Andrew's git / gitweb.git / connect.c
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connect.con commit Merge branch 'fp/submodule-checkout-mode' (1aeb10a)
   1#include "git-compat-util.h"
   2#include "cache.h"
   3#include "pkt-line.h"
   4#include "quote.h"
   5#include "refs.h"
   6#include "run-command.h"
   7#include "remote.h"
   8#include "connect.h"
   9#include "url.h"
  10#include "string-list.h"
  11#include "sha1-array.h"
  12
  13static char *server_capabilities;
  14static const char *parse_feature_value(const char *, const char *, int *);
  15
  16static int check_ref(const char *name, int len, unsigned int flags)
  17{
  18        if (!flags)
  19                return 1;
  20
  21        if (len < 5 || memcmp(name, "refs/", 5))
  22                return 0;
  23
  24        /* Skip the "refs/" part */
  25        name += 5;
  26        len -= 5;
  27
  28        /* REF_NORMAL means that we don't want the magic fake tag refs */
  29        if ((flags & REF_NORMAL) && check_refname_format(name, 0))
  30                return 0;
  31
  32        /* REF_HEADS means that we want regular branch heads */
  33        if ((flags & REF_HEADS) && !memcmp(name, "heads/", 6))
  34                return 1;
  35
  36        /* REF_TAGS means that we want tags */
  37        if ((flags & REF_TAGS) && !memcmp(name, "tags/", 5))
  38                return 1;
  39
  40        /* All type bits clear means that we are ok with anything */
  41        return !(flags & ~REF_NORMAL);
  42}
  43
  44int check_ref_type(const struct ref *ref, int flags)
  45{
  46        return check_ref(ref->name, strlen(ref->name), flags);
  47}
  48
  49static void die_initial_contact(int got_at_least_one_head)
  50{
  51        if (got_at_least_one_head)
  52                die("The remote end hung up upon initial contact");
  53        else
  54                die("Could not read from remote repository.\n\n"
  55                    "Please make sure you have the correct access rights\n"
  56                    "and the repository exists.");
  57}
  58
  59static void parse_one_symref_info(struct string_list *symref, const char *val, int len)
  60{
  61        char *sym, *target;
  62        struct string_list_item *item;
  63
  64        if (!len)
  65                return; /* just "symref" */
  66        /* e.g. "symref=HEAD:refs/heads/master" */
  67        sym = xmalloc(len + 1);
  68        memcpy(sym, val, len);
  69        sym[len] = '\0';
  70        target = strchr(sym, ':');
  71        if (!target)
  72                /* just "symref=something" */
  73                goto reject;
  74        *(target++) = '\0';
  75        if (check_refname_format(sym, REFNAME_ALLOW_ONELEVEL) ||
  76            check_refname_format(target, REFNAME_ALLOW_ONELEVEL))
  77                /* "symref=bogus:pair */
  78                goto reject;
  79        item = string_list_append(symref, sym);
  80        item->util = target;
  81        return;
  82reject:
  83        free(sym);
  84        return;
  85}
  86
  87static void annotate_refs_with_symref_info(struct ref *ref)
  88{
  89        struct string_list symref = STRING_LIST_INIT_DUP;
  90        const char *feature_list = server_capabilities;
  91
  92        while (feature_list) {
  93                int len;
  94                const char *val;
  95
  96                val = parse_feature_value(feature_list, "symref", &len);
  97                if (!val)
  98                        break;
  99                parse_one_symref_info(&symref, val, len);
 100                feature_list = val + 1;
 101        }
 102        sort_string_list(&symref);
 103
 104        for (; ref; ref = ref->next) {
 105                struct string_list_item *item;
 106                item = string_list_lookup(&symref, ref->name);
 107                if (!item)
 108                        continue;
 109                ref->symref = xstrdup((char *)item->util);
 110        }
 111        string_list_clear(&symref, 0);
 112}
 113
 114/*
 115 * Read all the refs from the other end
 116 */
 117struct ref **get_remote_heads(int in, char *src_buf, size_t src_len,
 118                              struct ref **list, unsigned int flags,
 119                              struct sha1_array *extra_have,
 120                              struct sha1_array *shallow_points)
 121{
 122        struct ref **orig_list = list;
 123        int got_at_least_one_head = 0;
 124
 125        *list = NULL;
 126        for (;;) {
 127                struct ref *ref;
 128                unsigned char old_sha1[20];
 129                char *name;
 130                int len, name_len;
 131                char *buffer = packet_buffer;
 132
 133                len = packet_read(in, &src_buf, &src_len,
 134                                  packet_buffer, sizeof(packet_buffer),
 135                                  PACKET_READ_GENTLE_ON_EOF |
 136                                  PACKET_READ_CHOMP_NEWLINE);
 137                if (len < 0)
 138                        die_initial_contact(got_at_least_one_head);
 139
 140                if (!len)
 141                        break;
 142
 143                if (len > 4 && starts_with(buffer, "ERR "))
 144                        die("remote error: %s", buffer + 4);
 145
 146                if (len == 48 && starts_with(buffer, "shallow ")) {
 147                        if (get_sha1_hex(buffer + 8, old_sha1))
 148                                die("protocol error: expected shallow sha-1, got '%s'", buffer + 8);
 149                        if (!shallow_points)
 150                                die("repository on the other end cannot be shallow");
 151                        sha1_array_append(shallow_points, old_sha1);
 152                        continue;
 153                }
 154
 155                if (len < 42 || get_sha1_hex(buffer, old_sha1) || buffer[40] != ' ')
 156                        die("protocol error: expected sha/ref, got '%s'", buffer);
 157                name = buffer + 41;
 158
 159                name_len = strlen(name);
 160                if (len != name_len + 41) {
 161                        free(server_capabilities);
 162                        server_capabilities = xstrdup(name + name_len + 1);
 163                }
 164
 165                if (extra_have &&
 166                    name_len == 5 && !memcmp(".have", name, 5)) {
 167                        sha1_array_append(extra_have, old_sha1);
 168                        continue;
 169                }
 170
 171                if (!check_ref(name, name_len, flags))
 172                        continue;
 173                ref = alloc_ref(buffer + 41);
 174                hashcpy(ref->old_sha1, old_sha1);
 175                *list = ref;
 176                list = &ref->next;
 177                got_at_least_one_head = 1;
 178        }
 179
 180        annotate_refs_with_symref_info(*orig_list);
 181
 182        return list;
 183}
 184
 185static const char *parse_feature_value(const char *feature_list, const char *feature, int *lenp)
 186{
 187        int len;
 188
 189        if (!feature_list)
 190                return NULL;
 191
 192        len = strlen(feature);
 193        while (*feature_list) {
 194                const char *found = strstr(feature_list, feature);
 195                if (!found)
 196                        return NULL;
 197                if (feature_list == found || isspace(found[-1])) {
 198                        const char *value = found + len;
 199                        /* feature with no value (e.g., "thin-pack") */
 200                        if (!*value || isspace(*value)) {
 201                                if (lenp)
 202                                        *lenp = 0;
 203                                return value;
 204                        }
 205                        /* feature with a value (e.g., "agent=git/1.2.3") */
 206                        else if (*value == '=') {
 207                                value++;
 208                                if (lenp)
 209                                        *lenp = strcspn(value, " \t\n");
 210                                return value;
 211                        }
 212                        /*
 213                         * otherwise we matched a substring of another feature;
 214                         * keep looking
 215                         */
 216                }
 217                feature_list = found + 1;
 218        }
 219        return NULL;
 220}
 221
 222int parse_feature_request(const char *feature_list, const char *feature)
 223{
 224        return !!parse_feature_value(feature_list, feature, NULL);
 225}
 226
 227const char *server_feature_value(const char *feature, int *len)
 228{
 229        return parse_feature_value(server_capabilities, feature, len);
 230}
 231
 232int server_supports(const char *feature)
 233{
 234        return !!server_feature_value(feature, NULL);
 235}
 236
 237enum protocol {
 238        PROTO_LOCAL = 1,
 239        PROTO_FILE,
 240        PROTO_SSH,
 241        PROTO_GIT
 242};
 243
 244int url_is_local_not_ssh(const char *url)
 245{
 246        const char *colon = strchr(url, ':');
 247        const char *slash = strchr(url, '/');
 248        return !colon || (slash && slash < colon) ||
 249                has_dos_drive_prefix(url);
 250}
 251
 252static const char *prot_name(enum protocol protocol)
 253{
 254        switch (protocol) {
 255                case PROTO_LOCAL:
 256                case PROTO_FILE:
 257                        return "file";
 258                case PROTO_SSH:
 259                        return "ssh";
 260                case PROTO_GIT:
 261                        return "git";
 262                default:
 263                        return "unkown protocol";
 264        }
 265}
 266
 267static enum protocol get_protocol(const char *name)
 268{
 269        if (!strcmp(name, "ssh"))
 270                return PROTO_SSH;
 271        if (!strcmp(name, "git"))
 272                return PROTO_GIT;
 273        if (!strcmp(name, "git+ssh"))
 274                return PROTO_SSH;
 275        if (!strcmp(name, "ssh+git"))
 276                return PROTO_SSH;
 277        if (!strcmp(name, "file"))
 278                return PROTO_FILE;
 279        die("I don't handle protocol '%s'", name);
 280}
 281
 282#define STR_(s) # s
 283#define STR(s)  STR_(s)
 284
 285static void get_host_and_port(char **host, const char **port)
 286{
 287        char *colon, *end;
 288
 289        if (*host[0] == '[') {
 290                end = strchr(*host + 1, ']');
 291                if (end) {
 292                        *end = 0;
 293                        end++;
 294                        (*host)++;
 295                } else
 296                        end = *host;
 297        } else
 298                end = *host;
 299        colon = strchr(end, ':');
 300
 301        if (colon) {
 302                *colon = 0;
 303                *port = colon + 1;
 304        }
 305}
 306
 307static void enable_keepalive(int sockfd)
 308{
 309        int ka = 1;
 310
 311        if (setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, &ka, sizeof(ka)) < 0)
 312                fprintf(stderr, "unable to set SO_KEEPALIVE on socket: %s\n",
 313                        strerror(errno));
 314}
 315
 316#ifndef NO_IPV6
 317
 318static const char *ai_name(const struct addrinfo *ai)
 319{
 320        static char addr[NI_MAXHOST];
 321        if (getnameinfo(ai->ai_addr, ai->ai_addrlen, addr, sizeof(addr), NULL, 0,
 322                        NI_NUMERICHOST) != 0)
 323                strcpy(addr, "(unknown)");
 324
 325        return addr;
 326}
 327
 328/*
 329 * Returns a connected socket() fd, or else die()s.
 330 */
 331static int git_tcp_connect_sock(char *host, int flags)
 332{
 333        struct strbuf error_message = STRBUF_INIT;
 334        int sockfd = -1;
 335        const char *port = STR(DEFAULT_GIT_PORT);
 336        struct addrinfo hints, *ai0, *ai;
 337        int gai;
 338        int cnt = 0;
 339
 340        get_host_and_port(&host, &port);
 341        if (!*port)
 342                port = "<none>";
 343
 344        memset(&hints, 0, sizeof(hints));
 345        hints.ai_socktype = SOCK_STREAM;
 346        hints.ai_protocol = IPPROTO_TCP;
 347
 348        if (flags & CONNECT_VERBOSE)
 349                fprintf(stderr, "Looking up %s ... ", host);
 350
 351        gai = getaddrinfo(host, port, &hints, &ai);
 352        if (gai)
 353                die("Unable to look up %s (port %s) (%s)", host, port, gai_strerror(gai));
 354
 355        if (flags & CONNECT_VERBOSE)
 356                fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 357
 358        for (ai0 = ai; ai; ai = ai->ai_next, cnt++) {
 359                sockfd = socket(ai->ai_family,
 360                                ai->ai_socktype, ai->ai_protocol);
 361                if ((sockfd < 0) ||
 362                    (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0)) {
 363                        strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 364                                    host, cnt, ai_name(ai), strerror(errno));
 365                        if (0 <= sockfd)
 366                                close(sockfd);
 367                        sockfd = -1;
 368                        continue;
 369                }
 370                if (flags & CONNECT_VERBOSE)
 371                        fprintf(stderr, "%s ", ai_name(ai));
 372                break;
 373        }
 374
 375        freeaddrinfo(ai0);
 376
 377        if (sockfd < 0)
 378                die("unable to connect to %s:\n%s", host, error_message.buf);
 379
 380        enable_keepalive(sockfd);
 381
 382        if (flags & CONNECT_VERBOSE)
 383                fprintf(stderr, "done.\n");
 384
 385        strbuf_release(&error_message);
 386
 387        return sockfd;
 388}
 389
 390#else /* NO_IPV6 */
 391
 392/*
 393 * Returns a connected socket() fd, or else die()s.
 394 */
 395static int git_tcp_connect_sock(char *host, int flags)
 396{
 397        struct strbuf error_message = STRBUF_INIT;
 398        int sockfd = -1;
 399        const char *port = STR(DEFAULT_GIT_PORT);
 400        char *ep;
 401        struct hostent *he;
 402        struct sockaddr_in sa;
 403        char **ap;
 404        unsigned int nport;
 405        int cnt;
 406
 407        get_host_and_port(&host, &port);
 408
 409        if (flags & CONNECT_VERBOSE)
 410                fprintf(stderr, "Looking up %s ... ", host);
 411
 412        he = gethostbyname(host);
 413        if (!he)
 414                die("Unable to look up %s (%s)", host, hstrerror(h_errno));
 415        nport = strtoul(port, &ep, 10);
 416        if ( ep == port || *ep ) {
 417                /* Not numeric */
 418                struct servent *se = getservbyname(port,"tcp");
 419                if ( !se )
 420                        die("Unknown port %s", port);
 421                nport = se->s_port;
 422        }
 423
 424        if (flags & CONNECT_VERBOSE)
 425                fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 426
 427        for (cnt = 0, ap = he->h_addr_list; *ap; ap++, cnt++) {
 428                memset(&sa, 0, sizeof sa);
 429                sa.sin_family = he->h_addrtype;
 430                sa.sin_port = htons(nport);
 431                memcpy(&sa.sin_addr, *ap, he->h_length);
 432
 433                sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 434                if ((sockfd < 0) ||
 435                    connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 436                        strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 437                                host,
 438                                cnt,
 439                                inet_ntoa(*(struct in_addr *)&sa.sin_addr),
 440                                strerror(errno));
 441                        if (0 <= sockfd)
 442                                close(sockfd);
 443                        sockfd = -1;
 444                        continue;
 445                }
 446                if (flags & CONNECT_VERBOSE)
 447                        fprintf(stderr, "%s ",
 448                                inet_ntoa(*(struct in_addr *)&sa.sin_addr));
 449                break;
 450        }
 451
 452        if (sockfd < 0)
 453                die("unable to connect to %s:\n%s", host, error_message.buf);
 454
 455        enable_keepalive(sockfd);
 456
 457        if (flags & CONNECT_VERBOSE)
 458                fprintf(stderr, "done.\n");
 459
 460        return sockfd;
 461}
 462
 463#endif /* NO_IPV6 */
 464
 465
 466static void git_tcp_connect(int fd[2], char *host, int flags)
 467{
 468        int sockfd = git_tcp_connect_sock(host, flags);
 469
 470        fd[0] = sockfd;
 471        fd[1] = dup(sockfd);
 472}
 473
 474
 475static char *git_proxy_command;
 476
 477static int git_proxy_command_options(const char *var, const char *value,
 478                void *cb)
 479{
 480        if (!strcmp(var, "core.gitproxy")) {
 481                const char *for_pos;
 482                int matchlen = -1;
 483                int hostlen;
 484                const char *rhost_name = cb;
 485                int rhost_len = strlen(rhost_name);
 486
 487                if (git_proxy_command)
 488                        return 0;
 489                if (!value)
 490                        return config_error_nonbool(var);
 491                /* [core]
 492                 * ;# matches www.kernel.org as well
 493                 * gitproxy = netcatter-1 for kernel.org
 494                 * gitproxy = netcatter-2 for sample.xz
 495                 * gitproxy = netcatter-default
 496                 */
 497                for_pos = strstr(value, " for ");
 498                if (!for_pos)
 499                        /* matches everybody */
 500                        matchlen = strlen(value);
 501                else {
 502                        hostlen = strlen(for_pos + 5);
 503                        if (rhost_len < hostlen)
 504                                matchlen = -1;
 505                        else if (!strncmp(for_pos + 5,
 506                                          rhost_name + rhost_len - hostlen,
 507                                          hostlen) &&
 508                                 ((rhost_len == hostlen) ||
 509                                  rhost_name[rhost_len - hostlen -1] == '.'))
 510                                matchlen = for_pos - value;
 511                        else
 512                                matchlen = -1;
 513                }
 514                if (0 <= matchlen) {
 515                        /* core.gitproxy = none for kernel.org */
 516                        if (matchlen == 4 &&
 517                            !memcmp(value, "none", 4))
 518                                matchlen = 0;
 519                        git_proxy_command = xmemdupz(value, matchlen);
 520                }
 521                return 0;
 522        }
 523
 524        return git_default_config(var, value, cb);
 525}
 526
 527static int git_use_proxy(const char *host)
 528{
 529        git_proxy_command = getenv("GIT_PROXY_COMMAND");
 530        git_config(git_proxy_command_options, (void*)host);
 531        return (git_proxy_command && *git_proxy_command);
 532}
 533
 534static struct child_process *git_proxy_connect(int fd[2], char *host)
 535{
 536        const char *port = STR(DEFAULT_GIT_PORT);
 537        const char **argv;
 538        struct child_process *proxy;
 539
 540        get_host_and_port(&host, &port);
 541
 542        argv = xmalloc(sizeof(*argv) * 4);
 543        argv[0] = git_proxy_command;
 544        argv[1] = host;
 545        argv[2] = port;
 546        argv[3] = NULL;
 547        proxy = xcalloc(1, sizeof(*proxy));
 548        proxy->argv = argv;
 549        proxy->in = -1;
 550        proxy->out = -1;
 551        if (start_command(proxy))
 552                die("cannot start proxy %s", argv[0]);
 553        fd[0] = proxy->out; /* read from proxy stdout */
 554        fd[1] = proxy->in;  /* write to proxy stdin */
 555        return proxy;
 556}
 557
 558static const char *get_port_numeric(const char *p)
 559{
 560        char *end;
 561        if (p) {
 562                long port = strtol(p + 1, &end, 10);
 563                if (end != p + 1 && *end == '\0' && 0 <= port && port < 65536) {
 564                        return p;
 565                }
 566        }
 567
 568        return NULL;
 569}
 570
 571/*
 572 * Extract protocol and relevant parts from the specified connection URL.
 573 * The caller must free() the returned strings.
 574 */
 575static enum protocol parse_connect_url(const char *url_orig, char **ret_host,
 576                                       char **ret_path)
 577{
 578        char *url;
 579        char *host, *path;
 580        char *end;
 581        int separator = '/';
 582        enum protocol protocol = PROTO_LOCAL;
 583
 584        if (is_url(url_orig))
 585                url = url_decode(url_orig);
 586        else
 587                url = xstrdup(url_orig);
 588
 589        host = strstr(url, "://");
 590        if (host) {
 591                *host = '\0';
 592                protocol = get_protocol(url);
 593                host += 3;
 594        } else {
 595                host = url;
 596                if (!url_is_local_not_ssh(url)) {
 597                        protocol = PROTO_SSH;
 598                        separator = ':';
 599                }
 600        }
 601
 602        /*
 603         * Don't do destructive transforms as protocol code does
 604         * '[]' unwrapping in get_host_and_port()
 605         */
 606        if (host[0] == '[') {
 607                end = strchr(host + 1, ']');
 608                if (end) {
 609                        end++;
 610                } else
 611                        end = host;
 612        } else
 613                end = host;
 614
 615        if (protocol == PROTO_LOCAL)
 616                path = end;
 617        else if (protocol == PROTO_FILE && has_dos_drive_prefix(end))
 618                path = end; /* "file://$(pwd)" may be "file://C:/projects/repo" */
 619        else
 620                path = strchr(end, separator);
 621
 622        if (!path || !*path)
 623                die("No path specified. See 'man git-pull' for valid url syntax");
 624
 625        /*
 626         * null-terminate hostname and point path to ~ for URL's like this:
 627         *    ssh://host.xz/~user/repo
 628         */
 629
 630        end = path; /* Need to \0 terminate host here */
 631        if (separator == ':')
 632                path++; /* path starts after ':' */
 633        if (protocol == PROTO_GIT || protocol == PROTO_SSH) {
 634                if (path[1] == '~')
 635                        path++;
 636        }
 637
 638        path = xstrdup(path);
 639        *end = '\0';
 640
 641        *ret_host = xstrdup(host);
 642        *ret_path = path;
 643        free(url);
 644        return protocol;
 645}
 646
 647static struct child_process no_fork;
 648
 649/*
 650 * This returns a dummy child_process if the transport protocol does not
 651 * need fork(2), or a struct child_process object if it does.  Once done,
 652 * finish the connection with finish_connect() with the value returned from
 653 * this function (it is safe to call finish_connect() with NULL to support
 654 * the former case).
 655 *
 656 * If it returns, the connect is successful; it just dies on errors (this
 657 * will hopefully be changed in a libification effort, to return NULL when
 658 * the connection failed).
 659 */
 660struct child_process *git_connect(int fd[2], const char *url,
 661                                  const char *prog, int flags)
 662{
 663        char *hostandport, *path;
 664        struct child_process *conn = &no_fork;
 665        enum protocol protocol;
 666        const char **arg;
 667        struct strbuf cmd = STRBUF_INIT;
 668
 669        /* Without this we cannot rely on waitpid() to tell
 670         * what happened to our children.
 671         */
 672        signal(SIGCHLD, SIG_DFL);
 673
 674        protocol = parse_connect_url(url, &hostandport, &path);
 675        if (flags & CONNECT_DIAG_URL) {
 676                printf("Diag: url=%s\n", url ? url : "NULL");
 677                printf("Diag: protocol=%s\n", prot_name(protocol));
 678                printf("Diag: hostandport=%s\n", hostandport ? hostandport : "NULL");
 679                printf("Diag: path=%s\n", path ? path : "NULL");
 680                conn = NULL;
 681        } else if (protocol == PROTO_GIT) {
 682                /* These underlying connection commands die() if they
 683                 * cannot connect.
 684                 */
 685                char *target_host = xstrdup(hostandport);
 686                if (git_use_proxy(hostandport))
 687                        conn = git_proxy_connect(fd, hostandport);
 688                else
 689                        git_tcp_connect(fd, hostandport, flags);
 690                /*
 691                 * Separate original protocol components prog and path
 692                 * from extended host header with a NUL byte.
 693                 *
 694                 * Note: Do not add any other headers here!  Doing so
 695                 * will cause older git-daemon servers to crash.
 696                 */
 697                packet_write(fd[1],
 698                             "%s %s%chost=%s%c",
 699                             prog, path, 0,
 700                             target_host, 0);
 701                free(target_host);
 702        } else {
 703                conn = xcalloc(1, sizeof(*conn));
 704
 705                strbuf_addstr(&cmd, prog);
 706                strbuf_addch(&cmd, ' ');
 707                sq_quote_buf(&cmd, path);
 708
 709                conn->in = conn->out = -1;
 710                conn->argv = arg = xcalloc(7, sizeof(*arg));
 711                if (protocol == PROTO_SSH) {
 712                        const char *ssh = getenv("GIT_SSH");
 713                        int putty = ssh && strcasestr(ssh, "plink");
 714                        char *ssh_host = hostandport;
 715                        const char *port = NULL;
 716                        get_host_and_port(&ssh_host, &port);
 717                        port = get_port_numeric(port);
 718
 719                        if (!ssh) ssh = "ssh";
 720
 721                        *arg++ = ssh;
 722                        if (putty && !strcasestr(ssh, "tortoiseplink"))
 723                                *arg++ = "-batch";
 724                        if (port) {
 725                                /* P is for PuTTY, p is for OpenSSH */
 726                                *arg++ = putty ? "-P" : "-p";
 727                                *arg++ = port;
 728                        }
 729                        *arg++ = ssh_host;
 730                }       else {
 731                        /* remove repo-local variables from the environment */
 732                        conn->env = local_repo_env;
 733                        conn->use_shell = 1;
 734                }
 735                *arg++ = cmd.buf;
 736                *arg = NULL;
 737
 738                if (start_command(conn))
 739                        die("unable to fork");
 740
 741                fd[0] = conn->out; /* read from child's stdout */
 742                fd[1] = conn->in;  /* write to child's stdin */
 743                strbuf_release(&cmd);
 744        }
 745        free(hostandport);
 746        free(path);
 747        return conn;
 748}
 749
 750int git_connection_is_socket(struct child_process *conn)
 751{
 752        return conn == &no_fork;
 753}
 754
 755int finish_connect(struct child_process *conn)
 756{
 757        int code;
 758        if (!conn || git_connection_is_socket(conn))
 759                return 0;
 760
 761        code = finish_command(conn);
 762        free(conn->argv);
 763        free(conn);
 764        return code;
 765}