linux/fs/compat_ioctl.c

// SPDX-License-Identifier: GPL-2.0
/*
 * ioctl32.c: Conversion between 32bit and 64bit native ioctls.
 *
 * Copyright (C) 1997-2000  Jakub Jelinek  (jakub@redhat.com)
 * Copyright (C) 1998  Eddie C. Dost  (ecd@skynet.be)
 * Copyright (C) 2001,2002  Andi Kleen, SuSE Labs 
 * Copyright (C) 2003       Pavel Machek (pavel@ucw.cz)
 *
 * These routines maintain argument size conversion between 32bit and 64bit
 * ioctls.
 */

#include <linux/types.h>
#include <linux/compat.h>
#include <linux/kernel.h>
#include <linux/capability.h>
#include <linux/compiler.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/ioctl.h>
#include <linux/if.h>
#include <linux/raid/md_u.h>
#include <linux/falloc.h>
#include <linux/file.h>
#include <linux/ppp-ioctl.h>
#include <linux/if_pppox.h>
#include <linux/tty.h>
#include <linux/vt_kern.h>
#include <linux/blkdev.h>
#include <linux/serial.h>
#include <linux/ctype.h>
#include <linux/syscalls.h>
#include <linux/gfp.h>
#include <linux/cec.h>

#include "internal.h"

#ifdef CONFIG_BLOCK
#include <linux/cdrom.h>
#include <linux/fd.h>
#include <scsi/scsi.h>
#include <scsi/scsi_ioctl.h>
#include <scsi/sg.h>
#endif

#include <linux/uaccess.h>
#include <linux/watchdog.h>

#include <linux/hiddev.h>


#include <linux/sort.h>

static int do_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
	int err;

	err = security_file_ioctl(file, cmd, arg);
	if (err)
		return err;

	return vfs_ioctl(file, cmd, arg);
}

#ifdef CONFIG_BLOCK
struct compat_sg_req_info { /* used by SG_GET_REQUEST_TABLE ioctl() */
	char req_state;
	char orphan;
	char sg_io_owned;
	char problem;
	int pack_id;
	compat_uptr_t usr_ptr;
	unsigned int duration;
	int unused;
};

static int sg_grt_trans(struct file *file,
		unsigned int cmd, struct compat_sg_req_info __user *o)
{
	int err, i;
	sg_req_info_t __user *r;
	r = compat_alloc_user_space(sizeof(sg_req_info_t)*SG_MAX_QUEUE);
	err = do_ioctl(file, cmd, (unsigned long)r);
	if (err < 0)
		return err;
	for (i = 0; i < SG_MAX_QUEUE; i++) {
		void __user *ptr;
		int d;

		if (copy_in_user(o + i, r + i, offsetof(sg_req_info_t, usr_ptr)) ||
		    get_user(ptr, &r[i].usr_ptr) ||
		    get_user(d, &r[i].duration) ||
		    put_user((u32)(unsigned long)(ptr), &o[i].usr_ptr) ||
		    put_user(d, &o[i].duration))
			return -EFAULT;
	}
	return err;
}
#endif /* CONFIG_BLOCK */

struct ppp_idle32 {
	compat_time_t xmit_idle;
	compat_time_t recv_idle;
};
#define PPPIOCGIDLE32		_IOR('t', 63, struct ppp_idle32)

static int ppp_gidle(struct file *file, unsigned int cmd,
		struct ppp_idle32 __user *idle32)
{
	struct ppp_idle __user *idle;
	__kernel_time_t xmit, recv;
	int err;

	idle = compat_alloc_user_space(sizeof(*idle));

	err = do_ioctl(file, PPPIOCGIDLE, (unsigned long) idle);

	if (!err) {
		if (get_user(xmit, &idle->xmit_idle) ||
		    get_user(recv, &idle->recv_idle) ||
		    put_user(xmit, &idle32->xmit_idle) ||
		    put_user(recv, &idle32->recv_idle))
			err = -EFAULT;
	}
	return err;
}

/*
 * simple reversible transform to make our table more evenly
 * distributed after sorting.
 */
#define XFORM(i) (((i) ^ ((i) << 27) ^ ((i) << 17)) & 0xffffffff)

#define COMPATIBLE_IOCTL(cmd) XFORM((u32)cmd),
static unsigned int ioctl_pointer[] = {
#ifdef CONFIG_BLOCK
/* Big S */
COMPATIBLE_IOCTL(SCSI_IOCTL_GET_IDLUN)
COMPATIBLE_IOCTL(SCSI_IOCTL_DOORLOCK)
COMPATIBLE_IOCTL(SCSI_IOCTL_DOORUNLOCK)
COMPATIBLE_IOCTL(SCSI_IOCTL_TEST_UNIT_READY)
COMPATIBLE_IOCTL(SCSI_IOCTL_GET_BUS_NUMBER)
COMPATIBLE_IOCTL(SCSI_IOCTL_SEND_COMMAND)
COMPATIBLE_IOCTL(SCSI_IOCTL_PROBE_HOST)
COMPATIBLE_IOCTL(SCSI_IOCTL_GET_PCI)
#endif
#ifdef CONFIG_BLOCK
/* SG stuff */
COMPATIBLE_IOCTL(SG_IO)
COMPATIBLE_IOCTL(SG_SET_TIMEOUT)
COMPATIBLE_IOCTL(SG_GET_TIMEOUT)
COMPATIBLE_IOCTL(SG_EMULATED_HOST)
COMPATIBLE_IOCTL(SG_GET_TRANSFORM)
COMPATIBLE_IOCTL(SG_SET_RESERVED_SIZE)
COMPATIBLE_IOCTL(SG_GET_RESERVED_SIZE)
COMPATIBLE_IOCTL(SG_GET_SCSI_ID)
COMPATIBLE_IOCTL(SG_SET_FORCE_LOW_DMA)
COMPATIBLE_IOCTL(SG_GET_LOW_DMA)
COMPATIBLE_IOCTL(SG_SET_FORCE_PACK_ID)
COMPATIBLE_IOCTL(SG_GET_PACK_ID)
COMPATIBLE_IOCTL(SG_GET_NUM_WAITING)
COMPATIBLE_IOCTL(SG_SET_DEBUG)
COMPATIBLE_IOCTL(SG_GET_SG_TABLESIZE)
COMPATIBLE_IOCTL(SG_GET_COMMAND_Q)
COMPATIBLE_IOCTL(SG_SET_COMMAND_Q)
COMPATIBLE_IOCTL(SG_GET_VERSION_NUM)
COMPATIBLE_IOCTL(SG_NEXT_CMD_LEN)
COMPATIBLE_IOCTL(SG_SCSI_RESET)
COMPATIBLE_IOCTL(SG_GET_REQUEST_TABLE)
COMPATIBLE_IOCTL(SG_SET_KEEP_ORPHAN)
COMPATIBLE_IOCTL(SG_GET_KEEP_ORPHAN)
#endif
/* PPP stuff */
COMPATIBLE_IOCTL(PPPIOCGFLAGS)
COMPATIBLE_IOCTL(PPPIOCSFLAGS)
COMPATIBLE_IOCTL(PPPIOCGASYNCMAP)
COMPATIBLE_IOCTL(PPPIOCSASYNCMAP)
COMPATIBLE_IOCTL(PPPIOCGUNIT)
COMPATIBLE_IOCTL(PPPIOCGRASYNCMAP)
COMPATIBLE_IOCTL(PPPIOCSRASYNCMAP)
COMPATIBLE_IOCTL(PPPIOCGMRU)
COMPATIBLE_IOCTL(PPPIOCSMRU)
COMPATIBLE_IOCTL(PPPIOCSMAXCID)
COMPATIBLE_IOCTL(PPPIOCGXASYNCMAP)
COMPATIBLE_IOCTL(PPPIOCSXASYNCMAP)
COMPATIBLE_IOCTL(PPPIOCXFERUNIT)
/* PPPIOCSCOMPRESS is translated */
COMPATIBLE_IOCTL(PPPIOCGNPMODE)
COMPATIBLE_IOCTL(PPPIOCSNPMODE)
COMPATIBLE_IOCTL(PPPIOCGDEBUG)
COMPATIBLE_IOCTL(PPPIOCSDEBUG)
/* PPPIOCSPASS is translated */
/* PPPIOCSACTIVE is translated */
/* PPPIOCGIDLE is translated */
COMPATIBLE_IOCTL(PPPIOCNEWUNIT)
COMPATIBLE_IOCTL(PPPIOCATTACH)
COMPATIBLE_IOCTL(PPPIOCDETACH)
COMPATIBLE_IOCTL(PPPIOCSMRRU)
COMPATIBLE_IOCTL(PPPIOCCONNECT)
COMPATIBLE_IOCTL(PPPIOCDISCONN)
COMPATIBLE_IOCTL(PPPIOCATTCHAN)
COMPATIBLE_IOCTL(PPPIOCGCHAN)
COMPATIBLE_IOCTL(PPPIOCGL2TPSTATS)
};

/*
 * Convert common ioctl arguments based on their command number
 *
 * Please do not add any code in here. Instead, implement
 * a compat_ioctl operation in the place that handleѕ the
 * ioctl for the native case.
 */
static long do_ioctl_trans(unsigned int cmd,
		 unsigned long arg, struct file *file)
{
	void __user *argp = compat_ptr(arg);

	switch (cmd) {
	case PPPIOCGIDLE32:
		return ppp_gidle(file, cmd, argp);
#ifdef CONFIG_BLOCK
	case SG_GET_REQUEST_TABLE:
		return sg_grt_trans(file, cmd, argp);
#endif
	}

	return -ENOIOCTLCMD;
}

static int compat_ioctl_check_table(unsigned int xcmd)
{
	int i;
	const int max = ARRAY_SIZE(ioctl_pointer) - 1;

	BUILD_BUG_ON(max >= (1 << 16));

	/* guess initial offset into table, assuming a
	   normalized distribution */
	i = ((xcmd >> 16) * max) >> 16;

	/* do linear search up first, until greater or equal */
	while (ioctl_pointer[i] < xcmd && i < max)
		i++;

	/* then do linear search down */
	while (ioctl_pointer[i] > xcmd && i > 0)
		i--;

	return ioctl_pointer[i] == xcmd;
}

COMPAT_SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd,
		       compat_ulong_t, arg32)
{
	unsigned long arg = arg32;
	struct fd f = fdget(fd);
	int error = -EBADF;
	if (!f.file)
		goto out;

	/* RED-PEN how should LSM module know it's handling 32bit? */
	error = security_file_ioctl(f.file, cmd, arg);
	if (error)
		goto out_fput;

	switch (cmd) {
	/* these are never seen by ->ioctl(), no argument or int argument */
	case FIOCLEX:
	case FIONCLEX:
	case FIFREEZE:
	case FITHAW:
	case FICLONE:
		goto do_ioctl;
	/* these are never seen by ->ioctl(), pointer argument */
	case FIONBIO:
	case FIOASYNC:
	case FIOQSIZE:
	case FS_IOC_FIEMAP:
	case FIGETBSZ:
	case FICLONERANGE:
	case FIDEDUPERANGE:
		goto found_handler;
	/*
	 * The next group is the stuff handled inside file_ioctl().
	 * For regular files these never reach ->ioctl(); for
	 * devices, sockets, etc. they do and one (FIONREAD) is
	 * even accepted in some cases.  In all those cases
	 * argument has the same type, so we can handle these
	 * here, shunting them towards do_vfs_ioctl().
	 * ->compat_ioctl() will never see any of those.
	 */
	/* pointer argument, never actually handled by ->ioctl() */
	case FIBMAP:
		goto found_handler;
	/* handled by some ->ioctl(); always a pointer to int */
	case FIONREAD:
		goto found_handler;
	/* these two get messy on amd64 due to alignment differences */
#if defined(CONFIG_X86_64)
	case FS_IOC_RESVSP_32:
	case FS_IOC_RESVSP64_32:
		error = compat_ioctl_preallocate(f.file, compat_ptr(arg));
		goto out_fput;
#else
	case FS_IOC_RESVSP:
	case FS_IOC_RESVSP64:
		goto found_handler;
#endif

	default:
		if (f.file->f_op->compat_ioctl) {
			error = f.file->f_op->compat_ioctl(f.file, cmd, arg);
			if (error != -ENOIOCTLCMD)
				goto out_fput;
		}

		if (!f.file->f_op->unlocked_ioctl)
			goto do_ioctl;
		break;
	}

	if (compat_ioctl_check_table(XFORM(cmd)))
		goto found_handler;

	error = do_ioctl_trans(cmd, arg, f.file);
	if (error == -ENOIOCTLCMD)
		error = -ENOTTY;

	goto out_fput;

 found_handler:
	arg = (unsigned long)compat_ptr(arg);
 do_ioctl:
	error = do_vfs_ioctl(f.file, fd, cmd, arg);
 out_fput:
	fdput(f);
 out:
	return error;
}

static int __init init_sys32_ioctl_cmp(const void *p, const void *q)
{
	unsigned int a, b;
	a = *(unsigned int *)p;
	b = *(unsigned int *)q;
	if (a > b)
		return 1;
	if (a < b)
		return -1;
	return 0;
}

static int __init init_sys32_ioctl(void)
{
	sort(ioctl_pointer, ARRAY_SIZE(ioctl_pointer), sizeof(*ioctl_pointer),
		init_sys32_ioctl_cmp, NULL);
	return 0;
}
__initcall(init_sys32_ioctl);