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;
 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         memset(&proc, 0, sizeof(proc));
 270         proc.argv = argv;
 271         proc.in = -1;
 272         proc.stdout_to_stderr = 1;
 273
 274         if (use_sideband) {
 275                 memset(&muxer, 0, sizeof(muxer));
 276                 muxer.proc = copy_to_sideband;
 277                 muxer.in = -1;
 278                 code = start_async(&muxer);
 279                 if (code)
 280                         return code;
 281                 proc.err = muxer.in;
 282         }
 283
 284         code = start_command(&proc);
 285         if (code) {
 286                 if (use_sideband)
 287                         finish_async(&muxer);
 288                 return code;
 289         }
 290
 291         while (1) {
 292                 const char *buf;
 293                 size_t n;
 294                 if (feed(feed_state, &buf, &n))
 295                         break;
 296                 if (write_in_full(proc.in, buf, n) != n)
 297                         break;
 298         }
 299         close(proc.in);
 300         if (use_sideband)
 301                 finish_async(&muxer);
 302         return finish_command(&proc);
 303 }
 304
 305 struct receive_hook_feed_state {
 306         struct command *cmd;
 307         int skip_broken;
 308         struct strbuf buf;
 309 };
 310
 311 static int feed_receive_hook(void *state_, const char **bufp, size_t *sizep)
 312 {
 313         struct receive_hook_feed_state *state = state_;
 314         struct command *cmd = state->cmd;
 315
 316         while (cmd &&
 317                state->skip_broken && (cmd->error_string || cmd->did_not_exist))
 318                 cmd = cmd->next;
 319         if (!cmd)
 320                 return -1; /* EOF */
 321         strbuf_reset(&state->buf);
 322         strbuf_addf(&state->buf, "%s %s %s\n",
 323                     sha1_to_hex(cmd->old_sha1), sha1_to_hex(cmd->new_sha1),
 324                     cmd->ref_name);
 325         state->cmd = cmd->next;
 326         if (bufp) {
 327                 *bufp = state->buf.buf;
 328                 *sizep = state->buf.len;
 329         }
 330         return 0;
 331 }
 332
 333 static int run_receive_hook(struct command *commands, const char *hook_name,
 334                             int skip_broken)
 335 {
 336         struct receive_hook_feed_state state;
 337         int status;
 338
 339         strbuf_init(&state.buf, 0);
 340         state.cmd = commands;
 341         state.skip_broken = skip_broken;
 342         if (feed_receive_hook(&state, NULL, NULL))
 343                 return 0;
 344         state.cmd = commands;
 345         status = run_and_feed_hook(hook_name, feed_receive_hook, &state);
 346         strbuf_release(&state.buf);
 347         return status;
 348 }
 349
 350 static int run_update_hook(struct command *cmd)
 351 {
 352         const char *argv[5];
 353         struct child_process proc;
 354         int code;
 355
 356         argv[0] = find_hook("update");
 357         if (!argv[0])
 358                 return 0;
 359
 360         argv[1] = cmd->ref_name;
 361         argv[2] = sha1_to_hex(cmd->old_sha1);
 362         argv[3] = sha1_to_hex(cmd->new_sha1);
 363         argv[4] = NULL;
 364
 365         memset(&proc, 0, sizeof(proc));
 366         proc.no_stdin = 1;
 367         proc.stdout_to_stderr = 1;
 368         proc.err = use_sideband ? -1 : 0;
 369         proc.argv = argv;
 370
 371         code = start_command(&proc);
 372         if (code)
 373                 return code;
 374         if (use_sideband)
 375                 copy_to_sideband(proc.err, -1, NULL);
 376         return finish_command(&proc);
 377 }
 378
 379 static int is_ref_checked_out(const char *ref)
 380 {
 381         if (is_bare_repository())
 382                 return 0;
 383
 384         if (!head_name)
 385                 return 0;
 386         return !strcmp(head_name, ref);
 387 }
 388
 389 static char *refuse_unconfigured_deny_msg[] = {
 390         "By default, updating the current branch in a non-bare repository",
 391         "is denied, because it will make the index and work tree inconsistent",
 392         "with what you pushed, and will require 'git reset --hard' to match",
 393         "the work tree to HEAD.",
 394         "",
 395         "You can set 'receive.denyCurrentBranch' configuration variable to",
 396         "'ignore' or 'warn' in the remote repository to allow pushing into",
 397         "its current branch; however, this is not recommended unless you",
 398         "arranged to update its work tree to match what you pushed in some",
 399         "other way.",
 400         "",
 401         "To squelch this message and still keep the default behaviour, set",
 402         "'receive.denyCurrentBranch' configuration variable to 'refuse'."
 403 };
 404
 405 static void refuse_unconfigured_deny(void)
 406 {
 407         int i;
 408         for (i = 0; i < ARRAY_SIZE(refuse_unconfigured_deny_msg); i++)
 409                 rp_error("%s", refuse_unconfigured_deny_msg[i]);
 410 }
 411
 412 static char *refuse_unconfigured_deny_delete_current_msg[] = {
 413         "By default, deleting the current branch is denied, because the next",
 414         "'git clone' won't result in any file checked out, causing confusion.",
 415         "",
 416         "You can set 'receive.denyDeleteCurrent' configuration variable to",
 417         "'warn' or 'ignore' in the remote repository to allow deleting the",
 418         "current branch, with or without a warning message.",
 419         "",
 420         "To squelch this message, you can set it to 'refuse'."
 421 };
 422
 423 static void refuse_unconfigured_deny_delete_current(void)
 424 {
 425         int i;
 426         for (i = 0;
 427              i < ARRAY_SIZE(refuse_unconfigured_deny_delete_current_msg);
 428              i++)
 429                 rp_error("%s", refuse_unconfigured_deny_delete_current_msg[i]);
 430 }
 431
 432 static int command_singleton_iterator(void *cb_data, unsigned char sha1[20]);
 433 static int update_shallow_ref(struct command *cmd, struct shallow_info *si)
 434 {
 435         static struct lock_file shallow_lock;
 436         struct sha1_array extra = SHA1_ARRAY_INIT;
 437         const char *alt_file;
 438         uint32_t mask = 1 << (cmd->index % 32);
 439         int i;
 440
 441         trace_printf_key("GIT_TRACE_SHALLOW",
 442                          "shallow: update_shallow_ref %s\n", cmd->ref_name);
 443         for (i = 0; i < si->shallow->nr; i++)
 444                 if (si->used_shallow[i] &&
 445                     (si->used_shallow[i][cmd->index / 32] & mask) &&
 446                     !delayed_reachability_test(si, i))
 447                         sha1_array_append(&extra, si->shallow->sha1[i]);
 448
 449         setup_alternate_shallow(&shallow_lock, &alt_file, &extra);
 450         if (check_shallow_connected(command_singleton_iterator,
 451                                     0, cmd, alt_file)) {
 452                 rollback_lock_file(&shallow_lock);
 453                 sha1_array_clear(&extra);
 454                 return -1;
 455         }
 456
 457         commit_lock_file(&shallow_lock);
 458
 459         /*
 460          * Make sure setup_alternate_shallow() for the next ref does
 461          * not lose these new roots..
 462          */
 463         for (i = 0; i < extra.nr; i++)
 464                 register_shallow(extra.sha1[i]);
 465
 466         si->shallow_ref[cmd->index] = 0;
 467         sha1_array_clear(&extra);
 468         return 0;
 469 }
 470
 471 static const char *update(struct command *cmd, struct shallow_info *si)
 472 {
 473         const char *name = cmd->ref_name;
 474         struct strbuf namespaced_name_buf = STRBUF_INIT;
 475         const char *namespaced_name;
 476         unsigned char *old_sha1 = cmd->old_sha1;
 477         unsigned char *new_sha1 = cmd->new_sha1;
 478         struct ref_lock *lock;
 479
 480         /* only refs/... are allowed */
 481         if (!starts_with(name, "refs/") || check_refname_format(name + 5, 0)) {
 482                 rp_error("refusing to create funny ref '%s' remotely", name);
 483                 return "funny refname";
 484         }
 485
 486         strbuf_addf(&namespaced_name_buf, "%s%s", get_git_namespace(), name);
 487         namespaced_name = strbuf_detach(&namespaced_name_buf, NULL);
 488
 489         if (is_ref_checked_out(namespaced_name)) {
 490                 switch (deny_current_branch) {
 491                 case DENY_IGNORE:
 492                         break;
 493                 case DENY_WARN:
 494                         rp_warning("updating the current branch");
 495                         break;
 496                 case DENY_REFUSE:
 497                 case DENY_UNCONFIGURED:
 498                         rp_error("refusing to update checked out branch: %s", name);
 499                         if (deny_current_branch == DENY_UNCONFIGURED)
 500                                 refuse_unconfigured_deny();
 501                         return "branch is currently checked out";
 502                 }
 503         }
 504
 505         if (!is_null_sha1(new_sha1) && !has_sha1_file(new_sha1)) {
 506                 error("unpack should have generated %s, "
 507                       "but I can't find it!", sha1_to_hex(new_sha1));
 508                 return "bad pack";
 509         }
 510
 511         if (!is_null_sha1(old_sha1) && is_null_sha1(new_sha1)) {
 512                 if (deny_deletes && starts_with(name, "refs/heads/")) {
 513                         rp_error("denying ref deletion for %s", name);
 514                         return "deletion prohibited";
 515                 }
 516
 517                 if (!strcmp(namespaced_name, head_name)) {
 518                         switch (deny_delete_current) {
 519                         case DENY_IGNORE:
 520                                 break;
 521                         case DENY_WARN:
 522                                 rp_warning("deleting the current branch");
 523                                 break;
 524                         case DENY_REFUSE:
 525                         case DENY_UNCONFIGURED:
 526                                 if (deny_delete_current == DENY_UNCONFIGURED)
 527                                         refuse_unconfigured_deny_delete_current();
 528                                 rp_error("refusing to delete the current branch: %s", name);
 529                                 return "deletion of the current branch prohibited";
 530                         }
 531                 }
 532         }
 533
 534         if (deny_non_fast_forwards && !is_null_sha1(new_sha1) &&
 535             !is_null_sha1(old_sha1) &&
 536             starts_with(name, "refs/heads/")) {
 537                 struct object *old_object, *new_object;
 538                 struct commit *old_commit, *new_commit;
 539
 540                 old_object = parse_object(old_sha1);
 541                 new_object = parse_object(new_sha1);
 542
 543                 if (!old_object || !new_object ||
 544                     old_object->type != OBJ_COMMIT ||
 545                     new_object->type != OBJ_COMMIT) {
 546                         error("bad sha1 objects for %s", name);
 547                         return "bad ref";
 548                 }
 549                 old_commit = (struct commit *)old_object;
 550                 new_commit = (struct commit *)new_object;
 551                 if (!in_merge_bases(old_commit, new_commit)) {
 552                         rp_error("denying non-fast-forward %s"
 553                                  " (you should pull first)", name);
 554                         return "non-fast-forward";
 555                 }
 556         }
 557         if (run_update_hook(cmd)) {
 558                 rp_error("hook declined to update %s", name);
 559                 return "hook declined";
 560         }
 561
 562         if (is_null_sha1(new_sha1)) {
 563                 if (!parse_object(old_sha1)) {
 564                         old_sha1 = NULL;
 565                         if (ref_exists(name)) {
 566                                 rp_warning("Allowing deletion of corrupt ref.");
 567                         } else {
 568                                 rp_warning("Deleting a non-existent ref.");
 569                                 cmd->did_not_exist = 1;
 570                         }
 571                 }
 572                 if (delete_ref(namespaced_name, old_sha1, 0)) {
 573                         rp_error("failed to delete %s", name);
 574                         return "failed to delete";
 575                 }
 576                 return NULL; /* good */
 577         }
 578         else {
 579                 if (shallow_update && si->shallow_ref[cmd->index] &&
 580                     update_shallow_ref(cmd, si))
 581                         return "shallow error";
 582
 583                 lock = lock_any_ref_for_update(namespaced_name, old_sha1,
 584                                                0, NULL);
 585                 if (!lock) {
 586                         rp_error("failed to lock %s", name);
 587                         return "failed to lock";
 588                 }
 589                 if (write_ref_sha1(lock, new_sha1, "push")) {
 590                         return "failed to write"; /* error() already called */
 591                 }
 592                 return NULL; /* good */
 593         }
 594 }
 595
 596 static void run_update_post_hook(struct command *commands)
 597 {
 598         struct command *cmd;
 599         int argc;
 600         const char **argv;
 601         struct child_process proc;
 602         char *hook;
 603
 604         hook = find_hook("post-update");
 605         for (argc = 0, cmd = commands; cmd; cmd = cmd->next) {
 606                 if (cmd->error_string || cmd->did_not_exist)
 607                         continue;
 608                 argc++;
 609         }
 610         if (!argc || !hook)
 611                 return;
 612
 613         argv = xmalloc(sizeof(*argv) * (2 + argc));
 614         argv[0] = hook;
 615
 616         for (argc = 1, cmd = commands; cmd; cmd = cmd->next) {
 617                 if (cmd->error_string || cmd->did_not_exist)
 618                         continue;
 619                 argv[argc] = xstrdup(cmd->ref_name);
 620                 argc++;
 621         }
 622         argv[argc] = NULL;
 623
 624         memset(&proc, 0, sizeof(proc));
 625         proc.no_stdin = 1;
 626         proc.stdout_to_stderr = 1;
 627         proc.err = use_sideband ? -1 : 0;
 628         proc.argv = argv;
 629
 630         if (!start_command(&proc)) {
 631                 if (use_sideband)
 632                         copy_to_sideband(proc.err, -1, NULL);
 633                 finish_command(&proc);
 634         }
 635 }
 636
 637 static void check_aliased_update(struct command *cmd, struct string_list *list)
 638 {
 639         struct strbuf buf = STRBUF_INIT;
 640         const char *dst_name;
 641         struct string_list_item *item;
 642         struct command *dst_cmd;
 643         unsigned char sha1[20];
 644         char cmd_oldh[41], cmd_newh[41], dst_oldh[41], dst_newh[41];
 645         int flag;
 646
 647         strbuf_addf(&buf, "%s%s", get_git_namespace(), cmd->ref_name);
 648         dst_name = resolve_ref_unsafe(buf.buf, sha1, 0, &flag);
 649         strbuf_release(&buf);
 650
 651         if (!(flag & REF_ISSYMREF))
 652                 return;
 653
 654         dst_name = strip_namespace(dst_name);
 655         if (!dst_name) {
 656                 rp_error("refusing update to broken symref '%s'", cmd->ref_name);
 657                 cmd->skip_update = 1;
 658                 cmd->error_string = "broken symref";
 659                 return;
 660         }
 661
 662         if ((item = string_list_lookup(list, dst_name)) == NULL)
 663                 return;
 664
 665         cmd->skip_update = 1;
 666
 667         dst_cmd = (struct command *) item->util;
 668
 669         if (!hashcmp(cmd->old_sha1, dst_cmd->old_sha1) &&
 670             !hashcmp(cmd->new_sha1, dst_cmd->new_sha1))
 671                 return;
 672
 673         dst_cmd->skip_update = 1;
 674
 675         strcpy(cmd_oldh, find_unique_abbrev(cmd->old_sha1, DEFAULT_ABBREV));
 676         strcpy(cmd_newh, find_unique_abbrev(cmd->new_sha1, DEFAULT_ABBREV));
 677         strcpy(dst_oldh, find_unique_abbrev(dst_cmd->old_sha1, DEFAULT_ABBREV));
 678         strcpy(dst_newh, find_unique_abbrev(dst_cmd->new_sha1, DEFAULT_ABBREV));
 679         rp_error("refusing inconsistent update between symref '%s' (%s..%s) and"
 680                  " its target '%s' (%s..%s)",
 681                  cmd->ref_name, cmd_oldh, cmd_newh,
 682                  dst_cmd->ref_name, dst_oldh, dst_newh);
 683
 684         cmd->error_string = dst_cmd->error_string =
 685                 "inconsistent aliased update";
 686 }
 687
 688 static void check_aliased_updates(struct command *commands)
 689 {
 690         struct command *cmd;
 691         struct string_list ref_list = STRING_LIST_INIT_NODUP;
 692
 693         for (cmd = commands; cmd; cmd = cmd->next) {
 694                 struct string_list_item *item =
 695                         string_list_append(&ref_list, cmd->ref_name);
 696                 item->util = (void *)cmd;
 697         }
 698         sort_string_list(&ref_list);
 699
 700         for (cmd = commands; cmd; cmd = cmd->next) {
 701                 if (!cmd->error_string)
 702                         check_aliased_update(cmd, &ref_list);
 703         }
 704
 705         string_list_clear(&ref_list, 0);
 706 }
 707
 708 static int command_singleton_iterator(void *cb_data, unsigned char sha1[20])
 709 {
 710         struct command **cmd_list = cb_data;
 711         struct command *cmd = *cmd_list;
 712
 713         if (!cmd || is_null_sha1(cmd->new_sha1))
 714                 return -1; /* end of list */
 715         *cmd_list = NULL; /* this returns only one */
 716         hashcpy(sha1, cmd->new_sha1);
 717         return 0;
 718 }
 719
 720 static void set_connectivity_errors(struct command *commands,
 721                                     struct shallow_info *si)
 722 {
 723         struct command *cmd;
 724
 725         for (cmd = commands; cmd; cmd = cmd->next) {
 726                 struct command *singleton = cmd;
 727                 if (shallow_update && si->shallow_ref[cmd->index])
 728                         /* to be checked in update_shallow_ref() */
 729                         continue;
 730                 if (!check_everything_connected(command_singleton_iterator,
 731                                                 0, &singleton))
 732                         continue;
 733                 cmd->error_string = "missing necessary objects";
 734         }
 735 }
 736
 737 struct iterate_data {
 738         struct command *cmds;
 739         struct shallow_info *si;
 740 };
 741
 742 static int iterate_receive_command_list(void *cb_data, unsigned char sha1[20])
 743 {
 744         struct iterate_data *data = cb_data;
 745         struct command **cmd_list = &data->cmds;
 746         struct command *cmd = *cmd_list;
 747
 748         for (; cmd; cmd = cmd->next) {
 749                 if (shallow_update && data->si->shallow_ref[cmd->index])
 750                         /* to be checked in update_shallow_ref() */
 751                         continue;
 752                 if (!is_null_sha1(cmd->new_sha1) && !cmd->skip_update) {
 753                         hashcpy(sha1, cmd->new_sha1);
 754                         *cmd_list = cmd->next;
 755                         return 0;
 756                 }
 757         }
 758         *cmd_list = NULL;
 759         return -1; /* end of list */
 760 }
 761
 762 static void reject_updates_to_hidden(struct command *commands)
 763 {
 764         struct command *cmd;
 765
 766         for (cmd = commands; cmd; cmd = cmd->next) {
 767                 if (cmd->error_string || !ref_is_hidden(cmd->ref_name))
 768                         continue;
 769                 if (is_null_sha1(cmd->new_sha1))
 770                         cmd->error_string = "deny deleting a hidden ref";
 771                 else
 772                         cmd->error_string = "deny updating a hidden ref";
 773         }
 774 }
 775
 776 static void execute_commands(struct command *commands,
 777                              const char *unpacker_error,
 778                              struct shallow_info *si)
 779 {
 780         int checked_connectivity;
 781         struct command *cmd;
 782         unsigned char sha1[20];
 783         struct iterate_data data;
 784
 785         if (unpacker_error) {
 786                 for (cmd = commands; cmd; cmd = cmd->next)
 787                         cmd->error_string = "unpacker error";
 788                 return;
 789         }
 790
 791         data.cmds = commands;
 792         data.si = si;
 793         if (check_everything_connected(iterate_receive_command_list, 0, &data))
 794                 set_connectivity_errors(commands, si);
 795
 796         reject_updates_to_hidden(commands);
 797
 798         if (run_receive_hook(commands, "pre-receive", 0)) {
 799                 for (cmd = commands; cmd; cmd = cmd->next) {
 800                         if (!cmd->error_string)
 801                                 cmd->error_string = "pre-receive hook declined";
 802                 }
 803                 return;
 804         }
 805
 806         check_aliased_updates(commands);
 807
 808         free(head_name_to_free);
 809         head_name = head_name_to_free = resolve_refdup("HEAD", sha1, 0, NULL);
 810
 811         checked_connectivity = 1;
 812         for (cmd = commands; cmd; cmd = cmd->next) {
 813                 if (cmd->error_string)
 814                         continue;
 815
 816                 if (cmd->skip_update)
 817                         continue;
 818
 819                 cmd->error_string = update(cmd, si);
 820                 if (shallow_update && !cmd->error_string &&
 821                     si->shallow_ref[cmd->index]) {
 822                         error("BUG: connectivity check has not been run on ref %s",
 823                               cmd->ref_name);
 824                         checked_connectivity = 0;
 825                 }
 826         }
 827
 828         if (shallow_update && !checked_connectivity)
 829                 error("BUG: run 'git fsck' for safety.\n"
 830                       "If there are errors, try to remove "
 831                       "the reported refs above");
 832 }
 833
 834 static struct command *read_head_info(struct sha1_array *shallow)
 835 {
 836         struct command *commands = NULL;
 837         struct command **p = &commands;
 838         for (;;) {
 839                 char *line;
 840                 unsigned char old_sha1[20], new_sha1[20];
 841                 struct command *cmd;
 842                 char *refname;
 843                 int len, reflen;
 844
 845                 line = packet_read_line(0, &len);
 846                 if (!line)
 847                         break;
 848
 849                 if (len == 48 && starts_with(line, "shallow ")) {
 850                         if (get_sha1_hex(line + 8, old_sha1))
 851                                 die("protocol error: expected shallow sha, got '%s'", line + 8);
 852                         sha1_array_append(shallow, old_sha1);
 853                         continue;
 854                 }
 855
 856                 if (len < 83 ||
 857                     line[40] != ' ' ||
 858                     line[81] != ' ' ||
 859                     get_sha1_hex(line, old_sha1) ||
 860                     get_sha1_hex(line + 41, new_sha1))
 861                         die("protocol error: expected old/new/ref, got '%s'",
 862                             line);
 863
 864                 refname = line + 82;
 865                 reflen = strlen(refname);
 866                 if (reflen + 82 < len) {
 867                         const char *feature_list = refname + reflen + 1;
 868                         if (parse_feature_request(feature_list, "report-status"))
 869                                 report_status = 1;
 870                         if (parse_feature_request(feature_list, "side-band-64k"))
 871                                 use_sideband = LARGE_PACKET_MAX;
 872                         if (parse_feature_request(feature_list, "quiet"))
 873                                 quiet = 1;
 874                 }
 875                 cmd = xcalloc(1, sizeof(struct command) + len - 80);
 876                 hashcpy(cmd->old_sha1, old_sha1);
 877                 hashcpy(cmd->new_sha1, new_sha1);
 878                 memcpy(cmd->ref_name, line + 82, len - 81);
 879                 *p = cmd;
 880                 p = &cmd->next;
 881         }
 882         return commands;
 883 }
 884
 885 static const char *parse_pack_header(struct pack_header *hdr)
 886 {
 887         switch (read_pack_header(0, hdr)) {
 888         case PH_ERROR_EOF:
 889                 return "eof before pack header was fully read";
 890
 891         case PH_ERROR_PACK_SIGNATURE:
 892                 return "protocol error (pack signature mismatch detected)";
 893
 894         case PH_ERROR_PROTOCOL:
 895                 return "protocol error (pack version unsupported)";
 896
 897         default:
 898                 return "unknown error in parse_pack_header";
 899
 900         case 0:
 901                 return NULL;
 902         }
 903 }
 904
 905 static const char *pack_lockfile;
 906
 907 static const char *unpack(int err_fd, struct shallow_info *si)
 908 {
 909         struct pack_header hdr;
 910         struct argv_array av = ARGV_ARRAY_INIT;
 911         const char *hdr_err;
 912         int status;
 913         char hdr_arg[38];
 914         struct child_process child;
 915         int fsck_objects = (receive_fsck_objects >= 0
 916                             ? receive_fsck_objects
 917                             : transfer_fsck_objects >= 0
 918                             ? transfer_fsck_objects
 919                             : 0);
 920
 921         hdr_err = parse_pack_header(&hdr);
 922         if (hdr_err) {
 923                 if (err_fd > 0)
 924                         close(err_fd);
 925                 return hdr_err;
 926         }
 927         snprintf(hdr_arg, sizeof(hdr_arg),
 928                         "--pack_header=%"PRIu32",%"PRIu32,
 929                         ntohl(hdr.hdr_version), ntohl(hdr.hdr_entries));
 930
 931         if (si->nr_ours || si->nr_theirs) {
 932                 alt_shallow_file = setup_temporary_shallow(si->shallow);
 933                 argv_array_pushl(&av, "--shallow-file", alt_shallow_file, NULL);
 934         }
 935
 936         memset(&child, 0, sizeof(child));
 937         if (ntohl(hdr.hdr_entries) < unpack_limit) {
 938                 argv_array_pushl(&av, "unpack-objects", hdr_arg, NULL);
 939                 if (quiet)
 940                         argv_array_push(&av, "-q");
 941                 if (fsck_objects)
 942                         argv_array_push(&av, "--strict");
 943                 child.argv = av.argv;
 944                 child.no_stdout = 1;
 945                 child.err = err_fd;
 946                 child.git_cmd = 1;
 947                 status = run_command(&child);
 948                 if (status)
 949                         return "unpack-objects abnormal exit";
 950         } else {
 951                 int s;
 952                 char keep_arg[256];
 953
 954                 s = sprintf(keep_arg, "--keep=receive-pack %"PRIuMAX" on ", (uintmax_t) getpid());
 955                 if (gethostname(keep_arg + s, sizeof(keep_arg) - s))
 956                         strcpy(keep_arg + s, "localhost");
 957
 958                 argv_array_pushl(&av, "index-pack",
 959                                  "--stdin", hdr_arg, keep_arg, NULL);
 960                 if (fsck_objects)
 961                         argv_array_push(&av, "--strict");
 962                 if (fix_thin)
 963                         argv_array_push(&av, "--fix-thin");
 964                 child.argv = av.argv;
 965                 child.out = -1;
 966                 child.err = err_fd;
 967                 child.git_cmd = 1;
 968                 status = start_command(&child);
 969                 if (status)
 970                         return "index-pack fork failed";
 971                 pack_lockfile = index_pack_lockfile(child.out);
 972                 close(child.out);
 973                 status = finish_command(&child);
 974                 if (status)
 975                         return "index-pack abnormal exit";
 976                 reprepare_packed_git();
 977         }
 978         return NULL;
 979 }
 980
 981 static const char *unpack_with_sideband(struct shallow_info *si)
 982 {
 983         struct async muxer;
 984         const char *ret;
 985
 986         if (!use_sideband)
 987                 return unpack(0, si);
 988
 989         memset(&muxer, 0, sizeof(muxer));
 990         muxer.proc = copy_to_sideband;
 991         muxer.in = -1;
 992         if (start_async(&muxer))
 993                 return NULL;
 994
 995         ret = unpack(muxer.in, si);
 996
 997         finish_async(&muxer);
 998         return ret;
 999 }
1000
1001 static void prepare_shallow_update(struct command *commands,
1002                                    struct shallow_info *si)
1003 {
1004         int i, j, k, bitmap_size = (si->ref->nr + 31) / 32;
1005
1006         si->used_shallow = xmalloc(sizeof(*si->used_shallow) *
1007                                    si->shallow->nr);
1008         assign_shallow_commits_to_refs(si, si->used_shallow, NULL);
1009
1010         si->need_reachability_test =
1011                 xcalloc(si->shallow->nr, sizeof(*si->need_reachability_test));
1012         si->reachable =
1013                 xcalloc(si->shallow->nr, sizeof(*si->reachable));
1014         si->shallow_ref = xcalloc(si->ref->nr, sizeof(*si->shallow_ref));
1015
1016         for (i = 0; i < si->nr_ours; i++)
1017                 si->need_reachability_test[si->ours[i]] = 1;
1018
1019         for (i = 0; i < si->shallow->nr; i++) {
1020                 if (!si->used_shallow[i])
1021                         continue;
1022                 for (j = 0; j < bitmap_size; j++) {
1023                         if (!si->used_shallow[i][j])
1024                                 continue;
1025                         si->need_reachability_test[i]++;
1026                         for (k = 0; k < 32; k++)
1027                                 if (si->used_shallow[i][j] & (1 << k))
1028                                         si->shallow_ref[j * 32 + k]++;
1029                 }
1030
1031                 /*
1032                  * true for those associated with some refs and belong
1033                  * in "ours" list aka "step 7 not done yet"
1034                  */
1035                 si->need_reachability_test[i] =
1036                         si->need_reachability_test[i] > 1;
1037         }
1038
1039         /*
1040          * keep hooks happy by forcing a temporary shallow file via
1041          * env variable because we can't add --shallow-file to every
1042          * command. check_everything_connected() will be done with
1043          * true .git/shallow though.
1044          */
1045         setenv(GIT_SHALLOW_FILE_ENVIRONMENT, alt_shallow_file, 1);
1046 }
1047
1048 static void update_shallow_info(struct command *commands,
1049                                 struct shallow_info *si,
1050                                 struct sha1_array *ref)
1051 {
1052         struct command *cmd;
1053         int *ref_status;
1054         remove_nonexistent_theirs_shallow(si);
1055         if (!si->nr_ours && !si->nr_theirs) {
1056                 shallow_update = 0;
1057                 return;
1058         }
1059
1060         for (cmd = commands; cmd; cmd = cmd->next) {
1061                 if (is_null_sha1(cmd->new_sha1))
1062                         continue;
1063                 sha1_array_append(ref, cmd->new_sha1);
1064                 cmd->index = ref->nr - 1;
1065         }
1066         si->ref = ref;
1067
1068         if (shallow_update) {
1069                 prepare_shallow_update(commands, si);
1070                 return;
1071         }
1072
1073         ref_status = xmalloc(sizeof(*ref_status) * ref->nr);
1074         assign_shallow_commits_to_refs(si, NULL, ref_status);
1075         for (cmd = commands; cmd; cmd = cmd->next) {
1076                 if (is_null_sha1(cmd->new_sha1))
1077                         continue;
1078                 if (ref_status[cmd->index]) {
1079                         cmd->error_string = "shallow update not allowed";
1080                         cmd->skip_update = 1;
1081                 }
1082         }
1083         free(ref_status);
1084 }
1085
1086 static void report(struct command *commands, const char *unpack_status)
1087 {
1088         struct command *cmd;
1089         struct strbuf buf = STRBUF_INIT;
1090
1091         packet_buf_write(&buf, "unpack %s\n",
1092                          unpack_status ? unpack_status : "ok");
1093         for (cmd = commands; cmd; cmd = cmd->next) {
1094                 if (!cmd->error_string)
1095                         packet_buf_write(&buf, "ok %s\n",
1096                                          cmd->ref_name);
1097                 else
1098                         packet_buf_write(&buf, "ng %s %s\n",
1099                                          cmd->ref_name, cmd->error_string);
1100         }
1101         packet_buf_flush(&buf);
1102
1103         if (use_sideband)
1104                 send_sideband(1, 1, buf.buf, buf.len, use_sideband);
1105         else
1106                 write_or_die(1, buf.buf, buf.len);
1107         strbuf_release(&buf);
1108 }
1109
1110 static int delete_only(struct command *commands)
1111 {
1112         struct command *cmd;
1113         for (cmd = commands; cmd; cmd = cmd->next) {
1114                 if (!is_null_sha1(cmd->new_sha1))
1115                         return 0;
1116         }
1117         return 1;
1118 }
1119
1120 int cmd_receive_pack(int argc, const char **argv, const char *prefix)
1121 {
1122         int advertise_refs = 0;
1123         int stateless_rpc = 0;
1124         int i;
1125         char *dir = NULL;
1126         struct command *commands;
1127         struct sha1_array shallow = SHA1_ARRAY_INIT;
1128         struct sha1_array ref = SHA1_ARRAY_INIT;
1129         struct shallow_info si;
1130
1131         packet_trace_identity("receive-pack");
1132
1133         argv++;
1134         for (i = 1; i < argc; i++) {
1135                 const char *arg = *argv++;
1136
1137                 if (*arg == '-') {
1138                         if (!strcmp(arg, "--quiet")) {
1139                                 quiet = 1;
1140                                 continue;
1141                         }
1142
1143                         if (!strcmp(arg, "--advertise-refs")) {
1144                                 advertise_refs = 1;
1145                                 continue;
1146                         }
1147                         if (!strcmp(arg, "--stateless-rpc")) {
1148                                 stateless_rpc = 1;
1149                                 continue;
1150                         }
1151                         if (!strcmp(arg, "--reject-thin-pack-for-testing")) {
1152                                 fix_thin = 0;
1153                                 continue;
1154                         }
1155
1156                         usage(receive_pack_usage);
1157                 }
1158                 if (dir)
1159                         usage(receive_pack_usage);
1160                 dir = xstrdup(arg);
1161         }
1162         if (!dir)
1163                 usage(receive_pack_usage);
1164
1165         setup_path();
1166
1167         if (!enter_repo(dir, 0))
1168                 die("'%s' does not appear to be a git repository", dir);
1169
1170         git_config(receive_pack_config, NULL);
1171
1172         if (0 <= transfer_unpack_limit)
1173                 unpack_limit = transfer_unpack_limit;
1174         else if (0 <= receive_unpack_limit)
1175                 unpack_limit = receive_unpack_limit;
1176
1177         if (advertise_refs || !stateless_rpc) {
1178                 write_head_info();
1179         }
1180         if (advertise_refs)
1181                 return 0;
1182
1183         if ((commands = read_head_info(&shallow)) != NULL) {
1184                 const char *unpack_status = NULL;
1185
1186                 prepare_shallow_info(&si, &shallow);
1187                 if (!si.nr_ours && !si.nr_theirs)
1188                         shallow_update = 0;
1189                 if (!delete_only(commands)) {
1190                         unpack_status = unpack_with_sideband(&si);
1191                         update_shallow_info(commands, &si, &ref);
1192                 }
1193                 execute_commands(commands, unpack_status, &si);
1194                 if (pack_lockfile)
1195                         unlink_or_warn(pack_lockfile);
1196                 if (report_status)
1197                         report(commands, unpack_status);
1198                 run_receive_hook(commands, "post-receive", 1);
1199                 run_update_post_hook(commands);
1200                 if (auto_gc) {
1201                         const char *argv_gc_auto[] = {
1202                                 "gc", "--auto", "--quiet", NULL,
1203                         };
1204                         int opt = RUN_GIT_CMD | RUN_COMMAND_STDOUT_TO_STDERR;
1205                         run_command_v_opt(argv_gc_auto, opt);
1206                 }
1207                 if (auto_update_server_info)
1208                         update_server_info(0);
1209                 clear_shallow_info(&si);
1210         }
1211         if (use_sideband)
1212                 packet_flush(1);
1213         sha1_array_clear(&shallow);
1214         sha1_array_clear(&ref);
1215         return 0;
1216 }