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, unsigned int flags)
  17 {
  18         if (!flags)
  19                 return 1;
  20
  21         if (!skip_prefix(name, "refs/", &name))
  22                 return 0;
  23
  24         /* REF_NORMAL means that we don't want the magic fake tag refs */
  25         if ((flags & REF_NORMAL) && check_refname_format(name, 0))
  26                 return 0;
  27
  28         /* REF_HEADS means that we want regular branch heads */
  29         if ((flags & REF_HEADS) && starts_with(name, "heads/"))
  30                 return 1;
  31
  32         /* REF_TAGS means that we want tags */
  33         if ((flags & REF_TAGS) && starts_with(name, "tags/"))
  34                 return 1;
  35
  36         /* All type bits clear means that we are ok with anything */
  37         return !(flags & ~REF_NORMAL);
  38 }
  39
  40 int check_ref_type(const struct ref *ref, int flags)
  41 {
  42         return check_ref(ref->name, flags);
  43 }
  44
  45 static void die_initial_contact(int got_at_least_one_head)
  46 {
  47         if (got_at_least_one_head)
  48                 die("The remote end hung up upon initial contact");
  49         else
  50                 die("Could not read from remote repository.\n\n"
  51                     "Please make sure you have the correct access rights\n"
  52                     "and the repository exists.");
  53 }
  54
  55 static void parse_one_symref_info(struct string_list *symref, const char *val, int len)
  56 {
  57         char *sym, *target;
  58         struct string_list_item *item;
  59
  60         if (!len)
  61                 return; /* just "symref" */
  62         /* e.g. "symref=HEAD:refs/heads/master" */
  63         sym = xmemdupz(val, len);
  64         target = strchr(sym, ':');
  65         if (!target)
  66                 /* just "symref=something" */
  67                 goto reject;
  68         *(target++) = '\0';
  69         if (check_refname_format(sym, REFNAME_ALLOW_ONELEVEL) ||
  70             check_refname_format(target, REFNAME_ALLOW_ONELEVEL))
  71                 /* "symref=bogus:pair */
  72                 goto reject;
  73         item = string_list_append(symref, sym);
  74         item->util = target;
  75         return;
  76 reject:
  77         free(sym);
  78         return;
  79 }
  80
  81 static void annotate_refs_with_symref_info(struct ref *ref)
  82 {
  83         struct string_list symref = STRING_LIST_INIT_DUP;
  84         const char *feature_list = server_capabilities;
  85
  86         while (feature_list) {
  87                 int len;
  88                 const char *val;
  89
  90                 val = parse_feature_value(feature_list, "symref", &len);
  91                 if (!val)
  92                         break;
  93                 parse_one_symref_info(&symref, val, len);
  94                 feature_list = val + 1;
  95         }
  96         sort_string_list(&symref);
  97
  98         for (; ref; ref = ref->next) {
  99                 struct string_list_item *item;
 100                 item = string_list_lookup(&symref, ref->name);
 101                 if (!item)
 102                         continue;
 103                 ref->symref = xstrdup((char *)item->util);
 104         }
 105         string_list_clear(&symref, 0);
 106 }
 107
 108 /*
 109  * Read all the refs from the other end
 110  */
 111 struct ref **get_remote_heads(int in, char *src_buf, size_t src_len,
 112                               struct ref **list, unsigned int flags,
 113                               struct sha1_array *extra_have,
 114                               struct sha1_array *shallow_points)
 115 {
 116         struct ref **orig_list = list;
 117         int got_at_least_one_head = 0;
 118
 119         *list = NULL;
 120         for (;;) {
 121                 struct ref *ref;
 122                 unsigned char old_sha1[20];
 123                 char *name;
 124                 int len, name_len;
 125                 char *buffer = packet_buffer;
 126                 const char *arg;
 127
 128                 len = packet_read(in, &src_buf, &src_len,
 129                                   packet_buffer, sizeof(packet_buffer),
 130                                   PACKET_READ_GENTLE_ON_EOF |
 131                                   PACKET_READ_CHOMP_NEWLINE);
 132                 if (len < 0)
 133                         die_initial_contact(got_at_least_one_head);
 134
 135                 if (!len)
 136                         break;
 137
 138                 if (len > 4 && skip_prefix(buffer, "ERR ", &arg))
 139                         die("remote error: %s", arg);
 140
 141                 if (len == 48 && skip_prefix(buffer, "shallow ", &arg)) {
 142                         if (get_sha1_hex(arg, old_sha1))
 143                                 die("protocol error: expected shallow sha-1, got '%s'", arg);
 144                         if (!shallow_points)
 145                                 die("repository on the other end cannot be shallow");
 146                         sha1_array_append(shallow_points, old_sha1);
 147                         continue;
 148                 }
 149
 150                 if (len < 42 || get_sha1_hex(buffer, old_sha1) || buffer[40] != ' ')
 151                         die("protocol error: expected sha/ref, got '%s'", buffer);
 152                 name = buffer + 41;
 153
 154                 name_len = strlen(name);
 155                 if (len != name_len + 41) {
 156                         free(server_capabilities);
 157                         server_capabilities = xstrdup(name + name_len + 1);
 158                 }
 159
 160                 if (extra_have &&
 161                     name_len == 5 && !memcmp(".have", name, 5)) {
 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
 180 static 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
 217 int parse_feature_request(const char *feature_list, const char *feature)
 218 {
 219         return !!parse_feature_value(feature_list, feature, NULL);
 220 }
 221
 222 const char *server_feature_value(const char *feature, int *len)
 223 {
 224         return parse_feature_value(server_capabilities, feature, len);
 225 }
 226
 227 int server_supports(const char *feature)
 228 {
 229         return !!server_feature_value(feature, NULL);
 230 }
 231
 232 enum protocol {
 233         PROTO_LOCAL = 1,
 234         PROTO_FILE,
 235         PROTO_SSH,
 236         PROTO_GIT
 237 };
 238
 239 int 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
 247 static 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
 262 static 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
 277 static 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
 304 static 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                 }
 315         }
 316 }
 317
 318 static void enable_keepalive(int sockfd)
 319 {
 320         int ka = 1;
 321
 322         if (setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, &ka, sizeof(ka)) < 0)
 323                 fprintf(stderr, "unable to set SO_KEEPALIVE on socket: %s\n",
 324                         strerror(errno));
 325 }
 326
 327 #ifndef NO_IPV6
 328
 329 static const char *ai_name(const struct addrinfo *ai)
 330 {
 331         static char addr[NI_MAXHOST];
 332         if (getnameinfo(ai->ai_addr, ai->ai_addrlen, addr, sizeof(addr), NULL, 0,
 333                         NI_NUMERICHOST) != 0)
 334                 strcpy(addr, "(unknown)");
 335
 336         return addr;
 337 }
 338
 339 /*
 340  * Returns a connected socket() fd, or else die()s.
 341  */
 342 static int git_tcp_connect_sock(char *host, int flags)
 343 {
 344         struct strbuf error_message = STRBUF_INIT;
 345         int sockfd = -1;
 346         const char *port = STR(DEFAULT_GIT_PORT);
 347         struct addrinfo hints, *ai0, *ai;
 348         int gai;
 349         int cnt = 0;
 350
 351         get_host_and_port(&host, &port);
 352         if (!*port)
 353                 port = "<none>";
 354
 355         memset(&hints, 0, sizeof(hints));
 356         hints.ai_socktype = SOCK_STREAM;
 357         hints.ai_protocol = IPPROTO_TCP;
 358
 359         if (flags & CONNECT_VERBOSE)
 360                 fprintf(stderr, "Looking up %s ... ", host);
 361
 362         gai = getaddrinfo(host, port, &hints, &ai);
 363         if (gai)
 364                 die("Unable to look up %s (port %s) (%s)", host, port, gai_strerror(gai));
 365
 366         if (flags & CONNECT_VERBOSE)
 367                 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 368
 369         for (ai0 = ai; ai; ai = ai->ai_next, cnt++) {
 370                 sockfd = socket(ai->ai_family,
 371                                 ai->ai_socktype, ai->ai_protocol);
 372                 if ((sockfd < 0) ||
 373                     (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0)) {
 374                         strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 375                                     host, cnt, ai_name(ai), strerror(errno));
 376                         if (0 <= sockfd)
 377                                 close(sockfd);
 378                         sockfd = -1;
 379                         continue;
 380                 }
 381                 if (flags & CONNECT_VERBOSE)
 382                         fprintf(stderr, "%s ", ai_name(ai));
 383                 break;
 384         }
 385
 386         freeaddrinfo(ai0);
 387
 388         if (sockfd < 0)
 389                 die("unable to connect to %s:\n%s", host, error_message.buf);
 390
 391         enable_keepalive(sockfd);
 392
 393         if (flags & CONNECT_VERBOSE)
 394                 fprintf(stderr, "done.\n");
 395
 396         strbuf_release(&error_message);
 397
 398         return sockfd;
 399 }
 400
 401 #else /* NO_IPV6 */
 402
 403 /*
 404  * Returns a connected socket() fd, or else die()s.
 405  */
 406 static int git_tcp_connect_sock(char *host, int flags)
 407 {
 408         struct strbuf error_message = STRBUF_INIT;
 409         int sockfd = -1;
 410         const char *port = STR(DEFAULT_GIT_PORT);
 411         char *ep;
 412         struct hostent *he;
 413         struct sockaddr_in sa;
 414         char **ap;
 415         unsigned int nport;
 416         int cnt;
 417
 418         get_host_and_port(&host, &port);
 419
 420         if (flags & CONNECT_VERBOSE)
 421                 fprintf(stderr, "Looking up %s ... ", host);
 422
 423         he = gethostbyname(host);
 424         if (!he)
 425                 die("Unable to look up %s (%s)", host, hstrerror(h_errno));
 426         nport = strtoul(port, &ep, 10);
 427         if ( ep == port || *ep ) {
 428                 /* Not numeric */
 429                 struct servent *se = getservbyname(port,"tcp");
 430                 if ( !se )
 431                         die("Unknown port %s", port);
 432                 nport = se->s_port;
 433         }
 434
 435         if (flags & CONNECT_VERBOSE)
 436                 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 437
 438         for (cnt = 0, ap = he->h_addr_list; *ap; ap++, cnt++) {
 439                 memset(&sa, 0, sizeof sa);
 440                 sa.sin_family = he->h_addrtype;
 441                 sa.sin_port = htons(nport);
 442                 memcpy(&sa.sin_addr, *ap, he->h_length);
 443
 444                 sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 445                 if ((sockfd < 0) ||
 446                     connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 447                         strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 448                                 host,
 449                                 cnt,
 450                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr),
 451                                 strerror(errno));
 452                         if (0 <= sockfd)
 453                                 close(sockfd);
 454                         sockfd = -1;
 455                         continue;
 456                 }
 457                 if (flags & CONNECT_VERBOSE)
 458                         fprintf(stderr, "%s ",
 459                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr));
 460                 break;
 461         }
 462
 463         if (sockfd < 0)
 464                 die("unable to connect to %s:\n%s", host, error_message.buf);
 465
 466         enable_keepalive(sockfd);
 467
 468         if (flags & CONNECT_VERBOSE)
 469                 fprintf(stderr, "done.\n");
 470
 471         return sockfd;
 472 }
 473
 474 #endif /* NO_IPV6 */
 475
 476
 477 static void git_tcp_connect(int fd[2], char *host, int flags)
 478 {
 479         int sockfd = git_tcp_connect_sock(host, flags);
 480
 481         fd[0] = sockfd;
 482         fd[1] = dup(sockfd);
 483 }
 484
 485
 486 static char *git_proxy_command;
 487
 488 static int git_proxy_command_options(const char *var, const char *value,
 489                 void *cb)
 490 {
 491         if (!strcmp(var, "core.gitproxy")) {
 492                 const char *for_pos;
 493                 int matchlen = -1;
 494                 int hostlen;
 495                 const char *rhost_name = cb;
 496                 int rhost_len = strlen(rhost_name);
 497
 498                 if (git_proxy_command)
 499                         return 0;
 500                 if (!value)
 501                         return config_error_nonbool(var);
 502                 /* [core]
 503                  * ;# matches www.kernel.org as well
 504                  * gitproxy = netcatter-1 for kernel.org
 505                  * gitproxy = netcatter-2 for sample.xz
 506                  * gitproxy = netcatter-default
 507                  */
 508                 for_pos = strstr(value, " for ");
 509                 if (!for_pos)
 510                         /* matches everybody */
 511                         matchlen = strlen(value);
 512                 else {
 513                         hostlen = strlen(for_pos + 5);
 514                         if (rhost_len < hostlen)
 515                                 matchlen = -1;
 516                         else if (!strncmp(for_pos + 5,
 517                                           rhost_name + rhost_len - hostlen,
 518                                           hostlen) &&
 519                                  ((rhost_len == hostlen) ||
 520                                   rhost_name[rhost_len - hostlen -1] == '.'))
 521                                 matchlen = for_pos - value;
 522                         else
 523                                 matchlen = -1;
 524                 }
 525                 if (0 <= matchlen) {
 526                         /* core.gitproxy = none for kernel.org */
 527                         if (matchlen == 4 &&
 528                             !memcmp(value, "none", 4))
 529                                 matchlen = 0;
 530                         git_proxy_command = xmemdupz(value, matchlen);
 531                 }
 532                 return 0;
 533         }
 534
 535         return git_default_config(var, value, cb);
 536 }
 537
 538 static int git_use_proxy(const char *host)
 539 {
 540         git_proxy_command = getenv("GIT_PROXY_COMMAND");
 541         git_config(git_proxy_command_options, (void*)host);
 542         return (git_proxy_command && *git_proxy_command);
 543 }
 544
 545 static struct child_process *git_proxy_connect(int fd[2], char *host)
 546 {
 547         const char *port = STR(DEFAULT_GIT_PORT);
 548         struct child_process *proxy;
 549
 550         get_host_and_port(&host, &port);
 551
 552         proxy = xmalloc(sizeof(*proxy));
 553         child_process_init(proxy);
 554         argv_array_push(&proxy->args, git_proxy_command);
 555         argv_array_push(&proxy->args, host);
 556         argv_array_push(&proxy->args, port);
 557         proxy->in = -1;
 558         proxy->out = -1;
 559         if (start_command(proxy))
 560                 die("cannot start proxy %s", git_proxy_command);
 561         fd[0] = proxy->out; /* read from proxy stdout */
 562         fd[1] = proxy->in;  /* write to proxy stdin */
 563         return proxy;
 564 }
 565
 566 static char *get_port(char *host)
 567 {
 568         char *end;
 569         char *p = strchr(host, ':');
 570
 571         if (p) {
 572                 long port = strtol(p + 1, &end, 10);
 573                 if (end != p + 1 && *end == '\0' && 0 <= port && port < 65536) {
 574                         *p = '\0';
 575                         return p+1;
 576                 }
 577         }
 578
 579         return NULL;
 580 }
 581
 582 /*
 583  * Extract protocol and relevant parts from the specified connection URL.
 584  * The caller must free() the returned strings.
 585  */
 586 static enum protocol parse_connect_url(const char *url_orig, char **ret_host,
 587                                        char **ret_path)
 588 {
 589         char *url;
 590         char *host, *path;
 591         char *end;
 592         int separator = '/';
 593         enum protocol protocol = PROTO_LOCAL;
 594
 595         if (is_url(url_orig))
 596                 url = url_decode(url_orig);
 597         else
 598                 url = xstrdup(url_orig);
 599
 600         host = strstr(url, "://");
 601         if (host) {
 602                 *host = '\0';
 603                 protocol = get_protocol(url);
 604                 host += 3;
 605         } else {
 606                 host = url;
 607                 if (!url_is_local_not_ssh(url)) {
 608                         protocol = PROTO_SSH;
 609                         separator = ':';
 610                 }
 611         }
 612
 613         /*
 614          * Don't do destructive transforms as protocol code does
 615          * '[]' unwrapping in get_host_and_port()
 616          */
 617         end = host_end(&host, 0);
 618
 619         if (protocol == PROTO_LOCAL)
 620                 path = end;
 621         else if (protocol == PROTO_FILE && has_dos_drive_prefix(end))
 622                 path = end; /* "file://$(pwd)" may be "file://C:/projects/repo" */
 623         else
 624                 path = strchr(end, separator);
 625
 626         if (!path || !*path)
 627                 die("No path specified. See 'man git-pull' for valid url syntax");
 628
 629         /*
 630          * null-terminate hostname and point path to ~ for URL's like this:
 631          *    ssh://host.xz/~user/repo
 632          */
 633
 634         end = path; /* Need to \0 terminate host here */
 635         if (separator == ':')
 636                 path++; /* path starts after ':' */
 637         if (protocol == PROTO_GIT || protocol == PROTO_SSH) {
 638                 if (path[1] == '~')
 639                         path++;
 640         }
 641
 642         path = xstrdup(path);
 643         *end = '\0';
 644
 645         *ret_host = xstrdup(host);
 646         *ret_path = path;
 647         free(url);
 648         return protocol;
 649 }
 650
 651 static struct child_process no_fork = CHILD_PROCESS_INIT;
 652
 653 /*
 654  * This returns a dummy child_process if the transport protocol does not
 655  * need fork(2), or a struct child_process object if it does.  Once done,
 656  * finish the connection with finish_connect() with the value returned from
 657  * this function (it is safe to call finish_connect() with NULL to support
 658  * the former case).
 659  *
 660  * If it returns, the connect is successful; it just dies on errors (this
 661  * will hopefully be changed in a libification effort, to return NULL when
 662  * the connection failed).
 663  */
 664 struct child_process *git_connect(int fd[2], const char *url,
 665                                   const char *prog, int flags)
 666 {
 667         char *hostandport, *path;
 668         struct child_process *conn = &no_fork;
 669         enum protocol protocol;
 670         struct strbuf cmd = STRBUF_INIT;
 671
 672         /* Without this we cannot rely on waitpid() to tell
 673          * what happened to our children.
 674          */
 675         signal(SIGCHLD, SIG_DFL);
 676
 677         protocol = parse_connect_url(url, &hostandport, &path);
 678         if (flags & CONNECT_DIAG_URL) {
 679                 printf("Diag: url=%s\n", url ? url : "NULL");
 680                 printf("Diag: protocol=%s\n", prot_name(protocol));
 681                 printf("Diag: hostandport=%s\n", hostandport ? hostandport : "NULL");
 682                 printf("Diag: path=%s\n", path ? path : "NULL");
 683                 conn = NULL;
 684         } else if (protocol == PROTO_GIT) {
 685                 /* These underlying connection commands die() if they
 686                  * cannot connect.
 687                  */
 688                 char *target_host = xstrdup(hostandport);
 689                 if (git_use_proxy(hostandport))
 690                         conn = git_proxy_connect(fd, hostandport);
 691                 else
 692                         git_tcp_connect(fd, hostandport, flags);
 693                 /*
 694                  * Separate original protocol components prog and path
 695                  * from extended host header with a NUL byte.
 696                  *
 697                  * Note: Do not add any other headers here!  Doing so
 698                  * will cause older git-daemon servers to crash.
 699                  */
 700                 packet_write(fd[1],
 701                              "%s %s%chost=%s%c",
 702                              prog, path, 0,
 703                              target_host, 0);
 704                 free(target_host);
 705         } else {
 706                 conn = xmalloc(sizeof(*conn));
 707                 child_process_init(conn);
 708
 709                 strbuf_addstr(&cmd, prog);
 710                 strbuf_addch(&cmd, ' ');
 711                 sq_quote_buf(&cmd, path);
 712
 713                 conn->in = conn->out = -1;
 714                 if (protocol == PROTO_SSH) {
 715                         const char *ssh = getenv("GIT_SSH");
 716                         int putty = ssh && strcasestr(ssh, "plink");
 717                         char *ssh_host = hostandport;
 718                         const char *port = NULL;
 719                         get_host_and_port(&ssh_host, &port);
 720                         if (!port)
 721                                 port = get_port(ssh_host);
 722
 723                         if (!ssh) ssh = "ssh";
 724
 725                         argv_array_push(&conn->args, ssh);
 726                         if (putty && !strcasestr(ssh, "tortoiseplink"))
 727                                 argv_array_push(&conn->args, "-batch");
 728                         if (port) {
 729                                 /* P is for PuTTY, p is for OpenSSH */
 730                                 argv_array_push(&conn->args, putty ? "-P" : "-p");
 731                                 argv_array_push(&conn->args, port);
 732                         }
 733                         argv_array_push(&conn->args, ssh_host);
 734                 } else {
 735                         /* remove repo-local variables from the environment */
 736                         conn->env = local_repo_env;
 737                         conn->use_shell = 1;
 738                 }
 739                 argv_array_push(&conn->args, cmd.buf);
 740
 741                 if (start_command(conn))
 742                         die("unable to fork");
 743
 744                 fd[0] = conn->out; /* read from child's stdout */
 745                 fd[1] = conn->in;  /* write to child's stdin */
 746                 strbuf_release(&cmd);
 747         }
 748         free(hostandport);
 749         free(path);
 750         return conn;
 751 }
 752
 753 int git_connection_is_socket(struct child_process *conn)
 754 {
 755         return conn == &no_fork;
 756 }
 757
 758 int finish_connect(struct child_process *conn)
 759 {
 760         int code;
 761         if (!conn || git_connection_is_socket(conn))
 762                 return 0;
 763
 764         code = finish_command(conn);
 765         free(conn);
 766         return code;
 767 }