function: add support for usb9pfs

Makefile.am

@@ -14,7 +14,7 @@ EXTRA_DIST = doxygen.cfg
 library_includedir=$(includedir)/usbg
 library_include_HEADERS = include/usbg/usbg.h include/usbg/usbg_version.h
 function_includedir=$(includedir)/usbg/function
-function_include_HEADERS = include/usbg/function/ffs.h include/usbg/function/loopback.h include/usbg/function/midi.h include/usbg/function/ms.h include/usbg/function/net.h include/usbg/function/phonet.h include/usbg/function/serial.h include/usbg/function/hid.h include/usbg/function/uac2.h include/usbg/function/uvc.h include/usbg/function/printer.h
+function_include_HEADERS = include/usbg/function/ffs.h include/usbg/function/loopback.h include/usbg/function/midi.h include/usbg/function/ms.h include/usbg/function/net.h include/usbg/function/phonet.h include/usbg/function/serial.h include/usbg/function/hid.h include/usbg/function/uac2.h include/usbg/function/uvc.h include/usbg/function/printer.h include/usbg/function/9pfs.h
 pkgconfigdir = $(libdir)/pkgconfig
 pkgconfig_DATA = libusbgx.pc
 cmakeconfigdir = $(libdir)/cmake/LibUsbgx

include/usbg/function/9pfs.h

@@ -0,0 +1,71 @@
+/*
+ * Copyright (C) 2024 Pengutronix
+ *
+ * Michael Grzeschik <m.grzeschik@pengutronix.de>
+ *
+ * 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_FUNCTION_FS__
+#define USBG_FUNCTION_FS__
+
+#include <usbg/usbg.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct usbg_f_9pfs;
+typedef struct usbg_f_9pfs usbg_f_9pfs;
+
+/**
+ * @brief Convert from generic function to 9pfs
+ * @param[in] f function to be converted to 9pfs.
+ *         Function should be of type function fs.
+ * @return Converted function or NULL if function hasn't suitable type
+ */
+usbg_f_9pfs *usbg_to_9pfs(usbg_function *f);
+
+/**
+ * @brief Convert form 9pfs to a generic one
+ * @param[in] 9pfs function to be converted to generic one
+ * @return Generic usbg function
+ */
+usbg_function *usbg_from_9pfs(usbg_f_9pfs *p9fs);
+
+/**
+ * @brief Get the device name which should be used while mounting
+ *         9pfs instace into newly allocated storage
+ * @param[in] pf Pointer to net function
+ * @param[out] dev_name Newly allocated string containing device name
+ * @return 0 on success usbg_error if error occurred.
+ * @note returned dev_name should be free() by caller
+ */
+int usbg_f_9pfs_get_dev_name(usbg_f_9pfs *p9fs, char **dev_name);
+
+/**
+ * @brief Get the device name which should be used while mounting
+ *         9pfs instace into user buffer
+ * @param[in] pf Pointer to fs function
+ * @param[out] buf Place where ifname should be stored
+ * @param[in] len Size of buffer
+ * @return Number of bytes placed into buf (excluding '\0') or the number of
+ *         characters which would have been written to the buffer if enough
+ *         space had been available. (just like snprintf() family). This may
+ *         also return negative error code from usbg_error.
+ */
+int usbg_f_9pfs_get_dev_name_s(usbg_f_9pfs *p9fs, char *buf, int len);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* USBG_FUNCTION_FS__ */

include/usbg/usbg.h

@@ -221,6 +221,7 @@ typedef enum
 	USBG_F_UAC2,
 	USBG_F_UVC,
 	USBG_F_PRINTER,
+	USBG_F_9PFS,
 	USBG_FUNCTION_TYPE_MAX,
 } usbg_function_type;
 

src/Makefile.am

@@ -1,6 +1,6 @@
 AUTOMAKE_OPTIONS = std-options subdir-objects
 lib_LTLIBRARIES = libusbgx.la
-libusbgx_la_SOURCES = usbg.c usbg_error.c usbg_common.c function/ether.c function/ffs.c function/midi.c function/ms.c function/phonet.c function/serial.c function/loopback.c function/hid.c function/uac2.c function/uvc.c function/printer.c
+libusbgx_la_SOURCES = usbg.c usbg_error.c usbg_common.c function/ether.c function/ffs.c function/midi.c function/ms.c function/phonet.c function/serial.c function/loopback.c function/hid.c function/uac2.c function/uvc.c function/printer.c function/9pfs.c
 if TEST_GADGET_SCHEMES
 libusbgx_la_SOURCES += usbg_schemes_libconfig.c usbg_common_libconfig.c
 else

src/function/9pfs.c

@@ -0,0 +1,107 @@
+/*
+ * Copyright (C) 2024 Pengutronix
+ *
+ * Michael Grzeschik <m.grzeschik@pengutronix.de>
+ *
+ * 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.
+ */
+
+#include "usbg/usbg.h"
+#include "usbg/usbg_internal.h"
+#include "usbg/function/9pfs.h"
+
+#include <malloc.h>
+#ifdef HAS_GADGET_SCHEMES
+#include <libconfig.h>
+#endif
+
+struct usbg_f_9pfs {
+	struct usbg_function func;
+};
+
+GENERIC_ALLOC_INST(p9fs, struct usbg_f_9pfs, func);
+
+GENERIC_FREE_INST(p9fs, struct usbg_f_9pfs, func);
+
+static int p9fs_set_attrs(struct usbg_function *f, void *f_attrs)
+{
+	const char *dev_name = *(const char **)f_attrs;
+
+	return dev_name && dev_name[0] ? USBG_ERROR_INVALID_PARAM
+		: USBG_SUCCESS;
+}
+
+static int p9fs_get_attrs(struct usbg_function *f, void *f_attrs)
+{
+	return usbg_f_9pfs_get_dev_name(usbg_to_9pfs(f), f_attrs);
+}
+
+static void p9fs_cleanup_attrs(struct usbg_function *f, void *f_attrs)
+{
+	free(*(char **)f_attrs);
+}
+
+static int p9fs_libconfig_import(struct usbg_function *f,
+				  config_setting_t *root)
+{
+	return USBG_SUCCESS;
+}
+
+static int p9fs_libconfig_export(struct usbg_function *f,
+				  config_setting_t *root)
+{
+	return USBG_SUCCESS;
+}
+
+struct usbg_function_type usbg_f_type_9pfs = {
+	.name = "usb9pfs",
+	.alloc_inst = p9fs_alloc_inst,
+	.free_inst = p9fs_free_inst,
+	.set_attrs = p9fs_set_attrs,
+	.get_attrs = p9fs_get_attrs,
+	.cleanup_attrs = p9fs_cleanup_attrs,
+	.import = p9fs_libconfig_import,
+	.export = p9fs_libconfig_export,
+};
+
+/* API implementation */
+
+usbg_f_9pfs *usbg_to_9pfs(usbg_function *f)
+{
+	return f->ops == &usbg_f_type_9pfs ?
+		container_of(f, struct usbg_f_9pfs, func) : NULL;
+}
+
+usbg_function *usbg_from_9pfs(usbg_f_9pfs *p9fs)
+{
+	return &p9fs->func;
+}
+
+int usbg_f_9pfs_get_dev_name(usbg_f_9pfs *p9fs, char **dev_name)
+{
+	if (!p9fs || !dev_name)
+		return USBG_ERROR_INVALID_PARAM;
+
+	*dev_name = strdup(p9fs->func.instance);
+	if (!*dev_name)
+		return USBG_ERROR_NO_MEM;
+
+	return 0;
+}
+
+int usbg_f_9pfs_get_dev_name_s(usbg_f_9pfs *p9fs, char *buf, int len)
+{
+	if (!p9fs || !buf)
+		return USBG_ERROR_INVALID_PARAM;
+
+	return snprintf(buf, len, "%s", p9fs->func.instance);
+}
+

src/usbg.c

@@ -54,6 +54,7 @@ extern struct usbg_function_type usbg_f_type_hid;
 extern struct usbg_function_type usbg_f_type_uac2;
 extern struct usbg_function_type usbg_f_type_uvc;
 extern struct usbg_function_type usbg_f_type_printer;
+extern struct usbg_function_type usbg_f_type_9pfs;
 
 /**
  * @var function_types
@@ -77,6 +78,7 @@ struct usbg_function_type* function_types[] = {
 	[USBG_F_UAC2] = &usbg_f_type_uac2,
 	[USBG_F_UVC] = &usbg_f_type_uvc,
 	[USBG_F_PRINTER] = &usbg_f_type_printer,
+	[USBG_F_9PFS] = &usbg_f_type_9pfs,
 };
 
 ARRAY_SIZE_SENTINEL(function_types, USBG_FUNCTION_TYPE_MAX);