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 = xmalloc(sizeof(*helper));
 122         child_process_init(helper);
 123         helper->in = -1;
 124         helper->out = -1;
 125         helper->err = 0;
 126         argv_array_pushf(&helper->args, "git-remote-%s", data->name);
 127         argv_array_push(&helper->args, transport->remote->name);
 128         argv_array_push(&helper->args, remove_ext_force(transport->url));
 129         helper->git_cmd = 0;
 130         helper->silent_exec_failure = 1;
 131
 132         snprintf(git_dir_buf, sizeof(git_dir_buf), "%s=%s", GIT_DIR_ENVIRONMENT, get_git_dir());
 133         helper->env = helper_env;
 134
 135         code = start_command(helper);
 136         if (code < 0 && errno == ENOENT)
 137                 die("Unable to find remote helper for '%s'", data->name);
 138         else if (code != 0)
 139                 exit(code);
 140
 141         data->helper = helper;
 142         data->no_disconnect_req = 0;
 143
 144         /*
 145          * Open the output as FILE* so strbuf_getline() can be used.
 146          * Do this with duped fd because fclose() will close the fd,
 147          * and stuff like taking over will require the fd to remain.
 148          */
 149         duped = dup(helper->out);
 150         if (duped < 0)
 151                 die_errno("Can't dup helper output fd");
 152         data->out = xfdopen(duped, "r");
 153
 154         write_constant(helper->in, "capabilities\n");
 155
 156         while (1) {
 157                 const char *capname, *arg;
 158                 int mandatory = 0;
 159                 if (recvline(data, &buf))
 160                         exit(128);
 161
 162                 if (!*buf.buf)
 163                         break;
 164
 165                 if (*buf.buf == '*') {
 166                         capname = buf.buf + 1;
 167                         mandatory = 1;
 168                 } else
 169                         capname = buf.buf;
 170
 171                 if (debug)
 172                         fprintf(stderr, "Debug: Got cap %s\n", capname);
 173                 if (!strcmp(capname, "fetch"))
 174                         data->fetch = 1;
 175                 else if (!strcmp(capname, "option"))
 176                         data->option = 1;
 177                 else if (!strcmp(capname, "push"))
 178                         data->push = 1;
 179                 else if (!strcmp(capname, "import"))
 180                         data->import = 1;
 181                 else if (!strcmp(capname, "bidi-import"))
 182                         data->bidi_import = 1;
 183                 else if (!strcmp(capname, "export"))
 184                         data->export = 1;
 185                 else if (!strcmp(capname, "check-connectivity"))
 186                         data->check_connectivity = 1;
 187                 else if (!data->refspecs && skip_prefix(capname, "refspec ", &arg)) {
 188                         ALLOC_GROW(refspecs,
 189                                    refspec_nr + 1,
 190                                    refspec_alloc);
 191                         refspecs[refspec_nr++] = xstrdup(arg);
 192                 } else if (!strcmp(capname, "connect")) {
 193                         data->connect = 1;
 194                 } else if (!strcmp(capname, "signed-tags")) {
 195                         data->signed_tags = 1;
 196                 } else if (skip_prefix(capname, "export-marks ", &arg)) {
 197                         data->export_marks = xstrdup(arg);
 198                 } else if (skip_prefix(capname, "import-marks ", &arg)) {
 199                         data->import_marks = xstrdup(arg);
 200                 } else if (starts_with(capname, "no-private-update")) {
 201                         data->no_private_update = 1;
 202                 } else if (mandatory) {
 203                         die("Unknown mandatory capability %s. This remote "
 204                             "helper probably needs newer version of Git.",
 205                             capname);
 206                 }
 207         }
 208         if (refspecs) {
 209                 int i;
 210                 data->refspec_nr = refspec_nr;
 211                 data->refspecs = parse_fetch_refspec(refspec_nr, refspecs);
 212                 for (i = 0; i < refspec_nr; i++)
 213                         free((char *)refspecs[i]);
 214                 free(refspecs);
 215         } else if (data->import || data->bidi_import || data->export) {
 216                 warning("This remote helper should implement refspec capability.");
 217         }
 218         strbuf_release(&buf);
 219         if (debug)
 220                 fprintf(stderr, "Debug: Capabilities complete.\n");
 221         return data->helper;
 222 }
 223
 224 static int disconnect_helper(struct transport *transport)
 225 {
 226         struct helper_data *data = transport->data;
 227         int res = 0;
 228
 229         if (data->helper) {
 230                 if (debug)
 231                         fprintf(stderr, "Debug: Disconnecting.\n");
 232                 if (!data->no_disconnect_req) {
 233                         /*
 234                          * Ignore write errors; there's nothing we can do,
 235                          * since we're about to close the pipe anyway. And the
 236                          * most likely error is EPIPE due to the helper dying
 237                          * to report an error itself.
 238                          */
 239                         sigchain_push(SIGPIPE, SIG_IGN);
 240                         xwrite(data->helper->in, "\n", 1);
 241                         sigchain_pop(SIGPIPE);
 242                 }
 243                 close(data->helper->in);
 244                 close(data->helper->out);
 245                 fclose(data->out);
 246                 res = finish_command(data->helper);
 247                 free(data->helper);
 248                 data->helper = NULL;
 249         }
 250         return res;
 251 }
 252
 253 static const char *unsupported_options[] = {
 254         TRANS_OPT_UPLOADPACK,
 255         TRANS_OPT_RECEIVEPACK,
 256         TRANS_OPT_THIN,
 257         TRANS_OPT_KEEP
 258         };
 259
 260 static const char *boolean_options[] = {
 261         TRANS_OPT_THIN,
 262         TRANS_OPT_KEEP,
 263         TRANS_OPT_FOLLOWTAGS,
 264         TRANS_OPT_PUSH_CERT
 265         };
 266
 267 static int set_helper_option(struct transport *transport,
 268                           const char *name, const char *value)
 269 {
 270         struct helper_data *data = transport->data;
 271         struct strbuf buf = STRBUF_INIT;
 272         int i, ret, is_bool = 0;
 273
 274         get_helper(transport);
 275
 276         if (!data->option)
 277                 return 1;
 278
 279         for (i = 0; i < ARRAY_SIZE(unsupported_options); i++) {
 280                 if (!strcmp(name, unsupported_options[i]))
 281                         return 1;
 282         }
 283
 284         for (i = 0; i < ARRAY_SIZE(boolean_options); i++) {
 285                 if (!strcmp(name, boolean_options[i])) {
 286                         is_bool = 1;
 287                         break;
 288                 }
 289         }
 290
 291         strbuf_addf(&buf, "option %s ", name);
 292         if (is_bool)
 293                 strbuf_addstr(&buf, value ? "true" : "false");
 294         else
 295                 quote_c_style(value, &buf, NULL, 0);
 296         strbuf_addch(&buf, '\n');
 297
 298         sendline(data, &buf);
 299         if (recvline(data, &buf))
 300                 exit(128);
 301
 302         if (!strcmp(buf.buf, "ok"))
 303                 ret = 0;
 304         else if (starts_with(buf.buf, "error")) {
 305                 ret = -1;
 306         } else if (!strcmp(buf.buf, "unsupported"))
 307                 ret = 1;
 308         else {
 309                 warning("%s unexpectedly said: '%s'", data->name, buf.buf);
 310                 ret = 1;
 311         }
 312         strbuf_release(&buf);
 313         return ret;
 314 }
 315
 316 static void standard_options(struct transport *t)
 317 {
 318         char buf[16];
 319         int n;
 320         int v = t->verbose;
 321
 322         set_helper_option(t, "progress", t->progress ? "true" : "false");
 323
 324         n = snprintf(buf, sizeof(buf), "%d", v + 1);
 325         if (n >= sizeof(buf))
 326                 die("impossibly large verbosity value");
 327         set_helper_option(t, "verbosity", buf);
 328 }
 329
 330 static int release_helper(struct transport *transport)
 331 {
 332         int res = 0;
 333         struct helper_data *data = transport->data;
 334         free_refspec(data->refspec_nr, data->refspecs);
 335         data->refspecs = NULL;
 336         res = disconnect_helper(transport);
 337         free(transport->data);
 338         return res;
 339 }
 340
 341 static int fetch_with_fetch(struct transport *transport,
 342                             int nr_heads, struct ref **to_fetch)
 343 {
 344         struct helper_data *data = transport->data;
 345         int i;
 346         struct strbuf buf = STRBUF_INIT;
 347
 348         standard_options(transport);
 349         if (data->check_connectivity &&
 350             data->transport_options.check_self_contained_and_connected)
 351                 set_helper_option(transport, "check-connectivity", "true");
 352
 353         if (transport->cloning)
 354                 set_helper_option(transport, "cloning", "true");
 355
 356         if (data->transport_options.update_shallow)
 357                 set_helper_option(transport, "update-shallow", "true");
 358
 359         for (i = 0; i < nr_heads; i++) {
 360                 const struct ref *posn = to_fetch[i];
 361                 if (posn->status & REF_STATUS_UPTODATE)
 362                         continue;
 363
 364                 strbuf_addf(&buf, "fetch %s %s\n",
 365                             sha1_to_hex(posn->old_sha1), posn->name);
 366         }
 367
 368         strbuf_addch(&buf, '\n');
 369         sendline(data, &buf);
 370
 371         while (1) {
 372                 if (recvline(data, &buf))
 373                         exit(128);
 374
 375                 if (starts_with(buf.buf, "lock ")) {
 376                         const char *name = buf.buf + 5;
 377                         if (transport->pack_lockfile)
 378                                 warning("%s also locked %s", data->name, name);
 379                         else
 380                                 transport->pack_lockfile = xstrdup(name);
 381                 }
 382                 else if (data->check_connectivity &&
 383                          data->transport_options.check_self_contained_and_connected &&
 384                          !strcmp(buf.buf, "connectivity-ok"))
 385                         data->transport_options.self_contained_and_connected = 1;
 386                 else if (!buf.len)
 387                         break;
 388                 else
 389                         warning("%s unexpectedly said: '%s'", data->name, buf.buf);
 390         }
 391         strbuf_release(&buf);
 392         return 0;
 393 }
 394
 395 static int get_importer(struct transport *transport, struct child_process *fastimport)
 396 {
 397         struct child_process *helper = get_helper(transport);
 398         struct helper_data *data = transport->data;
 399         int cat_blob_fd, code;
 400         child_process_init(fastimport);
 401         fastimport->in = helper->out;
 402         argv_array_push(&fastimport->args, "fast-import");
 403         argv_array_push(&fastimport->args, debug ? "--stats" : "--quiet");
 404
 405         if (data->bidi_import) {
 406                 cat_blob_fd = xdup(helper->in);
 407                 argv_array_pushf(&fastimport->args, "--cat-blob-fd=%d", cat_blob_fd);
 408         }
 409         fastimport->git_cmd = 1;
 410
 411         code = start_command(fastimport);
 412         return code;
 413 }
 414
 415 static int get_exporter(struct transport *transport,
 416                         struct child_process *fastexport,
 417                         struct string_list *revlist_args)
 418 {
 419         struct helper_data *data = transport->data;
 420         struct child_process *helper = get_helper(transport);
 421         int i;
 422
 423         memset(fastexport, 0, sizeof(*fastexport));
 424
 425         /* we need to duplicate helper->in because we want to use it after
 426          * fastexport is done with it. */
 427         fastexport->out = dup(helper->in);
 428         argv_array_push(&fastexport->args, "fast-export");
 429         argv_array_push(&fastexport->args, "--use-done-feature");
 430         argv_array_push(&fastexport->args, data->signed_tags ?
 431                 "--signed-tags=verbatim" : "--signed-tags=warn-strip");
 432         if (data->export_marks)
 433                 argv_array_pushf(&fastexport->args, "--export-marks=%s.tmp", data->export_marks);
 434         if (data->import_marks)
 435                 argv_array_pushf(&fastexport->args, "--import-marks=%s", data->import_marks);
 436
 437         for (i = 0; i < revlist_args->nr; i++)
 438                 argv_array_push(&fastexport->args, revlist_args->items[i].string);
 439
 440         fastexport->git_cmd = 1;
 441         return start_command(fastexport);
 442 }
 443
 444 static int fetch_with_import(struct transport *transport,
 445                              int nr_heads, struct ref **to_fetch)
 446 {
 447         struct child_process fastimport;
 448         struct helper_data *data = transport->data;
 449         int i;
 450         struct ref *posn;
 451         struct strbuf buf = STRBUF_INIT;
 452
 453         get_helper(transport);
 454
 455         if (get_importer(transport, &fastimport))
 456                 die("Couldn't run fast-import");
 457
 458         for (i = 0; i < nr_heads; i++) {
 459                 posn = to_fetch[i];
 460                 if (posn->status & REF_STATUS_UPTODATE)
 461                         continue;
 462
 463                 strbuf_addf(&buf, "import %s\n", posn->name);
 464                 sendline(data, &buf);
 465                 strbuf_reset(&buf);
 466         }
 467
 468         write_constant(data->helper->in, "\n");
 469         /*
 470          * remote-helpers that advertise the bidi-import capability are required to
 471          * buffer the complete batch of import commands until this newline before
 472          * sending data to fast-import.
 473          * These helpers read back data from fast-import on their stdin, which could
 474          * be mixed with import commands, otherwise.
 475          */
 476
 477         if (finish_command(&fastimport))
 478                 die("Error while running fast-import");
 479
 480         /*
 481          * The fast-import stream of a remote helper that advertises
 482          * the "refspec" capability writes to the refs named after the
 483          * right hand side of the first refspec matching each ref we
 484          * were fetching.
 485          *
 486          * (If no "refspec" capability was specified, for historical
 487          * reasons we default to the equivalent of *:*.)
 488          *
 489          * Store the result in to_fetch[i].old_sha1.  Callers such
 490          * as "git fetch" can use the value to write feedback to the
 491          * terminal, populate FETCH_HEAD, and determine what new value
 492          * should be written to peer_ref if the update is a
 493          * fast-forward or this is a forced update.
 494          */
 495         for (i = 0; i < nr_heads; i++) {
 496                 char *private;
 497                 posn = to_fetch[i];
 498                 if (posn->status & REF_STATUS_UPTODATE)
 499                         continue;
 500                 if (data->refspecs)
 501                         private = apply_refspecs(data->refspecs, data->refspec_nr, posn->name);
 502                 else
 503                         private = xstrdup(posn->name);
 504                 if (private) {
 505                         read_ref(private, posn->old_sha1);
 506                         free(private);
 507                 }
 508         }
 509         strbuf_release(&buf);
 510         return 0;
 511 }
 512
 513 static int process_connect_service(struct transport *transport,
 514                                    const char *name, const char *exec)
 515 {
 516         struct helper_data *data = transport->data;
 517         struct strbuf cmdbuf = STRBUF_INIT;
 518         struct child_process *helper;
 519         int r, duped, ret = 0;
 520         FILE *input;
 521
 522         helper = get_helper(transport);
 523
 524         /*
 525          * Yes, dup the pipe another time, as we need unbuffered version
 526          * of input pipe as FILE*. fclose() closes the underlying fd and
 527          * stream buffering only can be changed before first I/O operation
 528          * on it.
 529          */
 530         duped = dup(helper->out);
 531         if (duped < 0)
 532                 die_errno("Can't dup helper output fd");
 533         input = xfdopen(duped, "r");
 534         setvbuf(input, NULL, _IONBF, 0);
 535
 536         /*
 537          * Handle --upload-pack and friends. This is fire and forget...
 538          * just warn if it fails.
 539          */
 540         if (strcmp(name, exec)) {
 541                 r = set_helper_option(transport, "servpath", exec);
 542                 if (r > 0)
 543                         warning("Setting remote service path not supported by protocol.");
 544                 else if (r < 0)
 545                         warning("Invalid remote service path.");
 546         }
 547
 548         if (data->connect)
 549                 strbuf_addf(&cmdbuf, "connect %s\n", name);
 550         else
 551                 goto exit;
 552
 553         sendline(data, &cmdbuf);
 554         if (recvline_fh(input, &cmdbuf, name))
 555                 exit(128);
 556
 557         if (!strcmp(cmdbuf.buf, "")) {
 558                 data->no_disconnect_req = 1;
 559                 if (debug)
 560                         fprintf(stderr, "Debug: Smart transport connection "
 561                                 "ready.\n");
 562                 ret = 1;
 563         } else if (!strcmp(cmdbuf.buf, "fallback")) {
 564                 if (debug)
 565                         fprintf(stderr, "Debug: Falling back to dumb "
 566                                 "transport.\n");
 567         } else
 568                 die("Unknown response to connect: %s",
 569                         cmdbuf.buf);
 570
 571 exit:
 572         fclose(input);
 573         return ret;
 574 }
 575
 576 static int process_connect(struct transport *transport,
 577                                      int for_push)
 578 {
 579         struct helper_data *data = transport->data;
 580         const char *name;
 581         const char *exec;
 582
 583         name = for_push ? "git-receive-pack" : "git-upload-pack";
 584         if (for_push)
 585                 exec = data->transport_options.receivepack;
 586         else
 587                 exec = data->transport_options.uploadpack;
 588
 589         return process_connect_service(transport, name, exec);
 590 }
 591
 592 static int connect_helper(struct transport *transport, const char *name,
 593                    const char *exec, int fd[2])
 594 {
 595         struct helper_data *data = transport->data;
 596
 597         /* Get_helper so connect is inited. */
 598         get_helper(transport);
 599         if (!data->connect)
 600                 die("Operation not supported by protocol.");
 601
 602         if (!process_connect_service(transport, name, exec))
 603                 die("Can't connect to subservice %s.", name);
 604
 605         fd[0] = data->helper->out;
 606         fd[1] = data->helper->in;
 607         return 0;
 608 }
 609
 610 static int fetch(struct transport *transport,
 611                  int nr_heads, struct ref **to_fetch)
 612 {
 613         struct helper_data *data = transport->data;
 614         int i, count;
 615
 616         if (process_connect(transport, 0)) {
 617                 do_take_over(transport);
 618                 return transport->fetch(transport, nr_heads, to_fetch);
 619         }
 620
 621         count = 0;
 622         for (i = 0; i < nr_heads; i++)
 623                 if (!(to_fetch[i]->status & REF_STATUS_UPTODATE))
 624                         count++;
 625
 626         if (!count)
 627                 return 0;
 628
 629         if (data->fetch)
 630                 return fetch_with_fetch(transport, nr_heads, to_fetch);
 631
 632         if (data->import)
 633                 return fetch_with_import(transport, nr_heads, to_fetch);
 634
 635         return -1;
 636 }
 637
 638 static int push_update_ref_status(struct strbuf *buf,
 639                                    struct ref **ref,
 640                                    struct ref *remote_refs)
 641 {
 642         char *refname, *msg;
 643         int status, forced = 0;
 644
 645         if (starts_with(buf->buf, "ok ")) {
 646                 status = REF_STATUS_OK;
 647                 refname = buf->buf + 3;
 648         } else if (starts_with(buf->buf, "error ")) {
 649                 status = REF_STATUS_REMOTE_REJECT;
 650                 refname = buf->buf + 6;
 651         } else
 652                 die("expected ok/error, helper said '%s'", buf->buf);
 653
 654         msg = strchr(refname, ' ');
 655         if (msg) {
 656                 struct strbuf msg_buf = STRBUF_INIT;
 657                 const char *end;
 658
 659                 *msg++ = '\0';
 660                 if (!unquote_c_style(&msg_buf, msg, &end))
 661                         msg = strbuf_detach(&msg_buf, NULL);
 662                 else
 663                         msg = xstrdup(msg);
 664                 strbuf_release(&msg_buf);
 665
 666                 if (!strcmp(msg, "no match")) {
 667                         status = REF_STATUS_NONE;
 668                         free(msg);
 669                         msg = NULL;
 670                 }
 671                 else if (!strcmp(msg, "up to date")) {
 672                         status = REF_STATUS_UPTODATE;
 673                         free(msg);
 674                         msg = NULL;
 675                 }
 676                 else if (!strcmp(msg, "non-fast forward")) {
 677                         status = REF_STATUS_REJECT_NONFASTFORWARD;
 678                         free(msg);
 679                         msg = NULL;
 680                 }
 681                 else if (!strcmp(msg, "already exists")) {
 682                         status = REF_STATUS_REJECT_ALREADY_EXISTS;
 683                         free(msg);
 684                         msg = NULL;
 685                 }
 686                 else if (!strcmp(msg, "fetch first")) {
 687                         status = REF_STATUS_REJECT_FETCH_FIRST;
 688                         free(msg);
 689                         msg = NULL;
 690                 }
 691                 else if (!strcmp(msg, "needs force")) {
 692                         status = REF_STATUS_REJECT_NEEDS_FORCE;
 693                         free(msg);
 694                         msg = NULL;
 695                 }
 696                 else if (!strcmp(msg, "stale info")) {
 697                         status = REF_STATUS_REJECT_STALE;
 698                         free(msg);
 699                         msg = NULL;
 700                 }
 701                 else if (!strcmp(msg, "forced update")) {
 702                         forced = 1;
 703                         free(msg);
 704                         msg = NULL;
 705                 }
 706         }
 707
 708         if (*ref)
 709                 *ref = find_ref_by_name(*ref, refname);
 710         if (!*ref)
 711                 *ref = find_ref_by_name(remote_refs, refname);
 712         if (!*ref) {
 713                 warning("helper reported unexpected status of %s", refname);
 714                 return 1;
 715         }
 716
 717         if ((*ref)->status != REF_STATUS_NONE) {
 718                 /*
 719                  * Earlier, the ref was marked not to be pushed, so ignore the ref
 720                  * status reported by the remote helper if the latter is 'no match'.
 721                  */
 722                 if (status == REF_STATUS_NONE)
 723                         return 1;
 724         }
 725
 726         (*ref)->status = status;
 727         (*ref)->forced_update |= forced;
 728         (*ref)->remote_status = msg;
 729         return !(status == REF_STATUS_OK);
 730 }
 731
 732 static int push_update_refs_status(struct helper_data *data,
 733                                     struct ref *remote_refs,
 734                                     int flags)
 735 {
 736         struct strbuf buf = STRBUF_INIT;
 737         struct ref *ref = remote_refs;
 738         int ret = 0;
 739
 740         for (;;) {
 741                 char *private;
 742
 743                 if (recvline(data, &buf)) {
 744                         ret = 1;
 745                         break;
 746                 }
 747
 748                 if (!buf.len)
 749                         break;
 750
 751                 if (push_update_ref_status(&buf, &ref, remote_refs))
 752                         continue;
 753
 754                 if (flags & TRANSPORT_PUSH_DRY_RUN || !data->refspecs || data->no_private_update)
 755                         continue;
 756
 757                 /* propagate back the update to the remote namespace */
 758                 private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
 759                 if (!private)
 760                         continue;
 761                 update_ref("update by helper", private, ref->new_sha1, NULL, 0, 0);
 762                 free(private);
 763         }
 764         strbuf_release(&buf);
 765         return ret;
 766 }
 767
 768 static int push_refs_with_push(struct transport *transport,
 769                                struct ref *remote_refs, int flags)
 770 {
 771         int force_all = flags & TRANSPORT_PUSH_FORCE;
 772         int mirror = flags & TRANSPORT_PUSH_MIRROR;
 773         struct helper_data *data = transport->data;
 774         struct strbuf buf = STRBUF_INIT;
 775         struct ref *ref;
 776         struct string_list cas_options = STRING_LIST_INIT_DUP;
 777         struct string_list_item *cas_option;
 778
 779         get_helper(transport);
 780         if (!data->push)
 781                 return 1;
 782
 783         for (ref = remote_refs; ref; ref = ref->next) {
 784                 if (!ref->peer_ref && !mirror)
 785                         continue;
 786
 787                 /* Check for statuses set by set_ref_status_for_push() */
 788                 switch (ref->status) {
 789                 case REF_STATUS_REJECT_NONFASTFORWARD:
 790                 case REF_STATUS_REJECT_STALE:
 791                 case REF_STATUS_REJECT_ALREADY_EXISTS:
 792                 case REF_STATUS_UPTODATE:
 793                         continue;
 794                 default:
 795                         ; /* do nothing */
 796                 }
 797
 798                 if (force_all)
 799                         ref->force = 1;
 800
 801                 strbuf_addstr(&buf, "push ");
 802                 if (!ref->deletion) {
 803                         if (ref->force)
 804                                 strbuf_addch(&buf, '+');
 805                         if (ref->peer_ref)
 806                                 strbuf_addstr(&buf, ref->peer_ref->name);
 807                         else
 808                                 strbuf_addstr(&buf, sha1_to_hex(ref->new_sha1));
 809                 }
 810                 strbuf_addch(&buf, ':');
 811                 strbuf_addstr(&buf, ref->name);
 812                 strbuf_addch(&buf, '\n');
 813
 814                 /*
 815                  * The "--force-with-lease" options without explicit
 816                  * values to expect have already been expanded into
 817                  * the ref->old_sha1_expect[] field; we can ignore
 818                  * transport->smart_options->cas altogether and instead
 819                  * can enumerate them from the refs.
 820                  */
 821                 if (ref->expect_old_sha1) {
 822                         struct strbuf cas = STRBUF_INIT;
 823                         strbuf_addf(&cas, "%s:%s",
 824                                     ref->name, sha1_to_hex(ref->old_sha1_expect));
 825                         string_list_append(&cas_options, strbuf_detach(&cas, NULL));
 826                 }
 827         }
 828         if (buf.len == 0) {
 829                 string_list_clear(&cas_options, 0);
 830                 return 0;
 831         }
 832
 833         standard_options(transport);
 834         for_each_string_list_item(cas_option, &cas_options)
 835                 set_helper_option(transport, "cas", cas_option->string);
 836
 837         if (flags & TRANSPORT_PUSH_DRY_RUN) {
 838                 if (set_helper_option(transport, "dry-run", "true") != 0)
 839                         die("helper %s does not support dry-run", data->name);
 840         } else if (flags & TRANSPORT_PUSH_CERT) {
 841                 if (set_helper_option(transport, TRANS_OPT_PUSH_CERT, "true") != 0)
 842                         die("helper %s does not support --signed", data->name);
 843         }
 844
 845         strbuf_addch(&buf, '\n');
 846         sendline(data, &buf);
 847         strbuf_release(&buf);
 848
 849         return push_update_refs_status(data, remote_refs, flags);
 850 }
 851
 852 static int push_refs_with_export(struct transport *transport,
 853                 struct ref *remote_refs, int flags)
 854 {
 855         struct ref *ref;
 856         struct child_process *helper, exporter;
 857         struct helper_data *data = transport->data;
 858         struct string_list revlist_args = STRING_LIST_INIT_DUP;
 859         struct strbuf buf = STRBUF_INIT;
 860
 861         if (!data->refspecs)
 862                 die("remote-helper doesn't support push; refspec needed");
 863
 864         if (flags & TRANSPORT_PUSH_DRY_RUN) {
 865                 if (set_helper_option(transport, "dry-run", "true") != 0)
 866                         die("helper %s does not support dry-run", data->name);
 867         } else if (flags & TRANSPORT_PUSH_CERT) {
 868                 if (set_helper_option(transport, TRANS_OPT_PUSH_CERT, "true") != 0)
 869                         die("helper %s does not support dry-run", data->name);
 870         }
 871
 872         if (flags & TRANSPORT_PUSH_FORCE) {
 873                 if (set_helper_option(transport, "force", "true") != 0)
 874                         warning("helper %s does not support 'force'", data->name);
 875         }
 876
 877         helper = get_helper(transport);
 878
 879         write_constant(helper->in, "export\n");
 880
 881         for (ref = remote_refs; ref; ref = ref->next) {
 882                 char *private;
 883                 unsigned char sha1[20];
 884
 885                 private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
 886                 if (private && !get_sha1(private, sha1)) {
 887                         strbuf_addf(&buf, "^%s", private);
 888                         string_list_append(&revlist_args, strbuf_detach(&buf, NULL));
 889                         hashcpy(ref->old_sha1, sha1);
 890                 }
 891                 free(private);
 892
 893                 if (ref->peer_ref) {
 894                         if (strcmp(ref->name, ref->peer_ref->name)) {
 895                                 if (!ref->deletion) {
 896                                         const char *name;
 897                                         int flag;
 898
 899                                         /* Follow symbolic refs (mainly for HEAD). */
 900                                         name = resolve_ref_unsafe(ref->peer_ref->name, sha1, 1, &flag);
 901                                         if (!name || !(flag & REF_ISSYMREF))
 902                                                 name = ref->peer_ref->name;
 903
 904                                         strbuf_addf(&buf, "%s:%s", name, ref->name);
 905                                 } else
 906                                         strbuf_addf(&buf, ":%s", ref->name);
 907
 908                                 string_list_append(&revlist_args, "--refspec");
 909                                 string_list_append(&revlist_args, buf.buf);
 910                                 strbuf_release(&buf);
 911                         }
 912                         if (!ref->deletion)
 913                                 string_list_append(&revlist_args, ref->peer_ref->name);
 914                 }
 915         }
 916
 917         if (get_exporter(transport, &exporter, &revlist_args))
 918                 die("Couldn't run fast-export");
 919
 920         string_list_clear(&revlist_args, 1);
 921
 922         if (finish_command(&exporter))
 923                 die("Error while running fast-export");
 924         if (push_update_refs_status(data, remote_refs, flags))
 925                 return 1;
 926
 927         if (data->export_marks) {
 928                 strbuf_addf(&buf, "%s.tmp", data->export_marks);
 929                 rename(buf.buf, data->export_marks);
 930                 strbuf_release(&buf);
 931         }
 932
 933         return 0;
 934 }
 935
 936 static int push_refs(struct transport *transport,
 937                 struct ref *remote_refs, int flags)
 938 {
 939         struct helper_data *data = transport->data;
 940
 941         if (process_connect(transport, 1)) {
 942                 do_take_over(transport);
 943                 return transport->push_refs(transport, remote_refs, flags);
 944         }
 945
 946         if (!remote_refs) {
 947                 fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
 948                         "Perhaps you should specify a branch such as 'master'.\n");
 949                 return 0;
 950         }
 951
 952         if (data->push)
 953                 return push_refs_with_push(transport, remote_refs, flags);
 954
 955         if (data->export)
 956                 return push_refs_with_export(transport, remote_refs, flags);
 957
 958         return -1;
 959 }
 960
 961
 962 static int has_attribute(const char *attrs, const char *attr) {
 963         int len;
 964         if (!attrs)
 965                 return 0;
 966
 967         len = strlen(attr);
 968         for (;;) {
 969                 const char *space = strchrnul(attrs, ' ');
 970                 if (len == space - attrs && !strncmp(attrs, attr, len))
 971                         return 1;
 972                 if (!*space)
 973                         return 0;
 974                 attrs = space + 1;
 975         }
 976 }
 977
 978 static struct ref *get_refs_list(struct transport *transport, int for_push)
 979 {
 980         struct helper_data *data = transport->data;
 981         struct child_process *helper;
 982         struct ref *ret = NULL;
 983         struct ref **tail = &ret;
 984         struct ref *posn;
 985         struct strbuf buf = STRBUF_INIT;
 986
 987         helper = get_helper(transport);
 988
 989         if (process_connect(transport, for_push)) {
 990                 do_take_over(transport);
 991                 return transport->get_refs_list(transport, for_push);
 992         }
 993
 994         if (data->push && for_push)
 995                 write_str_in_full(helper->in, "list for-push\n");
 996         else
 997                 write_str_in_full(helper->in, "list\n");
 998
 999         while (1) {
1000                 char *eov, *eon;
1001                 if (recvline(data, &buf))
1002                         exit(128);
1003
1004                 if (!*buf.buf)
1005                         break;
1006
1007                 eov = strchr(buf.buf, ' ');
1008                 if (!eov)
1009                         die("Malformed response in ref list: %s", buf.buf);
1010                 eon = strchr(eov + 1, ' ');
1011                 *eov = '\0';
1012                 if (eon)
1013                         *eon = '\0';
1014                 *tail = alloc_ref(eov + 1);
1015                 if (buf.buf[0] == '@')
1016                         (*tail)->symref = xstrdup(buf.buf + 1);
1017                 else if (buf.buf[0] != '?')
1018                         get_sha1_hex(buf.buf, (*tail)->old_sha1);
1019                 if (eon) {
1020                         if (has_attribute(eon + 1, "unchanged")) {
1021                                 (*tail)->status |= REF_STATUS_UPTODATE;
1022                                 read_ref((*tail)->name, (*tail)->old_sha1);
1023                         }
1024                 }
1025                 tail = &((*tail)->next);
1026         }
1027         if (debug)
1028                 fprintf(stderr, "Debug: Read ref listing.\n");
1029         strbuf_release(&buf);
1030
1031         for (posn = ret; posn; posn = posn->next)
1032                 resolve_remote_symref(posn, ret);
1033
1034         return ret;
1035 }
1036
1037 int transport_helper_init(struct transport *transport, const char *name)
1038 {
1039         struct helper_data *data = xcalloc(1, sizeof(*data));
1040         data->name = name;
1041
1042         if (getenv("GIT_TRANSPORT_HELPER_DEBUG"))
1043                 debug = 1;
1044
1045         transport->data = data;
1046         transport->set_option = set_helper_option;
1047         transport->get_refs_list = get_refs_list;
1048         transport->fetch = fetch;
1049         transport->push_refs = push_refs;
1050         transport->disconnect = release_helper;
1051         transport->connect = connect_helper;
1052         transport->smart_options = &(data->transport_options);
1053         return 0;
1054 }
1055
1056 /*
1057  * Linux pipes can buffer 65536 bytes at once (and most platforms can
1058  * buffer less), so attempt reads and writes with up to that size.
1059  */
1060 #define BUFFERSIZE 65536
1061 /* This should be enough to hold debugging message. */
1062 #define PBUFFERSIZE 8192
1063
1064 /* Print bidirectional transfer loop debug message. */
1065 __attribute__((format (printf, 1, 2)))
1066 static void transfer_debug(const char *fmt, ...)
1067 {
1068         va_list args;
1069         char msgbuf[PBUFFERSIZE];
1070         static int debug_enabled = -1;
1071
1072         if (debug_enabled < 0)
1073                 debug_enabled = getenv("GIT_TRANSLOOP_DEBUG") ? 1 : 0;
1074         if (!debug_enabled)
1075                 return;
1076
1077         va_start(args, fmt);
1078         vsnprintf(msgbuf, PBUFFERSIZE, fmt, args);
1079         va_end(args);
1080         fprintf(stderr, "Transfer loop debugging: %s\n", msgbuf);
1081 }
1082
1083 /* Stream state: More data may be coming in this direction. */
1084 #define SSTATE_TRANSFERING 0
1085 /*
1086  * Stream state: No more data coming in this direction, flushing rest of
1087  * data.
1088  */
1089 #define SSTATE_FLUSHING 1
1090 /* Stream state: Transfer in this direction finished. */
1091 #define SSTATE_FINISHED 2
1092
1093 #define STATE_NEEDS_READING(state) ((state) <= SSTATE_TRANSFERING)
1094 #define STATE_NEEDS_WRITING(state) ((state) <= SSTATE_FLUSHING)
1095 #define STATE_NEEDS_CLOSING(state) ((state) == SSTATE_FLUSHING)
1096
1097 /* Unidirectional transfer. */
1098 struct unidirectional_transfer {
1099         /* Source */
1100         int src;
1101         /* Destination */
1102         int dest;
1103         /* Is source socket? */
1104         int src_is_sock;
1105         /* Is destination socket? */
1106         int dest_is_sock;
1107         /* Transfer state (TRANSFERRING/FLUSHING/FINISHED) */
1108         int state;
1109         /* Buffer. */
1110         char buf[BUFFERSIZE];
1111         /* Buffer used. */
1112         size_t bufuse;
1113         /* Name of source. */
1114         const char *src_name;
1115         /* Name of destination. */
1116         const char *dest_name;
1117 };
1118
1119 /* Closes the target (for writing) if transfer has finished. */
1120 static void udt_close_if_finished(struct unidirectional_transfer *t)
1121 {
1122         if (STATE_NEEDS_CLOSING(t->state) && !t->bufuse) {
1123                 t->state = SSTATE_FINISHED;
1124                 if (t->dest_is_sock)
1125                         shutdown(t->dest, SHUT_WR);
1126                 else
1127                         close(t->dest);
1128                 transfer_debug("Closed %s.", t->dest_name);
1129         }
1130 }
1131
1132 /*
1133  * Tries to read read data from source into buffer. If buffer is full,
1134  * no data is read. Returns 0 on success, -1 on error.
1135  */
1136 static int udt_do_read(struct unidirectional_transfer *t)
1137 {
1138         ssize_t bytes;
1139
1140         if (t->bufuse == BUFFERSIZE)
1141                 return 0;       /* No space for more. */
1142
1143         transfer_debug("%s is readable", t->src_name);
1144         bytes = read(t->src, t->buf + t->bufuse, BUFFERSIZE - t->bufuse);
1145         if (bytes < 0 && errno != EWOULDBLOCK && errno != EAGAIN &&
1146                 errno != EINTR) {
1147                 error("read(%s) failed: %s", t->src_name, strerror(errno));
1148                 return -1;
1149         } else if (bytes == 0) {
1150                 transfer_debug("%s EOF (with %i bytes in buffer)",
1151                         t->src_name, (int)t->bufuse);
1152                 t->state = SSTATE_FLUSHING;
1153         } else if (bytes > 0) {
1154                 t->bufuse += bytes;
1155                 transfer_debug("Read %i bytes from %s (buffer now at %i)",
1156                         (int)bytes, t->src_name, (int)t->bufuse);
1157         }
1158         return 0;
1159 }
1160
1161 /* Tries to write data from buffer into destination. If buffer is empty,
1162  * no data is written. Returns 0 on success, -1 on error.
1163  */
1164 static int udt_do_write(struct unidirectional_transfer *t)
1165 {
1166         ssize_t bytes;
1167
1168         if (t->bufuse == 0)
1169                 return 0;       /* Nothing to write. */
1170
1171         transfer_debug("%s is writable", t->dest_name);
1172         bytes = xwrite(t->dest, t->buf, t->bufuse);
1173         if (bytes < 0 && errno != EWOULDBLOCK) {
1174                 error("write(%s) failed: %s", t->dest_name, strerror(errno));
1175                 return -1;
1176         } else if (bytes > 0) {
1177                 t->bufuse -= bytes;
1178                 if (t->bufuse)
1179                         memmove(t->buf, t->buf + bytes, t->bufuse);
1180                 transfer_debug("Wrote %i bytes to %s (buffer now at %i)",
1181                         (int)bytes, t->dest_name, (int)t->bufuse);
1182         }
1183         return 0;
1184 }
1185
1186
1187 /* State of bidirectional transfer loop. */
1188 struct bidirectional_transfer_state {
1189         /* Direction from program to git. */
1190         struct unidirectional_transfer ptg;
1191         /* Direction from git to program. */
1192         struct unidirectional_transfer gtp;
1193 };
1194
1195 static void *udt_copy_task_routine(void *udt)
1196 {
1197         struct unidirectional_transfer *t = (struct unidirectional_transfer *)udt;
1198         while (t->state != SSTATE_FINISHED) {
1199                 if (STATE_NEEDS_READING(t->state))
1200                         if (udt_do_read(t))
1201                                 return NULL;
1202                 if (STATE_NEEDS_WRITING(t->state))
1203                         if (udt_do_write(t))
1204                                 return NULL;
1205                 if (STATE_NEEDS_CLOSING(t->state))
1206                         udt_close_if_finished(t);
1207         }
1208         return udt;     /* Just some non-NULL value. */
1209 }
1210
1211 #ifndef NO_PTHREADS
1212
1213 /*
1214  * Join thread, with appropriate errors on failure. Name is name for the
1215  * thread (for error messages). Returns 0 on success, 1 on failure.
1216  */
1217 static int tloop_join(pthread_t thread, const char *name)
1218 {
1219         int err;
1220         void *tret;
1221         err = pthread_join(thread, &tret);
1222         if (!tret) {
1223                 error("%s thread failed", name);
1224                 return 1;
1225         }
1226         if (err) {
1227                 error("%s thread failed to join: %s", name, strerror(err));
1228                 return 1;
1229         }
1230         return 0;
1231 }
1232
1233 /*
1234  * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1235  * -1 on failure.
1236  */
1237 static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1238 {
1239         pthread_t gtp_thread;
1240         pthread_t ptg_thread;
1241         int err;
1242         int ret = 0;
1243         err = pthread_create(&gtp_thread, NULL, udt_copy_task_routine,
1244                 &s->gtp);
1245         if (err)
1246                 die("Can't start thread for copying data: %s", strerror(err));
1247         err = pthread_create(&ptg_thread, NULL, udt_copy_task_routine,
1248                 &s->ptg);
1249         if (err)
1250                 die("Can't start thread for copying data: %s", strerror(err));
1251
1252         ret |= tloop_join(gtp_thread, "Git to program copy");
1253         ret |= tloop_join(ptg_thread, "Program to git copy");
1254         return ret;
1255 }
1256 #else
1257
1258 /* Close the source and target (for writing) for transfer. */
1259 static void udt_kill_transfer(struct unidirectional_transfer *t)
1260 {
1261         t->state = SSTATE_FINISHED;
1262         /*
1263          * Socket read end left open isn't a disaster if nobody
1264          * attempts to read from it (mingw compat headers do not
1265          * have SHUT_RD)...
1266          *
1267          * We can't fully close the socket since otherwise gtp
1268          * task would first close the socket it sends data to
1269          * while closing the ptg file descriptors.
1270          */
1271         if (!t->src_is_sock)
1272                 close(t->src);
1273         if (t->dest_is_sock)
1274                 shutdown(t->dest, SHUT_WR);
1275         else
1276                 close(t->dest);
1277 }
1278
1279 /*
1280  * Join process, with appropriate errors on failure. Name is name for the
1281  * process (for error messages). Returns 0 on success, 1 on failure.
1282  */
1283 static int tloop_join(pid_t pid, const char *name)
1284 {
1285         int tret;
1286         if (waitpid(pid, &tret, 0) < 0) {
1287                 error("%s process failed to wait: %s", name, strerror(errno));
1288                 return 1;
1289         }
1290         if (!WIFEXITED(tret) || WEXITSTATUS(tret)) {
1291                 error("%s process failed", name);
1292                 return 1;
1293         }
1294         return 0;
1295 }
1296
1297 /*
1298  * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1299  * -1 on failure.
1300  */
1301 static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1302 {
1303         pid_t pid1, pid2;
1304         int ret = 0;
1305
1306         /* Fork thread #1: git to program. */
1307         pid1 = fork();
1308         if (pid1 < 0)
1309                 die_errno("Can't start thread for copying data");
1310         else if (pid1 == 0) {
1311                 udt_kill_transfer(&s->ptg);
1312                 exit(udt_copy_task_routine(&s->gtp) ? 0 : 1);
1313         }
1314
1315         /* Fork thread #2: program to git. */
1316         pid2 = fork();
1317         if (pid2 < 0)
1318                 die_errno("Can't start thread for copying data");
1319         else if (pid2 == 0) {
1320                 udt_kill_transfer(&s->gtp);
1321                 exit(udt_copy_task_routine(&s->ptg) ? 0 : 1);
1322         }
1323
1324         /*
1325          * Close both streams in parent as to not interfere with
1326          * end of file detection and wait for both tasks to finish.
1327          */
1328         udt_kill_transfer(&s->gtp);
1329         udt_kill_transfer(&s->ptg);
1330         ret |= tloop_join(pid1, "Git to program copy");
1331         ret |= tloop_join(pid2, "Program to git copy");
1332         return ret;
1333 }
1334 #endif
1335
1336 /*
1337  * Copies data from stdin to output and from input to stdout simultaneously.
1338  * Additionally filtering through given filter. If filter is NULL, uses
1339  * identity filter.
1340  */
1341 int bidirectional_transfer_loop(int input, int output)
1342 {
1343         struct bidirectional_transfer_state state;
1344
1345         /* Fill the state fields. */
1346         state.ptg.src = input;
1347         state.ptg.dest = 1;
1348         state.ptg.src_is_sock = (input == output);
1349         state.ptg.dest_is_sock = 0;
1350         state.ptg.state = SSTATE_TRANSFERING;
1351         state.ptg.bufuse = 0;
1352         state.ptg.src_name = "remote input";
1353         state.ptg.dest_name = "stdout";
1354
1355         state.gtp.src = 0;
1356         state.gtp.dest = output;
1357         state.gtp.src_is_sock = 0;
1358         state.gtp.dest_is_sock = (input == output);
1359         state.gtp.state = SSTATE_TRANSFERING;
1360         state.gtp.bufuse = 0;
1361         state.gtp.src_name = "stdin";
1362         state.gtp.dest_name = "remote output";
1363
1364         return tloop_spawnwait_tasks(&state);
1365 }