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authorFrançois Michel <francois.michel@uclouvain.be>2023-08-15 12:23:39 +0300
committerJakub Kicinski <kuba@kernel.org>2023-08-18 05:15:05 +0300
commit9c87b2aeccf174bce220e527d48391439981273b (patch)
tree20b51823c6840055659ef4fd5b162d5c1f622cc8 /net/sched
parent4072d97ddc447ce9dd8f7a39cdf6f92d2031bb01 (diff)
downloadlinux-9c87b2aeccf174bce220e527d48391439981273b.tar.xz
netem: use a seeded PRNG for generating random losses
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 <francois.michel@uclouvain.be> Reviewed-by: Simon Horman <horms@kernel.org> Acked-by: Stephen Hemminger <stephen@networkplumber.org> Link: https://lore.kernel.org/r/20230815092348.1449179-3-francois.michel@uclouvain.be Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/sched')
-rw-r--r--net/sched/sch_netem.c11
1 files changed, 6 insertions, 5 deletions
diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c
index 621c6acfd644..8b54b1005a10 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;
}