subst.c revision 302001 
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/10/contrib/libarchive/tar/subst.c 302001 2016-06-17 22:40:10Z 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
88	if (subst->last_rule == NULL)
89		subst->first_rule = rule;
90	else
91		subst->last_rule->next = rule;
92	subst->last_rule = rule;
93
94	if (*rule_text == '\0')
95		lafe_errc(1, 0, "Empty replacement string");
96	end_pattern = strchr(rule_text + 1, *rule_text);
97	if (end_pattern == NULL)
98		lafe_errc(1, 0, "Invalid replacement string");
99
100	pattern = malloc(end_pattern - rule_text);
101	if (pattern == NULL)
102		lafe_errc(1, errno, "Out of memory");
103	memcpy(pattern, rule_text + 1, end_pattern - rule_text - 1);
104	pattern[end_pattern - rule_text - 1] = '\0';
105
106	if ((r = regcomp(&rule->re, pattern, REG_BASIC)) != 0) {
107		char buf[80];
108		regerror(r, &rule->re, buf, sizeof(buf));
109		lafe_errc(1, 0, "Invalid regular expression: %s", buf);
110	}
111	free(pattern);
112
113	start_subst = end_pattern + 1;
114	end_pattern = strchr(start_subst, *rule_text);
115	if (end_pattern == NULL)
116		lafe_errc(1, 0, "Invalid replacement string");
117
118	rule->result = malloc(end_pattern - start_subst + 1);
119	if (rule->result == NULL)
120		lafe_errc(1, errno, "Out of memory");
121	memcpy(rule->result, start_subst, end_pattern - start_subst);
122	rule->result[end_pattern - start_subst] = '\0';
123
124	/* Defaults */
125	rule->global = 0; /* Don't do multiple replacements. */
126	rule->print = 0; /* Don't print. */
127	rule->regular = 1; /* Rewrite regular filenames. */
128	rule->symlink = 1; /* Rewrite symlink targets. */
129	rule->hardlink = 1; /* Rewrite hardlink targets. */
130
131	while (*++end_pattern) {
132		switch (*end_pattern) {
133		case 'g':
134		case 'G':
135			rule->global = 1;
136			break;
137		case 'h':
138			rule->hardlink = 1;
139			break;
140		case 'H':
141			rule->hardlink = 0;
142			break;
143		case 'p':
144		case 'P':
145			rule->print = 1;
146			break;
147		case 'r':
148			rule->regular = 1;
149			break;
150		case 'R':
151			rule->regular = 0;
152			break;
153		case 's':
154			rule->symlink = 1;
155			break;
156		case 'S':
157			rule->symlink = 0;
158			break;
159		default:
160			lafe_errc(1, 0, "Invalid replacement flag %c", *end_pattern);
161		}
162	}
163}
164
165static void
166realloc_strncat(char **str, const char *append, size_t len)
167{
168	char *new_str;
169	size_t old_len;
170
171	if (*str == NULL)
172		old_len = 0;
173	else
174		old_len = strlen(*str);
175
176	new_str = malloc(old_len + len + 1);
177	if (new_str == NULL)
178		lafe_errc(1, errno, "Out of memory");
179	if (*str != NULL)
180		memcpy(new_str, *str, old_len);
181	memcpy(new_str + old_len, append, len);
182	new_str[old_len + len] = '\0';
183	free(*str);
184	*str = new_str;
185}
186
187static void
188realloc_strcat(char **str, const char *append)
189{
190	char *new_str;
191	size_t old_len;
192
193	if (*str == NULL)
194		old_len = 0;
195	else
196		old_len = strlen(*str);
197
198	new_str = malloc(old_len + strlen(append) + 1);
199	if (new_str == NULL)
200		lafe_errc(1, errno, "Out of memory");
201	if (*str != NULL)
202		memcpy(new_str, *str, old_len);
203	strcpy(new_str + old_len, append);
204	free(*str);
205	*str = new_str;
206}
207
208int
209apply_substitution(struct bsdtar *bsdtar, const char *name, char **result,
210    int symlink_target, int hardlink_target)
211{
212	const char *path = name;
213	regmatch_t matches[10];
214	size_t i, j;
215	struct subst_rule *rule;
216	struct substitution *subst;
217	int c, got_match, print_match;
218
219	*result = NULL;
220
221	if ((subst = bsdtar->substitution) == NULL)
222		return 0;
223
224	got_match = 0;
225	print_match = 0;
226
227	for (rule = subst->first_rule; rule != NULL; rule = rule->next) {
228		if (symlink_target) {
229			if (!rule->symlink)
230				continue;
231		} else if (hardlink_target) {
232			if (!rule->hardlink)
233				continue;
234		} else { /* Regular filename. */
235			if (!rule->regular)
236				continue;
237		}
238
239		while (1) {
240			if (regexec(&rule->re, name, 10, matches, 0))
241				break;
242
243			got_match = 1;
244			print_match |= rule->print;
245			realloc_strncat(result, name, matches[0].rm_so);
246
247			for (i = 0, j = 0; rule->result[i] != '\0'; ++i) {
248				if (rule->result[i] == '~') {
249					realloc_strncat(result, rule->result + j, i - j);
250					realloc_strncat(result,
251					    name + matches[0].rm_so,
252					    matches[0].rm_eo - matches[0].rm_so);
253					j = i + 1;
254					continue;
255				}
256				if (rule->result[i] != '\\')
257					continue;
258
259				++i;
260				c = rule->result[i];
261				switch (c) {
262				case '~':
263				case '\\':
264					realloc_strncat(result, rule->result + j, i - j - 1);
265					j = i;
266					break;
267				case '1':
268				case '2':
269				case '3':
270				case '4':
271				case '5':
272				case '6':
273				case '7':
274				case '8':
275				case '9':
276					realloc_strncat(result, rule->result + j, i - j - 1);
277					if ((size_t)(c - '0') > (size_t)(rule->re.re_nsub)) {
278						free(*result);
279						*result = NULL;
280						return -1;
281					}
282					realloc_strncat(result, name + matches[c - '0'].rm_so, matches[c - '0'].rm_eo - matches[c - '0'].rm_so);
283					j = i + 1;
284					break;
285				default:
286					/* Just continue; */
287					break;
288				}
289
290			}
291
292			realloc_strcat(result, rule->result + j);
293
294			name += matches[0].rm_eo;
295
296			if (!rule->global)
297				break;
298		}
299	}
300
301	if (got_match)
302		realloc_strcat(result, name);
303
304	if (print_match)
305		fprintf(stderr, "%s >> %s\n", path, *result);
306
307	return got_match;
308}
309
310void
311cleanup_substitution(struct bsdtar *bsdtar)
312{
313	struct subst_rule *rule;
314	struct substitution *subst;
315
316	if ((subst = bsdtar->substitution) == NULL)
317		return;
318
319	while ((rule = subst->first_rule) != NULL) {
320		subst->first_rule = rule->next;
321		free(rule->result);
322		free(rule);
323	}
324	free(subst);
325}
326#endif /* defined(HAVE_REGEX_H) || defined(HAVE_PCREPOSIX_H) */
327