upload-pack.c

   1 #include <signal.h>
   2 #include <sys/wait.h>
   3 #include <sys/poll.h>
   4 #include "cache.h"
   5 #include "refs.h"
   6 #include "pkt-line.h"
   7 #include "sideband.h"
   8 #include "tag.h"
   9 #include "object.h"
  10 #include "commit.h"
  11 #include "exec_cmd.h"
  12 #include "diff.h"
  13 #include "revision.h"
  14 #include "list-objects.h"
  15
  16 static const char upload_pack_usage[] = "git-upload-pack [--strict] [--timeout=nn] <dir>";
  17
  18 /* bits #0..7 in revision.h, #8..10 in commit.c */
  19 #define THEY_HAVE       (1u << 11)
  20 #define OUR_REF         (1u << 12)
  21 #define WANTED          (1u << 13)
  22 #define COMMON_KNOWN    (1u << 14)
  23 #define REACHABLE       (1u << 15)
  24
  25 #define SHALLOW         (1u << 16)
  26 #define NOT_SHALLOW     (1u << 17)
  27 #define CLIENT_SHALLOW  (1u << 18)
  28
  29 static unsigned long oldest_have;
  30
  31 static int multi_ack, nr_our_refs;
  32 static int use_thin_pack, use_ofs_delta;
  33 static struct object_array have_obj;
  34 static struct object_array want_obj;
  35 static unsigned int timeout;
  36 /* 0 for no sideband,
  37  * otherwise maximum packet size (up to 65520 bytes).
  38  */
  39 static int use_sideband;
  40
  41 static void reset_timeout(void)
  42 {
  43         alarm(timeout);
  44 }
  45
  46 static int strip(char *line, int len)
  47 {
  48         if (len && line[len-1] == '\n')
  49                 line[--len] = 0;
  50         return len;
  51 }
  52
  53 static ssize_t send_client_data(int fd, const char *data, ssize_t sz)
  54 {
  55         if (use_sideband)
  56                 return send_sideband(1, fd, data, sz, use_sideband);
  57         if (fd == 3)
  58                 /* emergency quit */
  59                 fd = 2;
  60         if (fd == 2) {
  61                 xwrite(fd, data, sz);
  62                 return sz;
  63         }
  64         return safe_write(fd, data, sz);
  65 }
  66
  67 FILE *pack_pipe = NULL;
  68 static void show_commit(struct commit *commit)
  69 {
  70         if (commit->object.flags & BOUNDARY)
  71                 fputc('-', pack_pipe);
  72         if (fputs(sha1_to_hex(commit->object.sha1), pack_pipe) < 0)
  73                 die("broken output pipe");
  74         fputc('\n', pack_pipe);
  75         fflush(pack_pipe);
  76         free(commit->buffer);
  77         commit->buffer = NULL;
  78 }
  79
  80 static void show_object(struct object_array_entry *p)
  81 {
  82         /* An object with name "foo\n0000000..." can be used to
  83          * confuse downstream git-pack-objects very badly.
  84          */
  85         const char *ep = strchr(p->name, '\n');
  86         if (ep) {
  87                 fprintf(pack_pipe, "%s %.*s\n", sha1_to_hex(p->item->sha1),
  88                        (int) (ep - p->name),
  89                        p->name);
  90         }
  91         else
  92                 fprintf(pack_pipe, "%s %s\n",
  93                                 sha1_to_hex(p->item->sha1), p->name);
  94 }
  95
  96 static void show_edge(struct commit *commit)
  97 {
  98         fprintf(pack_pipe, "-%s\n", sha1_to_hex(commit->object.sha1));
  99 }
 100
 101 static void create_pack_file(void)
 102 {
 103         /* Pipes between rev-list to pack-objects, pack-objects to us
 104          * and pack-objects error stream for progress bar.
 105          */
 106         int lp_pipe[2], pu_pipe[2], pe_pipe[2];
 107         pid_t pid_rev_list, pid_pack_objects;
 108         int create_full_pack = (nr_our_refs == want_obj.nr && !have_obj.nr);
 109         char data[8193], progress[128];
 110         char abort_msg[] = "aborting due to possible repository "
 111                 "corruption on the remote side.";
 112         int buffered = -1;
 113
 114         if (pipe(lp_pipe) < 0)
 115                 die("git-upload-pack: unable to create pipe");
 116         pid_rev_list = fork();
 117         if (pid_rev_list < 0)
 118                 die("git-upload-pack: unable to fork git-rev-list");
 119
 120         if (!pid_rev_list) {
 121                 int i;
 122                 struct rev_info revs;
 123
 124                 pack_pipe = fdopen(lp_pipe[1], "w");
 125
 126                 if (create_full_pack)
 127                         use_thin_pack = 0; /* no point doing it */
 128                 init_revisions(&revs, NULL);
 129                 revs.tag_objects = 1;
 130                 revs.tree_objects = 1;
 131                 revs.blob_objects = 1;
 132                 if (use_thin_pack)
 133                         revs.edge_hint = 1;
 134
 135                 if (create_full_pack) {
 136                         const char *args[] = {"rev-list", "--all", NULL};
 137                         setup_revisions(2, args, &revs, NULL);
 138                 } else {
 139                         for (i = 0; i < want_obj.nr; i++) {
 140                                 struct object *o = want_obj.objects[i].item;
 141                                 /* why??? */
 142                                 o->flags &= ~UNINTERESTING;
 143                                 add_pending_object(&revs, o, NULL);
 144                         }
 145                         for (i = 0; i < have_obj.nr; i++) {
 146                                 struct object *o = have_obj.objects[i].item;
 147                                 o->flags |= UNINTERESTING;
 148                                 add_pending_object(&revs, o, NULL);
 149                         }
 150                         setup_revisions(0, NULL, &revs, NULL);
 151                 }
 152                 prepare_revision_walk(&revs);
 153                 mark_edges_uninteresting(revs.commits, &revs, show_edge);
 154                 traverse_commit_list(&revs, show_commit, show_object);
 155                 exit(0);
 156         }
 157
 158         if (pipe(pu_pipe) < 0)
 159                 die("git-upload-pack: unable to create pipe");
 160         if (pipe(pe_pipe) < 0)
 161                 die("git-upload-pack: unable to create pipe");
 162         pid_pack_objects = fork();
 163         if (pid_pack_objects < 0) {
 164                 /* daemon sets things up to ignore TERM */
 165                 kill(pid_rev_list, SIGKILL);
 166                 die("git-upload-pack: unable to fork git-pack-objects");
 167         }
 168         if (!pid_pack_objects) {
 169                 dup2(lp_pipe[0], 0);
 170                 dup2(pu_pipe[1], 1);
 171                 dup2(pe_pipe[1], 2);
 172
 173                 close(lp_pipe[0]);
 174                 close(lp_pipe[1]);
 175                 close(pu_pipe[0]);
 176                 close(pu_pipe[1]);
 177                 close(pe_pipe[0]);
 178                 close(pe_pipe[1]);
 179                 execl_git_cmd("pack-objects", "--stdout", "--progress",
 180                               use_ofs_delta ? "--delta-base-offset" : NULL,
 181                               NULL);
 182                 kill(pid_rev_list, SIGKILL);
 183                 die("git-upload-pack: unable to exec git-pack-objects");
 184         }
 185
 186         close(lp_pipe[0]);
 187         close(lp_pipe[1]);
 188
 189         /* We read from pe_pipe[0] to capture stderr output for
 190          * progress bar, and pu_pipe[0] to capture the pack data.
 191          */
 192         close(pe_pipe[1]);
 193         close(pu_pipe[1]);
 194
 195         while (1) {
 196                 const char *who;
 197                 struct pollfd pfd[2];
 198                 pid_t pid;
 199                 int status;
 200                 ssize_t sz;
 201                 int pe, pu, pollsize;
 202
 203                 reset_timeout();
 204
 205                 pollsize = 0;
 206                 pe = pu = -1;
 207
 208                 if (0 <= pu_pipe[0]) {
 209                         pfd[pollsize].fd = pu_pipe[0];
 210                         pfd[pollsize].events = POLLIN;
 211                         pu = pollsize;
 212                         pollsize++;
 213                 }
 214                 if (0 <= pe_pipe[0]) {
 215                         pfd[pollsize].fd = pe_pipe[0];
 216                         pfd[pollsize].events = POLLIN;
 217                         pe = pollsize;
 218                         pollsize++;
 219                 }
 220
 221                 if (pollsize) {
 222                         if (poll(pfd, pollsize, -1) < 0) {
 223                                 if (errno != EINTR) {
 224                                         error("poll failed, resuming: %s",
 225                                               strerror(errno));
 226                                         sleep(1);
 227                                 }
 228                                 continue;
 229                         }
 230                         if (0 <= pu && (pfd[pu].revents & (POLLIN|POLLHUP))) {
 231                                 /* Data ready; we keep the last byte
 232                                  * to ourselves in case we detect
 233                                  * broken rev-list, so that we can
 234                                  * leave the stream corrupted.  This
 235                                  * is unfortunate -- unpack-objects
 236                                  * would happily accept a valid pack
 237                                  * data with trailing garbage, so
 238                                  * appending garbage after we pass all
 239                                  * the pack data is not good enough to
 240                                  * signal breakage to downstream.
 241                                  */
 242                                 char *cp = data;
 243                                 ssize_t outsz = 0;
 244                                 if (0 <= buffered) {
 245                                         *cp++ = buffered;
 246                                         outsz++;
 247                                 }
 248                                 sz = read(pu_pipe[0], cp,
 249                                           sizeof(data) - outsz);
 250                                 if (0 < sz)
 251                                                 ;
 252                                 else if (sz == 0) {
 253                                         close(pu_pipe[0]);
 254                                         pu_pipe[0] = -1;
 255                                 }
 256                                 else
 257                                         goto fail;
 258                                 sz += outsz;
 259                                 if (1 < sz) {
 260                                         buffered = data[sz-1] & 0xFF;
 261                                         sz--;
 262                                 }
 263                                 else
 264                                         buffered = -1;
 265                                 sz = send_client_data(1, data, sz);
 266                                 if (sz < 0)
 267                                         goto fail;
 268                         }
 269                         if (0 <= pe && (pfd[pe].revents & (POLLIN|POLLHUP))) {
 270                                 /* Status ready; we ship that in the side-band
 271                                  * or dump to the standard error.
 272                                  */
 273                                 sz = read(pe_pipe[0], progress,
 274                                           sizeof(progress));
 275                                 if (0 < sz)
 276                                         send_client_data(2, progress, sz);
 277                                 else if (sz == 0) {
 278                                         close(pe_pipe[0]);
 279                                         pe_pipe[0] = -1;
 280                                 }
 281                                 else
 282                                         goto fail;
 283                         }
 284                 }
 285
 286                 /* See if the children are still there */
 287                 if (pid_rev_list || pid_pack_objects) {
 288                         pid = waitpid(-1, &status, WNOHANG);
 289                         if (!pid)
 290                                 continue;
 291                         who = ((pid == pid_rev_list) ? "git-rev-list" :
 292                                (pid == pid_pack_objects) ? "git-pack-objects" :
 293                                NULL);
 294                         if (!who) {
 295                                 if (pid < 0) {
 296                                         error("git-upload-pack: %s",
 297                                               strerror(errno));
 298                                         goto fail;
 299                                 }
 300                                 error("git-upload-pack: we weren't "
 301                                       "waiting for %d", pid);
 302                                 continue;
 303                         }
 304                         if (!WIFEXITED(status) || WEXITSTATUS(status) > 0) {
 305                                 error("git-upload-pack: %s died with error.",
 306                                       who);
 307                                 goto fail;
 308                         }
 309                         if (pid == pid_rev_list)
 310                                 pid_rev_list = 0;
 311                         if (pid == pid_pack_objects)
 312                                 pid_pack_objects = 0;
 313                         if (pid_rev_list || pid_pack_objects)
 314                                 continue;
 315                 }
 316
 317                 /* both died happily */
 318                 if (pollsize)
 319                         continue;
 320
 321                 /* flush the data */
 322                 if (0 <= buffered) {
 323                         data[0] = buffered;
 324                         sz = send_client_data(1, data, 1);
 325                         if (sz < 0)
 326                                 goto fail;
 327                         fprintf(stderr, "flushed.\n");
 328                 }
 329                 if (use_sideband)
 330                         packet_flush(1);
 331                 return;
 332         }
 333  fail:
 334         if (pid_pack_objects)
 335                 kill(pid_pack_objects, SIGKILL);
 336         if (pid_rev_list)
 337                 kill(pid_rev_list, SIGKILL);
 338         send_client_data(3, abort_msg, sizeof(abort_msg));
 339         die("git-upload-pack: %s", abort_msg);
 340 }
 341
 342 static int got_sha1(char *hex, unsigned char *sha1)
 343 {
 344         struct object *o;
 345         int we_knew_they_have = 0;
 346
 347         if (get_sha1_hex(hex, sha1))
 348                 die("git-upload-pack: expected SHA1 object, got '%s'", hex);
 349         if (!has_sha1_file(sha1))
 350                 return -1;
 351
 352         o = lookup_object(sha1);
 353         if (!(o && o->parsed))
 354                 o = parse_object(sha1);
 355         if (!o)
 356                 die("oops (%s)", sha1_to_hex(sha1));
 357         if (o->type == OBJ_COMMIT) {
 358                 struct commit_list *parents;
 359                 struct commit *commit = (struct commit *)o;
 360                 if (o->flags & THEY_HAVE)
 361                         we_knew_they_have = 1;
 362                 else
 363                         o->flags |= THEY_HAVE;
 364                 if (!oldest_have || (commit->date < oldest_have))
 365                         oldest_have = commit->date;
 366                 for (parents = commit->parents;
 367                      parents;
 368                      parents = parents->next)
 369                         parents->item->object.flags |= THEY_HAVE;
 370         }
 371         if (!we_knew_they_have) {
 372                 add_object_array(o, NULL, &have_obj);
 373                 return 1;
 374         }
 375         return 0;
 376 }
 377
 378 static int reachable(struct commit *want)
 379 {
 380         struct commit_list *work = NULL;
 381
 382         insert_by_date(want, &work);
 383         while (work) {
 384                 struct commit_list *list = work->next;
 385                 struct commit *commit = work->item;
 386                 free(work);
 387                 work = list;
 388
 389                 if (commit->object.flags & THEY_HAVE) {
 390                         want->object.flags |= COMMON_KNOWN;
 391                         break;
 392                 }
 393                 if (!commit->object.parsed)
 394                         parse_object(commit->object.sha1);
 395                 if (commit->object.flags & REACHABLE)
 396                         continue;
 397                 commit->object.flags |= REACHABLE;
 398                 if (commit->date < oldest_have)
 399                         continue;
 400                 for (list = commit->parents; list; list = list->next) {
 401                         struct commit *parent = list->item;
 402                         if (!(parent->object.flags & REACHABLE))
 403                                 insert_by_date(parent, &work);
 404                 }
 405         }
 406         want->object.flags |= REACHABLE;
 407         clear_commit_marks(want, REACHABLE);
 408         free_commit_list(work);
 409         return (want->object.flags & COMMON_KNOWN);
 410 }
 411
 412 static int ok_to_give_up(void)
 413 {
 414         int i;
 415
 416         if (!have_obj.nr)
 417                 return 0;
 418
 419         for (i = 0; i < want_obj.nr; i++) {
 420                 struct object *want = want_obj.objects[i].item;
 421
 422                 if (want->flags & COMMON_KNOWN)
 423                         continue;
 424                 want = deref_tag(want, "a want line", 0);
 425                 if (!want || want->type != OBJ_COMMIT) {
 426                         /* no way to tell if this is reachable by
 427                          * looking at the ancestry chain alone, so
 428                          * leave a note to ourselves not to worry about
 429                          * this object anymore.
 430                          */
 431                         want_obj.objects[i].item->flags |= COMMON_KNOWN;
 432                         continue;
 433                 }
 434                 if (!reachable((struct commit *)want))
 435                         return 0;
 436         }
 437         return 1;
 438 }
 439
 440 static int get_common_commits(void)
 441 {
 442         static char line[1000];
 443         unsigned char sha1[20];
 444         char hex[41], last_hex[41];
 445         int len;
 446
 447         track_object_refs = 0;
 448         save_commit_buffer = 0;
 449
 450         for(;;) {
 451                 len = packet_read_line(0, line, sizeof(line));
 452                 reset_timeout();
 453
 454                 if (!len) {
 455                         if (have_obj.nr == 0 || multi_ack)
 456                                 packet_write(1, "NAK\n");
 457                         continue;
 458                 }
 459                 len = strip(line, len);
 460                 if (!strncmp(line, "have ", 5)) {
 461                         switch (got_sha1(line+5, sha1)) {
 462                         case -1: /* they have what we do not */
 463                                 if (multi_ack && ok_to_give_up())
 464                                         packet_write(1, "ACK %s continue\n",
 465                                                      sha1_to_hex(sha1));
 466                                 break;
 467                         default:
 468                                 memcpy(hex, sha1_to_hex(sha1), 41);
 469                                 if (multi_ack) {
 470                                         const char *msg = "ACK %s continue\n";
 471                                         packet_write(1, msg, hex);
 472                                         memcpy(last_hex, hex, 41);
 473                                 }
 474                                 else if (have_obj.nr == 1)
 475                                         packet_write(1, "ACK %s\n", hex);
 476                                 break;
 477                         }
 478                         continue;
 479                 }
 480                 if (!strcmp(line, "done")) {
 481                         if (have_obj.nr > 0) {
 482                                 if (multi_ack)
 483                                         packet_write(1, "ACK %s\n", last_hex);
 484                                 return 0;
 485                         }
 486                         packet_write(1, "NAK\n");
 487                         return -1;
 488                 }
 489                 die("git-upload-pack: expected SHA1 list, got '%s'", line);
 490         }
 491 }
 492
 493 static void receive_needs(void)
 494 {
 495         struct object_array shallows = {0, 0, NULL};
 496         static char line[1000];
 497         int len, depth = 0;
 498
 499         for (;;) {
 500                 struct object *o;
 501                 unsigned char sha1_buf[20];
 502                 len = packet_read_line(0, line, sizeof(line));
 503                 reset_timeout();
 504                 if (!len)
 505                         break;
 506
 507                 if (!strncmp("shallow ", line, 8)) {
 508                         unsigned char sha1[20];
 509                         struct object *object;
 510                         use_thin_pack = 0;
 511                         if (get_sha1(line + 8, sha1))
 512                                 die("invalid shallow line: %s", line);
 513                         object = parse_object(sha1);
 514                         if (!object)
 515                                 die("did not find object for %s", line);
 516                         object->flags |= CLIENT_SHALLOW;
 517                         add_object_array(object, NULL, &shallows);
 518                         continue;
 519                 }
 520                 if (!strncmp("deepen ", line, 7)) {
 521                         char *end;
 522                         use_thin_pack = 0;
 523                         depth = strtol(line + 7, &end, 0);
 524                         if (end == line + 7 || depth <= 0)
 525                                 die("Invalid deepen: %s", line);
 526                         continue;
 527                 }
 528                 if (strncmp("want ", line, 5) ||
 529                     get_sha1_hex(line+5, sha1_buf))
 530                         die("git-upload-pack: protocol error, "
 531                             "expected to get sha, not '%s'", line);
 532                 if (strstr(line+45, "multi_ack"))
 533                         multi_ack = 1;
 534                 if (strstr(line+45, "thin-pack"))
 535                         use_thin_pack = 1;
 536                 if (strstr(line+45, "ofs-delta"))
 537                         use_ofs_delta = 1;
 538                 if (strstr(line+45, "side-band-64k"))
 539                         use_sideband = LARGE_PACKET_MAX;
 540                 else if (strstr(line+45, "side-band"))
 541                         use_sideband = DEFAULT_PACKET_MAX;
 542
 543                 /* We have sent all our refs already, and the other end
 544                  * should have chosen out of them; otherwise they are
 545                  * asking for nonsense.
 546                  *
 547                  * Hmph.  We may later want to allow "want" line that
 548                  * asks for something like "master~10" (symbolic)...
 549                  * would it make sense?  I don't know.
 550                  */
 551                 o = lookup_object(sha1_buf);
 552                 if (!o || !(o->flags & OUR_REF))
 553                         die("git-upload-pack: not our ref %s", line+5);
 554                 if (!(o->flags & WANTED)) {
 555                         o->flags |= WANTED;
 556                         add_object_array(o, NULL, &want_obj);
 557                 }
 558         }
 559         if (depth == 0 && shallows.nr == 0)
 560                 return;
 561         if (depth > 0) {
 562                 struct commit_list *result, *backup;
 563                 int i;
 564                 backup = result = get_shallow_commits(&want_obj, depth,
 565                         SHALLOW, NOT_SHALLOW);
 566                 while (result) {
 567                         struct object *object = &result->item->object;
 568                         if (!(object->flags & CLIENT_SHALLOW)) {
 569                                 packet_write(1, "shallow %s",
 570                                                 sha1_to_hex(object->sha1));
 571                                 register_shallow(object->sha1);
 572                         }
 573                         result = result->next;
 574                 }
 575                 free_commit_list(backup);
 576                 for (i = 0; i < shallows.nr; i++) {
 577                         struct object *object = shallows.objects[i].item;
 578                         if (object->flags & NOT_SHALLOW) {
 579                                 struct commit_list *parents;
 580                                 packet_write(1, "unshallow %s",
 581                                         sha1_to_hex(object->sha1));
 582                                 object->flags &= ~CLIENT_SHALLOW;
 583                                 /* make sure the real parents are parsed */
 584                                 unregister_shallow(object->sha1);
 585                                 object->parsed = 0;
 586                                 parse_commit((struct commit *)object);
 587                                 parents = ((struct commit *)object)->parents;
 588                                 while (parents) {
 589                                         add_object_array(&parents->item->object,
 590                                                         NULL, &want_obj);
 591                                         parents = parents->next;
 592                                 }
 593                         }
 594                         /* make sure commit traversal conforms to client */
 595                         register_shallow(object->sha1);
 596                 }
 597                 packet_flush(1);
 598         } else
 599                 if (shallows.nr > 0) {
 600                         int i;
 601                         for (i = 0; i < shallows.nr; i++)
 602                                 register_shallow(shallows.objects[i].item->sha1);
 603                 }
 604         free(shallows.objects);
 605 }
 606
 607 static int send_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 608 {
 609         static const char *capabilities = "multi_ack thin-pack side-band"
 610                 " side-band-64k ofs-delta shallow";
 611         struct object *o = parse_object(sha1);
 612
 613         if (!o)
 614                 die("git-upload-pack: cannot find object %s:", sha1_to_hex(sha1));
 615
 616         if (capabilities)
 617                 packet_write(1, "%s %s%c%s\n", sha1_to_hex(sha1), refname,
 618                         0, capabilities);
 619         else
 620                 packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
 621         capabilities = NULL;
 622         if (!(o->flags & OUR_REF)) {
 623                 o->flags |= OUR_REF;
 624                 nr_our_refs++;
 625         }
 626         if (o->type == OBJ_TAG) {
 627                 o = deref_tag(o, refname, 0);
 628                 packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
 629         }
 630         return 0;
 631 }
 632
 633 static void upload_pack(void)
 634 {
 635         reset_timeout();
 636         head_ref(send_ref, NULL);
 637         for_each_ref(send_ref, NULL);
 638         packet_flush(1);
 639         receive_needs();
 640         if (want_obj.nr) {
 641                 get_common_commits();
 642                 create_pack_file();
 643         }
 644 }
 645
 646 int main(int argc, char **argv)
 647 {
 648         char *dir;
 649         int i;
 650         int strict = 0;
 651
 652         for (i = 1; i < argc; i++) {
 653                 char *arg = argv[i];
 654
 655                 if (arg[0] != '-')
 656                         break;
 657                 if (!strcmp(arg, "--strict")) {
 658                         strict = 1;
 659                         continue;
 660                 }
 661                 if (!strncmp(arg, "--timeout=", 10)) {
 662                         timeout = atoi(arg+10);
 663                         continue;
 664                 }
 665                 if (!strcmp(arg, "--")) {
 666                         i++;
 667                         break;
 668                 }
 669         }
 670
 671         if (i != argc-1)
 672                 usage(upload_pack_usage);
 673         dir = argv[i];
 674
 675         if (!enter_repo(dir, strict))
 676                 die("'%s': unable to chdir or not a git archive", dir);
 677
 678         upload_pack();
 679         return 0;
 680 }