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