text: // SPDX-License-Identifier: GPL-2.0-or-later
  /*
   * Copyright (C) 2015-2016 Samsung Electronics
   *               Igor Kotrasinski <i.kotrasinsk@samsung.com>
   *               Krzysztof Opasiak <k.opasiak@samsung.com>
   *
   * Refactored from usbip_host_driver.c, which is:
   * Copyright (C) 2011 matt mooney <mfm@muteddisk.com>
   *               2005-2007 Takahiro Hirofuchi
   */
  
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <fcntl.h>
  
  #include <errno.h>
  #include <unistd.h>
  
  #include <libudev.h>
  
  #include "usbip_common.h"
  #include "usbip_host_common.h"
  #include "list.h"
  #include "sysfs_utils.h"
  
  struct udev *udev_context;
  
  static int32_t read_attr_usbip_status(struct usbip_usb_device *udev)
  {
  	char status_attr_path[SYSFS_PATH_MAX];
  	int size;
  	int fd;
  	int length;
  	char status[2] = { 0 };
  	int value = 0;
  
  	size = snprintf(status_attr_path, sizeof(status_attr_path),
  			"%s/usbip_status", udev->path);
  	if (size < 0 || (unsigned int)size >= sizeof(status_attr_path)) {
  		err("usbip_status path length %i >= %lu or < 0", size,
  		    (long unsigned)sizeof(status_attr_path));
  		return -1;
  	}
  
  
  	fd = open(status_attr_path, O_RDONLY);
  	if (fd < 0) {
  		err("error opening attribute %s", status_attr_path);
  		return -1;
  	}
  
  	length = read(fd, status, 1);
  	if (length < 0) {
  		err("error reading attribute %s", status_attr_path);
  		close(fd);
  		return -1;
  	}
  
  	value = atoi(status);
  	close(fd);
  	return value;
  }
  
  static
  struct usbip_exported_device *usbip_exported_device_new(
  		struct usbip_host_driver *hdriver, const char *sdevpath)
  {
  	struct usbip_exported_device *edev = NULL;
  	struct usbip_exported_device *edev_old;
  	size_t size;
  	int i;
  
  	edev = calloc(1, sizeof(struct usbip_exported_device));
  
  	edev->sudev =
  		udev_device_new_from_syspath(udev_context, sdevpath);
  	if (!edev->sudev) {
  		err("udev_device_new_from_syspath: %s", sdevpath);
  		goto err;
  	}
  
  	if (hdriver->ops.read_device(edev->sudev, &edev->udev) < 0)
  		goto err;
  
  	edev->status = read_attr_usbip_status(&edev->udev);
  	if (edev->status < 0)
  		goto err;
  
  	/* reallocate buffer to include usb interface data */
  	size = sizeof(struct usbip_exported_device) +
  		edev->udev.bNumInterfaces * sizeof(struct usbip_usb_interface);
  
  	edev_old = edev;
  	edev = realloc(edev, size);
  	if (!edev) {
  		edev = edev_old;
  		dbg("realloc failed");
  		goto err;
  	}
  
  	for (i = 0; i < edev->udev.bNumInterfaces; i++) {
  		/* vudc does not support reading interfaces */
  		if (!hdriver->ops.read_interface)
  			break;
  		hdriver->ops.read_interface(&edev->udev, i, &edev->uinf[i]);
  	}
  
  	return edev;
  err:
  	if (edev->sudev)
  		udev_device_unref(edev->sudev);
  	if (edev)
  		free(edev);
  
  	return NULL;
  }
  
  static int refresh_exported_devices(struct usbip_host_driver *hdriver)
  {
  	struct usbip_exported_device *edev;
  	struct udev_enumerate *enumerate;
  	struct udev_list_entry *devices, *dev_list_entry;
  	struct udev_device *dev;
  	const char *path;
  
  	enumerate = udev_enumerate_new(udev_context);
  	udev_enumerate_add_match_subsystem(enumerate, hdriver->udev_subsystem);
  	udev_enumerate_scan_devices(enumerate);
  
  	devices = udev_enumerate_get_list_entry(enumerate);
  
  	udev_list_entry_foreach(dev_list_entry, devices) {
  		path = udev_list_entry_get_name(dev_list_entry);
  		dev = udev_device_new_from_syspath(udev_context,
  						   path);
  		if (dev == NULL)
  			continue;
  
  		/* Check whether device uses usbip driver. */
  		if (hdriver->ops.is_my_device(dev)) {
  			edev = usbip_exported_device_new(hdriver, path);
  			if (!edev) {
  				dbg("usbip_exported_device_new failed");
  				continue;
  			}
  
  			list_add(&edev->node, &hdriver->edev_list);
  			hdriver->ndevs++;
  		}
  	}
  
  	return 0;
  }
  
  static void usbip_exported_device_destroy(struct list_head *devs)
  {
  	struct list_head *i, *tmp;
  	struct usbip_exported_device *edev;
  
  	list_for_each_safe(i, tmp, devs) {
  		edev = list_entry(i, struct usbip_exported_device, node);
  		list_del(i);
  		free(edev);
  	}
  }
  
  int usbip_generic_driver_open(struct usbip_host_driver *hdriver)
  {
  	int rc;
  
  	udev_context = udev_new();
  	if (!udev_context) {
  		err("udev_new failed");
  		return -1;
  	}
  
  	rc = refresh_exported_devices(hdriver);
  	if (rc < 0)
  		goto err;
  	return 0;
  err:
  	udev_unref(udev_context);
  	return -1;
  }
  
  void usbip_generic_driver_close(struct usbip_host_driver *hdriver)
  {
  	if (!hdriver)
  		return;
  
  	usbip_exported_device_destroy(&hdriver->edev_list);
  
  	udev_unref(udev_context);
  }
  
  int usbip_generic_refresh_device_list(struct usbip_host_driver *hdriver)
  {
  	int rc;
  
  	usbip_exported_device_destroy(&hdriver->edev_list);
  
  	hdriver->ndevs = 0;
  	INIT_LIST_HEAD(&hdriver->edev_list);
  
  	rc = refresh_exported_devices(hdriver);
  	if (rc < 0)
  		return -1;
  
  	return 0;
  }
  
  int usbip_export_device(struct usbip_exported_device *edev, int sockfd)
  {
  	char attr_name[] = "usbip_sockfd";
  	char sockfd_attr_path[SYSFS_PATH_MAX];
  	int size;
  	char sockfd_buff[30];
  	int ret;
  
  	if (edev->status != SDEV_ST_AVAILABLE) {
  		dbg("device not available: %s", edev->udev.busid);
  		switch (edev->status) {
  		case SDEV_ST_ERROR:
  			dbg("status SDEV_ST_ERROR");
  			ret = ST_DEV_ERR;
  			break;
  		case SDEV_ST_USED:
  			dbg("status SDEV_ST_USED");
  			ret = ST_DEV_BUSY;
  			break;
  		default:
  			dbg("status unknown: 0x%x", edev->status);
  			ret = -1;
  		}
  		return ret;
  	}
  
  	/* only the first interface is true */
  	size = snprintf(sockfd_attr_path, sizeof(sockfd_attr_path), "%s/%s",
  			edev->udev.path, attr_name);
  	if (size < 0 || (unsigned int)size >= sizeof(sockfd_attr_path)) {
  		err("exported device path length %i >= %lu or < 0", size,
  		    (long unsigned)sizeof(sockfd_attr_path));
  		return -1;
  	}
  
  	size = snprintf(sockfd_buff, sizeof(sockfd_buff), "%d\n", sockfd);
  	if (size < 0 || (unsigned int)size >= sizeof(sockfd_buff)) {
  		err("socket length %i >= %lu or < 0", size,
  		    (long unsigned)sizeof(sockfd_buff));
  		return -1;
  	}
  
  	ret = write_sysfs_attribute(sockfd_attr_path, sockfd_buff,
  				    strlen(sockfd_buff));
  	if (ret < 0) {
  		err("write_sysfs_attribute failed: sockfd %s to %s",
  		    sockfd_buff, sockfd_attr_path);
  		return ret;
  	}
  
  	info("connect: %s", edev->udev.busid);
  
  	return ret;
  }
  
  struct usbip_exported_device *usbip_generic_get_device(
  		struct usbip_host_driver *hdriver, int num)
  {
  	struct list_head *i;
  	struct usbip_exported_device *edev;
  	int cnt = 0;
  
  	list_for_each(i, &hdriver->edev_list) {
  		edev = list_entry(i, struct usbip_exported_device, node);
  		if (num == cnt)
  			return edev;
  		cnt++;
  	}
  
  	return NULL;
  }
  