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/types.h>
  18 #include <linux/kernel.h>
  19 #include <linux/sched.h>
  20 #include <linux/string.h>
  21 #include <linux/mm.h>
  22 #include <linux/socket.h>
  23 #include <linux/sockios.h>
  24 #include <linux/in.h>
  25 #include <linux/errno.h>
  26 #include <linux/interrupt.h>
  27 #include <linux/netdevice.h>
  28 #include <linux/skbuff.h>
  29 #include <linux/rtnetlink.h>
  30 #include <linux/init.h>
  31 #include <linux/kmod.h>
  32 #include <net/sock.h>
  33 #include <net/sch_generic.h>
  34 #include <net/act_api.h>
  35
  36 #if 0 /* control */
  37 #define DPRINTK(format, args...) printk(KERN_DEBUG format, ##args)
  38 #else
  39 #define DPRINTK(format, args...)
  40 #endif
  41 #if 0 /* data */
  42 #define D2PRINTK(format, args...) printk(KERN_DEBUG format, ##args)
  43 #else
  44 #define D2PRINTK(format, args...)
  45 #endif
  46
  47 static struct tc_action_ops *act_base = NULL;
  48 static DEFINE_RWLOCK(act_mod_lock);
  49
  50 int tcf_register_action(struct tc_action_ops *act)
  51 {
  52         struct tc_action_ops *a, **ap;
  53
  54         write_lock(&act_mod_lock);
  55         for (ap = &act_base; (a = *ap) != NULL; ap = &a->next) {
  56                 if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
  57                         write_unlock(&act_mod_lock);
  58                         return -EEXIST;
  59                 }
  60         }
  61         act->next = NULL;
  62         *ap = act;
  63         write_unlock(&act_mod_lock);
  64         return 0;
  65 }
  66
  67 int tcf_unregister_action(struct tc_action_ops *act)
  68 {
  69         struct tc_action_ops *a, **ap;
  70         int err = -ENOENT;
  71
  72         write_lock(&act_mod_lock);
  73         for (ap = &act_base; (a = *ap) != NULL; ap = &a->next)
  74                 if (a == act)
  75                         break;
  76         if (a) {
  77                 *ap = a->next;
  78                 a->next = NULL;
  79                 err = 0;
  80         }
  81         write_unlock(&act_mod_lock);
  82         return err;
  83 }
  84
  85 /* lookup by name */
  86 static struct tc_action_ops *tc_lookup_action_n(char *kind)
  87 {
  88         struct tc_action_ops *a = NULL;
  89
  90         if (kind) {
  91                 read_lock(&act_mod_lock);
  92                 for (a = act_base; a; a = a->next) {
  93                         if (strcmp(kind, a->kind) == 0) {
  94                                 if (!try_module_get(a->owner)) {
  95                                         read_unlock(&act_mod_lock);
  96                                         return NULL;
  97                                 }
  98                                 break;
  99                         }
 100                 }
 101                 read_unlock(&act_mod_lock);
 102         }
 103         return a;
 104 }
 105
 106 /* lookup by rtattr */
 107 static struct tc_action_ops *tc_lookup_action(struct rtattr *kind)
 108 {
 109         struct tc_action_ops *a = NULL;
 110
 111         if (kind) {
 112                 read_lock(&act_mod_lock);
 113                 for (a = act_base; a; a = a->next) {
 114                         if (rtattr_strcmp(kind, a->kind) == 0) {
 115                                 if (!try_module_get(a->owner)) {
 116                                         read_unlock(&act_mod_lock);
 117                                         return NULL;
 118                                 }
 119                                 break;
 120                         }
 121                 }
 122                 read_unlock(&act_mod_lock);
 123         }
 124         return a;
 125 }
 126
 127 #if 0
 128 /* lookup by id */
 129 static struct tc_action_ops *tc_lookup_action_id(u32 type)
 130 {
 131         struct tc_action_ops *a = NULL;
 132
 133         if (type) {
 134                 read_lock(&act_mod_lock);
 135                 for (a = act_base; a; a = a->next) {
 136                         if (a->type == type) {
 137                                 if (!try_module_get(a->owner)) {
 138                                         read_unlock(&act_mod_lock);
 139                                         return NULL;
 140                                 }
 141                                 break;
 142                         }
 143                 }
 144                 read_unlock(&act_mod_lock);
 145         }
 146         return a;
 147 }
 148 #endif
 149
 150 int tcf_action_exec(struct sk_buff *skb, struct tc_action *act,
 151                     struct tcf_result *res)
 152 {
 153         struct tc_action *a;
 154         int ret = -1;
 155
 156         if (skb->tc_verd & TC_NCLS) {
 157                 skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
 158                 D2PRINTK("(%p)tcf_action_exec: cleared TC_NCLS in %s out %s\n",
 159                          skb, skb->input_dev ? skb->input_dev->name : "xxx",
 160                          skb->dev->name);
 161                 ret = TC_ACT_OK;
 162                 goto exec_done;
 163         }
 164         while ((a = act) != NULL) {
 165 repeat:
 166                 if (a->ops && a->ops->act) {
 167                         ret = a->ops->act(skb, a, res);
 168                         if (TC_MUNGED & skb->tc_verd) {
 169                                 /* copied already, allow trampling */
 170                                 skb->tc_verd = SET_TC_OK2MUNGE(skb->tc_verd);
 171                                 skb->tc_verd = CLR_TC_MUNGED(skb->tc_verd);
 172                         }
 173                         if (ret == TC_ACT_REPEAT)
 174                                 goto repeat;    /* we need a ttl - JHS */
 175                         if (ret != TC_ACT_PIPE)
 176                                 goto exec_done;
 177                 }
 178                 act = a->next;
 179         }
 180 exec_done:
 181         return ret;
 182 }
 183
 184 void tcf_action_destroy(struct tc_action *act, int bind)
 185 {
 186         struct tc_action *a;
 187
 188         for (a = act; a; a = act) {
 189                 if (a->ops && a->ops->cleanup) {
 190                         DPRINTK("tcf_action_destroy destroying %p next %p\n",
 191                                 a, a->next);
 192                         if (a->ops->cleanup(a, bind) == ACT_P_DELETED)
 193                                 module_put(a->ops->owner);
 194                         act = act->next;
 195                         kfree(a);
 196                 } else { /*FIXME: Remove later - catch insertion bugs*/
 197                         printk("tcf_action_destroy: BUG? destroying NULL ops\n");
 198                         act = act->next;
 199                         kfree(a);
 200                 }
 201         }
 202 }
 203
 204 int
 205 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 206 {
 207         int err = -EINVAL;
 208
 209         if (a->ops == NULL || a->ops->dump == NULL)
 210                 return err;
 211         return a->ops->dump(skb, a, bind, ref);
 212 }
 213
 214 int
 215 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 216 {
 217         int err = -EINVAL;
 218         unsigned char *b = skb->tail;
 219         struct rtattr *r;
 220
 221         if (a->ops == NULL || a->ops->dump == NULL)
 222                 return err;
 223
 224         RTA_PUT(skb, TCA_KIND, IFNAMSIZ, a->ops->kind);
 225         if (tcf_action_copy_stats(skb, a, 0))
 226                 goto rtattr_failure;
 227         r = (struct rtattr*) skb->tail;
 228         RTA_PUT(skb, TCA_OPTIONS, 0, NULL);
 229         if ((err = tcf_action_dump_old(skb, a, bind, ref)) > 0) {
 230                 r->rta_len = skb->tail - (u8*)r;
 231                 return err;
 232         }
 233
 234 rtattr_failure:
 235         skb_trim(skb, b - skb->data);
 236         return -1;
 237 }
 238
 239 int
 240 tcf_action_dump(struct sk_buff *skb, struct tc_action *act, int bind, int ref)
 241 {
 242         struct tc_action *a;
 243         int err = -EINVAL;
 244         unsigned char *b = skb->tail;
 245         struct rtattr *r ;
 246
 247         while ((a = act) != NULL) {
 248                 r = (struct rtattr*) skb->tail;
 249                 act = a->next;
 250                 RTA_PUT(skb, a->order, 0, NULL);
 251                 err = tcf_action_dump_1(skb, a, bind, ref);
 252                 if (err < 0)
 253                         goto rtattr_failure;
 254                 r->rta_len = skb->tail - (u8*)r;
 255         }
 256
 257         return 0;
 258
 259 rtattr_failure:
 260         skb_trim(skb, b - skb->data);
 261         return -err;
 262 }
 263
 264 struct tc_action *tcf_action_init_1(struct rtattr *rta, struct rtattr *est,
 265                                     char *name, int ovr, int bind, int *err)
 266 {
 267         struct tc_action *a;
 268         struct tc_action_ops *a_o;
 269         char act_name[IFNAMSIZ];
 270         struct rtattr *tb[TCA_ACT_MAX+1];
 271         struct rtattr *kind;
 272
 273         *err = -EINVAL;
 274
 275         if (name == NULL) {
 276                 if (rtattr_parse_nested(tb, TCA_ACT_MAX, rta) < 0)
 277                         goto err_out;
 278                 kind = tb[TCA_ACT_KIND-1];
 279                 if (kind == NULL)
 280                         goto err_out;
 281                 if (rtattr_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
 282                         goto err_out;
 283         } else {
 284                 if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
 285                         goto err_out;
 286         }
 287
 288         a_o = tc_lookup_action_n(act_name);
 289         if (a_o == NULL) {
 290 #ifdef CONFIG_KMOD
 291                 rtnl_unlock();
 292                 request_module("act_%s", act_name);
 293                 rtnl_lock();
 294
 295                 a_o = tc_lookup_action_n(act_name);
 296
 297                 /* We dropped the RTNL semaphore in order to
 298                  * perform the module load.  So, even if we
 299                  * succeeded in loading the module we have to
 300                  * tell the caller to replay the request.  We
 301                  * indicate this using -EAGAIN.
 302                  */
 303                 if (a_o != NULL) {
 304                         *err = -EAGAIN;
 305                         goto err_mod;
 306                 }
 307 #endif
 308                 goto err_out;
 309         }
 310
 311         *err = -ENOMEM;
 312         a = kmalloc(sizeof(*a), GFP_KERNEL);
 313         if (a == NULL)
 314                 goto err_mod;
 315         memset(a, 0, sizeof(*a));
 316
 317         /* backward compatibility for policer */
 318         if (name == NULL)
 319                 *err = a_o->init(tb[TCA_ACT_OPTIONS-1], est, a, ovr, bind);
 320         else
 321                 *err = a_o->init(rta, est, a, ovr, bind);
 322         if (*err < 0)
 323                 goto err_free;
 324
 325         /* module count goes up only when brand new policy is created
 326            if it exists and is only bound to in a_o->init() then
 327            ACT_P_CREATED is not returned (a zero is).
 328         */
 329         if (*err != ACT_P_CREATED)
 330                 module_put(a_o->owner);
 331         a->ops = a_o;
 332         DPRINTK("tcf_action_init_1: successfull %s\n", act_name);
 333
 334         *err = 0;
 335         return a;
 336
 337 err_free:
 338         kfree(a);
 339 err_mod:
 340         module_put(a_o->owner);
 341 err_out:
 342         return NULL;
 343 }
 344
 345 struct tc_action *tcf_action_init(struct rtattr *rta, struct rtattr *est,
 346                                   char *name, int ovr, int bind, int *err)
 347 {
 348         struct rtattr *tb[TCA_ACT_MAX_PRIO+1];
 349         struct tc_action *head = NULL, *act, *act_prev = NULL;
 350         int i;
 351
 352         if (rtattr_parse_nested(tb, TCA_ACT_MAX_PRIO, rta) < 0) {
 353                 *err = -EINVAL;
 354                 return head;
 355         }
 356
 357         for (i=0; i < TCA_ACT_MAX_PRIO && tb[i]; i++) {
 358                 act = tcf_action_init_1(tb[i], est, name, ovr, bind, err);
 359                 if (act == NULL)
 360                         goto err;
 361                 act->order = i+1;
 362
 363                 if (head == NULL)
 364                         head = act;
 365                 else
 366                         act_prev->next = act;
 367                 act_prev = act;
 368         }
 369         return head;
 370
 371 err:
 372         if (head != NULL)
 373                 tcf_action_destroy(head, bind);
 374         return NULL;
 375 }
 376
 377 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
 378                           int compat_mode)
 379 {
 380         int err = 0;
 381         struct gnet_dump d;
 382         struct tcf_act_hdr *h = a->priv;
 383
 384         if (h == NULL)
 385                 goto errout;
 386
 387         /* compat_mode being true specifies a call that is supposed
 388          * to add additional backward compatiblity statistic TLVs.
 389          */
 390         if (compat_mode) {
 391                 if (a->type == TCA_OLD_COMPAT)
 392                         err = gnet_stats_start_copy_compat(skb, 0,
 393                                 TCA_STATS, TCA_XSTATS, h->stats_lock, &d);
 394                 else
 395                         return 0;
 396         } else
 397                 err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
 398                         h->stats_lock, &d);
 399
 400         if (err < 0)
 401                 goto errout;
 402
 403         if (a->ops != NULL && a->ops->get_stats != NULL)
 404                 if (a->ops->get_stats(skb, a) < 0)
 405                         goto errout;
 406
 407         if (gnet_stats_copy_basic(&d, &h->bstats) < 0 ||
 408 #ifdef CONFIG_NET_ESTIMATOR
 409             gnet_stats_copy_rate_est(&d, &h->rate_est) < 0 ||
 410 #endif
 411             gnet_stats_copy_queue(&d, &h->qstats) < 0)
 412                 goto errout;
 413
 414         if (gnet_stats_finish_copy(&d) < 0)
 415                 goto errout;
 416
 417         return 0;
 418
 419 errout:
 420         return -1;
 421 }
 422
 423 static int
 424 tca_get_fill(struct sk_buff *skb, struct tc_action *a, u32 pid, u32 seq,
 425              u16 flags, int event, int bind, int ref)
 426 {
 427         struct tcamsg *t;
 428         struct nlmsghdr *nlh;
 429         unsigned char *b = skb->tail;
 430         struct rtattr *x;
 431
 432         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
 433
 434         t = NLMSG_DATA(nlh);
 435         t->tca_family = AF_UNSPEC;
 436         t->tca__pad1 = 0;
 437         t->tca__pad2 = 0;
 438
 439         x = (struct rtattr*) skb->tail;
 440         RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
 441
 442         if (tcf_action_dump(skb, a, bind, ref) < 0)
 443                 goto rtattr_failure;
 444
 445         x->rta_len = skb->tail - (u8*)x;
 446
 447         nlh->nlmsg_len = skb->tail - b;
 448         return skb->len;
 449
 450 rtattr_failure:
 451 nlmsg_failure:
 452         skb_trim(skb, b - skb->data);
 453         return -1;
 454 }
 455
 456 static int
 457 act_get_notify(u32 pid, struct nlmsghdr *n, struct tc_action *a, int event)
 458 {
 459         struct sk_buff *skb;
 460         int err = 0;
 461
 462         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 463         if (!skb)
 464                 return -ENOBUFS;
 465         if (tca_get_fill(skb, a, pid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
 466                 kfree_skb(skb);
 467                 return -EINVAL;
 468         }
 469         err = netlink_unicast(rtnl, skb, pid, MSG_DONTWAIT);
 470         if (err > 0)
 471                 err = 0;
 472         return err;
 473 }
 474
 475 static struct tc_action *
 476 tcf_action_get_1(struct rtattr *rta, struct nlmsghdr *n, u32 pid, int *err)
 477 {
 478         struct rtattr *tb[TCA_ACT_MAX+1];
 479         struct tc_action *a;
 480         int index;
 481
 482         *err = -EINVAL;
 483         if (rtattr_parse_nested(tb, TCA_ACT_MAX, rta) < 0)
 484                 return NULL;
 485
 486         if (tb[TCA_ACT_INDEX - 1] == NULL ||
 487             RTA_PAYLOAD(tb[TCA_ACT_INDEX - 1]) < sizeof(index))
 488                 return NULL;
 489         index = *(int *)RTA_DATA(tb[TCA_ACT_INDEX - 1]);
 490
 491         *err = -ENOMEM;
 492         a = kmalloc(sizeof(struct tc_action), GFP_KERNEL);
 493         if (a == NULL)
 494                 return NULL;
 495         memset(a, 0, sizeof(struct tc_action));
 496
 497         *err = -EINVAL;
 498         a->ops = tc_lookup_action(tb[TCA_ACT_KIND - 1]);
 499         if (a->ops == NULL)
 500                 goto err_free;
 501         if (a->ops->lookup == NULL)
 502                 goto err_mod;
 503         *err = -ENOENT;
 504         if (a->ops->lookup(a, index) == 0)
 505                 goto err_mod;
 506
 507         module_put(a->ops->owner);
 508         *err = 0;
 509         return a;
 510 err_mod:
 511         module_put(a->ops->owner);
 512 err_free:
 513         kfree(a);
 514         return NULL;
 515 }
 516
 517 static void cleanup_a(struct tc_action *act)
 518 {
 519         struct tc_action *a;
 520
 521         for (a = act; a; a = act) {
 522                 act = a->next;
 523                 kfree(a);
 524         }
 525 }
 526
 527 static struct tc_action *create_a(int i)
 528 {
 529         struct tc_action *act;
 530
 531         act = kmalloc(sizeof(*act), GFP_KERNEL);
 532         if (act == NULL) {
 533                 printk("create_a: failed to alloc!\n");
 534                 return NULL;
 535         }
 536         memset(act, 0, sizeof(*act));
 537         act->order = i;
 538         return act;
 539 }
 540
 541 static int tca_action_flush(struct rtattr *rta, struct nlmsghdr *n, u32 pid)
 542 {
 543         struct sk_buff *skb;
 544         unsigned char *b;
 545         struct nlmsghdr *nlh;
 546         struct tcamsg *t;
 547         struct netlink_callback dcb;
 548         struct rtattr *x;
 549         struct rtattr *tb[TCA_ACT_MAX+1];
 550         struct rtattr *kind;
 551         struct tc_action *a = create_a(0);
 552         int err = -EINVAL;
 553
 554         if (a == NULL) {
 555                 printk("tca_action_flush: couldnt create tc_action\n");
 556                 return err;
 557         }
 558
 559         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 560         if (!skb) {
 561                 printk("tca_action_flush: failed skb alloc\n");
 562                 kfree(a);
 563                 return -ENOBUFS;
 564         }
 565
 566         b = (unsigned char *)skb->tail;
 567
 568         if (rtattr_parse_nested(tb, TCA_ACT_MAX, rta) < 0)
 569                 goto err_out;
 570
 571         kind = tb[TCA_ACT_KIND-1];
 572         a->ops = tc_lookup_action(kind);
 573         if (a->ops == NULL)
 574                 goto err_out;
 575
 576         nlh = NLMSG_PUT(skb, pid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t));
 577         t = NLMSG_DATA(nlh);
 578         t->tca_family = AF_UNSPEC;
 579         t->tca__pad1 = 0;
 580         t->tca__pad2 = 0;
 581
 582         x = (struct rtattr *) skb->tail;
 583         RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
 584
 585         err = a->ops->walk(skb, &dcb, RTM_DELACTION, a);
 586         if (err < 0)
 587                 goto rtattr_failure;
 588
 589         x->rta_len = skb->tail - (u8 *) x;
 590
 591         nlh->nlmsg_len = skb->tail - b;
 592         nlh->nlmsg_flags |= NLM_F_ROOT;
 593         module_put(a->ops->owner);
 594         kfree(a);
 595         err = rtnetlink_send(skb, pid, RTNLGRP_TC, n->nlmsg_flags&NLM_F_ECHO);
 596         if (err > 0)
 597                 return 0;
 598
 599         return err;
 600
 601 rtattr_failure:
 602         module_put(a->ops->owner);
 603 nlmsg_failure:
 604 err_out:
 605         kfree_skb(skb);
 606         kfree(a);
 607         return err;
 608 }
 609
 610 static int
 611 tca_action_gd(struct rtattr *rta, struct nlmsghdr *n, u32 pid, int event)
 612 {
 613         int i, ret = 0;
 614         struct rtattr *tb[TCA_ACT_MAX_PRIO+1];
 615         struct tc_action *head = NULL, *act, *act_prev = NULL;
 616
 617         if (rtattr_parse_nested(tb, TCA_ACT_MAX_PRIO, rta) < 0)
 618                 return -EINVAL;
 619
 620         if (event == RTM_DELACTION && n->nlmsg_flags&NLM_F_ROOT) {
 621                 if (tb[0] != NULL && tb[1] == NULL)
 622                         return tca_action_flush(tb[0], n, pid);
 623         }
 624
 625         for (i=0; i < TCA_ACT_MAX_PRIO && tb[i]; i++) {
 626                 act = tcf_action_get_1(tb[i], n, pid, &ret);
 627                 if (act == NULL)
 628                         goto err;
 629                 act->order = i+1;
 630
 631                 if (head == NULL)
 632                         head = act;
 633                 else
 634                         act_prev->next = act;
 635                 act_prev = act;
 636         }
 637
 638         if (event == RTM_GETACTION)
 639                 ret = act_get_notify(pid, n, head, event);
 640         else { /* delete */
 641                 struct sk_buff *skb;
 642
 643                 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 644                 if (!skb) {
 645                         ret = -ENOBUFS;
 646                         goto err;
 647                 }
 648
 649                 if (tca_get_fill(skb, head, pid, n->nlmsg_seq, 0, event,
 650                                  0, 1) <= 0) {
 651                         kfree_skb(skb);
 652                         ret = -EINVAL;
 653                         goto err;
 654                 }
 655
 656                 /* now do the delete */
 657                 tcf_action_destroy(head, 0);
 658                 ret = rtnetlink_send(skb, pid, RTNLGRP_TC,
 659                                      n->nlmsg_flags&NLM_F_ECHO);
 660                 if (ret > 0)
 661                         return 0;
 662                 return ret;
 663         }
 664 err:
 665         cleanup_a(head);
 666         return ret;
 667 }
 668
 669 static int tcf_add_notify(struct tc_action *a, u32 pid, u32 seq, int event,
 670                           u16 flags)
 671 {
 672         struct tcamsg *t;
 673         struct nlmsghdr *nlh;
 674         struct sk_buff *skb;
 675         struct rtattr *x;
 676         unsigned char *b;
 677         int err = 0;
 678
 679         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 680         if (!skb)
 681                 return -ENOBUFS;
 682
 683         b = (unsigned char *)skb->tail;
 684
 685         nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
 686         t = NLMSG_DATA(nlh);
 687         t->tca_family = AF_UNSPEC;
 688         t->tca__pad1 = 0;
 689         t->tca__pad2 = 0;
 690
 691         x = (struct rtattr*) skb->tail;
 692         RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
 693
 694         if (tcf_action_dump(skb, a, 0, 0) < 0)
 695                 goto rtattr_failure;
 696
 697         x->rta_len = skb->tail - (u8*)x;
 698
 699         nlh->nlmsg_len = skb->tail - b;
 700         NETLINK_CB(skb).dst_group = RTNLGRP_TC;
 701
 702         err = rtnetlink_send(skb, pid, RTNLGRP_TC, flags&NLM_F_ECHO);
 703         if (err > 0)
 704                 err = 0;
 705         return err;
 706
 707 rtattr_failure:
 708 nlmsg_failure:
 709         kfree_skb(skb);
 710         return -1;
 711 }
 712
 713
 714 static int
 715 tcf_action_add(struct rtattr *rta, struct nlmsghdr *n, u32 pid, int ovr)
 716 {
 717         int ret = 0;
 718         struct tc_action *act;
 719         struct tc_action *a;
 720         u32 seq = n->nlmsg_seq;
 721
 722         act = tcf_action_init(rta, NULL, NULL, ovr, 0, &ret);
 723         if (act == NULL)
 724                 goto done;
 725
 726         /* dump then free all the actions after update; inserted policy
 727          * stays intact
 728          * */
 729         ret = tcf_add_notify(act, pid, seq, RTM_NEWACTION, n->nlmsg_flags);
 730         for (a = act; a; a = act) {
 731                 act = a->next;
 732                 kfree(a);
 733         }
 734 done:
 735         return ret;
 736 }
 737
 738 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
 739 {
 740         struct rtattr **tca = arg;
 741         u32 pid = skb ? NETLINK_CB(skb).pid : 0;
 742         int ret = 0, ovr = 0;
 743
 744         if (tca[TCA_ACT_TAB-1] == NULL) {
 745                 printk("tc_ctl_action: received NO action attribs\n");
 746                 return -EINVAL;
 747         }
 748
 749         /* n->nlmsg_flags&NLM_F_CREATE
 750          * */
 751         switch (n->nlmsg_type) {
 752         case RTM_NEWACTION:
 753                 /* we are going to assume all other flags
 754                  * imply create only if it doesnt exist
 755                  * Note that CREATE | EXCL implies that
 756                  * but since we want avoid ambiguity (eg when flags
 757                  * is zero) then just set this
 758                  */
 759                 if (n->nlmsg_flags&NLM_F_REPLACE)
 760                         ovr = 1;
 761 replay:
 762                 ret = tcf_action_add(tca[TCA_ACT_TAB-1], n, pid, ovr);
 763                 if (ret == -EAGAIN)
 764                         goto replay;
 765                 break;
 766         case RTM_DELACTION:
 767                 ret = tca_action_gd(tca[TCA_ACT_TAB-1], n, pid, RTM_DELACTION);
 768                 break;
 769         case RTM_GETACTION:
 770                 ret = tca_action_gd(tca[TCA_ACT_TAB-1], n, pid, RTM_GETACTION);
 771                 break;
 772         default:
 773                 BUG();
 774         }
 775
 776         return ret;
 777 }
 778
 779 static char *
 780 find_dump_kind(struct nlmsghdr *n)
 781 {
 782         struct rtattr *tb1, *tb2[TCA_ACT_MAX+1];
 783         struct rtattr *tb[TCA_ACT_MAX_PRIO + 1];
 784         struct rtattr *rta[TCAA_MAX + 1];
 785         struct rtattr *kind;
 786         int min_len = NLMSG_LENGTH(sizeof(struct tcamsg));
 787         int attrlen = n->nlmsg_len - NLMSG_ALIGN(min_len);
 788         struct rtattr *attr = (void *) n + NLMSG_ALIGN(min_len);
 789
 790         if (rtattr_parse(rta, TCAA_MAX, attr, attrlen) < 0)
 791                 return NULL;
 792         tb1 = rta[TCA_ACT_TAB - 1];
 793         if (tb1 == NULL)
 794                 return NULL;
 795
 796         if (rtattr_parse(tb, TCA_ACT_MAX_PRIO, RTA_DATA(tb1),
 797                          NLMSG_ALIGN(RTA_PAYLOAD(tb1))) < 0)
 798                 return NULL;
 799         if (tb[0] == NULL)
 800                 return NULL;
 801
 802         if (rtattr_parse(tb2, TCA_ACT_MAX, RTA_DATA(tb[0]),
 803                          RTA_PAYLOAD(tb[0])) < 0)
 804                 return NULL;
 805         kind = tb2[TCA_ACT_KIND-1];
 806
 807         return (char *) RTA_DATA(kind);
 808 }
 809
 810 static int
 811 tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
 812 {
 813         struct nlmsghdr *nlh;
 814         unsigned char *b = skb->tail;
 815         struct rtattr *x;
 816         struct tc_action_ops *a_o;
 817         struct tc_action a;
 818         int ret = 0;
 819         struct tcamsg *t = (struct tcamsg *) NLMSG_DATA(cb->nlh);
 820         char *kind = find_dump_kind(cb->nlh);
 821
 822         if (kind == NULL) {
 823                 printk("tc_dump_action: action bad kind\n");
 824                 return 0;
 825         }
 826
 827         a_o = tc_lookup_action_n(kind);
 828         if (a_o == NULL) {
 829                 printk("failed to find %s\n", kind);
 830                 return 0;
 831         }
 832
 833         memset(&a, 0, sizeof(struct tc_action));
 834         a.ops = a_o;
 835
 836         if (a_o->walk == NULL) {
 837                 printk("tc_dump_action: %s !capable of dumping table\n", kind);
 838                 goto rtattr_failure;
 839         }
 840
 841         nlh = NLMSG_PUT(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
 842                         cb->nlh->nlmsg_type, sizeof(*t));
 843         t = NLMSG_DATA(nlh);
 844         t->tca_family = AF_UNSPEC;
 845         t->tca__pad1 = 0;
 846         t->tca__pad2 = 0;
 847
 848         x = (struct rtattr *) skb->tail;
 849         RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
 850
 851         ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
 852         if (ret < 0)
 853                 goto rtattr_failure;
 854
 855         if (ret > 0) {
 856                 x->rta_len = skb->tail - (u8 *) x;
 857                 ret = skb->len;
 858         } else
 859                 skb_trim(skb, (u8*)x - skb->data);
 860
 861         nlh->nlmsg_len = skb->tail - b;
 862         if (NETLINK_CB(cb->skb).pid && ret)
 863                 nlh->nlmsg_flags |= NLM_F_MULTI;
 864         module_put(a_o->owner);
 865         return skb->len;
 866
 867 rtattr_failure:
 868 nlmsg_failure:
 869         module_put(a_o->owner);
 870         skb_trim(skb, b - skb->data);
 871         return skb->len;
 872 }
 873
 874 static int __init tc_action_init(void)
 875 {
 876         struct rtnetlink_link *link_p = rtnetlink_links[PF_UNSPEC];
 877
 878         if (link_p) {
 879                 link_p[RTM_NEWACTION-RTM_BASE].doit = tc_ctl_action;
 880                 link_p[RTM_DELACTION-RTM_BASE].doit = tc_ctl_action;
 881                 link_p[RTM_GETACTION-RTM_BASE].doit = tc_ctl_action;
 882                 link_p[RTM_GETACTION-RTM_BASE].dumpit = tc_dump_action;
 883         }
 884
 885         printk("TC classifier action (bugs to netdev@vger.kernel.org cc "
 886                "hadi@cyberus.ca)\n");
 887         return 0;
 888 }
 889
 890 subsys_initcall(tc_action_init);
 891
 892 EXPORT_SYMBOL(tcf_register_action);
 893 EXPORT_SYMBOL(tcf_unregister_action);
 894 EXPORT_SYMBOL(tcf_action_exec);
 895 EXPORT_SYMBOL(tcf_action_dump_1);