Lines Matching +full:link +full:- +full:loss +full:- +full:low
1 // SPDX-License-Identifier: GPL-2.0-only
35 Sources: [1] Mark Carson, Darrin Santay, "NIST Net - A Linux-based
39 ----------------------------------------------------------------
46 normal, Pareto, or experimental curves. Packet loss,
54 Correlated Loss Generator models
56 Added generation of correlated loss according to the
57 "Gilbert-Elliot" model, a 4-state markov model.
62 and intuitive loss model for packet networks and its implementation
75 /* internal t(ime)fifo qdisc uses t_root and sch->limit */
78 /* a linear queue; reduces rbtree rebalancing when jitter is low */
92 u32 loss; member
136 /* Correlated Loss Generation models */
141 /* 4-states and Gilbert-Elliot models */
142 u32 a1; /* p13 for 4-states or p for GE */
143 u32 a2; /* p31 for 4-states or r for GE */
144 u32 a3; /* p32 for 4-states or h for GE */
145 u32 a4; /* p14 for 4-states or 1-k for GE */
146 u32 a5; /* p23 used only in 4-states */
162 * As skb->rbnode uses same storage than skb->next, skb->prev and skb->tstamp,
163 * and skb->next & skb->prev are scratch space for a qdisc,
164 * we save skb->tstamp value in skb->cb[] before destroying it.
174 return (struct netem_skb_cb *)qdisc_skb_cb(skb)->data; in netem_skb_cb()
177 /* init_crandom - initialize correlated random number generator
182 state->rho = rho; in init_crandom()
183 state->last = get_random_u32(); in init_crandom()
186 /* get_crandom - correlated random number generator
194 struct rnd_state *s = &p->prng_state; in get_crandom()
196 if (!state || state->rho == 0) /* no correlation */ in get_crandom()
200 rho = (u64)state->rho + 1; in get_crandom()
201 answer = (value * ((1ull<<32) - rho) + state->last * rho) >> 32; in get_crandom()
202 state->last = answer; in get_crandom()
206 /* loss_4state - 4-state model loss generator
207 * Generates losses according to the 4-state Markov chain adopted in
208 * the GI (General and Intuitive) loss model.
212 struct clgstate *clg = &q->clg; in loss_4state()
213 u32 rnd = prandom_u32_state(&q->prng.prng_state); in loss_4state()
225 switch (clg->state) { in loss_4state()
227 if (rnd < clg->a4) { in loss_4state()
228 clg->state = LOST_IN_GAP_PERIOD; in loss_4state()
230 } else if (clg->a4 < rnd && rnd < clg->a1 + clg->a4) { in loss_4state()
231 clg->state = LOST_IN_BURST_PERIOD; in loss_4state()
233 } else if (clg->a1 + clg->a4 < rnd) { in loss_4state()
234 clg->state = TX_IN_GAP_PERIOD; in loss_4state()
239 if (rnd < clg->a5) { in loss_4state()
240 clg->state = LOST_IN_BURST_PERIOD; in loss_4state()
243 clg->state = TX_IN_BURST_PERIOD; in loss_4state()
248 if (rnd < clg->a3) in loss_4state()
249 clg->state = TX_IN_BURST_PERIOD; in loss_4state()
250 else if (clg->a3 < rnd && rnd < clg->a2 + clg->a3) { in loss_4state()
251 clg->state = TX_IN_GAP_PERIOD; in loss_4state()
252 } else if (clg->a2 + clg->a3 < rnd) { in loss_4state()
253 clg->state = LOST_IN_BURST_PERIOD; in loss_4state()
258 clg->state = TX_IN_GAP_PERIOD; in loss_4state()
265 /* loss_gilb_ell - Gilbert-Elliot model loss generator
266 * Generates losses according to the Gilbert-Elliot loss model or
272 * with the loss probability of the current state decides if the next
277 struct clgstate *clg = &q->clg; in loss_gilb_ell()
278 struct rnd_state *s = &q->prng.prng_state; in loss_gilb_ell()
280 switch (clg->state) { in loss_gilb_ell()
282 if (prandom_u32_state(s) < clg->a1) in loss_gilb_ell()
283 clg->state = BAD_STATE; in loss_gilb_ell()
284 if (prandom_u32_state(s) < clg->a4) in loss_gilb_ell()
288 if (prandom_u32_state(s) < clg->a2) in loss_gilb_ell()
289 clg->state = GOOD_STATE; in loss_gilb_ell()
290 if (prandom_u32_state(s) > clg->a3) in loss_gilb_ell()
299 switch (q->loss_model) { in loss_event()
302 return q->loss && q->loss >= get_crandom(&q->loss_cor, &q->prng); in loss_event()
305 /* 4state loss model algorithm (used also for GI model) in loss_event()
306 * Extracts a value from the markov 4 state loss generator, in loss_event()
313 /* Gilbert-Elliot loss model algorithm in loss_event()
314 * Extracts a value from the Gilbert-Elliot loss generator, in loss_event()
325 /* tabledist - return a pseudo-randomly distributed value with mean mu and
327 * distribution, and a uniformly-distributed pseudo-random source.
345 return ((rnd % (2 * (u32)sigma)) + mu) - sigma; in tabledist()
347 t = dist->table[rnd % dist->size]; in tabledist()
352 x -= NETEM_DIST_SCALE/2; in tabledist()
359 len += q->packet_overhead; in packet_time_ns()
361 if (q->cell_size) { in packet_time_ns()
362 u32 cells = reciprocal_divide(len, q->cell_size_reciprocal); in packet_time_ns()
364 if (len > cells * q->cell_size) /* extra cell needed for remainder */ in packet_time_ns()
366 len = cells * (q->cell_size + q->cell_overhead); in packet_time_ns()
369 return div64_u64(len * NSEC_PER_SEC, q->rate); in packet_time_ns()
375 struct rb_node *p = rb_first(&q->t_root); in tfifo_reset()
381 rb_erase(&skb->rbnode, &q->t_root); in tfifo_reset()
385 rtnl_kfree_skbs(q->t_head, q->t_tail); in tfifo_reset()
386 q->t_head = NULL; in tfifo_reset()
387 q->t_tail = NULL; in tfifo_reset()
388 q->t_len = 0; in tfifo_reset()
394 u64 tnext = netem_skb_cb(nskb)->time_to_send; in tfifo_enqueue()
396 if (!q->t_tail || tnext >= netem_skb_cb(q->t_tail)->time_to_send) { in tfifo_enqueue()
397 if (q->t_tail) in tfifo_enqueue()
398 q->t_tail->next = nskb; in tfifo_enqueue()
400 q->t_head = nskb; in tfifo_enqueue()
401 q->t_tail = nskb; in tfifo_enqueue()
403 struct rb_node **p = &q->t_root.rb_node, *parent = NULL; in tfifo_enqueue()
410 if (tnext >= netem_skb_cb(skb)->time_to_send) in tfifo_enqueue()
411 p = &parent->rb_right; in tfifo_enqueue()
413 p = &parent->rb_left; in tfifo_enqueue()
415 rb_link_node(&nskb->rbnode, parent, p); in tfifo_enqueue()
416 rb_insert_color(&nskb->rbnode, &q->t_root); in tfifo_enqueue()
418 q->t_len++; in tfifo_enqueue()
419 sch->q.qlen++; in tfifo_enqueue()
424 * the first packet to be corrupted, and re-enqueue the remaining frames
460 skb->prev = NULL; in netem_enqueue()
463 if (q->duplicate && q->duplicate >= get_crandom(&q->dup_cor, &q->prng)) in netem_enqueue()
468 if (q->ecn && INET_ECN_set_ce(skb)) in netem_enqueue()
471 --count; in netem_enqueue()
480 * place at TX completion time, so _before_ the link transit delay) in netem_enqueue()
482 if (q->latency || q->jitter || q->rate) in netem_enqueue()
498 if (q->corrupt && q->corrupt >= get_crandom(&q->corrupt_cor, &q->prng)) { in netem_enqueue()
504 segs = skb->next; in netem_enqueue()
506 qdisc_skb_cb(skb)->pkt_len = skb->len; in netem_enqueue()
514 if (skb->ip_summed == CHECKSUM_PARTIAL && in netem_enqueue()
521 skb->data[get_random_u32_below(skb_headlen(skb))] ^= in netem_enqueue()
525 if (unlikely(q->t_len >= sch->limit)) { in netem_enqueue()
526 /* re-link segs, so that qdisc_drop_all() frees them all */ in netem_enqueue()
527 skb->next = segs; in netem_enqueue()
535 * If doing duplication then re-insert at top of the in netem_enqueue()
541 u32 dupsave = q->duplicate; /* prevent duplicating a dup... */ in netem_enqueue()
543 q->duplicate = 0; in netem_enqueue()
544 rootq->enqueue(skb2, rootq, to_free); in netem_enqueue()
545 q->duplicate = dupsave; in netem_enqueue()
552 if (q->gap == 0 || /* not doing reordering */ in netem_enqueue()
553 q->counter < q->gap - 1 || /* inside last reordering gap */ in netem_enqueue()
554 q->reorder < get_crandom(&q->reorder_cor, &q->prng)) { in netem_enqueue()
558 delay = tabledist(q->latency, q->jitter, in netem_enqueue()
559 &q->delay_cor, &q->prng, q->delay_dist); in netem_enqueue()
563 if (q->rate) { in netem_enqueue()
566 if (sch->q.tail) in netem_enqueue()
567 last = netem_skb_cb(sch->q.tail); in netem_enqueue()
568 if (q->t_root.rb_node) { in netem_enqueue()
572 t_skb = skb_rb_last(&q->t_root); in netem_enqueue()
575 t_last->time_to_send > last->time_to_send) in netem_enqueue()
578 if (q->t_tail) { in netem_enqueue()
580 netem_skb_cb(q->t_tail); in netem_enqueue()
583 t_last->time_to_send > last->time_to_send) in netem_enqueue()
593 delay -= last->time_to_send - now; in netem_enqueue()
595 now = last->time_to_send; in netem_enqueue()
601 cb->time_to_send = now + delay; in netem_enqueue()
602 ++q->counter; in netem_enqueue()
606 * Do re-ordering by putting one out of N packets at the front in netem_enqueue()
609 cb->time_to_send = ktime_get_ns(); in netem_enqueue()
610 q->counter = 0; in netem_enqueue()
612 __qdisc_enqueue_head(skb, &sch->q); in netem_enqueue()
613 sch->qstats.requeues++; in netem_enqueue()
624 len = skb ? skb->len : 0; in netem_enqueue()
628 skb2 = segs->next; in netem_enqueue()
630 qdisc_skb_cb(segs)->pkt_len = segs->len; in netem_enqueue()
631 last_len = segs->len; in netem_enqueue()
643 qdisc_tree_reduce_backlog(sch, -(nb - 1), -(len - prev_len)); in netem_enqueue()
658 if (!q->slot_dist) in get_slot_next()
659 next_delay = q->slot_config.min_delay + in get_slot_next()
661 (q->slot_config.max_delay - in get_slot_next()
662 q->slot_config.min_delay) >> 32); in get_slot_next()
664 next_delay = tabledist(q->slot_config.dist_delay, in get_slot_next()
665 (s32)(q->slot_config.dist_jitter), in get_slot_next()
666 NULL, &q->prng, q->slot_dist); in get_slot_next()
668 q->slot.slot_next = now + next_delay; in get_slot_next()
669 q->slot.packets_left = q->slot_config.max_packets; in get_slot_next()
670 q->slot.bytes_left = q->slot_config.max_bytes; in get_slot_next()
675 struct sk_buff *skb = skb_rb_first(&q->t_root); in netem_peek()
679 return q->t_head; in netem_peek()
680 if (!q->t_head) in netem_peek()
683 t1 = netem_skb_cb(skb)->time_to_send; in netem_peek()
684 t2 = netem_skb_cb(q->t_head)->time_to_send; in netem_peek()
687 return q->t_head; in netem_peek()
692 if (skb == q->t_head) { in netem_erase_head()
693 q->t_head = skb->next; in netem_erase_head()
694 if (!q->t_head) in netem_erase_head()
695 q->t_tail = NULL; in netem_erase_head()
697 rb_erase(&skb->rbnode, &q->t_root); in netem_erase_head()
707 skb = __qdisc_dequeue_head(&sch->q); in netem_dequeue()
720 time_to_send = netem_skb_cb(skb)->time_to_send; in netem_dequeue()
721 if (q->slot.slot_next && q->slot.slot_next < time_to_send) in netem_dequeue()
724 if (time_to_send <= now && q->slot.slot_next <= now) { in netem_dequeue()
726 q->t_len--; in netem_dequeue()
727 skb->next = NULL; in netem_dequeue()
728 skb->prev = NULL; in netem_dequeue()
729 /* skb->dev shares skb->rbnode area, in netem_dequeue()
732 skb->dev = qdisc_dev(sch); in netem_dequeue()
734 if (q->slot.slot_next) { in netem_dequeue()
735 q->slot.packets_left--; in netem_dequeue()
736 q->slot.bytes_left -= qdisc_pkt_len(skb); in netem_dequeue()
737 if (q->slot.packets_left <= 0 || in netem_dequeue()
738 q->slot.bytes_left <= 0) in netem_dequeue()
742 if (q->qdisc) { in netem_dequeue()
747 err = qdisc_enqueue(skb, q->qdisc, &to_free); in netem_dequeue()
752 sch->qstats.backlog -= pkt_len; in netem_dequeue()
753 sch->q.qlen--; in netem_dequeue()
758 sch->q.qlen--; in netem_dequeue()
762 if (q->qdisc) { in netem_dequeue()
763 skb = q->qdisc->ops->dequeue(q->qdisc); in netem_dequeue()
765 sch->q.qlen--; in netem_dequeue()
770 qdisc_watchdog_schedule_ns(&q->watchdog, in netem_dequeue()
772 q->slot.slot_next)); in netem_dequeue()
775 if (q->qdisc) { in netem_dequeue()
776 skb = q->qdisc->ops->dequeue(q->qdisc); in netem_dequeue()
778 sch->q.qlen--; in netem_dequeue()
791 if (q->qdisc) in netem_reset()
792 qdisc_reset(q->qdisc); in netem_reset()
793 qdisc_watchdog_cancel(&q->watchdog); in netem_reset()
814 return -EINVAL; in get_dist_table()
818 return -ENOMEM; in get_dist_table()
820 d->size = n; in get_dist_table()
822 d->table[i] = data[i]; in get_dist_table()
832 q->slot_config = *c; in get_slot()
833 if (q->slot_config.max_packets == 0) in get_slot()
834 q->slot_config.max_packets = INT_MAX; in get_slot()
835 if (q->slot_config.max_bytes == 0) in get_slot()
836 q->slot_config.max_bytes = INT_MAX; in get_slot()
839 q->slot_config.dist_jitter = min_t(__s64, INT_MAX, abs(q->slot_config.dist_jitter)); in get_slot()
841 q->slot.packets_left = q->slot_config.max_packets; in get_slot()
842 q->slot.bytes_left = q->slot_config.max_bytes; in get_slot()
843 if (q->slot_config.min_delay | q->slot_config.max_delay | in get_slot()
844 q->slot_config.dist_jitter) in get_slot()
845 q->slot.slot_next = ktime_get_ns(); in get_slot()
847 q->slot.slot_next = 0; in get_slot()
854 init_crandom(&q->delay_cor, c->delay_corr); in get_correlation()
855 init_crandom(&q->loss_cor, c->loss_corr); in get_correlation()
856 init_crandom(&q->dup_cor, c->dup_corr); in get_correlation()
863 q->reorder = r->probability; in get_reorder()
864 init_crandom(&q->reorder_cor, r->correlation); in get_reorder()
871 q->corrupt = r->probability; in get_corrupt()
872 init_crandom(&q->corrupt_cor, r->correlation); in get_corrupt()
879 q->rate = r->rate; in get_rate()
880 q->packet_overhead = r->packet_overhead; in get_rate()
881 q->cell_size = r->cell_size; in get_rate()
882 q->cell_overhead = r->cell_overhead; in get_rate()
883 if (q->cell_size) in get_rate()
884 q->cell_size_reciprocal = reciprocal_value(q->cell_size); in get_rate()
886 q->cell_size_reciprocal = (struct reciprocal_value) { 0 }; in get_rate()
903 return -EINVAL; in get_loss_clg()
906 q->loss_model = CLG_4_STATES; in get_loss_clg()
908 q->clg.state = TX_IN_GAP_PERIOD; in get_loss_clg()
909 q->clg.a1 = gi->p13; in get_loss_clg()
910 q->clg.a2 = gi->p31; in get_loss_clg()
911 q->clg.a3 = gi->p32; in get_loss_clg()
912 q->clg.a4 = gi->p14; in get_loss_clg()
913 q->clg.a5 = gi->p23; in get_loss_clg()
922 return -EINVAL; in get_loss_clg()
925 q->loss_model = CLG_GILB_ELL; in get_loss_clg()
926 q->clg.state = GOOD_STATE; in get_loss_clg()
927 q->clg.a1 = ge->p; in get_loss_clg()
928 q->clg.a2 = ge->r; in get_loss_clg()
929 q->clg.a3 = ge->h; in get_loss_clg()
930 q->clg.a4 = ge->k1; in get_loss_clg()
935 pr_info("netem: unknown loss type %u\n", type); in get_loss_clg()
936 return -EINVAL; in get_loss_clg()
960 int nested_len = nla_len(nla) - NLA_ALIGN(len); in parse_attr()
964 return -EINVAL; in parse_attr()
1007 /* backup q->clg and q->loss_model */ in netem_change()
1008 old_clg = q->clg; in netem_change()
1009 old_loss_model = q->loss_model; in netem_change()
1014 q->loss_model = old_loss_model; in netem_change()
1015 q->clg = old_clg; in netem_change()
1019 q->loss_model = CLG_RANDOM; in netem_change()
1023 swap(q->delay_dist, delay_dist); in netem_change()
1025 swap(q->slot_dist, slot_dist); in netem_change()
1026 sch->limit = qopt->limit; in netem_change()
1028 q->latency = PSCHED_TICKS2NS(qopt->latency); in netem_change()
1029 q->jitter = PSCHED_TICKS2NS(qopt->jitter); in netem_change()
1030 q->limit = qopt->limit; in netem_change()
1031 q->gap = qopt->gap; in netem_change()
1032 q->counter = 0; in netem_change()
1033 q->loss = qopt->loss; in netem_change()
1034 q->duplicate = qopt->duplicate; in netem_change()
1039 if (q->gap) in netem_change()
1040 q->reorder = ~0; in netem_change()
1055 q->rate = max_t(u64, q->rate, in netem_change()
1059 q->latency = nla_get_s64(tb[TCA_NETEM_LATENCY64]); in netem_change()
1062 q->jitter = nla_get_s64(tb[TCA_NETEM_JITTER64]); in netem_change()
1065 q->ecn = nla_get_u32(tb[TCA_NETEM_ECN]); in netem_change()
1071 q->jitter = min_t(s64, abs(q->jitter), INT_MAX); in netem_change()
1074 q->prng.seed = nla_get_u64(tb[TCA_NETEM_PRNG_SEED]); in netem_change()
1076 q->prng.seed = get_random_u64(); in netem_change()
1077 prandom_seed_state(&q->prng.prng_state, q->prng.seed); in netem_change()
1094 qdisc_watchdog_init(&q->watchdog, sch); in netem_init()
1097 return -EINVAL; in netem_init()
1099 q->loss_model = CLG_RANDOM; in netem_init()
1110 qdisc_watchdog_cancel(&q->watchdog); in netem_destroy()
1111 if (q->qdisc) in netem_destroy()
1112 qdisc_put(q->qdisc); in netem_destroy()
1113 dist_free(q->delay_dist); in netem_destroy()
1114 dist_free(q->slot_dist); in netem_destroy()
1126 switch (q->loss_model) { in dump_loss_model()
1128 /* legacy loss model */ in dump_loss_model()
1134 .p13 = q->clg.a1, in dump_loss_model()
1135 .p31 = q->clg.a2, in dump_loss_model()
1136 .p32 = q->clg.a3, in dump_loss_model()
1137 .p14 = q->clg.a4, in dump_loss_model()
1138 .p23 = q->clg.a5, in dump_loss_model()
1147 .p = q->clg.a1, in dump_loss_model()
1148 .r = q->clg.a2, in dump_loss_model()
1149 .h = q->clg.a3, in dump_loss_model()
1150 .k1 = q->clg.a4, in dump_loss_model()
1164 return -1; in dump_loss_model()
1178 qopt.latency = min_t(psched_time_t, PSCHED_NS2TICKS(q->latency), in netem_dump()
1180 qopt.jitter = min_t(psched_time_t, PSCHED_NS2TICKS(q->jitter), in netem_dump()
1182 qopt.limit = q->limit; in netem_dump()
1183 qopt.loss = q->loss; in netem_dump()
1184 qopt.gap = q->gap; in netem_dump()
1185 qopt.duplicate = q->duplicate; in netem_dump()
1189 if (nla_put(skb, TCA_NETEM_LATENCY64, sizeof(q->latency), &q->latency)) in netem_dump()
1192 if (nla_put(skb, TCA_NETEM_JITTER64, sizeof(q->jitter), &q->jitter)) in netem_dump()
1195 cor.delay_corr = q->delay_cor.rho; in netem_dump()
1196 cor.loss_corr = q->loss_cor.rho; in netem_dump()
1197 cor.dup_corr = q->dup_cor.rho; in netem_dump()
1201 reorder.probability = q->reorder; in netem_dump()
1202 reorder.correlation = q->reorder_cor.rho; in netem_dump()
1206 corrupt.probability = q->corrupt; in netem_dump()
1207 corrupt.correlation = q->corrupt_cor.rho; in netem_dump()
1211 if (q->rate >= (1ULL << 32)) { in netem_dump()
1212 if (nla_put_u64_64bit(skb, TCA_NETEM_RATE64, q->rate, in netem_dump()
1217 rate.rate = q->rate; in netem_dump()
1219 rate.packet_overhead = q->packet_overhead; in netem_dump()
1220 rate.cell_size = q->cell_size; in netem_dump()
1221 rate.cell_overhead = q->cell_overhead; in netem_dump()
1225 if (q->ecn && nla_put_u32(skb, TCA_NETEM_ECN, q->ecn)) in netem_dump()
1231 if (q->slot_config.min_delay | q->slot_config.max_delay | in netem_dump()
1232 q->slot_config.dist_jitter) { in netem_dump()
1233 slot = q->slot_config; in netem_dump()
1242 if (nla_put_u64_64bit(skb, TCA_NETEM_PRNG_SEED, q->prng.seed, in netem_dump()
1250 return -1; in netem_dump()
1258 if (cl != 1 || !q->qdisc) /* only one class */ in netem_dump_class()
1259 return -ENOENT; in netem_dump_class()
1261 tcm->tcm_handle |= TC_H_MIN(1); in netem_dump_class()
1262 tcm->tcm_info = q->qdisc->handle; in netem_dump_class()
1272 *old = qdisc_replace(sch, new, &q->qdisc); in netem_graft()
1279 return q->qdisc; in netem_leaf()
1289 if (!walker->stop) { in netem_walk()