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