selftests: net: test IPV6_FL_A_RENEW

RENEW was the only flow label action without selftests coverage.

Assert renew returns no error on correct usage and fails for labels
that do not exist.

This test is based on the previously implemented EXCL share test,
which demonstrates that a new flow label with the same value can be
created after the linger period. Renew is used here to show that a
flow label can last longer and block a new flow label creation after
the previous linger time. This test, however, demands sleep during
execution, and should be placed as a conditional test under the -l
option.

The addition of the expect_fail_errno helper is necessary to assert
the corresponding error when a function can fail in multiple ways.

Signed-off-by: Marcelo Mendes Spessoto Junior <marcelomspessoto@gmail.com>
Link: https://patch.msgid.link/20260807220942.421382-2-marcelomspessoto@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 57 insertions, 1 deletions

diff --git a/tools/testing/selftests/net/ipv6_flowlabel_mgr.c b/tools/testing/selftests/net/ipv6_flowlabel_mgr.c
index af95b48acea9..ec187890a1ed 100644
--- a/tools/testing/selftests/net/ipv6_flowlabel_mgr.c
+++ b/tools/testing/selftests/net/ipv6_flowlabel_mgr.c
@@ -42,6 +42,23 @@
 #define expect_pass(x)	__expect(x)
 #define expect_fail(x)	__expect(!(x))
 
+#define expect_fail_errno(x, e)						\
+	do {								\
+		int __exp = (e);					\
+		int __ret = (x);					\
+		int __err = errno;					\
+		if (__ret && __err == __exp)				\
+			fprintf(stderr, "[OK]   " #x "\n");		\
+		else if (!__ret)					\
+			error(1, 0, "[ERR]  " #x			\
+			      " (line %d): unexpectedly succeeded",	\
+			      __LINE__);				\
+		else							\
+			error(1, 0, "[ERR]  " #x			\
+			      " (line %d): expected errno %d, got %d",	\
+			      __LINE__, __exp, __err);			\
+	} while (0)
+
 static bool cfg_long_running;
 static bool cfg_verbose;
 
@@ -71,6 +88,19 @@ static int flowlabel_put(int fd, uint32_t label)
 	return setsockopt(fd, SOL_IPV6, IPV6_FLOWLABEL_MGR, &req, sizeof(req));
 }
 
+static int flowlabel_renew(int fd, uint32_t label, uint8_t share,
+			   uint16_t linger)
+{
+	struct in6_flowlabel_req req = {
+		.flr_action = IPV6_FL_A_RENEW,
+		.flr_label = htonl(label),
+		.flr_share = share,
+		.flr_linger = linger,
+	};
+
+	return setsockopt(fd, SOL_IPV6, IPV6_FLOWLABEL_MGR, &req, sizeof(req));
+}
+
 static void run_tests(int fd)
 {
 	int wstatus;
@@ -94,7 +124,7 @@ static void run_tests(int fd)
 	expect_pass(flowlabel_get(fd, 1, IPV6_FL_S_ANY, IPV6_FL_F_CREATE));
 	explain("cannot get it again with the exclusive (FL_FL_EXCL) flag");
 	expect_fail(flowlabel_get(fd, 1, IPV6_FL_S_ANY,
-					 IPV6_FL_F_CREATE | IPV6_FL_F_EXCL));
+				  IPV6_FL_F_CREATE | IPV6_FL_F_EXCL));
 	explain("can now put exactly three references");
 	expect_pass(flowlabel_put(fd, 1));
 	expect_pass(flowlabel_put(fd, 1));
@@ -160,6 +190,32 @@ static void run_tests(int fd)
 		error(1, errno, "wait");
 	if (!WIFEXITED(wstatus) || WEXITSTATUS(wstatus) != 0)
 		error(1, errno, "wait: unexpected child result");
+
+	explain("It is not possible to renew a label that does not exist");
+	expect_fail_errno(flowlabel_renew(fd, 5, IPV6_FL_S_EXCL,
+					  2 * (FL_MIN_LINGER * 2 + 1)),
+			  ESRCH);
+
+	explain("Create a label for basic renew validation");
+	expect_pass(flowlabel_get(fd, 5, IPV6_FL_S_EXCL, IPV6_FL_F_CREATE));
+	explain("renew does not error for an existing, valid label");
+	expect_pass(flowlabel_renew(fd, 5, IPV6_FL_S_EXCL,
+				    2 * (FL_MIN_LINGER * 2 + 1)));
+
+	if (cfg_long_running) {
+		explain("create a new label with FL_MIN_LINGER linger time");
+		expect_pass(flowlabel_get(fd, 6, IPV6_FL_S_EXCL,
+					  IPV6_FL_F_CREATE));
+		explain("renew the label to extend linger, then put it");
+		expect_pass(flowlabel_renew(fd, 6, IPV6_FL_S_EXCL,
+					    2 * (FL_MIN_LINGER * 2 + 1)));
+		expect_pass(flowlabel_put(fd, 6));
+		sleep(FL_MIN_LINGER * 2 + 1);
+		explain("cannot create: new linger time not over yet");
+		expect_fail_errno(flowlabel_get(fd, 6, IPV6_FL_S_ANY,
+						IPV6_FL_F_CREATE),
+				  EPERM);
+	}
 }
 
 static void parse_opts(int argc, char **argv)