e02f4a3e5a1bdbdbd1cfa7a9a1a449e3643485df
   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#include "thread-utils.h"
  12
  13static int debug;
  14
  15struct helper_data {
  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
  79static const 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        char git_dir_buf[sizeof(GIT_DIR_ENVIRONMENT) + PATH_MAX + 1];
 109        const char *helper_env[] = {
 110                git_dir_buf,
 111                NULL
 112        };
 113
 114
 115        if (data->helper)
 116                return data->helper;
 117
 118        helper = xcalloc(1, sizeof(*helper));
 119        helper->in = -1;
 120        helper->out = -1;
 121        helper->err = 0;
 122        helper->argv = xcalloc(4, sizeof(*helper->argv));
 123        strbuf_addf(&buf, "git-remote-%s", data->name);
 124        helper->argv[0] = strbuf_detach(&buf, NULL);
 125        helper->argv[1] = transport->remote->name;
 126        helper->argv[2] = remove_ext_force(transport->url);
 127        helper->git_cmd = 0;
 128        helper->silent_exec_failure = 1;
 129
 130        snprintf(git_dir_buf, sizeof(git_dir_buf), "%s=%s", GIT_DIR_ENVIRONMENT, get_git_dir());
 131        helper->env = helper_env;
 132
 133        code = start_command(helper);
 134        if (code < 0 && errno == ENOENT)
 135                die("Unable to find remote helper for '%s'", data->name);
 136        else if (code != 0)
 137                exit(code);
 138
 139        data->helper = helper;
 140        data->no_disconnect_req = 0;
 141
 142        /*
 143         * Open the output as FILE* so strbuf_getline() can be used.
 144         * Do this with duped fd because fclose() will close the fd,
 145         * and stuff like taking over will require the fd to remain.
 146         */
 147        duped = dup(helper->out);
 148        if (duped < 0)
 149                die_errno("Can't dup helper output fd");
 150        data->out = xfdopen(duped, "r");
 151
 152        write_constant(helper->in, "capabilities\n");
 153
 154        while (1) {
 155                const char *capname;
 156                int mandatory = 0;
 157                recvline(data, &buf);
 158
 159                if (!*buf.buf)
 160                        break;
 161
 162                if (*buf.buf == '*') {
 163                        capname = buf.buf + 1;
 164                        mandatory = 1;
 165                } else
 166                        capname = buf.buf;
 167
 168                if (debug)
 169                        fprintf(stderr, "Debug: Got cap %s\n", capname);
 170                if (!strcmp(capname, "fetch"))
 171                        data->fetch = 1;
 172                else if (!strcmp(capname, "option"))
 173                        data->option = 1;
 174                else if (!strcmp(capname, "push"))
 175                        data->push = 1;
 176                else if (!strcmp(capname, "import"))
 177                        data->import = 1;
 178                else if (!strcmp(capname, "export"))
 179                        data->export = 1;
 180                else if (!data->refspecs && !prefixcmp(capname, "refspec ")) {
 181                        ALLOC_GROW(refspecs,
 182                                   refspec_nr + 1,
 183                                   refspec_alloc);
 184                        refspecs[refspec_nr++] = strdup(buf.buf + strlen("refspec "));
 185                } else if (!strcmp(capname, "connect")) {
 186                        data->connect = 1;
 187                } else if (mandatory) {
 188                        die("Unknown mandatory capability %s. This remote "
 189                            "helper probably needs newer version of Git.\n",
 190                            capname);
 191                }
 192        }
 193        if (refspecs) {
 194                int i;
 195                data->refspec_nr = refspec_nr;
 196                data->refspecs = parse_fetch_refspec(refspec_nr, refspecs);
 197                for (i = 0; i < refspec_nr; i++) {
 198                        free((char *)refspecs[i]);
 199                }
 200                free(refspecs);
 201        }
 202        strbuf_release(&buf);
 203        if (debug)
 204                fprintf(stderr, "Debug: Capabilities complete.\n");
 205        return data->helper;
 206}
 207
 208static int disconnect_helper(struct transport *transport)
 209{
 210        struct helper_data *data = transport->data;
 211        struct strbuf buf = STRBUF_INIT;
 212        int res = 0;
 213
 214        if (data->helper) {
 215                if (debug)
 216                        fprintf(stderr, "Debug: Disconnecting.\n");
 217                if (!data->no_disconnect_req) {
 218                        strbuf_addf(&buf, "\n");
 219                        sendline(data, &buf);
 220                }
 221                close(data->helper->in);
 222                close(data->helper->out);
 223                fclose(data->out);
 224                res = finish_command(data->helper);
 225                free((char *)data->helper->argv[0]);
 226                free(data->helper->argv);
 227                free(data->helper);
 228                data->helper = NULL;
 229        }
 230        return res;
 231}
 232
 233static const char *unsupported_options[] = {
 234        TRANS_OPT_UPLOADPACK,
 235        TRANS_OPT_RECEIVEPACK,
 236        TRANS_OPT_THIN,
 237        TRANS_OPT_KEEP
 238        };
 239static const char *boolean_options[] = {
 240        TRANS_OPT_THIN,
 241        TRANS_OPT_KEEP,
 242        TRANS_OPT_FOLLOWTAGS
 243        };
 244
 245static int set_helper_option(struct transport *transport,
 246                          const char *name, const char *value)
 247{
 248        struct helper_data *data = transport->data;
 249        struct strbuf buf = STRBUF_INIT;
 250        int i, ret, is_bool = 0;
 251
 252        get_helper(transport);
 253
 254        if (!data->option)
 255                return 1;
 256
 257        for (i = 0; i < ARRAY_SIZE(unsupported_options); i++) {
 258                if (!strcmp(name, unsupported_options[i]))
 259                        return 1;
 260        }
 261
 262        for (i = 0; i < ARRAY_SIZE(boolean_options); i++) {
 263                if (!strcmp(name, boolean_options[i])) {
 264                        is_bool = 1;
 265                        break;
 266                }
 267        }
 268
 269        strbuf_addf(&buf, "option %s ", name);
 270        if (is_bool)
 271                strbuf_addstr(&buf, value ? "true" : "false");
 272        else
 273                quote_c_style(value, &buf, NULL, 0);
 274        strbuf_addch(&buf, '\n');
 275
 276        xchgline(data, &buf);
 277
 278        if (!strcmp(buf.buf, "ok"))
 279                ret = 0;
 280        else if (!prefixcmp(buf.buf, "error")) {
 281                ret = -1;
 282        } else if (!strcmp(buf.buf, "unsupported"))
 283                ret = 1;
 284        else {
 285                warning("%s unexpectedly said: '%s'", data->name, buf.buf);
 286                ret = 1;
 287        }
 288        strbuf_release(&buf);
 289        return ret;
 290}
 291
 292static void standard_options(struct transport *t)
 293{
 294        char buf[16];
 295        int n;
 296        int v = t->verbose;
 297
 298        set_helper_option(t, "progress", t->progress ? "true" : "false");
 299
 300        n = snprintf(buf, sizeof(buf), "%d", v + 1);
 301        if (n >= sizeof(buf))
 302                die("impossibly large verbosity value");
 303        set_helper_option(t, "verbosity", buf);
 304}
 305
 306static int release_helper(struct transport *transport)
 307{
 308        int res = 0;
 309        struct helper_data *data = transport->data;
 310        free_refspec(data->refspec_nr, data->refspecs);
 311        data->refspecs = NULL;
 312        res = disconnect_helper(transport);
 313        free(transport->data);
 314        return res;
 315}
 316
 317static int fetch_with_fetch(struct transport *transport,
 318                            int nr_heads, struct ref **to_fetch)
 319{
 320        struct helper_data *data = transport->data;
 321        int i;
 322        struct strbuf buf = STRBUF_INIT;
 323
 324        standard_options(transport);
 325
 326        for (i = 0; i < nr_heads; i++) {
 327                const struct ref *posn = to_fetch[i];
 328                if (posn->status & REF_STATUS_UPTODATE)
 329                        continue;
 330
 331                strbuf_addf(&buf, "fetch %s %s\n",
 332                            sha1_to_hex(posn->old_sha1), posn->name);
 333        }
 334
 335        strbuf_addch(&buf, '\n');
 336        sendline(data, &buf);
 337
 338        while (1) {
 339                recvline(data, &buf);
 340
 341                if (!prefixcmp(buf.buf, "lock ")) {
 342                        const char *name = buf.buf + 5;
 343                        if (transport->pack_lockfile)
 344                                warning("%s also locked %s", data->name, name);
 345                        else
 346                                transport->pack_lockfile = xstrdup(name);
 347                }
 348                else if (!buf.len)
 349                        break;
 350                else
 351                        warning("%s unexpectedly said: '%s'", data->name, buf.buf);
 352        }
 353        strbuf_release(&buf);
 354        return 0;
 355}
 356
 357static int get_importer(struct transport *transport, struct child_process *fastimport)
 358{
 359        struct child_process *helper = get_helper(transport);
 360        memset(fastimport, 0, sizeof(*fastimport));
 361        fastimport->in = helper->out;
 362        fastimport->argv = xcalloc(5, sizeof(*fastimport->argv));
 363        fastimport->argv[0] = "fast-import";
 364        fastimport->argv[1] = "--quiet";
 365
 366        fastimport->git_cmd = 1;
 367        return start_command(fastimport);
 368}
 369
 370static int get_exporter(struct transport *transport,
 371                        struct child_process *fastexport,
 372                        const char *export_marks,
 373                        const char *import_marks,
 374                        struct string_list *revlist_args)
 375{
 376        struct child_process *helper = get_helper(transport);
 377        int argc = 0, i;
 378        memset(fastexport, 0, sizeof(*fastexport));
 379
 380        /* we need to duplicate helper->in because we want to use it after
 381         * fastexport is done with it. */
 382        fastexport->out = dup(helper->in);
 383        fastexport->argv = xcalloc(4 + revlist_args->nr, sizeof(*fastexport->argv));
 384        fastexport->argv[argc++] = "fast-export";
 385        if (export_marks)
 386                fastexport->argv[argc++] = export_marks;
 387        if (import_marks)
 388                fastexport->argv[argc++] = import_marks;
 389
 390        for (i = 0; i < revlist_args->nr; i++)
 391                fastexport->argv[argc++] = revlist_args->items[i].string;
 392
 393        fastexport->git_cmd = 1;
 394        return start_command(fastexport);
 395}
 396
 397static int fetch_with_import(struct transport *transport,
 398                             int nr_heads, struct ref **to_fetch)
 399{
 400        struct child_process fastimport;
 401        struct helper_data *data = transport->data;
 402        int i;
 403        struct ref *posn;
 404        struct strbuf buf = STRBUF_INIT;
 405
 406        get_helper(transport);
 407
 408        if (get_importer(transport, &fastimport))
 409                die("Couldn't run fast-import");
 410
 411        for (i = 0; i < nr_heads; i++) {
 412                posn = to_fetch[i];
 413                if (posn->status & REF_STATUS_UPTODATE)
 414                        continue;
 415
 416                strbuf_addf(&buf, "import %s\n", posn->name);
 417                sendline(data, &buf);
 418                strbuf_reset(&buf);
 419        }
 420        if (disconnect_helper(transport))
 421                die("Error while disconnecting helper");
 422        if (finish_command(&fastimport))
 423                die("Error while running fast-import");
 424
 425        free(fastimport.argv);
 426        fastimport.argv = NULL;
 427
 428        for (i = 0; i < nr_heads; i++) {
 429                char *private;
 430                posn = to_fetch[i];
 431                if (posn->status & REF_STATUS_UPTODATE)
 432                        continue;
 433                if (data->refspecs)
 434                        private = apply_refspecs(data->refspecs, data->refspec_nr, posn->name);
 435                else
 436                        private = strdup(posn->name);
 437                read_ref(private, posn->old_sha1);
 438                free(private);
 439        }
 440        strbuf_release(&buf);
 441        return 0;
 442}
 443
 444static int process_connect_service(struct transport *transport,
 445                                   const char *name, const char *exec)
 446{
 447        struct helper_data *data = transport->data;
 448        struct strbuf cmdbuf = STRBUF_INIT;
 449        struct child_process *helper;
 450        int r, duped, ret = 0;
 451        FILE *input;
 452
 453        helper = get_helper(transport);
 454
 455        /*
 456         * Yes, dup the pipe another time, as we need unbuffered version
 457         * of input pipe as FILE*. fclose() closes the underlying fd and
 458         * stream buffering only can be changed before first I/O operation
 459         * on it.
 460         */
 461        duped = dup(helper->out);
 462        if (duped < 0)
 463                die_errno("Can't dup helper output fd");
 464        input = xfdopen(duped, "r");
 465        setvbuf(input, NULL, _IONBF, 0);
 466
 467        /*
 468         * Handle --upload-pack and friends. This is fire and forget...
 469         * just warn if it fails.
 470         */
 471        if (strcmp(name, exec)) {
 472                r = set_helper_option(transport, "servpath", exec);
 473                if (r > 0)
 474                        warning("Setting remote service path not supported by protocol.");
 475                else if (r < 0)
 476                        warning("Invalid remote service path.");
 477        }
 478
 479        if (data->connect)
 480                strbuf_addf(&cmdbuf, "connect %s\n", name);
 481        else
 482                goto exit;
 483
 484        sendline(data, &cmdbuf);
 485        recvline_fh(input, &cmdbuf);
 486        if (!strcmp(cmdbuf.buf, "")) {
 487                data->no_disconnect_req = 1;
 488                if (debug)
 489                        fprintf(stderr, "Debug: Smart transport connection "
 490                                "ready.\n");
 491                ret = 1;
 492        } else if (!strcmp(cmdbuf.buf, "fallback")) {
 493                if (debug)
 494                        fprintf(stderr, "Debug: Falling back to dumb "
 495                                "transport.\n");
 496        } else
 497                die("Unknown response to connect: %s",
 498                        cmdbuf.buf);
 499
 500exit:
 501        fclose(input);
 502        return ret;
 503}
 504
 505static int process_connect(struct transport *transport,
 506                                     int for_push)
 507{
 508        struct helper_data *data = transport->data;
 509        const char *name;
 510        const char *exec;
 511
 512        name = for_push ? "git-receive-pack" : "git-upload-pack";
 513        if (for_push)
 514                exec = data->transport_options.receivepack;
 515        else
 516                exec = data->transport_options.uploadpack;
 517
 518        return process_connect_service(transport, name, exec);
 519}
 520
 521static int connect_helper(struct transport *transport, const char *name,
 522                   const char *exec, int fd[2])
 523{
 524        struct helper_data *data = transport->data;
 525
 526        /* Get_helper so connect is inited. */
 527        get_helper(transport);
 528        if (!data->connect)
 529                die("Operation not supported by protocol.");
 530
 531        if (!process_connect_service(transport, name, exec))
 532                die("Can't connect to subservice %s.", name);
 533
 534        fd[0] = data->helper->out;
 535        fd[1] = data->helper->in;
 536        return 0;
 537}
 538
 539static int fetch(struct transport *transport,
 540                 int nr_heads, struct ref **to_fetch)
 541{
 542        struct helper_data *data = transport->data;
 543        int i, count;
 544
 545        if (process_connect(transport, 0)) {
 546                do_take_over(transport);
 547                return transport->fetch(transport, nr_heads, to_fetch);
 548        }
 549
 550        count = 0;
 551        for (i = 0; i < nr_heads; i++)
 552                if (!(to_fetch[i]->status & REF_STATUS_UPTODATE))
 553                        count++;
 554
 555        if (!count)
 556                return 0;
 557
 558        if (data->fetch)
 559                return fetch_with_fetch(transport, nr_heads, to_fetch);
 560
 561        if (data->import)
 562                return fetch_with_import(transport, nr_heads, to_fetch);
 563
 564        return -1;
 565}
 566
 567static void push_update_ref_status(struct strbuf *buf,
 568                                   struct ref **ref,
 569                                   struct ref *remote_refs)
 570{
 571        char *refname, *msg;
 572        int status;
 573
 574        if (!prefixcmp(buf->buf, "ok ")) {
 575                status = REF_STATUS_OK;
 576                refname = buf->buf + 3;
 577        } else if (!prefixcmp(buf->buf, "error ")) {
 578                status = REF_STATUS_REMOTE_REJECT;
 579                refname = buf->buf + 6;
 580        } else
 581                die("expected ok/error, helper said '%s'\n", buf->buf);
 582
 583        msg = strchr(refname, ' ');
 584        if (msg) {
 585                struct strbuf msg_buf = STRBUF_INIT;
 586                const char *end;
 587
 588                *msg++ = '\0';
 589                if (!unquote_c_style(&msg_buf, msg, &end))
 590                        msg = strbuf_detach(&msg_buf, NULL);
 591                else
 592                        msg = xstrdup(msg);
 593                strbuf_release(&msg_buf);
 594
 595                if (!strcmp(msg, "no match")) {
 596                        status = REF_STATUS_NONE;
 597                        free(msg);
 598                        msg = NULL;
 599                }
 600                else if (!strcmp(msg, "up to date")) {
 601                        status = REF_STATUS_UPTODATE;
 602                        free(msg);
 603                        msg = NULL;
 604                }
 605                else if (!strcmp(msg, "non-fast forward")) {
 606                        status = REF_STATUS_REJECT_NONFASTFORWARD;
 607                        free(msg);
 608                        msg = NULL;
 609                }
 610        }
 611
 612        if (*ref)
 613                *ref = find_ref_by_name(*ref, refname);
 614        if (!*ref)
 615                *ref = find_ref_by_name(remote_refs, refname);
 616        if (!*ref) {
 617                warning("helper reported unexpected status of %s", refname);
 618                return;
 619        }
 620
 621        if ((*ref)->status != REF_STATUS_NONE) {
 622                /*
 623                 * Earlier, the ref was marked not to be pushed, so ignore the ref
 624                 * status reported by the remote helper if the latter is 'no match'.
 625                 */
 626                if (status == REF_STATUS_NONE)
 627                        return;
 628        }
 629
 630        (*ref)->status = status;
 631        (*ref)->remote_status = msg;
 632}
 633
 634static void push_update_refs_status(struct helper_data *data,
 635                                    struct ref *remote_refs)
 636{
 637        struct strbuf buf = STRBUF_INIT;
 638        struct ref *ref = remote_refs;
 639        for (;;) {
 640                recvline(data, &buf);
 641                if (!buf.len)
 642                        break;
 643
 644                push_update_ref_status(&buf, &ref, remote_refs);
 645        }
 646        strbuf_release(&buf);
 647}
 648
 649static int push_refs_with_push(struct transport *transport,
 650                struct ref *remote_refs, int flags)
 651{
 652        int force_all = flags & TRANSPORT_PUSH_FORCE;
 653        int mirror = flags & TRANSPORT_PUSH_MIRROR;
 654        struct helper_data *data = transport->data;
 655        struct strbuf buf = STRBUF_INIT;
 656        struct ref *ref;
 657
 658        get_helper(transport);
 659        if (!data->push)
 660                return 1;
 661
 662        for (ref = remote_refs; ref; ref = ref->next) {
 663                if (!ref->peer_ref && !mirror)
 664                        continue;
 665
 666                /* Check for statuses set by set_ref_status_for_push() */
 667                switch (ref->status) {
 668                case REF_STATUS_REJECT_NONFASTFORWARD:
 669                case REF_STATUS_UPTODATE:
 670                        continue;
 671                default:
 672                        ; /* do nothing */
 673                }
 674
 675                if (force_all)
 676                        ref->force = 1;
 677
 678                strbuf_addstr(&buf, "push ");
 679                if (!ref->deletion) {
 680                        if (ref->force)
 681                                strbuf_addch(&buf, '+');
 682                        if (ref->peer_ref)
 683                                strbuf_addstr(&buf, ref->peer_ref->name);
 684                        else
 685                                strbuf_addstr(&buf, sha1_to_hex(ref->new_sha1));
 686                }
 687                strbuf_addch(&buf, ':');
 688                strbuf_addstr(&buf, ref->name);
 689                strbuf_addch(&buf, '\n');
 690        }
 691        if (buf.len == 0)
 692                return 0;
 693
 694        standard_options(transport);
 695
 696        if (flags & TRANSPORT_PUSH_DRY_RUN) {
 697                if (set_helper_option(transport, "dry-run", "true") != 0)
 698                        die("helper %s does not support dry-run", data->name);
 699        }
 700
 701        strbuf_addch(&buf, '\n');
 702        sendline(data, &buf);
 703        strbuf_release(&buf);
 704
 705        push_update_refs_status(data, remote_refs);
 706        return 0;
 707}
 708
 709static int push_refs_with_export(struct transport *transport,
 710                struct ref *remote_refs, int flags)
 711{
 712        struct ref *ref;
 713        struct child_process *helper, exporter;
 714        struct helper_data *data = transport->data;
 715        char *export_marks = NULL, *import_marks = NULL;
 716        struct string_list revlist_args = STRING_LIST_INIT_NODUP;
 717        struct strbuf buf = STRBUF_INIT;
 718
 719        helper = get_helper(transport);
 720
 721        write_constant(helper->in, "export\n");
 722
 723        recvline(data, &buf);
 724        if (debug)
 725                fprintf(stderr, "Debug: Got export_marks '%s'\n", buf.buf);
 726        if (buf.len) {
 727                struct strbuf arg = STRBUF_INIT;
 728                strbuf_addstr(&arg, "--export-marks=");
 729                strbuf_addbuf(&arg, &buf);
 730                export_marks = strbuf_detach(&arg, NULL);
 731        }
 732
 733        recvline(data, &buf);
 734        if (debug)
 735                fprintf(stderr, "Debug: Got import_marks '%s'\n", buf.buf);
 736        if (buf.len) {
 737                struct strbuf arg = STRBUF_INIT;
 738                strbuf_addstr(&arg, "--import-marks=");
 739                strbuf_addbuf(&arg, &buf);
 740                import_marks = strbuf_detach(&arg, NULL);
 741        }
 742
 743        strbuf_reset(&buf);
 744
 745        for (ref = remote_refs; ref; ref = ref->next) {
 746                char *private;
 747                unsigned char sha1[20];
 748
 749                if (!data->refspecs)
 750                        continue;
 751                private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
 752                if (private && !get_sha1(private, sha1)) {
 753                        strbuf_addf(&buf, "^%s", private);
 754                        string_list_append(&revlist_args, strbuf_detach(&buf, NULL));
 755                }
 756                free(private);
 757
 758                if (ref->peer_ref)
 759                        string_list_append(&revlist_args, ref->peer_ref->name);
 760
 761        }
 762
 763        if (get_exporter(transport, &exporter,
 764                         export_marks, import_marks, &revlist_args))
 765                die("Couldn't run fast-export");
 766
 767        data->no_disconnect_req = 1;
 768        if (finish_command(&exporter))
 769                die("Error while running fast-export");
 770        if (disconnect_helper(transport))
 771                die("Error while disconnecting helper");
 772        return 0;
 773}
 774
 775static int push_refs(struct transport *transport,
 776                struct ref *remote_refs, int flags)
 777{
 778        struct helper_data *data = transport->data;
 779
 780        if (process_connect(transport, 1)) {
 781                do_take_over(transport);
 782                return transport->push_refs(transport, remote_refs, flags);
 783        }
 784
 785        if (!remote_refs) {
 786                fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
 787                        "Perhaps you should specify a branch such as 'master'.\n");
 788                return 0;
 789        }
 790
 791        if (data->push)
 792                return push_refs_with_push(transport, remote_refs, flags);
 793
 794        if (data->export)
 795                return push_refs_with_export(transport, remote_refs, flags);
 796
 797        return -1;
 798}
 799
 800
 801static int has_attribute(const char *attrs, const char *attr) {
 802        int len;
 803        if (!attrs)
 804                return 0;
 805
 806        len = strlen(attr);
 807        for (;;) {
 808                const char *space = strchrnul(attrs, ' ');
 809                if (len == space - attrs && !strncmp(attrs, attr, len))
 810                        return 1;
 811                if (!*space)
 812                        return 0;
 813                attrs = space + 1;
 814        }
 815}
 816
 817static struct ref *get_refs_list(struct transport *transport, int for_push)
 818{
 819        struct helper_data *data = transport->data;
 820        struct child_process *helper;
 821        struct ref *ret = NULL;
 822        struct ref **tail = &ret;
 823        struct ref *posn;
 824        struct strbuf buf = STRBUF_INIT;
 825
 826        helper = get_helper(transport);
 827
 828        if (process_connect(transport, for_push)) {
 829                do_take_over(transport);
 830                return transport->get_refs_list(transport, for_push);
 831        }
 832
 833        if (data->push && for_push)
 834                write_str_in_full(helper->in, "list for-push\n");
 835        else
 836                write_str_in_full(helper->in, "list\n");
 837
 838        while (1) {
 839                char *eov, *eon;
 840                recvline(data, &buf);
 841
 842                if (!*buf.buf)
 843                        break;
 844
 845                eov = strchr(buf.buf, ' ');
 846                if (!eov)
 847                        die("Malformed response in ref list: %s", buf.buf);
 848                eon = strchr(eov + 1, ' ');
 849                *eov = '\0';
 850                if (eon)
 851                        *eon = '\0';
 852                *tail = alloc_ref(eov + 1);
 853                if (buf.buf[0] == '@')
 854                        (*tail)->symref = xstrdup(buf.buf + 1);
 855                else if (buf.buf[0] != '?')
 856                        get_sha1_hex(buf.buf, (*tail)->old_sha1);
 857                if (eon) {
 858                        if (has_attribute(eon + 1, "unchanged")) {
 859                                (*tail)->status |= REF_STATUS_UPTODATE;
 860                                read_ref((*tail)->name, (*tail)->old_sha1);
 861                        }
 862                }
 863                tail = &((*tail)->next);
 864        }
 865        if (debug)
 866                fprintf(stderr, "Debug: Read ref listing.\n");
 867        strbuf_release(&buf);
 868
 869        for (posn = ret; posn; posn = posn->next)
 870                resolve_remote_symref(posn, ret);
 871
 872        return ret;
 873}
 874
 875int transport_helper_init(struct transport *transport, const char *name)
 876{
 877        struct helper_data *data = xcalloc(sizeof(*data), 1);
 878        data->name = name;
 879
 880        if (getenv("GIT_TRANSPORT_HELPER_DEBUG"))
 881                debug = 1;
 882
 883        transport->data = data;
 884        transport->set_option = set_helper_option;
 885        transport->get_refs_list = get_refs_list;
 886        transport->fetch = fetch;
 887        transport->push_refs = push_refs;
 888        transport->disconnect = release_helper;
 889        transport->connect = connect_helper;
 890        transport->smart_options = &(data->transport_options);
 891        return 0;
 892}
 893
 894/*
 895 * Linux pipes can buffer 65536 bytes at once (and most platforms can
 896 * buffer less), so attempt reads and writes with up to that size.
 897 */
 898#define BUFFERSIZE 65536
 899/* This should be enough to hold debugging message. */
 900#define PBUFFERSIZE 8192
 901
 902/* Print bidirectional transfer loop debug message. */
 903static void transfer_debug(const char *fmt, ...)
 904{
 905        va_list args;
 906        char msgbuf[PBUFFERSIZE];
 907        static int debug_enabled = -1;
 908
 909        if (debug_enabled < 0)
 910                debug_enabled = getenv("GIT_TRANSLOOP_DEBUG") ? 1 : 0;
 911        if (!debug_enabled)
 912                return;
 913
 914        va_start(args, fmt);
 915        vsnprintf(msgbuf, PBUFFERSIZE, fmt, args);
 916        va_end(args);
 917        fprintf(stderr, "Transfer loop debugging: %s\n", msgbuf);
 918}
 919
 920/* Stream state: More data may be coming in this direction. */
 921#define SSTATE_TRANSFERING 0
 922/*
 923 * Stream state: No more data coming in this direction, flushing rest of
 924 * data.
 925 */
 926#define SSTATE_FLUSHING 1
 927/* Stream state: Transfer in this direction finished. */
 928#define SSTATE_FINISHED 2
 929
 930#define STATE_NEEDS_READING(state) ((state) <= SSTATE_TRANSFERING)
 931#define STATE_NEEDS_WRITING(state) ((state) <= SSTATE_FLUSHING)
 932#define STATE_NEEDS_CLOSING(state) ((state) == SSTATE_FLUSHING)
 933
 934/* Unidirectional transfer. */
 935struct unidirectional_transfer {
 936        /* Source */
 937        int src;
 938        /* Destination */
 939        int dest;
 940        /* Is source socket? */
 941        int src_is_sock;
 942        /* Is destination socket? */
 943        int dest_is_sock;
 944        /* Transfer state (TRANSFERING/FLUSHING/FINISHED) */
 945        int state;
 946        /* Buffer. */
 947        char buf[BUFFERSIZE];
 948        /* Buffer used. */
 949        size_t bufuse;
 950        /* Name of source. */
 951        const char *src_name;
 952        /* Name of destination. */
 953        const char *dest_name;
 954};
 955
 956/* Closes the target (for writing) if transfer has finished. */
 957static void udt_close_if_finished(struct unidirectional_transfer *t)
 958{
 959        if (STATE_NEEDS_CLOSING(t->state) && !t->bufuse) {
 960                t->state = SSTATE_FINISHED;
 961                if (t->dest_is_sock)
 962                        shutdown(t->dest, SHUT_WR);
 963                else
 964                        close(t->dest);
 965                transfer_debug("Closed %s.", t->dest_name);
 966        }
 967}
 968
 969/*
 970 * Tries to read read data from source into buffer. If buffer is full,
 971 * no data is read. Returns 0 on success, -1 on error.
 972 */
 973static int udt_do_read(struct unidirectional_transfer *t)
 974{
 975        ssize_t bytes;
 976
 977        if (t->bufuse == BUFFERSIZE)
 978                return 0;       /* No space for more. */
 979
 980        transfer_debug("%s is readable", t->src_name);
 981        bytes = read(t->src, t->buf + t->bufuse, BUFFERSIZE - t->bufuse);
 982        if (bytes < 0 && errno != EWOULDBLOCK && errno != EAGAIN &&
 983                errno != EINTR) {
 984                error("read(%s) failed: %s", t->src_name, strerror(errno));
 985                return -1;
 986        } else if (bytes == 0) {
 987                transfer_debug("%s EOF (with %i bytes in buffer)",
 988                        t->src_name, t->bufuse);
 989                t->state = SSTATE_FLUSHING;
 990        } else if (bytes > 0) {
 991                t->bufuse += bytes;
 992                transfer_debug("Read %i bytes from %s (buffer now at %i)",
 993                        (int)bytes, t->src_name, (int)t->bufuse);
 994        }
 995        return 0;
 996}
 997
 998/* Tries to write data from buffer into destination. If buffer is empty,
 999 * no data is written. Returns 0 on success, -1 on error.
1000 */
1001static int udt_do_write(struct unidirectional_transfer *t)
1002{
1003        ssize_t bytes;
1004
1005        if (t->bufuse == 0)
1006                return 0;       /* Nothing to write. */
1007
1008        transfer_debug("%s is writable", t->dest_name);
1009        bytes = write(t->dest, t->buf, t->bufuse);
1010        if (bytes < 0 && errno != EWOULDBLOCK && errno != EAGAIN &&
1011                errno != EINTR) {
1012                error("write(%s) failed: %s", t->dest_name, strerror(errno));
1013                return -1;
1014        } else if (bytes > 0) {
1015                t->bufuse -= bytes;
1016                if (t->bufuse)
1017                        memmove(t->buf, t->buf + bytes, t->bufuse);
1018                transfer_debug("Wrote %i bytes to %s (buffer now at %i)",
1019                        (int)bytes, t->dest_name, (int)t->bufuse);
1020        }
1021        return 0;
1022}
1023
1024
1025/* State of bidirectional transfer loop. */
1026struct bidirectional_transfer_state {
1027        /* Direction from program to git. */
1028        struct unidirectional_transfer ptg;
1029        /* Direction from git to program. */
1030        struct unidirectional_transfer gtp;
1031};
1032
1033static void *udt_copy_task_routine(void *udt)
1034{
1035        struct unidirectional_transfer *t = (struct unidirectional_transfer *)udt;
1036        while (t->state != SSTATE_FINISHED) {
1037                if (STATE_NEEDS_READING(t->state))
1038                        if (udt_do_read(t))
1039                                return NULL;
1040                if (STATE_NEEDS_WRITING(t->state))
1041                        if (udt_do_write(t))
1042                                return NULL;
1043                if (STATE_NEEDS_CLOSING(t->state))
1044                        udt_close_if_finished(t);
1045        }
1046        return udt;     /* Just some non-NULL value. */
1047}
1048
1049#ifndef NO_PTHREADS
1050
1051/*
1052 * Join thread, with apporiate errors on failure. Name is name for the
1053 * thread (for error messages). Returns 0 on success, 1 on failure.
1054 */
1055static int tloop_join(pthread_t thread, const char *name)
1056{
1057        int err;
1058        void *tret;
1059        err = pthread_join(thread, &tret);
1060        if (!tret) {
1061                error("%s thread failed", name);
1062                return 1;
1063        }
1064        if (err) {
1065                error("%s thread failed to join: %s", name, strerror(err));
1066                return 1;
1067        }
1068        return 0;
1069}
1070
1071/*
1072 * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1073 * -1 on failure.
1074 */
1075static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1076{
1077        pthread_t gtp_thread;
1078        pthread_t ptg_thread;
1079        int err;
1080        int ret = 0;
1081        err = pthread_create(&gtp_thread, NULL, udt_copy_task_routine,
1082                &s->gtp);
1083        if (err)
1084                die("Can't start thread for copying data: %s", strerror(err));
1085        err = pthread_create(&ptg_thread, NULL, udt_copy_task_routine,
1086                &s->ptg);
1087        if (err)
1088                die("Can't start thread for copying data: %s", strerror(err));
1089
1090        ret |= tloop_join(gtp_thread, "Git to program copy");
1091        ret |= tloop_join(ptg_thread, "Program to git copy");
1092        return ret;
1093}
1094#else
1095
1096/* Close the source and target (for writing) for transfer. */
1097static void udt_kill_transfer(struct unidirectional_transfer *t)
1098{
1099        t->state = SSTATE_FINISHED;
1100        /*
1101         * Socket read end left open isn't a disaster if nobody
1102         * attempts to read from it (mingw compat headers do not
1103         * have SHUT_RD)...
1104         *
1105         * We can't fully close the socket since otherwise gtp
1106         * task would first close the socket it sends data to
1107         * while closing the ptg file descriptors.
1108         */
1109        if (!t->src_is_sock)
1110                close(t->src);
1111        if (t->dest_is_sock)
1112                shutdown(t->dest, SHUT_WR);
1113        else
1114                close(t->dest);
1115}
1116
1117/*
1118 * Join process, with apporiate errors on failure. Name is name for the
1119 * process (for error messages). Returns 0 on success, 1 on failure.
1120 */
1121static int tloop_join(pid_t pid, const char *name)
1122{
1123        int tret;
1124        if (waitpid(pid, &tret, 0) < 0) {
1125                error("%s process failed to wait: %s", name, strerror(errno));
1126                return 1;
1127        }
1128        if (!WIFEXITED(tret) || WEXITSTATUS(tret)) {
1129                error("%s process failed", name);
1130                return 1;
1131        }
1132        return 0;
1133}
1134
1135/*
1136 * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1137 * -1 on failure.
1138 */
1139static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1140{
1141        pid_t pid1, pid2;
1142        int ret = 0;
1143
1144        /* Fork thread #1: git to program. */
1145        pid1 = fork();
1146        if (pid1 < 0)
1147                die_errno("Can't start thread for copying data");
1148        else if (pid1 == 0) {
1149                udt_kill_transfer(&s->ptg);
1150                exit(udt_copy_task_routine(&s->gtp) ? 0 : 1);
1151        }
1152
1153        /* Fork thread #2: program to git. */
1154        pid2 = fork();
1155        if (pid2 < 0)
1156                die_errno("Can't start thread for copying data");
1157        else if (pid2 == 0) {
1158                udt_kill_transfer(&s->gtp);
1159                exit(udt_copy_task_routine(&s->ptg) ? 0 : 1);
1160        }
1161
1162        /*
1163         * Close both streams in parent as to not interfere with
1164         * end of file detection and wait for both tasks to finish.
1165         */
1166        udt_kill_transfer(&s->gtp);
1167        udt_kill_transfer(&s->ptg);
1168        ret |= tloop_join(pid1, "Git to program copy");
1169        ret |= tloop_join(pid2, "Program to git copy");
1170        return ret;
1171}
1172#endif
1173
1174/*
1175 * Copies data from stdin to output and from input to stdout simultaneously.
1176 * Additionally filtering through given filter. If filter is NULL, uses
1177 * identity filter.
1178 */
1179int bidirectional_transfer_loop(int input, int output)
1180{
1181        struct bidirectional_transfer_state state;
1182
1183        /* Fill the state fields. */
1184        state.ptg.src = input;
1185        state.ptg.dest = 1;
1186        state.ptg.src_is_sock = (input == output);
1187        state.ptg.dest_is_sock = 0;
1188        state.ptg.state = SSTATE_TRANSFERING;
1189        state.ptg.bufuse = 0;
1190        state.ptg.src_name = "remote input";
1191        state.ptg.dest_name = "stdout";
1192
1193        state.gtp.src = 0;
1194        state.gtp.dest = output;
1195        state.gtp.src_is_sock = 0;
1196        state.gtp.dest_is_sock = (input == output);
1197        state.gtp.state = SSTATE_TRANSFERING;
1198        state.gtp.bufuse = 0;
1199        state.gtp.src_name = "stdin";
1200        state.gtp.dest_name = "remote output";
1201
1202        return tloop_spawnwait_tasks(&state);
1203}