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 * Packets processed by dummynet have an mbuf tag associated with 241 * them that carries their dummynet state. 242 * Outside dummynet, only the 'rule' field is relevant, and it must 243 * be at the beginning of the structure. 244 */ 245 struct dn_pkt_tag { 246 struct ipfw_rule_ref rule; /* matching rule */ 247 248 /* second part, dummynet specific */ 249 int dn_dir; /* action when packet comes out.*/ 250 /* see ip_fw_private.h */ 251 uint64_t output_time; /* when the pkt is due for delivery*/ 252 struct ifnet *ifp; /* interface, for ip_output */ 253 struct _ip6dn_args ip6opt; /* XXX ipv6 options */ 254 }; 255 256 /* 257 * Return the mbuf tag holding the dummynet state (it should 258 * be the first one on the list). 259 */ 260 static struct dn_pkt_tag * 261 dn_tag_get(struct mbuf *m) 262 { 263 struct m_tag *mtag = m_tag_first(m); 264 #ifdef NEW_AQM 265 /* XXX: to skip ts m_tag. For Debugging only*/ 266 if (mtag != NULL && mtag->m_tag_id == DN_AQM_MTAG_TS) { 267 m_tag_delete(m,mtag); 268 mtag = m_tag_first(m); 269 D("skip TS tag"); 270 } 271 #endif 272 KASSERT(mtag != NULL && 273 mtag->m_tag_cookie == MTAG_ABI_COMPAT && 274 mtag->m_tag_id == PACKET_TAG_DUMMYNET, 275 ("packet on dummynet queue w/o dummynet tag!")); 276 return (struct dn_pkt_tag *)(mtag+1); 277 } 278 279 #ifndef NEW_AQM 280 static inline void 281 mq_append(struct mq *q, struct mbuf *m) 282 { 283 #ifdef USERSPACE 284 // buffers from netmap need to be copied 285 // XXX note that the routine is not expected to fail 286 ND("append %p to %p", m, q); 287 if (m->m_flags & M_STACK) { 288 struct mbuf *m_new; 289 void *p; 290 int l, ofs; 291 292 ofs = m->m_data - m->__m_extbuf; 293 // XXX allocate 294 MGETHDR(m_new, M_NOWAIT, MT_DATA); 295 ND("*** WARNING, volatile buf %p ext %p %d dofs %d m_new %p", 296 m, m->__m_extbuf, m->__m_extlen, ofs, m_new); 297 p = m_new->__m_extbuf; /* new pointer */ 298 l = m_new->__m_extlen; /* new len */ 299 if (l <= m->__m_extlen) { 300 panic("extlen too large"); 301 } 302 303 *m_new = *m; // copy 304 m_new->m_flags &= ~M_STACK; 305 m_new->__m_extbuf = p; // point to new buffer 306 _pkt_copy(m->__m_extbuf, p, m->__m_extlen); 307 m_new->m_data = p + ofs; 308 m = m_new; 309 } 310 #endif /* USERSPACE */ 311 if (q->head == NULL) 312 q->head = m; 313 else 314 q->tail->m_nextpkt = m; 315 q->count++; 316 q->tail = m; 317 m->m_nextpkt = NULL; 318 } 319 #endif 320 321 /* 322 * Dispose a list of packet. Use a functions so if we need to do 323 * more work, this is a central point to do it. 324 */ 325 void dn_free_pkts(struct mbuf *mnext) 326 { 327 struct mbuf *m; 328 329 while ((m = mnext) != NULL) { 330 mnext = m->m_nextpkt; 331 FREE_PKT(m); 332 } 333 } 334 335 static int 336 red_drops (struct dn_queue *q, int len) 337 { 338 /* 339 * RED algorithm 340 * 341 * RED calculates the average queue size (avg) using a low-pass filter 342 * with an exponential weighted (w_q) moving average: 343 * avg <- (1-w_q) * avg + w_q * q_size 344 * where q_size is the queue length (measured in bytes or * packets). 345 * 346 * If q_size == 0, we compute the idle time for the link, and set 347 * avg = (1 - w_q)^(idle/s) 348 * where s is the time needed for transmitting a medium-sized packet. 349 * 350 * Now, if avg < min_th the packet is enqueued. 351 * If avg > max_th the packet is dropped. Otherwise, the packet is 352 * dropped with probability P function of avg. 353 */ 354 355 struct dn_fsk *fs = q->fs; 356 int64_t p_b = 0; 357 358 /* Queue in bytes or packets? */ 359 uint32_t q_size = (fs->fs.flags & DN_QSIZE_BYTES) ? 360 q->ni.len_bytes : q->ni.length; 361 362 /* Average queue size estimation. */ 363 if (q_size != 0) { 364 /* Queue is not empty, avg <- avg + (q_size - avg) * w_q */ 365 int diff = SCALE(q_size) - q->avg; 366 int64_t v = SCALE_MUL((int64_t)diff, (int64_t)fs->w_q); 367 368 q->avg += (int)v; 369 } else { 370 /* 371 * Queue is empty, find for how long the queue has been 372 * empty and use a lookup table for computing 373 * (1 - * w_q)^(idle_time/s) where s is the time to send a 374 * (small) packet. 375 * XXX check wraps... 376 */ 377 if (q->avg) { 378 u_int t = div64((dn_cfg.curr_time - q->q_time), fs->lookup_step); 379 380 q->avg = (t < fs->lookup_depth) ? 381 SCALE_MUL(q->avg, fs->w_q_lookup[t]) : 0; 382 } 383 } 384 385 /* Should i drop? */ 386 if (q->avg < fs->min_th) { 387 q->count = -1; 388 return (0); /* accept packet */ 389 } 390 if (q->avg >= fs->max_th) { /* average queue >= max threshold */ 391 if (fs->fs.flags & DN_IS_ECN) 392 return (1); 393 if (fs->fs.flags & DN_IS_GENTLE_RED) { 394 /* 395 * According to Gentle-RED, if avg is greater than 396 * max_th the packet is dropped with a probability 397 * p_b = c_3 * avg - c_4 398 * where c_3 = (1 - max_p) / max_th 399 * c_4 = 1 - 2 * max_p 400 */ 401 p_b = SCALE_MUL((int64_t)fs->c_3, (int64_t)q->avg) - 402 fs->c_4; 403 } else { 404 q->count = -1; 405 return (1); 406 } 407 } else if (q->avg > fs->min_th) { 408 if (fs->fs.flags & DN_IS_ECN) 409 return (1); 410 /* 411 * We compute p_b using the linear dropping function 412 * p_b = c_1 * avg - c_2 413 * where c_1 = max_p / (max_th - min_th) 414 * c_2 = max_p * min_th / (max_th - min_th) 415 */ 416 p_b = SCALE_MUL((int64_t)fs->c_1, (int64_t)q->avg) - fs->c_2; 417 } 418 419 if (fs->fs.flags & DN_QSIZE_BYTES) 420 p_b = div64((p_b * len) , fs->max_pkt_size); 421 if (++q->count == 0) 422 q->random = random() & 0xffff; 423 else { 424 /* 425 * q->count counts packets arrived since last drop, so a greater 426 * value of q->count means a greater packet drop probability. 427 */ 428 if (SCALE_MUL(p_b, SCALE((int64_t)q->count)) > q->random) { 429 q->count = 0; 430 /* After a drop we calculate a new random value. */ 431 q->random = random() & 0xffff; 432 return (1); /* drop */ 433 } 434 } 435 /* End of RED algorithm. */ 436 437 return (0); /* accept */ 438 439 } 440 441 /* 442 * ECN/ECT Processing (partially adopted from altq) 443 */ 444 #ifndef NEW_AQM 445 static 446 #endif 447 int 448 ecn_mark(struct mbuf* m) 449 { 450 struct ip *ip; 451 ip = mtod(m, struct ip *); 452 453 switch (ip->ip_v) { 454 case IPVERSION: 455 { 456 uint16_t old; 457 458 if ((ip->ip_tos & IPTOS_ECN_MASK) == IPTOS_ECN_NOTECT) 459 return (0); /* not-ECT */ 460 if ((ip->ip_tos & IPTOS_ECN_MASK) == IPTOS_ECN_CE) 461 return (1); /* already marked */ 462 463 /* 464 * ecn-capable but not marked, 465 * mark CE and update checksum 466 */ 467 old = *(uint16_t *)ip; 468 ip->ip_tos |= IPTOS_ECN_CE; 469 ip->ip_sum = cksum_adjust(ip->ip_sum, old, *(uint16_t *)ip); 470 return (1); 471 } 472 #ifdef INET6 473 case (IPV6_VERSION >> 4): 474 { 475 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); 476 u_int32_t flowlabel; 477 478 flowlabel = ntohl(ip6->ip6_flow); 479 if ((flowlabel >> 28) != 6) 480 return (0); /* version mismatch! */ 481 if ((flowlabel & (IPTOS_ECN_MASK << 20)) == 482 (IPTOS_ECN_NOTECT << 20)) 483 return (0); /* not-ECT */ 484 if ((flowlabel & (IPTOS_ECN_MASK << 20)) == 485 (IPTOS_ECN_CE << 20)) 486 return (1); /* already marked */ 487 /* 488 * ecn-capable but not marked, mark CE 489 */ 490 flowlabel |= (IPTOS_ECN_CE << 20); 491 ip6->ip6_flow = htonl(flowlabel); 492 return (1); 493 } 494 #endif 495 } 496 return (0); 497 } 498 499 /* 500 * Enqueue a packet in q, subject to space and queue management policy 501 * (whose parameters are in q->fs). 502 * Update stats for the queue and the scheduler. 503 * Return 0 on success, 1 on drop. The packet is consumed anyways. 504 */ 505 int 506 dn_enqueue(struct dn_queue *q, struct mbuf* m, int drop) 507 { 508 struct dn_fs *f; 509 struct dn_flow *ni; /* stats for scheduler instance */ 510 uint64_t len; 511 512 if (q->fs == NULL || q->_si == NULL) { 513 printf("%s fs %p si %p, dropping\n", 514 __FUNCTION__, q->fs, q->_si); 515 FREE_PKT(m); 516 return 1; 517 } 518 f = &(q->fs->fs); 519 ni = &q->_si->ni; 520 len = m->m_pkthdr.len; 521 /* Update statistics, then check reasons to drop pkt. */ 522 q->ni.tot_bytes += len; 523 q->ni.tot_pkts++; 524 ni->tot_bytes += len; 525 ni->tot_pkts++; 526 if (drop) 527 goto drop; 528 if (f->plr && random() < f->plr) 529 goto drop; 530 #ifdef NEW_AQM 531 /* Call AQM enqueue function */ 532 if (q->fs->aqmfp) 533 return q->fs->aqmfp->enqueue(q ,m); 534 #endif 535 if (f->flags & DN_IS_RED && red_drops(q, m->m_pkthdr.len)) { 536 if (!(f->flags & DN_IS_ECN) || !ecn_mark(m)) 537 goto drop; 538 } 539 if (f->flags & DN_QSIZE_BYTES) { 540 if (q->ni.len_bytes > f->qsize) 541 goto drop; 542 } else if (q->ni.length >= f->qsize) { 543 goto drop; 544 } 545 mq_append(&q->mq, m); 546 q->ni.length++; 547 q->ni.len_bytes += len; 548 ni->length++; 549 ni->len_bytes += len; 550 return (0); 551 552 drop: 553 io_pkt_drop++; 554 q->ni.drops++; 555 ni->drops++; 556 FREE_PKT(m); 557 return (1); 558 } 559 560 /* 561 * Fetch packets from the delay line which are due now. If there are 562 * leftover packets, reinsert the delay line in the heap. 563 * Runs under scheduler lock. 564 */ 565 static void 566 transmit_event(struct mq *q, struct delay_line *dline, uint64_t now) 567 { 568 struct mbuf *m; 569 struct dn_pkt_tag *pkt = NULL; 570 571 dline->oid.subtype = 0; /* not in heap */ 572 while ((m = dline->mq.head) != NULL) { 573 pkt = dn_tag_get(m); 574 if (!DN_KEY_LEQ(pkt->output_time, now)) 575 break; 576 dline->mq.head = m->m_nextpkt; 577 dline->mq.count--; 578 mq_append(q, m); 579 } 580 if (m != NULL) { 581 dline->oid.subtype = 1; /* in heap */ 582 heap_insert(&dn_cfg.evheap, pkt->output_time, dline); 583 } 584 } 585 586 /* 587 * Convert the additional MAC overheads/delays into an equivalent 588 * number of bits for the given data rate. The samples are 589 * in milliseconds so we need to divide by 1000. 590 */ 591 static uint64_t 592 extra_bits(struct mbuf *m, struct dn_schk *s) 593 { 594 int index; 595 uint64_t bits; 596 struct dn_profile *pf = s->profile; 597 598 if (!pf || pf->samples_no == 0) 599 return 0; 600 index = random() % pf->samples_no; 601 bits = div64((uint64_t)pf->samples[index] * s->link.bandwidth, 1000); 602 if (index >= pf->loss_level) { 603 struct dn_pkt_tag *dt = dn_tag_get(m); 604 if (dt) 605 dt->dn_dir = DIR_DROP; 606 } 607 return bits; 608 } 609 610 /* 611 * Send traffic from a scheduler instance due by 'now'. 612 * Return a pointer to the head of the queue. 613 */ 614 static struct mbuf * 615 serve_sched(struct mq *q, struct dn_sch_inst *si, uint64_t now) 616 { 617 struct mq def_q; 618 struct dn_schk *s = si->sched; 619 struct mbuf *m = NULL; 620 int delay_line_idle = (si->dline.mq.head == NULL); 621 int done, bw; 622 623 if (q == NULL) { 624 q = &def_q; 625 q->head = NULL; 626 } 627 628 bw = s->link.bandwidth; 629 si->kflags &= ~DN_ACTIVE; 630 631 if (bw > 0) 632 si->credit += (now - si->sched_time) * bw; 633 else 634 si->credit = 0; 635 si->sched_time = now; 636 done = 0; 637 while (si->credit >= 0 && (m = s->fp->dequeue(si)) != NULL) { 638 uint64_t len_scaled; 639 640 done++; 641 len_scaled = (bw == 0) ? 0 : hz * 642 (m->m_pkthdr.len * 8 + extra_bits(m, s)); 643 si->credit -= len_scaled; 644 /* Move packet in the delay line */ 645 dn_tag_get(m)->output_time = dn_cfg.curr_time + s->link.delay ; 646 mq_append(&si->dline.mq, m); 647 } 648 649 /* 650 * If credit >= 0 the instance is idle, mark time. 651 * Otherwise put back in the heap, and adjust the output 652 * time of the last inserted packet, m, which was too early. 653 */ 654 if (si->credit >= 0) { 655 si->idle_time = now; 656 } else { 657 uint64_t t; 658 KASSERT (bw > 0, ("bw=0 and credit<0 ?")); 659 t = div64(bw - 1 - si->credit, bw); 660 if (m) 661 dn_tag_get(m)->output_time += t; 662 si->kflags |= DN_ACTIVE; 663 heap_insert(&dn_cfg.evheap, now + t, si); 664 } 665 if (delay_line_idle && done) 666 transmit_event(q, &si->dline, now); 667 return q->head; 668 } 669 670 /* 671 * The timer handler for dummynet. Time is computed in ticks, but 672 * but the code is tolerant to the actual rate at which this is called. 673 * Once complete, the function reschedules itself for the next tick. 674 */ 675 void 676 dummynet_task(void *context, int pending) 677 { 678 struct timeval t; 679 struct mq q = { NULL, NULL }; /* queue to accumulate results */ 680 681 CURVNET_SET((struct vnet *)context); 682 683 DN_BH_WLOCK(); 684 685 /* Update number of lost(coalesced) ticks. */ 686 tick_lost += pending - 1; 687 688 getmicrouptime(&t); 689 /* Last tick duration (usec). */ 690 tick_last = (t.tv_sec - dn_cfg.prev_t.tv_sec) * 1000000 + 691 (t.tv_usec - dn_cfg.prev_t.tv_usec); 692 /* Last tick vs standard tick difference (usec). */ 693 tick_delta = (tick_last * hz - 1000000) / hz; 694 /* Accumulated tick difference (usec). */ 695 tick_delta_sum += tick_delta; 696 697 dn_cfg.prev_t = t; 698 699 /* 700 * Adjust curr_time if the accumulated tick difference is 701 * greater than the 'standard' tick. Since curr_time should 702 * be monotonically increasing, we do positive adjustments 703 * as required, and throttle curr_time in case of negative 704 * adjustment. 705 */ 706 dn_cfg.curr_time++; 707 if (tick_delta_sum - tick >= 0) { 708 int diff = tick_delta_sum / tick; 709 710 dn_cfg.curr_time += diff; 711 tick_diff += diff; 712 tick_delta_sum %= tick; 713 tick_adjustment++; 714 } else if (tick_delta_sum + tick <= 0) { 715 dn_cfg.curr_time--; 716 tick_diff--; 717 tick_delta_sum += tick; 718 tick_adjustment++; 719 } 720 721 /* serve pending events, accumulate in q */ 722 for (;;) { 723 struct dn_id *p; /* generic parameter to handler */ 724 725 if (dn_cfg.evheap.elements == 0 || 726 DN_KEY_LT(dn_cfg.curr_time, HEAP_TOP(&dn_cfg.evheap)->key)) 727 break; 728 p = HEAP_TOP(&dn_cfg.evheap)->object; 729 heap_extract(&dn_cfg.evheap, NULL); 730 731 if (p->type == DN_SCH_I) { 732 serve_sched(&q, (struct dn_sch_inst *)p, dn_cfg.curr_time); 733 } else { /* extracted a delay line */ 734 transmit_event(&q, (struct delay_line *)p, dn_cfg.curr_time); 735 } 736 } 737 if (dn_cfg.expire && ++dn_cfg.expire_cycle >= dn_cfg.expire) { 738 dn_cfg.expire_cycle = 0; 739 dn_drain_scheduler(); 740 dn_drain_queue(); 741 } 742 743 dn_reschedule(); 744 DN_BH_WUNLOCK(); 745 if (q.head != NULL) 746 dummynet_send(q.head); 747 CURVNET_RESTORE(); 748 } 749 750 /* 751 * forward a chain of packets to the proper destination. 752 * This runs outside the dummynet lock. 753 */ 754 static void 755 dummynet_send(struct mbuf *m) 756 { 757 struct mbuf *n; 758 759 for (; m != NULL; m = n) { 760 struct ifnet *ifp = NULL; /* gcc 3.4.6 complains */ 761 struct m_tag *tag; 762 int dst; 763 764 n = m->m_nextpkt; 765 m->m_nextpkt = NULL; 766 tag = m_tag_first(m); 767 if (tag == NULL) { /* should not happen */ 768 dst = DIR_DROP; 769 } else { 770 struct dn_pkt_tag *pkt = dn_tag_get(m); 771 /* extract the dummynet info, rename the tag 772 * to carry reinject info. 773 */ 774 if (pkt->dn_dir == (DIR_OUT | PROTO_LAYER2) && 775 pkt->ifp == NULL) { 776 dst = DIR_DROP; 777 } else { 778 dst = pkt->dn_dir; 779 ifp = pkt->ifp; 780 tag->m_tag_cookie = MTAG_IPFW_RULE; 781 tag->m_tag_id = 0; 782 } 783 } 784 785 switch (dst) { 786 case DIR_OUT: 787 ip_output(m, NULL, NULL, IP_FORWARDING, NULL, NULL); 788 break ; 789 790 case DIR_IN : 791 netisr_dispatch(NETISR_IP, m); 792 break; 793 794 #ifdef INET6 795 case DIR_IN | PROTO_IPV6: 796 netisr_dispatch(NETISR_IPV6, m); 797 break; 798 799 case DIR_OUT | PROTO_IPV6: 800 ip6_output(m, NULL, NULL, IPV6_FORWARDING, NULL, NULL, NULL); 801 break; 802 #endif 803 804 case DIR_FWD | PROTO_IFB: /* DN_TO_IFB_FWD: */ 805 if (bridge_dn_p != NULL) 806 ((*bridge_dn_p)(m, ifp)); 807 else 808 printf("dummynet: if_bridge not loaded\n"); 809 810 break; 811 812 case DIR_IN | PROTO_LAYER2: /* DN_TO_ETH_DEMUX: */ 813 /* 814 * The Ethernet code assumes the Ethernet header is 815 * contiguous in the first mbuf header. 816 * Insure this is true. 817 */ 818 if (m->m_len < ETHER_HDR_LEN && 819 (m = m_pullup(m, ETHER_HDR_LEN)) == NULL) { 820 printf("dummynet/ether: pullup failed, " 821 "dropping packet\n"); 822 break; 823 } 824 ether_demux(m->m_pkthdr.rcvif, m); 825 break; 826 827 case DIR_OUT | PROTO_LAYER2: /* N_TO_ETH_OUT: */ 828 ether_output_frame(ifp, m); 829 break; 830 831 case DIR_DROP: 832 /* drop the packet after some time */ 833 FREE_PKT(m); 834 break; 835 836 default: 837 printf("dummynet: bad switch %d!\n", dst); 838 FREE_PKT(m); 839 break; 840 } 841 } 842 } 843 844 static inline int 845 tag_mbuf(struct mbuf *m, int dir, struct ip_fw_args *fwa) 846 { 847 struct dn_pkt_tag *dt; 848 struct m_tag *mtag; 849 850 mtag = m_tag_get(PACKET_TAG_DUMMYNET, 851 sizeof(*dt), M_NOWAIT | M_ZERO); 852 if (mtag == NULL) 853 return 1; /* Cannot allocate packet header. */ 854 m_tag_prepend(m, mtag); /* Attach to mbuf chain. */ 855 dt = (struct dn_pkt_tag *)(mtag + 1); 856 dt->rule = fwa->rule; 857 dt->rule.info &= IPFW_ONEPASS; /* only keep this info */ 858 dt->dn_dir = dir; 859 dt->ifp = fwa->oif; 860 /* dt->output tame is updated as we move through */ 861 dt->output_time = dn_cfg.curr_time; 862 return 0; 863 } 864 865 866 /* 867 * dummynet hook for packets. 868 * We use the argument to locate the flowset fs and the sched_set sch 869 * associated to it. The we apply flow_mask and sched_mask to 870 * determine the queue and scheduler instances. 871 * 872 * dir where shall we send the packet after dummynet. 873 * *m0 the mbuf with the packet 874 * ifp the 'ifp' parameter from the caller. 875 * NULL in ip_input, destination interface in ip_output, 876 */ 877 int 878 dummynet_io(struct mbuf **m0, int dir, struct ip_fw_args *fwa) 879 { 880 struct mbuf *m = *m0; 881 struct dn_fsk *fs = NULL; 882 struct dn_sch_inst *si; 883 struct dn_queue *q = NULL; /* default */ 884 885 int fs_id = (fwa->rule.info & IPFW_INFO_MASK) + 886 ((fwa->rule.info & IPFW_IS_PIPE) ? 2*DN_MAX_ID : 0); 887 DN_BH_WLOCK(); 888 io_pkt++; 889 /* we could actually tag outside the lock, but who cares... */ 890 if (tag_mbuf(m, dir, fwa)) 891 goto dropit; 892 if (dn_cfg.busy) { 893 /* if the upper half is busy doing something expensive, 894 * lets queue the packet and move forward 895 */ 896 mq_append(&dn_cfg.pending, m); 897 m = *m0 = NULL; /* consumed */ 898 goto done; /* already active, nothing to do */ 899 } 900 /* XXX locate_flowset could be optimised with a direct ref. */ 901 fs = dn_ht_find(dn_cfg.fshash, fs_id, 0, NULL); 902 if (fs == NULL) 903 goto dropit; /* This queue/pipe does not exist! */ 904 if (fs->sched == NULL) /* should not happen */ 905 goto dropit; 906 /* find scheduler instance, possibly applying sched_mask */ 907 si = ipdn_si_find(fs->sched, &(fwa->f_id)); 908 if (si == NULL) 909 goto dropit; 910 /* 911 * If the scheduler supports multiple queues, find the right one 912 * (otherwise it will be ignored by enqueue). 913 */ 914 if (fs->sched->fp->flags & DN_MULTIQUEUE) { 915 q = ipdn_q_find(fs, si, &(fwa->f_id)); 916 if (q == NULL) 917 goto dropit; 918 } 919 if (fs->sched->fp->enqueue(si, q, m)) { 920 /* packet was dropped by enqueue() */ 921 m = *m0 = NULL; 922 923 /* dn_enqueue already increases io_pkt_drop */ 924 io_pkt_drop--; 925 926 goto dropit; 927 } 928 929 if (si->kflags & DN_ACTIVE) { 930 m = *m0 = NULL; /* consumed */ 931 goto done; /* already active, nothing to do */ 932 } 933 934 /* compute the initial allowance */ 935 if (si->idle_time < dn_cfg.curr_time) { 936 /* Do this only on the first packet on an idle pipe */ 937 struct dn_link *p = &fs->sched->link; 938 939 si->sched_time = dn_cfg.curr_time; 940 si->credit = dn_cfg.io_fast ? p->bandwidth : 0; 941 if (p->burst) { 942 uint64_t burst = (dn_cfg.curr_time - si->idle_time) * p->bandwidth; 943 if (burst > p->burst) 944 burst = p->burst; 945 si->credit += burst; 946 } 947 } 948 /* pass through scheduler and delay line */ 949 m = serve_sched(NULL, si, dn_cfg.curr_time); 950 951 /* optimization -- pass it back to ipfw for immediate send */ 952 /* XXX Don't call dummynet_send() if scheduler return the packet 953 * just enqueued. This avoid a lock order reversal. 954 * 955 */ 956 if (/*dn_cfg.io_fast &&*/ m == *m0 && (dir & PROTO_LAYER2) == 0 ) { 957 /* fast io, rename the tag * to carry reinject info. */ 958 struct m_tag *tag = m_tag_first(m); 959 960 tag->m_tag_cookie = MTAG_IPFW_RULE; 961 tag->m_tag_id = 0; 962 io_pkt_fast++; 963 if (m->m_nextpkt != NULL) { 964 printf("dummynet: fast io: pkt chain detected!\n"); 965 m->m_nextpkt = NULL; 966 } 967 m = NULL; 968 } else { 969 *m0 = NULL; 970 } 971 done: 972 DN_BH_WUNLOCK(); 973 if (m) 974 dummynet_send(m); 975 return 0; 976 977 dropit: 978 io_pkt_drop++; 979 DN_BH_WUNLOCK(); 980 if (m) 981 FREE_PKT(m); 982 *m0 = NULL; 983 return (fs && (fs->fs.flags & DN_NOERROR)) ? 0 : ENOBUFS; 984 } 985