Filter class output by classid

Sometimes while dividing bandwidth by classes it is useful to see how some
specific class doing things live.

Which my simple patch it is possible to do
watch -n1 "tc -s -d class show dev eth0.2022 classid 1:1520"
and to get live statistics, how packets queued or dropped, and how much
bandwidth used (if estimator defined) for specific class.

Signed-off-by: Denys Fedoryshchenko <denys@visp.net.lb>

diff --git a/tc/tc_class.c b/tc/tc_class.c
index 774497aae68da3fb171dd5828fa68f88a4fbf719..9d4eea5c1c8f297c3f553091bbf12d05f21115e7 100644 (file)
--- a/tc/tc_class.c
+++ b/tc/tc_class.c
@@ -146,6 +146,7 @@ int tc_class_modify(int cmd, unsigned flags, int argc, char **argv)
 
 int filter_ifindex;
 __u32 filter_qdisc;
+__u32 filter_classid;
 
 int print_class(const struct sockaddr_nl *who,
                       struct nlmsghdr *n, void *arg)
@@ -169,6 +170,9 @@ int print_class(const struct sockaddr_nl *who,
        if (filter_qdisc && TC_H_MAJ(t->tcm_handle^filter_qdisc))
                return 0;
 
+       if (filter_classid && t->tcm_handle != filter_classid)
+               return 0;
+
        memset(tb, 0, sizeof(tb));
        parse_rtattr(tb, TCA_MAX, TCA_RTA(t), len);
 
@@ -249,6 +253,12 @@ int tc_class_list(int argc, char **argv)
                                duparg("qdisc", *argv);
                        if (get_qdisc_handle(&filter_qdisc, *argv))
                                invarg(*argv, "invalid qdisc ID");
+               } else if (strcmp(*argv, "classid") == 0) {
+                       NEXT_ARG();
+                       if (filter_classid)
+                               duparg("classid", *argv);
+                       if (get_tc_classid(&filter_classid, *argv))
+                               invarg(*argv, "invalid class ID");
                } else if (strcmp(*argv, "root") == 0) {
                        if (t.tcm_parent) {
                                fprintf(stderr, "Error: \"root\" is duplicate parent ID\n");