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         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
 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
 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
 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
 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) */