upload-pack.con commit short i/o: fix calls to write to use xwrite or write_in_full (93822c2)
   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;
  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                dup2(lp_pipe[0], 0);
 168                dup2(pu_pipe[1], 1);
 169                dup2(pe_pipe[1], 2);
 170
 171                close(lp_pipe[0]);
 172                close(lp_pipe[1]);
 173                close(pu_pipe[0]);
 174                close(pu_pipe[1]);
 175                close(pe_pipe[0]);
 176                close(pe_pipe[1]);
 177                execl_git_cmd("pack-objects", "--stdout", "--progress",
 178                              use_ofs_delta ? "--delta-base-offset" : NULL,
 179                              NULL);
 180                kill(pid_rev_list, SIGKILL);
 181                die("git-upload-pack: unable to exec git-pack-objects");
 182        }
 183
 184        close(lp_pipe[0]);
 185        close(lp_pipe[1]);
 186
 187        /* We read from pe_pipe[0] to capture stderr output for
 188         * progress bar, and pu_pipe[0] to capture the pack data.
 189         */
 190        close(pe_pipe[1]);
 191        close(pu_pipe[1]);
 192
 193        while (1) {
 194                const char *who;
 195                struct pollfd pfd[2];
 196                pid_t pid;
 197                int status;
 198                ssize_t sz;
 199                int pe, pu, pollsize;
 200
 201                reset_timeout();
 202
 203                pollsize = 0;
 204                pe = pu = -1;
 205
 206                if (0 <= pu_pipe[0]) {
 207                        pfd[pollsize].fd = pu_pipe[0];
 208                        pfd[pollsize].events = POLLIN;
 209                        pu = pollsize;
 210                        pollsize++;
 211                }
 212                if (0 <= pe_pipe[0]) {
 213                        pfd[pollsize].fd = pe_pipe[0];
 214                        pfd[pollsize].events = POLLIN;
 215                        pe = pollsize;
 216                        pollsize++;
 217                }
 218
 219                if (pollsize) {
 220                        if (poll(pfd, pollsize, -1) < 0) {
 221                                if (errno != EINTR) {
 222                                        error("poll failed, resuming: %s",
 223                                              strerror(errno));
 224                                        sleep(1);
 225                                }
 226                                continue;
 227                        }
 228                        if (0 <= pu && (pfd[pu].revents & (POLLIN|POLLHUP))) {
 229                                /* Data ready; we keep the last byte
 230                                 * to ourselves in case we detect
 231                                 * broken rev-list, so that we can
 232                                 * leave the stream corrupted.  This
 233                                 * is unfortunate -- unpack-objects
 234                                 * would happily accept a valid pack
 235                                 * data with trailing garbage, so
 236                                 * appending garbage after we pass all
 237                                 * the pack data is not good enough to
 238                                 * signal breakage to downstream.
 239                                 */
 240                                char *cp = data;
 241                                ssize_t outsz = 0;
 242                                if (0 <= buffered) {
 243                                        *cp++ = buffered;
 244                                        outsz++;
 245                                }
 246                                sz = xread(pu_pipe[0], cp,
 247                                          sizeof(data) - outsz);
 248                                if (0 < sz)
 249                                                ;
 250                                else if (sz == 0) {
 251                                        close(pu_pipe[0]);
 252                                        pu_pipe[0] = -1;
 253                                }
 254                                else
 255                                        goto fail;
 256                                sz += outsz;
 257                                if (1 < sz) {
 258                                        buffered = data[sz-1] & 0xFF;
 259                                        sz--;
 260                                }
 261                                else
 262                                        buffered = -1;
 263                                sz = send_client_data(1, data, sz);
 264                                if (sz < 0)
 265                                        goto fail;
 266                        }
 267                        if (0 <= pe && (pfd[pe].revents & (POLLIN|POLLHUP))) {
 268                                /* Status ready; we ship that in the side-band
 269                                 * or dump to the standard error.
 270                                 */
 271                                sz = xread(pe_pipe[0], progress,
 272                                          sizeof(progress));
 273                                if (0 < sz)
 274                                        send_client_data(2, progress, sz);
 275                                else if (sz == 0) {
 276                                        close(pe_pipe[0]);
 277                                        pe_pipe[0] = -1;
 278                                }
 279                                else
 280                                        goto fail;
 281                        }
 282                }
 283
 284                /* See if the children are still there */
 285                if (pid_rev_list || pid_pack_objects) {
 286                        pid = waitpid(-1, &status, WNOHANG);
 287                        if (!pid)
 288                                continue;
 289                        who = ((pid == pid_rev_list) ? "git-rev-list" :
 290                               (pid == pid_pack_objects) ? "git-pack-objects" :
 291                               NULL);
 292                        if (!who) {
 293                                if (pid < 0) {
 294                                        error("git-upload-pack: %s",
 295                                              strerror(errno));
 296                                        goto fail;
 297                                }
 298                                error("git-upload-pack: we weren't "
 299                                      "waiting for %d", pid);
 300                                continue;
 301                        }
 302                        if (!WIFEXITED(status) || WEXITSTATUS(status) > 0) {
 303                                error("git-upload-pack: %s died with error.",
 304                                      who);
 305                                goto fail;
 306                        }
 307                        if (pid == pid_rev_list)
 308                                pid_rev_list = 0;
 309                        if (pid == pid_pack_objects)
 310                                pid_pack_objects = 0;
 311                        if (pid_rev_list || pid_pack_objects)
 312                                continue;
 313                }
 314
 315                /* both died happily */
 316                if (pollsize)
 317                        continue;
 318
 319                /* flush the data */
 320                if (0 <= buffered) {
 321                        data[0] = buffered;
 322                        sz = send_client_data(1, data, 1);
 323                        if (sz < 0)
 324                                goto fail;
 325                        fprintf(stderr, "flushed.\n");
 326                }
 327                if (use_sideband)
 328                        packet_flush(1);
 329                return;
 330        }
 331 fail:
 332        if (pid_pack_objects)
 333                kill(pid_pack_objects, SIGKILL);
 334        if (pid_rev_list)
 335                kill(pid_rev_list, SIGKILL);
 336        send_client_data(3, abort_msg, sizeof(abort_msg));
 337        die("git-upload-pack: %s", abort_msg);
 338}
 339
 340static int got_sha1(char *hex, unsigned char *sha1)
 341{
 342        struct object *o;
 343        int we_knew_they_have = 0;
 344
 345        if (get_sha1_hex(hex, sha1))
 346                die("git-upload-pack: expected SHA1 object, got '%s'", hex);
 347        if (!has_sha1_file(sha1))
 348                return -1;
 349
 350        o = lookup_object(sha1);
 351        if (!(o && o->parsed))
 352                o = parse_object(sha1);
 353        if (!o)
 354                die("oops (%s)", sha1_to_hex(sha1));
 355        if (o->type == OBJ_COMMIT) {
 356                struct commit_list *parents;
 357                struct commit *commit = (struct commit *)o;
 358                if (o->flags & THEY_HAVE)
 359                        we_knew_they_have = 1;
 360                else
 361                        o->flags |= THEY_HAVE;
 362                if (!oldest_have || (commit->date < oldest_have))
 363                        oldest_have = commit->date;
 364                for (parents = commit->parents;
 365                     parents;
 366                     parents = parents->next)
 367                        parents->item->object.flags |= THEY_HAVE;
 368        }
 369        if (!we_knew_they_have) {
 370                add_object_array(o, NULL, &have_obj);
 371                return 1;
 372        }
 373        return 0;
 374}
 375
 376static int reachable(struct commit *want)
 377{
 378        struct commit_list *work = NULL;
 379
 380        insert_by_date(want, &work);
 381        while (work) {
 382                struct commit_list *list = work->next;
 383                struct commit *commit = work->item;
 384                free(work);
 385                work = list;
 386
 387                if (commit->object.flags & THEY_HAVE) {
 388                        want->object.flags |= COMMON_KNOWN;
 389                        break;
 390                }
 391                if (!commit->object.parsed)
 392                        parse_object(commit->object.sha1);
 393                if (commit->object.flags & REACHABLE)
 394                        continue;
 395                commit->object.flags |= REACHABLE;
 396                if (commit->date < oldest_have)
 397                        continue;
 398                for (list = commit->parents; list; list = list->next) {
 399                        struct commit *parent = list->item;
 400                        if (!(parent->object.flags & REACHABLE))
 401                                insert_by_date(parent, &work);
 402                }
 403        }
 404        want->object.flags |= REACHABLE;
 405        clear_commit_marks(want, REACHABLE);
 406        free_commit_list(work);
 407        return (want->object.flags & COMMON_KNOWN);
 408}
 409
 410static int ok_to_give_up(void)
 411{
 412        int i;
 413
 414        if (!have_obj.nr)
 415                return 0;
 416
 417        for (i = 0; i < want_obj.nr; i++) {
 418                struct object *want = want_obj.objects[i].item;
 419
 420                if (want->flags & COMMON_KNOWN)
 421                        continue;
 422                want = deref_tag(want, "a want line", 0);
 423                if (!want || want->type != OBJ_COMMIT) {
 424                        /* no way to tell if this is reachable by
 425                         * looking at the ancestry chain alone, so
 426                         * leave a note to ourselves not to worry about
 427                         * this object anymore.
 428                         */
 429                        want_obj.objects[i].item->flags |= COMMON_KNOWN;
 430                        continue;
 431                }
 432                if (!reachable((struct commit *)want))
 433                        return 0;
 434        }
 435        return 1;
 436}
 437
 438static int get_common_commits(void)
 439{
 440        static char line[1000];
 441        unsigned char sha1[20];
 442        char hex[41], last_hex[41];
 443        int len;
 444
 445        track_object_refs = 0;
 446        save_commit_buffer = 0;
 447
 448        for(;;) {
 449                len = packet_read_line(0, line, sizeof(line));
 450                reset_timeout();
 451
 452                if (!len) {
 453                        if (have_obj.nr == 0 || multi_ack)
 454                                packet_write(1, "NAK\n");
 455                        continue;
 456                }
 457                len = strip(line, len);
 458                if (!strncmp(line, "have ", 5)) {
 459                        switch (got_sha1(line+5, sha1)) {
 460                        case -1: /* they have what we do not */
 461                                if (multi_ack && ok_to_give_up())
 462                                        packet_write(1, "ACK %s continue\n",
 463                                                     sha1_to_hex(sha1));
 464                                break;
 465                        default:
 466                                memcpy(hex, sha1_to_hex(sha1), 41);
 467                                if (multi_ack) {
 468                                        const char *msg = "ACK %s continue\n";
 469                                        packet_write(1, msg, hex);
 470                                        memcpy(last_hex, hex, 41);
 471                                }
 472                                else if (have_obj.nr == 1)
 473                                        packet_write(1, "ACK %s\n", hex);
 474                                break;
 475                        }
 476                        continue;
 477                }
 478                if (!strcmp(line, "done")) {
 479                        if (have_obj.nr > 0) {
 480                                if (multi_ack)
 481                                        packet_write(1, "ACK %s\n", last_hex);
 482                                return 0;
 483                        }
 484                        packet_write(1, "NAK\n");
 485                        return -1;
 486                }
 487                die("git-upload-pack: expected SHA1 list, got '%s'", line);
 488        }
 489}
 490
 491static void receive_needs(void)
 492{
 493        struct object_array shallows = {0, 0, NULL};
 494        static char line[1000];
 495        int len, depth = 0;
 496
 497        for (;;) {
 498                struct object *o;
 499                unsigned char sha1_buf[20];
 500                len = packet_read_line(0, line, sizeof(line));
 501                reset_timeout();
 502                if (!len)
 503                        break;
 504
 505                if (!strncmp("shallow ", line, 8)) {
 506                        unsigned char sha1[20];
 507                        struct object *object;
 508                        use_thin_pack = 0;
 509                        if (get_sha1(line + 8, sha1))
 510                                die("invalid shallow line: %s", line);
 511                        object = parse_object(sha1);
 512                        if (!object)
 513                                die("did not find object for %s", line);
 514                        object->flags |= CLIENT_SHALLOW;
 515                        add_object_array(object, NULL, &shallows);
 516                        continue;
 517                }
 518                if (!strncmp("deepen ", line, 7)) {
 519                        char *end;
 520                        use_thin_pack = 0;
 521                        depth = strtol(line + 7, &end, 0);
 522                        if (end == line + 7 || depth <= 0)
 523                                die("Invalid deepen: %s", line);
 524                        continue;
 525                }
 526                if (strncmp("want ", line, 5) ||
 527                    get_sha1_hex(line+5, sha1_buf))
 528                        die("git-upload-pack: protocol error, "
 529                            "expected to get sha, not '%s'", line);
 530                if (strstr(line+45, "multi_ack"))
 531                        multi_ack = 1;
 532                if (strstr(line+45, "thin-pack"))
 533                        use_thin_pack = 1;
 534                if (strstr(line+45, "ofs-delta"))
 535                        use_ofs_delta = 1;
 536                if (strstr(line+45, "side-band-64k"))
 537                        use_sideband = LARGE_PACKET_MAX;
 538                else if (strstr(line+45, "side-band"))
 539                        use_sideband = DEFAULT_PACKET_MAX;
 540
 541                /* We have sent all our refs already, and the other end
 542                 * should have chosen out of them; otherwise they are
 543                 * asking for nonsense.
 544                 *
 545                 * Hmph.  We may later want to allow "want" line that
 546                 * asks for something like "master~10" (symbolic)...
 547                 * would it make sense?  I don't know.
 548                 */
 549                o = lookup_object(sha1_buf);
 550                if (!o || !(o->flags & OUR_REF))
 551                        die("git-upload-pack: not our ref %s", line+5);
 552                if (!(o->flags & WANTED)) {
 553                        o->flags |= WANTED;
 554                        add_object_array(o, NULL, &want_obj);
 555                }
 556        }
 557        if (depth == 0 && shallows.nr == 0)
 558                return;
 559        if (depth > 0) {
 560                struct commit_list *result, *backup;
 561                int i;
 562                backup = result = get_shallow_commits(&want_obj, depth,
 563                        SHALLOW, NOT_SHALLOW);
 564                while (result) {
 565                        struct object *object = &result->item->object;
 566                        if (!(object->flags & (CLIENT_SHALLOW|NOT_SHALLOW))) {
 567                                packet_write(1, "shallow %s",
 568                                                sha1_to_hex(object->sha1));
 569                                register_shallow(object->sha1);
 570                        }
 571                        result = result->next;
 572                }
 573                free_commit_list(backup);
 574                for (i = 0; i < shallows.nr; i++) {
 575                        struct object *object = shallows.objects[i].item;
 576                        if (object->flags & NOT_SHALLOW) {
 577                                struct commit_list *parents;
 578                                packet_write(1, "unshallow %s",
 579                                        sha1_to_hex(object->sha1));
 580                                object->flags &= ~CLIENT_SHALLOW;
 581                                /* make sure the real parents are parsed */
 582                                unregister_shallow(object->sha1);
 583                                object->parsed = 0;
 584                                parse_commit((struct commit *)object);
 585                                parents = ((struct commit *)object)->parents;
 586                                while (parents) {
 587                                        add_object_array(&parents->item->object,
 588                                                        NULL, &want_obj);
 589                                        parents = parents->next;
 590                                }
 591                        }
 592                        /* make sure commit traversal conforms to client */
 593                        register_shallow(object->sha1);
 594                }
 595                packet_flush(1);
 596        } else
 597                if (shallows.nr > 0) {
 598                        int i;
 599                        for (i = 0; i < shallows.nr; i++)
 600                                register_shallow(shallows.objects[i].item->sha1);
 601                }
 602        free(shallows.objects);
 603}
 604
 605static 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
 631static 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
 644int 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}