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

   1 #include "cache.h"
   2 #include "transport.h"
   3 #include "quote.h"
   4 #include "run-command.h"
   5 #include "commit.h"
   6 #include "diff.h"
   7 #include "revision.h"
   8 #include "remote.h"
   9 #include "string-list.h"
  10 #include "thread-utils.h"
  11 #include "sigchain.h"
  12 #include "argv-array.h"
  13 #include "refs.h"
  14 #include "transport-internal.h"
  15 #include "protocol.h"
  16
  17 static int debug;
  18
  19 struct helper_data {
  20         const char *name;
  21         struct child_process *helper;
  22         FILE *out;
  23         unsigned fetch : 1,
  24                 import : 1,
  25                 bidi_import : 1,
  26                 export : 1,
  27                 option : 1,
  28                 push : 1,
  29                 connect : 1,
  30                 stateless_connect : 1,
  31                 signed_tags : 1,
  32                 check_connectivity : 1,
  33                 no_disconnect_req : 1,
  34                 no_private_update : 1;
  35         char *export_marks;
  36         char *import_marks;
  37         /* These go from remote name (as in "list") to private name */
  38         struct refspec *refspecs;
  39         int refspec_nr;
  40         /* Transport options for fetch-pack/send-pack (should one of
  41          * those be invoked).
  42          */
  43         struct git_transport_options transport_options;
  44 };
  45
  46 static void sendline(struct helper_data *helper, struct strbuf *buffer)
  47 {
  48         if (debug)
  49                 fprintf(stderr, "Debug: Remote helper: -> %s", buffer->buf);
  50         if (write_in_full(helper->helper->in, buffer->buf, buffer->len) < 0)
  51                 die_errno("Full write to remote helper failed");
  52 }
  53
  54 static int recvline_fh(FILE *helper, struct strbuf *buffer)
  55 {
  56         strbuf_reset(buffer);
  57         if (debug)
  58                 fprintf(stderr, "Debug: Remote helper: Waiting...\n");
  59         if (strbuf_getline(buffer, helper) == EOF) {
  60                 if (debug)
  61                         fprintf(stderr, "Debug: Remote helper quit.\n");
  62                 return 1;
  63         }
  64
  65         if (debug)
  66                 fprintf(stderr, "Debug: Remote helper: <- %s\n", buffer->buf);
  67         return 0;
  68 }
  69
  70 static int recvline(struct helper_data *helper, struct strbuf *buffer)
  71 {
  72         return recvline_fh(helper->out, buffer);
  73 }
  74
  75 static void write_constant(int fd, const char *str)
  76 {
  77         if (debug)
  78                 fprintf(stderr, "Debug: Remote helper: -> %s", str);
  79         if (write_in_full(fd, str, strlen(str)) < 0)
  80                 die_errno("Full write to remote helper failed");
  81 }
  82
  83 static const char *remove_ext_force(const char *url)
  84 {
  85         if (url) {
  86                 const char *colon = strchr(url, ':');
  87                 if (colon && colon[1] == ':')
  88                         return colon + 2;
  89         }
  90         return url;
  91 }
  92
  93 static void do_take_over(struct transport *transport)
  94 {
  95         struct helper_data *data;
  96         data = (struct helper_data *)transport->data;
  97         transport_take_over(transport, data->helper);
  98         fclose(data->out);
  99         free(data);
 100 }
 101
 102 static void standard_options(struct transport *t);
 103
 104 static struct child_process *get_helper(struct transport *transport)
 105 {
 106         struct helper_data *data = transport->data;
 107         struct strbuf buf = STRBUF_INIT;
 108         struct child_process *helper;
 109         const char **refspecs = NULL;
 110         int refspec_nr = 0;
 111         int refspec_alloc = 0;
 112         int duped;
 113         int code;
 114
 115         if (data->helper)
 116                 return data->helper;
 117
 118         helper = xmalloc(sizeof(*helper));
 119         child_process_init(helper);
 120         helper->in = -1;
 121         helper->out = -1;
 122         helper->err = 0;
 123         argv_array_pushf(&helper->args, "git-remote-%s", data->name);
 124         argv_array_push(&helper->args, transport->remote->name);
 125         argv_array_push(&helper->args, remove_ext_force(transport->url));
 126         helper->git_cmd = 0;
 127         helper->silent_exec_failure = 1;
 128
 129         if (have_git_dir())
 130                 argv_array_pushf(&helper->env_array, "%s=%s",
 131                                  GIT_DIR_ENVIRONMENT, get_git_dir());
 132
 133         code = start_command(helper);
 134         if (code < 0 && errno == ENOENT)
 135                 die("Unable to find remote helper for '%s'", data->name);
 136         else if (code != 0)
 137                 exit(code);
 138
 139         data->helper = helper;
 140         data->no_disconnect_req = 0;
 141
 142         /*
 143          * Open the output as FILE* so strbuf_getline_*() family of
 144          * functions can be used.
 145          * Do this with duped fd because fclose() will close the fd,
 146          * and stuff like taking over will require the fd to remain.
 147          */
 148         duped = dup(helper->out);
 149         if (duped < 0)
 150                 die_errno("Can't dup helper output fd");
 151         data->out = xfdopen(duped, "r");
 152
 153         write_constant(helper->in, "capabilities\n");
 154
 155         while (1) {
 156                 const char *capname, *arg;
 157                 int mandatory = 0;
 158                 if (recvline(data, &buf))
 159                         exit(128);
 160
 161                 if (!*buf.buf)
 162                         break;
 163
 164                 if (*buf.buf == '*') {
 165                         capname = buf.buf + 1;
 166                         mandatory = 1;
 167                 } else
 168                         capname = buf.buf;
 169
 170                 if (debug)
 171                         fprintf(stderr, "Debug: Got cap %s\n", capname);
 172                 if (!strcmp(capname, "fetch"))
 173                         data->fetch = 1;
 174                 else if (!strcmp(capname, "option"))
 175                         data->option = 1;
 176                 else if (!strcmp(capname, "push"))
 177                         data->push = 1;
 178                 else if (!strcmp(capname, "import"))
 179                         data->import = 1;
 180                 else if (!strcmp(capname, "bidi-import"))
 181                         data->bidi_import = 1;
 182                 else if (!strcmp(capname, "export"))
 183                         data->export = 1;
 184                 else if (!strcmp(capname, "check-connectivity"))
 185                         data->check_connectivity = 1;
 186                 else if (!data->refspecs && skip_prefix(capname, "refspec ", &arg)) {
 187                         ALLOC_GROW(refspecs,
 188                                    refspec_nr + 1,
 189                                    refspec_alloc);
 190                         refspecs[refspec_nr++] = xstrdup(arg);
 191                 } else if (!strcmp(capname, "connect")) {
 192                         data->connect = 1;
 193                 } else if (!strcmp(capname, "stateless-connect")) {
 194                         data->stateless_connect = 1;
 195                 } else if (!strcmp(capname, "signed-tags")) {
 196                         data->signed_tags = 1;
 197                 } else if (skip_prefix(capname, "export-marks ", &arg)) {
 198                         data->export_marks = xstrdup(arg);
 199                 } else if (skip_prefix(capname, "import-marks ", &arg)) {
 200                         data->import_marks = xstrdup(arg);
 201                 } else if (starts_with(capname, "no-private-update")) {
 202                         data->no_private_update = 1;
 203                 } else if (mandatory) {
 204                         die("Unknown mandatory capability %s. This remote "
 205                             "helper probably needs newer version of Git.",
 206                             capname);
 207                 }
 208         }
 209         if (refspecs) {
 210                 int i;
 211                 data->refspec_nr = refspec_nr;
 212                 data->refspecs = parse_fetch_refspec(refspec_nr, refspecs);
 213                 for (i = 0; i < refspec_nr; i++)
 214                         free((char *)refspecs[i]);
 215                 free(refspecs);
 216         } else if (data->import || data->bidi_import || data->export) {
 217                 warning("This remote helper should implement refspec capability.");
 218         }
 219         strbuf_release(&buf);
 220         if (debug)
 221                 fprintf(stderr, "Debug: Capabilities complete.\n");
 222         standard_options(transport);
 223         return data->helper;
 224 }
 225
 226 static int disconnect_helper(struct transport *transport)
 227 {
 228         struct helper_data *data = transport->data;
 229         int res = 0;
 230
 231         if (data->helper) {
 232                 if (debug)
 233                         fprintf(stderr, "Debug: Disconnecting.\n");
 234                 if (!data->no_disconnect_req) {
 235                         /*
 236                          * Ignore write errors; there's nothing we can do,
 237                          * since we're about to close the pipe anyway. And the
 238                          * most likely error is EPIPE due to the helper dying
 239                          * to report an error itself.
 240                          */
 241                         sigchain_push(SIGPIPE, SIG_IGN);
 242                         xwrite(data->helper->in, "\n", 1);
 243                         sigchain_pop(SIGPIPE);
 244                 }
 245                 close(data->helper->in);
 246                 close(data->helper->out);
 247                 fclose(data->out);
 248                 res = finish_command(data->helper);
 249                 FREE_AND_NULL(data->helper);
 250         }
 251         return res;
 252 }
 253
 254 static const char *unsupported_options[] = {
 255         TRANS_OPT_UPLOADPACK,
 256         TRANS_OPT_RECEIVEPACK,
 257         TRANS_OPT_THIN,
 258         TRANS_OPT_KEEP
 259         };
 260
 261 static const char *boolean_options[] = {
 262         TRANS_OPT_THIN,
 263         TRANS_OPT_KEEP,
 264         TRANS_OPT_FOLLOWTAGS,
 265         TRANS_OPT_DEEPEN_RELATIVE
 266         };
 267
 268 static int strbuf_set_helper_option(struct helper_data *data,
 269                                     struct strbuf *buf)
 270 {
 271         int ret;
 272
 273         sendline(data, buf);
 274         if (recvline(data, buf))
 275                 exit(128);
 276
 277         if (!strcmp(buf->buf, "ok"))
 278                 ret = 0;
 279         else if (starts_with(buf->buf, "error"))
 280                 ret = -1;
 281         else if (!strcmp(buf->buf, "unsupported"))
 282                 ret = 1;
 283         else {
 284                 warning("%s unexpectedly said: '%s'", data->name, buf->buf);
 285                 ret = 1;
 286         }
 287         return ret;
 288 }
 289
 290 static int string_list_set_helper_option(struct helper_data *data,
 291                                          const char *name,
 292                                          struct string_list *list)
 293 {
 294         struct strbuf buf = STRBUF_INIT;
 295         int i, ret = 0;
 296
 297         for (i = 0; i < list->nr; i++) {
 298                 strbuf_addf(&buf, "option %s ", name);
 299                 quote_c_style(list->items[i].string, &buf, NULL, 0);
 300                 strbuf_addch(&buf, '\n');
 301
 302                 if ((ret = strbuf_set_helper_option(data, &buf)))
 303                         break;
 304                 strbuf_reset(&buf);
 305         }
 306         strbuf_release(&buf);
 307         return ret;
 308 }
 309
 310 static int set_helper_option(struct transport *transport,
 311                           const char *name, const char *value)
 312 {
 313         struct helper_data *data = transport->data;
 314         struct strbuf buf = STRBUF_INIT;
 315         int i, ret, is_bool = 0;
 316
 317         get_helper(transport);
 318
 319         if (!data->option)
 320                 return 1;
 321
 322         if (!strcmp(name, "deepen-not"))
 323                 return string_list_set_helper_option(data, name,
 324                                                      (struct string_list *)value);
 325
 326         for (i = 0; i < ARRAY_SIZE(unsupported_options); i++) {
 327                 if (!strcmp(name, unsupported_options[i]))
 328                         return 1;
 329         }
 330
 331         for (i = 0; i < ARRAY_SIZE(boolean_options); i++) {
 332                 if (!strcmp(name, boolean_options[i])) {
 333                         is_bool = 1;
 334                         break;
 335                 }
 336         }
 337
 338         strbuf_addf(&buf, "option %s ", name);
 339         if (is_bool)
 340                 strbuf_addstr(&buf, value ? "true" : "false");
 341         else
 342                 quote_c_style(value, &buf, NULL, 0);
 343         strbuf_addch(&buf, '\n');
 344
 345         ret = strbuf_set_helper_option(data, &buf);
 346         strbuf_release(&buf);
 347         return ret;
 348 }
 349
 350 static void standard_options(struct transport *t)
 351 {
 352         char buf[16];
 353         int v = t->verbose;
 354
 355         set_helper_option(t, "progress", t->progress ? "true" : "false");
 356
 357         xsnprintf(buf, sizeof(buf), "%d", v + 1);
 358         set_helper_option(t, "verbosity", buf);
 359
 360         switch (t->family) {
 361         case TRANSPORT_FAMILY_ALL:
 362                 /*
 363                  * this is already the default,
 364                  * do not break old remote helpers by setting "all" here
 365                  */
 366                 break;
 367         case TRANSPORT_FAMILY_IPV4:
 368                 set_helper_option(t, "family", "ipv4");
 369                 break;
 370         case TRANSPORT_FAMILY_IPV6:
 371                 set_helper_option(t, "family", "ipv6");
 372                 break;
 373         }
 374 }
 375
 376 static int release_helper(struct transport *transport)
 377 {
 378         int res = 0;
 379         struct helper_data *data = transport->data;
 380         free_refspec(data->refspec_nr, data->refspecs);
 381         data->refspecs = NULL;
 382         res = disconnect_helper(transport);
 383         free(transport->data);
 384         return res;
 385 }
 386
 387 static int fetch_with_fetch(struct transport *transport,
 388                             int nr_heads, struct ref **to_fetch)
 389 {
 390         struct helper_data *data = transport->data;
 391         int i;
 392         struct strbuf buf = STRBUF_INIT;
 393
 394         for (i = 0; i < nr_heads; i++) {
 395                 const struct ref *posn = to_fetch[i];
 396                 if (posn->status & REF_STATUS_UPTODATE)
 397                         continue;
 398
 399                 strbuf_addf(&buf, "fetch %s %s\n",
 400                             oid_to_hex(&posn->old_oid),
 401                             posn->symref ? posn->symref : posn->name);
 402         }
 403
 404         strbuf_addch(&buf, '\n');
 405         sendline(data, &buf);
 406
 407         while (1) {
 408                 if (recvline(data, &buf))
 409                         exit(128);
 410
 411                 if (starts_with(buf.buf, "lock ")) {
 412                         const char *name = buf.buf + 5;
 413                         if (transport->pack_lockfile)
 414                                 warning("%s also locked %s", data->name, name);
 415                         else
 416                                 transport->pack_lockfile = xstrdup(name);
 417                 }
 418                 else if (data->check_connectivity &&
 419                          data->transport_options.check_self_contained_and_connected &&
 420                          !strcmp(buf.buf, "connectivity-ok"))
 421                         data->transport_options.self_contained_and_connected = 1;
 422                 else if (!buf.len)
 423                         break;
 424                 else
 425                         warning("%s unexpectedly said: '%s'", data->name, buf.buf);
 426         }
 427         strbuf_release(&buf);
 428         return 0;
 429 }
 430
 431 static int get_importer(struct transport *transport, struct child_process *fastimport)
 432 {
 433         struct child_process *helper = get_helper(transport);
 434         struct helper_data *data = transport->data;
 435         int cat_blob_fd, code;
 436         child_process_init(fastimport);
 437         fastimport->in = helper->out;
 438         argv_array_push(&fastimport->args, "fast-import");
 439         argv_array_push(&fastimport->args, debug ? "--stats" : "--quiet");
 440
 441         if (data->bidi_import) {
 442                 cat_blob_fd = xdup(helper->in);
 443                 argv_array_pushf(&fastimport->args, "--cat-blob-fd=%d", cat_blob_fd);
 444         }
 445         fastimport->git_cmd = 1;
 446
 447         code = start_command(fastimport);
 448         return code;
 449 }
 450
 451 static int get_exporter(struct transport *transport,
 452                         struct child_process *fastexport,
 453                         struct string_list *revlist_args)
 454 {
 455         struct helper_data *data = transport->data;
 456         struct child_process *helper = get_helper(transport);
 457         int i;
 458
 459         child_process_init(fastexport);
 460
 461         /* we need to duplicate helper->in because we want to use it after
 462          * fastexport is done with it. */
 463         fastexport->out = dup(helper->in);
 464         argv_array_push(&fastexport->args, "fast-export");
 465         argv_array_push(&fastexport->args, "--use-done-feature");
 466         argv_array_push(&fastexport->args, data->signed_tags ?
 467                 "--signed-tags=verbatim" : "--signed-tags=warn-strip");
 468         if (data->export_marks)
 469                 argv_array_pushf(&fastexport->args, "--export-marks=%s.tmp", data->export_marks);
 470         if (data->import_marks)
 471                 argv_array_pushf(&fastexport->args, "--import-marks=%s", data->import_marks);
 472
 473         for (i = 0; i < revlist_args->nr; i++)
 474                 argv_array_push(&fastexport->args, revlist_args->items[i].string);
 475
 476         fastexport->git_cmd = 1;
 477         return start_command(fastexport);
 478 }
 479
 480 static int fetch_with_import(struct transport *transport,
 481                              int nr_heads, struct ref **to_fetch)
 482 {
 483         struct child_process fastimport;
 484         struct helper_data *data = transport->data;
 485         int i;
 486         struct ref *posn;
 487         struct strbuf buf = STRBUF_INIT;
 488
 489         get_helper(transport);
 490
 491         if (get_importer(transport, &fastimport))
 492                 die("Couldn't run fast-import");
 493
 494         for (i = 0; i < nr_heads; i++) {
 495                 posn = to_fetch[i];
 496                 if (posn->status & REF_STATUS_UPTODATE)
 497                         continue;
 498
 499                 strbuf_addf(&buf, "import %s\n",
 500                             posn->symref ? posn->symref : posn->name);
 501                 sendline(data, &buf);
 502                 strbuf_reset(&buf);
 503         }
 504
 505         write_constant(data->helper->in, "\n");
 506         /*
 507          * remote-helpers that advertise the bidi-import capability are required to
 508          * buffer the complete batch of import commands until this newline before
 509          * sending data to fast-import.
 510          * These helpers read back data from fast-import on their stdin, which could
 511          * be mixed with import commands, otherwise.
 512          */
 513
 514         if (finish_command(&fastimport))
 515                 die("Error while running fast-import");
 516
 517         /*
 518          * The fast-import stream of a remote helper that advertises
 519          * the "refspec" capability writes to the refs named after the
 520          * right hand side of the first refspec matching each ref we
 521          * were fetching.
 522          *
 523          * (If no "refspec" capability was specified, for historical
 524          * reasons we default to the equivalent of *:*.)
 525          *
 526          * Store the result in to_fetch[i].old_sha1.  Callers such
 527          * as "git fetch" can use the value to write feedback to the
 528          * terminal, populate FETCH_HEAD, and determine what new value
 529          * should be written to peer_ref if the update is a
 530          * fast-forward or this is a forced update.
 531          */
 532         for (i = 0; i < nr_heads; i++) {
 533                 char *private, *name;
 534                 posn = to_fetch[i];
 535                 if (posn->status & REF_STATUS_UPTODATE)
 536                         continue;
 537                 name = posn->symref ? posn->symref : posn->name;
 538                 if (data->refspecs)
 539                         private = apply_refspecs(data->refspecs, data->refspec_nr, name);
 540                 else
 541                         private = xstrdup(name);
 542                 if (private) {
 543                         if (read_ref(private, &posn->old_oid) < 0)
 544                                 die("Could not read ref %s", private);
 545                         free(private);
 546                 }
 547         }
 548         strbuf_release(&buf);
 549         return 0;
 550 }
 551
 552 static int run_connect(struct transport *transport, struct strbuf *cmdbuf)
 553 {
 554         struct helper_data *data = transport->data;
 555         int ret = 0;
 556         int duped;
 557         FILE *input;
 558         struct child_process *helper;
 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         sendline(data, cmdbuf);
 575         if (recvline_fh(input, cmdbuf))
 576                 exit(128);
 577
 578         if (!strcmp(cmdbuf->buf, "")) {
 579                 data->no_disconnect_req = 1;
 580                 if (debug)
 581                         fprintf(stderr, "Debug: Smart transport connection "
 582                                 "ready.\n");
 583                 ret = 1;
 584         } else if (!strcmp(cmdbuf->buf, "fallback")) {
 585                 if (debug)
 586                         fprintf(stderr, "Debug: Falling back to dumb "
 587                                 "transport.\n");
 588         } else {
 589                 die("Unknown response to connect: %s",
 590                         cmdbuf->buf);
 591         }
 592
 593         fclose(input);
 594         return ret;
 595 }
 596
 597 static int process_connect_service(struct transport *transport,
 598                                    const char *name, const char *exec)
 599 {
 600         struct helper_data *data = transport->data;
 601         struct strbuf cmdbuf = STRBUF_INIT;
 602         int ret = 0;
 603
 604         /*
 605          * Handle --upload-pack and friends. This is fire and forget...
 606          * just warn if it fails.
 607          */
 608         if (strcmp(name, exec)) {
 609                 int r = set_helper_option(transport, "servpath", exec);
 610                 if (r > 0)
 611                         warning("Setting remote service path not supported by protocol.");
 612                 else if (r < 0)
 613                         warning("Invalid remote service path.");
 614         }
 615
 616         if (data->connect) {
 617                 strbuf_addf(&cmdbuf, "connect %s\n", name);
 618                 ret = run_connect(transport, &cmdbuf);
 619         } else if (data->stateless_connect &&
 620                    (get_protocol_version_config() == protocol_v2) &&
 621                    !strcmp("git-upload-pack", name)) {
 622                 strbuf_addf(&cmdbuf, "stateless-connect %s\n", name);
 623                 ret = run_connect(transport, &cmdbuf);
 624                 if (ret)
 625                         transport->stateless_rpc = 1;
 626         }
 627
 628         strbuf_release(&cmdbuf);
 629         return ret;
 630 }
 631
 632 static int process_connect(struct transport *transport,
 633                                      int for_push)
 634 {
 635         struct helper_data *data = transport->data;
 636         const char *name;
 637         const char *exec;
 638
 639         name = for_push ? "git-receive-pack" : "git-upload-pack";
 640         if (for_push)
 641                 exec = data->transport_options.receivepack;
 642         else
 643                 exec = data->transport_options.uploadpack;
 644
 645         return process_connect_service(transport, name, exec);
 646 }
 647
 648 static int connect_helper(struct transport *transport, const char *name,
 649                    const char *exec, int fd[2])
 650 {
 651         struct helper_data *data = transport->data;
 652
 653         /* Get_helper so connect is inited. */
 654         get_helper(transport);
 655         if (!data->connect)
 656                 die("Operation not supported by protocol.");
 657
 658         if (!process_connect_service(transport, name, exec))
 659                 die("Can't connect to subservice %s.", name);
 660
 661         fd[0] = data->helper->out;
 662         fd[1] = data->helper->in;
 663         return 0;
 664 }
 665
 666 static int fetch(struct transport *transport,
 667                  int nr_heads, struct ref **to_fetch)
 668 {
 669         struct helper_data *data = transport->data;
 670         int i, count;
 671
 672         if (process_connect(transport, 0)) {
 673                 do_take_over(transport);
 674                 return transport->vtable->fetch(transport, nr_heads, to_fetch);
 675         }
 676
 677         count = 0;
 678         for (i = 0; i < nr_heads; i++)
 679                 if (!(to_fetch[i]->status & REF_STATUS_UPTODATE))
 680                         count++;
 681
 682         if (!count)
 683                 return 0;
 684
 685         if (data->check_connectivity &&
 686             data->transport_options.check_self_contained_and_connected)
 687                 set_helper_option(transport, "check-connectivity", "true");
 688
 689         if (transport->cloning)
 690                 set_helper_option(transport, "cloning", "true");
 691
 692         if (data->transport_options.update_shallow)
 693                 set_helper_option(transport, "update-shallow", "true");
 694
 695         if (data->fetch)
 696                 return fetch_with_fetch(transport, nr_heads, to_fetch);
 697
 698         if (data->import)
 699                 return fetch_with_import(transport, nr_heads, to_fetch);
 700
 701         return -1;
 702 }
 703
 704 static int push_update_ref_status(struct strbuf *buf,
 705                                    struct ref **ref,
 706                                    struct ref *remote_refs)
 707 {
 708         char *refname, *msg;
 709         int status, forced = 0;
 710
 711         if (starts_with(buf->buf, "ok ")) {
 712                 status = REF_STATUS_OK;
 713                 refname = buf->buf + 3;
 714         } else if (starts_with(buf->buf, "error ")) {
 715                 status = REF_STATUS_REMOTE_REJECT;
 716                 refname = buf->buf + 6;
 717         } else
 718                 die("expected ok/error, helper said '%s'", buf->buf);
 719
 720         msg = strchr(refname, ' ');
 721         if (msg) {
 722                 struct strbuf msg_buf = STRBUF_INIT;
 723                 const char *end;
 724
 725                 *msg++ = '\0';
 726                 if (!unquote_c_style(&msg_buf, msg, &end))
 727                         msg = strbuf_detach(&msg_buf, NULL);
 728                 else
 729                         msg = xstrdup(msg);
 730                 strbuf_release(&msg_buf);
 731
 732                 if (!strcmp(msg, "no match")) {
 733                         status = REF_STATUS_NONE;
 734                         FREE_AND_NULL(msg);
 735                 }
 736                 else if (!strcmp(msg, "up to date")) {
 737                         status = REF_STATUS_UPTODATE;
 738                         FREE_AND_NULL(msg);
 739                 }
 740                 else if (!strcmp(msg, "non-fast forward")) {
 741                         status = REF_STATUS_REJECT_NONFASTFORWARD;
 742                         FREE_AND_NULL(msg);
 743                 }
 744                 else if (!strcmp(msg, "already exists")) {
 745                         status = REF_STATUS_REJECT_ALREADY_EXISTS;
 746                         FREE_AND_NULL(msg);
 747                 }
 748                 else if (!strcmp(msg, "fetch first")) {
 749                         status = REF_STATUS_REJECT_FETCH_FIRST;
 750                         FREE_AND_NULL(msg);
 751                 }
 752                 else if (!strcmp(msg, "needs force")) {
 753                         status = REF_STATUS_REJECT_NEEDS_FORCE;
 754                         FREE_AND_NULL(msg);
 755                 }
 756                 else if (!strcmp(msg, "stale info")) {
 757                         status = REF_STATUS_REJECT_STALE;
 758                         FREE_AND_NULL(msg);
 759                 }
 760                 else if (!strcmp(msg, "forced update")) {
 761                         forced = 1;
 762                         FREE_AND_NULL(msg);
 763                 }
 764         }
 765
 766         if (*ref)
 767                 *ref = find_ref_by_name(*ref, refname);
 768         if (!*ref)
 769                 *ref = find_ref_by_name(remote_refs, refname);
 770         if (!*ref) {
 771                 warning("helper reported unexpected status of %s", refname);
 772                 return 1;
 773         }
 774
 775         if ((*ref)->status != REF_STATUS_NONE) {
 776                 /*
 777                  * Earlier, the ref was marked not to be pushed, so ignore the ref
 778                  * status reported by the remote helper if the latter is 'no match'.
 779                  */
 780                 if (status == REF_STATUS_NONE)
 781                         return 1;
 782         }
 783
 784         (*ref)->status = status;
 785         (*ref)->forced_update |= forced;
 786         (*ref)->remote_status = msg;
 787         return !(status == REF_STATUS_OK);
 788 }
 789
 790 static int push_update_refs_status(struct helper_data *data,
 791                                     struct ref *remote_refs,
 792                                     int flags)
 793 {
 794         struct strbuf buf = STRBUF_INIT;
 795         struct ref *ref = remote_refs;
 796         int ret = 0;
 797
 798         for (;;) {
 799                 char *private;
 800
 801                 if (recvline(data, &buf)) {
 802                         ret = 1;
 803                         break;
 804                 }
 805
 806                 if (!buf.len)
 807                         break;
 808
 809                 if (push_update_ref_status(&buf, &ref, remote_refs))
 810                         continue;
 811
 812                 if (flags & TRANSPORT_PUSH_DRY_RUN || !data->refspecs || data->no_private_update)
 813                         continue;
 814
 815                 /* propagate back the update to the remote namespace */
 816                 private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
 817                 if (!private)
 818                         continue;
 819                 update_ref("update by helper", private, &ref->new_oid, NULL,
 820                            0, 0);
 821                 free(private);
 822         }
 823         strbuf_release(&buf);
 824         return ret;
 825 }
 826
 827 static void set_common_push_options(struct transport *transport,
 828                                    const char *name, int flags)
 829 {
 830         if (flags & TRANSPORT_PUSH_DRY_RUN) {
 831                 if (set_helper_option(transport, "dry-run", "true") != 0)
 832                         die("helper %s does not support dry-run", name);
 833         } else if (flags & TRANSPORT_PUSH_CERT_ALWAYS) {
 834                 if (set_helper_option(transport, TRANS_OPT_PUSH_CERT, "true") != 0)
 835                         die("helper %s does not support --signed", name);
 836         } else if (flags & TRANSPORT_PUSH_CERT_IF_ASKED) {
 837                 if (set_helper_option(transport, TRANS_OPT_PUSH_CERT, "if-asked") != 0)
 838                         die("helper %s does not support --signed=if-asked", name);
 839         }
 840
 841         if (flags & TRANSPORT_PUSH_OPTIONS) {
 842                 struct string_list_item *item;
 843                 for_each_string_list_item(item, transport->push_options)
 844                         if (set_helper_option(transport, "push-option", item->string) != 0)
 845                                 die("helper %s does not support 'push-option'", name);
 846         }
 847 }
 848
 849 static int push_refs_with_push(struct transport *transport,
 850                                struct ref *remote_refs, int flags)
 851 {
 852         int force_all = flags & TRANSPORT_PUSH_FORCE;
 853         int mirror = flags & TRANSPORT_PUSH_MIRROR;
 854         struct helper_data *data = transport->data;
 855         struct strbuf buf = STRBUF_INIT;
 856         struct ref *ref;
 857         struct string_list cas_options = STRING_LIST_INIT_DUP;
 858         struct string_list_item *cas_option;
 859
 860         get_helper(transport);
 861         if (!data->push)
 862                 return 1;
 863
 864         for (ref = remote_refs; ref; ref = ref->next) {
 865                 if (!ref->peer_ref && !mirror)
 866                         continue;
 867
 868                 /* Check for statuses set by set_ref_status_for_push() */
 869                 switch (ref->status) {
 870                 case REF_STATUS_REJECT_NONFASTFORWARD:
 871                 case REF_STATUS_REJECT_STALE:
 872                 case REF_STATUS_REJECT_ALREADY_EXISTS:
 873                 case REF_STATUS_UPTODATE:
 874                         continue;
 875                 default:
 876                         ; /* do nothing */
 877                 }
 878
 879                 if (force_all)
 880                         ref->force = 1;
 881
 882                 strbuf_addstr(&buf, "push ");
 883                 if (!ref->deletion) {
 884                         if (ref->force)
 885                                 strbuf_addch(&buf, '+');
 886                         if (ref->peer_ref)
 887                                 strbuf_addstr(&buf, ref->peer_ref->name);
 888                         else
 889                                 strbuf_addstr(&buf, oid_to_hex(&ref->new_oid));
 890                 }
 891                 strbuf_addch(&buf, ':');
 892                 strbuf_addstr(&buf, ref->name);
 893                 strbuf_addch(&buf, '\n');
 894
 895                 /*
 896                  * The "--force-with-lease" options without explicit
 897                  * values to expect have already been expanded into
 898                  * the ref->old_oid_expect[] field; we can ignore
 899                  * transport->smart_options->cas altogether and instead
 900                  * can enumerate them from the refs.
 901                  */
 902                 if (ref->expect_old_sha1) {
 903                         struct strbuf cas = STRBUF_INIT;
 904                         strbuf_addf(&cas, "%s:%s",
 905                                     ref->name, oid_to_hex(&ref->old_oid_expect));
 906                         string_list_append_nodup(&cas_options,
 907                                                  strbuf_detach(&cas, NULL));
 908                 }
 909         }
 910         if (buf.len == 0) {
 911                 string_list_clear(&cas_options, 0);
 912                 return 0;
 913         }
 914
 915         for_each_string_list_item(cas_option, &cas_options)
 916                 set_helper_option(transport, "cas", cas_option->string);
 917         set_common_push_options(transport, data->name, flags);
 918
 919         strbuf_addch(&buf, '\n');
 920         sendline(data, &buf);
 921         strbuf_release(&buf);
 922         string_list_clear(&cas_options, 0);
 923
 924         return push_update_refs_status(data, remote_refs, flags);
 925 }
 926
 927 static int push_refs_with_export(struct transport *transport,
 928                 struct ref *remote_refs, int flags)
 929 {
 930         struct ref *ref;
 931         struct child_process *helper, exporter;
 932         struct helper_data *data = transport->data;
 933         struct string_list revlist_args = STRING_LIST_INIT_DUP;
 934         struct strbuf buf = STRBUF_INIT;
 935
 936         if (!data->refspecs)
 937                 die("remote-helper doesn't support push; refspec needed");
 938
 939         set_common_push_options(transport, data->name, flags);
 940         if (flags & TRANSPORT_PUSH_FORCE) {
 941                 if (set_helper_option(transport, "force", "true") != 0)
 942                         warning("helper %s does not support 'force'", data->name);
 943         }
 944
 945         helper = get_helper(transport);
 946
 947         write_constant(helper->in, "export\n");
 948
 949         for (ref = remote_refs; ref; ref = ref->next) {
 950                 char *private;
 951                 struct object_id oid;
 952
 953                 private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
 954                 if (private && !get_oid(private, &oid)) {
 955                         strbuf_addf(&buf, "^%s", private);
 956                         string_list_append_nodup(&revlist_args,
 957                                                  strbuf_detach(&buf, NULL));
 958                         oidcpy(&ref->old_oid, &oid);
 959                 }
 960                 free(private);
 961
 962                 if (ref->peer_ref) {
 963                         if (strcmp(ref->name, ref->peer_ref->name)) {
 964                                 if (!ref->deletion) {
 965                                         const char *name;
 966                                         int flag;
 967
 968                                         /* Follow symbolic refs (mainly for HEAD). */
 969                                         name = resolve_ref_unsafe(ref->peer_ref->name,
 970                                                                   RESOLVE_REF_READING,
 971                                                                   &oid, &flag);
 972                                         if (!name || !(flag & REF_ISSYMREF))
 973                                                 name = ref->peer_ref->name;
 974
 975                                         strbuf_addf(&buf, "%s:%s", name, ref->name);
 976                                 } else
 977                                         strbuf_addf(&buf, ":%s", ref->name);
 978
 979                                 string_list_append(&revlist_args, "--refspec");
 980                                 string_list_append(&revlist_args, buf.buf);
 981                                 strbuf_release(&buf);
 982                         }
 983                         if (!ref->deletion)
 984                                 string_list_append(&revlist_args, ref->peer_ref->name);
 985                 }
 986         }
 987
 988         if (get_exporter(transport, &exporter, &revlist_args))
 989                 die("Couldn't run fast-export");
 990
 991         string_list_clear(&revlist_args, 1);
 992
 993         if (finish_command(&exporter))
 994                 die("Error while running fast-export");
 995         if (push_update_refs_status(data, remote_refs, flags))
 996                 return 1;
 997
 998         if (data->export_marks) {
 999                 strbuf_addf(&buf, "%s.tmp", data->export_marks);
1000                 rename(buf.buf, data->export_marks);
1001                 strbuf_release(&buf);
1002         }
1003
1004         return 0;
1005 }
1006
1007 static int push_refs(struct transport *transport,
1008                 struct ref *remote_refs, int flags)
1009 {
1010         struct helper_data *data = transport->data;
1011
1012         if (process_connect(transport, 1)) {
1013                 do_take_over(transport);
1014                 return transport->vtable->push_refs(transport, remote_refs, flags);
1015         }
1016
1017         if (!remote_refs) {
1018                 fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
1019                         "Perhaps you should specify a branch such as 'master'.\n");
1020                 return 0;
1021         }
1022
1023         if (data->push)
1024                 return push_refs_with_push(transport, remote_refs, flags);
1025
1026         if (data->export)
1027                 return push_refs_with_export(transport, remote_refs, flags);
1028
1029         return -1;
1030 }
1031
1032
1033 static int has_attribute(const char *attrs, const char *attr) {
1034         int len;
1035         if (!attrs)
1036                 return 0;
1037
1038         len = strlen(attr);
1039         for (;;) {
1040                 const char *space = strchrnul(attrs, ' ');
1041                 if (len == space - attrs && !strncmp(attrs, attr, len))
1042                         return 1;
1043                 if (!*space)
1044                         return 0;
1045                 attrs = space + 1;
1046         }
1047 }
1048
1049 static struct ref *get_refs_list(struct transport *transport, int for_push,
1050                                  const struct argv_array *ref_prefixes)
1051 {
1052         struct helper_data *data = transport->data;
1053         struct child_process *helper;
1054         struct ref *ret = NULL;
1055         struct ref **tail = &ret;
1056         struct ref *posn;
1057         struct strbuf buf = STRBUF_INIT;
1058
1059         helper = get_helper(transport);
1060
1061         if (process_connect(transport, for_push)) {
1062                 do_take_over(transport);
1063                 return transport->vtable->get_refs_list(transport, for_push, ref_prefixes);
1064         }
1065
1066         if (data->push && for_push)
1067                 write_str_in_full(helper->in, "list for-push\n");
1068         else
1069                 write_str_in_full(helper->in, "list\n");
1070
1071         while (1) {
1072                 char *eov, *eon;
1073                 if (recvline(data, &buf))
1074                         exit(128);
1075
1076                 if (!*buf.buf)
1077                         break;
1078
1079                 eov = strchr(buf.buf, ' ');
1080                 if (!eov)
1081                         die("Malformed response in ref list: %s", buf.buf);
1082                 eon = strchr(eov + 1, ' ');
1083                 *eov = '\0';
1084                 if (eon)
1085                         *eon = '\0';
1086                 *tail = alloc_ref(eov + 1);
1087                 if (buf.buf[0] == '@')
1088                         (*tail)->symref = xstrdup(buf.buf + 1);
1089                 else if (buf.buf[0] != '?')
1090                         get_oid_hex(buf.buf, &(*tail)->old_oid);
1091                 if (eon) {
1092                         if (has_attribute(eon + 1, "unchanged")) {
1093                                 (*tail)->status |= REF_STATUS_UPTODATE;
1094                                 if (read_ref((*tail)->name, &(*tail)->old_oid) < 0)
1095                                         die(_("Could not read ref %s"),
1096                                             (*tail)->name);
1097                         }
1098                 }
1099                 tail = &((*tail)->next);
1100         }
1101         if (debug)
1102                 fprintf(stderr, "Debug: Read ref listing.\n");
1103         strbuf_release(&buf);
1104
1105         for (posn = ret; posn; posn = posn->next)
1106                 resolve_remote_symref(posn, ret);
1107
1108         return ret;
1109 }
1110
1111 static struct transport_vtable vtable = {
1112         set_helper_option,
1113         get_refs_list,
1114         fetch,
1115         push_refs,
1116         connect_helper,
1117         release_helper
1118 };
1119
1120 int transport_helper_init(struct transport *transport, const char *name)
1121 {
1122         struct helper_data *data = xcalloc(1, sizeof(*data));
1123         data->name = name;
1124
1125         transport_check_allowed(name);
1126
1127         if (getenv("GIT_TRANSPORT_HELPER_DEBUG"))
1128                 debug = 1;
1129
1130         transport->data = data;
1131         transport->vtable = &vtable;
1132         transport->smart_options = &(data->transport_options);
1133         return 0;
1134 }
1135
1136 /*
1137  * Linux pipes can buffer 65536 bytes at once (and most platforms can
1138  * buffer less), so attempt reads and writes with up to that size.
1139  */
1140 #define BUFFERSIZE 65536
1141 /* This should be enough to hold debugging message. */
1142 #define PBUFFERSIZE 8192
1143
1144 /* Print bidirectional transfer loop debug message. */
1145 __attribute__((format (printf, 1, 2)))
1146 static void transfer_debug(const char *fmt, ...)
1147 {
1148         /*
1149          * NEEDSWORK: This function is sometimes used from multiple threads, and
1150          * we end up using debug_enabled racily. That "should not matter" since
1151          * we always write the same value, but it's still wrong. This function
1152          * is listed in .tsan-suppressions for the time being.
1153          */
1154
1155         va_list args;
1156         char msgbuf[PBUFFERSIZE];
1157         static int debug_enabled = -1;
1158
1159         if (debug_enabled < 0)
1160                 debug_enabled = getenv("GIT_TRANSLOOP_DEBUG") ? 1 : 0;
1161         if (!debug_enabled)
1162                 return;
1163
1164         va_start(args, fmt);
1165         vsnprintf(msgbuf, PBUFFERSIZE, fmt, args);
1166         va_end(args);
1167         fprintf(stderr, "Transfer loop debugging: %s\n", msgbuf);
1168 }
1169
1170 /* Stream state: More data may be coming in this direction. */
1171 #define SSTATE_TRANSFERRING 0
1172 /*
1173  * Stream state: No more data coming in this direction, flushing rest of
1174  * data.
1175  */
1176 #define SSTATE_FLUSHING 1
1177 /* Stream state: Transfer in this direction finished. */
1178 #define SSTATE_FINISHED 2
1179
1180 #define STATE_NEEDS_READING(state) ((state) <= SSTATE_TRANSFERRING)
1181 #define STATE_NEEDS_WRITING(state) ((state) <= SSTATE_FLUSHING)
1182 #define STATE_NEEDS_CLOSING(state) ((state) == SSTATE_FLUSHING)
1183
1184 /* Unidirectional transfer. */
1185 struct unidirectional_transfer {
1186         /* Source */
1187         int src;
1188         /* Destination */
1189         int dest;
1190         /* Is source socket? */
1191         int src_is_sock;
1192         /* Is destination socket? */
1193         int dest_is_sock;
1194         /* Transfer state (TRANSFERRING/FLUSHING/FINISHED) */
1195         int state;
1196         /* Buffer. */
1197         char buf[BUFFERSIZE];
1198         /* Buffer used. */
1199         size_t bufuse;
1200         /* Name of source. */
1201         const char *src_name;
1202         /* Name of destination. */
1203         const char *dest_name;
1204 };
1205
1206 /* Closes the target (for writing) if transfer has finished. */
1207 static void udt_close_if_finished(struct unidirectional_transfer *t)
1208 {
1209         if (STATE_NEEDS_CLOSING(t->state) && !t->bufuse) {
1210                 t->state = SSTATE_FINISHED;
1211                 if (t->dest_is_sock)
1212                         shutdown(t->dest, SHUT_WR);
1213                 else
1214                         close(t->dest);
1215                 transfer_debug("Closed %s.", t->dest_name);
1216         }
1217 }
1218
1219 /*
1220  * Tries to read data from source into buffer. If buffer is full,
1221  * no data is read. Returns 0 on success, -1 on error.
1222  */
1223 static int udt_do_read(struct unidirectional_transfer *t)
1224 {
1225         ssize_t bytes;
1226
1227         if (t->bufuse == BUFFERSIZE)
1228                 return 0;       /* No space for more. */
1229
1230         transfer_debug("%s is readable", t->src_name);
1231         bytes = read(t->src, t->buf + t->bufuse, BUFFERSIZE - t->bufuse);
1232         if (bytes < 0 && errno != EWOULDBLOCK && errno != EAGAIN &&
1233                 errno != EINTR) {
1234                 error_errno("read(%s) failed", t->src_name);
1235                 return -1;
1236         } else if (bytes == 0) {
1237                 transfer_debug("%s EOF (with %i bytes in buffer)",
1238                         t->src_name, (int)t->bufuse);
1239                 t->state = SSTATE_FLUSHING;
1240         } else if (bytes > 0) {
1241                 t->bufuse += bytes;
1242                 transfer_debug("Read %i bytes from %s (buffer now at %i)",
1243                         (int)bytes, t->src_name, (int)t->bufuse);
1244         }
1245         return 0;
1246 }
1247
1248 /* Tries to write data from buffer into destination. If buffer is empty,
1249  * no data is written. Returns 0 on success, -1 on error.
1250  */
1251 static int udt_do_write(struct unidirectional_transfer *t)
1252 {
1253         ssize_t bytes;
1254
1255         if (t->bufuse == 0)
1256                 return 0;       /* Nothing to write. */
1257
1258         transfer_debug("%s is writable", t->dest_name);
1259         bytes = xwrite(t->dest, t->buf, t->bufuse);
1260         if (bytes < 0 && errno != EWOULDBLOCK) {
1261                 error_errno("write(%s) failed", t->dest_name);
1262                 return -1;
1263         } else if (bytes > 0) {
1264                 t->bufuse -= bytes;
1265                 if (t->bufuse)
1266                         memmove(t->buf, t->buf + bytes, t->bufuse);
1267                 transfer_debug("Wrote %i bytes to %s (buffer now at %i)",
1268                         (int)bytes, t->dest_name, (int)t->bufuse);
1269         }
1270         return 0;
1271 }
1272
1273
1274 /* State of bidirectional transfer loop. */
1275 struct bidirectional_transfer_state {
1276         /* Direction from program to git. */
1277         struct unidirectional_transfer ptg;
1278         /* Direction from git to program. */
1279         struct unidirectional_transfer gtp;
1280 };
1281
1282 static void *udt_copy_task_routine(void *udt)
1283 {
1284         struct unidirectional_transfer *t = (struct unidirectional_transfer *)udt;
1285         while (t->state != SSTATE_FINISHED) {
1286                 if (STATE_NEEDS_READING(t->state))
1287                         if (udt_do_read(t))
1288                                 return NULL;
1289                 if (STATE_NEEDS_WRITING(t->state))
1290                         if (udt_do_write(t))
1291                                 return NULL;
1292                 if (STATE_NEEDS_CLOSING(t->state))
1293                         udt_close_if_finished(t);
1294         }
1295         return udt;     /* Just some non-NULL value. */
1296 }
1297
1298 #ifndef NO_PTHREADS
1299
1300 /*
1301  * Join thread, with appropriate errors on failure. Name is name for the
1302  * thread (for error messages). Returns 0 on success, 1 on failure.
1303  */
1304 static int tloop_join(pthread_t thread, const char *name)
1305 {
1306         int err;
1307         void *tret;
1308         err = pthread_join(thread, &tret);
1309         if (!tret) {
1310                 error("%s thread failed", name);
1311                 return 1;
1312         }
1313         if (err) {
1314                 error("%s thread failed to join: %s", name, strerror(err));
1315                 return 1;
1316         }
1317         return 0;
1318 }
1319
1320 /*
1321  * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1322  * -1 on failure.
1323  */
1324 static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1325 {
1326         pthread_t gtp_thread;
1327         pthread_t ptg_thread;
1328         int err;
1329         int ret = 0;
1330         err = pthread_create(&gtp_thread, NULL, udt_copy_task_routine,
1331                 &s->gtp);
1332         if (err)
1333                 die("Can't start thread for copying data: %s", strerror(err));
1334         err = pthread_create(&ptg_thread, NULL, udt_copy_task_routine,
1335                 &s->ptg);
1336         if (err)
1337                 die("Can't start thread for copying data: %s", strerror(err));
1338
1339         ret |= tloop_join(gtp_thread, "Git to program copy");
1340         ret |= tloop_join(ptg_thread, "Program to git copy");
1341         return ret;
1342 }
1343 #else
1344
1345 /* Close the source and target (for writing) for transfer. */
1346 static void udt_kill_transfer(struct unidirectional_transfer *t)
1347 {
1348         t->state = SSTATE_FINISHED;
1349         /*
1350          * Socket read end left open isn't a disaster if nobody
1351          * attempts to read from it (mingw compat headers do not
1352          * have SHUT_RD)...
1353          *
1354          * We can't fully close the socket since otherwise gtp
1355          * task would first close the socket it sends data to
1356          * while closing the ptg file descriptors.
1357          */
1358         if (!t->src_is_sock)
1359                 close(t->src);
1360         if (t->dest_is_sock)
1361                 shutdown(t->dest, SHUT_WR);
1362         else
1363                 close(t->dest);
1364 }
1365
1366 /*
1367  * Join process, with appropriate errors on failure. Name is name for the
1368  * process (for error messages). Returns 0 on success, 1 on failure.
1369  */
1370 static int tloop_join(pid_t pid, const char *name)
1371 {
1372         int tret;
1373         if (waitpid(pid, &tret, 0) < 0) {
1374                 error_errno("%s process failed to wait", name);
1375                 return 1;
1376         }
1377         if (!WIFEXITED(tret) || WEXITSTATUS(tret)) {
1378                 error("%s process failed", name);
1379                 return 1;
1380         }
1381         return 0;
1382 }
1383
1384 /*
1385  * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1386  * -1 on failure.
1387  */
1388 static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1389 {
1390         pid_t pid1, pid2;
1391         int ret = 0;
1392
1393         /* Fork thread #1: git to program. */
1394         pid1 = fork();
1395         if (pid1 < 0)
1396                 die_errno("Can't start thread for copying data");
1397         else if (pid1 == 0) {
1398                 udt_kill_transfer(&s->ptg);
1399                 exit(udt_copy_task_routine(&s->gtp) ? 0 : 1);
1400         }
1401
1402         /* Fork thread #2: program to git. */
1403         pid2 = fork();
1404         if (pid2 < 0)
1405                 die_errno("Can't start thread for copying data");
1406         else if (pid2 == 0) {
1407                 udt_kill_transfer(&s->gtp);
1408                 exit(udt_copy_task_routine(&s->ptg) ? 0 : 1);
1409         }
1410
1411         /*
1412          * Close both streams in parent as to not interfere with
1413          * end of file detection and wait for both tasks to finish.
1414          */
1415         udt_kill_transfer(&s->gtp);
1416         udt_kill_transfer(&s->ptg);
1417         ret |= tloop_join(pid1, "Git to program copy");
1418         ret |= tloop_join(pid2, "Program to git copy");
1419         return ret;
1420 }
1421 #endif
1422
1423 /*
1424  * Copies data from stdin to output and from input to stdout simultaneously.
1425  * Additionally filtering through given filter. If filter is NULL, uses
1426  * identity filter.
1427  */
1428 int bidirectional_transfer_loop(int input, int output)
1429 {
1430         struct bidirectional_transfer_state state;
1431
1432         /* Fill the state fields. */
1433         state.ptg.src = input;
1434         state.ptg.dest = 1;
1435         state.ptg.src_is_sock = (input == output);
1436         state.ptg.dest_is_sock = 0;
1437         state.ptg.state = SSTATE_TRANSFERRING;
1438         state.ptg.bufuse = 0;
1439         state.ptg.src_name = "remote input";
1440         state.ptg.dest_name = "stdout";
1441
1442         state.gtp.src = 0;
1443         state.gtp.dest = output;
1444         state.gtp.src_is_sock = 0;
1445         state.gtp.dest_is_sock = (input == output);
1446         state.gtp.state = SSTATE_TRANSFERRING;
1447         state.gtp.bufuse = 0;
1448         state.gtp.src_name = "stdin";
1449         state.gtp.dest_name = "remote output";
1450
1451         return tloop_spawnwait_tasks(&state);
1452 }