1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
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 #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/sdt.h>
47 #include <sys/socket.h>
48 #include <sys/time.h>
49 #include <sys/sysctl.h>
50
51 #include <net/if.h> /* IFNAMSIZ, struct ifaddr, ifq head, lock.h mutex.h */
52 #include <net/if_var.h> /* NET_EPOCH_... */
53 #include <net/if_private.h>
54 #include <net/netisr.h>
55 #include <net/vnet.h>
56
57 #include <netinet/in.h>
58 #include <netinet/ip.h> /* ip_len, ip_off */
59 #include <netinet/ip_var.h> /* ip_output(), IP_FORWARDING */
60 #include <netinet/ip_fw.h>
61 #include <netinet/ip_dummynet.h>
62 #include <netinet/if_ether.h> /* various ether_* routines */
63 #include <netinet/ip6.h> /* for ip6_input, ip6_output prototypes */
64 #include <netinet6/ip6_var.h>
65
66 #include <netpfil/ipfw/ip_fw_private.h>
67 #include <netpfil/ipfw/dn_heap.h>
68 #include <netpfil/ipfw/ip_dn_private.h>
69 #ifdef NEW_AQM
70 #include <netpfil/ipfw/dn_aqm.h>
71 #endif
72 #include <netpfil/ipfw/dn_sched.h>
73
74 SDT_PROVIDER_DEFINE(dummynet);
75 SDT_PROBE_DEFINE2(dummynet, , , drop, "struct mbuf *", "struct dn_queue *");
76
77 /*
78 * We keep a private variable for the simulation time, but we could
79 * probably use an existing one ("softticks" in sys/kern/kern_timeout.c)
80 * instead of V_dn_cfg.curr_time
81 */
82 VNET_DEFINE(struct dn_parms, dn_cfg);
83 #define V_dn_cfg VNET(dn_cfg)
84
85 /*
86 * We use a heap to store entities for which we have pending timer events.
87 * The heap is checked at every tick and all entities with expired events
88 * are extracted.
89 */
90
91 MALLOC_DEFINE(M_DUMMYNET, "dummynet", "dummynet heap");
92
93 extern void (*bridge_dn_p)(struct mbuf *, struct ifnet *);
94
95 #ifdef SYSCTL_NODE
96
97 /*
98 * Because of the way the SYSBEGIN/SYSEND macros work on other
99 * platforms, there should not be functions between them.
100 * So keep the handlers outside the block.
101 */
102 static int
sysctl_hash_size(SYSCTL_HANDLER_ARGS)103 sysctl_hash_size(SYSCTL_HANDLER_ARGS)
104 {
105 int error, value;
106
107 value = V_dn_cfg.hash_size;
108 error = sysctl_handle_int(oidp, &value, 0, req);
109 if (error != 0 || req->newptr == NULL)
110 return (error);
111 if (value < 16 || value > 65536)
112 return (EINVAL);
113 V_dn_cfg.hash_size = value;
114 return (0);
115 }
116
117 static int
sysctl_limits(SYSCTL_HANDLER_ARGS)118 sysctl_limits(SYSCTL_HANDLER_ARGS)
119 {
120 int error;
121 long value;
122
123 if (arg2 != 0)
124 value = V_dn_cfg.slot_limit;
125 else
126 value = V_dn_cfg.byte_limit;
127 error = sysctl_handle_long(oidp, &value, 0, req);
128
129 if (error != 0 || req->newptr == NULL)
130 return (error);
131 if (arg2 != 0) {
132 if (value < 1)
133 return (EINVAL);
134 V_dn_cfg.slot_limit = value;
135 } else {
136 if (value < 1500)
137 return (EINVAL);
138 V_dn_cfg.byte_limit = value;
139 }
140 return (0);
141 }
142
143 SYSBEGIN(f4)
144
145 SYSCTL_DECL(_net_inet);
146 SYSCTL_DECL(_net_inet_ip);
147 #ifdef NEW_AQM
148 SYSCTL_NODE(_net_inet_ip, OID_AUTO, dummynet, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
149 "Dummynet");
150 #else
151 static SYSCTL_NODE(_net_inet_ip, OID_AUTO, dummynet,
152 CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
153 "Dummynet");
154 #endif
155
156 /* wrapper to pass V_dn_cfg fields to SYSCTL_* */
157 #define DC(x) (&(VNET_NAME(dn_cfg).x))
158
159 /* parameters */
160
161 SYSCTL_PROC(_net_inet_ip_dummynet, OID_AUTO, hash_size,
162 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
163 0, 0, sysctl_hash_size, "I",
164 "Default hash table size");
165
166 SYSCTL_PROC(_net_inet_ip_dummynet, OID_AUTO, pipe_slot_limit,
167 CTLTYPE_LONG | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
168 0, 1, sysctl_limits, "L",
169 "Upper limit in slots for pipe queue.");
170 SYSCTL_PROC(_net_inet_ip_dummynet, OID_AUTO, pipe_byte_limit,
171 CTLTYPE_LONG | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
172 0, 0, sysctl_limits, "L",
173 "Upper limit in bytes for pipe queue.");
174 SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, io_fast,
175 CTLFLAG_RW | CTLFLAG_VNET, DC(io_fast), 0, "Enable fast dummynet io.");
176 SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, debug,
177 CTLFLAG_RW | CTLFLAG_VNET, DC(debug), 0, "Dummynet debug level");
178
179 /* RED parameters */
180 SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, red_lookup_depth,
181 CTLFLAG_RD | CTLFLAG_VNET, DC(red_lookup_depth), 0, "Depth of RED lookup table");
182 SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, red_avg_pkt_size,
183 CTLFLAG_RD | CTLFLAG_VNET, DC(red_avg_pkt_size), 0, "RED Medium packet size");
184 SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, red_max_pkt_size,
185 CTLFLAG_RD | CTLFLAG_VNET, DC(red_max_pkt_size), 0, "RED Max packet size");
186
187 /* time adjustment */
188 SYSCTL_LONG(_net_inet_ip_dummynet, OID_AUTO, tick_delta,
189 CTLFLAG_RD | CTLFLAG_VNET, DC(tick_delta), 0, "Last vs standard tick difference (usec).");
190 SYSCTL_LONG(_net_inet_ip_dummynet, OID_AUTO, tick_delta_sum,
191 CTLFLAG_RD | CTLFLAG_VNET, DC(tick_delta_sum), 0, "Accumulated tick difference (usec).");
192 SYSCTL_LONG(_net_inet_ip_dummynet, OID_AUTO, tick_adjustment,
193 CTLFLAG_RD | CTLFLAG_VNET, DC(tick_adjustment), 0, "Tick adjustments done.");
194 SYSCTL_LONG(_net_inet_ip_dummynet, OID_AUTO, tick_diff,
195 CTLFLAG_RD | CTLFLAG_VNET, DC(tick_diff), 0,
196 "Adjusted vs non-adjusted curr_time difference (ticks).");
197 SYSCTL_LONG(_net_inet_ip_dummynet, OID_AUTO, tick_lost,
198 CTLFLAG_RD | CTLFLAG_VNET, DC(tick_lost), 0,
199 "Number of ticks coalesced by dummynet taskqueue.");
200
201 /* Drain parameters */
202 SYSCTL_UINT(_net_inet_ip_dummynet, OID_AUTO, expire,
203 CTLFLAG_RW | CTLFLAG_VNET, DC(expire), 0, "Expire empty queues/pipes");
204 SYSCTL_UINT(_net_inet_ip_dummynet, OID_AUTO, expire_cycle,
205 CTLFLAG_RD | CTLFLAG_VNET, DC(expire_cycle), 0, "Expire cycle for queues/pipes");
206
207 /* statistics */
208 SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, schk_count,
209 CTLFLAG_RD | CTLFLAG_VNET, DC(schk_count), 0, "Number of schedulers");
210 SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, si_count,
211 CTLFLAG_RD | CTLFLAG_VNET, DC(si_count), 0, "Number of scheduler instances");
212 SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, fsk_count,
213 CTLFLAG_RD | CTLFLAG_VNET, DC(fsk_count), 0, "Number of flowsets");
214 SYSCTL_INT(_net_inet_ip_dummynet, OID_AUTO, queue_count,
215 CTLFLAG_RD | CTLFLAG_VNET, DC(queue_count), 0, "Number of queues");
216 SYSCTL_ULONG(_net_inet_ip_dummynet, OID_AUTO, io_pkt,
217 CTLFLAG_RD | CTLFLAG_VNET, DC(io_pkt), 0,
218 "Number of packets passed to dummynet.");
219 SYSCTL_ULONG(_net_inet_ip_dummynet, OID_AUTO, io_pkt_fast,
220 CTLFLAG_RD | CTLFLAG_VNET, DC(io_pkt_fast), 0,
221 "Number of packets bypassed dummynet scheduler.");
222 SYSCTL_ULONG(_net_inet_ip_dummynet, OID_AUTO, io_pkt_drop,
223 CTLFLAG_RD | CTLFLAG_VNET, DC(io_pkt_drop), 0,
224 "Number of packets dropped by dummynet.");
225 #undef DC
226 SYSEND
227
228 #endif
229
230 static void dummynet_send(struct mbuf *);
231
232 /*
233 * Return the mbuf tag holding the dummynet state (it should
234 * be the first one on the list).
235 */
236 struct dn_pkt_tag *
dn_tag_get(struct mbuf * m)237 dn_tag_get(struct mbuf *m)
238 {
239 struct m_tag *mtag = m_tag_first(m);
240 #ifdef NEW_AQM
241 /* XXX: to skip ts m_tag. For Debugging only*/
242 if (mtag != NULL && mtag->m_tag_id == DN_AQM_MTAG_TS) {
243 m_tag_delete(m,mtag);
244 mtag = m_tag_first(m);
245 D("skip TS tag");
246 }
247 #endif
248 KASSERT(mtag != NULL &&
249 mtag->m_tag_cookie == MTAG_ABI_COMPAT &&
250 mtag->m_tag_id == PACKET_TAG_DUMMYNET,
251 ("packet on dummynet queue w/o dummynet tag!"));
252 return (struct dn_pkt_tag *)(mtag+1);
253 }
254
255 #ifndef NEW_AQM
256 static inline void
mq_append(struct mq * q,struct mbuf * m)257 mq_append(struct mq *q, struct mbuf *m)
258 {
259 #ifdef USERSPACE
260 // buffers from netmap need to be copied
261 // XXX note that the routine is not expected to fail
262 ND("append %p to %p", m, q);
263 if (m->m_flags & M_STACK) {
264 struct mbuf *m_new;
265 void *p;
266 int l, ofs;
267
268 ofs = m->m_data - m->__m_extbuf;
269 // XXX allocate
270 MGETHDR(m_new, M_NOWAIT, MT_DATA);
271 ND("*** WARNING, volatile buf %p ext %p %d dofs %d m_new %p",
272 m, m->__m_extbuf, m->__m_extlen, ofs, m_new);
273 p = m_new->__m_extbuf; /* new pointer */
274 l = m_new->__m_extlen; /* new len */
275 if (l <= m->__m_extlen) {
276 panic("extlen too large");
277 }
278
279 *m_new = *m; // copy
280 m_new->m_flags &= ~M_STACK;
281 m_new->__m_extbuf = p; // point to new buffer
282 _pkt_copy(m->__m_extbuf, p, m->__m_extlen);
283 m_new->m_data = p + ofs;
284 m = m_new;
285 }
286 #endif /* USERSPACE */
287 if (q->head == NULL)
288 q->head = m;
289 else
290 q->tail->m_nextpkt = m;
291 q->count++;
292 q->tail = m;
293 m->m_nextpkt = NULL;
294 }
295 #endif
296
297 /*
298 * Dispose a list of packet. Use a functions so if we need to do
299 * more work, this is a central point to do it.
300 */
dn_free_pkts(struct mbuf * mnext)301 void dn_free_pkts(struct mbuf *mnext)
302 {
303 struct mbuf *m;
304
305 while ((m = mnext) != NULL) {
306 mnext = m->m_nextpkt;
307 FREE_PKT(m);
308 }
309 }
310
311 static int
red_drops(struct dn_queue * q,int len)312 red_drops (struct dn_queue *q, int len)
313 {
314 /*
315 * RED algorithm
316 *
317 * RED calculates the average queue size (avg) using a low-pass filter
318 * with an exponential weighted (w_q) moving average:
319 * avg <- (1-w_q) * avg + w_q * q_size
320 * where q_size is the queue length (measured in bytes or * packets).
321 *
322 * If q_size == 0, we compute the idle time for the link, and set
323 * avg = (1 - w_q)^(idle/s)
324 * where s is the time needed for transmitting a medium-sized packet.
325 *
326 * Now, if avg < min_th the packet is enqueued.
327 * If avg > max_th the packet is dropped. Otherwise, the packet is
328 * dropped with probability P function of avg.
329 */
330
331 struct dn_fsk *fs = q->fs;
332 int64_t p_b = 0;
333
334 /* Queue in bytes or packets? */
335 uint32_t q_size = (fs->fs.flags & DN_QSIZE_BYTES) ?
336 q->ni.len_bytes : q->ni.length;
337
338 /* Average queue size estimation. */
339 if (q_size != 0) {
340 /* Queue is not empty, avg <- avg + (q_size - avg) * w_q */
341 int diff = SCALE(q_size) - q->avg;
342 int64_t v = SCALE_MUL((int64_t)diff, (int64_t)fs->w_q);
343
344 q->avg += (int)v;
345 } else {
346 /*
347 * Queue is empty, find for how long the queue has been
348 * empty and use a lookup table for computing
349 * (1 - * w_q)^(idle_time/s) where s is the time to send a
350 * (small) packet.
351 * XXX check wraps...
352 */
353 if (q->avg) {
354 u_int t = div64((V_dn_cfg.curr_time - q->q_time), fs->lookup_step);
355
356 q->avg = (t < fs->lookup_depth) ?
357 SCALE_MUL(q->avg, fs->w_q_lookup[t]) : 0;
358 }
359 }
360
361 /* Should i drop? */
362 if (q->avg < fs->min_th) {
363 q->count = -1;
364 return (0); /* accept packet */
365 }
366 if (q->avg >= fs->max_th) { /* average queue >= max threshold */
367 if (fs->fs.flags & DN_IS_ECN)
368 return (1);
369 if (fs->fs.flags & DN_IS_GENTLE_RED) {
370 /*
371 * According to Gentle-RED, if avg is greater than
372 * max_th the packet is dropped with a probability
373 * p_b = c_3 * avg - c_4
374 * where c_3 = (1 - max_p) / max_th
375 * c_4 = 1 - 2 * max_p
376 */
377 p_b = SCALE_MUL((int64_t)fs->c_3, (int64_t)q->avg) -
378 fs->c_4;
379 } else {
380 q->count = -1;
381 return (1);
382 }
383 } else if (q->avg > fs->min_th) {
384 if (fs->fs.flags & DN_IS_ECN)
385 return (1);
386 /*
387 * We compute p_b using the linear dropping function
388 * p_b = c_1 * avg - c_2
389 * where c_1 = max_p / (max_th - min_th)
390 * c_2 = max_p * min_th / (max_th - min_th)
391 */
392 p_b = SCALE_MUL((int64_t)fs->c_1, (int64_t)q->avg) - fs->c_2;
393 }
394
395 if (fs->fs.flags & DN_QSIZE_BYTES)
396 p_b = div64((p_b * len) , fs->max_pkt_size);
397 if (++q->count == 0)
398 q->random = random() & 0xffff;
399 else {
400 /*
401 * q->count counts packets arrived since last drop, so a greater
402 * value of q->count means a greater packet drop probability.
403 */
404 if (SCALE_MUL(p_b, SCALE((int64_t)q->count)) > q->random) {
405 q->count = 0;
406 /* After a drop we calculate a new random value. */
407 q->random = random() & 0xffff;
408 return (1); /* drop */
409 }
410 }
411 /* End of RED algorithm. */
412
413 return (0); /* accept */
414
415 }
416
417 /*
418 * ECN/ECT Processing (partially adopted from altq)
419 */
420 #ifndef NEW_AQM
421 static
422 #endif
423 int
ecn_mark(struct mbuf * m)424 ecn_mark(struct mbuf* m)
425 {
426 struct ip *ip;
427 ip = (struct ip *)mtodo(m, dn_tag_get(m)->iphdr_off);
428
429 switch (ip->ip_v) {
430 case IPVERSION:
431 {
432 uint16_t old;
433
434 if ((ip->ip_tos & IPTOS_ECN_MASK) == IPTOS_ECN_NOTECT)
435 return (0); /* not-ECT */
436 if ((ip->ip_tos & IPTOS_ECN_MASK) == IPTOS_ECN_CE)
437 return (1); /* already marked */
438
439 /*
440 * ecn-capable but not marked,
441 * mark CE and update checksum
442 */
443 old = *(uint16_t *)ip;
444 ip->ip_tos |= IPTOS_ECN_CE;
445 ip->ip_sum = cksum_adjust(ip->ip_sum, old, *(uint16_t *)ip);
446 return (1);
447 }
448 #ifdef INET6
449 case (IPV6_VERSION >> 4):
450 {
451 struct ip6_hdr *ip6 = (struct ip6_hdr *)ip;
452 u_int32_t flowlabel;
453
454 flowlabel = ntohl(ip6->ip6_flow);
455 if ((flowlabel >> 28) != 6)
456 return (0); /* version mismatch! */
457 if ((flowlabel & (IPTOS_ECN_MASK << 20)) ==
458 (IPTOS_ECN_NOTECT << 20))
459 return (0); /* not-ECT */
460 if ((flowlabel & (IPTOS_ECN_MASK << 20)) ==
461 (IPTOS_ECN_CE << 20))
462 return (1); /* already marked */
463 /*
464 * ecn-capable but not marked, mark CE
465 */
466 flowlabel |= (IPTOS_ECN_CE << 20);
467 ip6->ip6_flow = htonl(flowlabel);
468 return (1);
469 }
470 #endif
471 }
472 return (0);
473 }
474
475 /*
476 * Enqueue a packet in q, subject to space and queue management policy
477 * (whose parameters are in q->fs).
478 * Update stats for the queue and the scheduler.
479 * Return 0 on success, 1 on drop. The packet is consumed anyways.
480 */
481 int
dn_enqueue(struct dn_queue * q,struct mbuf * m,int drop)482 dn_enqueue(struct dn_queue *q, struct mbuf* m, int drop)
483 {
484 struct dn_fs *f;
485 struct dn_flow *ni; /* stats for scheduler instance */
486 uint64_t len;
487
488 if (q->fs == NULL || q->_si == NULL) {
489 printf("%s fs %p si %p, dropping\n",
490 __FUNCTION__, q->fs, q->_si);
491 FREE_PKT(m);
492 return 1;
493 }
494 f = &(q->fs->fs);
495 ni = &q->_si->ni;
496 len = m->m_pkthdr.len;
497 /* Update statistics, then check reasons to drop pkt. */
498 q->ni.tot_bytes += len;
499 q->ni.tot_pkts++;
500 ni->tot_bytes += len;
501 ni->tot_pkts++;
502 if (drop)
503 goto drop;
504 if (f->plr[0] || f->plr[1]) {
505 if (__predict_true(f->plr[1] == 0)) {
506 if (random() < f->plr[0])
507 goto drop;
508 } else {
509 switch (f->pl_state) {
510 case PLR_STATE_B:
511 if (random() < f->plr[3])
512 f->pl_state = PLR_STATE_G;
513 if (random() < f->plr[2])
514 goto drop;
515 break;
516 case PLR_STATE_G: /* FALLTHROUGH */
517 default:
518 if (random() < f->plr[1])
519 f->pl_state = PLR_STATE_B;
520 if (random() < f->plr[0])
521 goto drop;
522 break;
523 }
524 }
525 }
526 if (m->m_pkthdr.rcvif != NULL)
527 m_rcvif_serialize(m);
528 #ifdef NEW_AQM
529 /* Call AQM enqueue function */
530 if (q->fs->aqmfp)
531 return q->fs->aqmfp->enqueue(q ,m);
532 #endif
533 if (f->flags & DN_IS_RED && red_drops(q, m->m_pkthdr.len)) {
534 if (!(f->flags & DN_IS_ECN) || !ecn_mark(m))
535 goto drop;
536 }
537 if (f->flags & DN_QSIZE_BYTES) {
538 if (q->ni.len_bytes > f->qsize)
539 goto drop;
540 } else if (q->ni.length >= f->qsize) {
541 goto drop;
542 }
543 mq_append(&q->mq, m);
544 q->ni.length++;
545 q->ni.len_bytes += len;
546 ni->length++;
547 ni->len_bytes += len;
548 return (0);
549
550 drop:
551 V_dn_cfg.io_pkt_drop++;
552 SDT_PROBE2(dummynet, , , drop, m, q);
553 q->ni.drops++;
554 ni->drops++;
555 FREE_PKT(m);
556 return (1);
557 }
558
559 /*
560 * Fetch packets from the delay line which are due now. If there are
561 * leftover packets, reinsert the delay line in the heap.
562 * Runs under scheduler lock.
563 */
564 static void
transmit_event(struct mq * q,struct delay_line * dline,uint64_t now)565 transmit_event(struct mq *q, struct delay_line *dline, uint64_t now)
566 {
567 struct mbuf *m;
568 struct dn_pkt_tag *pkt = NULL;
569
570 dline->oid.subtype = 0; /* not in heap */
571 while ((m = dline->mq.head) != NULL) {
572 pkt = dn_tag_get(m);
573 if (!DN_KEY_LEQ(pkt->output_time, now))
574 break;
575 dline->mq.head = m->m_nextpkt;
576 dline->mq.count--;
577 if (m->m_pkthdr.rcvif != NULL &&
578 __predict_false(m_rcvif_restore(m) == NULL))
579 m_freem(m);
580 else
581 mq_append(q, m);
582 }
583 if (m != NULL) {
584 dline->oid.subtype = 1; /* in heap */
585 heap_insert(&V_dn_cfg.evheap, pkt->output_time, dline);
586 }
587 }
588
589 /*
590 * Convert the additional MAC overheads/delays into an equivalent
591 * number of bits for the given data rate. The samples are
592 * in milliseconds so we need to divide by 1000.
593 */
594 static uint64_t
extra_bits(struct mbuf * m,struct dn_schk * s)595 extra_bits(struct mbuf *m, struct dn_schk *s)
596 {
597 int index;
598 uint64_t bits;
599 struct dn_profile *pf = s->profile;
600
601 if (!pf || pf->samples_no == 0)
602 return 0;
603 index = random() % pf->samples_no;
604 bits = div64((uint64_t)pf->samples[index] * s->link.bandwidth, 1000);
605 if (index >= pf->loss_level) {
606 struct dn_pkt_tag *dt = dn_tag_get(m);
607 if (dt)
608 dt->dn_dir = DIR_DROP;
609 }
610 return bits;
611 }
612
613 /*
614 * Send traffic from a scheduler instance due by 'now'.
615 * Return a pointer to the head of the queue.
616 */
617 static struct mbuf *
serve_sched(struct mq * q,struct dn_sch_inst * si,uint64_t now)618 serve_sched(struct mq *q, struct dn_sch_inst *si, uint64_t now)
619 {
620 struct mq def_q;
621 struct dn_schk *s = si->sched;
622 struct mbuf *m = NULL;
623 int delay_line_idle = (si->dline.mq.head == NULL);
624 int done;
625 uint32_t bw;
626
627 if (q == NULL) {
628 q = &def_q;
629 q->head = NULL;
630 }
631
632 bw = s->link.bandwidth;
633 si->kflags &= ~DN_ACTIVE;
634
635 if (bw > 0)
636 si->credit += (now - si->sched_time) * bw;
637 else
638 si->credit = 0;
639 si->sched_time = now;
640 done = 0;
641 while (si->credit >= 0 && (m = s->fp->dequeue(si)) != NULL) {
642 uint64_t len_scaled;
643
644 done++;
645 len_scaled = (bw == 0) ? 0 : hz *
646 (m->m_pkthdr.len * 8 + extra_bits(m, s));
647 si->credit -= len_scaled;
648 /* Move packet in the delay line */
649 dn_tag_get(m)->output_time = V_dn_cfg.curr_time + s->link.delay ;
650 if (m->m_pkthdr.rcvif != NULL)
651 m_rcvif_serialize(m);
652 mq_append(&si->dline.mq, m);
653 }
654
655 /*
656 * If credit >= 0 the instance is idle, mark time.
657 * Otherwise put back in the heap, and adjust the output
658 * time of the last inserted packet, m, which was too early.
659 */
660 if (si->credit >= 0) {
661 si->idle_time = now;
662 } else {
663 uint64_t t;
664 KASSERT (bw > 0, ("bw=0 and credit<0 ?"));
665 t = div64(bw - 1 - si->credit, bw);
666 if (m)
667 dn_tag_get(m)->output_time += t;
668 si->kflags |= DN_ACTIVE;
669 heap_insert(&V_dn_cfg.evheap, now + t, si);
670 }
671 if (delay_line_idle && done)
672 transmit_event(q, &si->dline, now);
673 return q->head;
674 }
675
676 /*
677 * The timer handler for dummynet. Time is computed in ticks, but
678 * but the code is tolerant to the actual rate at which this is called.
679 * Once complete, the function reschedules itself for the next tick.
680 */
681 void
dummynet_task(void * context,int pending)682 dummynet_task(void *context, int pending)
683 {
684 struct timeval t;
685 struct mq q = { NULL, NULL }; /* queue to accumulate results */
686 struct epoch_tracker et;
687
688 VNET_ITERATOR_DECL(vnet_iter);
689 VNET_LIST_RLOCK();
690 NET_EPOCH_ENTER(et);
691
692 VNET_FOREACH(vnet_iter) {
693 memset(&q, 0, sizeof(struct mq));
694 CURVNET_SET(vnet_iter);
695
696 if (! V_dn_cfg.init_done) {
697 CURVNET_RESTORE();
698 continue;
699 }
700
701 DN_BH_WLOCK();
702
703 /* Update number of lost(coalesced) ticks. */
704 V_dn_cfg.tick_lost += pending - 1;
705
706 getmicrouptime(&t);
707 /* Last tick duration (usec). */
708 V_dn_cfg.tick_last = (t.tv_sec - V_dn_cfg.prev_t.tv_sec) * 1000000 +
709 (t.tv_usec - V_dn_cfg.prev_t.tv_usec);
710 /* Last tick vs standard tick difference (usec). */
711 V_dn_cfg.tick_delta = (V_dn_cfg.tick_last * hz - 1000000) / hz;
712 /* Accumulated tick difference (usec). */
713 V_dn_cfg.tick_delta_sum += V_dn_cfg.tick_delta;
714
715 V_dn_cfg.prev_t = t;
716
717 /*
718 * Adjust curr_time if the accumulated tick difference is
719 * greater than the 'standard' tick. Since curr_time should
720 * be monotonically increasing, we do positive adjustments
721 * as required, and throttle curr_time in case of negative
722 * adjustment.
723 */
724 V_dn_cfg.curr_time++;
725 if (V_dn_cfg.tick_delta_sum - tick >= 0) {
726 int diff = V_dn_cfg.tick_delta_sum / tick;
727
728 V_dn_cfg.curr_time += diff;
729 V_dn_cfg.tick_diff += diff;
730 V_dn_cfg.tick_delta_sum %= tick;
731 V_dn_cfg.tick_adjustment++;
732 } else if (V_dn_cfg.tick_delta_sum + tick <= 0) {
733 V_dn_cfg.curr_time--;
734 V_dn_cfg.tick_diff--;
735 V_dn_cfg.tick_delta_sum += tick;
736 V_dn_cfg.tick_adjustment++;
737 }
738
739 /* serve pending events, accumulate in q */
740 for (;;) {
741 struct dn_id *p; /* generic parameter to handler */
742
743 if (V_dn_cfg.evheap.elements == 0 ||
744 DN_KEY_LT(V_dn_cfg.curr_time, HEAP_TOP(&V_dn_cfg.evheap)->key))
745 break;
746 p = HEAP_TOP(&V_dn_cfg.evheap)->object;
747 heap_extract(&V_dn_cfg.evheap, NULL);
748 if (p->type == DN_SCH_I) {
749 serve_sched(&q, (struct dn_sch_inst *)p, V_dn_cfg.curr_time);
750 } else { /* extracted a delay line */
751 transmit_event(&q, (struct delay_line *)p, V_dn_cfg.curr_time);
752 }
753 }
754 if (V_dn_cfg.expire && ++V_dn_cfg.expire_cycle >= V_dn_cfg.expire) {
755 V_dn_cfg.expire_cycle = 0;
756 dn_drain_scheduler();
757 dn_drain_queue();
758 }
759 DN_BH_WUNLOCK();
760 if (q.head != NULL)
761 dummynet_send(q.head);
762
763 CURVNET_RESTORE();
764 }
765 NET_EPOCH_EXIT(et);
766 VNET_LIST_RUNLOCK();
767
768 /* Schedule our next run. */
769 dn_reschedule();
770 }
771
772 /*
773 * forward a chain of packets to the proper destination.
774 * This runs outside the dummynet lock.
775 */
776 static void
dummynet_send(struct mbuf * m)777 dummynet_send(struct mbuf *m)
778 {
779 struct mbuf *n;
780
781 NET_EPOCH_ASSERT();
782
783 for (; m != NULL; m = n) {
784 struct ifnet *ifp = NULL; /* gcc 3.4.6 complains */
785 struct m_tag *tag;
786 int dst;
787
788 n = m->m_nextpkt;
789 m->m_nextpkt = NULL;
790 tag = m_tag_first(m);
791 if (tag == NULL) { /* should not happen */
792 dst = DIR_DROP;
793 } else {
794 struct dn_pkt_tag *pkt = dn_tag_get(m);
795 /* extract the dummynet info, rename the tag
796 * to carry reinject info.
797 */
798 ifp = ifnet_byindexgen(pkt->if_index, pkt->if_idxgen);
799 if (((pkt->dn_dir == (DIR_OUT | PROTO_LAYER2)) ||
800 (pkt->dn_dir == (DIR_OUT | PROTO_LAYER2 | PROTO_IPV6))) &&
801 ifp == NULL) {
802 dst = DIR_DROP;
803 } else {
804 dst = pkt->dn_dir;
805 tag->m_tag_cookie = MTAG_IPFW_RULE;
806 tag->m_tag_id = 0;
807 }
808 }
809
810 switch (dst) {
811 case DIR_OUT:
812 ip_output(m, NULL, NULL, IP_FORWARDING, NULL, NULL);
813 break ;
814
815 case DIR_IN :
816 netisr_dispatch(NETISR_IP, m);
817 break;
818
819 #ifdef INET6
820 case DIR_IN | PROTO_IPV6:
821 netisr_dispatch(NETISR_IPV6, m);
822 break;
823
824 case DIR_OUT | PROTO_IPV6:
825 ip6_output(m, NULL, NULL, IPV6_FORWARDING, NULL, NULL, NULL);
826 break;
827 #endif
828
829 case DIR_FWD | PROTO_IFB: /* DN_TO_IFB_FWD: */
830 if (bridge_dn_p != NULL)
831 ((*bridge_dn_p)(m, ifp));
832 else
833 printf("dummynet: if_bridge not loaded\n");
834
835 break;
836
837 case DIR_IN | PROTO_LAYER2 | PROTO_IPV6:
838 case DIR_IN | PROTO_LAYER2: /* DN_TO_ETH_DEMUX: */
839 /*
840 * The Ethernet code assumes the Ethernet header is
841 * contiguous in the first mbuf header.
842 * Insure this is true.
843 */
844 if (m->m_len < ETHER_HDR_LEN &&
845 (m = m_pullup(m, ETHER_HDR_LEN)) == NULL) {
846 printf("dummynet/ether: pullup failed, "
847 "dropping packet\n");
848 break;
849 }
850 ether_demux(m->m_pkthdr.rcvif, m);
851 break;
852
853 case DIR_OUT | PROTO_LAYER2 | PROTO_IPV6:
854 case DIR_OUT | PROTO_LAYER2: /* DN_TO_ETH_OUT: */
855 MPASS(ifp != NULL);
856 ether_output_frame(ifp, m);
857 break;
858
859 case DIR_DROP:
860 /* drop the packet after some time */
861 FREE_PKT(m);
862 break;
863
864 default:
865 printf("dummynet: bad switch %d!\n", dst);
866 FREE_PKT(m);
867 break;
868 }
869 }
870 }
871
872 static inline int
tag_mbuf(struct mbuf * m,int dir,struct ip_fw_args * fwa)873 tag_mbuf(struct mbuf *m, int dir, struct ip_fw_args *fwa)
874 {
875 struct dn_pkt_tag *dt;
876 struct m_tag *mtag;
877
878 mtag = m_tag_get(PACKET_TAG_DUMMYNET,
879 sizeof(*dt), M_NOWAIT | M_ZERO);
880 if (mtag == NULL)
881 return 1; /* Cannot allocate packet header. */
882 m_tag_prepend(m, mtag); /* Attach to mbuf chain. */
883 dt = (struct dn_pkt_tag *)(mtag + 1);
884 dt->rule = fwa->rule;
885 /* only keep this info */
886 dt->rule.info &= (IPFW_ONEPASS | IPFW_IS_DUMMYNET);
887 dt->dn_dir = dir;
888 if (fwa->flags & IPFW_ARGS_OUT && fwa->ifp != NULL) {
889 NET_EPOCH_ASSERT();
890 dt->if_index = fwa->ifp->if_index;
891 dt->if_idxgen = fwa->ifp->if_idxgen;
892 }
893 /* dt->output_time is updated as we move through */
894 dt->output_time = V_dn_cfg.curr_time;
895 dt->iphdr_off = (dir & PROTO_LAYER2) ? ETHER_HDR_LEN : 0;
896 return 0;
897 }
898
899 /*
900 * dummynet hook for packets.
901 * We use the argument to locate the flowset fs and the sched_set sch
902 * associated to it. The we apply flow_mask and sched_mask to
903 * determine the queue and scheduler instances.
904 */
905 int
dummynet_io(struct mbuf ** m0,struct ip_fw_args * fwa)906 dummynet_io(struct mbuf **m0, struct ip_fw_args *fwa)
907 {
908 struct mbuf *m = *m0;
909 struct dn_fsk *fs = NULL;
910 struct dn_sch_inst *si;
911 struct dn_queue *q = NULL; /* default */
912 int fs_id, dir;
913
914 fs_id = (fwa->rule.info & IPFW_INFO_MASK) +
915 ((fwa->rule.info & IPFW_IS_PIPE) ? 2*DN_MAX_ID : 0);
916 /* XXXGL: convert args to dir */
917 if (fwa->flags & IPFW_ARGS_IN)
918 dir = DIR_IN;
919 else
920 dir = DIR_OUT;
921 if (fwa->flags & IPFW_ARGS_ETHER)
922 dir |= PROTO_LAYER2;
923 else if (fwa->flags & IPFW_ARGS_IP6)
924 dir |= PROTO_IPV6;
925 DN_BH_WLOCK();
926 V_dn_cfg.io_pkt++;
927 /* we could actually tag outside the lock, but who cares... */
928 if (tag_mbuf(m, dir, fwa))
929 goto dropit;
930 /* XXX locate_flowset could be optimised with a direct ref. */
931 fs = dn_ht_find(V_dn_cfg.fshash, fs_id, 0, NULL);
932 if (fs == NULL)
933 goto dropit; /* This queue/pipe does not exist! */
934 if (fs->sched == NULL) /* should not happen */
935 goto dropit;
936 /* find scheduler instance, possibly applying sched_mask */
937 si = ipdn_si_find(fs->sched, &(fwa->f_id));
938 if (si == NULL)
939 goto dropit;
940 /*
941 * If the scheduler supports multiple queues, find the right one
942 * (otherwise it will be ignored by enqueue).
943 */
944 if (fs->sched->fp->flags & DN_MULTIQUEUE) {
945 q = ipdn_q_find(fs, si, &(fwa->f_id));
946 if (q == NULL)
947 goto dropit;
948 }
949 if (fs->sched->fp->enqueue(si, q, m)) {
950 /* packet was dropped by enqueue() */
951 m = *m0 = NULL;
952
953 /* dn_enqueue already increases io_pkt_drop */
954 V_dn_cfg.io_pkt_drop--;
955
956 goto dropit;
957 }
958
959 if (si->kflags & DN_ACTIVE) {
960 m = *m0 = NULL; /* consumed */
961 goto done; /* already active, nothing to do */
962 }
963
964 /* compute the initial allowance */
965 if (si->idle_time < V_dn_cfg.curr_time) {
966 /* Do this only on the first packet on an idle pipe */
967 struct dn_link *p = &fs->sched->link;
968
969 si->sched_time = V_dn_cfg.curr_time;
970 si->credit = V_dn_cfg.io_fast ? p->bandwidth : 0;
971 if (p->burst) {
972 uint64_t burst = (V_dn_cfg.curr_time - si->idle_time) * p->bandwidth;
973 if (burst > p->burst)
974 burst = p->burst;
975 si->credit += burst;
976 }
977 }
978 /* pass through scheduler and delay line */
979 m = serve_sched(NULL, si, V_dn_cfg.curr_time);
980
981 /* optimization -- pass it back to ipfw for immediate send */
982 /* XXX Don't call dummynet_send() if scheduler return the packet
983 * just enqueued. This avoid a lock order reversal.
984 *
985 */
986 if (/*V_dn_cfg.io_fast &&*/ m == *m0 && (dir & PROTO_LAYER2) == 0 ) {
987 /* fast io, rename the tag * to carry reinject info. */
988 struct m_tag *tag = m_tag_first(m);
989
990 tag->m_tag_cookie = MTAG_IPFW_RULE;
991 tag->m_tag_id = 0;
992 V_dn_cfg.io_pkt_fast++;
993 if (m->m_nextpkt != NULL) {
994 printf("dummynet: fast io: pkt chain detected!\n");
995 m->m_nextpkt = NULL;
996 }
997 m = NULL;
998 } else {
999 *m0 = NULL;
1000 }
1001 done:
1002 DN_BH_WUNLOCK();
1003 if (m)
1004 dummynet_send(m);
1005 return 0;
1006
1007 dropit:
1008 V_dn_cfg.io_pkt_drop++;
1009 SDT_PROBE2(dummynet, , , drop, m, q);
1010 DN_BH_WUNLOCK();
1011 if (m)
1012 FREE_PKT(m);
1013 *m0 = NULL;
1014 return (fs && (fs->fs.flags & DN_NOERROR)) ? 0 : ENOBUFS;
1015 }
1016