xref: /illumos-gate/usr/src/lib/libc/port/gen/readdir_r.c (revision ddb365bfc9e868ad24ccdcb0dc91af18b10df082)
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 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1988 AT&T	*/
28 /*	  All Rights Reserved  	*/
29 
30 /*
31  * readdir_r -- C library extension routine
32  */
33 
34 #include	<sys/feature_tests.h>
35 
36 #if !defined(_LP64)
37 #pragma weak _readdir64_r = readdir64_r
38 #endif
39 
40 #include "lint.h"
41 #include "libc.h"
42 #include <mtlib.h>
43 #include <unistd.h>
44 #include <dirent.h>
45 #include <string.h>
46 #include <limits.h>
47 #include <errno.h>
48 
49 #ifdef _LP64
50 
51 /*
52  * POSIX.1c standard version of the thread function readdir_r.
53  */
54 
55 int
56 readdir_r(DIR *dirp, dirent_t *entry, dirent_t **result)
57 {
58 	private_DIR *pdirp = (private_DIR *)dirp;
59 	dirent_t *dp;		/* -> directory data */
60 	int saveloc = 0;
61 
62 	lmutex_lock(&pdirp->dd_lock);
63 	if (dirp->dd_size != 0) {
64 		dp = (dirent_t *)(uintptr_t)&dirp->dd_buf[dirp->dd_loc];
65 		saveloc = dirp->dd_loc;		/* save for possible EOF */
66 		dirp->dd_loc += (int)dp->d_reclen;
67 	}
68 
69 	if (dirp->dd_loc >= dirp->dd_size)
70 		dirp->dd_loc = dirp->dd_size = 0;
71 
72 	if (dirp->dd_size == 0 &&	/* refill buffer */
73 	    (dirp->dd_size = getdents(dirp->dd_fd,
74 	    (dirent_t *)(uintptr_t)dirp->dd_buf, DIRBUF)) <= 0) {
75 		if (dirp->dd_size == 0) {	/* This means EOF */
76 			dirp->dd_loc = saveloc;	/* so save for telldir */
77 			lmutex_unlock(&pdirp->dd_lock);
78 			*result = NULL;
79 			return (0);
80 		}
81 		lmutex_unlock(&pdirp->dd_lock);
82 		*result = NULL;
83 		return (errno);		/* error */
84 	}
85 
86 	dp = (dirent_t *)(uintptr_t)&dirp->dd_buf[dirp->dd_loc];
87 	(void) memcpy(entry, dp, (size_t)dp->d_reclen);
88 	lmutex_unlock(&pdirp->dd_lock);
89 	*result = entry;
90 	return (0);
91 }
92 
93 #else	/* _LP64 */
94 
95 /*
96  * POSIX.1c standard version of the thr function readdir_r.
97  * Large file version.
98  */
99 
100 int
101 readdir64_r(DIR *dirp, dirent64_t *entry, dirent64_t **result)
102 {
103 	private_DIR *pdirp = (private_DIR *)(uintptr_t)dirp;
104 	dirent64_t *dp64;	/* -> directory data */
105 	int saveloc = 0;
106 
107 	lmutex_lock(&pdirp->dd_lock);
108 	if (dirp->dd_size != 0) {
109 		dp64 = (dirent64_t *)(uintptr_t)&dirp->dd_buf[dirp->dd_loc];
110 		/* was converted by readdir and needs to be reversed */
111 		if (dp64->d_ino == (ino64_t)-1) {
112 			dirent_t *dp32;	/* -> 32 bit directory data */
113 
114 			dp32 = (dirent_t *)(&dp64->d_off);
115 			dp64->d_ino = (ino64_t)dp32->d_ino;
116 			dp64->d_off = (off64_t)dp32->d_off;
117 			dp64->d_reclen = (unsigned short)(dp32->d_reclen +
118 			    ((char *)&dp64->d_off - (char *)dp64));
119 		}
120 		saveloc = dirp->dd_loc;		/* save for possible EOF */
121 		dirp->dd_loc += (int)dp64->d_reclen;
122 	}
123 
124 	if (dirp->dd_loc >= dirp->dd_size)
125 		dirp->dd_loc = dirp->dd_size = 0;
126 
127 	if (dirp->dd_size == 0 &&	/* refill buffer */
128 	    (dirp->dd_size = getdents64(dirp->dd_fd,
129 	    (dirent64_t *)(uintptr_t)dirp->dd_buf, DIRBUF)) <= 0) {
130 		if (dirp->dd_size == 0) {	/* This means EOF */
131 			dirp->dd_loc = saveloc;	/* so save for telldir */
132 			lmutex_unlock(&pdirp->dd_lock);
133 			*result = NULL;
134 			return (0);
135 		}
136 		lmutex_unlock(&pdirp->dd_lock);
137 		*result = NULL;
138 		return (errno);		/* error */
139 	}
140 
141 	dp64 = (dirent64_t *)(uintptr_t)&dirp->dd_buf[dirp->dd_loc];
142 	(void) memcpy(entry, dp64, (size_t)dp64->d_reclen);
143 	*result = entry;
144 	lmutex_unlock(&pdirp->dd_lock);
145 	return (0);
146 }
147 
148 /*
149  * POSIX.1c standard version of the function readdir_r.
150  * User gets it via static readdir_r from header file.
151  */
152 
153 int
154 __posix_readdir_r(DIR *dirp, dirent_t *entry, dirent_t **result)
155 {
156 	int error;
157 	dirent64_t *dp64;
158 	struct {
159 		dirent64_t dirent64;
160 		char chars[MAXNAMLEN];
161 	} buf;
162 
163 	error = readdir64_r(dirp, (dirent64_t *)&buf, &dp64);
164 	if (error != 0 || dp64 == NULL) {
165 		*result = NULL;
166 		return (error);
167 	}
168 
169 	if (dp64->d_ino > SIZE_MAX ||
170 	    (uint64_t)dp64->d_off > (uint64_t)UINT32_MAX) {
171 		*result = NULL;
172 		return (EOVERFLOW);
173 	}
174 
175 	entry->d_ino = (ino_t)dp64->d_ino;
176 	entry->d_off = (off_t)dp64->d_off;
177 	entry->d_reclen = (unsigned short)((((char *)entry->d_name -
178 	    (char *)entry) + strlen(dp64->d_name) + 1 + 3) & ~3);
179 	(void) strcpy(entry->d_name, dp64->d_name);
180 	*result = entry;
181 	return (0);
182 }
183 
184 /*
185  * POSIX.1c Draft-6 version of the function readdir_r.
186  * It was implemented by Solaris 2.3.
187  */
188 
189 dirent_t *
190 readdir_r(DIR *dirp, dirent_t *entry)
191 {
192 	int error;
193 	dirent_t *result;
194 
195 	if ((error = __posix_readdir_r(dirp, entry, &result)) != 0)
196 		errno = error;
197 	return (result);
198 }
199 
200 #endif	/* _LP64 */
201