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
  16 static int debug;
  17
  18 struct helper_data {
  19         const char *name;
  20         struct child_process *helper;
  21         FILE *out;
  22         unsigned fetch : 1,
  23                 import : 1,
  24                 bidi_import : 1,
  25                 export : 1,
  26                 option : 1,
  27                 push : 1,
  28                 connect : 1,
  29                 stateless_connect : 1,
  30                 signed_tags : 1,
  31                 check_connectivity : 1,
  32                 no_disconnect_req : 1,
  33                 no_private_update : 1;
  34         char *export_marks;
  35         char *import_marks;
  36         /* These go from remote name (as in "list") to private name */
  37         struct refspec *refspecs;
  38         int refspec_nr;
  39         /* Transport options for fetch-pack/send-pack (should one of
  40          * those be invoked).
  41          */
  42         struct git_transport_options transport_options;
  43 };
  44
  45 static void sendline(struct helper_data *helper, struct strbuf *buffer)
  46 {
  47         if (debug)
  48                 fprintf(stderr, "Debug: Remote helper: -> %s", buffer->buf);
  49         if (write_in_full(helper->helper->in, buffer->buf, buffer->len) < 0)
  50                 die_errno("Full write to remote helper failed");
  51 }
  52
  53 static int recvline_fh(FILE *helper, struct strbuf *buffer)
  54 {
  55         strbuf_reset(buffer);
  56         if (debug)
  57                 fprintf(stderr, "Debug: Remote helper: Waiting...\n");
  58         if (strbuf_getline(buffer, helper) == EOF) {
  59                 if (debug)
  60                         fprintf(stderr, "Debug: Remote helper quit.\n");
  61                 return 1;
  62         }
  63
  64         if (debug)
  65                 fprintf(stderr, "Debug: Remote helper: <- %s\n", buffer->buf);
  66         return 0;
  67 }
  68
  69 static int recvline(struct helper_data *helper, struct strbuf *buffer)
  70 {
  71         return recvline_fh(helper->out, buffer);
  72 }
  73
  74 static void write_constant(int fd, const char *str)
  75 {
  76         if (debug)
  77                 fprintf(stderr, "Debug: Remote helper: -> %s", str);
  78         if (write_in_full(fd, str, strlen(str)) < 0)
  79                 die_errno("Full write to remote helper failed");
  80 }
  81
  82 static const char *remove_ext_force(const char *url)
  83 {
  84         if (url) {
  85                 const char *colon = strchr(url, ':');
  86                 if (colon && colon[1] == ':')
  87                         return colon + 2;
  88         }
  89         return url;
  90 }
  91
  92 static void do_take_over(struct transport *transport)
  93 {
  94         struct helper_data *data;
  95         data = (struct helper_data *)transport->data;
  96         transport_take_over(transport, data->helper);
  97         fclose(data->out);
  98         free(data);
  99 }
 100
 101 static void standard_options(struct transport *t);
 102
 103 static struct child_process *get_helper(struct transport *transport)
 104 {
 105         struct helper_data *data = transport->data;
 106         struct strbuf buf = STRBUF_INIT;
 107         struct child_process *helper;
 108         const char **refspecs = NULL;
 109         int refspec_nr = 0;
 110         int refspec_alloc = 0;
 111         int duped;
 112         int code;
 113
 114         if (data->helper)
 115                 return data->helper;
 116
 117         helper = xmalloc(sizeof(*helper));
 118         child_process_init(helper);
 119         helper->in = -1;
 120         helper->out = -1;
 121         helper->err = 0;
 122         argv_array_pushf(&helper->args, "git-remote-%s", data->name);
 123         argv_array_push(&helper->args, transport->remote->name);
 124         argv_array_push(&helper->args, remove_ext_force(transport->url));
 125         helper->git_cmd = 0;
 126         helper->silent_exec_failure = 1;
 127
 128         if (have_git_dir())
 129                 argv_array_pushf(&helper->env_array, "%s=%s",
 130                                  GIT_DIR_ENVIRONMENT, get_git_dir());
 131
 132         code = start_command(helper);
 133         if (code < 0 && errno == ENOENT)
 134                 die("Unable to find remote helper for '%s'", data->name);
 135         else if (code != 0)
 136                 exit(code);
 137
 138         data->helper = helper;
 139         data->no_disconnect_req = 0;
 140
 141         /*
 142          * Open the output as FILE* so strbuf_getline_*() family of
 143          * functions can be used.
 144          * Do this with duped fd because fclose() will close the fd,
 145          * and stuff like taking over will require the fd to remain.
 146          */
 147         duped = dup(helper->out);
 148         if (duped < 0)
 149                 die_errno("Can't dup helper output fd");
 150         data->out = xfdopen(duped, "r");
 151
 152         write_constant(helper->in, "capabilities\n");
 153
 154         while (1) {
 155                 const char *capname, *arg;
 156                 int mandatory = 0;
 157                 if (recvline(data, &buf))
 158                         exit(128);
 159
 160                 if (!*buf.buf)
 161                         break;
 162
 163                 if (*buf.buf == '*') {
 164                         capname = buf.buf + 1;
 165                         mandatory = 1;
 166                 } else
 167                         capname = buf.buf;
 168
 169                 if (debug)
 170                         fprintf(stderr, "Debug: Got cap %s\n", capname);
 171                 if (!strcmp(capname, "fetch"))
 172                         data->fetch = 1;
 173                 else if (!strcmp(capname, "option"))
 174                         data->option = 1;
 175                 else if (!strcmp(capname, "push"))
 176                         data->push = 1;
 177                 else if (!strcmp(capname, "import"))
 178                         data->import = 1;
 179                 else if (!strcmp(capname, "bidi-import"))
 180                         data->bidi_import = 1;
 181                 else if (!strcmp(capname, "export"))
 182                         data->export = 1;
 183                 else if (!strcmp(capname, "check-connectivity"))
 184                         data->check_connectivity = 1;
 185                 else if (!data->refspecs && skip_prefix(capname, "refspec ", &arg)) {
 186                         ALLOC_GROW(refspecs,
 187                                    refspec_nr + 1,
 188                                    refspec_alloc);
 189                         refspecs[refspec_nr++] = xstrdup(arg);
 190                 } else if (!strcmp(capname, "connect")) {
 191                         data->connect = 1;
 192                 } else if (!strcmp(capname, "stateless-connect")) {
 193                         data->stateless_connect = 1;
 194                 } else if (!strcmp(capname, "signed-tags")) {
 195                         data->signed_tags = 1;
 196                 } else if (skip_prefix(capname, "export-marks ", &arg)) {
 197                         data->export_marks = xstrdup(arg);
 198                 } else if (skip_prefix(capname, "import-marks ", &arg)) {
 199                         data->import_marks = xstrdup(arg);
 200                 } else if (starts_with(capname, "no-private-update")) {
 201                         data->no_private_update = 1;
 202                 } else if (mandatory) {
 203                         die("Unknown mandatory capability %s. This remote "
 204                             "helper probably needs newer version of Git.",
 205                             capname);
 206                 }
 207         }
 208         if (refspecs) {
 209                 int i;
 210                 data->refspec_nr = refspec_nr;
 211                 data->refspecs = parse_fetch_refspec(refspec_nr, refspecs);
 212                 for (i = 0; i < refspec_nr; i++)
 213                         free((char *)refspecs[i]);
 214                 free(refspecs);
 215         } else if (data->import || data->bidi_import || data->export) {
 216                 warning("This remote helper should implement refspec capability.");
 217         }
 218         strbuf_release(&buf);
 219         if (debug)
 220                 fprintf(stderr, "Debug: Capabilities complete.\n");
 221         standard_options(transport);
 222         return data->helper;
 223 }
 224
 225 static int disconnect_helper(struct transport *transport)
 226 {
 227         struct helper_data *data = transport->data;
 228         int res = 0;
 229
 230         if (data->helper) {
 231                 if (debug)
 232                         fprintf(stderr, "Debug: Disconnecting.\n");
 233                 if (!data->no_disconnect_req) {
 234                         /*
 235                          * Ignore write errors; there's nothing we can do,
 236                          * since we're about to close the pipe anyway. And the
 237                          * most likely error is EPIPE due to the helper dying
 238                          * to report an error itself.
 239                          */
 240                         sigchain_push(SIGPIPE, SIG_IGN);
 241                         xwrite(data->helper->in, "\n", 1);
 242                         sigchain_pop(SIGPIPE);
 243                 }
 244                 close(data->helper->in);
 245                 close(data->helper->out);
 246                 fclose(data->out);
 247                 res = finish_command(data->helper);
 248                 FREE_AND_NULL(data->helper);
 249         }
 250         return res;
 251 }
 252
 253 static const char *unsupported_options[] = {
 254         TRANS_OPT_UPLOADPACK,
 255         TRANS_OPT_RECEIVEPACK,
 256         TRANS_OPT_THIN,
 257         TRANS_OPT_KEEP
 258         };
 259
 260 static const char *boolean_options[] = {
 261         TRANS_OPT_THIN,
 262         TRANS_OPT_KEEP,
 263         TRANS_OPT_FOLLOWTAGS,
 264         TRANS_OPT_DEEPEN_RELATIVE
 265         };
 266
 267 static int strbuf_set_helper_option(struct helper_data *data,
 268                                     struct strbuf *buf)
 269 {
 270         int ret;
 271
 272         sendline(data, buf);
 273         if (recvline(data, buf))
 274                 exit(128);
 275
 276         if (!strcmp(buf->buf, "ok"))
 277                 ret = 0;
 278         else if (starts_with(buf->buf, "error"))
 279                 ret = -1;
 280         else if (!strcmp(buf->buf, "unsupported"))
 281                 ret = 1;
 282         else {
 283                 warning("%s unexpectedly said: '%s'", data->name, buf->buf);
 284                 ret = 1;
 285         }
 286         return ret;
 287 }
 288
 289 static int string_list_set_helper_option(struct helper_data *data,
 290                                          const char *name,
 291                                          struct string_list *list)
 292 {
 293         struct strbuf buf = STRBUF_INIT;
 294         int i, ret = 0;
 295
 296         for (i = 0; i < list->nr; i++) {
 297                 strbuf_addf(&buf, "option %s ", name);
 298                 quote_c_style(list->items[i].string, &buf, NULL, 0);
 299                 strbuf_addch(&buf, '\n');
 300
 301                 if ((ret = strbuf_set_helper_option(data, &buf)))
 302                         break;
 303                 strbuf_reset(&buf);
 304         }
 305         strbuf_release(&buf);
 306         return ret;
 307 }
 308
 309 static int set_helper_option(struct transport *transport,
 310                           const char *name, const char *value)
 311 {
 312         struct helper_data *data = transport->data;
 313         struct strbuf buf = STRBUF_INIT;
 314         int i, ret, is_bool = 0;
 315
 316         get_helper(transport);
 317
 318         if (!data->option)
 319                 return 1;
 320
 321         if (!strcmp(name, "deepen-not"))
 322                 return string_list_set_helper_option(data, name,
 323                                                      (struct string_list *)value);
 324
 325         for (i = 0; i < ARRAY_SIZE(unsupported_options); i++) {
 326                 if (!strcmp(name, unsupported_options[i]))
 327                         return 1;
 328         }
 329
 330         for (i = 0; i < ARRAY_SIZE(boolean_options); i++) {
 331                 if (!strcmp(name, boolean_options[i])) {
 332                         is_bool = 1;
 333                         break;
 334                 }
 335         }
 336
 337         strbuf_addf(&buf, "option %s ", name);
 338         if (is_bool)
 339                 strbuf_addstr(&buf, value ? "true" : "false");
 340         else
 341                 quote_c_style(value, &buf, NULL, 0);
 342         strbuf_addch(&buf, '\n');
 343
 344         ret = strbuf_set_helper_option(data, &buf);
 345         strbuf_release(&buf);
 346         return ret;
 347 }
 348
 349 static void standard_options(struct transport *t)
 350 {
 351         char buf[16];
 352         int v = t->verbose;
 353
 354         set_helper_option(t, "progress", t->progress ? "true" : "false");
 355
 356         xsnprintf(buf, sizeof(buf), "%d", v + 1);
 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) < 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 run_connect(struct transport *transport, struct strbuf *cmdbuf)
 552 {
 553         struct helper_data *data = transport->data;
 554         int ret = 0;
 555         int duped;
 556         FILE *input;
 557         struct child_process *helper;
 558
 559         helper = get_helper(transport);
 560
 561         /*
 562          * Yes, dup the pipe another time, as we need unbuffered version
 563          * of input pipe as FILE*. fclose() closes the underlying fd and
 564          * stream buffering only can be changed before first I/O operation
 565          * on it.
 566          */
 567         duped = dup(helper->out);
 568         if (duped < 0)
 569                 die_errno("Can't dup helper output fd");
 570         input = xfdopen(duped, "r");
 571         setvbuf(input, NULL, _IONBF, 0);
 572
 573         sendline(data, cmdbuf);
 574         if (recvline_fh(input, cmdbuf))
 575                 exit(128);
 576
 577         if (!strcmp(cmdbuf->buf, "")) {
 578                 data->no_disconnect_req = 1;
 579                 if (debug)
 580                         fprintf(stderr, "Debug: Smart transport connection "
 581                                 "ready.\n");
 582                 ret = 1;
 583         } else if (!strcmp(cmdbuf->buf, "fallback")) {
 584                 if (debug)
 585                         fprintf(stderr, "Debug: Falling back to dumb "
 586                                 "transport.\n");
 587         } else {
 588                 die("Unknown response to connect: %s",
 589                         cmdbuf->buf);
 590         }
 591
 592         fclose(input);
 593         return ret;
 594 }
 595
 596 static int process_connect_service(struct transport *transport,
 597                                    const char *name, const char *exec)
 598 {
 599         struct helper_data *data = transport->data;
 600         struct strbuf cmdbuf = STRBUF_INIT;
 601         int ret = 0;
 602
 603         /*
 604          * Handle --upload-pack and friends. This is fire and forget...
 605          * just warn if it fails.
 606          */
 607         if (strcmp(name, exec)) {
 608                 int r = set_helper_option(transport, "servpath", exec);
 609                 if (r > 0)
 610                         warning("Setting remote service path not supported by protocol.");
 611                 else if (r < 0)
 612                         warning("Invalid remote service path.");
 613         }
 614
 615         if (data->connect) {
 616                 strbuf_addf(&cmdbuf, "connect %s\n", name);
 617                 ret = run_connect(transport, &cmdbuf);
 618         } else if (data->stateless_connect) {
 619                 strbuf_addf(&cmdbuf, "stateless-connect %s\n", name);
 620                 ret = run_connect(transport, &cmdbuf);
 621                 if (ret)
 622                         transport->stateless_rpc = 1;
 623         }
 624
 625         strbuf_release(&cmdbuf);
 626         return ret;
 627 }
 628
 629 static int process_connect(struct transport *transport,
 630                                      int for_push)
 631 {
 632         struct helper_data *data = transport->data;
 633         const char *name;
 634         const char *exec;
 635
 636         name = for_push ? "git-receive-pack" : "git-upload-pack";
 637         if (for_push)
 638                 exec = data->transport_options.receivepack;
 639         else
 640                 exec = data->transport_options.uploadpack;
 641
 642         return process_connect_service(transport, name, exec);
 643 }
 644
 645 static int connect_helper(struct transport *transport, const char *name,
 646                    const char *exec, int fd[2])
 647 {
 648         struct helper_data *data = transport->data;
 649
 650         /* Get_helper so connect is inited. */
 651         get_helper(transport);
 652         if (!data->connect)
 653                 die("Operation not supported by protocol.");
 654
 655         if (!process_connect_service(transport, name, exec))
 656                 die("Can't connect to subservice %s.", name);
 657
 658         fd[0] = data->helper->out;
 659         fd[1] = data->helper->in;
 660         return 0;
 661 }
 662
 663 static int fetch(struct transport *transport,
 664                  int nr_heads, struct ref **to_fetch)
 665 {
 666         struct helper_data *data = transport->data;
 667         int i, count;
 668
 669         if (process_connect(transport, 0)) {
 670                 do_take_over(transport);
 671                 return transport->vtable->fetch(transport, nr_heads, to_fetch);
 672         }
 673
 674         count = 0;
 675         for (i = 0; i < nr_heads; i++)
 676                 if (!(to_fetch[i]->status & REF_STATUS_UPTODATE))
 677                         count++;
 678
 679         if (!count)
 680                 return 0;
 681
 682         if (data->check_connectivity &&
 683             data->transport_options.check_self_contained_and_connected)
 684                 set_helper_option(transport, "check-connectivity", "true");
 685
 686         if (transport->cloning)
 687                 set_helper_option(transport, "cloning", "true");
 688
 689         if (data->transport_options.update_shallow)
 690                 set_helper_option(transport, "update-shallow", "true");
 691
 692         if (data->transport_options.filter_options.choice)
 693                 set_helper_option(
 694                         transport, "filter",
 695                         data->transport_options.filter_options.filter_spec);
 696
 697         if (data->fetch)
 698                 return fetch_with_fetch(transport, nr_heads, to_fetch);
 699
 700         if (data->import)
 701                 return fetch_with_import(transport, nr_heads, to_fetch);
 702
 703         return -1;
 704 }
 705
 706 static int push_update_ref_status(struct strbuf *buf,
 707                                    struct ref **ref,
 708                                    struct ref *remote_refs)
 709 {
 710         char *refname, *msg;
 711         int status, forced = 0;
 712
 713         if (starts_with(buf->buf, "ok ")) {
 714                 status = REF_STATUS_OK;
 715                 refname = buf->buf + 3;
 716         } else if (starts_with(buf->buf, "error ")) {
 717                 status = REF_STATUS_REMOTE_REJECT;
 718                 refname = buf->buf + 6;
 719         } else
 720                 die("expected ok/error, helper said '%s'", buf->buf);
 721
 722         msg = strchr(refname, ' ');
 723         if (msg) {
 724                 struct strbuf msg_buf = STRBUF_INIT;
 725                 const char *end;
 726
 727                 *msg++ = '\0';
 728                 if (!unquote_c_style(&msg_buf, msg, &end))
 729                         msg = strbuf_detach(&msg_buf, NULL);
 730                 else
 731                         msg = xstrdup(msg);
 732                 strbuf_release(&msg_buf);
 733
 734                 if (!strcmp(msg, "no match")) {
 735                         status = REF_STATUS_NONE;
 736                         FREE_AND_NULL(msg);
 737                 }
 738                 else if (!strcmp(msg, "up to date")) {
 739                         status = REF_STATUS_UPTODATE;
 740                         FREE_AND_NULL(msg);
 741                 }
 742                 else if (!strcmp(msg, "non-fast forward")) {
 743                         status = REF_STATUS_REJECT_NONFASTFORWARD;
 744                         FREE_AND_NULL(msg);
 745                 }
 746                 else if (!strcmp(msg, "already exists")) {
 747                         status = REF_STATUS_REJECT_ALREADY_EXISTS;
 748                         FREE_AND_NULL(msg);
 749                 }
 750                 else if (!strcmp(msg, "fetch first")) {
 751                         status = REF_STATUS_REJECT_FETCH_FIRST;
 752                         FREE_AND_NULL(msg);
 753                 }
 754                 else if (!strcmp(msg, "needs force")) {
 755                         status = REF_STATUS_REJECT_NEEDS_FORCE;
 756                         FREE_AND_NULL(msg);
 757                 }
 758                 else if (!strcmp(msg, "stale info")) {
 759                         status = REF_STATUS_REJECT_STALE;
 760                         FREE_AND_NULL(msg);
 761                 }
 762                 else if (!strcmp(msg, "forced update")) {
 763                         forced = 1;
 764                         FREE_AND_NULL(msg);
 765                 }
 766         }
 767
 768         if (*ref)
 769                 *ref = find_ref_by_name(*ref, refname);
 770         if (!*ref)
 771                 *ref = find_ref_by_name(remote_refs, refname);
 772         if (!*ref) {
 773                 warning("helper reported unexpected status of %s", refname);
 774                 return 1;
 775         }
 776
 777         if ((*ref)->status != REF_STATUS_NONE) {
 778                 /*
 779                  * Earlier, the ref was marked not to be pushed, so ignore the ref
 780                  * status reported by the remote helper if the latter is 'no match'.
 781                  */
 782                 if (status == REF_STATUS_NONE)
 783                         return 1;
 784         }
 785
 786         (*ref)->status = status;
 787         (*ref)->forced_update |= forced;
 788         (*ref)->remote_status = msg;
 789         return !(status == REF_STATUS_OK);
 790 }
 791
 792 static int push_update_refs_status(struct helper_data *data,
 793                                     struct ref *remote_refs,
 794                                     int flags)
 795 {
 796         struct strbuf buf = STRBUF_INIT;
 797         struct ref *ref = remote_refs;
 798         int ret = 0;
 799
 800         for (;;) {
 801                 char *private;
 802
 803                 if (recvline(data, &buf)) {
 804                         ret = 1;
 805                         break;
 806                 }
 807
 808                 if (!buf.len)
 809                         break;
 810
 811                 if (push_update_ref_status(&buf, &ref, remote_refs))
 812                         continue;
 813
 814                 if (flags & TRANSPORT_PUSH_DRY_RUN || !data->refspecs || data->no_private_update)
 815                         continue;
 816
 817                 /* propagate back the update to the remote namespace */
 818                 private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
 819                 if (!private)
 820                         continue;
 821                 update_ref("update by helper", private, &ref->new_oid, NULL,
 822                            0, 0);
 823                 free(private);
 824         }
 825         strbuf_release(&buf);
 826         return ret;
 827 }
 828
 829 static void set_common_push_options(struct transport *transport,
 830                                    const char *name, int flags)
 831 {
 832         if (flags & TRANSPORT_PUSH_DRY_RUN) {
 833                 if (set_helper_option(transport, "dry-run", "true") != 0)
 834                         die("helper %s does not support dry-run", name);
 835         } else if (flags & TRANSPORT_PUSH_CERT_ALWAYS) {
 836                 if (set_helper_option(transport, TRANS_OPT_PUSH_CERT, "true") != 0)
 837                         die("helper %s does not support --signed", name);
 838         } else if (flags & TRANSPORT_PUSH_CERT_IF_ASKED) {
 839                 if (set_helper_option(transport, TRANS_OPT_PUSH_CERT, "if-asked") != 0)
 840                         die("helper %s does not support --signed=if-asked", name);
 841         }
 842
 843         if (flags & TRANSPORT_PUSH_OPTIONS) {
 844                 struct string_list_item *item;
 845                 for_each_string_list_item(item, transport->push_options)
 846                         if (set_helper_option(transport, "push-option", item->string) != 0)
 847                                 die("helper %s does not support 'push-option'", name);
 848         }
 849 }
 850
 851 static int push_refs_with_push(struct transport *transport,
 852                                struct ref *remote_refs, int flags)
 853 {
 854         int force_all = flags & TRANSPORT_PUSH_FORCE;
 855         int mirror = flags & TRANSPORT_PUSH_MIRROR;
 856         struct helper_data *data = transport->data;
 857         struct strbuf buf = STRBUF_INIT;
 858         struct ref *ref;
 859         struct string_list cas_options = STRING_LIST_INIT_DUP;
 860         struct string_list_item *cas_option;
 861
 862         get_helper(transport);
 863         if (!data->push)
 864                 return 1;
 865
 866         for (ref = remote_refs; ref; ref = ref->next) {
 867                 if (!ref->peer_ref && !mirror)
 868                         continue;
 869
 870                 /* Check for statuses set by set_ref_status_for_push() */
 871                 switch (ref->status) {
 872                 case REF_STATUS_REJECT_NONFASTFORWARD:
 873                 case REF_STATUS_REJECT_STALE:
 874                 case REF_STATUS_REJECT_ALREADY_EXISTS:
 875                 case REF_STATUS_UPTODATE:
 876                         continue;
 877                 default:
 878                         ; /* do nothing */
 879                 }
 880
 881                 if (force_all)
 882                         ref->force = 1;
 883
 884                 strbuf_addstr(&buf, "push ");
 885                 if (!ref->deletion) {
 886                         if (ref->force)
 887                                 strbuf_addch(&buf, '+');
 888                         if (ref->peer_ref)
 889                                 strbuf_addstr(&buf, ref->peer_ref->name);
 890                         else
 891                                 strbuf_addstr(&buf, oid_to_hex(&ref->new_oid));
 892                 }
 893                 strbuf_addch(&buf, ':');
 894                 strbuf_addstr(&buf, ref->name);
 895                 strbuf_addch(&buf, '\n');
 896
 897                 /*
 898                  * The "--force-with-lease" options without explicit
 899                  * values to expect have already been expanded into
 900                  * the ref->old_oid_expect[] field; we can ignore
 901                  * transport->smart_options->cas altogether and instead
 902                  * can enumerate them from the refs.
 903                  */
 904                 if (ref->expect_old_sha1) {
 905                         struct strbuf cas = STRBUF_INIT;
 906                         strbuf_addf(&cas, "%s:%s",
 907                                     ref->name, oid_to_hex(&ref->old_oid_expect));
 908                         string_list_append_nodup(&cas_options,
 909                                                  strbuf_detach(&cas, NULL));
 910                 }
 911         }
 912         if (buf.len == 0) {
 913                 string_list_clear(&cas_options, 0);
 914                 return 0;
 915         }
 916
 917         for_each_string_list_item(cas_option, &cas_options)
 918                 set_helper_option(transport, "cas", cas_option->string);
 919         set_common_push_options(transport, data->name, flags);
 920
 921         strbuf_addch(&buf, '\n');
 922         sendline(data, &buf);
 923         strbuf_release(&buf);
 924         string_list_clear(&cas_options, 0);
 925
 926         return push_update_refs_status(data, remote_refs, flags);
 927 }
 928
 929 static int push_refs_with_export(struct transport *transport,
 930                 struct ref *remote_refs, int flags)
 931 {
 932         struct ref *ref;
 933         struct child_process *helper, exporter;
 934         struct helper_data *data = transport->data;
 935         struct string_list revlist_args = STRING_LIST_INIT_DUP;
 936         struct strbuf buf = STRBUF_INIT;
 937
 938         if (!data->refspecs)
 939                 die("remote-helper doesn't support push; refspec needed");
 940
 941         set_common_push_options(transport, data->name, flags);
 942         if (flags & TRANSPORT_PUSH_FORCE) {
 943                 if (set_helper_option(transport, "force", "true") != 0)
 944                         warning("helper %s does not support 'force'", data->name);
 945         }
 946
 947         helper = get_helper(transport);
 948
 949         write_constant(helper->in, "export\n");
 950
 951         for (ref = remote_refs; ref; ref = ref->next) {
 952                 char *private;
 953                 struct object_id oid;
 954
 955                 private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
 956                 if (private && !get_oid(private, &oid)) {
 957                         strbuf_addf(&buf, "^%s", private);
 958                         string_list_append_nodup(&revlist_args,
 959                                                  strbuf_detach(&buf, NULL));
 960                         oidcpy(&ref->old_oid, &oid);
 961                 }
 962                 free(private);
 963
 964                 if (ref->peer_ref) {
 965                         if (strcmp(ref->name, ref->peer_ref->name)) {
 966                                 if (!ref->deletion) {
 967                                         const char *name;
 968                                         int flag;
 969
 970                                         /* Follow symbolic refs (mainly for HEAD). */
 971                                         name = resolve_ref_unsafe(ref->peer_ref->name,
 972                                                                   RESOLVE_REF_READING,
 973                                                                   &oid, &flag);
 974                                         if (!name || !(flag & REF_ISSYMREF))
 975                                                 name = ref->peer_ref->name;
 976
 977                                         strbuf_addf(&buf, "%s:%s", name, ref->name);
 978                                 } else
 979                                         strbuf_addf(&buf, ":%s", ref->name);
 980
 981                                 string_list_append(&revlist_args, "--refspec");
 982                                 string_list_append(&revlist_args, buf.buf);
 983                                 strbuf_release(&buf);
 984                         }
 985                         if (!ref->deletion)
 986                                 string_list_append(&revlist_args, ref->peer_ref->name);
 987                 }
 988         }
 989
 990         if (get_exporter(transport, &exporter, &revlist_args))
 991                 die("Couldn't run fast-export");
 992
 993         string_list_clear(&revlist_args, 1);
 994
 995         if (finish_command(&exporter))
 996                 die("Error while running fast-export");
 997         if (push_update_refs_status(data, remote_refs, flags))
 998                 return 1;
 999
1000         if (data->export_marks) {
1001                 strbuf_addf(&buf, "%s.tmp", data->export_marks);
1002                 rename(buf.buf, data->export_marks);
1003                 strbuf_release(&buf);
1004         }
1005
1006         return 0;
1007 }
1008
1009 static int push_refs(struct transport *transport,
1010                 struct ref *remote_refs, int flags)
1011 {
1012         struct helper_data *data = transport->data;
1013
1014         if (process_connect(transport, 1)) {
1015                 do_take_over(transport);
1016                 return transport->vtable->push_refs(transport, remote_refs, flags);
1017         }
1018
1019         if (!remote_refs) {
1020                 fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
1021                         "Perhaps you should specify a branch such as 'master'.\n");
1022                 return 0;
1023         }
1024
1025         if (data->push)
1026                 return push_refs_with_push(transport, remote_refs, flags);
1027
1028         if (data->export)
1029                 return push_refs_with_export(transport, remote_refs, flags);
1030
1031         return -1;
1032 }
1033
1034
1035 static int has_attribute(const char *attrs, const char *attr) {
1036         int len;
1037         if (!attrs)
1038                 return 0;
1039
1040         len = strlen(attr);
1041         for (;;) {
1042                 const char *space = strchrnul(attrs, ' ');
1043                 if (len == space - attrs && !strncmp(attrs, attr, len))
1044                         return 1;
1045                 if (!*space)
1046                         return 0;
1047                 attrs = space + 1;
1048         }
1049 }
1050
1051 static struct ref *get_refs_list(struct transport *transport, int for_push,
1052                                  const struct argv_array *ref_patterns)
1053 {
1054         struct helper_data *data = transport->data;
1055         struct child_process *helper;
1056         struct ref *ret = NULL;
1057         struct ref **tail = &ret;
1058         struct ref *posn;
1059         struct strbuf buf = STRBUF_INIT;
1060
1061         helper = get_helper(transport);
1062
1063         if (process_connect(transport, for_push)) {
1064                 do_take_over(transport);
1065                 return transport->vtable->get_refs_list(transport, for_push, ref_patterns);
1066         }
1067
1068         if (data->push && for_push)
1069                 write_str_in_full(helper->in, "list for-push\n");
1070         else
1071                 write_str_in_full(helper->in, "list\n");
1072
1073         while (1) {
1074                 char *eov, *eon;
1075                 if (recvline(data, &buf))
1076                         exit(128);
1077
1078                 if (!*buf.buf)
1079                         break;
1080
1081                 eov = strchr(buf.buf, ' ');
1082                 if (!eov)
1083                         die("Malformed response in ref list: %s", buf.buf);
1084                 eon = strchr(eov + 1, ' ');
1085                 *eov = '\0';
1086                 if (eon)
1087                         *eon = '\0';
1088                 *tail = alloc_ref(eov + 1);
1089                 if (buf.buf[0] == '@')
1090                         (*tail)->symref = xstrdup(buf.buf + 1);
1091                 else if (buf.buf[0] != '?')
1092                         get_oid_hex(buf.buf, &(*tail)->old_oid);
1093                 if (eon) {
1094                         if (has_attribute(eon + 1, "unchanged")) {
1095                                 (*tail)->status |= REF_STATUS_UPTODATE;
1096                                 if (read_ref((*tail)->name, &(*tail)->old_oid) < 0)
1097                                         die(_("Could not read ref %s"),
1098                                             (*tail)->name);
1099                         }
1100                 }
1101                 tail = &((*tail)->next);
1102         }
1103         if (debug)
1104                 fprintf(stderr, "Debug: Read ref listing.\n");
1105         strbuf_release(&buf);
1106
1107         for (posn = ret; posn; posn = posn->next)
1108                 resolve_remote_symref(posn, ret);
1109
1110         return ret;
1111 }
1112
1113 static struct transport_vtable vtable = {
1114         set_helper_option,
1115         get_refs_list,
1116         fetch,
1117         push_refs,
1118         connect_helper,
1119         release_helper
1120 };
1121
1122 int transport_helper_init(struct transport *transport, const char *name)
1123 {
1124         struct helper_data *data = xcalloc(1, sizeof(*data));
1125         data->name = name;
1126
1127         transport_check_allowed(name);
1128
1129         if (getenv("GIT_TRANSPORT_HELPER_DEBUG"))
1130                 debug = 1;
1131
1132         transport->data = data;
1133         transport->vtable = &vtable;
1134         transport->smart_options = &(data->transport_options);
1135         return 0;
1136 }
1137
1138 /*
1139  * Linux pipes can buffer 65536 bytes at once (and most platforms can
1140  * buffer less), so attempt reads and writes with up to that size.
1141  */
1142 #define BUFFERSIZE 65536
1143 /* This should be enough to hold debugging message. */
1144 #define PBUFFERSIZE 8192
1145
1146 /* Print bidirectional transfer loop debug message. */
1147 __attribute__((format (printf, 1, 2)))
1148 static void transfer_debug(const char *fmt, ...)
1149 {
1150         /*
1151          * NEEDSWORK: This function is sometimes used from multiple threads, and
1152          * we end up using debug_enabled racily. That "should not matter" since
1153          * we always write the same value, but it's still wrong. This function
1154          * is listed in .tsan-suppressions for the time being.
1155          */
1156
1157         va_list args;
1158         char msgbuf[PBUFFERSIZE];
1159         static int debug_enabled = -1;
1160
1161         if (debug_enabled < 0)
1162                 debug_enabled = getenv("GIT_TRANSLOOP_DEBUG") ? 1 : 0;
1163         if (!debug_enabled)
1164                 return;
1165
1166         va_start(args, fmt);
1167         vsnprintf(msgbuf, PBUFFERSIZE, fmt, args);
1168         va_end(args);
1169         fprintf(stderr, "Transfer loop debugging: %s\n", msgbuf);
1170 }
1171
1172 /* Stream state: More data may be coming in this direction. */
1173 #define SSTATE_TRANSFERRING 0
1174 /*
1175  * Stream state: No more data coming in this direction, flushing rest of
1176  * data.
1177  */
1178 #define SSTATE_FLUSHING 1
1179 /* Stream state: Transfer in this direction finished. */
1180 #define SSTATE_FINISHED 2
1181
1182 #define STATE_NEEDS_READING(state) ((state) <= SSTATE_TRANSFERRING)
1183 #define STATE_NEEDS_WRITING(state) ((state) <= SSTATE_FLUSHING)
1184 #define STATE_NEEDS_CLOSING(state) ((state) == SSTATE_FLUSHING)
1185
1186 /* Unidirectional transfer. */
1187 struct unidirectional_transfer {
1188         /* Source */
1189         int src;
1190         /* Destination */
1191         int dest;
1192         /* Is source socket? */
1193         int src_is_sock;
1194         /* Is destination socket? */
1195         int dest_is_sock;
1196         /* Transfer state (TRANSFERRING/FLUSHING/FINISHED) */
1197         int state;
1198         /* Buffer. */
1199         char buf[BUFFERSIZE];
1200         /* Buffer used. */
1201         size_t bufuse;
1202         /* Name of source. */
1203         const char *src_name;
1204         /* Name of destination. */
1205         const char *dest_name;
1206 };
1207
1208 /* Closes the target (for writing) if transfer has finished. */
1209 static void udt_close_if_finished(struct unidirectional_transfer *t)
1210 {
1211         if (STATE_NEEDS_CLOSING(t->state) && !t->bufuse) {
1212                 t->state = SSTATE_FINISHED;
1213                 if (t->dest_is_sock)
1214                         shutdown(t->dest, SHUT_WR);
1215                 else
1216                         close(t->dest);
1217                 transfer_debug("Closed %s.", t->dest_name);
1218         }
1219 }
1220
1221 /*
1222  * Tries to read data from source into buffer. If buffer is full,
1223  * no data is read. Returns 0 on success, -1 on error.
1224  */
1225 static int udt_do_read(struct unidirectional_transfer *t)
1226 {
1227         ssize_t bytes;
1228
1229         if (t->bufuse == BUFFERSIZE)
1230                 return 0;       /* No space for more. */
1231
1232         transfer_debug("%s is readable", t->src_name);
1233         bytes = read(t->src, t->buf + t->bufuse, BUFFERSIZE - t->bufuse);
1234         if (bytes < 0 && errno != EWOULDBLOCK && errno != EAGAIN &&
1235                 errno != EINTR) {
1236                 error_errno("read(%s) failed", t->src_name);
1237                 return -1;
1238         } else if (bytes == 0) {
1239                 transfer_debug("%s EOF (with %i bytes in buffer)",
1240                         t->src_name, (int)t->bufuse);
1241                 t->state = SSTATE_FLUSHING;
1242         } else if (bytes > 0) {
1243                 t->bufuse += bytes;
1244                 transfer_debug("Read %i bytes from %s (buffer now at %i)",
1245                         (int)bytes, t->src_name, (int)t->bufuse);
1246         }
1247         return 0;
1248 }
1249
1250 /* Tries to write data from buffer into destination. If buffer is empty,
1251  * no data is written. Returns 0 on success, -1 on error.
1252  */
1253 static int udt_do_write(struct unidirectional_transfer *t)
1254 {
1255         ssize_t bytes;
1256
1257         if (t->bufuse == 0)
1258                 return 0;       /* Nothing to write. */
1259
1260         transfer_debug("%s is writable", t->dest_name);
1261         bytes = xwrite(t->dest, t->buf, t->bufuse);
1262         if (bytes < 0 && errno != EWOULDBLOCK) {
1263                 error_errno("write(%s) failed", t->dest_name);
1264                 return -1;
1265         } else if (bytes > 0) {
1266                 t->bufuse -= bytes;
1267                 if (t->bufuse)
1268                         memmove(t->buf, t->buf + bytes, t->bufuse);
1269                 transfer_debug("Wrote %i bytes to %s (buffer now at %i)",
1270                         (int)bytes, t->dest_name, (int)t->bufuse);
1271         }
1272         return 0;
1273 }
1274
1275
1276 /* State of bidirectional transfer loop. */
1277 struct bidirectional_transfer_state {
1278         /* Direction from program to git. */
1279         struct unidirectional_transfer ptg;
1280         /* Direction from git to program. */
1281         struct unidirectional_transfer gtp;
1282 };
1283
1284 static void *udt_copy_task_routine(void *udt)
1285 {
1286         struct unidirectional_transfer *t = (struct unidirectional_transfer *)udt;
1287         while (t->state != SSTATE_FINISHED) {
1288                 if (STATE_NEEDS_READING(t->state))
1289                         if (udt_do_read(t))
1290                                 return NULL;
1291                 if (STATE_NEEDS_WRITING(t->state))
1292                         if (udt_do_write(t))
1293                                 return NULL;
1294                 if (STATE_NEEDS_CLOSING(t->state))
1295                         udt_close_if_finished(t);
1296         }
1297         return udt;     /* Just some non-NULL value. */
1298 }
1299
1300 #ifndef NO_PTHREADS
1301
1302 /*
1303  * Join thread, with appropriate errors on failure. Name is name for the
1304  * thread (for error messages). Returns 0 on success, 1 on failure.
1305  */
1306 static int tloop_join(pthread_t thread, const char *name)
1307 {
1308         int err;
1309         void *tret;
1310         err = pthread_join(thread, &tret);
1311         if (!tret) {
1312                 error("%s thread failed", name);
1313                 return 1;
1314         }
1315         if (err) {
1316                 error("%s thread failed to join: %s", name, strerror(err));
1317                 return 1;
1318         }
1319         return 0;
1320 }
1321
1322 /*
1323  * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1324  * -1 on failure.
1325  */
1326 static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1327 {
1328         pthread_t gtp_thread;
1329         pthread_t ptg_thread;
1330         int err;
1331         int ret = 0;
1332         err = pthread_create(&gtp_thread, NULL, udt_copy_task_routine,
1333                 &s->gtp);
1334         if (err)
1335                 die("Can't start thread for copying data: %s", strerror(err));
1336         err = pthread_create(&ptg_thread, NULL, udt_copy_task_routine,
1337                 &s->ptg);
1338         if (err)
1339                 die("Can't start thread for copying data: %s", strerror(err));
1340
1341         ret |= tloop_join(gtp_thread, "Git to program copy");
1342         ret |= tloop_join(ptg_thread, "Program to git copy");
1343         return ret;
1344 }
1345 #else
1346
1347 /* Close the source and target (for writing) for transfer. */
1348 static void udt_kill_transfer(struct unidirectional_transfer *t)
1349 {
1350         t->state = SSTATE_FINISHED;
1351         /*
1352          * Socket read end left open isn't a disaster if nobody
1353          * attempts to read from it (mingw compat headers do not
1354          * have SHUT_RD)...
1355          *
1356          * We can't fully close the socket since otherwise gtp
1357          * task would first close the socket it sends data to
1358          * while closing the ptg file descriptors.
1359          */
1360         if (!t->src_is_sock)
1361                 close(t->src);
1362         if (t->dest_is_sock)
1363                 shutdown(t->dest, SHUT_WR);
1364         else
1365                 close(t->dest);
1366 }
1367
1368 /*
1369  * Join process, with appropriate errors on failure. Name is name for the
1370  * process (for error messages). Returns 0 on success, 1 on failure.
1371  */
1372 static int tloop_join(pid_t pid, const char *name)
1373 {
1374         int tret;
1375         if (waitpid(pid, &tret, 0) < 0) {
1376                 error_errno("%s process failed to wait", name);
1377                 return 1;
1378         }
1379         if (!WIFEXITED(tret) || WEXITSTATUS(tret)) {
1380                 error("%s process failed", name);
1381                 return 1;
1382         }
1383         return 0;
1384 }
1385
1386 /*
1387  * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1388  * -1 on failure.
1389  */
1390 static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1391 {
1392         pid_t pid1, pid2;
1393         int ret = 0;
1394
1395         /* Fork thread #1: git to program. */
1396         pid1 = fork();
1397         if (pid1 < 0)
1398                 die_errno("Can't start thread for copying data");
1399         else if (pid1 == 0) {
1400                 udt_kill_transfer(&s->ptg);
1401                 exit(udt_copy_task_routine(&s->gtp) ? 0 : 1);
1402         }
1403
1404         /* Fork thread #2: program to git. */
1405         pid2 = fork();
1406         if (pid2 < 0)
1407                 die_errno("Can't start thread for copying data");
1408         else if (pid2 == 0) {
1409                 udt_kill_transfer(&s->gtp);
1410                 exit(udt_copy_task_routine(&s->ptg) ? 0 : 1);
1411         }
1412
1413         /*
1414          * Close both streams in parent as to not interfere with
1415          * end of file detection and wait for both tasks to finish.
1416          */
1417         udt_kill_transfer(&s->gtp);
1418         udt_kill_transfer(&s->ptg);
1419         ret |= tloop_join(pid1, "Git to program copy");
1420         ret |= tloop_join(pid2, "Program to git copy");
1421         return ret;
1422 }
1423 #endif
1424
1425 /*
1426  * Copies data from stdin to output and from input to stdout simultaneously.
1427  * Additionally filtering through given filter. If filter is NULL, uses
1428  * identity filter.
1429  */
1430 int bidirectional_transfer_loop(int input, int output)
1431 {
1432         struct bidirectional_transfer_state state;
1433
1434         /* Fill the state fields. */
1435         state.ptg.src = input;
1436         state.ptg.dest = 1;
1437         state.ptg.src_is_sock = (input == output);
1438         state.ptg.dest_is_sock = 0;
1439         state.ptg.state = SSTATE_TRANSFERRING;
1440         state.ptg.bufuse = 0;
1441         state.ptg.src_name = "remote input";
1442         state.ptg.dest_name = "stdout";
1443
1444         state.gtp.src = 0;
1445         state.gtp.dest = output;
1446         state.gtp.src_is_sock = 0;
1447         state.gtp.dest_is_sock = (input == output);
1448         state.gtp.state = SSTATE_TRANSFERRING;
1449         state.gtp.bufuse = 0;
1450         state.gtp.src_name = "stdin";
1451         state.gtp.dest_name = "remote output";
1452
1453         return tloop_spawnwait_tasks(&state);
1454 }