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