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_refname_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         struct strbuf error_message = STRBUF_INIT;
 258         int sockfd = -1;
 259         const char *port = STR(DEFAULT_GIT_PORT);
 260         char *ep;
 261         struct hostent *he;
 262         struct sockaddr_in sa;
 263         char **ap;
 264         unsigned int nport;
 265         int cnt;
 266
 267         get_host_and_port(&host, &port);
 268
 269         if (flags & CONNECT_VERBOSE)
 270                 fprintf(stderr, "Looking up %s ... ", host);
 271
 272         he = gethostbyname(host);
 273         if (!he)
 274                 die("Unable to look up %s (%s)", host, hstrerror(h_errno));
 275         nport = strtoul(port, &ep, 10);
 276         if ( ep == port || *ep ) {
 277                 /* Not numeric */
 278                 struct servent *se = getservbyname(port,"tcp");
 279                 if ( !se )
 280                         die("Unknown port %s", port);
 281                 nport = se->s_port;
 282         }
 283
 284         if (flags & CONNECT_VERBOSE)
 285                 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 286
 287         for (cnt = 0, ap = he->h_addr_list; *ap; ap++, cnt++) {
 288                 memset(&sa, 0, sizeof sa);
 289                 sa.sin_family = he->h_addrtype;
 290                 sa.sin_port = htons(nport);
 291                 memcpy(&sa.sin_addr, *ap, he->h_length);
 292
 293                 sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 294                 if ((sockfd < 0) ||
 295                     connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 296                         strbuf_addf(&error_message, "%s[%d: %s]: errno=%s\n",
 297                                 host,
 298                                 cnt,
 299                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr),
 300                                 strerror(errno));
 301                         if (0 <= sockfd)
 302                                 close(sockfd);
 303                         sockfd = -1;
 304                         continue;
 305                 }
 306                 if (flags & CONNECT_VERBOSE)
 307                         fprintf(stderr, "%s ",
 308                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr));
 309                 break;
 310         }
 311
 312         if (sockfd < 0)
 313                 die("unable to connect to %s:\n%s", host, error_message.buf);
 314
 315         if (flags & CONNECT_VERBOSE)
 316                 fprintf(stderr, "done.\n");
 317
 318         return sockfd;
 319 }
 320
 321 #endif /* NO_IPV6 */
 322
 323
 324 static void git_tcp_connect(int fd[2], char *host, int flags)
 325 {
 326         int sockfd = git_tcp_connect_sock(host, flags);
 327
 328         fd[0] = sockfd;
 329         fd[1] = dup(sockfd);
 330 }
 331
 332
 333 static char *git_proxy_command;
 334
 335 static int git_proxy_command_options(const char *var, const char *value,
 336                 void *cb)
 337 {
 338         if (!strcmp(var, "core.gitproxy")) {
 339                 const char *for_pos;
 340                 int matchlen = -1;
 341                 int hostlen;
 342                 const char *rhost_name = cb;
 343                 int rhost_len = strlen(rhost_name);
 344
 345                 if (git_proxy_command)
 346                         return 0;
 347                 if (!value)
 348                         return config_error_nonbool(var);
 349                 /* [core]
 350                  * ;# matches www.kernel.org as well
 351                  * gitproxy = netcatter-1 for kernel.org
 352                  * gitproxy = netcatter-2 for sample.xz
 353                  * gitproxy = netcatter-default
 354                  */
 355                 for_pos = strstr(value, " for ");
 356                 if (!for_pos)
 357                         /* matches everybody */
 358                         matchlen = strlen(value);
 359                 else {
 360                         hostlen = strlen(for_pos + 5);
 361                         if (rhost_len < hostlen)
 362                                 matchlen = -1;
 363                         else if (!strncmp(for_pos + 5,
 364                                           rhost_name + rhost_len - hostlen,
 365                                           hostlen) &&
 366                                  ((rhost_len == hostlen) ||
 367                                   rhost_name[rhost_len - hostlen -1] == '.'))
 368                                 matchlen = for_pos - value;
 369                         else
 370                                 matchlen = -1;
 371                 }
 372                 if (0 <= matchlen) {
 373                         /* core.gitproxy = none for kernel.org */
 374                         if (matchlen == 4 &&
 375                             !memcmp(value, "none", 4))
 376                                 matchlen = 0;
 377                         git_proxy_command = xmemdupz(value, matchlen);
 378                 }
 379                 return 0;
 380         }
 381
 382         return git_default_config(var, value, cb);
 383 }
 384
 385 static int git_use_proxy(const char *host)
 386 {
 387         git_proxy_command = getenv("GIT_PROXY_COMMAND");
 388         git_config(git_proxy_command_options, (void*)host);
 389         return (git_proxy_command && *git_proxy_command);
 390 }
 391
 392 static struct child_process *git_proxy_connect(int fd[2], char *host)
 393 {
 394         const char *port = STR(DEFAULT_GIT_PORT);
 395         const char **argv;
 396         struct child_process *proxy;
 397
 398         get_host_and_port(&host, &port);
 399
 400         argv = xmalloc(sizeof(*argv) * 4);
 401         argv[0] = git_proxy_command;
 402         argv[1] = host;
 403         argv[2] = port;
 404         argv[3] = NULL;
 405         proxy = xcalloc(1, sizeof(*proxy));
 406         proxy->argv = argv;
 407         proxy->in = -1;
 408         proxy->out = -1;
 409         if (start_command(proxy))
 410                 die("cannot start proxy %s", argv[0]);
 411         fd[0] = proxy->out; /* read from proxy stdout */
 412         fd[1] = proxy->in;  /* write to proxy stdin */
 413         return proxy;
 414 }
 415
 416 #define MAX_CMD_LEN 1024
 417
 418 static char *get_port(char *host)
 419 {
 420         char *end;
 421         char *p = strchr(host, ':');
 422
 423         if (p) {
 424                 long port = strtol(p + 1, &end, 10);
 425                 if (end != p + 1 && *end == '\0' && 0 <= port && port < 65536) {
 426                         *p = '\0';
 427                         return p+1;
 428                 }
 429         }
 430
 431         return NULL;
 432 }
 433
 434 static struct child_process no_fork;
 435
 436 /*
 437  * This returns a dummy child_process if the transport protocol does not
 438  * need fork(2), or a struct child_process object if it does.  Once done,
 439  * finish the connection with finish_connect() with the value returned from
 440  * this function (it is safe to call finish_connect() with NULL to support
 441  * the former case).
 442  *
 443  * If it returns, the connect is successful; it just dies on errors (this
 444  * will hopefully be changed in a libification effort, to return NULL when
 445  * the connection failed).
 446  */
 447 struct child_process *git_connect(int fd[2], const char *url_orig,
 448                                   const char *prog, int flags)
 449 {
 450         char *url;
 451         char *host, *path;
 452         char *end;
 453         int c;
 454         struct child_process *conn = &no_fork;
 455         enum protocol protocol = PROTO_LOCAL;
 456         int free_path = 0;
 457         char *port = NULL;
 458         const char **arg;
 459         struct strbuf cmd;
 460
 461         /* Without this we cannot rely on waitpid() to tell
 462          * what happened to our children.
 463          */
 464         signal(SIGCHLD, SIG_DFL);
 465
 466         if (is_url(url_orig))
 467                 url = url_decode(url_orig);
 468         else
 469                 url = xstrdup(url_orig);
 470
 471         host = strstr(url, "://");
 472         if (host) {
 473                 *host = '\0';
 474                 protocol = get_protocol(url);
 475                 host += 3;
 476                 c = '/';
 477         } else {
 478                 host = url;
 479                 c = ':';
 480         }
 481
 482         /*
 483          * Don't do destructive transforms with git:// as that
 484          * protocol code does '[]' unwrapping of its own.
 485          */
 486         if (host[0] == '[') {
 487                 end = strchr(host + 1, ']');
 488                 if (end) {
 489                         if (protocol != PROTO_GIT) {
 490                                 *end = 0;
 491                                 host++;
 492                         }
 493                         end++;
 494                 } else
 495                         end = host;
 496         } else
 497                 end = host;
 498
 499         path = strchr(end, c);
 500         if (path && !has_dos_drive_prefix(end)) {
 501                 if (c == ':') {
 502                         protocol = PROTO_SSH;
 503                         *path++ = '\0';
 504                 }
 505         } else
 506                 path = end;
 507
 508         if (!path || !*path)
 509                 die("No path specified. See 'man git-pull' for valid url syntax");
 510
 511         /*
 512          * null-terminate hostname and point path to ~ for URL's like this:
 513          *    ssh://host.xz/~user/repo
 514          */
 515         if (protocol != PROTO_LOCAL && host != url) {
 516                 char *ptr = path;
 517                 if (path[1] == '~')
 518                         path++;
 519                 else {
 520                         path = xstrdup(ptr);
 521                         free_path = 1;
 522                 }
 523
 524                 *ptr = '\0';
 525         }
 526
 527         /*
 528          * Add support for ssh port: ssh://host.xy:<port>/...
 529          */
 530         if (protocol == PROTO_SSH && host != url)
 531                 port = get_port(host);
 532
 533         if (protocol == PROTO_GIT) {
 534                 /* These underlying connection commands die() if they
 535                  * cannot connect.
 536                  */
 537                 char *target_host = xstrdup(host);
 538                 if (git_use_proxy(host))
 539                         conn = git_proxy_connect(fd, host);
 540                 else
 541                         git_tcp_connect(fd, host, flags);
 542                 /*
 543                  * Separate original protocol components prog and path
 544                  * from extended host header with a NUL byte.
 545                  *
 546                  * Note: Do not add any other headers here!  Doing so
 547                  * will cause older git-daemon servers to crash.
 548                  */
 549                 packet_write(fd[1],
 550                              "%s %s%chost=%s%c",
 551                              prog, path, 0,
 552                              target_host, 0);
 553                 free(target_host);
 554                 free(url);
 555                 if (free_path)
 556                         free(path);
 557                 return conn;
 558         }
 559
 560         conn = xcalloc(1, sizeof(*conn));
 561
 562         strbuf_init(&cmd, MAX_CMD_LEN);
 563         strbuf_addstr(&cmd, prog);
 564         strbuf_addch(&cmd, ' ');
 565         sq_quote_buf(&cmd, path);
 566         if (cmd.len >= MAX_CMD_LEN)
 567                 die("command line too long");
 568
 569         conn->in = conn->out = -1;
 570         conn->argv = arg = xcalloc(7, sizeof(*arg));
 571         if (protocol == PROTO_SSH) {
 572                 const char *ssh = getenv("GIT_SSH");
 573                 int putty = ssh && strcasestr(ssh, "plink");
 574                 if (!ssh) ssh = "ssh";
 575
 576                 *arg++ = ssh;
 577                 if (putty && !strcasestr(ssh, "tortoiseplink"))
 578                         *arg++ = "-batch";
 579                 if (port) {
 580                         /* P is for PuTTY, p is for OpenSSH */
 581                         *arg++ = putty ? "-P" : "-p";
 582                         *arg++ = port;
 583                 }
 584                 *arg++ = host;
 585         }
 586         else {
 587                 /* remove repo-local variables from the environment */
 588                 conn->env = local_repo_env;
 589                 conn->use_shell = 1;
 590         }
 591         *arg++ = cmd.buf;
 592         *arg = NULL;
 593
 594         if (start_command(conn))
 595                 die("unable to fork");
 596
 597         fd[0] = conn->out; /* read from child's stdout */
 598         fd[1] = conn->in;  /* write to child's stdin */
 599         strbuf_release(&cmd);
 600         free(url);
 601         if (free_path)
 602                 free(path);
 603         return conn;
 604 }
 605
 606 int git_connection_is_socket(struct child_process *conn)
 607 {
 608         return conn == &no_fork;
 609 }
 610
 611 int finish_connect(struct child_process *conn)
 612 {
 613         int code;
 614         if (!conn || git_connection_is_socket(conn))
 615                 return 0;
 616
 617         code = finish_command(conn);
 618         free(conn->argv);
 619         free(conn);
 620         return code;
 621 }
 622
 623 char *git_getpass(const char *prompt)
 624 {
 625         const char *askpass;
 626         struct child_process pass;
 627         const char *args[3];
 628         static struct strbuf buffer = STRBUF_INIT;
 629
 630         askpass = getenv("GIT_ASKPASS");
 631         if (!askpass)
 632                 askpass = askpass_program;
 633         if (!askpass)
 634                 askpass = getenv("SSH_ASKPASS");
 635         if (!askpass || !(*askpass)) {
 636                 char *result = getpass(prompt);
 637                 if (!result)
 638                         die_errno("Could not read password");
 639                 return result;
 640         }
 641
 642         args[0] = askpass;
 643         args[1] = prompt;
 644         args[2] = NULL;
 645
 646         memset(&pass, 0, sizeof(pass));
 647         pass.argv = args;
 648         pass.out = -1;
 649
 650         if (start_command(&pass))
 651                 exit(1);
 652
 653         strbuf_reset(&buffer);
 654         if (strbuf_read(&buffer, pass.out, 20) < 0)
 655                 die("failed to read password from %s\n", askpass);
 656
 657         close(pass.out);
 658
 659         if (finish_command(&pass))
 660                 exit(1);
 661
 662         strbuf_setlen(&buffer, strcspn(buffer.buf, "\r\n"));
 663
 664         return buffer.buf;
 665 }