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