connect.con commit Merge branch 'js/alias-early-config' into maint (040746c)
   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#include "transport.h"
  13
  14static char *server_capabilities;
  15static const char *parse_feature_value(const char *, const char *, int *);
  16
  17static int check_ref(const char *name, unsigned int flags)
  18{
  19        if (!flags)
  20                return 1;
  21
  22        if (!skip_prefix(name, "refs/", &name))
  23                return 0;
  24
  25        /* REF_NORMAL means that we don't want the magic fake tag refs */
  26        if ((flags & REF_NORMAL) && check_refname_format(name, 0))
  27                return 0;
  28
  29        /* REF_HEADS means that we want regular branch heads */
  30        if ((flags & REF_HEADS) && starts_with(name, "heads/"))
  31                return 1;
  32
  33        /* REF_TAGS means that we want tags */
  34        if ((flags & REF_TAGS) && starts_with(name, "tags/"))
  35                return 1;
  36
  37        /* All type bits clear means that we are ok with anything */
  38        return !(flags & ~REF_NORMAL);
  39}
  40
  41int check_ref_type(const struct ref *ref, int flags)
  42{
  43        return check_ref(ref->name, flags);
  44}
  45
  46static void die_initial_contact(int unexpected)
  47{
  48        if (unexpected)
  49                die(_("The remote end hung up upon initial contact"));
  50        else
  51                die(_("Could not read from remote repository.\n\n"
  52                      "Please make sure you have the correct access rights\n"
  53                      "and the repository exists."));
  54}
  55
  56static void parse_one_symref_info(struct string_list *symref, const char *val, int len)
  57{
  58        char *sym, *target;
  59        struct string_list_item *item;
  60
  61        if (!len)
  62                return; /* just "symref" */
  63        /* e.g. "symref=HEAD:refs/heads/master" */
  64        sym = xmemdupz(val, len);
  65        target = strchr(sym, ':');
  66        if (!target)
  67                /* just "symref=something" */
  68                goto reject;
  69        *(target++) = '\0';
  70        if (check_refname_format(sym, REFNAME_ALLOW_ONELEVEL) ||
  71            check_refname_format(target, REFNAME_ALLOW_ONELEVEL))
  72                /* "symref=bogus:pair */
  73                goto reject;
  74        item = string_list_append_nodup(symref, sym);
  75        item->util = target;
  76        return;
  77reject:
  78        free(sym);
  79        return;
  80}
  81
  82static void annotate_refs_with_symref_info(struct ref *ref)
  83{
  84        struct string_list symref = STRING_LIST_INIT_DUP;
  85        const char *feature_list = server_capabilities;
  86
  87        while (feature_list) {
  88                int len;
  89                const char *val;
  90
  91                val = parse_feature_value(feature_list, "symref", &len);
  92                if (!val)
  93                        break;
  94                parse_one_symref_info(&symref, val, len);
  95                feature_list = val + 1;
  96        }
  97        string_list_sort(&symref);
  98
  99        for (; ref; ref = ref->next) {
 100                struct string_list_item *item;
 101                item = string_list_lookup(&symref, ref->name);
 102                if (!item)
 103                        continue;
 104                ref->symref = xstrdup((char *)item->util);
 105        }
 106        string_list_clear(&symref, 0);
 107}
 108
 109/*
 110 * Read all the refs from the other end
 111 */
 112struct ref **get_remote_heads(int in, char *src_buf, size_t src_len,
 113                              struct ref **list, unsigned int flags,
 114                              struct oid_array *extra_have,
 115                              struct oid_array *shallow_points)
 116{
 117        struct ref **orig_list = list;
 118
 119        /*
 120         * A hang-up after seeing some response from the other end
 121         * means that it is unexpected, as we know the other end is
 122         * willing to talk to us.  A hang-up before seeing any
 123         * response does not necessarily mean an ACL problem, though.
 124         */
 125        int saw_response;
 126        int got_dummy_ref_with_capabilities_declaration = 0;
 127
 128        *list = NULL;
 129        for (saw_response = 0; ; saw_response = 1) {
 130                struct ref *ref;
 131                struct object_id old_oid;
 132                char *name;
 133                int len, name_len;
 134                char *buffer = packet_buffer;
 135                const char *arg;
 136
 137                len = packet_read(in, &src_buf, &src_len,
 138                                  packet_buffer, sizeof(packet_buffer),
 139                                  PACKET_READ_GENTLE_ON_EOF |
 140                                  PACKET_READ_CHOMP_NEWLINE);
 141                if (len < 0)
 142                        die_initial_contact(saw_response);
 143
 144                if (!len)
 145                        break;
 146
 147                if (len > 4 && skip_prefix(buffer, "ERR ", &arg))
 148                        die("remote error: %s", arg);
 149
 150                if (len == GIT_SHA1_HEXSZ + strlen("shallow ") &&
 151                        skip_prefix(buffer, "shallow ", &arg)) {
 152                        if (get_oid_hex(arg, &old_oid))
 153                                die("protocol error: expected shallow sha-1, got '%s'", arg);
 154                        if (!shallow_points)
 155                                die("repository on the other end cannot be shallow");
 156                        oid_array_append(shallow_points, &old_oid);
 157                        continue;
 158                }
 159
 160                if (len < GIT_SHA1_HEXSZ + 2 || get_oid_hex(buffer, &old_oid) ||
 161                        buffer[GIT_SHA1_HEXSZ] != ' ')
 162                        die("protocol error: expected sha/ref, got '%s'", buffer);
 163                name = buffer + GIT_SHA1_HEXSZ + 1;
 164
 165                name_len = strlen(name);
 166                if (len != name_len + GIT_SHA1_HEXSZ + 1) {
 167                        free(server_capabilities);
 168                        server_capabilities = xstrdup(name + name_len + 1);
 169                }
 170
 171                if (extra_have && !strcmp(name, ".have")) {
 172                        oid_array_append(extra_have, &old_oid);
 173                        continue;
 174                }
 175
 176                if (!strcmp(name, "capabilities^{}")) {
 177                        if (saw_response)
 178                                die("protocol error: unexpected capabilities^{}");
 179                        if (got_dummy_ref_with_capabilities_declaration)
 180                                die("protocol error: multiple capabilities^{}");
 181                        got_dummy_ref_with_capabilities_declaration = 1;
 182                        continue;
 183                }
 184
 185                if (!check_ref(name, flags))
 186                        continue;
 187
 188                if (got_dummy_ref_with_capabilities_declaration)
 189                        die("protocol error: unexpected ref after capabilities^{}");
 190
 191                ref = alloc_ref(buffer + GIT_SHA1_HEXSZ + 1);
 192                oidcpy(&ref->old_oid, &old_oid);
 193                *list = ref;
 194                list = &ref->next;
 195        }
 196
 197        annotate_refs_with_symref_info(*orig_list);
 198
 199        return list;
 200}
 201
 202static const char *parse_feature_value(const char *feature_list, const char *feature, int *lenp)
 203{
 204        int len;
 205
 206        if (!feature_list)
 207                return NULL;
 208
 209        len = strlen(feature);
 210        while (*feature_list) {
 211                const char *found = strstr(feature_list, feature);
 212                if (!found)
 213                        return NULL;
 214                if (feature_list == found || isspace(found[-1])) {
 215                        const char *value = found + len;
 216                        /* feature with no value (e.g., "thin-pack") */
 217                        if (!*value || isspace(*value)) {
 218                                if (lenp)
 219                                        *lenp = 0;
 220                                return value;
 221                        }
 222                        /* feature with a value (e.g., "agent=git/1.2.3") */
 223                        else if (*value == '=') {
 224                                value++;
 225                                if (lenp)
 226                                        *lenp = strcspn(value, " \t\n");
 227                                return value;
 228                        }
 229                        /*
 230                         * otherwise we matched a substring of another feature;
 231                         * keep looking
 232                         */
 233                }
 234                feature_list = found + 1;
 235        }
 236        return NULL;
 237}
 238
 239int parse_feature_request(const char *feature_list, const char *feature)
 240{
 241        return !!parse_feature_value(feature_list, feature, NULL);
 242}
 243
 244const char *server_feature_value(const char *feature, int *len)
 245{
 246        return parse_feature_value(server_capabilities, feature, len);
 247}
 248
 249int server_supports(const char *feature)
 250{
 251        return !!server_feature_value(feature, NULL);
 252}
 253
 254enum protocol {
 255        PROTO_LOCAL = 1,
 256        PROTO_FILE,
 257        PROTO_SSH,
 258        PROTO_GIT
 259};
 260
 261int url_is_local_not_ssh(const char *url)
 262{
 263        const char *colon = strchr(url, ':');
 264        const char *slash = strchr(url, '/');
 265        return !colon || (slash && slash < colon) ||
 266                has_dos_drive_prefix(url);
 267}
 268
 269static const char *prot_name(enum protocol protocol)
 270{
 271        switch (protocol) {
 272                case PROTO_LOCAL:
 273                case PROTO_FILE:
 274                        return "file";
 275                case PROTO_SSH:
 276                        return "ssh";
 277                case PROTO_GIT:
 278                        return "git";
 279                default:
 280                        return "unknown protocol";
 281        }
 282}
 283
 284static enum protocol get_protocol(const char *name)
 285{
 286        if (!strcmp(name, "ssh"))
 287                return PROTO_SSH;
 288        if (!strcmp(name, "git"))
 289                return PROTO_GIT;
 290        if (!strcmp(name, "git+ssh")) /* deprecated - do not use */
 291                return PROTO_SSH;
 292        if (!strcmp(name, "ssh+git")) /* deprecated - do not use */
 293                return PROTO_SSH;
 294        if (!strcmp(name, "file"))
 295                return PROTO_FILE;
 296        die("I don't handle protocol '%s'", name);
 297}
 298
 299static char *host_end(char **hoststart, int removebrackets)
 300{
 301        char *host = *hoststart;
 302        char *end;
 303        char *start = strstr(host, "@[");
 304        if (start)
 305                start++; /* Jump over '@' */
 306        else
 307                start = host;
 308        if (start[0] == '[') {
 309                end = strchr(start + 1, ']');
 310                if (end) {
 311                        if (removebrackets) {
 312                                *end = 0;
 313                                memmove(start, start + 1, end - start);
 314                                end++;
 315                        }
 316                } else
 317                        end = host;
 318        } else
 319                end = host;
 320        return end;
 321}
 322
 323#define STR_(s) # s
 324#define STR(s)  STR_(s)
 325
 326static void get_host_and_port(char **host, const char **port)
 327{
 328        char *colon, *end;
 329        end = host_end(host, 1);
 330        colon = strchr(end, ':');
 331        if (colon) {
 332                long portnr = strtol(colon + 1, &end, 10);
 333                if (end != colon + 1 && *end == '\0' && 0 <= portnr && portnr < 65536) {
 334                        *colon = 0;
 335                        *port = colon + 1;
 336                } else if (!colon[1]) {
 337                        *colon = 0;
 338                }
 339        }
 340}
 341
 342static void enable_keepalive(int sockfd)
 343{
 344        int ka = 1;
 345
 346        if (setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, &ka, sizeof(ka)) < 0)
 347                fprintf(stderr, "unable to set SO_KEEPALIVE on socket: %s\n",
 348                        strerror(errno));
 349}
 350
 351#ifndef NO_IPV6
 352
 353static const char *ai_name(const struct addrinfo *ai)
 354{
 355        static char addr[NI_MAXHOST];
 356        if (getnameinfo(ai->ai_addr, ai->ai_addrlen, addr, sizeof(addr), NULL, 0,
 357                        NI_NUMERICHOST) != 0)
 358                xsnprintf(addr, sizeof(addr), "(unknown)");
 359
 360        return addr;
 361}
 362
 363/*
 364 * Returns a connected socket() fd, or else die()s.
 365 */
 366static int git_tcp_connect_sock(char *host, int flags)
 367{
 368        struct strbuf error_message = STRBUF_INIT;
 369        int sockfd = -1;
 370        const char *port = STR(DEFAULT_GIT_PORT);
 371        struct addrinfo hints, *ai0, *ai;
 372        int gai;
 373        int cnt = 0;
 374
 375        get_host_and_port(&host, &port);
 376        if (!*port)
 377                port = "<none>";
 378
 379        memset(&hints, 0, sizeof(hints));
 380        if (flags & CONNECT_IPV4)
 381                hints.ai_family = AF_INET;
 382        else if (flags & CONNECT_IPV6)
 383                hints.ai_family = AF_INET6;
 384        hints.ai_socktype = SOCK_STREAM;
 385        hints.ai_protocol = IPPROTO_TCP;
 386
 387        if (flags & CONNECT_VERBOSE)
 388                fprintf(stderr, "Looking up %s ... ", host);
 389
 390        gai = getaddrinfo(host, port, &hints, &ai);
 391        if (gai)
 392                die("Unable to look up %s (port %s) (%s)", host, port, gai_strerror(gai));
 393
 394        if (flags & CONNECT_VERBOSE)
 395                fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 396
 397        for (ai0 = ai; ai; ai = ai->ai_next, cnt++) {
 398                sockfd = socket(ai->ai_family,
 399                                ai->ai_socktype, ai->ai_protocol);
 400                if ((sockfd < 0) ||
 401                    (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0)) {
 402                        strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 403                                    host, cnt, ai_name(ai), strerror(errno));
 404                        if (0 <= sockfd)
 405                                close(sockfd);
 406                        sockfd = -1;
 407                        continue;
 408                }
 409                if (flags & CONNECT_VERBOSE)
 410                        fprintf(stderr, "%s ", ai_name(ai));
 411                break;
 412        }
 413
 414        freeaddrinfo(ai0);
 415
 416        if (sockfd < 0)
 417                die("unable to connect to %s:\n%s", host, error_message.buf);
 418
 419        enable_keepalive(sockfd);
 420
 421        if (flags & CONNECT_VERBOSE)
 422                fprintf(stderr, "done.\n");
 423
 424        strbuf_release(&error_message);
 425
 426        return sockfd;
 427}
 428
 429#else /* NO_IPV6 */
 430
 431/*
 432 * Returns a connected socket() fd, or else die()s.
 433 */
 434static int git_tcp_connect_sock(char *host, int flags)
 435{
 436        struct strbuf error_message = STRBUF_INIT;
 437        int sockfd = -1;
 438        const char *port = STR(DEFAULT_GIT_PORT);
 439        char *ep;
 440        struct hostent *he;
 441        struct sockaddr_in sa;
 442        char **ap;
 443        unsigned int nport;
 444        int cnt;
 445
 446        get_host_and_port(&host, &port);
 447
 448        if (flags & CONNECT_VERBOSE)
 449                fprintf(stderr, "Looking up %s ... ", host);
 450
 451        he = gethostbyname(host);
 452        if (!he)
 453                die("Unable to look up %s (%s)", host, hstrerror(h_errno));
 454        nport = strtoul(port, &ep, 10);
 455        if ( ep == port || *ep ) {
 456                /* Not numeric */
 457                struct servent *se = getservbyname(port,"tcp");
 458                if ( !se )
 459                        die("Unknown port %s", port);
 460                nport = se->s_port;
 461        }
 462
 463        if (flags & CONNECT_VERBOSE)
 464                fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 465
 466        for (cnt = 0, ap = he->h_addr_list; *ap; ap++, cnt++) {
 467                memset(&sa, 0, sizeof sa);
 468                sa.sin_family = he->h_addrtype;
 469                sa.sin_port = htons(nport);
 470                memcpy(&sa.sin_addr, *ap, he->h_length);
 471
 472                sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 473                if ((sockfd < 0) ||
 474                    connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 475                        strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 476                                host,
 477                                cnt,
 478                                inet_ntoa(*(struct in_addr *)&sa.sin_addr),
 479                                strerror(errno));
 480                        if (0 <= sockfd)
 481                                close(sockfd);
 482                        sockfd = -1;
 483                        continue;
 484                }
 485                if (flags & CONNECT_VERBOSE)
 486                        fprintf(stderr, "%s ",
 487                                inet_ntoa(*(struct in_addr *)&sa.sin_addr));
 488                break;
 489        }
 490
 491        if (sockfd < 0)
 492                die("unable to connect to %s:\n%s", host, error_message.buf);
 493
 494        enable_keepalive(sockfd);
 495
 496        if (flags & CONNECT_VERBOSE)
 497                fprintf(stderr, "done.\n");
 498
 499        return sockfd;
 500}
 501
 502#endif /* NO_IPV6 */
 503
 504
 505static void git_tcp_connect(int fd[2], char *host, int flags)
 506{
 507        int sockfd = git_tcp_connect_sock(host, flags);
 508
 509        fd[0] = sockfd;
 510        fd[1] = dup(sockfd);
 511}
 512
 513
 514static char *git_proxy_command;
 515
 516static int git_proxy_command_options(const char *var, const char *value,
 517                void *cb)
 518{
 519        if (!strcmp(var, "core.gitproxy")) {
 520                const char *for_pos;
 521                int matchlen = -1;
 522                int hostlen;
 523                const char *rhost_name = cb;
 524                int rhost_len = strlen(rhost_name);
 525
 526                if (git_proxy_command)
 527                        return 0;
 528                if (!value)
 529                        return config_error_nonbool(var);
 530                /* [core]
 531                 * ;# matches www.kernel.org as well
 532                 * gitproxy = netcatter-1 for kernel.org
 533                 * gitproxy = netcatter-2 for sample.xz
 534                 * gitproxy = netcatter-default
 535                 */
 536                for_pos = strstr(value, " for ");
 537                if (!for_pos)
 538                        /* matches everybody */
 539                        matchlen = strlen(value);
 540                else {
 541                        hostlen = strlen(for_pos + 5);
 542                        if (rhost_len < hostlen)
 543                                matchlen = -1;
 544                        else if (!strncmp(for_pos + 5,
 545                                          rhost_name + rhost_len - hostlen,
 546                                          hostlen) &&
 547                                 ((rhost_len == hostlen) ||
 548                                  rhost_name[rhost_len - hostlen -1] == '.'))
 549                                matchlen = for_pos - value;
 550                        else
 551                                matchlen = -1;
 552                }
 553                if (0 <= matchlen) {
 554                        /* core.gitproxy = none for kernel.org */
 555                        if (matchlen == 4 &&
 556                            !memcmp(value, "none", 4))
 557                                matchlen = 0;
 558                        git_proxy_command = xmemdupz(value, matchlen);
 559                }
 560                return 0;
 561        }
 562
 563        return git_default_config(var, value, cb);
 564}
 565
 566static int git_use_proxy(const char *host)
 567{
 568        git_proxy_command = getenv("GIT_PROXY_COMMAND");
 569        git_config(git_proxy_command_options, (void*)host);
 570        return (git_proxy_command && *git_proxy_command);
 571}
 572
 573static struct child_process *git_proxy_connect(int fd[2], char *host)
 574{
 575        const char *port = STR(DEFAULT_GIT_PORT);
 576        struct child_process *proxy;
 577
 578        get_host_and_port(&host, &port);
 579
 580        proxy = xmalloc(sizeof(*proxy));
 581        child_process_init(proxy);
 582        argv_array_push(&proxy->args, git_proxy_command);
 583        argv_array_push(&proxy->args, host);
 584        argv_array_push(&proxy->args, port);
 585        proxy->in = -1;
 586        proxy->out = -1;
 587        if (start_command(proxy))
 588                die("cannot start proxy %s", git_proxy_command);
 589        fd[0] = proxy->out; /* read from proxy stdout */
 590        fd[1] = proxy->in;  /* write to proxy stdin */
 591        return proxy;
 592}
 593
 594static char *get_port(char *host)
 595{
 596        char *end;
 597        char *p = strchr(host, ':');
 598
 599        if (p) {
 600                long port = strtol(p + 1, &end, 10);
 601                if (end != p + 1 && *end == '\0' && 0 <= port && port < 65536) {
 602                        *p = '\0';
 603                        return p+1;
 604                }
 605        }
 606
 607        return NULL;
 608}
 609
 610/*
 611 * Extract protocol and relevant parts from the specified connection URL.
 612 * The caller must free() the returned strings.
 613 */
 614static enum protocol parse_connect_url(const char *url_orig, char **ret_host,
 615                                       char **ret_path)
 616{
 617        char *url;
 618        char *host, *path;
 619        char *end;
 620        int separator = '/';
 621        enum protocol protocol = PROTO_LOCAL;
 622
 623        if (is_url(url_orig))
 624                url = url_decode(url_orig);
 625        else
 626                url = xstrdup(url_orig);
 627
 628        host = strstr(url, "://");
 629        if (host) {
 630                *host = '\0';
 631                protocol = get_protocol(url);
 632                host += 3;
 633        } else {
 634                host = url;
 635                if (!url_is_local_not_ssh(url)) {
 636                        protocol = PROTO_SSH;
 637                        separator = ':';
 638                }
 639        }
 640
 641        /*
 642         * Don't do destructive transforms as protocol code does
 643         * '[]' unwrapping in get_host_and_port()
 644         */
 645        end = host_end(&host, 0);
 646
 647        if (protocol == PROTO_LOCAL)
 648                path = end;
 649        else if (protocol == PROTO_FILE && has_dos_drive_prefix(end))
 650                path = end; /* "file://$(pwd)" may be "file://C:/projects/repo" */
 651        else
 652                path = strchr(end, separator);
 653
 654        if (!path || !*path)
 655                die("No path specified. See 'man git-pull' for valid url syntax");
 656
 657        /*
 658         * null-terminate hostname and point path to ~ for URL's like this:
 659         *    ssh://host.xz/~user/repo
 660         */
 661
 662        end = path; /* Need to \0 terminate host here */
 663        if (separator == ':')
 664                path++; /* path starts after ':' */
 665        if (protocol == PROTO_GIT || protocol == PROTO_SSH) {
 666                if (path[1] == '~')
 667                        path++;
 668        }
 669
 670        path = xstrdup(path);
 671        *end = '\0';
 672
 673        *ret_host = xstrdup(host);
 674        *ret_path = path;
 675        free(url);
 676        return protocol;
 677}
 678
 679static struct child_process no_fork = CHILD_PROCESS_INIT;
 680
 681static const char *get_ssh_command(void)
 682{
 683        const char *ssh;
 684
 685        if ((ssh = getenv("GIT_SSH_COMMAND")))
 686                return ssh;
 687
 688        if (!git_config_get_string_const("core.sshcommand", &ssh))
 689                return ssh;
 690
 691        return NULL;
 692}
 693
 694static int override_ssh_variant(int *port_option, int *needs_batch)
 695{
 696        char *variant;
 697
 698        variant = xstrdup_or_null(getenv("GIT_SSH_VARIANT"));
 699        if (!variant &&
 700            git_config_get_string("ssh.variant", &variant))
 701                return 0;
 702
 703        if (!strcmp(variant, "plink") || !strcmp(variant, "putty")) {
 704                *port_option = 'P';
 705                *needs_batch = 0;
 706        } else if (!strcmp(variant, "tortoiseplink")) {
 707                *port_option = 'P';
 708                *needs_batch = 1;
 709        } else {
 710                *port_option = 'p';
 711                *needs_batch = 0;
 712        }
 713        free(variant);
 714        return 1;
 715}
 716
 717static void handle_ssh_variant(const char *ssh_command, int is_cmdline,
 718                               int *port_option, int *needs_batch)
 719{
 720        const char *variant;
 721        char *p = NULL;
 722
 723        if (override_ssh_variant(port_option, needs_batch))
 724                return;
 725
 726        if (!is_cmdline) {
 727                p = xstrdup(ssh_command);
 728                variant = basename(p);
 729        } else {
 730                const char **ssh_argv;
 731
 732                p = xstrdup(ssh_command);
 733                if (split_cmdline(p, &ssh_argv) > 0) {
 734                        variant = basename((char *)ssh_argv[0]);
 735                        /*
 736                         * At this point, variant points into the buffer
 737                         * referenced by p, hence we do not need ssh_argv
 738                         * any longer.
 739                         */
 740                        free(ssh_argv);
 741                } else {
 742                        free(p);
 743                        return;
 744                }
 745        }
 746
 747        if (!strcasecmp(variant, "plink") ||
 748            !strcasecmp(variant, "plink.exe"))
 749                *port_option = 'P';
 750        else if (!strcasecmp(variant, "tortoiseplink") ||
 751                 !strcasecmp(variant, "tortoiseplink.exe")) {
 752                *port_option = 'P';
 753                *needs_batch = 1;
 754        }
 755        free(p);
 756}
 757
 758/*
 759 * This returns a dummy child_process if the transport protocol does not
 760 * need fork(2), or a struct child_process object if it does.  Once done,
 761 * finish the connection with finish_connect() with the value returned from
 762 * this function (it is safe to call finish_connect() with NULL to support
 763 * the former case).
 764 *
 765 * If it returns, the connect is successful; it just dies on errors (this
 766 * will hopefully be changed in a libification effort, to return NULL when
 767 * the connection failed).
 768 */
 769struct child_process *git_connect(int fd[2], const char *url,
 770                                  const char *prog, int flags)
 771{
 772        char *hostandport, *path;
 773        struct child_process *conn = &no_fork;
 774        enum protocol protocol;
 775        struct strbuf cmd = STRBUF_INIT;
 776
 777        /* Without this we cannot rely on waitpid() to tell
 778         * what happened to our children.
 779         */
 780        signal(SIGCHLD, SIG_DFL);
 781
 782        protocol = parse_connect_url(url, &hostandport, &path);
 783        if ((flags & CONNECT_DIAG_URL) && (protocol != PROTO_SSH)) {
 784                printf("Diag: url=%s\n", url ? url : "NULL");
 785                printf("Diag: protocol=%s\n", prot_name(protocol));
 786                printf("Diag: hostandport=%s\n", hostandport ? hostandport : "NULL");
 787                printf("Diag: path=%s\n", path ? path : "NULL");
 788                conn = NULL;
 789        } else if (protocol == PROTO_GIT) {
 790                /*
 791                 * Set up virtual host information based on where we will
 792                 * connect, unless the user has overridden us in
 793                 * the environment.
 794                 */
 795                char *target_host = getenv("GIT_OVERRIDE_VIRTUAL_HOST");
 796                if (target_host)
 797                        target_host = xstrdup(target_host);
 798                else
 799                        target_host = xstrdup(hostandport);
 800
 801                transport_check_allowed("git");
 802
 803                /* These underlying connection commands die() if they
 804                 * cannot connect.
 805                 */
 806                if (git_use_proxy(hostandport))
 807                        conn = git_proxy_connect(fd, hostandport);
 808                else
 809                        git_tcp_connect(fd, hostandport, flags);
 810                /*
 811                 * Separate original protocol components prog and path
 812                 * from extended host header with a NUL byte.
 813                 *
 814                 * Note: Do not add any other headers here!  Doing so
 815                 * will cause older git-daemon servers to crash.
 816                 */
 817                packet_write_fmt(fd[1],
 818                             "%s %s%chost=%s%c",
 819                             prog, path, 0,
 820                             target_host, 0);
 821                free(target_host);
 822        } else {
 823                conn = xmalloc(sizeof(*conn));
 824                child_process_init(conn);
 825
 826                strbuf_addstr(&cmd, prog);
 827                strbuf_addch(&cmd, ' ');
 828                sq_quote_buf(&cmd, path);
 829
 830                /* remove repo-local variables from the environment */
 831                conn->env = local_repo_env;
 832                conn->use_shell = 1;
 833                conn->in = conn->out = -1;
 834                if (protocol == PROTO_SSH) {
 835                        const char *ssh;
 836                        int needs_batch = 0;
 837                        int port_option = 'p';
 838                        char *ssh_host = hostandport;
 839                        const char *port = NULL;
 840                        transport_check_allowed("ssh");
 841                        get_host_and_port(&ssh_host, &port);
 842
 843                        if (!port)
 844                                port = get_port(ssh_host);
 845
 846                        if (flags & CONNECT_DIAG_URL) {
 847                                printf("Diag: url=%s\n", url ? url : "NULL");
 848                                printf("Diag: protocol=%s\n", prot_name(protocol));
 849                                printf("Diag: userandhost=%s\n", ssh_host ? ssh_host : "NULL");
 850                                printf("Diag: port=%s\n", port ? port : "NONE");
 851                                printf("Diag: path=%s\n", path ? path : "NULL");
 852
 853                                free(hostandport);
 854                                free(path);
 855                                free(conn);
 856                                return NULL;
 857                        }
 858
 859                        ssh = get_ssh_command();
 860                        if (ssh)
 861                                handle_ssh_variant(ssh, 1, &port_option,
 862                                                   &needs_batch);
 863                        else {
 864                                /*
 865                                 * GIT_SSH is the no-shell version of
 866                                 * GIT_SSH_COMMAND (and must remain so for
 867                                 * historical compatibility).
 868                                 */
 869                                conn->use_shell = 0;
 870
 871                                ssh = getenv("GIT_SSH");
 872                                if (!ssh)
 873                                        ssh = "ssh";
 874                                else
 875                                        handle_ssh_variant(ssh, 0,
 876                                                           &port_option,
 877                                                           &needs_batch);
 878                        }
 879
 880                        argv_array_push(&conn->args, ssh);
 881                        if (flags & CONNECT_IPV4)
 882                                argv_array_push(&conn->args, "-4");
 883                        else if (flags & CONNECT_IPV6)
 884                                argv_array_push(&conn->args, "-6");
 885                        if (needs_batch)
 886                                argv_array_push(&conn->args, "-batch");
 887                        if (port) {
 888                                argv_array_pushf(&conn->args,
 889                                                 "-%c", port_option);
 890                                argv_array_push(&conn->args, port);
 891                        }
 892                        argv_array_push(&conn->args, ssh_host);
 893                } else {
 894                        transport_check_allowed("file");
 895                }
 896                argv_array_push(&conn->args, cmd.buf);
 897
 898                if (start_command(conn))
 899                        die("unable to fork");
 900
 901                fd[0] = conn->out; /* read from child's stdout */
 902                fd[1] = conn->in;  /* write to child's stdin */
 903                strbuf_release(&cmd);
 904        }
 905        free(hostandport);
 906        free(path);
 907        return conn;
 908}
 909
 910int git_connection_is_socket(struct child_process *conn)
 911{
 912        return conn == &no_fork;
 913}
 914
 915int finish_connect(struct child_process *conn)
 916{
 917        int code;
 918        if (!conn || git_connection_is_socket(conn))
 919                return 0;
 920
 921        code = finish_command(conn);
 922        free(conn);
 923        return code;
 924}