Suggested code test scenarios where listen(2) call without explicit bind(2) is allowed and forbidden. Signed-off-by: Ivanov Mikhail <ivanov.mikhail1@xxxxxxxxxxxxxxxxxxx> Reviewed-by: Konstantin Meskhidze <konstantin.meskhidze@xxxxxxxxxx> --- tools/testing/selftests/landlock/net_test.c | 89 +++++++++++++++++++++ 1 file changed, 89 insertions(+) diff --git a/tools/testing/selftests/landlock/net_test.c b/tools/testing/selftests/landlock/net_test.c index 936cfc879f1d..6d6b5aef387f 100644 --- a/tools/testing/selftests/landlock/net_test.c +++ b/tools/testing/selftests/landlock/net_test.c @@ -1714,6 +1714,95 @@ TEST_F(port_specific, bind_connect_zero) EXPECT_EQ(0, close(bind_fd)); } +TEST_F(port_specific, listen_zero) +{ + int listen_fd, connect_fd; + uint16_t port; + + /* Adds a rule layer with bind actions. */ + if (variant->sandbox == TCP_SANDBOX) { + const struct landlock_ruleset_attr ruleset_attr = { + .handled_access_net = LANDLOCK_ACCESS_NET_BIND_TCP, + }; + const struct landlock_net_port_attr tcp_bind_zero = { + .allowed_access = LANDLOCK_ACCESS_NET_BIND_TCP, + .port = 0, + }; + int ruleset_fd; + + ruleset_fd = landlock_create_ruleset(&ruleset_attr, + sizeof(ruleset_attr), 0); + ASSERT_LE(0, ruleset_fd); + + /* Checks zero port value on bind action. */ + EXPECT_EQ(0, + landlock_add_rule(ruleset_fd, LANDLOCK_RULE_NET_PORT, + &tcp_bind_zero, 0)); + + enforce_ruleset(_metadata, ruleset_fd); + EXPECT_EQ(0, close(ruleset_fd)); + } + + listen_fd = socket_variant(&self->srv0); + ASSERT_LE(0, listen_fd); + + connect_fd = socket_variant(&self->srv0); + ASSERT_LE(0, listen_fd); + /* + * Allow listen(2) to select a random port for the socket, + * since bind(2) wasn't called. + */ + EXPECT_EQ(0, listen(listen_fd, backlog)); + + /* Sets binded (by listen(2)) port for both protocol families. */ + port = get_binded_port(listen_fd, &variant->prot); + EXPECT_NE(0, port); + set_port(&self->srv0, port); + + /* Connects on the binded port. */ + EXPECT_EQ(0, connect_variant(connect_fd, &self->srv0)); + + EXPECT_EQ(0, close(listen_fd)); + EXPECT_EQ(0, close(connect_fd)); +} + +TEST_F(port_specific, deny_listen_zero) +{ + int listen_fd, ret; + + /* Adds a rule layer with bind actions. */ + if (variant->sandbox == TCP_SANDBOX) { + const struct landlock_ruleset_attr ruleset_attr = { + .handled_access_net = LANDLOCK_ACCESS_NET_BIND_TCP, + }; + int ruleset_fd; + + ruleset_fd = landlock_create_ruleset(&ruleset_attr, + sizeof(ruleset_attr), 0); + ASSERT_LE(0, ruleset_fd); + + /* Forbid binding to any port. */ + enforce_ruleset(_metadata, ruleset_fd); + EXPECT_EQ(0, close(ruleset_fd)); + } + + listen_fd = socket_variant(&self->srv0); + ASSERT_LE(0, listen_fd); + /* + * Check that listen(2) call is prohibited without first calling bind(2). + */ + ret = listen(listen_fd, backlog); + if (is_restricted(&variant->prot, variant->sandbox)) { + /* Denied by Landlock. */ + EXPECT_NE(0, ret); + EXPECT_EQ(EACCES, errno); + } else { + EXPECT_EQ(0, ret); + } + + EXPECT_EQ(0, close(listen_fd)); +} + TEST_F(port_specific, bind_connect_1023) { int bind_fd, connect_fd, ret; -- 2.34.1