Andrew's git / gitweb.git / transport-helper.c
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transport-helper.con commit Windows: boost startup by avoiding a static dependency on shell32.dll (928500e)
   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
  11static int debug;
  12
  13struct helper_data
  14{
  15        const char *name;
  16        struct child_process *helper;
  17        FILE *out;
  18        unsigned fetch : 1,
  19                import : 1,
  20                option : 1,
  21                push : 1,
  22                connect : 1,
  23                no_disconnect_req : 1;
  24        /* These go from remote name (as in "list") to private name */
  25        struct refspec *refspecs;
  26        int refspec_nr;
  27        /* Transport options for fetch-pack/send-pack (should one of
  28         * those be invoked).
  29         */
  30        struct git_transport_options transport_options;
  31};
  32
  33static void sendline(struct helper_data *helper, struct strbuf *buffer)
  34{
  35        if (debug)
  36                fprintf(stderr, "Debug: Remote helper: -> %s", buffer->buf);
  37        if (write_in_full(helper->helper->in, buffer->buf, buffer->len)
  38                != buffer->len)
  39                die_errno("Full write to remote helper failed");
  40}
  41
  42static int recvline_fh(FILE *helper, struct strbuf *buffer)
  43{
  44        strbuf_reset(buffer);
  45        if (debug)
  46                fprintf(stderr, "Debug: Remote helper: Waiting...\n");
  47        if (strbuf_getline(buffer, helper, '\n') == EOF) {
  48                if (debug)
  49                        fprintf(stderr, "Debug: Remote helper quit.\n");
  50                exit(128);
  51        }
  52
  53        if (debug)
  54                fprintf(stderr, "Debug: Remote helper: <- %s\n", buffer->buf);
  55        return 0;
  56}
  57
  58static int recvline(struct helper_data *helper, struct strbuf *buffer)
  59{
  60        return recvline_fh(helper->out, buffer);
  61}
  62
  63static void xchgline(struct helper_data *helper, struct strbuf *buffer)
  64{
  65        sendline(helper, buffer);
  66        recvline(helper, buffer);
  67}
  68
  69static void write_constant(int fd, const char *str)
  70{
  71        if (debug)
  72                fprintf(stderr, "Debug: Remote helper: -> %s", str);
  73        if (write_in_full(fd, str, strlen(str)) != strlen(str))
  74                die_errno("Full write to remote helper failed");
  75}
  76
  77const char *remove_ext_force(const char *url)
  78{
  79        if (url) {
  80                const char *colon = strchr(url, ':');
  81                if (colon && colon[1] == ':')
  82                        return colon + 2;
  83        }
  84        return url;
  85}
  86
  87static void do_take_over(struct transport *transport)
  88{
  89        struct helper_data *data;
  90        data = (struct helper_data *)transport->data;
  91        transport_take_over(transport, data->helper);
  92        fclose(data->out);
  93        free(data);
  94}
  95
  96static struct child_process *get_helper(struct transport *transport)
  97{
  98        struct helper_data *data = transport->data;
  99        struct strbuf buf = STRBUF_INIT;
 100        struct child_process *helper;
 101        const char **refspecs = NULL;
 102        int refspec_nr = 0;
 103        int refspec_alloc = 0;
 104        int duped;
 105
 106        if (data->helper)
 107                return data->helper;
 108
 109        helper = xcalloc(1, sizeof(*helper));
 110        helper->in = -1;
 111        helper->out = -1;
 112        helper->err = 0;
 113        helper->argv = xcalloc(4, sizeof(*helper->argv));
 114        strbuf_addf(&buf, "remote-%s", data->name);
 115        helper->argv[0] = strbuf_detach(&buf, NULL);
 116        helper->argv[1] = transport->remote->name;
 117        helper->argv[2] = remove_ext_force(transport->url);
 118        helper->git_cmd = 1;
 119        if (start_command(helper))
 120                die("Unable to run helper: git %s", helper->argv[0]);
 121        data->helper = helper;
 122        data->no_disconnect_req = 0;
 123
 124        /*
 125         * Open the output as FILE* so strbuf_getline() can be used.
 126         * Do this with duped fd because fclose() will close the fd,
 127         * and stuff like taking over will require the fd to remain.
 128         */
 129        duped = dup(helper->out);
 130        if (duped < 0)
 131                die_errno("Can't dup helper output fd");
 132        data->out = xfdopen(duped, "r");
 133
 134        write_constant(helper->in, "capabilities\n");
 135
 136        while (1) {
 137                const char *capname;
 138                int mandatory = 0;
 139                recvline(data, &buf);
 140
 141                if (!*buf.buf)
 142                        break;
 143
 144                if (*buf.buf == '*') {
 145                        capname = buf.buf + 1;
 146                        mandatory = 1;
 147                } else
 148                        capname = buf.buf;
 149
 150                if (debug)
 151                        fprintf(stderr, "Debug: Got cap %s\n", capname);
 152                if (!strcmp(capname, "fetch"))
 153                        data->fetch = 1;
 154                else if (!strcmp(capname, "option"))
 155                        data->option = 1;
 156                else if (!strcmp(capname, "push"))
 157                        data->push = 1;
 158                else if (!strcmp(capname, "import"))
 159                        data->import = 1;
 160                else if (!data->refspecs && !prefixcmp(capname, "refspec ")) {
 161                        ALLOC_GROW(refspecs,
 162                                   refspec_nr + 1,
 163                                   refspec_alloc);
 164                        refspecs[refspec_nr++] = strdup(buf.buf + strlen("refspec "));
 165                } else if (!strcmp(capname, "connect")) {
 166                        data->connect = 1;
 167                } else if (mandatory) {
 168                        die("Unknown madatory capability %s. This remote "
 169                            "helper probably needs newer version of Git.\n",
 170                            capname);
 171                }
 172        }
 173        if (refspecs) {
 174                int i;
 175                data->refspec_nr = refspec_nr;
 176                data->refspecs = parse_fetch_refspec(refspec_nr, refspecs);
 177                for (i = 0; i < refspec_nr; i++) {
 178                        free((char *)refspecs[i]);
 179                }
 180                free(refspecs);
 181        }
 182        strbuf_release(&buf);
 183        if (debug)
 184                fprintf(stderr, "Debug: Capabilities complete.\n");
 185        return data->helper;
 186}
 187
 188static int disconnect_helper(struct transport *transport)
 189{
 190        struct helper_data *data = transport->data;
 191        struct strbuf buf = STRBUF_INIT;
 192
 193        if (data->helper) {
 194                if (debug)
 195                        fprintf(stderr, "Debug: Disconnecting.\n");
 196                if (!data->no_disconnect_req) {
 197                        strbuf_addf(&buf, "\n");
 198                        sendline(data, &buf);
 199                }
 200                close(data->helper->in);
 201                close(data->helper->out);
 202                fclose(data->out);
 203                finish_command(data->helper);
 204                free((char *)data->helper->argv[0]);
 205                free(data->helper->argv);
 206                free(data->helper);
 207                data->helper = NULL;
 208        }
 209        return 0;
 210}
 211
 212static const char *unsupported_options[] = {
 213        TRANS_OPT_UPLOADPACK,
 214        TRANS_OPT_RECEIVEPACK,
 215        TRANS_OPT_THIN,
 216        TRANS_OPT_KEEP
 217        };
 218static const char *boolean_options[] = {
 219        TRANS_OPT_THIN,
 220        TRANS_OPT_KEEP,
 221        TRANS_OPT_FOLLOWTAGS
 222        };
 223
 224static int set_helper_option(struct transport *transport,
 225                          const char *name, const char *value)
 226{
 227        struct helper_data *data = transport->data;
 228        struct strbuf buf = STRBUF_INIT;
 229        int i, ret, is_bool = 0;
 230
 231        get_helper(transport);
 232
 233        if (!data->option)
 234                return 1;
 235
 236        for (i = 0; i < ARRAY_SIZE(unsupported_options); i++) {
 237                if (!strcmp(name, unsupported_options[i]))
 238                        return 1;
 239        }
 240
 241        for (i = 0; i < ARRAY_SIZE(boolean_options); i++) {
 242                if (!strcmp(name, boolean_options[i])) {
 243                        is_bool = 1;
 244                        break;
 245                }
 246        }
 247
 248        strbuf_addf(&buf, "option %s ", name);
 249        if (is_bool)
 250                strbuf_addstr(&buf, value ? "true" : "false");
 251        else
 252                quote_c_style(value, &buf, NULL, 0);
 253        strbuf_addch(&buf, '\n');
 254
 255        xchgline(data, &buf);
 256
 257        if (!strcmp(buf.buf, "ok"))
 258                ret = 0;
 259        else if (!prefixcmp(buf.buf, "error")) {
 260                ret = -1;
 261        } else if (!strcmp(buf.buf, "unsupported"))
 262                ret = 1;
 263        else {
 264                warning("%s unexpectedly said: '%s'", data->name, buf.buf);
 265                ret = 1;
 266        }
 267        strbuf_release(&buf);
 268        return ret;
 269}
 270
 271static void standard_options(struct transport *t)
 272{
 273        char buf[16];
 274        int n;
 275        int v = t->verbose;
 276        int no_progress = v < 0 || (!t->progress && !isatty(1));
 277
 278        set_helper_option(t, "progress", !no_progress ? "true" : "false");
 279
 280        n = snprintf(buf, sizeof(buf), "%d", v + 1);
 281        if (n >= sizeof(buf))
 282                die("impossibly large verbosity value");
 283        set_helper_option(t, "verbosity", buf);
 284}
 285
 286static int release_helper(struct transport *transport)
 287{
 288        struct helper_data *data = transport->data;
 289        free_refspec(data->refspec_nr, data->refspecs);
 290        data->refspecs = NULL;
 291        disconnect_helper(transport);
 292        free(transport->data);
 293        return 0;
 294}
 295
 296static int fetch_with_fetch(struct transport *transport,
 297                            int nr_heads, struct ref **to_fetch)
 298{
 299        struct helper_data *data = transport->data;
 300        int i;
 301        struct strbuf buf = STRBUF_INIT;
 302
 303        standard_options(transport);
 304
 305        for (i = 0; i < nr_heads; i++) {
 306                const struct ref *posn = to_fetch[i];
 307                if (posn->status & REF_STATUS_UPTODATE)
 308                        continue;
 309
 310                strbuf_addf(&buf, "fetch %s %s\n",
 311                            sha1_to_hex(posn->old_sha1), posn->name);
 312        }
 313
 314        strbuf_addch(&buf, '\n');
 315        sendline(data, &buf);
 316
 317        while (1) {
 318                recvline(data, &buf);
 319
 320                if (!prefixcmp(buf.buf, "lock ")) {
 321                        const char *name = buf.buf + 5;
 322                        if (transport->pack_lockfile)
 323                                warning("%s also locked %s", data->name, name);
 324                        else
 325                                transport->pack_lockfile = xstrdup(name);
 326                }
 327                else if (!buf.len)
 328                        break;
 329                else
 330                        warning("%s unexpectedly said: '%s'", data->name, buf.buf);
 331        }
 332        strbuf_release(&buf);
 333        return 0;
 334}
 335
 336static int get_importer(struct transport *transport, struct child_process *fastimport)
 337{
 338        struct child_process *helper = get_helper(transport);
 339        memset(fastimport, 0, sizeof(*fastimport));
 340        fastimport->in = helper->out;
 341        fastimport->argv = xcalloc(5, sizeof(*fastimport->argv));
 342        fastimport->argv[0] = "fast-import";
 343        fastimport->argv[1] = "--quiet";
 344
 345        fastimport->git_cmd = 1;
 346        return start_command(fastimport);
 347}
 348
 349static int fetch_with_import(struct transport *transport,
 350                             int nr_heads, struct ref **to_fetch)
 351{
 352        struct child_process fastimport;
 353        struct helper_data *data = transport->data;
 354        int i;
 355        struct ref *posn;
 356        struct strbuf buf = STRBUF_INIT;
 357
 358        get_helper(transport);
 359
 360        if (get_importer(transport, &fastimport))
 361                die("Couldn't run fast-import");
 362
 363        for (i = 0; i < nr_heads; i++) {
 364                posn = to_fetch[i];
 365                if (posn->status & REF_STATUS_UPTODATE)
 366                        continue;
 367
 368                strbuf_addf(&buf, "import %s\n", posn->name);
 369                sendline(data, &buf);
 370                strbuf_reset(&buf);
 371        }
 372        disconnect_helper(transport);
 373        finish_command(&fastimport);
 374        free(fastimport.argv);
 375        fastimport.argv = NULL;
 376
 377        for (i = 0; i < nr_heads; i++) {
 378                char *private;
 379                posn = to_fetch[i];
 380                if (posn->status & REF_STATUS_UPTODATE)
 381                        continue;
 382                if (data->refspecs)
 383                        private = apply_refspecs(data->refspecs, data->refspec_nr, posn->name);
 384                else
 385                        private = strdup(posn->name);
 386                read_ref(private, posn->old_sha1);
 387                free(private);
 388        }
 389        strbuf_release(&buf);
 390        return 0;
 391}
 392
 393static int process_connect_service(struct transport *transport,
 394                                   const char *name, const char *exec)
 395{
 396        struct helper_data *data = transport->data;
 397        struct strbuf cmdbuf = STRBUF_INIT;
 398        struct child_process *helper;
 399        int r, duped, ret = 0;
 400        FILE *input;
 401
 402        helper = get_helper(transport);
 403
 404        /*
 405         * Yes, dup the pipe another time, as we need unbuffered version
 406         * of input pipe as FILE*. fclose() closes the underlying fd and
 407         * stream buffering only can be changed before first I/O operation
 408         * on it.
 409         */
 410        duped = dup(helper->out);
 411        if (duped < 0)
 412                die_errno("Can't dup helper output fd");
 413        input = xfdopen(duped, "r");
 414        setvbuf(input, NULL, _IONBF, 0);
 415
 416        /*
 417         * Handle --upload-pack and friends. This is fire and forget...
 418         * just warn if it fails.
 419         */
 420        if (strcmp(name, exec)) {
 421                r = set_helper_option(transport, "servpath", exec);
 422                if (r > 0)
 423                        warning("Setting remote service path not supported by protocol.");
 424                else if (r < 0)
 425                        warning("Invalid remote service path.");
 426        }
 427
 428        if (data->connect)
 429                strbuf_addf(&cmdbuf, "connect %s\n", name);
 430        else
 431                goto exit;
 432
 433        sendline(data, &cmdbuf);
 434        recvline_fh(input, &cmdbuf);
 435        if (!strcmp(cmdbuf.buf, "")) {
 436                data->no_disconnect_req = 1;
 437                if (debug)
 438                        fprintf(stderr, "Debug: Smart transport connection "
 439                                "ready.\n");
 440                ret = 1;
 441        } else if (!strcmp(cmdbuf.buf, "fallback")) {
 442                if (debug)
 443                        fprintf(stderr, "Debug: Falling back to dumb "
 444                                "transport.\n");
 445        } else
 446                die("Unknown response to connect: %s",
 447                        cmdbuf.buf);
 448
 449exit:
 450        fclose(input);
 451        return ret;
 452}
 453
 454static int process_connect(struct transport *transport,
 455                                     int for_push)
 456{
 457        struct helper_data *data = transport->data;
 458        const char *name;
 459        const char *exec;
 460
 461        name = for_push ? "git-receive-pack" : "git-upload-pack";
 462        if (for_push)
 463                exec = data->transport_options.receivepack;
 464        else
 465                exec = data->transport_options.uploadpack;
 466
 467        return process_connect_service(transport, name, exec);
 468}
 469
 470static int connect_helper(struct transport *transport, const char *name,
 471                   const char *exec, int fd[2])
 472{
 473        struct helper_data *data = transport->data;
 474
 475        /* Get_helper so connect is inited. */
 476        get_helper(transport);
 477        if (!data->connect)
 478                die("Operation not supported by protocol.");
 479
 480        if (!process_connect_service(transport, name, exec))
 481                die("Can't connect to subservice %s.", name);
 482
 483        fd[0] = data->helper->out;
 484        fd[1] = data->helper->in;
 485        return 0;
 486}
 487
 488static int fetch(struct transport *transport,
 489                 int nr_heads, struct ref **to_fetch)
 490{
 491        struct helper_data *data = transport->data;
 492        int i, count;
 493
 494        if (process_connect(transport, 0)) {
 495                do_take_over(transport);
 496                return transport->fetch(transport, nr_heads, to_fetch);
 497        }
 498
 499        count = 0;
 500        for (i = 0; i < nr_heads; i++)
 501                if (!(to_fetch[i]->status & REF_STATUS_UPTODATE))
 502                        count++;
 503
 504        if (!count)
 505                return 0;
 506
 507        if (data->fetch)
 508                return fetch_with_fetch(transport, nr_heads, to_fetch);
 509
 510        if (data->import)
 511                return fetch_with_import(transport, nr_heads, to_fetch);
 512
 513        return -1;
 514}
 515
 516static int push_refs(struct transport *transport,
 517                struct ref *remote_refs, int flags)
 518{
 519        int force_all = flags & TRANSPORT_PUSH_FORCE;
 520        int mirror = flags & TRANSPORT_PUSH_MIRROR;
 521        struct helper_data *data = transport->data;
 522        struct strbuf buf = STRBUF_INIT;
 523        struct child_process *helper;
 524        struct ref *ref;
 525
 526        if (process_connect(transport, 1)) {
 527                do_take_over(transport);
 528                return transport->push_refs(transport, remote_refs, flags);
 529        }
 530
 531        if (!remote_refs)
 532                return 0;
 533
 534        helper = get_helper(transport);
 535        if (!data->push)
 536                return 1;
 537
 538        for (ref = remote_refs; ref; ref = ref->next) {
 539                if (ref->peer_ref)
 540                        hashcpy(ref->new_sha1, ref->peer_ref->new_sha1);
 541                else if (!mirror)
 542                        continue;
 543
 544                ref->deletion = is_null_sha1(ref->new_sha1);
 545                if (!ref->deletion &&
 546                        !hashcmp(ref->old_sha1, ref->new_sha1)) {
 547                        ref->status = REF_STATUS_UPTODATE;
 548                        continue;
 549                }
 550
 551                if (force_all)
 552                        ref->force = 1;
 553
 554                strbuf_addstr(&buf, "push ");
 555                if (!ref->deletion) {
 556                        if (ref->force)
 557                                strbuf_addch(&buf, '+');
 558                        if (ref->peer_ref)
 559                                strbuf_addstr(&buf, ref->peer_ref->name);
 560                        else
 561                                strbuf_addstr(&buf, sha1_to_hex(ref->new_sha1));
 562                }
 563                strbuf_addch(&buf, ':');
 564                strbuf_addstr(&buf, ref->name);
 565                strbuf_addch(&buf, '\n');
 566        }
 567        if (buf.len == 0)
 568                return 0;
 569
 570        transport->verbose = flags & TRANSPORT_PUSH_VERBOSE ? 1 : 0;
 571        standard_options(transport);
 572
 573        if (flags & TRANSPORT_PUSH_DRY_RUN) {
 574                if (set_helper_option(transport, "dry-run", "true") != 0)
 575                        die("helper %s does not support dry-run", data->name);
 576        }
 577
 578        strbuf_addch(&buf, '\n');
 579        sendline(data, &buf);
 580
 581        ref = remote_refs;
 582        while (1) {
 583                char *refname, *msg;
 584                int status;
 585
 586                recvline(data, &buf);
 587                if (!buf.len)
 588                        break;
 589
 590                if (!prefixcmp(buf.buf, "ok ")) {
 591                        status = REF_STATUS_OK;
 592                        refname = buf.buf + 3;
 593                } else if (!prefixcmp(buf.buf, "error ")) {
 594                        status = REF_STATUS_REMOTE_REJECT;
 595                        refname = buf.buf + 6;
 596                } else
 597                        die("expected ok/error, helper said '%s'\n", buf.buf);
 598
 599                msg = strchr(refname, ' ');
 600                if (msg) {
 601                        struct strbuf msg_buf = STRBUF_INIT;
 602                        const char *end;
 603
 604                        *msg++ = '\0';
 605                        if (!unquote_c_style(&msg_buf, msg, &end))
 606                                msg = strbuf_detach(&msg_buf, NULL);
 607                        else
 608                                msg = xstrdup(msg);
 609                        strbuf_release(&msg_buf);
 610
 611                        if (!strcmp(msg, "no match")) {
 612                                status = REF_STATUS_NONE;
 613                                free(msg);
 614                                msg = NULL;
 615                        }
 616                        else if (!strcmp(msg, "up to date")) {
 617                                status = REF_STATUS_UPTODATE;
 618                                free(msg);
 619                                msg = NULL;
 620                        }
 621                        else if (!strcmp(msg, "non-fast forward")) {
 622                                status = REF_STATUS_REJECT_NONFASTFORWARD;
 623                                free(msg);
 624                                msg = NULL;
 625                        }
 626                }
 627
 628                if (ref)
 629                        ref = find_ref_by_name(ref, refname);
 630                if (!ref)
 631                        ref = find_ref_by_name(remote_refs, refname);
 632                if (!ref) {
 633                        warning("helper reported unexpected status of %s", refname);
 634                        continue;
 635                }
 636
 637                ref->status = status;
 638                ref->remote_status = msg;
 639        }
 640        strbuf_release(&buf);
 641        return 0;
 642}
 643
 644static int has_attribute(const char *attrs, const char *attr) {
 645        int len;
 646        if (!attrs)
 647                return 0;
 648
 649        len = strlen(attr);
 650        for (;;) {
 651                const char *space = strchrnul(attrs, ' ');
 652                if (len == space - attrs && !strncmp(attrs, attr, len))
 653                        return 1;
 654                if (!*space)
 655                        return 0;
 656                attrs = space + 1;
 657        }
 658}
 659
 660static struct ref *get_refs_list(struct transport *transport, int for_push)
 661{
 662        struct helper_data *data = transport->data;
 663        struct child_process *helper;
 664        struct ref *ret = NULL;
 665        struct ref **tail = &ret;
 666        struct ref *posn;
 667        struct strbuf buf = STRBUF_INIT;
 668
 669        helper = get_helper(transport);
 670
 671        if (process_connect(transport, for_push)) {
 672                do_take_over(transport);
 673                return transport->get_refs_list(transport, for_push);
 674        }
 675
 676        if (data->push && for_push)
 677                write_str_in_full(helper->in, "list for-push\n");
 678        else
 679                write_str_in_full(helper->in, "list\n");
 680
 681        while (1) {
 682                char *eov, *eon;
 683                recvline(data, &buf);
 684
 685                if (!*buf.buf)
 686                        break;
 687
 688                eov = strchr(buf.buf, ' ');
 689                if (!eov)
 690                        die("Malformed response in ref list: %s", buf.buf);
 691                eon = strchr(eov + 1, ' ');
 692                *eov = '\0';
 693                if (eon)
 694                        *eon = '\0';
 695                *tail = alloc_ref(eov + 1);
 696                if (buf.buf[0] == '@')
 697                        (*tail)->symref = xstrdup(buf.buf + 1);
 698                else if (buf.buf[0] != '?')
 699                        get_sha1_hex(buf.buf, (*tail)->old_sha1);
 700                if (eon) {
 701                        if (has_attribute(eon + 1, "unchanged")) {
 702                                (*tail)->status |= REF_STATUS_UPTODATE;
 703                                read_ref((*tail)->name, (*tail)->old_sha1);
 704                        }
 705                }
 706                tail = &((*tail)->next);
 707        }
 708        if (debug)
 709                fprintf(stderr, "Debug: Read ref listing.\n");
 710        strbuf_release(&buf);
 711
 712        for (posn = ret; posn; posn = posn->next)
 713                resolve_remote_symref(posn, ret);
 714
 715        return ret;
 716}
 717
 718int transport_helper_init(struct transport *transport, const char *name)
 719{
 720        struct helper_data *data = xcalloc(sizeof(*data), 1);
 721        data->name = name;
 722
 723        if (getenv("GIT_TRANSPORT_HELPER_DEBUG"))
 724                debug = 1;
 725
 726        transport->data = data;
 727        transport->set_option = set_helper_option;
 728        transport->get_refs_list = get_refs_list;
 729        transport->fetch = fetch;
 730        transport->push_refs = push_refs;
 731        transport->disconnect = release_helper;
 732        transport->connect = connect_helper;
 733        transport->smart_options = &(data->transport_options);
 734        return 0;
 735}