* [PATCH iproute2-next 1/2] tc: support the netem seed parameter for loss and corruption events
2023-08-22 14:04 [PATCH iproute2-next 0/2] tc: support the netem seed parameter for loss and corruption events francois.michel
@ 2023-08-22 14:04 ` francois.michel
2023-08-22 15:43 ` Stephen Hemminger
2023-08-22 14:04 ` [PATCH iproute2-next 2/2] man: tc-netem: add section for specifying the netem seed francois.michel
1 sibling, 1 reply; 5+ messages in thread
From: francois.michel @ 2023-08-22 14:04 UTC (permalink / raw)
Cc: netdev, stephen, Francois Michel
From: François Michel <francois.michel@uclouvain.be>
Signed-off-by: François Michel <francois.michel@uclouvain.be>
---
include/uapi/linux/pkt_sched.h | 1 +
tc/q_netem.c | 26 ++++++++++++++++++++++++++
2 files changed, 27 insertions(+)
diff --git a/include/uapi/linux/pkt_sched.h b/include/uapi/linux/pkt_sched.h
index 00f6ff0a..3f85ae57 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/tc/q_netem.c b/tc/q_netem.c
index 8ace2b61..6d48081a 100644
--- a/tc/q_netem.c
+++ b/tc/q_netem.c
@@ -31,6 +31,7 @@ static void explain(void)
" [ loss random PERCENT [CORRELATION]]\n"
" [ loss state P13 [P31 [P32 [P23 P14]]]\n"
" [ loss gemodel PERCENT [R [1-H [1-K]]]\n"
+ " [ seed SEED \n]"
" [ ecn ]\n"
" [ reorder PERCENT [CORRELATION] [ gap DISTANCE ]]\n"
" [ rate RATE [PACKETOVERHEAD] [CELLSIZE] [CELLOVERHEAD]]\n"
@@ -208,6 +209,7 @@ static int netem_parse_opt(struct qdisc_util *qu, int argc, char **argv,
__u16 loss_type = NETEM_LOSS_UNSPEC;
int present[__TCA_NETEM_MAX] = {};
__u64 rate64 = 0;
+ __u64 seed = 0;
for ( ; argc > 0; --argc, ++argv) {
if (matches(*argv, "limit") == 0) {
@@ -363,6 +365,13 @@ random_loss_model:
*argv);
return -1;
}
+ } else if (matches(*argv, "seed") == 0) {
+ NEXT_ARG();
+ present[TCA_NETEM_PRNG_SEED] = 1;
+ if (get_u64(&seed, *argv, 10)) {
+ explain1("seed");
+ return -1;
+ }
} else if (matches(*argv, "ecn") == 0) {
present[TCA_NETEM_ECN] = 1;
} else if (matches(*argv, "reorder") == 0) {
@@ -627,6 +636,12 @@ random_loss_model:
return -1;
}
+ if (present[TCA_NETEM_PRNG_SEED] &&
+ addattr_l(n, 1024, TCA_NETEM_PRNG_SEED, &seed,
+ sizeof(seed)) < 0)
+ return -1;
+
+
if (dist_data) {
if (addattr_l(n, MAX_DIST * sizeof(dist_data[0]),
TCA_NETEM_DELAY_DIST,
@@ -657,6 +672,8 @@ static int netem_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
struct tc_netem_qopt qopt;
const struct tc_netem_rate *rate = NULL;
const struct tc_netem_slot *slot = NULL;
+ bool seed_present = false;
+ __u64 seed = 0;
int len;
__u64 rate64 = 0;
@@ -722,6 +739,12 @@ static int netem_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
return -1;
slot = RTA_DATA(tb[TCA_NETEM_SLOT]);
}
+ if (tb[TCA_NETEM_PRNG_SEED]) {
+ if (RTA_PAYLOAD(tb[TCA_NETEM_PRNG_SEED]) < sizeof(seed))
+ return -1;
+ seed_present = true;
+ seed = rta_getattr_u64(tb[TCA_NETEM_PRNG_SEED]);
+ }
}
print_uint(PRINT_ANY, "limit", "limit %d", qopt.limit);
@@ -795,6 +818,9 @@ static int netem_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
close_json_object();
}
+ if (seed_present)
+ print_u64(PRINT_ANY, "seed", " seed %llu", seed);
+
if (rate && rate->rate) {
open_json_object("rate");
rate64 = rate64 ? : rate->rate;
--
2.41.0
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH iproute2-next 2/2] man: tc-netem: add section for specifying the netem seed
2023-08-22 14:04 [PATCH iproute2-next 0/2] tc: support the netem seed parameter for loss and corruption events francois.michel
2023-08-22 14:04 ` [PATCH iproute2-next 1/2] " francois.michel
@ 2023-08-22 14:04 ` francois.michel
1 sibling, 0 replies; 5+ messages in thread
From: francois.michel @ 2023-08-22 14:04 UTC (permalink / raw)
Cc: netdev, stephen, Francois Michel
From: François Michel <francois.michel@uclouvain.be>
Signed-off-by: François Michel <francois.michel@uclouvain.be>
---
man/man8/tc-netem.8 | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/man/man8/tc-netem.8 b/man/man8/tc-netem.8
index bc7947da..a4cc0d61 100644
--- a/man/man8/tc-netem.8
+++ b/man/man8/tc-netem.8
@@ -9,7 +9,7 @@ netem \- Network Emulator
.IR OPTIONS " := [ " LIMIT " ] [ " DELAY " ] [ " LOSS \
" ] [ " CORRUPT " ] [ " DUPLICATION " ] [ " REORDERING " ] [ " RATE \
-" ] [ " SLOT " ]"
+" ] [ " SLOT " ] [ " SEED " ]"
.IR LIMIT " := "
.B limit
@@ -64,6 +64,10 @@ netem \- Network Emulator
.BR bytes
.IR BYTES " ]"
+.IR SEED " := "
+.B seed
+.I VALUE
+
.SH DESCRIPTION
The
.B netem
@@ -240,6 +244,11 @@ It is possible to combine slotting with a rate, in which case complex behaviors
where either the rate, or the slot limits on bytes or packets per slot, govern
the actual delivered rate.
+.TP
+.BI seed " VALUE"
+Specifies a seed to guide and reproduce the randomly generated
+loss or corruption events.
+
.SH LIMITATIONS
Netem is limited by the timer granularity in the kernel.
Rate and delay maybe impacted by clock interrupts.
--
2.41.0
^ permalink raw reply related [flat|nested] 5+ messages in thread