transport-helper.con commit subtree: fix AsciiDoc list item continuation (e0a1f09)
   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#include "argv-array.h"
  14#include "refs.h"
  15
  16static int debug;
  17
  18struct helper_data {
  19        const char *name;
  20        struct child_process *helper;
  21        FILE *out;
  22        unsigned fetch : 1,
  23                import : 1,
  24                bidi_import : 1,
  25                export : 1,
  26                option : 1,
  27                push : 1,
  28                connect : 1,
  29                signed_tags : 1,
  30                check_connectivity : 1,
  31                no_disconnect_req : 1,
  32                no_private_update : 1;
  33        char *export_marks;
  34        char *import_marks;
  35        /* These go from remote name (as in "list") to private name */
  36        struct refspec *refspecs;
  37        int refspec_nr;
  38        /* Transport options for fetch-pack/send-pack (should one of
  39         * those be invoked).
  40         */
  41        struct git_transport_options transport_options;
  42};
  43
  44static void sendline(struct helper_data *helper, struct strbuf *buffer)
  45{
  46        if (debug)
  47                fprintf(stderr, "Debug: Remote helper: -> %s", buffer->buf);
  48        if (write_in_full(helper->helper->in, buffer->buf, buffer->len)
  49                != buffer->len)
  50                die_errno("Full write to remote helper failed");
  51}
  52
  53static int recvline_fh(FILE *helper, struct strbuf *buffer, const char *name)
  54{
  55        strbuf_reset(buffer);
  56        if (debug)
  57                fprintf(stderr, "Debug: Remote helper: Waiting...\n");
  58        if (strbuf_getline(buffer, helper, '\n') == EOF) {
  59                if (debug)
  60                        fprintf(stderr, "Debug: Remote helper quit.\n");
  61                return 1;
  62        }
  63
  64        if (debug)
  65                fprintf(stderr, "Debug: Remote helper: <- %s\n", buffer->buf);
  66        return 0;
  67}
  68
  69static int recvline(struct helper_data *helper, struct strbuf *buffer)
  70{
  71        return recvline_fh(helper->out, buffer, helper->name);
  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
 112        if (data->helper)
 113                return data->helper;
 114
 115        helper = xmalloc(sizeof(*helper));
 116        child_process_init(helper);
 117        helper->in = -1;
 118        helper->out = -1;
 119        helper->err = 0;
 120        argv_array_pushf(&helper->args, "git-remote-%s", data->name);
 121        argv_array_push(&helper->args, transport->remote->name);
 122        argv_array_push(&helper->args, remove_ext_force(transport->url));
 123        helper->git_cmd = 0;
 124        helper->silent_exec_failure = 1;
 125
 126        argv_array_pushf(&helper->env_array, "%s=%s", GIT_DIR_ENVIRONMENT,
 127                         get_git_dir());
 128
 129        code = start_command(helper);
 130        if (code < 0 && errno == ENOENT)
 131                die("Unable to find remote helper for '%s'", data->name);
 132        else if (code != 0)
 133                exit(code);
 134
 135        data->helper = helper;
 136        data->no_disconnect_req = 0;
 137
 138        /*
 139         * Open the output as FILE* so strbuf_getline() can be used.
 140         * Do this with duped fd because fclose() will close the fd,
 141         * and stuff like taking over will require the fd to remain.
 142         */
 143        duped = dup(helper->out);
 144        if (duped < 0)
 145                die_errno("Can't dup helper output fd");
 146        data->out = xfdopen(duped, "r");
 147
 148        write_constant(helper->in, "capabilities\n");
 149
 150        while (1) {
 151                const char *capname, *arg;
 152                int mandatory = 0;
 153                if (recvline(data, &buf))
 154                        exit(128);
 155
 156                if (!*buf.buf)
 157                        break;
 158
 159                if (*buf.buf == '*') {
 160                        capname = buf.buf + 1;
 161                        mandatory = 1;
 162                } else
 163                        capname = buf.buf;
 164
 165                if (debug)
 166                        fprintf(stderr, "Debug: Got cap %s\n", capname);
 167                if (!strcmp(capname, "fetch"))
 168                        data->fetch = 1;
 169                else if (!strcmp(capname, "option"))
 170                        data->option = 1;
 171                else if (!strcmp(capname, "push"))
 172                        data->push = 1;
 173                else if (!strcmp(capname, "import"))
 174                        data->import = 1;
 175                else if (!strcmp(capname, "bidi-import"))
 176                        data->bidi_import = 1;
 177                else if (!strcmp(capname, "export"))
 178                        data->export = 1;
 179                else if (!strcmp(capname, "check-connectivity"))
 180                        data->check_connectivity = 1;
 181                else if (!data->refspecs && skip_prefix(capname, "refspec ", &arg)) {
 182                        ALLOC_GROW(refspecs,
 183                                   refspec_nr + 1,
 184                                   refspec_alloc);
 185                        refspecs[refspec_nr++] = xstrdup(arg);
 186                } else if (!strcmp(capname, "connect")) {
 187                        data->connect = 1;
 188                } else if (!strcmp(capname, "signed-tags")) {
 189                        data->signed_tags = 1;
 190                } else if (skip_prefix(capname, "export-marks ", &arg)) {
 191                        data->export_marks = xstrdup(arg);
 192                } else if (skip_prefix(capname, "import-marks ", &arg)) {
 193                        data->import_marks = xstrdup(arg);
 194                } else if (starts_with(capname, "no-private-update")) {
 195                        data->no_private_update = 1;
 196                } else if (mandatory) {
 197                        die("Unknown mandatory capability %s. This remote "
 198                            "helper probably needs newer version of Git.",
 199                            capname);
 200                }
 201        }
 202        if (refspecs) {
 203                int i;
 204                data->refspec_nr = refspec_nr;
 205                data->refspecs = parse_fetch_refspec(refspec_nr, refspecs);
 206                for (i = 0; i < refspec_nr; i++)
 207                        free((char *)refspecs[i]);
 208                free(refspecs);
 209        } else if (data->import || data->bidi_import || data->export) {
 210                warning("This remote helper should implement refspec capability.");
 211        }
 212        strbuf_release(&buf);
 213        if (debug)
 214                fprintf(stderr, "Debug: Capabilities complete.\n");
 215        return data->helper;
 216}
 217
 218static int disconnect_helper(struct transport *transport)
 219{
 220        struct helper_data *data = transport->data;
 221        int res = 0;
 222
 223        if (data->helper) {
 224                if (debug)
 225                        fprintf(stderr, "Debug: Disconnecting.\n");
 226                if (!data->no_disconnect_req) {
 227                        /*
 228                         * Ignore write errors; there's nothing we can do,
 229                         * since we're about to close the pipe anyway. And the
 230                         * most likely error is EPIPE due to the helper dying
 231                         * to report an error itself.
 232                         */
 233                        sigchain_push(SIGPIPE, SIG_IGN);
 234                        xwrite(data->helper->in, "\n", 1);
 235                        sigchain_pop(SIGPIPE);
 236                }
 237                close(data->helper->in);
 238                close(data->helper->out);
 239                fclose(data->out);
 240                res = finish_command(data->helper);
 241                free(data->helper);
 242                data->helper = NULL;
 243        }
 244        return res;
 245}
 246
 247static const char *unsupported_options[] = {
 248        TRANS_OPT_UPLOADPACK,
 249        TRANS_OPT_RECEIVEPACK,
 250        TRANS_OPT_THIN,
 251        TRANS_OPT_KEEP
 252        };
 253
 254static const char *boolean_options[] = {
 255        TRANS_OPT_THIN,
 256        TRANS_OPT_KEEP,
 257        TRANS_OPT_FOLLOWTAGS,
 258        TRANS_OPT_PUSH_CERT
 259        };
 260
 261static int set_helper_option(struct transport *transport,
 262                          const char *name, const char *value)
 263{
 264        struct helper_data *data = transport->data;
 265        struct strbuf buf = STRBUF_INIT;
 266        int i, ret, is_bool = 0;
 267
 268        get_helper(transport);
 269
 270        if (!data->option)
 271                return 1;
 272
 273        for (i = 0; i < ARRAY_SIZE(unsupported_options); i++) {
 274                if (!strcmp(name, unsupported_options[i]))
 275                        return 1;
 276        }
 277
 278        for (i = 0; i < ARRAY_SIZE(boolean_options); i++) {
 279                if (!strcmp(name, boolean_options[i])) {
 280                        is_bool = 1;
 281                        break;
 282                }
 283        }
 284
 285        strbuf_addf(&buf, "option %s ", name);
 286        if (is_bool)
 287                strbuf_addstr(&buf, value ? "true" : "false");
 288        else
 289                quote_c_style(value, &buf, NULL, 0);
 290        strbuf_addch(&buf, '\n');
 291
 292        sendline(data, &buf);
 293        if (recvline(data, &buf))
 294                exit(128);
 295
 296        if (!strcmp(buf.buf, "ok"))
 297                ret = 0;
 298        else if (starts_with(buf.buf, "error")) {
 299                ret = -1;
 300        } else if (!strcmp(buf.buf, "unsupported"))
 301                ret = 1;
 302        else {
 303                warning("%s unexpectedly said: '%s'", data->name, buf.buf);
 304                ret = 1;
 305        }
 306        strbuf_release(&buf);
 307        return ret;
 308}
 309
 310static void standard_options(struct transport *t)
 311{
 312        char buf[16];
 313        int n;
 314        int v = t->verbose;
 315
 316        set_helper_option(t, "progress", t->progress ? "true" : "false");
 317
 318        n = snprintf(buf, sizeof(buf), "%d", v + 1);
 319        if (n >= sizeof(buf))
 320                die("impossibly large verbosity value");
 321        set_helper_option(t, "verbosity", buf);
 322}
 323
 324static int release_helper(struct transport *transport)
 325{
 326        int res = 0;
 327        struct helper_data *data = transport->data;
 328        free_refspec(data->refspec_nr, data->refspecs);
 329        data->refspecs = NULL;
 330        res = disconnect_helper(transport);
 331        free(transport->data);
 332        return res;
 333}
 334
 335static int fetch_with_fetch(struct transport *transport,
 336                            int nr_heads, struct ref **to_fetch)
 337{
 338        struct helper_data *data = transport->data;
 339        int i;
 340        struct strbuf buf = STRBUF_INIT;
 341
 342        standard_options(transport);
 343        if (data->check_connectivity &&
 344            data->transport_options.check_self_contained_and_connected)
 345                set_helper_option(transport, "check-connectivity", "true");
 346
 347        if (transport->cloning)
 348                set_helper_option(transport, "cloning", "true");
 349
 350        if (data->transport_options.update_shallow)
 351                set_helper_option(transport, "update-shallow", "true");
 352
 353        for (i = 0; i < nr_heads; i++) {
 354                const struct ref *posn = to_fetch[i];
 355                if (posn->status & REF_STATUS_UPTODATE)
 356                        continue;
 357
 358                strbuf_addf(&buf, "fetch %s %s\n",
 359                            sha1_to_hex(posn->old_sha1), posn->name);
 360        }
 361
 362        strbuf_addch(&buf, '\n');
 363        sendline(data, &buf);
 364
 365        while (1) {
 366                if (recvline(data, &buf))
 367                        exit(128);
 368
 369                if (starts_with(buf.buf, "lock ")) {
 370                        const char *name = buf.buf + 5;
 371                        if (transport->pack_lockfile)
 372                                warning("%s also locked %s", data->name, name);
 373                        else
 374                                transport->pack_lockfile = xstrdup(name);
 375                }
 376                else if (data->check_connectivity &&
 377                         data->transport_options.check_self_contained_and_connected &&
 378                         !strcmp(buf.buf, "connectivity-ok"))
 379                        data->transport_options.self_contained_and_connected = 1;
 380                else if (!buf.len)
 381                        break;
 382                else
 383                        warning("%s unexpectedly said: '%s'", data->name, buf.buf);
 384        }
 385        strbuf_release(&buf);
 386        return 0;
 387}
 388
 389static int get_importer(struct transport *transport, struct child_process *fastimport)
 390{
 391        struct child_process *helper = get_helper(transport);
 392        struct helper_data *data = transport->data;
 393        int cat_blob_fd, code;
 394        child_process_init(fastimport);
 395        fastimport->in = helper->out;
 396        argv_array_push(&fastimport->args, "fast-import");
 397        argv_array_push(&fastimport->args, debug ? "--stats" : "--quiet");
 398
 399        if (data->bidi_import) {
 400                cat_blob_fd = xdup(helper->in);
 401                argv_array_pushf(&fastimport->args, "--cat-blob-fd=%d", cat_blob_fd);
 402        }
 403        fastimport->git_cmd = 1;
 404
 405        code = start_command(fastimport);
 406        return code;
 407}
 408
 409static int get_exporter(struct transport *transport,
 410                        struct child_process *fastexport,
 411                        struct string_list *revlist_args)
 412{
 413        struct helper_data *data = transport->data;
 414        struct child_process *helper = get_helper(transport);
 415        int i;
 416
 417        child_process_init(fastexport);
 418
 419        /* we need to duplicate helper->in because we want to use it after
 420         * fastexport is done with it. */
 421        fastexport->out = dup(helper->in);
 422        argv_array_push(&fastexport->args, "fast-export");
 423        argv_array_push(&fastexport->args, "--use-done-feature");
 424        argv_array_push(&fastexport->args, data->signed_tags ?
 425                "--signed-tags=verbatim" : "--signed-tags=warn-strip");
 426        if (data->export_marks)
 427                argv_array_pushf(&fastexport->args, "--export-marks=%s.tmp", data->export_marks);
 428        if (data->import_marks)
 429                argv_array_pushf(&fastexport->args, "--import-marks=%s", data->import_marks);
 430
 431        for (i = 0; i < revlist_args->nr; i++)
 432                argv_array_push(&fastexport->args, revlist_args->items[i].string);
 433
 434        fastexport->git_cmd = 1;
 435        return start_command(fastexport);
 436}
 437
 438static int fetch_with_import(struct transport *transport,
 439                             int nr_heads, struct ref **to_fetch)
 440{
 441        struct child_process fastimport;
 442        struct helper_data *data = transport->data;
 443        int i;
 444        struct ref *posn;
 445        struct strbuf buf = STRBUF_INIT;
 446
 447        get_helper(transport);
 448
 449        if (get_importer(transport, &fastimport))
 450                die("Couldn't run fast-import");
 451
 452        for (i = 0; i < nr_heads; i++) {
 453                posn = to_fetch[i];
 454                if (posn->status & REF_STATUS_UPTODATE)
 455                        continue;
 456
 457                strbuf_addf(&buf, "import %s\n", posn->name);
 458                sendline(data, &buf);
 459                strbuf_reset(&buf);
 460        }
 461
 462        write_constant(data->helper->in, "\n");
 463        /*
 464         * remote-helpers that advertise the bidi-import capability are required to
 465         * buffer the complete batch of import commands until this newline before
 466         * sending data to fast-import.
 467         * These helpers read back data from fast-import on their stdin, which could
 468         * be mixed with import commands, otherwise.
 469         */
 470
 471        if (finish_command(&fastimport))
 472                die("Error while running fast-import");
 473
 474        /*
 475         * The fast-import stream of a remote helper that advertises
 476         * the "refspec" capability writes to the refs named after the
 477         * right hand side of the first refspec matching each ref we
 478         * were fetching.
 479         *
 480         * (If no "refspec" capability was specified, for historical
 481         * reasons we default to the equivalent of *:*.)
 482         *
 483         * Store the result in to_fetch[i].old_sha1.  Callers such
 484         * as "git fetch" can use the value to write feedback to the
 485         * terminal, populate FETCH_HEAD, and determine what new value
 486         * should be written to peer_ref if the update is a
 487         * fast-forward or this is a forced update.
 488         */
 489        for (i = 0; i < nr_heads; i++) {
 490                char *private;
 491                posn = to_fetch[i];
 492                if (posn->status & REF_STATUS_UPTODATE)
 493                        continue;
 494                if (data->refspecs)
 495                        private = apply_refspecs(data->refspecs, data->refspec_nr, posn->name);
 496                else
 497                        private = xstrdup(posn->name);
 498                if (private) {
 499                        read_ref(private, posn->old_sha1);
 500                        free(private);
 501                }
 502        }
 503        strbuf_release(&buf);
 504        return 0;
 505}
 506
 507static int process_connect_service(struct transport *transport,
 508                                   const char *name, const char *exec)
 509{
 510        struct helper_data *data = transport->data;
 511        struct strbuf cmdbuf = STRBUF_INIT;
 512        struct child_process *helper;
 513        int r, duped, ret = 0;
 514        FILE *input;
 515
 516        helper = get_helper(transport);
 517
 518        /*
 519         * Yes, dup the pipe another time, as we need unbuffered version
 520         * of input pipe as FILE*. fclose() closes the underlying fd and
 521         * stream buffering only can be changed before first I/O operation
 522         * on it.
 523         */
 524        duped = dup(helper->out);
 525        if (duped < 0)
 526                die_errno("Can't dup helper output fd");
 527        input = xfdopen(duped, "r");
 528        setvbuf(input, NULL, _IONBF, 0);
 529
 530        /*
 531         * Handle --upload-pack and friends. This is fire and forget...
 532         * just warn if it fails.
 533         */
 534        if (strcmp(name, exec)) {
 535                r = set_helper_option(transport, "servpath", exec);
 536                if (r > 0)
 537                        warning("Setting remote service path not supported by protocol.");
 538                else if (r < 0)
 539                        warning("Invalid remote service path.");
 540        }
 541
 542        if (data->connect)
 543                strbuf_addf(&cmdbuf, "connect %s\n", name);
 544        else
 545                goto exit;
 546
 547        sendline(data, &cmdbuf);
 548        if (recvline_fh(input, &cmdbuf, name))
 549                exit(128);
 550
 551        if (!strcmp(cmdbuf.buf, "")) {
 552                data->no_disconnect_req = 1;
 553                if (debug)
 554                        fprintf(stderr, "Debug: Smart transport connection "
 555                                "ready.\n");
 556                ret = 1;
 557        } else if (!strcmp(cmdbuf.buf, "fallback")) {
 558                if (debug)
 559                        fprintf(stderr, "Debug: Falling back to dumb "
 560                                "transport.\n");
 561        } else
 562                die("Unknown response to connect: %s",
 563                        cmdbuf.buf);
 564
 565exit:
 566        fclose(input);
 567        return ret;
 568}
 569
 570static int process_connect(struct transport *transport,
 571                                     int for_push)
 572{
 573        struct helper_data *data = transport->data;
 574        const char *name;
 575        const char *exec;
 576
 577        name = for_push ? "git-receive-pack" : "git-upload-pack";
 578        if (for_push)
 579                exec = data->transport_options.receivepack;
 580        else
 581                exec = data->transport_options.uploadpack;
 582
 583        return process_connect_service(transport, name, exec);
 584}
 585
 586static int connect_helper(struct transport *transport, const char *name,
 587                   const char *exec, int fd[2])
 588{
 589        struct helper_data *data = transport->data;
 590
 591        /* Get_helper so connect is inited. */
 592        get_helper(transport);
 593        if (!data->connect)
 594                die("Operation not supported by protocol.");
 595
 596        if (!process_connect_service(transport, name, exec))
 597                die("Can't connect to subservice %s.", name);
 598
 599        fd[0] = data->helper->out;
 600        fd[1] = data->helper->in;
 601        return 0;
 602}
 603
 604static int fetch(struct transport *transport,
 605                 int nr_heads, struct ref **to_fetch)
 606{
 607        struct helper_data *data = transport->data;
 608        int i, count;
 609
 610        if (process_connect(transport, 0)) {
 611                do_take_over(transport);
 612                return transport->fetch(transport, nr_heads, to_fetch);
 613        }
 614
 615        count = 0;
 616        for (i = 0; i < nr_heads; i++)
 617                if (!(to_fetch[i]->status & REF_STATUS_UPTODATE))
 618                        count++;
 619
 620        if (!count)
 621                return 0;
 622
 623        if (data->fetch)
 624                return fetch_with_fetch(transport, nr_heads, to_fetch);
 625
 626        if (data->import)
 627                return fetch_with_import(transport, nr_heads, to_fetch);
 628
 629        return -1;
 630}
 631
 632static int push_update_ref_status(struct strbuf *buf,
 633                                   struct ref **ref,
 634                                   struct ref *remote_refs)
 635{
 636        char *refname, *msg;
 637        int status, forced = 0;
 638
 639        if (starts_with(buf->buf, "ok ")) {
 640                status = REF_STATUS_OK;
 641                refname = buf->buf + 3;
 642        } else if (starts_with(buf->buf, "error ")) {
 643                status = REF_STATUS_REMOTE_REJECT;
 644                refname = buf->buf + 6;
 645        } else
 646                die("expected ok/error, helper said '%s'", buf->buf);
 647
 648        msg = strchr(refname, ' ');
 649        if (msg) {
 650                struct strbuf msg_buf = STRBUF_INIT;
 651                const char *end;
 652
 653                *msg++ = '\0';
 654                if (!unquote_c_style(&msg_buf, msg, &end))
 655                        msg = strbuf_detach(&msg_buf, NULL);
 656                else
 657                        msg = xstrdup(msg);
 658                strbuf_release(&msg_buf);
 659
 660                if (!strcmp(msg, "no match")) {
 661                        status = REF_STATUS_NONE;
 662                        free(msg);
 663                        msg = NULL;
 664                }
 665                else if (!strcmp(msg, "up to date")) {
 666                        status = REF_STATUS_UPTODATE;
 667                        free(msg);
 668                        msg = NULL;
 669                }
 670                else if (!strcmp(msg, "non-fast forward")) {
 671                        status = REF_STATUS_REJECT_NONFASTFORWARD;
 672                        free(msg);
 673                        msg = NULL;
 674                }
 675                else if (!strcmp(msg, "already exists")) {
 676                        status = REF_STATUS_REJECT_ALREADY_EXISTS;
 677                        free(msg);
 678                        msg = NULL;
 679                }
 680                else if (!strcmp(msg, "fetch first")) {
 681                        status = REF_STATUS_REJECT_FETCH_FIRST;
 682                        free(msg);
 683                        msg = NULL;
 684                }
 685                else if (!strcmp(msg, "needs force")) {
 686                        status = REF_STATUS_REJECT_NEEDS_FORCE;
 687                        free(msg);
 688                        msg = NULL;
 689                }
 690                else if (!strcmp(msg, "stale info")) {
 691                        status = REF_STATUS_REJECT_STALE;
 692                        free(msg);
 693                        msg = NULL;
 694                }
 695                else if (!strcmp(msg, "forced update")) {
 696                        forced = 1;
 697                        free(msg);
 698                        msg = NULL;
 699                }
 700        }
 701
 702        if (*ref)
 703                *ref = find_ref_by_name(*ref, refname);
 704        if (!*ref)
 705                *ref = find_ref_by_name(remote_refs, refname);
 706        if (!*ref) {
 707                warning("helper reported unexpected status of %s", refname);
 708                return 1;
 709        }
 710
 711        if ((*ref)->status != REF_STATUS_NONE) {
 712                /*
 713                 * Earlier, the ref was marked not to be pushed, so ignore the ref
 714                 * status reported by the remote helper if the latter is 'no match'.
 715                 */
 716                if (status == REF_STATUS_NONE)
 717                        return 1;
 718        }
 719
 720        (*ref)->status = status;
 721        (*ref)->forced_update |= forced;
 722        (*ref)->remote_status = msg;
 723        return !(status == REF_STATUS_OK);
 724}
 725
 726static int push_update_refs_status(struct helper_data *data,
 727                                    struct ref *remote_refs,
 728                                    int flags)
 729{
 730        struct strbuf buf = STRBUF_INIT;
 731        struct ref *ref = remote_refs;
 732        int ret = 0;
 733
 734        for (;;) {
 735                char *private;
 736
 737                if (recvline(data, &buf)) {
 738                        ret = 1;
 739                        break;
 740                }
 741
 742                if (!buf.len)
 743                        break;
 744
 745                if (push_update_ref_status(&buf, &ref, remote_refs))
 746                        continue;
 747
 748                if (flags & TRANSPORT_PUSH_DRY_RUN || !data->refspecs || data->no_private_update)
 749                        continue;
 750
 751                /* propagate back the update to the remote namespace */
 752                private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
 753                if (!private)
 754                        continue;
 755                update_ref("update by helper", private, ref->new_sha1, NULL, 0, 0);
 756                free(private);
 757        }
 758        strbuf_release(&buf);
 759        return ret;
 760}
 761
 762static int push_refs_with_push(struct transport *transport,
 763                               struct ref *remote_refs, int flags)
 764{
 765        int force_all = flags & TRANSPORT_PUSH_FORCE;
 766        int mirror = flags & TRANSPORT_PUSH_MIRROR;
 767        struct helper_data *data = transport->data;
 768        struct strbuf buf = STRBUF_INIT;
 769        struct ref *ref;
 770        struct string_list cas_options = STRING_LIST_INIT_DUP;
 771        struct string_list_item *cas_option;
 772
 773        get_helper(transport);
 774        if (!data->push)
 775                return 1;
 776
 777        for (ref = remote_refs; ref; ref = ref->next) {
 778                if (!ref->peer_ref && !mirror)
 779                        continue;
 780
 781                /* Check for statuses set by set_ref_status_for_push() */
 782                switch (ref->status) {
 783                case REF_STATUS_REJECT_NONFASTFORWARD:
 784                case REF_STATUS_REJECT_STALE:
 785                case REF_STATUS_REJECT_ALREADY_EXISTS:
 786                case REF_STATUS_UPTODATE:
 787                        continue;
 788                default:
 789                        ; /* do nothing */
 790                }
 791
 792                if (force_all)
 793                        ref->force = 1;
 794
 795                strbuf_addstr(&buf, "push ");
 796                if (!ref->deletion) {
 797                        if (ref->force)
 798                                strbuf_addch(&buf, '+');
 799                        if (ref->peer_ref)
 800                                strbuf_addstr(&buf, ref->peer_ref->name);
 801                        else
 802                                strbuf_addstr(&buf, sha1_to_hex(ref->new_sha1));
 803                }
 804                strbuf_addch(&buf, ':');
 805                strbuf_addstr(&buf, ref->name);
 806                strbuf_addch(&buf, '\n');
 807
 808                /*
 809                 * The "--force-with-lease" options without explicit
 810                 * values to expect have already been expanded into
 811                 * the ref->old_sha1_expect[] field; we can ignore
 812                 * transport->smart_options->cas altogether and instead
 813                 * can enumerate them from the refs.
 814                 */
 815                if (ref->expect_old_sha1) {
 816                        struct strbuf cas = STRBUF_INIT;
 817                        strbuf_addf(&cas, "%s:%s",
 818                                    ref->name, sha1_to_hex(ref->old_sha1_expect));
 819                        string_list_append(&cas_options, strbuf_detach(&cas, NULL));
 820                }
 821        }
 822        if (buf.len == 0) {
 823                string_list_clear(&cas_options, 0);
 824                return 0;
 825        }
 826
 827        standard_options(transport);
 828        for_each_string_list_item(cas_option, &cas_options)
 829                set_helper_option(transport, "cas", cas_option->string);
 830
 831        if (flags & TRANSPORT_PUSH_DRY_RUN) {
 832                if (set_helper_option(transport, "dry-run", "true") != 0)
 833                        die("helper %s does not support dry-run", data->name);
 834        } else if (flags & TRANSPORT_PUSH_CERT) {
 835                if (set_helper_option(transport, TRANS_OPT_PUSH_CERT, "true") != 0)
 836                        die("helper %s does not support --signed", data->name);
 837        }
 838
 839        strbuf_addch(&buf, '\n');
 840        sendline(data, &buf);
 841        strbuf_release(&buf);
 842
 843        return push_update_refs_status(data, remote_refs, flags);
 844}
 845
 846static int push_refs_with_export(struct transport *transport,
 847                struct ref *remote_refs, int flags)
 848{
 849        struct ref *ref;
 850        struct child_process *helper, exporter;
 851        struct helper_data *data = transport->data;
 852        struct string_list revlist_args = STRING_LIST_INIT_DUP;
 853        struct strbuf buf = STRBUF_INIT;
 854
 855        if (!data->refspecs)
 856                die("remote-helper doesn't support push; refspec needed");
 857
 858        if (flags & TRANSPORT_PUSH_DRY_RUN) {
 859                if (set_helper_option(transport, "dry-run", "true") != 0)
 860                        die("helper %s does not support dry-run", data->name);
 861        } else if (flags & TRANSPORT_PUSH_CERT) {
 862                if (set_helper_option(transport, TRANS_OPT_PUSH_CERT, "true") != 0)
 863                        die("helper %s does not support dry-run", data->name);
 864        }
 865
 866        if (flags & TRANSPORT_PUSH_FORCE) {
 867                if (set_helper_option(transport, "force", "true") != 0)
 868                        warning("helper %s does not support 'force'", data->name);
 869        }
 870
 871        helper = get_helper(transport);
 872
 873        write_constant(helper->in, "export\n");
 874
 875        for (ref = remote_refs; ref; ref = ref->next) {
 876                char *private;
 877                unsigned char sha1[20];
 878
 879                private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
 880                if (private && !get_sha1(private, sha1)) {
 881                        strbuf_addf(&buf, "^%s", private);
 882                        string_list_append(&revlist_args, strbuf_detach(&buf, NULL));
 883                        hashcpy(ref->old_sha1, sha1);
 884                }
 885                free(private);
 886
 887                if (ref->peer_ref) {
 888                        if (strcmp(ref->name, ref->peer_ref->name)) {
 889                                if (!ref->deletion) {
 890                                        const char *name;
 891                                        int flag;
 892
 893                                        /* Follow symbolic refs (mainly for HEAD). */
 894                                        name = resolve_ref_unsafe(
 895                                                 ref->peer_ref->name,
 896                                                 RESOLVE_REF_READING,
 897                                                 sha1, &flag);
 898                                        if (!name || !(flag & REF_ISSYMREF))
 899                                                name = ref->peer_ref->name;
 900
 901                                        strbuf_addf(&buf, "%s:%s", name, ref->name);
 902                                } else
 903                                        strbuf_addf(&buf, ":%s", ref->name);
 904
 905                                string_list_append(&revlist_args, "--refspec");
 906                                string_list_append(&revlist_args, buf.buf);
 907                                strbuf_release(&buf);
 908                        }
 909                        if (!ref->deletion)
 910                                string_list_append(&revlist_args, ref->peer_ref->name);
 911                }
 912        }
 913
 914        if (get_exporter(transport, &exporter, &revlist_args))
 915                die("Couldn't run fast-export");
 916
 917        string_list_clear(&revlist_args, 1);
 918
 919        if (finish_command(&exporter))
 920                die("Error while running fast-export");
 921        if (push_update_refs_status(data, remote_refs, flags))
 922                return 1;
 923
 924        if (data->export_marks) {
 925                strbuf_addf(&buf, "%s.tmp", data->export_marks);
 926                rename(buf.buf, data->export_marks);
 927                strbuf_release(&buf);
 928        }
 929
 930        return 0;
 931}
 932
 933static int push_refs(struct transport *transport,
 934                struct ref *remote_refs, int flags)
 935{
 936        struct helper_data *data = transport->data;
 937
 938        if (process_connect(transport, 1)) {
 939                do_take_over(transport);
 940                return transport->push_refs(transport, remote_refs, flags);
 941        }
 942
 943        if (!remote_refs) {
 944                fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
 945                        "Perhaps you should specify a branch such as 'master'.\n");
 946                return 0;
 947        }
 948
 949        if (data->push)
 950                return push_refs_with_push(transport, remote_refs, flags);
 951
 952        if (data->export)
 953                return push_refs_with_export(transport, remote_refs, flags);
 954
 955        return -1;
 956}
 957
 958
 959static int has_attribute(const char *attrs, const char *attr) {
 960        int len;
 961        if (!attrs)
 962                return 0;
 963
 964        len = strlen(attr);
 965        for (;;) {
 966                const char *space = strchrnul(attrs, ' ');
 967                if (len == space - attrs && !strncmp(attrs, attr, len))
 968                        return 1;
 969                if (!*space)
 970                        return 0;
 971                attrs = space + 1;
 972        }
 973}
 974
 975static struct ref *get_refs_list(struct transport *transport, int for_push)
 976{
 977        struct helper_data *data = transport->data;
 978        struct child_process *helper;
 979        struct ref *ret = NULL;
 980        struct ref **tail = &ret;
 981        struct ref *posn;
 982        struct strbuf buf = STRBUF_INIT;
 983
 984        helper = get_helper(transport);
 985
 986        if (process_connect(transport, for_push)) {
 987                do_take_over(transport);
 988                return transport->get_refs_list(transport, for_push);
 989        }
 990
 991        if (data->push && for_push)
 992                write_str_in_full(helper->in, "list for-push\n");
 993        else
 994                write_str_in_full(helper->in, "list\n");
 995
 996        while (1) {
 997                char *eov, *eon;
 998                if (recvline(data, &buf))
 999                        exit(128);
1000
1001                if (!*buf.buf)
1002                        break;
1003
1004                eov = strchr(buf.buf, ' ');
1005                if (!eov)
1006                        die("Malformed response in ref list: %s", buf.buf);
1007                eon = strchr(eov + 1, ' ');
1008                *eov = '\0';
1009                if (eon)
1010                        *eon = '\0';
1011                *tail = alloc_ref(eov + 1);
1012                if (buf.buf[0] == '@')
1013                        (*tail)->symref = xstrdup(buf.buf + 1);
1014                else if (buf.buf[0] != '?')
1015                        get_sha1_hex(buf.buf, (*tail)->old_sha1);
1016                if (eon) {
1017                        if (has_attribute(eon + 1, "unchanged")) {
1018                                (*tail)->status |= REF_STATUS_UPTODATE;
1019                                read_ref((*tail)->name, (*tail)->old_sha1);
1020                        }
1021                }
1022                tail = &((*tail)->next);
1023        }
1024        if (debug)
1025                fprintf(stderr, "Debug: Read ref listing.\n");
1026        strbuf_release(&buf);
1027
1028        for (posn = ret; posn; posn = posn->next)
1029                resolve_remote_symref(posn, ret);
1030
1031        return ret;
1032}
1033
1034int transport_helper_init(struct transport *transport, const char *name)
1035{
1036        struct helper_data *data = xcalloc(1, sizeof(*data));
1037        data->name = name;
1038
1039        if (getenv("GIT_TRANSPORT_HELPER_DEBUG"))
1040                debug = 1;
1041
1042        transport->data = data;
1043        transport->set_option = set_helper_option;
1044        transport->get_refs_list = get_refs_list;
1045        transport->fetch = fetch;
1046        transport->push_refs = push_refs;
1047        transport->disconnect = release_helper;
1048        transport->connect = connect_helper;
1049        transport->smart_options = &(data->transport_options);
1050        return 0;
1051}
1052
1053/*
1054 * Linux pipes can buffer 65536 bytes at once (and most platforms can
1055 * buffer less), so attempt reads and writes with up to that size.
1056 */
1057#define BUFFERSIZE 65536
1058/* This should be enough to hold debugging message. */
1059#define PBUFFERSIZE 8192
1060
1061/* Print bidirectional transfer loop debug message. */
1062__attribute__((format (printf, 1, 2)))
1063static void transfer_debug(const char *fmt, ...)
1064{
1065        va_list args;
1066        char msgbuf[PBUFFERSIZE];
1067        static int debug_enabled = -1;
1068
1069        if (debug_enabled < 0)
1070                debug_enabled = getenv("GIT_TRANSLOOP_DEBUG") ? 1 : 0;
1071        if (!debug_enabled)
1072                return;
1073
1074        va_start(args, fmt);
1075        vsnprintf(msgbuf, PBUFFERSIZE, fmt, args);
1076        va_end(args);
1077        fprintf(stderr, "Transfer loop debugging: %s\n", msgbuf);
1078}
1079
1080/* Stream state: More data may be coming in this direction. */
1081#define SSTATE_TRANSFERING 0
1082/*
1083 * Stream state: No more data coming in this direction, flushing rest of
1084 * data.
1085 */
1086#define SSTATE_FLUSHING 1
1087/* Stream state: Transfer in this direction finished. */
1088#define SSTATE_FINISHED 2
1089
1090#define STATE_NEEDS_READING(state) ((state) <= SSTATE_TRANSFERING)
1091#define STATE_NEEDS_WRITING(state) ((state) <= SSTATE_FLUSHING)
1092#define STATE_NEEDS_CLOSING(state) ((state) == SSTATE_FLUSHING)
1093
1094/* Unidirectional transfer. */
1095struct unidirectional_transfer {
1096        /* Source */
1097        int src;
1098        /* Destination */
1099        int dest;
1100        /* Is source socket? */
1101        int src_is_sock;
1102        /* Is destination socket? */
1103        int dest_is_sock;
1104        /* Transfer state (TRANSFERRING/FLUSHING/FINISHED) */
1105        int state;
1106        /* Buffer. */
1107        char buf[BUFFERSIZE];
1108        /* Buffer used. */
1109        size_t bufuse;
1110        /* Name of source. */
1111        const char *src_name;
1112        /* Name of destination. */
1113        const char *dest_name;
1114};
1115
1116/* Closes the target (for writing) if transfer has finished. */
1117static void udt_close_if_finished(struct unidirectional_transfer *t)
1118{
1119        if (STATE_NEEDS_CLOSING(t->state) && !t->bufuse) {
1120                t->state = SSTATE_FINISHED;
1121                if (t->dest_is_sock)
1122                        shutdown(t->dest, SHUT_WR);
1123                else
1124                        close(t->dest);
1125                transfer_debug("Closed %s.", t->dest_name);
1126        }
1127}
1128
1129/*
1130 * Tries to read read data from source into buffer. If buffer is full,
1131 * no data is read. Returns 0 on success, -1 on error.
1132 */
1133static int udt_do_read(struct unidirectional_transfer *t)
1134{
1135        ssize_t bytes;
1136
1137        if (t->bufuse == BUFFERSIZE)
1138                return 0;       /* No space for more. */
1139
1140        transfer_debug("%s is readable", t->src_name);
1141        bytes = read(t->src, t->buf + t->bufuse, BUFFERSIZE - t->bufuse);
1142        if (bytes < 0 && errno != EWOULDBLOCK && errno != EAGAIN &&
1143                errno != EINTR) {
1144                error("read(%s) failed: %s", t->src_name, strerror(errno));
1145                return -1;
1146        } else if (bytes == 0) {
1147                transfer_debug("%s EOF (with %i bytes in buffer)",
1148                        t->src_name, (int)t->bufuse);
1149                t->state = SSTATE_FLUSHING;
1150        } else if (bytes > 0) {
1151                t->bufuse += bytes;
1152                transfer_debug("Read %i bytes from %s (buffer now at %i)",
1153                        (int)bytes, t->src_name, (int)t->bufuse);
1154        }
1155        return 0;
1156}
1157
1158/* Tries to write data from buffer into destination. If buffer is empty,
1159 * no data is written. Returns 0 on success, -1 on error.
1160 */
1161static int udt_do_write(struct unidirectional_transfer *t)
1162{
1163        ssize_t bytes;
1164
1165        if (t->bufuse == 0)
1166                return 0;       /* Nothing to write. */
1167
1168        transfer_debug("%s is writable", t->dest_name);
1169        bytes = xwrite(t->dest, t->buf, t->bufuse);
1170        if (bytes < 0 && errno != EWOULDBLOCK) {
1171                error("write(%s) failed: %s", t->dest_name, strerror(errno));
1172                return -1;
1173        } else if (bytes > 0) {
1174                t->bufuse -= bytes;
1175                if (t->bufuse)
1176                        memmove(t->buf, t->buf + bytes, t->bufuse);
1177                transfer_debug("Wrote %i bytes to %s (buffer now at %i)",
1178                        (int)bytes, t->dest_name, (int)t->bufuse);
1179        }
1180        return 0;
1181}
1182
1183
1184/* State of bidirectional transfer loop. */
1185struct bidirectional_transfer_state {
1186        /* Direction from program to git. */
1187        struct unidirectional_transfer ptg;
1188        /* Direction from git to program. */
1189        struct unidirectional_transfer gtp;
1190};
1191
1192static void *udt_copy_task_routine(void *udt)
1193{
1194        struct unidirectional_transfer *t = (struct unidirectional_transfer *)udt;
1195        while (t->state != SSTATE_FINISHED) {
1196                if (STATE_NEEDS_READING(t->state))
1197                        if (udt_do_read(t))
1198                                return NULL;
1199                if (STATE_NEEDS_WRITING(t->state))
1200                        if (udt_do_write(t))
1201                                return NULL;
1202                if (STATE_NEEDS_CLOSING(t->state))
1203                        udt_close_if_finished(t);
1204        }
1205        return udt;     /* Just some non-NULL value. */
1206}
1207
1208#ifndef NO_PTHREADS
1209
1210/*
1211 * Join thread, with appropriate errors on failure. Name is name for the
1212 * thread (for error messages). Returns 0 on success, 1 on failure.
1213 */
1214static int tloop_join(pthread_t thread, const char *name)
1215{
1216        int err;
1217        void *tret;
1218        err = pthread_join(thread, &tret);
1219        if (!tret) {
1220                error("%s thread failed", name);
1221                return 1;
1222        }
1223        if (err) {
1224                error("%s thread failed to join: %s", name, strerror(err));
1225                return 1;
1226        }
1227        return 0;
1228}
1229
1230/*
1231 * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1232 * -1 on failure.
1233 */
1234static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1235{
1236        pthread_t gtp_thread;
1237        pthread_t ptg_thread;
1238        int err;
1239        int ret = 0;
1240        err = pthread_create(&gtp_thread, NULL, udt_copy_task_routine,
1241                &s->gtp);
1242        if (err)
1243                die("Can't start thread for copying data: %s", strerror(err));
1244        err = pthread_create(&ptg_thread, NULL, udt_copy_task_routine,
1245                &s->ptg);
1246        if (err)
1247                die("Can't start thread for copying data: %s", strerror(err));
1248
1249        ret |= tloop_join(gtp_thread, "Git to program copy");
1250        ret |= tloop_join(ptg_thread, "Program to git copy");
1251        return ret;
1252}
1253#else
1254
1255/* Close the source and target (for writing) for transfer. */
1256static void udt_kill_transfer(struct unidirectional_transfer *t)
1257{
1258        t->state = SSTATE_FINISHED;
1259        /*
1260         * Socket read end left open isn't a disaster if nobody
1261         * attempts to read from it (mingw compat headers do not
1262         * have SHUT_RD)...
1263         *
1264         * We can't fully close the socket since otherwise gtp
1265         * task would first close the socket it sends data to
1266         * while closing the ptg file descriptors.
1267         */
1268        if (!t->src_is_sock)
1269                close(t->src);
1270        if (t->dest_is_sock)
1271                shutdown(t->dest, SHUT_WR);
1272        else
1273                close(t->dest);
1274}
1275
1276/*
1277 * Join process, with appropriate errors on failure. Name is name for the
1278 * process (for error messages). Returns 0 on success, 1 on failure.
1279 */
1280static int tloop_join(pid_t pid, const char *name)
1281{
1282        int tret;
1283        if (waitpid(pid, &tret, 0) < 0) {
1284                error("%s process failed to wait: %s", name, strerror(errno));
1285                return 1;
1286        }
1287        if (!WIFEXITED(tret) || WEXITSTATUS(tret)) {
1288                error("%s process failed", name);
1289                return 1;
1290        }
1291        return 0;
1292}
1293
1294/*
1295 * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1296 * -1 on failure.
1297 */
1298static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1299{
1300        pid_t pid1, pid2;
1301        int ret = 0;
1302
1303        /* Fork thread #1: git to program. */
1304        pid1 = fork();
1305        if (pid1 < 0)
1306                die_errno("Can't start thread for copying data");
1307        else if (pid1 == 0) {
1308                udt_kill_transfer(&s->ptg);
1309                exit(udt_copy_task_routine(&s->gtp) ? 0 : 1);
1310        }
1311
1312        /* Fork thread #2: program to git. */
1313        pid2 = fork();
1314        if (pid2 < 0)
1315                die_errno("Can't start thread for copying data");
1316        else if (pid2 == 0) {
1317                udt_kill_transfer(&s->gtp);
1318                exit(udt_copy_task_routine(&s->ptg) ? 0 : 1);
1319        }
1320
1321        /*
1322         * Close both streams in parent as to not interfere with
1323         * end of file detection and wait for both tasks to finish.
1324         */
1325        udt_kill_transfer(&s->gtp);
1326        udt_kill_transfer(&s->ptg);
1327        ret |= tloop_join(pid1, "Git to program copy");
1328        ret |= tloop_join(pid2, "Program to git copy");
1329        return ret;
1330}
1331#endif
1332
1333/*
1334 * Copies data from stdin to output and from input to stdout simultaneously.
1335 * Additionally filtering through given filter. If filter is NULL, uses
1336 * identity filter.
1337 */
1338int bidirectional_transfer_loop(int input, int output)
1339{
1340        struct bidirectional_transfer_state state;
1341
1342        /* Fill the state fields. */
1343        state.ptg.src = input;
1344        state.ptg.dest = 1;
1345        state.ptg.src_is_sock = (input == output);
1346        state.ptg.dest_is_sock = 0;
1347        state.ptg.state = SSTATE_TRANSFERING;
1348        state.ptg.bufuse = 0;
1349        state.ptg.src_name = "remote input";
1350        state.ptg.dest_name = "stdout";
1351
1352        state.gtp.src = 0;
1353        state.gtp.dest = output;
1354        state.gtp.src_is_sock = 0;
1355        state.gtp.dest_is_sock = (input == output);
1356        state.gtp.state = SSTATE_TRANSFERING;
1357        state.gtp.bufuse = 0;
1358        state.gtp.src_name = "stdin";
1359        state.gtp.dest_name = "remote output";
1360
1361        return tloop_spawnwait_tasks(&state);
1362}