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 "sha1-array.h"
  13 #include "transport.h"
  14 #include "strbuf.h"
  15 #include "version.h"
  16 #include "protocol.h"
  17
  18 static char *server_capabilities;
  19 static struct argv_array server_capabilities_v2 = ARGV_ARRAY_INIT;
  20 static const char *parse_feature_value(const char *, const char *, int *);
  21
  22 static int check_ref(const char *name, unsigned int flags)
  23 {
  24         if (!flags)
  25                 return 1;
  26
  27         if (!skip_prefix(name, "refs/", &name))
  28                 return 0;
  29
  30         /* REF_NORMAL means that we don't want the magic fake tag refs */
  31         if ((flags & REF_NORMAL) && check_refname_format(name, 0))
  32                 return 0;
  33
  34         /* REF_HEADS means that we want regular branch heads */
  35         if ((flags & REF_HEADS) && starts_with(name, "heads/"))
  36                 return 1;
  37
  38         /* REF_TAGS means that we want tags */
  39         if ((flags & REF_TAGS) && starts_with(name, "tags/"))
  40                 return 1;
  41
  42         /* All type bits clear means that we are ok with anything */
  43         return !(flags & ~REF_NORMAL);
  44 }
  45
  46 int check_ref_type(const struct ref *ref, int flags)
  47 {
  48         return check_ref(ref->name, flags);
  49 }
  50
  51 static void die_initial_contact(int unexpected)
  52 {
  53         /*
  54          * A hang-up after seeing some response from the other end
  55          * means that it is unexpected, as we know the other end is
  56          * willing to talk to us.  A hang-up before seeing any
  57          * response does not necessarily mean an ACL problem, though.
  58          */
  59         if (unexpected)
  60                 die(_("The remote end hung up upon initial contact"));
  61         else
  62                 die(_("Could not read from remote repository.\n\n"
  63                       "Please make sure you have the correct access rights\n"
  64                       "and the repository exists."));
  65 }
  66
  67 /* Checks if the server supports the capability 'c' */
  68 int server_supports_v2(const char *c, int die_on_error)
  69 {
  70         int i;
  71
  72         for (i = 0; i < server_capabilities_v2.argc; i++) {
  73                 const char *out;
  74                 if (skip_prefix(server_capabilities_v2.argv[i], c, &out) &&
  75                     (!*out || *out == '='))
  76                         return 1;
  77         }
  78
  79         if (die_on_error)
  80                 die("server doesn't support '%s'", c);
  81
  82         return 0;
  83 }
  84
  85 static void process_capabilities_v2(struct packet_reader *reader)
  86 {
  87         while (packet_reader_read(reader) == PACKET_READ_NORMAL)
  88                 argv_array_push(&server_capabilities_v2, reader->line);
  89
  90         if (reader->status != PACKET_READ_FLUSH)
  91                 die("protocol error");
  92 }
  93
  94 enum protocol_version discover_version(struct packet_reader *reader)
  95 {
  96         enum protocol_version version = protocol_unknown_version;
  97
  98         /*
  99          * Peek the first line of the server's response to
 100          * determine the protocol version the server is speaking.
 101          */
 102         switch (packet_reader_peek(reader)) {
 103         case PACKET_READ_EOF:
 104                 die_initial_contact(0);
 105         case PACKET_READ_FLUSH:
 106         case PACKET_READ_DELIM:
 107                 version = protocol_v0;
 108                 break;
 109         case PACKET_READ_NORMAL:
 110                 version = determine_protocol_version_client(reader->line);
 111                 break;
 112         }
 113
 114         /* Maybe process capabilities here, at least for v2 */
 115         switch (version) {
 116         case protocol_v2:
 117                 process_capabilities_v2(reader);
 118                 break;
 119         case protocol_v1:
 120                 /* Read the peeked version line */
 121                 packet_reader_read(reader);
 122                 break;
 123         case protocol_v0:
 124                 break;
 125         case protocol_unknown_version:
 126                 die("unknown protocol version: '%s'\n", reader->line);
 127         }
 128
 129         return version;
 130 }
 131
 132 static void parse_one_symref_info(struct string_list *symref, const char *val, int len)
 133 {
 134         char *sym, *target;
 135         struct string_list_item *item;
 136
 137         if (!len)
 138                 return; /* just "symref" */
 139         /* e.g. "symref=HEAD:refs/heads/master" */
 140         sym = xmemdupz(val, len);
 141         target = strchr(sym, ':');
 142         if (!target)
 143                 /* just "symref=something" */
 144                 goto reject;
 145         *(target++) = '\0';
 146         if (check_refname_format(sym, REFNAME_ALLOW_ONELEVEL) ||
 147             check_refname_format(target, REFNAME_ALLOW_ONELEVEL))
 148                 /* "symref=bogus:pair */
 149                 goto reject;
 150         item = string_list_append_nodup(symref, sym);
 151         item->util = target;
 152         return;
 153 reject:
 154         free(sym);
 155         return;
 156 }
 157
 158 static void annotate_refs_with_symref_info(struct ref *ref)
 159 {
 160         struct string_list symref = STRING_LIST_INIT_DUP;
 161         const char *feature_list = server_capabilities;
 162
 163         while (feature_list) {
 164                 int len;
 165                 const char *val;
 166
 167                 val = parse_feature_value(feature_list, "symref", &len);
 168                 if (!val)
 169                         break;
 170                 parse_one_symref_info(&symref, val, len);
 171                 feature_list = val + 1;
 172         }
 173         string_list_sort(&symref);
 174
 175         for (; ref; ref = ref->next) {
 176                 struct string_list_item *item;
 177                 item = string_list_lookup(&symref, ref->name);
 178                 if (!item)
 179                         continue;
 180                 ref->symref = xstrdup((char *)item->util);
 181         }
 182         string_list_clear(&symref, 0);
 183 }
 184
 185 static void process_capabilities(const char *line, int *len)
 186 {
 187         int nul_location = strlen(line);
 188         if (nul_location == *len)
 189                 return;
 190         server_capabilities = xstrdup(line + nul_location + 1);
 191         *len = nul_location;
 192 }
 193
 194 static int process_dummy_ref(const char *line)
 195 {
 196         struct object_id oid;
 197         const char *name;
 198
 199         if (parse_oid_hex(line, &oid, &name))
 200                 return 0;
 201         if (*name != ' ')
 202                 return 0;
 203         name++;
 204
 205         return !oidcmp(&null_oid, &oid) && !strcmp(name, "capabilities^{}");
 206 }
 207
 208 static void check_no_capabilities(const char *line, int len)
 209 {
 210         if (strlen(line) != len)
 211                 warning("Ignoring capabilities after first line '%s'",
 212                         line + strlen(line));
 213 }
 214
 215 static int process_ref(const char *line, int len, struct ref ***list,
 216                        unsigned int flags, struct oid_array *extra_have)
 217 {
 218         struct object_id old_oid;
 219         const char *name;
 220
 221         if (parse_oid_hex(line, &old_oid, &name))
 222                 return 0;
 223         if (*name != ' ')
 224                 return 0;
 225         name++;
 226
 227         if (extra_have && !strcmp(name, ".have")) {
 228                 oid_array_append(extra_have, &old_oid);
 229         } else if (!strcmp(name, "capabilities^{}")) {
 230                 die("protocol error: unexpected capabilities^{}");
 231         } else if (check_ref(name, flags)) {
 232                 struct ref *ref = alloc_ref(name);
 233                 oidcpy(&ref->old_oid, &old_oid);
 234                 **list = ref;
 235                 *list = &ref->next;
 236         }
 237         check_no_capabilities(line, len);
 238         return 1;
 239 }
 240
 241 static int process_shallow(const char *line, int len,
 242                            struct oid_array *shallow_points)
 243 {
 244         const char *arg;
 245         struct object_id old_oid;
 246
 247         if (!skip_prefix(line, "shallow ", &arg))
 248                 return 0;
 249
 250         if (get_oid_hex(arg, &old_oid))
 251                 die("protocol error: expected shallow sha-1, got '%s'", arg);
 252         if (!shallow_points)
 253                 die("repository on the other end cannot be shallow");
 254         oid_array_append(shallow_points, &old_oid);
 255         check_no_capabilities(line, len);
 256         return 1;
 257 }
 258
 259 enum get_remote_heads_state {
 260         EXPECTING_FIRST_REF = 0,
 261         EXPECTING_REF,
 262         EXPECTING_SHALLOW,
 263         EXPECTING_DONE,
 264 };
 265
 266 /*
 267  * Read all the refs from the other end
 268  */
 269 struct ref **get_remote_heads(struct packet_reader *reader,
 270                               struct ref **list, unsigned int flags,
 271                               struct oid_array *extra_have,
 272                               struct oid_array *shallow_points)
 273 {
 274         struct ref **orig_list = list;
 275         int len = 0;
 276         enum get_remote_heads_state state = EXPECTING_FIRST_REF;
 277         const char *arg;
 278
 279         *list = NULL;
 280
 281         while (state != EXPECTING_DONE) {
 282                 switch (packet_reader_read(reader)) {
 283                 case PACKET_READ_EOF:
 284                         die_initial_contact(1);
 285                 case PACKET_READ_NORMAL:
 286                         len = reader->pktlen;
 287                         if (len > 4 && skip_prefix(reader->line, "ERR ", &arg))
 288                                 die("remote error: %s", arg);
 289                         break;
 290                 case PACKET_READ_FLUSH:
 291                         state = EXPECTING_DONE;
 292                         break;
 293                 case PACKET_READ_DELIM:
 294                         die("invalid packet");
 295                 }
 296
 297                 switch (state) {
 298                 case EXPECTING_FIRST_REF:
 299                         process_capabilities(reader->line, &len);
 300                         if (process_dummy_ref(reader->line)) {
 301                                 state = EXPECTING_SHALLOW;
 302                                 break;
 303                         }
 304                         state = EXPECTING_REF;
 305                         /* fallthrough */
 306                 case EXPECTING_REF:
 307                         if (process_ref(reader->line, len, &list, flags, extra_have))
 308                                 break;
 309                         state = EXPECTING_SHALLOW;
 310                         /* fallthrough */
 311                 case EXPECTING_SHALLOW:
 312                         if (process_shallow(reader->line, len, shallow_points))
 313                                 break;
 314                         die("protocol error: unexpected '%s'", reader->line);
 315                 case EXPECTING_DONE:
 316                         break;
 317                 }
 318         }
 319
 320         annotate_refs_with_symref_info(*orig_list);
 321
 322         return list;
 323 }
 324
 325 static int process_ref_v2(const char *line, struct ref ***list)
 326 {
 327         int ret = 1;
 328         int i = 0;
 329         struct object_id old_oid;
 330         struct ref *ref;
 331         struct string_list line_sections = STRING_LIST_INIT_DUP;
 332
 333         if (string_list_split(&line_sections, line, ' ', -1) < 2) {
 334                 ret = 0;
 335                 goto out;
 336         }
 337
 338         if (get_oid_hex(line_sections.items[i++].string, &old_oid)) {
 339                 ret = 0;
 340                 goto out;
 341         }
 342
 343         ref = alloc_ref(line_sections.items[i++].string);
 344
 345         oidcpy(&ref->old_oid, &old_oid);
 346         **list = ref;
 347         *list = &ref->next;
 348
 349         for (; i < line_sections.nr; i++) {
 350                 const char *arg = line_sections.items[i].string;
 351                 if (skip_prefix(arg, "symref-target:", &arg))
 352                         ref->symref = xstrdup(arg);
 353
 354                 if (skip_prefix(arg, "peeled:", &arg)) {
 355                         struct object_id peeled_oid;
 356                         char *peeled_name;
 357                         struct ref *peeled;
 358                         if (get_oid_hex(arg, &peeled_oid)) {
 359                                 ret = 0;
 360                                 goto out;
 361                         }
 362
 363                         peeled_name = xstrfmt("%s^{}", ref->name);
 364                         peeled = alloc_ref(peeled_name);
 365
 366                         oidcpy(&peeled->old_oid, &peeled_oid);
 367                         **list = peeled;
 368                         *list = &peeled->next;
 369
 370                         free(peeled_name);
 371                 }
 372         }
 373
 374 out:
 375         string_list_clear(&line_sections, 0);
 376         return ret;
 377 }
 378
 379 struct ref **get_remote_refs(int fd_out, struct packet_reader *reader,
 380                              struct ref **list, int for_push,
 381                              const struct argv_array *ref_patterns)
 382 {
 383         int i;
 384         *list = NULL;
 385
 386         /* Check that the server supports the ls-refs command */
 387         /* Issue request for ls-refs */
 388         if (server_supports_v2("ls-refs", 1))
 389                 packet_write_fmt(fd_out, "command=ls-refs\n");
 390
 391         if (server_supports_v2("agent", 0))
 392             packet_write_fmt(fd_out, "agent=%s", git_user_agent_sanitized());
 393
 394         packet_delim(fd_out);
 395         /* When pushing we don't want to request the peeled tags */
 396         if (!for_push)
 397                 packet_write_fmt(fd_out, "peel\n");
 398         packet_write_fmt(fd_out, "symrefs\n");
 399         for (i = 0; ref_patterns && i < ref_patterns->argc; i++) {
 400                 packet_write_fmt(fd_out, "ref-pattern %s\n",
 401                                  ref_patterns->argv[i]);
 402         }
 403         packet_flush(fd_out);
 404
 405         /* Process response from server */
 406         while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
 407                 if (!process_ref_v2(reader->line, &list))
 408                         die("invalid ls-refs response: %s", reader->line);
 409         }
 410
 411         if (reader->status != PACKET_READ_FLUSH)
 412                 die("protocol error");
 413
 414         return list;
 415 }
 416
 417 static const char *parse_feature_value(const char *feature_list, const char *feature, int *lenp)
 418 {
 419         int len;
 420
 421         if (!feature_list)
 422                 return NULL;
 423
 424         len = strlen(feature);
 425         while (*feature_list) {
 426                 const char *found = strstr(feature_list, feature);
 427                 if (!found)
 428                         return NULL;
 429                 if (feature_list == found || isspace(found[-1])) {
 430                         const char *value = found + len;
 431                         /* feature with no value (e.g., "thin-pack") */
 432                         if (!*value || isspace(*value)) {
 433                                 if (lenp)
 434                                         *lenp = 0;
 435                                 return value;
 436                         }
 437                         /* feature with a value (e.g., "agent=git/1.2.3") */
 438                         else if (*value == '=') {
 439                                 value++;
 440                                 if (lenp)
 441                                         *lenp = strcspn(value, " \t\n");
 442                                 return value;
 443                         }
 444                         /*
 445                          * otherwise we matched a substring of another feature;
 446                          * keep looking
 447                          */
 448                 }
 449                 feature_list = found + 1;
 450         }
 451         return NULL;
 452 }
 453
 454 int parse_feature_request(const char *feature_list, const char *feature)
 455 {
 456         return !!parse_feature_value(feature_list, feature, NULL);
 457 }
 458
 459 const char *server_feature_value(const char *feature, int *len)
 460 {
 461         return parse_feature_value(server_capabilities, feature, len);
 462 }
 463
 464 int server_supports(const char *feature)
 465 {
 466         return !!server_feature_value(feature, NULL);
 467 }
 468
 469 enum protocol {
 470         PROTO_LOCAL = 1,
 471         PROTO_FILE,
 472         PROTO_SSH,
 473         PROTO_GIT
 474 };
 475
 476 int url_is_local_not_ssh(const char *url)
 477 {
 478         const char *colon = strchr(url, ':');
 479         const char *slash = strchr(url, '/');
 480         return !colon || (slash && slash < colon) ||
 481                 has_dos_drive_prefix(url);
 482 }
 483
 484 static const char *prot_name(enum protocol protocol)
 485 {
 486         switch (protocol) {
 487                 case PROTO_LOCAL:
 488                 case PROTO_FILE:
 489                         return "file";
 490                 case PROTO_SSH:
 491                         return "ssh";
 492                 case PROTO_GIT:
 493                         return "git";
 494                 default:
 495                         return "unknown protocol";
 496         }
 497 }
 498
 499 static enum protocol get_protocol(const char *name)
 500 {
 501         if (!strcmp(name, "ssh"))
 502                 return PROTO_SSH;
 503         if (!strcmp(name, "git"))
 504                 return PROTO_GIT;
 505         if (!strcmp(name, "git+ssh")) /* deprecated - do not use */
 506                 return PROTO_SSH;
 507         if (!strcmp(name, "ssh+git")) /* deprecated - do not use */
 508                 return PROTO_SSH;
 509         if (!strcmp(name, "file"))
 510                 return PROTO_FILE;
 511         die("I don't handle protocol '%s'", name);
 512 }
 513
 514 static char *host_end(char **hoststart, int removebrackets)
 515 {
 516         char *host = *hoststart;
 517         char *end;
 518         char *start = strstr(host, "@[");
 519         if (start)
 520                 start++; /* Jump over '@' */
 521         else
 522                 start = host;
 523         if (start[0] == '[') {
 524                 end = strchr(start + 1, ']');
 525                 if (end) {
 526                         if (removebrackets) {
 527                                 *end = 0;
 528                                 memmove(start, start + 1, end - start);
 529                                 end++;
 530                         }
 531                 } else
 532                         end = host;
 533         } else
 534                 end = host;
 535         return end;
 536 }
 537
 538 #define STR_(s) # s
 539 #define STR(s)  STR_(s)
 540
 541 static void get_host_and_port(char **host, const char **port)
 542 {
 543         char *colon, *end;
 544         end = host_end(host, 1);
 545         colon = strchr(end, ':');
 546         if (colon) {
 547                 long portnr = strtol(colon + 1, &end, 10);
 548                 if (end != colon + 1 && *end == '\0' && 0 <= portnr && portnr < 65536) {
 549                         *colon = 0;
 550                         *port = colon + 1;
 551                 } else if (!colon[1]) {
 552                         *colon = 0;
 553                 }
 554         }
 555 }
 556
 557 static void enable_keepalive(int sockfd)
 558 {
 559         int ka = 1;
 560
 561         if (setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, &ka, sizeof(ka)) < 0)
 562                 fprintf(stderr, "unable to set SO_KEEPALIVE on socket: %s\n",
 563                         strerror(errno));
 564 }
 565
 566 #ifndef NO_IPV6
 567
 568 static const char *ai_name(const struct addrinfo *ai)
 569 {
 570         static char addr[NI_MAXHOST];
 571         if (getnameinfo(ai->ai_addr, ai->ai_addrlen, addr, sizeof(addr), NULL, 0,
 572                         NI_NUMERICHOST) != 0)
 573                 xsnprintf(addr, sizeof(addr), "(unknown)");
 574
 575         return addr;
 576 }
 577
 578 /*
 579  * Returns a connected socket() fd, or else die()s.
 580  */
 581 static int git_tcp_connect_sock(char *host, int flags)
 582 {
 583         struct strbuf error_message = STRBUF_INIT;
 584         int sockfd = -1;
 585         const char *port = STR(DEFAULT_GIT_PORT);
 586         struct addrinfo hints, *ai0, *ai;
 587         int gai;
 588         int cnt = 0;
 589
 590         get_host_and_port(&host, &port);
 591         if (!*port)
 592                 port = "<none>";
 593
 594         memset(&hints, 0, sizeof(hints));
 595         if (flags & CONNECT_IPV4)
 596                 hints.ai_family = AF_INET;
 597         else if (flags & CONNECT_IPV6)
 598                 hints.ai_family = AF_INET6;
 599         hints.ai_socktype = SOCK_STREAM;
 600         hints.ai_protocol = IPPROTO_TCP;
 601
 602         if (flags & CONNECT_VERBOSE)
 603                 fprintf(stderr, "Looking up %s ... ", host);
 604
 605         gai = getaddrinfo(host, port, &hints, &ai);
 606         if (gai)
 607                 die("Unable to look up %s (port %s) (%s)", host, port, gai_strerror(gai));
 608
 609         if (flags & CONNECT_VERBOSE)
 610                 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 611
 612         for (ai0 = ai; ai; ai = ai->ai_next, cnt++) {
 613                 sockfd = socket(ai->ai_family,
 614                                 ai->ai_socktype, ai->ai_protocol);
 615                 if ((sockfd < 0) ||
 616                     (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0)) {
 617                         strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 618                                     host, cnt, ai_name(ai), strerror(errno));
 619                         if (0 <= sockfd)
 620                                 close(sockfd);
 621                         sockfd = -1;
 622                         continue;
 623                 }
 624                 if (flags & CONNECT_VERBOSE)
 625                         fprintf(stderr, "%s ", ai_name(ai));
 626                 break;
 627         }
 628
 629         freeaddrinfo(ai0);
 630
 631         if (sockfd < 0)
 632                 die("unable to connect to %s:\n%s", host, error_message.buf);
 633
 634         enable_keepalive(sockfd);
 635
 636         if (flags & CONNECT_VERBOSE)
 637                 fprintf(stderr, "done.\n");
 638
 639         strbuf_release(&error_message);
 640
 641         return sockfd;
 642 }
 643
 644 #else /* NO_IPV6 */
 645
 646 /*
 647  * Returns a connected socket() fd, or else die()s.
 648  */
 649 static int git_tcp_connect_sock(char *host, int flags)
 650 {
 651         struct strbuf error_message = STRBUF_INIT;
 652         int sockfd = -1;
 653         const char *port = STR(DEFAULT_GIT_PORT);
 654         char *ep;
 655         struct hostent *he;
 656         struct sockaddr_in sa;
 657         char **ap;
 658         unsigned int nport;
 659         int cnt;
 660
 661         get_host_and_port(&host, &port);
 662
 663         if (flags & CONNECT_VERBOSE)
 664                 fprintf(stderr, "Looking up %s ... ", host);
 665
 666         he = gethostbyname(host);
 667         if (!he)
 668                 die("Unable to look up %s (%s)", host, hstrerror(h_errno));
 669         nport = strtoul(port, &ep, 10);
 670         if ( ep == port || *ep ) {
 671                 /* Not numeric */
 672                 struct servent *se = getservbyname(port,"tcp");
 673                 if ( !se )
 674                         die("Unknown port %s", port);
 675                 nport = se->s_port;
 676         }
 677
 678         if (flags & CONNECT_VERBOSE)
 679                 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 680
 681         for (cnt = 0, ap = he->h_addr_list; *ap; ap++, cnt++) {
 682                 memset(&sa, 0, sizeof sa);
 683                 sa.sin_family = he->h_addrtype;
 684                 sa.sin_port = htons(nport);
 685                 memcpy(&sa.sin_addr, *ap, he->h_length);
 686
 687                 sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 688                 if ((sockfd < 0) ||
 689                     connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 690                         strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 691                                 host,
 692                                 cnt,
 693                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr),
 694                                 strerror(errno));
 695                         if (0 <= sockfd)
 696                                 close(sockfd);
 697                         sockfd = -1;
 698                         continue;
 699                 }
 700                 if (flags & CONNECT_VERBOSE)
 701                         fprintf(stderr, "%s ",
 702                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr));
 703                 break;
 704         }
 705
 706         if (sockfd < 0)
 707                 die("unable to connect to %s:\n%s", host, error_message.buf);
 708
 709         enable_keepalive(sockfd);
 710
 711         if (flags & CONNECT_VERBOSE)
 712                 fprintf(stderr, "done.\n");
 713
 714         return sockfd;
 715 }
 716
 717 #endif /* NO_IPV6 */
 718
 719
 720 /*
 721  * Dummy child_process returned by git_connect() if the transport protocol
 722  * does not need fork(2).
 723  */
 724 static struct child_process no_fork = CHILD_PROCESS_INIT;
 725
 726 int git_connection_is_socket(struct child_process *conn)
 727 {
 728         return conn == &no_fork;
 729 }
 730
 731 static struct child_process *git_tcp_connect(int fd[2], char *host, int flags)
 732 {
 733         int sockfd = git_tcp_connect_sock(host, flags);
 734
 735         fd[0] = sockfd;
 736         fd[1] = dup(sockfd);
 737
 738         return &no_fork;
 739 }
 740
 741
 742 static char *git_proxy_command;
 743
 744 static int git_proxy_command_options(const char *var, const char *value,
 745                 void *cb)
 746 {
 747         if (!strcmp(var, "core.gitproxy")) {
 748                 const char *for_pos;
 749                 int matchlen = -1;
 750                 int hostlen;
 751                 const char *rhost_name = cb;
 752                 int rhost_len = strlen(rhost_name);
 753
 754                 if (git_proxy_command)
 755                         return 0;
 756                 if (!value)
 757                         return config_error_nonbool(var);
 758                 /* [core]
 759                  * ;# matches www.kernel.org as well
 760                  * gitproxy = netcatter-1 for kernel.org
 761                  * gitproxy = netcatter-2 for sample.xz
 762                  * gitproxy = netcatter-default
 763                  */
 764                 for_pos = strstr(value, " for ");
 765                 if (!for_pos)
 766                         /* matches everybody */
 767                         matchlen = strlen(value);
 768                 else {
 769                         hostlen = strlen(for_pos + 5);
 770                         if (rhost_len < hostlen)
 771                                 matchlen = -1;
 772                         else if (!strncmp(for_pos + 5,
 773                                           rhost_name + rhost_len - hostlen,
 774                                           hostlen) &&
 775                                  ((rhost_len == hostlen) ||
 776                                   rhost_name[rhost_len - hostlen -1] == '.'))
 777                                 matchlen = for_pos - value;
 778                         else
 779                                 matchlen = -1;
 780                 }
 781                 if (0 <= matchlen) {
 782                         /* core.gitproxy = none for kernel.org */
 783                         if (matchlen == 4 &&
 784                             !memcmp(value, "none", 4))
 785                                 matchlen = 0;
 786                         git_proxy_command = xmemdupz(value, matchlen);
 787                 }
 788                 return 0;
 789         }
 790
 791         return git_default_config(var, value, cb);
 792 }
 793
 794 static int git_use_proxy(const char *host)
 795 {
 796         git_proxy_command = getenv("GIT_PROXY_COMMAND");
 797         git_config(git_proxy_command_options, (void*)host);
 798         return (git_proxy_command && *git_proxy_command);
 799 }
 800
 801 static struct child_process *git_proxy_connect(int fd[2], char *host)
 802 {
 803         const char *port = STR(DEFAULT_GIT_PORT);
 804         struct child_process *proxy;
 805
 806         get_host_and_port(&host, &port);
 807
 808         if (looks_like_command_line_option(host))
 809                 die("strange hostname '%s' blocked", host);
 810         if (looks_like_command_line_option(port))
 811                 die("strange port '%s' blocked", port);
 812
 813         proxy = xmalloc(sizeof(*proxy));
 814         child_process_init(proxy);
 815         argv_array_push(&proxy->args, git_proxy_command);
 816         argv_array_push(&proxy->args, host);
 817         argv_array_push(&proxy->args, port);
 818         proxy->in = -1;
 819         proxy->out = -1;
 820         if (start_command(proxy))
 821                 die("cannot start proxy %s", git_proxy_command);
 822         fd[0] = proxy->out; /* read from proxy stdout */
 823         fd[1] = proxy->in;  /* write to proxy stdin */
 824         return proxy;
 825 }
 826
 827 static char *get_port(char *host)
 828 {
 829         char *end;
 830         char *p = strchr(host, ':');
 831
 832         if (p) {
 833                 long port = strtol(p + 1, &end, 10);
 834                 if (end != p + 1 && *end == '\0' && 0 <= port && port < 65536) {
 835                         *p = '\0';
 836                         return p+1;
 837                 }
 838         }
 839
 840         return NULL;
 841 }
 842
 843 /*
 844  * Extract protocol and relevant parts from the specified connection URL.
 845  * The caller must free() the returned strings.
 846  */
 847 static enum protocol parse_connect_url(const char *url_orig, char **ret_host,
 848                                        char **ret_path)
 849 {
 850         char *url;
 851         char *host, *path;
 852         char *end;
 853         int separator = '/';
 854         enum protocol protocol = PROTO_LOCAL;
 855
 856         if (is_url(url_orig))
 857                 url = url_decode(url_orig);
 858         else
 859                 url = xstrdup(url_orig);
 860
 861         host = strstr(url, "://");
 862         if (host) {
 863                 *host = '\0';
 864                 protocol = get_protocol(url);
 865                 host += 3;
 866         } else {
 867                 host = url;
 868                 if (!url_is_local_not_ssh(url)) {
 869                         protocol = PROTO_SSH;
 870                         separator = ':';
 871                 }
 872         }
 873
 874         /*
 875          * Don't do destructive transforms as protocol code does
 876          * '[]' unwrapping in get_host_and_port()
 877          */
 878         end = host_end(&host, 0);
 879
 880         if (protocol == PROTO_LOCAL)
 881                 path = end;
 882         else if (protocol == PROTO_FILE && has_dos_drive_prefix(end))
 883                 path = end; /* "file://$(pwd)" may be "file://C:/projects/repo" */
 884         else
 885                 path = strchr(end, separator);
 886
 887         if (!path || !*path)
 888                 die("No path specified. See 'man git-pull' for valid url syntax");
 889
 890         /*
 891          * null-terminate hostname and point path to ~ for URL's like this:
 892          *    ssh://host.xz/~user/repo
 893          */
 894
 895         end = path; /* Need to \0 terminate host here */
 896         if (separator == ':')
 897                 path++; /* path starts after ':' */
 898         if (protocol == PROTO_GIT || protocol == PROTO_SSH) {
 899                 if (path[1] == '~')
 900                         path++;
 901         }
 902
 903         path = xstrdup(path);
 904         *end = '\0';
 905
 906         *ret_host = xstrdup(host);
 907         *ret_path = path;
 908         free(url);
 909         return protocol;
 910 }
 911
 912 static const char *get_ssh_command(void)
 913 {
 914         const char *ssh;
 915
 916         if ((ssh = getenv("GIT_SSH_COMMAND")))
 917                 return ssh;
 918
 919         if (!git_config_get_string_const("core.sshcommand", &ssh))
 920                 return ssh;
 921
 922         return NULL;
 923 }
 924
 925 enum ssh_variant {
 926         VARIANT_AUTO,
 927         VARIANT_SIMPLE,
 928         VARIANT_SSH,
 929         VARIANT_PLINK,
 930         VARIANT_PUTTY,
 931         VARIANT_TORTOISEPLINK,
 932 };
 933
 934 static void override_ssh_variant(enum ssh_variant *ssh_variant)
 935 {
 936         const char *variant = getenv("GIT_SSH_VARIANT");
 937
 938         if (!variant && git_config_get_string_const("ssh.variant", &variant))
 939                 return;
 940
 941         if (!strcmp(variant, "auto"))
 942                 *ssh_variant = VARIANT_AUTO;
 943         else if (!strcmp(variant, "plink"))
 944                 *ssh_variant = VARIANT_PLINK;
 945         else if (!strcmp(variant, "putty"))
 946                 *ssh_variant = VARIANT_PUTTY;
 947         else if (!strcmp(variant, "tortoiseplink"))
 948                 *ssh_variant = VARIANT_TORTOISEPLINK;
 949         else if (!strcmp(variant, "simple"))
 950                 *ssh_variant = VARIANT_SIMPLE;
 951         else
 952                 *ssh_variant = VARIANT_SSH;
 953 }
 954
 955 static enum ssh_variant determine_ssh_variant(const char *ssh_command,
 956                                               int is_cmdline)
 957 {
 958         enum ssh_variant ssh_variant = VARIANT_AUTO;
 959         const char *variant;
 960         char *p = NULL;
 961
 962         override_ssh_variant(&ssh_variant);
 963
 964         if (ssh_variant != VARIANT_AUTO)
 965                 return ssh_variant;
 966
 967         if (!is_cmdline) {
 968                 p = xstrdup(ssh_command);
 969                 variant = basename(p);
 970         } else {
 971                 const char **ssh_argv;
 972
 973                 p = xstrdup(ssh_command);
 974                 if (split_cmdline(p, &ssh_argv) > 0) {
 975                         variant = basename((char *)ssh_argv[0]);
 976                         /*
 977                          * At this point, variant points into the buffer
 978                          * referenced by p, hence we do not need ssh_argv
 979                          * any longer.
 980                          */
 981                         free(ssh_argv);
 982                 } else {
 983                         free(p);
 984                         return ssh_variant;
 985                 }
 986         }
 987
 988         if (!strcasecmp(variant, "ssh") ||
 989             !strcasecmp(variant, "ssh.exe"))
 990                 ssh_variant = VARIANT_SSH;
 991         else if (!strcasecmp(variant, "plink") ||
 992                  !strcasecmp(variant, "plink.exe"))
 993                 ssh_variant = VARIANT_PLINK;
 994         else if (!strcasecmp(variant, "tortoiseplink") ||
 995                  !strcasecmp(variant, "tortoiseplink.exe"))
 996                 ssh_variant = VARIANT_TORTOISEPLINK;
 997
 998         free(p);
 999         return ssh_variant;
1000 }
1001
1002 /*
1003  * Open a connection using Git's native protocol.
1004  *
1005  * The caller is responsible for freeing hostandport, but this function may
1006  * modify it (for example, to truncate it to remove the port part).
1007  */
1008 static struct child_process *git_connect_git(int fd[2], char *hostandport,
1009                                              const char *path, const char *prog,
1010                                              int flags)
1011 {
1012         struct child_process *conn;
1013         struct strbuf request = STRBUF_INIT;
1014         /*
1015          * Set up virtual host information based on where we will
1016          * connect, unless the user has overridden us in
1017          * the environment.
1018          */
1019         char *target_host = getenv("GIT_OVERRIDE_VIRTUAL_HOST");
1020         if (target_host)
1021                 target_host = xstrdup(target_host);
1022         else
1023                 target_host = xstrdup(hostandport);
1024
1025         transport_check_allowed("git");
1026
1027         /*
1028          * These underlying connection commands die() if they
1029          * cannot connect.
1030          */
1031         if (git_use_proxy(hostandport))
1032                 conn = git_proxy_connect(fd, hostandport);
1033         else
1034                 conn = git_tcp_connect(fd, hostandport, flags);
1035         /*
1036          * Separate original protocol components prog and path
1037          * from extended host header with a NUL byte.
1038          *
1039          * Note: Do not add any other headers here!  Doing so
1040          * will cause older git-daemon servers to crash.
1041          */
1042         strbuf_addf(&request,
1043                     "%s %s%chost=%s%c",
1044                     prog, path, 0,
1045                     target_host, 0);
1046
1047         /* If using a new version put that stuff here after a second null byte */
1048         if (get_protocol_version_config() > 0) {
1049                 strbuf_addch(&request, '\0');
1050                 strbuf_addf(&request, "version=%d%c",
1051                             get_protocol_version_config(), '\0');
1052         }
1053
1054         packet_write(fd[1], request.buf, request.len);
1055
1056         free(target_host);
1057         strbuf_release(&request);
1058         return conn;
1059 }
1060
1061 /*
1062  * Append the appropriate environment variables to `env` and options to
1063  * `args` for running ssh in Git's SSH-tunneled transport.
1064  */
1065 static void push_ssh_options(struct argv_array *args, struct argv_array *env,
1066                              enum ssh_variant variant, const char *port,
1067                              int flags)
1068 {
1069         if (variant == VARIANT_SSH &&
1070             get_protocol_version_config() > 0) {
1071                 argv_array_push(args, "-o");
1072                 argv_array_push(args, "SendEnv=" GIT_PROTOCOL_ENVIRONMENT);
1073                 argv_array_pushf(env, GIT_PROTOCOL_ENVIRONMENT "=version=%d",
1074                                  get_protocol_version_config());
1075         }
1076
1077         if (flags & CONNECT_IPV4) {
1078                 switch (variant) {
1079                 case VARIANT_AUTO:
1080                         BUG("VARIANT_AUTO passed to push_ssh_options");
1081                 case VARIANT_SIMPLE:
1082                         die("ssh variant 'simple' does not support -4");
1083                 case VARIANT_SSH:
1084                 case VARIANT_PLINK:
1085                 case VARIANT_PUTTY:
1086                 case VARIANT_TORTOISEPLINK:
1087                         argv_array_push(args, "-4");
1088                 }
1089         } else if (flags & CONNECT_IPV6) {
1090                 switch (variant) {
1091                 case VARIANT_AUTO:
1092                         BUG("VARIANT_AUTO passed to push_ssh_options");
1093                 case VARIANT_SIMPLE:
1094                         die("ssh variant 'simple' does not support -6");
1095                 case VARIANT_SSH:
1096                 case VARIANT_PLINK:
1097                 case VARIANT_PUTTY:
1098                 case VARIANT_TORTOISEPLINK:
1099                         argv_array_push(args, "-6");
1100                 }
1101         }
1102
1103         if (variant == VARIANT_TORTOISEPLINK)
1104                 argv_array_push(args, "-batch");
1105
1106         if (port) {
1107                 switch (variant) {
1108                 case VARIANT_AUTO:
1109                         BUG("VARIANT_AUTO passed to push_ssh_options");
1110                 case VARIANT_SIMPLE:
1111                         die("ssh variant 'simple' does not support setting port");
1112                 case VARIANT_SSH:
1113                         argv_array_push(args, "-p");
1114                         break;
1115                 case VARIANT_PLINK:
1116                 case VARIANT_PUTTY:
1117                 case VARIANT_TORTOISEPLINK:
1118                         argv_array_push(args, "-P");
1119                 }
1120
1121                 argv_array_push(args, port);
1122         }
1123 }
1124
1125 /* Prepare a child_process for use by Git's SSH-tunneled transport. */
1126 static void fill_ssh_args(struct child_process *conn, const char *ssh_host,
1127                           const char *port, int flags)
1128 {
1129         const char *ssh;
1130         enum ssh_variant variant;
1131
1132         if (looks_like_command_line_option(ssh_host))
1133                 die("strange hostname '%s' blocked", ssh_host);
1134
1135         ssh = get_ssh_command();
1136         if (ssh) {
1137                 variant = determine_ssh_variant(ssh, 1);
1138         } else {
1139                 /*
1140                  * GIT_SSH is the no-shell version of
1141                  * GIT_SSH_COMMAND (and must remain so for
1142                  * historical compatibility).
1143                  */
1144                 conn->use_shell = 0;
1145
1146                 ssh = getenv("GIT_SSH");
1147                 if (!ssh)
1148                         ssh = "ssh";
1149                 variant = determine_ssh_variant(ssh, 0);
1150         }
1151
1152         if (variant == VARIANT_AUTO) {
1153                 struct child_process detect = CHILD_PROCESS_INIT;
1154
1155                 detect.use_shell = conn->use_shell;
1156                 detect.no_stdin = detect.no_stdout = detect.no_stderr = 1;
1157
1158                 argv_array_push(&detect.args, ssh);
1159                 argv_array_push(&detect.args, "-G");
1160                 push_ssh_options(&detect.args, &detect.env_array,
1161                                  VARIANT_SSH, port, flags);
1162                 argv_array_push(&detect.args, ssh_host);
1163
1164                 variant = run_command(&detect) ? VARIANT_SIMPLE : VARIANT_SSH;
1165         }
1166
1167         argv_array_push(&conn->args, ssh);
1168         push_ssh_options(&conn->args, &conn->env_array, variant, port, flags);
1169         argv_array_push(&conn->args, ssh_host);
1170 }
1171
1172 /*
1173  * This returns the dummy child_process `no_fork` if the transport protocol
1174  * does not need fork(2), or a struct child_process object if it does.  Once
1175  * done, finish the connection with finish_connect() with the value returned
1176  * from this function (it is safe to call finish_connect() with NULL to
1177  * support the former case).
1178  *
1179  * If it returns, the connect is successful; it just dies on errors (this
1180  * will hopefully be changed in a libification effort, to return NULL when
1181  * the connection failed).
1182  */
1183 struct child_process *git_connect(int fd[2], const char *url,
1184                                   const char *prog, int flags)
1185 {
1186         char *hostandport, *path;
1187         struct child_process *conn;
1188         enum protocol protocol;
1189
1190         /* Without this we cannot rely on waitpid() to tell
1191          * what happened to our children.
1192          */
1193         signal(SIGCHLD, SIG_DFL);
1194
1195         protocol = parse_connect_url(url, &hostandport, &path);
1196         if ((flags & CONNECT_DIAG_URL) && (protocol != PROTO_SSH)) {
1197                 printf("Diag: url=%s\n", url ? url : "NULL");
1198                 printf("Diag: protocol=%s\n", prot_name(protocol));
1199                 printf("Diag: hostandport=%s\n", hostandport ? hostandport : "NULL");
1200                 printf("Diag: path=%s\n", path ? path : "NULL");
1201                 conn = NULL;
1202         } else if (protocol == PROTO_GIT) {
1203                 conn = git_connect_git(fd, hostandport, path, prog, flags);
1204         } else {
1205                 struct strbuf cmd = STRBUF_INIT;
1206                 const char *const *var;
1207
1208                 conn = xmalloc(sizeof(*conn));
1209                 child_process_init(conn);
1210
1211                 if (looks_like_command_line_option(path))
1212                         die("strange pathname '%s' blocked", path);
1213
1214                 strbuf_addstr(&cmd, prog);
1215                 strbuf_addch(&cmd, ' ');
1216                 sq_quote_buf(&cmd, path);
1217
1218                 /* remove repo-local variables from the environment */
1219                 for (var = local_repo_env; *var; var++)
1220                         argv_array_push(&conn->env_array, *var);
1221
1222                 conn->use_shell = 1;
1223                 conn->in = conn->out = -1;
1224                 if (protocol == PROTO_SSH) {
1225                         char *ssh_host = hostandport;
1226                         const char *port = NULL;
1227                         transport_check_allowed("ssh");
1228                         get_host_and_port(&ssh_host, &port);
1229
1230                         if (!port)
1231                                 port = get_port(ssh_host);
1232
1233                         if (flags & CONNECT_DIAG_URL) {
1234                                 printf("Diag: url=%s\n", url ? url : "NULL");
1235                                 printf("Diag: protocol=%s\n", prot_name(protocol));
1236                                 printf("Diag: userandhost=%s\n", ssh_host ? ssh_host : "NULL");
1237                                 printf("Diag: port=%s\n", port ? port : "NONE");
1238                                 printf("Diag: path=%s\n", path ? path : "NULL");
1239
1240                                 free(hostandport);
1241                                 free(path);
1242                                 free(conn);
1243                                 strbuf_release(&cmd);
1244                                 return NULL;
1245                         }
1246                         fill_ssh_args(conn, ssh_host, port, flags);
1247                 } else {
1248                         transport_check_allowed("file");
1249                         if (get_protocol_version_config() > 0) {
1250                                 argv_array_pushf(&conn->env_array, GIT_PROTOCOL_ENVIRONMENT "=version=%d",
1251                                                  get_protocol_version_config());
1252                         }
1253                 }
1254                 argv_array_push(&conn->args, cmd.buf);
1255
1256                 if (start_command(conn))
1257                         die("unable to fork");
1258
1259                 fd[0] = conn->out; /* read from child's stdout */
1260                 fd[1] = conn->in;  /* write to child's stdin */
1261                 strbuf_release(&cmd);
1262         }
1263         free(hostandport);
1264         free(path);
1265         return conn;
1266 }
1267
1268 int finish_connect(struct child_process *conn)
1269 {
1270         int code;
1271         if (!conn || git_connection_is_socket(conn))
1272                 return 0;
1273
1274         code = finish_command(conn);
1275         free(conn);
1276         return code;
1277 }