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compat_getdents.c revision 1.5 
      1 /*	$NetBSD: compat_getdents.c,v 1.5 2012/03/13 21:13:32 christos Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2005 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Christos Zoulas.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 #include <sys/cdefs.h>
     33 #if defined(LIBC_SCCS) && !defined(lint)
     34 __RCSID("$NetBSD: compat_getdents.c,v 1.5 2012/03/13 21:13:32 christos Exp $");
     35 #endif /* LIBC_SCCS and not lint */
     36 
     37 #define __LIBC12_SOURCE__
     38 
     39 #include "namespace.h"
     40 #include <sys/types.h>
     41 #include <dirent.h>
     42 #include <compat/include/dirent.h>
     43 #include <string.h>
     44 
     45 /*
     46  * libc12 compatible getdents routine.
     47  */
     48 int
     49 getdents(int fd, char *buf, size_t nbytes)
     50 {
     51 	struct dirent *ndp, *nndp, *endp;
     52 	struct dirent12 *odp;
     53 	ino_t ino;
     54 	int rv;
     55 	size_t len;
     56 
     57 	if ((rv = __getdents30(fd, buf, nbytes)) == -1)
     58 		return rv;
     59 
     60 	odp = (struct dirent12 *)(void *)buf;
     61 	ndp = (struct dirent *)(void *)buf;
     62 	endp = (struct dirent *)(void *)&buf[rv];
     63 
     64 	/*
     65 	 * In-place conversion. This works because odp
     66 	 * is smaller than ndp, but it has to be done
     67 	 * in the right sequence.
     68 	 */
     69 	for (; ndp < endp; ndp = nndp) {
     70 		nndp = _DIRENT_NEXT(ndp);
     71 		/* XXX: avoid unaligned 64-bit access on sparc64 */
     72 		/* XXX: does this work? */
     73 		memcpy(&ino, &ndp->d_ino, sizeof(ino_t));
     74 		odp->d_ino = (uint32_t)ino;
     75 		if (ndp->d_namlen >= sizeof(odp->d_name))
     76 			odp->d_namlen = sizeof(odp->d_name) - 1;
     77 		else
     78 			odp->d_namlen = (u_int8_t)ndp->d_namlen;
     79 		odp->d_type = ndp->d_type;
     80 		(void)memcpy(odp->d_name, ndp->d_name, (size_t)odp->d_namlen);
     81 		odp->d_name[odp->d_namlen] = '\0';
     82 		len = _DIRENT_SIZE(odp);
     83 		_DIAGASSERT(__type_fit(uint16_t, len));
     84 		odp->d_reclen = (uint16_t)len;
     85 		odp = _DIRENT_NEXT(odp);
     86 	}
     87 	ptrdiff_t td = (((char *)(void *)odp) - buf);
     88 	_DIAGASSERT(__type_fit(int, td));
     89 	return (int)td;
     90 }
     91