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
  13 static const char upload_pack_usage[] = "git-upload-pack [--strict] [--timeout=nn] <dir>";
  14
  15 /* bits #0..7 in revision.h, #8..10 in commit.c */
  16 #define THEY_HAVE       (1u << 11)
  17 #define OUR_REF         (1u << 12)
  18 #define WANTED          (1u << 13)
  19 #define COMMON_KNOWN    (1u << 14)
  20 #define REACHABLE       (1u << 15)
  21
  22 #define SHALLOW         (1u << 16)
  23 #define NOT_SHALLOW     (1u << 17)
  24 #define CLIENT_SHALLOW  (1u << 18)
  25
  26 static unsigned long oldest_have;
  27
  28 static int multi_ack, nr_our_refs;
  29 static int use_thin_pack, use_ofs_delta;
  30 static struct object_array have_obj;
  31 static struct object_array want_obj;
  32 static unsigned int timeout;
  33 /* 0 for no sideband,
  34  * otherwise maximum packet size (up to 65520 bytes).
  35  */
  36 static int use_sideband;
  37
  38 static void reset_timeout(void)
  39 {
  40         alarm(timeout);
  41 }
  42
  43 static int strip(char *line, int len)
  44 {
  45         if (len && line[len-1] == '\n')
  46                 line[--len] = 0;
  47         return len;
  48 }
  49
  50 static ssize_t send_client_data(int fd, const char *data, ssize_t sz)
  51 {
  52         if (use_sideband)
  53                 return send_sideband(1, fd, data, sz, use_sideband);
  54         if (fd == 3)
  55                 /* emergency quit */
  56                 fd = 2;
  57         if (fd == 2) {
  58                 /* XXX: are we happy to lose stuff here? */
  59                 xwrite(fd, data, sz);
  60                 return sz;
  61         }
  62         return safe_write(fd, data, sz);
  63 }
  64
  65 FILE *pack_pipe = NULL;
  66 static void show_commit(struct commit *commit)
  67 {
  68         if (commit->object.flags & BOUNDARY)
  69                 fputc('-', pack_pipe);
  70         if (fputs(sha1_to_hex(commit->object.sha1), pack_pipe) < 0)
  71                 die("broken output pipe");
  72         fputc('\n', pack_pipe);
  73         fflush(pack_pipe);
  74         free(commit->buffer);
  75         commit->buffer = NULL;
  76 }
  77
  78 static void show_object(struct object_array_entry *p)
  79 {
  80         /* An object with name "foo\n0000000..." can be used to
  81          * confuse downstream git-pack-objects very badly.
  82          */
  83         const char *ep = strchr(p->name, '\n');
  84         if (ep) {
  85                 fprintf(pack_pipe, "%s %.*s\n", sha1_to_hex(p->item->sha1),
  86                        (int) (ep - p->name),
  87                        p->name);
  88         }
  89         else
  90                 fprintf(pack_pipe, "%s %s\n",
  91                                 sha1_to_hex(p->item->sha1), p->name);
  92 }
  93
  94 static void show_edge(struct commit *commit)
  95 {
  96         fprintf(pack_pipe, "-%s\n", sha1_to_hex(commit->object.sha1));
  97 }
  98
  99 static void create_pack_file(void)
 100 {
 101         /* Pipes between rev-list to pack-objects, pack-objects to us
 102          * and pack-objects error stream for progress bar.
 103          */
 104         int lp_pipe[2], pu_pipe[2], pe_pipe[2];
 105         pid_t pid_rev_list, pid_pack_objects;
 106         int create_full_pack = (nr_our_refs == want_obj.nr && !have_obj.nr);
 107         char data[8193], progress[128];
 108         char abort_msg[] = "aborting due to possible repository "
 109                 "corruption on the remote side.";
 110         int buffered = -1;
 111
 112         if (pipe(lp_pipe) < 0)
 113                 die("git-upload-pack: unable to create pipe");
 114         pid_rev_list = fork();
 115         if (pid_rev_list < 0)
 116                 die("git-upload-pack: unable to fork git-rev-list");
 117
 118         if (!pid_rev_list) {
 119                 int i;
 120                 struct rev_info revs;
 121
 122                 pack_pipe = fdopen(lp_pipe[1], "w");
 123
 124                 if (create_full_pack)
 125                         use_thin_pack = 0; /* no point doing it */
 126                 init_revisions(&revs, NULL);
 127                 revs.tag_objects = 1;
 128                 revs.tree_objects = 1;
 129                 revs.blob_objects = 1;
 130                 if (use_thin_pack)
 131                         revs.edge_hint = 1;
 132
 133                 if (create_full_pack) {
 134                         const char *args[] = {"rev-list", "--all", NULL};
 135                         setup_revisions(2, args, &revs, NULL);
 136                 } else {
 137                         for (i = 0; i < want_obj.nr; i++) {
 138                                 struct object *o = want_obj.objects[i].item;
 139                                 /* why??? */
 140                                 o->flags &= ~UNINTERESTING;
 141                                 add_pending_object(&revs, o, NULL);
 142                         }
 143                         for (i = 0; i < have_obj.nr; i++) {
 144                                 struct object *o = have_obj.objects[i].item;
 145                                 o->flags |= UNINTERESTING;
 146                                 add_pending_object(&revs, o, NULL);
 147                         }
 148                         setup_revisions(0, NULL, &revs, NULL);
 149                 }
 150                 prepare_revision_walk(&revs);
 151                 mark_edges_uninteresting(revs.commits, &revs, show_edge);
 152                 traverse_commit_list(&revs, show_commit, show_object);
 153                 exit(0);
 154         }
 155
 156         if (pipe(pu_pipe) < 0)
 157                 die("git-upload-pack: unable to create pipe");
 158         if (pipe(pe_pipe) < 0)
 159                 die("git-upload-pack: unable to create pipe");
 160         pid_pack_objects = fork();
 161         if (pid_pack_objects < 0) {
 162                 /* daemon sets things up to ignore TERM */
 163                 kill(pid_rev_list, SIGKILL);
 164                 die("git-upload-pack: unable to fork git-pack-objects");
 165         }
 166         if (!pid_pack_objects) {
 167                 dup2(lp_pipe[0], 0);
 168                 dup2(pu_pipe[1], 1);
 169                 dup2(pe_pipe[1], 2);
 170
 171                 close(lp_pipe[0]);
 172                 close(lp_pipe[1]);
 173                 close(pu_pipe[0]);
 174                 close(pu_pipe[1]);
 175                 close(pe_pipe[0]);
 176                 close(pe_pipe[1]);
 177                 execl_git_cmd("pack-objects", "--stdout", "--progress",
 178                               use_ofs_delta ? "--delta-base-offset" : NULL,
 179                               NULL);
 180                 kill(pid_rev_list, SIGKILL);
 181                 die("git-upload-pack: unable to exec git-pack-objects");
 182         }
 183
 184         close(lp_pipe[0]);
 185         close(lp_pipe[1]);
 186
 187         /* We read from pe_pipe[0] to capture stderr output for
 188          * progress bar, and pu_pipe[0] to capture the pack data.
 189          */
 190         close(pe_pipe[1]);
 191         close(pu_pipe[1]);
 192
 193         while (1) {
 194                 const char *who;
 195                 struct pollfd pfd[2];
 196                 pid_t pid;
 197                 int status;
 198                 ssize_t sz;
 199                 int pe, pu, pollsize;
 200
 201                 reset_timeout();
 202
 203                 pollsize = 0;
 204                 pe = pu = -1;
 205
 206                 if (0 <= pu_pipe[0]) {
 207                         pfd[pollsize].fd = pu_pipe[0];
 208                         pfd[pollsize].events = POLLIN;
 209                         pu = pollsize;
 210                         pollsize++;
 211                 }
 212                 if (0 <= pe_pipe[0]) {
 213                         pfd[pollsize].fd = pe_pipe[0];
 214                         pfd[pollsize].events = POLLIN;
 215                         pe = pollsize;
 216                         pollsize++;
 217                 }
 218
 219                 if (pollsize) {
 220                         if (poll(pfd, pollsize, -1) < 0) {
 221                                 if (errno != EINTR) {
 222                                         error("poll failed, resuming: %s",
 223                                               strerror(errno));
 224                                         sleep(1);
 225                                 }
 226                                 continue;
 227                         }
 228                         if (0 <= pu && (pfd[pu].revents & (POLLIN|POLLHUP))) {
 229                                 /* Data ready; we keep the last byte
 230                                  * to ourselves in case we detect
 231                                  * broken rev-list, so that we can
 232                                  * leave the stream corrupted.  This
 233                                  * is unfortunate -- unpack-objects
 234                                  * would happily accept a valid pack
 235                                  * data with trailing garbage, so
 236                                  * appending garbage after we pass all
 237                                  * the pack data is not good enough to
 238                                  * signal breakage to downstream.
 239                                  */
 240                                 char *cp = data;
 241                                 ssize_t outsz = 0;
 242                                 if (0 <= buffered) {
 243                                         *cp++ = buffered;
 244                                         outsz++;
 245                                 }
 246                                 sz = xread(pu_pipe[0], cp,
 247                                           sizeof(data) - outsz);
 248                                 if (0 < sz)
 249                                                 ;
 250                                 else if (sz == 0) {
 251                                         close(pu_pipe[0]);
 252                                         pu_pipe[0] = -1;
 253                                 }
 254                                 else
 255                                         goto fail;
 256                                 sz += outsz;
 257                                 if (1 < sz) {
 258                                         buffered = data[sz-1] & 0xFF;
 259                                         sz--;
 260                                 }
 261                                 else
 262                                         buffered = -1;
 263                                 sz = send_client_data(1, data, sz);
 264                                 if (sz < 0)
 265                                         goto fail;
 266                         }
 267                         if (0 <= pe && (pfd[pe].revents & (POLLIN|POLLHUP))) {
 268                                 /* Status ready; we ship that in the side-band
 269                                  * or dump to the standard error.
 270                                  */
 271                                 sz = xread(pe_pipe[0], progress,
 272                                           sizeof(progress));
 273                                 if (0 < sz)
 274                                         send_client_data(2, progress, sz);
 275                                 else if (sz == 0) {
 276                                         close(pe_pipe[0]);
 277                                         pe_pipe[0] = -1;
 278                                 }
 279                                 else
 280                                         goto fail;
 281                         }
 282                 }
 283
 284                 /* See if the children are still there */
 285                 if (pid_rev_list || pid_pack_objects) {
 286                         pid = waitpid(-1, &status, WNOHANG);
 287                         if (!pid)
 288                                 continue;
 289                         who = ((pid == pid_rev_list) ? "git-rev-list" :
 290                                (pid == pid_pack_objects) ? "git-pack-objects" :
 291                                NULL);
 292                         if (!who) {
 293                                 if (pid < 0) {
 294                                         error("git-upload-pack: %s",
 295                                               strerror(errno));
 296                                         goto fail;
 297                                 }
 298                                 error("git-upload-pack: we weren't "
 299                                       "waiting for %d", pid);
 300                                 continue;
 301                         }
 302                         if (!WIFEXITED(status) || WEXITSTATUS(status) > 0) {
 303                                 error("git-upload-pack: %s died with error.",
 304                                       who);
 305                                 goto fail;
 306                         }
 307                         if (pid == pid_rev_list)
 308                                 pid_rev_list = 0;
 309                         if (pid == pid_pack_objects)
 310                                 pid_pack_objects = 0;
 311                         if (pid_rev_list || pid_pack_objects)
 312                                 continue;
 313                 }
 314
 315                 /* both died happily */
 316                 if (pollsize)
 317                         continue;
 318
 319                 /* flush the data */
 320                 if (0 <= buffered) {
 321                         data[0] = buffered;
 322                         sz = send_client_data(1, data, 1);
 323                         if (sz < 0)
 324                                 goto fail;
 325                         fprintf(stderr, "flushed.\n");
 326                 }
 327                 if (use_sideband)
 328                         packet_flush(1);
 329                 return;
 330         }
 331  fail:
 332         if (pid_pack_objects)
 333                 kill(pid_pack_objects, SIGKILL);
 334         if (pid_rev_list)
 335                 kill(pid_rev_list, SIGKILL);
 336         send_client_data(3, abort_msg, sizeof(abort_msg));
 337         die("git-upload-pack: %s", abort_msg);
 338 }
 339
 340 static int got_sha1(char *hex, unsigned char *sha1)
 341 {
 342         struct object *o;
 343         int we_knew_they_have = 0;
 344
 345         if (get_sha1_hex(hex, sha1))
 346                 die("git-upload-pack: expected SHA1 object, got '%s'", hex);
 347         if (!has_sha1_file(sha1))
 348                 return -1;
 349
 350         o = lookup_object(sha1);
 351         if (!(o && o->parsed))
 352                 o = parse_object(sha1);
 353         if (!o)
 354                 die("oops (%s)", sha1_to_hex(sha1));
 355         if (o->type == OBJ_COMMIT) {
 356                 struct commit_list *parents;
 357                 struct commit *commit = (struct commit *)o;
 358                 if (o->flags & THEY_HAVE)
 359                         we_knew_they_have = 1;
 360                 else
 361                         o->flags |= THEY_HAVE;
 362                 if (!oldest_have || (commit->date < oldest_have))
 363                         oldest_have = commit->date;
 364                 for (parents = commit->parents;
 365                      parents;
 366                      parents = parents->next)
 367                         parents->item->object.flags |= THEY_HAVE;
 368         }
 369         if (!we_knew_they_have) {
 370                 add_object_array(o, NULL, &have_obj);
 371                 return 1;
 372         }
 373         return 0;
 374 }
 375
 376 static int reachable(struct commit *want)
 377 {
 378         struct commit_list *work = NULL;
 379
 380         insert_by_date(want, &work);
 381         while (work) {
 382                 struct commit_list *list = work->next;
 383                 struct commit *commit = work->item;
 384                 free(work);
 385                 work = list;
 386
 387                 if (commit->object.flags & THEY_HAVE) {
 388                         want->object.flags |= COMMON_KNOWN;
 389                         break;
 390                 }
 391                 if (!commit->object.parsed)
 392                         parse_object(commit->object.sha1);
 393                 if (commit->object.flags & REACHABLE)
 394                         continue;
 395                 commit->object.flags |= REACHABLE;
 396                 if (commit->date < oldest_have)
 397                         continue;
 398                 for (list = commit->parents; list; list = list->next) {
 399                         struct commit *parent = list->item;
 400                         if (!(parent->object.flags & REACHABLE))
 401                                 insert_by_date(parent, &work);
 402                 }
 403         }
 404         want->object.flags |= REACHABLE;
 405         clear_commit_marks(want, REACHABLE);
 406         free_commit_list(work);
 407         return (want->object.flags & COMMON_KNOWN);
 408 }
 409
 410 static int ok_to_give_up(void)
 411 {
 412         int i;
 413
 414         if (!have_obj.nr)
 415                 return 0;
 416
 417         for (i = 0; i < want_obj.nr; i++) {
 418                 struct object *want = want_obj.objects[i].item;
 419
 420                 if (want->flags & COMMON_KNOWN)
 421                         continue;
 422                 want = deref_tag(want, "a want line", 0);
 423                 if (!want || want->type != OBJ_COMMIT) {
 424                         /* no way to tell if this is reachable by
 425                          * looking at the ancestry chain alone, so
 426                          * leave a note to ourselves not to worry about
 427                          * this object anymore.
 428                          */
 429                         want_obj.objects[i].item->flags |= COMMON_KNOWN;
 430                         continue;
 431                 }
 432                 if (!reachable((struct commit *)want))
 433                         return 0;
 434         }
 435         return 1;
 436 }
 437
 438 static int get_common_commits(void)
 439 {
 440         static char line[1000];
 441         unsigned char sha1[20];
 442         char hex[41], last_hex[41];
 443         int len;
 444
 445         track_object_refs = 0;
 446         save_commit_buffer = 0;
 447
 448         for(;;) {
 449                 len = packet_read_line(0, line, sizeof(line));
 450                 reset_timeout();
 451
 452                 if (!len) {
 453                         if (have_obj.nr == 0 || multi_ack)
 454                                 packet_write(1, "NAK\n");
 455                         continue;
 456                 }
 457                 len = strip(line, len);
 458                 if (!prefixcmp(line, "have ")) {
 459                         switch (got_sha1(line+5, sha1)) {
 460                         case -1: /* they have what we do not */
 461                                 if (multi_ack && ok_to_give_up())
 462                                         packet_write(1, "ACK %s continue\n",
 463                                                      sha1_to_hex(sha1));
 464                                 break;
 465                         default:
 466                                 memcpy(hex, sha1_to_hex(sha1), 41);
 467                                 if (multi_ack) {
 468                                         const char *msg = "ACK %s continue\n";
 469                                         packet_write(1, msg, hex);
 470                                         memcpy(last_hex, hex, 41);
 471                                 }
 472                                 else if (have_obj.nr == 1)
 473                                         packet_write(1, "ACK %s\n", hex);
 474                                 break;
 475                         }
 476                         continue;
 477                 }
 478                 if (!strcmp(line, "done")) {
 479                         if (have_obj.nr > 0) {
 480                                 if (multi_ack)
 481                                         packet_write(1, "ACK %s\n", last_hex);
 482                                 return 0;
 483                         }
 484                         packet_write(1, "NAK\n");
 485                         return -1;
 486                 }
 487                 die("git-upload-pack: expected SHA1 list, got '%s'", line);
 488         }
 489 }
 490
 491 static void receive_needs(void)
 492 {
 493         struct object_array shallows = {0, 0, NULL};
 494         static char line[1000];
 495         int len, depth = 0;
 496
 497         for (;;) {
 498                 struct object *o;
 499                 unsigned char sha1_buf[20];
 500                 len = packet_read_line(0, line, sizeof(line));
 501                 reset_timeout();
 502                 if (!len)
 503                         break;
 504
 505                 if (!prefixcmp(line, "shallow ")) {
 506                         unsigned char sha1[20];
 507                         struct object *object;
 508                         use_thin_pack = 0;
 509                         if (get_sha1(line + 8, sha1))
 510                                 die("invalid shallow line: %s", line);
 511                         object = parse_object(sha1);
 512                         if (!object)
 513                                 die("did not find object for %s", line);
 514                         object->flags |= CLIENT_SHALLOW;
 515                         add_object_array(object, NULL, &shallows);
 516                         continue;
 517                 }
 518                 if (!prefixcmp(line, "deepen ")) {
 519                         char *end;
 520                         use_thin_pack = 0;
 521                         depth = strtol(line + 7, &end, 0);
 522                         if (end == line + 7 || depth <= 0)
 523                                 die("Invalid deepen: %s", line);
 524                         continue;
 525                 }
 526                 if (prefixcmp(line, "want ") ||
 527                     get_sha1_hex(line+5, sha1_buf))
 528                         die("git-upload-pack: protocol error, "
 529                             "expected to get sha, not '%s'", line);
 530                 if (strstr(line+45, "multi_ack"))
 531                         multi_ack = 1;
 532                 if (strstr(line+45, "thin-pack"))
 533                         use_thin_pack = 1;
 534                 if (strstr(line+45, "ofs-delta"))
 535                         use_ofs_delta = 1;
 536                 if (strstr(line+45, "side-band-64k"))
 537                         use_sideband = LARGE_PACKET_MAX;
 538                 else if (strstr(line+45, "side-band"))
 539                         use_sideband = DEFAULT_PACKET_MAX;
 540
 541                 /* We have sent all our refs already, and the other end
 542                  * should have chosen out of them; otherwise they are
 543                  * asking for nonsense.
 544                  *
 545                  * Hmph.  We may later want to allow "want" line that
 546                  * asks for something like "master~10" (symbolic)...
 547                  * would it make sense?  I don't know.
 548                  */
 549                 o = lookup_object(sha1_buf);
 550                 if (!o || !(o->flags & OUR_REF))
 551                         die("git-upload-pack: not our ref %s", line+5);
 552                 if (!(o->flags & WANTED)) {
 553                         o->flags |= WANTED;
 554                         add_object_array(o, NULL, &want_obj);
 555                 }
 556         }
 557         if (depth == 0 && shallows.nr == 0)
 558                 return;
 559         if (depth > 0) {
 560                 struct commit_list *result, *backup;
 561                 int i;
 562                 backup = result = get_shallow_commits(&want_obj, depth,
 563                         SHALLOW, NOT_SHALLOW);
 564                 while (result) {
 565                         struct object *object = &result->item->object;
 566                         if (!(object->flags & (CLIENT_SHALLOW|NOT_SHALLOW))) {
 567                                 packet_write(1, "shallow %s",
 568                                                 sha1_to_hex(object->sha1));
 569                                 register_shallow(object->sha1);
 570                         }
 571                         result = result->next;
 572                 }
 573                 free_commit_list(backup);
 574                 for (i = 0; i < shallows.nr; i++) {
 575                         struct object *object = shallows.objects[i].item;
 576                         if (object->flags & NOT_SHALLOW) {
 577                                 struct commit_list *parents;
 578                                 packet_write(1, "unshallow %s",
 579                                         sha1_to_hex(object->sha1));
 580                                 object->flags &= ~CLIENT_SHALLOW;
 581                                 /* make sure the real parents are parsed */
 582                                 unregister_shallow(object->sha1);
 583                                 object->parsed = 0;
 584                                 parse_commit((struct commit *)object);
 585                                 parents = ((struct commit *)object)->parents;
 586                                 while (parents) {
 587                                         add_object_array(&parents->item->object,
 588                                                         NULL, &want_obj);
 589                                         parents = parents->next;
 590                                 }
 591                         }
 592                         /* make sure commit traversal conforms to client */
 593                         register_shallow(object->sha1);
 594                 }
 595                 packet_flush(1);
 596         } else
 597                 if (shallows.nr > 0) {
 598                         int i;
 599                         for (i = 0; i < shallows.nr; i++)
 600                                 register_shallow(shallows.objects[i].item->sha1);
 601                 }
 602         free(shallows.objects);
 603 }
 604
 605 static int send_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 606 {
 607         static const char *capabilities = "multi_ack thin-pack side-band"
 608                 " side-band-64k ofs-delta shallow";
 609         struct object *o = parse_object(sha1);
 610
 611         if (!o)
 612                 die("git-upload-pack: cannot find object %s:", sha1_to_hex(sha1));
 613
 614         if (capabilities)
 615                 packet_write(1, "%s %s%c%s\n", sha1_to_hex(sha1), refname,
 616                         0, capabilities);
 617         else
 618                 packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
 619         capabilities = NULL;
 620         if (!(o->flags & OUR_REF)) {
 621                 o->flags |= OUR_REF;
 622                 nr_our_refs++;
 623         }
 624         if (o->type == OBJ_TAG) {
 625                 o = deref_tag(o, refname, 0);
 626                 packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
 627         }
 628         return 0;
 629 }
 630
 631 static void upload_pack(void)
 632 {
 633         reset_timeout();
 634         head_ref(send_ref, NULL);
 635         for_each_ref(send_ref, NULL);
 636         packet_flush(1);
 637         receive_needs();
 638         if (want_obj.nr) {
 639                 get_common_commits();
 640                 create_pack_file();
 641         }
 642 }
 643
 644 int main(int argc, char **argv)
 645 {
 646         char *dir;
 647         int i;
 648         int strict = 0;
 649
 650         for (i = 1; i < argc; i++) {
 651                 char *arg = argv[i];
 652
 653                 if (arg[0] != '-')
 654                         break;
 655                 if (!strcmp(arg, "--strict")) {
 656                         strict = 1;
 657                         continue;
 658                 }
 659                 if (!prefixcmp(arg, "--timeout=")) {
 660                         timeout = atoi(arg+10);
 661                         continue;
 662                 }
 663                 if (!strcmp(arg, "--")) {
 664                         i++;
 665                         break;
 666                 }
 667         }
 668
 669         if (i != argc-1)
 670                 usage(upload_pack_usage);
 671         dir = argv[i];
 672
 673         if (!enter_repo(dir, strict))
 674                 die("'%s': unable to chdir or not a git archive", dir);
 675         if (is_repository_shallow())
 676                 die("attempt to fetch/clone from a shallow repository");
 677         upload_pack();
 678         return 0;
 679 }