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 "quote.h"
   9 #include "remote.h"
  10 #include "string-list.h"
  11 #include "thread-utils.h"
  12 #include "sigchain.h"
  13 #include "argv-array.h"
  14 #include "refs.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                 signed_tags : 1,
  30                 check_connectivity : 1,
  31                 no_disconnect_req : 1,
  32                 no_private_update : 1;
  33         char *export_marks;
  34         char *import_marks;
  35         /* These go from remote name (as in "list") to private name */
  36         struct refspec *refspecs;
  37         int refspec_nr;
  38         /* Transport options for fetch-pack/send-pack (should one of
  39          * those be invoked).
  40          */
  41         struct git_transport_options transport_options;
  42 };
  43
  44 static void sendline(struct helper_data *helper, struct strbuf *buffer)
  45 {
  46         if (debug)
  47                 fprintf(stderr, "Debug: Remote helper: -> %s", buffer->buf);
  48         if (write_in_full(helper->helper->in, buffer->buf, buffer->len)
  49                 != buffer->len)
  50                 die_errno("Full write to remote helper failed");
  51 }
  52
  53 static int recvline_fh(FILE *helper, struct strbuf *buffer, const char *name)
  54 {
  55         strbuf_reset(buffer);
  56         if (debug)
  57                 fprintf(stderr, "Debug: Remote helper: Waiting...\n");
  58         if (strbuf_getline(buffer, helper, '\n') == 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, helper->name);
  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)) != strlen(str))
  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 struct child_process *get_helper(struct transport *transport)
 102 {
 103         struct helper_data *data = transport->data;
 104         struct strbuf buf = STRBUF_INIT;
 105         struct child_process *helper;
 106         const char **refspecs = NULL;
 107         int refspec_nr = 0;
 108         int refspec_alloc = 0;
 109         int duped;
 110         int code;
 111
 112         if (data->helper)
 113                 return data->helper;
 114
 115         helper = xmalloc(sizeof(*helper));
 116         child_process_init(helper);
 117         helper->in = -1;
 118         helper->out = -1;
 119         helper->err = 0;
 120         argv_array_pushf(&helper->args, "git-remote-%s", data->name);
 121         argv_array_push(&helper->args, transport->remote->name);
 122         argv_array_push(&helper->args, remove_ext_force(transport->url));
 123         helper->git_cmd = 0;
 124         helper->silent_exec_failure = 1;
 125
 126         argv_array_pushf(&helper->env_array, "%s=%s", GIT_DIR_ENVIRONMENT,
 127                          get_git_dir());
 128
 129         code = start_command(helper);
 130         if (code < 0 && errno == ENOENT)
 131                 die("Unable to find remote helper for '%s'", data->name);
 132         else if (code != 0)
 133                 exit(code);
 134
 135         data->helper = helper;
 136         data->no_disconnect_req = 0;
 137
 138         /*
 139          * Open the output as FILE* so strbuf_getline() can be used.
 140          * Do this with duped fd because fclose() will close the fd,
 141          * and stuff like taking over will require the fd to remain.
 142          */
 143         duped = dup(helper->out);
 144         if (duped < 0)
 145                 die_errno("Can't dup helper output fd");
 146         data->out = xfdopen(duped, "r");
 147
 148         write_constant(helper->in, "capabilities\n");
 149
 150         while (1) {
 151                 const char *capname, *arg;
 152                 int mandatory = 0;
 153                 if (recvline(data, &buf))
 154                         exit(128);
 155
 156                 if (!*buf.buf)
 157                         break;
 158
 159                 if (*buf.buf == '*') {
 160                         capname = buf.buf + 1;
 161                         mandatory = 1;
 162                 } else
 163                         capname = buf.buf;
 164
 165                 if (debug)
 166                         fprintf(stderr, "Debug: Got cap %s\n", capname);
 167                 if (!strcmp(capname, "fetch"))
 168                         data->fetch = 1;
 169                 else if (!strcmp(capname, "option"))
 170                         data->option = 1;
 171                 else if (!strcmp(capname, "push"))
 172                         data->push = 1;
 173                 else if (!strcmp(capname, "import"))
 174                         data->import = 1;
 175                 else if (!strcmp(capname, "bidi-import"))
 176                         data->bidi_import = 1;
 177                 else if (!strcmp(capname, "export"))
 178                         data->export = 1;
 179                 else if (!strcmp(capname, "check-connectivity"))
 180                         data->check_connectivity = 1;
 181                 else if (!data->refspecs && skip_prefix(capname, "refspec ", &arg)) {
 182                         ALLOC_GROW(refspecs,
 183                                    refspec_nr + 1,
 184                                    refspec_alloc);
 185                         refspecs[refspec_nr++] = xstrdup(arg);
 186                 } else if (!strcmp(capname, "connect")) {
 187                         data->connect = 1;
 188                 } else if (!strcmp(capname, "signed-tags")) {
 189                         data->signed_tags = 1;
 190                 } else if (skip_prefix(capname, "export-marks ", &arg)) {
 191                         data->export_marks = xstrdup(arg);
 192                 } else if (skip_prefix(capname, "import-marks ", &arg)) {
 193                         data->import_marks = xstrdup(arg);
 194                 } else if (starts_with(capname, "no-private-update")) {
 195                         data->no_private_update = 1;
 196                 } else if (mandatory) {
 197                         die("Unknown mandatory capability %s. This remote "
 198                             "helper probably needs newer version of Git.",
 199                             capname);
 200                 }
 201         }
 202         if (refspecs) {
 203                 int i;
 204                 data->refspec_nr = refspec_nr;
 205                 data->refspecs = parse_fetch_refspec(refspec_nr, refspecs);
 206                 for (i = 0; i < refspec_nr; i++)
 207                         free((char *)refspecs[i]);
 208                 free(refspecs);
 209         } else if (data->import || data->bidi_import || data->export) {
 210                 warning("This remote helper should implement refspec capability.");
 211         }
 212         strbuf_release(&buf);
 213         if (debug)
 214                 fprintf(stderr, "Debug: Capabilities complete.\n");
 215         return data->helper;
 216 }
 217
 218 static int disconnect_helper(struct transport *transport)
 219 {
 220         struct helper_data *data = transport->data;
 221         int res = 0;
 222
 223         if (data->helper) {
 224                 if (debug)
 225                         fprintf(stderr, "Debug: Disconnecting.\n");
 226                 if (!data->no_disconnect_req) {
 227                         /*
 228                          * Ignore write errors; there's nothing we can do,
 229                          * since we're about to close the pipe anyway. And the
 230                          * most likely error is EPIPE due to the helper dying
 231                          * to report an error itself.
 232                          */
 233                         sigchain_push(SIGPIPE, SIG_IGN);
 234                         xwrite(data->helper->in, "\n", 1);
 235                         sigchain_pop(SIGPIPE);
 236                 }
 237                 close(data->helper->in);
 238                 close(data->helper->out);
 239                 fclose(data->out);
 240                 res = finish_command(data->helper);
 241                 free(data->helper);
 242                 data->helper = NULL;
 243         }
 244         return res;
 245 }
 246
 247 static const char *unsupported_options[] = {
 248         TRANS_OPT_UPLOADPACK,
 249         TRANS_OPT_RECEIVEPACK,
 250         TRANS_OPT_THIN,
 251         TRANS_OPT_KEEP
 252         };
 253
 254 static const char *boolean_options[] = {
 255         TRANS_OPT_THIN,
 256         TRANS_OPT_KEEP,
 257         TRANS_OPT_FOLLOWTAGS,
 258         TRANS_OPT_PUSH_CERT
 259         };
 260
 261 static int set_helper_option(struct transport *transport,
 262                           const char *name, const char *value)
 263 {
 264         struct helper_data *data = transport->data;
 265         struct strbuf buf = STRBUF_INIT;
 266         int i, ret, is_bool = 0;
 267
 268         get_helper(transport);
 269
 270         if (!data->option)
 271                 return 1;
 272
 273         for (i = 0; i < ARRAY_SIZE(unsupported_options); i++) {
 274                 if (!strcmp(name, unsupported_options[i]))
 275                         return 1;
 276         }
 277
 278         for (i = 0; i < ARRAY_SIZE(boolean_options); i++) {
 279                 if (!strcmp(name, boolean_options[i])) {
 280                         is_bool = 1;
 281                         break;
 282                 }
 283         }
 284
 285         strbuf_addf(&buf, "option %s ", name);
 286         if (is_bool)
 287                 strbuf_addstr(&buf, value ? "true" : "false");
 288         else
 289                 quote_c_style(value, &buf, NULL, 0);
 290         strbuf_addch(&buf, '\n');
 291
 292         sendline(data, &buf);
 293         if (recvline(data, &buf))
 294                 exit(128);
 295
 296         if (!strcmp(buf.buf, "ok"))
 297                 ret = 0;
 298         else if (starts_with(buf.buf, "error")) {
 299                 ret = -1;
 300         } else if (!strcmp(buf.buf, "unsupported"))
 301                 ret = 1;
 302         else {
 303                 warning("%s unexpectedly said: '%s'", data->name, buf.buf);
 304                 ret = 1;
 305         }
 306         strbuf_release(&buf);
 307         return ret;
 308 }
 309
 310 static void standard_options(struct transport *t)
 311 {
 312         char buf[16];
 313         int n;
 314         int v = t->verbose;
 315
 316         set_helper_option(t, "progress", t->progress ? "true" : "false");
 317
 318         n = snprintf(buf, sizeof(buf), "%d", v + 1);
 319         if (n >= sizeof(buf))
 320                 die("impossibly large verbosity value");
 321         set_helper_option(t, "verbosity", buf);
 322 }
 323
 324 static int release_helper(struct transport *transport)
 325 {
 326         int res = 0;
 327         struct helper_data *data = transport->data;
 328         free_refspec(data->refspec_nr, data->refspecs);
 329         data->refspecs = NULL;
 330         res = disconnect_helper(transport);
 331         free(transport->data);
 332         return res;
 333 }
 334
 335 static int fetch_with_fetch(struct transport *transport,
 336                             int nr_heads, struct ref **to_fetch)
 337 {
 338         struct helper_data *data = transport->data;
 339         int i;
 340         struct strbuf buf = STRBUF_INIT;
 341
 342         standard_options(transport);
 343         if (data->check_connectivity &&
 344             data->transport_options.check_self_contained_and_connected)
 345                 set_helper_option(transport, "check-connectivity", "true");
 346
 347         if (transport->cloning)
 348                 set_helper_option(transport, "cloning", "true");
 349
 350         if (data->transport_options.update_shallow)
 351                 set_helper_option(transport, "update-shallow", "true");
 352
 353         for (i = 0; i < nr_heads; i++) {
 354                 const struct ref *posn = to_fetch[i];
 355                 if (posn->status & REF_STATUS_UPTODATE)
 356                         continue;
 357
 358                 strbuf_addf(&buf, "fetch %s %s\n",
 359                             sha1_to_hex(posn->old_sha1), posn->name);
 360         }
 361
 362         strbuf_addch(&buf, '\n');
 363         sendline(data, &buf);
 364
 365         while (1) {
 366                 if (recvline(data, &buf))
 367                         exit(128);
 368
 369                 if (starts_with(buf.buf, "lock ")) {
 370                         const char *name = buf.buf + 5;
 371                         if (transport->pack_lockfile)
 372                                 warning("%s also locked %s", data->name, name);
 373                         else
 374                                 transport->pack_lockfile = xstrdup(name);
 375                 }
 376                 else if (data->check_connectivity &&
 377                          data->transport_options.check_self_contained_and_connected &&
 378                          !strcmp(buf.buf, "connectivity-ok"))
 379                         data->transport_options.self_contained_and_connected = 1;
 380                 else if (!buf.len)
 381                         break;
 382                 else
 383                         warning("%s unexpectedly said: '%s'", data->name, buf.buf);
 384         }
 385         strbuf_release(&buf);
 386         return 0;
 387 }
 388
 389 static int get_importer(struct transport *transport, struct child_process *fastimport)
 390 {
 391         struct child_process *helper = get_helper(transport);
 392         struct helper_data *data = transport->data;
 393         int cat_blob_fd, code;
 394         child_process_init(fastimport);
 395         fastimport->in = helper->out;
 396         argv_array_push(&fastimport->args, "fast-import");
 397         argv_array_push(&fastimport->args, debug ? "--stats" : "--quiet");
 398
 399         if (data->bidi_import) {
 400                 cat_blob_fd = xdup(helper->in);
 401                 argv_array_pushf(&fastimport->args, "--cat-blob-fd=%d", cat_blob_fd);
 402         }
 403         fastimport->git_cmd = 1;
 404
 405         code = start_command(fastimport);
 406         return code;
 407 }
 408
 409 static int get_exporter(struct transport *transport,
 410                         struct child_process *fastexport,
 411                         struct string_list *revlist_args)
 412 {
 413         struct helper_data *data = transport->data;
 414         struct child_process *helper = get_helper(transport);
 415         int i;
 416
 417         memset(fastexport, 0, sizeof(*fastexport));
 418
 419         /* we need to duplicate helper->in because we want to use it after
 420          * fastexport is done with it. */
 421         fastexport->out = dup(helper->in);
 422         argv_array_push(&fastexport->args, "fast-export");
 423         argv_array_push(&fastexport->args, "--use-done-feature");
 424         argv_array_push(&fastexport->args, data->signed_tags ?
 425                 "--signed-tags=verbatim" : "--signed-tags=warn-strip");
 426         if (data->export_marks)
 427                 argv_array_pushf(&fastexport->args, "--export-marks=%s.tmp", data->export_marks);
 428         if (data->import_marks)
 429                 argv_array_pushf(&fastexport->args, "--import-marks=%s", data->import_marks);
 430
 431         for (i = 0; i < revlist_args->nr; i++)
 432                 argv_array_push(&fastexport->args, revlist_args->items[i].string);
 433
 434         fastexport->git_cmd = 1;
 435         return start_command(fastexport);
 436 }
 437
 438 static int fetch_with_import(struct transport *transport,
 439                              int nr_heads, struct ref **to_fetch)
 440 {
 441         struct child_process fastimport;
 442         struct helper_data *data = transport->data;
 443         int i;
 444         struct ref *posn;
 445         struct strbuf buf = STRBUF_INIT;
 446
 447         get_helper(transport);
 448
 449         if (get_importer(transport, &fastimport))
 450                 die("Couldn't run fast-import");
 451
 452         for (i = 0; i < nr_heads; i++) {
 453                 posn = to_fetch[i];
 454                 if (posn->status & REF_STATUS_UPTODATE)
 455                         continue;
 456
 457                 strbuf_addf(&buf, "import %s\n", posn->name);
 458                 sendline(data, &buf);
 459                 strbuf_reset(&buf);
 460         }
 461
 462         write_constant(data->helper->in, "\n");
 463         /*
 464          * remote-helpers that advertise the bidi-import capability are required to
 465          * buffer the complete batch of import commands until this newline before
 466          * sending data to fast-import.
 467          * These helpers read back data from fast-import on their stdin, which could
 468          * be mixed with import commands, otherwise.
 469          */
 470
 471         if (finish_command(&fastimport))
 472                 die("Error while running fast-import");
 473
 474         /*
 475          * The fast-import stream of a remote helper that advertises
 476          * the "refspec" capability writes to the refs named after the
 477          * right hand side of the first refspec matching each ref we
 478          * were fetching.
 479          *
 480          * (If no "refspec" capability was specified, for historical
 481          * reasons we default to the equivalent of *:*.)
 482          *
 483          * Store the result in to_fetch[i].old_sha1.  Callers such
 484          * as "git fetch" can use the value to write feedback to the
 485          * terminal, populate FETCH_HEAD, and determine what new value
 486          * should be written to peer_ref if the update is a
 487          * fast-forward or this is a forced update.
 488          */
 489         for (i = 0; i < nr_heads; i++) {
 490                 char *private;
 491                 posn = to_fetch[i];
 492                 if (posn->status & REF_STATUS_UPTODATE)
 493                         continue;
 494                 if (data->refspecs)
 495                         private = apply_refspecs(data->refspecs, data->refspec_nr, posn->name);
 496                 else
 497                         private = xstrdup(posn->name);
 498                 if (private) {
 499                         read_ref(private, posn->old_sha1);
 500                         free(private);
 501                 }
 502         }
 503         strbuf_release(&buf);
 504         return 0;
 505 }
 506
 507 static int process_connect_service(struct transport *transport,
 508                                    const char *name, const char *exec)
 509 {
 510         struct helper_data *data = transport->data;
 511         struct strbuf cmdbuf = STRBUF_INIT;
 512         struct child_process *helper;
 513         int r, duped, ret = 0;
 514         FILE *input;
 515
 516         helper = get_helper(transport);
 517
 518         /*
 519          * Yes, dup the pipe another time, as we need unbuffered version
 520          * of input pipe as FILE*. fclose() closes the underlying fd and
 521          * stream buffering only can be changed before first I/O operation
 522          * on it.
 523          */
 524         duped = dup(helper->out);
 525         if (duped < 0)
 526                 die_errno("Can't dup helper output fd");
 527         input = xfdopen(duped, "r");
 528         setvbuf(input, NULL, _IONBF, 0);
 529
 530         /*
 531          * Handle --upload-pack and friends. This is fire and forget...
 532          * just warn if it fails.
 533          */
 534         if (strcmp(name, exec)) {
 535                 r = set_helper_option(transport, "servpath", exec);
 536                 if (r > 0)
 537                         warning("Setting remote service path not supported by protocol.");
 538                 else if (r < 0)
 539                         warning("Invalid remote service path.");
 540         }
 541
 542         if (data->connect)
 543                 strbuf_addf(&cmdbuf, "connect %s\n", name);
 544         else
 545                 goto exit;
 546
 547         sendline(data, &cmdbuf);
 548         if (recvline_fh(input, &cmdbuf, name))
 549                 exit(128);
 550
 551         if (!strcmp(cmdbuf.buf, "")) {
 552                 data->no_disconnect_req = 1;
 553                 if (debug)
 554                         fprintf(stderr, "Debug: Smart transport connection "
 555                                 "ready.\n");
 556                 ret = 1;
 557         } else if (!strcmp(cmdbuf.buf, "fallback")) {
 558                 if (debug)
 559                         fprintf(stderr, "Debug: Falling back to dumb "
 560                                 "transport.\n");
 561         } else
 562                 die("Unknown response to connect: %s",
 563                         cmdbuf.buf);
 564
 565 exit:
 566         fclose(input);
 567         return ret;
 568 }
 569
 570 static int process_connect(struct transport *transport,
 571                                      int for_push)
 572 {
 573         struct helper_data *data = transport->data;
 574         const char *name;
 575         const char *exec;
 576
 577         name = for_push ? "git-receive-pack" : "git-upload-pack";
 578         if (for_push)
 579                 exec = data->transport_options.receivepack;
 580         else
 581                 exec = data->transport_options.uploadpack;
 582
 583         return process_connect_service(transport, name, exec);
 584 }
 585
 586 static int connect_helper(struct transport *transport, const char *name,
 587                    const char *exec, int fd[2])
 588 {
 589         struct helper_data *data = transport->data;
 590
 591         /* Get_helper so connect is inited. */
 592         get_helper(transport);
 593         if (!data->connect)
 594                 die("Operation not supported by protocol.");
 595
 596         if (!process_connect_service(transport, name, exec))
 597                 die("Can't connect to subservice %s.", name);
 598
 599         fd[0] = data->helper->out;
 600         fd[1] = data->helper->in;
 601         return 0;
 602 }
 603
 604 static int fetch(struct transport *transport,
 605                  int nr_heads, struct ref **to_fetch)
 606 {
 607         struct helper_data *data = transport->data;
 608         int i, count;
 609
 610         if (process_connect(transport, 0)) {
 611                 do_take_over(transport);
 612                 return transport->fetch(transport, nr_heads, to_fetch);
 613         }
 614
 615         count = 0;
 616         for (i = 0; i < nr_heads; i++)
 617                 if (!(to_fetch[i]->status & REF_STATUS_UPTODATE))
 618                         count++;
 619
 620         if (!count)
 621                 return 0;
 622
 623         if (data->fetch)
 624                 return fetch_with_fetch(transport, nr_heads, to_fetch);
 625
 626         if (data->import)
 627                 return fetch_with_import(transport, nr_heads, to_fetch);
 628
 629         return -1;
 630 }
 631
 632 static int push_update_ref_status(struct strbuf *buf,
 633                                    struct ref **ref,
 634                                    struct ref *remote_refs)
 635 {
 636         char *refname, *msg;
 637         int status, forced = 0;
 638
 639         if (starts_with(buf->buf, "ok ")) {
 640                 status = REF_STATUS_OK;
 641                 refname = buf->buf + 3;
 642         } else if (starts_with(buf->buf, "error ")) {
 643                 status = REF_STATUS_REMOTE_REJECT;
 644                 refname = buf->buf + 6;
 645         } else
 646                 die("expected ok/error, helper said '%s'", buf->buf);
 647
 648         msg = strchr(refname, ' ');
 649         if (msg) {
 650                 struct strbuf msg_buf = STRBUF_INIT;
 651                 const char *end;
 652
 653                 *msg++ = '\0';
 654                 if (!unquote_c_style(&msg_buf, msg, &end))
 655                         msg = strbuf_detach(&msg_buf, NULL);
 656                 else
 657                         msg = xstrdup(msg);
 658                 strbuf_release(&msg_buf);
 659
 660                 if (!strcmp(msg, "no match")) {
 661                         status = REF_STATUS_NONE;
 662                         free(msg);
 663                         msg = NULL;
 664                 }
 665                 else if (!strcmp(msg, "up to date")) {
 666                         status = REF_STATUS_UPTODATE;
 667                         free(msg);
 668                         msg = NULL;
 669                 }
 670                 else if (!strcmp(msg, "non-fast forward")) {
 671                         status = REF_STATUS_REJECT_NONFASTFORWARD;
 672                         free(msg);
 673                         msg = NULL;
 674                 }
 675                 else if (!strcmp(msg, "already exists")) {
 676                         status = REF_STATUS_REJECT_ALREADY_EXISTS;
 677                         free(msg);
 678                         msg = NULL;
 679                 }
 680                 else if (!strcmp(msg, "fetch first")) {
 681                         status = REF_STATUS_REJECT_FETCH_FIRST;
 682                         free(msg);
 683                         msg = NULL;
 684                 }
 685                 else if (!strcmp(msg, "needs force")) {
 686                         status = REF_STATUS_REJECT_NEEDS_FORCE;
 687                         free(msg);
 688                         msg = NULL;
 689                 }
 690                 else if (!strcmp(msg, "stale info")) {
 691                         status = REF_STATUS_REJECT_STALE;
 692                         free(msg);
 693                         msg = NULL;
 694                 }
 695                 else if (!strcmp(msg, "forced update")) {
 696                         forced = 1;
 697                         free(msg);
 698                         msg = NULL;
 699                 }
 700         }
 701
 702         if (*ref)
 703                 *ref = find_ref_by_name(*ref, refname);
 704         if (!*ref)
 705                 *ref = find_ref_by_name(remote_refs, refname);
 706         if (!*ref) {
 707                 warning("helper reported unexpected status of %s", refname);
 708                 return 1;
 709         }
 710
 711         if ((*ref)->status != REF_STATUS_NONE) {
 712                 /*
 713                  * Earlier, the ref was marked not to be pushed, so ignore the ref
 714                  * status reported by the remote helper if the latter is 'no match'.
 715                  */
 716                 if (status == REF_STATUS_NONE)
 717                         return 1;
 718         }
 719
 720         (*ref)->status = status;
 721         (*ref)->forced_update |= forced;
 722         (*ref)->remote_status = msg;
 723         return !(status == REF_STATUS_OK);
 724 }
 725
 726 static int push_update_refs_status(struct helper_data *data,
 727                                     struct ref *remote_refs,
 728                                     int flags)
 729 {
 730         struct strbuf buf = STRBUF_INIT;
 731         struct ref *ref = remote_refs;
 732         int ret = 0;
 733
 734         for (;;) {
 735                 char *private;
 736
 737                 if (recvline(data, &buf)) {
 738                         ret = 1;
 739                         break;
 740                 }
 741
 742                 if (!buf.len)
 743                         break;
 744
 745                 if (push_update_ref_status(&buf, &ref, remote_refs))
 746                         continue;
 747
 748                 if (flags & TRANSPORT_PUSH_DRY_RUN || !data->refspecs || data->no_private_update)
 749                         continue;
 750
 751                 /* propagate back the update to the remote namespace */
 752                 private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
 753                 if (!private)
 754                         continue;
 755                 update_ref("update by helper", private, ref->new_sha1, NULL, 0, 0);
 756                 free(private);
 757         }
 758         strbuf_release(&buf);
 759         return ret;
 760 }
 761
 762 static int push_refs_with_push(struct transport *transport,
 763                                struct ref *remote_refs, int flags)
 764 {
 765         int force_all = flags & TRANSPORT_PUSH_FORCE;
 766         int mirror = flags & TRANSPORT_PUSH_MIRROR;
 767         struct helper_data *data = transport->data;
 768         struct strbuf buf = STRBUF_INIT;
 769         struct ref *ref;
 770         struct string_list cas_options = STRING_LIST_INIT_DUP;
 771         struct string_list_item *cas_option;
 772
 773         get_helper(transport);
 774         if (!data->push)
 775                 return 1;
 776
 777         for (ref = remote_refs; ref; ref = ref->next) {
 778                 if (!ref->peer_ref && !mirror)
 779                         continue;
 780
 781                 /* Check for statuses set by set_ref_status_for_push() */
 782                 switch (ref->status) {
 783                 case REF_STATUS_REJECT_NONFASTFORWARD:
 784                 case REF_STATUS_REJECT_STALE:
 785                 case REF_STATUS_REJECT_ALREADY_EXISTS:
 786                 case REF_STATUS_UPTODATE:
 787                         continue;
 788                 default:
 789                         ; /* do nothing */
 790                 }
 791
 792                 if (force_all)
 793                         ref->force = 1;
 794
 795                 strbuf_addstr(&buf, "push ");
 796                 if (!ref->deletion) {
 797                         if (ref->force)
 798                                 strbuf_addch(&buf, '+');
 799                         if (ref->peer_ref)
 800                                 strbuf_addstr(&buf, ref->peer_ref->name);
 801                         else
 802                                 strbuf_addstr(&buf, sha1_to_hex(ref->new_sha1));
 803                 }
 804                 strbuf_addch(&buf, ':');
 805                 strbuf_addstr(&buf, ref->name);
 806                 strbuf_addch(&buf, '\n');
 807
 808                 /*
 809                  * The "--force-with-lease" options without explicit
 810                  * values to expect have already been expanded into
 811                  * the ref->old_sha1_expect[] field; we can ignore
 812                  * transport->smart_options->cas altogether and instead
 813                  * can enumerate them from the refs.
 814                  */
 815                 if (ref->expect_old_sha1) {
 816                         struct strbuf cas = STRBUF_INIT;
 817                         strbuf_addf(&cas, "%s:%s",
 818                                     ref->name, sha1_to_hex(ref->old_sha1_expect));
 819                         string_list_append(&cas_options, strbuf_detach(&cas, NULL));
 820                 }
 821         }
 822         if (buf.len == 0) {
 823                 string_list_clear(&cas_options, 0);
 824                 return 0;
 825         }
 826
 827         standard_options(transport);
 828         for_each_string_list_item(cas_option, &cas_options)
 829                 set_helper_option(transport, "cas", cas_option->string);
 830
 831         if (flags & TRANSPORT_PUSH_DRY_RUN) {
 832                 if (set_helper_option(transport, "dry-run", "true") != 0)
 833                         die("helper %s does not support dry-run", data->name);
 834         } else if (flags & TRANSPORT_PUSH_CERT) {
 835                 if (set_helper_option(transport, TRANS_OPT_PUSH_CERT, "true") != 0)
 836                         die("helper %s does not support --signed", data->name);
 837         }
 838
 839         strbuf_addch(&buf, '\n');
 840         sendline(data, &buf);
 841         strbuf_release(&buf);
 842
 843         return push_update_refs_status(data, remote_refs, flags);
 844 }
 845
 846 static int push_refs_with_export(struct transport *transport,
 847                 struct ref *remote_refs, int flags)
 848 {
 849         struct ref *ref;
 850         struct child_process *helper, exporter;
 851         struct helper_data *data = transport->data;
 852         struct string_list revlist_args = STRING_LIST_INIT_DUP;
 853         struct strbuf buf = STRBUF_INIT;
 854
 855         if (!data->refspecs)
 856                 die("remote-helper doesn't support push; refspec needed");
 857
 858         if (flags & TRANSPORT_PUSH_DRY_RUN) {
 859                 if (set_helper_option(transport, "dry-run", "true") != 0)
 860                         die("helper %s does not support dry-run", data->name);
 861         } else if (flags & TRANSPORT_PUSH_CERT) {
 862                 if (set_helper_option(transport, TRANS_OPT_PUSH_CERT, "true") != 0)
 863                         die("helper %s does not support dry-run", data->name);
 864         }
 865
 866         if (flags & TRANSPORT_PUSH_FORCE) {
 867                 if (set_helper_option(transport, "force", "true") != 0)
 868                         warning("helper %s does not support 'force'", data->name);
 869         }
 870
 871         helper = get_helper(transport);
 872
 873         write_constant(helper->in, "export\n");
 874
 875         for (ref = remote_refs; ref; ref = ref->next) {
 876                 char *private;
 877                 unsigned char sha1[20];
 878
 879                 private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
 880                 if (private && !get_sha1(private, sha1)) {
 881                         strbuf_addf(&buf, "^%s", private);
 882                         string_list_append(&revlist_args, strbuf_detach(&buf, NULL));
 883                         hashcpy(ref->old_sha1, sha1);
 884                 }
 885                 free(private);
 886
 887                 if (ref->peer_ref) {
 888                         if (strcmp(ref->name, ref->peer_ref->name)) {
 889                                 if (!ref->deletion) {
 890                                         const char *name;
 891                                         int flag;
 892
 893                                         /* Follow symbolic refs (mainly for HEAD). */
 894                                         name = resolve_ref_unsafe(
 895                                                  ref->peer_ref->name,
 896                                                  RESOLVE_REF_READING,
 897                                                  sha1, &flag);
 898                                         if (!name || !(flag & REF_ISSYMREF))
 899                                                 name = ref->peer_ref->name;
 900
 901                                         strbuf_addf(&buf, "%s:%s", name, ref->name);
 902                                 } else
 903                                         strbuf_addf(&buf, ":%s", ref->name);
 904
 905                                 string_list_append(&revlist_args, "--refspec");
 906                                 string_list_append(&revlist_args, buf.buf);
 907                                 strbuf_release(&buf);
 908                         }
 909                         if (!ref->deletion)
 910                                 string_list_append(&revlist_args, ref->peer_ref->name);
 911                 }
 912         }
 913
 914         if (get_exporter(transport, &exporter, &revlist_args))
 915                 die("Couldn't run fast-export");
 916
 917         string_list_clear(&revlist_args, 1);
 918
 919         if (finish_command(&exporter))
 920                 die("Error while running fast-export");
 921         if (push_update_refs_status(data, remote_refs, flags))
 922                 return 1;
 923
 924         if (data->export_marks) {
 925                 strbuf_addf(&buf, "%s.tmp", data->export_marks);
 926                 rename(buf.buf, data->export_marks);
 927                 strbuf_release(&buf);
 928         }
 929
 930         return 0;
 931 }
 932
 933 static int push_refs(struct transport *transport,
 934                 struct ref *remote_refs, int flags)
 935 {
 936         struct helper_data *data = transport->data;
 937
 938         if (process_connect(transport, 1)) {
 939                 do_take_over(transport);
 940                 return transport->push_refs(transport, remote_refs, flags);
 941         }
 942
 943         if (!remote_refs) {
 944                 fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
 945                         "Perhaps you should specify a branch such as 'master'.\n");
 946                 return 0;
 947         }
 948
 949         if (data->push)
 950                 return push_refs_with_push(transport, remote_refs, flags);
 951
 952         if (data->export)
 953                 return push_refs_with_export(transport, remote_refs, flags);
 954
 955         return -1;
 956 }
 957
 958
 959 static int has_attribute(const char *attrs, const char *attr) {
 960         int len;
 961         if (!attrs)
 962                 return 0;
 963
 964         len = strlen(attr);
 965         for (;;) {
 966                 const char *space = strchrnul(attrs, ' ');
 967                 if (len == space - attrs && !strncmp(attrs, attr, len))
 968                         return 1;
 969                 if (!*space)
 970                         return 0;
 971                 attrs = space + 1;
 972         }
 973 }
 974
 975 static struct ref *get_refs_list(struct transport *transport, int for_push)
 976 {
 977         struct helper_data *data = transport->data;
 978         struct child_process *helper;
 979         struct ref *ret = NULL;
 980         struct ref **tail = &ret;
 981         struct ref *posn;
 982         struct strbuf buf = STRBUF_INIT;
 983
 984         helper = get_helper(transport);
 985
 986         if (process_connect(transport, for_push)) {
 987                 do_take_over(transport);
 988                 return transport->get_refs_list(transport, for_push);
 989         }
 990
 991         if (data->push && for_push)
 992                 write_str_in_full(helper->in, "list for-push\n");
 993         else
 994                 write_str_in_full(helper->in, "list\n");
 995
 996         while (1) {
 997                 char *eov, *eon;
 998                 if (recvline(data, &buf))
 999                         exit(128);
1000
1001                 if (!*buf.buf)
1002                         break;
1003
1004                 eov = strchr(buf.buf, ' ');
1005                 if (!eov)
1006                         die("Malformed response in ref list: %s", buf.buf);
1007                 eon = strchr(eov + 1, ' ');
1008                 *eov = '\0';
1009                 if (eon)
1010                         *eon = '\0';
1011                 *tail = alloc_ref(eov + 1);
1012                 if (buf.buf[0] == '@')
1013                         (*tail)->symref = xstrdup(buf.buf + 1);
1014                 else if (buf.buf[0] != '?')
1015                         get_sha1_hex(buf.buf, (*tail)->old_sha1);
1016                 if (eon) {
1017                         if (has_attribute(eon + 1, "unchanged")) {
1018                                 (*tail)->status |= REF_STATUS_UPTODATE;
1019                                 read_ref((*tail)->name, (*tail)->old_sha1);
1020                         }
1021                 }
1022                 tail = &((*tail)->next);
1023         }
1024         if (debug)
1025                 fprintf(stderr, "Debug: Read ref listing.\n");
1026         strbuf_release(&buf);
1027
1028         for (posn = ret; posn; posn = posn->next)
1029                 resolve_remote_symref(posn, ret);
1030
1031         return ret;
1032 }
1033
1034 int transport_helper_init(struct transport *transport, const char *name)
1035 {
1036         struct helper_data *data = xcalloc(1, sizeof(*data));
1037         data->name = name;
1038
1039         if (getenv("GIT_TRANSPORT_HELPER_DEBUG"))
1040                 debug = 1;
1041
1042         transport->data = data;
1043         transport->set_option = set_helper_option;
1044         transport->get_refs_list = get_refs_list;
1045         transport->fetch = fetch;
1046         transport->push_refs = push_refs;
1047         transport->disconnect = release_helper;
1048         transport->connect = connect_helper;
1049         transport->smart_options = &(data->transport_options);
1050         return 0;
1051 }
1052
1053 /*
1054  * Linux pipes can buffer 65536 bytes at once (and most platforms can
1055  * buffer less), so attempt reads and writes with up to that size.
1056  */
1057 #define BUFFERSIZE 65536
1058 /* This should be enough to hold debugging message. */
1059 #define PBUFFERSIZE 8192
1060
1061 /* Print bidirectional transfer loop debug message. */
1062 __attribute__((format (printf, 1, 2)))
1063 static void transfer_debug(const char *fmt, ...)
1064 {
1065         va_list args;
1066         char msgbuf[PBUFFERSIZE];
1067         static int debug_enabled = -1;
1068
1069         if (debug_enabled < 0)
1070                 debug_enabled = getenv("GIT_TRANSLOOP_DEBUG") ? 1 : 0;
1071         if (!debug_enabled)
1072                 return;
1073
1074         va_start(args, fmt);
1075         vsnprintf(msgbuf, PBUFFERSIZE, fmt, args);
1076         va_end(args);
1077         fprintf(stderr, "Transfer loop debugging: %s\n", msgbuf);
1078 }
1079
1080 /* Stream state: More data may be coming in this direction. */
1081 #define SSTATE_TRANSFERING 0
1082 /*
1083  * Stream state: No more data coming in this direction, flushing rest of
1084  * data.
1085  */
1086 #define SSTATE_FLUSHING 1
1087 /* Stream state: Transfer in this direction finished. */
1088 #define SSTATE_FINISHED 2
1089
1090 #define STATE_NEEDS_READING(state) ((state) <= SSTATE_TRANSFERING)
1091 #define STATE_NEEDS_WRITING(state) ((state) <= SSTATE_FLUSHING)
1092 #define STATE_NEEDS_CLOSING(state) ((state) == SSTATE_FLUSHING)
1093
1094 /* Unidirectional transfer. */
1095 struct unidirectional_transfer {
1096         /* Source */
1097         int src;
1098         /* Destination */
1099         int dest;
1100         /* Is source socket? */
1101         int src_is_sock;
1102         /* Is destination socket? */
1103         int dest_is_sock;
1104         /* Transfer state (TRANSFERRING/FLUSHING/FINISHED) */
1105         int state;
1106         /* Buffer. */
1107         char buf[BUFFERSIZE];
1108         /* Buffer used. */
1109         size_t bufuse;
1110         /* Name of source. */
1111         const char *src_name;
1112         /* Name of destination. */
1113         const char *dest_name;
1114 };
1115
1116 /* Closes the target (for writing) if transfer has finished. */
1117 static void udt_close_if_finished(struct unidirectional_transfer *t)
1118 {
1119         if (STATE_NEEDS_CLOSING(t->state) && !t->bufuse) {
1120                 t->state = SSTATE_FINISHED;
1121                 if (t->dest_is_sock)
1122                         shutdown(t->dest, SHUT_WR);
1123                 else
1124                         close(t->dest);
1125                 transfer_debug("Closed %s.", t->dest_name);
1126         }
1127 }
1128
1129 /*
1130  * Tries to read read data from source into buffer. If buffer is full,
1131  * no data is read. Returns 0 on success, -1 on error.
1132  */
1133 static int udt_do_read(struct unidirectional_transfer *t)
1134 {
1135         ssize_t bytes;
1136
1137         if (t->bufuse == BUFFERSIZE)
1138                 return 0;       /* No space for more. */
1139
1140         transfer_debug("%s is readable", t->src_name);
1141         bytes = read(t->src, t->buf + t->bufuse, BUFFERSIZE - t->bufuse);
1142         if (bytes < 0 && errno != EWOULDBLOCK && errno != EAGAIN &&
1143                 errno != EINTR) {
1144                 error("read(%s) failed: %s", t->src_name, strerror(errno));
1145                 return -1;
1146         } else if (bytes == 0) {
1147                 transfer_debug("%s EOF (with %i bytes in buffer)",
1148                         t->src_name, (int)t->bufuse);
1149                 t->state = SSTATE_FLUSHING;
1150         } else if (bytes > 0) {
1151                 t->bufuse += bytes;
1152                 transfer_debug("Read %i bytes from %s (buffer now at %i)",
1153                         (int)bytes, t->src_name, (int)t->bufuse);
1154         }
1155         return 0;
1156 }
1157
1158 /* Tries to write data from buffer into destination. If buffer is empty,
1159  * no data is written. Returns 0 on success, -1 on error.
1160  */
1161 static int udt_do_write(struct unidirectional_transfer *t)
1162 {
1163         ssize_t bytes;
1164
1165         if (t->bufuse == 0)
1166                 return 0;       /* Nothing to write. */
1167
1168         transfer_debug("%s is writable", t->dest_name);
1169         bytes = xwrite(t->dest, t->buf, t->bufuse);
1170         if (bytes < 0 && errno != EWOULDBLOCK) {
1171                 error("write(%s) failed: %s", t->dest_name, strerror(errno));
1172                 return -1;
1173         } else if (bytes > 0) {
1174                 t->bufuse -= bytes;
1175                 if (t->bufuse)
1176                         memmove(t->buf, t->buf + bytes, t->bufuse);
1177                 transfer_debug("Wrote %i bytes to %s (buffer now at %i)",
1178                         (int)bytes, t->dest_name, (int)t->bufuse);
1179         }
1180         return 0;
1181 }
1182
1183
1184 /* State of bidirectional transfer loop. */
1185 struct bidirectional_transfer_state {
1186         /* Direction from program to git. */
1187         struct unidirectional_transfer ptg;
1188         /* Direction from git to program. */
1189         struct unidirectional_transfer gtp;
1190 };
1191
1192 static void *udt_copy_task_routine(void *udt)
1193 {
1194         struct unidirectional_transfer *t = (struct unidirectional_transfer *)udt;
1195         while (t->state != SSTATE_FINISHED) {
1196                 if (STATE_NEEDS_READING(t->state))
1197                         if (udt_do_read(t))
1198                                 return NULL;
1199                 if (STATE_NEEDS_WRITING(t->state))
1200                         if (udt_do_write(t))
1201                                 return NULL;
1202                 if (STATE_NEEDS_CLOSING(t->state))
1203                         udt_close_if_finished(t);
1204         }
1205         return udt;     /* Just some non-NULL value. */
1206 }
1207
1208 #ifndef NO_PTHREADS
1209
1210 /*
1211  * Join thread, with appropriate errors on failure. Name is name for the
1212  * thread (for error messages). Returns 0 on success, 1 on failure.
1213  */
1214 static int tloop_join(pthread_t thread, const char *name)
1215 {
1216         int err;
1217         void *tret;
1218         err = pthread_join(thread, &tret);
1219         if (!tret) {
1220                 error("%s thread failed", name);
1221                 return 1;
1222         }
1223         if (err) {
1224                 error("%s thread failed to join: %s", name, strerror(err));
1225                 return 1;
1226         }
1227         return 0;
1228 }
1229
1230 /*
1231  * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1232  * -1 on failure.
1233  */
1234 static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1235 {
1236         pthread_t gtp_thread;
1237         pthread_t ptg_thread;
1238         int err;
1239         int ret = 0;
1240         err = pthread_create(&gtp_thread, NULL, udt_copy_task_routine,
1241                 &s->gtp);
1242         if (err)
1243                 die("Can't start thread for copying data: %s", strerror(err));
1244         err = pthread_create(&ptg_thread, NULL, udt_copy_task_routine,
1245                 &s->ptg);
1246         if (err)
1247                 die("Can't start thread for copying data: %s", strerror(err));
1248
1249         ret |= tloop_join(gtp_thread, "Git to program copy");
1250         ret |= tloop_join(ptg_thread, "Program to git copy");
1251         return ret;
1252 }
1253 #else
1254
1255 /* Close the source and target (for writing) for transfer. */
1256 static void udt_kill_transfer(struct unidirectional_transfer *t)
1257 {
1258         t->state = SSTATE_FINISHED;
1259         /*
1260          * Socket read end left open isn't a disaster if nobody
1261          * attempts to read from it (mingw compat headers do not
1262          * have SHUT_RD)...
1263          *
1264          * We can't fully close the socket since otherwise gtp
1265          * task would first close the socket it sends data to
1266          * while closing the ptg file descriptors.
1267          */
1268         if (!t->src_is_sock)
1269                 close(t->src);
1270         if (t->dest_is_sock)
1271                 shutdown(t->dest, SHUT_WR);
1272         else
1273                 close(t->dest);
1274 }
1275
1276 /*
1277  * Join process, with appropriate errors on failure. Name is name for the
1278  * process (for error messages). Returns 0 on success, 1 on failure.
1279  */
1280 static int tloop_join(pid_t pid, const char *name)
1281 {
1282         int tret;
1283         if (waitpid(pid, &tret, 0) < 0) {
1284                 error("%s process failed to wait: %s", name, strerror(errno));
1285                 return 1;
1286         }
1287         if (!WIFEXITED(tret) || WEXITSTATUS(tret)) {
1288                 error("%s process failed", name);
1289                 return 1;
1290         }
1291         return 0;
1292 }
1293
1294 /*
1295  * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1296  * -1 on failure.
1297  */
1298 static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1299 {
1300         pid_t pid1, pid2;
1301         int ret = 0;
1302
1303         /* Fork thread #1: git to program. */
1304         pid1 = fork();
1305         if (pid1 < 0)
1306                 die_errno("Can't start thread for copying data");
1307         else if (pid1 == 0) {
1308                 udt_kill_transfer(&s->ptg);
1309                 exit(udt_copy_task_routine(&s->gtp) ? 0 : 1);
1310         }
1311
1312         /* Fork thread #2: program to git. */
1313         pid2 = fork();
1314         if (pid2 < 0)
1315                 die_errno("Can't start thread for copying data");
1316         else if (pid2 == 0) {
1317                 udt_kill_transfer(&s->gtp);
1318                 exit(udt_copy_task_routine(&s->ptg) ? 0 : 1);
1319         }
1320
1321         /*
1322          * Close both streams in parent as to not interfere with
1323          * end of file detection and wait for both tasks to finish.
1324          */
1325         udt_kill_transfer(&s->gtp);
1326         udt_kill_transfer(&s->ptg);
1327         ret |= tloop_join(pid1, "Git to program copy");
1328         ret |= tloop_join(pid2, "Program to git copy");
1329         return ret;
1330 }
1331 #endif
1332
1333 /*
1334  * Copies data from stdin to output and from input to stdout simultaneously.
1335  * Additionally filtering through given filter. If filter is NULL, uses
1336  * identity filter.
1337  */
1338 int bidirectional_transfer_loop(int input, int output)
1339 {
1340         struct bidirectional_transfer_state state;
1341
1342         /* Fill the state fields. */
1343         state.ptg.src = input;
1344         state.ptg.dest = 1;
1345         state.ptg.src_is_sock = (input == output);
1346         state.ptg.dest_is_sock = 0;
1347         state.ptg.state = SSTATE_TRANSFERING;
1348         state.ptg.bufuse = 0;
1349         state.ptg.src_name = "remote input";
1350         state.ptg.dest_name = "stdout";
1351
1352         state.gtp.src = 0;
1353         state.gtp.dest = output;
1354         state.gtp.src_is_sock = 0;
1355         state.gtp.dest_is_sock = (input == output);
1356         state.gtp.state = SSTATE_TRANSFERING;
1357         state.gtp.bufuse = 0;
1358         state.gtp.src_name = "stdin";
1359         state.gtp.dest_name = "remote output";
1360
1361         return tloop_spawnwait_tasks(&state);
1362 }