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                                 o->flags &= ~UNINTERESTING;
 142                                 add_pending_object(&revs, o, NULL);
 143                         }
 144                         for (i = 0; i < have_obj.nr; i++) {
 145                                 struct object *o = have_obj.objects[i].item;
 146                                 o->flags |= UNINTERESTING;
 147                                 add_pending_object(&revs, o, NULL);
 148                         }
 149                         setup_revisions(0, NULL, &revs, NULL);
 150                 }
 151                 prepare_revision_walk(&revs);
 152                 mark_edges_uninteresting(revs.commits, &revs, show_edge);
 153                 traverse_commit_list(&revs, show_commit, show_object);
 154                 exit(0);
 155         }
 156
 157         if (pipe(pu_pipe) < 0)
 158                 die("git-upload-pack: unable to create pipe");
 159         if (pipe(pe_pipe) < 0)
 160                 die("git-upload-pack: unable to create pipe");
 161         pid_pack_objects = fork();
 162         if (pid_pack_objects < 0) {
 163                 /* daemon sets things up to ignore TERM */
 164                 kill(pid_rev_list, SIGKILL);
 165                 die("git-upload-pack: unable to fork git-pack-objects");
 166         }
 167         if (!pid_pack_objects) {
 168                 dup2(lp_pipe[0], 0);
 169                 dup2(pu_pipe[1], 1);
 170                 dup2(pe_pipe[1], 2);
 171
 172                 close(lp_pipe[0]);
 173                 close(lp_pipe[1]);
 174                 close(pu_pipe[0]);
 175                 close(pu_pipe[1]);
 176                 close(pe_pipe[0]);
 177                 close(pe_pipe[1]);
 178                 execl_git_cmd("pack-objects", "--stdout", "--progress",
 179                               use_ofs_delta ? "--delta-base-offset" : NULL,
 180                               NULL);
 181                 kill(pid_rev_list, SIGKILL);
 182                 die("git-upload-pack: unable to exec git-pack-objects");
 183         }
 184
 185         close(lp_pipe[0]);
 186         close(lp_pipe[1]);
 187
 188         /* We read from pe_pipe[0] to capture stderr output for
 189          * progress bar, and pu_pipe[0] to capture the pack data.
 190          */
 191         close(pe_pipe[1]);
 192         close(pu_pipe[1]);
 193
 194         while (1) {
 195                 const char *who;
 196                 struct pollfd pfd[2];
 197                 pid_t pid;
 198                 int status;
 199                 ssize_t sz;
 200                 int pe, pu, pollsize;
 201
 202                 reset_timeout();
 203
 204                 pollsize = 0;
 205                 pe = pu = -1;
 206
 207                 if (0 <= pu_pipe[0]) {
 208                         pfd[pollsize].fd = pu_pipe[0];
 209                         pfd[pollsize].events = POLLIN;
 210                         pu = pollsize;
 211                         pollsize++;
 212                 }
 213                 if (0 <= pe_pipe[0]) {
 214                         pfd[pollsize].fd = pe_pipe[0];
 215                         pfd[pollsize].events = POLLIN;
 216                         pe = pollsize;
 217                         pollsize++;
 218                 }
 219
 220                 if (pollsize) {
 221                         if (poll(pfd, pollsize, -1) < 0) {
 222                                 if (errno != EINTR) {
 223                                         error("poll failed, resuming: %s",
 224                                               strerror(errno));
 225                                         sleep(1);
 226                                 }
 227                                 continue;
 228                         }
 229                         if (0 <= pu && (pfd[pu].revents & (POLLIN|POLLHUP))) {
 230                                 /* Data ready; we keep the last byte
 231                                  * to ourselves in case we detect
 232                                  * broken rev-list, so that we can
 233                                  * leave the stream corrupted.  This
 234                                  * is unfortunate -- unpack-objects
 235                                  * would happily accept a valid pack
 236                                  * data with trailing garbage, so
 237                                  * appending garbage after we pass all
 238                                  * the pack data is not good enough to
 239                                  * signal breakage to downstream.
 240                                  */
 241                                 char *cp = data;
 242                                 ssize_t outsz = 0;
 243                                 if (0 <= buffered) {
 244                                         *cp++ = buffered;
 245                                         outsz++;
 246                                 }
 247                                 sz = read(pu_pipe[0], cp,
 248                                           sizeof(data) - outsz);
 249                                 if (0 < sz)
 250                                                 ;
 251                                 else if (sz == 0) {
 252                                         close(pu_pipe[0]);
 253                                         pu_pipe[0] = -1;
 254                                 }
 255                                 else
 256                                         goto fail;
 257                                 sz += outsz;
 258                                 if (1 < sz) {
 259                                         buffered = data[sz-1] & 0xFF;
 260                                         sz--;
 261                                 }
 262                                 else
 263                                         buffered = -1;
 264                                 sz = send_client_data(1, data, sz);
 265                                 if (sz < 0)
 266                                         goto fail;
 267                         }
 268                         if (0 <= pe && (pfd[pe].revents & (POLLIN|POLLHUP))) {
 269                                 /* Status ready; we ship that in the side-band
 270                                  * or dump to the standard error.
 271                                  */
 272                                 sz = read(pe_pipe[0], progress,
 273                                           sizeof(progress));
 274                                 if (0 < sz)
 275                                         send_client_data(2, progress, sz);
 276                                 else if (sz == 0) {
 277                                         close(pe_pipe[0]);
 278                                         pe_pipe[0] = -1;
 279                                 }
 280                                 else
 281                                         goto fail;
 282                         }
 283                 }
 284
 285                 /* See if the children are still there */
 286                 if (pid_rev_list || pid_pack_objects) {
 287                         pid = waitpid(-1, &status, WNOHANG);
 288                         if (!pid)
 289                                 continue;
 290                         who = ((pid == pid_rev_list) ? "git-rev-list" :
 291                                (pid == pid_pack_objects) ? "git-pack-objects" :
 292                                NULL);
 293                         if (!who) {
 294                                 if (pid < 0) {
 295                                         error("git-upload-pack: %s",
 296                                               strerror(errno));
 297                                         goto fail;
 298                                 }
 299                                 error("git-upload-pack: we weren't "
 300                                       "waiting for %d", pid);
 301                                 continue;
 302                         }
 303                         if (!WIFEXITED(status) || WEXITSTATUS(status) > 0) {
 304                                 error("git-upload-pack: %s died with error.",
 305                                       who);
 306                                 goto fail;
 307                         }
 308                         if (pid == pid_rev_list)
 309                                 pid_rev_list = 0;
 310                         if (pid == pid_pack_objects)
 311                                 pid_pack_objects = 0;
 312                         if (pid_rev_list || pid_pack_objects)
 313                                 continue;
 314                 }
 315
 316                 /* both died happily */
 317                 if (pollsize)
 318                         continue;
 319
 320                 /* flush the data */
 321                 if (0 <= buffered) {
 322                         data[0] = buffered;
 323                         sz = send_client_data(1, data, 1);
 324                         if (sz < 0)
 325                                 goto fail;
 326                         fprintf(stderr, "flushed.\n");
 327                 }
 328                 if (use_sideband)
 329                         packet_flush(1);
 330                 return;
 331         }
 332  fail:
 333         if (pid_pack_objects)
 334                 kill(pid_pack_objects, SIGKILL);
 335         if (pid_rev_list)
 336                 kill(pid_rev_list, SIGKILL);
 337         send_client_data(3, abort_msg, sizeof(abort_msg));
 338         die("git-upload-pack: %s", abort_msg);
 339 }
 340
 341 static int got_sha1(char *hex, unsigned char *sha1)
 342 {
 343         struct object *o;
 344         int we_knew_they_have = 0;
 345
 346         if (get_sha1_hex(hex, sha1))
 347                 die("git-upload-pack: expected SHA1 object, got '%s'", hex);
 348         if (!has_sha1_file(sha1))
 349                 return -1;
 350
 351         o = lookup_object(sha1);
 352         if (!(o && o->parsed))
 353                 o = parse_object(sha1);
 354         if (!o)
 355                 die("oops (%s)", sha1_to_hex(sha1));
 356         if (o->type == OBJ_COMMIT) {
 357                 struct commit_list *parents;
 358                 struct commit *commit = (struct commit *)o;
 359                 if (o->flags & THEY_HAVE)
 360                         we_knew_they_have = 1;
 361                 else
 362                         o->flags |= THEY_HAVE;
 363                 if (!oldest_have || (commit->date < oldest_have))
 364                         oldest_have = commit->date;
 365                 for (parents = commit->parents;
 366                      parents;
 367                      parents = parents->next)
 368                         parents->item->object.flags |= THEY_HAVE;
 369         }
 370         if (!we_knew_they_have) {
 371                 add_object_array(o, NULL, &have_obj);
 372                 return 1;
 373         }
 374         return 0;
 375 }
 376
 377 static int reachable(struct commit *want)
 378 {
 379         struct commit_list *work = NULL;
 380
 381         insert_by_date(want, &work);
 382         while (work) {
 383                 struct commit_list *list = work->next;
 384                 struct commit *commit = work->item;
 385                 free(work);
 386                 work = list;
 387
 388                 if (commit->object.flags & THEY_HAVE) {
 389                         want->object.flags |= COMMON_KNOWN;
 390                         break;
 391                 }
 392                 if (!commit->object.parsed)
 393                         parse_object(commit->object.sha1);
 394                 if (commit->object.flags & REACHABLE)
 395                         continue;
 396                 commit->object.flags |= REACHABLE;
 397                 if (commit->date < oldest_have)
 398                         continue;
 399                 for (list = commit->parents; list; list = list->next) {
 400                         struct commit *parent = list->item;
 401                         if (!(parent->object.flags & REACHABLE))
 402                                 insert_by_date(parent, &work);
 403                 }
 404         }
 405         want->object.flags |= REACHABLE;
 406         clear_commit_marks(want, REACHABLE);
 407         free_commit_list(work);
 408         return (want->object.flags & COMMON_KNOWN);
 409 }
 410
 411 static int ok_to_give_up(void)
 412 {
 413         int i;
 414
 415         if (!have_obj.nr)
 416                 return 0;
 417
 418         for (i = 0; i < want_obj.nr; i++) {
 419                 struct object *want = want_obj.objects[i].item;
 420
 421                 if (want->flags & COMMON_KNOWN)
 422                         continue;
 423                 want = deref_tag(want, "a want line", 0);
 424                 if (!want || want->type != OBJ_COMMIT) {
 425                         /* no way to tell if this is reachable by
 426                          * looking at the ancestry chain alone, so
 427                          * leave a note to ourselves not to worry about
 428                          * this object anymore.
 429                          */
 430                         want_obj.objects[i].item->flags |= COMMON_KNOWN;
 431                         continue;
 432                 }
 433                 if (!reachable((struct commit *)want))
 434                         return 0;
 435         }
 436         return 1;
 437 }
 438
 439 static int get_common_commits(void)
 440 {
 441         static char line[1000];
 442         unsigned char sha1[20];
 443         char hex[41], last_hex[41];
 444         int len;
 445
 446         track_object_refs = 0;
 447         save_commit_buffer = 0;
 448
 449         for(;;) {
 450                 len = packet_read_line(0, line, sizeof(line));
 451                 reset_timeout();
 452
 453                 if (!len) {
 454                         if (have_obj.nr == 0 || multi_ack)
 455                                 packet_write(1, "NAK\n");
 456                         continue;
 457                 }
 458                 len = strip(line, len);
 459                 if (!strncmp(line, "have ", 5)) {
 460                         switch (got_sha1(line+5, sha1)) {
 461                         case -1: /* they have what we do not */
 462                                 if (multi_ack && ok_to_give_up())
 463                                         packet_write(1, "ACK %s continue\n",
 464                                                      sha1_to_hex(sha1));
 465                                 break;
 466                         default:
 467                                 memcpy(hex, sha1_to_hex(sha1), 41);
 468                                 if (multi_ack) {
 469                                         const char *msg = "ACK %s continue\n";
 470                                         packet_write(1, msg, hex);
 471                                         memcpy(last_hex, hex, 41);
 472                                 }
 473                                 else if (have_obj.nr == 1)
 474                                         packet_write(1, "ACK %s\n", hex);
 475                                 break;
 476                         }
 477                         continue;
 478                 }
 479                 if (!strcmp(line, "done")) {
 480                         if (have_obj.nr > 0) {
 481                                 if (multi_ack)
 482                                         packet_write(1, "ACK %s\n", last_hex);
 483                                 return 0;
 484                         }
 485                         packet_write(1, "NAK\n");
 486                         return -1;
 487                 }
 488                 die("git-upload-pack: expected SHA1 list, got '%s'", line);
 489         }
 490 }
 491
 492 static void receive_needs(void)
 493 {
 494         struct object_array shallows = {0, 0, NULL};
 495         static char line[1000];
 496         int len, depth = 0;
 497
 498         for (;;) {
 499                 struct object *o;
 500                 unsigned char sha1_buf[20];
 501                 len = packet_read_line(0, line, sizeof(line));
 502                 reset_timeout();
 503                 if (!len)
 504                         break;
 505
 506                 if (!strncmp("shallow ", line, 8)) {
 507                         unsigned char sha1[20];
 508                         struct object *object;
 509                         use_thin_pack = 0;
 510                         if (get_sha1(line + 8, sha1))
 511                                 die("invalid shallow line: %s", line);
 512                         object = parse_object(sha1);
 513                         if (!object)
 514                                 die("did not find object for %s", line);
 515                         object->flags |= CLIENT_SHALLOW;
 516                         add_object_array(object, NULL, &shallows);
 517                         continue;
 518                 }
 519                 if (!strncmp("deepen ", line, 7)) {
 520                         char *end;
 521                         use_thin_pack = 0;
 522                         depth = strtol(line + 7, &end, 0);
 523                         if (end == line + 7 || depth <= 0)
 524                                 die("Invalid deepen: %s", line);
 525                         continue;
 526                 }
 527                 if (strncmp("want ", line, 5) ||
 528                     get_sha1_hex(line+5, sha1_buf))
 529                         die("git-upload-pack: protocol error, "
 530                             "expected to get sha, not '%s'", line);
 531                 if (strstr(line+45, "multi_ack"))
 532                         multi_ack = 1;
 533                 if (strstr(line+45, "thin-pack"))
 534                         use_thin_pack = 1;
 535                 if (strstr(line+45, "ofs-delta"))
 536                         use_ofs_delta = 1;
 537                 if (strstr(line+45, "side-band-64k"))
 538                         use_sideband = LARGE_PACKET_MAX;
 539                 else if (strstr(line+45, "side-band"))
 540                         use_sideband = DEFAULT_PACKET_MAX;
 541
 542                 /* We have sent all our refs already, and the other end
 543                  * should have chosen out of them; otherwise they are
 544                  * asking for nonsense.
 545                  *
 546                  * Hmph.  We may later want to allow "want" line that
 547                  * asks for something like "master~10" (symbolic)...
 548                  * would it make sense?  I don't know.
 549                  */
 550                 o = lookup_object(sha1_buf);
 551                 if (!o || !(o->flags & OUR_REF))
 552                         die("git-upload-pack: not our ref %s", line+5);
 553                 if (!(o->flags & WANTED)) {
 554                         o->flags |= WANTED;
 555                         add_object_array(o, NULL, &want_obj);
 556                 }
 557         }
 558         if (depth == 0 && shallows.nr == 0)
 559                 return;
 560         if (depth > 0) {
 561                 struct commit_list *result, *backup;
 562                 int i;
 563                 backup = result = get_shallow_commits(&want_obj, depth,
 564                         SHALLOW, NOT_SHALLOW);
 565                 while (result) {
 566                         struct object *object = &result->item->object;
 567                         if (!(object->flags & CLIENT_SHALLOW)) {
 568                                 packet_write(1, "shallow %s",
 569                                                 sha1_to_hex(object->sha1));
 570                                 register_shallow(object->sha1);
 571                         }
 572                         result = result->next;
 573                 }
 574                 free_commit_list(backup);
 575                 for (i = 0; i < shallows.nr; i++) {
 576                         struct object *object = shallows.objects[i].item;
 577                         if (object->flags & NOT_SHALLOW) {
 578                                 struct commit_list *parents;
 579                                 packet_write(1, "unshallow %s",
 580                                         sha1_to_hex(object->sha1));
 581                                 object->flags &= ~CLIENT_SHALLOW;
 582                                 /* make sure the real parents are parsed */
 583                                 unregister_shallow(object->sha1);
 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";
 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 (!strncmp(arg, "--timeout=", 10)) {
 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
 676         upload_pack();
 677         return 0;
 678 }