tc: q_red: Support 'nodrop' flag

Recognize the new configuration option of the RED Qdisc, "nodrop". Add
support for passing flags through TCA_RED_FLAGS, and use it when passing
TC_RED_NODROP flag.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: David Ahern <dsahern@gmail.com>

diff --git a/man/man8/tc-red.8 b/man/man8/tc-red.8
index dd1ab74c95ee684cfdae8b744b572d4acafe6f3d..b5aaa9866bdad364e0887212aeb574faff20d2b2 100644 (file)
--- a/man/man8/tc-red.8
+++ b/man/man8/tc-red.8
@@ -13,7 +13,7 @@ bytes
 bytes
 .B [ burst
 packets
-.B ] [ ecn ] [ harddrop] [ bandwidth
+.B ] [ ecn ] [ harddrop ] [ nodrop ] [ bandwidth
 rate
 .B ] [ probability
 chance
@@ -123,6 +123,10 @@ If average flow queue size is above
 .B max
 bytes, this parameter forces a drop instead of ecn marking.
 .TP
+nodrop
+With this parameter, traffic that should be marked, but is not ECN-capable, is
+enqueued. Without the parameter it is early-dropped.
+.TP
 adaptive
 (Added in linux-3.3) Sets RED in adaptive mode as described in http://icir.org/floyd/papers/adaptiveRed.pdf
 .nf

diff --git a/tc/q_red.c b/tc/q_red.c
index 6256420fb9a47d2d7f5ad9ac08c4b3a02da276be..53181c82c7bcc949cced34965e236e4cbfc340a3 100644 (file)
--- a/tc/q_red.c
+++ b/tc/q_red.c
@@ -30,12 +30,17 @@ static void explain(void)
        fprintf(stderr,
                "Usage: ... red limit BYTES [min BYTES] [max BYTES] avpkt BYTES [burst PACKETS]\n"
                "               [adaptive] [probability PROBABILITY] [bandwidth KBPS]\n"
-               "               [ecn] [harddrop]\n");
+               "               [ecn] [harddrop] [nodrop]\n");
 }
 
+#define RED_SUPPORTED_FLAGS (TC_RED_HISTORIC_FLAGS | TC_RED_NODROP)
+
 static int red_parse_opt(struct qdisc_util *qu, int argc, char **argv,
                         struct nlmsghdr *n, const char *dev)
 {
+       struct nla_bitfield32 flags_bf = {
+               .selector = RED_SUPPORTED_FLAGS,
+       };
        struct tc_red_qopt opt = {};
        unsigned int burst = 0;
        unsigned int avpkt = 0;
@@ -95,13 +100,15 @@ static int red_parse_opt(struct qdisc_util *qu, int argc, char **argv,
                                return -1;
                        }
                } else if (strcmp(*argv, "ecn") == 0) {
-                       opt.flags |= TC_RED_ECN;
+                       flags_bf.value |= TC_RED_ECN;
                } else if (strcmp(*argv, "harddrop") == 0) {
-                       opt.flags |= TC_RED_HARDDROP;
+                       flags_bf.value |= TC_RED_HARDDROP;
+               } else if (strcmp(*argv, "nodrop") == 0) {
+                       flags_bf.value |= TC_RED_NODROP;
                } else if (strcmp(*argv, "adaptative") == 0) {
-                       opt.flags |= TC_RED_ADAPTATIVE;
+                       flags_bf.value |= TC_RED_ADAPTATIVE;
                } else if (strcmp(*argv, "adaptive") == 0) {
-                       opt.flags |= TC_RED_ADAPTATIVE;
+                       flags_bf.value |= TC_RED_ADAPTATIVE;
                } else if (strcmp(*argv, "help") == 0) {
                        explain();
                        return -1;
@@ -154,6 +161,7 @@ static int red_parse_opt(struct qdisc_util *qu, int argc, char **argv,
        addattr_l(n, 1024, TCA_RED_STAB, sbuf, 256);
        max_P = probability * pow(2, 32);
        addattr_l(n, 1024, TCA_RED_MAX_P, &max_P, sizeof(max_P));
+       addattr_l(n, 1024, TCA_RED_FLAGS, &flags_bf, sizeof(flags_bf));
        addattr_nest_end(n, tail);
        return 0;
 }
@@ -161,6 +169,7 @@ static int red_parse_opt(struct qdisc_util *qu, int argc, char **argv,
 static int red_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
 {
        struct rtattr *tb[TCA_RED_MAX + 1];
+       struct nla_bitfield32 *flags_bf;
        struct tc_red_qopt *qopt;
        __u32 max_P = 0;
 
@@ -183,6 +192,12 @@ static int red_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt)
            RTA_PAYLOAD(tb[TCA_RED_MAX_P]) >= sizeof(__u32))
                max_P = rta_getattr_u32(tb[TCA_RED_MAX_P]);
 
+       if (tb[TCA_RED_FLAGS] &&
+           RTA_PAYLOAD(tb[TCA_RED_FLAGS]) >= sizeof(*flags_bf)) {
+               flags_bf = RTA_DATA(tb[TCA_RED_FLAGS]);
+               qopt->flags = flags_bf->value;
+       }
+
        print_uint(PRINT_JSON, "limit", NULL, qopt->limit);
        print_string(PRINT_FP, NULL, "limit %s ", sprint_size(qopt->limit, b1));
        print_uint(PRINT_JSON, "min", NULL, qopt->qth_min);

diff --git a/tc/tc_red.c b/tc/tc_red.c
index 681ca2971d36bf10e4f5a06838eed39c5db5802d..88f5ff358ce5596cac86790bd9acdd2e4edc278a 100644 (file)
--- a/tc/tc_red.c
+++ b/tc/tc_red.c
@@ -116,4 +116,9 @@ void tc_red_print_flags(__u32 flags)
                print_bool(PRINT_ANY, "adaptive", "adaptive ", true);
        else
                print_bool(PRINT_ANY, "adaptive", NULL, false);
+
+       if (flags & TC_RED_NODROP)
+               print_bool(PRINT_ANY, "nodrop", "nodrop ", true);
+       else
+               print_bool(PRINT_ANY, "nodrop", NULL, false);
 }