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