git.oblomov.eu Git - git/blob - transport-helper.c

   1 #include "cache.h"
   2 #include "transport.h"
   3 #include "quote.h"
   4 #include "run-command.h"
   5 #include "commit.h"
   6 #include "diff.h"
   7 #include "revision.h"
   8 #include "quote.h"
   9 #include "remote.h"
  10 #include "string-list.h"
  11 #include "thread-utils.h"
  12 #include "sigchain.h"
  13 #include "argv-array.h"
  14 #include "refs.h"
  15
  16 static int debug;
  17
  18 struct helper_data {
  19         const char *name;
  20         struct child_process *helper;
  21         FILE *out;
  22         unsigned fetch : 1,
  23                 import : 1,
  24                 bidi_import : 1,
  25                 export : 1,
  26                 option : 1,
  27                 push : 1,
  28                 connect : 1,
  29                 signed_tags : 1,
  30                 check_connectivity : 1,
  31                 no_disconnect_req : 1,
  32                 no_private_update : 1;
  33         char *export_marks;
  34         char *import_marks;
  35         /* These go from remote name (as in "list") to private name */
  36         struct refspec *refspecs;
  37         int refspec_nr;
  38         /* Transport options for fetch-pack/send-pack (should one of
  39          * those be invoked).
  40          */
  41         struct git_transport_options transport_options;
  42 };
  43
  44 static void sendline(struct helper_data *helper, struct strbuf *buffer)
  45 {
  46         if (debug)
  47                 fprintf(stderr, "Debug: Remote helper: -> %s", buffer->buf);
  48         if (write_in_full(helper->helper->in, buffer->buf, buffer->len)
  49                 != buffer->len)
  50                 die_errno("Full write to remote helper failed");
  51 }
  52
  53 static int recvline_fh(FILE *helper, struct strbuf *buffer, const char *name)
  54 {
  55         strbuf_reset(buffer);
  56         if (debug)
  57                 fprintf(stderr, "Debug: Remote helper: Waiting...\n");
  58         if (strbuf_getline(buffer, helper, '\n') == EOF) {
  59                 if (debug)
  60                         fprintf(stderr, "Debug: Remote helper quit.\n");
  61                 return 1;
  62         }
  63
  64         if (debug)
  65                 fprintf(stderr, "Debug: Remote helper: <- %s\n", buffer->buf);
  66         return 0;
  67 }
  68
  69 static int recvline(struct helper_data *helper, struct strbuf *buffer)
  70 {
  71         return recvline_fh(helper->out, buffer, helper->name);
  72 }
  73
  74 static void write_constant(int fd, const char *str)
  75 {
  76         if (debug)
  77                 fprintf(stderr, "Debug: Remote helper: -> %s", str);
  78         if (write_in_full(fd, str, strlen(str)) != strlen(str))
  79                 die_errno("Full write to remote helper failed");
  80 }
  81
  82 static const char *remove_ext_force(const char *url)
  83 {
  84         if (url) {
  85                 const char *colon = strchr(url, ':');
  86                 if (colon && colon[1] == ':')
  87                         return colon + 2;
  88         }
  89         return url;
  90 }
  91
  92 static void do_take_over(struct transport *transport)
  93 {
  94         struct helper_data *data;
  95         data = (struct helper_data *)transport->data;
  96         transport_take_over(transport, data->helper);
  97         fclose(data->out);
  98         free(data);
  99 }
 100
 101 static struct child_process *get_helper(struct transport *transport)
 102 {
 103         struct helper_data *data = transport->data;
 104         struct strbuf buf = STRBUF_INIT;
 105         struct child_process *helper;
 106         const char **refspecs = NULL;
 107         int refspec_nr = 0;
 108         int refspec_alloc = 0;
 109         int duped;
 110         int code;
 111         char git_dir_buf[sizeof(GIT_DIR_ENVIRONMENT) + PATH_MAX + 1];
 112         const char *helper_env[] = {
 113                 git_dir_buf,
 114                 NULL
 115         };
 116
 117
 118         if (data->helper)
 119                 return data->helper;
 120
 121         helper = xcalloc(1, sizeof(*helper));
 122         helper->in = -1;
 123         helper->out = -1;
 124         helper->err = 0;
 125         argv_array_pushf(&helper->args, "git-remote-%s", data->name);
 126         argv_array_push(&helper->args, transport->remote->name);
 127         argv_array_push(&helper->args, remove_ext_force(transport->url));
 128         helper->git_cmd = 0;
 129         helper->silent_exec_failure = 1;
 130
 131         snprintf(git_dir_buf, sizeof(git_dir_buf), "%s=%s", GIT_DIR_ENVIRONMENT, get_git_dir());
 132         helper->env = helper_env;
 133
 134         code = start_command(helper);
 135         if (code < 0 && errno == ENOENT)
 136                 die("Unable to find remote helper for '%s'", data->name);
 137         else if (code != 0)
 138                 exit(code);
 139
 140         data->helper = helper;
 141         data->no_disconnect_req = 0;
 142
 143         /*
 144          * Open the output as FILE* so strbuf_getline() can be used.
 145          * Do this with duped fd because fclose() will close the fd,
 146          * and stuff like taking over will require the fd to remain.
 147          */
 148         duped = dup(helper->out);
 149         if (duped < 0)
 150                 die_errno("Can't dup helper output fd");
 151         data->out = xfdopen(duped, "r");
 152
 153         write_constant(helper->in, "capabilities\n");
 154
 155         while (1) {
 156                 const char *capname;
 157                 int mandatory = 0;
 158                 if (recvline(data, &buf))
 159                         exit(128);
 160
 161                 if (!*buf.buf)
 162                         break;
 163
 164                 if (*buf.buf == '*') {
 165                         capname = buf.buf + 1;
 166                         mandatory = 1;
 167                 } else
 168                         capname = buf.buf;
 169
 170                 if (debug)
 171                         fprintf(stderr, "Debug: Got cap %s\n", capname);
 172                 if (!strcmp(capname, "fetch"))
 173                         data->fetch = 1;
 174                 else if (!strcmp(capname, "option"))
 175                         data->option = 1;
 176                 else if (!strcmp(capname, "push"))
 177                         data->push = 1;
 178                 else if (!strcmp(capname, "import"))
 179                         data->import = 1;
 180                 else if (!strcmp(capname, "bidi-import"))
 181                         data->bidi_import = 1;
 182                 else if (!strcmp(capname, "export"))
 183                         data->export = 1;
 184                 else if (!strcmp(capname, "check-connectivity"))
 185                         data->check_connectivity = 1;
 186                 else if (!data->refspecs && starts_with(capname, "refspec ")) {
 187                         ALLOC_GROW(refspecs,
 188                                    refspec_nr + 1,
 189                                    refspec_alloc);
 190                         refspecs[refspec_nr++] = xstrdup(capname + strlen("refspec "));
 191                 } else if (!strcmp(capname, "connect")) {
 192                         data->connect = 1;
 193                 } else if (!strcmp(capname, "signed-tags")) {
 194                         data->signed_tags = 1;
 195                 } else if (starts_with(capname, "export-marks ")) {
 196                         data->export_marks = xstrdup(capname + strlen("export-marks "));
 197                 } else if (starts_with(capname, "import-marks")) {
 198                         data->import_marks = xstrdup(capname + strlen("import-marks "));
 199                 } else if (starts_with(capname, "no-private-update")) {
 200                         data->no_private_update = 1;
 201                 } else if (mandatory) {
 202                         die("Unknown mandatory capability %s. This remote "
 203                             "helper probably needs newer version of Git.",
 204                             capname);
 205                 }
 206         }
 207         if (refspecs) {
 208                 int i;
 209                 data->refspec_nr = refspec_nr;
 210                 data->refspecs = parse_fetch_refspec(refspec_nr, refspecs);
 211                 for (i = 0; i < refspec_nr; i++)
 212                         free((char *)refspecs[i]);
 213                 free(refspecs);
 214         } else if (data->import || data->bidi_import || data->export) {
 215                 warning("This remote helper should implement refspec capability.");
 216         }
 217         strbuf_release(&buf);
 218         if (debug)
 219                 fprintf(stderr, "Debug: Capabilities complete.\n");
 220         return data->helper;
 221 }
 222
 223 static int disconnect_helper(struct transport *transport)
 224 {
 225         struct helper_data *data = transport->data;
 226         int res = 0;
 227
 228         if (data->helper) {
 229                 if (debug)
 230                         fprintf(stderr, "Debug: Disconnecting.\n");
 231                 if (!data->no_disconnect_req) {
 232                         /*
 233                          * Ignore write errors; there's nothing we can do,
 234                          * since we're about to close the pipe anyway. And the
 235                          * most likely error is EPIPE due to the helper dying
 236                          * to report an error itself.
 237                          */
 238                         sigchain_push(SIGPIPE, SIG_IGN);
 239                         xwrite(data->helper->in, "\n", 1);
 240                         sigchain_pop(SIGPIPE);
 241                 }
 242                 close(data->helper->in);
 243                 close(data->helper->out);
 244                 fclose(data->out);
 245                 res = finish_command(data->helper);
 246                 free(data->helper);
 247                 data->helper = NULL;
 248         }
 249         return res;
 250 }
 251
 252 static const char *unsupported_options[] = {
 253         TRANS_OPT_UPLOADPACK,
 254         TRANS_OPT_RECEIVEPACK,
 255         TRANS_OPT_THIN,
 256         TRANS_OPT_KEEP
 257         };
 258
 259 static const char *boolean_options[] = {
 260         TRANS_OPT_THIN,
 261         TRANS_OPT_KEEP,
 262         TRANS_OPT_FOLLOWTAGS
 263         };
 264
 265 static int set_helper_option(struct transport *transport,
 266                           const char *name, const char *value)
 267 {
 268         struct helper_data *data = transport->data;
 269         struct strbuf buf = STRBUF_INIT;
 270         int i, ret, is_bool = 0;
 271
 272         get_helper(transport);
 273
 274         if (!data->option)
 275                 return 1;
 276
 277         for (i = 0; i < ARRAY_SIZE(unsupported_options); i++) {
 278                 if (!strcmp(name, unsupported_options[i]))
 279                         return 1;
 280         }
 281
 282         for (i = 0; i < ARRAY_SIZE(boolean_options); i++) {
 283                 if (!strcmp(name, boolean_options[i])) {
 284                         is_bool = 1;
 285                         break;
 286                 }
 287         }
 288
 289         strbuf_addf(&buf, "option %s ", name);
 290         if (is_bool)
 291                 strbuf_addstr(&buf, value ? "true" : "false");
 292         else
 293                 quote_c_style(value, &buf, NULL, 0);
 294         strbuf_addch(&buf, '\n');
 295
 296         sendline(data, &buf);
 297         if (recvline(data, &buf))
 298                 exit(128);
 299
 300         if (!strcmp(buf.buf, "ok"))
 301                 ret = 0;
 302         else if (starts_with(buf.buf, "error")) {
 303                 ret = -1;
 304         } else if (!strcmp(buf.buf, "unsupported"))
 305                 ret = 1;
 306         else {
 307                 warning("%s unexpectedly said: '%s'", data->name, buf.buf);
 308                 ret = 1;
 309         }
 310         strbuf_release(&buf);
 311         return ret;
 312 }
 313
 314 static void standard_options(struct transport *t)
 315 {
 316         char buf[16];
 317         int n;
 318         int v = t->verbose;
 319
 320         set_helper_option(t, "progress", t->progress ? "true" : "false");
 321
 322         n = snprintf(buf, sizeof(buf), "%d", v + 1);
 323         if (n >= sizeof(buf))
 324                 die("impossibly large verbosity value");
 325         set_helper_option(t, "verbosity", buf);
 326 }
 327
 328 static int release_helper(struct transport *transport)
 329 {
 330         int res = 0;
 331         struct helper_data *data = transport->data;
 332         free_refspec(data->refspec_nr, data->refspecs);
 333         data->refspecs = NULL;
 334         res = disconnect_helper(transport);
 335         free(transport->data);
 336         return res;
 337 }
 338
 339 static int fetch_with_fetch(struct transport *transport,
 340                             int nr_heads, struct ref **to_fetch)
 341 {
 342         struct helper_data *data = transport->data;
 343         int i;
 344         struct strbuf buf = STRBUF_INIT;
 345
 346         standard_options(transport);
 347         if (data->check_connectivity &&
 348             data->transport_options.check_self_contained_and_connected)
 349                 set_helper_option(transport, "check-connectivity", "true");
 350
 351         if (transport->cloning)
 352                 set_helper_option(transport, "cloning", "true");
 353
 354         if (data->transport_options.update_shallow)
 355                 set_helper_option(transport, "update-shallow", "true");
 356
 357         for (i = 0; i < nr_heads; i++) {
 358                 const struct ref *posn = to_fetch[i];
 359                 if (posn->status & REF_STATUS_UPTODATE)
 360                         continue;
 361
 362                 strbuf_addf(&buf, "fetch %s %s\n",
 363                             sha1_to_hex(posn->old_sha1), posn->name);
 364         }
 365
 366         strbuf_addch(&buf, '\n');
 367         sendline(data, &buf);
 368
 369         while (1) {
 370                 if (recvline(data, &buf))
 371                         exit(128);
 372
 373                 if (starts_with(buf.buf, "lock ")) {
 374                         const char *name = buf.buf + 5;
 375                         if (transport->pack_lockfile)
 376                                 warning("%s also locked %s", data->name, name);
 377                         else
 378                                 transport->pack_lockfile = xstrdup(name);
 379                 }
 380                 else if (data->check_connectivity &&
 381                          data->transport_options.check_self_contained_and_connected &&
 382                          !strcmp(buf.buf, "connectivity-ok"))
 383                         data->transport_options.self_contained_and_connected = 1;
 384                 else if (!buf.len)
 385                         break;
 386                 else
 387                         warning("%s unexpectedly said: '%s'", data->name, buf.buf);
 388         }
 389         strbuf_release(&buf);
 390         return 0;
 391 }
 392
 393 static int get_importer(struct transport *transport, struct child_process *fastimport)
 394 {
 395         struct child_process *helper = get_helper(transport);
 396         struct helper_data *data = transport->data;
 397         struct argv_array argv = ARGV_ARRAY_INIT;
 398         int cat_blob_fd, code;
 399         memset(fastimport, 0, sizeof(*fastimport));
 400         fastimport->in = helper->out;
 401         argv_array_push(&argv, "fast-import");
 402         argv_array_push(&argv, debug ? "--stats" : "--quiet");
 403
 404         if (data->bidi_import) {
 405                 cat_blob_fd = xdup(helper->in);
 406                 argv_array_pushf(&argv, "--cat-blob-fd=%d", cat_blob_fd);
 407         }
 408         fastimport->argv = argv.argv;
 409         fastimport->git_cmd = 1;
 410
 411         code = start_command(fastimport);
 412         return code;
 413 }
 414
 415 static int get_exporter(struct transport *transport,
 416                         struct child_process *fastexport,
 417                         struct string_list *revlist_args)
 418 {
 419         struct helper_data *data = transport->data;
 420         struct child_process *helper = get_helper(transport);
 421         int argc = 0, i;
 422         struct strbuf tmp = STRBUF_INIT;
 423
 424         memset(fastexport, 0, sizeof(*fastexport));
 425
 426         /* we need to duplicate helper->in because we want to use it after
 427          * fastexport is done with it. */
 428         fastexport->out = dup(helper->in);
 429         fastexport->argv = xcalloc(6 + revlist_args->nr, sizeof(*fastexport->argv));
 430         fastexport->argv[argc++] = "fast-export";
 431         fastexport->argv[argc++] = "--use-done-feature";
 432         fastexport->argv[argc++] = data->signed_tags ?
 433                 "--signed-tags=verbatim" : "--signed-tags=warn-strip";
 434         if (data->export_marks) {
 435                 strbuf_addf(&tmp, "--export-marks=%s.tmp", data->export_marks);
 436                 fastexport->argv[argc++] = strbuf_detach(&tmp, NULL);
 437         }
 438         if (data->import_marks) {
 439                 strbuf_addf(&tmp, "--import-marks=%s", data->import_marks);
 440                 fastexport->argv[argc++] = strbuf_detach(&tmp, NULL);
 441         }
 442
 443         for (i = 0; i < revlist_args->nr; i++)
 444                 fastexport->argv[argc++] = revlist_args->items[i].string;
 445
 446         fastexport->git_cmd = 1;
 447         return start_command(fastexport);
 448 }
 449
 450 static int fetch_with_import(struct transport *transport,
 451                              int nr_heads, struct ref **to_fetch)
 452 {
 453         struct child_process fastimport;
 454         struct helper_data *data = transport->data;
 455         int i;
 456         struct ref *posn;
 457         struct strbuf buf = STRBUF_INIT;
 458
 459         get_helper(transport);
 460
 461         if (get_importer(transport, &fastimport))
 462                 die("Couldn't run fast-import");
 463
 464         for (i = 0; i < nr_heads; i++) {
 465                 posn = to_fetch[i];
 466                 if (posn->status & REF_STATUS_UPTODATE)
 467                         continue;
 468
 469                 strbuf_addf(&buf, "import %s\n", posn->name);
 470                 sendline(data, &buf);
 471                 strbuf_reset(&buf);
 472         }
 473
 474         write_constant(data->helper->in, "\n");
 475         /*
 476          * remote-helpers that advertise the bidi-import capability are required to
 477          * buffer the complete batch of import commands until this newline before
 478          * sending data to fast-import.
 479          * These helpers read back data from fast-import on their stdin, which could
 480          * be mixed with import commands, otherwise.
 481          */
 482
 483         if (finish_command(&fastimport))
 484                 die("Error while running fast-import");
 485         argv_array_free_detached(fastimport.argv);
 486
 487         /*
 488          * The fast-import stream of a remote helper that advertises
 489          * the "refspec" capability writes to the refs named after the
 490          * right hand side of the first refspec matching each ref we
 491          * were fetching.
 492          *
 493          * (If no "refspec" capability was specified, for historical
 494          * reasons we default to the equivalent of *:*.)
 495          *
 496          * Store the result in to_fetch[i].old_sha1.  Callers such
 497          * as "git fetch" can use the value to write feedback to the
 498          * terminal, populate FETCH_HEAD, and determine what new value
 499          * should be written to peer_ref if the update is a
 500          * fast-forward or this is a forced update.
 501          */
 502         for (i = 0; i < nr_heads; i++) {
 503                 char *private;
 504                 posn = to_fetch[i];
 505                 if (posn->status & REF_STATUS_UPTODATE)
 506                         continue;
 507                 if (data->refspecs)
 508                         private = apply_refspecs(data->refspecs, data->refspec_nr, posn->name);
 509                 else
 510                         private = xstrdup(posn->name);
 511                 if (private) {
 512                         read_ref(private, posn->old_sha1);
 513                         free(private);
 514                 }
 515         }
 516         strbuf_release(&buf);
 517         return 0;
 518 }
 519
 520 static int process_connect_service(struct transport *transport,
 521                                    const char *name, const char *exec)
 522 {
 523         struct helper_data *data = transport->data;
 524         struct strbuf cmdbuf = STRBUF_INIT;
 525         struct child_process *helper;
 526         int r, duped, ret = 0;
 527         FILE *input;
 528
 529         helper = get_helper(transport);
 530
 531         /*
 532          * Yes, dup the pipe another time, as we need unbuffered version
 533          * of input pipe as FILE*. fclose() closes the underlying fd and
 534          * stream buffering only can be changed before first I/O operation
 535          * on it.
 536          */
 537         duped = dup(helper->out);
 538         if (duped < 0)
 539                 die_errno("Can't dup helper output fd");
 540         input = xfdopen(duped, "r");
 541         setvbuf(input, NULL, _IONBF, 0);
 542
 543         /*
 544          * Handle --upload-pack and friends. This is fire and forget...
 545          * just warn if it fails.
 546          */
 547         if (strcmp(name, exec)) {
 548                 r = set_helper_option(transport, "servpath", exec);
 549                 if (r > 0)
 550                         warning("Setting remote service path not supported by protocol.");
 551                 else if (r < 0)
 552                         warning("Invalid remote service path.");
 553         }
 554
 555         if (data->connect)
 556                 strbuf_addf(&cmdbuf, "connect %s\n", name);
 557         else
 558                 goto exit;
 559
 560         sendline(data, &cmdbuf);
 561         if (recvline_fh(input, &cmdbuf, name))
 562                 exit(128);
 563
 564         if (!strcmp(cmdbuf.buf, "")) {
 565                 data->no_disconnect_req = 1;
 566                 if (debug)
 567                         fprintf(stderr, "Debug: Smart transport connection "
 568                                 "ready.\n");
 569                 ret = 1;
 570         } else if (!strcmp(cmdbuf.buf, "fallback")) {
 571                 if (debug)
 572                         fprintf(stderr, "Debug: Falling back to dumb "
 573                                 "transport.\n");
 574         } else
 575                 die("Unknown response to connect: %s",
 576                         cmdbuf.buf);
 577
 578 exit:
 579         fclose(input);
 580         return ret;
 581 }
 582
 583 static int process_connect(struct transport *transport,
 584                                      int for_push)
 585 {
 586         struct helper_data *data = transport->data;
 587         const char *name;
 588         const char *exec;
 589
 590         name = for_push ? "git-receive-pack" : "git-upload-pack";
 591         if (for_push)
 592                 exec = data->transport_options.receivepack;
 593         else
 594                 exec = data->transport_options.uploadpack;
 595
 596         return process_connect_service(transport, name, exec);
 597 }
 598
 599 static int connect_helper(struct transport *transport, const char *name,
 600                    const char *exec, int fd[2])
 601 {
 602         struct helper_data *data = transport->data;
 603
 604         /* Get_helper so connect is inited. */
 605         get_helper(transport);
 606         if (!data->connect)
 607                 die("Operation not supported by protocol.");
 608
 609         if (!process_connect_service(transport, name, exec))
 610                 die("Can't connect to subservice %s.", name);
 611
 612         fd[0] = data->helper->out;
 613         fd[1] = data->helper->in;
 614         return 0;
 615 }
 616
 617 static int fetch(struct transport *transport,
 618                  int nr_heads, struct ref **to_fetch)
 619 {
 620         struct helper_data *data = transport->data;
 621         int i, count;
 622
 623         if (process_connect(transport, 0)) {
 624                 do_take_over(transport);
 625                 return transport->fetch(transport, nr_heads, to_fetch);
 626         }
 627
 628         count = 0;
 629         for (i = 0; i < nr_heads; i++)
 630                 if (!(to_fetch[i]->status & REF_STATUS_UPTODATE))
 631                         count++;
 632
 633         if (!count)
 634                 return 0;
 635
 636         if (data->fetch)
 637                 return fetch_with_fetch(transport, nr_heads, to_fetch);
 638
 639         if (data->import)
 640                 return fetch_with_import(transport, nr_heads, to_fetch);
 641
 642         return -1;
 643 }
 644
 645 static int push_update_ref_status(struct strbuf *buf,
 646                                    struct ref **ref,
 647                                    struct ref *remote_refs)
 648 {
 649         char *refname, *msg;
 650         int status, forced = 0;
 651
 652         if (starts_with(buf->buf, "ok ")) {
 653                 status = REF_STATUS_OK;
 654                 refname = buf->buf + 3;
 655         } else if (starts_with(buf->buf, "error ")) {
 656                 status = REF_STATUS_REMOTE_REJECT;
 657                 refname = buf->buf + 6;
 658         } else
 659                 die("expected ok/error, helper said '%s'", buf->buf);
 660
 661         msg = strchr(refname, ' ');
 662         if (msg) {
 663                 struct strbuf msg_buf = STRBUF_INIT;
 664                 const char *end;
 665
 666                 *msg++ = '\0';
 667                 if (!unquote_c_style(&msg_buf, msg, &end))
 668                         msg = strbuf_detach(&msg_buf, NULL);
 669                 else
 670                         msg = xstrdup(msg);
 671                 strbuf_release(&msg_buf);
 672
 673                 if (!strcmp(msg, "no match")) {
 674                         status = REF_STATUS_NONE;
 675                         free(msg);
 676                         msg = NULL;
 677                 }
 678                 else if (!strcmp(msg, "up to date")) {
 679                         status = REF_STATUS_UPTODATE;
 680                         free(msg);
 681                         msg = NULL;
 682                 }
 683                 else if (!strcmp(msg, "non-fast forward")) {
 684                         status = REF_STATUS_REJECT_NONFASTFORWARD;
 685                         free(msg);
 686                         msg = NULL;
 687                 }
 688                 else if (!strcmp(msg, "already exists")) {
 689                         status = REF_STATUS_REJECT_ALREADY_EXISTS;
 690                         free(msg);
 691                         msg = NULL;
 692                 }
 693                 else if (!strcmp(msg, "fetch first")) {
 694                         status = REF_STATUS_REJECT_FETCH_FIRST;
 695                         free(msg);
 696                         msg = NULL;
 697                 }
 698                 else if (!strcmp(msg, "needs force")) {
 699                         status = REF_STATUS_REJECT_NEEDS_FORCE;
 700                         free(msg);
 701                         msg = NULL;
 702                 }
 703                 else if (!strcmp(msg, "stale info")) {
 704                         status = REF_STATUS_REJECT_STALE;
 705                         free(msg);
 706                         msg = NULL;
 707                 }
 708                 else if (!strcmp(msg, "forced update")) {
 709                         forced = 1;
 710                         free(msg);
 711                         msg = NULL;
 712                 }
 713         }
 714
 715         if (*ref)
 716                 *ref = find_ref_by_name(*ref, refname);
 717         if (!*ref)
 718                 *ref = find_ref_by_name(remote_refs, refname);
 719         if (!*ref) {
 720                 warning("helper reported unexpected status of %s", refname);
 721                 return 1;
 722         }
 723
 724         if ((*ref)->status != REF_STATUS_NONE) {
 725                 /*
 726                  * Earlier, the ref was marked not to be pushed, so ignore the ref
 727                  * status reported by the remote helper if the latter is 'no match'.
 728                  */
 729                 if (status == REF_STATUS_NONE)
 730                         return 1;
 731         }
 732
 733         (*ref)->status = status;
 734         (*ref)->forced_update |= forced;
 735         (*ref)->remote_status = msg;
 736         return !(status == REF_STATUS_OK);
 737 }
 738
 739 static int push_update_refs_status(struct helper_data *data,
 740                                     struct ref *remote_refs,
 741                                     int flags)
 742 {
 743         struct strbuf buf = STRBUF_INIT;
 744         struct ref *ref = remote_refs;
 745         int ret = 0;
 746
 747         for (;;) {
 748                 char *private;
 749
 750                 if (recvline(data, &buf)) {
 751                         ret = 1;
 752                         break;
 753                 }
 754
 755                 if (!buf.len)
 756                         break;
 757
 758                 if (push_update_ref_status(&buf, &ref, remote_refs))
 759                         continue;
 760
 761                 if (flags & TRANSPORT_PUSH_DRY_RUN || !data->refspecs || data->no_private_update)
 762                         continue;
 763
 764                 /* propagate back the update to the remote namespace */
 765                 private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
 766                 if (!private)
 767                         continue;
 768                 update_ref("update by helper", private, ref->new_sha1, NULL, 0, 0);
 769                 free(private);
 770         }
 771         strbuf_release(&buf);
 772         return ret;
 773 }
 774
 775 static int push_refs_with_push(struct transport *transport,
 776                                struct ref *remote_refs, int flags)
 777 {
 778         int force_all = flags & TRANSPORT_PUSH_FORCE;
 779         int mirror = flags & TRANSPORT_PUSH_MIRROR;
 780         struct helper_data *data = transport->data;
 781         struct strbuf buf = STRBUF_INIT;
 782         struct ref *ref;
 783         struct string_list cas_options = STRING_LIST_INIT_DUP;
 784         struct string_list_item *cas_option;
 785
 786         get_helper(transport);
 787         if (!data->push)
 788                 return 1;
 789
 790         for (ref = remote_refs; ref; ref = ref->next) {
 791                 if (!ref->peer_ref && !mirror)
 792                         continue;
 793
 794                 /* Check for statuses set by set_ref_status_for_push() */
 795                 switch (ref->status) {
 796                 case REF_STATUS_REJECT_NONFASTFORWARD:
 797                 case REF_STATUS_REJECT_STALE:
 798                 case REF_STATUS_REJECT_ALREADY_EXISTS:
 799                 case REF_STATUS_UPTODATE:
 800                         continue;
 801                 default:
 802                         ; /* do nothing */
 803                 }
 804
 805                 if (force_all)
 806                         ref->force = 1;
 807
 808                 strbuf_addstr(&buf, "push ");
 809                 if (!ref->deletion) {
 810                         if (ref->force)
 811                                 strbuf_addch(&buf, '+');
 812                         if (ref->peer_ref)
 813                                 strbuf_addstr(&buf, ref->peer_ref->name);
 814                         else
 815                                 strbuf_addstr(&buf, sha1_to_hex(ref->new_sha1));
 816                 }
 817                 strbuf_addch(&buf, ':');
 818                 strbuf_addstr(&buf, ref->name);
 819                 strbuf_addch(&buf, '\n');
 820
 821                 /*
 822                  * The "--force-with-lease" options without explicit
 823                  * values to expect have already been expanded into
 824                  * the ref->old_sha1_expect[] field; we can ignore
 825                  * transport->smart_options->cas altogether and instead
 826                  * can enumerate them from the refs.
 827                  */
 828                 if (ref->expect_old_sha1) {
 829                         struct strbuf cas = STRBUF_INIT;
 830                         strbuf_addf(&cas, "%s:%s",
 831                                     ref->name, sha1_to_hex(ref->old_sha1_expect));
 832                         string_list_append(&cas_options, strbuf_detach(&cas, NULL));
 833                 }
 834         }
 835         if (buf.len == 0) {
 836                 string_list_clear(&cas_options, 0);
 837                 return 0;
 838         }
 839
 840         standard_options(transport);
 841         for_each_string_list_item(cas_option, &cas_options)
 842                 set_helper_option(transport, "cas", cas_option->string);
 843
 844         if (flags & TRANSPORT_PUSH_DRY_RUN) {
 845                 if (set_helper_option(transport, "dry-run", "true") != 0)
 846                         die("helper %s does not support dry-run", data->name);
 847         }
 848
 849         strbuf_addch(&buf, '\n');
 850         sendline(data, &buf);
 851         strbuf_release(&buf);
 852
 853         return push_update_refs_status(data, remote_refs, flags);
 854 }
 855
 856 static int push_refs_with_export(struct transport *transport,
 857                 struct ref *remote_refs, int flags)
 858 {
 859         struct ref *ref;
 860         struct child_process *helper, exporter;
 861         struct helper_data *data = transport->data;
 862         struct string_list revlist_args = STRING_LIST_INIT_NODUP;
 863         struct strbuf buf = STRBUF_INIT;
 864
 865         if (!data->refspecs)
 866                 die("remote-helper doesn't support push; refspec needed");
 867
 868         if (flags & TRANSPORT_PUSH_DRY_RUN) {
 869                 if (set_helper_option(transport, "dry-run", "true") != 0)
 870                         die("helper %s does not support dry-run", data->name);
 871         }
 872
 873         if (flags & TRANSPORT_PUSH_FORCE) {
 874                 if (set_helper_option(transport, "force", "true") != 0)
 875                         warning("helper %s does not support 'force'", data->name);
 876         }
 877
 878         helper = get_helper(transport);
 879
 880         write_constant(helper->in, "export\n");
 881
 882         strbuf_reset(&buf);
 883
 884         for (ref = remote_refs; ref; ref = ref->next) {
 885                 char *private;
 886                 unsigned char sha1[20];
 887
 888                 if (ref->deletion)
 889                         die("remote-helpers do not support ref deletion");
 890
 891                 private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
 892                 if (private && !get_sha1(private, sha1)) {
 893                         strbuf_addf(&buf, "^%s", private);
 894                         string_list_append(&revlist_args, strbuf_detach(&buf, NULL));
 895                         hashcpy(ref->old_sha1, sha1);
 896                 }
 897                 free(private);
 898
 899                 if (ref->peer_ref) {
 900                         if (strcmp(ref->peer_ref->name, ref->name))
 901                                 die("remote-helpers do not support old:new syntax");
 902                         string_list_append(&revlist_args, ref->peer_ref->name);
 903                 }
 904         }
 905
 906         if (get_exporter(transport, &exporter, &revlist_args))
 907                 die("Couldn't run fast-export");
 908
 909         if (finish_command(&exporter))
 910                 die("Error while running fast-export");
 911         if (push_update_refs_status(data, remote_refs, flags))
 912                 return 1;
 913
 914         if (data->export_marks) {
 915                 strbuf_addf(&buf, "%s.tmp", data->export_marks);
 916                 rename(buf.buf, data->export_marks);
 917                 strbuf_release(&buf);
 918         }
 919
 920         return 0;
 921 }
 922
 923 static int push_refs(struct transport *transport,
 924                 struct ref *remote_refs, int flags)
 925 {
 926         struct helper_data *data = transport->data;
 927
 928         if (process_connect(transport, 1)) {
 929                 do_take_over(transport);
 930                 return transport->push_refs(transport, remote_refs, flags);
 931         }
 932
 933         if (!remote_refs) {
 934                 fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
 935                         "Perhaps you should specify a branch such as 'master'.\n");
 936                 return 0;
 937         }
 938
 939         if (data->push)
 940                 return push_refs_with_push(transport, remote_refs, flags);
 941
 942         if (data->export)
 943                 return push_refs_with_export(transport, remote_refs, flags);
 944
 945         return -1;
 946 }
 947
 948
 949 static int has_attribute(const char *attrs, const char *attr) {
 950         int len;
 951         if (!attrs)
 952                 return 0;
 953
 954         len = strlen(attr);
 955         for (;;) {
 956                 const char *space = strchrnul(attrs, ' ');
 957                 if (len == space - attrs && !strncmp(attrs, attr, len))
 958                         return 1;
 959                 if (!*space)
 960                         return 0;
 961                 attrs = space + 1;
 962         }
 963 }
 964
 965 static struct ref *get_refs_list(struct transport *transport, int for_push)
 966 {
 967         struct helper_data *data = transport->data;
 968         struct child_process *helper;
 969         struct ref *ret = NULL;
 970         struct ref **tail = &ret;
 971         struct ref *posn;
 972         struct strbuf buf = STRBUF_INIT;
 973
 974         helper = get_helper(transport);
 975
 976         if (process_connect(transport, for_push)) {
 977                 do_take_over(transport);
 978                 return transport->get_refs_list(transport, for_push);
 979         }
 980
 981         if (data->push && for_push)
 982                 write_str_in_full(helper->in, "list for-push\n");
 983         else
 984                 write_str_in_full(helper->in, "list\n");
 985
 986         while (1) {
 987                 char *eov, *eon;
 988                 if (recvline(data, &buf))
 989                         exit(128);
 990
 991                 if (!*buf.buf)
 992                         break;
 993
 994                 eov = strchr(buf.buf, ' ');
 995                 if (!eov)
 996                         die("Malformed response in ref list: %s", buf.buf);
 997                 eon = strchr(eov + 1, ' ');
 998                 *eov = '\0';
 999                 if (eon)
1000                         *eon = '\0';
1001                 *tail = alloc_ref(eov + 1);
1002                 if (buf.buf[0] == '@')
1003                         (*tail)->symref = xstrdup(buf.buf + 1);
1004                 else if (buf.buf[0] != '?')
1005                         get_sha1_hex(buf.buf, (*tail)->old_sha1);
1006                 if (eon) {
1007                         if (has_attribute(eon + 1, "unchanged")) {
1008                                 (*tail)->status |= REF_STATUS_UPTODATE;
1009                                 read_ref((*tail)->name, (*tail)->old_sha1);
1010                         }
1011                 }
1012                 tail = &((*tail)->next);
1013         }
1014         if (debug)
1015                 fprintf(stderr, "Debug: Read ref listing.\n");
1016         strbuf_release(&buf);
1017
1018         for (posn = ret; posn; posn = posn->next)
1019                 resolve_remote_symref(posn, ret);
1020
1021         return ret;
1022 }
1023
1024 int transport_helper_init(struct transport *transport, const char *name)
1025 {
1026         struct helper_data *data = xcalloc(sizeof(*data), 1);
1027         data->name = name;
1028
1029         if (getenv("GIT_TRANSPORT_HELPER_DEBUG"))
1030                 debug = 1;
1031
1032         transport->data = data;
1033         transport->set_option = set_helper_option;
1034         transport->get_refs_list = get_refs_list;
1035         transport->fetch = fetch;
1036         transport->push_refs = push_refs;
1037         transport->disconnect = release_helper;
1038         transport->connect = connect_helper;
1039         transport->smart_options = &(data->transport_options);
1040         return 0;
1041 }
1042
1043 /*
1044  * Linux pipes can buffer 65536 bytes at once (and most platforms can
1045  * buffer less), so attempt reads and writes with up to that size.
1046  */
1047 #define BUFFERSIZE 65536
1048 /* This should be enough to hold debugging message. */
1049 #define PBUFFERSIZE 8192
1050
1051 /* Print bidirectional transfer loop debug message. */
1052 __attribute__((format (printf, 1, 2)))
1053 static void transfer_debug(const char *fmt, ...)
1054 {
1055         va_list args;
1056         char msgbuf[PBUFFERSIZE];
1057         static int debug_enabled = -1;
1058
1059         if (debug_enabled < 0)
1060                 debug_enabled = getenv("GIT_TRANSLOOP_DEBUG") ? 1 : 0;
1061         if (!debug_enabled)
1062                 return;
1063
1064         va_start(args, fmt);
1065         vsnprintf(msgbuf, PBUFFERSIZE, fmt, args);
1066         va_end(args);
1067         fprintf(stderr, "Transfer loop debugging: %s\n", msgbuf);
1068 }
1069
1070 /* Stream state: More data may be coming in this direction. */
1071 #define SSTATE_TRANSFERING 0
1072 /*
1073  * Stream state: No more data coming in this direction, flushing rest of
1074  * data.
1075  */
1076 #define SSTATE_FLUSHING 1
1077 /* Stream state: Transfer in this direction finished. */
1078 #define SSTATE_FINISHED 2
1079
1080 #define STATE_NEEDS_READING(state) ((state) <= SSTATE_TRANSFERING)
1081 #define STATE_NEEDS_WRITING(state) ((state) <= SSTATE_FLUSHING)
1082 #define STATE_NEEDS_CLOSING(state) ((state) == SSTATE_FLUSHING)
1083
1084 /* Unidirectional transfer. */
1085 struct unidirectional_transfer {
1086         /* Source */
1087         int src;
1088         /* Destination */
1089         int dest;
1090         /* Is source socket? */
1091         int src_is_sock;
1092         /* Is destination socket? */
1093         int dest_is_sock;
1094         /* Transfer state (TRANSFERRING/FLUSHING/FINISHED) */
1095         int state;
1096         /* Buffer. */
1097         char buf[BUFFERSIZE];
1098         /* Buffer used. */
1099         size_t bufuse;
1100         /* Name of source. */
1101         const char *src_name;
1102         /* Name of destination. */
1103         const char *dest_name;
1104 };
1105
1106 /* Closes the target (for writing) if transfer has finished. */
1107 static void udt_close_if_finished(struct unidirectional_transfer *t)
1108 {
1109         if (STATE_NEEDS_CLOSING(t->state) && !t->bufuse) {
1110                 t->state = SSTATE_FINISHED;
1111                 if (t->dest_is_sock)
1112                         shutdown(t->dest, SHUT_WR);
1113                 else
1114                         close(t->dest);
1115                 transfer_debug("Closed %s.", t->dest_name);
1116         }
1117 }
1118
1119 /*
1120  * Tries to read read data from source into buffer. If buffer is full,
1121  * no data is read. Returns 0 on success, -1 on error.
1122  */
1123 static int udt_do_read(struct unidirectional_transfer *t)
1124 {
1125         ssize_t bytes;
1126
1127         if (t->bufuse == BUFFERSIZE)
1128                 return 0;       /* No space for more. */
1129
1130         transfer_debug("%s is readable", t->src_name);
1131         bytes = read(t->src, t->buf + t->bufuse, BUFFERSIZE - t->bufuse);
1132         if (bytes < 0 && errno != EWOULDBLOCK && errno != EAGAIN &&
1133                 errno != EINTR) {
1134                 error("read(%s) failed: %s", t->src_name, strerror(errno));
1135                 return -1;
1136         } else if (bytes == 0) {
1137                 transfer_debug("%s EOF (with %i bytes in buffer)",
1138                         t->src_name, (int)t->bufuse);
1139                 t->state = SSTATE_FLUSHING;
1140         } else if (bytes > 0) {
1141                 t->bufuse += bytes;
1142                 transfer_debug("Read %i bytes from %s (buffer now at %i)",
1143                         (int)bytes, t->src_name, (int)t->bufuse);
1144         }
1145         return 0;
1146 }
1147
1148 /* Tries to write data from buffer into destination. If buffer is empty,
1149  * no data is written. Returns 0 on success, -1 on error.
1150  */
1151 static int udt_do_write(struct unidirectional_transfer *t)
1152 {
1153         ssize_t bytes;
1154
1155         if (t->bufuse == 0)
1156                 return 0;       /* Nothing to write. */
1157
1158         transfer_debug("%s is writable", t->dest_name);
1159         bytes = xwrite(t->dest, t->buf, t->bufuse);
1160         if (bytes < 0 && errno != EWOULDBLOCK) {
1161                 error("write(%s) failed: %s", t->dest_name, strerror(errno));
1162                 return -1;
1163         } else if (bytes > 0) {
1164                 t->bufuse -= bytes;
1165                 if (t->bufuse)
1166                         memmove(t->buf, t->buf + bytes, t->bufuse);
1167                 transfer_debug("Wrote %i bytes to %s (buffer now at %i)",
1168                         (int)bytes, t->dest_name, (int)t->bufuse);
1169         }
1170         return 0;
1171 }
1172
1173
1174 /* State of bidirectional transfer loop. */
1175 struct bidirectional_transfer_state {
1176         /* Direction from program to git. */
1177         struct unidirectional_transfer ptg;
1178         /* Direction from git to program. */
1179         struct unidirectional_transfer gtp;
1180 };
1181
1182 static void *udt_copy_task_routine(void *udt)
1183 {
1184         struct unidirectional_transfer *t = (struct unidirectional_transfer *)udt;
1185         while (t->state != SSTATE_FINISHED) {
1186                 if (STATE_NEEDS_READING(t->state))
1187                         if (udt_do_read(t))
1188                                 return NULL;
1189                 if (STATE_NEEDS_WRITING(t->state))
1190                         if (udt_do_write(t))
1191                                 return NULL;
1192                 if (STATE_NEEDS_CLOSING(t->state))
1193                         udt_close_if_finished(t);
1194         }
1195         return udt;     /* Just some non-NULL value. */
1196 }
1197
1198 #ifndef NO_PTHREADS
1199
1200 /*
1201  * Join thread, with appropriate errors on failure. Name is name for the
1202  * thread (for error messages). Returns 0 on success, 1 on failure.
1203  */
1204 static int tloop_join(pthread_t thread, const char *name)
1205 {
1206         int err;
1207         void *tret;
1208         err = pthread_join(thread, &tret);
1209         if (!tret) {
1210                 error("%s thread failed", name);
1211                 return 1;
1212         }
1213         if (err) {
1214                 error("%s thread failed to join: %s", name, strerror(err));
1215                 return 1;
1216         }
1217         return 0;
1218 }
1219
1220 /*
1221  * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1222  * -1 on failure.
1223  */
1224 static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1225 {
1226         pthread_t gtp_thread;
1227         pthread_t ptg_thread;
1228         int err;
1229         int ret = 0;
1230         err = pthread_create(&gtp_thread, NULL, udt_copy_task_routine,
1231                 &s->gtp);
1232         if (err)
1233                 die("Can't start thread for copying data: %s", strerror(err));
1234         err = pthread_create(&ptg_thread, NULL, udt_copy_task_routine,
1235                 &s->ptg);
1236         if (err)
1237                 die("Can't start thread for copying data: %s", strerror(err));
1238
1239         ret |= tloop_join(gtp_thread, "Git to program copy");
1240         ret |= tloop_join(ptg_thread, "Program to git copy");
1241         return ret;
1242 }
1243 #else
1244
1245 /* Close the source and target (for writing) for transfer. */
1246 static void udt_kill_transfer(struct unidirectional_transfer *t)
1247 {
1248         t->state = SSTATE_FINISHED;
1249         /*
1250          * Socket read end left open isn't a disaster if nobody
1251          * attempts to read from it (mingw compat headers do not
1252          * have SHUT_RD)...
1253          *
1254          * We can't fully close the socket since otherwise gtp
1255          * task would first close the socket it sends data to
1256          * while closing the ptg file descriptors.
1257          */
1258         if (!t->src_is_sock)
1259                 close(t->src);
1260         if (t->dest_is_sock)
1261                 shutdown(t->dest, SHUT_WR);
1262         else
1263                 close(t->dest);
1264 }
1265
1266 /*
1267  * Join process, with appropriate errors on failure. Name is name for the
1268  * process (for error messages). Returns 0 on success, 1 on failure.
1269  */
1270 static int tloop_join(pid_t pid, const char *name)
1271 {
1272         int tret;
1273         if (waitpid(pid, &tret, 0) < 0) {
1274                 error("%s process failed to wait: %s", name, strerror(errno));
1275                 return 1;
1276         }
1277         if (!WIFEXITED(tret) || WEXITSTATUS(tret)) {
1278                 error("%s process failed", name);
1279                 return 1;
1280         }
1281         return 0;
1282 }
1283
1284 /*
1285  * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1286  * -1 on failure.
1287  */
1288 static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1289 {
1290         pid_t pid1, pid2;
1291         int ret = 0;
1292
1293         /* Fork thread #1: git to program. */
1294         pid1 = fork();
1295         if (pid1 < 0)
1296                 die_errno("Can't start thread for copying data");
1297         else if (pid1 == 0) {
1298                 udt_kill_transfer(&s->ptg);
1299                 exit(udt_copy_task_routine(&s->gtp) ? 0 : 1);
1300         }
1301
1302         /* Fork thread #2: program to git. */
1303         pid2 = fork();
1304         if (pid2 < 0)
1305                 die_errno("Can't start thread for copying data");
1306         else if (pid2 == 0) {
1307                 udt_kill_transfer(&s->gtp);
1308                 exit(udt_copy_task_routine(&s->ptg) ? 0 : 1);
1309         }
1310
1311         /*
1312          * Close both streams in parent as to not interfere with
1313          * end of file detection and wait for both tasks to finish.
1314          */
1315         udt_kill_transfer(&s->gtp);
1316         udt_kill_transfer(&s->ptg);
1317         ret |= tloop_join(pid1, "Git to program copy");
1318         ret |= tloop_join(pid2, "Program to git copy");
1319         return ret;
1320 }
1321 #endif
1322
1323 /*
1324  * Copies data from stdin to output and from input to stdout simultaneously.
1325  * Additionally filtering through given filter. If filter is NULL, uses
1326  * identity filter.
1327  */
1328 int bidirectional_transfer_loop(int input, int output)
1329 {
1330         struct bidirectional_transfer_state state;
1331
1332         /* Fill the state fields. */
1333         state.ptg.src = input;
1334         state.ptg.dest = 1;
1335         state.ptg.src_is_sock = (input == output);
1336         state.ptg.dest_is_sock = 0;
1337         state.ptg.state = SSTATE_TRANSFERING;
1338         state.ptg.bufuse = 0;
1339         state.ptg.src_name = "remote input";
1340         state.ptg.dest_name = "stdout";
1341
1342         state.gtp.src = 0;
1343         state.gtp.dest = output;
1344         state.gtp.src_is_sock = 0;
1345         state.gtp.dest_is_sock = (input == output);
1346         state.gtp.state = SSTATE_TRANSFERING;
1347         state.gtp.bufuse = 0;
1348         state.gtp.src_name = "stdin";
1349         state.gtp.dest_name = "remote output";
1350
1351         return tloop_spawnwait_tasks(&state);
1352 }