1 /* $NetBSD: dir.c,v 1.1 2024/02/18 20:57:56 christos Exp $ */
2
3 /*
4 * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
5 *
6 * SPDX-License-Identifier: MPL-2.0
7 *
8 * This Source Code Form is subject to the terms of the Mozilla Public
9 * License, v. 2.0. If a copy of the MPL was not distributed with this
10 * file, you can obtain one at https://mozilla.org/MPL/2.0/.
11 *
12 * See the COPYRIGHT file distributed with this work for additional
13 * information regarding copyright ownership.
14 */
15
16 /*! \file */
17
18 #include <ctype.h>
19 #include <errno.h>
20 #include <sys/stat.h>
21 #include <sys/types.h>
22 #include <unistd.h>
23
24 #include <isc/dir.h>
25 #include <isc/magic.h>
26 #include <isc/netdb.h>
27 #include <isc/print.h>
28 #include <isc/string.h>
29 #include <isc/util.h>
30
31 #include "errno2result.h"
32
33 #define ISC_DIR_MAGIC ISC_MAGIC('D', 'I', 'R', '*')
34 #define VALID_DIR(dir) ISC_MAGIC_VALID(dir, ISC_DIR_MAGIC)
35
36 void
isc_dir_init(isc_dir_t * dir)37 isc_dir_init(isc_dir_t *dir) {
38 REQUIRE(dir != NULL);
39
40 dir->entry.name[0] = '\0';
41 dir->entry.length = 0;
42
43 dir->handle = NULL;
44
45 dir->magic = ISC_DIR_MAGIC;
46 }
47
48 /*!
49 * \brief Allocate workspace and open directory stream. If either one fails,
50 * NULL will be returned.
51 */
52 isc_result_t
isc_dir_open(isc_dir_t * dir,const char * dirname)53 isc_dir_open(isc_dir_t *dir, const char *dirname) {
54 char *p;
55 isc_result_t result = ISC_R_SUCCESS;
56
57 REQUIRE(VALID_DIR(dir));
58 REQUIRE(dirname != NULL);
59
60 /*
61 * Copy directory name. Need to have enough space for the name,
62 * a possible path separator, the wildcard, and the final NUL.
63 */
64 if (strlen(dirname) + 3 > sizeof(dir->dirname)) {
65 /* XXXDCL ? */
66 return (ISC_R_NOSPACE);
67 }
68 strlcpy(dir->dirname, dirname, sizeof(dir->dirname));
69
70 /*
71 * Append path separator, if needed, and "*".
72 */
73 p = dir->dirname + strlen(dir->dirname);
74 if (dir->dirname < p && *(p - 1) != '/') {
75 *p++ = '/';
76 }
77 *p++ = '*';
78 *p = '\0';
79
80 /*
81 * Open stream.
82 */
83 dir->handle = opendir(dirname);
84
85 if (dir->handle == NULL) {
86 return (isc__errno2result(errno));
87 }
88
89 return (result);
90 }
91
92 /*!
93 * \brief Return previously retrieved file or get next one.
94 *
95 * Unix's dirent has
96 * separate open and read functions, but the Win32 and DOS interfaces open
97 * the dir stream and reads the first file in one operation.
98 */
99 isc_result_t
isc_dir_read(isc_dir_t * dir)100 isc_dir_read(isc_dir_t *dir) {
101 struct dirent *entry;
102
103 REQUIRE(VALID_DIR(dir) && dir->handle != NULL);
104
105 /*
106 * Fetch next file in directory.
107 */
108 entry = readdir(dir->handle);
109
110 if (entry == NULL) {
111 return (ISC_R_NOMORE);
112 }
113
114 /*
115 * Make sure that the space for the name is long enough.
116 */
117 if (sizeof(dir->entry.name) <= strlen(entry->d_name)) {
118 return (ISC_R_UNEXPECTED);
119 }
120
121 strlcpy(dir->entry.name, entry->d_name, sizeof(dir->entry.name));
122
123 /*
124 * Some dirents have d_namlen, but it is not portable.
125 */
126 dir->entry.length = strlen(entry->d_name);
127
128 return (ISC_R_SUCCESS);
129 }
130
131 /*!
132 * \brief Close directory stream.
133 */
134 void
isc_dir_close(isc_dir_t * dir)135 isc_dir_close(isc_dir_t *dir) {
136 REQUIRE(VALID_DIR(dir) && dir->handle != NULL);
137
138 (void)closedir(dir->handle);
139 dir->handle = NULL;
140 }
141
142 /*!
143 * \brief Reposition directory stream at start.
144 */
145 isc_result_t
isc_dir_reset(isc_dir_t * dir)146 isc_dir_reset(isc_dir_t *dir) {
147 REQUIRE(VALID_DIR(dir) && dir->handle != NULL);
148
149 rewinddir(dir->handle);
150
151 return (ISC_R_SUCCESS);
152 }
153
154 isc_result_t
isc_dir_chdir(const char * dirname)155 isc_dir_chdir(const char *dirname) {
156 /*!
157 * \brief Change the current directory to 'dirname'.
158 */
159
160 REQUIRE(dirname != NULL);
161
162 if (chdir(dirname) < 0) {
163 return (isc__errno2result(errno));
164 }
165
166 return (ISC_R_SUCCESS);
167 }
168
169 isc_result_t
isc_dir_chroot(const char * dirname)170 isc_dir_chroot(const char *dirname) {
171 #ifdef HAVE_CHROOT
172 void *tmp;
173 #endif /* ifdef HAVE_CHROOT */
174
175 REQUIRE(dirname != NULL);
176
177 #ifdef HAVE_CHROOT
178 /*
179 * Try to use getservbyname and getprotobyname before chroot.
180 * If WKS records are used in a zone under chroot, Name Service Switch
181 * may fail to load library in chroot.
182 * Do not report errors if it fails, we do not need any result now.
183 */
184 tmp = getprotobyname("udp");
185 if (tmp != NULL) {
186 (void)getservbyname("domain", "udp");
187 }
188
189 if (chroot(dirname) < 0 || chdir("/") < 0) {
190 return (isc__errno2result(errno));
191 }
192
193 return (ISC_R_SUCCESS);
194 #else /* ifdef HAVE_CHROOT */
195 return (ISC_R_NOTIMPLEMENTED);
196 #endif /* ifdef HAVE_CHROOT */
197 }
198
199 isc_result_t
isc_dir_createunique(char * templet)200 isc_dir_createunique(char *templet) {
201 isc_result_t result;
202 char *x;
203 char *p;
204 int i;
205 int pid;
206
207 REQUIRE(templet != NULL);
208
209 /*!
210 * \brief mkdtemp is not portable, so this emulates it.
211 */
212
213 pid = getpid();
214
215 /*
216 * Replace trailing Xs with the process-id, zero-filled.
217 */
218 for (x = templet + strlen(templet) - 1; *x == 'X' && x >= templet;
219 x--, pid /= 10)
220 {
221 *x = pid % 10 + '0';
222 }
223
224 x++; /* Set x to start of ex-Xs. */
225
226 do {
227 i = mkdir(templet, 0700);
228 if (i == 0 || errno != EEXIST) {
229 break;
230 }
231
232 /*
233 * The BSD algorithm.
234 */
235 p = x;
236 while (*p != '\0') {
237 if (isdigit((unsigned char)*p)) {
238 *p = 'a';
239 } else if (*p != 'z') {
240 ++*p;
241 } else {
242 /*
243 * Reset character and move to next.
244 */
245 *p++ = 'a';
246 continue;
247 }
248
249 break;
250 }
251
252 if (*p == '\0') {
253 /*
254 * Tried all combinations. errno should already
255 * be EEXIST, but ensure it is anyway for
256 * isc__errno2result().
257 */
258 errno = EEXIST;
259 break;
260 }
261 } while (1);
262
263 if (i == -1) {
264 result = isc__errno2result(errno);
265 } else {
266 result = ISC_R_SUCCESS;
267 }
268
269 return (result);
270 }
271