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         trace2_data_intmax("transfer", NULL, "negotiated-version", version);
 168
 169         return version;
 170 }
 171
 172 static void parse_one_symref_info(struct string_list *symref, const char *val, int len)
 173 {
 174         char *sym, *target;
 175         struct string_list_item *item;
 176
 177         if (!len)
 178                 return; /* just "symref" */
 179         /* e.g. "symref=HEAD:refs/heads/master" */
 180         sym = xmemdupz(val, len);
 181         target = strchr(sym, ':');
 182         if (!target)
 183                 /* just "symref=something" */
 184                 goto reject;
 185         *(target++) = '\0';
 186         if (check_refname_format(sym, REFNAME_ALLOW_ONELEVEL) ||
 187             check_refname_format(target, REFNAME_ALLOW_ONELEVEL))
 188                 /* "symref=bogus:pair */
 189                 goto reject;
 190         item = string_list_append_nodup(symref, sym);
 191         item->util = target;
 192         return;
 193 reject:
 194         free(sym);
 195         return;
 196 }
 197
 198 static void annotate_refs_with_symref_info(struct ref *ref)
 199 {
 200         struct string_list symref = STRING_LIST_INIT_DUP;
 201         int offset = 0;
 202
 203         while (1) {
 204                 int len;
 205                 const char *val;
 206
 207                 val = next_server_feature_value("symref", &len, &offset);
 208                 if (!val)
 209                         break;
 210                 parse_one_symref_info(&symref, val, len);
 211         }
 212         string_list_sort(&symref);
 213
 214         for (; ref; ref = ref->next) {
 215                 struct string_list_item *item;
 216                 item = string_list_lookup(&symref, ref->name);
 217                 if (!item)
 218                         continue;
 219                 ref->symref = xstrdup((char *)item->util);
 220         }
 221         string_list_clear(&symref, 0);
 222 }
 223
 224 static void process_capabilities(struct packet_reader *reader, int *linelen)
 225 {
 226         const char *feat_val;
 227         int feat_len;
 228         const char *line = reader->line;
 229         int nul_location = strlen(line);
 230         if (nul_location == *linelen)
 231                 return;
 232         server_capabilities_v1 = xstrdup(line + nul_location + 1);
 233         *linelen = nul_location;
 234
 235         feat_val = server_feature_value("object-format", &feat_len);
 236         if (feat_val) {
 237                 char *hash_name = xstrndup(feat_val, feat_len);
 238                 int hash_algo = hash_algo_by_name(hash_name);
 239                 if (hash_algo != GIT_HASH_UNKNOWN)
 240                         reader->hash_algo = &hash_algos[hash_algo];
 241                 free(hash_name);
 242         } else {
 243                 reader->hash_algo = &hash_algos[GIT_HASH_SHA1];
 244         }
 245 }
 246
 247 static int process_dummy_ref(const struct packet_reader *reader)
 248 {
 249         const char *line = reader->line;
 250         struct object_id oid;
 251         const char *name;
 252
 253         if (parse_oid_hex_algop(line, &oid, &name, reader->hash_algo))
 254                 return 0;
 255         if (*name != ' ')
 256                 return 0;
 257         name++;
 258
 259         return oideq(null_oid(), &oid) && !strcmp(name, "capabilities^{}");
 260 }
 261
 262 static void check_no_capabilities(const char *line, int len)
 263 {
 264         if (strlen(line) != len)
 265                 warning(_("ignoring capabilities after first line '%s'"),
 266                         line + strlen(line));
 267 }
 268
 269 static int process_ref(const struct packet_reader *reader, int len,
 270                        struct ref ***list, unsigned int flags,
 271                        struct oid_array *extra_have)
 272 {
 273         const char *line = reader->line;
 274         struct object_id old_oid;
 275         const char *name;
 276
 277         if (parse_oid_hex_algop(line, &old_oid, &name, reader->hash_algo))
 278                 return 0;
 279         if (*name != ' ')
 280                 return 0;
 281         name++;
 282
 283         if (extra_have && !strcmp(name, ".have")) {
 284                 oid_array_append(extra_have, &old_oid);
 285         } else if (!strcmp(name, "capabilities^{}")) {
 286                 die(_("protocol error: unexpected capabilities^{}"));
 287         } else if (check_ref(name, flags)) {
 288                 struct ref *ref = alloc_ref(name);
 289                 oidcpy(&ref->old_oid, &old_oid);
 290                 **list = ref;
 291                 *list = &ref->next;
 292         }
 293         check_no_capabilities(line, len);
 294         return 1;
 295 }
 296
 297 static int process_shallow(const struct packet_reader *reader, int len,
 298                            struct oid_array *shallow_points)
 299 {
 300         const char *line = reader->line;
 301         const char *arg;
 302         struct object_id old_oid;
 303
 304         if (!skip_prefix(line, "shallow ", &arg))
 305                 return 0;
 306
 307         if (get_oid_hex_algop(arg, &old_oid, reader->hash_algo))
 308                 die(_("protocol error: expected shallow sha-1, got '%s'"), arg);
 309         if (!shallow_points)
 310                 die(_("repository on the other end cannot be shallow"));
 311         oid_array_append(shallow_points, &old_oid);
 312         check_no_capabilities(line, len);
 313         return 1;
 314 }
 315
 316 enum get_remote_heads_state {
 317         EXPECTING_FIRST_REF = 0,
 318         EXPECTING_REF,
 319         EXPECTING_SHALLOW,
 320         EXPECTING_DONE,
 321 };
 322
 323 /*
 324  * Read all the refs from the other end
 325  */
 326 struct ref **get_remote_heads(struct packet_reader *reader,
 327                               struct ref **list, unsigned int flags,
 328                               struct oid_array *extra_have,
 329                               struct oid_array *shallow_points)
 330 {
 331         struct ref **orig_list = list;
 332         int len = 0;
 333         enum get_remote_heads_state state = EXPECTING_FIRST_REF;
 334
 335         *list = NULL;
 336
 337         while (state != EXPECTING_DONE) {
 338                 switch (packet_reader_read(reader)) {
 339                 case PACKET_READ_EOF:
 340                         die_initial_contact(1);
 341                 case PACKET_READ_NORMAL:
 342                         len = reader->pktlen;
 343                         break;
 344                 case PACKET_READ_FLUSH:
 345                         state = EXPECTING_DONE;
 346                         break;
 347                 case PACKET_READ_DELIM:
 348                 case PACKET_READ_RESPONSE_END:
 349                         die(_("invalid packet"));
 350                 }
 351
 352                 switch (state) {
 353                 case EXPECTING_FIRST_REF:
 354                         process_capabilities(reader, &len);
 355                         if (process_dummy_ref(reader)) {
 356                                 state = EXPECTING_SHALLOW;
 357                                 break;
 358                         }
 359                         state = EXPECTING_REF;
 360                         /* fallthrough */
 361                 case EXPECTING_REF:
 362                         if (process_ref(reader, len, &list, flags, extra_have))
 363                                 break;
 364                         state = EXPECTING_SHALLOW;
 365                         /* fallthrough */
 366                 case EXPECTING_SHALLOW:
 367                         if (process_shallow(reader, len, shallow_points))
 368                                 break;
 369                         die(_("protocol error: unexpected '%s'"), reader->line);
 370                 case EXPECTING_DONE:
 371                         break;
 372                 }
 373         }
 374
 375         annotate_refs_with_symref_info(*orig_list);
 376
 377         return list;
 378 }
 379
 380 /* Returns 1 when a valid ref has been added to `list`, 0 otherwise */
 381 static int process_ref_v2(struct packet_reader *reader, struct ref ***list,
 382                           char **unborn_head_target)
 383 {
 384         int ret = 1;
 385         int i = 0;
 386         struct object_id old_oid;
 387         struct ref *ref;
 388         struct string_list line_sections = STRING_LIST_INIT_DUP;
 389         const char *end;
 390         const char *line = reader->line;
 391
 392         /*
 393          * Ref lines have a number of fields which are space deliminated.  The
 394          * first field is the OID of the ref.  The second field is the ref
 395          * name.  Subsequent fields (symref-target and peeled) are optional and
 396          * don't have a particular order.
 397          */
 398         if (string_list_split(&line_sections, line, ' ', -1) < 2) {
 399                 ret = 0;
 400                 goto out;
 401         }
 402
 403         if (!strcmp("unborn", line_sections.items[i].string)) {
 404                 i++;
 405                 if (unborn_head_target &&
 406                     !strcmp("HEAD", line_sections.items[i++].string)) {
 407                         /*
 408                          * Look for the symref target (if any). If found,
 409                          * return it to the caller.
 410                          */
 411                         for (; i < line_sections.nr; i++) {
 412                                 const char *arg = line_sections.items[i].string;
 413
 414                                 if (skip_prefix(arg, "symref-target:", &arg)) {
 415                                         *unborn_head_target = xstrdup(arg);
 416                                         break;
 417                                 }
 418                         }
 419                 }
 420                 goto out;
 421         }
 422         if (parse_oid_hex_algop(line_sections.items[i++].string, &old_oid, &end, reader->hash_algo) ||
 423             *end) {
 424                 ret = 0;
 425                 goto out;
 426         }
 427
 428         ref = alloc_ref(line_sections.items[i++].string);
 429
 430         memcpy(ref->old_oid.hash, old_oid.hash, reader->hash_algo->rawsz);
 431         **list = ref;
 432         *list = &ref->next;
 433
 434         for (; i < line_sections.nr; i++) {
 435                 const char *arg = line_sections.items[i].string;
 436                 if (skip_prefix(arg, "symref-target:", &arg))
 437                         ref->symref = xstrdup(arg);
 438
 439                 if (skip_prefix(arg, "peeled:", &arg)) {
 440                         struct object_id peeled_oid;
 441                         char *peeled_name;
 442                         struct ref *peeled;
 443                         if (parse_oid_hex_algop(arg, &peeled_oid, &end,
 444                                                 reader->hash_algo) || *end) {
 445                                 ret = 0;
 446                                 goto out;
 447                         }
 448
 449                         peeled_name = xstrfmt("%s^{}", ref->name);
 450                         peeled = alloc_ref(peeled_name);
 451
 452                         memcpy(peeled->old_oid.hash, peeled_oid.hash,
 453                                reader->hash_algo->rawsz);
 454                         **list = peeled;
 455                         *list = &peeled->next;
 456
 457                         free(peeled_name);
 458                 }
 459         }
 460
 461 out:
 462         string_list_clear(&line_sections, 0);
 463         return ret;
 464 }
 465
 466 void check_stateless_delimiter(int stateless_rpc,
 467                               struct packet_reader *reader,
 468                               const char *error)
 469 {
 470         if (!stateless_rpc)
 471                 return; /* not in stateless mode, no delimiter expected */
 472         if (packet_reader_read(reader) != PACKET_READ_RESPONSE_END)
 473                 die("%s", error);
 474 }
 475
 476 struct ref **get_remote_refs(int fd_out, struct packet_reader *reader,
 477                              struct ref **list, int for_push,
 478                              struct transport_ls_refs_options *transport_options,
 479                              const struct string_list *server_options,
 480                              int stateless_rpc)
 481 {
 482         int i;
 483         const char *hash_name;
 484         struct strvec *ref_prefixes = transport_options ?
 485                 &transport_options->ref_prefixes : NULL;
 486         char **unborn_head_target = transport_options ?
 487                 &transport_options->unborn_head_target : NULL;
 488         *list = NULL;
 489
 490         if (server_supports_v2("ls-refs", 1))
 491                 packet_write_fmt(fd_out, "command=ls-refs\n");
 492
 493         if (server_supports_v2("agent", 0))
 494                 packet_write_fmt(fd_out, "agent=%s", git_user_agent_sanitized());
 495
 496         if (server_feature_v2("object-format", &hash_name)) {
 497                 int hash_algo = hash_algo_by_name(hash_name);
 498                 if (hash_algo == GIT_HASH_UNKNOWN)
 499                         die(_("unknown object format '%s' specified by server"), hash_name);
 500                 reader->hash_algo = &hash_algos[hash_algo];
 501                 packet_write_fmt(fd_out, "object-format=%s", reader->hash_algo->name);
 502         } else {
 503                 reader->hash_algo = &hash_algos[GIT_HASH_SHA1];
 504         }
 505
 506         if (server_options && server_options->nr &&
 507             server_supports_v2("server-option", 1))
 508                 for (i = 0; i < server_options->nr; i++)
 509                         packet_write_fmt(fd_out, "server-option=%s",
 510                                          server_options->items[i].string);
 511
 512         packet_delim(fd_out);
 513         /* When pushing we don't want to request the peeled tags */
 514         if (!for_push)
 515                 packet_write_fmt(fd_out, "peel\n");
 516         packet_write_fmt(fd_out, "symrefs\n");
 517         if (server_supports_feature("ls-refs", "unborn", 0))
 518                 packet_write_fmt(fd_out, "unborn\n");
 519         for (i = 0; ref_prefixes && i < ref_prefixes->nr; i++) {
 520                 packet_write_fmt(fd_out, "ref-prefix %s\n",
 521                                  ref_prefixes->v[i]);
 522         }
 523         packet_flush(fd_out);
 524
 525         /* Process response from server */
 526         while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
 527                 if (!process_ref_v2(reader, &list, unborn_head_target))
 528                         die(_("invalid ls-refs response: %s"), reader->line);
 529         }
 530
 531         if (reader->status != PACKET_READ_FLUSH)
 532                 die(_("expected flush after ref listing"));
 533
 534         check_stateless_delimiter(stateless_rpc, reader,
 535                                   _("expected response end packet after ref listing"));
 536
 537         return list;
 538 }
 539
 540 const char *parse_feature_value(const char *feature_list, const char *feature, int *lenp, int *offset)
 541 {
 542         int len;
 543
 544         if (!feature_list)
 545                 return NULL;
 546
 547         len = strlen(feature);
 548         if (offset)
 549                 feature_list += *offset;
 550         while (*feature_list) {
 551                 const char *found = strstr(feature_list, feature);
 552                 if (!found)
 553                         return NULL;
 554                 if (feature_list == found || isspace(found[-1])) {
 555                         const char *value = found + len;
 556                         /* feature with no value (e.g., "thin-pack") */
 557                         if (!*value || isspace(*value)) {
 558                                 if (lenp)
 559                                         *lenp = 0;
 560                                 return value;
 561                         }
 562                         /* feature with a value (e.g., "agent=git/1.2.3") */
 563                         else if (*value == '=') {
 564                                 int end;
 565
 566                                 value++;
 567                                 end = strcspn(value, " \t\n");
 568                                 if (lenp)
 569                                         *lenp = end;
 570                                 if (offset)
 571                                         *offset = value + end - feature_list;
 572                                 return value;
 573                         }
 574                         /*
 575                          * otherwise we matched a substring of another feature;
 576                          * keep looking
 577                          */
 578                 }
 579                 feature_list = found + 1;
 580         }
 581         return NULL;
 582 }
 583
 584 int server_supports_hash(const char *desired, int *feature_supported)
 585 {
 586         int offset = 0;
 587         int len;
 588         const char *hash;
 589
 590         hash = next_server_feature_value("object-format", &len, &offset);
 591         if (feature_supported)
 592                 *feature_supported = !!hash;
 593         if (!hash) {
 594                 hash = hash_algos[GIT_HASH_SHA1].name;
 595                 len = strlen(hash);
 596         }
 597         while (hash) {
 598                 if (!xstrncmpz(desired, hash, len))
 599                         return 1;
 600
 601                 hash = next_server_feature_value("object-format", &len, &offset);
 602         }
 603         return 0;
 604 }
 605
 606 int parse_feature_request(const char *feature_list, const char *feature)
 607 {
 608         return !!parse_feature_value(feature_list, feature, NULL, NULL);
 609 }
 610
 611 static const char *next_server_feature_value(const char *feature, int *len, int *offset)
 612 {
 613         return parse_feature_value(server_capabilities_v1, feature, len, offset);
 614 }
 615
 616 const char *server_feature_value(const char *feature, int *len)
 617 {
 618         return parse_feature_value(server_capabilities_v1, feature, len, NULL);
 619 }
 620
 621 int server_supports(const char *feature)
 622 {
 623         return !!server_feature_value(feature, NULL);
 624 }
 625
 626 enum protocol {
 627         PROTO_LOCAL = 1,
 628         PROTO_FILE,
 629         PROTO_SSH,
 630         PROTO_GIT
 631 };
 632
 633 int url_is_local_not_ssh(const char *url)
 634 {
 635         const char *colon = strchr(url, ':');
 636         const char *slash = strchr(url, '/');
 637         return !colon || (slash && slash < colon) ||
 638                 (has_dos_drive_prefix(url) && is_valid_path(url));
 639 }
 640
 641 static const char *prot_name(enum protocol protocol)
 642 {
 643         switch (protocol) {
 644                 case PROTO_LOCAL:
 645                 case PROTO_FILE:
 646                         return "file";
 647                 case PROTO_SSH:
 648                         return "ssh";
 649                 case PROTO_GIT:
 650                         return "git";
 651                 default:
 652                         return "unknown protocol";
 653         }
 654 }
 655
 656 static enum protocol get_protocol(const char *name)
 657 {
 658         if (!strcmp(name, "ssh"))
 659                 return PROTO_SSH;
 660         if (!strcmp(name, "git"))
 661                 return PROTO_GIT;
 662         if (!strcmp(name, "git+ssh")) /* deprecated - do not use */
 663                 return PROTO_SSH;
 664         if (!strcmp(name, "ssh+git")) /* deprecated - do not use */
 665                 return PROTO_SSH;
 666         if (!strcmp(name, "file"))
 667                 return PROTO_FILE;
 668         die(_("protocol '%s' is not supported"), name);
 669 }
 670
 671 static char *host_end(char **hoststart, int removebrackets)
 672 {
 673         char *host = *hoststart;
 674         char *end;
 675         char *start = strstr(host, "@[");
 676         if (start)
 677                 start++; /* Jump over '@' */
 678         else
 679                 start = host;
 680         if (start[0] == '[') {
 681                 end = strchr(start + 1, ']');
 682                 if (end) {
 683                         if (removebrackets) {
 684                                 *end = 0;
 685                                 memmove(start, start + 1, end - start);
 686                                 end++;
 687                         }
 688                 } else
 689                         end = host;
 690         } else
 691                 end = host;
 692         return end;
 693 }
 694
 695 #define STR_(s) # s
 696 #define STR(s)  STR_(s)
 697
 698 static void get_host_and_port(char **host, const char **port)
 699 {
 700         char *colon, *end;
 701         end = host_end(host, 1);
 702         colon = strchr(end, ':');
 703         if (colon) {
 704                 long portnr = strtol(colon + 1, &end, 10);
 705                 if (end != colon + 1 && *end == '\0' && 0 <= portnr && portnr < 65536) {
 706                         *colon = 0;
 707                         *port = colon + 1;
 708                 } else if (!colon[1]) {
 709                         *colon = 0;
 710                 }
 711         }
 712 }
 713
 714 static void enable_keepalive(int sockfd)
 715 {
 716         int ka = 1;
 717
 718         if (setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, &ka, sizeof(ka)) < 0)
 719                 error_errno(_("unable to set SO_KEEPALIVE on socket"));
 720 }
 721
 722 #ifndef NO_IPV6
 723
 724 static const char *ai_name(const struct addrinfo *ai)
 725 {
 726         static char addr[NI_MAXHOST];
 727         if (getnameinfo(ai->ai_addr, ai->ai_addrlen, addr, sizeof(addr), NULL, 0,
 728                         NI_NUMERICHOST) != 0)
 729                 xsnprintf(addr, sizeof(addr), "(unknown)");
 730
 731         return addr;
 732 }
 733
 734 /*
 735  * Returns a connected socket() fd, or else die()s.
 736  */
 737 static int git_tcp_connect_sock(char *host, int flags)
 738 {
 739         struct strbuf error_message = STRBUF_INIT;
 740         int sockfd = -1;
 741         const char *port = STR(DEFAULT_GIT_PORT);
 742         struct addrinfo hints, *ai0, *ai;
 743         int gai;
 744         int cnt = 0;
 745
 746         get_host_and_port(&host, &port);
 747         if (!*port)
 748                 port = "<none>";
 749
 750         memset(&hints, 0, sizeof(hints));
 751         if (flags & CONNECT_IPV4)
 752                 hints.ai_family = AF_INET;
 753         else if (flags & CONNECT_IPV6)
 754                 hints.ai_family = AF_INET6;
 755         hints.ai_socktype = SOCK_STREAM;
 756         hints.ai_protocol = IPPROTO_TCP;
 757
 758         if (flags & CONNECT_VERBOSE)
 759                 fprintf(stderr, _("Looking up %s ... "), host);
 760
 761         gai = getaddrinfo(host, port, &hints, &ai);
 762         if (gai)
 763                 die(_("unable to look up %s (port %s) (%s)"), host, port, gai_strerror(gai));
 764
 765         if (flags & CONNECT_VERBOSE)
 766                 /* TRANSLATORS: this is the end of "Looking up %s ... " */
 767                 fprintf(stderr, _("done.\nConnecting to %s (port %s) ... "), host, port);
 768
 769         for (ai0 = ai; ai; ai = ai->ai_next, cnt++) {
 770                 sockfd = socket(ai->ai_family,
 771                                 ai->ai_socktype, ai->ai_protocol);
 772                 if ((sockfd < 0) ||
 773                     (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0)) {
 774                         strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 775                                     host, cnt, ai_name(ai), strerror(errno));
 776                         if (0 <= sockfd)
 777                                 close(sockfd);
 778                         sockfd = -1;
 779                         continue;
 780                 }
 781                 if (flags & CONNECT_VERBOSE)
 782                         fprintf(stderr, "%s ", ai_name(ai));
 783                 break;
 784         }
 785
 786         freeaddrinfo(ai0);
 787
 788         if (sockfd < 0)
 789                 die(_("unable to connect to %s:\n%s"), host, error_message.buf);
 790
 791         enable_keepalive(sockfd);
 792
 793         if (flags & CONNECT_VERBOSE)
 794                 /* TRANSLATORS: this is the end of "Connecting to %s (port %s) ... " */
 795                 fprintf_ln(stderr, _("done."));
 796
 797         strbuf_release(&error_message);
 798
 799         return sockfd;
 800 }
 801
 802 #else /* NO_IPV6 */
 803
 804 /*
 805  * Returns a connected socket() fd, or else die()s.
 806  */
 807 static int git_tcp_connect_sock(char *host, int flags)
 808 {
 809         struct strbuf error_message = STRBUF_INIT;
 810         int sockfd = -1;
 811         const char *port = STR(DEFAULT_GIT_PORT);
 812         char *ep;
 813         struct hostent *he;
 814         struct sockaddr_in sa;
 815         char **ap;
 816         unsigned int nport;
 817         int cnt;
 818
 819         get_host_and_port(&host, &port);
 820
 821         if (flags & CONNECT_VERBOSE)
 822                 fprintf(stderr, _("Looking up %s ... "), host);
 823
 824         he = gethostbyname(host);
 825         if (!he)
 826                 die(_("unable to look up %s (%s)"), host, hstrerror(h_errno));
 827         nport = strtoul(port, &ep, 10);
 828         if ( ep == port || *ep ) {
 829                 /* Not numeric */
 830                 struct servent *se = getservbyname(port,"tcp");
 831                 if ( !se )
 832                         die(_("unknown port %s"), port);
 833                 nport = se->s_port;
 834         }
 835
 836         if (flags & CONNECT_VERBOSE)
 837                 /* TRANSLATORS: this is the end of "Looking up %s ... " */
 838                 fprintf(stderr, _("done.\nConnecting to %s (port %s) ... "), host, port);
 839
 840         for (cnt = 0, ap = he->h_addr_list; *ap; ap++, cnt++) {
 841                 memset(&sa, 0, sizeof sa);
 842                 sa.sin_family = he->h_addrtype;
 843                 sa.sin_port = htons(nport);
 844                 memcpy(&sa.sin_addr, *ap, he->h_length);
 845
 846                 sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 847                 if ((sockfd < 0) ||
 848                     connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 849                         strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 850                                 host,
 851                                 cnt,
 852                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr),
 853                                 strerror(errno));
 854                         if (0 <= sockfd)
 855                                 close(sockfd);
 856                         sockfd = -1;
 857                         continue;
 858                 }
 859                 if (flags & CONNECT_VERBOSE)
 860                         fprintf(stderr, "%s ",
 861                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr));
 862                 break;
 863         }
 864
 865         if (sockfd < 0)
 866                 die(_("unable to connect to %s:\n%s"), host, error_message.buf);
 867
 868         enable_keepalive(sockfd);
 869
 870         if (flags & CONNECT_VERBOSE)
 871                 /* TRANSLATORS: this is the end of "Connecting to %s (port %s) ... " */
 872                 fprintf_ln(stderr, _("done."));
 873
 874         return sockfd;
 875 }
 876
 877 #endif /* NO_IPV6 */
 878
 879
 880 /*
 881  * Dummy child_process returned by git_connect() if the transport protocol
 882  * does not need fork(2).
 883  */
 884 static struct child_process no_fork = CHILD_PROCESS_INIT;
 885
 886 int git_connection_is_socket(struct child_process *conn)
 887 {
 888         return conn == &no_fork;
 889 }
 890
 891 static struct child_process *git_tcp_connect(int fd[2], char *host, int flags)
 892 {
 893         int sockfd = git_tcp_connect_sock(host, flags);
 894
 895         fd[0] = sockfd;
 896         fd[1] = dup(sockfd);
 897
 898         return &no_fork;
 899 }
 900
 901
 902 static char *git_proxy_command;
 903
 904 static int git_proxy_command_options(const char *var, const char *value,
 905                 void *cb)
 906 {
 907         if (!strcmp(var, "core.gitproxy")) {
 908                 const char *for_pos;
 909                 int matchlen = -1;
 910                 int hostlen;
 911                 const char *rhost_name = cb;
 912                 int rhost_len = strlen(rhost_name);
 913
 914                 if (git_proxy_command)
 915                         return 0;
 916                 if (!value)
 917                         return config_error_nonbool(var);
 918                 /* [core]
 919                  * ;# matches www.kernel.org as well
 920                  * gitproxy = netcatter-1 for kernel.org
 921                  * gitproxy = netcatter-2 for sample.xz
 922                  * gitproxy = netcatter-default
 923                  */
 924                 for_pos = strstr(value, " for ");
 925                 if (!for_pos)
 926                         /* matches everybody */
 927                         matchlen = strlen(value);
 928                 else {
 929                         hostlen = strlen(for_pos + 5);
 930                         if (rhost_len < hostlen)
 931                                 matchlen = -1;
 932                         else if (!strncmp(for_pos + 5,
 933                                           rhost_name + rhost_len - hostlen,
 934                                           hostlen) &&
 935                                  ((rhost_len == hostlen) ||
 936                                   rhost_name[rhost_len - hostlen -1] == '.'))
 937                                 matchlen = for_pos - value;
 938                         else
 939                                 matchlen = -1;
 940                 }
 941                 if (0 <= matchlen) {
 942                         /* core.gitproxy = none for kernel.org */
 943                         if (matchlen == 4 &&
 944                             !memcmp(value, "none", 4))
 945                                 matchlen = 0;
 946                         git_proxy_command = xmemdupz(value, matchlen);
 947                 }
 948                 return 0;
 949         }
 950
 951         return git_default_config(var, value, cb);
 952 }
 953
 954 static int git_use_proxy(const char *host)
 955 {
 956         git_proxy_command = getenv("GIT_PROXY_COMMAND");
 957         git_config(git_proxy_command_options, (void*)host);
 958         return (git_proxy_command && *git_proxy_command);
 959 }
 960
 961 static struct child_process *git_proxy_connect(int fd[2], char *host)
 962 {
 963         const char *port = STR(DEFAULT_GIT_PORT);
 964         struct child_process *proxy;
 965
 966         get_host_and_port(&host, &port);
 967
 968         if (looks_like_command_line_option(host))
 969                 die(_("strange hostname '%s' blocked"), host);
 970         if (looks_like_command_line_option(port))
 971                 die(_("strange port '%s' blocked"), port);
 972
 973         proxy = xmalloc(sizeof(*proxy));
 974         child_process_init(proxy);
 975         strvec_push(&proxy->args, git_proxy_command);
 976         strvec_push(&proxy->args, host);
 977         strvec_push(&proxy->args, port);
 978         proxy->in = -1;
 979         proxy->out = -1;
 980         if (start_command(proxy))
 981                 die(_("cannot start proxy %s"), git_proxy_command);
 982         fd[0] = proxy->out; /* read from proxy stdout */
 983         fd[1] = proxy->in;  /* write to proxy stdin */
 984         return proxy;
 985 }
 986
 987 static char *get_port(char *host)
 988 {
 989         char *end;
 990         char *p = strchr(host, ':');
 991
 992         if (p) {
 993                 long port = strtol(p + 1, &end, 10);
 994                 if (end != p + 1 && *end == '\0' && 0 <= port && port < 65536) {
 995                         *p = '\0';
 996                         return p+1;
 997                 }
 998         }
 999
1000         return NULL;
1001 }
1002
1003 /*
1004  * Extract protocol and relevant parts from the specified connection URL.
1005  * The caller must free() the returned strings.
1006  */
1007 static enum protocol parse_connect_url(const char *url_orig, char **ret_host,
1008                                        char **ret_path)
1009 {
1010         char *url;
1011         char *host, *path;
1012         char *end;
1013         int separator = '/';
1014         enum protocol protocol = PROTO_LOCAL;
1015
1016         if (is_url(url_orig))
1017                 url = url_decode(url_orig);
1018         else
1019                 url = xstrdup(url_orig);
1020
1021         host = strstr(url, "://");
1022         if (host) {
1023                 *host = '\0';
1024                 protocol = get_protocol(url);
1025                 host += 3;
1026         } else {
1027                 host = url;
1028                 if (!url_is_local_not_ssh(url)) {
1029                         protocol = PROTO_SSH;
1030                         separator = ':';
1031                 }
1032         }
1033
1034         /*
1035          * Don't do destructive transforms as protocol code does
1036          * '[]' unwrapping in get_host_and_port()
1037          */
1038         end = host_end(&host, 0);
1039
1040         if (protocol == PROTO_LOCAL)
1041                 path = end;
1042         else if (protocol == PROTO_FILE && *host != '/' &&
1043                  !has_dos_drive_prefix(host) &&
1044                  offset_1st_component(host - 2) > 1)
1045                 path = host - 2; /* include the leading "//" */
1046         else if (protocol == PROTO_FILE && has_dos_drive_prefix(end))
1047                 path = end; /* "file://$(pwd)" may be "file://C:/projects/repo" */
1048         else
1049                 path = strchr(end, separator);
1050
1051         if (!path || !*path)
1052                 die(_("no path specified; see 'git help pull' for valid url syntax"));
1053
1054         /*
1055          * null-terminate hostname and point path to ~ for URL's like this:
1056          *    ssh://host.xz/~user/repo
1057          */
1058
1059         end = path; /* Need to \0 terminate host here */
1060         if (separator == ':')
1061                 path++; /* path starts after ':' */
1062         if (protocol == PROTO_GIT || protocol == PROTO_SSH) {
1063                 if (path[1] == '~')
1064                         path++;
1065         }
1066
1067         path = xstrdup(path);
1068         *end = '\0';
1069
1070         *ret_host = xstrdup(host);
1071         *ret_path = path;
1072         free(url);
1073         return protocol;
1074 }
1075
1076 static const char *get_ssh_command(void)
1077 {
1078         const char *ssh;
1079
1080         if ((ssh = getenv("GIT_SSH_COMMAND")))
1081                 return ssh;
1082
1083         if (!git_config_get_string_tmp("core.sshcommand", &ssh))
1084                 return ssh;
1085
1086         return NULL;
1087 }
1088
1089 enum ssh_variant {
1090         VARIANT_AUTO,
1091         VARIANT_SIMPLE,
1092         VARIANT_SSH,
1093         VARIANT_PLINK,
1094         VARIANT_PUTTY,
1095         VARIANT_TORTOISEPLINK,
1096 };
1097
1098 static void override_ssh_variant(enum ssh_variant *ssh_variant)
1099 {
1100         const char *variant = getenv("GIT_SSH_VARIANT");
1101
1102         if (!variant && git_config_get_string_tmp("ssh.variant", &variant))
1103                 return;
1104
1105         if (!strcmp(variant, "auto"))
1106                 *ssh_variant = VARIANT_AUTO;
1107         else if (!strcmp(variant, "plink"))
1108                 *ssh_variant = VARIANT_PLINK;
1109         else if (!strcmp(variant, "putty"))
1110                 *ssh_variant = VARIANT_PUTTY;
1111         else if (!strcmp(variant, "tortoiseplink"))
1112                 *ssh_variant = VARIANT_TORTOISEPLINK;
1113         else if (!strcmp(variant, "simple"))
1114                 *ssh_variant = VARIANT_SIMPLE;
1115         else
1116                 *ssh_variant = VARIANT_SSH;
1117 }
1118
1119 static enum ssh_variant determine_ssh_variant(const char *ssh_command,
1120                                               int is_cmdline)
1121 {
1122         enum ssh_variant ssh_variant = VARIANT_AUTO;
1123         const char *variant;
1124         char *p = NULL;
1125
1126         override_ssh_variant(&ssh_variant);
1127
1128         if (ssh_variant != VARIANT_AUTO)
1129                 return ssh_variant;
1130
1131         if (!is_cmdline) {
1132                 p = xstrdup(ssh_command);
1133                 variant = basename(p);
1134         } else {
1135                 const char **ssh_argv;
1136
1137                 p = xstrdup(ssh_command);
1138                 if (split_cmdline(p, &ssh_argv) > 0) {
1139                         variant = basename((char *)ssh_argv[0]);
1140                         /*
1141                          * At this point, variant points into the buffer
1142                          * referenced by p, hence we do not need ssh_argv
1143                          * any longer.
1144                          */
1145                         free(ssh_argv);
1146                 } else {
1147                         free(p);
1148                         return ssh_variant;
1149                 }
1150         }
1151
1152         if (!strcasecmp(variant, "ssh") ||
1153             !strcasecmp(variant, "ssh.exe"))
1154                 ssh_variant = VARIANT_SSH;
1155         else if (!strcasecmp(variant, "plink") ||
1156                  !strcasecmp(variant, "plink.exe"))
1157                 ssh_variant = VARIANT_PLINK;
1158         else if (!strcasecmp(variant, "tortoiseplink") ||
1159                  !strcasecmp(variant, "tortoiseplink.exe"))
1160                 ssh_variant = VARIANT_TORTOISEPLINK;
1161
1162         free(p);
1163         return ssh_variant;
1164 }
1165
1166 /*
1167  * Open a connection using Git's native protocol.
1168  *
1169  * The caller is responsible for freeing hostandport, but this function may
1170  * modify it (for example, to truncate it to remove the port part).
1171  */
1172 static struct child_process *git_connect_git(int fd[2], char *hostandport,
1173                                              const char *path, const char *prog,
1174                                              enum protocol_version version,
1175                                              int flags)
1176 {
1177         struct child_process *conn;
1178         struct strbuf request = STRBUF_INIT;
1179         /*
1180          * Set up virtual host information based on where we will
1181          * connect, unless the user has overridden us in
1182          * the environment.
1183          */
1184         char *target_host = getenv("GIT_OVERRIDE_VIRTUAL_HOST");
1185         if (target_host)
1186                 target_host = xstrdup(target_host);
1187         else
1188                 target_host = xstrdup(hostandport);
1189
1190         transport_check_allowed("git");
1191         if (strchr(target_host, '\n') || strchr(path, '\n'))
1192                 die(_("newline is forbidden in git:// hosts and repo paths"));
1193
1194         /*
1195          * These underlying connection commands die() if they
1196          * cannot connect.
1197          */
1198         if (git_use_proxy(hostandport))
1199                 conn = git_proxy_connect(fd, hostandport);
1200         else
1201                 conn = git_tcp_connect(fd, hostandport, flags);
1202         /*
1203          * Separate original protocol components prog and path
1204          * from extended host header with a NUL byte.
1205          *
1206          * Note: Do not add any other headers here!  Doing so
1207          * will cause older git-daemon servers to crash.
1208          */
1209         strbuf_addf(&request,
1210                     "%s %s%chost=%s%c",
1211                     prog, path, 0,
1212                     target_host, 0);
1213
1214         /* If using a new version put that stuff here after a second null byte */
1215         if (version > 0) {
1216                 strbuf_addch(&request, '\0');
1217                 strbuf_addf(&request, "version=%d%c",
1218                             version, '\0');
1219         }
1220
1221         packet_write(fd[1], request.buf, request.len);
1222
1223         free(target_host);
1224         strbuf_release(&request);
1225         return conn;
1226 }
1227
1228 /*
1229  * Append the appropriate environment variables to `env` and options to
1230  * `args` for running ssh in Git's SSH-tunneled transport.
1231  */
1232 static void push_ssh_options(struct strvec *args, struct strvec *env,
1233                              enum ssh_variant variant, const char *port,
1234                              enum protocol_version version, int flags)
1235 {
1236         if (variant == VARIANT_SSH &&
1237             version > 0) {
1238                 strvec_push(args, "-o");
1239                 strvec_push(args, "SendEnv=" GIT_PROTOCOL_ENVIRONMENT);
1240                 strvec_pushf(env, GIT_PROTOCOL_ENVIRONMENT "=version=%d",
1241                              version);
1242         }
1243
1244         if (flags & CONNECT_IPV4) {
1245                 switch (variant) {
1246                 case VARIANT_AUTO:
1247                         BUG("VARIANT_AUTO passed to push_ssh_options");
1248                 case VARIANT_SIMPLE:
1249                         die(_("ssh variant 'simple' does not support -4"));
1250                 case VARIANT_SSH:
1251                 case VARIANT_PLINK:
1252                 case VARIANT_PUTTY:
1253                 case VARIANT_TORTOISEPLINK:
1254                         strvec_push(args, "-4");
1255                 }
1256         } else if (flags & CONNECT_IPV6) {
1257                 switch (variant) {
1258                 case VARIANT_AUTO:
1259                         BUG("VARIANT_AUTO passed to push_ssh_options");
1260                 case VARIANT_SIMPLE:
1261                         die(_("ssh variant 'simple' does not support -6"));
1262                 case VARIANT_SSH:
1263                 case VARIANT_PLINK:
1264                 case VARIANT_PUTTY:
1265                 case VARIANT_TORTOISEPLINK:
1266                         strvec_push(args, "-6");
1267                 }
1268         }
1269
1270         if (variant == VARIANT_TORTOISEPLINK)
1271                 strvec_push(args, "-batch");
1272
1273         if (port) {
1274                 switch (variant) {
1275                 case VARIANT_AUTO:
1276                         BUG("VARIANT_AUTO passed to push_ssh_options");
1277                 case VARIANT_SIMPLE:
1278                         die(_("ssh variant 'simple' does not support setting port"));
1279                 case VARIANT_SSH:
1280                         strvec_push(args, "-p");
1281                         break;
1282                 case VARIANT_PLINK:
1283                 case VARIANT_PUTTY:
1284                 case VARIANT_TORTOISEPLINK:
1285                         strvec_push(args, "-P");
1286                 }
1287
1288                 strvec_push(args, port);
1289         }
1290 }
1291
1292 /* Prepare a child_process for use by Git's SSH-tunneled transport. */
1293 static void fill_ssh_args(struct child_process *conn, const char *ssh_host,
1294                           const char *port, enum protocol_version version,
1295                           int flags)
1296 {
1297         const char *ssh;
1298         enum ssh_variant variant;
1299
1300         if (looks_like_command_line_option(ssh_host))
1301                 die(_("strange hostname '%s' blocked"), ssh_host);
1302
1303         ssh = get_ssh_command();
1304         if (ssh) {
1305                 variant = determine_ssh_variant(ssh, 1);
1306         } else {
1307                 /*
1308                  * GIT_SSH is the no-shell version of
1309                  * GIT_SSH_COMMAND (and must remain so for
1310                  * historical compatibility).
1311                  */
1312                 conn->use_shell = 0;
1313
1314                 ssh = getenv("GIT_SSH");
1315                 if (!ssh)
1316                         ssh = "ssh";
1317                 variant = determine_ssh_variant(ssh, 0);
1318         }
1319
1320         if (variant == VARIANT_AUTO) {
1321                 struct child_process detect = CHILD_PROCESS_INIT;
1322
1323                 detect.use_shell = conn->use_shell;
1324                 detect.no_stdin = detect.no_stdout = detect.no_stderr = 1;
1325
1326                 strvec_push(&detect.args, ssh);
1327                 strvec_push(&detect.args, "-G");
1328                 push_ssh_options(&detect.args, &detect.env_array,
1329                                  VARIANT_SSH, port, version, flags);
1330                 strvec_push(&detect.args, ssh_host);
1331
1332                 variant = run_command(&detect) ? VARIANT_SIMPLE : VARIANT_SSH;
1333         }
1334
1335         strvec_push(&conn->args, ssh);
1336         push_ssh_options(&conn->args, &conn->env_array, variant, port, version, flags);
1337         strvec_push(&conn->args, ssh_host);
1338 }
1339
1340 /*
1341  * This returns the dummy child_process `no_fork` if the transport protocol
1342  * does not need fork(2), or a struct child_process object if it does.  Once
1343  * done, finish the connection with finish_connect() with the value returned
1344  * from this function (it is safe to call finish_connect() with NULL to
1345  * support the former case).
1346  *
1347  * If it returns, the connect is successful; it just dies on errors (this
1348  * will hopefully be changed in a libification effort, to return NULL when
1349  * the connection failed).
1350  */
1351 struct child_process *git_connect(int fd[2], const char *url,
1352                                   const char *prog, int flags)
1353 {
1354         char *hostandport, *path;
1355         struct child_process *conn;
1356         enum protocol protocol;
1357         enum protocol_version version = get_protocol_version_config();
1358
1359         /*
1360          * NEEDSWORK: If we are trying to use protocol v2 and we are planning
1361          * to perform a push, then fallback to v0 since the client doesn't know
1362          * how to push yet using v2.
1363          */
1364         if (version == protocol_v2 && !strcmp("git-receive-pack", prog))
1365                 version = protocol_v0;
1366
1367         /* Without this we cannot rely on waitpid() to tell
1368          * what happened to our children.
1369          */
1370         signal(SIGCHLD, SIG_DFL);
1371
1372         protocol = parse_connect_url(url, &hostandport, &path);
1373         if ((flags & CONNECT_DIAG_URL) && (protocol != PROTO_SSH)) {
1374                 printf("Diag: url=%s\n", url ? url : "NULL");
1375                 printf("Diag: protocol=%s\n", prot_name(protocol));
1376                 printf("Diag: hostandport=%s\n", hostandport ? hostandport : "NULL");
1377                 printf("Diag: path=%s\n", path ? path : "NULL");
1378                 conn = NULL;
1379         } else if (protocol == PROTO_GIT) {
1380                 conn = git_connect_git(fd, hostandport, path, prog, version, flags);
1381                 conn->trace2_child_class = "transport/git";
1382         } else {
1383                 struct strbuf cmd = STRBUF_INIT;
1384                 const char *const *var;
1385
1386                 conn = xmalloc(sizeof(*conn));
1387                 child_process_init(conn);
1388
1389                 if (looks_like_command_line_option(path))
1390                         die(_("strange pathname '%s' blocked"), path);
1391
1392                 strbuf_addstr(&cmd, prog);
1393                 strbuf_addch(&cmd, ' ');
1394                 sq_quote_buf(&cmd, path);
1395
1396                 /* remove repo-local variables from the environment */
1397                 for (var = local_repo_env; *var; var++)
1398                         strvec_push(&conn->env_array, *var);
1399
1400                 conn->use_shell = 1;
1401                 conn->in = conn->out = -1;
1402                 if (protocol == PROTO_SSH) {
1403                         char *ssh_host = hostandport;
1404                         const char *port = NULL;
1405                         transport_check_allowed("ssh");
1406                         get_host_and_port(&ssh_host, &port);
1407
1408                         if (!port)
1409                                 port = get_port(ssh_host);
1410
1411                         if (flags & CONNECT_DIAG_URL) {
1412                                 printf("Diag: url=%s\n", url ? url : "NULL");
1413                                 printf("Diag: protocol=%s\n", prot_name(protocol));
1414                                 printf("Diag: userandhost=%s\n", ssh_host ? ssh_host : "NULL");
1415                                 printf("Diag: port=%s\n", port ? port : "NONE");
1416                                 printf("Diag: path=%s\n", path ? path : "NULL");
1417
1418                                 free(hostandport);
1419                                 free(path);
1420                                 free(conn);
1421                                 strbuf_release(&cmd);
1422                                 return NULL;
1423                         }
1424                         conn->trace2_child_class = "transport/ssh";
1425                         fill_ssh_args(conn, ssh_host, port, version, flags);
1426                 } else {
1427                         transport_check_allowed("file");
1428                         conn->trace2_child_class = "transport/file";
1429                         if (version > 0) {
1430                                 strvec_pushf(&conn->env_array,
1431                                              GIT_PROTOCOL_ENVIRONMENT "=version=%d",
1432                                              version);
1433                         }
1434                 }
1435                 strvec_push(&conn->args, cmd.buf);
1436
1437                 if (start_command(conn))
1438                         die(_("unable to fork"));
1439
1440                 fd[0] = conn->out; /* read from child's stdout */
1441                 fd[1] = conn->in;  /* write to child's stdin */
1442                 strbuf_release(&cmd);
1443         }
1444         free(hostandport);
1445         free(path);
1446         return conn;
1447 }
1448
1449 int finish_connect(struct child_process *conn)
1450 {
1451         int code;
1452         if (!conn || git_connection_is_socket(conn))
1453                 return 0;
1454
1455         code = finish_command(conn);
1456         free(conn);
1457         return code;
1458 }