@@ -71,6 +71,14 @@  print_link_socket_actual(const struct link_socket_actual *act, struct gc_arena *
     return "dummy print_link_socket_actual from unit test";
 }
 
+#ifdef _WIN32
+int
+openvpn_execve(const struct argv *a, const struct env_set *es, const unsigned int flags)
+{
+    ASSERT(0);
+}
+#endif
+
 struct test_pkt_context {
     struct tls_auth_standalone tas_tls_auth;
     struct tls_auth_standalone tas_crypt;
@@ -501,7 +509,18 @@  test_calc_session_id_hmac_static(void **ut_state)
     now = 1005;
     struct session_id server_id = calculate_session_id_hmac(client_id, &addr, hmac, handwindow, 0);
 
-    struct session_id expected_server_id = { {0x84, 0x73, 0x52, 0x2b, 0x5b, 0xa9, 0x2a, 0x70 }};
+
+    struct session_id expected_server_id = {{0x84, 0x73, 0x52, 0x2b, 0x5b, 0xa9, 0x2a, 0x70}};
+    /* We have to deal with different structs here annoyingly */
+    /* Linux has an unsigned short int as family_t and this is field is always
+     * stored in host endianness even though the rest of the struct isn't...,
+     * so Linux little endian differs from all BSD and Linux big endian */
+    if (sizeof(addr.addr.in4.sin_family) == sizeof(unsigned short int)
+        && ntohs(AF_INET) != AF_INET)
+    {
+        struct session_id linuxle = {{0x8b, 0xeb, 0x3d, 0x20, 0x14, 0x53, 0xbe, 0x0a }};
+        expected_server_id = linuxle;
+    }
     assert_memory_equal(expected_server_id.id, server_id.id, SID_SIZE);
 
     struct session_id server_id_m1 = calculate_session_id_hmac(client_id, &addr, hmac, handwindow, -1);
 
  
This surprising breakage results from the fact that Linux basically uses a different structure from the *BSD: For exmaple, macOS has: struct sockaddr_in { __uint8_t sin_len; sa_family_t sin_family; in_port_t sin_port; struct in_addr sin_addr; char sin_zero[8]; }; with sa_family_t also uint8_t and Linux has stupidly complex definition that boils down to: struct sockaddr_in { uint16_t sin_family; in_port_t sin_port; struct in_addr sin_addr char sin_zero[8]; }; So Linux basically has a 16 bit uint16 instead of two uint8_t. Because s390x is big endian, this happens to be same in memory layout as on all BSDs with first byte being 0 and second byte being the family. Introduce a second array to check against, if we are on little endian Linux. This is a bit fragile but this is also just a unit test. This also fixes compiling test_pkt with windows. Signed-off-by: Arne Schwabe <arne@rfc2549.org> --- tests/unit_tests/openvpn/test_pkt.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-)