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