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