xref: /titanic_52/usr/src/lib/libbc/libc/sys/common/getdents.c (revision 7c478bd95313f5f23a4c958a745db2134aa03244)

/*
 * 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 1994 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

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

#include <unistd.h>
#include <sys/types.h>
#include <sys/dirent.h>
#include <sys/syscall.h>
#include <sys/param.h>
#include <sys/errno.h>

#define	ALIGN	4

extern int errno;

struct n_dirent{
	unsigned long	d_ino;
	long		d_off;
	unsigned short	d_reclen;
	char		d_name[1];
};


int getdents(fd, buf, bytes)
int fd;
char *buf;
int bytes;
{
	return(bc_getdents(fd, buf, bytes));
}


int bc_getdents(fd, buf, bytes)
int fd;
char *buf;
int bytes;
{
	int ret, nbytes;
	char *nbuf;
	struct dirent *dir;
	struct n_dirent *ndir;
	int count=0;
	off_t last_off;

	if (buf == (char *)0 || buf == (char *)-1) {
		errno = EFAULT;
		return(-1);
	}

	nbytes = bytes; /* buffer can only be as large as user expects */

	if ((nbuf = (char *)malloc(nbytes)) == NULL) {
		return(-1);
	}

	if ((ret = _syscall(SYS_getdents, fd, nbuf, nbytes)) == -1) {
		free(nbuf);
		return(ret);
	}


	dir = (struct dirent *)buf;
	ndir = (struct n_dirent *)nbuf;	/* source directory format */

	while ((((int)(((char *)dir) + sizeof(struct n_dirent) +
	    strlen(ndir->d_name) + ALIGN) & ~(ALIGN - 1)) <
	    (int)(buf + bytes)) &&
	    ((char *)ndir + sizeof(struct n_dirent) <= (nbuf + ret))) {
		dir->d_off = ndir->d_off;
		dir->d_fileno = ndir->d_ino;	/* NOT VALID */
		dir->d_namlen = strlen(ndir->d_name);
		dir->d_reclen = (short)((sizeof(struct dirent) - MAXNAMLEN +
		    dir->d_namlen + ALIGN) & -ALIGN);
		strncpy(dir->d_name, ndir->d_name, dir->d_namlen);
		dir->d_name[dir->d_namlen] = '\0';
		count += dir->d_reclen;
		last_off = ndir->d_off;
		dir  = (struct dirent *)((char *)dir +
				    ((int)( dir->d_reclen)));
		ndir = (struct n_dirent *)((char *)ndir +
				    ((int)(ndir->d_reclen)));
	}

	/*
	 * Seek to the next entry in the directory. If all entries
	 * in ndir were not copied to dir, the next getdents syscall
	 * will start reading from there.
	 */
	(void)lseek(fd, last_off, SEEK_SET);
	free(nbuf);
	return(count);
}