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 "remote.h"
   9 #include "string-list.h"
  10 #include "thread-utils.h"
  11 #include "sigchain.h"
  12 #include "argv-array.h"
  13 #include "refs.h"
  14
  15 static int debug;
  16
  17 struct helper_data {
  18         const char *name;
  19         struct child_process *helper;
  20         FILE *out;
  21         unsigned fetch : 1,
  22                 import : 1,
  23                 bidi_import : 1,
  24                 export : 1,
  25                 option : 1,
  26                 push : 1,
  27                 connect : 1,
  28                 signed_tags : 1,
  29                 check_connectivity : 1,
  30                 no_disconnect_req : 1,
  31                 no_private_update : 1;
  32         char *export_marks;
  33         char *import_marks;
  34         /* These go from remote name (as in "list") to private name */
  35         struct refspec *refspecs;
  36         int refspec_nr;
  37         /* Transport options for fetch-pack/send-pack (should one of
  38          * those be invoked).
  39          */
  40         struct git_transport_options transport_options;
  41 };
  42
  43 static void sendline(struct helper_data *helper, struct strbuf *buffer)
  44 {
  45         if (debug)
  46                 fprintf(stderr, "Debug: Remote helper: -> %s", buffer->buf);
  47         if (write_in_full(helper->helper->in, buffer->buf, buffer->len)
  48                 != buffer->len)
  49                 die_errno("Full write to remote helper failed");
  50 }
  51
  52 static int recvline_fh(FILE *helper, struct strbuf *buffer, const char *name)
  53 {
  54         strbuf_reset(buffer);
  55         if (debug)
  56                 fprintf(stderr, "Debug: Remote helper: Waiting...\n");
  57         if (strbuf_getline(buffer, helper) == EOF) {
  58                 if (debug)
  59                         fprintf(stderr, "Debug: Remote helper quit.\n");
  60                 return 1;
  61         }
  62
  63         if (debug)
  64                 fprintf(stderr, "Debug: Remote helper: <- %s\n", buffer->buf);
  65         return 0;
  66 }
  67
  68 static int recvline(struct helper_data *helper, struct strbuf *buffer)
  69 {
  70         return recvline_fh(helper->out, buffer, helper->name);
  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 void standard_options(struct transport *t);
 101
 102 static struct child_process *get_helper(struct transport *transport)
 103 {
 104         struct helper_data *data = transport->data;
 105         struct strbuf buf = STRBUF_INIT;
 106         struct child_process *helper;
 107         const char **refspecs = NULL;
 108         int refspec_nr = 0;
 109         int refspec_alloc = 0;
 110         int duped;
 111         int code;
 112
 113         if (data->helper)
 114                 return data->helper;
 115
 116         helper = xmalloc(sizeof(*helper));
 117         child_process_init(helper);
 118         helper->in = -1;
 119         helper->out = -1;
 120         helper->err = 0;
 121         argv_array_pushf(&helper->args, "git-remote-%s", data->name);
 122         argv_array_push(&helper->args, transport->remote->name);
 123         argv_array_push(&helper->args, remove_ext_force(transport->url));
 124         helper->git_cmd = 0;
 125         helper->silent_exec_failure = 1;
 126
 127         argv_array_pushf(&helper->env_array, "%s=%s", GIT_DIR_ENVIRONMENT,
 128                          get_git_dir());
 129
 130         code = start_command(helper);
 131         if (code < 0 && errno == ENOENT)
 132                 die("Unable to find remote helper for '%s'", data->name);
 133         else if (code != 0)
 134                 exit(code);
 135
 136         data->helper = helper;
 137         data->no_disconnect_req = 0;
 138
 139         /*
 140          * Open the output as FILE* so strbuf_getline_*() family of
 141          * functions can be used.
 142          * Do this with duped fd because fclose() will close the fd,
 143          * and stuff like taking over will require the fd to remain.
 144          */
 145         duped = dup(helper->out);
 146         if (duped < 0)
 147                 die_errno("Can't dup helper output fd");
 148         data->out = xfdopen(duped, "r");
 149
 150         write_constant(helper->in, "capabilities\n");
 151
 152         while (1) {
 153                 const char *capname, *arg;
 154                 int mandatory = 0;
 155                 if (recvline(data, &buf))
 156                         exit(128);
 157
 158                 if (!*buf.buf)
 159                         break;
 160
 161                 if (*buf.buf == '*') {
 162                         capname = buf.buf + 1;
 163                         mandatory = 1;
 164                 } else
 165                         capname = buf.buf;
 166
 167                 if (debug)
 168                         fprintf(stderr, "Debug: Got cap %s\n", capname);
 169                 if (!strcmp(capname, "fetch"))
 170                         data->fetch = 1;
 171                 else if (!strcmp(capname, "option"))
 172                         data->option = 1;
 173                 else if (!strcmp(capname, "push"))
 174                         data->push = 1;
 175                 else if (!strcmp(capname, "import"))
 176                         data->import = 1;
 177                 else if (!strcmp(capname, "bidi-import"))
 178                         data->bidi_import = 1;
 179                 else if (!strcmp(capname, "export"))
 180                         data->export = 1;
 181                 else if (!strcmp(capname, "check-connectivity"))
 182                         data->check_connectivity = 1;
 183                 else if (!data->refspecs && skip_prefix(capname, "refspec ", &arg)) {
 184                         ALLOC_GROW(refspecs,
 185                                    refspec_nr + 1,
 186                                    refspec_alloc);
 187                         refspecs[refspec_nr++] = xstrdup(arg);
 188                 } else if (!strcmp(capname, "connect")) {
 189                         data->connect = 1;
 190                 } else if (!strcmp(capname, "signed-tags")) {
 191                         data->signed_tags = 1;
 192                 } else if (skip_prefix(capname, "export-marks ", &arg)) {
 193                         data->export_marks = xstrdup(arg);
 194                 } else if (skip_prefix(capname, "import-marks ", &arg)) {
 195                         data->import_marks = xstrdup(arg);
 196                 } else if (starts_with(capname, "no-private-update")) {
 197                         data->no_private_update = 1;
 198                 } else if (mandatory) {
 199                         die("Unknown mandatory capability %s. This remote "
 200                             "helper probably needs newer version of Git.",
 201                             capname);
 202                 }
 203         }
 204         if (refspecs) {
 205                 int i;
 206                 data->refspec_nr = refspec_nr;
 207                 data->refspecs = parse_fetch_refspec(refspec_nr, refspecs);
 208                 for (i = 0; i < refspec_nr; i++)
 209                         free((char *)refspecs[i]);
 210                 free(refspecs);
 211         } else if (data->import || data->bidi_import || data->export) {
 212                 warning("This remote helper should implement refspec capability.");
 213         }
 214         strbuf_release(&buf);
 215         if (debug)
 216                 fprintf(stderr, "Debug: Capabilities complete.\n");
 217         standard_options(transport);
 218         return data->helper;
 219 }
 220
 221 static int disconnect_helper(struct transport *transport)
 222 {
 223         struct helper_data *data = transport->data;
 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                         /*
 231                          * Ignore write errors; there's nothing we can do,
 232                          * since we're about to close the pipe anyway. And the
 233                          * most likely error is EPIPE due to the helper dying
 234                          * to report an error itself.
 235                          */
 236                         sigchain_push(SIGPIPE, SIG_IGN);
 237                         xwrite(data->helper->in, "\n", 1);
 238                         sigchain_pop(SIGPIPE);
 239                 }
 240                 close(data->helper->in);
 241                 close(data->helper->out);
 242                 fclose(data->out);
 243                 res = finish_command(data->helper);
 244                 free(data->helper);
 245                 data->helper = NULL;
 246         }
 247         return res;
 248 }
 249
 250 static const char *unsupported_options[] = {
 251         TRANS_OPT_UPLOADPACK,
 252         TRANS_OPT_RECEIVEPACK,
 253         TRANS_OPT_THIN,
 254         TRANS_OPT_KEEP
 255         };
 256
 257 static const char *boolean_options[] = {
 258         TRANS_OPT_THIN,
 259         TRANS_OPT_KEEP,
 260         TRANS_OPT_FOLLOWTAGS,
 261         };
 262
 263 static int set_helper_option(struct transport *transport,
 264                           const char *name, const char *value)
 265 {
 266         struct helper_data *data = transport->data;
 267         struct strbuf buf = STRBUF_INIT;
 268         int i, ret, is_bool = 0;
 269
 270         get_helper(transport);
 271
 272         if (!data->option)
 273                 return 1;
 274
 275         for (i = 0; i < ARRAY_SIZE(unsupported_options); i++) {
 276                 if (!strcmp(name, unsupported_options[i]))
 277                         return 1;
 278         }
 279
 280         for (i = 0; i < ARRAY_SIZE(boolean_options); i++) {
 281                 if (!strcmp(name, boolean_options[i])) {
 282                         is_bool = 1;
 283                         break;
 284                 }
 285         }
 286
 287         strbuf_addf(&buf, "option %s ", name);
 288         if (is_bool)
 289                 strbuf_addstr(&buf, value ? "true" : "false");
 290         else
 291                 quote_c_style(value, &buf, NULL, 0);
 292         strbuf_addch(&buf, '\n');
 293
 294         sendline(data, &buf);
 295         if (recvline(data, &buf))
 296                 exit(128);
 297
 298         if (!strcmp(buf.buf, "ok"))
 299                 ret = 0;
 300         else if (starts_with(buf.buf, "error")) {
 301                 ret = -1;
 302         } else if (!strcmp(buf.buf, "unsupported"))
 303                 ret = 1;
 304         else {
 305                 warning("%s unexpectedly said: '%s'", data->name, buf.buf);
 306                 ret = 1;
 307         }
 308         strbuf_release(&buf);
 309         return ret;
 310 }
 311
 312 static void standard_options(struct transport *t)
 313 {
 314         char buf[16];
 315         int n;
 316         int v = t->verbose;
 317
 318         set_helper_option(t, "progress", t->progress ? "true" : "false");
 319
 320         n = snprintf(buf, sizeof(buf), "%d", v + 1);
 321         if (n >= sizeof(buf))
 322                 die("impossibly large verbosity value");
 323         set_helper_option(t, "verbosity", buf);
 324 }
 325
 326 static int release_helper(struct transport *transport)
 327 {
 328         int res = 0;
 329         struct helper_data *data = transport->data;
 330         free_refspec(data->refspec_nr, data->refspecs);
 331         data->refspecs = NULL;
 332         res = disconnect_helper(transport);
 333         free(transport->data);
 334         return res;
 335 }
 336
 337 static int fetch_with_fetch(struct transport *transport,
 338                             int nr_heads, struct ref **to_fetch)
 339 {
 340         struct helper_data *data = transport->data;
 341         int i;
 342         struct strbuf buf = STRBUF_INIT;
 343
 344         for (i = 0; i < nr_heads; i++) {
 345                 const struct ref *posn = to_fetch[i];
 346                 if (posn->status & REF_STATUS_UPTODATE)
 347                         continue;
 348
 349                 strbuf_addf(&buf, "fetch %s %s\n",
 350                             oid_to_hex(&posn->old_oid),
 351                             posn->symref ? posn->symref : posn->name);
 352         }
 353
 354         strbuf_addch(&buf, '\n');
 355         sendline(data, &buf);
 356
 357         while (1) {
 358                 if (recvline(data, &buf))
 359                         exit(128);
 360
 361                 if (starts_with(buf.buf, "lock ")) {
 362                         const char *name = buf.buf + 5;
 363                         if (transport->pack_lockfile)
 364                                 warning("%s also locked %s", data->name, name);
 365                         else
 366                                 transport->pack_lockfile = xstrdup(name);
 367                 }
 368                 else if (data->check_connectivity &&
 369                          data->transport_options.check_self_contained_and_connected &&
 370                          !strcmp(buf.buf, "connectivity-ok"))
 371                         data->transport_options.self_contained_and_connected = 1;
 372                 else if (!buf.len)
 373                         break;
 374                 else
 375                         warning("%s unexpectedly said: '%s'", data->name, buf.buf);
 376         }
 377         strbuf_release(&buf);
 378         return 0;
 379 }
 380
 381 static int get_importer(struct transport *transport, struct child_process *fastimport)
 382 {
 383         struct child_process *helper = get_helper(transport);
 384         struct helper_data *data = transport->data;
 385         int cat_blob_fd, code;
 386         child_process_init(fastimport);
 387         fastimport->in = helper->out;
 388         argv_array_push(&fastimport->args, "fast-import");
 389         argv_array_push(&fastimport->args, debug ? "--stats" : "--quiet");
 390
 391         if (data->bidi_import) {
 392                 cat_blob_fd = xdup(helper->in);
 393                 argv_array_pushf(&fastimport->args, "--cat-blob-fd=%d", cat_blob_fd);
 394         }
 395         fastimport->git_cmd = 1;
 396
 397         code = start_command(fastimport);
 398         return code;
 399 }
 400
 401 static int get_exporter(struct transport *transport,
 402                         struct child_process *fastexport,
 403                         struct string_list *revlist_args)
 404 {
 405         struct helper_data *data = transport->data;
 406         struct child_process *helper = get_helper(transport);
 407         int i;
 408
 409         child_process_init(fastexport);
 410
 411         /* we need to duplicate helper->in because we want to use it after
 412          * fastexport is done with it. */
 413         fastexport->out = dup(helper->in);
 414         argv_array_push(&fastexport->args, "fast-export");
 415         argv_array_push(&fastexport->args, "--use-done-feature");
 416         argv_array_push(&fastexport->args, data->signed_tags ?
 417                 "--signed-tags=verbatim" : "--signed-tags=warn-strip");
 418         if (data->export_marks)
 419                 argv_array_pushf(&fastexport->args, "--export-marks=%s.tmp", data->export_marks);
 420         if (data->import_marks)
 421                 argv_array_pushf(&fastexport->args, "--import-marks=%s", data->import_marks);
 422
 423         for (i = 0; i < revlist_args->nr; i++)
 424                 argv_array_push(&fastexport->args, revlist_args->items[i].string);
 425
 426         fastexport->git_cmd = 1;
 427         return start_command(fastexport);
 428 }
 429
 430 static int fetch_with_import(struct transport *transport,
 431                              int nr_heads, struct ref **to_fetch)
 432 {
 433         struct child_process fastimport;
 434         struct helper_data *data = transport->data;
 435         int i;
 436         struct ref *posn;
 437         struct strbuf buf = STRBUF_INIT;
 438
 439         get_helper(transport);
 440
 441         if (get_importer(transport, &fastimport))
 442                 die("Couldn't run fast-import");
 443
 444         for (i = 0; i < nr_heads; i++) {
 445                 posn = to_fetch[i];
 446                 if (posn->status & REF_STATUS_UPTODATE)
 447                         continue;
 448
 449                 strbuf_addf(&buf, "import %s\n",
 450                             posn->symref ? posn->symref : posn->name);
 451                 sendline(data, &buf);
 452                 strbuf_reset(&buf);
 453         }
 454
 455         write_constant(data->helper->in, "\n");
 456         /*
 457          * remote-helpers that advertise the bidi-import capability are required to
 458          * buffer the complete batch of import commands until this newline before
 459          * sending data to fast-import.
 460          * These helpers read back data from fast-import on their stdin, which could
 461          * be mixed with import commands, otherwise.
 462          */
 463
 464         if (finish_command(&fastimport))
 465                 die("Error while running fast-import");
 466
 467         /*
 468          * The fast-import stream of a remote helper that advertises
 469          * the "refspec" capability writes to the refs named after the
 470          * right hand side of the first refspec matching each ref we
 471          * were fetching.
 472          *
 473          * (If no "refspec" capability was specified, for historical
 474          * reasons we default to the equivalent of *:*.)
 475          *
 476          * Store the result in to_fetch[i].old_sha1.  Callers such
 477          * as "git fetch" can use the value to write feedback to the
 478          * terminal, populate FETCH_HEAD, and determine what new value
 479          * should be written to peer_ref if the update is a
 480          * fast-forward or this is a forced update.
 481          */
 482         for (i = 0; i < nr_heads; i++) {
 483                 char *private, *name;
 484                 posn = to_fetch[i];
 485                 if (posn->status & REF_STATUS_UPTODATE)
 486                         continue;
 487                 name = posn->symref ? posn->symref : posn->name;
 488                 if (data->refspecs)
 489                         private = apply_refspecs(data->refspecs, data->refspec_nr, name);
 490                 else
 491                         private = xstrdup(name);
 492                 if (private) {
 493                         if (read_ref(private, posn->old_oid.hash) < 0)
 494                                 die("Could not read ref %s", private);
 495                         free(private);
 496                 }
 497         }
 498         strbuf_release(&buf);
 499         return 0;
 500 }
 501
 502 static int process_connect_service(struct transport *transport,
 503                                    const char *name, const char *exec)
 504 {
 505         struct helper_data *data = transport->data;
 506         struct strbuf cmdbuf = STRBUF_INIT;
 507         struct child_process *helper;
 508         int r, duped, ret = 0;
 509         FILE *input;
 510
 511         helper = get_helper(transport);
 512
 513         /*
 514          * Yes, dup the pipe another time, as we need unbuffered version
 515          * of input pipe as FILE*. fclose() closes the underlying fd and
 516          * stream buffering only can be changed before first I/O operation
 517          * on it.
 518          */
 519         duped = dup(helper->out);
 520         if (duped < 0)
 521                 die_errno("Can't dup helper output fd");
 522         input = xfdopen(duped, "r");
 523         setvbuf(input, NULL, _IONBF, 0);
 524
 525         /*
 526          * Handle --upload-pack and friends. This is fire and forget...
 527          * just warn if it fails.
 528          */
 529         if (strcmp(name, exec)) {
 530                 r = set_helper_option(transport, "servpath", exec);
 531                 if (r > 0)
 532                         warning("Setting remote service path not supported by protocol.");
 533                 else if (r < 0)
 534                         warning("Invalid remote service path.");
 535         }
 536
 537         if (data->connect)
 538                 strbuf_addf(&cmdbuf, "connect %s\n", name);
 539         else
 540                 goto exit;
 541
 542         sendline(data, &cmdbuf);
 543         if (recvline_fh(input, &cmdbuf, name))
 544                 exit(128);
 545
 546         if (!strcmp(cmdbuf.buf, "")) {
 547                 data->no_disconnect_req = 1;
 548                 if (debug)
 549                         fprintf(stderr, "Debug: Smart transport connection "
 550                                 "ready.\n");
 551                 ret = 1;
 552         } else if (!strcmp(cmdbuf.buf, "fallback")) {
 553                 if (debug)
 554                         fprintf(stderr, "Debug: Falling back to dumb "
 555                                 "transport.\n");
 556         } else
 557                 die("Unknown response to connect: %s",
 558                         cmdbuf.buf);
 559
 560 exit:
 561         fclose(input);
 562         return ret;
 563 }
 564
 565 static int process_connect(struct transport *transport,
 566                                      int for_push)
 567 {
 568         struct helper_data *data = transport->data;
 569         const char *name;
 570         const char *exec;
 571
 572         name = for_push ? "git-receive-pack" : "git-upload-pack";
 573         if (for_push)
 574                 exec = data->transport_options.receivepack;
 575         else
 576                 exec = data->transport_options.uploadpack;
 577
 578         return process_connect_service(transport, name, exec);
 579 }
 580
 581 static int connect_helper(struct transport *transport, const char *name,
 582                    const char *exec, int fd[2])
 583 {
 584         struct helper_data *data = transport->data;
 585
 586         /* Get_helper so connect is inited. */
 587         get_helper(transport);
 588         if (!data->connect)
 589                 die("Operation not supported by protocol.");
 590
 591         if (!process_connect_service(transport, name, exec))
 592                 die("Can't connect to subservice %s.", name);
 593
 594         fd[0] = data->helper->out;
 595         fd[1] = data->helper->in;
 596         return 0;
 597 }
 598
 599 static int fetch(struct transport *transport,
 600                  int nr_heads, struct ref **to_fetch)
 601 {
 602         struct helper_data *data = transport->data;
 603         int i, count;
 604
 605         if (process_connect(transport, 0)) {
 606                 do_take_over(transport);
 607                 return transport->fetch(transport, nr_heads, to_fetch);
 608         }
 609
 610         count = 0;
 611         for (i = 0; i < nr_heads; i++)
 612                 if (!(to_fetch[i]->status & REF_STATUS_UPTODATE))
 613                         count++;
 614
 615         if (!count)
 616                 return 0;
 617
 618         if (data->check_connectivity &&
 619             data->transport_options.check_self_contained_and_connected)
 620                 set_helper_option(transport, "check-connectivity", "true");
 621
 622         if (transport->cloning)
 623                 set_helper_option(transport, "cloning", "true");
 624
 625         if (data->transport_options.update_shallow)
 626                 set_helper_option(transport, "update-shallow", "true");
 627
 628         if (data->fetch)
 629                 return fetch_with_fetch(transport, nr_heads, to_fetch);
 630
 631         if (data->import)
 632                 return fetch_with_import(transport, nr_heads, to_fetch);
 633
 634         return -1;
 635 }
 636
 637 static int push_update_ref_status(struct strbuf *buf,
 638                                    struct ref **ref,
 639                                    struct ref *remote_refs)
 640 {
 641         char *refname, *msg;
 642         int status, forced = 0;
 643
 644         if (starts_with(buf->buf, "ok ")) {
 645                 status = REF_STATUS_OK;
 646                 refname = buf->buf + 3;
 647         } else if (starts_with(buf->buf, "error ")) {
 648                 status = REF_STATUS_REMOTE_REJECT;
 649                 refname = buf->buf + 6;
 650         } else
 651                 die("expected ok/error, helper said '%s'", buf->buf);
 652
 653         msg = strchr(refname, ' ');
 654         if (msg) {
 655                 struct strbuf msg_buf = STRBUF_INIT;
 656                 const char *end;
 657
 658                 *msg++ = '\0';
 659                 if (!unquote_c_style(&msg_buf, msg, &end))
 660                         msg = strbuf_detach(&msg_buf, NULL);
 661                 else
 662                         msg = xstrdup(msg);
 663                 strbuf_release(&msg_buf);
 664
 665                 if (!strcmp(msg, "no match")) {
 666                         status = REF_STATUS_NONE;
 667                         free(msg);
 668                         msg = NULL;
 669                 }
 670                 else if (!strcmp(msg, "up to date")) {
 671                         status = REF_STATUS_UPTODATE;
 672                         free(msg);
 673                         msg = NULL;
 674                 }
 675                 else if (!strcmp(msg, "non-fast forward")) {
 676                         status = REF_STATUS_REJECT_NONFASTFORWARD;
 677                         free(msg);
 678                         msg = NULL;
 679                 }
 680                 else if (!strcmp(msg, "already exists")) {
 681                         status = REF_STATUS_REJECT_ALREADY_EXISTS;
 682                         free(msg);
 683                         msg = NULL;
 684                 }
 685                 else if (!strcmp(msg, "fetch first")) {
 686                         status = REF_STATUS_REJECT_FETCH_FIRST;
 687                         free(msg);
 688                         msg = NULL;
 689                 }
 690                 else if (!strcmp(msg, "needs force")) {
 691                         status = REF_STATUS_REJECT_NEEDS_FORCE;
 692                         free(msg);
 693                         msg = NULL;
 694                 }
 695                 else if (!strcmp(msg, "stale info")) {
 696                         status = REF_STATUS_REJECT_STALE;
 697                         free(msg);
 698                         msg = NULL;
 699                 }
 700                 else if (!strcmp(msg, "forced update")) {
 701                         forced = 1;
 702                         free(msg);
 703                         msg = NULL;
 704                 }
 705         }
 706
 707         if (*ref)
 708                 *ref = find_ref_by_name(*ref, refname);
 709         if (!*ref)
 710                 *ref = find_ref_by_name(remote_refs, refname);
 711         if (!*ref) {
 712                 warning("helper reported unexpected status of %s", refname);
 713                 return 1;
 714         }
 715
 716         if ((*ref)->status != REF_STATUS_NONE) {
 717                 /*
 718                  * Earlier, the ref was marked not to be pushed, so ignore the ref
 719                  * status reported by the remote helper if the latter is 'no match'.
 720                  */
 721                 if (status == REF_STATUS_NONE)
 722                         return 1;
 723         }
 724
 725         (*ref)->status = status;
 726         (*ref)->forced_update |= forced;
 727         (*ref)->remote_status = msg;
 728         return !(status == REF_STATUS_OK);
 729 }
 730
 731 static int push_update_refs_status(struct helper_data *data,
 732                                     struct ref *remote_refs,
 733                                     int flags)
 734 {
 735         struct strbuf buf = STRBUF_INIT;
 736         struct ref *ref = remote_refs;
 737         int ret = 0;
 738
 739         for (;;) {
 740                 char *private;
 741
 742                 if (recvline(data, &buf)) {
 743                         ret = 1;
 744                         break;
 745                 }
 746
 747                 if (!buf.len)
 748                         break;
 749
 750                 if (push_update_ref_status(&buf, &ref, remote_refs))
 751                         continue;
 752
 753                 if (flags & TRANSPORT_PUSH_DRY_RUN || !data->refspecs || data->no_private_update)
 754                         continue;
 755
 756                 /* propagate back the update to the remote namespace */
 757                 private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
 758                 if (!private)
 759                         continue;
 760                 update_ref("update by helper", private, ref->new_oid.hash, NULL, 0, 0);
 761                 free(private);
 762         }
 763         strbuf_release(&buf);
 764         return ret;
 765 }
 766
 767 static void set_common_push_options(struct transport *transport,
 768                                    const char *name, int flags)
 769 {
 770         if (flags & TRANSPORT_PUSH_DRY_RUN) {
 771                 if (set_helper_option(transport, "dry-run", "true") != 0)
 772                         die("helper %s does not support dry-run", name);
 773         } else if (flags & TRANSPORT_PUSH_CERT_ALWAYS) {
 774                 if (set_helper_option(transport, TRANS_OPT_PUSH_CERT, "true") != 0)
 775                         die("helper %s does not support --signed", name);
 776         } else if (flags & TRANSPORT_PUSH_CERT_IF_ASKED) {
 777                 if (set_helper_option(transport, TRANS_OPT_PUSH_CERT, "if-asked") != 0)
 778                         die("helper %s does not support --signed=if-asked", name);
 779         }
 780 }
 781
 782 static int push_refs_with_push(struct transport *transport,
 783                                struct ref *remote_refs, int flags)
 784 {
 785         int force_all = flags & TRANSPORT_PUSH_FORCE;
 786         int mirror = flags & TRANSPORT_PUSH_MIRROR;
 787         struct helper_data *data = transport->data;
 788         struct strbuf buf = STRBUF_INIT;
 789         struct ref *ref;
 790         struct string_list cas_options = STRING_LIST_INIT_DUP;
 791         struct string_list_item *cas_option;
 792
 793         get_helper(transport);
 794         if (!data->push)
 795                 return 1;
 796
 797         for (ref = remote_refs; ref; ref = ref->next) {
 798                 if (!ref->peer_ref && !mirror)
 799                         continue;
 800
 801                 /* Check for statuses set by set_ref_status_for_push() */
 802                 switch (ref->status) {
 803                 case REF_STATUS_REJECT_NONFASTFORWARD:
 804                 case REF_STATUS_REJECT_STALE:
 805                 case REF_STATUS_REJECT_ALREADY_EXISTS:
 806                 case REF_STATUS_UPTODATE:
 807                         continue;
 808                 default:
 809                         ; /* do nothing */
 810                 }
 811
 812                 if (force_all)
 813                         ref->force = 1;
 814
 815                 strbuf_addstr(&buf, "push ");
 816                 if (!ref->deletion) {
 817                         if (ref->force)
 818                                 strbuf_addch(&buf, '+');
 819                         if (ref->peer_ref)
 820                                 strbuf_addstr(&buf, ref->peer_ref->name);
 821                         else
 822                                 strbuf_addstr(&buf, oid_to_hex(&ref->new_oid));
 823                 }
 824                 strbuf_addch(&buf, ':');
 825                 strbuf_addstr(&buf, ref->name);
 826                 strbuf_addch(&buf, '\n');
 827
 828                 /*
 829                  * The "--force-with-lease" options without explicit
 830                  * values to expect have already been expanded into
 831                  * the ref->old_oid_expect[] field; we can ignore
 832                  * transport->smart_options->cas altogether and instead
 833                  * can enumerate them from the refs.
 834                  */
 835                 if (ref->expect_old_sha1) {
 836                         struct strbuf cas = STRBUF_INIT;
 837                         strbuf_addf(&cas, "%s:%s",
 838                                     ref->name, oid_to_hex(&ref->old_oid_expect));
 839                         string_list_append(&cas_options, strbuf_detach(&cas, NULL));
 840                 }
 841         }
 842         if (buf.len == 0) {
 843                 string_list_clear(&cas_options, 0);
 844                 return 0;
 845         }
 846
 847         for_each_string_list_item(cas_option, &cas_options)
 848                 set_helper_option(transport, "cas", cas_option->string);
 849         set_common_push_options(transport, data->name, flags);
 850
 851         strbuf_addch(&buf, '\n');
 852         sendline(data, &buf);
 853         strbuf_release(&buf);
 854
 855         return push_update_refs_status(data, remote_refs, flags);
 856 }
 857
 858 static int push_refs_with_export(struct transport *transport,
 859                 struct ref *remote_refs, int flags)
 860 {
 861         struct ref *ref;
 862         struct child_process *helper, exporter;
 863         struct helper_data *data = transport->data;
 864         struct string_list revlist_args = STRING_LIST_INIT_DUP;
 865         struct strbuf buf = STRBUF_INIT;
 866
 867         if (!data->refspecs)
 868                 die("remote-helper doesn't support push; refspec needed");
 869
 870         set_common_push_options(transport, data->name, flags);
 871         if (flags & TRANSPORT_PUSH_FORCE) {
 872                 if (set_helper_option(transport, "force", "true") != 0)
 873                         warning("helper %s does not support 'force'", data->name);
 874         }
 875
 876         helper = get_helper(transport);
 877
 878         write_constant(helper->in, "export\n");
 879
 880         for (ref = remote_refs; ref; ref = ref->next) {
 881                 char *private;
 882                 struct object_id oid;
 883
 884                 private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
 885                 if (private && !get_sha1(private, oid.hash)) {
 886                         strbuf_addf(&buf, "^%s", private);
 887                         string_list_append(&revlist_args, strbuf_detach(&buf, NULL));
 888                         oidcpy(&ref->old_oid, &oid);
 889                 }
 890                 free(private);
 891
 892                 if (ref->peer_ref) {
 893                         if (strcmp(ref->name, ref->peer_ref->name)) {
 894                                 if (!ref->deletion) {
 895                                         const char *name;
 896                                         int flag;
 897
 898                                         /* Follow symbolic refs (mainly for HEAD). */
 899                                         name = resolve_ref_unsafe(
 900                                                  ref->peer_ref->name,
 901                                                  RESOLVE_REF_READING,
 902                                                  oid.hash, &flag);
 903                                         if (!name || !(flag & REF_ISSYMREF))
 904                                                 name = ref->peer_ref->name;
 905
 906                                         strbuf_addf(&buf, "%s:%s", name, ref->name);
 907                                 } else
 908                                         strbuf_addf(&buf, ":%s", ref->name);
 909
 910                                 string_list_append(&revlist_args, "--refspec");
 911                                 string_list_append(&revlist_args, buf.buf);
 912                                 strbuf_release(&buf);
 913                         }
 914                         if (!ref->deletion)
 915                                 string_list_append(&revlist_args, ref->peer_ref->name);
 916                 }
 917         }
 918
 919         if (get_exporter(transport, &exporter, &revlist_args))
 920                 die("Couldn't run fast-export");
 921
 922         string_list_clear(&revlist_args, 1);
 923
 924         if (finish_command(&exporter))
 925                 die("Error while running fast-export");
 926         if (push_update_refs_status(data, remote_refs, flags))
 927                 return 1;
 928
 929         if (data->export_marks) {
 930                 strbuf_addf(&buf, "%s.tmp", data->export_marks);
 931                 rename(buf.buf, data->export_marks);
 932                 strbuf_release(&buf);
 933         }
 934
 935         return 0;
 936 }
 937
 938 static int push_refs(struct transport *transport,
 939                 struct ref *remote_refs, int flags)
 940 {
 941         struct helper_data *data = transport->data;
 942
 943         if (process_connect(transport, 1)) {
 944                 do_take_over(transport);
 945                 return transport->push_refs(transport, remote_refs, flags);
 946         }
 947
 948         if (!remote_refs) {
 949                 fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
 950                         "Perhaps you should specify a branch such as 'master'.\n");
 951                 return 0;
 952         }
 953
 954         if (data->push)
 955                 return push_refs_with_push(transport, remote_refs, flags);
 956
 957         if (data->export)
 958                 return push_refs_with_export(transport, remote_refs, flags);
 959
 960         return -1;
 961 }
 962
 963
 964 static int has_attribute(const char *attrs, const char *attr) {
 965         int len;
 966         if (!attrs)
 967                 return 0;
 968
 969         len = strlen(attr);
 970         for (;;) {
 971                 const char *space = strchrnul(attrs, ' ');
 972                 if (len == space - attrs && !strncmp(attrs, attr, len))
 973                         return 1;
 974                 if (!*space)
 975                         return 0;
 976                 attrs = space + 1;
 977         }
 978 }
 979
 980 static struct ref *get_refs_list(struct transport *transport, int for_push)
 981 {
 982         struct helper_data *data = transport->data;
 983         struct child_process *helper;
 984         struct ref *ret = NULL;
 985         struct ref **tail = &ret;
 986         struct ref *posn;
 987         struct strbuf buf = STRBUF_INIT;
 988
 989         helper = get_helper(transport);
 990
 991         if (process_connect(transport, for_push)) {
 992                 do_take_over(transport);
 993                 return transport->get_refs_list(transport, for_push);
 994         }
 995
 996         if (data->push && for_push)
 997                 write_str_in_full(helper->in, "list for-push\n");
 998         else
 999                 write_str_in_full(helper->in, "list\n");
1000
1001         while (1) {
1002                 char *eov, *eon;
1003                 if (recvline(data, &buf))
1004                         exit(128);
1005
1006                 if (!*buf.buf)
1007                         break;
1008
1009                 eov = strchr(buf.buf, ' ');
1010                 if (!eov)
1011                         die("Malformed response in ref list: %s", buf.buf);
1012                 eon = strchr(eov + 1, ' ');
1013                 *eov = '\0';
1014                 if (eon)
1015                         *eon = '\0';
1016                 *tail = alloc_ref(eov + 1);
1017                 if (buf.buf[0] == '@')
1018                         (*tail)->symref = xstrdup(buf.buf + 1);
1019                 else if (buf.buf[0] != '?')
1020                         get_oid_hex(buf.buf, &(*tail)->old_oid);
1021                 if (eon) {
1022                         if (has_attribute(eon + 1, "unchanged")) {
1023                                 (*tail)->status |= REF_STATUS_UPTODATE;
1024                                 if (read_ref((*tail)->name,
1025                                              (*tail)->old_oid.hash) < 0)
1026                                         die(N_("Could not read ref %s"),
1027                                             (*tail)->name);
1028                         }
1029                 }
1030                 tail = &((*tail)->next);
1031         }
1032         if (debug)
1033                 fprintf(stderr, "Debug: Read ref listing.\n");
1034         strbuf_release(&buf);
1035
1036         for (posn = ret; posn; posn = posn->next)
1037                 resolve_remote_symref(posn, ret);
1038
1039         return ret;
1040 }
1041
1042 int transport_helper_init(struct transport *transport, const char *name)
1043 {
1044         struct helper_data *data = xcalloc(1, sizeof(*data));
1045         data->name = name;
1046
1047         transport_check_allowed(name);
1048
1049         if (getenv("GIT_TRANSPORT_HELPER_DEBUG"))
1050                 debug = 1;
1051
1052         transport->data = data;
1053         transport->set_option = set_helper_option;
1054         transport->get_refs_list = get_refs_list;
1055         transport->fetch = fetch;
1056         transport->push_refs = push_refs;
1057         transport->disconnect = release_helper;
1058         transport->connect = connect_helper;
1059         transport->smart_options = &(data->transport_options);
1060         return 0;
1061 }
1062
1063 /*
1064  * Linux pipes can buffer 65536 bytes at once (and most platforms can
1065  * buffer less), so attempt reads and writes with up to that size.
1066  */
1067 #define BUFFERSIZE 65536
1068 /* This should be enough to hold debugging message. */
1069 #define PBUFFERSIZE 8192
1070
1071 /* Print bidirectional transfer loop debug message. */
1072 __attribute__((format (printf, 1, 2)))
1073 static void transfer_debug(const char *fmt, ...)
1074 {
1075         va_list args;
1076         char msgbuf[PBUFFERSIZE];
1077         static int debug_enabled = -1;
1078
1079         if (debug_enabled < 0)
1080                 debug_enabled = getenv("GIT_TRANSLOOP_DEBUG") ? 1 : 0;
1081         if (!debug_enabled)
1082                 return;
1083
1084         va_start(args, fmt);
1085         vsnprintf(msgbuf, PBUFFERSIZE, fmt, args);
1086         va_end(args);
1087         fprintf(stderr, "Transfer loop debugging: %s\n", msgbuf);
1088 }
1089
1090 /* Stream state: More data may be coming in this direction. */
1091 #define SSTATE_TRANSFERING 0
1092 /*
1093  * Stream state: No more data coming in this direction, flushing rest of
1094  * data.
1095  */
1096 #define SSTATE_FLUSHING 1
1097 /* Stream state: Transfer in this direction finished. */
1098 #define SSTATE_FINISHED 2
1099
1100 #define STATE_NEEDS_READING(state) ((state) <= SSTATE_TRANSFERING)
1101 #define STATE_NEEDS_WRITING(state) ((state) <= SSTATE_FLUSHING)
1102 #define STATE_NEEDS_CLOSING(state) ((state) == SSTATE_FLUSHING)
1103
1104 /* Unidirectional transfer. */
1105 struct unidirectional_transfer {
1106         /* Source */
1107         int src;
1108         /* Destination */
1109         int dest;
1110         /* Is source socket? */
1111         int src_is_sock;
1112         /* Is destination socket? */
1113         int dest_is_sock;
1114         /* Transfer state (TRANSFERRING/FLUSHING/FINISHED) */
1115         int state;
1116         /* Buffer. */
1117         char buf[BUFFERSIZE];
1118         /* Buffer used. */
1119         size_t bufuse;
1120         /* Name of source. */
1121         const char *src_name;
1122         /* Name of destination. */
1123         const char *dest_name;
1124 };
1125
1126 /* Closes the target (for writing) if transfer has finished. */
1127 static void udt_close_if_finished(struct unidirectional_transfer *t)
1128 {
1129         if (STATE_NEEDS_CLOSING(t->state) && !t->bufuse) {
1130                 t->state = SSTATE_FINISHED;
1131                 if (t->dest_is_sock)
1132                         shutdown(t->dest, SHUT_WR);
1133                 else
1134                         close(t->dest);
1135                 transfer_debug("Closed %s.", t->dest_name);
1136         }
1137 }
1138
1139 /*
1140  * Tries to read read data from source into buffer. If buffer is full,
1141  * no data is read. Returns 0 on success, -1 on error.
1142  */
1143 static int udt_do_read(struct unidirectional_transfer *t)
1144 {
1145         ssize_t bytes;
1146
1147         if (t->bufuse == BUFFERSIZE)
1148                 return 0;       /* No space for more. */
1149
1150         transfer_debug("%s is readable", t->src_name);
1151         bytes = read(t->src, t->buf + t->bufuse, BUFFERSIZE - t->bufuse);
1152         if (bytes < 0 && errno != EWOULDBLOCK && errno != EAGAIN &&
1153                 errno != EINTR) {
1154                 error("read(%s) failed: %s", t->src_name, strerror(errno));
1155                 return -1;
1156         } else if (bytes == 0) {
1157                 transfer_debug("%s EOF (with %i bytes in buffer)",
1158                         t->src_name, (int)t->bufuse);
1159                 t->state = SSTATE_FLUSHING;
1160         } else if (bytes > 0) {
1161                 t->bufuse += bytes;
1162                 transfer_debug("Read %i bytes from %s (buffer now at %i)",
1163                         (int)bytes, t->src_name, (int)t->bufuse);
1164         }
1165         return 0;
1166 }
1167
1168 /* Tries to write data from buffer into destination. If buffer is empty,
1169  * no data is written. Returns 0 on success, -1 on error.
1170  */
1171 static int udt_do_write(struct unidirectional_transfer *t)
1172 {
1173         ssize_t bytes;
1174
1175         if (t->bufuse == 0)
1176                 return 0;       /* Nothing to write. */
1177
1178         transfer_debug("%s is writable", t->dest_name);
1179         bytes = xwrite(t->dest, t->buf, t->bufuse);
1180         if (bytes < 0 && errno != EWOULDBLOCK) {
1181                 error("write(%s) failed: %s", t->dest_name, strerror(errno));
1182                 return -1;
1183         } else if (bytes > 0) {
1184                 t->bufuse -= bytes;
1185                 if (t->bufuse)
1186                         memmove(t->buf, t->buf + bytes, t->bufuse);
1187                 transfer_debug("Wrote %i bytes to %s (buffer now at %i)",
1188                         (int)bytes, t->dest_name, (int)t->bufuse);
1189         }
1190         return 0;
1191 }
1192
1193
1194 /* State of bidirectional transfer loop. */
1195 struct bidirectional_transfer_state {
1196         /* Direction from program to git. */
1197         struct unidirectional_transfer ptg;
1198         /* Direction from git to program. */
1199         struct unidirectional_transfer gtp;
1200 };
1201
1202 static void *udt_copy_task_routine(void *udt)
1203 {
1204         struct unidirectional_transfer *t = (struct unidirectional_transfer *)udt;
1205         while (t->state != SSTATE_FINISHED) {
1206                 if (STATE_NEEDS_READING(t->state))
1207                         if (udt_do_read(t))
1208                                 return NULL;
1209                 if (STATE_NEEDS_WRITING(t->state))
1210                         if (udt_do_write(t))
1211                                 return NULL;
1212                 if (STATE_NEEDS_CLOSING(t->state))
1213                         udt_close_if_finished(t);
1214         }
1215         return udt;     /* Just some non-NULL value. */
1216 }
1217
1218 #ifndef NO_PTHREADS
1219
1220 /*
1221  * Join thread, with appropriate errors on failure. Name is name for the
1222  * thread (for error messages). Returns 0 on success, 1 on failure.
1223  */
1224 static int tloop_join(pthread_t thread, const char *name)
1225 {
1226         int err;
1227         void *tret;
1228         err = pthread_join(thread, &tret);
1229         if (!tret) {
1230                 error("%s thread failed", name);
1231                 return 1;
1232         }
1233         if (err) {
1234                 error("%s thread failed to join: %s", name, strerror(err));
1235                 return 1;
1236         }
1237         return 0;
1238 }
1239
1240 /*
1241  * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1242  * -1 on failure.
1243  */
1244 static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1245 {
1246         pthread_t gtp_thread;
1247         pthread_t ptg_thread;
1248         int err;
1249         int ret = 0;
1250         err = pthread_create(&gtp_thread, NULL, udt_copy_task_routine,
1251                 &s->gtp);
1252         if (err)
1253                 die("Can't start thread for copying data: %s", strerror(err));
1254         err = pthread_create(&ptg_thread, NULL, udt_copy_task_routine,
1255                 &s->ptg);
1256         if (err)
1257                 die("Can't start thread for copying data: %s", strerror(err));
1258
1259         ret |= tloop_join(gtp_thread, "Git to program copy");
1260         ret |= tloop_join(ptg_thread, "Program to git copy");
1261         return ret;
1262 }
1263 #else
1264
1265 /* Close the source and target (for writing) for transfer. */
1266 static void udt_kill_transfer(struct unidirectional_transfer *t)
1267 {
1268         t->state = SSTATE_FINISHED;
1269         /*
1270          * Socket read end left open isn't a disaster if nobody
1271          * attempts to read from it (mingw compat headers do not
1272          * have SHUT_RD)...
1273          *
1274          * We can't fully close the socket since otherwise gtp
1275          * task would first close the socket it sends data to
1276          * while closing the ptg file descriptors.
1277          */
1278         if (!t->src_is_sock)
1279                 close(t->src);
1280         if (t->dest_is_sock)
1281                 shutdown(t->dest, SHUT_WR);
1282         else
1283                 close(t->dest);
1284 }
1285
1286 /*
1287  * Join process, with appropriate errors on failure. Name is name for the
1288  * process (for error messages). Returns 0 on success, 1 on failure.
1289  */
1290 static int tloop_join(pid_t pid, const char *name)
1291 {
1292         int tret;
1293         if (waitpid(pid, &tret, 0) < 0) {
1294                 error("%s process failed to wait: %s", name, strerror(errno));
1295                 return 1;
1296         }
1297         if (!WIFEXITED(tret) || WEXITSTATUS(tret)) {
1298                 error("%s process failed", name);
1299                 return 1;
1300         }
1301         return 0;
1302 }
1303
1304 /*
1305  * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1306  * -1 on failure.
1307  */
1308 static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1309 {
1310         pid_t pid1, pid2;
1311         int ret = 0;
1312
1313         /* Fork thread #1: git to program. */
1314         pid1 = fork();
1315         if (pid1 < 0)
1316                 die_errno("Can't start thread for copying data");
1317         else if (pid1 == 0) {
1318                 udt_kill_transfer(&s->ptg);
1319                 exit(udt_copy_task_routine(&s->gtp) ? 0 : 1);
1320         }
1321
1322         /* Fork thread #2: program to git. */
1323         pid2 = fork();
1324         if (pid2 < 0)
1325                 die_errno("Can't start thread for copying data");
1326         else if (pid2 == 0) {
1327                 udt_kill_transfer(&s->gtp);
1328                 exit(udt_copy_task_routine(&s->ptg) ? 0 : 1);
1329         }
1330
1331         /*
1332          * Close both streams in parent as to not interfere with
1333          * end of file detection and wait for both tasks to finish.
1334          */
1335         udt_kill_transfer(&s->gtp);
1336         udt_kill_transfer(&s->ptg);
1337         ret |= tloop_join(pid1, "Git to program copy");
1338         ret |= tloop_join(pid2, "Program to git copy");
1339         return ret;
1340 }
1341 #endif
1342
1343 /*
1344  * Copies data from stdin to output and from input to stdout simultaneously.
1345  * Additionally filtering through given filter. If filter is NULL, uses
1346  * identity filter.
1347  */
1348 int bidirectional_transfer_loop(int input, int output)
1349 {
1350         struct bidirectional_transfer_state state;
1351
1352         /* Fill the state fields. */
1353         state.ptg.src = input;
1354         state.ptg.dest = 1;
1355         state.ptg.src_is_sock = (input == output);
1356         state.ptg.dest_is_sock = 0;
1357         state.ptg.state = SSTATE_TRANSFERING;
1358         state.ptg.bufuse = 0;
1359         state.ptg.src_name = "remote input";
1360         state.ptg.dest_name = "stdout";
1361
1362         state.gtp.src = 0;
1363         state.gtp.dest = output;
1364         state.gtp.src_is_sock = 0;
1365         state.gtp.dest_is_sock = (input == output);
1366         state.gtp.state = SSTATE_TRANSFERING;
1367         state.gtp.bufuse = 0;
1368         state.gtp.src_name = "stdin";
1369         state.gtp.dest_name = "remote output";
1370
1371         return tloop_spawnwait_tasks(&state);
1372 }