CHOKe scheduler
TC commands for CHOKe qdisc
diff --git a/tc/q_choke.c b/tc/q_choke.c
new file mode 100644
index 0000000..6e54cb7
--- /dev/null
+++ b/tc/q_choke.c
@@ -0,0 +1,215 @@
+/*
+ * q_choke.c CHOKE.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * Authors: Stephen Hemminger <shemminger@vyatta.com>
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <syslog.h>
+#include <fcntl.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <string.h>
+
+#include "utils.h"
+#include "tc_util.h"
+
+#include "tc_red.h"
+
+static void explain(void)
+{
+ fprintf(stderr, "Usage: ... choke limit PACKETS bandwidth KBPS [ecn]\n");
+ fprintf(stderr, " [ min PACKETS ] [ max PACKETS ] [ burst PACKETS ]\n");
+}
+
+static int choke_parse_opt(struct qdisc_util *qu, int argc, char **argv,
+ struct nlmsghdr *n)
+{
+ struct tc_red_qopt opt;
+ unsigned burst = 0;
+ unsigned avpkt = 1000;
+ double probability = 0.02;
+ unsigned rate = 0;
+ int ecn_ok = 0;
+ int wlog;
+ __u8 sbuf[256];
+ struct rtattr *tail;
+
+ memset(&opt, 0, sizeof(opt));
+
+ while (argc > 0) {
+ if (strcmp(*argv, "limit") == 0) {
+ NEXT_ARG();
+ if (get_unsigned(&opt.limit, *argv, 0)) {
+ fprintf(stderr, "Illegal \"limit\"\n");
+ return -1;
+ }
+ } else if (strcmp(*argv, "bandwidth") == 0) {
+ NEXT_ARG();
+ if (get_rate(&rate, *argv)) {
+ fprintf(stderr, "Illegal \"bandwidth\"\n");
+ return -1;
+ }
+ } else if (strcmp(*argv, "ecn") == 0) {
+ ecn_ok = 1;
+ } else if (strcmp(*argv, "min") == 0) {
+ NEXT_ARG();
+ if (get_unsigned(&opt.qth_min, *argv, 0)) {
+ fprintf(stderr, "Illegal \"min\"\n");
+ return -1;
+ }
+ } else if (strcmp(*argv, "max") == 0) {
+ NEXT_ARG();
+ if (get_unsigned(&opt.qth_max, *argv, 0)) {
+ fprintf(stderr, "Illegal \"max\"\n");
+ return -1;
+ }
+ } else if (strcmp(*argv, "burst") == 0) {
+ NEXT_ARG();
+ if (get_unsigned(&burst, *argv, 0)) {
+ fprintf(stderr, "Illegal \"burst\"\n");
+ return -1;
+ }
+ } else if (strcmp(*argv, "avpkt") == 0) {
+ NEXT_ARG();
+ if (get_size(&avpkt, *argv)) {
+ fprintf(stderr, "Illegal \"avpkt\"\n");
+ return -1;
+ }
+ } else if (strcmp(*argv, "probability") == 0) {
+ NEXT_ARG();
+ if (sscanf(*argv, "%lg", &probability) != 1) {
+ fprintf(stderr, "Illegal \"probability\"\n");
+ return -1;
+ }
+ } else if (strcmp(*argv, "help") == 0) {
+ explain();
+ return -1;
+ } else {
+ fprintf(stderr, "What is \"%s\"?\n", *argv);
+ explain();
+ return -1;
+ }
+ argc--; argv++;
+ }
+
+ if (!rate || !opt.limit) {
+ fprintf(stderr, "Required parameter (bandwidth, limit) is missing\n");
+ return -1;
+ }
+
+ /* Compute default min/max thresholds based on
+ Sally Floyd's recommendations:
+ http://www.icir.org/floyd/REDparameters.txt
+ */
+ if (!opt.qth_max)
+ opt.qth_max = opt.limit / 4;
+ if (!opt.qth_min)
+ opt.qth_min = opt.qth_max / 3;
+ if (!burst)
+ burst = (2 * opt.qth_min + opt.qth_max) / 3;
+
+ if (opt.qth_max > opt.limit) {
+ fprintf(stderr, "\"max\" is larger than \"limit\"\n");
+ return -1;
+ }
+
+ if (opt.qth_min > opt.qth_min) {
+ fprintf(stderr, "\"min\" is not smaller than \"max\"\n");
+ return -1;
+ }
+
+ wlog = tc_red_eval_ewma(opt.qth_min*avpkt, burst, avpkt);
+ if (wlog < 0) {
+ fprintf(stderr, "CHOKE: failed to calculate EWMA constant.\n");
+ return -1;
+ }
+ if (wlog >= 10)
+ fprintf(stderr, "CHOKE: WARNING. Burst %d seems to be to large.\n", burst);
+ opt.Wlog = wlog;
+
+ wlog = tc_red_eval_P(opt.qth_min*avpkt, opt.qth_max*avpkt, probability);
+ if (wlog < 0) {
+ fprintf(stderr, "CHOKE: failed to calculate probability.\n");
+ return -1;
+ }
+ opt.Plog = wlog;
+
+ wlog = tc_red_eval_idle_damping(opt.Wlog, avpkt, rate, sbuf);
+ if (wlog < 0) {
+ fprintf(stderr, "CHOKE: failed to calculate idle damping table.\n");
+ return -1;
+ }
+ opt.Scell_log = wlog;
+ if (ecn_ok)
+ opt.flags |= TC_RED_ECN;
+
+ tail = NLMSG_TAIL(n);
+ addattr_l(n, 1024, TCA_OPTIONS, NULL, 0);
+ addattr_l(n, 1024, TCA_CHOKE_PARMS, &opt, sizeof(opt));
+ addattr_l(n, 1024, TCA_CHOKE_STAB, sbuf, 256);
+ tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
+ return 0;
+}
+
+static int choke_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
+{
+ struct rtattr *tb[TCA_CHOKE_STAB+1];
+ const struct tc_red_qopt *qopt;
+
+ if (opt == NULL)
+ return 0;
+
+ parse_rtattr_nested(tb, TCA_CHOKE_STAB, opt);
+
+ if (tb[TCA_CHOKE_PARMS] == NULL)
+ return -1;
+ qopt = RTA_DATA(tb[TCA_CHOKE_PARMS]);
+ if (RTA_PAYLOAD(tb[TCA_CHOKE_PARMS]) < sizeof(*qopt))
+ return -1;
+
+ fprintf(f, "limit %up min %up max %up ",
+ qopt->limit, qopt->qth_min, qopt->qth_max);
+
+ if (qopt->flags & TC_RED_ECN)
+ fprintf(f, "ecn ");
+
+ if (show_details) {
+ fprintf(f, "ewma %u Plog %u Scell_log %u",
+ qopt->Wlog, qopt->Plog, qopt->Scell_log);
+ }
+ return 0;
+}
+
+static int choke_print_xstats(struct qdisc_util *qu, FILE *f,
+ struct rtattr *xstats)
+{
+ struct tc_choke_xstats *st;
+
+ if (xstats == NULL)
+ return 0;
+
+ if (RTA_PAYLOAD(xstats) < sizeof(*st))
+ return -1;
+
+ st = RTA_DATA(xstats);
+ fprintf(f, " marked %u early %u pdrop %u other %u matched %u",
+ st->marked, st->early, st->pdrop, st->other, st->matched);
+ return 0;
+
+}
+
+struct qdisc_util choke_qdisc_util = {
+ .id = "choke",
+ .parse_qopt = choke_parse_opt,
+ .print_qopt = choke_print_opt,
+ .print_xstats = choke_print_xstats,
+};