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

   1 #include "cache.h"
   2 #include "transport.h"
   3 #include "quote.h"
   4 #include "run-command.h"
   5 #include "commit.h"
   6 #include "diff.h"
   7 #include "revision.h"
   8 #include "remote.h"
   9 #include "string-list.h"
  10 #include "thread-utils.h"
  11 #include "sigchain.h"
  12 #include "argv-array.h"
  13 #include "refs.h"
  14
  15 static int debug;
  16
  17 struct helper_data {
  18         const char *name;
  19         struct child_process *helper;
  20         FILE *out;
  21         unsigned fetch : 1,
  22                 import : 1,
  23                 bidi_import : 1,
  24                 export : 1,
  25                 option : 1,
  26                 push : 1,
  27                 connect : 1,
  28                 signed_tags : 1,
  29                 check_connectivity : 1,
  30                 no_disconnect_req : 1,
  31                 no_private_update : 1;
  32         char *export_marks;
  33         char *import_marks;
  34         /* These go from remote name (as in "list") to private name */
  35         struct refspec *refspecs;
  36         int refspec_nr;
  37         /* Transport options for fetch-pack/send-pack (should one of
  38          * those be invoked).
  39          */
  40         struct git_transport_options transport_options;
  41 };
  42
  43 static void sendline(struct helper_data *helper, struct strbuf *buffer)
  44 {
  45         if (debug)
  46                 fprintf(stderr, "Debug: Remote helper: -> %s", buffer->buf);
  47         if (write_in_full(helper->helper->in, buffer->buf, buffer->len)
  48                 != buffer->len)
  49                 die_errno("Full write to remote helper failed");
  50 }
  51
  52 static int recvline_fh(FILE *helper, struct strbuf *buffer, const char *name)
  53 {
  54         strbuf_reset(buffer);
  55         if (debug)
  56                 fprintf(stderr, "Debug: Remote helper: Waiting...\n");
  57         if (strbuf_getline(buffer, helper, '\n') == EOF) {
  58                 if (debug)
  59                         fprintf(stderr, "Debug: Remote helper quit.\n");
  60                 return 1;
  61         }
  62
  63         if (debug)
  64                 fprintf(stderr, "Debug: Remote helper: <- %s\n", buffer->buf);
  65         return 0;
  66 }
  67
  68 static int recvline(struct helper_data *helper, struct strbuf *buffer)
  69 {
  70         return recvline_fh(helper->out, buffer, helper->name);
  71 }
  72
  73 static void write_constant(int fd, const char *str)
  74 {
  75         if (debug)
  76                 fprintf(stderr, "Debug: Remote helper: -> %s", str);
  77         if (write_in_full(fd, str, strlen(str)) != strlen(str))
  78                 die_errno("Full write to remote helper failed");
  79 }
  80
  81 static const char *remove_ext_force(const char *url)
  82 {
  83         if (url) {
  84                 const char *colon = strchr(url, ':');
  85                 if (colon && colon[1] == ':')
  86                         return colon + 2;
  87         }
  88         return url;
  89 }
  90
  91 static void do_take_over(struct transport *transport)
  92 {
  93         struct helper_data *data;
  94         data = (struct helper_data *)transport->data;
  95         transport_take_over(transport, data->helper);
  96         fclose(data->out);
  97         free(data);
  98 }
  99
 100 static void standard_options(struct transport *t);
 101
 102 static struct child_process *get_helper(struct transport *transport)
 103 {
 104         struct helper_data *data = transport->data;
 105         struct strbuf buf = STRBUF_INIT;
 106         struct child_process *helper;
 107         const char **refspecs = NULL;
 108         int refspec_nr = 0;
 109         int refspec_alloc = 0;
 110         int duped;
 111         int code;
 112
 113         if (data->helper)
 114                 return data->helper;
 115
 116         helper = xmalloc(sizeof(*helper));
 117         child_process_init(helper);
 118         helper->in = -1;
 119         helper->out = -1;
 120         helper->err = 0;
 121         argv_array_pushf(&helper->args, "git-remote-%s", data->name);
 122         argv_array_push(&helper->args, transport->remote->name);
 123         argv_array_push(&helper->args, remove_ext_force(transport->url));
 124         helper->git_cmd = 0;
 125         helper->silent_exec_failure = 1;
 126
 127         argv_array_pushf(&helper->env_array, "%s=%s", GIT_DIR_ENVIRONMENT,
 128                          get_git_dir());
 129
 130         code = start_command(helper);
 131         if (code < 0 && errno == ENOENT)
 132                 die("Unable to find remote helper for '%s'", data->name);
 133         else if (code != 0)
 134                 exit(code);
 135
 136         data->helper = helper;
 137         data->no_disconnect_req = 0;
 138
 139         /*
 140          * Open the output as FILE* so strbuf_getline() can be used.
 141          * Do this with duped fd because fclose() will close the fd,
 142          * and stuff like taking over will require the fd to remain.
 143          */
 144         duped = dup(helper->out);
 145         if (duped < 0)
 146                 die_errno("Can't dup helper output fd");
 147         data->out = xfdopen(duped, "r");
 148
 149         write_constant(helper->in, "capabilities\n");
 150
 151         while (1) {
 152                 const char *capname, *arg;
 153                 int mandatory = 0;
 154                 if (recvline(data, &buf))
 155                         exit(128);
 156
 157                 if (!*buf.buf)
 158                         break;
 159
 160                 if (*buf.buf == '*') {
 161                         capname = buf.buf + 1;
 162                         mandatory = 1;
 163                 } else
 164                         capname = buf.buf;
 165
 166                 if (debug)
 167                         fprintf(stderr, "Debug: Got cap %s\n", capname);
 168                 if (!strcmp(capname, "fetch"))
 169                         data->fetch = 1;
 170                 else if (!strcmp(capname, "option"))
 171                         data->option = 1;
 172                 else if (!strcmp(capname, "push"))
 173                         data->push = 1;
 174                 else if (!strcmp(capname, "import"))
 175                         data->import = 1;
 176                 else if (!strcmp(capname, "bidi-import"))
 177                         data->bidi_import = 1;
 178                 else if (!strcmp(capname, "export"))
 179                         data->export = 1;
 180                 else if (!strcmp(capname, "check-connectivity"))
 181                         data->check_connectivity = 1;
 182                 else if (!data->refspecs && skip_prefix(capname, "refspec ", &arg)) {
 183                         ALLOC_GROW(refspecs,
 184                                    refspec_nr + 1,
 185                                    refspec_alloc);
 186                         refspecs[refspec_nr++] = xstrdup(arg);
 187                 } else if (!strcmp(capname, "connect")) {
 188                         data->connect = 1;
 189                 } else if (!strcmp(capname, "signed-tags")) {
 190                         data->signed_tags = 1;
 191                 } else if (skip_prefix(capname, "export-marks ", &arg)) {
 192                         data->export_marks = xstrdup(arg);
 193                 } else if (skip_prefix(capname, "import-marks ", &arg)) {
 194                         data->import_marks = xstrdup(arg);
 195                 } else if (starts_with(capname, "no-private-update")) {
 196                         data->no_private_update = 1;
 197                 } else if (mandatory) {
 198                         die("Unknown mandatory capability %s. This remote "
 199                             "helper probably needs newer version of Git.",
 200                             capname);
 201                 }
 202         }
 203         if (refspecs) {
 204                 int i;
 205                 data->refspec_nr = refspec_nr;
 206                 data->refspecs = parse_fetch_refspec(refspec_nr, refspecs);
 207                 for (i = 0; i < refspec_nr; i++)
 208                         free((char *)refspecs[i]);
 209                 free(refspecs);
 210         } else if (data->import || data->bidi_import || data->export) {
 211                 warning("This remote helper should implement refspec capability.");
 212         }
 213         strbuf_release(&buf);
 214         if (debug)
 215                 fprintf(stderr, "Debug: Capabilities complete.\n");
 216         standard_options(transport);
 217         return data->helper;
 218 }
 219
 220 static int disconnect_helper(struct transport *transport)
 221 {
 222         struct helper_data *data = transport->data;
 223         int res = 0;
 224
 225         if (data->helper) {
 226                 if (debug)
 227                         fprintf(stderr, "Debug: Disconnecting.\n");
 228                 if (!data->no_disconnect_req) {
 229                         /*
 230                          * Ignore write errors; there's nothing we can do,
 231                          * since we're about to close the pipe anyway. And the
 232                          * most likely error is EPIPE due to the helper dying
 233                          * to report an error itself.
 234                          */
 235                         sigchain_push(SIGPIPE, SIG_IGN);
 236                         xwrite(data->helper->in, "\n", 1);
 237                         sigchain_pop(SIGPIPE);
 238                 }
 239                 close(data->helper->in);
 240                 close(data->helper->out);
 241                 fclose(data->out);
 242                 res = finish_command(data->helper);
 243                 free(data->helper);
 244                 data->helper = NULL;
 245         }
 246         return res;
 247 }
 248
 249 static const char *unsupported_options[] = {
 250         TRANS_OPT_UPLOADPACK,
 251         TRANS_OPT_RECEIVEPACK,
 252         TRANS_OPT_THIN,
 253         TRANS_OPT_KEEP
 254         };
 255
 256 static const char *boolean_options[] = {
 257         TRANS_OPT_THIN,
 258         TRANS_OPT_KEEP,
 259         TRANS_OPT_FOLLOWTAGS,
 260         };
 261
 262 static int set_helper_option(struct transport *transport,
 263                           const char *name, const char *value)
 264 {
 265         struct helper_data *data = transport->data;
 266         struct strbuf buf = STRBUF_INIT;
 267         int i, ret, is_bool = 0;
 268
 269         get_helper(transport);
 270
 271         if (!data->option)
 272                 return 1;
 273
 274         for (i = 0; i < ARRAY_SIZE(unsupported_options); i++) {
 275                 if (!strcmp(name, unsupported_options[i]))
 276                         return 1;
 277         }
 278
 279         for (i = 0; i < ARRAY_SIZE(boolean_options); i++) {
 280                 if (!strcmp(name, boolean_options[i])) {
 281                         is_bool = 1;
 282                         break;
 283                 }
 284         }
 285
 286         strbuf_addf(&buf, "option %s ", name);
 287         if (is_bool)
 288                 strbuf_addstr(&buf, value ? "true" : "false");
 289         else
 290                 quote_c_style(value, &buf, NULL, 0);
 291         strbuf_addch(&buf, '\n');
 292
 293         sendline(data, &buf);
 294         if (recvline(data, &buf))
 295                 exit(128);
 296
 297         if (!strcmp(buf.buf, "ok"))
 298                 ret = 0;
 299         else if (starts_with(buf.buf, "error")) {
 300                 ret = -1;
 301         } else if (!strcmp(buf.buf, "unsupported"))
 302                 ret = 1;
 303         else {
 304                 warning("%s unexpectedly said: '%s'", data->name, buf.buf);
 305                 ret = 1;
 306         }
 307         strbuf_release(&buf);
 308         return ret;
 309 }
 310
 311 static void standard_options(struct transport *t)
 312 {
 313         char buf[16];
 314         int n;
 315         int v = t->verbose;
 316
 317         set_helper_option(t, "progress", t->progress ? "true" : "false");
 318
 319         n = snprintf(buf, sizeof(buf), "%d", v + 1);
 320         if (n >= sizeof(buf))
 321                 die("impossibly large verbosity value");
 322         set_helper_option(t, "verbosity", buf);
 323 }
 324
 325 static int release_helper(struct transport *transport)
 326 {
 327         int res = 0;
 328         struct helper_data *data = transport->data;
 329         free_refspec(data->refspec_nr, data->refspecs);
 330         data->refspecs = NULL;
 331         res = disconnect_helper(transport);
 332         free(transport->data);
 333         return res;
 334 }
 335
 336 static int fetch_with_fetch(struct transport *transport,
 337                             int nr_heads, struct ref **to_fetch)
 338 {
 339         struct helper_data *data = transport->data;
 340         int i;
 341         struct strbuf buf = STRBUF_INIT;
 342
 343         for (i = 0; i < nr_heads; i++) {
 344                 const struct ref *posn = to_fetch[i];
 345                 if (posn->status & REF_STATUS_UPTODATE)
 346                         continue;
 347
 348                 strbuf_addf(&buf, "fetch %s %s\n",
 349                             oid_to_hex(&posn->old_oid),
 350                             posn->symref ? posn->symref : posn->name);
 351         }
 352
 353         strbuf_addch(&buf, '\n');
 354         sendline(data, &buf);
 355
 356         while (1) {
 357                 if (recvline(data, &buf))
 358                         exit(128);
 359
 360                 if (starts_with(buf.buf, "lock ")) {
 361                         const char *name = buf.buf + 5;
 362                         if (transport->pack_lockfile)
 363                                 warning("%s also locked %s", data->name, name);
 364                         else
 365                                 transport->pack_lockfile = xstrdup(name);
 366                 }
 367                 else if (data->check_connectivity &&
 368                          data->transport_options.check_self_contained_and_connected &&
 369                          !strcmp(buf.buf, "connectivity-ok"))
 370                         data->transport_options.self_contained_and_connected = 1;
 371                 else if (!buf.len)
 372                         break;
 373                 else
 374                         warning("%s unexpectedly said: '%s'", data->name, buf.buf);
 375         }
 376         strbuf_release(&buf);
 377         return 0;
 378 }
 379
 380 static int get_importer(struct transport *transport, struct child_process *fastimport)
 381 {
 382         struct child_process *helper = get_helper(transport);
 383         struct helper_data *data = transport->data;
 384         int cat_blob_fd, code;
 385         child_process_init(fastimport);
 386         fastimport->in = helper->out;
 387         argv_array_push(&fastimport->args, "fast-import");
 388         argv_array_push(&fastimport->args, debug ? "--stats" : "--quiet");
 389
 390         if (data->bidi_import) {
 391                 cat_blob_fd = xdup(helper->in);
 392                 argv_array_pushf(&fastimport->args, "--cat-blob-fd=%d", cat_blob_fd);
 393         }
 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 i;
 407
 408         child_process_init(fastexport);
 409
 410         /* we need to duplicate helper->in because we want to use it after
 411          * fastexport is done with it. */
 412         fastexport->out = dup(helper->in);
 413         argv_array_push(&fastexport->args, "fast-export");
 414         argv_array_push(&fastexport->args, "--use-done-feature");
 415         argv_array_push(&fastexport->args, data->signed_tags ?
 416                 "--signed-tags=verbatim" : "--signed-tags=warn-strip");
 417         if (data->export_marks)
 418                 argv_array_pushf(&fastexport->args, "--export-marks=%s.tmp", data->export_marks);
 419         if (data->import_marks)
 420                 argv_array_pushf(&fastexport->args, "--import-marks=%s", data->import_marks);
 421
 422         for (i = 0; i < revlist_args->nr; i++)
 423                 argv_array_push(&fastexport->args, revlist_args->items[i].string);
 424
 425         fastexport->git_cmd = 1;
 426         return start_command(fastexport);
 427 }
 428
 429 static int fetch_with_import(struct transport *transport,
 430                              int nr_heads, struct ref **to_fetch)
 431 {
 432         struct child_process fastimport;
 433         struct helper_data *data = transport->data;
 434         int i;
 435         struct ref *posn;
 436         struct strbuf buf = STRBUF_INIT;
 437
 438         get_helper(transport);
 439
 440         if (get_importer(transport, &fastimport))
 441                 die("Couldn't run fast-import");
 442
 443         for (i = 0; i < nr_heads; i++) {
 444                 posn = to_fetch[i];
 445                 if (posn->status & REF_STATUS_UPTODATE)
 446                         continue;
 447
 448                 strbuf_addf(&buf, "import %s\n",
 449                             posn->symref ? posn->symref : posn->name);
 450                 sendline(data, &buf);
 451                 strbuf_reset(&buf);
 452         }
 453
 454         write_constant(data->helper->in, "\n");
 455         /*
 456          * remote-helpers that advertise the bidi-import capability are required to
 457          * buffer the complete batch of import commands until this newline before
 458          * sending data to fast-import.
 459          * These helpers read back data from fast-import on their stdin, which could
 460          * be mixed with import commands, otherwise.
 461          */
 462
 463         if (finish_command(&fastimport))
 464                 die("Error while running fast-import");
 465
 466         /*
 467          * The fast-import stream of a remote helper that advertises
 468          * the "refspec" capability writes to the refs named after the
 469          * right hand side of the first refspec matching each ref we
 470          * were fetching.
 471          *
 472          * (If no "refspec" capability was specified, for historical
 473          * reasons we default to the equivalent of *:*.)
 474          *
 475          * Store the result in to_fetch[i].old_sha1.  Callers such
 476          * as "git fetch" can use the value to write feedback to the
 477          * terminal, populate FETCH_HEAD, and determine what new value
 478          * should be written to peer_ref if the update is a
 479          * fast-forward or this is a forced update.
 480          */
 481         for (i = 0; i < nr_heads; i++) {
 482                 char *private, *name;
 483                 posn = to_fetch[i];
 484                 if (posn->status & REF_STATUS_UPTODATE)
 485                         continue;
 486                 name = posn->symref ? posn->symref : posn->name;
 487                 if (data->refspecs)
 488                         private = apply_refspecs(data->refspecs, data->refspec_nr, name);
 489                 else
 490                         private = xstrdup(name);
 491                 if (private) {
 492                         if (read_ref(private, posn->old_oid.hash) < 0)
 493                                 die("Could not read ref %s", private);
 494                         free(private);
 495                 }
 496         }
 497         strbuf_release(&buf);
 498         return 0;
 499 }
 500
 501 static int process_connect_service(struct transport *transport,
 502                                    const char *name, const char *exec)
 503 {
 504         struct helper_data *data = transport->data;
 505         struct strbuf cmdbuf = STRBUF_INIT;
 506         struct child_process *helper;
 507         int r, duped, ret = 0;
 508         FILE *input;
 509
 510         helper = get_helper(transport);
 511
 512         /*
 513          * Yes, dup the pipe another time, as we need unbuffered version
 514          * of input pipe as FILE*. fclose() closes the underlying fd and
 515          * stream buffering only can be changed before first I/O operation
 516          * on it.
 517          */
 518         duped = dup(helper->out);
 519         if (duped < 0)
 520                 die_errno("Can't dup helper output fd");
 521         input = xfdopen(duped, "r");
 522         setvbuf(input, NULL, _IONBF, 0);
 523
 524         /*
 525          * Handle --upload-pack and friends. This is fire and forget...
 526          * just warn if it fails.
 527          */
 528         if (strcmp(name, exec)) {
 529                 r = set_helper_option(transport, "servpath", exec);
 530                 if (r > 0)
 531                         warning("Setting remote service path not supported by protocol.");
 532                 else if (r < 0)
 533                         warning("Invalid remote service path.");
 534         }
 535
 536         if (data->connect)
 537                 strbuf_addf(&cmdbuf, "connect %s\n", name);
 538         else
 539                 goto exit;
 540
 541         sendline(data, &cmdbuf);
 542         if (recvline_fh(input, &cmdbuf, name))
 543                 exit(128);
 544
 545         if (!strcmp(cmdbuf.buf, "")) {
 546                 data->no_disconnect_req = 1;
 547                 if (debug)
 548                         fprintf(stderr, "Debug: Smart transport connection "
 549                                 "ready.\n");
 550                 ret = 1;
 551         } else if (!strcmp(cmdbuf.buf, "fallback")) {
 552                 if (debug)
 553                         fprintf(stderr, "Debug: Falling back to dumb "
 554                                 "transport.\n");
 555         } else
 556                 die("Unknown response to connect: %s",
 557                         cmdbuf.buf);
 558
 559 exit:
 560         fclose(input);
 561         return ret;
 562 }
 563
 564 static int process_connect(struct transport *transport,
 565                                      int for_push)
 566 {
 567         struct helper_data *data = transport->data;
 568         const char *name;
 569         const char *exec;
 570
 571         name = for_push ? "git-receive-pack" : "git-upload-pack";
 572         if (for_push)
 573                 exec = data->transport_options.receivepack;
 574         else
 575                 exec = data->transport_options.uploadpack;
 576
 577         return process_connect_service(transport, name, exec);
 578 }
 579
 580 static int connect_helper(struct transport *transport, const char *name,
 581                    const char *exec, int fd[2])
 582 {
 583         struct helper_data *data = transport->data;
 584
 585         /* Get_helper so connect is inited. */
 586         get_helper(transport);
 587         if (!data->connect)
 588                 die("Operation not supported by protocol.");
 589
 590         if (!process_connect_service(transport, name, exec))
 591                 die("Can't connect to subservice %s.", name);
 592
 593         fd[0] = data->helper->out;
 594         fd[1] = data->helper->in;
 595         return 0;
 596 }
 597
 598 static int fetch(struct transport *transport,
 599                  int nr_heads, struct ref **to_fetch)
 600 {
 601         struct helper_data *data = transport->data;
 602         int i, count;
 603
 604         if (process_connect(transport, 0)) {
 605                 do_take_over(transport);
 606                 return transport->fetch(transport, nr_heads, to_fetch);
 607         }
 608
 609         count = 0;
 610         for (i = 0; i < nr_heads; i++)
 611                 if (!(to_fetch[i]->status & REF_STATUS_UPTODATE))
 612                         count++;
 613
 614         if (!count)
 615                 return 0;
 616
 617         if (data->check_connectivity &&
 618             data->transport_options.check_self_contained_and_connected)
 619                 set_helper_option(transport, "check-connectivity", "true");
 620
 621         if (transport->cloning)
 622                 set_helper_option(transport, "cloning", "true");
 623
 624         if (data->transport_options.update_shallow)
 625                 set_helper_option(transport, "update-shallow", "true");
 626
 627         if (data->fetch)
 628                 return fetch_with_fetch(transport, nr_heads, to_fetch);
 629
 630         if (data->import)
 631                 return fetch_with_import(transport, nr_heads, to_fetch);
 632
 633         return -1;
 634 }
 635
 636 static int push_update_ref_status(struct strbuf *buf,
 637                                    struct ref **ref,
 638                                    struct ref *remote_refs)
 639 {
 640         char *refname, *msg;
 641         int status, forced = 0;
 642
 643         if (starts_with(buf->buf, "ok ")) {
 644                 status = REF_STATUS_OK;
 645                 refname = buf->buf + 3;
 646         } else if (starts_with(buf->buf, "error ")) {
 647                 status = REF_STATUS_REMOTE_REJECT;
 648                 refname = buf->buf + 6;
 649         } else
 650                 die("expected ok/error, helper said '%s'", buf->buf);
 651
 652         msg = strchr(refname, ' ');
 653         if (msg) {
 654                 struct strbuf msg_buf = STRBUF_INIT;
 655                 const char *end;
 656
 657                 *msg++ = '\0';
 658                 if (!unquote_c_style(&msg_buf, msg, &end))
 659                         msg = strbuf_detach(&msg_buf, NULL);
 660                 else
 661                         msg = xstrdup(msg);
 662                 strbuf_release(&msg_buf);
 663
 664                 if (!strcmp(msg, "no match")) {
 665                         status = REF_STATUS_NONE;
 666                         free(msg);
 667                         msg = NULL;
 668                 }
 669                 else if (!strcmp(msg, "up to date")) {
 670                         status = REF_STATUS_UPTODATE;
 671                         free(msg);
 672                         msg = NULL;
 673                 }
 674                 else if (!strcmp(msg, "non-fast forward")) {
 675                         status = REF_STATUS_REJECT_NONFASTFORWARD;
 676                         free(msg);
 677                         msg = NULL;
 678                 }
 679                 else if (!strcmp(msg, "already exists")) {
 680                         status = REF_STATUS_REJECT_ALREADY_EXISTS;
 681                         free(msg);
 682                         msg = NULL;
 683                 }
 684                 else if (!strcmp(msg, "fetch first")) {
 685                         status = REF_STATUS_REJECT_FETCH_FIRST;
 686                         free(msg);
 687                         msg = NULL;
 688                 }
 689                 else if (!strcmp(msg, "needs force")) {
 690                         status = REF_STATUS_REJECT_NEEDS_FORCE;
 691                         free(msg);
 692                         msg = NULL;
 693                 }
 694                 else if (!strcmp(msg, "stale info")) {
 695                         status = REF_STATUS_REJECT_STALE;
 696                         free(msg);
 697                         msg = NULL;
 698                 }
 699                 else if (!strcmp(msg, "forced update")) {
 700                         forced = 1;
 701                         free(msg);
 702                         msg = NULL;
 703                 }
 704         }
 705
 706         if (*ref)
 707                 *ref = find_ref_by_name(*ref, refname);
 708         if (!*ref)
 709                 *ref = find_ref_by_name(remote_refs, refname);
 710         if (!*ref) {
 711                 warning("helper reported unexpected status of %s", refname);
 712                 return 1;
 713         }
 714
 715         if ((*ref)->status != REF_STATUS_NONE) {
 716                 /*
 717                  * Earlier, the ref was marked not to be pushed, so ignore the ref
 718                  * status reported by the remote helper if the latter is 'no match'.
 719                  */
 720                 if (status == REF_STATUS_NONE)
 721                         return 1;
 722         }
 723
 724         (*ref)->status = status;
 725         (*ref)->forced_update |= forced;
 726         (*ref)->remote_status = msg;
 727         return !(status == REF_STATUS_OK);
 728 }
 729
 730 static int push_update_refs_status(struct helper_data *data,
 731                                     struct ref *remote_refs,
 732                                     int flags)
 733 {
 734         struct strbuf buf = STRBUF_INIT;
 735         struct ref *ref = remote_refs;
 736         int ret = 0;
 737
 738         for (;;) {
 739                 char *private;
 740
 741                 if (recvline(data, &buf)) {
 742                         ret = 1;
 743                         break;
 744                 }
 745
 746                 if (!buf.len)
 747                         break;
 748
 749                 if (push_update_ref_status(&buf, &ref, remote_refs))
 750                         continue;
 751
 752                 if (flags & TRANSPORT_PUSH_DRY_RUN || !data->refspecs || data->no_private_update)
 753                         continue;
 754
 755                 /* propagate back the update to the remote namespace */
 756                 private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
 757                 if (!private)
 758                         continue;
 759                 update_ref("update by helper", private, ref->new_oid.hash, NULL, 0, 0);
 760                 free(private);
 761         }
 762         strbuf_release(&buf);
 763         return ret;
 764 }
 765
 766 static void set_common_push_options(struct transport *transport,
 767                                    const char *name, int flags)
 768 {
 769         if (flags & TRANSPORT_PUSH_DRY_RUN) {
 770                 if (set_helper_option(transport, "dry-run", "true") != 0)
 771                         die("helper %s does not support dry-run", name);
 772         } else if (flags & TRANSPORT_PUSH_CERT_ALWAYS) {
 773                 if (set_helper_option(transport, TRANS_OPT_PUSH_CERT, "true") != 0)
 774                         die("helper %s does not support --signed", name);
 775         } else if (flags & TRANSPORT_PUSH_CERT_IF_ASKED) {
 776                 if (set_helper_option(transport, TRANS_OPT_PUSH_CERT, "if-asked") != 0)
 777                         die("helper %s does not support --signed=if-asked", name);
 778         }
 779 }
 780
 781 static int push_refs_with_push(struct transport *transport,
 782                                struct ref *remote_refs, int flags)
 783 {
 784         int force_all = flags & TRANSPORT_PUSH_FORCE;
 785         int mirror = flags & TRANSPORT_PUSH_MIRROR;
 786         struct helper_data *data = transport->data;
 787         struct strbuf buf = STRBUF_INIT;
 788         struct ref *ref;
 789         struct string_list cas_options = STRING_LIST_INIT_DUP;
 790         struct string_list_item *cas_option;
 791
 792         get_helper(transport);
 793         if (!data->push)
 794                 return 1;
 795
 796         for (ref = remote_refs; ref; ref = ref->next) {
 797                 if (!ref->peer_ref && !mirror)
 798                         continue;
 799
 800                 /* Check for statuses set by set_ref_status_for_push() */
 801                 switch (ref->status) {
 802                 case REF_STATUS_REJECT_NONFASTFORWARD:
 803                 case REF_STATUS_REJECT_STALE:
 804                 case REF_STATUS_REJECT_ALREADY_EXISTS:
 805                 case REF_STATUS_UPTODATE:
 806                         continue;
 807                 default:
 808                         ; /* do nothing */
 809                 }
 810
 811                 if (force_all)
 812                         ref->force = 1;
 813
 814                 strbuf_addstr(&buf, "push ");
 815                 if (!ref->deletion) {
 816                         if (ref->force)
 817                                 strbuf_addch(&buf, '+');
 818                         if (ref->peer_ref)
 819                                 strbuf_addstr(&buf, ref->peer_ref->name);
 820                         else
 821                                 strbuf_addstr(&buf, oid_to_hex(&ref->new_oid));
 822                 }
 823                 strbuf_addch(&buf, ':');
 824                 strbuf_addstr(&buf, ref->name);
 825                 strbuf_addch(&buf, '\n');
 826
 827                 /*
 828                  * The "--force-with-lease" options without explicit
 829                  * values to expect have already been expanded into
 830                  * the ref->old_oid_expect[] field; we can ignore
 831                  * transport->smart_options->cas altogether and instead
 832                  * can enumerate them from the refs.
 833                  */
 834                 if (ref->expect_old_sha1) {
 835                         struct strbuf cas = STRBUF_INIT;
 836                         strbuf_addf(&cas, "%s:%s",
 837                                     ref->name, oid_to_hex(&ref->old_oid_expect));
 838                         string_list_append(&cas_options, strbuf_detach(&cas, NULL));
 839                 }
 840         }
 841         if (buf.len == 0) {
 842                 string_list_clear(&cas_options, 0);
 843                 return 0;
 844         }
 845
 846         for_each_string_list_item(cas_option, &cas_options)
 847                 set_helper_option(transport, "cas", cas_option->string);
 848         set_common_push_options(transport, data->name, flags);
 849
 850         strbuf_addch(&buf, '\n');
 851         sendline(data, &buf);
 852         strbuf_release(&buf);
 853
 854         return push_update_refs_status(data, remote_refs, flags);
 855 }
 856
 857 static int push_refs_with_export(struct transport *transport,
 858                 struct ref *remote_refs, int flags)
 859 {
 860         struct ref *ref;
 861         struct child_process *helper, exporter;
 862         struct helper_data *data = transport->data;
 863         struct string_list revlist_args = STRING_LIST_INIT_DUP;
 864         struct strbuf buf = STRBUF_INIT;
 865
 866         if (!data->refspecs)
 867                 die("remote-helper doesn't support push; refspec needed");
 868
 869         set_common_push_options(transport, data->name, flags);
 870         if (flags & TRANSPORT_PUSH_FORCE) {
 871                 if (set_helper_option(transport, "force", "true") != 0)
 872                         warning("helper %s does not support 'force'", data->name);
 873         }
 874
 875         helper = get_helper(transport);
 876
 877         write_constant(helper->in, "export\n");
 878
 879         for (ref = remote_refs; ref; ref = ref->next) {
 880                 char *private;
 881                 struct object_id oid;
 882
 883                 private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
 884                 if (private && !get_sha1(private, oid.hash)) {
 885                         strbuf_addf(&buf, "^%s", private);
 886                         string_list_append(&revlist_args, strbuf_detach(&buf, NULL));
 887                         oidcpy(&ref->old_oid, &oid);
 888                 }
 889                 free(private);
 890
 891                 if (ref->peer_ref) {
 892                         if (strcmp(ref->name, ref->peer_ref->name)) {
 893                                 if (!ref->deletion) {
 894                                         const char *name;
 895                                         int flag;
 896
 897                                         /* Follow symbolic refs (mainly for HEAD). */
 898                                         name = resolve_ref_unsafe(
 899                                                  ref->peer_ref->name,
 900                                                  RESOLVE_REF_READING,
 901                                                  oid.hash, &flag);
 902                                         if (!name || !(flag & REF_ISSYMREF))
 903                                                 name = ref->peer_ref->name;
 904
 905                                         strbuf_addf(&buf, "%s:%s", name, ref->name);
 906                                 } else
 907                                         strbuf_addf(&buf, ":%s", ref->name);
 908
 909                                 string_list_append(&revlist_args, "--refspec");
 910                                 string_list_append(&revlist_args, buf.buf);
 911                                 strbuf_release(&buf);
 912                         }
 913                         if (!ref->deletion)
 914                                 string_list_append(&revlist_args, ref->peer_ref->name);
 915                 }
 916         }
 917
 918         if (get_exporter(transport, &exporter, &revlist_args))
 919                 die("Couldn't run fast-export");
 920
 921         string_list_clear(&revlist_args, 1);
 922
 923         if (finish_command(&exporter))
 924                 die("Error while running fast-export");
 925         if (push_update_refs_status(data, remote_refs, flags))
 926                 return 1;
 927
 928         if (data->export_marks) {
 929                 strbuf_addf(&buf, "%s.tmp", data->export_marks);
 930                 rename(buf.buf, data->export_marks);
 931                 strbuf_release(&buf);
 932         }
 933
 934         return 0;
 935 }
 936
 937 static int push_refs(struct transport *transport,
 938                 struct ref *remote_refs, int flags)
 939 {
 940         struct helper_data *data = transport->data;
 941
 942         if (process_connect(transport, 1)) {
 943                 do_take_over(transport);
 944                 return transport->push_refs(transport, remote_refs, flags);
 945         }
 946
 947         if (!remote_refs) {
 948                 fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
 949                         "Perhaps you should specify a branch such as 'master'.\n");
 950                 return 0;
 951         }
 952
 953         if (data->push)
 954                 return push_refs_with_push(transport, remote_refs, flags);
 955
 956         if (data->export)
 957                 return push_refs_with_export(transport, remote_refs, flags);
 958
 959         return -1;
 960 }
 961
 962
 963 static int has_attribute(const char *attrs, const char *attr) {
 964         int len;
 965         if (!attrs)
 966                 return 0;
 967
 968         len = strlen(attr);
 969         for (;;) {
 970                 const char *space = strchrnul(attrs, ' ');
 971                 if (len == space - attrs && !strncmp(attrs, attr, len))
 972                         return 1;
 973                 if (!*space)
 974                         return 0;
 975                 attrs = space + 1;
 976         }
 977 }
 978
 979 static struct ref *get_refs_list(struct transport *transport, int for_push)
 980 {
 981         struct helper_data *data = transport->data;
 982         struct child_process *helper;
 983         struct ref *ret = NULL;
 984         struct ref **tail = &ret;
 985         struct ref *posn;
 986         struct strbuf buf = STRBUF_INIT;
 987
 988         helper = get_helper(transport);
 989
 990         if (process_connect(transport, for_push)) {
 991                 do_take_over(transport);
 992                 return transport->get_refs_list(transport, for_push);
 993         }
 994
 995         if (data->push && for_push)
 996                 write_str_in_full(helper->in, "list for-push\n");
 997         else
 998                 write_str_in_full(helper->in, "list\n");
 999
1000         while (1) {
1001                 char *eov, *eon;
1002                 if (recvline(data, &buf))
1003                         exit(128);
1004
1005                 if (!*buf.buf)
1006                         break;
1007
1008                 eov = strchr(buf.buf, ' ');
1009                 if (!eov)
1010                         die("Malformed response in ref list: %s", buf.buf);
1011                 eon = strchr(eov + 1, ' ');
1012                 *eov = '\0';
1013                 if (eon)
1014                         *eon = '\0';
1015                 *tail = alloc_ref(eov + 1);
1016                 if (buf.buf[0] == '@')
1017                         (*tail)->symref = xstrdup(buf.buf + 1);
1018                 else if (buf.buf[0] != '?')
1019                         get_oid_hex(buf.buf, &(*tail)->old_oid);
1020                 if (eon) {
1021                         if (has_attribute(eon + 1, "unchanged")) {
1022                                 (*tail)->status |= REF_STATUS_UPTODATE;
1023                                 if (read_ref((*tail)->name,
1024                                              (*tail)->old_oid.hash) < 0)
1025                                         die(N_("Could not read ref %s"),
1026                                             (*tail)->name);
1027                         }
1028                 }
1029                 tail = &((*tail)->next);
1030         }
1031         if (debug)
1032                 fprintf(stderr, "Debug: Read ref listing.\n");
1033         strbuf_release(&buf);
1034
1035         for (posn = ret; posn; posn = posn->next)
1036                 resolve_remote_symref(posn, ret);
1037
1038         return ret;
1039 }
1040
1041 int transport_helper_init(struct transport *transport, const char *name)
1042 {
1043         struct helper_data *data = xcalloc(1, sizeof(*data));
1044         data->name = name;
1045
1046         transport_check_allowed(name);
1047
1048         if (getenv("GIT_TRANSPORT_HELPER_DEBUG"))
1049                 debug = 1;
1050
1051         transport->data = data;
1052         transport->set_option = set_helper_option;
1053         transport->get_refs_list = get_refs_list;
1054         transport->fetch = fetch;
1055         transport->push_refs = push_refs;
1056         transport->disconnect = release_helper;
1057         transport->connect = connect_helper;
1058         transport->smart_options = &(data->transport_options);
1059         return 0;
1060 }
1061
1062 /*
1063  * Linux pipes can buffer 65536 bytes at once (and most platforms can
1064  * buffer less), so attempt reads and writes with up to that size.
1065  */
1066 #define BUFFERSIZE 65536
1067 /* This should be enough to hold debugging message. */
1068 #define PBUFFERSIZE 8192
1069
1070 /* Print bidirectional transfer loop debug message. */
1071 __attribute__((format (printf, 1, 2)))
1072 static void transfer_debug(const char *fmt, ...)
1073 {
1074         va_list args;
1075         char msgbuf[PBUFFERSIZE];
1076         static int debug_enabled = -1;
1077
1078         if (debug_enabled < 0)
1079                 debug_enabled = getenv("GIT_TRANSLOOP_DEBUG") ? 1 : 0;
1080         if (!debug_enabled)
1081                 return;
1082
1083         va_start(args, fmt);
1084         vsnprintf(msgbuf, PBUFFERSIZE, fmt, args);
1085         va_end(args);
1086         fprintf(stderr, "Transfer loop debugging: %s\n", msgbuf);
1087 }
1088
1089 /* Stream state: More data may be coming in this direction. */
1090 #define SSTATE_TRANSFERING 0
1091 /*
1092  * Stream state: No more data coming in this direction, flushing rest of
1093  * data.
1094  */
1095 #define SSTATE_FLUSHING 1
1096 /* Stream state: Transfer in this direction finished. */
1097 #define SSTATE_FINISHED 2
1098
1099 #define STATE_NEEDS_READING(state) ((state) <= SSTATE_TRANSFERING)
1100 #define STATE_NEEDS_WRITING(state) ((state) <= SSTATE_FLUSHING)
1101 #define STATE_NEEDS_CLOSING(state) ((state) == SSTATE_FLUSHING)
1102
1103 /* Unidirectional transfer. */
1104 struct unidirectional_transfer {
1105         /* Source */
1106         int src;
1107         /* Destination */
1108         int dest;
1109         /* Is source socket? */
1110         int src_is_sock;
1111         /* Is destination socket? */
1112         int dest_is_sock;
1113         /* Transfer state (TRANSFERRING/FLUSHING/FINISHED) */
1114         int state;
1115         /* Buffer. */
1116         char buf[BUFFERSIZE];
1117         /* Buffer used. */
1118         size_t bufuse;
1119         /* Name of source. */
1120         const char *src_name;
1121         /* Name of destination. */
1122         const char *dest_name;
1123 };
1124
1125 /* Closes the target (for writing) if transfer has finished. */
1126 static void udt_close_if_finished(struct unidirectional_transfer *t)
1127 {
1128         if (STATE_NEEDS_CLOSING(t->state) && !t->bufuse) {
1129                 t->state = SSTATE_FINISHED;
1130                 if (t->dest_is_sock)
1131                         shutdown(t->dest, SHUT_WR);
1132                 else
1133                         close(t->dest);
1134                 transfer_debug("Closed %s.", t->dest_name);
1135         }
1136 }
1137
1138 /*
1139  * Tries to read read data from source into buffer. If buffer is full,
1140  * no data is read. Returns 0 on success, -1 on error.
1141  */
1142 static int udt_do_read(struct unidirectional_transfer *t)
1143 {
1144         ssize_t bytes;
1145
1146         if (t->bufuse == BUFFERSIZE)
1147                 return 0;       /* No space for more. */
1148
1149         transfer_debug("%s is readable", t->src_name);
1150         bytes = read(t->src, t->buf + t->bufuse, BUFFERSIZE - t->bufuse);
1151         if (bytes < 0 && errno != EWOULDBLOCK && errno != EAGAIN &&
1152                 errno != EINTR) {
1153                 error("read(%s) failed: %s", t->src_name, strerror(errno));
1154                 return -1;
1155         } else if (bytes == 0) {
1156                 transfer_debug("%s EOF (with %i bytes in buffer)",
1157                         t->src_name, (int)t->bufuse);
1158                 t->state = SSTATE_FLUSHING;
1159         } else if (bytes > 0) {
1160                 t->bufuse += bytes;
1161                 transfer_debug("Read %i bytes from %s (buffer now at %i)",
1162                         (int)bytes, t->src_name, (int)t->bufuse);
1163         }
1164         return 0;
1165 }
1166
1167 /* Tries to write data from buffer into destination. If buffer is empty,
1168  * no data is written. Returns 0 on success, -1 on error.
1169  */
1170 static int udt_do_write(struct unidirectional_transfer *t)
1171 {
1172         ssize_t bytes;
1173
1174         if (t->bufuse == 0)
1175                 return 0;       /* Nothing to write. */
1176
1177         transfer_debug("%s is writable", t->dest_name);
1178         bytes = xwrite(t->dest, t->buf, t->bufuse);
1179         if (bytes < 0 && errno != EWOULDBLOCK) {
1180                 error("write(%s) failed: %s", t->dest_name, strerror(errno));
1181                 return -1;
1182         } else if (bytes > 0) {
1183                 t->bufuse -= bytes;
1184                 if (t->bufuse)
1185                         memmove(t->buf, t->buf + bytes, t->bufuse);
1186                 transfer_debug("Wrote %i bytes to %s (buffer now at %i)",
1187                         (int)bytes, t->dest_name, (int)t->bufuse);
1188         }
1189         return 0;
1190 }
1191
1192
1193 /* State of bidirectional transfer loop. */
1194 struct bidirectional_transfer_state {
1195         /* Direction from program to git. */
1196         struct unidirectional_transfer ptg;
1197         /* Direction from git to program. */
1198         struct unidirectional_transfer gtp;
1199 };
1200
1201 static void *udt_copy_task_routine(void *udt)
1202 {
1203         struct unidirectional_transfer *t = (struct unidirectional_transfer *)udt;
1204         while (t->state != SSTATE_FINISHED) {
1205                 if (STATE_NEEDS_READING(t->state))
1206                         if (udt_do_read(t))
1207                                 return NULL;
1208                 if (STATE_NEEDS_WRITING(t->state))
1209                         if (udt_do_write(t))
1210                                 return NULL;
1211                 if (STATE_NEEDS_CLOSING(t->state))
1212                         udt_close_if_finished(t);
1213         }
1214         return udt;     /* Just some non-NULL value. */
1215 }
1216
1217 #ifndef NO_PTHREADS
1218
1219 /*
1220  * Join thread, with appropriate errors on failure. Name is name for the
1221  * thread (for error messages). Returns 0 on success, 1 on failure.
1222  */
1223 static int tloop_join(pthread_t thread, const char *name)
1224 {
1225         int err;
1226         void *tret;
1227         err = pthread_join(thread, &tret);
1228         if (!tret) {
1229                 error("%s thread failed", name);
1230                 return 1;
1231         }
1232         if (err) {
1233                 error("%s thread failed to join: %s", name, strerror(err));
1234                 return 1;
1235         }
1236         return 0;
1237 }
1238
1239 /*
1240  * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1241  * -1 on failure.
1242  */
1243 static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1244 {
1245         pthread_t gtp_thread;
1246         pthread_t ptg_thread;
1247         int err;
1248         int ret = 0;
1249         err = pthread_create(&gtp_thread, NULL, udt_copy_task_routine,
1250                 &s->gtp);
1251         if (err)
1252                 die("Can't start thread for copying data: %s", strerror(err));
1253         err = pthread_create(&ptg_thread, NULL, udt_copy_task_routine,
1254                 &s->ptg);
1255         if (err)
1256                 die("Can't start thread for copying data: %s", strerror(err));
1257
1258         ret |= tloop_join(gtp_thread, "Git to program copy");
1259         ret |= tloop_join(ptg_thread, "Program to git copy");
1260         return ret;
1261 }
1262 #else
1263
1264 /* Close the source and target (for writing) for transfer. */
1265 static void udt_kill_transfer(struct unidirectional_transfer *t)
1266 {
1267         t->state = SSTATE_FINISHED;
1268         /*
1269          * Socket read end left open isn't a disaster if nobody
1270          * attempts to read from it (mingw compat headers do not
1271          * have SHUT_RD)...
1272          *
1273          * We can't fully close the socket since otherwise gtp
1274          * task would first close the socket it sends data to
1275          * while closing the ptg file descriptors.
1276          */
1277         if (!t->src_is_sock)
1278                 close(t->src);
1279         if (t->dest_is_sock)
1280                 shutdown(t->dest, SHUT_WR);
1281         else
1282                 close(t->dest);
1283 }
1284
1285 /*
1286  * Join process, with appropriate errors on failure. Name is name for the
1287  * process (for error messages). Returns 0 on success, 1 on failure.
1288  */
1289 static int tloop_join(pid_t pid, const char *name)
1290 {
1291         int tret;
1292         if (waitpid(pid, &tret, 0) < 0) {
1293                 error("%s process failed to wait: %s", name, strerror(errno));
1294                 return 1;
1295         }
1296         if (!WIFEXITED(tret) || WEXITSTATUS(tret)) {
1297                 error("%s process failed", name);
1298                 return 1;
1299         }
1300         return 0;
1301 }
1302
1303 /*
1304  * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1305  * -1 on failure.
1306  */
1307 static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1308 {
1309         pid_t pid1, pid2;
1310         int ret = 0;
1311
1312         /* Fork thread #1: git to program. */
1313         pid1 = fork();
1314         if (pid1 < 0)
1315                 die_errno("Can't start thread for copying data");
1316         else if (pid1 == 0) {
1317                 udt_kill_transfer(&s->ptg);
1318                 exit(udt_copy_task_routine(&s->gtp) ? 0 : 1);
1319         }
1320
1321         /* Fork thread #2: program to git. */
1322         pid2 = fork();
1323         if (pid2 < 0)
1324                 die_errno("Can't start thread for copying data");
1325         else if (pid2 == 0) {
1326                 udt_kill_transfer(&s->gtp);
1327                 exit(udt_copy_task_routine(&s->ptg) ? 0 : 1);
1328         }
1329
1330         /*
1331          * Close both streams in parent as to not interfere with
1332          * end of file detection and wait for both tasks to finish.
1333          */
1334         udt_kill_transfer(&s->gtp);
1335         udt_kill_transfer(&s->ptg);
1336         ret |= tloop_join(pid1, "Git to program copy");
1337         ret |= tloop_join(pid2, "Program to git copy");
1338         return ret;
1339 }
1340 #endif
1341
1342 /*
1343  * Copies data from stdin to output and from input to stdout simultaneously.
1344  * Additionally filtering through given filter. If filter is NULL, uses
1345  * identity filter.
1346  */
1347 int bidirectional_transfer_loop(int input, int output)
1348 {
1349         struct bidirectional_transfer_state state;
1350
1351         /* Fill the state fields. */
1352         state.ptg.src = input;
1353         state.ptg.dest = 1;
1354         state.ptg.src_is_sock = (input == output);
1355         state.ptg.dest_is_sock = 0;
1356         state.ptg.state = SSTATE_TRANSFERING;
1357         state.ptg.bufuse = 0;
1358         state.ptg.src_name = "remote input";
1359         state.ptg.dest_name = "stdout";
1360
1361         state.gtp.src = 0;
1362         state.gtp.dest = output;
1363         state.gtp.src_is_sock = 0;
1364         state.gtp.dest_is_sock = (input == output);
1365         state.gtp.state = SSTATE_TRANSFERING;
1366         state.gtp.bufuse = 0;
1367         state.gtp.src_name = "stdin";
1368         state.gtp.dest_name = "remote output";
1369
1370         return tloop_spawnwait_tasks(&state);
1371 }