connect.c

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