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