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 *, int *);
  22 static const char *next_server_feature_value(const char *feature, int *len, int *offset);
  23
  24 static int check_ref(const char *name, unsigned int flags)
  25 {
  26         if (!flags)
  27                 return 1;
  28
  29         if (!skip_prefix(name, "refs/", &name))
  30                 return 0;
  31
  32         /* REF_NORMAL means that we don't want the magic fake tag refs */
  33         if ((flags & REF_NORMAL) && check_refname_format(name, 0))
  34                 return 0;
  35
  36         /* REF_HEADS means that we want regular branch heads */
  37         if ((flags & REF_HEADS) && starts_with(name, "heads/"))
  38                 return 1;
  39
  40         /* REF_TAGS means that we want tags */
  41         if ((flags & REF_TAGS) && starts_with(name, "tags/"))
  42                 return 1;
  43
  44         /* All type bits clear means that we are ok with anything */
  45         return !(flags & ~REF_NORMAL);
  46 }
  47
  48 int check_ref_type(const struct ref *ref, int flags)
  49 {
  50         return check_ref(ref->name, flags);
  51 }
  52
  53 static NORETURN void die_initial_contact(int unexpected)
  54 {
  55         /*
  56          * A hang-up after seeing some response from the other end
  57          * means that it is unexpected, as we know the other end is
  58          * willing to talk to us.  A hang-up before seeing any
  59          * response does not necessarily mean an ACL problem, though.
  60          */
  61         if (unexpected)
  62                 die(_("the remote end hung up upon initial contact"));
  63         else
  64                 die(_("Could not read from remote repository.\n\n"
  65                       "Please make sure you have the correct access rights\n"
  66                       "and the repository exists."));
  67 }
  68
  69 /* Checks if the server supports the capability 'c' */
  70 int server_supports_v2(const char *c, int die_on_error)
  71 {
  72         int i;
  73
  74         for (i = 0; i < server_capabilities_v2.argc; i++) {
  75                 const char *out;
  76                 if (skip_prefix(server_capabilities_v2.argv[i], c, &out) &&
  77                     (!*out || *out == '='))
  78                         return 1;
  79         }
  80
  81         if (die_on_error)
  82                 die(_("server doesn't support '%s'"), c);
  83
  84         return 0;
  85 }
  86
  87 int server_feature_v2(const char *c, const char **v)
  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 == '=')) {
  95                         *v = out + 1;
  96                         return 1;
  97                 }
  98         }
  99         return 0;
 100 }
 101
 102 int server_supports_feature(const char *c, const char *feature,
 103                             int die_on_error)
 104 {
 105         int i;
 106
 107         for (i = 0; i < server_capabilities_v2.argc; i++) {
 108                 const char *out;
 109                 if (skip_prefix(server_capabilities_v2.argv[i], c, &out) &&
 110                     (!*out || *(out++) == '=')) {
 111                         if (parse_feature_request(out, feature))
 112                                 return 1;
 113                         else
 114                                 break;
 115                 }
 116         }
 117
 118         if (die_on_error)
 119                 die(_("server doesn't support feature '%s'"), feature);
 120
 121         return 0;
 122 }
 123
 124 static void process_capabilities_v2(struct packet_reader *reader)
 125 {
 126         while (packet_reader_read(reader) == PACKET_READ_NORMAL)
 127                 argv_array_push(&server_capabilities_v2, reader->line);
 128
 129         if (reader->status != PACKET_READ_FLUSH)
 130                 die(_("expected flush after capabilities"));
 131 }
 132
 133 enum protocol_version discover_version(struct packet_reader *reader)
 134 {
 135         enum protocol_version version = protocol_unknown_version;
 136
 137         /*
 138          * Peek the first line of the server's response to
 139          * determine the protocol version the server is speaking.
 140          */
 141         switch (packet_reader_peek(reader)) {
 142         case PACKET_READ_EOF:
 143                 die_initial_contact(0);
 144         case PACKET_READ_FLUSH:
 145         case PACKET_READ_DELIM:
 146                 version = protocol_v0;
 147                 break;
 148         case PACKET_READ_NORMAL:
 149                 version = determine_protocol_version_client(reader->line);
 150                 break;
 151         }
 152
 153         switch (version) {
 154         case protocol_v2:
 155                 process_capabilities_v2(reader);
 156                 break;
 157         case protocol_v1:
 158                 /* Read the peeked version line */
 159                 packet_reader_read(reader);
 160                 break;
 161         case protocol_v0:
 162                 break;
 163         case protocol_unknown_version:
 164                 BUG("unknown protocol version");
 165         }
 166
 167         return version;
 168 }
 169
 170 static void parse_one_symref_info(struct string_list *symref, const char *val, int len)
 171 {
 172         char *sym, *target;
 173         struct string_list_item *item;
 174
 175         if (!len)
 176                 return; /* just "symref" */
 177         /* e.g. "symref=HEAD:refs/heads/master" */
 178         sym = xmemdupz(val, len);
 179         target = strchr(sym, ':');
 180         if (!target)
 181                 /* just "symref=something" */
 182                 goto reject;
 183         *(target++) = '\0';
 184         if (check_refname_format(sym, REFNAME_ALLOW_ONELEVEL) ||
 185             check_refname_format(target, REFNAME_ALLOW_ONELEVEL))
 186                 /* "symref=bogus:pair */
 187                 goto reject;
 188         item = string_list_append_nodup(symref, sym);
 189         item->util = target;
 190         return;
 191 reject:
 192         free(sym);
 193         return;
 194 }
 195
 196 static void annotate_refs_with_symref_info(struct ref *ref)
 197 {
 198         struct string_list symref = STRING_LIST_INIT_DUP;
 199         int offset = 0;
 200
 201         while (1) {
 202                 int len;
 203                 const char *val;
 204
 205                 val = next_server_feature_value("symref", &len, &offset);
 206                 if (!val)
 207                         break;
 208                 parse_one_symref_info(&symref, val, len);
 209         }
 210         string_list_sort(&symref);
 211
 212         for (; ref; ref = ref->next) {
 213                 struct string_list_item *item;
 214                 item = string_list_lookup(&symref, ref->name);
 215                 if (!item)
 216                         continue;
 217                 ref->symref = xstrdup((char *)item->util);
 218         }
 219         string_list_clear(&symref, 0);
 220 }
 221
 222 static void process_capabilities(struct packet_reader *reader, int *linelen)
 223 {
 224         const char *line = reader->line;
 225         int nul_location = strlen(line);
 226         if (nul_location == *linelen)
 227                 return;
 228         server_capabilities_v1 = xstrdup(line + nul_location + 1);
 229         *linelen = nul_location;
 230 }
 231
 232 static int process_dummy_ref(const struct packet_reader *reader)
 233 {
 234         const char *line = reader->line;
 235         struct object_id oid;
 236         const char *name;
 237
 238         if (parse_oid_hex(line, &oid, &name))
 239                 return 0;
 240         if (*name != ' ')
 241                 return 0;
 242         name++;
 243
 244         return oideq(&null_oid, &oid) && !strcmp(name, "capabilities^{}");
 245 }
 246
 247 static void check_no_capabilities(const char *line, int len)
 248 {
 249         if (strlen(line) != len)
 250                 warning(_("ignoring capabilities after first line '%s'"),
 251                         line + strlen(line));
 252 }
 253
 254 static int process_ref(const struct packet_reader *reader, int len,
 255                        struct ref ***list, unsigned int flags,
 256                        struct oid_array *extra_have)
 257 {
 258         const char *line = reader->line;
 259         struct object_id old_oid;
 260         const char *name;
 261
 262         if (parse_oid_hex(line, &old_oid, &name))
 263                 return 0;
 264         if (*name != ' ')
 265                 return 0;
 266         name++;
 267
 268         if (extra_have && !strcmp(name, ".have")) {
 269                 oid_array_append(extra_have, &old_oid);
 270         } else if (!strcmp(name, "capabilities^{}")) {
 271                 die(_("protocol error: unexpected capabilities^{}"));
 272         } else if (check_ref(name, flags)) {
 273                 struct ref *ref = alloc_ref(name);
 274                 oidcpy(&ref->old_oid, &old_oid);
 275                 **list = ref;
 276                 *list = &ref->next;
 277         }
 278         check_no_capabilities(line, len);
 279         return 1;
 280 }
 281
 282 static int process_shallow(const struct packet_reader *reader, int len,
 283                            struct oid_array *shallow_points)
 284 {
 285         const char *line = reader->line;
 286         const char *arg;
 287         struct object_id old_oid;
 288
 289         if (!skip_prefix(line, "shallow ", &arg))
 290                 return 0;
 291
 292         if (get_oid_hex(arg, &old_oid))
 293                 die(_("protocol error: expected shallow sha-1, got '%s'"), arg);
 294         if (!shallow_points)
 295                 die(_("repository on the other end cannot be shallow"));
 296         oid_array_append(shallow_points, &old_oid);
 297         check_no_capabilities(line, len);
 298         return 1;
 299 }
 300
 301 enum get_remote_heads_state {
 302         EXPECTING_FIRST_REF = 0,
 303         EXPECTING_REF,
 304         EXPECTING_SHALLOW,
 305         EXPECTING_DONE,
 306 };
 307
 308 /*
 309  * Read all the refs from the other end
 310  */
 311 struct ref **get_remote_heads(struct packet_reader *reader,
 312                               struct ref **list, unsigned int flags,
 313                               struct oid_array *extra_have,
 314                               struct oid_array *shallow_points)
 315 {
 316         struct ref **orig_list = list;
 317         int len = 0;
 318         enum get_remote_heads_state state = EXPECTING_FIRST_REF;
 319
 320         *list = NULL;
 321
 322         while (state != EXPECTING_DONE) {
 323                 switch (packet_reader_read(reader)) {
 324                 case PACKET_READ_EOF:
 325                         die_initial_contact(1);
 326                 case PACKET_READ_NORMAL:
 327                         len = reader->pktlen;
 328                         break;
 329                 case PACKET_READ_FLUSH:
 330                         state = EXPECTING_DONE;
 331                         break;
 332                 case PACKET_READ_DELIM:
 333                         die(_("invalid packet"));
 334                 }
 335
 336                 switch (state) {
 337                 case EXPECTING_FIRST_REF:
 338                         process_capabilities(reader, &len);
 339                         if (process_dummy_ref(reader)) {
 340                                 state = EXPECTING_SHALLOW;
 341                                 break;
 342                         }
 343                         state = EXPECTING_REF;
 344                         /* fallthrough */
 345                 case EXPECTING_REF:
 346                         if (process_ref(reader, len, &list, flags, extra_have))
 347                                 break;
 348                         state = EXPECTING_SHALLOW;
 349                         /* fallthrough */
 350                 case EXPECTING_SHALLOW:
 351                         if (process_shallow(reader, len, shallow_points))
 352                                 break;
 353                         die(_("protocol error: unexpected '%s'"), reader->line);
 354                 case EXPECTING_DONE:
 355                         break;
 356                 }
 357         }
 358
 359         annotate_refs_with_symref_info(*orig_list);
 360
 361         return list;
 362 }
 363
 364 /* Returns 1 when a valid ref has been added to `list`, 0 otherwise */
 365 static int process_ref_v2(const char *line, struct ref ***list)
 366 {
 367         int ret = 1;
 368         int i = 0;
 369         struct object_id old_oid;
 370         struct ref *ref;
 371         struct string_list line_sections = STRING_LIST_INIT_DUP;
 372         const char *end;
 373
 374         /*
 375          * Ref lines have a number of fields which are space deliminated.  The
 376          * first field is the OID of the ref.  The second field is the ref
 377          * name.  Subsequent fields (symref-target and peeled) are optional and
 378          * don't have a particular order.
 379          */
 380         if (string_list_split(&line_sections, line, ' ', -1) < 2) {
 381                 ret = 0;
 382                 goto out;
 383         }
 384
 385         if (parse_oid_hex(line_sections.items[i++].string, &old_oid, &end) ||
 386             *end) {
 387                 ret = 0;
 388                 goto out;
 389         }
 390
 391         ref = alloc_ref(line_sections.items[i++].string);
 392
 393         oidcpy(&ref->old_oid, &old_oid);
 394         **list = ref;
 395         *list = &ref->next;
 396
 397         for (; i < line_sections.nr; i++) {
 398                 const char *arg = line_sections.items[i].string;
 399                 if (skip_prefix(arg, "symref-target:", &arg))
 400                         ref->symref = xstrdup(arg);
 401
 402                 if (skip_prefix(arg, "peeled:", &arg)) {
 403                         struct object_id peeled_oid;
 404                         char *peeled_name;
 405                         struct ref *peeled;
 406                         if (parse_oid_hex(arg, &peeled_oid, &end) || *end) {
 407                                 ret = 0;
 408                                 goto out;
 409                         }
 410
 411                         peeled_name = xstrfmt("%s^{}", ref->name);
 412                         peeled = alloc_ref(peeled_name);
 413
 414                         oidcpy(&peeled->old_oid, &peeled_oid);
 415                         **list = peeled;
 416                         *list = &peeled->next;
 417
 418                         free(peeled_name);
 419                 }
 420         }
 421
 422 out:
 423         string_list_clear(&line_sections, 0);
 424         return ret;
 425 }
 426
 427 struct ref **get_remote_refs(int fd_out, struct packet_reader *reader,
 428                              struct ref **list, int for_push,
 429                              const struct argv_array *ref_prefixes,
 430                              const struct string_list *server_options)
 431 {
 432         int i;
 433         *list = NULL;
 434
 435         if (server_supports_v2("ls-refs", 1))
 436                 packet_write_fmt(fd_out, "command=ls-refs\n");
 437
 438         if (server_supports_v2("agent", 0))
 439                 packet_write_fmt(fd_out, "agent=%s", git_user_agent_sanitized());
 440
 441         if (server_options && server_options->nr &&
 442             server_supports_v2("server-option", 1))
 443                 for (i = 0; i < server_options->nr; i++)
 444                         packet_write_fmt(fd_out, "server-option=%s",
 445                                          server_options->items[i].string);
 446
 447         packet_delim(fd_out);
 448         /* When pushing we don't want to request the peeled tags */
 449         if (!for_push)
 450                 packet_write_fmt(fd_out, "peel\n");
 451         packet_write_fmt(fd_out, "symrefs\n");
 452         for (i = 0; ref_prefixes && i < ref_prefixes->argc; i++) {
 453                 packet_write_fmt(fd_out, "ref-prefix %s\n",
 454                                  ref_prefixes->argv[i]);
 455         }
 456         packet_flush(fd_out);
 457
 458         /* Process response from server */
 459         while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
 460                 if (!process_ref_v2(reader->line, &list))
 461                         die(_("invalid ls-refs response: %s"), reader->line);
 462         }
 463
 464         if (reader->status != PACKET_READ_FLUSH)
 465                 die(_("expected flush after ref listing"));
 466
 467         return list;
 468 }
 469
 470 static const char *parse_feature_value(const char *feature_list, const char *feature, int *lenp, int *offset)
 471 {
 472         int len;
 473
 474         if (!feature_list)
 475                 return NULL;
 476
 477         len = strlen(feature);
 478         if (offset)
 479                 feature_list += *offset;
 480         while (*feature_list) {
 481                 const char *found = strstr(feature_list, feature);
 482                 if (!found)
 483                         return NULL;
 484                 if (feature_list == found || isspace(found[-1])) {
 485                         const char *value = found + len;
 486                         /* feature with no value (e.g., "thin-pack") */
 487                         if (!*value || isspace(*value)) {
 488                                 if (lenp)
 489                                         *lenp = 0;
 490                                 return value;
 491                         }
 492                         /* feature with a value (e.g., "agent=git/1.2.3") */
 493                         else if (*value == '=') {
 494                                 int end;
 495
 496                                 value++;
 497                                 end = strcspn(value, " \t\n");
 498                                 if (lenp)
 499                                         *lenp = end;
 500                                 if (offset)
 501                                         *offset = value + end - feature_list;
 502                                 return value;
 503                         }
 504                         /*
 505                          * otherwise we matched a substring of another feature;
 506                          * keep looking
 507                          */
 508                 }
 509                 feature_list = found + 1;
 510         }
 511         return NULL;
 512 }
 513
 514 int parse_feature_request(const char *feature_list, const char *feature)
 515 {
 516         return !!parse_feature_value(feature_list, feature, NULL, NULL);
 517 }
 518
 519 static const char *next_server_feature_value(const char *feature, int *len, int *offset)
 520 {
 521         return parse_feature_value(server_capabilities_v1, feature, len, offset);
 522 }
 523
 524 const char *server_feature_value(const char *feature, int *len)
 525 {
 526         return parse_feature_value(server_capabilities_v1, feature, len, NULL);
 527 }
 528
 529 int server_supports(const char *feature)
 530 {
 531         return !!server_feature_value(feature, NULL);
 532 }
 533
 534 enum protocol {
 535         PROTO_LOCAL = 1,
 536         PROTO_FILE,
 537         PROTO_SSH,
 538         PROTO_GIT
 539 };
 540
 541 int url_is_local_not_ssh(const char *url)
 542 {
 543         const char *colon = strchr(url, ':');
 544         const char *slash = strchr(url, '/');
 545         return !colon || (slash && slash < colon) ||
 546                 (has_dos_drive_prefix(url) && is_valid_path(url));
 547 }
 548
 549 static const char *prot_name(enum protocol protocol)
 550 {
 551         switch (protocol) {
 552                 case PROTO_LOCAL:
 553                 case PROTO_FILE:
 554                         return "file";
 555                 case PROTO_SSH:
 556                         return "ssh";
 557                 case PROTO_GIT:
 558                         return "git";
 559                 default:
 560                         return "unknown protocol";
 561         }
 562 }
 563
 564 static enum protocol get_protocol(const char *name)
 565 {
 566         if (!strcmp(name, "ssh"))
 567                 return PROTO_SSH;
 568         if (!strcmp(name, "git"))
 569                 return PROTO_GIT;
 570         if (!strcmp(name, "git+ssh")) /* deprecated - do not use */
 571                 return PROTO_SSH;
 572         if (!strcmp(name, "ssh+git")) /* deprecated - do not use */
 573                 return PROTO_SSH;
 574         if (!strcmp(name, "file"))
 575                 return PROTO_FILE;
 576         die(_("protocol '%s' is not supported"), name);
 577 }
 578
 579 static char *host_end(char **hoststart, int removebrackets)
 580 {
 581         char *host = *hoststart;
 582         char *end;
 583         char *start = strstr(host, "@[");
 584         if (start)
 585                 start++; /* Jump over '@' */
 586         else
 587                 start = host;
 588         if (start[0] == '[') {
 589                 end = strchr(start + 1, ']');
 590                 if (end) {
 591                         if (removebrackets) {
 592                                 *end = 0;
 593                                 memmove(start, start + 1, end - start);
 594                                 end++;
 595                         }
 596                 } else
 597                         end = host;
 598         } else
 599                 end = host;
 600         return end;
 601 }
 602
 603 #define STR_(s) # s
 604 #define STR(s)  STR_(s)
 605
 606 static void get_host_and_port(char **host, const char **port)
 607 {
 608         char *colon, *end;
 609         end = host_end(host, 1);
 610         colon = strchr(end, ':');
 611         if (colon) {
 612                 long portnr = strtol(colon + 1, &end, 10);
 613                 if (end != colon + 1 && *end == '\0' && 0 <= portnr && portnr < 65536) {
 614                         *colon = 0;
 615                         *port = colon + 1;
 616                 } else if (!colon[1]) {
 617                         *colon = 0;
 618                 }
 619         }
 620 }
 621
 622 static void enable_keepalive(int sockfd)
 623 {
 624         int ka = 1;
 625
 626         if (setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, &ka, sizeof(ka)) < 0)
 627                 error_errno(_("unable to set SO_KEEPALIVE on socket"));
 628 }
 629
 630 #ifndef NO_IPV6
 631
 632 static const char *ai_name(const struct addrinfo *ai)
 633 {
 634         static char addr[NI_MAXHOST];
 635         if (getnameinfo(ai->ai_addr, ai->ai_addrlen, addr, sizeof(addr), NULL, 0,
 636                         NI_NUMERICHOST) != 0)
 637                 xsnprintf(addr, sizeof(addr), "(unknown)");
 638
 639         return addr;
 640 }
 641
 642 /*
 643  * Returns a connected socket() fd, or else die()s.
 644  */
 645 static int git_tcp_connect_sock(char *host, int flags)
 646 {
 647         struct strbuf error_message = STRBUF_INIT;
 648         int sockfd = -1;
 649         const char *port = STR(DEFAULT_GIT_PORT);
 650         struct addrinfo hints, *ai0, *ai;
 651         int gai;
 652         int cnt = 0;
 653
 654         get_host_and_port(&host, &port);
 655         if (!*port)
 656                 port = "<none>";
 657
 658         memset(&hints, 0, sizeof(hints));
 659         if (flags & CONNECT_IPV4)
 660                 hints.ai_family = AF_INET;
 661         else if (flags & CONNECT_IPV6)
 662                 hints.ai_family = AF_INET6;
 663         hints.ai_socktype = SOCK_STREAM;
 664         hints.ai_protocol = IPPROTO_TCP;
 665
 666         if (flags & CONNECT_VERBOSE)
 667                 fprintf(stderr, _("Looking up %s ... "), host);
 668
 669         gai = getaddrinfo(host, port, &hints, &ai);
 670         if (gai)
 671                 die(_("unable to look up %s (port %s) (%s)"), host, port, gai_strerror(gai));
 672
 673         if (flags & CONNECT_VERBOSE)
 674                 /* TRANSLATORS: this is the end of "Looking up %s ... " */
 675                 fprintf(stderr, _("done.\nConnecting to %s (port %s) ... "), host, port);
 676
 677         for (ai0 = ai; ai; ai = ai->ai_next, cnt++) {
 678                 sockfd = socket(ai->ai_family,
 679                                 ai->ai_socktype, ai->ai_protocol);
 680                 if ((sockfd < 0) ||
 681                     (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0)) {
 682                         strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 683                                     host, cnt, ai_name(ai), strerror(errno));
 684                         if (0 <= sockfd)
 685                                 close(sockfd);
 686                         sockfd = -1;
 687                         continue;
 688                 }
 689                 if (flags & CONNECT_VERBOSE)
 690                         fprintf(stderr, "%s ", ai_name(ai));
 691                 break;
 692         }
 693
 694         freeaddrinfo(ai0);
 695
 696         if (sockfd < 0)
 697                 die(_("unable to connect to %s:\n%s"), host, error_message.buf);
 698
 699         enable_keepalive(sockfd);
 700
 701         if (flags & CONNECT_VERBOSE)
 702                 /* TRANSLATORS: this is the end of "Connecting to %s (port %s) ... " */
 703                 fprintf_ln(stderr, _("done."));
 704
 705         strbuf_release(&error_message);
 706
 707         return sockfd;
 708 }
 709
 710 #else /* NO_IPV6 */
 711
 712 /*
 713  * Returns a connected socket() fd, or else die()s.
 714  */
 715 static int git_tcp_connect_sock(char *host, int flags)
 716 {
 717         struct strbuf error_message = STRBUF_INIT;
 718         int sockfd = -1;
 719         const char *port = STR(DEFAULT_GIT_PORT);
 720         char *ep;
 721         struct hostent *he;
 722         struct sockaddr_in sa;
 723         char **ap;
 724         unsigned int nport;
 725         int cnt;
 726
 727         get_host_and_port(&host, &port);
 728
 729         if (flags & CONNECT_VERBOSE)
 730                 fprintf(stderr, _("Looking up %s ... "), host);
 731
 732         he = gethostbyname(host);
 733         if (!he)
 734                 die(_("unable to look up %s (%s)"), host, hstrerror(h_errno));
 735         nport = strtoul(port, &ep, 10);
 736         if ( ep == port || *ep ) {
 737                 /* Not numeric */
 738                 struct servent *se = getservbyname(port,"tcp");
 739                 if ( !se )
 740                         die(_("unknown port %s"), port);
 741                 nport = se->s_port;
 742         }
 743
 744         if (flags & CONNECT_VERBOSE)
 745                 /* TRANSLATORS: this is the end of "Looking up %s ... " */
 746                 fprintf(stderr, _("done.\nConnecting to %s (port %s) ... "), host, port);
 747
 748         for (cnt = 0, ap = he->h_addr_list; *ap; ap++, cnt++) {
 749                 memset(&sa, 0, sizeof sa);
 750                 sa.sin_family = he->h_addrtype;
 751                 sa.sin_port = htons(nport);
 752                 memcpy(&sa.sin_addr, *ap, he->h_length);
 753
 754                 sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 755                 if ((sockfd < 0) ||
 756                     connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 757                         strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 758                                 host,
 759                                 cnt,
 760                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr),
 761                                 strerror(errno));
 762                         if (0 <= sockfd)
 763                                 close(sockfd);
 764                         sockfd = -1;
 765                         continue;
 766                 }
 767                 if (flags & CONNECT_VERBOSE)
 768                         fprintf(stderr, "%s ",
 769                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr));
 770                 break;
 771         }
 772
 773         if (sockfd < 0)
 774                 die(_("unable to connect to %s:\n%s"), host, error_message.buf);
 775
 776         enable_keepalive(sockfd);
 777
 778         if (flags & CONNECT_VERBOSE)
 779                 /* TRANSLATORS: this is the end of "Connecting to %s (port %s) ... " */
 780                 fprintf_ln(stderr, _("done."));
 781
 782         return sockfd;
 783 }
 784
 785 #endif /* NO_IPV6 */
 786
 787
 788 /*
 789  * Dummy child_process returned by git_connect() if the transport protocol
 790  * does not need fork(2).
 791  */
 792 static struct child_process no_fork = CHILD_PROCESS_INIT;
 793
 794 int git_connection_is_socket(struct child_process *conn)
 795 {
 796         return conn == &no_fork;
 797 }
 798
 799 static struct child_process *git_tcp_connect(int fd[2], char *host, int flags)
 800 {
 801         int sockfd = git_tcp_connect_sock(host, flags);
 802
 803         fd[0] = sockfd;
 804         fd[1] = dup(sockfd);
 805
 806         return &no_fork;
 807 }
 808
 809
 810 static char *git_proxy_command;
 811
 812 static int git_proxy_command_options(const char *var, const char *value,
 813                 void *cb)
 814 {
 815         if (!strcmp(var, "core.gitproxy")) {
 816                 const char *for_pos;
 817                 int matchlen = -1;
 818                 int hostlen;
 819                 const char *rhost_name = cb;
 820                 int rhost_len = strlen(rhost_name);
 821
 822                 if (git_proxy_command)
 823                         return 0;
 824                 if (!value)
 825                         return config_error_nonbool(var);
 826                 /* [core]
 827                  * ;# matches www.kernel.org as well
 828                  * gitproxy = netcatter-1 for kernel.org
 829                  * gitproxy = netcatter-2 for sample.xz
 830                  * gitproxy = netcatter-default
 831                  */
 832                 for_pos = strstr(value, " for ");
 833                 if (!for_pos)
 834                         /* matches everybody */
 835                         matchlen = strlen(value);
 836                 else {
 837                         hostlen = strlen(for_pos + 5);
 838                         if (rhost_len < hostlen)
 839                                 matchlen = -1;
 840                         else if (!strncmp(for_pos + 5,
 841                                           rhost_name + rhost_len - hostlen,
 842                                           hostlen) &&
 843                                  ((rhost_len == hostlen) ||
 844                                   rhost_name[rhost_len - hostlen -1] == '.'))
 845                                 matchlen = for_pos - value;
 846                         else
 847                                 matchlen = -1;
 848                 }
 849                 if (0 <= matchlen) {
 850                         /* core.gitproxy = none for kernel.org */
 851                         if (matchlen == 4 &&
 852                             !memcmp(value, "none", 4))
 853                                 matchlen = 0;
 854                         git_proxy_command = xmemdupz(value, matchlen);
 855                 }
 856                 return 0;
 857         }
 858
 859         return git_default_config(var, value, cb);
 860 }
 861
 862 static int git_use_proxy(const char *host)
 863 {
 864         git_proxy_command = getenv("GIT_PROXY_COMMAND");
 865         git_config(git_proxy_command_options, (void*)host);
 866         return (git_proxy_command && *git_proxy_command);
 867 }
 868
 869 static struct child_process *git_proxy_connect(int fd[2], char *host)
 870 {
 871         const char *port = STR(DEFAULT_GIT_PORT);
 872         struct child_process *proxy;
 873
 874         get_host_and_port(&host, &port);
 875
 876         if (looks_like_command_line_option(host))
 877                 die(_("strange hostname '%s' blocked"), host);
 878         if (looks_like_command_line_option(port))
 879                 die(_("strange port '%s' blocked"), port);
 880
 881         proxy = xmalloc(sizeof(*proxy));
 882         child_process_init(proxy);
 883         argv_array_push(&proxy->args, git_proxy_command);
 884         argv_array_push(&proxy->args, host);
 885         argv_array_push(&proxy->args, port);
 886         proxy->in = -1;
 887         proxy->out = -1;
 888         if (start_command(proxy))
 889                 die(_("cannot start proxy %s"), git_proxy_command);
 890         fd[0] = proxy->out; /* read from proxy stdout */
 891         fd[1] = proxy->in;  /* write to proxy stdin */
 892         return proxy;
 893 }
 894
 895 static char *get_port(char *host)
 896 {
 897         char *end;
 898         char *p = strchr(host, ':');
 899
 900         if (p) {
 901                 long port = strtol(p + 1, &end, 10);
 902                 if (end != p + 1 && *end == '\0' && 0 <= port && port < 65536) {
 903                         *p = '\0';
 904                         return p+1;
 905                 }
 906         }
 907
 908         return NULL;
 909 }
 910
 911 /*
 912  * Extract protocol and relevant parts from the specified connection URL.
 913  * The caller must free() the returned strings.
 914  */
 915 static enum protocol parse_connect_url(const char *url_orig, char **ret_host,
 916                                        char **ret_path)
 917 {
 918         char *url;
 919         char *host, *path;
 920         char *end;
 921         int separator = '/';
 922         enum protocol protocol = PROTO_LOCAL;
 923
 924         if (is_url(url_orig))
 925                 url = url_decode(url_orig);
 926         else
 927                 url = xstrdup(url_orig);
 928
 929         host = strstr(url, "://");
 930         if (host) {
 931                 *host = '\0';
 932                 protocol = get_protocol(url);
 933                 host += 3;
 934         } else {
 935                 host = url;
 936                 if (!url_is_local_not_ssh(url)) {
 937                         protocol = PROTO_SSH;
 938                         separator = ':';
 939                 }
 940         }
 941
 942         /*
 943          * Don't do destructive transforms as protocol code does
 944          * '[]' unwrapping in get_host_and_port()
 945          */
 946         end = host_end(&host, 0);
 947
 948         if (protocol == PROTO_LOCAL)
 949                 path = end;
 950         else if (protocol == PROTO_FILE && *host != '/' &&
 951                  !has_dos_drive_prefix(host) &&
 952                  offset_1st_component(host - 2) > 1)
 953                 path = host - 2; /* include the leading "//" */
 954         else if (protocol == PROTO_FILE && has_dos_drive_prefix(end))
 955                 path = end; /* "file://$(pwd)" may be "file://C:/projects/repo" */
 956         else
 957                 path = strchr(end, separator);
 958
 959         if (!path || !*path)
 960                 die(_("no path specified; see 'git help pull' for valid url syntax"));
 961
 962         /*
 963          * null-terminate hostname and point path to ~ for URL's like this:
 964          *    ssh://host.xz/~user/repo
 965          */
 966
 967         end = path; /* Need to \0 terminate host here */
 968         if (separator == ':')
 969                 path++; /* path starts after ':' */
 970         if (protocol == PROTO_GIT || protocol == PROTO_SSH) {
 971                 if (path[1] == '~')
 972                         path++;
 973         }
 974
 975         path = xstrdup(path);
 976         *end = '\0';
 977
 978         *ret_host = xstrdup(host);
 979         *ret_path = path;
 980         free(url);
 981         return protocol;
 982 }
 983
 984 static const char *get_ssh_command(void)
 985 {
 986         const char *ssh;
 987
 988         if ((ssh = getenv("GIT_SSH_COMMAND")))
 989                 return ssh;
 990
 991         if (!git_config_get_string_const("core.sshcommand", &ssh))
 992                 return ssh;
 993
 994         return NULL;
 995 }
 996
 997 enum ssh_variant {
 998         VARIANT_AUTO,
 999         VARIANT_SIMPLE,
1000         VARIANT_SSH,
1001         VARIANT_PLINK,
1002         VARIANT_PUTTY,
1003         VARIANT_TORTOISEPLINK,
1004 };
1005
1006 static void override_ssh_variant(enum ssh_variant *ssh_variant)
1007 {
1008         const char *variant = getenv("GIT_SSH_VARIANT");
1009
1010         if (!variant && git_config_get_string_const("ssh.variant", &variant))
1011                 return;
1012
1013         if (!strcmp(variant, "auto"))
1014                 *ssh_variant = VARIANT_AUTO;
1015         else if (!strcmp(variant, "plink"))
1016                 *ssh_variant = VARIANT_PLINK;
1017         else if (!strcmp(variant, "putty"))
1018                 *ssh_variant = VARIANT_PUTTY;
1019         else if (!strcmp(variant, "tortoiseplink"))
1020                 *ssh_variant = VARIANT_TORTOISEPLINK;
1021         else if (!strcmp(variant, "simple"))
1022                 *ssh_variant = VARIANT_SIMPLE;
1023         else
1024                 *ssh_variant = VARIANT_SSH;
1025 }
1026
1027 static enum ssh_variant determine_ssh_variant(const char *ssh_command,
1028                                               int is_cmdline)
1029 {
1030         enum ssh_variant ssh_variant = VARIANT_AUTO;
1031         const char *variant;
1032         char *p = NULL;
1033
1034         override_ssh_variant(&ssh_variant);
1035
1036         if (ssh_variant != VARIANT_AUTO)
1037                 return ssh_variant;
1038
1039         if (!is_cmdline) {
1040                 p = xstrdup(ssh_command);
1041                 variant = basename(p);
1042         } else {
1043                 const char **ssh_argv;
1044
1045                 p = xstrdup(ssh_command);
1046                 if (split_cmdline(p, &ssh_argv) > 0) {
1047                         variant = basename((char *)ssh_argv[0]);
1048                         /*
1049                          * At this point, variant points into the buffer
1050                          * referenced by p, hence we do not need ssh_argv
1051                          * any longer.
1052                          */
1053                         free(ssh_argv);
1054                 } else {
1055                         free(p);
1056                         return ssh_variant;
1057                 }
1058         }
1059
1060         if (!strcasecmp(variant, "ssh") ||
1061             !strcasecmp(variant, "ssh.exe"))
1062                 ssh_variant = VARIANT_SSH;
1063         else if (!strcasecmp(variant, "plink") ||
1064                  !strcasecmp(variant, "plink.exe"))
1065                 ssh_variant = VARIANT_PLINK;
1066         else if (!strcasecmp(variant, "tortoiseplink") ||
1067                  !strcasecmp(variant, "tortoiseplink.exe"))
1068                 ssh_variant = VARIANT_TORTOISEPLINK;
1069
1070         free(p);
1071         return ssh_variant;
1072 }
1073
1074 /*
1075  * Open a connection using Git's native protocol.
1076  *
1077  * The caller is responsible for freeing hostandport, but this function may
1078  * modify it (for example, to truncate it to remove the port part).
1079  */
1080 static struct child_process *git_connect_git(int fd[2], char *hostandport,
1081                                              const char *path, const char *prog,
1082                                              enum protocol_version version,
1083                                              int flags)
1084 {
1085         struct child_process *conn;
1086         struct strbuf request = STRBUF_INIT;
1087         /*
1088          * Set up virtual host information based on where we will
1089          * connect, unless the user has overridden us in
1090          * the environment.
1091          */
1092         char *target_host = getenv("GIT_OVERRIDE_VIRTUAL_HOST");
1093         if (target_host)
1094                 target_host = xstrdup(target_host);
1095         else
1096                 target_host = xstrdup(hostandport);
1097
1098         transport_check_allowed("git");
1099
1100         /*
1101          * These underlying connection commands die() if they
1102          * cannot connect.
1103          */
1104         if (git_use_proxy(hostandport))
1105                 conn = git_proxy_connect(fd, hostandport);
1106         else
1107                 conn = git_tcp_connect(fd, hostandport, flags);
1108         /*
1109          * Separate original protocol components prog and path
1110          * from extended host header with a NUL byte.
1111          *
1112          * Note: Do not add any other headers here!  Doing so
1113          * will cause older git-daemon servers to crash.
1114          */
1115         strbuf_addf(&request,
1116                     "%s %s%chost=%s%c",
1117                     prog, path, 0,
1118                     target_host, 0);
1119
1120         /* If using a new version put that stuff here after a second null byte */
1121         if (version > 0) {
1122                 strbuf_addch(&request, '\0');
1123                 strbuf_addf(&request, "version=%d%c",
1124                             version, '\0');
1125         }
1126
1127         packet_write(fd[1], request.buf, request.len);
1128
1129         free(target_host);
1130         strbuf_release(&request);
1131         return conn;
1132 }
1133
1134 /*
1135  * Append the appropriate environment variables to `env` and options to
1136  * `args` for running ssh in Git's SSH-tunneled transport.
1137  */
1138 static void push_ssh_options(struct argv_array *args, struct argv_array *env,
1139                              enum ssh_variant variant, const char *port,
1140                              enum protocol_version version, int flags)
1141 {
1142         if (variant == VARIANT_SSH &&
1143             version > 0) {
1144                 argv_array_push(args, "-o");
1145                 argv_array_push(args, "SendEnv=" GIT_PROTOCOL_ENVIRONMENT);
1146                 argv_array_pushf(env, GIT_PROTOCOL_ENVIRONMENT "=version=%d",
1147                                  version);
1148         }
1149
1150         if (flags & CONNECT_IPV4) {
1151                 switch (variant) {
1152                 case VARIANT_AUTO:
1153                         BUG("VARIANT_AUTO passed to push_ssh_options");
1154                 case VARIANT_SIMPLE:
1155                         die(_("ssh variant 'simple' does not support -4"));
1156                 case VARIANT_SSH:
1157                 case VARIANT_PLINK:
1158                 case VARIANT_PUTTY:
1159                 case VARIANT_TORTOISEPLINK:
1160                         argv_array_push(args, "-4");
1161                 }
1162         } else if (flags & CONNECT_IPV6) {
1163                 switch (variant) {
1164                 case VARIANT_AUTO:
1165                         BUG("VARIANT_AUTO passed to push_ssh_options");
1166                 case VARIANT_SIMPLE:
1167                         die(_("ssh variant 'simple' does not support -6"));
1168                 case VARIANT_SSH:
1169                 case VARIANT_PLINK:
1170                 case VARIANT_PUTTY:
1171                 case VARIANT_TORTOISEPLINK:
1172                         argv_array_push(args, "-6");
1173                 }
1174         }
1175
1176         if (variant == VARIANT_TORTOISEPLINK)
1177                 argv_array_push(args, "-batch");
1178
1179         if (port) {
1180                 switch (variant) {
1181                 case VARIANT_AUTO:
1182                         BUG("VARIANT_AUTO passed to push_ssh_options");
1183                 case VARIANT_SIMPLE:
1184                         die(_("ssh variant 'simple' does not support setting port"));
1185                 case VARIANT_SSH:
1186                         argv_array_push(args, "-p");
1187                         break;
1188                 case VARIANT_PLINK:
1189                 case VARIANT_PUTTY:
1190                 case VARIANT_TORTOISEPLINK:
1191                         argv_array_push(args, "-P");
1192                 }
1193
1194                 argv_array_push(args, port);
1195         }
1196 }
1197
1198 /* Prepare a child_process for use by Git's SSH-tunneled transport. */
1199 static void fill_ssh_args(struct child_process *conn, const char *ssh_host,
1200                           const char *port, enum protocol_version version,
1201                           int flags)
1202 {
1203         const char *ssh;
1204         enum ssh_variant variant;
1205
1206         if (looks_like_command_line_option(ssh_host))
1207                 die(_("strange hostname '%s' blocked"), ssh_host);
1208
1209         ssh = get_ssh_command();
1210         if (ssh) {
1211                 variant = determine_ssh_variant(ssh, 1);
1212         } else {
1213                 /*
1214                  * GIT_SSH is the no-shell version of
1215                  * GIT_SSH_COMMAND (and must remain so for
1216                  * historical compatibility).
1217                  */
1218                 conn->use_shell = 0;
1219
1220                 ssh = getenv("GIT_SSH");
1221                 if (!ssh)
1222                         ssh = "ssh";
1223                 variant = determine_ssh_variant(ssh, 0);
1224         }
1225
1226         if (variant == VARIANT_AUTO) {
1227                 struct child_process detect = CHILD_PROCESS_INIT;
1228
1229                 detect.use_shell = conn->use_shell;
1230                 detect.no_stdin = detect.no_stdout = detect.no_stderr = 1;
1231
1232                 argv_array_push(&detect.args, ssh);
1233                 argv_array_push(&detect.args, "-G");
1234                 push_ssh_options(&detect.args, &detect.env_array,
1235                                  VARIANT_SSH, port, version, flags);
1236                 argv_array_push(&detect.args, ssh_host);
1237
1238                 variant = run_command(&detect) ? VARIANT_SIMPLE : VARIANT_SSH;
1239         }
1240
1241         argv_array_push(&conn->args, ssh);
1242         push_ssh_options(&conn->args, &conn->env_array, variant, port, version, flags);
1243         argv_array_push(&conn->args, ssh_host);
1244 }
1245
1246 /*
1247  * This returns the dummy child_process `no_fork` if the transport protocol
1248  * does not need fork(2), or a struct child_process object if it does.  Once
1249  * done, finish the connection with finish_connect() with the value returned
1250  * from this function (it is safe to call finish_connect() with NULL to
1251  * support the former case).
1252  *
1253  * If it returns, the connect is successful; it just dies on errors (this
1254  * will hopefully be changed in a libification effort, to return NULL when
1255  * the connection failed).
1256  */
1257 struct child_process *git_connect(int fd[2], const char *url,
1258                                   const char *prog, int flags)
1259 {
1260         char *hostandport, *path;
1261         struct child_process *conn;
1262         enum protocol protocol;
1263         enum protocol_version version = get_protocol_version_config();
1264
1265         /*
1266          * NEEDSWORK: If we are trying to use protocol v2 and we are planning
1267          * to perform a push, then fallback to v0 since the client doesn't know
1268          * how to push yet using v2.
1269          */
1270         if (version == protocol_v2 && !strcmp("git-receive-pack", prog))
1271                 version = protocol_v0;
1272
1273         /* Without this we cannot rely on waitpid() to tell
1274          * what happened to our children.
1275          */
1276         signal(SIGCHLD, SIG_DFL);
1277
1278         protocol = parse_connect_url(url, &hostandport, &path);
1279         if ((flags & CONNECT_DIAG_URL) && (protocol != PROTO_SSH)) {
1280                 printf("Diag: url=%s\n", url ? url : "NULL");
1281                 printf("Diag: protocol=%s\n", prot_name(protocol));
1282                 printf("Diag: hostandport=%s\n", hostandport ? hostandport : "NULL");
1283                 printf("Diag: path=%s\n", path ? path : "NULL");
1284                 conn = NULL;
1285         } else if (protocol == PROTO_GIT) {
1286                 conn = git_connect_git(fd, hostandport, path, prog, version, flags);
1287                 conn->trace2_child_class = "transport/git";
1288         } else {
1289                 struct strbuf cmd = STRBUF_INIT;
1290                 const char *const *var;
1291
1292                 conn = xmalloc(sizeof(*conn));
1293                 child_process_init(conn);
1294
1295                 if (looks_like_command_line_option(path))
1296                         die(_("strange pathname '%s' blocked"), path);
1297
1298                 strbuf_addstr(&cmd, prog);
1299                 strbuf_addch(&cmd, ' ');
1300                 sq_quote_buf(&cmd, path);
1301
1302                 /* remove repo-local variables from the environment */
1303                 for (var = local_repo_env; *var; var++)
1304                         argv_array_push(&conn->env_array, *var);
1305
1306                 conn->use_shell = 1;
1307                 conn->in = conn->out = -1;
1308                 if (protocol == PROTO_SSH) {
1309                         char *ssh_host = hostandport;
1310                         const char *port = NULL;
1311                         transport_check_allowed("ssh");
1312                         get_host_and_port(&ssh_host, &port);
1313
1314                         if (!port)
1315                                 port = get_port(ssh_host);
1316
1317                         if (flags & CONNECT_DIAG_URL) {
1318                                 printf("Diag: url=%s\n", url ? url : "NULL");
1319                                 printf("Diag: protocol=%s\n", prot_name(protocol));
1320                                 printf("Diag: userandhost=%s\n", ssh_host ? ssh_host : "NULL");
1321                                 printf("Diag: port=%s\n", port ? port : "NONE");
1322                                 printf("Diag: path=%s\n", path ? path : "NULL");
1323
1324                                 free(hostandport);
1325                                 free(path);
1326                                 free(conn);
1327                                 strbuf_release(&cmd);
1328                                 return NULL;
1329                         }
1330                         conn->trace2_child_class = "transport/ssh";
1331                         fill_ssh_args(conn, ssh_host, port, version, flags);
1332                 } else {
1333                         transport_check_allowed("file");
1334                         conn->trace2_child_class = "transport/file";
1335                         if (version > 0) {
1336                                 argv_array_pushf(&conn->env_array, GIT_PROTOCOL_ENVIRONMENT "=version=%d",
1337                                                  version);
1338                         }
1339                 }
1340                 argv_array_push(&conn->args, cmd.buf);
1341
1342                 if (start_command(conn))
1343                         die(_("unable to fork"));
1344
1345                 fd[0] = conn->out; /* read from child's stdout */
1346                 fd[1] = conn->in;  /* write to child's stdin */
1347                 strbuf_release(&cmd);
1348         }
1349         free(hostandport);
1350         free(path);
1351         return conn;
1352 }
1353
1354 int finish_connect(struct child_process *conn)
1355 {
1356         int code;
1357         if (!conn || git_connection_is_socket(conn))
1358                 return 0;
1359
1360         code = finish_command(conn);
1361         free(conn);
1362         return code;
1363 }