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
  12 static char *server_capabilities;
  13 static const char *parse_feature_value(const char *, const char *, int *);
  14
  15 static int check_ref(const char *name, int len, unsigned int flags)
  16 {
  17         if (!flags)
  18                 return 1;
  19
  20         if (len < 5 || memcmp(name, "refs/", 5))
  21                 return 0;
  22
  23         /* Skip the "refs/" part */
  24         name += 5;
  25         len -= 5;
  26
  27         /* REF_NORMAL means that we don't want the magic fake tag refs */
  28         if ((flags & REF_NORMAL) && check_refname_format(name, 0))
  29                 return 0;
  30
  31         /* REF_HEADS means that we want regular branch heads */
  32         if ((flags & REF_HEADS) && !memcmp(name, "heads/", 6))
  33                 return 1;
  34
  35         /* REF_TAGS means that we want tags */
  36         if ((flags & REF_TAGS) && !memcmp(name, "tags/", 5))
  37                 return 1;
  38
  39         /* All type bits clear means that we are ok with anything */
  40         return !(flags & ~REF_NORMAL);
  41 }
  42
  43 int check_ref_type(const struct ref *ref, int flags)
  44 {
  45         return check_ref(ref->name, strlen(ref->name), flags);
  46 }
  47
  48 static void add_extra_have(struct extra_have_objects *extra, unsigned char *sha1)
  49 {
  50         ALLOC_GROW(extra->array, extra->nr + 1, extra->alloc);
  51         hashcpy(&(extra->array[extra->nr][0]), sha1);
  52         extra->nr++;
  53 }
  54
  55 static void die_initial_contact(int got_at_least_one_head)
  56 {
  57         if (got_at_least_one_head)
  58                 die("The remote end hung up upon initial contact");
  59         else
  60                 die("Could not read from remote repository.\n\n"
  61                     "Please make sure you have the correct access rights\n"
  62                     "and the repository exists.");
  63 }
  64
  65 static void parse_one_symref_info(struct string_list *symref, const char *val, int len)
  66 {
  67         char *sym, *target;
  68         struct string_list_item *item;
  69
  70         if (!len)
  71                 return; /* just "symref" */
  72         /* e.g. "symref=HEAD:refs/heads/master" */
  73         sym = xmalloc(len + 1);
  74         memcpy(sym, val, len);
  75         sym[len] = '\0';
  76         target = strchr(sym, ':');
  77         if (!target)
  78                 /* just "symref=something" */
  79                 goto reject;
  80         *(target++) = '\0';
  81         if (check_refname_format(sym, REFNAME_ALLOW_ONELEVEL) ||
  82             check_refname_format(target, REFNAME_ALLOW_ONELEVEL))
  83                 /* "symref=bogus:pair */
  84                 goto reject;
  85         item = string_list_append(symref, sym);
  86         item->util = target;
  87         return;
  88 reject:
  89         free(sym);
  90         return;
  91 }
  92
  93 static void annotate_refs_with_symref_info(struct ref *ref)
  94 {
  95         struct string_list symref = STRING_LIST_INIT_DUP;
  96         const char *feature_list = server_capabilities;
  97
  98         while (feature_list) {
  99                 int len;
 100                 const char *val;
 101
 102                 val = parse_feature_value(feature_list, "symref", &len);
 103                 if (!val)
 104                         break;
 105                 parse_one_symref_info(&symref, val, len);
 106                 feature_list = val + 1;
 107         }
 108         sort_string_list(&symref);
 109
 110         for (; ref; ref = ref->next) {
 111                 struct string_list_item *item;
 112                 item = string_list_lookup(&symref, ref->name);
 113                 if (!item)
 114                         continue;
 115                 ref->symref = xstrdup((char *)item->util);
 116         }
 117         string_list_clear(&symref, 0);
 118 }
 119
 120 /*
 121  * Read all the refs from the other end
 122  */
 123 struct ref **get_remote_heads(int in, char *src_buf, size_t src_len,
 124                               struct ref **list, unsigned int flags,
 125                               struct extra_have_objects *extra_have)
 126 {
 127         struct ref **orig_list = list;
 128         int got_at_least_one_head = 0;
 129
 130         *list = NULL;
 131         for (;;) {
 132                 struct ref *ref;
 133                 unsigned char old_sha1[20];
 134                 char *name;
 135                 int len, name_len;
 136                 char *buffer = packet_buffer;
 137
 138                 len = packet_read(in, &src_buf, &src_len,
 139                                   packet_buffer, sizeof(packet_buffer),
 140                                   PACKET_READ_GENTLE_ON_EOF |
 141                                   PACKET_READ_CHOMP_NEWLINE);
 142                 if (len < 0)
 143                         die_initial_contact(got_at_least_one_head);
 144
 145                 if (!len)
 146                         break;
 147
 148                 if (len > 4 && !prefixcmp(buffer, "ERR "))
 149                         die("remote error: %s", buffer + 4);
 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 &&
 162                     name_len == 5 && !memcmp(".have", name, 5)) {
 163                         add_extra_have(extra_have, old_sha1);
 164                         continue;
 165                 }
 166
 167                 if (!check_ref(name, name_len, flags))
 168                         continue;
 169                 ref = alloc_ref(buffer + 41);
 170                 hashcpy(ref->old_sha1, old_sha1);
 171                 *list = ref;
 172                 list = &ref->next;
 173                 got_at_least_one_head = 1;
 174         }
 175
 176         annotate_refs_with_symref_info(*orig_list);
 177
 178         return list;
 179 }
 180
 181 static const char *parse_feature_value(const char *feature_list, const char *feature, int *lenp)
 182 {
 183         int len;
 184
 185         if (!feature_list)
 186                 return NULL;
 187
 188         len = strlen(feature);
 189         while (*feature_list) {
 190                 const char *found = strstr(feature_list, feature);
 191                 if (!found)
 192                         return NULL;
 193                 if (feature_list == found || isspace(found[-1])) {
 194                         const char *value = found + len;
 195                         /* feature with no value (e.g., "thin-pack") */
 196                         if (!*value || isspace(*value)) {
 197                                 if (lenp)
 198                                         *lenp = 0;
 199                                 return value;
 200                         }
 201                         /* feature with a value (e.g., "agent=git/1.2.3") */
 202                         else if (*value == '=') {
 203                                 value++;
 204                                 if (lenp)
 205                                         *lenp = strcspn(value, " \t\n");
 206                                 return value;
 207                         }
 208                         /*
 209                          * otherwise we matched a substring of another feature;
 210                          * keep looking
 211                          */
 212                 }
 213                 feature_list = found + 1;
 214         }
 215         return NULL;
 216 }
 217
 218 int parse_feature_request(const char *feature_list, const char *feature)
 219 {
 220         return !!parse_feature_value(feature_list, feature, NULL);
 221 }
 222
 223 const char *server_feature_value(const char *feature, int *len)
 224 {
 225         return parse_feature_value(server_capabilities, feature, len);
 226 }
 227
 228 int server_supports(const char *feature)
 229 {
 230         return !!server_feature_value(feature, NULL);
 231 }
 232
 233 enum protocol {
 234         PROTO_LOCAL = 1,
 235         PROTO_FILE,
 236         PROTO_SSH,
 237         PROTO_GIT
 238 };
 239
 240 int url_is_local_not_ssh(const char *url)
 241 {
 242         const char *colon = strchr(url, ':');
 243         const char *slash = strchr(url, '/');
 244         return !colon || (slash && slash < colon) ||
 245                 has_dos_drive_prefix(url);
 246 }
 247
 248 static const char *prot_name(enum protocol protocol)
 249 {
 250         switch (protocol) {
 251                 case PROTO_LOCAL:
 252                 case PROTO_FILE:
 253                         return "file";
 254                 case PROTO_SSH:
 255                         return "ssh";
 256                 case PROTO_GIT:
 257                         return "git";
 258                 default:
 259                         return "unkown protocol";
 260         }
 261 }
 262
 263 static enum protocol get_protocol(const char *name)
 264 {
 265         if (!strcmp(name, "ssh"))
 266                 return PROTO_SSH;
 267         if (!strcmp(name, "git"))
 268                 return PROTO_GIT;
 269         if (!strcmp(name, "git+ssh"))
 270                 return PROTO_SSH;
 271         if (!strcmp(name, "ssh+git"))
 272                 return PROTO_SSH;
 273         if (!strcmp(name, "file"))
 274                 return PROTO_FILE;
 275         die("I don't handle protocol '%s'", name);
 276 }
 277
 278 #define STR_(s) # s
 279 #define STR(s)  STR_(s)
 280
 281 static void get_host_and_port(char **host, const char **port)
 282 {
 283         char *colon, *end;
 284
 285         if (*host[0] == '[') {
 286                 end = strchr(*host + 1, ']');
 287                 if (end) {
 288                         *end = 0;
 289                         end++;
 290                         (*host)++;
 291                 } else
 292                         end = *host;
 293         } else
 294                 end = *host;
 295         colon = strchr(end, ':');
 296
 297         if (colon) {
 298                 *colon = 0;
 299                 *port = colon + 1;
 300         }
 301 }
 302
 303 static void enable_keepalive(int sockfd)
 304 {
 305         int ka = 1;
 306
 307         if (setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, &ka, sizeof(ka)) < 0)
 308                 fprintf(stderr, "unable to set SO_KEEPALIVE on socket: %s\n",
 309                         strerror(errno));
 310 }
 311
 312 #ifndef NO_IPV6
 313
 314 static const char *ai_name(const struct addrinfo *ai)
 315 {
 316         static char addr[NI_MAXHOST];
 317         if (getnameinfo(ai->ai_addr, ai->ai_addrlen, addr, sizeof(addr), NULL, 0,
 318                         NI_NUMERICHOST) != 0)
 319                 strcpy(addr, "(unknown)");
 320
 321         return addr;
 322 }
 323
 324 /*
 325  * Returns a connected socket() fd, or else die()s.
 326  */
 327 static int git_tcp_connect_sock(char *host, int flags)
 328 {
 329         struct strbuf error_message = STRBUF_INIT;
 330         int sockfd = -1;
 331         const char *port = STR(DEFAULT_GIT_PORT);
 332         struct addrinfo hints, *ai0, *ai;
 333         int gai;
 334         int cnt = 0;
 335
 336         get_host_and_port(&host, &port);
 337         if (!*port)
 338                 port = "<none>";
 339
 340         memset(&hints, 0, sizeof(hints));
 341         hints.ai_socktype = SOCK_STREAM;
 342         hints.ai_protocol = IPPROTO_TCP;
 343
 344         if (flags & CONNECT_VERBOSE)
 345                 fprintf(stderr, "Looking up %s ... ", host);
 346
 347         gai = getaddrinfo(host, port, &hints, &ai);
 348         if (gai)
 349                 die("Unable to look up %s (port %s) (%s)", host, port, gai_strerror(gai));
 350
 351         if (flags & CONNECT_VERBOSE)
 352                 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 353
 354         for (ai0 = ai; ai; ai = ai->ai_next, cnt++) {
 355                 sockfd = socket(ai->ai_family,
 356                                 ai->ai_socktype, ai->ai_protocol);
 357                 if ((sockfd < 0) ||
 358                     (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0)) {
 359                         strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 360                                     host, cnt, ai_name(ai), strerror(errno));
 361                         if (0 <= sockfd)
 362                                 close(sockfd);
 363                         sockfd = -1;
 364                         continue;
 365                 }
 366                 if (flags & CONNECT_VERBOSE)
 367                         fprintf(stderr, "%s ", ai_name(ai));
 368                 break;
 369         }
 370
 371         freeaddrinfo(ai0);
 372
 373         if (sockfd < 0)
 374                 die("unable to connect to %s:\n%s", host, error_message.buf);
 375
 376         enable_keepalive(sockfd);
 377
 378         if (flags & CONNECT_VERBOSE)
 379                 fprintf(stderr, "done.\n");
 380
 381         strbuf_release(&error_message);
 382
 383         return sockfd;
 384 }
 385
 386 #else /* NO_IPV6 */
 387
 388 /*
 389  * Returns a connected socket() fd, or else die()s.
 390  */
 391 static int git_tcp_connect_sock(char *host, int flags)
 392 {
 393         struct strbuf error_message = STRBUF_INIT;
 394         int sockfd = -1;
 395         const char *port = STR(DEFAULT_GIT_PORT);
 396         char *ep;
 397         struct hostent *he;
 398         struct sockaddr_in sa;
 399         char **ap;
 400         unsigned int nport;
 401         int cnt;
 402
 403         get_host_and_port(&host, &port);
 404
 405         if (flags & CONNECT_VERBOSE)
 406                 fprintf(stderr, "Looking up %s ... ", host);
 407
 408         he = gethostbyname(host);
 409         if (!he)
 410                 die("Unable to look up %s (%s)", host, hstrerror(h_errno));
 411         nport = strtoul(port, &ep, 10);
 412         if ( ep == port || *ep ) {
 413                 /* Not numeric */
 414                 struct servent *se = getservbyname(port,"tcp");
 415                 if ( !se )
 416                         die("Unknown port %s", port);
 417                 nport = se->s_port;
 418         }
 419
 420         if (flags & CONNECT_VERBOSE)
 421                 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 422
 423         for (cnt = 0, ap = he->h_addr_list; *ap; ap++, cnt++) {
 424                 memset(&sa, 0, sizeof sa);
 425                 sa.sin_family = he->h_addrtype;
 426                 sa.sin_port = htons(nport);
 427                 memcpy(&sa.sin_addr, *ap, he->h_length);
 428
 429                 sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 430                 if ((sockfd < 0) ||
 431                     connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 432                         strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 433                                 host,
 434                                 cnt,
 435                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr),
 436                                 strerror(errno));
 437                         if (0 <= sockfd)
 438                                 close(sockfd);
 439                         sockfd = -1;
 440                         continue;
 441                 }
 442                 if (flags & CONNECT_VERBOSE)
 443                         fprintf(stderr, "%s ",
 444                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr));
 445                 break;
 446         }
 447
 448         if (sockfd < 0)
 449                 die("unable to connect to %s:\n%s", host, error_message.buf);
 450
 451         enable_keepalive(sockfd);
 452
 453         if (flags & CONNECT_VERBOSE)
 454                 fprintf(stderr, "done.\n");
 455
 456         return sockfd;
 457 }
 458
 459 #endif /* NO_IPV6 */
 460
 461
 462 static void git_tcp_connect(int fd[2], char *host, int flags)
 463 {
 464         int sockfd = git_tcp_connect_sock(host, flags);
 465
 466         fd[0] = sockfd;
 467         fd[1] = dup(sockfd);
 468 }
 469
 470
 471 static char *git_proxy_command;
 472
 473 static int git_proxy_command_options(const char *var, const char *value,
 474                 void *cb)
 475 {
 476         if (!strcmp(var, "core.gitproxy")) {
 477                 const char *for_pos;
 478                 int matchlen = -1;
 479                 int hostlen;
 480                 const char *rhost_name = cb;
 481                 int rhost_len = strlen(rhost_name);
 482
 483                 if (git_proxy_command)
 484                         return 0;
 485                 if (!value)
 486                         return config_error_nonbool(var);
 487                 /* [core]
 488                  * ;# matches www.kernel.org as well
 489                  * gitproxy = netcatter-1 for kernel.org
 490                  * gitproxy = netcatter-2 for sample.xz
 491                  * gitproxy = netcatter-default
 492                  */
 493                 for_pos = strstr(value, " for ");
 494                 if (!for_pos)
 495                         /* matches everybody */
 496                         matchlen = strlen(value);
 497                 else {
 498                         hostlen = strlen(for_pos + 5);
 499                         if (rhost_len < hostlen)
 500                                 matchlen = -1;
 501                         else if (!strncmp(for_pos + 5,
 502                                           rhost_name + rhost_len - hostlen,
 503                                           hostlen) &&
 504                                  ((rhost_len == hostlen) ||
 505                                   rhost_name[rhost_len - hostlen -1] == '.'))
 506                                 matchlen = for_pos - value;
 507                         else
 508                                 matchlen = -1;
 509                 }
 510                 if (0 <= matchlen) {
 511                         /* core.gitproxy = none for kernel.org */
 512                         if (matchlen == 4 &&
 513                             !memcmp(value, "none", 4))
 514                                 matchlen = 0;
 515                         git_proxy_command = xmemdupz(value, matchlen);
 516                 }
 517                 return 0;
 518         }
 519
 520         return git_default_config(var, value, cb);
 521 }
 522
 523 static int git_use_proxy(const char *host)
 524 {
 525         git_proxy_command = getenv("GIT_PROXY_COMMAND");
 526         git_config(git_proxy_command_options, (void*)host);
 527         return (git_proxy_command && *git_proxy_command);
 528 }
 529
 530 static struct child_process *git_proxy_connect(int fd[2], char *host)
 531 {
 532         const char *port = STR(DEFAULT_GIT_PORT);
 533         const char **argv;
 534         struct child_process *proxy;
 535
 536         get_host_and_port(&host, &port);
 537
 538         argv = xmalloc(sizeof(*argv) * 4);
 539         argv[0] = git_proxy_command;
 540         argv[1] = host;
 541         argv[2] = port;
 542         argv[3] = NULL;
 543         proxy = xcalloc(1, sizeof(*proxy));
 544         proxy->argv = argv;
 545         proxy->in = -1;
 546         proxy->out = -1;
 547         if (start_command(proxy))
 548                 die("cannot start proxy %s", argv[0]);
 549         fd[0] = proxy->out; /* read from proxy stdout */
 550         fd[1] = proxy->in;  /* write to proxy stdin */
 551         return proxy;
 552 }
 553
 554 static const char *get_port_numeric(const char *p)
 555 {
 556         char *end;
 557         if (p) {
 558                 long port = strtol(p + 1, &end, 10);
 559                 if (end != p + 1 && *end == '\0' && 0 <= port && port < 65536) {
 560                         return p;
 561                 }
 562         }
 563
 564         return NULL;
 565 }
 566
 567 /*
 568  * Extract protocol and relevant parts from the specified connection URL.
 569  * The caller must free() the returned strings.
 570  */
 571 static enum protocol parse_connect_url(const char *url_orig, char **ret_host,
 572                                        char **ret_path)
 573 {
 574         char *url;
 575         char *host, *path;
 576         char *end;
 577         int separator = '/';
 578         enum protocol protocol = PROTO_LOCAL;
 579
 580         if (is_url(url_orig))
 581                 url = url_decode(url_orig);
 582         else
 583                 url = xstrdup(url_orig);
 584
 585         host = strstr(url, "://");
 586         if (host) {
 587                 *host = '\0';
 588                 protocol = get_protocol(url);
 589                 host += 3;
 590         } else {
 591                 host = url;
 592                 if (!url_is_local_not_ssh(url)) {
 593                         protocol = PROTO_SSH;
 594                         separator = ':';
 595                 }
 596         }
 597
 598         /*
 599          * Don't do destructive transforms as protocol code does
 600          * '[]' unwrapping in get_host_and_port()
 601          */
 602         if (host[0] == '[') {
 603                 end = strchr(host + 1, ']');
 604                 if (end) {
 605                         end++;
 606                 } else
 607                         end = host;
 608         } else
 609                 end = host;
 610
 611         if (protocol == PROTO_LOCAL)
 612                 path = end;
 613         else if (protocol == PROTO_FILE && has_dos_drive_prefix(end))
 614                 path = end; /* "file://$(pwd)" may be "file://C:/projects/repo" */
 615         else
 616                 path = strchr(end, separator);
 617
 618         if (!path || !*path)
 619                 die("No path specified. See 'man git-pull' for valid url syntax");
 620
 621         /*
 622          * null-terminate hostname and point path to ~ for URL's like this:
 623          *    ssh://host.xz/~user/repo
 624          */
 625
 626         end = path; /* Need to \0 terminate host here */
 627         if (separator == ':')
 628                 path++; /* path starts after ':' */
 629         if (protocol == PROTO_GIT || protocol == PROTO_SSH) {
 630                 if (path[1] == '~')
 631                         path++;
 632         }
 633
 634         path = xstrdup(path);
 635         *end = '\0';
 636
 637         *ret_host = xstrdup(host);
 638         *ret_path = path;
 639         free(url);
 640         return protocol;
 641 }
 642
 643 static struct child_process no_fork;
 644
 645 /*
 646  * This returns a dummy child_process if the transport protocol does not
 647  * need fork(2), or a struct child_process object if it does.  Once done,
 648  * finish the connection with finish_connect() with the value returned from
 649  * this function (it is safe to call finish_connect() with NULL to support
 650  * the former case).
 651  *
 652  * If it returns, the connect is successful; it just dies on errors (this
 653  * will hopefully be changed in a libification effort, to return NULL when
 654  * the connection failed).
 655  */
 656 struct child_process *git_connect(int fd[2], const char *url,
 657                                   const char *prog, int flags)
 658 {
 659         char *hostandport, *path;
 660         struct child_process *conn = &no_fork;
 661         enum protocol protocol;
 662         const char **arg;
 663         struct strbuf cmd = STRBUF_INIT;
 664
 665         /* Without this we cannot rely on waitpid() to tell
 666          * what happened to our children.
 667          */
 668         signal(SIGCHLD, SIG_DFL);
 669
 670         protocol = parse_connect_url(url, &hostandport, &path);
 671         if (flags & CONNECT_DIAG_URL) {
 672                 printf("Diag: url=%s\n", url ? url : "NULL");
 673                 printf("Diag: protocol=%s\n", prot_name(protocol));
 674                 printf("Diag: hostandport=%s\n", hostandport ? hostandport : "NULL");
 675                 printf("Diag: path=%s\n", path ? path : "NULL");
 676                 conn = NULL;
 677         } else if (protocol == PROTO_GIT) {
 678                 /* These underlying connection commands die() if they
 679                  * cannot connect.
 680                  */
 681                 char *target_host = xstrdup(hostandport);
 682                 if (git_use_proxy(hostandport))
 683                         conn = git_proxy_connect(fd, hostandport);
 684                 else
 685                         git_tcp_connect(fd, hostandport, flags);
 686                 /*
 687                  * Separate original protocol components prog and path
 688                  * from extended host header with a NUL byte.
 689                  *
 690                  * Note: Do not add any other headers here!  Doing so
 691                  * will cause older git-daemon servers to crash.
 692                  */
 693                 packet_write(fd[1],
 694                              "%s %s%chost=%s%c",
 695                              prog, path, 0,
 696                              target_host, 0);
 697                 free(target_host);
 698         } else {
 699                 conn = xcalloc(1, sizeof(*conn));
 700
 701                 strbuf_addstr(&cmd, prog);
 702                 strbuf_addch(&cmd, ' ');
 703                 sq_quote_buf(&cmd, path);
 704
 705                 conn->in = conn->out = -1;
 706                 conn->argv = arg = xcalloc(7, sizeof(*arg));
 707                 if (protocol == PROTO_SSH) {
 708                         const char *ssh = getenv("GIT_SSH");
 709                         int putty = ssh && strcasestr(ssh, "plink");
 710                         char *ssh_host = hostandport;
 711                         const char *port = NULL;
 712                         get_host_and_port(&ssh_host, &port);
 713                         port = get_port_numeric(port);
 714
 715                         if (!ssh) ssh = "ssh";
 716
 717                         *arg++ = ssh;
 718                         if (putty && !strcasestr(ssh, "tortoiseplink"))
 719                                 *arg++ = "-batch";
 720                         if (port) {
 721                                 /* P is for PuTTY, p is for OpenSSH */
 722                                 *arg++ = putty ? "-P" : "-p";
 723                                 *arg++ = port;
 724                         }
 725                         *arg++ = ssh_host;
 726                 }       else {
 727                         /* remove repo-local variables from the environment */
 728                         conn->env = local_repo_env;
 729                         conn->use_shell = 1;
 730                 }
 731                 *arg++ = cmd.buf;
 732                 *arg = NULL;
 733
 734                 if (start_command(conn))
 735                         die("unable to fork");
 736
 737                 fd[0] = conn->out; /* read from child's stdout */
 738                 fd[1] = conn->in;  /* write to child's stdin */
 739                 strbuf_release(&cmd);
 740         }
 741         free(hostandport);
 742         free(path);
 743         return conn;
 744 }
 745
 746 int git_connection_is_socket(struct child_process *conn)
 747 {
 748         return conn == &no_fork;
 749 }
 750
 751 int finish_connect(struct child_process *conn)
 752 {
 753         int code;
 754         if (!conn || git_connection_is_socket(conn))
 755                 return 0;
 756
 757         code = finish_command(conn);
 758         free(conn->argv);
 759         free(conn);
 760         return code;
 761 }