tc/taprio: don't print netlink attributes which weren't reported by the kernel

When an admin schedule is pending and hasn't yet become operational, the
kernel will report only the parameters of the admin schedule in a nested
TCA_TAPRIO_ATTR_ADMIN_SCHED attribute.

However, we default to printing zeroes even for the parameters of the
operational base time, when that doesn't exist.

Fixes: 0dd16449356f ("tc: Add support for configuring the taprio scheduler")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Acked-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>

diff --git a/tc/q_taprio.c b/tc/q_taprio.c
index 913197f68caa46281d48d49c27f1db65d6790adf..6250871fb5f2604e83873d1ed0497b0b946d9da0 100644 (file)
--- a/tc/q_taprio.c
+++ b/tc/q_taprio.c
@@ -416,14 +416,11 @@ static int taprio_parse_opt(struct qdisc_util *qu, int argc,
        return 0;
 }
 
-static int print_sched_list(FILE *f, struct rtattr *list)
+static void print_sched_list(FILE *f, struct rtattr *list)
 {
-       struct rtattr *item;
+       struct rtattr *item, *nla;
        int rem;
 
-       if (list == NULL)
-               return 0;
-
        rem = RTA_PAYLOAD(list);
 
        open_json_array(PRINT_JSON, "schedule");
@@ -432,60 +429,82 @@ static int print_sched_list(FILE *f, struct rtattr *list)
 
        for (item = RTA_DATA(list); RTA_OK(item, rem); item = RTA_NEXT(item, rem)) {
                struct rtattr *tb[TCA_TAPRIO_SCHED_ENTRY_MAX + 1];
-               __u32 index = 0, gatemask = 0, interval = 0;
-               __u8 command = 0;
 
                parse_rtattr_nested(tb, TCA_TAPRIO_SCHED_ENTRY_MAX, item);
 
-               if (tb[TCA_TAPRIO_SCHED_ENTRY_INDEX])
-                       index = rta_getattr_u32(tb[TCA_TAPRIO_SCHED_ENTRY_INDEX]);
+               open_json_object(NULL);
 
-               if (tb[TCA_TAPRIO_SCHED_ENTRY_CMD])
-                       command = rta_getattr_u8(tb[TCA_TAPRIO_SCHED_ENTRY_CMD]);
+               nla = tb[TCA_TAPRIO_SCHED_ENTRY_INDEX];
+               if (nla) {
+                       __u32 index = rta_getattr_u32(nla);
 
-               if (tb[TCA_TAPRIO_SCHED_ENTRY_GATE_MASK])
-                       gatemask = rta_getattr_u32(tb[TCA_TAPRIO_SCHED_ENTRY_GATE_MASK]);
+                       print_uint(PRINT_ANY, "index", "\tindex %u", index);
+               }
 
-               if (tb[TCA_TAPRIO_SCHED_ENTRY_INTERVAL])
-                       interval = rta_getattr_u32(tb[TCA_TAPRIO_SCHED_ENTRY_INTERVAL]);
+               nla = tb[TCA_TAPRIO_SCHED_ENTRY_CMD];
+               if (nla) {
+                       __u8 command = rta_getattr_u8(nla);
+
+                       print_string(PRINT_ANY, "cmd", " cmd %s",
+                                    entry_cmd_to_str(command));
+               }
+
+               nla = tb[TCA_TAPRIO_SCHED_ENTRY_GATE_MASK];
+               if (nla) {
+                       __u32 gatemask = rta_getattr_u32(nla);
+
+                       print_0xhex(PRINT_ANY, "gatemask", " gatemask %#llx",
+                                   gatemask);
+               }
+
+               nla = tb[TCA_TAPRIO_SCHED_ENTRY_INTERVAL];
+               if (nla) {
+                       __u32 interval = rta_getattr_u32(nla);
+
+                       print_uint(PRINT_ANY, "interval", " interval %u",
+                                  interval);
+               }
 
-               open_json_object(NULL);
-               print_uint(PRINT_ANY, "index", "\tindex %u", index);
-               print_string(PRINT_ANY, "cmd", " cmd %s", entry_cmd_to_str(command));
-               print_0xhex(PRINT_ANY, "gatemask", " gatemask %#llx", gatemask);
-               print_uint(PRINT_ANY, "interval", " interval %u", interval);
                close_json_object();
 
                print_nl();
        }
 
        close_json_array(PRINT_ANY, "");
-
-       return 0;
 }
 
 static int print_schedule(FILE *f, struct rtattr **tb)
 {
-       int64_t base_time = 0, cycle_time = 0, cycle_time_extension = 0;
+       struct rtattr *nla;
 
-       if (tb[TCA_TAPRIO_ATTR_SCHED_BASE_TIME])
-               base_time = rta_getattr_s64(tb[TCA_TAPRIO_ATTR_SCHED_BASE_TIME]);
+       nla = tb[TCA_TAPRIO_ATTR_SCHED_BASE_TIME];
+       if (nla) {
+               int64_t base_time = rta_getattr_s64(nla);
 
-       if (tb[TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME])
-               cycle_time = rta_getattr_s64(tb[TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME]);
+               print_lluint(PRINT_ANY, "base_time", "\tbase-time %lld",
+                            base_time);
+       }
 
-       if (tb[TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME_EXTENSION])
-               cycle_time_extension = rta_getattr_s64(
-                       tb[TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME_EXTENSION]);
+       nla = tb[TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME];
+       if (nla) {
+               int64_t cycle_time = rta_getattr_s64(nla);
 
-       print_lluint(PRINT_ANY, "base_time", "\tbase-time %lld", base_time);
+               print_lluint(PRINT_ANY, "cycle_time", " cycle-time %lld",
+                            cycle_time);
+       }
 
-       print_lluint(PRINT_ANY, "cycle_time", " cycle-time %lld", cycle_time);
+       nla = tb[TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME_EXTENSION];
+       if (nla) {
+               int64_t cycle_time_extension = rta_getattr_s64(nla);
 
-       print_lluint(PRINT_ANY, "cycle_time_extension",
-                    " cycle-time-extension %lld", cycle_time_extension);
+               print_lluint(PRINT_ANY, "cycle_time_extension",
+                            " cycle-time-extension %lld",
+                            cycle_time_extension);
+       }
 
-       print_sched_list(f, tb[TCA_TAPRIO_ATTR_SCHED_ENTRY_LIST]);
+       nla = tb[TCA_TAPRIO_ATTR_SCHED_ENTRY_LIST];
+       if (nla)
+               print_sched_list(f, nla);
 
        return 0;
 }