dbus: add infrastructure for changing multiple properties at once on units and hook some cgroup attributes up to it

This introduces two bus calls to make runtime changes to selected bus
properties, optionally with persistence.

This currently hooks this up only for three cgroup atributes, but this
brings the infrastructure to add more changable attributes.

This allows setting multiple attributes at once, and takes an array
rather than a dictionary of properties, in order to implement simple
resetting of lists using the same approach as when they are sourced from
unit files. This means, that list properties are appended to by this
call, unless they are first reset via assigning the empty list.

1 files changed, 106 insertions, 0 deletions

diff --git a/src/systemctl/systemctl.c b/src/systemctl/systemctl.c
index a4f8f2326e..1f81bda7e3 100644
--- a/src/systemctl/systemctl.c
+++ b/src/systemctl/systemctl.c
@@ -3596,6 +3596,109 @@ static int show(DBusConnection *bus, char **args) {
         return ret;
 }
 
+static int append_assignment(DBusMessageIter *iter, const char *assignment) {
+        const char *eq;
+        char *field;
+        DBusMessageIter sub;
+        int r;
+
+        assert(iter);
+        assert(assignment);
+
+        eq = strchr(assignment, '=');
+        if (!eq) {
+                log_error("Not an assignment: %s", assignment);
+                return -EINVAL;
+        }
+
+        field = strndupa(assignment, eq - assignment);
+        eq ++;
+
+        if (!dbus_message_iter_append_basic(iter, DBUS_TYPE_STRING, &field))
+                return log_oom();
+
+        if (streq(field, "CPUAccounting") ||
+            streq(field, "MemoryAccounting") ||
+            streq(field, "BlockIOAccounting")) {
+                dbus_bool_t b;
+
+                r = parse_boolean(eq);
+                if (r < 0) {
+                        log_error("Failed to parse boolean assignment %s.", assignment);
+                        return -EINVAL;
+                }
+
+                b = r;
+                if (!dbus_message_iter_open_container(iter, DBUS_TYPE_VARIANT, "b", &sub) ||
+                    !dbus_message_iter_append_basic(&sub, DBUS_TYPE_BOOLEAN, &b))
+                        return log_oom();
+        } else {
+                log_error("Unknown assignment %s.", assignment);
+                return -EINVAL;
+        }
+
+        if (!dbus_message_iter_close_container(iter, &sub))
+                return log_oom();
+
+        return 0;
+}
+
+static int set_property(DBusConnection *bus, char **args) {
+
+        _cleanup_free_ DBusMessage *m = NULL, *reply = NULL;
+        DBusMessageIter iter, sub;
+        dbus_bool_t runtime;
+        DBusError error;
+        char **i;
+        int r;
+
+        dbus_error_init(&error);
+
+        m = dbus_message_new_method_call(
+                        "org.freedesktop.systemd1",
+                        "/org/freedesktop/systemd1",
+                        "org.freedesktop.systemd1.Manager",
+                        "SetUnitProperties");
+        if (!m)
+                return log_oom();
+
+        dbus_message_iter_init_append(m, &iter);
+
+        runtime = arg_runtime;
+
+        if (!dbus_message_iter_append_basic(&iter, DBUS_TYPE_STRING, &args[1]) ||
+            !dbus_message_iter_append_basic(&iter, DBUS_TYPE_BOOLEAN, &runtime) ||
+            !dbus_message_iter_open_container(&iter, DBUS_TYPE_ARRAY, "(sv)", &sub))
+                return log_oom();
+
+        STRV_FOREACH(i, args + 2) {
+                DBusMessageIter sub2;
+
+                if (!dbus_message_iter_open_container(&sub, DBUS_TYPE_STRUCT, NULL, &sub2))
+                        return log_oom();
+
+                r = append_assignment(&sub2, *i);
+                if (r < 0)
+                        return r;
+
+                if (!dbus_message_iter_close_container(&sub, &sub2))
+                        return log_oom();
+
+        }
+
+        if (!dbus_message_iter_close_container(&iter, &sub))
+                return log_oom();
+
+        reply = dbus_connection_send_with_reply_and_block(bus, m, -1, &error);
+        if (!reply) {
+                log_error("Failed to issue method call: %s", bus_error_message(&error));
+                dbus_error_free(&error);
+                return -EIO;
+        }
+
+        return 0;
+}
+
 static int dump(DBusConnection *bus, char **args) {
         _cleanup_free_ DBusMessage *reply = NULL;
         DBusError error;
@@ -4560,6 +4663,8 @@ static int systemctl_help(void) {
                "  status [NAME...|PID...]         Show runtime status of one or more units\n"
                "  show [NAME...|JOB...]           Show properties of one or more\n"
                "                                  units/jobs or the manager\n"
+               "  set-property [NAME] [ASSIGNMENT...]\n"
+               "                                  Sets one or more properties of a unit\n"
                "  help [NAME...|PID...]           Show manual for one or more units\n"
                "  reset-failed [NAME...]          Reset failed state for all, one, or more\n"
                "                                  units\n"
@@ -5639,6 +5744,7 @@ static int systemctl_main(DBusConnection *bus, int argc, char *argv[], DBusError
                 { "set-default",           EQUAL, 2, enable_unit       },
                 { "get-default",           LESS,  1, get_default       },
                 { "set-log-level",         EQUAL, 2, set_log_level     },
+                { "set-property",          MORE,  3, set_property      },
         };
 
         int left;