devlink: introduce devlink_nl_pre_doit_port*() helper functions

Define port handling helpers what don't rely on internal_flags.
Have __devlink_nl_pre_doit() to accept the flags as a function arg and
make devlink_nl_pre_doit() a wrapper helper function calling it.
Introduce new helpers devlink_nl_pre_doit_port() and
devlink_nl_pre_doit_port_optional() to be used by split ops in follow-up
patch.

Note that the function prototypes are temporary until the generated ones
will replace them in a follow-up patch.
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/20230811155714.1736405-4-jiri@resnulli.usSigned-off-by: Jakub Kicinski <kuba@kernel.org>

net/devlink/devl_internal.h

@@ -205,6 +205,11 @@ int devlink_rate_nodes_check(struct devlink *devlink, u16 mode,
 			     struct netlink_ext_ack *extack);
 
 /* Devlink nl cmds */
+int devlink_nl_pre_doit_port(const struct genl_split_ops *ops,
+			     struct sk_buff *skb, struct genl_info *info);
+int devlink_nl_pre_doit_port_optional(const struct genl_split_ops *ops,
+				      struct sk_buff *skb,
+				      struct genl_info *info);
 int devlink_nl_cmd_reload(struct sk_buff *skb, struct genl_info *info);
 int devlink_nl_cmd_eswitch_get_doit(struct sk_buff *skb, struct genl_info *info);
 int devlink_nl_cmd_eswitch_set_doit(struct sk_buff *skb, struct genl_info *info);

net/devlink/netlink.c

@@ -109,8 +109,8 @@ devlink_get_from_attrs_lock(struct net *net, struct nlattr **attrs)
 	return ERR_PTR(-ENODEV);
 }
 
-int devlink_nl_pre_doit(const struct genl_split_ops *ops,
-			struct sk_buff *skb, struct genl_info *info)
+static int __devlink_nl_pre_doit(struct sk_buff *skb, struct genl_info *info,
+				 u8 flags)
 {
 	struct devlink_port *devlink_port;
 	struct devlink *devlink;
@@ -121,14 +121,14 @@ int devlink_nl_pre_doit(const struct genl_split_ops *ops,
 		return PTR_ERR(devlink);
 
 	info->user_ptr[0] = devlink;
-	if (ops->internal_flags & DEVLINK_NL_FLAG_NEED_PORT) {
+	if (flags & DEVLINK_NL_FLAG_NEED_PORT) {
 		devlink_port = devlink_port_get_from_info(devlink, info);
 		if (IS_ERR(devlink_port)) {
 			err = PTR_ERR(devlink_port);
 			goto unlock;
 		}
 		info->user_ptr[1] = devlink_port;
-	} else if (ops->internal_flags & DEVLINK_NL_FLAG_NEED_DEVLINK_OR_PORT) {
+	} else if (flags & DEVLINK_NL_FLAG_NEED_DEVLINK_OR_PORT) {
 		devlink_port = devlink_port_get_from_info(devlink, info);
 		if (!IS_ERR(devlink_port))
 			info->user_ptr[1] = devlink_port;
@@ -141,6 +141,25 @@ int devlink_nl_pre_doit(const struct genl_split_ops *ops,
 	return err;
 }
 
+int devlink_nl_pre_doit(const struct genl_split_ops *ops,
+			struct sk_buff *skb, struct genl_info *info)
+{
+	return __devlink_nl_pre_doit(skb, info, ops->internal_flags);
+}
+
+int devlink_nl_pre_doit_port(const struct genl_split_ops *ops,
+			     struct sk_buff *skb, struct genl_info *info)
+{
+	return __devlink_nl_pre_doit(skb, info, DEVLINK_NL_FLAG_NEED_PORT);
+}
+
+int devlink_nl_pre_doit_port_optional(const struct genl_split_ops *ops,
+				      struct sk_buff *skb,
+				      struct genl_info *info)
+{
+	return __devlink_nl_pre_doit(skb, info, DEVLINK_NL_FLAG_NEED_DEVLINK_OR_PORT);
+}
+
 void devlink_nl_post_doit(const struct genl_split_ops *ops,
 			  struct sk_buff *skb, struct genl_info *info)
 {