git.oblomov.eu Git - git/blob - upload-pack.c

   1 #include "cache.h"
   2 #include "refs.h"
   3 #include "pkt-line.h"
   4 #include "sideband.h"
   5 #include "tag.h"
   6 #include "object.h"
   7 #include "commit.h"
   8 #include "exec_cmd.h"
   9 #include "diff.h"
  10 #include "revision.h"
  11 #include "list-objects.h"
  12 #include "run-command.h"
  13 #include "connect.h"
  14 #include "sigchain.h"
  15 #include "version.h"
  16 #include "string-list.h"
  17
  18 static const char upload_pack_usage[] = "git upload-pack [--strict] [--timeout=<n>] <dir>";
  19
  20 /* Remember to update object flag allocation in object.h */
  21 #define THEY_HAVE       (1u << 11)
  22 #define OUR_REF         (1u << 12)
  23 #define WANTED          (1u << 13)
  24 #define COMMON_KNOWN    (1u << 14)
  25 #define REACHABLE       (1u << 15)
  26
  27 #define SHALLOW         (1u << 16)
  28 #define NOT_SHALLOW     (1u << 17)
  29 #define CLIENT_SHALLOW  (1u << 18)
  30 #define HIDDEN_REF      (1u << 19)
  31
  32 static unsigned long oldest_have;
  33
  34 static int multi_ack;
  35 static int no_done;
  36 static int use_thin_pack, use_ofs_delta, use_include_tag;
  37 static int no_progress, daemon_mode;
  38 /* Allow specifying sha1 if it is a ref tip. */
  39 #define ALLOW_TIP_SHA1  01
  40 /* Allow request of a sha1 if it is reachable from a ref (possibly hidden ref). */
  41 #define ALLOW_REACHABLE_SHA1    02
  42 static unsigned int allow_unadvertised_object_request;
  43 static int shallow_nr;
  44 static struct object_array have_obj;
  45 static struct object_array want_obj;
  46 static struct object_array extra_edge_obj;
  47 static unsigned int timeout;
  48 static int keepalive = 5;
  49 /* 0 for no sideband,
  50  * otherwise maximum packet size (up to 65520 bytes).
  51  */
  52 static int use_sideband;
  53 static int advertise_refs;
  54 static int stateless_rpc;
  55
  56 static void reset_timeout(void)
  57 {
  58         alarm(timeout);
  59 }
  60
  61 static ssize_t send_client_data(int fd, const char *data, ssize_t sz)
  62 {
  63         if (use_sideband)
  64                 return send_sideband(1, fd, data, sz, use_sideband);
  65         if (fd == 3)
  66                 /* emergency quit */
  67                 fd = 2;
  68         if (fd == 2) {
  69                 /* XXX: are we happy to lose stuff here? */
  70                 xwrite(fd, data, sz);
  71                 return sz;
  72         }
  73         write_or_die(fd, data, sz);
  74         return sz;
  75 }
  76
  77 static int write_one_shallow(const struct commit_graft *graft, void *cb_data)
  78 {
  79         FILE *fp = cb_data;
  80         if (graft->nr_parent == -1)
  81                 fprintf(fp, "--shallow %s\n", oid_to_hex(&graft->oid));
  82         return 0;
  83 }
  84
  85 static void create_pack_file(void)
  86 {
  87         struct child_process pack_objects = CHILD_PROCESS_INIT;
  88         char data[8193], progress[128];
  89         char abort_msg[] = "aborting due to possible repository "
  90                 "corruption on the remote side.";
  91         int buffered = -1;
  92         ssize_t sz;
  93         const char *argv[13];
  94         int i, arg = 0;
  95         FILE *pipe_fd;
  96
  97         if (shallow_nr) {
  98                 argv[arg++] = "--shallow-file";
  99                 argv[arg++] = "";
 100         }
 101         argv[arg++] = "pack-objects";
 102         argv[arg++] = "--revs";
 103         if (use_thin_pack)
 104                 argv[arg++] = "--thin";
 105
 106         argv[arg++] = "--stdout";
 107         if (shallow_nr)
 108                 argv[arg++] = "--shallow";
 109         if (!no_progress)
 110                 argv[arg++] = "--progress";
 111         if (use_ofs_delta)
 112                 argv[arg++] = "--delta-base-offset";
 113         if (use_include_tag)
 114                 argv[arg++] = "--include-tag";
 115         argv[arg++] = NULL;
 116
 117         pack_objects.in = -1;
 118         pack_objects.out = -1;
 119         pack_objects.err = -1;
 120         pack_objects.git_cmd = 1;
 121         pack_objects.argv = argv;
 122
 123         if (start_command(&pack_objects))
 124                 die("git upload-pack: unable to fork git-pack-objects");
 125
 126         pipe_fd = xfdopen(pack_objects.in, "w");
 127
 128         if (shallow_nr)
 129                 for_each_commit_graft(write_one_shallow, pipe_fd);
 130
 131         for (i = 0; i < want_obj.nr; i++)
 132                 fprintf(pipe_fd, "%s\n",
 133                         oid_to_hex(&want_obj.objects[i].item->oid));
 134         fprintf(pipe_fd, "--not\n");
 135         for (i = 0; i < have_obj.nr; i++)
 136                 fprintf(pipe_fd, "%s\n",
 137                         oid_to_hex(&have_obj.objects[i].item->oid));
 138         for (i = 0; i < extra_edge_obj.nr; i++)
 139                 fprintf(pipe_fd, "%s\n",
 140                         oid_to_hex(&extra_edge_obj.objects[i].item->oid));
 141         fprintf(pipe_fd, "\n");
 142         fflush(pipe_fd);
 143         fclose(pipe_fd);
 144
 145         /* We read from pack_objects.err to capture stderr output for
 146          * progress bar, and pack_objects.out to capture the pack data.
 147          */
 148
 149         while (1) {
 150                 struct pollfd pfd[2];
 151                 int pe, pu, pollsize;
 152                 int ret;
 153
 154                 reset_timeout();
 155
 156                 pollsize = 0;
 157                 pe = pu = -1;
 158
 159                 if (0 <= pack_objects.out) {
 160                         pfd[pollsize].fd = pack_objects.out;
 161                         pfd[pollsize].events = POLLIN;
 162                         pu = pollsize;
 163                         pollsize++;
 164                 }
 165                 if (0 <= pack_objects.err) {
 166                         pfd[pollsize].fd = pack_objects.err;
 167                         pfd[pollsize].events = POLLIN;
 168                         pe = pollsize;
 169                         pollsize++;
 170                 }
 171
 172                 if (!pollsize)
 173                         break;
 174
 175                 ret = poll(pfd, pollsize,
 176                         keepalive < 0 ? -1 : 1000 * keepalive);
 177
 178                 if (ret < 0) {
 179                         if (errno != EINTR) {
 180                                 error("poll failed, resuming: %s",
 181                                       strerror(errno));
 182                                 sleep(1);
 183                         }
 184                         continue;
 185                 }
 186                 if (0 <= pe && (pfd[pe].revents & (POLLIN|POLLHUP))) {
 187                         /* Status ready; we ship that in the side-band
 188                          * or dump to the standard error.
 189                          */
 190                         sz = xread(pack_objects.err, progress,
 191                                   sizeof(progress));
 192                         if (0 < sz)
 193                                 send_client_data(2, progress, sz);
 194                         else if (sz == 0) {
 195                                 close(pack_objects.err);
 196                                 pack_objects.err = -1;
 197                         }
 198                         else
 199                                 goto fail;
 200                         /* give priority to status messages */
 201                         continue;
 202                 }
 203                 if (0 <= pu && (pfd[pu].revents & (POLLIN|POLLHUP))) {
 204                         /* Data ready; we keep the last byte to ourselves
 205                          * in case we detect broken rev-list, so that we
 206                          * can leave the stream corrupted.  This is
 207                          * unfortunate -- unpack-objects would happily
 208                          * accept a valid packdata with trailing garbage,
 209                          * so appending garbage after we pass all the
 210                          * pack data is not good enough to signal
 211                          * breakage to downstream.
 212                          */
 213                         char *cp = data;
 214                         ssize_t outsz = 0;
 215                         if (0 <= buffered) {
 216                                 *cp++ = buffered;
 217                                 outsz++;
 218                         }
 219                         sz = xread(pack_objects.out, cp,
 220                                   sizeof(data) - outsz);
 221                         if (0 < sz)
 222                                 ;
 223                         else if (sz == 0) {
 224                                 close(pack_objects.out);
 225                                 pack_objects.out = -1;
 226                         }
 227                         else
 228                                 goto fail;
 229                         sz += outsz;
 230                         if (1 < sz) {
 231                                 buffered = data[sz-1] & 0xFF;
 232                                 sz--;
 233                         }
 234                         else
 235                                 buffered = -1;
 236                         sz = send_client_data(1, data, sz);
 237                         if (sz < 0)
 238                                 goto fail;
 239                 }
 240
 241                 /*
 242                  * We hit the keepalive timeout without saying anything; send
 243                  * an empty message on the data sideband just to let the other
 244                  * side know we're still working on it, but don't have any data
 245                  * yet.
 246                  *
 247                  * If we don't have a sideband channel, there's no room in the
 248                  * protocol to say anything, so those clients are just out of
 249                  * luck.
 250                  */
 251                 if (!ret && use_sideband) {
 252                         static const char buf[] = "0005\1";
 253                         write_or_die(1, buf, 5);
 254                 }
 255         }
 256
 257         if (finish_command(&pack_objects)) {
 258                 error("git upload-pack: git-pack-objects died with error.");
 259                 goto fail;
 260         }
 261
 262         /* flush the data */
 263         if (0 <= buffered) {
 264                 data[0] = buffered;
 265                 sz = send_client_data(1, data, 1);
 266                 if (sz < 0)
 267                         goto fail;
 268                 fprintf(stderr, "flushed.\n");
 269         }
 270         if (use_sideband)
 271                 packet_flush(1);
 272         return;
 273
 274  fail:
 275         send_client_data(3, abort_msg, sizeof(abort_msg));
 276         die("git upload-pack: %s", abort_msg);
 277 }
 278
 279 static int got_sha1(char *hex, unsigned char *sha1)
 280 {
 281         struct object *o;
 282         int we_knew_they_have = 0;
 283
 284         if (get_sha1_hex(hex, sha1))
 285                 die("git upload-pack: expected SHA1 object, got '%s'", hex);
 286         if (!has_sha1_file(sha1))
 287                 return -1;
 288
 289         o = parse_object(sha1);
 290         if (!o)
 291                 die("oops (%s)", sha1_to_hex(sha1));
 292         if (o->type == OBJ_COMMIT) {
 293                 struct commit_list *parents;
 294                 struct commit *commit = (struct commit *)o;
 295                 if (o->flags & THEY_HAVE)
 296                         we_knew_they_have = 1;
 297                 else
 298                         o->flags |= THEY_HAVE;
 299                 if (!oldest_have || (commit->date < oldest_have))
 300                         oldest_have = commit->date;
 301                 for (parents = commit->parents;
 302                      parents;
 303                      parents = parents->next)
 304                         parents->item->object.flags |= THEY_HAVE;
 305         }
 306         if (!we_knew_they_have) {
 307                 add_object_array(o, NULL, &have_obj);
 308                 return 1;
 309         }
 310         return 0;
 311 }
 312
 313 static int reachable(struct commit *want)
 314 {
 315         struct commit_list *work = NULL;
 316
 317         commit_list_insert_by_date(want, &work);
 318         while (work) {
 319                 struct commit_list *list;
 320                 struct commit *commit = pop_commit(&work);
 321
 322                 if (commit->object.flags & THEY_HAVE) {
 323                         want->object.flags |= COMMON_KNOWN;
 324                         break;
 325                 }
 326                 if (!commit->object.parsed)
 327                         parse_object(commit->object.oid.hash);
 328                 if (commit->object.flags & REACHABLE)
 329                         continue;
 330                 commit->object.flags |= REACHABLE;
 331                 if (commit->date < oldest_have)
 332                         continue;
 333                 for (list = commit->parents; list; list = list->next) {
 334                         struct commit *parent = list->item;
 335                         if (!(parent->object.flags & REACHABLE))
 336                                 commit_list_insert_by_date(parent, &work);
 337                 }
 338         }
 339         want->object.flags |= REACHABLE;
 340         clear_commit_marks(want, REACHABLE);
 341         free_commit_list(work);
 342         return (want->object.flags & COMMON_KNOWN);
 343 }
 344
 345 static int ok_to_give_up(void)
 346 {
 347         int i;
 348
 349         if (!have_obj.nr)
 350                 return 0;
 351
 352         for (i = 0; i < want_obj.nr; i++) {
 353                 struct object *want = want_obj.objects[i].item;
 354
 355                 if (want->flags & COMMON_KNOWN)
 356                         continue;
 357                 want = deref_tag(want, "a want line", 0);
 358                 if (!want || want->type != OBJ_COMMIT) {
 359                         /* no way to tell if this is reachable by
 360                          * looking at the ancestry chain alone, so
 361                          * leave a note to ourselves not to worry about
 362                          * this object anymore.
 363                          */
 364                         want_obj.objects[i].item->flags |= COMMON_KNOWN;
 365                         continue;
 366                 }
 367                 if (!reachable((struct commit *)want))
 368                         return 0;
 369         }
 370         return 1;
 371 }
 372
 373 static int get_common_commits(void)
 374 {
 375         unsigned char sha1[20];
 376         char last_hex[41];
 377         int got_common = 0;
 378         int got_other = 0;
 379         int sent_ready = 0;
 380
 381         save_commit_buffer = 0;
 382
 383         for (;;) {
 384                 char *line = packet_read_line(0, NULL);
 385                 reset_timeout();
 386
 387                 if (!line) {
 388                         if (multi_ack == 2 && got_common
 389                             && !got_other && ok_to_give_up()) {
 390                                 sent_ready = 1;
 391                                 packet_write(1, "ACK %s ready\n", last_hex);
 392                         }
 393                         if (have_obj.nr == 0 || multi_ack)
 394                                 packet_write(1, "NAK\n");
 395
 396                         if (no_done && sent_ready) {
 397                                 packet_write(1, "ACK %s\n", last_hex);
 398                                 return 0;
 399                         }
 400                         if (stateless_rpc)
 401                                 exit(0);
 402                         got_common = 0;
 403                         got_other = 0;
 404                         continue;
 405                 }
 406                 if (starts_with(line, "have ")) {
 407                         switch (got_sha1(line+5, sha1)) {
 408                         case -1: /* they have what we do not */
 409                                 got_other = 1;
 410                                 if (multi_ack && ok_to_give_up()) {
 411                                         const char *hex = sha1_to_hex(sha1);
 412                                         if (multi_ack == 2) {
 413                                                 sent_ready = 1;
 414                                                 packet_write(1, "ACK %s ready\n", hex);
 415                                         } else
 416                                                 packet_write(1, "ACK %s continue\n", hex);
 417                                 }
 418                                 break;
 419                         default:
 420                                 got_common = 1;
 421                                 memcpy(last_hex, sha1_to_hex(sha1), 41);
 422                                 if (multi_ack == 2)
 423                                         packet_write(1, "ACK %s common\n", last_hex);
 424                                 else if (multi_ack)
 425                                         packet_write(1, "ACK %s continue\n", last_hex);
 426                                 else if (have_obj.nr == 1)
 427                                         packet_write(1, "ACK %s\n", last_hex);
 428                                 break;
 429                         }
 430                         continue;
 431                 }
 432                 if (!strcmp(line, "done")) {
 433                         if (have_obj.nr > 0) {
 434                                 if (multi_ack)
 435                                         packet_write(1, "ACK %s\n", last_hex);
 436                                 return 0;
 437                         }
 438                         packet_write(1, "NAK\n");
 439                         return -1;
 440                 }
 441                 die("git upload-pack: expected SHA1 list, got '%s'", line);
 442         }
 443 }
 444
 445 static int is_our_ref(struct object *o)
 446 {
 447         int allow_hidden_ref = (allow_unadvertised_object_request &
 448                         (ALLOW_TIP_SHA1 | ALLOW_REACHABLE_SHA1));
 449         return o->flags & ((allow_hidden_ref ? HIDDEN_REF : 0) | OUR_REF);
 450 }
 451
 452 static void check_non_tip(void)
 453 {
 454         static const char *argv[] = {
 455                 "rev-list", "--stdin", NULL,
 456         };
 457         static struct child_process cmd = CHILD_PROCESS_INIT;
 458         struct object *o;
 459         char namebuf[42]; /* ^ + SHA-1 + LF */
 460         int i;
 461
 462         /*
 463          * In the normal in-process case without
 464          * uploadpack.allowReachableSHA1InWant,
 465          * non-tip requests can never happen.
 466          */
 467         if (!stateless_rpc && !(allow_unadvertised_object_request & ALLOW_REACHABLE_SHA1))
 468                 goto error;
 469
 470         cmd.argv = argv;
 471         cmd.git_cmd = 1;
 472         cmd.no_stderr = 1;
 473         cmd.in = -1;
 474         cmd.out = -1;
 475
 476         if (start_command(&cmd))
 477                 goto error;
 478
 479         /*
 480          * If rev-list --stdin encounters an unknown commit, it
 481          * terminates, which will cause SIGPIPE in the write loop
 482          * below.
 483          */
 484         sigchain_push(SIGPIPE, SIG_IGN);
 485
 486         namebuf[0] = '^';
 487         namebuf[41] = '\n';
 488         for (i = get_max_object_index(); 0 < i; ) {
 489                 o = get_indexed_object(--i);
 490                 if (!o)
 491                         continue;
 492                 if (!is_our_ref(o))
 493                         continue;
 494                 memcpy(namebuf + 1, oid_to_hex(&o->oid), GIT_SHA1_HEXSZ);
 495                 if (write_in_full(cmd.in, namebuf, 42) < 0)
 496                         goto error;
 497         }
 498         namebuf[40] = '\n';
 499         for (i = 0; i < want_obj.nr; i++) {
 500                 o = want_obj.objects[i].item;
 501                 if (is_our_ref(o))
 502                         continue;
 503                 memcpy(namebuf, oid_to_hex(&o->oid), GIT_SHA1_HEXSZ);
 504                 if (write_in_full(cmd.in, namebuf, 41) < 0)
 505                         goto error;
 506         }
 507         close(cmd.in);
 508
 509         sigchain_pop(SIGPIPE);
 510
 511         /*
 512          * The commits out of the rev-list are not ancestors of
 513          * our ref.
 514          */
 515         i = read_in_full(cmd.out, namebuf, 1);
 516         if (i)
 517                 goto error;
 518         close(cmd.out);
 519
 520         /*
 521          * rev-list may have died by encountering a bad commit
 522          * in the history, in which case we do want to bail out
 523          * even when it showed no commit.
 524          */
 525         if (finish_command(&cmd))
 526                 goto error;
 527
 528         /* All the non-tip ones are ancestors of what we advertised */
 529         return;
 530
 531 error:
 532         /* Pick one of them (we know there at least is one) */
 533         for (i = 0; i < want_obj.nr; i++) {
 534                 o = want_obj.objects[i].item;
 535                 if (!is_our_ref(o))
 536                         die("git upload-pack: not our ref %s",
 537                             oid_to_hex(&o->oid));
 538         }
 539 }
 540
 541 static void send_shallow(struct commit_list *result)
 542 {
 543         while (result) {
 544                 struct object *object = &result->item->object;
 545                 if (!(object->flags & (CLIENT_SHALLOW|NOT_SHALLOW))) {
 546                         packet_write(1, "shallow %s",
 547                                      oid_to_hex(&object->oid));
 548                         register_shallow(object->oid.hash);
 549                         shallow_nr++;
 550                 }
 551                 result = result->next;
 552         }
 553 }
 554
 555 static void send_unshallow(const struct object_array *shallows)
 556 {
 557         int i;
 558
 559         for (i = 0; i < shallows->nr; i++) {
 560                 struct object *object = shallows->objects[i].item;
 561                 if (object->flags & NOT_SHALLOW) {
 562                         struct commit_list *parents;
 563                         packet_write(1, "unshallow %s",
 564                                      oid_to_hex(&object->oid));
 565                         object->flags &= ~CLIENT_SHALLOW;
 566                         /*
 567                          * We want to _register_ "object" as shallow, but we
 568                          * also need to traverse object's parents to deepen a
 569                          * shallow clone. Unregister it for now so we can
 570                          * parse and add the parents to the want list, then
 571                          * re-register it.
 572                          */
 573                         unregister_shallow(object->oid.hash);
 574                         object->parsed = 0;
 575                         parse_commit_or_die((struct commit *)object);
 576                         parents = ((struct commit *)object)->parents;
 577                         while (parents) {
 578                                 add_object_array(&parents->item->object,
 579                                                  NULL, &want_obj);
 580                                 parents = parents->next;
 581                         }
 582                         add_object_array(object, NULL, &extra_edge_obj);
 583                 }
 584                 /* make sure commit traversal conforms to client */
 585                 register_shallow(object->oid.hash);
 586         }
 587 }
 588
 589 static void deepen(int depth, const struct object_array *shallows)
 590 {
 591         if (depth == INFINITE_DEPTH && !is_repository_shallow()) {
 592                 int i;
 593
 594                 for (i = 0; i < shallows->nr; i++) {
 595                         struct object *object = shallows->objects[i].item;
 596                         object->flags |= NOT_SHALLOW;
 597                 }
 598         } else {
 599                 struct commit_list *result;
 600
 601                 result = get_shallow_commits(&want_obj, depth,
 602                                              SHALLOW, NOT_SHALLOW);
 603                 send_shallow(result);
 604                 free_commit_list(result);
 605         }
 606
 607         send_unshallow(shallows);
 608         packet_flush(1);
 609 }
 610
 611 static void receive_needs(void)
 612 {
 613         struct object_array shallows = OBJECT_ARRAY_INIT;
 614         int depth = 0;
 615         int has_non_tip = 0;
 616
 617         shallow_nr = 0;
 618         for (;;) {
 619                 struct object *o;
 620                 const char *features;
 621                 unsigned char sha1_buf[20];
 622                 char *line = packet_read_line(0, NULL);
 623                 reset_timeout();
 624                 if (!line)
 625                         break;
 626
 627                 if (starts_with(line, "shallow ")) {
 628                         unsigned char sha1[20];
 629                         struct object *object;
 630                         if (get_sha1_hex(line + 8, sha1))
 631                                 die("invalid shallow line: %s", line);
 632                         object = parse_object(sha1);
 633                         if (!object)
 634                                 continue;
 635                         if (object->type != OBJ_COMMIT)
 636                                 die("invalid shallow object %s", sha1_to_hex(sha1));
 637                         if (!(object->flags & CLIENT_SHALLOW)) {
 638                                 object->flags |= CLIENT_SHALLOW;
 639                                 add_object_array(object, NULL, &shallows);
 640                         }
 641                         continue;
 642                 }
 643                 if (starts_with(line, "deepen ")) {
 644                         char *end;
 645                         depth = strtol(line + 7, &end, 0);
 646                         if (end == line + 7 || depth <= 0)
 647                                 die("Invalid deepen: %s", line);
 648                         continue;
 649                 }
 650                 if (!starts_with(line, "want ") ||
 651                     get_sha1_hex(line+5, sha1_buf))
 652                         die("git upload-pack: protocol error, "
 653                             "expected to get sha, not '%s'", line);
 654
 655                 features = line + 45;
 656
 657                 if (parse_feature_request(features, "multi_ack_detailed"))
 658                         multi_ack = 2;
 659                 else if (parse_feature_request(features, "multi_ack"))
 660                         multi_ack = 1;
 661                 if (parse_feature_request(features, "no-done"))
 662                         no_done = 1;
 663                 if (parse_feature_request(features, "thin-pack"))
 664                         use_thin_pack = 1;
 665                 if (parse_feature_request(features, "ofs-delta"))
 666                         use_ofs_delta = 1;
 667                 if (parse_feature_request(features, "side-band-64k"))
 668                         use_sideband = LARGE_PACKET_MAX;
 669                 else if (parse_feature_request(features, "side-band"))
 670                         use_sideband = DEFAULT_PACKET_MAX;
 671                 if (parse_feature_request(features, "no-progress"))
 672                         no_progress = 1;
 673                 if (parse_feature_request(features, "include-tag"))
 674                         use_include_tag = 1;
 675
 676                 o = parse_object(sha1_buf);
 677                 if (!o)
 678                         die("git upload-pack: not our ref %s",
 679                             sha1_to_hex(sha1_buf));
 680                 if (!(o->flags & WANTED)) {
 681                         o->flags |= WANTED;
 682                         if (!is_our_ref(o))
 683                                 has_non_tip = 1;
 684                         add_object_array(o, NULL, &want_obj);
 685                 }
 686         }
 687
 688         /*
 689          * We have sent all our refs already, and the other end
 690          * should have chosen out of them. When we are operating
 691          * in the stateless RPC mode, however, their choice may
 692          * have been based on the set of older refs advertised
 693          * by another process that handled the initial request.
 694          */
 695         if (has_non_tip)
 696                 check_non_tip();
 697
 698         if (!use_sideband && daemon_mode)
 699                 no_progress = 1;
 700
 701         if (depth == 0 && shallows.nr == 0)
 702                 return;
 703         if (depth > 0)
 704                 deepen(depth, &shallows);
 705         else
 706                 if (shallows.nr > 0) {
 707                         int i;
 708                         for (i = 0; i < shallows.nr; i++)
 709                                 register_shallow(shallows.objects[i].item->oid.hash);
 710                 }
 711
 712         shallow_nr += shallows.nr;
 713         free(shallows.objects);
 714 }
 715
 716 /* return non-zero if the ref is hidden, otherwise 0 */
 717 static int mark_our_ref(const char *refname, const char *refname_full,
 718                         const struct object_id *oid)
 719 {
 720         struct object *o = lookup_unknown_object(oid->hash);
 721
 722         if (ref_is_hidden(refname, refname_full)) {
 723                 o->flags |= HIDDEN_REF;
 724                 return 1;
 725         }
 726         o->flags |= OUR_REF;
 727         return 0;
 728 }
 729
 730 static int check_ref(const char *refname_full, const struct object_id *oid,
 731                      int flag, void *cb_data)
 732 {
 733         const char *refname = strip_namespace(refname_full);
 734
 735         mark_our_ref(refname, refname_full, oid);
 736         return 0;
 737 }
 738
 739 static void format_symref_info(struct strbuf *buf, struct string_list *symref)
 740 {
 741         struct string_list_item *item;
 742
 743         if (!symref->nr)
 744                 return;
 745         for_each_string_list_item(item, symref)
 746                 strbuf_addf(buf, " symref=%s:%s", item->string, (char *)item->util);
 747 }
 748
 749 static int send_ref(const char *refname, const struct object_id *oid,
 750                     int flag, void *cb_data)
 751 {
 752         static const char *capabilities = "multi_ack thin-pack side-band"
 753                 " side-band-64k ofs-delta shallow no-progress"
 754                 " include-tag multi_ack_detailed";
 755         const char *refname_nons = strip_namespace(refname);
 756         struct object_id peeled;
 757
 758         if (mark_our_ref(refname_nons, refname, oid))
 759                 return 0;
 760
 761         if (capabilities) {
 762                 struct strbuf symref_info = STRBUF_INIT;
 763
 764                 format_symref_info(&symref_info, cb_data);
 765                 packet_write(1, "%s %s%c%s%s%s%s%s agent=%s\n",
 766                              oid_to_hex(oid), refname_nons,
 767                              0, capabilities,
 768                              (allow_unadvertised_object_request & ALLOW_TIP_SHA1) ?
 769                                      " allow-tip-sha1-in-want" : "",
 770                              (allow_unadvertised_object_request & ALLOW_REACHABLE_SHA1) ?
 771                                      " allow-reachable-sha1-in-want" : "",
 772                              stateless_rpc ? " no-done" : "",
 773                              symref_info.buf,
 774                              git_user_agent_sanitized());
 775                 strbuf_release(&symref_info);
 776         } else {
 777                 packet_write(1, "%s %s\n", oid_to_hex(oid), refname_nons);
 778         }
 779         capabilities = NULL;
 780         if (!peel_ref(refname, peeled.hash))
 781                 packet_write(1, "%s %s^{}\n", oid_to_hex(&peeled), refname_nons);
 782         return 0;
 783 }
 784
 785 static int find_symref(const char *refname, const struct object_id *oid,
 786                        int flag, void *cb_data)
 787 {
 788         const char *symref_target;
 789         struct string_list_item *item;
 790         struct object_id unused;
 791
 792         if ((flag & REF_ISSYMREF) == 0)
 793                 return 0;
 794         symref_target = resolve_ref_unsafe(refname, 0, unused.hash, &flag);
 795         if (!symref_target || (flag & REF_ISSYMREF) == 0)
 796                 die("'%s' is a symref but it is not?", refname);
 797         item = string_list_append(cb_data, refname);
 798         item->util = xstrdup(symref_target);
 799         return 0;
 800 }
 801
 802 static void upload_pack(void)
 803 {
 804         struct string_list symref = STRING_LIST_INIT_DUP;
 805
 806         head_ref_namespaced(find_symref, &symref);
 807
 808         if (advertise_refs || !stateless_rpc) {
 809                 reset_timeout();
 810                 head_ref_namespaced(send_ref, &symref);
 811                 for_each_namespaced_ref(send_ref, &symref);
 812                 advertise_shallow_grafts(1);
 813                 packet_flush(1);
 814         } else {
 815                 head_ref_namespaced(check_ref, NULL);
 816                 for_each_namespaced_ref(check_ref, NULL);
 817         }
 818         string_list_clear(&symref, 1);
 819         if (advertise_refs)
 820                 return;
 821
 822         receive_needs();
 823         if (want_obj.nr) {
 824                 get_common_commits();
 825                 create_pack_file();
 826         }
 827 }
 828
 829 static int upload_pack_config(const char *var, const char *value, void *unused)
 830 {
 831         if (!strcmp("uploadpack.allowtipsha1inwant", var)) {
 832                 if (git_config_bool(var, value))
 833                         allow_unadvertised_object_request |= ALLOW_TIP_SHA1;
 834                 else
 835                         allow_unadvertised_object_request &= ~ALLOW_TIP_SHA1;
 836         } else if (!strcmp("uploadpack.allowreachablesha1inwant", var)) {
 837                 if (git_config_bool(var, value))
 838                         allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
 839                 else
 840                         allow_unadvertised_object_request &= ~ALLOW_REACHABLE_SHA1;
 841         } else if (!strcmp("uploadpack.keepalive", var)) {
 842                 keepalive = git_config_int(var, value);
 843                 if (!keepalive)
 844                         keepalive = -1;
 845         }
 846         return parse_hide_refs_config(var, value, "uploadpack");
 847 }
 848
 849 int main(int argc, char **argv)
 850 {
 851         char *dir;
 852         int i;
 853         int strict = 0;
 854
 855         git_setup_gettext();
 856
 857         packet_trace_identity("upload-pack");
 858         git_extract_argv0_path(argv[0]);
 859         check_replace_refs = 0;
 860
 861         for (i = 1; i < argc; i++) {
 862                 char *arg = argv[i];
 863
 864                 if (arg[0] != '-')
 865                         break;
 866                 if (!strcmp(arg, "--advertise-refs")) {
 867                         advertise_refs = 1;
 868                         continue;
 869                 }
 870                 if (!strcmp(arg, "--stateless-rpc")) {
 871                         stateless_rpc = 1;
 872                         continue;
 873                 }
 874                 if (!strcmp(arg, "--strict")) {
 875                         strict = 1;
 876                         continue;
 877                 }
 878                 if (starts_with(arg, "--timeout=")) {
 879                         timeout = atoi(arg+10);
 880                         daemon_mode = 1;
 881                         continue;
 882                 }
 883                 if (!strcmp(arg, "--")) {
 884                         i++;
 885                         break;
 886                 }
 887         }
 888
 889         if (i != argc-1)
 890                 usage(upload_pack_usage);
 891
 892         setup_path();
 893
 894         dir = argv[i];
 895
 896         if (!enter_repo(dir, strict))
 897                 die("'%s' does not appear to be a git repository", dir);
 898
 899         git_config(upload_pack_config, NULL);
 900         upload_pack();
 901         return 0;
 902 }