/*
 * Copyright (c) 2000-2006 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 * 
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */
/* Copyright (c) 1998 Apple Computer, Inc.  All rights reserved.
 *
 *	File:	bsd/kern/kern_symfile.c
 *
 * HISTORY
 */

#include <mach/vm_param.h>

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/signalvar.h>
#include <sys/resourcevar.h>
#include <sys/namei.h>
#include <sys/vnode_internal.h>
#include <sys/proc_internal.h>
#include <sys/kauth.h>
#include <sys/timeb.h>
#include <sys/times.h>
#include <sys/acct.h>
#include <sys/file_internal.h>
#include <sys/uio.h>
#include <sys/kernel.h>
#include <sys/stat.h>
#include <sys/disk.h>
#include <sys/conf.h>

#include <mach-o/loader.h>
#include <mach-o/nlist.h>

#include <kern/kalloc.h>
#include <vm/vm_kern.h>
#include <pexpert/pexpert.h>
#include <IOKit/IOHibernatePrivate.h>

/* This function is called from kern_sysctl in the current process context;
 * it is exported with the System6.0.exports, but this appears to be a legacy
 * export, as there are no internal consumers.
 */
int
get_kernel_symfile(__unused proc_t p, __unused char const **symfile)
{
    return KERN_FAILURE;
}

struct kern_direct_file_io_ref_t
{
    vfs_context_t		ctx;
    struct vnode		*vp;
};


static int file_ioctl(void * p1, void * p2, int theIoctl, caddr_t result)
{
    dev_t device = (dev_t) p1;

    return ((*bdevsw[major(device)].d_ioctl)
		    (device, theIoctl, result, S_IFBLK, p2));
}

static int device_ioctl(void * p1, __unused void * p2, int theIoctl, caddr_t result)
{
    return (VNOP_IOCTL(p1, theIoctl, result, 0, p2));
}

struct kern_direct_file_io_ref_t *
kern_open_file_for_direct_io(const char * name, 
			     kern_get_file_extents_callback_t callback, 
			     void * callback_ref,
			     dev_t * device_result,
                             uint64_t * partitionbase_result,
                             uint64_t * maxiocount_result)
{
    struct kern_direct_file_io_ref_t * ref;

    proc_t			p;
    struct vnode_attr		va;
    int				error;
    off_t			f_offset;
    uint32_t			blksize;
    uint64_t			size;
    dev_t			device;
    off_t 			maxiocount, count;

    int (*do_ioctl)(void * p1, void * p2, int theIoctl, caddr_t result);
    void * p1;
    void * p2;

    error = EFAULT;

    ref = (struct kern_direct_file_io_ref_t *) kalloc(sizeof(struct kern_direct_file_io_ref_t));
    if (!ref)
    {
	error = EFAULT;
    	goto out;
    }

    ref->vp = NULL;
    p = current_proc();		// kernproc;
    ref->ctx = vfs_context_create(vfs_context_current());

    if ((error = vnode_open(name, (O_CREAT | FWRITE), (0), 0, &ref->vp, ref->ctx)))
        goto out;

    VATTR_INIT(&va);
    VATTR_WANTED(&va, va_rdev);
    VATTR_WANTED(&va, va_fsid);
    VATTR_WANTED(&va, va_data_size);
    VATTR_WANTED(&va, va_nlink);
    error = EFAULT;
    if (vnode_getattr(ref->vp, &va, ref->ctx))
    	goto out;

    kprintf("vp va_rdev major %d minor %d\n", major(va.va_rdev), minor(va.va_rdev));
    kprintf("vp va_fsid major %d minor %d\n", major(va.va_fsid), minor(va.va_fsid));
    kprintf("vp size %qd\n", va.va_data_size);

    if (ref->vp->v_type == VREG)
    {
	/* Don't dump files with links. */
	if (va.va_nlink != 1)
	    goto out;

        device = va.va_fsid;
        p1 = (void *) device;
        p2 = p;
        do_ioctl = &file_ioctl;
    }
    else if ((ref->vp->v_type == VBLK) || (ref->vp->v_type == VCHR))
    {
	/* Partition. */
        device = va.va_rdev;

        p1 = ref->vp;
        p2 = ref->ctx;
        do_ioctl = &device_ioctl;
    }
    else
    {
	/* Don't dump to non-regular files. */
	error = EFAULT;
        goto out;
    }

    // get partition base

    error = do_ioctl(p1, p2, DKIOCGETBASE, (caddr_t) partitionbase_result);
    if (error)
        goto out;

    // get block size & constraints

    error = do_ioctl(p1, p2, DKIOCGETBLOCKSIZE, (caddr_t) &blksize);
    if (error)
        goto out;

    maxiocount = 1*1024*1024*1024;

    error = do_ioctl(p1, p2, DKIOCGETMAXBLOCKCOUNTREAD, (caddr_t) &count);
    if (error)
        count = 0;
    count *= blksize;
    if (count && (count < maxiocount))
        maxiocount = count;

    error = do_ioctl(p1, p2, DKIOCGETMAXBLOCKCOUNTWRITE, (caddr_t) &count);
    if (error)
        count = 0;
    count *= blksize;
    if (count && (count < maxiocount))
        maxiocount = count;

    error = do_ioctl(p1, p2, DKIOCGETMAXBYTECOUNTREAD, (caddr_t) &count);
    if (error)
        count = 0;
    if (count && (count < maxiocount))
        maxiocount = count;

    error = do_ioctl(p1, p2, DKIOCGETMAXBYTECOUNTWRITE, (caddr_t) &count);
    if (error)
        count = 0;
    if (count && (count < maxiocount))
        maxiocount = count;

    error = do_ioctl(p1, p2, DKIOCGETMAXSEGMENTBYTECOUNTREAD, (caddr_t) &count);
    if (error)
        count = 0;
    if (count && (count < maxiocount))
        maxiocount = count;

    error = do_ioctl(p1, p2, DKIOCGETMAXSEGMENTBYTECOUNTWRITE, (caddr_t) &count);
    if (error)
        count = 0;
    if (count && (count < maxiocount))
        maxiocount = count;

    kprintf("max io 0x%qx bytes\n", maxiocount);
    if (maxiocount_result)
        *maxiocount_result = maxiocount;

    // generate the block list

    error = 0;
    if (ref->vp->v_type == VREG)
    {
	f_offset = 0;
	while(f_offset < (off_t) va.va_data_size) 
	{
	    size_t io_size = 1*1024*1024*1024;
	    daddr64_t blkno;

	    error = VNOP_BLOCKMAP(ref->vp, f_offset, io_size, &blkno, (size_t *)&io_size, NULL, 0, NULL);
	    if (error)
		goto out;
	    callback(callback_ref, ((uint64_t) blkno) * blksize, (uint64_t) io_size);
	    f_offset += io_size;
	}
	callback(callback_ref, 0ULL, 0ULL);
    }
    else if ((ref->vp->v_type == VBLK) || (ref->vp->v_type == VCHR))
    {
        error = do_ioctl(p1, p2, DKIOCGETBLOCKCOUNT, (caddr_t) &size);
        if (error)
            goto out;
	size *= blksize;
	callback(callback_ref, 0ULL, size);
	callback(callback_ref, size, 0ULL);
    }

    if (device_result)
        *device_result = device;

out:
    kprintf("kern_open_file_for_direct_io(%d)\n", error);

    if (error && ref) {
	if (ref->vp) {
	    vnode_close(ref->vp, FWRITE, ref->ctx);
	    ref->vp = NULLVP;
	}

	vfs_context_rele(ref->ctx);
	kfree(ref, sizeof(struct kern_direct_file_io_ref_t));
	ref = NULL;
    }

    return(ref);
}

int
kern_write_file(struct kern_direct_file_io_ref_t * ref, off_t offset, caddr_t addr, vm_size_t len)
{
    return (vn_rdwr(UIO_WRITE, ref->vp,
			addr, len, offset,
			UIO_SYSSPACE32, IO_SYNC|IO_NODELOCKED|IO_UNIT, 
                        vfs_context_ucred(ref->ctx), (int *) 0,
			vfs_context_proc(ref->ctx)));
}

void
kern_close_file_for_direct_io(struct kern_direct_file_io_ref_t * ref)
{
    kprintf("kern_close_file_for_direct_io\n");

    if (ref) {
	int                error;

	if (ref->vp) {
	    error = vnode_close(ref->vp, FWRITE, ref->ctx);
	    ref->vp = NULLVP;
	    kprintf("vnode_close(%d)\n", error);
	}
	vfs_context_rele(ref->ctx);
	ref->ctx = NULL;
	kfree(ref, sizeof(struct kern_direct_file_io_ref_t));
    }
}