connect.c

   1 #include "git-compat-util.h"
   2 #include "cache.h"
   3 #include "config.h"
   4 #include "pkt-line.h"
   5 #include "quote.h"
   6 #include "refs.h"
   7 #include "run-command.h"
   8 #include "remote.h"
   9 #include "connect.h"
  10 #include "url.h"
  11 #include "string-list.h"
  12 #include "oid-array.h"
  13 #include "transport.h"
  14 #include "strbuf.h"
  15 #include "version.h"
  16 #include "protocol.h"
  17 #include "alias.h"
  18
  19 static char *server_capabilities_v1;
  20 static struct strvec server_capabilities_v2 = STRVEC_INIT;
  21 static const char *next_server_feature_value(const char *feature, int *len, int *offset);
  22
  23 static int check_ref(const char *name, unsigned int flags)
  24 {
  25         if (!flags)
  26                 return 1;
  27
  28         if (!skip_prefix(name, "refs/", &name))
  29                 return 0;
  30
  31         /* REF_NORMAL means that we don't want the magic fake tag refs */
  32         if ((flags & REF_NORMAL) && check_refname_format(name, 0))
  33                 return 0;
  34
  35         /* REF_HEADS means that we want regular branch heads */
  36         if ((flags & REF_HEADS) && starts_with(name, "heads/"))
  37                 return 1;
  38
  39         /* REF_TAGS means that we want tags */
  40         if ((flags & REF_TAGS) && starts_with(name, "tags/"))
  41                 return 1;
  42
  43         /* All type bits clear means that we are ok with anything */
  44         return !(flags & ~REF_NORMAL);
  45 }
  46
  47 int check_ref_type(const struct ref *ref, int flags)
  48 {
  49         return check_ref(ref->name, flags);
  50 }
  51
  52 static NORETURN void die_initial_contact(int unexpected)
  53 {
  54         /*
  55          * A hang-up after seeing some response from the other end
  56          * means that it is unexpected, as we know the other end is
  57          * willing to talk to us.  A hang-up before seeing any
  58          * response does not necessarily mean an ACL problem, though.
  59          */
  60         if (unexpected)
  61                 die(_("the remote end hung up upon initial contact"));
  62         else
  63                 die(_("Could not read from remote repository.\n\n"
  64                       "Please make sure you have the correct access rights\n"
  65                       "and the repository exists."));
  66 }
  67
  68 /* Checks if the server supports the capability 'c' */
  69 int server_supports_v2(const char *c, int die_on_error)
  70 {
  71         int i;
  72
  73         for (i = 0; i < server_capabilities_v2.nr; i++) {
  74                 const char *out;
  75                 if (skip_prefix(server_capabilities_v2.v[i], c, &out) &&
  76                     (!*out || *out == '='))
  77                         return 1;
  78         }
  79
  80         if (die_on_error)
  81                 die(_("server doesn't support '%s'"), c);
  82
  83         return 0;
  84 }
  85
  86 int server_feature_v2(const char *c, const char **v)
  87 {
  88         int i;
  89
  90         for (i = 0; i < server_capabilities_v2.nr; i++) {
  91                 const char *out;
  92                 if (skip_prefix(server_capabilities_v2.v[i], c, &out) &&
  93                     (*out == '=')) {
  94                         *v = out + 1;
  95                         return 1;
  96                 }
  97         }
  98         return 0;
  99 }
 100
 101 int server_supports_feature(const char *c, const char *feature,
 102                             int die_on_error)
 103 {
 104         int i;
 105
 106         for (i = 0; i < server_capabilities_v2.nr; i++) {
 107                 const char *out;
 108                 if (skip_prefix(server_capabilities_v2.v[i], c, &out) &&
 109                     (!*out || *(out++) == '=')) {
 110                         if (parse_feature_request(out, feature))
 111                                 return 1;
 112                         else
 113                                 break;
 114                 }
 115         }
 116
 117         if (die_on_error)
 118                 die(_("server doesn't support feature '%s'"), feature);
 119
 120         return 0;
 121 }
 122
 123 static void process_capabilities_v2(struct packet_reader *reader)
 124 {
 125         while (packet_reader_read(reader) == PACKET_READ_NORMAL)
 126                 strvec_push(&server_capabilities_v2, reader->line);
 127
 128         if (reader->status != PACKET_READ_FLUSH)
 129                 die(_("expected flush after capabilities"));
 130 }
 131
 132 enum protocol_version discover_version(struct packet_reader *reader)
 133 {
 134         enum protocol_version version = protocol_unknown_version;
 135
 136         /*
 137          * Peek the first line of the server's response to
 138          * determine the protocol version the server is speaking.
 139          */
 140         switch (packet_reader_peek(reader)) {
 141         case PACKET_READ_EOF:
 142                 die_initial_contact(0);
 143         case PACKET_READ_FLUSH:
 144         case PACKET_READ_DELIM:
 145         case PACKET_READ_RESPONSE_END:
 146                 version = protocol_v0;
 147                 break;
 148         case PACKET_READ_NORMAL:
 149                 version = determine_protocol_version_client(reader->line);
 150                 break;
 151         }
 152
 153         switch (version) {
 154         case protocol_v2:
 155                 process_capabilities_v2(reader);
 156                 break;
 157         case protocol_v1:
 158                 /* Read the peeked version line */
 159                 packet_reader_read(reader);
 160                 break;
 161         case protocol_v0:
 162                 break;
 163         case protocol_unknown_version:
 164                 BUG("unknown protocol version");
 165         }
 166
 167         return version;
 168 }
 169
 170 static void parse_one_symref_info(struct string_list *symref, const char *val, int len)
 171 {
 172         char *sym, *target;
 173         struct string_list_item *item;
 174
 175         if (!len)
 176                 return; /* just "symref" */
 177         /* e.g. "symref=HEAD:refs/heads/master" */
 178         sym = xmemdupz(val, len);
 179         target = strchr(sym, ':');
 180         if (!target)
 181                 /* just "symref=something" */
 182                 goto reject;
 183         *(target++) = '\0';
 184         if (check_refname_format(sym, REFNAME_ALLOW_ONELEVEL) ||
 185             check_refname_format(target, REFNAME_ALLOW_ONELEVEL))
 186                 /* "symref=bogus:pair */
 187                 goto reject;
 188         item = string_list_append_nodup(symref, sym);
 189         item->util = target;
 190         return;
 191 reject:
 192         free(sym);
 193         return;
 194 }
 195
 196 static void annotate_refs_with_symref_info(struct ref *ref)
 197 {
 198         struct string_list symref = STRING_LIST_INIT_DUP;
 199         int offset = 0;
 200
 201         while (1) {
 202                 int len;
 203                 const char *val;
 204
 205                 val = next_server_feature_value("symref", &len, &offset);
 206                 if (!val)
 207                         break;
 208                 parse_one_symref_info(&symref, val, len);
 209         }
 210         string_list_sort(&symref);
 211
 212         for (; ref; ref = ref->next) {
 213                 struct string_list_item *item;
 214                 item = string_list_lookup(&symref, ref->name);
 215                 if (!item)
 216                         continue;
 217                 ref->symref = xstrdup((char *)item->util);
 218         }
 219         string_list_clear(&symref, 0);
 220 }
 221
 222 static void process_capabilities(struct packet_reader *reader, int *linelen)
 223 {
 224         const char *feat_val;
 225         int feat_len;
 226         const char *line = reader->line;
 227         int nul_location = strlen(line);
 228         if (nul_location == *linelen)
 229                 return;
 230         server_capabilities_v1 = xstrdup(line + nul_location + 1);
 231         *linelen = nul_location;
 232
 233         feat_val = server_feature_value("object-format", &feat_len);
 234         if (feat_val) {
 235                 char *hash_name = xstrndup(feat_val, feat_len);
 236                 int hash_algo = hash_algo_by_name(hash_name);
 237                 if (hash_algo != GIT_HASH_UNKNOWN)
 238                         reader->hash_algo = &hash_algos[hash_algo];
 239                 free(hash_name);
 240         } else {
 241                 reader->hash_algo = &hash_algos[GIT_HASH_SHA1];
 242         }
 243 }
 244
 245 static int process_dummy_ref(const struct packet_reader *reader)
 246 {
 247         const char *line = reader->line;
 248         struct object_id oid;
 249         const char *name;
 250
 251         if (parse_oid_hex_algop(line, &oid, &name, reader->hash_algo))
 252                 return 0;
 253         if (*name != ' ')
 254                 return 0;
 255         name++;
 256
 257         return oideq(&null_oid, &oid) && !strcmp(name, "capabilities^{}");
 258 }
 259
 260 static void check_no_capabilities(const char *line, int len)
 261 {
 262         if (strlen(line) != len)
 263                 warning(_("ignoring capabilities after first line '%s'"),
 264                         line + strlen(line));
 265 }
 266
 267 static int process_ref(const struct packet_reader *reader, int len,
 268                        struct ref ***list, unsigned int flags,
 269                        struct oid_array *extra_have)
 270 {
 271         const char *line = reader->line;
 272         struct object_id old_oid;
 273         const char *name;
 274
 275         if (parse_oid_hex_algop(line, &old_oid, &name, reader->hash_algo))
 276                 return 0;
 277         if (*name != ' ')
 278                 return 0;
 279         name++;
 280
 281         if (extra_have && !strcmp(name, ".have")) {
 282                 oid_array_append(extra_have, &old_oid);
 283         } else if (!strcmp(name, "capabilities^{}")) {
 284                 die(_("protocol error: unexpected capabilities^{}"));
 285         } else if (check_ref(name, flags)) {
 286                 struct ref *ref = alloc_ref(name);
 287                 oidcpy(&ref->old_oid, &old_oid);
 288                 **list = ref;
 289                 *list = &ref->next;
 290         }
 291         check_no_capabilities(line, len);
 292         return 1;
 293 }
 294
 295 static int process_shallow(const struct packet_reader *reader, int len,
 296                            struct oid_array *shallow_points)
 297 {
 298         const char *line = reader->line;
 299         const char *arg;
 300         struct object_id old_oid;
 301
 302         if (!skip_prefix(line, "shallow ", &arg))
 303                 return 0;
 304
 305         if (get_oid_hex_algop(arg, &old_oid, reader->hash_algo))
 306                 die(_("protocol error: expected shallow sha-1, got '%s'"), arg);
 307         if (!shallow_points)
 308                 die(_("repository on the other end cannot be shallow"));
 309         oid_array_append(shallow_points, &old_oid);
 310         check_no_capabilities(line, len);
 311         return 1;
 312 }
 313
 314 enum get_remote_heads_state {
 315         EXPECTING_FIRST_REF = 0,
 316         EXPECTING_REF,
 317         EXPECTING_SHALLOW,
 318         EXPECTING_DONE,
 319 };
 320
 321 /*
 322  * Read all the refs from the other end
 323  */
 324 struct ref **get_remote_heads(struct packet_reader *reader,
 325                               struct ref **list, unsigned int flags,
 326                               struct oid_array *extra_have,
 327                               struct oid_array *shallow_points)
 328 {
 329         struct ref **orig_list = list;
 330         int len = 0;
 331         enum get_remote_heads_state state = EXPECTING_FIRST_REF;
 332
 333         *list = NULL;
 334
 335         while (state != EXPECTING_DONE) {
 336                 switch (packet_reader_read(reader)) {
 337                 case PACKET_READ_EOF:
 338                         die_initial_contact(1);
 339                 case PACKET_READ_NORMAL:
 340                         len = reader->pktlen;
 341                         break;
 342                 case PACKET_READ_FLUSH:
 343                         state = EXPECTING_DONE;
 344                         break;
 345                 case PACKET_READ_DELIM:
 346                 case PACKET_READ_RESPONSE_END:
 347                         die(_("invalid packet"));
 348                 }
 349
 350                 switch (state) {
 351                 case EXPECTING_FIRST_REF:
 352                         process_capabilities(reader, &len);
 353                         if (process_dummy_ref(reader)) {
 354                                 state = EXPECTING_SHALLOW;
 355                                 break;
 356                         }
 357                         state = EXPECTING_REF;
 358                         /* fallthrough */
 359                 case EXPECTING_REF:
 360                         if (process_ref(reader, len, &list, flags, extra_have))
 361                                 break;
 362                         state = EXPECTING_SHALLOW;
 363                         /* fallthrough */
 364                 case EXPECTING_SHALLOW:
 365                         if (process_shallow(reader, len, shallow_points))
 366                                 break;
 367                         die(_("protocol error: unexpected '%s'"), reader->line);
 368                 case EXPECTING_DONE:
 369                         break;
 370                 }
 371         }
 372
 373         annotate_refs_with_symref_info(*orig_list);
 374
 375         return list;
 376 }
 377
 378 /* Returns 1 when a valid ref has been added to `list`, 0 otherwise */
 379 static int process_ref_v2(struct packet_reader *reader, struct ref ***list)
 380 {
 381         int ret = 1;
 382         int i = 0;
 383         struct object_id old_oid;
 384         struct ref *ref;
 385         struct string_list line_sections = STRING_LIST_INIT_DUP;
 386         const char *end;
 387         const char *line = reader->line;
 388
 389         /*
 390          * Ref lines have a number of fields which are space deliminated.  The
 391          * first field is the OID of the ref.  The second field is the ref
 392          * name.  Subsequent fields (symref-target and peeled) are optional and
 393          * don't have a particular order.
 394          */
 395         if (string_list_split(&line_sections, line, ' ', -1) < 2) {
 396                 ret = 0;
 397                 goto out;
 398         }
 399
 400         if (parse_oid_hex_algop(line_sections.items[i++].string, &old_oid, &end, reader->hash_algo) ||
 401             *end) {
 402                 ret = 0;
 403                 goto out;
 404         }
 405
 406         ref = alloc_ref(line_sections.items[i++].string);
 407
 408         memcpy(ref->old_oid.hash, old_oid.hash, reader->hash_algo->rawsz);
 409         **list = ref;
 410         *list = &ref->next;
 411
 412         for (; i < line_sections.nr; i++) {
 413                 const char *arg = line_sections.items[i].string;
 414                 if (skip_prefix(arg, "symref-target:", &arg))
 415                         ref->symref = xstrdup(arg);
 416
 417                 if (skip_prefix(arg, "peeled:", &arg)) {
 418                         struct object_id peeled_oid;
 419                         char *peeled_name;
 420                         struct ref *peeled;
 421                         if (parse_oid_hex_algop(arg, &peeled_oid, &end,
 422                                                 reader->hash_algo) || *end) {
 423                                 ret = 0;
 424                                 goto out;
 425                         }
 426
 427                         peeled_name = xstrfmt("%s^{}", ref->name);
 428                         peeled = alloc_ref(peeled_name);
 429
 430                         memcpy(peeled->old_oid.hash, peeled_oid.hash,
 431                                reader->hash_algo->rawsz);
 432                         **list = peeled;
 433                         *list = &peeled->next;
 434
 435                         free(peeled_name);
 436                 }
 437         }
 438
 439 out:
 440         string_list_clear(&line_sections, 0);
 441         return ret;
 442 }
 443
 444 void check_stateless_delimiter(int stateless_rpc,
 445                               struct packet_reader *reader,
 446                               const char *error)
 447 {
 448         if (!stateless_rpc)
 449                 return; /* not in stateless mode, no delimiter expected */
 450         if (packet_reader_read(reader) != PACKET_READ_RESPONSE_END)
 451                 die("%s", error);
 452 }
 453
 454 struct ref **get_remote_refs(int fd_out, struct packet_reader *reader,
 455                              struct ref **list, int for_push,
 456                              const struct strvec *ref_prefixes,
 457                              const struct string_list *server_options,
 458                              int stateless_rpc)
 459 {
 460         int i;
 461         const char *hash_name;
 462         *list = NULL;
 463
 464         if (server_supports_v2("ls-refs", 1))
 465                 packet_write_fmt(fd_out, "command=ls-refs\n");
 466
 467         if (server_supports_v2("agent", 0))
 468                 packet_write_fmt(fd_out, "agent=%s", git_user_agent_sanitized());
 469
 470         if (server_feature_v2("object-format", &hash_name)) {
 471                 int hash_algo = hash_algo_by_name(hash_name);
 472                 if (hash_algo == GIT_HASH_UNKNOWN)
 473                         die(_("unknown object format '%s' specified by server"), hash_name);
 474                 reader->hash_algo = &hash_algos[hash_algo];
 475                 packet_write_fmt(fd_out, "object-format=%s", reader->hash_algo->name);
 476         } else {
 477                 reader->hash_algo = &hash_algos[GIT_HASH_SHA1];
 478         }
 479
 480         if (server_options && server_options->nr &&
 481             server_supports_v2("server-option", 1))
 482                 for (i = 0; i < server_options->nr; i++)
 483                         packet_write_fmt(fd_out, "server-option=%s",
 484                                          server_options->items[i].string);
 485
 486         packet_delim(fd_out);
 487         /* When pushing we don't want to request the peeled tags */
 488         if (!for_push)
 489                 packet_write_fmt(fd_out, "peel\n");
 490         packet_write_fmt(fd_out, "symrefs\n");
 491         for (i = 0; ref_prefixes && i < ref_prefixes->nr; i++) {
 492                 packet_write_fmt(fd_out, "ref-prefix %s\n",
 493                                  ref_prefixes->v[i]);
 494         }
 495         packet_flush(fd_out);
 496
 497         /* Process response from server */
 498         while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
 499                 if (!process_ref_v2(reader, &list))
 500                         die(_("invalid ls-refs response: %s"), reader->line);
 501         }
 502
 503         if (reader->status != PACKET_READ_FLUSH)
 504                 die(_("expected flush after ref listing"));
 505
 506         check_stateless_delimiter(stateless_rpc, reader,
 507                                   _("expected response end packet after ref listing"));
 508
 509         return list;
 510 }
 511
 512 const char *parse_feature_value(const char *feature_list, const char *feature, int *lenp, int *offset)
 513 {
 514         int len;
 515
 516         if (!feature_list)
 517                 return NULL;
 518
 519         len = strlen(feature);
 520         if (offset)
 521                 feature_list += *offset;
 522         while (*feature_list) {
 523                 const char *found = strstr(feature_list, feature);
 524                 if (!found)
 525                         return NULL;
 526                 if (feature_list == found || isspace(found[-1])) {
 527                         const char *value = found + len;
 528                         /* feature with no value (e.g., "thin-pack") */
 529                         if (!*value || isspace(*value)) {
 530                                 if (lenp)
 531                                         *lenp = 0;
 532                                 return value;
 533                         }
 534                         /* feature with a value (e.g., "agent=git/1.2.3") */
 535                         else if (*value == '=') {
 536                                 int end;
 537
 538                                 value++;
 539                                 end = strcspn(value, " \t\n");
 540                                 if (lenp)
 541                                         *lenp = end;
 542                                 if (offset)
 543                                         *offset = value + end - feature_list;
 544                                 return value;
 545                         }
 546                         /*
 547                          * otherwise we matched a substring of another feature;
 548                          * keep looking
 549                          */
 550                 }
 551                 feature_list = found + 1;
 552         }
 553         return NULL;
 554 }
 555
 556 int server_supports_hash(const char *desired, int *feature_supported)
 557 {
 558         int offset = 0;
 559         int len;
 560         const char *hash;
 561
 562         hash = next_server_feature_value("object-format", &len, &offset);
 563         if (feature_supported)
 564                 *feature_supported = !!hash;
 565         if (!hash) {
 566                 hash = hash_algos[GIT_HASH_SHA1].name;
 567                 len = strlen(hash);
 568         }
 569         while (hash) {
 570                 if (!xstrncmpz(desired, hash, len))
 571                         return 1;
 572
 573                 hash = next_server_feature_value("object-format", &len, &offset);
 574         }
 575         return 0;
 576 }
 577
 578 int parse_feature_request(const char *feature_list, const char *feature)
 579 {
 580         return !!parse_feature_value(feature_list, feature, NULL, NULL);
 581 }
 582
 583 static const char *next_server_feature_value(const char *feature, int *len, int *offset)
 584 {
 585         return parse_feature_value(server_capabilities_v1, feature, len, offset);
 586 }
 587
 588 const char *server_feature_value(const char *feature, int *len)
 589 {
 590         return parse_feature_value(server_capabilities_v1, feature, len, NULL);
 591 }
 592
 593 int server_supports(const char *feature)
 594 {
 595         return !!server_feature_value(feature, NULL);
 596 }
 597
 598 enum protocol {
 599         PROTO_LOCAL = 1,
 600         PROTO_FILE,
 601         PROTO_SSH,
 602         PROTO_GIT
 603 };
 604
 605 int url_is_local_not_ssh(const char *url)
 606 {
 607         const char *colon = strchr(url, ':');
 608         const char *slash = strchr(url, '/');
 609         return !colon || (slash && slash < colon) ||
 610                 (has_dos_drive_prefix(url) && is_valid_path(url));
 611 }
 612
 613 static const char *prot_name(enum protocol protocol)
 614 {
 615         switch (protocol) {
 616                 case PROTO_LOCAL:
 617                 case PROTO_FILE:
 618                         return "file";
 619                 case PROTO_SSH:
 620                         return "ssh";
 621                 case PROTO_GIT:
 622                         return "git";
 623                 default:
 624                         return "unknown protocol";
 625         }
 626 }
 627
 628 static enum protocol get_protocol(const char *name)
 629 {
 630         if (!strcmp(name, "ssh"))
 631                 return PROTO_SSH;
 632         if (!strcmp(name, "git"))
 633                 return PROTO_GIT;
 634         if (!strcmp(name, "git+ssh")) /* deprecated - do not use */
 635                 return PROTO_SSH;
 636         if (!strcmp(name, "ssh+git")) /* deprecated - do not use */
 637                 return PROTO_SSH;
 638         if (!strcmp(name, "file"))
 639                 return PROTO_FILE;
 640         die(_("protocol '%s' is not supported"), name);
 641 }
 642
 643 static char *host_end(char **hoststart, int removebrackets)
 644 {
 645         char *host = *hoststart;
 646         char *end;
 647         char *start = strstr(host, "@[");
 648         if (start)
 649                 start++; /* Jump over '@' */
 650         else
 651                 start = host;
 652         if (start[0] == '[') {
 653                 end = strchr(start + 1, ']');
 654                 if (end) {
 655                         if (removebrackets) {
 656                                 *end = 0;
 657                                 memmove(start, start + 1, end - start);
 658                                 end++;
 659                         }
 660                 } else
 661                         end = host;
 662         } else
 663                 end = host;
 664         return end;
 665 }
 666
 667 #define STR_(s) # s
 668 #define STR(s)  STR_(s)
 669
 670 static void get_host_and_port(char **host, const char **port)
 671 {
 672         char *colon, *end;
 673         end = host_end(host, 1);
 674         colon = strchr(end, ':');
 675         if (colon) {
 676                 long portnr = strtol(colon + 1, &end, 10);
 677                 if (end != colon + 1 && *end == '\0' && 0 <= portnr && portnr < 65536) {
 678                         *colon = 0;
 679                         *port = colon + 1;
 680                 } else if (!colon[1]) {
 681                         *colon = 0;
 682                 }
 683         }
 684 }
 685
 686 static void enable_keepalive(int sockfd)
 687 {
 688         int ka = 1;
 689
 690         if (setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, &ka, sizeof(ka)) < 0)
 691                 error_errno(_("unable to set SO_KEEPALIVE on socket"));
 692 }
 693
 694 #ifndef NO_IPV6
 695
 696 static const char *ai_name(const struct addrinfo *ai)
 697 {
 698         static char addr[NI_MAXHOST];
 699         if (getnameinfo(ai->ai_addr, ai->ai_addrlen, addr, sizeof(addr), NULL, 0,
 700                         NI_NUMERICHOST) != 0)
 701                 xsnprintf(addr, sizeof(addr), "(unknown)");
 702
 703         return addr;
 704 }
 705
 706 /*
 707  * Returns a connected socket() fd, or else die()s.
 708  */
 709 static int git_tcp_connect_sock(char *host, int flags)
 710 {
 711         struct strbuf error_message = STRBUF_INIT;
 712         int sockfd = -1;
 713         const char *port = STR(DEFAULT_GIT_PORT);
 714         struct addrinfo hints, *ai0, *ai;
 715         int gai;
 716         int cnt = 0;
 717
 718         get_host_and_port(&host, &port);
 719         if (!*port)
 720                 port = "<none>";
 721
 722         memset(&hints, 0, sizeof(hints));
 723         if (flags & CONNECT_IPV4)
 724                 hints.ai_family = AF_INET;
 725         else if (flags & CONNECT_IPV6)
 726                 hints.ai_family = AF_INET6;
 727         hints.ai_socktype = SOCK_STREAM;
 728         hints.ai_protocol = IPPROTO_TCP;
 729
 730         if (flags & CONNECT_VERBOSE)
 731                 fprintf(stderr, _("Looking up %s ... "), host);
 732
 733         gai = getaddrinfo(host, port, &hints, &ai);
 734         if (gai)
 735                 die(_("unable to look up %s (port %s) (%s)"), host, port, gai_strerror(gai));
 736
 737         if (flags & CONNECT_VERBOSE)
 738                 /* TRANSLATORS: this is the end of "Looking up %s ... " */
 739                 fprintf(stderr, _("done.\nConnecting to %s (port %s) ... "), host, port);
 740
 741         for (ai0 = ai; ai; ai = ai->ai_next, cnt++) {
 742                 sockfd = socket(ai->ai_family,
 743                                 ai->ai_socktype, ai->ai_protocol);
 744                 if ((sockfd < 0) ||
 745                     (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0)) {
 746                         strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 747                                     host, cnt, ai_name(ai), strerror(errno));
 748                         if (0 <= sockfd)
 749                                 close(sockfd);
 750                         sockfd = -1;
 751                         continue;
 752                 }
 753                 if (flags & CONNECT_VERBOSE)
 754                         fprintf(stderr, "%s ", ai_name(ai));
 755                 break;
 756         }
 757
 758         freeaddrinfo(ai0);
 759
 760         if (sockfd < 0)
 761                 die(_("unable to connect to %s:\n%s"), host, error_message.buf);
 762
 763         enable_keepalive(sockfd);
 764
 765         if (flags & CONNECT_VERBOSE)
 766                 /* TRANSLATORS: this is the end of "Connecting to %s (port %s) ... " */
 767                 fprintf_ln(stderr, _("done."));
 768
 769         strbuf_release(&error_message);
 770
 771         return sockfd;
 772 }
 773
 774 #else /* NO_IPV6 */
 775
 776 /*
 777  * Returns a connected socket() fd, or else die()s.
 778  */
 779 static int git_tcp_connect_sock(char *host, int flags)
 780 {
 781         struct strbuf error_message = STRBUF_INIT;
 782         int sockfd = -1;
 783         const char *port = STR(DEFAULT_GIT_PORT);
 784         char *ep;
 785         struct hostent *he;
 786         struct sockaddr_in sa;
 787         char **ap;
 788         unsigned int nport;
 789         int cnt;
 790
 791         get_host_and_port(&host, &port);
 792
 793         if (flags & CONNECT_VERBOSE)
 794                 fprintf(stderr, _("Looking up %s ... "), host);
 795
 796         he = gethostbyname(host);
 797         if (!he)
 798                 die(_("unable to look up %s (%s)"), host, hstrerror(h_errno));
 799         nport = strtoul(port, &ep, 10);
 800         if ( ep == port || *ep ) {
 801                 /* Not numeric */
 802                 struct servent *se = getservbyname(port,"tcp");
 803                 if ( !se )
 804                         die(_("unknown port %s"), port);
 805                 nport = se->s_port;
 806         }
 807
 808         if (flags & CONNECT_VERBOSE)
 809                 /* TRANSLATORS: this is the end of "Looking up %s ... " */
 810                 fprintf(stderr, _("done.\nConnecting to %s (port %s) ... "), host, port);
 811
 812         for (cnt = 0, ap = he->h_addr_list; *ap; ap++, cnt++) {
 813                 memset(&sa, 0, sizeof sa);
 814                 sa.sin_family = he->h_addrtype;
 815                 sa.sin_port = htons(nport);
 816                 memcpy(&sa.sin_addr, *ap, he->h_length);
 817
 818                 sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 819                 if ((sockfd < 0) ||
 820                     connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 821                         strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 822                                 host,
 823                                 cnt,
 824                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr),
 825                                 strerror(errno));
 826                         if (0 <= sockfd)
 827                                 close(sockfd);
 828                         sockfd = -1;
 829                         continue;
 830                 }
 831                 if (flags & CONNECT_VERBOSE)
 832                         fprintf(stderr, "%s ",
 833                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr));
 834                 break;
 835         }
 836
 837         if (sockfd < 0)
 838                 die(_("unable to connect to %s:\n%s"), host, error_message.buf);
 839
 840         enable_keepalive(sockfd);
 841
 842         if (flags & CONNECT_VERBOSE)
 843                 /* TRANSLATORS: this is the end of "Connecting to %s (port %s) ... " */
 844                 fprintf_ln(stderr, _("done."));
 845
 846         return sockfd;
 847 }
 848
 849 #endif /* NO_IPV6 */
 850
 851
 852 /*
 853  * Dummy child_process returned by git_connect() if the transport protocol
 854  * does not need fork(2).
 855  */
 856 static struct child_process no_fork = CHILD_PROCESS_INIT;
 857
 858 int git_connection_is_socket(struct child_process *conn)
 859 {
 860         return conn == &no_fork;
 861 }
 862
 863 static struct child_process *git_tcp_connect(int fd[2], char *host, int flags)
 864 {
 865         int sockfd = git_tcp_connect_sock(host, flags);
 866
 867         fd[0] = sockfd;
 868         fd[1] = dup(sockfd);
 869
 870         return &no_fork;
 871 }
 872
 873
 874 static char *git_proxy_command;
 875
 876 static int git_proxy_command_options(const char *var, const char *value,
 877                 void *cb)
 878 {
 879         if (!strcmp(var, "core.gitproxy")) {
 880                 const char *for_pos;
 881                 int matchlen = -1;
 882                 int hostlen;
 883                 const char *rhost_name = cb;
 884                 int rhost_len = strlen(rhost_name);
 885
 886                 if (git_proxy_command)
 887                         return 0;
 888                 if (!value)
 889                         return config_error_nonbool(var);
 890                 /* [core]
 891                  * ;# matches www.kernel.org as well
 892                  * gitproxy = netcatter-1 for kernel.org
 893                  * gitproxy = netcatter-2 for sample.xz
 894                  * gitproxy = netcatter-default
 895                  */
 896                 for_pos = strstr(value, " for ");
 897                 if (!for_pos)
 898                         /* matches everybody */
 899                         matchlen = strlen(value);
 900                 else {
 901                         hostlen = strlen(for_pos + 5);
 902                         if (rhost_len < hostlen)
 903                                 matchlen = -1;
 904                         else if (!strncmp(for_pos + 5,
 905                                           rhost_name + rhost_len - hostlen,
 906                                           hostlen) &&
 907                                  ((rhost_len == hostlen) ||
 908                                   rhost_name[rhost_len - hostlen -1] == '.'))
 909                                 matchlen = for_pos - value;
 910                         else
 911                                 matchlen = -1;
 912                 }
 913                 if (0 <= matchlen) {
 914                         /* core.gitproxy = none for kernel.org */
 915                         if (matchlen == 4 &&
 916                             !memcmp(value, "none", 4))
 917                                 matchlen = 0;
 918                         git_proxy_command = xmemdupz(value, matchlen);
 919                 }
 920                 return 0;
 921         }
 922
 923         return git_default_config(var, value, cb);
 924 }
 925
 926 static int git_use_proxy(const char *host)
 927 {
 928         git_proxy_command = getenv("GIT_PROXY_COMMAND");
 929         git_config(git_proxy_command_options, (void*)host);
 930         return (git_proxy_command && *git_proxy_command);
 931 }
 932
 933 static struct child_process *git_proxy_connect(int fd[2], char *host)
 934 {
 935         const char *port = STR(DEFAULT_GIT_PORT);
 936         struct child_process *proxy;
 937
 938         get_host_and_port(&host, &port);
 939
 940         if (looks_like_command_line_option(host))
 941                 die(_("strange hostname '%s' blocked"), host);
 942         if (looks_like_command_line_option(port))
 943                 die(_("strange port '%s' blocked"), port);
 944
 945         proxy = xmalloc(sizeof(*proxy));
 946         child_process_init(proxy);
 947         strvec_push(&proxy->args, git_proxy_command);
 948         strvec_push(&proxy->args, host);
 949         strvec_push(&proxy->args, port);
 950         proxy->in = -1;
 951         proxy->out = -1;
 952         if (start_command(proxy))
 953                 die(_("cannot start proxy %s"), git_proxy_command);
 954         fd[0] = proxy->out; /* read from proxy stdout */
 955         fd[1] = proxy->in;  /* write to proxy stdin */
 956         return proxy;
 957 }
 958
 959 static char *get_port(char *host)
 960 {
 961         char *end;
 962         char *p = strchr(host, ':');
 963
 964         if (p) {
 965                 long port = strtol(p + 1, &end, 10);
 966                 if (end != p + 1 && *end == '\0' && 0 <= port && port < 65536) {
 967                         *p = '\0';
 968                         return p+1;
 969                 }
 970         }
 971
 972         return NULL;
 973 }
 974
 975 /*
 976  * Extract protocol and relevant parts from the specified connection URL.
 977  * The caller must free() the returned strings.
 978  */
 979 static enum protocol parse_connect_url(const char *url_orig, char **ret_host,
 980                                        char **ret_path)
 981 {
 982         char *url;
 983         char *host, *path;
 984         char *end;
 985         int separator = '/';
 986         enum protocol protocol = PROTO_LOCAL;
 987
 988         if (is_url(url_orig))
 989                 url = url_decode(url_orig);
 990         else
 991                 url = xstrdup(url_orig);
 992
 993         host = strstr(url, "://");
 994         if (host) {
 995                 *host = '\0';
 996                 protocol = get_protocol(url);
 997                 host += 3;
 998         } else {
 999                 host = url;
1000                 if (!url_is_local_not_ssh(url)) {
1001                         protocol = PROTO_SSH;
1002                         separator = ':';
1003                 }
1004         }
1005
1006         /*
1007          * Don't do destructive transforms as protocol code does
1008          * '[]' unwrapping in get_host_and_port()
1009          */
1010         end = host_end(&host, 0);
1011
1012         if (protocol == PROTO_LOCAL)
1013                 path = end;
1014         else if (protocol == PROTO_FILE && *host != '/' &&
1015                  !has_dos_drive_prefix(host) &&
1016                  offset_1st_component(host - 2) > 1)
1017                 path = host - 2; /* include the leading "//" */
1018         else if (protocol == PROTO_FILE && has_dos_drive_prefix(end))
1019                 path = end; /* "file://$(pwd)" may be "file://C:/projects/repo" */
1020         else
1021                 path = strchr(end, separator);
1022
1023         if (!path || !*path)
1024                 die(_("no path specified; see 'git help pull' for valid url syntax"));
1025
1026         /*
1027          * null-terminate hostname and point path to ~ for URL's like this:
1028          *    ssh://host.xz/~user/repo
1029          */
1030
1031         end = path; /* Need to \0 terminate host here */
1032         if (separator == ':')
1033                 path++; /* path starts after ':' */
1034         if (protocol == PROTO_GIT || protocol == PROTO_SSH) {
1035                 if (path[1] == '~')
1036                         path++;
1037         }
1038
1039         path = xstrdup(path);
1040         *end = '\0';
1041
1042         *ret_host = xstrdup(host);
1043         *ret_path = path;
1044         free(url);
1045         return protocol;
1046 }
1047
1048 static const char *get_ssh_command(void)
1049 {
1050         const char *ssh;
1051
1052         if ((ssh = getenv("GIT_SSH_COMMAND")))
1053                 return ssh;
1054
1055         if (!git_config_get_string_tmp("core.sshcommand", &ssh))
1056                 return ssh;
1057
1058         return NULL;
1059 }
1060
1061 enum ssh_variant {
1062         VARIANT_AUTO,
1063         VARIANT_SIMPLE,
1064         VARIANT_SSH,
1065         VARIANT_PLINK,
1066         VARIANT_PUTTY,
1067         VARIANT_TORTOISEPLINK,
1068 };
1069
1070 static void override_ssh_variant(enum ssh_variant *ssh_variant)
1071 {
1072         const char *variant = getenv("GIT_SSH_VARIANT");
1073
1074         if (!variant && git_config_get_string_tmp("ssh.variant", &variant))
1075                 return;
1076
1077         if (!strcmp(variant, "auto"))
1078                 *ssh_variant = VARIANT_AUTO;
1079         else if (!strcmp(variant, "plink"))
1080                 *ssh_variant = VARIANT_PLINK;
1081         else if (!strcmp(variant, "putty"))
1082                 *ssh_variant = VARIANT_PUTTY;
1083         else if (!strcmp(variant, "tortoiseplink"))
1084                 *ssh_variant = VARIANT_TORTOISEPLINK;
1085         else if (!strcmp(variant, "simple"))
1086                 *ssh_variant = VARIANT_SIMPLE;
1087         else
1088                 *ssh_variant = VARIANT_SSH;
1089 }
1090
1091 static enum ssh_variant determine_ssh_variant(const char *ssh_command,
1092                                               int is_cmdline)
1093 {
1094         enum ssh_variant ssh_variant = VARIANT_AUTO;
1095         const char *variant;
1096         char *p = NULL;
1097
1098         override_ssh_variant(&ssh_variant);
1099
1100         if (ssh_variant != VARIANT_AUTO)
1101                 return ssh_variant;
1102
1103         if (!is_cmdline) {
1104                 p = xstrdup(ssh_command);
1105                 variant = basename(p);
1106         } else {
1107                 const char **ssh_argv;
1108
1109                 p = xstrdup(ssh_command);
1110                 if (split_cmdline(p, &ssh_argv) > 0) {
1111                         variant = basename((char *)ssh_argv[0]);
1112                         /*
1113                          * At this point, variant points into the buffer
1114                          * referenced by p, hence we do not need ssh_argv
1115                          * any longer.
1116                          */
1117                         free(ssh_argv);
1118                 } else {
1119                         free(p);
1120                         return ssh_variant;
1121                 }
1122         }
1123
1124         if (!strcasecmp(variant, "ssh") ||
1125             !strcasecmp(variant, "ssh.exe"))
1126                 ssh_variant = VARIANT_SSH;
1127         else if (!strcasecmp(variant, "plink") ||
1128                  !strcasecmp(variant, "plink.exe"))
1129                 ssh_variant = VARIANT_PLINK;
1130         else if (!strcasecmp(variant, "tortoiseplink") ||
1131                  !strcasecmp(variant, "tortoiseplink.exe"))
1132                 ssh_variant = VARIANT_TORTOISEPLINK;
1133
1134         free(p);
1135         return ssh_variant;
1136 }
1137
1138 /*
1139  * Open a connection using Git's native protocol.
1140  *
1141  * The caller is responsible for freeing hostandport, but this function may
1142  * modify it (for example, to truncate it to remove the port part).
1143  */
1144 static struct child_process *git_connect_git(int fd[2], char *hostandport,
1145                                              const char *path, const char *prog,
1146                                              enum protocol_version version,
1147                                              int flags)
1148 {
1149         struct child_process *conn;
1150         struct strbuf request = STRBUF_INIT;
1151         /*
1152          * Set up virtual host information based on where we will
1153          * connect, unless the user has overridden us in
1154          * the environment.
1155          */
1156         char *target_host = getenv("GIT_OVERRIDE_VIRTUAL_HOST");
1157         if (target_host)
1158                 target_host = xstrdup(target_host);
1159         else
1160                 target_host = xstrdup(hostandport);
1161
1162         transport_check_allowed("git");
1163         if (strchr(target_host, '\n') || strchr(path, '\n'))
1164                 die(_("newline is forbidden in git:// hosts and repo paths"));
1165
1166         /*
1167          * These underlying connection commands die() if they
1168          * cannot connect.
1169          */
1170         if (git_use_proxy(hostandport))
1171                 conn = git_proxy_connect(fd, hostandport);
1172         else
1173                 conn = git_tcp_connect(fd, hostandport, flags);
1174         /*
1175          * Separate original protocol components prog and path
1176          * from extended host header with a NUL byte.
1177          *
1178          * Note: Do not add any other headers here!  Doing so
1179          * will cause older git-daemon servers to crash.
1180          */
1181         strbuf_addf(&request,
1182                     "%s %s%chost=%s%c",
1183                     prog, path, 0,
1184                     target_host, 0);
1185
1186         /* If using a new version put that stuff here after a second null byte */
1187         if (version > 0) {
1188                 strbuf_addch(&request, '\0');
1189                 strbuf_addf(&request, "version=%d%c",
1190                             version, '\0');
1191         }
1192
1193         packet_write(fd[1], request.buf, request.len);
1194
1195         free(target_host);
1196         strbuf_release(&request);
1197         return conn;
1198 }
1199
1200 /*
1201  * Append the appropriate environment variables to `env` and options to
1202  * `args` for running ssh in Git's SSH-tunneled transport.
1203  */
1204 static void push_ssh_options(struct strvec *args, struct strvec *env,
1205                              enum ssh_variant variant, const char *port,
1206                              enum protocol_version version, int flags)
1207 {
1208         if (variant == VARIANT_SSH &&
1209             version > 0) {
1210                 strvec_push(args, "-o");
1211                 strvec_push(args, "SendEnv=" GIT_PROTOCOL_ENVIRONMENT);
1212                 strvec_pushf(env, GIT_PROTOCOL_ENVIRONMENT "=version=%d",
1213                              version);
1214         }
1215
1216         if (flags & CONNECT_IPV4) {
1217                 switch (variant) {
1218                 case VARIANT_AUTO:
1219                         BUG("VARIANT_AUTO passed to push_ssh_options");
1220                 case VARIANT_SIMPLE:
1221                         die(_("ssh variant 'simple' does not support -4"));
1222                 case VARIANT_SSH:
1223                 case VARIANT_PLINK:
1224                 case VARIANT_PUTTY:
1225                 case VARIANT_TORTOISEPLINK:
1226                         strvec_push(args, "-4");
1227                 }
1228         } else if (flags & CONNECT_IPV6) {
1229                 switch (variant) {
1230                 case VARIANT_AUTO:
1231                         BUG("VARIANT_AUTO passed to push_ssh_options");
1232                 case VARIANT_SIMPLE:
1233                         die(_("ssh variant 'simple' does not support -6"));
1234                 case VARIANT_SSH:
1235                 case VARIANT_PLINK:
1236                 case VARIANT_PUTTY:
1237                 case VARIANT_TORTOISEPLINK:
1238                         strvec_push(args, "-6");
1239                 }
1240         }
1241
1242         if (variant == VARIANT_TORTOISEPLINK)
1243                 strvec_push(args, "-batch");
1244
1245         if (port) {
1246                 switch (variant) {
1247                 case VARIANT_AUTO:
1248                         BUG("VARIANT_AUTO passed to push_ssh_options");
1249                 case VARIANT_SIMPLE:
1250                         die(_("ssh variant 'simple' does not support setting port"));
1251                 case VARIANT_SSH:
1252                         strvec_push(args, "-p");
1253                         break;
1254                 case VARIANT_PLINK:
1255                 case VARIANT_PUTTY:
1256                 case VARIANT_TORTOISEPLINK:
1257                         strvec_push(args, "-P");
1258                 }
1259
1260                 strvec_push(args, port);
1261         }
1262 }
1263
1264 /* Prepare a child_process for use by Git's SSH-tunneled transport. */
1265 static void fill_ssh_args(struct child_process *conn, const char *ssh_host,
1266                           const char *port, enum protocol_version version,
1267                           int flags)
1268 {
1269         const char *ssh;
1270         enum ssh_variant variant;
1271
1272         if (looks_like_command_line_option(ssh_host))
1273                 die(_("strange hostname '%s' blocked"), ssh_host);
1274
1275         ssh = get_ssh_command();
1276         if (ssh) {
1277                 variant = determine_ssh_variant(ssh, 1);
1278         } else {
1279                 /*
1280                  * GIT_SSH is the no-shell version of
1281                  * GIT_SSH_COMMAND (and must remain so for
1282                  * historical compatibility).
1283                  */
1284                 conn->use_shell = 0;
1285
1286                 ssh = getenv("GIT_SSH");
1287                 if (!ssh)
1288                         ssh = "ssh";
1289                 variant = determine_ssh_variant(ssh, 0);
1290         }
1291
1292         if (variant == VARIANT_AUTO) {
1293                 struct child_process detect = CHILD_PROCESS_INIT;
1294
1295                 detect.use_shell = conn->use_shell;
1296                 detect.no_stdin = detect.no_stdout = detect.no_stderr = 1;
1297
1298                 strvec_push(&detect.args, ssh);
1299                 strvec_push(&detect.args, "-G");
1300                 push_ssh_options(&detect.args, &detect.env_array,
1301                                  VARIANT_SSH, port, version, flags);
1302                 strvec_push(&detect.args, ssh_host);
1303
1304                 variant = run_command(&detect) ? VARIANT_SIMPLE : VARIANT_SSH;
1305         }
1306
1307         strvec_push(&conn->args, ssh);
1308         push_ssh_options(&conn->args, &conn->env_array, variant, port, version, flags);
1309         strvec_push(&conn->args, ssh_host);
1310 }
1311
1312 /*
1313  * This returns the dummy child_process `no_fork` if the transport protocol
1314  * does not need fork(2), or a struct child_process object if it does.  Once
1315  * done, finish the connection with finish_connect() with the value returned
1316  * from this function (it is safe to call finish_connect() with NULL to
1317  * support the former case).
1318  *
1319  * If it returns, the connect is successful; it just dies on errors (this
1320  * will hopefully be changed in a libification effort, to return NULL when
1321  * the connection failed).
1322  */
1323 struct child_process *git_connect(int fd[2], const char *url,
1324                                   const char *prog, int flags)
1325 {
1326         char *hostandport, *path;
1327         struct child_process *conn;
1328         enum protocol protocol;
1329         enum protocol_version version = get_protocol_version_config();
1330
1331         /*
1332          * NEEDSWORK: If we are trying to use protocol v2 and we are planning
1333          * to perform a push, then fallback to v0 since the client doesn't know
1334          * how to push yet using v2.
1335          */
1336         if (version == protocol_v2 && !strcmp("git-receive-pack", prog))
1337                 version = protocol_v0;
1338
1339         /* Without this we cannot rely on waitpid() to tell
1340          * what happened to our children.
1341          */
1342         signal(SIGCHLD, SIG_DFL);
1343
1344         protocol = parse_connect_url(url, &hostandport, &path);
1345         if ((flags & CONNECT_DIAG_URL) && (protocol != PROTO_SSH)) {
1346                 printf("Diag: url=%s\n", url ? url : "NULL");
1347                 printf("Diag: protocol=%s\n", prot_name(protocol));
1348                 printf("Diag: hostandport=%s\n", hostandport ? hostandport : "NULL");
1349                 printf("Diag: path=%s\n", path ? path : "NULL");
1350                 conn = NULL;
1351         } else if (protocol == PROTO_GIT) {
1352                 conn = git_connect_git(fd, hostandport, path, prog, version, flags);
1353                 conn->trace2_child_class = "transport/git";
1354         } else {
1355                 struct strbuf cmd = STRBUF_INIT;
1356                 const char *const *var;
1357
1358                 conn = xmalloc(sizeof(*conn));
1359                 child_process_init(conn);
1360
1361                 if (looks_like_command_line_option(path))
1362                         die(_("strange pathname '%s' blocked"), path);
1363
1364                 strbuf_addstr(&cmd, prog);
1365                 strbuf_addch(&cmd, ' ');
1366                 sq_quote_buf(&cmd, path);
1367
1368                 /* remove repo-local variables from the environment */
1369                 for (var = local_repo_env; *var; var++)
1370                         strvec_push(&conn->env_array, *var);
1371
1372                 conn->use_shell = 1;
1373                 conn->in = conn->out = -1;
1374                 if (protocol == PROTO_SSH) {
1375                         char *ssh_host = hostandport;
1376                         const char *port = NULL;
1377                         transport_check_allowed("ssh");
1378                         get_host_and_port(&ssh_host, &port);
1379
1380                         if (!port)
1381                                 port = get_port(ssh_host);
1382
1383                         if (flags & CONNECT_DIAG_URL) {
1384                                 printf("Diag: url=%s\n", url ? url : "NULL");
1385                                 printf("Diag: protocol=%s\n", prot_name(protocol));
1386                                 printf("Diag: userandhost=%s\n", ssh_host ? ssh_host : "NULL");
1387                                 printf("Diag: port=%s\n", port ? port : "NONE");
1388                                 printf("Diag: path=%s\n", path ? path : "NULL");
1389
1390                                 free(hostandport);
1391                                 free(path);
1392                                 free(conn);
1393                                 strbuf_release(&cmd);
1394                                 return NULL;
1395                         }
1396                         conn->trace2_child_class = "transport/ssh";
1397                         fill_ssh_args(conn, ssh_host, port, version, flags);
1398                 } else {
1399                         transport_check_allowed("file");
1400                         conn->trace2_child_class = "transport/file";
1401                         if (version > 0) {
1402                                 strvec_pushf(&conn->env_array,
1403                                              GIT_PROTOCOL_ENVIRONMENT "=version=%d",
1404                                              version);
1405                         }
1406                 }
1407                 strvec_push(&conn->args, cmd.buf);
1408
1409                 if (start_command(conn))
1410                         die(_("unable to fork"));
1411
1412                 fd[0] = conn->out; /* read from child's stdout */
1413                 fd[1] = conn->in;  /* write to child's stdin */
1414                 strbuf_release(&cmd);
1415         }
1416         free(hostandport);
1417         free(path);
1418         return conn;
1419 }
1420
1421 int finish_connect(struct child_process *conn)
1422 {
1423         int code;
1424         if (!conn || git_connection_is_socket(conn))
1425                 return 0;
1426
1427         code = finish_command(conn);
1428         free(conn);
1429         return code;
1430 }