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