tc: support the netem seed parameter for loss and corruption events

Signed-off-by: François Michel <francois.michel@uclouvain.be>
Signed-off-by: David Ahern <dsahern@kernel.org>

diff --git a/tc/q_netem.c b/tc/q_netem.c
index 8ace2b614284ab53f2c526f0de2ba5ad9c5ddaba..febddd495e446aba57000efb94572804b3105926 100644 (file)
--- 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);
@@ -823,6 +846,9 @@ 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);
+
        print_bool(PRINT_JSON, "ecn", NULL, ecn);
        if (ecn)
                print_bool(PRINT_FP, NULL, " ecn ", ecn);