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