upload-pack.con commit Teach git-remote to list pushed branches. (8bf0e3d)
   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
  13static const char upload_pack_usage[] = "git-upload-pack [--strict] [--timeout=nn] <dir>";
  14
  15/* bits #0..7 in revision.h, #8..10 in commit.c */
  16#define THEY_HAVE       (1u << 11)
  17#define OUR_REF         (1u << 12)
  18#define WANTED          (1u << 13)
  19#define COMMON_KNOWN    (1u << 14)
  20#define REACHABLE       (1u << 15)
  21
  22#define SHALLOW         (1u << 16)
  23#define NOT_SHALLOW     (1u << 17)
  24#define CLIENT_SHALLOW  (1u << 18)
  25
  26static unsigned long oldest_have;
  27
  28static int multi_ack, nr_our_refs;
  29static int use_thin_pack, use_ofs_delta, no_progress;
  30static struct object_array have_obj;
  31static struct object_array want_obj;
  32static unsigned int timeout;
  33/* 0 for no sideband,
  34 * otherwise maximum packet size (up to 65520 bytes).
  35 */
  36static int use_sideband;
  37
  38static void reset_timeout(void)
  39{
  40        alarm(timeout);
  41}
  42
  43static int strip(char *line, int len)
  44{
  45        if (len && line[len-1] == '\n')
  46                line[--len] = 0;
  47        return len;
  48}
  49
  50static ssize_t send_client_data(int fd, const char *data, ssize_t sz)
  51{
  52        if (use_sideband)
  53                return send_sideband(1, fd, data, sz, use_sideband);
  54        if (fd == 3)
  55                /* emergency quit */
  56                fd = 2;
  57        if (fd == 2) {
  58                /* XXX: are we happy to lose stuff here? */
  59                xwrite(fd, data, sz);
  60                return sz;
  61        }
  62        return safe_write(fd, data, sz);
  63}
  64
  65FILE *pack_pipe = NULL;
  66static void show_commit(struct commit *commit)
  67{
  68        if (commit->object.flags & BOUNDARY)
  69                fputc('-', pack_pipe);
  70        if (fputs(sha1_to_hex(commit->object.sha1), pack_pipe) < 0)
  71                die("broken output pipe");
  72        fputc('\n', pack_pipe);
  73        fflush(pack_pipe);
  74        free(commit->buffer);
  75        commit->buffer = NULL;
  76}
  77
  78static void show_object(struct object_array_entry *p)
  79{
  80        /* An object with name "foo\n0000000..." can be used to
  81         * confuse downstream git-pack-objects very badly.
  82         */
  83        const char *ep = strchr(p->name, '\n');
  84        if (ep) {
  85                fprintf(pack_pipe, "%s %.*s\n", sha1_to_hex(p->item->sha1),
  86                       (int) (ep - p->name),
  87                       p->name);
  88        }
  89        else
  90                fprintf(pack_pipe, "%s %s\n",
  91                                sha1_to_hex(p->item->sha1), p->name);
  92}
  93
  94static void show_edge(struct commit *commit)
  95{
  96        fprintf(pack_pipe, "-%s\n", sha1_to_hex(commit->object.sha1));
  97}
  98
  99static void create_pack_file(void)
 100{
 101        /* Pipes between rev-list to pack-objects, pack-objects to us
 102         * and pack-objects error stream for progress bar.
 103         */
 104        int lp_pipe[2], pu_pipe[2], pe_pipe[2];
 105        pid_t pid_rev_list, pid_pack_objects;
 106        int create_full_pack = (nr_our_refs == want_obj.nr && !have_obj.nr);
 107        char data[8193], progress[128];
 108        char abort_msg[] = "aborting due to possible repository "
 109                "corruption on the remote side.";
 110        int buffered = -1;
 111
 112        if (pipe(lp_pipe) < 0)
 113                die("git-upload-pack: unable to create pipe");
 114        pid_rev_list = fork();
 115        if (pid_rev_list < 0)
 116                die("git-upload-pack: unable to fork git-rev-list");
 117
 118        if (!pid_rev_list) {
 119                int i;
 120                struct rev_info revs;
 121
 122                pack_pipe = fdopen(lp_pipe[1], "w");
 123
 124                if (create_full_pack)
 125                        use_thin_pack = 0; /* no point doing it */
 126                init_revisions(&revs, NULL);
 127                revs.tag_objects = 1;
 128                revs.tree_objects = 1;
 129                revs.blob_objects = 1;
 130                if (use_thin_pack)
 131                        revs.edge_hint = 1;
 132
 133                if (create_full_pack) {
 134                        const char *args[] = {"rev-list", "--all", NULL};
 135                        setup_revisions(2, args, &revs, NULL);
 136                } else {
 137                        for (i = 0; i < want_obj.nr; i++) {
 138                                struct object *o = want_obj.objects[i].item;
 139                                /* why??? */
 140                                o->flags &= ~UNINTERESTING;
 141                                add_pending_object(&revs, o, NULL);
 142                        }
 143                        for (i = 0; i < have_obj.nr; i++) {
 144                                struct object *o = have_obj.objects[i].item;
 145                                o->flags |= UNINTERESTING;
 146                                add_pending_object(&revs, o, NULL);
 147                        }
 148                        setup_revisions(0, NULL, &revs, NULL);
 149                }
 150                prepare_revision_walk(&revs);
 151                mark_edges_uninteresting(revs.commits, &revs, show_edge);
 152                traverse_commit_list(&revs, show_commit, show_object);
 153                exit(0);
 154        }
 155
 156        if (pipe(pu_pipe) < 0)
 157                die("git-upload-pack: unable to create pipe");
 158        if (pipe(pe_pipe) < 0)
 159                die("git-upload-pack: unable to create pipe");
 160        pid_pack_objects = fork();
 161        if (pid_pack_objects < 0) {
 162                /* daemon sets things up to ignore TERM */
 163                kill(pid_rev_list, SIGKILL);
 164                die("git-upload-pack: unable to fork git-pack-objects");
 165        }
 166        if (!pid_pack_objects) {
 167                const char *argv[10];
 168                int i = 0;
 169
 170                dup2(lp_pipe[0], 0);
 171                dup2(pu_pipe[1], 1);
 172                dup2(pe_pipe[1], 2);
 173
 174                close(lp_pipe[0]);
 175                close(lp_pipe[1]);
 176                close(pu_pipe[0]);
 177                close(pu_pipe[1]);
 178                close(pe_pipe[0]);
 179                close(pe_pipe[1]);
 180
 181                argv[i++] = "pack-objects";
 182                argv[i++] = "--stdout";
 183                if (!no_progress)
 184                        argv[i++] = "--progress";
 185                if (use_ofs_delta)
 186                        argv[i++] = "--delta-base-offset";
 187                argv[i++] = NULL;
 188
 189                execv_git_cmd(argv);
 190                kill(pid_rev_list, SIGKILL);
 191                die("git-upload-pack: unable to exec git-pack-objects");
 192        }
 193
 194        close(lp_pipe[0]);
 195        close(lp_pipe[1]);
 196
 197        /* We read from pe_pipe[0] to capture stderr output for
 198         * progress bar, and pu_pipe[0] to capture the pack data.
 199         */
 200        close(pe_pipe[1]);
 201        close(pu_pipe[1]);
 202
 203        while (1) {
 204                const char *who;
 205                struct pollfd pfd[2];
 206                pid_t pid;
 207                int status;
 208                ssize_t sz;
 209                int pe, pu, pollsize;
 210
 211                reset_timeout();
 212
 213                pollsize = 0;
 214                pe = pu = -1;
 215
 216                if (0 <= pu_pipe[0]) {
 217                        pfd[pollsize].fd = pu_pipe[0];
 218                        pfd[pollsize].events = POLLIN;
 219                        pu = pollsize;
 220                        pollsize++;
 221                }
 222                if (0 <= pe_pipe[0]) {
 223                        pfd[pollsize].fd = pe_pipe[0];
 224                        pfd[pollsize].events = POLLIN;
 225                        pe = pollsize;
 226                        pollsize++;
 227                }
 228
 229                if (pollsize) {
 230                        if (poll(pfd, pollsize, -1) < 0) {
 231                                if (errno != EINTR) {
 232                                        error("poll failed, resuming: %s",
 233                                              strerror(errno));
 234                                        sleep(1);
 235                                }
 236                                continue;
 237                        }
 238                        if (0 <= pu && (pfd[pu].revents & (POLLIN|POLLHUP))) {
 239                                /* Data ready; we keep the last byte
 240                                 * to ourselves in case we detect
 241                                 * broken rev-list, so that we can
 242                                 * leave the stream corrupted.  This
 243                                 * is unfortunate -- unpack-objects
 244                                 * would happily accept a valid pack
 245                                 * data with trailing garbage, so
 246                                 * appending garbage after we pass all
 247                                 * the pack data is not good enough to
 248                                 * signal breakage to downstream.
 249                                 */
 250                                char *cp = data;
 251                                ssize_t outsz = 0;
 252                                if (0 <= buffered) {
 253                                        *cp++ = buffered;
 254                                        outsz++;
 255                                }
 256                                sz = xread(pu_pipe[0], cp,
 257                                          sizeof(data) - outsz);
 258                                if (0 < sz)
 259                                                ;
 260                                else if (sz == 0) {
 261                                        close(pu_pipe[0]);
 262                                        pu_pipe[0] = -1;
 263                                }
 264                                else
 265                                        goto fail;
 266                                sz += outsz;
 267                                if (1 < sz) {
 268                                        buffered = data[sz-1] & 0xFF;
 269                                        sz--;
 270                                }
 271                                else
 272                                        buffered = -1;
 273                                sz = send_client_data(1, data, sz);
 274                                if (sz < 0)
 275                                        goto fail;
 276                        }
 277                        if (0 <= pe && (pfd[pe].revents & (POLLIN|POLLHUP))) {
 278                                /* Status ready; we ship that in the side-band
 279                                 * or dump to the standard error.
 280                                 */
 281                                sz = xread(pe_pipe[0], progress,
 282                                          sizeof(progress));
 283                                if (0 < sz)
 284                                        send_client_data(2, progress, sz);
 285                                else if (sz == 0) {
 286                                        close(pe_pipe[0]);
 287                                        pe_pipe[0] = -1;
 288                                }
 289                                else
 290                                        goto fail;
 291                        }
 292                }
 293
 294                /* See if the children are still there */
 295                if (pid_rev_list || pid_pack_objects) {
 296                        pid = waitpid(-1, &status, WNOHANG);
 297                        if (!pid)
 298                                continue;
 299                        who = ((pid == pid_rev_list) ? "git-rev-list" :
 300                               (pid == pid_pack_objects) ? "git-pack-objects" :
 301                               NULL);
 302                        if (!who) {
 303                                if (pid < 0) {
 304                                        error("git-upload-pack: %s",
 305                                              strerror(errno));
 306                                        goto fail;
 307                                }
 308                                error("git-upload-pack: we weren't "
 309                                      "waiting for %d", pid);
 310                                continue;
 311                        }
 312                        if (!WIFEXITED(status) || WEXITSTATUS(status) > 0) {
 313                                error("git-upload-pack: %s died with error.",
 314                                      who);
 315                                goto fail;
 316                        }
 317                        if (pid == pid_rev_list)
 318                                pid_rev_list = 0;
 319                        if (pid == pid_pack_objects)
 320                                pid_pack_objects = 0;
 321                        if (pid_rev_list || pid_pack_objects)
 322                                continue;
 323                }
 324
 325                /* both died happily */
 326                if (pollsize)
 327                        continue;
 328
 329                /* flush the data */
 330                if (0 <= buffered) {
 331                        data[0] = buffered;
 332                        sz = send_client_data(1, data, 1);
 333                        if (sz < 0)
 334                                goto fail;
 335                        fprintf(stderr, "flushed.\n");
 336                }
 337                if (use_sideband)
 338                        packet_flush(1);
 339                return;
 340        }
 341 fail:
 342        if (pid_pack_objects)
 343                kill(pid_pack_objects, SIGKILL);
 344        if (pid_rev_list)
 345                kill(pid_rev_list, SIGKILL);
 346        send_client_data(3, abort_msg, sizeof(abort_msg));
 347        die("git-upload-pack: %s", abort_msg);
 348}
 349
 350static int got_sha1(char *hex, unsigned char *sha1)
 351{
 352        struct object *o;
 353        int we_knew_they_have = 0;
 354
 355        if (get_sha1_hex(hex, sha1))
 356                die("git-upload-pack: expected SHA1 object, got '%s'", hex);
 357        if (!has_sha1_file(sha1))
 358                return -1;
 359
 360        o = lookup_object(sha1);
 361        if (!(o && o->parsed))
 362                o = parse_object(sha1);
 363        if (!o)
 364                die("oops (%s)", sha1_to_hex(sha1));
 365        if (o->type == OBJ_COMMIT) {
 366                struct commit_list *parents;
 367                struct commit *commit = (struct commit *)o;
 368                if (o->flags & THEY_HAVE)
 369                        we_knew_they_have = 1;
 370                else
 371                        o->flags |= THEY_HAVE;
 372                if (!oldest_have || (commit->date < oldest_have))
 373                        oldest_have = commit->date;
 374                for (parents = commit->parents;
 375                     parents;
 376                     parents = parents->next)
 377                        parents->item->object.flags |= THEY_HAVE;
 378        }
 379        if (!we_knew_they_have) {
 380                add_object_array(o, NULL, &have_obj);
 381                return 1;
 382        }
 383        return 0;
 384}
 385
 386static int reachable(struct commit *want)
 387{
 388        struct commit_list *work = NULL;
 389
 390        insert_by_date(want, &work);
 391        while (work) {
 392                struct commit_list *list = work->next;
 393                struct commit *commit = work->item;
 394                free(work);
 395                work = list;
 396
 397                if (commit->object.flags & THEY_HAVE) {
 398                        want->object.flags |= COMMON_KNOWN;
 399                        break;
 400                }
 401                if (!commit->object.parsed)
 402                        parse_object(commit->object.sha1);
 403                if (commit->object.flags & REACHABLE)
 404                        continue;
 405                commit->object.flags |= REACHABLE;
 406                if (commit->date < oldest_have)
 407                        continue;
 408                for (list = commit->parents; list; list = list->next) {
 409                        struct commit *parent = list->item;
 410                        if (!(parent->object.flags & REACHABLE))
 411                                insert_by_date(parent, &work);
 412                }
 413        }
 414        want->object.flags |= REACHABLE;
 415        clear_commit_marks(want, REACHABLE);
 416        free_commit_list(work);
 417        return (want->object.flags & COMMON_KNOWN);
 418}
 419
 420static int ok_to_give_up(void)
 421{
 422        int i;
 423
 424        if (!have_obj.nr)
 425                return 0;
 426
 427        for (i = 0; i < want_obj.nr; i++) {
 428                struct object *want = want_obj.objects[i].item;
 429
 430                if (want->flags & COMMON_KNOWN)
 431                        continue;
 432                want = deref_tag(want, "a want line", 0);
 433                if (!want || want->type != OBJ_COMMIT) {
 434                        /* no way to tell if this is reachable by
 435                         * looking at the ancestry chain alone, so
 436                         * leave a note to ourselves not to worry about
 437                         * this object anymore.
 438                         */
 439                        want_obj.objects[i].item->flags |= COMMON_KNOWN;
 440                        continue;
 441                }
 442                if (!reachable((struct commit *)want))
 443                        return 0;
 444        }
 445        return 1;
 446}
 447
 448static int get_common_commits(void)
 449{
 450        static char line[1000];
 451        unsigned char sha1[20];
 452        char hex[41], last_hex[41];
 453        int len;
 454
 455        track_object_refs = 0;
 456        save_commit_buffer = 0;
 457
 458        for(;;) {
 459                len = packet_read_line(0, line, sizeof(line));
 460                reset_timeout();
 461
 462                if (!len) {
 463                        if (have_obj.nr == 0 || multi_ack)
 464                                packet_write(1, "NAK\n");
 465                        continue;
 466                }
 467                len = strip(line, len);
 468                if (!prefixcmp(line, "have ")) {
 469                        switch (got_sha1(line+5, sha1)) {
 470                        case -1: /* they have what we do not */
 471                                if (multi_ack && ok_to_give_up())
 472                                        packet_write(1, "ACK %s continue\n",
 473                                                     sha1_to_hex(sha1));
 474                                break;
 475                        default:
 476                                memcpy(hex, sha1_to_hex(sha1), 41);
 477                                if (multi_ack) {
 478                                        const char *msg = "ACK %s continue\n";
 479                                        packet_write(1, msg, hex);
 480                                        memcpy(last_hex, hex, 41);
 481                                }
 482                                else if (have_obj.nr == 1)
 483                                        packet_write(1, "ACK %s\n", hex);
 484                                break;
 485                        }
 486                        continue;
 487                }
 488                if (!strcmp(line, "done")) {
 489                        if (have_obj.nr > 0) {
 490                                if (multi_ack)
 491                                        packet_write(1, "ACK %s\n", last_hex);
 492                                return 0;
 493                        }
 494                        packet_write(1, "NAK\n");
 495                        return -1;
 496                }
 497                die("git-upload-pack: expected SHA1 list, got '%s'", line);
 498        }
 499}
 500
 501static void receive_needs(void)
 502{
 503        struct object_array shallows = {0, 0, NULL};
 504        static char line[1000];
 505        int len, depth = 0;
 506
 507        for (;;) {
 508                struct object *o;
 509                unsigned char sha1_buf[20];
 510                len = packet_read_line(0, line, sizeof(line));
 511                reset_timeout();
 512                if (!len)
 513                        break;
 514
 515                if (!prefixcmp(line, "shallow ")) {
 516                        unsigned char sha1[20];
 517                        struct object *object;
 518                        use_thin_pack = 0;
 519                        if (get_sha1(line + 8, sha1))
 520                                die("invalid shallow line: %s", line);
 521                        object = parse_object(sha1);
 522                        if (!object)
 523                                die("did not find object for %s", line);
 524                        object->flags |= CLIENT_SHALLOW;
 525                        add_object_array(object, NULL, &shallows);
 526                        continue;
 527                }
 528                if (!prefixcmp(line, "deepen ")) {
 529                        char *end;
 530                        use_thin_pack = 0;
 531                        depth = strtol(line + 7, &end, 0);
 532                        if (end == line + 7 || depth <= 0)
 533                                die("Invalid deepen: %s", line);
 534                        continue;
 535                }
 536                if (prefixcmp(line, "want ") ||
 537                    get_sha1_hex(line+5, sha1_buf))
 538                        die("git-upload-pack: protocol error, "
 539                            "expected to get sha, not '%s'", line);
 540                if (strstr(line+45, "multi_ack"))
 541                        multi_ack = 1;
 542                if (strstr(line+45, "thin-pack"))
 543                        use_thin_pack = 1;
 544                if (strstr(line+45, "ofs-delta"))
 545                        use_ofs_delta = 1;
 546                if (strstr(line+45, "side-band-64k"))
 547                        use_sideband = LARGE_PACKET_MAX;
 548                else if (strstr(line+45, "side-band"))
 549                        use_sideband = DEFAULT_PACKET_MAX;
 550                if (strstr(line+45, "no-progress"))
 551                        no_progress = 1;
 552
 553                /* We have sent all our refs already, and the other end
 554                 * should have chosen out of them; otherwise they are
 555                 * asking for nonsense.
 556                 *
 557                 * Hmph.  We may later want to allow "want" line that
 558                 * asks for something like "master~10" (symbolic)...
 559                 * would it make sense?  I don't know.
 560                 */
 561                o = lookup_object(sha1_buf);
 562                if (!o || !(o->flags & OUR_REF))
 563                        die("git-upload-pack: not our ref %s", line+5);
 564                if (!(o->flags & WANTED)) {
 565                        o->flags |= WANTED;
 566                        add_object_array(o, NULL, &want_obj);
 567                }
 568        }
 569        if (depth == 0 && shallows.nr == 0)
 570                return;
 571        if (depth > 0) {
 572                struct commit_list *result, *backup;
 573                int i;
 574                backup = result = get_shallow_commits(&want_obj, depth,
 575                        SHALLOW, NOT_SHALLOW);
 576                while (result) {
 577                        struct object *object = &result->item->object;
 578                        if (!(object->flags & (CLIENT_SHALLOW|NOT_SHALLOW))) {
 579                                packet_write(1, "shallow %s",
 580                                                sha1_to_hex(object->sha1));
 581                                register_shallow(object->sha1);
 582                        }
 583                        result = result->next;
 584                }
 585                free_commit_list(backup);
 586                for (i = 0; i < shallows.nr; i++) {
 587                        struct object *object = shallows.objects[i].item;
 588                        if (object->flags & NOT_SHALLOW) {
 589                                struct commit_list *parents;
 590                                packet_write(1, "unshallow %s",
 591                                        sha1_to_hex(object->sha1));
 592                                object->flags &= ~CLIENT_SHALLOW;
 593                                /* make sure the real parents are parsed */
 594                                unregister_shallow(object->sha1);
 595                                object->parsed = 0;
 596                                parse_commit((struct commit *)object);
 597                                parents = ((struct commit *)object)->parents;
 598                                while (parents) {
 599                                        add_object_array(&parents->item->object,
 600                                                        NULL, &want_obj);
 601                                        parents = parents->next;
 602                                }
 603                        }
 604                        /* make sure commit traversal conforms to client */
 605                        register_shallow(object->sha1);
 606                }
 607                packet_flush(1);
 608        } else
 609                if (shallows.nr > 0) {
 610                        int i;
 611                        for (i = 0; i < shallows.nr; i++)
 612                                register_shallow(shallows.objects[i].item->sha1);
 613                }
 614        free(shallows.objects);
 615}
 616
 617static int send_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 618{
 619        static const char *capabilities = "multi_ack thin-pack side-band"
 620                " side-band-64k ofs-delta shallow no-progress";
 621        struct object *o = parse_object(sha1);
 622
 623        if (!o)
 624                die("git-upload-pack: cannot find object %s:", sha1_to_hex(sha1));
 625
 626        if (capabilities)
 627                packet_write(1, "%s %s%c%s\n", sha1_to_hex(sha1), refname,
 628                        0, capabilities);
 629        else
 630                packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
 631        capabilities = NULL;
 632        if (!(o->flags & OUR_REF)) {
 633                o->flags |= OUR_REF;
 634                nr_our_refs++;
 635        }
 636        if (o->type == OBJ_TAG) {
 637                o = deref_tag(o, refname, 0);
 638                packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
 639        }
 640        return 0;
 641}
 642
 643static void upload_pack(void)
 644{
 645        reset_timeout();
 646        head_ref(send_ref, NULL);
 647        for_each_ref(send_ref, NULL);
 648        packet_flush(1);
 649        receive_needs();
 650        if (want_obj.nr) {
 651                get_common_commits();
 652                create_pack_file();
 653        }
 654}
 655
 656int main(int argc, char **argv)
 657{
 658        char *dir;
 659        int i;
 660        int strict = 0;
 661
 662        for (i = 1; i < argc; i++) {
 663                char *arg = argv[i];
 664
 665                if (arg[0] != '-')
 666                        break;
 667                if (!strcmp(arg, "--strict")) {
 668                        strict = 1;
 669                        continue;
 670                }
 671                if (!prefixcmp(arg, "--timeout=")) {
 672                        timeout = atoi(arg+10);
 673                        continue;
 674                }
 675                if (!strcmp(arg, "--")) {
 676                        i++;
 677                        break;
 678                }
 679        }
 680        
 681        if (i != argc-1)
 682                usage(upload_pack_usage);
 683        dir = argv[i];
 684
 685        if (!enter_repo(dir, strict))
 686                die("'%s': unable to chdir or not a git archive", dir);
 687        if (is_repository_shallow())
 688                die("attempt to fetch/clone from a shallow repository");
 689        upload_pack();
 690        return 0;
 691}