builtin-receive-pack.c

   1 #include "cache.h"
   2 #include "pack.h"
   3 #include "refs.h"
   4 #include "pkt-line.h"
   5 #include "run-command.h"
   6 #include "exec_cmd.h"
   7 #include "commit.h"
   8 #include "object.h"
   9 #include "remote.h"
  10 #include "transport.h"
  11
  12 static const char receive_pack_usage[] = "git receive-pack <git-dir>";
  13
  14 enum deny_action {
  15         DENY_UNCONFIGURED,
  16         DENY_IGNORE,
  17         DENY_WARN,
  18         DENY_REFUSE,
  19 };
  20
  21 static int deny_deletes;
  22 static int deny_non_fast_forwards;
  23 static enum deny_action deny_current_branch = DENY_UNCONFIGURED;
  24 static enum deny_action deny_delete_current = DENY_UNCONFIGURED;
  25 static int receive_fsck_objects;
  26 static int receive_unpack_limit = -1;
  27 static int transfer_unpack_limit = -1;
  28 static int unpack_limit = 100;
  29 static int report_status;
  30 static int prefer_ofs_delta = 1;
  31 static int auto_update_server_info;
  32 static int auto_gc = 1;
  33 static const char *head_name;
  34 static char *capabilities_to_send;
  35
  36 static enum deny_action parse_deny_action(const char *var, const char *value)
  37 {
  38         if (value) {
  39                 if (!strcasecmp(value, "ignore"))
  40                         return DENY_IGNORE;
  41                 if (!strcasecmp(value, "warn"))
  42                         return DENY_WARN;
  43                 if (!strcasecmp(value, "refuse"))
  44                         return DENY_REFUSE;
  45         }
  46         if (git_config_bool(var, value))
  47                 return DENY_REFUSE;
  48         return DENY_IGNORE;
  49 }
  50
  51 static int receive_pack_config(const char *var, const char *value, void *cb)
  52 {
  53         if (strcmp(var, "receive.denydeletes") == 0) {
  54                 deny_deletes = git_config_bool(var, value);
  55                 return 0;
  56         }
  57
  58         if (strcmp(var, "receive.denynonfastforwards") == 0) {
  59                 deny_non_fast_forwards = git_config_bool(var, value);
  60                 return 0;
  61         }
  62
  63         if (strcmp(var, "receive.unpacklimit") == 0) {
  64                 receive_unpack_limit = git_config_int(var, value);
  65                 return 0;
  66         }
  67
  68         if (strcmp(var, "transfer.unpacklimit") == 0) {
  69                 transfer_unpack_limit = git_config_int(var, value);
  70                 return 0;
  71         }
  72
  73         if (strcmp(var, "receive.fsckobjects") == 0) {
  74                 receive_fsck_objects = git_config_bool(var, value);
  75                 return 0;
  76         }
  77
  78         if (!strcmp(var, "receive.denycurrentbranch")) {
  79                 deny_current_branch = parse_deny_action(var, value);
  80                 return 0;
  81         }
  82
  83         if (strcmp(var, "receive.denydeletecurrent") == 0) {
  84                 deny_delete_current = parse_deny_action(var, value);
  85                 return 0;
  86         }
  87
  88         if (strcmp(var, "repack.usedeltabaseoffset") == 0) {
  89                 prefer_ofs_delta = git_config_bool(var, value);
  90                 return 0;
  91         }
  92
  93         if (strcmp(var, "receive.updateserverinfo") == 0) {
  94                 auto_update_server_info = git_config_bool(var, value);
  95                 return 0;
  96         }
  97
  98         if (strcmp(var, "receive.autogc") == 0) {
  99                 auto_gc = git_config_bool(var, value);
 100                 return 0;
 101         }
 102
 103         return git_default_config(var, value, cb);
 104 }
 105
 106 static int show_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 107 {
 108         if (!capabilities_to_send)
 109                 packet_write(1, "%s %s\n", sha1_to_hex(sha1), path);
 110         else
 111                 packet_write(1, "%s %s%c%s\n",
 112                              sha1_to_hex(sha1), path, 0, capabilities_to_send);
 113         capabilities_to_send = NULL;
 114         return 0;
 115 }
 116
 117 static void write_head_info(void)
 118 {
 119         for_each_ref(show_ref, NULL);
 120         if (capabilities_to_send)
 121                 show_ref("capabilities^{}", null_sha1, 0, NULL);
 122
 123 }
 124
 125 struct command {
 126         struct command *next;
 127         const char *error_string;
 128         unsigned char old_sha1[20];
 129         unsigned char new_sha1[20];
 130         char ref_name[FLEX_ARRAY]; /* more */
 131 };
 132
 133 static struct command *commands;
 134
 135 static const char pre_receive_hook[] = "hooks/pre-receive";
 136 static const char post_receive_hook[] = "hooks/post-receive";
 137
 138 static int run_receive_hook(const char *hook_name)
 139 {
 140         static char buf[sizeof(commands->old_sha1) * 2 + PATH_MAX + 4];
 141         struct command *cmd;
 142         struct child_process proc;
 143         const char *argv[2];
 144         int have_input = 0, code;
 145
 146         for (cmd = commands; !have_input && cmd; cmd = cmd->next) {
 147                 if (!cmd->error_string)
 148                         have_input = 1;
 149         }
 150
 151         if (!have_input || access(hook_name, X_OK) < 0)
 152                 return 0;
 153
 154         argv[0] = hook_name;
 155         argv[1] = NULL;
 156
 157         memset(&proc, 0, sizeof(proc));
 158         proc.argv = argv;
 159         proc.in = -1;
 160         proc.stdout_to_stderr = 1;
 161
 162         code = start_command(&proc);
 163         if (code)
 164                 return code;
 165         for (cmd = commands; cmd; cmd = cmd->next) {
 166                 if (!cmd->error_string) {
 167                         size_t n = snprintf(buf, sizeof(buf), "%s %s %s\n",
 168                                 sha1_to_hex(cmd->old_sha1),
 169                                 sha1_to_hex(cmd->new_sha1),
 170                                 cmd->ref_name);
 171                         if (write_in_full(proc.in, buf, n) != n)
 172                                 break;
 173                 }
 174         }
 175         close(proc.in);
 176         return finish_command(&proc);
 177 }
 178
 179 static int run_update_hook(struct command *cmd)
 180 {
 181         static const char update_hook[] = "hooks/update";
 182         const char *argv[5];
 183
 184         if (access(update_hook, X_OK) < 0)
 185                 return 0;
 186
 187         argv[0] = update_hook;
 188         argv[1] = cmd->ref_name;
 189         argv[2] = sha1_to_hex(cmd->old_sha1);
 190         argv[3] = sha1_to_hex(cmd->new_sha1);
 191         argv[4] = NULL;
 192
 193         return run_command_v_opt(argv, RUN_COMMAND_NO_STDIN |
 194                                         RUN_COMMAND_STDOUT_TO_STDERR);
 195 }
 196
 197 static int is_ref_checked_out(const char *ref)
 198 {
 199         if (is_bare_repository())
 200                 return 0;
 201
 202         if (!head_name)
 203                 return 0;
 204         return !strcmp(head_name, ref);
 205 }
 206
 207 static char *warn_unconfigured_deny_msg[] = {
 208         "Updating the currently checked out branch may cause confusion,",
 209         "as the index and work tree do not reflect changes that are in HEAD.",
 210         "As a result, you may see the changes you just pushed into it",
 211         "reverted when you run 'git diff' over there, and you may want",
 212         "to run 'git reset --hard' before starting to work to recover.",
 213         "",
 214         "You can set 'receive.denyCurrentBranch' configuration variable to",
 215         "'refuse' in the remote repository to forbid pushing into its",
 216         "current branch."
 217         "",
 218         "To allow pushing into the current branch, you can set it to 'ignore';",
 219         "but this is not recommended unless you arranged to update its work",
 220         "tree to match what you pushed in some other way.",
 221         "",
 222         "To squelch this message, you can set it to 'warn'.",
 223         "",
 224         "Note that the default will change in a future version of git",
 225         "to refuse updating the current branch unless you have the",
 226         "configuration variable set to either 'ignore' or 'warn'."
 227 };
 228
 229 static void warn_unconfigured_deny(void)
 230 {
 231         int i;
 232         for (i = 0; i < ARRAY_SIZE(warn_unconfigured_deny_msg); i++)
 233                 warning("%s", warn_unconfigured_deny_msg[i]);
 234 }
 235
 236 static char *warn_unconfigured_deny_delete_current_msg[] = {
 237         "Deleting the current branch can cause confusion by making the next",
 238         "'git clone' not check out any file.",
 239         "",
 240         "You can set 'receive.denyDeleteCurrent' configuration variable to",
 241         "'refuse' in the remote repository to disallow deleting the current",
 242         "branch.",
 243         "",
 244         "You can set it to 'ignore' to allow such a delete without a warning.",
 245         "",
 246         "To make this warning message less loud, you can set it to 'warn'.",
 247         "",
 248         "Note that the default will change in a future version of git",
 249         "to refuse deleting the current branch unless you have the",
 250         "configuration variable set to either 'ignore' or 'warn'."
 251 };
 252
 253 static void warn_unconfigured_deny_delete_current(void)
 254 {
 255         int i;
 256         for (i = 0;
 257              i < ARRAY_SIZE(warn_unconfigured_deny_delete_current_msg);
 258              i++)
 259                 warning("%s", warn_unconfigured_deny_delete_current_msg[i]);
 260 }
 261
 262 static const char *update(struct command *cmd)
 263 {
 264         const char *name = cmd->ref_name;
 265         unsigned char *old_sha1 = cmd->old_sha1;
 266         unsigned char *new_sha1 = cmd->new_sha1;
 267         struct ref_lock *lock;
 268
 269         /* only refs/... are allowed */
 270         if (prefixcmp(name, "refs/") || check_ref_format(name + 5)) {
 271                 error("refusing to create funny ref '%s' remotely", name);
 272                 return "funny refname";
 273         }
 274
 275         if (is_ref_checked_out(name)) {
 276                 switch (deny_current_branch) {
 277                 case DENY_IGNORE:
 278                         break;
 279                 case DENY_UNCONFIGURED:
 280                 case DENY_WARN:
 281                         warning("updating the current branch");
 282                         if (deny_current_branch == DENY_UNCONFIGURED)
 283                                 warn_unconfigured_deny();
 284                         break;
 285                 case DENY_REFUSE:
 286                         error("refusing to update checked out branch: %s", name);
 287                         return "branch is currently checked out";
 288                 }
 289         }
 290
 291         if (!is_null_sha1(new_sha1) && !has_sha1_file(new_sha1)) {
 292                 error("unpack should have generated %s, "
 293                       "but I can't find it!", sha1_to_hex(new_sha1));
 294                 return "bad pack";
 295         }
 296
 297         if (!is_null_sha1(old_sha1) && is_null_sha1(new_sha1)) {
 298                 if (deny_deletes && !prefixcmp(name, "refs/heads/")) {
 299                         error("denying ref deletion for %s", name);
 300                         return "deletion prohibited";
 301                 }
 302
 303                 if (!strcmp(name, head_name)) {
 304                         switch (deny_delete_current) {
 305                         case DENY_IGNORE:
 306                                 break;
 307                         case DENY_WARN:
 308                         case DENY_UNCONFIGURED:
 309                                 if (deny_delete_current == DENY_UNCONFIGURED)
 310                                         warn_unconfigured_deny_delete_current();
 311                                 warning("deleting the current branch");
 312                                 break;
 313                         case DENY_REFUSE:
 314                                 error("refusing to delete the current branch: %s", name);
 315                                 return "deletion of the current branch prohibited";
 316                         }
 317                 }
 318         }
 319
 320         if (deny_non_fast_forwards && !is_null_sha1(new_sha1) &&
 321             !is_null_sha1(old_sha1) &&
 322             !prefixcmp(name, "refs/heads/")) {
 323                 struct object *old_object, *new_object;
 324                 struct commit *old_commit, *new_commit;
 325                 struct commit_list *bases, *ent;
 326
 327                 old_object = parse_object(old_sha1);
 328                 new_object = parse_object(new_sha1);
 329
 330                 if (!old_object || !new_object ||
 331                     old_object->type != OBJ_COMMIT ||
 332                     new_object->type != OBJ_COMMIT) {
 333                         error("bad sha1 objects for %s", name);
 334                         return "bad ref";
 335                 }
 336                 old_commit = (struct commit *)old_object;
 337                 new_commit = (struct commit *)new_object;
 338                 bases = get_merge_bases(old_commit, new_commit, 1);
 339                 for (ent = bases; ent; ent = ent->next)
 340                         if (!hashcmp(old_sha1, ent->item->object.sha1))
 341                                 break;
 342                 free_commit_list(bases);
 343                 if (!ent) {
 344                         error("denying non-fast-forward %s"
 345                               " (you should pull first)", name);
 346                         return "non-fast-forward";
 347                 }
 348         }
 349         if (run_update_hook(cmd)) {
 350                 error("hook declined to update %s", name);
 351                 return "hook declined";
 352         }
 353
 354         if (is_null_sha1(new_sha1)) {
 355                 if (!parse_object(old_sha1)) {
 356                         warning ("Allowing deletion of corrupt ref.");
 357                         old_sha1 = NULL;
 358                 }
 359                 if (delete_ref(name, old_sha1, 0)) {
 360                         error("failed to delete %s", name);
 361                         return "failed to delete";
 362                 }
 363                 return NULL; /* good */
 364         }
 365         else {
 366                 lock = lock_any_ref_for_update(name, old_sha1, 0);
 367                 if (!lock) {
 368                         error("failed to lock %s", name);
 369                         return "failed to lock";
 370                 }
 371                 if (write_ref_sha1(lock, new_sha1, "push")) {
 372                         return "failed to write"; /* error() already called */
 373                 }
 374                 return NULL; /* good */
 375         }
 376 }
 377
 378 static char update_post_hook[] = "hooks/post-update";
 379
 380 static void run_update_post_hook(struct command *cmd)
 381 {
 382         struct command *cmd_p;
 383         int argc, status;
 384         const char **argv;
 385
 386         for (argc = 0, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
 387                 if (cmd_p->error_string)
 388                         continue;
 389                 argc++;
 390         }
 391         if (!argc || access(update_post_hook, X_OK) < 0)
 392                 return;
 393         argv = xmalloc(sizeof(*argv) * (2 + argc));
 394         argv[0] = update_post_hook;
 395
 396         for (argc = 1, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
 397                 char *p;
 398                 if (cmd_p->error_string)
 399                         continue;
 400                 p = xmalloc(strlen(cmd_p->ref_name) + 1);
 401                 strcpy(p, cmd_p->ref_name);
 402                 argv[argc] = p;
 403                 argc++;
 404         }
 405         argv[argc] = NULL;
 406         status = run_command_v_opt(argv, RUN_COMMAND_NO_STDIN
 407                         | RUN_COMMAND_STDOUT_TO_STDERR);
 408 }
 409
 410 static void execute_commands(const char *unpacker_error)
 411 {
 412         struct command *cmd = commands;
 413         unsigned char sha1[20];
 414
 415         if (unpacker_error) {
 416                 while (cmd) {
 417                         cmd->error_string = "n/a (unpacker error)";
 418                         cmd = cmd->next;
 419                 }
 420                 return;
 421         }
 422
 423         if (run_receive_hook(pre_receive_hook)) {
 424                 while (cmd) {
 425                         cmd->error_string = "pre-receive hook declined";
 426                         cmd = cmd->next;
 427                 }
 428                 return;
 429         }
 430
 431         head_name = resolve_ref("HEAD", sha1, 0, NULL);
 432
 433         while (cmd) {
 434                 cmd->error_string = update(cmd);
 435                 cmd = cmd->next;
 436         }
 437 }
 438
 439 static void read_head_info(void)
 440 {
 441         struct command **p = &commands;
 442         for (;;) {
 443                 static char line[1000];
 444                 unsigned char old_sha1[20], new_sha1[20];
 445                 struct command *cmd;
 446                 char *refname;
 447                 int len, reflen;
 448
 449                 len = packet_read_line(0, line, sizeof(line));
 450                 if (!len)
 451                         break;
 452                 if (line[len-1] == '\n')
 453                         line[--len] = 0;
 454                 if (len < 83 ||
 455                     line[40] != ' ' ||
 456                     line[81] != ' ' ||
 457                     get_sha1_hex(line, old_sha1) ||
 458                     get_sha1_hex(line + 41, new_sha1))
 459                         die("protocol error: expected old/new/ref, got '%s'",
 460                             line);
 461
 462                 refname = line + 82;
 463                 reflen = strlen(refname);
 464                 if (reflen + 82 < len) {
 465                         if (strstr(refname + reflen + 1, "report-status"))
 466                                 report_status = 1;
 467                 }
 468                 cmd = xmalloc(sizeof(struct command) + len - 80);
 469                 hashcpy(cmd->old_sha1, old_sha1);
 470                 hashcpy(cmd->new_sha1, new_sha1);
 471                 memcpy(cmd->ref_name, line + 82, len - 81);
 472                 cmd->error_string = NULL;
 473                 cmd->next = NULL;
 474                 *p = cmd;
 475                 p = &cmd->next;
 476         }
 477 }
 478
 479 static const char *parse_pack_header(struct pack_header *hdr)
 480 {
 481         switch (read_pack_header(0, hdr)) {
 482         case PH_ERROR_EOF:
 483                 return "eof before pack header was fully read";
 484
 485         case PH_ERROR_PACK_SIGNATURE:
 486                 return "protocol error (pack signature mismatch detected)";
 487
 488         case PH_ERROR_PROTOCOL:
 489                 return "protocol error (pack version unsupported)";
 490
 491         default:
 492                 return "unknown error in parse_pack_header";
 493
 494         case 0:
 495                 return NULL;
 496         }
 497 }
 498
 499 static const char *pack_lockfile;
 500
 501 static const char *unpack(void)
 502 {
 503         struct pack_header hdr;
 504         const char *hdr_err;
 505         char hdr_arg[38];
 506
 507         hdr_err = parse_pack_header(&hdr);
 508         if (hdr_err)
 509                 return hdr_err;
 510         snprintf(hdr_arg, sizeof(hdr_arg),
 511                         "--pack_header=%"PRIu32",%"PRIu32,
 512                         ntohl(hdr.hdr_version), ntohl(hdr.hdr_entries));
 513
 514         if (ntohl(hdr.hdr_entries) < unpack_limit) {
 515                 int code, i = 0;
 516                 const char *unpacker[4];
 517                 unpacker[i++] = "unpack-objects";
 518                 if (receive_fsck_objects)
 519                         unpacker[i++] = "--strict";
 520                 unpacker[i++] = hdr_arg;
 521                 unpacker[i++] = NULL;
 522                 code = run_command_v_opt(unpacker, RUN_GIT_CMD);
 523                 if (!code)
 524                         return NULL;
 525                 return "unpack-objects abnormal exit";
 526         } else {
 527                 const char *keeper[7];
 528                 int s, status, i = 0;
 529                 char keep_arg[256];
 530                 struct child_process ip;
 531
 532                 s = sprintf(keep_arg, "--keep=receive-pack %"PRIuMAX" on ", (uintmax_t) getpid());
 533                 if (gethostname(keep_arg + s, sizeof(keep_arg) - s))
 534                         strcpy(keep_arg + s, "localhost");
 535
 536                 keeper[i++] = "index-pack";
 537                 keeper[i++] = "--stdin";
 538                 if (receive_fsck_objects)
 539                         keeper[i++] = "--strict";
 540                 keeper[i++] = "--fix-thin";
 541                 keeper[i++] = hdr_arg;
 542                 keeper[i++] = keep_arg;
 543                 keeper[i++] = NULL;
 544                 memset(&ip, 0, sizeof(ip));
 545                 ip.argv = keeper;
 546                 ip.out = -1;
 547                 ip.git_cmd = 1;
 548                 status = start_command(&ip);
 549                 if (status) {
 550                         return "index-pack fork failed";
 551                 }
 552                 pack_lockfile = index_pack_lockfile(ip.out);
 553                 close(ip.out);
 554                 status = finish_command(&ip);
 555                 if (!status) {
 556                         reprepare_packed_git();
 557                         return NULL;
 558                 }
 559                 return "index-pack abnormal exit";
 560         }
 561 }
 562
 563 static void report(const char *unpack_status)
 564 {
 565         struct command *cmd;
 566         packet_write(1, "unpack %s\n",
 567                      unpack_status ? unpack_status : "ok");
 568         for (cmd = commands; cmd; cmd = cmd->next) {
 569                 if (!cmd->error_string)
 570                         packet_write(1, "ok %s\n",
 571                                      cmd->ref_name);
 572                 else
 573                         packet_write(1, "ng %s %s\n",
 574                                      cmd->ref_name, cmd->error_string);
 575         }
 576         packet_flush(1);
 577 }
 578
 579 static int delete_only(struct command *cmd)
 580 {
 581         while (cmd) {
 582                 if (!is_null_sha1(cmd->new_sha1))
 583                         return 0;
 584                 cmd = cmd->next;
 585         }
 586         return 1;
 587 }
 588
 589 static int add_refs_from_alternate(struct alternate_object_database *e, void *unused)
 590 {
 591         char *other;
 592         size_t len;
 593         struct remote *remote;
 594         struct transport *transport;
 595         const struct ref *extra;
 596
 597         e->name[-1] = '\0';
 598         other = xstrdup(make_absolute_path(e->base));
 599         e->name[-1] = '/';
 600         len = strlen(other);
 601
 602         while (other[len-1] == '/')
 603                 other[--len] = '\0';
 604         if (len < 8 || memcmp(other + len - 8, "/objects", 8))
 605                 return 0;
 606         /* Is this a git repository with refs? */
 607         memcpy(other + len - 8, "/refs", 6);
 608         if (!is_directory(other))
 609                 return 0;
 610         other[len - 8] = '\0';
 611         remote = remote_get(other);
 612         transport = transport_get(remote, other);
 613         for (extra = transport_get_remote_refs(transport);
 614              extra;
 615              extra = extra->next) {
 616                 add_extra_ref(".have", extra->old_sha1, 0);
 617         }
 618         transport_disconnect(transport);
 619         free(other);
 620         return 0;
 621 }
 622
 623 static void add_alternate_refs(void)
 624 {
 625         foreach_alt_odb(add_refs_from_alternate, NULL);
 626 }
 627
 628 int cmd_receive_pack(int argc, const char **argv, const char *prefix)
 629 {
 630         int i;
 631         char *dir = NULL;
 632
 633         argv++;
 634         for (i = 1; i < argc; i++) {
 635                 const char *arg = *argv++;
 636
 637                 if (*arg == '-') {
 638                         /* Do flag handling here */
 639                         usage(receive_pack_usage);
 640                 }
 641                 if (dir)
 642                         usage(receive_pack_usage);
 643                 dir = xstrdup(arg);
 644         }
 645         if (!dir)
 646                 usage(receive_pack_usage);
 647
 648         setup_path();
 649
 650         if (!enter_repo(dir, 0))
 651                 die("'%s' does not appear to be a git repository", dir);
 652
 653         if (is_repository_shallow())
 654                 die("attempt to push into a shallow repository");
 655
 656         git_config(receive_pack_config, NULL);
 657
 658         if (0 <= transfer_unpack_limit)
 659                 unpack_limit = transfer_unpack_limit;
 660         else if (0 <= receive_unpack_limit)
 661                 unpack_limit = receive_unpack_limit;
 662
 663         capabilities_to_send = (prefer_ofs_delta) ?
 664                 " report-status delete-refs ofs-delta " :
 665                 " report-status delete-refs ";
 666
 667         add_alternate_refs();
 668         write_head_info();
 669         clear_extra_refs();
 670
 671         /* EOF */
 672         packet_flush(1);
 673
 674         read_head_info();
 675         if (commands) {
 676                 const char *unpack_status = NULL;
 677
 678                 if (!delete_only(commands))
 679                         unpack_status = unpack();
 680                 execute_commands(unpack_status);
 681                 if (pack_lockfile)
 682                         unlink_or_warn(pack_lockfile);
 683                 if (report_status)
 684                         report(unpack_status);
 685                 run_receive_hook(post_receive_hook);
 686                 run_update_post_hook(commands);
 687                 if (auto_gc) {
 688                         const char *argv_gc_auto[] = {
 689                                 "gc", "--auto", "--quiet", NULL,
 690                         };
 691                         run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
 692                 }
 693                 if (auto_update_server_info)
 694                         update_server_info(0);
 695         }
 696         return 0;
 697 }