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         int sockfd = -1, saved_errno = 0;
 196         const char *port = STR(DEFAULT_GIT_PORT);
 197         struct addrinfo hints, *ai0, *ai;
 198         int gai;
 199         int cnt = 0;
 200
 201         get_host_and_port(&host, &port);
 202         if (!*port)
 203                 port = "<none>";
 204
 205         memset(&hints, 0, sizeof(hints));
 206         hints.ai_socktype = SOCK_STREAM;
 207         hints.ai_protocol = IPPROTO_TCP;
 208
 209         if (flags & CONNECT_VERBOSE)
 210                 fprintf(stderr, "Looking up %s ... ", host);
 211
 212         gai = getaddrinfo(host, port, &hints, &ai);
 213         if (gai)
 214                 die("Unable to look up %s (port %s) (%s)", host, port, gai_strerror(gai));
 215
 216         if (flags & CONNECT_VERBOSE)
 217                 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 218
 219         for (ai0 = ai; ai; ai = ai->ai_next, cnt++) {
 220                 sockfd = socket(ai->ai_family,
 221                                 ai->ai_socktype, ai->ai_protocol);
 222                 if (sockfd < 0) {
 223                         saved_errno = errno;
 224                         continue;
 225                 }
 226                 if (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
 227                         saved_errno = errno;
 228                         fprintf(stderr, "%s[%d: %s]: errno=%s\n",
 229                                 host,
 230                                 cnt,
 231                                 ai_name(ai),
 232                                 strerror(saved_errno));
 233                         close(sockfd);
 234                         sockfd = -1;
 235                         continue;
 236                 }
 237                 if (flags & CONNECT_VERBOSE)
 238                         fprintf(stderr, "%s ", ai_name(ai));
 239                 break;
 240         }
 241
 242         freeaddrinfo(ai0);
 243
 244         if (sockfd < 0)
 245                 die("unable to connect a socket (%s)", strerror(saved_errno));
 246
 247         if (flags & CONNECT_VERBOSE)
 248                 fprintf(stderr, "done.\n");
 249
 250         return sockfd;
 251 }
 252
 253 #else /* NO_IPV6 */
 254
 255 /*
 256  * Returns a connected socket() fd, or else die()s.
 257  */
 258 static int git_tcp_connect_sock(char *host, int flags)
 259 {
 260         int sockfd = -1, saved_errno = 0;
 261         const char *port = STR(DEFAULT_GIT_PORT);
 262         char *ep;
 263         struct hostent *he;
 264         struct sockaddr_in sa;
 265         char **ap;
 266         unsigned int nport;
 267         int cnt;
 268
 269         get_host_and_port(&host, &port);
 270
 271         if (flags & CONNECT_VERBOSE)
 272                 fprintf(stderr, "Looking up %s ... ", host);
 273
 274         he = gethostbyname(host);
 275         if (!he)
 276                 die("Unable to look up %s (%s)", host, hstrerror(h_errno));
 277         nport = strtoul(port, &ep, 10);
 278         if ( ep == port || *ep ) {
 279                 /* Not numeric */
 280                 struct servent *se = getservbyname(port,"tcp");
 281                 if ( !se )
 282                         die("Unknown port %s", port);
 283                 nport = se->s_port;
 284         }
 285
 286         if (flags & CONNECT_VERBOSE)
 287                 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 288
 289         for (cnt = 0, ap = he->h_addr_list; *ap; ap++, cnt++) {
 290                 sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 291                 if (sockfd < 0) {
 292                         saved_errno = errno;
 293                         continue;
 294                 }
 295
 296                 memset(&sa, 0, sizeof sa);
 297                 sa.sin_family = he->h_addrtype;
 298                 sa.sin_port = htons(nport);
 299                 memcpy(&sa.sin_addr, *ap, he->h_length);
 300
 301                 if (connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 302                         saved_errno = errno;
 303                         fprintf(stderr, "%s[%d: %s]: errno=%s\n",
 304                                 host,
 305                                 cnt,
 306                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr),
 307                                 strerror(saved_errno));
 308                         close(sockfd);
 309                         sockfd = -1;
 310                         continue;
 311                 }
 312                 if (flags & CONNECT_VERBOSE)
 313                         fprintf(stderr, "%s ",
 314                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr));
 315                 break;
 316         }
 317
 318         if (sockfd < 0)
 319                 die("unable to connect a socket (%s)", strerror(saved_errno));
 320
 321         if (flags & CONNECT_VERBOSE)
 322                 fprintf(stderr, "done.\n");
 323
 324         return sockfd;
 325 }
 326
 327 #endif /* NO_IPV6 */
 328
 329
 330 static void git_tcp_connect(int fd[2], char *host, int flags)
 331 {
 332         int sockfd = git_tcp_connect_sock(host, flags);
 333
 334         fd[0] = sockfd;
 335         fd[1] = dup(sockfd);
 336 }
 337
 338
 339 static char *git_proxy_command;
 340
 341 static int git_proxy_command_options(const char *var, const char *value,
 342                 void *cb)
 343 {
 344         if (!strcmp(var, "core.gitproxy")) {
 345                 const char *for_pos;
 346                 int matchlen = -1;
 347                 int hostlen;
 348                 const char *rhost_name = cb;
 349                 int rhost_len = strlen(rhost_name);
 350
 351                 if (git_proxy_command)
 352                         return 0;
 353                 if (!value)
 354                         return config_error_nonbool(var);
 355                 /* [core]
 356                  * ;# matches www.kernel.org as well
 357                  * gitproxy = netcatter-1 for kernel.org
 358                  * gitproxy = netcatter-2 for sample.xz
 359                  * gitproxy = netcatter-default
 360                  */
 361                 for_pos = strstr(value, " for ");
 362                 if (!for_pos)
 363                         /* matches everybody */
 364                         matchlen = strlen(value);
 365                 else {
 366                         hostlen = strlen(for_pos + 5);
 367                         if (rhost_len < hostlen)
 368                                 matchlen = -1;
 369                         else if (!strncmp(for_pos + 5,
 370                                           rhost_name + rhost_len - hostlen,
 371                                           hostlen) &&
 372                                  ((rhost_len == hostlen) ||
 373                                   rhost_name[rhost_len - hostlen -1] == '.'))
 374                                 matchlen = for_pos - value;
 375                         else
 376                                 matchlen = -1;
 377                 }
 378                 if (0 <= matchlen) {
 379                         /* core.gitproxy = none for kernel.org */
 380                         if (matchlen == 4 &&
 381                             !memcmp(value, "none", 4))
 382                                 matchlen = 0;
 383                         git_proxy_command = xmemdupz(value, matchlen);
 384                 }
 385                 return 0;
 386         }
 387
 388         return git_default_config(var, value, cb);
 389 }
 390
 391 static int git_use_proxy(const char *host)
 392 {
 393         git_proxy_command = getenv("GIT_PROXY_COMMAND");
 394         git_config(git_proxy_command_options, (void*)host);
 395         return (git_proxy_command && *git_proxy_command);
 396 }
 397
 398 static struct child_process *git_proxy_connect(int fd[2], char *host)
 399 {
 400         const char *port = STR(DEFAULT_GIT_PORT);
 401         const char **argv;
 402         struct child_process *proxy;
 403
 404         get_host_and_port(&host, &port);
 405
 406         argv = xmalloc(sizeof(*argv) * 4);
 407         argv[0] = git_proxy_command;
 408         argv[1] = host;
 409         argv[2] = port;
 410         argv[3] = NULL;
 411         proxy = xcalloc(1, sizeof(*proxy));
 412         proxy->argv = argv;
 413         proxy->in = -1;
 414         proxy->out = -1;
 415         if (start_command(proxy))
 416                 die("cannot start proxy %s", argv[0]);
 417         fd[0] = proxy->out; /* read from proxy stdout */
 418         fd[1] = proxy->in;  /* write to proxy stdin */
 419         return proxy;
 420 }
 421
 422 #define MAX_CMD_LEN 1024
 423
 424 static char *get_port(char *host)
 425 {
 426         char *end;
 427         char *p = strchr(host, ':');
 428
 429         if (p) {
 430                 long port = strtol(p + 1, &end, 10);
 431                 if (end != p + 1 && *end == '\0' && 0 <= port && port < 65536) {
 432                         *p = '\0';
 433                         return p+1;
 434                 }
 435         }
 436
 437         return NULL;
 438 }
 439
 440 static struct child_process no_fork;
 441
 442 /*
 443  * This returns a dummy child_process if the transport protocol does not
 444  * need fork(2), or a struct child_process object if it does.  Once done,
 445  * finish the connection with finish_connect() with the value returned from
 446  * this function (it is safe to call finish_connect() with NULL to support
 447  * the former case).
 448  *
 449  * If it returns, the connect is successful; it just dies on errors (this
 450  * will hopefully be changed in a libification effort, to return NULL when
 451  * the connection failed).
 452  */
 453 struct child_process *git_connect(int fd[2], const char *url_orig,
 454                                   const char *prog, int flags)
 455 {
 456         char *url;
 457         char *host, *path;
 458         char *end;
 459         int c;
 460         struct child_process *conn = &no_fork;
 461         enum protocol protocol = PROTO_LOCAL;
 462         int free_path = 0;
 463         char *port = NULL;
 464         const char **arg;
 465         struct strbuf cmd;
 466
 467         /* Without this we cannot rely on waitpid() to tell
 468          * what happened to our children.
 469          */
 470         signal(SIGCHLD, SIG_DFL);
 471
 472         if (is_url(url_orig))
 473                 url = url_decode(url_orig);
 474         else
 475                 url = xstrdup(url_orig);
 476
 477         host = strstr(url, "://");
 478         if (host) {
 479                 *host = '\0';
 480                 protocol = get_protocol(url);
 481                 host += 3;
 482                 c = '/';
 483         } else {
 484                 host = url;
 485                 c = ':';
 486         }
 487
 488         /*
 489          * Don't do destructive transforms with git:// as that
 490          * protocol code does '[]' unwrapping of its own.
 491          */
 492         if (host[0] == '[') {
 493                 end = strchr(host + 1, ']');
 494                 if (end) {
 495                         if (protocol != PROTO_GIT) {
 496                                 *end = 0;
 497                                 host++;
 498                         }
 499                         end++;
 500                 } else
 501                         end = host;
 502         } else
 503                 end = host;
 504
 505         path = strchr(end, c);
 506         if (path && !has_dos_drive_prefix(end)) {
 507                 if (c == ':') {
 508                         protocol = PROTO_SSH;
 509                         *path++ = '\0';
 510                 }
 511         } else
 512                 path = end;
 513
 514         if (!path || !*path)
 515                 die("No path specified. See 'man git-pull' for valid url syntax");
 516
 517         /*
 518          * null-terminate hostname and point path to ~ for URL's like this:
 519          *    ssh://host.xz/~user/repo
 520          */
 521         if (protocol != PROTO_LOCAL && host != url) {
 522                 char *ptr = path;
 523                 if (path[1] == '~')
 524                         path++;
 525                 else {
 526                         path = xstrdup(ptr);
 527                         free_path = 1;
 528                 }
 529
 530                 *ptr = '\0';
 531         }
 532
 533         /*
 534          * Add support for ssh port: ssh://host.xy:<port>/...
 535          */
 536         if (protocol == PROTO_SSH && host != url)
 537                 port = get_port(host);
 538
 539         if (protocol == PROTO_GIT) {
 540                 /* These underlying connection commands die() if they
 541                  * cannot connect.
 542                  */
 543                 char *target_host = xstrdup(host);
 544                 if (git_use_proxy(host))
 545                         conn = git_proxy_connect(fd, host);
 546                 else
 547                         git_tcp_connect(fd, host, flags);
 548                 /*
 549                  * Separate original protocol components prog and path
 550                  * from extended host header with a NUL byte.
 551                  *
 552                  * Note: Do not add any other headers here!  Doing so
 553                  * will cause older git-daemon servers to crash.
 554                  */
 555                 packet_write(fd[1],
 556                              "%s %s%chost=%s%c",
 557                              prog, path, 0,
 558                              target_host, 0);
 559                 free(target_host);
 560                 free(url);
 561                 if (free_path)
 562                         free(path);
 563                 return conn;
 564         }
 565
 566         conn = xcalloc(1, sizeof(*conn));
 567
 568         strbuf_init(&cmd, MAX_CMD_LEN);
 569         strbuf_addstr(&cmd, prog);
 570         strbuf_addch(&cmd, ' ');
 571         sq_quote_buf(&cmd, path);
 572         if (cmd.len >= MAX_CMD_LEN)
 573                 die("command line too long");
 574
 575         conn->in = conn->out = -1;
 576         conn->argv = arg = xcalloc(7, sizeof(*arg));
 577         if (protocol == PROTO_SSH) {
 578                 const char *ssh = getenv("GIT_SSH");
 579                 int putty = ssh && strcasestr(ssh, "plink");
 580                 if (!ssh) ssh = "ssh";
 581
 582                 *arg++ = ssh;
 583                 if (putty && !strcasestr(ssh, "tortoiseplink"))
 584                         *arg++ = "-batch";
 585                 if (port) {
 586                         /* P is for PuTTY, p is for OpenSSH */
 587                         *arg++ = putty ? "-P" : "-p";
 588                         *arg++ = port;
 589                 }
 590                 *arg++ = host;
 591         }
 592         else {
 593                 /* remove repo-local variables from the environment */
 594                 conn->env = local_repo_env;
 595                 conn->use_shell = 1;
 596         }
 597         *arg++ = cmd.buf;
 598         *arg = NULL;
 599
 600         if (start_command(conn))
 601                 die("unable to fork");
 602
 603         fd[0] = conn->out; /* read from child's stdout */
 604         fd[1] = conn->in;  /* write to child's stdin */
 605         strbuf_release(&cmd);
 606         free(url);
 607         if (free_path)
 608                 free(path);
 609         return conn;
 610 }
 611
 612 int git_connection_is_socket(struct child_process *conn)
 613 {
 614         return conn == &no_fork;
 615 }
 616
 617 int finish_connect(struct child_process *conn)
 618 {
 619         int code;
 620         if (!conn || git_connection_is_socket(conn))
 621                 return 0;
 622
 623         code = finish_command(conn);
 624         free(conn->argv);
 625         free(conn);
 626         return code;
 627 }
 628
 629 char *git_getpass(const char *prompt)
 630 {
 631         const char *askpass;
 632         struct child_process pass;
 633         const char *args[3];
 634         static struct strbuf buffer = STRBUF_INIT;
 635
 636         askpass = getenv("GIT_ASKPASS");
 637         if (!askpass)
 638                 askpass = askpass_program;
 639         if (!askpass)
 640                 askpass = getenv("SSH_ASKPASS");
 641         if (!askpass || !(*askpass)) {
 642                 char *result = getpass(prompt);
 643                 if (!result)
 644                         die_errno("Could not read password");
 645                 return result;
 646         }
 647
 648         args[0] = askpass;
 649         args[1] = prompt;
 650         args[2] = NULL;
 651
 652         memset(&pass, 0, sizeof(pass));
 653         pass.argv = args;
 654         pass.out = -1;
 655
 656         if (start_command(&pass))
 657                 exit(1);
 658
 659         strbuf_reset(&buffer);
 660         if (strbuf_read(&buffer, pass.out, 20) < 0)
 661                 die("failed to read password from %s\n", askpass);
 662
 663         close(pass.out);
 664
 665         if (finish_command(&pass))
 666                 exit(1);
 667
 668         strbuf_setlen(&buffer, strcspn(buffer.buf, "\r\n"));
 669
 670         return buffer.buf;
 671 }