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                 no_disconnect_req : 1;
  30         char *export_marks;
  31         char *import_marks;
  32         /* These go from remote name (as in "list") to private name */
  33         struct refspec *refspecs;
  34         int refspec_nr;
  35         /* Transport options for fetch-pack/send-pack (should one of
  36          * those be invoked).
  37          */
  38         struct git_transport_options transport_options;
  39 };
  40
  41 static void sendline(struct helper_data *helper, struct strbuf *buffer)
  42 {
  43         if (debug)
  44                 fprintf(stderr, "Debug: Remote helper: -> %s", buffer->buf);
  45         if (write_in_full(helper->helper->in, buffer->buf, buffer->len)
  46                 != buffer->len)
  47                 die_errno("Full write to remote helper failed");
  48 }
  49
  50 static int recvline_fh(FILE *helper, struct strbuf *buffer, const char *name)
  51 {
  52         strbuf_reset(buffer);
  53         if (debug)
  54                 fprintf(stderr, "Debug: Remote helper: Waiting...\n");
  55         if (strbuf_getline(buffer, helper, '\n') == EOF) {
  56                 if (debug)
  57                         fprintf(stderr, "Debug: Remote helper quit.\n");
  58                 die("Reading from helper 'git-remote-%s' failed", name);
  59         }
  60
  61         if (debug)
  62                 fprintf(stderr, "Debug: Remote helper: <- %s\n", buffer->buf);
  63         return 0;
  64 }
  65
  66 static int recvline(struct helper_data *helper, struct strbuf *buffer)
  67 {
  68         return recvline_fh(helper->out, buffer, helper->name);
  69 }
  70
  71 static void xchgline(struct helper_data *helper, struct strbuf *buffer)
  72 {
  73         sendline(helper, buffer);
  74         recvline(helper, buffer);
  75 }
  76
  77 static void write_constant(int fd, const char *str)
  78 {
  79         if (debug)
  80                 fprintf(stderr, "Debug: Remote helper: -> %s", str);
  81         if (write_in_full(fd, str, strlen(str)) != strlen(str))
  82                 die_errno("Full write to remote helper failed");
  83 }
  84
  85 static const char *remove_ext_force(const char *url)
  86 {
  87         if (url) {
  88                 const char *colon = strchr(url, ':');
  89                 if (colon && colon[1] == ':')
  90                         return colon + 2;
  91         }
  92         return url;
  93 }
  94
  95 static void do_take_over(struct transport *transport)
  96 {
  97         struct helper_data *data;
  98         data = (struct helper_data *)transport->data;
  99         transport_take_over(transport, data->helper);
 100         fclose(data->out);
 101         free(data);
 102 }
 103
 104 static struct child_process *get_helper(struct transport *transport)
 105 {
 106         struct helper_data *data = transport->data;
 107         struct argv_array argv = ARGV_ARRAY_INIT;
 108         struct strbuf buf = STRBUF_INIT;
 109         struct child_process *helper;
 110         const char **refspecs = NULL;
 111         int refspec_nr = 0;
 112         int refspec_alloc = 0;
 113         int duped;
 114         int code;
 115         char git_dir_buf[sizeof(GIT_DIR_ENVIRONMENT) + PATH_MAX + 1];
 116         const char *helper_env[] = {
 117                 git_dir_buf,
 118                 NULL
 119         };
 120
 121
 122         if (data->helper)
 123                 return data->helper;
 124
 125         helper = xcalloc(1, sizeof(*helper));
 126         helper->in = -1;
 127         helper->out = -1;
 128         helper->err = 0;
 129         argv_array_pushf(&argv, "git-remote-%s", data->name);
 130         argv_array_push(&argv, transport->remote->name);
 131         argv_array_push(&argv, remove_ext_force(transport->url));
 132         helper->argv = argv_array_detach(&argv, NULL);
 133         helper->git_cmd = 0;
 134         helper->silent_exec_failure = 1;
 135
 136         snprintf(git_dir_buf, sizeof(git_dir_buf), "%s=%s", GIT_DIR_ENVIRONMENT, get_git_dir());
 137         helper->env = helper_env;
 138
 139         code = start_command(helper);
 140         if (code < 0 && errno == ENOENT)
 141                 die("Unable to find remote helper for '%s'", data->name);
 142         else if (code != 0)
 143                 exit(code);
 144
 145         data->helper = helper;
 146         data->no_disconnect_req = 0;
 147
 148         /*
 149          * Open the output as FILE* so strbuf_getline() can be used.
 150          * Do this with duped fd because fclose() will close the fd,
 151          * and stuff like taking over will require the fd to remain.
 152          */
 153         duped = dup(helper->out);
 154         if (duped < 0)
 155                 die_errno("Can't dup helper output fd");
 156         data->out = xfdopen(duped, "r");
 157
 158         write_constant(helper->in, "capabilities\n");
 159
 160         while (1) {
 161                 const char *capname;
 162                 int mandatory = 0;
 163                 recvline(data, &buf);
 164
 165                 if (!*buf.buf)
 166                         break;
 167
 168                 if (*buf.buf == '*') {
 169                         capname = buf.buf + 1;
 170                         mandatory = 1;
 171                 } else
 172                         capname = buf.buf;
 173
 174                 if (debug)
 175                         fprintf(stderr, "Debug: Got cap %s\n", capname);
 176                 if (!strcmp(capname, "fetch"))
 177                         data->fetch = 1;
 178                 else if (!strcmp(capname, "option"))
 179                         data->option = 1;
 180                 else if (!strcmp(capname, "push"))
 181                         data->push = 1;
 182                 else if (!strcmp(capname, "import"))
 183                         data->import = 1;
 184                 else if (!strcmp(capname, "bidi-import"))
 185                         data->bidi_import = 1;
 186                 else if (!strcmp(capname, "export"))
 187                         data->export = 1;
 188                 else if (!data->refspecs && !prefixcmp(capname, "refspec ")) {
 189                         ALLOC_GROW(refspecs,
 190                                    refspec_nr + 1,
 191                                    refspec_alloc);
 192                         refspecs[refspec_nr++] = xstrdup(capname + strlen("refspec "));
 193                 } else if (!strcmp(capname, "connect")) {
 194                         data->connect = 1;
 195                 } else if (!prefixcmp(capname, "export-marks ")) {
 196                         struct strbuf arg = STRBUF_INIT;
 197                         strbuf_addstr(&arg, "--export-marks=");
 198                         strbuf_addstr(&arg, capname + strlen("export-marks "));
 199                         data->export_marks = strbuf_detach(&arg, NULL);
 200                 } else if (!prefixcmp(capname, "import-marks")) {
 201                         struct strbuf arg = STRBUF_INIT;
 202                         strbuf_addstr(&arg, "--import-marks=");
 203                         strbuf_addstr(&arg, capname + strlen("import-marks "));
 204                         data->import_marks = strbuf_detach(&arg, NULL);
 205                 } else if (mandatory) {
 206                         die("Unknown mandatory capability %s. This remote "
 207                             "helper probably needs newer version of Git.",
 208                             capname);
 209                 }
 210         }
 211         if (refspecs) {
 212                 int i;
 213                 data->refspec_nr = refspec_nr;
 214                 data->refspecs = parse_fetch_refspec(refspec_nr, refspecs);
 215                 for (i = 0; i < refspec_nr; i++) {
 216                         free((char *)refspecs[i]);
 217                 }
 218                 free(refspecs);
 219         } else if (data->import || data->bidi_import || data->export) {
 220                 warning("This remote helper should implement refspec capability.");
 221         }
 222         strbuf_release(&buf);
 223         if (debug)
 224                 fprintf(stderr, "Debug: Capabilities complete.\n");
 225         return data->helper;
 226 }
 227
 228 static int disconnect_helper(struct transport *transport)
 229 {
 230         struct helper_data *data = transport->data;
 231         int res = 0;
 232
 233         if (data->helper) {
 234                 if (debug)
 235                         fprintf(stderr, "Debug: Disconnecting.\n");
 236                 if (!data->no_disconnect_req) {
 237                         /*
 238                          * Ignore write errors; there's nothing we can do,
 239                          * since we're about to close the pipe anyway. And the
 240                          * most likely error is EPIPE due to the helper dying
 241                          * to report an error itself.
 242                          */
 243                         sigchain_push(SIGPIPE, SIG_IGN);
 244                         xwrite(data->helper->in, "\n", 1);
 245                         sigchain_pop(SIGPIPE);
 246                 }
 247                 close(data->helper->in);
 248                 close(data->helper->out);
 249                 fclose(data->out);
 250                 res = finish_command(data->helper);
 251                 argv_array_free_detached(data->helper->argv);
 252                 free(data->helper);
 253                 data->helper = NULL;
 254         }
 255         return res;
 256 }
 257
 258 static const char *unsupported_options[] = {
 259         TRANS_OPT_UPLOADPACK,
 260         TRANS_OPT_RECEIVEPACK,
 261         TRANS_OPT_THIN,
 262         TRANS_OPT_KEEP
 263         };
 264 static const char *boolean_options[] = {
 265         TRANS_OPT_THIN,
 266         TRANS_OPT_KEEP,
 267         TRANS_OPT_FOLLOWTAGS
 268         };
 269
 270 static int set_helper_option(struct transport *transport,
 271                           const char *name, const char *value)
 272 {
 273         struct helper_data *data = transport->data;
 274         struct strbuf buf = STRBUF_INIT;
 275         int i, ret, is_bool = 0;
 276
 277         get_helper(transport);
 278
 279         if (!data->option)
 280                 return 1;
 281
 282         for (i = 0; i < ARRAY_SIZE(unsupported_options); i++) {
 283                 if (!strcmp(name, unsupported_options[i]))
 284                         return 1;
 285         }
 286
 287         for (i = 0; i < ARRAY_SIZE(boolean_options); i++) {
 288                 if (!strcmp(name, boolean_options[i])) {
 289                         is_bool = 1;
 290                         break;
 291                 }
 292         }
 293
 294         strbuf_addf(&buf, "option %s ", name);
 295         if (is_bool)
 296                 strbuf_addstr(&buf, value ? "true" : "false");
 297         else
 298                 quote_c_style(value, &buf, NULL, 0);
 299         strbuf_addch(&buf, '\n');
 300
 301         xchgline(data, &buf);
 302
 303         if (!strcmp(buf.buf, "ok"))
 304                 ret = 0;
 305         else if (!prefixcmp(buf.buf, "error")) {
 306                 ret = -1;
 307         } else if (!strcmp(buf.buf, "unsupported"))
 308                 ret = 1;
 309         else {
 310                 warning("%s unexpectedly said: '%s'", data->name, buf.buf);
 311                 ret = 1;
 312         }
 313         strbuf_release(&buf);
 314         return ret;
 315 }
 316
 317 static void standard_options(struct transport *t)
 318 {
 319         char buf[16];
 320         int n;
 321         int v = t->verbose;
 322
 323         set_helper_option(t, "progress", t->progress ? "true" : "false");
 324
 325         n = snprintf(buf, sizeof(buf), "%d", v + 1);
 326         if (n >= sizeof(buf))
 327                 die("impossibly large verbosity value");
 328         set_helper_option(t, "verbosity", buf);
 329 }
 330
 331 static int release_helper(struct transport *transport)
 332 {
 333         int res = 0;
 334         struct helper_data *data = transport->data;
 335         free_refspec(data->refspec_nr, data->refspecs);
 336         data->refspecs = NULL;
 337         res = disconnect_helper(transport);
 338         free(transport->data);
 339         return res;
 340 }
 341
 342 static int fetch_with_fetch(struct transport *transport,
 343                             int nr_heads, struct ref **to_fetch)
 344 {
 345         struct helper_data *data = transport->data;
 346         int i;
 347         struct strbuf buf = STRBUF_INIT;
 348
 349         standard_options(transport);
 350
 351         for (i = 0; i < nr_heads; i++) {
 352                 const struct ref *posn = to_fetch[i];
 353                 if (posn->status & REF_STATUS_UPTODATE)
 354                         continue;
 355
 356                 strbuf_addf(&buf, "fetch %s %s\n",
 357                             sha1_to_hex(posn->old_sha1), posn->name);
 358         }
 359
 360         strbuf_addch(&buf, '\n');
 361         sendline(data, &buf);
 362
 363         while (1) {
 364                 recvline(data, &buf);
 365
 366                 if (!prefixcmp(buf.buf, "lock ")) {
 367                         const char *name = buf.buf + 5;
 368                         if (transport->pack_lockfile)
 369                                 warning("%s also locked %s", data->name, name);
 370                         else
 371                                 transport->pack_lockfile = xstrdup(name);
 372                 }
 373                 else if (!buf.len)
 374                         break;
 375                 else
 376                         warning("%s unexpectedly said: '%s'", data->name, buf.buf);
 377         }
 378         strbuf_release(&buf);
 379         return 0;
 380 }
 381
 382 static int get_importer(struct transport *transport, struct child_process *fastimport)
 383 {
 384         struct child_process *helper = get_helper(transport);
 385         struct helper_data *data = transport->data;
 386         struct argv_array argv = ARGV_ARRAY_INIT;
 387         int cat_blob_fd, code;
 388         memset(fastimport, 0, sizeof(*fastimport));
 389         fastimport->in = helper->out;
 390         argv_array_push(&argv, "fast-import");
 391         argv_array_push(&argv, debug ? "--stats" : "--quiet");
 392
 393         if (data->bidi_import) {
 394                 cat_blob_fd = xdup(helper->in);
 395                 argv_array_pushf(&argv, "--cat-blob-fd=%d", cat_blob_fd);
 396         }
 397         fastimport->argv = argv.argv;
 398         fastimport->git_cmd = 1;
 399
 400         code = start_command(fastimport);
 401         return code;
 402 }
 403
 404 static int get_exporter(struct transport *transport,
 405                         struct child_process *fastexport,
 406                         struct string_list *revlist_args)
 407 {
 408         struct helper_data *data = transport->data;
 409         struct child_process *helper = get_helper(transport);
 410         int argc = 0, i;
 411         memset(fastexport, 0, sizeof(*fastexport));
 412
 413         /* we need to duplicate helper->in because we want to use it after
 414          * fastexport is done with it. */
 415         fastexport->out = dup(helper->in);
 416         fastexport->argv = xcalloc(5 + revlist_args->nr, sizeof(*fastexport->argv));
 417         fastexport->argv[argc++] = "fast-export";
 418         fastexport->argv[argc++] = "--use-done-feature";
 419         if (data->export_marks)
 420                 fastexport->argv[argc++] = data->export_marks;
 421         if (data->import_marks)
 422                 fastexport->argv[argc++] = data->import_marks;
 423
 424         for (i = 0; i < revlist_args->nr; i++)
 425                 fastexport->argv[argc++] = revlist_args->items[i].string;
 426
 427         fastexport->git_cmd = 1;
 428         return start_command(fastexport);
 429 }
 430
 431 static int fetch_with_import(struct transport *transport,
 432                              int nr_heads, struct ref **to_fetch)
 433 {
 434         struct child_process fastimport;
 435         struct helper_data *data = transport->data;
 436         int i;
 437         struct ref *posn;
 438         struct strbuf buf = STRBUF_INIT;
 439
 440         get_helper(transport);
 441
 442         if (get_importer(transport, &fastimport))
 443                 die("Couldn't run fast-import");
 444
 445         for (i = 0; i < nr_heads; i++) {
 446                 posn = to_fetch[i];
 447                 if (posn->status & REF_STATUS_UPTODATE)
 448                         continue;
 449
 450                 strbuf_addf(&buf, "import %s\n", posn->name);
 451                 sendline(data, &buf);
 452                 strbuf_reset(&buf);
 453         }
 454
 455         write_constant(data->helper->in, "\n");
 456         /*
 457          * remote-helpers that advertise the bidi-import capability are required to
 458          * buffer the complete batch of import commands until this newline before
 459          * sending data to fast-import.
 460          * These helpers read back data from fast-import on their stdin, which could
 461          * be mixed with import commands, otherwise.
 462          */
 463
 464         if (finish_command(&fastimport))
 465                 die("Error while running fast-import");
 466         argv_array_free_detached(fastimport.argv);
 467
 468         /*
 469          * The fast-import stream of a remote helper that advertises
 470          * the "refspec" capability writes to the refs named after the
 471          * right hand side of the first refspec matching each ref we
 472          * were fetching.
 473          *
 474          * (If no "refspec" capability was specified, for historical
 475          * reasons we default to the equivalent of *:*.)
 476          *
 477          * Store the result in to_fetch[i].old_sha1.  Callers such
 478          * as "git fetch" can use the value to write feedback to the
 479          * terminal, populate FETCH_HEAD, and determine what new value
 480          * should be written to peer_ref if the update is a
 481          * fast-forward or this is a forced update.
 482          */
 483         for (i = 0; i < nr_heads; i++) {
 484                 char *private;
 485                 posn = to_fetch[i];
 486                 if (posn->status & REF_STATUS_UPTODATE)
 487                         continue;
 488                 if (data->refspecs)
 489                         private = apply_refspecs(data->refspecs, data->refspec_nr, posn->name);
 490                 else
 491                         private = xstrdup(posn->name);
 492                 if (private) {
 493                         read_ref(private, posn->old_sha1);
 494                         free(private);
 495                 }
 496         }
 497         strbuf_release(&buf);
 498         return 0;
 499 }
 500
 501 static int process_connect_service(struct transport *transport,
 502                                    const char *name, const char *exec)
 503 {
 504         struct helper_data *data = transport->data;
 505         struct strbuf cmdbuf = STRBUF_INIT;
 506         struct child_process *helper;
 507         int r, duped, ret = 0;
 508         FILE *input;
 509
 510         helper = get_helper(transport);
 511
 512         /*
 513          * Yes, dup the pipe another time, as we need unbuffered version
 514          * of input pipe as FILE*. fclose() closes the underlying fd and
 515          * stream buffering only can be changed before first I/O operation
 516          * on it.
 517          */
 518         duped = dup(helper->out);
 519         if (duped < 0)
 520                 die_errno("Can't dup helper output fd");
 521         input = xfdopen(duped, "r");
 522         setvbuf(input, NULL, _IONBF, 0);
 523
 524         /*
 525          * Handle --upload-pack and friends. This is fire and forget...
 526          * just warn if it fails.
 527          */
 528         if (strcmp(name, exec)) {
 529                 r = set_helper_option(transport, "servpath", exec);
 530                 if (r > 0)
 531                         warning("Setting remote service path not supported by protocol.");
 532                 else if (r < 0)
 533                         warning("Invalid remote service path.");
 534         }
 535
 536         if (data->connect)
 537                 strbuf_addf(&cmdbuf, "connect %s\n", name);
 538         else
 539                 goto exit;
 540
 541         sendline(data, &cmdbuf);
 542         recvline_fh(input, &cmdbuf, name);
 543         if (!strcmp(cmdbuf.buf, "")) {
 544                 data->no_disconnect_req = 1;
 545                 if (debug)
 546                         fprintf(stderr, "Debug: Smart transport connection "
 547                                 "ready.\n");
 548                 ret = 1;
 549         } else if (!strcmp(cmdbuf.buf, "fallback")) {
 550                 if (debug)
 551                         fprintf(stderr, "Debug: Falling back to dumb "
 552                                 "transport.\n");
 553         } else
 554                 die("Unknown response to connect: %s",
 555                         cmdbuf.buf);
 556
 557 exit:
 558         fclose(input);
 559         return ret;
 560 }
 561
 562 static int process_connect(struct transport *transport,
 563                                      int for_push)
 564 {
 565         struct helper_data *data = transport->data;
 566         const char *name;
 567         const char *exec;
 568
 569         name = for_push ? "git-receive-pack" : "git-upload-pack";
 570         if (for_push)
 571                 exec = data->transport_options.receivepack;
 572         else
 573                 exec = data->transport_options.uploadpack;
 574
 575         return process_connect_service(transport, name, exec);
 576 }
 577
 578 static int connect_helper(struct transport *transport, const char *name,
 579                    const char *exec, int fd[2])
 580 {
 581         struct helper_data *data = transport->data;
 582
 583         /* Get_helper so connect is inited. */
 584         get_helper(transport);
 585         if (!data->connect)
 586                 die("Operation not supported by protocol.");
 587
 588         if (!process_connect_service(transport, name, exec))
 589                 die("Can't connect to subservice %s.", name);
 590
 591         fd[0] = data->helper->out;
 592         fd[1] = data->helper->in;
 593         return 0;
 594 }
 595
 596 static int fetch(struct transport *transport,
 597                  int nr_heads, struct ref **to_fetch)
 598 {
 599         struct helper_data *data = transport->data;
 600         int i, count;
 601
 602         if (process_connect(transport, 0)) {
 603                 do_take_over(transport);
 604                 return transport->fetch(transport, nr_heads, to_fetch);
 605         }
 606
 607         count = 0;
 608         for (i = 0; i < nr_heads; i++)
 609                 if (!(to_fetch[i]->status & REF_STATUS_UPTODATE))
 610                         count++;
 611
 612         if (!count)
 613                 return 0;
 614
 615         if (data->fetch)
 616                 return fetch_with_fetch(transport, nr_heads, to_fetch);
 617
 618         if (data->import)
 619                 return fetch_with_import(transport, nr_heads, to_fetch);
 620
 621         return -1;
 622 }
 623
 624 static int push_update_ref_status(struct strbuf *buf,
 625                                    struct ref **ref,
 626                                    struct ref *remote_refs)
 627 {
 628         char *refname, *msg;
 629         int status;
 630
 631         if (!prefixcmp(buf->buf, "ok ")) {
 632                 status = REF_STATUS_OK;
 633                 refname = buf->buf + 3;
 634         } else if (!prefixcmp(buf->buf, "error ")) {
 635                 status = REF_STATUS_REMOTE_REJECT;
 636                 refname = buf->buf + 6;
 637         } else
 638                 die("expected ok/error, helper said '%s'", buf->buf);
 639
 640         msg = strchr(refname, ' ');
 641         if (msg) {
 642                 struct strbuf msg_buf = STRBUF_INIT;
 643                 const char *end;
 644
 645                 *msg++ = '\0';
 646                 if (!unquote_c_style(&msg_buf, msg, &end))
 647                         msg = strbuf_detach(&msg_buf, NULL);
 648                 else
 649                         msg = xstrdup(msg);
 650                 strbuf_release(&msg_buf);
 651
 652                 if (!strcmp(msg, "no match")) {
 653                         status = REF_STATUS_NONE;
 654                         free(msg);
 655                         msg = NULL;
 656                 }
 657                 else if (!strcmp(msg, "up to date")) {
 658                         status = REF_STATUS_UPTODATE;
 659                         free(msg);
 660                         msg = NULL;
 661                 }
 662                 else if (!strcmp(msg, "non-fast forward")) {
 663                         status = REF_STATUS_REJECT_NONFASTFORWARD;
 664                         free(msg);
 665                         msg = NULL;
 666                 }
 667                 else if (!strcmp(msg, "already exists")) {
 668                         status = REF_STATUS_REJECT_ALREADY_EXISTS;
 669                         free(msg);
 670                         msg = NULL;
 671                 }
 672                 else if (!strcmp(msg, "fetch first")) {
 673                         status = REF_STATUS_REJECT_FETCH_FIRST;
 674                         free(msg);
 675                         msg = NULL;
 676                 }
 677                 else if (!strcmp(msg, "needs force")) {
 678                         status = REF_STATUS_REJECT_NEEDS_FORCE;
 679                         free(msg);
 680                         msg = NULL;
 681                 }
 682         }
 683
 684         if (*ref)
 685                 *ref = find_ref_by_name(*ref, refname);
 686         if (!*ref)
 687                 *ref = find_ref_by_name(remote_refs, refname);
 688         if (!*ref) {
 689                 warning("helper reported unexpected status of %s", refname);
 690                 return 1;
 691         }
 692
 693         if ((*ref)->status != REF_STATUS_NONE) {
 694                 /*
 695                  * Earlier, the ref was marked not to be pushed, so ignore the ref
 696                  * status reported by the remote helper if the latter is 'no match'.
 697                  */
 698                 if (status == REF_STATUS_NONE)
 699                         return 1;
 700         }
 701
 702         (*ref)->status = status;
 703         (*ref)->remote_status = msg;
 704         return !(status == REF_STATUS_OK);
 705 }
 706
 707 static void push_update_refs_status(struct helper_data *data,
 708                                     struct ref *remote_refs)
 709 {
 710         struct strbuf buf = STRBUF_INIT;
 711         struct ref *ref = remote_refs;
 712         for (;;) {
 713                 char *private;
 714
 715                 recvline(data, &buf);
 716                 if (!buf.len)
 717                         break;
 718
 719                 if (push_update_ref_status(&buf, &ref, remote_refs))
 720                         continue;
 721
 722                 if (!data->refspecs)
 723                         continue;
 724
 725                 /* propagate back the update to the remote namespace */
 726                 private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
 727                 if (!private)
 728                         continue;
 729                 update_ref("update by helper", private, ref->new_sha1, NULL, 0, 0);
 730                 free(private);
 731         }
 732         strbuf_release(&buf);
 733 }
 734
 735 static int push_refs_with_push(struct transport *transport,
 736                 struct ref *remote_refs, int flags)
 737 {
 738         int force_all = flags & TRANSPORT_PUSH_FORCE;
 739         int mirror = flags & TRANSPORT_PUSH_MIRROR;
 740         struct helper_data *data = transport->data;
 741         struct strbuf buf = STRBUF_INIT;
 742         struct ref *ref;
 743
 744         get_helper(transport);
 745         if (!data->push)
 746                 return 1;
 747
 748         for (ref = remote_refs; ref; ref = ref->next) {
 749                 if (!ref->peer_ref && !mirror)
 750                         continue;
 751
 752                 /* Check for statuses set by set_ref_status_for_push() */
 753                 switch (ref->status) {
 754                 case REF_STATUS_REJECT_NONFASTFORWARD:
 755                 case REF_STATUS_REJECT_ALREADY_EXISTS:
 756                 case REF_STATUS_UPTODATE:
 757                         continue;
 758                 default:
 759                         ; /* do nothing */
 760                 }
 761
 762                 if (force_all)
 763                         ref->force = 1;
 764
 765                 strbuf_addstr(&buf, "push ");
 766                 if (!ref->deletion) {
 767                         if (ref->force)
 768                                 strbuf_addch(&buf, '+');
 769                         if (ref->peer_ref)
 770                                 strbuf_addstr(&buf, ref->peer_ref->name);
 771                         else
 772                                 strbuf_addstr(&buf, sha1_to_hex(ref->new_sha1));
 773                 }
 774                 strbuf_addch(&buf, ':');
 775                 strbuf_addstr(&buf, ref->name);
 776                 strbuf_addch(&buf, '\n');
 777         }
 778         if (buf.len == 0)
 779                 return 0;
 780
 781         standard_options(transport);
 782
 783         if (flags & TRANSPORT_PUSH_DRY_RUN) {
 784                 if (set_helper_option(transport, "dry-run", "true") != 0)
 785                         die("helper %s does not support dry-run", data->name);
 786         }
 787
 788         strbuf_addch(&buf, '\n');
 789         sendline(data, &buf);
 790         strbuf_release(&buf);
 791
 792         push_update_refs_status(data, remote_refs);
 793         return 0;
 794 }
 795
 796 static int push_refs_with_export(struct transport *transport,
 797                 struct ref *remote_refs, int flags)
 798 {
 799         struct ref *ref;
 800         struct child_process *helper, exporter;
 801         struct helper_data *data = transport->data;
 802         struct string_list revlist_args = STRING_LIST_INIT_NODUP;
 803         struct strbuf buf = STRBUF_INIT;
 804
 805         if (!data->refspecs)
 806                 die("remote-helper doesn't support push; refspec needed");
 807
 808         helper = get_helper(transport);
 809
 810         write_constant(helper->in, "export\n");
 811
 812         strbuf_reset(&buf);
 813
 814         for (ref = remote_refs; ref; ref = ref->next) {
 815                 char *private;
 816                 unsigned char sha1[20];
 817
 818                 if (ref->deletion)
 819                         die("remote-helpers do not support ref deletion");
 820
 821                 private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
 822                 if (private && !get_sha1(private, sha1)) {
 823                         strbuf_addf(&buf, "^%s", private);
 824                         string_list_append(&revlist_args, strbuf_detach(&buf, NULL));
 825                         hashcpy(ref->old_sha1, sha1);
 826                 }
 827                 free(private);
 828
 829                 if (ref->peer_ref)
 830                         string_list_append(&revlist_args, ref->peer_ref->name);
 831         }
 832
 833         if (get_exporter(transport, &exporter, &revlist_args))
 834                 die("Couldn't run fast-export");
 835
 836         if (finish_command(&exporter))
 837                 die("Error while running fast-export");
 838         push_update_refs_status(data, remote_refs);
 839         return 0;
 840 }
 841
 842 static int push_refs(struct transport *transport,
 843                 struct ref *remote_refs, int flags)
 844 {
 845         struct helper_data *data = transport->data;
 846
 847         if (process_connect(transport, 1)) {
 848                 do_take_over(transport);
 849                 return transport->push_refs(transport, remote_refs, flags);
 850         }
 851
 852         if (!remote_refs) {
 853                 fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
 854                         "Perhaps you should specify a branch such as 'master'.\n");
 855                 return 0;
 856         }
 857
 858         if (data->push)
 859                 return push_refs_with_push(transport, remote_refs, flags);
 860
 861         if (data->export)
 862                 return push_refs_with_export(transport, remote_refs, flags);
 863
 864         return -1;
 865 }
 866
 867
 868 static int has_attribute(const char *attrs, const char *attr) {
 869         int len;
 870         if (!attrs)
 871                 return 0;
 872
 873         len = strlen(attr);
 874         for (;;) {
 875                 const char *space = strchrnul(attrs, ' ');
 876                 if (len == space - attrs && !strncmp(attrs, attr, len))
 877                         return 1;
 878                 if (!*space)
 879                         return 0;
 880                 attrs = space + 1;
 881         }
 882 }
 883
 884 static struct ref *get_refs_list(struct transport *transport, int for_push)
 885 {
 886         struct helper_data *data = transport->data;
 887         struct child_process *helper;
 888         struct ref *ret = NULL;
 889         struct ref **tail = &ret;
 890         struct ref *posn;
 891         struct strbuf buf = STRBUF_INIT;
 892
 893         helper = get_helper(transport);
 894
 895         if (process_connect(transport, for_push)) {
 896                 do_take_over(transport);
 897                 return transport->get_refs_list(transport, for_push);
 898         }
 899
 900         if (data->push && for_push)
 901                 write_str_in_full(helper->in, "list for-push\n");
 902         else
 903                 write_str_in_full(helper->in, "list\n");
 904
 905         while (1) {
 906                 char *eov, *eon;
 907                 recvline(data, &buf);
 908
 909                 if (!*buf.buf)
 910                         break;
 911
 912                 eov = strchr(buf.buf, ' ');
 913                 if (!eov)
 914                         die("Malformed response in ref list: %s", buf.buf);
 915                 eon = strchr(eov + 1, ' ');
 916                 *eov = '\0';
 917                 if (eon)
 918                         *eon = '\0';
 919                 *tail = alloc_ref(eov + 1);
 920                 if (buf.buf[0] == '@')
 921                         (*tail)->symref = xstrdup(buf.buf + 1);
 922                 else if (buf.buf[0] != '?')
 923                         get_sha1_hex(buf.buf, (*tail)->old_sha1);
 924                 if (eon) {
 925                         if (has_attribute(eon + 1, "unchanged")) {
 926                                 (*tail)->status |= REF_STATUS_UPTODATE;
 927                                 read_ref((*tail)->name, (*tail)->old_sha1);
 928                         }
 929                 }
 930                 tail = &((*tail)->next);
 931         }
 932         if (debug)
 933                 fprintf(stderr, "Debug: Read ref listing.\n");
 934         strbuf_release(&buf);
 935
 936         for (posn = ret; posn; posn = posn->next)
 937                 resolve_remote_symref(posn, ret);
 938
 939         return ret;
 940 }
 941
 942 int transport_helper_init(struct transport *transport, const char *name)
 943 {
 944         struct helper_data *data = xcalloc(sizeof(*data), 1);
 945         data->name = name;
 946
 947         if (getenv("GIT_TRANSPORT_HELPER_DEBUG"))
 948                 debug = 1;
 949
 950         transport->data = data;
 951         transport->set_option = set_helper_option;
 952         transport->get_refs_list = get_refs_list;
 953         transport->fetch = fetch;
 954         transport->push_refs = push_refs;
 955         transport->disconnect = release_helper;
 956         transport->connect = connect_helper;
 957         transport->smart_options = &(data->transport_options);
 958         return 0;
 959 }
 960
 961 /*
 962  * Linux pipes can buffer 65536 bytes at once (and most platforms can
 963  * buffer less), so attempt reads and writes with up to that size.
 964  */
 965 #define BUFFERSIZE 65536
 966 /* This should be enough to hold debugging message. */
 967 #define PBUFFERSIZE 8192
 968
 969 /* Print bidirectional transfer loop debug message. */
 970 static void transfer_debug(const char *fmt, ...)
 971 {
 972         va_list args;
 973         char msgbuf[PBUFFERSIZE];
 974         static int debug_enabled = -1;
 975
 976         if (debug_enabled < 0)
 977                 debug_enabled = getenv("GIT_TRANSLOOP_DEBUG") ? 1 : 0;
 978         if (!debug_enabled)
 979                 return;
 980
 981         va_start(args, fmt);
 982         vsnprintf(msgbuf, PBUFFERSIZE, fmt, args);
 983         va_end(args);
 984         fprintf(stderr, "Transfer loop debugging: %s\n", msgbuf);
 985 }
 986
 987 /* Stream state: More data may be coming in this direction. */
 988 #define SSTATE_TRANSFERING 0
 989 /*
 990  * Stream state: No more data coming in this direction, flushing rest of
 991  * data.
 992  */
 993 #define SSTATE_FLUSHING 1
 994 /* Stream state: Transfer in this direction finished. */
 995 #define SSTATE_FINISHED 2
 996
 997 #define STATE_NEEDS_READING(state) ((state) <= SSTATE_TRANSFERING)
 998 #define STATE_NEEDS_WRITING(state) ((state) <= SSTATE_FLUSHING)
 999 #define STATE_NEEDS_CLOSING(state) ((state) == SSTATE_FLUSHING)
1000
1001 /* Unidirectional transfer. */
1002 struct unidirectional_transfer {
1003         /* Source */
1004         int src;
1005         /* Destination */
1006         int dest;
1007         /* Is source socket? */
1008         int src_is_sock;
1009         /* Is destination socket? */
1010         int dest_is_sock;
1011         /* Transfer state (TRANSFERING/FLUSHING/FINISHED) */
1012         int state;
1013         /* Buffer. */
1014         char buf[BUFFERSIZE];
1015         /* Buffer used. */
1016         size_t bufuse;
1017         /* Name of source. */
1018         const char *src_name;
1019         /* Name of destination. */
1020         const char *dest_name;
1021 };
1022
1023 /* Closes the target (for writing) if transfer has finished. */
1024 static void udt_close_if_finished(struct unidirectional_transfer *t)
1025 {
1026         if (STATE_NEEDS_CLOSING(t->state) && !t->bufuse) {
1027                 t->state = SSTATE_FINISHED;
1028                 if (t->dest_is_sock)
1029                         shutdown(t->dest, SHUT_WR);
1030                 else
1031                         close(t->dest);
1032                 transfer_debug("Closed %s.", t->dest_name);
1033         }
1034 }
1035
1036 /*
1037  * Tries to read read data from source into buffer. If buffer is full,
1038  * no data is read. Returns 0 on success, -1 on error.
1039  */
1040 static int udt_do_read(struct unidirectional_transfer *t)
1041 {
1042         ssize_t bytes;
1043
1044         if (t->bufuse == BUFFERSIZE)
1045                 return 0;       /* No space for more. */
1046
1047         transfer_debug("%s is readable", t->src_name);
1048         bytes = read(t->src, t->buf + t->bufuse, BUFFERSIZE - t->bufuse);
1049         if (bytes < 0 && errno != EWOULDBLOCK && errno != EAGAIN &&
1050                 errno != EINTR) {
1051                 error("read(%s) failed: %s", t->src_name, strerror(errno));
1052                 return -1;
1053         } else if (bytes == 0) {
1054                 transfer_debug("%s EOF (with %i bytes in buffer)",
1055                         t->src_name, t->bufuse);
1056                 t->state = SSTATE_FLUSHING;
1057         } else if (bytes > 0) {
1058                 t->bufuse += bytes;
1059                 transfer_debug("Read %i bytes from %s (buffer now at %i)",
1060                         (int)bytes, t->src_name, (int)t->bufuse);
1061         }
1062         return 0;
1063 }
1064
1065 /* Tries to write data from buffer into destination. If buffer is empty,
1066  * no data is written. Returns 0 on success, -1 on error.
1067  */
1068 static int udt_do_write(struct unidirectional_transfer *t)
1069 {
1070         ssize_t bytes;
1071
1072         if (t->bufuse == 0)
1073                 return 0;       /* Nothing to write. */
1074
1075         transfer_debug("%s is writable", t->dest_name);
1076         bytes = write(t->dest, t->buf, t->bufuse);
1077         if (bytes < 0 && errno != EWOULDBLOCK && errno != EAGAIN &&
1078                 errno != EINTR) {
1079                 error("write(%s) failed: %s", t->dest_name, strerror(errno));
1080                 return -1;
1081         } else if (bytes > 0) {
1082                 t->bufuse -= bytes;
1083                 if (t->bufuse)
1084                         memmove(t->buf, t->buf + bytes, t->bufuse);
1085                 transfer_debug("Wrote %i bytes to %s (buffer now at %i)",
1086                         (int)bytes, t->dest_name, (int)t->bufuse);
1087         }
1088         return 0;
1089 }
1090
1091
1092 /* State of bidirectional transfer loop. */
1093 struct bidirectional_transfer_state {
1094         /* Direction from program to git. */
1095         struct unidirectional_transfer ptg;
1096         /* Direction from git to program. */
1097         struct unidirectional_transfer gtp;
1098 };
1099
1100 static void *udt_copy_task_routine(void *udt)
1101 {
1102         struct unidirectional_transfer *t = (struct unidirectional_transfer *)udt;
1103         while (t->state != SSTATE_FINISHED) {
1104                 if (STATE_NEEDS_READING(t->state))
1105                         if (udt_do_read(t))
1106                                 return NULL;
1107                 if (STATE_NEEDS_WRITING(t->state))
1108                         if (udt_do_write(t))
1109                                 return NULL;
1110                 if (STATE_NEEDS_CLOSING(t->state))
1111                         udt_close_if_finished(t);
1112         }
1113         return udt;     /* Just some non-NULL value. */
1114 }
1115
1116 #ifndef NO_PTHREADS
1117
1118 /*
1119  * Join thread, with apporiate errors on failure. Name is name for the
1120  * thread (for error messages). Returns 0 on success, 1 on failure.
1121  */
1122 static int tloop_join(pthread_t thread, const char *name)
1123 {
1124         int err;
1125         void *tret;
1126         err = pthread_join(thread, &tret);
1127         if (!tret) {
1128                 error("%s thread failed", name);
1129                 return 1;
1130         }
1131         if (err) {
1132                 error("%s thread failed to join: %s", name, strerror(err));
1133                 return 1;
1134         }
1135         return 0;
1136 }
1137
1138 /*
1139  * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1140  * -1 on failure.
1141  */
1142 static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1143 {
1144         pthread_t gtp_thread;
1145         pthread_t ptg_thread;
1146         int err;
1147         int ret = 0;
1148         err = pthread_create(&gtp_thread, NULL, udt_copy_task_routine,
1149                 &s->gtp);
1150         if (err)
1151                 die("Can't start thread for copying data: %s", strerror(err));
1152         err = pthread_create(&ptg_thread, NULL, udt_copy_task_routine,
1153                 &s->ptg);
1154         if (err)
1155                 die("Can't start thread for copying data: %s", strerror(err));
1156
1157         ret |= tloop_join(gtp_thread, "Git to program copy");
1158         ret |= tloop_join(ptg_thread, "Program to git copy");
1159         return ret;
1160 }
1161 #else
1162
1163 /* Close the source and target (for writing) for transfer. */
1164 static void udt_kill_transfer(struct unidirectional_transfer *t)
1165 {
1166         t->state = SSTATE_FINISHED;
1167         /*
1168          * Socket read end left open isn't a disaster if nobody
1169          * attempts to read from it (mingw compat headers do not
1170          * have SHUT_RD)...
1171          *
1172          * We can't fully close the socket since otherwise gtp
1173          * task would first close the socket it sends data to
1174          * while closing the ptg file descriptors.
1175          */
1176         if (!t->src_is_sock)
1177                 close(t->src);
1178         if (t->dest_is_sock)
1179                 shutdown(t->dest, SHUT_WR);
1180         else
1181                 close(t->dest);
1182 }
1183
1184 /*
1185  * Join process, with apporiate errors on failure. Name is name for the
1186  * process (for error messages). Returns 0 on success, 1 on failure.
1187  */
1188 static int tloop_join(pid_t pid, const char *name)
1189 {
1190         int tret;
1191         if (waitpid(pid, &tret, 0) < 0) {
1192                 error("%s process failed to wait: %s", name, strerror(errno));
1193                 return 1;
1194         }
1195         if (!WIFEXITED(tret) || WEXITSTATUS(tret)) {
1196                 error("%s process failed", name);
1197                 return 1;
1198         }
1199         return 0;
1200 }
1201
1202 /*
1203  * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1204  * -1 on failure.
1205  */
1206 static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1207 {
1208         pid_t pid1, pid2;
1209         int ret = 0;
1210
1211         /* Fork thread #1: git to program. */
1212         pid1 = fork();
1213         if (pid1 < 0)
1214                 die_errno("Can't start thread for copying data");
1215         else if (pid1 == 0) {
1216                 udt_kill_transfer(&s->ptg);
1217                 exit(udt_copy_task_routine(&s->gtp) ? 0 : 1);
1218         }
1219
1220         /* Fork thread #2: program to git. */
1221         pid2 = fork();
1222         if (pid2 < 0)
1223                 die_errno("Can't start thread for copying data");
1224         else if (pid2 == 0) {
1225                 udt_kill_transfer(&s->gtp);
1226                 exit(udt_copy_task_routine(&s->ptg) ? 0 : 1);
1227         }
1228
1229         /*
1230          * Close both streams in parent as to not interfere with
1231          * end of file detection and wait for both tasks to finish.
1232          */
1233         udt_kill_transfer(&s->gtp);
1234         udt_kill_transfer(&s->ptg);
1235         ret |= tloop_join(pid1, "Git to program copy");
1236         ret |= tloop_join(pid2, "Program to git copy");
1237         return ret;
1238 }
1239 #endif
1240
1241 /*
1242  * Copies data from stdin to output and from input to stdout simultaneously.
1243  * Additionally filtering through given filter. If filter is NULL, uses
1244  * identity filter.
1245  */
1246 int bidirectional_transfer_loop(int input, int output)
1247 {
1248         struct bidirectional_transfer_state state;
1249
1250         /* Fill the state fields. */
1251         state.ptg.src = input;
1252         state.ptg.dest = 1;
1253         state.ptg.src_is_sock = (input == output);
1254         state.ptg.dest_is_sock = 0;
1255         state.ptg.state = SSTATE_TRANSFERING;
1256         state.ptg.bufuse = 0;
1257         state.ptg.src_name = "remote input";
1258         state.ptg.dest_name = "stdout";
1259
1260         state.gtp.src = 0;
1261         state.gtp.dest = output;
1262         state.gtp.src_is_sock = 0;
1263         state.gtp.dest_is_sock = (input == output);
1264         state.gtp.state = SSTATE_TRANSFERING;
1265         state.gtp.bufuse = 0;
1266         state.gtp.src_name = "stdin";
1267         state.gtp.dest_name = "remote output";
1268
1269         return tloop_spawnwait_tasks(&state);
1270 }