transport-helper.con commit pull: support pull.ff config (a9de989)
   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
  15static int debug;
  16
  17struct 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
  43static 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
  52static 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
  68static int recvline(struct helper_data *helper, struct strbuf *buffer)
  69{
  70        return recvline_fh(helper->out, buffer, helper->name);
  71}
  72
  73static 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
  81static 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
  91static 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
 100static void standard_options(struct transport *t);
 101
 102static 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
 220static 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
 249static const char *unsupported_options[] = {
 250        TRANS_OPT_UPLOADPACK,
 251        TRANS_OPT_RECEIVEPACK,
 252        TRANS_OPT_THIN,
 253        TRANS_OPT_KEEP
 254        };
 255
 256static const char *boolean_options[] = {
 257        TRANS_OPT_THIN,
 258        TRANS_OPT_KEEP,
 259        TRANS_OPT_FOLLOWTAGS,
 260        TRANS_OPT_PUSH_CERT
 261        };
 262
 263static int set_helper_option(struct transport *transport,
 264                          const char *name, const char *value)
 265{
 266        struct helper_data *data = transport->data;
 267        struct strbuf buf = STRBUF_INIT;
 268        int i, ret, is_bool = 0;
 269
 270        get_helper(transport);
 271
 272        if (!data->option)
 273                return 1;
 274
 275        for (i = 0; i < ARRAY_SIZE(unsupported_options); i++) {
 276                if (!strcmp(name, unsupported_options[i]))
 277                        return 1;
 278        }
 279
 280        for (i = 0; i < ARRAY_SIZE(boolean_options); i++) {
 281                if (!strcmp(name, boolean_options[i])) {
 282                        is_bool = 1;
 283                        break;
 284                }
 285        }
 286
 287        strbuf_addf(&buf, "option %s ", name);
 288        if (is_bool)
 289                strbuf_addstr(&buf, value ? "true" : "false");
 290        else
 291                quote_c_style(value, &buf, NULL, 0);
 292        strbuf_addch(&buf, '\n');
 293
 294        sendline(data, &buf);
 295        if (recvline(data, &buf))
 296                exit(128);
 297
 298        if (!strcmp(buf.buf, "ok"))
 299                ret = 0;
 300        else if (starts_with(buf.buf, "error")) {
 301                ret = -1;
 302        } else if (!strcmp(buf.buf, "unsupported"))
 303                ret = 1;
 304        else {
 305                warning("%s unexpectedly said: '%s'", data->name, buf.buf);
 306                ret = 1;
 307        }
 308        strbuf_release(&buf);
 309        return ret;
 310}
 311
 312static void standard_options(struct transport *t)
 313{
 314        char buf[16];
 315        int n;
 316        int v = t->verbose;
 317
 318        set_helper_option(t, "progress", t->progress ? "true" : "false");
 319
 320        n = snprintf(buf, sizeof(buf), "%d", v + 1);
 321        if (n >= sizeof(buf))
 322                die("impossibly large verbosity value");
 323        set_helper_option(t, "verbosity", buf);
 324}
 325
 326static int release_helper(struct transport *transport)
 327{
 328        int res = 0;
 329        struct helper_data *data = transport->data;
 330        free_refspec(data->refspec_nr, data->refspecs);
 331        data->refspecs = NULL;
 332        res = disconnect_helper(transport);
 333        free(transport->data);
 334        return res;
 335}
 336
 337static int fetch_with_fetch(struct transport *transport,
 338                            int nr_heads, struct ref **to_fetch)
 339{
 340        struct helper_data *data = transport->data;
 341        int i;
 342        struct strbuf buf = STRBUF_INIT;
 343
 344        for (i = 0; i < nr_heads; i++) {
 345                const struct ref *posn = to_fetch[i];
 346                if (posn->status & REF_STATUS_UPTODATE)
 347                        continue;
 348
 349                strbuf_addf(&buf, "fetch %s %s\n",
 350                            sha1_to_hex(posn->old_sha1),
 351                            posn->symref ? posn->symref : posn->name);
 352        }
 353
 354        strbuf_addch(&buf, '\n');
 355        sendline(data, &buf);
 356
 357        while (1) {
 358                if (recvline(data, &buf))
 359                        exit(128);
 360
 361                if (starts_with(buf.buf, "lock ")) {
 362                        const char *name = buf.buf + 5;
 363                        if (transport->pack_lockfile)
 364                                warning("%s also locked %s", data->name, name);
 365                        else
 366                                transport->pack_lockfile = xstrdup(name);
 367                }
 368                else if (data->check_connectivity &&
 369                         data->transport_options.check_self_contained_and_connected &&
 370                         !strcmp(buf.buf, "connectivity-ok"))
 371                        data->transport_options.self_contained_and_connected = 1;
 372                else if (!buf.len)
 373                        break;
 374                else
 375                        warning("%s unexpectedly said: '%s'", data->name, buf.buf);
 376        }
 377        strbuf_release(&buf);
 378        return 0;
 379}
 380
 381static int get_importer(struct transport *transport, struct child_process *fastimport)
 382{
 383        struct child_process *helper = get_helper(transport);
 384        struct helper_data *data = transport->data;
 385        int cat_blob_fd, code;
 386        child_process_init(fastimport);
 387        fastimport->in = helper->out;
 388        argv_array_push(&fastimport->args, "fast-import");
 389        argv_array_push(&fastimport->args, debug ? "--stats" : "--quiet");
 390
 391        if (data->bidi_import) {
 392                cat_blob_fd = xdup(helper->in);
 393                argv_array_pushf(&fastimport->args, "--cat-blob-fd=%d", cat_blob_fd);
 394        }
 395        fastimport->git_cmd = 1;
 396
 397        code = start_command(fastimport);
 398        return code;
 399}
 400
 401static int get_exporter(struct transport *transport,
 402                        struct child_process *fastexport,
 403                        struct string_list *revlist_args)
 404{
 405        struct helper_data *data = transport->data;
 406        struct child_process *helper = get_helper(transport);
 407        int i;
 408
 409        child_process_init(fastexport);
 410
 411        /* we need to duplicate helper->in because we want to use it after
 412         * fastexport is done with it. */
 413        fastexport->out = dup(helper->in);
 414        argv_array_push(&fastexport->args, "fast-export");
 415        argv_array_push(&fastexport->args, "--use-done-feature");
 416        argv_array_push(&fastexport->args, data->signed_tags ?
 417                "--signed-tags=verbatim" : "--signed-tags=warn-strip");
 418        if (data->export_marks)
 419                argv_array_pushf(&fastexport->args, "--export-marks=%s.tmp", data->export_marks);
 420        if (data->import_marks)
 421                argv_array_pushf(&fastexport->args, "--import-marks=%s", data->import_marks);
 422
 423        for (i = 0; i < revlist_args->nr; i++)
 424                argv_array_push(&fastexport->args, revlist_args->items[i].string);
 425
 426        fastexport->git_cmd = 1;
 427        return start_command(fastexport);
 428}
 429
 430static int fetch_with_import(struct transport *transport,
 431                             int nr_heads, struct ref **to_fetch)
 432{
 433        struct child_process fastimport;
 434        struct helper_data *data = transport->data;
 435        int i;
 436        struct ref *posn;
 437        struct strbuf buf = STRBUF_INIT;
 438
 439        get_helper(transport);
 440
 441        if (get_importer(transport, &fastimport))
 442                die("Couldn't run fast-import");
 443
 444        for (i = 0; i < nr_heads; i++) {
 445                posn = to_fetch[i];
 446                if (posn->status & REF_STATUS_UPTODATE)
 447                        continue;
 448
 449                strbuf_addf(&buf, "import %s\n",
 450                            posn->symref ? posn->symref : posn->name);
 451                sendline(data, &buf);
 452                strbuf_reset(&buf);
 453        }
 454
 455        write_constant(data->helper->in, "\n");
 456        /*
 457         * remote-helpers that advertise the bidi-import capability are required to
 458         * buffer the complete batch of import commands until this newline before
 459         * sending data to fast-import.
 460         * These helpers read back data from fast-import on their stdin, which could
 461         * be mixed with import commands, otherwise.
 462         */
 463
 464        if (finish_command(&fastimport))
 465                die("Error while running fast-import");
 466
 467        /*
 468         * The fast-import stream of a remote helper that advertises
 469         * the "refspec" capability writes to the refs named after the
 470         * right hand side of the first refspec matching each ref we
 471         * were fetching.
 472         *
 473         * (If no "refspec" capability was specified, for historical
 474         * reasons we default to the equivalent of *:*.)
 475         *
 476         * Store the result in to_fetch[i].old_sha1.  Callers such
 477         * as "git fetch" can use the value to write feedback to the
 478         * terminal, populate FETCH_HEAD, and determine what new value
 479         * should be written to peer_ref if the update is a
 480         * fast-forward or this is a forced update.
 481         */
 482        for (i = 0; i < nr_heads; i++) {
 483                char *private, *name;
 484                posn = to_fetch[i];
 485                if (posn->status & REF_STATUS_UPTODATE)
 486                        continue;
 487                name = posn->symref ? posn->symref : posn->name;
 488                if (data->refspecs)
 489                        private = apply_refspecs(data->refspecs, data->refspec_nr, name);
 490                else
 491                        private = xstrdup(name);
 492                if (private) {
 493                        read_ref(private, posn->old_sha1);
 494                        free(private);
 495                }
 496        }
 497        strbuf_release(&buf);
 498        return 0;
 499}
 500
 501static 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
 559exit:
 560        fclose(input);
 561        return ret;
 562}
 563
 564static 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
 580static 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
 598static 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
 636static 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
 730static 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_sha1, NULL, 0, 0);
 760                free(private);
 761        }
 762        strbuf_release(&buf);
 763        return ret;
 764}
 765
 766static int push_refs_with_push(struct transport *transport,
 767                               struct ref *remote_refs, int flags)
 768{
 769        int force_all = flags & TRANSPORT_PUSH_FORCE;
 770        int mirror = flags & TRANSPORT_PUSH_MIRROR;
 771        struct helper_data *data = transport->data;
 772        struct strbuf buf = STRBUF_INIT;
 773        struct ref *ref;
 774        struct string_list cas_options = STRING_LIST_INIT_DUP;
 775        struct string_list_item *cas_option;
 776
 777        get_helper(transport);
 778        if (!data->push)
 779                return 1;
 780
 781        for (ref = remote_refs; ref; ref = ref->next) {
 782                if (!ref->peer_ref && !mirror)
 783                        continue;
 784
 785                /* Check for statuses set by set_ref_status_for_push() */
 786                switch (ref->status) {
 787                case REF_STATUS_REJECT_NONFASTFORWARD:
 788                case REF_STATUS_REJECT_STALE:
 789                case REF_STATUS_REJECT_ALREADY_EXISTS:
 790                case REF_STATUS_UPTODATE:
 791                        continue;
 792                default:
 793                        ; /* do nothing */
 794                }
 795
 796                if (force_all)
 797                        ref->force = 1;
 798
 799                strbuf_addstr(&buf, "push ");
 800                if (!ref->deletion) {
 801                        if (ref->force)
 802                                strbuf_addch(&buf, '+');
 803                        if (ref->peer_ref)
 804                                strbuf_addstr(&buf, ref->peer_ref->name);
 805                        else
 806                                strbuf_addstr(&buf, sha1_to_hex(ref->new_sha1));
 807                }
 808                strbuf_addch(&buf, ':');
 809                strbuf_addstr(&buf, ref->name);
 810                strbuf_addch(&buf, '\n');
 811
 812                /*
 813                 * The "--force-with-lease" options without explicit
 814                 * values to expect have already been expanded into
 815                 * the ref->old_sha1_expect[] field; we can ignore
 816                 * transport->smart_options->cas altogether and instead
 817                 * can enumerate them from the refs.
 818                 */
 819                if (ref->expect_old_sha1) {
 820                        struct strbuf cas = STRBUF_INIT;
 821                        strbuf_addf(&cas, "%s:%s",
 822                                    ref->name, sha1_to_hex(ref->old_sha1_expect));
 823                        string_list_append(&cas_options, strbuf_detach(&cas, NULL));
 824                }
 825        }
 826        if (buf.len == 0) {
 827                string_list_clear(&cas_options, 0);
 828                return 0;
 829        }
 830
 831        for_each_string_list_item(cas_option, &cas_options)
 832                set_helper_option(transport, "cas", cas_option->string);
 833
 834        if (flags & TRANSPORT_PUSH_DRY_RUN) {
 835                if (set_helper_option(transport, "dry-run", "true") != 0)
 836                        die("helper %s does not support dry-run", data->name);
 837        } else if (flags & TRANSPORT_PUSH_CERT) {
 838                if (set_helper_option(transport, TRANS_OPT_PUSH_CERT, "true") != 0)
 839                        die("helper %s does not support --signed", data->name);
 840        }
 841
 842        strbuf_addch(&buf, '\n');
 843        sendline(data, &buf);
 844        strbuf_release(&buf);
 845
 846        return push_update_refs_status(data, remote_refs, flags);
 847}
 848
 849static int push_refs_with_export(struct transport *transport,
 850                struct ref *remote_refs, int flags)
 851{
 852        struct ref *ref;
 853        struct child_process *helper, exporter;
 854        struct helper_data *data = transport->data;
 855        struct string_list revlist_args = STRING_LIST_INIT_DUP;
 856        struct strbuf buf = STRBUF_INIT;
 857
 858        if (!data->refspecs)
 859                die("remote-helper doesn't support push; refspec needed");
 860
 861        if (flags & TRANSPORT_PUSH_DRY_RUN) {
 862                if (set_helper_option(transport, "dry-run", "true") != 0)
 863                        die("helper %s does not support dry-run", data->name);
 864        } else if (flags & TRANSPORT_PUSH_CERT) {
 865                if (set_helper_option(transport, TRANS_OPT_PUSH_CERT, "true") != 0)
 866                        die("helper %s does not support --signed", data->name);
 867        }
 868
 869        if (flags & TRANSPORT_PUSH_FORCE) {
 870                if (set_helper_option(transport, "force", "true") != 0)
 871                        warning("helper %s does not support 'force'", data->name);
 872        }
 873
 874        helper = get_helper(transport);
 875
 876        write_constant(helper->in, "export\n");
 877
 878        for (ref = remote_refs; ref; ref = ref->next) {
 879                char *private;
 880                unsigned char sha1[20];
 881
 882                private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
 883                if (private && !get_sha1(private, sha1)) {
 884                        strbuf_addf(&buf, "^%s", private);
 885                        string_list_append(&revlist_args, strbuf_detach(&buf, NULL));
 886                        hashcpy(ref->old_sha1, sha1);
 887                }
 888                free(private);
 889
 890                if (ref->peer_ref) {
 891                        if (strcmp(ref->name, ref->peer_ref->name)) {
 892                                if (!ref->deletion) {
 893                                        const char *name;
 894                                        int flag;
 895
 896                                        /* Follow symbolic refs (mainly for HEAD). */
 897                                        name = resolve_ref_unsafe(
 898                                                 ref->peer_ref->name,
 899                                                 RESOLVE_REF_READING,
 900                                                 sha1, &flag);
 901                                        if (!name || !(flag & REF_ISSYMREF))
 902                                                name = ref->peer_ref->name;
 903
 904                                        strbuf_addf(&buf, "%s:%s", name, ref->name);
 905                                } else
 906                                        strbuf_addf(&buf, ":%s", ref->name);
 907
 908                                string_list_append(&revlist_args, "--refspec");
 909                                string_list_append(&revlist_args, buf.buf);
 910                                strbuf_release(&buf);
 911                        }
 912                        if (!ref->deletion)
 913                                string_list_append(&revlist_args, ref->peer_ref->name);
 914                }
 915        }
 916
 917        if (get_exporter(transport, &exporter, &revlist_args))
 918                die("Couldn't run fast-export");
 919
 920        string_list_clear(&revlist_args, 1);
 921
 922        if (finish_command(&exporter))
 923                die("Error while running fast-export");
 924        if (push_update_refs_status(data, remote_refs, flags))
 925                return 1;
 926
 927        if (data->export_marks) {
 928                strbuf_addf(&buf, "%s.tmp", data->export_marks);
 929                rename(buf.buf, data->export_marks);
 930                strbuf_release(&buf);
 931        }
 932
 933        return 0;
 934}
 935
 936static int push_refs(struct transport *transport,
 937                struct ref *remote_refs, int flags)
 938{
 939        struct helper_data *data = transport->data;
 940
 941        if (process_connect(transport, 1)) {
 942                do_take_over(transport);
 943                return transport->push_refs(transport, remote_refs, flags);
 944        }
 945
 946        if (!remote_refs) {
 947                fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
 948                        "Perhaps you should specify a branch such as 'master'.\n");
 949                return 0;
 950        }
 951
 952        if (data->push)
 953                return push_refs_with_push(transport, remote_refs, flags);
 954
 955        if (data->export)
 956                return push_refs_with_export(transport, remote_refs, flags);
 957
 958        return -1;
 959}
 960
 961
 962static int has_attribute(const char *attrs, const char *attr) {
 963        int len;
 964        if (!attrs)
 965                return 0;
 966
 967        len = strlen(attr);
 968        for (;;) {
 969                const char *space = strchrnul(attrs, ' ');
 970                if (len == space - attrs && !strncmp(attrs, attr, len))
 971                        return 1;
 972                if (!*space)
 973                        return 0;
 974                attrs = space + 1;
 975        }
 976}
 977
 978static struct ref *get_refs_list(struct transport *transport, int for_push)
 979{
 980        struct helper_data *data = transport->data;
 981        struct child_process *helper;
 982        struct ref *ret = NULL;
 983        struct ref **tail = &ret;
 984        struct ref *posn;
 985        struct strbuf buf = STRBUF_INIT;
 986
 987        helper = get_helper(transport);
 988
 989        if (process_connect(transport, for_push)) {
 990                do_take_over(transport);
 991                return transport->get_refs_list(transport, for_push);
 992        }
 993
 994        if (data->push && for_push)
 995                write_str_in_full(helper->in, "list for-push\n");
 996        else
 997                write_str_in_full(helper->in, "list\n");
 998
 999        while (1) {
1000                char *eov, *eon;
1001                if (recvline(data, &buf))
1002                        exit(128);
1003
1004                if (!*buf.buf)
1005                        break;
1006
1007                eov = strchr(buf.buf, ' ');
1008                if (!eov)
1009                        die("Malformed response in ref list: %s", buf.buf);
1010                eon = strchr(eov + 1, ' ');
1011                *eov = '\0';
1012                if (eon)
1013                        *eon = '\0';
1014                *tail = alloc_ref(eov + 1);
1015                if (buf.buf[0] == '@')
1016                        (*tail)->symref = xstrdup(buf.buf + 1);
1017                else if (buf.buf[0] != '?')
1018                        get_sha1_hex(buf.buf, (*tail)->old_sha1);
1019                if (eon) {
1020                        if (has_attribute(eon + 1, "unchanged")) {
1021                                (*tail)->status |= REF_STATUS_UPTODATE;
1022                                read_ref((*tail)->name, (*tail)->old_sha1);
1023                        }
1024                }
1025                tail = &((*tail)->next);
1026        }
1027        if (debug)
1028                fprintf(stderr, "Debug: Read ref listing.\n");
1029        strbuf_release(&buf);
1030
1031        for (posn = ret; posn; posn = posn->next)
1032                resolve_remote_symref(posn, ret);
1033
1034        return ret;
1035}
1036
1037int transport_helper_init(struct transport *transport, const char *name)
1038{
1039        struct helper_data *data = xcalloc(1, sizeof(*data));
1040        data->name = name;
1041
1042        if (getenv("GIT_TRANSPORT_HELPER_DEBUG"))
1043                debug = 1;
1044
1045        transport->data = data;
1046        transport->set_option = set_helper_option;
1047        transport->get_refs_list = get_refs_list;
1048        transport->fetch = fetch;
1049        transport->push_refs = push_refs;
1050        transport->disconnect = release_helper;
1051        transport->connect = connect_helper;
1052        transport->smart_options = &(data->transport_options);
1053        return 0;
1054}
1055
1056/*
1057 * Linux pipes can buffer 65536 bytes at once (and most platforms can
1058 * buffer less), so attempt reads and writes with up to that size.
1059 */
1060#define BUFFERSIZE 65536
1061/* This should be enough to hold debugging message. */
1062#define PBUFFERSIZE 8192
1063
1064/* Print bidirectional transfer loop debug message. */
1065__attribute__((format (printf, 1, 2)))
1066static void transfer_debug(const char *fmt, ...)
1067{
1068        va_list args;
1069        char msgbuf[PBUFFERSIZE];
1070        static int debug_enabled = -1;
1071
1072        if (debug_enabled < 0)
1073                debug_enabled = getenv("GIT_TRANSLOOP_DEBUG") ? 1 : 0;
1074        if (!debug_enabled)
1075                return;
1076
1077        va_start(args, fmt);
1078        vsnprintf(msgbuf, PBUFFERSIZE, fmt, args);
1079        va_end(args);
1080        fprintf(stderr, "Transfer loop debugging: %s\n", msgbuf);
1081}
1082
1083/* Stream state: More data may be coming in this direction. */
1084#define SSTATE_TRANSFERING 0
1085/*
1086 * Stream state: No more data coming in this direction, flushing rest of
1087 * data.
1088 */
1089#define SSTATE_FLUSHING 1
1090/* Stream state: Transfer in this direction finished. */
1091#define SSTATE_FINISHED 2
1092
1093#define STATE_NEEDS_READING(state) ((state) <= SSTATE_TRANSFERING)
1094#define STATE_NEEDS_WRITING(state) ((state) <= SSTATE_FLUSHING)
1095#define STATE_NEEDS_CLOSING(state) ((state) == SSTATE_FLUSHING)
1096
1097/* Unidirectional transfer. */
1098struct unidirectional_transfer {
1099        /* Source */
1100        int src;
1101        /* Destination */
1102        int dest;
1103        /* Is source socket? */
1104        int src_is_sock;
1105        /* Is destination socket? */
1106        int dest_is_sock;
1107        /* Transfer state (TRANSFERRING/FLUSHING/FINISHED) */
1108        int state;
1109        /* Buffer. */
1110        char buf[BUFFERSIZE];
1111        /* Buffer used. */
1112        size_t bufuse;
1113        /* Name of source. */
1114        const char *src_name;
1115        /* Name of destination. */
1116        const char *dest_name;
1117};
1118
1119/* Closes the target (for writing) if transfer has finished. */
1120static void udt_close_if_finished(struct unidirectional_transfer *t)
1121{
1122        if (STATE_NEEDS_CLOSING(t->state) && !t->bufuse) {
1123                t->state = SSTATE_FINISHED;
1124                if (t->dest_is_sock)
1125                        shutdown(t->dest, SHUT_WR);
1126                else
1127                        close(t->dest);
1128                transfer_debug("Closed %s.", t->dest_name);
1129        }
1130}
1131
1132/*
1133 * Tries to read read data from source into buffer. If buffer is full,
1134 * no data is read. Returns 0 on success, -1 on error.
1135 */
1136static int udt_do_read(struct unidirectional_transfer *t)
1137{
1138        ssize_t bytes;
1139
1140        if (t->bufuse == BUFFERSIZE)
1141                return 0;       /* No space for more. */
1142
1143        transfer_debug("%s is readable", t->src_name);
1144        bytes = read(t->src, t->buf + t->bufuse, BUFFERSIZE - t->bufuse);
1145        if (bytes < 0 && errno != EWOULDBLOCK && errno != EAGAIN &&
1146                errno != EINTR) {
1147                error("read(%s) failed: %s", t->src_name, strerror(errno));
1148                return -1;
1149        } else if (bytes == 0) {
1150                transfer_debug("%s EOF (with %i bytes in buffer)",
1151                        t->src_name, (int)t->bufuse);
1152                t->state = SSTATE_FLUSHING;
1153        } else if (bytes > 0) {
1154                t->bufuse += bytes;
1155                transfer_debug("Read %i bytes from %s (buffer now at %i)",
1156                        (int)bytes, t->src_name, (int)t->bufuse);
1157        }
1158        return 0;
1159}
1160
1161/* Tries to write data from buffer into destination. If buffer is empty,
1162 * no data is written. Returns 0 on success, -1 on error.
1163 */
1164static int udt_do_write(struct unidirectional_transfer *t)
1165{
1166        ssize_t bytes;
1167
1168        if (t->bufuse == 0)
1169                return 0;       /* Nothing to write. */
1170
1171        transfer_debug("%s is writable", t->dest_name);
1172        bytes = xwrite(t->dest, t->buf, t->bufuse);
1173        if (bytes < 0 && errno != EWOULDBLOCK) {
1174                error("write(%s) failed: %s", t->dest_name, strerror(errno));
1175                return -1;
1176        } else if (bytes > 0) {
1177                t->bufuse -= bytes;
1178                if (t->bufuse)
1179                        memmove(t->buf, t->buf + bytes, t->bufuse);
1180                transfer_debug("Wrote %i bytes to %s (buffer now at %i)",
1181                        (int)bytes, t->dest_name, (int)t->bufuse);
1182        }
1183        return 0;
1184}
1185
1186
1187/* State of bidirectional transfer loop. */
1188struct bidirectional_transfer_state {
1189        /* Direction from program to git. */
1190        struct unidirectional_transfer ptg;
1191        /* Direction from git to program. */
1192        struct unidirectional_transfer gtp;
1193};
1194
1195static void *udt_copy_task_routine(void *udt)
1196{
1197        struct unidirectional_transfer *t = (struct unidirectional_transfer *)udt;
1198        while (t->state != SSTATE_FINISHED) {
1199                if (STATE_NEEDS_READING(t->state))
1200                        if (udt_do_read(t))
1201                                return NULL;
1202                if (STATE_NEEDS_WRITING(t->state))
1203                        if (udt_do_write(t))
1204                                return NULL;
1205                if (STATE_NEEDS_CLOSING(t->state))
1206                        udt_close_if_finished(t);
1207        }
1208        return udt;     /* Just some non-NULL value. */
1209}
1210
1211#ifndef NO_PTHREADS
1212
1213/*
1214 * Join thread, with appropriate errors on failure. Name is name for the
1215 * thread (for error messages). Returns 0 on success, 1 on failure.
1216 */
1217static int tloop_join(pthread_t thread, const char *name)
1218{
1219        int err;
1220        void *tret;
1221        err = pthread_join(thread, &tret);
1222        if (!tret) {
1223                error("%s thread failed", name);
1224                return 1;
1225        }
1226        if (err) {
1227                error("%s thread failed to join: %s", name, strerror(err));
1228                return 1;
1229        }
1230        return 0;
1231}
1232
1233/*
1234 * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1235 * -1 on failure.
1236 */
1237static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1238{
1239        pthread_t gtp_thread;
1240        pthread_t ptg_thread;
1241        int err;
1242        int ret = 0;
1243        err = pthread_create(&gtp_thread, NULL, udt_copy_task_routine,
1244                &s->gtp);
1245        if (err)
1246                die("Can't start thread for copying data: %s", strerror(err));
1247        err = pthread_create(&ptg_thread, NULL, udt_copy_task_routine,
1248                &s->ptg);
1249        if (err)
1250                die("Can't start thread for copying data: %s", strerror(err));
1251
1252        ret |= tloop_join(gtp_thread, "Git to program copy");
1253        ret |= tloop_join(ptg_thread, "Program to git copy");
1254        return ret;
1255}
1256#else
1257
1258/* Close the source and target (for writing) for transfer. */
1259static void udt_kill_transfer(struct unidirectional_transfer *t)
1260{
1261        t->state = SSTATE_FINISHED;
1262        /*
1263         * Socket read end left open isn't a disaster if nobody
1264         * attempts to read from it (mingw compat headers do not
1265         * have SHUT_RD)...
1266         *
1267         * We can't fully close the socket since otherwise gtp
1268         * task would first close the socket it sends data to
1269         * while closing the ptg file descriptors.
1270         */
1271        if (!t->src_is_sock)
1272                close(t->src);
1273        if (t->dest_is_sock)
1274                shutdown(t->dest, SHUT_WR);
1275        else
1276                close(t->dest);
1277}
1278
1279/*
1280 * Join process, with appropriate errors on failure. Name is name for the
1281 * process (for error messages). Returns 0 on success, 1 on failure.
1282 */
1283static int tloop_join(pid_t pid, const char *name)
1284{
1285        int tret;
1286        if (waitpid(pid, &tret, 0) < 0) {
1287                error("%s process failed to wait: %s", name, strerror(errno));
1288                return 1;
1289        }
1290        if (!WIFEXITED(tret) || WEXITSTATUS(tret)) {
1291                error("%s process failed", name);
1292                return 1;
1293        }
1294        return 0;
1295}
1296
1297/*
1298 * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1299 * -1 on failure.
1300 */
1301static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1302{
1303        pid_t pid1, pid2;
1304        int ret = 0;
1305
1306        /* Fork thread #1: git to program. */
1307        pid1 = fork();
1308        if (pid1 < 0)
1309                die_errno("Can't start thread for copying data");
1310        else if (pid1 == 0) {
1311                udt_kill_transfer(&s->ptg);
1312                exit(udt_copy_task_routine(&s->gtp) ? 0 : 1);
1313        }
1314
1315        /* Fork thread #2: program to git. */
1316        pid2 = fork();
1317        if (pid2 < 0)
1318                die_errno("Can't start thread for copying data");
1319        else if (pid2 == 0) {
1320                udt_kill_transfer(&s->gtp);
1321                exit(udt_copy_task_routine(&s->ptg) ? 0 : 1);
1322        }
1323
1324        /*
1325         * Close both streams in parent as to not interfere with
1326         * end of file detection and wait for both tasks to finish.
1327         */
1328        udt_kill_transfer(&s->gtp);
1329        udt_kill_transfer(&s->ptg);
1330        ret |= tloop_join(pid1, "Git to program copy");
1331        ret |= tloop_join(pid2, "Program to git copy");
1332        return ret;
1333}
1334#endif
1335
1336/*
1337 * Copies data from stdin to output and from input to stdout simultaneously.
1338 * Additionally filtering through given filter. If filter is NULL, uses
1339 * identity filter.
1340 */
1341int bidirectional_transfer_loop(int input, int output)
1342{
1343        struct bidirectional_transfer_state state;
1344
1345        /* Fill the state fields. */
1346        state.ptg.src = input;
1347        state.ptg.dest = 1;
1348        state.ptg.src_is_sock = (input == output);
1349        state.ptg.dest_is_sock = 0;
1350        state.ptg.state = SSTATE_TRANSFERING;
1351        state.ptg.bufuse = 0;
1352        state.ptg.src_name = "remote input";
1353        state.ptg.dest_name = "stdout";
1354
1355        state.gtp.src = 0;
1356        state.gtp.dest = output;
1357        state.gtp.src_is_sock = 0;
1358        state.gtp.dest_is_sock = (input == output);
1359        state.gtp.state = SSTATE_TRANSFERING;
1360        state.gtp.bufuse = 0;
1361        state.gtp.src_name = "stdin";
1362        state.gtp.dest_name = "remote output";
1363
1364        return tloop_spawnwait_tasks(&state);
1365}