net: devlink: limit flash component name to match version returned by info_get()

Limit the acceptance of component name passed to cmd_flash_update() to
match one of the versions returned by info_get(), marked by version type.
This makes things clearer and enforces 1:1 mapping between exposed
version and accepted flash component.

Check VERSION_TYPE_COMPONENT version type during cmd_flash_update()
execution by calling info_get() with different "req" context.
That causes info_get() to lookup the component name instead of
filling-up the netlink message.

Remove "UPDATE_COMPONENT" flag which becomes used.
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/netdevsim/dev.c

@@ -1322,8 +1322,7 @@ nsim_dev_devlink_trap_drop_counter_get(struct devlink *devlink,
 static const struct devlink_ops nsim_dev_devlink_ops = {
 	.eswitch_mode_set = nsim_devlink_eswitch_mode_set,
 	.eswitch_mode_get = nsim_devlink_eswitch_mode_get,
-	.supported_flash_update_params = DEVLINK_SUPPORT_FLASH_UPDATE_COMPONENT |
-					 DEVLINK_SUPPORT_FLASH_UPDATE_OVERWRITE_MASK,
+	.supported_flash_update_params = DEVLINK_SUPPORT_FLASH_UPDATE_OVERWRITE_MASK,
 	.reload_actions = BIT(DEVLINK_RELOAD_ACTION_DRIVER_REINIT),
 	.reload_down = nsim_dev_reload_down,
 	.reload_up = nsim_dev_reload_up,

include/net/devlink.h

@@ -624,8 +624,7 @@ struct devlink_flash_update_params {
 	u32 overwrite_mask;
 };
 
-#define DEVLINK_SUPPORT_FLASH_UPDATE_COMPONENT		BIT(0)
-#define DEVLINK_SUPPORT_FLASH_UPDATE_OVERWRITE_MASK	BIT(1)
+#define DEVLINK_SUPPORT_FLASH_UPDATE_OVERWRITE_MASK	BIT(0)
 
 struct devlink_region;
 struct devlink_info_req;

net/core/devlink.c

@@ -4742,10 +4742,76 @@ void devlink_flash_update_timeout_notify(struct devlink *devlink,
 }
 EXPORT_SYMBOL_GPL(devlink_flash_update_timeout_notify);
 
+struct devlink_info_req {
+	struct sk_buff *msg;
+	void (*version_cb)(const char *version_name,
+			   enum devlink_info_version_type version_type,
+			   void *version_cb_priv);
+	void *version_cb_priv;
+};
+
+struct devlink_flash_component_lookup_ctx {
+	const char *lookup_name;
+	bool lookup_name_found;
+};
+
+static void
+devlink_flash_component_lookup_cb(const char *version_name,
+				  enum devlink_info_version_type version_type,
+				  void *version_cb_priv)
+{
+	struct devlink_flash_component_lookup_ctx *lookup_ctx = version_cb_priv;
+
+	if (version_type != DEVLINK_INFO_VERSION_TYPE_COMPONENT ||
+	    lookup_ctx->lookup_name_found)
+		return;
+
+	lookup_ctx->lookup_name_found =
+		!strcmp(lookup_ctx->lookup_name, version_name);
+}
+
+static int devlink_flash_component_get(struct devlink *devlink,
+				       struct nlattr *nla_component,
+				       const char **p_component,
+				       struct netlink_ext_ack *extack)
+{
+	struct devlink_flash_component_lookup_ctx lookup_ctx = {};
+	struct devlink_info_req req = {};
+	const char *component;
+	int ret;
+
+	if (!nla_component)
+		return 0;
+
+	component = nla_data(nla_component);
+
+	if (!devlink->ops->info_get) {
+		NL_SET_ERR_MSG_ATTR(extack, nla_component,
+				    "component update is not supported by this device");
+		return -EOPNOTSUPP;
+	}
+
+	lookup_ctx.lookup_name = component;
+	req.version_cb = devlink_flash_component_lookup_cb;
+	req.version_cb_priv = &lookup_ctx;
+
+	ret = devlink->ops->info_get(devlink, &req, NULL);
+	if (ret)
+		return ret;
+
+	if (!lookup_ctx.lookup_name_found) {
+		NL_SET_ERR_MSG_ATTR(extack, nla_component,
+				    "selected component is not supported by this device");
+		return -EINVAL;
+	}
+	*p_component = component;
+	return 0;
+}
+
 static int devlink_nl_cmd_flash_update(struct sk_buff *skb,
 				       struct genl_info *info)
 {
-	struct nlattr *nla_component, *nla_overwrite_mask, *nla_file_name;
+	struct nlattr *nla_overwrite_mask, *nla_file_name;
 	struct devlink_flash_update_params params = {};
 	struct devlink *devlink = info->user_ptr[0];
 	const char *file_name;
@@ -4758,17 +4824,13 @@ static int devlink_nl_cmd_flash_update(struct sk_buff *skb,
 	if (!info->attrs[DEVLINK_ATTR_FLASH_UPDATE_FILE_NAME])
 		return -EINVAL;
 
-	supported_params = devlink->ops->supported_flash_update_params;
+	ret = devlink_flash_component_get(devlink,
+					  info->attrs[DEVLINK_ATTR_FLASH_UPDATE_COMPONENT],
+					  &params.component, info->extack);
+	if (ret)
+		return ret;
 
-	nla_component = info->attrs[DEVLINK_ATTR_FLASH_UPDATE_COMPONENT];
-	if (nla_component) {
-		if (!(supported_params & DEVLINK_SUPPORT_FLASH_UPDATE_COMPONENT)) {
-			NL_SET_ERR_MSG_ATTR(info->extack, nla_component,
-					    "component update is not supported by this device");
-			return -EOPNOTSUPP;
-		}
-		params.component = nla_data(nla_component);
-	}
+	supported_params = devlink->ops->supported_flash_update_params;
 
 	nla_overwrite_mask = info->attrs[DEVLINK_ATTR_FLASH_UPDATE_OVERWRITE_MASK];
 	if (nla_overwrite_mask) {
@@ -6553,18 +6615,18 @@ static int devlink_nl_cmd_region_read_dumpit(struct sk_buff *skb,
 	return err;
 }
 
-struct devlink_info_req {
-	struct sk_buff *msg;
-};
-
 int devlink_info_driver_name_put(struct devlink_info_req *req, const char *name)
 {
+	if (!req->msg)
+		return 0;
 	return nla_put_string(req->msg, DEVLINK_ATTR_INFO_DRIVER_NAME, name);
 }
 EXPORT_SYMBOL_GPL(devlink_info_driver_name_put);
 
 int devlink_info_serial_number_put(struct devlink_info_req *req, const char *sn)
 {
+	if (!req->msg)
+		return 0;
 	return nla_put_string(req->msg, DEVLINK_ATTR_INFO_SERIAL_NUMBER, sn);
 }
 EXPORT_SYMBOL_GPL(devlink_info_serial_number_put);
@@ -6572,6 +6634,8 @@ EXPORT_SYMBOL_GPL(devlink_info_serial_number_put);
 int devlink_info_board_serial_number_put(struct devlink_info_req *req,
 					 const char *bsn)
 {
+	if (!req->msg)
+		return 0;
 	return nla_put_string(req->msg, DEVLINK_ATTR_INFO_BOARD_SERIAL_NUMBER,
 			      bsn);
 }
@@ -6585,6 +6649,13 @@ static int devlink_info_version_put(struct devlink_info_req *req, int attr,
 	struct nlattr *nest;
 	int err;
 
+	if (req->version_cb)
+		req->version_cb(version_name, version_type,
+				req->version_cb_priv);
+
+	if (!req->msg)
+		return 0;
+
 	nest = nla_nest_start_noflag(req->msg, attr);
 	if (!nest)
 		return -EMSGSIZE;
@@ -6665,7 +6736,7 @@ devlink_nl_info_fill(struct sk_buff *msg, struct devlink *devlink,
 		     enum devlink_command cmd, u32 portid,
 		     u32 seq, int flags, struct netlink_ext_ack *extack)
 {
-	struct devlink_info_req req;
+	struct devlink_info_req req = {};
 	void *hdr;
 	int err;
 
@@ -12332,8 +12403,8 @@ EXPORT_SYMBOL_GPL(devl_trap_policers_unregister);
 static void __devlink_compat_running_version(struct devlink *devlink,
 					     char *buf, size_t len)
 {
+	struct devlink_info_req req = {};
 	const struct nlattr *nlattr;
-	struct devlink_info_req req;
 	struct sk_buff *msg;
 	int rem, err;