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.compression")) {
 283                 int level = git_config_int(var, value);
 284                 if (level == -1)
 285                         level = Z_DEFAULT_COMPRESSION;
 286                 else if (level < 0 || level > Z_BEST_COMPRESSION)
 287                         die("bad zlib compression level %d", level);
 288                 zlib_compression_level = level;
 289                 return 0;
 290         }
 291
 292         if (!strcmp(var, "user.name")) {
 293                 strlcpy(git_default_name, value, sizeof(git_default_name));
 294                 return 0;
 295         }
 296
 297         if (!strcmp(var, "user.email")) {
 298                 strlcpy(git_default_email, value, sizeof(git_default_email));
 299                 return 0;
 300         }
 301
 302         if (!strcmp(var, "i18n.commitencoding")) {
 303                 strlcpy(git_commit_encoding, value, sizeof(git_commit_encoding));
 304                 return 0;
 305         }
 306
 307         /* Add other config variables here and to Documentation/config.txt. */
 308         return 0;
 309 }
 310
 311 int git_config_from_file(config_fn_t fn, const char *filename)
 312 {
 313         int ret;
 314         FILE *f = fopen(filename, "r");
 315
 316         ret = -1;
 317         if (f) {
 318                 config_file = f;
 319                 config_file_name = filename;
 320                 config_linenr = 1;
 321                 ret = git_parse_file(fn);
 322                 fclose(f);
 323                 config_file_name = NULL;
 324         }
 325         return ret;
 326 }
 327
 328 int git_config(config_fn_t fn)
 329 {
 330         int ret = 0;
 331         char *repo_config = NULL;
 332         const char *home = NULL, *filename;
 333
 334         /* $GIT_CONFIG makes git read _only_ the given config file,
 335          * $GIT_CONFIG_LOCAL will make it process it in addition to the
 336          * global config file, the same way it would the per-repository
 337          * config file otherwise. */
 338         filename = getenv("GIT_CONFIG");
 339         if (!filename) {
 340                 home = getenv("HOME");
 341                 filename = getenv("GIT_CONFIG_LOCAL");
 342                 if (!filename)
 343                         filename = repo_config = strdup(git_path("config"));
 344         }
 345
 346         if (home) {
 347                 char *user_config = strdup(mkpath("%s/.gitconfig", home));
 348                 if (!access(user_config, R_OK))
 349                         ret = git_config_from_file(fn, user_config);
 350                 free(user_config);
 351         }
 352
 353         ret += git_config_from_file(fn, filename);
 354         if (repo_config)
 355                 free(repo_config);
 356         return ret;
 357 }
 358
 359 /*
 360  * Find all the stuff for git_config_set() below.
 361  */
 362
 363 #define MAX_MATCHES 512
 364
 365 static struct {
 366         int baselen;
 367         char* key;
 368         int do_not_match;
 369         regex_t* value_regex;
 370         int multi_replace;
 371         off_t offset[MAX_MATCHES];
 372         enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
 373         int seen;
 374 } store;
 375
 376 static int matches(const char* key, const char* value)
 377 {
 378         return !strcmp(key, store.key) &&
 379                 (store.value_regex == NULL ||
 380                  (store.do_not_match ^
 381                   !regexec(store.value_regex, value, 0, NULL, 0)));
 382 }
 383
 384 static int store_aux(const char* key, const char* value)
 385 {
 386         switch (store.state) {
 387         case KEY_SEEN:
 388                 if (matches(key, value)) {
 389                         if (store.seen == 1 && store.multi_replace == 0) {
 390                                 fprintf(stderr,
 391                                         "Warning: %s has multiple values\n",
 392                                         key);
 393                         } else if (store.seen >= MAX_MATCHES) {
 394                                 fprintf(stderr, "Too many matches\n");
 395                                 return 1;
 396                         }
 397
 398                         store.offset[store.seen] = ftell(config_file);
 399                         store.seen++;
 400                 }
 401                 break;
 402         case SECTION_SEEN:
 403                 if (strncmp(key, store.key, store.baselen+1)) {
 404                         store.state = SECTION_END_SEEN;
 405                         break;
 406                 } else
 407                         /* do not increment matches: this is no match */
 408                         store.offset[store.seen] = ftell(config_file);
 409                 /* fallthru */
 410         case SECTION_END_SEEN:
 411         case START:
 412                 if (matches(key, value)) {
 413                         store.offset[store.seen] = ftell(config_file);
 414                         store.state = KEY_SEEN;
 415                         store.seen++;
 416                 } else {
 417                         if (strrchr(key, '.') - key == store.baselen &&
 418                               !strncmp(key, store.key, store.baselen)) {
 419                                         store.state = SECTION_SEEN;
 420                                         store.offset[store.seen] = ftell(config_file);
 421                         }
 422                 }
 423         }
 424         return 0;
 425 }
 426
 427 static void store_write_section(int fd, const char* key)
 428 {
 429         const char *dot = strchr(key, '.');
 430         int len1 = store.baselen, len2 = -1;
 431
 432         dot = strchr(key, '.');
 433         if (dot) {
 434                 int dotlen = dot - key;
 435                 if (dotlen < len1) {
 436                         len2 = len1 - dotlen - 1;
 437                         len1 = dotlen;
 438                 }
 439         }
 440
 441         write(fd, "[", 1);
 442         write(fd, key, len1);
 443         if (len2 >= 0) {
 444                 write(fd, " \"", 2);
 445                 while (--len2 >= 0) {
 446                         unsigned char c = *++dot;
 447                         if (c == '"')
 448                                 write(fd, "\\", 1);
 449                         write(fd, &c, 1);
 450                 }
 451                 write(fd, "\"", 1);
 452         }
 453         write(fd, "]\n", 2);
 454 }
 455
 456 static void store_write_pair(int fd, const char* key, const char* value)
 457 {
 458         int i;
 459
 460         write(fd, "\t", 1);
 461         write(fd, key+store.baselen+1,
 462                 strlen(key+store.baselen+1));
 463         write(fd, " = ", 3);
 464         for (i = 0; value[i]; i++)
 465                 switch (value[i]) {
 466                 case '\n': write(fd, "\\n", 2); break;
 467                 case '\t': write(fd, "\\t", 2); break;
 468                 case '"': case '\\': write(fd, "\\", 1);
 469                 default: write(fd, value+i, 1);
 470         }
 471         write(fd, "\n", 1);
 472 }
 473
 474 static int find_beginning_of_line(const char* contents, int size,
 475         int offset_, int* found_bracket)
 476 {
 477         int equal_offset = size, bracket_offset = size;
 478         int offset;
 479
 480         for (offset = offset_-2; offset > 0
 481                         && contents[offset] != '\n'; offset--)
 482                 switch (contents[offset]) {
 483                         case '=': equal_offset = offset; break;
 484                         case ']': bracket_offset = offset; break;
 485                 }
 486         if (bracket_offset < equal_offset) {
 487                 *found_bracket = 1;
 488                 offset = bracket_offset+1;
 489         } else
 490                 offset++;
 491
 492         return offset;
 493 }
 494
 495 int git_config_set(const char* key, const char* value)
 496 {
 497         return git_config_set_multivar(key, value, NULL, 0);
 498 }
 499
 500 /*
 501  * If value==NULL, unset in (remove from) config,
 502  * if value_regex!=NULL, disregard key/value pairs where value does not match.
 503  * if multi_replace==0, nothing, or only one matching key/value is replaced,
 504  *     else all matching key/values (regardless how many) are removed,
 505  *     before the new pair is written.
 506  *
 507  * Returns 0 on success.
 508  *
 509  * This function does this:
 510  *
 511  * - it locks the config file by creating ".git/config.lock"
 512  *
 513  * - it then parses the config using store_aux() as validator to find
 514  *   the position on the key/value pair to replace. If it is to be unset,
 515  *   it must be found exactly once.
 516  *
 517  * - the config file is mmap()ed and the part before the match (if any) is
 518  *   written to the lock file, then the changed part and the rest.
 519  *
 520  * - the config file is removed and the lock file rename()d to it.
 521  *
 522  */
 523 int git_config_set_multivar(const char* key, const char* value,
 524         const char* value_regex, int multi_replace)
 525 {
 526         int i, dot;
 527         int fd = -1, in_fd;
 528         int ret;
 529         char* config_filename;
 530         char* lock_file;
 531         const char* last_dot = strrchr(key, '.');
 532
 533         config_filename = getenv("GIT_CONFIG");
 534         if (!config_filename) {
 535                 config_filename = getenv("GIT_CONFIG_LOCAL");
 536                 if (!config_filename)
 537                         config_filename  = git_path("config");
 538         }
 539         config_filename = strdup(config_filename);
 540         lock_file = strdup(mkpath("%s.lock", config_filename));
 541
 542         /*
 543          * Since "key" actually contains the section name and the real
 544          * key name separated by a dot, we have to know where the dot is.
 545          */
 546
 547         if (last_dot == NULL) {
 548                 fprintf(stderr, "key does not contain a section: %s\n", key);
 549                 ret = 2;
 550                 goto out_free;
 551         }
 552         store.baselen = last_dot - key;
 553
 554         store.multi_replace = multi_replace;
 555
 556         /*
 557          * Validate the key and while at it, lower case it for matching.
 558          */
 559         store.key = (char*)malloc(strlen(key)+1);
 560         dot = 0;
 561         for (i = 0; key[i]; i++) {
 562                 unsigned char c = key[i];
 563                 if (c == '.')
 564                         dot = 1;
 565                 /* Leave the extended basename untouched.. */
 566                 if (!dot || i > store.baselen) {
 567                         if (!isalnum(c) || (i == store.baselen+1 && !isalpha(c))) {
 568                                 fprintf(stderr, "invalid key: %s\n", key);
 569                                 free(store.key);
 570                                 ret = 1;
 571                                 goto out_free;
 572                         }
 573                         c = tolower(c);
 574                 }
 575                 store.key[i] = c;
 576         }
 577         store.key[i] = 0;
 578
 579         /*
 580          * The lock_file serves a purpose in addition to locking: the new
 581          * contents of .git/config will be written into it.
 582          */
 583         fd = open(lock_file, O_WRONLY | O_CREAT | O_EXCL, 0666);
 584         if (fd < 0 || adjust_shared_perm(lock_file)) {
 585                 fprintf(stderr, "could not lock config file\n");
 586                 free(store.key);
 587                 ret = -1;
 588                 goto out_free;
 589         }
 590
 591         /*
 592          * If .git/config does not exist yet, write a minimal version.
 593          */
 594         in_fd = open(config_filename, O_RDONLY);
 595         if ( in_fd < 0 ) {
 596                 free(store.key);
 597
 598                 if ( ENOENT != errno ) {
 599                         error("opening %s: %s", config_filename,
 600                               strerror(errno));
 601                         ret = 3; /* same as "invalid config file" */
 602                         goto out_free;
 603                 }
 604                 /* if nothing to unset, error out */
 605                 if (value == NULL) {
 606                         ret = 5;
 607                         goto out_free;
 608                 }
 609
 610                 store.key = (char*)key;
 611                 store_write_section(fd, key);
 612                 store_write_pair(fd, key, value);
 613         } else{
 614                 struct stat st;
 615                 char* contents;
 616                 int i, copy_begin, copy_end, new_line = 0;
 617
 618                 if (value_regex == NULL)
 619                         store.value_regex = NULL;
 620                 else {
 621                         if (value_regex[0] == '!') {
 622                                 store.do_not_match = 1;
 623                                 value_regex++;
 624                         } else
 625                                 store.do_not_match = 0;
 626
 627                         store.value_regex = (regex_t*)malloc(sizeof(regex_t));
 628                         if (regcomp(store.value_regex, value_regex,
 629                                         REG_EXTENDED)) {
 630                                 fprintf(stderr, "Invalid pattern: %s\n",
 631                                         value_regex);
 632                                 free(store.value_regex);
 633                                 ret = 6;
 634                                 goto out_free;
 635                         }
 636                 }
 637
 638                 store.offset[0] = 0;
 639                 store.state = START;
 640                 store.seen = 0;
 641
 642                 /*
 643                  * After this, store.offset will contain the *end* offset
 644                  * of the last match, or remain at 0 if no match was found.
 645                  * As a side effect, we make sure to transform only a valid
 646                  * existing config file.
 647                  */
 648                 if (git_config_from_file(store_aux, config_filename)) {
 649                         fprintf(stderr, "invalid config file\n");
 650                         free(store.key);
 651                         if (store.value_regex != NULL) {
 652                                 regfree(store.value_regex);
 653                                 free(store.value_regex);
 654                         }
 655                         ret = 3;
 656                         goto out_free;
 657                 }
 658
 659                 free(store.key);
 660                 if (store.value_regex != NULL) {
 661                         regfree(store.value_regex);
 662                         free(store.value_regex);
 663                 }
 664
 665                 /* if nothing to unset, or too many matches, error out */
 666                 if ((store.seen == 0 && value == NULL) ||
 667                                 (store.seen > 1 && multi_replace == 0)) {
 668                         ret = 5;
 669                         goto out_free;
 670                 }
 671
 672                 fstat(in_fd, &st);
 673                 contents = mmap(NULL, st.st_size, PROT_READ,
 674                         MAP_PRIVATE, in_fd, 0);
 675                 close(in_fd);
 676
 677                 if (store.seen == 0)
 678                         store.seen = 1;
 679
 680                 for (i = 0, copy_begin = 0; i < store.seen; i++) {
 681                         if (store.offset[i] == 0) {
 682                                 store.offset[i] = copy_end = st.st_size;
 683                         } else if (store.state != KEY_SEEN) {
 684                                 copy_end = store.offset[i];
 685                         } else
 686                                 copy_end = find_beginning_of_line(
 687                                         contents, st.st_size,
 688                                         store.offset[i]-2, &new_line);
 689
 690                         /* write the first part of the config */
 691                         if (copy_end > copy_begin) {
 692                                 write(fd, contents + copy_begin,
 693                                 copy_end - copy_begin);
 694                                 if (new_line)
 695                                         write(fd, "\n", 1);
 696                         }
 697                         copy_begin = store.offset[i];
 698                 }
 699
 700                 /* write the pair (value == NULL means unset) */
 701                 if (value != NULL) {
 702                         if (store.state == START)
 703                                 store_write_section(fd, key);
 704                         store_write_pair(fd, key, value);
 705                 }
 706
 707                 /* write the rest of the config */
 708                 if (copy_begin < st.st_size)
 709                         write(fd, contents + copy_begin,
 710                                 st.st_size - copy_begin);
 711
 712                 munmap(contents, st.st_size);
 713                 unlink(config_filename);
 714         }
 715
 716         if (rename(lock_file, config_filename) < 0) {
 717                 fprintf(stderr, "Could not rename the lock file?\n");
 718                 ret = 4;
 719                 goto out_free;
 720         }
 721
 722         ret = 0;
 723
 724 out_free:
 725         if (0 <= fd)
 726                 close(fd);
 727         if (config_filename)
 728                 free(config_filename);
 729         if (lock_file) {
 730                 unlink(lock_file);
 731                 free(lock_file);
 732         }
 733         return ret;
 734 }
 735
 736