subst.c revision 307138 
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: stable/11/contrib/libarchive/tar/subst.c 307138 2016-10-12 10:28:22Z mm $");
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
47struct 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
54struct substitution {
55	struct subst_rule *first_rule, *last_rule;
56};
57
58static void
59init_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
69void
70add_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
166static void
167realloc_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
188static void
189realloc_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
209int
210apply_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
311void
312cleanup_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