Include udev properties in emulated netlink messages

Current systemd by and large does not read the /uevent file any more,
but entirely relies on udevd sending the properties in the udev netlink
events.

Pass the properties to uevent_sender_send(), massage them from a
newline separated (as in our uevent file) to a nul separated (as
expected by the udev netlink message) array. In Testbed.uevent(), read
the current properties from the /uevent file.

This is all rather hackish right now and cries for a more thorough
rewrite. But this is a relatively unintrusive and quick bandaid which
helps users for the time being.

Test this both with the libudev and with the gudev (through Python) APIs.

Fixes martinpitt#164

src/uevent_sender.c

@@ -224,7 +224,7 @@ append_property(char *array, size_t size, size_t offset, const char *name, const
 /* this mirrors the code from systemd/src/libsystemd/sd-device/device-monitor.c,
  * device_monitor_send_device() */
 void
-uevent_sender_send(uevent_sender * sender, const char *devpath, const char *action)
+uevent_sender_send(uevent_sender * sender, const char *devpath, const char *action, const char *properties)
 {
     char buffer[1024];
     size_t buffer_len = 0;
@@ -261,6 +261,20 @@ uevent_sender_send(uevent_sender * sender, const char *devpath, const char *acti
     if (devtype)
         buffer_len += append_property(buffer, sizeof buffer, buffer_len, "DEVTYPE=", devtype);
 
+    /* append udevd (userland) properties, replace \n with \0 */
+    /* FIXME: more sensible API */
+    size_t properties_len = properties ? strlen(properties) : 0;
+    if (properties_len > 0) {
+        size_t prop_ofs = buffer_len;
+        buffer_len += append_property(buffer, sizeof buffer, buffer_len, properties, "");
+        for (size_t i = prop_ofs; i < buffer_len - 1; ++i)
+            if (buffer[i] == '\n')
+                buffer[i] = '\0';
+        /* avoid empty property at the end from final line break */
+        if (properties[strlen(properties) - 1] == '\n')
+            --buffer_len;
+    }
+
     /* add versioned header */
     memset(&nlh, 0x00, sizeof(struct udev_monitor_netlink_header));
     memcpy(nlh.prefix, "libudev", 8);

src/uevent_sender.h

@@ -23,6 +23,6 @@ typedef struct _uevent_sender uevent_sender;
 
 uevent_sender *uevent_sender_open(const char *rootpath);
 void uevent_sender_close(uevent_sender * sender);
-void uevent_sender_send(uevent_sender * sender, const char *devpath, const char *action);
+void uevent_sender_send(uevent_sender * sender, const char *devpath, const char *action, const char *properties);
 
 #endif				/* __UEVENT_SENDER_H */

src/uevent_sender.vapi

@@ -6,6 +6,6 @@ namespace UeventSender {
   public class sender {
       [CCode (cname="uevent_sender_open")]
       public sender (string rootpath);
-      public void send (string devpath, string action);
+      public void send (string devpath, string action, string properties);
   }
 }

src/umockdev.vala

@@ -754,7 +754,15 @@ public class Testbed: GLib.Object {
             assert(this.ev_sender != null);
         }
         debug("umockdev_testbed_uevent: sending uevent %s for device %s", action, devpath);
-        this.ev_sender.send(devpath, action);
+
+        var uevent_path = Path.build_filename(this.root_dir, devpath, "uevent");
+        var properties = "";
+        try {
+            FileUtils.get_contents(uevent_path, out properties);
+        } catch (FileError e) {
+            debug("uevent: devpath %s has no uevent file: %s",  devpath, e.message);
+        }
+        this.ev_sender.send(devpath, action, properties);
     }
 
     /**

tests/test-umockdev.c

@@ -614,12 +614,16 @@ t_testbed_uevent_libudev(UMockdevTestbedFixture * fixture, UNUSED_DATA)
     g_assert(device != NULL);
     g_assert_cmpstr(udev_device_get_syspath(device), ==, syspath);
     g_assert_cmpstr(udev_device_get_action(device), ==, "add");
+    g_assert_cmpstr(udev_device_get_sysattr_value(device, "idVendor"), ==, "0815");
+    g_assert_cmpstr(udev_device_get_property_value(device, "ID_INPUT"), ==, "1");
     udev_device_unref(device);
 
     device = udev_monitor_receive_device(kernel_mon);
     g_assert(device != NULL);
     g_assert_cmpstr(udev_device_get_syspath(device), ==, syspath);
     g_assert_cmpstr(udev_device_get_action(device), ==, "add");
+    g_assert_cmpstr(udev_device_get_sysattr_value(device, "idVendor"), ==, "0815");
+    g_assert_cmpstr(udev_device_get_property_value(device, "ID_INPUT"), ==, "1");
     udev_device_unref(device);
 
     udev_monitor_unref(udev_mon);

tests/test-umockdev.py

@@ -129,7 +129,7 @@ def test_set_property(self):
     def test_uevent(self):
         '''testbed uevent()'''
 
-        counter = [0, 0, 0, None]  # add, remove, change, last device
+        counter = [0, 0, 0, None, None, None]  # add, remove, change, last device, idVendor, ID_INPUT
 
         def on_uevent(client, action, device, counters):
             if action == 'add':
@@ -138,9 +138,13 @@ def on_uevent(client, action, device, counters):
                 counters[1] += 1
             else:
                 assert action == 'change'
+                self.assertEqual(device.get_sysfs_attr('idVendor'), '0815')
+                self.assertEqual(device.get_property('ID_INPUT'), '1')
                 counters[2] += 1
 
             counters[3] = device.get_sysfs_path()
+            counters[4] = device.get_sysfs_attr('idVendor')
+            counters[5] = device.get_property('ID_INPUT')
 
         syspath = self.testbed.add_device('pci', 'mydev', None, ['idVendor', '0815'], ['ID_INPUT', '1'])
         self.assertNotEqual(syspath, None)
@@ -155,14 +159,17 @@ def on_uevent(client, action, device, counters):
         self.testbed.uevent(syspath, 'add')
         GLib.timeout_add(500, mainloop.quit)
         mainloop.run()
-        self.assertEqual(counter, [1, 0, 0, syspath])
+        self.assertEqual(counter, [1, 0, 0, syspath, '0815', '1'])
 
         counter[0] = 0
         counter[3] = None
+        counter[4] = None
+        counter[5] = None
+
         self.testbed.uevent(syspath, 'change')
         GLib.timeout_add(500, mainloop.quit)
         mainloop.run()
-        self.assertEqual(counter, [0, 0, 1, syspath])
+        self.assertEqual(counter, [0, 0, 1, syspath, '0815', '1'])
 
     def test_add_from_string(self):
         self.assertTrue(self.testbed.add_from_string ('''P: /devices/dev1