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 errout;
 255                 r->rta_len = skb->tail - (u8*)r;
 256         }
 257
 258         return 0;
 259
 260 rtattr_failure:
 261         err = -EINVAL;
 262 errout:
 263         skb_trim(skb, b - skb->data);
 264         return err;
 265 }
 266
 267 struct tc_action *tcf_action_init_1(struct rtattr *rta, struct rtattr *est,
 268                                     char *name, int ovr, int bind, int *err)
 269 {
 270         struct tc_action *a;
 271         struct tc_action_ops *a_o;
 272         char act_name[IFNAMSIZ];
 273         struct rtattr *tb[TCA_ACT_MAX+1];
 274         struct rtattr *kind;
 275
 276         *err = -EINVAL;
 277
 278         if (name == NULL) {
 279                 if (rtattr_parse_nested(tb, TCA_ACT_MAX, rta) < 0)
 280                         goto err_out;
 281                 kind = tb[TCA_ACT_KIND-1];
 282                 if (kind == NULL)
 283                         goto err_out;
 284                 if (rtattr_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
 285                         goto err_out;
 286         } else {
 287                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
 288                         goto err_out;
 289         }
 290
 291         a_o = tc_lookup_action_n(act_name);
 292         if (a_o == NULL) {
 293 #ifdef CONFIG_KMOD
 294                 rtnl_unlock();
 295                 request_module("act_%s", act_name);
 296                 rtnl_lock();
 297
 298                 a_o = tc_lookup_action_n(act_name);
 299
 300                 /* We dropped the RTNL semaphore in order to
 301                  * perform the module load.  So, even if we
 302                  * succeeded in loading the module we have to
 303                  * tell the caller to replay the request.  We
 304                  * indicate this using -EAGAIN.
 305                  */
 306                 if (a_o != NULL) {
 307                         *err = -EAGAIN;
 308                         goto err_mod;
 309                 }
 310 #endif
 311                 *err = -ENOENT;
 312                 goto err_out;
 313         }
 314
 315         *err = -ENOMEM;
 316         a = kmalloc(sizeof(*a), GFP_KERNEL);
 317         if (a == NULL)
 318                 goto err_mod;
 319         memset(a, 0, sizeof(*a));
 320
 321         /* backward compatibility for policer */
 322         if (name == NULL)
 323                 *err = a_o->init(tb[TCA_ACT_OPTIONS-1], est, a, ovr, bind);
 324         else
 325                 *err = a_o->init(rta, est, a, ovr, bind);
 326         if (*err < 0)
 327                 goto err_free;
 328
 329         /* module count goes up only when brand new policy is created
 330            if it exists and is only bound to in a_o->init() then
 331            ACT_P_CREATED is not returned (a zero is).
 332         */
 333         if (*err != ACT_P_CREATED)
 334                 module_put(a_o->owner);
 335         a->ops = a_o;
 336         DPRINTK("tcf_action_init_1: successfull %s\n", act_name);
 337
 338         *err = 0;
 339         return a;
 340
 341 err_free:
 342         kfree(a);
 343 err_mod:
 344         module_put(a_o->owner);
 345 err_out:
 346         return NULL;
 347 }
 348
 349 struct tc_action *tcf_action_init(struct rtattr *rta, struct rtattr *est,
 350                                   char *name, int ovr, int bind, int *err)
 351 {
 352         struct rtattr *tb[TCA_ACT_MAX_PRIO+1];
 353         struct tc_action *head = NULL, *act, *act_prev = NULL;
 354         int i;
 355
 356         if (rtattr_parse_nested(tb, TCA_ACT_MAX_PRIO, rta) < 0) {
 357                 *err = -EINVAL;
 358                 return head;
 359         }
 360
 361         for (i=0; i < TCA_ACT_MAX_PRIO && tb[i]; i++) {
 362                 act = tcf_action_init_1(tb[i], est, name, ovr, bind, err);
 363                 if (act == NULL)
 364                         goto err;
 365                 act->order = i+1;
 366
 367                 if (head == NULL)
 368                         head = act;
 369                 else
 370                         act_prev->next = act;
 371                 act_prev = act;
 372         }
 373         return head;
 374
 375 err:
 376         if (head != NULL)
 377                 tcf_action_destroy(head, bind);
 378         return NULL;
 379 }
 380
 381 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
 382                           int compat_mode)
 383 {
 384         int err = 0;
 385         struct gnet_dump d;
 386         struct tcf_act_hdr *h = a->priv;
 387
 388         if (h == NULL)
 389                 goto errout;
 390
 391         /* compat_mode being true specifies a call that is supposed
 392          * to add additional backward compatiblity statistic TLVs.
 393          */
 394         if (compat_mode) {
 395                 if (a->type == TCA_OLD_COMPAT)
 396                         err = gnet_stats_start_copy_compat(skb, 0,
 397                                 TCA_STATS, TCA_XSTATS, h->stats_lock, &d);
 398                 else
 399                         return 0;
 400         } else
 401                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
 402                         h->stats_lock, &d);
 403
 404         if (err < 0)
 405                 goto errout;
 406
 407         if (a->ops != NULL && a->ops->get_stats != NULL)
 408                 if (a->ops->get_stats(skb, a) < 0)
 409                         goto errout;
 410
 411         if (gnet_stats_copy_basic(&d, &h->bstats) < 0 ||
 412 #ifdef CONFIG_NET_ESTIMATOR
 413             gnet_stats_copy_rate_est(&d, &h->rate_est) < 0 ||
 414 #endif
 415             gnet_stats_copy_queue(&d, &h->qstats) < 0)
 416                 goto errout;
 417
 418         if (gnet_stats_finish_copy(&d) < 0)
 419                 goto errout;
 420
 421         return 0;
 422
 423 errout:
 424         return -1;
 425 }
 426
 427 static int
 428 tca_get_fill(struct sk_buff *skb, struct tc_action *a, u32 pid, u32 seq,
 429              u16 flags, int event, int bind, int ref)
 430 {
 431         struct tcamsg *t;
 432         struct nlmsghdr *nlh;
 433         unsigned char *b = skb->tail;
 434         struct rtattr *x;
 435
 436         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
 437
 438         t = NLMSG_DATA(nlh);
 439         t->tca_family = AF_UNSPEC;
 440         t->tca__pad1 = 0;
 441         t->tca__pad2 = 0;
 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         t->tca__pad1 = 0;
 584         t->tca__pad2 = 0;
 585
 586         x = (struct rtattr *) skb->tail;
 587         RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
 588
 589         err = a->ops->walk(skb, &dcb, RTM_DELACTION, a);
 590         if (err < 0)
 591                 goto rtattr_failure;
 592
 593         x->rta_len = skb->tail - (u8 *) x;
 594
 595         nlh->nlmsg_len = skb->tail - b;
 596         nlh->nlmsg_flags |= NLM_F_ROOT;
 597         module_put(a->ops->owner);
 598         kfree(a);
 599         err = rtnetlink_send(skb, pid, RTNLGRP_TC, n->nlmsg_flags&NLM_F_ECHO);
 600         if (err > 0)
 601                 return 0;
 602
 603         return err;
 604
 605 rtattr_failure:
 606 nlmsg_failure:
 607         module_put(a->ops->owner);
 608 err_out:
 609         kfree_skb(skb);
 610         kfree(a);
 611         return err;
 612 }
 613
 614 static int
 615 tca_action_gd(struct rtattr *rta, struct nlmsghdr *n, u32 pid, int event)
 616 {
 617         int i, ret = 0;
 618         struct rtattr *tb[TCA_ACT_MAX_PRIO+1];
 619         struct tc_action *head = NULL, *act, *act_prev = NULL;
 620
 621         if (rtattr_parse_nested(tb, TCA_ACT_MAX_PRIO, rta) < 0)
 622                 return -EINVAL;
 623
 624         if (event == RTM_DELACTION && n->nlmsg_flags&NLM_F_ROOT) {
 625                 if (tb[0] != NULL && tb[1] == NULL)
 626                         return tca_action_flush(tb[0], n, pid);
 627         }
 628
 629         for (i=0; i < TCA_ACT_MAX_PRIO && tb[i]; i++) {
 630                 act = tcf_action_get_1(tb[i], n, pid, &ret);
 631                 if (act == NULL)
 632                         goto err;
 633                 act->order = i+1;
 634
 635                 if (head == NULL)
 636                         head = act;
 637                 else
 638                         act_prev->next = act;
 639                 act_prev = act;
 640         }
 641
 642         if (event == RTM_GETACTION)
 643                 ret = act_get_notify(pid, n, head, event);
 644         else { /* delete */
 645                 struct sk_buff *skb;
 646
 647                 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 648                 if (!skb) {
 649                         ret = -ENOBUFS;
 650                         goto err;
 651                 }
 652
 653                 if (tca_get_fill(skb, head, pid, n->nlmsg_seq, 0, event,
 654                                  0, 1) <= 0) {
 655                         kfree_skb(skb);
 656                         ret = -EINVAL;
 657                         goto err;
 658                 }
 659
 660                 /* now do the delete */
 661                 tcf_action_destroy(head, 0);
 662                 ret = rtnetlink_send(skb, pid, RTNLGRP_TC,
 663                                      n->nlmsg_flags&NLM_F_ECHO);
 664                 if (ret > 0)
 665                         return 0;
 666                 return ret;
 667         }
 668 err:
 669         cleanup_a(head);
 670         return ret;
 671 }
 672
 673 static int tcf_add_notify(struct tc_action *a, u32 pid, u32 seq, int event,
 674                           u16 flags)
 675 {
 676         struct tcamsg *t;
 677         struct nlmsghdr *nlh;
 678         struct sk_buff *skb;
 679         struct rtattr *x;
 680         unsigned char *b;
 681         int err = 0;
 682
 683         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 684         if (!skb)
 685                 return -ENOBUFS;
 686
 687         b = (unsigned char *)skb->tail;
 688
 689         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
 690         t = NLMSG_DATA(nlh);
 691         t->tca_family = AF_UNSPEC;
 692         t->tca__pad1 = 0;
 693         t->tca__pad2 = 0;
 694
 695         x = (struct rtattr*) skb->tail;
 696         RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
 697
 698         if (tcf_action_dump(skb, a, 0, 0) < 0)
 699                 goto rtattr_failure;
 700
 701         x->rta_len = skb->tail - (u8*)x;
 702
 703         nlh->nlmsg_len = skb->tail - b;
 704         NETLINK_CB(skb).dst_group = RTNLGRP_TC;
 705
 706         err = rtnetlink_send(skb, pid, RTNLGRP_TC, flags&NLM_F_ECHO);
 707         if (err > 0)
 708                 err = 0;
 709         return err;
 710
 711 rtattr_failure:
 712 nlmsg_failure:
 713         kfree_skb(skb);
 714         return -1;
 715 }
 716
 717
 718 static int
 719 tcf_action_add(struct rtattr *rta, struct nlmsghdr *n, u32 pid, int ovr)
 720 {
 721         int ret = 0;
 722         struct tc_action *act;
 723         struct tc_action *a;
 724         u32 seq = n->nlmsg_seq;
 725
 726         act = tcf_action_init(rta, NULL, NULL, ovr, 0, &ret);
 727         if (act == NULL)
 728                 goto done;
 729
 730         /* dump then free all the actions after update; inserted policy
 731          * stays intact
 732          * */
 733         ret = tcf_add_notify(act, pid, seq, RTM_NEWACTION, n->nlmsg_flags);
 734         for (a = act; a; a = act) {
 735                 act = a->next;
 736                 kfree(a);
 737         }
 738 done:
 739         return ret;
 740 }
 741
 742 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
 743 {
 744         struct rtattr **tca = arg;
 745         u32 pid = skb ? NETLINK_CB(skb).pid : 0;
 746         int ret = 0, ovr = 0;
 747
 748         if (tca[TCA_ACT_TAB-1] == NULL) {
 749                 printk("tc_ctl_action: received NO action attribs\n");
 750                 return -EINVAL;
 751         }
 752
 753         /* n->nlmsg_flags&NLM_F_CREATE
 754          * */
 755         switch (n->nlmsg_type) {
 756         case RTM_NEWACTION:
 757                 /* we are going to assume all other flags
 758                  * imply create only if it doesnt exist
 759                  * Note that CREATE | EXCL implies that
 760                  * but since we want avoid ambiguity (eg when flags
 761                  * is zero) then just set this
 762                  */
 763                 if (n->nlmsg_flags&NLM_F_REPLACE)
 764                         ovr = 1;
 765 replay:
 766                 ret = tcf_action_add(tca[TCA_ACT_TAB-1], n, pid, ovr);
 767                 if (ret == -EAGAIN)
 768                         goto replay;
 769                 break;
 770         case RTM_DELACTION:
 771                 ret = tca_action_gd(tca[TCA_ACT_TAB-1], n, pid, RTM_DELACTION);
 772                 break;
 773         case RTM_GETACTION:
 774                 ret = tca_action_gd(tca[TCA_ACT_TAB-1], n, pid, RTM_GETACTION);
 775                 break;
 776         default:
 777                 BUG();
 778         }
 779
 780         return ret;
 781 }
 782
 783 static struct rtattr *
 784 find_dump_kind(struct nlmsghdr *n)
 785 {
 786         struct rtattr *tb1, *tb2[TCA_ACT_MAX+1];
 787         struct rtattr *tb[TCA_ACT_MAX_PRIO + 1];
 788         struct rtattr *rta[TCAA_MAX + 1];
 789         struct rtattr *kind;
 790         int min_len = NLMSG_LENGTH(sizeof(struct tcamsg));
 791         int attrlen = n->nlmsg_len - NLMSG_ALIGN(min_len);
 792         struct rtattr *attr = (void *) n + NLMSG_ALIGN(min_len);
 793
 794         if (rtattr_parse(rta, TCAA_MAX, attr, attrlen) < 0)
 795                 return NULL;
 796         tb1 = rta[TCA_ACT_TAB - 1];
 797         if (tb1 == NULL)
 798                 return NULL;
 799
 800         if (rtattr_parse(tb, TCA_ACT_MAX_PRIO, RTA_DATA(tb1),
 801                          NLMSG_ALIGN(RTA_PAYLOAD(tb1))) < 0)
 802                 return NULL;
 803         if (tb[0] == NULL)
 804                 return NULL;
 805
 806         if (rtattr_parse(tb2, TCA_ACT_MAX, RTA_DATA(tb[0]),
 807                          RTA_PAYLOAD(tb[0])) < 0)
 808                 return NULL;
 809         kind = tb2[TCA_ACT_KIND-1];
 810
 811         return kind;
 812 }
 813
 814 static int
 815 tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
 816 {
 817         struct nlmsghdr *nlh;
 818         unsigned char *b = skb->tail;
 819         struct rtattr *x;
 820         struct tc_action_ops *a_o;
 821         struct tc_action a;
 822         int ret = 0;
 823         struct tcamsg *t = (struct tcamsg *) NLMSG_DATA(cb->nlh);
 824         struct rtattr *kind = find_dump_kind(cb->nlh);
 825
 826         if (kind == NULL) {
 827                 printk("tc_dump_action: action bad kind\n");
 828                 return 0;
 829         }
 830
 831         a_o = tc_lookup_action(kind);
 832         if (a_o == NULL) {
 833                 return 0;
 834         }
 835
 836         memset(&a, 0, sizeof(struct tc_action));
 837         a.ops = a_o;
 838
 839         if (a_o->walk == NULL) {
 840                 printk("tc_dump_action: %s !capable of dumping table\n", a_o->kind);
 841                 goto rtattr_failure;
 842         }
 843
 844         nlh = NLMSG_PUT(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
 845                         cb->nlh->nlmsg_type, sizeof(*t));
 846         t = NLMSG_DATA(nlh);
 847         t->tca_family = AF_UNSPEC;
 848         t->tca__pad1 = 0;
 849         t->tca__pad2 = 0;
 850
 851         x = (struct rtattr *) skb->tail;
 852         RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
 853
 854         ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
 855         if (ret < 0)
 856                 goto rtattr_failure;
 857
 858         if (ret > 0) {
 859                 x->rta_len = skb->tail - (u8 *) x;
 860                 ret = skb->len;
 861         } else
 862                 skb_trim(skb, (u8*)x - skb->data);
 863
 864         nlh->nlmsg_len = skb->tail - b;
 865         if (NETLINK_CB(cb->skb).pid && ret)
 866                 nlh->nlmsg_flags |= NLM_F_MULTI;
 867         module_put(a_o->owner);
 868         return skb->len;
 869
 870 rtattr_failure:
 871 nlmsg_failure:
 872         module_put(a_o->owner);
 873         skb_trim(skb, b - skb->data);
 874         return skb->len;
 875 }
 876
 877 static int __init tc_action_init(void)
 878 {
 879         struct rtnetlink_link *link_p = rtnetlink_links[PF_UNSPEC];
 880
 881         if (link_p) {
 882                 link_p[RTM_NEWACTION-RTM_BASE].doit = tc_ctl_action;
 883                 link_p[RTM_DELACTION-RTM_BASE].doit = tc_ctl_action;
 884                 link_p[RTM_GETACTION-RTM_BASE].doit = tc_ctl_action;
 885                 link_p[RTM_GETACTION-RTM_BASE].dumpit = tc_dump_action;
 886         }
 887
 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);