drivers/staging/usbip/userspace/libsrc/stub_driver.c - maze/linux - Git at Google

 /*
  * Copyright (C) 2005-2007 Takahiro Hirofuchi
  */

 #include <sys/types.h>
 #include <sys/stat.h>
 #include <unistd.h>

 #include "usbip.h"

 /* kernel module name */
 static const char *usbip_stub_driver_name = "usbip-host";


 struct usbip_stub_driver *stub_driver;

 static struct sysfs_driver *open_sysfs_stub_driver(void)
 {
 	int ret;

 	char sysfs_mntpath[SYSFS_PATH_MAX];
 	char stub_driver_path[SYSFS_PATH_MAX];
 	struct sysfs_driver *stub_driver;


 	ret = sysfs_get_mnt_path(sysfs_mntpath, SYSFS_PATH_MAX);
 	if (ret < 0) {
 		err("sysfs must be mounted");
 		return NULL;
 	}

 	snprintf(stub_driver_path, SYSFS_PATH_MAX, "%s/%s/usb/%s/%s",
 			sysfs_mntpath, SYSFS_BUS_NAME, SYSFS_DRIVERS_NAME,
 			usbip_stub_driver_name);

 	stub_driver = sysfs_open_driver_path(stub_driver_path);
 	if (!stub_driver) {
 		err("usbip-core.ko and usbip-host.ko must be loaded");
 		return NULL;
 	}

 	return stub_driver;
 }


 #define SYSFS_OPEN_RETRIES 100

 /* only the first interface value is true! */
 static int32_t read_attr_usbip_status(struct usb_device *udev)
 {
 	char attrpath[SYSFS_PATH_MAX];
 	struct sysfs_attribute *attr;
 	int value = 0;
 	int  ret;
 	struct stat s;
 	int retries = SYSFS_OPEN_RETRIES;

 	/* This access is racy!
 	 *
 	 * Just after detach, our driver removes the sysfs
 	 * files and recreates them.
 	 *
 	 * We may try and fail to open the usbip_status of
 	 * an exported device in the (short) window where
 	 * it has been removed and not yet recreated.
 	 *
 	 * This is a bug in the interface. Nothing we can do
 	 * except work around it here by polling for the sysfs
 	 * usbip_status to reappear.
 	 */

 	snprintf(attrpath, SYSFS_PATH_MAX, "%s/%s:%d.%d/usbip_status",
 			udev->path, udev->busid,
 			udev->bConfigurationValue,
 			0);

 	while (retries > 0) {
 		if (stat(attrpath, &s) == 0)
 			break;

 		if (errno != ENOENT) {
 			err("error stat'ing %s", attrpath);
 			return -1;
 		}

 		usleep(10000); /* 10ms */
 		retries--;
 	}

 	if (retries == 0)
 		err("usbip_status not ready after %d retries",
 			SYSFS_OPEN_RETRIES);
 	else if (retries < SYSFS_OPEN_RETRIES)
 		info("warning: usbip_status ready after %d retries",
 			 SYSFS_OPEN_RETRIES - retries);

 	attr = sysfs_open_attribute(attrpath);
 	if (!attr) {
 		err("open %s", attrpath);
 		return -1;
 	}

 	ret = sysfs_read_attribute(attr);
 	if (ret) {
 		err("read %s", attrpath);
 		sysfs_close_attribute(attr);
 		return -1;
 	}

 	value = atoi(attr->value);

 	sysfs_close_attribute(attr);

 	return value;
 }


 static void usbip_exported_device_delete(void *dev)
 {
 	struct usbip_exported_device *edev =
 		(struct usbip_exported_device *) dev;

 	sysfs_close_device(edev->sudev);
 	free(dev);
 }


 static struct usbip_exported_device *usbip_exported_device_new(char *sdevpath)
 {
 	struct usbip_exported_device *edev = NULL;

 	edev = (struct usbip_exported_device *) calloc(1, sizeof(*edev));
 	if (!edev) {
 		err("alloc device");
 		return NULL;
 	}

 	edev->sudev = sysfs_open_device_path(sdevpath);
 	if (!edev->sudev) {
 		err("open %s", sdevpath);
 		goto err;
 	}

 	read_usb_device(edev->sudev, &edev->udev);

 	edev->status = read_attr_usbip_status(&edev->udev);
 	if (edev->status < 0)
 		goto err;

 	/* reallocate buffer to include usb interface data */
 	size_t size = sizeof(*edev) + edev->udev.bNumInterfaces * sizeof(struct usb_interface);
 	edev = (struct usbip_exported_device *) realloc(edev, size);
 	if (!edev) {
 		err("alloc device");
 		goto err;
 	}

 	for (int i=0; i < edev->udev.bNumInterfaces; i++)
 		read_usb_interface(&edev->udev, i, &edev->uinf[i]);

 	return edev;

 err:
 	if (edev && edev->sudev)
 		sysfs_close_device(edev->sudev);
 	if (edev)
 		free(edev);
 	return NULL;
 }


 static int check_new(struct dlist *dlist, struct sysfs_device *target)
 {
 	struct sysfs_device *dev;

 	dlist_for_each_data(dlist, dev, struct sysfs_device) {
 		if (!strncmp(dev->bus_id, target->bus_id, SYSFS_BUS_ID_SIZE))
 			/* found. not new */
 			return 0;
 	}

 	return 1;
 }

 static void delete_nothing(void *dev __attribute__((unused)))
 {
 	/* do not delete anything. but, its container will be deleted. */
 }

 static int refresh_exported_devices(void)
 {
 	struct sysfs_device	*suinf;  /* sysfs_device of usb_interface */
 	struct dlist		*suinf_list;

 	struct sysfs_device	*sudev;  /* sysfs_device of usb_device */
 	struct dlist		*sudev_list;


 	sudev_list = dlist_new_with_delete(sizeof(struct sysfs_device), delete_nothing);

 	suinf_list = sysfs_get_driver_devices(stub_driver->sysfs_driver);
 	if (!suinf_list) {
 		printf("Bind usbip-host.ko to a usb device to be exportable!\n");
 		goto bye;
 	}

 	/* collect unique USB devices (not interfaces) */
 	dlist_for_each_data(suinf_list, suinf, struct sysfs_device) {

 		/* get usb device of this usb interface */
 		sudev = sysfs_get_device_parent(suinf);
 		if (!sudev) {
 			err("get parent dev of %s", suinf->name);
 			continue;
 		}

 		if (check_new(sudev_list, sudev)) {
 			dlist_unshift(sudev_list, sudev);
 		}
 	}

 	dlist_for_each_data(sudev_list, sudev, struct sysfs_device) {
 		struct usbip_exported_device *edev;

 		edev = usbip_exported_device_new(sudev->path);
 		if (!edev) {
 			err("usbip_exported_device new");
 			continue;
 		}

 		dlist_unshift(stub_driver->edev_list, (void *) edev);
 		stub_driver->ndevs++;
 	}


 	dlist_destroy(sudev_list);

 bye:

 	return 0;
 }

 int usbip_stub_refresh_device_list(void)
 {
 	int ret;

 	if (stub_driver->edev_list)
 		dlist_destroy(stub_driver->edev_list);

 	stub_driver->ndevs = 0;

 	stub_driver->edev_list = dlist_new_with_delete(sizeof(struct usbip_exported_device),
 			usbip_exported_device_delete);
 	if (!stub_driver->edev_list) {
 		err("alloc dlist");
 		return -1;
 	}

 	ret = refresh_exported_devices();
 	if (ret < 0)
 		return ret;

 	return 0;
 }

 int usbip_stub_driver_open(void)
 {
 	int ret;


 	stub_driver = (struct usbip_stub_driver *) calloc(1, sizeof(*stub_driver));
 	if (!stub_driver) {
 		err("alloc stub_driver");
 		return -1;
 	}

 	stub_driver->ndevs = 0;

 	stub_driver->edev_list = dlist_new_with_delete(sizeof(struct usbip_exported_device),
 			usbip_exported_device_delete);
 	if (!stub_driver->edev_list) {
 		err("alloc dlist");
 		goto err;
 	}

 	stub_driver->sysfs_driver = open_sysfs_stub_driver();
 	if (!stub_driver->sysfs_driver)
 		goto err;

 	ret = refresh_exported_devices();
 	if (ret < 0)
 		goto err;

 	return 0;


 err:
 	if (stub_driver->sysfs_driver)
 		sysfs_close_driver(stub_driver->sysfs_driver);
 	if (stub_driver->edev_list)
 		dlist_destroy(stub_driver->edev_list);
 	free(stub_driver);

 	stub_driver = NULL;
 	return -1;
 }


 void usbip_stub_driver_close(void)
 {
 	if (!stub_driver)
 		return;

 	if (stub_driver->edev_list)
 		dlist_destroy(stub_driver->edev_list);
 	if (stub_driver->sysfs_driver)
 		sysfs_close_driver(stub_driver->sysfs_driver);
 	free(stub_driver);

 	stub_driver = NULL;
 }

 int usbip_stub_export_device(struct usbip_exported_device *edev, int sockfd)
 {
 	char attrpath[SYSFS_PATH_MAX];
 	struct sysfs_attribute *attr;
 	char sockfd_buff[30];
 	int ret;


 	if (edev->status != SDEV_ST_AVAILABLE) {
 		info("device not available, %s", edev->udev.busid);
 		switch( edev->status ) {
 			case SDEV_ST_ERROR:
 				info("     status SDEV_ST_ERROR");
 				break;
 			case SDEV_ST_USED:
 				info("     status SDEV_ST_USED");
 				break;
 			default:
 				info("     status unknown: 0x%x", edev->status);
 		}
 		return -1;
 	}

 	/* only the first interface is true */
 	snprintf(attrpath, sizeof(attrpath), "%s/%s:%d.%d/%s",
 			edev->udev.path,
 			edev->udev.busid,
 			edev->udev.bConfigurationValue, 0,
 			"usbip_sockfd");

 	attr = sysfs_open_attribute(attrpath);
 	if (!attr) {
 		err("open %s", attrpath);
 		return -1;
 	}

 	snprintf(sockfd_buff, sizeof(sockfd_buff), "%d\n", sockfd);

 	dbg("write: %s", sockfd_buff);

 	ret = sysfs_write_attribute(attr, sockfd_buff, strlen(sockfd_buff));
 	if (ret < 0) {
 		err("write sockfd %s to %s", sockfd_buff, attrpath);
 		goto err_write_sockfd;
 	}

 	info("connect %s", edev->udev.busid);

 err_write_sockfd:
 	sysfs_close_attribute(attr);

 	return ret;
 }

 struct usbip_exported_device *usbip_stub_get_device(int num)
 {
 	struct usbip_exported_device *edev;
 	struct dlist		*dlist = stub_driver->edev_list;
 	int count = 0;

 	dlist_for_each_data(dlist, edev, struct usbip_exported_device) {
 		if (num == count)
 			return edev;
 		else
 			count++ ;
 	}

 	return NULL;
 }
	/*
	* Copyright (C) 2005-2007 Takahiro Hirofuchi
	*/

	#include <sys/types.h>
	#include <sys/stat.h>
	#include <unistd.h>

	#include "usbip.h"

	/* kernel module name */
	static const char *usbip_stub_driver_name = "usbip-host";


	struct usbip_stub_driver *stub_driver;

	static struct sysfs_driver *open_sysfs_stub_driver(void)
	{
	int ret;

	char sysfs_mntpath[SYSFS_PATH_MAX];
	char stub_driver_path[SYSFS_PATH_MAX];
	struct sysfs_driver *stub_driver;


	ret = sysfs_get_mnt_path(sysfs_mntpath, SYSFS_PATH_MAX);
	if (ret < 0) {
	err("sysfs must be mounted");
	return NULL;
	}

	snprintf(stub_driver_path, SYSFS_PATH_MAX, "%s/%s/usb/%s/%s",
	sysfs_mntpath, SYSFS_BUS_NAME, SYSFS_DRIVERS_NAME,
	usbip_stub_driver_name);

	stub_driver = sysfs_open_driver_path(stub_driver_path);
	if (!stub_driver) {
	err("usbip-core.ko and usbip-host.ko must be loaded");
	return NULL;
	}

	return stub_driver;
	}


	#define SYSFS_OPEN_RETRIES 100

	/* only the first interface value is true! */
	static int32_t read_attr_usbip_status(struct usb_device *udev)
	{
	char attrpath[SYSFS_PATH_MAX];
	struct sysfs_attribute *attr;
	int value = 0;
	int ret;
	struct stat s;
	int retries = SYSFS_OPEN_RETRIES;

	/* This access is racy!
	*
	* Just after detach, our driver removes the sysfs
	* files and recreates them.
	*
	* We may try and fail to open the usbip_status of
	* an exported device in the (short) window where
	* it has been removed and not yet recreated.
	*
	* This is a bug in the interface. Nothing we can do
	* except work around it here by polling for the sysfs
	* usbip_status to reappear.
	*/

	snprintf(attrpath, SYSFS_PATH_MAX, "%s/%s:%d.%d/usbip_status",
	udev->path, udev->busid,
	udev->bConfigurationValue,
	0);

	while (retries > 0) {
	if (stat(attrpath, &s) == 0)
	break;

	if (errno != ENOENT) {
	err("error stat'ing %s", attrpath);
	return -1;
	}

	usleep(10000); /* 10ms */
	retries--;
	}

	if (retries == 0)
	err("usbip_status not ready after %d retries",
	SYSFS_OPEN_RETRIES);
	else if (retries < SYSFS_OPEN_RETRIES)
	info("warning: usbip_status ready after %d retries",
	SYSFS_OPEN_RETRIES - retries);

	attr = sysfs_open_attribute(attrpath);
	if (!attr) {
	err("open %s", attrpath);
	return -1;
	}

	ret = sysfs_read_attribute(attr);
	if (ret) {
	err("read %s", attrpath);
	sysfs_close_attribute(attr);
	return -1;
	}

	value = atoi(attr->value);

	sysfs_close_attribute(attr);

	return value;
	}


	static void usbip_exported_device_delete(void *dev)
	{
	struct usbip_exported_device *edev =
	(struct usbip_exported_device *) dev;

	sysfs_close_device(edev->sudev);
	free(dev);
	}


	static struct usbip_exported_device usbip_exported_device_new(char sdevpath)
	{
	struct usbip_exported_device *edev = NULL;

	edev = (struct usbip_exported_device ) calloc(1, sizeof(edev));
	if (!edev) {
	err("alloc device");
	return NULL;
	}

	edev->sudev = sysfs_open_device_path(sdevpath);
	if (!edev->sudev) {
	err("open %s", sdevpath);
	goto err;
	}

	read_usb_device(edev->sudev, &edev->udev);

	edev->status = read_attr_usbip_status(&edev->udev);
	if (edev->status < 0)
	goto err;

	/* reallocate buffer to include usb interface data */
	size_t size = sizeof(edev) + edev->udev.bNumInterfaces sizeof(struct usb_interface);
	edev = (struct usbip_exported_device *) realloc(edev, size);
	if (!edev) {
	err("alloc device");
	goto err;
	}

	for (int i=0; i < edev->udev.bNumInterfaces; i++)
	read_usb_interface(&edev->udev, i, &edev->uinf[i]);

	return edev;

	err:
	if (edev && edev->sudev)
	sysfs_close_device(edev->sudev);
	if (edev)
	free(edev);
	return NULL;
	}


	static int check_new(struct dlist dlist, struct sysfs_device target)
	{
	struct sysfs_device *dev;

	dlist_for_each_data(dlist, dev, struct sysfs_device) {
	if (!strncmp(dev->bus_id, target->bus_id, SYSFS_BUS_ID_SIZE))
	/* found. not new */
	return 0;
	}

	return 1;
	}

	static void delete_nothing(void *dev __attribute__((unused)))
	{
	/* do not delete anything. but, its container will be deleted. */
	}

	static int refresh_exported_devices(void)
	{
	struct sysfs_device suinf; / sysfs_device of usb_interface */
	struct dlist *suinf_list;

	struct sysfs_device sudev; / sysfs_device of usb_device */
	struct dlist *sudev_list;


	sudev_list = dlist_new_with_delete(sizeof(struct sysfs_device), delete_nothing);

	suinf_list = sysfs_get_driver_devices(stub_driver->sysfs_driver);
	if (!suinf_list) {
	printf("Bind usbip-host.ko to a usb device to be exportable!\n");
	goto bye;
	}

	/* collect unique USB devices (not interfaces) */
	dlist_for_each_data(suinf_list, suinf, struct sysfs_device) {

	/* get usb device of this usb interface */
	sudev = sysfs_get_device_parent(suinf);
	if (!sudev) {
	err("get parent dev of %s", suinf->name);
	continue;
	}

	if (check_new(sudev_list, sudev)) {
	dlist_unshift(sudev_list, sudev);
	}
	}

	dlist_for_each_data(sudev_list, sudev, struct sysfs_device) {
	struct usbip_exported_device *edev;

	edev = usbip_exported_device_new(sudev->path);
	if (!edev) {
	err("usbip_exported_device new");
	continue;
	}

	dlist_unshift(stub_driver->edev_list, (void *) edev);
	stub_driver->ndevs++;
	}


	dlist_destroy(sudev_list);

	bye:

	return 0;
	}

	int usbip_stub_refresh_device_list(void)
	{
	int ret;

	if (stub_driver->edev_list)
	dlist_destroy(stub_driver->edev_list);

	stub_driver->ndevs = 0;

	stub_driver->edev_list = dlist_new_with_delete(sizeof(struct usbip_exported_device),
	usbip_exported_device_delete);
	if (!stub_driver->edev_list) {
	err("alloc dlist");
	return -1;
	}

	ret = refresh_exported_devices();
	if (ret < 0)
	return ret;

	return 0;
	}

	int usbip_stub_driver_open(void)
	{
	int ret;


	stub_driver = (struct usbip_stub_driver ) calloc(1, sizeof(stub_driver));
	if (!stub_driver) {
	err("alloc stub_driver");
	return -1;
	}

	stub_driver->ndevs = 0;

	stub_driver->edev_list = dlist_new_with_delete(sizeof(struct usbip_exported_device),
	usbip_exported_device_delete);
	if (!stub_driver->edev_list) {
	err("alloc dlist");
	goto err;
	}

	stub_driver->sysfs_driver = open_sysfs_stub_driver();
	if (!stub_driver->sysfs_driver)
	goto err;

	ret = refresh_exported_devices();
	if (ret < 0)
	goto err;

	return 0;


	err:
	if (stub_driver->sysfs_driver)
	sysfs_close_driver(stub_driver->sysfs_driver);
	if (stub_driver->edev_list)
	dlist_destroy(stub_driver->edev_list);
	free(stub_driver);

	stub_driver = NULL;
	return -1;
	}


	void usbip_stub_driver_close(void)
	{
	if (!stub_driver)
	return;

	if (stub_driver->edev_list)
	dlist_destroy(stub_driver->edev_list);
	if (stub_driver->sysfs_driver)
	sysfs_close_driver(stub_driver->sysfs_driver);
	free(stub_driver);

	stub_driver = NULL;
	}

	int usbip_stub_export_device(struct usbip_exported_device *edev, int sockfd)
	{
	char attrpath[SYSFS_PATH_MAX];
	struct sysfs_attribute *attr;
	char sockfd_buff[30];
	int ret;


	if (edev->status != SDEV_ST_AVAILABLE) {
	info("device not available, %s", edev->udev.busid);
	switch( edev->status ) {
	case SDEV_ST_ERROR:
	info(" status SDEV_ST_ERROR");
	break;
	case SDEV_ST_USED:
	info(" status SDEV_ST_USED");
	break;
	default:
	info(" status unknown: 0x%x", edev->status);
	}
	return -1;
	}

	/* only the first interface is true */
	snprintf(attrpath, sizeof(attrpath), "%s/%s:%d.%d/%s",
	edev->udev.path,
	edev->udev.busid,
	edev->udev.bConfigurationValue, 0,
	"usbip_sockfd");

	attr = sysfs_open_attribute(attrpath);
	if (!attr) {
	err("open %s", attrpath);
	return -1;
	}

	snprintf(sockfd_buff, sizeof(sockfd_buff), "%d\n", sockfd);

	dbg("write: %s", sockfd_buff);

	ret = sysfs_write_attribute(attr, sockfd_buff, strlen(sockfd_buff));
	if (ret < 0) {
	err("write sockfd %s to %s", sockfd_buff, attrpath);
	goto err_write_sockfd;
	}

	info("connect %s", edev->udev.busid);

	err_write_sockfd:
	sysfs_close_attribute(attr);

	return ret;
	}

	struct usbip_exported_device *usbip_stub_get_device(int num)
	{
	struct usbip_exported_device *edev;
	struct dlist *dlist = stub_driver->edev_list;
	int count = 0;

	dlist_for_each_data(dlist, edev, struct usbip_exported_device) {
	if (num == count)
	return edev;
	else
	count++ ;
	}

	return NULL;
	}