/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/errno.h>
#include <sys/kmem.h>
#include <sys/t_lock.h>
#include <sys/ksynch.h>
#include <sys/buf.h>
#include <sys/vfs.h>
#include <sys/vnode.h>
#include <sys/mode.h>
#include <sys/systm.h>
#include <vm/seg.h>
#include <sys/file.h>
#include <sys/acl.h>
#include <sys/fs/ufs_inode.h>
#include <sys/fs/ufs_acl.h>
#include <sys/fs/ufs_quota.h>
#include <sys/sysmacros.h>
#include <sys/debug.h>
#include <sys/policy.h>

/* Cache routines */
static int si_signature(si_t *);
static int si_cachei_get(struct inode *, si_t **);
static int si_cachea_get(struct inode *, si_t *, si_t **);
static int si_cmp(si_t *, si_t *);
static void si_cache_put(si_t *);
void si_cache_del(si_t *, int);
void si_cache_init(void);

static void ufs_si_free_mem(si_t *);
static int ufs_si_store(struct inode *, si_t *, int, cred_t *);
static si_t *ufs_acl_cp(si_t *);
static int ufs_sectobuf(si_t *, caddr_t *, size_t *);
static int acl_count(ufs_ic_acl_t *);
static int acl_validate(aclent_t *, int, int);
static int vsecattr2aclentry(vsecattr_t *, si_t **);
static int aclentry2vsecattr(si_t *, vsecattr_t *);

krwlock_t si_cache_lock;                /* Protects si_cache */
int     si_cachecnt = 64;               /* # buckets in si_cache[a|i] */
si_t    **si_cachea;                    /* The 'by acl' cache chains */
si_t    **si_cachei;                    /* The 'by inode' cache chains */
long    si_cachehit = 0;
long    si_cachemiss = 0;

#define SI_HASH(S)      ((int)(S) & (si_cachecnt - 1))

/*
 * Store the new acls in aclp.  Attempts to make things atomic.
 * Search the acl cache for an identical sp and, if found, attach
 * the cache'd acl to ip. If the acl is new (not in the cache),
 * add it to the cache, then attach it to ip.  Last, remove and
 * decrement the reference count of any prior acl list attached
 * to the ip.
 *
 * Parameters:
 * ip - Ptr to inode to receive the acl list
 * sp - Ptr to in-core acl structure to attach to the inode.
 * puship - 0 do not push the object inode(ip) 1 push the ip
 * cr - Ptr to credentials
 *
 * Returns:     0 - Success
 *              N - From errno.h
 */
static int
ufs_si_store(struct inode *ip, si_t *sp, int puship, cred_t *cr)
{
        struct vfs      *vfsp;
        struct inode    *sip;
        si_t            *oldsp;
        si_t            *csp;
        caddr_t         acldata;
        ino_t           oldshadow;
        size_t          acldatalen;
        off_t           offset;
        int             shadow;
        int             err;
        int             refcnt;
        int             usecnt;
        int             signature;
        int             resid;
        struct ufsvfs   *ufsvfsp        = ip->i_ufsvfs;
        struct fs       *fs             = ufsvfsp->vfs_fs;

        ASSERT(RW_WRITE_HELD(&ip->i_contents));
        ASSERT(ip->i_ufs_acl != sp);

        if (!CHECK_ACL_ALLOWED(ip->i_mode & IFMT))
                return (ENOSYS);

        /*
         * if there are only the three owner/group/other then do not
         * create a shadow inode.  If there is already a shadow with
         * the file, remove it.
         *
         */
        if (!sp->ausers &&
            !sp->agroups &&
            !sp->downer &&
            !sp->dgroup &&
            !sp->dother &&
            sp->dclass.acl_ismask == 0 &&
            !sp->dusers &&
            !sp->dgroups) {
                if (ip->i_ufs_acl)
                        err = ufs_si_free(ip->i_ufs_acl, ITOV(ip)->v_vfsp, cr);
                ip->i_ufs_acl = NULL;
                ip->i_shadow = 0;
                ip->i_flag |= IMOD | IACC;
                ip->i_mode = (ip->i_smode & ~0777) |
                    ((sp->aowner->acl_ic_perm & 07) << 6) |
                    (MASK2MODE(sp)) |
                    (sp->aother->acl_ic_perm & 07);
                TRANS_INODE(ip->i_ufsvfs, ip);
                ufs_iupdat(ip, 1);
                ufs_si_free_mem(sp);
                return (0);
        }

loop:

        /*
         * Check cache. If in cache, use existing shadow inode.
         * Increment the shadow link count, then attach to the
         * cached ufs_acl_entry struct, and increment it's reference
         * count.  Then discard the passed-in ufs_acl_entry and
         * return.
         */
        if (si_cachea_get(ip, sp, &csp) == 0) {
                ASSERT(RW_WRITE_HELD(&csp->s_lock));
                if (ip->i_ufs_acl == csp) {
                        rw_exit(&csp->s_lock);
                        (void) ufs_si_free_mem(sp);
                        return (0);
                }
                vfsp = ITOV(ip)->v_vfsp;
                ASSERT(csp->s_shadow <= INT_MAX);
                shadow = (int)csp->s_shadow;
                /*
                 * We can't call ufs_iget while holding the csp locked,
                 * because we might deadlock.  So we drop the
                 * lock on csp, then go search the si_cache again
                 * to see if the csp is still there.
                 */
                rw_exit(&csp->s_lock);
                if ((err = ufs_iget(vfsp, shadow, &sip, cr)) != 0) {
                        (void) ufs_si_free_mem(sp);
                        return (EIO);
                }
                rw_enter(&sip->i_contents, RW_WRITER);
                if ((sip->i_mode & IFMT) != IFSHAD || sip->i_nlink <= 0) {
                        rw_exit(&sip->i_contents);
                        VN_RELE(ITOV(sip));
                        goto loop;
                }
                /* Get the csp again */
                if (si_cachea_get(ip, sp, &csp) != 0) {
                        rw_exit(&sip->i_contents);
                        VN_RELE(ITOV(sip));
                        goto loop;
                }
                ASSERT(RW_WRITE_HELD(&csp->s_lock));
                /* See if we got the right shadow */
                if (csp->s_shadow != shadow) {
                        rw_exit(&csp->s_lock);
                        rw_exit(&sip->i_contents);
                        VN_RELE(ITOV(sip));
                        goto loop;
                }
                ASSERT(RW_WRITE_HELD(&sip->i_contents));
                ASSERT(sip->i_dquot == 0);
                /* Increment link count */
                ASSERT(sip->i_nlink > 0);
                sip->i_nlink++;
                TRANS_INODE(ufsvfsp, sip);
                csp->s_use = sip->i_nlink;
                csp->s_ref++;
                ASSERT(sp->s_ref >= 0 && sp->s_ref <= sp->s_use);
                sip->i_flag |= ICHG | IMOD;
                sip->i_seq++;
                ITIMES_NOLOCK(sip);
                /*
                 * Always release s_lock before both releasing i_contents
                 * and calling VN_RELE.
                 */
                rw_exit(&csp->s_lock);
                rw_exit(&sip->i_contents);
                VN_RELE(ITOV(sip));
                (void) ufs_si_free_mem(sp);
                sp = csp;
                si_cachehit++;
                goto switchshadows;
        }

        /* Alloc a shadow inode and fill it in */
        err = ufs_ialloc(ip, ip->i_number, (mode_t)IFSHAD, &sip, cr);
        if (err) {
                (void) ufs_si_free_mem(sp);
                return (err);
        }
        rw_enter(&sip->i_contents, RW_WRITER);
        sip->i_flag |= IACC | IUPD | ICHG;
        sip->i_seq++;
        sip->i_mode = (o_mode_t)IFSHAD;
        ITOV(sip)->v_type = VREG;
        ufs_reset_vnode(ITOV(sip));
        sip->i_nlink = 1;
        sip->i_uid = crgetuid(cr);
        sip->i_suid = (ulong_t)sip->i_uid > (ulong_t)USHRT_MAX ?
            UID_LONG : sip->i_uid;
        sip->i_gid = crgetgid(cr);
        sip->i_sgid = (ulong_t)sip->i_gid > (ulong_t)USHRT_MAX ?
            GID_LONG : sip->i_gid;
        sip->i_shadow = 0;
        TRANS_INODE(ufsvfsp, sip);
        sip->i_ufs_acl = NULL;
        ASSERT(sip->i_size == 0);

        sp->s_shadow = sip->i_number;

        if ((err = ufs_sectobuf(sp, &acldata, &acldatalen)) != 0)
                goto errout;
        offset = 0;

        /*
         * We don't actually care about the residual count upon failure,
         * but giving ufs_rdwri() the pointer means it won't translate
         * all failures to EIO.  Our caller needs to know when ENOSPC
         * gets hit.
         */
        resid = 0;
        if (((err = ufs_rdwri(UIO_WRITE, FWRITE|FSYNC, sip, acldata,
            acldatalen, (offset_t)0, UIO_SYSSPACE, &resid, cr)) != 0) ||
            (resid != 0)) {
                kmem_free(acldata, acldatalen);
                if ((resid != 0) && (err == 0))
                        err = ENOSPC;
                goto errout;
        }

        offset += acldatalen;
        if ((acldatalen + fs->fs_bsize) > ufsvfsp->vfs_maxacl)
                ufsvfsp->vfs_maxacl = acldatalen + fs->fs_bsize;

        kmem_free(acldata, acldatalen);
        /* Sync & free the shadow inode */
        ufs_iupdat(sip, 1);
        rw_exit(&sip->i_contents);
        VN_RELE(ITOV(sip));

        /* We're committed to using this sp */
        sp->s_use = 1;
        sp->s_ref = 1;

        /* Now put the new acl stuff in the cache */
        /* XXX Might make a duplicate */
        si_cache_put(sp);
        si_cachemiss++;

switchshadows:
        /* Now switch the parent inode to use the new shadow inode */
        ASSERT(RW_WRITE_HELD(&ip->i_contents));
        rw_enter(&sp->s_lock, RW_READER);
        oldsp = ip->i_ufs_acl;
        oldshadow = ip->i_shadow;
        ip->i_ufs_acl = sp;
        ASSERT(sp->s_shadow <= INT_MAX);
        ip->i_shadow = (int32_t)sp->s_shadow;
        ASSERT(oldsp != sp);
        ASSERT(oldshadow != ip->i_number);
        ASSERT(ip->i_number != ip->i_shadow);
        /*
         * Change the mode bits to follow the acl list
         *
         * NOTE:        a directory is not required to have a "regular" acl
         *              bug id's 1238908,  1257173, 1263171 and 1263188
         *
         *              but if a "regular" acl is present, it must contain
         *              an "owner", "group", and "other" acl
         *
         *              If an ACL mask exists, the effective group rights are
         *              set to the mask.  Otherwise, the effective group rights
         *              are set to the object group bits.
         */
        if (sp->aowner) {                               /* Owner */
                ip->i_mode &= ~0700;                    /* clear Owner */
                ip->i_mode |= (sp->aowner->acl_ic_perm & 07) << 6;
                ip->i_uid = sp->aowner->acl_ic_who;
        }

        if (sp->agroup) {                               /* Group */
                ip->i_mode &= ~0070;                    /* clear Group */
                ip->i_mode |= MASK2MODE(sp);            /* apply mask */
                ip->i_gid = sp->agroup->acl_ic_who;
        }

        if (sp->aother) {                               /* Other */
                ip->i_mode &= ~0007;                    /* clear Other */
                ip->i_mode |= (sp->aother->acl_ic_perm & 07);
        }

        if (sp->aclass.acl_ismask)
                ip->i_mode = (ip->i_mode & ~070) |
                    (((sp->aclass.acl_maskbits & 07) << 3) &
                    ip->i_mode);

        TRANS_INODE(ufsvfsp, ip);
        rw_exit(&sp->s_lock);
        ip->i_flag |= ICHG;
        ip->i_seq++;
        /*
         * when creating a file there is no need to push the inode, it
         * is pushed later
         */
        if (puship == 1)
                ufs_iupdat(ip, 1);

        /*
         * Decrement link count on the old shadow inode,
         * and decrement reference count on the old aclp,
         */
        if (oldshadow) {
                /* Get the shadow inode */
                ASSERT(RW_WRITE_HELD(&ip->i_contents));
                vfsp = ITOV(ip)->v_vfsp;
                if ((err = ufs_iget_alloced(vfsp, oldshadow, &sip, cr)) != 0) {
                        return (EIO);
                }
                /* Decrement link count */
                rw_enter(&sip->i_contents, RW_WRITER);
                if (oldsp)
                        rw_enter(&oldsp->s_lock, RW_WRITER);
                ASSERT(sip->i_dquot == 0);
                ASSERT(sip->i_nlink > 0);
                usecnt = --sip->i_nlink;
                ufs_setreclaim(sip);
                TRANS_INODE(ufsvfsp, sip);
                sip->i_flag |= ICHG | IMOD;
                sip->i_seq++;
                ITIMES_NOLOCK(sip);
                if (oldsp) {
                        oldsp->s_use = usecnt;
                        refcnt = --oldsp->s_ref;
                        signature = oldsp->s_signature;
                        /*
                         * Always release s_lock before both releasing
                         * i_contents and calling VN_RELE.
                         */
                        rw_exit(&oldsp->s_lock);
                }
                rw_exit(&sip->i_contents);
                VN_RELE(ITOV(sip));
                if (oldsp && (refcnt == 0))
                        si_cache_del(oldsp, signature);
        }
        return (0);

errout:
        /* Throw the newly alloc'd inode away */
        sip->i_nlink = 0;
        ufs_setreclaim(sip);
        TRANS_INODE(ufsvfsp, sip);
        ITIMES_NOLOCK(sip);
        rw_exit(&sip->i_contents);
        VN_RELE(ITOV(sip));
        ASSERT(!sp->s_use && !sp->s_ref && !(sp->s_flags & SI_CACHED));
        (void) ufs_si_free_mem(sp);
        return (err);
}

/*
 * Load the acls for inode ip either from disk (adding to the cache),
 * or search the cache and attach the cache'd acl list to the ip.
 * In either case, maintain the proper reference count on the cached entry.
 *
 * Parameters:
 * ip - Ptr to the inode which needs the acl list loaded
 * cr - Ptr to credentials
 *
 * Returns:     0 - Success
 *              N - From errno.h
 */
/*
 *      ip      parent inode in
 *      cr      credentials in
 */
int
ufs_si_load(struct inode *ip, cred_t *cr)
{
        struct vfs      *vfsp;
        struct inode    *sip;
        ufs_fsd_t       *fsdp;
        si_t            *sp;
        vsecattr_t      vsecattr = { 0, 0, NULL, 0, NULL};
        aclent_t        *aclp;
        ufs_acl_t       *ufsaclp;
        caddr_t         acldata = NULL;
        ino_t           maxino;
        int             err;
        size_t          acldatalen;
        int             numacls;
        int             shadow;
        int             usecnt;
        struct ufsvfs   *ufsvfsp        = ip->i_ufsvfs;
        struct fs       *fs             = ufsvfsp->vfs_fs;

        ASSERT(ip != NULL);
        ASSERT(RW_WRITE_HELD(&ip->i_contents));
        ASSERT(ip->i_shadow && ip->i_ufs_acl == NULL);
        ASSERT((ip->i_mode & IFMT) != IFSHAD);

        if (!CHECK_ACL_ALLOWED(ip->i_mode & IFMT))
                return (ENOSYS);

        if (ip->i_shadow == ip->i_number)
                return (EIO);

        maxino = (ino_t)(ITOF(ip)->fs_ncg * ITOF(ip)->fs_ipg);
        if (ip->i_shadow < UFSROOTINO || ip->i_shadow > maxino)
                return (EIO);

        /*
         * XXX Check cache.  If in cache, link to it and increment
         * the reference count, then return.
         */
        if (si_cachei_get(ip, &sp) == 0) {
                ASSERT(RW_WRITE_HELD(&sp->s_lock));
                ip->i_ufs_acl = sp;
                sp->s_ref++;
                ASSERT(sp->s_ref >= 0 && sp->s_ref <= sp->s_use);
                rw_exit(&sp->s_lock);
                si_cachehit++;
                return (0);
        }

        /* Get the shadow inode */
        vfsp = ITOV(ip)->v_vfsp;
        shadow = ip->i_shadow;
        if ((err = ufs_iget_alloced(vfsp, shadow, &sip, cr)) != 0) {
                return (err);
        }
        rw_enter(&sip->i_contents, RW_WRITER);

        if ((sip->i_mode & IFMT) != IFSHAD) {
                rw_exit(&sip->i_contents);
                err = EINVAL;
                goto alldone;
        }

        ASSERT(sip->i_dquot == 0);
        usecnt = sip->i_nlink;
        if ((!ULOCKFS_IS_NOIACC(&ufsvfsp->vfs_ulockfs)) &&
            (!(sip)->i_ufsvfs->vfs_noatime)) {
                sip->i_flag |= IACC;
        }
        rw_downgrade(&sip->i_contents);

        ASSERT(sip->i_size <= MAXOFF_T);
        /* Read the acl's and other stuff from disk */
        acldata  = kmem_zalloc((size_t)sip->i_size, KM_SLEEP);
        acldatalen = sip->i_size;

        err = ufs_rdwri(UIO_READ, FREAD, sip, acldata, acldatalen, (offset_t)0,
            UIO_SYSSPACE, (int *)0, cr);

        rw_exit(&sip->i_contents);

        if (err)
                goto alldone;

        /*
         * Convert from disk format
         * Result is a vsecattr struct which we then convert to the
         * si struct.
         */
        bzero((caddr_t)&vsecattr, sizeof (vsecattr_t));
        for (fsdp = (ufs_fsd_t *)acldata;
            fsdp < (ufs_fsd_t *)(acldata + acldatalen);
            fsdp = (ufs_fsd_t *)((caddr_t)fsdp +
            FSD_RECSZ(fsdp, fsdp->fsd_size))) {
                if (fsdp->fsd_size <= 0)
                        break;
                switch (fsdp->fsd_type) {
                case FSD_ACL:
                        numacls = vsecattr.vsa_aclcnt =
                            (int)((fsdp->fsd_size -
                            2 * sizeof (int)) / sizeof (ufs_acl_t));
                        aclp = vsecattr.vsa_aclentp =
                            kmem_zalloc(numacls * sizeof (aclent_t), KM_SLEEP);
                        for (ufsaclp = (ufs_acl_t *)fsdp->fsd_data;
                            numacls; ufsaclp++) {
                                aclp->a_type = ufsaclp->acl_tag;
                                aclp->a_id = ufsaclp->acl_who;
                                aclp->a_perm = ufsaclp->acl_perm;
                                aclp++;
                                numacls--;
                        }
                        break;
                case FSD_DFACL:
                        numacls = vsecattr.vsa_dfaclcnt =
                            (int)((fsdp->fsd_size -
                            2 * sizeof (int)) / sizeof (ufs_acl_t));
                        aclp = vsecattr.vsa_dfaclentp =
                            kmem_zalloc(numacls * sizeof (aclent_t), KM_SLEEP);
                        for (ufsaclp = (ufs_acl_t *)fsdp->fsd_data;
                            numacls; ufsaclp++) {
                                aclp->a_type = ufsaclp->acl_tag;
                                aclp->a_id = ufsaclp->acl_who;
                                aclp->a_perm = ufsaclp->acl_perm;
                                aclp++;
                                numacls--;
                        }
                        break;
                }
        }
        /* Sort the lists */
        if (vsecattr.vsa_aclentp) {
                ksort((caddr_t)vsecattr.vsa_aclentp, vsecattr.vsa_aclcnt,
                    sizeof (aclent_t), cmp2acls);
                if ((err = acl_validate(vsecattr.vsa_aclentp,
                    vsecattr.vsa_aclcnt, ACL_CHECK)) != 0) {
                        goto alldone;
                }
        }
        if (vsecattr.vsa_dfaclentp) {
                ksort((caddr_t)vsecattr.vsa_dfaclentp, vsecattr.vsa_dfaclcnt,
                    sizeof (aclent_t), cmp2acls);
                if ((err = acl_validate(vsecattr.vsa_dfaclentp,
                    vsecattr.vsa_dfaclcnt, DEF_ACL_CHECK)) != 0) {
                        goto alldone;
                }
        }

        /* ignore shadow inodes without ACLs */
        if (!vsecattr.vsa_aclentp && !vsecattr.vsa_dfaclentp) {
                err = 0;
                goto alldone;
        }

        /* Convert from vsecattr struct to ufs_acl_entry struct */
        if ((err = vsecattr2aclentry(&vsecattr, &sp)) != 0) {
                goto alldone;
        }

        /* There aren't filled in by vsecattr2aclentry */
        sp->s_shadow = ip->i_shadow;
        sp->s_dev = ip->i_dev;
        sp->s_use = usecnt;
        sp->s_ref = 1;
        ASSERT(sp->s_ref >= 0 && sp->s_ref <= sp->s_use);

        /* XXX Might make a duplicate */
        si_cache_put(sp);

        /* Signal anyone waiting on this shadow to be loaded */
        ip->i_ufs_acl = sp;
        err = 0;
        si_cachemiss++;
        if ((acldatalen + fs->fs_bsize) > ufsvfsp->vfs_maxacl)
                ufsvfsp->vfs_maxacl = acldatalen + fs->fs_bsize;
alldone:
        /*
         * Common exit point. Mark shadow inode as ISTALE
         * if we detect an internal inconsistency, to
         * prevent stray inodes appearing in the cache.
         */
        if (err) {
                rw_enter(&sip->i_contents, RW_READER);
                mutex_enter(&sip->i_tlock);
                sip->i_flag |= ISTALE;
                mutex_exit(&sip->i_tlock);
                rw_exit(&sip->i_contents);
        }
        VN_RELE(ITOV(sip));

        /*
         * Cleanup of data structures allocated
         * on the fly.
         */
        if (acldata)
                kmem_free(acldata, acldatalen);

        if (vsecattr.vsa_aclentp)
                kmem_free(vsecattr.vsa_aclentp,
                    vsecattr.vsa_aclcnt * sizeof (aclent_t));
        if (vsecattr.vsa_dfaclentp)
                kmem_free(vsecattr.vsa_dfaclentp,
                    vsecattr.vsa_dfaclcnt * sizeof (aclent_t));
        return (err);
}

/*
 * Check the inode's ACL's to see if this mode of access is
 * allowed; return 0 if allowed, EACCES if not.
 *
 * We follow the procedure defined in Sec. 3.3.5, ACL Access
 * Check Algorithm, of the POSIX 1003.6 Draft Standard.
 */
/*
 *      ip      parent inode
 *      mode    mode of access read, write, execute/examine
 *      cr      credentials
 */
int
ufs_acl_access(struct inode *ip, int mode, cred_t *cr)
{
        ufs_ic_acl_t *acl;
        int ismask, mask = 0;
        int gperm = 0;
        int ngroup = 0;
        si_t    *sp = NULL;
        uid_t uid = crgetuid(cr);
        uid_t owner;

        ASSERT(ip->i_ufs_acl != NULL);
        ASSERT(RW_LOCK_HELD(&ip->i_contents));

        sp = ip->i_ufs_acl;

        ismask = sp->aclass.acl_ismask ?
            sp->aclass.acl_ismask : 0;

        if (ismask)
                mask = sp->aclass.acl_maskbits;
        else
                mask = -1;

        /*
         * (1) If user owns the file, obey user mode bits
         */
        owner = sp->aowner->acl_ic_who;
        if (uid == owner) {
                return (MODE_CHECK(owner, mode, (sp->aowner->acl_ic_perm << 6),
                    cr, ip));
        }

        /*
         * (2) Obey any matching ACL_USER entry
         */
        if (sp->ausers)
                for (acl = sp->ausers; acl != NULL; acl = acl->acl_ic_next) {
                        if (acl->acl_ic_who == uid) {
                                return (MODE_CHECK(owner, mode,
                                    (mask & acl->acl_ic_perm) << 6, cr, ip));
                        }
                }

        /*
         * (3) If user belongs to file's group, obey group mode bits
         * if no ACL mask is defined; if there is an ACL mask, we look
         * at both the group mode bits and any ACL_GROUP entries.
         */
        if (groupmember((uid_t)sp->agroup->acl_ic_who, cr)) {
                ngroup++;
                gperm = (sp->agroup->acl_ic_perm);
                if (!ismask)
                        return (MODE_CHECK(owner, mode, (gperm << 6), cr, ip));
        }

        /*
         * (4) Accumulate the permissions in matching ACL_GROUP entries
         */
        if (sp->agroups)
                for (acl = sp->agroups; acl != NULL; acl = acl->acl_ic_next) {
                        if (groupmember(acl->acl_ic_who, cr)) {
                                ngroup++;
                                gperm |= acl->acl_ic_perm;
                        }
                }

        if (ngroup != 0)
                return (MODE_CHECK(owner, mode, ((gperm & mask) << 6), cr, ip));

        /*
         * (5) Finally, use the "other" mode bits
         */
        return (MODE_CHECK(owner, mode, sp->aother->acl_ic_perm << 6, cr, ip));
}

/*ARGSUSED2*/
int
ufs_acl_get(struct inode *ip, vsecattr_t *vsap, int flag, cred_t *cr)
{
        aclent_t        *aclentp;

        ASSERT(RW_LOCK_HELD(&ip->i_contents));

        /* XXX Range check, sanity check, shadow check */
        /* If an ACL is present, get the data from the shadow inode info */
        if (ip->i_ufs_acl)
                return (aclentry2vsecattr(ip->i_ufs_acl, vsap));

        /*
         * If no ACLs are present, fabricate one from the mode bits.
         * This code is almost identical to fs_fab_acl(), but we
         * already have the mode bits handy, so we'll avoid going
         * through VOP_GETATTR() again.
         */

        vsap->vsa_aclcnt    = 0;
        vsap->vsa_aclentp   = NULL;
        vsap->vsa_dfaclcnt  = 0;        /* Default ACLs are not fabricated */
        vsap->vsa_dfaclentp = NULL;

        if (vsap->vsa_mask & (VSA_ACLCNT | VSA_ACL))
                vsap->vsa_aclcnt    = 4;  /* USER, GROUP, OTHER, and CLASS */

        if (vsap->vsa_mask & VSA_ACL) {
                vsap->vsa_aclentp = kmem_zalloc(4 * sizeof (aclent_t),
                    KM_SLEEP);
                if (vsap->vsa_aclentp == NULL)
                        return (ENOMEM);
                aclentp = vsap->vsa_aclentp;

                /* Owner */
                aclentp->a_type = USER_OBJ;
                aclentp->a_perm = ((ushort_t)(ip->i_mode & 0700)) >> 6;
                aclentp->a_id = ip->i_uid;      /* Really undefined */
                aclentp++;

                /* Group */
                aclentp->a_type = GROUP_OBJ;
                aclentp->a_perm = ((ushort_t)(ip->i_mode & 0070)) >> 3;
                aclentp->a_id = ip->i_gid;      /* Really undefined */
                aclentp++;

                /* Other */
                aclentp->a_type = OTHER_OBJ;
                aclentp->a_perm = ip->i_mode & 0007;
                aclentp->a_id = 0;              /* Really undefined */
                aclentp++;

                /* Class */
                aclentp->a_type = CLASS_OBJ;
                aclentp->a_perm = ((ushort_t)(ip->i_mode & 0070)) >> 3;
                aclentp->a_id = 0;              /* Really undefined */
                ksort((caddr_t)vsap->vsa_aclentp, vsap->vsa_aclcnt,
                    sizeof (aclent_t), cmp2acls);
        }

        return (0);
}

/*ARGSUSED2*/
int
ufs_acl_set(struct inode *ip, vsecattr_t *vsap, int flag, cred_t *cr)
{
        si_t    *sp;
        int     err;

        ASSERT(RW_WRITE_HELD(&ip->i_contents));

        if (!CHECK_ACL_ALLOWED(ip->i_mode & IFMT))
                return (ENOSYS);

        /*
         * only the owner of the file or privileged users can change the ACLs
         */
        if (secpolicy_vnode_setdac(cr, ip->i_uid) != 0)
                return (EPERM);

        /* Convert from vsecattr struct to ufs_acl_entry struct */
        if ((err = vsecattr2aclentry(vsap, &sp)) != 0)
                return (err);
        sp->s_dev = ip->i_dev;

        /*
         * Make the user & group objs in the acl list follow what's
         * in the inode.
         */
#ifdef DEBUG
        if (vsap->vsa_mask == VSA_ACL) {
                ASSERT(sp->aowner);
                ASSERT(sp->agroup);
                ASSERT(sp->aother);
        }
#endif  /* DEBUG */

        if (sp->aowner)
                sp->aowner->acl_ic_who = ip->i_uid;
        if (sp->agroup)
                sp->agroup->acl_ic_who = ip->i_gid;

        /*
         * Write and cache the new acl list
         */
        err = ufs_si_store(ip, sp, 1, cr);

        return (err);
}

/*
 * XXX Scan sorted array of acl's, checking for:
 * 1) Any duplicate/conflicting entries (same type and id)
 * 2) More than 1 of USER_OBJ, GROUP_OBJ, OTHER_OBJ, CLASS_OBJ
 * 3) More than 1 of DEF_USER_OBJ, DEF_GROUP_OBJ, DEF_OTHER_OBJ, DEF_CLASS_OBJ
 *
 * Parameters:
 * aclentp - ptr to sorted list of acl entries.
 * nentries - # acl entries on the list
 * flag - Bitmap (ACL_CHECK and/or DEF_ACL_CHECK) indicating whether the
 * list contains regular acls, default acls, or both.
 *
 * Returns:     0 - Success
 * EINVAL - Invalid list (dups or multiple entries of type USER_OBJ, etc)
 */
static int
acl_validate(aclent_t *aclentp, int nentries, int flag)
{
        int     i;
        int     nuser_objs = 0;
        int     ngroup_objs = 0;
        int     nother_objs = 0;
        int     nclass_objs = 0;
        int     ndef_user_objs = 0;
        int     ndef_group_objs = 0;
        int     ndef_other_objs = 0;
        int     ndef_class_objs = 0;
        int     nusers = 0;
        int     ngroups = 0;
        int     ndef_users = 0;
        int     ndef_groups = 0;
        int     numdefs = 0;

        /* Null list or list of one */
        if (aclentp == NULL)
                return (0);

        if (nentries <= 0)
                return (EINVAL);

        for (i = 1; i < nentries; i++) {
                if (((aclentp[i - 1].a_type == aclentp[i].a_type) &&
                    (aclentp[i - 1].a_id   == aclentp[i].a_id)) ||
                    (aclentp[i - 1].a_perm > 07)) {
                        return (EINVAL);
                }
        }

        if (flag == 0 || (flag != ACL_CHECK && flag != DEF_ACL_CHECK))
                return (EINVAL);

        /* Count types */
        for (i = 0; i < nentries; i++) {
                switch (aclentp[i].a_type) {
                case USER_OBJ:          /* Owner */
                        nuser_objs++;
                        break;
                case GROUP_OBJ:         /* Group */
                        ngroup_objs++;
                        break;
                case OTHER_OBJ:         /* Other */
                        nother_objs++;
                        break;
                case CLASS_OBJ:         /* Mask */
                        nclass_objs++;
                        break;
                case DEF_USER_OBJ:      /* Default Owner */
                        ndef_user_objs++;
                        break;
                case DEF_GROUP_OBJ:     /* Default Group */
                        ndef_group_objs++;
                        break;
                case DEF_OTHER_OBJ:     /* Default Other */
                        ndef_other_objs++;
                        break;
                case DEF_CLASS_OBJ:     /* Default Mask */
                        ndef_class_objs++;
                        break;
                case USER:              /* Users */
                        nusers++;
                        break;
                case GROUP:             /* Groups */
                        ngroups++;
                        break;
                case DEF_USER:          /* Default Users */
                        ndef_users++;
                        break;
                case DEF_GROUP:         /* Default Groups */
                        ndef_groups++;
                        break;
                default:                /* Unknown type */
                        return (EINVAL);
                }
        }

        /*
         * For normal acl's, we require there be one (and only one)
         * USER_OBJ, GROUP_OBJ and OTHER_OBJ.  There is either zero
         * or one CLASS_OBJ.
         */
        if (flag & ACL_CHECK) {
                if (nuser_objs != 1 || ngroup_objs != 1 ||
                    nother_objs != 1 || nclass_objs > 1) {
                        return (EINVAL);
                }
                /*
                 * If there are ANY group acls, there MUST be a
                 * class_obj(mask) acl (1003.6/D12 p. 29 lines 75-80).
                 */
                if (ngroups && !nclass_objs) {
                        return (EINVAL);
                }
                if (nuser_objs + ngroup_objs + nother_objs + nclass_objs +
                    ngroups + nusers > MAX_ACL_ENTRIES)
                        return (EINVAL);
        }

        /*
         * For default acl's, we require that there be either one (and only one)
         * DEF_USER_OBJ, DEF_GROUP_OBJ and DEF_OTHER_OBJ
         * or  there be none of them.
         */
        if (flag & DEF_ACL_CHECK) {
                if (ndef_other_objs > 1 || ndef_user_objs > 1 ||
                    ndef_group_objs > 1 || ndef_class_objs > 1) {
                        return (EINVAL);
                }

                numdefs = ndef_other_objs + ndef_user_objs + ndef_group_objs;

                if (numdefs != 0 && numdefs != 3) {
                        return (EINVAL);
                }
                /*
                 * If there are ANY def_group acls, there MUST be a
                 * def_class_obj(mask) acl (1003.6/D12 P. 29 lines 75-80).
                 * XXX(jimh) This is inferred.
                 */
                if (ndef_groups && !ndef_class_objs) {
                        return (EINVAL);
                }
                if ((ndef_users || ndef_groups) &&
                    ((numdefs != 3) && !ndef_class_objs)) {
                        return (EINVAL);
                }
                if (ndef_user_objs + ndef_group_objs + ndef_other_objs +
                    ndef_class_objs + ndef_users + ndef_groups >
                    MAX_ACL_ENTRIES)
                        return (EINVAL);
        }
        return (0);
}

static int
formacl(ufs_ic_acl_t **aclpp, aclent_t *aclentp)
{
        ufs_ic_acl_t *uaclp;

        uaclp = kmem_alloc(sizeof (ufs_ic_acl_t), KM_SLEEP);
        uaclp->acl_ic_perm = aclentp->a_perm;
        uaclp->acl_ic_who = aclentp->a_id;
        uaclp->acl_ic_next = *aclpp;
        *aclpp = uaclp;
        return (0);
}

/*
 * XXX - Make more efficient
 * Convert from the vsecattr struct, used by the VOP interface, to
 * the ufs_acl_entry struct used for in-core storage of acl's.
 *
 * Parameters:
 * vsap - Ptr to array of security attributes.
 * spp - Ptr to ptr to si struct for the results
 *
 * Returns:     0 - Success
 *              N - From errno.h
 */
static int
vsecattr2aclentry(vsecattr_t *vsap, si_t **spp)
{
        aclent_t        *aclentp, *aclp;
        si_t            *sp;
        int             err;
        int             i;

        /* Sort & validate the lists on the vsap */
        ksort((caddr_t)vsap->vsa_aclentp, vsap->vsa_aclcnt,
            sizeof (aclent_t), cmp2acls);
        ksort((caddr_t)vsap->vsa_dfaclentp, vsap->vsa_dfaclcnt,
            sizeof (aclent_t), cmp2acls);
        if ((err = acl_validate(vsap->vsa_aclentp,
            vsap->vsa_aclcnt, ACL_CHECK)) != 0)
                return (err);
        if ((err = acl_validate(vsap->vsa_dfaclentp,
            vsap->vsa_dfaclcnt, DEF_ACL_CHECK)) != 0)
                return (err);

        /* Create new si struct and hang acl's off it */
        sp = kmem_zalloc(sizeof (si_t), KM_SLEEP);
        rw_init(&sp->s_lock, NULL, RW_DEFAULT, NULL);

        /* Process acl list */
        aclp = (aclent_t *)vsap->vsa_aclentp;
        aclentp = aclp + vsap->vsa_aclcnt - 1;
        for (i = 0; i < vsap->vsa_aclcnt; i++) {
                switch (aclentp->a_type) {
                case USER_OBJ:          /* Owner */
                        if (err = formacl(&sp->aowner, aclentp))
                                goto error;
                        break;
                case GROUP_OBJ:         /* Group */
                        if (err = formacl(&sp->agroup, aclentp))
                                goto error;
                        break;
                case OTHER_OBJ:         /* Other */
                        if (err = formacl(&sp->aother, aclentp))
                                goto error;
                        break;
                case USER:
                        if (err = formacl(&sp->ausers, aclentp))
                                goto error;
                        break;
                case CLASS_OBJ:         /* Mask */
                        sp->aclass.acl_ismask = 1;
                        sp->aclass.acl_maskbits = aclentp->a_perm;
                        break;
                case GROUP:
                        if (err = formacl(&sp->agroups, aclentp))
                                goto error;
                        break;
                default:
                        break;
                }
                aclentp--;
        }

        /* Process default acl list */
        aclp = (aclent_t *)vsap->vsa_dfaclentp;
        aclentp = aclp + vsap->vsa_dfaclcnt - 1;
        for (i = 0; i < vsap->vsa_dfaclcnt; i++) {
                switch (aclentp->a_type) {
                case DEF_USER_OBJ:      /* Default Owner */
                        if (err = formacl(&sp->downer, aclentp))
                                goto error;
                        break;
                case DEF_GROUP_OBJ:     /* Default Group */
                        if (err = formacl(&sp->dgroup, aclentp))
                                goto error;
                        break;
                case DEF_OTHER_OBJ:     /* Default Other */
                        if (err = formacl(&sp->dother, aclentp))
                                goto error;
                        break;
                case DEF_USER:
                        if (err = formacl(&sp->dusers, aclentp))
                                goto error;
                        break;
                case DEF_CLASS_OBJ:     /* Default Mask */
                        sp->dclass.acl_ismask = 1;
                        sp->dclass.acl_maskbits = aclentp->a_perm;
                        break;
                case DEF_GROUP:
                        if (err = formacl(&sp->dgroups, aclentp))
                                goto error;
                        break;
                default:
                        break;
                }
                aclentp--;
        }
        *spp = sp;
        return (0);

error:
        ufs_si_free_mem(sp);
        return (err);
}

void
formvsec(int obj_type, ufs_ic_acl_t *aclp, aclent_t **aclentpp)
{
        for (; aclp; aclp = aclp->acl_ic_next) {
                (*aclentpp)->a_type = obj_type;
                (*aclentpp)->a_perm = aclp->acl_ic_perm;
                (*aclentpp)->a_id = aclp->acl_ic_who;
                (*aclentpp)++;
        }
}

/*
 * XXX - Make more efficient
 * Convert from the ufs_acl_entry struct used for in-core storage of acl's
 * to the vsecattr struct,  used by the VOP interface.
 *
 * Parameters:
 * sp - Ptr to si struct with the acls
 * vsap - Ptr to a vsecattr struct which will take the results.
 *
 * Returns:     0 - Success
 *              N - From errno table
 */
static int
aclentry2vsecattr(si_t *sp, vsecattr_t *vsap)
{
        aclent_t        *aclentp;
        int             numacls = 0;
        int             err;

        vsap->vsa_aclentp = vsap->vsa_dfaclentp = NULL;

        numacls = acl_count(sp->aowner) +
            acl_count(sp->agroup) +
            acl_count(sp->aother) +
            acl_count(sp->ausers) +
            acl_count(sp->agroups);
        if (sp->aclass.acl_ismask)
                numacls++;

        if (vsap->vsa_mask & (VSA_ACLCNT | VSA_ACL))
                vsap->vsa_aclcnt = numacls;

        if (numacls == 0)
                goto do_defaults;

        if (vsap->vsa_mask & VSA_ACL) {
                vsap->vsa_aclentp = kmem_zalloc(numacls * sizeof (aclent_t),
                    KM_SLEEP);
                aclentp = vsap->vsa_aclentp;

                formvsec(USER_OBJ, sp->aowner, &aclentp);
                formvsec(USER, sp->ausers, &aclentp);
                formvsec(GROUP_OBJ, sp->agroup, &aclentp);
                formvsec(GROUP, sp->agroups, &aclentp);
                formvsec(OTHER_OBJ, sp->aother, &aclentp);

                if (sp->aclass.acl_ismask) {
                        aclentp->a_type = CLASS_OBJ;            /* Mask */
                        aclentp->a_perm = sp->aclass.acl_maskbits;
                        aclentp->a_id = 0;
                        aclentp++;
                }

                /* Sort the acl list */
                ksort((caddr_t)vsap->vsa_aclentp, vsap->vsa_aclcnt,
                    sizeof (aclent_t), cmp2acls);
                /* Check the acl list */
                if ((err = acl_validate(vsap->vsa_aclentp,
                    vsap->vsa_aclcnt, ACL_CHECK)) != 0) {
                        kmem_free(vsap->vsa_aclentp,
                            numacls * sizeof (aclent_t));
                        vsap->vsa_aclentp = NULL;
                        return (err);
                }

        }
do_defaults:
        /* Process Defaults */

        numacls = acl_count(sp->downer) +
            acl_count(sp->dgroup) +
            acl_count(sp->dother) +
            acl_count(sp->dusers) +
            acl_count(sp->dgroups);
        if (sp->dclass.acl_ismask)
                numacls++;

        if (vsap->vsa_mask & (VSA_DFACLCNT | VSA_DFACL))
                vsap->vsa_dfaclcnt = numacls;

        if (numacls == 0)
                goto do_others;

        if (vsap->vsa_mask & VSA_DFACL) {
                vsap->vsa_dfaclentp =
                    kmem_zalloc(numacls * sizeof (aclent_t), KM_SLEEP);
                aclentp = vsap->vsa_dfaclentp;
                formvsec(DEF_USER_OBJ, sp->downer, &aclentp);
                formvsec(DEF_USER, sp->dusers, &aclentp);
                formvsec(DEF_GROUP_OBJ, sp->dgroup, &aclentp);
                formvsec(DEF_GROUP, sp->dgroups, &aclentp);
                formvsec(DEF_OTHER_OBJ, sp->dother, &aclentp);

                if (sp->dclass.acl_ismask) {
                        aclentp->a_type = DEF_CLASS_OBJ;        /* Mask */
                        aclentp->a_perm = sp->dclass.acl_maskbits;
                        aclentp->a_id = 0;
                        aclentp++;
                }

                /* Sort the default acl list */
                ksort((caddr_t)vsap->vsa_dfaclentp, vsap->vsa_dfaclcnt,
                    sizeof (aclent_t), cmp2acls);
                if ((err = acl_validate(vsap->vsa_dfaclentp,
                    vsap->vsa_dfaclcnt, DEF_ACL_CHECK)) != 0) {
                        if (vsap->vsa_aclentp != NULL)
                                kmem_free(vsap->vsa_aclentp,
                                    vsap->vsa_aclcnt * sizeof (aclent_t));
                        kmem_free(vsap->vsa_dfaclentp,
                            vsap->vsa_dfaclcnt * sizeof (aclent_t));
                        vsap->vsa_aclentp = vsap->vsa_dfaclentp = NULL;
                        return (err);
                }
        }

do_others:
        return (0);
}

static void
acl_free(ufs_ic_acl_t *aclp)
{
        while (aclp != NULL) {
                ufs_ic_acl_t *nextaclp = aclp->acl_ic_next;
                kmem_free(aclp, sizeof (ufs_ic_acl_t));
                aclp = nextaclp;
        }
}

/*
 * ufs_si_free_mem will discard the sp, and the acl hanging off of the
 * sp.  It is required that the sp not be locked, and not be in the
 * cache.
 *
 * input: pointer to sp to discard.
 *
 * return - nothing.
 *
 */
static void
ufs_si_free_mem(si_t *sp)
{
        ASSERT(!(sp->s_flags & SI_CACHED));
        ASSERT(!RW_LOCK_HELD(&sp->s_lock));
        /*
         *      remove from the cache
         *      free the acl entries
         */
        acl_free(sp->aowner);
        acl_free(sp->agroup);
        acl_free(sp->aother);
        acl_free(sp->ausers);
        acl_free(sp->agroups);

        acl_free(sp->downer);
        acl_free(sp->dgroup);
        acl_free(sp->dother);
        acl_free(sp->dusers);
        acl_free(sp->dgroups);

        rw_destroy(&sp->s_lock);
        kmem_free(sp, sizeof (si_t));
}

void
acl_cpy(ufs_ic_acl_t *saclp, ufs_ic_acl_t *daclp)
{
        ufs_ic_acl_t  *aclp, *prev_aclp = NULL, *aclp1;

        if (saclp == NULL) {
                daclp = NULL;
                return;
        }
        prev_aclp = daclp;

        for (aclp = saclp; aclp != NULL; aclp = aclp->acl_ic_next) {
                aclp1 = kmem_alloc(sizeof (ufs_ic_acl_t), KM_SLEEP);
                aclp1->acl_ic_next = NULL;
                aclp1->acl_ic_who = aclp->acl_ic_who;
                aclp1->acl_ic_perm = aclp->acl_ic_perm;
                prev_aclp->acl_ic_next = aclp1;
                prev_aclp = (ufs_ic_acl_t *)&aclp1->acl_ic_next;
        }
}

/*
 *      ufs_si_inherit takes a parent acl structure (saclp) and the inode
 *      of the object that is inheriting an acl and returns the inode
 *      with the acl linked to it.  It also writes the acl to disk if
 *      it is a unique inode.
 *
 *      ip - pointer to inode of object inheriting the acl (contents lock)
 *      tdp - parent inode (rw_lock and contents lock)
 *      mode - creation modes
 *      cr - credentials pointer
 */
int
ufs_si_inherit(struct inode *ip, struct inode *tdp, o_mode_t mode, cred_t *cr)
{
        si_t *tsp, *sp = tdp->i_ufs_acl;
        int error;
        o_mode_t old_modes, old_uid, old_gid;
        int mask;

        ASSERT(RW_WRITE_HELD(&ip->i_contents));
        ASSERT(RW_WRITE_HELD(&tdp->i_rwlock));
        ASSERT(RW_WRITE_HELD(&tdp->i_contents));

        /*
         * if links/symbolic links, or other invalid acl objects are copied
         * or moved to a directory with a default acl do not allow inheritance
         * just return.
         */
        if (!CHECK_ACL_ALLOWED(ip->i_mode & IFMT))
                return (0);

        /* lock the parent security information */
        rw_enter(&sp->s_lock, RW_READER);

        ASSERT(((tdp->i_mode & IFMT) == IFDIR) ||
            ((tdp->i_mode & IFMT) == IFATTRDIR));

        mask = ((sp->downer != NULL) ? 1 : 0) |
            ((sp->dgroup != NULL) ? 2 : 0) |
            ((sp->dother != NULL) ? 4 : 0);

        if (mask == 0) {
                rw_exit(&sp->s_lock);
                return (0);
        }

        if (mask != 7) {
                rw_exit(&sp->s_lock);
                return (EINVAL);
        }

        tsp = kmem_zalloc(sizeof (si_t), KM_SLEEP);
        rw_init(&tsp->s_lock, NULL, RW_DEFAULT, NULL);

        /* copy the default acls */

        ASSERT(RW_READ_HELD(&sp->s_lock));
        acl_cpy(sp->downer, (ufs_ic_acl_t *)&tsp->aowner);
        acl_cpy(sp->dgroup, (ufs_ic_acl_t *)&tsp->agroup);
        acl_cpy(sp->dother, (ufs_ic_acl_t *)&tsp->aother);
        acl_cpy(sp->dusers, (ufs_ic_acl_t *)&tsp->ausers);
        acl_cpy(sp->dgroups, (ufs_ic_acl_t *)&tsp->agroups);
        tsp->aclass.acl_ismask = sp->dclass.acl_ismask;
        tsp->aclass.acl_maskbits = sp->dclass.acl_maskbits;

        /*
         * set the owner, group, and other values from the master
         * inode.
         */

        MODE2ACL(tsp->aowner, (mode >> 6), ip->i_uid);
        MODE2ACL(tsp->agroup, (mode >> 3), ip->i_gid);
        MODE2ACL(tsp->aother, (mode), 0);

        if (tsp->aclass.acl_ismask) {
                tsp->aclass.acl_maskbits &= mode >> 3;
        }


        /* copy default acl if necessary */

        if (((ip->i_mode & IFMT) == IFDIR) ||
            ((ip->i_mode & IFMT) == IFATTRDIR)) {
                acl_cpy(sp->downer, (ufs_ic_acl_t *)&tsp->downer);
                acl_cpy(sp->dgroup, (ufs_ic_acl_t *)&tsp->dgroup);
                acl_cpy(sp->dother, (ufs_ic_acl_t *)&tsp->dother);
                acl_cpy(sp->dusers, (ufs_ic_acl_t *)&tsp->dusers);
                acl_cpy(sp->dgroups, (ufs_ic_acl_t *)&tsp->dgroups);
                tsp->dclass.acl_ismask = sp->dclass.acl_ismask;
                tsp->dclass.acl_maskbits = sp->dclass.acl_maskbits;
        }
        /*
         * save the new 9 mode bits in the inode (ip->ic_smode) for
         * ufs_getattr.  Be sure the mode can be recovered if the store
         * fails.
         */
        old_modes = ip->i_mode;
        old_uid = ip->i_uid;
        old_gid = ip->i_gid;
        /*
         * store the acl, and get back a new security anchor if
         * it is a duplicate.
         */
        rw_exit(&sp->s_lock);
        rw_enter(&ip->i_rwlock, RW_WRITER);

        /*
         * Suppress out of inodes messages if instructed in the
         * tdp inode.
         */
        ip->i_flag |= tdp->i_flag & IQUIET;

        if ((error = ufs_si_store(ip, tsp, 0, cr)) != 0) {
                ip->i_mode = old_modes;
                ip->i_uid = old_uid;
                ip->i_gid = old_gid;
        }
        ip->i_flag &= ~IQUIET;
        rw_exit(&ip->i_rwlock);
        return (error);
}

si_t *
ufs_acl_cp(si_t *sp)
{

        si_t *dsp;

        ASSERT(RW_READ_HELD(&sp->s_lock));
        ASSERT(sp->s_ref && sp->s_use);

        dsp = kmem_zalloc(sizeof (si_t), KM_SLEEP);
        rw_init(&dsp->s_lock, NULL, RW_DEFAULT, NULL);

        acl_cpy(sp->aowner, (ufs_ic_acl_t *)&dsp->aowner);
        acl_cpy(sp->agroup, (ufs_ic_acl_t *)&dsp->agroup);
        acl_cpy(sp->aother, (ufs_ic_acl_t *)&dsp->aother);
        acl_cpy(sp->ausers, (ufs_ic_acl_t *)&dsp->ausers);
        acl_cpy(sp->agroups, (ufs_ic_acl_t *)&dsp->agroups);

        dsp->aclass.acl_ismask = sp->aclass.acl_ismask;
        dsp->aclass.acl_maskbits = sp->aclass.acl_maskbits;

        acl_cpy(sp->downer, (ufs_ic_acl_t *)&dsp->downer);
        acl_cpy(sp->dgroup, (ufs_ic_acl_t *)&dsp->dgroup);
        acl_cpy(sp->dother, (ufs_ic_acl_t *)&dsp->dother);
        acl_cpy(sp->dusers, (ufs_ic_acl_t *)&dsp->dusers);
        acl_cpy(sp->dgroups, (ufs_ic_acl_t *)&dsp->dgroups);

        dsp->dclass.acl_ismask = sp->dclass.acl_ismask;
        dsp->dclass.acl_maskbits = sp->dclass.acl_maskbits;

        return (dsp);

}

int
ufs_acl_setattr(struct inode *ip, struct vattr *vap, cred_t *cr)
{

        si_t *sp;
        int mask = vap->va_mask;
        int error = 0;

        ASSERT(RW_WRITE_HELD(&ip->i_contents));

        if (!(mask & (AT_MODE|AT_UID|AT_GID)))
                return (0);

        /*
         * if no regular acl's, nothing to do, so let's get out
         */
        if (!(ip->i_ufs_acl) || !(ip->i_ufs_acl->aowner))
                return (0);

        rw_enter(&ip->i_ufs_acl->s_lock, RW_READER);
        sp = ufs_acl_cp(ip->i_ufs_acl);
        ASSERT(sp != ip->i_ufs_acl);

        /*
         * set the mask to the group permissions if a mask entry
         * exists.  Otherwise, set the group obj bits to the group
         * permissions.  Since non-trivial ACLs always have a mask,
         * and the mask is the final arbiter of group permissions,
         * setting the mask has the effect of changing the effective
         * group permissions, even if the group_obj permissions in
         * the ACL aren't changed.  Posix P1003.1e states that when
         * an ACL mask exists, chmod(2) must set the acl mask (NOT the
         * group_obj permissions) to the requested group permissions.
         */
        if (mask & AT_MODE) {
                sp->aowner->acl_ic_perm = (o_mode_t)(ip->i_mode & 0700) >> 6;
                if (sp->aclass.acl_ismask)
                        sp->aclass.acl_maskbits =
                            (o_mode_t)(ip->i_mode & 070) >> 3;
                else
                        sp->agroup->acl_ic_perm =
                            (o_mode_t)(ip->i_mode & 070) >> 3;
                sp->aother->acl_ic_perm = (o_mode_t)(ip->i_mode & 07);
        }

        if (mask & AT_UID) {
                /* Caller has verified our privileges */
                sp->aowner->acl_ic_who = ip->i_uid;
        }

        if (mask & AT_GID) {
                sp->agroup->acl_ic_who = ip->i_gid;
        }

        rw_exit(&ip->i_ufs_acl->s_lock);
        error = ufs_si_store(ip, sp, 0, cr);
        return (error);
}

static int
acl_count(ufs_ic_acl_t *p)
{
        ufs_ic_acl_t    *acl;
        int             count;

        for (count = 0, acl = p; acl; acl = acl->acl_ic_next, count++)
                ;
        return (count);
}

/*
 *      Takes as input a security structure and generates a buffer
 *      with fsd's in a form which be written to the shadow inode.
 */
static int
ufs_sectobuf(si_t *sp, caddr_t *buf, size_t *len)
{
        size_t          acl_size;
        size_t          def_acl_size;
        caddr_t         buffer;
        struct ufs_fsd  *fsdp;
        ufs_acl_t       *bufaclp;

        /*
         * Calc size of buffer to hold all the acls
         */
        acl_size = acl_count(sp->aowner) +              /* owner */
            acl_count(sp->agroup) +                     /* owner group */
            acl_count(sp->aother) +                     /* owner other */
            acl_count(sp->ausers) +                     /* acl list */
            acl_count(sp->agroups);                     /* group alcs */
        if (sp->aclass.acl_ismask)
                acl_size++;

        /* Convert to bytes */
        acl_size *= sizeof (ufs_acl_t);

        /* Add fsd header */
        if (acl_size)
                acl_size += 2 * sizeof (int);

        /*
         * Calc size of buffer to hold all the default acls
         */
        def_acl_size =
            acl_count(sp->downer) +     /* def owner */
            acl_count(sp->dgroup) +     /* def owner group */
            acl_count(sp->dother) +     /* def owner other */
            acl_count(sp->dusers) +     /* def users  */
            acl_count(sp->dgroups);     /* def group acls */
        if (sp->dclass.acl_ismask)
                def_acl_size++;

        /*
         * Convert to bytes
         */
        def_acl_size *= sizeof (ufs_acl_t);

        /*
         * Add fsd header
         */
        if (def_acl_size)
                def_acl_size += 2 * sizeof (int);

        if (acl_size + def_acl_size == 0)
                return (0);

        buffer = kmem_zalloc((acl_size + def_acl_size), KM_SLEEP);
        bufaclp = (ufs_acl_t *)buffer;

        if (acl_size == 0)
                goto wrtdefs;

        /* create fsd and copy acls */
        fsdp = (struct ufs_fsd *)bufaclp;
        fsdp->fsd_type = FSD_ACL;
        bufaclp = (ufs_acl_t *)&fsdp->fsd_data[0];

        ACL_MOVE(sp->aowner, USER_OBJ, bufaclp);
        ACL_MOVE(sp->agroup, GROUP_OBJ, bufaclp);
        ACL_MOVE(sp->aother, OTHER_OBJ, bufaclp);
        ACL_MOVE(sp->ausers, USER, bufaclp);
        ACL_MOVE(sp->agroups, GROUP, bufaclp);

        if (sp->aclass.acl_ismask) {
                bufaclp->acl_tag = CLASS_OBJ;
                bufaclp->acl_who = (uid_t)sp->aclass.acl_ismask;
                bufaclp->acl_perm = (o_mode_t)sp->aclass.acl_maskbits;
                bufaclp++;
        }
        ASSERT(acl_size <= INT_MAX);
        fsdp->fsd_size = (int)acl_size;

wrtdefs:
        if (def_acl_size == 0)
                goto alldone;

        /* if defaults exist then create fsd and copy default acls */
        fsdp = (struct ufs_fsd *)bufaclp;
        fsdp->fsd_type = FSD_DFACL;
        bufaclp = (ufs_acl_t *)&fsdp->fsd_data[0];

        ACL_MOVE(sp->downer, DEF_USER_OBJ, bufaclp);
        ACL_MOVE(sp->dgroup, DEF_GROUP_OBJ, bufaclp);
        ACL_MOVE(sp->dother, DEF_OTHER_OBJ, bufaclp);
        ACL_MOVE(sp->dusers, DEF_USER, bufaclp);
        ACL_MOVE(sp->dgroups, DEF_GROUP, bufaclp);
        if (sp->dclass.acl_ismask) {
                bufaclp->acl_tag = DEF_CLASS_OBJ;
                bufaclp->acl_who = (uid_t)sp->dclass.acl_ismask;
                bufaclp->acl_perm = (o_mode_t)sp->dclass.acl_maskbits;
                bufaclp++;
        }
        ASSERT(def_acl_size <= INT_MAX);
        fsdp->fsd_size = (int)def_acl_size;

alldone:
        *buf = buffer;
        *len = acl_size + def_acl_size;

        return (0);
}

/*
 *  free a shadow inode  on disk and in memory
 */
int
ufs_si_free(si_t *sp, struct vfs *vfsp, cred_t *cr)
{
        struct inode    *sip;
        int             shadow;
        int             err = 0;
        int             refcnt;
        int             signature;

        ASSERT(vfsp);
        ASSERT(sp);

        rw_enter(&sp->s_lock, RW_READER);
        ASSERT(sp->s_shadow <= INT_MAX);
        shadow = (int)sp->s_shadow;
        ASSERT(sp->s_ref);
        rw_exit(&sp->s_lock);

        /*
         * Decrement link count on the shadow inode,
         * and decrement reference count on the sip.
         */
        if ((err = ufs_iget_alloced(vfsp, shadow, &sip, cr)) == 0) {
                rw_enter(&sip->i_contents, RW_WRITER);
                rw_enter(&sp->s_lock, RW_WRITER);
                ASSERT(sp->s_shadow == shadow);
                ASSERT(sip->i_dquot == 0);
                /* Decrement link count */
                ASSERT(sip->i_nlink > 0);
                /*
                 * bug #1264710 assertion failure below
                 */
                sp->s_use = --sip->i_nlink;
                ufs_setreclaim(sip);
                TRANS_INODE(sip->i_ufsvfs, sip);
                sip->i_flag |= ICHG | IMOD;
                sip->i_seq++;
                ITIMES_NOLOCK(sip);
                /* Dec ref counts on si referenced by this ip */
                refcnt = --sp->s_ref;
                signature = sp->s_signature;
                ASSERT(sp->s_ref >= 0 && sp->s_ref <= sp->s_use);
                /*
                 * Release s_lock before calling VN_RELE
                 * (which may want to acquire i_contents).
                 */
                rw_exit(&sp->s_lock);
                rw_exit(&sip->i_contents);
                VN_RELE(ITOV(sip));
        } else {
                rw_enter(&sp->s_lock, RW_WRITER);
                /* Dec ref counts on si referenced by this ip */
                refcnt = --sp->s_ref;
                signature = sp->s_signature;
                ASSERT(sp->s_ref >= 0 && sp->s_ref <= sp->s_use);
                rw_exit(&sp->s_lock);
        }

        if (refcnt == 0)
                si_cache_del(sp, signature);
        return (err);
}

/*
 * Seach the si cache for an si structure by inode #.
 * Returns a locked si structure.
 *
 * Parameters:
 * ip - Ptr to an inode on this fs
 * spp - Ptr to ptr to si struct for the results, if found.
 *
 * Returns:     0 - Success (results in spp)
 *              1 - Failure (spp undefined)
 */
static int
si_cachei_get(struct inode *ip, si_t **spp)
{
        si_t    *sp;

        rw_enter(&si_cache_lock, RW_READER);

        for (sp = si_cachei[SI_HASH(ip->i_shadow)]; sp; sp = sp->s_forw)
                if (sp->s_shadow == ip->i_shadow && sp->s_dev == ip->i_dev)
                        break;

        if (sp == NULL) {
                /* Not in cache */
                rw_exit(&si_cache_lock);
                return (1);
        }
        /* Found it */
        rw_enter(&sp->s_lock, RW_WRITER);
        rw_exit(&si_cache_lock);
        *spp = sp;
        return (0);
}

/*
 * Seach the si cache by si structure (ie duplicate of the one passed in).
 * In order for a match the signatures must be the same and
 * the devices must be the same, the acls must match and
 * link count of the cached shadow must be less than the
 * size of ic_nlink - 1.  MAXLINK - 1 is used to allow the count
 * to be incremented one more time by the caller.
 * Returns a locked si structure.
 *
 * Parameters:
 * ip - Ptr to an inode on this fs
 * spi - Ptr to si the struct we're searching the cache for.
 * spp - Ptr to ptr to si struct for the results, if found.
 *
 * Returns:     0 - Success (results in spp)
 *              1 - Failure (spp undefined)
 */
static int
si_cachea_get(struct inode *ip, si_t *spi, si_t **spp)
{
        si_t    *sp;

        spi->s_dev = ip->i_dev;
        spi->s_signature = si_signature(spi);
        rw_enter(&si_cache_lock, RW_READER);

        for (sp = si_cachea[SI_HASH(spi->s_signature)]; sp; sp = sp->s_next) {
                if (sp->s_signature == spi->s_signature &&
                    sp->s_dev == spi->s_dev &&
                    sp->s_use > 0 &&                    /* deleting */
                    sp->s_use <= (MAXLINK - 1) &&       /* Too many links */
                    !si_cmp(sp, spi))
                        break;
        }

        if (sp == NULL) {
                /* Cache miss */
                rw_exit(&si_cache_lock);
                return (1);
        }
        /* Found it */
        rw_enter(&sp->s_lock, RW_WRITER);
        spi->s_shadow = sp->s_shadow; /* XXX For debugging */
        rw_exit(&si_cache_lock);
        *spp = sp;
        return (0);
}

/*
 * Place an si structure in the si cache.  May cause duplicates.
 *
 * Parameters:
 * sp - Ptr to the si struct to add to the cache.
 *
 * Returns: Nothing (void)
 */
static void
si_cache_put(si_t *sp)
{
        si_t    **tspp;

        ASSERT(sp->s_fore == NULL);
        rw_enter(&si_cache_lock, RW_WRITER);
        if (!sp->s_signature)
                sp->s_signature = si_signature(sp);
        sp->s_flags |= SI_CACHED;
        sp->s_fore = NULL;

        /* The 'by acl' chains */
        tspp = &si_cachea[SI_HASH(sp->s_signature)];
        sp->s_next = *tspp;
        *tspp = sp;

        /* The 'by inode' chains */
        tspp = &si_cachei[SI_HASH(sp->s_shadow)];
        sp->s_forw = *tspp;
        *tspp = sp;

        rw_exit(&si_cache_lock);
}

/*
 * The sp passed in is a candidate for deletion from the cache.  We acquire
 * the cache lock first, so no cache searches can be done.  Then we search
 * for the acl in the cache, and if we find it we can lock it and check that
 * nobody else attached to it while we were acquiring the locks.  If the acl
 * is in the cache and still has a zero reference count, then we remove it
 * from the cache and deallocate it.  If the reference count is non-zero or
 * it is not found in the cache, then someone else attached to it or has
 * already freed it, so we just return.
 *
 * Parameters:
 * sp - Ptr to the sp struct which is the candicate for deletion.
 * signature - the signature for the acl for lookup in the hash table
 *
 * Returns: Nothing (void)
 */
void
si_cache_del(si_t *sp, int signature)
{
        si_t    **tspp;
        int     hash;
        int     foundacl = 0;

        /*
         * Unlink & free the sp from the other queues, then destroy it.
         * Search the 'by acl' chain first, then the 'by inode' chain
         * after the acl is locked.
         */
        rw_enter(&si_cache_lock, RW_WRITER);
        hash = SI_HASH(signature);
        for (tspp = &si_cachea[hash]; *tspp; tspp = &(*tspp)->s_next) {
                if (*tspp == sp) {
                        /*
                         * Wait to grab the acl lock until after the acl has
                         * been found in the cache.  Otherwise it might try to
                         * grab a lock that has already been destroyed, or
                         * delete an acl that has already been freed.
                         */
                        rw_enter(&sp->s_lock, RW_WRITER);
                        /* See if someone else attached to it */
                        if (sp->s_ref) {
                                rw_exit(&sp->s_lock);
                                rw_exit(&si_cache_lock);
                                return;
                        }
                        ASSERT(sp->s_fore == NULL);
                        ASSERT(sp->s_flags & SI_CACHED);
                        foundacl = 1;
                        *tspp = sp->s_next;
                        break;
                }
        }

        /*
         * If the acl was not in the cache, we assume another thread has
         * deleted it already. This could happen if another thread attaches to
         * the acl and then releases it after this thread has already found the
         * reference count to be zero but has not yet taken the cache lock.
         * Both threads end up seeing a reference count of zero, and call into
         * si_cache_del.  See bug 4244827 for details on the race condition.
         */
        if (foundacl == 0) {
                rw_exit(&si_cache_lock);
                return;
        }

        /* Now check the 'by inode' chain */
        hash = SI_HASH(sp->s_shadow);
        for (tspp = &si_cachei[hash]; *tspp; tspp = &(*tspp)->s_forw) {
                if (*tspp == sp) {
                        *tspp = sp->s_forw;
                        break;
                }
        }

        /*
         * At this point, we can unlock everything because this si
         * is no longer in the cache, thus cannot be attached to.
         */
        rw_exit(&sp->s_lock);
        rw_exit(&si_cache_lock);
        sp->s_flags &= ~SI_CACHED;
        (void) ufs_si_free_mem(sp);
}

/*
 * Alloc the hash buckets for the si cache & initialize
 * the unreferenced anchor and the cache lock.
 */
void
si_cache_init(void)
{
        rw_init(&si_cache_lock, NULL, RW_DEFAULT, NULL);

        /* The 'by acl' headers */
        si_cachea = kmem_zalloc(si_cachecnt * sizeof (si_t *), KM_SLEEP);
        /* The 'by inode' headers */
        si_cachei = kmem_zalloc(si_cachecnt * sizeof (si_t *), KM_SLEEP);
}

/*
 *  aclcksum takes an acl and generates a checksum.  It takes as input
 *  the acl to start at.
 *
 *  s_aclp - pointer to starting acl
 *
 *  returns checksum
 */
static int
aclcksum(ufs_ic_acl_t *s_aclp)
{
        ufs_ic_acl_t *aclp;
        int signature = 0;
        for (aclp = s_aclp; aclp; aclp = aclp->acl_ic_next) {
                signature += aclp->acl_ic_perm;
                signature += aclp->acl_ic_who;
        }
        return (signature);
}

/*
 * Generate a unique signature for an si structure.  Used by the
 * search routine si_cachea_get() to quickly identify candidates
 * prior to calling si_cmp().
 * Parameters:
 * sp - Ptr to the si struct to generate the signature for.
 *
 * Returns:  A signature for the si struct (really a checksum)
 */
static int
si_signature(si_t *sp)
{
        int signature = sp->s_dev;

        signature += aclcksum(sp->aowner) + aclcksum(sp->agroup) +
            aclcksum(sp->aother) + aclcksum(sp->ausers) +
            aclcksum(sp->agroups) + aclcksum(sp->downer) +
            aclcksum(sp->dgroup) + aclcksum(sp->dother) +
            aclcksum(sp->dusers) + aclcksum(sp->dgroups);
        if (sp->aclass.acl_ismask)
                signature += sp->aclass.acl_maskbits;
        if (sp->dclass.acl_ismask)
                signature += sp->dclass.acl_maskbits;

        return (signature);
}

/*
 * aclcmp compares to acls to see if they are identical.
 *
 * sp1 is source
 * sp2 is sourceb
 *
 * returns 0 if equal and 1 if not equal
 */
static int
aclcmp(ufs_ic_acl_t *aclin1p, ufs_ic_acl_t *aclin2p)
{
        ufs_ic_acl_t *aclp1;
        ufs_ic_acl_t *aclp2;

        /*
         * if the starting pointers are equal then they are equal so
         * just return.
         */
        if (aclin1p == aclin2p)
                return (0);
        /*
         * check element by element
         */
        for (aclp1 = aclin1p, aclp2 = aclin2p; aclp1 && aclp2;
            aclp1 = aclp1->acl_ic_next, aclp2 = aclp2->acl_ic_next) {
                if (aclp1->acl_ic_perm != aclp2->acl_ic_perm ||
                    aclp1->acl_ic_who != aclp2->acl_ic_who)
                        return (1);
        }
        /*
         * both must be zero (at the end of the acl)
         */
        if (aclp1 || aclp2)
                return (1);

        return (0);
}

/*
 * Do extensive, field-by-field compare of two si structures.  Returns
 * 0 if they are exactly identical, 1 otherwise.
 *
 * Paramters:
 * sp1 - Ptr to 1st si struct
 * sp2 - Ptr to 2nd si struct
 *
 * Returns:
 *              0 - Not identical
 *              1 - Identical
 */
static int
si_cmp(si_t *sp1, si_t *sp2)
{
        if (sp1->s_dev != sp2->s_dev)
                return (1);
        if (aclcmp(sp1->aowner, sp2->aowner) ||
            aclcmp(sp1->agroup, sp2->agroup) ||
            aclcmp(sp1->aother, sp2->aother) ||
            aclcmp(sp1->ausers, sp2->ausers) ||
            aclcmp(sp1->agroups, sp2->agroups) ||
            aclcmp(sp1->downer, sp2->downer) ||
            aclcmp(sp1->dgroup, sp2->dgroup) ||
            aclcmp(sp1->dother, sp2->dother) ||
            aclcmp(sp1->dusers, sp2->dusers) ||
            aclcmp(sp1->dgroups, sp2->dgroups))
                return (1);
        if (sp1->aclass.acl_ismask != sp2->aclass.acl_ismask)
                return (1);
        if (sp1->dclass.acl_ismask != sp2->dclass.acl_ismask)
                return (1);
        if (sp1->aclass.acl_ismask &&
            sp1->aclass.acl_maskbits != sp2->aclass.acl_maskbits)
                return (1);
        if (sp1->dclass.acl_ismask &&
            sp1->dclass.acl_maskbits != sp2->dclass.acl_maskbits)
                return (1);

        return (0);
}

/*
 * Remove all acls associated with a device.  All acls must have
 * a reference count of zero.
 *
 * inputs:
 *      device - device to remove from the cache
 *
 * outputs:
 *      none
 */
void
ufs_si_cache_flush(dev_t dev)
{
        si_t *tsp, **tspp;
        int i;

        rw_enter(&si_cache_lock, RW_WRITER);
        for (i = 0; i < si_cachecnt; i++) {
                tspp = &si_cachea[i];
                while (*tspp) {
                        if ((*tspp)->s_dev == dev) {
                                *tspp = (*tspp)->s_next;
                        } else {
                                tspp = &(*tspp)->s_next;
                        }
                }
        }
        for (i = 0; i < si_cachecnt; i++) {
                tspp = &si_cachei[i];
                while (*tspp) {
                        if ((*tspp)->s_dev == dev) {
                                tsp = *tspp;
                                *tspp = (*tspp)->s_forw;
                                tsp->s_flags &= ~SI_CACHED;
                                ufs_si_free_mem(tsp);
                        } else {
                                tspp = &(*tspp)->s_forw;
                        }
                }
        }
        rw_exit(&si_cache_lock);
}

/*
 * ufs_si_del is used to unhook a sp from a inode in memory
 *
 * ip is the inode to remove the sp from.
 */
void
ufs_si_del(struct inode *ip)
{
        si_t    *sp = ip->i_ufs_acl;
        int     refcnt;
        int     signature;

        if (sp) {
                rw_enter(&sp->s_lock, RW_WRITER);
                refcnt = --sp->s_ref;
                signature = sp->s_signature;
                ASSERT(sp->s_ref >= 0 && sp->s_ref <= sp->s_use);
                rw_exit(&sp->s_lock);
                if (refcnt == 0)
                        si_cache_del(sp, signature);
                ip->i_ufs_acl = NULL;
        }
}