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
  14 static const char upload_pack_usage[] = "git upload-pack [--strict] [--timeout=nn] <dir>";
  15
  16 /* bits #0..7 in revision.h, #8..10 in commit.c */
  17 #define THEY_HAVE       (1u << 11)
  18 #define OUR_REF         (1u << 12)
  19 #define WANTED          (1u << 13)
  20 #define COMMON_KNOWN    (1u << 14)
  21 #define REACHABLE       (1u << 15)
  22
  23 #define SHALLOW         (1u << 16)
  24 #define NOT_SHALLOW     (1u << 17)
  25 #define CLIENT_SHALLOW  (1u << 18)
  26
  27 static unsigned long oldest_have;
  28
  29 static int multi_ack, nr_our_refs;
  30 static int use_thin_pack, use_ofs_delta, use_include_tag;
  31 static int no_progress, daemon_mode;
  32 static int shallow_nr;
  33 static struct object_array have_obj;
  34 static struct object_array want_obj;
  35 static unsigned int timeout;
  36 /* 0 for no sideband,
  37  * otherwise maximum packet size (up to 65520 bytes).
  38  */
  39 static int use_sideband;
  40 static int debug_fd;
  41
  42 static void reset_timeout(void)
  43 {
  44         alarm(timeout);
  45 }
  46
  47 static int strip(char *line, int len)
  48 {
  49         if (len && line[len-1] == '\n')
  50                 line[--len] = 0;
  51         return len;
  52 }
  53
  54 static ssize_t send_client_data(int fd, const char *data, ssize_t sz)
  55 {
  56         if (use_sideband)
  57                 return send_sideband(1, fd, data, sz, use_sideband);
  58         if (fd == 3)
  59                 /* emergency quit */
  60                 fd = 2;
  61         if (fd == 2) {
  62                 /* XXX: are we happy to lose stuff here? */
  63                 xwrite(fd, data, sz);
  64                 return sz;
  65         }
  66         return safe_write(fd, data, sz);
  67 }
  68
  69 static FILE *pack_pipe = NULL;
  70 static void show_commit(struct commit *commit, void *data)
  71 {
  72         if (commit->object.flags & BOUNDARY)
  73                 fputc('-', pack_pipe);
  74         if (fputs(sha1_to_hex(commit->object.sha1), pack_pipe) < 0)
  75                 die("broken output pipe");
  76         fputc('\n', pack_pipe);
  77         fflush(pack_pipe);
  78         free(commit->buffer);
  79         commit->buffer = NULL;
  80 }
  81
  82 static void show_object(struct object *obj, const struct name_path *path, const char *component)
  83 {
  84         /* An object with name "foo\n0000000..." can be used to
  85          * confuse downstream git-pack-objects very badly.
  86          */
  87         const char *name = path_name(path, component);
  88         const char *ep = strchr(name, '\n');
  89         if (ep) {
  90                 fprintf(pack_pipe, "%s %.*s\n", sha1_to_hex(obj->sha1),
  91                        (int) (ep - name),
  92                        name);
  93         }
  94         else
  95                 fprintf(pack_pipe, "%s %s\n",
  96                                 sha1_to_hex(obj->sha1), name);
  97         free((char *)name);
  98 }
  99
 100 static void show_edge(struct commit *commit)
 101 {
 102         fprintf(pack_pipe, "-%s\n", sha1_to_hex(commit->object.sha1));
 103 }
 104
 105 static int do_rev_list(int fd, void *create_full_pack)
 106 {
 107         int i;
 108         struct rev_info revs;
 109
 110         pack_pipe = fdopen(fd, "w");
 111         init_revisions(&revs, NULL);
 112         revs.tag_objects = 1;
 113         revs.tree_objects = 1;
 114         revs.blob_objects = 1;
 115         if (use_thin_pack)
 116                 revs.edge_hint = 1;
 117
 118         if (create_full_pack) {
 119                 const char *args[] = {"rev-list", "--all", NULL};
 120                 setup_revisions(2, args, &revs, NULL);
 121         } else {
 122                 for (i = 0; i < want_obj.nr; i++) {
 123                         struct object *o = want_obj.objects[i].item;
 124                         /* why??? */
 125                         o->flags &= ~UNINTERESTING;
 126                         add_pending_object(&revs, o, NULL);
 127                 }
 128                 for (i = 0; i < have_obj.nr; i++) {
 129                         struct object *o = have_obj.objects[i].item;
 130                         o->flags |= UNINTERESTING;
 131                         add_pending_object(&revs, o, NULL);
 132                 }
 133                 setup_revisions(0, NULL, &revs, NULL);
 134         }
 135         if (prepare_revision_walk(&revs))
 136                 die("revision walk setup failed");
 137         mark_edges_uninteresting(revs.commits, &revs, show_edge);
 138         traverse_commit_list(&revs, show_commit, show_object, NULL);
 139         fflush(pack_pipe);
 140         fclose(pack_pipe);
 141         return 0;
 142 }
 143
 144 static void create_pack_file(void)
 145 {
 146         struct async rev_list;
 147         struct child_process pack_objects;
 148         int create_full_pack = (nr_our_refs == want_obj.nr && !have_obj.nr);
 149         char data[8193], progress[128];
 150         char abort_msg[] = "aborting due to possible repository "
 151                 "corruption on the remote side.";
 152         int buffered = -1;
 153         ssize_t sz;
 154         const char *argv[10];
 155         int arg = 0;
 156
 157         if (shallow_nr) {
 158                 rev_list.proc = do_rev_list;
 159                 rev_list.data = 0;
 160                 if (start_async(&rev_list))
 161                         die("git upload-pack: unable to fork git-rev-list");
 162                 argv[arg++] = "pack-objects";
 163         } else {
 164                 argv[arg++] = "pack-objects";
 165                 argv[arg++] = "--revs";
 166                 if (create_full_pack)
 167                         argv[arg++] = "--all";
 168                 else if (use_thin_pack)
 169                         argv[arg++] = "--thin";
 170         }
 171
 172         argv[arg++] = "--stdout";
 173         if (!no_progress)
 174                 argv[arg++] = "--progress";
 175         if (use_ofs_delta)
 176                 argv[arg++] = "--delta-base-offset";
 177         if (use_include_tag)
 178                 argv[arg++] = "--include-tag";
 179         argv[arg++] = NULL;
 180
 181         memset(&pack_objects, 0, sizeof(pack_objects));
 182         pack_objects.in = shallow_nr ? rev_list.out : -1;
 183         pack_objects.out = -1;
 184         pack_objects.err = -1;
 185         pack_objects.git_cmd = 1;
 186         pack_objects.argv = argv;
 187
 188         if (start_command(&pack_objects))
 189                 die("git upload-pack: unable to fork git-pack-objects");
 190
 191         /* pass on revisions we (don't) want */
 192         if (!shallow_nr) {
 193                 FILE *pipe_fd = fdopen(pack_objects.in, "w");
 194                 if (!create_full_pack) {
 195                         int i;
 196                         for (i = 0; i < want_obj.nr; i++)
 197                                 fprintf(pipe_fd, "%s\n", sha1_to_hex(want_obj.objects[i].item->sha1));
 198                         fprintf(pipe_fd, "--not\n");
 199                         for (i = 0; i < have_obj.nr; i++)
 200                                 fprintf(pipe_fd, "%s\n", sha1_to_hex(have_obj.objects[i].item->sha1));
 201                 }
 202
 203                 fprintf(pipe_fd, "\n");
 204                 fflush(pipe_fd);
 205                 fclose(pipe_fd);
 206         }
 207
 208
 209         /* We read from pack_objects.err to capture stderr output for
 210          * progress bar, and pack_objects.out to capture the pack data.
 211          */
 212
 213         while (1) {
 214                 struct pollfd pfd[2];
 215                 int pe, pu, pollsize;
 216
 217                 reset_timeout();
 218
 219                 pollsize = 0;
 220                 pe = pu = -1;
 221
 222                 if (0 <= pack_objects.out) {
 223                         pfd[pollsize].fd = pack_objects.out;
 224                         pfd[pollsize].events = POLLIN;
 225                         pu = pollsize;
 226                         pollsize++;
 227                 }
 228                 if (0 <= pack_objects.err) {
 229                         pfd[pollsize].fd = pack_objects.err;
 230                         pfd[pollsize].events = POLLIN;
 231                         pe = pollsize;
 232                         pollsize++;
 233                 }
 234
 235                 if (!pollsize)
 236                         break;
 237
 238                 if (poll(pfd, pollsize, -1) < 0) {
 239                         if (errno != EINTR) {
 240                                 error("poll failed, resuming: %s",
 241                                       strerror(errno));
 242                                 sleep(1);
 243                         }
 244                         continue;
 245                 }
 246                 if (0 <= pu && (pfd[pu].revents & (POLLIN|POLLHUP))) {
 247                         /* Data ready; we keep the last byte to ourselves
 248                          * in case we detect broken rev-list, so that we
 249                          * can leave the stream corrupted.  This is
 250                          * unfortunate -- unpack-objects would happily
 251                          * accept a valid packdata with trailing garbage,
 252                          * so appending garbage after we pass all the
 253                          * pack data is not good enough to signal
 254                          * breakage to downstream.
 255                          */
 256                         char *cp = data;
 257                         ssize_t outsz = 0;
 258                         if (0 <= buffered) {
 259                                 *cp++ = buffered;
 260                                 outsz++;
 261                         }
 262                         sz = xread(pack_objects.out, cp,
 263                                   sizeof(data) - outsz);
 264                         if (0 < sz)
 265                                         ;
 266                         else if (sz == 0) {
 267                                 close(pack_objects.out);
 268                                 pack_objects.out = -1;
 269                         }
 270                         else
 271                                 goto fail;
 272                         sz += outsz;
 273                         if (1 < sz) {
 274                                 buffered = data[sz-1] & 0xFF;
 275                                 sz--;
 276                         }
 277                         else
 278                                 buffered = -1;
 279                         sz = send_client_data(1, data, sz);
 280                         if (sz < 0)
 281                                 goto fail;
 282                 }
 283                 if (0 <= pe && (pfd[pe].revents & (POLLIN|POLLHUP))) {
 284                         /* Status ready; we ship that in the side-band
 285                          * or dump to the standard error.
 286                          */
 287                         sz = xread(pack_objects.err, progress,
 288                                   sizeof(progress));
 289                         if (0 < sz)
 290                                 send_client_data(2, progress, sz);
 291                         else if (sz == 0) {
 292                                 close(pack_objects.err);
 293                                 pack_objects.err = -1;
 294                         }
 295                         else
 296                                 goto fail;
 297                 }
 298         }
 299
 300         if (finish_command(&pack_objects)) {
 301                 error("git upload-pack: git-pack-objects died with error.");
 302                 goto fail;
 303         }
 304         if (shallow_nr && finish_async(&rev_list))
 305                 goto fail;      /* error was already reported */
 306
 307         /* flush the data */
 308         if (0 <= buffered) {
 309                 data[0] = buffered;
 310                 sz = send_client_data(1, data, 1);
 311                 if (sz < 0)
 312                         goto fail;
 313                 fprintf(stderr, "flushed.\n");
 314         }
 315         if (use_sideband)
 316                 packet_flush(1);
 317         return;
 318
 319  fail:
 320         send_client_data(3, abort_msg, sizeof(abort_msg));
 321         die("git upload-pack: %s", abort_msg);
 322 }
 323
 324 static int got_sha1(char *hex, unsigned char *sha1)
 325 {
 326         struct object *o;
 327         int we_knew_they_have = 0;
 328
 329         if (get_sha1_hex(hex, sha1))
 330                 die("git upload-pack: expected SHA1 object, got '%s'", hex);
 331         if (!has_sha1_file(sha1))
 332                 return -1;
 333
 334         o = lookup_object(sha1);
 335         if (!(o && o->parsed))
 336                 o = parse_object(sha1);
 337         if (!o)
 338                 die("oops (%s)", sha1_to_hex(sha1));
 339         if (o->type == OBJ_COMMIT) {
 340                 struct commit_list *parents;
 341                 struct commit *commit = (struct commit *)o;
 342                 if (o->flags & THEY_HAVE)
 343                         we_knew_they_have = 1;
 344                 else
 345                         o->flags |= THEY_HAVE;
 346                 if (!oldest_have || (commit->date < oldest_have))
 347                         oldest_have = commit->date;
 348                 for (parents = commit->parents;
 349                      parents;
 350                      parents = parents->next)
 351                         parents->item->object.flags |= THEY_HAVE;
 352         }
 353         if (!we_knew_they_have) {
 354                 add_object_array(o, NULL, &have_obj);
 355                 return 1;
 356         }
 357         return 0;
 358 }
 359
 360 static int reachable(struct commit *want)
 361 {
 362         struct commit_list *work = NULL;
 363
 364         insert_by_date(want, &work);
 365         while (work) {
 366                 struct commit_list *list = work->next;
 367                 struct commit *commit = work->item;
 368                 free(work);
 369                 work = list;
 370
 371                 if (commit->object.flags & THEY_HAVE) {
 372                         want->object.flags |= COMMON_KNOWN;
 373                         break;
 374                 }
 375                 if (!commit->object.parsed)
 376                         parse_object(commit->object.sha1);
 377                 if (commit->object.flags & REACHABLE)
 378                         continue;
 379                 commit->object.flags |= REACHABLE;
 380                 if (commit->date < oldest_have)
 381                         continue;
 382                 for (list = commit->parents; list; list = list->next) {
 383                         struct commit *parent = list->item;
 384                         if (!(parent->object.flags & REACHABLE))
 385                                 insert_by_date(parent, &work);
 386                 }
 387         }
 388         want->object.flags |= REACHABLE;
 389         clear_commit_marks(want, REACHABLE);
 390         free_commit_list(work);
 391         return (want->object.flags & COMMON_KNOWN);
 392 }
 393
 394 static int ok_to_give_up(void)
 395 {
 396         int i;
 397
 398         if (!have_obj.nr)
 399                 return 0;
 400
 401         for (i = 0; i < want_obj.nr; i++) {
 402                 struct object *want = want_obj.objects[i].item;
 403
 404                 if (want->flags & COMMON_KNOWN)
 405                         continue;
 406                 want = deref_tag(want, "a want line", 0);
 407                 if (!want || want->type != OBJ_COMMIT) {
 408                         /* no way to tell if this is reachable by
 409                          * looking at the ancestry chain alone, so
 410                          * leave a note to ourselves not to worry about
 411                          * this object anymore.
 412                          */
 413                         want_obj.objects[i].item->flags |= COMMON_KNOWN;
 414                         continue;
 415                 }
 416                 if (!reachable((struct commit *)want))
 417                         return 0;
 418         }
 419         return 1;
 420 }
 421
 422 static int get_common_commits(void)
 423 {
 424         static char line[1000];
 425         unsigned char sha1[20];
 426         char hex[41], last_hex[41];
 427
 428         save_commit_buffer = 0;
 429
 430         for(;;) {
 431                 int len = packet_read_line(0, line, sizeof(line));
 432                 reset_timeout();
 433
 434                 if (!len) {
 435                         if (have_obj.nr == 0 || multi_ack)
 436                                 packet_write(1, "NAK\n");
 437                         continue;
 438                 }
 439                 strip(line, len);
 440                 if (!prefixcmp(line, "have ")) {
 441                         switch (got_sha1(line+5, sha1)) {
 442                         case -1: /* they have what we do not */
 443                                 if (multi_ack && ok_to_give_up())
 444                                         packet_write(1, "ACK %s continue\n",
 445                                                      sha1_to_hex(sha1));
 446                                 break;
 447                         default:
 448                                 memcpy(hex, sha1_to_hex(sha1), 41);
 449                                 if (multi_ack) {
 450                                         const char *msg = "ACK %s continue\n";
 451                                         packet_write(1, msg, hex);
 452                                         memcpy(last_hex, hex, 41);
 453                                 }
 454                                 else if (have_obj.nr == 1)
 455                                         packet_write(1, "ACK %s\n", hex);
 456                                 break;
 457                         }
 458                         continue;
 459                 }
 460                 if (!strcmp(line, "done")) {
 461                         if (have_obj.nr > 0) {
 462                                 if (multi_ack)
 463                                         packet_write(1, "ACK %s\n", last_hex);
 464                                 return 0;
 465                         }
 466                         packet_write(1, "NAK\n");
 467                         return -1;
 468                 }
 469                 die("git upload-pack: expected SHA1 list, got '%s'", line);
 470         }
 471 }
 472
 473 static void receive_needs(void)
 474 {
 475         struct object_array shallows = {0, 0, NULL};
 476         static char line[1000];
 477         int len, depth = 0;
 478
 479         shallow_nr = 0;
 480         if (debug_fd)
 481                 write_in_full(debug_fd, "#S\n", 3);
 482         for (;;) {
 483                 struct object *o;
 484                 unsigned char sha1_buf[20];
 485                 len = packet_read_line(0, line, sizeof(line));
 486                 reset_timeout();
 487                 if (!len)
 488                         break;
 489                 if (debug_fd)
 490                         write_in_full(debug_fd, line, len);
 491
 492                 if (!prefixcmp(line, "shallow ")) {
 493                         unsigned char sha1[20];
 494                         struct object *object;
 495                         use_thin_pack = 0;
 496                         if (get_sha1(line + 8, sha1))
 497                                 die("invalid shallow line: %s", line);
 498                         object = parse_object(sha1);
 499                         if (!object)
 500                                 die("did not find object for %s", line);
 501                         object->flags |= CLIENT_SHALLOW;
 502                         add_object_array(object, NULL, &shallows);
 503                         continue;
 504                 }
 505                 if (!prefixcmp(line, "deepen ")) {
 506                         char *end;
 507                         use_thin_pack = 0;
 508                         depth = strtol(line + 7, &end, 0);
 509                         if (end == line + 7 || depth <= 0)
 510                                 die("Invalid deepen: %s", line);
 511                         continue;
 512                 }
 513                 if (prefixcmp(line, "want ") ||
 514                     get_sha1_hex(line+5, sha1_buf))
 515                         die("git upload-pack: protocol error, "
 516                             "expected to get sha, not '%s'", line);
 517                 if (strstr(line+45, "multi_ack"))
 518                         multi_ack = 1;
 519                 if (strstr(line+45, "thin-pack"))
 520                         use_thin_pack = 1;
 521                 if (strstr(line+45, "ofs-delta"))
 522                         use_ofs_delta = 1;
 523                 if (strstr(line+45, "side-band-64k"))
 524                         use_sideband = LARGE_PACKET_MAX;
 525                 else if (strstr(line+45, "side-band"))
 526                         use_sideband = DEFAULT_PACKET_MAX;
 527                 if (strstr(line+45, "no-progress"))
 528                         no_progress = 1;
 529                 if (strstr(line+45, "include-tag"))
 530                         use_include_tag = 1;
 531
 532                 /* We have sent all our refs already, and the other end
 533                  * should have chosen out of them; otherwise they are
 534                  * asking for nonsense.
 535                  *
 536                  * Hmph.  We may later want to allow "want" line that
 537                  * asks for something like "master~10" (symbolic)...
 538                  * would it make sense?  I don't know.
 539                  */
 540                 o = lookup_object(sha1_buf);
 541                 if (!o || !(o->flags & OUR_REF))
 542                         die("git upload-pack: not our ref %s", line+5);
 543                 if (!(o->flags & WANTED)) {
 544                         o->flags |= WANTED;
 545                         add_object_array(o, NULL, &want_obj);
 546                 }
 547         }
 548         if (debug_fd)
 549                 write_in_full(debug_fd, "#E\n", 3);
 550
 551         if (!use_sideband && daemon_mode)
 552                 no_progress = 1;
 553
 554         if (depth == 0 && shallows.nr == 0)
 555                 return;
 556         if (depth > 0) {
 557                 struct commit_list *result, *backup;
 558                 int i;
 559                 backup = result = get_shallow_commits(&want_obj, depth,
 560                         SHALLOW, NOT_SHALLOW);
 561                 while (result) {
 562                         struct object *object = &result->item->object;
 563                         if (!(object->flags & (CLIENT_SHALLOW|NOT_SHALLOW))) {
 564                                 packet_write(1, "shallow %s",
 565                                                 sha1_to_hex(object->sha1));
 566                                 register_shallow(object->sha1);
 567                                 shallow_nr++;
 568                         }
 569                         result = result->next;
 570                 }
 571                 free_commit_list(backup);
 572                 for (i = 0; i < shallows.nr; i++) {
 573                         struct object *object = shallows.objects[i].item;
 574                         if (object->flags & NOT_SHALLOW) {
 575                                 struct commit_list *parents;
 576                                 packet_write(1, "unshallow %s",
 577                                         sha1_to_hex(object->sha1));
 578                                 object->flags &= ~CLIENT_SHALLOW;
 579                                 /* make sure the real parents are parsed */
 580                                 unregister_shallow(object->sha1);
 581                                 object->parsed = 0;
 582                                 if (parse_commit((struct commit *)object))
 583                                         die("invalid commit");
 584                                 parents = ((struct commit *)object)->parents;
 585                                 while (parents) {
 586                                         add_object_array(&parents->item->object,
 587                                                         NULL, &want_obj);
 588                                         parents = parents->next;
 589                                 }
 590                         }
 591                         /* make sure commit traversal conforms to client */
 592                         register_shallow(object->sha1);
 593                 }
 594                 packet_flush(1);
 595         } else
 596                 if (shallows.nr > 0) {
 597                         int i;
 598                         for (i = 0; i < shallows.nr; i++)
 599                                 register_shallow(shallows.objects[i].item->sha1);
 600                 }
 601
 602         shallow_nr += shallows.nr;
 603         free(shallows.objects);
 604 }
 605
 606 static int send_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 607 {
 608         static const char *capabilities = "multi_ack thin-pack side-band"
 609                 " side-band-64k ofs-delta shallow no-progress"
 610                 " include-tag";
 611         struct object *o = parse_object(sha1);
 612
 613         if (!o)
 614                 die("git upload-pack: cannot find object %s:", sha1_to_hex(sha1));
 615
 616         if (capabilities)
 617                 packet_write(1, "%s %s%c%s\n", sha1_to_hex(sha1), refname,
 618                         0, capabilities);
 619         else
 620                 packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
 621         capabilities = NULL;
 622         if (!(o->flags & OUR_REF)) {
 623                 o->flags |= OUR_REF;
 624                 nr_our_refs++;
 625         }
 626         if (o->type == OBJ_TAG) {
 627                 o = deref_tag(o, refname, 0);
 628                 if (o)
 629                         packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
 630         }
 631         return 0;
 632 }
 633
 634 static void upload_pack(void)
 635 {
 636         reset_timeout();
 637         head_ref(send_ref, NULL);
 638         for_each_ref(send_ref, NULL);
 639         packet_flush(1);
 640         receive_needs();
 641         if (want_obj.nr) {
 642                 get_common_commits();
 643                 create_pack_file();
 644         }
 645 }
 646
 647 int main(int argc, char **argv)
 648 {
 649         char *dir;
 650         int i;
 651         int strict = 0;
 652
 653         git_extract_argv0_path(argv[0]);
 654
 655         for (i = 1; i < argc; i++) {
 656                 char *arg = argv[i];
 657
 658                 if (arg[0] != '-')
 659                         break;
 660                 if (!strcmp(arg, "--strict")) {
 661                         strict = 1;
 662                         continue;
 663                 }
 664                 if (!prefixcmp(arg, "--timeout=")) {
 665                         timeout = atoi(arg+10);
 666                         daemon_mode = 1;
 667                         continue;
 668                 }
 669                 if (!strcmp(arg, "--")) {
 670                         i++;
 671                         break;
 672                 }
 673         }
 674
 675         if (i != argc-1)
 676                 usage(upload_pack_usage);
 677
 678         setup_path();
 679
 680         dir = argv[i];
 681
 682         if (!enter_repo(dir, strict))
 683                 die("'%s' does not appear to be a git repository", dir);
 684         if (is_repository_shallow())
 685                 die("attempt to fetch/clone from a shallow repository");
 686         if (getenv("GIT_DEBUG_SEND_PACK"))
 687                 debug_fd = atoi(getenv("GIT_DEBUG_SEND_PACK"));
 688         upload_pack();
 689         return 0;
 690 }