git.oblomov.eu Git - git/blob - transport-helper.c

   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 #include "refspec.h"
  15 #include "transport-internal.h"
  16 #include "protocol.h"
  17
  18 static int debug;
  19
  20 struct helper_data {
  21         const char *name;
  22         struct child_process *helper;
  23         FILE *out;
  24         unsigned fetch : 1,
  25                 import : 1,
  26                 bidi_import : 1,
  27                 export : 1,
  28                 option : 1,
  29                 push : 1,
  30                 connect : 1,
  31                 stateless_connect : 1,
  32                 signed_tags : 1,
  33                 check_connectivity : 1,
  34                 no_disconnect_req : 1,
  35                 no_private_update : 1;
  36         char *export_marks;
  37         char *import_marks;
  38         /* These go from remote name (as in "list") to private name */
  39         struct refspec rs;
  40         /* Transport options for fetch-pack/send-pack (should one of
  41          * those be invoked).
  42          */
  43         struct git_transport_options transport_options;
  44 };
  45
  46 static void sendline(struct helper_data *helper, struct strbuf *buffer)
  47 {
  48         if (debug)
  49                 fprintf(stderr, "Debug: Remote helper: -> %s", buffer->buf);
  50         if (write_in_full(helper->helper->in, buffer->buf, buffer->len) < 0)
  51                 die_errno(_("full write to remote helper failed"));
  52 }
  53
  54 static int recvline_fh(FILE *helper, struct strbuf *buffer)
  55 {
  56         strbuf_reset(buffer);
  57         if (debug)
  58                 fprintf(stderr, "Debug: Remote helper: Waiting...\n");
  59         if (strbuf_getline(buffer, helper) == EOF) {
  60                 if (debug)
  61                         fprintf(stderr, "Debug: Remote helper quit.\n");
  62                 return 1;
  63         }
  64
  65         if (debug)
  66                 fprintf(stderr, "Debug: Remote helper: <- %s\n", buffer->buf);
  67         return 0;
  68 }
  69
  70 static int recvline(struct helper_data *helper, struct strbuf *buffer)
  71 {
  72         return recvline_fh(helper->out, buffer);
  73 }
  74
  75 static void write_constant(int fd, const char *str)
  76 {
  77         if (debug)
  78                 fprintf(stderr, "Debug: Remote helper: -> %s", str);
  79         if (write_in_full(fd, str, strlen(str)) < 0)
  80                 die_errno(_("full write to remote helper failed"));
  81 }
  82
  83 static const char *remove_ext_force(const char *url)
  84 {
  85         if (url) {
  86                 const char *colon = strchr(url, ':');
  87                 if (colon && colon[1] == ':')
  88                         return colon + 2;
  89         }
  90         return url;
  91 }
  92
  93 static void do_take_over(struct transport *transport)
  94 {
  95         struct helper_data *data;
  96         data = (struct helper_data *)transport->data;
  97         transport_take_over(transport, data->helper);
  98         fclose(data->out);
  99         free(data);
 100 }
 101
 102 static void standard_options(struct transport *t);
 103
 104 static struct child_process *get_helper(struct transport *transport)
 105 {
 106         struct helper_data *data = transport->data;
 107         struct strbuf buf = STRBUF_INIT;
 108         struct child_process *helper;
 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         if (have_git_dir())
 127                 argv_array_pushf(&helper->env_array, "%s=%s",
 128                                  GIT_DIR_ENVIRONMENT, get_git_dir());
 129
 130         code = start_command(helper);
 131         if (code < 0 && errno == ENOENT)
 132                 die(_("unable to find remote helper for '%s'"), data->name);
 133         else if (code != 0)
 134                 exit(code);
 135
 136         data->helper = helper;
 137         data->no_disconnect_req = 0;
 138         refspec_init(&data->rs, REFSPEC_FETCH);
 139
 140         /*
 141          * Open the output as FILE* so strbuf_getline_*() family of
 142          * functions can be used.
 143          * Do this with duped fd because fclose() will close the fd,
 144          * and stuff like taking over will require the fd to remain.
 145          */
 146         duped = dup(helper->out);
 147         if (duped < 0)
 148                 die_errno(_("can't dup helper output fd"));
 149         data->out = xfdopen(duped, "r");
 150
 151         write_constant(helper->in, "capabilities\n");
 152
 153         while (1) {
 154                 const char *capname, *arg;
 155                 int mandatory = 0;
 156                 if (recvline(data, &buf))
 157                         exit(128);
 158
 159                 if (!*buf.buf)
 160                         break;
 161
 162                 if (*buf.buf == '*') {
 163                         capname = buf.buf + 1;
 164                         mandatory = 1;
 165                 } else
 166                         capname = buf.buf;
 167
 168                 if (debug)
 169                         fprintf(stderr, "Debug: Got cap %s\n", capname);
 170                 if (!strcmp(capname, "fetch"))
 171                         data->fetch = 1;
 172                 else if (!strcmp(capname, "option"))
 173                         data->option = 1;
 174                 else if (!strcmp(capname, "push"))
 175                         data->push = 1;
 176                 else if (!strcmp(capname, "import"))
 177                         data->import = 1;
 178                 else if (!strcmp(capname, "bidi-import"))
 179                         data->bidi_import = 1;
 180                 else if (!strcmp(capname, "export"))
 181                         data->export = 1;
 182                 else if (!strcmp(capname, "check-connectivity"))
 183                         data->check_connectivity = 1;
 184                 else if (skip_prefix(capname, "refspec ", &arg)) {
 185                         refspec_append(&data->rs, arg);
 186                 } else if (!strcmp(capname, "connect")) {
 187                         data->connect = 1;
 188                 } else if (!strcmp(capname, "stateless-connect")) {
 189                         data->stateless_connect = 1;
 190                 } else if (!strcmp(capname, "signed-tags")) {
 191                         data->signed_tags = 1;
 192                 } else if (skip_prefix(capname, "export-marks ", &arg)) {
 193                         data->export_marks = xstrdup(arg);
 194                 } else if (skip_prefix(capname, "import-marks ", &arg)) {
 195                         data->import_marks = xstrdup(arg);
 196                 } else if (starts_with(capname, "no-private-update")) {
 197                         data->no_private_update = 1;
 198                 } else if (mandatory) {
 199                         die(_("unknown mandatory capability %s; this remote "
 200                               "helper probably needs newer version of Git"),
 201                             capname);
 202                 }
 203         }
 204         if (!data->rs.nr && (data->import || data->bidi_import || data->export)) {
 205                 warning(_("this remote helper should implement refspec capability"));
 206         }
 207         strbuf_release(&buf);
 208         if (debug)
 209                 fprintf(stderr, "Debug: Capabilities complete.\n");
 210         standard_options(transport);
 211         return data->helper;
 212 }
 213
 214 static int disconnect_helper(struct transport *transport)
 215 {
 216         struct helper_data *data = transport->data;
 217         int res = 0;
 218
 219         if (data->helper) {
 220                 if (debug)
 221                         fprintf(stderr, "Debug: Disconnecting.\n");
 222                 if (!data->no_disconnect_req) {
 223                         /*
 224                          * Ignore write errors; there's nothing we can do,
 225                          * since we're about to close the pipe anyway. And the
 226                          * most likely error is EPIPE due to the helper dying
 227                          * to report an error itself.
 228                          */
 229                         sigchain_push(SIGPIPE, SIG_IGN);
 230                         xwrite(data->helper->in, "\n", 1);
 231                         sigchain_pop(SIGPIPE);
 232                 }
 233                 close(data->helper->in);
 234                 close(data->helper->out);
 235                 fclose(data->out);
 236                 res = finish_command(data->helper);
 237                 FREE_AND_NULL(data->helper);
 238         }
 239         return res;
 240 }
 241
 242 static const char *unsupported_options[] = {
 243         TRANS_OPT_UPLOADPACK,
 244         TRANS_OPT_RECEIVEPACK,
 245         TRANS_OPT_THIN,
 246         TRANS_OPT_KEEP
 247         };
 248
 249 static const char *boolean_options[] = {
 250         TRANS_OPT_THIN,
 251         TRANS_OPT_KEEP,
 252         TRANS_OPT_FOLLOWTAGS,
 253         TRANS_OPT_DEEPEN_RELATIVE
 254         };
 255
 256 static int strbuf_set_helper_option(struct helper_data *data,
 257                                     struct strbuf *buf)
 258 {
 259         int ret;
 260
 261         sendline(data, buf);
 262         if (recvline(data, buf))
 263                 exit(128);
 264
 265         if (!strcmp(buf->buf, "ok"))
 266                 ret = 0;
 267         else if (starts_with(buf->buf, "error"))
 268                 ret = -1;
 269         else if (!strcmp(buf->buf, "unsupported"))
 270                 ret = 1;
 271         else {
 272                 warning(_("%s unexpectedly said: '%s'"), data->name, buf->buf);
 273                 ret = 1;
 274         }
 275         return ret;
 276 }
 277
 278 static int string_list_set_helper_option(struct helper_data *data,
 279                                          const char *name,
 280                                          struct string_list *list)
 281 {
 282         struct strbuf buf = STRBUF_INIT;
 283         int i, ret = 0;
 284
 285         for (i = 0; i < list->nr; i++) {
 286                 strbuf_addf(&buf, "option %s ", name);
 287                 quote_c_style(list->items[i].string, &buf, NULL, 0);
 288                 strbuf_addch(&buf, '\n');
 289
 290                 if ((ret = strbuf_set_helper_option(data, &buf)))
 291                         break;
 292                 strbuf_reset(&buf);
 293         }
 294         strbuf_release(&buf);
 295         return ret;
 296 }
 297
 298 static int set_helper_option(struct transport *transport,
 299                           const char *name, const char *value)
 300 {
 301         struct helper_data *data = transport->data;
 302         struct strbuf buf = STRBUF_INIT;
 303         int i, ret, is_bool = 0;
 304
 305         get_helper(transport);
 306
 307         if (!data->option)
 308                 return 1;
 309
 310         if (!strcmp(name, "deepen-not"))
 311                 return string_list_set_helper_option(data, name,
 312                                                      (struct string_list *)value);
 313
 314         for (i = 0; i < ARRAY_SIZE(unsupported_options); i++) {
 315                 if (!strcmp(name, unsupported_options[i]))
 316                         return 1;
 317         }
 318
 319         for (i = 0; i < ARRAY_SIZE(boolean_options); i++) {
 320                 if (!strcmp(name, boolean_options[i])) {
 321                         is_bool = 1;
 322                         break;
 323                 }
 324         }
 325
 326         strbuf_addf(&buf, "option %s ", name);
 327         if (is_bool)
 328                 strbuf_addstr(&buf, value ? "true" : "false");
 329         else
 330                 quote_c_style(value, &buf, NULL, 0);
 331         strbuf_addch(&buf, '\n');
 332
 333         ret = strbuf_set_helper_option(data, &buf);
 334         strbuf_release(&buf);
 335         return ret;
 336 }
 337
 338 static void standard_options(struct transport *t)
 339 {
 340         char buf[16];
 341         int v = t->verbose;
 342
 343         set_helper_option(t, "progress", t->progress ? "true" : "false");
 344
 345         xsnprintf(buf, sizeof(buf), "%d", v + 1);
 346         set_helper_option(t, "verbosity", buf);
 347
 348         switch (t->family) {
 349         case TRANSPORT_FAMILY_ALL:
 350                 /*
 351                  * this is already the default,
 352                  * do not break old remote helpers by setting "all" here
 353                  */
 354                 break;
 355         case TRANSPORT_FAMILY_IPV4:
 356                 set_helper_option(t, "family", "ipv4");
 357                 break;
 358         case TRANSPORT_FAMILY_IPV6:
 359                 set_helper_option(t, "family", "ipv6");
 360                 break;
 361         }
 362 }
 363
 364 static int release_helper(struct transport *transport)
 365 {
 366         int res = 0;
 367         struct helper_data *data = transport->data;
 368         refspec_clear(&data->rs);
 369         res = disconnect_helper(transport);
 370         free(transport->data);
 371         return res;
 372 }
 373
 374 static int fetch_with_fetch(struct transport *transport,
 375                             int nr_heads, struct ref **to_fetch)
 376 {
 377         struct helper_data *data = transport->data;
 378         int i;
 379         struct strbuf buf = STRBUF_INIT;
 380
 381         for (i = 0; i < nr_heads; i++) {
 382                 const struct ref *posn = to_fetch[i];
 383                 if (posn->status & REF_STATUS_UPTODATE)
 384                         continue;
 385
 386                 strbuf_addf(&buf, "fetch %s %s\n",
 387                             oid_to_hex(&posn->old_oid),
 388                             posn->symref ? posn->symref : posn->name);
 389         }
 390
 391         strbuf_addch(&buf, '\n');
 392         sendline(data, &buf);
 393
 394         while (1) {
 395                 if (recvline(data, &buf))
 396                         exit(128);
 397
 398                 if (starts_with(buf.buf, "lock ")) {
 399                         const char *name = buf.buf + 5;
 400                         if (transport->pack_lockfile)
 401                                 warning(_("%s also locked %s"), data->name, name);
 402                         else
 403                                 transport->pack_lockfile = xstrdup(name);
 404                 }
 405                 else if (data->check_connectivity &&
 406                          data->transport_options.check_self_contained_and_connected &&
 407                          !strcmp(buf.buf, "connectivity-ok"))
 408                         data->transport_options.self_contained_and_connected = 1;
 409                 else if (!buf.len)
 410                         break;
 411                 else
 412                         warning(_("%s unexpectedly said: '%s'"), data->name, buf.buf);
 413         }
 414         strbuf_release(&buf);
 415         return 0;
 416 }
 417
 418 static int get_importer(struct transport *transport, struct child_process *fastimport)
 419 {
 420         struct child_process *helper = get_helper(transport);
 421         struct helper_data *data = transport->data;
 422         int cat_blob_fd, code;
 423         child_process_init(fastimport);
 424         fastimport->in = helper->out;
 425         argv_array_push(&fastimport->args, "fast-import");
 426         argv_array_push(&fastimport->args, debug ? "--stats" : "--quiet");
 427
 428         if (data->bidi_import) {
 429                 cat_blob_fd = xdup(helper->in);
 430                 argv_array_pushf(&fastimport->args, "--cat-blob-fd=%d", cat_blob_fd);
 431         }
 432         fastimport->git_cmd = 1;
 433
 434         code = start_command(fastimport);
 435         return code;
 436 }
 437
 438 static int get_exporter(struct transport *transport,
 439                         struct child_process *fastexport,
 440                         struct string_list *revlist_args)
 441 {
 442         struct helper_data *data = transport->data;
 443         struct child_process *helper = get_helper(transport);
 444         int i;
 445
 446         child_process_init(fastexport);
 447
 448         /* we need to duplicate helper->in because we want to use it after
 449          * fastexport is done with it. */
 450         fastexport->out = dup(helper->in);
 451         argv_array_push(&fastexport->args, "fast-export");
 452         argv_array_push(&fastexport->args, "--use-done-feature");
 453         argv_array_push(&fastexport->args, data->signed_tags ?
 454                 "--signed-tags=verbatim" : "--signed-tags=warn-strip");
 455         if (data->export_marks)
 456                 argv_array_pushf(&fastexport->args, "--export-marks=%s.tmp", data->export_marks);
 457         if (data->import_marks)
 458                 argv_array_pushf(&fastexport->args, "--import-marks=%s", data->import_marks);
 459
 460         for (i = 0; i < revlist_args->nr; i++)
 461                 argv_array_push(&fastexport->args, revlist_args->items[i].string);
 462
 463         fastexport->git_cmd = 1;
 464         return start_command(fastexport);
 465 }
 466
 467 static int fetch_with_import(struct transport *transport,
 468                              int nr_heads, struct ref **to_fetch)
 469 {
 470         struct child_process fastimport;
 471         struct helper_data *data = transport->data;
 472         int i;
 473         struct ref *posn;
 474         struct strbuf buf = STRBUF_INIT;
 475
 476         get_helper(transport);
 477
 478         if (get_importer(transport, &fastimport))
 479                 die(_("couldn't run fast-import"));
 480
 481         for (i = 0; i < nr_heads; i++) {
 482                 posn = to_fetch[i];
 483                 if (posn->status & REF_STATUS_UPTODATE)
 484                         continue;
 485
 486                 strbuf_addf(&buf, "import %s\n",
 487                             posn->symref ? posn->symref : posn->name);
 488                 sendline(data, &buf);
 489                 strbuf_reset(&buf);
 490         }
 491
 492         write_constant(data->helper->in, "\n");
 493         /*
 494          * remote-helpers that advertise the bidi-import capability are required to
 495          * buffer the complete batch of import commands until this newline before
 496          * sending data to fast-import.
 497          * These helpers read back data from fast-import on their stdin, which could
 498          * be mixed with import commands, otherwise.
 499          */
 500
 501         if (finish_command(&fastimport))
 502                 die(_("error while running fast-import"));
 503
 504         /*
 505          * The fast-import stream of a remote helper that advertises
 506          * the "refspec" capability writes to the refs named after the
 507          * right hand side of the first refspec matching each ref we
 508          * were fetching.
 509          *
 510          * (If no "refspec" capability was specified, for historical
 511          * reasons we default to the equivalent of *:*.)
 512          *
 513          * Store the result in to_fetch[i].old_sha1.  Callers such
 514          * as "git fetch" can use the value to write feedback to the
 515          * terminal, populate FETCH_HEAD, and determine what new value
 516          * should be written to peer_ref if the update is a
 517          * fast-forward or this is a forced update.
 518          */
 519         for (i = 0; i < nr_heads; i++) {
 520                 char *private, *name;
 521                 posn = to_fetch[i];
 522                 if (posn->status & REF_STATUS_UPTODATE)
 523                         continue;
 524                 name = posn->symref ? posn->symref : posn->name;
 525                 if (data->rs.nr)
 526                         private = apply_refspecs(&data->rs, name);
 527                 else
 528                         private = xstrdup(name);
 529                 if (private) {
 530                         if (read_ref(private, &posn->old_oid) < 0)
 531                                 die(_("could not read ref %s"), private);
 532                         free(private);
 533                 }
 534         }
 535         strbuf_release(&buf);
 536         return 0;
 537 }
 538
 539 static int run_connect(struct transport *transport, struct strbuf *cmdbuf)
 540 {
 541         struct helper_data *data = transport->data;
 542         int ret = 0;
 543         int duped;
 544         FILE *input;
 545         struct child_process *helper;
 546
 547         helper = get_helper(transport);
 548
 549         /*
 550          * Yes, dup the pipe another time, as we need unbuffered version
 551          * of input pipe as FILE*. fclose() closes the underlying fd and
 552          * stream buffering only can be changed before first I/O operation
 553          * on it.
 554          */
 555         duped = dup(helper->out);
 556         if (duped < 0)
 557                 die_errno(_("can't dup helper output fd"));
 558         input = xfdopen(duped, "r");
 559         setvbuf(input, NULL, _IONBF, 0);
 560
 561         sendline(data, cmdbuf);
 562         if (recvline_fh(input, cmdbuf))
 563                 exit(128);
 564
 565         if (!strcmp(cmdbuf->buf, "")) {
 566                 data->no_disconnect_req = 1;
 567                 if (debug)
 568                         fprintf(stderr, "Debug: Smart transport connection "
 569                                 "ready.\n");
 570                 ret = 1;
 571         } else if (!strcmp(cmdbuf->buf, "fallback")) {
 572                 if (debug)
 573                         fprintf(stderr, "Debug: Falling back to dumb "
 574                                 "transport.\n");
 575         } else {
 576                 die(_("unknown response to connect: %s"),
 577                     cmdbuf->buf);
 578         }
 579
 580         fclose(input);
 581         return ret;
 582 }
 583
 584 static int process_connect_service(struct transport *transport,
 585                                    const char *name, const char *exec)
 586 {
 587         struct helper_data *data = transport->data;
 588         struct strbuf cmdbuf = STRBUF_INIT;
 589         int ret = 0;
 590
 591         /*
 592          * Handle --upload-pack and friends. This is fire and forget...
 593          * just warn if it fails.
 594          */
 595         if (strcmp(name, exec)) {
 596                 int r = set_helper_option(transport, "servpath", exec);
 597                 if (r > 0)
 598                         warning(_("setting remote service path not supported by protocol"));
 599                 else if (r < 0)
 600                         warning(_("invalid remote service path"));
 601         }
 602
 603         if (data->connect) {
 604                 strbuf_addf(&cmdbuf, "connect %s\n", name);
 605                 ret = run_connect(transport, &cmdbuf);
 606         } else if (data->stateless_connect &&
 607                    (get_protocol_version_config() == protocol_v2) &&
 608                    !strcmp("git-upload-pack", name)) {
 609                 strbuf_addf(&cmdbuf, "stateless-connect %s\n", name);
 610                 ret = run_connect(transport, &cmdbuf);
 611                 if (ret)
 612                         transport->stateless_rpc = 1;
 613         }
 614
 615         strbuf_release(&cmdbuf);
 616         return ret;
 617 }
 618
 619 static int process_connect(struct transport *transport,
 620                                      int for_push)
 621 {
 622         struct helper_data *data = transport->data;
 623         const char *name;
 624         const char *exec;
 625
 626         name = for_push ? "git-receive-pack" : "git-upload-pack";
 627         if (for_push)
 628                 exec = data->transport_options.receivepack;
 629         else
 630                 exec = data->transport_options.uploadpack;
 631
 632         return process_connect_service(transport, name, exec);
 633 }
 634
 635 static int connect_helper(struct transport *transport, const char *name,
 636                    const char *exec, int fd[2])
 637 {
 638         struct helper_data *data = transport->data;
 639
 640         /* Get_helper so connect is inited. */
 641         get_helper(transport);
 642         if (!data->connect)
 643                 die(_("operation not supported by protocol"));
 644
 645         if (!process_connect_service(transport, name, exec))
 646                 die(_("can't connect to subservice %s"), name);
 647
 648         fd[0] = data->helper->out;
 649         fd[1] = data->helper->in;
 650         return 0;
 651 }
 652
 653 static int fetch(struct transport *transport,
 654                  int nr_heads, struct ref **to_fetch)
 655 {
 656         struct helper_data *data = transport->data;
 657         int i, count;
 658
 659         if (process_connect(transport, 0)) {
 660                 do_take_over(transport);
 661                 return transport->vtable->fetch(transport, nr_heads, to_fetch);
 662         }
 663
 664         count = 0;
 665         for (i = 0; i < nr_heads; i++)
 666                 if (!(to_fetch[i]->status & REF_STATUS_UPTODATE))
 667                         count++;
 668
 669         if (!count)
 670                 return 0;
 671
 672         if (data->check_connectivity &&
 673             data->transport_options.check_self_contained_and_connected)
 674                 set_helper_option(transport, "check-connectivity", "true");
 675
 676         if (transport->cloning)
 677                 set_helper_option(transport, "cloning", "true");
 678
 679         if (data->transport_options.update_shallow)
 680                 set_helper_option(transport, "update-shallow", "true");
 681
 682         if (data->transport_options.filter_options.choice) {
 683                 struct strbuf expanded_filter_spec = STRBUF_INIT;
 684                 expand_list_objects_filter_spec(
 685                         &data->transport_options.filter_options,
 686                         &expanded_filter_spec);
 687                 set_helper_option(transport, "filter",
 688                                   expanded_filter_spec.buf);
 689                 strbuf_release(&expanded_filter_spec);
 690         }
 691
 692         if (data->transport_options.negotiation_tips)
 693                 warning("Ignoring --negotiation-tip because the protocol does not support it.");
 694
 695         if (data->fetch)
 696                 return fetch_with_fetch(transport, nr_heads, to_fetch);
 697
 698         if (data->import)
 699                 return fetch_with_import(transport, nr_heads, to_fetch);
 700
 701         return -1;
 702 }
 703
 704 static int push_update_ref_status(struct strbuf *buf,
 705                                    struct ref **ref,
 706                                    struct ref *remote_refs)
 707 {
 708         char *refname, *msg;
 709         int status, forced = 0;
 710
 711         if (starts_with(buf->buf, "ok ")) {
 712                 status = REF_STATUS_OK;
 713                 refname = buf->buf + 3;
 714         } else if (starts_with(buf->buf, "error ")) {
 715                 status = REF_STATUS_REMOTE_REJECT;
 716                 refname = buf->buf + 6;
 717         } else
 718                 die(_("expected ok/error, helper said '%s'"), buf->buf);
 719
 720         msg = strchr(refname, ' ');
 721         if (msg) {
 722                 struct strbuf msg_buf = STRBUF_INIT;
 723                 const char *end;
 724
 725                 *msg++ = '\0';
 726                 if (!unquote_c_style(&msg_buf, msg, &end))
 727                         msg = strbuf_detach(&msg_buf, NULL);
 728                 else
 729                         msg = xstrdup(msg);
 730                 strbuf_release(&msg_buf);
 731
 732                 if (!strcmp(msg, "no match")) {
 733                         status = REF_STATUS_NONE;
 734                         FREE_AND_NULL(msg);
 735                 }
 736                 else if (!strcmp(msg, "up to date")) {
 737                         status = REF_STATUS_UPTODATE;
 738                         FREE_AND_NULL(msg);
 739                 }
 740                 else if (!strcmp(msg, "non-fast forward")) {
 741                         status = REF_STATUS_REJECT_NONFASTFORWARD;
 742                         FREE_AND_NULL(msg);
 743                 }
 744                 else if (!strcmp(msg, "already exists")) {
 745                         status = REF_STATUS_REJECT_ALREADY_EXISTS;
 746                         FREE_AND_NULL(msg);
 747                 }
 748                 else if (!strcmp(msg, "fetch first")) {
 749                         status = REF_STATUS_REJECT_FETCH_FIRST;
 750                         FREE_AND_NULL(msg);
 751                 }
 752                 else if (!strcmp(msg, "needs force")) {
 753                         status = REF_STATUS_REJECT_NEEDS_FORCE;
 754                         FREE_AND_NULL(msg);
 755                 }
 756                 else if (!strcmp(msg, "stale info")) {
 757                         status = REF_STATUS_REJECT_STALE;
 758                         FREE_AND_NULL(msg);
 759                 }
 760                 else if (!strcmp(msg, "forced update")) {
 761                         forced = 1;
 762                         FREE_AND_NULL(msg);
 763                 }
 764         }
 765
 766         if (*ref)
 767                 *ref = find_ref_by_name(*ref, refname);
 768         if (!*ref)
 769                 *ref = find_ref_by_name(remote_refs, refname);
 770         if (!*ref) {
 771                 warning(_("helper reported unexpected status of %s"), refname);
 772                 return 1;
 773         }
 774
 775         if ((*ref)->status != REF_STATUS_NONE) {
 776                 /*
 777                  * Earlier, the ref was marked not to be pushed, so ignore the ref
 778                  * status reported by the remote helper if the latter is 'no match'.
 779                  */
 780                 if (status == REF_STATUS_NONE)
 781                         return 1;
 782         }
 783
 784         (*ref)->status = status;
 785         (*ref)->forced_update |= forced;
 786         (*ref)->remote_status = msg;
 787         return !(status == REF_STATUS_OK);
 788 }
 789
 790 static int push_update_refs_status(struct helper_data *data,
 791                                     struct ref *remote_refs,
 792                                     int flags)
 793 {
 794         struct strbuf buf = STRBUF_INIT;
 795         struct ref *ref = remote_refs;
 796         int ret = 0;
 797
 798         for (;;) {
 799                 char *private;
 800
 801                 if (recvline(data, &buf)) {
 802                         ret = 1;
 803                         break;
 804                 }
 805
 806                 if (!buf.len)
 807                         break;
 808
 809                 if (push_update_ref_status(&buf, &ref, remote_refs))
 810                         continue;
 811
 812                 if (flags & TRANSPORT_PUSH_DRY_RUN || !data->rs.nr || data->no_private_update)
 813                         continue;
 814
 815                 /* propagate back the update to the remote namespace */
 816                 private = apply_refspecs(&data->rs, ref->name);
 817                 if (!private)
 818                         continue;
 819                 update_ref("update by helper", private, &ref->new_oid, NULL,
 820                            0, 0);
 821                 free(private);
 822         }
 823         strbuf_release(&buf);
 824         return ret;
 825 }
 826
 827 static void set_common_push_options(struct transport *transport,
 828                                    const char *name, int flags)
 829 {
 830         if (flags & TRANSPORT_PUSH_DRY_RUN) {
 831                 if (set_helper_option(transport, "dry-run", "true") != 0)
 832                         die(_("helper %s does not support dry-run"), name);
 833         } else if (flags & TRANSPORT_PUSH_CERT_ALWAYS) {
 834                 if (set_helper_option(transport, TRANS_OPT_PUSH_CERT, "true") != 0)
 835                         die(_("helper %s does not support --signed"), name);
 836         } else if (flags & TRANSPORT_PUSH_CERT_IF_ASKED) {
 837                 if (set_helper_option(transport, TRANS_OPT_PUSH_CERT, "if-asked") != 0)
 838                         die(_("helper %s does not support --signed=if-asked"), name);
 839         }
 840
 841         if (flags & TRANSPORT_PUSH_OPTIONS) {
 842                 struct string_list_item *item;
 843                 for_each_string_list_item(item, transport->push_options)
 844                         if (set_helper_option(transport, "push-option", item->string) != 0)
 845                                 die(_("helper %s does not support 'push-option'"), name);
 846         }
 847 }
 848
 849 static int push_refs_with_push(struct transport *transport,
 850                                struct ref *remote_refs, int flags)
 851 {
 852         int force_all = flags & TRANSPORT_PUSH_FORCE;
 853         int mirror = flags & TRANSPORT_PUSH_MIRROR;
 854         struct helper_data *data = transport->data;
 855         struct strbuf buf = STRBUF_INIT;
 856         struct ref *ref;
 857         struct string_list cas_options = STRING_LIST_INIT_DUP;
 858         struct string_list_item *cas_option;
 859
 860         get_helper(transport);
 861         if (!data->push)
 862                 return 1;
 863
 864         for (ref = remote_refs; ref; ref = ref->next) {
 865                 if (!ref->peer_ref && !mirror)
 866                         continue;
 867
 868                 /* Check for statuses set by set_ref_status_for_push() */
 869                 switch (ref->status) {
 870                 case REF_STATUS_REJECT_NONFASTFORWARD:
 871                 case REF_STATUS_REJECT_STALE:
 872                 case REF_STATUS_REJECT_ALREADY_EXISTS:
 873                 case REF_STATUS_UPTODATE:
 874                         continue;
 875                 default:
 876                         ; /* do nothing */
 877                 }
 878
 879                 if (force_all)
 880                         ref->force = 1;
 881
 882                 strbuf_addstr(&buf, "push ");
 883                 if (!ref->deletion) {
 884                         if (ref->force)
 885                                 strbuf_addch(&buf, '+');
 886                         if (ref->peer_ref)
 887                                 strbuf_addstr(&buf, ref->peer_ref->name);
 888                         else
 889                                 strbuf_addstr(&buf, oid_to_hex(&ref->new_oid));
 890                 }
 891                 strbuf_addch(&buf, ':');
 892                 strbuf_addstr(&buf, ref->name);
 893                 strbuf_addch(&buf, '\n');
 894
 895                 /*
 896                  * The "--force-with-lease" options without explicit
 897                  * values to expect have already been expanded into
 898                  * the ref->old_oid_expect[] field; we can ignore
 899                  * transport->smart_options->cas altogether and instead
 900                  * can enumerate them from the refs.
 901                  */
 902                 if (ref->expect_old_sha1) {
 903                         struct strbuf cas = STRBUF_INIT;
 904                         strbuf_addf(&cas, "%s:%s",
 905                                     ref->name, oid_to_hex(&ref->old_oid_expect));
 906                         string_list_append_nodup(&cas_options,
 907                                                  strbuf_detach(&cas, NULL));
 908                 }
 909         }
 910         if (buf.len == 0) {
 911                 string_list_clear(&cas_options, 0);
 912                 return 0;
 913         }
 914
 915         for_each_string_list_item(cas_option, &cas_options)
 916                 set_helper_option(transport, "cas", cas_option->string);
 917         set_common_push_options(transport, data->name, flags);
 918
 919         strbuf_addch(&buf, '\n');
 920         sendline(data, &buf);
 921         strbuf_release(&buf);
 922         string_list_clear(&cas_options, 0);
 923
 924         return push_update_refs_status(data, remote_refs, flags);
 925 }
 926
 927 static int push_refs_with_export(struct transport *transport,
 928                 struct ref *remote_refs, int flags)
 929 {
 930         struct ref *ref;
 931         struct child_process *helper, exporter;
 932         struct helper_data *data = transport->data;
 933         struct string_list revlist_args = STRING_LIST_INIT_DUP;
 934         struct strbuf buf = STRBUF_INIT;
 935
 936         if (!data->rs.nr)
 937                 die(_("remote-helper doesn't support push; refspec needed"));
 938
 939         set_common_push_options(transport, data->name, flags);
 940         if (flags & TRANSPORT_PUSH_FORCE) {
 941                 if (set_helper_option(transport, "force", "true") != 0)
 942                         warning(_("helper %s does not support 'force'"), data->name);
 943         }
 944
 945         helper = get_helper(transport);
 946
 947         write_constant(helper->in, "export\n");
 948
 949         for (ref = remote_refs; ref; ref = ref->next) {
 950                 char *private;
 951                 struct object_id oid;
 952
 953                 private = apply_refspecs(&data->rs, ref->name);
 954                 if (private && !get_oid(private, &oid)) {
 955                         strbuf_addf(&buf, "^%s", private);
 956                         string_list_append_nodup(&revlist_args,
 957                                                  strbuf_detach(&buf, NULL));
 958                         oidcpy(&ref->old_oid, &oid);
 959                 }
 960                 free(private);
 961
 962                 if (ref->peer_ref) {
 963                         if (strcmp(ref->name, ref->peer_ref->name)) {
 964                                 if (!ref->deletion) {
 965                                         const char *name;
 966                                         int flag;
 967
 968                                         /* Follow symbolic refs (mainly for HEAD). */
 969                                         name = resolve_ref_unsafe(ref->peer_ref->name,
 970                                                                   RESOLVE_REF_READING,
 971                                                                   &oid, &flag);
 972                                         if (!name || !(flag & REF_ISSYMREF))
 973                                                 name = ref->peer_ref->name;
 974
 975                                         strbuf_addf(&buf, "%s:%s", name, ref->name);
 976                                 } else
 977                                         strbuf_addf(&buf, ":%s", ref->name);
 978
 979                                 string_list_append(&revlist_args, "--refspec");
 980                                 string_list_append(&revlist_args, buf.buf);
 981                                 strbuf_release(&buf);
 982                         }
 983                         if (!ref->deletion)
 984                                 string_list_append(&revlist_args, ref->peer_ref->name);
 985                 }
 986         }
 987
 988         if (get_exporter(transport, &exporter, &revlist_args))
 989                 die(_("couldn't run fast-export"));
 990
 991         string_list_clear(&revlist_args, 1);
 992
 993         if (finish_command(&exporter))
 994                 die(_("error while running fast-export"));
 995         if (push_update_refs_status(data, remote_refs, flags))
 996                 return 1;
 997
 998         if (data->export_marks) {
 999                 strbuf_addf(&buf, "%s.tmp", data->export_marks);
1000                 rename(buf.buf, data->export_marks);
1001                 strbuf_release(&buf);
1002         }
1003
1004         return 0;
1005 }
1006
1007 static int push_refs(struct transport *transport,
1008                 struct ref *remote_refs, int flags)
1009 {
1010         struct helper_data *data = transport->data;
1011
1012         if (process_connect(transport, 1)) {
1013                 do_take_over(transport);
1014                 return transport->vtable->push_refs(transport, remote_refs, flags);
1015         }
1016
1017         if (!remote_refs) {
1018                 fprintf(stderr,
1019                         _("No refs in common and none specified; doing nothing.\n"
1020                           "Perhaps you should specify a branch such as 'master'.\n"));
1021                 return 0;
1022         }
1023
1024         if (data->push)
1025                 return push_refs_with_push(transport, remote_refs, flags);
1026
1027         if (data->export)
1028                 return push_refs_with_export(transport, remote_refs, flags);
1029
1030         return -1;
1031 }
1032
1033
1034 static int has_attribute(const char *attrs, const char *attr)
1035 {
1036         int len;
1037         if (!attrs)
1038                 return 0;
1039
1040         len = strlen(attr);
1041         for (;;) {
1042                 const char *space = strchrnul(attrs, ' ');
1043                 if (len == space - attrs && !strncmp(attrs, attr, len))
1044                         return 1;
1045                 if (!*space)
1046                         return 0;
1047                 attrs = space + 1;
1048         }
1049 }
1050
1051 static struct ref *get_refs_list(struct transport *transport, int for_push,
1052                                  const struct argv_array *ref_prefixes)
1053 {
1054         struct helper_data *data = transport->data;
1055         struct child_process *helper;
1056         struct ref *ret = NULL;
1057         struct ref **tail = &ret;
1058         struct ref *posn;
1059         struct strbuf buf = STRBUF_INIT;
1060
1061         helper = get_helper(transport);
1062
1063         if (process_connect(transport, for_push)) {
1064                 do_take_over(transport);
1065                 return transport->vtable->get_refs_list(transport, for_push, ref_prefixes);
1066         }
1067
1068         if (data->push && for_push)
1069                 write_str_in_full(helper->in, "list for-push\n");
1070         else
1071                 write_str_in_full(helper->in, "list\n");
1072
1073         while (1) {
1074                 char *eov, *eon;
1075                 if (recvline(data, &buf))
1076                         exit(128);
1077
1078                 if (!*buf.buf)
1079                         break;
1080
1081                 eov = strchr(buf.buf, ' ');
1082                 if (!eov)
1083                         die(_("malformed response in ref list: %s"), buf.buf);
1084                 eon = strchr(eov + 1, ' ');
1085                 *eov = '\0';
1086                 if (eon)
1087                         *eon = '\0';
1088                 *tail = alloc_ref(eov + 1);
1089                 if (buf.buf[0] == '@')
1090                         (*tail)->symref = xstrdup(buf.buf + 1);
1091                 else if (buf.buf[0] != '?')
1092                         get_oid_hex(buf.buf, &(*tail)->old_oid);
1093                 if (eon) {
1094                         if (has_attribute(eon + 1, "unchanged")) {
1095                                 (*tail)->status |= REF_STATUS_UPTODATE;
1096                                 if (read_ref((*tail)->name, &(*tail)->old_oid) < 0)
1097                                         die(_("could not read ref %s"),
1098                                             (*tail)->name);
1099                         }
1100                 }
1101                 tail = &((*tail)->next);
1102         }
1103         if (debug)
1104                 fprintf(stderr, "Debug: Read ref listing.\n");
1105         strbuf_release(&buf);
1106
1107         for (posn = ret; posn; posn = posn->next)
1108                 resolve_remote_symref(posn, ret);
1109
1110         return ret;
1111 }
1112
1113 static struct transport_vtable vtable = {
1114         0,
1115         set_helper_option,
1116         get_refs_list,
1117         fetch,
1118         push_refs,
1119         connect_helper,
1120         release_helper
1121 };
1122
1123 int transport_helper_init(struct transport *transport, const char *name)
1124 {
1125         struct helper_data *data = xcalloc(1, sizeof(*data));
1126         data->name = name;
1127
1128         transport_check_allowed(name);
1129
1130         if (getenv("GIT_TRANSPORT_HELPER_DEBUG"))
1131                 debug = 1;
1132
1133         transport->data = data;
1134         transport->vtable = &vtable;
1135         transport->smart_options = &(data->transport_options);
1136         return 0;
1137 }
1138
1139 /*
1140  * Linux pipes can buffer 65536 bytes at once (and most platforms can
1141  * buffer less), so attempt reads and writes with up to that size.
1142  */
1143 #define BUFFERSIZE 65536
1144 /* This should be enough to hold debugging message. */
1145 #define PBUFFERSIZE 8192
1146
1147 /* Print bidirectional transfer loop debug message. */
1148 __attribute__((format (printf, 1, 2)))
1149 static void transfer_debug(const char *fmt, ...)
1150 {
1151         /*
1152          * NEEDSWORK: This function is sometimes used from multiple threads, and
1153          * we end up using debug_enabled racily. That "should not matter" since
1154          * we always write the same value, but it's still wrong. This function
1155          * is listed in .tsan-suppressions for the time being.
1156          */
1157
1158         va_list args;
1159         char msgbuf[PBUFFERSIZE];
1160         static int debug_enabled = -1;
1161
1162         if (debug_enabled < 0)
1163                 debug_enabled = getenv("GIT_TRANSLOOP_DEBUG") ? 1 : 0;
1164         if (!debug_enabled)
1165                 return;
1166
1167         va_start(args, fmt);
1168         vsnprintf(msgbuf, PBUFFERSIZE, fmt, args);
1169         va_end(args);
1170         fprintf(stderr, "Transfer loop debugging: %s\n", msgbuf);
1171 }
1172
1173 /* Stream state: More data may be coming in this direction. */
1174 #define SSTATE_TRANSFERRING 0
1175 /*
1176  * Stream state: No more data coming in this direction, flushing rest of
1177  * data.
1178  */
1179 #define SSTATE_FLUSHING 1
1180 /* Stream state: Transfer in this direction finished. */
1181 #define SSTATE_FINISHED 2
1182
1183 #define STATE_NEEDS_READING(state) ((state) <= SSTATE_TRANSFERRING)
1184 #define STATE_NEEDS_WRITING(state) ((state) <= SSTATE_FLUSHING)
1185 #define STATE_NEEDS_CLOSING(state) ((state) == SSTATE_FLUSHING)
1186
1187 /* Unidirectional transfer. */
1188 struct unidirectional_transfer {
1189         /* Source */
1190         int src;
1191         /* Destination */
1192         int dest;
1193         /* Is source socket? */
1194         int src_is_sock;
1195         /* Is destination socket? */
1196         int dest_is_sock;
1197         /* Transfer state (TRANSFERRING/FLUSHING/FINISHED) */
1198         int state;
1199         /* Buffer. */
1200         char buf[BUFFERSIZE];
1201         /* Buffer used. */
1202         size_t bufuse;
1203         /* Name of source. */
1204         const char *src_name;
1205         /* Name of destination. */
1206         const char *dest_name;
1207 };
1208
1209 /* Closes the target (for writing) if transfer has finished. */
1210 static void udt_close_if_finished(struct unidirectional_transfer *t)
1211 {
1212         if (STATE_NEEDS_CLOSING(t->state) && !t->bufuse) {
1213                 t->state = SSTATE_FINISHED;
1214                 if (t->dest_is_sock)
1215                         shutdown(t->dest, SHUT_WR);
1216                 else
1217                         close(t->dest);
1218                 transfer_debug("Closed %s.", t->dest_name);
1219         }
1220 }
1221
1222 /*
1223  * Tries to read data from source into buffer. If buffer is full,
1224  * no data is read. Returns 0 on success, -1 on error.
1225  */
1226 static int udt_do_read(struct unidirectional_transfer *t)
1227 {
1228         ssize_t bytes;
1229
1230         if (t->bufuse == BUFFERSIZE)
1231                 return 0;       /* No space for more. */
1232
1233         transfer_debug("%s is readable", t->src_name);
1234         bytes = xread(t->src, t->buf + t->bufuse, BUFFERSIZE - t->bufuse);
1235         if (bytes < 0) {
1236                 error_errno(_("read(%s) failed"), t->src_name);
1237                 return -1;
1238         } else if (bytes == 0) {
1239                 transfer_debug("%s EOF (with %i bytes in buffer)",
1240                         t->src_name, (int)t->bufuse);
1241                 t->state = SSTATE_FLUSHING;
1242         } else if (bytes > 0) {
1243                 t->bufuse += bytes;
1244                 transfer_debug("Read %i bytes from %s (buffer now at %i)",
1245                         (int)bytes, t->src_name, (int)t->bufuse);
1246         }
1247         return 0;
1248 }
1249
1250 /* Tries to write data from buffer into destination. If buffer is empty,
1251  * no data is written. Returns 0 on success, -1 on error.
1252  */
1253 static int udt_do_write(struct unidirectional_transfer *t)
1254 {
1255         ssize_t bytes;
1256
1257         if (t->bufuse == 0)
1258                 return 0;       /* Nothing to write. */
1259
1260         transfer_debug("%s is writable", t->dest_name);
1261         bytes = xwrite(t->dest, t->buf, t->bufuse);
1262         if (bytes < 0) {
1263                 error_errno(_("write(%s) failed"), t->dest_name);
1264                 return -1;
1265         } else if (bytes > 0) {
1266                 t->bufuse -= bytes;
1267                 if (t->bufuse)
1268                         memmove(t->buf, t->buf + bytes, t->bufuse);
1269                 transfer_debug("Wrote %i bytes to %s (buffer now at %i)",
1270                         (int)bytes, t->dest_name, (int)t->bufuse);
1271         }
1272         return 0;
1273 }
1274
1275
1276 /* State of bidirectional transfer loop. */
1277 struct bidirectional_transfer_state {
1278         /* Direction from program to git. */
1279         struct unidirectional_transfer ptg;
1280         /* Direction from git to program. */
1281         struct unidirectional_transfer gtp;
1282 };
1283
1284 static void *udt_copy_task_routine(void *udt)
1285 {
1286         struct unidirectional_transfer *t = (struct unidirectional_transfer *)udt;
1287         while (t->state != SSTATE_FINISHED) {
1288                 if (STATE_NEEDS_READING(t->state))
1289                         if (udt_do_read(t))
1290                                 return NULL;
1291                 if (STATE_NEEDS_WRITING(t->state))
1292                         if (udt_do_write(t))
1293                                 return NULL;
1294                 if (STATE_NEEDS_CLOSING(t->state))
1295                         udt_close_if_finished(t);
1296         }
1297         return udt;     /* Just some non-NULL value. */
1298 }
1299
1300 #ifndef NO_PTHREADS
1301
1302 /*
1303  * Join thread, with appropriate errors on failure. Name is name for the
1304  * thread (for error messages). Returns 0 on success, 1 on failure.
1305  */
1306 static int tloop_join(pthread_t thread, const char *name)
1307 {
1308         int err;
1309         void *tret;
1310         err = pthread_join(thread, &tret);
1311         if (!tret) {
1312                 error(_("%s thread failed"), name);
1313                 return 1;
1314         }
1315         if (err) {
1316                 error(_("%s thread failed to join: %s"), name, strerror(err));
1317                 return 1;
1318         }
1319         return 0;
1320 }
1321
1322 /*
1323  * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1324  * -1 on failure.
1325  */
1326 static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1327 {
1328         pthread_t gtp_thread;
1329         pthread_t ptg_thread;
1330         int err;
1331         int ret = 0;
1332         err = pthread_create(&gtp_thread, NULL, udt_copy_task_routine,
1333                 &s->gtp);
1334         if (err)
1335                 die(_("can't start thread for copying data: %s"), strerror(err));
1336         err = pthread_create(&ptg_thread, NULL, udt_copy_task_routine,
1337                 &s->ptg);
1338         if (err)
1339                 die(_("can't start thread for copying data: %s"), strerror(err));
1340
1341         ret |= tloop_join(gtp_thread, "Git to program copy");
1342         ret |= tloop_join(ptg_thread, "Program to git copy");
1343         return ret;
1344 }
1345 #else
1346
1347 /* Close the source and target (for writing) for transfer. */
1348 static void udt_kill_transfer(struct unidirectional_transfer *t)
1349 {
1350         t->state = SSTATE_FINISHED;
1351         /*
1352          * Socket read end left open isn't a disaster if nobody
1353          * attempts to read from it (mingw compat headers do not
1354          * have SHUT_RD)...
1355          *
1356          * We can't fully close the socket since otherwise gtp
1357          * task would first close the socket it sends data to
1358          * while closing the ptg file descriptors.
1359          */
1360         if (!t->src_is_sock)
1361                 close(t->src);
1362         if (t->dest_is_sock)
1363                 shutdown(t->dest, SHUT_WR);
1364         else
1365                 close(t->dest);
1366 }
1367
1368 /*
1369  * Join process, with appropriate errors on failure. Name is name for the
1370  * process (for error messages). Returns 0 on success, 1 on failure.
1371  */
1372 static int tloop_join(pid_t pid, const char *name)
1373 {
1374         int tret;
1375         if (waitpid(pid, &tret, 0) < 0) {
1376                 error_errno(_("%s process failed to wait"), name);
1377                 return 1;
1378         }
1379         if (!WIFEXITED(tret) || WEXITSTATUS(tret)) {
1380                 error(_("%s process failed"), name);
1381                 return 1;
1382         }
1383         return 0;
1384 }
1385
1386 /*
1387  * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1388  * -1 on failure.
1389  */
1390 static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1391 {
1392         pid_t pid1, pid2;
1393         int ret = 0;
1394
1395         /* Fork thread #1: git to program. */
1396         pid1 = fork();
1397         if (pid1 < 0)
1398                 die_errno(_("can't start thread for copying data"));
1399         else if (pid1 == 0) {
1400                 udt_kill_transfer(&s->ptg);
1401                 exit(udt_copy_task_routine(&s->gtp) ? 0 : 1);
1402         }
1403
1404         /* Fork thread #2: program to git. */
1405         pid2 = fork();
1406         if (pid2 < 0)
1407                 die_errno(_("can't start thread for copying data"));
1408         else if (pid2 == 0) {
1409                 udt_kill_transfer(&s->gtp);
1410                 exit(udt_copy_task_routine(&s->ptg) ? 0 : 1);
1411         }
1412
1413         /*
1414          * Close both streams in parent as to not interfere with
1415          * end of file detection and wait for both tasks to finish.
1416          */
1417         udt_kill_transfer(&s->gtp);
1418         udt_kill_transfer(&s->ptg);
1419         ret |= tloop_join(pid1, "Git to program copy");
1420         ret |= tloop_join(pid2, "Program to git copy");
1421         return ret;
1422 }
1423 #endif
1424
1425 /*
1426  * Copies data from stdin to output and from input to stdout simultaneously.
1427  * Additionally filtering through given filter. If filter is NULL, uses
1428  * identity filter.
1429  */
1430 int bidirectional_transfer_loop(int input, int output)
1431 {
1432         struct bidirectional_transfer_state state;
1433
1434         /* Fill the state fields. */
1435         state.ptg.src = input;
1436         state.ptg.dest = 1;
1437         state.ptg.src_is_sock = (input == output);
1438         state.ptg.dest_is_sock = 0;
1439         state.ptg.state = SSTATE_TRANSFERRING;
1440         state.ptg.bufuse = 0;
1441         state.ptg.src_name = "remote input";
1442         state.ptg.dest_name = "stdout";
1443
1444         state.gtp.src = 0;
1445         state.gtp.dest = output;
1446         state.gtp.src_is_sock = 0;
1447         state.gtp.dest_is_sock = (input == output);
1448         state.gtp.state = SSTATE_TRANSFERRING;
1449         state.gtp.bufuse = 0;
1450         state.gtp.src_name = "stdin";
1451         state.gtp.dest_name = "remote output";
1452
1453         return tloop_spawnwait_tasks(&state);
1454 }