git/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 "spawn-pipe.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 /*
  41  * Read all the refs from the other end
  42  */
  43 struct ref **get_remote_heads(int in, struct ref **list,
  44                               int nr_match, char **match,
  45                               unsigned int flags)
  46 {
  47         *list = NULL;
  48         for (;;) {
  49                 struct ref *ref;
  50                 unsigned char old_sha1[20];
  51                 static char buffer[1000];
  52                 char *name;
  53                 int len, name_len;
  54
  55                 len = packet_read_line(in, buffer, sizeof(buffer));
  56                 if (!len)
  57                         break;
  58                 if (buffer[len-1] == '\n')
  59                         buffer[--len] = 0;
  60
  61                 if (len < 42 || get_sha1_hex(buffer, old_sha1) || buffer[40] != ' ')
  62                         die("protocol error: expected sha/ref, got '%s'", buffer);
  63                 name = buffer + 41;
  64
  65                 name_len = strlen(name);
  66                 if (len != name_len + 41) {
  67                         if (server_capabilities)
  68                                 free(server_capabilities);
  69                         server_capabilities = xstrdup(name + name_len + 1);
  70                 }
  71
  72                 if (!check_ref(name, name_len, flags))
  73                         continue;
  74                 if (nr_match && !path_match(name, nr_match, match))
  75                         continue;
  76                 ref = alloc_ref(len - 40);
  77                 hashcpy(ref->old_sha1, old_sha1);
  78                 memcpy(ref->name, buffer + 41, len - 40);
  79                 *list = ref;
  80                 list = &ref->next;
  81         }
  82         return list;
  83 }
  84
  85 int server_supports(const char *feature)
  86 {
  87         return server_capabilities &&
  88                 strstr(server_capabilities, feature) != NULL;
  89 }
  90
  91 int get_ack(int fd, unsigned char *result_sha1)
  92 {
  93         static char line[1000];
  94         int len = packet_read_line(fd, line, sizeof(line));
  95
  96         if (!len)
  97                 die("git-fetch-pack: expected ACK/NAK, got EOF");
  98         if (line[len-1] == '\n')
  99                 line[--len] = 0;
 100         if (!strcmp(line, "NAK"))
 101                 return 0;
 102         if (!prefixcmp(line, "ACK ")) {
 103                 if (!get_sha1_hex(line+4, result_sha1)) {
 104                         if (strstr(line+45, "continue"))
 105                                 return 2;
 106                         return 1;
 107                 }
 108         }
 109         die("git-fetch_pack: expected ACK/NAK, got '%s'", line);
 110 }
 111
 112 int path_match(const char *path, int nr, char **match)
 113 {
 114         int i;
 115         int pathlen = strlen(path);
 116
 117         for (i = 0; i < nr; i++) {
 118                 char *s = match[i];
 119                 int len = strlen(s);
 120
 121                 if (!len || len > pathlen)
 122                         continue;
 123                 if (memcmp(path + pathlen - len, s, len))
 124                         continue;
 125                 if (pathlen > len && path[pathlen - len - 1] != '/')
 126                         continue;
 127                 *s = 0;
 128                 return (i + 1);
 129         }
 130         return 0;
 131 }
 132
 133 enum protocol {
 134         PROTO_LOCAL = 1,
 135         PROTO_SSH,
 136         PROTO_GIT,
 137 };
 138
 139 static enum protocol get_protocol(const char *name)
 140 {
 141         if (!strcmp(name, "ssh"))
 142                 return PROTO_SSH;
 143         if (!strcmp(name, "git"))
 144                 return PROTO_GIT;
 145         if (!strcmp(name, "git+ssh"))
 146                 return PROTO_SSH;
 147         if (!strcmp(name, "ssh+git"))
 148                 return PROTO_SSH;
 149         die("I don't handle protocol '%s'", name);
 150 }
 151
 152 #define STR_(s) # s
 153 #define STR(s)  STR_(s)
 154
 155 #ifndef NO_IPV6
 156
 157 static const char *ai_name(const struct addrinfo *ai)
 158 {
 159         static char addr[INET_ADDRSTRLEN];
 160         if ( AF_INET == ai->ai_family ) {
 161                 struct sockaddr_in *in;
 162                 in = (struct sockaddr_in *)ai->ai_addr;
 163                 inet_ntop(ai->ai_family, &in->sin_addr, addr, sizeof(addr));
 164         } else if ( AF_INET6 == ai->ai_family ) {
 165                 struct sockaddr_in6 *in;
 166                 in = (struct sockaddr_in6 *)ai->ai_addr;
 167                 inet_ntop(ai->ai_family, &in->sin6_addr, addr, sizeof(addr));
 168         } else {
 169                 strcpy(addr, "(unknown)");
 170         }
 171         return addr;
 172 }
 173
 174 /*
 175  * Returns a connected socket() fd, or else die()s.
 176  */
 177 static int git_tcp_connect_sock(char *host, int flags)
 178 {
 179         int sockfd = -1, saved_errno = 0;
 180         char *colon, *end;
 181         const char *port = STR(DEFAULT_GIT_PORT);
 182         struct addrinfo hints, *ai0, *ai;
 183         int gai;
 184         int cnt = 0;
 185
 186         if (host[0] == '[') {
 187                 end = strchr(host + 1, ']');
 188                 if (end) {
 189                         *end = 0;
 190                         end++;
 191                         host++;
 192                 } else
 193                         end = host;
 194         } else
 195                 end = host;
 196         colon = strchr(end, ':');
 197
 198         if (colon) {
 199                 *colon = 0;
 200                 port = colon + 1;
 201                 if (!*port)
 202                         port = "<none>";
 203         }
 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) {
 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         char *colon, *end;
 262         char *port = STR(DEFAULT_GIT_PORT), *ep;
 263         struct hostent *he;
 264         struct sockaddr_in sa;
 265         char **ap;
 266         unsigned int nport;
 267         int cnt;
 268
 269         if (host[0] == '[') {
 270                 end = strchr(host + 1, ']');
 271                 if (end) {
 272                         *end = 0;
 273                         end++;
 274                         host++;
 275                 } else
 276                         end = host;
 277         } else
 278                 end = host;
 279         colon = strchr(end, ':');
 280
 281         if (colon) {
 282                 *colon = 0;
 283                 port = colon + 1;
 284         }
 285
 286         if (flags & CONNECT_VERBOSE)
 287                 fprintf(stderr, "Looking up %s ... ", host);
 288
 289         he = gethostbyname(host);
 290         if (!he)
 291                 die("Unable to look up %s (%s)", host, hstrerror(h_errno));
 292         nport = strtoul(port, &ep, 10);
 293         if ( ep == port || *ep ) {
 294                 /* Not numeric */
 295                 struct servent *se = getservbyname(port,"tcp");
 296                 if ( !se )
 297                         die("Unknown port %s\n", port);
 298                 nport = se->s_port;
 299         }
 300
 301         if (flags & CONNECT_VERBOSE)
 302                 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 303
 304         for (cnt = 0, ap = he->h_addr_list; *ap; ap++, cnt++) {
 305                 sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 306                 if (sockfd < 0) {
 307                         saved_errno = errno;
 308                         continue;
 309                 }
 310
 311                 memset(&sa, 0, sizeof sa);
 312                 sa.sin_family = he->h_addrtype;
 313                 sa.sin_port = htons(nport);
 314                 memcpy(&sa.sin_addr, *ap, he->h_length);
 315
 316                 if (connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 317                         saved_errno = errno;
 318                         fprintf(stderr, "%s[%d: %s]: errno=%s\n",
 319                                 host,
 320                                 cnt,
 321                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr),
 322                                 strerror(saved_errno));
 323                         close(sockfd);
 324                         sockfd = -1;
 325                         continue;
 326                 }
 327                 if (flags & CONNECT_VERBOSE)
 328                         fprintf(stderr, "%s ",
 329                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr));
 330                 break;
 331         }
 332
 333         if (sockfd < 0)
 334                 die("unable to connect a socket (%s)", strerror(saved_errno));
 335
 336         if (flags & CONNECT_VERBOSE)
 337                 fprintf(stderr, "done.\n");
 338
 339         return sockfd;
 340 }
 341
 342 #endif /* NO_IPV6 */
 343
 344
 345 static void git_tcp_connect(int fd[2], char *host, int flags)
 346 {
 347 #ifndef __MINGW32__
 348         int sockfd = git_tcp_connect_sock(host, flags);
 349 #else
 350         int sockfd;
 351         WSADATA wsa;
 352
 353         if (WSAStartup(MAKEWORD(2,2), &wsa))
 354                 die("unable to initialize winsock subsystem, error %d",
 355                         WSAGetLastError());
 356         atexit((void(*)(void)) WSACleanup);
 357
 358         sockfd = git_tcp_connect_sock(host, flags);
 359         /* convert into a file descriptor */
 360         if ((sockfd = _open_osfhandle(sockfd, O_RDWR|O_BINARY)) < 0)
 361                 die("unable to make a socket file descriptor: %s",
 362                         strerror(errno));
 363 #endif
 364
 365         fd[0] = sockfd;
 366         fd[1] = dup(sockfd);
 367 }
 368
 369
 370 static char *git_proxy_command;
 371 static const char *rhost_name;
 372 static int rhost_len;
 373
 374 static int git_proxy_command_options(const char *var, const char *value)
 375 {
 376         if (!strcmp(var, "core.gitproxy")) {
 377                 const char *for_pos;
 378                 int matchlen = -1;
 379                 int hostlen;
 380
 381                 if (git_proxy_command)
 382                         return 0;
 383                 /* [core]
 384                  * ;# matches www.kernel.org as well
 385                  * gitproxy = netcatter-1 for kernel.org
 386                  * gitproxy = netcatter-2 for sample.xz
 387                  * gitproxy = netcatter-default
 388                  */
 389                 for_pos = strstr(value, " for ");
 390                 if (!for_pos)
 391                         /* matches everybody */
 392                         matchlen = strlen(value);
 393                 else {
 394                         hostlen = strlen(for_pos + 5);
 395                         if (rhost_len < hostlen)
 396                                 matchlen = -1;
 397                         else if (!strncmp(for_pos + 5,
 398                                           rhost_name + rhost_len - hostlen,
 399                                           hostlen) &&
 400                                  ((rhost_len == hostlen) ||
 401                                   rhost_name[rhost_len - hostlen -1] == '.'))
 402                                 matchlen = for_pos - value;
 403                         else
 404                                 matchlen = -1;
 405                 }
 406                 if (0 <= matchlen) {
 407                         /* core.gitproxy = none for kernel.org */
 408                         if (matchlen == 4 &&
 409                             !memcmp(value, "none", 4))
 410                                 matchlen = 0;
 411                         git_proxy_command = xmalloc(matchlen + 1);
 412                         memcpy(git_proxy_command, value, matchlen);
 413                         git_proxy_command[matchlen] = 0;
 414                 }
 415                 return 0;
 416         }
 417
 418         return git_default_config(var, value);
 419 }
 420
 421 static int git_use_proxy(const char *host)
 422 {
 423         rhost_name = host;
 424         rhost_len = strlen(host);
 425         git_proxy_command = getenv("GIT_PROXY_COMMAND");
 426         git_config(git_proxy_command_options);
 427         rhost_name = NULL;
 428         return (git_proxy_command && *git_proxy_command);
 429 }
 430
 431 static void git_proxy_connect(int fd[2], char *host)
 432 {
 433         const char *port = STR(DEFAULT_GIT_PORT);
 434         char *colon, *end;
 435         const char *argv[4];
 436         struct child_process proxy;
 437
 438         if (host[0] == '[') {
 439                 end = strchr(host + 1, ']');
 440                 if (end) {
 441                         *end = 0;
 442                         end++;
 443                         host++;
 444                 } else
 445                         end = host;
 446         } else
 447                 end = host;
 448         colon = strchr(end, ':');
 449
 450         if (colon) {
 451                 *colon = 0;
 452                 port = colon + 1;
 453         }
 454
 455         argv[0] = git_proxy_command;
 456         argv[1] = host;
 457         argv[2] = port;
 458         argv[3] = NULL;
 459         memset(&proxy, 0, sizeof(proxy));
 460         proxy.argv = argv;
 461         proxy.in = -1;
 462         proxy.out = -1;
 463         if (start_command(&proxy))
 464                 die("cannot start proxy %s", argv[0]);
 465         fd[0] = proxy.out; /* read from proxy stdout */
 466         fd[1] = proxy.in;  /* write to proxy stdin */
 467 }
 468
 469 #define MAX_CMD_LEN 1024
 470
 471 /*
 472  * This returns 0 if the transport protocol does not need fork(2),
 473  * or a process id if it does.  Once done, finish the connection
 474  * with finish_connect() with the value returned from this function
 475  * (it is safe to call finish_connect() with 0 to support the former
 476  * case).
 477  *
 478  * Does not return a negative value on error; it just dies.
 479  */
 480 pid_t git_connect(int fd[2], char *url, const char *prog, int flags)
 481 {
 482         char *host, *path = url;
 483         char *end;
 484         int c;
 485         int pipefd[2][2];
 486         pid_t pid;
 487         enum protocol protocol = PROTO_LOCAL;
 488         int free_path = 0;
 489
 490         /* Without this we cannot rely on waitpid() to tell
 491          * what happened to our children.
 492          */
 493         signal(SIGCHLD, SIG_DFL);
 494
 495         host = strstr(url, "://");
 496         if(host) {
 497                 *host = '\0';
 498                 protocol = get_protocol(url);
 499                 host += 3;
 500                 c = '/';
 501         } else {
 502                 host = url;
 503                 c = ':';
 504         }
 505
 506         if (host[0] == '[') {
 507                 end = strchr(host + 1, ']');
 508                 if (end) {
 509                         *end = 0;
 510                         end++;
 511                         host++;
 512                 } else
 513                         end = host;
 514         } else
 515                 end = host;
 516
 517         path = strchr(end, c);
 518         if (c == ':') {
 519                 /* host must have at least 2 chars to catch DOS C:/path */
 520                 if (path && path - end > 1) {
 521                         protocol = PROTO_SSH;
 522                         *path++ = '\0';
 523                 } else
 524                         path = host;
 525         }
 526
 527         if (!path || !*path)
 528                 die("No path specified. See 'man git-pull' for valid url syntax");
 529
 530         /*
 531          * null-terminate hostname and point path to ~ for URL's like this:
 532          *    ssh://host.xz/~user/repo
 533          */
 534         if (protocol != PROTO_LOCAL && host != url) {
 535                 char *ptr = path;
 536                 if (path[1] == '~')
 537                         path++;
 538                 else {
 539                         path = xstrdup(ptr);
 540                         free_path = 1;
 541                 }
 542
 543                 *ptr = '\0';
 544         }
 545
 546         if (protocol == PROTO_GIT) {
 547                 /* These underlying connection commands die() if they
 548                  * cannot connect.
 549                  */
 550                 char *target_host = xstrdup(host);
 551                 if (git_use_proxy(host))
 552                         git_proxy_connect(fd, host);
 553                 else
 554                         git_tcp_connect(fd, host, flags);
 555                 /*
 556                  * Separate original protocol components prog and path
 557                  * from extended components with a NUL byte.
 558                  */
 559                 packet_write(fd[1],
 560                              "%s %s%chost=%s%c",
 561                              prog, path, 0,
 562                              target_host, 0);
 563                 free(target_host);
 564                 if (free_path)
 565                         free(path);
 566                 return 0;
 567         }
 568
 569         if (pipe(pipefd[0]) < 0 || pipe(pipefd[1]) < 0)
 570                 die("unable to create pipe pair for communication");
 571
 572         char command[MAX_CMD_LEN];
 573         char *posn = command;
 574         int size = MAX_CMD_LEN;
 575         int of = 0;
 576
 577         of |= add_to_string(&posn, &size, prog, 0);
 578         of |= add_to_string(&posn, &size, " ", 0);
 579         of |= add_to_string(&posn, &size, path, 1);
 580
 581         if (of)
 582                 die("command line too long");
 583
 584         if (protocol == PROTO_SSH) {
 585                 const char *argv[] = { NULL, host, command, NULL };
 586                 const char *ssh = getenv("GIT_SSH");
 587                 if (!ssh) ssh = "ssh";
 588                 pid = spawnvpe_pipe(ssh, argv, environ, pipefd[1], pipefd[0]);
 589         }
 590         else {
 591                 const char *argv[] = { NULL, "-c", command, NULL };
 592                 const char **env = copy_environ();
 593                 env_unsetenv(env, ALTERNATE_DB_ENVIRONMENT);
 594                 env_unsetenv(env, DB_ENVIRONMENT);
 595                 env_unsetenv(env, GIT_DIR_ENVIRONMENT);
 596                 env_unsetenv(env, GIT_WORK_TREE_ENVIRONMENT);
 597                 env_unsetenv(env, GRAFT_ENVIRONMENT);
 598                 env_unsetenv(env, INDEX_ENVIRONMENT);
 599                 pid = spawnvpe_pipe("sh", argv, env, pipefd[1], pipefd[0]);
 600         }
 601         if (pid < 0)
 602                 die("unable to fork");
 603         fd[0] = pipefd[0][0];
 604         fd[1] = pipefd[1][1];
 605         if (free_path)
 606                 free(path);
 607         return pid;
 608 }
 609
 610 int finish_connect(pid_t pid)
 611 {
 612         if (pid == 0)
 613                 return 0;
 614
 615         while (waitpid(pid, NULL, 0) < 0) {
 616                 if (errno != EINTR)
 617                         return -1;
 618         }
 619         return 0;
 620 }