transport-helper.con commit for-each-ref: report broken references correctly (8afc493)
   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 struct child_process *get_helper(struct transport *transport)
 101{
 102        struct helper_data *data = transport->data;
 103        struct strbuf buf = STRBUF_INIT;
 104        struct child_process *helper;
 105        const char **refspecs = NULL;
 106        int refspec_nr = 0;
 107        int refspec_alloc = 0;
 108        int duped;
 109        int code;
 110
 111        if (data->helper)
 112                return data->helper;
 113
 114        helper = xmalloc(sizeof(*helper));
 115        child_process_init(helper);
 116        helper->in = -1;
 117        helper->out = -1;
 118        helper->err = 0;
 119        argv_array_pushf(&helper->args, "git-remote-%s", data->name);
 120        argv_array_push(&helper->args, transport->remote->name);
 121        argv_array_push(&helper->args, remove_ext_force(transport->url));
 122        helper->git_cmd = 0;
 123        helper->silent_exec_failure = 1;
 124
 125        argv_array_pushf(&helper->env_array, "%s=%s", GIT_DIR_ENVIRONMENT,
 126                         get_git_dir());
 127
 128        code = start_command(helper);
 129        if (code < 0 && errno == ENOENT)
 130                die("Unable to find remote helper for '%s'", data->name);
 131        else if (code != 0)
 132                exit(code);
 133
 134        data->helper = helper;
 135        data->no_disconnect_req = 0;
 136
 137        /*
 138         * Open the output as FILE* so strbuf_getline() can be used.
 139         * Do this with duped fd because fclose() will close the fd,
 140         * and stuff like taking over will require the fd to remain.
 141         */
 142        duped = dup(helper->out);
 143        if (duped < 0)
 144                die_errno("Can't dup helper output fd");
 145        data->out = xfdopen(duped, "r");
 146
 147        write_constant(helper->in, "capabilities\n");
 148
 149        while (1) {
 150                const char *capname, *arg;
 151                int mandatory = 0;
 152                if (recvline(data, &buf))
 153                        exit(128);
 154
 155                if (!*buf.buf)
 156                        break;
 157
 158                if (*buf.buf == '*') {
 159                        capname = buf.buf + 1;
 160                        mandatory = 1;
 161                } else
 162                        capname = buf.buf;
 163
 164                if (debug)
 165                        fprintf(stderr, "Debug: Got cap %s\n", capname);
 166                if (!strcmp(capname, "fetch"))
 167                        data->fetch = 1;
 168                else if (!strcmp(capname, "option"))
 169                        data->option = 1;
 170                else if (!strcmp(capname, "push"))
 171                        data->push = 1;
 172                else if (!strcmp(capname, "import"))
 173                        data->import = 1;
 174                else if (!strcmp(capname, "bidi-import"))
 175                        data->bidi_import = 1;
 176                else if (!strcmp(capname, "export"))
 177                        data->export = 1;
 178                else if (!strcmp(capname, "check-connectivity"))
 179                        data->check_connectivity = 1;
 180                else if (!data->refspecs && skip_prefix(capname, "refspec ", &arg)) {
 181                        ALLOC_GROW(refspecs,
 182                                   refspec_nr + 1,
 183                                   refspec_alloc);
 184                        refspecs[refspec_nr++] = xstrdup(arg);
 185                } else if (!strcmp(capname, "connect")) {
 186                        data->connect = 1;
 187                } else if (!strcmp(capname, "signed-tags")) {
 188                        data->signed_tags = 1;
 189                } else if (skip_prefix(capname, "export-marks ", &arg)) {
 190                        data->export_marks = xstrdup(arg);
 191                } else if (skip_prefix(capname, "import-marks ", &arg)) {
 192                        data->import_marks = xstrdup(arg);
 193                } else if (starts_with(capname, "no-private-update")) {
 194                        data->no_private_update = 1;
 195                } else if (mandatory) {
 196                        die("Unknown mandatory capability %s. This remote "
 197                            "helper probably needs newer version of Git.",
 198                            capname);
 199                }
 200        }
 201        if (refspecs) {
 202                int i;
 203                data->refspec_nr = refspec_nr;
 204                data->refspecs = parse_fetch_refspec(refspec_nr, refspecs);
 205                for (i = 0; i < refspec_nr; i++)
 206                        free((char *)refspecs[i]);
 207                free(refspecs);
 208        } else if (data->import || data->bidi_import || data->export) {
 209                warning("This remote helper should implement refspec capability.");
 210        }
 211        strbuf_release(&buf);
 212        if (debug)
 213                fprintf(stderr, "Debug: Capabilities complete.\n");
 214        return data->helper;
 215}
 216
 217static int disconnect_helper(struct transport *transport)
 218{
 219        struct helper_data *data = transport->data;
 220        int res = 0;
 221
 222        if (data->helper) {
 223                if (debug)
 224                        fprintf(stderr, "Debug: Disconnecting.\n");
 225                if (!data->no_disconnect_req) {
 226                        /*
 227                         * Ignore write errors; there's nothing we can do,
 228                         * since we're about to close the pipe anyway. And the
 229                         * most likely error is EPIPE due to the helper dying
 230                         * to report an error itself.
 231                         */
 232                        sigchain_push(SIGPIPE, SIG_IGN);
 233                        xwrite(data->helper->in, "\n", 1);
 234                        sigchain_pop(SIGPIPE);
 235                }
 236                close(data->helper->in);
 237                close(data->helper->out);
 238                fclose(data->out);
 239                res = finish_command(data->helper);
 240                free(data->helper);
 241                data->helper = NULL;
 242        }
 243        return res;
 244}
 245
 246static const char *unsupported_options[] = {
 247        TRANS_OPT_UPLOADPACK,
 248        TRANS_OPT_RECEIVEPACK,
 249        TRANS_OPT_THIN,
 250        TRANS_OPT_KEEP
 251        };
 252
 253static const char *boolean_options[] = {
 254        TRANS_OPT_THIN,
 255        TRANS_OPT_KEEP,
 256        TRANS_OPT_FOLLOWTAGS,
 257        TRANS_OPT_PUSH_CERT
 258        };
 259
 260static int set_helper_option(struct transport *transport,
 261                          const char *name, const char *value)
 262{
 263        struct helper_data *data = transport->data;
 264        struct strbuf buf = STRBUF_INIT;
 265        int i, ret, is_bool = 0;
 266
 267        get_helper(transport);
 268
 269        if (!data->option)
 270                return 1;
 271
 272        for (i = 0; i < ARRAY_SIZE(unsupported_options); i++) {
 273                if (!strcmp(name, unsupported_options[i]))
 274                        return 1;
 275        }
 276
 277        for (i = 0; i < ARRAY_SIZE(boolean_options); i++) {
 278                if (!strcmp(name, boolean_options[i])) {
 279                        is_bool = 1;
 280                        break;
 281                }
 282        }
 283
 284        strbuf_addf(&buf, "option %s ", name);
 285        if (is_bool)
 286                strbuf_addstr(&buf, value ? "true" : "false");
 287        else
 288                quote_c_style(value, &buf, NULL, 0);
 289        strbuf_addch(&buf, '\n');
 290
 291        sendline(data, &buf);
 292        if (recvline(data, &buf))
 293                exit(128);
 294
 295        if (!strcmp(buf.buf, "ok"))
 296                ret = 0;
 297        else if (starts_with(buf.buf, "error")) {
 298                ret = -1;
 299        } else if (!strcmp(buf.buf, "unsupported"))
 300                ret = 1;
 301        else {
 302                warning("%s unexpectedly said: '%s'", data->name, buf.buf);
 303                ret = 1;
 304        }
 305        strbuf_release(&buf);
 306        return ret;
 307}
 308
 309static void standard_options(struct transport *t)
 310{
 311        char buf[16];
 312        int n;
 313        int v = t->verbose;
 314
 315        set_helper_option(t, "progress", t->progress ? "true" : "false");
 316
 317        n = snprintf(buf, sizeof(buf), "%d", v + 1);
 318        if (n >= sizeof(buf))
 319                die("impossibly large verbosity value");
 320        set_helper_option(t, "verbosity", buf);
 321}
 322
 323static int release_helper(struct transport *transport)
 324{
 325        int res = 0;
 326        struct helper_data *data = transport->data;
 327        free_refspec(data->refspec_nr, data->refspecs);
 328        data->refspecs = NULL;
 329        res = disconnect_helper(transport);
 330        free(transport->data);
 331        return res;
 332}
 333
 334static int fetch_with_fetch(struct transport *transport,
 335                            int nr_heads, struct ref **to_fetch)
 336{
 337        struct helper_data *data = transport->data;
 338        int i;
 339        struct strbuf buf = STRBUF_INIT;
 340
 341        standard_options(transport);
 342        if (data->check_connectivity &&
 343            data->transport_options.check_self_contained_and_connected)
 344                set_helper_option(transport, "check-connectivity", "true");
 345
 346        if (transport->cloning)
 347                set_helper_option(transport, "cloning", "true");
 348
 349        if (data->transport_options.update_shallow)
 350                set_helper_option(transport, "update-shallow", "true");
 351
 352        for (i = 0; i < nr_heads; i++) {
 353                const struct ref *posn = to_fetch[i];
 354                if (posn->status & REF_STATUS_UPTODATE)
 355                        continue;
 356
 357                strbuf_addf(&buf, "fetch %s %s\n",
 358                            sha1_to_hex(posn->old_sha1),
 359                            posn->symref ? posn->symref : 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",
 458                            posn->symref ? posn->symref : posn->name);
 459                sendline(data, &buf);
 460                strbuf_reset(&buf);
 461        }
 462
 463        write_constant(data->helper->in, "\n");
 464        /*
 465         * remote-helpers that advertise the bidi-import capability are required to
 466         * buffer the complete batch of import commands until this newline before
 467         * sending data to fast-import.
 468         * These helpers read back data from fast-import on their stdin, which could
 469         * be mixed with import commands, otherwise.
 470         */
 471
 472        if (finish_command(&fastimport))
 473                die("Error while running fast-import");
 474
 475        /*
 476         * The fast-import stream of a remote helper that advertises
 477         * the "refspec" capability writes to the refs named after the
 478         * right hand side of the first refspec matching each ref we
 479         * were fetching.
 480         *
 481         * (If no "refspec" capability was specified, for historical
 482         * reasons we default to the equivalent of *:*.)
 483         *
 484         * Store the result in to_fetch[i].old_sha1.  Callers such
 485         * as "git fetch" can use the value to write feedback to the
 486         * terminal, populate FETCH_HEAD, and determine what new value
 487         * should be written to peer_ref if the update is a
 488         * fast-forward or this is a forced update.
 489         */
 490        for (i = 0; i < nr_heads; i++) {
 491                char *private, *name;
 492                posn = to_fetch[i];
 493                if (posn->status & REF_STATUS_UPTODATE)
 494                        continue;
 495                name = posn->symref ? posn->symref : posn->name;
 496                if (data->refspecs)
 497                        private = apply_refspecs(data->refspecs, data->refspec_nr, name);
 498                else
 499                        private = xstrdup(name);
 500                if (private) {
 501                        read_ref(private, posn->old_sha1);
 502                        free(private);
 503                }
 504        }
 505        strbuf_release(&buf);
 506        return 0;
 507}
 508
 509static int process_connect_service(struct transport *transport,
 510                                   const char *name, const char *exec)
 511{
 512        struct helper_data *data = transport->data;
 513        struct strbuf cmdbuf = STRBUF_INIT;
 514        struct child_process *helper;
 515        int r, duped, ret = 0;
 516        FILE *input;
 517
 518        helper = get_helper(transport);
 519
 520        /*
 521         * Yes, dup the pipe another time, as we need unbuffered version
 522         * of input pipe as FILE*. fclose() closes the underlying fd and
 523         * stream buffering only can be changed before first I/O operation
 524         * on it.
 525         */
 526        duped = dup(helper->out);
 527        if (duped < 0)
 528                die_errno("Can't dup helper output fd");
 529        input = xfdopen(duped, "r");
 530        setvbuf(input, NULL, _IONBF, 0);
 531
 532        /*
 533         * Handle --upload-pack and friends. This is fire and forget...
 534         * just warn if it fails.
 535         */
 536        if (strcmp(name, exec)) {
 537                r = set_helper_option(transport, "servpath", exec);
 538                if (r > 0)
 539                        warning("Setting remote service path not supported by protocol.");
 540                else if (r < 0)
 541                        warning("Invalid remote service path.");
 542        }
 543
 544        if (data->connect)
 545                strbuf_addf(&cmdbuf, "connect %s\n", name);
 546        else
 547                goto exit;
 548
 549        sendline(data, &cmdbuf);
 550        if (recvline_fh(input, &cmdbuf, name))
 551                exit(128);
 552
 553        if (!strcmp(cmdbuf.buf, "")) {
 554                data->no_disconnect_req = 1;
 555                if (debug)
 556                        fprintf(stderr, "Debug: Smart transport connection "
 557                                "ready.\n");
 558                ret = 1;
 559        } else if (!strcmp(cmdbuf.buf, "fallback")) {
 560                if (debug)
 561                        fprintf(stderr, "Debug: Falling back to dumb "
 562                                "transport.\n");
 563        } else
 564                die("Unknown response to connect: %s",
 565                        cmdbuf.buf);
 566
 567exit:
 568        fclose(input);
 569        return ret;
 570}
 571
 572static int process_connect(struct transport *transport,
 573                                     int for_push)
 574{
 575        struct helper_data *data = transport->data;
 576        const char *name;
 577        const char *exec;
 578
 579        name = for_push ? "git-receive-pack" : "git-upload-pack";
 580        if (for_push)
 581                exec = data->transport_options.receivepack;
 582        else
 583                exec = data->transport_options.uploadpack;
 584
 585        return process_connect_service(transport, name, exec);
 586}
 587
 588static int connect_helper(struct transport *transport, const char *name,
 589                   const char *exec, int fd[2])
 590{
 591        struct helper_data *data = transport->data;
 592
 593        /* Get_helper so connect is inited. */
 594        get_helper(transport);
 595        if (!data->connect)
 596                die("Operation not supported by protocol.");
 597
 598        if (!process_connect_service(transport, name, exec))
 599                die("Can't connect to subservice %s.", name);
 600
 601        fd[0] = data->helper->out;
 602        fd[1] = data->helper->in;
 603        return 0;
 604}
 605
 606static int fetch(struct transport *transport,
 607                 int nr_heads, struct ref **to_fetch)
 608{
 609        struct helper_data *data = transport->data;
 610        int i, count;
 611
 612        if (process_connect(transport, 0)) {
 613                do_take_over(transport);
 614                return transport->fetch(transport, nr_heads, to_fetch);
 615        }
 616
 617        count = 0;
 618        for (i = 0; i < nr_heads; i++)
 619                if (!(to_fetch[i]->status & REF_STATUS_UPTODATE))
 620                        count++;
 621
 622        if (!count)
 623                return 0;
 624
 625        if (data->fetch)
 626                return fetch_with_fetch(transport, nr_heads, to_fetch);
 627
 628        if (data->import)
 629                return fetch_with_import(transport, nr_heads, to_fetch);
 630
 631        return -1;
 632}
 633
 634static int push_update_ref_status(struct strbuf *buf,
 635                                   struct ref **ref,
 636                                   struct ref *remote_refs)
 637{
 638        char *refname, *msg;
 639        int status, forced = 0;
 640
 641        if (starts_with(buf->buf, "ok ")) {
 642                status = REF_STATUS_OK;
 643                refname = buf->buf + 3;
 644        } else if (starts_with(buf->buf, "error ")) {
 645                status = REF_STATUS_REMOTE_REJECT;
 646                refname = buf->buf + 6;
 647        } else
 648                die("expected ok/error, helper said '%s'", buf->buf);
 649
 650        msg = strchr(refname, ' ');
 651        if (msg) {
 652                struct strbuf msg_buf = STRBUF_INIT;
 653                const char *end;
 654
 655                *msg++ = '\0';
 656                if (!unquote_c_style(&msg_buf, msg, &end))
 657                        msg = strbuf_detach(&msg_buf, NULL);
 658                else
 659                        msg = xstrdup(msg);
 660                strbuf_release(&msg_buf);
 661
 662                if (!strcmp(msg, "no match")) {
 663                        status = REF_STATUS_NONE;
 664                        free(msg);
 665                        msg = NULL;
 666                }
 667                else if (!strcmp(msg, "up to date")) {
 668                        status = REF_STATUS_UPTODATE;
 669                        free(msg);
 670                        msg = NULL;
 671                }
 672                else if (!strcmp(msg, "non-fast forward")) {
 673                        status = REF_STATUS_REJECT_NONFASTFORWARD;
 674                        free(msg);
 675                        msg = NULL;
 676                }
 677                else if (!strcmp(msg, "already exists")) {
 678                        status = REF_STATUS_REJECT_ALREADY_EXISTS;
 679                        free(msg);
 680                        msg = NULL;
 681                }
 682                else if (!strcmp(msg, "fetch first")) {
 683                        status = REF_STATUS_REJECT_FETCH_FIRST;
 684                        free(msg);
 685                        msg = NULL;
 686                }
 687                else if (!strcmp(msg, "needs force")) {
 688                        status = REF_STATUS_REJECT_NEEDS_FORCE;
 689                        free(msg);
 690                        msg = NULL;
 691                }
 692                else if (!strcmp(msg, "stale info")) {
 693                        status = REF_STATUS_REJECT_STALE;
 694                        free(msg);
 695                        msg = NULL;
 696                }
 697                else if (!strcmp(msg, "forced update")) {
 698                        forced = 1;
 699                        free(msg);
 700                        msg = NULL;
 701                }
 702        }
 703
 704        if (*ref)
 705                *ref = find_ref_by_name(*ref, refname);
 706        if (!*ref)
 707                *ref = find_ref_by_name(remote_refs, refname);
 708        if (!*ref) {
 709                warning("helper reported unexpected status of %s", refname);
 710                return 1;
 711        }
 712
 713        if ((*ref)->status != REF_STATUS_NONE) {
 714                /*
 715                 * Earlier, the ref was marked not to be pushed, so ignore the ref
 716                 * status reported by the remote helper if the latter is 'no match'.
 717                 */
 718                if (status == REF_STATUS_NONE)
 719                        return 1;
 720        }
 721
 722        (*ref)->status = status;
 723        (*ref)->forced_update |= forced;
 724        (*ref)->remote_status = msg;
 725        return !(status == REF_STATUS_OK);
 726}
 727
 728static int push_update_refs_status(struct helper_data *data,
 729                                    struct ref *remote_refs,
 730                                    int flags)
 731{
 732        struct strbuf buf = STRBUF_INIT;
 733        struct ref *ref = remote_refs;
 734        int ret = 0;
 735
 736        for (;;) {
 737                char *private;
 738
 739                if (recvline(data, &buf)) {
 740                        ret = 1;
 741                        break;
 742                }
 743
 744                if (!buf.len)
 745                        break;
 746
 747                if (push_update_ref_status(&buf, &ref, remote_refs))
 748                        continue;
 749
 750                if (flags & TRANSPORT_PUSH_DRY_RUN || !data->refspecs || data->no_private_update)
 751                        continue;
 752
 753                /* propagate back the update to the remote namespace */
 754                private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
 755                if (!private)
 756                        continue;
 757                update_ref("update by helper", private, ref->new_sha1, NULL, 0, 0);
 758                free(private);
 759        }
 760        strbuf_release(&buf);
 761        return ret;
 762}
 763
 764static int push_refs_with_push(struct transport *transport,
 765                               struct ref *remote_refs, int flags)
 766{
 767        int force_all = flags & TRANSPORT_PUSH_FORCE;
 768        int mirror = flags & TRANSPORT_PUSH_MIRROR;
 769        struct helper_data *data = transport->data;
 770        struct strbuf buf = STRBUF_INIT;
 771        struct ref *ref;
 772        struct string_list cas_options = STRING_LIST_INIT_DUP;
 773        struct string_list_item *cas_option;
 774
 775        get_helper(transport);
 776        if (!data->push)
 777                return 1;
 778
 779        for (ref = remote_refs; ref; ref = ref->next) {
 780                if (!ref->peer_ref && !mirror)
 781                        continue;
 782
 783                /* Check for statuses set by set_ref_status_for_push() */
 784                switch (ref->status) {
 785                case REF_STATUS_REJECT_NONFASTFORWARD:
 786                case REF_STATUS_REJECT_STALE:
 787                case REF_STATUS_REJECT_ALREADY_EXISTS:
 788                case REF_STATUS_UPTODATE:
 789                        continue;
 790                default:
 791                        ; /* do nothing */
 792                }
 793
 794                if (force_all)
 795                        ref->force = 1;
 796
 797                strbuf_addstr(&buf, "push ");
 798                if (!ref->deletion) {
 799                        if (ref->force)
 800                                strbuf_addch(&buf, '+');
 801                        if (ref->peer_ref)
 802                                strbuf_addstr(&buf, ref->peer_ref->name);
 803                        else
 804                                strbuf_addstr(&buf, sha1_to_hex(ref->new_sha1));
 805                }
 806                strbuf_addch(&buf, ':');
 807                strbuf_addstr(&buf, ref->name);
 808                strbuf_addch(&buf, '\n');
 809
 810                /*
 811                 * The "--force-with-lease" options without explicit
 812                 * values to expect have already been expanded into
 813                 * the ref->old_sha1_expect[] field; we can ignore
 814                 * transport->smart_options->cas altogether and instead
 815                 * can enumerate them from the refs.
 816                 */
 817                if (ref->expect_old_sha1) {
 818                        struct strbuf cas = STRBUF_INIT;
 819                        strbuf_addf(&cas, "%s:%s",
 820                                    ref->name, sha1_to_hex(ref->old_sha1_expect));
 821                        string_list_append(&cas_options, strbuf_detach(&cas, NULL));
 822                }
 823        }
 824        if (buf.len == 0) {
 825                string_list_clear(&cas_options, 0);
 826                return 0;
 827        }
 828
 829        standard_options(transport);
 830        for_each_string_list_item(cas_option, &cas_options)
 831                set_helper_option(transport, "cas", cas_option->string);
 832
 833        if (flags & TRANSPORT_PUSH_DRY_RUN) {
 834                if (set_helper_option(transport, "dry-run", "true") != 0)
 835                        die("helper %s does not support dry-run", data->name);
 836        } else if (flags & TRANSPORT_PUSH_CERT) {
 837                if (set_helper_option(transport, TRANS_OPT_PUSH_CERT, "true") != 0)
 838                        die("helper %s does not support --signed", data->name);
 839        }
 840
 841        strbuf_addch(&buf, '\n');
 842        sendline(data, &buf);
 843        strbuf_release(&buf);
 844
 845        return push_update_refs_status(data, remote_refs, flags);
 846}
 847
 848static int push_refs_with_export(struct transport *transport,
 849                struct ref *remote_refs, int flags)
 850{
 851        struct ref *ref;
 852        struct child_process *helper, exporter;
 853        struct helper_data *data = transport->data;
 854        struct string_list revlist_args = STRING_LIST_INIT_DUP;
 855        struct strbuf buf = STRBUF_INIT;
 856
 857        if (!data->refspecs)
 858                die("remote-helper doesn't support push; refspec needed");
 859
 860        if (flags & TRANSPORT_PUSH_DRY_RUN) {
 861                if (set_helper_option(transport, "dry-run", "true") != 0)
 862                        die("helper %s does not support dry-run", data->name);
 863        } else if (flags & TRANSPORT_PUSH_CERT) {
 864                if (set_helper_option(transport, TRANS_OPT_PUSH_CERT, "true") != 0)
 865                        die("helper %s does not support --signed", data->name);
 866        }
 867
 868        if (flags & TRANSPORT_PUSH_FORCE) {
 869                if (set_helper_option(transport, "force", "true") != 0)
 870                        warning("helper %s does not support 'force'", data->name);
 871        }
 872
 873        helper = get_helper(transport);
 874
 875        write_constant(helper->in, "export\n");
 876
 877        for (ref = remote_refs; ref; ref = ref->next) {
 878                char *private;
 879                unsigned char sha1[20];
 880
 881                private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
 882                if (private && !get_sha1(private, sha1)) {
 883                        strbuf_addf(&buf, "^%s", private);
 884                        string_list_append(&revlist_args, strbuf_detach(&buf, NULL));
 885                        hashcpy(ref->old_sha1, sha1);
 886                }
 887                free(private);
 888
 889                if (ref->peer_ref) {
 890                        if (strcmp(ref->name, ref->peer_ref->name)) {
 891                                if (!ref->deletion) {
 892                                        const char *name;
 893                                        int flag;
 894
 895                                        /* Follow symbolic refs (mainly for HEAD). */
 896                                        name = resolve_ref_unsafe(
 897                                                 ref->peer_ref->name,
 898                                                 RESOLVE_REF_READING,
 899                                                 sha1, &flag);
 900                                        if (!name || !(flag & REF_ISSYMREF))
 901                                                name = ref->peer_ref->name;
 902
 903                                        strbuf_addf(&buf, "%s:%s", name, ref->name);
 904                                } else
 905                                        strbuf_addf(&buf, ":%s", ref->name);
 906
 907                                string_list_append(&revlist_args, "--refspec");
 908                                string_list_append(&revlist_args, buf.buf);
 909                                strbuf_release(&buf);
 910                        }
 911                        if (!ref->deletion)
 912                                string_list_append(&revlist_args, ref->peer_ref->name);
 913                }
 914        }
 915
 916        if (get_exporter(transport, &exporter, &revlist_args))
 917                die("Couldn't run fast-export");
 918
 919        string_list_clear(&revlist_args, 1);
 920
 921        if (finish_command(&exporter))
 922                die("Error while running fast-export");
 923        if (push_update_refs_status(data, remote_refs, flags))
 924                return 1;
 925
 926        if (data->export_marks) {
 927                strbuf_addf(&buf, "%s.tmp", data->export_marks);
 928                rename(buf.buf, data->export_marks);
 929                strbuf_release(&buf);
 930        }
 931
 932        return 0;
 933}
 934
 935static int push_refs(struct transport *transport,
 936                struct ref *remote_refs, int flags)
 937{
 938        struct helper_data *data = transport->data;
 939
 940        if (process_connect(transport, 1)) {
 941                do_take_over(transport);
 942                return transport->push_refs(transport, remote_refs, flags);
 943        }
 944
 945        if (!remote_refs) {
 946                fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
 947                        "Perhaps you should specify a branch such as 'master'.\n");
 948                return 0;
 949        }
 950
 951        if (data->push)
 952                return push_refs_with_push(transport, remote_refs, flags);
 953
 954        if (data->export)
 955                return push_refs_with_export(transport, remote_refs, flags);
 956
 957        return -1;
 958}
 959
 960
 961static int has_attribute(const char *attrs, const char *attr) {
 962        int len;
 963        if (!attrs)
 964                return 0;
 965
 966        len = strlen(attr);
 967        for (;;) {
 968                const char *space = strchrnul(attrs, ' ');
 969                if (len == space - attrs && !strncmp(attrs, attr, len))
 970                        return 1;
 971                if (!*space)
 972                        return 0;
 973                attrs = space + 1;
 974        }
 975}
 976
 977static struct ref *get_refs_list(struct transport *transport, int for_push)
 978{
 979        struct helper_data *data = transport->data;
 980        struct child_process *helper;
 981        struct ref *ret = NULL;
 982        struct ref **tail = &ret;
 983        struct ref *posn;
 984        struct strbuf buf = STRBUF_INIT;
 985
 986        helper = get_helper(transport);
 987
 988        if (process_connect(transport, for_push)) {
 989                do_take_over(transport);
 990                return transport->get_refs_list(transport, for_push);
 991        }
 992
 993        if (data->push && for_push)
 994                write_str_in_full(helper->in, "list for-push\n");
 995        else
 996                write_str_in_full(helper->in, "list\n");
 997
 998        while (1) {
 999                char *eov, *eon;
1000                if (recvline(data, &buf))
1001                        exit(128);
1002
1003                if (!*buf.buf)
1004                        break;
1005
1006                eov = strchr(buf.buf, ' ');
1007                if (!eov)
1008                        die("Malformed response in ref list: %s", buf.buf);
1009                eon = strchr(eov + 1, ' ');
1010                *eov = '\0';
1011                if (eon)
1012                        *eon = '\0';
1013                *tail = alloc_ref(eov + 1);
1014                if (buf.buf[0] == '@')
1015                        (*tail)->symref = xstrdup(buf.buf + 1);
1016                else if (buf.buf[0] != '?')
1017                        get_sha1_hex(buf.buf, (*tail)->old_sha1);
1018                if (eon) {
1019                        if (has_attribute(eon + 1, "unchanged")) {
1020                                (*tail)->status |= REF_STATUS_UPTODATE;
1021                                read_ref((*tail)->name, (*tail)->old_sha1);
1022                        }
1023                }
1024                tail = &((*tail)->next);
1025        }
1026        if (debug)
1027                fprintf(stderr, "Debug: Read ref listing.\n");
1028        strbuf_release(&buf);
1029
1030        for (posn = ret; posn; posn = posn->next)
1031                resolve_remote_symref(posn, ret);
1032
1033        return ret;
1034}
1035
1036int transport_helper_init(struct transport *transport, const char *name)
1037{
1038        struct helper_data *data = xcalloc(1, sizeof(*data));
1039        data->name = name;
1040
1041        if (getenv("GIT_TRANSPORT_HELPER_DEBUG"))
1042                debug = 1;
1043
1044        transport->data = data;
1045        transport->set_option = set_helper_option;
1046        transport->get_refs_list = get_refs_list;
1047        transport->fetch = fetch;
1048        transport->push_refs = push_refs;
1049        transport->disconnect = release_helper;
1050        transport->connect = connect_helper;
1051        transport->smart_options = &(data->transport_options);
1052        return 0;
1053}
1054
1055/*
1056 * Linux pipes can buffer 65536 bytes at once (and most platforms can
1057 * buffer less), so attempt reads and writes with up to that size.
1058 */
1059#define BUFFERSIZE 65536
1060/* This should be enough to hold debugging message. */
1061#define PBUFFERSIZE 8192
1062
1063/* Print bidirectional transfer loop debug message. */
1064__attribute__((format (printf, 1, 2)))
1065static void transfer_debug(const char *fmt, ...)
1066{
1067        va_list args;
1068        char msgbuf[PBUFFERSIZE];
1069        static int debug_enabled = -1;
1070
1071        if (debug_enabled < 0)
1072                debug_enabled = getenv("GIT_TRANSLOOP_DEBUG") ? 1 : 0;
1073        if (!debug_enabled)
1074                return;
1075
1076        va_start(args, fmt);
1077        vsnprintf(msgbuf, PBUFFERSIZE, fmt, args);
1078        va_end(args);
1079        fprintf(stderr, "Transfer loop debugging: %s\n", msgbuf);
1080}
1081
1082/* Stream state: More data may be coming in this direction. */
1083#define SSTATE_TRANSFERING 0
1084/*
1085 * Stream state: No more data coming in this direction, flushing rest of
1086 * data.
1087 */
1088#define SSTATE_FLUSHING 1
1089/* Stream state: Transfer in this direction finished. */
1090#define SSTATE_FINISHED 2
1091
1092#define STATE_NEEDS_READING(state) ((state) <= SSTATE_TRANSFERING)
1093#define STATE_NEEDS_WRITING(state) ((state) <= SSTATE_FLUSHING)
1094#define STATE_NEEDS_CLOSING(state) ((state) == SSTATE_FLUSHING)
1095
1096/* Unidirectional transfer. */
1097struct unidirectional_transfer {
1098        /* Source */
1099        int src;
1100        /* Destination */
1101        int dest;
1102        /* Is source socket? */
1103        int src_is_sock;
1104        /* Is destination socket? */
1105        int dest_is_sock;
1106        /* Transfer state (TRANSFERRING/FLUSHING/FINISHED) */
1107        int state;
1108        /* Buffer. */
1109        char buf[BUFFERSIZE];
1110        /* Buffer used. */
1111        size_t bufuse;
1112        /* Name of source. */
1113        const char *src_name;
1114        /* Name of destination. */
1115        const char *dest_name;
1116};
1117
1118/* Closes the target (for writing) if transfer has finished. */
1119static void udt_close_if_finished(struct unidirectional_transfer *t)
1120{
1121        if (STATE_NEEDS_CLOSING(t->state) && !t->bufuse) {
1122                t->state = SSTATE_FINISHED;
1123                if (t->dest_is_sock)
1124                        shutdown(t->dest, SHUT_WR);
1125                else
1126                        close(t->dest);
1127                transfer_debug("Closed %s.", t->dest_name);
1128        }
1129}
1130
1131/*
1132 * Tries to read read data from source into buffer. If buffer is full,
1133 * no data is read. Returns 0 on success, -1 on error.
1134 */
1135static int udt_do_read(struct unidirectional_transfer *t)
1136{
1137        ssize_t bytes;
1138
1139        if (t->bufuse == BUFFERSIZE)
1140                return 0;       /* No space for more. */
1141
1142        transfer_debug("%s is readable", t->src_name);
1143        bytes = read(t->src, t->buf + t->bufuse, BUFFERSIZE - t->bufuse);
1144        if (bytes < 0 && errno != EWOULDBLOCK && errno != EAGAIN &&
1145                errno != EINTR) {
1146                error("read(%s) failed: %s", t->src_name, strerror(errno));
1147                return -1;
1148        } else if (bytes == 0) {
1149                transfer_debug("%s EOF (with %i bytes in buffer)",
1150                        t->src_name, (int)t->bufuse);
1151                t->state = SSTATE_FLUSHING;
1152        } else if (bytes > 0) {
1153                t->bufuse += bytes;
1154                transfer_debug("Read %i bytes from %s (buffer now at %i)",
1155                        (int)bytes, t->src_name, (int)t->bufuse);
1156        }
1157        return 0;
1158}
1159
1160/* Tries to write data from buffer into destination. If buffer is empty,
1161 * no data is written. Returns 0 on success, -1 on error.
1162 */
1163static int udt_do_write(struct unidirectional_transfer *t)
1164{
1165        ssize_t bytes;
1166
1167        if (t->bufuse == 0)
1168                return 0;       /* Nothing to write. */
1169
1170        transfer_debug("%s is writable", t->dest_name);
1171        bytes = xwrite(t->dest, t->buf, t->bufuse);
1172        if (bytes < 0 && errno != EWOULDBLOCK) {
1173                error("write(%s) failed: %s", t->dest_name, strerror(errno));
1174                return -1;
1175        } else if (bytes > 0) {
1176                t->bufuse -= bytes;
1177                if (t->bufuse)
1178                        memmove(t->buf, t->buf + bytes, t->bufuse);
1179                transfer_debug("Wrote %i bytes to %s (buffer now at %i)",
1180                        (int)bytes, t->dest_name, (int)t->bufuse);
1181        }
1182        return 0;
1183}
1184
1185
1186/* State of bidirectional transfer loop. */
1187struct bidirectional_transfer_state {
1188        /* Direction from program to git. */
1189        struct unidirectional_transfer ptg;
1190        /* Direction from git to program. */
1191        struct unidirectional_transfer gtp;
1192};
1193
1194static void *udt_copy_task_routine(void *udt)
1195{
1196        struct unidirectional_transfer *t = (struct unidirectional_transfer *)udt;
1197        while (t->state != SSTATE_FINISHED) {
1198                if (STATE_NEEDS_READING(t->state))
1199                        if (udt_do_read(t))
1200                                return NULL;
1201                if (STATE_NEEDS_WRITING(t->state))
1202                        if (udt_do_write(t))
1203                                return NULL;
1204                if (STATE_NEEDS_CLOSING(t->state))
1205                        udt_close_if_finished(t);
1206        }
1207        return udt;     /* Just some non-NULL value. */
1208}
1209
1210#ifndef NO_PTHREADS
1211
1212/*
1213 * Join thread, with appropriate errors on failure. Name is name for the
1214 * thread (for error messages). Returns 0 on success, 1 on failure.
1215 */
1216static int tloop_join(pthread_t thread, const char *name)
1217{
1218        int err;
1219        void *tret;
1220        err = pthread_join(thread, &tret);
1221        if (!tret) {
1222                error("%s thread failed", name);
1223                return 1;
1224        }
1225        if (err) {
1226                error("%s thread failed to join: %s", name, strerror(err));
1227                return 1;
1228        }
1229        return 0;
1230}
1231
1232/*
1233 * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1234 * -1 on failure.
1235 */
1236static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1237{
1238        pthread_t gtp_thread;
1239        pthread_t ptg_thread;
1240        int err;
1241        int ret = 0;
1242        err = pthread_create(&gtp_thread, NULL, udt_copy_task_routine,
1243                &s->gtp);
1244        if (err)
1245                die("Can't start thread for copying data: %s", strerror(err));
1246        err = pthread_create(&ptg_thread, NULL, udt_copy_task_routine,
1247                &s->ptg);
1248        if (err)
1249                die("Can't start thread for copying data: %s", strerror(err));
1250
1251        ret |= tloop_join(gtp_thread, "Git to program copy");
1252        ret |= tloop_join(ptg_thread, "Program to git copy");
1253        return ret;
1254}
1255#else
1256
1257/* Close the source and target (for writing) for transfer. */
1258static void udt_kill_transfer(struct unidirectional_transfer *t)
1259{
1260        t->state = SSTATE_FINISHED;
1261        /*
1262         * Socket read end left open isn't a disaster if nobody
1263         * attempts to read from it (mingw compat headers do not
1264         * have SHUT_RD)...
1265         *
1266         * We can't fully close the socket since otherwise gtp
1267         * task would first close the socket it sends data to
1268         * while closing the ptg file descriptors.
1269         */
1270        if (!t->src_is_sock)
1271                close(t->src);
1272        if (t->dest_is_sock)
1273                shutdown(t->dest, SHUT_WR);
1274        else
1275                close(t->dest);
1276}
1277
1278/*
1279 * Join process, with appropriate errors on failure. Name is name for the
1280 * process (for error messages). Returns 0 on success, 1 on failure.
1281 */
1282static int tloop_join(pid_t pid, const char *name)
1283{
1284        int tret;
1285        if (waitpid(pid, &tret, 0) < 0) {
1286                error("%s process failed to wait: %s", name, strerror(errno));
1287                return 1;
1288        }
1289        if (!WIFEXITED(tret) || WEXITSTATUS(tret)) {
1290                error("%s process failed", name);
1291                return 1;
1292        }
1293        return 0;
1294}
1295
1296/*
1297 * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1298 * -1 on failure.
1299 */
1300static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1301{
1302        pid_t pid1, pid2;
1303        int ret = 0;
1304
1305        /* Fork thread #1: git to program. */
1306        pid1 = fork();
1307        if (pid1 < 0)
1308                die_errno("Can't start thread for copying data");
1309        else if (pid1 == 0) {
1310                udt_kill_transfer(&s->ptg);
1311                exit(udt_copy_task_routine(&s->gtp) ? 0 : 1);
1312        }
1313
1314        /* Fork thread #2: program to git. */
1315        pid2 = fork();
1316        if (pid2 < 0)
1317                die_errno("Can't start thread for copying data");
1318        else if (pid2 == 0) {
1319                udt_kill_transfer(&s->gtp);
1320                exit(udt_copy_task_routine(&s->ptg) ? 0 : 1);
1321        }
1322
1323        /*
1324         * Close both streams in parent as to not interfere with
1325         * end of file detection and wait for both tasks to finish.
1326         */
1327        udt_kill_transfer(&s->gtp);
1328        udt_kill_transfer(&s->ptg);
1329        ret |= tloop_join(pid1, "Git to program copy");
1330        ret |= tloop_join(pid2, "Program to git copy");
1331        return ret;
1332}
1333#endif
1334
1335/*
1336 * Copies data from stdin to output and from input to stdout simultaneously.
1337 * Additionally filtering through given filter. If filter is NULL, uses
1338 * identity filter.
1339 */
1340int bidirectional_transfer_loop(int input, int output)
1341{
1342        struct bidirectional_transfer_state state;
1343
1344        /* Fill the state fields. */
1345        state.ptg.src = input;
1346        state.ptg.dest = 1;
1347        state.ptg.src_is_sock = (input == output);
1348        state.ptg.dest_is_sock = 0;
1349        state.ptg.state = SSTATE_TRANSFERING;
1350        state.ptg.bufuse = 0;
1351        state.ptg.src_name = "remote input";
1352        state.ptg.dest_name = "stdout";
1353
1354        state.gtp.src = 0;
1355        state.gtp.dest = output;
1356        state.gtp.src_is_sock = 0;
1357        state.gtp.dest_is_sock = (input == output);
1358        state.gtp.state = SSTATE_TRANSFERING;
1359        state.gtp.bufuse = 0;
1360        state.gtp.src_name = "stdin";
1361        state.gtp.dest_name = "remote output";
1362
1363        return tloop_spawnwait_tasks(&state);
1364}