transport-helper.con commit t0002: add test for enter_repo(), non-strict mode (3104120)
   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 "remote.h"
   9#include "string-list.h"
  10#include "thread-utils.h"
  11#include "sigchain.h"
  12#include "argv-array.h"
  13#include "refs.h"
  14
  15static int debug;
  16
  17struct helper_data {
  18        const char *name;
  19        struct child_process *helper;
  20        FILE *out;
  21        unsigned fetch : 1,
  22                import : 1,
  23                bidi_import : 1,
  24                export : 1,
  25                option : 1,
  26                push : 1,
  27                connect : 1,
  28                signed_tags : 1,
  29                check_connectivity : 1,
  30                no_disconnect_req : 1,
  31                no_private_update : 1;
  32        char *export_marks;
  33        char *import_marks;
  34        /* These go from remote name (as in "list") to private name */
  35        struct refspec *refspecs;
  36        int refspec_nr;
  37        /* Transport options for fetch-pack/send-pack (should one of
  38         * those be invoked).
  39         */
  40        struct git_transport_options transport_options;
  41};
  42
  43static void sendline(struct helper_data *helper, struct strbuf *buffer)
  44{
  45        if (debug)
  46                fprintf(stderr, "Debug: Remote helper: -> %s", buffer->buf);
  47        if (write_in_full(helper->helper->in, buffer->buf, buffer->len)
  48                != buffer->len)
  49                die_errno("Full write to remote helper failed");
  50}
  51
  52static int recvline_fh(FILE *helper, struct strbuf *buffer, const char *name)
  53{
  54        strbuf_reset(buffer);
  55        if (debug)
  56                fprintf(stderr, "Debug: Remote helper: Waiting...\n");
  57        if (strbuf_getline(buffer, helper, '\n') == EOF) {
  58                if (debug)
  59                        fprintf(stderr, "Debug: Remote helper quit.\n");
  60                return 1;
  61        }
  62
  63        if (debug)
  64                fprintf(stderr, "Debug: Remote helper: <- %s\n", buffer->buf);
  65        return 0;
  66}
  67
  68static int recvline(struct helper_data *helper, struct strbuf *buffer)
  69{
  70        return recvline_fh(helper->out, buffer, helper->name);
  71}
  72
  73static void write_constant(int fd, const char *str)
  74{
  75        if (debug)
  76                fprintf(stderr, "Debug: Remote helper: -> %s", str);
  77        if (write_in_full(fd, str, strlen(str)) != strlen(str))
  78                die_errno("Full write to remote helper failed");
  79}
  80
  81static const char *remove_ext_force(const char *url)
  82{
  83        if (url) {
  84                const char *colon = strchr(url, ':');
  85                if (colon && colon[1] == ':')
  86                        return colon + 2;
  87        }
  88        return url;
  89}
  90
  91static void do_take_over(struct transport *transport)
  92{
  93        struct helper_data *data;
  94        data = (struct helper_data *)transport->data;
  95        transport_take_over(transport, data->helper);
  96        fclose(data->out);
  97        free(data);
  98}
  99
 100static void standard_options(struct transport *t);
 101
 102static struct child_process *get_helper(struct transport *transport)
 103{
 104        struct helper_data *data = transport->data;
 105        struct strbuf buf = STRBUF_INIT;
 106        struct child_process *helper;
 107        const char **refspecs = NULL;
 108        int refspec_nr = 0;
 109        int refspec_alloc = 0;
 110        int duped;
 111        int code;
 112
 113        if (data->helper)
 114                return data->helper;
 115
 116        helper = xmalloc(sizeof(*helper));
 117        child_process_init(helper);
 118        helper->in = -1;
 119        helper->out = -1;
 120        helper->err = 0;
 121        argv_array_pushf(&helper->args, "git-remote-%s", data->name);
 122        argv_array_push(&helper->args, transport->remote->name);
 123        argv_array_push(&helper->args, remove_ext_force(transport->url));
 124        helper->git_cmd = 0;
 125        helper->silent_exec_failure = 1;
 126
 127        argv_array_pushf(&helper->env_array, "%s=%s", GIT_DIR_ENVIRONMENT,
 128                         get_git_dir());
 129
 130        code = start_command(helper);
 131        if (code < 0 && errno == ENOENT)
 132                die("Unable to find remote helper for '%s'", data->name);
 133        else if (code != 0)
 134                exit(code);
 135
 136        data->helper = helper;
 137        data->no_disconnect_req = 0;
 138
 139        /*
 140         * Open the output as FILE* so strbuf_getline() can be used.
 141         * Do this with duped fd because fclose() will close the fd,
 142         * and stuff like taking over will require the fd to remain.
 143         */
 144        duped = dup(helper->out);
 145        if (duped < 0)
 146                die_errno("Can't dup helper output fd");
 147        data->out = xfdopen(duped, "r");
 148
 149        write_constant(helper->in, "capabilities\n");
 150
 151        while (1) {
 152                const char *capname, *arg;
 153                int mandatory = 0;
 154                if (recvline(data, &buf))
 155                        exit(128);
 156
 157                if (!*buf.buf)
 158                        break;
 159
 160                if (*buf.buf == '*') {
 161                        capname = buf.buf + 1;
 162                        mandatory = 1;
 163                } else
 164                        capname = buf.buf;
 165
 166                if (debug)
 167                        fprintf(stderr, "Debug: Got cap %s\n", capname);
 168                if (!strcmp(capname, "fetch"))
 169                        data->fetch = 1;
 170                else if (!strcmp(capname, "option"))
 171                        data->option = 1;
 172                else if (!strcmp(capname, "push"))
 173                        data->push = 1;
 174                else if (!strcmp(capname, "import"))
 175                        data->import = 1;
 176                else if (!strcmp(capname, "bidi-import"))
 177                        data->bidi_import = 1;
 178                else if (!strcmp(capname, "export"))
 179                        data->export = 1;
 180                else if (!strcmp(capname, "check-connectivity"))
 181                        data->check_connectivity = 1;
 182                else if (!data->refspecs && skip_prefix(capname, "refspec ", &arg)) {
 183                        ALLOC_GROW(refspecs,
 184                                   refspec_nr + 1,
 185                                   refspec_alloc);
 186                        refspecs[refspec_nr++] = xstrdup(arg);
 187                } else if (!strcmp(capname, "connect")) {
 188                        data->connect = 1;
 189                } else if (!strcmp(capname, "signed-tags")) {
 190                        data->signed_tags = 1;
 191                } else if (skip_prefix(capname, "export-marks ", &arg)) {
 192                        data->export_marks = xstrdup(arg);
 193                } else if (skip_prefix(capname, "import-marks ", &arg)) {
 194                        data->import_marks = xstrdup(arg);
 195                } else if (starts_with(capname, "no-private-update")) {
 196                        data->no_private_update = 1;
 197                } else if (mandatory) {
 198                        die("Unknown mandatory capability %s. This remote "
 199                            "helper probably needs newer version of Git.",
 200                            capname);
 201                }
 202        }
 203        if (refspecs) {
 204                int i;
 205                data->refspec_nr = refspec_nr;
 206                data->refspecs = parse_fetch_refspec(refspec_nr, refspecs);
 207                for (i = 0; i < refspec_nr; i++)
 208                        free((char *)refspecs[i]);
 209                free(refspecs);
 210        } else if (data->import || data->bidi_import || data->export) {
 211                warning("This remote helper should implement refspec capability.");
 212        }
 213        strbuf_release(&buf);
 214        if (debug)
 215                fprintf(stderr, "Debug: Capabilities complete.\n");
 216        standard_options(transport);
 217        return data->helper;
 218}
 219
 220static int disconnect_helper(struct transport *transport)
 221{
 222        struct helper_data *data = transport->data;
 223        int res = 0;
 224
 225        if (data->helper) {
 226                if (debug)
 227                        fprintf(stderr, "Debug: Disconnecting.\n");
 228                if (!data->no_disconnect_req) {
 229                        /*
 230                         * Ignore write errors; there's nothing we can do,
 231                         * since we're about to close the pipe anyway. And the
 232                         * most likely error is EPIPE due to the helper dying
 233                         * to report an error itself.
 234                         */
 235                        sigchain_push(SIGPIPE, SIG_IGN);
 236                        xwrite(data->helper->in, "\n", 1);
 237                        sigchain_pop(SIGPIPE);
 238                }
 239                close(data->helper->in);
 240                close(data->helper->out);
 241                fclose(data->out);
 242                res = finish_command(data->helper);
 243                free(data->helper);
 244                data->helper = NULL;
 245        }
 246        return res;
 247}
 248
 249static const char *unsupported_options[] = {
 250        TRANS_OPT_UPLOADPACK,
 251        TRANS_OPT_RECEIVEPACK,
 252        TRANS_OPT_THIN,
 253        TRANS_OPT_KEEP
 254        };
 255
 256static const char *boolean_options[] = {
 257        TRANS_OPT_THIN,
 258        TRANS_OPT_KEEP,
 259        TRANS_OPT_FOLLOWTAGS,
 260        };
 261
 262static int set_helper_option(struct transport *transport,
 263                          const char *name, const char *value)
 264{
 265        struct helper_data *data = transport->data;
 266        struct strbuf buf = STRBUF_INIT;
 267        int i, ret, is_bool = 0;
 268
 269        get_helper(transport);
 270
 271        if (!data->option)
 272                return 1;
 273
 274        for (i = 0; i < ARRAY_SIZE(unsupported_options); i++) {
 275                if (!strcmp(name, unsupported_options[i]))
 276                        return 1;
 277        }
 278
 279        for (i = 0; i < ARRAY_SIZE(boolean_options); i++) {
 280                if (!strcmp(name, boolean_options[i])) {
 281                        is_bool = 1;
 282                        break;
 283                }
 284        }
 285
 286        strbuf_addf(&buf, "option %s ", name);
 287        if (is_bool)
 288                strbuf_addstr(&buf, value ? "true" : "false");
 289        else
 290                quote_c_style(value, &buf, NULL, 0);
 291        strbuf_addch(&buf, '\n');
 292
 293        sendline(data, &buf);
 294        if (recvline(data, &buf))
 295                exit(128);
 296
 297        if (!strcmp(buf.buf, "ok"))
 298                ret = 0;
 299        else if (starts_with(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        for (i = 0; i < nr_heads; i++) {
 344                const struct ref *posn = to_fetch[i];
 345                if (posn->status & REF_STATUS_UPTODATE)
 346                        continue;
 347
 348                strbuf_addf(&buf, "fetch %s %s\n",
 349                            sha1_to_hex(posn->old_sha1),
 350                            posn->symref ? posn->symref : posn->name);
 351        }
 352
 353        strbuf_addch(&buf, '\n');
 354        sendline(data, &buf);
 355
 356        while (1) {
 357                if (recvline(data, &buf))
 358                        exit(128);
 359
 360                if (starts_with(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 (data->check_connectivity &&
 368                         data->transport_options.check_self_contained_and_connected &&
 369                         !strcmp(buf.buf, "connectivity-ok"))
 370                        data->transport_options.self_contained_and_connected = 1;
 371                else if (!buf.len)
 372                        break;
 373                else
 374                        warning("%s unexpectedly said: '%s'", data->name, buf.buf);
 375        }
 376        strbuf_release(&buf);
 377        return 0;
 378}
 379
 380static int get_importer(struct transport *transport, struct child_process *fastimport)
 381{
 382        struct child_process *helper = get_helper(transport);
 383        struct helper_data *data = transport->data;
 384        int cat_blob_fd, code;
 385        child_process_init(fastimport);
 386        fastimport->in = helper->out;
 387        argv_array_push(&fastimport->args, "fast-import");
 388        argv_array_push(&fastimport->args, debug ? "--stats" : "--quiet");
 389
 390        if (data->bidi_import) {
 391                cat_blob_fd = xdup(helper->in);
 392                argv_array_pushf(&fastimport->args, "--cat-blob-fd=%d", cat_blob_fd);
 393        }
 394        fastimport->git_cmd = 1;
 395
 396        code = start_command(fastimport);
 397        return code;
 398}
 399
 400static int get_exporter(struct transport *transport,
 401                        struct child_process *fastexport,
 402                        struct string_list *revlist_args)
 403{
 404        struct helper_data *data = transport->data;
 405        struct child_process *helper = get_helper(transport);
 406        int i;
 407
 408        child_process_init(fastexport);
 409
 410        /* we need to duplicate helper->in because we want to use it after
 411         * fastexport is done with it. */
 412        fastexport->out = dup(helper->in);
 413        argv_array_push(&fastexport->args, "fast-export");
 414        argv_array_push(&fastexport->args, "--use-done-feature");
 415        argv_array_push(&fastexport->args, data->signed_tags ?
 416                "--signed-tags=verbatim" : "--signed-tags=warn-strip");
 417        if (data->export_marks)
 418                argv_array_pushf(&fastexport->args, "--export-marks=%s.tmp", data->export_marks);
 419        if (data->import_marks)
 420                argv_array_pushf(&fastexport->args, "--import-marks=%s", data->import_marks);
 421
 422        for (i = 0; i < revlist_args->nr; i++)
 423                argv_array_push(&fastexport->args, revlist_args->items[i].string);
 424
 425        fastexport->git_cmd = 1;
 426        return start_command(fastexport);
 427}
 428
 429static int fetch_with_import(struct transport *transport,
 430                             int nr_heads, struct ref **to_fetch)
 431{
 432        struct child_process fastimport;
 433        struct helper_data *data = transport->data;
 434        int i;
 435        struct ref *posn;
 436        struct strbuf buf = STRBUF_INIT;
 437
 438        get_helper(transport);
 439
 440        if (get_importer(transport, &fastimport))
 441                die("Couldn't run fast-import");
 442
 443        for (i = 0; i < nr_heads; i++) {
 444                posn = to_fetch[i];
 445                if (posn->status & REF_STATUS_UPTODATE)
 446                        continue;
 447
 448                strbuf_addf(&buf, "import %s\n",
 449                            posn->symref ? posn->symref : posn->name);
 450                sendline(data, &buf);
 451                strbuf_reset(&buf);
 452        }
 453
 454        write_constant(data->helper->in, "\n");
 455        /*
 456         * remote-helpers that advertise the bidi-import capability are required to
 457         * buffer the complete batch of import commands until this newline before
 458         * sending data to fast-import.
 459         * These helpers read back data from fast-import on their stdin, which could
 460         * be mixed with import commands, otherwise.
 461         */
 462
 463        if (finish_command(&fastimport))
 464                die("Error while running fast-import");
 465
 466        /*
 467         * The fast-import stream of a remote helper that advertises
 468         * the "refspec" capability writes to the refs named after the
 469         * right hand side of the first refspec matching each ref we
 470         * were fetching.
 471         *
 472         * (If no "refspec" capability was specified, for historical
 473         * reasons we default to the equivalent of *:*.)
 474         *
 475         * Store the result in to_fetch[i].old_sha1.  Callers such
 476         * as "git fetch" can use the value to write feedback to the
 477         * terminal, populate FETCH_HEAD, and determine what new value
 478         * should be written to peer_ref if the update is a
 479         * fast-forward or this is a forced update.
 480         */
 481        for (i = 0; i < nr_heads; i++) {
 482                char *private, *name;
 483                posn = to_fetch[i];
 484                if (posn->status & REF_STATUS_UPTODATE)
 485                        continue;
 486                name = posn->symref ? posn->symref : posn->name;
 487                if (data->refspecs)
 488                        private = apply_refspecs(data->refspecs, data->refspec_nr, name);
 489                else
 490                        private = xstrdup(name);
 491                if (private) {
 492                        if (read_ref(private, posn->old_sha1) < 0)
 493                                die("Could not read ref %s", private);
 494                        free(private);
 495                }
 496        }
 497        strbuf_release(&buf);
 498        return 0;
 499}
 500
 501static int process_connect_service(struct transport *transport,
 502                                   const char *name, const char *exec)
 503{
 504        struct helper_data *data = transport->data;
 505        struct strbuf cmdbuf = STRBUF_INIT;
 506        struct child_process *helper;
 507        int r, duped, ret = 0;
 508        FILE *input;
 509
 510        helper = get_helper(transport);
 511
 512        /*
 513         * Yes, dup the pipe another time, as we need unbuffered version
 514         * of input pipe as FILE*. fclose() closes the underlying fd and
 515         * stream buffering only can be changed before first I/O operation
 516         * on it.
 517         */
 518        duped = dup(helper->out);
 519        if (duped < 0)
 520                die_errno("Can't dup helper output fd");
 521        input = xfdopen(duped, "r");
 522        setvbuf(input, NULL, _IONBF, 0);
 523
 524        /*
 525         * Handle --upload-pack and friends. This is fire and forget...
 526         * just warn if it fails.
 527         */
 528        if (strcmp(name, exec)) {
 529                r = set_helper_option(transport, "servpath", exec);
 530                if (r > 0)
 531                        warning("Setting remote service path not supported by protocol.");
 532                else if (r < 0)
 533                        warning("Invalid remote service path.");
 534        }
 535
 536        if (data->connect)
 537                strbuf_addf(&cmdbuf, "connect %s\n", name);
 538        else
 539                goto exit;
 540
 541        sendline(data, &cmdbuf);
 542        if (recvline_fh(input, &cmdbuf, name))
 543                exit(128);
 544
 545        if (!strcmp(cmdbuf.buf, "")) {
 546                data->no_disconnect_req = 1;
 547                if (debug)
 548                        fprintf(stderr, "Debug: Smart transport connection "
 549                                "ready.\n");
 550                ret = 1;
 551        } else if (!strcmp(cmdbuf.buf, "fallback")) {
 552                if (debug)
 553                        fprintf(stderr, "Debug: Falling back to dumb "
 554                                "transport.\n");
 555        } else
 556                die("Unknown response to connect: %s",
 557                        cmdbuf.buf);
 558
 559exit:
 560        fclose(input);
 561        return ret;
 562}
 563
 564static int process_connect(struct transport *transport,
 565                                     int for_push)
 566{
 567        struct helper_data *data = transport->data;
 568        const char *name;
 569        const char *exec;
 570
 571        name = for_push ? "git-receive-pack" : "git-upload-pack";
 572        if (for_push)
 573                exec = data->transport_options.receivepack;
 574        else
 575                exec = data->transport_options.uploadpack;
 576
 577        return process_connect_service(transport, name, exec);
 578}
 579
 580static int connect_helper(struct transport *transport, const char *name,
 581                   const char *exec, int fd[2])
 582{
 583        struct helper_data *data = transport->data;
 584
 585        /* Get_helper so connect is inited. */
 586        get_helper(transport);
 587        if (!data->connect)
 588                die("Operation not supported by protocol.");
 589
 590        if (!process_connect_service(transport, name, exec))
 591                die("Can't connect to subservice %s.", name);
 592
 593        fd[0] = data->helper->out;
 594        fd[1] = data->helper->in;
 595        return 0;
 596}
 597
 598static int fetch(struct transport *transport,
 599                 int nr_heads, struct ref **to_fetch)
 600{
 601        struct helper_data *data = transport->data;
 602        int i, count;
 603
 604        if (process_connect(transport, 0)) {
 605                do_take_over(transport);
 606                return transport->fetch(transport, nr_heads, to_fetch);
 607        }
 608
 609        count = 0;
 610        for (i = 0; i < nr_heads; i++)
 611                if (!(to_fetch[i]->status & REF_STATUS_UPTODATE))
 612                        count++;
 613
 614        if (!count)
 615                return 0;
 616
 617        if (data->check_connectivity &&
 618            data->transport_options.check_self_contained_and_connected)
 619                set_helper_option(transport, "check-connectivity", "true");
 620
 621        if (transport->cloning)
 622                set_helper_option(transport, "cloning", "true");
 623
 624        if (data->transport_options.update_shallow)
 625                set_helper_option(transport, "update-shallow", "true");
 626
 627        if (data->fetch)
 628                return fetch_with_fetch(transport, nr_heads, to_fetch);
 629
 630        if (data->import)
 631                return fetch_with_import(transport, nr_heads, to_fetch);
 632
 633        return -1;
 634}
 635
 636static int push_update_ref_status(struct strbuf *buf,
 637                                   struct ref **ref,
 638                                   struct ref *remote_refs)
 639{
 640        char *refname, *msg;
 641        int status, forced = 0;
 642
 643        if (starts_with(buf->buf, "ok ")) {
 644                status = REF_STATUS_OK;
 645                refname = buf->buf + 3;
 646        } else if (starts_with(buf->buf, "error ")) {
 647                status = REF_STATUS_REMOTE_REJECT;
 648                refname = buf->buf + 6;
 649        } else
 650                die("expected ok/error, helper said '%s'", buf->buf);
 651
 652        msg = strchr(refname, ' ');
 653        if (msg) {
 654                struct strbuf msg_buf = STRBUF_INIT;
 655                const char *end;
 656
 657                *msg++ = '\0';
 658                if (!unquote_c_style(&msg_buf, msg, &end))
 659                        msg = strbuf_detach(&msg_buf, NULL);
 660                else
 661                        msg = xstrdup(msg);
 662                strbuf_release(&msg_buf);
 663
 664                if (!strcmp(msg, "no match")) {
 665                        status = REF_STATUS_NONE;
 666                        free(msg);
 667                        msg = NULL;
 668                }
 669                else if (!strcmp(msg, "up to date")) {
 670                        status = REF_STATUS_UPTODATE;
 671                        free(msg);
 672                        msg = NULL;
 673                }
 674                else if (!strcmp(msg, "non-fast forward")) {
 675                        status = REF_STATUS_REJECT_NONFASTFORWARD;
 676                        free(msg);
 677                        msg = NULL;
 678                }
 679                else if (!strcmp(msg, "already exists")) {
 680                        status = REF_STATUS_REJECT_ALREADY_EXISTS;
 681                        free(msg);
 682                        msg = NULL;
 683                }
 684                else if (!strcmp(msg, "fetch first")) {
 685                        status = REF_STATUS_REJECT_FETCH_FIRST;
 686                        free(msg);
 687                        msg = NULL;
 688                }
 689                else if (!strcmp(msg, "needs force")) {
 690                        status = REF_STATUS_REJECT_NEEDS_FORCE;
 691                        free(msg);
 692                        msg = NULL;
 693                }
 694                else if (!strcmp(msg, "stale info")) {
 695                        status = REF_STATUS_REJECT_STALE;
 696                        free(msg);
 697                        msg = NULL;
 698                }
 699                else if (!strcmp(msg, "forced update")) {
 700                        forced = 1;
 701                        free(msg);
 702                        msg = NULL;
 703                }
 704        }
 705
 706        if (*ref)
 707                *ref = find_ref_by_name(*ref, refname);
 708        if (!*ref)
 709                *ref = find_ref_by_name(remote_refs, refname);
 710        if (!*ref) {
 711                warning("helper reported unexpected status of %s", refname);
 712                return 1;
 713        }
 714
 715        if ((*ref)->status != REF_STATUS_NONE) {
 716                /*
 717                 * Earlier, the ref was marked not to be pushed, so ignore the ref
 718                 * status reported by the remote helper if the latter is 'no match'.
 719                 */
 720                if (status == REF_STATUS_NONE)
 721                        return 1;
 722        }
 723
 724        (*ref)->status = status;
 725        (*ref)->forced_update |= forced;
 726        (*ref)->remote_status = msg;
 727        return !(status == REF_STATUS_OK);
 728}
 729
 730static int push_update_refs_status(struct helper_data *data,
 731                                    struct ref *remote_refs,
 732                                    int flags)
 733{
 734        struct strbuf buf = STRBUF_INIT;
 735        struct ref *ref = remote_refs;
 736        int ret = 0;
 737
 738        for (;;) {
 739                char *private;
 740
 741                if (recvline(data, &buf)) {
 742                        ret = 1;
 743                        break;
 744                }
 745
 746                if (!buf.len)
 747                        break;
 748
 749                if (push_update_ref_status(&buf, &ref, remote_refs))
 750                        continue;
 751
 752                if (flags & TRANSPORT_PUSH_DRY_RUN || !data->refspecs || data->no_private_update)
 753                        continue;
 754
 755                /* propagate back the update to the remote namespace */
 756                private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
 757                if (!private)
 758                        continue;
 759                update_ref("update by helper", private, ref->new_sha1, NULL, 0, 0);
 760                free(private);
 761        }
 762        strbuf_release(&buf);
 763        return ret;
 764}
 765
 766static void set_common_push_options(struct transport *transport,
 767                                   const char *name, int flags)
 768{
 769        if (flags & TRANSPORT_PUSH_DRY_RUN) {
 770                if (set_helper_option(transport, "dry-run", "true") != 0)
 771                        die("helper %s does not support dry-run", name);
 772        } else if (flags & TRANSPORT_PUSH_CERT_ALWAYS) {
 773                if (set_helper_option(transport, TRANS_OPT_PUSH_CERT, "true") != 0)
 774                        die("helper %s does not support --signed", name);
 775        } else if (flags & TRANSPORT_PUSH_CERT_IF_ASKED) {
 776                if (set_helper_option(transport, TRANS_OPT_PUSH_CERT, "if-asked") != 0)
 777                        die("helper %s does not support --signed=if-asked", name);
 778        }
 779}
 780
 781static int push_refs_with_push(struct transport *transport,
 782                               struct ref *remote_refs, int flags)
 783{
 784        int force_all = flags & TRANSPORT_PUSH_FORCE;
 785        int mirror = flags & TRANSPORT_PUSH_MIRROR;
 786        struct helper_data *data = transport->data;
 787        struct strbuf buf = STRBUF_INIT;
 788        struct ref *ref;
 789        struct string_list cas_options = STRING_LIST_INIT_DUP;
 790        struct string_list_item *cas_option;
 791
 792        get_helper(transport);
 793        if (!data->push)
 794                return 1;
 795
 796        for (ref = remote_refs; ref; ref = ref->next) {
 797                if (!ref->peer_ref && !mirror)
 798                        continue;
 799
 800                /* Check for statuses set by set_ref_status_for_push() */
 801                switch (ref->status) {
 802                case REF_STATUS_REJECT_NONFASTFORWARD:
 803                case REF_STATUS_REJECT_STALE:
 804                case REF_STATUS_REJECT_ALREADY_EXISTS:
 805                case REF_STATUS_UPTODATE:
 806                        continue;
 807                default:
 808                        ; /* do nothing */
 809                }
 810
 811                if (force_all)
 812                        ref->force = 1;
 813
 814                strbuf_addstr(&buf, "push ");
 815                if (!ref->deletion) {
 816                        if (ref->force)
 817                                strbuf_addch(&buf, '+');
 818                        if (ref->peer_ref)
 819                                strbuf_addstr(&buf, ref->peer_ref->name);
 820                        else
 821                                strbuf_addstr(&buf, sha1_to_hex(ref->new_sha1));
 822                }
 823                strbuf_addch(&buf, ':');
 824                strbuf_addstr(&buf, ref->name);
 825                strbuf_addch(&buf, '\n');
 826
 827                /*
 828                 * The "--force-with-lease" options without explicit
 829                 * values to expect have already been expanded into
 830                 * the ref->old_sha1_expect[] field; we can ignore
 831                 * transport->smart_options->cas altogether and instead
 832                 * can enumerate them from the refs.
 833                 */
 834                if (ref->expect_old_sha1) {
 835                        struct strbuf cas = STRBUF_INIT;
 836                        strbuf_addf(&cas, "%s:%s",
 837                                    ref->name, sha1_to_hex(ref->old_sha1_expect));
 838                        string_list_append(&cas_options, strbuf_detach(&cas, NULL));
 839                }
 840        }
 841        if (buf.len == 0) {
 842                string_list_clear(&cas_options, 0);
 843                return 0;
 844        }
 845
 846        for_each_string_list_item(cas_option, &cas_options)
 847                set_helper_option(transport, "cas", cas_option->string);
 848        set_common_push_options(transport, data->name, flags);
 849
 850        strbuf_addch(&buf, '\n');
 851        sendline(data, &buf);
 852        strbuf_release(&buf);
 853
 854        return push_update_refs_status(data, remote_refs, flags);
 855}
 856
 857static int push_refs_with_export(struct transport *transport,
 858                struct ref *remote_refs, int flags)
 859{
 860        struct ref *ref;
 861        struct child_process *helper, exporter;
 862        struct helper_data *data = transport->data;
 863        struct string_list revlist_args = STRING_LIST_INIT_DUP;
 864        struct strbuf buf = STRBUF_INIT;
 865
 866        if (!data->refspecs)
 867                die("remote-helper doesn't support push; refspec needed");
 868
 869        set_common_push_options(transport, data->name, flags);
 870        if (flags & TRANSPORT_PUSH_FORCE) {
 871                if (set_helper_option(transport, "force", "true") != 0)
 872                        warning("helper %s does not support 'force'", data->name);
 873        }
 874
 875        helper = get_helper(transport);
 876
 877        write_constant(helper->in, "export\n");
 878
 879        for (ref = remote_refs; ref; ref = ref->next) {
 880                char *private;
 881                unsigned char sha1[20];
 882
 883                private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
 884                if (private && !get_sha1(private, sha1)) {
 885                        strbuf_addf(&buf, "^%s", private);
 886                        string_list_append(&revlist_args, strbuf_detach(&buf, NULL));
 887                        hashcpy(ref->old_sha1, sha1);
 888                }
 889                free(private);
 890
 891                if (ref->peer_ref) {
 892                        if (strcmp(ref->name, ref->peer_ref->name)) {
 893                                if (!ref->deletion) {
 894                                        const char *name;
 895                                        int flag;
 896
 897                                        /* Follow symbolic refs (mainly for HEAD). */
 898                                        name = resolve_ref_unsafe(
 899                                                 ref->peer_ref->name,
 900                                                 RESOLVE_REF_READING,
 901                                                 sha1, &flag);
 902                                        if (!name || !(flag & REF_ISSYMREF))
 903                                                name = ref->peer_ref->name;
 904
 905                                        strbuf_addf(&buf, "%s:%s", name, ref->name);
 906                                } else
 907                                        strbuf_addf(&buf, ":%s", ref->name);
 908
 909                                string_list_append(&revlist_args, "--refspec");
 910                                string_list_append(&revlist_args, buf.buf);
 911                                strbuf_release(&buf);
 912                        }
 913                        if (!ref->deletion)
 914                                string_list_append(&revlist_args, ref->peer_ref->name);
 915                }
 916        }
 917
 918        if (get_exporter(transport, &exporter, &revlist_args))
 919                die("Couldn't run fast-export");
 920
 921        string_list_clear(&revlist_args, 1);
 922
 923        if (finish_command(&exporter))
 924                die("Error while running fast-export");
 925        if (push_update_refs_status(data, remote_refs, flags))
 926                return 1;
 927
 928        if (data->export_marks) {
 929                strbuf_addf(&buf, "%s.tmp", data->export_marks);
 930                rename(buf.buf, data->export_marks);
 931                strbuf_release(&buf);
 932        }
 933
 934        return 0;
 935}
 936
 937static int push_refs(struct transport *transport,
 938                struct ref *remote_refs, int flags)
 939{
 940        struct helper_data *data = transport->data;
 941
 942        if (process_connect(transport, 1)) {
 943                do_take_over(transport);
 944                return transport->push_refs(transport, remote_refs, flags);
 945        }
 946
 947        if (!remote_refs) {
 948                fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
 949                        "Perhaps you should specify a branch such as 'master'.\n");
 950                return 0;
 951        }
 952
 953        if (data->push)
 954                return push_refs_with_push(transport, remote_refs, flags);
 955
 956        if (data->export)
 957                return push_refs_with_export(transport, remote_refs, flags);
 958
 959        return -1;
 960}
 961
 962
 963static int has_attribute(const char *attrs, const char *attr) {
 964        int len;
 965        if (!attrs)
 966                return 0;
 967
 968        len = strlen(attr);
 969        for (;;) {
 970                const char *space = strchrnul(attrs, ' ');
 971                if (len == space - attrs && !strncmp(attrs, attr, len))
 972                        return 1;
 973                if (!*space)
 974                        return 0;
 975                attrs = space + 1;
 976        }
 977}
 978
 979static struct ref *get_refs_list(struct transport *transport, int for_push)
 980{
 981        struct helper_data *data = transport->data;
 982        struct child_process *helper;
 983        struct ref *ret = NULL;
 984        struct ref **tail = &ret;
 985        struct ref *posn;
 986        struct strbuf buf = STRBUF_INIT;
 987
 988        helper = get_helper(transport);
 989
 990        if (process_connect(transport, for_push)) {
 991                do_take_over(transport);
 992                return transport->get_refs_list(transport, for_push);
 993        }
 994
 995        if (data->push && for_push)
 996                write_str_in_full(helper->in, "list for-push\n");
 997        else
 998                write_str_in_full(helper->in, "list\n");
 999
1000        while (1) {
1001                char *eov, *eon;
1002                if (recvline(data, &buf))
1003                        exit(128);
1004
1005                if (!*buf.buf)
1006                        break;
1007
1008                eov = strchr(buf.buf, ' ');
1009                if (!eov)
1010                        die("Malformed response in ref list: %s", buf.buf);
1011                eon = strchr(eov + 1, ' ');
1012                *eov = '\0';
1013                if (eon)
1014                        *eon = '\0';
1015                *tail = alloc_ref(eov + 1);
1016                if (buf.buf[0] == '@')
1017                        (*tail)->symref = xstrdup(buf.buf + 1);
1018                else if (buf.buf[0] != '?')
1019                        get_sha1_hex(buf.buf, (*tail)->old_sha1);
1020                if (eon) {
1021                        if (has_attribute(eon + 1, "unchanged")) {
1022                                (*tail)->status |= REF_STATUS_UPTODATE;
1023                                if (read_ref((*tail)->name,
1024                                             (*tail)->old_sha1) < 0)
1025                                        die(N_("Could not read ref %s"),
1026                                            (*tail)->name);
1027                        }
1028                }
1029                tail = &((*tail)->next);
1030        }
1031        if (debug)
1032                fprintf(stderr, "Debug: Read ref listing.\n");
1033        strbuf_release(&buf);
1034
1035        for (posn = ret; posn; posn = posn->next)
1036                resolve_remote_symref(posn, ret);
1037
1038        return ret;
1039}
1040
1041int transport_helper_init(struct transport *transport, const char *name)
1042{
1043        struct helper_data *data = xcalloc(1, sizeof(*data));
1044        data->name = name;
1045
1046        if (getenv("GIT_TRANSPORT_HELPER_DEBUG"))
1047                debug = 1;
1048
1049        transport->data = data;
1050        transport->set_option = set_helper_option;
1051        transport->get_refs_list = get_refs_list;
1052        transport->fetch = fetch;
1053        transport->push_refs = push_refs;
1054        transport->disconnect = release_helper;
1055        transport->connect = connect_helper;
1056        transport->smart_options = &(data->transport_options);
1057        return 0;
1058}
1059
1060/*
1061 * Linux pipes can buffer 65536 bytes at once (and most platforms can
1062 * buffer less), so attempt reads and writes with up to that size.
1063 */
1064#define BUFFERSIZE 65536
1065/* This should be enough to hold debugging message. */
1066#define PBUFFERSIZE 8192
1067
1068/* Print bidirectional transfer loop debug message. */
1069__attribute__((format (printf, 1, 2)))
1070static void transfer_debug(const char *fmt, ...)
1071{
1072        va_list args;
1073        char msgbuf[PBUFFERSIZE];
1074        static int debug_enabled = -1;
1075
1076        if (debug_enabled < 0)
1077                debug_enabled = getenv("GIT_TRANSLOOP_DEBUG") ? 1 : 0;
1078        if (!debug_enabled)
1079                return;
1080
1081        va_start(args, fmt);
1082        vsnprintf(msgbuf, PBUFFERSIZE, fmt, args);
1083        va_end(args);
1084        fprintf(stderr, "Transfer loop debugging: %s\n", msgbuf);
1085}
1086
1087/* Stream state: More data may be coming in this direction. */
1088#define SSTATE_TRANSFERING 0
1089/*
1090 * Stream state: No more data coming in this direction, flushing rest of
1091 * data.
1092 */
1093#define SSTATE_FLUSHING 1
1094/* Stream state: Transfer in this direction finished. */
1095#define SSTATE_FINISHED 2
1096
1097#define STATE_NEEDS_READING(state) ((state) <= SSTATE_TRANSFERING)
1098#define STATE_NEEDS_WRITING(state) ((state) <= SSTATE_FLUSHING)
1099#define STATE_NEEDS_CLOSING(state) ((state) == SSTATE_FLUSHING)
1100
1101/* Unidirectional transfer. */
1102struct unidirectional_transfer {
1103        /* Source */
1104        int src;
1105        /* Destination */
1106        int dest;
1107        /* Is source socket? */
1108        int src_is_sock;
1109        /* Is destination socket? */
1110        int dest_is_sock;
1111        /* Transfer state (TRANSFERRING/FLUSHING/FINISHED) */
1112        int state;
1113        /* Buffer. */
1114        char buf[BUFFERSIZE];
1115        /* Buffer used. */
1116        size_t bufuse;
1117        /* Name of source. */
1118        const char *src_name;
1119        /* Name of destination. */
1120        const char *dest_name;
1121};
1122
1123/* Closes the target (for writing) if transfer has finished. */
1124static void udt_close_if_finished(struct unidirectional_transfer *t)
1125{
1126        if (STATE_NEEDS_CLOSING(t->state) && !t->bufuse) {
1127                t->state = SSTATE_FINISHED;
1128                if (t->dest_is_sock)
1129                        shutdown(t->dest, SHUT_WR);
1130                else
1131                        close(t->dest);
1132                transfer_debug("Closed %s.", t->dest_name);
1133        }
1134}
1135
1136/*
1137 * Tries to read read data from source into buffer. If buffer is full,
1138 * no data is read. Returns 0 on success, -1 on error.
1139 */
1140static int udt_do_read(struct unidirectional_transfer *t)
1141{
1142        ssize_t bytes;
1143
1144        if (t->bufuse == BUFFERSIZE)
1145                return 0;       /* No space for more. */
1146
1147        transfer_debug("%s is readable", t->src_name);
1148        bytes = read(t->src, t->buf + t->bufuse, BUFFERSIZE - t->bufuse);
1149        if (bytes < 0 && errno != EWOULDBLOCK && errno != EAGAIN &&
1150                errno != EINTR) {
1151                error("read(%s) failed: %s", t->src_name, strerror(errno));
1152                return -1;
1153        } else if (bytes == 0) {
1154                transfer_debug("%s EOF (with %i bytes in buffer)",
1155                        t->src_name, (int)t->bufuse);
1156                t->state = SSTATE_FLUSHING;
1157        } else if (bytes > 0) {
1158                t->bufuse += bytes;
1159                transfer_debug("Read %i bytes from %s (buffer now at %i)",
1160                        (int)bytes, t->src_name, (int)t->bufuse);
1161        }
1162        return 0;
1163}
1164
1165/* Tries to write data from buffer into destination. If buffer is empty,
1166 * no data is written. Returns 0 on success, -1 on error.
1167 */
1168static int udt_do_write(struct unidirectional_transfer *t)
1169{
1170        ssize_t bytes;
1171
1172        if (t->bufuse == 0)
1173                return 0;       /* Nothing to write. */
1174
1175        transfer_debug("%s is writable", t->dest_name);
1176        bytes = xwrite(t->dest, t->buf, t->bufuse);
1177        if (bytes < 0 && errno != EWOULDBLOCK) {
1178                error("write(%s) failed: %s", t->dest_name, strerror(errno));
1179                return -1;
1180        } else if (bytes > 0) {
1181                t->bufuse -= bytes;
1182                if (t->bufuse)
1183                        memmove(t->buf, t->buf + bytes, t->bufuse);
1184                transfer_debug("Wrote %i bytes to %s (buffer now at %i)",
1185                        (int)bytes, t->dest_name, (int)t->bufuse);
1186        }
1187        return 0;
1188}
1189
1190
1191/* State of bidirectional transfer loop. */
1192struct bidirectional_transfer_state {
1193        /* Direction from program to git. */
1194        struct unidirectional_transfer ptg;
1195        /* Direction from git to program. */
1196        struct unidirectional_transfer gtp;
1197};
1198
1199static void *udt_copy_task_routine(void *udt)
1200{
1201        struct unidirectional_transfer *t = (struct unidirectional_transfer *)udt;
1202        while (t->state != SSTATE_FINISHED) {
1203                if (STATE_NEEDS_READING(t->state))
1204                        if (udt_do_read(t))
1205                                return NULL;
1206                if (STATE_NEEDS_WRITING(t->state))
1207                        if (udt_do_write(t))
1208                                return NULL;
1209                if (STATE_NEEDS_CLOSING(t->state))
1210                        udt_close_if_finished(t);
1211        }
1212        return udt;     /* Just some non-NULL value. */
1213}
1214
1215#ifndef NO_PTHREADS
1216
1217/*
1218 * Join thread, with appropriate errors on failure. Name is name for the
1219 * thread (for error messages). Returns 0 on success, 1 on failure.
1220 */
1221static int tloop_join(pthread_t thread, const char *name)
1222{
1223        int err;
1224        void *tret;
1225        err = pthread_join(thread, &tret);
1226        if (!tret) {
1227                error("%s thread failed", name);
1228                return 1;
1229        }
1230        if (err) {
1231                error("%s thread failed to join: %s", name, strerror(err));
1232                return 1;
1233        }
1234        return 0;
1235}
1236
1237/*
1238 * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1239 * -1 on failure.
1240 */
1241static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1242{
1243        pthread_t gtp_thread;
1244        pthread_t ptg_thread;
1245        int err;
1246        int ret = 0;
1247        err = pthread_create(&gtp_thread, NULL, udt_copy_task_routine,
1248                &s->gtp);
1249        if (err)
1250                die("Can't start thread for copying data: %s", strerror(err));
1251        err = pthread_create(&ptg_thread, NULL, udt_copy_task_routine,
1252                &s->ptg);
1253        if (err)
1254                die("Can't start thread for copying data: %s", strerror(err));
1255
1256        ret |= tloop_join(gtp_thread, "Git to program copy");
1257        ret |= tloop_join(ptg_thread, "Program to git copy");
1258        return ret;
1259}
1260#else
1261
1262/* Close the source and target (for writing) for transfer. */
1263static void udt_kill_transfer(struct unidirectional_transfer *t)
1264{
1265        t->state = SSTATE_FINISHED;
1266        /*
1267         * Socket read end left open isn't a disaster if nobody
1268         * attempts to read from it (mingw compat headers do not
1269         * have SHUT_RD)...
1270         *
1271         * We can't fully close the socket since otherwise gtp
1272         * task would first close the socket it sends data to
1273         * while closing the ptg file descriptors.
1274         */
1275        if (!t->src_is_sock)
1276                close(t->src);
1277        if (t->dest_is_sock)
1278                shutdown(t->dest, SHUT_WR);
1279        else
1280                close(t->dest);
1281}
1282
1283/*
1284 * Join process, with appropriate errors on failure. Name is name for the
1285 * process (for error messages). Returns 0 on success, 1 on failure.
1286 */
1287static int tloop_join(pid_t pid, const char *name)
1288{
1289        int tret;
1290        if (waitpid(pid, &tret, 0) < 0) {
1291                error("%s process failed to wait: %s", name, strerror(errno));
1292                return 1;
1293        }
1294        if (!WIFEXITED(tret) || WEXITSTATUS(tret)) {
1295                error("%s process failed", name);
1296                return 1;
1297        }
1298        return 0;
1299}
1300
1301/*
1302 * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1303 * -1 on failure.
1304 */
1305static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1306{
1307        pid_t pid1, pid2;
1308        int ret = 0;
1309
1310        /* Fork thread #1: git to program. */
1311        pid1 = fork();
1312        if (pid1 < 0)
1313                die_errno("Can't start thread for copying data");
1314        else if (pid1 == 0) {
1315                udt_kill_transfer(&s->ptg);
1316                exit(udt_copy_task_routine(&s->gtp) ? 0 : 1);
1317        }
1318
1319        /* Fork thread #2: program to git. */
1320        pid2 = fork();
1321        if (pid2 < 0)
1322                die_errno("Can't start thread for copying data");
1323        else if (pid2 == 0) {
1324                udt_kill_transfer(&s->gtp);
1325                exit(udt_copy_task_routine(&s->ptg) ? 0 : 1);
1326        }
1327
1328        /*
1329         * Close both streams in parent as to not interfere with
1330         * end of file detection and wait for both tasks to finish.
1331         */
1332        udt_kill_transfer(&s->gtp);
1333        udt_kill_transfer(&s->ptg);
1334        ret |= tloop_join(pid1, "Git to program copy");
1335        ret |= tloop_join(pid2, "Program to git copy");
1336        return ret;
1337}
1338#endif
1339
1340/*
1341 * Copies data from stdin to output and from input to stdout simultaneously.
1342 * Additionally filtering through given filter. If filter is NULL, uses
1343 * identity filter.
1344 */
1345int bidirectional_transfer_loop(int input, int output)
1346{
1347        struct bidirectional_transfer_state state;
1348
1349        /* Fill the state fields. */
1350        state.ptg.src = input;
1351        state.ptg.dest = 1;
1352        state.ptg.src_is_sock = (input == output);
1353        state.ptg.dest_is_sock = 0;
1354        state.ptg.state = SSTATE_TRANSFERING;
1355        state.ptg.bufuse = 0;
1356        state.ptg.src_name = "remote input";
1357        state.ptg.dest_name = "stdout";
1358
1359        state.gtp.src = 0;
1360        state.gtp.dest = output;
1361        state.gtp.src_is_sock = 0;
1362        state.gtp.dest_is_sock = (input == output);
1363        state.gtp.state = SSTATE_TRANSFERING;
1364        state.gtp.bufuse = 0;
1365        state.gtp.src_name = "stdin";
1366        state.gtp.dest_name = "remote output";
1367
1368        return tloop_spawnwait_tasks(&state);
1369}