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