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