[PATCH iproute2-next 2/2] tc: add new attr TCA_EXT_WARN_MSG

[Hangbin Liu <liuhangbin@gmail.com>]

Currently, when the rule is not to be exclusively executed by the
hardware, extack is not passed along and offloading failures don't
get logged. Add a new attr TCA_EXT_WARN_MSG to log the extack message
so we can monitor the HW failures. e.g.

  # tc monitor
  added chain dev enp3s0f1np1 parent ffff: chain 0
  added filter dev enp3s0f1np1 ingress protocol all pref 49152 flower chain 0 handle 0x1
    ct_state +trk+new
    not_in_hw
          action order 1: gact action drop
           random type none pass val 0
           index 1 ref 1 bind 1

  Warning: mlx5_core: matching on ct_state +new isn't supported.

Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
---
 include/uapi/linux/rtnetlink.h | 1 +
 tc/m_action.c                  | 6 ++++++
 tc/tc_filter.c                 | 5 +++++
 tc/tc_qdisc.c                  | 6 ++++++
 4 files changed, 18 insertions(+)

diff --git a/include/uapi/linux/rtnetlink.h b/include/uapi/linux/rtnetlink.h
index f4a540c0..217b25b9 100644
--- a/include/uapi/linux/rtnetlink.h
+++ b/include/uapi/linux/rtnetlink.h
@@ -635,6 +635,7 @@ enum {
 	TCA_INGRESS_BLOCK,
 	TCA_EGRESS_BLOCK,
 	TCA_DUMP_FLAGS,
+	TCA_EXT_WARN_MSG,
 	__TCA_MAX
 };
 
diff --git a/tc/m_action.c b/tc/m_action.c
index b3fd0193..7121c2fb 100644
--- a/tc/m_action.c
+++ b/tc/m_action.c
@@ -590,6 +590,12 @@ int print_action(struct nlmsghdr *n, void *arg)
 
 	open_json_object(NULL);
 	tc_dump_action(fp, tb[TCA_ACT_TAB], tot_acts ? *tot_acts:0, false);
+
+	if (tb[TCA_EXT_WARN_MSG]) {
+		print_string(PRINT_ANY, "Warn", "%s ", rta_getattr_str(tb[TCA_EXT_WARN_MSG]));
+		print_nl();
+	}
+
 	close_json_object();
 
 	return 0;
diff --git a/tc/tc_filter.c b/tc/tc_filter.c
index 71be2e81..dac74f58 100644
--- a/tc/tc_filter.c
+++ b/tc/tc_filter.c
@@ -371,6 +371,11 @@ int print_filter(struct nlmsghdr *n, void *arg)
 		print_nl();
 	}
 
+	if (tb[TCA_EXT_WARN_MSG]) {
+		print_string(PRINT_ANY, "Warn", "%s ", rta_getattr_str(tb[TCA_EXT_WARN_MSG]));
+		print_nl();
+	}
+
 	close_json_object();
 	fflush(fp);
 	return 0;
diff --git a/tc/tc_qdisc.c b/tc/tc_qdisc.c
index 33a6665e..a84602b4 100644
--- a/tc/tc_qdisc.c
+++ b/tc/tc_qdisc.c
@@ -346,6 +346,12 @@ int print_qdisc(struct nlmsghdr *n, void *arg)
 			print_nl();
 		}
 	}
+
+	if (tb[TCA_EXT_WARN_MSG]) {
+		print_string(PRINT_ANY, "Warn", "%s ", rta_getattr_str(tb[TCA_EXT_WARN_MSG]));
+		print_nl();
+	}
+
 	close_json_object();
 	fflush(fp);
 	return 0;
-- 
2.38.1