1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2010 Luigi Rizzo, Riccardo Panicucci, Universita` di Pisa 5 * All rights reserved 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 /* 30 * Dummynet portions related to packet handling. 31 */ 32 #include <sys/cdefs.h> 33 __FBSDID("$FreeBSD$"); 34 35 #include "opt_inet6.h" 36 37 #include <sys/param.h> 38 #include <sys/systm.h> 39 #include <sys/malloc.h> 40 #include <sys/mbuf.h> 41 #include <sys/kernel.h> 42 #include <sys/lock.h> 43 #include <sys/module.h> 44 #include <sys/mutex.h> 45 #include <sys/priv.h> 46 #include <sys/proc.h> 47 #include <sys/rwlock.h> 48 #include <sys/socket.h> 49 #include <sys/time.h> 50 #include <sys/sysctl.h> 51 52 #include <net/if.h> /* IFNAMSIZ, struct ifaddr, ifq head, lock.h mutex.h */ 53 #include <net/if_var.h> /* NET_EPOCH_... */ 54 #include <net/netisr.h> 55 #include <net/vnet.h> 56 57 #include <netinet/in.h> 58 #include <netinet/ip.h> /* ip_len, ip_off */ 59 #include <netinet/ip_var.h> /* ip_output(), IP_FORWARDING */ 60 #include <netinet/ip_fw.h> 61 #include <netinet/ip_dummynet.h> 62 #include <netinet/if_ether.h> /* various ether_* routines */ 63 #include <netinet/ip6.h> /* for ip6_input, ip6_output prototypes */ 64 #include <netinet6/ip6_var.h> 65 66 #include <netpfil/ipfw/ip_fw_private.h> 67 #include <netpfil/ipfw/dn_heap.h> 68 #include <netpfil/ipfw/ip_dn_private.h> 69 #ifdef NEW_AQM 70 #include <netpfil/ipfw/dn_aqm.h> 71 #endif 72 #include <netpfil/ipfw/dn_sched.h> 73 74 /* 75 * We keep a private variable for the simulation time, but we could 76 * probably use an existing one ("softticks" in sys/kern/kern_timeout.c) 77 * instead of dn_cfg.curr_time 78 */ 79 80 struct dn_parms dn_cfg; 81 //VNET_DEFINE(struct dn_parms, _base_dn_cfg); 82 83 static long tick_last; /* Last tick duration (usec). */ 84 static long tick_delta; /* Last vs standard tick diff (usec). */ 85 static long tick_delta_sum; /* Accumulated tick difference (usec).*/ 86 static long tick_adjustment; /* Tick adjustments done. */ 87 static long tick_lost; /* Lost(coalesced) ticks number. */ 88 /* Adjusted vs non-adjusted curr_time difference (ticks). */ 89 static long tick_diff; 90 91 static unsigned long io_pkt; 92 static unsigned long io_pkt_fast; 93 94 #ifdef NEW_AQM 95 unsigned long io_pkt_drop; 96 #else 97 static unsigned long io_pkt_drop; 98 #endif 99 /* 100 * We use a heap to store entities for which we have pending timer events. 101 * The heap is checked at every tick and all entities with expired events 102 * are extracted. 103 */ 104 105 MALLOC_DEFINE(M_DUMMYNET, "dummynet", "dummynet heap"); 106 107 extern void (*bridge_dn_p)(struct mbuf *, struct ifnet *); 108 109 #ifdef SYSCTL_NODE 110 111 /* 112 * Because of the way the SYSBEGIN/SYSEND macros work on other 113 * platforms, there should not be functions between them. 114 * So keep the handlers outside the block. 115 */ 116 static int 117 sysctl_hash_size(SYSCTL_HANDLER_ARGS) 118 { 119 int error, value; 120 121 value = dn_cfg.hash_size; 122 error = sysctl_handle_int(oidp, &value, 0, req); 123 if (error != 0 || req->newptr == NULL) 124 return (error); 125 if (value < 16 || value > 65536) 126 return (EINVAL); 127 dn_cfg.hash_size = value; 128 return (0); 129 } 130 131 static int 132 sysctl_limits(SYSCTL_HANDLER_ARGS) 133 { 134 int error; 135 long value; 136 137 if (arg2 != 0) 138 value = dn_cfg.slot_limit; 139 else 140 value = dn_cfg.byte_limit; 141 error = sysctl_handle_long(oidp, &value, 0, req); 142 143 if (error != 0 || req->newptr == NULL) 144 return (error); 145 if (arg2 != 0) { 146 if (value < 1) 147 return (EINVAL); 148 dn_cfg.slot_limit = value; 149 } else { 150 if (value < 1500) 151 return (EINVAL); 152 dn_cfg.byte_limit = value; 153 } 154 return (0); 155 } 156 157 SYSBEGIN(f4) 158 159 SYSCTL_DECL(_net_inet); 160 SYSCTL_DECL(_net_inet_ip); 161 #ifdef NEW_AQM 162 SYSCTL_NODE(_net_inet_ip, OID_AUTO, dummynet, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 163 "Dummynet"); 164 #else 165 static SYSCTL_NODE(_net_inet_ip, OID_AUTO, dummynet, 166 CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 167 "Dummynet"); 168 #endif 169 170 /* wrapper to pass dn_cfg fields to SYSCTL_* */ 171 //#define DC(x) (&(VNET_NAME(_base_dn_cfg).x)) 172 #define DC(x) (&(dn_cfg.x)) 173 /* parameters */ 174 175 SYSCTL_PROC(_net_inet_ip_dummynet, OID_AUTO, hash_size, 176 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 177 0, 0, sysctl_hash_size, "I", 178 "Default hash table size"); 179 180 SYSCTL_PROC(_net_inet_ip_dummynet, OID_AUTO, pipe_slot_limit, 181 CTLTYPE_LONG | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 182 0, 1, sysctl_limits, "L", 183 "Upper limit in slots for pipe queue."); 184 SYSCTL_PROC(_net_inet_ip_dummynet, OID_AUTO, pipe_byte_limit, 185 CTLTYPE_LONG | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 186 0, 0, sysctl_limits, "L", 187 "Upper limit in bytes for pipe queue."); 188 SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, io_fast, 189 CTLFLAG_RW, DC(io_fast), 0, "Enable fast dummynet io."); 190 SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, debug, 191 CTLFLAG_RW, DC(debug), 0, "Dummynet debug level"); 192 193 /* RED parameters */ 194 SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, red_lookup_depth, 195 CTLFLAG_RD, DC(red_lookup_depth), 0, "Depth of RED lookup table"); 196 SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, red_avg_pkt_size, 197 CTLFLAG_RD, DC(red_avg_pkt_size), 0, "RED Medium packet size"); 198 SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, red_max_pkt_size, 199 CTLFLAG_RD, DC(red_max_pkt_size), 0, "RED Max packet size"); 200 201 /* time adjustment */ 202 SYSCTL_LONG(_net_inet_ip_dummynet, OID_AUTO, tick_delta, 203 CTLFLAG_RD, &tick_delta, 0, "Last vs standard tick difference (usec)."); 204 SYSCTL_LONG(_net_inet_ip_dummynet, OID_AUTO, tick_delta_sum, 205 CTLFLAG_RD, &tick_delta_sum, 0, "Accumulated tick difference (usec)."); 206 SYSCTL_LONG(_net_inet_ip_dummynet, OID_AUTO, tick_adjustment, 207 CTLFLAG_RD, &tick_adjustment, 0, "Tick adjustments done."); 208 SYSCTL_LONG(_net_inet_ip_dummynet, OID_AUTO, tick_diff, 209 CTLFLAG_RD, &tick_diff, 0, 210 "Adjusted vs non-adjusted curr_time difference (ticks)."); 211 SYSCTL_LONG(_net_inet_ip_dummynet, OID_AUTO, tick_lost, 212 CTLFLAG_RD, &tick_lost, 0, 213 "Number of ticks coalesced by dummynet taskqueue."); 214 215 /* Drain parameters */ 216 SYSCTL_UINT(_net_inet_ip_dummynet, OID_AUTO, expire, 217 CTLFLAG_RW, DC(expire), 0, "Expire empty queues/pipes"); 218 SYSCTL_UINT(_net_inet_ip_dummynet, OID_AUTO, expire_cycle, 219 CTLFLAG_RD, DC(expire_cycle), 0, "Expire cycle for queues/pipes"); 220 221 /* statistics */ 222 SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, schk_count, 223 CTLFLAG_RD, DC(schk_count), 0, "Number of schedulers"); 224 SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, si_count, 225 CTLFLAG_RD, DC(si_count), 0, "Number of scheduler instances"); 226 SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, fsk_count, 227 CTLFLAG_RD, DC(fsk_count), 0, "Number of flowsets"); 228 SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, queue_count, 229 CTLFLAG_RD, DC(queue_count), 0, "Number of queues"); 230 SYSCTL_ULONG(_net_inet_ip_dummynet, OID_AUTO, io_pkt, 231 CTLFLAG_RD, &io_pkt, 0, 232 "Number of packets passed to dummynet."); 233 SYSCTL_ULONG(_net_inet_ip_dummynet, OID_AUTO, io_pkt_fast, 234 CTLFLAG_RD, &io_pkt_fast, 0, 235 "Number of packets bypassed dummynet scheduler."); 236 SYSCTL_ULONG(_net_inet_ip_dummynet, OID_AUTO, io_pkt_drop, 237 CTLFLAG_RD, &io_pkt_drop, 0, 238 "Number of packets dropped by dummynet."); 239 #undef DC 240 SYSEND 241 242 #endif 243 244 static void dummynet_send(struct mbuf *); 245 246 /* 247 * Return the mbuf tag holding the dummynet state (it should 248 * be the first one on the list). 249 */ 250 struct dn_pkt_tag * 251 dn_tag_get(struct mbuf *m) 252 { 253 struct m_tag *mtag = m_tag_first(m); 254 #ifdef NEW_AQM 255 /* XXX: to skip ts m_tag. For Debugging only*/ 256 if (mtag != NULL && mtag->m_tag_id == DN_AQM_MTAG_TS) { 257 m_tag_delete(m,mtag); 258 mtag = m_tag_first(m); 259 D("skip TS tag"); 260 } 261 #endif 262 KASSERT(mtag != NULL && 263 mtag->m_tag_cookie == MTAG_ABI_COMPAT && 264 mtag->m_tag_id == PACKET_TAG_DUMMYNET, 265 ("packet on dummynet queue w/o dummynet tag!")); 266 return (struct dn_pkt_tag *)(mtag+1); 267 } 268 269 #ifndef NEW_AQM 270 static inline void 271 mq_append(struct mq *q, struct mbuf *m) 272 { 273 #ifdef USERSPACE 274 // buffers from netmap need to be copied 275 // XXX note that the routine is not expected to fail 276 ND("append %p to %p", m, q); 277 if (m->m_flags & M_STACK) { 278 struct mbuf *m_new; 279 void *p; 280 int l, ofs; 281 282 ofs = m->m_data - m->__m_extbuf; 283 // XXX allocate 284 MGETHDR(m_new, M_NOWAIT, MT_DATA); 285 ND("*** WARNING, volatile buf %p ext %p %d dofs %d m_new %p", 286 m, m->__m_extbuf, m->__m_extlen, ofs, m_new); 287 p = m_new->__m_extbuf; /* new pointer */ 288 l = m_new->__m_extlen; /* new len */ 289 if (l <= m->__m_extlen) { 290 panic("extlen too large"); 291 } 292 293 *m_new = *m; // copy 294 m_new->m_flags &= ~M_STACK; 295 m_new->__m_extbuf = p; // point to new buffer 296 _pkt_copy(m->__m_extbuf, p, m->__m_extlen); 297 m_new->m_data = p + ofs; 298 m = m_new; 299 } 300 #endif /* USERSPACE */ 301 if (q->head == NULL) 302 q->head = m; 303 else 304 q->tail->m_nextpkt = m; 305 q->count++; 306 q->tail = m; 307 m->m_nextpkt = NULL; 308 } 309 #endif 310 311 /* 312 * Dispose a list of packet. Use a functions so if we need to do 313 * more work, this is a central point to do it. 314 */ 315 void dn_free_pkts(struct mbuf *mnext) 316 { 317 struct mbuf *m; 318 319 while ((m = mnext) != NULL) { 320 mnext = m->m_nextpkt; 321 FREE_PKT(m); 322 } 323 } 324 325 static int 326 red_drops (struct dn_queue *q, int len) 327 { 328 /* 329 * RED algorithm 330 * 331 * RED calculates the average queue size (avg) using a low-pass filter 332 * with an exponential weighted (w_q) moving average: 333 * avg <- (1-w_q) * avg + w_q * q_size 334 * where q_size is the queue length (measured in bytes or * packets). 335 * 336 * If q_size == 0, we compute the idle time for the link, and set 337 * avg = (1 - w_q)^(idle/s) 338 * where s is the time needed for transmitting a medium-sized packet. 339 * 340 * Now, if avg < min_th the packet is enqueued. 341 * If avg > max_th the packet is dropped. Otherwise, the packet is 342 * dropped with probability P function of avg. 343 */ 344 345 struct dn_fsk *fs = q->fs; 346 int64_t p_b = 0; 347 348 /* Queue in bytes or packets? */ 349 uint32_t q_size = (fs->fs.flags & DN_QSIZE_BYTES) ? 350 q->ni.len_bytes : q->ni.length; 351 352 /* Average queue size estimation. */ 353 if (q_size != 0) { 354 /* Queue is not empty, avg <- avg + (q_size - avg) * w_q */ 355 int diff = SCALE(q_size) - q->avg; 356 int64_t v = SCALE_MUL((int64_t)diff, (int64_t)fs->w_q); 357 358 q->avg += (int)v; 359 } else { 360 /* 361 * Queue is empty, find for how long the queue has been 362 * empty and use a lookup table for computing 363 * (1 - * w_q)^(idle_time/s) where s is the time to send a 364 * (small) packet. 365 * XXX check wraps... 366 */ 367 if (q->avg) { 368 u_int t = div64((dn_cfg.curr_time - q->q_time), fs->lookup_step); 369 370 q->avg = (t < fs->lookup_depth) ? 371 SCALE_MUL(q->avg, fs->w_q_lookup[t]) : 0; 372 } 373 } 374 375 /* Should i drop? */ 376 if (q->avg < fs->min_th) { 377 q->count = -1; 378 return (0); /* accept packet */ 379 } 380 if (q->avg >= fs->max_th) { /* average queue >= max threshold */ 381 if (fs->fs.flags & DN_IS_ECN) 382 return (1); 383 if (fs->fs.flags & DN_IS_GENTLE_RED) { 384 /* 385 * According to Gentle-RED, if avg is greater than 386 * max_th the packet is dropped with a probability 387 * p_b = c_3 * avg - c_4 388 * where c_3 = (1 - max_p) / max_th 389 * c_4 = 1 - 2 * max_p 390 */ 391 p_b = SCALE_MUL((int64_t)fs->c_3, (int64_t)q->avg) - 392 fs->c_4; 393 } else { 394 q->count = -1; 395 return (1); 396 } 397 } else if (q->avg > fs->min_th) { 398 if (fs->fs.flags & DN_IS_ECN) 399 return (1); 400 /* 401 * We compute p_b using the linear dropping function 402 * p_b = c_1 * avg - c_2 403 * where c_1 = max_p / (max_th - min_th) 404 * c_2 = max_p * min_th / (max_th - min_th) 405 */ 406 p_b = SCALE_MUL((int64_t)fs->c_1, (int64_t)q->avg) - fs->c_2; 407 } 408 409 if (fs->fs.flags & DN_QSIZE_BYTES) 410 p_b = div64((p_b * len) , fs->max_pkt_size); 411 if (++q->count == 0) 412 q->random = random() & 0xffff; 413 else { 414 /* 415 * q->count counts packets arrived since last drop, so a greater 416 * value of q->count means a greater packet drop probability. 417 */ 418 if (SCALE_MUL(p_b, SCALE((int64_t)q->count)) > q->random) { 419 q->count = 0; 420 /* After a drop we calculate a new random value. */ 421 q->random = random() & 0xffff; 422 return (1); /* drop */ 423 } 424 } 425 /* End of RED algorithm. */ 426 427 return (0); /* accept */ 428 429 } 430 431 /* 432 * ECN/ECT Processing (partially adopted from altq) 433 */ 434 #ifndef NEW_AQM 435 static 436 #endif 437 int 438 ecn_mark(struct mbuf* m) 439 { 440 struct ip *ip; 441 ip = (struct ip *)mtodo(m, dn_tag_get(m)->iphdr_off); 442 443 switch (ip->ip_v) { 444 case IPVERSION: 445 { 446 uint16_t old; 447 448 if ((ip->ip_tos & IPTOS_ECN_MASK) == IPTOS_ECN_NOTECT) 449 return (0); /* not-ECT */ 450 if ((ip->ip_tos & IPTOS_ECN_MASK) == IPTOS_ECN_CE) 451 return (1); /* already marked */ 452 453 /* 454 * ecn-capable but not marked, 455 * mark CE and update checksum 456 */ 457 old = *(uint16_t *)ip; 458 ip->ip_tos |= IPTOS_ECN_CE; 459 ip->ip_sum = cksum_adjust(ip->ip_sum, old, *(uint16_t *)ip); 460 return (1); 461 } 462 #ifdef INET6 463 case (IPV6_VERSION >> 4): 464 { 465 struct ip6_hdr *ip6 = (struct ip6_hdr *)ip; 466 u_int32_t flowlabel; 467 468 flowlabel = ntohl(ip6->ip6_flow); 469 if ((flowlabel >> 28) != 6) 470 return (0); /* version mismatch! */ 471 if ((flowlabel & (IPTOS_ECN_MASK << 20)) == 472 (IPTOS_ECN_NOTECT << 20)) 473 return (0); /* not-ECT */ 474 if ((flowlabel & (IPTOS_ECN_MASK << 20)) == 475 (IPTOS_ECN_CE << 20)) 476 return (1); /* already marked */ 477 /* 478 * ecn-capable but not marked, mark CE 479 */ 480 flowlabel |= (IPTOS_ECN_CE << 20); 481 ip6->ip6_flow = htonl(flowlabel); 482 return (1); 483 } 484 #endif 485 } 486 return (0); 487 } 488 489 /* 490 * Enqueue a packet in q, subject to space and queue management policy 491 * (whose parameters are in q->fs). 492 * Update stats for the queue and the scheduler. 493 * Return 0 on success, 1 on drop. The packet is consumed anyways. 494 */ 495 int 496 dn_enqueue(struct dn_queue *q, struct mbuf* m, int drop) 497 { 498 struct dn_fs *f; 499 struct dn_flow *ni; /* stats for scheduler instance */ 500 uint64_t len; 501 502 if (q->fs == NULL || q->_si == NULL) { 503 printf("%s fs %p si %p, dropping\n", 504 __FUNCTION__, q->fs, q->_si); 505 FREE_PKT(m); 506 return 1; 507 } 508 f = &(q->fs->fs); 509 ni = &q->_si->ni; 510 len = m->m_pkthdr.len; 511 /* Update statistics, then check reasons to drop pkt. */ 512 q->ni.tot_bytes += len; 513 q->ni.tot_pkts++; 514 ni->tot_bytes += len; 515 ni->tot_pkts++; 516 if (drop) 517 goto drop; 518 if (f->plr && random() < f->plr) 519 goto drop; 520 #ifdef NEW_AQM 521 /* Call AQM enqueue function */ 522 if (q->fs->aqmfp) 523 return q->fs->aqmfp->enqueue(q ,m); 524 #endif 525 if (f->flags & DN_IS_RED && red_drops(q, m->m_pkthdr.len)) { 526 if (!(f->flags & DN_IS_ECN) || !ecn_mark(m)) 527 goto drop; 528 } 529 if (f->flags & DN_QSIZE_BYTES) { 530 if (q->ni.len_bytes > f->qsize) 531 goto drop; 532 } else if (q->ni.length >= f->qsize) { 533 goto drop; 534 } 535 mq_append(&q->mq, m); 536 q->ni.length++; 537 q->ni.len_bytes += len; 538 ni->length++; 539 ni->len_bytes += len; 540 return (0); 541 542 drop: 543 io_pkt_drop++; 544 q->ni.drops++; 545 ni->drops++; 546 FREE_PKT(m); 547 return (1); 548 } 549 550 /* 551 * Fetch packets from the delay line which are due now. If there are 552 * leftover packets, reinsert the delay line in the heap. 553 * Runs under scheduler lock. 554 */ 555 static void 556 transmit_event(struct mq *q, struct delay_line *dline, uint64_t now) 557 { 558 struct mbuf *m; 559 struct dn_pkt_tag *pkt = NULL; 560 561 dline->oid.subtype = 0; /* not in heap */ 562 while ((m = dline->mq.head) != NULL) { 563 pkt = dn_tag_get(m); 564 if (!DN_KEY_LEQ(pkt->output_time, now)) 565 break; 566 dline->mq.head = m->m_nextpkt; 567 dline->mq.count--; 568 mq_append(q, m); 569 } 570 if (m != NULL) { 571 dline->oid.subtype = 1; /* in heap */ 572 heap_insert(&dn_cfg.evheap, pkt->output_time, dline); 573 } 574 } 575 576 /* 577 * Convert the additional MAC overheads/delays into an equivalent 578 * number of bits for the given data rate. The samples are 579 * in milliseconds so we need to divide by 1000. 580 */ 581 static uint64_t 582 extra_bits(struct mbuf *m, struct dn_schk *s) 583 { 584 int index; 585 uint64_t bits; 586 struct dn_profile *pf = s->profile; 587 588 if (!pf || pf->samples_no == 0) 589 return 0; 590 index = random() % pf->samples_no; 591 bits = div64((uint64_t)pf->samples[index] * s->link.bandwidth, 1000); 592 if (index >= pf->loss_level) { 593 struct dn_pkt_tag *dt = dn_tag_get(m); 594 if (dt) 595 dt->dn_dir = DIR_DROP; 596 } 597 return bits; 598 } 599 600 /* 601 * Send traffic from a scheduler instance due by 'now'. 602 * Return a pointer to the head of the queue. 603 */ 604 static struct mbuf * 605 serve_sched(struct mq *q, struct dn_sch_inst *si, uint64_t now) 606 { 607 struct mq def_q; 608 struct dn_schk *s = si->sched; 609 struct mbuf *m = NULL; 610 int delay_line_idle = (si->dline.mq.head == NULL); 611 int done, bw; 612 613 if (q == NULL) { 614 q = &def_q; 615 q->head = NULL; 616 } 617 618 bw = s->link.bandwidth; 619 si->kflags &= ~DN_ACTIVE; 620 621 if (bw > 0) 622 si->credit += (now - si->sched_time) * bw; 623 else 624 si->credit = 0; 625 si->sched_time = now; 626 done = 0; 627 while (si->credit >= 0 && (m = s->fp->dequeue(si)) != NULL) { 628 uint64_t len_scaled; 629 630 done++; 631 len_scaled = (bw == 0) ? 0 : hz * 632 (m->m_pkthdr.len * 8 + extra_bits(m, s)); 633 si->credit -= len_scaled; 634 /* Move packet in the delay line */ 635 dn_tag_get(m)->output_time = dn_cfg.curr_time + s->link.delay ; 636 mq_append(&si->dline.mq, m); 637 } 638 639 /* 640 * If credit >= 0 the instance is idle, mark time. 641 * Otherwise put back in the heap, and adjust the output 642 * time of the last inserted packet, m, which was too early. 643 */ 644 if (si->credit >= 0) { 645 si->idle_time = now; 646 } else { 647 uint64_t t; 648 KASSERT (bw > 0, ("bw=0 and credit<0 ?")); 649 t = div64(bw - 1 - si->credit, bw); 650 if (m) 651 dn_tag_get(m)->output_time += t; 652 si->kflags |= DN_ACTIVE; 653 heap_insert(&dn_cfg.evheap, now + t, si); 654 } 655 if (delay_line_idle && done) 656 transmit_event(q, &si->dline, now); 657 return q->head; 658 } 659 660 /* 661 * The timer handler for dummynet. Time is computed in ticks, but 662 * but the code is tolerant to the actual rate at which this is called. 663 * Once complete, the function reschedules itself for the next tick. 664 */ 665 void 666 dummynet_task(void *context, int pending) 667 { 668 struct timeval t; 669 struct mq q = { NULL, NULL }; /* queue to accumulate results */ 670 671 CURVNET_SET((struct vnet *)context); 672 673 DN_BH_WLOCK(); 674 675 /* Update number of lost(coalesced) ticks. */ 676 tick_lost += pending - 1; 677 678 getmicrouptime(&t); 679 /* Last tick duration (usec). */ 680 tick_last = (t.tv_sec - dn_cfg.prev_t.tv_sec) * 1000000 + 681 (t.tv_usec - dn_cfg.prev_t.tv_usec); 682 /* Last tick vs standard tick difference (usec). */ 683 tick_delta = (tick_last * hz - 1000000) / hz; 684 /* Accumulated tick difference (usec). */ 685 tick_delta_sum += tick_delta; 686 687 dn_cfg.prev_t = t; 688 689 /* 690 * Adjust curr_time if the accumulated tick difference is 691 * greater than the 'standard' tick. Since curr_time should 692 * be monotonically increasing, we do positive adjustments 693 * as required, and throttle curr_time in case of negative 694 * adjustment. 695 */ 696 dn_cfg.curr_time++; 697 if (tick_delta_sum - tick >= 0) { 698 int diff = tick_delta_sum / tick; 699 700 dn_cfg.curr_time += diff; 701 tick_diff += diff; 702 tick_delta_sum %= tick; 703 tick_adjustment++; 704 } else if (tick_delta_sum + tick <= 0) { 705 dn_cfg.curr_time--; 706 tick_diff--; 707 tick_delta_sum += tick; 708 tick_adjustment++; 709 } 710 711 /* serve pending events, accumulate in q */ 712 for (;;) { 713 struct dn_id *p; /* generic parameter to handler */ 714 715 if (dn_cfg.evheap.elements == 0 || 716 DN_KEY_LT(dn_cfg.curr_time, HEAP_TOP(&dn_cfg.evheap)->key)) 717 break; 718 p = HEAP_TOP(&dn_cfg.evheap)->object; 719 heap_extract(&dn_cfg.evheap, NULL); 720 721 if (p->type == DN_SCH_I) { 722 serve_sched(&q, (struct dn_sch_inst *)p, dn_cfg.curr_time); 723 } else { /* extracted a delay line */ 724 transmit_event(&q, (struct delay_line *)p, dn_cfg.curr_time); 725 } 726 } 727 if (dn_cfg.expire && ++dn_cfg.expire_cycle >= dn_cfg.expire) { 728 dn_cfg.expire_cycle = 0; 729 dn_drain_scheduler(); 730 dn_drain_queue(); 731 } 732 733 dn_reschedule(); 734 DN_BH_WUNLOCK(); 735 if (q.head != NULL) 736 dummynet_send(q.head); 737 CURVNET_RESTORE(); 738 } 739 740 /* 741 * forward a chain of packets to the proper destination. 742 * This runs outside the dummynet lock. 743 */ 744 static void 745 dummynet_send(struct mbuf *m) 746 { 747 struct mbuf *n; 748 749 NET_EPOCH_ASSERT(); 750 751 for (; m != NULL; m = n) { 752 struct ifnet *ifp = NULL; /* gcc 3.4.6 complains */ 753 struct m_tag *tag; 754 int dst; 755 756 n = m->m_nextpkt; 757 m->m_nextpkt = NULL; 758 tag = m_tag_first(m); 759 if (tag == NULL) { /* should not happen */ 760 dst = DIR_DROP; 761 } else { 762 struct dn_pkt_tag *pkt = dn_tag_get(m); 763 /* extract the dummynet info, rename the tag 764 * to carry reinject info. 765 */ 766 if (pkt->dn_dir == (DIR_OUT | PROTO_LAYER2) && 767 pkt->ifp == NULL) { 768 dst = DIR_DROP; 769 } else { 770 dst = pkt->dn_dir; 771 ifp = pkt->ifp; 772 tag->m_tag_cookie = MTAG_IPFW_RULE; 773 tag->m_tag_id = 0; 774 } 775 } 776 777 switch (dst) { 778 case DIR_OUT: 779 ip_output(m, NULL, NULL, IP_FORWARDING, NULL, NULL); 780 break ; 781 782 case DIR_IN : 783 netisr_dispatch(NETISR_IP, m); 784 break; 785 786 #ifdef INET6 787 case DIR_IN | PROTO_IPV6: 788 netisr_dispatch(NETISR_IPV6, m); 789 break; 790 791 case DIR_OUT | PROTO_IPV6: 792 ip6_output(m, NULL, NULL, IPV6_FORWARDING, NULL, NULL, NULL); 793 break; 794 #endif 795 796 case DIR_FWD | PROTO_IFB: /* DN_TO_IFB_FWD: */ 797 if (bridge_dn_p != NULL) 798 ((*bridge_dn_p)(m, ifp)); 799 else 800 printf("dummynet: if_bridge not loaded\n"); 801 802 break; 803 804 case DIR_IN | PROTO_LAYER2: /* DN_TO_ETH_DEMUX: */ 805 /* 806 * The Ethernet code assumes the Ethernet header is 807 * contiguous in the first mbuf header. 808 * Insure this is true. 809 */ 810 if (m->m_len < ETHER_HDR_LEN && 811 (m = m_pullup(m, ETHER_HDR_LEN)) == NULL) { 812 printf("dummynet/ether: pullup failed, " 813 "dropping packet\n"); 814 break; 815 } 816 ether_demux(m->m_pkthdr.rcvif, m); 817 break; 818 819 case DIR_OUT | PROTO_LAYER2: /* DN_TO_ETH_OUT: */ 820 ether_output_frame(ifp, m); 821 break; 822 823 case DIR_DROP: 824 /* drop the packet after some time */ 825 FREE_PKT(m); 826 break; 827 828 default: 829 printf("dummynet: bad switch %d!\n", dst); 830 FREE_PKT(m); 831 break; 832 } 833 } 834 } 835 836 static inline int 837 tag_mbuf(struct mbuf *m, int dir, struct ip_fw_args *fwa) 838 { 839 struct dn_pkt_tag *dt; 840 struct m_tag *mtag; 841 842 mtag = m_tag_get(PACKET_TAG_DUMMYNET, 843 sizeof(*dt), M_NOWAIT | M_ZERO); 844 if (mtag == NULL) 845 return 1; /* Cannot allocate packet header. */ 846 m_tag_prepend(m, mtag); /* Attach to mbuf chain. */ 847 dt = (struct dn_pkt_tag *)(mtag + 1); 848 dt->rule = fwa->rule; 849 dt->rule.info &= IPFW_ONEPASS; /* only keep this info */ 850 dt->dn_dir = dir; 851 dt->ifp = fwa->flags & IPFW_ARGS_OUT ? fwa->ifp : NULL; 852 /* dt->output tame is updated as we move through */ 853 dt->output_time = dn_cfg.curr_time; 854 dt->iphdr_off = (dir & PROTO_LAYER2) ? ETHER_HDR_LEN : 0; 855 return 0; 856 } 857 858 /* 859 * dummynet hook for packets. 860 * We use the argument to locate the flowset fs and the sched_set sch 861 * associated to it. The we apply flow_mask and sched_mask to 862 * determine the queue and scheduler instances. 863 */ 864 int 865 dummynet_io(struct mbuf **m0, struct ip_fw_args *fwa) 866 { 867 struct mbuf *m = *m0; 868 struct dn_fsk *fs = NULL; 869 struct dn_sch_inst *si; 870 struct dn_queue *q = NULL; /* default */ 871 int fs_id, dir; 872 873 fs_id = (fwa->rule.info & IPFW_INFO_MASK) + 874 ((fwa->rule.info & IPFW_IS_PIPE) ? 2*DN_MAX_ID : 0); 875 /* XXXGL: convert args to dir */ 876 if (fwa->flags & IPFW_ARGS_IN) 877 dir = DIR_IN; 878 else 879 dir = DIR_OUT; 880 if (fwa->flags & IPFW_ARGS_ETHER) 881 dir |= PROTO_LAYER2; 882 else if (fwa->flags & IPFW_ARGS_IP6) 883 dir |= PROTO_IPV6; 884 DN_BH_WLOCK(); 885 io_pkt++; 886 /* we could actually tag outside the lock, but who cares... */ 887 if (tag_mbuf(m, dir, fwa)) 888 goto dropit; 889 if (dn_cfg.busy) { 890 /* if the upper half is busy doing something expensive, 891 * lets queue the packet and move forward 892 */ 893 mq_append(&dn_cfg.pending, m); 894 m = *m0 = NULL; /* consumed */ 895 goto done; /* already active, nothing to do */ 896 } 897 /* XXX locate_flowset could be optimised with a direct ref. */ 898 fs = dn_ht_find(dn_cfg.fshash, fs_id, 0, NULL); 899 if (fs == NULL) 900 goto dropit; /* This queue/pipe does not exist! */ 901 if (fs->sched == NULL) /* should not happen */ 902 goto dropit; 903 /* find scheduler instance, possibly applying sched_mask */ 904 si = ipdn_si_find(fs->sched, &(fwa->f_id)); 905 if (si == NULL) 906 goto dropit; 907 /* 908 * If the scheduler supports multiple queues, find the right one 909 * (otherwise it will be ignored by enqueue). 910 */ 911 if (fs->sched->fp->flags & DN_MULTIQUEUE) { 912 q = ipdn_q_find(fs, si, &(fwa->f_id)); 913 if (q == NULL) 914 goto dropit; 915 } 916 if (fs->sched->fp->enqueue(si, q, m)) { 917 /* packet was dropped by enqueue() */ 918 m = *m0 = NULL; 919 920 /* dn_enqueue already increases io_pkt_drop */ 921 io_pkt_drop--; 922 923 goto dropit; 924 } 925 926 if (si->kflags & DN_ACTIVE) { 927 m = *m0 = NULL; /* consumed */ 928 goto done; /* already active, nothing to do */ 929 } 930 931 /* compute the initial allowance */ 932 if (si->idle_time < dn_cfg.curr_time) { 933 /* Do this only on the first packet on an idle pipe */ 934 struct dn_link *p = &fs->sched->link; 935 936 si->sched_time = dn_cfg.curr_time; 937 si->credit = dn_cfg.io_fast ? p->bandwidth : 0; 938 if (p->burst) { 939 uint64_t burst = (dn_cfg.curr_time - si->idle_time) * p->bandwidth; 940 if (burst > p->burst) 941 burst = p->burst; 942 si->credit += burst; 943 } 944 } 945 /* pass through scheduler and delay line */ 946 m = serve_sched(NULL, si, dn_cfg.curr_time); 947 948 /* optimization -- pass it back to ipfw for immediate send */ 949 /* XXX Don't call dummynet_send() if scheduler return the packet 950 * just enqueued. This avoid a lock order reversal. 951 * 952 */ 953 if (/*dn_cfg.io_fast &&*/ m == *m0 && (dir & PROTO_LAYER2) == 0 ) { 954 /* fast io, rename the tag * to carry reinject info. */ 955 struct m_tag *tag = m_tag_first(m); 956 957 tag->m_tag_cookie = MTAG_IPFW_RULE; 958 tag->m_tag_id = 0; 959 io_pkt_fast++; 960 if (m->m_nextpkt != NULL) { 961 printf("dummynet: fast io: pkt chain detected!\n"); 962 m->m_nextpkt = NULL; 963 } 964 m = NULL; 965 } else { 966 *m0 = NULL; 967 } 968 done: 969 DN_BH_WUNLOCK(); 970 if (m) 971 dummynet_send(m); 972 return 0; 973 974 dropit: 975 io_pkt_drop++; 976 DN_BH_WUNLOCK(); 977 if (m) 978 FREE_PKT(m); 979 *m0 = NULL; 980 return (fs && (fs->fs.flags & DN_NOERROR)) ? 0 : ENOBUFS; 981 } 982