service: add service.signal ubus call

Add a service.signal call to allow sending kill() signals to a service.

The default signal sent to services is SIGHUP and may be overridden by a
numerical signal value using the signal parameter.

The optional instance argument allows restricting the signal delivery to one
specific instance. If omitted, the signal is sent to all instances.

Acked-by: John Crispin <john@phrozen.org>
Signed-off-by: Jo-Philipp Wich <jo@mein.io>

diff --git a/service/service.c b/service/service.c
index 95978b5..2c73901 100644 (file)
--- a/service/service.c
+++ b/service/service.c
@@ -190,6 +190,19 @@ static const struct blobmsg_policy service_list_attrs[__SERVICE_LIST_ATTR_MAX] =
 };
 
 enum {
+       SERVICE_SIGNAL_ATTR_NAME,
+       SERVICE_SIGNAL_ATTR_INSTANCE,
+       SERVICE_SIGNAL_ATTR_SIGNAL,
+       __SERVICE_SIGNAL_ATTR_MAX,
+};
+
+static const struct blobmsg_policy service_signal_attrs[__SERVICE_SIGNAL_ATTR_MAX] = {
+       [SERVICE_SIGNAL_ATTR_NAME] = { "name", BLOBMSG_TYPE_STRING },
+       [SERVICE_SIGNAL_ATTR_INSTANCE] = { "instance", BLOBMSG_TYPE_STRING },
+       [SERVICE_SIGNAL_ATTR_SIGNAL] = { "signal", BLOBMSG_TYPE_INT32 },
+};
+
+enum {
        EVENT_TYPE,
        EVENT_DATA,
        __EVENT_MAX
@@ -354,6 +367,63 @@ service_handle_delete(struct ubus_context *ctx, struct ubus_object *obj,
 }
 
 static int
+service_handle_kill(struct service_instance *in, int sig)
+{
+       if (kill(in->proc.pid, sig) == 0)
+               return 0;
+
+       switch (errno) {
+       case EINVAL: return UBUS_STATUS_INVALID_ARGUMENT;
+       case EPERM:  return UBUS_STATUS_PERMISSION_DENIED;
+       case ESRCH:  return UBUS_STATUS_NOT_FOUND;
+       }
+
+       return UBUS_STATUS_UNKNOWN_ERROR;
+}
+
+static int
+service_handle_signal(struct ubus_context *ctx, struct ubus_object *obj,
+                   struct ubus_request_data *req, const char *method,
+                   struct blob_attr *msg)
+{
+       struct blob_attr *tb[__SERVICE_SIGNAL_ATTR_MAX], *cur;
+       struct service *s;
+       struct service_instance *in;
+       int sig = SIGHUP;
+       int rv = 0;
+
+       blobmsg_parse(service_signal_attrs, __SERVICE_SIGNAL_ATTR_MAX, tb, blob_data(msg), blob_len(msg));
+
+       cur = tb[SERVICE_SIGNAL_ATTR_SIGNAL];
+       if (cur)
+               sig = blobmsg_get_u32(cur);
+
+       cur = tb[SERVICE_SIGNAL_ATTR_NAME];
+       if (!cur)
+               return UBUS_STATUS_NOT_FOUND;
+
+       s = avl_find_element(&services, blobmsg_data(cur), s, avl);
+       if (!s)
+               return UBUS_STATUS_NOT_FOUND;
+
+       cur = tb[SERVICE_SIGNAL_ATTR_INSTANCE];
+       if (!cur) {
+               vlist_for_each_element(&s->instances, in, node)
+                       rv = service_handle_kill(in, sig);
+
+               return rv;
+       }
+
+       in = vlist_find(&s->instances, blobmsg_data(cur), in, node);
+       if (!in) {
+               ERROR("instance %s not found\n", blobmsg_get_string(cur));
+               return UBUS_STATUS_NOT_FOUND;
+       }
+
+       return service_handle_kill(in, sig);
+}
+
+static int
 service_handle_update(struct ubus_context *ctx, struct ubus_object *obj,
                      struct ubus_request_data *req, const char *method,
                      struct blob_attr *msg)
@@ -490,6 +560,7 @@ static struct ubus_method main_object_methods[] = {
        UBUS_METHOD("add", service_handle_set, service_set_attrs),
        UBUS_METHOD("list", service_handle_list, service_list_attrs),
        UBUS_METHOD("delete", service_handle_delete, service_del_attrs),
+       UBUS_METHOD("signal", service_handle_signal, service_signal_attrs),
        UBUS_METHOD("update_start", service_handle_update, service_attrs),
        UBUS_METHOD("update_complete", service_handle_update, service_attrs),
        UBUS_METHOD("event", service_handle_event, event_policy),