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