From 4072d97ddc447ce9dd8f7a39cdf6f92d2031bb01 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Fran=C3=A7ois=20Michel?= Date: Tue, 15 Aug 2023 11:23:38 +0200 Subject: [PATCH] netem: add prng attribute to netem_sched_data MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Add prng attribute to struct netem_sched_data and allows setting the seed of the PRNG through netlink using the new TCA_NETEM_PRNG_SEED attribute. The PRNG attribute is not actually used yet. Signed-off-by: François Michel Reviewed-by: Simon Horman Acked-by: Stephen Hemminger Link: https://lore.kernel.org/r/20230815092348.1449179-2-francois.michel@uclouvain.be Signed-off-by: Jakub Kicinski --- include/uapi/linux/pkt_sched.h | 1 + net/sched/sch_netem.c | 16 ++++++++++++++++ 2 files changed, 17 insertions(+) diff --git a/include/uapi/linux/pkt_sched.h b/include/uapi/linux/pkt_sched.h index 00f6ff0..3f85ae5 100644 --- a/include/uapi/linux/pkt_sched.h +++ b/include/uapi/linux/pkt_sched.h @@ -603,6 +603,7 @@ enum { TCA_NETEM_JITTER64, TCA_NETEM_SLOT, TCA_NETEM_SLOT_DIST, + TCA_NETEM_PRNG_SEED, __TCA_NETEM_MAX, }; diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c index 38d9aa0c..621c6ac 100644 --- a/net/sched/sch_netem.c +++ b/net/sched/sch_netem.c @@ -105,6 +105,11 @@ struct netem_sched_data { u32 rho; } delay_cor, loss_cor, dup_cor, reorder_cor, corrupt_cor; + struct prng { + u64 seed; + struct rnd_state prng_state; + } prng; + struct disttable *delay_dist; enum { @@ -922,6 +927,7 @@ static const struct nla_policy netem_policy[TCA_NETEM_MAX + 1] = { [TCA_NETEM_LATENCY64] = { .type = NLA_S64 }, [TCA_NETEM_JITTER64] = { .type = NLA_S64 }, [TCA_NETEM_SLOT] = { .len = sizeof(struct tc_netem_slot) }, + [TCA_NETEM_PRNG_SEED] = { .type = NLA_U64 }, }; static int parse_attr(struct nlattr *tb[], int maxtype, struct nlattr *nla, @@ -1040,6 +1046,12 @@ static int netem_change(struct Qdisc *sch, struct nlattr *opt, /* capping jitter to the range acceptable by tabledist() */ q->jitter = min_t(s64, abs(q->jitter), INT_MAX); + if (tb[TCA_NETEM_PRNG_SEED]) + q->prng.seed = nla_get_u64(tb[TCA_NETEM_PRNG_SEED]); + else + q->prng.seed = get_random_u64(); + prandom_seed_state(&q->prng.prng_state, q->prng.seed); + unlock: sch_tree_unlock(sch); @@ -1203,6 +1215,10 @@ static int netem_dump(struct Qdisc *sch, struct sk_buff *skb) goto nla_put_failure; } + if (nla_put_u64_64bit(skb, TCA_NETEM_PRNG_SEED, q->prng.seed, + TCA_NETEM_PAD)) + goto nla_put_failure; + return nla_nest_end(skb, nla); nla_put_failure: -- 2.7.4