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