fefd34f134a3f3b634fe01e6d68a0ddebd989dd1
   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
  16static int debug;
  17
  18struct helper_data {
  19        const char *name;
  20        struct child_process *helper;
  21        FILE *out;
  22        unsigned fetch : 1,
  23                import : 1,
  24                bidi_import : 1,
  25                export : 1,
  26                option : 1,
  27                push : 1,
  28                connect : 1,
  29                signed_tags : 1,
  30                check_connectivity : 1,
  31                no_disconnect_req : 1,
  32                no_private_update : 1;
  33        char *export_marks;
  34        char *import_marks;
  35        /* These go from remote name (as in "list") to private name */
  36        struct refspec *refspecs;
  37        int refspec_nr;
  38        /* Transport options for fetch-pack/send-pack (should one of
  39         * those be invoked).
  40         */
  41        struct git_transport_options transport_options;
  42};
  43
  44static void sendline(struct helper_data *helper, struct strbuf *buffer)
  45{
  46        if (debug)
  47                fprintf(stderr, "Debug: Remote helper: -> %s", buffer->buf);
  48        if (write_in_full(helper->helper->in, buffer->buf, buffer->len)
  49                != buffer->len)
  50                die_errno("Full write to remote helper failed");
  51}
  52
  53static int recvline_fh(FILE *helper, struct strbuf *buffer, const char *name)
  54{
  55        strbuf_reset(buffer);
  56        if (debug)
  57                fprintf(stderr, "Debug: Remote helper: Waiting...\n");
  58        if (strbuf_getline(buffer, helper, '\n') == EOF) {
  59                if (debug)
  60                        fprintf(stderr, "Debug: Remote helper quit.\n");
  61                return 1;
  62        }
  63
  64        if (debug)
  65                fprintf(stderr, "Debug: Remote helper: <- %s\n", buffer->buf);
  66        return 0;
  67}
  68
  69static int recvline(struct helper_data *helper, struct strbuf *buffer)
  70{
  71        return recvline_fh(helper->out, buffer, helper->name);
  72}
  73
  74static void write_constant(int fd, const char *str)
  75{
  76        if (debug)
  77                fprintf(stderr, "Debug: Remote helper: -> %s", str);
  78        if (write_in_full(fd, str, strlen(str)) != strlen(str))
  79                die_errno("Full write to remote helper failed");
  80}
  81
  82static const char *remove_ext_force(const char *url)
  83{
  84        if (url) {
  85                const char *colon = strchr(url, ':');
  86                if (colon && colon[1] == ':')
  87                        return colon + 2;
  88        }
  89        return url;
  90}
  91
  92static void do_take_over(struct transport *transport)
  93{
  94        struct helper_data *data;
  95        data = (struct helper_data *)transport->data;
  96        transport_take_over(transport, data->helper);
  97        fclose(data->out);
  98        free(data);
  99}
 100
 101static struct child_process *get_helper(struct transport *transport)
 102{
 103        struct helper_data *data = transport->data;
 104        struct strbuf buf = STRBUF_INIT;
 105        struct child_process *helper;
 106        const char **refspecs = NULL;
 107        int refspec_nr = 0;
 108        int refspec_alloc = 0;
 109        int duped;
 110        int code;
 111        char git_dir_buf[sizeof(GIT_DIR_ENVIRONMENT) + PATH_MAX + 1];
 112        const char *helper_env[] = {
 113                git_dir_buf,
 114                NULL
 115        };
 116
 117
 118        if (data->helper)
 119                return data->helper;
 120
 121        helper = xcalloc(1, sizeof(*helper));
 122        helper->in = -1;
 123        helper->out = -1;
 124        helper->err = 0;
 125        argv_array_pushf(&helper->args, "git-remote-%s", data->name);
 126        argv_array_push(&helper->args, transport->remote->name);
 127        argv_array_push(&helper->args, remove_ext_force(transport->url));
 128        helper->git_cmd = 0;
 129        helper->silent_exec_failure = 1;
 130
 131        snprintf(git_dir_buf, sizeof(git_dir_buf), "%s=%s", GIT_DIR_ENVIRONMENT, get_git_dir());
 132        helper->env = helper_env;
 133
 134        code = start_command(helper);
 135        if (code < 0 && errno == ENOENT)
 136                die("Unable to find remote helper for '%s'", data->name);
 137        else if (code != 0)
 138                exit(code);
 139
 140        data->helper = helper;
 141        data->no_disconnect_req = 0;
 142
 143        /*
 144         * Open the output as FILE* so strbuf_getline() can be used.
 145         * Do this with duped fd because fclose() will close the fd,
 146         * and stuff like taking over will require the fd to remain.
 147         */
 148        duped = dup(helper->out);
 149        if (duped < 0)
 150                die_errno("Can't dup helper output fd");
 151        data->out = xfdopen(duped, "r");
 152
 153        write_constant(helper->in, "capabilities\n");
 154
 155        while (1) {
 156                const char *capname;
 157                int mandatory = 0;
 158                if (recvline(data, &buf))
 159                        exit(128);
 160
 161                if (!*buf.buf)
 162                        break;
 163
 164                if (*buf.buf == '*') {
 165                        capname = buf.buf + 1;
 166                        mandatory = 1;
 167                } else
 168                        capname = buf.buf;
 169
 170                if (debug)
 171                        fprintf(stderr, "Debug: Got cap %s\n", capname);
 172                if (!strcmp(capname, "fetch"))
 173                        data->fetch = 1;
 174                else if (!strcmp(capname, "option"))
 175                        data->option = 1;
 176                else if (!strcmp(capname, "push"))
 177                        data->push = 1;
 178                else if (!strcmp(capname, "import"))
 179                        data->import = 1;
 180                else if (!strcmp(capname, "bidi-import"))
 181                        data->bidi_import = 1;
 182                else if (!strcmp(capname, "export"))
 183                        data->export = 1;
 184                else if (!strcmp(capname, "check-connectivity"))
 185                        data->check_connectivity = 1;
 186                else if (!data->refspecs && starts_with(capname, "refspec ")) {
 187                        ALLOC_GROW(refspecs,
 188                                   refspec_nr + 1,
 189                                   refspec_alloc);
 190                        refspecs[refspec_nr++] = xstrdup(capname + strlen("refspec "));
 191                } else if (!strcmp(capname, "connect")) {
 192                        data->connect = 1;
 193                } else if (!strcmp(capname, "signed-tags")) {
 194                        data->signed_tags = 1;
 195                } else if (starts_with(capname, "export-marks ")) {
 196                        data->export_marks = xstrdup(capname + strlen("export-marks "));
 197                } else if (starts_with(capname, "import-marks")) {
 198                        data->import_marks = xstrdup(capname + strlen("import-marks "));
 199                } else if (starts_with(capname, "no-private-update")) {
 200                        data->no_private_update = 1;
 201                } else if (mandatory) {
 202                        die("Unknown mandatory capability %s. This remote "
 203                            "helper probably needs newer version of Git.",
 204                            capname);
 205                }
 206        }
 207        if (refspecs) {
 208                int i;
 209                data->refspec_nr = refspec_nr;
 210                data->refspecs = parse_fetch_refspec(refspec_nr, refspecs);
 211                for (i = 0; i < refspec_nr; i++)
 212                        free((char *)refspecs[i]);
 213                free(refspecs);
 214        } else if (data->import || data->bidi_import || data->export) {
 215                warning("This remote helper should implement refspec capability.");
 216        }
 217        strbuf_release(&buf);
 218        if (debug)
 219                fprintf(stderr, "Debug: Capabilities complete.\n");
 220        return data->helper;
 221}
 222
 223static int disconnect_helper(struct transport *transport)
 224{
 225        struct helper_data *data = transport->data;
 226        int res = 0;
 227
 228        if (data->helper) {
 229                if (debug)
 230                        fprintf(stderr, "Debug: Disconnecting.\n");
 231                if (!data->no_disconnect_req) {
 232                        /*
 233                         * Ignore write errors; there's nothing we can do,
 234                         * since we're about to close the pipe anyway. And the
 235                         * most likely error is EPIPE due to the helper dying
 236                         * to report an error itself.
 237                         */
 238                        sigchain_push(SIGPIPE, SIG_IGN);
 239                        xwrite(data->helper->in, "\n", 1);
 240                        sigchain_pop(SIGPIPE);
 241                }
 242                close(data->helper->in);
 243                close(data->helper->out);
 244                fclose(data->out);
 245                res = finish_command(data->helper);
 246                free(data->helper);
 247                data->helper = NULL;
 248        }
 249        return res;
 250}
 251
 252static const char *unsupported_options[] = {
 253        TRANS_OPT_UPLOADPACK,
 254        TRANS_OPT_RECEIVEPACK,
 255        TRANS_OPT_THIN,
 256        TRANS_OPT_KEEP
 257        };
 258
 259static const char *boolean_options[] = {
 260        TRANS_OPT_THIN,
 261        TRANS_OPT_KEEP,
 262        TRANS_OPT_FOLLOWTAGS
 263        };
 264
 265static int set_helper_option(struct transport *transport,
 266                          const char *name, const char *value)
 267{
 268        struct helper_data *data = transport->data;
 269        struct strbuf buf = STRBUF_INIT;
 270        int i, ret, is_bool = 0;
 271
 272        get_helper(transport);
 273
 274        if (!data->option)
 275                return 1;
 276
 277        for (i = 0; i < ARRAY_SIZE(unsupported_options); i++) {
 278                if (!strcmp(name, unsupported_options[i]))
 279                        return 1;
 280        }
 281
 282        for (i = 0; i < ARRAY_SIZE(boolean_options); i++) {
 283                if (!strcmp(name, boolean_options[i])) {
 284                        is_bool = 1;
 285                        break;
 286                }
 287        }
 288
 289        strbuf_addf(&buf, "option %s ", name);
 290        if (is_bool)
 291                strbuf_addstr(&buf, value ? "true" : "false");
 292        else
 293                quote_c_style(value, &buf, NULL, 0);
 294        strbuf_addch(&buf, '\n');
 295
 296        sendline(data, &buf);
 297        if (recvline(data, &buf))
 298                exit(128);
 299
 300        if (!strcmp(buf.buf, "ok"))
 301                ret = 0;
 302        else if (starts_with(buf.buf, "error")) {
 303                ret = -1;
 304        } else if (!strcmp(buf.buf, "unsupported"))
 305                ret = 1;
 306        else {
 307                warning("%s unexpectedly said: '%s'", data->name, buf.buf);
 308                ret = 1;
 309        }
 310        strbuf_release(&buf);
 311        return ret;
 312}
 313
 314static void standard_options(struct transport *t)
 315{
 316        char buf[16];
 317        int n;
 318        int v = t->verbose;
 319
 320        set_helper_option(t, "progress", t->progress ? "true" : "false");
 321
 322        n = snprintf(buf, sizeof(buf), "%d", v + 1);
 323        if (n >= sizeof(buf))
 324                die("impossibly large verbosity value");
 325        set_helper_option(t, "verbosity", buf);
 326}
 327
 328static int release_helper(struct transport *transport)
 329{
 330        int res = 0;
 331        struct helper_data *data = transport->data;
 332        free_refspec(data->refspec_nr, data->refspecs);
 333        data->refspecs = NULL;
 334        res = disconnect_helper(transport);
 335        free(transport->data);
 336        return res;
 337}
 338
 339static int fetch_with_fetch(struct transport *transport,
 340                            int nr_heads, struct ref **to_fetch)
 341{
 342        struct helper_data *data = transport->data;
 343        int i;
 344        struct strbuf buf = STRBUF_INIT;
 345
 346        standard_options(transport);
 347        if (data->check_connectivity &&
 348            data->transport_options.check_self_contained_and_connected)
 349                set_helper_option(transport, "check-connectivity", "true");
 350
 351        if (transport->cloning)
 352                set_helper_option(transport, "cloning", "true");
 353
 354        if (data->transport_options.update_shallow)
 355                set_helper_option(transport, "update-shallow", "true");
 356
 357        for (i = 0; i < nr_heads; i++) {
 358                const struct ref *posn = to_fetch[i];
 359                if (posn->status & REF_STATUS_UPTODATE)
 360                        continue;
 361
 362                strbuf_addf(&buf, "fetch %s %s\n",
 363                            sha1_to_hex(posn->old_sha1), posn->name);
 364        }
 365
 366        strbuf_addch(&buf, '\n');
 367        sendline(data, &buf);
 368
 369        while (1) {
 370                if (recvline(data, &buf))
 371                        exit(128);
 372
 373                if (starts_with(buf.buf, "lock ")) {
 374                        const char *name = buf.buf + 5;
 375                        if (transport->pack_lockfile)
 376                                warning("%s also locked %s", data->name, name);
 377                        else
 378                                transport->pack_lockfile = xstrdup(name);
 379                }
 380                else if (data->check_connectivity &&
 381                         data->transport_options.check_self_contained_and_connected &&
 382                         !strcmp(buf.buf, "connectivity-ok"))
 383                        data->transport_options.self_contained_and_connected = 1;
 384                else if (!buf.len)
 385                        break;
 386                else
 387                        warning("%s unexpectedly said: '%s'", data->name, buf.buf);
 388        }
 389        strbuf_release(&buf);
 390        return 0;
 391}
 392
 393static int get_importer(struct transport *transport, struct child_process *fastimport)
 394{
 395        struct child_process *helper = get_helper(transport);
 396        struct helper_data *data = transport->data;
 397        struct argv_array argv = ARGV_ARRAY_INIT;
 398        int cat_blob_fd, code;
 399        memset(fastimport, 0, sizeof(*fastimport));
 400        fastimport->in = helper->out;
 401        argv_array_push(&argv, "fast-import");
 402        argv_array_push(&argv, debug ? "--stats" : "--quiet");
 403
 404        if (data->bidi_import) {
 405                cat_blob_fd = xdup(helper->in);
 406                argv_array_pushf(&argv, "--cat-blob-fd=%d", cat_blob_fd);
 407        }
 408        fastimport->argv = argv.argv;
 409        fastimport->git_cmd = 1;
 410
 411        code = start_command(fastimport);
 412        return code;
 413}
 414
 415static int get_exporter(struct transport *transport,
 416                        struct child_process *fastexport,
 417                        struct string_list *revlist_args)
 418{
 419        struct helper_data *data = transport->data;
 420        struct child_process *helper = get_helper(transport);
 421        int argc = 0, i;
 422        struct strbuf tmp = STRBUF_INIT;
 423
 424        memset(fastexport, 0, sizeof(*fastexport));
 425
 426        /* we need to duplicate helper->in because we want to use it after
 427         * fastexport is done with it. */
 428        fastexport->out = dup(helper->in);
 429        fastexport->argv = xcalloc(6 + revlist_args->nr, sizeof(*fastexport->argv));
 430        fastexport->argv[argc++] = "fast-export";
 431        fastexport->argv[argc++] = "--use-done-feature";
 432        fastexport->argv[argc++] = data->signed_tags ?
 433                "--signed-tags=verbatim" : "--signed-tags=warn-strip";
 434        if (data->export_marks) {
 435                strbuf_addf(&tmp, "--export-marks=%s.tmp", data->export_marks);
 436                fastexport->argv[argc++] = strbuf_detach(&tmp, NULL);
 437        }
 438        if (data->import_marks) {
 439                strbuf_addf(&tmp, "--import-marks=%s", data->import_marks);
 440                fastexport->argv[argc++] = strbuf_detach(&tmp, NULL);
 441        }
 442
 443        for (i = 0; i < revlist_args->nr; i++)
 444                fastexport->argv[argc++] = revlist_args->items[i].string;
 445
 446        fastexport->git_cmd = 1;
 447        return start_command(fastexport);
 448}
 449
 450static int fetch_with_import(struct transport *transport,
 451                             int nr_heads, struct ref **to_fetch)
 452{
 453        struct child_process fastimport;
 454        struct helper_data *data = transport->data;
 455        int i;
 456        struct ref *posn;
 457        struct strbuf buf = STRBUF_INIT;
 458
 459        get_helper(transport);
 460
 461        if (get_importer(transport, &fastimport))
 462                die("Couldn't run fast-import");
 463
 464        for (i = 0; i < nr_heads; i++) {
 465                posn = to_fetch[i];
 466                if (posn->status & REF_STATUS_UPTODATE)
 467                        continue;
 468
 469                strbuf_addf(&buf, "import %s\n", posn->name);
 470                sendline(data, &buf);
 471                strbuf_reset(&buf);
 472        }
 473
 474        write_constant(data->helper->in, "\n");
 475        /*
 476         * remote-helpers that advertise the bidi-import capability are required to
 477         * buffer the complete batch of import commands until this newline before
 478         * sending data to fast-import.
 479         * These helpers read back data from fast-import on their stdin, which could
 480         * be mixed with import commands, otherwise.
 481         */
 482
 483        if (finish_command(&fastimport))
 484                die("Error while running fast-import");
 485        argv_array_free_detached(fastimport.argv);
 486
 487        /*
 488         * The fast-import stream of a remote helper that advertises
 489         * the "refspec" capability writes to the refs named after the
 490         * right hand side of the first refspec matching each ref we
 491         * were fetching.
 492         *
 493         * (If no "refspec" capability was specified, for historical
 494         * reasons we default to the equivalent of *:*.)
 495         *
 496         * Store the result in to_fetch[i].old_sha1.  Callers such
 497         * as "git fetch" can use the value to write feedback to the
 498         * terminal, populate FETCH_HEAD, and determine what new value
 499         * should be written to peer_ref if the update is a
 500         * fast-forward or this is a forced update.
 501         */
 502        for (i = 0; i < nr_heads; i++) {
 503                char *private;
 504                posn = to_fetch[i];
 505                if (posn->status & REF_STATUS_UPTODATE)
 506                        continue;
 507                if (data->refspecs)
 508                        private = apply_refspecs(data->refspecs, data->refspec_nr, posn->name);
 509                else
 510                        private = xstrdup(posn->name);
 511                if (private) {
 512                        read_ref(private, posn->old_sha1);
 513                        free(private);
 514                }
 515        }
 516        strbuf_release(&buf);
 517        return 0;
 518}
 519
 520static int process_connect_service(struct transport *transport,
 521                                   const char *name, const char *exec)
 522{
 523        struct helper_data *data = transport->data;
 524        struct strbuf cmdbuf = STRBUF_INIT;
 525        struct child_process *helper;
 526        int r, duped, ret = 0;
 527        FILE *input;
 528
 529        helper = get_helper(transport);
 530
 531        /*
 532         * Yes, dup the pipe another time, as we need unbuffered version
 533         * of input pipe as FILE*. fclose() closes the underlying fd and
 534         * stream buffering only can be changed before first I/O operation
 535         * on it.
 536         */
 537        duped = dup(helper->out);
 538        if (duped < 0)
 539                die_errno("Can't dup helper output fd");
 540        input = xfdopen(duped, "r");
 541        setvbuf(input, NULL, _IONBF, 0);
 542
 543        /*
 544         * Handle --upload-pack and friends. This is fire and forget...
 545         * just warn if it fails.
 546         */
 547        if (strcmp(name, exec)) {
 548                r = set_helper_option(transport, "servpath", exec);
 549                if (r > 0)
 550                        warning("Setting remote service path not supported by protocol.");
 551                else if (r < 0)
 552                        warning("Invalid remote service path.");
 553        }
 554
 555        if (data->connect)
 556                strbuf_addf(&cmdbuf, "connect %s\n", name);
 557        else
 558                goto exit;
 559
 560        sendline(data, &cmdbuf);
 561        if (recvline_fh(input, &cmdbuf, name))
 562                exit(128);
 563
 564        if (!strcmp(cmdbuf.buf, "")) {
 565                data->no_disconnect_req = 1;
 566                if (debug)
 567                        fprintf(stderr, "Debug: Smart transport connection "
 568                                "ready.\n");
 569                ret = 1;
 570        } else if (!strcmp(cmdbuf.buf, "fallback")) {
 571                if (debug)
 572                        fprintf(stderr, "Debug: Falling back to dumb "
 573                                "transport.\n");
 574        } else
 575                die("Unknown response to connect: %s",
 576                        cmdbuf.buf);
 577
 578exit:
 579        fclose(input);
 580        return ret;
 581}
 582
 583static int process_connect(struct transport *transport,
 584                                     int for_push)
 585{
 586        struct helper_data *data = transport->data;
 587        const char *name;
 588        const char *exec;
 589
 590        name = for_push ? "git-receive-pack" : "git-upload-pack";
 591        if (for_push)
 592                exec = data->transport_options.receivepack;
 593        else
 594                exec = data->transport_options.uploadpack;
 595
 596        return process_connect_service(transport, name, exec);
 597}
 598
 599static int connect_helper(struct transport *transport, const char *name,
 600                   const char *exec, int fd[2])
 601{
 602        struct helper_data *data = transport->data;
 603
 604        /* Get_helper so connect is inited. */
 605        get_helper(transport);
 606        if (!data->connect)
 607                die("Operation not supported by protocol.");
 608
 609        if (!process_connect_service(transport, name, exec))
 610                die("Can't connect to subservice %s.", name);
 611
 612        fd[0] = data->helper->out;
 613        fd[1] = data->helper->in;
 614        return 0;
 615}
 616
 617static int fetch(struct transport *transport,
 618                 int nr_heads, struct ref **to_fetch)
 619{
 620        struct helper_data *data = transport->data;
 621        int i, count;
 622
 623        if (process_connect(transport, 0)) {
 624                do_take_over(transport);
 625                return transport->fetch(transport, nr_heads, to_fetch);
 626        }
 627
 628        count = 0;
 629        for (i = 0; i < nr_heads; i++)
 630                if (!(to_fetch[i]->status & REF_STATUS_UPTODATE))
 631                        count++;
 632
 633        if (!count)
 634                return 0;
 635
 636        if (data->fetch)
 637                return fetch_with_fetch(transport, nr_heads, to_fetch);
 638
 639        if (data->import)
 640                return fetch_with_import(transport, nr_heads, to_fetch);
 641
 642        return -1;
 643}
 644
 645static int push_update_ref_status(struct strbuf *buf,
 646                                   struct ref **ref,
 647                                   struct ref *remote_refs)
 648{
 649        char *refname, *msg;
 650        int status, forced = 0;
 651
 652        if (starts_with(buf->buf, "ok ")) {
 653                status = REF_STATUS_OK;
 654                refname = buf->buf + 3;
 655        } else if (starts_with(buf->buf, "error ")) {
 656                status = REF_STATUS_REMOTE_REJECT;
 657                refname = buf->buf + 6;
 658        } else
 659                die("expected ok/error, helper said '%s'", buf->buf);
 660
 661        msg = strchr(refname, ' ');
 662        if (msg) {
 663                struct strbuf msg_buf = STRBUF_INIT;
 664                const char *end;
 665
 666                *msg++ = '\0';
 667                if (!unquote_c_style(&msg_buf, msg, &end))
 668                        msg = strbuf_detach(&msg_buf, NULL);
 669                else
 670                        msg = xstrdup(msg);
 671                strbuf_release(&msg_buf);
 672
 673                if (!strcmp(msg, "no match")) {
 674                        status = REF_STATUS_NONE;
 675                        free(msg);
 676                        msg = NULL;
 677                }
 678                else if (!strcmp(msg, "up to date")) {
 679                        status = REF_STATUS_UPTODATE;
 680                        free(msg);
 681                        msg = NULL;
 682                }
 683                else if (!strcmp(msg, "non-fast forward")) {
 684                        status = REF_STATUS_REJECT_NONFASTFORWARD;
 685                        free(msg);
 686                        msg = NULL;
 687                }
 688                else if (!strcmp(msg, "already exists")) {
 689                        status = REF_STATUS_REJECT_ALREADY_EXISTS;
 690                        free(msg);
 691                        msg = NULL;
 692                }
 693                else if (!strcmp(msg, "fetch first")) {
 694                        status = REF_STATUS_REJECT_FETCH_FIRST;
 695                        free(msg);
 696                        msg = NULL;
 697                }
 698                else if (!strcmp(msg, "needs force")) {
 699                        status = REF_STATUS_REJECT_NEEDS_FORCE;
 700                        free(msg);
 701                        msg = NULL;
 702                }
 703                else if (!strcmp(msg, "stale info")) {
 704                        status = REF_STATUS_REJECT_STALE;
 705                        free(msg);
 706                        msg = NULL;
 707                }
 708                else if (!strcmp(msg, "forced update")) {
 709                        forced = 1;
 710                        free(msg);
 711                        msg = NULL;
 712                }
 713        }
 714
 715        if (*ref)
 716                *ref = find_ref_by_name(*ref, refname);
 717        if (!*ref)
 718                *ref = find_ref_by_name(remote_refs, refname);
 719        if (!*ref) {
 720                warning("helper reported unexpected status of %s", refname);
 721                return 1;
 722        }
 723
 724        if ((*ref)->status != REF_STATUS_NONE) {
 725                /*
 726                 * Earlier, the ref was marked not to be pushed, so ignore the ref
 727                 * status reported by the remote helper if the latter is 'no match'.
 728                 */
 729                if (status == REF_STATUS_NONE)
 730                        return 1;
 731        }
 732
 733        (*ref)->status = status;
 734        (*ref)->forced_update |= forced;
 735        (*ref)->remote_status = msg;
 736        return !(status == REF_STATUS_OK);
 737}
 738
 739static int push_update_refs_status(struct helper_data *data,
 740                                    struct ref *remote_refs,
 741                                    int flags)
 742{
 743        struct strbuf buf = STRBUF_INIT;
 744        struct ref *ref = remote_refs;
 745        int ret = 0;
 746
 747        for (;;) {
 748                char *private;
 749
 750                if (recvline(data, &buf)) {
 751                        ret = 1;
 752                        break;
 753                }
 754
 755                if (!buf.len)
 756                        break;
 757
 758                if (push_update_ref_status(&buf, &ref, remote_refs))
 759                        continue;
 760
 761                if (flags & TRANSPORT_PUSH_DRY_RUN || !data->refspecs || data->no_private_update)
 762                        continue;
 763
 764                /* propagate back the update to the remote namespace */
 765                private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
 766                if (!private)
 767                        continue;
 768                update_ref("update by helper", private, ref->new_sha1, NULL, 0, 0);
 769                free(private);
 770        }
 771        strbuf_release(&buf);
 772        return ret;
 773}
 774
 775static int push_refs_with_push(struct transport *transport,
 776                               struct ref *remote_refs, int flags)
 777{
 778        int force_all = flags & TRANSPORT_PUSH_FORCE;
 779        int mirror = flags & TRANSPORT_PUSH_MIRROR;
 780        struct helper_data *data = transport->data;
 781        struct strbuf buf = STRBUF_INIT;
 782        struct ref *ref;
 783        struct string_list cas_options = STRING_LIST_INIT_DUP;
 784        struct string_list_item *cas_option;
 785
 786        get_helper(transport);
 787        if (!data->push)
 788                return 1;
 789
 790        for (ref = remote_refs; ref; ref = ref->next) {
 791                if (!ref->peer_ref && !mirror)
 792                        continue;
 793
 794                /* Check for statuses set by set_ref_status_for_push() */
 795                switch (ref->status) {
 796                case REF_STATUS_REJECT_NONFASTFORWARD:
 797                case REF_STATUS_REJECT_STALE:
 798                case REF_STATUS_REJECT_ALREADY_EXISTS:
 799                case REF_STATUS_UPTODATE:
 800                        continue;
 801                default:
 802                        ; /* do nothing */
 803                }
 804
 805                if (force_all)
 806                        ref->force = 1;
 807
 808                strbuf_addstr(&buf, "push ");
 809                if (!ref->deletion) {
 810                        if (ref->force)
 811                                strbuf_addch(&buf, '+');
 812                        if (ref->peer_ref)
 813                                strbuf_addstr(&buf, ref->peer_ref->name);
 814                        else
 815                                strbuf_addstr(&buf, sha1_to_hex(ref->new_sha1));
 816                }
 817                strbuf_addch(&buf, ':');
 818                strbuf_addstr(&buf, ref->name);
 819                strbuf_addch(&buf, '\n');
 820
 821                /*
 822                 * The "--force-with-lease" options without explicit
 823                 * values to expect have already been expanded into
 824                 * the ref->old_sha1_expect[] field; we can ignore
 825                 * transport->smart_options->cas altogether and instead
 826                 * can enumerate them from the refs.
 827                 */
 828                if (ref->expect_old_sha1) {
 829                        struct strbuf cas = STRBUF_INIT;
 830                        strbuf_addf(&cas, "%s:%s",
 831                                    ref->name, sha1_to_hex(ref->old_sha1_expect));
 832                        string_list_append(&cas_options, strbuf_detach(&cas, NULL));
 833                }
 834        }
 835        if (buf.len == 0) {
 836                string_list_clear(&cas_options, 0);
 837                return 0;
 838        }
 839
 840        standard_options(transport);
 841        for_each_string_list_item(cas_option, &cas_options)
 842                set_helper_option(transport, "cas", cas_option->string);
 843
 844        if (flags & TRANSPORT_PUSH_DRY_RUN) {
 845                if (set_helper_option(transport, "dry-run", "true") != 0)
 846                        die("helper %s does not support dry-run", data->name);
 847        }
 848
 849        strbuf_addch(&buf, '\n');
 850        sendline(data, &buf);
 851        strbuf_release(&buf);
 852
 853        return push_update_refs_status(data, remote_refs, flags);
 854}
 855
 856static int push_refs_with_export(struct transport *transport,
 857                struct ref *remote_refs, int flags)
 858{
 859        struct ref *ref;
 860        struct child_process *helper, exporter;
 861        struct helper_data *data = transport->data;
 862        struct string_list revlist_args = STRING_LIST_INIT_NODUP;
 863        struct strbuf buf = STRBUF_INIT;
 864
 865        if (!data->refspecs)
 866                die("remote-helper doesn't support push; refspec needed");
 867
 868        if (flags & TRANSPORT_PUSH_DRY_RUN) {
 869                if (set_helper_option(transport, "dry-run", "true") != 0)
 870                        die("helper %s does not support dry-run", data->name);
 871        }
 872
 873        if (flags & TRANSPORT_PUSH_FORCE) {
 874                if (set_helper_option(transport, "force", "true") != 0)
 875                        warning("helper %s does not support 'force'", data->name);
 876        }
 877
 878        helper = get_helper(transport);
 879
 880        write_constant(helper->in, "export\n");
 881
 882        strbuf_reset(&buf);
 883
 884        for (ref = remote_refs; ref; ref = ref->next) {
 885                char *private;
 886                unsigned char sha1[20];
 887
 888                if (ref->deletion)
 889                        die("remote-helpers do not support ref deletion");
 890
 891                private = apply_refspecs(data->refspecs, data->refspec_nr, ref->name);
 892                if (private && !get_sha1(private, sha1)) {
 893                        strbuf_addf(&buf, "^%s", private);
 894                        string_list_append(&revlist_args, strbuf_detach(&buf, NULL));
 895                        hashcpy(ref->old_sha1, sha1);
 896                }
 897                free(private);
 898
 899                if (ref->peer_ref) {
 900                        if (strcmp(ref->peer_ref->name, ref->name))
 901                                die("remote-helpers do not support old:new syntax");
 902                        string_list_append(&revlist_args, ref->peer_ref->name);
 903                }
 904        }
 905
 906        if (get_exporter(transport, &exporter, &revlist_args))
 907                die("Couldn't run fast-export");
 908
 909        if (finish_command(&exporter))
 910                die("Error while running fast-export");
 911        if (push_update_refs_status(data, remote_refs, flags))
 912                return 1;
 913
 914        if (data->export_marks) {
 915                strbuf_addf(&buf, "%s.tmp", data->export_marks);
 916                rename(buf.buf, data->export_marks);
 917                strbuf_release(&buf);
 918        }
 919
 920        return 0;
 921}
 922
 923static int push_refs(struct transport *transport,
 924                struct ref *remote_refs, int flags)
 925{
 926        struct helper_data *data = transport->data;
 927
 928        if (process_connect(transport, 1)) {
 929                do_take_over(transport);
 930                return transport->push_refs(transport, remote_refs, flags);
 931        }
 932
 933        if (!remote_refs) {
 934                fprintf(stderr, "No refs in common and none specified; doing nothing.\n"
 935                        "Perhaps you should specify a branch such as 'master'.\n");
 936                return 0;
 937        }
 938
 939        if (data->push)
 940                return push_refs_with_push(transport, remote_refs, flags);
 941
 942        if (data->export)
 943                return push_refs_with_export(transport, remote_refs, flags);
 944
 945        return -1;
 946}
 947
 948
 949static int has_attribute(const char *attrs, const char *attr) {
 950        int len;
 951        if (!attrs)
 952                return 0;
 953
 954        len = strlen(attr);
 955        for (;;) {
 956                const char *space = strchrnul(attrs, ' ');
 957                if (len == space - attrs && !strncmp(attrs, attr, len))
 958                        return 1;
 959                if (!*space)
 960                        return 0;
 961                attrs = space + 1;
 962        }
 963}
 964
 965static struct ref *get_refs_list(struct transport *transport, int for_push)
 966{
 967        struct helper_data *data = transport->data;
 968        struct child_process *helper;
 969        struct ref *ret = NULL;
 970        struct ref **tail = &ret;
 971        struct ref *posn;
 972        struct strbuf buf = STRBUF_INIT;
 973
 974        helper = get_helper(transport);
 975
 976        if (process_connect(transport, for_push)) {
 977                do_take_over(transport);
 978                return transport->get_refs_list(transport, for_push);
 979        }
 980
 981        if (data->push && for_push)
 982                write_str_in_full(helper->in, "list for-push\n");
 983        else
 984                write_str_in_full(helper->in, "list\n");
 985
 986        while (1) {
 987                char *eov, *eon;
 988                if (recvline(data, &buf))
 989                        exit(128);
 990
 991                if (!*buf.buf)
 992                        break;
 993
 994                eov = strchr(buf.buf, ' ');
 995                if (!eov)
 996                        die("Malformed response in ref list: %s", buf.buf);
 997                eon = strchr(eov + 1, ' ');
 998                *eov = '\0';
 999                if (eon)
1000                        *eon = '\0';
1001                *tail = alloc_ref(eov + 1);
1002                if (buf.buf[0] == '@')
1003                        (*tail)->symref = xstrdup(buf.buf + 1);
1004                else if (buf.buf[0] != '?')
1005                        get_sha1_hex(buf.buf, (*tail)->old_sha1);
1006                if (eon) {
1007                        if (has_attribute(eon + 1, "unchanged")) {
1008                                (*tail)->status |= REF_STATUS_UPTODATE;
1009                                read_ref((*tail)->name, (*tail)->old_sha1);
1010                        }
1011                }
1012                tail = &((*tail)->next);
1013        }
1014        if (debug)
1015                fprintf(stderr, "Debug: Read ref listing.\n");
1016        strbuf_release(&buf);
1017
1018        for (posn = ret; posn; posn = posn->next)
1019                resolve_remote_symref(posn, ret);
1020
1021        return ret;
1022}
1023
1024int transport_helper_init(struct transport *transport, const char *name)
1025{
1026        struct helper_data *data = xcalloc(sizeof(*data), 1);
1027        data->name = name;
1028
1029        if (getenv("GIT_TRANSPORT_HELPER_DEBUG"))
1030                debug = 1;
1031
1032        transport->data = data;
1033        transport->set_option = set_helper_option;
1034        transport->get_refs_list = get_refs_list;
1035        transport->fetch = fetch;
1036        transport->push_refs = push_refs;
1037        transport->disconnect = release_helper;
1038        transport->connect = connect_helper;
1039        transport->smart_options = &(data->transport_options);
1040        return 0;
1041}
1042
1043/*
1044 * Linux pipes can buffer 65536 bytes at once (and most platforms can
1045 * buffer less), so attempt reads and writes with up to that size.
1046 */
1047#define BUFFERSIZE 65536
1048/* This should be enough to hold debugging message. */
1049#define PBUFFERSIZE 8192
1050
1051/* Print bidirectional transfer loop debug message. */
1052__attribute__((format (printf, 1, 2)))
1053static void transfer_debug(const char *fmt, ...)
1054{
1055        va_list args;
1056        char msgbuf[PBUFFERSIZE];
1057        static int debug_enabled = -1;
1058
1059        if (debug_enabled < 0)
1060                debug_enabled = getenv("GIT_TRANSLOOP_DEBUG") ? 1 : 0;
1061        if (!debug_enabled)
1062                return;
1063
1064        va_start(args, fmt);
1065        vsnprintf(msgbuf, PBUFFERSIZE, fmt, args);
1066        va_end(args);
1067        fprintf(stderr, "Transfer loop debugging: %s\n", msgbuf);
1068}
1069
1070/* Stream state: More data may be coming in this direction. */
1071#define SSTATE_TRANSFERING 0
1072/*
1073 * Stream state: No more data coming in this direction, flushing rest of
1074 * data.
1075 */
1076#define SSTATE_FLUSHING 1
1077/* Stream state: Transfer in this direction finished. */
1078#define SSTATE_FINISHED 2
1079
1080#define STATE_NEEDS_READING(state) ((state) <= SSTATE_TRANSFERING)
1081#define STATE_NEEDS_WRITING(state) ((state) <= SSTATE_FLUSHING)
1082#define STATE_NEEDS_CLOSING(state) ((state) == SSTATE_FLUSHING)
1083
1084/* Unidirectional transfer. */
1085struct unidirectional_transfer {
1086        /* Source */
1087        int src;
1088        /* Destination */
1089        int dest;
1090        /* Is source socket? */
1091        int src_is_sock;
1092        /* Is destination socket? */
1093        int dest_is_sock;
1094        /* Transfer state (TRANSFERRING/FLUSHING/FINISHED) */
1095        int state;
1096        /* Buffer. */
1097        char buf[BUFFERSIZE];
1098        /* Buffer used. */
1099        size_t bufuse;
1100        /* Name of source. */
1101        const char *src_name;
1102        /* Name of destination. */
1103        const char *dest_name;
1104};
1105
1106/* Closes the target (for writing) if transfer has finished. */
1107static void udt_close_if_finished(struct unidirectional_transfer *t)
1108{
1109        if (STATE_NEEDS_CLOSING(t->state) && !t->bufuse) {
1110                t->state = SSTATE_FINISHED;
1111                if (t->dest_is_sock)
1112                        shutdown(t->dest, SHUT_WR);
1113                else
1114                        close(t->dest);
1115                transfer_debug("Closed %s.", t->dest_name);
1116        }
1117}
1118
1119/*
1120 * Tries to read read data from source into buffer. If buffer is full,
1121 * no data is read. Returns 0 on success, -1 on error.
1122 */
1123static int udt_do_read(struct unidirectional_transfer *t)
1124{
1125        ssize_t bytes;
1126
1127        if (t->bufuse == BUFFERSIZE)
1128                return 0;       /* No space for more. */
1129
1130        transfer_debug("%s is readable", t->src_name);
1131        bytes = read(t->src, t->buf + t->bufuse, BUFFERSIZE - t->bufuse);
1132        if (bytes < 0 && errno != EWOULDBLOCK && errno != EAGAIN &&
1133                errno != EINTR) {
1134                error("read(%s) failed: %s", t->src_name, strerror(errno));
1135                return -1;
1136        } else if (bytes == 0) {
1137                transfer_debug("%s EOF (with %i bytes in buffer)",
1138                        t->src_name, (int)t->bufuse);
1139                t->state = SSTATE_FLUSHING;
1140        } else if (bytes > 0) {
1141                t->bufuse += bytes;
1142                transfer_debug("Read %i bytes from %s (buffer now at %i)",
1143                        (int)bytes, t->src_name, (int)t->bufuse);
1144        }
1145        return 0;
1146}
1147
1148/* Tries to write data from buffer into destination. If buffer is empty,
1149 * no data is written. Returns 0 on success, -1 on error.
1150 */
1151static int udt_do_write(struct unidirectional_transfer *t)
1152{
1153        ssize_t bytes;
1154
1155        if (t->bufuse == 0)
1156                return 0;       /* Nothing to write. */
1157
1158        transfer_debug("%s is writable", t->dest_name);
1159        bytes = xwrite(t->dest, t->buf, t->bufuse);
1160        if (bytes < 0 && errno != EWOULDBLOCK) {
1161                error("write(%s) failed: %s", t->dest_name, strerror(errno));
1162                return -1;
1163        } else if (bytes > 0) {
1164                t->bufuse -= bytes;
1165                if (t->bufuse)
1166                        memmove(t->buf, t->buf + bytes, t->bufuse);
1167                transfer_debug("Wrote %i bytes to %s (buffer now at %i)",
1168                        (int)bytes, t->dest_name, (int)t->bufuse);
1169        }
1170        return 0;
1171}
1172
1173
1174/* State of bidirectional transfer loop. */
1175struct bidirectional_transfer_state {
1176        /* Direction from program to git. */
1177        struct unidirectional_transfer ptg;
1178        /* Direction from git to program. */
1179        struct unidirectional_transfer gtp;
1180};
1181
1182static void *udt_copy_task_routine(void *udt)
1183{
1184        struct unidirectional_transfer *t = (struct unidirectional_transfer *)udt;
1185        while (t->state != SSTATE_FINISHED) {
1186                if (STATE_NEEDS_READING(t->state))
1187                        if (udt_do_read(t))
1188                                return NULL;
1189                if (STATE_NEEDS_WRITING(t->state))
1190                        if (udt_do_write(t))
1191                                return NULL;
1192                if (STATE_NEEDS_CLOSING(t->state))
1193                        udt_close_if_finished(t);
1194        }
1195        return udt;     /* Just some non-NULL value. */
1196}
1197
1198#ifndef NO_PTHREADS
1199
1200/*
1201 * Join thread, with appropriate errors on failure. Name is name for the
1202 * thread (for error messages). Returns 0 on success, 1 on failure.
1203 */
1204static int tloop_join(pthread_t thread, const char *name)
1205{
1206        int err;
1207        void *tret;
1208        err = pthread_join(thread, &tret);
1209        if (!tret) {
1210                error("%s thread failed", name);
1211                return 1;
1212        }
1213        if (err) {
1214                error("%s thread failed to join: %s", name, strerror(err));
1215                return 1;
1216        }
1217        return 0;
1218}
1219
1220/*
1221 * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1222 * -1 on failure.
1223 */
1224static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1225{
1226        pthread_t gtp_thread;
1227        pthread_t ptg_thread;
1228        int err;
1229        int ret = 0;
1230        err = pthread_create(&gtp_thread, NULL, udt_copy_task_routine,
1231                &s->gtp);
1232        if (err)
1233                die("Can't start thread for copying data: %s", strerror(err));
1234        err = pthread_create(&ptg_thread, NULL, udt_copy_task_routine,
1235                &s->ptg);
1236        if (err)
1237                die("Can't start thread for copying data: %s", strerror(err));
1238
1239        ret |= tloop_join(gtp_thread, "Git to program copy");
1240        ret |= tloop_join(ptg_thread, "Program to git copy");
1241        return ret;
1242}
1243#else
1244
1245/* Close the source and target (for writing) for transfer. */
1246static void udt_kill_transfer(struct unidirectional_transfer *t)
1247{
1248        t->state = SSTATE_FINISHED;
1249        /*
1250         * Socket read end left open isn't a disaster if nobody
1251         * attempts to read from it (mingw compat headers do not
1252         * have SHUT_RD)...
1253         *
1254         * We can't fully close the socket since otherwise gtp
1255         * task would first close the socket it sends data to
1256         * while closing the ptg file descriptors.
1257         */
1258        if (!t->src_is_sock)
1259                close(t->src);
1260        if (t->dest_is_sock)
1261                shutdown(t->dest, SHUT_WR);
1262        else
1263                close(t->dest);
1264}
1265
1266/*
1267 * Join process, with appropriate errors on failure. Name is name for the
1268 * process (for error messages). Returns 0 on success, 1 on failure.
1269 */
1270static int tloop_join(pid_t pid, const char *name)
1271{
1272        int tret;
1273        if (waitpid(pid, &tret, 0) < 0) {
1274                error("%s process failed to wait: %s", name, strerror(errno));
1275                return 1;
1276        }
1277        if (!WIFEXITED(tret) || WEXITSTATUS(tret)) {
1278                error("%s process failed", name);
1279                return 1;
1280        }
1281        return 0;
1282}
1283
1284/*
1285 * Spawn the transfer tasks and then wait for them. Returns 0 on success,
1286 * -1 on failure.
1287 */
1288static int tloop_spawnwait_tasks(struct bidirectional_transfer_state *s)
1289{
1290        pid_t pid1, pid2;
1291        int ret = 0;
1292
1293        /* Fork thread #1: git to program. */
1294        pid1 = fork();
1295        if (pid1 < 0)
1296                die_errno("Can't start thread for copying data");
1297        else if (pid1 == 0) {
1298                udt_kill_transfer(&s->ptg);
1299                exit(udt_copy_task_routine(&s->gtp) ? 0 : 1);
1300        }
1301
1302        /* Fork thread #2: program to git. */
1303        pid2 = fork();
1304        if (pid2 < 0)
1305                die_errno("Can't start thread for copying data");
1306        else if (pid2 == 0) {
1307                udt_kill_transfer(&s->gtp);
1308                exit(udt_copy_task_routine(&s->ptg) ? 0 : 1);
1309        }
1310
1311        /*
1312         * Close both streams in parent as to not interfere with
1313         * end of file detection and wait for both tasks to finish.
1314         */
1315        udt_kill_transfer(&s->gtp);
1316        udt_kill_transfer(&s->ptg);
1317        ret |= tloop_join(pid1, "Git to program copy");
1318        ret |= tloop_join(pid2, "Program to git copy");
1319        return ret;
1320}
1321#endif
1322
1323/*
1324 * Copies data from stdin to output and from input to stdout simultaneously.
1325 * Additionally filtering through given filter. If filter is NULL, uses
1326 * identity filter.
1327 */
1328int bidirectional_transfer_loop(int input, int output)
1329{
1330        struct bidirectional_transfer_state state;
1331
1332        /* Fill the state fields. */
1333        state.ptg.src = input;
1334        state.ptg.dest = 1;
1335        state.ptg.src_is_sock = (input == output);
1336        state.ptg.dest_is_sock = 0;
1337        state.ptg.state = SSTATE_TRANSFERING;
1338        state.ptg.bufuse = 0;
1339        state.ptg.src_name = "remote input";
1340        state.ptg.dest_name = "stdout";
1341
1342        state.gtp.src = 0;
1343        state.gtp.dest = output;
1344        state.gtp.src_is_sock = 0;
1345        state.gtp.dest_is_sock = (input == output);
1346        state.gtp.state = SSTATE_TRANSFERING;
1347        state.gtp.bufuse = 0;
1348        state.gtp.src_name = "stdin";
1349        state.gtp.dest_name = "remote output";
1350
1351        return tloop_spawnwait_tasks(&state);
1352}