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
sysctl_hash_size(SYSCTL_HANDLER_ARGS)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
sysctl_limits(SYSCTL_HANDLER_ARGS)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 *
dn_tag_get(struct mbuf * m)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
mq_append(struct mq * q,struct mbuf * m)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 */
dn_free_pkts(struct mbuf * mnext)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
red_drops(struct dn_queue * q,int len)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
ecn_mark(struct mbuf * m)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
dn_enqueue(struct dn_queue * q,struct mbuf * m,int drop)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
transmit_event(struct mq * q,struct delay_line * dline,uint64_t now)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
extra_bits(struct mbuf * m,struct dn_schk * s)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 *
serve_sched(struct mq * q,struct dn_sch_inst * si,uint64_t now)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
dummynet_task(void * context,int pending)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
dummynet_send(struct mbuf * m)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: /* DN_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
tag_mbuf(struct mbuf * m,int dir,struct ip_fw_args * fwa)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
dummynet_io(struct mbuf ** m0,int dir,struct ip_fw_args * fwa)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