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