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