connect.c

   1 #include "git-compat-util.h"
   2 #include "cache.h"
   3 #include "pkt-line.h"
   4 #include "quote.h"
   5 #include "refs.h"
   6 #include "run-command.h"
   7 #include "remote.h"
   8 #include "url.h"
   9
  10 static char *server_capabilities;
  11
  12 static int check_ref(const char *name, int len, unsigned int flags)
  13 {
  14         if (!flags)
  15                 return 1;
  16
  17         if (len < 5 || memcmp(name, "refs/", 5))
  18                 return 0;
  19
  20         /* Skip the "refs/" part */
  21         name += 5;
  22         len -= 5;
  23
  24         /* REF_NORMAL means that we don't want the magic fake tag refs */
  25         if ((flags & REF_NORMAL) && check_ref_format(name) < 0)
  26                 return 0;
  27
  28         /* REF_HEADS means that we want regular branch heads */
  29         if ((flags & REF_HEADS) && !memcmp(name, "heads/", 6))
  30                 return 1;
  31
  32         /* REF_TAGS means that we want tags */
  33         if ((flags & REF_TAGS) && !memcmp(name, "tags/", 5))
  34                 return 1;
  35
  36         /* All type bits clear means that we are ok with anything */
  37         return !(flags & ~REF_NORMAL);
  38 }
  39
  40 int check_ref_type(const struct ref *ref, int flags)
  41 {
  42         return check_ref(ref->name, strlen(ref->name), flags);
  43 }
  44
  45 static void add_extra_have(struct extra_have_objects *extra, unsigned char *sha1)
  46 {
  47         ALLOC_GROW(extra->array, extra->nr + 1, extra->alloc);
  48         hashcpy(&(extra->array[extra->nr][0]), sha1);
  49         extra->nr++;
  50 }
  51
  52 /*
  53  * Read all the refs from the other end
  54  */
  55 struct ref **get_remote_heads(int in, struct ref **list,
  56                               int nr_match, char **match,
  57                               unsigned int flags,
  58                               struct extra_have_objects *extra_have)
  59 {
  60         *list = NULL;
  61         for (;;) {
  62                 struct ref *ref;
  63                 unsigned char old_sha1[20];
  64                 static char buffer[1000];
  65                 char *name;
  66                 int len, name_len;
  67
  68                 len = packet_read_line(in, buffer, sizeof(buffer));
  69                 if (!len)
  70                         break;
  71                 if (buffer[len-1] == '\n')
  72                         buffer[--len] = 0;
  73
  74                 if (len > 4 && !prefixcmp(buffer, "ERR "))
  75                         die("remote error: %s", buffer + 4);
  76
  77                 if (len < 42 || get_sha1_hex(buffer, old_sha1) || buffer[40] != ' ')
  78                         die("protocol error: expected sha/ref, got '%s'", buffer);
  79                 name = buffer + 41;
  80
  81                 name_len = strlen(name);
  82                 if (len != name_len + 41) {
  83                         free(server_capabilities);
  84                         server_capabilities = xstrdup(name + name_len + 1);
  85                 }
  86
  87                 if (extra_have &&
  88                     name_len == 5 && !memcmp(".have", name, 5)) {
  89                         add_extra_have(extra_have, old_sha1);
  90                         continue;
  91                 }
  92
  93                 if (!check_ref(name, name_len, flags))
  94                         continue;
  95                 if (nr_match && !path_match(name, nr_match, match))
  96                         continue;
  97                 ref = alloc_ref(buffer + 41);
  98                 hashcpy(ref->old_sha1, old_sha1);
  99                 *list = ref;
 100                 list = &ref->next;
 101         }
 102         return list;
 103 }
 104
 105 int server_supports(const char *feature)
 106 {
 107         return server_capabilities &&
 108                 strstr(server_capabilities, feature) != NULL;
 109 }
 110
 111 int path_match(const char *path, int nr, char **match)
 112 {
 113         int i;
 114         int pathlen = strlen(path);
 115
 116         for (i = 0; i < nr; i++) {
 117                 char *s = match[i];
 118                 int len = strlen(s);
 119
 120                 if (!len || len > pathlen)
 121                         continue;
 122                 if (memcmp(path + pathlen - len, s, len))
 123                         continue;
 124                 if (pathlen > len && path[pathlen - len - 1] != '/')
 125                         continue;
 126                 *s = 0;
 127                 return (i + 1);
 128         }
 129         return 0;
 130 }
 131
 132 enum protocol {
 133         PROTO_LOCAL = 1,
 134         PROTO_SSH,
 135         PROTO_GIT
 136 };
 137
 138 static enum protocol get_protocol(const char *name)
 139 {
 140         if (!strcmp(name, "ssh"))
 141                 return PROTO_SSH;
 142         if (!strcmp(name, "git"))
 143                 return PROTO_GIT;
 144         if (!strcmp(name, "git+ssh"))
 145                 return PROTO_SSH;
 146         if (!strcmp(name, "ssh+git"))
 147                 return PROTO_SSH;
 148         if (!strcmp(name, "file"))
 149                 return PROTO_LOCAL;
 150         die("I don't handle protocol '%s'", name);
 151 }
 152
 153 #define STR_(s) # s
 154 #define STR(s)  STR_(s)
 155
 156 static void get_host_and_port(char **host, const char **port)
 157 {
 158         char *colon, *end;
 159
 160         if (*host[0] == '[') {
 161                 end = strchr(*host + 1, ']');
 162                 if (end) {
 163                         *end = 0;
 164                         end++;
 165                         (*host)++;
 166                 } else
 167                         end = *host;
 168         } else
 169                 end = *host;
 170         colon = strchr(end, ':');
 171
 172         if (colon) {
 173                 *colon = 0;
 174                 *port = colon + 1;
 175         }
 176 }
 177
 178 #ifndef NO_IPV6
 179
 180 static const char *ai_name(const struct addrinfo *ai)
 181 {
 182         static char addr[NI_MAXHOST];
 183         if (getnameinfo(ai->ai_addr, ai->ai_addrlen, addr, sizeof(addr), NULL, 0,
 184                         NI_NUMERICHOST) != 0)
 185                 strcpy(addr, "(unknown)");
 186
 187         return addr;
 188 }
 189
 190 /*
 191  * Returns a connected socket() fd, or else die()s.
 192  */
 193 static int git_tcp_connect_sock(char *host, int flags)
 194 {
 195         struct strbuf error_message = STRBUF_INIT;
 196         int sockfd = -1;
 197         const char *port = STR(DEFAULT_GIT_PORT);
 198         struct addrinfo hints, *ai0, *ai;
 199         int gai;
 200         int cnt = 0;
 201
 202         get_host_and_port(&host, &port);
 203         if (!*port)
 204                 port = "<none>";
 205
 206         memset(&hints, 0, sizeof(hints));
 207         hints.ai_socktype = SOCK_STREAM;
 208         hints.ai_protocol = IPPROTO_TCP;
 209
 210         if (flags & CONNECT_VERBOSE)
 211                 fprintf(stderr, "Looking up %s ... ", host);
 212
 213         gai = getaddrinfo(host, port, &hints, &ai);
 214         if (gai)
 215                 die("Unable to look up %s (port %s) (%s)", host, port, gai_strerror(gai));
 216
 217         if (flags & CONNECT_VERBOSE)
 218                 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 219
 220         for (ai0 = ai; ai; ai = ai->ai_next, cnt++) {
 221                 sockfd = socket(ai->ai_family,
 222                                 ai->ai_socktype, ai->ai_protocol);
 223                 if ((sockfd < 0) ||
 224                     (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0)) {
 225                         strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 226                                     host, cnt, ai_name(ai), strerror(errno));
 227                         if (0 <= sockfd)
 228                                 close(sockfd);
 229                         sockfd = -1;
 230                         continue;
 231                 }
 232                 if (flags & CONNECT_VERBOSE)
 233                         fprintf(stderr, "%s ", ai_name(ai));
 234                 break;
 235         }
 236
 237         freeaddrinfo(ai0);
 238
 239         if (sockfd < 0)
 240                 die("unable to connect to %s:\n%s", host, error_message.buf);
 241
 242         if (flags & CONNECT_VERBOSE)
 243                 fprintf(stderr, "done.\n");
 244
 245         strbuf_release(&error_message);
 246
 247         return sockfd;
 248 }
 249
 250 #else /* NO_IPV6 */
 251
 252 /*
 253  * Returns a connected socket() fd, or else die()s.
 254  */
 255 static int git_tcp_connect_sock(char *host, int flags)
 256 {
 257         int sockfd = -1, saved_errno = 0;
 258         const char *port = STR(DEFAULT_GIT_PORT);
 259         char *ep;
 260         struct hostent *he;
 261         struct sockaddr_in sa;
 262         char **ap;
 263         unsigned int nport;
 264         int cnt;
 265
 266         get_host_and_port(&host, &port);
 267
 268         if (flags & CONNECT_VERBOSE)
 269                 fprintf(stderr, "Looking up %s ... ", host);
 270
 271         he = gethostbyname(host);
 272         if (!he)
 273                 die("Unable to look up %s (%s)", host, hstrerror(h_errno));
 274         nport = strtoul(port, &ep, 10);
 275         if ( ep == port || *ep ) {
 276                 /* Not numeric */
 277                 struct servent *se = getservbyname(port,"tcp");
 278                 if ( !se )
 279                         die("Unknown port %s", port);
 280                 nport = se->s_port;
 281         }
 282
 283         if (flags & CONNECT_VERBOSE)
 284                 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 285
 286         for (cnt = 0, ap = he->h_addr_list; *ap; ap++, cnt++) {
 287                 sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 288                 if (sockfd < 0) {
 289                         saved_errno = errno;
 290                         continue;
 291                 }
 292
 293                 memset(&sa, 0, sizeof sa);
 294                 sa.sin_family = he->h_addrtype;
 295                 sa.sin_port = htons(nport);
 296                 memcpy(&sa.sin_addr, *ap, he->h_length);
 297
 298                 if (connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 299                         saved_errno = errno;
 300                         fprintf(stderr, "%s[%d: %s]: errno=%s\n",
 301                                 host,
 302                                 cnt,
 303                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr),
 304                                 strerror(saved_errno));
 305                         close(sockfd);
 306                         sockfd = -1;
 307                         continue;
 308                 }
 309                 if (flags & CONNECT_VERBOSE)
 310                         fprintf(stderr, "%s ",
 311                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr));
 312                 break;
 313         }
 314
 315         if (sockfd < 0)
 316                 die("unable to connect a socket (%s)", strerror(saved_errno));
 317
 318         if (flags & CONNECT_VERBOSE)
 319                 fprintf(stderr, "done.\n");
 320
 321         return sockfd;
 322 }
 323
 324 #endif /* NO_IPV6 */
 325
 326
 327 static void git_tcp_connect(int fd[2], char *host, int flags)
 328 {
 329         int sockfd = git_tcp_connect_sock(host, flags);
 330
 331         fd[0] = sockfd;
 332         fd[1] = dup(sockfd);
 333 }
 334
 335
 336 static char *git_proxy_command;
 337
 338 static int git_proxy_command_options(const char *var, const char *value,
 339                 void *cb)
 340 {
 341         if (!strcmp(var, "core.gitproxy")) {
 342                 const char *for_pos;
 343                 int matchlen = -1;
 344                 int hostlen;
 345                 const char *rhost_name = cb;
 346                 int rhost_len = strlen(rhost_name);
 347
 348                 if (git_proxy_command)
 349                         return 0;
 350                 if (!value)
 351                         return config_error_nonbool(var);
 352                 /* [core]
 353                  * ;# matches www.kernel.org as well
 354                  * gitproxy = netcatter-1 for kernel.org
 355                  * gitproxy = netcatter-2 for sample.xz
 356                  * gitproxy = netcatter-default
 357                  */
 358                 for_pos = strstr(value, " for ");
 359                 if (!for_pos)
 360                         /* matches everybody */
 361                         matchlen = strlen(value);
 362                 else {
 363                         hostlen = strlen(for_pos + 5);
 364                         if (rhost_len < hostlen)
 365                                 matchlen = -1;
 366                         else if (!strncmp(for_pos + 5,
 367                                           rhost_name + rhost_len - hostlen,
 368                                           hostlen) &&
 369                                  ((rhost_len == hostlen) ||
 370                                   rhost_name[rhost_len - hostlen -1] == '.'))
 371                                 matchlen = for_pos - value;
 372                         else
 373                                 matchlen = -1;
 374                 }
 375                 if (0 <= matchlen) {
 376                         /* core.gitproxy = none for kernel.org */
 377                         if (matchlen == 4 &&
 378                             !memcmp(value, "none", 4))
 379                                 matchlen = 0;
 380                         git_proxy_command = xmemdupz(value, matchlen);
 381                 }
 382                 return 0;
 383         }
 384
 385         return git_default_config(var, value, cb);
 386 }
 387
 388 static int git_use_proxy(const char *host)
 389 {
 390         git_proxy_command = getenv("GIT_PROXY_COMMAND");
 391         git_config(git_proxy_command_options, (void*)host);
 392         return (git_proxy_command && *git_proxy_command);
 393 }
 394
 395 static struct child_process *git_proxy_connect(int fd[2], char *host)
 396 {
 397         const char *port = STR(DEFAULT_GIT_PORT);
 398         const char **argv;
 399         struct child_process *proxy;
 400
 401         get_host_and_port(&host, &port);
 402
 403         argv = xmalloc(sizeof(*argv) * 4);
 404         argv[0] = git_proxy_command;
 405         argv[1] = host;
 406         argv[2] = port;
 407         argv[3] = NULL;
 408         proxy = xcalloc(1, sizeof(*proxy));
 409         proxy->argv = argv;
 410         proxy->in = -1;
 411         proxy->out = -1;
 412         if (start_command(proxy))
 413                 die("cannot start proxy %s", argv[0]);
 414         fd[0] = proxy->out; /* read from proxy stdout */
 415         fd[1] = proxy->in;  /* write to proxy stdin */
 416         return proxy;
 417 }
 418
 419 #define MAX_CMD_LEN 1024
 420
 421 static char *get_port(char *host)
 422 {
 423         char *end;
 424         char *p = strchr(host, ':');
 425
 426         if (p) {
 427                 long port = strtol(p + 1, &end, 10);
 428                 if (end != p + 1 && *end == '\0' && 0 <= port && port < 65536) {
 429                         *p = '\0';
 430                         return p+1;
 431                 }
 432         }
 433
 434         return NULL;
 435 }
 436
 437 static struct child_process no_fork;
 438
 439 /*
 440  * This returns a dummy child_process if the transport protocol does not
 441  * need fork(2), or a struct child_process object if it does.  Once done,
 442  * finish the connection with finish_connect() with the value returned from
 443  * this function (it is safe to call finish_connect() with NULL to support
 444  * the former case).
 445  *
 446  * If it returns, the connect is successful; it just dies on errors (this
 447  * will hopefully be changed in a libification effort, to return NULL when
 448  * the connection failed).
 449  */
 450 struct child_process *git_connect(int fd[2], const char *url_orig,
 451                                   const char *prog, int flags)
 452 {
 453         char *url;
 454         char *host, *path;
 455         char *end;
 456         int c;
 457         struct child_process *conn = &no_fork;
 458         enum protocol protocol = PROTO_LOCAL;
 459         int free_path = 0;
 460         char *port = NULL;
 461         const char **arg;
 462         struct strbuf cmd;
 463
 464         /* Without this we cannot rely on waitpid() to tell
 465          * what happened to our children.
 466          */
 467         signal(SIGCHLD, SIG_DFL);
 468
 469         if (is_url(url_orig))
 470                 url = url_decode(url_orig);
 471         else
 472                 url = xstrdup(url_orig);
 473
 474         host = strstr(url, "://");
 475         if (host) {
 476                 *host = '\0';
 477                 protocol = get_protocol(url);
 478                 host += 3;
 479                 c = '/';
 480         } else {
 481                 host = url;
 482                 c = ':';
 483         }
 484
 485         /*
 486          * Don't do destructive transforms with git:// as that
 487          * protocol code does '[]' unwrapping of its own.
 488          */
 489         if (host[0] == '[') {
 490                 end = strchr(host + 1, ']');
 491                 if (end) {
 492                         if (protocol != PROTO_GIT) {
 493                                 *end = 0;
 494                                 host++;
 495                         }
 496                         end++;
 497                 } else
 498                         end = host;
 499         } else
 500                 end = host;
 501
 502         path = strchr(end, c);
 503         if (path && !has_dos_drive_prefix(end)) {
 504                 if (c == ':') {
 505                         protocol = PROTO_SSH;
 506                         *path++ = '\0';
 507                 }
 508         } else
 509                 path = end;
 510
 511         if (!path || !*path)
 512                 die("No path specified. See 'man git-pull' for valid url syntax");
 513
 514         /*
 515          * null-terminate hostname and point path to ~ for URL's like this:
 516          *    ssh://host.xz/~user/repo
 517          */
 518         if (protocol != PROTO_LOCAL && host != url) {
 519                 char *ptr = path;
 520                 if (path[1] == '~')
 521                         path++;
 522                 else {
 523                         path = xstrdup(ptr);
 524                         free_path = 1;
 525                 }
 526
 527                 *ptr = '\0';
 528         }
 529
 530         /*
 531          * Add support for ssh port: ssh://host.xy:<port>/...
 532          */
 533         if (protocol == PROTO_SSH && host != url)
 534                 port = get_port(host);
 535
 536         if (protocol == PROTO_GIT) {
 537                 /* These underlying connection commands die() if they
 538                  * cannot connect.
 539                  */
 540                 char *target_host = xstrdup(host);
 541                 if (git_use_proxy(host))
 542                         conn = git_proxy_connect(fd, host);
 543                 else
 544                         git_tcp_connect(fd, host, flags);
 545                 /*
 546                  * Separate original protocol components prog and path
 547                  * from extended host header with a NUL byte.
 548                  *
 549                  * Note: Do not add any other headers here!  Doing so
 550                  * will cause older git-daemon servers to crash.
 551                  */
 552                 packet_write(fd[1],
 553                              "%s %s%chost=%s%c",
 554                              prog, path, 0,
 555                              target_host, 0);
 556                 free(target_host);
 557                 free(url);
 558                 if (free_path)
 559                         free(path);
 560                 return conn;
 561         }
 562
 563         conn = xcalloc(1, sizeof(*conn));
 564
 565         strbuf_init(&cmd, MAX_CMD_LEN);
 566         strbuf_addstr(&cmd, prog);
 567         strbuf_addch(&cmd, ' ');
 568         sq_quote_buf(&cmd, path);
 569         if (cmd.len >= MAX_CMD_LEN)
 570                 die("command line too long");
 571
 572         conn->in = conn->out = -1;
 573         conn->argv = arg = xcalloc(7, sizeof(*arg));
 574         if (protocol == PROTO_SSH) {
 575                 const char *ssh = getenv("GIT_SSH");
 576                 int putty = ssh && strcasestr(ssh, "plink");
 577                 if (!ssh) ssh = "ssh";
 578
 579                 *arg++ = ssh;
 580                 if (putty && !strcasestr(ssh, "tortoiseplink"))
 581                         *arg++ = "-batch";
 582                 if (port) {
 583                         /* P is for PuTTY, p is for OpenSSH */
 584                         *arg++ = putty ? "-P" : "-p";
 585                         *arg++ = port;
 586                 }
 587                 *arg++ = host;
 588         }
 589         else {
 590                 /* remove repo-local variables from the environment */
 591                 conn->env = local_repo_env;
 592                 conn->use_shell = 1;
 593         }
 594         *arg++ = cmd.buf;
 595         *arg = NULL;
 596
 597         if (start_command(conn))
 598                 die("unable to fork");
 599
 600         fd[0] = conn->out; /* read from child's stdout */
 601         fd[1] = conn->in;  /* write to child's stdin */
 602         strbuf_release(&cmd);
 603         free(url);
 604         if (free_path)
 605                 free(path);
 606         return conn;
 607 }
 608
 609 int git_connection_is_socket(struct child_process *conn)
 610 {
 611         return conn == &no_fork;
 612 }
 613
 614 int finish_connect(struct child_process *conn)
 615 {
 616         int code;
 617         if (!conn || git_connection_is_socket(conn))
 618                 return 0;
 619
 620         code = finish_command(conn);
 621         free(conn->argv);
 622         free(conn);
 623         return code;
 624 }
 625
 626 char *git_getpass(const char *prompt)
 627 {
 628         const char *askpass;
 629         struct child_process pass;
 630         const char *args[3];
 631         static struct strbuf buffer = STRBUF_INIT;
 632
 633         askpass = getenv("GIT_ASKPASS");
 634         if (!askpass)
 635                 askpass = askpass_program;
 636         if (!askpass)
 637                 askpass = getenv("SSH_ASKPASS");
 638         if (!askpass || !(*askpass)) {
 639                 char *result = getpass(prompt);
 640                 if (!result)
 641                         die_errno("Could not read password");
 642                 return result;
 643         }
 644
 645         args[0] = askpass;
 646         args[1] = prompt;
 647         args[2] = NULL;
 648
 649         memset(&pass, 0, sizeof(pass));
 650         pass.argv = args;
 651         pass.out = -1;
 652
 653         if (start_command(&pass))
 654                 exit(1);
 655
 656         strbuf_reset(&buffer);
 657         if (strbuf_read(&buffer, pass.out, 20) < 0)
 658                 die("failed to read password from %s\n", askpass);
 659
 660         close(pass.out);
 661
 662         if (finish_command(&pass))
 663                 exit(1);
 664
 665         strbuf_setlen(&buffer, strcspn(buffer.buf, "\r\n"));
 666
 667         return buffer.buf;
 668 }