feat(storage/vfs): Make lwip specific API private

components/vfs/include/esp_private/socket.h

@@ -0,0 +1,34 @@
+/*
+ * SPDX-FileCopyrightText: 2025 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+#pragma once
+
+#include "esp_vfs.h"
+#include "esp_err.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * Special case function for registering a VFS that uses a method other than
+ * open() to open new file descriptors from the interval <min_fd; max_fd).
+ *
+ * This is a special-purpose function intended for registering LWIP sockets to VFS.
+ *
+ * @param vfs Pointer to esp_vfs_fs_ops_t. Meaning is the same as for esp_vfs_register_fs().
+ * @param ctx Pointer to context structure. Meaning is the same as for esp_vfs_register_fs().
+ * @param min_fd The smallest file descriptor this VFS will use.
+ * @param max_fd Upper boundary for file descriptors this VFS will use (the biggest file descriptor plus one).
+ *
+ * @return  ESP_OK if successful,
+ *          ESP_ERR_NO_MEM if too many VFSes are registered,
+ *          ESP_ERR_INVALID_ARG if the file descriptor boundaries are incorrect.
+ */
+esp_err_t esp_vfs_register_fd_range(const esp_vfs_fs_ops_t *vfs, int flags, void *ctx, int min_fd, int max_fd);
+
+#ifdef __cplusplus
+}
+#endif