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

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