From 9c87b2aeccf174bce220e527d48391439981273b Mon Sep 17 00:00:00 2001 From: =?utf8?q?Fran=C3=A7ois=20Michel?= Date: Tue, 15 Aug 2023 11:23:39 +0200 Subject: [PATCH] netem: use a seeded PRNG for generating random losses MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Use prandom_u32_state() instead of get_random_u32() to generate the random loss events of netem. The state of the prng is part of the prng attribute of struct netem_sched_data. Signed-off-by: François Michel Reviewed-by: Simon Horman Acked-by: Stephen Hemminger Link: https://lore.kernel.org/r/20230815092348.1449179-3-francois.michel@uclouvain.be Signed-off-by: Jakub Kicinski --- net/sched/sch_netem.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c index 621c6ac..8b54b10 100644 --- a/net/sched/sch_netem.c +++ b/net/sched/sch_netem.c @@ -206,7 +206,7 @@ static u32 get_crandom(struct crndstate *state) static bool loss_4state(struct netem_sched_data *q) { struct clgstate *clg = &q->clg; - u32 rnd = get_random_u32(); + u32 rnd = prandom_u32_state(&q->prng.prng_state); /* * Makes a comparison between rnd and the transition @@ -271,18 +271,19 @@ static bool loss_4state(struct netem_sched_data *q) static bool loss_gilb_ell(struct netem_sched_data *q) { struct clgstate *clg = &q->clg; + struct rnd_state *s = &q->prng.prng_state; switch (clg->state) { case GOOD_STATE: - if (get_random_u32() < clg->a1) + if (prandom_u32_state(s) < clg->a1) clg->state = BAD_STATE; - if (get_random_u32() < clg->a4) + if (prandom_u32_state(s) < clg->a4) return true; break; case BAD_STATE: - if (get_random_u32() < clg->a2) + if (prandom_u32_state(s) < clg->a2) clg->state = GOOD_STATE; - if (get_random_u32() > clg->a3) + if (prandom_u32_state(s) > clg->a3) return true; } -- 2.7.4