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 "refspec.h"
  15 #include "transport-internal.h"
  16 #include "protocol.h"
  17
  18 static int debug;
  19
  20 struct helper_data {
  21         const char *name;
  22         struct child_process *helper;
  23         FILE *out;
  24         unsigned fetch : 1,
  25                 import : 1,
  26                 bidi_import : 1,
  27                 export : 1,
  28                 option : 1,
  29                 push : 1,
  30                 connect : 1,
  31                 stateless_connect : 1,
  32                 signed_tags : 1,
  33                 check_connectivity : 1,
  34                 no_disconnect_req : 1,
  35                 no_private_update : 1;
  36
  37         /*
  38          * As an optimization, the transport code may invoke fetch before
  39          * get_refs_list. If this happens, and if the transport helper doesn't
  40          * support connect or stateless_connect, we need to invoke
  41          * get_refs_list ourselves if we haven't already done so. Keep track of
  42          * whether we have invoked get_refs_list.
  43          */
  44         unsigned get_refs_list_called : 1;
  45
  46         char *export_marks;
  47         char *import_marks;
  48         /* These go from remote name (as in "list") to private name */
  49         struct refspec rs;
  50         /* Transport options for fetch-pack/send-pack (should one of
  51          * those be invoked).
  52          */
  53         struct git_transport_options transport_options;
  54 };
  55
  56 static void sendline(struct helper_data *helper, struct strbuf *buffer)
  57 {
  58         if (debug)
  59                 fprintf(stderr, "Debug: Remote helper: -> %s", buffer->buf);
  60         if (write_in_full(helper->helper->in, buffer->buf, buffer->len) < 0)
  61                 die_errno(_("full write to remote helper failed"));
  62 }
  63
  64 static int recvline_fh(FILE *helper, struct strbuf *buffer)
  65 {
  66         strbuf_reset(buffer);
  67         if (debug)
  68                 fprintf(stderr, "Debug: Remote helper: Waiting...\n");
  69         if (strbuf_getline(buffer, helper) == EOF) {
  70                 if (debug)
  71                         fprintf(stderr, "Debug: Remote helper quit.\n");
  72                 return 1;
  73         }
  74
  75         if (debug)
  76                 fprintf(stderr, "Debug: Remote helper: <- %s\n", buffer->buf);
  77         return 0;
  78 }
  79
  80 static int recvline(struct helper_data *helper, struct strbuf *buffer)
  81 {
  82         return recvline_fh(helper->out, buffer);
  83 }
  84
  85 static void write_constant(int fd, const char *str)
  86 {
  87         if (debug)
  88                 fprintf(stderr, "Debug: Remote helper: -> %s", str);
  89         if (write_in_full(fd, str, strlen(str)) < 0)
  90                 die_errno(_("full write to remote helper failed"));
  91 }
  92
  93 static const char *remove_ext_force(const char *url)
  94 {
  95         if (url) {
  96                 const char *colon = strchr(url, ':');
  97                 if (colon && colon[1] == ':')
  98                         return colon + 2;
  99         }
 100         return url;
 101 }
 102
 103 static void do_take_over(struct transport *transport)
 104 {
 105         struct helper_data *data;
 106         data = (struct helper_data *)transport->data;
 107         transport_take_over(transport, data->helper);
 108         fclose(data->out);
 109         free(data);
 110 }
 111
 112 static void standard_options(struct transport *t);
 113
 114 static struct child_process *get_helper(struct transport *transport)
 115 {
 116         struct helper_data *data = transport->data;
 117         struct strbuf buf = STRBUF_INIT;
 118         struct child_process *helper;
 119         int duped;
 120         int code;
 121
 122         if (data->helper)
 123                 return data->helper;
 124
 125         helper = xmalloc(sizeof(*helper));
 126         child_process_init(helper);
 127         helper->in = -1;
 128         helper->out = -1;
 129         helper->err = 0;
 130         argv_array_pushf(&helper->args, "git-remote-%s", data->name);
 131         argv_array_push(&helper->args, transport->remote->name);
 132         argv_array_push(&helper->args, remove_ext_force(transport->url));
 133         helper->git_cmd = 0;
 134         helper->silent_exec_failure = 1;
 135
 136         if (have_git_dir())
 137                 argv_array_pushf(&helper->env_array, "%s=%s",
 138                                  GIT_DIR_ENVIRONMENT, get_git_dir());
 139
 140         helper->trace2_child_class = helper->args.argv[0]; /* "remote-<name>" */
 141
 142         code = start_command(helper);
 143         if (code < 0 && errno == ENOENT)
 144                 die(_("unable to find remote helper for '%s'"), data->name);
 145         else if (code != 0)
 146                 exit(code);
 147
 148         data->helper = helper;
 149         data->no_disconnect_req = 0;
 150         refspec_init(&data->rs, REFSPEC_FETCH);
 151
 152         /*
 153          * Open the output as FILE* so strbuf_getline_*() family of
 154          * functions can be used.
 155          * Do this with duped fd because fclose() will close the fd,
 156          * and stuff like taking over will require the fd to remain.
 157          */
 158         duped = dup(helper->out);
 159         if (duped < 0)
 160                 die_errno(_("can't dup helper output fd"));
 161         data->out = xfdopen(duped, "r");
 162
 163         write_constant(helper->in, "capabilities\n");
 164
 165         while (1) {
 166                 const char *capname, *arg;
 167                 int mandatory = 0;
 168                 if (recvline(data, &buf))
 169                         exit(128);
 170
 171                 if (!*buf.buf)
 172                         break;
 173
 174                 if (*buf.buf == '*') {
 175                         capname = buf.buf + 1;
 176                         mandatory = 1;
 177                 } else
 178                         capname = buf.buf;
 179
 180                 if (debug)
 181                         fprintf(stderr, "Debug: Got cap %s\n", capname);
 182                 if (!strcmp(capname, "fetch"))
 183                         data->fetch = 1;
 184                 else if (!strcmp(capname, "option"))
 185                         data->option = 1;
 186                 else if (!strcmp(capname, "push"))
 187                         data->push = 1;
 188                 else if (!strcmp(capname, "import"))
 189                         data->import = 1;
 190                 else if (!strcmp(capname, "bidi-import"))
 191                         data->bidi_import = 1;
 192                 else if (!strcmp(capname, "export"))
 193                         data->export = 1;
 194                 else if (!strcmp(capname, "check-connectivity"))
 195                         data->check_connectivity = 1;
 196                 else if (skip_prefix(capname, "refspec ", &arg)) {
 197                         refspec_append(&data->rs, arg);
 198                 } else if (!strcmp(capname, "connect")) {
 199                         data->connect = 1;
 200                 } else if (!strcmp(capname, "stateless-connect")) {
 201                         data->stateless_connect = 1;
 202                 } else if (!strcmp(capname, "signed-tags")) {
 203                         data->signed_tags = 1;
 204                 } else if (skip_prefix(capname, "export-marks ", &arg)) {
 205                         data->export_marks = xstrdup(arg);
 206                 } else if (skip_prefix(capname, "import-marks ", &arg)) {
 207                         data->import_marks = xstrdup(arg);
 208                 } else if (starts_with(capname, "no-private-update")) {
 209                         data->no_private_update = 1;
 210                 } else if (mandatory) {
 211                         die(_("unknown mandatory capability %s; this remote "
 212                               "helper probably needs newer version of Git"),
 213                             capname);
 214                 }
 215         }
 216         if (!data->rs.nr && (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         refspec_clear(&data->rs);
 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                 const char *name;
 408
 409                 if (recvline(data, &buf))
 410                         exit(128);
 411
 412                 if (skip_prefix(buf.buf, "lock ", &name)) {
 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 = xdup(helper->out);
 438         argv_array_push(&fastimport->args, "fast-import");
 439         argv_array_push(&fastimport->args, "--allow-unsafe-features");
 440         argv_array_push(&fastimport->args, debug ? "--stats" : "--quiet");
 441
 442         if (data->bidi_import) {
 443                 cat_blob_fd = xdup(helper->in);
 444                 argv_array_pushf(&fastimport->args, "--cat-blob-fd=%d", cat_blob_fd);
 445         }
 446         fastimport->git_cmd = 1;
 447
 448         code = start_command(fastimport);
 449         return code;
 450 }
 451
 452 static int get_exporter(struct transport *transport,
 453                         struct child_process *fastexport,
 454                         struct string_list *revlist_args)
 455 {
 456         struct helper_data *data = transport->data;
 457         struct child_process *helper = get_helper(transport);
 458         int i;
 459
 460         child_process_init(fastexport);
 461
 462         /* we need to duplicate helper->in because we want to use it after
 463          * fastexport is done with it. */
 464         fastexport->out = dup(helper->in);
 465         argv_array_push(&fastexport->args, "fast-export");
 466         argv_array_push(&fastexport->args, "--use-done-feature");
 467         argv_array_push(&fastexport->args, data->signed_tags ?
 468                 "--signed-tags=verbatim" : "--signed-tags=warn-strip");
 469         if (data->export_marks)
 470                 argv_array_pushf(&fastexport->args, "--export-marks=%s.tmp", data->export_marks);
 471         if (data->import_marks)
 472                 argv_array_pushf(&fastexport->args, "--import-marks=%s", data->import_marks);
 473
 474         for (i = 0; i < revlist_args->nr; i++)
 475                 argv_array_push(&fastexport->args, revlist_args->items[i].string);
 476
 477         fastexport->git_cmd = 1;
 478         return start_command(fastexport);
 479 }
 480
 481 static int fetch_with_import(struct transport *transport,
 482                              int nr_heads, struct ref **to_fetch)
 483 {
 484         struct child_process fastimport;
 485         struct helper_data *data = transport->data;
 486         int i;
 487         struct ref *posn;
 488         struct strbuf buf = STRBUF_INIT;
 489
 490         get_helper(transport);
 491
 492         if (get_importer(transport, &fastimport))
 493                 die(_("couldn't run fast-import"));
 494
 495         for (i = 0; i < nr_heads; i++) {
 496                 posn = to_fetch[i];
 497                 if (posn->status & REF_STATUS_UPTODATE)
 498                         continue;
 499
 500                 strbuf_addf(&buf, "import %s\n",
 501                             posn->symref ? posn->symref : posn->name);
 502                 sendline(data, &buf);
 503                 strbuf_reset(&buf);
 504         }
 505
 506         write_constant(data->helper->in, "\n");
 507         /*
 508          * remote-helpers that advertise the bidi-import capability are required to
 509          * buffer the complete batch of import commands until this newline before
 510          * sending data to fast-import.
 511          * These helpers read back data from fast-import on their stdin, which could
 512          * be mixed with import commands, otherwise.
 513          */
 514
 515         if (finish_command(&fastimport))
 516                 die(_("error while running fast-import"));
 517
 518         /*
 519          * The fast-import stream of a remote helper that advertises
 520          * the "refspec" capability writes to the refs named after the
 521          * right hand side of the first refspec matching each ref we
 522          * were fetching.
 523          *
 524          * (If no "refspec" capability was specified, for historical
 525          * reasons we default to the equivalent of *:*.)
 526          *
 527          * Store the result in to_fetch[i].old_sha1.  Callers such
 528          * as "git fetch" can use the value to write feedback to the
 529          * terminal, populate FETCH_HEAD, and determine what new value
 530          * should be written to peer_ref if the update is a
 531          * fast-forward or this is a forced update.
 532          */
 533         for (i = 0; i < nr_heads; i++) {
 534                 char *private, *name;
 535                 posn = to_fetch[i];
 536                 if (posn->status & REF_STATUS_UPTODATE)
 537                         continue;
 538                 name = posn->symref ? posn->symref : posn->name;
 539                 if (data->rs.nr)
 540                         private = apply_refspecs(&data->rs, name);
 541                 else
 542                         private = xstrdup(name);
 543                 if (private) {
 544                         if (read_ref(private, &posn->old_oid) < 0)
 545                                 die(_("could not read ref %s"), private);
 546                         free(private);
 547                 }
 548         }
 549         strbuf_release(&buf);
 550         return 0;
 551 }
 552
 553 static int run_connect(struct transport *transport, struct strbuf *cmdbuf)
 554 {
 555         struct helper_data *data = transport->data;
 556         int ret = 0;
 557         int duped;
 558         FILE *input;
 559         struct child_process *helper;
 560
 561         helper = get_helper(transport);
 562
 563         /*
 564          * Yes, dup the pipe another time, as we need unbuffered version
 565          * of input pipe as FILE*. fclose() closes the underlying fd and
 566          * stream buffering only can be changed before first I/O operation
 567          * on it.
 568          */
 569         duped = dup(helper->out);
 570         if (duped < 0)
 571                 die_errno(_("can't dup helper output fd"));
 572         input = xfdopen(duped, "r");
 573         setvbuf(input, NULL, _IONBF, 0);
 574
 575         sendline(data, cmdbuf);
 576         if (recvline_fh(input, cmdbuf))
 577                 exit(128);
 578
 579         if (!strcmp(cmdbuf->buf, "")) {
 580                 data->no_disconnect_req = 1;
 581                 if (debug)
 582                         fprintf(stderr, "Debug: Smart transport connection "
 583                                 "ready.\n");
 584                 ret = 1;
 585         } else if (!strcmp(cmdbuf->buf, "fallback")) {
 586                 if (debug)
 587                         fprintf(stderr, "Debug: Falling back to dumb "
 588                                 "transport.\n");
 589         } else {
 590                 die(_("unknown response to connect: %s"),
 591                     cmdbuf->buf);
 592         }
 593
 594         fclose(input);
 595         return ret;
 596 }
 597
 598 static int process_connect_service(struct transport *transport,
 599                                    const char *name, const char *exec)
 600 {
 601         struct helper_data *data = transport->data;
 602         struct strbuf cmdbuf = STRBUF_INIT;
 603         int ret = 0;
 604
 605         /*
 606          * Handle --upload-pack and friends. This is fire and forget...
 607          * just warn if it fails.
 608          */
 609         if (strcmp(name, exec)) {
 610                 int r = set_helper_option(transport, "servpath", exec);
 611                 if (r > 0)
 612                         warning(_("setting remote service path not supported by protocol"));
 613                 else if (r < 0)
 614                         warning(_("invalid remote service path"));
 615         }
 616
 617         if (data->connect) {
 618                 strbuf_addf(&cmdbuf, "connect %s\n", name);
 619                 ret = run_connect(transport, &cmdbuf);
 620         } else if (data->stateless_connect &&
 621                    (get_protocol_version_config() == protocol_v2) &&
 622                    !strcmp("git-upload-pack", name)) {
 623                 strbuf_addf(&cmdbuf, "stateless-connect %s\n", name);
 624                 ret = run_connect(transport, &cmdbuf);
 625                 if (ret)
 626                         transport->stateless_rpc = 1;
 627         }
 628
 629         strbuf_release(&cmdbuf);
 630         return ret;
 631 }
 632
 633 static int process_connect(struct transport *transport,
 634                                      int for_push)
 635 {
 636         struct helper_data *data = transport->data;
 637         const char *name;
 638         const char *exec;
 639
 640         name = for_push ? "git-receive-pack" : "git-upload-pack";
 641         if (for_push)
 642                 exec = data->transport_options.receivepack;
 643         else
 644                 exec = data->transport_options.uploadpack;
 645
 646         return process_connect_service(transport, name, exec);
 647 }
 648
 649 static int connect_helper(struct transport *transport, const char *name,
 650                    const char *exec, int fd[2])
 651 {
 652         struct helper_data *data = transport->data;
 653
 654         /* Get_helper so connect is inited. */
 655         get_helper(transport);
 656         if (!data->connect)
 657                 die(_("operation not supported by protocol"));
 658
 659         if (!process_connect_service(transport, name, exec))
 660                 die(_("can't connect to subservice %s"), name);
 661
 662         fd[0] = data->helper->out;
 663         fd[1] = data->helper->in;
 664         return 0;
 665 }
 666
 667 static struct ref *get_refs_list_using_list(struct transport *transport,
 668                                             int for_push);
 669
 670 static int fetch(struct transport *transport,
 671                  int nr_heads, struct ref **to_fetch)
 672 {
 673         struct helper_data *data = transport->data;
 674         int i, count;
 675
 676         get_helper(transport);
 677
 678         if (process_connect(transport, 0)) {
 679                 do_take_over(transport);
 680                 return transport->vtable->fetch(transport, nr_heads, to_fetch);
 681         }
 682
 683         if (!data->get_refs_list_called)
 684                 get_refs_list_using_list(transport, 0);
 685
 686         count = 0;
 687         for (i = 0; i < nr_heads; i++)
 688                 if (!(to_fetch[i]->status & REF_STATUS_UPTODATE))
 689                         count++;
 690
 691         if (!count)
 692                 return 0;
 693
 694         if (data->check_connectivity &&
 695             data->transport_options.check_self_contained_and_connected)
 696                 set_helper_option(transport, "check-connectivity", "true");
 697
 698         if (transport->cloning)
 699                 set_helper_option(transport, "cloning", "true");
 700
 701         if (data->transport_options.update_shallow)
 702                 set_helper_option(transport, "update-shallow", "true");
 703
 704         if (data->transport_options.filter_options.choice) {
 705                 const char *spec = expand_list_objects_filter_spec(
 706                         &data->transport_options.filter_options);
 707                 set_helper_option(transport, "filter", spec);
 708         }
 709
 710         if (data->transport_options.negotiation_tips)
 711                 warning("Ignoring --negotiation-tip because the protocol does not support it.");
 712
 713         if (data->fetch)
 714                 return fetch_with_fetch(transport, nr_heads, to_fetch);
 715
 716         if (data->import)
 717                 return fetch_with_import(transport, nr_heads, to_fetch);
 718
 719         return -1;
 720 }
 721
 722 struct push_update_ref_state {
 723         struct ref *hint;
 724         struct ref_push_report *report;
 725         int new_report;
 726 };
 727
 728 static int push_update_ref_status(struct strbuf *buf,
 729                                    struct push_update_ref_state *state,
 730                                    struct ref *remote_refs)
 731 {
 732         char *refname, *msg;
 733         int status, forced = 0;
 734
 735         if (starts_with(buf->buf, "option ")) {
 736                 struct object_id old_oid, new_oid;
 737                 const char *key, *val;
 738                 char *p;
 739
 740                 if (!state->hint || !(state->report || state->new_report))
 741                         die(_("'option' without a matching 'ok/error' directive"));
 742                 if (state->new_report) {
 743                         if (!state->hint->report) {
 744                                 state->hint->report = xcalloc(1, sizeof(struct ref_push_report));
 745                                 state->report = state->hint->report;
 746                         } else {
 747                                 state->report = state->hint->report;
 748                                 while (state->report->next)
 749                                         state->report = state->report->next;
 750                                 state->report->next = xcalloc(1, sizeof(struct ref_push_report));
 751                                 state->report = state->report->next;
 752                         }
 753                         state->new_report = 0;
 754                 }
 755                 key = buf->buf + 7;
 756                 p = strchr(key, ' ');
 757                 if (p)
 758                         *p++ = '\0';
 759                 val = p;
 760                 if (!strcmp(key, "refname"))
 761                         state->report->ref_name = xstrdup_or_null(val);
 762                 else if (!strcmp(key, "old-oid") && val &&
 763                          !parse_oid_hex(val, &old_oid, &val))
 764                         state->report->old_oid = oiddup(&old_oid);
 765                 else if (!strcmp(key, "new-oid") && val &&
 766                          !parse_oid_hex(val, &new_oid, &val))
 767                         state->report->new_oid = oiddup(&new_oid);
 768                 else if (!strcmp(key, "forced-update"))
 769                         state->report->forced_update = 1;
 770                 /* Not update remote namespace again. */
 771                 return 1;
 772         }
 773
 774         state->report = NULL;
 775         state->new_report = 0;
 776
 777         if (starts_with(buf->buf, "ok ")) {
 778                 status = REF_STATUS_OK;
 779                 refname = buf->buf + 3;
 780         } else if (starts_with(buf->buf, "error ")) {
 781                 status = REF_STATUS_REMOTE_REJECT;
 782                 refname = buf->buf + 6;
 783         } else
 784                 die(_("expected ok/error, helper said '%s'"), buf->buf);
 785
 786         msg = strchr(refname, ' ');
 787         if (msg) {
 788                 struct strbuf msg_buf = STRBUF_INIT;
 789                 const char *end;
 790
 791                 *msg++ = '\0';
 792                 if (!unquote_c_style(&msg_buf, msg, &end))
 793                         msg = strbuf_detach(&msg_buf, NULL);
 794                 else
 795                         msg = xstrdup(msg);
 796                 strbuf_release(&msg_buf);
 797
 798                 if (!strcmp(msg, "no match")) {
 799                         status = REF_STATUS_NONE;
 800                         FREE_AND_NULL(msg);
 801                 }
 802                 else if (!strcmp(msg, "up to date")) {
 803                         status = REF_STATUS_UPTODATE;
 804                         FREE_AND_NULL(msg);
 805                 }
 806                 else if (!strcmp(msg, "non-fast forward")) {
 807                         status = REF_STATUS_REJECT_NONFASTFORWARD;
 808                         FREE_AND_NULL(msg);
 809                 }
 810                 else if (!strcmp(msg, "already exists")) {
 811                         status = REF_STATUS_REJECT_ALREADY_EXISTS;
 812                         FREE_AND_NULL(msg);
 813                 }
 814                 else if (!strcmp(msg, "fetch first")) {
 815                         status = REF_STATUS_REJECT_FETCH_FIRST;
 816                         FREE_AND_NULL(msg);
 817                 }
 818                 else if (!strcmp(msg, "needs force")) {
 819                         status = REF_STATUS_REJECT_NEEDS_FORCE;
 820                         FREE_AND_NULL(msg);
 821                 }
 822                 else if (!strcmp(msg, "stale info")) {
 823                         status = REF_STATUS_REJECT_STALE;
 824                         FREE_AND_NULL(msg);
 825                 }
 826                 else if (!strcmp(msg, "forced update")) {
 827                         forced = 1;
 828                         FREE_AND_NULL(msg);
 829                 }
 830         }
 831
 832         if (state->hint)
 833                 state->hint = find_ref_by_name(state->hint, refname);
 834         if (!state->hint)
 835                 state->hint = find_ref_by_name(remote_refs, refname);
 836         if (!state->hint) {
 837                 warning(_("helper reported unexpected status of %s"), refname);
 838                 return 1;
 839         }
 840
 841         if (state->hint->status != REF_STATUS_NONE) {
 842                 /*
 843                  * Earlier, the ref was marked not to be pushed, so ignore the ref
 844                  * status reported by the remote helper if the latter is 'no match'.
 845                  */
 846                 if (status == REF_STATUS_NONE)
 847                         return 1;
 848         }
 849
 850         if (status == REF_STATUS_OK)
 851                 state->new_report = 1;
 852         state->hint->status = status;
 853         state->hint->forced_update |= forced;
 854         state->hint->remote_status = msg;
 855         return !(status == REF_STATUS_OK);
 856 }
 857
 858 static int push_update_refs_status(struct helper_data *data,
 859                                     struct ref *remote_refs,
 860                                     int flags)
 861 {
 862         struct ref *ref;
 863         struct ref_push_report *report;
 864         struct strbuf buf = STRBUF_INIT;
 865         struct push_update_ref_state state = { remote_refs, NULL, 0 };
 866
 867         for (;;) {
 868                 if (recvline(data, &buf)) {
 869                         strbuf_release(&buf);
 870                         return 1;
 871                 }
 872                 if (!buf.len)
 873                         break;
 874                 push_update_ref_status(&buf, &state, remote_refs);
 875         }
 876         strbuf_release(&buf);
 877
 878         if (flags & TRANSPORT_PUSH_DRY_RUN || !data->rs.nr || data->no_private_update)
 879                 return 0;
 880
 881         /* propagate back the update to the remote namespace */
 882         for (ref = remote_refs; ref; ref = ref->next) {
 883                 char *private;
 884
 885                 if (ref->status != REF_STATUS_OK)
 886                         continue;
 887
 888                 if (!ref->report) {
 889                         private = apply_refspecs(&data->rs, ref->name);
 890                         if (!private)
 891                                 continue;
 892                         update_ref("update by helper", private, &(ref->new_oid),
 893                                    NULL, 0, 0);
 894                         free(private);
 895                 } else {
 896                         for (report = ref->report; report; report = report->next) {
 897                                 private = apply_refspecs(&data->rs,
 898                                                          report->ref_name
 899                                                          ? report->ref_name
 900                                                          : ref->name);
 901                                 if (!private)
 902                                         continue;
 903                                 update_ref("update by helper", private,
 904                                            report->new_oid
 905                                            ? report->new_oid
 906                                            : &(ref->new_oid),
 907                                            NULL, 0, 0);
 908                                 free(private);
 909                         }
 910                 }
 911         }
 912         return 0;
 913 }
 914
 915 static void set_common_push_options(struct transport *transport,
 916                                    const char *name, int flags)
 917 {
 918         if (flags & TRANSPORT_PUSH_DRY_RUN) {
 919                 if (set_helper_option(transport, "dry-run", "true") != 0)
 920                         die(_("helper %s does not support dry-run"), name);
 921         } else if (flags & TRANSPORT_PUSH_CERT_ALWAYS) {
 922                 if (set_helper_option(transport, TRANS_OPT_PUSH_CERT, "true") != 0)
 923                         die(_("helper %s does not support --signed"), name);
 924         } else if (flags & TRANSPORT_PUSH_CERT_IF_ASKED) {
 925                 if (set_helper_option(transport, TRANS_OPT_PUSH_CERT, "if-asked") != 0)
 926                         die(_("helper %s does not support --signed=if-asked"), name);
 927         }
 928
 929         if (flags & TRANSPORT_PUSH_ATOMIC)
 930                 if (set_helper_option(transport, TRANS_OPT_ATOMIC, "true") != 0)
 931                         die(_("helper %s does not support --atomic"), name);
 932
 933         if (flags & TRANSPORT_PUSH_OPTIONS) {
 934                 struct string_list_item *item;
 935                 for_each_string_list_item(item, transport->push_options)
 936                         if (set_helper_option(transport, "push-option", item->string) != 0)
 937                                 die(_("helper %s does not support 'push-option'"), name);
 938         }
 939 }
 940
 941 static int push_refs_with_push(struct transport *transport,
 942                                struct ref *remote_refs, int flags)
 943 {
 944         int force_all = flags & TRANSPORT_PUSH_FORCE;
 945         int mirror = flags & TRANSPORT_PUSH_MIRROR;
 946         int atomic = flags & TRANSPORT_PUSH_ATOMIC;
 947         struct helper_data *data = transport->data;
 948         struct strbuf buf = STRBUF_INIT;
 949         struct ref *ref;
 950         struct string_list cas_options = STRING_LIST_INIT_DUP;
 951         struct string_list_item *cas_option;
 952
 953         get_helper(transport);
 954         if (!data->push)
 955                 return 1;
 956
 957         for (ref = remote_refs; ref; ref = ref->next) {
 958                 if (!ref->peer_ref && !mirror)
 959                         continue;
 960
 961                 /* Check for statuses set by set_ref_status_for_push() */
 962                 switch (ref->status) {
 963                 case REF_STATUS_REJECT_NONFASTFORWARD:
 964                 case REF_STATUS_REJECT_STALE:
 965                 case REF_STATUS_REJECT_ALREADY_EXISTS:
 966                         if (atomic) {
 967                                 reject_atomic_push(remote_refs, mirror);
 968                                 string_list_clear(&cas_options, 0);
 969                                 return 0;
 970                         } else
 971                                 continue;
 972                 case REF_STATUS_UPTODATE:
 973                         continue;
 974                 default:
 975                         ; /* do nothing */
 976                 }
 977
 978                 if (force_all)
 979                         ref->force = 1;
 980
 981                 strbuf_addstr(&buf, "push ");
 982                 if (!ref->deletion) {
 983                         if (ref->force)
 984                                 strbuf_addch(&buf, '+');
 985                         if (ref->peer_ref)
 986                                 strbuf_addstr(&buf, ref->peer_ref->name);
 987                         else
 988                                 strbuf_addstr(&buf, oid_to_hex(&ref->new_oid));
 989                 }
 990                 strbuf_addch(&buf, ':');
 991                 strbuf_addstr(&buf, ref->name);
 992                 strbuf_addch(&buf, '\n');
 993
 994                 /*
 995                  * The "--force-with-lease" options without explicit
 996                  * values to expect have already been expanded into
 997                  * the ref->old_oid_expect[] field; we can ignore
 998                  * transport->smart_options->cas altogether and instead
 999                  * can enumerate them from the refs.
1000                  */
1001                 if (ref->expect_old_sha1) {
1002                         struct strbuf cas = STRBUF_INIT;
1003                         strbuf_addf(&cas, "%s:%s",
1004                                     ref->name, oid_to_hex(&ref->old_oid_expect));
1005                         string_list_append_nodup(&cas_options,
1006                                                  strbuf_detach(&cas, NULL));
1007                 }
1008         }
1009         if (buf.len == 0) {
1010                 string_list_clear(&cas_options, 0);
1011                 return 0;
1012         }
1013
1014         for_each_string_list_item(cas_option, &cas_options)
1015                 set_helper_option(transport, "cas", cas_option->string);
1016         set_common_push_options(transport, data->name, flags);
1017
1018         strbuf_addch(&buf, '\n');
1019         sendline(data, &buf);
1020         strbuf_release(&buf);
1021         string_list_clear(&cas_options, 0);
1022
1023         return push_update_refs_status(data, remote_refs, flags);
1024 }
1025
1026 static int push_refs_with_export(struct transport *transport,
1027                 struct ref *remote_refs, int flags)
1028 {
1029         struct ref *ref;
1030         struct child_process *helper, exporter;
1031         struct helper_data *data = transport->data;
1032         struct string_list revlist_args = STRING_LIST_INIT_DUP;
1033         struct strbuf buf = STRBUF_INIT;
1034
1035         if (!data->rs.nr)
1036                 die(_("remote-helper doesn't support push; refspec needed"));
1037
1038         set_common_push_options(transport, data->name, flags);
1039         if (flags & TRANSPORT_PUSH_FORCE) {
1040                 if (set_helper_option(transport, "force", "true") != 0)
1041                         warning(_("helper %s does not support 'force'"), data->name);
1042         }
1043
1044         helper = get_helper(transport);
1045
1046         write_constant(helper->in, "export\n");
1047
1048         for (ref = remote_refs; ref; ref = ref->next) {
1049                 char *private;
1050                 struct object_id oid;
1051
1052                 private = apply_refspecs(&data->rs, ref->name);
1053                 if (private && !get_oid(private, &oid)) {
1054                         strbuf_addf(&buf, "^%s", private);
1055                         string_list_append_nodup(&revlist_args,
1056                                                  strbuf_detach(&buf, NULL));
1057                         oidcpy(&ref->old_oid, &oid);
1058                 }
1059                 free(private);
1060
1061                 if (ref->peer_ref) {
1062                         if (strcmp(ref->name, ref->peer_ref->name)) {
1063                                 if (!ref->deletion) {
1064                                         const char *name;
1065                                         int flag;
1066
1067                                         /* Follow symbolic refs (mainly for HEAD). */
1068                                         name = resolve_ref_unsafe(ref->peer_ref->name,
1069                                                                   RESOLVE_REF_READING,
1070                                                                   &oid, &flag);
1071                                         if (!name || !(flag & REF_ISSYMREF))
1072                                                 name = ref->peer_ref->name;
1073
1074                                         strbuf_addf(&buf, "%s:%s", name, ref->name);
1075                                 } else
1076                                         strbuf_addf(&buf, ":%s", ref->name);
1077
1078                                 string_list_append(&revlist_args, "--refspec");
1079                                 string_list_append(&revlist_args, buf.buf);
1080                                 strbuf_release(&buf);
1081                         }
1082                         if (!ref->deletion)
1083                                 string_list_append(&revlist_args, ref->peer_ref->name);
1084                 }
1085         }
1086
1087         if (get_exporter(transport, &exporter, &revlist_args))
1088                 die(_("couldn't run fast-export"));
1089
1090         string_list_clear(&revlist_args, 1);
1091
1092         if (finish_command(&exporter))
1093                 die(_("error while running fast-export"));
1094         if (push_update_refs_status(data, remote_refs, flags))
1095                 return 1;
1096
1097         if (data->export_marks) {
1098                 strbuf_addf(&buf, "%s.tmp", data->export_marks);
1099                 rename(buf.buf, data->export_marks);
1100                 strbuf_release(&buf);
1101         }
1102
1103         return 0;
1104 }
1105
1106 static int push_refs(struct transport *transport,
1107                 struct ref *remote_refs, int flags)
1108 {
1109         struct helper_data *data = transport->data;
1110
1111         if (process_connect(transport, 1)) {
1112                 do_take_over(transport);
1113                 return transport->vtable->push_refs(transport, remote_refs, flags);
1114         }
1115
1116         if (!remote_refs) {
1117                 fprintf(stderr,
1118                         _("No refs in common and none specified; doing nothing.\n"
1119                           "Perhaps you should specify a branch such as 'master'.\n"));
1120                 return 0;
1121         }
1122
1123         if (data->push)
1124                 return push_refs_with_push(transport, remote_refs, flags);
1125
1126         if (data->export)
1127                 return push_refs_with_export(transport, remote_refs, flags);
1128
1129         return -1;
1130 }
1131
1132
1133 static int has_attribute(const char *attrs, const char *attr)
1134 {
1135         int len;
1136         if (!attrs)
1137                 return 0;
1138
1139         len = strlen(attr);
1140         for (;;) {
1141                 const char *space = strchrnul(attrs, ' ');
1142                 if (len == space - attrs && !strncmp(attrs, attr, len))
1143                         return 1;
1144                 if (!*space)
1145                         return 0;
1146                 attrs = space + 1;
1147         }
1148 }
1149
1150 static struct ref *get_refs_list(struct transport *transport, int for_push,
1151                                  const struct argv_array *ref_prefixes)
1152 {
1153         get_helper(transport);
1154
1155         if (process_connect(transport, for_push)) {
1156                 do_take_over(transport);
1157                 return transport->vtable->get_refs_list(transport, for_push, ref_prefixes);
1158         }
1159
1160         return get_refs_list_using_list(transport, for_push);
1161 }
1162
1163 static struct ref *get_refs_list_using_list(struct transport *transport,
1164                                             int for_push)
1165 {
1166         struct helper_data *data = transport->data;
1167         struct child_process *helper;
1168         struct ref *ret = NULL;
1169         struct ref **tail = &ret;
1170         struct ref *posn;
1171         struct strbuf buf = STRBUF_INIT;
1172
1173         data->get_refs_list_called = 1;
1174         helper = get_helper(transport);
1175
1176         if (data->push && for_push)
1177                 write_str_in_full(helper->in, "list for-push\n");
1178         else
1179                 write_str_in_full(helper->in, "list\n");
1180
1181         while (1) {
1182                 char *eov, *eon;
1183                 if (recvline(data, &buf))
1184                         exit(128);
1185
1186                 if (!*buf.buf)
1187                         break;
1188
1189                 eov = strchr(buf.buf, ' ');
1190                 if (!eov)
1191                         die(_("malformed response in ref list: %s"), buf.buf);
1192                 eon = strchr(eov + 1, ' ');
1193                 *eov = '\0';
1194                 if (eon)
1195                         *eon = '\0';
1196                 *tail = alloc_ref(eov + 1);
1197                 if (buf.buf[0] == '@')
1198                         (*tail)->symref = xstrdup(buf.buf + 1);
1199                 else if (buf.buf[0] != '?')
1200                         get_oid_hex(buf.buf, &(*tail)->old_oid);
1201                 if (eon) {
1202                         if (has_attribute(eon + 1, "unchanged")) {
1203                                 (*tail)->status |= REF_STATUS_UPTODATE;
1204                                 if (read_ref((*tail)->name, &(*tail)->old_oid) < 0)
1205                                         die(_("could not read ref %s"),
1206                                             (*tail)->name);
1207                         }
1208                 }
1209                 tail = &((*tail)->next);
1210         }
1211         if (debug)
1212                 fprintf(stderr, "Debug: Read ref listing.\n");
1213         strbuf_release(&buf);
1214
1215         for (posn = ret; posn; posn = posn->next)
1216                 resolve_remote_symref(posn, ret);
1217
1218         return ret;
1219 }
1220
1221 static struct transport_vtable vtable = {
1222         set_helper_option,
1223         get_refs_list,
1224         fetch,
1225         push_refs,
1226         connect_helper,
1227         release_helper
1228 };
1229
1230 int transport_helper_init(struct transport *transport, const char *name)
1231 {
1232         struct helper_data *data = xcalloc(1, sizeof(*data));
1233         data->name = name;
1234
1235         transport_check_allowed(name);
1236
1237         if (getenv("GIT_TRANSPORT_HELPER_DEBUG"))
1238                 debug = 1;
1239
1240         transport->data = data;
1241         transport->vtable = &vtable;
1242         transport->smart_options = &(data->transport_options);
1243         return 0;
1244 }
1245
1246 /*
1247  * Linux pipes can buffer 65536 bytes at once (and most platforms can
1248  * buffer less), so attempt reads and writes with up to that size.
1249  */
1250 #define BUFFERSIZE 65536
1251 /* This should be enough to hold debugging message. */
1252 #define PBUFFERSIZE 8192
1253
1254 /* Print bidirectional transfer loop debug message. */
1255 __attribute__((format (printf, 1, 2)))
1256 static void transfer_debug(const char *fmt, ...)
1257 {
1258         /*
1259          * NEEDSWORK: This function is sometimes used from multiple threads, and
1260          * we end up using debug_enabled racily. That "should not matter" since
1261          * we always write the same value, but it's still wrong. This function
1262          * is listed in .tsan-suppressions for the time being.
1263          */
1264
1265         va_list args;
1266         char msgbuf[PBUFFERSIZE];
1267         static int debug_enabled = -1;
1268
1269         if (debug_enabled < 0)
1270                 debug_enabled = getenv("GIT_TRANSLOOP_DEBUG") ? 1 : 0;
1271         if (!debug_enabled)
1272                 return;
1273
1274         va_start(args, fmt);
1275         vsnprintf(msgbuf, PBUFFERSIZE, fmt, args);
1276         va_end(args);
1277         fprintf(stderr, "Transfer loop debugging: %s\n", msgbuf);
1278 }
1279
1280 /* Stream state: More data may be coming in this direction. */
1281 #define SSTATE_TRANSFERRING 0
1282 /*
1283  * Stream state: No more data coming in this direction, flushing rest of
1284  * data.
1285  */
1286 #define SSTATE_FLUSHING 1
1287 /* Stream state: Transfer in this direction finished. */
1288 #define SSTATE_FINISHED 2
1289
1290 #define STATE_NEEDS_READING(state) ((state) <= SSTATE_TRANSFERRING)
1291 #define STATE_NEEDS_WRITING(state) ((state) <= SSTATE_FLUSHING)
1292 #define STATE_NEEDS_CLOSING(state) ((state) == SSTATE_FLUSHING)
1293
1294 /* Unidirectional transfer. */
1295 struct unidirectional_transfer {
1296         /* Source */
1297         int src;
1298         /* Destination */
1299         int dest;
1300         /* Is source socket? */
1301         int src_is_sock;
1302         /* Is destination socket? */
1303         int dest_is_sock;
1304         /* Transfer state (TRANSFERRING/FLUSHING/FINISHED) */
1305         int state;
1306         /* Buffer. */
1307         char buf[BUFFERSIZE];
1308         /* Buffer used. */
1309         size_t bufuse;
1310         /* Name of source. */
1311         const char *src_name;
1312         /* Name of destination. */
1313         const char *dest_name;
1314 };
1315
1316 /* Closes the target (for writing) if transfer has finished. */
1317 static void udt_close_if_finished(struct unidirectional_transfer *t)
1318 {
1319         if (STATE_NEEDS_CLOSING(t->state) && !t->bufuse) {
1320                 t->state = SSTATE_FINISHED;
1321                 if (t->dest_is_sock)
1322                         shutdown(t->dest, SHUT_WR);
1323                 else
1324                         close(t->dest);
1325                 transfer_debug("Closed %s.", t->dest_name);
1326         }
1327 }
1328
1329 /*
1330  * Tries to read data from source into buffer. If buffer is full,
1331  * no data is read. Returns 0 on success, -1 on error.
1332  */
1333 static int udt_do_read(struct unidirectional_transfer *t)
1334 {
1335         ssize_t bytes;
1336
1337         if (t->bufuse == BUFFERSIZE)
1338                 return 0;       /* No space for more. */
1339
1340         transfer_debug("%s is readable", t->src_name);
1341         bytes = xread(t->src, t->buf + t->bufuse, BUFFERSIZE - t->bufuse);
1342         if (bytes < 0) {
1343                 error_errno(_("read(%s) failed"), t->src_name);
1344                 return -1;
1345         } else if (bytes == 0) {
1346                 transfer_debug("%s EOF (with %i bytes in buffer)",
1347                         t->src_name, (int)t->bufuse);
1348                 t->state = SSTATE_FLUSHING;
1349         } else if (bytes > 0) {
1350                 t->bufuse += bytes;
1351                 transfer_debug("Read %i bytes from %s (buffer now at %i)",
1352                         (int)bytes, t->src_name, (int)t->bufuse);
1353         }
1354         return 0;
1355 }
1356
1357 /* Tries to write data from buffer into destination. If buffer is empty,
1358  * no data is written. Returns 0 on success, -1 on error.
1359  */
1360 static int udt_do_write(struct unidirectional_transfer *t)
1361 {
1362         ssize_t bytes;
1363
1364         if (t->bufuse == 0)
1365                 return 0;       /* Nothing to write. */
1366
1367         transfer_debug("%s is writable", t->dest_name);
1368         bytes = xwrite(t->dest, t->buf, t->bufuse);
1369         if (bytes < 0) {
1370                 error_errno(_("write(%s) failed"), t->dest_name);
1371                 return -1;
1372         } else if (bytes > 0) {
1373                 t->bufuse -= bytes;
1374                 if (t->bufuse)
1375                         memmove(t->buf, t->buf + bytes, t->bufuse);
1376                 transfer_debug("Wrote %i bytes to %s (buffer now at %i)",
1377                         (int)bytes, t->dest_name, (int)t->bufuse);
1378         }
1379         return 0;
1380 }
1381
1382
1383 /* State of bidirectional transfer loop. */
1384 struct bidirectional_transfer_state {
1385         /* Direction from program to git. */
1386         struct unidirectional_transfer ptg;
1387         /* Direction from git to program. */
1388         struct unidirectional_transfer gtp;
1389 };
1390
1391 static void *udt_copy_task_routine(void *udt)
1392 {
1393         struct unidirectional_transfer *t = (struct unidirectional_transfer *)udt;
1394         while (t->state != SSTATE_FINISHED) {
1395                 if (STATE_NEEDS_READING(t->state))
1396                         if (udt_do_read(t))
1397                                 return NULL;
1398                 if (STATE_NEEDS_WRITING(t->state))
1399                         if (udt_do_write(t))
1400                                 return NULL;
1401                 if (STATE_NEEDS_CLOSING(t->state))
1402                         udt_close_if_finished(t);
1403         }
1404         return udt;     /* Just some non-NULL value. */
1405 }
1406
1407 #ifndef NO_PTHREADS
1408
1409 /*
1410  * Join thread, with appropriate errors on failure. Name is name for the
1411  * thread (for error messages). Returns 0 on success, 1 on failure.
1412  */
1413 static int tloop_join(pthread_t thread, const char *name)
1414 {
1415         int err;
1416         void *tret;
1417         err = pthread_join(thread, &tret);
1418         if (!tret) {
1419                 error(_("%s thread failed"), name);
1420                 return 1;
1421         }
1422         if (err) {
1423                 error(_("%s thread failed to join: %s"), name, strerror(err));
1424                 return 1;
1425         }
1426         return 0;
1427 }
1428
1429 /*
1430  * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1431  * -1 on failure.
1432  */
1433 static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1434 {
1435         pthread_t gtp_thread;
1436         pthread_t ptg_thread;
1437         int err;
1438         int ret = 0;
1439         err = pthread_create(&gtp_thread, NULL, udt_copy_task_routine,
1440                 &s->gtp);
1441         if (err)
1442                 die(_("can't start thread for copying data: %s"), strerror(err));
1443         err = pthread_create(&ptg_thread, NULL, udt_copy_task_routine,
1444                 &s->ptg);
1445         if (err)
1446                 die(_("can't start thread for copying data: %s"), strerror(err));
1447
1448         ret |= tloop_join(gtp_thread, "Git to program copy");
1449         ret |= tloop_join(ptg_thread, "Program to git copy");
1450         return ret;
1451 }
1452 #else
1453
1454 /* Close the source and target (for writing) for transfer. */
1455 static void udt_kill_transfer(struct unidirectional_transfer *t)
1456 {
1457         t->state = SSTATE_FINISHED;
1458         /*
1459          * Socket read end left open isn't a disaster if nobody
1460          * attempts to read from it (mingw compat headers do not
1461          * have SHUT_RD)...
1462          *
1463          * We can't fully close the socket since otherwise gtp
1464          * task would first close the socket it sends data to
1465          * while closing the ptg file descriptors.
1466          */
1467         if (!t->src_is_sock)
1468                 close(t->src);
1469         if (t->dest_is_sock)
1470                 shutdown(t->dest, SHUT_WR);
1471         else
1472                 close(t->dest);
1473 }
1474
1475 /*
1476  * Join process, with appropriate errors on failure. Name is name for the
1477  * process (for error messages). Returns 0 on success, 1 on failure.
1478  */
1479 static int tloop_join(pid_t pid, const char *name)
1480 {
1481         int tret;
1482         if (waitpid(pid, &tret, 0) < 0) {
1483                 error_errno(_("%s process failed to wait"), name);
1484                 return 1;
1485         }
1486         if (!WIFEXITED(tret) || WEXITSTATUS(tret)) {
1487                 error(_("%s process failed"), name);
1488                 return 1;
1489         }
1490         return 0;
1491 }
1492
1493 /*
1494  * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1495  * -1 on failure.
1496  */
1497 static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1498 {
1499         pid_t pid1, pid2;
1500         int ret = 0;
1501
1502         /* Fork thread #1: git to program. */
1503         pid1 = fork();
1504         if (pid1 < 0)
1505                 die_errno(_("can't start thread for copying data"));
1506         else if (pid1 == 0) {
1507                 udt_kill_transfer(&s->ptg);
1508                 exit(udt_copy_task_routine(&s->gtp) ? 0 : 1);
1509         }
1510
1511         /* Fork thread #2: program to git. */
1512         pid2 = fork();
1513         if (pid2 < 0)
1514                 die_errno(_("can't start thread for copying data"));
1515         else if (pid2 == 0) {
1516                 udt_kill_transfer(&s->gtp);
1517                 exit(udt_copy_task_routine(&s->ptg) ? 0 : 1);
1518         }
1519
1520         /*
1521          * Close both streams in parent as to not interfere with
1522          * end of file detection and wait for both tasks to finish.
1523          */
1524         udt_kill_transfer(&s->gtp);
1525         udt_kill_transfer(&s->ptg);
1526         ret |= tloop_join(pid1, "Git to program copy");
1527         ret |= tloop_join(pid2, "Program to git copy");
1528         return ret;
1529 }
1530 #endif
1531
1532 /*
1533  * Copies data from stdin to output and from input to stdout simultaneously.
1534  * Additionally filtering through given filter. If filter is NULL, uses
1535  * identity filter.
1536  */
1537 int bidirectional_transfer_loop(int input, int output)
1538 {
1539         struct bidirectional_transfer_state state;
1540
1541         /* Fill the state fields. */
1542         state.ptg.src = input;
1543         state.ptg.dest = 1;
1544         state.ptg.src_is_sock = (input == output);
1545         state.ptg.dest_is_sock = 0;
1546         state.ptg.state = SSTATE_TRANSFERRING;
1547         state.ptg.bufuse = 0;
1548         state.ptg.src_name = "remote input";
1549         state.ptg.dest_name = "stdout";
1550
1551         state.gtp.src = 0;
1552         state.gtp.dest = output;
1553         state.gtp.src_is_sock = 0;
1554         state.gtp.dest_is_sock = (input == output);
1555         state.gtp.state = SSTATE_TRANSFERRING;
1556         state.gtp.bufuse = 0;
1557         state.gtp.src_name = "stdin";
1558         state.gtp.dest_name = "remote output";
1559
1560         return tloop_spawnwait_tasks(&state);
1561 }
1562
1563 void reject_atomic_push(struct ref *remote_refs, int mirror_mode)
1564 {
1565         struct ref *ref;
1566
1567         /* Mark other refs as failed */
1568         for (ref = remote_refs; ref; ref = ref->next) {
1569                 if (!ref->peer_ref && !mirror_mode)
1570                         continue;
1571
1572                 switch (ref->status) {
1573                 case REF_STATUS_NONE:
1574                 case REF_STATUS_OK:
1575                 case REF_STATUS_EXPECTING_REPORT:
1576                         ref->status = REF_STATUS_ATOMIC_PUSH_FAILED;
1577                         continue;
1578                 default:
1579                         break; /* do nothing */
1580                 }
1581         }
1582         return;
1583 }