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 *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);
 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 <= pe && (pfd[pe].revents & (POLLIN|POLLHUP))) {
 222                         /* Status ready; we ship that in the side-band
 223                          * or dump to the standard error.
 224                          */
 225                         sz = xread(pack_objects.err, progress,
 226                                   sizeof(progress));
 227                         if (0 < sz)
 228                                 send_client_data(2, progress, sz);
 229                         else if (sz == 0) {
 230                                 close(pack_objects.err);
 231                                 pack_objects.err = -1;
 232                         }
 233                         else
 234                                 goto fail;
 235                         /* give priority to status messages */
 236                         continue;
 237                 }
 238                 if (0 <= pu && (pfd[pu].revents & (POLLIN|POLLHUP))) {
 239                         /* Data ready; we keep the last byte to ourselves
 240                          * in case we detect broken rev-list, so that we
 241                          * can leave the stream corrupted.  This is
 242                          * unfortunate -- unpack-objects would happily
 243                          * accept a valid packdata with trailing garbage,
 244                          * so appending garbage after we pass all the
 245                          * pack data is not good enough to signal
 246                          * breakage to downstream.
 247                          */
 248                         char *cp = data;
 249                         ssize_t outsz = 0;
 250                         if (0 <= buffered) {
 251                                 *cp++ = buffered;
 252                                 outsz++;
 253                         }
 254                         sz = xread(pack_objects.out, cp,
 255                                   sizeof(data) - outsz);
 256                         if (0 < sz)
 257                                         ;
 258                         else if (sz == 0) {
 259                                 close(pack_objects.out);
 260                                 pack_objects.out = -1;
 261                         }
 262                         else
 263                                 goto fail;
 264                         sz += outsz;
 265                         if (1 < sz) {
 266                                 buffered = data[sz-1] & 0xFF;
 267                                 sz--;
 268                         }
 269                         else
 270                                 buffered = -1;
 271                         sz = send_client_data(1, data, sz);
 272                         if (sz < 0)
 273                                 goto fail;
 274                 }
 275         }
 276
 277         if (finish_command(&pack_objects)) {
 278                 error("git upload-pack: git-pack-objects died with error.");
 279                 goto fail;
 280         }
 281         if (finish_async(&rev_list))
 282                 goto fail;      /* error was already reported */
 283
 284         /* flush the data */
 285         if (0 <= buffered) {
 286                 data[0] = buffered;
 287                 sz = send_client_data(1, data, 1);
 288                 if (sz < 0)
 289                         goto fail;
 290                 fprintf(stderr, "flushed.\n");
 291         }
 292         if (use_sideband)
 293                 packet_flush(1);
 294         return;
 295
 296  fail:
 297         send_client_data(3, abort_msg, sizeof(abort_msg));
 298         die("git upload-pack: %s", abort_msg);
 299 }
 300
 301 static int got_sha1(char *hex, unsigned char *sha1)
 302 {
 303         struct object *o;
 304         int we_knew_they_have = 0;
 305
 306         if (get_sha1_hex(hex, sha1))
 307                 die("git upload-pack: expected SHA1 object, got '%s'", hex);
 308         if (!has_sha1_file(sha1))
 309                 return -1;
 310
 311         o = lookup_object(sha1);
 312         if (!(o && o->parsed))
 313                 o = parse_object(sha1);
 314         if (!o)
 315                 die("oops (%s)", sha1_to_hex(sha1));
 316         if (o->type == OBJ_COMMIT) {
 317                 struct commit_list *parents;
 318                 struct commit *commit = (struct commit *)o;
 319                 if (o->flags & THEY_HAVE)
 320                         we_knew_they_have = 1;
 321                 else
 322                         o->flags |= THEY_HAVE;
 323                 if (!oldest_have || (commit->date < oldest_have))
 324                         oldest_have = commit->date;
 325                 for (parents = commit->parents;
 326                      parents;
 327                      parents = parents->next)
 328                         parents->item->object.flags |= THEY_HAVE;
 329         }
 330         if (!we_knew_they_have) {
 331                 add_object_array(o, NULL, &have_obj);
 332                 return 1;
 333         }
 334         return 0;
 335 }
 336
 337 static int reachable(struct commit *want)
 338 {
 339         struct commit_list *work = NULL;
 340
 341         insert_by_date(want, &work);
 342         while (work) {
 343                 struct commit_list *list = work->next;
 344                 struct commit *commit = work->item;
 345                 free(work);
 346                 work = list;
 347
 348                 if (commit->object.flags & THEY_HAVE) {
 349                         want->object.flags |= COMMON_KNOWN;
 350                         break;
 351                 }
 352                 if (!commit->object.parsed)
 353                         parse_object(commit->object.sha1);
 354                 if (commit->object.flags & REACHABLE)
 355                         continue;
 356                 commit->object.flags |= REACHABLE;
 357                 if (commit->date < oldest_have)
 358                         continue;
 359                 for (list = commit->parents; list; list = list->next) {
 360                         struct commit *parent = list->item;
 361                         if (!(parent->object.flags & REACHABLE))
 362                                 insert_by_date(parent, &work);
 363                 }
 364         }
 365         want->object.flags |= REACHABLE;
 366         clear_commit_marks(want, REACHABLE);
 367         free_commit_list(work);
 368         return (want->object.flags & COMMON_KNOWN);
 369 }
 370
 371 static int ok_to_give_up(void)
 372 {
 373         int i;
 374
 375         if (!have_obj.nr)
 376                 return 0;
 377
 378         for (i = 0; i < want_obj.nr; i++) {
 379                 struct object *want = want_obj.objects[i].item;
 380
 381                 if (want->flags & COMMON_KNOWN)
 382                         continue;
 383                 want = deref_tag(want, "a want line", 0);
 384                 if (!want || want->type != OBJ_COMMIT) {
 385                         /* no way to tell if this is reachable by
 386                          * looking at the ancestry chain alone, so
 387                          * leave a note to ourselves not to worry about
 388                          * this object anymore.
 389                          */
 390                         want_obj.objects[i].item->flags |= COMMON_KNOWN;
 391                         continue;
 392                 }
 393                 if (!reachable((struct commit *)want))
 394                         return 0;
 395         }
 396         return 1;
 397 }
 398
 399 static int get_common_commits(void)
 400 {
 401         static char line[1000];
 402         unsigned char sha1[20];
 403         char hex[41], last_hex[41];
 404         int len;
 405
 406         save_commit_buffer = 0;
 407
 408         for(;;) {
 409                 len = packet_read_line(0, line, sizeof(line));
 410                 reset_timeout();
 411
 412                 if (!len) {
 413                         if (have_obj.nr == 0 || multi_ack)
 414                                 packet_write(1, "NAK\n");
 415                         continue;
 416                 }
 417                 len = strip(line, len);
 418                 if (!prefixcmp(line, "have ")) {
 419                         switch (got_sha1(line+5, sha1)) {
 420                         case -1: /* they have what we do not */
 421                                 if (multi_ack && ok_to_give_up())
 422                                         packet_write(1, "ACK %s continue\n",
 423                                                      sha1_to_hex(sha1));
 424                                 break;
 425                         default:
 426                                 memcpy(hex, sha1_to_hex(sha1), 41);
 427                                 if (multi_ack) {
 428                                         const char *msg = "ACK %s continue\n";
 429                                         packet_write(1, msg, hex);
 430                                         memcpy(last_hex, hex, 41);
 431                                 }
 432                                 else if (have_obj.nr == 1)
 433                                         packet_write(1, "ACK %s\n", hex);
 434                                 break;
 435                         }
 436                         continue;
 437                 }
 438                 if (!strcmp(line, "done")) {
 439                         if (have_obj.nr > 0) {
 440                                 if (multi_ack)
 441                                         packet_write(1, "ACK %s\n", last_hex);
 442                                 return 0;
 443                         }
 444                         packet_write(1, "NAK\n");
 445                         return -1;
 446                 }
 447                 die("git upload-pack: expected SHA1 list, got '%s'", line);
 448         }
 449 }
 450
 451 static void receive_needs(void)
 452 {
 453         struct object_array shallows = {0, 0, NULL};
 454         static char line[1000];
 455         int len, depth = 0;
 456
 457         if (debug_fd)
 458                 write_in_full(debug_fd, "#S\n", 3);
 459         for (;;) {
 460                 struct object *o;
 461                 unsigned char sha1_buf[20];
 462                 len = packet_read_line(0, line, sizeof(line));
 463                 reset_timeout();
 464                 if (!len)
 465                         break;
 466                 if (debug_fd)
 467                         write_in_full(debug_fd, line, len);
 468
 469                 if (!prefixcmp(line, "shallow ")) {
 470                         unsigned char sha1[20];
 471                         struct object *object;
 472                         use_thin_pack = 0;
 473                         if (get_sha1(line + 8, sha1))
 474                                 die("invalid shallow line: %s", line);
 475                         object = parse_object(sha1);
 476                         if (!object)
 477                                 die("did not find object for %s", line);
 478                         object->flags |= CLIENT_SHALLOW;
 479                         add_object_array(object, NULL, &shallows);
 480                         continue;
 481                 }
 482                 if (!prefixcmp(line, "deepen ")) {
 483                         char *end;
 484                         use_thin_pack = 0;
 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                         }
 563                         /* make sure commit traversal conforms to client */
 564                         register_shallow(object->sha1);
 565                 }
 566                 packet_flush(1);
 567         } else
 568                 if (shallows.nr > 0) {
 569                         int i;
 570                         for (i = 0; i < shallows.nr; i++)
 571                                 register_shallow(shallows.objects[i].item->sha1);
 572                 }
 573         free(shallows.objects);
 574 }
 575
 576 static int send_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 577 {
 578         static const char *capabilities = "multi_ack thin-pack side-band"
 579                 " side-band-64k ofs-delta shallow no-progress"
 580                 " include-tag";
 581         struct object *o = parse_object(sha1);
 582
 583         if (!o)
 584                 die("git upload-pack: cannot find object %s:", sha1_to_hex(sha1));
 585
 586         if (capabilities)
 587                 packet_write(1, "%s %s%c%s\n", sha1_to_hex(sha1), refname,
 588                         0, capabilities);
 589         else
 590                 packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
 591         capabilities = NULL;
 592         if (!(o->flags & OUR_REF)) {
 593                 o->flags |= OUR_REF;
 594                 nr_our_refs++;
 595         }
 596         if (o->type == OBJ_TAG) {
 597                 o = deref_tag(o, refname, 0);
 598                 if (o)
 599                         packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
 600         }
 601         return 0;
 602 }
 603
 604 static void upload_pack(void)
 605 {
 606         reset_timeout();
 607         head_ref(send_ref, NULL);
 608         for_each_ref(send_ref, NULL);
 609         packet_flush(1);
 610         receive_needs();
 611         if (want_obj.nr) {
 612                 get_common_commits();
 613                 create_pack_file();
 614         }
 615 }
 616
 617 int main(int argc, char **argv)
 618 {
 619         char *dir;
 620         int i;
 621         int strict = 0;
 622
 623         git_extract_argv0_path(argv[0]);
 624
 625         for (i = 1; i < argc; i++) {
 626                 char *arg = argv[i];
 627
 628                 if (arg[0] != '-')
 629                         break;
 630                 if (!strcmp(arg, "--strict")) {
 631                         strict = 1;
 632                         continue;
 633                 }
 634                 if (!prefixcmp(arg, "--timeout=")) {
 635                         timeout = atoi(arg+10);
 636                         continue;
 637                 }
 638                 if (!strcmp(arg, "--")) {
 639                         i++;
 640                         break;
 641                 }
 642         }
 643
 644         if (i != argc-1)
 645                 usage(upload_pack_usage);
 646
 647         setup_path();
 648
 649         dir = argv[i];
 650
 651         if (!enter_repo(dir, strict))
 652                 die("'%s': unable to chdir or not a git archive", dir);
 653         if (is_repository_shallow())
 654                 die("attempt to fetch/clone from a shallow repository");
 655         if (getenv("GIT_DEBUG_SEND_PACK"))
 656                 debug_fd = atoi(getenv("GIT_DEBUG_SEND_PACK"));
 657         upload_pack();
 658         return 0;
 659 }