1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 
  22 /*
  23  * Copyright (c) 1994, 2010, Oracle and/or its affiliates. All rights reserved.
  24  * Copyright 2017 Nexenta Systems, Inc.  All rights reserved.
  25  */
  26 
  27 /*      Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */
  28 /*        All Rights Reserved   */
  29 
  30 /*
  31  * Portions of this source code were derived from Berkeley 4.3 BSD
  32  * under license from the Regents of the University of California.
  33  */
  34 
  35 #include <sys/param.h>
  36 #include <sys/isa_defs.h>
  37 #include <sys/types.h>
  38 #include <sys/inttypes.h>
  39 #include <sys/sysmacros.h>
  40 #include <sys/cred.h>
  41 #include <sys/dirent.h>
  42 #include <sys/systm.h>
  43 #include <sys/errno.h>
  44 #include <sys/vnode.h>
  45 #include <sys/file.h>
  46 #include <sys/mode.h>
  47 #include <sys/uio.h>
  48 #include <sys/filio.h>
  49 #include <sys/debug.h>
  50 #include <sys/kmem.h>
  51 #include <sys/cmn_err.h>
  52 
  53 /*
  54  * Returns count of dir entries, or -errno
  55  */
  56 int
  57 fake_getdents(vnode_t *vp, offset_t *offp, void *buf, size_t count)
  58 {
  59         struct uio auio;
  60         struct iovec aiov;
  61         register int error;
  62         int sink;
  63 
  64         if (count < sizeof (struct dirent64))
  65                 return (-EINVAL);
  66 
  67         /*
  68          * Don't let the user overcommit kernel resources.
  69          */
  70         if (count > MAXGETDENTS_SIZE)
  71                 count = MAXGETDENTS_SIZE;
  72 
  73         if (vp->v_type != VDIR) {
  74                 return (-ENOTDIR);
  75         }
  76 
  77         aiov.iov_base = buf;
  78         aiov.iov_len = count;
  79         auio.uio_iov = &aiov;
  80         auio.uio_iovcnt = 1;
  81         auio.uio_loffset = *offp;
  82         auio.uio_segflg = UIO_USERSPACE;
  83         auio.uio_resid = count;
  84         auio.uio_fmode = 0;
  85         auio.uio_extflg = UIO_COPY_CACHED;
  86         (void) VOP_RWLOCK(vp, V_WRITELOCK_FALSE, NULL);
  87         error = VOP_READDIR(vp, &auio, CRED(), &sink, NULL, 0);
  88         VOP_RWUNLOCK(vp, V_WRITELOCK_FALSE, NULL);
  89         if (error) {
  90                 return (-error);
  91         }
  92         count = count - auio.uio_resid;
  93         *offp = auio.uio_loffset;
  94 
  95         return (count);
  96 }