config.c

   1 /*
   2  * GIT - The information manager from hell
   3  *
   4  * Copyright (C) Linus Torvalds, 2005
   5  * Copyright (C) Johannes Schindelin, 2005
   6  *
   7  */
   8 #include "cache.h"
   9 #include <regex.h>
  10
  11 #define MAXNAME (256)
  12
  13 static FILE *config_file;
  14 static const char *config_file_name;
  15 static int config_linenr;
  16 static int get_next_char(void)
  17 {
  18         int c;
  19         FILE *f;
  20
  21         c = '\n';
  22         if ((f = config_file) != NULL) {
  23                 c = fgetc(f);
  24                 if (c == '\r') {
  25                         /* DOS like systems */
  26                         c = fgetc(f);
  27                         if (c != '\n') {
  28                                 ungetc(c, f);
  29                                 c = '\r';
  30                         }
  31                 }
  32                 if (c == '\n')
  33                         config_linenr++;
  34                 if (c == EOF) {
  35                         config_file = NULL;
  36                         c = '\n';
  37                 }
  38         }
  39         return c;
  40 }
  41
  42 static char *parse_value(void)
  43 {
  44         static char value[1024];
  45         int quote = 0, comment = 0, len = 0, space = 0;
  46
  47         for (;;) {
  48                 int c = get_next_char();
  49                 if (len >= sizeof(value))
  50                         return NULL;
  51                 if (c == '\n') {
  52                         if (quote)
  53                                 return NULL;
  54                         value[len] = 0;
  55                         return value;
  56                 }
  57                 if (comment)
  58                         continue;
  59                 if (isspace(c) && !quote) {
  60                         space = 1;
  61                         continue;
  62                 }
  63                 if (!quote) {
  64                         if (c == ';' || c == '#') {
  65                                 comment = 1;
  66                                 continue;
  67                         }
  68                 }
  69                 if (space) {
  70                         if (len)
  71                                 value[len++] = ' ';
  72                         space = 0;
  73                 }
  74                 if (c == '\\') {
  75                         c = get_next_char();
  76                         switch (c) {
  77                         case '\n':
  78                                 continue;
  79                         case 't':
  80                                 c = '\t';
  81                                 break;
  82                         case 'b':
  83                                 c = '\b';
  84                                 break;
  85                         case 'n':
  86                                 c = '\n';
  87                                 break;
  88                         /* Some characters escape as themselves */
  89                         case '\\': case '"':
  90                                 break;
  91                         /* Reject unknown escape sequences */
  92                         default:
  93                                 return NULL;
  94                         }
  95                         value[len++] = c;
  96                         continue;
  97                 }
  98                 if (c == '"') {
  99                         quote = 1-quote;
 100                         continue;
 101                 }
 102                 value[len++] = c;
 103         }
 104 }
 105
 106 static inline int iskeychar(int c)
 107 {
 108         return isalnum(c) || c == '-';
 109 }
 110
 111 static int get_value(config_fn_t fn, char *name, unsigned int len)
 112 {
 113         int c;
 114         char *value;
 115
 116         /* Get the full name */
 117         for (;;) {
 118                 c = get_next_char();
 119                 if (c == EOF)
 120                         break;
 121                 if (!iskeychar(c))
 122                         break;
 123                 name[len++] = tolower(c);
 124                 if (len >= MAXNAME)
 125                         return -1;
 126         }
 127         name[len] = 0;
 128         while (c == ' ' || c == '\t')
 129                 c = get_next_char();
 130
 131         value = NULL;
 132         if (c != '\n') {
 133                 if (c != '=')
 134                         return -1;
 135                 value = parse_value();
 136                 if (!value)
 137                         return -1;
 138         }
 139         return fn(name, value);
 140 }
 141
 142 static int get_extended_base_var(char *name, int baselen, int c)
 143 {
 144         do {
 145                 if (c == '\n')
 146                         return -1;
 147                 c = get_next_char();
 148         } while (isspace(c));
 149
 150         /* We require the format to be '[base "extension"]' */
 151         if (c != '"')
 152                 return -1;
 153         name[baselen++] = '.';
 154
 155         for (;;) {
 156                 int c = get_next_char();
 157                 if (c == '\n')
 158                         return -1;
 159                 if (c == '"')
 160                         break;
 161                 if (c == '\\') {
 162                         c = get_next_char();
 163                         if (c == '\n')
 164                                 return -1;
 165                 }
 166                 name[baselen++] = c;
 167                 if (baselen > MAXNAME / 2)
 168                         return -1;
 169         }
 170
 171         /* Final ']' */
 172         if (get_next_char() != ']')
 173                 return -1;
 174         return baselen;
 175 }
 176
 177 static int get_base_var(char *name)
 178 {
 179         int baselen = 0;
 180
 181         for (;;) {
 182                 int c = get_next_char();
 183                 if (c == EOF)
 184                         return -1;
 185                 if (c == ']')
 186                         return baselen;
 187                 if (isspace(c))
 188                         return get_extended_base_var(name, baselen, c);
 189                 if (!iskeychar(c) && c != '.')
 190                         return -1;
 191                 if (baselen > MAXNAME / 2)
 192                         return -1;
 193                 name[baselen++] = tolower(c);
 194         }
 195 }
 196
 197 static int git_parse_file(config_fn_t fn)
 198 {
 199         int comment = 0;
 200         int baselen = 0;
 201         static char var[MAXNAME];
 202
 203         for (;;) {
 204                 int c = get_next_char();
 205                 if (c == '\n') {
 206                         /* EOF? */
 207                         if (!config_file)
 208                                 return 0;
 209                         comment = 0;
 210                         continue;
 211                 }
 212                 if (comment || isspace(c))
 213                         continue;
 214                 if (c == '#' || c == ';') {
 215                         comment = 1;
 216                         continue;
 217                 }
 218                 if (c == '[') {
 219                         baselen = get_base_var(var);
 220                         if (baselen <= 0)
 221                                 break;
 222                         var[baselen++] = '.';
 223                         var[baselen] = 0;
 224                         continue;
 225                 }
 226                 if (!isalpha(c))
 227                         break;
 228                 var[baselen] = tolower(c);
 229                 if (get_value(fn, var, baselen+1) < 0)
 230                         break;
 231         }
 232         die("bad config file line %d in %s", config_linenr, config_file_name);
 233 }
 234
 235 int git_config_int(const char *name, const char *value)
 236 {
 237         if (value && *value) {
 238                 char *end;
 239                 int val = strtol(value, &end, 0);
 240                 if (!*end)
 241                         return val;
 242         }
 243         die("bad config value for '%s' in %s", name, config_file_name);
 244 }
 245
 246 int git_config_bool(const char *name, const char *value)
 247 {
 248         if (!value)
 249                 return 1;
 250         if (!*value)
 251                 return 0;
 252         if (!strcasecmp(value, "true") || !strcasecmp(value, "yes"))
 253                 return 1;
 254         if (!strcasecmp(value, "false") || !strcasecmp(value, "no"))
 255                 return 0;
 256         return git_config_int(name, value) != 0;
 257 }
 258
 259 int git_default_config(const char *var, const char *value)
 260 {
 261         /* This needs a better name */
 262         if (!strcmp(var, "core.filemode")) {
 263                 trust_executable_bit = git_config_bool(var, value);
 264                 return 0;
 265         }
 266
 267         if (!strcmp(var, "core.ignorestat")) {
 268                 assume_unchanged = git_config_bool(var, value);
 269                 return 0;
 270         }
 271
 272         if (!strcmp(var, "core.prefersymlinkrefs")) {
 273                 prefer_symlink_refs = git_config_bool(var, value);
 274                 return 0;
 275         }
 276
 277         if (!strcmp(var, "core.logallrefupdates")) {
 278                 log_all_ref_updates = git_config_bool(var, value);
 279                 return 0;
 280         }
 281
 282         if (!strcmp(var, "core.warnambiguousrefs")) {
 283                 warn_ambiguous_refs = git_config_bool(var, value);
 284                 return 0;
 285         }
 286
 287         if (!strcmp(var, "core.legacyheaders")) {
 288                 use_legacy_headers = git_config_bool(var, value);
 289                 return 0;
 290         }
 291
 292         if (!strcmp(var, "core.compression")) {
 293                 int level = git_config_int(var, value);
 294                 if (level == -1)
 295                         level = Z_DEFAULT_COMPRESSION;
 296                 else if (level < 0 || level > Z_BEST_COMPRESSION)
 297                         die("bad zlib compression level %d", level);
 298                 zlib_compression_level = level;
 299                 return 0;
 300         }
 301
 302         if (!strcmp(var, "user.name")) {
 303                 strlcpy(git_default_name, value, sizeof(git_default_name));
 304                 return 0;
 305         }
 306
 307         if (!strcmp(var, "user.email")) {
 308                 strlcpy(git_default_email, value, sizeof(git_default_email));
 309                 return 0;
 310         }
 311
 312         if (!strcmp(var, "i18n.commitencoding")) {
 313                 strlcpy(git_commit_encoding, value, sizeof(git_commit_encoding));
 314                 return 0;
 315         }
 316
 317         if (!strcmp(var, "pager.color")) {
 318                 pager_use_color = git_config_bool(var,value);
 319                 return 0;
 320         }
 321
 322         /* Add other config variables here and to Documentation/config.txt. */
 323         return 0;
 324 }
 325
 326 int git_config_from_file(config_fn_t fn, const char *filename)
 327 {
 328         int ret;
 329         FILE *f = fopen(filename, "r");
 330
 331         ret = -1;
 332         if (f) {
 333                 config_file = f;
 334                 config_file_name = filename;
 335                 config_linenr = 1;
 336                 ret = git_parse_file(fn);
 337                 fclose(f);
 338                 config_file_name = NULL;
 339         }
 340         return ret;
 341 }
 342
 343 int git_config(config_fn_t fn)
 344 {
 345         int ret = 0;
 346         char *repo_config = NULL;
 347         const char *home = NULL, *filename;
 348
 349         /* $GIT_CONFIG makes git read _only_ the given config file,
 350          * $GIT_CONFIG_LOCAL will make it process it in addition to the
 351          * global config file, the same way it would the per-repository
 352          * config file otherwise. */
 353         filename = getenv("GIT_CONFIG");
 354         if (!filename) {
 355                 home = getenv("HOME");
 356                 filename = getenv("GIT_CONFIG_LOCAL");
 357                 if (!filename)
 358                         filename = repo_config = xstrdup(git_path("config"));
 359         }
 360
 361         if (home) {
 362                 char *user_config = xstrdup(mkpath("%s/.gitconfig", home));
 363                 if (!access(user_config, R_OK))
 364                         ret = git_config_from_file(fn, user_config);
 365                 free(user_config);
 366         }
 367
 368         ret += git_config_from_file(fn, filename);
 369         free(repo_config);
 370         return ret;
 371 }
 372
 373 /*
 374  * Find all the stuff for git_config_set() below.
 375  */
 376
 377 #define MAX_MATCHES 512
 378
 379 static struct {
 380         int baselen;
 381         char* key;
 382         int do_not_match;
 383         regex_t* value_regex;
 384         int multi_replace;
 385         off_t offset[MAX_MATCHES];
 386         enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
 387         int seen;
 388 } store;
 389
 390 static int matches(const char* key, const char* value)
 391 {
 392         return !strcmp(key, store.key) &&
 393                 (store.value_regex == NULL ||
 394                  (store.do_not_match ^
 395                   !regexec(store.value_regex, value, 0, NULL, 0)));
 396 }
 397
 398 static int store_aux(const char* key, const char* value)
 399 {
 400         switch (store.state) {
 401         case KEY_SEEN:
 402                 if (matches(key, value)) {
 403                         if (store.seen == 1 && store.multi_replace == 0) {
 404                                 fprintf(stderr,
 405                                         "Warning: %s has multiple values\n",
 406                                         key);
 407                         } else if (store.seen >= MAX_MATCHES) {
 408                                 fprintf(stderr, "Too many matches\n");
 409                                 return 1;
 410                         }
 411
 412                         store.offset[store.seen] = ftell(config_file);
 413                         store.seen++;
 414                 }
 415                 break;
 416         case SECTION_SEEN:
 417                 if (strncmp(key, store.key, store.baselen+1)) {
 418                         store.state = SECTION_END_SEEN;
 419                         break;
 420                 } else
 421                         /* do not increment matches: this is no match */
 422                         store.offset[store.seen] = ftell(config_file);
 423                 /* fallthru */
 424         case SECTION_END_SEEN:
 425         case START:
 426                 if (matches(key, value)) {
 427                         store.offset[store.seen] = ftell(config_file);
 428                         store.state = KEY_SEEN;
 429                         store.seen++;
 430                 } else {
 431                         if (strrchr(key, '.') - key == store.baselen &&
 432                               !strncmp(key, store.key, store.baselen)) {
 433                                         store.state = SECTION_SEEN;
 434                                         store.offset[store.seen] = ftell(config_file);
 435                         }
 436                 }
 437         }
 438         return 0;
 439 }
 440
 441 static void store_write_section(int fd, const char* key)
 442 {
 443         const char *dot = strchr(key, '.');
 444         int len1 = store.baselen, len2 = -1;
 445
 446         dot = strchr(key, '.');
 447         if (dot) {
 448                 int dotlen = dot - key;
 449                 if (dotlen < len1) {
 450                         len2 = len1 - dotlen - 1;
 451                         len1 = dotlen;
 452                 }
 453         }
 454
 455         write(fd, "[", 1);
 456         write(fd, key, len1);
 457         if (len2 >= 0) {
 458                 write(fd, " \"", 2);
 459                 while (--len2 >= 0) {
 460                         unsigned char c = *++dot;
 461                         if (c == '"')
 462                                 write(fd, "\\", 1);
 463                         write(fd, &c, 1);
 464                 }
 465                 write(fd, "\"", 1);
 466         }
 467         write(fd, "]\n", 2);
 468 }
 469
 470 static void store_write_pair(int fd, const char* key, const char* value)
 471 {
 472         int i;
 473
 474         write(fd, "\t", 1);
 475         write(fd, key+store.baselen+1,
 476                 strlen(key+store.baselen+1));
 477         write(fd, " = ", 3);
 478         for (i = 0; value[i]; i++)
 479                 switch (value[i]) {
 480                 case '\n': write(fd, "\\n", 2); break;
 481                 case '\t': write(fd, "\\t", 2); break;
 482                 case '"': case '\\': write(fd, "\\", 1);
 483                 default: write(fd, value+i, 1);
 484         }
 485         write(fd, "\n", 1);
 486 }
 487
 488 static int find_beginning_of_line(const char* contents, int size,
 489         int offset_, int* found_bracket)
 490 {
 491         int equal_offset = size, bracket_offset = size;
 492         int offset;
 493
 494         for (offset = offset_-2; offset > 0
 495                         && contents[offset] != '\n'; offset--)
 496                 switch (contents[offset]) {
 497                         case '=': equal_offset = offset; break;
 498                         case ']': bracket_offset = offset; break;
 499                 }
 500         if (bracket_offset < equal_offset) {
 501                 *found_bracket = 1;
 502                 offset = bracket_offset+1;
 503         } else
 504                 offset++;
 505
 506         return offset;
 507 }
 508
 509 int git_config_set(const char* key, const char* value)
 510 {
 511         return git_config_set_multivar(key, value, NULL, 0);
 512 }
 513
 514 /*
 515  * If value==NULL, unset in (remove from) config,
 516  * if value_regex!=NULL, disregard key/value pairs where value does not match.
 517  * if multi_replace==0, nothing, or only one matching key/value is replaced,
 518  *     else all matching key/values (regardless how many) are removed,
 519  *     before the new pair is written.
 520  *
 521  * Returns 0 on success.
 522  *
 523  * This function does this:
 524  *
 525  * - it locks the config file by creating ".git/config.lock"
 526  *
 527  * - it then parses the config using store_aux() as validator to find
 528  *   the position on the key/value pair to replace. If it is to be unset,
 529  *   it must be found exactly once.
 530  *
 531  * - the config file is mmap()ed and the part before the match (if any) is
 532  *   written to the lock file, then the changed part and the rest.
 533  *
 534  * - the config file is removed and the lock file rename()d to it.
 535  *
 536  */
 537 int git_config_set_multivar(const char* key, const char* value,
 538         const char* value_regex, int multi_replace)
 539 {
 540         int i, dot;
 541         int fd = -1, in_fd;
 542         int ret;
 543         char* config_filename;
 544         char* lock_file;
 545         const char* last_dot = strrchr(key, '.');
 546
 547         config_filename = getenv("GIT_CONFIG");
 548         if (!config_filename) {
 549                 config_filename = getenv("GIT_CONFIG_LOCAL");
 550                 if (!config_filename)
 551                         config_filename  = git_path("config");
 552         }
 553         config_filename = xstrdup(config_filename);
 554         lock_file = xstrdup(mkpath("%s.lock", config_filename));
 555
 556         /*
 557          * Since "key" actually contains the section name and the real
 558          * key name separated by a dot, we have to know where the dot is.
 559          */
 560
 561         if (last_dot == NULL) {
 562                 fprintf(stderr, "key does not contain a section: %s\n", key);
 563                 ret = 2;
 564                 goto out_free;
 565         }
 566         store.baselen = last_dot - key;
 567
 568         store.multi_replace = multi_replace;
 569
 570         /*
 571          * Validate the key and while at it, lower case it for matching.
 572          */
 573         store.key = xmalloc(strlen(key) + 1);
 574         dot = 0;
 575         for (i = 0; key[i]; i++) {
 576                 unsigned char c = key[i];
 577                 if (c == '.')
 578                         dot = 1;
 579                 /* Leave the extended basename untouched.. */
 580                 if (!dot || i > store.baselen) {
 581                         if (!iskeychar(c) || (i == store.baselen+1 && !isalpha(c))) {
 582                                 fprintf(stderr, "invalid key: %s\n", key);
 583                                 free(store.key);
 584                                 ret = 1;
 585                                 goto out_free;
 586                         }
 587                         c = tolower(c);
 588                 }
 589                 store.key[i] = c;
 590         }
 591         store.key[i] = 0;
 592
 593         /*
 594          * The lock_file serves a purpose in addition to locking: the new
 595          * contents of .git/config will be written into it.
 596          */
 597         fd = open(lock_file, O_WRONLY | O_CREAT | O_EXCL, 0666);
 598         if (fd < 0 || adjust_shared_perm(lock_file)) {
 599                 fprintf(stderr, "could not lock config file\n");
 600                 free(store.key);
 601                 ret = -1;
 602                 goto out_free;
 603         }
 604
 605         /*
 606          * If .git/config does not exist yet, write a minimal version.
 607          */
 608         in_fd = open(config_filename, O_RDONLY);
 609         if ( in_fd < 0 ) {
 610                 free(store.key);
 611
 612                 if ( ENOENT != errno ) {
 613                         error("opening %s: %s", config_filename,
 614                               strerror(errno));
 615                         ret = 3; /* same as "invalid config file" */
 616                         goto out_free;
 617                 }
 618                 /* if nothing to unset, error out */
 619                 if (value == NULL) {
 620                         ret = 5;
 621                         goto out_free;
 622                 }
 623
 624                 store.key = (char*)key;
 625                 store_write_section(fd, key);
 626                 store_write_pair(fd, key, value);
 627         } else{
 628                 struct stat st;
 629                 char* contents;
 630                 int i, copy_begin, copy_end, new_line = 0;
 631
 632                 if (value_regex == NULL)
 633                         store.value_regex = NULL;
 634                 else {
 635                         if (value_regex[0] == '!') {
 636                                 store.do_not_match = 1;
 637                                 value_regex++;
 638                         } else
 639                                 store.do_not_match = 0;
 640
 641                         store.value_regex = (regex_t*)xmalloc(sizeof(regex_t));
 642                         if (regcomp(store.value_regex, value_regex,
 643                                         REG_EXTENDED)) {
 644                                 fprintf(stderr, "Invalid pattern: %s\n",
 645                                         value_regex);
 646                                 free(store.value_regex);
 647                                 ret = 6;
 648                                 goto out_free;
 649                         }
 650                 }
 651
 652                 store.offset[0] = 0;
 653                 store.state = START;
 654                 store.seen = 0;
 655
 656                 /*
 657                  * After this, store.offset will contain the *end* offset
 658                  * of the last match, or remain at 0 if no match was found.
 659                  * As a side effect, we make sure to transform only a valid
 660                  * existing config file.
 661                  */
 662                 if (git_config_from_file(store_aux, config_filename)) {
 663                         fprintf(stderr, "invalid config file\n");
 664                         free(store.key);
 665                         if (store.value_regex != NULL) {
 666                                 regfree(store.value_regex);
 667                                 free(store.value_regex);
 668                         }
 669                         ret = 3;
 670                         goto out_free;
 671                 }
 672
 673                 free(store.key);
 674                 if (store.value_regex != NULL) {
 675                         regfree(store.value_regex);
 676                         free(store.value_regex);
 677                 }
 678
 679                 /* if nothing to unset, or too many matches, error out */
 680                 if ((store.seen == 0 && value == NULL) ||
 681                                 (store.seen > 1 && multi_replace == 0)) {
 682                         ret = 5;
 683                         goto out_free;
 684                 }
 685
 686                 fstat(in_fd, &st);
 687                 contents = mmap(NULL, st.st_size, PROT_READ,
 688                         MAP_PRIVATE, in_fd, 0);
 689                 close(in_fd);
 690
 691                 if (store.seen == 0)
 692                         store.seen = 1;
 693
 694                 for (i = 0, copy_begin = 0; i < store.seen; i++) {
 695                         if (store.offset[i] == 0) {
 696                                 store.offset[i] = copy_end = st.st_size;
 697                         } else if (store.state != KEY_SEEN) {
 698                                 copy_end = store.offset[i];
 699                         } else
 700                                 copy_end = find_beginning_of_line(
 701                                         contents, st.st_size,
 702                                         store.offset[i]-2, &new_line);
 703
 704                         /* write the first part of the config */
 705                         if (copy_end > copy_begin) {
 706                                 write(fd, contents + copy_begin,
 707                                 copy_end - copy_begin);
 708                                 if (new_line)
 709                                         write(fd, "\n", 1);
 710                         }
 711                         copy_begin = store.offset[i];
 712                 }
 713
 714                 /* write the pair (value == NULL means unset) */
 715                 if (value != NULL) {
 716                         if (store.state == START)
 717                                 store_write_section(fd, key);
 718                         store_write_pair(fd, key, value);
 719                 }
 720
 721                 /* write the rest of the config */
 722                 if (copy_begin < st.st_size)
 723                         write(fd, contents + copy_begin,
 724                                 st.st_size - copy_begin);
 725
 726                 munmap(contents, st.st_size);
 727                 unlink(config_filename);
 728         }
 729
 730         if (rename(lock_file, config_filename) < 0) {
 731                 fprintf(stderr, "Could not rename the lock file?\n");
 732                 ret = 4;
 733                 goto out_free;
 734         }
 735
 736         ret = 0;
 737
 738 out_free:
 739         if (0 <= fd)
 740                 close(fd);
 741         free(config_filename);
 742         if (lock_file) {
 743                 unlink(lock_file);
 744                 free(lock_file);
 745         }
 746         return ret;
 747 }
 748
 749