Andrew's git / gitweb.git / transport-helper.c
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transport-helper.con commit unpack-trees: handle lstat failure for existing file (a93e530)
   1#include "cache.h"
   2#include "transport.h"
   3#include "quote.h"
   4#include "run-command.h"
   5#include "commit.h"
   6#include "diff.h"
   7#include "revision.h"
   8#include "quote.h"
   9#include "remote.h"
  10#include "string-list.h"
  11
  12static int debug;
  13
  14struct helper_data
  15{
  16        const char *name;
  17        struct child_process *helper;
  18        FILE *out;
  19        unsigned fetch : 1,
  20                import : 1,
  21                export : 1,
  22                option : 1,
  23                push : 1,
  24                connect : 1,
  25                no_disconnect_req : 1;
  26        /* These go from remote name (as in "list") to private name */
  27        struct refspec *refspecs;
  28        int refspec_nr;
  29        /* Transport options for fetch-pack/send-pack (should one of
  30         * those be invoked).
  31         */
  32        struct git_transport_options transport_options;
  33};
  34
  35static void sendline(struct helper_data *helper, struct strbuf *buffer)
  36{
  37        if (debug)
  38                fprintf(stderr, "Debug: Remote helper: -> %s", buffer->buf);
  39        if (write_in_full(helper->helper->in, buffer->buf, buffer->len)
  40                != buffer->len)
  41                die_errno("Full write to remote helper failed");
  42}
  43
  44static int recvline_fh(FILE *helper, struct strbuf *buffer)
  45{
  46        strbuf_reset(buffer);
  47        if (debug)
  48                fprintf(stderr, "Debug: Remote helper: Waiting...\n");
  49        if (strbuf_getline(buffer, helper, '\n') == EOF) {
  50                if (debug)
  51                        fprintf(stderr, "Debug: Remote helper quit.\n");
  52                exit(128);
  53        }
  54
  55        if (debug)
  56                fprintf(stderr, "Debug: Remote helper: <- %s\n", buffer->buf);
  57        return 0;
  58}
  59
  60static int recvline(struct helper_data *helper, struct strbuf *buffer)
  61{
  62        return recvline_fh(helper->out, buffer);
  63}
  64
  65static void xchgline(struct helper_data *helper, struct strbuf *buffer)
  66{
  67        sendline(helper, buffer);
  68        recvline(helper, buffer);
  69}
  70
  71static void write_constant(int fd, const char *str)
  72{
  73        if (debug)
  74                fprintf(stderr, "Debug: Remote helper: -> %s", str);
  75        if (write_in_full(fd, str, strlen(str)) != strlen(str))
  76                die_errno("Full write to remote helper failed");
  77}
  78
  79const char *remove_ext_force(const char *url)
  80{
  81        if (url) {
  82                const char *colon = strchr(url, ':');
  83                if (colon && colon[1] == ':')
  84                        return colon + 2;
  85        }
  86        return url;
  87}
  88
  89static void do_take_over(struct transport *transport)
  90{
  91        struct helper_data *data;
  92        data = (struct helper_data *)transport->data;
  93        transport_take_over(transport, data->helper);
  94        fclose(data->out);
  95        free(data);
  96}
  97
  98static struct child_process *get_helper(struct transport *transport)
  99{
 100        struct helper_data *data = transport->data;
 101        struct strbuf buf = STRBUF_INIT;
 102        struct child_process *helper;
 103        const char **refspecs = NULL;
 104        int refspec_nr = 0;
 105        int refspec_alloc = 0;
 106        int duped;
 107        int code;
 108
 109        if (data->helper)
 110                return data->helper;
 111
 112        helper = xcalloc(1, sizeof(*helper));
 113        helper->in = -1;
 114        helper->out = -1;
 115        helper->err = 0;
 116        helper->argv = xcalloc(4, sizeof(*helper->argv));
 117        strbuf_addf(&buf, "git-remote-%s", data->name);
 118        helper->argv[0] = strbuf_detach(&buf, NULL);
 119        helper->argv[1] = transport->remote->name;
 120        helper->argv[2] = remove_ext_force(transport->url);
 121        helper->git_cmd = 0;
 122        helper->silent_exec_failure = 1;
 123        code = start_command(helper);
 124        if (code < 0 && errno == ENOENT)
 125                die("Unable to find remote helper for '%s'", data->name);
 126        else if (code != 0)
 127                exit(code);
 128
 129        data->helper = helper;
 130        data->no_disconnect_req = 0;
 131
 132        /*
 133         * Open the output as FILE* so strbuf_getline() can be used.
 134         * Do this with duped fd because fclose() will close the fd,
 135         * and stuff like taking over will require the fd to remain.
 136         */
 137        duped = dup(helper->out);
 138        if (duped < 0)
 139                die_errno("Can't dup helper output fd");
 140        data->out = xfdopen(duped, "r");
 141
 142        write_constant(helper->in, "capabilities\n");
 143
 144        while (1) {
 145                const char *capname;
 146                int mandatory = 0;
 147                recvline(data, &buf);
 148
 149                if (!*buf.buf)
 150                        break;
 151
 152                if (*buf.buf == '*') {
 153                        capname = buf.buf + 1;
 154                        mandatory = 1;
 155                } else
 156                        capname = buf.buf;
 157
 158                if (debug)
 159                        fprintf(stderr, "Debug: Got cap %s\n", capname);
 160                if (!strcmp(capname, "fetch"))
 161                        data->fetch = 1;
 162                else if (!strcmp(capname, "option"))
 163                        data->option = 1;
 164                else if (!strcmp(capname, "push"))
 165                        data->push = 1;
 166                else if (!strcmp(capname, "import"))
 167                        data->import = 1;
 168                else if (!strcmp(capname, "export"))
 169                        data->export = 1;
 170                else if (!data->refspecs && !prefixcmp(capname, "refspec ")) {
 171                        ALLOC_GROW(refspecs,
 172                                   refspec_nr + 1,
 173                                   refspec_alloc);
 174                        refspecs[refspec_nr++] = strdup(buf.buf + strlen("refspec "));
 175                } else if (!strcmp(capname, "connect")) {
 176                        data->connect = 1;
 177                } else if (!strcmp(buf.buf, "gitdir")) {
 178                        struct strbuf gitdir = STRBUF_INIT;
 179                        strbuf_addf(&gitdir, "gitdir %s\n", get_git_dir());
 180                        sendline(data, &gitdir);
 181                        strbuf_release(&gitdir);
 182                } else if (mandatory) {
 183                        die("Unknown mandatory capability %s. This remote "
 184                            "helper probably needs newer version of Git.\n",
 185                            capname);
 186                }
 187        }
 188        if (refspecs) {
 189                int i;
 190                data->refspec_nr = refspec_nr;
 191                data->refspecs = parse_fetch_refspec(refspec_nr, refspecs);
 192                for (i = 0; i < refspec_nr; i++) {
 193                        free((char *)refspecs[i]);
 194                }
 195                free(refspecs);
 196        }
 197        strbuf_release(&buf);
 198        if (debug)
 199                fprintf(stderr, "Debug: Capabilities complete.\n");
 200        return data->helper;
 201}
 202
 203static int disconnect_helper(struct transport *transport)
 204{
 205        struct helper_data *data = transport->data;
 206        struct strbuf buf = STRBUF_INIT;
 207
 208        if (data->helper) {
 209                if (debug)
 210                        fprintf(stderr, "Debug: Disconnecting.\n");
 211                if (!data->no_disconnect_req) {
 212                        strbuf_addf(&buf, "\n");
 213                        sendline(data, &buf);
 214                }
 215                close(data->helper->in);
 216                close(data->helper->out);
 217                fclose(data->out);
 218                finish_command(data->helper);
 219                free((char *)data->helper->argv[0]);
 220                free(data->helper->argv);
 221                free(data->helper);
 222                data->helper = NULL;
 223        }
 224        return 0;
 225}
 226
 227static const char *unsupported_options[] = {
 228        TRANS_OPT_UPLOADPACK,
 229        TRANS_OPT_RECEIVEPACK,
 230        TRANS_OPT_THIN,
 231        TRANS_OPT_KEEP
 232        };
 233static const char *boolean_options[] = {
 234        TRANS_OPT_THIN,
 235        TRANS_OPT_KEEP,
 236        TRANS_OPT_FOLLOWTAGS
 237        };
 238
 239static int set_helper_option(struct transport *transport,
 240                          const char *name, const char *value)
 241{
 242        struct helper_data *data = transport->data;
 243        struct strbuf buf = STRBUF_INIT;
 244        int i, ret, is_bool = 0;
 245
 246        get_helper(transport);
 247
 248        if (!data->option)
 249                return 1;
 250
 251        for (i = 0; i < ARRAY_SIZE(unsupported_options); i++) {
 252                if (!strcmp(name, unsupported_options[i]))
 253                        return 1;
 254        }
 255
 256        for (i = 0; i < ARRAY_SIZE(boolean_options); i++) {
 257                if (!strcmp(name, boolean_options[i])) {
 258                        is_bool = 1;
 259                        break;
 260                }
 261        }
 262
 263        strbuf_addf(&buf, "option %s ", name);
 264        if (is_bool)
 265                strbuf_addstr(&buf, value ? "true" : "false");
 266        else
 267                quote_c_style(value, &buf, NULL, 0);
 268        strbuf_addch(&buf, '\n');
 269
 270        xchgline(data, &buf);
 271
 272        if (!strcmp(buf.buf, "ok"))
 273                ret = 0;
 274        else if (!prefixcmp(buf.buf, "error")) {
 275                ret = -1;
 276        } else if (!strcmp(buf.buf, "unsupported"))
 277                ret = 1;
 278        else {
 279                warning("%s unexpectedly said: '%s'", data->name, buf.buf);
 280                ret = 1;
 281        }
 282        strbuf_release(&buf);
 283        return ret;
 284}
 285
 286static void standard_options(struct transport *t)
 287{
 288        char buf[16];
 289        int n;
 290        int v = t->verbose;
 291
 292        set_helper_option(t, "progress", t->progress ? "true" : "false");
 293
 294        n = snprintf(buf, sizeof(buf), "%d", v + 1);
 295        if (n >= sizeof(buf))
 296                die("impossibly large verbosity value");
 297        set_helper_option(t, "verbosity", buf);
 298}
 299
 300static int release_helper(struct transport *transport)
 301{
 302        struct helper_data *data = transport->data;
 303        free_refspec(data->refspec_nr, data->refspecs);
 304        data->refspecs = NULL;
 305        disconnect_helper(transport);
 306        free(transport->data);
 307        return 0;
 308}
 309
 310static int fetch_with_fetch(struct transport *transport,
 311                            int nr_heads, struct ref **to_fetch)
 312{
 313        struct helper_data *data = transport->data;
 314        int i;
 315        struct strbuf buf = STRBUF_INIT;
 316
 317        standard_options(transport);
 318
 319        for (i = 0; i < nr_heads; i++) {
 320                const struct ref *posn = to_fetch[i];
 321                if (posn->status & REF_STATUS_UPTODATE)
 322                        continue;
 323
 324                strbuf_addf(&buf, "fetch %s %s\n",
 325                            sha1_to_hex(posn->old_sha1), posn->name);
 326        }
 327
 328        strbuf_addch(&buf, '\n');
 329        sendline(data, &buf);
 330
 331        while (1) {
 332                recvline(data, &buf);
 333
 334                if (!prefixcmp(buf.buf, "lock ")) {
 335                        const char *name = buf.buf + 5;
 336                        if (transport->pack_lockfile)
 337                                warning("%s also locked %s", data->name, name);
 338                        else
 339                                transport->pack_lockfile = xstrdup(name);
 340                }
 341                else if (!buf.len)
 342                        break;
 343                else
 344                        warning("%s unexpectedly said: '%s'", data->name, buf.buf);
 345        }
 346        strbuf_release(&buf);
 347        return 0;
 348}
 349
 350static int get_importer(struct transport *transport, struct child_process *fastimport)
 351{
 352        struct child_process *helper = get_helper(transport);
 353        memset(fastimport, 0, sizeof(*fastimport));
 354        fastimport->in = helper->out;
 355        fastimport->argv = xcalloc(5, sizeof(*fastimport->argv));
 356        fastimport->argv[0] = "fast-import";
 357        fastimport->argv[1] = "--quiet";
 358
 359        fastimport->git_cmd = 1;
 360        return start_command(fastimport);
 361}
 362
 363static int get_exporter(struct transport *transport,
 364                        struct child_process *fastexport,
 365                        const char *export_marks,
 366                        const char *import_marks,
 367                        struct string_list *revlist_args)
 368{
 369        struct child_process *helper = get_helper(transport);
 370        int argc = 0, i;
 371        memset(fastexport, 0, sizeof(*fastexport));
 372
 373        /* we need to duplicate helper->in because we want to use it after
 374         * fastexport is done with it. */
 375        fastexport->out = dup(helper->in);
 376        fastexport->argv = xcalloc(4 + revlist_args->nr, sizeof(*fastexport->argv));
 377        fastexport->argv[argc++] = "fast-export";
 378        if (export_marks)
 379                fastexport->argv[argc++] = export_marks;
 380        if (import_marks)
 381                fastexport->argv[argc++] = import_marks;
 382
 383        for (i = 0; i < revlist_args->nr; i++)
 384                fastexport->argv[argc++] = revlist_args->items[i].string;
 385
 386        fastexport->git_cmd = 1;
 387        return start_command(fastexport);
 388}
 389
 390static int fetch_with_import(struct transport *transport,
 391                             int nr_heads, struct ref **to_fetch)
 392{
 393        struct child_process fastimport;
 394        struct helper_data *data = transport->data;
 395        int i;
 396        struct ref *posn;
 397        struct strbuf buf = STRBUF_INIT;
 398
 399        get_helper(transport);
 400
 401        if (get_importer(transport, &fastimport))
 402                die("Couldn't run fast-import");
 403
 404        for (i = 0; i < nr_heads; i++) {
 405                posn = to_fetch[i];
 406                if (posn->status & REF_STATUS_UPTODATE)
 407                        continue;
 408
 409                strbuf_addf(&buf, "import %s\n", posn->name);
 410                sendline(data, &buf);
 411                strbuf_reset(&buf);
 412        }
 413        disconnect_helper(transport);
 414        finish_command(&fastimport);
 415        free(fastimport.argv);
 416        fastimport.argv = NULL;
 417
 418        for (i = 0; i < nr_heads; i++) {
 419                char *private;
 420                posn = to_fetch[i];
 421                if (posn->status & REF_STATUS_UPTODATE)
 422                        continue;
 423                if (data->refspecs)
 424                        private = apply_refspecs(data->refspecs, data->refspec_nr, posn->name);
 425                else
 426                        private = strdup(posn->name);
 427                read_ref(private, posn->old_sha1);
 428                free(private);
 429        }
 430        strbuf_release(&buf);
 431        return 0;
 432}
 433
 434static int process_connect_service(struct transport *transport,
 435                                   const char *name, const char *exec)
 436{
 437        struct helper_data *data = transport->data;
 438        struct strbuf cmdbuf = STRBUF_INIT;
 439        struct child_process *helper;
 440        int r, duped, ret = 0;
 441        FILE *input;
 442
 443        helper = get_helper(transport);
 444
 445        /*
 446         * Yes, dup the pipe another time, as we need unbuffered version
 447         * of input pipe as FILE*. fclose() closes the underlying fd and
 448         * stream buffering only can be changed before first I/O operation
 449         * on it.
 450         */
 451        duped = dup(helper->out);
 452        if (duped < 0)
 453                die_errno("Can't dup helper output fd");
 454        input = xfdopen(duped, "r");
 455        setvbuf(input, NULL, _IONBF, 0);
 456
 457        /*
 458         * Handle --upload-pack and friends. This is fire and forget...
 459         * just warn if it fails.
 460         */
 461        if (strcmp(name, exec)) {
 462                r = set_helper_option(transport, "servpath", exec);
 463                if (r > 0)
 464                        warning("Setting remote service path not supported by protocol.");
 465                else if (r < 0)
 466                        warning("Invalid remote service path.");
 467        }
 468
 469        if (data->connect)
 470                strbuf_addf(&cmdbuf, "connect %s\n", name);
 471        else
 472                goto exit;
 473
 474        sendline(data, &cmdbuf);
 475        recvline_fh(input, &cmdbuf);
 476        if (!strcmp(cmdbuf.buf, "")) {
 477                data->no_disconnect_req = 1;
 478                if (debug)
 479                        fprintf(stderr, "Debug: Smart transport connection "
 480                                "ready.\n");
 481                ret = 1;
 482        } else if (!strcmp(cmdbuf.buf, "fallback")) {
 483                if (debug)
 484                        fprintf(stderr, "Debug: Falling back to dumb "
 485                                "transport.\n");
 486        } else
 487                die("Unknown response to connect: %s",
 488                        cmdbuf.buf);
 489
 490exit:
 491        fclose(input);
 492        return ret;
 493}
 494
 495static int process_connect(struct transport *transport,
 496                                     int for_push)
 497{
 498        struct helper_data *data = transport->data;
 499        const char *name;
 500        const char *exec;
 501
 502        name = for_push ? "git-receive-pack" : "git-upload-pack";
 503        if (for_push)
 504                exec = data->transport_options.receivepack;
 505        else
 506                exec = data->transport_options.uploadpack;
 507
 508        return process_connect_service(transport, name, exec);
 509}
 510
 511static int connect_helper(struct transport *transport, const char *name,
 512                   const char *exec, int fd[2])
 513{
 514        struct helper_data *data = transport->data;
 515
 516        /* Get_helper so connect is inited. */
 517        get_helper(transport);
 518        if (!data->connect)
 519                die("Operation not supported by protocol.");
 520
 521        if (!process_connect_service(transport, name, exec))
 522                die("Can't connect to subservice %s.", name);
 523
 524        fd[0] = data->helper->out;
 525        fd[1] = data->helper->in;
 526        return 0;
 527}
 528
 529static int fetch(struct transport *transport,
 530                 int nr_heads, struct ref **to_fetch)
 531{
 532        struct helper_data *data = transport->data;
 533        int i, count;
 534
 535        if (process_connect(transport, 0)) {
 536                do_take_over(transport);
 537                return transport->fetch(transport, nr_heads, to_fetch);
 538        }
 539
 540        count = 0;
 541        for (i = 0; i < nr_heads; i++)
 542                if (!(to_fetch[i]->status & REF_STATUS_UPTODATE))
 543                        count++;
 544
 545        if (!count)
 546                return 0;
 547
 548        if (data->fetch)
 549                return fetch_with_fetch(transport, nr_heads, to_fetch);
 550
 551        if (data->import)
 552                return fetch_with_import(transport, nr_heads, to_fetch);
 553
 554        return -1;
 555}
 556
 557static int push_refs_with_push(struct transport *transport,
 558                struct ref *remote_refs, int flags)
 559{
 560        int force_all = flags & TRANSPORT_PUSH_FORCE;
 561        int mirror = flags & TRANSPORT_PUSH_MIRROR;
 562        struct helper_data *data = transport->data;
 563        struct strbuf buf = STRBUF_INIT;
 564        struct child_process *helper;
 565        struct ref *ref;
 566
 567        helper = get_helper(transport);
 568        if (!data->push)
 569                return 1;
 570
 571        for (ref = remote_refs; ref; ref = ref->next) {
 572                if (!ref->peer_ref && !mirror)
 573                        continue;
 574
 575                /* Check for statuses set by set_ref_status_for_push() */
 576                switch (ref->status) {
 577                case REF_STATUS_REJECT_NONFASTFORWARD:
 578                case REF_STATUS_UPTODATE:
 579                        continue;
 580                default:
 581                        ; /* do nothing */
 582                }
 583
 584                if (force_all)
 585                        ref->force = 1;
 586
 587                strbuf_addstr(&buf, "push ");
 588                if (!ref->deletion) {
 589                        if (ref->force)
 590                                strbuf_addch(&buf, '+');
 591                        if (ref->peer_ref)
 592                                strbuf_addstr(&buf, ref->peer_ref->name);
 593                        else
 594                                strbuf_addstr(&buf, sha1_to_hex(ref->new_sha1));
 595                }
 596                strbuf_addch(&buf, ':');
 597                strbuf_addstr(&buf, ref->name);
 598                strbuf_addch(&buf, '\n');
 599        }
 600        if (buf.len == 0)
 601                return 0;
 602
 603        standard_options(transport);
 604
 605        if (flags & TRANSPORT_PUSH_DRY_RUN) {
 606                if (set_helper_option(transport, "dry-run", "true") != 0)
 607                        die("helper %s does not support dry-run", data->name);
 608        }
 609
 610        strbuf_addch(&buf, '\n');
 611        sendline(data, &buf);
 612
 613        ref = remote_refs;
 614        while (1) {
 615                char *refname, *msg;
 616                int status;
 617
 618                recvline(data, &buf);
 619                if (!buf.len)
 620                        break;
 621
 622                if (!prefixcmp(buf.buf, "ok ")) {
 623                        status = REF_STATUS_OK;
 624                        refname = buf.buf + 3;
 625                } else if (!prefixcmp(buf.buf, "error ")) {
 626                        status = REF_STATUS_REMOTE_REJECT;
 627                        refname = buf.buf + 6;
 628                } else
 629                        die("expected ok/error, helper said '%s'\n", buf.buf);
 630
 631                msg = strchr(refname, ' ');
 632                if (msg) {
 633                        struct strbuf msg_buf = STRBUF_INIT;
 634                        const char *end;
 635
 636                        *msg++ = '\0';
 637                        if (!unquote_c_style(&msg_buf, msg, &end))
 638                                msg = strbuf_detach(&msg_buf, NULL);
 639                        else
 640                                msg = xstrdup(msg);
 641                        strbuf_release(&msg_buf);
 642
 643                        if (!strcmp(msg, "no match")) {
 644                                status = REF_STATUS_NONE;
 645                                free(msg);
 646                                msg = NULL;
 647                        }
 648                        else if (!strcmp(msg, "up to date")) {
 649                                status = REF_STATUS_UPTODATE;
 650                                free(msg);
 651                                msg = NULL;
 652                        }
 653                        else if (!strcmp(msg, "non-fast forward")) {
 654                                status = REF_STATUS_REJECT_NONFASTFORWARD;
 655                                free(msg);
 656                                msg = NULL;
 657                        }
 658                }
 659
 660                if (ref)
 661                        ref = find_ref_by_name(ref, refname);
 662                if (!ref)
 663                        ref = find_ref_by_name(remote_refs, refname);
 664                if (!ref) {
 665                        warning("helper reported unexpected status of %s", refname);
 666                        continue;
 667                }
 668
 669                if (ref->status != REF_STATUS_NONE) {
 670                        /*
 671                         * Earlier, the ref was marked not to be pushed, so ignore the ref
 672                         * status reported by the remote helper if the latter is 'no match'.
 673                         */
 674                        if (status == REF_STATUS_NONE)
 675                                continue;
 676                }
 677
 678                ref->status = status;
 679                ref->remote_status = msg;
 680        }
 681        strbuf_release(&buf);
 682        return 0;
 683}
 684
 685static int push_refs_with_export(struct transport *transport,
 686                struct ref *remote_refs, int flags)
 687{
 688        struct ref *ref;
 689        struct child_process *helper, exporter;
 690        struct helper_data *data = transport->data;
 691        char *export_marks = NULL, *import_marks = NULL;
 692        struct string_list revlist_args = STRING_LIST_INIT_NODUP;
 693        struct strbuf buf = STRBUF_INIT;
 694
 695        helper = get_helper(transport);
 696
 697        write_constant(helper->in, "export\n");
 698
 699        recvline(data, &buf);
 700        if (debug)
 701                fprintf(stderr, "Debug: Got export_marks '%s'\n", buf.buf);
 702        if (buf.len) {
 703                struct strbuf arg = STRBUF_INIT;
 704                strbuf_addstr(&arg, "--export-marks=");
 705                strbuf_addbuf(&arg, &buf);
 706                export_marks = strbuf_detach(&arg, NULL);
 707        }
 708
 709        recvline(data, &buf);
 710        if (debug)
 711                fprintf(stderr, "Debug: Got import_marks '%s'\n", buf.buf);
 712        if (buf.len) {
 713                struct strbuf arg = STRBUF_INIT;
 714                strbuf_addstr(&arg, "--import-marks=");
 715                strbuf_addbuf(&arg, &buf);
 716                import_marks = strbuf_detach(&arg, NULL);
 717        }
 718
 719        strbuf_reset(&buf);
 720
 721        for (ref = remote_refs; ref; ref = ref->next) {
 722                char *private;
 723                unsigned char sha1[20];
 724
 725                if (!data->refspecs)
 726                        continue;
 727                private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
 728                if (private && !get_sha1(private, sha1)) {
 729                        strbuf_addf(&buf, "^%s", private);
 730                        string_list_append(&revlist_args, strbuf_detach(&buf, NULL));
 731                }
 732
 733                string_list_append(&revlist_args, ref->name);
 734
 735        }
 736
 737        if (get_exporter(transport, &exporter,
 738                         export_marks, import_marks, &revlist_args))
 739                die("Couldn't run fast-export");
 740
 741        data->no_disconnect_req = 1;
 742        finish_command(&exporter);
 743        disconnect_helper(transport);
 744        return 0;
 745}
 746
 747static int push_refs(struct transport *transport,
 748                struct ref *remote_refs, int flags)
 749{
 750        struct helper_data *data = transport->data;
 751
 752        if (process_connect(transport, 1)) {
 753                do_take_over(transport);
 754                return transport->push_refs(transport, remote_refs, flags);
 755        }
 756
 757        if (!remote_refs) {
 758                fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
 759                        "Perhaps you should specify a branch such as 'master'.\n");
 760                return 0;
 761        }
 762
 763        if (data->push)
 764                return push_refs_with_push(transport, remote_refs, flags);
 765
 766        if (data->export)
 767                return push_refs_with_export(transport, remote_refs, flags);
 768
 769        return -1;
 770}
 771
 772
 773static int has_attribute(const char *attrs, const char *attr) {
 774        int len;
 775        if (!attrs)
 776                return 0;
 777
 778        len = strlen(attr);
 779        for (;;) {
 780                const char *space = strchrnul(attrs, ' ');
 781                if (len == space - attrs && !strncmp(attrs, attr, len))
 782                        return 1;
 783                if (!*space)
 784                        return 0;
 785                attrs = space + 1;
 786        }
 787}
 788
 789static struct ref *get_refs_list(struct transport *transport, int for_push)
 790{
 791        struct helper_data *data = transport->data;
 792        struct child_process *helper;
 793        struct ref *ret = NULL;
 794        struct ref **tail = &ret;
 795        struct ref *posn;
 796        struct strbuf buf = STRBUF_INIT;
 797
 798        helper = get_helper(transport);
 799
 800        if (process_connect(transport, for_push)) {
 801                do_take_over(transport);
 802                return transport->get_refs_list(transport, for_push);
 803        }
 804
 805        if (data->push && for_push)
 806                write_str_in_full(helper->in, "list for-push\n");
 807        else
 808                write_str_in_full(helper->in, "list\n");
 809
 810        while (1) {
 811                char *eov, *eon;
 812                recvline(data, &buf);
 813
 814                if (!*buf.buf)
 815                        break;
 816
 817                eov = strchr(buf.buf, ' ');
 818                if (!eov)
 819                        die("Malformed response in ref list: %s", buf.buf);
 820                eon = strchr(eov + 1, ' ');
 821                *eov = '\0';
 822                if (eon)
 823                        *eon = '\0';
 824                *tail = alloc_ref(eov + 1);
 825                if (buf.buf[0] == '@')
 826                        (*tail)->symref = xstrdup(buf.buf + 1);
 827                else if (buf.buf[0] != '?')
 828                        get_sha1_hex(buf.buf, (*tail)->old_sha1);
 829                if (eon) {
 830                        if (has_attribute(eon + 1, "unchanged")) {
 831                                (*tail)->status |= REF_STATUS_UPTODATE;
 832                                read_ref((*tail)->name, (*tail)->old_sha1);
 833                        }
 834                }
 835                tail = &((*tail)->next);
 836        }
 837        if (debug)
 838                fprintf(stderr, "Debug: Read ref listing.\n");
 839        strbuf_release(&buf);
 840
 841        for (posn = ret; posn; posn = posn->next)
 842                resolve_remote_symref(posn, ret);
 843
 844        return ret;
 845}
 846
 847int transport_helper_init(struct transport *transport, const char *name)
 848{
 849        struct helper_data *data = xcalloc(sizeof(*data), 1);
 850        data->name = name;
 851
 852        if (getenv("GIT_TRANSPORT_HELPER_DEBUG"))
 853                debug = 1;
 854
 855        transport->data = data;
 856        transport->set_option = set_helper_option;
 857        transport->get_refs_list = get_refs_list;
 858        transport->fetch = fetch;
 859        transport->push_refs = push_refs;
 860        transport->disconnect = release_helper;
 861        transport->connect = connect_helper;
 862        transport->smart_options = &(data->transport_options);
 863        return 0;
 864}