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