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