core: add basic infrastructure to record unit activation information

Not wired in by any unit type yet, just the basic to allocate,
ref, deref and plug in to other unit types.
Includes recording the trigger unit name and passing it to the
triggered unit as TRIGGER_UNIT= env var.

1 files changed, 32 insertions, 0 deletions

diff --git a/src/core/dbus-util.c b/src/core/dbus-util.c
index 264a4f55b6..edfa0eb69a 100644
--- a/src/core/dbus-util.c
+++ b/src/core/dbus-util.c
@@ -228,3 +228,35 @@ int bus_read_mount_options(
 
         return 0;
 }
+
+int bus_property_get_activation_details(
+                sd_bus *bus,
+                const char *path,
+                const char *interface,
+                const char *property,
+                sd_bus_message *reply,
+                void *userdata,
+                sd_bus_error *error) {
+
+        ActivationDetails **details = ASSERT_PTR(userdata);
+        _cleanup_strv_free_ char **pairs = NULL;
+        int r;
+
+        assert(reply);
+
+        r = activation_details_append_pair(*details, &pairs);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_message_open_container(reply, 'a', "(ss)");
+        if (r < 0)
+                return r;
+
+        STRV_FOREACH_PAIR(key, value, pairs) {
+                r = sd_bus_message_append(reply, "(ss)", *key, *value);
+                if (r < 0)
+                        return r;
+        }
+
+        return sd_bus_message_close_container(reply);
+}