fix use-after-free when an interface event is pending while the interface is being...
[project/netifd.git] / interface.c
index d0eec4a..0aa5c5a 100644 (file)
@@ -17,6 +17,8 @@ enum {
        IFACE_ATTR_IFNAME,
        IFACE_ATTR_PROTO,
        IFACE_ATTR_AUTO,
+       IFACE_ATTR_DEFAULTROUTE,
+       IFACE_ATTR_METRIC,
        IFACE_ATTR_MAX
 };
 
@@ -24,6 +26,8 @@ static const struct blobmsg_policy iface_attrs[IFACE_ATTR_MAX] = {
        [IFACE_ATTR_PROTO] = { .name = "proto", .type = BLOBMSG_TYPE_STRING },
        [IFACE_ATTR_IFNAME] = { .name = "ifname", .type = BLOBMSG_TYPE_STRING },
        [IFACE_ATTR_AUTO] = { .name = "auto", .type = BLOBMSG_TYPE_BOOL },
+       [IFACE_ATTR_DEFAULTROUTE] = { .name = "defaultroute", .type = BLOBMSG_TYPE_BOOL },
+       [IFACE_ATTR_METRIC] = { .name = "metric", .type = BLOBMSG_TYPE_INT32 },
 };
 
 const struct config_param_list interface_attr_list = {
@@ -77,6 +81,42 @@ void interface_add_error(struct interface *iface, const char *subsystem,
 }
 
 static void
+interface_data_del(struct interface *iface, struct interface_data *data)
+{
+       avl_delete(&iface->data, &data->node);
+       free(data);
+}
+
+static void
+interface_data_flush(struct interface *iface)
+{
+       struct interface_data *d, *tmp;
+
+       avl_for_each_element_safe(&iface->data, d, node, tmp)
+               interface_data_del(iface, d);
+}
+
+int
+interface_add_data(struct interface *iface, const struct blob_attr *data)
+{
+       struct interface_data *n, *o;
+
+       if (!blobmsg_check_attr(data, true))
+               return UBUS_STATUS_INVALID_ARGUMENT;
+
+       n = calloc(1, sizeof(*data) + blob_pad_len(data));
+       memcpy(n->data, data, blob_pad_len(data));
+       n->node.key = blobmsg_name(data);
+
+       o = avl_find_element(&iface->data, n->node.key, o, node);
+       if (o)
+               interface_data_del(iface, o);
+
+       avl_insert(&iface->data, &n->node);
+       return 0;
+}
+
+static void
 interface_event(struct interface *iface, enum interface_event ev)
 {
        struct interface_user *dep, *tmp;
@@ -90,16 +130,18 @@ interface_event(struct interface *iface, enum interface_event ev)
 static void
 interface_flush_state(struct interface *iface)
 {
-       interface_ip_flush(&iface->proto_ip);
        if (iface->main_dev.dev)
                device_release(&iface->main_dev);
-       if (iface->l3_dev != &iface->main_dev && iface->l3_dev->dev)
-               device_release(iface->l3_dev);
+       if (iface->l3_dev.dev)
+               device_release(&iface->l3_dev);
+       interface_data_flush(iface);
 }
 
 static void
 mark_interface_down(struct interface *iface)
 {
+       if (iface->state == IFS_UP)
+               interface_event(iface, IFEV_DOWN);
        interface_flush_state(iface);
        iface->state = IFS_DOWN;
 }
@@ -113,8 +155,11 @@ __interface_set_down(struct interface *iface, bool force)
                iface->state == IFS_TEARDOWN)
                return;
 
+       if (iface->state == IFS_UP)
+               interface_event(iface, IFEV_DOWN);
        iface->state = IFS_TEARDOWN;
-       interface_event(iface, IFEV_DOWN);
+       interface_ip_flush(&iface->config_ip);
+       interface_ip_flush(&iface->proto_ip);
        interface_proto_event(iface->proto, PROTO_CMD_TEARDOWN, force);
        if (force)
                interface_flush_state(iface);
@@ -178,36 +223,39 @@ interface_claim_device(struct interface *iface)
 {
        struct device *dev;
 
-       if (iface->ifname && iface->proto_handler &&
+       if (iface->ifname &&
                !(iface->proto_handler->flags & PROTO_FLAG_NODEV)) {
                dev = device_get(iface->ifname, true);
                if (dev)
-                       device_add_user(&iface->main_dev, dev);
+                       interface_set_main_dev(iface, dev);
        }
+       if (iface->proto_handler->flags & PROTO_FLAG_INIT_AVAILABLE)
+               interface_set_available(iface, true);
 }
 
 
 static void
-interface_cleanup(struct interface *iface)
+interface_cleanup(struct interface *iface, bool reload)
 {
        struct interface_user *dep, *tmp;
 
        list_for_each_entry_safe(dep, tmp, &iface->users, list)
                interface_remove_user(dep);
 
+       interface_dequeue_event(iface);
        interface_ip_flush(&iface->config_ip);
        interface_flush_state(iface);
        interface_clear_errors(iface);
-       if (iface->main_dev.dev)
-               device_remove_user(&iface->main_dev);
-       iface->l3_dev = &iface->main_dev;
+       if (iface->main_dev.dev &&
+           (!reload || !iface->main_dev.hotplug))
+               interface_set_main_dev(iface, NULL);
        interface_set_proto_state(iface, NULL);
 }
 
 static void
 interface_do_free(struct interface *iface)
 {
-       interface_cleanup(iface);
+       interface_cleanup(iface, false);
        free(iface->config);
        netifd_ubus_remove_interface(iface);
        avl_delete(&interfaces.avl, &iface->node.avl);
@@ -217,7 +265,7 @@ interface_do_free(struct interface *iface)
 static void
 interface_do_reload(struct interface *iface)
 {
-       interface_cleanup(iface);
+       interface_cleanup(iface, true);
        proto_init_interface(iface, iface->config);
        interface_claim_device(iface);
 }
@@ -272,8 +320,9 @@ interface_proto_cb(struct interface_proto_state *state, enum interface_proto_eve
                        return;
 
                netifd_log_message(L_NOTICE, "Interface '%s' has lost the connection\n", iface->name);
+               if (iface->state == IFS_UP)
+                       interface_event(iface, IFEV_DOWN);
                iface->state = IFS_SETUP;
-               interface_event(iface, IFEV_DOWN);
                break;
        }
 }
@@ -307,10 +356,10 @@ interface_init(struct interface *iface, const char *name,
        INIT_LIST_HEAD(&iface->hotplug_list);
        interface_ip_init(&iface->proto_ip, iface);
        interface_ip_init(&iface->config_ip, iface);
+       avl_init(&iface->data, avl_strcmp, false, NULL);
        iface->config_ip.enabled = false;
 
        iface->main_dev.cb = interface_cb;
-       iface->l3_dev = &iface->main_dev;
 
        blobmsg_parse(iface_attrs, IFACE_ATTR_MAX, tb,
                      blob_data(config), blob_len(config));
@@ -320,10 +369,10 @@ interface_init(struct interface *iface, const char *name,
 
        proto_attach_interface(iface, proto_name);
 
-       if ((cur = tb[IFACE_ATTR_AUTO]))
-               iface->autostart = blobmsg_get_bool(cur);
-       else
-               iface->autostart = true;
+       iface->autostart = blobmsg_get_bool_default(tb[IFACE_ATTR_AUTO], true);
+       iface->proto_ip.no_defaultroute =
+               !blobmsg_get_bool_default(tb[IFACE_ATTR_DEFAULTROUTE], true);
+
        iface->config_autostart = iface->autostart;
 }
 
@@ -340,20 +389,65 @@ interface_add(struct interface *iface, struct blob_attr *config)
                iface->ifname = blobmsg_data(cur);
 
        iface->config = config;
-       vlist_add(&interfaces, &iface->node);
+       vlist_add(&interfaces, &iface->node, iface->name);
 }
 
 void
-interface_remove_link(struct interface *iface, struct device *dev)
+interface_set_l3_dev(struct interface *iface, struct device *dev)
 {
-       struct device *mdev = iface->main_dev.dev;
+       bool enabled = iface->config_ip.enabled;
+       bool claimed = iface->l3_dev.claimed;
 
-       if (mdev && mdev->hotplug_ops) {
-               mdev->hotplug_ops->del(mdev, dev);
+       if (iface->l3_dev.dev == dev)
                return;
+
+       interface_ip_set_enabled(&iface->config_ip, false);
+       interface_ip_flush(&iface->proto_ip);
+       device_add_user(&iface->l3_dev, dev);
+
+       if (dev) {
+               if (claimed)
+                       device_claim(&iface->l3_dev);
+               interface_ip_set_enabled(&iface->config_ip, enabled);
        }
+}
+
+void
+interface_set_main_dev(struct interface *iface, struct device *dev)
+{
+       bool set_l3 = (iface->main_dev.dev == iface->l3_dev.dev);
+       bool claimed = iface->l3_dev.claimed;
+
+       if (iface->main_dev.dev == dev)
+               return;
+
+       if (set_l3)
+               interface_set_l3_dev(iface, dev);
+
+       device_add_user(&iface->main_dev, dev);
+       if (claimed)
+               device_claim(&iface->l3_dev);
+
+       if (!iface->l3_dev.dev)
+               interface_set_l3_dev(iface, dev);
+}
+
+int
+interface_remove_link(struct interface *iface, struct device *dev)
+{
+       struct device *mdev = iface->main_dev.dev;
+
+       if (mdev && mdev->hotplug_ops)
+               return mdev->hotplug_ops->del(mdev, dev);
+
+       if (!iface->main_dev.hotplug)
+               return UBUS_STATUS_INVALID_ARGUMENT;
+
+       if (dev != iface->main_dev.dev)
+               return UBUS_STATUS_INVALID_ARGUMENT;
 
        device_remove_user(&iface->main_dev);
+       return 0;
 }
 
 int
@@ -361,14 +455,21 @@ interface_add_link(struct interface *iface, struct device *dev)
 {
        struct device *mdev = iface->main_dev.dev;
 
-       if (mdev && mdev->hotplug_ops)
-               return mdev->hotplug_ops->add(mdev, dev);
+       if (mdev == dev)
+               return 0;
 
-       if (iface->main_dev.dev)
-               interface_remove_link(iface, NULL);
+       if (iface->main_dev.hotplug)
+               device_remove_user(&iface->main_dev);
 
-       device_add_user(&iface->main_dev, dev);
+       if (mdev) {
+               if (mdev->hotplug_ops)
+                       return mdev->hotplug_ops->add(mdev, dev);
+               else
+                       return UBUS_STATUS_NOT_SUPPORTED;
+       }
 
+       interface_set_main_dev(iface, dev);
+       iface->main_dev.hotplug = true;
        return 0;
 }
 
@@ -452,8 +553,8 @@ interface_update_complete(struct interface *iface)
 
        interface_ip_update_complete(&iface->proto_ip);
        vlist_for_each_element(&iface->config_ip.route, route, node) {
-               if (iface->l3_dev->dev) {
-                       system_add_route(iface->l3_dev->dev, route);
+               if (iface->l3_dev.dev) {
+                       system_add_route(iface->l3_dev.dev, route);
                        route->enabled = true;
                }
        }
@@ -475,8 +576,9 @@ interface_change_config(struct interface *if_old, struct interface *if_new)
        if_old->ifname = if_new->ifname;
        if_old->proto_handler = if_new->proto_handler;
 
-       if (strcmp(old_ifname, if_new->ifname) != 0 ||
-               proto != if_new->proto_handler) {
+       if ((!!old_ifname != !!if_new->ifname) ||
+           (old_ifname && strcmp(old_ifname, if_new->ifname) != 0) ||
+           proto != if_new->proto_handler) {
                D(INTERFACE, "Reload interface '%s' because of ifname/proto change\n",
                  if_old->name);
                goto reload;
@@ -492,6 +594,21 @@ interface_change_config(struct interface *if_old, struct interface *if_new)
                goto reload;
        }
 
+#define UPDATE(field) ({                                               \
+               bool __changed = (if_old->field != if_new->field);      \
+               if_old->field = if_new->field;                          \
+               __changed;                                              \
+       })
+
+       if (UPDATE(metric) || UPDATE(proto_ip.no_defaultroute)) {
+               interface_ip_set_enabled(&if_old->config_ip, false);
+               interface_ip_set_enabled(&if_old->config_ip, if_new->config_ip.enabled);
+               interface_ip_set_enabled(&if_old->proto_ip, false);
+               interface_ip_set_enabled(&if_old->proto_ip, if_new->proto_ip.enabled);
+       }
+
+#undef UPDATE
+
        goto out;
 
 reload:
@@ -516,8 +633,8 @@ interface_update(struct vlist_tree *tree, struct vlist_node *node_new,
                set_config_state(if_old, IFC_REMOVE);
        } else if (node_new) {
                D(INTERFACE, "Create interface '%s'\n", if_new->name);
-               interface_claim_device(if_new);
                proto_init_interface(if_new, if_new->config);
+               interface_claim_device(if_new);
                netifd_ubus_add_interface(if_new);
        }
 }
@@ -526,8 +643,7 @@ interface_update(struct vlist_tree *tree, struct vlist_node *node_new,
 static void __init
 interface_init_list(void)
 {
-       vlist_init(&interfaces, avl_strcmp, interface_update,
-                  struct interface, node, name);
+       vlist_init(&interfaces, avl_strcmp, interface_update);
        interfaces.keep_old = true;
        interfaces.no_delete = true;
 }