 342
 343 err_free:
 344         kfree(a);
 345 err_mod:
 346         module_put(a_o->owner);
 347 err_out:
 348         return NULL;
 349 }
 350
 351 struct tc_action *tcf_action_init(struct rtattr *rta, struct rtattr *est,
 352                                   char *name, int ovr, int bind, int *err)
 353 {
 354         struct rtattr *tb[TCA_ACT_MAX_PRIO+1];
 355         struct tc_action *head = NULL, *act, *act_prev = NULL;
 356         int i;
 357
 358         if (rtattr_parse_nested(tb, TCA_ACT_MAX_PRIO, rta) < 0) {
 359                 *err = -EINVAL;
 360                 return head;
 361         }
 362
 363         for (i=0; i < TCA_ACT_MAX_PRIO && tb[i]; i++) {
 364                 act = tcf_action_init_1(tb[i], est, name, ovr, bind, err);
 365                 if (act == NULL)
 366                         goto err;
 367                 act->order = i+1;
 368
 369                 if (head == NULL)
 370                         head = act;
 371                 else
 372                         act_prev->next = act;
 373                 act_prev = act;
 374         }
 375         return head;
 376
 377 err:
 378         if (head != NULL)
 379                 tcf_action_destroy(head, bind);
 380         return NULL;
 381 }
 382
 383 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
 384                           int compat_mode)
 385 {
 386         int err = 0;
 387         struct gnet_dump d;
 388         struct tcf_act_hdr *h = a->priv;
 389
 390         if (h == NULL)
 391                 goto errout;
 392
 393         /* compat_mode being true specifies a call that is supposed
 394          * to add additional backward compatiblity statistic TLVs.
 395          */
 396         if (compat_mode) {
 397                 if (a->type == TCA_OLD_COMPAT)
 398                         err = gnet_stats_start_copy_compat(skb, 0,
 399                                 TCA_STATS, TCA_XSTATS, h->stats_lock, &d);
 400                 else
 401                         return 0;
 402         } else
 403                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
 404                         h->stats_lock, &d);
 405
 406         if (err < 0)
 407                 goto errout;
 408
 409         if (a->ops != NULL && a->ops->get_stats != NULL)
 410                 if (a->ops->get_stats(skb, a) < 0)
 411                         goto errout;
 412
 413         if (gnet_stats_copy_basic(&d, &h->bstats) < 0 ||
 414 #ifdef CONFIG_NET_ESTIMATOR
 415             gnet_stats_copy_rate_est(&d, &h->rate_est) < 0 ||
 416 #endif
 417             gnet_stats_copy_queue(&d, &h->qstats) < 0)
 418                 goto errout;
 419
 420         if (gnet_stats_finish_copy(&d) < 0)
 421                 goto errout;
 422
 423         return 0;
 424
 425 errout:
 426         return -1;
 427 }
 428
 429 static int
 430 tca_get_fill(struct sk_buff *skb, struct tc_action *a, u32 pid, u32 seq,
 431              unsigned flags, int event, int bind, int ref)
 432 {
 433         struct tcamsg *t;
 434         struct nlmsghdr *nlh;
 435         unsigned char *b = skb->tail;
 436         struct rtattr *x;
 437
 438         nlh = NLMSG_PUT(skb, pid, seq, event, sizeof(*t));
 439         nlh->nlmsg_flags = flags;
 440         t = NLMSG_DATA(nlh);
 441         t->tca_family = AF_UNSPEC;
 442
 443         x = (struct rtattr*) skb->tail;
 444         RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
 445
 446         if (tcf_action_dump(skb, a, bind, ref) < 0)
 447                 goto rtattr_failure;
 448
 449         x->rta_len = skb->tail - (u8*)x;
 450
 451         nlh->nlmsg_len = skb->tail - b;
 452         return skb->len;
 453
 454 rtattr_failure:
 455 nlmsg_failure:
 456         skb_trim(skb, b - skb->data);
 457         return -1;
 458 }
 459
 460 static int
 461 act_get_notify(u32 pid, struct nlmsghdr *n, struct tc_action *a, int event)
 462 {
 463         struct sk_buff *skb;
 464         int err = 0;
 465
 466         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 467         if (!skb)
 468                 return -ENOBUFS;
 469         if (tca_get_fill(skb, a, pid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
 470                 kfree_skb(skb);
 471                 return -EINVAL;
 472         }
 473         err = netlink_unicast(rtnl, skb, pid, MSG_DONTWAIT);
 474         if (err > 0)
 475                 err = 0;
 476         return err;
 477 }
 478
 479 static struct tc_action *
 480 tcf_action_get_1(struct rtattr *rta, struct nlmsghdr *n, u32 pid, int *err)
 481 {
 482         struct rtattr *tb[TCA_ACT_MAX+1];
 483         struct tc_action *a;
 484         int index;
 485
 486         *err = -EINVAL;
 487         if (rtattr_parse_nested(tb, TCA_ACT_MAX, rta) < 0)
 488                 return NULL;
 489
 490         if (tb[TCA_ACT_INDEX - 1] == NULL ||
 491             RTA_PAYLOAD(tb[TCA_ACT_INDEX - 1]) < sizeof(index))
 492                 return NULL;
 493         index = *(int *)RTA_DATA(tb[TCA_ACT_INDEX - 1]);
 494
 495         *err = -ENOMEM;
 496         a = kmalloc(sizeof(struct tc_action), GFP_KERNEL);
 497         if (a == NULL)
 498                 return NULL;
 499         memset(a, 0, sizeof(struct tc_action));
 500
 501         *err = -EINVAL;
 502         a->ops = tc_lookup_action(tb[TCA_ACT_KIND - 1]);
 503         if (a->ops == NULL)
 504                 goto err_free;
 505         if (a->ops->lookup == NULL)
 506                 goto err_mod;
 507         *err = -ENOENT;
 508         if (a->ops->lookup(a, index) == 0)
 509                 goto err_mod;
 510
 511         module_put(a->ops->owner);
 512         *err = 0;
 513         return a;
 514 err_mod:
 515         module_put(a->ops->owner);
 516 err_free:
 517         kfree(a);
 518         return NULL;
 519 }
 520
 521 static void cleanup_a(struct tc_action *act)
 522 {
 523         struct tc_action *a;
 524
 525         for (a = act; a; a = act) {
 526                 act = a->next;
 527                 kfree(a);
 528         }
 529 }
 530
 531 static struct tc_action *create_a(int i)
 532 {
 533         struct tc_action *act;
 534
 535         act = kmalloc(sizeof(*act), GFP_KERNEL);
 536         if (act == NULL) {
 537                 printk("create_a: failed to alloc!\n");
 538                 return NULL;
 539         }
 540         memset(act, 0, sizeof(*act));
 541         act->order = i;
 542         return act;
 543 }
 544
 545 static int tca_action_flush(struct rtattr *rta, struct nlmsghdr *n, u32 pid)
 546 {
 547         struct sk_buff *skb;
 548         unsigned char *b;
 549         struct nlmsghdr *nlh;
 550         struct tcamsg *t;
 551         struct netlink_callback dcb;
 552         struct rtattr *x;
 553         struct rtattr *tb[TCA_ACT_MAX+1];
 554         struct rtattr *kind;
 555         struct tc_action *a = create_a(0);
 556         int err = -EINVAL;
 557
 558         if (a == NULL) {
 559                 printk("tca_action_flush: couldnt create tc_action\n");
 560                 return err;
 561         }
 562
 563         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 564         if (!skb) {
 565                 printk("tca_action_flush: failed skb alloc\n");
 566                 kfree(a);
 567                 return -ENOBUFS;
 568         }
 569
 570         b = (unsigned char *)skb->tail;
 571
 572         if (rtattr_parse_nested(tb, TCA_ACT_MAX, rta) < 0)
 573                 goto err_out;
 574
 575         kind = tb[TCA_ACT_KIND-1];
 576         a->ops = tc_lookup_action(kind);
 577         if (a->ops == NULL)
 578                 goto err_out;
 579
 580         nlh = NLMSG_PUT(skb, pid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t));
 581         t = NLMSG_DATA(nlh);
 582         t->tca_family = AF_UNSPEC;
 583
 584         x = (struct rtattr *) skb->tail;
 585         RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
 586
 587         err = a->ops->walk(skb, &dcb, RTM_DELACTION, a);
 588         if (err < 0)
 589                 goto rtattr_failure;
 590
 591         x->rta_len = skb->tail - (u8 *) x;
 592
 593         nlh->nlmsg_len = skb->tail - b;
 594         nlh->nlmsg_flags |= NLM_F_ROOT;
 595         module_put(a->ops->owner);
 596         kfree(a);
 597         err = rtnetlink_send(skb, pid, RTMGRP_TC, n->nlmsg_flags&NLM_F_ECHO);
 598         if (err > 0)
 599                 return 0;
 600
 601         return err;
 602
 603 rtattr_failure:
 604         module_put(a->ops->owner);
 605 nlmsg_failure:
 606 err_out:
 607         kfree_skb(skb);
 608         kfree(a);
 609         return err;
 610 }
 611
 612 static int
 613 tca_action_gd(struct rtattr *rta, struct nlmsghdr *n, u32 pid, int event)
 614 {
 615         int i, ret = 0;
 616         struct rtattr *tb[TCA_ACT_MAX_PRIO+1];
 617         struct tc_action *head = NULL, *act, *act_prev = NULL;
 618
 619         if (rtattr_parse_nested(tb, TCA_ACT_MAX_PRIO, rta) < 0)
 620                 return -EINVAL;
 621
 622         if (event == RTM_DELACTION && n->nlmsg_flags&NLM_F_ROOT) {
 623                 if (tb[0] != NULL && tb[1] == NULL)
 624                         return tca_action_flush(tb[0], n, pid);
 625         }
 626
 627         for (i=0; i < TCA_ACT_MAX_PRIO && tb[i]; i++) {
 628                 act = tcf_action_get_1(tb[i], n, pid, &ret);
 629                 if (act == NULL)
 630                         goto err;
 631                 act->order = i+1;
 632
 633                 if (head == NULL)
 634                         head = act;
 635                 else
 636                         act_prev->next = act;
 637                 act_prev = act;
 638         }
 639
 640         if (event == RTM_GETACTION)
 641                 ret = act_get_notify(pid, n, head, event);
 642         else { /* delete */
 643                 struct sk_buff *skb;
 644
 645                 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 646                 if (!skb) {
 647                         ret = -ENOBUFS;
 648                         goto err;
 649                 }
 650
 651                 if (tca_get_fill(skb, head, pid, n->nlmsg_seq, 0, event,
 652                                  0, 1) <= 0) {
 653                         kfree_skb(skb);
 654                         ret = -EINVAL;
 655                         goto err;
 656                 }
 657
 658                 /* now do the delete */
 659                 tcf_action_destroy(head, 0);
 660                 ret = rtnetlink_send(skb, pid, RTMGRP_TC,
 661                                      n->nlmsg_flags&NLM_F_ECHO);
 662                 if (ret > 0)
 663                         return 0;
 664                 return ret;
 665         }
 666 err:
 667         cleanup_a(head);
 668         return ret;
 669 }
 670
 671 static int tcf_add_notify(struct tc_action *a, u32 pid, u32 seq, int event,
 672                           unsigned flags)
 673 {
 674         struct tcamsg *t;
 675         struct nlmsghdr *nlh;
 676         struct sk_buff *skb;
 677         struct rtattr *x;
 678         unsigned char *b;
 679         int err = 0;
 680
 681         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 682         if (!skb)
 683                 return -ENOBUFS;
 684
 685         b = (unsigned char *)skb->tail;
 686
 687         nlh = NLMSG_PUT(skb, pid, seq, event, sizeof(*t));
 688         nlh->nlmsg_flags = flags;
 689         t = NLMSG_DATA(nlh);
 690         t->tca_family = AF_UNSPEC;
 691
 692         x = (struct rtattr*) skb->tail;
 693         RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
 694
 695         if (tcf_action_dump(skb, a, 0, 0) < 0)
 696                 goto rtattr_failure;
 697
 698         x->rta_len = skb->tail - (u8*)x;
 699
 700         nlh->nlmsg_len = skb->tail - b;
 701         NETLINK_CB(skb).dst_groups = RTMGRP_TC;
 702
 703         err = rtnetlink_send(skb, pid, RTMGRP_TC, flags&NLM_F_ECHO);
 704         if (err > 0)
 705                 err = 0;
 706         return err;
 707
 708 rtattr_failure:
 709 nlmsg_failure:
 710         skb_trim(skb, b - skb->data);
 711         return -1;
 712 }
 713
 714
 715 static int
 716 tcf_action_add(struct rtattr *rta, struct nlmsghdr *n, u32 pid, int ovr)
 717 {
 718         int ret = 0;
 719         struct tc_action *act;
 720         struct tc_action *a;
 721         u32 seq = n->nlmsg_seq;
 722
 723         act = tcf_action_init(rta, NULL, NULL, ovr, 0, &ret);
 724         if (act == NULL)
 725                 goto done;
 726
 727         /* dump then free all the actions after update; inserted policy
 728          * stays intact
 729          * */
 730         ret = tcf_add_notify(act, pid, seq, RTM_NEWACTION, n->nlmsg_flags);
 731         for (a = act; a; a = act) {
 732                 act = a->next;
 733                 kfree(a);
 734         }
 735 done:
 736         return ret;
 737 }
 738
 739 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
 740 {
 741         struct rtattr **tca = arg;
 742         u32 pid = skb ? NETLINK_CB(skb).pid : 0;
 743         int ret = 0, ovr = 0;
 744
 745         if (tca[TCA_ACT_TAB-1] == NULL) {
 746                 printk("tc_ctl_action: received NO action attribs\n");
 747                 return -EINVAL;
 748         }
 749
 750         /* n->nlmsg_flags&NLM_F_CREATE
 751          * */
 752         switch (n->nlmsg_type) {
 753         case RTM_NEWACTION:
 754                 /* we are going to assume all other flags
 755                  * imply create only if it doesnt exist
 756                  * Note that CREATE | EXCL implies that
 757                  * but since we want avoid ambiguity (eg when flags
 758                  * is zero) then just set this
 759                  */
 760                 if (n->nlmsg_flags&NLM_F_REPLACE)
 761                         ovr = 1;
 762 replay:
 763                 ret = tcf_action_add(tca[TCA_ACT_TAB-1], n, pid, ovr);
 764                 if (ret == -EAGAIN)
 765                         goto replay;
 766                 break;
 767         case RTM_DELACTION:
 768                 ret = tca_action_gd(tca[TCA_ACT_TAB-1], n, pid, RTM_DELACTION);
 769                 break;
 770         case RTM_GETACTION:
 771                 ret = tca_action_gd(tca[TCA_ACT_TAB-1], n, pid, RTM_GETACTION);
 772                 break;
 773         default:
 774                 BUG();
 775         }
 776
 777         return ret;
 778 }
 779
 780 static char *
 781 find_dump_kind(struct nlmsghdr *n)
 782 {
 783         struct rtattr *tb1, *tb2[TCA_ACT_MAX+1];
 784         struct rtattr *tb[TCA_ACT_MAX_PRIO + 1];
 785         struct rtattr *rta[TCAA_MAX + 1];
 786         struct rtattr *kind;
 787         int min_len = NLMSG_LENGTH(sizeof(struct tcamsg));
 788         int attrlen = n->nlmsg_len - NLMSG_ALIGN(min_len);
 789         struct rtattr *attr = (void *) n + NLMSG_ALIGN(min_len);
 790
 791         if (rtattr_parse(rta, TCAA_MAX, attr, attrlen) < 0)
 792                 return NULL;
 793         tb1 = rta[TCA_ACT_TAB - 1];
 794         if (tb1 == NULL)
 795                 return NULL;
 796
 797         if (rtattr_parse(tb, TCA_ACT_MAX_PRIO, RTA_DATA(tb1),
 798                          NLMSG_ALIGN(RTA_PAYLOAD(tb1))) < 0)
 799                 return NULL;
 800         if (tb[0] == NULL)
 801                 return NULL;
 802
 803         if (rtattr_parse(tb2, TCA_ACT_MAX, RTA_DATA(tb[0]),
 804                          RTA_PAYLOAD(tb[0])) < 0)
 805                 return NULL;
 806         kind = tb2[TCA_ACT_KIND-1];
 807
 808         return (char *) RTA_DATA(kind);
 809 }
 810
 811 static int
 812 tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
 813 {
 814         struct nlmsghdr *nlh;
 815         unsigned char *b = skb->tail;
 816         struct rtattr *x;
 817         struct tc_action_ops *a_o;
 818         struct tc_action a;
 819         int ret = 0;
 820         struct tcamsg *t = (struct tcamsg *) NLMSG_DATA(cb->nlh);
 821         char *kind = find_dump_kind(cb->nlh);
 822
 823         if (kind == NULL) {
 824                 printk("tc_dump_action: action bad kind\n");
 825                 return 0;
 826         }
 827
 828         a_o = tc_lookup_action_n(kind);
 829         if (a_o == NULL) {
 830                 printk("failed to find %s\n", kind);
 831                 return 0;
 832         }
 833
 834         memset(&a, 0, sizeof(struct tc_action));
 835         a.ops = a_o;
 836
 837         if (a_o->walk == NULL) {
 838                 printk("tc_dump_action: %s !capable of dumping table\n", kind);
 839                 goto rtattr_failure;
 840         }
 841
 842         nlh = NLMSG_PUT(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
 843                         cb->nlh->nlmsg_type, sizeof(*t));
 844         t = NLMSG_DATA(nlh);
 845         t->tca_family = AF_UNSPEC;
 846
 847         x = (struct rtattr *) skb->tail;
 848         RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
 849
 850         ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
 851         if (ret < 0)
 852                 goto rtattr_failure;
 853
 854         if (ret > 0) {
 855                 x->rta_len = skb->tail - (u8 *) x;
 856                 ret = skb->len;
 857         } else
 858                 skb_trim(skb, (u8*)x - skb->data);
 859
 860         nlh->nlmsg_len = skb->tail - b;
 861         if (NETLINK_CB(cb->skb).pid && ret)
 862                 nlh->nlmsg_flags |= NLM_F_MULTI;
 863         module_put(a_o->owner);
 864         return skb->len;
 865
 866 rtattr_failure:
 867 nlmsg_failure:
 868         module_put(a_o->owner);
 869         skb_trim(skb, b - skb->data);
 870         return skb->len;
 871 }
 872
 873 static int __init tc_action_init(void)
 874 {
 875         struct rtnetlink_link *link_p = rtnetlink_links[PF_UNSPEC];
 876
 877         if (link_p) {
 878                 link_p[RTM_NEWACTION-RTM_BASE].doit = tc_ctl_action;
 879                 link_p[RTM_DELACTION-RTM_BASE].doit = tc_ctl_action;
 880                 link_p[RTM_GETACTION-RTM_BASE].doit = tc_ctl_action;
 881                 link_p[RTM_GETACTION-RTM_BASE].dumpit = tc_dump_action;
 882         }
 883
 884         printk("TC classifier action (bugs to netdev@oss.sgi.com cc "
 885                "hadi@cyberus.ca)\n");
 886         return 0;
 887 }
 888
 889 subsys_initcall(tc_action_init);
 890
 891 EXPORT_SYMBOL(tcf_register_action);
 892 EXPORT_SYMBOL(tcf_unregister_action);
 893 EXPORT_SYMBOL(tcf_action_exec);
 894 EXPORT_SYMBOL(tcf_action_dump_1);