common/syscall/acl.c

	acl.c revision fa9e4066f08beec538e775443c5be79dd423fcab
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (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 2005 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.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

#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>

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;

    /* 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)
            goto lookup;
        return (set_errno(error));
    }

    error = cacl(cmd, nentries, aclbufp, vp, &rv);
    VN_RELE(vp);
    if (error) {
        if (error == ESTALE)
            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));
#ifdef C2_AUDIT
    if (fp->f_flag & FREVOKED) {
        releasef(fdes);
        return (set_errno(EBADF));
    }
#endif /* C2_AUDIT */

    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;

    ASSERT(vp);

    bzero(&vsecattr, sizeof (vsecattr_t));

    switch (cmd) {

    case ACE_GETACLCNT:
    case GETACLCNT:
        if (cmd == GETACLCNT)
            vsecattr.vsa_mask = VSA_ACLCNT | VSA_DFACLCNT;
        else
            vsecattr.vsa_mask = VSA_ACECNT;
        if (error = VOP_GETSECATTR(vp, &vsecattr, 0, CRED()))
            return (error);
        *rv = vsecattr.vsa_aclcnt + vsecattr.vsa_dfaclcnt;
        if (vsecattr.vsa_aclcnt && vsecattr.vsa_aclentp) {
            kmem_free(vsecattr.vsa_aclentp,
                vsecattr.vsa_aclcnt * sizeof (aclent_t));
        }
        if (vsecattr.vsa_dfaclcnt && vsecattr.vsa_dfaclentp) {
            kmem_free(vsecattr.vsa_dfaclentp,
                vsecattr.vsa_dfaclcnt * sizeof (aclent_t));
        }
        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()))
            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()))
            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_aclcnt * sizeof (ace_t));
        }
        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())) {
            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 > (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;
        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())) {
            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);
}