drivers/scsi/scsi_ioctl.c - linux - Git at Google

 /*
  * 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 <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 an identifying string at @buffer, if @buffer is non-NULL, filling
  * to the length stored at * (int *) @buffer.
  */
 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;
 }

 /*

  * The SCSI_IOCTL_SEND_COMMAND ioctl sends a command out to the SCSI host.
  * The IOCTL_NORMAL_TIMEOUT and NORMAL_RETRIES  variables are used.
  *
  * dev is the SCSI device struct ptr, *(int *) arg is the length of the
  * input data, if any, not including the command string & counts,
  * *((int *)arg + 1) is the output buffer size in bytes.
  *
  * *(char *) ((int *) arg)[2] the actual command byte.
  *
  * Note that if more than MAX_BUF bytes are requested to be transferred,
  * the ioctl will fail with error EINVAL.
  *
  * This size *does not* include the initial lengths that were passed.
  *
  * The SCSI command is read from the memory location immediately after the
  * length words, and the input data is right after the command.  The SCSI
  * routines know the command size based on the opcode decode.
  *
  * The output area is then filled in starting from the command byte.
  */

 static int ioctl_internal_command(struct scsi_device *sdev, char *cmd,
 				  int timeout, int retries)
 {
 	int result;
 	struct scsi_sense_hdr sshdr;

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

 	result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0,
 				  &sshdr, timeout, retries, NULL);

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

 	if ((driver_byte(result) & DRIVER_SENSE) &&
 	    (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;
 		case UNIT_ATTENTION:
 			if (sdev->removable) {
 				sdev->changed = 1;
 				result = 0;	/* This is no longer considered an error */
 				break;
 			}
 		default:	/* Fall through for non-removable media */
 			sdev_printk(KERN_INFO, sdev,
 				    "ioctl_internal_command return code = %x\n",
 				    result);
 			scsi_print_sense_hdr(sdev, NULL, &sshdr);
 			break;
 		}
 	}

 	SCSI_LOG_IOCTL(2, sdev_printk(KERN_INFO, sdev,
 				      "IOCTL Releasing command\n"));
 	return result;
 }

 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 SCSI driver hasn't been
  *                  updated yet, or because it isn't a SCSI
  *                  device)
  *          any copy_to_user() error on failure there
  */
 static int scsi_ioctl_get_pci(struct scsi_device *sdev, void __user *arg)
 {
 	struct device *dev = scsi_get_device(sdev->host);
 	const char *name;

         if (!dev)
 		return -ENXIO;

 	name = dev_name(dev);

 	/* compatibility with old ioctl which only returned
 	 * 20 characters */
         return copy_to_user(arg, name, min(strlen(name), (size_t)20))
 		? -EFAULT: 0;
 }


 /**
  * scsi_ioctl - Dispatch ioctl to scsi device
  * @sdev: scsi device receiving ioctl
  * @cmd: which ioctl is it
  * @arg: data associated with ioctl
  *
  * Description: The scsi_ioctl() function differs from most ioctls in that it
  * does not take a major/minor number as the dev field.  Rather, it takes
  * a pointer to a &struct scsi_device.
  */
 int scsi_ioctl(struct scsi_device *sdev, int cmd, void __user *arg)
 {
 	char scsi_cmd[MAX_COMMAND_SIZE];

 	/* Check for deprecated ioctls ... all the ioctls which don't
 	 * follow the new unique numbering scheme are deprecated */
 	switch (cmd) {
 	case SCSI_IOCTL_SEND_COMMAND:
 	case SCSI_IOCTL_TEST_UNIT_READY:
 	case SCSI_IOCTL_BENCHMARK_COMMAND:
 	case SCSI_IOCTL_SYNC:
 	case SCSI_IOCTL_START_UNIT:
 	case SCSI_IOCTL_STOP_UNIT:
 		printk(KERN_WARNING "program %s is using a deprecated SCSI "
 		       "ioctl, please convert it to SG_IO\n", current->comm);
 		break;
 	default:
 		break;
 	}

 	switch (cmd) {
 	case SCSI_IOCTL_GET_IDLUN:
 		if (!access_ok(VERIFY_WRITE, arg, sizeof(struct scsi_idlun)))
 			return -EFAULT;

 		__put_user((sdev->id & 0xff)
 			 + ((sdev->lun & 0xff) << 8)
 			 + ((sdev->channel & 0xff) << 16)
 			 + ((sdev->host->host_no & 0xff) << 24),
 			 &((struct scsi_idlun __user *)arg)->dev_id);
 		__put_user(sdev->host->unique_id,
 			 &((struct scsi_idlun __user *)arg)->host_unique_id);
 		return 0;
 	case SCSI_IOCTL_GET_BUS_NUMBER:
 		return put_user(sdev->host->host_no, (int __user *)arg);
 	case SCSI_IOCTL_PROBE_HOST:
 		return ioctl_probe(sdev->host, arg);
 	case SCSI_IOCTL_SEND_COMMAND:
 		if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
 			return -EACCES;
 		return sg_scsi_ioctl(sdev->request_queue, NULL, 0, arg);
 	case SCSI_IOCTL_DOORLOCK:
 		return scsi_set_medium_removal(sdev, SCSI_REMOVAL_PREVENT);
 	case SCSI_IOCTL_DOORUNLOCK:
 		return scsi_set_medium_removal(sdev, SCSI_REMOVAL_ALLOW);
 	case SCSI_IOCTL_TEST_UNIT_READY:
 		return scsi_test_unit_ready(sdev, IOCTL_NORMAL_TIMEOUT,
 					    NORMAL_RETRIES, NULL);
 	case SCSI_IOCTL_START_UNIT:
 		scsi_cmd[0] = START_STOP;
 		scsi_cmd[1] = 0;
 		scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0;
 		scsi_cmd[4] = 1;
 		return ioctl_internal_command(sdev, scsi_cmd,
 				     START_STOP_TIMEOUT, NORMAL_RETRIES);
 	case SCSI_IOCTL_STOP_UNIT:
 		scsi_cmd[0] = START_STOP;
 		scsi_cmd[1] = 0;
 		scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0;
 		scsi_cmd[4] = 0;
 		return ioctl_internal_command(sdev, scsi_cmd,
 				     START_STOP_TIMEOUT, NORMAL_RETRIES);
         case SCSI_IOCTL_GET_PCI:
                 return scsi_ioctl_get_pci(sdev, arg);
 	case SG_SCSI_RESET:
 		return scsi_ioctl_reset(sdev, arg);
 	default:
 		if (sdev->host->hostt->ioctl)
 			return sdev->host->hostt->ioctl(sdev, cmd, arg);
 	}
 	return -EINVAL;
 }
 EXPORT_SYMBOL(scsi_ioctl);

 /*
  * We can process a reset even when a device isn't fully operable.
  */
 int scsi_ioctl_block_when_processing_errors(struct scsi_device *sdev, int cmd,
 		bool ndelay)
 {
 	if (cmd == SG_SCSI_RESET && ndelay) {
 		if (scsi_host_in_recovery(sdev->host))
 			return -EAGAIN;
 	} else {
 		if (!scsi_block_when_processing_errors(sdev))
 			return -ENODEV;
 	}

 	return 0;
 }
 EXPORT_SYMBOL_GPL(scsi_ioctl_block_when_processing_errors);
	/*
	* 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 <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 an identifying string at @buffer, if @buffer is non-NULL, filling
	* to the length stored at * (int *) @buffer.
	*/
	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;
	}

	/*

	* The SCSI_IOCTL_SEND_COMMAND ioctl sends a command out to the SCSI host.
	* The IOCTL_NORMAL_TIMEOUT and NORMAL_RETRIES variables are used.
	*
	* dev is the SCSI device struct ptr, (int ) arg is the length of the
	* input data, if any, not including the command string & counts,
	* ((int )arg + 1) is the output buffer size in bytes.
	*
	* (char ) ((int *) arg)[2] the actual command byte.
	*
	* Note that if more than MAX_BUF bytes are requested to be transferred,
	* the ioctl will fail with error EINVAL.
	*
	* This size does not include the initial lengths that were passed.
	*
	* The SCSI command is read from the memory location immediately after the
	* length words, and the input data is right after the command. The SCSI
	* routines know the command size based on the opcode decode.
	*
	* The output area is then filled in starting from the command byte.
	*/

	static int ioctl_internal_command(struct scsi_device sdev, char cmd,
	int timeout, int retries)
	{
	int result;
	struct scsi_sense_hdr sshdr;

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

	result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0,
	&sshdr, timeout, retries, NULL);

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

	if ((driver_byte(result) & DRIVER_SENSE) &&
	(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;
	case UNIT_ATTENTION:
	if (sdev->removable) {
	sdev->changed = 1;
	result = 0; /* This is no longer considered an error */
	break;
	}
	default: /* Fall through for non-removable media */
	sdev_printk(KERN_INFO, sdev,
	"ioctl_internal_command return code = %x\n",
	result);
	scsi_print_sense_hdr(sdev, NULL, &sshdr);
	break;
	}
	}

	SCSI_LOG_IOCTL(2, sdev_printk(KERN_INFO, sdev,
	"IOCTL Releasing command\n"));
	return result;
	}

	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 SCSI driver hasn't been
	* updated yet, or because it isn't a SCSI
	* device)
	* any copy_to_user() error on failure there
	*/
	static int scsi_ioctl_get_pci(struct scsi_device sdev, void __user arg)
	{
	struct device *dev = scsi_get_device(sdev->host);
	const char *name;

	if (!dev)
	return -ENXIO;

	name = dev_name(dev);

	/* compatibility with old ioctl which only returned
	* 20 characters */
	return copy_to_user(arg, name, min(strlen(name), (size_t)20))
	? -EFAULT: 0;
	}


	/**
	* scsi_ioctl - Dispatch ioctl to scsi device
	* @sdev: scsi device receiving ioctl
	* @cmd: which ioctl is it
	* @arg: data associated with ioctl
	*
	* Description: The scsi_ioctl() function differs from most ioctls in that it
	* does not take a major/minor number as the dev field. Rather, it takes
	* a pointer to a &struct scsi_device.
	*/
	int scsi_ioctl(struct scsi_device sdev, int cmd, void __user arg)
	{
	char scsi_cmd[MAX_COMMAND_SIZE];

	/* Check for deprecated ioctls ... all the ioctls which don't
	* follow the new unique numbering scheme are deprecated */
	switch (cmd) {
	case SCSI_IOCTL_SEND_COMMAND:
	case SCSI_IOCTL_TEST_UNIT_READY:
	case SCSI_IOCTL_BENCHMARK_COMMAND:
	case SCSI_IOCTL_SYNC:
	case SCSI_IOCTL_START_UNIT:
	case SCSI_IOCTL_STOP_UNIT:
	printk(KERN_WARNING "program %s is using a deprecated SCSI "
	"ioctl, please convert it to SG_IO\n", current->comm);
	break;
	default:
	break;
	}

	switch (cmd) {
	case SCSI_IOCTL_GET_IDLUN:
	if (!access_ok(VERIFY_WRITE, arg, sizeof(struct scsi_idlun)))
	return -EFAULT;

	__put_user((sdev->id & 0xff)
	+ ((sdev->lun & 0xff) << 8)
	+ ((sdev->channel & 0xff) << 16)
	+ ((sdev->host->host_no & 0xff) << 24),
	&((struct scsi_idlun __user *)arg)->dev_id);
	__put_user(sdev->host->unique_id,
	&((struct scsi_idlun __user *)arg)->host_unique_id);
	return 0;
	case SCSI_IOCTL_GET_BUS_NUMBER:
	return put_user(sdev->host->host_no, (int __user *)arg);
	case SCSI_IOCTL_PROBE_HOST:
	return ioctl_probe(sdev->host, arg);
	case SCSI_IOCTL_SEND_COMMAND:
	if (!capable(CAP_SYS_ADMIN) \|\| !capable(CAP_SYS_RAWIO))
	return -EACCES;
	return sg_scsi_ioctl(sdev->request_queue, NULL, 0, arg);
	case SCSI_IOCTL_DOORLOCK:
	return scsi_set_medium_removal(sdev, SCSI_REMOVAL_PREVENT);
	case SCSI_IOCTL_DOORUNLOCK:
	return scsi_set_medium_removal(sdev, SCSI_REMOVAL_ALLOW);
	case SCSI_IOCTL_TEST_UNIT_READY:
	return scsi_test_unit_ready(sdev, IOCTL_NORMAL_TIMEOUT,
	NORMAL_RETRIES, NULL);
	case SCSI_IOCTL_START_UNIT:
	scsi_cmd[0] = START_STOP;
	scsi_cmd[1] = 0;
	scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0;
	scsi_cmd[4] = 1;
	return ioctl_internal_command(sdev, scsi_cmd,
	START_STOP_TIMEOUT, NORMAL_RETRIES);
	case SCSI_IOCTL_STOP_UNIT:
	scsi_cmd[0] = START_STOP;
	scsi_cmd[1] = 0;
	scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0;
	scsi_cmd[4] = 0;
	return ioctl_internal_command(sdev, scsi_cmd,
	START_STOP_TIMEOUT, NORMAL_RETRIES);
	case SCSI_IOCTL_GET_PCI:
	return scsi_ioctl_get_pci(sdev, arg);
	case SG_SCSI_RESET:
	return scsi_ioctl_reset(sdev, arg);
	default:
	if (sdev->host->hostt->ioctl)
	return sdev->host->hostt->ioctl(sdev, cmd, arg);
	}
	return -EINVAL;
	}
	EXPORT_SYMBOL(scsi_ioctl);

	/*
	* We can process a reset even when a device isn't fully operable.
	*/
	int scsi_ioctl_block_when_processing_errors(struct scsi_device *sdev, int cmd,
	bool ndelay)
	{
	if (cmd == SG_SCSI_RESET && ndelay) {
	if (scsi_host_in_recovery(sdev->host))
	return -EAGAIN;
	} else {
	if (!scsi_block_when_processing_errors(sdev))
	return -ENODEV;
	}

	return 0;
	}
	EXPORT_SYMBOL_GPL(scsi_ioctl_block_when_processing_errors);