builtin/receive-pack.c

   1 #include "builtin.h"
   2 #include "pack.h"
   3 #include "refs.h"
   4 #include "pkt-line.h"
   5 #include "sideband.h"
   6 #include "run-command.h"
   7 #include "exec_cmd.h"
   8 #include "commit.h"
   9 #include "object.h"
  10 #include "remote.h"
  11 #include "connect.h"
  12 #include "transport.h"
  13 #include "string-list.h"
  14 #include "sha1-array.h"
  15 #include "connected.h"
  16 #include "argv-array.h"
  17 #include "version.h"
  18
  19 static const char receive_pack_usage[] = "git receive-pack <git-dir>";
  20
  21 enum deny_action {
  22         DENY_UNCONFIGURED,
  23         DENY_IGNORE,
  24         DENY_WARN,
  25         DENY_REFUSE
  26 };
  27
  28 static int deny_deletes;
  29 static int deny_non_fast_forwards;
  30 static enum deny_action deny_current_branch = DENY_UNCONFIGURED;
  31 static enum deny_action deny_delete_current = DENY_UNCONFIGURED;
  32 static int receive_fsck_objects = -1;
  33 static int transfer_fsck_objects = -1;
  34 static int receive_unpack_limit = -1;
  35 static int transfer_unpack_limit = -1;
  36 static int unpack_limit = 100;
  37 static int report_status;
  38 static int use_sideband;
  39 static int quiet;
  40 static int prefer_ofs_delta = 1;
  41 static int auto_update_server_info;
  42 static int auto_gc = 1;
  43 static int fix_thin = 1;
  44 static const char *head_name;
  45 static void *head_name_to_free;
  46 static int sent_capabilities;
  47 static int shallow_update;
  48 static const char *alt_shallow_file;
  49
  50 static enum deny_action parse_deny_action(const char *var, const char *value)
  51 {
  52         if (value) {
  53                 if (!strcasecmp(value, "ignore"))
  54                         return DENY_IGNORE;
  55                 if (!strcasecmp(value, "warn"))
  56                         return DENY_WARN;
  57                 if (!strcasecmp(value, "refuse"))
  58                         return DENY_REFUSE;
  59         }
  60         if (git_config_bool(var, value))
  61                 return DENY_REFUSE;
  62         return DENY_IGNORE;
  63 }
  64
  65 static int receive_pack_config(const char *var, const char *value, void *cb)
  66 {
  67         int status = parse_hide_refs_config(var, value, "receive");
  68
  69         if (status)
  70                 return status;
  71
  72         if (strcmp(var, "receive.denydeletes") == 0) {
  73                 deny_deletes = git_config_bool(var, value);
  74                 return 0;
  75         }
  76
  77         if (strcmp(var, "receive.denynonfastforwards") == 0) {
  78                 deny_non_fast_forwards = git_config_bool(var, value);
  79                 return 0;
  80         }
  81
  82         if (strcmp(var, "receive.unpacklimit") == 0) {
  83                 receive_unpack_limit = git_config_int(var, value);
  84                 return 0;
  85         }
  86
  87         if (strcmp(var, "transfer.unpacklimit") == 0) {
  88                 transfer_unpack_limit = git_config_int(var, value);
  89                 return 0;
  90         }
  91
  92         if (strcmp(var, "receive.fsckobjects") == 0) {
  93                 receive_fsck_objects = git_config_bool(var, value);
  94                 return 0;
  95         }
  96
  97         if (strcmp(var, "transfer.fsckobjects") == 0) {
  98                 transfer_fsck_objects = git_config_bool(var, value);
  99                 return 0;
 100         }
 101
 102         if (!strcmp(var, "receive.denycurrentbranch")) {
 103                 deny_current_branch = parse_deny_action(var, value);
 104                 return 0;
 105         }
 106
 107         if (strcmp(var, "receive.denydeletecurrent") == 0) {
 108                 deny_delete_current = parse_deny_action(var, value);
 109                 return 0;
 110         }
 111
 112         if (strcmp(var, "repack.usedeltabaseoffset") == 0) {
 113                 prefer_ofs_delta = git_config_bool(var, value);
 114                 return 0;
 115         }
 116
 117         if (strcmp(var, "receive.updateserverinfo") == 0) {
 118                 auto_update_server_info = git_config_bool(var, value);
 119                 return 0;
 120         }
 121
 122         if (strcmp(var, "receive.autogc") == 0) {
 123                 auto_gc = git_config_bool(var, value);
 124                 return 0;
 125         }
 126
 127         if (strcmp(var, "receive.shallowupdate") == 0) {
 128                 shallow_update = git_config_bool(var, value);
 129                 return 0;
 130         }
 131
 132         return git_default_config(var, value, cb);
 133 }
 134
 135 static void show_ref(const char *path, const unsigned char *sha1)
 136 {
 137         if (ref_is_hidden(path))
 138                 return;
 139
 140         if (sent_capabilities)
 141                 packet_write(1, "%s %s\n", sha1_to_hex(sha1), path);
 142         else
 143                 packet_write(1, "%s %s%c%s%s agent=%s\n",
 144                              sha1_to_hex(sha1), path, 0,
 145                              " report-status delete-refs side-band-64k quiet",
 146                              prefer_ofs_delta ? " ofs-delta" : "",
 147                              git_user_agent_sanitized());
 148         sent_capabilities = 1;
 149 }
 150
 151 static int show_ref_cb(const char *path, const unsigned char *sha1, int flag, void *unused)
 152 {
 153         path = strip_namespace(path);
 154         /*
 155          * Advertise refs outside our current namespace as ".have"
 156          * refs, so that the client can use them to minimize data
 157          * transfer but will otherwise ignore them. This happens to
 158          * cover ".have" that are thrown in by add_one_alternate_ref()
 159          * to mark histories that are complete in our alternates as
 160          * well.
 161          */
 162         if (!path)
 163                 path = ".have";
 164         show_ref(path, sha1);
 165         return 0;
 166 }
 167
 168 static void show_one_alternate_sha1(const unsigned char sha1[20], void *unused)
 169 {
 170         show_ref(".have", sha1);
 171 }
 172
 173 static void collect_one_alternate_ref(const struct ref *ref, void *data)
 174 {
 175         struct sha1_array *sa = data;
 176         sha1_array_append(sa, ref->old_sha1);
 177 }
 178
 179 static void write_head_info(void)
 180 {
 181         struct sha1_array sa = SHA1_ARRAY_INIT;
 182         for_each_alternate_ref(collect_one_alternate_ref, &sa);
 183         sha1_array_for_each_unique(&sa, show_one_alternate_sha1, NULL);
 184         sha1_array_clear(&sa);
 185         for_each_ref(show_ref_cb, NULL);
 186         if (!sent_capabilities)
 187                 show_ref("capabilities^{}", null_sha1);
 188
 189         advertise_shallow_grafts(1);
 190
 191         /* EOF */
 192         packet_flush(1);
 193 }
 194
 195 struct command {
 196         struct command *next;
 197         const char *error_string;
 198         unsigned int skip_update:1,
 199                      did_not_exist:1;
 200         int index;
 201         unsigned char old_sha1[20];
 202         unsigned char new_sha1[20];
 203         char ref_name[FLEX_ARRAY]; /* more */
 204 };
 205
 206 static void rp_error(const char *err, ...) __attribute__((format (printf, 1, 2)));
 207 static void rp_warning(const char *err, ...) __attribute__((format (printf, 1, 2)));
 208
 209 static void report_message(const char *prefix, const char *err, va_list params)
 210 {
 211         int sz = strlen(prefix);
 212         char msg[4096];
 213
 214         strncpy(msg, prefix, sz);
 215         sz += vsnprintf(msg + sz, sizeof(msg) - sz, err, params);
 216         if (sz > (sizeof(msg) - 1))
 217                 sz = sizeof(msg) - 1;
 218         msg[sz++] = '\n';
 219
 220         if (use_sideband)
 221                 send_sideband(1, 2, msg, sz, use_sideband);
 222         else
 223                 xwrite(2, msg, sz);
 224 }
 225
 226 static void rp_warning(const char *err, ...)
 227 {
 228         va_list params;
 229         va_start(params, err);
 230         report_message("warning: ", err, params);
 231         va_end(params);
 232 }
 233
 234 static void rp_error(const char *err, ...)
 235 {
 236         va_list params;
 237         va_start(params, err);
 238         report_message("error: ", err, params);
 239         va_end(params);
 240 }
 241
 242 static int copy_to_sideband(int in, int out, void *arg)
 243 {
 244         char data[128];
 245         while (1) {
 246                 ssize_t sz = xread(in, data, sizeof(data));
 247                 if (sz <= 0)
 248                         break;
 249                 send_sideband(1, 2, data, sz, use_sideband);
 250         }
 251         close(in);
 252         return 0;
 253 }
 254
 255 typedef int (*feed_fn)(void *, const char **, size_t *);
 256 static int run_and_feed_hook(const char *hook_name, feed_fn feed, void *feed_state)
 257 {
 258         struct child_process proc = CHILD_PROCESS_INIT;
 259         struct async muxer;
 260         const char *argv[2];
 261         int code;
 262
 263         argv[0] = find_hook(hook_name);
 264         if (!argv[0])
 265                 return 0;
 266
 267         argv[1] = NULL;
 268
 269         proc.argv = argv;
 270         proc.in = -1;
 271         proc.stdout_to_stderr = 1;
 272
 273         if (use_sideband) {
 274                 memset(&muxer, 0, sizeof(muxer));
 275                 muxer.proc = copy_to_sideband;
 276                 muxer.in = -1;
 277                 code = start_async(&muxer);
 278                 if (code)
 279                         return code;
 280                 proc.err = muxer.in;
 281         }
 282
 283         code = start_command(&proc);
 284         if (code) {
 285                 if (use_sideband)
 286                         finish_async(&muxer);
 287                 return code;
 288         }
 289
 290         while (1) {
 291                 const char *buf;
 292                 size_t n;
 293                 if (feed(feed_state, &buf, &n))
 294                         break;
 295                 if (write_in_full(proc.in, buf, n) != n)
 296                         break;
 297         }
 298         close(proc.in);
 299         if (use_sideband)
 300                 finish_async(&muxer);
 301         return finish_command(&proc);
 302 }
 303
 304 struct receive_hook_feed_state {
 305         struct command *cmd;
 306         int skip_broken;
 307         struct strbuf buf;
 308 };
 309
 310 static int feed_receive_hook(void *state_, const char **bufp, size_t *sizep)
 311 {
 312         struct receive_hook_feed_state *state = state_;
 313         struct command *cmd = state->cmd;
 314
 315         while (cmd &&
 316                state->skip_broken && (cmd->error_string || cmd->did_not_exist))
 317                 cmd = cmd->next;
 318         if (!cmd)
 319                 return -1; /* EOF */
 320         strbuf_reset(&state->buf);
 321         strbuf_addf(&state->buf, "%s %s %s\n",
 322                     sha1_to_hex(cmd->old_sha1), sha1_to_hex(cmd->new_sha1),
 323                     cmd->ref_name);
 324         state->cmd = cmd->next;
 325         if (bufp) {
 326                 *bufp = state->buf.buf;
 327                 *sizep = state->buf.len;
 328         }
 329         return 0;
 330 }
 331
 332 static int run_receive_hook(struct command *commands, const char *hook_name,
 333                             int skip_broken)
 334 {
 335         struct receive_hook_feed_state state;
 336         int status;
 337
 338         strbuf_init(&state.buf, 0);
 339         state.cmd = commands;
 340         state.skip_broken = skip_broken;
 341         if (feed_receive_hook(&state, NULL, NULL))
 342                 return 0;
 343         state.cmd = commands;
 344         status = run_and_feed_hook(hook_name, feed_receive_hook, &state);
 345         strbuf_release(&state.buf);
 346         return status;
 347 }
 348
 349 static int run_update_hook(struct command *cmd)
 350 {
 351         const char *argv[5];
 352         struct child_process proc = CHILD_PROCESS_INIT;
 353         int code;
 354
 355         argv[0] = find_hook("update");
 356         if (!argv[0])
 357                 return 0;
 358
 359         argv[1] = cmd->ref_name;
 360         argv[2] = sha1_to_hex(cmd->old_sha1);
 361         argv[3] = sha1_to_hex(cmd->new_sha1);
 362         argv[4] = NULL;
 363
 364         proc.no_stdin = 1;
 365         proc.stdout_to_stderr = 1;
 366         proc.err = use_sideband ? -1 : 0;
 367         proc.argv = argv;
 368
 369         code = start_command(&proc);
 370         if (code)
 371                 return code;
 372         if (use_sideband)
 373                 copy_to_sideband(proc.err, -1, NULL);
 374         return finish_command(&proc);
 375 }
 376
 377 static int is_ref_checked_out(const char *ref)
 378 {
 379         if (is_bare_repository())
 380                 return 0;
 381
 382         if (!head_name)
 383                 return 0;
 384         return !strcmp(head_name, ref);
 385 }
 386
 387 static char *refuse_unconfigured_deny_msg[] = {
 388         "By default, updating the current branch in a non-bare repository",
 389         "is denied, because it will make the index and work tree inconsistent",
 390         "with what you pushed, and will require 'git reset --hard' to match",
 391         "the work tree to HEAD.",
 392         "",
 393         "You can set 'receive.denyCurrentBranch' configuration variable to",
 394         "'ignore' or 'warn' in the remote repository to allow pushing into",
 395         "its current branch; however, this is not recommended unless you",
 396         "arranged to update its work tree to match what you pushed in some",
 397         "other way.",
 398         "",
 399         "To squelch this message and still keep the default behaviour, set",
 400         "'receive.denyCurrentBranch' configuration variable to 'refuse'."
 401 };
 402
 403 static void refuse_unconfigured_deny(void)
 404 {
 405         int i;
 406         for (i = 0; i < ARRAY_SIZE(refuse_unconfigured_deny_msg); i++)
 407                 rp_error("%s", refuse_unconfigured_deny_msg[i]);
 408 }
 409
 410 static char *refuse_unconfigured_deny_delete_current_msg[] = {
 411         "By default, deleting the current branch is denied, because the next",
 412         "'git clone' won't result in any file checked out, causing confusion.",
 413         "",
 414         "You can set 'receive.denyDeleteCurrent' configuration variable to",
 415         "'warn' or 'ignore' in the remote repository to allow deleting the",
 416         "current branch, with or without a warning message.",
 417         "",
 418         "To squelch this message, you can set it to 'refuse'."
 419 };
 420
 421 static void refuse_unconfigured_deny_delete_current(void)
 422 {
 423         int i;
 424         for (i = 0;
 425              i < ARRAY_SIZE(refuse_unconfigured_deny_delete_current_msg);
 426              i++)
 427                 rp_error("%s", refuse_unconfigured_deny_delete_current_msg[i]);
 428 }
 429
 430 static int command_singleton_iterator(void *cb_data, unsigned char sha1[20]);
 431 static int update_shallow_ref(struct command *cmd, struct shallow_info *si)
 432 {
 433         static struct lock_file shallow_lock;
 434         struct sha1_array extra = SHA1_ARRAY_INIT;
 435         const char *alt_file;
 436         uint32_t mask = 1 << (cmd->index % 32);
 437         int i;
 438
 439         trace_printf_key(&trace_shallow,
 440                          "shallow: update_shallow_ref %s\n", cmd->ref_name);
 441         for (i = 0; i < si->shallow->nr; i++)
 442                 if (si->used_shallow[i] &&
 443                     (si->used_shallow[i][cmd->index / 32] & mask) &&
 444                     !delayed_reachability_test(si, i))
 445                         sha1_array_append(&extra, si->shallow->sha1[i]);
 446
 447         setup_alternate_shallow(&shallow_lock, &alt_file, &extra);
 448         if (check_shallow_connected(command_singleton_iterator,
 449                                     0, cmd, alt_file)) {
 450                 rollback_lock_file(&shallow_lock);
 451                 sha1_array_clear(&extra);
 452                 return -1;
 453         }
 454
 455         commit_lock_file(&shallow_lock);
 456
 457         /*
 458          * Make sure setup_alternate_shallow() for the next ref does
 459          * not lose these new roots..
 460          */
 461         for (i = 0; i < extra.nr; i++)
 462                 register_shallow(extra.sha1[i]);
 463
 464         si->shallow_ref[cmd->index] = 0;
 465         sha1_array_clear(&extra);
 466         return 0;
 467 }
 468
 469 static const char *update(struct command *cmd, struct shallow_info *si)
 470 {
 471         const char *name = cmd->ref_name;
 472         struct strbuf namespaced_name_buf = STRBUF_INIT;
 473         const char *namespaced_name;
 474         unsigned char *old_sha1 = cmd->old_sha1;
 475         unsigned char *new_sha1 = cmd->new_sha1;
 476
 477         /* only refs/... are allowed */
 478         if (!starts_with(name, "refs/") || check_refname_format(name + 5, 0)) {
 479                 rp_error("refusing to create funny ref '%s' remotely", name);
 480                 return "funny refname";
 481         }
 482
 483         strbuf_addf(&namespaced_name_buf, "%s%s", get_git_namespace(), name);
 484         namespaced_name = strbuf_detach(&namespaced_name_buf, NULL);
 485
 486         if (is_ref_checked_out(namespaced_name)) {
 487                 switch (deny_current_branch) {
 488                 case DENY_IGNORE:
 489                         break;
 490                 case DENY_WARN:
 491                         rp_warning("updating the current branch");
 492                         break;
 493                 case DENY_REFUSE:
 494                 case DENY_UNCONFIGURED:
 495                         rp_error("refusing to update checked out branch: %s", name);
 496                         if (deny_current_branch == DENY_UNCONFIGURED)
 497                                 refuse_unconfigured_deny();
 498                         return "branch is currently checked out";
 499                 }
 500         }
 501
 502         if (!is_null_sha1(new_sha1) && !has_sha1_file(new_sha1)) {
 503                 error("unpack should have generated %s, "
 504                       "but I can't find it!", sha1_to_hex(new_sha1));
 505                 return "bad pack";
 506         }
 507
 508         if (!is_null_sha1(old_sha1) && is_null_sha1(new_sha1)) {
 509                 if (deny_deletes && starts_with(name, "refs/heads/")) {
 510                         rp_error("denying ref deletion for %s", name);
 511                         return "deletion prohibited";
 512                 }
 513
 514                 if (!strcmp(namespaced_name, head_name)) {
 515                         switch (deny_delete_current) {
 516                         case DENY_IGNORE:
 517                                 break;
 518                         case DENY_WARN:
 519                                 rp_warning("deleting the current branch");
 520                                 break;
 521                         case DENY_REFUSE:
 522                         case DENY_UNCONFIGURED:
 523                                 if (deny_delete_current == DENY_UNCONFIGURED)
 524                                         refuse_unconfigured_deny_delete_current();
 525                                 rp_error("refusing to delete the current branch: %s", name);
 526                                 return "deletion of the current branch prohibited";
 527                         }
 528                 }
 529         }
 530
 531         if (deny_non_fast_forwards && !is_null_sha1(new_sha1) &&
 532             !is_null_sha1(old_sha1) &&
 533             starts_with(name, "refs/heads/")) {
 534                 struct object *old_object, *new_object;
 535                 struct commit *old_commit, *new_commit;
 536
 537                 old_object = parse_object(old_sha1);
 538                 new_object = parse_object(new_sha1);
 539
 540                 if (!old_object || !new_object ||
 541                     old_object->type != OBJ_COMMIT ||
 542                     new_object->type != OBJ_COMMIT) {
 543                         error("bad sha1 objects for %s", name);
 544                         return "bad ref";
 545                 }
 546                 old_commit = (struct commit *)old_object;
 547                 new_commit = (struct commit *)new_object;
 548                 if (!in_merge_bases(old_commit, new_commit)) {
 549                         rp_error("denying non-fast-forward %s"
 550                                  " (you should pull first)", name);
 551                         return "non-fast-forward";
 552                 }
 553         }
 554         if (run_update_hook(cmd)) {
 555                 rp_error("hook declined to update %s", name);
 556                 return "hook declined";
 557         }
 558
 559         if (is_null_sha1(new_sha1)) {
 560                 if (!parse_object(old_sha1)) {
 561                         old_sha1 = NULL;
 562                         if (ref_exists(name)) {
 563                                 rp_warning("Allowing deletion of corrupt ref.");
 564                         } else {
 565                                 rp_warning("Deleting a non-existent ref.");
 566                                 cmd->did_not_exist = 1;
 567                         }
 568                 }
 569                 if (delete_ref(namespaced_name, old_sha1, 0)) {
 570                         rp_error("failed to delete %s", name);
 571                         return "failed to delete";
 572                 }
 573                 return NULL; /* good */
 574         }
 575         else {
 576                 struct strbuf err = STRBUF_INIT;
 577                 struct ref_transaction *transaction;
 578
 579                 if (shallow_update && si->shallow_ref[cmd->index] &&
 580                     update_shallow_ref(cmd, si))
 581                         return "shallow error";
 582
 583                 transaction = ref_transaction_begin(&err);
 584                 if (!transaction ||
 585                     ref_transaction_update(transaction, namespaced_name,
 586                                            new_sha1, old_sha1, 0, 1, &err) ||
 587                     ref_transaction_commit(transaction, "push", &err)) {
 588                         ref_transaction_free(transaction);
 589
 590                         rp_error("%s", err.buf);
 591                         strbuf_release(&err);
 592                         return "failed to update ref";
 593                 }
 594
 595                 ref_transaction_free(transaction);
 596                 strbuf_release(&err);
 597                 return NULL; /* good */
 598         }
 599 }
 600
 601 static void run_update_post_hook(struct command *commands)
 602 {
 603         struct command *cmd;
 604         int argc;
 605         const char **argv;
 606         struct child_process proc = CHILD_PROCESS_INIT;
 607         char *hook;
 608
 609         hook = find_hook("post-update");
 610         for (argc = 0, cmd = commands; cmd; cmd = cmd->next) {
 611                 if (cmd->error_string || cmd->did_not_exist)
 612                         continue;
 613                 argc++;
 614         }
 615         if (!argc || !hook)
 616                 return;
 617
 618         argv = xmalloc(sizeof(*argv) * (2 + argc));
 619         argv[0] = hook;
 620
 621         for (argc = 1, cmd = commands; cmd; cmd = cmd->next) {
 622                 if (cmd->error_string || cmd->did_not_exist)
 623                         continue;
 624                 argv[argc] = xstrdup(cmd->ref_name);
 625                 argc++;
 626         }
 627         argv[argc] = NULL;
 628
 629         proc.no_stdin = 1;
 630         proc.stdout_to_stderr = 1;
 631         proc.err = use_sideband ? -1 : 0;
 632         proc.argv = argv;
 633
 634         if (!start_command(&proc)) {
 635                 if (use_sideband)
 636                         copy_to_sideband(proc.err, -1, NULL);
 637                 finish_command(&proc);
 638         }
 639 }
 640
 641 static void check_aliased_update(struct command *cmd, struct string_list *list)
 642 {
 643         struct strbuf buf = STRBUF_INIT;
 644         const char *dst_name;
 645         struct string_list_item *item;
 646         struct command *dst_cmd;
 647         unsigned char sha1[20];
 648         char cmd_oldh[41], cmd_newh[41], dst_oldh[41], dst_newh[41];
 649         int flag;
 650
 651         strbuf_addf(&buf, "%s%s", get_git_namespace(), cmd->ref_name);
 652         dst_name = resolve_ref_unsafe(buf.buf, sha1, 0, &flag);
 653         strbuf_release(&buf);
 654
 655         if (!(flag & REF_ISSYMREF))
 656                 return;
 657
 658         dst_name = strip_namespace(dst_name);
 659         if (!dst_name) {
 660                 rp_error("refusing update to broken symref '%s'", cmd->ref_name);
 661                 cmd->skip_update = 1;
 662                 cmd->error_string = "broken symref";
 663                 return;
 664         }
 665
 666         if ((item = string_list_lookup(list, dst_name)) == NULL)
 667                 return;
 668
 669         cmd->skip_update = 1;
 670
 671         dst_cmd = (struct command *) item->util;
 672
 673         if (!hashcmp(cmd->old_sha1, dst_cmd->old_sha1) &&
 674             !hashcmp(cmd->new_sha1, dst_cmd->new_sha1))
 675                 return;
 676
 677         dst_cmd->skip_update = 1;
 678
 679         strcpy(cmd_oldh, find_unique_abbrev(cmd->old_sha1, DEFAULT_ABBREV));
 680         strcpy(cmd_newh, find_unique_abbrev(cmd->new_sha1, DEFAULT_ABBREV));
 681         strcpy(dst_oldh, find_unique_abbrev(dst_cmd->old_sha1, DEFAULT_ABBREV));
 682         strcpy(dst_newh, find_unique_abbrev(dst_cmd->new_sha1, DEFAULT_ABBREV));
 683         rp_error("refusing inconsistent update between symref '%s' (%s..%s) and"
 684                  " its target '%s' (%s..%s)",
 685                  cmd->ref_name, cmd_oldh, cmd_newh,
 686                  dst_cmd->ref_name, dst_oldh, dst_newh);
 687
 688         cmd->error_string = dst_cmd->error_string =
 689                 "inconsistent aliased update";
 690 }
 691
 692 static void check_aliased_updates(struct command *commands)
 693 {
 694         struct command *cmd;
 695         struct string_list ref_list = STRING_LIST_INIT_NODUP;
 696
 697         for (cmd = commands; cmd; cmd = cmd->next) {
 698                 struct string_list_item *item =
 699                         string_list_append(&ref_list, cmd->ref_name);
 700                 item->util = (void *)cmd;
 701         }
 702         sort_string_list(&ref_list);
 703
 704         for (cmd = commands; cmd; cmd = cmd->next) {
 705                 if (!cmd->error_string)
 706                         check_aliased_update(cmd, &ref_list);
 707         }
 708
 709         string_list_clear(&ref_list, 0);
 710 }
 711
 712 static int command_singleton_iterator(void *cb_data, unsigned char sha1[20])
 713 {
 714         struct command **cmd_list = cb_data;
 715         struct command *cmd = *cmd_list;
 716
 717         if (!cmd || is_null_sha1(cmd->new_sha1))
 718                 return -1; /* end of list */
 719         *cmd_list = NULL; /* this returns only one */
 720         hashcpy(sha1, cmd->new_sha1);
 721         return 0;
 722 }
 723
 724 static void set_connectivity_errors(struct command *commands,
 725                                     struct shallow_info *si)
 726 {
 727         struct command *cmd;
 728
 729         for (cmd = commands; cmd; cmd = cmd->next) {
 730                 struct command *singleton = cmd;
 731                 if (shallow_update && si->shallow_ref[cmd->index])
 732                         /* to be checked in update_shallow_ref() */
 733                         continue;
 734                 if (!check_everything_connected(command_singleton_iterator,
 735                                                 0, &singleton))
 736                         continue;
 737                 cmd->error_string = "missing necessary objects";
 738         }
 739 }
 740
 741 struct iterate_data {
 742         struct command *cmds;
 743         struct shallow_info *si;
 744 };
 745
 746 static int iterate_receive_command_list(void *cb_data, unsigned char sha1[20])
 747 {
 748         struct iterate_data *data = cb_data;
 749         struct command **cmd_list = &data->cmds;
 750         struct command *cmd = *cmd_list;
 751
 752         for (; cmd; cmd = cmd->next) {
 753                 if (shallow_update && data->si->shallow_ref[cmd->index])
 754                         /* to be checked in update_shallow_ref() */
 755                         continue;
 756                 if (!is_null_sha1(cmd->new_sha1) && !cmd->skip_update) {
 757                         hashcpy(sha1, cmd->new_sha1);
 758                         *cmd_list = cmd->next;
 759                         return 0;
 760                 }
 761         }
 762         *cmd_list = NULL;
 763         return -1; /* end of list */
 764 }
 765
 766 static void reject_updates_to_hidden(struct command *commands)
 767 {
 768         struct command *cmd;
 769
 770         for (cmd = commands; cmd; cmd = cmd->next) {
 771                 if (cmd->error_string || !ref_is_hidden(cmd->ref_name))
 772                         continue;
 773                 if (is_null_sha1(cmd->new_sha1))
 774                         cmd->error_string = "deny deleting a hidden ref";
 775                 else
 776                         cmd->error_string = "deny updating a hidden ref";
 777         }
 778 }
 779
 780 static void execute_commands(struct command *commands,
 781                              const char *unpacker_error,
 782                              struct shallow_info *si)
 783 {
 784         int checked_connectivity;
 785         struct command *cmd;
 786         unsigned char sha1[20];
 787         struct iterate_data data;
 788
 789         if (unpacker_error) {
 790                 for (cmd = commands; cmd; cmd = cmd->next)
 791                         cmd->error_string = "unpacker error";
 792                 return;
 793         }
 794
 795         data.cmds = commands;
 796         data.si = si;
 797         if (check_everything_connected(iterate_receive_command_list, 0, &data))
 798                 set_connectivity_errors(commands, si);
 799
 800         reject_updates_to_hidden(commands);
 801
 802         if (run_receive_hook(commands, "pre-receive", 0)) {
 803                 for (cmd = commands; cmd; cmd = cmd->next) {
 804                         if (!cmd->error_string)
 805                                 cmd->error_string = "pre-receive hook declined";
 806                 }
 807                 return;
 808         }
 809
 810         check_aliased_updates(commands);
 811
 812         free(head_name_to_free);
 813         head_name = head_name_to_free = resolve_refdup("HEAD", sha1, 0, NULL);
 814
 815         checked_connectivity = 1;
 816         for (cmd = commands; cmd; cmd = cmd->next) {
 817                 if (cmd->error_string)
 818                         continue;
 819
 820                 if (cmd->skip_update)
 821                         continue;
 822
 823                 cmd->error_string = update(cmd, si);
 824                 if (shallow_update && !cmd->error_string &&
 825                     si->shallow_ref[cmd->index]) {
 826                         error("BUG: connectivity check has not been run on ref %s",
 827                               cmd->ref_name);
 828                         checked_connectivity = 0;
 829                 }
 830         }
 831
 832         if (shallow_update && !checked_connectivity)
 833                 error("BUG: run 'git fsck' for safety.\n"
 834                       "If there are errors, try to remove "
 835                       "the reported refs above");
 836 }
 837
 838 static struct command *read_head_info(struct sha1_array *shallow)
 839 {
 840         struct command *commands = NULL;
 841         struct command **p = &commands;
 842         for (;;) {
 843                 char *line;
 844                 unsigned char old_sha1[20], new_sha1[20];
 845                 struct command *cmd;
 846                 char *refname;
 847                 int len, reflen;
 848
 849                 line = packet_read_line(0, &len);
 850                 if (!line)
 851                         break;
 852
 853                 if (len == 48 && starts_with(line, "shallow ")) {
 854                         if (get_sha1_hex(line + 8, old_sha1))
 855                                 die("protocol error: expected shallow sha, got '%s'", line + 8);
 856                         sha1_array_append(shallow, old_sha1);
 857                         continue;
 858                 }
 859
 860                 if (len < 83 ||
 861                     line[40] != ' ' ||
 862                     line[81] != ' ' ||
 863                     get_sha1_hex(line, old_sha1) ||
 864                     get_sha1_hex(line + 41, new_sha1))
 865                         die("protocol error: expected old/new/ref, got '%s'",
 866                             line);
 867
 868                 refname = line + 82;
 869                 reflen = strlen(refname);
 870                 if (reflen + 82 < len) {
 871                         const char *feature_list = refname + reflen + 1;
 872                         if (parse_feature_request(feature_list, "report-status"))
 873                                 report_status = 1;
 874                         if (parse_feature_request(feature_list, "side-band-64k"))
 875                                 use_sideband = LARGE_PACKET_MAX;
 876                         if (parse_feature_request(feature_list, "quiet"))
 877                                 quiet = 1;
 878                 }
 879                 cmd = xcalloc(1, sizeof(struct command) + len - 80);
 880                 hashcpy(cmd->old_sha1, old_sha1);
 881                 hashcpy(cmd->new_sha1, new_sha1);
 882                 memcpy(cmd->ref_name, line + 82, len - 81);
 883                 *p = cmd;
 884                 p = &cmd->next;
 885         }
 886         return commands;
 887 }
 888
 889 static const char *parse_pack_header(struct pack_header *hdr)
 890 {
 891         switch (read_pack_header(0, hdr)) {
 892         case PH_ERROR_EOF:
 893                 return "eof before pack header was fully read";
 894
 895         case PH_ERROR_PACK_SIGNATURE:
 896                 return "protocol error (pack signature mismatch detected)";
 897
 898         case PH_ERROR_PROTOCOL:
 899                 return "protocol error (pack version unsupported)";
 900
 901         default:
 902                 return "unknown error in parse_pack_header";
 903
 904         case 0:
 905                 return NULL;
 906         }
 907 }
 908
 909 static const char *pack_lockfile;
 910
 911 static const char *unpack(int err_fd, struct shallow_info *si)
 912 {
 913         struct pack_header hdr;
 914         struct argv_array av = ARGV_ARRAY_INIT;
 915         const char *hdr_err;
 916         int status;
 917         char hdr_arg[38];
 918         struct child_process child = CHILD_PROCESS_INIT;
 919         int fsck_objects = (receive_fsck_objects >= 0
 920                             ? receive_fsck_objects
 921                             : transfer_fsck_objects >= 0
 922                             ? transfer_fsck_objects
 923                             : 0);
 924
 925         hdr_err = parse_pack_header(&hdr);
 926         if (hdr_err) {
 927                 if (err_fd > 0)
 928                         close(err_fd);
 929                 return hdr_err;
 930         }
 931         snprintf(hdr_arg, sizeof(hdr_arg),
 932                         "--pack_header=%"PRIu32",%"PRIu32,
 933                         ntohl(hdr.hdr_version), ntohl(hdr.hdr_entries));
 934
 935         if (si->nr_ours || si->nr_theirs) {
 936                 alt_shallow_file = setup_temporary_shallow(si->shallow);
 937                 argv_array_pushl(&av, "--shallow-file", alt_shallow_file, NULL);
 938         }
 939
 940         if (ntohl(hdr.hdr_entries) < unpack_limit) {
 941                 argv_array_pushl(&av, "unpack-objects", hdr_arg, NULL);
 942                 if (quiet)
 943                         argv_array_push(&av, "-q");
 944                 if (fsck_objects)
 945                         argv_array_push(&av, "--strict");
 946                 child.argv = av.argv;
 947                 child.no_stdout = 1;
 948                 child.err = err_fd;
 949                 child.git_cmd = 1;
 950                 status = run_command(&child);
 951                 if (status)
 952                         return "unpack-objects abnormal exit";
 953         } else {
 954                 int s;
 955                 char keep_arg[256];
 956
 957                 s = sprintf(keep_arg, "--keep=receive-pack %"PRIuMAX" on ", (uintmax_t) getpid());
 958                 if (gethostname(keep_arg + s, sizeof(keep_arg) - s))
 959                         strcpy(keep_arg + s, "localhost");
 960
 961                 argv_array_pushl(&av, "index-pack",
 962                                  "--stdin", hdr_arg, keep_arg, NULL);
 963                 if (fsck_objects)
 964                         argv_array_push(&av, "--strict");
 965                 if (fix_thin)
 966                         argv_array_push(&av, "--fix-thin");
 967                 child.argv = av.argv;
 968                 child.out = -1;
 969                 child.err = err_fd;
 970                 child.git_cmd = 1;
 971                 status = start_command(&child);
 972                 if (status)
 973                         return "index-pack fork failed";
 974                 pack_lockfile = index_pack_lockfile(child.out);
 975                 close(child.out);
 976                 status = finish_command(&child);
 977                 if (status)
 978                         return "index-pack abnormal exit";
 979                 reprepare_packed_git();
 980         }
 981         return NULL;
 982 }
 983
 984 static const char *unpack_with_sideband(struct shallow_info *si)
 985 {
 986         struct async muxer;
 987         const char *ret;
 988
 989         if (!use_sideband)
 990                 return unpack(0, si);
 991
 992         memset(&muxer, 0, sizeof(muxer));
 993         muxer.proc = copy_to_sideband;
 994         muxer.in = -1;
 995         if (start_async(&muxer))
 996                 return NULL;
 997
 998         ret = unpack(muxer.in, si);
 999
1000         finish_async(&muxer);
1001         return ret;
1002 }
1003
1004 static void prepare_shallow_update(struct command *commands,
1005                                    struct shallow_info *si)
1006 {
1007         int i, j, k, bitmap_size = (si->ref->nr + 31) / 32;
1008
1009         si->used_shallow = xmalloc(sizeof(*si->used_shallow) *
1010                                    si->shallow->nr);
1011         assign_shallow_commits_to_refs(si, si->used_shallow, NULL);
1012
1013         si->need_reachability_test =
1014                 xcalloc(si->shallow->nr, sizeof(*si->need_reachability_test));
1015         si->reachable =
1016                 xcalloc(si->shallow->nr, sizeof(*si->reachable));
1017         si->shallow_ref = xcalloc(si->ref->nr, sizeof(*si->shallow_ref));
1018
1019         for (i = 0; i < si->nr_ours; i++)
1020                 si->need_reachability_test[si->ours[i]] = 1;
1021
1022         for (i = 0; i < si->shallow->nr; i++) {
1023                 if (!si->used_shallow[i])
1024                         continue;
1025                 for (j = 0; j < bitmap_size; j++) {
1026                         if (!si->used_shallow[i][j])
1027                                 continue;
1028                         si->need_reachability_test[i]++;
1029                         for (k = 0; k < 32; k++)
1030                                 if (si->used_shallow[i][j] & (1 << k))
1031                                         si->shallow_ref[j * 32 + k]++;
1032                 }
1033
1034                 /*
1035                  * true for those associated with some refs and belong
1036                  * in "ours" list aka "step 7 not done yet"
1037                  */
1038                 si->need_reachability_test[i] =
1039                         si->need_reachability_test[i] > 1;
1040         }
1041
1042         /*
1043          * keep hooks happy by forcing a temporary shallow file via
1044          * env variable because we can't add --shallow-file to every
1045          * command. check_everything_connected() will be done with
1046          * true .git/shallow though.
1047          */
1048         setenv(GIT_SHALLOW_FILE_ENVIRONMENT, alt_shallow_file, 1);
1049 }
1050
1051 static void update_shallow_info(struct command *commands,
1052                                 struct shallow_info *si,
1053                                 struct sha1_array *ref)
1054 {
1055         struct command *cmd;
1056         int *ref_status;
1057         remove_nonexistent_theirs_shallow(si);
1058         if (!si->nr_ours && !si->nr_theirs) {
1059                 shallow_update = 0;
1060                 return;
1061         }
1062
1063         for (cmd = commands; cmd; cmd = cmd->next) {
1064                 if (is_null_sha1(cmd->new_sha1))
1065                         continue;
1066                 sha1_array_append(ref, cmd->new_sha1);
1067                 cmd->index = ref->nr - 1;
1068         }
1069         si->ref = ref;
1070
1071         if (shallow_update) {
1072                 prepare_shallow_update(commands, si);
1073                 return;
1074         }
1075
1076         ref_status = xmalloc(sizeof(*ref_status) * ref->nr);
1077         assign_shallow_commits_to_refs(si, NULL, ref_status);
1078         for (cmd = commands; cmd; cmd = cmd->next) {
1079                 if (is_null_sha1(cmd->new_sha1))
1080                         continue;
1081                 if (ref_status[cmd->index]) {
1082                         cmd->error_string = "shallow update not allowed";
1083                         cmd->skip_update = 1;
1084                 }
1085         }
1086         free(ref_status);
1087 }
1088
1089 static void report(struct command *commands, const char *unpack_status)
1090 {
1091         struct command *cmd;
1092         struct strbuf buf = STRBUF_INIT;
1093
1094         packet_buf_write(&buf, "unpack %s\n",
1095                          unpack_status ? unpack_status : "ok");
1096         for (cmd = commands; cmd; cmd = cmd->next) {
1097                 if (!cmd->error_string)
1098                         packet_buf_write(&buf, "ok %s\n",
1099                                          cmd->ref_name);
1100                 else
1101                         packet_buf_write(&buf, "ng %s %s\n",
1102                                          cmd->ref_name, cmd->error_string);
1103         }
1104         packet_buf_flush(&buf);
1105
1106         if (use_sideband)
1107                 send_sideband(1, 1, buf.buf, buf.len, use_sideband);
1108         else
1109                 write_or_die(1, buf.buf, buf.len);
1110         strbuf_release(&buf);
1111 }
1112
1113 static int delete_only(struct command *commands)
1114 {
1115         struct command *cmd;
1116         for (cmd = commands; cmd; cmd = cmd->next) {
1117                 if (!is_null_sha1(cmd->new_sha1))
1118                         return 0;
1119         }
1120         return 1;
1121 }
1122
1123 int cmd_receive_pack(int argc, const char **argv, const char *prefix)
1124 {
1125         int advertise_refs = 0;
1126         int stateless_rpc = 0;
1127         int i;
1128         const char *dir = NULL;
1129         struct command *commands;
1130         struct sha1_array shallow = SHA1_ARRAY_INIT;
1131         struct sha1_array ref = SHA1_ARRAY_INIT;
1132         struct shallow_info si;
1133
1134         packet_trace_identity("receive-pack");
1135
1136         argv++;
1137         for (i = 1; i < argc; i++) {
1138                 const char *arg = *argv++;
1139
1140                 if (*arg == '-') {
1141                         if (!strcmp(arg, "--quiet")) {
1142                                 quiet = 1;
1143                                 continue;
1144                         }
1145
1146                         if (!strcmp(arg, "--advertise-refs")) {
1147                                 advertise_refs = 1;
1148                                 continue;
1149                         }
1150                         if (!strcmp(arg, "--stateless-rpc")) {
1151                                 stateless_rpc = 1;
1152                                 continue;
1153                         }
1154                         if (!strcmp(arg, "--reject-thin-pack-for-testing")) {
1155                                 fix_thin = 0;
1156                                 continue;
1157                         }
1158
1159                         usage(receive_pack_usage);
1160                 }
1161                 if (dir)
1162                         usage(receive_pack_usage);
1163                 dir = arg;
1164         }
1165         if (!dir)
1166                 usage(receive_pack_usage);
1167
1168         setup_path();
1169
1170         if (!enter_repo(dir, 0))
1171                 die("'%s' does not appear to be a git repository", dir);
1172
1173         git_config(receive_pack_config, NULL);
1174
1175         if (0 <= transfer_unpack_limit)
1176                 unpack_limit = transfer_unpack_limit;
1177         else if (0 <= receive_unpack_limit)
1178                 unpack_limit = receive_unpack_limit;
1179
1180         if (advertise_refs || !stateless_rpc) {
1181                 write_head_info();
1182         }
1183         if (advertise_refs)
1184                 return 0;
1185
1186         if ((commands = read_head_info(&shallow)) != NULL) {
1187                 const char *unpack_status = NULL;
1188
1189                 prepare_shallow_info(&si, &shallow);
1190                 if (!si.nr_ours && !si.nr_theirs)
1191                         shallow_update = 0;
1192                 if (!delete_only(commands)) {
1193                         unpack_status = unpack_with_sideband(&si);
1194                         update_shallow_info(commands, &si, &ref);
1195                 }
1196                 execute_commands(commands, unpack_status, &si);
1197                 if (pack_lockfile)
1198                         unlink_or_warn(pack_lockfile);
1199                 if (report_status)
1200                         report(commands, unpack_status);
1201                 run_receive_hook(commands, "post-receive", 1);
1202                 run_update_post_hook(commands);
1203                 if (auto_gc) {
1204                         const char *argv_gc_auto[] = {
1205                                 "gc", "--auto", "--quiet", NULL,
1206                         };
1207                         int opt = RUN_GIT_CMD | RUN_COMMAND_STDOUT_TO_STDERR;
1208                         run_command_v_opt(argv_gc_auto, opt);
1209                 }
1210                 if (auto_update_server_info)
1211                         update_server_info(0);
1212                 clear_shallow_info(&si);
1213         }
1214         if (use_sideband)
1215                 packet_flush(1);
1216         sha1_array_clear(&shallow);
1217         sha1_array_clear(&ref);
1218         return 0;
1219 }