tc: netem rate shaping and cell extension

This patch add rate shaping as well as cell support. The link-rate can be
specified via rate options. Three optional arguments control the cell
knobs: packet-overhead, cell-size, cell-overhead. To ratelimit eth0 root
queue to 5kbit/s, with a 20 byte packet overhead, 100 byte cell size and
a 5 byte per cell overhead:

	tc qdisc add dev eth0 root netem rate 5kbit 20 100 5

Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net>

diff --git a/tc/q_netem.c b/tc/q_netem.c
index b1fd45297c0810b3bfdcdfd8bae67afddd242f8a..cb0c8a4f6dfbb3cdaf8fdf076a5634a361765308 100644 (file)
--- a/tc/q_netem.c
+++ b/tc/q_netem.c
@@ -38,7 +38,8 @@ 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" \
-"                 [ reorder PERCENT [CORRELATION] [ gap DISTANCE ]]\n");
+"                 [ reorder PRECENT [CORRELATION] [ gap DISTANCE ]]\n" \
+"                 [ rate RATE [PACKETOVERHEAD] [CELLSIZE] [CELLOVERHEAD]]\n");
 }
 
 static void explain1(const char *arg)
@@ -175,6 +176,7 @@ static int netem_parse_opt(struct qdisc_util *qu, int argc, char **argv,
        struct tc_netem_corrupt corrupt;
        struct tc_netem_gimodel gimodel;
        struct tc_netem_gemodel gemodel;
+       struct tc_netem_rate rate;
        __s16 *dist_data = NULL;
        __u16 loss_type = NETEM_LOSS_UNSPEC;
        int present[__TCA_NETEM_MAX];
@@ -182,6 +184,7 @@ static int netem_parse_opt(struct qdisc_util *qu, int argc, char **argv,
        memset(&cor, 0, sizeof(cor));
        memset(&reorder, 0, sizeof(reorder));
        memset(&corrupt, 0, sizeof(corrupt));
+       memset(&rate, 0, sizeof(rate));
        memset(present, 0, sizeof(present));
 
        for( ; argc > 0; --argc, ++argv) {
@@ -380,6 +383,34 @@ static int netem_parse_opt(struct qdisc_util *qu, int argc, char **argv,
                                free(dist_data);
                                return -1;
                        }
+               } else if (matches(*argv, "rate") == 0) {
+                       ++present[TCA_NETEM_RATE];
+                       NEXT_ARG();
+                       if (get_rate(&rate.rate, *argv)) {
+                               explain1("rate");
+                               return -1;
+                       }
+                       if (NEXT_IS_NUMBER()) {
+                               NEXT_ARG();
+                               if (get_s32(&rate.packet_overhead, *argv, 0)) {
+                                       explain1("rate");
+                                       return -1;
+                               }
+                       }
+                       if (NEXT_IS_NUMBER()) {
+                               NEXT_ARG();
+                               if (get_u32(&rate.cell_size, *argv, 0)) {
+                                       explain1("rate");
+                                       return -1;
+                               }
+                       }
+                       if (NEXT_IS_NUMBER()) {
+                               NEXT_ARG();
+                               if (get_s32(&rate.cell_overhead, *argv, 0)) {
+                                       explain1("rate");
+                                       return -1;
+                               }
+                       }
                } else if (strcmp(*argv, "help") == 0) {
                        explain();
                        return -1;
@@ -445,6 +476,10 @@ static int netem_parse_opt(struct qdisc_util *qu, int argc, char **argv,
                addattr_nest_end(n, start);
        }
 
+       if (present[TCA_NETEM_RATE] &&
+           addattr_l(n, 1024, TCA_NETEM_RATE, &rate, sizeof(rate)) < 0)
+               return -1;
+
        if (dist_data) {
                if (addattr_l(n, MAX_DIST * sizeof(dist_data[0]),
                              TCA_NETEM_DELAY_DIST,
@@ -464,6 +499,7 @@ static int netem_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
        const struct tc_netem_gimodel *gimodel = NULL;
        const struct tc_netem_gemodel *gemodel = NULL;
        struct tc_netem_qopt qopt;
+       const struct tc_netem_rate *rate = NULL;
        int len = RTA_PAYLOAD(opt) - sizeof(qopt);
        SPRINT_BUF(b1);
 
@@ -505,6 +541,11 @@ static int netem_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
                        if (lb[NETEM_LOSS_GE])
                                gemodel = RTA_DATA(lb[NETEM_LOSS_GE]);
                }                       
+               if (tb[TCA_NETEM_RATE]) {
+                       if (RTA_PAYLOAD(tb[TCA_NETEM_RATE]) < sizeof(*rate))
+                               return -1;
+                       rate = RTA_DATA(tb[TCA_NETEM_RATE]);
+               }
        }
 
        fprintf(f, "limit %d", qopt.limit);
@@ -564,6 +605,16 @@ static int netem_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
                                sprint_percent(corrupt->correlation, b1));
        }
 
+       if (rate && rate->rate) {
+               fprintf(f, " rate %s", sprint_rate(rate->rate, b1));
+               if (rate->packet_overhead)
+                       fprintf(f, " packetoverhead %d", rate->packet_overhead);
+               if (rate->cell_size)
+                       fprintf(f, " cellsize %u", rate->cell_size);
+               if (rate->cell_overhead)
+                       fprintf(f, " celloverhead %d", rate->cell_overhead);
+       }
+
        if (qopt.gap)
                fprintf(f, " gap %lu", (unsigned long)qopt.gap);