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