[PATCH v11 5/8] selftests/landlock: Test connected vs non-connected datagram UNIX socket
From: Tahera Fahimi <hidden>
Date: 2024-09-05 00:14:27
Also in:
linux-security-module, lkml
Subsystem:
kernel selftest framework, landlock security module, the rest · Maintainers:
Shuah Khan, Mickaël Salaün, Linus Torvalds
This patch checks the specific case where a scoped datagram socket is connected and send(2) works, whereas sendto(2) is denied if the datagram socket is not connected. Signed-off-by: Tahera Fahimi <redacted> --- .../landlock/scoped_abstract_unix_test.c | 105 ++++++++++++++++++ 1 file changed, 105 insertions(+)
diff --git a/tools/testing/selftests/landlock/scoped_abstract_unix_test.c b/tools/testing/selftests/landlock/scoped_abstract_unix_test.c
index 8fc47e45d17e..39297ebf7b73 100644
--- a/tools/testing/selftests/landlock/scoped_abstract_unix_test.c
+++ b/tools/testing/selftests/landlock/scoped_abstract_unix_test.c@@ -819,4 +819,109 @@ TEST_F(various_address_sockets, scoped_pathname_sockets) _metadata->exit_code = KSFT_FAIL; } +TEST(datagram_sockets) +{ + struct service_fixture connected_addr, non_connected_addr; + int conn_sock, non_conn_sock; + int pipe_parent[2], pipe_child[2]; + int status; + char buf; + pid_t child; + int num_bytes; + char data[64]; + + drop_caps(_metadata); + memset(&connected_addr, 0, sizeof(connected_addr)); + set_unix_address(&connected_addr, 0); + memset(&non_connected_addr, 0, sizeof(non_connected_addr)); + set_unix_address(&non_connected_addr, 1); + + ASSERT_EQ(0, pipe2(pipe_parent, O_CLOEXEC)); + ASSERT_EQ(0, pipe2(pipe_child, O_CLOEXEC)); + + child = fork(); + ASSERT_LE(0, child); + if (child == 0) { + char buf_data[64]; + + ASSERT_EQ(0, close(pipe_parent[1])); + ASSERT_EQ(0, close(pipe_child[0])); + + conn_sock = socket(AF_UNIX, SOCK_DGRAM, 0); + non_conn_sock = socket(AF_UNIX, SOCK_DGRAM, 0); + ASSERT_NE(-1, conn_sock); + ASSERT_NE(-1, non_conn_sock); + + ASSERT_EQ(1, read(pipe_parent[0], &buf, 1)); + + ASSERT_EQ(0, connect(conn_sock, &connected_addr.unix_addr, + connected_addr.unix_addr_len)); + + /* Both connected and non-connected sockets can send + * data when the domain is not scoped. + */ + memset(buf_data, 'x', sizeof(buf_data)); + ASSERT_NE(-1, send(conn_sock, buf_data, sizeof(buf_data), 0)); + ASSERT_NE(-1, sendto(non_conn_sock, buf_data, sizeof(buf_data), + 0, &non_connected_addr.unix_addr, + non_connected_addr.unix_addr_len)); + ASSERT_EQ(1, write(pipe_child[1], ".", 1)); + + /* Scopes the domain. */ + create_scoped_domain(_metadata, + LANDLOCK_SCOPED_ABSTRACT_UNIX_SOCKET); + + /* + * Connected socket sends data to the receiver, but the + * non-connected socket must fail to send data. + */ + ASSERT_NE(-1, send(conn_sock, buf_data, sizeof(buf_data), 0)); + ASSERT_EQ(-1, sendto(non_conn_sock, buf_data, sizeof(buf_data), + 0, &non_connected_addr.unix_addr, + non_connected_addr.unix_addr_len)); + ASSERT_EQ(EPERM, errno); + ASSERT_EQ(1, write(pipe_child[1], ".", 1)); + + EXPECT_EQ(0, close(conn_sock)); + EXPECT_EQ(0, close(non_conn_sock)); + _exit(_metadata->exit_code); + return; + } + ASSERT_EQ(0, close(pipe_parent[0])); + ASSERT_EQ(0, close(pipe_child[1])); + + conn_sock = socket(AF_UNIX, SOCK_DGRAM, 0); + non_conn_sock = socket(AF_UNIX, SOCK_DGRAM, 0); + ASSERT_NE(-1, conn_sock); + ASSERT_NE(-1, non_conn_sock); + + ASSERT_EQ(0, bind(conn_sock, &connected_addr.unix_addr, + connected_addr.unix_addr_len)); + ASSERT_EQ(0, bind(non_conn_sock, &non_connected_addr.unix_addr, + non_connected_addr.unix_addr_len)); + + ASSERT_EQ(1, write(pipe_parent[1], ".", 1)); + + ASSERT_EQ(1, read(pipe_child[0], &buf, 1)); + num_bytes = recv(conn_sock, data, sizeof(data) - 1, 0); + ASSERT_NE(-1, num_bytes); + num_bytes = recv(non_conn_sock, data, sizeof(data) - 1, 0); + ASSERT_NE(-1, num_bytes); + + /* + * Connected datagram socket will receive data, but + * non-connected datagram socket does not receive data. + */ + ASSERT_EQ(1, read(pipe_child[0], &buf, 1)); + num_bytes = recv(conn_sock, data, sizeof(data) - 1, 0); + ASSERT_NE(-1, num_bytes); + + EXPECT_EQ(0, close(conn_sock)); + EXPECT_EQ(0, close(non_conn_sock)); + ASSERT_EQ(child, waitpid(child, &status, 0)); + if (WIFSIGNALED(status) || !WIFEXITED(status) || + WEXITSTATUS(status) != EXIT_SUCCESS) + _metadata->exit_code = KSFT_FAIL; +} + TEST_HARNESS_MAIN
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2.34.1