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         argv_array_pushf(&helper->env_array, "%s=%s", GIT_DIR_ENVIRONMENT,
 128                          get_git_dir());
 129
 130         code = start_command(helper);
 131         if (code < 0 && errno == ENOENT)
 132                 die("Unable to find remote helper for '%s'", data->name);
 133         else if (code != 0)
 134                 exit(code);
 135
 136         data->helper = helper;
 137         data->no_disconnect_req = 0;
 138
 139         /*
 140          * Open the output as FILE* so strbuf_getline_*() family of
 141          * functions can be used.
 142          * Do this with duped fd because fclose() will close the fd,
 143          * and stuff like taking over will require the fd to remain.
 144          */
 145         duped = dup(helper->out);
 146         if (duped < 0)
 147                 die_errno("Can't dup helper output fd");
 148         data->out = xfdopen(duped, "r");
 149
 150         write_constant(helper->in, "capabilities\n");
 151
 152         while (1) {
 153                 const char *capname, *arg;
 154                 int mandatory = 0;
 155                 if (recvline(data, &buf))
 156                         exit(128);
 157
 158                 if (!*buf.buf)
 159                         break;
 160
 161                 if (*buf.buf == '*') {
 162                         capname = buf.buf + 1;
 163                         mandatory = 1;
 164                 } else
 165                         capname = buf.buf;
 166
 167                 if (debug)
 168                         fprintf(stderr, "Debug: Got cap %s\n", capname);
 169                 if (!strcmp(capname, "fetch"))
 170                         data->fetch = 1;
 171                 else if (!strcmp(capname, "option"))
 172                         data->option = 1;
 173                 else if (!strcmp(capname, "push"))
 174                         data->push = 1;
 175                 else if (!strcmp(capname, "import"))
 176                         data->import = 1;
 177                 else if (!strcmp(capname, "bidi-import"))
 178                         data->bidi_import = 1;
 179                 else if (!strcmp(capname, "export"))
 180                         data->export = 1;
 181                 else if (!strcmp(capname, "check-connectivity"))
 182                         data->check_connectivity = 1;
 183                 else if (!data->refspecs && skip_prefix(capname, "refspec ", &arg)) {
 184                         ALLOC_GROW(refspecs,
 185                                    refspec_nr + 1,
 186                                    refspec_alloc);
 187                         refspecs[refspec_nr++] = xstrdup(arg);
 188                 } else if (!strcmp(capname, "connect")) {
 189                         data->connect = 1;
 190                 } else if (!strcmp(capname, "signed-tags")) {
 191                         data->signed_tags = 1;
 192                 } else if (skip_prefix(capname, "export-marks ", &arg)) {
 193                         data->export_marks = xstrdup(arg);
 194                 } else if (skip_prefix(capname, "import-marks ", &arg)) {
 195                         data->import_marks = xstrdup(arg);
 196                 } else if (starts_with(capname, "no-private-update")) {
 197                         data->no_private_update = 1;
 198                 } else if (mandatory) {
 199                         die("Unknown mandatory capability %s. This remote "
 200                             "helper probably needs newer version of Git.",
 201                             capname);
 202                 }
 203         }
 204         if (refspecs) {
 205                 int i;
 206                 data->refspec_nr = refspec_nr;
 207                 data->refspecs = parse_fetch_refspec(refspec_nr, refspecs);
 208                 for (i = 0; i < refspec_nr; i++)
 209                         free((char *)refspecs[i]);
 210                 free(refspecs);
 211         } else if (data->import || data->bidi_import || data->export) {
 212                 warning("This remote helper should implement refspec capability.");
 213         }
 214         strbuf_release(&buf);
 215         if (debug)
 216                 fprintf(stderr, "Debug: Capabilities complete.\n");
 217         standard_options(transport);
 218         return data->helper;
 219 }
 220
 221 static int disconnect_helper(struct transport *transport)
 222 {
 223         struct helper_data *data = transport->data;
 224         int res = 0;
 225
 226         if (data->helper) {
 227                 if (debug)
 228                         fprintf(stderr, "Debug: Disconnecting.\n");
 229                 if (!data->no_disconnect_req) {
 230                         /*
 231                          * Ignore write errors; there's nothing we can do,
 232                          * since we're about to close the pipe anyway. And the
 233                          * most likely error is EPIPE due to the helper dying
 234                          * to report an error itself.
 235                          */
 236                         sigchain_push(SIGPIPE, SIG_IGN);
 237                         xwrite(data->helper->in, "\n", 1);
 238                         sigchain_pop(SIGPIPE);
 239                 }
 240                 close(data->helper->in);
 241                 close(data->helper->out);
 242                 fclose(data->out);
 243                 res = finish_command(data->helper);
 244                 free(data->helper);
 245                 data->helper = NULL;
 246         }
 247         return res;
 248 }
 249
 250 static const char *unsupported_options[] = {
 251         TRANS_OPT_UPLOADPACK,
 252         TRANS_OPT_RECEIVEPACK,
 253         TRANS_OPT_THIN,
 254         TRANS_OPT_KEEP
 255         };
 256
 257 static const char *boolean_options[] = {
 258         TRANS_OPT_THIN,
 259         TRANS_OPT_KEEP,
 260         TRANS_OPT_FOLLOWTAGS,
 261         TRANS_OPT_DEEPEN_RELATIVE
 262         };
 263
 264 static int strbuf_set_helper_option(struct helper_data *data,
 265                                     struct strbuf *buf)
 266 {
 267         int ret;
 268
 269         sendline(data, buf);
 270         if (recvline(data, buf))
 271                 exit(128);
 272
 273         if (!strcmp(buf->buf, "ok"))
 274                 ret = 0;
 275         else if (starts_with(buf->buf, "error"))
 276                 ret = -1;
 277         else if (!strcmp(buf->buf, "unsupported"))
 278                 ret = 1;
 279         else {
 280                 warning("%s unexpectedly said: '%s'", data->name, buf->buf);
 281                 ret = 1;
 282         }
 283         return ret;
 284 }
 285
 286 static int string_list_set_helper_option(struct helper_data *data,
 287                                          const char *name,
 288                                          struct string_list *list)
 289 {
 290         struct strbuf buf = STRBUF_INIT;
 291         int i, ret = 0;
 292
 293         for (i = 0; i < list->nr; i++) {
 294                 strbuf_addf(&buf, "option %s ", name);
 295                 quote_c_style(list->items[i].string, &buf, NULL, 0);
 296                 strbuf_addch(&buf, '\n');
 297
 298                 if ((ret = strbuf_set_helper_option(data, &buf)))
 299                         break;
 300                 strbuf_reset(&buf);
 301         }
 302         strbuf_release(&buf);
 303         return ret;
 304 }
 305
 306 static int set_helper_option(struct transport *transport,
 307                           const char *name, const char *value)
 308 {
 309         struct helper_data *data = transport->data;
 310         struct strbuf buf = STRBUF_INIT;
 311         int i, ret, is_bool = 0;
 312
 313         get_helper(transport);
 314
 315         if (!data->option)
 316                 return 1;
 317
 318         if (!strcmp(name, "deepen-not"))
 319                 return string_list_set_helper_option(data, name,
 320                                                      (struct string_list *)value);
 321
 322         for (i = 0; i < ARRAY_SIZE(unsupported_options); i++) {
 323                 if (!strcmp(name, unsupported_options[i]))
 324                         return 1;
 325         }
 326
 327         for (i = 0; i < ARRAY_SIZE(boolean_options); i++) {
 328                 if (!strcmp(name, boolean_options[i])) {
 329                         is_bool = 1;
 330                         break;
 331                 }
 332         }
 333
 334         strbuf_addf(&buf, "option %s ", name);
 335         if (is_bool)
 336                 strbuf_addstr(&buf, value ? "true" : "false");
 337         else
 338                 quote_c_style(value, &buf, NULL, 0);
 339         strbuf_addch(&buf, '\n');
 340
 341         ret = strbuf_set_helper_option(data, &buf);
 342         strbuf_release(&buf);
 343         return ret;
 344 }
 345
 346 static void standard_options(struct transport *t)
 347 {
 348         char buf[16];
 349         int n;
 350         int v = t->verbose;
 351
 352         set_helper_option(t, "progress", t->progress ? "true" : "false");
 353
 354         n = snprintf(buf, sizeof(buf), "%d", v + 1);
 355         if (n >= sizeof(buf))
 356                 die("impossibly large verbosity value");
 357         set_helper_option(t, "verbosity", buf);
 358
 359         switch (t->family) {
 360         case TRANSPORT_FAMILY_ALL:
 361                 /*
 362                  * this is already the default,
 363                  * do not break old remote helpers by setting "all" here
 364                  */
 365                 break;
 366         case TRANSPORT_FAMILY_IPV4:
 367                 set_helper_option(t, "family", "ipv4");
 368                 break;
 369         case TRANSPORT_FAMILY_IPV6:
 370                 set_helper_option(t, "family", "ipv6");
 371                 break;
 372         }
 373 }
 374
 375 static int release_helper(struct transport *transport)
 376 {
 377         int res = 0;
 378         struct helper_data *data = transport->data;
 379         free_refspec(data->refspec_nr, data->refspecs);
 380         data->refspecs = NULL;
 381         res = disconnect_helper(transport);
 382         free(transport->data);
 383         return res;
 384 }
 385
 386 static int fetch_with_fetch(struct transport *transport,
 387                             int nr_heads, struct ref **to_fetch)
 388 {
 389         struct helper_data *data = transport->data;
 390         int i;
 391         struct strbuf buf = STRBUF_INIT;
 392
 393         for (i = 0; i < nr_heads; i++) {
 394                 const struct ref *posn = to_fetch[i];
 395                 if (posn->status & REF_STATUS_UPTODATE)
 396                         continue;
 397
 398                 strbuf_addf(&buf, "fetch %s %s\n",
 399                             oid_to_hex(&posn->old_oid),
 400                             posn->symref ? posn->symref : posn->name);
 401         }
 402
 403         strbuf_addch(&buf, '\n');
 404         sendline(data, &buf);
 405
 406         while (1) {
 407                 if (recvline(data, &buf))
 408                         exit(128);
 409
 410                 if (starts_with(buf.buf, "lock ")) {
 411                         const char *name = buf.buf + 5;
 412                         if (transport->pack_lockfile)
 413                                 warning("%s also locked %s", data->name, name);
 414                         else
 415                                 transport->pack_lockfile = xstrdup(name);
 416                 }
 417                 else if (data->check_connectivity &&
 418                          data->transport_options.check_self_contained_and_connected &&
 419                          !strcmp(buf.buf, "connectivity-ok"))
 420                         data->transport_options.self_contained_and_connected = 1;
 421                 else if (!buf.len)
 422                         break;
 423                 else
 424                         warning("%s unexpectedly said: '%s'", data->name, buf.buf);
 425         }
 426         strbuf_release(&buf);
 427         return 0;
 428 }
 429
 430 static int get_importer(struct transport *transport, struct child_process *fastimport)
 431 {
 432         struct child_process *helper = get_helper(transport);
 433         struct helper_data *data = transport->data;
 434         int cat_blob_fd, code;
 435         child_process_init(fastimport);
 436         fastimport->in = helper->out;
 437         argv_array_push(&fastimport->args, "fast-import");
 438         argv_array_push(&fastimport->args, debug ? "--stats" : "--quiet");
 439
 440         if (data->bidi_import) {
 441                 cat_blob_fd = xdup(helper->in);
 442                 argv_array_pushf(&fastimport->args, "--cat-blob-fd=%d", cat_blob_fd);
 443         }
 444         fastimport->git_cmd = 1;
 445
 446         code = start_command(fastimport);
 447         return code;
 448 }
 449
 450 static int get_exporter(struct transport *transport,
 451                         struct child_process *fastexport,
 452                         struct string_list *revlist_args)
 453 {
 454         struct helper_data *data = transport->data;
 455         struct child_process *helper = get_helper(transport);
 456         int i;
 457
 458         child_process_init(fastexport);
 459
 460         /* we need to duplicate helper->in because we want to use it after
 461          * fastexport is done with it. */
 462         fastexport->out = dup(helper->in);
 463         argv_array_push(&fastexport->args, "fast-export");
 464         argv_array_push(&fastexport->args, "--use-done-feature");
 465         argv_array_push(&fastexport->args, data->signed_tags ?
 466                 "--signed-tags=verbatim" : "--signed-tags=warn-strip");
 467         if (data->export_marks)
 468                 argv_array_pushf(&fastexport->args, "--export-marks=%s.tmp", data->export_marks);
 469         if (data->import_marks)
 470                 argv_array_pushf(&fastexport->args, "--import-marks=%s", data->import_marks);
 471
 472         for (i = 0; i < revlist_args->nr; i++)
 473                 argv_array_push(&fastexport->args, revlist_args->items[i].string);
 474
 475         fastexport->git_cmd = 1;
 476         return start_command(fastexport);
 477 }
 478
 479 static int fetch_with_import(struct transport *transport,
 480                              int nr_heads, struct ref **to_fetch)
 481 {
 482         struct child_process fastimport;
 483         struct helper_data *data = transport->data;
 484         int i;
 485         struct ref *posn;
 486         struct strbuf buf = STRBUF_INIT;
 487
 488         get_helper(transport);
 489
 490         if (get_importer(transport, &fastimport))
 491                 die("Couldn't run fast-import");
 492
 493         for (i = 0; i < nr_heads; i++) {
 494                 posn = to_fetch[i];
 495                 if (posn->status & REF_STATUS_UPTODATE)
 496                         continue;
 497
 498                 strbuf_addf(&buf, "import %s\n",
 499                             posn->symref ? posn->symref : posn->name);
 500                 sendline(data, &buf);
 501                 strbuf_reset(&buf);
 502         }
 503
 504         write_constant(data->helper->in, "\n");
 505         /*
 506          * remote-helpers that advertise the bidi-import capability are required to
 507          * buffer the complete batch of import commands until this newline before
 508          * sending data to fast-import.
 509          * These helpers read back data from fast-import on their stdin, which could
 510          * be mixed with import commands, otherwise.
 511          */
 512
 513         if (finish_command(&fastimport))
 514                 die("Error while running fast-import");
 515
 516         /*
 517          * The fast-import stream of a remote helper that advertises
 518          * the "refspec" capability writes to the refs named after the
 519          * right hand side of the first refspec matching each ref we
 520          * were fetching.
 521          *
 522          * (If no "refspec" capability was specified, for historical
 523          * reasons we default to the equivalent of *:*.)
 524          *
 525          * Store the result in to_fetch[i].old_sha1.  Callers such
 526          * as "git fetch" can use the value to write feedback to the
 527          * terminal, populate FETCH_HEAD, and determine what new value
 528          * should be written to peer_ref if the update is a
 529          * fast-forward or this is a forced update.
 530          */
 531         for (i = 0; i < nr_heads; i++) {
 532                 char *private, *name;
 533                 posn = to_fetch[i];
 534                 if (posn->status & REF_STATUS_UPTODATE)
 535                         continue;
 536                 name = posn->symref ? posn->symref : posn->name;
 537                 if (data->refspecs)
 538                         private = apply_refspecs(data->refspecs, data->refspec_nr, name);
 539                 else
 540                         private = xstrdup(name);
 541                 if (private) {
 542                         if (read_ref(private, posn->old_oid.hash) < 0)
 543                                 die("Could not read ref %s", private);
 544                         free(private);
 545                 }
 546         }
 547         strbuf_release(&buf);
 548         return 0;
 549 }
 550
 551 static int process_connect_service(struct transport *transport,
 552                                    const char *name, const char *exec)
 553 {
 554         struct helper_data *data = transport->data;
 555         struct strbuf cmdbuf = STRBUF_INIT;
 556         struct child_process *helper;
 557         int r, duped, ret = 0;
 558         FILE *input;
 559
 560         helper = get_helper(transport);
 561
 562         /*
 563          * Yes, dup the pipe another time, as we need unbuffered version
 564          * of input pipe as FILE*. fclose() closes the underlying fd and
 565          * stream buffering only can be changed before first I/O operation
 566          * on it.
 567          */
 568         duped = dup(helper->out);
 569         if (duped < 0)
 570                 die_errno("Can't dup helper output fd");
 571         input = xfdopen(duped, "r");
 572         setvbuf(input, NULL, _IONBF, 0);
 573
 574         /*
 575          * Handle --upload-pack and friends. This is fire and forget...
 576          * just warn if it fails.
 577          */
 578         if (strcmp(name, exec)) {
 579                 r = set_helper_option(transport, "servpath", exec);
 580                 if (r > 0)
 581                         warning("Setting remote service path not supported by protocol.");
 582                 else if (r < 0)
 583                         warning("Invalid remote service path.");
 584         }
 585
 586         if (data->connect)
 587                 strbuf_addf(&cmdbuf, "connect %s\n", name);
 588         else
 589                 goto exit;
 590
 591         sendline(data, &cmdbuf);
 592         if (recvline_fh(input, &cmdbuf, name))
 593                 exit(128);
 594
 595         if (!strcmp(cmdbuf.buf, "")) {
 596                 data->no_disconnect_req = 1;
 597                 if (debug)
 598                         fprintf(stderr, "Debug: Smart transport connection "
 599                                 "ready.\n");
 600                 ret = 1;
 601         } else if (!strcmp(cmdbuf.buf, "fallback")) {
 602                 if (debug)
 603                         fprintf(stderr, "Debug: Falling back to dumb "
 604                                 "transport.\n");
 605         } else
 606                 die("Unknown response to connect: %s",
 607                         cmdbuf.buf);
 608
 609 exit:
 610         fclose(input);
 611         return ret;
 612 }
 613
 614 static int process_connect(struct transport *transport,
 615                                      int for_push)
 616 {
 617         struct helper_data *data = transport->data;
 618         const char *name;
 619         const char *exec;
 620
 621         name = for_push ? "git-receive-pack" : "git-upload-pack";
 622         if (for_push)
 623                 exec = data->transport_options.receivepack;
 624         else
 625                 exec = data->transport_options.uploadpack;
 626
 627         return process_connect_service(transport, name, exec);
 628 }
 629
 630 static int connect_helper(struct transport *transport, const char *name,
 631                    const char *exec, int fd[2])
 632 {
 633         struct helper_data *data = transport->data;
 634
 635         /* Get_helper so connect is inited. */
 636         get_helper(transport);
 637         if (!data->connect)
 638                 die("Operation not supported by protocol.");
 639
 640         if (!process_connect_service(transport, name, exec))
 641                 die("Can't connect to subservice %s.", name);
 642
 643         fd[0] = data->helper->out;
 644         fd[1] = data->helper->in;
 645         return 0;
 646 }
 647
 648 static int fetch(struct transport *transport,
 649                  int nr_heads, struct ref **to_fetch)
 650 {
 651         struct helper_data *data = transport->data;
 652         int i, count;
 653
 654         if (process_connect(transport, 0)) {
 655                 do_take_over(transport);
 656                 return transport->fetch(transport, nr_heads, to_fetch);
 657         }
 658
 659         count = 0;
 660         for (i = 0; i < nr_heads; i++)
 661                 if (!(to_fetch[i]->status & REF_STATUS_UPTODATE))
 662                         count++;
 663
 664         if (!count)
 665                 return 0;
 666
 667         if (data->check_connectivity &&
 668             data->transport_options.check_self_contained_and_connected)
 669                 set_helper_option(transport, "check-connectivity", "true");
 670
 671         if (transport->cloning)
 672                 set_helper_option(transport, "cloning", "true");
 673
 674         if (data->transport_options.update_shallow)
 675                 set_helper_option(transport, "update-shallow", "true");
 676
 677         if (data->fetch)
 678                 return fetch_with_fetch(transport, nr_heads, to_fetch);
 679
 680         if (data->import)
 681                 return fetch_with_import(transport, nr_heads, to_fetch);
 682
 683         return -1;
 684 }
 685
 686 static int push_update_ref_status(struct strbuf *buf,
 687                                    struct ref **ref,
 688                                    struct ref *remote_refs)
 689 {
 690         char *refname, *msg;
 691         int status, forced = 0;
 692
 693         if (starts_with(buf->buf, "ok ")) {
 694                 status = REF_STATUS_OK;
 695                 refname = buf->buf + 3;
 696         } else if (starts_with(buf->buf, "error ")) {
 697                 status = REF_STATUS_REMOTE_REJECT;
 698                 refname = buf->buf + 6;
 699         } else
 700                 die("expected ok/error, helper said '%s'", buf->buf);
 701
 702         msg = strchr(refname, ' ');
 703         if (msg) {
 704                 struct strbuf msg_buf = STRBUF_INIT;
 705                 const char *end;
 706
 707                 *msg++ = '\0';
 708                 if (!unquote_c_style(&msg_buf, msg, &end))
 709                         msg = strbuf_detach(&msg_buf, NULL);
 710                 else
 711                         msg = xstrdup(msg);
 712                 strbuf_release(&msg_buf);
 713
 714                 if (!strcmp(msg, "no match")) {
 715                         status = REF_STATUS_NONE;
 716                         free(msg);
 717                         msg = NULL;
 718                 }
 719                 else if (!strcmp(msg, "up to date")) {
 720                         status = REF_STATUS_UPTODATE;
 721                         free(msg);
 722                         msg = NULL;
 723                 }
 724                 else if (!strcmp(msg, "non-fast forward")) {
 725                         status = REF_STATUS_REJECT_NONFASTFORWARD;
 726                         free(msg);
 727                         msg = NULL;
 728                 }
 729                 else if (!strcmp(msg, "already exists")) {
 730                         status = REF_STATUS_REJECT_ALREADY_EXISTS;
 731                         free(msg);
 732                         msg = NULL;
 733                 }
 734                 else if (!strcmp(msg, "fetch first")) {
 735                         status = REF_STATUS_REJECT_FETCH_FIRST;
 736                         free(msg);
 737                         msg = NULL;
 738                 }
 739                 else if (!strcmp(msg, "needs force")) {
 740                         status = REF_STATUS_REJECT_NEEDS_FORCE;
 741                         free(msg);
 742                         msg = NULL;
 743                 }
 744                 else if (!strcmp(msg, "stale info")) {
 745                         status = REF_STATUS_REJECT_STALE;
 746                         free(msg);
 747                         msg = NULL;
 748                 }
 749                 else if (!strcmp(msg, "forced update")) {
 750                         forced = 1;
 751                         free(msg);
 752                         msg = NULL;
 753                 }
 754         }
 755
 756         if (*ref)
 757                 *ref = find_ref_by_name(*ref, refname);
 758         if (!*ref)
 759                 *ref = find_ref_by_name(remote_refs, refname);
 760         if (!*ref) {
 761                 warning("helper reported unexpected status of %s", refname);
 762                 return 1;
 763         }
 764
 765         if ((*ref)->status != REF_STATUS_NONE) {
 766                 /*
 767                  * Earlier, the ref was marked not to be pushed, so ignore the ref
 768                  * status reported by the remote helper if the latter is 'no match'.
 769                  */
 770                 if (status == REF_STATUS_NONE)
 771                         return 1;
 772         }
 773
 774         (*ref)->status = status;
 775         (*ref)->forced_update |= forced;
 776         (*ref)->remote_status = msg;
 777         return !(status == REF_STATUS_OK);
 778 }
 779
 780 static int push_update_refs_status(struct helper_data *data,
 781                                     struct ref *remote_refs,
 782                                     int flags)
 783 {
 784         struct strbuf buf = STRBUF_INIT;
 785         struct ref *ref = remote_refs;
 786         int ret = 0;
 787
 788         for (;;) {
 789                 char *private;
 790
 791                 if (recvline(data, &buf)) {
 792                         ret = 1;
 793                         break;
 794                 }
 795
 796                 if (!buf.len)
 797                         break;
 798
 799                 if (push_update_ref_status(&buf, &ref, remote_refs))
 800                         continue;
 801
 802                 if (flags & TRANSPORT_PUSH_DRY_RUN || !data->refspecs || data->no_private_update)
 803                         continue;
 804
 805                 /* propagate back the update to the remote namespace */
 806                 private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
 807                 if (!private)
 808                         continue;
 809                 update_ref("update by helper", private, ref->new_oid.hash, NULL, 0, 0);
 810                 free(private);
 811         }
 812         strbuf_release(&buf);
 813         return ret;
 814 }
 815
 816 static void set_common_push_options(struct transport *transport,
 817                                    const char *name, int flags)
 818 {
 819         if (flags & TRANSPORT_PUSH_DRY_RUN) {
 820                 if (set_helper_option(transport, "dry-run", "true") != 0)
 821                         die("helper %s does not support dry-run", name);
 822         } else if (flags & TRANSPORT_PUSH_CERT_ALWAYS) {
 823                 if (set_helper_option(transport, TRANS_OPT_PUSH_CERT, "true") != 0)
 824                         die("helper %s does not support --signed", name);
 825         } else if (flags & TRANSPORT_PUSH_CERT_IF_ASKED) {
 826                 if (set_helper_option(transport, TRANS_OPT_PUSH_CERT, "if-asked") != 0)
 827                         die("helper %s does not support --signed=if-asked", name);
 828         }
 829 }
 830
 831 static int push_refs_with_push(struct transport *transport,
 832                                struct ref *remote_refs, int flags)
 833 {
 834         int force_all = flags & TRANSPORT_PUSH_FORCE;
 835         int mirror = flags & TRANSPORT_PUSH_MIRROR;
 836         struct helper_data *data = transport->data;
 837         struct strbuf buf = STRBUF_INIT;
 838         struct ref *ref;
 839         struct string_list cas_options = STRING_LIST_INIT_DUP;
 840         struct string_list_item *cas_option;
 841
 842         get_helper(transport);
 843         if (!data->push)
 844                 return 1;
 845
 846         for (ref = remote_refs; ref; ref = ref->next) {
 847                 if (!ref->peer_ref && !mirror)
 848                         continue;
 849
 850                 /* Check for statuses set by set_ref_status_for_push() */
 851                 switch (ref->status) {
 852                 case REF_STATUS_REJECT_NONFASTFORWARD:
 853                 case REF_STATUS_REJECT_STALE:
 854                 case REF_STATUS_REJECT_ALREADY_EXISTS:
 855                 case REF_STATUS_UPTODATE:
 856                         continue;
 857                 default:
 858                         ; /* do nothing */
 859                 }
 860
 861                 if (force_all)
 862                         ref->force = 1;
 863
 864                 strbuf_addstr(&buf, "push ");
 865                 if (!ref->deletion) {
 866                         if (ref->force)
 867                                 strbuf_addch(&buf, '+');
 868                         if (ref->peer_ref)
 869                                 strbuf_addstr(&buf, ref->peer_ref->name);
 870                         else
 871                                 strbuf_addstr(&buf, oid_to_hex(&ref->new_oid));
 872                 }
 873                 strbuf_addch(&buf, ':');
 874                 strbuf_addstr(&buf, ref->name);
 875                 strbuf_addch(&buf, '\n');
 876
 877                 /*
 878                  * The "--force-with-lease" options without explicit
 879                  * values to expect have already been expanded into
 880                  * the ref->old_oid_expect[] field; we can ignore
 881                  * transport->smart_options->cas altogether and instead
 882                  * can enumerate them from the refs.
 883                  */
 884                 if (ref->expect_old_sha1) {
 885                         struct strbuf cas = STRBUF_INIT;
 886                         strbuf_addf(&cas, "%s:%s",
 887                                     ref->name, oid_to_hex(&ref->old_oid_expect));
 888                         string_list_append(&cas_options, strbuf_detach(&cas, NULL));
 889                 }
 890         }
 891         if (buf.len == 0) {
 892                 string_list_clear(&cas_options, 0);
 893                 return 0;
 894         }
 895
 896         for_each_string_list_item(cas_option, &cas_options)
 897                 set_helper_option(transport, "cas", cas_option->string);
 898         set_common_push_options(transport, data->name, flags);
 899
 900         strbuf_addch(&buf, '\n');
 901         sendline(data, &buf);
 902         strbuf_release(&buf);
 903
 904         return push_update_refs_status(data, remote_refs, flags);
 905 }
 906
 907 static int push_refs_with_export(struct transport *transport,
 908                 struct ref *remote_refs, int flags)
 909 {
 910         struct ref *ref;
 911         struct child_process *helper, exporter;
 912         struct helper_data *data = transport->data;
 913         struct string_list revlist_args = STRING_LIST_INIT_DUP;
 914         struct strbuf buf = STRBUF_INIT;
 915
 916         if (!data->refspecs)
 917                 die("remote-helper doesn't support push; refspec needed");
 918
 919         set_common_push_options(transport, data->name, flags);
 920         if (flags & TRANSPORT_PUSH_FORCE) {
 921                 if (set_helper_option(transport, "force", "true") != 0)
 922                         warning("helper %s does not support 'force'", data->name);
 923         }
 924
 925         helper = get_helper(transport);
 926
 927         write_constant(helper->in, "export\n");
 928
 929         for (ref = remote_refs; ref; ref = ref->next) {
 930                 char *private;
 931                 struct object_id oid;
 932
 933                 private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
 934                 if (private && !get_sha1(private, oid.hash)) {
 935                         strbuf_addf(&buf, "^%s", private);
 936                         string_list_append(&revlist_args, strbuf_detach(&buf, NULL));
 937                         oidcpy(&ref->old_oid, &oid);
 938                 }
 939                 free(private);
 940
 941                 if (ref->peer_ref) {
 942                         if (strcmp(ref->name, ref->peer_ref->name)) {
 943                                 if (!ref->deletion) {
 944                                         const char *name;
 945                                         int flag;
 946
 947                                         /* Follow symbolic refs (mainly for HEAD). */
 948                                         name = resolve_ref_unsafe(
 949                                                  ref->peer_ref->name,
 950                                                  RESOLVE_REF_READING,
 951                                                  oid.hash, &flag);
 952                                         if (!name || !(flag & REF_ISSYMREF))
 953                                                 name = ref->peer_ref->name;
 954
 955                                         strbuf_addf(&buf, "%s:%s", name, ref->name);
 956                                 } else
 957                                         strbuf_addf(&buf, ":%s", ref->name);
 958
 959                                 string_list_append(&revlist_args, "--refspec");
 960                                 string_list_append(&revlist_args, buf.buf);
 961                                 strbuf_release(&buf);
 962                         }
 963                         if (!ref->deletion)
 964                                 string_list_append(&revlist_args, ref->peer_ref->name);
 965                 }
 966         }
 967
 968         if (get_exporter(transport, &exporter, &revlist_args))
 969                 die("Couldn't run fast-export");
 970
 971         string_list_clear(&revlist_args, 1);
 972
 973         if (finish_command(&exporter))
 974                 die("Error while running fast-export");
 975         if (push_update_refs_status(data, remote_refs, flags))
 976                 return 1;
 977
 978         if (data->export_marks) {
 979                 strbuf_addf(&buf, "%s.tmp", data->export_marks);
 980                 rename(buf.buf, data->export_marks);
 981                 strbuf_release(&buf);
 982         }
 983
 984         return 0;
 985 }
 986
 987 static int push_refs(struct transport *transport,
 988                 struct ref *remote_refs, int flags)
 989 {
 990         struct helper_data *data = transport->data;
 991
 992         if (process_connect(transport, 1)) {
 993                 do_take_over(transport);
 994                 return transport->push_refs(transport, remote_refs, flags);
 995         }
 996
 997         if (!remote_refs) {
 998                 fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
 999                         "Perhaps you should specify a branch such as 'master'.\n");
1000                 return 0;
1001         }
1002
1003         if (data->push)
1004                 return push_refs_with_push(transport, remote_refs, flags);
1005
1006         if (data->export)
1007                 return push_refs_with_export(transport, remote_refs, flags);
1008
1009         return -1;
1010 }
1011
1012
1013 static int has_attribute(const char *attrs, const char *attr) {
1014         int len;
1015         if (!attrs)
1016                 return 0;
1017
1018         len = strlen(attr);
1019         for (;;) {
1020                 const char *space = strchrnul(attrs, ' ');
1021                 if (len == space - attrs && !strncmp(attrs, attr, len))
1022                         return 1;
1023                 if (!*space)
1024                         return 0;
1025                 attrs = space + 1;
1026         }
1027 }
1028
1029 static struct ref *get_refs_list(struct transport *transport, int for_push)
1030 {
1031         struct helper_data *data = transport->data;
1032         struct child_process *helper;
1033         struct ref *ret = NULL;
1034         struct ref **tail = &ret;
1035         struct ref *posn;
1036         struct strbuf buf = STRBUF_INIT;
1037
1038         helper = get_helper(transport);
1039
1040         if (process_connect(transport, for_push)) {
1041                 do_take_over(transport);
1042                 return transport->get_refs_list(transport, for_push);
1043         }
1044
1045         if (data->push && for_push)
1046                 write_str_in_full(helper->in, "list for-push\n");
1047         else
1048                 write_str_in_full(helper->in, "list\n");
1049
1050         while (1) {
1051                 char *eov, *eon;
1052                 if (recvline(data, &buf))
1053                         exit(128);
1054
1055                 if (!*buf.buf)
1056                         break;
1057
1058                 eov = strchr(buf.buf, ' ');
1059                 if (!eov)
1060                         die("Malformed response in ref list: %s", buf.buf);
1061                 eon = strchr(eov + 1, ' ');
1062                 *eov = '\0';
1063                 if (eon)
1064                         *eon = '\0';
1065                 *tail = alloc_ref(eov + 1);
1066                 if (buf.buf[0] == '@')
1067                         (*tail)->symref = xstrdup(buf.buf + 1);
1068                 else if (buf.buf[0] != '?')
1069                         get_oid_hex(buf.buf, &(*tail)->old_oid);
1070                 if (eon) {
1071                         if (has_attribute(eon + 1, "unchanged")) {
1072                                 (*tail)->status |= REF_STATUS_UPTODATE;
1073                                 if (read_ref((*tail)->name,
1074                                              (*tail)->old_oid.hash) < 0)
1075                                         die(_("Could not read ref %s"),
1076                                             (*tail)->name);
1077                         }
1078                 }
1079                 tail = &((*tail)->next);
1080         }
1081         if (debug)
1082                 fprintf(stderr, "Debug: Read ref listing.\n");
1083         strbuf_release(&buf);
1084
1085         for (posn = ret; posn; posn = posn->next)
1086                 resolve_remote_symref(posn, ret);
1087
1088         return ret;
1089 }
1090
1091 int transport_helper_init(struct transport *transport, const char *name)
1092 {
1093         struct helper_data *data = xcalloc(1, sizeof(*data));
1094         data->name = name;
1095
1096         transport_check_allowed(name);
1097
1098         if (getenv("GIT_TRANSPORT_HELPER_DEBUG"))
1099                 debug = 1;
1100
1101         transport->data = data;
1102         transport->set_option = set_helper_option;
1103         transport->get_refs_list = get_refs_list;
1104         transport->fetch = fetch;
1105         transport->push_refs = push_refs;
1106         transport->disconnect = release_helper;
1107         transport->connect = connect_helper;
1108         transport->smart_options = &(data->transport_options);
1109         return 0;
1110 }
1111
1112 /*
1113  * Linux pipes can buffer 65536 bytes at once (and most platforms can
1114  * buffer less), so attempt reads and writes with up to that size.
1115  */
1116 #define BUFFERSIZE 65536
1117 /* This should be enough to hold debugging message. */
1118 #define PBUFFERSIZE 8192
1119
1120 /* Print bidirectional transfer loop debug message. */
1121 __attribute__((format (printf, 1, 2)))
1122 static void transfer_debug(const char *fmt, ...)
1123 {
1124         va_list args;
1125         char msgbuf[PBUFFERSIZE];
1126         static int debug_enabled = -1;
1127
1128         if (debug_enabled < 0)
1129                 debug_enabled = getenv("GIT_TRANSLOOP_DEBUG") ? 1 : 0;
1130         if (!debug_enabled)
1131                 return;
1132
1133         va_start(args, fmt);
1134         vsnprintf(msgbuf, PBUFFERSIZE, fmt, args);
1135         va_end(args);
1136         fprintf(stderr, "Transfer loop debugging: %s\n", msgbuf);
1137 }
1138
1139 /* Stream state: More data may be coming in this direction. */
1140 #define SSTATE_TRANSFERRING 0
1141 /*
1142  * Stream state: No more data coming in this direction, flushing rest of
1143  * data.
1144  */
1145 #define SSTATE_FLUSHING 1
1146 /* Stream state: Transfer in this direction finished. */
1147 #define SSTATE_FINISHED 2
1148
1149 #define STATE_NEEDS_READING(state) ((state) <= SSTATE_TRANSFERRING)
1150 #define STATE_NEEDS_WRITING(state) ((state) <= SSTATE_FLUSHING)
1151 #define STATE_NEEDS_CLOSING(state) ((state) == SSTATE_FLUSHING)
1152
1153 /* Unidirectional transfer. */
1154 struct unidirectional_transfer {
1155         /* Source */
1156         int src;
1157         /* Destination */
1158         int dest;
1159         /* Is source socket? */
1160         int src_is_sock;
1161         /* Is destination socket? */
1162         int dest_is_sock;
1163         /* Transfer state (TRANSFERRING/FLUSHING/FINISHED) */
1164         int state;
1165         /* Buffer. */
1166         char buf[BUFFERSIZE];
1167         /* Buffer used. */
1168         size_t bufuse;
1169         /* Name of source. */
1170         const char *src_name;
1171         /* Name of destination. */
1172         const char *dest_name;
1173 };
1174
1175 /* Closes the target (for writing) if transfer has finished. */
1176 static void udt_close_if_finished(struct unidirectional_transfer *t)
1177 {
1178         if (STATE_NEEDS_CLOSING(t->state) && !t->bufuse) {
1179                 t->state = SSTATE_FINISHED;
1180                 if (t->dest_is_sock)
1181                         shutdown(t->dest, SHUT_WR);
1182                 else
1183                         close(t->dest);
1184                 transfer_debug("Closed %s.", t->dest_name);
1185         }
1186 }
1187
1188 /*
1189  * Tries to read data from source into buffer. If buffer is full,
1190  * no data is read. Returns 0 on success, -1 on error.
1191  */
1192 static int udt_do_read(struct unidirectional_transfer *t)
1193 {
1194         ssize_t bytes;
1195
1196         if (t->bufuse == BUFFERSIZE)
1197                 return 0;       /* No space for more. */
1198
1199         transfer_debug("%s is readable", t->src_name);
1200         bytes = read(t->src, t->buf + t->bufuse, BUFFERSIZE - t->bufuse);
1201         if (bytes < 0 && errno != EWOULDBLOCK && errno != EAGAIN &&
1202                 errno != EINTR) {
1203                 error_errno("read(%s) failed", t->src_name);
1204                 return -1;
1205         } else if (bytes == 0) {
1206                 transfer_debug("%s EOF (with %i bytes in buffer)",
1207                         t->src_name, (int)t->bufuse);
1208                 t->state = SSTATE_FLUSHING;
1209         } else if (bytes > 0) {
1210                 t->bufuse += bytes;
1211                 transfer_debug("Read %i bytes from %s (buffer now at %i)",
1212                         (int)bytes, t->src_name, (int)t->bufuse);
1213         }
1214         return 0;
1215 }
1216
1217 /* Tries to write data from buffer into destination. If buffer is empty,
1218  * no data is written. Returns 0 on success, -1 on error.
1219  */
1220 static int udt_do_write(struct unidirectional_transfer *t)
1221 {
1222         ssize_t bytes;
1223
1224         if (t->bufuse == 0)
1225                 return 0;       /* Nothing to write. */
1226
1227         transfer_debug("%s is writable", t->dest_name);
1228         bytes = xwrite(t->dest, t->buf, t->bufuse);
1229         if (bytes < 0 && errno != EWOULDBLOCK) {
1230                 error_errno("write(%s) failed", t->dest_name);
1231                 return -1;
1232         } else if (bytes > 0) {
1233                 t->bufuse -= bytes;
1234                 if (t->bufuse)
1235                         memmove(t->buf, t->buf + bytes, t->bufuse);
1236                 transfer_debug("Wrote %i bytes to %s (buffer now at %i)",
1237                         (int)bytes, t->dest_name, (int)t->bufuse);
1238         }
1239         return 0;
1240 }
1241
1242
1243 /* State of bidirectional transfer loop. */
1244 struct bidirectional_transfer_state {
1245         /* Direction from program to git. */
1246         struct unidirectional_transfer ptg;
1247         /* Direction from git to program. */
1248         struct unidirectional_transfer gtp;
1249 };
1250
1251 static void *udt_copy_task_routine(void *udt)
1252 {
1253         struct unidirectional_transfer *t = (struct unidirectional_transfer *)udt;
1254         while (t->state != SSTATE_FINISHED) {
1255                 if (STATE_NEEDS_READING(t->state))
1256                         if (udt_do_read(t))
1257                                 return NULL;
1258                 if (STATE_NEEDS_WRITING(t->state))
1259                         if (udt_do_write(t))
1260                                 return NULL;
1261                 if (STATE_NEEDS_CLOSING(t->state))
1262                         udt_close_if_finished(t);
1263         }
1264         return udt;     /* Just some non-NULL value. */
1265 }
1266
1267 #ifndef NO_PTHREADS
1268
1269 /*
1270  * Join thread, with appropriate errors on failure. Name is name for the
1271  * thread (for error messages). Returns 0 on success, 1 on failure.
1272  */
1273 static int tloop_join(pthread_t thread, const char *name)
1274 {
1275         int err;
1276         void *tret;
1277         err = pthread_join(thread, &tret);
1278         if (!tret) {
1279                 error("%s thread failed", name);
1280                 return 1;
1281         }
1282         if (err) {
1283                 error("%s thread failed to join: %s", name, strerror(err));
1284                 return 1;
1285         }
1286         return 0;
1287 }
1288
1289 /*
1290  * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1291  * -1 on failure.
1292  */
1293 static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1294 {
1295         pthread_t gtp_thread;
1296         pthread_t ptg_thread;
1297         int err;
1298         int ret = 0;
1299         err = pthread_create(&gtp_thread, NULL, udt_copy_task_routine,
1300                 &s->gtp);
1301         if (err)
1302                 die("Can't start thread for copying data: %s", strerror(err));
1303         err = pthread_create(&ptg_thread, NULL, udt_copy_task_routine,
1304                 &s->ptg);
1305         if (err)
1306                 die("Can't start thread for copying data: %s", strerror(err));
1307
1308         ret |= tloop_join(gtp_thread, "Git to program copy");
1309         ret |= tloop_join(ptg_thread, "Program to git copy");
1310         return ret;
1311 }
1312 #else
1313
1314 /* Close the source and target (for writing) for transfer. */
1315 static void udt_kill_transfer(struct unidirectional_transfer *t)
1316 {
1317         t->state = SSTATE_FINISHED;
1318         /*
1319          * Socket read end left open isn't a disaster if nobody
1320          * attempts to read from it (mingw compat headers do not
1321          * have SHUT_RD)...
1322          *
1323          * We can't fully close the socket since otherwise gtp
1324          * task would first close the socket it sends data to
1325          * while closing the ptg file descriptors.
1326          */
1327         if (!t->src_is_sock)
1328                 close(t->src);
1329         if (t->dest_is_sock)
1330                 shutdown(t->dest, SHUT_WR);
1331         else
1332                 close(t->dest);
1333 }
1334
1335 /*
1336  * Join process, with appropriate errors on failure. Name is name for the
1337  * process (for error messages). Returns 0 on success, 1 on failure.
1338  */
1339 static int tloop_join(pid_t pid, const char *name)
1340 {
1341         int tret;
1342         if (waitpid(pid, &tret, 0) < 0) {
1343                 error_errno("%s process failed to wait", name);
1344                 return 1;
1345         }
1346         if (!WIFEXITED(tret) || WEXITSTATUS(tret)) {
1347                 error("%s process failed", name);
1348                 return 1;
1349         }
1350         return 0;
1351 }
1352
1353 /*
1354  * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1355  * -1 on failure.
1356  */
1357 static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1358 {
1359         pid_t pid1, pid2;
1360         int ret = 0;
1361
1362         /* Fork thread #1: git to program. */
1363         pid1 = fork();
1364         if (pid1 < 0)
1365                 die_errno("Can't start thread for copying data");
1366         else if (pid1 == 0) {
1367                 udt_kill_transfer(&s->ptg);
1368                 exit(udt_copy_task_routine(&s->gtp) ? 0 : 1);
1369         }
1370
1371         /* Fork thread #2: program to git. */
1372         pid2 = fork();
1373         if (pid2 < 0)
1374                 die_errno("Can't start thread for copying data");
1375         else if (pid2 == 0) {
1376                 udt_kill_transfer(&s->gtp);
1377                 exit(udt_copy_task_routine(&s->ptg) ? 0 : 1);
1378         }
1379
1380         /*
1381          * Close both streams in parent as to not interfere with
1382          * end of file detection and wait for both tasks to finish.
1383          */
1384         udt_kill_transfer(&s->gtp);
1385         udt_kill_transfer(&s->ptg);
1386         ret |= tloop_join(pid1, "Git to program copy");
1387         ret |= tloop_join(pid2, "Program to git copy");
1388         return ret;
1389 }
1390 #endif
1391
1392 /*
1393  * Copies data from stdin to output and from input to stdout simultaneously.
1394  * Additionally filtering through given filter. If filter is NULL, uses
1395  * identity filter.
1396  */
1397 int bidirectional_transfer_loop(int input, int output)
1398 {
1399         struct bidirectional_transfer_state state;
1400
1401         /* Fill the state fields. */
1402         state.ptg.src = input;
1403         state.ptg.dest = 1;
1404         state.ptg.src_is_sock = (input == output);
1405         state.ptg.dest_is_sock = 0;
1406         state.ptg.state = SSTATE_TRANSFERRING;
1407         state.ptg.bufuse = 0;
1408         state.ptg.src_name = "remote input";
1409         state.ptg.dest_name = "stdout";
1410
1411         state.gtp.src = 0;
1412         state.gtp.dest = output;
1413         state.gtp.src_is_sock = 0;
1414         state.gtp.dest_is_sock = (input == output);
1415         state.gtp.state = SSTATE_TRANSFERRING;
1416         state.gtp.bufuse = 0;
1417         state.gtp.src_name = "stdin";
1418         state.gtp.dest_name = "remote output";
1419
1420         return tloop_spawnwait_tasks(&state);
1421 }