iproute2: add support for invisible qdisc dumping

Support the new TCA_DUMP_INVISIBLE netlink attribute that allows asking
kernel to perform 'full qdisc dump', as for historical reasons some of the
default qdiscs are being hidden by the kernel.

The command syntax is being extended by voluntary 'invisible' argument to
'tc qdisc show'.

Signed-off-by: Jiri Kosina <jkosina@suse.cz>

1 files changed, 23 insertions, 2 deletions

diff --git a/tc/tc_qdisc.c b/tc/tc_qdisc.c
index 3a3701c2..1e9d9097 100644
--- a/tc/tc_qdisc.c
+++ b/tc/tc_qdisc.c
@@ -34,7 +34,7 @@ static int usage(void)
 	fprintf(stderr, "       [ stab [ help | STAB_OPTIONS] ]\n");
 	fprintf(stderr, "       [ [ QDISC_KIND ] [ help | OPTIONS ] ]\n");
 	fprintf(stderr, "\n");
-	fprintf(stderr, "       tc qdisc show [ dev STRING ] [ ingress | clsact ]\n");
+	fprintf(stderr, "       tc qdisc show [ dev STRING ] [ ingress | clsact ] [ invisible ]\n");
 	fprintf(stderr, "Where:\n");
 	fprintf(stderr, "QDISC_KIND := { [p|b]fifo | tbf | prio | cbq | red | etc. }\n");
 	fprintf(stderr, "OPTIONS := ... try tc qdisc add <desired QDISC_KIND> help\n");
@@ -292,6 +292,7 @@ static int tc_qdisc_list(int argc, char **argv)
 {
 	struct tcmsg t = { .tcm_family = AF_UNSPEC };
 	char d[16] = {};
+	bool dump_invisible = false;
 
 	while (argc > 0) {
 		if (strcmp(*argv, "dev") == 0) {
@@ -306,6 +307,8 @@ static int tc_qdisc_list(int argc, char **argv)
 			t.tcm_parent = TC_H_INGRESS;
 		} else if (matches(*argv, "help") == 0) {
 			usage();
+		} else if (strcmp(*argv, "invisible") == 0) {
+			dump_invisible = true;
 		} else {
 			fprintf(stderr, "What is \"%s\"? Try \"tc qdisc help\".\n", *argv);
 			return -1;
@@ -325,7 +328,25 @@ static int tc_qdisc_list(int argc, char **argv)
 		filter_ifindex = t.tcm_ifindex;
 	}
 
-	if (rtnl_dump_request(&rth, RTM_GETQDISC, &t, sizeof(t)) < 0) {
+	if (dump_invisible) {
+		struct {
+			struct nlmsghdr n;
+			struct tcmsg t;
+			char buf[256];
+		} req = {
+			.n.nlmsg_type = RTM_GETQDISC,
+			.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg)),
+		};
+
+		req.t.tcm_family = AF_UNSPEC;
+
+		addattr(&req.n, 256, TCA_DUMP_INVISIBLE);
+		if (rtnl_dump_request_n(&rth, &req.n) < 0) {
+			perror("Cannot send dump request");
+			return 1;
+		}
+
+	} else if (rtnl_dump_request(&rth, RTM_GETQDISC, &t, sizeof(t)) < 0) {
 		perror("Cannot send dump request");
 		return 1;
 	}