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 do_rev_list(int create_full_pack)
 100 {
 101         int i;
 102         struct rev_info revs;
 103
 104         if (create_full_pack)
 105                 use_thin_pack = 0; /* no point doing it */
 106         init_revisions(&revs, NULL);
 107         revs.tag_objects = 1;
 108         revs.tree_objects = 1;
 109         revs.blob_objects = 1;
 110         if (use_thin_pack)
 111                 revs.edge_hint = 1;
 112
 113         if (create_full_pack) {
 114                 const char *args[] = {"rev-list", "--all", NULL};
 115                 setup_revisions(2, args, &revs, NULL);
 116         } else {
 117                 for (i = 0; i < want_obj.nr; i++) {
 118                         struct object *o = want_obj.objects[i].item;
 119                         /* why??? */
 120                         o->flags &= ~UNINTERESTING;
 121                         add_pending_object(&revs, o, NULL);
 122                 }
 123                 for (i = 0; i < have_obj.nr; i++) {
 124                         struct object *o = have_obj.objects[i].item;
 125                         o->flags |= UNINTERESTING;
 126                         add_pending_object(&revs, o, NULL);
 127                 }
 128                 setup_revisions(0, NULL, &revs, NULL);
 129         }
 130         prepare_revision_walk(&revs);
 131         mark_edges_uninteresting(revs.commits, &revs, show_edge);
 132         traverse_commit_list(&revs, show_commit, show_object);
 133 }
 134
 135 static void create_pack_file(void)
 136 {
 137         /* Pipes between rev-list to pack-objects, pack-objects to us
 138          * and pack-objects error stream for progress bar.
 139          */
 140         int lp_pipe[2], pu_pipe[2], pe_pipe[2];
 141         pid_t pid_rev_list, pid_pack_objects;
 142         int create_full_pack = (nr_our_refs == want_obj.nr && !have_obj.nr);
 143         char data[8193], progress[128];
 144         char abort_msg[] = "aborting due to possible repository "
 145                 "corruption on the remote side.";
 146         int buffered = -1;
 147
 148         if (pipe(lp_pipe) < 0)
 149                 die("git-upload-pack: unable to create pipe");
 150         pid_rev_list = fork();
 151         if (pid_rev_list < 0)
 152                 die("git-upload-pack: unable to fork git-rev-list");
 153
 154         if (!pid_rev_list) {
 155                 pack_pipe = fdopen(lp_pipe[1], "w");
 156                 do_rev_list(create_full_pack);
 157                 exit(0);
 158         }
 159
 160         if (pipe(pu_pipe) < 0)
 161                 die("git-upload-pack: unable to create pipe");
 162         if (pipe(pe_pipe) < 0)
 163                 die("git-upload-pack: unable to create pipe");
 164         pid_pack_objects = fork();
 165         if (pid_pack_objects < 0) {
 166                 /* daemon sets things up to ignore TERM */
 167                 kill(pid_rev_list, SIGKILL);
 168                 die("git-upload-pack: unable to fork git-pack-objects");
 169         }
 170         if (!pid_pack_objects) {
 171                 dup2(lp_pipe[0], 0);
 172                 dup2(pu_pipe[1], 1);
 173                 dup2(pe_pipe[1], 2);
 174
 175                 close(lp_pipe[0]);
 176                 close(lp_pipe[1]);
 177                 close(pu_pipe[0]);
 178                 close(pu_pipe[1]);
 179                 close(pe_pipe[0]);
 180                 close(pe_pipe[1]);
 181                 execl_git_cmd("pack-objects", "--stdout", "--progress",
 182                               use_ofs_delta ? "--delta-base-offset" : NULL,
 183                               NULL);
 184                 kill(pid_rev_list, SIGKILL);
 185                 die("git-upload-pack: unable to exec git-pack-objects");
 186         }
 187
 188         close(lp_pipe[0]);
 189         close(lp_pipe[1]);
 190
 191         /* We read from pe_pipe[0] to capture stderr output for
 192          * progress bar, and pu_pipe[0] to capture the pack data.
 193          */
 194         close(pe_pipe[1]);
 195         close(pu_pipe[1]);
 196
 197         while (1) {
 198                 const char *who;
 199                 struct pollfd pfd[2];
 200                 pid_t pid;
 201                 int status;
 202                 ssize_t sz;
 203                 int pe, pu, pollsize;
 204
 205                 reset_timeout();
 206
 207                 pollsize = 0;
 208                 pe = pu = -1;
 209
 210                 if (0 <= pu_pipe[0]) {
 211                         pfd[pollsize].fd = pu_pipe[0];
 212                         pfd[pollsize].events = POLLIN;
 213                         pu = pollsize;
 214                         pollsize++;
 215                 }
 216                 if (0 <= pe_pipe[0]) {
 217                         pfd[pollsize].fd = pe_pipe[0];
 218                         pfd[pollsize].events = POLLIN;
 219                         pe = pollsize;
 220                         pollsize++;
 221                 }
 222
 223                 if (pollsize) {
 224                         if (poll(pfd, pollsize, -1) < 0) {
 225                                 if (errno != EINTR) {
 226                                         error("poll failed, resuming: %s",
 227                                               strerror(errno));
 228                                         sleep(1);
 229                                 }
 230                                 continue;
 231                         }
 232                         if (0 <= pu && (pfd[pu].revents & (POLLIN|POLLHUP))) {
 233                                 /* Data ready; we keep the last byte
 234                                  * to ourselves in case we detect
 235                                  * broken rev-list, so that we can
 236                                  * leave the stream corrupted.  This
 237                                  * is unfortunate -- unpack-objects
 238                                  * would happily accept a valid pack
 239                                  * data with trailing garbage, so
 240                                  * appending garbage after we pass all
 241                                  * the pack data is not good enough to
 242                                  * signal breakage to downstream.
 243                                  */
 244                                 char *cp = data;
 245                                 ssize_t outsz = 0;
 246                                 if (0 <= buffered) {
 247                                         *cp++ = buffered;
 248                                         outsz++;
 249                                 }
 250                                 sz = xread(pu_pipe[0], cp,
 251                                           sizeof(data) - outsz);
 252                                 if (0 < sz)
 253                                                 ;
 254                                 else if (sz == 0) {
 255                                         close(pu_pipe[0]);
 256                                         pu_pipe[0] = -1;
 257                                 }
 258                                 else
 259                                         goto fail;
 260                                 sz += outsz;
 261                                 if (1 < sz) {
 262                                         buffered = data[sz-1] & 0xFF;
 263                                         sz--;
 264                                 }
 265                                 else
 266                                         buffered = -1;
 267                                 sz = send_client_data(1, data, sz);
 268                                 if (sz < 0)
 269                                         goto fail;
 270                         }
 271                         if (0 <= pe && (pfd[pe].revents & (POLLIN|POLLHUP))) {
 272                                 /* Status ready; we ship that in the side-band
 273                                  * or dump to the standard error.
 274                                  */
 275                                 sz = xread(pe_pipe[0], progress,
 276                                           sizeof(progress));
 277                                 if (0 < sz)
 278                                         send_client_data(2, progress, sz);
 279                                 else if (sz == 0) {
 280                                         close(pe_pipe[0]);
 281                                         pe_pipe[0] = -1;
 282                                 }
 283                                 else
 284                                         goto fail;
 285                         }
 286                 }
 287
 288                 /* See if the children are still there */
 289                 if (pid_rev_list || pid_pack_objects) {
 290                         pid = waitpid(-1, &status, WNOHANG);
 291                         if (!pid)
 292                                 continue;
 293                         who = ((pid == pid_rev_list) ? "git-rev-list" :
 294                                (pid == pid_pack_objects) ? "git-pack-objects" :
 295                                NULL);
 296                         if (!who) {
 297                                 if (pid < 0) {
 298                                         error("git-upload-pack: %s",
 299                                               strerror(errno));
 300                                         goto fail;
 301                                 }
 302                                 error("git-upload-pack: we weren't "
 303                                       "waiting for %d", pid);
 304                                 continue;
 305                         }
 306                         if (!WIFEXITED(status) || WEXITSTATUS(status) > 0) {
 307                                 error("git-upload-pack: %s died with error.",
 308                                       who);
 309                                 goto fail;
 310                         }
 311                         if (pid == pid_rev_list)
 312                                 pid_rev_list = 0;
 313                         if (pid == pid_pack_objects)
 314                                 pid_pack_objects = 0;
 315                         if (pid_rev_list || pid_pack_objects)
 316                                 continue;
 317                 }
 318
 319                 /* both died happily */
 320                 if (pollsize)
 321                         continue;
 322
 323                 /* flush the data */
 324                 if (0 <= buffered) {
 325                         data[0] = buffered;
 326                         sz = send_client_data(1, data, 1);
 327                         if (sz < 0)
 328                                 goto fail;
 329                         fprintf(stderr, "flushed.\n");
 330                 }
 331                 if (use_sideband)
 332                         packet_flush(1);
 333                 return;
 334         }
 335  fail:
 336         if (pid_pack_objects)
 337                 kill(pid_pack_objects, SIGKILL);
 338         if (pid_rev_list)
 339                 kill(pid_rev_list, SIGKILL);
 340         send_client_data(3, abort_msg, sizeof(abort_msg));
 341         die("git-upload-pack: %s", abort_msg);
 342 }
 343
 344 static int got_sha1(char *hex, unsigned char *sha1)
 345 {
 346         struct object *o;
 347         int we_knew_they_have = 0;
 348
 349         if (get_sha1_hex(hex, sha1))
 350                 die("git-upload-pack: expected SHA1 object, got '%s'", hex);
 351         if (!has_sha1_file(sha1))
 352                 return -1;
 353
 354         o = lookup_object(sha1);
 355         if (!(o && o->parsed))
 356                 o = parse_object(sha1);
 357         if (!o)
 358                 die("oops (%s)", sha1_to_hex(sha1));
 359         if (o->type == OBJ_COMMIT) {
 360                 struct commit_list *parents;
 361                 struct commit *commit = (struct commit *)o;
 362                 if (o->flags & THEY_HAVE)
 363                         we_knew_they_have = 1;
 364                 else
 365                         o->flags |= THEY_HAVE;
 366                 if (!oldest_have || (commit->date < oldest_have))
 367                         oldest_have = commit->date;
 368                 for (parents = commit->parents;
 369                      parents;
 370                      parents = parents->next)
 371                         parents->item->object.flags |= THEY_HAVE;
 372         }
 373         if (!we_knew_they_have) {
 374                 add_object_array(o, NULL, &have_obj);
 375                 return 1;
 376         }
 377         return 0;
 378 }
 379
 380 static int reachable(struct commit *want)
 381 {
 382         struct commit_list *work = NULL;
 383
 384         insert_by_date(want, &work);
 385         while (work) {
 386                 struct commit_list *list = work->next;
 387                 struct commit *commit = work->item;
 388                 free(work);
 389                 work = list;
 390
 391                 if (commit->object.flags & THEY_HAVE) {
 392                         want->object.flags |= COMMON_KNOWN;
 393                         break;
 394                 }
 395                 if (!commit->object.parsed)
 396                         parse_object(commit->object.sha1);
 397                 if (commit->object.flags & REACHABLE)
 398                         continue;
 399                 commit->object.flags |= REACHABLE;
 400                 if (commit->date < oldest_have)
 401                         continue;
 402                 for (list = commit->parents; list; list = list->next) {
 403                         struct commit *parent = list->item;
 404                         if (!(parent->object.flags & REACHABLE))
 405                                 insert_by_date(parent, &work);
 406                 }
 407         }
 408         want->object.flags |= REACHABLE;
 409         clear_commit_marks(want, REACHABLE);
 410         free_commit_list(work);
 411         return (want->object.flags & COMMON_KNOWN);
 412 }
 413
 414 static int ok_to_give_up(void)
 415 {
 416         int i;
 417
 418         if (!have_obj.nr)
 419                 return 0;
 420
 421         for (i = 0; i < want_obj.nr; i++) {
 422                 struct object *want = want_obj.objects[i].item;
 423
 424                 if (want->flags & COMMON_KNOWN)
 425                         continue;
 426                 want = deref_tag(want, "a want line", 0);
 427                 if (!want || want->type != OBJ_COMMIT) {
 428                         /* no way to tell if this is reachable by
 429                          * looking at the ancestry chain alone, so
 430                          * leave a note to ourselves not to worry about
 431                          * this object anymore.
 432                          */
 433                         want_obj.objects[i].item->flags |= COMMON_KNOWN;
 434                         continue;
 435                 }
 436                 if (!reachable((struct commit *)want))
 437                         return 0;
 438         }
 439         return 1;
 440 }
 441
 442 static int get_common_commits(void)
 443 {
 444         static char line[1000];
 445         unsigned char sha1[20];
 446         char hex[41], last_hex[41];
 447         int len;
 448
 449         track_object_refs = 0;
 450         save_commit_buffer = 0;
 451
 452         for(;;) {
 453                 len = packet_read_line(0, line, sizeof(line));
 454                 reset_timeout();
 455
 456                 if (!len) {
 457                         if (have_obj.nr == 0 || multi_ack)
 458                                 packet_write(1, "NAK\n");
 459                         continue;
 460                 }
 461                 len = strip(line, len);
 462                 if (!strncmp(line, "have ", 5)) {
 463                         switch (got_sha1(line+5, sha1)) {
 464                         case -1: /* they have what we do not */
 465                                 if (multi_ack && ok_to_give_up())
 466                                         packet_write(1, "ACK %s continue\n",
 467                                                      sha1_to_hex(sha1));
 468                                 break;
 469                         default:
 470                                 memcpy(hex, sha1_to_hex(sha1), 41);
 471                                 if (multi_ack) {
 472                                         const char *msg = "ACK %s continue\n";
 473                                         packet_write(1, msg, hex);
 474                                         memcpy(last_hex, hex, 41);
 475                                 }
 476                                 else if (have_obj.nr == 1)
 477                                         packet_write(1, "ACK %s\n", hex);
 478                                 break;
 479                         }
 480                         continue;
 481                 }
 482                 if (!strcmp(line, "done")) {
 483                         if (have_obj.nr > 0) {
 484                                 if (multi_ack)
 485                                         packet_write(1, "ACK %s\n", last_hex);
 486                                 return 0;
 487                         }
 488                         packet_write(1, "NAK\n");
 489                         return -1;
 490                 }
 491                 die("git-upload-pack: expected SHA1 list, got '%s'", line);
 492         }
 493 }
 494
 495 static void receive_needs(void)
 496 {
 497         struct object_array shallows = {0, 0, NULL};
 498         static char line[1000];
 499         int len, depth = 0;
 500
 501         for (;;) {
 502                 struct object *o;
 503                 unsigned char sha1_buf[20];
 504                 len = packet_read_line(0, line, sizeof(line));
 505                 reset_timeout();
 506                 if (!len)
 507                         break;
 508
 509                 if (!strncmp("shallow ", line, 8)) {
 510                         unsigned char sha1[20];
 511                         struct object *object;
 512                         use_thin_pack = 0;
 513                         if (get_sha1(line + 8, sha1))
 514                                 die("invalid shallow line: %s", line);
 515                         object = parse_object(sha1);
 516                         if (!object)
 517                                 die("did not find object for %s", line);
 518                         object->flags |= CLIENT_SHALLOW;
 519                         add_object_array(object, NULL, &shallows);
 520                         continue;
 521                 }
 522                 if (!strncmp("deepen ", line, 7)) {
 523                         char *end;
 524                         use_thin_pack = 0;
 525                         depth = strtol(line + 7, &end, 0);
 526                         if (end == line + 7 || depth <= 0)
 527                                 die("Invalid deepen: %s", line);
 528                         continue;
 529                 }
 530                 if (strncmp("want ", line, 5) ||
 531                     get_sha1_hex(line+5, sha1_buf))
 532                         die("git-upload-pack: protocol error, "
 533                             "expected to get sha, not '%s'", line);
 534                 if (strstr(line+45, "multi_ack"))
 535                         multi_ack = 1;
 536                 if (strstr(line+45, "thin-pack"))
 537                         use_thin_pack = 1;
 538                 if (strstr(line+45, "ofs-delta"))
 539                         use_ofs_delta = 1;
 540                 if (strstr(line+45, "side-band-64k"))
 541                         use_sideband = LARGE_PACKET_MAX;
 542                 else if (strstr(line+45, "side-band"))
 543                         use_sideband = DEFAULT_PACKET_MAX;
 544
 545                 /* We have sent all our refs already, and the other end
 546                  * should have chosen out of them; otherwise they are
 547                  * asking for nonsense.
 548                  *
 549                  * Hmph.  We may later want to allow "want" line that
 550                  * asks for something like "master~10" (symbolic)...
 551                  * would it make sense?  I don't know.
 552                  */
 553                 o = lookup_object(sha1_buf);
 554                 if (!o || !(o->flags & OUR_REF))
 555                         die("git-upload-pack: not our ref %s", line+5);
 556                 if (!(o->flags & WANTED)) {
 557                         o->flags |= WANTED;
 558                         add_object_array(o, NULL, &want_obj);
 559                 }
 560         }
 561         if (depth == 0 && shallows.nr == 0)
 562                 return;
 563         if (depth > 0) {
 564                 struct commit_list *result, *backup;
 565                 int i;
 566                 backup = result = get_shallow_commits(&want_obj, depth,
 567                         SHALLOW, NOT_SHALLOW);
 568                 while (result) {
 569                         struct object *object = &result->item->object;
 570                         if (!(object->flags & (CLIENT_SHALLOW|NOT_SHALLOW))) {
 571                                 packet_write(1, "shallow %s",
 572                                                 sha1_to_hex(object->sha1));
 573                                 register_shallow(object->sha1);
 574                         }
 575                         result = result->next;
 576                 }
 577                 free_commit_list(backup);
 578                 for (i = 0; i < shallows.nr; i++) {
 579                         struct object *object = shallows.objects[i].item;
 580                         if (object->flags & NOT_SHALLOW) {
 581                                 struct commit_list *parents;
 582                                 packet_write(1, "unshallow %s",
 583                                         sha1_to_hex(object->sha1));
 584                                 object->flags &= ~CLIENT_SHALLOW;
 585                                 /* make sure the real parents are parsed */
 586                                 unregister_shallow(object->sha1);
 587                                 object->parsed = 0;
 588                                 parse_commit((struct commit *)object);
 589                                 parents = ((struct commit *)object)->parents;
 590                                 while (parents) {
 591                                         add_object_array(&parents->item->object,
 592                                                         NULL, &want_obj);
 593                                         parents = parents->next;
 594                                 }
 595                         }
 596                         /* make sure commit traversal conforms to client */
 597                         register_shallow(object->sha1);
 598                 }
 599                 packet_flush(1);
 600         } else
 601                 if (shallows.nr > 0) {
 602                         int i;
 603                         for (i = 0; i < shallows.nr; i++)
 604                                 register_shallow(shallows.objects[i].item->sha1);
 605                 }
 606         free(shallows.objects);
 607 }
 608
 609 static int send_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 610 {
 611         static const char *capabilities = "multi_ack thin-pack side-band"
 612                 " side-band-64k ofs-delta shallow";
 613         struct object *o = parse_object(sha1);
 614
 615         if (!o)
 616                 die("git-upload-pack: cannot find object %s:", sha1_to_hex(sha1));
 617
 618         if (capabilities)
 619                 packet_write(1, "%s %s%c%s\n", sha1_to_hex(sha1), refname,
 620                         0, capabilities);
 621         else
 622                 packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
 623         capabilities = NULL;
 624         if (!(o->flags & OUR_REF)) {
 625                 o->flags |= OUR_REF;
 626                 nr_our_refs++;
 627         }
 628         if (o->type == OBJ_TAG) {
 629                 o = deref_tag(o, refname, 0);
 630                 packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
 631         }
 632         return 0;
 633 }
 634
 635 static void upload_pack(void)
 636 {
 637         reset_timeout();
 638         head_ref(send_ref, NULL);
 639         for_each_ref(send_ref, NULL);
 640         packet_flush(1);
 641         receive_needs();
 642         if (want_obj.nr) {
 643                 get_common_commits();
 644                 create_pack_file();
 645         }
 646 }
 647
 648 int main(int argc, char **argv)
 649 {
 650         char *dir;
 651         int i;
 652         int strict = 0;
 653
 654         for (i = 1; i < argc; i++) {
 655                 char *arg = argv[i];
 656
 657                 if (arg[0] != '-')
 658                         break;
 659                 if (!strcmp(arg, "--strict")) {
 660                         strict = 1;
 661                         continue;
 662                 }
 663                 if (!strncmp(arg, "--timeout=", 10)) {
 664                         timeout = atoi(arg+10);
 665                         continue;
 666                 }
 667                 if (!strcmp(arg, "--")) {
 668                         i++;
 669                         break;
 670                 }
 671         }
 672
 673         if (i != argc-1)
 674                 usage(upload_pack_usage);
 675         dir = argv[i];
 676
 677         if (!enter_repo(dir, strict))
 678                 die("'%s': unable to chdir or not a git archive", dir);
 679
 680         upload_pack();
 681         return 0;
 682 }