/*
 * 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 2007 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*      Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T     */
/*        All Rights Reserved   */

/*
 * Portions of this source code were derived from Berkeley 4.3 BSD
 * under license from the Regents of the University of California.
 */

#include <sys/param.h>
#include <sys/isa_defs.h>
#include <sys/types.h>
#include <sys/sysmacros.h>
#include <sys/cred.h>
#include <sys/systm.h>
#include <sys/errno.h>
#include <sys/fcntl.h>
#include <sys/pathname.h>
#include <sys/vfs.h>
#include <sys/vnode.h>
#include <sys/file.h>
#include <sys/mode.h>
#include <sys/uio.h>
#include <sys/kmem.h>
#include <sys/filio.h>
#include <sys/acl.h>
#include <sys/cmn_err.h>
#include <acl/acl_common.h>

#include <sys/unistd.h>
#include <sys/debug.h>
#include <fs/fs_subr.h>

static int cacl(int cmd, int nentries, void *aclbufp,
    vnode_t *vp, int *rv);

/*
 * Get/Set ACL of a file.
 */
int
acl(const char *fname, int cmd, int nentries, void *aclbufp)
{
        struct vnode *vp;
        int error;
        int rv = 0;
        int estale_retry = 0;

        /* Sanity check arguments */
        if (fname == NULL)
                return (set_errno(EINVAL));
lookup:
        error = lookupname((char *)fname, UIO_USERSPACE, FOLLOW, NULLVPP, &vp);
        if (error) {
                if ((error == ESTALE) && fs_need_estale_retry(estale_retry++))
                        goto lookup;
                return (set_errno(error));
        }

        error = cacl(cmd, nentries, aclbufp, vp, &rv);
        VN_RELE(vp);
        if (error) {
                if ((error == ESTALE) && fs_need_estale_retry(estale_retry++))
                        goto lookup;
                return (set_errno(error));
        }
        return (rv);
}

/*
 * Get/Set ACL of a file with facl system call.
 */
int
facl(int fdes, int cmd, int nentries, void *aclbufp)
{
        file_t *fp;
        int error;
        int rv = 0;

        if ((fp = getf(fdes)) == NULL)
                return (set_errno(EBADF));
        if (fp->f_flag & FREVOKED) {
                releasef(fdes);
                return (set_errno(EBADF));
        }

        error = cacl(cmd, nentries, aclbufp, fp->f_vnode, &rv);
        releasef(fdes);

        if (error)
                return (set_errno(error));
        return (rv);
}


/*
 * Common code for acl() and facl().
 */
static int
cacl(int cmd, int nentries, void *aclbufp, vnode_t *vp, int *rv)
{
        int             error;
        int             aclbsize;       /* size of acl list in bytes */
        int             dfaclbsize;     /* size of default acl list in bytes */
        int             numacls;
        caddr_t         uaddrp;
        aclent_t        *aclp, *aaclp;
        vsecattr_t      vsecattr;
        size_t          entry_size;

        ASSERT(vp);

        bzero(&vsecattr, sizeof (vsecattr_t));
        dfaclbsize = 0;

        switch (cmd) {

        case ACE_GETACLCNT:
        case GETACLCNT:
                if (cmd == GETACLCNT) {
                        entry_size = sizeof (aclent_t);
                        vsecattr.vsa_mask = VSA_ACLCNT | VSA_DFACLCNT;
                } else {
                        entry_size = sizeof (ace_t);
                        vsecattr.vsa_mask = VSA_ACECNT;
                }
                if (error = VOP_GETSECATTR(vp, &vsecattr, 0, CRED(), NULL))
                        return (error);
                *rv = vsecattr.vsa_aclcnt + vsecattr.vsa_dfaclcnt;
                if (vsecattr.vsa_aclcnt && vsecattr.vsa_aclentp) {
                        kmem_free(vsecattr.vsa_aclentp,
                            vsecattr.vsa_aclcnt * entry_size);
                }
                if (vsecattr.vsa_dfaclcnt && vsecattr.vsa_dfaclentp) {
                        kmem_free(vsecattr.vsa_dfaclentp,
                            vsecattr.vsa_dfaclcnt * entry_size);
                }
                break;
        case GETACL:
                /*
                 * Minimum ACL size is three entries so might as well
                 * bail out here.
                 */
                if (nentries < 3)
                        return (EINVAL);
                /*
                 * NULL output buffer is also a pretty easy bail out.
                 */
                if (aclbufp == NULL)
                        return (EFAULT);
                vsecattr.vsa_mask = VSA_ACL | VSA_ACLCNT | VSA_DFACL |
                    VSA_DFACLCNT;
                if (error = VOP_GETSECATTR(vp, &vsecattr, 0, CRED(), NULL))
                        return (error);
                /* Check user's buffer is big enough */
                numacls = vsecattr.vsa_aclcnt + vsecattr.vsa_dfaclcnt;
                aclbsize = vsecattr.vsa_aclcnt * sizeof (aclent_t);
                dfaclbsize = vsecattr.vsa_dfaclcnt * sizeof (aclent_t);
                if (numacls > nentries) {
                        error = ENOSPC;
                        goto errout;
                }
                /* Sort the acl & default acl lists */
                if (vsecattr.vsa_aclcnt > 1)
                        ksort((caddr_t)vsecattr.vsa_aclentp,
                            vsecattr.vsa_aclcnt, sizeof (aclent_t), cmp2acls);
                if (vsecattr.vsa_dfaclcnt > 1)
                        ksort((caddr_t)vsecattr.vsa_dfaclentp,
                            vsecattr.vsa_dfaclcnt, sizeof (aclent_t), cmp2acls);
                /* Copy out acl's */
                uaddrp = (caddr_t)aclbufp;
                if (aclbsize > 0) {     /* bug #1262490 */
                        if (copyout(vsecattr.vsa_aclentp, uaddrp, aclbsize)) {
                                error = EFAULT;
                                goto errout;
                        }
                }
                /* Copy out default acl's */
                if (dfaclbsize > 0) {
                        uaddrp += aclbsize;
                        if (copyout(vsecattr.vsa_dfaclentp,
                            uaddrp, dfaclbsize)) {
                                error = EFAULT;
                                goto errout;
                        }
                }
                *rv = numacls;
                if (vsecattr.vsa_aclcnt) {
                        kmem_free(vsecattr.vsa_aclentp,
                            vsecattr.vsa_aclcnt * sizeof (aclent_t));
                }
                if (vsecattr.vsa_dfaclcnt) {
                        kmem_free(vsecattr.vsa_dfaclentp,
                            vsecattr.vsa_dfaclcnt * sizeof (aclent_t));
                }
                break;

        case ACE_GETACL:
                if (aclbufp == NULL)
                        return (EFAULT);

                vsecattr.vsa_mask = VSA_ACE | VSA_ACECNT;
                if (error = VOP_GETSECATTR(vp, &vsecattr, 0, CRED(), NULL))
                        return (error);

                aclbsize = vsecattr.vsa_aclcnt * sizeof (ace_t);
                if (vsecattr.vsa_aclcnt > nentries) {
                        error = ENOSPC;
                        goto errout;
                }

                if (aclbsize > 0) {
                        if ((error = copyout(vsecattr.vsa_aclentp,
                            aclbufp, aclbsize)) != 0) {
                                goto errout;
                        }
                }

                *rv = vsecattr.vsa_aclcnt;
                if (vsecattr.vsa_aclcnt) {
                        kmem_free(vsecattr.vsa_aclentp, vsecattr.vsa_aclentsz);
                }
                break;

        case SETACL:
                /*
                 * Minimum ACL size is three entries so might as well
                 * bail out here.  Also limit request size to prevent user
                 * from allocating too much kernel memory.  Maximum size
                 * is MAX_ACL_ENTRIES for the ACL part and MAX_ACL_ENTRIES
                 * for the default ACL part. (bug 4058667)
                 */
                if (nentries < 3 || nentries > (MAX_ACL_ENTRIES * 2))
                        return (EINVAL);
                /*
                 * NULL output buffer is also an easy bail out.
                 */
                if (aclbufp == NULL)
                        return (EFAULT);
                vsecattr.vsa_mask = VSA_ACL;
                aclbsize = nentries * sizeof (aclent_t);
                vsecattr.vsa_aclentp = kmem_alloc(aclbsize, KM_SLEEP);
                aaclp = vsecattr.vsa_aclentp;
                vsecattr.vsa_aclcnt = nentries;
                uaddrp = (caddr_t)aclbufp;
                if (copyin(uaddrp, vsecattr.vsa_aclentp, aclbsize)) {
                        kmem_free(aaclp, aclbsize);
                        return (EFAULT);
                }
                /* Sort the acl list */
                ksort((caddr_t)vsecattr.vsa_aclentp,
                    vsecattr.vsa_aclcnt, sizeof (aclent_t), cmp2acls);

                /* Break into acl and default acl lists */
                for (numacls = 0, aclp = vsecattr.vsa_aclentp;
                    numacls < vsecattr.vsa_aclcnt;
                    aclp++, numacls++) {
                        if (aclp->a_type & ACL_DEFAULT)
                                break;
                }

                /* Find where defaults start (if any) */
                if (numacls < vsecattr.vsa_aclcnt) {
                        vsecattr.vsa_mask |= VSA_DFACL;
                        vsecattr.vsa_dfaclcnt = nentries - numacls;
                        vsecattr.vsa_dfaclentp = aclp;
                        vsecattr.vsa_aclcnt = numacls;
                }
                /* Adjust if they're all defaults */
                if (vsecattr.vsa_aclcnt == 0) {
                        vsecattr.vsa_mask &= ~VSA_ACL;
                        vsecattr.vsa_aclentp = NULL;
                }
                /* Only directories can have defaults */
                if (vsecattr.vsa_dfaclcnt && vp->v_type != VDIR) {
                        kmem_free(aaclp, aclbsize);
                        return (ENOTDIR);
                }
                (void) VOP_RWLOCK(vp, V_WRITELOCK_TRUE, NULL);
                if (error = VOP_SETSECATTR(vp, &vsecattr, 0, CRED(), NULL)) {
                        kmem_free(aaclp, aclbsize);
                        VOP_RWUNLOCK(vp, V_WRITELOCK_TRUE, NULL);
                        return (error);
                }

                /*
                 * Should return 0 upon success according to the man page
                 * and SVR4 semantics. (Bug #1214399: SETACL returns wrong rc)
                 */
                *rv = 0;
                kmem_free(aaclp, aclbsize);
                VOP_RWUNLOCK(vp, V_WRITELOCK_TRUE, NULL);
                break;

        case ACE_SETACL:
                if (nentries < 1 || nentries > MAX_ACL_ENTRIES)
                        return (EINVAL);

                if (aclbufp == NULL)
                        return (EFAULT);

                vsecattr.vsa_mask = VSA_ACE;
                aclbsize = nentries * sizeof (ace_t);
                vsecattr.vsa_aclentp = kmem_alloc(aclbsize, KM_SLEEP);
                aaclp = vsecattr.vsa_aclentp;
                vsecattr.vsa_aclcnt = nentries;
                vsecattr.vsa_aclentsz = aclbsize;
                uaddrp = (caddr_t)aclbufp;
                if (copyin(uaddrp, vsecattr.vsa_aclentp, aclbsize)) {
                        kmem_free(aaclp, aclbsize);
                        return (EFAULT);
                }
                (void) VOP_RWLOCK(vp, V_WRITELOCK_TRUE, NULL);
                if (error = VOP_SETSECATTR(vp, &vsecattr, 0, CRED(), NULL)) {
                        kmem_free(aaclp, aclbsize);
                        VOP_RWUNLOCK(vp, V_WRITELOCK_TRUE, NULL);
                        return (error);
                }
                *rv = 0;
                kmem_free(aaclp, aclbsize);
                VOP_RWUNLOCK(vp, V_WRITELOCK_TRUE, NULL);
                break;

        default:
                return (EINVAL);
        }

        return (0);

errout:
        if (aclbsize && vsecattr.vsa_aclentp)
                kmem_free(vsecattr.vsa_aclentp, aclbsize);
        if (dfaclbsize && vsecattr.vsa_dfaclentp)
                kmem_free(vsecattr.vsa_dfaclentp, dfaclbsize);
        return (error);
}