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