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