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_IGNORE,
  16         DENY_WARN,
  17         DENY_REFUSE,
  18 };
  19
  20 static int deny_deletes = 0;
  21 static int deny_non_fast_forwards = 0;
  22 static enum deny_action deny_current_branch = DENY_WARN;
  23 static int receive_fsck_objects;
  24 static int receive_unpack_limit = -1;
  25 static int transfer_unpack_limit = -1;
  26 static int unpack_limit = 100;
  27 static int report_status;
  28
  29 static char capabilities[] = " report-status delete-refs ";
  30 static int capabilities_sent;
  31
  32 static enum deny_action parse_deny_action(const char *var, const char *value)
  33 {
  34         if (value) {
  35                 if (!strcasecmp(value, "ignore"))
  36                         return DENY_IGNORE;
  37                 if (!strcasecmp(value, "warn"))
  38                         return DENY_WARN;
  39                 if (!strcasecmp(value, "refuse"))
  40                         return DENY_REFUSE;
  41         }
  42         if (git_config_bool(var, value))
  43                 return DENY_REFUSE;
  44         return DENY_IGNORE;
  45 }
  46
  47 static int receive_pack_config(const char *var, const char *value, void *cb)
  48 {
  49         if (strcmp(var, "receive.denydeletes") == 0) {
  50                 deny_deletes = git_config_bool(var, value);
  51                 return 0;
  52         }
  53
  54         if (strcmp(var, "receive.denynonfastforwards") == 0) {
  55                 deny_non_fast_forwards = git_config_bool(var, value);
  56                 return 0;
  57         }
  58
  59         if (strcmp(var, "receive.unpacklimit") == 0) {
  60                 receive_unpack_limit = git_config_int(var, value);
  61                 return 0;
  62         }
  63
  64         if (strcmp(var, "transfer.unpacklimit") == 0) {
  65                 transfer_unpack_limit = git_config_int(var, value);
  66                 return 0;
  67         }
  68
  69         if (strcmp(var, "receive.fsckobjects") == 0) {
  70                 receive_fsck_objects = git_config_bool(var, value);
  71                 return 0;
  72         }
  73
  74         if (!strcmp(var, "receive.denycurrentbranch")) {
  75                 deny_current_branch = parse_deny_action(var, value);
  76                 return 0;
  77         }
  78
  79         return git_default_config(var, value, cb);
  80 }
  81
  82 static int show_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
  83 {
  84         if (capabilities_sent)
  85                 packet_write(1, "%s %s\n", sha1_to_hex(sha1), path);
  86         else
  87                 packet_write(1, "%s %s%c%s\n",
  88                              sha1_to_hex(sha1), path, 0, capabilities);
  89         capabilities_sent = 1;
  90         return 0;
  91 }
  92
  93 static void write_head_info(void)
  94 {
  95         for_each_ref(show_ref, NULL);
  96         if (!capabilities_sent)
  97                 show_ref("capabilities^{}", null_sha1, 0, NULL);
  98
  99 }
 100
 101 struct command {
 102         struct command *next;
 103         const char *error_string;
 104         unsigned char old_sha1[20];
 105         unsigned char new_sha1[20];
 106         char ref_name[FLEX_ARRAY]; /* more */
 107 };
 108
 109 static struct command *commands;
 110
 111 static const char pre_receive_hook[] = "hooks/pre-receive";
 112 static const char post_receive_hook[] = "hooks/post-receive";
 113
 114 static int hook_status(int code, const char *hook_name)
 115 {
 116         switch (code) {
 117         case 0:
 118                 return 0;
 119         case -ERR_RUN_COMMAND_FORK:
 120                 return error("hook fork failed");
 121         case -ERR_RUN_COMMAND_EXEC:
 122                 return error("hook execute failed");
 123         case -ERR_RUN_COMMAND_PIPE:
 124                 return error("hook pipe failed");
 125         case -ERR_RUN_COMMAND_WAITPID:
 126                 return error("waitpid failed");
 127         case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
 128                 return error("waitpid is confused");
 129         case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
 130                 return error("%s died of signal", hook_name);
 131         case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
 132                 return error("%s died strangely", hook_name);
 133         default:
 134                 error("%s exited with error code %d", hook_name, -code);
 135                 return -code;
 136         }
 137 }
 138
 139 static int run_hook(const char *hook_name)
 140 {
 141         static char buf[sizeof(commands->old_sha1) * 2 + PATH_MAX + 4];
 142         struct command *cmd;
 143         struct child_process proc;
 144         const char *argv[2];
 145         int have_input = 0, code;
 146
 147         for (cmd = commands; !have_input && cmd; cmd = cmd->next) {
 148                 if (!cmd->error_string)
 149                         have_input = 1;
 150         }
 151
 152         if (!have_input || access(hook_name, X_OK) < 0)
 153                 return 0;
 154
 155         argv[0] = hook_name;
 156         argv[1] = NULL;
 157
 158         memset(&proc, 0, sizeof(proc));
 159         proc.argv = argv;
 160         proc.in = -1;
 161         proc.stdout_to_stderr = 1;
 162
 163         code = start_command(&proc);
 164         if (code)
 165                 return hook_status(code, hook_name);
 166         for (cmd = commands; cmd; cmd = cmd->next) {
 167                 if (!cmd->error_string) {
 168                         size_t n = snprintf(buf, sizeof(buf), "%s %s %s\n",
 169                                 sha1_to_hex(cmd->old_sha1),
 170                                 sha1_to_hex(cmd->new_sha1),
 171                                 cmd->ref_name);
 172                         if (write_in_full(proc.in, buf, n) != n)
 173                                 break;
 174                 }
 175         }
 176         close(proc.in);
 177         return hook_status(finish_command(&proc), hook_name);
 178 }
 179
 180 static int run_update_hook(struct command *cmd)
 181 {
 182         static const char update_hook[] = "hooks/update";
 183         struct child_process proc;
 184         const char *argv[5];
 185
 186         if (access(update_hook, X_OK) < 0)
 187                 return 0;
 188
 189         argv[0] = update_hook;
 190         argv[1] = cmd->ref_name;
 191         argv[2] = sha1_to_hex(cmd->old_sha1);
 192         argv[3] = sha1_to_hex(cmd->new_sha1);
 193         argv[4] = NULL;
 194
 195         memset(&proc, 0, sizeof(proc));
 196         proc.argv = argv;
 197         proc.no_stdin = 1;
 198         proc.stdout_to_stderr = 1;
 199
 200         return hook_status(run_command(&proc), update_hook);
 201 }
 202
 203 static int is_ref_checked_out(const char *ref)
 204 {
 205         unsigned char sha1[20];
 206         const char *head;
 207
 208         if (is_bare_repository())
 209                 return 0;
 210
 211         head = resolve_ref("HEAD", sha1, 0, NULL);
 212         if (!head)
 213                 return 0;
 214         return !strcmp(head, ref);
 215 }
 216
 217 static const char *update(struct command *cmd)
 218 {
 219         const char *name = cmd->ref_name;
 220         unsigned char *old_sha1 = cmd->old_sha1;
 221         unsigned char *new_sha1 = cmd->new_sha1;
 222         struct ref_lock *lock;
 223
 224         /* only refs/... are allowed */
 225         if (prefixcmp(name, "refs/") || check_ref_format(name + 5)) {
 226                 error("refusing to create funny ref '%s' remotely", name);
 227                 return "funny refname";
 228         }
 229
 230         switch (deny_current_branch) {
 231         case DENY_IGNORE:
 232                 break;
 233         case DENY_WARN:
 234                 if (!is_ref_checked_out(name))
 235                         break;
 236                 warning("updating the currently checked out branch; this may"
 237                         " cause confusion,\n"
 238                         "as the index and working tree do not reflect changes"
 239                         " that are now in HEAD.");
 240                 break;
 241         case DENY_REFUSE:
 242                 if (!is_ref_checked_out(name))
 243                         break;
 244                 error("refusing to update checked out branch: %s", name);
 245                 return "branch is currently checked out";
 246         }
 247
 248         if (!is_null_sha1(new_sha1) && !has_sha1_file(new_sha1)) {
 249                 error("unpack should have generated %s, "
 250                       "but I can't find it!", sha1_to_hex(new_sha1));
 251                 return "bad pack";
 252         }
 253         if (deny_deletes && is_null_sha1(new_sha1) &&
 254             !is_null_sha1(old_sha1) &&
 255             !prefixcmp(name, "refs/heads/")) {
 256                 error("denying ref deletion for %s", name);
 257                 return "deletion prohibited";
 258         }
 259         if (deny_non_fast_forwards && !is_null_sha1(new_sha1) &&
 260             !is_null_sha1(old_sha1) &&
 261             !prefixcmp(name, "refs/heads/")) {
 262                 struct object *old_object, *new_object;
 263                 struct commit *old_commit, *new_commit;
 264                 struct commit_list *bases, *ent;
 265
 266                 old_object = parse_object(old_sha1);
 267                 new_object = parse_object(new_sha1);
 268
 269                 if (!old_object || !new_object ||
 270                     old_object->type != OBJ_COMMIT ||
 271                     new_object->type != OBJ_COMMIT) {
 272                         error("bad sha1 objects for %s", name);
 273                         return "bad ref";
 274                 }
 275                 old_commit = (struct commit *)old_object;
 276                 new_commit = (struct commit *)new_object;
 277                 bases = get_merge_bases(old_commit, new_commit, 1);
 278                 for (ent = bases; ent; ent = ent->next)
 279                         if (!hashcmp(old_sha1, ent->item->object.sha1))
 280                                 break;
 281                 free_commit_list(bases);
 282                 if (!ent) {
 283                         error("denying non-fast forward %s"
 284                               " (you should pull first)", name);
 285                         return "non-fast forward";
 286                 }
 287         }
 288         if (run_update_hook(cmd)) {
 289                 error("hook declined to update %s", name);
 290                 return "hook declined";
 291         }
 292
 293         if (is_null_sha1(new_sha1)) {
 294                 if (!parse_object(old_sha1)) {
 295                         warning ("Allowing deletion of corrupt ref.");
 296                         old_sha1 = NULL;
 297                 }
 298                 if (delete_ref(name, old_sha1, 0)) {
 299                         error("failed to delete %s", name);
 300                         return "failed to delete";
 301                 }
 302                 return NULL; /* good */
 303         }
 304         else {
 305                 lock = lock_any_ref_for_update(name, old_sha1, 0);
 306                 if (!lock) {
 307                         error("failed to lock %s", name);
 308                         return "failed to lock";
 309                 }
 310                 if (write_ref_sha1(lock, new_sha1, "push")) {
 311                         return "failed to write"; /* error() already called */
 312                 }
 313                 return NULL; /* good */
 314         }
 315 }
 316
 317 static char update_post_hook[] = "hooks/post-update";
 318
 319 static void run_update_post_hook(struct command *cmd)
 320 {
 321         struct command *cmd_p;
 322         int argc;
 323         const char **argv;
 324
 325         for (argc = 0, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
 326                 if (cmd_p->error_string)
 327                         continue;
 328                 argc++;
 329         }
 330         if (!argc || access(update_post_hook, X_OK) < 0)
 331                 return;
 332         argv = xmalloc(sizeof(*argv) * (2 + argc));
 333         argv[0] = update_post_hook;
 334
 335         for (argc = 1, cmd_p = cmd; cmd_p; cmd_p = cmd_p->next) {
 336                 char *p;
 337                 if (cmd_p->error_string)
 338                         continue;
 339                 p = xmalloc(strlen(cmd_p->ref_name) + 1);
 340                 strcpy(p, cmd_p->ref_name);
 341                 argv[argc] = p;
 342                 argc++;
 343         }
 344         argv[argc] = NULL;
 345         run_command_v_opt(argv, RUN_COMMAND_NO_STDIN
 346                 | RUN_COMMAND_STDOUT_TO_STDERR);
 347 }
 348
 349 static void execute_commands(const char *unpacker_error)
 350 {
 351         struct command *cmd = commands;
 352
 353         if (unpacker_error) {
 354                 while (cmd) {
 355                         cmd->error_string = "n/a (unpacker error)";
 356                         cmd = cmd->next;
 357                 }
 358                 return;
 359         }
 360
 361         if (run_hook(pre_receive_hook)) {
 362                 while (cmd) {
 363                         cmd->error_string = "pre-receive hook declined";
 364                         cmd = cmd->next;
 365                 }
 366                 return;
 367         }
 368
 369         while (cmd) {
 370                 cmd->error_string = update(cmd);
 371                 cmd = cmd->next;
 372         }
 373 }
 374
 375 static void read_head_info(void)
 376 {
 377         struct command **p = &commands;
 378         for (;;) {
 379                 static char line[1000];
 380                 unsigned char old_sha1[20], new_sha1[20];
 381                 struct command *cmd;
 382                 char *refname;
 383                 int len, reflen;
 384
 385                 len = packet_read_line(0, line, sizeof(line));
 386                 if (!len)
 387                         break;
 388                 if (line[len-1] == '\n')
 389                         line[--len] = 0;
 390                 if (len < 83 ||
 391                     line[40] != ' ' ||
 392                     line[81] != ' ' ||
 393                     get_sha1_hex(line, old_sha1) ||
 394                     get_sha1_hex(line + 41, new_sha1))
 395                         die("protocol error: expected old/new/ref, got '%s'",
 396                             line);
 397
 398                 refname = line + 82;
 399                 reflen = strlen(refname);
 400                 if (reflen + 82 < len) {
 401                         if (strstr(refname + reflen + 1, "report-status"))
 402                                 report_status = 1;
 403                 }
 404                 cmd = xmalloc(sizeof(struct command) + len - 80);
 405                 hashcpy(cmd->old_sha1, old_sha1);
 406                 hashcpy(cmd->new_sha1, new_sha1);
 407                 memcpy(cmd->ref_name, line + 82, len - 81);
 408                 cmd->error_string = NULL;
 409                 cmd->next = NULL;
 410                 *p = cmd;
 411                 p = &cmd->next;
 412         }
 413 }
 414
 415 static const char *parse_pack_header(struct pack_header *hdr)
 416 {
 417         switch (read_pack_header(0, hdr)) {
 418         case PH_ERROR_EOF:
 419                 return "eof before pack header was fully read";
 420
 421         case PH_ERROR_PACK_SIGNATURE:
 422                 return "protocol error (pack signature mismatch detected)";
 423
 424         case PH_ERROR_PROTOCOL:
 425                 return "protocol error (pack version unsupported)";
 426
 427         default:
 428                 return "unknown error in parse_pack_header";
 429
 430         case 0:
 431                 return NULL;
 432         }
 433 }
 434
 435 static const char *pack_lockfile;
 436
 437 static const char *unpack(void)
 438 {
 439         struct pack_header hdr;
 440         const char *hdr_err;
 441         char hdr_arg[38];
 442
 443         hdr_err = parse_pack_header(&hdr);
 444         if (hdr_err)
 445                 return hdr_err;
 446         snprintf(hdr_arg, sizeof(hdr_arg),
 447                         "--pack_header=%"PRIu32",%"PRIu32,
 448                         ntohl(hdr.hdr_version), ntohl(hdr.hdr_entries));
 449
 450         if (ntohl(hdr.hdr_entries) < unpack_limit) {
 451                 int code, i = 0;
 452                 const char *unpacker[4];
 453                 unpacker[i++] = "unpack-objects";
 454                 if (receive_fsck_objects)
 455                         unpacker[i++] = "--strict";
 456                 unpacker[i++] = hdr_arg;
 457                 unpacker[i++] = NULL;
 458                 code = run_command_v_opt(unpacker, RUN_GIT_CMD);
 459                 switch (code) {
 460                 case 0:
 461                         return NULL;
 462                 case -ERR_RUN_COMMAND_FORK:
 463                         return "unpack fork failed";
 464                 case -ERR_RUN_COMMAND_EXEC:
 465                         return "unpack execute failed";
 466                 case -ERR_RUN_COMMAND_WAITPID:
 467                         return "waitpid failed";
 468                 case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
 469                         return "waitpid is confused";
 470                 case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
 471                         return "unpacker died of signal";
 472                 case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
 473                         return "unpacker died strangely";
 474                 default:
 475                         return "unpacker exited with error code";
 476                 }
 477         } else {
 478                 const char *keeper[7];
 479                 int s, status, i = 0;
 480                 char keep_arg[256];
 481                 struct child_process ip;
 482
 483                 s = sprintf(keep_arg, "--keep=receive-pack %"PRIuMAX" on ", (uintmax_t) getpid());
 484                 if (gethostname(keep_arg + s, sizeof(keep_arg) - s))
 485                         strcpy(keep_arg + s, "localhost");
 486
 487                 keeper[i++] = "index-pack";
 488                 keeper[i++] = "--stdin";
 489                 if (receive_fsck_objects)
 490                         keeper[i++] = "--strict";
 491                 keeper[i++] = "--fix-thin";
 492                 keeper[i++] = hdr_arg;
 493                 keeper[i++] = keep_arg;
 494                 keeper[i++] = NULL;
 495                 memset(&ip, 0, sizeof(ip));
 496                 ip.argv = keeper;
 497                 ip.out = -1;
 498                 ip.git_cmd = 1;
 499                 if (start_command(&ip))
 500                         return "index-pack fork failed";
 501                 pack_lockfile = index_pack_lockfile(ip.out);
 502                 close(ip.out);
 503                 status = finish_command(&ip);
 504                 if (!status) {
 505                         reprepare_packed_git();
 506                         return NULL;
 507                 }
 508                 return "index-pack abnormal exit";
 509         }
 510 }
 511
 512 static void report(const char *unpack_status)
 513 {
 514         struct command *cmd;
 515         packet_write(1, "unpack %s\n",
 516                      unpack_status ? unpack_status : "ok");
 517         for (cmd = commands; cmd; cmd = cmd->next) {
 518                 if (!cmd->error_string)
 519                         packet_write(1, "ok %s\n",
 520                                      cmd->ref_name);
 521                 else
 522                         packet_write(1, "ng %s %s\n",
 523                                      cmd->ref_name, cmd->error_string);
 524         }
 525         packet_flush(1);
 526 }
 527
 528 static int delete_only(struct command *cmd)
 529 {
 530         while (cmd) {
 531                 if (!is_null_sha1(cmd->new_sha1))
 532                         return 0;
 533                 cmd = cmd->next;
 534         }
 535         return 1;
 536 }
 537
 538 static int add_refs_from_alternate(struct alternate_object_database *e, void *unused)
 539 {
 540         char *other;
 541         size_t len;
 542         struct remote *remote;
 543         struct transport *transport;
 544         const struct ref *extra;
 545
 546         e->name[-1] = '\0';
 547         other = xstrdup(make_absolute_path(e->base));
 548         e->name[-1] = '/';
 549         len = strlen(other);
 550
 551         while (other[len-1] == '/')
 552                 other[--len] = '\0';
 553         if (len < 8 || memcmp(other + len - 8, "/objects", 8))
 554                 return 0;
 555         /* Is this a git repository with refs? */
 556         memcpy(other + len - 8, "/refs", 6);
 557         if (!is_directory(other))
 558                 return 0;
 559         other[len - 8] = '\0';
 560         remote = remote_get(other);
 561         transport = transport_get(remote, other);
 562         for (extra = transport_get_remote_refs(transport);
 563              extra;
 564              extra = extra->next) {
 565                 add_extra_ref(".have", extra->old_sha1, 0);
 566         }
 567         transport_disconnect(transport);
 568         free(other);
 569         return 0;
 570 }
 571
 572 static void add_alternate_refs(void)
 573 {
 574         foreach_alt_odb(add_refs_from_alternate, NULL);
 575 }
 576
 577 int cmd_receive_pack(int argc, const char **argv, const char *prefix)
 578 {
 579         int i;
 580         char *dir = NULL;
 581
 582         if (argv[0] && *argv[0])
 583                 git_extract_argv0_path(argv[0]);
 584
 585         argv++;
 586         for (i = 1; i < argc; i++) {
 587                 const char *arg = *argv++;
 588
 589                 if (*arg == '-') {
 590                         /* Do flag handling here */
 591                         usage(receive_pack_usage);
 592                 }
 593                 if (dir)
 594                         usage(receive_pack_usage);
 595                 dir = xstrdup(arg);
 596         }
 597         if (!dir)
 598                 usage(receive_pack_usage);
 599
 600         setup_path();
 601
 602         if (!enter_repo(dir, 0))
 603                 die("'%s': unable to chdir or not a git archive", dir);
 604
 605         if (is_repository_shallow())
 606                 die("attempt to push into a shallow repository");
 607
 608         git_config(receive_pack_config, NULL);
 609
 610         if (0 <= transfer_unpack_limit)
 611                 unpack_limit = transfer_unpack_limit;
 612         else if (0 <= receive_unpack_limit)
 613                 unpack_limit = receive_unpack_limit;
 614
 615         add_alternate_refs();
 616         write_head_info();
 617         clear_extra_refs();
 618
 619         /* EOF */
 620         packet_flush(1);
 621
 622         read_head_info();
 623         if (commands) {
 624                 const char *unpack_status = NULL;
 625
 626                 if (!delete_only(commands))
 627                         unpack_status = unpack();
 628                 execute_commands(unpack_status);
 629                 if (pack_lockfile)
 630                         unlink(pack_lockfile);
 631                 if (report_status)
 632                         report(unpack_status);
 633                 run_hook(post_receive_hook);
 634                 run_update_post_hook(commands);
 635         }
 636         return 0;
 637 }