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 0 /* 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, res);
 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_REPEAT)
 175                                 goto repeat;    /* we need a ttl - JHS */
 176                         if (ret != TC_ACT_PIPE)
 177                                 goto exec_done;
 178                 }
 179                 act = a->next;
 180         }
 181 exec_done:
 182         return ret;
 183 }
 184
 185 void tcf_action_destroy(struct tc_action *act, int bind)
 186 {
 187         struct tc_action *a;
 188
 189         for (a = act; a; a = act) {
 190                 if (a->ops && a->ops->cleanup) {
 191                         DPRINTK("tcf_action_destroy destroying %p next %p\n",
 192                                 a, a->next);
 193                         if (a->ops->cleanup(a, bind) == ACT_P_DELETED)
 194                                 module_put(a->ops->owner);
 195                         act = act->next;
 196                         kfree(a);
 197                 } else { /*FIXME: Remove later - catch insertion bugs*/
 198                         printk("tcf_action_destroy: BUG? destroying NULL ops\n");
 199                         act = act->next;
 200                         kfree(a);
 201                 }
 202         }
 203 }
 204
 205 int
 206 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 207 {
 208         int err = -EINVAL;
 209
 210         if (a->ops == NULL || a->ops->dump == NULL)
 211                 return err;
 212         return a->ops->dump(skb, a, bind, ref);
 213 }
 214
 215 int
 216 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 217 {
 218         int err = -EINVAL;
 219         unsigned char *b = skb->tail;
 220         struct rtattr *r;
 221
 222         if (a->ops == NULL || a->ops->dump == NULL)
 223                 return err;
 224
 225         RTA_PUT(skb, TCA_KIND, IFNAMSIZ, a->ops->kind);
 226         if (tcf_action_copy_stats(skb, a, 0))
 227                 goto rtattr_failure;
 228         r = (struct rtattr*) skb->tail;
 229         RTA_PUT(skb, TCA_OPTIONS, 0, NULL);
 230         if ((err = tcf_action_dump_old(skb, a, bind, ref)) > 0) {
 231                 r->rta_len = skb->tail - (u8*)r;
 232                 return err;
 233         }
 234
 235 rtattr_failure:
 236         skb_trim(skb, b - skb->data);
 237         return -1;
 238 }
 239
 240 int
 241 tcf_action_dump(struct sk_buff *skb, struct tc_action *act, int bind, int ref)
 242 {
 243         struct tc_action *a;
 244         int err = -EINVAL;
 245         unsigned char *b = skb->tail;
 246         struct rtattr *r ;
 247
 248         while ((a = act) != NULL) {
 249                 r = (struct rtattr*) skb->tail;
 250                 act = a->next;
 251                 RTA_PUT(skb, a->order, 0, NULL);
 252                 err = tcf_action_dump_1(skb, a, bind, ref);
 253                 if (err < 0)
 254                         goto rtattr_failure;
 255                 r->rta_len = skb->tail - (u8*)r;
 256         }
 257
 258         return 0;
 259
 260 rtattr_failure:
 261         skb_trim(skb, b - skb->data);
 262         return -err;
 263 }
 264
 265 struct tc_action *tcf_action_init_1(struct rtattr *rta, struct rtattr *est,
 266                                     char *name, int ovr, int bind, int *err)
 267 {
 268         struct tc_action *a;
 269         struct tc_action_ops *a_o;
 270         char act_name[IFNAMSIZ];
 271         struct rtattr *tb[TCA_ACT_MAX+1];
 272         struct rtattr *kind;
 273
 274         *err = -EINVAL;
 275
 276         if (name == NULL) {
 277                 if (rtattr_parse_nested(tb, TCA_ACT_MAX, rta) < 0)
 278                         goto err_out;
 279                 kind = tb[TCA_ACT_KIND-1];
 280                 if (kind == NULL)
 281                         goto err_out;
 282                 if (rtattr_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
 283                         goto err_out;
 284         } else {
 285                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
 286                         goto err_out;
 287         }
 288
 289         a_o = tc_lookup_action_n(act_name);
 290         if (a_o == NULL) {
 291 #ifdef CONFIG_KMOD
 292                 rtnl_unlock();
 293                 request_module("act_%s", act_name);
 294                 rtnl_lock();
 295
 296                 a_o = tc_lookup_action_n(act_name);
 297
 298                 /* We dropped the RTNL semaphore in order to
 299                  * perform the module load.  So, even if we
 300                  * succeeded in loading the module we have to
 301                  * tell the caller to replay the request.  We
 302                  * indicate this using -EAGAIN.
 303                  */
 304                 if (a_o != NULL) {
 305                         *err = -EAGAIN;
 306                         goto err_mod;
 307                 }
 308 #endif
 309                 goto err_out;
 310         }
 311
 312         *err = -ENOMEM;
 313         a = kmalloc(sizeof(*a), GFP_KERNEL);
 314         if (a == NULL)
 315                 goto err_mod;
 316         memset(a, 0, sizeof(*a));
 317
 318         /* backward compatibility for policer */
 319         if (name == NULL)
 320                 *err = a_o->init(tb[TCA_ACT_OPTIONS-1], est, a, ovr, bind);
 321         else
 322                 *err = a_o->init(rta, est, a, ovr, bind);
 323         if (*err < 0)
 324                 goto err_free;
 325
 326         /* module count goes up only when brand new policy is created
 327            if it exists and is only bound to in a_o->init() then
 328            ACT_P_CREATED is not returned (a zero is).
 329         */
 330         if (*err != ACT_P_CREATED)
 331                 module_put(a_o->owner);
 332         a->ops = a_o;
 333         DPRINTK("tcf_action_init_1: successfull %s\n", act_name);
 334
 335         *err = 0;
 336         return a;
 337
 338 err_free:
 339         kfree(a);
 340 err_mod:
 341         module_put(a_o->owner);
 342 err_out:
 343         return NULL;
 344 }
 345
 346 struct tc_action *tcf_action_init(struct rtattr *rta, struct rtattr *est,
 347                                   char *name, int ovr, int bind, int *err)
 348 {
 349         struct rtattr *tb[TCA_ACT_MAX_PRIO+1];
 350         struct tc_action *head = NULL, *act, *act_prev = NULL;
 351         int i;
 352
 353         if (rtattr_parse_nested(tb, TCA_ACT_MAX_PRIO, rta) < 0) {
 354                 *err = -EINVAL;
 355                 return head;
 356         }
 357
 358         for (i=0; i < TCA_ACT_MAX_PRIO && tb[i]; i++) {
 359                 act = tcf_action_init_1(tb[i], est, name, ovr, bind, err);
 360                 if (act == NULL)
 361                         goto err;
 362                 act->order = i+1;
 363
 364                 if (head == NULL)
 365                         head = act;
 366                 else
 367                         act_prev->next = act;
 368                 act_prev = act;
 369         }
 370         return head;
 371
 372 err:
 373         if (head != NULL)
 374                 tcf_action_destroy(head, bind);
 375         return NULL;
 376 }
 377
 378 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
 379                           int compat_mode)
 380 {
 381         int err = 0;
 382         struct gnet_dump d;
 383         struct tcf_act_hdr *h = a->priv;
 384
 385         if (h == NULL)
 386                 goto errout;
 387
 388         /* compat_mode being true specifies a call that is supposed
 389          * to add additional backward compatiblity statistic TLVs.
 390          */
 391         if (compat_mode) {
 392                 if (a->type == TCA_OLD_COMPAT)
 393                         err = gnet_stats_start_copy_compat(skb, 0,
 394                                 TCA_STATS, TCA_XSTATS, h->stats_lock, &d);
 395                 else
 396                         return 0;
 397         } else
 398                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
 399                         h->stats_lock, &d);
 400
 401         if (err < 0)
 402                 goto errout;
 403
 404         if (a->ops != NULL && a->ops->get_stats != NULL)
 405                 if (a->ops->get_stats(skb, a) < 0)
 406                         goto errout;
 407
 408         if (gnet_stats_copy_basic(&d, &h->bstats) < 0 ||
 409 #ifdef CONFIG_NET_ESTIMATOR
 410             gnet_stats_copy_rate_est(&d, &h->rate_est) < 0 ||
 411 #endif
 412             gnet_stats_copy_queue(&d, &h->qstats) < 0)
 413                 goto errout;
 414
 415         if (gnet_stats_finish_copy(&d) < 0)
 416                 goto errout;
 417
 418         return 0;
 419
 420 errout:
 421         return -1;
 422 }
 423
 424 static int
 425 tca_get_fill(struct sk_buff *skb, struct tc_action *a, u32 pid, u32 seq,
 426              u16 flags, int event, int bind, int ref)
 427 {
 428         struct tcamsg *t;
 429         struct nlmsghdr *nlh;
 430         unsigned char *b = skb->tail;
 431         struct rtattr *x;
 432
 433         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
 434
 435         t = NLMSG_DATA(nlh);
 436         t->tca_family = AF_UNSPEC;
 437         t->tca__pad1 = 0;
 438         t->tca__pad2 = 0;
 439
 440         x = (struct rtattr*) skb->tail;
 441         RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
 442
 443         if (tcf_action_dump(skb, a, bind, ref) < 0)
 444                 goto rtattr_failure;
 445
 446         x->rta_len = skb->tail - (u8*)x;
 447
 448         nlh->nlmsg_len = skb->tail - b;
 449         return skb->len;
 450
 451 rtattr_failure:
 452 nlmsg_failure:
 453         skb_trim(skb, b - skb->data);
 454         return -1;
 455 }
 456
 457 static int
 458 act_get_notify(u32 pid, struct nlmsghdr *n, struct tc_action *a, int event)
 459 {
 460         struct sk_buff *skb;
 461         int err = 0;
 462
 463         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 464         if (!skb)
 465                 return -ENOBUFS;
 466         if (tca_get_fill(skb, a, pid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
 467                 kfree_skb(skb);
 468                 return -EINVAL;
 469         }
 470         err = netlink_unicast(rtnl, skb, pid, MSG_DONTWAIT);
 471         if (err > 0)
 472                 err = 0;
 473         return err;
 474 }
 475
 476 static struct tc_action *
 477 tcf_action_get_1(struct rtattr *rta, struct nlmsghdr *n, u32 pid, int *err)
 478 {
 479         struct rtattr *tb[TCA_ACT_MAX+1];
 480         struct tc_action *a;
 481         int index;
 482
 483         *err = -EINVAL;
 484         if (rtattr_parse_nested(tb, TCA_ACT_MAX, rta) < 0)
 485                 return NULL;
 486
 487         if (tb[TCA_ACT_INDEX - 1] == NULL ||
 488             RTA_PAYLOAD(tb[TCA_ACT_INDEX - 1]) < sizeof(index))
 489                 return NULL;
 490         index = *(int *)RTA_DATA(tb[TCA_ACT_INDEX - 1]);
 491
 492         *err = -ENOMEM;
 493         a = kmalloc(sizeof(struct tc_action), GFP_KERNEL);
 494         if (a == NULL)
 495                 return NULL;
 496         memset(a, 0, sizeof(struct tc_action));
 497
 498         *err = -EINVAL;
 499         a->ops = tc_lookup_action(tb[TCA_ACT_KIND - 1]);
 500         if (a->ops == NULL)
 501                 goto err_free;
 502         if (a->ops->lookup == NULL)
 503                 goto err_mod;
 504         *err = -ENOENT;
 505         if (a->ops->lookup(a, index) == 0)
 506                 goto err_mod;
 507
 508         module_put(a->ops->owner);
 509         *err = 0;
 510         return a;
 511 err_mod:
 512         module_put(a->ops->owner);
 513 err_free:
 514         kfree(a);
 515         return NULL;
 516 }
 517
 518 static void cleanup_a(struct tc_action *act)
 519 {
 520         struct tc_action *a;
 521
 522         for (a = act; a; a = act) {
 523                 act = a->next;
 524                 kfree(a);
 525         }
 526 }
 527
 528 static struct tc_action *create_a(int i)
 529 {
 530         struct tc_action *act;
 531
 532         act = kmalloc(sizeof(*act), GFP_KERNEL);
 533         if (act == NULL) {
 534                 printk("create_a: failed to alloc!\n");
 535                 return NULL;
 536         }
 537         memset(act, 0, sizeof(*act));
 538         act->order = i;
 539         return act;
 540 }
 541
 542 static int tca_action_flush(struct rtattr *rta, struct nlmsghdr *n, u32 pid)
 543 {
 544         struct sk_buff *skb;
 545         unsigned char *b;
 546         struct nlmsghdr *nlh;
 547         struct tcamsg *t;
 548         struct netlink_callback dcb;
 549         struct rtattr *x;
 550         struct rtattr *tb[TCA_ACT_MAX+1];
 551         struct rtattr *kind;
 552         struct tc_action *a = create_a(0);
 553         int err = -EINVAL;
 554
 555         if (a == NULL) {
 556                 printk("tca_action_flush: couldnt create tc_action\n");
 557                 return err;
 558         }
 559
 560         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 561         if (!skb) {
 562                 printk("tca_action_flush: failed skb alloc\n");
 563                 kfree(a);
 564                 return -ENOBUFS;
 565         }
 566
 567         b = (unsigned char *)skb->tail;
 568
 569         if (rtattr_parse_nested(tb, TCA_ACT_MAX, rta) < 0)
 570                 goto err_out;
 571
 572         kind = tb[TCA_ACT_KIND-1];
 573         a->ops = tc_lookup_action(kind);
 574         if (a->ops == NULL)
 575                 goto err_out;
 576
 577         nlh = NLMSG_PUT(skb, pid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t));
 578         t = NLMSG_DATA(nlh);
 579         t->tca_family = AF_UNSPEC;
 580         t->tca__pad1 = 0;
 581         t->tca__pad2 = 0;
 582
 583         x = (struct rtattr *) skb->tail;
 584         RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
 585
 586         err = a->ops->walk(skb, &dcb, RTM_DELACTION, a);
 587         if (err < 0)
 588                 goto rtattr_failure;
 589
 590         x->rta_len = skb->tail - (u8 *) x;
 591
 592         nlh->nlmsg_len = skb->tail - b;
 593         nlh->nlmsg_flags |= NLM_F_ROOT;
 594         module_put(a->ops->owner);
 595         kfree(a);
 596         err = rtnetlink_send(skb, pid, RTNLGRP_TC, n->nlmsg_flags&NLM_F_ECHO);
 597         if (err > 0)
 598                 return 0;
 599
 600         return err;
 601
 602 rtattr_failure:
 603         module_put(a->ops->owner);
 604 nlmsg_failure:
 605 err_out:
 606         kfree_skb(skb);
 607         kfree(a);
 608         return err;
 609 }
 610
 611 static int
 612 tca_action_gd(struct rtattr *rta, struct nlmsghdr *n, u32 pid, int event)
 613 {
 614         int i, ret = 0;
 615         struct rtattr *tb[TCA_ACT_MAX_PRIO+1];
 616         struct tc_action *head = NULL, *act, *act_prev = NULL;
 617
 618         if (rtattr_parse_nested(tb, TCA_ACT_MAX_PRIO, rta) < 0)
 619                 return -EINVAL;
 620
 621         if (event == RTM_DELACTION && n->nlmsg_flags&NLM_F_ROOT) {
 622                 if (tb[0] != NULL && tb[1] == NULL)
 623                         return tca_action_flush(tb[0], n, pid);
 624         }
 625
 626         for (i=0; i < TCA_ACT_MAX_PRIO && tb[i]; i++) {
 627                 act = tcf_action_get_1(tb[i], n, pid, &ret);
 628                 if (act == NULL)
 629                         goto err;
 630                 act->order = i+1;
 631
 632                 if (head == NULL)
 633                         head = act;
 634                 else
 635                         act_prev->next = act;
 636                 act_prev = act;
 637         }
 638
 639         if (event == RTM_GETACTION)
 640                 ret = act_get_notify(pid, n, head, event);
 641         else { /* delete */
 642                 struct sk_buff *skb;
 643
 644                 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 645                 if (!skb) {
 646                         ret = -ENOBUFS;
 647                         goto err;
 648                 }
 649
 650                 if (tca_get_fill(skb, head, pid, n->nlmsg_seq, 0, event,
 651                                  0, 1) <= 0) {
 652                         kfree_skb(skb);
 653                         ret = -EINVAL;
 654                         goto err;
 655                 }
 656
 657                 /* now do the delete */
 658                 tcf_action_destroy(head, 0);
 659                 ret = rtnetlink_send(skb, pid, RTNLGRP_TC,
 660                                      n->nlmsg_flags&NLM_F_ECHO);
 661                 if (ret > 0)
 662                         return 0;
 663                 return ret;
 664         }
 665 err:
 666         cleanup_a(head);
 667         return ret;
 668 }
 669
 670 static int tcf_add_notify(struct tc_action *a, u32 pid, u32 seq, int event,
 671                           u16 flags)
 672 {
 673         struct tcamsg *t;
 674         struct nlmsghdr *nlh;
 675         struct sk_buff *skb;
 676         struct rtattr *x;
 677         unsigned char *b;
 678         int err = 0;
 679
 680         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 681         if (!skb)
 682                 return -ENOBUFS;
 683
 684         b = (unsigned char *)skb->tail;
 685
 686         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
 687         t = NLMSG_DATA(nlh);
 688         t->tca_family = AF_UNSPEC;
 689         t->tca__pad1 = 0;
 690         t->tca__pad2 = 0;
 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_group = RTNLGRP_TC;
 702
 703         err = rtnetlink_send(skb, pid, RTNLGRP_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         t->tca__pad1 = 0;
 847         t->tca__pad2 = 0;
 848
 849         x = (struct rtattr *) skb->tail;
 850         RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
 851
 852         ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
 853         if (ret < 0)
 854                 goto rtattr_failure;
 855
 856         if (ret > 0) {
 857                 x->rta_len = skb->tail - (u8 *) x;
 858                 ret = skb->len;
 859         } else
 860                 skb_trim(skb, (u8*)x - skb->data);
 861
 862         nlh->nlmsg_len = skb->tail - b;
 863         if (NETLINK_CB(cb->skb).pid && ret)
 864                 nlh->nlmsg_flags |= NLM_F_MULTI;
 865         module_put(a_o->owner);
 866         return skb->len;
 867
 868 rtattr_failure:
 869 nlmsg_failure:
 870         module_put(a_o->owner);
 871         skb_trim(skb, b - skb->data);
 872         return skb->len;
 873 }
 874
 875 static int __init tc_action_init(void)
 876 {
 877         struct rtnetlink_link *link_p = rtnetlink_links[PF_UNSPEC];
 878
 879         if (link_p) {
 880                 link_p[RTM_NEWACTION-RTM_BASE].doit = tc_ctl_action;
 881                 link_p[RTM_DELACTION-RTM_BASE].doit = tc_ctl_action;
 882                 link_p[RTM_GETACTION-RTM_BASE].doit = tc_ctl_action;
 883                 link_p[RTM_GETACTION-RTM_BASE].dumpit = tc_dump_action;
 884         }
 885
 886         printk("TC classifier action (bugs to netdev@vger.kernel.org cc "
 887                "hadi@cyberus.ca)\n");
 888         return 0;
 889 }
 890
 891 subsys_initcall(tc_action_init);
 892
 893 EXPORT_SYMBOL(tcf_register_action);
 894 EXPORT_SYMBOL(tcf_unregister_action);
 895 EXPORT_SYMBOL(tcf_action_exec);
 896 EXPORT_SYMBOL(tcf_action_dump_1);