transport-helper.con commit Merge branch 'tr/maint-parseopt-avoid-empty' (800981f)
   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#include "sigchain.h"
  13
  14static int debug;
  15
  16struct helper_data {
  17        const char *name;
  18        struct child_process *helper;
  19        FILE *out;
  20        unsigned fetch : 1,
  21                import : 1,
  22                export : 1,
  23                option : 1,
  24                push : 1,
  25                connect : 1,
  26                no_disconnect_req : 1;
  27        char *export_marks;
  28        char *import_marks;
  29        /* These go from remote name (as in "list") to private name */
  30        struct refspec *refspecs;
  31        int refspec_nr;
  32        /* Transport options for fetch-pack/send-pack (should one of
  33         * those be invoked).
  34         */
  35        struct git_transport_options transport_options;
  36};
  37
  38static void sendline(struct helper_data *helper, struct strbuf *buffer)
  39{
  40        if (debug)
  41                fprintf(stderr, "Debug: Remote helper: -> %s", buffer->buf);
  42        if (write_in_full(helper->helper->in, buffer->buf, buffer->len)
  43                != buffer->len)
  44                die_errno("Full write to remote helper failed");
  45}
  46
  47static int recvline_fh(FILE *helper, struct strbuf *buffer)
  48{
  49        strbuf_reset(buffer);
  50        if (debug)
  51                fprintf(stderr, "Debug: Remote helper: Waiting...\n");
  52        if (strbuf_getline(buffer, helper, '\n') == EOF) {
  53                if (debug)
  54                        fprintf(stderr, "Debug: Remote helper quit.\n");
  55                exit(128);
  56        }
  57
  58        if (debug)
  59                fprintf(stderr, "Debug: Remote helper: <- %s\n", buffer->buf);
  60        return 0;
  61}
  62
  63static int recvline(struct helper_data *helper, struct strbuf *buffer)
  64{
  65        return recvline_fh(helper->out, buffer);
  66}
  67
  68static void xchgline(struct helper_data *helper, struct strbuf *buffer)
  69{
  70        sendline(helper, buffer);
  71        recvline(helper, buffer);
  72}
  73
  74static void write_constant(int fd, const char *str)
  75{
  76        if (debug)
  77                fprintf(stderr, "Debug: Remote helper: -> %s", str);
  78        if (write_in_full(fd, str, strlen(str)) != strlen(str))
  79                die_errno("Full write to remote helper failed");
  80}
  81
  82static const char *remove_ext_force(const char *url)
  83{
  84        if (url) {
  85                const char *colon = strchr(url, ':');
  86                if (colon && colon[1] == ':')
  87                        return colon + 2;
  88        }
  89        return url;
  90}
  91
  92static void do_take_over(struct transport *transport)
  93{
  94        struct helper_data *data;
  95        data = (struct helper_data *)transport->data;
  96        transport_take_over(transport, data->helper);
  97        fclose(data->out);
  98        free(data);
  99}
 100
 101static struct child_process *get_helper(struct transport *transport)
 102{
 103        struct helper_data *data = transport->data;
 104        struct strbuf buf = STRBUF_INIT;
 105        struct child_process *helper;
 106        const char **refspecs = NULL;
 107        int refspec_nr = 0;
 108        int refspec_alloc = 0;
 109        int duped;
 110        int code;
 111        char git_dir_buf[sizeof(GIT_DIR_ENVIRONMENT) + PATH_MAX + 1];
 112        const char *helper_env[] = {
 113                git_dir_buf,
 114                NULL
 115        };
 116
 117
 118        if (data->helper)
 119                return data->helper;
 120
 121        helper = xcalloc(1, sizeof(*helper));
 122        helper->in = -1;
 123        helper->out = -1;
 124        helper->err = 0;
 125        helper->argv = xcalloc(4, sizeof(*helper->argv));
 126        strbuf_addf(&buf, "git-remote-%s", data->name);
 127        helper->argv[0] = strbuf_detach(&buf, NULL);
 128        helper->argv[1] = transport->remote->name;
 129        helper->argv[2] = remove_ext_force(transport->url);
 130        helper->git_cmd = 0;
 131        helper->silent_exec_failure = 1;
 132
 133        snprintf(git_dir_buf, sizeof(git_dir_buf), "%s=%s", GIT_DIR_ENVIRONMENT, get_git_dir());
 134        helper->env = helper_env;
 135
 136        code = start_command(helper);
 137        if (code < 0 && errno == ENOENT)
 138                die("Unable to find remote helper for '%s'", data->name);
 139        else if (code != 0)
 140                exit(code);
 141
 142        data->helper = helper;
 143        data->no_disconnect_req = 0;
 144
 145        /*
 146         * Open the output as FILE* so strbuf_getline() can be used.
 147         * Do this with duped fd because fclose() will close the fd,
 148         * and stuff like taking over will require the fd to remain.
 149         */
 150        duped = dup(helper->out);
 151        if (duped < 0)
 152                die_errno("Can't dup helper output fd");
 153        data->out = xfdopen(duped, "r");
 154
 155        write_constant(helper->in, "capabilities\n");
 156
 157        while (1) {
 158                const char *capname;
 159                int mandatory = 0;
 160                recvline(data, &buf);
 161
 162                if (!*buf.buf)
 163                        break;
 164
 165                if (*buf.buf == '*') {
 166                        capname = buf.buf + 1;
 167                        mandatory = 1;
 168                } else
 169                        capname = buf.buf;
 170
 171                if (debug)
 172                        fprintf(stderr, "Debug: Got cap %s\n", capname);
 173                if (!strcmp(capname, "fetch"))
 174                        data->fetch = 1;
 175                else if (!strcmp(capname, "option"))
 176                        data->option = 1;
 177                else if (!strcmp(capname, "push"))
 178                        data->push = 1;
 179                else if (!strcmp(capname, "import"))
 180                        data->import = 1;
 181                else if (!strcmp(capname, "export"))
 182                        data->export = 1;
 183                else if (!data->refspecs && !prefixcmp(capname, "refspec ")) {
 184                        ALLOC_GROW(refspecs,
 185                                   refspec_nr + 1,
 186                                   refspec_alloc);
 187                        refspecs[refspec_nr++] = xstrdup(capname + strlen("refspec "));
 188                } else if (!strcmp(capname, "connect")) {
 189                        data->connect = 1;
 190                } else if (!prefixcmp(capname, "export-marks ")) {
 191                        struct strbuf arg = STRBUF_INIT;
 192                        strbuf_addstr(&arg, "--export-marks=");
 193                        strbuf_addstr(&arg, capname + strlen("export-marks "));
 194                        data->export_marks = strbuf_detach(&arg, NULL);
 195                } else if (!prefixcmp(capname, "import-marks")) {
 196                        struct strbuf arg = STRBUF_INIT;
 197                        strbuf_addstr(&arg, "--import-marks=");
 198                        strbuf_addstr(&arg, capname + strlen("import-marks "));
 199                        data->import_marks = strbuf_detach(&arg, NULL);
 200                } else if (mandatory) {
 201                        die("Unknown mandatory capability %s. This remote "
 202                            "helper probably needs newer version of Git.",
 203                            capname);
 204                }
 205        }
 206        if (refspecs) {
 207                int i;
 208                data->refspec_nr = refspec_nr;
 209                data->refspecs = parse_fetch_refspec(refspec_nr, refspecs);
 210                for (i = 0; i < refspec_nr; i++) {
 211                        free((char *)refspecs[i]);
 212                }
 213                free(refspecs);
 214        }
 215        strbuf_release(&buf);
 216        if (debug)
 217                fprintf(stderr, "Debug: Capabilities complete.\n");
 218        return data->helper;
 219}
 220
 221static int disconnect_helper(struct transport *transport)
 222{
 223        struct helper_data *data = transport->data;
 224        int res = 0;
 225
 226        if (data->helper) {
 227                if (debug)
 228                        fprintf(stderr, "Debug: Disconnecting.\n");
 229                if (!data->no_disconnect_req) {
 230                        /*
 231                         * Ignore write errors; there's nothing we can do,
 232                         * since we're about to close the pipe anyway. And the
 233                         * most likely error is EPIPE due to the helper dying
 234                         * to report an error itself.
 235                         */
 236                        sigchain_push(SIGPIPE, SIG_IGN);
 237                        xwrite(data->helper->in, "\n", 1);
 238                        sigchain_pop(SIGPIPE);
 239                }
 240                close(data->helper->in);
 241                close(data->helper->out);
 242                fclose(data->out);
 243                res = finish_command(data->helper);
 244                free((char *)data->helper->argv[0]);
 245                free(data->helper->argv);
 246                free(data->helper);
 247                data->helper = NULL;
 248        }
 249        return res;
 250}
 251
 252static const char *unsupported_options[] = {
 253        TRANS_OPT_UPLOADPACK,
 254        TRANS_OPT_RECEIVEPACK,
 255        TRANS_OPT_THIN,
 256        TRANS_OPT_KEEP
 257        };
 258static const char *boolean_options[] = {
 259        TRANS_OPT_THIN,
 260        TRANS_OPT_KEEP,
 261        TRANS_OPT_FOLLOWTAGS
 262        };
 263
 264static int set_helper_option(struct transport *transport,
 265                          const char *name, const char *value)
 266{
 267        struct helper_data *data = transport->data;
 268        struct strbuf buf = STRBUF_INIT;
 269        int i, ret, is_bool = 0;
 270
 271        get_helper(transport);
 272
 273        if (!data->option)
 274                return 1;
 275
 276        for (i = 0; i < ARRAY_SIZE(unsupported_options); i++) {
 277                if (!strcmp(name, unsupported_options[i]))
 278                        return 1;
 279        }
 280
 281        for (i = 0; i < ARRAY_SIZE(boolean_options); i++) {
 282                if (!strcmp(name, boolean_options[i])) {
 283                        is_bool = 1;
 284                        break;
 285                }
 286        }
 287
 288        strbuf_addf(&buf, "option %s ", name);
 289        if (is_bool)
 290                strbuf_addstr(&buf, value ? "true" : "false");
 291        else
 292                quote_c_style(value, &buf, NULL, 0);
 293        strbuf_addch(&buf, '\n');
 294
 295        xchgline(data, &buf);
 296
 297        if (!strcmp(buf.buf, "ok"))
 298                ret = 0;
 299        else if (!prefixcmp(buf.buf, "error")) {
 300                ret = -1;
 301        } else if (!strcmp(buf.buf, "unsupported"))
 302                ret = 1;
 303        else {
 304                warning("%s unexpectedly said: '%s'", data->name, buf.buf);
 305                ret = 1;
 306        }
 307        strbuf_release(&buf);
 308        return ret;
 309}
 310
 311static void standard_options(struct transport *t)
 312{
 313        char buf[16];
 314        int n;
 315        int v = t->verbose;
 316
 317        set_helper_option(t, "progress", t->progress ? "true" : "false");
 318
 319        n = snprintf(buf, sizeof(buf), "%d", v + 1);
 320        if (n >= sizeof(buf))
 321                die("impossibly large verbosity value");
 322        set_helper_option(t, "verbosity", buf);
 323}
 324
 325static int release_helper(struct transport *transport)
 326{
 327        int res = 0;
 328        struct helper_data *data = transport->data;
 329        free_refspec(data->refspec_nr, data->refspecs);
 330        data->refspecs = NULL;
 331        res = disconnect_helper(transport);
 332        free(transport->data);
 333        return res;
 334}
 335
 336static int fetch_with_fetch(struct transport *transport,
 337                            int nr_heads, struct ref **to_fetch)
 338{
 339        struct helper_data *data = transport->data;
 340        int i;
 341        struct strbuf buf = STRBUF_INIT;
 342
 343        standard_options(transport);
 344
 345        for (i = 0; i < nr_heads; i++) {
 346                const struct ref *posn = to_fetch[i];
 347                if (posn->status & REF_STATUS_UPTODATE)
 348                        continue;
 349
 350                strbuf_addf(&buf, "fetch %s %s\n",
 351                            sha1_to_hex(posn->old_sha1), posn->name);
 352        }
 353
 354        strbuf_addch(&buf, '\n');
 355        sendline(data, &buf);
 356
 357        while (1) {
 358                recvline(data, &buf);
 359
 360                if (!prefixcmp(buf.buf, "lock ")) {
 361                        const char *name = buf.buf + 5;
 362                        if (transport->pack_lockfile)
 363                                warning("%s also locked %s", data->name, name);
 364                        else
 365                                transport->pack_lockfile = xstrdup(name);
 366                }
 367                else if (!buf.len)
 368                        break;
 369                else
 370                        warning("%s unexpectedly said: '%s'", data->name, buf.buf);
 371        }
 372        strbuf_release(&buf);
 373        return 0;
 374}
 375
 376static int get_importer(struct transport *transport, struct child_process *fastimport)
 377{
 378        struct child_process *helper = get_helper(transport);
 379        memset(fastimport, 0, sizeof(*fastimport));
 380        fastimport->in = helper->out;
 381        fastimport->argv = xcalloc(5, sizeof(*fastimport->argv));
 382        fastimport->argv[0] = "fast-import";
 383        fastimport->argv[1] = "--quiet";
 384
 385        fastimport->git_cmd = 1;
 386        return start_command(fastimport);
 387}
 388
 389static int get_exporter(struct transport *transport,
 390                        struct child_process *fastexport,
 391                        struct string_list *revlist_args)
 392{
 393        struct helper_data *data = transport->data;
 394        struct child_process *helper = get_helper(transport);
 395        int argc = 0, i;
 396        memset(fastexport, 0, sizeof(*fastexport));
 397
 398        /* we need to duplicate helper->in because we want to use it after
 399         * fastexport is done with it. */
 400        fastexport->out = dup(helper->in);
 401        fastexport->argv = xcalloc(5 + revlist_args->nr, sizeof(*fastexport->argv));
 402        fastexport->argv[argc++] = "fast-export";
 403        fastexport->argv[argc++] = "--use-done-feature";
 404        if (data->export_marks)
 405                fastexport->argv[argc++] = data->export_marks;
 406        if (data->import_marks)
 407                fastexport->argv[argc++] = data->import_marks;
 408
 409        for (i = 0; i < revlist_args->nr; i++)
 410                fastexport->argv[argc++] = revlist_args->items[i].string;
 411
 412        fastexport->git_cmd = 1;
 413        return start_command(fastexport);
 414}
 415
 416static int fetch_with_import(struct transport *transport,
 417                             int nr_heads, struct ref **to_fetch)
 418{
 419        struct child_process fastimport;
 420        struct helper_data *data = transport->data;
 421        int i;
 422        struct ref *posn;
 423        struct strbuf buf = STRBUF_INIT;
 424
 425        get_helper(transport);
 426
 427        if (get_importer(transport, &fastimport))
 428                die("Couldn't run fast-import");
 429
 430        for (i = 0; i < nr_heads; i++) {
 431                posn = to_fetch[i];
 432                if (posn->status & REF_STATUS_UPTODATE)
 433                        continue;
 434
 435                strbuf_addf(&buf, "import %s\n", posn->name);
 436                sendline(data, &buf);
 437                strbuf_reset(&buf);
 438        }
 439
 440        write_constant(data->helper->in, "\n");
 441
 442        if (finish_command(&fastimport))
 443                die("Error while running fast-import");
 444        free(fastimport.argv);
 445        fastimport.argv = NULL;
 446
 447        /*
 448         * The fast-import stream of a remote helper that advertises
 449         * the "refspec" capability writes to the refs named after the
 450         * right hand side of the first refspec matching each ref we
 451         * were fetching.
 452         *
 453         * (If no "refspec" capability was specified, for historical
 454         * reasons we default to *:*.)
 455         *
 456         * Store the result in to_fetch[i].old_sha1.  Callers such
 457         * as "git fetch" can use the value to write feedback to the
 458         * terminal, populate FETCH_HEAD, and determine what new value
 459         * should be written to peer_ref if the update is a
 460         * fast-forward or this is a forced update.
 461         */
 462        for (i = 0; i < nr_heads; i++) {
 463                char *private;
 464                posn = to_fetch[i];
 465                if (posn->status & REF_STATUS_UPTODATE)
 466                        continue;
 467                if (data->refspecs)
 468                        private = apply_refspecs(data->refspecs, data->refspec_nr, posn->name);
 469                else
 470                        private = xstrdup(posn->name);
 471                if (private) {
 472                        read_ref(private, posn->old_sha1);
 473                        free(private);
 474                }
 475        }
 476        strbuf_release(&buf);
 477        return 0;
 478}
 479
 480static int process_connect_service(struct transport *transport,
 481                                   const char *name, const char *exec)
 482{
 483        struct helper_data *data = transport->data;
 484        struct strbuf cmdbuf = STRBUF_INIT;
 485        struct child_process *helper;
 486        int r, duped, ret = 0;
 487        FILE *input;
 488
 489        helper = get_helper(transport);
 490
 491        /*
 492         * Yes, dup the pipe another time, as we need unbuffered version
 493         * of input pipe as FILE*. fclose() closes the underlying fd and
 494         * stream buffering only can be changed before first I/O operation
 495         * on it.
 496         */
 497        duped = dup(helper->out);
 498        if (duped < 0)
 499                die_errno("Can't dup helper output fd");
 500        input = xfdopen(duped, "r");
 501        setvbuf(input, NULL, _IONBF, 0);
 502
 503        /*
 504         * Handle --upload-pack and friends. This is fire and forget...
 505         * just warn if it fails.
 506         */
 507        if (strcmp(name, exec)) {
 508                r = set_helper_option(transport, "servpath", exec);
 509                if (r > 0)
 510                        warning("Setting remote service path not supported by protocol.");
 511                else if (r < 0)
 512                        warning("Invalid remote service path.");
 513        }
 514
 515        if (data->connect)
 516                strbuf_addf(&cmdbuf, "connect %s\n", name);
 517        else
 518                goto exit;
 519
 520        sendline(data, &cmdbuf);
 521        recvline_fh(input, &cmdbuf);
 522        if (!strcmp(cmdbuf.buf, "")) {
 523                data->no_disconnect_req = 1;
 524                if (debug)
 525                        fprintf(stderr, "Debug: Smart transport connection "
 526                                "ready.\n");
 527                ret = 1;
 528        } else if (!strcmp(cmdbuf.buf, "fallback")) {
 529                if (debug)
 530                        fprintf(stderr, "Debug: Falling back to dumb "
 531                                "transport.\n");
 532        } else
 533                die("Unknown response to connect: %s",
 534                        cmdbuf.buf);
 535
 536exit:
 537        fclose(input);
 538        return ret;
 539}
 540
 541static int process_connect(struct transport *transport,
 542                                     int for_push)
 543{
 544        struct helper_data *data = transport->data;
 545        const char *name;
 546        const char *exec;
 547
 548        name = for_push ? "git-receive-pack" : "git-upload-pack";
 549        if (for_push)
 550                exec = data->transport_options.receivepack;
 551        else
 552                exec = data->transport_options.uploadpack;
 553
 554        return process_connect_service(transport, name, exec);
 555}
 556
 557static int connect_helper(struct transport *transport, const char *name,
 558                   const char *exec, int fd[2])
 559{
 560        struct helper_data *data = transport->data;
 561
 562        /* Get_helper so connect is inited. */
 563        get_helper(transport);
 564        if (!data->connect)
 565                die("Operation not supported by protocol.");
 566
 567        if (!process_connect_service(transport, name, exec))
 568                die("Can't connect to subservice %s.", name);
 569
 570        fd[0] = data->helper->out;
 571        fd[1] = data->helper->in;
 572        return 0;
 573}
 574
 575static int fetch(struct transport *transport,
 576                 int nr_heads, struct ref **to_fetch)
 577{
 578        struct helper_data *data = transport->data;
 579        int i, count;
 580
 581        if (process_connect(transport, 0)) {
 582                do_take_over(transport);
 583                return transport->fetch(transport, nr_heads, to_fetch);
 584        }
 585
 586        count = 0;
 587        for (i = 0; i < nr_heads; i++)
 588                if (!(to_fetch[i]->status & REF_STATUS_UPTODATE))
 589                        count++;
 590
 591        if (!count)
 592                return 0;
 593
 594        if (data->fetch)
 595                return fetch_with_fetch(transport, nr_heads, to_fetch);
 596
 597        if (data->import)
 598                return fetch_with_import(transport, nr_heads, to_fetch);
 599
 600        return -1;
 601}
 602
 603static void push_update_ref_status(struct strbuf *buf,
 604                                   struct ref **ref,
 605                                   struct ref *remote_refs)
 606{
 607        char *refname, *msg;
 608        int status;
 609
 610        if (!prefixcmp(buf->buf, "ok ")) {
 611                status = REF_STATUS_OK;
 612                refname = buf->buf + 3;
 613        } else if (!prefixcmp(buf->buf, "error ")) {
 614                status = REF_STATUS_REMOTE_REJECT;
 615                refname = buf->buf + 6;
 616        } else
 617                die("expected ok/error, helper said '%s'", buf->buf);
 618
 619        msg = strchr(refname, ' ');
 620        if (msg) {
 621                struct strbuf msg_buf = STRBUF_INIT;
 622                const char *end;
 623
 624                *msg++ = '\0';
 625                if (!unquote_c_style(&msg_buf, msg, &end))
 626                        msg = strbuf_detach(&msg_buf, NULL);
 627                else
 628                        msg = xstrdup(msg);
 629                strbuf_release(&msg_buf);
 630
 631                if (!strcmp(msg, "no match")) {
 632                        status = REF_STATUS_NONE;
 633                        free(msg);
 634                        msg = NULL;
 635                }
 636                else if (!strcmp(msg, "up to date")) {
 637                        status = REF_STATUS_UPTODATE;
 638                        free(msg);
 639                        msg = NULL;
 640                }
 641                else if (!strcmp(msg, "non-fast forward")) {
 642                        status = REF_STATUS_REJECT_NONFASTFORWARD;
 643                        free(msg);
 644                        msg = NULL;
 645                }
 646        }
 647
 648        if (*ref)
 649                *ref = find_ref_by_name(*ref, refname);
 650        if (!*ref)
 651                *ref = find_ref_by_name(remote_refs, refname);
 652        if (!*ref) {
 653                warning("helper reported unexpected status of %s", refname);
 654                return;
 655        }
 656
 657        if ((*ref)->status != REF_STATUS_NONE) {
 658                /*
 659                 * Earlier, the ref was marked not to be pushed, so ignore the ref
 660                 * status reported by the remote helper if the latter is 'no match'.
 661                 */
 662                if (status == REF_STATUS_NONE)
 663                        return;
 664        }
 665
 666        (*ref)->status = status;
 667        (*ref)->remote_status = msg;
 668}
 669
 670static void push_update_refs_status(struct helper_data *data,
 671                                    struct ref *remote_refs)
 672{
 673        struct strbuf buf = STRBUF_INIT;
 674        struct ref *ref = remote_refs;
 675        for (;;) {
 676                recvline(data, &buf);
 677                if (!buf.len)
 678                        break;
 679
 680                push_update_ref_status(&buf, &ref, remote_refs);
 681        }
 682        strbuf_release(&buf);
 683}
 684
 685static int push_refs_with_push(struct transport *transport,
 686                struct ref *remote_refs, int flags)
 687{
 688        int force_all = flags & TRANSPORT_PUSH_FORCE;
 689        int mirror = flags & TRANSPORT_PUSH_MIRROR;
 690        struct helper_data *data = transport->data;
 691        struct strbuf buf = STRBUF_INIT;
 692        struct ref *ref;
 693
 694        get_helper(transport);
 695        if (!data->push)
 696                return 1;
 697
 698        for (ref = remote_refs; ref; ref = ref->next) {
 699                if (!ref->peer_ref && !mirror)
 700                        continue;
 701
 702                /* Check for statuses set by set_ref_status_for_push() */
 703                switch (ref->status) {
 704                case REF_STATUS_REJECT_NONFASTFORWARD:
 705                case REF_STATUS_UPTODATE:
 706                        continue;
 707                default:
 708                        ; /* do nothing */
 709                }
 710
 711                if (force_all)
 712                        ref->force = 1;
 713
 714                strbuf_addstr(&buf, "push ");
 715                if (!ref->deletion) {
 716                        if (ref->force)
 717                                strbuf_addch(&buf, '+');
 718                        if (ref->peer_ref)
 719                                strbuf_addstr(&buf, ref->peer_ref->name);
 720                        else
 721                                strbuf_addstr(&buf, sha1_to_hex(ref->new_sha1));
 722                }
 723                strbuf_addch(&buf, ':');
 724                strbuf_addstr(&buf, ref->name);
 725                strbuf_addch(&buf, '\n');
 726        }
 727        if (buf.len == 0)
 728                return 0;
 729
 730        standard_options(transport);
 731
 732        if (flags & TRANSPORT_PUSH_DRY_RUN) {
 733                if (set_helper_option(transport, "dry-run", "true") != 0)
 734                        die("helper %s does not support dry-run", data->name);
 735        }
 736
 737        strbuf_addch(&buf, '\n');
 738        sendline(data, &buf);
 739        strbuf_release(&buf);
 740
 741        push_update_refs_status(data, remote_refs);
 742        return 0;
 743}
 744
 745static int push_refs_with_export(struct transport *transport,
 746                struct ref *remote_refs, int flags)
 747{
 748        struct ref *ref;
 749        struct child_process *helper, exporter;
 750        struct helper_data *data = transport->data;
 751        struct string_list revlist_args = STRING_LIST_INIT_NODUP;
 752        struct strbuf buf = STRBUF_INIT;
 753
 754        helper = get_helper(transport);
 755
 756        write_constant(helper->in, "export\n");
 757
 758        strbuf_reset(&buf);
 759
 760        for (ref = remote_refs; ref; ref = ref->next) {
 761                char *private;
 762                unsigned char sha1[20];
 763
 764                if (!data->refspecs)
 765                        continue;
 766                private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
 767                if (private && !get_sha1(private, sha1)) {
 768                        strbuf_addf(&buf, "^%s", private);
 769                        string_list_append(&revlist_args, strbuf_detach(&buf, NULL));
 770                }
 771                free(private);
 772
 773                if (ref->deletion) {
 774                        die("remote-helpers do not support ref deletion");
 775                }
 776
 777                if (ref->peer_ref)
 778                        string_list_append(&revlist_args, ref->peer_ref->name);
 779
 780        }
 781
 782        if (get_exporter(transport, &exporter, &revlist_args))
 783                die("Couldn't run fast-export");
 784
 785        if (finish_command(&exporter))
 786                die("Error while running fast-export");
 787        push_update_refs_status(data, remote_refs);
 788        return 0;
 789}
 790
 791static int push_refs(struct transport *transport,
 792                struct ref *remote_refs, int flags)
 793{
 794        struct helper_data *data = transport->data;
 795
 796        if (process_connect(transport, 1)) {
 797                do_take_over(transport);
 798                return transport->push_refs(transport, remote_refs, flags);
 799        }
 800
 801        if (!remote_refs) {
 802                fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
 803                        "Perhaps you should specify a branch such as 'master'.\n");
 804                return 0;
 805        }
 806
 807        if (data->push)
 808                return push_refs_with_push(transport, remote_refs, flags);
 809
 810        if (data->export)
 811                return push_refs_with_export(transport, remote_refs, flags);
 812
 813        return -1;
 814}
 815
 816
 817static int has_attribute(const char *attrs, const char *attr) {
 818        int len;
 819        if (!attrs)
 820                return 0;
 821
 822        len = strlen(attr);
 823        for (;;) {
 824                const char *space = strchrnul(attrs, ' ');
 825                if (len == space - attrs && !strncmp(attrs, attr, len))
 826                        return 1;
 827                if (!*space)
 828                        return 0;
 829                attrs = space + 1;
 830        }
 831}
 832
 833static struct ref *get_refs_list(struct transport *transport, int for_push)
 834{
 835        struct helper_data *data = transport->data;
 836        struct child_process *helper;
 837        struct ref *ret = NULL;
 838        struct ref **tail = &ret;
 839        struct ref *posn;
 840        struct strbuf buf = STRBUF_INIT;
 841
 842        helper = get_helper(transport);
 843
 844        if (process_connect(transport, for_push)) {
 845                do_take_over(transport);
 846                return transport->get_refs_list(transport, for_push);
 847        }
 848
 849        if (data->push && for_push)
 850                write_str_in_full(helper->in, "list for-push\n");
 851        else
 852                write_str_in_full(helper->in, "list\n");
 853
 854        while (1) {
 855                char *eov, *eon;
 856                recvline(data, &buf);
 857
 858                if (!*buf.buf)
 859                        break;
 860
 861                eov = strchr(buf.buf, ' ');
 862                if (!eov)
 863                        die("Malformed response in ref list: %s", buf.buf);
 864                eon = strchr(eov + 1, ' ');
 865                *eov = '\0';
 866                if (eon)
 867                        *eon = '\0';
 868                *tail = alloc_ref(eov + 1);
 869                if (buf.buf[0] == '@')
 870                        (*tail)->symref = xstrdup(buf.buf + 1);
 871                else if (buf.buf[0] != '?')
 872                        get_sha1_hex(buf.buf, (*tail)->old_sha1);
 873                if (eon) {
 874                        if (has_attribute(eon + 1, "unchanged")) {
 875                                (*tail)->status |= REF_STATUS_UPTODATE;
 876                                read_ref((*tail)->name, (*tail)->old_sha1);
 877                        }
 878                }
 879                tail = &((*tail)->next);
 880        }
 881        if (debug)
 882                fprintf(stderr, "Debug: Read ref listing.\n");
 883        strbuf_release(&buf);
 884
 885        for (posn = ret; posn; posn = posn->next)
 886                resolve_remote_symref(posn, ret);
 887
 888        return ret;
 889}
 890
 891int transport_helper_init(struct transport *transport, const char *name)
 892{
 893        struct helper_data *data = xcalloc(sizeof(*data), 1);
 894        data->name = name;
 895
 896        if (getenv("GIT_TRANSPORT_HELPER_DEBUG"))
 897                debug = 1;
 898
 899        transport->data = data;
 900        transport->set_option = set_helper_option;
 901        transport->get_refs_list = get_refs_list;
 902        transport->fetch = fetch;
 903        transport->push_refs = push_refs;
 904        transport->disconnect = release_helper;
 905        transport->connect = connect_helper;
 906        transport->smart_options = &(data->transport_options);
 907        return 0;
 908}
 909
 910/*
 911 * Linux pipes can buffer 65536 bytes at once (and most platforms can
 912 * buffer less), so attempt reads and writes with up to that size.
 913 */
 914#define BUFFERSIZE 65536
 915/* This should be enough to hold debugging message. */
 916#define PBUFFERSIZE 8192
 917
 918/* Print bidirectional transfer loop debug message. */
 919static void transfer_debug(const char *fmt, ...)
 920{
 921        va_list args;
 922        char msgbuf[PBUFFERSIZE];
 923        static int debug_enabled = -1;
 924
 925        if (debug_enabled < 0)
 926                debug_enabled = getenv("GIT_TRANSLOOP_DEBUG") ? 1 : 0;
 927        if (!debug_enabled)
 928                return;
 929
 930        va_start(args, fmt);
 931        vsnprintf(msgbuf, PBUFFERSIZE, fmt, args);
 932        va_end(args);
 933        fprintf(stderr, "Transfer loop debugging: %s\n", msgbuf);
 934}
 935
 936/* Stream state: More data may be coming in this direction. */
 937#define SSTATE_TRANSFERING 0
 938/*
 939 * Stream state: No more data coming in this direction, flushing rest of
 940 * data.
 941 */
 942#define SSTATE_FLUSHING 1
 943/* Stream state: Transfer in this direction finished. */
 944#define SSTATE_FINISHED 2
 945
 946#define STATE_NEEDS_READING(state) ((state) <= SSTATE_TRANSFERING)
 947#define STATE_NEEDS_WRITING(state) ((state) <= SSTATE_FLUSHING)
 948#define STATE_NEEDS_CLOSING(state) ((state) == SSTATE_FLUSHING)
 949
 950/* Unidirectional transfer. */
 951struct unidirectional_transfer {
 952        /* Source */
 953        int src;
 954        /* Destination */
 955        int dest;
 956        /* Is source socket? */
 957        int src_is_sock;
 958        /* Is destination socket? */
 959        int dest_is_sock;
 960        /* Transfer state (TRANSFERING/FLUSHING/FINISHED) */
 961        int state;
 962        /* Buffer. */
 963        char buf[BUFFERSIZE];
 964        /* Buffer used. */
 965        size_t bufuse;
 966        /* Name of source. */
 967        const char *src_name;
 968        /* Name of destination. */
 969        const char *dest_name;
 970};
 971
 972/* Closes the target (for writing) if transfer has finished. */
 973static void udt_close_if_finished(struct unidirectional_transfer *t)
 974{
 975        if (STATE_NEEDS_CLOSING(t->state) && !t->bufuse) {
 976                t->state = SSTATE_FINISHED;
 977                if (t->dest_is_sock)
 978                        shutdown(t->dest, SHUT_WR);
 979                else
 980                        close(t->dest);
 981                transfer_debug("Closed %s.", t->dest_name);
 982        }
 983}
 984
 985/*
 986 * Tries to read read data from source into buffer. If buffer is full,
 987 * no data is read. Returns 0 on success, -1 on error.
 988 */
 989static int udt_do_read(struct unidirectional_transfer *t)
 990{
 991        ssize_t bytes;
 992
 993        if (t->bufuse == BUFFERSIZE)
 994                return 0;       /* No space for more. */
 995
 996        transfer_debug("%s is readable", t->src_name);
 997        bytes = read(t->src, t->buf + t->bufuse, BUFFERSIZE - t->bufuse);
 998        if (bytes < 0 && errno != EWOULDBLOCK && errno != EAGAIN &&
 999                errno != EINTR) {
1000                error("read(%s) failed: %s", t->src_name, strerror(errno));
1001                return -1;
1002        } else if (bytes == 0) {
1003                transfer_debug("%s EOF (with %i bytes in buffer)",
1004                        t->src_name, t->bufuse);
1005                t->state = SSTATE_FLUSHING;
1006        } else if (bytes > 0) {
1007                t->bufuse += bytes;
1008                transfer_debug("Read %i bytes from %s (buffer now at %i)",
1009                        (int)bytes, t->src_name, (int)t->bufuse);
1010        }
1011        return 0;
1012}
1013
1014/* Tries to write data from buffer into destination. If buffer is empty,
1015 * no data is written. Returns 0 on success, -1 on error.
1016 */
1017static int udt_do_write(struct unidirectional_transfer *t)
1018{
1019        ssize_t bytes;
1020
1021        if (t->bufuse == 0)
1022                return 0;       /* Nothing to write. */
1023
1024        transfer_debug("%s is writable", t->dest_name);
1025        bytes = write(t->dest, t->buf, t->bufuse);
1026        if (bytes < 0 && errno != EWOULDBLOCK && errno != EAGAIN &&
1027                errno != EINTR) {
1028                error("write(%s) failed: %s", t->dest_name, strerror(errno));
1029                return -1;
1030        } else if (bytes > 0) {
1031                t->bufuse -= bytes;
1032                if (t->bufuse)
1033                        memmove(t->buf, t->buf + bytes, t->bufuse);
1034                transfer_debug("Wrote %i bytes to %s (buffer now at %i)",
1035                        (int)bytes, t->dest_name, (int)t->bufuse);
1036        }
1037        return 0;
1038}
1039
1040
1041/* State of bidirectional transfer loop. */
1042struct bidirectional_transfer_state {
1043        /* Direction from program to git. */
1044        struct unidirectional_transfer ptg;
1045        /* Direction from git to program. */
1046        struct unidirectional_transfer gtp;
1047};
1048
1049static void *udt_copy_task_routine(void *udt)
1050{
1051        struct unidirectional_transfer *t = (struct unidirectional_transfer *)udt;
1052        while (t->state != SSTATE_FINISHED) {
1053                if (STATE_NEEDS_READING(t->state))
1054                        if (udt_do_read(t))
1055                                return NULL;
1056                if (STATE_NEEDS_WRITING(t->state))
1057                        if (udt_do_write(t))
1058                                return NULL;
1059                if (STATE_NEEDS_CLOSING(t->state))
1060                        udt_close_if_finished(t);
1061        }
1062        return udt;     /* Just some non-NULL value. */
1063}
1064
1065#ifndef NO_PTHREADS
1066
1067/*
1068 * Join thread, with apporiate errors on failure. Name is name for the
1069 * thread (for error messages). Returns 0 on success, 1 on failure.
1070 */
1071static int tloop_join(pthread_t thread, const char *name)
1072{
1073        int err;
1074        void *tret;
1075        err = pthread_join(thread, &tret);
1076        if (!tret) {
1077                error("%s thread failed", name);
1078                return 1;
1079        }
1080        if (err) {
1081                error("%s thread failed to join: %s", name, strerror(err));
1082                return 1;
1083        }
1084        return 0;
1085}
1086
1087/*
1088 * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1089 * -1 on failure.
1090 */
1091static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1092{
1093        pthread_t gtp_thread;
1094        pthread_t ptg_thread;
1095        int err;
1096        int ret = 0;
1097        err = pthread_create(&gtp_thread, NULL, udt_copy_task_routine,
1098                &s->gtp);
1099        if (err)
1100                die("Can't start thread for copying data: %s", strerror(err));
1101        err = pthread_create(&ptg_thread, NULL, udt_copy_task_routine,
1102                &s->ptg);
1103        if (err)
1104                die("Can't start thread for copying data: %s", strerror(err));
1105
1106        ret |= tloop_join(gtp_thread, "Git to program copy");
1107        ret |= tloop_join(ptg_thread, "Program to git copy");
1108        return ret;
1109}
1110#else
1111
1112/* Close the source and target (for writing) for transfer. */
1113static void udt_kill_transfer(struct unidirectional_transfer *t)
1114{
1115        t->state = SSTATE_FINISHED;
1116        /*
1117         * Socket read end left open isn't a disaster if nobody
1118         * attempts to read from it (mingw compat headers do not
1119         * have SHUT_RD)...
1120         *
1121         * We can't fully close the socket since otherwise gtp
1122         * task would first close the socket it sends data to
1123         * while closing the ptg file descriptors.
1124         */
1125        if (!t->src_is_sock)
1126                close(t->src);
1127        if (t->dest_is_sock)
1128                shutdown(t->dest, SHUT_WR);
1129        else
1130                close(t->dest);
1131}
1132
1133/*
1134 * Join process, with apporiate errors on failure. Name is name for the
1135 * process (for error messages). Returns 0 on success, 1 on failure.
1136 */
1137static int tloop_join(pid_t pid, const char *name)
1138{
1139        int tret;
1140        if (waitpid(pid, &tret, 0) < 0) {
1141                error("%s process failed to wait: %s", name, strerror(errno));
1142                return 1;
1143        }
1144        if (!WIFEXITED(tret) || WEXITSTATUS(tret)) {
1145                error("%s process failed", name);
1146                return 1;
1147        }
1148        return 0;
1149}
1150
1151/*
1152 * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1153 * -1 on failure.
1154 */
1155static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1156{
1157        pid_t pid1, pid2;
1158        int ret = 0;
1159
1160        /* Fork thread #1: git to program. */
1161        pid1 = fork();
1162        if (pid1 < 0)
1163                die_errno("Can't start thread for copying data");
1164        else if (pid1 == 0) {
1165                udt_kill_transfer(&s->ptg);
1166                exit(udt_copy_task_routine(&s->gtp) ? 0 : 1);
1167        }
1168
1169        /* Fork thread #2: program to git. */
1170        pid2 = fork();
1171        if (pid2 < 0)
1172                die_errno("Can't start thread for copying data");
1173        else if (pid2 == 0) {
1174                udt_kill_transfer(&s->gtp);
1175                exit(udt_copy_task_routine(&s->ptg) ? 0 : 1);
1176        }
1177
1178        /*
1179         * Close both streams in parent as to not interfere with
1180         * end of file detection and wait for both tasks to finish.
1181         */
1182        udt_kill_transfer(&s->gtp);
1183        udt_kill_transfer(&s->ptg);
1184        ret |= tloop_join(pid1, "Git to program copy");
1185        ret |= tloop_join(pid2, "Program to git copy");
1186        return ret;
1187}
1188#endif
1189
1190/*
1191 * Copies data from stdin to output and from input to stdout simultaneously.
1192 * Additionally filtering through given filter. If filter is NULL, uses
1193 * identity filter.
1194 */
1195int bidirectional_transfer_loop(int input, int output)
1196{
1197        struct bidirectional_transfer_state state;
1198
1199        /* Fill the state fields. */
1200        state.ptg.src = input;
1201        state.ptg.dest = 1;
1202        state.ptg.src_is_sock = (input == output);
1203        state.ptg.dest_is_sock = 0;
1204        state.ptg.state = SSTATE_TRANSFERING;
1205        state.ptg.bufuse = 0;
1206        state.ptg.src_name = "remote input";
1207        state.ptg.dest_name = "stdout";
1208
1209        state.gtp.src = 0;
1210        state.gtp.dest = output;
1211        state.gtp.src_is_sock = 0;
1212        state.gtp.dest_is_sock = (input == output);
1213        state.gtp.state = SSTATE_TRANSFERING;
1214        state.gtp.bufuse = 0;
1215        state.gtp.src_name = "stdin";
1216        state.gtp.dest_name = "remote output";
1217
1218        return tloop_spawnwait_tasks(&state);
1219}