1 /*-
2 * Copyright (c) 2008 Joerg Sonnenberger
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26 #include "bsdtar_platform.h"
27 __FBSDID("$FreeBSD: src/usr.bin/tar/subst.c,v 1.4 2008/06/15 10:08:16 kientzle Exp $");
28
29 #if defined(HAVE_REGEX_H) || defined(HAVE_PCREPOSIX_H)
30 #include "bsdtar.h"
31
32 #include <errno.h>
33 #ifdef HAVE_PCREPOSIX_H
34 #include <pcreposix.h>
35 #else
36 #include <regex.h>
37 #endif
38 #include <stdlib.h>
39 #include <string.h>
40
41 #ifndef REG_BASIC
42 #define REG_BASIC 0
43 #endif
44
45 #include "err.h"
46
47 struct subst_rule {
48 struct subst_rule *next;
49 regex_t re;
50 char *result;
51 unsigned int global:1, print:1, regular:1, symlink:1, hardlink:1;
52 };
53
54 struct substitution {
55 struct subst_rule *first_rule, *last_rule;
56 };
57
58 static void
init_substitution(struct bsdtar * bsdtar)59 init_substitution(struct bsdtar *bsdtar)
60 {
61 struct substitution *subst;
62
63 bsdtar->substitution = subst = malloc(sizeof(*subst));
64 if (subst == NULL)
65 lafe_errc(1, errno, "Out of memory");
66 subst->first_rule = subst->last_rule = NULL;
67 }
68
69 void
add_substitution(struct bsdtar * bsdtar,const char * rule_text)70 add_substitution(struct bsdtar *bsdtar, const char *rule_text)
71 {
72 struct subst_rule *rule;
73 struct substitution *subst;
74 const char *end_pattern, *start_subst;
75 char *pattern;
76 int r;
77
78 if ((subst = bsdtar->substitution) == NULL) {
79 init_substitution(bsdtar);
80 subst = bsdtar->substitution;
81 }
82
83 rule = malloc(sizeof(*rule));
84 if (rule == NULL)
85 lafe_errc(1, errno, "Out of memory");
86 rule->next = NULL;
87 rule->result = NULL;
88
89 if (subst->last_rule == NULL)
90 subst->first_rule = rule;
91 else
92 subst->last_rule->next = rule;
93 subst->last_rule = rule;
94
95 if (*rule_text == '\0')
96 lafe_errc(1, 0, "Empty replacement string");
97 end_pattern = strchr(rule_text + 1, *rule_text);
98 if (end_pattern == NULL)
99 lafe_errc(1, 0, "Invalid replacement string");
100
101 pattern = malloc(end_pattern - rule_text);
102 if (pattern == NULL)
103 lafe_errc(1, errno, "Out of memory");
104 memcpy(pattern, rule_text + 1, end_pattern - rule_text - 1);
105 pattern[end_pattern - rule_text - 1] = '\0';
106
107 if ((r = regcomp(&rule->re, pattern, REG_BASIC)) != 0) {
108 char buf[80];
109 regerror(r, &rule->re, buf, sizeof(buf));
110 lafe_errc(1, 0, "Invalid regular expression: %s", buf);
111 }
112 free(pattern);
113
114 start_subst = end_pattern + 1;
115 end_pattern = strchr(start_subst, *rule_text);
116 if (end_pattern == NULL)
117 lafe_errc(1, 0, "Invalid replacement string");
118
119 rule->result = malloc(end_pattern - start_subst + 1);
120 if (rule->result == NULL)
121 lafe_errc(1, errno, "Out of memory");
122 memcpy(rule->result, start_subst, end_pattern - start_subst);
123 rule->result[end_pattern - start_subst] = '\0';
124
125 /* Defaults */
126 rule->global = 0; /* Don't do multiple replacements. */
127 rule->print = 0; /* Don't print. */
128 rule->regular = 1; /* Rewrite regular filenames. */
129 rule->symlink = 1; /* Rewrite symlink targets. */
130 rule->hardlink = 1; /* Rewrite hardlink targets. */
131
132 while (*++end_pattern) {
133 switch (*end_pattern) {
134 case 'g':
135 case 'G':
136 rule->global = 1;
137 break;
138 case 'h':
139 rule->hardlink = 1;
140 break;
141 case 'H':
142 rule->hardlink = 0;
143 break;
144 case 'p':
145 case 'P':
146 rule->print = 1;
147 break;
148 case 'r':
149 rule->regular = 1;
150 break;
151 case 'R':
152 rule->regular = 0;
153 break;
154 case 's':
155 rule->symlink = 1;
156 break;
157 case 'S':
158 rule->symlink = 0;
159 break;
160 default:
161 lafe_errc(1, 0, "Invalid replacement flag %c", *end_pattern);
162 }
163 }
164 }
165
166 static void
realloc_strncat(char ** str,const char * append,size_t len)167 realloc_strncat(char **str, const char *append, size_t len)
168 {
169 char *new_str;
170 size_t old_len;
171
172 if (*str == NULL)
173 old_len = 0;
174 else
175 old_len = strlen(*str);
176
177 new_str = malloc(old_len + len + 1);
178 if (new_str == NULL)
179 lafe_errc(1, errno, "Out of memory");
180 if (*str != NULL)
181 memcpy(new_str, *str, old_len);
182 memcpy(new_str + old_len, append, len);
183 new_str[old_len + len] = '\0';
184 free(*str);
185 *str = new_str;
186 }
187
188 static void
realloc_strcat(char ** str,const char * append)189 realloc_strcat(char **str, const char *append)
190 {
191 char *new_str;
192 size_t old_len;
193
194 if (*str == NULL)
195 old_len = 0;
196 else
197 old_len = strlen(*str);
198
199 new_str = malloc(old_len + strlen(append) + 1);
200 if (new_str == NULL)
201 lafe_errc(1, errno, "Out of memory");
202 if (*str != NULL)
203 memcpy(new_str, *str, old_len);
204 strcpy(new_str + old_len, append);
205 free(*str);
206 *str = new_str;
207 }
208
209 int
apply_substitution(struct bsdtar * bsdtar,const char * name,char ** result,int symlink_target,int hardlink_target)210 apply_substitution(struct bsdtar *bsdtar, const char *name, char **result,
211 int symlink_target, int hardlink_target)
212 {
213 const char *path = name;
214 regmatch_t matches[10];
215 size_t i, j;
216 struct subst_rule *rule;
217 struct substitution *subst;
218 int c, got_match, print_match;
219
220 *result = NULL;
221
222 if ((subst = bsdtar->substitution) == NULL)
223 return 0;
224
225 got_match = 0;
226 print_match = 0;
227
228 for (rule = subst->first_rule; rule != NULL; rule = rule->next) {
229 if (symlink_target) {
230 if (!rule->symlink)
231 continue;
232 } else if (hardlink_target) {
233 if (!rule->hardlink)
234 continue;
235 } else { /* Regular filename. */
236 if (!rule->regular)
237 continue;
238 }
239
240 while (1) {
241 if (regexec(&rule->re, name, 10, matches, 0))
242 break;
243
244 got_match = 1;
245 print_match |= rule->print;
246 realloc_strncat(result, name, matches[0].rm_so);
247
248 for (i = 0, j = 0; rule->result[i] != '\0'; ++i) {
249 if (rule->result[i] == '~') {
250 realloc_strncat(result, rule->result + j, i - j);
251 realloc_strncat(result,
252 name + matches[0].rm_so,
253 matches[0].rm_eo - matches[0].rm_so);
254 j = i + 1;
255 continue;
256 }
257 if (rule->result[i] != '\\')
258 continue;
259
260 ++i;
261 c = rule->result[i];
262 switch (c) {
263 case '~':
264 case '\\':
265 realloc_strncat(result, rule->result + j, i - j - 1);
266 j = i;
267 break;
268 case '1':
269 case '2':
270 case '3':
271 case '4':
272 case '5':
273 case '6':
274 case '7':
275 case '8':
276 case '9':
277 realloc_strncat(result, rule->result + j, i - j - 1);
278 if ((size_t)(c - '0') > (size_t)(rule->re.re_nsub)) {
279 free(*result);
280 *result = NULL;
281 return -1;
282 }
283 realloc_strncat(result, name + matches[c - '0'].rm_so, matches[c - '0'].rm_eo - matches[c - '0'].rm_so);
284 j = i + 1;
285 break;
286 default:
287 /* Just continue; */
288 break;
289 }
290
291 }
292
293 realloc_strcat(result, rule->result + j);
294
295 name += matches[0].rm_eo;
296
297 if (!rule->global)
298 break;
299 }
300 }
301
302 if (got_match)
303 realloc_strcat(result, name);
304
305 if (print_match)
306 fprintf(stderr, "%s >> %s\n", path, *result);
307
308 return got_match;
309 }
310
311 void
cleanup_substitution(struct bsdtar * bsdtar)312 cleanup_substitution(struct bsdtar *bsdtar)
313 {
314 struct subst_rule *rule;
315 struct substitution *subst;
316
317 if ((subst = bsdtar->substitution) == NULL)
318 return;
319
320 while ((rule = subst->first_rule) != NULL) {
321 subst->first_rule = rule->next;
322 free(rule->result);
323 free(rule);
324 }
325 free(subst);
326 }
327 #endif /* defined(HAVE_REGEX_H) || defined(HAVE_PCREPOSIX_H) */
328