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