1 /* 2 * FQ_Codel - The FlowQueue-Codel scheduler/AQM 3 * 4 * $FreeBSD$ 5 * 6 * Copyright (C) 2016 Centre for Advanced Internet Architectures, 7 * Swinburne University of Technology, Melbourne, Australia. 8 * Portions of this code were made possible in part by a gift from 9 * The Comcast Innovation Fund. 10 * Implemented by Rasool Al-Saadi <ralsaadi@swin.edu.au> 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #ifdef _KERNEL 35 #include <sys/malloc.h> 36 #include <sys/socket.h> 37 //#include <sys/socketvar.h> 38 #include <sys/kernel.h> 39 #include <sys/mbuf.h> 40 #include <sys/module.h> 41 #include <net/if.h> /* IFNAMSIZ */ 42 #include <netinet/in.h> 43 #include <netinet/ip_var.h> /* ipfw_rule_ref */ 44 #include <netinet/ip_fw.h> /* flow_id */ 45 #include <netinet/ip_dummynet.h> 46 47 #include <sys/lock.h> 48 #include <sys/proc.h> 49 #include <sys/rwlock.h> 50 51 #include <netpfil/ipfw/ip_fw_private.h> 52 #include <sys/sysctl.h> 53 #include <netinet/ip.h> 54 #include <netinet/ip6.h> 55 #include <netinet/ip_icmp.h> 56 #include <netinet/tcp.h> 57 #include <netinet/udp.h> 58 #include <sys/queue.h> 59 #include <sys/hash.h> 60 61 #include <netpfil/ipfw/dn_heap.h> 62 #include <netpfil/ipfw/ip_dn_private.h> 63 64 #include <netpfil/ipfw/dn_aqm.h> 65 #include <netpfil/ipfw/dn_aqm_codel.h> 66 #include <netpfil/ipfw/dn_sched.h> 67 #include <netpfil/ipfw/dn_sched_fq_codel.h> 68 #include <netpfil/ipfw/dn_sched_fq_codel_helper.h> 69 70 #else 71 #include <dn_test.h> 72 #endif 73 74 /* NOTE: In fq_codel module, we reimplements CoDel AQM functions 75 * because fq_codel use different flows (sub-queues) structure and 76 * dn_queue includes many variables not needed by a flow (sub-queue 77 * )i.e. avoid extra overhead (88 bytes vs 208 bytes). 78 * Also, CoDel functions manages stats of sub-queues as well as the main queue. 79 */ 80 81 #define DN_SCHED_FQ_CODEL 6 82 83 static struct dn_alg fq_codel_desc; 84 85 /* fq_codel default parameters including codel */ 86 struct dn_sch_fq_codel_parms 87 fq_codel_sysctl = {{5000 * AQM_TIME_1US, 100000 * AQM_TIME_1US, 88 CODEL_ECN_ENABLED}, 1024, 10240, 1514}; 89 90 static int 91 fqcodel_sysctl_interval_handler(SYSCTL_HANDLER_ARGS) 92 { 93 int error; 94 long value; 95 96 value = fq_codel_sysctl.ccfg.interval; 97 value /= AQM_TIME_1US; 98 error = sysctl_handle_long(oidp, &value, 0, req); 99 if (error != 0 || req->newptr == NULL) 100 return (error); 101 if (value < 1 || value > 100 * AQM_TIME_1S) 102 return (EINVAL); 103 fq_codel_sysctl.ccfg.interval = value * AQM_TIME_1US ; 104 105 return (0); 106 } 107 108 static int 109 fqcodel_sysctl_target_handler(SYSCTL_HANDLER_ARGS) 110 { 111 int error; 112 long value; 113 114 value = fq_codel_sysctl.ccfg.target; 115 value /= AQM_TIME_1US; 116 error = sysctl_handle_long(oidp, &value, 0, req); 117 if (error != 0 || req->newptr == NULL) 118 return (error); 119 if (value < 1 || value > 5 * AQM_TIME_1S) 120 return (EINVAL); 121 fq_codel_sysctl.ccfg.target = value * AQM_TIME_1US ; 122 123 return (0); 124 } 125 126 127 SYSBEGIN(f4) 128 129 SYSCTL_DECL(_net_inet); 130 SYSCTL_DECL(_net_inet_ip); 131 SYSCTL_DECL(_net_inet_ip_dummynet); 132 static SYSCTL_NODE(_net_inet_ip_dummynet, OID_AUTO, fqcodel, 133 CTLFLAG_RW, 0, "FQ_CODEL"); 134 135 #ifdef SYSCTL_NODE 136 137 SYSCTL_PROC(_net_inet_ip_dummynet_fqcodel, OID_AUTO, target, 138 CTLTYPE_LONG | CTLFLAG_RW, NULL, 0, fqcodel_sysctl_target_handler, "L", 139 "FQ_CoDel target in microsecond"); 140 SYSCTL_PROC(_net_inet_ip_dummynet_fqcodel, OID_AUTO, interval, 141 CTLTYPE_LONG | CTLFLAG_RW, NULL, 0, fqcodel_sysctl_interval_handler, "L", 142 "FQ_CoDel interval in microsecond"); 143 144 SYSCTL_UINT(_net_inet_ip_dummynet_fqcodel, OID_AUTO, quantum, 145 CTLFLAG_RW, &fq_codel_sysctl.quantum, 1514, "FQ_CoDel quantum"); 146 SYSCTL_UINT(_net_inet_ip_dummynet_fqcodel, OID_AUTO, flows, 147 CTLFLAG_RW, &fq_codel_sysctl.flows_cnt, 1024, 148 "Number of queues for FQ_CoDel"); 149 SYSCTL_UINT(_net_inet_ip_dummynet_fqcodel, OID_AUTO, limit, 150 CTLFLAG_RW, &fq_codel_sysctl.limit, 10240, "FQ_CoDel queues size limit"); 151 #endif 152 153 /* Drop a packet form the head of codel queue */ 154 static void 155 codel_drop_head(struct fq_codel_flow *q, struct fq_codel_si *si) 156 { 157 struct mbuf *m = q->mq.head; 158 159 if (m == NULL) 160 return; 161 q->mq.head = m->m_nextpkt; 162 163 fq_update_stats(q, si, -m->m_pkthdr.len, 1); 164 165 if (si->main_q.ni.length == 0) /* queue is now idle */ 166 si->main_q.q_time = dn_cfg.curr_time; 167 168 FREE_PKT(m); 169 } 170 171 /* Enqueue a packet 'm' to a queue 'q' and add timestamp to that packet. 172 * Return 1 when unable to add timestamp, otherwise return 0 173 */ 174 static int 175 codel_enqueue(struct fq_codel_flow *q, struct mbuf *m, struct fq_codel_si *si) 176 { 177 uint64_t len; 178 179 len = m->m_pkthdr.len; 180 /* finding maximum packet size */ 181 if (len > q->cst.maxpkt_size) 182 q->cst.maxpkt_size = len; 183 184 /* Add timestamp to mbuf as MTAG */ 185 struct m_tag *mtag; 186 mtag = m_tag_locate(m, MTAG_ABI_COMPAT, DN_AQM_MTAG_TS, NULL); 187 if (mtag == NULL) 188 mtag = m_tag_alloc(MTAG_ABI_COMPAT, DN_AQM_MTAG_TS, sizeof(aqm_time_t), 189 M_NOWAIT); 190 if (mtag == NULL) { 191 m_freem(m); 192 goto drop; 193 } 194 *(aqm_time_t *)(mtag + 1) = AQM_UNOW; 195 m_tag_prepend(m, mtag); 196 197 mq_append(&q->mq, m); 198 fq_update_stats(q, si, len, 0); 199 return 0; 200 201 drop: 202 fq_update_stats(q, si, len, 1); 203 m_freem(m); 204 return 1; 205 } 206 207 /* 208 * Classify a packet to queue number using Jenkins hash function. 209 * Return: queue number 210 * the input of the hash are protocol no, perturbation, src IP, dst IP, 211 * src port, dst port, 212 */ 213 static inline int 214 fq_codel_classify_flow(struct mbuf *m, uint16_t fcount, struct fq_codel_si *si) 215 { 216 struct ip *ip; 217 struct tcphdr *th; 218 struct udphdr *uh; 219 uint8_t tuple[41]; 220 uint16_t hash=0; 221 222 ip = (struct ip *)mtodo(m, dn_tag_get(m)->iphdr_off); 223 //#ifdef INET6 224 struct ip6_hdr *ip6; 225 int isip6; 226 isip6 = (ip->ip_v == 6); 227 228 if(isip6) { 229 ip6 = (struct ip6_hdr *)ip; 230 *((uint8_t *) &tuple[0]) = ip6->ip6_nxt; 231 *((uint32_t *) &tuple[1]) = si->perturbation; 232 memcpy(&tuple[5], ip6->ip6_src.s6_addr, 16); 233 memcpy(&tuple[21], ip6->ip6_dst.s6_addr, 16); 234 235 switch (ip6->ip6_nxt) { 236 case IPPROTO_TCP: 237 th = (struct tcphdr *)(ip6 + 1); 238 *((uint16_t *) &tuple[37]) = th->th_dport; 239 *((uint16_t *) &tuple[39]) = th->th_sport; 240 break; 241 242 case IPPROTO_UDP: 243 uh = (struct udphdr *)(ip6 + 1); 244 *((uint16_t *) &tuple[37]) = uh->uh_dport; 245 *((uint16_t *) &tuple[39]) = uh->uh_sport; 246 break; 247 default: 248 memset(&tuple[37], 0, 4); 249 250 } 251 252 hash = jenkins_hash(tuple, 41, HASHINIT) % fcount; 253 return hash; 254 } 255 //#endif 256 257 /* IPv4 */ 258 *((uint8_t *) &tuple[0]) = ip->ip_p; 259 *((uint32_t *) &tuple[1]) = si->perturbation; 260 *((uint32_t *) &tuple[5]) = ip->ip_src.s_addr; 261 *((uint32_t *) &tuple[9]) = ip->ip_dst.s_addr; 262 263 switch (ip->ip_p) { 264 case IPPROTO_TCP: 265 th = (struct tcphdr *)(ip + 1); 266 *((uint16_t *) &tuple[13]) = th->th_dport; 267 *((uint16_t *) &tuple[15]) = th->th_sport; 268 break; 269 270 case IPPROTO_UDP: 271 uh = (struct udphdr *)(ip + 1); 272 *((uint16_t *) &tuple[13]) = uh->uh_dport; 273 *((uint16_t *) &tuple[15]) = uh->uh_sport; 274 break; 275 default: 276 memset(&tuple[13], 0, 4); 277 278 } 279 hash = jenkins_hash(tuple, 17, HASHINIT) % fcount; 280 281 return hash; 282 } 283 284 /* 285 * Enqueue a packet into an appropriate queue according to 286 * FQ_CODEL algorithm. 287 */ 288 static int 289 fq_codel_enqueue(struct dn_sch_inst *_si, struct dn_queue *_q, 290 struct mbuf *m) 291 { 292 struct fq_codel_si *si; 293 struct fq_codel_schk *schk; 294 struct dn_sch_fq_codel_parms *param; 295 struct dn_queue *mainq; 296 int idx, drop, i, maxidx; 297 298 mainq = (struct dn_queue *)(_si + 1); 299 si = (struct fq_codel_si *)_si; 300 schk = (struct fq_codel_schk *)(si->_si.sched+1); 301 param = &schk->cfg; 302 303 /* classify a packet to queue number*/ 304 idx = fq_codel_classify_flow(m, param->flows_cnt, si); 305 /* enqueue packet into appropriate queue using CoDel AQM. 306 * Note: 'codel_enqueue' function returns 1 only when it unable to 307 * add timestamp to packet (no limit check)*/ 308 drop = codel_enqueue(&si->flows[idx], m, si); 309 310 /* codel unable to timestamp a packet */ 311 if (drop) 312 return 1; 313 314 /* If the flow (sub-queue) is not active ,then add it to the tail of 315 * new flows list, initialize and activate it. 316 */ 317 if (!si->flows[idx].active ) { 318 STAILQ_INSERT_TAIL(&si->newflows, &si->flows[idx], flowchain); 319 si->flows[idx].deficit = param->quantum; 320 si->flows[idx].cst.dropping = false; 321 si->flows[idx].cst.first_above_time = 0; 322 si->flows[idx].active = 1; 323 //D("activate %d",idx); 324 } 325 326 /* check the limit for all queues and remove a packet from the 327 * largest one 328 */ 329 if (mainq->ni.length > schk->cfg.limit) { D("over limit"); 330 /* find first active flow */ 331 for (maxidx = 0; maxidx < schk->cfg.flows_cnt; maxidx++) 332 if (si->flows[maxidx].active) 333 break; 334 if (maxidx < schk->cfg.flows_cnt) { 335 /* find the largest sub- queue */ 336 for (i = maxidx + 1; i < schk->cfg.flows_cnt; i++) 337 if (si->flows[i].active && si->flows[i].stats.length > 338 si->flows[maxidx].stats.length) 339 maxidx = i; 340 codel_drop_head(&si->flows[maxidx], si); 341 D("maxidx = %d",maxidx); 342 drop = 1; 343 } 344 } 345 346 return drop; 347 } 348 349 /* 350 * Dequeue a packet from an appropriate queue according to 351 * FQ_CODEL algorithm. 352 */ 353 static struct mbuf * 354 fq_codel_dequeue(struct dn_sch_inst *_si) 355 { 356 struct fq_codel_si *si; 357 struct fq_codel_schk *schk; 358 struct dn_sch_fq_codel_parms *param; 359 struct fq_codel_flow *f; 360 struct mbuf *mbuf; 361 struct fq_codel_list *fq_codel_flowlist; 362 363 si = (struct fq_codel_si *)_si; 364 schk = (struct fq_codel_schk *)(si->_si.sched+1); 365 param = &schk->cfg; 366 367 do { 368 /* select a list to start with */ 369 if (STAILQ_EMPTY(&si->newflows)) 370 fq_codel_flowlist = &si->oldflows; 371 else 372 fq_codel_flowlist = &si->newflows; 373 374 /* Both new and old queue lists are empty, return NULL */ 375 if (STAILQ_EMPTY(fq_codel_flowlist)) 376 return NULL; 377 378 f = STAILQ_FIRST(fq_codel_flowlist); 379 while (f != NULL) { 380 /* if there is no flow(sub-queue) deficit, increase deficit 381 * by quantum, move the flow to the tail of old flows list 382 * and try another flow. 383 * Otherwise, the flow will be used for dequeue. 384 */ 385 if (f->deficit < 0) { 386 f->deficit += param->quantum; 387 STAILQ_REMOVE_HEAD(fq_codel_flowlist, flowchain); 388 STAILQ_INSERT_TAIL(&si->oldflows, f, flowchain); 389 } else 390 break; 391 392 f = STAILQ_FIRST(fq_codel_flowlist); 393 } 394 395 /* the new flows list is empty, try old flows list */ 396 if (STAILQ_EMPTY(fq_codel_flowlist)) 397 continue; 398 399 /* Dequeue a packet from the selected flow */ 400 mbuf = fqc_codel_dequeue(f, si); 401 402 /* Codel did not return a packet */ 403 if (!mbuf) { 404 /* If the selected flow belongs to new flows list, then move 405 * it to the tail of old flows list. Otherwise, deactivate it and 406 * remove it from the old list and 407 */ 408 if (fq_codel_flowlist == &si->newflows) { 409 STAILQ_REMOVE_HEAD(fq_codel_flowlist, flowchain); 410 STAILQ_INSERT_TAIL(&si->oldflows, f, flowchain); 411 } else { 412 f->active = 0; 413 STAILQ_REMOVE_HEAD(fq_codel_flowlist, flowchain); 414 } 415 /* start again */ 416 continue; 417 } 418 419 /* we have a packet to return, 420 * update flow deficit and return the packet*/ 421 f->deficit -= mbuf->m_pkthdr.len; 422 return mbuf; 423 424 } while (1); 425 426 /* unreachable point */ 427 return NULL; 428 } 429 430 /* 431 * Initialize fq_codel scheduler instance. 432 * also, allocate memory for flows array. 433 */ 434 static int 435 fq_codel_new_sched(struct dn_sch_inst *_si) 436 { 437 struct fq_codel_si *si; 438 struct dn_queue *q; 439 struct fq_codel_schk *schk; 440 int i; 441 442 si = (struct fq_codel_si *)_si; 443 schk = (struct fq_codel_schk *)(_si->sched+1); 444 445 if(si->flows) { 446 D("si already configured!"); 447 return 0; 448 } 449 450 /* init the main queue */ 451 q = &si->main_q; 452 set_oid(&q->ni.oid, DN_QUEUE, sizeof(*q)); 453 q->_si = _si; 454 q->fs = _si->sched->fs; 455 456 /* allocate memory for flows array */ 457 si->flows = mallocarray(schk->cfg.flows_cnt, 458 sizeof(struct fq_codel_flow), M_DUMMYNET, M_NOWAIT | M_ZERO); 459 if (si->flows == NULL) { 460 D("cannot allocate memory for fq_codel configuration parameters"); 461 return ENOMEM ; 462 } 463 464 /* init perturbation for this si */ 465 si->perturbation = random(); 466 467 /* init the old and new flows lists */ 468 STAILQ_INIT(&si->newflows); 469 STAILQ_INIT(&si->oldflows); 470 471 /* init the flows (sub-queues) */ 472 for (i = 0; i < schk->cfg.flows_cnt; i++) { 473 /* init codel */ 474 si->flows[i].cst.maxpkt_size = 500; 475 } 476 477 fq_codel_desc.ref_count++; 478 return 0; 479 } 480 481 /* 482 * Free fq_codel scheduler instance. 483 */ 484 static int 485 fq_codel_free_sched(struct dn_sch_inst *_si) 486 { 487 struct fq_codel_si *si = (struct fq_codel_si *)_si ; 488 489 /* free the flows array */ 490 free(si->flows , M_DUMMYNET); 491 si->flows = NULL; 492 fq_codel_desc.ref_count--; 493 494 return 0; 495 } 496 497 /* 498 * Configure fq_codel scheduler. 499 * the configurations for the scheduler is passed from userland. 500 */ 501 static int 502 fq_codel_config(struct dn_schk *_schk) 503 { 504 struct fq_codel_schk *schk; 505 struct dn_extra_parms *ep; 506 struct dn_sch_fq_codel_parms *fqc_cfg; 507 508 schk = (struct fq_codel_schk *)(_schk+1); 509 ep = (struct dn_extra_parms *) _schk->cfg; 510 511 /* par array contains fq_codel configuration as follow 512 * Codel: 0- target,1- interval, 2- flags 513 * FQ_CODEL: 3- quantum, 4- limit, 5- flows 514 */ 515 if (ep && ep->oid.len ==sizeof(*ep) && 516 ep->oid.subtype == DN_SCH_PARAMS) { 517 518 fqc_cfg = &schk->cfg; 519 if (ep->par[0] < 0) 520 fqc_cfg->ccfg.target = fq_codel_sysctl.ccfg.target; 521 else 522 fqc_cfg->ccfg.target = ep->par[0] * AQM_TIME_1US; 523 524 if (ep->par[1] < 0) 525 fqc_cfg->ccfg.interval = fq_codel_sysctl.ccfg.interval; 526 else 527 fqc_cfg->ccfg.interval = ep->par[1] * AQM_TIME_1US; 528 529 if (ep->par[2] < 0) 530 fqc_cfg->ccfg.flags = 0; 531 else 532 fqc_cfg->ccfg.flags = ep->par[2]; 533 534 /* FQ configurations */ 535 if (ep->par[3] < 0) 536 fqc_cfg->quantum = fq_codel_sysctl.quantum; 537 else 538 fqc_cfg->quantum = ep->par[3]; 539 540 if (ep->par[4] < 0) 541 fqc_cfg->limit = fq_codel_sysctl.limit; 542 else 543 fqc_cfg->limit = ep->par[4]; 544 545 if (ep->par[5] < 0) 546 fqc_cfg->flows_cnt = fq_codel_sysctl.flows_cnt; 547 else 548 fqc_cfg->flows_cnt = ep->par[5]; 549 550 /* Bound the configurations */ 551 fqc_cfg->ccfg.target = BOUND_VAR(fqc_cfg->ccfg.target, 1 , 552 5 * AQM_TIME_1S); ; 553 fqc_cfg->ccfg.interval = BOUND_VAR(fqc_cfg->ccfg.interval, 1, 554 100 * AQM_TIME_1S); 555 556 fqc_cfg->quantum = BOUND_VAR(fqc_cfg->quantum,1, 9000); 557 fqc_cfg->limit= BOUND_VAR(fqc_cfg->limit,1,20480); 558 fqc_cfg->flows_cnt= BOUND_VAR(fqc_cfg->flows_cnt,1,65536); 559 } 560 else 561 return 1; 562 563 return 0; 564 } 565 566 /* 567 * Return fq_codel scheduler configurations 568 * the configurations for the scheduler is passed to userland. 569 */ 570 static int 571 fq_codel_getconfig (struct dn_schk *_schk, struct dn_extra_parms *ep) { 572 573 struct fq_codel_schk *schk = (struct fq_codel_schk *)(_schk+1); 574 struct dn_sch_fq_codel_parms *fqc_cfg; 575 576 fqc_cfg = &schk->cfg; 577 578 strcpy(ep->name, fq_codel_desc.name); 579 ep->par[0] = fqc_cfg->ccfg.target / AQM_TIME_1US; 580 ep->par[1] = fqc_cfg->ccfg.interval / AQM_TIME_1US; 581 ep->par[2] = fqc_cfg->ccfg.flags; 582 583 ep->par[3] = fqc_cfg->quantum; 584 ep->par[4] = fqc_cfg->limit; 585 ep->par[5] = fqc_cfg->flows_cnt; 586 587 return 0; 588 } 589 590 /* 591 * fq_codel scheduler descriptor 592 * contains the type of the scheduler, the name, the size of extra 593 * data structures, and function pointers. 594 */ 595 static struct dn_alg fq_codel_desc = { 596 _SI( .type = ) DN_SCHED_FQ_CODEL, 597 _SI( .name = ) "FQ_CODEL", 598 _SI( .flags = ) 0, 599 600 _SI( .schk_datalen = ) sizeof(struct fq_codel_schk), 601 _SI( .si_datalen = ) sizeof(struct fq_codel_si) - sizeof(struct dn_sch_inst), 602 _SI( .q_datalen = ) 0, 603 604 _SI( .enqueue = ) fq_codel_enqueue, 605 _SI( .dequeue = ) fq_codel_dequeue, 606 _SI( .config = ) fq_codel_config, /* new sched i.e. sched X config ...*/ 607 _SI( .destroy = ) NULL, /*sched x delete */ 608 _SI( .new_sched = ) fq_codel_new_sched, /* new schd instance */ 609 _SI( .free_sched = ) fq_codel_free_sched, /* delete schd instance */ 610 _SI( .new_fsk = ) NULL, 611 _SI( .free_fsk = ) NULL, 612 _SI( .new_queue = ) NULL, 613 _SI( .free_queue = ) NULL, 614 _SI( .getconfig = ) fq_codel_getconfig, 615 _SI( .ref_count = ) 0 616 }; 617 618 DECLARE_DNSCHED_MODULE(dn_fq_codel, &fq_codel_desc); 619