Allow default DP of zero in gred

To emulate WRED behaviour, allow default DP of zero.

diff --git a/tc/q_gred.c b/tc/q_gred.c
index 4aaa29b713f14ddcb9cdaa045927154480190bcf..e26840b5401342262e033f3bf9f56ba04f3aec22 100644 (file)
--- a/tc/q_gred.c
+++ b/tc/q_gred.c
@@ -48,39 +48,40 @@ static void explain(void)
 
 #define usage() return(-1)
 
-static int init_gred(struct qdisc_util *qu, int argc, char **argv, struct nlmsghdr *n)
+static int init_gred(struct qdisc_util *qu, int argc, char **argv, 
+                    struct nlmsghdr *n)
 {
 
        struct rtattr *tail;
        struct tc_gred_sopt opt;
-       memset(&opt, 0, sizeof(struct tc_gred_sopt));
+       int dps = 0;
+       int def_dp = -1;
 
        while (argc > 0) {
                DPRINTF(stderr,"init_gred: invoked with %s\n",*argv);
                if (strcmp(*argv, "DPs") == 0) {
                        NEXT_ARG();
                        DPRINTF(stderr,"init_gred: next_arg with %s\n",*argv);
-                       opt.DPs=strtol(*argv, (char **)NULL, 10);
-                       if (opt.DPs >MAX_DPs) { /* need a better error check */
-                               fprintf(stderr, "DPs =%u \n",opt.DPs);
+                       dps = strtol(*argv, (char **)NULL, 10);
+                       if (dps < 0 || dps >MAX_DPs) {
+                               fprintf(stderr, "DPs =%d\n", dps);
                                fprintf(stderr, "Illegal \"DPs\"\n");
                                fprintf(stderr, "GRED: only %d DPs are "
-                                   "currently supported\n",MAX_DPs);
+                                       "currently supported\n",MAX_DPs);
                                return -1;
                        }
                } else if (strcmp(*argv, "default") == 0) {
                        NEXT_ARG();
-                       opt.def_DP=strtol(*argv, (char **)NULL, 10);
-                       if (!opt.DPs) {
+                       def_dp = strtol(*argv, (char **)NULL, 10);
+                       if (dps) {
                                fprintf(stderr, "\"default DP\" must be "
-                                   "defined after DPs\n");
+                                       "defined after DPs\n");
                                return -1;
                        }
-                       if (opt.def_DP>opt.DPs) {
-/*
-                               fprintf(stderr, "\"default DP\" must be less than %d\nNote: DP runs from 0 to %d for %d DPs\n",opt.DPs,opt.DPs-1,opt.DPs);
-*/
-                               fprintf(stderr, "\"default DP\" must be less than %d\n",opt.DPs);
+                       if (def_dp < 0 || def_dp > dps) {
+                               fprintf(stderr, 
+                                       "\"default DP\" must be less than %d\n",
+                                       opt.DPs);
                                return -1;
                        }
                } else if (strcmp(*argv, "grio") == 0) {
@@ -94,20 +95,24 @@ static int init_gred(struct qdisc_util *qu, int argc, char **argv, struct nlmsgh
                        return -1;
                }
                argc--; argv++;
-}
+       }
 
-if ((!opt.DPs) || (!opt.def_DP))
-{
-       fprintf(stderr, "Illegal gred setup parameters \n");
-                       return -1;
-}
-DPRINTF("TC_GRED: sending DPs=%d default=%d\n",opt.DPs,opt.def_DP);
+       if (!dps || def_dp == -1) {
+               fprintf(stderr, "Illegal gred setup parameters \n");
+               return -1;
+       }
+
+       memset(&opt, 0, sizeof(struct tc_gred_sopt));
+       opt.DPs = dps;
+       opt.def_DP = def_dp;
+
+       DPRINTF("TC_GRED: sending DPs=%d default=%d\n",opt.DPs,opt.def_DP);
        n->nlmsg_flags|=NLM_F_CREATE;
        tail = NLMSG_TAIL(n);
        addattr_l(n, 1024, TCA_OPTIONS, NULL, 0);
        addattr_l(n, 1024, TCA_GRED_DPS, &opt, sizeof(struct tc_gred_sopt));
        tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
-return 0;
+       return 0;
 }
 /*
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^