upload-pack.con commit t3404: use configured shell instead of /bin/sh (1bd38e8)
   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
  14static 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
  27static unsigned long oldest_have;
  28
  29static int multi_ack, nr_our_refs;
  30static int use_thin_pack, use_ofs_delta, no_progress;
  31static struct object_array have_obj;
  32static struct object_array want_obj;
  33static unsigned int timeout;
  34/* 0 for no sideband,
  35 * otherwise maximum packet size (up to 65520 bytes).
  36 */
  37static int use_sideband;
  38
  39static void reset_timeout(void)
  40{
  41        alarm(timeout);
  42}
  43
  44static int strip(char *line, int len)
  45{
  46        if (len && line[len-1] == '\n')
  47                line[--len] = 0;
  48        return len;
  49}
  50
  51static 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
  66static FILE *pack_pipe = NULL;
  67static 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
  79static 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
  95static void show_edge(struct commit *commit)
  96{
  97        fprintf(pack_pipe, "-%s\n", sha1_to_hex(commit->object.sha1));
  98}
  99
 100static 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        return 0;
 137}
 138
 139static void create_pack_file(void)
 140{
 141        struct async 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        ssize_t sz;
 149        const char *argv[10];
 150        int arg = 0;
 151
 152        rev_list.proc = do_rev_list;
 153        /* .data is just a boolean: any non-NULL value will do */
 154        rev_list.data = create_full_pack ? &rev_list : NULL;
 155        if (start_async(&rev_list))
 156                die("git-upload-pack: unable to fork git-rev-list");
 157
 158        argv[arg++] = "pack-objects";
 159        argv[arg++] = "--stdout";
 160        if (!no_progress)
 161                argv[arg++] = "--progress";
 162        if (use_ofs_delta)
 163                argv[arg++] = "--delta-base-offset";
 164        argv[arg++] = NULL;
 165
 166        memset(&pack_objects, 0, sizeof(pack_objects));
 167        pack_objects.in = rev_list.out; /* start_command closes it */
 168        pack_objects.out = -1;
 169        pack_objects.err = -1;
 170        pack_objects.git_cmd = 1;
 171        pack_objects.argv = argv;
 172
 173        if (start_command(&pack_objects))
 174                die("git-upload-pack: unable to fork git-pack-objects");
 175
 176        /* We read from pack_objects.err to capture stderr output for
 177         * progress bar, and pack_objects.out to capture the pack data.
 178         */
 179
 180        while (1) {
 181                struct pollfd pfd[2];
 182                int pe, pu, pollsize;
 183
 184                reset_timeout();
 185
 186                pollsize = 0;
 187                pe = pu = -1;
 188
 189                if (0 <= pack_objects.out) {
 190                        pfd[pollsize].fd = pack_objects.out;
 191                        pfd[pollsize].events = POLLIN;
 192                        pu = pollsize;
 193                        pollsize++;
 194                }
 195                if (0 <= pack_objects.err) {
 196                        pfd[pollsize].fd = pack_objects.err;
 197                        pfd[pollsize].events = POLLIN;
 198                        pe = pollsize;
 199                        pollsize++;
 200                }
 201
 202                if (!pollsize)
 203                        break;
 204
 205                if (poll(pfd, pollsize, -1) < 0) {
 206                        if (errno != EINTR) {
 207                                error("poll failed, resuming: %s",
 208                                      strerror(errno));
 209                                sleep(1);
 210                        }
 211                        continue;
 212                }
 213                if (0 <= pu && (pfd[pu].revents & (POLLIN|POLLHUP))) {
 214                        /* Data ready; we keep the last byte to ourselves
 215                         * in case we detect broken rev-list, so that we
 216                         * can leave the stream corrupted.  This is
 217                         * unfortunate -- unpack-objects would happily
 218                         * accept a valid packdata with trailing garbage,
 219                         * so appending garbage after we pass all the
 220                         * pack data is not good enough to signal
 221                         * breakage to downstream.
 222                         */
 223                        char *cp = data;
 224                        ssize_t outsz = 0;
 225                        if (0 <= buffered) {
 226                                *cp++ = buffered;
 227                                outsz++;
 228                        }
 229                        sz = xread(pack_objects.out, cp,
 230                                  sizeof(data) - outsz);
 231                        if (0 < sz)
 232                                        ;
 233                        else if (sz == 0) {
 234                                close(pack_objects.out);
 235                                pack_objects.out = -1;
 236                        }
 237                        else
 238                                goto fail;
 239                        sz += outsz;
 240                        if (1 < sz) {
 241                                buffered = data[sz-1] & 0xFF;
 242                                sz--;
 243                        }
 244                        else
 245                                buffered = -1;
 246                        sz = send_client_data(1, data, sz);
 247                        if (sz < 0)
 248                                goto fail;
 249                }
 250                if (0 <= pe && (pfd[pe].revents & (POLLIN|POLLHUP))) {
 251                        /* Status ready; we ship that in the side-band
 252                         * or dump to the standard error.
 253                         */
 254                        sz = xread(pack_objects.err, progress,
 255                                  sizeof(progress));
 256                        if (0 < sz)
 257                                send_client_data(2, progress, sz);
 258                        else if (sz == 0) {
 259                                close(pack_objects.err);
 260                                pack_objects.err = -1;
 261                        }
 262                        else
 263                                goto fail;
 264                }
 265        }
 266
 267        if (finish_command(&pack_objects)) {
 268                error("git-upload-pack: git-pack-objects died with error.");
 269                goto fail;
 270        }
 271        if (finish_async(&rev_list))
 272                goto fail;      /* error was already reported */
 273
 274        /* flush the data */
 275        if (0 <= buffered) {
 276                data[0] = buffered;
 277                sz = send_client_data(1, data, 1);
 278                if (sz < 0)
 279                        goto fail;
 280                fprintf(stderr, "flushed.\n");
 281        }
 282        if (use_sideband)
 283                packet_flush(1);
 284        return;
 285
 286 fail:
 287        send_client_data(3, abort_msg, sizeof(abort_msg));
 288        die("git-upload-pack: %s", abort_msg);
 289}
 290
 291static int got_sha1(char *hex, unsigned char *sha1)
 292{
 293        struct object *o;
 294        int we_knew_they_have = 0;
 295
 296        if (get_sha1_hex(hex, sha1))
 297                die("git-upload-pack: expected SHA1 object, got '%s'", hex);
 298        if (!has_sha1_file(sha1))
 299                return -1;
 300
 301        o = lookup_object(sha1);
 302        if (!(o && o->parsed))
 303                o = parse_object(sha1);
 304        if (!o)
 305                die("oops (%s)", sha1_to_hex(sha1));
 306        if (o->type == OBJ_COMMIT) {
 307                struct commit_list *parents;
 308                struct commit *commit = (struct commit *)o;
 309                if (o->flags & THEY_HAVE)
 310                        we_knew_they_have = 1;
 311                else
 312                        o->flags |= THEY_HAVE;
 313                if (!oldest_have || (commit->date < oldest_have))
 314                        oldest_have = commit->date;
 315                for (parents = commit->parents;
 316                     parents;
 317                     parents = parents->next)
 318                        parents->item->object.flags |= THEY_HAVE;
 319        }
 320        if (!we_knew_they_have) {
 321                add_object_array(o, NULL, &have_obj);
 322                return 1;
 323        }
 324        return 0;
 325}
 326
 327static int reachable(struct commit *want)
 328{
 329        struct commit_list *work = NULL;
 330
 331        insert_by_date(want, &work);
 332        while (work) {
 333                struct commit_list *list = work->next;
 334                struct commit *commit = work->item;
 335                free(work);
 336                work = list;
 337
 338                if (commit->object.flags & THEY_HAVE) {
 339                        want->object.flags |= COMMON_KNOWN;
 340                        break;
 341                }
 342                if (!commit->object.parsed)
 343                        parse_object(commit->object.sha1);
 344                if (commit->object.flags & REACHABLE)
 345                        continue;
 346                commit->object.flags |= REACHABLE;
 347                if (commit->date < oldest_have)
 348                        continue;
 349                for (list = commit->parents; list; list = list->next) {
 350                        struct commit *parent = list->item;
 351                        if (!(parent->object.flags & REACHABLE))
 352                                insert_by_date(parent, &work);
 353                }
 354        }
 355        want->object.flags |= REACHABLE;
 356        clear_commit_marks(want, REACHABLE);
 357        free_commit_list(work);
 358        return (want->object.flags & COMMON_KNOWN);
 359}
 360
 361static int ok_to_give_up(void)
 362{
 363        int i;
 364
 365        if (!have_obj.nr)
 366                return 0;
 367
 368        for (i = 0; i < want_obj.nr; i++) {
 369                struct object *want = want_obj.objects[i].item;
 370
 371                if (want->flags & COMMON_KNOWN)
 372                        continue;
 373                want = deref_tag(want, "a want line", 0);
 374                if (!want || want->type != OBJ_COMMIT) {
 375                        /* no way to tell if this is reachable by
 376                         * looking at the ancestry chain alone, so
 377                         * leave a note to ourselves not to worry about
 378                         * this object anymore.
 379                         */
 380                        want_obj.objects[i].item->flags |= COMMON_KNOWN;
 381                        continue;
 382                }
 383                if (!reachable((struct commit *)want))
 384                        return 0;
 385        }
 386        return 1;
 387}
 388
 389static int get_common_commits(void)
 390{
 391        static char line[1000];
 392        unsigned char sha1[20];
 393        char hex[41], last_hex[41];
 394        int len;
 395
 396        track_object_refs = 0;
 397        save_commit_buffer = 0;
 398
 399        for(;;) {
 400                len = packet_read_line(0, line, sizeof(line));
 401                reset_timeout();
 402
 403                if (!len) {
 404                        if (have_obj.nr == 0 || multi_ack)
 405                                packet_write(1, "NAK\n");
 406                        continue;
 407                }
 408                len = strip(line, len);
 409                if (!prefixcmp(line, "have ")) {
 410                        switch (got_sha1(line+5, sha1)) {
 411                        case -1: /* they have what we do not */
 412                                if (multi_ack && ok_to_give_up())
 413                                        packet_write(1, "ACK %s continue\n",
 414                                                     sha1_to_hex(sha1));
 415                                break;
 416                        default:
 417                                memcpy(hex, sha1_to_hex(sha1), 41);
 418                                if (multi_ack) {
 419                                        const char *msg = "ACK %s continue\n";
 420                                        packet_write(1, msg, hex);
 421                                        memcpy(last_hex, hex, 41);
 422                                }
 423                                else if (have_obj.nr == 1)
 424                                        packet_write(1, "ACK %s\n", hex);
 425                                break;
 426                        }
 427                        continue;
 428                }
 429                if (!strcmp(line, "done")) {
 430                        if (have_obj.nr > 0) {
 431                                if (multi_ack)
 432                                        packet_write(1, "ACK %s\n", last_hex);
 433                                return 0;
 434                        }
 435                        packet_write(1, "NAK\n");
 436                        return -1;
 437                }
 438                die("git-upload-pack: expected SHA1 list, got '%s'", line);
 439        }
 440}
 441
 442static void receive_needs(void)
 443{
 444        struct object_array shallows = {0, 0, NULL};
 445        static char line[1000];
 446        int len, depth = 0;
 447
 448        for (;;) {
 449                struct object *o;
 450                unsigned char sha1_buf[20];
 451                len = packet_read_line(0, line, sizeof(line));
 452                reset_timeout();
 453                if (!len)
 454                        break;
 455
 456                if (!prefixcmp(line, "shallow ")) {
 457                        unsigned char sha1[20];
 458                        struct object *object;
 459                        use_thin_pack = 0;
 460                        if (get_sha1(line + 8, sha1))
 461                                die("invalid shallow line: %s", line);
 462                        object = parse_object(sha1);
 463                        if (!object)
 464                                die("did not find object for %s", line);
 465                        object->flags |= CLIENT_SHALLOW;
 466                        add_object_array(object, NULL, &shallows);
 467                        continue;
 468                }
 469                if (!prefixcmp(line, "deepen ")) {
 470                        char *end;
 471                        use_thin_pack = 0;
 472                        depth = strtol(line + 7, &end, 0);
 473                        if (end == line + 7 || depth <= 0)
 474                                die("Invalid deepen: %s", line);
 475                        continue;
 476                }
 477                if (prefixcmp(line, "want ") ||
 478                    get_sha1_hex(line+5, sha1_buf))
 479                        die("git-upload-pack: protocol error, "
 480                            "expected to get sha, not '%s'", line);
 481                if (strstr(line+45, "multi_ack"))
 482                        multi_ack = 1;
 483                if (strstr(line+45, "thin-pack"))
 484                        use_thin_pack = 1;
 485                if (strstr(line+45, "ofs-delta"))
 486                        use_ofs_delta = 1;
 487                if (strstr(line+45, "side-band-64k"))
 488                        use_sideband = LARGE_PACKET_MAX;
 489                else if (strstr(line+45, "side-band"))
 490                        use_sideband = DEFAULT_PACKET_MAX;
 491                if (strstr(line+45, "no-progress"))
 492                        no_progress = 1;
 493
 494                /* We have sent all our refs already, and the other end
 495                 * should have chosen out of them; otherwise they are
 496                 * asking for nonsense.
 497                 *
 498                 * Hmph.  We may later want to allow "want" line that
 499                 * asks for something like "master~10" (symbolic)...
 500                 * would it make sense?  I don't know.
 501                 */
 502                o = lookup_object(sha1_buf);
 503                if (!o || !(o->flags & OUR_REF))
 504                        die("git-upload-pack: not our ref %s", line+5);
 505                if (!(o->flags & WANTED)) {
 506                        o->flags |= WANTED;
 507                        add_object_array(o, NULL, &want_obj);
 508                }
 509        }
 510        if (depth == 0 && shallows.nr == 0)
 511                return;
 512        if (depth > 0) {
 513                struct commit_list *result, *backup;
 514                int i;
 515                backup = result = get_shallow_commits(&want_obj, depth,
 516                        SHALLOW, NOT_SHALLOW);
 517                while (result) {
 518                        struct object *object = &result->item->object;
 519                        if (!(object->flags & (CLIENT_SHALLOW|NOT_SHALLOW))) {
 520                                packet_write(1, "shallow %s",
 521                                                sha1_to_hex(object->sha1));
 522                                register_shallow(object->sha1);
 523                        }
 524                        result = result->next;
 525                }
 526                free_commit_list(backup);
 527                for (i = 0; i < shallows.nr; i++) {
 528                        struct object *object = shallows.objects[i].item;
 529                        if (object->flags & NOT_SHALLOW) {
 530                                struct commit_list *parents;
 531                                packet_write(1, "unshallow %s",
 532                                        sha1_to_hex(object->sha1));
 533                                object->flags &= ~CLIENT_SHALLOW;
 534                                /* make sure the real parents are parsed */
 535                                unregister_shallow(object->sha1);
 536                                object->parsed = 0;
 537                                if (parse_commit((struct commit *)object))
 538                                        die("invalid commit");
 539                                parents = ((struct commit *)object)->parents;
 540                                while (parents) {
 541                                        add_object_array(&parents->item->object,
 542                                                        NULL, &want_obj);
 543                                        parents = parents->next;
 544                                }
 545                        }
 546                        /* make sure commit traversal conforms to client */
 547                        register_shallow(object->sha1);
 548                }
 549                packet_flush(1);
 550        } else
 551                if (shallows.nr > 0) {
 552                        int i;
 553                        for (i = 0; i < shallows.nr; i++)
 554                                register_shallow(shallows.objects[i].item->sha1);
 555                }
 556        free(shallows.objects);
 557}
 558
 559static int send_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 560{
 561        static const char *capabilities = "multi_ack thin-pack side-band"
 562                " side-band-64k ofs-delta shallow no-progress";
 563        struct object *o = parse_object(sha1);
 564
 565        if (!o)
 566                die("git-upload-pack: cannot find object %s:", sha1_to_hex(sha1));
 567
 568        if (capabilities)
 569                packet_write(1, "%s %s%c%s\n", sha1_to_hex(sha1), refname,
 570                        0, capabilities);
 571        else
 572                packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
 573        capabilities = NULL;
 574        if (!(o->flags & OUR_REF)) {
 575                o->flags |= OUR_REF;
 576                nr_our_refs++;
 577        }
 578        if (o->type == OBJ_TAG) {
 579                o = deref_tag(o, refname, 0);
 580                if (o)
 581                        packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
 582        }
 583        return 0;
 584}
 585
 586static void upload_pack(void)
 587{
 588        reset_timeout();
 589        head_ref(send_ref, NULL);
 590        for_each_ref(send_ref, NULL);
 591        packet_flush(1);
 592        receive_needs();
 593        if (want_obj.nr) {
 594                get_common_commits();
 595                create_pack_file();
 596        }
 597}
 598
 599int main(int argc, char **argv)
 600{
 601        char *dir;
 602        int i;
 603        int strict = 0;
 604
 605        for (i = 1; i < argc; i++) {
 606                char *arg = argv[i];
 607
 608                if (arg[0] != '-')
 609                        break;
 610                if (!strcmp(arg, "--strict")) {
 611                        strict = 1;
 612                        continue;
 613                }
 614                if (!prefixcmp(arg, "--timeout=")) {
 615                        timeout = atoi(arg+10);
 616                        continue;
 617                }
 618                if (!strcmp(arg, "--")) {
 619                        i++;
 620                        break;
 621                }
 622        }
 623
 624        if (i != argc-1)
 625                usage(upload_pack_usage);
 626
 627        setup_path(NULL);
 628
 629        dir = argv[i];
 630
 631        if (!enter_repo(dir, strict))
 632                die("'%s': unable to chdir or not a git archive", dir);
 633        if (is_repository_shallow())
 634                die("attempt to fetch/clone from a shallow repository");
 635        upload_pack();
 636        return 0;
 637}