xref: /titanic_41/usr/src/lib/libbc/libc/sys/common/getdents.c (revision 9e86db79b7d1bbc5f2f04e99954cbd5eae0e22bb)
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, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 1994 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 #include <unistd.h>
30 #include <sys/types.h>
31 #include <sys/dirent.h>
32 #include <sys/syscall.h>
33 #include <sys/param.h>
34 #include <sys/errno.h>
35 
36 #define	ALIGN	4
37 
38 extern int errno;
39 
40 struct n_dirent{
41 	unsigned long	d_ino;
42 	long		d_off;
43 	unsigned short	d_reclen;
44 	char		d_name[1];
45 };
46 
47 
48 int getdents(fd, buf, bytes)
49 int fd;
50 char *buf;
51 int bytes;
52 {
53 	return(bc_getdents(fd, buf, bytes));
54 }
55 
56 
57 int bc_getdents(fd, buf, bytes)
58 int fd;
59 char *buf;
60 int bytes;
61 {
62 	int ret, nbytes;
63 	char *nbuf;
64 	struct dirent *dir;
65 	struct n_dirent *ndir;
66 	int count=0;
67 	off_t last_off;
68 
69 	if (buf == (char *)0 || buf == (char *)-1) {
70 		errno = EFAULT;
71 		return(-1);
72 	}
73 
74 	nbytes = bytes; /* buffer can only be as large as user expects */
75 
76 	if ((nbuf = (char *)malloc(nbytes)) == NULL) {
77 		return(-1);
78 	}
79 
80 	if ((ret = _syscall(SYS_getdents, fd, nbuf, nbytes)) == -1) {
81 		free(nbuf);
82 		return(ret);
83 	}
84 
85 
86 	dir = (struct dirent *)buf;
87 	ndir = (struct n_dirent *)nbuf;	/* source directory format */
88 
89 	while ((((int)(((char *)dir) + sizeof(struct n_dirent) +
90 	    strlen(ndir->d_name) + ALIGN) & ~(ALIGN - 1)) <
91 	    (int)(buf + bytes)) &&
92 	    ((char *)ndir + sizeof(struct n_dirent) <= (nbuf + ret))) {
93 		dir->d_off = ndir->d_off;
94 		dir->d_fileno = ndir->d_ino;	/* NOT VALID */
95 		dir->d_namlen = strlen(ndir->d_name);
96 		dir->d_reclen = (short)((sizeof(struct dirent) - MAXNAMLEN +
97 		    dir->d_namlen + ALIGN) & -ALIGN);
98 		strncpy(dir->d_name, ndir->d_name, dir->d_namlen);
99 		dir->d_name[dir->d_namlen] = '\0';
100 		count += dir->d_reclen;
101 		last_off = ndir->d_off;
102 		dir  = (struct dirent *)((char *)dir +
103 				    ((int)( dir->d_reclen)));
104 		ndir = (struct n_dirent *)((char *)ndir +
105 				    ((int)(ndir->d_reclen)));
106 	}
107 
108 	/*
109 	 * Seek to the next entry in the directory. If all entries
110 	 * in ndir were not copied to dir, the next getdents syscall
111 	 * will start reading from there.
112 	 */
113 	(void)lseek(fd, last_off, SEEK_SET);
114 	free(nbuf);
115 	return(count);
116 }
117