contrib/libarchive/tar/subst.c

   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("$FreeBSD$");
  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
  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
  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
  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
 165 static void
 166 realloc_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
 187 static void
 188 realloc_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
 208 int
 209 apply_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
 310 void
 311 cleanup_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) */