Andrew's git / gitweb.git / connect.c
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connect.con commit t6041: do not compress backup tar file (f5ee54a)
   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 got_at_least_one_head)
  47{
  48        if (got_at_least_one_head)
  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(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 sha1_array *extra_have,
 115                              struct sha1_array *shallow_points)
 116{
 117        struct ref **orig_list = list;
 118        int got_at_least_one_head = 0;
 119
 120        *list = NULL;
 121        for (;;) {
 122                struct ref *ref;
 123                unsigned char old_sha1[20];
 124                char *name;
 125                int len, name_len;
 126                char *buffer = packet_buffer;
 127                const char *arg;
 128
 129                len = packet_read(in, &src_buf, &src_len,
 130                                  packet_buffer, sizeof(packet_buffer),
 131                                  PACKET_READ_GENTLE_ON_EOF |
 132                                  PACKET_READ_CHOMP_NEWLINE);
 133                if (len < 0)
 134                        die_initial_contact(got_at_least_one_head);
 135
 136                if (!len)
 137                        break;
 138
 139                if (len > 4 && skip_prefix(buffer, "ERR ", &arg))
 140                        die("remote error: %s", arg);
 141
 142                if (len == 48 && skip_prefix(buffer, "shallow ", &arg)) {
 143                        if (get_sha1_hex(arg, old_sha1))
 144                                die("protocol error: expected shallow sha-1, got '%s'", arg);
 145                        if (!shallow_points)
 146                                die("repository on the other end cannot be shallow");
 147                        sha1_array_append(shallow_points, old_sha1);
 148                        continue;
 149                }
 150
 151                if (len < 42 || get_sha1_hex(buffer, old_sha1) || buffer[40] != ' ')
 152                        die("protocol error: expected sha/ref, got '%s'", buffer);
 153                name = buffer + 41;
 154
 155                name_len = strlen(name);
 156                if (len != name_len + 41) {
 157                        free(server_capabilities);
 158                        server_capabilities = xstrdup(name + name_len + 1);
 159                }
 160
 161                if (extra_have && !strcmp(name, ".have")) {
 162                        sha1_array_append(extra_have, old_sha1);
 163                        continue;
 164                }
 165
 166                if (!check_ref(name, flags))
 167                        continue;
 168                ref = alloc_ref(buffer + 41);
 169                hashcpy(ref->old_sha1, old_sha1);
 170                *list = ref;
 171                list = &ref->next;
 172                got_at_least_one_head = 1;
 173        }
 174
 175        annotate_refs_with_symref_info(*orig_list);
 176
 177        return list;
 178}
 179
 180static const char *parse_feature_value(const char *feature_list, const char *feature, int *lenp)
 181{
 182        int len;
 183
 184        if (!feature_list)
 185                return NULL;
 186
 187        len = strlen(feature);
 188        while (*feature_list) {
 189                const char *found = strstr(feature_list, feature);
 190                if (!found)
 191                        return NULL;
 192                if (feature_list == found || isspace(found[-1])) {
 193                        const char *value = found + len;
 194                        /* feature with no value (e.g., "thin-pack") */
 195                        if (!*value || isspace(*value)) {
 196                                if (lenp)
 197                                        *lenp = 0;
 198                                return value;
 199                        }
 200                        /* feature with a value (e.g., "agent=git/1.2.3") */
 201                        else if (*value == '=') {
 202                                value++;
 203                                if (lenp)
 204                                        *lenp = strcspn(value, " \t\n");
 205                                return value;
 206                        }
 207                        /*
 208                         * otherwise we matched a substring of another feature;
 209                         * keep looking
 210                         */
 211                }
 212                feature_list = found + 1;
 213        }
 214        return NULL;
 215}
 216
 217int parse_feature_request(const char *feature_list, const char *feature)
 218{
 219        return !!parse_feature_value(feature_list, feature, NULL);
 220}
 221
 222const char *server_feature_value(const char *feature, int *len)
 223{
 224        return parse_feature_value(server_capabilities, feature, len);
 225}
 226
 227int server_supports(const char *feature)
 228{
 229        return !!server_feature_value(feature, NULL);
 230}
 231
 232enum protocol {
 233        PROTO_LOCAL = 1,
 234        PROTO_FILE,
 235        PROTO_SSH,
 236        PROTO_GIT
 237};
 238
 239int url_is_local_not_ssh(const char *url)
 240{
 241        const char *colon = strchr(url, ':');
 242        const char *slash = strchr(url, '/');
 243        return !colon || (slash && slash < colon) ||
 244                has_dos_drive_prefix(url);
 245}
 246
 247static const char *prot_name(enum protocol protocol)
 248{
 249        switch (protocol) {
 250                case PROTO_LOCAL:
 251                case PROTO_FILE:
 252                        return "file";
 253                case PROTO_SSH:
 254                        return "ssh";
 255                case PROTO_GIT:
 256                        return "git";
 257                default:
 258                        return "unkown protocol";
 259        }
 260}
 261
 262static enum protocol get_protocol(const char *name)
 263{
 264        if (!strcmp(name, "ssh"))
 265                return PROTO_SSH;
 266        if (!strcmp(name, "git"))
 267                return PROTO_GIT;
 268        if (!strcmp(name, "git+ssh"))
 269                return PROTO_SSH;
 270        if (!strcmp(name, "ssh+git"))
 271                return PROTO_SSH;
 272        if (!strcmp(name, "file"))
 273                return PROTO_FILE;
 274        die("I don't handle protocol '%s'", name);
 275}
 276
 277static char *host_end(char **hoststart, int removebrackets)
 278{
 279        char *host = *hoststart;
 280        char *end;
 281        char *start = strstr(host, "@[");
 282        if (start)
 283                start++; /* Jump over '@' */
 284        else
 285                start = host;
 286        if (start[0] == '[') {
 287                end = strchr(start + 1, ']');
 288                if (end) {
 289                        if (removebrackets) {
 290                                *end = 0;
 291                                memmove(start, start + 1, end - start);
 292                                end++;
 293                        }
 294                } else
 295                        end = host;
 296        } else
 297                end = host;
 298        return end;
 299}
 300
 301#define STR_(s) # s
 302#define STR(s)  STR_(s)
 303
 304static void get_host_and_port(char **host, const char **port)
 305{
 306        char *colon, *end;
 307        end = host_end(host, 1);
 308        colon = strchr(end, ':');
 309        if (colon) {
 310                long portnr = strtol(colon + 1, &end, 10);
 311                if (end != colon + 1 && *end == '\0' && 0 <= portnr && portnr < 65536) {
 312                        *colon = 0;
 313                        *port = colon + 1;
 314                } else if (!colon[1]) {
 315                        *colon = 0;
 316                }
 317        }
 318}
 319
 320static void enable_keepalive(int sockfd)
 321{
 322        int ka = 1;
 323
 324        if (setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, &ka, sizeof(ka)) < 0)
 325                fprintf(stderr, "unable to set SO_KEEPALIVE on socket: %s\n",
 326                        strerror(errno));
 327}
 328
 329#ifndef NO_IPV6
 330
 331static const char *ai_name(const struct addrinfo *ai)
 332{
 333        static char addr[NI_MAXHOST];
 334        if (getnameinfo(ai->ai_addr, ai->ai_addrlen, addr, sizeof(addr), NULL, 0,
 335                        NI_NUMERICHOST) != 0)
 336                strcpy(addr, "(unknown)");
 337
 338        return addr;
 339}
 340
 341/*
 342 * Returns a connected socket() fd, or else die()s.
 343 */
 344static int git_tcp_connect_sock(char *host, int flags)
 345{
 346        struct strbuf error_message = STRBUF_INIT;
 347        int sockfd = -1;
 348        const char *port = STR(DEFAULT_GIT_PORT);
 349        struct addrinfo hints, *ai0, *ai;
 350        int gai;
 351        int cnt = 0;
 352
 353        get_host_and_port(&host, &port);
 354        if (!*port)
 355                port = "<none>";
 356
 357        memset(&hints, 0, sizeof(hints));
 358        hints.ai_socktype = SOCK_STREAM;
 359        hints.ai_protocol = IPPROTO_TCP;
 360
 361        if (flags & CONNECT_VERBOSE)
 362                fprintf(stderr, "Looking up %s ... ", host);
 363
 364        gai = getaddrinfo(host, port, &hints, &ai);
 365        if (gai)
 366                die("Unable to look up %s (port %s) (%s)", host, port, gai_strerror(gai));
 367
 368        if (flags & CONNECT_VERBOSE)
 369                fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 370
 371        for (ai0 = ai; ai; ai = ai->ai_next, cnt++) {
 372                sockfd = socket(ai->ai_family,
 373                                ai->ai_socktype, ai->ai_protocol);
 374                if ((sockfd < 0) ||
 375                    (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0)) {
 376                        strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 377                                    host, cnt, ai_name(ai), strerror(errno));
 378                        if (0 <= sockfd)
 379                                close(sockfd);
 380                        sockfd = -1;
 381                        continue;
 382                }
 383                if (flags & CONNECT_VERBOSE)
 384                        fprintf(stderr, "%s ", ai_name(ai));
 385                break;
 386        }
 387
 388        freeaddrinfo(ai0);
 389
 390        if (sockfd < 0)
 391                die("unable to connect to %s:\n%s", host, error_message.buf);
 392
 393        enable_keepalive(sockfd);
 394
 395        if (flags & CONNECT_VERBOSE)
 396                fprintf(stderr, "done.\n");
 397
 398        strbuf_release(&error_message);
 399
 400        return sockfd;
 401}
 402
 403#else /* NO_IPV6 */
 404
 405/*
 406 * Returns a connected socket() fd, or else die()s.
 407 */
 408static int git_tcp_connect_sock(char *host, int flags)
 409{
 410        struct strbuf error_message = STRBUF_INIT;
 411        int sockfd = -1;
 412        const char *port = STR(DEFAULT_GIT_PORT);
 413        char *ep;
 414        struct hostent *he;
 415        struct sockaddr_in sa;
 416        char **ap;
 417        unsigned int nport;
 418        int cnt;
 419
 420        get_host_and_port(&host, &port);
 421
 422        if (flags & CONNECT_VERBOSE)
 423                fprintf(stderr, "Looking up %s ... ", host);
 424
 425        he = gethostbyname(host);
 426        if (!he)
 427                die("Unable to look up %s (%s)", host, hstrerror(h_errno));
 428        nport = strtoul(port, &ep, 10);
 429        if ( ep == port || *ep ) {
 430                /* Not numeric */
 431                struct servent *se = getservbyname(port,"tcp");
 432                if ( !se )
 433                        die("Unknown port %s", port);
 434                nport = se->s_port;
 435        }
 436
 437        if (flags & CONNECT_VERBOSE)
 438                fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 439
 440        for (cnt = 0, ap = he->h_addr_list; *ap; ap++, cnt++) {
 441                memset(&sa, 0, sizeof sa);
 442                sa.sin_family = he->h_addrtype;
 443                sa.sin_port = htons(nport);
 444                memcpy(&sa.sin_addr, *ap, he->h_length);
 445
 446                sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 447                if ((sockfd < 0) ||
 448                    connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 449                        strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 450                                host,
 451                                cnt,
 452                                inet_ntoa(*(struct in_addr *)&sa.sin_addr),
 453                                strerror(errno));
 454                        if (0 <= sockfd)
 455                                close(sockfd);
 456                        sockfd = -1;
 457                        continue;
 458                }
 459                if (flags & CONNECT_VERBOSE)
 460                        fprintf(stderr, "%s ",
 461                                inet_ntoa(*(struct in_addr *)&sa.sin_addr));
 462                break;
 463        }
 464
 465        if (sockfd < 0)
 466                die("unable to connect to %s:\n%s", host, error_message.buf);
 467
 468        enable_keepalive(sockfd);
 469
 470        if (flags & CONNECT_VERBOSE)
 471                fprintf(stderr, "done.\n");
 472
 473        return sockfd;
 474}
 475
 476#endif /* NO_IPV6 */
 477
 478
 479static void git_tcp_connect(int fd[2], char *host, int flags)
 480{
 481        int sockfd = git_tcp_connect_sock(host, flags);
 482
 483        fd[0] = sockfd;
 484        fd[1] = dup(sockfd);
 485}
 486
 487
 488static char *git_proxy_command;
 489
 490static int git_proxy_command_options(const char *var, const char *value,
 491                void *cb)
 492{
 493        if (!strcmp(var, "core.gitproxy")) {
 494                const char *for_pos;
 495                int matchlen = -1;
 496                int hostlen;
 497                const char *rhost_name = cb;
 498                int rhost_len = strlen(rhost_name);
 499
 500                if (git_proxy_command)
 501                        return 0;
 502                if (!value)
 503                        return config_error_nonbool(var);
 504                /* [core]
 505                 * ;# matches www.kernel.org as well
 506                 * gitproxy = netcatter-1 for kernel.org
 507                 * gitproxy = netcatter-2 for sample.xz
 508                 * gitproxy = netcatter-default
 509                 */
 510                for_pos = strstr(value, " for ");
 511                if (!for_pos)
 512                        /* matches everybody */
 513                        matchlen = strlen(value);
 514                else {
 515                        hostlen = strlen(for_pos + 5);
 516                        if (rhost_len < hostlen)
 517                                matchlen = -1;
 518                        else if (!strncmp(for_pos + 5,
 519                                          rhost_name + rhost_len - hostlen,
 520                                          hostlen) &&
 521                                 ((rhost_len == hostlen) ||
 522                                  rhost_name[rhost_len - hostlen -1] == '.'))
 523                                matchlen = for_pos - value;
 524                        else
 525                                matchlen = -1;
 526                }
 527                if (0 <= matchlen) {
 528                        /* core.gitproxy = none for kernel.org */
 529                        if (matchlen == 4 &&
 530                            !memcmp(value, "none", 4))
 531                                matchlen = 0;
 532                        git_proxy_command = xmemdupz(value, matchlen);
 533                }
 534                return 0;
 535        }
 536
 537        return git_default_config(var, value, cb);
 538}
 539
 540static int git_use_proxy(const char *host)
 541{
 542        git_proxy_command = getenv("GIT_PROXY_COMMAND");
 543        git_config(git_proxy_command_options, (void*)host);
 544        return (git_proxy_command && *git_proxy_command);
 545}
 546
 547static struct child_process *git_proxy_connect(int fd[2], char *host)
 548{
 549        const char *port = STR(DEFAULT_GIT_PORT);
 550        struct child_process *proxy;
 551
 552        get_host_and_port(&host, &port);
 553
 554        proxy = xmalloc(sizeof(*proxy));
 555        child_process_init(proxy);
 556        argv_array_push(&proxy->args, git_proxy_command);
 557        argv_array_push(&proxy->args, host);
 558        argv_array_push(&proxy->args, port);
 559        proxy->in = -1;
 560        proxy->out = -1;
 561        if (start_command(proxy))
 562                die("cannot start proxy %s", git_proxy_command);
 563        fd[0] = proxy->out; /* read from proxy stdout */
 564        fd[1] = proxy->in;  /* write to proxy stdin */
 565        return proxy;
 566}
 567
 568static char *get_port(char *host)
 569{
 570        char *end;
 571        char *p = strchr(host, ':');
 572
 573        if (p) {
 574                long port = strtol(p + 1, &end, 10);
 575                if (end != p + 1 && *end == '\0' && 0 <= port && port < 65536) {
 576                        *p = '\0';
 577                        return p+1;
 578                }
 579        }
 580
 581        return NULL;
 582}
 583
 584/*
 585 * Extract protocol and relevant parts from the specified connection URL.
 586 * The caller must free() the returned strings.
 587 */
 588static enum protocol parse_connect_url(const char *url_orig, char **ret_host,
 589                                       char **ret_path)
 590{
 591        char *url;
 592        char *host, *path;
 593        char *end;
 594        int separator = '/';
 595        enum protocol protocol = PROTO_LOCAL;
 596
 597        if (is_url(url_orig))
 598                url = url_decode(url_orig);
 599        else
 600                url = xstrdup(url_orig);
 601
 602        host = strstr(url, "://");
 603        if (host) {
 604                *host = '\0';
 605                protocol = get_protocol(url);
 606                host += 3;
 607        } else {
 608                host = url;
 609                if (!url_is_local_not_ssh(url)) {
 610                        protocol = PROTO_SSH;
 611                        separator = ':';
 612                }
 613        }
 614
 615        /*
 616         * Don't do destructive transforms as protocol code does
 617         * '[]' unwrapping in get_host_and_port()
 618         */
 619        end = host_end(&host, 0);
 620
 621        if (protocol == PROTO_LOCAL)
 622                path = end;
 623        else if (protocol == PROTO_FILE && has_dos_drive_prefix(end))
 624                path = end; /* "file://$(pwd)" may be "file://C:/projects/repo" */
 625        else
 626                path = strchr(end, separator);
 627
 628        if (!path || !*path)
 629                die("No path specified. See 'man git-pull' for valid url syntax");
 630
 631        /*
 632         * null-terminate hostname and point path to ~ for URL's like this:
 633         *    ssh://host.xz/~user/repo
 634         */
 635
 636        end = path; /* Need to \0 terminate host here */
 637        if (separator == ':')
 638                path++; /* path starts after ':' */
 639        if (protocol == PROTO_GIT || protocol == PROTO_SSH) {
 640                if (path[1] == '~')
 641                        path++;
 642        }
 643
 644        path = xstrdup(path);
 645        *end = '\0';
 646
 647        *ret_host = xstrdup(host);
 648        *ret_path = path;
 649        free(url);
 650        return protocol;
 651}
 652
 653static struct child_process no_fork = CHILD_PROCESS_INIT;
 654
 655/*
 656 * This returns a dummy child_process if the transport protocol does not
 657 * need fork(2), or a struct child_process object if it does.  Once done,
 658 * finish the connection with finish_connect() with the value returned from
 659 * this function (it is safe to call finish_connect() with NULL to support
 660 * the former case).
 661 *
 662 * If it returns, the connect is successful; it just dies on errors (this
 663 * will hopefully be changed in a libification effort, to return NULL when
 664 * the connection failed).
 665 */
 666struct child_process *git_connect(int fd[2], const char *url,
 667                                  const char *prog, int flags)
 668{
 669        char *hostandport, *path;
 670        struct child_process *conn = &no_fork;
 671        enum protocol protocol;
 672        struct strbuf cmd = STRBUF_INIT;
 673
 674        /* Without this we cannot rely on waitpid() to tell
 675         * what happened to our children.
 676         */
 677        signal(SIGCHLD, SIG_DFL);
 678
 679        protocol = parse_connect_url(url, &hostandport, &path);
 680        if ((flags & CONNECT_DIAG_URL) && (protocol != PROTO_SSH)) {
 681                printf("Diag: url=%s\n", url ? url : "NULL");
 682                printf("Diag: protocol=%s\n", prot_name(protocol));
 683                printf("Diag: hostandport=%s\n", hostandport ? hostandport : "NULL");
 684                printf("Diag: path=%s\n", path ? path : "NULL");
 685                conn = NULL;
 686        } else if (protocol == PROTO_GIT) {
 687                /*
 688                 * Set up virtual host information based on where we will
 689                 * connect, unless the user has overridden us in
 690                 * the environment.
 691                 */
 692                char *target_host = getenv("GIT_OVERRIDE_VIRTUAL_HOST");
 693                if (target_host)
 694                        target_host = xstrdup(target_host);
 695                else
 696                        target_host = xstrdup(hostandport);
 697
 698                transport_check_allowed("git");
 699
 700                /* These underlying connection commands die() if they
 701                 * cannot connect.
 702                 */
 703                if (git_use_proxy(hostandport))
 704                        conn = git_proxy_connect(fd, hostandport);
 705                else
 706                        git_tcp_connect(fd, hostandport, flags);
 707                /*
 708                 * Separate original protocol components prog and path
 709                 * from extended host header with a NUL byte.
 710                 *
 711                 * Note: Do not add any other headers here!  Doing so
 712                 * will cause older git-daemon servers to crash.
 713                 */
 714                packet_write(fd[1],
 715                             "%s %s%chost=%s%c",
 716                             prog, path, 0,
 717                             target_host, 0);
 718                free(target_host);
 719        } else {
 720                conn = xmalloc(sizeof(*conn));
 721                child_process_init(conn);
 722
 723                strbuf_addstr(&cmd, prog);
 724                strbuf_addch(&cmd, ' ');
 725                sq_quote_buf(&cmd, path);
 726
 727                conn->in = conn->out = -1;
 728                if (protocol == PROTO_SSH) {
 729                        const char *ssh;
 730                        int putty, tortoiseplink = 0;
 731                        char *ssh_host = hostandport;
 732                        const char *port = NULL;
 733                        transport_check_allowed("ssh");
 734                        get_host_and_port(&ssh_host, &port);
 735
 736                        if (!port)
 737                                port = get_port(ssh_host);
 738
 739                        if (flags & CONNECT_DIAG_URL) {
 740                                printf("Diag: url=%s\n", url ? url : "NULL");
 741                                printf("Diag: protocol=%s\n", prot_name(protocol));
 742                                printf("Diag: userandhost=%s\n", ssh_host ? ssh_host : "NULL");
 743                                printf("Diag: port=%s\n", port ? port : "NONE");
 744                                printf("Diag: path=%s\n", path ? path : "NULL");
 745
 746                                free(hostandport);
 747                                free(path);
 748                                free(conn);
 749                                return NULL;
 750                        }
 751
 752                        ssh = getenv("GIT_SSH_COMMAND");
 753                        if (ssh) {
 754                                conn->use_shell = 1;
 755                                putty = 0;
 756                        } else {
 757                                const char *base;
 758                                char *ssh_dup;
 759
 760                                ssh = getenv("GIT_SSH");
 761                                if (!ssh)
 762                                        ssh = "ssh";
 763
 764                                ssh_dup = xstrdup(ssh);
 765                                base = basename(ssh_dup);
 766
 767                                tortoiseplink = !strcasecmp(base, "tortoiseplink") ||
 768                                        !strcasecmp(base, "tortoiseplink.exe");
 769                                putty = !strcasecmp(base, "plink") ||
 770                                        !strcasecmp(base, "plink.exe") || tortoiseplink;
 771
 772                                free(ssh_dup);
 773                        }
 774
 775                        argv_array_push(&conn->args, ssh);
 776                        if (tortoiseplink)
 777                                argv_array_push(&conn->args, "-batch");
 778                        if (port) {
 779                                /* P is for PuTTY, p is for OpenSSH */
 780                                argv_array_push(&conn->args, putty ? "-P" : "-p");
 781                                argv_array_push(&conn->args, port);
 782                        }
 783                        argv_array_push(&conn->args, ssh_host);
 784                } else {
 785                        /* remove repo-local variables from the environment */
 786                        conn->env = local_repo_env;
 787                        conn->use_shell = 1;
 788                        transport_check_allowed("file");
 789                }
 790                argv_array_push(&conn->args, cmd.buf);
 791
 792                if (start_command(conn))
 793                        die("unable to fork");
 794
 795                fd[0] = conn->out; /* read from child's stdout */
 796                fd[1] = conn->in;  /* write to child's stdin */
 797                strbuf_release(&cmd);
 798        }
 799        free(hostandport);
 800        free(path);
 801        return conn;
 802}
 803
 804int git_connection_is_socket(struct child_process *conn)
 805{
 806        return conn == &no_fork;
 807}
 808
 809int finish_connect(struct child_process *conn)
 810{
 811        int code;
 812        if (!conn || git_connection_is_socket(conn))
 813                return 0;
 814
 815        code = finish_command(conn);
 816        free(conn);
 817        return code;
 818}