Imported Upstream version 0.0.1upstream/0.1.0upstream_backup_before_libusbg_to_libusbgx_change

Change-Id: I8c015fe84734a1020227040699dc4bbf9a081ccd

2 files changed, 726 insertions, 60 deletions

diff --git a/include/usbg/usbg.h b/include/usbg/usbg.h
index 1407f10..bcf221d 100644
--- a/include/usbg/usbg.h
+++ b/include/usbg/usbg.h
@@ -22,15 +22,20 @@
 #include <netinet/ether.h>
 #include <stdint.h>
 #include <limits.h>
+#include <stdbool.h>
+#include <stdio.h> /* For FILE * */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
 
 /**
  * @file include/usbg/usbg.h
- * @todo Add usbg_remove_[gadget|config|function|binding] APIs
  * @todo Clean up static buffers in structures
  */
 
 /**
- * @addtogroup libusbg
+ * @addtogroup libusbgx
  * Public API for USB gadget-configfs library
  * @{
  */
@@ -39,9 +44,21 @@
 #define LANG_US_ENG		0x0409
 #define DEFAULT_CONFIG_LABEL "config"
 
+/* This one has to be at least 18 bytes to hold network address */
 #define USBG_MAX_STR_LENGTH 256
 #define USBG_MAX_PATH_LENGTH PATH_MAX
 #define USBG_MAX_NAME_LENGTH 40
+/* Dev name for ffs is a part of function name, we subtract 4 char for "ffs." */
+#define USBG_MAX_DEV_LENGTH (USBG_MAX_NAME_LENGTH - 4)
+/* ConfigFS just like SysFS uses page size as max size of file content */
+#define USBG_MAX_FILE_SIZE 4096
+
+/**
+ * @brief Additional option for usbg_rm_* functions.
+ * @details This option allows to remove all content
+ * of gadget/config/function recursively.
+ */
+#define USBG_RM_RECURSE 1
 
 /*
  * Internal structures
@@ -51,6 +68,7 @@ struct usbg_gadget;
 struct usbg_config;
 struct usbg_function;
 struct usbg_binding;
+struct usbg_udc;
 
 /**
  * @brief State of the gadget devices in the system
@@ -78,6 +96,29 @@ typedef struct usbg_function usbg_function;
 typedef struct usbg_binding usbg_binding;
 
 /**
+ * @brief USB device controller
+ */
+typedef struct usbg_udc usbg_udc;
+
+/**
+ * @typedef usbg_gadget_attr
+ * @brief Gadget attributes which can be set using
+ * usbg_set_gadget_attr() function.
+ */
+typedef enum {
+	USBG_GADGET_ATTR_MIN = 0,
+	BCD_USB = USBG_GADGET_ATTR_MIN,
+	B_DEVICE_CLASS,
+	B_DEVICE_SUB_CLASS,
+	B_DEVICE_PROTOCOL,
+	B_MAX_PACKET_SIZE_0,
+	ID_VENDOR,
+	ID_PRODUCT,
+	BCD_DEVICE,
+	USBG_GADGET_ATTR_MAX,
+} usbg_gadget_attr;
+
+/**
  * @typedef usbg_gadget_attrs
  * @brief USB gadget device attributes
  */
@@ -93,6 +134,14 @@ typedef struct
 	uint16_t bcdDevice;
 } usbg_gadget_attrs;
 
+typedef enum {
+	USBG_GADGET_STR_MIN = 0,
+	STR_PRODUCT = USBG_GADGET_STR_MIN,
+	STR_MANUFACTURER,
+	STR_SERIAL_NUMBER,
+	USBG_GADGET_STR_MAX,
+} usbg_gadget_str;
+
 /**
  * @typedef usbg_gadget_strs
  * @brief USB gadget device strings
@@ -129,7 +178,8 @@ typedef struct
  */
 typedef enum
 {
-	F_SERIAL,
+	USBG_FUNCTION_TYPE_MIN = 0,
+	F_SERIAL = USBG_FUNCTION_TYPE_MIN,
 	F_ACM,
 	F_OBEX,
 	F_ECM,
@@ -138,6 +188,11 @@ typedef enum
 	F_EEM,
 	F_RNDIS,
 	F_PHONET,
+	F_FFS,
+	F_MASS_STORAGE,
+	F_MIDI,
+	F_LOOPBACK,
+	USBG_FUNCTION_TYPE_MAX,
 } usbg_function_type;
 
 /**
@@ -155,7 +210,7 @@ typedef struct {
 typedef struct {
 	struct ether_addr dev_addr;
 	struct ether_addr host_addr;
-	char ifname[USBG_MAX_STR_LENGTH];
+	const char *ifname;
 	int qmult;
 } usbg_f_net_attrs;
 
@@ -164,10 +219,66 @@ typedef struct {
  * @brief Attributes for the phonet USB function
  */
 typedef struct {
-	char ifname[USBG_MAX_STR_LENGTH];
+	const char *ifname;
 } usbg_f_phonet_attrs;
 
 /**
+ * @typedef usbg_f_ffs_attrs
+ * @brief Attributes for function fs based functions
+ * @details This is read only and a virtual attribute, it is non present
+ * on config fs.
+ */
+typedef struct {
+	const char *dev_name;
+} usbg_f_ffs_attrs;
+
+/**
+ * @typedef usbg_f_ms_attrs
+ * @brief Attributes for mass storage functions
+ */
+typedef struct usbg_f_ms_lun_attrs {
+	int id;
+	bool cdrom;
+	bool ro;
+	bool nofua;
+	bool removable;
+	const char *filename;
+} usbg_f_ms_lun_attrs;
+
+/**
+ * @typedef usbg_f_ms_attrs
+ * @brief Attributes for mass storage functions
+ */
+typedef struct {
+	bool stall;
+	int nluns;
+	usbg_f_ms_lun_attrs **luns;
+} usbg_f_ms_attrs;
+
+/**
+ * @typedef usbg_f_midi_attrs
+ * @brief Attributes for the MIDI function
+ */
+typedef struct {
+	int index;
+	const char *id;
+	unsigned int in_ports;
+	unsigned int out_ports;
+	unsigned int buflen;
+	unsigned int qlen;
+} usbg_f_midi_attrs;
+
+
+/**
+ * @typedef usbg_f_loopback_attrs
+ * @brief Attributes for Loopback function
+ */
+typedef struct {
+	unsigned int buflen;
+	unsigned int qlen;
+} usbg_f_loopback_attrs;
+
+/**
  * @typedef attrs
  * @brief Attributes for a given function type
  */
@@ -175,6 +286,29 @@ typedef union {
 	usbg_f_serial_attrs serial;
 	usbg_f_net_attrs net;
 	usbg_f_phonet_attrs phonet;
+	usbg_f_ffs_attrs ffs;
+	usbg_f_ms_attrs ms;
+	usbg_f_midi_attrs midi;
+	usbg_f_loopback_attrs loopback;
+} usbg_f_attrs;
+
+typedef enum {
+	USBG_F_ATTRS_SERIAL = 1,
+	USBG_F_ATTRS_NET,
+	USBG_F_ATTRS_PHONET,
+	USBG_F_ATTRS_FFS,
+	USBG_F_ATTRS_MS,
+	USBG_F_ATTRS_MIDI,
+	USBG_F_ATTRS_LOOPBACK,
+} usbg_f_attrs_type;
+
+typedef struct {
+	int attrs_type;
+} usbg_f_attrs_header;
+
+typedef struct {
+	usbg_f_attrs_header header;
+	usbg_f_attrs attrs;
 } usbg_function_attrs;
 
 /* Error codes */
@@ -195,17 +329,22 @@ typedef enum  {
 	USBG_ERROR_BUSY = -8,
 	USBG_ERROR_NOT_SUPPORTED = -9,
 	USBG_ERROR_PATH_TOO_LONG = -10,
+	USBG_ERROR_INVALID_FORMAT = -11,
+	USBG_ERROR_MISSING_TAG = -12,
+	USBG_ERROR_INVALID_TYPE = -13,
+	USBG_ERROR_INVALID_VALUE = -14,
+	USBG_ERROR_NOT_EMPTY = -15,
 	USBG_ERROR_OTHER_ERROR = -99
 } usbg_error;
 
-/*
+/**
  * @brief Get the error name as a constant string
  * @param e error code
  * @return Constant string with error name
  */
 extern const char *usbg_error_name(usbg_error e);
 
-/*
+/**
  * @brief Get the short description of error
  * @param e error code
  * @return Constant string with error description
@@ -215,20 +354,30 @@ extern const char *usbg_strerror(usbg_error e);
 /* Library init and cleanup */
 
 /**
- * @brief Initialize the libusbg library state
+ * @brief Initialize the libusbgx library state
  * @param configfs_path Path to the mounted configfs filesystem
- * @param Pointer to be filled with pointer to usbg_state
+ * @param state Pointer to be filled with pointer to usbg_state
  * @return 0 on success, usbg_error on error
  */
-extern int usbg_init(char *configfs_path, usbg_state **state);
+extern int usbg_init(const char *configfs_path, usbg_state **state);
 
 /**
- * @brief Clean up the libusbg library state
+ * @brief Clean up the libusbgx library state
  * @param s Pointer to state
  */
 extern void usbg_cleanup(usbg_state *s);
 
 /**
+ * @brief Get ConfigFS path
+ * @param s Pointer to state
+ * @return Path to configfs or NULL if error occurred
+ * @warning Returned buffer should not be edited!
+ * Returned string is valid as long as passed usbg_state is valid.
+ * For example path is valid until usbg_cleanup() call.
+ */
+extern const char *usbg_get_configfs_path(usbg_state *s);
+
+/**
  * @brief Get ConfigFS path length
  * @param s Pointer to state
  * @return Length of path or usbg_error if error occurred.
@@ -236,13 +385,13 @@ extern void usbg_cleanup(usbg_state *s);
 extern size_t usbg_get_configfs_path_len(usbg_state *s);
 
 /**
- * @brieg Get ConfigFS path
+ * @brief Copy ConfigFS path to buffer
  * @param s Pointer to state
  * @param buf Buffer where path should be copied
  * @param len Length of given buffer
  * @return 0 on success or usbg_error if error occurred.
  */
-extern int usbg_get_configfs_path(usbg_state *s, char *buf, size_t len);
+extern int usbg_cpy_configfs_path(usbg_state *s, char *buf, size_t len);
 
 /* USB gadget queries */
 
@@ -276,6 +425,67 @@ extern usbg_function *usbg_get_function(usbg_gadget *g,
  */
 extern usbg_config *usbg_get_config(usbg_gadget *g, int id, const char *label);
 
+/**
+ * @brief Get a udc by name
+ * @param s Pointer to state
+ * @param name Name of the udc
+ * @return Pointer to udc or NULL if a matching udc isn't found
+ */
+extern usbg_udc *usbg_get_udc(usbg_state *s, const char *name);
+
+/* USB gadget/config/function/binding removal */
+
+/**
+ * @brief Remove binding between configuration and function
+ * @details This function frees also the memory allocated for binding
+ * @param b Binding to be removed
+ * @return 0 on success, usbg_error if error occurred
+ */
+extern int usbg_rm_binding(usbg_binding *b);
+
+/**
+ * @brief Remove configuration
+ * @details This function frees also the memory allocated for configuration
+ * @param c Configuration to be removed
+ * @param opts Additional options for configuration removal.
+ * @return 0 on success, usbg_error if error occurred
+ */
+extern int usbg_rm_config(usbg_config *c, int opts);
+
+/**
+ * @brief Remove existing USB function
+ * @details This function frees also the memory allocated for function
+ * @param f Function to be removed
+ * @param opts Additional options for configuration removal.
+ * @return 0 on success, usbg_error if error occurred
+ */
+extern int usbg_rm_function(usbg_function *f, int opts);
+
+/**
+ * @brief Remove existing USB gadget
+ * @details This function frees also the memory allocated for gadget
+ * @param g Gadget to be removed
+ * @param opts Additional options for configuration removal.
+ * @return 0 on success, usbg_error if error occurred
+ */
+extern int usbg_rm_gadget(usbg_gadget *g, int opts);
+
+/**
+ * @brief Remove configuration strings for given language
+ * @param c Pointer to configuration
+ * @param lang Language of strings which should be deleted
+ * @return 0 on success, usbg_error if error occurred
+ */
+extern int usbg_rm_config_strs(usbg_config *c, int lang);
+
+/**
+ * @brief Remove gadget strings for given language
+ * @param g Pointer to gadget
+ * @param lang Language of strings which should be deleted
+ * @return 0 on success, usbg_error if error occurred
+ */
+extern int usbg_rm_gadget_strs(usbg_gadget *g, int lang);
+
 /* USB gadget allocation and configuration */
 
 /**
@@ -287,7 +497,7 @@ extern usbg_config *usbg_get_config(usbg_gadget *g, int id, const char *label);
  * @param g Pointer to be filled with pointer to gadget
  * @return 0 on success usbg_error if error occurred
  */
-extern int usbg_create_gadget_vid_pid(usbg_state *s, char *name,
+extern int usbg_create_gadget_vid_pid(usbg_state *s, const char *name,
 		uint16_t idVendor, uint16_t idProduct, usbg_gadget **g);
 
 /**
@@ -301,8 +511,60 @@ extern int usbg_create_gadget_vid_pid(usbg_state *s, char *name,
  * @note Given strings are assumed to be in US English
  * @return 0 on success usbg_error if error occurred
  */
-extern int usbg_create_gadget(usbg_state *s, char *name,
-		usbg_gadget_attrs *g_attrs, usbg_gadget_strs *g_strs, usbg_gadget **g);
+extern int usbg_create_gadget(usbg_state *s, const char *name,
+		const usbg_gadget_attrs *g_attrs, const usbg_gadget_strs *g_strs,
+			      usbg_gadget **g);
+
+/**
+ * @brief Get string representing selected gadget attribute
+ * @param attr code of selected attribute
+ * @return String suitable for given attribute or NULL if such
+ * string has not been found
+ */
+extern const char *usbg_get_gadget_attr_str(usbg_gadget_attr attr);
+
+/**
+ * @brief Lookup attr code based on its name
+ * @param name of attribute
+ * @return code of suitable attribute or usbg_error
+ */
+extern int usbg_lookup_gadget_attr(const char *name);
+
+/**
+ * @brief Lookup str code based on its name
+ * @param name of string
+ * @return code of suitable string or usbg_error
+ */
+extern int usbg_lookup_gadget_str(const char *name);
+
+/**
+ * @brief Get name of selected gadget string
+ * @param str Gadget string code
+ * @return Name of string associated with this code
+ */
+extern const char *usbg_get_gadget_str_name(usbg_gadget_str str);
+
+/**
+ * @brief Set selected attribute to value
+ * @param g Pointer to gadget
+ * @param attr Code of selected attribute
+ * @param val value to be set
+ * @return 0 on success, usbg_error otherwise
+ * @note val is of type int but value provided to this function should
+ * be suitable to place it in type dedicated for selected attr (uint16 or uint8)
+ */
+extern int usbg_set_gadget_attr(usbg_gadget *g, usbg_gadget_attr attr, int val);
+
+/**
+ * @brief Get value of selected attribute
+ * @param g Pointer to gadget
+ * @param attr Code of selected attribute
+ * @return Value of selected attribute (always above zero) or
+ * usbg_error if error occurred.
+ * @note User should use only lowest one or two bytes as attribute value
+ * depending on attribute size (see usbg_gadget_attrs for details).
+ */
+extern int usbg_get_gadget_attr(usbg_gadget *g, usbg_gadget_attr attr);
 
 /**
  * @brief Set the USB gadget attributes
@@ -311,7 +573,7 @@ extern int usbg_create_gadget(usbg_state *s, char *name,
  * @return 0 on success usbg_error if error occurred
  */
 extern int usbg_set_gadget_attrs(usbg_gadget *g,
-		usbg_gadget_attrs *g_attrs);
+		const usbg_gadget_attrs *g_attrs);
 
 /**
  * @brief Get the USB gadget strings
@@ -322,6 +584,16 @@ extern int usbg_set_gadget_attrs(usbg_gadget *g,
 extern int usbg_get_gadget_attrs(usbg_gadget *g, usbg_gadget_attrs *g_attrs);
 
 /**
+ * @brief Get gadget name
+ * @param g Pointer to gadget
+ * @return Gadget name or NULL if error occurred.
+ * @warning Returned buffer should not be edited!
+ * Returned string is valid as long as passed usbg_gadget is valid.
+ * For example gadget name is valid until someone remove gadget.
+ */
+extern const char *usbg_get_gadget_name(usbg_gadget *g);
+
+/**
  * @brief Get gadget name length
  * @param g Gadget which name length should be returned
  * @return Length of name string or usbg_error if error occurred.
@@ -329,13 +601,13 @@ extern int usbg_get_gadget_attrs(usbg_gadget *g, usbg_gadget_attrs *g_attrs);
 extern size_t usbg_get_gadget_name_len(usbg_gadget *g);
 
 /**
- * @brieg Get gadget name
- * @param b Pointer to gadget
+ * @brief Copy gadget name
+ * @param g Pointer to gadget
  * @param buf Buffer where name should be copied
  * @param len Length of given buffer
  * @return 0 on success or usbg_error if error occurred.
  */
-extern int usbg_get_gadget_name(usbg_gadget *g, char *buf, size_t len);
+extern int usbg_cpy_gadget_name(usbg_gadget *g, char *buf, size_t len);
 
 /**
  * @brief Set the USB gadget vendor id
@@ -410,21 +682,31 @@ extern int usbg_set_gadget_device_bcd_usb(usbg_gadget *g, uint16_t bcdUSB);
  * @brief Get the USB gadget strings
  * @param g Pointer to gadget
  * @param lang Language of strings
- * @param g_sttrs Structure to be filled
+ * @param g_strs Structure to be filled
  * @return 0 on success usbg_error if error occurred
  */
 extern int usbg_get_gadget_strs(usbg_gadget *g, int lang,
 		usbg_gadget_strs *g_strs);
 
 /**
+ * @brief Set selected string
+ * @param g Pointer to gadget
+ * @param str Code of selected string
+ * @param val value to be set
+ * @return 0 on success, usbg_error otherwise
+ */
+extern int usbg_set_gadget_str(usbg_gadget *g, usbg_gadget_str str, int lang,
+		const char *val);
+
+/**
  * @brief Set the USB gadget strings
  * @param g Pointer to gadget
  * @param lang USB language ID
- * @param g_sttrs Gadget attributes
+ * @param g_strs Gadget attributes
  * @return 0 on success usbg_error if error occurred
  */
 extern int usbg_set_gadget_strs(usbg_gadget *g, int lang,
-		usbg_gadget_strs *g_strs);
+		const usbg_gadget_strs *g_strs);
 
 /**
  * @brief Set the serial number for a gadget
@@ -433,7 +715,8 @@ extern int usbg_set_gadget_strs(usbg_gadget *g, int lang,
  * @param ser Serial number
  * @return 0 on success usbg_error if error occurred
  */
-extern int usbg_set_gadget_serial_number(usbg_gadget *g, int lang, char *ser);
+extern int usbg_set_gadget_serial_number(usbg_gadget *g, int lang,
+					 const char *ser);
 
 /**
  * @brief Set the manufacturer name for a gadget
@@ -442,7 +725,8 @@ extern int usbg_set_gadget_serial_number(usbg_gadget *g, int lang, char *ser);
  * @param mnf Manufacturer
  * @return 0 on success usbg_error if error occurred
  */
-extern int usbg_set_gadget_manufacturer(usbg_gadget *g, int lang, char *mnf);
+extern int usbg_set_gadget_manufacturer(usbg_gadget *g, int lang,
+					const char *mnf);
 
 /**
  * @brief Set the product name for a gadget
@@ -451,7 +735,8 @@ extern int usbg_set_gadget_manufacturer(usbg_gadget *g, int lang, char *mnf);
  * @param prd Product
  * @return 0 on success usbg_error if error occurred
  */
-extern int usbg_set_gadget_product(usbg_gadget *g, int lang, char *prd);
+extern int usbg_set_gadget_product(usbg_gadget *g, int lang,
+				   const char *prd);
 
 /* USB function allocation and configuration */
 
@@ -466,7 +751,18 @@ extern int usbg_set_gadget_product(usbg_gadget *g, int lang, char *prd);
  * @return 0 on success usbg_error if error occurred
  */
 extern int usbg_create_function(usbg_gadget *g, usbg_function_type type,
-		char *instance, usbg_function_attrs *f_attrs, usbg_function **f);
+		 const char *instance, const usbg_function_attrs *f_attrs,
+				usbg_function **f);
+
+/**
+ * @brief Get function instance name
+ * @param f Pointer to function
+ * @return instance name or NULL if error occurred.
+ * @warning Returned buffer should not be edited!
+ * Returned string is valid as long as passed usbg_function is valid.
+ * For example instance name is valid until someone remove this function.
+ */
+extern const char *usbg_get_function_instance(usbg_function *f);
 
 /**
  * @brief Get function instance name length
@@ -476,13 +772,13 @@ extern int usbg_create_function(usbg_gadget *g, usbg_function_type type,
 extern size_t usbg_get_function_instance_len(usbg_function *f);
 
 /**
- * @brief Get function instance name
+ * @brief Copy function instance name
  * @param f Pointer to function
  * @param buf Buffer where instance name should be copied
  * @param len Length of given buffer
  * @return 0 on success or usbg_error if error occurred.
  */
-extern int usbg_get_function_instance(usbg_function *f, char *buf, size_t len);
+extern int usbg_cpy_function_instance(usbg_function *f, char *buf, size_t len);
 
 /**
  * @brief Get function type as a string
@@ -491,6 +787,30 @@ extern int usbg_get_function_instance(usbg_function *f, char *buf, size_t len);
  */
 extern const char *usbg_get_function_type_str(usbg_function_type type);
 
+/**
+ * @brief Lookup function type suitable for given name
+ * @param name Name of function
+ * @return Function type enum or negative error code
+ */
+extern int usbg_lookup_function_type(const char *name);
+
+/**
+ * @brief Lookup attrs type for given type of function
+ * @param f_type type of functions
+ * @return Attributes type for this type of function
+ */
+extern int usbg_lookup_function_attrs_type(int f_type);
+
+/**
+ * @brief Cleanup content of function attributes
+ * @param f_attrs function attributes which should be cleaned up.
+ * @note This function should be called to free
+ * additional memory allocated by usbg_get_function_attrs().
+ * @warning None of attributes in passed structure should be
+ * accessed after returning from this function.
+ */
+extern void usbg_cleanup_function_attrs(usbg_function_attrs *f_attrs);
+
 /* USB configurations allocation and configuration */
 
 /**
@@ -505,7 +825,18 @@ extern const char *usbg_get_function_type_str(usbg_function_type type);
  * @return 0 on success usbg_error if error occurred
  */
 extern int usbg_create_config(usbg_gadget *g, int id, const char *label,
-		usbg_config_attrs *c_attrs, usbg_config_strs *c_strs, usbg_config **c);
+		const usbg_config_attrs *c_attrs, const usbg_config_strs *c_strs,
+		usbg_config **c);
+
+/**
+ * @brief Get config label
+ * @param c Pointer to config
+ * @return config label or NULL if error occurred.
+ * @warning Returned buffer should not be edited!
+ * Returned string is valid as long as passed usbg_config is valid.
+ * For example config label is valid until someone remove this function.
+ */
+extern const char *usbg_get_config_label(usbg_config *c);
 
 /**
  * @brief Get config label length
@@ -515,16 +846,16 @@ extern int usbg_create_config(usbg_gadget *g, int id, const char *label,
 extern size_t usbg_get_config_label_len(usbg_config *c);
 
 /**
- * @brieg Get config label
+ * @brief Copy config label
  * @param c Pointer to config
  * @param buf Buffer where label should be copied
  * @param len Length of given buffer
  * @return 0 on success or usbg_error if error occurred.
  */
-extern int usbg_get_config_label(usbg_config *c, char *buf, size_t len);
+extern int usbg_cpy_config_label(usbg_config *c, char *buf, size_t len);
 
 /**
- * @brieg Get config id
+ * @brief Get config id
  * @param c Pointer to config
  * @return Configuration id or usbg_error if error occurred.
  */
@@ -537,7 +868,7 @@ extern int usbg_get_config_id(usbg_config *c);
  * @return 0 on success or usbg_error if error occurred.
  */
 extern int usbg_set_config_attrs(usbg_config *c,
-		usbg_config_attrs *c_attrs);
+		const usbg_config_attrs *c_attrs);
 
 /**
  * @brief Get the USB configuration strings
@@ -567,7 +898,7 @@ extern int usbg_set_config_bm_attrs(usbg_config *c, int bmAttributes);
  * @brief Get the USB configuration strings
  * @param c Pointer to configuration
  * @param lang Language of strings
- * @param c_sttrs Structure to be filled
+ * @param c_strs Structure to be filled
  * @return 0 on success or usbg_error if error occurred.
  */
 extern int usbg_get_config_strs(usbg_config *c, int lang,
@@ -577,11 +908,11 @@ extern int usbg_get_config_strs(usbg_config *c, int lang,
  * @brief Set the USB configuration strings
  * @param c Pointer to configuration
  * @param lang USB language ID
- * @param c_sttrs Configuration strings
+ * @param c_strs Configuration strings
  * @return 0 on success, usbg_error on failure.
  */
 extern int usbg_set_config_strs(usbg_config *c, int lang,
-		usbg_config_strs *c_strs);
+		const usbg_config_strs *c_strs);
 
 /**
  * @brief Set the configuration string
@@ -590,7 +921,7 @@ extern int usbg_set_config_strs(usbg_config *c, int lang,
  * @param string Configuration description
  * @return 0 on success, usbg_error on failure.
  */
-extern int usbg_set_config_string(usbg_config *c, int lang, char *string);
+extern int usbg_set_config_string(usbg_config *c, int lang, const char *string);
 
 /**
  * @brief Add a function to a configuration
@@ -599,7 +930,8 @@ extern int usbg_set_config_string(usbg_config *c, int lang, char *string);
  * @param f Pointer to function
  * @return 0 on success, usbg_error on failure.
  */
-extern int usbg_add_config_function(usbg_config *c, char *name, usbg_function *f);
+extern int usbg_add_config_function(usbg_config *c, const char *name,
+				    usbg_function *f);
 
 /**
  * @brief Get target function of given binding
@@ -609,6 +941,16 @@ extern int usbg_add_config_function(usbg_config *c, char *name, usbg_function *f
 extern usbg_function *usbg_get_binding_target(usbg_binding *b);
 
 /**
+ * @brief Get binding name
+ * @param b Pointer to binding
+ * @return Binding name or NULL if error occurred.
+ * @warning Returned buffer should not be edited!
+ * Returned string is valid as long as passed usbg_binding is valid.
+ * For example binding name is valid until someone remove this binding.
+ */
+extern const char *usbg_get_binding_name(usbg_binding *b);
+
+/**
  * @brief Get binding name length
  * @param b Binding which name length should be returned
  * @return Length of name string or usbg_error if error occurred.
@@ -616,30 +958,24 @@ extern usbg_function *usbg_get_binding_target(usbg_binding *b);
 extern size_t usbg_get_binding_name_len(usbg_binding *b);
 
 /**
- * @brief Get binding name
+ * @brief Copy binding name
  * @param b Pointer to binding
  * @param buf Buffer where name should be copied
  * @param len Length of given buffer
  * @return 0 on success or usbg_error if error occurred.
  */
-extern int usbg_get_binding_name(usbg_binding *b, char *buf, size_t len);
+extern int usbg_cpy_binding_name(usbg_binding *b, char *buf, size_t len);
 
 /* USB gadget setup and teardown */
 
 /**
- * @brief Get a list of UDC devices on the system
- * @param udc_list Pointer to pointer to dirent pointer
- * @return Number of UDC devices on success, usbg_error on failure
- */
-extern int usbg_get_udcs(struct dirent ***udc_list);
-
-/**
  * @brief Enable a USB gadget device
  * @param g Pointer to gadget
- * @param udc Name of UDC to enable gadget
+ * @param udc where gadget should be assigned.
+ *  If NULL, default one (first) is used.
  * @return 0 on success or usbg_error if error occurred.
  */
-extern int usbg_enable_gadget(usbg_gadget *g, char *udc);
+extern int usbg_enable_gadget(usbg_gadget *g, usbg_udc *udc);
 
 /**
  * @brief Disable a USB gadget device
@@ -649,6 +985,16 @@ extern int usbg_enable_gadget(usbg_gadget *g, char *udc);
 extern int usbg_disable_gadget(usbg_gadget *g);
 
 /**
+ * @brief Get name of udc
+ * @param u Pointer to udc
+ * @return UDC name or NULL if error occurred.
+ * @warning Returned buffer should not be edited!
+ * Returned string is valid as long as passed usbg_state is valid.
+ * For example UDC name is valid until usbg_cleanup().
+ */
+extern const char *usbg_get_udc_name(usbg_udc *u);
+
+/**
  * @brief Get gadget name length
  * @param g Gadget which name length should be returned
  * @return Length of name string or usbg_error if error occurred.
@@ -657,14 +1003,27 @@ extern int usbg_disable_gadget(usbg_gadget *g);
 extern size_t usbg_get_gadget_udc_len(usbg_gadget *g);
 
 /**
- * @brieg Get name of udc to which gadget is binded
- * @param b Pointer to gadget
+ * @brief Copy name of udc
+ * @param u Pointer to udc
  * @param buf Buffer where udc name should be copied
  * @param len Length of given buffer
  * @return 0 on success or usbg_error if error occurred.
- * @note If gadget isn't enabled on any udc returned string is empty.
  */
-extern int usbg_get_gadget_udc(usbg_gadget *g, char *buf, size_t len);
+extern int usbg_cpy_udc_name(usbg_udc *u, char *buf, size_t len);
+
+/**
+ * @brief Get udc to which gadget is bound
+ * @param g Pointer to gadget
+ * @return Pointer to UDC or NULL if gadget is not enabled
+ */
+extern usbg_udc *usbg_get_gadget_udc(usbg_gadget *g);
+
+/**
+ * @brief Get gadget which is attached to this UDC
+ * @param u Pointer to udc
+ * @return Pointer to gadget or NULL if UDC is free
+ */
+extern usbg_gadget *usbg_get_udc_gadget(usbg_udc *u);
 
 /*
  * USB function-specific attribute configuration
@@ -693,7 +1052,8 @@ extern int usbg_get_function_attrs(usbg_function *f,
  * @param f_attrs Attributes to be set
  * @return 0 on success, usbg_error if error occurred
  */
-extern int usbg_set_function_attrs(usbg_function *f, usbg_function_attrs *f_attrs);
+extern int usbg_set_function_attrs(usbg_function *f,
+		const usbg_function_attrs *f_attrs);
 
 /**
  * @brief Set USB function network device address
@@ -756,6 +1116,15 @@ extern int usbg_set_net_qmult(usbg_function *f, int qmult);
 	b = usbg_get_next_binding(b))
 
 /**
+ * @def usbg_for_each_udc(b, c)
+ * Iterates over each udc
+ */
+#define usbg_for_each_udc(u, s)	\
+	for (u = usbg_get_first_udc(s); \
+	u != NULL; \
+	u = usbg_get_next_udc(u))
+
+/**
  * @brief Get first gadget in gadget list
  * @param s State of library
  * @return Pointer to gadget or NULL if list is empty.
@@ -781,41 +1150,164 @@ extern usbg_config *usbg_get_first_config(usbg_gadget *g);
 
 /**
  * @brief Get first binding in binding list
- * @param C Pointer to configuration
+ * @param c Pointer to configuration
  * @return Pointer to binding or NULL if list is empty.
  * @note Bindings are sorted in strings (name) order
  */
 extern usbg_binding *usbg_get_first_binding(usbg_config *c);
 
 /**
+ * @brief Get first udc in udc list
+ * @param s State of library
+ * @return Pointer to udc or NULL if list is empty.
+ * @note UDCs are sorted in strings (name) order
+ */
+extern usbg_udc *usbg_get_first_udc(usbg_state *s);
+
+/**
  * @brief Get the next gadget on a list.
- * @pram g Pointer to current gadget
+ * @param g Pointer to current gadget
  * @return Next gadget or NULL if end of list.
  */
 extern usbg_gadget *usbg_get_next_gadget(usbg_gadget *g);
 
 /**
  * @brief Get the next function on a list.
- * @pram g Pointer to current function
+ * @param f Pointer to current function
  * @return Next function or NULL if end of list.
  */
 extern usbg_function *usbg_get_next_function(usbg_function *f);
 
 /**
  * @brief Get the next config on a list.
- * @pram g Pointer to current config
+ * @param c Pointer to current config
  * @return Next config or NULL if end of list.
  */
 extern usbg_config *usbg_get_next_config(usbg_config *c);
 
 /**
  * @brief Get the next binding on a list.
- * @pram g Pointer to current binding
+ * @param b Pointer to current binding
  * @return Next binding or NULL if end of list.
  */
 extern usbg_binding *usbg_get_next_binding(usbg_binding *b);
 
 /**
+ * @brief Get the next udc on a list.
+ * @param u Pointer to current udc
+ * @return Next udc or NULL if end of list.
+ */
+extern usbg_udc *usbg_get_next_udc(usbg_udc *u);
+
+/* Import / Export API */
+
+/**
+ * @brief Exports usb function to file
+ * @param f Pointer to function to be exported
+ * @param stream where function should be saved
+ * @return 0 on success, usbg_error otherwise
+ */
+extern int usbg_export_function(usbg_function *f, FILE *stream);
+
+/**
+ * @brief Exports configuration to file
+ * @param c Pointer to configuration to be exported
+ * @param stream where configuration should be saved
+ * @return 0 on success, usbg_error otherwise
+ */
+extern int usbg_export_config(usbg_config *c, FILE *stream);
+
+/**
+ * @brief Exports whole gadget to file
+ * @param g Pointer to gadget to be exported
+ * @param stream where gadget should be saved
+ * @return 0 on success, usbg_error otherwise
+ */
+extern int usbg_export_gadget(usbg_gadget *g, FILE *stream);
+
+/**
+ * @brief Imports usb function from file and adds it to given gadget
+ * @param g Gadget where function should be placed
+ * @param stream from which function should be imported
+ * @param instance name which should be used for new function
+ * @param f place for pointer to imported function
+ * if NULL this param will be ignored.
+ * @return 0 on success, usbg_error otherwise
+ */
+extern int usbg_import_function(usbg_gadget *g, FILE *stream,
+				const char *instance, usbg_function **f);
+
+/**
+ * @brief Imports usb configuration from file and adds it to given gadget
+ * @param g Gadget where configuration should be placed
+ * @param stream from which configuration should be imported
+ * @param id which should be used for new configuration
+ * @param c place for pointer to imported configuration
+ * if NULL this param will be ignored.
+ * @return 0 on success, usbg_error otherwise
+ */
+extern int usbg_import_config(usbg_gadget *g, FILE *stream, int id,
+				usbg_config **c);
+/**
+ * @brief Imports usb gadget from file
+ * @param s current state of library
+ * @param stream from which gadget should be imported
+ * @param name which should be used for new gadget
+ * @param g place for pointer to imported gadget
+ * if NULL this param will be ignored.
+ * @return 0 on success, usbg_error otherwise
+ */
+extern int usbg_import_gadget(usbg_state *s, FILE *stream,
+			      const char *name, usbg_gadget **g);
+
+/**
+ * @brief Get text of error which occurred during last function import
+ * @param g gadget where function import error occurred
+ * @return Text of error or NULL if no error data
+ */
+extern const char *usbg_get_func_import_error_text(usbg_gadget *g);
+
+/**
+ * @brief Get line number where function import error occurred
+ * @param g gadget where function import error occurred
+ * @return line number or value below 0 if no error data
+ */
+extern int usbg_get_func_import_error_line(usbg_gadget *g);
+
+/**
+ * @brief Get text of error which occurred during last config import
+ * @param g gadget where config import error occurred
+ * @return Text of error or NULL if no error data
+ */
+extern const char *usbg_get_config_import_error_text(usbg_gadget *g);
+
+/**
+ * @brief Get line number where config import error occurred
+ * @param g gadget where config import error occurred
+ * @return line number or value below 0 if no error data
+ */
+extern int usbg_get_config_import_error_line(usbg_gadget *g);
+
+/**
+ * @brief Get text of error which occurred during last gadget import
+ * @param s where gadget import error occurred
+ * @return Text of error or NULL if no error data
+ */
+extern const char *usbg_get_gadget_import_error_text(usbg_state *s);
+
+/**
+ * @brief Get line number where gadget import error occurred
+ * @param s where gadget import error occurred
+ * @return line number or value below 0 if no error data
+ */
+extern int usbg_get_gadget_import_error_line(usbg_state *s);
+
+/**
  * @}
  */
+
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* __USBG_H__ */
diff --git a/include/usbg/usbg_internal.h b/include/usbg/usbg_internal.h
new file mode 100644
index 0000000..30d3fcf
--- /dev/null
+++ b/include/usbg/usbg_internal.h
@@ -0,0 +1,174 @@
+/*
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ */
+
+#ifndef USBG_INTERNAL_H
+#define USBG_INTERNAL_H
+
+#include <sys/queue.h>
+#include <string.h>
+#include <usbg/usbg.h>
+
+#ifdef HAS_LIBCONFIG
+#include <libconfig.h>
+#else
+	typedef struct _should_not_be_used config_t;
+	void config_destroy(config_t *config);
+#endif
+
+/**
+ * @file include/usbg/usbg_internal.h
+ */
+
+#ifndef offsetof
+#define offsetof(type, member)  __builtin_offsetof (type, member)
+#endif /* offsetof */
+
+#ifndef container_of
+#define container_of(ptr, type, field) ({                               \
+                        const typeof(((type *)0)->field) *member = (ptr); \
+                        (type *)( (char *)member - offsetof(type, field) ); \
+                })
+#endif /* container_of */
+
+struct usbg_state
+{
+	char *path;
+	char *configfs_path;
+
+	TAILQ_HEAD(ghead, usbg_gadget) gadgets;
+	TAILQ_HEAD(uhead, usbg_udc) udcs;
+	config_t *last_failed_import;
+};
+
+struct usbg_gadget
+{
+	char *name;
+	char *path;
+
+	TAILQ_ENTRY(usbg_gadget) gnode;
+	TAILQ_HEAD(chead, usbg_config) configs;
+	TAILQ_HEAD(fhead, usbg_function) functions;
+	usbg_state *parent;
+	config_t *last_failed_import;
+	usbg_udc *udc;
+};
+
+struct usbg_config
+{
+	TAILQ_ENTRY(usbg_config) cnode;
+	TAILQ_HEAD(bhead, usbg_binding) bindings;
+	usbg_gadget *parent;
+
+	char *name;
+	char *path;
+	char *label;
+	int id;
+};
+
+typedef int (*usbg_rm_function_callback)(usbg_function *, int);
+
+struct usbg_function
+{
+	TAILQ_ENTRY(usbg_function) fnode;
+	usbg_gadget *parent;
+
+	char *name;
+	char *path;
+	char *instance;
+	/* Only for internal library usage */
+	char *label;
+	usbg_function_type type;
+	usbg_rm_function_callback rm_callback;
+};
+
+struct usbg_binding
+{
+	TAILQ_ENTRY(usbg_binding) bnode;
+	usbg_config *parent;
+	usbg_function *target;
+
+	char *name;
+	char *path;
+};
+
+struct usbg_udc
+{
+	TAILQ_ENTRY(usbg_udc) unode;
+	usbg_state *parent;
+	usbg_gadget *gadget;
+
+	char *name;
+};
+
+#define ARRAY_SIZE(array) (sizeof(array)/sizeof(*array))
+
+#define ARRAY_SIZE_SENTINEL(array, size)				\
+	static void __attribute__ ((unused)) array##_size_sentinel()				\
+	{								\
+		char array##_smaller_than_expected[			\
+			(int)(ARRAY_SIZE(array) - size)]		\
+			__attribute__ ((unused));			\
+									\
+		char array##_larger_than_expected[			\
+			(int)(size - ARRAY_SIZE(array))]		\
+			__attribute__ ((unused));			\
+	}
+
+#define ERROR(msg, ...) do {\
+                        fprintf(stderr, "%s()  "msg" \n", \
+                                __func__, ##__VA_ARGS__);\
+                        fflush(stderr);\
+                    } while (0)
+
+#define ERRORNO(msg, ...) do {\
+                        fprintf(stderr, "%s()  %s: "msg" \n", \
+                                __func__, strerror(errno), ##__VA_ARGS__);\
+                        fflush(stderr);\
+                    } while (0)
+
+/* Insert in string order */
+#define INSERT_TAILQ_STRING_ORDER(HeadPtr, HeadType, NameField, ToInsert, NodeField) \
+	do { \
+		if (TAILQ_EMPTY((HeadPtr)) || \
+			(strcmp((ToInsert)->NameField, TAILQ_FIRST((HeadPtr))->NameField) < 0)) \
+			TAILQ_INSERT_HEAD((HeadPtr), (ToInsert), NodeField); \
+		else if (strcmp((ToInsert)->NameField, TAILQ_LAST((HeadPtr), HeadType)->NameField) > 0) \
+			TAILQ_INSERT_TAIL((HeadPtr), (ToInsert), NodeField); \
+		else { \
+			typeof(ToInsert) _cur; \
+			TAILQ_FOREACH(_cur, (HeadPtr), NodeField) { \
+				if (strcmp((ToInsert)->NameField, _cur->NameField) > 0) \
+					continue; \
+				TAILQ_INSERT_BEFORE(_cur, (ToInsert), NodeField); \
+			} \
+		} \
+	} while (0)
+
+#define STRINGS_DIR "strings"
+#define CONFIGS_DIR "configs"
+#define FUNCTIONS_DIR "functions"
+#define GADGETS_DIR "usb_gadget"
+
+static inline int file_select(const struct dirent *dent)
+{
+	if ((strcmp(dent->d_name, ".") == 0) || (strcmp(dent->d_name, "..") == 0))
+		return 0;
+	else
+		return 1;
+}
+
+int usbg_translate_error(int error);
+
+char *usbg_ether_ntoa_r(const struct ether_addr *addr, char *buf);
+
+#endif /* USBG_INTERNAL_H */
+