path: root/drivers/scsi/scsi_ioctl.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Changes:
 * Arnaldo Carvalho de Melo <acme@conectiva.com.br> 08/23/2000
 * - get rid of some verify_areas and use __copy*user and __get/put_user
 *   for the ones that remain
 */
#include <linux/module.h>
#include <linux/blkdev.h>
#include <linux/interrupt.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/uaccess.h>
#include <linux/cdrom.h>

#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_eh.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_ioctl.h>
#include <scsi/sg.h>
#include <scsi/scsi_dbg.h>

#include "scsi_logging.h"

#define NORMAL_RETRIES			5
#define IOCTL_NORMAL_TIMEOUT			(10 * HZ)

#define MAX_BUF PAGE_SIZE

/**
 * ioctl_probe  --  return host identification
 * @host:	host to identify
 * @buffer:	userspace buffer for identification
 *
 * Return:
 * * if successful, %1 and an identifying string at @buffer, if @buffer
 * is non-NULL, filling to the length stored at * (int *) @buffer.
 * * <0 error code on failure.
 */
static int ioctl_probe(struct Scsi_Host *host, void __user *buffer)
{
	unsigned int len, slen;
	const char *string;

	if (buffer) {
		if (get_user(len, (unsigned int __user *) buffer))
			return -EFAULT;

		if (host->hostt->info)
			string = host->hostt->info(host);
		else
			string = host->hostt->name;
		if (string) {
			slen = strlen(string);
			if (len > slen)
				len = slen + 1;
			if (copy_to_user(buffer, string, len))
				return -EFAULT;
		}
	}
	return 1;
}

static int ioctl_internal_command(struct scsi_device *sdev, char *cmd,
				  int timeout, int retries)
{
	int result;
	struct scsi_sense_hdr sshdr;
	const struct scsi_exec_args exec_args = {
		.sshdr = &sshdr,
	};

	SCSI_LOG_IOCTL(1, sdev_printk(KERN_INFO, sdev,
				      "Trying ioctl with scsi command %d\n", *cmd));

	result = scsi_execute_cmd(sdev, cmd, REQ_OP_DRV_IN, NULL, 0, timeout,
				  retries, &exec_args);

	SCSI_LOG_IOCTL(2, sdev_printk(KERN_INFO, sdev,
				      "Ioctl returned  0x%x\n", result));

	if (result < 0)
		goto out;
	if (scsi_sense_valid(&sshdr)) {
		switch (sshdr.sense_key) {
		case ILLEGAL_REQUEST:
			if (cmd[0] == ALLOW_MEDIUM_REMOVAL)
				sdev->lockable = 0;
			else
				sdev_printk(KERN_INFO, sdev,
					    "ioctl_internal_command: "
					    "ILLEGAL REQUEST "
					    "asc=0x%x ascq=0x%x\n",
					    sshdr.asc, sshdr.ascq);
			break;
		case NOT_READY:	/* This happens if there is no disc in drive */
			if (sdev->removable)
				break;
			fallthrough;
		case UNIT_ATTENTION:
			if (sdev->removable) {
				sdev->changed = 1;
				result = 0;	/* This is no longer considered an error */
				break;
			}
			fallthrough;	/* for non-removable media */
		default:
			sdev_printk(KERN_INFO, sdev,
				    "ioctl_internal_command return code = %x\n",
				    result);
			scsi_print_sense_hdr(sdev, NULL, &sshdr);
			break;
		}
	}
out:
	SCSI_LOG_IOCTL(2, sdev_printk(KERN_INFO, sdev,
				      "IOCTL Releasing command\n"));
	return result;
}

/**
 * scsi_set_medium_removal() - send command to allow or prevent medium removal
 * @sdev: target scsi device
 * @state: removal state to set (prevent or allow)
 *
 * Returns:
 * * %0 if @sdev is not removable or not lockable or successful.
 * * non-%0 is a SCSI result code if > 0 or kernel error code if < 0.
 * * Sets @sdev->locked to the new state on success.
 */
int scsi_set_medium_removal(struct scsi_device *sdev, char state)
{
	char scsi_cmd[MAX_COMMAND_SIZE];
	int ret;

	if (!sdev->removable || !sdev->lockable)
	       return 0;

	scsi_cmd[0] = ALLOW_MEDIUM_REMOVAL;
	scsi_cmd[1] = 0;
	scsi_cmd[2] = 0;
	scsi_cmd[3] = 0;
	scsi_cmd[4] = state;
	scsi_cmd[5] = 0;

	ret = ioctl_internal_command(sdev, scsi_cmd,
			IOCTL_NORMAL_TIMEOUT, NORMAL_RETRIES);
	if (ret == 0)
		sdev->locked = (state == SCSI_REMOVAL_PREVENT);
	return ret;
}
EXPORT_SYMBOL(scsi_set_medium_removal);

/*
 * The scsi_ioctl_get_pci() function places into arg the value
 * pci_dev::slot_name (8 characters) for the PCI device (if any).
 * Returns: 0 on success
 *          -ENXIO if there isn't a PCI device pointer
 *                 (could be because the