[apple/xnu.git] / bsd / vfs / vfs_attrlist.c

/*
 * Copyright (c) 1995-2016 Apple 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@
 */
/*
 * NOTICE: This file was modified by SPARTA, Inc. in 2005 to introduce
 * support for mandatory and extensible security protections.  This notice
 * is included in support of clause 2.2 (b) of the Apple Public License,
 * Version 2.0.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/namei.h>
#include <sys/kernel.h>
#include <sys/stat.h>
#include <sys/syslog.h>
#include <sys/vnode_internal.h>
#include <sys/mount_internal.h>
#include <sys/proc_internal.h>
#include <sys/file_internal.h>
#include <sys/kauth.h>
#include <sys/uio_internal.h>
#include <sys/malloc.h>
#include <sys/attr.h>
#include <sys/sysproto.h>
#include <sys/xattr.h>
#include <sys/fsevents.h>
#include <kern/kalloc.h>
#include <miscfs/specfs/specdev.h>

#if CONFIG_MACF
#include <security/mac_framework.h>
#endif

#define ATTR_TIME_SIZE  -1

/*
 * Structure describing the state of an in-progress attrlist operation.
 */
struct _attrlist_buf {
        char    *base;
        char    *fixedcursor;
        char    *varcursor;
        ssize_t allocated;
        ssize_t needed;
        attribute_set_t actual;
        attribute_set_t valid;
};


/*
 * Attempt to pack a fixed width attribute of size (count) bytes from
 * source to our attrlist buffer.
 */
static void
attrlist_pack_fixed(struct _attrlist_buf *ab, void *source, ssize_t count)
{
        /* 
         * Use ssize_t for pointer math purposes,
         * since a ssize_t is a signed long
         */
        ssize_t fit;

        /*
         * Compute the amount of remaining space in the attrlist buffer
         * based on how much we've used for fixed width fields vs. the
         * start of the attributes.  
         * 
         * If we've still got room, then 'fit' will contain the amount of 
         * remaining space.  
         * 
         * Note that this math is safe because, in the event that the 
         * fixed-width cursor has moved beyond the end of the buffer,
         * then, the second input into lmin() below will be negative, and 
         * we will fail the (fit > 0) check below. 
         */ 
        fit = lmin(count, ab->allocated - (ab->fixedcursor - ab->base));
        if (fit > 0) {
                /* Copy in as much as we can */
                bcopy(source, ab->fixedcursor, fit);
        }

        /* always move in increments of 4, even if we didn't pack an attribute. */
        ab->fixedcursor += roundup(count, 4);
}

/*
 * Attempt to pack one (or two) variable width attributes into the attrlist
 * buffer.  If we are trying to pack two variable width attributes, they are treated
 * as a single variable-width attribute from the POV of the system call caller.
 * 
 * Recall that a variable-width attribute has two components: the fixed-width 
 * attribute that tells the caller where to look, and the actual variable width data.
 */
static void
attrlist_pack_variable2(struct _attrlist_buf *ab, const void *source, ssize_t count, 
                const void *ext, ssize_t extcount) 
{
        /* Use ssize_t's for pointer math ease */
        struct attrreference ar;
        ssize_t fit;

        /*
         * Pack the fixed-width component to the variable object. 
         * Note that we may be able to pack the fixed width attref, but not
         * the variable (if there's no room).
         */
        ar.attr_dataoffset = ab->varcursor - ab->fixedcursor;
        ar.attr_length = count + extcount;
        attrlist_pack_fixed(ab, &ar, sizeof(ar));

        /* 
         * Use an lmin() to do a signed comparison. We use a signed comparison
         * to detect the 'out of memory' conditions as described above in the
         * fixed width check above.
         *
         * Then pack the first variable attribute as space allows.  Note that we advance
         * the variable cursor only if we we had some available space. 
         */
        fit = lmin(count, ab->allocated - (ab->varcursor - ab->base));
        if (fit > 0) {
                if (source != NULL) {
                        bcopy(source, ab->varcursor, fit);
                }
                ab->varcursor += fit;
        }

        /* Compute the available space for the second attribute */
        fit = lmin(extcount, ab->allocated - (ab->varcursor - ab->base));
        if (fit > 0) {
                /* Copy in data for the second attribute (if needed) if there is room */
                if (ext != NULL) {
                        bcopy(ext, ab->varcursor, fit);
                }
                ab->varcursor += fit;
        }
        /* always move in increments of 4 */
        ab->varcursor = (char *)roundup((uintptr_t)ab->varcursor, 4);
}

/* 
 * Packing a single variable-width attribute is the same as calling the two, but with
 * an invalid 2nd attribute.
 */
static void
attrlist_pack_variable(struct _attrlist_buf *ab, const void *source, ssize_t count)
{
        attrlist_pack_variable2(ab, source, count, NULL, 0);
}

/*
 * Attempt to pack a string. This is a special case of a variable width attribute.
 *
 * If "source" is NULL, then an empty string ("") will be packed.  If "source" is
 * not NULL, but "count" is zero, then "source" is assumed to be a NUL-terminated
 * C-string.  If "source" is not NULL and "count" is not zero, then only the first
 * "count" bytes of "source" will be copied, and a NUL terminator will be added.
 *
 * If the attrlist buffer doesn't have enough room to hold the entire string (including
 * NUL terminator), then copy as much as will fit.  The attrlist buffer's "varcursor"
 * will always be updated based on the entire length of the string (including NUL
 * terminator); this means "varcursor" may end up pointing beyond the end of the
 * allocated buffer space.
 */
static void
attrlist_pack_string(struct _attrlist_buf *ab, const char *source, ssize_t count)
{
        struct attrreference ar;
        ssize_t fit, space;

        /*
         * Supplied count is character count of string text, excluding trailing nul
         * which we always supply here.
         */
        if (source == NULL) {
                count = 0;
        } else if (count == 0) {
                count = strlen(source);
        }

        /*
         * Construct the fixed-width attribute that refers to this string. 
         */
        ar.attr_dataoffset = ab->varcursor - ab->fixedcursor;
        ar.attr_length = count + 1;
        attrlist_pack_fixed(ab, &ar, sizeof(ar));

        /*
         * Now compute how much available memory we have to copy the string text.
         *
         * space = the number of bytes available in the attribute buffer to hold the
         *         string's value.
         *
         * fit = the number of bytes to copy from the start of the string into the
         *       attribute buffer, NOT including the NUL terminator.  If the attribute
         *       buffer is large enough, this will be the string's length; otherwise, it
         *       will be equal to "space".
         */
        space = ab->allocated - (ab->varcursor - ab->base);
        fit = lmin(count, space);
        if (space > 0) {
                int bytes_to_zero;

                /* 
                 * If there is space remaining, copy data in, and 
                 * accommodate the trailing NUL terminator.
                 *
                 * NOTE: if "space" is too small to hold the string and its NUL
                 * terminator (space < fit + 1), then the string value in the attribute
                 * buffer will NOT be NUL terminated!
                 *
                 * NOTE 2: bcopy() will do nothing if the length ("fit") is zero.
                 * Therefore, we don't bother checking for that here.
                 */
                bcopy(source, ab->varcursor, fit);
                /* is there room for our trailing nul? */
                if (space > fit) {
                        ab->varcursor[fit++] = '\0';
                        /* 'fit' now the number of bytes AFTER adding in the NUL */
                        /*
                         * Zero out any additional bytes we might have as a
                         * result of rounding up.
                         */
                        bytes_to_zero = min((roundup(fit, 4) - fit),
                            space - fit);
                        if (bytes_to_zero)
                                bzero(&(ab->varcursor[fit]), bytes_to_zero);
                }
        }
        /* 
         * always move in increments of 4 (including the trailing NUL)
         */
        ab->varcursor += roundup((count+1), 4);

}

#define ATTR_PACK4(AB, V)                                                 \
        do {                                                              \
                if ((AB.allocated - (AB.fixedcursor - AB.base)) >= 4) {   \
                        *(uint32_t *)AB.fixedcursor = V;                  \
                        AB.fixedcursor += 4;                              \
                }                                                         \
        } while (0)

#define ATTR_PACK8(AB, V)                                                 \
        do {                                                              \
                if ((AB.allocated - (AB.fixedcursor - AB.base)) >= 8) {   \
                        *(uint64_t *)AB.fixedcursor = *(uint64_t *)&V;    \
                        AB.fixedcursor += 8;                              \
                }                                                         \
        } while (0)

#define ATTR_PACK(b, v) attrlist_pack_fixed(b, &v, sizeof(v))
#define ATTR_PACK_CAST(b, t, v)                                         \
        do {                                                            \
                t _f = (t)v;                                            \
                ATTR_PACK(b, _f);                                       \
        } while (0)

#define ATTR_PACK_TIME(b, v, is64)                                                      \
        do {                                                                            \
                if (is64) {                                                             \
                        struct user64_timespec us = {v.tv_sec, v.tv_nsec};              \
                        ATTR_PACK(&b, us);                                              \
                } else {                                                                \
                        struct user32_timespec us = {v.tv_sec, v.tv_nsec};              \
                        ATTR_PACK(&b, us);                                              \
                }                                                                       \
        } while(0)


/*
 * Table-driven setup for all valid common/volume attributes.
 */
struct getvolattrlist_attrtab {
        attrgroup_t     attr;
        uint64_t        bits;
#define VFSATTR_BIT(b)  (VFSATTR_ ## b)
        ssize_t         size;
};
static struct getvolattrlist_attrtab getvolattrlist_common_tab[] = {
        {ATTR_CMN_NAME,         0,                              sizeof(struct attrreference)},
        {ATTR_CMN_DEVID,        0,                              sizeof(dev_t)},
        {ATTR_CMN_FSID,         0,                              sizeof(fsid_t)},
        {ATTR_CMN_OBJTYPE,      0,                              sizeof(fsobj_type_t)},
        {ATTR_CMN_OBJTAG,       0,                              sizeof(fsobj_tag_t)},
        {ATTR_CMN_OBJID,        0,                              sizeof(fsobj_id_t)},
        {ATTR_CMN_OBJPERMANENTID, 0,                            sizeof(fsobj_id_t)},
        {ATTR_CMN_PAROBJID,     0,                              sizeof(fsobj_id_t)},
        {ATTR_CMN_SCRIPT,       0,                              sizeof(text_encoding_t)},
        {ATTR_CMN_CRTIME,       VFSATTR_BIT(f_create_time),     ATTR_TIME_SIZE},
        {ATTR_CMN_MODTIME,      VFSATTR_BIT(f_modify_time),     ATTR_TIME_SIZE},
        {ATTR_CMN_CHGTIME,      VFSATTR_BIT(f_modify_time),     ATTR_TIME_SIZE},
        {ATTR_CMN_ACCTIME,      VFSATTR_BIT(f_access_time),     ATTR_TIME_SIZE},
        {ATTR_CMN_BKUPTIME,     VFSATTR_BIT(f_backup_time),     ATTR_TIME_SIZE},
        {ATTR_CMN_FNDRINFO,     0,                              32},
        {ATTR_CMN_OWNERID,      0,                              sizeof(uid_t)},
        {ATTR_CMN_GRPID,        0,                              sizeof(gid_t)},
        {ATTR_CMN_ACCESSMASK,   0,                              sizeof(uint32_t)},
        {ATTR_CMN_FLAGS,        0,                              sizeof(uint32_t)},
        {ATTR_CMN_USERACCESS,   0,                              sizeof(uint32_t)},
        {ATTR_CMN_EXTENDED_SECURITY, 0,                         sizeof(struct attrreference)},
        {ATTR_CMN_UUID,         0,                              sizeof(guid_t)},
        {ATTR_CMN_GRPUUID,      0,                              sizeof(guid_t)},
        {ATTR_CMN_FILEID,       0,                              sizeof(uint64_t)},
        {ATTR_CMN_PARENTID,     0,                              sizeof(uint64_t)},
        {ATTR_CMN_RETURNED_ATTRS, 0,                            sizeof(attribute_set_t)},
        {ATTR_CMN_ERROR,        0,                              sizeof(uint32_t)},
        {0, 0, 0}
};
#define ATTR_CMN_VOL_INVALID \
        (ATTR_CMN_EXTENDED_SECURITY | ATTR_CMN_UUID | ATTR_CMN_GRPUUID | \
         ATTR_CMN_FILEID | ATTR_CMN_PARENTID)

static struct getvolattrlist_attrtab getvolattrlist_vol_tab[] = {
        {ATTR_VOL_FSTYPE,               0,                                              sizeof(uint32_t)},
        {ATTR_VOL_SIGNATURE,            VFSATTR_BIT(f_signature),                       sizeof(uint32_t)},
        {ATTR_VOL_SIZE,                 VFSATTR_BIT(f_blocks),                          sizeof(off_t)},
        {ATTR_VOL_SPACEFREE,            VFSATTR_BIT(f_bfree) | VFSATTR_BIT(f_bsize),    sizeof(off_t)},
        {ATTR_VOL_SPACEAVAIL,           VFSATTR_BIT(f_bavail) | VFSATTR_BIT(f_bsize),   sizeof(off_t)},
        {ATTR_VOL_MINALLOCATION,        VFSATTR_BIT(f_bsize),                           sizeof(off_t)},
        {ATTR_VOL_ALLOCATIONCLUMP,      VFSATTR_BIT(f_bsize),                           sizeof(off_t)},
        {ATTR_VOL_IOBLOCKSIZE,          VFSATTR_BIT(f_iosize),                          sizeof(uint32_t)},
        {ATTR_VOL_OBJCOUNT,             VFSATTR_BIT(f_objcount),                        sizeof(uint32_t)},
        {ATTR_VOL_FILECOUNT,            VFSATTR_BIT(f_filecount),                       sizeof(uint32_t)},
        {ATTR_VOL_DIRCOUNT,             VFSATTR_BIT(f_dircount),                        sizeof(uint32_t)},
        {ATTR_VOL_MAXOBJCOUNT,          VFSATTR_BIT(f_maxobjcount),                     sizeof(uint32_t)},
        {ATTR_VOL_MOUNTPOINT,           0,                                              sizeof(struct attrreference)},
        {ATTR_VOL_NAME,                 VFSATTR_BIT(f_vol_name),                        sizeof(struct attrreference)},
        {ATTR_VOL_MOUNTFLAGS,           0,                                              sizeof(uint32_t)},
        {ATTR_VOL_MOUNTEDDEVICE,        0,                                              sizeof(struct attrreference)},
        {ATTR_VOL_ENCODINGSUSED,        0,                                              sizeof(uint64_t)},
        {ATTR_VOL_CAPABILITIES,         VFSATTR_BIT(f_capabilities),                    sizeof(vol_capabilities_attr_t)},
        {ATTR_VOL_UUID,                 VFSATTR_BIT(f_uuid),                            sizeof(uuid_t)},
        {ATTR_VOL_QUOTA_SIZE,           VFSATTR_BIT(f_quota),                           sizeof(off_t)},
        {ATTR_VOL_RESERVED_SIZE,        VFSATTR_BIT(f_reserved),                        sizeof(off_t)},
        {ATTR_VOL_ATTRIBUTES,           VFSATTR_BIT(f_attributes),                      sizeof(vol_attributes_attr_t)},
        {ATTR_VOL_INFO, 0, 0},
        {0, 0, 0}
};

static int
getvolattrlist_parsetab(struct getvolattrlist_attrtab *tab, attrgroup_t attrs, struct vfs_attr *vsp,
                ssize_t *sizep, int is_64bit, unsigned int maxiter)
{
        attrgroup_t     recognised;

        recognised = 0;
        do {
                /* is this attribute set? */
                if (tab->attr & attrs) {
                        recognised |= tab->attr;
                        vsp->f_active |= tab->bits;
                        if (tab->size == ATTR_TIME_SIZE) {
                                if (is_64bit) {
                                        *sizep += sizeof(struct user64_timespec);
                                } else {
                                        *sizep += sizeof(struct user32_timespec);
                                }
                        } else {
                                *sizep += tab->size;
                        }
                }
        } while (((++tab)->attr != 0) && (--maxiter > 0));
        
        /* check to make sure that we recognised all of the passed-in attributes */
        if (attrs & ~recognised)
                return(EINVAL);
        return(0);
}

/*
 * Given the attributes listed in alp, configure vap to request
 * the data from a filesystem.
 */
static int
getvolattrlist_setupvfsattr(struct attrlist *alp, struct vfs_attr *vsp, ssize_t *sizep, int is_64bit)
{
        int     error;
        if (!alp)
                return EINVAL;

        /*
         * Parse the above tables.
         */
        *sizep = sizeof(uint32_t);      /* length count */
        if (alp->commonattr) {
                if ((alp->commonattr & ATTR_CMN_VOL_INVALID) &&
                    (alp->commonattr & ATTR_CMN_RETURNED_ATTRS) == 0) {
                        return (EINVAL);
                }
                if ((error = getvolattrlist_parsetab(getvolattrlist_common_tab,
                                alp->commonattr, vsp, sizep,
                                is_64bit,
                                sizeof(getvolattrlist_common_tab)/sizeof(getvolattrlist_common_tab[0]))) != 0) {
                        return(error);
                }
        }
        if (alp->volattr &&
            (error = getvolattrlist_parsetab(getvolattrlist_vol_tab, alp->volattr, vsp, sizep, is_64bit, sizeof(getvolattrlist_vol_tab)/sizeof(getvolattrlist_vol_tab[0]))) != 0)
                return(error);

        return(0);
}

/*
 * Given the attributes listed in asp and those supported
 * in the vsp, fixup the asp attributes to reflect any
 * missing attributes from the file system
 */
static void
getvolattrlist_fixupattrs(attribute_set_t *asp, struct vfs_attr *vsp)
{
        struct getvolattrlist_attrtab *tab;

        if (asp->commonattr) {
                tab = getvolattrlist_common_tab;
                do {
                        if ((tab->attr & asp->commonattr) &&
                            (tab->bits != 0) &&
                            ((tab->bits & vsp->f_supported) == 0)) {
                                asp->commonattr &= ~tab->attr;
                        }
                } while ((++tab)->attr != 0);
        }
        if (asp->volattr) {
                tab = getvolattrlist_vol_tab;
                do {
                        if ((tab->attr & asp->volattr) &&
                            (tab->bits != 0) &&
                            ((tab->bits & vsp->f_supported) == 0)) {
                                asp->volattr &= ~tab->attr;
                        }
                } while ((++tab)->attr != 0);
        }
}

/*
 * Table-driven setup for all valid common/dir/file/fork attributes against files.
 */
struct getattrlist_attrtab {
        attrgroup_t     attr;
        uint64_t        bits;
#define VATTR_BIT(b)    (VNODE_ATTR_ ## b)
        ssize_t         size;
        kauth_action_t  action;
};

/* 
 * A zero after the ATTR_ bit indicates that we don't expect the underlying FS to report back with this 
 * information, and we will synthesize it at the VFS level.
 */
static struct getattrlist_attrtab getattrlist_common_tab[] = {
        {ATTR_CMN_NAME,         VATTR_BIT(va_name),             sizeof(struct attrreference),   KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_CMN_DEVID,        0,                              sizeof(dev_t),                  KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_CMN_FSID,         0,                              sizeof(fsid_t),                 KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_CMN_OBJTYPE,      0,                              sizeof(fsobj_type_t),           KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_CMN_OBJTAG,       0,                              sizeof(fsobj_tag_t),            KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_CMN_OBJID,        VATTR_BIT(va_fileid) | VATTR_BIT(va_linkid), sizeof(fsobj_id_t), KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_CMN_OBJPERMANENTID, VATTR_BIT(va_fileid) | VATTR_BIT(va_linkid), sizeof(fsobj_id_t), KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_CMN_PAROBJID,     VATTR_BIT(va_parentid),         sizeof(fsobj_id_t),             KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_CMN_SCRIPT,       VATTR_BIT(va_encoding),         sizeof(text_encoding_t),        KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_CMN_CRTIME,       VATTR_BIT(va_create_time),      ATTR_TIME_SIZE,                 KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_CMN_MODTIME,      VATTR_BIT(va_modify_time),      ATTR_TIME_SIZE,                 KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_CMN_CHGTIME,      VATTR_BIT(va_change_time),      ATTR_TIME_SIZE,                 KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_CMN_ACCTIME,      VATTR_BIT(va_access_time),      ATTR_TIME_SIZE,                 KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_CMN_BKUPTIME,     VATTR_BIT(va_backup_time),      ATTR_TIME_SIZE,                 KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_CMN_FNDRINFO,     0,                              32,                             KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_CMN_OWNERID,      VATTR_BIT(va_uid),              sizeof(uid_t),                  KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_CMN_GRPID,        VATTR_BIT(va_gid),              sizeof(gid_t),                  KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_CMN_ACCESSMASK,   VATTR_BIT(va_mode),             sizeof(uint32_t),               KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_CMN_FLAGS,        VATTR_BIT(va_flags),            sizeof(uint32_t),               KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_CMN_GEN_COUNT,    VATTR_BIT(va_write_gencount),   sizeof(uint32_t),               KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_CMN_DOCUMENT_ID,  VATTR_BIT(va_document_id),      sizeof(uint32_t),               KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_CMN_USERACCESS,   0,                              sizeof(uint32_t),               KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_CMN_EXTENDED_SECURITY, VATTR_BIT(va_acl),         sizeof(struct attrreference),   KAUTH_VNODE_READ_SECURITY},
        {ATTR_CMN_UUID,         VATTR_BIT(va_uuuid),            sizeof(guid_t),                 KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_CMN_GRPUUID,      VATTR_BIT(va_guuid),            sizeof(guid_t),                 KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_CMN_FILEID,       VATTR_BIT(va_fileid),           sizeof(uint64_t),               KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_CMN_PARENTID,     VATTR_BIT(va_parentid),         sizeof(uint64_t),               KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_CMN_FULLPATH,     0,                              sizeof(struct attrreference),   KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_CMN_ADDEDTIME,    VATTR_BIT(va_addedtime),        ATTR_TIME_SIZE,                 KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_CMN_RETURNED_ATTRS, 0,                            sizeof(attribute_set_t),        0},
        {ATTR_CMN_ERROR,        0,                              sizeof(uint32_t),               0},
        {ATTR_CMN_DATA_PROTECT_FLAGS, VATTR_BIT(va_dataprotect_class), sizeof(uint32_t),        KAUTH_VNODE_READ_ATTRIBUTES},
        {0, 0, 0, 0}
};

static struct getattrlist_attrtab getattrlist_dir_tab[] = {
        {ATTR_DIR_LINKCOUNT,    VATTR_BIT(va_dirlinkcount),     sizeof(uint32_t),               KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_DIR_ENTRYCOUNT,   VATTR_BIT(va_nchildren),        sizeof(uint32_t),               KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_DIR_MOUNTSTATUS,  0,                              sizeof(uint32_t),               KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_DIR_ALLOCSIZE,    VATTR_BIT(va_total_alloc) | VATTR_BIT(va_total_size), sizeof(off_t), KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_DIR_IOBLOCKSIZE,  VATTR_BIT(va_iosize),           sizeof(uint32_t),               KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_DIR_DATALENGTH,   VATTR_BIT(va_total_size) | VATTR_BIT(va_data_size), sizeof(off_t), KAUTH_VNODE_READ_ATTRIBUTES},
        {0, 0, 0, 0}
};
static struct getattrlist_attrtab getattrlist_file_tab[] = {
        {ATTR_FILE_LINKCOUNT,   VATTR_BIT(va_nlink),            sizeof(uint32_t),               KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_FILE_TOTALSIZE,   VATTR_BIT(va_total_size),       sizeof(off_t),                  KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_FILE_ALLOCSIZE,   VATTR_BIT(va_total_alloc) | VATTR_BIT(va_total_size), sizeof(off_t), KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_FILE_IOBLOCKSIZE, VATTR_BIT(va_iosize),           sizeof(uint32_t),               KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_FILE_DEVTYPE,     VATTR_BIT(va_rdev),             sizeof(dev_t),                  KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_FILE_DATALENGTH,  VATTR_BIT(va_total_size) | VATTR_BIT(va_data_size), sizeof(off_t), KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_FILE_DATAALLOCSIZE, VATTR_BIT(va_total_alloc)| VATTR_BIT(va_data_alloc), sizeof(off_t), KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_FILE_RSRCLENGTH,  0,                              sizeof(off_t),                  KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_FILE_RSRCALLOCSIZE, 0,                            sizeof(off_t),                  KAUTH_VNODE_READ_ATTRIBUTES},
        {0, 0, 0, 0}
};

//for forkattr bits repurposed as new common attributes
static struct getattrlist_attrtab getattrlist_common_extended_tab[] = {
        {ATTR_CMNEXT_RELPATH,           0,                                                      sizeof(struct attrreference),   KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_CMNEXT_PRIVATESIZE,       VATTR_BIT(va_private_size),     sizeof(off_t),                                  KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_CMNEXT_LINKID,            VATTR_BIT(va_fileid) | VATTR_BIT(va_linkid),            sizeof(uint64_t),       KAUTH_VNODE_READ_ATTRIBUTES},
        {0, 0, 0, 0}
};

/*
 * This table is for attributes which are only set from the getattrlistbulk(2)
 * call. These attributes have already been set from the common, file and
 * directory tables but the vattr bits have not been recorded. Since these
 * vattr bits are only used from the bulk call, we have a seperate table for
 * these.
 * The sizes are not returned from here since the sizes have already been
 * accounted from the common, file and directory tables.
 */
static struct getattrlist_attrtab getattrlistbulk_common_tab[] = {
        {ATTR_CMN_DEVID,        VATTR_BIT(va_devid),            0,                      KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_CMN_FSID,         VATTR_BIT(va_fsid64),           0,                      KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_CMN_OBJTYPE,      VATTR_BIT(va_objtype),          0,                      KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_CMN_OBJTAG,       VATTR_BIT(va_objtag),           0,                      KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_CMN_USERACCESS,   VATTR_BIT(va_user_access),      0,                      KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_CMN_FNDRINFO,     VATTR_BIT(va_finderinfo),       0,                      KAUTH_VNODE_READ_ATTRIBUTES},
        {0, 0, 0, 0}
};

static struct getattrlist_attrtab getattrlistbulk_file_tab[] = {
        {ATTR_FILE_RSRCLENGTH,  VATTR_BIT(va_rsrc_length),      0,                      KAUTH_VNODE_READ_ATTRIBUTES},
        {ATTR_FILE_RSRCALLOCSIZE, VATTR_BIT(va_rsrc_alloc),     0,                      KAUTH_VNODE_READ_ATTRIBUTES},
        {0, 0, 0, 0}
};

static struct getattrlist_attrtab getattrlistbulk_common_extended_tab[] = {
        /* getattrlist_parsetab() expects > 1 entries */
        {0, 0, 0, 0},
        {0, 0, 0, 0}
};

/*
 * The following are attributes that VFS can derive.
 *
 * A majority of them are the same attributes that are required for stat(2) and statfs(2).
 */
#define VFS_DFLT_ATTR_VOL       (ATTR_VOL_FSTYPE | ATTR_VOL_SIGNATURE |  \
                                 ATTR_VOL_SIZE | ATTR_VOL_SPACEFREE |  ATTR_VOL_QUOTA_SIZE | ATTR_VOL_RESERVED_SIZE | \
                                 ATTR_VOL_SPACEAVAIL | ATTR_VOL_MINALLOCATION |  \
                                 ATTR_VOL_ALLOCATIONCLUMP |  ATTR_VOL_IOBLOCKSIZE |  \
                                 ATTR_VOL_MOUNTPOINT | ATTR_VOL_MOUNTFLAGS |  \
                                 ATTR_VOL_MOUNTEDDEVICE | ATTR_VOL_CAPABILITIES |  \
                                 ATTR_VOL_ATTRIBUTES | ATTR_VOL_ENCODINGSUSED)

#define VFS_DFLT_ATTR_CMN       (ATTR_CMN_NAME | ATTR_CMN_DEVID |  \
                                 ATTR_CMN_FSID | ATTR_CMN_OBJTYPE |  \
                                 ATTR_CMN_OBJTAG | ATTR_CMN_OBJID |  \
                                 ATTR_CMN_PAROBJID | ATTR_CMN_SCRIPT |  \
                                 ATTR_CMN_MODTIME | ATTR_CMN_CHGTIME |  \
                                 ATTR_CMN_FNDRINFO |  \
                                 ATTR_CMN_OWNERID  | ATTR_CMN_GRPID |  \
                                 ATTR_CMN_ACCESSMASK | ATTR_CMN_FLAGS |  \
                                 ATTR_CMN_USERACCESS | ATTR_CMN_FILEID | \
                                 ATTR_CMN_PARENTID | ATTR_CMN_RETURNED_ATTRS | \
                                 ATTR_CMN_DOCUMENT_ID | ATTR_CMN_GEN_COUNT | \
                                 ATTR_CMN_DATA_PROTECT_FLAGS)

#define VFS_DFLT_ATTR_CMN_EXT   (ATTR_CMNEXT_PRIVATESIZE | ATTR_CMNEXT_LINKID)

#define VFS_DFLT_ATTR_DIR       (ATTR_DIR_LINKCOUNT | ATTR_DIR_MOUNTSTATUS)

#define VFS_DFLT_ATTR_FILE      (ATTR_FILE_LINKCOUNT | ATTR_FILE_TOTALSIZE |  \
                                 ATTR_FILE_ALLOCSIZE  | ATTR_FILE_IOBLOCKSIZE |  \
                                 ATTR_FILE_DEVTYPE | ATTR_FILE_DATALENGTH |  \
                                 ATTR_FILE_DATAALLOCSIZE | ATTR_FILE_RSRCLENGTH |  \
                                 ATTR_FILE_RSRCALLOCSIZE)

static int
getattrlist_parsetab(struct getattrlist_attrtab *tab, attrgroup_t attrs,
    struct vnode_attr *vap, ssize_t *sizep, kauth_action_t *actionp,
    int is_64bit, unsigned int maxiter)
{
        attrgroup_t     recognised;
        recognised = 0;
        if (!tab)
                return EINVAL;

        do {
                /* is this attribute set? */
                if (tab->attr & attrs) {
                        recognised |= tab->attr;
                        if (vap)
                                vap->va_active |= tab->bits;
                        if (sizep) {
                                if (tab->size == ATTR_TIME_SIZE) {
                                        if (is_64bit) {
                                                *sizep += sizeof(
                                                    struct user64_timespec);
                                        } else {
                                                *sizep += sizeof(
                                                    struct user32_timespec);
                                        }
                                } else {
                                        *sizep += tab->size;
                                }
                        }
                        if (actionp)
                                *actionp |= tab->action;
                        if (attrs == recognised)
                                break;  /* all done, get out */
                }
        } while (((++tab)->attr != 0) && (--maxiter > 0));
        
        /* check to make sure that we recognised all of the passed-in attributes */
        if (attrs & ~recognised)
                return(EINVAL);
        return(0);
}

/*
 * Given the attributes listed in alp, configure vap to request
 * the data from a filesystem.
 */
static int
getattrlist_setupvattr(struct attrlist *alp, struct vnode_attr *vap, ssize_t *sizep, kauth_action_t *actionp, int is_64bit, int isdir, int use_fork)
{
        int     error;

        /*
         * Parse the above tables.
         */
        *sizep = sizeof(uint32_t);      /* length count */
        *actionp = 0;
        if (alp->commonattr &&
            (error = getattrlist_parsetab(getattrlist_common_tab, alp->commonattr, vap, sizep, actionp, is_64bit, sizeof(getattrlist_common_tab)/sizeof(getattrlist_common_tab[0]))) != 0)
                return(error);
        if (isdir && alp->dirattr &&
            (error = getattrlist_parsetab(getattrlist_dir_tab, alp->dirattr, vap, sizep, actionp, is_64bit, sizeof(getattrlist_dir_tab)/sizeof(getattrlist_dir_tab[0]))) != 0)
                return(error);
        if (!isdir && alp->fileattr &&
            (error = getattrlist_parsetab(getattrlist_file_tab, alp->fileattr, vap, sizep, actionp, is_64bit, sizeof(getattrlist_file_tab)/sizeof(getattrlist_file_tab[0]))) != 0)
                return(error);
        if (use_fork && alp->forkattr &&
            (error = getattrlist_parsetab(getattrlist_common_extended_tab, alp->forkattr, vap, sizep, actionp, is_64bit, sizeof(getattrlist_common_extended_tab)/sizeof(getattrlist_common_extended_tab[0]))) != 0)
                return(error);

        return(0);
}

/*
 * Given the attributes listed in alp, configure vap to request
 * the data from a filesystem.
 */
static int
getattrlist_setupvattr_all(struct attrlist *alp, struct vnode_attr *vap,
    enum vtype obj_type, ssize_t *fixedsize, int is_64bit, int use_fork)
{
        int     error = 0;

        /*
         * Parse the above tables.
         */
        if (fixedsize) {
                *fixedsize = sizeof(uint32_t);
        }
        if (alp->commonattr) {
                error = getattrlist_parsetab(getattrlist_common_tab,
                        alp->commonattr, vap, fixedsize, NULL, is_64bit,
                        sizeof(getattrlist_common_tab)/sizeof(getattrlist_common_tab[0]));

                if (!error) {
                        /* Ignore any errrors from the bulk table */
                        (void)getattrlist_parsetab(getattrlistbulk_common_tab,
                                alp->commonattr, vap, fixedsize, NULL, is_64bit,
                                sizeof(getattrlistbulk_common_tab)/sizeof(getattrlistbulk_common_tab[0]));
                        /*
                         * turn off va_fsid since we will be using only
                         * va_fsid64 for ATTR_CMN_FSID.
                         */
                        VATTR_CLEAR_ACTIVE(vap, va_fsid);
                }
        }

        if (!error && (obj_type == VNON || obj_type == VDIR) && alp->dirattr) {
                error = getattrlist_parsetab(getattrlist_dir_tab, alp->dirattr,
                                vap, fixedsize, NULL, is_64bit,
                                sizeof(getattrlist_dir_tab)/sizeof(getattrlist_dir_tab[0]));
        }

        if (!error && (obj_type != VDIR) && alp->fileattr) {
                error = getattrlist_parsetab(getattrlist_file_tab,
                        alp->fileattr, vap, fixedsize, NULL, is_64bit,
                        sizeof(getattrlist_file_tab)/sizeof(getattrlist_file_tab[0]));

                if (!error) {
                        /*Ignore any errors from the bulk table */
                        (void)getattrlist_parsetab(getattrlistbulk_file_tab,
                                alp->fileattr, vap, fixedsize, NULL, is_64bit,
                                sizeof(getattrlistbulk_file_tab)/sizeof(getattrlistbulk_file_tab[0]));
                }
        }

        /* fork attributes are like extended common attributes if enabled*/
        if (!error && use_fork && alp->forkattr) {
                error = getattrlist_parsetab(getattrlist_common_extended_tab,
                        alp->forkattr, vap, fixedsize, NULL, is_64bit,
                        sizeof(getattrlist_common_extended_tab)/sizeof(getattrlist_common_extended_tab[0]));

                if (!error) {
                        (void)getattrlist_parsetab(getattrlistbulk_common_extended_tab,
                                alp->forkattr, vap, fixedsize, NULL, is_64bit,
                                sizeof(getattrlistbulk_common_extended_tab)/sizeof(getattrlistbulk_common_extended_tab[0]));
                }
        }

        return (error);
}

int
vfs_setup_vattr_from_attrlist(struct attrlist *alp, struct vnode_attr *vap,
    enum vtype obj_vtype, ssize_t *attrs_fixed_sizep, vfs_context_t ctx)
{
        // the caller passes us no options, we assume the caller wants the new fork
        // attr behavior, hence the hardcoded 1
        return (getattrlist_setupvattr_all(alp, vap, obj_vtype,
            attrs_fixed_sizep, IS_64BIT_PROCESS(vfs_context_proc(ctx)), 1));
}




/*
 * Given the attributes listed in asp and those supported
 * in the vap, fixup the asp attributes to reflect any
 * missing attributes from the file system
 */
static void
getattrlist_fixupattrs(attribute_set_t *asp, struct vnode_attr *vap, int use_fork)
{
        struct getattrlist_attrtab *tab;

        if (asp->commonattr) {
                tab = getattrlist_common_tab;
                do {
            /* 
                         * This if() statement is slightly confusing. We're trying to
                         * iterate through all of the bits listed in the array 
                         * getattr_common_tab, and see if the filesystem was expected
                         * to support it, and whether or not we need to do anything about this.
                         * 
                         * This array is full of structs that have 4 fields (attr, bits, size, action).
                         * The first is used to store the ATTR_CMN_* bit that was being requested 
                         * from userland.  The second stores the VATTR_BIT corresponding to the field
                         * filled in vnode_attr struct.  If it is 0, then we don't typically expect
                         * the filesystem to fill in this field.  The third is the size of the field,
                         * and the fourth is the type of kauth actions needed.
                         *
                         * So, for all of the ATTR_CMN bits listed in this array, we iterate through 
                         * them, and check to see if it was both passed down to the filesystem via the
                         * va_active bitfield, and whether or not we expect it to be emitted from
                         * the filesystem.  If it wasn't supported, then we un-twiddle the bit and move
                         * on.  This is done so that we can uncheck those bits and re-request
                         * a vnode_getattr from the filesystem again.
                         */
                        if ((tab->attr & asp->commonattr) &&
                            (tab->bits & vap->va_active) &&
                            (tab->bits & vap->va_supported) == 0) {
                                asp->commonattr &= ~tab->attr;
                        }
                } while ((++tab)->attr != 0);
        }
        if (asp->dirattr) {
                tab = getattrlist_dir_tab;
                do {
                        if ((tab->attr & asp->dirattr) &&
                            (tab->bits & vap->va_active) &&
                            (vap->va_supported & tab->bits) == 0) {
                                asp->dirattr &= ~tab->attr;
                        }
                } while ((++tab)->attr != 0);
        }
        if (asp->fileattr) {
                tab = getattrlist_file_tab;
                do {
                        if ((tab->attr & asp->fileattr) &&
                            (tab->bits & vap->va_active) &&
                            (vap->va_supported & tab->bits) == 0) {
                                asp->fileattr &= ~tab->attr;
                        }
                } while ((++tab)->attr != 0);
        }
        if (use_fork && asp->forkattr) {
                tab = getattrlist_common_extended_tab;
                do {
                        if ((tab->attr & asp->forkattr) &&
                            (tab->bits & vap->va_active) &&
                            (vap->va_supported & tab->bits) == 0) {
                                asp->forkattr &= ~tab->attr;
                        }
                } while ((++tab)->attr != 0);
        }
}

static int
setattrlist_setfinderinfo(vnode_t vp, char *fndrinfo, struct vfs_context *ctx)
{
        uio_t   auio;
        char    uio_buf[UIO_SIZEOF(1)];
        int     error;

        if ((auio = uio_createwithbuffer(1, 0, UIO_SYSSPACE, UIO_WRITE, uio_buf, sizeof(uio_buf))) == NULL) {
                error = ENOMEM;
        } else {
                uio_addiov(auio, CAST_USER_ADDR_T(fndrinfo), 32);
                error = vn_setxattr(vp, XATTR_FINDERINFO_NAME, auio, XATTR_NOSECURITY, ctx);
                uio_free(auio);
        }

#if CONFIG_FSE
        if (error == 0 && need_fsevent(FSE_FINDER_INFO_CHANGED, vp)) {
            add_fsevent(FSE_FINDER_INFO_CHANGED, ctx, FSE_ARG_VNODE, vp, FSE_ARG_DONE);
        }
#endif
        return (error);
}


/*
 * Find something resembling a terminal component name in the mountedonname for vp
 *
 */
static void
getattrlist_findnamecomp(const char *mn, const char **np, ssize_t *nl)
{
        int             counting;
        const char      *cp;

        /*
         * We're looking for the last sequence of non / characters, but
         * not including any trailing / characters.
         */
        *np = NULL;
        *nl = 0;
        counting = 0;
        for (cp = mn; *cp != 0; cp++) {
                if (!counting) {
                        /* start of run of chars */
                        if (*cp != '/') {
                                *np = cp;
                                counting = 1;
                        }
                } else {
                        /* end of run of chars */
                        if (*cp == '/') {
                                *nl = cp - *np;
                                counting = 0;
                        }
                }
        }
        /* need to close run? */
        if (counting)
                *nl = cp - *np;
}


static int
getvolattrlist(vfs_context_t ctx, vnode_t vp, struct attrlist *alp,
               user_addr_t attributeBuffer, size_t bufferSize, uint64_t options,
               enum uio_seg segflg, int is_64bit)
{
        struct vfs_attr vs;
        struct vnode_attr va;
        struct _attrlist_buf ab;
        int             error;
        ssize_t         fixedsize, varsize;
        const char      *cnp = NULL;    /* protected by ATTR_CMN_NAME */
        ssize_t         cnl = 0;        /* protected by ATTR_CMN_NAME */
        int             release_str = 0;
        mount_t         mnt;
        int             return_valid;
        int             pack_invalid;

        ab.base = NULL;
        VATTR_INIT(&va);
        VFSATTR_INIT(&vs);
        vs.f_vol_name = NULL;
        mnt = vp->v_mount;

                
        /* Check for special packing semantics */
        return_valid = (alp->commonattr & ATTR_CMN_RETURNED_ATTRS);
        pack_invalid = (options & FSOPT_PACK_INVAL_ATTRS);
        if (pack_invalid) {
                /* FSOPT_PACK_INVAL_ATTRS requires ATTR_CMN_RETURNED_ATTRS */
                if (!return_valid) {
                        error = EINVAL;
                        goto out;
                }
                /* Keep invalid attrs from being uninitialized */
                bzero(&vs, sizeof (vs));
                /* Generate a valid mask for post processing */
                bcopy(&alp->commonattr, &ab.valid, sizeof (attribute_set_t));
        }

        /*
         * For now, the vnode must be the root of its filesystem.
         * To relax this, we need to be able to find the root vnode of a filesystem
         * from any vnode in the filesystem.
         */
        if (!vnode_isvroot(vp)) {
                error = EINVAL;
                VFS_DEBUG(ctx, vp, "ATTRLIST - ERROR: volume attributes requested but not the root of a filesystem");
                goto out;
        }

        /*
         * Set up the vfs_attr structure and call the filesystem.
         */
        if ((error = getvolattrlist_setupvfsattr(alp, &vs, &fixedsize, is_64bit)) != 0) {
                VFS_DEBUG(ctx, vp, "ATTRLIST - ERROR: setup for request failed");
                goto out;
        }
        if (vs.f_active != 0) {
                /* If we're going to ask for f_vol_name, allocate a buffer to point it at */
                if (VFSATTR_IS_ACTIVE(&vs, f_vol_name)) {
                        vs.f_vol_name = (char *) kalloc(MAXPATHLEN);
                        if (vs.f_vol_name == NULL) {
                                error = ENOMEM;
                                VFS_DEBUG(ctx, vp, "ATTRLIST - ERROR: could not allocate f_vol_name buffer");
                                goto out;
                        }
                }

                VFS_DEBUG(ctx, vp, "ATTRLIST -       calling to get %016llx with supported %016llx", vs.f_active, vs.f_supported);
                if ((error = vfs_getattr(mnt, &vs, ctx)) != 0) {
                        VFS_DEBUG(ctx, vp, "ATTRLIST - ERROR: filesystem returned %d", error);
                        goto out;
                }
#if CONFIG_MACF
                error = mac_mount_check_getattr(ctx, mnt, &vs);
                if (error != 0) {
                        VFS_DEBUG(ctx, vp, "ATTRLIST - ERROR: MAC framework returned %d", error);
                        goto out;
                }
#endif
                /*
                 * Did we ask for something the filesystem doesn't support?
                 */
                if (!VFSATTR_ALL_SUPPORTED(&vs)) {
                        /* default value for volume subtype */
                        if (VFSATTR_IS_ACTIVE(&vs, f_fssubtype)
                            && !VFSATTR_IS_SUPPORTED(&vs, f_fssubtype))
                                VFSATTR_RETURN(&vs, f_fssubtype, 0);

                        /*
                         * If the file system didn't supply f_signature, then
                         * default it to 'BD', which is the generic signature
                         * that most Carbon file systems should return.
                         */
                        if (VFSATTR_IS_ACTIVE(&vs, f_signature)
                            && !VFSATTR_IS_SUPPORTED(&vs, f_signature))
                                VFSATTR_RETURN(&vs, f_signature, 0x4244);

                        /* default for block size */
                        if (VFSATTR_IS_ACTIVE(&vs, f_bsize)
                            && !VFSATTR_IS_SUPPORTED(&vs, f_bsize))
                                VFSATTR_RETURN(&vs, f_bsize, mnt->mnt_devblocksize);

                        /* default value for volume f_attributes */
                        if (VFSATTR_IS_ACTIVE(&vs, f_attributes)
                            && !VFSATTR_IS_SUPPORTED(&vs, f_attributes)) {
                                vol_attributes_attr_t *attrp = &vs.f_attributes;
                
                                attrp->validattr.commonattr = VFS_DFLT_ATTR_CMN;
                                attrp->validattr.volattr = VFS_DFLT_ATTR_VOL;
                                attrp->validattr.dirattr = VFS_DFLT_ATTR_DIR;
                                attrp->validattr.fileattr = VFS_DFLT_ATTR_FILE;
                                attrp->validattr.forkattr = VFS_DFLT_ATTR_CMN_EXT;
                
                                attrp->nativeattr.commonattr =  0;
                                attrp->nativeattr.volattr = 0;
                                attrp->nativeattr.dirattr = 0;
                                attrp->nativeattr.fileattr = 0;
                                attrp->nativeattr.forkattr = 0;
                                VFSATTR_SET_SUPPORTED(&vs, f_attributes);
                        }

                        /* default value for volume f_capabilities */
                        if (VFSATTR_IS_ACTIVE(&vs, f_capabilities)) {
                                /* getattrlist is always supported now. */
                                if (!VFSATTR_IS_SUPPORTED(&vs, f_capabilities)) {
                                        vs.f_capabilities.capabilities[VOL_CAPABILITIES_FORMAT] = 0;
                                        vs.f_capabilities.capabilities[VOL_CAPABILITIES_INTERFACES] = VOL_CAP_INT_ATTRLIST;
                                        vs.f_capabilities.capabilities[VOL_CAPABILITIES_RESERVED1] = 0;
                                        vs.f_capabilities.capabilities[VOL_CAPABILITIES_RESERVED2] = 0;
        
                                        vs.f_capabilities.valid[VOL_CAPABILITIES_FORMAT] = 0;
                                        vs.f_capabilities.valid[VOL_CAPABILITIES_INTERFACES] = VOL_CAP_INT_ATTRLIST;
                                        vs.f_capabilities.valid[VOL_CAPABILITIES_RESERVED1] = 0;
                                        vs.f_capabilities.valid[VOL_CAPABILITIES_RESERVED2] = 0;
                                        VFSATTR_SET_SUPPORTED(&vs, f_capabilities);
                                }
                                else {
                                        /* OR in VOL_CAP_INT_ATTRLIST if f_capabilities is supported */
                                        vs.f_capabilities.capabilities[VOL_CAPABILITIES_INTERFACES] |= VOL_CAP_INT_ATTRLIST;
                                        vs.f_capabilities.valid[VOL_CAPABILITIES_INTERFACES] |= VOL_CAP_INT_ATTRLIST;
                                }
                        }

                        /* check to see if our fixups were enough */
                        if (!VFSATTR_ALL_SUPPORTED(&vs)) {
                                if (return_valid) {
                                        if (pack_invalid) {
                                                /* Fix up valid mask for post processing */
                                                getvolattrlist_fixupattrs(&ab.valid, &vs);
                                                
                                                /* Force packing of everything asked for */
                                                vs.f_supported = vs.f_active;
                                        } else {
                                                /* Adjust the requested attributes */
                                                getvolattrlist_fixupattrs((attribute_set_t *)&alp->commonattr, &vs);
                                        }
                                } else {
                                        error = EINVAL;
                                        goto out;
                                }
                        }
                }
        }

        /*
         * Some fields require data from the root vp
         */
        if (alp->commonattr & (ATTR_CMN_OWNERID | ATTR_CMN_GRPID | ATTR_CMN_ACCESSMASK | ATTR_CMN_FLAGS | ATTR_CMN_SCRIPT)) {
                VATTR_WANTED(&va, va_uid);
                VATTR_WANTED(&va, va_gid);
                VATTR_WANTED(&va, va_mode);
                VATTR_WANTED(&va, va_flags);
                VATTR_WANTED(&va, va_encoding);

                if ((error = vnode_getattr(vp, &va, ctx)) != 0) {
                        VFS_DEBUG(ctx, vp, "ATTRLIST - ERROR: could not fetch attributes from root vnode", vp);
                        goto out;
                }
#if CONFIG_MACF
                error = mac_vnode_check_getattr(ctx, NOCRED, vp, &va);
                if (error != 0) {
                        VFS_DEBUG(ctx, vp, "ATTRLIST - ERROR: MAC framework returned %d for root vnode", error);
                        goto out;
                }
#endif
                if (VATTR_IS_ACTIVE(&va, va_encoding) &&
                    !VATTR_IS_SUPPORTED(&va, va_encoding)) {
                        if (!return_valid || pack_invalid)
                                /* use kTextEncodingMacUnicode */
                                VATTR_RETURN(&va, va_encoding, 0x7e);
                        else
                                /* don't use a default */
                                alp->commonattr &= ~ATTR_CMN_SCRIPT;
                }
        }

        /*
         * Compute variable-size buffer requirements.
         */
        varsize = 0;
        if (alp->commonattr & ATTR_CMN_NAME) {
                if (vp->v_mount->mnt_vfsstat.f_mntonname[1] == 0x00 &&
                        vp->v_mount->mnt_vfsstat.f_mntonname[0] == '/') {
                        /* special case for boot volume.  Use root name when it's
                         * available (which is the volume name) or just the mount on
                         * name of "/".  we must do this for binary compatibility with
                         * pre Tiger code.  returning nothing for the boot volume name
                         * breaks installers - 3961058
                         */
                        cnp = vnode_getname(vp);
                        if (cnp == NULL) {
                                /* just use "/" as name */
                                cnp = &vp->v_mount->mnt_vfsstat.f_mntonname[0];
                        }
                        else {
                                release_str = 1;
                        }
                        cnl = strlen(cnp);
                }
                else {
                        getattrlist_findnamecomp(vp->v_mount->mnt_vfsstat.f_mntonname, &cnp, &cnl);
                }
                if (alp->commonattr & ATTR_CMN_NAME)
                        varsize += roundup(cnl + 1, 4);
        }
        if (alp->volattr & ATTR_VOL_MOUNTPOINT)
                varsize += roundup(strlen(mnt->mnt_vfsstat.f_mntonname) + 1, 4);
        if (alp->volattr & ATTR_VOL_NAME) {
                vs.f_vol_name[MAXPATHLEN-1] = '\0'; /* Ensure nul-termination */
                varsize += roundup(strlen(vs.f_vol_name) + 1, 4);
        }
        if (alp->volattr & ATTR_VOL_MOUNTEDDEVICE)
                varsize += roundup(strlen(mnt->mnt_vfsstat.f_mntfromname) + 1, 4);

        /*
         * Allocate a target buffer for attribute results.
         * Note that since we won't ever copy out more than the caller requested,
         * we never need to allocate more than they offer.
         */
        ab.allocated = ulmin(bufferSize, fixedsize + varsize);
        if (ab.allocated > ATTR_MAX_BUFFER) {
                error = ENOMEM;
                VFS_DEBUG(ctx, vp, "ATTRLIST - ERROR: buffer size too large (%d limit %d)", ab.allocated, ATTR_MAX_BUFFER);
                goto out;
        }
        MALLOC(ab.base, char *, ab.allocated, M_TEMP, M_ZERO | M_WAITOK);
        if (ab.base == NULL) {
                error = ENOMEM;
                VFS_DEBUG(ctx, vp, "ATTRLIST - ERROR: could not allocate %d for copy buffer", ab.allocated);
                goto out;
        }

        /*
         * Pack results into the destination buffer.
         */
        ab.fixedcursor = ab.base + sizeof(uint32_t);
        if (return_valid) {
                ab.fixedcursor += sizeof (attribute_set_t);
                bzero(&ab.actual, sizeof (ab.actual));
        }
        ab.varcursor = ab.base + fixedsize;
        ab.needed = fixedsize + varsize;

        /* common attributes **************************************************/
        if (alp->commonattr & ATTR_CMN_NAME) {
                attrlist_pack_string(&ab, cnp, cnl);
                ab.actual.commonattr |= ATTR_CMN_NAME;
        }
        if (alp->commonattr & ATTR_CMN_DEVID) {
                ATTR_PACK4(ab, mnt->mnt_vfsstat.f_fsid.val[0]);
                ab.actual.commonattr |= ATTR_CMN_DEVID;
        }
        if (alp->commonattr & ATTR_CMN_FSID) {
                ATTR_PACK8(ab, mnt->mnt_vfsstat.f_fsid);
                ab.actual.commonattr |= ATTR_CMN_FSID;
        }
        if (alp->commonattr & ATTR_CMN_OBJTYPE) {
                if (!return_valid || pack_invalid)
                        ATTR_PACK4(ab, 0);
        }
        if (alp->commonattr & ATTR_CMN_OBJTAG) {
                ATTR_PACK4(ab, vp->v_tag);
                ab.actual.commonattr |= ATTR_CMN_OBJTAG;
        }
        if (alp->commonattr & ATTR_CMN_OBJID) {
                if (!return_valid || pack_invalid) {
                        fsobj_id_t f = {0, 0};
                        ATTR_PACK8(ab, f);
                }
        }
        if (alp->commonattr & ATTR_CMN_OBJPERMANENTID) {
                if (!return_valid || pack_invalid) {
                        fsobj_id_t f = {0, 0};
                        ATTR_PACK8(ab, f);
                }
        }
        if (alp->commonattr & ATTR_CMN_PAROBJID) {
                if (!return_valid || pack_invalid) {
                        fsobj_id_t f = {0, 0};
                        ATTR_PACK8(ab, f);
                }
        }
        /* note that this returns the encoding for the volume name, not the node name */
        if (alp->commonattr & ATTR_CMN_SCRIPT) {
                ATTR_PACK4(ab, va.va_encoding);
                ab.actual.commonattr |= ATTR_CMN_SCRIPT;
        }
        if (alp->commonattr & ATTR_CMN_CRTIME) {
                ATTR_PACK_TIME(ab, vs.f_create_time, is_64bit);
                ab.actual.commonattr |= ATTR_CMN_CRTIME;
        }
        if (alp->commonattr & ATTR_CMN_MODTIME) {
                ATTR_PACK_TIME(ab, vs.f_modify_time, is_64bit);
                ab.actual.commonattr |= ATTR_CMN_MODTIME;
        }
        if (alp->commonattr & ATTR_CMN_CHGTIME) {
                if (!return_valid || pack_invalid)
                        ATTR_PACK_TIME(ab, vs.f_modify_time, is_64bit);
        }
        if (alp->commonattr & ATTR_CMN_ACCTIME) {
                ATTR_PACK_TIME(ab, vs.f_access_time, is_64bit);
                ab.actual.commonattr |= ATTR_CMN_ACCTIME;
        }
        if (alp->commonattr & ATTR_CMN_BKUPTIME) {
                ATTR_PACK_TIME(ab, vs.f_backup_time, is_64bit);
                ab.actual.commonattr |= ATTR_CMN_BKUPTIME;
        }
        if (alp->commonattr & ATTR_CMN_FNDRINFO) {
                char f[32];
                /*
                 * This attribute isn't really Finder Info, at least for HFS.
                 */
                if (vp->v_tag == VT_HFS) {
#define HFS_GET_BOOT_INFO   (FCNTL_FS_SPECIFIC_BASE + 0x00004)
                        error = VNOP_IOCTL(vp, HFS_GET_BOOT_INFO, (caddr_t)&f, 0, ctx);
                        if (error == 0) {
                                attrlist_pack_fixed(&ab, f, sizeof(f));
                                ab.actual.commonattr |= ATTR_CMN_FNDRINFO;
                        } else if (!return_valid) {
                                goto out;
                        }
                } else if (!return_valid || pack_invalid) {
                        /* XXX we could at least pass out the volume UUID here */
                        bzero(&f, sizeof(f));
                        attrlist_pack_fixed(&ab, f, sizeof(f));
                }
        }
        if (alp->commonattr & ATTR_CMN_OWNERID) {
                ATTR_PACK4(ab, va.va_uid);
                ab.actual.commonattr |= ATTR_CMN_OWNERID;
        }
        if (alp->commonattr & ATTR_CMN_GRPID) {
                ATTR_PACK4(ab, va.va_gid);
                ab.actual.commonattr |= ATTR_CMN_GRPID;
        }
        if (alp->commonattr & ATTR_CMN_ACCESSMASK) {
                ATTR_PACK_CAST(&ab, uint32_t, va.va_mode);
                ab.actual.commonattr |= ATTR_CMN_ACCESSMASK;
        }
        if (alp->commonattr & ATTR_CMN_FLAGS) {
                ATTR_PACK4(ab, va.va_flags);
                ab.actual.commonattr |= ATTR_CMN_FLAGS;
        }
        if (alp->commonattr & ATTR_CMN_USERACCESS) {    /* XXX this is expensive and also duplicate work */
                uint32_t        perms = 0;
                if (vnode_isdir(vp)) {
                        if (vnode_authorize(vp, NULL,
                                KAUTH_VNODE_ACCESS | KAUTH_VNODE_ADD_FILE | KAUTH_VNODE_ADD_SUBDIRECTORY | KAUTH_VNODE_DELETE_CHILD, ctx) == 0)
                                perms |= W_OK;
                        if (vnode_authorize(vp, NULL, KAUTH_VNODE_ACCESS | KAUTH_VNODE_LIST_DIRECTORY, ctx) == 0)
                                perms |= R_OK;
                        if (vnode_authorize(vp, NULL, KAUTH_VNODE_ACCESS | KAUTH_VNODE_SEARCH, ctx) == 0)
                                perms |= X_OK;
                } else {
                        if (vnode_authorize(vp, NULL, KAUTH_VNODE_ACCESS | KAUTH_VNODE_WRITE_DATA, ctx) == 0)
                                perms |= W_OK;
                        if (vnode_authorize(vp, NULL, KAUTH_VNODE_ACCESS | KAUTH_VNODE_READ_DATA, ctx) == 0)
                                perms |= R_OK;
                        if (vnode_authorize(vp, NULL, KAUTH_VNODE_ACCESS | KAUTH_VNODE_EXECUTE, ctx) == 0)
                                perms |= X_OK;
                }
#if CONFIG_MACF
                /* 
                 * Rather than MAC preceding DAC, in this case we want
                 * the smallest set of permissions granted by both MAC & DAC
                 * checks.  We won't add back any permissions.
                 */
                if (perms & W_OK)
                        if (mac_vnode_check_access(ctx, vp, W_OK) != 0)
                                perms &= ~W_OK;
                if (perms & R_OK)
                        if (mac_vnode_check_access(ctx, vp, R_OK) != 0)
                                perms &= ~R_OK;
                if (perms & X_OK)
                        if (mac_vnode_check_access(ctx, vp, X_OK) != 0)
                                perms &= ~X_OK;
#endif /* MAC */
                KAUTH_DEBUG("ATTRLIST - returning user access %x", perms);
                ATTR_PACK4(ab, perms);
                ab.actual.commonattr |= ATTR_CMN_USERACCESS;
        }
        /*
         * The following common volume attributes are only
         * packed when the pack_invalid mode is enabled.
         */
        if (pack_invalid) {
                uint64_t fid = 0;

                if (alp->commonattr & ATTR_CMN_EXTENDED_SECURITY)
                        attrlist_pack_variable(&ab, NULL, 0);
                if (alp->commonattr & ATTR_CMN_UUID)
                        ATTR_PACK(&ab, kauth_null_guid);
                if (alp->commonattr & ATTR_CMN_GRPUUID)
                        ATTR_PACK(&ab, kauth_null_guid);
                if (alp->commonattr & ATTR_CMN_FILEID)
                        ATTR_PACK8(ab, fid);
                if (alp->commonattr & ATTR_CMN_PARENTID)
                        ATTR_PACK8(ab, fid);
        }

        /* volume attributes **************************************************/

        if (alp->volattr & ATTR_VOL_FSTYPE) {
                ATTR_PACK_CAST(&ab, uint32_t, vfs_typenum(mnt));
                ab.actual.volattr |= ATTR_VOL_FSTYPE;
        }
        if (alp->volattr & ATTR_VOL_SIGNATURE) {
                ATTR_PACK_CAST(&ab, uint32_t, vs.f_signature);
                ab.actual.volattr |= ATTR_VOL_SIGNATURE;
        }
        if (alp->volattr & ATTR_VOL_SIZE) {
                ATTR_PACK_CAST(&ab, off_t, vs.f_bsize * vs.f_blocks);
                ab.actual.volattr |= ATTR_VOL_SIZE;
        }
        if (alp->volattr & ATTR_VOL_SPACEFREE) {
                ATTR_PACK_CAST(&ab, off_t, vs.f_bsize * vs.f_bfree);
                ab.actual.volattr |= ATTR_VOL_SPACEFREE;
        }
        if (alp->volattr & ATTR_VOL_SPACEAVAIL) {
                ATTR_PACK_CAST(&ab, off_t, vs.f_bsize * vs.f_bavail);
                ab.actual.volattr |= ATTR_VOL_SPACEAVAIL;
        }
        if (alp->volattr & ATTR_VOL_MINALLOCATION) {
                ATTR_PACK_CAST(&ab, off_t, vs.f_bsize);
                ab.actual.volattr |= ATTR_VOL_MINALLOCATION;
        }
        if (alp->volattr & ATTR_VOL_ALLOCATIONCLUMP) {
                ATTR_PACK_CAST(&ab, off_t, vs.f_bsize);                 /* not strictly true */
                ab.actual.volattr |= ATTR_VOL_ALLOCATIONCLUMP;
        }
        if (alp->volattr & ATTR_VOL_IOBLOCKSIZE) {
                ATTR_PACK_CAST(&ab, uint32_t, vs.f_iosize);
                ab.actual.volattr |= ATTR_VOL_IOBLOCKSIZE;
        }
        if (alp->volattr & ATTR_VOL_OBJCOUNT) {
                ATTR_PACK_CAST(&ab, uint32_t, vs.f_objcount);
                ab.actual.volattr |= ATTR_VOL_OBJCOUNT;
        }
        if (alp->volattr & ATTR_VOL_FILECOUNT) {
                ATTR_PACK_CAST(&ab, uint32_t, vs.f_filecount);
                ab.actual.volattr |= ATTR_VOL_FILECOUNT;
        }
        if (alp->volattr & ATTR_VOL_DIRCOUNT) {
                ATTR_PACK_CAST(&ab, uint32_t, vs.f_dircount);
                ab.actual.volattr |= ATTR_VOL_DIRCOUNT;
        }
        if (alp->volattr & ATTR_VOL_MAXOBJCOUNT) {
                ATTR_PACK_CAST(&ab, uint32_t, vs.f_maxobjcount);
                ab.actual.volattr |= ATTR_VOL_MAXOBJCOUNT;
        }
        if (alp->volattr & ATTR_VOL_MOUNTPOINT) {
                attrlist_pack_string(&ab, mnt->mnt_vfsstat.f_mntonname, 0);
                ab.actual.volattr |= ATTR_VOL_MOUNTPOINT;
        }
        if (alp->volattr & ATTR_VOL_NAME) {
                attrlist_pack_string(&ab, vs.f_vol_name, 0);
                ab.actual.volattr |= ATTR_VOL_NAME;
        }
        if (alp->volattr & ATTR_VOL_MOUNTFLAGS) {
                ATTR_PACK_CAST(&ab, uint32_t, mnt->mnt_flag);
                ab.actual.volattr |= ATTR_VOL_MOUNTFLAGS;
        }
        if (alp->volattr & ATTR_VOL_MOUNTEDDEVICE) {
                attrlist_pack_string(&ab, mnt->mnt_vfsstat.f_mntfromname, 0);
                ab.actual.volattr |= ATTR_VOL_MOUNTEDDEVICE;
        }
        if (alp->volattr & ATTR_VOL_ENCODINGSUSED) {
                if (!return_valid || pack_invalid)
                        ATTR_PACK_CAST(&ab, uint64_t, ~0LL);  /* return all encodings */
        }
        if (alp->volattr & ATTR_VOL_CAPABILITIES) {
                /* fix up volume capabilities */
                if (vfs_extendedsecurity(mnt)) {
                        vs.f_capabilities.capabilities[VOL_CAPABILITIES_INTERFACES] |= VOL_CAP_INT_EXTENDED_SECURITY;
                } else {
                        vs.f_capabilities.capabilities[VOL_CAPABILITIES_INTERFACES] &= ~VOL_CAP_INT_EXTENDED_SECURITY;
                }
                vs.f_capabilities.valid[VOL_CAPABILITIES_INTERFACES] |= VOL_CAP_INT_EXTENDED_SECURITY;
                ATTR_PACK(&ab, vs.f_capabilities);
                ab.actual.volattr |= ATTR_VOL_CAPABILITIES;
        }
        if (alp->volattr & ATTR_VOL_UUID) {
                ATTR_PACK(&ab, vs.f_uuid);
                ab.actual.volattr |= ATTR_VOL_UUID;
        }
        if (alp->volattr & ATTR_VOL_QUOTA_SIZE) {
                ATTR_PACK_CAST(&ab, off_t, vs.f_bsize * vs.f_quota);
                ab.actual.volattr |= ATTR_VOL_QUOTA_SIZE;
        }
        if (alp->volattr & ATTR_VOL_RESERVED_SIZE) {
                ATTR_PACK_CAST(&ab, off_t, vs.f_bsize * vs.f_reserved);
                ab.actual.volattr |= ATTR_VOL_RESERVED_SIZE;
        }
        if (alp->volattr & ATTR_VOL_ATTRIBUTES) {
                /* fix up volume attribute information */

                vs.f_attributes.validattr.commonattr |= VFS_DFLT_ATTR_CMN;
                vs.f_attributes.validattr.volattr |= VFS_DFLT_ATTR_VOL;
                vs.f_attributes.validattr.dirattr |= VFS_DFLT_ATTR_DIR;
                vs.f_attributes.validattr.fileattr |= VFS_DFLT_ATTR_FILE;

                if (vfs_extendedsecurity(mnt)) {
                        vs.f_attributes.validattr.commonattr |= (ATTR_CMN_EXTENDED_SECURITY | ATTR_CMN_UUID | ATTR_CMN_GRPUUID);
                } else {
                        vs.f_attributes.validattr.commonattr &= ~(ATTR_CMN_EXTENDED_SECURITY | ATTR_CMN_UUID | ATTR_CMN_GRPUUID);
                        vs.f_attributes.nativeattr.commonattr &= ~(ATTR_CMN_EXTENDED_SECURITY | ATTR_CMN_UUID | ATTR_CMN_GRPUUID);
                }
                ATTR_PACK(&ab, vs.f_attributes);
                ab.actual.volattr |= ATTR_VOL_ATTRIBUTES;
        }
        
        /* diagnostic */
        if (!return_valid && (ab.fixedcursor - ab.base) != fixedsize)
                panic("packed field size mismatch; allocated %ld but packed %ld for common %08x vol %08x",
                    fixedsize, (long) (ab.fixedcursor - ab.base), alp->commonattr, alp->volattr);
        if (!return_valid && ab.varcursor != (ab.base + ab.needed))
                panic("packed variable field size mismatch; used %ld but expected %ld", (long) (ab.varcursor - ab.base), ab.needed);

        /*
         * In the compatible case, we report the smaller of the required and returned sizes.
         * If the FSOPT_REPORT_FULLSIZE option is supplied, we report the full (required) size
         * of the result buffer, even if we copied less out.  The caller knows how big a buffer
         * they gave us, so they can always check for truncation themselves.
         */
        *(uint32_t *)ab.base = (options & FSOPT_REPORT_FULLSIZE) ? ab.needed : imin(ab.allocated, ab.needed);
        
        /* Return attribute set output if requested. */
        if (return_valid) {
                ab.actual.commonattr |= ATTR_CMN_RETURNED_ATTRS;
                if (pack_invalid) {
                        /* Only report the attributes that are valid */
                        ab.actual.commonattr &= ab.valid.commonattr;
                        ab.actual.volattr &= ab.valid.volattr;
                }
                bcopy(&ab.actual, ab.base + sizeof(uint32_t), sizeof (ab.actual));
        }

        if (UIO_SEG_IS_USER_SPACE(segflg))
                error = copyout(ab.base, CAST_USER_ADDR_T(attributeBuffer),
                                ab.allocated);
        else
                bcopy(ab.base, (void *)attributeBuffer, (size_t)ab.allocated);

out:
        if (vs.f_vol_name != NULL)
                kfree(vs.f_vol_name, MAXPATHLEN);
        if (release_str) {
                vnode_putname(cnp);
        }
        if (ab.base != NULL)
                FREE(ab.base, M_TEMP);
        VFS_DEBUG(ctx, vp, "ATTRLIST - returning %d", error);
        return(error);
}

/*
 * Pack ATTR_COMMON attributes into a user buffer.
 * alp is a pointer to the bitmap of attributes required.
 * abp is the state of the attribute filling operation.
 * The attribute data (along with some other fields that are required
 * are in ad.
 */
static errno_t
attr_pack_common(vfs_context_t ctx, struct vnode *vp,  struct attrlist *alp,
    struct _attrlist_buf *abp, struct vnode_attr *vap, int proc_is64,
    const char *cnp, ssize_t cnl, const char *fullpathptr,
    ssize_t fullpathlen, int return_valid, int pack_invalid, int vtype,
    int is_bulk)
{
        uint32_t        perms = 0;
        int             error = 0;

        if ((alp->commonattr & ATTR_CMN_ERROR) &&
            (!return_valid || pack_invalid)) {
                ATTR_PACK4((*abp), 0);
                abp->actual.commonattr |= ATTR_CMN_ERROR;
        }
        if (alp->commonattr & ATTR_CMN_NAME) {
                attrlist_pack_string(abp, cnp, cnl);
                abp->actual.commonattr |= ATTR_CMN_NAME;
        }
        if (alp->commonattr & ATTR_CMN_DEVID) {
                if (vp) {
                        ATTR_PACK4((*abp),
                            vp->v_mount->mnt_vfsstat.f_fsid.val[0]);
                        abp->actual.commonattr |= ATTR_CMN_DEVID;
                } else if (VATTR_IS_SUPPORTED(vap, va_devid)) {
                        ATTR_PACK4((*abp), vap->va_devid);
                        abp->actual.commonattr |= ATTR_CMN_DEVID;
                } else if (!return_valid || pack_invalid) {
                        ATTR_PACK4((*abp), 0);
                }
        }
        if (alp->commonattr & ATTR_CMN_FSID) {
                if (vp) {
                        ATTR_PACK8((*abp),
                            vp->v_mount->mnt_vfsstat.f_fsid);
                        abp->actual.commonattr |= ATTR_CMN_FSID;
                } else if (VATTR_IS_SUPPORTED(vap, va_fsid64)) {
                        ATTR_PACK8((*abp), vap->va_fsid64);
                        abp->actual.commonattr |= ATTR_CMN_FSID;
                } else if (!return_valid || pack_invalid) {
                        fsid_t fsid = {{0}};

                        ATTR_PACK8((*abp), fsid);
                }
        }
        if (alp->commonattr & ATTR_CMN_OBJTYPE) {
                if (vp) {
                        ATTR_PACK4((*abp), vtype);
                        abp->actual.commonattr |= ATTR_CMN_OBJTYPE;
                } else if (VATTR_IS_SUPPORTED(vap, va_objtype)) {
                        ATTR_PACK4((*abp), vap->va_objtype);
                        abp->actual.commonattr |= ATTR_CMN_OBJTYPE;
                } else if (!return_valid || pack_invalid) {
                        ATTR_PACK4((*abp), 0);
                }
        }
        if (alp->commonattr & ATTR_CMN_OBJTAG) {
                if (vp) {
                        ATTR_PACK4((*abp), vp->v_tag);
                        abp->actual.commonattr |= ATTR_CMN_OBJTAG;
                } else if (VATTR_IS_SUPPORTED(vap, va_objtag)) {
                        ATTR_PACK4((*abp), vap->va_objtag);
                        abp->actual.commonattr |= ATTR_CMN_OBJTAG;
                } else if (!return_valid || pack_invalid) {
                        ATTR_PACK4((*abp), 0);
                }
        }
        if (alp->commonattr & ATTR_CMN_OBJID) {
                /*
                 * Carbon can't deal with us reporting the target ID
                 * for links.  So we ask the filesystem to give us the
                 * source ID as well, and if it gives us one, we use
                 * it instead.
                 */
                if (vap->va_vaflags & VA_64BITOBJIDS) {
                        if (VATTR_IS_SUPPORTED(vap, va_linkid)) {
                                ATTR_PACK8((*abp),  vap->va_linkid);
                        } else {
                                ATTR_PACK8((*abp),  vap->va_fileid);
                        }
                } else {
                        fsobj_id_t f;
                        if (VATTR_IS_SUPPORTED(vap, va_linkid)) {
                                f.fid_objno = (uint32_t)vap->va_linkid;
                        } else {
                                f.fid_objno = (uint32_t)vap->va_fileid;
                        }
                        f.fid_generation = 0;
                        ATTR_PACK8((*abp), f);
                }
                abp->actual.commonattr |= ATTR_CMN_OBJID;
        }
        if (alp->commonattr & ATTR_CMN_OBJPERMANENTID) {
                /*
                 * Carbon can't deal with us reporting the target ID
                 * for links.  So we ask the filesystem to give us the
                 * source ID as well, and if it gives us one, we use
                 * it instead.
                 */
                if (vap->va_vaflags & VA_64BITOBJIDS) {
                        if (VATTR_IS_SUPPORTED(vap, va_linkid)) {
                                ATTR_PACK8((*abp),  vap->va_linkid);
                        } else {
                                ATTR_PACK8((*abp),  vap->va_fileid);
                        }
                } else {
                        fsobj_id_t f;
                        if (VATTR_IS_SUPPORTED(vap, va_linkid)) {
                                f.fid_objno = (uint32_t)vap->va_linkid;
                        } else {
                                f.fid_objno = (uint32_t)vap->va_fileid;
                        }
                        f.fid_generation = 0;
                        ATTR_PACK8((*abp), f);
                }
                abp->actual.commonattr |= ATTR_CMN_OBJPERMANENTID;
        }
        if (alp->commonattr & ATTR_CMN_PAROBJID) {
                if (vap->va_vaflags & VA_64BITOBJIDS) {
                        ATTR_PACK8((*abp), vap->va_parentid);
                } else {
                        fsobj_id_t f;
                        f.fid_objno = (uint32_t)vap->va_parentid;
                        f.fid_generation = 0;
                        ATTR_PACK8((*abp), f);
                }
                abp->actual.commonattr |= ATTR_CMN_PAROBJID;
        }
        if (alp->commonattr & ATTR_CMN_SCRIPT) {
                if (VATTR_IS_SUPPORTED(vap, va_encoding)) {
                        ATTR_PACK4((*abp), vap->va_encoding);
                        abp->actual.commonattr |= ATTR_CMN_SCRIPT;
                } else if (!return_valid || pack_invalid) {
                        ATTR_PACK4((*abp), 0x7e);
                }
        }
        if (alp->commonattr & ATTR_CMN_CRTIME) {
                ATTR_PACK_TIME((*abp), vap->va_create_time, proc_is64);
                abp->actual.commonattr |= ATTR_CMN_CRTIME;
        }
        if (alp->commonattr & ATTR_CMN_MODTIME) {
                ATTR_PACK_TIME((*abp), vap->va_modify_time, proc_is64);
                abp->actual.commonattr |= ATTR_CMN_MODTIME;
        }
        if (alp->commonattr & ATTR_CMN_CHGTIME) {
                ATTR_PACK_TIME((*abp), vap->va_change_time, proc_is64);
                abp->actual.commonattr |= ATTR_CMN_CHGTIME;
        }
        if (alp->commonattr & ATTR_CMN_ACCTIME) {
                ATTR_PACK_TIME((*abp), vap->va_access_time, proc_is64);
                abp->actual.commonattr |= ATTR_CMN_ACCTIME;
        }
        if (alp->commonattr & ATTR_CMN_BKUPTIME) {
                ATTR_PACK_TIME((*abp), vap->va_backup_time, proc_is64);
                abp->actual.commonattr |= ATTR_CMN_BKUPTIME;
        }
        /*
         * They are requesting user access, we should obtain this before getting 
         * the finder info. For some network file systems this is a performance
         * improvement.
         */
        if (alp->commonattr & ATTR_CMN_USERACCESS) {    /* this is expensive */
                if (vp && !is_bulk) {
                        if (vtype == VDIR) {
                                if (vnode_authorize(vp, NULL,
                                    KAUTH_VNODE_ACCESS | KAUTH_VNODE_ADD_FILE |
                                    KAUTH_VNODE_ADD_SUBDIRECTORY |
                                    KAUTH_VNODE_DELETE_CHILD, ctx) == 0)
                                        perms |= W_OK;

                                if (vnode_authorize(vp, NULL,
                                    KAUTH_VNODE_ACCESS |
                                    KAUTH_VNODE_LIST_DIRECTORY, ctx) == 0)
                                        perms |= R_OK;

                                if (vnode_authorize(vp, NULL, KAUTH_VNODE_ACCESS |
                                    KAUTH_VNODE_SEARCH, ctx) == 0)
                                        perms |= X_OK;
                        } else {
                                if (vnode_authorize(vp, NULL, KAUTH_VNODE_ACCESS |
                                    KAUTH_VNODE_WRITE_DATA, ctx) == 0)
                                        perms |= W_OK;

                                if (vnode_authorize(vp, NULL, KAUTH_VNODE_ACCESS | KAUTH_VNODE_READ_DATA, ctx) == 0)
                                        perms |= R_OK;
                                if (vnode_authorize(vp, NULL, KAUTH_VNODE_ACCESS | KAUTH_VNODE_EXECUTE, ctx) == 0)
                                        perms |= X_OK;
                        }
                } else if (is_bulk &&
                    VATTR_IS_SUPPORTED(vap, va_user_access)) {
                        perms = vap->va_user_access;
                }
        }
        if (alp->commonattr & ATTR_CMN_FNDRINFO) {
                size_t  fisize = 32;

                error = 0; 
                if (vp && !is_bulk) {
                        uio_t   auio;
                        char    uio_buf[UIO_SIZEOF(1)];

                        if ((auio = uio_createwithbuffer(1, 0, UIO_SYSSPACE,
                            UIO_READ, uio_buf, sizeof(uio_buf))) == NULL) {
                                error = ENOMEM;
                                goto out;
                        }
                        uio_addiov(auio, CAST_USER_ADDR_T(abp->fixedcursor),
                            fisize);
                        /* fisize may be reset to 0 after this call */
                        error = vn_getxattr(vp, XATTR_FINDERINFO_NAME, auio,
                                            &fisize, XATTR_NOSECURITY, ctx);
                        uio_free(auio);

                        /*
                         * Default to zeros if its not available,
                         * unless ATTR_CMN_RETURNED_ATTRS was requested.
                         */
                        if (error &&
                            (!return_valid || pack_invalid) &&
                            ((error == ENOATTR) || (error == ENOENT) ||
                            (error == ENOTSUP) || (error == EPERM))) {
                                VFS_DEBUG(ctx, vp, "ATTRLIST - No system.finderinfo attribute, returning zeroes");
                                bzero(abp->fixedcursor, 32);
                                error = 0;
                        }

                        if (error == 0) {
                                abp->fixedcursor += 32;
                                abp->actual.commonattr |= ATTR_CMN_FNDRINFO;
                        } else if (!return_valid) {
                                goto out;
                        } else {
                                /*
                                 * If we can inform the caller that we can't
                                 * return this attribute, reset error and
                                 * continue with the rest of the attributes.
                                 */
                                error = 0;
                        }
                } else if (VATTR_IS_SUPPORTED(vap, va_finderinfo)) {
                        bcopy(&vap->va_finderinfo[0], abp->fixedcursor, fisize);
                        abp->fixedcursor += fisize;
                        abp->actual.commonattr |= ATTR_CMN_FNDRINFO;
                } else if (!return_valid || pack_invalid) {
                        bzero(abp->fixedcursor, fisize);
                        abp->fixedcursor += fisize;
                }
        }
        if (alp->commonattr & ATTR_CMN_OWNERID) {
                ATTR_PACK4((*abp), vap->va_uid);
                abp->actual.commonattr |= ATTR_CMN_OWNERID;
        }
        if (alp->commonattr & ATTR_CMN_GRPID) {
                ATTR_PACK4((*abp), vap->va_gid);
                abp->actual.commonattr |= ATTR_CMN_GRPID;
        }
        if (alp->commonattr & ATTR_CMN_ACCESSMASK) {
                ATTR_PACK4((*abp), vap->va_mode);
                abp->actual.commonattr |= ATTR_CMN_ACCESSMASK;
        }
        if (alp->commonattr & ATTR_CMN_FLAGS) {
                ATTR_PACK4((*abp), vap->va_flags);
                abp->actual.commonattr |= ATTR_CMN_FLAGS;
        }
        if (alp->commonattr & ATTR_CMN_GEN_COUNT) {
                if (VATTR_IS_SUPPORTED(vap, va_write_gencount)) {
                        ATTR_PACK4((*abp), vap->va_write_gencount);
                        abp->actual.commonattr |= ATTR_CMN_GEN_COUNT;
                } else if (!return_valid || pack_invalid) {
                        ATTR_PACK4((*abp), 0);
                }
        }

        if (alp->commonattr & ATTR_CMN_DOCUMENT_ID) {
                if (VATTR_IS_SUPPORTED(vap, va_document_id)) {
                        ATTR_PACK4((*abp), vap->va_document_id);
                        abp->actual.commonattr |= ATTR_CMN_DOCUMENT_ID;
                } else if (!return_valid || pack_invalid) {
                        ATTR_PACK4((*abp), 0);
                }       
        }
        /* We already obtain the user access, so just fill in the buffer here */
        if (alp->commonattr & ATTR_CMN_USERACCESS) {
#if CONFIG_MACF
                if (!is_bulk && vp) {
                        /*
                         * Rather than MAC preceding DAC, in this case we want
                         * the smallest set of permissions granted by both MAC &
                         * DAC checks.  We won't add back any permissions.
                         */
                        if (perms & W_OK)
                                if (mac_vnode_check_access(ctx, vp, W_OK) != 0)
                                        perms &= ~W_OK;
                        if (perms & R_OK)
                                if (mac_vnode_check_access(ctx, vp, R_OK) != 0)
                                        perms &= ~R_OK;
                        if (perms & X_OK)
                                if (mac_vnode_check_access(ctx, vp, X_OK) != 0)
                                        perms &= ~X_OK;
                }
#endif /* MAC */
                VFS_DEBUG(ctx, vp, "ATTRLIST - granting perms %d", perms);
                if (!is_bulk && vp) {
                        ATTR_PACK4((*abp), perms);
                        abp->actual.commonattr |= ATTR_CMN_USERACCESS;
                } else if (is_bulk && VATTR_IS_SUPPORTED(vap, va_user_access)) {
                        ATTR_PACK4((*abp), perms);
                        abp->actual.commonattr |= ATTR_CMN_USERACCESS;
                } else if (!return_valid || pack_invalid) {
                        ATTR_PACK4((*abp), 0);
                }
        }
        if (alp->commonattr & ATTR_CMN_EXTENDED_SECURITY) {
                if (VATTR_IS_SUPPORTED(vap, va_acl) && (vap->va_acl != NULL)) {
                        struct kauth_filesec fsec;
                        /*
                         * We want to return a kauth_filesec (for now), but all we have is a kauth_acl.
                         */
                        fsec.fsec_magic = KAUTH_FILESEC_MAGIC;
                        fsec.fsec_owner = kauth_null_guid;
                        fsec.fsec_group = kauth_null_guid;
                        attrlist_pack_variable2(abp, &fsec, __offsetof(struct kauth_filesec, fsec_acl), vap->va_acl, KAUTH_ACL_COPYSIZE(vap->va_acl));
                        abp->actual.commonattr |= ATTR_CMN_EXTENDED_SECURITY;
                } else if (!return_valid || pack_invalid) {
                        attrlist_pack_variable(abp, NULL, 0);
                }
        }
        if (alp->commonattr & ATTR_CMN_UUID) {
                if (VATTR_IS_SUPPORTED(vap, va_uuuid)) {
                        ATTR_PACK(abp, vap->va_uuuid);
                        abp->actual.commonattr |= ATTR_CMN_UUID;
                } else if (!return_valid || pack_invalid) {
                        ATTR_PACK(abp, kauth_null_guid);
                }
        }
        if (alp->commonattr & ATTR_CMN_GRPUUID) {
                if (VATTR_IS_SUPPORTED(vap, va_guuid)) {
                        ATTR_PACK(abp, vap->va_guuid);
                        abp->actual.commonattr |= ATTR_CMN_GRPUUID;
                } else if (!return_valid || pack_invalid) {
                        ATTR_PACK(abp, kauth_null_guid);
                }
        }
        if (alp->commonattr & ATTR_CMN_FILEID) {
                ATTR_PACK8((*abp), vap->va_fileid);
                abp->actual.commonattr |= ATTR_CMN_FILEID;
        }
        if (alp->commonattr & ATTR_CMN_PARENTID) {
                ATTR_PACK8((*abp), vap->va_parentid);
                abp->actual.commonattr |= ATTR_CMN_PARENTID;
        }
        
        if (alp->commonattr & ATTR_CMN_FULLPATH) {
                if (vp) {
                        attrlist_pack_string (abp, fullpathptr, fullpathlen);
                        abp->actual.commonattr |= ATTR_CMN_FULLPATH;
                }
        }
    
        if (alp->commonattr & ATTR_CMN_ADDEDTIME) {
                if (VATTR_IS_SUPPORTED(vap, va_addedtime)) {
                        ATTR_PACK_TIME((*abp), vap->va_addedtime, proc_is64);
                        abp->actual.commonattr |= ATTR_CMN_ADDEDTIME;
                } else if (!return_valid || pack_invalid) {
                        struct timespec zerotime = {0, 0};

                        ATTR_PACK_TIME((*abp), zerotime, proc_is64);
                }
        }
        if (alp->commonattr & ATTR_CMN_DATA_PROTECT_FLAGS) {
                if (VATTR_IS_SUPPORTED(vap, va_dataprotect_class)) {
                        ATTR_PACK4((*abp), vap->va_dataprotect_class);
                        abp->actual.commonattr |= ATTR_CMN_DATA_PROTECT_FLAGS;
                } else if (!return_valid || pack_invalid) {
                        ATTR_PACK4((*abp), 0);
                }
        }
out:
        return (error);
}

static errno_t
attr_pack_dir(struct vnode *vp, struct attrlist *alp, struct _attrlist_buf *abp,
    struct vnode_attr *vap, int return_valid, int pack_invalid)
{
        if (alp->dirattr & ATTR_DIR_LINKCOUNT) {  /* full count of entries */
                ATTR_PACK4((*abp), (uint32_t)vap->va_dirlinkcount);
                abp->actual.dirattr |= ATTR_DIR_LINKCOUNT;
        }
        if (alp->dirattr & ATTR_DIR_ENTRYCOUNT) {
                ATTR_PACK4((*abp), (uint32_t)vap->va_nchildren);
                abp->actual.dirattr |= ATTR_DIR_ENTRYCOUNT;
        }
        if (alp->dirattr & ATTR_DIR_MOUNTSTATUS) {
                uint32_t mntstat;

                if (vp) {
                        /*
                         * The vnode that is passed down may either be a
                         * top level vnode of a mount stack or a mounted
                         * on vnode. In either case, the directory should
                         * be reported as a mount point.
                         */
                        if ((vp->v_flag & VROOT) ||  vnode_mountedhere(vp)) {
                                mntstat = DIR_MNTSTATUS_MNTPOINT;
                        } else {
                                mntstat = 0;
                        }
#if CONFIG_TRIGGERS
                        /*
                         * Report back on active vnode triggers
                         * that can directly trigger a mount
                         */
                        if (vp->v_resolve &&
                            !(vp->v_resolve->vr_flags & VNT_NO_DIRECT_MOUNT)) {
                                mntstat |= DIR_MNTSTATUS_TRIGGER;
                        }
#endif
                } else {
                        mntstat = 0;
                }

                ATTR_PACK4((*abp), mntstat);
                abp->actual.dirattr |= ATTR_DIR_MOUNTSTATUS;
        }
        if (alp->dirattr & ATTR_DIR_ALLOCSIZE) {
                if (VATTR_IS_SUPPORTED(vap, va_data_alloc)) {
                        ATTR_PACK8((*abp), vap->va_data_alloc);
                        abp->actual.dirattr |= ATTR_DIR_ALLOCSIZE;
                } else if (VATTR_IS_SUPPORTED(vap, va_total_alloc)) {
                        ATTR_PACK8((*abp), vap->va_total_alloc);
                        abp->actual.dirattr |= ATTR_DIR_ALLOCSIZE;
                } else if (!return_valid || pack_invalid) {
                        uint64_t zero_val = 0;
                        ATTR_PACK8((*abp), zero_val);
                }
        }
        if (alp->dirattr & ATTR_DIR_IOBLOCKSIZE) {
                if (VATTR_IS_SUPPORTED(vap, va_iosize)) {
                        ATTR_PACK4((*abp), vap->va_iosize);
                        abp->actual.dirattr |= ATTR_DIR_IOBLOCKSIZE;
                } else if (!return_valid || pack_invalid) {
                        ATTR_PACK4((*abp), 0);
                }
        }
        /*
         * If the filesystem does not support datalength
         * or dataallocsize, then we infer that totalsize and
         * totalalloc are substitutes.
         */
        if (alp->dirattr & ATTR_DIR_DATALENGTH) {
                if (VATTR_IS_SUPPORTED(vap, va_data_size)) {
                        ATTR_PACK8((*abp), vap->va_data_size);
                        abp->actual.dirattr |= ATTR_DIR_DATALENGTH;
                } else if (VATTR_IS_SUPPORTED(vap, va_total_size)) {
                        ATTR_PACK8((*abp), vap->va_total_size);
                        abp->actual.dirattr |= ATTR_DIR_DATALENGTH;
                } else if (!return_valid || pack_invalid) {
                        uint64_t zero_val = 0;
                        ATTR_PACK8((*abp), zero_val);
                }
        }

        return 0;
}

/*
 * The is_bulk parameter differentiates whether the function is called from
 * getattrlist or getattrlistbulk. When coming in from getattrlistbulk,
 * the corresponding va_* values are expected to be the values filled and no
 * attempt is made to retrieve them by calling back into the filesystem.
 */
static errno_t
attr_pack_file(vfs_context_t ctx, struct vnode *vp,  struct attrlist *alp,
    struct _attrlist_buf *abp, struct vnode_attr *vap, int return_valid,
    int pack_invalid, int is_bulk)
{
        size_t  rsize = 0;
        uint64_t rlength = 0;
        uint64_t ralloc = 0;
        int error = 0;

        /*
         * Pre-fetch the rsrc attributes now so we only get them once.
         * Fetch the resource fork size/allocation via xattr interface
         */
        if (vp && !is_bulk &&
            (alp->fileattr & (ATTR_FILE_TOTALSIZE | ATTR_FILE_ALLOCSIZE |
            ATTR_FILE_RSRCLENGTH | ATTR_FILE_RSRCALLOCSIZE))) {

                error = vn_getxattr(vp, XATTR_RESOURCEFORK_NAME, NULL,
                    &rsize, XATTR_NOSECURITY, ctx);
                if (error) {
                        if ((error == ENOENT) || (error == ENOATTR) ||
                            (error == ENOTSUP) || (error == EPERM) ||
                            (error == EACCES)) {
                                rsize = 0;
                                error = 0;
                        } else {
                                goto out;
                        }
                }
                rlength = rsize;

                if (alp->fileattr & (ATTR_FILE_RSRCALLOCSIZE |
                    ATTR_FILE_ALLOCSIZE)) {
                        uint32_t  blksize;

                        blksize = vp->v_mount->mnt_vfsstat.f_bsize;

                        if (blksize == 0) {
                                blksize = 512;
                        }
                        ralloc = roundup(rsize, blksize);
                }
        }

        if (alp->fileattr & ATTR_FILE_LINKCOUNT) {
                ATTR_PACK4((*abp), (uint32_t)vap->va_nlink);
                abp->actual.fileattr |= ATTR_FILE_LINKCOUNT;
        }
        /*
         * Note the following caveats for the TOTALSIZE and ALLOCSIZE attributes:
         * We infer that if the filesystem does not support va_data_size or va_data_alloc
         * it must not know about alternate forks.  So when we need to gather
         * the total size or total alloc, it's OK to substitute the total size for
         * the data size below.  This is because it is likely a flat filesystem and we must
         * be using AD files to store the rsrc fork and EAs.
         *
         * Additionally, note that getattrlist is barred from being called on
         * resource fork paths. (Search for CN_ALLOWRSRCFORK).  So if the filesystem does
         * support va_data_size, it is guaranteed to represent the data fork's size.  This
         * is an important distinction to make because when we call vnode_getattr on
         * an HFS resource fork vnode, to get the size, it will vend out the resource
         * fork's size (it only gets the size of the passed-in vnode).
         */
        if (alp->fileattr & ATTR_FILE_TOTALSIZE) {
                if (!is_bulk) {
                        uint64_t totalsize = rlength;

                        if (VATTR_IS_SUPPORTED(vap, va_data_size)) {
                                totalsize += vap->va_data_size;
                        } else if (VATTR_IS_SUPPORTED(vap, va_total_size)) {
                                totalsize += vap->va_total_size;
                        }

                        ATTR_PACK8((*abp), totalsize);
                        abp->actual.fileattr |= ATTR_FILE_TOTALSIZE;
                } else if (VATTR_IS_SUPPORTED(vap, va_total_size)) {
                        ATTR_PACK8((*abp), vap->va_total_size);
                        abp->actual.fileattr |= ATTR_FILE_TOTALSIZE;
                } else if (!return_valid || pack_invalid) {
                        uint64_t zero_val = 0;

                        ATTR_PACK8((*abp), zero_val);
                }
        }
        if (alp->fileattr & ATTR_FILE_ALLOCSIZE) {
                if (!is_bulk) {
                        uint64_t totalalloc = ralloc;

                        /*
                         * If data_alloc is supported, then it must represent the
                         * data fork size.
                         */
                        if (VATTR_IS_SUPPORTED(vap, va_data_alloc)) {
                                totalalloc += vap->va_data_alloc;
                        } else if (VATTR_IS_SUPPORTED(vap, va_total_alloc)) {
                                totalalloc += vap->va_total_alloc;
                        }

                        ATTR_PACK8((*abp), totalalloc);
                        abp->actual.fileattr |= ATTR_FILE_ALLOCSIZE;
                } else if (VATTR_IS_SUPPORTED(vap, va_total_alloc)) {
                        ATTR_PACK8((*abp), vap->va_total_alloc);
                        abp->actual.fileattr |= ATTR_FILE_ALLOCSIZE;
                } else if (!return_valid || pack_invalid) {
                        uint64_t zero_val = 0;

                        ATTR_PACK8((*abp), zero_val);
                }
        }
        if (alp->fileattr & ATTR_FILE_IOBLOCKSIZE) {
                if (VATTR_IS_SUPPORTED(vap, va_iosize)) {
                        ATTR_PACK4((*abp), vap->va_iosize);
                        abp->actual.fileattr |= ATTR_FILE_IOBLOCKSIZE;
                } else if (!return_valid || pack_invalid) {
                        ATTR_PACK4((*abp), 0);
                }
        }
        if (alp->fileattr & ATTR_FILE_CLUMPSIZE) {
                if (!return_valid || pack_invalid) {
                        ATTR_PACK4((*abp), 0);     /* this value is deprecated */
                        abp->actual.fileattr |= ATTR_FILE_CLUMPSIZE;
                }
        }
        if (alp->fileattr & ATTR_FILE_DEVTYPE) {
                if (vp && (vp->v_type == VCHR || vp->v_type == VBLK)) {
                        uint32_t dev;

                        if (vp->v_specinfo != NULL) {
                                dev = vp->v_specinfo->si_rdev;
                        } else if (VATTR_IS_SUPPORTED(vap, va_rdev)) {
                                dev = vap->va_rdev;
                        } else {
                                dev = 0;
                        }
                        ATTR_PACK4((*abp), dev);
                        abp->actual.fileattr |= ATTR_FILE_DEVTYPE;
                } else if (vp) {
                        ATTR_PACK4((*abp), 0);
                        abp->actual.fileattr |= ATTR_FILE_DEVTYPE;
                } else if (VATTR_IS_SUPPORTED(vap, va_rdev)) {
                        ATTR_PACK4((*abp), vap->va_rdev);
                        abp->actual.fileattr |= ATTR_FILE_DEVTYPE;
                } else if (!return_valid || pack_invalid) {
                        ATTR_PACK4((*abp), 0);
                }
        }
        /*
         * If the filesystem does not support datalength
         * or dataallocsize, then we infer that totalsize and
         * totalalloc are substitutes.
         */
        if (alp->fileattr & ATTR_FILE_DATALENGTH) {
                if (VATTR_IS_SUPPORTED(vap, va_data_size)) {
                        ATTR_PACK8((*abp), vap->va_data_size);
                        abp->actual.fileattr |= ATTR_FILE_DATALENGTH;
                } else if (VATTR_IS_SUPPORTED(vap, va_total_size)){
                        ATTR_PACK8((*abp), vap->va_total_size);
                        abp->actual.fileattr |= ATTR_FILE_DATALENGTH;
                } else if (!return_valid || pack_invalid) {
                        uint64_t zero_val = 0;
                        ATTR_PACK8((*abp), zero_val);
                }
        }
        if (alp->fileattr & ATTR_FILE_DATAALLOCSIZE) {
                if (VATTR_IS_SUPPORTED(vap, va_data_alloc)) {
                        ATTR_PACK8((*abp), vap->va_data_alloc);
                        abp->actual.fileattr |= ATTR_FILE_DATAALLOCSIZE;
                } else if (VATTR_IS_SUPPORTED(vap, va_total_alloc)){
                        ATTR_PACK8((*abp), vap->va_total_alloc);
                        abp->actual.fileattr |= ATTR_FILE_DATAALLOCSIZE;
                } else if (!return_valid || pack_invalid) {
                        uint64_t zero_val = 0;
                        ATTR_PACK8((*abp), zero_val);
                }
        }
        /* already got the resource fork size/allocation above */
        if (alp->fileattr & ATTR_FILE_RSRCLENGTH) {
                if (!is_bulk) {
                        ATTR_PACK8((*abp), rlength);
                        abp->actual.fileattr |= ATTR_FILE_RSRCLENGTH;
                } else if (VATTR_IS_SUPPORTED(vap, va_rsrc_length)) {
                        ATTR_PACK8((*abp), vap->va_rsrc_length);
                        abp->actual.fileattr |= ATTR_FILE_RSRCLENGTH;
                } else if (!return_valid || pack_invalid) {
                        uint64_t zero_val = 0;

                        ATTR_PACK8((*abp), zero_val);
                }
        }
        if (alp->fileattr & ATTR_FILE_RSRCALLOCSIZE) {
                if (!is_bulk) {
                        ATTR_PACK8((*abp), ralloc);
                        abp->actual.fileattr |= ATTR_FILE_RSRCALLOCSIZE;
                } else if (VATTR_IS_SUPPORTED(vap, va_rsrc_alloc)) {
                        ATTR_PACK8((*abp), vap->va_rsrc_alloc);
                        abp->actual.fileattr |= ATTR_FILE_RSRCALLOCSIZE;
                } else if (!return_valid || pack_invalid) {
                        uint64_t zero_val = 0;

                        ATTR_PACK8((*abp), zero_val);
                }
        }
out:
        return (error);
}

/*
 * Pack FORKATTR attributes into a user buffer.
 * alp is a pointer to the bitmap of attributes required.
 * abp is the state of the attribute filling operation.
 * The attribute data (along with some other fields that are required
 * are in ad.
 */
static errno_t
attr_pack_common_extended(struct vnode *vp, struct attrlist *alp,
                struct _attrlist_buf *abp, const char *relpathptr, ssize_t relpathlen,
                struct vnode_attr *vap, int return_valid, int pack_invalid)
{
        if (vp && (alp->forkattr & ATTR_CMNEXT_RELPATH)) {
                attrlist_pack_string(abp, relpathptr, relpathlen);
                abp->actual.forkattr |= ATTR_CMNEXT_RELPATH;
        }

        if (alp->forkattr & ATTR_CMNEXT_PRIVATESIZE) {
                if (VATTR_IS_SUPPORTED(vap, va_private_size)) {
                        ATTR_PACK8((*abp), vap->va_private_size);
                        abp->actual.forkattr |= ATTR_CMNEXT_PRIVATESIZE;
                } else if (!return_valid || pack_invalid) {
                        uint64_t zero_val = 0;
                        ATTR_PACK8((*abp), zero_val);
                }
        }

        if (alp->forkattr & ATTR_CMNEXT_LINKID) {
                uint64_t linkid;

                if (VATTR_IS_SUPPORTED(vap, va_linkid))
                        linkid = vap->va_linkid;
                else
                        linkid = vap->va_fileid;

                ATTR_PACK8((*abp), linkid);
                abp->actual.forkattr |= ATTR_CMNEXT_LINKID;
        }

        return 0;
}

static void
vattr_get_alt_data(vnode_t vp, struct attrlist *alp, struct vnode_attr *vap,
    int return_valid, int is_bulk, vfs_context_t ctx)
{
        /*
         * There are a couple of special cases.
         * If we are after object IDs, we can make do with va_fileid.
         */
        if ((alp->commonattr &
            (ATTR_CMN_OBJID | ATTR_CMN_OBJPERMANENTID | ATTR_CMN_FILEID)) &&
            !VATTR_IS_SUPPORTED(vap, va_linkid)) {
                /* forget we wanted this */
                VATTR_CLEAR_ACTIVE(vap, va_linkid);
        }
        
        /*
         * Many filesystems don't know their parent object id.
         * If necessary, attempt to derive it from the vnode.
         */
        if ((alp->commonattr & (ATTR_CMN_PAROBJID | ATTR_CMN_PARENTID)) &&
            !VATTR_IS_SUPPORTED(vap, va_parentid) && vp && !is_bulk) {
                vnode_t dvp;

                if ((dvp = vnode_getparent(vp)) != NULLVP) {
                        struct vnode_attr lva;

                        VATTR_INIT(&lva);
                        VATTR_WANTED(&lva, va_fileid);
                        if (vnode_getattr(dvp, &lva, ctx) == 0 &&
                            VATTR_IS_SUPPORTED(vap, va_fileid)) {
                                vap->va_parentid = lva.va_fileid;
                                VATTR_SET_SUPPORTED(vap, va_parentid);
                        }
                        vnode_put(dvp);
                }
        }
        /*
         * And we can report datasize/alloc from total.
         */
        if ((alp->fileattr & ATTR_FILE_DATALENGTH) &&
            !VATTR_IS_SUPPORTED(vap, va_data_size)) {
                VATTR_CLEAR_ACTIVE(vap, va_data_size);
        }

        if ((alp->fileattr & ATTR_FILE_DATAALLOCSIZE) &&
            !VATTR_IS_SUPPORTED(vap, va_data_alloc)) {
                VATTR_CLEAR_ACTIVE(vap, va_data_alloc);
        }

        /*
         * If we don't have an encoding, go with UTF-8
         */
        if ((alp->commonattr & ATTR_CMN_SCRIPT) &&
            !VATTR_IS_SUPPORTED(vap, va_encoding) && !return_valid) {
                VATTR_RETURN(vap, va_encoding,
                    0x7e /* kTextEncodingMacUnicode */);
        }

        /*
         * If we don't have a name, we'll get one from the vnode or
         * mount point.
         */
        if ((alp->commonattr & ATTR_CMN_NAME) &&
            !VATTR_IS_SUPPORTED(vap, va_name)) {
                VATTR_CLEAR_ACTIVE(vap, va_name);
        }

        /* If va_dirlinkcount isn't supported use a default of 1. */
        if ((alp->dirattr & ATTR_DIR_LINKCOUNT) &&
            !VATTR_IS_SUPPORTED(vap, va_dirlinkcount)) {
                VATTR_RETURN(vap, va_dirlinkcount, 1);
        }
}

static errno_t
calc_varsize(vnode_t vp, struct attrlist *alp, struct vnode_attr *vap,
   ssize_t *varsizep, char *fullpathptr, ssize_t *fullpathlenp,
   char *relpathptr, ssize_t *relpathlenp, const char **vnamep,
   const char **cnpp, ssize_t *cnlp)
{
        int error = 0;

        *varsizep = 0; /* length count */
        /* We may need to fix up the name attribute if requested */
        if (alp->commonattr & ATTR_CMN_NAME) {
                if (VATTR_IS_SUPPORTED(vap, va_name)) {
                        vap->va_name[MAXPATHLEN-1] = '\0';      /* Ensure nul-termination */
                        *cnpp = vap->va_name;
                        *cnlp = strlen(*cnpp);
                } else if (vp) {
                        /* Filesystem did not support getting the name */
                        if (vnode_isvroot(vp)) {
                                if (vp->v_mount->mnt_vfsstat.f_mntonname[1] == 0x00 &&
                                                vp->v_mount->mnt_vfsstat.f_mntonname[0] == '/') {
                                        /* special case for boot volume.  Use root name when it's
                                         * available (which is the volume name) or just the mount on
                                         * name of "/".  we must do this for binary compatibility with
                                         * pre Tiger code.  returning nothing for the boot volume name
                                         * breaks installers - 3961058
                                         */
                                        *cnpp = *vnamep = vnode_getname(vp);
                                        if (*cnpp == NULL) {
                                                /* just use "/" as name */
                                                *cnpp = &vp->v_mount->mnt_vfsstat.f_mntonname[0];
                                        }
                                        *cnlp = strlen(*cnpp);
                                }
                                else {
                                        getattrlist_findnamecomp(vp->v_mount->mnt_vfsstat.f_mntonname, cnpp, cnlp);
                                }
                        } 
                        else {
                                *cnpp = *vnamep = vnode_getname(vp);
                                *cnlp = 0;
                                if (*cnpp != NULL) {
                                        *cnlp = strlen(*cnpp);
                                }
                        }
                } else {
                        *cnlp = 0;
                }
                *varsizep += roundup(*cnlp + 1, 4);
        }

        /* 
         * Compute the full path to this vnode, if necessary. This attribute is almost certainly
         * not supported by any filesystem, so build the path to this vnode at this time.
         */
        if (vp && (alp->commonattr & ATTR_CMN_FULLPATH)) {
                int len = MAXPATHLEN;
                int err;

                /* call build_path making sure NOT to use the cache-only behavior */
                err = build_path(vp, fullpathptr, len, &len, 0, vfs_context_current());
                if (err) {
                        error = err;
                        goto out;
                }
                *fullpathlenp = 0;
                if (fullpathptr){
                        *fullpathlenp = strlen(fullpathptr);
                }
                *varsizep += roundup(((*fullpathlenp) + 1), 4);
        }

        /*
         * Compute this vnode's volume relative path.
         */
        if (vp && (alp->forkattr & ATTR_CMNEXT_RELPATH)) {
                int len;
                int err;

                /* call build_path making sure NOT to use the cache-only behavior */
                err = build_path(vp, relpathptr, MAXPATHLEN, &len, BUILDPATH_VOLUME_RELATIVE, vfs_context_current());
                if (err) {
                        error = err;
                        goto out;
                }

                //`len' includes trailing null
                *relpathlenp = len - 1;
                *varsizep += roundup(len, 4);
        }

        /*
         * We have a kauth_acl_t but we will be returning a kauth_filesec_t.
         *
         * XXX This needs to change at some point; since the blob is opaque in
         * user-space this is OK.
         */
        if ((alp->commonattr & ATTR_CMN_EXTENDED_SECURITY) &&
                        VATTR_IS_SUPPORTED(vap, va_acl) &&
                        (vap->va_acl != NULL)) {

                /* 
                 * Since we have a kauth_acl_t (not a kauth_filesec_t), we have to check against
                 * KAUTH_FILESEC_NOACL ourselves
                 */ 
                if (vap->va_acl->acl_entrycount == KAUTH_FILESEC_NOACL) {
                        *varsizep += roundup((KAUTH_FILESEC_SIZE(0)), 4);
                }
                else {
                        *varsizep += roundup ((KAUTH_FILESEC_SIZE(vap->va_acl->acl_entrycount)), 4);
                }
        }

out:
        return (error);
}

static errno_t
vfs_attr_pack_internal(vnode_t vp, uio_t auio, struct attrlist *alp,
    uint64_t options, struct vnode_attr *vap, __unused void *fndesc,
    vfs_context_t ctx, int is_bulk, enum vtype vtype, ssize_t fixedsize)
{
        struct _attrlist_buf ab;
        ssize_t buf_size;
        size_t copy_size;
        ssize_t varsize;
        const char *vname = NULL;
        const char *cnp;
        ssize_t cnl;
        char *fullpathptr;
        ssize_t fullpathlen;
        char *relpathptr;
        ssize_t relpathlen;
        int error;
        int proc_is64;
        int return_valid;
        int pack_invalid;
        int alloc_local_buf;
        const int use_fork = options & FSOPT_ATTR_CMN_EXTENDED;

        proc_is64 = proc_is64bit(vfs_context_proc(ctx));
        ab.base = NULL;
        cnp = "unknown";
        cnl = 0;
        fullpathptr = NULL;
        fullpathlen = 0;
        relpathptr = NULL;
        relpathlen = 0;
        error = 0;
        alloc_local_buf = 0;

        buf_size = (ssize_t)uio_resid(auio);
        if ((buf_size <= 0) || (uio_iovcnt(auio) > 1))
                return (EINVAL);

        copy_size = 0;
        /* Check for special packing semantics */
        return_valid = (alp->commonattr & ATTR_CMN_RETURNED_ATTRS) ? 1 : 0;
        pack_invalid = (options & FSOPT_PACK_INVAL_ATTRS) ? 1 : 0;

        if (pack_invalid) {
                /* Generate a valid mask for post processing */
                bcopy(&(alp->commonattr), &ab.valid, sizeof (attribute_set_t));
        }

        /* did we ask for something the filesystem doesn't support? */
        if (vap->va_active && !VATTR_ALL_SUPPORTED(vap)) {
                vattr_get_alt_data(vp, alp, vap, return_valid, is_bulk,
                    ctx);

                /* check again */
                if (!VATTR_ALL_SUPPORTED(vap)) {
                        if (return_valid && pack_invalid) {
                                /* Fix up valid mask for post processing */
                                getattrlist_fixupattrs(&ab.valid, vap, use_fork);
                                        
                                /* Force packing of everything asked for */
                                vap->va_supported = vap->va_active;
                        } else if (return_valid) {
                                /* Adjust the requested attributes */
                                getattrlist_fixupattrs(
                                    (attribute_set_t *)&(alp->commonattr), vap, use_fork);
                        } else {
                                error = EINVAL;
                        }
                }

                if (error)
                        goto out;
        }

        //if a path is requested, allocate a temporary buffer to build it
        if (vp && (alp->commonattr & (ATTR_CMN_FULLPATH))) {
                fullpathptr = (char*) kalloc(MAXPATHLEN);
                if (fullpathptr == NULL) {
                        error = ENOMEM;
                        VFS_DEBUG(ctx,vp, "ATTRLIST - ERROR: cannot allocate fullpath buffer");
                        goto out;
                }
                bzero(fullpathptr, MAXPATHLEN);
        }

        // only interpret fork attributes if they're used as new common attributes
        if (vp && use_fork && (alp->forkattr & (ATTR_CMNEXT_RELPATH))) {
                relpathptr = (char*) kalloc(MAXPATHLEN);
                if (relpathptr == NULL) {
                        error = ENOMEM;
                        VFS_DEBUG(ctx,vp, "ATTRLIST - ERROR: cannot allocate relpath buffer");
                        goto out;
                }
                bzero(relpathptr, MAXPATHLEN);
        }

        /*
         * Compute variable-space requirements.
         */
        error = calc_varsize(vp, alp, vap, &varsize, fullpathptr, &fullpathlen,
                        relpathptr, &relpathlen, &vname, &cnp, &cnl);
        if (error)
                goto out;

        /*
         * Allocate a target buffer for attribute results.
         *
         * Note that we won't ever copy out more than the caller requested, even though
         * we might have to allocate more than they offer so that the diagnostic checks
         * don't result in a panic if the caller's buffer is too small..
         */
        ab.allocated = fixedsize + varsize;
        /* Cast 'allocated' to an unsigned to verify allocation size */
        if ( ((size_t)ab.allocated) > ATTR_MAX_BUFFER) {
                error = ENOMEM;
                VFS_DEBUG(ctx, vp, "ATTRLIST - ERROR: buffer size too large (%d limit %d)", ab.allocated, ATTR_MAX_BUFFER);
                goto out;
        }

        /*
         * Special handling for bulk calls, align to 8 (and only if enough
         * space left.
         */
        if (is_bulk) {
                if (buf_size < ab.allocated) {
                        goto out;
                } else {
                        uint32_t newlen;

                        newlen = (ab.allocated + 7) & ~0x07;
                        /* Align only if enough space for alignment */
                        if (newlen <= (uint32_t)buf_size)
                                ab.allocated = newlen;
                }
        }

        /*
         * See if we can reuse buffer passed in i.e. it is a kernel buffer
         * and big enough.
         */
        if (uio_isuserspace(auio) || (buf_size < ab.allocated)) {
                MALLOC(ab.base, char *, ab.allocated, M_TEMP,
                       M_ZERO | M_WAITOK);
                alloc_local_buf = 1;
        } else {
                /*
                 * In case this is a kernel buffer and sufficiently
                 * big, this function will try to use that buffer
                 * instead of allocating another buffer and bcopy'ing
                 * into it.
                 *
                 * The calculation below figures out where to start
                 * writing in the buffer and once all the data has been
                 * filled in, uio_resid is updated to reflect the usage
                 * of the buffer.
                 *
                 * uio_offset cannot be used here to determine the
                 * starting location as uio_offset could be set to a
                 * value which has nothing to do the location
                 * in the buffer.
                 */
                ab.base = (char *)uio_curriovbase(auio) +
                    ((ssize_t)uio_curriovlen(auio) - buf_size);
                bzero(ab.base, ab.allocated);
        }

        if (ab.base == NULL) {
                error = ENOMEM;
                VFS_DEBUG(ctx, vp, "ATTRLIST - ERROR: could not allocate %d for copy buffer", ab.allocated);
                goto out;
        }


        /* set the S_IFMT bits for the mode */
        if (alp->commonattr & ATTR_CMN_ACCESSMASK) {
                if (vp) {
                        switch (vp->v_type) {
                        case VREG:
                                vap->va_mode |= S_IFREG;
                                break;
                        case VDIR:
                                vap->va_mode |= S_IFDIR;
                                break;
                        case VBLK:
                                vap->va_mode |= S_IFBLK;
                                break;
                        case VCHR:
                                vap->va_mode |= S_IFCHR;
                                break;
                        case VLNK:
                                vap->va_mode |= S_IFLNK;
                                break;
                        case VSOCK:
                                vap->va_mode |= S_IFSOCK;
                                break;
                        case VFIFO:
                                vap->va_mode |= S_IFIFO;
                                break;
                        default:
                                error = EBADF;
                                goto out;
                        }
                }
        }

        /*
         * Pack results into the destination buffer.
         */
        ab.fixedcursor = ab.base + sizeof(uint32_t);
        if (return_valid) {
                ab.fixedcursor += sizeof (attribute_set_t);
                bzero(&ab.actual, sizeof (ab.actual));
        }
        ab.varcursor = ab.base + fixedsize;
        ab.needed = ab.allocated;

        /* common attributes ************************************************/
        error = attr_pack_common(ctx, vp, alp, &ab, vap, proc_is64, cnp, cnl,
            fullpathptr, fullpathlen, return_valid, pack_invalid, vtype, is_bulk);

        /* directory attributes *********************************************/
        if (!error && alp->dirattr && (vtype == VDIR)) {
                error = attr_pack_dir(vp, alp, &ab, vap, return_valid, pack_invalid);
        }

        /* file attributes **************************************************/
        if (!error && alp->fileattr && (vtype != VDIR)) {
                error = attr_pack_file(ctx, vp, alp, &ab, vap, return_valid,
                    pack_invalid, is_bulk);
        }

        /* common extended attributes *****************************************/
        if (!error && use_fork) {
                error = attr_pack_common_extended(vp, alp, &ab, relpathptr, relpathlen,
                    vap, return_valid, pack_invalid);
        }

        if (error)
                goto out;
        
        /* diagnostic */
        if (!return_valid && (ab.fixedcursor - ab.base) != fixedsize)
                panic("packed field size mismatch; allocated %ld but packed %ld for common %08x vol %08x",
                    fixedsize, (long) (ab.fixedcursor - ab.base), alp->commonattr, alp->volattr);
        if (!return_valid && ab.varcursor != (ab.base + ab.needed))
                panic("packed variable field size mismatch; used %ld but expected %ld", (long) (ab.varcursor - ab.base), ab.needed);

        /*
         * In the compatible case, we report the smaller of the required and returned sizes.
         * If the FSOPT_REPORT_FULLSIZE option is supplied, we report the full (required) size
         * of the result buffer, even if we copied less out.  The caller knows how big a buffer
         * they gave us, so they can always check for truncation themselves.
         */
        *(uint32_t *)ab.base = (options & FSOPT_REPORT_FULLSIZE) ? ab.needed : imin(ab.allocated, ab.needed);

        /* Return attribute set output if requested. */
        if (return_valid) {
                ab.actual.commonattr |= ATTR_CMN_RETURNED_ATTRS;
                if (pack_invalid) {
                        /* Only report the attributes that are valid */
                        ab.actual.commonattr &= ab.valid.commonattr;
                        ab.actual.dirattr &= ab.valid.dirattr;
                        ab.actual.fileattr &= ab.valid.fileattr;
                }
                bcopy(&ab.actual, ab.base + sizeof(uint32_t), sizeof (ab.actual));
        }

        copy_size = imin(buf_size, ab.allocated);

        /* Only actually copyout as much out as the user buffer can hold */
        if (alloc_local_buf) {
                error = uiomove(ab.base, copy_size, auio);
        } else {
                off_t orig_offset = uio_offset(auio);

                /*
                 * The buffer in the uio struct was used directly
                 * (i.e. it was a kernel buffer and big enough
                 * to hold the data required) in order to avoid
                 * un-needed allocation and copies.
                 *
                 * At this point, update the resid value to what it
                 * would be if this was the result of a uiomove. The
                 * offset is also incremented, though it may not
                 * mean anything to the caller but that is what
                 * uiomove does as well.
                 */
                uio_setresid(auio, buf_size - copy_size);
                uio_setoffset(auio, orig_offset + (off_t)copy_size);
        }

out:
        if (vname)
                vnode_putname(vname);
        if (fullpathptr)
                kfree(fullpathptr, MAXPATHLEN);
        if (relpathptr)
                kfree(relpathptr, MAXPATHLEN);
        if (ab.base != NULL && alloc_local_buf)
                FREE(ab.base, M_TEMP);
        return (error);
}

errno_t
vfs_attr_pack(vnode_t vp, uio_t uio, struct attrlist *alp, uint64_t options,
    struct vnode_attr *vap, __unused void *fndesc, vfs_context_t ctx)
{
        int error;
        ssize_t fixedsize;
        uint64_t orig_active;
        struct attrlist orig_al;
        enum vtype v_type;

        if (vp)
                v_type = vnode_vtype(vp);
        else
                v_type = vap->va_objtype;

        orig_al = *alp;
        orig_active = vap->va_active;
        vap->va_active = 0;

        error = getattrlist_setupvattr_all(alp, vap, v_type, &fixedsize,
            proc_is64bit(vfs_context_proc(ctx)), options & FSOPT_ATTR_CMN_EXTENDED);

        if (error) {
                VFS_DEBUG(ctx, vp,
                    "ATTRLIST - ERROR: setup for request failed");
                goto out;
        }

        error = vfs_attr_pack_internal(vp, uio, alp, 
            options|FSOPT_REPORT_FULLSIZE, vap, NULL, ctx, 1, v_type,
            fixedsize);

        VATTR_CLEAR_SUPPORTED_ALL(vap);
        vap->va_active = orig_active;
        *alp = orig_al;
out:
        return (error);
}

/*
 * Obtain attribute information about a filesystem object.
 *
 * Note: The alt_name parameter can be used by the caller to pass in the vnode
 * name obtained from some authoritative source (eg. readdir vnop); where
 * filesystems' getattr vnops do not support ATTR_CMN_NAME, the alt_name will be
 * used as the ATTR_CMN_NAME attribute returned in vnode_attr.va_name.
 * 
 */
static int
getattrlist_internal(vfs_context_t ctx, vnode_t vp, struct attrlist  *alp,
    user_addr_t attributeBuffer, size_t bufferSize, uint64_t options,
    enum uio_seg segflg, char* alt_name, struct ucred *file_cred)
{
        struct vnode_attr va;
        kauth_action_t  action;
        ssize_t         fixedsize;
        char            *va_name;
        int             proc_is64;
        int             error;
        int             return_valid;
        int             pack_invalid;
        int             vtype = 0;
        uio_t           auio;
        char uio_buf[ UIO_SIZEOF(1)];
        // must be true for fork attributes to be used as new common attributes
        const int use_fork = (options & FSOPT_ATTR_CMN_EXTENDED) != 0;

        proc_is64 = proc_is64bit(vfs_context_proc(ctx));

        if (segflg == UIO_USERSPACE) {
                if (proc_is64)
                        segflg = UIO_USERSPACE64;
                else
                        segflg = UIO_USERSPACE32;
        }
        auio = uio_createwithbuffer(1, 0, segflg, UIO_READ,
                    &uio_buf[0], sizeof(uio_buf));
        uio_addiov(auio, attributeBuffer, bufferSize);

        VATTR_INIT(&va);
        va_name = NULL;

        if (alp->bitmapcount != ATTR_BIT_MAP_COUNT) {
                error = EINVAL;
                goto out;
        }

        VFS_DEBUG(ctx, vp, "%p  ATTRLIST - %s request common %08x vol %08x file %08x dir %08x fork %08x %sfollow on '%s'",
            vp, p->p_comm, alp->commonattr, alp->volattr, alp->fileattr, alp->dirattr, alp->forkattr,
            (options & FSOPT_NOFOLLOW) ? "no":"", vp->v_name);

#if CONFIG_MACF
        error = mac_vnode_check_getattrlist(ctx, vp, alp);
        if (error)
                goto out;
#endif /* MAC */

        /*
         * It is legal to request volume or file attributes, but not both.
         *
         * 26903449 fork attributes can also be requested, but only if they're
         * interpreted as new, common attributes
         */
        if (alp->volattr) {
                if (alp->fileattr || alp->dirattr || (alp->forkattr && !use_fork)) {
                        error = EINVAL;
                        VFS_DEBUG(ctx, vp, "ATTRLIST - ERROR: mixed volume/file/directory attributes");
                        goto out;
                }
                /* handle volume attribute request */
                error = getvolattrlist(ctx, vp, alp, attributeBuffer,
                                       bufferSize, options, segflg, proc_is64);
                goto out;
        }

        /*
         * ATTR_CMN_GEN_COUNT and ATTR_CMN_DOCUMENT_ID reuse the bits
         * originally allocated to ATTR_CMN_NAMEDATTRCOUNT and
         * ATTR_CMN_NAMEDATTRLIST.
         */
        if ((alp->commonattr & (ATTR_CMN_GEN_COUNT | ATTR_CMN_DOCUMENT_ID)) &&
            !(options & FSOPT_ATTR_CMN_EXTENDED)) {
                error = EINVAL;
                goto out;
        }

        /* common extended attributes require FSOPT_ATTR_CMN_EXTENDED option */
        if (!(use_fork) && (alp->forkattr & ATTR_CMNEXT_VALIDMASK)) {
                error = EINVAL;
                goto out;
        }

        /* FSOPT_ATTR_CMN_EXTENDED requires forkattrs are not referenced */
        if ((options & FSOPT_ATTR_CMN_EXTENDED) && (alp->forkattr & (ATTR_FORK_VALIDMASK))) {
                error = EINVAL;
                goto out;
        }

        /* Check for special packing semantics */
        return_valid = (alp->commonattr & ATTR_CMN_RETURNED_ATTRS) ? 1 : 0;
        pack_invalid = (options & FSOPT_PACK_INVAL_ATTRS) ? 1 : 0;
        if (pack_invalid) {
                /* FSOPT_PACK_INVAL_ATTRS requires ATTR_CMN_RETURNED_ATTRS */
                if (!return_valid || (alp->forkattr && !use_fork)) {
                        error = EINVAL;
                        goto out;
                }
                /* Keep invalid attrs from being uninitialized */
                bzero(&va, sizeof (va));
        }

        /* Pick up the vnode type.  If the FS is bad and changes vnode types on us, we
         * will have a valid snapshot that we can work from here.
         */
        vtype = vp->v_type;

        /*
         * Set up the vnode_attr structure and authorise.
         */
        if ((error = getattrlist_setupvattr(alp, &va, &fixedsize, &action, proc_is64, (vtype == VDIR), use_fork)) != 0) {
                VFS_DEBUG(ctx, vp, "ATTRLIST - ERROR: setup for request failed");
                goto out;
        }
        if ((error = vnode_authorize(vp, NULL, action, ctx)) != 0) {
                VFS_DEBUG(ctx, vp, "ATTRLIST - ERROR: authorisation failed/denied");
                goto out;
        }


        if (va.va_active != 0) {
                uint64_t va_active = va.va_active;

                /*
                 * If we're going to ask for va_name, allocate a buffer to point it at
                 */
                if (VATTR_IS_ACTIVE(&va, va_name)) {
                        MALLOC_ZONE(va_name, char *, MAXPATHLEN, M_NAMEI,
                            M_WAITOK);
                        if (va_name == NULL) {
                                error = ENOMEM;
                                VFS_DEBUG(ctx, vp, "ATTRLIST - ERROR: cannot allocate va_name buffer");
                                goto out;
                        }
                }

                va.va_name = va_name;

                /*
                 * Call the filesystem.
                 */
                if ((error = vnode_getattr(vp, &va, ctx)) != 0) {
                        VFS_DEBUG(ctx, vp, "ATTRLIST - ERROR: filesystem returned %d", error);
                        goto out;
                }
#if CONFIG_MACF
                /*
                 * Give MAC polices a chance to reject or filter the
                 * attributes returned by the filesystem.  Note that MAC
                 * policies are consulted *after* calling the filesystem
                 * because filesystems can return more attributes than
                 * were requested so policies wouldn't be authoritative
                 * is consulted beforehand.  This also gives policies an
                 * opportunity to change the values of attributes
                 * retrieved.
                 */
                error = mac_vnode_check_getattr(ctx, file_cred, vp, &va);
                if (error) {
                        VFS_DEBUG(ctx, vp, "ATTRLIST - ERROR: MAC framework returned %d", error);
                        goto out;
                }
#else
                (void)file_cred;
#endif

                /* 
                 * If ATTR_CMN_NAME is not supported by filesystem and the
                 * caller has provided a name, use that.
                 * A (buggy) filesystem may change fields which belong
                 * to us. We try to deal with that here as well.
                 */
                va.va_active = va_active;
                if (alt_name  && va_name &&
                    !(VATTR_IS_SUPPORTED(&va, va_name))) {
                        strlcpy(va_name, alt_name, MAXPATHLEN);
                        VATTR_SET_SUPPORTED(&va, va_name);
                }
                va.va_name = va_name;
        }
        
        error = vfs_attr_pack_internal(vp, auio, alp, options, &va, NULL, ctx,
            0, vtype, fixedsize);

out:
        if (va_name)
                FREE_ZONE(va_name, MAXPATHLEN, M_NAMEI);
        if (VATTR_IS_SUPPORTED(&va, va_acl) && (va.va_acl != NULL))
                kauth_acl_free(va.va_acl);

        VFS_DEBUG(ctx, vp, "ATTRLIST - returning %d", error);
        return(error);
}

int
fgetattrlist(proc_t p, struct fgetattrlist_args *uap, __unused int32_t *retval)
{
        vfs_context_t ctx;
        vnode_t vp;
        int error;
        struct attrlist al;
        struct fileproc *fp;

        ctx = vfs_context_current();
        vp = NULL;
        fp = NULL;
        error = 0;

        if ((error = file_vnode(uap->fd, &vp)) != 0)
                return (error);

        if ((error = fp_lookup(p, uap->fd, &fp, 0)) != 0 ||
            (error = vnode_getwithref(vp)) != 0)
                goto out;

        /*
         * Fetch the attribute request.
         */
        error = copyin(uap->alist, &al, sizeof(al));
        if (error)
                goto out;

        /* Default to using the vnode's name. */
        error = getattrlist_internal(ctx, vp, &al, uap->attributeBuffer,
                                     uap->bufferSize, uap->options,
                                     (IS_64BIT_PROCESS(p) ? UIO_USERSPACE64 : \
                                     UIO_USERSPACE32), NULL,
                                     fp->f_fglob->fg_cred);

out:
        if (fp)
                fp_drop(p, uap->fd, fp, 0);
        if (vp)
                vnode_put(vp);
        file_drop(uap->fd);

        return error;
}

static int
getattrlistat_internal(vfs_context_t ctx, user_addr_t path,
    struct attrlist *alp, user_addr_t attributeBuffer, size_t bufferSize,
    uint64_t options, enum uio_seg segflg, enum uio_seg pathsegflg, int fd)
{
        struct nameidata nd;
        vnode_t vp;
        int32_t nameiflags;
        int error;

        nameiflags = 0;
        /*
         * Look up the file.
         */
        if (!(options & FSOPT_NOFOLLOW))
                nameiflags |= FOLLOW;

        nameiflags |= AUDITVNPATH1;
        NDINIT(&nd, LOOKUP, OP_GETATTR, nameiflags, pathsegflg,
            path, ctx);

        error = nameiat(&nd, fd);

        if (error)
                return (error);

        vp = nd.ni_vp;

        error = getattrlist_internal(ctx, vp, alp, attributeBuffer,
            bufferSize, options, segflg, NULL, NOCRED);
        
        /* Retain the namei reference until the getattrlist completes. */
        nameidone(&nd);
        vnode_put(vp);
        return (error);
}

int
getattrlist(proc_t p, struct getattrlist_args *uap, __unused int32_t *retval)
{
        enum uio_seg segflg;
        struct attrlist al;
        int error;

        segflg = IS_64BIT_PROCESS(p) ? UIO_USERSPACE64 : UIO_USERSPACE32;

        /*
         * Fetch the attribute request.
         */
        error = copyin(uap->alist, &al, sizeof(al));
        if (error)
                return error;

        return (getattrlistat_internal(vfs_context_current(),
            CAST_USER_ADDR_T(uap->path), &al,
            CAST_USER_ADDR_T(uap->attributeBuffer), uap->bufferSize,
            (uint64_t)uap->options, segflg, segflg, AT_FDCWD));
}

int
getattrlistat(proc_t p, struct getattrlistat_args *uap, __unused int32_t *retval)
{
        enum uio_seg segflg;
        struct attrlist al;
        int error;

        segflg = IS_64BIT_PROCESS(p) ? UIO_USERSPACE64 : UIO_USERSPACE32;

        /*
         * Fetch the attribute request.
         */
        error = copyin(uap->alist, &al, sizeof(al));
        if (error)
                return error;

        return (getattrlistat_internal(vfs_context_current(),
            CAST_USER_ADDR_T(uap->path), &al,
            CAST_USER_ADDR_T(uap->attributeBuffer), uap->bufferSize,
            (uint64_t)uap->options, segflg, segflg, uap->fd));
}

/*
 * This refills the per-fd direntries cache by issuing a VNOP_READDIR.
 * It attempts to try and find a size the filesystem responds to, so
 * it first tries 1 direntry sized buffer and going from 1 to 2 to 4
 * direntry sized buffers to readdir. If the filesystem does not respond
 * to 4 * direntry it returns the error by the filesystem (if any) and sets
 * EOF.
 *
 * This function also tries again if the last "refill" returned an EOF
 * to try and get any additional entries if they were added after the last
 * refill.
 */
static int
refill_fd_direntries(vfs_context_t ctx, vnode_t dvp, struct fd_vn_data *fvd,
    int *eofflagp)
{
        uio_t rdir_uio;
        char uio_buf[UIO_SIZEOF(1)];
        size_t rdirbufsiz;
        size_t rdirbufused;
        int eofflag;
        int nentries;
        int error;

        /*
         * If the last readdir returned EOF, don't try again.
         */
        if (fvd->fv_eofflag) {
                *eofflagp = 1;
                if (fvd->fv_buf) {
                        FREE(fvd->fv_buf, M_FD_DIRBUF);
                        fvd->fv_buf = NULL;
                }
                return 0;
        }

        error = 0;

        /*
         * If there is a cached allocation size of the dirbuf that should be
         * allocated, use that. Otherwise start with a allocation size of
         * FV_DIRBUF_START_SIZ. This start size may need to be increased if the
         * filesystem doesn't respond to the initial size.
         */

        if (fvd->fv_offset && fvd->fv_bufallocsiz) {
                rdirbufsiz = fvd->fv_bufallocsiz;
        } else {
                rdirbufsiz = FV_DIRBUF_START_SIZ;
        }

        *eofflagp = 0;

        rdir_uio = uio_createwithbuffer(1, 0, UIO_SYSSPACE, UIO_READ,
            &uio_buf[0], sizeof(uio_buf));

retry_alloc:
        /*
         * Don't explicitly zero out this buffer since this is
         * not copied out to user space.
         */
        if (!fvd->fv_buf) {
                MALLOC(fvd->fv_buf, caddr_t, rdirbufsiz, M_FD_DIRBUF, M_WAITOK);
                fvd->fv_bufdone = 0;
        }

        uio_reset(rdir_uio, fvd->fv_eoff, UIO_SYSSPACE, UIO_READ);
        uio_addiov(rdir_uio, CAST_USER_ADDR_T(fvd->fv_buf), rdirbufsiz);

        /*
         * Some filesystems do not set nentries or eofflag...
         */
        eofflag = 0;
        nentries = 0;
        error = vnode_readdir64(dvp, rdir_uio, VNODE_READDIR_EXTENDED,
            &eofflag, &nentries, ctx);

        rdirbufused = rdirbufsiz - (size_t)uio_resid(rdir_uio);

        if (!error && (rdirbufused > 0) && (rdirbufused <= rdirbufsiz)) {
                /* Save offsets */
                fvd->fv_soff = fvd->fv_eoff;
                fvd->fv_eoff = uio_offset(rdir_uio);
                 /* Save eofflag state but don't return EOF for this time.*/
                fvd->fv_eofflag = eofflag;
                eofflag = 0;
                 /* Reset buffer parameters */
                fvd->fv_bufsiz = rdirbufused;
                fvd->fv_bufdone = 0;
                bzero(fvd->fv_buf + rdirbufused, rdirbufsiz - rdirbufused);
                /* Cache allocation size the Filesystem responded to */
                fvd->fv_bufallocsiz = rdirbufsiz;
        } else if (!eofflag && (rdirbufsiz < FV_DIRBUF_MAX_SIZ)) {
                /*
                 * Some Filesystems have higher requirements for the
                 * smallest buffer size they will respond to for a
                 * directory listing. Start (relatively) small but increase
                 * it upto FV_DIRBUF_MAX_SIZ. Most should be good with
                 * 1*direntry. Cache the size found so that this does not need
                 * need to be done every time. This also means that an error
                 * from VNOP_READDIR is ignored until at least FV_DIRBUF_MAX_SIZ
                 * has been attempted.
                 */
                FREE(fvd->fv_buf, M_FD_DIRBUF);
                fvd->fv_buf = NULL;
                rdirbufsiz = 2 * rdirbufsiz;
                fvd->fv_bufallocsiz = 0;
                goto retry_alloc;
        } else if (!error) {
                /*
                 * The Filesystem did not set eofflag but also did not
                 * return any entries (or an error). It is presumed that
                 * EOF has been reached.
                 */
                fvd->fv_eofflag = eofflag = 1;
        }

        /*
         * If the filesystem returned an error and it had previously returned
         * EOF, ignore the error and set EOF.
         */
        if (error && fvd->fv_eofflag) {
                eofflag = 1;
                error = 0;
        }

        /*
         * If either the directory has either hit EOF or an error, now is a good
         * time to free up directory entry buffer.
         */
        if ((error || eofflag) && fvd->fv_buf) {
                FREE(fvd->fv_buf, M_FD_DIRBUF);
                fvd->fv_buf = NULL;
        }

        *eofflagp = eofflag;

        return (error);
}

/*
 * gets the current direntry. To advance to the next direntry this has to be
 * paired with a direntry_done.
 *
 * Since directories have restrictions on where directory enumeration
 * can restart from, entries are first read into* a per fd diectory entry
 * "cache" and entries provided from that cache.
 */
static int
get_direntry(vfs_context_t ctx, vnode_t dvp, struct fd_vn_data *fvd,
    int *eofflagp, struct direntry **dpp)
{
        int eofflag;
        int error;

        *eofflagp = 0;
        *dpp = NULL;
        error = 0;
        if (!fvd->fv_bufsiz) {
                error = refill_fd_direntries(ctx, dvp, fvd, &eofflag);
                if (error) {
                        return (error);
                }
                if (eofflag) {
                        *eofflagp = eofflag;
                        return (error);
                }
        }

        *dpp = (struct direntry *)(fvd->fv_buf + fvd->fv_bufdone);
        return (error);
}

/*
 * Advances to the next direntry.
 */
static void
direntry_done(struct fd_vn_data *fvd)
{
        struct direntry *dp;

        dp = (struct direntry *)(fvd->fv_buf + fvd->fv_bufdone);
        if (dp->d_reclen) {
                fvd->fv_bufdone += dp->d_reclen;
                if (fvd->fv_bufdone > fvd->fv_bufsiz) {
                        fvd->fv_bufdone = fvd->fv_bufsiz;
                }
        } else {
                fvd->fv_bufdone = fvd->fv_bufsiz;
        }

        /*
         * If we're at the end the fd direntries cache, reset the
         * cache trackers.
         */
        if (fvd->fv_bufdone == fvd->fv_bufsiz) {
                fvd->fv_bufdone = 0;
                fvd->fv_bufsiz = 0;
        }
}

/*
 *  A stripped down version of getattrlist_internal to fill in only select
 *  attributes in case of an error from getattrlist_internal.
 *
 *  It always returns at least ATTR_BULK_REQUIRED i.e. the name (but may also
 *  return some other attributes which can be obtained from the vnode).
 *
 *  It does not change the value of the passed in attrlist.
 *
 *  The objective of this function is to fill in an "error entry", i.e.
 *  an entry with ATTR_CMN_RETURNED_ATTRS & ATTR_CMN_NAME. If the caller
 *  has also asked for ATTR_CMN_ERROR, it is filled in as well.
 *
 *  Input
 *       vp - vnode pointer
 *       alp - pointer to attrlist struct.
 *       options - options passed to getattrlistbulk(2)
 *       kern_attr_buf - Kernel buffer to fill data (assumes offset 0 in
 *           buffer)
 *       kern_attr_buf_siz - Size of buffer.
 *       needs_error_attr - Whether the caller asked for ATTR_CMN_ERROR
 *       error_attr - This value is used to fill ATTR_CMN_ERROR (if the user
 *                  has requested it in the attribute list.
 *       namebuf - This is used to fill in the name.
 *       ctx - vfs context of caller.
 */
static void
get_error_attributes(vnode_t vp, struct attrlist *alp, uint64_t options,
    user_addr_t kern_attr_buf, size_t kern_attr_buf_siz, int error_attr,
    caddr_t namebuf, vfs_context_t ctx)
{
        size_t fsiz, vsiz;
        struct _attrlist_buf ab;
        int namelen;
        kauth_action_t action;
        struct attrlist al;
        int needs_error_attr = (alp->commonattr & ATTR_CMN_ERROR);

        /*
         * To calculate fixed size required, in the FSOPT_PACK_INVAL_ATTRS case,
         * the fixedsize should include space for all the attributes asked by
         * the user. Only ATTR_BULK_REQUIRED (and ATTR_CMN_ERROR) will be filled
         * and will be valid. All other attributes are zeroed out later.
         *
         * ATTR_CMN_RETURNED_ATTRS, ATTR_CMN_ERROR and ATTR_CMN_NAME
         * (the only valid ones being returned from here) happen to be
         * the first three attributes by order as well.
         */
        al = *alp;
        if (!(options & FSOPT_PACK_INVAL_ATTRS)) {
                /*
                 * In this case the fixedsize only needs to be only for the
                 * attributes being actually returned.
                 */
                al.commonattr = ATTR_BULK_REQUIRED;
                if (needs_error_attr) {
                        al.commonattr |= ATTR_CMN_ERROR;
                }
                al.fileattr = 0;
                al.dirattr = 0;
        }

        /*
         * Passing NULL for the vnode_attr pointer is valid for
         * getattrlist_setupvattr. All that is required is the size.
         */
        fsiz = 0;
        (void)getattrlist_setupvattr(&al, NULL, (ssize_t *)&fsiz,
            &action, proc_is64bit(vfs_context_proc(ctx)),
            (vnode_vtype(vp) == VDIR), (options & FSOPT_ATTR_CMN_EXTENDED));

        namelen = strlen(namebuf);
        vsiz = namelen + 1;
        vsiz = ((vsiz + 3) & ~0x03);

        bzero(&ab, sizeof(ab));
        ab.base = (char *)kern_attr_buf;
        ab.needed = fsiz + vsiz;

        /* Fill in the size needed */
        *((uint32_t *)ab.base) = ab.needed;
        if (ab.needed > (ssize_t)kern_attr_buf_siz) {
                goto out;
        }

        /*
         * Setup to pack results into the destination buffer.
         */
        ab.fixedcursor = ab.base + sizeof(uint32_t);
        /*
         * Zero out buffer, ab.fixedbuffer starts after the first uint32_t
         * which gives the length. This ensures everything that we don't
         * fill in explicitly later is zeroed out correctly.
         */
        bzero(ab.fixedcursor, fsiz);
        /*
         * variable size data should start after all the fixed
         * size data.
         */
        ab.varcursor = ab.base + fsiz;
        /*
         * Initialise the value for ATTR_CMN_RETURNED_ATTRS and leave space
         * Leave space for filling in its value here at the end.
         */
        bzero(&ab.actual, sizeof (ab.actual));
        ab.fixedcursor += sizeof (attribute_set_t);

        ab.allocated = ab.needed;

        /* Fill ATTR_CMN_ERROR (if asked for) */
        if (needs_error_attr) {
                ATTR_PACK4(ab, error_attr);
                ab.actual.commonattr |= ATTR_CMN_ERROR;
        }

        /*
         * Fill ATTR_CMN_NAME, The attrrefrence is packed at this location
         * but the actual string itself is packed after fixedsize which set
         * to different lengths based on whether FSOPT_PACK_INVAL_ATTRS
         * was passed.
         */
        attrlist_pack_string(&ab, namebuf, namelen);

        /*
         * Now Fill in ATTR_CMN_RETURNED_ATTR. This copies to a
         * location after the count i.e. before ATTR_CMN_ERROR and
         * ATTR_CMN_NAME.
         */
        ab.actual.commonattr |= ATTR_CMN_NAME | ATTR_CMN_RETURNED_ATTRS;
        bcopy(&ab.actual, ab.base + sizeof(uint32_t), sizeof (ab.actual));
out:
        return;
}

/*
 * This is the buffer size required to return at least 1 entry. We need space
 * for the length, for ATTR_CMN_RETURNED_ATTRS and ATTR_CMN_NAME. Assuming the
 * smallest filename of a single byte we get
 */

#define MIN_BUF_SIZE_REQUIRED  (sizeof(uint32_t) + sizeof(attribute_set_t) +\
    sizeof(attrreference_t))

/*
 * Read directory entries and get attributes filled in for each directory
 */
static int
readdirattr(vnode_t dvp, struct fd_vn_data *fvd, uio_t auio,
    struct attrlist *alp, uint64_t options, int *count, int *eofflagp,
    vfs_context_t ctx)
{
        caddr_t kern_attr_buf;
        size_t kern_attr_buf_siz;
        caddr_t max_path_name_buf = NULL;
        int error = 0;

        *count = 0;
        *eofflagp = 0;

        if (uio_iovcnt(auio) > 1) {
                return (EINVAL);
        }

        /*
         * We fill in a kernel buffer for the attributes and uiomove each
         * entry's attributes (as returned by getattrlist_internal)
         */
        kern_attr_buf_siz = uio_resid(auio);
        if (kern_attr_buf_siz > ATTR_MAX_BUFFER) {
                kern_attr_buf_siz = ATTR_MAX_BUFFER;
        } else if (kern_attr_buf_siz == 0) {
                /* Nothing to do */
                return (error);
        }

        MALLOC(kern_attr_buf, caddr_t, kern_attr_buf_siz, M_TEMP, M_WAITOK);

        while (uio_resid(auio) > (user_ssize_t)MIN_BUF_SIZE_REQUIRED) {
                struct direntry *dp;
                user_addr_t name_buffer;
                struct nameidata nd;
                vnode_t vp;
                struct attrlist al;
                size_t entlen;
                size_t bytes_left;
                size_t pad_bytes;
                ssize_t new_resid;

                /*
                 * get_direntry returns the current direntry and does not
                 * advance. A move to the next direntry only happens if
                 * direntry_done is called.
                 */
                error = get_direntry(ctx, dvp, fvd, eofflagp, &dp);
                if (error || (*eofflagp) || !dp) {
                        break;
                }

                /*
                 * skip "." and ".." (and a bunch of other invalid conditions.)
                 */
                if (!dp->d_reclen || dp->d_ino == 0 || dp->d_namlen == 0 ||
                    (dp->d_namlen == 1 && dp->d_name[0] == '.') ||
                    (dp->d_namlen == 2 && dp->d_name[0] == '.' &&
                    dp->d_name[1] == '.')) {
                        direntry_done(fvd);
                        continue;
                }

                /*
                 * try to deal with not-null terminated filenames.
                 */
                if (dp->d_name[dp->d_namlen] != '\0') {
                        if (!max_path_name_buf) {
                                MALLOC(max_path_name_buf, caddr_t, MAXPATHLEN,
                                    M_TEMP, M_WAITOK);
                        }
                        bcopy(dp->d_name, max_path_name_buf, dp->d_namlen);
                        max_path_name_buf[dp->d_namlen] = '\0';
                        name_buffer = CAST_USER_ADDR_T(max_path_name_buf);
                } else {
                        name_buffer = CAST_USER_ADDR_T(&(dp->d_name));
                }

                /*
                 * We have an iocount on the directory already.
                 * 
                 * Note that we supply NOCROSSMOUNT to the namei call as we attempt to acquire
                 * a vnode for this particular entry.  This is because the native call will
                 * (likely) attempt to emit attributes based on its own metadata in order to avoid
                 * creating vnodes where posssible.  If the native call is not going to  walk
                 * up the vnode mounted-on chain in order to find the top-most mount point, then we
                 * should not either in this emulated readdir+getattrlist() approach.  We  
                 * will be responsible for setting DIR_MNTSTATUS_MNTPOINT on that directory that
                 * contains a mount point.  
                 */
                NDINIT(&nd, LOOKUP, OP_GETATTR, (AUDITVNPATH1 | USEDVP | NOCROSSMOUNT), 
                    UIO_SYSSPACE, CAST_USER_ADDR_T(name_buffer), ctx);

                nd.ni_dvp = dvp;
                error = namei(&nd);

                if (error) {
                        direntry_done(fvd);
                        error = 0;
                        continue;
                }

                vp = nd.ni_vp;

                /*
                 * getattrlist_internal can change the values of the
                 * the required attribute list. Copy the current values
                 * and use that one instead.
                 */
                al = *alp;

                error = getattrlist_internal(ctx, vp, &al,
                    CAST_USER_ADDR_T(kern_attr_buf), kern_attr_buf_siz,
                    options | FSOPT_REPORT_FULLSIZE, UIO_SYSSPACE, 
                    CAST_DOWN_EXPLICIT(char *, name_buffer),
                    NOCRED);

                nameidone(&nd);

                if (error) {
                        get_error_attributes(vp, alp, options,
                            CAST_USER_ADDR_T(kern_attr_buf),
                            kern_attr_buf_siz, error, (caddr_t)name_buffer,
                            ctx);
                        error = 0;
                }

                /* Done with vnode now */
                vnode_put(vp);

                /*
                 * Because FSOPT_REPORT_FULLSIZE was set, the first 4 bytes
                 * of the buffer returned by getattrlist contains the size
                 * (even if the provided buffer isn't sufficiently big). Use
                 * that to check if we've run out of buffer space.
                 *
                 * resid is a signed type, and the size of the buffer etc
                 * are unsigned types. It is theoretically possible for
                 * resid to be < 0 and in which case we would be assigning
                 * an out of bounds value to bytes_left (which is unsigned)
                 * uiomove takes care to not ever set resid to < 0, so it
                 * is safe to do this here.
                 */
                bytes_left = (size_t)((user_size_t)uio_resid(auio));
                entlen = (size_t)(*((uint32_t *)(kern_attr_buf)));
                if (!entlen || (entlen > bytes_left)) {
                        break;
                }

                /*
                 * Will the pad bytes fit as well  ? If they can't be, still use
                 * this entry but this will be the last entry returned.
                 */
                pad_bytes = ((entlen + 7) & ~0x07) - entlen;
                new_resid = 0;
                if (pad_bytes && (entlen + pad_bytes <= bytes_left)) {
                        /*
                         * While entlen can never be > ATTR_MAX_BUFFER,
                         * (entlen + pad_bytes) can be, handle that and
                         * zero out the pad bytes. N.B. - Only zero
                         * out information in the kernel buffer that is
                         * going to be uiomove'ed out.
                         */
                        if (entlen + pad_bytes <= kern_attr_buf_siz) {
                                /* This is the normal case. */
                                bzero(kern_attr_buf + entlen, pad_bytes);
                        } else {
                                bzero(kern_attr_buf + entlen,
                                    kern_attr_buf_siz - entlen);
                                /*
                                 * Pad bytes left over, change the resid value
                                 * manually. We only got in here because
                                 * bytes_left >= entlen + pad_bytes so
                                 * new_resid (which is a signed type) is
                                 * always positive.
                                 */
                                new_resid = (ssize_t)(bytes_left -
                                    (entlen + pad_bytes));
                        }
                        entlen += pad_bytes;
                }
                *((uint32_t *)kern_attr_buf) = (uint32_t)entlen;
                error = uiomove(kern_attr_buf, min(entlen, kern_attr_buf_siz),
                    auio);

                if (error) {
                        break;
                }

                if (new_resid) {
                        uio_setresid(auio, (user_ssize_t)new_resid);
                }

                /*
                 * At this point, the directory entry has been consumed, proceed
                 * to the next one.
                 */
                (*count)++;
                direntry_done(fvd);
        }

        if (max_path_name_buf) {
                FREE(max_path_name_buf, M_TEMP);
        }

        /*
         * At this point, kern_attr_buf is always allocated
         */
        FREE(kern_attr_buf, M_TEMP);

        /*
         * Always set the offset to the last succesful offset
         * returned by VNOP_READDIR.
         */
        uio_setoffset(auio, fvd->fv_eoff);

        return (error);
}

/*
 *int getattrlistbulk(int dirfd, struct attrlist *alist, void *attributeBuffer,
 *    size_t bufferSize, uint64_t options)
 *
 * Gets directory entries alongwith their attributes in the same way
 * getattrlist does for a single file system object.
 *
 * On non error returns, retval will hold the count of entries returned.
 */
int
getattrlistbulk(proc_t p, struct getattrlistbulk_args *uap, int32_t *retval)
{
        struct attrlist al;
        vnode_t dvp;
        struct fileproc *fp;
        struct fd_vn_data *fvdata;
        vfs_context_t ctx;
        enum uio_seg segflg;
        int count;
        uio_t auio = NULL;
        char uio_buf[ UIO_SIZEOF(1) ];
        kauth_action_t action;
        int eofflag;
        uint64_t options;
        int error;

        *retval = 0;

        error = fp_getfvp(p, uap->dirfd, &fp, &dvp);
        if (error)
                return (error);

        count = 0;
        fvdata = NULL;
        eofflag = 0;
        ctx = vfs_context_current();
        segflg = IS_64BIT_PROCESS(p) ? UIO_USERSPACE64 : UIO_USERSPACE32;

        if ((fp->f_fglob->fg_flag & FREAD) == 0) {
                /*
                AUDIT_ARG(vnpath_withref, dvp, ARG_VNODE1);
                */
                error = EBADF;
                goto out;
        }

        if ((error = vnode_getwithref(dvp))) {
                dvp = NULLVP;
                goto out;
        }

        if (uap->options & FSOPT_LIST_SNAPSHOT) {
                vnode_t snapdvp;

                if (!vfs_context_issuser(ctx)) {
                        error = EPERM;
                        goto out;
                }

                if (!vnode_isvroot(dvp)) {
                        error = EINVAL;
                        goto out;
                }

                /* switch directory to snapshot directory */
                error = vnode_get_snapdir(dvp, &snapdvp, ctx);
                if (error)
                        goto out;
                vnode_put(dvp);
                dvp = snapdvp;
        }

        if (dvp->v_type != VDIR) {
                error = ENOTDIR;
                goto out;
        }

#if CONFIG_MACF
        error = mac_file_check_change_offset(vfs_context_ucred(ctx),
                                             fp->f_fglob);
        if (error)
                goto out;
#endif
        /*
         * XXX : Audit Support
         *AUDIT_ARG(vnpath, dvp, ARG_VNODE1);
         */

        options = uap->options | FSOPT_ATTR_CMN_EXTENDED;

        if ((error = copyin(CAST_USER_ADDR_T(uap->alist), &al,
            sizeof(struct attrlist)))) {
                goto out;
        }

        if (al.volattr ||
            ((al.commonattr & ATTR_BULK_REQUIRED) != ATTR_BULK_REQUIRED)) {
                error = EINVAL;
                goto out;
        }

#if CONFIG_MACF
        error = mac_vnode_check_readdir(ctx, dvp);
        if (error != 0) {
                goto out;
        }
#endif /* MAC */

        /*
         * If the only item requested is file names, we can let that past with
         * just LIST_DIRECTORY.  If they want any other attributes, that means
         * they need SEARCH as well.
         */
        action = KAUTH_VNODE_LIST_DIRECTORY;
        if ((al.commonattr & ~ATTR_CMN_NAME) || al.fileattr || al.dirattr)
                action |= KAUTH_VNODE_SEARCH;
        
        error = vnode_authorize(dvp, NULL, action, ctx);
        if (error) {
                goto out;
        }

        fvdata = (struct fd_vn_data *)fp->f_fglob->fg_vn_data;
        if (!fvdata) {
                panic("Directory expected to have fg_vn_data");
        }

        FV_LOCK(fvdata);

        /*
         * getattrlistbulk(2) maintains its offset in fv_offset. However
         * if the offset in the file glob is set (or reset) to 0, the directory
         * traversal needs to be restarted (Any existing state in the
         * directory buffer is removed as well).
         */
        if (!fp->f_fglob->fg_offset) {
                fvdata->fv_offset = 0;
                if (fvdata->fv_buf)
                        FREE(fvdata->fv_buf, M_FD_DIRBUF);
                fvdata->fv_buf = NULL;
                fvdata->fv_bufsiz = 0;
                fvdata->fv_bufdone = 0;
                fvdata->fv_soff = 0;
                fvdata->fv_eoff = 0;
                fvdata->fv_eofflag = 0;
        }

        auio = uio_createwithbuffer(1, fvdata->fv_offset, segflg, UIO_READ,
            &uio_buf[0], sizeof(uio_buf));
        uio_addiov(auio, uap->attributeBuffer, (user_size_t)uap->bufferSize);

        /*
         * For "expensive" operations in which the native VNOP implementations
         * end up having to do just as much (if not more) work than the default
         * implementation, fall back to the default implementation.
         * The VNOP helper functions depend on the filesystem providing the
         * object type, if the caller has not requested ATTR_CMN_OBJTYPE, fall
         * back to the default implementation.
         */
        if ((al.commonattr &
            (ATTR_CMN_UUID | ATTR_CMN_GRPUUID | ATTR_CMN_EXTENDED_SECURITY)) ||
            !(al.commonattr & ATTR_CMN_OBJTYPE)) {
                error = ENOTSUP;
         } else {
                struct vnode_attr va;
                char *va_name;

                if (fvdata->fv_eofflag && !fvdata->fv_buf) {
                        /*
                         * If the last successful VNOP_GETATTRLISTBULK or
                         * VNOP_READDIR returned EOF, don't try again.
                         */
                        eofflag = 1;
                        count = 0;
                        error = 0;
                } else {
                        eofflag = 0;
                        count = 0;

                        VATTR_INIT(&va);
                        MALLOC(va_name, char *, MAXPATHLEN, M_TEMP,
                            M_WAITOK | M_ZERO);
                        va.va_name = va_name;

                        (void)getattrlist_setupvattr_all(&al, &va, VNON, NULL,
                            IS_64BIT_PROCESS(p), (uap->options & FSOPT_ATTR_CMN_EXTENDED));

                        error = VNOP_GETATTRLISTBULK(dvp, &al, &va, auio, NULL,
                            options, &eofflag, &count, ctx);

                        FREE(va_name, M_TEMP);

                        /*
                         * cache state of eofflag.
                         */
                        if (!error) {
                                fvdata->fv_eofflag = eofflag;
                        }
                }
        }

        /*
         * If the Filessytem does not natively support getattrlistbulk,
         * do the default implementation.
         */
        if (error == ENOTSUP) {
                eofflag = 0;
                count = 0;

                error = readdirattr(dvp, fvdata, auio, &al, options,
                    &count, &eofflag, ctx);
        }

        if (count) {
                fvdata->fv_offset = uio_offset(auio);
                fp->f_fglob->fg_offset = fvdata->fv_offset;
                *retval = count;
                error = 0;
        } else if (!error && !eofflag) {
                /*
                 * This just means the buffer was too small to fit even a
                 * single entry.
                 */
                error = ERANGE;
        }

        FV_UNLOCK(fvdata);
out:
        if (dvp) {
                vnode_put(dvp);
        }

        file_drop(uap->dirfd);

        return (error);
}

static int
attrlist_unpack_fixed(char **cursor, char *end, void *buf, ssize_t size)
{
        /* make sure we have enough source data */
        if ((*cursor) + size > end)
                return(EINVAL);

        bcopy(*cursor, buf, size);
        *cursor += size;
        return(0);
}

#define ATTR_UNPACK(v)          do {if ((error = attrlist_unpack_fixed(&cursor, bufend, &v, sizeof(v))) != 0) goto out;} while(0);
#define ATTR_UNPACK_CAST(t, v)  do { t _f; ATTR_UNPACK(_f); v = _f;} while(0)
#define ATTR_UNPACK_TIME(v, is64)                               \
        do {                                                    \
                if (is64) {                                     \
                        struct user64_timespec us;              \
                        ATTR_UNPACK(us);                        \
                        v.tv_sec = us.tv_sec;                   \
                        v.tv_nsec = us.tv_nsec;                 \
                } else {                                        \
                        struct user32_timespec us;              \
                        ATTR_UNPACK(us);                        \
                        v.tv_sec = us.tv_sec;                   \
                        v.tv_nsec = us.tv_nsec;                 \
                }                                               \
        } while(0)


/*
 * Write attributes.
 */
static int
setattrlist_internal(vnode_t vp, struct setattrlist_args *uap, proc_t p, vfs_context_t ctx)
{
        struct attrlist al;
        struct vnode_attr va;
        struct attrreference ar;
        kauth_action_t  action;
        char            *user_buf, *cursor, *bufend, *fndrinfo, *cp, *volname;
        int             proc_is64, error;
        uint32_t        nace;
        kauth_filesec_t rfsec;

        user_buf = NULL;
        fndrinfo = NULL;
        volname = NULL;
        error = 0;
        proc_is64 = proc_is64bit(p);
        VATTR_INIT(&va);
        
        /*
         * Fetch the attribute set and validate.
         */
        if ((error = copyin(uap->alist, (caddr_t) &al, sizeof (al))))
                goto out;
        if (al.bitmapcount != ATTR_BIT_MAP_COUNT) {
                error = EINVAL;
                goto out;
        }

#if DEVELOPMENT || DEBUG
        /*
         * XXX VSWAP: Check for entitlements or special flag here
         * so we can restrict access appropriately.
         */
#else /* DEVELOPMENT || DEBUG */

        if (vnode_isswap(vp) && (ctx != vfs_context_kernel())) {
                error = EPERM;
                goto out;
        }
#endif /* DEVELOPMENT || DEBUG */

        VFS_DEBUG(ctx, vp, "%p  ATTRLIST - %s set common %08x vol %08x file %08x dir %08x fork %08x %sfollow on '%s'",
            vp, p->p_comm, al.commonattr, al.volattr, al.fileattr, al.dirattr, al.forkattr,
            (uap->options & FSOPT_NOFOLLOW) ? "no":"", vp->v_name);

        if (al.volattr) {
                if ((al.volattr & ~ATTR_VOL_SETMASK) ||
                    (al.commonattr & ~ATTR_CMN_VOLSETMASK) ||
                    al.fileattr ||
                    al.forkattr) {
                        error = EINVAL;
                        VFS_DEBUG(ctx, vp, "ATTRLIST - ERROR: attempt to set invalid volume attributes");
                        goto out;
                }
        } else {
                if ((al.commonattr & ~ATTR_CMN_SETMASK) ||
                    (al.fileattr & ~ATTR_FILE_SETMASK) ||
                    (al.dirattr & ~ATTR_DIR_SETMASK) ||
                    (al.forkattr & ~ATTR_FORK_SETMASK)) {
                        error = EINVAL;
                        VFS_DEBUG(ctx, vp, "ATTRLIST - ERROR: attempt to set invalid file/folder attributes");
                        goto out;
                }
        }

        /*
         * If the caller's bitmaps indicate that there are no attributes to set,
         * then exit early.  In particular, we want to avoid the MALLOC below
         * since the caller's bufferSize could be zero, and MALLOC of zero bytes
         * returns a NULL pointer, which would cause setattrlist to return ENOMEM.
         */
        if (al.commonattr == 0 &&
                (al.volattr & ~ATTR_VOL_INFO) == 0 &&
                al.dirattr == 0 &&
                al.fileattr == 0 &&
                al.forkattr == 0) {
                error = 0;
                goto out;
        }
                
        /*
         * Make the naive assumption that the caller has supplied a reasonable buffer
         * size.  We could be more careful by pulling in the fixed-size region, checking
         * the attrref structures, then pulling in the variable section.
         * We need to reconsider this for handling large ACLs, as they should probably be
         * brought directly into a buffer.  Multiple copyins will make this slower though.
         *
         * We could also map the user buffer if it is larger than some sensible mimimum.
         */
        if (uap->bufferSize > ATTR_MAX_BUFFER) {
                VFS_DEBUG(ctx, vp, "ATTRLIST - ERROR: buffer size %d too large", uap->bufferSize);
                error = ENOMEM;
                goto out;
        }
        MALLOC(user_buf, char *, uap->bufferSize, M_TEMP, M_WAITOK);
        if (user_buf == NULL) {
                VFS_DEBUG(ctx, vp, "ATTRLIST - ERROR: could not allocate %d bytes for buffer", uap->bufferSize);
                error = ENOMEM;
                goto out;
        }
        if ((error = copyin(uap->attributeBuffer, user_buf, uap->bufferSize)) != 0) {
                VFS_DEBUG(ctx, vp, "ATTRLIST - ERROR: buffer copyin failed");
                goto out;
        }
        VFS_DEBUG(ctx, vp, "ATTRLIST - copied in %d bytes of user attributes to %p", uap->bufferSize, user_buf);

#if CONFIG_MACF
        error = mac_vnode_check_setattrlist(ctx, vp, &al);
        if (error)
                goto out;
#endif /* MAC */

        /*
         * Unpack the argument buffer.
         */
        cursor = user_buf;
        bufend = cursor + uap->bufferSize;

        /* common */
        if (al.commonattr & ATTR_CMN_SCRIPT) {
                ATTR_UNPACK(va.va_encoding);
                VATTR_SET_ACTIVE(&va, va_encoding);
        }
        if (al.commonattr & ATTR_CMN_CRTIME) {
                ATTR_UNPACK_TIME(va.va_create_time, proc_is64);
                VATTR_SET_ACTIVE(&va, va_create_time);
        }
        if (al.commonattr & ATTR_CMN_MODTIME) {
                ATTR_UNPACK_TIME(va.va_modify_time, proc_is64);
                VATTR_SET_ACTIVE(&va, va_modify_time);
        }
        if (al.commonattr & ATTR_CMN_CHGTIME) {
                ATTR_UNPACK_TIME(va.va_change_time, proc_is64);
                al.commonattr &= ~ATTR_CMN_CHGTIME;
                /*quietly ignore change time; advisory in man page*/
        }
        if (al.commonattr & ATTR_CMN_ACCTIME) {
                ATTR_UNPACK_TIME(va.va_access_time, proc_is64);
                VATTR_SET_ACTIVE(&va, va_access_time);
        }
        if (al.commonattr & ATTR_CMN_BKUPTIME) {
                ATTR_UNPACK_TIME(va.va_backup_time, proc_is64);
                VATTR_SET_ACTIVE(&va, va_backup_time);
        }
        if (al.commonattr & ATTR_CMN_FNDRINFO) {
                if ((cursor + 32) > bufend) {
                        error = EINVAL;
                        VFS_DEBUG(ctx, vp, "ATTRLIST - not enough data supplied for FINDERINFO");
                        goto out;
                }
                fndrinfo = cursor;
                cursor += 32;
        }
        if (al.commonattr & ATTR_CMN_OWNERID) {
                ATTR_UNPACK(va.va_uid);
                VATTR_SET_ACTIVE(&va, va_uid);
        }
        if (al.commonattr & ATTR_CMN_GRPID) {
                ATTR_UNPACK(va.va_gid);
                VATTR_SET_ACTIVE(&va, va_gid);
        }
        if (al.commonattr & ATTR_CMN_ACCESSMASK) {
                ATTR_UNPACK_CAST(uint32_t, va.va_mode);
                VATTR_SET_ACTIVE(&va, va_mode);
        }
        if (al.commonattr & ATTR_CMN_FLAGS) {
                ATTR_UNPACK(va.va_flags);
                VATTR_SET_ACTIVE(&va, va_flags);
#if CONFIG_MACF
                if ((error = mac_vnode_check_setflags(ctx, vp, va.va_flags)) != 0)
                        goto out;
#endif
        }
        if (al.commonattr & ATTR_CMN_EXTENDED_SECURITY) {

                /*
                 * We are (for now) passed a kauth_filesec_t, but all we want from
                 * it is the ACL.
                 */
                cp = cursor;
                ATTR_UNPACK(ar);
                if (ar.attr_dataoffset < 0) {
                        VFS_DEBUG(ctx, vp, "ATTRLIST - ERROR: bad offset supplied", ar.attr_dataoffset);
                        error = EINVAL;
                        goto out;
                }

                cp += ar.attr_dataoffset;
                rfsec = (kauth_filesec_t)cp;
                if (((((char *)rfsec) + KAUTH_FILESEC_SIZE(0)) > bufend) ||                     /* no space for acl */
                    (rfsec->fsec_magic != KAUTH_FILESEC_MAGIC) ||       /* bad magic */
                    (KAUTH_FILESEC_COPYSIZE(rfsec) != ar.attr_length) || /* size does not match */
                    ((cp + KAUTH_FILESEC_COPYSIZE(rfsec)) > bufend)) {  /* ACEs overrun buffer */
                        error = EINVAL;
                        VFS_DEBUG(ctx, vp, "ATTRLIST - ERROR: bad ACL supplied", ar.attr_length);
                        goto out;
                }
                nace = rfsec->fsec_entrycount;
                if (nace == KAUTH_FILESEC_NOACL)
                        nace = 0;
                if (nace > KAUTH_ACL_MAX_ENTRIES) {                     /* ACL size invalid */
                        error = EINVAL;
                        VFS_DEBUG(ctx, vp, "ATTRLIST - ERROR: bad ACL supplied");
                        goto out;
                }
                nace = rfsec->fsec_acl.acl_entrycount;
                if (nace == KAUTH_FILESEC_NOACL) {
                        /* deleting ACL */
                        VATTR_SET(&va, va_acl, NULL);
                } else {
                        
                        if (nace > KAUTH_ACL_MAX_ENTRIES) {                     /* ACL size invalid */
                                error = EINVAL;
                                VFS_DEBUG(ctx, vp, "ATTRLIST - ERROR: supplied ACL is too large");
                                goto out;
                        }
                        VATTR_SET(&va, va_acl, &rfsec->fsec_acl);
                }
        }
        if (al.commonattr & ATTR_CMN_UUID) {
                ATTR_UNPACK(va.va_uuuid);
                VATTR_SET_ACTIVE(&va, va_uuuid);
        }
        if (al.commonattr & ATTR_CMN_GRPUUID) {
                ATTR_UNPACK(va.va_guuid);
                VATTR_SET_ACTIVE(&va, va_guuid);
        }
        /* Support setattrlist of data protection class */
        if (al.commonattr & ATTR_CMN_DATA_PROTECT_FLAGS) {
                ATTR_UNPACK(va.va_dataprotect_class);
                VATTR_SET_ACTIVE(&va, va_dataprotect_class);
        }

        /* volume */
        if (al.volattr & ATTR_VOL_INFO) {
                if (al.volattr & ATTR_VOL_NAME) {
                        volname = cursor;
                        ATTR_UNPACK(ar);        
                        /* attr_length cannot be 0! */
                        if ((ar.attr_dataoffset < 0) || (ar.attr_length == 0) ||
                                (ar.attr_length > uap->bufferSize) ||
                                (uap->bufferSize - ar.attr_length < (unsigned)ar.attr_dataoffset)) {
                                VFS_DEBUG(ctx, vp, "ATTRLIST - ERROR: bad offset supplied (2) ", ar.attr_dataoffset);
                                error = EINVAL;
                                goto out;
                        }

                        if (volname >= bufend - ar.attr_dataoffset - ar.attr_length) {
                                error = EINVAL;
                                VFS_DEBUG(ctx, vp, "ATTRLIST - ERROR: volume name too big for caller buffer");
                                goto out;
                        }
                        volname += ar.attr_dataoffset;
                        /* guarantee NUL termination */
                        volname[ar.attr_length - 1] = 0;
                }
        }

        /* file */
        if (al.fileattr & ATTR_FILE_DEVTYPE) {
                /* XXX does it actually make any sense to change this? */
                error = EINVAL;
                VFS_DEBUG(ctx, vp, "ATTRLIST - XXX device type change not implemented");
                goto out;
        }

        /*
         * Validate and authorize.
         */
        action = 0;
        if ((va.va_active != 0LL) && ((error = vnode_authattr(vp, &va, &action, ctx)) != 0)) {
                VFS_DEBUG(ctx, vp, "ATTRLIST - ERROR: attribute changes refused: %d", error);
                goto out;
        }
        /*
         * We can auth file Finder Info here.  HFS volume FinderInfo is really boot data,
         * and will be auth'ed by the FS.
         */
        if (fndrinfo != NULL) {
                if (al.volattr & ATTR_VOL_INFO) {
                        if (vp->v_tag != VT_HFS) {
                                error = EINVAL;
                                goto out;
                        }
                } else {
                        action |= KAUTH_VNODE_WRITE_EXTATTRIBUTES;
                }
        }

        if ((action != 0) && ((error = vnode_authorize(vp, NULL, action, ctx)) != 0)) {
                VFS_DEBUG(ctx, vp, "ATTRLIST - ERROR: authorization failed");
                goto out;
        }

        /*
         * When we're setting both the access mask and the finder info, then
         * check if were about to remove write access for the owner.  Since
         * vnode_setattr and vn_setxattr invoke two separate vnops, we need
         * to consider their ordering.
         *
         * If were about to remove write access for the owner we'll set the
         * Finder Info here before vnode_setattr.  Otherwise we'll set it
         * after vnode_setattr since it may be adding owner write access.
         */
        if ((fndrinfo != NULL) && !(al.volattr & ATTR_VOL_INFO) &&
            (al.commonattr & ATTR_CMN_ACCESSMASK) && !(va.va_mode & S_IWUSR)) {
                if ((error = setattrlist_setfinderinfo(vp, fndrinfo, ctx)) != 0) {
                        goto out;
                }
                fndrinfo = NULL;  /* it was set here so skip setting below */
        }

        /*
         * Write the attributes if we have any.
         */
        if ((va.va_active != 0LL) && ((error = vnode_setattr(vp, &va, ctx)) != 0)) {
                VFS_DEBUG(ctx, vp, "ATTRLIST - ERROR: filesystem returned %d", error);
                goto out;
        }

#if CONFIG_MACF
        mac_vnode_notify_setattrlist(ctx, vp, &al);
        if (VATTR_IS_ACTIVE(&va, va_flags))
                mac_vnode_notify_setflags(ctx, vp, va.va_flags);
#endif

        /*
         * Write the Finder Info if we have any.
         */
        if (fndrinfo != NULL) {
                if (al.volattr & ATTR_VOL_INFO) {
                        if (vp->v_tag == VT_HFS) {
#define HFS_SET_BOOT_INFO   (FCNTL_FS_SPECIFIC_BASE + 0x00005)
                                error = VNOP_IOCTL(vp, HFS_SET_BOOT_INFO, (caddr_t)fndrinfo, 0, ctx);
                                if (error != 0)
                                        goto out;
                        } else {
                                /* XXX should never get here */
                        }
                } else if ((error = setattrlist_setfinderinfo(vp, fndrinfo, ctx)) != 0) {
                        goto out;
                }
        }

        /* 
         * Set the volume name, if we have one
         */
        if (volname != NULL)
        {
                struct vfs_attr vs;
                
                VFSATTR_INIT(&vs);
                
                vs.f_vol_name = volname;        /* References the setattrlist buffer directly */
                VFSATTR_WANTED(&vs, f_vol_name);
                
#if CONFIG_MACF
                error = mac_mount_check_setattr(ctx, vp->v_mount, &vs);
                if (error != 0)
                        goto out;
#endif

                if ((error = vfs_setattr(vp->v_mount, &vs, ctx)) != 0) {
                        VFS_DEBUG(ctx, vp, "ATTRLIST - ERROR: setting volume name failed");
                        goto out;
                }
                
                if (!VFSATTR_ALL_SUPPORTED(&vs)) {
                        error = EINVAL;
                        VFS_DEBUG(ctx, vp, "ATTRLIST - ERROR: could not set volume name");
                        goto out;
                }
        }

        /* all done and successful */
        
out:
        if (user_buf != NULL)
                FREE(user_buf, M_TEMP);
        VFS_DEBUG(ctx, vp, "ATTRLIST - set returning %d", error);
        return(error);
}

int
setattrlist(proc_t p, struct setattrlist_args *uap, __unused int32_t *retval)
{
        struct vfs_context *ctx;
        struct nameidata nd;
        vnode_t         vp = NULL;
        u_long          nameiflags;
        int error = 0;

        ctx = vfs_context_current();

        /*
         * Look up the file.
         */
        nameiflags = AUDITVNPATH1;
        if ((uap->options & FSOPT_NOFOLLOW) == 0)
                nameiflags |= FOLLOW;
        NDINIT(&nd, LOOKUP, OP_SETATTR, nameiflags, UIO_USERSPACE, uap->path, ctx);
        if ((error = namei(&nd)) != 0)
                goto out;
        vp = nd.ni_vp;
        nameidone(&nd);

        error = setattrlist_internal(vp, uap, p, ctx);
out:
        if (vp != NULL)
                vnode_put(vp);
        return error;
}

int
fsetattrlist(proc_t p, struct fsetattrlist_args *uap, __unused int32_t *retval)
{
        struct vfs_context *ctx;
        vnode_t         vp = NULL;
        int             error;
        struct setattrlist_args ap;

        ctx = vfs_context_current();

        if ((error = file_vnode(uap->fd, &vp)) != 0)
                return (error);

        if ((error = vnode_getwithref(vp)) != 0) {
                file_drop(uap->fd);
                return(error);
        }

        ap.path = 0;
        ap.alist = uap->alist;
        ap.attributeBuffer = uap->attributeBuffer;
        ap.bufferSize = uap->bufferSize;
        ap.options = uap->options;

        error = setattrlist_internal(vp, &ap, p, ctx);
        file_drop(uap->fd);
        if (vp != NULL)
                vnode_put(vp);

        return error;
}