net/core/flow_offload.c

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #include <linux/kernel.h>
   3 #include <linux/slab.h>
   4 #include <net/act_api.h>
   5 #include <net/flow_offload.h>
   6 #include <linux/rtnetlink.h>
   7 #include <linux/mutex.h>
   8 #include <linux/rhashtable.h>
   9
  10 struct flow_rule *flow_rule_alloc(unsigned int num_actions)
  11 {
  12         struct flow_rule *rule;
  13         int i;
  14
  15         rule = kzalloc(struct_size(rule, action.entries, num_actions),
  16                        GFP_KERNEL);
  17         if (!rule)
  18                 return NULL;
  19
  20         rule->action.num_entries = num_actions;
  21         /* Pre-fill each action hw_stats with DONT_CARE.
  22          * Caller can override this if it wants stats for a given action.
  23          */
  24         for (i = 0; i < num_actions; i++)
  25                 rule->action.entries[i].hw_stats = FLOW_ACTION_HW_STATS_DONT_CARE;
  26
  27         return rule;
  28 }
  29 EXPORT_SYMBOL(flow_rule_alloc);
  30
  31 struct flow_offload_action *offload_action_alloc(unsigned int num_actions)
  32 {
  33         struct flow_offload_action *fl_action;
  34         int i;
  35
  36         fl_action = kzalloc(struct_size(fl_action, action.entries, num_actions),
  37                             GFP_KERNEL);
  38         if (!fl_action)
  39                 return NULL;
  40
  41         fl_action->action.num_entries = num_actions;
  42         /* Pre-fill each action hw_stats with DONT_CARE.
  43          * Caller can override this if it wants stats for a given action.
  44          */
  45         for (i = 0; i < num_actions; i++)
  46                 fl_action->action.entries[i].hw_stats = FLOW_ACTION_HW_STATS_DONT_CARE;
  47
  48         return fl_action;
  49 }
  50
  51 #define FLOW_DISSECTOR_MATCH(__rule, __type, __out)                             \
  52         const struct flow_match *__m = &(__rule)->match;                        \
  53         struct flow_dissector *__d = (__m)->dissector;                          \
  54                                                                                 \
  55         (__out)->key = skb_flow_dissector_target(__d, __type, (__m)->key);      \
  56         (__out)->mask = skb_flow_dissector_target(__d, __type, (__m)->mask);    \
  57
  58 void flow_rule_match_meta(const struct flow_rule *rule,
  59                           struct flow_match_meta *out)
  60 {
  61         FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_META, out);
  62 }
  63 EXPORT_SYMBOL(flow_rule_match_meta);
  64
  65 void flow_rule_match_basic(const struct flow_rule *rule,
  66                            struct flow_match_basic *out)
  67 {
  68         FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_BASIC, out);
  69 }
  70 EXPORT_SYMBOL(flow_rule_match_basic);
  71
  72 void flow_rule_match_control(const struct flow_rule *rule,
  73                              struct flow_match_control *out)
  74 {
  75         FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_CONTROL, out);
  76 }
  77 EXPORT_SYMBOL(flow_rule_match_control);
  78
  79 void flow_rule_match_eth_addrs(const struct flow_rule *rule,
  80                                struct flow_match_eth_addrs *out)
  81 {
  82         FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_ETH_ADDRS, out);
  83 }
  84 EXPORT_SYMBOL(flow_rule_match_eth_addrs);
  85
  86 void flow_rule_match_vlan(const struct flow_rule *rule,
  87                           struct flow_match_vlan *out)
  88 {
  89         FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_VLAN, out);
  90 }
  91 EXPORT_SYMBOL(flow_rule_match_vlan);
  92
  93 void flow_rule_match_cvlan(const struct flow_rule *rule,
  94                            struct flow_match_vlan *out)
  95 {
  96         FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_CVLAN, out);
  97 }
  98 EXPORT_SYMBOL(flow_rule_match_cvlan);
  99
 100 void flow_rule_match_ipv4_addrs(const struct flow_rule *rule,
 101                                 struct flow_match_ipv4_addrs *out)
 102 {
 103         FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_IPV4_ADDRS, out);
 104 }
 105 EXPORT_SYMBOL(flow_rule_match_ipv4_addrs);
 106
 107 void flow_rule_match_ipv6_addrs(const struct flow_rule *rule,
 108                                 struct flow_match_ipv6_addrs *out)
 109 {
 110         FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_IPV6_ADDRS, out);
 111 }
 112 EXPORT_SYMBOL(flow_rule_match_ipv6_addrs);
 113
 114 void flow_rule_match_ip(const struct flow_rule *rule,
 115                         struct flow_match_ip *out)
 116 {
 117         FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_IP, out);
 118 }
 119 EXPORT_SYMBOL(flow_rule_match_ip);
 120
 121 void flow_rule_match_ports(const struct flow_rule *rule,
 122                            struct flow_match_ports *out)
 123 {
 124         FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_PORTS, out);
 125 }
 126 EXPORT_SYMBOL(flow_rule_match_ports);
 127
 128 void flow_rule_match_tcp(const struct flow_rule *rule,
 129                          struct flow_match_tcp *out)
 130 {
 131         FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_TCP, out);
 132 }
 133 EXPORT_SYMBOL(flow_rule_match_tcp);
 134
 135 void flow_rule_match_icmp(const struct flow_rule *rule,
 136                           struct flow_match_icmp *out)
 137 {
 138         FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_ICMP, out);
 139 }
 140 EXPORT_SYMBOL(flow_rule_match_icmp);
 141
 142 void flow_rule_match_mpls(const struct flow_rule *rule,
 143                           struct flow_match_mpls *out)
 144 {
 145         FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_MPLS, out);
 146 }
 147 EXPORT_SYMBOL(flow_rule_match_mpls);
 148
 149 void flow_rule_match_enc_control(const struct flow_rule *rule,
 150                                  struct flow_match_control *out)
 151 {
 152         FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_ENC_CONTROL, out);
 153 }
 154 EXPORT_SYMBOL(flow_rule_match_enc_control);
 155
 156 void flow_rule_match_enc_ipv4_addrs(const struct flow_rule *rule,
 157                                     struct flow_match_ipv4_addrs *out)
 158 {
 159         FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS, out);
 160 }
 161 EXPORT_SYMBOL(flow_rule_match_enc_ipv4_addrs);
 162
 163 void flow_rule_match_enc_ipv6_addrs(const struct flow_rule *rule,
 164                                     struct flow_match_ipv6_addrs *out)
 165 {
 166         FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS, out);
 167 }
 168 EXPORT_SYMBOL(flow_rule_match_enc_ipv6_addrs);
 169
 170 void flow_rule_match_enc_ip(const struct flow_rule *rule,
 171                             struct flow_match_ip *out)
 172 {
 173         FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_ENC_IP, out);
 174 }
 175 EXPORT_SYMBOL(flow_rule_match_enc_ip);
 176
 177 void flow_rule_match_enc_ports(const struct flow_rule *rule,
 178                                struct flow_match_ports *out)
 179 {
 180         FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_ENC_PORTS, out);
 181 }
 182 EXPORT_SYMBOL(flow_rule_match_enc_ports);
 183
 184 void flow_rule_match_enc_keyid(const struct flow_rule *rule,
 185                                struct flow_match_enc_keyid *out)
 186 {
 187         FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_ENC_KEYID, out);
 188 }
 189 EXPORT_SYMBOL(flow_rule_match_enc_keyid);
 190
 191 void flow_rule_match_enc_opts(const struct flow_rule *rule,
 192                               struct flow_match_enc_opts *out)
 193 {
 194         FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_ENC_OPTS, out);
 195 }
 196 EXPORT_SYMBOL(flow_rule_match_enc_opts);
 197
 198 struct flow_action_cookie *flow_action_cookie_create(void *data,
 199                                                      unsigned int len,
 200                                                      gfp_t gfp)
 201 {
 202         struct flow_action_cookie *cookie;
 203
 204         cookie = kmalloc(sizeof(*cookie) + len, gfp);
 205         if (!cookie)
 206                 return NULL;
 207         cookie->cookie_len = len;
 208         memcpy(cookie->cookie, data, len);
 209         return cookie;
 210 }
 211 EXPORT_SYMBOL(flow_action_cookie_create);
 212
 213 void flow_action_cookie_destroy(struct flow_action_cookie *cookie)
 214 {
 215         kfree(cookie);
 216 }
 217 EXPORT_SYMBOL(flow_action_cookie_destroy);
 218
 219 void flow_rule_match_ct(const struct flow_rule *rule,
 220                         struct flow_match_ct *out)
 221 {
 222         FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_CT, out);
 223 }
 224 EXPORT_SYMBOL(flow_rule_match_ct);
 225
 226 struct flow_block_cb *flow_block_cb_alloc(flow_setup_cb_t *cb,
 227                                           void *cb_ident, void *cb_priv,
 228                                           void (*release)(void *cb_priv))
 229 {
 230         struct flow_block_cb *block_cb;
 231
 232         block_cb = kzalloc(sizeof(*block_cb), GFP_KERNEL);
 233         if (!block_cb)
 234                 return ERR_PTR(-ENOMEM);
 235
 236         block_cb->cb = cb;
 237         block_cb->cb_ident = cb_ident;
 238         block_cb->cb_priv = cb_priv;
 239         block_cb->release = release;
 240
 241         return block_cb;
 242 }
 243 EXPORT_SYMBOL(flow_block_cb_alloc);
 244
 245 void flow_block_cb_free(struct flow_block_cb *block_cb)
 246 {
 247         if (block_cb->release)
 248                 block_cb->release(block_cb->cb_priv);
 249
 250         kfree(block_cb);
 251 }
 252 EXPORT_SYMBOL(flow_block_cb_free);
 253
 254 struct flow_block_cb *flow_block_cb_lookup(struct flow_block *block,
 255                                            flow_setup_cb_t *cb, void *cb_ident)
 256 {
 257         struct flow_block_cb *block_cb;
 258
 259         list_for_each_entry(block_cb, &block->cb_list, list) {
 260                 if (block_cb->cb == cb &&
 261                     block_cb->cb_ident == cb_ident)
 262                         return block_cb;
 263         }
 264
 265         return NULL;
 266 }
 267 EXPORT_SYMBOL(flow_block_cb_lookup);
 268
 269 void *flow_block_cb_priv(struct flow_block_cb *block_cb)
 270 {
 271         return block_cb->cb_priv;
 272 }
 273 EXPORT_SYMBOL(flow_block_cb_priv);
 274
 275 void flow_block_cb_incref(struct flow_block_cb *block_cb)
 276 {
 277         block_cb->refcnt++;
 278 }
 279 EXPORT_SYMBOL(flow_block_cb_incref);
 280
 281 unsigned int flow_block_cb_decref(struct flow_block_cb *block_cb)
 282 {
 283         return --block_cb->refcnt;
 284 }
 285 EXPORT_SYMBOL(flow_block_cb_decref);
 286
 287 bool flow_block_cb_is_busy(flow_setup_cb_t *cb, void *cb_ident,
 288                            struct list_head *driver_block_list)
 289 {
 290         struct flow_block_cb *block_cb;
 291
 292         list_for_each_entry(block_cb, driver_block_list, driver_list) {
 293                 if (block_cb->cb == cb &&
 294                     block_cb->cb_ident == cb_ident)
 295                         return true;
 296         }
 297
 298         return false;
 299 }
 300 EXPORT_SYMBOL(flow_block_cb_is_busy);
 301
 302 int flow_block_cb_setup_simple(struct flow_block_offload *f,
 303                                struct list_head *driver_block_list,
 304                                flow_setup_cb_t *cb,
 305                                void *cb_ident, void *cb_priv,
 306                                bool ingress_only)
 307 {
 308         struct flow_block_cb *block_cb;
 309
 310         if (ingress_only &&
 311             f->binder_type != FLOW_BLOCK_BINDER_TYPE_CLSACT_INGRESS)
 312                 return -EOPNOTSUPP;
 313
 314         f->driver_block_list = driver_block_list;
 315
 316         switch (f->command) {
 317         case FLOW_BLOCK_BIND:
 318                 if (flow_block_cb_is_busy(cb, cb_ident, driver_block_list))
 319                         return -EBUSY;
 320
 321                 block_cb = flow_block_cb_alloc(cb, cb_ident, cb_priv, NULL);
 322                 if (IS_ERR(block_cb))
 323                         return PTR_ERR(block_cb);
 324
 325                 flow_block_cb_add(block_cb, f);
 326                 list_add_tail(&block_cb->driver_list, driver_block_list);
 327                 return 0;
 328         case FLOW_BLOCK_UNBIND:
 329                 block_cb = flow_block_cb_lookup(f->block, cb, cb_ident);
 330                 if (!block_cb)
 331                         return -ENOENT;
 332
 333                 flow_block_cb_remove(block_cb, f);
 334                 list_del(&block_cb->driver_list);
 335                 return 0;
 336         default:
 337                 return -EOPNOTSUPP;
 338         }
 339 }
 340 EXPORT_SYMBOL(flow_block_cb_setup_simple);
 341
 342 static DEFINE_MUTEX(flow_indr_block_lock);
 343 static LIST_HEAD(flow_block_indr_list);
 344 static LIST_HEAD(flow_block_indr_dev_list);
 345 static LIST_HEAD(flow_indir_dev_list);
 346
 347 struct flow_indr_dev {
 348         struct list_head                list;
 349         flow_indr_block_bind_cb_t       *cb;
 350         void                            *cb_priv;
 351         refcount_t                      refcnt;
 352 };
 353
 354 static struct flow_indr_dev *flow_indr_dev_alloc(flow_indr_block_bind_cb_t *cb,
 355                                                  void *cb_priv)
 356 {
 357         struct flow_indr_dev *indr_dev;
 358
 359         indr_dev = kmalloc(sizeof(*indr_dev), GFP_KERNEL);
 360         if (!indr_dev)
 361                 return NULL;
 362
 363         indr_dev->cb            = cb;
 364         indr_dev->cb_priv       = cb_priv;
 365         refcount_set(&indr_dev->refcnt, 1);
 366
 367         return indr_dev;
 368 }
 369
 370 struct flow_indir_dev_info {
 371         void *data;
 372         struct net_device *dev;
 373         struct Qdisc *sch;
 374         enum tc_setup_type type;
 375         void (*cleanup)(struct flow_block_cb *block_cb);
 376         struct list_head list;
 377         enum flow_block_command command;
 378         enum flow_block_binder_type binder_type;
 379         struct list_head *cb_list;
 380 };
 381
 382 static void existing_qdiscs_register(flow_indr_block_bind_cb_t *cb, void *cb_priv)
 383 {
 384         struct flow_block_offload bo;
 385         struct flow_indir_dev_info *cur;
 386
 387         list_for_each_entry(cur, &flow_indir_dev_list, list) {
 388                 memset(&bo, 0, sizeof(bo));
 389                 bo.command = cur->command;
 390                 bo.binder_type = cur->binder_type;
 391                 INIT_LIST_HEAD(&bo.cb_list);
 392                 cb(cur->dev, cur->sch, cb_priv, cur->type, &bo, cur->data, cur->cleanup);
 393                 list_splice(&bo.cb_list, cur->cb_list);
 394         }
 395 }
 396
 397 int flow_indr_dev_register(flow_indr_block_bind_cb_t *cb, void *cb_priv)
 398 {
 399         struct flow_indr_dev *indr_dev;
 400
 401         mutex_lock(&flow_indr_block_lock);
 402         list_for_each_entry(indr_dev, &flow_block_indr_dev_list, list) {
 403                 if (indr_dev->cb == cb &&
 404                     indr_dev->cb_priv == cb_priv) {
 405                         refcount_inc(&indr_dev->refcnt);
 406                         mutex_unlock(&flow_indr_block_lock);
 407                         return 0;
 408                 }
 409         }
 410
 411         indr_dev = flow_indr_dev_alloc(cb, cb_priv);
 412         if (!indr_dev) {
 413                 mutex_unlock(&flow_indr_block_lock);
 414                 return -ENOMEM;
 415         }
 416
 417         list_add(&indr_dev->list, &flow_block_indr_dev_list);
 418         existing_qdiscs_register(cb, cb_priv);
 419         mutex_unlock(&flow_indr_block_lock);
 420
 421         tcf_action_reoffload_cb(cb, cb_priv, true);
 422
 423         return 0;
 424 }
 425 EXPORT_SYMBOL(flow_indr_dev_register);
 426
 427 static void __flow_block_indr_cleanup(void (*release)(void *cb_priv),
 428                                       void *cb_priv,
 429                                       struct list_head *cleanup_list)
 430 {
 431         struct flow_block_cb *this, *next;
 432
 433         list_for_each_entry_safe(this, next, &flow_block_indr_list, indr.list) {
 434                 if (this->release == release &&
 435                     this->indr.cb_priv == cb_priv)
 436                         list_move(&this->indr.list, cleanup_list);
 437         }
 438 }
 439
 440 static void flow_block_indr_notify(struct list_head *cleanup_list)
 441 {
 442         struct flow_block_cb *this, *next;
 443
 444         list_for_each_entry_safe(this, next, cleanup_list, indr.list) {
 445                 list_del(&this->indr.list);
 446                 this->indr.cleanup(this);
 447         }
 448 }
 449
 450 void flow_indr_dev_unregister(flow_indr_block_bind_cb_t *cb, void *cb_priv,
 451                               void (*release)(void *cb_priv))
 452 {
 453         struct flow_indr_dev *this, *next, *indr_dev = NULL;
 454         LIST_HEAD(cleanup_list);
 455
 456         mutex_lock(&flow_indr_block_lock);
 457         list_for_each_entry_safe(this, next, &flow_block_indr_dev_list, list) {
 458                 if (this->cb == cb &&
 459                     this->cb_priv == cb_priv &&
 460                     refcount_dec_and_test(&this->refcnt)) {
 461                         indr_dev = this;
 462                         list_del(&indr_dev->list);
 463                         break;
 464                 }
 465         }
 466
 467         if (!indr_dev) {
 468                 mutex_unlock(&flow_indr_block_lock);
 469                 return;
 470         }
 471
 472         __flow_block_indr_cleanup(release, cb_priv, &cleanup_list);
 473         mutex_unlock(&flow_indr_block_lock);
 474
 475         tcf_action_reoffload_cb(cb, cb_priv, false);
 476         flow_block_indr_notify(&cleanup_list);
 477         kfree(indr_dev);
 478 }
 479 EXPORT_SYMBOL(flow_indr_dev_unregister);
 480
 481 static void flow_block_indr_init(struct flow_block_cb *flow_block,
 482                                  struct flow_block_offload *bo,
 483                                  struct net_device *dev, struct Qdisc *sch, void *data,
 484                                  void *cb_priv,
 485                                  void (*cleanup)(struct flow_block_cb *block_cb))
 486 {
 487         flow_block->indr.binder_type = bo->binder_type;
 488         flow_block->indr.data = data;
 489         flow_block->indr.cb_priv = cb_priv;
 490         flow_block->indr.dev = dev;
 491         flow_block->indr.sch = sch;
 492         flow_block->indr.cleanup = cleanup;
 493 }
 494
 495 struct flow_block_cb *flow_indr_block_cb_alloc(flow_setup_cb_t *cb,
 496                                                void *cb_ident, void *cb_priv,
 497                                                void (*release)(void *cb_priv),
 498                                                struct flow_block_offload *bo,
 499                                                struct net_device *dev,
 500                                                struct Qdisc *sch, void *data,
 501                                                void *indr_cb_priv,
 502                                                void (*cleanup)(struct flow_block_cb *block_cb))
 503 {
 504         struct flow_block_cb *block_cb;
 505
 506         block_cb = flow_block_cb_alloc(cb, cb_ident, cb_priv, release);
 507         if (IS_ERR(block_cb))
 508                 goto out;
 509
 510         flow_block_indr_init(block_cb, bo, dev, sch, data, indr_cb_priv, cleanup);
 511         list_add(&block_cb->indr.list, &flow_block_indr_list);
 512
 513 out:
 514         return block_cb;
 515 }
 516 EXPORT_SYMBOL(flow_indr_block_cb_alloc);
 517
 518 static struct flow_indir_dev_info *find_indir_dev(void *data)
 519 {
 520         struct flow_indir_dev_info *cur;
 521
 522         list_for_each_entry(cur, &flow_indir_dev_list, list) {
 523                 if (cur->data == data)
 524                         return cur;
 525         }
 526         return NULL;
 527 }
 528
 529 static int indir_dev_add(void *data, struct net_device *dev, struct Qdisc *sch,
 530                          enum tc_setup_type type, void (*cleanup)(struct flow_block_cb *block_cb),
 531                          struct flow_block_offload *bo)
 532 {
 533         struct flow_indir_dev_info *info;
 534
 535         info = find_indir_dev(data);
 536         if (info)
 537                 return -EEXIST;
 538
 539         info = kzalloc(sizeof(*info), GFP_KERNEL);
 540         if (!info)
 541                 return -ENOMEM;
 542
 543         info->data = data;
 544         info->dev = dev;
 545         info->sch = sch;
 546         info->type = type;
 547         info->cleanup = cleanup;
 548         info->command = bo->command;
 549         info->binder_type = bo->binder_type;
 550         info->cb_list = bo->cb_list_head;
 551
 552         list_add(&info->list, &flow_indir_dev_list);
 553         return 0;
 554 }
 555
 556 static int indir_dev_remove(void *data)
 557 {
 558         struct flow_indir_dev_info *info;
 559
 560         info = find_indir_dev(data);
 561         if (!info)
 562                 return -ENOENT;
 563
 564         list_del(&info->list);
 565
 566         kfree(info);
 567         return 0;
 568 }
 569
 570 int flow_indr_dev_setup_offload(struct net_device *dev, struct Qdisc *sch,
 571                                 enum tc_setup_type type, void *data,
 572                                 struct flow_block_offload *bo,
 573                                 void (*cleanup)(struct flow_block_cb *block_cb))
 574 {
 575         struct flow_indr_dev *this;
 576         u32 count = 0;
 577         int err;
 578
 579         mutex_lock(&flow_indr_block_lock);
 580         if (bo) {
 581                 if (bo->command == FLOW_BLOCK_BIND)
 582                         indir_dev_add(data, dev, sch, type, cleanup, bo);
 583                 else if (bo->command == FLOW_BLOCK_UNBIND)
 584                         indir_dev_remove(data);
 585         }
 586
 587         list_for_each_entry(this, &flow_block_indr_dev_list, list) {
 588                 err = this->cb(dev, sch, this->cb_priv, type, bo, data, cleanup);
 589                 if (!err)
 590                         count++;
 591         }
 592
 593         mutex_unlock(&flow_indr_block_lock);
 594
 595         return (bo && list_empty(&bo->cb_list)) ? -EOPNOTSUPP : count;
 596 }
 597 EXPORT_SYMBOL(flow_indr_dev_setup_offload);
 598
 599 bool flow_indr_dev_exists(void)
 600 {
 601         return !list_empty(&flow_block_indr_dev_list);
 602 }
 603 EXPORT_SYMBOL(flow_indr_dev_exists);