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