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
  15 static int debug;
  16
  17 struct helper_data {
  18         const char *name;
  19         struct child_process *helper;
  20         FILE *out;
  21         unsigned fetch : 1,
  22                 import : 1,
  23                 bidi_import : 1,
  24                 export : 1,
  25                 option : 1,
  26                 push : 1,
  27                 connect : 1,
  28                 signed_tags : 1,
  29                 check_connectivity : 1,
  30                 no_disconnect_req : 1,
  31                 no_private_update : 1;
  32         char *export_marks;
  33         char *import_marks;
  34         /* These go from remote name (as in "list") to private name */
  35         struct refspec *refspecs;
  36         int refspec_nr;
  37         /* Transport options for fetch-pack/send-pack (should one of
  38          * those be invoked).
  39          */
  40         struct git_transport_options transport_options;
  41 };
  42
  43 static void sendline(struct helper_data *helper, struct strbuf *buffer)
  44 {
  45         if (debug)
  46                 fprintf(stderr, "Debug: Remote helper: -> %s", buffer->buf);
  47         if (write_in_full(helper->helper->in, buffer->buf, buffer->len)
  48                 != buffer->len)
  49                 die_errno("Full write to remote helper failed");
  50 }
  51
  52 static int recvline_fh(FILE *helper, struct strbuf *buffer, const char *name)
  53 {
  54         strbuf_reset(buffer);
  55         if (debug)
  56                 fprintf(stderr, "Debug: Remote helper: Waiting...\n");
  57         if (strbuf_getline(buffer, helper) == EOF) {
  58                 if (debug)
  59                         fprintf(stderr, "Debug: Remote helper quit.\n");
  60                 return 1;
  61         }
  62
  63         if (debug)
  64                 fprintf(stderr, "Debug: Remote helper: <- %s\n", buffer->buf);
  65         return 0;
  66 }
  67
  68 static int recvline(struct helper_data *helper, struct strbuf *buffer)
  69 {
  70         return recvline_fh(helper->out, buffer, helper->name);
  71 }
  72
  73 static void write_constant(int fd, const char *str)
  74 {
  75         if (debug)
  76                 fprintf(stderr, "Debug: Remote helper: -> %s", str);
  77         if (write_in_full(fd, str, strlen(str)) != strlen(str))
  78                 die_errno("Full write to remote helper failed");
  79 }
  80
  81 static const char *remove_ext_force(const char *url)
  82 {
  83         if (url) {
  84                 const char *colon = strchr(url, ':');
  85                 if (colon && colon[1] == ':')
  86                         return colon + 2;
  87         }
  88         return url;
  89 }
  90
  91 static void do_take_over(struct transport *transport)
  92 {
  93         struct helper_data *data;
  94         data = (struct helper_data *)transport->data;
  95         transport_take_over(transport, data->helper);
  96         fclose(data->out);
  97         free(data);
  98 }
  99
 100 static void standard_options(struct transport *t);
 101
 102 static struct child_process *get_helper(struct transport *transport)
 103 {
 104         struct helper_data *data = transport->data;
 105         struct strbuf buf = STRBUF_INIT;
 106         struct child_process *helper;
 107         const char **refspecs = NULL;
 108         int refspec_nr = 0;
 109         int refspec_alloc = 0;
 110         int duped;
 111         int code;
 112
 113         if (data->helper)
 114                 return data->helper;
 115
 116         helper = xmalloc(sizeof(*helper));
 117         child_process_init(helper);
 118         helper->in = -1;
 119         helper->out = -1;
 120         helper->err = 0;
 121         argv_array_pushf(&helper->args, "git-remote-%s", data->name);
 122         argv_array_push(&helper->args, transport->remote->name);
 123         argv_array_push(&helper->args, remove_ext_force(transport->url));
 124         helper->git_cmd = 0;
 125         helper->silent_exec_failure = 1;
 126
 127         if (have_git_dir())
 128                 argv_array_pushf(&helper->env_array, "%s=%s",
 129                                  GIT_DIR_ENVIRONMENT, get_git_dir());
 130
 131         code = start_command(helper);
 132         if (code < 0 && errno == ENOENT)
 133                 die("Unable to find remote helper for '%s'", data->name);
 134         else if (code != 0)
 135                 exit(code);
 136
 137         data->helper = helper;
 138         data->no_disconnect_req = 0;
 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 (!data->refspecs && skip_prefix(capname, "refspec ", &arg)) {
 185                         ALLOC_GROW(refspecs,
 186                                    refspec_nr + 1,
 187                                    refspec_alloc);
 188                         refspecs[refspec_nr++] = xstrdup(arg);
 189                 } else if (!strcmp(capname, "connect")) {
 190                         data->connect = 1;
 191                 } else if (!strcmp(capname, "signed-tags")) {
 192                         data->signed_tags = 1;
 193                 } else if (skip_prefix(capname, "export-marks ", &arg)) {
 194                         data->export_marks = xstrdup(arg);
 195                 } else if (skip_prefix(capname, "import-marks ", &arg)) {
 196                         data->import_marks = xstrdup(arg);
 197                 } else if (starts_with(capname, "no-private-update")) {
 198                         data->no_private_update = 1;
 199                 } else if (mandatory) {
 200                         die("Unknown mandatory capability %s. This remote "
 201                             "helper probably needs newer version of Git.",
 202                             capname);
 203                 }
 204         }
 205         if (refspecs) {
 206                 int i;
 207                 data->refspec_nr = refspec_nr;
 208                 data->refspecs = parse_fetch_refspec(refspec_nr, refspecs);
 209                 for (i = 0; i < refspec_nr; i++)
 210                         free((char *)refspecs[i]);
 211                 free(refspecs);
 212         } else if (data->import || data->bidi_import || data->export) {
 213                 warning("This remote helper should implement refspec capability.");
 214         }
 215         strbuf_release(&buf);
 216         if (debug)
 217                 fprintf(stderr, "Debug: Capabilities complete.\n");
 218         standard_options(transport);
 219         return data->helper;
 220 }
 221
 222 static int disconnect_helper(struct transport *transport)
 223 {
 224         struct helper_data *data = transport->data;
 225         int res = 0;
 226
 227         if (data->helper) {
 228                 if (debug)
 229                         fprintf(stderr, "Debug: Disconnecting.\n");
 230                 if (!data->no_disconnect_req) {
 231                         /*
 232                          * Ignore write errors; there's nothing we can do,
 233                          * since we're about to close the pipe anyway. And the
 234                          * most likely error is EPIPE due to the helper dying
 235                          * to report an error itself.
 236                          */
 237                         sigchain_push(SIGPIPE, SIG_IGN);
 238                         xwrite(data->helper->in, "\n", 1);
 239                         sigchain_pop(SIGPIPE);
 240                 }
 241                 close(data->helper->in);
 242                 close(data->helper->out);
 243                 fclose(data->out);
 244                 res = finish_command(data->helper);
 245                 free(data->helper);
 246                 data->helper = NULL;
 247         }
 248         return res;
 249 }
 250
 251 static const char *unsupported_options[] = {
 252         TRANS_OPT_UPLOADPACK,
 253         TRANS_OPT_RECEIVEPACK,
 254         TRANS_OPT_THIN,
 255         TRANS_OPT_KEEP
 256         };
 257
 258 static const char *boolean_options[] = {
 259         TRANS_OPT_THIN,
 260         TRANS_OPT_KEEP,
 261         TRANS_OPT_FOLLOWTAGS,
 262         TRANS_OPT_DEEPEN_RELATIVE
 263         };
 264
 265 static int strbuf_set_helper_option(struct helper_data *data,
 266                                     struct strbuf *buf)
 267 {
 268         int ret;
 269
 270         sendline(data, buf);
 271         if (recvline(data, buf))
 272                 exit(128);
 273
 274         if (!strcmp(buf->buf, "ok"))
 275                 ret = 0;
 276         else if (starts_with(buf->buf, "error"))
 277                 ret = -1;
 278         else if (!strcmp(buf->buf, "unsupported"))
 279                 ret = 1;
 280         else {
 281                 warning("%s unexpectedly said: '%s'", data->name, buf->buf);
 282                 ret = 1;
 283         }
 284         return ret;
 285 }
 286
 287 static int string_list_set_helper_option(struct helper_data *data,
 288                                          const char *name,
 289                                          struct string_list *list)
 290 {
 291         struct strbuf buf = STRBUF_INIT;
 292         int i, ret = 0;
 293
 294         for (i = 0; i < list->nr; i++) {
 295                 strbuf_addf(&buf, "option %s ", name);
 296                 quote_c_style(list->items[i].string, &buf, NULL, 0);
 297                 strbuf_addch(&buf, '\n');
 298
 299                 if ((ret = strbuf_set_helper_option(data, &buf)))
 300                         break;
 301                 strbuf_reset(&buf);
 302         }
 303         strbuf_release(&buf);
 304         return ret;
 305 }
 306
 307 static int set_helper_option(struct transport *transport,
 308                           const char *name, const char *value)
 309 {
 310         struct helper_data *data = transport->data;
 311         struct strbuf buf = STRBUF_INIT;
 312         int i, ret, is_bool = 0;
 313
 314         get_helper(transport);
 315
 316         if (!data->option)
 317                 return 1;
 318
 319         if (!strcmp(name, "deepen-not"))
 320                 return string_list_set_helper_option(data, name,
 321                                                      (struct string_list *)value);
 322
 323         for (i = 0; i < ARRAY_SIZE(unsupported_options); i++) {
 324                 if (!strcmp(name, unsupported_options[i]))
 325                         return 1;
 326         }
 327
 328         for (i = 0; i < ARRAY_SIZE(boolean_options); i++) {
 329                 if (!strcmp(name, boolean_options[i])) {
 330                         is_bool = 1;
 331                         break;
 332                 }
 333         }
 334
 335         strbuf_addf(&buf, "option %s ", name);
 336         if (is_bool)
 337                 strbuf_addstr(&buf, value ? "true" : "false");
 338         else
 339                 quote_c_style(value, &buf, NULL, 0);
 340         strbuf_addch(&buf, '\n');
 341
 342         ret = strbuf_set_helper_option(data, &buf);
 343         strbuf_release(&buf);
 344         return ret;
 345 }
 346
 347 static void standard_options(struct transport *t)
 348 {
 349         char buf[16];
 350         int n;
 351         int v = t->verbose;
 352
 353         set_helper_option(t, "progress", t->progress ? "true" : "false");
 354
 355         n = snprintf(buf, sizeof(buf), "%d", v + 1);
 356         if (n >= sizeof(buf))
 357                 die("impossibly large verbosity value");
 358         set_helper_option(t, "verbosity", buf);
 359
 360         switch (t->family) {
 361         case TRANSPORT_FAMILY_ALL:
 362                 /*
 363                  * this is already the default,
 364                  * do not break old remote helpers by setting "all" here
 365                  */
 366                 break;
 367         case TRANSPORT_FAMILY_IPV4:
 368                 set_helper_option(t, "family", "ipv4");
 369                 break;
 370         case TRANSPORT_FAMILY_IPV6:
 371                 set_helper_option(t, "family", "ipv6");
 372                 break;
 373         }
 374 }
 375
 376 static int release_helper(struct transport *transport)
 377 {
 378         int res = 0;
 379         struct helper_data *data = transport->data;
 380         free_refspec(data->refspec_nr, data->refspecs);
 381         data->refspecs = NULL;
 382         res = disconnect_helper(transport);
 383         free(transport->data);
 384         return res;
 385 }
 386
 387 static int fetch_with_fetch(struct transport *transport,
 388                             int nr_heads, struct ref **to_fetch)
 389 {
 390         struct helper_data *data = transport->data;
 391         int i;
 392         struct strbuf buf = STRBUF_INIT;
 393
 394         for (i = 0; i < nr_heads; i++) {
 395                 const struct ref *posn = to_fetch[i];
 396                 if (posn->status & REF_STATUS_UPTODATE)
 397                         continue;
 398
 399                 strbuf_addf(&buf, "fetch %s %s\n",
 400                             oid_to_hex(&posn->old_oid),
 401                             posn->symref ? posn->symref : posn->name);
 402         }
 403
 404         strbuf_addch(&buf, '\n');
 405         sendline(data, &buf);
 406
 407         while (1) {
 408                 if (recvline(data, &buf))
 409                         exit(128);
 410
 411                 if (starts_with(buf.buf, "lock ")) {
 412                         const char *name = buf.buf + 5;
 413                         if (transport->pack_lockfile)
 414                                 warning("%s also locked %s", data->name, name);
 415                         else
 416                                 transport->pack_lockfile = xstrdup(name);
 417                 }
 418                 else if (data->check_connectivity &&
 419                          data->transport_options.check_self_contained_and_connected &&
 420                          !strcmp(buf.buf, "connectivity-ok"))
 421                         data->transport_options.self_contained_and_connected = 1;
 422                 else if (!buf.len)
 423                         break;
 424                 else
 425                         warning("%s unexpectedly said: '%s'", data->name, buf.buf);
 426         }
 427         strbuf_release(&buf);
 428         return 0;
 429 }
 430
 431 static int get_importer(struct transport *transport, struct child_process *fastimport)
 432 {
 433         struct child_process *helper = get_helper(transport);
 434         struct helper_data *data = transport->data;
 435         int cat_blob_fd, code;
 436         child_process_init(fastimport);
 437         fastimport->in = helper->out;
 438         argv_array_push(&fastimport->args, "fast-import");
 439         argv_array_push(&fastimport->args, debug ? "--stats" : "--quiet");
 440
 441         if (data->bidi_import) {
 442                 cat_blob_fd = xdup(helper->in);
 443                 argv_array_pushf(&fastimport->args, "--cat-blob-fd=%d", cat_blob_fd);
 444         }
 445         fastimport->git_cmd = 1;
 446
 447         code = start_command(fastimport);
 448         return code;
 449 }
 450
 451 static int get_exporter(struct transport *transport,
 452                         struct child_process *fastexport,
 453                         struct string_list *revlist_args)
 454 {
 455         struct helper_data *data = transport->data;
 456         struct child_process *helper = get_helper(transport);
 457         int i;
 458
 459         child_process_init(fastexport);
 460
 461         /* we need to duplicate helper->in because we want to use it after
 462          * fastexport is done with it. */
 463         fastexport->out = dup(helper->in);
 464         argv_array_push(&fastexport->args, "fast-export");
 465         argv_array_push(&fastexport->args, "--use-done-feature");
 466         argv_array_push(&fastexport->args, data->signed_tags ?
 467                 "--signed-tags=verbatim" : "--signed-tags=warn-strip");
 468         if (data->export_marks)
 469                 argv_array_pushf(&fastexport->args, "--export-marks=%s.tmp", data->export_marks);
 470         if (data->import_marks)
 471                 argv_array_pushf(&fastexport->args, "--import-marks=%s", data->import_marks);
 472
 473         for (i = 0; i < revlist_args->nr; i++)
 474                 argv_array_push(&fastexport->args, revlist_args->items[i].string);
 475
 476         fastexport->git_cmd = 1;
 477         return start_command(fastexport);
 478 }
 479
 480 static int fetch_with_import(struct transport *transport,
 481                              int nr_heads, struct ref **to_fetch)
 482 {
 483         struct child_process fastimport;
 484         struct helper_data *data = transport->data;
 485         int i;
 486         struct ref *posn;
 487         struct strbuf buf = STRBUF_INIT;
 488
 489         get_helper(transport);
 490
 491         if (get_importer(transport, &fastimport))
 492                 die("Couldn't run fast-import");
 493
 494         for (i = 0; i < nr_heads; i++) {
 495                 posn = to_fetch[i];
 496                 if (posn->status & REF_STATUS_UPTODATE)
 497                         continue;
 498
 499                 strbuf_addf(&buf, "import %s\n",
 500                             posn->symref ? posn->symref : posn->name);
 501                 sendline(data, &buf);
 502                 strbuf_reset(&buf);
 503         }
 504
 505         write_constant(data->helper->in, "\n");
 506         /*
 507          * remote-helpers that advertise the bidi-import capability are required to
 508          * buffer the complete batch of import commands until this newline before
 509          * sending data to fast-import.
 510          * These helpers read back data from fast-import on their stdin, which could
 511          * be mixed with import commands, otherwise.
 512          */
 513
 514         if (finish_command(&fastimport))
 515                 die("Error while running fast-import");
 516
 517         /*
 518          * The fast-import stream of a remote helper that advertises
 519          * the "refspec" capability writes to the refs named after the
 520          * right hand side of the first refspec matching each ref we
 521          * were fetching.
 522          *
 523          * (If no "refspec" capability was specified, for historical
 524          * reasons we default to the equivalent of *:*.)
 525          *
 526          * Store the result in to_fetch[i].old_sha1.  Callers such
 527          * as "git fetch" can use the value to write feedback to the
 528          * terminal, populate FETCH_HEAD, and determine what new value
 529          * should be written to peer_ref if the update is a
 530          * fast-forward or this is a forced update.
 531          */
 532         for (i = 0; i < nr_heads; i++) {
 533                 char *private, *name;
 534                 posn = to_fetch[i];
 535                 if (posn->status & REF_STATUS_UPTODATE)
 536                         continue;
 537                 name = posn->symref ? posn->symref : posn->name;
 538                 if (data->refspecs)
 539                         private = apply_refspecs(data->refspecs, data->refspec_nr, name);
 540                 else
 541                         private = xstrdup(name);
 542                 if (private) {
 543                         if (read_ref(private, posn->old_oid.hash) < 0)
 544                                 die("Could not read ref %s", private);
 545                         free(private);
 546                 }
 547         }
 548         strbuf_release(&buf);
 549         return 0;
 550 }
 551
 552 static int process_connect_service(struct transport *transport,
 553                                    const char *name, const char *exec)
 554 {
 555         struct helper_data *data = transport->data;
 556         struct strbuf cmdbuf = STRBUF_INIT;
 557         struct child_process *helper;
 558         int r, duped, ret = 0;
 559         FILE *input;
 560
 561         helper = get_helper(transport);
 562
 563         /*
 564          * Yes, dup the pipe another time, as we need unbuffered version
 565          * of input pipe as FILE*. fclose() closes the underlying fd and
 566          * stream buffering only can be changed before first I/O operation
 567          * on it.
 568          */
 569         duped = dup(helper->out);
 570         if (duped < 0)
 571                 die_errno("Can't dup helper output fd");
 572         input = xfdopen(duped, "r");
 573         setvbuf(input, NULL, _IONBF, 0);
 574
 575         /*
 576          * Handle --upload-pack and friends. This is fire and forget...
 577          * just warn if it fails.
 578          */
 579         if (strcmp(name, exec)) {
 580                 r = set_helper_option(transport, "servpath", exec);
 581                 if (r > 0)
 582                         warning("Setting remote service path not supported by protocol.");
 583                 else if (r < 0)
 584                         warning("Invalid remote service path.");
 585         }
 586
 587         if (data->connect)
 588                 strbuf_addf(&cmdbuf, "connect %s\n", name);
 589         else
 590                 goto exit;
 591
 592         sendline(data, &cmdbuf);
 593         if (recvline_fh(input, &cmdbuf, name))
 594                 exit(128);
 595
 596         if (!strcmp(cmdbuf.buf, "")) {
 597                 data->no_disconnect_req = 1;
 598                 if (debug)
 599                         fprintf(stderr, "Debug: Smart transport connection "
 600                                 "ready.\n");
 601                 ret = 1;
 602         } else if (!strcmp(cmdbuf.buf, "fallback")) {
 603                 if (debug)
 604                         fprintf(stderr, "Debug: Falling back to dumb "
 605                                 "transport.\n");
 606         } else
 607                 die("Unknown response to connect: %s",
 608                         cmdbuf.buf);
 609
 610 exit:
 611         fclose(input);
 612         return ret;
 613 }
 614
 615 static int process_connect(struct transport *transport,
 616                                      int for_push)
 617 {
 618         struct helper_data *data = transport->data;
 619         const char *name;
 620         const char *exec;
 621
 622         name = for_push ? "git-receive-pack" : "git-upload-pack";
 623         if (for_push)
 624                 exec = data->transport_options.receivepack;
 625         else
 626                 exec = data->transport_options.uploadpack;
 627
 628         return process_connect_service(transport, name, exec);
 629 }
 630
 631 static int connect_helper(struct transport *transport, const char *name,
 632                    const char *exec, int fd[2])
 633 {
 634         struct helper_data *data = transport->data;
 635
 636         /* Get_helper so connect is inited. */
 637         get_helper(transport);
 638         if (!data->connect)
 639                 die("Operation not supported by protocol.");
 640
 641         if (!process_connect_service(transport, name, exec))
 642                 die("Can't connect to subservice %s.", name);
 643
 644         fd[0] = data->helper->out;
 645         fd[1] = data->helper->in;
 646         return 0;
 647 }
 648
 649 static int fetch(struct transport *transport,
 650                  int nr_heads, struct ref **to_fetch)
 651 {
 652         struct helper_data *data = transport->data;
 653         int i, count;
 654
 655         if (process_connect(transport, 0)) {
 656                 do_take_over(transport);
 657                 return transport->fetch(transport, nr_heads, to_fetch);
 658         }
 659
 660         count = 0;
 661         for (i = 0; i < nr_heads; i++)
 662                 if (!(to_fetch[i]->status & REF_STATUS_UPTODATE))
 663                         count++;
 664
 665         if (!count)
 666                 return 0;
 667
 668         if (data->check_connectivity &&
 669             data->transport_options.check_self_contained_and_connected)
 670                 set_helper_option(transport, "check-connectivity", "true");
 671
 672         if (transport->cloning)
 673                 set_helper_option(transport, "cloning", "true");
 674
 675         if (data->transport_options.update_shallow)
 676                 set_helper_option(transport, "update-shallow", "true");
 677
 678         if (data->fetch)
 679                 return fetch_with_fetch(transport, nr_heads, to_fetch);
 680
 681         if (data->import)
 682                 return fetch_with_import(transport, nr_heads, to_fetch);
 683
 684         return -1;
 685 }
 686
 687 static int push_update_ref_status(struct strbuf *buf,
 688                                    struct ref **ref,
 689                                    struct ref *remote_refs)
 690 {
 691         char *refname, *msg;
 692         int status, forced = 0;
 693
 694         if (starts_with(buf->buf, "ok ")) {
 695                 status = REF_STATUS_OK;
 696                 refname = buf->buf + 3;
 697         } else if (starts_with(buf->buf, "error ")) {
 698                 status = REF_STATUS_REMOTE_REJECT;
 699                 refname = buf->buf + 6;
 700         } else
 701                 die("expected ok/error, helper said '%s'", buf->buf);
 702
 703         msg = strchr(refname, ' ');
 704         if (msg) {
 705                 struct strbuf msg_buf = STRBUF_INIT;
 706                 const char *end;
 707
 708                 *msg++ = '\0';
 709                 if (!unquote_c_style(&msg_buf, msg, &end))
 710                         msg = strbuf_detach(&msg_buf, NULL);
 711                 else
 712                         msg = xstrdup(msg);
 713                 strbuf_release(&msg_buf);
 714
 715                 if (!strcmp(msg, "no match")) {
 716                         status = REF_STATUS_NONE;
 717                         free(msg);
 718                         msg = NULL;
 719                 }
 720                 else if (!strcmp(msg, "up to date")) {
 721                         status = REF_STATUS_UPTODATE;
 722                         free(msg);
 723                         msg = NULL;
 724                 }
 725                 else if (!strcmp(msg, "non-fast forward")) {
 726                         status = REF_STATUS_REJECT_NONFASTFORWARD;
 727                         free(msg);
 728                         msg = NULL;
 729                 }
 730                 else if (!strcmp(msg, "already exists")) {
 731                         status = REF_STATUS_REJECT_ALREADY_EXISTS;
 732                         free(msg);
 733                         msg = NULL;
 734                 }
 735                 else if (!strcmp(msg, "fetch first")) {
 736                         status = REF_STATUS_REJECT_FETCH_FIRST;
 737                         free(msg);
 738                         msg = NULL;
 739                 }
 740                 else if (!strcmp(msg, "needs force")) {
 741                         status = REF_STATUS_REJECT_NEEDS_FORCE;
 742                         free(msg);
 743                         msg = NULL;
 744                 }
 745                 else if (!strcmp(msg, "stale info")) {
 746                         status = REF_STATUS_REJECT_STALE;
 747                         free(msg);
 748                         msg = NULL;
 749                 }
 750                 else if (!strcmp(msg, "forced update")) {
 751                         forced = 1;
 752                         free(msg);
 753                         msg = NULL;
 754                 }
 755         }
 756
 757         if (*ref)
 758                 *ref = find_ref_by_name(*ref, refname);
 759         if (!*ref)
 760                 *ref = find_ref_by_name(remote_refs, refname);
 761         if (!*ref) {
 762                 warning("helper reported unexpected status of %s", refname);
 763                 return 1;
 764         }
 765
 766         if ((*ref)->status != REF_STATUS_NONE) {
 767                 /*
 768                  * Earlier, the ref was marked not to be pushed, so ignore the ref
 769                  * status reported by the remote helper if the latter is 'no match'.
 770                  */
 771                 if (status == REF_STATUS_NONE)
 772                         return 1;
 773         }
 774
 775         (*ref)->status = status;
 776         (*ref)->forced_update |= forced;
 777         (*ref)->remote_status = msg;
 778         return !(status == REF_STATUS_OK);
 779 }
 780
 781 static int push_update_refs_status(struct helper_data *data,
 782                                     struct ref *remote_refs,
 783                                     int flags)
 784 {
 785         struct strbuf buf = STRBUF_INIT;
 786         struct ref *ref = remote_refs;
 787         int ret = 0;
 788
 789         for (;;) {
 790                 char *private;
 791
 792                 if (recvline(data, &buf)) {
 793                         ret = 1;
 794                         break;
 795                 }
 796
 797                 if (!buf.len)
 798                         break;
 799
 800                 if (push_update_ref_status(&buf, &ref, remote_refs))
 801                         continue;
 802
 803                 if (flags & TRANSPORT_PUSH_DRY_RUN || !data->refspecs || data->no_private_update)
 804                         continue;
 805
 806                 /* propagate back the update to the remote namespace */
 807                 private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
 808                 if (!private)
 809                         continue;
 810                 update_ref("update by helper", private, ref->new_oid.hash, NULL, 0, 0);
 811                 free(private);
 812         }
 813         strbuf_release(&buf);
 814         return ret;
 815 }
 816
 817 static void set_common_push_options(struct transport *transport,
 818                                    const char *name, int flags)
 819 {
 820         if (flags & TRANSPORT_PUSH_DRY_RUN) {
 821                 if (set_helper_option(transport, "dry-run", "true") != 0)
 822                         die("helper %s does not support dry-run", name);
 823         } else if (flags & TRANSPORT_PUSH_CERT_ALWAYS) {
 824                 if (set_helper_option(transport, TRANS_OPT_PUSH_CERT, "true") != 0)
 825                         die("helper %s does not support --signed", name);
 826         } else if (flags & TRANSPORT_PUSH_CERT_IF_ASKED) {
 827                 if (set_helper_option(transport, TRANS_OPT_PUSH_CERT, "if-asked") != 0)
 828                         die("helper %s does not support --signed=if-asked", name);
 829         }
 830
 831         if (flags & TRANSPORT_PUSH_OPTIONS) {
 832                 struct string_list_item *item;
 833                 for_each_string_list_item(item, transport->push_options)
 834                         if (set_helper_option(transport, "push-option", item->string) != 0)
 835                                 die("helper %s does not support 'push-option'", name);
 836         }
 837 }
 838
 839 static int push_refs_with_push(struct transport *transport,
 840                                struct ref *remote_refs, int flags)
 841 {
 842         int force_all = flags & TRANSPORT_PUSH_FORCE;
 843         int mirror = flags & TRANSPORT_PUSH_MIRROR;
 844         struct helper_data *data = transport->data;
 845         struct strbuf buf = STRBUF_INIT;
 846         struct ref *ref;
 847         struct string_list cas_options = STRING_LIST_INIT_DUP;
 848         struct string_list_item *cas_option;
 849
 850         get_helper(transport);
 851         if (!data->push)
 852                 return 1;
 853
 854         for (ref = remote_refs; ref; ref = ref->next) {
 855                 if (!ref->peer_ref && !mirror)
 856                         continue;
 857
 858                 /* Check for statuses set by set_ref_status_for_push() */
 859                 switch (ref->status) {
 860                 case REF_STATUS_REJECT_NONFASTFORWARD:
 861                 case REF_STATUS_REJECT_STALE:
 862                 case REF_STATUS_REJECT_ALREADY_EXISTS:
 863                 case REF_STATUS_UPTODATE:
 864                         continue;
 865                 default:
 866                         ; /* do nothing */
 867                 }
 868
 869                 if (force_all)
 870                         ref->force = 1;
 871
 872                 strbuf_addstr(&buf, "push ");
 873                 if (!ref->deletion) {
 874                         if (ref->force)
 875                                 strbuf_addch(&buf, '+');
 876                         if (ref->peer_ref)
 877                                 strbuf_addstr(&buf, ref->peer_ref->name);
 878                         else
 879                                 strbuf_addstr(&buf, oid_to_hex(&ref->new_oid));
 880                 }
 881                 strbuf_addch(&buf, ':');
 882                 strbuf_addstr(&buf, ref->name);
 883                 strbuf_addch(&buf, '\n');
 884
 885                 /*
 886                  * The "--force-with-lease" options without explicit
 887                  * values to expect have already been expanded into
 888                  * the ref->old_oid_expect[] field; we can ignore
 889                  * transport->smart_options->cas altogether and instead
 890                  * can enumerate them from the refs.
 891                  */
 892                 if (ref->expect_old_sha1) {
 893                         struct strbuf cas = STRBUF_INIT;
 894                         strbuf_addf(&cas, "%s:%s",
 895                                     ref->name, oid_to_hex(&ref->old_oid_expect));
 896                         string_list_append(&cas_options, strbuf_detach(&cas, NULL));
 897                 }
 898         }
 899         if (buf.len == 0) {
 900                 string_list_clear(&cas_options, 0);
 901                 return 0;
 902         }
 903
 904         for_each_string_list_item(cas_option, &cas_options)
 905                 set_helper_option(transport, "cas", cas_option->string);
 906         set_common_push_options(transport, data->name, flags);
 907
 908         strbuf_addch(&buf, '\n');
 909         sendline(data, &buf);
 910         strbuf_release(&buf);
 911
 912         return push_update_refs_status(data, remote_refs, flags);
 913 }
 914
 915 static int push_refs_with_export(struct transport *transport,
 916                 struct ref *remote_refs, int flags)
 917 {
 918         struct ref *ref;
 919         struct child_process *helper, exporter;
 920         struct helper_data *data = transport->data;
 921         struct string_list revlist_args = STRING_LIST_INIT_DUP;
 922         struct strbuf buf = STRBUF_INIT;
 923
 924         if (!data->refspecs)
 925                 die("remote-helper doesn't support push; refspec needed");
 926
 927         set_common_push_options(transport, data->name, flags);
 928         if (flags & TRANSPORT_PUSH_FORCE) {
 929                 if (set_helper_option(transport, "force", "true") != 0)
 930                         warning("helper %s does not support 'force'", data->name);
 931         }
 932
 933         helper = get_helper(transport);
 934
 935         write_constant(helper->in, "export\n");
 936
 937         for (ref = remote_refs; ref; ref = ref->next) {
 938                 char *private;
 939                 struct object_id oid;
 940
 941                 private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
 942                 if (private && !get_sha1(private, oid.hash)) {
 943                         strbuf_addf(&buf, "^%s", private);
 944                         string_list_append(&revlist_args, strbuf_detach(&buf, NULL));
 945                         oidcpy(&ref->old_oid, &oid);
 946                 }
 947                 free(private);
 948
 949                 if (ref->peer_ref) {
 950                         if (strcmp(ref->name, ref->peer_ref->name)) {
 951                                 if (!ref->deletion) {
 952                                         const char *name;
 953                                         int flag;
 954
 955                                         /* Follow symbolic refs (mainly for HEAD). */
 956                                         name = resolve_ref_unsafe(
 957                                                  ref->peer_ref->name,
 958                                                  RESOLVE_REF_READING,
 959                                                  oid.hash, &flag);
 960                                         if (!name || !(flag & REF_ISSYMREF))
 961                                                 name = ref->peer_ref->name;
 962
 963                                         strbuf_addf(&buf, "%s:%s", name, ref->name);
 964                                 } else
 965                                         strbuf_addf(&buf, ":%s", ref->name);
 966
 967                                 string_list_append(&revlist_args, "--refspec");
 968                                 string_list_append(&revlist_args, buf.buf);
 969                                 strbuf_release(&buf);
 970                         }
 971                         if (!ref->deletion)
 972                                 string_list_append(&revlist_args, ref->peer_ref->name);
 973                 }
 974         }
 975
 976         if (get_exporter(transport, &exporter, &revlist_args))
 977                 die("Couldn't run fast-export");
 978
 979         string_list_clear(&revlist_args, 1);
 980
 981         if (finish_command(&exporter))
 982                 die("Error while running fast-export");
 983         if (push_update_refs_status(data, remote_refs, flags))
 984                 return 1;
 985
 986         if (data->export_marks) {
 987                 strbuf_addf(&buf, "%s.tmp", data->export_marks);
 988                 rename(buf.buf, data->export_marks);
 989                 strbuf_release(&buf);
 990         }
 991
 992         return 0;
 993 }
 994
 995 static int push_refs(struct transport *transport,
 996                 struct ref *remote_refs, int flags)
 997 {
 998         struct helper_data *data = transport->data;
 999
1000         if (process_connect(transport, 1)) {
1001                 do_take_over(transport);
1002                 return transport->push_refs(transport, remote_refs, flags);
1003         }
1004
1005         if (!remote_refs) {
1006                 fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
1007                         "Perhaps you should specify a branch such as 'master'.\n");
1008                 return 0;
1009         }
1010
1011         if (data->push)
1012                 return push_refs_with_push(transport, remote_refs, flags);
1013
1014         if (data->export)
1015                 return push_refs_with_export(transport, remote_refs, flags);
1016
1017         return -1;
1018 }
1019
1020
1021 static int has_attribute(const char *attrs, const char *attr) {
1022         int len;
1023         if (!attrs)
1024                 return 0;
1025
1026         len = strlen(attr);
1027         for (;;) {
1028                 const char *space = strchrnul(attrs, ' ');
1029                 if (len == space - attrs && !strncmp(attrs, attr, len))
1030                         return 1;
1031                 if (!*space)
1032                         return 0;
1033                 attrs = space + 1;
1034         }
1035 }
1036
1037 static struct ref *get_refs_list(struct transport *transport, int for_push)
1038 {
1039         struct helper_data *data = transport->data;
1040         struct child_process *helper;
1041         struct ref *ret = NULL;
1042         struct ref **tail = &ret;
1043         struct ref *posn;
1044         struct strbuf buf = STRBUF_INIT;
1045
1046         helper = get_helper(transport);
1047
1048         if (process_connect(transport, for_push)) {
1049                 do_take_over(transport);
1050                 return transport->get_refs_list(transport, for_push);
1051         }
1052
1053         if (data->push && for_push)
1054                 write_str_in_full(helper->in, "list for-push\n");
1055         else
1056                 write_str_in_full(helper->in, "list\n");
1057
1058         while (1) {
1059                 char *eov, *eon;
1060                 if (recvline(data, &buf))
1061                         exit(128);
1062
1063                 if (!*buf.buf)
1064                         break;
1065
1066                 eov = strchr(buf.buf, ' ');
1067                 if (!eov)
1068                         die("Malformed response in ref list: %s", buf.buf);
1069                 eon = strchr(eov + 1, ' ');
1070                 *eov = '\0';
1071                 if (eon)
1072                         *eon = '\0';
1073                 *tail = alloc_ref(eov + 1);
1074                 if (buf.buf[0] == '@')
1075                         (*tail)->symref = xstrdup(buf.buf + 1);
1076                 else if (buf.buf[0] != '?')
1077                         get_oid_hex(buf.buf, &(*tail)->old_oid);
1078                 if (eon) {
1079                         if (has_attribute(eon + 1, "unchanged")) {
1080                                 (*tail)->status |= REF_STATUS_UPTODATE;
1081                                 if (read_ref((*tail)->name,
1082                                              (*tail)->old_oid.hash) < 0)
1083                                         die(_("Could not read ref %s"),
1084                                             (*tail)->name);
1085                         }
1086                 }
1087                 tail = &((*tail)->next);
1088         }
1089         if (debug)
1090                 fprintf(stderr, "Debug: Read ref listing.\n");
1091         strbuf_release(&buf);
1092
1093         for (posn = ret; posn; posn = posn->next)
1094                 resolve_remote_symref(posn, ret);
1095
1096         return ret;
1097 }
1098
1099 int transport_helper_init(struct transport *transport, const char *name)
1100 {
1101         struct helper_data *data = xcalloc(1, sizeof(*data));
1102         data->name = name;
1103
1104         transport_check_allowed(name);
1105
1106         if (getenv("GIT_TRANSPORT_HELPER_DEBUG"))
1107                 debug = 1;
1108
1109         transport->data = data;
1110         transport->set_option = set_helper_option;
1111         transport->get_refs_list = get_refs_list;
1112         transport->fetch = fetch;
1113         transport->push_refs = push_refs;
1114         transport->disconnect = release_helper;
1115         transport->connect = connect_helper;
1116         transport->smart_options = &(data->transport_options);
1117         return 0;
1118 }
1119
1120 /*
1121  * Linux pipes can buffer 65536 bytes at once (and most platforms can
1122  * buffer less), so attempt reads and writes with up to that size.
1123  */
1124 #define BUFFERSIZE 65536
1125 /* This should be enough to hold debugging message. */
1126 #define PBUFFERSIZE 8192
1127
1128 /* Print bidirectional transfer loop debug message. */
1129 __attribute__((format (printf, 1, 2)))
1130 static void transfer_debug(const char *fmt, ...)
1131 {
1132         va_list args;
1133         char msgbuf[PBUFFERSIZE];
1134         static int debug_enabled = -1;
1135
1136         if (debug_enabled < 0)
1137                 debug_enabled = getenv("GIT_TRANSLOOP_DEBUG") ? 1 : 0;
1138         if (!debug_enabled)
1139                 return;
1140
1141         va_start(args, fmt);
1142         vsnprintf(msgbuf, PBUFFERSIZE, fmt, args);
1143         va_end(args);
1144         fprintf(stderr, "Transfer loop debugging: %s\n", msgbuf);
1145 }
1146
1147 /* Stream state: More data may be coming in this direction. */
1148 #define SSTATE_TRANSFERRING 0
1149 /*
1150  * Stream state: No more data coming in this direction, flushing rest of
1151  * data.
1152  */
1153 #define SSTATE_FLUSHING 1
1154 /* Stream state: Transfer in this direction finished. */
1155 #define SSTATE_FINISHED 2
1156
1157 #define STATE_NEEDS_READING(state) ((state) <= SSTATE_TRANSFERRING)
1158 #define STATE_NEEDS_WRITING(state) ((state) <= SSTATE_FLUSHING)
1159 #define STATE_NEEDS_CLOSING(state) ((state) == SSTATE_FLUSHING)
1160
1161 /* Unidirectional transfer. */
1162 struct unidirectional_transfer {
1163         /* Source */
1164         int src;
1165         /* Destination */
1166         int dest;
1167         /* Is source socket? */
1168         int src_is_sock;
1169         /* Is destination socket? */
1170         int dest_is_sock;
1171         /* Transfer state (TRANSFERRING/FLUSHING/FINISHED) */
1172         int state;
1173         /* Buffer. */
1174         char buf[BUFFERSIZE];
1175         /* Buffer used. */
1176         size_t bufuse;
1177         /* Name of source. */
1178         const char *src_name;
1179         /* Name of destination. */
1180         const char *dest_name;
1181 };
1182
1183 /* Closes the target (for writing) if transfer has finished. */
1184 static void udt_close_if_finished(struct unidirectional_transfer *t)
1185 {
1186         if (STATE_NEEDS_CLOSING(t->state) && !t->bufuse) {
1187                 t->state = SSTATE_FINISHED;
1188                 if (t->dest_is_sock)
1189                         shutdown(t->dest, SHUT_WR);
1190                 else
1191                         close(t->dest);
1192                 transfer_debug("Closed %s.", t->dest_name);
1193         }
1194 }
1195
1196 /*
1197  * Tries to read data from source into buffer. If buffer is full,
1198  * no data is read. Returns 0 on success, -1 on error.
1199  */
1200 static int udt_do_read(struct unidirectional_transfer *t)
1201 {
1202         ssize_t bytes;
1203
1204         if (t->bufuse == BUFFERSIZE)
1205                 return 0;       /* No space for more. */
1206
1207         transfer_debug("%s is readable", t->src_name);
1208         bytes = read(t->src, t->buf + t->bufuse, BUFFERSIZE - t->bufuse);
1209         if (bytes < 0 && errno != EWOULDBLOCK && errno != EAGAIN &&
1210                 errno != EINTR) {
1211                 error_errno("read(%s) failed", t->src_name);
1212                 return -1;
1213         } else if (bytes == 0) {
1214                 transfer_debug("%s EOF (with %i bytes in buffer)",
1215                         t->src_name, (int)t->bufuse);
1216                 t->state = SSTATE_FLUSHING;
1217         } else if (bytes > 0) {
1218                 t->bufuse += bytes;
1219                 transfer_debug("Read %i bytes from %s (buffer now at %i)",
1220                         (int)bytes, t->src_name, (int)t->bufuse);
1221         }
1222         return 0;
1223 }
1224
1225 /* Tries to write data from buffer into destination. If buffer is empty,
1226  * no data is written. Returns 0 on success, -1 on error.
1227  */
1228 static int udt_do_write(struct unidirectional_transfer *t)
1229 {
1230         ssize_t bytes;
1231
1232         if (t->bufuse == 0)
1233                 return 0;       /* Nothing to write. */
1234
1235         transfer_debug("%s is writable", t->dest_name);
1236         bytes = xwrite(t->dest, t->buf, t->bufuse);
1237         if (bytes < 0 && errno != EWOULDBLOCK) {
1238                 error_errno("write(%s) failed", t->dest_name);
1239                 return -1;
1240         } else if (bytes > 0) {
1241                 t->bufuse -= bytes;
1242                 if (t->bufuse)
1243                         memmove(t->buf, t->buf + bytes, t->bufuse);
1244                 transfer_debug("Wrote %i bytes to %s (buffer now at %i)",
1245                         (int)bytes, t->dest_name, (int)t->bufuse);
1246         }
1247         return 0;
1248 }
1249
1250
1251 /* State of bidirectional transfer loop. */
1252 struct bidirectional_transfer_state {
1253         /* Direction from program to git. */
1254         struct unidirectional_transfer ptg;
1255         /* Direction from git to program. */
1256         struct unidirectional_transfer gtp;
1257 };
1258
1259 static void *udt_copy_task_routine(void *udt)
1260 {
1261         struct unidirectional_transfer *t = (struct unidirectional_transfer *)udt;
1262         while (t->state != SSTATE_FINISHED) {
1263                 if (STATE_NEEDS_READING(t->state))
1264                         if (udt_do_read(t))
1265                                 return NULL;
1266                 if (STATE_NEEDS_WRITING(t->state))
1267                         if (udt_do_write(t))
1268                                 return NULL;
1269                 if (STATE_NEEDS_CLOSING(t->state))
1270                         udt_close_if_finished(t);
1271         }
1272         return udt;     /* Just some non-NULL value. */
1273 }
1274
1275 #ifndef NO_PTHREADS
1276
1277 /*
1278  * Join thread, with appropriate errors on failure. Name is name for the
1279  * thread (for error messages). Returns 0 on success, 1 on failure.
1280  */
1281 static int tloop_join(pthread_t thread, const char *name)
1282 {
1283         int err;
1284         void *tret;
1285         err = pthread_join(thread, &tret);
1286         if (!tret) {
1287                 error("%s thread failed", name);
1288                 return 1;
1289         }
1290         if (err) {
1291                 error("%s thread failed to join: %s", name, strerror(err));
1292                 return 1;
1293         }
1294         return 0;
1295 }
1296
1297 /*
1298  * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1299  * -1 on failure.
1300  */
1301 static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1302 {
1303         pthread_t gtp_thread;
1304         pthread_t ptg_thread;
1305         int err;
1306         int ret = 0;
1307         err = pthread_create(&gtp_thread, NULL, udt_copy_task_routine,
1308                 &s->gtp);
1309         if (err)
1310                 die("Can't start thread for copying data: %s", strerror(err));
1311         err = pthread_create(&ptg_thread, NULL, udt_copy_task_routine,
1312                 &s->ptg);
1313         if (err)
1314                 die("Can't start thread for copying data: %s", strerror(err));
1315
1316         ret |= tloop_join(gtp_thread, "Git to program copy");
1317         ret |= tloop_join(ptg_thread, "Program to git copy");
1318         return ret;
1319 }
1320 #else
1321
1322 /* Close the source and target (for writing) for transfer. */
1323 static void udt_kill_transfer(struct unidirectional_transfer *t)
1324 {
1325         t->state = SSTATE_FINISHED;
1326         /*
1327          * Socket read end left open isn't a disaster if nobody
1328          * attempts to read from it (mingw compat headers do not
1329          * have SHUT_RD)...
1330          *
1331          * We can't fully close the socket since otherwise gtp
1332          * task would first close the socket it sends data to
1333          * while closing the ptg file descriptors.
1334          */
1335         if (!t->src_is_sock)
1336                 close(t->src);
1337         if (t->dest_is_sock)
1338                 shutdown(t->dest, SHUT_WR);
1339         else
1340                 close(t->dest);
1341 }
1342
1343 /*
1344  * Join process, with appropriate errors on failure. Name is name for the
1345  * process (for error messages). Returns 0 on success, 1 on failure.
1346  */
1347 static int tloop_join(pid_t pid, const char *name)
1348 {
1349         int tret;
1350         if (waitpid(pid, &tret, 0) < 0) {
1351                 error_errno("%s process failed to wait", name);
1352                 return 1;
1353         }
1354         if (!WIFEXITED(tret) || WEXITSTATUS(tret)) {
1355                 error("%s process failed", name);
1356                 return 1;
1357         }
1358         return 0;
1359 }
1360
1361 /*
1362  * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1363  * -1 on failure.
1364  */
1365 static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1366 {
1367         pid_t pid1, pid2;
1368         int ret = 0;
1369
1370         /* Fork thread #1: git to program. */
1371         pid1 = fork();
1372         if (pid1 < 0)
1373                 die_errno("Can't start thread for copying data");
1374         else if (pid1 == 0) {
1375                 udt_kill_transfer(&s->ptg);
1376                 exit(udt_copy_task_routine(&s->gtp) ? 0 : 1);
1377         }
1378
1379         /* Fork thread #2: program to git. */
1380         pid2 = fork();
1381         if (pid2 < 0)
1382                 die_errno("Can't start thread for copying data");
1383         else if (pid2 == 0) {
1384                 udt_kill_transfer(&s->gtp);
1385                 exit(udt_copy_task_routine(&s->ptg) ? 0 : 1);
1386         }
1387
1388         /*
1389          * Close both streams in parent as to not interfere with
1390          * end of file detection and wait for both tasks to finish.
1391          */
1392         udt_kill_transfer(&s->gtp);
1393         udt_kill_transfer(&s->ptg);
1394         ret |= tloop_join(pid1, "Git to program copy");
1395         ret |= tloop_join(pid2, "Program to git copy");
1396         return ret;
1397 }
1398 #endif
1399
1400 /*
1401  * Copies data from stdin to output and from input to stdout simultaneously.
1402  * Additionally filtering through given filter. If filter is NULL, uses
1403  * identity filter.
1404  */
1405 int bidirectional_transfer_loop(int input, int output)
1406 {
1407         struct bidirectional_transfer_state state;
1408
1409         /* Fill the state fields. */
1410         state.ptg.src = input;
1411         state.ptg.dest = 1;
1412         state.ptg.src_is_sock = (input == output);
1413         state.ptg.dest_is_sock = 0;
1414         state.ptg.state = SSTATE_TRANSFERRING;
1415         state.ptg.bufuse = 0;
1416         state.ptg.src_name = "remote input";
1417         state.ptg.dest_name = "stdout";
1418
1419         state.gtp.src = 0;
1420         state.gtp.dest = output;
1421         state.gtp.src_is_sock = 0;
1422         state.gtp.dest_is_sock = (input == output);
1423         state.gtp.state = SSTATE_TRANSFERRING;
1424         state.gtp.bufuse = 0;
1425         state.gtp.src_name = "stdin";
1426         state.gtp.dest_name = "remote output";
1427
1428         return tloop_spawnwait_tasks(&state);
1429 }