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: src/usr.bin/tar/subst.c,v 1.4 2008/06/15 10:08:16 kientzle Exp $");
  28
  29 #if HAVE_REGEX_H
  30 #include "bsdtar.h"
  31
  32 #include <errno.h>
  33 #include <regex.h>
  34 #include <stdlib.h>
  35 #include <string.h>
  36
  37 #ifndef REG_BASIC
  38 #define REG_BASIC 0
  39 #endif
  40
  41 #include "err.h"
  42
  43 struct subst_rule {
  44         struct subst_rule *next;
  45         regex_t re;
  46         char *result;
  47         unsigned int global:1, print:1, regular:1, symlink:1, hardlink:1;
  48 };
  49
  50 struct substitution {
  51         struct subst_rule *first_rule, *last_rule;
  52 };
  53
  54 static void
  55 init_substitution(struct bsdtar *bsdtar)
  56 {
  57         struct substitution *subst;
  58
  59         bsdtar->substitution = subst = malloc(sizeof(*subst));
  60         if (subst == NULL)
  61                 lafe_errc(1, errno, "Out of memory");
  62         subst->first_rule = subst->last_rule = NULL;
  63 }
  64
  65 void
  66 add_substitution(struct bsdtar *bsdtar, const char *rule_text)
  67 {
  68         struct subst_rule *rule;
  69         struct substitution *subst;
  70         const char *end_pattern, *start_subst;
  71         char *pattern;
  72         int r;
  73
  74         if ((subst = bsdtar->substitution) == NULL) {
  75                 init_substitution(bsdtar);
  76                 subst = bsdtar->substitution;
  77         }
  78
  79         rule = malloc(sizeof(*rule));
  80         if (rule == NULL)
  81                 lafe_errc(1, errno, "Out of memory");
  82         rule->next = NULL;
  83
  84         if (subst->last_rule == NULL)
  85                 subst->first_rule = rule;
  86         else
  87                 subst->last_rule->next = rule;
  88         subst->last_rule = rule;
  89
  90         if (*rule_text == '\0')
  91                 lafe_errc(1, 0, "Empty replacement string");
  92         end_pattern = strchr(rule_text + 1, *rule_text);
  93         if (end_pattern == NULL)
  94                 lafe_errc(1, 0, "Invalid replacement string");
  95
  96         pattern = malloc(end_pattern - rule_text);
  97         if (pattern == NULL)
  98                 lafe_errc(1, errno, "Out of memory");
  99         memcpy(pattern, rule_text + 1, end_pattern - rule_text - 1);
 100         pattern[end_pattern - rule_text - 1] = '\0';
 101
 102         if ((r = regcomp(&rule->re, pattern, REG_BASIC)) != 0) {
 103                 char buf[80];
 104                 regerror(r, &rule->re, buf, sizeof(buf));
 105                 lafe_errc(1, 0, "Invalid regular expression: %s", buf);
 106         }
 107         free(pattern);
 108
 109         start_subst = end_pattern + 1;
 110         end_pattern = strchr(start_subst, *rule_text);
 111         if (end_pattern == NULL)
 112                 lafe_errc(1, 0, "Invalid replacement string");
 113
 114         rule->result = malloc(end_pattern - start_subst + 1);
 115         if (rule->result == NULL)
 116                 lafe_errc(1, errno, "Out of memory");
 117         memcpy(rule->result, start_subst, end_pattern - start_subst);
 118         rule->result[end_pattern - start_subst] = '\0';
 119
 120         /* Defaults */
 121         rule->global = 0; /* Don't do multiple replacements. */
 122         rule->print = 0; /* Don't print. */
 123         rule->regular = 1; /* Rewrite regular filenames. */
 124         rule->symlink = 1; /* Rewrite symlink targets. */
 125         rule->hardlink = 1; /* Rewrite hardlink targets. */
 126
 127         while (*++end_pattern) {
 128                 switch (*end_pattern) {
 129                 case 'g':
 130                 case 'G':
 131                         rule->global = 1;
 132                         break;
 133                 case 'h':
 134                         rule->hardlink = 1;
 135                         break;
 136                 case 'H':
 137                         rule->hardlink = 0;
 138                         break;
 139                 case 'p':
 140                 case 'P':
 141                         rule->print = 1;
 142                         break;
 143                 case 'r':
 144                         rule->regular = 1;
 145                         break;
 146                 case 'R':
 147                         rule->regular = 0;
 148                         break;
 149                 case 's':
 150                         rule->symlink = 1;
 151                         break;
 152                 case 'S':
 153                         rule->symlink = 0;
 154                         break;
 155                 default:
 156                         lafe_errc(1, 0, "Invalid replacement flag %c", *end_pattern);
 157                 }
 158         }
 159 }
 160
 161 static void
 162 realloc_strncat(char **str, const char *append, size_t len)
 163 {
 164         char *new_str;
 165         size_t old_len;
 166
 167         if (*str == NULL)
 168                 old_len = 0;
 169         else
 170                 old_len = strlen(*str);
 171
 172         new_str = malloc(old_len + len + 1);
 173         if (new_str == NULL)
 174                 lafe_errc(1, errno, "Out of memory");
 175         if (*str != NULL)
 176                 memcpy(new_str, *str, old_len);
 177         memcpy(new_str + old_len, append, len);
 178         new_str[old_len + len] = '\0';
 179         free(*str);
 180         *str = new_str;
 181 }
 182
 183 static void
 184 realloc_strcat(char **str, const char *append)
 185 {
 186         char *new_str;
 187         size_t old_len;
 188
 189         if (*str == NULL)
 190                 old_len = 0;
 191         else
 192                 old_len = strlen(*str);
 193
 194         new_str = malloc(old_len + strlen(append) + 1);
 195         if (new_str == NULL)
 196                 lafe_errc(1, errno, "Out of memory");
 197         if (*str != NULL)
 198                 memcpy(new_str, *str, old_len);
 199         strcpy(new_str + old_len, append);
 200         free(*str);
 201         *str = new_str;
 202 }
 203
 204 int
 205 apply_substitution(struct bsdtar *bsdtar, const char *name, char **result,
 206     int symlink_target, int hardlink_target)
 207 {
 208         const char *path = name;
 209         regmatch_t matches[10];
 210         size_t i, j;
 211         struct subst_rule *rule;
 212         struct substitution *subst;
 213         int c, got_match, print_match;
 214
 215         *result = NULL;
 216
 217         if ((subst = bsdtar->substitution) == NULL)
 218                 return 0;
 219
 220         got_match = 0;
 221         print_match = 0;
 222
 223         for (rule = subst->first_rule; rule != NULL; rule = rule->next) {
 224                 if (symlink_target) {
 225                         if (!rule->symlink)
 226                                 continue;
 227                 } else if (hardlink_target) {
 228                         if (!rule->hardlink)
 229                                 continue;
 230                 } else { /* Regular filename. */
 231                         if (!rule->regular)
 232                                 continue;
 233                 }
 234
 235                 if (regexec(&rule->re, name, 10, matches, 0))
 236                         continue;
 237
 238                 got_match = 1;
 239                 print_match |= rule->print;
 240                 realloc_strncat(result, name, matches[0].rm_so);
 241
 242                 for (i = 0, j = 0; rule->result[i] != '\0'; ++i) {
 243                         if (rule->result[i] == '~') {
 244                                 realloc_strncat(result, rule->result + j, i - j);
 245                                 realloc_strncat(result,
 246                                     name + matches[0].rm_so,
 247                                     matches[0].rm_eo - matches[0].rm_so);
 248                                 j = i + 1;
 249                                 continue;
 250                         }
 251                         if (rule->result[i] != '\\')
 252                                 continue;
 253
 254                         ++i;
 255                         c = rule->result[i];
 256                         switch (c) {
 257                         case '~':
 258                         case '\\':
 259                                 realloc_strncat(result, rule->result + j, i - j - 1);
 260                                 j = i;
 261                                 break;
 262                         case '1':
 263                         case '2':
 264                         case '3':
 265                         case '4':
 266                         case '5':
 267                         case '6':
 268                         case '7':
 269                         case '8':
 270                         case '9':
 271                                 realloc_strncat(result, rule->result + j, i - j - 1);
 272                                 if ((size_t)(c - '0') > (size_t)(rule->re.re_nsub)) {
 273                                         free(*result);
 274                                         *result = NULL;
 275                                         return -1;
 276                                 }
 277                                 realloc_strncat(result, name + matches[c - '0'].rm_so, matches[c - '0'].rm_eo - matches[c - '0'].rm_so);
 278                                 j = i + 1;
 279                                 break;
 280                         default:
 281                                 /* Just continue; */
 282                                 break;
 283                         }
 284
 285                 }
 286
 287                 realloc_strcat(result, rule->result + j);
 288
 289                 name += matches[0].rm_eo;
 290
 291                 if (!rule->global)
 292                         break;
 293         }
 294
 295         if (got_match)
 296                 realloc_strcat(result, name);
 297
 298         if (print_match)
 299                 fprintf(stderr, "%s >> %s\n", path, *result);
 300
 301         return got_match;
 302 }
 303
 304 void
 305 cleanup_substitution(struct bsdtar *bsdtar)
 306 {
 307         struct subst_rule *rule;
 308         struct substitution *subst;
 309
 310         if ((subst = bsdtar->substitution) == NULL)
 311                 return;
 312
 313         while ((rule = subst->first_rule) != NULL) {
 314                 subst->first_rule = rule->next;
 315                 free(rule->result);
 316                 free(rule);
 317         }
 318         free(subst);
 319 }
 320 #endif /* HAVE_REGEX_H */