xref: /illumos-gate/usr/src/lib/libc/port/gen/readdir_r.c (revision 9113a79cf228b8f7bd509b1328adf88659dfe218)
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 2007 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 /*	Copyright (c) 1988 AT&T	*/
30 /*	  All Rights Reserved  	*/
31 
32 /*
33  * readdir_r -- C library extension routine
34  */
35 
36 #include	<sys/feature_tests.h>
37 
38 #if !defined(_LP64)
39 #pragma weak readdir64_r = _readdir64_r
40 #endif
41 #pragma weak readdir_r = _readdir_r
42 
43 #include "synonyms.h"
44 #include "libc.h"
45 #include <mtlib.h>
46 #include <unistd.h>
47 #include <dirent.h>
48 #include <string.h>
49 #include <limits.h>
50 #include <errno.h>
51 
52 #ifdef _LP64
53 
54 /*
55  * POSIX.1c standard version of the thread function readdir_r.
56  */
57 
58 int
59 readdir_r(DIR *dirp, dirent_t *entry, dirent_t **result)
60 {
61 	private_DIR *pdirp = (private_DIR *)dirp;
62 	dirent_t *dp;		/* -> directory data */
63 	int saveloc = 0;
64 
65 	lmutex_lock(&pdirp->dd_lock);
66 	if (dirp->dd_size != 0) {
67 		dp = (dirent_t *)(uintptr_t)&dirp->dd_buf[dirp->dd_loc];
68 		saveloc = dirp->dd_loc;		/* save for possible EOF */
69 		dirp->dd_loc += (int)dp->d_reclen;
70 	}
71 
72 	if (dirp->dd_loc >= dirp->dd_size)
73 		dirp->dd_loc = dirp->dd_size = 0;
74 
75 	if (dirp->dd_size == 0 &&	/* refill buffer */
76 	    (dirp->dd_size = getdents(dirp->dd_fd,
77 	    (dirent_t *)(uintptr_t)dirp->dd_buf, DIRBUF)) <= 0) {
78 		if (dirp->dd_size == 0) {	/* This means EOF */
79 			dirp->dd_loc = saveloc;	/* so save for telldir */
80 			lmutex_unlock(&pdirp->dd_lock);
81 			*result = NULL;
82 			return (0);
83 		}
84 		lmutex_unlock(&pdirp->dd_lock);
85 		*result = NULL;
86 		return (errno);		/* error */
87 	}
88 
89 	dp = (dirent_t *)(uintptr_t)&dirp->dd_buf[dirp->dd_loc];
90 	(void) memcpy(entry, dp, (size_t)dp->d_reclen);
91 	lmutex_unlock(&pdirp->dd_lock);
92 	*result = entry;
93 	return (0);
94 }
95 
96 #else	/* _LP64 */
97 
98 /*
99  * POSIX.1c standard version of the thr function readdir_r.
100  * Large file version.
101  */
102 
103 int
104 readdir64_r(DIR *dirp, dirent64_t *entry, dirent64_t **result)
105 {
106 	private_DIR *pdirp = (private_DIR *)(uintptr_t)dirp;
107 	dirent64_t *dp64;	/* -> directory data */
108 	int saveloc = 0;
109 
110 	lmutex_lock(&pdirp->dd_lock);
111 	if (dirp->dd_size != 0) {
112 		dp64 = (dirent64_t *)(uintptr_t)&dirp->dd_buf[dirp->dd_loc];
113 		/* was converted by readdir and needs to be reversed */
114 		if (dp64->d_ino == (ino64_t)-1) {
115 			dirent_t *dp32;	/* -> 32 bit directory data */
116 
117 			dp32 = (dirent_t *)(&dp64->d_off);
118 			dp64->d_ino = (ino64_t)dp32->d_ino;
119 			dp64->d_off = (off64_t)dp32->d_off;
120 			dp64->d_reclen = (unsigned short)(dp32->d_reclen +
121 			    ((char *)&dp64->d_off - (char *)dp64));
122 		}
123 		saveloc = dirp->dd_loc;		/* save for possible EOF */
124 		dirp->dd_loc += (int)dp64->d_reclen;
125 	}
126 
127 	if (dirp->dd_loc >= dirp->dd_size)
128 		dirp->dd_loc = dirp->dd_size = 0;
129 
130 	if (dirp->dd_size == 0 &&	/* refill buffer */
131 	    (dirp->dd_size = getdents64(dirp->dd_fd,
132 	    (dirent64_t *)(uintptr_t)dirp->dd_buf, DIRBUF)) <= 0) {
133 		if (dirp->dd_size == 0) {	/* This means EOF */
134 			dirp->dd_loc = saveloc;	/* so save for telldir */
135 			lmutex_unlock(&pdirp->dd_lock);
136 			*result = NULL;
137 			return (0);
138 		}
139 		lmutex_unlock(&pdirp->dd_lock);
140 		*result = NULL;
141 		return (errno);		/* error */
142 	}
143 
144 	dp64 = (dirent64_t *)(uintptr_t)&dirp->dd_buf[dirp->dd_loc];
145 	(void) memcpy(entry, dp64, (size_t)dp64->d_reclen);
146 	*result = entry;
147 	lmutex_unlock(&pdirp->dd_lock);
148 	return (0);
149 }
150 
151 /*
152  * POSIX.1c standard version of the function readdir_r.
153  * User gets it via static readdir_r from header file.
154  */
155 
156 int
157 __posix_readdir_r(DIR *dirp, dirent_t *entry, dirent_t **result)
158 {
159 	int error;
160 	dirent64_t *dp64;
161 	struct {
162 		dirent64_t dirent64;
163 		char chars[MAXNAMLEN];
164 	} buf;
165 
166 	error = readdir64_r(dirp, (dirent64_t *)&buf, &dp64);
167 	if (error != 0 || dp64 == NULL) {
168 		*result = NULL;
169 		return (error);
170 	}
171 
172 	if (dp64->d_ino > SIZE_MAX ||
173 	    (uint64_t)dp64->d_off > (uint64_t)UINT32_MAX) {
174 		*result = NULL;
175 		return (EOVERFLOW);
176 	}
177 
178 	entry->d_ino = (ino_t)dp64->d_ino;
179 	entry->d_off = (off_t)dp64->d_off;
180 	entry->d_reclen = (unsigned short)((((char *)entry->d_name -
181 	    (char *)entry) + strlen(dp64->d_name) + 1 + 3) & ~3);
182 	(void) strcpy(entry->d_name, dp64->d_name);
183 	*result = entry;
184 	return (0);
185 }
186 
187 /*
188  * POSIX.1c Draft-6 version of the function readdir_r.
189  * It was implemented by Solaris 2.3.
190  */
191 
192 dirent_t *
193 readdir_r(DIR *dirp, dirent_t *entry)
194 {
195 	int error;
196 	dirent_t *result;
197 
198 	if ((error = __posix_readdir_r(dirp, entry, &result)) != 0)
199 		errno = error;
200 	return (result);
201 }
202 
203 #endif	/* _LP64 */
204