Andrew's git / gitweb.git / transport.c
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transport.con commit manpages: use teletype font for sample command lines (db5d666)
   1#include "cache.h"
   2#include "transport.h"
   3#include "run-command.h"
   4#ifndef NO_CURL
   5#include "http.h"
   6#endif
   7#include "pkt-line.h"
   8#include "fetch-pack.h"
   9#include "send-pack.h"
  10#include "walker.h"
  11#include "bundle.h"
  12#include "dir.h"
  13#include "refs.h"
  14
  15/* rsync support */
  16
  17/*
  18 * We copy packed-refs and refs/ into a temporary file, then read the
  19 * loose refs recursively (sorting whenever possible), and then inserting
  20 * those packed refs that are not yet in the list (not validating, but
  21 * assuming that the file is sorted).
  22 *
  23 * Appears refactoring this from refs.c is too cumbersome.
  24 */
  25
  26static int str_cmp(const void *a, const void *b)
  27{
  28        const char *s1 = a;
  29        const char *s2 = b;
  30
  31        return strcmp(s1, s2);
  32}
  33
  34/* path->buf + name_offset is expected to point to "refs/" */
  35
  36static int read_loose_refs(struct strbuf *path, int name_offset,
  37                struct ref **tail)
  38{
  39        DIR *dir = opendir(path->buf);
  40        struct dirent *de;
  41        struct {
  42                char **entries;
  43                int nr, alloc;
  44        } list;
  45        int i, pathlen;
  46
  47        if (!dir)
  48                return -1;
  49
  50        memset (&list, 0, sizeof(list));
  51
  52        while ((de = readdir(dir))) {
  53                if (de->d_name[0] == '.' && (de->d_name[1] == '\0' ||
  54                                (de->d_name[1] == '.' &&
  55                                 de->d_name[2] == '\0')))
  56                        continue;
  57                ALLOC_GROW(list.entries, list.nr + 1, list.alloc);
  58                list.entries[list.nr++] = xstrdup(de->d_name);
  59        }
  60        closedir(dir);
  61
  62        /* sort the list */
  63
  64        qsort(list.entries, list.nr, sizeof(char *), str_cmp);
  65
  66        pathlen = path->len;
  67        strbuf_addch(path, '/');
  68
  69        for (i = 0; i < list.nr; i++, strbuf_setlen(path, pathlen + 1)) {
  70                strbuf_addstr(path, list.entries[i]);
  71                if (read_loose_refs(path, name_offset, tail)) {
  72                        int fd = open(path->buf, O_RDONLY);
  73                        char buffer[40];
  74                        struct ref *next;
  75
  76                        if (fd < 0)
  77                                continue;
  78                        next = alloc_ref(path->len - name_offset + 1);
  79                        if (read_in_full(fd, buffer, 40) != 40 ||
  80                                        get_sha1_hex(buffer, next->old_sha1)) {
  81                                close(fd);
  82                                free(next);
  83                                continue;
  84                        }
  85                        close(fd);
  86                        strcpy(next->name, path->buf + name_offset);
  87                        (*tail)->next = next;
  88                        *tail = next;
  89                }
  90        }
  91        strbuf_setlen(path, pathlen);
  92
  93        for (i = 0; i < list.nr; i++)
  94                free(list.entries[i]);
  95        free(list.entries);
  96
  97        return 0;
  98}
  99
 100/* insert the packed refs for which no loose refs were found */
 101
 102static void insert_packed_refs(const char *packed_refs, struct ref **list)
 103{
 104        FILE *f = fopen(packed_refs, "r");
 105        static char buffer[PATH_MAX];
 106
 107        if (!f)
 108                return;
 109
 110        for (;;) {
 111                int cmp = cmp, len;
 112
 113                if (!fgets(buffer, sizeof(buffer), f)) {
 114                        fclose(f);
 115                        return;
 116                }
 117
 118                if (hexval(buffer[0]) > 0xf)
 119                        continue;
 120                len = strlen(buffer);
 121                if (len && buffer[len - 1] == '\n')
 122                        buffer[--len] = '\0';
 123                if (len < 41)
 124                        continue;
 125                while ((*list)->next &&
 126                                (cmp = strcmp(buffer + 41,
 127                                      (*list)->next->name)) > 0)
 128                        list = &(*list)->next;
 129                if (!(*list)->next || cmp < 0) {
 130                        struct ref *next = alloc_ref(len - 40);
 131                        buffer[40] = '\0';
 132                        if (get_sha1_hex(buffer, next->old_sha1)) {
 133                                warning ("invalid SHA-1: %s", buffer);
 134                                free(next);
 135                                continue;
 136                        }
 137                        strcpy(next->name, buffer + 41);
 138                        next->next = (*list)->next;
 139                        (*list)->next = next;
 140                        list = &(*list)->next;
 141                }
 142        }
 143}
 144
 145static struct ref *get_refs_via_rsync(struct transport *transport)
 146{
 147        struct strbuf buf = STRBUF_INIT, temp_dir = STRBUF_INIT;
 148        struct ref dummy, *tail = &dummy;
 149        struct child_process rsync;
 150        const char *args[5];
 151        int temp_dir_len;
 152
 153        /* copy the refs to the temporary directory */
 154
 155        strbuf_addstr(&temp_dir, git_path("rsync-refs-XXXXXX"));
 156        if (!mkdtemp(temp_dir.buf))
 157                die ("Could not make temporary directory");
 158        temp_dir_len = temp_dir.len;
 159
 160        strbuf_addstr(&buf, transport->url);
 161        strbuf_addstr(&buf, "/refs");
 162
 163        memset(&rsync, 0, sizeof(rsync));
 164        rsync.argv = args;
 165        rsync.stdout_to_stderr = 1;
 166        args[0] = "rsync";
 167        args[1] = (transport->verbose > 0) ? "-rv" : "-r";
 168        args[2] = buf.buf;
 169        args[3] = temp_dir.buf;
 170        args[4] = NULL;
 171
 172        if (run_command(&rsync))
 173                die ("Could not run rsync to get refs");
 174
 175        strbuf_reset(&buf);
 176        strbuf_addstr(&buf, transport->url);
 177        strbuf_addstr(&buf, "/packed-refs");
 178
 179        args[2] = buf.buf;
 180
 181        if (run_command(&rsync))
 182                die ("Could not run rsync to get refs");
 183
 184        /* read the copied refs */
 185
 186        strbuf_addstr(&temp_dir, "/refs");
 187        read_loose_refs(&temp_dir, temp_dir_len + 1, &tail);
 188        strbuf_setlen(&temp_dir, temp_dir_len);
 189
 190        tail = &dummy;
 191        strbuf_addstr(&temp_dir, "/packed-refs");
 192        insert_packed_refs(temp_dir.buf, &tail);
 193        strbuf_setlen(&temp_dir, temp_dir_len);
 194
 195        if (remove_dir_recursively(&temp_dir, 0))
 196                warning ("Error removing temporary directory %s.",
 197                                temp_dir.buf);
 198
 199        strbuf_release(&buf);
 200        strbuf_release(&temp_dir);
 201
 202        return dummy.next;
 203}
 204
 205static int fetch_objs_via_rsync(struct transport *transport,
 206                                int nr_objs, const struct ref **to_fetch)
 207{
 208        struct strbuf buf = STRBUF_INIT;
 209        struct child_process rsync;
 210        const char *args[8];
 211        int result;
 212
 213        strbuf_addstr(&buf, transport->url);
 214        strbuf_addstr(&buf, "/objects/");
 215
 216        memset(&rsync, 0, sizeof(rsync));
 217        rsync.argv = args;
 218        rsync.stdout_to_stderr = 1;
 219        args[0] = "rsync";
 220        args[1] = (transport->verbose > 0) ? "-rv" : "-r";
 221        args[2] = "--ignore-existing";
 222        args[3] = "--exclude";
 223        args[4] = "info";
 224        args[5] = buf.buf;
 225        args[6] = get_object_directory();
 226        args[7] = NULL;
 227
 228        /* NEEDSWORK: handle one level of alternates */
 229        result = run_command(&rsync);
 230
 231        strbuf_release(&buf);
 232
 233        return result;
 234}
 235
 236static int write_one_ref(const char *name, const unsigned char *sha1,
 237                int flags, void *data)
 238{
 239        struct strbuf *buf = data;
 240        int len = buf->len;
 241        FILE *f;
 242
 243        /* when called via for_each_ref(), flags is non-zero */
 244        if (flags && prefixcmp(name, "refs/heads/") &&
 245                        prefixcmp(name, "refs/tags/"))
 246                return 0;
 247
 248        strbuf_addstr(buf, name);
 249        if (safe_create_leading_directories(buf->buf) ||
 250                        !(f = fopen(buf->buf, "w")) ||
 251                        fprintf(f, "%s\n", sha1_to_hex(sha1)) < 0 ||
 252                        fclose(f))
 253                return error("problems writing temporary file %s", buf->buf);
 254        strbuf_setlen(buf, len);
 255        return 0;
 256}
 257
 258static int write_refs_to_temp_dir(struct strbuf *temp_dir,
 259                int refspec_nr, const char **refspec)
 260{
 261        int i;
 262
 263        for (i = 0; i < refspec_nr; i++) {
 264                unsigned char sha1[20];
 265                char *ref;
 266
 267                if (dwim_ref(refspec[i], strlen(refspec[i]), sha1, &ref) != 1)
 268                        return error("Could not get ref %s", refspec[i]);
 269
 270                if (write_one_ref(ref, sha1, 0, temp_dir)) {
 271                        free(ref);
 272                        return -1;
 273                }
 274                free(ref);
 275        }
 276        return 0;
 277}
 278
 279static int rsync_transport_push(struct transport *transport,
 280                int refspec_nr, const char **refspec, int flags)
 281{
 282        struct strbuf buf = STRBUF_INIT, temp_dir = STRBUF_INIT;
 283        int result = 0, i;
 284        struct child_process rsync;
 285        const char *args[10];
 286
 287        if (flags & TRANSPORT_PUSH_MIRROR)
 288                return error("rsync transport does not support mirror mode");
 289
 290        /* first push the objects */
 291
 292        strbuf_addstr(&buf, transport->url);
 293        strbuf_addch(&buf, '/');
 294
 295        memset(&rsync, 0, sizeof(rsync));
 296        rsync.argv = args;
 297        rsync.stdout_to_stderr = 1;
 298        i = 0;
 299        args[i++] = "rsync";
 300        args[i++] = "-a";
 301        if (flags & TRANSPORT_PUSH_DRY_RUN)
 302                args[i++] = "--dry-run";
 303        if (transport->verbose > 0)
 304                args[i++] = "-v";
 305        args[i++] = "--ignore-existing";
 306        args[i++] = "--exclude";
 307        args[i++] = "info";
 308        args[i++] = get_object_directory();
 309        args[i++] = buf.buf;
 310        args[i++] = NULL;
 311
 312        if (run_command(&rsync))
 313                return error("Could not push objects to %s", transport->url);
 314
 315        /* copy the refs to the temporary directory; they could be packed. */
 316
 317        strbuf_addstr(&temp_dir, git_path("rsync-refs-XXXXXX"));
 318        if (!mkdtemp(temp_dir.buf))
 319                die ("Could not make temporary directory");
 320        strbuf_addch(&temp_dir, '/');
 321
 322        if (flags & TRANSPORT_PUSH_ALL) {
 323                if (for_each_ref(write_one_ref, &temp_dir))
 324                        return -1;
 325        } else if (write_refs_to_temp_dir(&temp_dir, refspec_nr, refspec))
 326                return -1;
 327
 328        i = 2;
 329        if (flags & TRANSPORT_PUSH_DRY_RUN)
 330                args[i++] = "--dry-run";
 331        if (!(flags & TRANSPORT_PUSH_FORCE))
 332                args[i++] = "--ignore-existing";
 333        args[i++] = temp_dir.buf;
 334        args[i++] = transport->url;
 335        args[i++] = NULL;
 336        if (run_command(&rsync))
 337                result = error("Could not push to %s", transport->url);
 338
 339        if (remove_dir_recursively(&temp_dir, 0))
 340                warning ("Could not remove temporary directory %s.",
 341                                temp_dir.buf);
 342
 343        strbuf_release(&buf);
 344        strbuf_release(&temp_dir);
 345
 346        return result;
 347}
 348
 349/* Generic functions for using commit walkers */
 350
 351#ifndef NO_CURL /* http fetch is the only user */
 352static int fetch_objs_via_walker(struct transport *transport,
 353                                 int nr_objs, const struct ref **to_fetch)
 354{
 355        char *dest = xstrdup(transport->url);
 356        struct walker *walker = transport->data;
 357        char **objs = xmalloc(nr_objs * sizeof(*objs));
 358        int i;
 359
 360        walker->get_all = 1;
 361        walker->get_tree = 1;
 362        walker->get_history = 1;
 363        walker->get_verbosely = transport->verbose >= 0;
 364        walker->get_recover = 0;
 365
 366        for (i = 0; i < nr_objs; i++)
 367                objs[i] = xstrdup(sha1_to_hex(to_fetch[i]->old_sha1));
 368
 369        if (walker_fetch(walker, nr_objs, objs, NULL, NULL))
 370                die("Fetch failed.");
 371
 372        for (i = 0; i < nr_objs; i++)
 373                free(objs[i]);
 374        free(objs);
 375        free(dest);
 376        return 0;
 377}
 378#endif /* NO_CURL */
 379
 380static int disconnect_walker(struct transport *transport)
 381{
 382        struct walker *walker = transport->data;
 383        if (walker)
 384                walker_free(walker);
 385        return 0;
 386}
 387
 388#ifndef NO_CURL
 389static int curl_transport_push(struct transport *transport, int refspec_nr, const char **refspec, int flags)
 390{
 391        const char **argv;
 392        int argc;
 393        int err;
 394
 395        if (flags & TRANSPORT_PUSH_MIRROR)
 396                return error("http transport does not support mirror mode");
 397
 398        argv = xmalloc((refspec_nr + 12) * sizeof(char *));
 399        argv[0] = "http-push";
 400        argc = 1;
 401        if (flags & TRANSPORT_PUSH_ALL)
 402                argv[argc++] = "--all";
 403        if (flags & TRANSPORT_PUSH_FORCE)
 404                argv[argc++] = "--force";
 405        if (flags & TRANSPORT_PUSH_DRY_RUN)
 406                argv[argc++] = "--dry-run";
 407        if (flags & TRANSPORT_PUSH_VERBOSE)
 408                argv[argc++] = "--verbose";
 409        argv[argc++] = transport->url;
 410        while (refspec_nr--)
 411                argv[argc++] = *refspec++;
 412        argv[argc] = NULL;
 413        err = run_command_v_opt(argv, RUN_GIT_CMD);
 414        switch (err) {
 415        case -ERR_RUN_COMMAND_FORK:
 416                error("unable to fork for %s", argv[0]);
 417        case -ERR_RUN_COMMAND_EXEC:
 418                error("unable to exec %s", argv[0]);
 419                break;
 420        case -ERR_RUN_COMMAND_WAITPID:
 421        case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
 422        case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
 423        case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
 424                error("%s died with strange error", argv[0]);
 425        }
 426        return !!err;
 427}
 428
 429static struct ref *get_refs_via_curl(struct transport *transport)
 430{
 431        struct strbuf buffer = STRBUF_INIT;
 432        char *data, *start, *mid;
 433        char *ref_name;
 434        char *refs_url;
 435        int i = 0;
 436
 437        struct active_request_slot *slot;
 438        struct slot_results results;
 439
 440        struct ref *refs = NULL;
 441        struct ref *ref = NULL;
 442        struct ref *last_ref = NULL;
 443
 444        struct walker *walker;
 445
 446        if (!transport->data)
 447                transport->data = get_http_walker(transport->url,
 448                                                transport->remote);
 449
 450        walker = transport->data;
 451
 452        refs_url = xmalloc(strlen(transport->url) + 11);
 453        sprintf(refs_url, "%s/info/refs", transport->url);
 454
 455        slot = get_active_slot();
 456        slot->results = &results;
 457        curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
 458        curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
 459        curl_easy_setopt(slot->curl, CURLOPT_URL, refs_url);
 460        curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, NULL);
 461
 462        if (start_active_slot(slot)) {
 463                run_active_slot(slot);
 464                if (results.curl_result != CURLE_OK) {
 465                        strbuf_release(&buffer);
 466                        if (missing_target(&results)) {
 467                                return NULL;
 468                        } else {
 469                                error("%s", curl_errorstr);
 470                                return NULL;
 471                        }
 472                }
 473        } else {
 474                strbuf_release(&buffer);
 475                error("Unable to start request");
 476                return NULL;
 477        }
 478
 479        data = buffer.buf;
 480        start = NULL;
 481        mid = data;
 482        while (i < buffer.len) {
 483                if (!start)
 484                        start = &data[i];
 485                if (data[i] == '\t')
 486                        mid = &data[i];
 487                if (data[i] == '\n') {
 488                        data[i] = 0;
 489                        ref_name = mid + 1;
 490                        ref = xmalloc(sizeof(struct ref) +
 491                                      strlen(ref_name) + 1);
 492                        memset(ref, 0, sizeof(struct ref));
 493                        strcpy(ref->name, ref_name);
 494                        get_sha1_hex(start, ref->old_sha1);
 495                        if (!refs)
 496                                refs = ref;
 497                        if (last_ref)
 498                                last_ref->next = ref;
 499                        last_ref = ref;
 500                        start = NULL;
 501                }
 502                i++;
 503        }
 504
 505        strbuf_release(&buffer);
 506
 507        ref = alloc_ref_from_str("HEAD");
 508        if (!walker->fetch_ref(walker, ref) &&
 509            !resolve_remote_symref(ref, refs)) {
 510                ref->next = refs;
 511                refs = ref;
 512        } else {
 513                free(ref);
 514        }
 515
 516        return refs;
 517}
 518
 519static int fetch_objs_via_curl(struct transport *transport,
 520                                 int nr_objs, const struct ref **to_fetch)
 521{
 522        if (!transport->data)
 523                transport->data = get_http_walker(transport->url,
 524                                                transport->remote);
 525        return fetch_objs_via_walker(transport, nr_objs, to_fetch);
 526}
 527
 528#endif
 529
 530struct bundle_transport_data {
 531        int fd;
 532        struct bundle_header header;
 533};
 534
 535static struct ref *get_refs_from_bundle(struct transport *transport)
 536{
 537        struct bundle_transport_data *data = transport->data;
 538        struct ref *result = NULL;
 539        int i;
 540
 541        if (data->fd > 0)
 542                close(data->fd);
 543        data->fd = read_bundle_header(transport->url, &data->header);
 544        if (data->fd < 0)
 545                die ("Could not read bundle '%s'.", transport->url);
 546        for (i = 0; i < data->header.references.nr; i++) {
 547                struct ref_list_entry *e = data->header.references.list + i;
 548                struct ref *ref = alloc_ref_from_str(e->name);
 549                hashcpy(ref->old_sha1, e->sha1);
 550                ref->next = result;
 551                result = ref;
 552        }
 553        return result;
 554}
 555
 556static int fetch_refs_from_bundle(struct transport *transport,
 557                               int nr_heads, const struct ref **to_fetch)
 558{
 559        struct bundle_transport_data *data = transport->data;
 560        return unbundle(&data->header, data->fd);
 561}
 562
 563static int close_bundle(struct transport *transport)
 564{
 565        struct bundle_transport_data *data = transport->data;
 566        if (data->fd > 0)
 567                close(data->fd);
 568        free(data);
 569        return 0;
 570}
 571
 572struct git_transport_data {
 573        unsigned thin : 1;
 574        unsigned keep : 1;
 575        unsigned followtags : 1;
 576        int depth;
 577        struct child_process *conn;
 578        int fd[2];
 579        const char *uploadpack;
 580        const char *receivepack;
 581};
 582
 583static int set_git_option(struct transport *connection,
 584                          const char *name, const char *value)
 585{
 586        struct git_transport_data *data = connection->data;
 587        if (!strcmp(name, TRANS_OPT_UPLOADPACK)) {
 588                data->uploadpack = value;
 589                return 0;
 590        } else if (!strcmp(name, TRANS_OPT_RECEIVEPACK)) {
 591                data->receivepack = value;
 592                return 0;
 593        } else if (!strcmp(name, TRANS_OPT_THIN)) {
 594                data->thin = !!value;
 595                return 0;
 596        } else if (!strcmp(name, TRANS_OPT_FOLLOWTAGS)) {
 597                data->followtags = !!value;
 598                return 0;
 599        } else if (!strcmp(name, TRANS_OPT_KEEP)) {
 600                data->keep = !!value;
 601                return 0;
 602        } else if (!strcmp(name, TRANS_OPT_DEPTH)) {
 603                if (!value)
 604                        data->depth = 0;
 605                else
 606                        data->depth = atoi(value);
 607                return 0;
 608        }
 609        return 1;
 610}
 611
 612static int connect_setup(struct transport *transport)
 613{
 614        struct git_transport_data *data = transport->data;
 615        data->conn = git_connect(data->fd, transport->url, data->uploadpack, 0);
 616        return 0;
 617}
 618
 619static struct ref *get_refs_via_connect(struct transport *transport)
 620{
 621        struct git_transport_data *data = transport->data;
 622        struct ref *refs;
 623
 624        connect_setup(transport);
 625        get_remote_heads(data->fd[0], &refs, 0, NULL, 0);
 626
 627        return refs;
 628}
 629
 630static int fetch_refs_via_pack(struct transport *transport,
 631                               int nr_heads, const struct ref **to_fetch)
 632{
 633        struct git_transport_data *data = transport->data;
 634        char **heads = xmalloc(nr_heads * sizeof(*heads));
 635        char **origh = xmalloc(nr_heads * sizeof(*origh));
 636        const struct ref *refs;
 637        char *dest = xstrdup(transport->url);
 638        struct fetch_pack_args args;
 639        int i;
 640        struct ref *refs_tmp = NULL;
 641
 642        memset(&args, 0, sizeof(args));
 643        args.uploadpack = data->uploadpack;
 644        args.keep_pack = data->keep;
 645        args.lock_pack = 1;
 646        args.use_thin_pack = data->thin;
 647        args.include_tag = data->followtags;
 648        args.verbose = transport->verbose > 0;
 649        args.depth = data->depth;
 650
 651        for (i = 0; i < nr_heads; i++)
 652                origh[i] = heads[i] = xstrdup(to_fetch[i]->name);
 653
 654        if (!data->conn) {
 655                connect_setup(transport);
 656                get_remote_heads(data->fd[0], &refs_tmp, 0, NULL, 0);
 657        }
 658
 659        refs = fetch_pack(&args, data->fd, data->conn,
 660                          refs_tmp ? refs_tmp : transport->remote_refs,
 661                          dest, nr_heads, heads, &transport->pack_lockfile);
 662        close(data->fd[0]);
 663        close(data->fd[1]);
 664        if (finish_connect(data->conn))
 665                refs = NULL;
 666        data->conn = NULL;
 667
 668        free_refs(refs_tmp);
 669
 670        for (i = 0; i < nr_heads; i++)
 671                free(origh[i]);
 672        free(origh);
 673        free(heads);
 674        free(dest);
 675        return (refs ? 0 : -1);
 676}
 677
 678static int git_transport_push(struct transport *transport, int refspec_nr, const char **refspec, int flags)
 679{
 680        struct git_transport_data *data = transport->data;
 681        struct send_pack_args args;
 682
 683        args.receivepack = data->receivepack;
 684        args.send_all = !!(flags & TRANSPORT_PUSH_ALL);
 685        args.send_mirror = !!(flags & TRANSPORT_PUSH_MIRROR);
 686        args.force_update = !!(flags & TRANSPORT_PUSH_FORCE);
 687        args.use_thin_pack = data->thin;
 688        args.verbose = !!(flags & TRANSPORT_PUSH_VERBOSE);
 689        args.dry_run = !!(flags & TRANSPORT_PUSH_DRY_RUN);
 690
 691        return send_pack(&args, transport->url, transport->remote, refspec_nr, refspec);
 692}
 693
 694static int disconnect_git(struct transport *transport)
 695{
 696        struct git_transport_data *data = transport->data;
 697        if (data->conn) {
 698                packet_flush(data->fd[1]);
 699                close(data->fd[0]);
 700                close(data->fd[1]);
 701                finish_connect(data->conn);
 702        }
 703
 704        free(data);
 705        return 0;
 706}
 707
 708static int is_local(const char *url)
 709{
 710        const char *colon = strchr(url, ':');
 711        const char *slash = strchr(url, '/');
 712        return !colon || (slash && slash < colon) ||
 713                has_dos_drive_prefix(url);
 714}
 715
 716static int is_file(const char *url)
 717{
 718        struct stat buf;
 719        if (stat(url, &buf))
 720                return 0;
 721        return S_ISREG(buf.st_mode);
 722}
 723
 724struct transport *transport_get(struct remote *remote, const char *url)
 725{
 726        struct transport *ret = xcalloc(1, sizeof(*ret));
 727
 728        ret->remote = remote;
 729        ret->url = url;
 730
 731        if (!prefixcmp(url, "rsync://")) {
 732                ret->get_refs_list = get_refs_via_rsync;
 733                ret->fetch = fetch_objs_via_rsync;
 734                ret->push = rsync_transport_push;
 735
 736        } else if (!prefixcmp(url, "http://")
 737                || !prefixcmp(url, "https://")
 738                || !prefixcmp(url, "ftp://")) {
 739#ifdef NO_CURL
 740                error("git was compiled without libcurl support.");
 741#else
 742                ret->get_refs_list = get_refs_via_curl;
 743                ret->fetch = fetch_objs_via_curl;
 744                ret->push = curl_transport_push;
 745#endif
 746                ret->disconnect = disconnect_walker;
 747
 748        } else if (is_local(url) && is_file(url)) {
 749                struct bundle_transport_data *data = xcalloc(1, sizeof(*data));
 750                ret->data = data;
 751                ret->get_refs_list = get_refs_from_bundle;
 752                ret->fetch = fetch_refs_from_bundle;
 753                ret->disconnect = close_bundle;
 754
 755        } else {
 756                struct git_transport_data *data = xcalloc(1, sizeof(*data));
 757                ret->data = data;
 758                ret->set_option = set_git_option;
 759                ret->get_refs_list = get_refs_via_connect;
 760                ret->fetch = fetch_refs_via_pack;
 761                ret->push = git_transport_push;
 762                ret->disconnect = disconnect_git;
 763
 764                data->thin = 1;
 765                data->conn = NULL;
 766                data->uploadpack = "git-upload-pack";
 767                if (remote && remote->uploadpack)
 768                        data->uploadpack = remote->uploadpack;
 769                data->receivepack = "git-receive-pack";
 770                if (remote && remote->receivepack)
 771                        data->receivepack = remote->receivepack;
 772        }
 773
 774        return ret;
 775}
 776
 777int transport_set_option(struct transport *transport,
 778                         const char *name, const char *value)
 779{
 780        if (transport->set_option)
 781                return transport->set_option(transport, name, value);
 782        return 1;
 783}
 784
 785int transport_push(struct transport *transport,
 786                   int refspec_nr, const char **refspec, int flags)
 787{
 788        if (!transport->push)
 789                return 1;
 790        return transport->push(transport, refspec_nr, refspec, flags);
 791}
 792
 793const struct ref *transport_get_remote_refs(struct transport *transport)
 794{
 795        if (!transport->remote_refs)
 796                transport->remote_refs = transport->get_refs_list(transport);
 797        return transport->remote_refs;
 798}
 799
 800int transport_fetch_refs(struct transport *transport, const struct ref *refs)
 801{
 802        int rc;
 803        int nr_heads = 0, nr_alloc = 0;
 804        const struct ref **heads = NULL;
 805        const struct ref *rm;
 806
 807        for (rm = refs; rm; rm = rm->next) {
 808                if (rm->peer_ref &&
 809                    !hashcmp(rm->peer_ref->old_sha1, rm->old_sha1))
 810                        continue;
 811                ALLOC_GROW(heads, nr_heads + 1, nr_alloc);
 812                heads[nr_heads++] = rm;
 813        }
 814
 815        rc = transport->fetch(transport, nr_heads, heads);
 816        free(heads);
 817        return rc;
 818}
 819
 820void transport_unlock_pack(struct transport *transport)
 821{
 822        if (transport->pack_lockfile) {
 823                unlink(transport->pack_lockfile);
 824                free(transport->pack_lockfile);
 825                transport->pack_lockfile = NULL;
 826        }
 827}
 828
 829int transport_disconnect(struct transport *transport)
 830{
 831        int ret = 0;
 832        if (transport->disconnect)
 833                ret = transport->disconnect(transport);
 834        free(transport);
 835        return ret;
 836}