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 #include "argv-array.h"
  19 #include "prio-queue.h"
  20
  21 static const char * const upload_pack_usage[] = {
  22         N_("git upload-pack [<options>] <dir>"),
  23         NULL
  24 };
  25
  26 /* Remember to update object flag allocation in object.h */
  27 #define THEY_HAVE       (1u << 11)
  28 #define OUR_REF         (1u << 12)
  29 #define WANTED          (1u << 13)
  30 #define COMMON_KNOWN    (1u << 14)
  31 #define REACHABLE       (1u << 15)
  32
  33 #define SHALLOW         (1u << 16)
  34 #define NOT_SHALLOW     (1u << 17)
  35 #define CLIENT_SHALLOW  (1u << 18)
  36 #define HIDDEN_REF      (1u << 19)
  37
  38 static timestamp_t oldest_have;
  39
  40 static int deepen_relative;
  41 static int multi_ack;
  42 static int no_done;
  43 static int use_thin_pack, use_ofs_delta, use_include_tag;
  44 static int no_progress, daemon_mode;
  45 /* Allow specifying sha1 if it is a ref tip. */
  46 #define ALLOW_TIP_SHA1  01
  47 /* Allow request of a sha1 if it is reachable from a ref (possibly hidden ref). */
  48 #define ALLOW_REACHABLE_SHA1    02
  49 /* Allow request of any sha1. Implies ALLOW_TIP_SHA1 and ALLOW_REACHABLE_SHA1. */
  50 #define ALLOW_ANY_SHA1  07
  51 static unsigned int allow_unadvertised_object_request;
  52 static int shallow_nr;
  53 static struct object_array have_obj;
  54 static struct object_array want_obj;
  55 static struct object_array extra_edge_obj;
  56 static unsigned int timeout;
  57 static int keepalive = 5;
  58 /* 0 for no sideband,
  59  * otherwise maximum packet size (up to 65520 bytes).
  60  */
  61 static int use_sideband;
  62 static int advertise_refs;
  63 static int stateless_rpc;
  64 static const char *pack_objects_hook;
  65
  66 static void reset_timeout(void)
  67 {
  68         alarm(timeout);
  69 }
  70
  71 static void send_client_data(int fd, const char *data, ssize_t sz)
  72 {
  73         if (use_sideband) {
  74                 send_sideband(1, fd, data, sz, use_sideband);
  75                 return;
  76         }
  77         if (fd == 3)
  78                 /* emergency quit */
  79                 fd = 2;
  80         if (fd == 2) {
  81                 /* XXX: are we happy to lose stuff here? */
  82                 xwrite(fd, data, sz);
  83                 return;
  84         }
  85         write_or_die(fd, data, sz);
  86 }
  87
  88 static int write_one_shallow(const struct commit_graft *graft, void *cb_data)
  89 {
  90         FILE *fp = cb_data;
  91         if (graft->nr_parent == -1)
  92                 fprintf(fp, "--shallow %s\n", oid_to_hex(&graft->oid));
  93         return 0;
  94 }
  95
  96 static void create_pack_file(void)
  97 {
  98         struct child_process pack_objects = CHILD_PROCESS_INIT;
  99         char data[8193], progress[128];
 100         char abort_msg[] = "aborting due to possible repository "
 101                 "corruption on the remote side.";
 102         int buffered = -1;
 103         ssize_t sz;
 104         int i;
 105         FILE *pipe_fd;
 106
 107         if (!pack_objects_hook)
 108                 pack_objects.git_cmd = 1;
 109         else {
 110                 argv_array_push(&pack_objects.args, pack_objects_hook);
 111                 argv_array_push(&pack_objects.args, "git");
 112                 pack_objects.use_shell = 1;
 113         }
 114
 115         if (shallow_nr) {
 116                 argv_array_push(&pack_objects.args, "--shallow-file");
 117                 argv_array_push(&pack_objects.args, "");
 118         }
 119         argv_array_push(&pack_objects.args, "pack-objects");
 120         argv_array_push(&pack_objects.args, "--revs");
 121         if (use_thin_pack)
 122                 argv_array_push(&pack_objects.args, "--thin");
 123
 124         argv_array_push(&pack_objects.args, "--stdout");
 125         if (shallow_nr)
 126                 argv_array_push(&pack_objects.args, "--shallow");
 127         if (!no_progress)
 128                 argv_array_push(&pack_objects.args, "--progress");
 129         if (use_ofs_delta)
 130                 argv_array_push(&pack_objects.args, "--delta-base-offset");
 131         if (use_include_tag)
 132                 argv_array_push(&pack_objects.args, "--include-tag");
 133
 134         pack_objects.in = -1;
 135         pack_objects.out = -1;
 136         pack_objects.err = -1;
 137
 138         if (start_command(&pack_objects))
 139                 die("git upload-pack: unable to fork git-pack-objects");
 140
 141         pipe_fd = xfdopen(pack_objects.in, "w");
 142
 143         if (shallow_nr)
 144                 for_each_commit_graft(write_one_shallow, pipe_fd);
 145
 146         for (i = 0; i < want_obj.nr; i++)
 147                 fprintf(pipe_fd, "%s\n",
 148                         oid_to_hex(&want_obj.objects[i].item->oid));
 149         fprintf(pipe_fd, "--not\n");
 150         for (i = 0; i < have_obj.nr; i++)
 151                 fprintf(pipe_fd, "%s\n",
 152                         oid_to_hex(&have_obj.objects[i].item->oid));
 153         for (i = 0; i < extra_edge_obj.nr; i++)
 154                 fprintf(pipe_fd, "%s\n",
 155                         oid_to_hex(&extra_edge_obj.objects[i].item->oid));
 156         fprintf(pipe_fd, "\n");
 157         fflush(pipe_fd);
 158         fclose(pipe_fd);
 159
 160         /* We read from pack_objects.err to capture stderr output for
 161          * progress bar, and pack_objects.out to capture the pack data.
 162          */
 163
 164         while (1) {
 165                 struct pollfd pfd[2];
 166                 int pe, pu, pollsize;
 167                 int ret;
 168
 169                 reset_timeout();
 170
 171                 pollsize = 0;
 172                 pe = pu = -1;
 173
 174                 if (0 <= pack_objects.out) {
 175                         pfd[pollsize].fd = pack_objects.out;
 176                         pfd[pollsize].events = POLLIN;
 177                         pu = pollsize;
 178                         pollsize++;
 179                 }
 180                 if (0 <= pack_objects.err) {
 181                         pfd[pollsize].fd = pack_objects.err;
 182                         pfd[pollsize].events = POLLIN;
 183                         pe = pollsize;
 184                         pollsize++;
 185                 }
 186
 187                 if (!pollsize)
 188                         break;
 189
 190                 ret = poll(pfd, pollsize,
 191                         keepalive < 0 ? -1 : 1000 * keepalive);
 192
 193                 if (ret < 0) {
 194                         if (errno != EINTR) {
 195                                 error_errno("poll failed, resuming");
 196                                 sleep(1);
 197                         }
 198                         continue;
 199                 }
 200                 if (0 <= pe && (pfd[pe].revents & (POLLIN|POLLHUP))) {
 201                         /* Status ready; we ship that in the side-band
 202                          * or dump to the standard error.
 203                          */
 204                         sz = xread(pack_objects.err, progress,
 205                                   sizeof(progress));
 206                         if (0 < sz)
 207                                 send_client_data(2, progress, sz);
 208                         else if (sz == 0) {
 209                                 close(pack_objects.err);
 210                                 pack_objects.err = -1;
 211                         }
 212                         else
 213                                 goto fail;
 214                         /* give priority to status messages */
 215                         continue;
 216                 }
 217                 if (0 <= pu && (pfd[pu].revents & (POLLIN|POLLHUP))) {
 218                         /* Data ready; we keep the last byte to ourselves
 219                          * in case we detect broken rev-list, so that we
 220                          * can leave the stream corrupted.  This is
 221                          * unfortunate -- unpack-objects would happily
 222                          * accept a valid packdata with trailing garbage,
 223                          * so appending garbage after we pass all the
 224                          * pack data is not good enough to signal
 225                          * breakage to downstream.
 226                          */
 227                         char *cp = data;
 228                         ssize_t outsz = 0;
 229                         if (0 <= buffered) {
 230                                 *cp++ = buffered;
 231                                 outsz++;
 232                         }
 233                         sz = xread(pack_objects.out, cp,
 234                                   sizeof(data) - outsz);
 235                         if (0 < sz)
 236                                 ;
 237                         else if (sz == 0) {
 238                                 close(pack_objects.out);
 239                                 pack_objects.out = -1;
 240                         }
 241                         else
 242                                 goto fail;
 243                         sz += outsz;
 244                         if (1 < sz) {
 245                                 buffered = data[sz-1] & 0xFF;
 246                                 sz--;
 247                         }
 248                         else
 249                                 buffered = -1;
 250                         send_client_data(1, data, sz);
 251                 }
 252
 253                 /*
 254                  * We hit the keepalive timeout without saying anything; send
 255                  * an empty message on the data sideband just to let the other
 256                  * side know we're still working on it, but don't have any data
 257                  * yet.
 258                  *
 259                  * If we don't have a sideband channel, there's no room in the
 260                  * protocol to say anything, so those clients are just out of
 261                  * luck.
 262                  */
 263                 if (!ret && use_sideband) {
 264                         static const char buf[] = "0005\1";
 265                         write_or_die(1, buf, 5);
 266                 }
 267         }
 268
 269         if (finish_command(&pack_objects)) {
 270                 error("git upload-pack: git-pack-objects died with error.");
 271                 goto fail;
 272         }
 273
 274         /* flush the data */
 275         if (0 <= buffered) {
 276                 data[0] = buffered;
 277                 send_client_data(1, data, 1);
 278                 fprintf(stderr, "flushed.\n");
 279         }
 280         if (use_sideband)
 281                 packet_flush(1);
 282         return;
 283
 284  fail:
 285         send_client_data(3, abort_msg, sizeof(abort_msg));
 286         die("git upload-pack: %s", abort_msg);
 287 }
 288
 289 static int got_sha1(const char *hex, unsigned char *sha1)
 290 {
 291         struct object *o;
 292         int we_knew_they_have = 0;
 293
 294         if (get_sha1_hex(hex, sha1))
 295                 die("git upload-pack: expected SHA1 object, got '%s'", hex);
 296         if (!has_sha1_file(sha1))
 297                 return -1;
 298
 299         o = parse_object(sha1);
 300         if (!o)
 301                 die("oops (%s)", sha1_to_hex(sha1));
 302         if (o->type == OBJ_COMMIT) {
 303                 struct commit_list *parents;
 304                 struct commit *commit = (struct commit *)o;
 305                 if (o->flags & THEY_HAVE)
 306                         we_knew_they_have = 1;
 307                 else
 308                         o->flags |= THEY_HAVE;
 309                 if (!oldest_have || (commit->date < oldest_have))
 310                         oldest_have = commit->date;
 311                 for (parents = commit->parents;
 312                      parents;
 313                      parents = parents->next)
 314                         parents->item->object.flags |= THEY_HAVE;
 315         }
 316         if (!we_knew_they_have) {
 317                 add_object_array(o, NULL, &have_obj);
 318                 return 1;
 319         }
 320         return 0;
 321 }
 322
 323 static int reachable(struct commit *want)
 324 {
 325         struct prio_queue work = { compare_commits_by_commit_date };
 326
 327         prio_queue_put(&work, want);
 328         while (work.nr) {
 329                 struct commit_list *list;
 330                 struct commit *commit = prio_queue_get(&work);
 331
 332                 if (commit->object.flags & THEY_HAVE) {
 333                         want->object.flags |= COMMON_KNOWN;
 334                         break;
 335                 }
 336                 if (!commit->object.parsed)
 337                         parse_object(commit->object.oid.hash);
 338                 if (commit->object.flags & REACHABLE)
 339                         continue;
 340                 commit->object.flags |= REACHABLE;
 341                 if (commit->date < oldest_have)
 342                         continue;
 343                 for (list = commit->parents; list; list = list->next) {
 344                         struct commit *parent = list->item;
 345                         if (!(parent->object.flags & REACHABLE))
 346                                 prio_queue_put(&work, parent);
 347                 }
 348         }
 349         want->object.flags |= REACHABLE;
 350         clear_commit_marks(want, REACHABLE);
 351         clear_prio_queue(&work);
 352         return (want->object.flags & COMMON_KNOWN);
 353 }
 354
 355 static int ok_to_give_up(void)
 356 {
 357         int i;
 358
 359         if (!have_obj.nr)
 360                 return 0;
 361
 362         for (i = 0; i < want_obj.nr; i++) {
 363                 struct object *want = want_obj.objects[i].item;
 364
 365                 if (want->flags & COMMON_KNOWN)
 366                         continue;
 367                 want = deref_tag(want, "a want line", 0);
 368                 if (!want || want->type != OBJ_COMMIT) {
 369                         /* no way to tell if this is reachable by
 370                          * looking at the ancestry chain alone, so
 371                          * leave a note to ourselves not to worry about
 372                          * this object anymore.
 373                          */
 374                         want_obj.objects[i].item->flags |= COMMON_KNOWN;
 375                         continue;
 376                 }
 377                 if (!reachable((struct commit *)want))
 378                         return 0;
 379         }
 380         return 1;
 381 }
 382
 383 static int get_common_commits(void)
 384 {
 385         unsigned char sha1[20];
 386         char last_hex[41];
 387         int got_common = 0;
 388         int got_other = 0;
 389         int sent_ready = 0;
 390
 391         save_commit_buffer = 0;
 392
 393         for (;;) {
 394                 char *line = packet_read_line(0, NULL);
 395                 const char *arg;
 396
 397                 reset_timeout();
 398
 399                 if (!line) {
 400                         if (multi_ack == 2 && got_common
 401                             && !got_other && ok_to_give_up()) {
 402                                 sent_ready = 1;
 403                                 packet_write_fmt(1, "ACK %s ready\n", last_hex);
 404                         }
 405                         if (have_obj.nr == 0 || multi_ack)
 406                                 packet_write_fmt(1, "NAK\n");
 407
 408                         if (no_done && sent_ready) {
 409                                 packet_write_fmt(1, "ACK %s\n", last_hex);
 410                                 return 0;
 411                         }
 412                         if (stateless_rpc)
 413                                 exit(0);
 414                         got_common = 0;
 415                         got_other = 0;
 416                         continue;
 417                 }
 418                 if (skip_prefix(line, "have ", &arg)) {
 419                         switch (got_sha1(arg, sha1)) {
 420                         case -1: /* they have what we do not */
 421                                 got_other = 1;
 422                                 if (multi_ack && ok_to_give_up()) {
 423                                         const char *hex = sha1_to_hex(sha1);
 424                                         if (multi_ack == 2) {
 425                                                 sent_ready = 1;
 426                                                 packet_write_fmt(1, "ACK %s ready\n", hex);
 427                                         } else
 428                                                 packet_write_fmt(1, "ACK %s continue\n", hex);
 429                                 }
 430                                 break;
 431                         default:
 432                                 got_common = 1;
 433                                 memcpy(last_hex, sha1_to_hex(sha1), 41);
 434                                 if (multi_ack == 2)
 435                                         packet_write_fmt(1, "ACK %s common\n", last_hex);
 436                                 else if (multi_ack)
 437                                         packet_write_fmt(1, "ACK %s continue\n", last_hex);
 438                                 else if (have_obj.nr == 1)
 439                                         packet_write_fmt(1, "ACK %s\n", last_hex);
 440                                 break;
 441                         }
 442                         continue;
 443                 }
 444                 if (!strcmp(line, "done")) {
 445                         if (have_obj.nr > 0) {
 446                                 if (multi_ack)
 447                                         packet_write_fmt(1, "ACK %s\n", last_hex);
 448                                 return 0;
 449                         }
 450                         packet_write_fmt(1, "NAK\n");
 451                         return -1;
 452                 }
 453                 die("git upload-pack: expected SHA1 list, got '%s'", line);
 454         }
 455 }
 456
 457 static int is_our_ref(struct object *o)
 458 {
 459         int allow_hidden_ref = (allow_unadvertised_object_request &
 460                         (ALLOW_TIP_SHA1 | ALLOW_REACHABLE_SHA1));
 461         return o->flags & ((allow_hidden_ref ? HIDDEN_REF : 0) | OUR_REF);
 462 }
 463
 464 /*
 465  * on successful case, it's up to the caller to close cmd->out
 466  */
 467 static int do_reachable_revlist(struct child_process *cmd,
 468                                 struct object_array *src,
 469                                 struct object_array *reachable)
 470 {
 471         static const char *argv[] = {
 472                 "rev-list", "--stdin", NULL,
 473         };
 474         struct object *o;
 475         char namebuf[42]; /* ^ + SHA-1 + LF */
 476         int i;
 477
 478         cmd->argv = argv;
 479         cmd->git_cmd = 1;
 480         cmd->no_stderr = 1;
 481         cmd->in = -1;
 482         cmd->out = -1;
 483
 484         /*
 485          * If the next rev-list --stdin encounters an unknown commit,
 486          * it terminates, which will cause SIGPIPE in the write loop
 487          * below.
 488          */
 489         sigchain_push(SIGPIPE, SIG_IGN);
 490
 491         if (start_command(cmd))
 492                 goto error;
 493
 494         namebuf[0] = '^';
 495         namebuf[41] = '\n';
 496         for (i = get_max_object_index(); 0 < i; ) {
 497                 o = get_indexed_object(--i);
 498                 if (!o)
 499                         continue;
 500                 if (reachable && o->type == OBJ_COMMIT)
 501                         o->flags &= ~TMP_MARK;
 502                 if (!is_our_ref(o))
 503                         continue;
 504                 memcpy(namebuf + 1, oid_to_hex(&o->oid), GIT_SHA1_HEXSZ);
 505                 if (write_in_full(cmd->in, namebuf, 42) < 0)
 506                         goto error;
 507         }
 508         namebuf[40] = '\n';
 509         for (i = 0; i < src->nr; i++) {
 510                 o = src->objects[i].item;
 511                 if (is_our_ref(o)) {
 512                         if (reachable)
 513                                 add_object_array(o, NULL, reachable);
 514                         continue;
 515                 }
 516                 if (reachable && o->type == OBJ_COMMIT)
 517                         o->flags |= TMP_MARK;
 518                 memcpy(namebuf, oid_to_hex(&o->oid), GIT_SHA1_HEXSZ);
 519                 if (write_in_full(cmd->in, namebuf, 41) < 0)
 520                         goto error;
 521         }
 522         close(cmd->in);
 523         cmd->in = -1;
 524         sigchain_pop(SIGPIPE);
 525
 526         return 0;
 527
 528 error:
 529         sigchain_pop(SIGPIPE);
 530
 531         if (cmd->in >= 0)
 532                 close(cmd->in);
 533         if (cmd->out >= 0)
 534                 close(cmd->out);
 535         return -1;
 536 }
 537
 538 static int get_reachable_list(struct object_array *src,
 539                               struct object_array *reachable)
 540 {
 541         struct child_process cmd = CHILD_PROCESS_INIT;
 542         int i;
 543         struct object *o;
 544         char namebuf[42]; /* ^ + SHA-1 + LF */
 545
 546         if (do_reachable_revlist(&cmd, src, reachable) < 0)
 547                 return -1;
 548
 549         while ((i = read_in_full(cmd.out, namebuf, 41)) == 41) {
 550                 struct object_id sha1;
 551
 552                 if (namebuf[40] != '\n' || get_oid_hex(namebuf, &sha1))
 553                         break;
 554
 555                 o = lookup_object(sha1.hash);
 556                 if (o && o->type == OBJ_COMMIT) {
 557                         o->flags &= ~TMP_MARK;
 558                 }
 559         }
 560         for (i = get_max_object_index(); 0 < i; i--) {
 561                 o = get_indexed_object(i - 1);
 562                 if (o && o->type == OBJ_COMMIT &&
 563                     (o->flags & TMP_MARK)) {
 564                         add_object_array(o, NULL, reachable);
 565                                 o->flags &= ~TMP_MARK;
 566                 }
 567         }
 568         close(cmd.out);
 569
 570         if (finish_command(&cmd))
 571                 return -1;
 572
 573         return 0;
 574 }
 575
 576 static int has_unreachable(struct object_array *src)
 577 {
 578         struct child_process cmd = CHILD_PROCESS_INIT;
 579         char buf[1];
 580         int i;
 581
 582         if (do_reachable_revlist(&cmd, src, NULL) < 0)
 583                 return 1;
 584
 585         /*
 586          * The commits out of the rev-list are not ancestors of
 587          * our ref.
 588          */
 589         i = read_in_full(cmd.out, buf, 1);
 590         if (i)
 591                 goto error;
 592         close(cmd.out);
 593         cmd.out = -1;
 594
 595         /*
 596          * rev-list may have died by encountering a bad commit
 597          * in the history, in which case we do want to bail out
 598          * even when it showed no commit.
 599          */
 600         if (finish_command(&cmd))
 601                 goto error;
 602
 603         /* All the non-tip ones are ancestors of what we advertised */
 604         return 0;
 605
 606 error:
 607         sigchain_pop(SIGPIPE);
 608         if (cmd.out >= 0)
 609                 close(cmd.out);
 610         return 1;
 611 }
 612
 613 static void check_non_tip(void)
 614 {
 615         int i;
 616
 617         /*
 618          * In the normal in-process case without
 619          * uploadpack.allowReachableSHA1InWant,
 620          * non-tip requests can never happen.
 621          */
 622         if (!stateless_rpc && !(allow_unadvertised_object_request & ALLOW_REACHABLE_SHA1))
 623                 goto error;
 624         if (!has_unreachable(&want_obj))
 625                 /* All the non-tip ones are ancestors of what we advertised */
 626                 return;
 627
 628 error:
 629         /* Pick one of them (we know there at least is one) */
 630         for (i = 0; i < want_obj.nr; i++) {
 631                 struct object *o = want_obj.objects[i].item;
 632                 if (!is_our_ref(o))
 633                         die("git upload-pack: not our ref %s",
 634                             oid_to_hex(&o->oid));
 635         }
 636 }
 637
 638 static void send_shallow(struct commit_list *result)
 639 {
 640         while (result) {
 641                 struct object *object = &result->item->object;
 642                 if (!(object->flags & (CLIENT_SHALLOW|NOT_SHALLOW))) {
 643                         packet_write_fmt(1, "shallow %s",
 644                                          oid_to_hex(&object->oid));
 645                         register_shallow(object->oid.hash);
 646                         shallow_nr++;
 647                 }
 648                 result = result->next;
 649         }
 650 }
 651
 652 static void send_unshallow(const struct object_array *shallows)
 653 {
 654         int i;
 655
 656         for (i = 0; i < shallows->nr; i++) {
 657                 struct object *object = shallows->objects[i].item;
 658                 if (object->flags & NOT_SHALLOW) {
 659                         struct commit_list *parents;
 660                         packet_write_fmt(1, "unshallow %s",
 661                                          oid_to_hex(&object->oid));
 662                         object->flags &= ~CLIENT_SHALLOW;
 663                         /*
 664                          * We want to _register_ "object" as shallow, but we
 665                          * also need to traverse object's parents to deepen a
 666                          * shallow clone. Unregister it for now so we can
 667                          * parse and add the parents to the want list, then
 668                          * re-register it.
 669                          */
 670                         unregister_shallow(object->oid.hash);
 671                         object->parsed = 0;
 672                         parse_commit_or_die((struct commit *)object);
 673                         parents = ((struct commit *)object)->parents;
 674                         while (parents) {
 675                                 add_object_array(&parents->item->object,
 676                                                  NULL, &want_obj);
 677                                 parents = parents->next;
 678                         }
 679                         add_object_array(object, NULL, &extra_edge_obj);
 680                 }
 681                 /* make sure commit traversal conforms to client */
 682                 register_shallow(object->oid.hash);
 683         }
 684 }
 685
 686 static void deepen(int depth, int deepen_relative,
 687                    struct object_array *shallows)
 688 {
 689         if (depth == INFINITE_DEPTH && !is_repository_shallow()) {
 690                 int i;
 691
 692                 for (i = 0; i < shallows->nr; i++) {
 693                         struct object *object = shallows->objects[i].item;
 694                         object->flags |= NOT_SHALLOW;
 695                 }
 696         } else if (deepen_relative) {
 697                 struct object_array reachable_shallows = OBJECT_ARRAY_INIT;
 698                 struct commit_list *result;
 699
 700                 get_reachable_list(shallows, &reachable_shallows);
 701                 result = get_shallow_commits(&reachable_shallows,
 702                                              depth + 1,
 703                                              SHALLOW, NOT_SHALLOW);
 704                 send_shallow(result);
 705                 free_commit_list(result);
 706                 object_array_clear(&reachable_shallows);
 707         } else {
 708                 struct commit_list *result;
 709
 710                 result = get_shallow_commits(&want_obj, depth,
 711                                              SHALLOW, NOT_SHALLOW);
 712                 send_shallow(result);
 713                 free_commit_list(result);
 714         }
 715
 716         send_unshallow(shallows);
 717         packet_flush(1);
 718 }
 719
 720 static void deepen_by_rev_list(int ac, const char **av,
 721                                struct object_array *shallows)
 722 {
 723         struct commit_list *result;
 724
 725         result = get_shallow_commits_by_rev_list(ac, av, SHALLOW, NOT_SHALLOW);
 726         send_shallow(result);
 727         free_commit_list(result);
 728         send_unshallow(shallows);
 729         packet_flush(1);
 730 }
 731
 732 static void receive_needs(void)
 733 {
 734         struct object_array shallows = OBJECT_ARRAY_INIT;
 735         struct string_list deepen_not = STRING_LIST_INIT_DUP;
 736         int depth = 0;
 737         int has_non_tip = 0;
 738         timestamp_t deepen_since = 0;
 739         int deepen_rev_list = 0;
 740
 741         shallow_nr = 0;
 742         for (;;) {
 743                 struct object *o;
 744                 const char *features;
 745                 unsigned char sha1_buf[20];
 746                 char *line = packet_read_line(0, NULL);
 747                 const char *arg;
 748
 749                 reset_timeout();
 750                 if (!line)
 751                         break;
 752
 753                 if (skip_prefix(line, "shallow ", &arg)) {
 754                         unsigned char sha1[20];
 755                         struct object *object;
 756                         if (get_sha1_hex(arg, sha1))
 757                                 die("invalid shallow line: %s", line);
 758                         object = parse_object(sha1);
 759                         if (!object)
 760                                 continue;
 761                         if (object->type != OBJ_COMMIT)
 762                                 die("invalid shallow object %s", sha1_to_hex(sha1));
 763                         if (!(object->flags & CLIENT_SHALLOW)) {
 764                                 object->flags |= CLIENT_SHALLOW;
 765                                 add_object_array(object, NULL, &shallows);
 766                         }
 767                         continue;
 768                 }
 769                 if (skip_prefix(line, "deepen ", &arg)) {
 770                         char *end = NULL;
 771                         depth = strtol(arg, &end, 0);
 772                         if (!end || *end || depth <= 0)
 773                                 die("Invalid deepen: %s", line);
 774                         continue;
 775                 }
 776                 if (skip_prefix(line, "deepen-since ", &arg)) {
 777                         char *end = NULL;
 778                         deepen_since = parse_timestamp(arg, &end, 0);
 779                         if (!end || *end || !deepen_since ||
 780                             /* revisions.c's max_age -1 is special */
 781                             deepen_since == -1)
 782                                 die("Invalid deepen-since: %s", line);
 783                         deepen_rev_list = 1;
 784                         continue;
 785                 }
 786                 if (skip_prefix(line, "deepen-not ", &arg)) {
 787                         char *ref = NULL;
 788                         unsigned char sha1[20];
 789                         if (expand_ref(arg, strlen(arg), sha1, &ref) != 1)
 790                                 die("git upload-pack: ambiguous deepen-not: %s", line);
 791                         string_list_append(&deepen_not, ref);
 792                         free(ref);
 793                         deepen_rev_list = 1;
 794                         continue;
 795                 }
 796                 if (!skip_prefix(line, "want ", &arg) ||
 797                     get_sha1_hex(arg, sha1_buf))
 798                         die("git upload-pack: protocol error, "
 799                             "expected to get sha, not '%s'", line);
 800
 801                 features = arg + 40;
 802
 803                 if (parse_feature_request(features, "deepen-relative"))
 804                         deepen_relative = 1;
 805                 if (parse_feature_request(features, "multi_ack_detailed"))
 806                         multi_ack = 2;
 807                 else if (parse_feature_request(features, "multi_ack"))
 808                         multi_ack = 1;
 809                 if (parse_feature_request(features, "no-done"))
 810                         no_done = 1;
 811                 if (parse_feature_request(features, "thin-pack"))
 812                         use_thin_pack = 1;
 813                 if (parse_feature_request(features, "ofs-delta"))
 814                         use_ofs_delta = 1;
 815                 if (parse_feature_request(features, "side-band-64k"))
 816                         use_sideband = LARGE_PACKET_MAX;
 817                 else if (parse_feature_request(features, "side-band"))
 818                         use_sideband = DEFAULT_PACKET_MAX;
 819                 if (parse_feature_request(features, "no-progress"))
 820                         no_progress = 1;
 821                 if (parse_feature_request(features, "include-tag"))
 822                         use_include_tag = 1;
 823
 824                 o = parse_object(sha1_buf);
 825                 if (!o) {
 826                         packet_write_fmt(1,
 827                                          "ERR upload-pack: not our ref %s",
 828                                          sha1_to_hex(sha1_buf));
 829                         die("git upload-pack: not our ref %s",
 830                             sha1_to_hex(sha1_buf));
 831                 }
 832                 if (!(o->flags & WANTED)) {
 833                         o->flags |= WANTED;
 834                         if (!((allow_unadvertised_object_request & ALLOW_ANY_SHA1) == ALLOW_ANY_SHA1
 835                               || is_our_ref(o)))
 836                                 has_non_tip = 1;
 837                         add_object_array(o, NULL, &want_obj);
 838                 }
 839         }
 840
 841         /*
 842          * We have sent all our refs already, and the other end
 843          * should have chosen out of them. When we are operating
 844          * in the stateless RPC mode, however, their choice may
 845          * have been based on the set of older refs advertised
 846          * by another process that handled the initial request.
 847          */
 848         if (has_non_tip)
 849                 check_non_tip();
 850
 851         if (!use_sideband && daemon_mode)
 852                 no_progress = 1;
 853
 854         if (depth == 0 && !deepen_rev_list && shallows.nr == 0)
 855                 return;
 856         if (depth > 0 && deepen_rev_list)
 857                 die("git upload-pack: deepen and deepen-since (or deepen-not) cannot be used together");
 858         if (depth > 0)
 859                 deepen(depth, deepen_relative, &shallows);
 860         else if (deepen_rev_list) {
 861                 struct argv_array av = ARGV_ARRAY_INIT;
 862                 int i;
 863
 864                 argv_array_push(&av, "rev-list");
 865                 if (deepen_since)
 866                         argv_array_pushf(&av, "--max-age=%"PRItime, deepen_since);
 867                 if (deepen_not.nr) {
 868                         argv_array_push(&av, "--not");
 869                         for (i = 0; i < deepen_not.nr; i++) {
 870                                 struct string_list_item *s = deepen_not.items + i;
 871                                 argv_array_push(&av, s->string);
 872                         }
 873                         argv_array_push(&av, "--not");
 874                 }
 875                 for (i = 0; i < want_obj.nr; i++) {
 876                         struct object *o = want_obj.objects[i].item;
 877                         argv_array_push(&av, oid_to_hex(&o->oid));
 878                 }
 879                 deepen_by_rev_list(av.argc, av.argv, &shallows);
 880                 argv_array_clear(&av);
 881         }
 882         else
 883                 if (shallows.nr > 0) {
 884                         int i;
 885                         for (i = 0; i < shallows.nr; i++)
 886                                 register_shallow(shallows.objects[i].item->oid.hash);
 887                 }
 888
 889         shallow_nr += shallows.nr;
 890         free(shallows.objects);
 891 }
 892
 893 /* return non-zero if the ref is hidden, otherwise 0 */
 894 static int mark_our_ref(const char *refname, const char *refname_full,
 895                         const struct object_id *oid)
 896 {
 897         struct object *o = lookup_unknown_object(oid->hash);
 898
 899         if (ref_is_hidden(refname, refname_full)) {
 900                 o->flags |= HIDDEN_REF;
 901                 return 1;
 902         }
 903         o->flags |= OUR_REF;
 904         return 0;
 905 }
 906
 907 static int check_ref(const char *refname_full, const struct object_id *oid,
 908                      int flag, void *cb_data)
 909 {
 910         const char *refname = strip_namespace(refname_full);
 911
 912         mark_our_ref(refname, refname_full, oid);
 913         return 0;
 914 }
 915
 916 static void format_symref_info(struct strbuf *buf, struct string_list *symref)
 917 {
 918         struct string_list_item *item;
 919
 920         if (!symref->nr)
 921                 return;
 922         for_each_string_list_item(item, symref)
 923                 strbuf_addf(buf, " symref=%s:%s", item->string, (char *)item->util);
 924 }
 925
 926 static int send_ref(const char *refname, const struct object_id *oid,
 927                     int flag, void *cb_data)
 928 {
 929         static const char *capabilities = "multi_ack thin-pack side-band"
 930                 " side-band-64k ofs-delta shallow deepen-since deepen-not"
 931                 " deepen-relative no-progress include-tag multi_ack_detailed";
 932         const char *refname_nons = strip_namespace(refname);
 933         struct object_id peeled;
 934
 935         if (mark_our_ref(refname_nons, refname, oid))
 936                 return 0;
 937
 938         if (capabilities) {
 939                 struct strbuf symref_info = STRBUF_INIT;
 940
 941                 format_symref_info(&symref_info, cb_data);
 942                 packet_write_fmt(1, "%s %s%c%s%s%s%s%s agent=%s\n",
 943                              oid_to_hex(oid), refname_nons,
 944                              0, capabilities,
 945                              (allow_unadvertised_object_request & ALLOW_TIP_SHA1) ?
 946                                      " allow-tip-sha1-in-want" : "",
 947                              (allow_unadvertised_object_request & ALLOW_REACHABLE_SHA1) ?
 948                                      " allow-reachable-sha1-in-want" : "",
 949                              stateless_rpc ? " no-done" : "",
 950                              symref_info.buf,
 951                              git_user_agent_sanitized());
 952                 strbuf_release(&symref_info);
 953         } else {
 954                 packet_write_fmt(1, "%s %s\n", oid_to_hex(oid), refname_nons);
 955         }
 956         capabilities = NULL;
 957         if (!peel_ref(refname, peeled.hash))
 958                 packet_write_fmt(1, "%s %s^{}\n", oid_to_hex(&peeled), refname_nons);
 959         return 0;
 960 }
 961
 962 static int find_symref(const char *refname, const struct object_id *oid,
 963                        int flag, void *cb_data)
 964 {
 965         const char *symref_target;
 966         struct string_list_item *item;
 967         struct object_id unused;
 968
 969         if ((flag & REF_ISSYMREF) == 0)
 970                 return 0;
 971         symref_target = resolve_ref_unsafe(refname, 0, unused.hash, &flag);
 972         if (!symref_target || (flag & REF_ISSYMREF) == 0)
 973                 die("'%s' is a symref but it is not?", refname);
 974         item = string_list_append(cb_data, refname);
 975         item->util = xstrdup(symref_target);
 976         return 0;
 977 }
 978
 979 static void upload_pack(void)
 980 {
 981         struct string_list symref = STRING_LIST_INIT_DUP;
 982
 983         head_ref_namespaced(find_symref, &symref);
 984
 985         if (advertise_refs || !stateless_rpc) {
 986                 reset_timeout();
 987                 head_ref_namespaced(send_ref, &symref);
 988                 for_each_namespaced_ref(send_ref, &symref);
 989                 advertise_shallow_grafts(1);
 990                 packet_flush(1);
 991         } else {
 992                 head_ref_namespaced(check_ref, NULL);
 993                 for_each_namespaced_ref(check_ref, NULL);
 994         }
 995         string_list_clear(&symref, 1);
 996         if (advertise_refs)
 997                 return;
 998
 999         receive_needs();
1000         if (want_obj.nr) {
1001                 get_common_commits();
1002                 create_pack_file();
1003         }
1004 }
1005
1006 static int upload_pack_config(const char *var, const char *value, void *unused)
1007 {
1008         if (!strcmp("uploadpack.allowtipsha1inwant", var)) {
1009                 if (git_config_bool(var, value))
1010                         allow_unadvertised_object_request |= ALLOW_TIP_SHA1;
1011                 else
1012                         allow_unadvertised_object_request &= ~ALLOW_TIP_SHA1;
1013         } else if (!strcmp("uploadpack.allowreachablesha1inwant", var)) {
1014                 if (git_config_bool(var, value))
1015                         allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
1016                 else
1017                         allow_unadvertised_object_request &= ~ALLOW_REACHABLE_SHA1;
1018         } else if (!strcmp("uploadpack.allowanysha1inwant", var)) {
1019                 if (git_config_bool(var, value))
1020                         allow_unadvertised_object_request |= ALLOW_ANY_SHA1;
1021                 else
1022                         allow_unadvertised_object_request &= ~ALLOW_ANY_SHA1;
1023         } else if (!strcmp("uploadpack.keepalive", var)) {
1024                 keepalive = git_config_int(var, value);
1025                 if (!keepalive)
1026                         keepalive = -1;
1027         } else if (current_config_scope() != CONFIG_SCOPE_REPO) {
1028                 if (!strcmp("uploadpack.packobjectshook", var))
1029                         return git_config_string(&pack_objects_hook, var, value);
1030         }
1031         return parse_hide_refs_config(var, value, "uploadpack");
1032 }
1033
1034 int cmd_main(int argc, const char **argv)
1035 {
1036         const char *dir;
1037         int strict = 0;
1038         struct option options[] = {
1039                 OPT_BOOL(0, "stateless-rpc", &stateless_rpc,
1040                          N_("quit after a single request/response exchange")),
1041                 OPT_BOOL(0, "advertise-refs", &advertise_refs,
1042                          N_("exit immediately after initial ref advertisement")),
1043                 OPT_BOOL(0, "strict", &strict,
1044                          N_("do not try <directory>/.git/ if <directory> is no Git directory")),
1045                 OPT_INTEGER(0, "timeout", &timeout,
1046                             N_("interrupt transfer after <n> seconds of inactivity")),
1047                 OPT_END()
1048         };
1049
1050         packet_trace_identity("upload-pack");
1051         check_replace_refs = 0;
1052
1053         argc = parse_options(argc, argv, NULL, options, upload_pack_usage, 0);
1054
1055         if (argc != 1)
1056                 usage_with_options(upload_pack_usage, options);
1057
1058         if (timeout)
1059                 daemon_mode = 1;
1060
1061         setup_path();
1062
1063         dir = argv[0];
1064
1065         if (!enter_repo(dir, strict))
1066                 die("'%s' does not appear to be a git repository", dir);
1067
1068         git_config(upload_pack_config, NULL);
1069         upload_pack();
1070         return 0;
1071 }