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
  13 static int debug;
  14
  15 struct helper_data {
  16         const char *name;
  17         struct child_process *helper;
  18         FILE *out;
  19         unsigned fetch : 1,
  20                 import : 1,
  21                 export : 1,
  22                 option : 1,
  23                 push : 1,
  24                 connect : 1,
  25                 no_disconnect_req : 1;
  26         char *export_marks;
  27         char *import_marks;
  28         /* These go from remote name (as in "list") to private name */
  29         struct refspec *refspecs;
  30         int refspec_nr;
  31         /* Transport options for fetch-pack/send-pack (should one of
  32          * those be invoked).
  33          */
  34         struct git_transport_options transport_options;
  35 };
  36
  37 static void sendline(struct helper_data *helper, struct strbuf *buffer)
  38 {
  39         if (debug)
  40                 fprintf(stderr, "Debug: Remote helper: -> %s", buffer->buf);
  41         if (write_in_full(helper->helper->in, buffer->buf, buffer->len)
  42                 != buffer->len)
  43                 die_errno("Full write to remote helper failed");
  44 }
  45
  46 static int recvline_fh(FILE *helper, struct strbuf *buffer)
  47 {
  48         strbuf_reset(buffer);
  49         if (debug)
  50                 fprintf(stderr, "Debug: Remote helper: Waiting...\n");
  51         if (strbuf_getline(buffer, helper, '\n') == EOF) {
  52                 if (debug)
  53                         fprintf(stderr, "Debug: Remote helper quit.\n");
  54                 exit(128);
  55         }
  56
  57         if (debug)
  58                 fprintf(stderr, "Debug: Remote helper: <- %s\n", buffer->buf);
  59         return 0;
  60 }
  61
  62 static int recvline(struct helper_data *helper, struct strbuf *buffer)
  63 {
  64         return recvline_fh(helper->out, buffer);
  65 }
  66
  67 static void xchgline(struct helper_data *helper, struct strbuf *buffer)
  68 {
  69         sendline(helper, buffer);
  70         recvline(helper, buffer);
  71 }
  72
  73 static void write_constant(int fd, const char *str)
  74 {
  75         if (debug)
  76                 fprintf(stderr, "Debug: Remote helper: -> %s", str);
  77         if (write_in_full(fd, str, strlen(str)) != strlen(str))
  78                 die_errno("Full write to remote helper failed");
  79 }
  80
  81 static const char *remove_ext_force(const char *url)
  82 {
  83         if (url) {
  84                 const char *colon = strchr(url, ':');
  85                 if (colon && colon[1] == ':')
  86                         return colon + 2;
  87         }
  88         return url;
  89 }
  90
  91 static void do_take_over(struct transport *transport)
  92 {
  93         struct helper_data *data;
  94         data = (struct helper_data *)transport->data;
  95         transport_take_over(transport, data->helper);
  96         fclose(data->out);
  97         free(data);
  98 }
  99
 100 static struct child_process *get_helper(struct transport *transport)
 101 {
 102         struct helper_data *data = transport->data;
 103         struct strbuf buf = STRBUF_INIT;
 104         struct child_process *helper;
 105         const char **refspecs = NULL;
 106         int refspec_nr = 0;
 107         int refspec_alloc = 0;
 108         int duped;
 109         int code;
 110         char git_dir_buf[sizeof(GIT_DIR_ENVIRONMENT) + PATH_MAX + 1];
 111         const char *helper_env[] = {
 112                 git_dir_buf,
 113                 NULL
 114         };
 115
 116
 117         if (data->helper)
 118                 return data->helper;
 119
 120         helper = xcalloc(1, sizeof(*helper));
 121         helper->in = -1;
 122         helper->out = -1;
 123         helper->err = 0;
 124         helper->argv = xcalloc(4, sizeof(*helper->argv));
 125         strbuf_addf(&buf, "git-remote-%s", data->name);
 126         helper->argv[0] = strbuf_detach(&buf, NULL);
 127         helper->argv[1] = transport->remote->name;
 128         helper->argv[2] = remove_ext_force(transport->url);
 129         helper->git_cmd = 0;
 130         helper->silent_exec_failure = 1;
 131
 132         snprintf(git_dir_buf, sizeof(git_dir_buf), "%s=%s", GIT_DIR_ENVIRONMENT, get_git_dir());
 133         helper->env = helper_env;
 134
 135         code = start_command(helper);
 136         if (code < 0 && errno == ENOENT)
 137                 die("Unable to find remote helper for '%s'", data->name);
 138         else if (code != 0)
 139                 exit(code);
 140
 141         data->helper = helper;
 142         data->no_disconnect_req = 0;
 143
 144         /*
 145          * Open the output as FILE* so strbuf_getline() can be used.
 146          * Do this with duped fd because fclose() will close the fd,
 147          * and stuff like taking over will require the fd to remain.
 148          */
 149         duped = dup(helper->out);
 150         if (duped < 0)
 151                 die_errno("Can't dup helper output fd");
 152         data->out = xfdopen(duped, "r");
 153
 154         write_constant(helper->in, "capabilities\n");
 155
 156         while (1) {
 157                 const char *capname;
 158                 int mandatory = 0;
 159                 recvline(data, &buf);
 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, "export"))
 181                         data->export = 1;
 182                 else if (!data->refspecs && !prefixcmp(capname, "refspec ")) {
 183                         ALLOC_GROW(refspecs,
 184                                    refspec_nr + 1,
 185                                    refspec_alloc);
 186                         refspecs[refspec_nr++] = strdup(capname + strlen("refspec "));
 187                 } else if (!strcmp(capname, "connect")) {
 188                         data->connect = 1;
 189                 } else if (!prefixcmp(capname, "export-marks ")) {
 190                         struct strbuf arg = STRBUF_INIT;
 191                         strbuf_addstr(&arg, "--export-marks=");
 192                         strbuf_addstr(&arg, capname + strlen("export-marks "));
 193                         data->export_marks = strbuf_detach(&arg, NULL);
 194                 } else if (!prefixcmp(capname, "import-marks")) {
 195                         struct strbuf arg = STRBUF_INIT;
 196                         strbuf_addstr(&arg, "--import-marks=");
 197                         strbuf_addstr(&arg, capname + strlen("import-marks "));
 198                         data->import_marks = strbuf_detach(&arg, NULL);
 199                 } else if (mandatory) {
 200                         die("Unknown mandatory capability %s. This remote "
 201                             "helper probably needs newer version of Git.\n",
 202                             capname);
 203                 }
 204         }
 205         if (refspecs) {
 206                 int i;
 207                 data->refspec_nr = refspec_nr;
 208                 data->refspecs = parse_fetch_refspec(refspec_nr, refspecs);
 209                 for (i = 0; i < refspec_nr; i++) {
 210                         free((char *)refspecs[i]);
 211                 }
 212                 free(refspecs);
 213         }
 214         strbuf_release(&buf);
 215         if (debug)
 216                 fprintf(stderr, "Debug: Capabilities complete.\n");
 217         return data->helper;
 218 }
 219
 220 static int disconnect_helper(struct transport *transport)
 221 {
 222         struct helper_data *data = transport->data;
 223         struct strbuf buf = STRBUF_INIT;
 224         int res = 0;
 225
 226         if (data->helper) {
 227                 if (debug)
 228                         fprintf(stderr, "Debug: Disconnecting.\n");
 229                 if (!data->no_disconnect_req) {
 230                         strbuf_addf(&buf, "\n");
 231                         sendline(data, &buf);
 232                 }
 233                 close(data->helper->in);
 234                 close(data->helper->out);
 235                 fclose(data->out);
 236                 res = finish_command(data->helper);
 237                 free((char *)data->helper->argv[0]);
 238                 free(data->helper->argv);
 239                 free(data->helper);
 240                 data->helper = NULL;
 241         }
 242         return res;
 243 }
 244
 245 static const char *unsupported_options[] = {
 246         TRANS_OPT_UPLOADPACK,
 247         TRANS_OPT_RECEIVEPACK,
 248         TRANS_OPT_THIN,
 249         TRANS_OPT_KEEP
 250         };
 251 static const char *boolean_options[] = {
 252         TRANS_OPT_THIN,
 253         TRANS_OPT_KEEP,
 254         TRANS_OPT_FOLLOWTAGS
 255         };
 256
 257 static int set_helper_option(struct transport *transport,
 258                           const char *name, const char *value)
 259 {
 260         struct helper_data *data = transport->data;
 261         struct strbuf buf = STRBUF_INIT;
 262         int i, ret, is_bool = 0;
 263
 264         get_helper(transport);
 265
 266         if (!data->option)
 267                 return 1;
 268
 269         for (i = 0; i < ARRAY_SIZE(unsupported_options); i++) {
 270                 if (!strcmp(name, unsupported_options[i]))
 271                         return 1;
 272         }
 273
 274         for (i = 0; i < ARRAY_SIZE(boolean_options); i++) {
 275                 if (!strcmp(name, boolean_options[i])) {
 276                         is_bool = 1;
 277                         break;
 278                 }
 279         }
 280
 281         strbuf_addf(&buf, "option %s ", name);
 282         if (is_bool)
 283                 strbuf_addstr(&buf, value ? "true" : "false");
 284         else
 285                 quote_c_style(value, &buf, NULL, 0);
 286         strbuf_addch(&buf, '\n');
 287
 288         xchgline(data, &buf);
 289
 290         if (!strcmp(buf.buf, "ok"))
 291                 ret = 0;
 292         else if (!prefixcmp(buf.buf, "error")) {
 293                 ret = -1;
 294         } else if (!strcmp(buf.buf, "unsupported"))
 295                 ret = 1;
 296         else {
 297                 warning("%s unexpectedly said: '%s'", data->name, buf.buf);
 298                 ret = 1;
 299         }
 300         strbuf_release(&buf);
 301         return ret;
 302 }
 303
 304 static void standard_options(struct transport *t)
 305 {
 306         char buf[16];
 307         int n;
 308         int v = t->verbose;
 309
 310         set_helper_option(t, "progress", t->progress ? "true" : "false");
 311
 312         n = snprintf(buf, sizeof(buf), "%d", v + 1);
 313         if (n >= sizeof(buf))
 314                 die("impossibly large verbosity value");
 315         set_helper_option(t, "verbosity", buf);
 316 }
 317
 318 static int release_helper(struct transport *transport)
 319 {
 320         int res = 0;
 321         struct helper_data *data = transport->data;
 322         free_refspec(data->refspec_nr, data->refspecs);
 323         data->refspecs = NULL;
 324         res = disconnect_helper(transport);
 325         free(transport->data);
 326         return res;
 327 }
 328
 329 static int fetch_with_fetch(struct transport *transport,
 330                             int nr_heads, struct ref **to_fetch)
 331 {
 332         struct helper_data *data = transport->data;
 333         int i;
 334         struct strbuf buf = STRBUF_INIT;
 335
 336         standard_options(transport);
 337
 338         for (i = 0; i < nr_heads; i++) {
 339                 const struct ref *posn = to_fetch[i];
 340                 if (posn->status & REF_STATUS_UPTODATE)
 341                         continue;
 342
 343                 strbuf_addf(&buf, "fetch %s %s\n",
 344                             sha1_to_hex(posn->old_sha1), posn->name);
 345         }
 346
 347         strbuf_addch(&buf, '\n');
 348         sendline(data, &buf);
 349
 350         while (1) {
 351                 recvline(data, &buf);
 352
 353                 if (!prefixcmp(buf.buf, "lock ")) {
 354                         const char *name = buf.buf + 5;
 355                         if (transport->pack_lockfile)
 356                                 warning("%s also locked %s", data->name, name);
 357                         else
 358                                 transport->pack_lockfile = xstrdup(name);
 359                 }
 360                 else if (!buf.len)
 361                         break;
 362                 else
 363                         warning("%s unexpectedly said: '%s'", data->name, buf.buf);
 364         }
 365         strbuf_release(&buf);
 366         return 0;
 367 }
 368
 369 static int get_importer(struct transport *transport, struct child_process *fastimport)
 370 {
 371         struct child_process *helper = get_helper(transport);
 372         memset(fastimport, 0, sizeof(*fastimport));
 373         fastimport->in = helper->out;
 374         fastimport->argv = xcalloc(5, sizeof(*fastimport->argv));
 375         fastimport->argv[0] = "fast-import";
 376         fastimport->argv[1] = "--quiet";
 377
 378         fastimport->git_cmd = 1;
 379         return start_command(fastimport);
 380 }
 381
 382 static int get_exporter(struct transport *transport,
 383                         struct child_process *fastexport,
 384                         struct string_list *revlist_args)
 385 {
 386         struct helper_data *data = transport->data;
 387         struct child_process *helper = get_helper(transport);
 388         int argc = 0, i;
 389         memset(fastexport, 0, sizeof(*fastexport));
 390
 391         /* we need to duplicate helper->in because we want to use it after
 392          * fastexport is done with it. */
 393         fastexport->out = dup(helper->in);
 394         fastexport->argv = xcalloc(6 + revlist_args->nr, sizeof(*fastexport->argv));
 395         fastexport->argv[argc++] = "fast-export";
 396         fastexport->argv[argc++] = "--use-done-feature";
 397         if (data->export_marks)
 398                 fastexport->argv[argc++] = data->export_marks;
 399         if (data->import_marks)
 400                 fastexport->argv[argc++] = data->import_marks;
 401
 402         for (i = 0; i < revlist_args->nr; i++)
 403                 fastexport->argv[argc++] = revlist_args->items[i].string;
 404
 405         fastexport->argv[argc++] = "--";
 406
 407         fastexport->git_cmd = 1;
 408         return start_command(fastexport);
 409 }
 410
 411 static void check_helper_status(struct helper_data *data)
 412 {
 413         int pid, status;
 414
 415         pid = waitpid(data->helper->pid, &status, WNOHANG);
 416         if (pid < 0)
 417                 die("Could not retrieve status of remote helper '%s'",
 418                     data->name);
 419         if (pid > 0 && WIFEXITED(status))
 420                 die("Remote helper '%s' died with %d",
 421                     data->name, WEXITSTATUS(status));
 422 }
 423
 424 static int fetch_with_import(struct transport *transport,
 425                              int nr_heads, struct ref **to_fetch)
 426 {
 427         struct child_process fastimport;
 428         struct helper_data *data = transport->data;
 429         int i;
 430         struct ref *posn;
 431         struct strbuf buf = STRBUF_INIT;
 432
 433         get_helper(transport);
 434
 435         if (get_importer(transport, &fastimport))
 436                 die("Couldn't run fast-import");
 437
 438         for (i = 0; i < nr_heads; i++) {
 439                 posn = to_fetch[i];
 440                 if (posn->status & REF_STATUS_UPTODATE)
 441                         continue;
 442
 443                 strbuf_addf(&buf, "import %s\n", posn->name);
 444                 sendline(data, &buf);
 445                 strbuf_reset(&buf);
 446         }
 447
 448         write_constant(data->helper->in, "\n");
 449
 450         if (finish_command(&fastimport))
 451                 die("Error while running fast-import");
 452         check_helper_status(data);
 453
 454         free(fastimport.argv);
 455         fastimport.argv = NULL;
 456
 457         for (i = 0; i < nr_heads; i++) {
 458                 char *private;
 459                 posn = to_fetch[i];
 460                 if (posn->status & REF_STATUS_UPTODATE)
 461                         continue;
 462                 if (data->refspecs)
 463                         private = apply_refspecs(data->refspecs, data->refspec_nr, posn->name);
 464                 else
 465                         private = strdup(posn->name);
 466                 read_ref(private, posn->old_sha1);
 467                 free(private);
 468         }
 469         strbuf_release(&buf);
 470         return 0;
 471 }
 472
 473 static int process_connect_service(struct transport *transport,
 474                                    const char *name, const char *exec)
 475 {
 476         struct helper_data *data = transport->data;
 477         struct strbuf cmdbuf = STRBUF_INIT;
 478         struct child_process *helper;
 479         int r, duped, ret = 0;
 480         FILE *input;
 481
 482         helper = get_helper(transport);
 483
 484         /*
 485          * Yes, dup the pipe another time, as we need unbuffered version
 486          * of input pipe as FILE*. fclose() closes the underlying fd and
 487          * stream buffering only can be changed before first I/O operation
 488          * on it.
 489          */
 490         duped = dup(helper->out);
 491         if (duped < 0)
 492                 die_errno("Can't dup helper output fd");
 493         input = xfdopen(duped, "r");
 494         setvbuf(input, NULL, _IONBF, 0);
 495
 496         /*
 497          * Handle --upload-pack and friends. This is fire and forget...
 498          * just warn if it fails.
 499          */
 500         if (strcmp(name, exec)) {
 501                 r = set_helper_option(transport, "servpath", exec);
 502                 if (r > 0)
 503                         warning("Setting remote service path not supported by protocol.");
 504                 else if (r < 0)
 505                         warning("Invalid remote service path.");
 506         }
 507
 508         if (data->connect)
 509                 strbuf_addf(&cmdbuf, "connect %s\n", name);
 510         else
 511                 goto exit;
 512
 513         sendline(data, &cmdbuf);
 514         recvline_fh(input, &cmdbuf);
 515         if (!strcmp(cmdbuf.buf, "")) {
 516                 data->no_disconnect_req = 1;
 517                 if (debug)
 518                         fprintf(stderr, "Debug: Smart transport connection "
 519                                 "ready.\n");
 520                 ret = 1;
 521         } else if (!strcmp(cmdbuf.buf, "fallback")) {
 522                 if (debug)
 523                         fprintf(stderr, "Debug: Falling back to dumb "
 524                                 "transport.\n");
 525         } else
 526                 die("Unknown response to connect: %s",
 527                         cmdbuf.buf);
 528
 529 exit:
 530         fclose(input);
 531         return ret;
 532 }
 533
 534 static int process_connect(struct transport *transport,
 535                                      int for_push)
 536 {
 537         struct helper_data *data = transport->data;
 538         const char *name;
 539         const char *exec;
 540
 541         name = for_push ? "git-receive-pack" : "git-upload-pack";
 542         if (for_push)
 543                 exec = data->transport_options.receivepack;
 544         else
 545                 exec = data->transport_options.uploadpack;
 546
 547         return process_connect_service(transport, name, exec);
 548 }
 549
 550 static int connect_helper(struct transport *transport, const char *name,
 551                    const char *exec, int fd[2])
 552 {
 553         struct helper_data *data = transport->data;
 554
 555         /* Get_helper so connect is inited. */
 556         get_helper(transport);
 557         if (!data->connect)
 558                 die("Operation not supported by protocol.");
 559
 560         if (!process_connect_service(transport, name, exec))
 561                 die("Can't connect to subservice %s.", name);
 562
 563         fd[0] = data->helper->out;
 564         fd[1] = data->helper->in;
 565         return 0;
 566 }
 567
 568 static int fetch(struct transport *transport,
 569                  int nr_heads, struct ref **to_fetch)
 570 {
 571         struct helper_data *data = transport->data;
 572         int i, count;
 573
 574         if (process_connect(transport, 0)) {
 575                 do_take_over(transport);
 576                 return transport->fetch(transport, nr_heads, to_fetch);
 577         }
 578
 579         count = 0;
 580         for (i = 0; i < nr_heads; i++)
 581                 if (!(to_fetch[i]->status & REF_STATUS_UPTODATE))
 582                         count++;
 583
 584         if (!count)
 585                 return 0;
 586
 587         if (data->fetch)
 588                 return fetch_with_fetch(transport, nr_heads, to_fetch);
 589
 590         if (data->import)
 591                 return fetch_with_import(transport, nr_heads, to_fetch);
 592
 593         return -1;
 594 }
 595
 596 static void push_update_ref_status(struct strbuf *buf,
 597                                    struct ref **ref,
 598                                    struct ref *remote_refs)
 599 {
 600         char *refname, *msg;
 601         int status;
 602
 603         if (!prefixcmp(buf->buf, "ok ")) {
 604                 status = REF_STATUS_OK;
 605                 refname = buf->buf + 3;
 606         } else if (!prefixcmp(buf->buf, "error ")) {
 607                 status = REF_STATUS_REMOTE_REJECT;
 608                 refname = buf->buf + 6;
 609         } else
 610                 die("expected ok/error, helper said '%s'\n", buf->buf);
 611
 612         msg = strchr(refname, ' ');
 613         if (msg) {
 614                 struct strbuf msg_buf = STRBUF_INIT;
 615                 const char *end;
 616
 617                 *msg++ = '\0';
 618                 if (!unquote_c_style(&msg_buf, msg, &end))
 619                         msg = strbuf_detach(&msg_buf, NULL);
 620                 else
 621                         msg = xstrdup(msg);
 622                 strbuf_release(&msg_buf);
 623
 624                 if (!strcmp(msg, "no match")) {
 625                         status = REF_STATUS_NONE;
 626                         free(msg);
 627                         msg = NULL;
 628                 }
 629                 else if (!strcmp(msg, "up to date")) {
 630                         status = REF_STATUS_UPTODATE;
 631                         free(msg);
 632                         msg = NULL;
 633                 }
 634                 else if (!strcmp(msg, "non-fast forward")) {
 635                         status = REF_STATUS_REJECT_NONFASTFORWARD;
 636                         free(msg);
 637                         msg = NULL;
 638                 }
 639         }
 640
 641         if (*ref)
 642                 *ref = find_ref_by_name(*ref, refname);
 643         if (!*ref)
 644                 *ref = find_ref_by_name(remote_refs, refname);
 645         if (!*ref) {
 646                 warning("helper reported unexpected status of %s", refname);
 647                 return;
 648         }
 649
 650         if ((*ref)->status != REF_STATUS_NONE) {
 651                 /*
 652                  * Earlier, the ref was marked not to be pushed, so ignore the ref
 653                  * status reported by the remote helper if the latter is 'no match'.
 654                  */
 655                 if (status == REF_STATUS_NONE)
 656                         return;
 657         }
 658
 659         (*ref)->status = status;
 660         (*ref)->remote_status = msg;
 661 }
 662
 663 static void push_update_refs_status(struct helper_data *data,
 664                                     struct ref *remote_refs)
 665 {
 666         struct strbuf buf = STRBUF_INIT;
 667         struct ref *ref = remote_refs;
 668         for (;;) {
 669                 recvline(data, &buf);
 670                 if (!buf.len)
 671                         break;
 672
 673                 push_update_ref_status(&buf, &ref, remote_refs);
 674         }
 675         strbuf_release(&buf);
 676 }
 677
 678 static int push_refs_with_push(struct transport *transport,
 679                 struct ref *remote_refs, int flags)
 680 {
 681         int force_all = flags & TRANSPORT_PUSH_FORCE;
 682         int mirror = flags & TRANSPORT_PUSH_MIRROR;
 683         struct helper_data *data = transport->data;
 684         struct strbuf buf = STRBUF_INIT;
 685         struct ref *ref;
 686
 687         get_helper(transport);
 688         if (!data->push)
 689                 return 1;
 690
 691         for (ref = remote_refs; ref; ref = ref->next) {
 692                 if (!ref->peer_ref && !mirror)
 693                         continue;
 694
 695                 /* Check for statuses set by set_ref_status_for_push() */
 696                 switch (ref->status) {
 697                 case REF_STATUS_REJECT_NONFASTFORWARD:
 698                 case REF_STATUS_UPTODATE:
 699                         continue;
 700                 default:
 701                         ; /* do nothing */
 702                 }
 703
 704                 if (force_all)
 705                         ref->force = 1;
 706
 707                 strbuf_addstr(&buf, "push ");
 708                 if (!ref->deletion) {
 709                         if (ref->force)
 710                                 strbuf_addch(&buf, '+');
 711                         if (ref->peer_ref)
 712                                 strbuf_addstr(&buf, ref->peer_ref->name);
 713                         else
 714                                 strbuf_addstr(&buf, sha1_to_hex(ref->new_sha1));
 715                 }
 716                 strbuf_addch(&buf, ':');
 717                 strbuf_addstr(&buf, ref->name);
 718                 strbuf_addch(&buf, '\n');
 719         }
 720         if (buf.len == 0)
 721                 return 0;
 722
 723         standard_options(transport);
 724
 725         if (flags & TRANSPORT_PUSH_DRY_RUN) {
 726                 if (set_helper_option(transport, "dry-run", "true") != 0)
 727                         die("helper %s does not support dry-run", data->name);
 728         }
 729
 730         strbuf_addch(&buf, '\n');
 731         sendline(data, &buf);
 732         strbuf_release(&buf);
 733
 734         push_update_refs_status(data, remote_refs);
 735         return 0;
 736 }
 737
 738 static int push_refs_with_export(struct transport *transport,
 739                 struct ref *remote_refs, int flags)
 740 {
 741         struct ref *ref;
 742         struct child_process *helper, exporter;
 743         struct helper_data *data = transport->data;
 744         struct string_list revlist_args = STRING_LIST_INIT_NODUP;
 745         struct strbuf buf = STRBUF_INIT;
 746
 747         helper = get_helper(transport);
 748
 749         write_constant(helper->in, "export\n");
 750
 751         strbuf_reset(&buf);
 752
 753         for (ref = remote_refs; ref; ref = ref->next) {
 754                 char *private;
 755                 unsigned char sha1[20];
 756
 757                 if (!data->refspecs)
 758                         continue;
 759                 private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
 760                 if (private && !get_sha1(private, sha1)) {
 761                         strbuf_addf(&buf, "^%s", private);
 762                         string_list_append(&revlist_args, strbuf_detach(&buf, NULL));
 763                 }
 764                 free(private);
 765
 766                 if (ref->deletion) {
 767                         die("remote-helpers do not support ref deletion");
 768                 }
 769
 770                 if (ref->peer_ref)
 771                         string_list_append(&revlist_args, ref->peer_ref->name);
 772
 773         }
 774
 775         if (get_exporter(transport, &exporter, &revlist_args))
 776                 die("Couldn't run fast-export");
 777
 778         if (finish_command(&exporter))
 779                 die("Error while running fast-export");
 780         check_helper_status(data);
 781         push_update_refs_status(data, remote_refs);
 782         return 0;
 783 }
 784
 785 static int push_refs(struct transport *transport,
 786                 struct ref *remote_refs, int flags)
 787 {
 788         struct helper_data *data = transport->data;
 789
 790         if (process_connect(transport, 1)) {
 791                 do_take_over(transport);
 792                 return transport->push_refs(transport, remote_refs, flags);
 793         }
 794
 795         if (!remote_refs) {
 796                 fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
 797                         "Perhaps you should specify a branch such as 'master'.\n");
 798                 return 0;
 799         }
 800
 801         if (data->push)
 802                 return push_refs_with_push(transport, remote_refs, flags);
 803
 804         if (data->export)
 805                 return push_refs_with_export(transport, remote_refs, flags);
 806
 807         return -1;
 808 }
 809
 810
 811 static int has_attribute(const char *attrs, const char *attr) {
 812         int len;
 813         if (!attrs)
 814                 return 0;
 815
 816         len = strlen(attr);
 817         for (;;) {
 818                 const char *space = strchrnul(attrs, ' ');
 819                 if (len == space - attrs && !strncmp(attrs, attr, len))
 820                         return 1;
 821                 if (!*space)
 822                         return 0;
 823                 attrs = space + 1;
 824         }
 825 }
 826
 827 static struct ref *get_refs_list(struct transport *transport, int for_push)
 828 {
 829         struct helper_data *data = transport->data;
 830         struct child_process *helper;
 831         struct ref *ret = NULL;
 832         struct ref **tail = &ret;
 833         struct ref *posn;
 834         struct strbuf buf = STRBUF_INIT;
 835
 836         helper = get_helper(transport);
 837
 838         if (process_connect(transport, for_push)) {
 839                 do_take_over(transport);
 840                 return transport->get_refs_list(transport, for_push);
 841         }
 842
 843         if (data->push && for_push)
 844                 write_str_in_full(helper->in, "list for-push\n");
 845         else
 846                 write_str_in_full(helper->in, "list\n");
 847
 848         while (1) {
 849                 char *eov, *eon;
 850                 recvline(data, &buf);
 851
 852                 if (!*buf.buf)
 853                         break;
 854
 855                 eov = strchr(buf.buf, ' ');
 856                 if (!eov)
 857                         die("Malformed response in ref list: %s", buf.buf);
 858                 eon = strchr(eov + 1, ' ');
 859                 *eov = '\0';
 860                 if (eon)
 861                         *eon = '\0';
 862                 *tail = alloc_ref(eov + 1);
 863                 if (buf.buf[0] == '@')
 864                         (*tail)->symref = xstrdup(buf.buf + 1);
 865                 else if (buf.buf[0] != '?')
 866                         get_sha1_hex(buf.buf, (*tail)->old_sha1);
 867                 if (eon) {
 868                         if (has_attribute(eon + 1, "unchanged")) {
 869                                 (*tail)->status |= REF_STATUS_UPTODATE;
 870                                 read_ref((*tail)->name, (*tail)->old_sha1);
 871                         }
 872                 }
 873                 tail = &((*tail)->next);
 874         }
 875         if (debug)
 876                 fprintf(stderr, "Debug: Read ref listing.\n");
 877         strbuf_release(&buf);
 878
 879         for (posn = ret; posn; posn = posn->next)
 880                 resolve_remote_symref(posn, ret);
 881
 882         return ret;
 883 }
 884
 885 int transport_helper_init(struct transport *transport, const char *name)
 886 {
 887         struct helper_data *data = xcalloc(sizeof(*data), 1);
 888         data->name = name;
 889
 890         if (getenv("GIT_TRANSPORT_HELPER_DEBUG"))
 891                 debug = 1;
 892
 893         transport->data = data;
 894         transport->set_option = set_helper_option;
 895         transport->get_refs_list = get_refs_list;
 896         transport->fetch = fetch;
 897         transport->push_refs = push_refs;
 898         transport->disconnect = release_helper;
 899         transport->connect = connect_helper;
 900         transport->smart_options = &(data->transport_options);
 901         return 0;
 902 }
 903
 904 /*
 905  * Linux pipes can buffer 65536 bytes at once (and most platforms can
 906  * buffer less), so attempt reads and writes with up to that size.
 907  */
 908 #define BUFFERSIZE 65536
 909 /* This should be enough to hold debugging message. */
 910 #define PBUFFERSIZE 8192
 911
 912 /* Print bidirectional transfer loop debug message. */
 913 static void transfer_debug(const char *fmt, ...)
 914 {
 915         va_list args;
 916         char msgbuf[PBUFFERSIZE];
 917         static int debug_enabled = -1;
 918
 919         if (debug_enabled < 0)
 920                 debug_enabled = getenv("GIT_TRANSLOOP_DEBUG") ? 1 : 0;
 921         if (!debug_enabled)
 922                 return;
 923
 924         va_start(args, fmt);
 925         vsnprintf(msgbuf, PBUFFERSIZE, fmt, args);
 926         va_end(args);
 927         fprintf(stderr, "Transfer loop debugging: %s\n", msgbuf);
 928 }
 929
 930 /* Stream state: More data may be coming in this direction. */
 931 #define SSTATE_TRANSFERING 0
 932 /*
 933  * Stream state: No more data coming in this direction, flushing rest of
 934  * data.
 935  */
 936 #define SSTATE_FLUSHING 1
 937 /* Stream state: Transfer in this direction finished. */
 938 #define SSTATE_FINISHED 2
 939
 940 #define STATE_NEEDS_READING(state) ((state) <= SSTATE_TRANSFERING)
 941 #define STATE_NEEDS_WRITING(state) ((state) <= SSTATE_FLUSHING)
 942 #define STATE_NEEDS_CLOSING(state) ((state) == SSTATE_FLUSHING)
 943
 944 /* Unidirectional transfer. */
 945 struct unidirectional_transfer {
 946         /* Source */
 947         int src;
 948         /* Destination */
 949         int dest;
 950         /* Is source socket? */
 951         int src_is_sock;
 952         /* Is destination socket? */
 953         int dest_is_sock;
 954         /* Transfer state (TRANSFERING/FLUSHING/FINISHED) */
 955         int state;
 956         /* Buffer. */
 957         char buf[BUFFERSIZE];
 958         /* Buffer used. */
 959         size_t bufuse;
 960         /* Name of source. */
 961         const char *src_name;
 962         /* Name of destination. */
 963         const char *dest_name;
 964 };
 965
 966 /* Closes the target (for writing) if transfer has finished. */
 967 static void udt_close_if_finished(struct unidirectional_transfer *t)
 968 {
 969         if (STATE_NEEDS_CLOSING(t->state) && !t->bufuse) {
 970                 t->state = SSTATE_FINISHED;
 971                 if (t->dest_is_sock)
 972                         shutdown(t->dest, SHUT_WR);
 973                 else
 974                         close(t->dest);
 975                 transfer_debug("Closed %s.", t->dest_name);
 976         }
 977 }
 978
 979 /*
 980  * Tries to read read data from source into buffer. If buffer is full,
 981  * no data is read. Returns 0 on success, -1 on error.
 982  */
 983 static int udt_do_read(struct unidirectional_transfer *t)
 984 {
 985         ssize_t bytes;
 986
 987         if (t->bufuse == BUFFERSIZE)
 988                 return 0;       /* No space for more. */
 989
 990         transfer_debug("%s is readable", t->src_name);
 991         bytes = read(t->src, t->buf + t->bufuse, BUFFERSIZE - t->bufuse);
 992         if (bytes < 0 && errno != EWOULDBLOCK && errno != EAGAIN &&
 993                 errno != EINTR) {
 994                 error("read(%s) failed: %s", t->src_name, strerror(errno));
 995                 return -1;
 996         } else if (bytes == 0) {
 997                 transfer_debug("%s EOF (with %i bytes in buffer)",
 998                         t->src_name, t->bufuse);
 999                 t->state = SSTATE_FLUSHING;
1000         } else if (bytes > 0) {
1001                 t->bufuse += bytes;
1002                 transfer_debug("Read %i bytes from %s (buffer now at %i)",
1003                         (int)bytes, t->src_name, (int)t->bufuse);
1004         }
1005         return 0;
1006 }
1007
1008 /* Tries to write data from buffer into destination. If buffer is empty,
1009  * no data is written. Returns 0 on success, -1 on error.
1010  */
1011 static int udt_do_write(struct unidirectional_transfer *t)
1012 {
1013         ssize_t bytes;
1014
1015         if (t->bufuse == 0)
1016                 return 0;       /* Nothing to write. */
1017
1018         transfer_debug("%s is writable", t->dest_name);
1019         bytes = write(t->dest, t->buf, t->bufuse);
1020         if (bytes < 0 && errno != EWOULDBLOCK && errno != EAGAIN &&
1021                 errno != EINTR) {
1022                 error("write(%s) failed: %s", t->dest_name, strerror(errno));
1023                 return -1;
1024         } else if (bytes > 0) {
1025                 t->bufuse -= bytes;
1026                 if (t->bufuse)
1027                         memmove(t->buf, t->buf + bytes, t->bufuse);
1028                 transfer_debug("Wrote %i bytes to %s (buffer now at %i)",
1029                         (int)bytes, t->dest_name, (int)t->bufuse);
1030         }
1031         return 0;
1032 }
1033
1034
1035 /* State of bidirectional transfer loop. */
1036 struct bidirectional_transfer_state {
1037         /* Direction from program to git. */
1038         struct unidirectional_transfer ptg;
1039         /* Direction from git to program. */
1040         struct unidirectional_transfer gtp;
1041 };
1042
1043 static void *udt_copy_task_routine(void *udt)
1044 {
1045         struct unidirectional_transfer *t = (struct unidirectional_transfer *)udt;
1046         while (t->state != SSTATE_FINISHED) {
1047                 if (STATE_NEEDS_READING(t->state))
1048                         if (udt_do_read(t))
1049                                 return NULL;
1050                 if (STATE_NEEDS_WRITING(t->state))
1051                         if (udt_do_write(t))
1052                                 return NULL;
1053                 if (STATE_NEEDS_CLOSING(t->state))
1054                         udt_close_if_finished(t);
1055         }
1056         return udt;     /* Just some non-NULL value. */
1057 }
1058
1059 #ifndef NO_PTHREADS
1060
1061 /*
1062  * Join thread, with apporiate errors on failure. Name is name for the
1063  * thread (for error messages). Returns 0 on success, 1 on failure.
1064  */
1065 static int tloop_join(pthread_t thread, const char *name)
1066 {
1067         int err;
1068         void *tret;
1069         err = pthread_join(thread, &tret);
1070         if (!tret) {
1071                 error("%s thread failed", name);
1072                 return 1;
1073         }
1074         if (err) {
1075                 error("%s thread failed to join: %s", name, strerror(err));
1076                 return 1;
1077         }
1078         return 0;
1079 }
1080
1081 /*
1082  * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1083  * -1 on failure.
1084  */
1085 static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1086 {
1087         pthread_t gtp_thread;
1088         pthread_t ptg_thread;
1089         int err;
1090         int ret = 0;
1091         err = pthread_create(&gtp_thread, NULL, udt_copy_task_routine,
1092                 &s->gtp);
1093         if (err)
1094                 die("Can't start thread for copying data: %s", strerror(err));
1095         err = pthread_create(&ptg_thread, NULL, udt_copy_task_routine,
1096                 &s->ptg);
1097         if (err)
1098                 die("Can't start thread for copying data: %s", strerror(err));
1099
1100         ret |= tloop_join(gtp_thread, "Git to program copy");
1101         ret |= tloop_join(ptg_thread, "Program to git copy");
1102         return ret;
1103 }
1104 #else
1105
1106 /* Close the source and target (for writing) for transfer. */
1107 static void udt_kill_transfer(struct unidirectional_transfer *t)
1108 {
1109         t->state = SSTATE_FINISHED;
1110         /*
1111          * Socket read end left open isn't a disaster if nobody
1112          * attempts to read from it (mingw compat headers do not
1113          * have SHUT_RD)...
1114          *
1115          * We can't fully close the socket since otherwise gtp
1116          * task would first close the socket it sends data to
1117          * while closing the ptg file descriptors.
1118          */
1119         if (!t->src_is_sock)
1120                 close(t->src);
1121         if (t->dest_is_sock)
1122                 shutdown(t->dest, SHUT_WR);
1123         else
1124                 close(t->dest);
1125 }
1126
1127 /*
1128  * Join process, with apporiate errors on failure. Name is name for the
1129  * process (for error messages). Returns 0 on success, 1 on failure.
1130  */
1131 static int tloop_join(pid_t pid, const char *name)
1132 {
1133         int tret;
1134         if (waitpid(pid, &tret, 0) < 0) {
1135                 error("%s process failed to wait: %s", name, strerror(errno));
1136                 return 1;
1137         }
1138         if (!WIFEXITED(tret) || WEXITSTATUS(tret)) {
1139                 error("%s process failed", name);
1140                 return 1;
1141         }
1142         return 0;
1143 }
1144
1145 /*
1146  * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1147  * -1 on failure.
1148  */
1149 static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1150 {
1151         pid_t pid1, pid2;
1152         int ret = 0;
1153
1154         /* Fork thread #1: git to program. */
1155         pid1 = fork();
1156         if (pid1 < 0)
1157                 die_errno("Can't start thread for copying data");
1158         else if (pid1 == 0) {
1159                 udt_kill_transfer(&s->ptg);
1160                 exit(udt_copy_task_routine(&s->gtp) ? 0 : 1);
1161         }
1162
1163         /* Fork thread #2: program to git. */
1164         pid2 = fork();
1165         if (pid2 < 0)
1166                 die_errno("Can't start thread for copying data");
1167         else if (pid2 == 0) {
1168                 udt_kill_transfer(&s->gtp);
1169                 exit(udt_copy_task_routine(&s->ptg) ? 0 : 1);
1170         }
1171
1172         /*
1173          * Close both streams in parent as to not interfere with
1174          * end of file detection and wait for both tasks to finish.
1175          */
1176         udt_kill_transfer(&s->gtp);
1177         udt_kill_transfer(&s->ptg);
1178         ret |= tloop_join(pid1, "Git to program copy");
1179         ret |= tloop_join(pid2, "Program to git copy");
1180         return ret;
1181 }
1182 #endif
1183
1184 /*
1185  * Copies data from stdin to output and from input to stdout simultaneously.
1186  * Additionally filtering through given filter. If filter is NULL, uses
1187  * identity filter.
1188  */
1189 int bidirectional_transfer_loop(int input, int output)
1190 {
1191         struct bidirectional_transfer_state state;
1192
1193         /* Fill the state fields. */
1194         state.ptg.src = input;
1195         state.ptg.dest = 1;
1196         state.ptg.src_is_sock = (input == output);
1197         state.ptg.dest_is_sock = 0;
1198         state.ptg.state = SSTATE_TRANSFERING;
1199         state.ptg.bufuse = 0;
1200         state.ptg.src_name = "remote input";
1201         state.ptg.dest_name = "stdout";
1202
1203         state.gtp.src = 0;
1204         state.gtp.dest = output;
1205         state.gtp.src_is_sock = 0;
1206         state.gtp.dest_is_sock = (input == output);
1207         state.gtp.state = SSTATE_TRANSFERING;
1208         state.gtp.bufuse = 0;
1209         state.gtp.src_name = "stdin";
1210         state.gtp.dest_name = "remote output";
1211
1212         return tloop_spawnwait_tasks(&state);
1213 }