connect.con commit Merge branch 'js/fsck-name-object' (8f58a34)
   1#include "git-compat-util.h"
   2#include "cache.h"
   3#include "config.h"
   4#include "pkt-line.h"
   5#include "quote.h"
   6#include "refs.h"
   7#include "run-command.h"
   8#include "remote.h"
   9#include "connect.h"
  10#include "url.h"
  11#include "string-list.h"
  12#include "sha1-array.h"
  13#include "transport.h"
  14
  15static char *server_capabilities;
  16static const char *parse_feature_value(const char *, const char *, int *);
  17
  18static int check_ref(const char *name, unsigned int flags)
  19{
  20        if (!flags)
  21                return 1;
  22
  23        if (!skip_prefix(name, "refs/", &name))
  24                return 0;
  25
  26        /* REF_NORMAL means that we don't want the magic fake tag refs */
  27        if ((flags & REF_NORMAL) && check_refname_format(name, 0))
  28                return 0;
  29
  30        /* REF_HEADS means that we want regular branch heads */
  31        if ((flags & REF_HEADS) && starts_with(name, "heads/"))
  32                return 1;
  33
  34        /* REF_TAGS means that we want tags */
  35        if ((flags & REF_TAGS) && starts_with(name, "tags/"))
  36                return 1;
  37
  38        /* All type bits clear means that we are ok with anything */
  39        return !(flags & ~REF_NORMAL);
  40}
  41
  42int check_ref_type(const struct ref *ref, int flags)
  43{
  44        return check_ref(ref->name, flags);
  45}
  46
  47static void die_initial_contact(int unexpected)
  48{
  49        if (unexpected)
  50                die(_("The remote end hung up upon initial contact"));
  51        else
  52                die(_("Could not read from remote repository.\n\n"
  53                      "Please make sure you have the correct access rights\n"
  54                      "and the repository exists."));
  55}
  56
  57static void parse_one_symref_info(struct string_list *symref, const char *val, int len)
  58{
  59        char *sym, *target;
  60        struct string_list_item *item;
  61
  62        if (!len)
  63                return; /* just "symref" */
  64        /* e.g. "symref=HEAD:refs/heads/master" */
  65        sym = xmemdupz(val, len);
  66        target = strchr(sym, ':');
  67        if (!target)
  68                /* just "symref=something" */
  69                goto reject;
  70        *(target++) = '\0';
  71        if (check_refname_format(sym, REFNAME_ALLOW_ONELEVEL) ||
  72            check_refname_format(target, REFNAME_ALLOW_ONELEVEL))
  73                /* "symref=bogus:pair */
  74                goto reject;
  75        item = string_list_append_nodup(symref, sym);
  76        item->util = target;
  77        return;
  78reject:
  79        free(sym);
  80        return;
  81}
  82
  83static void annotate_refs_with_symref_info(struct ref *ref)
  84{
  85        struct string_list symref = STRING_LIST_INIT_DUP;
  86        const char *feature_list = server_capabilities;
  87
  88        while (feature_list) {
  89                int len;
  90                const char *val;
  91
  92                val = parse_feature_value(feature_list, "symref", &len);
  93                if (!val)
  94                        break;
  95                parse_one_symref_info(&symref, val, len);
  96                feature_list = val + 1;
  97        }
  98        string_list_sort(&symref);
  99
 100        for (; ref; ref = ref->next) {
 101                struct string_list_item *item;
 102                item = string_list_lookup(&symref, ref->name);
 103                if (!item)
 104                        continue;
 105                ref->symref = xstrdup((char *)item->util);
 106        }
 107        string_list_clear(&symref, 0);
 108}
 109
 110/*
 111 * Read all the refs from the other end
 112 */
 113struct ref **get_remote_heads(int in, char *src_buf, size_t src_len,
 114                              struct ref **list, unsigned int flags,
 115                              struct oid_array *extra_have,
 116                              struct oid_array *shallow_points)
 117{
 118        struct ref **orig_list = list;
 119
 120        /*
 121         * A hang-up after seeing some response from the other end
 122         * means that it is unexpected, as we know the other end is
 123         * willing to talk to us.  A hang-up before seeing any
 124         * response does not necessarily mean an ACL problem, though.
 125         */
 126        int saw_response;
 127        int got_dummy_ref_with_capabilities_declaration = 0;
 128
 129        *list = NULL;
 130        for (saw_response = 0; ; saw_response = 1) {
 131                struct ref *ref;
 132                struct object_id old_oid;
 133                char *name;
 134                int len, name_len;
 135                char *buffer = packet_buffer;
 136                const char *arg;
 137
 138                len = packet_read(in, &src_buf, &src_len,
 139                                  packet_buffer, sizeof(packet_buffer),
 140                                  PACKET_READ_GENTLE_ON_EOF |
 141                                  PACKET_READ_CHOMP_NEWLINE);
 142                if (len < 0)
 143                        die_initial_contact(saw_response);
 144
 145                if (!len)
 146                        break;
 147
 148                if (len > 4 && skip_prefix(buffer, "ERR ", &arg))
 149                        die("remote error: %s", arg);
 150
 151                if (len == GIT_SHA1_HEXSZ + strlen("shallow ") &&
 152                        skip_prefix(buffer, "shallow ", &arg)) {
 153                        if (get_oid_hex(arg, &old_oid))
 154                                die("protocol error: expected shallow sha-1, got '%s'", arg);
 155                        if (!shallow_points)
 156                                die("repository on the other end cannot be shallow");
 157                        oid_array_append(shallow_points, &old_oid);
 158                        continue;
 159                }
 160
 161                if (len < GIT_SHA1_HEXSZ + 2 || get_oid_hex(buffer, &old_oid) ||
 162                        buffer[GIT_SHA1_HEXSZ] != ' ')
 163                        die("protocol error: expected sha/ref, got '%s'", buffer);
 164                name = buffer + GIT_SHA1_HEXSZ + 1;
 165
 166                name_len = strlen(name);
 167                if (len != name_len + GIT_SHA1_HEXSZ + 1) {
 168                        free(server_capabilities);
 169                        server_capabilities = xstrdup(name + name_len + 1);
 170                }
 171
 172                if (extra_have && !strcmp(name, ".have")) {
 173                        oid_array_append(extra_have, &old_oid);
 174                        continue;
 175                }
 176
 177                if (!strcmp(name, "capabilities^{}")) {
 178                        if (saw_response)
 179                                die("protocol error: unexpected capabilities^{}");
 180                        if (got_dummy_ref_with_capabilities_declaration)
 181                                die("protocol error: multiple capabilities^{}");
 182                        got_dummy_ref_with_capabilities_declaration = 1;
 183                        continue;
 184                }
 185
 186                if (!check_ref(name, flags))
 187                        continue;
 188
 189                if (got_dummy_ref_with_capabilities_declaration)
 190                        die("protocol error: unexpected ref after capabilities^{}");
 191
 192                ref = alloc_ref(buffer + GIT_SHA1_HEXSZ + 1);
 193                oidcpy(&ref->old_oid, &old_oid);
 194                *list = ref;
 195                list = &ref->next;
 196        }
 197
 198        annotate_refs_with_symref_info(*orig_list);
 199
 200        return list;
 201}
 202
 203static const char *parse_feature_value(const char *feature_list, const char *feature, int *lenp)
 204{
 205        int len;
 206
 207        if (!feature_list)
 208                return NULL;
 209
 210        len = strlen(feature);
 211        while (*feature_list) {
 212                const char *found = strstr(feature_list, feature);
 213                if (!found)
 214                        return NULL;
 215                if (feature_list == found || isspace(found[-1])) {
 216                        const char *value = found + len;
 217                        /* feature with no value (e.g., "thin-pack") */
 218                        if (!*value || isspace(*value)) {
 219                                if (lenp)
 220                                        *lenp = 0;
 221                                return value;
 222                        }
 223                        /* feature with a value (e.g., "agent=git/1.2.3") */
 224                        else if (*value == '=') {
 225                                value++;
 226                                if (lenp)
 227                                        *lenp = strcspn(value, " \t\n");
 228                                return value;
 229                        }
 230                        /*
 231                         * otherwise we matched a substring of another feature;
 232                         * keep looking
 233                         */
 234                }
 235                feature_list = found + 1;
 236        }
 237        return NULL;
 238}
 239
 240int parse_feature_request(const char *feature_list, const char *feature)
 241{
 242        return !!parse_feature_value(feature_list, feature, NULL);
 243}
 244
 245const char *server_feature_value(const char *feature, int *len)
 246{
 247        return parse_feature_value(server_capabilities, feature, len);
 248}
 249
 250int server_supports(const char *feature)
 251{
 252        return !!server_feature_value(feature, NULL);
 253}
 254
 255enum protocol {
 256        PROTO_LOCAL = 1,
 257        PROTO_FILE,
 258        PROTO_SSH,
 259        PROTO_GIT
 260};
 261
 262int url_is_local_not_ssh(const char *url)
 263{
 264        const char *colon = strchr(url, ':');
 265        const char *slash = strchr(url, '/');
 266        return !colon || (slash && slash < colon) ||
 267                has_dos_drive_prefix(url);
 268}
 269
 270static const char *prot_name(enum protocol protocol)
 271{
 272        switch (protocol) {
 273                case PROTO_LOCAL:
 274                case PROTO_FILE:
 275                        return "file";
 276                case PROTO_SSH:
 277                        return "ssh";
 278                case PROTO_GIT:
 279                        return "git";
 280                default:
 281                        return "unknown protocol";
 282        }
 283}
 284
 285static enum protocol get_protocol(const char *name)
 286{
 287        if (!strcmp(name, "ssh"))
 288                return PROTO_SSH;
 289        if (!strcmp(name, "git"))
 290                return PROTO_GIT;
 291        if (!strcmp(name, "git+ssh")) /* deprecated - do not use */
 292                return PROTO_SSH;
 293        if (!strcmp(name, "ssh+git")) /* deprecated - do not use */
 294                return PROTO_SSH;
 295        if (!strcmp(name, "file"))
 296                return PROTO_FILE;
 297        die("I don't handle protocol '%s'", name);
 298}
 299
 300static char *host_end(char **hoststart, int removebrackets)
 301{
 302        char *host = *hoststart;
 303        char *end;
 304        char *start = strstr(host, "@[");
 305        if (start)
 306                start++; /* Jump over '@' */
 307        else
 308                start = host;
 309        if (start[0] == '[') {
 310                end = strchr(start + 1, ']');
 311                if (end) {
 312                        if (removebrackets) {
 313                                *end = 0;
 314                                memmove(start, start + 1, end - start);
 315                                end++;
 316                        }
 317                } else
 318                        end = host;
 319        } else
 320                end = host;
 321        return end;
 322}
 323
 324#define STR_(s) # s
 325#define STR(s)  STR_(s)
 326
 327static void get_host_and_port(char **host, const char **port)
 328{
 329        char *colon, *end;
 330        end = host_end(host, 1);
 331        colon = strchr(end, ':');
 332        if (colon) {
 333                long portnr = strtol(colon + 1, &end, 10);
 334                if (end != colon + 1 && *end == '\0' && 0 <= portnr && portnr < 65536) {
 335                        *colon = 0;
 336                        *port = colon + 1;
 337                } else if (!colon[1]) {
 338                        *colon = 0;
 339                }
 340        }
 341}
 342
 343static void enable_keepalive(int sockfd)
 344{
 345        int ka = 1;
 346
 347        if (setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, &ka, sizeof(ka)) < 0)
 348                fprintf(stderr, "unable to set SO_KEEPALIVE on socket: %s\n",
 349                        strerror(errno));
 350}
 351
 352#ifndef NO_IPV6
 353
 354static const char *ai_name(const struct addrinfo *ai)
 355{
 356        static char addr[NI_MAXHOST];
 357        if (getnameinfo(ai->ai_addr, ai->ai_addrlen, addr, sizeof(addr), NULL, 0,
 358                        NI_NUMERICHOST) != 0)
 359                xsnprintf(addr, sizeof(addr), "(unknown)");
 360
 361        return addr;
 362}
 363
 364/*
 365 * Returns a connected socket() fd, or else die()s.
 366 */
 367static int git_tcp_connect_sock(char *host, int flags)
 368{
 369        struct strbuf error_message = STRBUF_INIT;
 370        int sockfd = -1;
 371        const char *port = STR(DEFAULT_GIT_PORT);
 372        struct addrinfo hints, *ai0, *ai;
 373        int gai;
 374        int cnt = 0;
 375
 376        get_host_and_port(&host, &port);
 377        if (!*port)
 378                port = "<none>";
 379
 380        memset(&hints, 0, sizeof(hints));
 381        if (flags & CONNECT_IPV4)
 382                hints.ai_family = AF_INET;
 383        else if (flags & CONNECT_IPV6)
 384                hints.ai_family = AF_INET6;
 385        hints.ai_socktype = SOCK_STREAM;
 386        hints.ai_protocol = IPPROTO_TCP;
 387
 388        if (flags & CONNECT_VERBOSE)
 389                fprintf(stderr, "Looking up %s ... ", host);
 390
 391        gai = getaddrinfo(host, port, &hints, &ai);
 392        if (gai)
 393                die("Unable to look up %s (port %s) (%s)", host, port, gai_strerror(gai));
 394
 395        if (flags & CONNECT_VERBOSE)
 396                fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 397
 398        for (ai0 = ai; ai; ai = ai->ai_next, cnt++) {
 399                sockfd = socket(ai->ai_family,
 400                                ai->ai_socktype, ai->ai_protocol);
 401                if ((sockfd < 0) ||
 402                    (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0)) {
 403                        strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 404                                    host, cnt, ai_name(ai), strerror(errno));
 405                        if (0 <= sockfd)
 406                                close(sockfd);
 407                        sockfd = -1;
 408                        continue;
 409                }
 410                if (flags & CONNECT_VERBOSE)
 411                        fprintf(stderr, "%s ", ai_name(ai));
 412                break;
 413        }
 414
 415        freeaddrinfo(ai0);
 416
 417        if (sockfd < 0)
 418                die("unable to connect to %s:\n%s", host, error_message.buf);
 419
 420        enable_keepalive(sockfd);
 421
 422        if (flags & CONNECT_VERBOSE)
 423                fprintf(stderr, "done.\n");
 424
 425        strbuf_release(&error_message);
 426
 427        return sockfd;
 428}
 429
 430#else /* NO_IPV6 */
 431
 432/*
 433 * Returns a connected socket() fd, or else die()s.
 434 */
 435static int git_tcp_connect_sock(char *host, int flags)
 436{
 437        struct strbuf error_message = STRBUF_INIT;
 438        int sockfd = -1;
 439        const char *port = STR(DEFAULT_GIT_PORT);
 440        char *ep;
 441        struct hostent *he;
 442        struct sockaddr_in sa;
 443        char **ap;
 444        unsigned int nport;
 445        int cnt;
 446
 447        get_host_and_port(&host, &port);
 448
 449        if (flags & CONNECT_VERBOSE)
 450                fprintf(stderr, "Looking up %s ... ", host);
 451
 452        he = gethostbyname(host);
 453        if (!he)
 454                die("Unable to look up %s (%s)", host, hstrerror(h_errno));
 455        nport = strtoul(port, &ep, 10);
 456        if ( ep == port || *ep ) {
 457                /* Not numeric */
 458                struct servent *se = getservbyname(port,"tcp");
 459                if ( !se )
 460                        die("Unknown port %s", port);
 461                nport = se->s_port;
 462        }
 463
 464        if (flags & CONNECT_VERBOSE)
 465                fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 466
 467        for (cnt = 0, ap = he->h_addr_list; *ap; ap++, cnt++) {
 468                memset(&sa, 0, sizeof sa);
 469                sa.sin_family = he->h_addrtype;
 470                sa.sin_port = htons(nport);
 471                memcpy(&sa.sin_addr, *ap, he->h_length);
 472
 473                sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 474                if ((sockfd < 0) ||
 475                    connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 476                        strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 477                                host,
 478                                cnt,
 479                                inet_ntoa(*(struct in_addr *)&sa.sin_addr),
 480                                strerror(errno));
 481                        if (0 <= sockfd)
 482                                close(sockfd);
 483                        sockfd = -1;
 484                        continue;
 485                }
 486                if (flags & CONNECT_VERBOSE)
 487                        fprintf(stderr, "%s ",
 488                                inet_ntoa(*(struct in_addr *)&sa.sin_addr));
 489                break;
 490        }
 491
 492        if (sockfd < 0)
 493                die("unable to connect to %s:\n%s", host, error_message.buf);
 494
 495        enable_keepalive(sockfd);
 496
 497        if (flags & CONNECT_VERBOSE)
 498                fprintf(stderr, "done.\n");
 499
 500        return sockfd;
 501}
 502
 503#endif /* NO_IPV6 */
 504
 505
 506static void git_tcp_connect(int fd[2], char *host, int flags)
 507{
 508        int sockfd = git_tcp_connect_sock(host, flags);
 509
 510        fd[0] = sockfd;
 511        fd[1] = dup(sockfd);
 512}
 513
 514
 515static char *git_proxy_command;
 516
 517static int git_proxy_command_options(const char *var, const char *value,
 518                void *cb)
 519{
 520        if (!strcmp(var, "core.gitproxy")) {
 521                const char *for_pos;
 522                int matchlen = -1;
 523                int hostlen;
 524                const char *rhost_name = cb;
 525                int rhost_len = strlen(rhost_name);
 526
 527                if (git_proxy_command)
 528                        return 0;
 529                if (!value)
 530                        return config_error_nonbool(var);
 531                /* [core]
 532                 * ;# matches www.kernel.org as well
 533                 * gitproxy = netcatter-1 for kernel.org
 534                 * gitproxy = netcatter-2 for sample.xz
 535                 * gitproxy = netcatter-default
 536                 */
 537                for_pos = strstr(value, " for ");
 538                if (!for_pos)
 539                        /* matches everybody */
 540                        matchlen = strlen(value);
 541                else {
 542                        hostlen = strlen(for_pos + 5);
 543                        if (rhost_len < hostlen)
 544                                matchlen = -1;
 545                        else if (!strncmp(for_pos + 5,
 546                                          rhost_name + rhost_len - hostlen,
 547                                          hostlen) &&
 548                                 ((rhost_len == hostlen) ||
 549                                  rhost_name[rhost_len - hostlen -1] == '.'))
 550                                matchlen = for_pos - value;
 551                        else
 552                                matchlen = -1;
 553                }
 554                if (0 <= matchlen) {
 555                        /* core.gitproxy = none for kernel.org */
 556                        if (matchlen == 4 &&
 557                            !memcmp(value, "none", 4))
 558                                matchlen = 0;
 559                        git_proxy_command = xmemdupz(value, matchlen);
 560                }
 561                return 0;
 562        }
 563
 564        return git_default_config(var, value, cb);
 565}
 566
 567static int git_use_proxy(const char *host)
 568{
 569        git_proxy_command = getenv("GIT_PROXY_COMMAND");
 570        git_config(git_proxy_command_options, (void*)host);
 571        return (git_proxy_command && *git_proxy_command);
 572}
 573
 574static struct child_process *git_proxy_connect(int fd[2], char *host)
 575{
 576        const char *port = STR(DEFAULT_GIT_PORT);
 577        struct child_process *proxy;
 578
 579        get_host_and_port(&host, &port);
 580
 581        proxy = xmalloc(sizeof(*proxy));
 582        child_process_init(proxy);
 583        argv_array_push(&proxy->args, git_proxy_command);
 584        argv_array_push(&proxy->args, host);
 585        argv_array_push(&proxy->args, port);
 586        proxy->in = -1;
 587        proxy->out = -1;
 588        if (start_command(proxy))
 589                die("cannot start proxy %s", git_proxy_command);
 590        fd[0] = proxy->out; /* read from proxy stdout */
 591        fd[1] = proxy->in;  /* write to proxy stdin */
 592        return proxy;
 593}
 594
 595static char *get_port(char *host)
 596{
 597        char *end;
 598        char *p = strchr(host, ':');
 599
 600        if (p) {
 601                long port = strtol(p + 1, &end, 10);
 602                if (end != p + 1 && *end == '\0' && 0 <= port && port < 65536) {
 603                        *p = '\0';
 604                        return p+1;
 605                }
 606        }
 607
 608        return NULL;
 609}
 610
 611/*
 612 * Extract protocol and relevant parts from the specified connection URL.
 613 * The caller must free() the returned strings.
 614 */
 615static enum protocol parse_connect_url(const char *url_orig, char **ret_host,
 616                                       char **ret_path)
 617{
 618        char *url;
 619        char *host, *path;
 620        char *end;
 621        int separator = '/';
 622        enum protocol protocol = PROTO_LOCAL;
 623
 624        if (is_url(url_orig))
 625                url = url_decode(url_orig);
 626        else
 627                url = xstrdup(url_orig);
 628
 629        host = strstr(url, "://");
 630        if (host) {
 631                *host = '\0';
 632                protocol = get_protocol(url);
 633                host += 3;
 634        } else {
 635                host = url;
 636                if (!url_is_local_not_ssh(url)) {
 637                        protocol = PROTO_SSH;
 638                        separator = ':';
 639                }
 640        }
 641
 642        /*
 643         * Don't do destructive transforms as protocol code does
 644         * '[]' unwrapping in get_host_and_port()
 645         */
 646        end = host_end(&host, 0);
 647
 648        if (protocol == PROTO_LOCAL)
 649                path = end;
 650        else if (protocol == PROTO_FILE && has_dos_drive_prefix(end))
 651                path = end; /* "file://$(pwd)" may be "file://C:/projects/repo" */
 652        else
 653                path = strchr(end, separator);
 654
 655        if (!path || !*path)
 656                die("No path specified. See 'man git-pull' for valid url syntax");
 657
 658        /*
 659         * null-terminate hostname and point path to ~ for URL's like this:
 660         *    ssh://host.xz/~user/repo
 661         */
 662
 663        end = path; /* Need to \0 terminate host here */
 664        if (separator == ':')
 665                path++; /* path starts after ':' */
 666        if (protocol == PROTO_GIT || protocol == PROTO_SSH) {
 667                if (path[1] == '~')
 668                        path++;
 669        }
 670
 671        path = xstrdup(path);
 672        *end = '\0';
 673
 674        *ret_host = xstrdup(host);
 675        *ret_path = path;
 676        free(url);
 677        return protocol;
 678}
 679
 680static struct child_process no_fork = CHILD_PROCESS_INIT;
 681
 682static const char *get_ssh_command(void)
 683{
 684        const char *ssh;
 685
 686        if ((ssh = getenv("GIT_SSH_COMMAND")))
 687                return ssh;
 688
 689        if (!git_config_get_string_const("core.sshcommand", &ssh))
 690                return ssh;
 691
 692        return NULL;
 693}
 694
 695static int override_ssh_variant(int *port_option, int *needs_batch)
 696{
 697        char *variant;
 698
 699        variant = xstrdup_or_null(getenv("GIT_SSH_VARIANT"));
 700        if (!variant &&
 701            git_config_get_string("ssh.variant", &variant))
 702                return 0;
 703
 704        if (!strcmp(variant, "plink") || !strcmp(variant, "putty")) {
 705                *port_option = 'P';
 706                *needs_batch = 0;
 707        } else if (!strcmp(variant, "tortoiseplink")) {
 708                *port_option = 'P';
 709                *needs_batch = 1;
 710        } else {
 711                *port_option = 'p';
 712                *needs_batch = 0;
 713        }
 714        free(variant);
 715        return 1;
 716}
 717
 718static void handle_ssh_variant(const char *ssh_command, int is_cmdline,
 719                               int *port_option, int *needs_batch)
 720{
 721        const char *variant;
 722        char *p = NULL;
 723
 724        if (override_ssh_variant(port_option, needs_batch))
 725                return;
 726
 727        if (!is_cmdline) {
 728                p = xstrdup(ssh_command);
 729                variant = basename(p);
 730        } else {
 731                const char **ssh_argv;
 732
 733                p = xstrdup(ssh_command);
 734                if (split_cmdline(p, &ssh_argv) > 0) {
 735                        variant = basename((char *)ssh_argv[0]);
 736                        /*
 737                         * At this point, variant points into the buffer
 738                         * referenced by p, hence we do not need ssh_argv
 739                         * any longer.
 740                         */
 741                        free(ssh_argv);
 742                } else {
 743                        free(p);
 744                        return;
 745                }
 746        }
 747
 748        if (!strcasecmp(variant, "plink") ||
 749            !strcasecmp(variant, "plink.exe"))
 750                *port_option = 'P';
 751        else if (!strcasecmp(variant, "tortoiseplink") ||
 752                 !strcasecmp(variant, "tortoiseplink.exe")) {
 753                *port_option = 'P';
 754                *needs_batch = 1;
 755        }
 756        free(p);
 757}
 758
 759/*
 760 * This returns a dummy child_process if the transport protocol does not
 761 * need fork(2), or a struct child_process object if it does.  Once done,
 762 * finish the connection with finish_connect() with the value returned from
 763 * this function (it is safe to call finish_connect() with NULL to support
 764 * the former case).
 765 *
 766 * If it returns, the connect is successful; it just dies on errors (this
 767 * will hopefully be changed in a libification effort, to return NULL when
 768 * the connection failed).
 769 */
 770struct child_process *git_connect(int fd[2], const char *url,
 771                                  const char *prog, int flags)
 772{
 773        char *hostandport, *path;
 774        struct child_process *conn = &no_fork;
 775        enum protocol protocol;
 776        struct strbuf cmd = STRBUF_INIT;
 777
 778        /* Without this we cannot rely on waitpid() to tell
 779         * what happened to our children.
 780         */
 781        signal(SIGCHLD, SIG_DFL);
 782
 783        protocol = parse_connect_url(url, &hostandport, &path);
 784        if ((flags & CONNECT_DIAG_URL) && (protocol != PROTO_SSH)) {
 785                printf("Diag: url=%s\n", url ? url : "NULL");
 786                printf("Diag: protocol=%s\n", prot_name(protocol));
 787                printf("Diag: hostandport=%s\n", hostandport ? hostandport : "NULL");
 788                printf("Diag: path=%s\n", path ? path : "NULL");
 789                conn = NULL;
 790        } else if (protocol == PROTO_GIT) {
 791                /*
 792                 * Set up virtual host information based on where we will
 793                 * connect, unless the user has overridden us in
 794                 * the environment.
 795                 */
 796                char *target_host = getenv("GIT_OVERRIDE_VIRTUAL_HOST");
 797                if (target_host)
 798                        target_host = xstrdup(target_host);
 799                else
 800                        target_host = xstrdup(hostandport);
 801
 802                transport_check_allowed("git");
 803
 804                /* These underlying connection commands die() if they
 805                 * cannot connect.
 806                 */
 807                if (git_use_proxy(hostandport))
 808                        conn = git_proxy_connect(fd, hostandport);
 809                else
 810                        git_tcp_connect(fd, hostandport, flags);
 811                /*
 812                 * Separate original protocol components prog and path
 813                 * from extended host header with a NUL byte.
 814                 *
 815                 * Note: Do not add any other headers here!  Doing so
 816                 * will cause older git-daemon servers to crash.
 817                 */
 818                packet_write_fmt(fd[1],
 819                             "%s %s%chost=%s%c",
 820                             prog, path, 0,
 821                             target_host, 0);
 822                free(target_host);
 823        } else {
 824                conn = xmalloc(sizeof(*conn));
 825                child_process_init(conn);
 826
 827                strbuf_addstr(&cmd, prog);
 828                strbuf_addch(&cmd, ' ');
 829                sq_quote_buf(&cmd, path);
 830
 831                /* remove repo-local variables from the environment */
 832                conn->env = local_repo_env;
 833                conn->use_shell = 1;
 834                conn->in = conn->out = -1;
 835                if (protocol == PROTO_SSH) {
 836                        const char *ssh;
 837                        int needs_batch = 0;
 838                        int port_option = 'p';
 839                        char *ssh_host = hostandport;
 840                        const char *port = NULL;
 841                        transport_check_allowed("ssh");
 842                        get_host_and_port(&ssh_host, &port);
 843
 844                        if (!port)
 845                                port = get_port(ssh_host);
 846
 847                        if (flags & CONNECT_DIAG_URL) {
 848                                printf("Diag: url=%s\n", url ? url : "NULL");
 849                                printf("Diag: protocol=%s\n", prot_name(protocol));
 850                                printf("Diag: userandhost=%s\n", ssh_host ? ssh_host : "NULL");
 851                                printf("Diag: port=%s\n", port ? port : "NONE");
 852                                printf("Diag: path=%s\n", path ? path : "NULL");
 853
 854                                free(hostandport);
 855                                free(path);
 856                                free(conn);
 857                                return NULL;
 858                        }
 859
 860                        ssh = get_ssh_command();
 861                        if (ssh)
 862                                handle_ssh_variant(ssh, 1, &port_option,
 863                                                   &needs_batch);
 864                        else {
 865                                /*
 866                                 * GIT_SSH is the no-shell version of
 867                                 * GIT_SSH_COMMAND (and must remain so for
 868                                 * historical compatibility).
 869                                 */
 870                                conn->use_shell = 0;
 871
 872                                ssh = getenv("GIT_SSH");
 873                                if (!ssh)
 874                                        ssh = "ssh";
 875                                else
 876                                        handle_ssh_variant(ssh, 0,
 877                                                           &port_option,
 878                                                           &needs_batch);
 879                        }
 880
 881                        argv_array_push(&conn->args, ssh);
 882                        if (flags & CONNECT_IPV4)
 883                                argv_array_push(&conn->args, "-4");
 884                        else if (flags & CONNECT_IPV6)
 885                                argv_array_push(&conn->args, "-6");
 886                        if (needs_batch)
 887                                argv_array_push(&conn->args, "-batch");
 888                        if (port) {
 889                                argv_array_pushf(&conn->args,
 890                                                 "-%c", port_option);
 891                                argv_array_push(&conn->args, port);
 892                        }
 893                        argv_array_push(&conn->args, ssh_host);
 894                } else {
 895                        transport_check_allowed("file");
 896                }
 897                argv_array_push(&conn->args, cmd.buf);
 898
 899                if (start_command(conn))
 900                        die("unable to fork");
 901
 902                fd[0] = conn->out; /* read from child's stdout */
 903                fd[1] = conn->in;  /* write to child's stdin */
 904                strbuf_release(&cmd);
 905        }
 906        free(hostandport);
 907        free(path);
 908        return conn;
 909}
 910
 911int git_connection_is_socket(struct child_process *conn)
 912{
 913        return conn == &no_fork;
 914}
 915
 916int finish_connect(struct child_process *conn)
 917{
 918        int code;
 919        if (!conn || git_connection_is_socket(conn))
 920                return 0;
 921
 922        code = finish_command(conn);
 923        free(conn);
 924        return code;
 925}