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)
  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         return 0;
  80 }
  81
  82 void ensure_server_supports_v2(const char *c)
  83 {
  84         if (!server_supports_v2(c))
  85                 die(_("server doesn't support '%s'"), c);
  86 }
  87
  88 int server_feature_v2(const char *c, const char **v)
  89 {
  90         int i;
  91
  92         for (i = 0; i < server_capabilities_v2.nr; i++) {
  93                 const char *out;
  94                 if (skip_prefix(server_capabilities_v2.v[i], c, &out) &&
  95                     (*out == '=')) {
  96                         *v = out + 1;
  97                         return 1;
  98                 }
  99         }
 100         return 0;
 101 }
 102
 103 int server_supports_feature(const char *c, const char *feature,
 104                             int die_on_error)
 105 {
 106         int i;
 107
 108         for (i = 0; i < server_capabilities_v2.nr; i++) {
 109                 const char *out;
 110                 if (skip_prefix(server_capabilities_v2.v[i], c, &out) &&
 111                     (!*out || *(out++) == '=')) {
 112                         if (parse_feature_request(out, feature))
 113                                 return 1;
 114                         else
 115                                 break;
 116                 }
 117         }
 118
 119         if (die_on_error)
 120                 die(_("server doesn't support feature '%s'"), feature);
 121
 122         return 0;
 123 }
 124
 125 static void process_capabilities_v2(struct packet_reader *reader)
 126 {
 127         while (packet_reader_read(reader) == PACKET_READ_NORMAL)
 128                 strvec_push(&server_capabilities_v2, reader->line);
 129
 130         if (reader->status != PACKET_READ_FLUSH)
 131                 die(_("expected flush after capabilities"));
 132 }
 133
 134 enum protocol_version discover_version(struct packet_reader *reader)
 135 {
 136         enum protocol_version version = protocol_unknown_version;
 137
 138         /*
 139          * Peek the first line of the server's response to
 140          * determine the protocol version the server is speaking.
 141          */
 142         switch (packet_reader_peek(reader)) {
 143         case PACKET_READ_EOF:
 144                 die_initial_contact(0);
 145         case PACKET_READ_FLUSH:
 146         case PACKET_READ_DELIM:
 147         case PACKET_READ_RESPONSE_END:
 148                 version = protocol_v0;
 149                 break;
 150         case PACKET_READ_NORMAL:
 151                 version = determine_protocol_version_client(reader->line);
 152                 break;
 153         }
 154
 155         switch (version) {
 156         case protocol_v2:
 157                 process_capabilities_v2(reader);
 158                 break;
 159         case protocol_v1:
 160                 /* Read the peeked version line */
 161                 packet_reader_read(reader);
 162                 break;
 163         case protocol_v0:
 164                 break;
 165         case protocol_unknown_version:
 166                 BUG("unknown protocol version");
 167         }
 168
 169         trace2_data_intmax("transfer", NULL, "negotiated-version", version);
 170
 171         return version;
 172 }
 173
 174 static void parse_one_symref_info(struct string_list *symref, const char *val, int len)
 175 {
 176         char *sym, *target;
 177         struct string_list_item *item;
 178
 179         if (!len)
 180                 return; /* just "symref" */
 181         /* e.g. "symref=HEAD:refs/heads/master" */
 182         sym = xmemdupz(val, len);
 183         target = strchr(sym, ':');
 184         if (!target)
 185                 /* just "symref=something" */
 186                 goto reject;
 187         *(target++) = '\0';
 188         if (check_refname_format(sym, REFNAME_ALLOW_ONELEVEL) ||
 189             check_refname_format(target, REFNAME_ALLOW_ONELEVEL))
 190                 /* "symref=bogus:pair */
 191                 goto reject;
 192         item = string_list_append_nodup(symref, sym);
 193         item->util = target;
 194         return;
 195 reject:
 196         free(sym);
 197         return;
 198 }
 199
 200 static void annotate_refs_with_symref_info(struct ref *ref)
 201 {
 202         struct string_list symref = STRING_LIST_INIT_DUP;
 203         int offset = 0;
 204
 205         while (1) {
 206                 int len;
 207                 const char *val;
 208
 209                 val = next_server_feature_value("symref", &len, &offset);
 210                 if (!val)
 211                         break;
 212                 parse_one_symref_info(&symref, val, len);
 213         }
 214         string_list_sort(&symref);
 215
 216         for (; ref; ref = ref->next) {
 217                 struct string_list_item *item;
 218                 item = string_list_lookup(&symref, ref->name);
 219                 if (!item)
 220                         continue;
 221                 ref->symref = xstrdup((char *)item->util);
 222         }
 223         string_list_clear(&symref, 0);
 224 }
 225
 226 static void process_capabilities(struct packet_reader *reader, int *linelen)
 227 {
 228         const char *feat_val;
 229         int feat_len;
 230         const char *line = reader->line;
 231         int nul_location = strlen(line);
 232         if (nul_location == *linelen)
 233                 return;
 234         server_capabilities_v1 = xstrdup(line + nul_location + 1);
 235         *linelen = nul_location;
 236
 237         feat_val = server_feature_value("object-format", &feat_len);
 238         if (feat_val) {
 239                 char *hash_name = xstrndup(feat_val, feat_len);
 240                 int hash_algo = hash_algo_by_name(hash_name);
 241                 if (hash_algo != GIT_HASH_UNKNOWN)
 242                         reader->hash_algo = &hash_algos[hash_algo];
 243                 free(hash_name);
 244         } else {
 245                 reader->hash_algo = &hash_algos[GIT_HASH_SHA1];
 246         }
 247 }
 248
 249 static int process_dummy_ref(const struct packet_reader *reader)
 250 {
 251         const char *line = reader->line;
 252         struct object_id oid;
 253         const char *name;
 254
 255         if (parse_oid_hex_algop(line, &oid, &name, reader->hash_algo))
 256                 return 0;
 257         if (*name != ' ')
 258                 return 0;
 259         name++;
 260
 261         return oideq(null_oid(), &oid) && !strcmp(name, "capabilities^{}");
 262 }
 263
 264 static void check_no_capabilities(const char *line, int len)
 265 {
 266         if (strlen(line) != len)
 267                 warning(_("ignoring capabilities after first line '%s'"),
 268                         line + strlen(line));
 269 }
 270
 271 static int process_ref(const struct packet_reader *reader, int len,
 272                        struct ref ***list, unsigned int flags,
 273                        struct oid_array *extra_have)
 274 {
 275         const char *line = reader->line;
 276         struct object_id old_oid;
 277         const char *name;
 278
 279         if (parse_oid_hex_algop(line, &old_oid, &name, reader->hash_algo))
 280                 return 0;
 281         if (*name != ' ')
 282                 return 0;
 283         name++;
 284
 285         if (extra_have && !strcmp(name, ".have")) {
 286                 oid_array_append(extra_have, &old_oid);
 287         } else if (!strcmp(name, "capabilities^{}")) {
 288                 die(_("protocol error: unexpected capabilities^{}"));
 289         } else if (check_ref(name, flags)) {
 290                 struct ref *ref = alloc_ref(name);
 291                 oidcpy(&ref->old_oid, &old_oid);
 292                 **list = ref;
 293                 *list = &ref->next;
 294         }
 295         check_no_capabilities(line, len);
 296         return 1;
 297 }
 298
 299 static int process_shallow(const struct packet_reader *reader, int len,
 300                            struct oid_array *shallow_points)
 301 {
 302         const char *line = reader->line;
 303         const char *arg;
 304         struct object_id old_oid;
 305
 306         if (!skip_prefix(line, "shallow ", &arg))
 307                 return 0;
 308
 309         if (get_oid_hex_algop(arg, &old_oid, reader->hash_algo))
 310                 die(_("protocol error: expected shallow sha-1, got '%s'"), arg);
 311         if (!shallow_points)
 312                 die(_("repository on the other end cannot be shallow"));
 313         oid_array_append(shallow_points, &old_oid);
 314         check_no_capabilities(line, len);
 315         return 1;
 316 }
 317
 318 enum get_remote_heads_state {
 319         EXPECTING_FIRST_REF = 0,
 320         EXPECTING_REF,
 321         EXPECTING_SHALLOW,
 322         EXPECTING_DONE,
 323 };
 324
 325 /*
 326  * Read all the refs from the other end
 327  */
 328 struct ref **get_remote_heads(struct packet_reader *reader,
 329                               struct ref **list, unsigned int flags,
 330                               struct oid_array *extra_have,
 331                               struct oid_array *shallow_points)
 332 {
 333         struct ref **orig_list = list;
 334         int len = 0;
 335         enum get_remote_heads_state state = EXPECTING_FIRST_REF;
 336
 337         *list = NULL;
 338
 339         while (state != EXPECTING_DONE) {
 340                 switch (packet_reader_read(reader)) {
 341                 case PACKET_READ_EOF:
 342                         die_initial_contact(1);
 343                 case PACKET_READ_NORMAL:
 344                         len = reader->pktlen;
 345                         break;
 346                 case PACKET_READ_FLUSH:
 347                         state = EXPECTING_DONE;
 348                         break;
 349                 case PACKET_READ_DELIM:
 350                 case PACKET_READ_RESPONSE_END:
 351                         die(_("invalid packet"));
 352                 }
 353
 354                 switch (state) {
 355                 case EXPECTING_FIRST_REF:
 356                         process_capabilities(reader, &len);
 357                         if (process_dummy_ref(reader)) {
 358                                 state = EXPECTING_SHALLOW;
 359                                 break;
 360                         }
 361                         state = EXPECTING_REF;
 362                         /* fallthrough */
 363                 case EXPECTING_REF:
 364                         if (process_ref(reader, len, &list, flags, extra_have))
 365                                 break;
 366                         state = EXPECTING_SHALLOW;
 367                         /* fallthrough */
 368                 case EXPECTING_SHALLOW:
 369                         if (process_shallow(reader, len, shallow_points))
 370                                 break;
 371                         die(_("protocol error: unexpected '%s'"), reader->line);
 372                 case EXPECTING_DONE:
 373                         break;
 374                 }
 375         }
 376
 377         annotate_refs_with_symref_info(*orig_list);
 378
 379         return list;
 380 }
 381
 382 /* Returns 1 when a valid ref has been added to `list`, 0 otherwise */
 383 static int process_ref_v2(struct packet_reader *reader, struct ref ***list,
 384                           const char **unborn_head_target)
 385 {
 386         int ret = 1;
 387         int i = 0;
 388         struct object_id old_oid;
 389         struct ref *ref;
 390         struct string_list line_sections = STRING_LIST_INIT_DUP;
 391         const char *end;
 392         const char *line = reader->line;
 393
 394         /*
 395          * Ref lines have a number of fields which are space deliminated.  The
 396          * first field is the OID of the ref.  The second field is the ref
 397          * name.  Subsequent fields (symref-target and peeled) are optional and
 398          * don't have a particular order.
 399          */
 400         if (string_list_split(&line_sections, line, ' ', -1) < 2) {
 401                 ret = 0;
 402                 goto out;
 403         }
 404
 405         if (!strcmp("unborn", line_sections.items[i].string)) {
 406                 i++;
 407                 if (unborn_head_target &&
 408                     !strcmp("HEAD", line_sections.items[i++].string)) {
 409                         /*
 410                          * Look for the symref target (if any). If found,
 411                          * return it to the caller.
 412                          */
 413                         for (; i < line_sections.nr; i++) {
 414                                 const char *arg = line_sections.items[i].string;
 415
 416                                 if (skip_prefix(arg, "symref-target:", &arg)) {
 417                                         *unborn_head_target = xstrdup(arg);
 418                                         break;
 419                                 }
 420                         }
 421                 }
 422                 goto out;
 423         }
 424         if (parse_oid_hex_algop(line_sections.items[i++].string, &old_oid, &end, reader->hash_algo) ||
 425             *end) {
 426                 ret = 0;
 427                 goto out;
 428         }
 429
 430         ref = alloc_ref(line_sections.items[i++].string);
 431
 432         memcpy(ref->old_oid.hash, old_oid.hash, reader->hash_algo->rawsz);
 433         **list = ref;
 434         *list = &ref->next;
 435
 436         for (; i < line_sections.nr; i++) {
 437                 const char *arg = line_sections.items[i].string;
 438                 if (skip_prefix(arg, "symref-target:", &arg))
 439                         ref->symref = xstrdup(arg);
 440
 441                 if (skip_prefix(arg, "peeled:", &arg)) {
 442                         struct object_id peeled_oid;
 443                         char *peeled_name;
 444                         struct ref *peeled;
 445                         if (parse_oid_hex_algop(arg, &peeled_oid, &end,
 446                                                 reader->hash_algo) || *end) {
 447                                 ret = 0;
 448                                 goto out;
 449                         }
 450
 451                         peeled_name = xstrfmt("%s^{}", ref->name);
 452                         peeled = alloc_ref(peeled_name);
 453
 454                         memcpy(peeled->old_oid.hash, peeled_oid.hash,
 455                                reader->hash_algo->rawsz);
 456                         **list = peeled;
 457                         *list = &peeled->next;
 458
 459                         free(peeled_name);
 460                 }
 461         }
 462
 463 out:
 464         string_list_clear(&line_sections, 0);
 465         return ret;
 466 }
 467
 468 void check_stateless_delimiter(int stateless_rpc,
 469                               struct packet_reader *reader,
 470                               const char *error)
 471 {
 472         if (!stateless_rpc)
 473                 return; /* not in stateless mode, no delimiter expected */
 474         if (packet_reader_read(reader) != PACKET_READ_RESPONSE_END)
 475                 die("%s", error);
 476 }
 477
 478 static void send_capabilities(int fd_out, struct packet_reader *reader)
 479 {
 480         const char *hash_name;
 481
 482         if (server_supports_v2("agent"))
 483                 packet_write_fmt(fd_out, "agent=%s", git_user_agent_sanitized());
 484
 485         if (server_feature_v2("object-format", &hash_name)) {
 486                 int hash_algo = hash_algo_by_name(hash_name);
 487                 if (hash_algo == GIT_HASH_UNKNOWN)
 488                         die(_("unknown object format '%s' specified by server"), hash_name);
 489                 reader->hash_algo = &hash_algos[hash_algo];
 490                 packet_write_fmt(fd_out, "object-format=%s", reader->hash_algo->name);
 491         } else {
 492                 reader->hash_algo = &hash_algos[GIT_HASH_SHA1];
 493         }
 494 }
 495
 496 struct ref **get_remote_refs(int fd_out, struct packet_reader *reader,
 497                              struct ref **list, int for_push,
 498                              struct transport_ls_refs_options *transport_options,
 499                              const struct string_list *server_options,
 500                              int stateless_rpc)
 501 {
 502         int i;
 503         struct strvec *ref_prefixes = transport_options ?
 504                 &transport_options->ref_prefixes : NULL;
 505         const char **unborn_head_target = transport_options ?
 506                 &transport_options->unborn_head_target : NULL;
 507         *list = NULL;
 508
 509         ensure_server_supports_v2("ls-refs");
 510         packet_write_fmt(fd_out, "command=ls-refs\n");
 511
 512         /* Send capabilities */
 513         send_capabilities(fd_out, reader);
 514
 515         if (server_options && server_options->nr) {
 516                 ensure_server_supports_v2("server-option");
 517                 for (i = 0; i < server_options->nr; i++)
 518                         packet_write_fmt(fd_out, "server-option=%s",
 519                                          server_options->items[i].string);
 520         }
 521
 522         packet_delim(fd_out);
 523         /* When pushing we don't want to request the peeled tags */
 524         if (!for_push)
 525                 packet_write_fmt(fd_out, "peel\n");
 526         packet_write_fmt(fd_out, "symrefs\n");
 527         if (server_supports_feature("ls-refs", "unborn", 0))
 528                 packet_write_fmt(fd_out, "unborn\n");
 529         for (i = 0; ref_prefixes && i < ref_prefixes->nr; i++) {
 530                 packet_write_fmt(fd_out, "ref-prefix %s\n",
 531                                  ref_prefixes->v[i]);
 532         }
 533         packet_flush(fd_out);
 534
 535         /* Process response from server */
 536         while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
 537                 if (!process_ref_v2(reader, &list, unborn_head_target))
 538                         die(_("invalid ls-refs response: %s"), reader->line);
 539         }
 540
 541         if (reader->status != PACKET_READ_FLUSH)
 542                 die(_("expected flush after ref listing"));
 543
 544         check_stateless_delimiter(stateless_rpc, reader,
 545                                   _("expected response end packet after ref listing"));
 546
 547         return list;
 548 }
 549
 550 const char *parse_feature_value(const char *feature_list, const char *feature, int *lenp, int *offset)
 551 {
 552         int len;
 553
 554         if (!feature_list)
 555                 return NULL;
 556
 557         len = strlen(feature);
 558         if (offset)
 559                 feature_list += *offset;
 560         while (*feature_list) {
 561                 const char *found = strstr(feature_list, feature);
 562                 if (!found)
 563                         return NULL;
 564                 if (feature_list == found || isspace(found[-1])) {
 565                         const char *value = found + len;
 566                         /* feature with no value (e.g., "thin-pack") */
 567                         if (!*value || isspace(*value)) {
 568                                 if (lenp)
 569                                         *lenp = 0;
 570                                 if (offset)
 571                                         *offset = found + len - feature_list;
 572                                 return value;
 573                         }
 574                         /* feature with a value (e.g., "agent=git/1.2.3") */
 575                         else if (*value == '=') {
 576                                 int end;
 577
 578                                 value++;
 579                                 end = strcspn(value, " \t\n");
 580                                 if (lenp)
 581                                         *lenp = end;
 582                                 if (offset)
 583                                         *offset = value + end - feature_list;
 584                                 return value;
 585                         }
 586                         /*
 587                          * otherwise we matched a substring of another feature;
 588                          * keep looking
 589                          */
 590                 }
 591                 feature_list = found + 1;
 592         }
 593         return NULL;
 594 }
 595
 596 int server_supports_hash(const char *desired, int *feature_supported)
 597 {
 598         int offset = 0;
 599         int len;
 600         const char *hash;
 601
 602         hash = next_server_feature_value("object-format", &len, &offset);
 603         if (feature_supported)
 604                 *feature_supported = !!hash;
 605         if (!hash) {
 606                 hash = hash_algos[GIT_HASH_SHA1].name;
 607                 len = strlen(hash);
 608         }
 609         while (hash) {
 610                 if (!xstrncmpz(desired, hash, len))
 611                         return 1;
 612
 613                 hash = next_server_feature_value("object-format", &len, &offset);
 614         }
 615         return 0;
 616 }
 617
 618 int parse_feature_request(const char *feature_list, const char *feature)
 619 {
 620         return !!parse_feature_value(feature_list, feature, NULL, NULL);
 621 }
 622
 623 static const char *next_server_feature_value(const char *feature, int *len, int *offset)
 624 {
 625         return parse_feature_value(server_capabilities_v1, feature, len, offset);
 626 }
 627
 628 const char *server_feature_value(const char *feature, int *len)
 629 {
 630         return parse_feature_value(server_capabilities_v1, feature, len, NULL);
 631 }
 632
 633 int server_supports(const char *feature)
 634 {
 635         return !!server_feature_value(feature, NULL);
 636 }
 637
 638 enum protocol {
 639         PROTO_LOCAL = 1,
 640         PROTO_FILE,
 641         PROTO_SSH,
 642         PROTO_GIT
 643 };
 644
 645 int url_is_local_not_ssh(const char *url)
 646 {
 647         const char *colon = strchr(url, ':');
 648         const char *slash = strchr(url, '/');
 649         return !colon || (slash && slash < colon) ||
 650                 (has_dos_drive_prefix(url) && is_valid_path(url));
 651 }
 652
 653 static const char *prot_name(enum protocol protocol)
 654 {
 655         switch (protocol) {
 656                 case PROTO_LOCAL:
 657                 case PROTO_FILE:
 658                         return "file";
 659                 case PROTO_SSH:
 660                         return "ssh";
 661                 case PROTO_GIT:
 662                         return "git";
 663                 default:
 664                         return "unknown protocol";
 665         }
 666 }
 667
 668 static enum protocol get_protocol(const char *name)
 669 {
 670         if (!strcmp(name, "ssh"))
 671                 return PROTO_SSH;
 672         if (!strcmp(name, "git"))
 673                 return PROTO_GIT;
 674         if (!strcmp(name, "git+ssh")) /* deprecated - do not use */
 675                 return PROTO_SSH;
 676         if (!strcmp(name, "ssh+git")) /* deprecated - do not use */
 677                 return PROTO_SSH;
 678         if (!strcmp(name, "file"))
 679                 return PROTO_FILE;
 680         die(_("protocol '%s' is not supported"), name);
 681 }
 682
 683 static char *host_end(char **hoststart, int removebrackets)
 684 {
 685         char *host = *hoststart;
 686         char *end;
 687         char *start = strstr(host, "@[");
 688         if (start)
 689                 start++; /* Jump over '@' */
 690         else
 691                 start = host;
 692         if (start[0] == '[') {
 693                 end = strchr(start + 1, ']');
 694                 if (end) {
 695                         if (removebrackets) {
 696                                 *end = 0;
 697                                 memmove(start, start + 1, end - start);
 698                                 end++;
 699                         }
 700                 } else
 701                         end = host;
 702         } else
 703                 end = host;
 704         return end;
 705 }
 706
 707 #define STR_(s) # s
 708 #define STR(s)  STR_(s)
 709
 710 static void get_host_and_port(char **host, const char **port)
 711 {
 712         char *colon, *end;
 713         end = host_end(host, 1);
 714         colon = strchr(end, ':');
 715         if (colon) {
 716                 long portnr = strtol(colon + 1, &end, 10);
 717                 if (end != colon + 1 && *end == '\0' && 0 <= portnr && portnr < 65536) {
 718                         *colon = 0;
 719                         *port = colon + 1;
 720                 } else if (!colon[1]) {
 721                         *colon = 0;
 722                 }
 723         }
 724 }
 725
 726 static void enable_keepalive(int sockfd)
 727 {
 728         int ka = 1;
 729
 730         if (setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, &ka, sizeof(ka)) < 0)
 731                 error_errno(_("unable to set SO_KEEPALIVE on socket"));
 732 }
 733
 734 #ifndef NO_IPV6
 735
 736 static const char *ai_name(const struct addrinfo *ai)
 737 {
 738         static char addr[NI_MAXHOST];
 739         if (getnameinfo(ai->ai_addr, ai->ai_addrlen, addr, sizeof(addr), NULL, 0,
 740                         NI_NUMERICHOST) != 0)
 741                 xsnprintf(addr, sizeof(addr), "(unknown)");
 742
 743         return addr;
 744 }
 745
 746 /*
 747  * Returns a connected socket() fd, or else die()s.
 748  */
 749 static int git_tcp_connect_sock(char *host, int flags)
 750 {
 751         struct strbuf error_message = STRBUF_INIT;
 752         int sockfd = -1;
 753         const char *port = STR(DEFAULT_GIT_PORT);
 754         struct addrinfo hints, *ai0, *ai;
 755         int gai;
 756         int cnt = 0;
 757
 758         get_host_and_port(&host, &port);
 759         if (!*port)
 760                 port = "<none>";
 761
 762         memset(&hints, 0, sizeof(hints));
 763         if (flags & CONNECT_IPV4)
 764                 hints.ai_family = AF_INET;
 765         else if (flags & CONNECT_IPV6)
 766                 hints.ai_family = AF_INET6;
 767         hints.ai_socktype = SOCK_STREAM;
 768         hints.ai_protocol = IPPROTO_TCP;
 769
 770         if (flags & CONNECT_VERBOSE)
 771                 fprintf(stderr, _("Looking up %s ... "), host);
 772
 773         gai = getaddrinfo(host, port, &hints, &ai);
 774         if (gai)
 775                 die(_("unable to look up %s (port %s) (%s)"), host, port, gai_strerror(gai));
 776
 777         if (flags & CONNECT_VERBOSE)
 778                 /* TRANSLATORS: this is the end of "Looking up %s ... " */
 779                 fprintf(stderr, _("done.\nConnecting to %s (port %s) ... "), host, port);
 780
 781         for (ai0 = ai; ai; ai = ai->ai_next, cnt++) {
 782                 sockfd = socket(ai->ai_family,
 783                                 ai->ai_socktype, ai->ai_protocol);
 784                 if ((sockfd < 0) ||
 785                     (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0)) {
 786                         strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 787                                     host, cnt, ai_name(ai), strerror(errno));
 788                         if (0 <= sockfd)
 789                                 close(sockfd);
 790                         sockfd = -1;
 791                         continue;
 792                 }
 793                 if (flags & CONNECT_VERBOSE)
 794                         fprintf(stderr, "%s ", ai_name(ai));
 795                 break;
 796         }
 797
 798         freeaddrinfo(ai0);
 799
 800         if (sockfd < 0)
 801                 die(_("unable to connect to %s:\n%s"), host, error_message.buf);
 802
 803         enable_keepalive(sockfd);
 804
 805         if (flags & CONNECT_VERBOSE)
 806                 /* TRANSLATORS: this is the end of "Connecting to %s (port %s) ... " */
 807                 fprintf_ln(stderr, _("done."));
 808
 809         strbuf_release(&error_message);
 810
 811         return sockfd;
 812 }
 813
 814 #else /* NO_IPV6 */
 815
 816 /*
 817  * Returns a connected socket() fd, or else die()s.
 818  */
 819 static int git_tcp_connect_sock(char *host, int flags)
 820 {
 821         struct strbuf error_message = STRBUF_INIT;
 822         int sockfd = -1;
 823         const char *port = STR(DEFAULT_GIT_PORT);
 824         char *ep;
 825         struct hostent *he;
 826         struct sockaddr_in sa;
 827         char **ap;
 828         unsigned int nport;
 829         int cnt;
 830
 831         get_host_and_port(&host, &port);
 832
 833         if (flags & CONNECT_VERBOSE)
 834                 fprintf(stderr, _("Looking up %s ... "), host);
 835
 836         he = gethostbyname(host);
 837         if (!he)
 838                 die(_("unable to look up %s (%s)"), host, hstrerror(h_errno));
 839         nport = strtoul(port, &ep, 10);
 840         if ( ep == port || *ep ) {
 841                 /* Not numeric */
 842                 struct servent *se = getservbyname(port,"tcp");
 843                 if ( !se )
 844                         die(_("unknown port %s"), port);
 845                 nport = se->s_port;
 846         }
 847
 848         if (flags & CONNECT_VERBOSE)
 849                 /* TRANSLATORS: this is the end of "Looking up %s ... " */
 850                 fprintf(stderr, _("done.\nConnecting to %s (port %s) ... "), host, port);
 851
 852         for (cnt = 0, ap = he->h_addr_list; *ap; ap++, cnt++) {
 853                 memset(&sa, 0, sizeof sa);
 854                 sa.sin_family = he->h_addrtype;
 855                 sa.sin_port = htons(nport);
 856                 memcpy(&sa.sin_addr, *ap, he->h_length);
 857
 858                 sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 859                 if ((sockfd < 0) ||
 860                     connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 861                         strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 862                                 host,
 863                                 cnt,
 864                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr),
 865                                 strerror(errno));
 866                         if (0 <= sockfd)
 867                                 close(sockfd);
 868                         sockfd = -1;
 869                         continue;
 870                 }
 871                 if (flags & CONNECT_VERBOSE)
 872                         fprintf(stderr, "%s ",
 873                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr));
 874                 break;
 875         }
 876
 877         if (sockfd < 0)
 878                 die(_("unable to connect to %s:\n%s"), host, error_message.buf);
 879
 880         enable_keepalive(sockfd);
 881
 882         if (flags & CONNECT_VERBOSE)
 883                 /* TRANSLATORS: this is the end of "Connecting to %s (port %s) ... " */
 884                 fprintf_ln(stderr, _("done."));
 885
 886         return sockfd;
 887 }
 888
 889 #endif /* NO_IPV6 */
 890
 891
 892 /*
 893  * Dummy child_process returned by git_connect() if the transport protocol
 894  * does not need fork(2).
 895  */
 896 static struct child_process no_fork = CHILD_PROCESS_INIT;
 897
 898 int git_connection_is_socket(struct child_process *conn)
 899 {
 900         return conn == &no_fork;
 901 }
 902
 903 static struct child_process *git_tcp_connect(int fd[2], char *host, int flags)
 904 {
 905         int sockfd = git_tcp_connect_sock(host, flags);
 906
 907         fd[0] = sockfd;
 908         fd[1] = dup(sockfd);
 909
 910         return &no_fork;
 911 }
 912
 913
 914 static char *git_proxy_command;
 915
 916 static int git_proxy_command_options(const char *var, const char *value,
 917                 void *cb)
 918 {
 919         if (!strcmp(var, "core.gitproxy")) {
 920                 const char *for_pos;
 921                 int matchlen = -1;
 922                 int hostlen;
 923                 const char *rhost_name = cb;
 924                 int rhost_len = strlen(rhost_name);
 925
 926                 if (git_proxy_command)
 927                         return 0;
 928                 if (!value)
 929                         return config_error_nonbool(var);
 930                 /* [core]
 931                  * ;# matches www.kernel.org as well
 932                  * gitproxy = netcatter-1 for kernel.org
 933                  * gitproxy = netcatter-2 for sample.xz
 934                  * gitproxy = netcatter-default
 935                  */
 936                 for_pos = strstr(value, " for ");
 937                 if (!for_pos)
 938                         /* matches everybody */
 939                         matchlen = strlen(value);
 940                 else {
 941                         hostlen = strlen(for_pos + 5);
 942                         if (rhost_len < hostlen)
 943                                 matchlen = -1;
 944                         else if (!strncmp(for_pos + 5,
 945                                           rhost_name + rhost_len - hostlen,
 946                                           hostlen) &&
 947                                  ((rhost_len == hostlen) ||
 948                                   rhost_name[rhost_len - hostlen -1] == '.'))
 949                                 matchlen = for_pos - value;
 950                         else
 951                                 matchlen = -1;
 952                 }
 953                 if (0 <= matchlen) {
 954                         /* core.gitproxy = none for kernel.org */
 955                         if (matchlen == 4 &&
 956                             !memcmp(value, "none", 4))
 957                                 matchlen = 0;
 958                         git_proxy_command = xmemdupz(value, matchlen);
 959                 }
 960                 return 0;
 961         }
 962
 963         return git_default_config(var, value, cb);
 964 }
 965
 966 static int git_use_proxy(const char *host)
 967 {
 968         git_proxy_command = getenv("GIT_PROXY_COMMAND");
 969         git_config(git_proxy_command_options, (void*)host);
 970         return (git_proxy_command && *git_proxy_command);
 971 }
 972
 973 static struct child_process *git_proxy_connect(int fd[2], char *host)
 974 {
 975         const char *port = STR(DEFAULT_GIT_PORT);
 976         struct child_process *proxy;
 977
 978         get_host_and_port(&host, &port);
 979
 980         if (looks_like_command_line_option(host))
 981                 die(_("strange hostname '%s' blocked"), host);
 982         if (looks_like_command_line_option(port))
 983                 die(_("strange port '%s' blocked"), port);
 984
 985         proxy = xmalloc(sizeof(*proxy));
 986         child_process_init(proxy);
 987         strvec_push(&proxy->args, git_proxy_command);
 988         strvec_push(&proxy->args, host);
 989         strvec_push(&proxy->args, port);
 990         proxy->in = -1;
 991         proxy->out = -1;
 992         if (start_command(proxy))
 993                 die(_("cannot start proxy %s"), git_proxy_command);
 994         fd[0] = proxy->out; /* read from proxy stdout */
 995         fd[1] = proxy->in;  /* write to proxy stdin */
 996         return proxy;
 997 }
 998
 999 static char *get_port(char *host)
1000 {
1001         char *end;
1002         char *p = strchr(host, ':');
1003
1004         if (p) {
1005                 long port = strtol(p + 1, &end, 10);
1006                 if (end != p + 1 && *end == '\0' && 0 <= port && port < 65536) {
1007                         *p = '\0';
1008                         return p+1;
1009                 }
1010         }
1011
1012         return NULL;
1013 }
1014
1015 /*
1016  * Extract protocol and relevant parts from the specified connection URL.
1017  * The caller must free() the returned strings.
1018  */
1019 static enum protocol parse_connect_url(const char *url_orig, char **ret_host,
1020                                        char **ret_path)
1021 {
1022         char *url;
1023         char *host, *path;
1024         char *end;
1025         int separator = '/';
1026         enum protocol protocol = PROTO_LOCAL;
1027
1028         if (is_url(url_orig))
1029                 url = url_decode(url_orig);
1030         else
1031                 url = xstrdup(url_orig);
1032
1033         host = strstr(url, "://");
1034         if (host) {
1035                 *host = '\0';
1036                 protocol = get_protocol(url);
1037                 host += 3;
1038         } else {
1039                 host = url;
1040                 if (!url_is_local_not_ssh(url)) {
1041                         protocol = PROTO_SSH;
1042                         separator = ':';
1043                 }
1044         }
1045
1046         /*
1047          * Don't do destructive transforms as protocol code does
1048          * '[]' unwrapping in get_host_and_port()
1049          */
1050         end = host_end(&host, 0);
1051
1052         if (protocol == PROTO_LOCAL)
1053                 path = end;
1054         else if (protocol == PROTO_FILE && *host != '/' &&
1055                  !has_dos_drive_prefix(host) &&
1056                  offset_1st_component(host - 2) > 1)
1057                 path = host - 2; /* include the leading "//" */
1058         else if (protocol == PROTO_FILE && has_dos_drive_prefix(end))
1059                 path = end; /* "file://$(pwd)" may be "file://C:/projects/repo" */
1060         else
1061                 path = strchr(end, separator);
1062
1063         if (!path || !*path)
1064                 die(_("no path specified; see 'git help pull' for valid url syntax"));
1065
1066         /*
1067          * null-terminate hostname and point path to ~ for URL's like this:
1068          *    ssh://host.xz/~user/repo
1069          */
1070
1071         end = path; /* Need to \0 terminate host here */
1072         if (separator == ':')
1073                 path++; /* path starts after ':' */
1074         if (protocol == PROTO_GIT || protocol == PROTO_SSH) {
1075                 if (path[1] == '~')
1076                         path++;
1077         }
1078
1079         path = xstrdup(path);
1080         *end = '\0';
1081
1082         *ret_host = xstrdup(host);
1083         *ret_path = path;
1084         free(url);
1085         return protocol;
1086 }
1087
1088 static const char *get_ssh_command(void)
1089 {
1090         const char *ssh;
1091
1092         if ((ssh = getenv("GIT_SSH_COMMAND")))
1093                 return ssh;
1094
1095         if (!git_config_get_string_tmp("core.sshcommand", &ssh))
1096                 return ssh;
1097
1098         return NULL;
1099 }
1100
1101 enum ssh_variant {
1102         VARIANT_AUTO,
1103         VARIANT_SIMPLE,
1104         VARIANT_SSH,
1105         VARIANT_PLINK,
1106         VARIANT_PUTTY,
1107         VARIANT_TORTOISEPLINK,
1108 };
1109
1110 static void override_ssh_variant(enum ssh_variant *ssh_variant)
1111 {
1112         const char *variant = getenv("GIT_SSH_VARIANT");
1113
1114         if (!variant && git_config_get_string_tmp("ssh.variant", &variant))
1115                 return;
1116
1117         if (!strcmp(variant, "auto"))
1118                 *ssh_variant = VARIANT_AUTO;
1119         else if (!strcmp(variant, "plink"))
1120                 *ssh_variant = VARIANT_PLINK;
1121         else if (!strcmp(variant, "putty"))
1122                 *ssh_variant = VARIANT_PUTTY;
1123         else if (!strcmp(variant, "tortoiseplink"))
1124                 *ssh_variant = VARIANT_TORTOISEPLINK;
1125         else if (!strcmp(variant, "simple"))
1126                 *ssh_variant = VARIANT_SIMPLE;
1127         else
1128                 *ssh_variant = VARIANT_SSH;
1129 }
1130
1131 static enum ssh_variant determine_ssh_variant(const char *ssh_command,
1132                                               int is_cmdline)
1133 {
1134         enum ssh_variant ssh_variant = VARIANT_AUTO;
1135         const char *variant;
1136         char *p = NULL;
1137
1138         override_ssh_variant(&ssh_variant);
1139
1140         if (ssh_variant != VARIANT_AUTO)
1141                 return ssh_variant;
1142
1143         if (!is_cmdline) {
1144                 p = xstrdup(ssh_command);
1145                 variant = basename(p);
1146         } else {
1147                 const char **ssh_argv;
1148
1149                 p = xstrdup(ssh_command);
1150                 if (split_cmdline(p, &ssh_argv) > 0) {
1151                         variant = basename((char *)ssh_argv[0]);
1152                         /*
1153                          * At this point, variant points into the buffer
1154                          * referenced by p, hence we do not need ssh_argv
1155                          * any longer.
1156                          */
1157                         free(ssh_argv);
1158                 } else {
1159                         free(p);
1160                         return ssh_variant;
1161                 }
1162         }
1163
1164         if (!strcasecmp(variant, "ssh") ||
1165             !strcasecmp(variant, "ssh.exe"))
1166                 ssh_variant = VARIANT_SSH;
1167         else if (!strcasecmp(variant, "plink") ||
1168                  !strcasecmp(variant, "plink.exe"))
1169                 ssh_variant = VARIANT_PLINK;
1170         else if (!strcasecmp(variant, "tortoiseplink") ||
1171                  !strcasecmp(variant, "tortoiseplink.exe"))
1172                 ssh_variant = VARIANT_TORTOISEPLINK;
1173
1174         free(p);
1175         return ssh_variant;
1176 }
1177
1178 /*
1179  * Open a connection using Git's native protocol.
1180  *
1181  * The caller is responsible for freeing hostandport, but this function may
1182  * modify it (for example, to truncate it to remove the port part).
1183  */
1184 static struct child_process *git_connect_git(int fd[2], char *hostandport,
1185                                              const char *path, const char *prog,
1186                                              enum protocol_version version,
1187                                              int flags)
1188 {
1189         struct child_process *conn;
1190         struct strbuf request = STRBUF_INIT;
1191         /*
1192          * Set up virtual host information based on where we will
1193          * connect, unless the user has overridden us in
1194          * the environment.
1195          */
1196         char *target_host = getenv("GIT_OVERRIDE_VIRTUAL_HOST");
1197         if (target_host)
1198                 target_host = xstrdup(target_host);
1199         else
1200                 target_host = xstrdup(hostandport);
1201
1202         transport_check_allowed("git");
1203         if (strchr(target_host, '\n') || strchr(path, '\n'))
1204                 die(_("newline is forbidden in git:// hosts and repo paths"));
1205
1206         /*
1207          * These underlying connection commands die() if they
1208          * cannot connect.
1209          */
1210         if (git_use_proxy(hostandport))
1211                 conn = git_proxy_connect(fd, hostandport);
1212         else
1213                 conn = git_tcp_connect(fd, hostandport, flags);
1214         /*
1215          * Separate original protocol components prog and path
1216          * from extended host header with a NUL byte.
1217          *
1218          * Note: Do not add any other headers here!  Doing so
1219          * will cause older git-daemon servers to crash.
1220          */
1221         strbuf_addf(&request,
1222                     "%s %s%chost=%s%c",
1223                     prog, path, 0,
1224                     target_host, 0);
1225
1226         /* If using a new version put that stuff here after a second null byte */
1227         if (version > 0) {
1228                 strbuf_addch(&request, '\0');
1229                 strbuf_addf(&request, "version=%d%c",
1230                             version, '\0');
1231         }
1232
1233         packet_write(fd[1], request.buf, request.len);
1234
1235         free(target_host);
1236         strbuf_release(&request);
1237         return conn;
1238 }
1239
1240 /*
1241  * Append the appropriate environment variables to `env` and options to
1242  * `args` for running ssh in Git's SSH-tunneled transport.
1243  */
1244 static void push_ssh_options(struct strvec *args, struct strvec *env,
1245                              enum ssh_variant variant, const char *port,
1246                              enum protocol_version version, int flags)
1247 {
1248         if (variant == VARIANT_SSH &&
1249             version > 0) {
1250                 strvec_push(args, "-o");
1251                 strvec_push(args, "SendEnv=" GIT_PROTOCOL_ENVIRONMENT);
1252                 strvec_pushf(env, GIT_PROTOCOL_ENVIRONMENT "=version=%d",
1253                              version);
1254         }
1255
1256         if (flags & CONNECT_IPV4) {
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 -4"));
1262                 case VARIANT_SSH:
1263                 case VARIANT_PLINK:
1264                 case VARIANT_PUTTY:
1265                 case VARIANT_TORTOISEPLINK:
1266                         strvec_push(args, "-4");
1267                 }
1268         } else if (flags & CONNECT_IPV6) {
1269                 switch (variant) {
1270                 case VARIANT_AUTO:
1271                         BUG("VARIANT_AUTO passed to push_ssh_options");
1272                 case VARIANT_SIMPLE:
1273                         die(_("ssh variant 'simple' does not support -6"));
1274                 case VARIANT_SSH:
1275                 case VARIANT_PLINK:
1276                 case VARIANT_PUTTY:
1277                 case VARIANT_TORTOISEPLINK:
1278                         strvec_push(args, "-6");
1279                 }
1280         }
1281
1282         if (variant == VARIANT_TORTOISEPLINK)
1283                 strvec_push(args, "-batch");
1284
1285         if (port) {
1286                 switch (variant) {
1287                 case VARIANT_AUTO:
1288                         BUG("VARIANT_AUTO passed to push_ssh_options");
1289                 case VARIANT_SIMPLE:
1290                         die(_("ssh variant 'simple' does not support setting port"));
1291                 case VARIANT_SSH:
1292                         strvec_push(args, "-p");
1293                         break;
1294                 case VARIANT_PLINK:
1295                 case VARIANT_PUTTY:
1296                 case VARIANT_TORTOISEPLINK:
1297                         strvec_push(args, "-P");
1298                 }
1299
1300                 strvec_push(args, port);
1301         }
1302 }
1303
1304 /* Prepare a child_process for use by Git's SSH-tunneled transport. */
1305 static void fill_ssh_args(struct child_process *conn, const char *ssh_host,
1306                           const char *port, enum protocol_version version,
1307                           int flags)
1308 {
1309         const char *ssh;
1310         enum ssh_variant variant;
1311
1312         if (looks_like_command_line_option(ssh_host))
1313                 die(_("strange hostname '%s' blocked"), ssh_host);
1314
1315         ssh = get_ssh_command();
1316         if (ssh) {
1317                 variant = determine_ssh_variant(ssh, 1);
1318         } else {
1319                 /*
1320                  * GIT_SSH is the no-shell version of
1321                  * GIT_SSH_COMMAND (and must remain so for
1322                  * historical compatibility).
1323                  */
1324                 conn->use_shell = 0;
1325
1326                 ssh = getenv("GIT_SSH");
1327                 if (!ssh)
1328                         ssh = "ssh";
1329                 variant = determine_ssh_variant(ssh, 0);
1330         }
1331
1332         if (variant == VARIANT_AUTO) {
1333                 struct child_process detect = CHILD_PROCESS_INIT;
1334
1335                 detect.use_shell = conn->use_shell;
1336                 detect.no_stdin = detect.no_stdout = detect.no_stderr = 1;
1337
1338                 strvec_push(&detect.args, ssh);
1339                 strvec_push(&detect.args, "-G");
1340                 push_ssh_options(&detect.args, &detect.env,
1341                                  VARIANT_SSH, port, version, flags);
1342                 strvec_push(&detect.args, ssh_host);
1343
1344                 variant = run_command(&detect) ? VARIANT_SIMPLE : VARIANT_SSH;
1345         }
1346
1347         strvec_push(&conn->args, ssh);
1348         push_ssh_options(&conn->args, &conn->env, variant, port, version,
1349                          flags);
1350         strvec_push(&conn->args, ssh_host);
1351 }
1352
1353 /*
1354  * This returns the dummy child_process `no_fork` if the transport protocol
1355  * does not need fork(2), or a struct child_process object if it does.  Once
1356  * done, finish the connection with finish_connect() with the value returned
1357  * from this function (it is safe to call finish_connect() with NULL to
1358  * support the former case).
1359  *
1360  * If it returns, the connect is successful; it just dies on errors (this
1361  * will hopefully be changed in a libification effort, to return NULL when
1362  * the connection failed).
1363  */
1364 struct child_process *git_connect(int fd[2], const char *url,
1365                                   const char *prog, int flags)
1366 {
1367         char *hostandport, *path;
1368         struct child_process *conn;
1369         enum protocol protocol;
1370         enum protocol_version version = get_protocol_version_config();
1371
1372         /*
1373          * NEEDSWORK: If we are trying to use protocol v2 and we are planning
1374          * to perform a push, then fallback to v0 since the client doesn't know
1375          * how to push yet using v2.
1376          */
1377         if (version == protocol_v2 && !strcmp("git-receive-pack", prog))
1378                 version = protocol_v0;
1379
1380         /* Without this we cannot rely on waitpid() to tell
1381          * what happened to our children.
1382          */
1383         signal(SIGCHLD, SIG_DFL);
1384
1385         protocol = parse_connect_url(url, &hostandport, &path);
1386         if ((flags & CONNECT_DIAG_URL) && (protocol != PROTO_SSH)) {
1387                 printf("Diag: url=%s\n", url ? url : "NULL");
1388                 printf("Diag: protocol=%s\n", prot_name(protocol));
1389                 printf("Diag: hostandport=%s\n", hostandport ? hostandport : "NULL");
1390                 printf("Diag: path=%s\n", path ? path : "NULL");
1391                 conn = NULL;
1392         } else if (protocol == PROTO_GIT) {
1393                 conn = git_connect_git(fd, hostandport, path, prog, version, flags);
1394                 conn->trace2_child_class = "transport/git";
1395         } else {
1396                 struct strbuf cmd = STRBUF_INIT;
1397                 const char *const *var;
1398
1399                 conn = xmalloc(sizeof(*conn));
1400                 child_process_init(conn);
1401
1402                 if (looks_like_command_line_option(path))
1403                         die(_("strange pathname '%s' blocked"), path);
1404
1405                 strbuf_addstr(&cmd, prog);
1406                 strbuf_addch(&cmd, ' ');
1407                 sq_quote_buf(&cmd, path);
1408
1409                 /* remove repo-local variables from the environment */
1410                 for (var = local_repo_env; *var; var++)
1411                         strvec_push(&conn->env, *var);
1412
1413                 conn->use_shell = 1;
1414                 conn->in = conn->out = -1;
1415                 if (protocol == PROTO_SSH) {
1416                         char *ssh_host = hostandport;
1417                         const char *port = NULL;
1418                         transport_check_allowed("ssh");
1419                         get_host_and_port(&ssh_host, &port);
1420
1421                         if (!port)
1422                                 port = get_port(ssh_host);
1423
1424                         if (flags & CONNECT_DIAG_URL) {
1425                                 printf("Diag: url=%s\n", url ? url : "NULL");
1426                                 printf("Diag: protocol=%s\n", prot_name(protocol));
1427                                 printf("Diag: userandhost=%s\n", ssh_host ? ssh_host : "NULL");
1428                                 printf("Diag: port=%s\n", port ? port : "NONE");
1429                                 printf("Diag: path=%s\n", path ? path : "NULL");
1430
1431                                 free(hostandport);
1432                                 free(path);
1433                                 free(conn);
1434                                 strbuf_release(&cmd);
1435                                 return NULL;
1436                         }
1437                         conn->trace2_child_class = "transport/ssh";
1438                         fill_ssh_args(conn, ssh_host, port, version, flags);
1439                 } else {
1440                         transport_check_allowed("file");
1441                         conn->trace2_child_class = "transport/file";
1442                         if (version > 0) {
1443                                 strvec_pushf(&conn->env,
1444                                              GIT_PROTOCOL_ENVIRONMENT "=version=%d",
1445                                              version);
1446                         }
1447                 }
1448                 strvec_push(&conn->args, cmd.buf);
1449
1450                 if (start_command(conn))
1451                         die(_("unable to fork"));
1452
1453                 fd[0] = conn->out; /* read from child's stdout */
1454                 fd[1] = conn->in;  /* write to child's stdin */
1455                 strbuf_release(&cmd);
1456         }
1457         free(hostandport);
1458         free(path);
1459         return conn;
1460 }
1461
1462 int finish_connect(struct child_process *conn)
1463 {
1464         int code;
1465         if (!conn || git_connection_is_socket(conn))
1466                 return 0;
1467
1468         code = finish_command(conn);
1469         free(conn);
1470         return code;
1471 }