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, "--allow-unsafe-features");
 427         argv_array_push(&fastimport->args, debug ? "--stats" : "--quiet");
 428
 429         if (data->bidi_import) {
 430                 cat_blob_fd = xdup(helper->in);
 431                 argv_array_pushf(&fastimport->args, "--cat-blob-fd=%d", cat_blob_fd);
 432         }
 433         fastimport->git_cmd = 1;
 434
 435         code = start_command(fastimport);
 436         return code;
 437 }
 438
 439 static int get_exporter(struct transport *transport,
 440                         struct child_process *fastexport,
 441                         struct string_list *revlist_args)
 442 {
 443         struct helper_data *data = transport->data;
 444         struct child_process *helper = get_helper(transport);
 445         int i;
 446
 447         child_process_init(fastexport);
 448
 449         /* we need to duplicate helper->in because we want to use it after
 450          * fastexport is done with it. */
 451         fastexport->out = dup(helper->in);
 452         argv_array_push(&fastexport->args, "fast-export");
 453         argv_array_push(&fastexport->args, "--use-done-feature");
 454         argv_array_push(&fastexport->args, data->signed_tags ?
 455                 "--signed-tags=verbatim" : "--signed-tags=warn-strip");
 456         if (data->export_marks)
 457                 argv_array_pushf(&fastexport->args, "--export-marks=%s.tmp", data->export_marks);
 458         if (data->import_marks)
 459                 argv_array_pushf(&fastexport->args, "--import-marks=%s", data->import_marks);
 460
 461         for (i = 0; i < revlist_args->nr; i++)
 462                 argv_array_push(&fastexport->args, revlist_args->items[i].string);
 463
 464         fastexport->git_cmd = 1;
 465         return start_command(fastexport);
 466 }
 467
 468 static int fetch_with_import(struct transport *transport,
 469                              int nr_heads, struct ref **to_fetch)
 470 {
 471         struct child_process fastimport;
 472         struct helper_data *data = transport->data;
 473         int i;
 474         struct ref *posn;
 475         struct strbuf buf = STRBUF_INIT;
 476
 477         get_helper(transport);
 478
 479         if (get_importer(transport, &fastimport))
 480                 die(_("couldn't run fast-import"));
 481
 482         for (i = 0; i < nr_heads; i++) {
 483                 posn = to_fetch[i];
 484                 if (posn->status & REF_STATUS_UPTODATE)
 485                         continue;
 486
 487                 strbuf_addf(&buf, "import %s\n",
 488                             posn->symref ? posn->symref : posn->name);
 489                 sendline(data, &buf);
 490                 strbuf_reset(&buf);
 491         }
 492
 493         write_constant(data->helper->in, "\n");
 494         /*
 495          * remote-helpers that advertise the bidi-import capability are required to
 496          * buffer the complete batch of import commands until this newline before
 497          * sending data to fast-import.
 498          * These helpers read back data from fast-import on their stdin, which could
 499          * be mixed with import commands, otherwise.
 500          */
 501
 502         if (finish_command(&fastimport))
 503                 die(_("error while running fast-import"));
 504
 505         /*
 506          * The fast-import stream of a remote helper that advertises
 507          * the "refspec" capability writes to the refs named after the
 508          * right hand side of the first refspec matching each ref we
 509          * were fetching.
 510          *
 511          * (If no "refspec" capability was specified, for historical
 512          * reasons we default to the equivalent of *:*.)
 513          *
 514          * Store the result in to_fetch[i].old_sha1.  Callers such
 515          * as "git fetch" can use the value to write feedback to the
 516          * terminal, populate FETCH_HEAD, and determine what new value
 517          * should be written to peer_ref if the update is a
 518          * fast-forward or this is a forced update.
 519          */
 520         for (i = 0; i < nr_heads; i++) {
 521                 char *private, *name;
 522                 posn = to_fetch[i];
 523                 if (posn->status & REF_STATUS_UPTODATE)
 524                         continue;
 525                 name = posn->symref ? posn->symref : posn->name;
 526                 if (data->rs.nr)
 527                         private = apply_refspecs(&data->rs, name);
 528                 else
 529                         private = xstrdup(name);
 530                 if (private) {
 531                         if (read_ref(private, &posn->old_oid) < 0)
 532                                 die(_("could not read ref %s"), private);
 533                         free(private);
 534                 }
 535         }
 536         strbuf_release(&buf);
 537         return 0;
 538 }
 539
 540 static int run_connect(struct transport *transport, struct strbuf *cmdbuf)
 541 {
 542         struct helper_data *data = transport->data;
 543         int ret = 0;
 544         int duped;
 545         FILE *input;
 546         struct child_process *helper;
 547
 548         helper = get_helper(transport);
 549
 550         /*
 551          * Yes, dup the pipe another time, as we need unbuffered version
 552          * of input pipe as FILE*. fclose() closes the underlying fd and
 553          * stream buffering only can be changed before first I/O operation
 554          * on it.
 555          */
 556         duped = dup(helper->out);
 557         if (duped < 0)
 558                 die_errno(_("can't dup helper output fd"));
 559         input = xfdopen(duped, "r");
 560         setvbuf(input, NULL, _IONBF, 0);
 561
 562         sendline(data, cmdbuf);
 563         if (recvline_fh(input, cmdbuf))
 564                 exit(128);
 565
 566         if (!strcmp(cmdbuf->buf, "")) {
 567                 data->no_disconnect_req = 1;
 568                 if (debug)
 569                         fprintf(stderr, "Debug: Smart transport connection "
 570                                 "ready.\n");
 571                 ret = 1;
 572         } else if (!strcmp(cmdbuf->buf, "fallback")) {
 573                 if (debug)
 574                         fprintf(stderr, "Debug: Falling back to dumb "
 575                                 "transport.\n");
 576         } else {
 577                 die(_("unknown response to connect: %s"),
 578                     cmdbuf->buf);
 579         }
 580
 581         fclose(input);
 582         return ret;
 583 }
 584
 585 static int process_connect_service(struct transport *transport,
 586                                    const char *name, const char *exec)
 587 {
 588         struct helper_data *data = transport->data;
 589         struct strbuf cmdbuf = STRBUF_INIT;
 590         int ret = 0;
 591
 592         /*
 593          * Handle --upload-pack and friends. This is fire and forget...
 594          * just warn if it fails.
 595          */
 596         if (strcmp(name, exec)) {
 597                 int r = set_helper_option(transport, "servpath", exec);
 598                 if (r > 0)
 599                         warning(_("setting remote service path not supported by protocol"));
 600                 else if (r < 0)
 601                         warning(_("invalid remote service path"));
 602         }
 603
 604         if (data->connect) {
 605                 strbuf_addf(&cmdbuf, "connect %s\n", name);
 606                 ret = run_connect(transport, &cmdbuf);
 607         } else if (data->stateless_connect &&
 608                    (get_protocol_version_config() == protocol_v2) &&
 609                    !strcmp("git-upload-pack", name)) {
 610                 strbuf_addf(&cmdbuf, "stateless-connect %s\n", name);
 611                 ret = run_connect(transport, &cmdbuf);
 612                 if (ret)
 613                         transport->stateless_rpc = 1;
 614         }
 615
 616         strbuf_release(&cmdbuf);
 617         return ret;
 618 }
 619
 620 static int process_connect(struct transport *transport,
 621                                      int for_push)
 622 {
 623         struct helper_data *data = transport->data;
 624         const char *name;
 625         const char *exec;
 626
 627         name = for_push ? "git-receive-pack" : "git-upload-pack";
 628         if (for_push)
 629                 exec = data->transport_options.receivepack;
 630         else
 631                 exec = data->transport_options.uploadpack;
 632
 633         return process_connect_service(transport, name, exec);
 634 }
 635
 636 static int connect_helper(struct transport *transport, const char *name,
 637                    const char *exec, int fd[2])
 638 {
 639         struct helper_data *data = transport->data;
 640
 641         /* Get_helper so connect is inited. */
 642         get_helper(transport);
 643         if (!data->connect)
 644                 die(_("operation not supported by protocol"));
 645
 646         if (!process_connect_service(transport, name, exec))
 647                 die(_("can't connect to subservice %s"), name);
 648
 649         fd[0] = data->helper->out;
 650         fd[1] = data->helper->in;
 651         return 0;
 652 }
 653
 654 static int fetch(struct transport *transport,
 655                  int nr_heads, struct ref **to_fetch)
 656 {
 657         struct helper_data *data = transport->data;
 658         int i, count;
 659
 660         if (process_connect(transport, 0)) {
 661                 do_take_over(transport);
 662                 return transport->vtable->fetch(transport, nr_heads, to_fetch);
 663         }
 664
 665         count = 0;
 666         for (i = 0; i < nr_heads; i++)
 667                 if (!(to_fetch[i]->status & REF_STATUS_UPTODATE))
 668                         count++;
 669
 670         if (!count)
 671                 return 0;
 672
 673         if (data->check_connectivity &&
 674             data->transport_options.check_self_contained_and_connected)
 675                 set_helper_option(transport, "check-connectivity", "true");
 676
 677         if (transport->cloning)
 678                 set_helper_option(transport, "cloning", "true");
 679
 680         if (data->transport_options.update_shallow)
 681                 set_helper_option(transport, "update-shallow", "true");
 682
 683         if (data->transport_options.filter_options.choice) {
 684                 struct strbuf expanded_filter_spec = STRBUF_INIT;
 685                 expand_list_objects_filter_spec(
 686                         &data->transport_options.filter_options,
 687                         &expanded_filter_spec);
 688                 set_helper_option(transport, "filter",
 689                                   expanded_filter_spec.buf);
 690                 strbuf_release(&expanded_filter_spec);
 691         }
 692
 693         if (data->transport_options.negotiation_tips)
 694                 warning("Ignoring --negotiation-tip because the protocol does not support it.");
 695
 696         if (data->fetch)
 697                 return fetch_with_fetch(transport, nr_heads, to_fetch);
 698
 699         if (data->import)
 700                 return fetch_with_import(transport, nr_heads, to_fetch);
 701
 702         return -1;
 703 }
 704
 705 static int push_update_ref_status(struct strbuf *buf,
 706                                    struct ref **ref,
 707                                    struct ref *remote_refs)
 708 {
 709         char *refname, *msg;
 710         int status, forced = 0;
 711
 712         if (starts_with(buf->buf, "ok ")) {
 713                 status = REF_STATUS_OK;
 714                 refname = buf->buf + 3;
 715         } else if (starts_with(buf->buf, "error ")) {
 716                 status = REF_STATUS_REMOTE_REJECT;
 717                 refname = buf->buf + 6;
 718         } else
 719                 die(_("expected ok/error, helper said '%s'"), buf->buf);
 720
 721         msg = strchr(refname, ' ');
 722         if (msg) {
 723                 struct strbuf msg_buf = STRBUF_INIT;
 724                 const char *end;
 725
 726                 *msg++ = '\0';
 727                 if (!unquote_c_style(&msg_buf, msg, &end))
 728                         msg = strbuf_detach(&msg_buf, NULL);
 729                 else
 730                         msg = xstrdup(msg);
 731                 strbuf_release(&msg_buf);
 732
 733                 if (!strcmp(msg, "no match")) {
 734                         status = REF_STATUS_NONE;
 735                         FREE_AND_NULL(msg);
 736                 }
 737                 else if (!strcmp(msg, "up to date")) {
 738                         status = REF_STATUS_UPTODATE;
 739                         FREE_AND_NULL(msg);
 740                 }
 741                 else if (!strcmp(msg, "non-fast forward")) {
 742                         status = REF_STATUS_REJECT_NONFASTFORWARD;
 743                         FREE_AND_NULL(msg);
 744                 }
 745                 else if (!strcmp(msg, "already exists")) {
 746                         status = REF_STATUS_REJECT_ALREADY_EXISTS;
 747                         FREE_AND_NULL(msg);
 748                 }
 749                 else if (!strcmp(msg, "fetch first")) {
 750                         status = REF_STATUS_REJECT_FETCH_FIRST;
 751                         FREE_AND_NULL(msg);
 752                 }
 753                 else if (!strcmp(msg, "needs force")) {
 754                         status = REF_STATUS_REJECT_NEEDS_FORCE;
 755                         FREE_AND_NULL(msg);
 756                 }
 757                 else if (!strcmp(msg, "stale info")) {
 758                         status = REF_STATUS_REJECT_STALE;
 759                         FREE_AND_NULL(msg);
 760                 }
 761                 else if (!strcmp(msg, "forced update")) {
 762                         forced = 1;
 763                         FREE_AND_NULL(msg);
 764                 }
 765         }
 766
 767         if (*ref)
 768                 *ref = find_ref_by_name(*ref, refname);
 769         if (!*ref)
 770                 *ref = find_ref_by_name(remote_refs, refname);
 771         if (!*ref) {
 772                 warning(_("helper reported unexpected status of %s"), refname);
 773                 return 1;
 774         }
 775
 776         if ((*ref)->status != REF_STATUS_NONE) {
 777                 /*
 778                  * Earlier, the ref was marked not to be pushed, so ignore the ref
 779                  * status reported by the remote helper if the latter is 'no match'.
 780                  */
 781                 if (status == REF_STATUS_NONE)
 782                         return 1;
 783         }
 784
 785         (*ref)->status = status;
 786         (*ref)->forced_update |= forced;
 787         (*ref)->remote_status = msg;
 788         return !(status == REF_STATUS_OK);
 789 }
 790
 791 static int push_update_refs_status(struct helper_data *data,
 792                                     struct ref *remote_refs,
 793                                     int flags)
 794 {
 795         struct strbuf buf = STRBUF_INIT;
 796         struct ref *ref = remote_refs;
 797         int ret = 0;
 798
 799         for (;;) {
 800                 char *private;
 801
 802                 if (recvline(data, &buf)) {
 803                         ret = 1;
 804                         break;
 805                 }
 806
 807                 if (!buf.len)
 808                         break;
 809
 810                 if (push_update_ref_status(&buf, &ref, remote_refs))
 811                         continue;
 812
 813                 if (flags & TRANSPORT_PUSH_DRY_RUN || !data->rs.nr || data->no_private_update)
 814                         continue;
 815
 816                 /* propagate back the update to the remote namespace */
 817                 private = apply_refspecs(&data->rs, ref->name);
 818                 if (!private)
 819                         continue;
 820                 update_ref("update by helper", private, &ref->new_oid, NULL,
 821                            0, 0);
 822                 free(private);
 823         }
 824         strbuf_release(&buf);
 825         return ret;
 826 }
 827
 828 static void set_common_push_options(struct transport *transport,
 829                                    const char *name, int flags)
 830 {
 831         if (flags & TRANSPORT_PUSH_DRY_RUN) {
 832                 if (set_helper_option(transport, "dry-run", "true") != 0)
 833                         die(_("helper %s does not support dry-run"), name);
 834         } else if (flags & TRANSPORT_PUSH_CERT_ALWAYS) {
 835                 if (set_helper_option(transport, TRANS_OPT_PUSH_CERT, "true") != 0)
 836                         die(_("helper %s does not support --signed"), name);
 837         } else if (flags & TRANSPORT_PUSH_CERT_IF_ASKED) {
 838                 if (set_helper_option(transport, TRANS_OPT_PUSH_CERT, "if-asked") != 0)
 839                         die(_("helper %s does not support --signed=if-asked"), name);
 840         }
 841
 842         if (flags & TRANSPORT_PUSH_OPTIONS) {
 843                 struct string_list_item *item;
 844                 for_each_string_list_item(item, transport->push_options)
 845                         if (set_helper_option(transport, "push-option", item->string) != 0)
 846                                 die(_("helper %s does not support 'push-option'"), name);
 847         }
 848 }
 849
 850 static int push_refs_with_push(struct transport *transport,
 851                                struct ref *remote_refs, int flags)
 852 {
 853         int force_all = flags & TRANSPORT_PUSH_FORCE;
 854         int mirror = flags & TRANSPORT_PUSH_MIRROR;
 855         struct helper_data *data = transport->data;
 856         struct strbuf buf = STRBUF_INIT;
 857         struct ref *ref;
 858         struct string_list cas_options = STRING_LIST_INIT_DUP;
 859         struct string_list_item *cas_option;
 860
 861         get_helper(transport);
 862         if (!data->push)
 863                 return 1;
 864
 865         for (ref = remote_refs; ref; ref = ref->next) {
 866                 if (!ref->peer_ref && !mirror)
 867                         continue;
 868
 869                 /* Check for statuses set by set_ref_status_for_push() */
 870                 switch (ref->status) {
 871                 case REF_STATUS_REJECT_NONFASTFORWARD:
 872                 case REF_STATUS_REJECT_STALE:
 873                 case REF_STATUS_REJECT_ALREADY_EXISTS:
 874                 case REF_STATUS_UPTODATE:
 875                         continue;
 876                 default:
 877                         ; /* do nothing */
 878                 }
 879
 880                 if (force_all)
 881                         ref->force = 1;
 882
 883                 strbuf_addstr(&buf, "push ");
 884                 if (!ref->deletion) {
 885                         if (ref->force)
 886                                 strbuf_addch(&buf, '+');
 887                         if (ref->peer_ref)
 888                                 strbuf_addstr(&buf, ref->peer_ref->name);
 889                         else
 890                                 strbuf_addstr(&buf, oid_to_hex(&ref->new_oid));
 891                 }
 892                 strbuf_addch(&buf, ':');
 893                 strbuf_addstr(&buf, ref->name);
 894                 strbuf_addch(&buf, '\n');
 895
 896                 /*
 897                  * The "--force-with-lease" options without explicit
 898                  * values to expect have already been expanded into
 899                  * the ref->old_oid_expect[] field; we can ignore
 900                  * transport->smart_options->cas altogether and instead
 901                  * can enumerate them from the refs.
 902                  */
 903                 if (ref->expect_old_sha1) {
 904                         struct strbuf cas = STRBUF_INIT;
 905                         strbuf_addf(&cas, "%s:%s",
 906                                     ref->name, oid_to_hex(&ref->old_oid_expect));
 907                         string_list_append_nodup(&cas_options,
 908                                                  strbuf_detach(&cas, NULL));
 909                 }
 910         }
 911         if (buf.len == 0) {
 912                 string_list_clear(&cas_options, 0);
 913                 return 0;
 914         }
 915
 916         for_each_string_list_item(cas_option, &cas_options)
 917                 set_helper_option(transport, "cas", cas_option->string);
 918         set_common_push_options(transport, data->name, flags);
 919
 920         strbuf_addch(&buf, '\n');
 921         sendline(data, &buf);
 922         strbuf_release(&buf);
 923         string_list_clear(&cas_options, 0);
 924
 925         return push_update_refs_status(data, remote_refs, flags);
 926 }
 927
 928 static int push_refs_with_export(struct transport *transport,
 929                 struct ref *remote_refs, int flags)
 930 {
 931         struct ref *ref;
 932         struct child_process *helper, exporter;
 933         struct helper_data *data = transport->data;
 934         struct string_list revlist_args = STRING_LIST_INIT_DUP;
 935         struct strbuf buf = STRBUF_INIT;
 936
 937         if (!data->rs.nr)
 938                 die(_("remote-helper doesn't support push; refspec needed"));
 939
 940         set_common_push_options(transport, data->name, flags);
 941         if (flags & TRANSPORT_PUSH_FORCE) {
 942                 if (set_helper_option(transport, "force", "true") != 0)
 943                         warning(_("helper %s does not support 'force'"), data->name);
 944         }
 945
 946         helper = get_helper(transport);
 947
 948         write_constant(helper->in, "export\n");
 949
 950         for (ref = remote_refs; ref; ref = ref->next) {
 951                 char *private;
 952                 struct object_id oid;
 953
 954                 private = apply_refspecs(&data->rs, ref->name);
 955                 if (private && !get_oid(private, &oid)) {
 956                         strbuf_addf(&buf, "^%s", private);
 957                         string_list_append_nodup(&revlist_args,
 958                                                  strbuf_detach(&buf, NULL));
 959                         oidcpy(&ref->old_oid, &oid);
 960                 }
 961                 free(private);
 962
 963                 if (ref->peer_ref) {
 964                         if (strcmp(ref->name, ref->peer_ref->name)) {
 965                                 if (!ref->deletion) {
 966                                         const char *name;
 967                                         int flag;
 968
 969                                         /* Follow symbolic refs (mainly for HEAD). */
 970                                         name = resolve_ref_unsafe(ref->peer_ref->name,
 971                                                                   RESOLVE_REF_READING,
 972                                                                   &oid, &flag);
 973                                         if (!name || !(flag & REF_ISSYMREF))
 974                                                 name = ref->peer_ref->name;
 975
 976                                         strbuf_addf(&buf, "%s:%s", name, ref->name);
 977                                 } else
 978                                         strbuf_addf(&buf, ":%s", ref->name);
 979
 980                                 string_list_append(&revlist_args, "--refspec");
 981                                 string_list_append(&revlist_args, buf.buf);
 982                                 strbuf_release(&buf);
 983                         }
 984                         if (!ref->deletion)
 985                                 string_list_append(&revlist_args, ref->peer_ref->name);
 986                 }
 987         }
 988
 989         if (get_exporter(transport, &exporter, &revlist_args))
 990                 die(_("couldn't run fast-export"));
 991
 992         string_list_clear(&revlist_args, 1);
 993
 994         if (finish_command(&exporter))
 995                 die(_("error while running fast-export"));
 996         if (push_update_refs_status(data, remote_refs, flags))
 997                 return 1;
 998
 999         if (data->export_marks) {
1000                 strbuf_addf(&buf, "%s.tmp", data->export_marks);
1001                 rename(buf.buf, data->export_marks);
1002                 strbuf_release(&buf);
1003         }
1004
1005         return 0;
1006 }
1007
1008 static int push_refs(struct transport *transport,
1009                 struct ref *remote_refs, int flags)
1010 {
1011         struct helper_data *data = transport->data;
1012
1013         if (process_connect(transport, 1)) {
1014                 do_take_over(transport);
1015                 return transport->vtable->push_refs(transport, remote_refs, flags);
1016         }
1017
1018         if (!remote_refs) {
1019                 fprintf(stderr,
1020                         _("No refs in common and none specified; doing nothing.\n"
1021                           "Perhaps you should specify a branch such as 'master'.\n"));
1022                 return 0;
1023         }
1024
1025         if (data->push)
1026                 return push_refs_with_push(transport, remote_refs, flags);
1027
1028         if (data->export)
1029                 return push_refs_with_export(transport, remote_refs, flags);
1030
1031         return -1;
1032 }
1033
1034
1035 static int has_attribute(const char *attrs, const char *attr)
1036 {
1037         int len;
1038         if (!attrs)
1039                 return 0;
1040
1041         len = strlen(attr);
1042         for (;;) {
1043                 const char *space = strchrnul(attrs, ' ');
1044                 if (len == space - attrs && !strncmp(attrs, attr, len))
1045                         return 1;
1046                 if (!*space)
1047                         return 0;
1048                 attrs = space + 1;
1049         }
1050 }
1051
1052 static struct ref *get_refs_list(struct transport *transport, int for_push,
1053                                  const struct argv_array *ref_prefixes)
1054 {
1055         struct helper_data *data = transport->data;
1056         struct child_process *helper;
1057         struct ref *ret = NULL;
1058         struct ref **tail = &ret;
1059         struct ref *posn;
1060         struct strbuf buf = STRBUF_INIT;
1061
1062         helper = get_helper(transport);
1063
1064         if (process_connect(transport, for_push)) {
1065                 do_take_over(transport);
1066                 return transport->vtable->get_refs_list(transport, for_push, ref_prefixes);
1067         }
1068
1069         if (data->push && for_push)
1070                 write_str_in_full(helper->in, "list for-push\n");
1071         else
1072                 write_str_in_full(helper->in, "list\n");
1073
1074         while (1) {
1075                 char *eov, *eon;
1076                 if (recvline(data, &buf))
1077                         exit(128);
1078
1079                 if (!*buf.buf)
1080                         break;
1081
1082                 eov = strchr(buf.buf, ' ');
1083                 if (!eov)
1084                         die(_("malformed response in ref list: %s"), buf.buf);
1085                 eon = strchr(eov + 1, ' ');
1086                 *eov = '\0';
1087                 if (eon)
1088                         *eon = '\0';
1089                 *tail = alloc_ref(eov + 1);
1090                 if (buf.buf[0] == '@')
1091                         (*tail)->symref = xstrdup(buf.buf + 1);
1092                 else if (buf.buf[0] != '?')
1093                         get_oid_hex(buf.buf, &(*tail)->old_oid);
1094                 if (eon) {
1095                         if (has_attribute(eon + 1, "unchanged")) {
1096                                 (*tail)->status |= REF_STATUS_UPTODATE;
1097                                 if (read_ref((*tail)->name, &(*tail)->old_oid) < 0)
1098                                         die(_("could not read ref %s"),
1099                                             (*tail)->name);
1100                         }
1101                 }
1102                 tail = &((*tail)->next);
1103         }
1104         if (debug)
1105                 fprintf(stderr, "Debug: Read ref listing.\n");
1106         strbuf_release(&buf);
1107
1108         for (posn = ret; posn; posn = posn->next)
1109                 resolve_remote_symref(posn, ret);
1110
1111         return ret;
1112 }
1113
1114 static struct transport_vtable vtable = {
1115         0,
1116         set_helper_option,
1117         get_refs_list,
1118         fetch,
1119         push_refs,
1120         connect_helper,
1121         release_helper
1122 };
1123
1124 int transport_helper_init(struct transport *transport, const char *name)
1125 {
1126         struct helper_data *data = xcalloc(1, sizeof(*data));
1127         data->name = name;
1128
1129         transport_check_allowed(name);
1130
1131         if (getenv("GIT_TRANSPORT_HELPER_DEBUG"))
1132                 debug = 1;
1133
1134         transport->data = data;
1135         transport->vtable = &vtable;
1136         transport->smart_options = &(data->transport_options);
1137         return 0;
1138 }
1139
1140 /*
1141  * Linux pipes can buffer 65536 bytes at once (and most platforms can
1142  * buffer less), so attempt reads and writes with up to that size.
1143  */
1144 #define BUFFERSIZE 65536
1145 /* This should be enough to hold debugging message. */
1146 #define PBUFFERSIZE 8192
1147
1148 /* Print bidirectional transfer loop debug message. */
1149 __attribute__((format (printf, 1, 2)))
1150 static void transfer_debug(const char *fmt, ...)
1151 {
1152         /*
1153          * NEEDSWORK: This function is sometimes used from multiple threads, and
1154          * we end up using debug_enabled racily. That "should not matter" since
1155          * we always write the same value, but it's still wrong. This function
1156          * is listed in .tsan-suppressions for the time being.
1157          */
1158
1159         va_list args;
1160         char msgbuf[PBUFFERSIZE];
1161         static int debug_enabled = -1;
1162
1163         if (debug_enabled < 0)
1164                 debug_enabled = getenv("GIT_TRANSLOOP_DEBUG") ? 1 : 0;
1165         if (!debug_enabled)
1166                 return;
1167
1168         va_start(args, fmt);
1169         vsnprintf(msgbuf, PBUFFERSIZE, fmt, args);
1170         va_end(args);
1171         fprintf(stderr, "Transfer loop debugging: %s\n", msgbuf);
1172 }
1173
1174 /* Stream state: More data may be coming in this direction. */
1175 #define SSTATE_TRANSFERRING 0
1176 /*
1177  * Stream state: No more data coming in this direction, flushing rest of
1178  * data.
1179  */
1180 #define SSTATE_FLUSHING 1
1181 /* Stream state: Transfer in this direction finished. */
1182 #define SSTATE_FINISHED 2
1183
1184 #define STATE_NEEDS_READING(state) ((state) <= SSTATE_TRANSFERRING)
1185 #define STATE_NEEDS_WRITING(state) ((state) <= SSTATE_FLUSHING)
1186 #define STATE_NEEDS_CLOSING(state) ((state) == SSTATE_FLUSHING)
1187
1188 /* Unidirectional transfer. */
1189 struct unidirectional_transfer {
1190         /* Source */
1191         int src;
1192         /* Destination */
1193         int dest;
1194         /* Is source socket? */
1195         int src_is_sock;
1196         /* Is destination socket? */
1197         int dest_is_sock;
1198         /* Transfer state (TRANSFERRING/FLUSHING/FINISHED) */
1199         int state;
1200         /* Buffer. */
1201         char buf[BUFFERSIZE];
1202         /* Buffer used. */
1203         size_t bufuse;
1204         /* Name of source. */
1205         const char *src_name;
1206         /* Name of destination. */
1207         const char *dest_name;
1208 };
1209
1210 /* Closes the target (for writing) if transfer has finished. */
1211 static void udt_close_if_finished(struct unidirectional_transfer *t)
1212 {
1213         if (STATE_NEEDS_CLOSING(t->state) && !t->bufuse) {
1214                 t->state = SSTATE_FINISHED;
1215                 if (t->dest_is_sock)
1216                         shutdown(t->dest, SHUT_WR);
1217                 else
1218                         close(t->dest);
1219                 transfer_debug("Closed %s.", t->dest_name);
1220         }
1221 }
1222
1223 /*
1224  * Tries to read data from source into buffer. If buffer is full,
1225  * no data is read. Returns 0 on success, -1 on error.
1226  */
1227 static int udt_do_read(struct unidirectional_transfer *t)
1228 {
1229         ssize_t bytes;
1230
1231         if (t->bufuse == BUFFERSIZE)
1232                 return 0;       /* No space for more. */
1233
1234         transfer_debug("%s is readable", t->src_name);
1235         bytes = xread(t->src, t->buf + t->bufuse, BUFFERSIZE - t->bufuse);
1236         if (bytes < 0) {
1237                 error_errno(_("read(%s) failed"), t->src_name);
1238                 return -1;
1239         } else if (bytes == 0) {
1240                 transfer_debug("%s EOF (with %i bytes in buffer)",
1241                         t->src_name, (int)t->bufuse);
1242                 t->state = SSTATE_FLUSHING;
1243         } else if (bytes > 0) {
1244                 t->bufuse += bytes;
1245                 transfer_debug("Read %i bytes from %s (buffer now at %i)",
1246                         (int)bytes, t->src_name, (int)t->bufuse);
1247         }
1248         return 0;
1249 }
1250
1251 /* Tries to write data from buffer into destination. If buffer is empty,
1252  * no data is written. Returns 0 on success, -1 on error.
1253  */
1254 static int udt_do_write(struct unidirectional_transfer *t)
1255 {
1256         ssize_t bytes;
1257
1258         if (t->bufuse == 0)
1259                 return 0;       /* Nothing to write. */
1260
1261         transfer_debug("%s is writable", t->dest_name);
1262         bytes = xwrite(t->dest, t->buf, t->bufuse);
1263         if (bytes < 0) {
1264                 error_errno(_("write(%s) failed"), t->dest_name);
1265                 return -1;
1266         } else if (bytes > 0) {
1267                 t->bufuse -= bytes;
1268                 if (t->bufuse)
1269                         memmove(t->buf, t->buf + bytes, t->bufuse);
1270                 transfer_debug("Wrote %i bytes to %s (buffer now at %i)",
1271                         (int)bytes, t->dest_name, (int)t->bufuse);
1272         }
1273         return 0;
1274 }
1275
1276
1277 /* State of bidirectional transfer loop. */
1278 struct bidirectional_transfer_state {
1279         /* Direction from program to git. */
1280         struct unidirectional_transfer ptg;
1281         /* Direction from git to program. */
1282         struct unidirectional_transfer gtp;
1283 };
1284
1285 static void *udt_copy_task_routine(void *udt)
1286 {
1287         struct unidirectional_transfer *t = (struct unidirectional_transfer *)udt;
1288         while (t->state != SSTATE_FINISHED) {
1289                 if (STATE_NEEDS_READING(t->state))
1290                         if (udt_do_read(t))
1291                                 return NULL;
1292                 if (STATE_NEEDS_WRITING(t->state))
1293                         if (udt_do_write(t))
1294                                 return NULL;
1295                 if (STATE_NEEDS_CLOSING(t->state))
1296                         udt_close_if_finished(t);
1297         }
1298         return udt;     /* Just some non-NULL value. */
1299 }
1300
1301 #ifndef NO_PTHREADS
1302
1303 /*
1304  * Join thread, with appropriate errors on failure. Name is name for the
1305  * thread (for error messages). Returns 0 on success, 1 on failure.
1306  */
1307 static int tloop_join(pthread_t thread, const char *name)
1308 {
1309         int err;
1310         void *tret;
1311         err = pthread_join(thread, &tret);
1312         if (!tret) {
1313                 error(_("%s thread failed"), name);
1314                 return 1;
1315         }
1316         if (err) {
1317                 error(_("%s thread failed to join: %s"), name, strerror(err));
1318                 return 1;
1319         }
1320         return 0;
1321 }
1322
1323 /*
1324  * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1325  * -1 on failure.
1326  */
1327 static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1328 {
1329         pthread_t gtp_thread;
1330         pthread_t ptg_thread;
1331         int err;
1332         int ret = 0;
1333         err = pthread_create(&gtp_thread, NULL, udt_copy_task_routine,
1334                 &s->gtp);
1335         if (err)
1336                 die(_("can't start thread for copying data: %s"), strerror(err));
1337         err = pthread_create(&ptg_thread, NULL, udt_copy_task_routine,
1338                 &s->ptg);
1339         if (err)
1340                 die(_("can't start thread for copying data: %s"), strerror(err));
1341
1342         ret |= tloop_join(gtp_thread, "Git to program copy");
1343         ret |= tloop_join(ptg_thread, "Program to git copy");
1344         return ret;
1345 }
1346 #else
1347
1348 /* Close the source and target (for writing) for transfer. */
1349 static void udt_kill_transfer(struct unidirectional_transfer *t)
1350 {
1351         t->state = SSTATE_FINISHED;
1352         /*
1353          * Socket read end left open isn't a disaster if nobody
1354          * attempts to read from it (mingw compat headers do not
1355          * have SHUT_RD)...
1356          *
1357          * We can't fully close the socket since otherwise gtp
1358          * task would first close the socket it sends data to
1359          * while closing the ptg file descriptors.
1360          */
1361         if (!t->src_is_sock)
1362                 close(t->src);
1363         if (t->dest_is_sock)
1364                 shutdown(t->dest, SHUT_WR);
1365         else
1366                 close(t->dest);
1367 }
1368
1369 /*
1370  * Join process, with appropriate errors on failure. Name is name for the
1371  * process (for error messages). Returns 0 on success, 1 on failure.
1372  */
1373 static int tloop_join(pid_t pid, const char *name)
1374 {
1375         int tret;
1376         if (waitpid(pid, &tret, 0) < 0) {
1377                 error_errno(_("%s process failed to wait"), name);
1378                 return 1;
1379         }
1380         if (!WIFEXITED(tret) || WEXITSTATUS(tret)) {
1381                 error(_("%s process failed"), name);
1382                 return 1;
1383         }
1384         return 0;
1385 }
1386
1387 /*
1388  * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1389  * -1 on failure.
1390  */
1391 static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1392 {
1393         pid_t pid1, pid2;
1394         int ret = 0;
1395
1396         /* Fork thread #1: git to program. */
1397         pid1 = fork();
1398         if (pid1 < 0)
1399                 die_errno(_("can't start thread for copying data"));
1400         else if (pid1 == 0) {
1401                 udt_kill_transfer(&s->ptg);
1402                 exit(udt_copy_task_routine(&s->gtp) ? 0 : 1);
1403         }
1404
1405         /* Fork thread #2: program to git. */
1406         pid2 = fork();
1407         if (pid2 < 0)
1408                 die_errno(_("can't start thread for copying data"));
1409         else if (pid2 == 0) {
1410                 udt_kill_transfer(&s->gtp);
1411                 exit(udt_copy_task_routine(&s->ptg) ? 0 : 1);
1412         }
1413
1414         /*
1415          * Close both streams in parent as to not interfere with
1416          * end of file detection and wait for both tasks to finish.
1417          */
1418         udt_kill_transfer(&s->gtp);
1419         udt_kill_transfer(&s->ptg);
1420         ret |= tloop_join(pid1, "Git to program copy");
1421         ret |= tloop_join(pid2, "Program to git copy");
1422         return ret;
1423 }
1424 #endif
1425
1426 /*
1427  * Copies data from stdin to output and from input to stdout simultaneously.
1428  * Additionally filtering through given filter. If filter is NULL, uses
1429  * identity filter.
1430  */
1431 int bidirectional_transfer_loop(int input, int output)
1432 {
1433         struct bidirectional_transfer_state state;
1434
1435         /* Fill the state fields. */
1436         state.ptg.src = input;
1437         state.ptg.dest = 1;
1438         state.ptg.src_is_sock = (input == output);
1439         state.ptg.dest_is_sock = 0;
1440         state.ptg.state = SSTATE_TRANSFERRING;
1441         state.ptg.bufuse = 0;
1442         state.ptg.src_name = "remote input";
1443         state.ptg.dest_name = "stdout";
1444
1445         state.gtp.src = 0;
1446         state.gtp.dest = output;
1447         state.gtp.src_is_sock = 0;
1448         state.gtp.dest_is_sock = (input == output);
1449         state.gtp.state = SSTATE_TRANSFERRING;
1450         state.gtp.bufuse = 0;
1451         state.gtp.src_name = "stdin";
1452         state.gtp.dest_name = "remote output";
1453
1454         return tloop_spawnwait_tasks(&state);
1455 }