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
   9 static char *server_capabilities;
  10
  11 static int check_ref(const char *name, int len, unsigned int flags)
  12 {
  13         if (!flags)
  14                 return 1;
  15
  16         if (len < 5 || memcmp(name, "refs/", 5))
  17                 return 0;
  18
  19         /* Skip the "refs/" part */
  20         name += 5;
  21         len -= 5;
  22
  23         /* REF_NORMAL means that we don't want the magic fake tag refs */
  24         if ((flags & REF_NORMAL) && check_ref_format(name) < 0)
  25                 return 0;
  26
  27         /* REF_HEADS means that we want regular branch heads */
  28         if ((flags & REF_HEADS) && !memcmp(name, "heads/", 6))
  29                 return 1;
  30
  31         /* REF_TAGS means that we want tags */
  32         if ((flags & REF_TAGS) && !memcmp(name, "tags/", 5))
  33                 return 1;
  34
  35         /* All type bits clear means that we are ok with anything */
  36         return !(flags & ~REF_NORMAL);
  37 }
  38
  39 /*
  40  * Read all the refs from the other end
  41  */
  42 struct ref **get_remote_heads(int in, struct ref **list,
  43                               int nr_match, char **match,
  44                               unsigned int flags)
  45 {
  46         *list = NULL;
  47         for (;;) {
  48                 struct ref *ref;
  49                 unsigned char old_sha1[20];
  50                 static char buffer[1000];
  51                 char *name;
  52                 int len, name_len;
  53
  54                 len = packet_read_line(in, buffer, sizeof(buffer));
  55                 if (!len)
  56                         break;
  57                 if (buffer[len-1] == '\n')
  58                         buffer[--len] = 0;
  59
  60                 if (len < 42 || get_sha1_hex(buffer, old_sha1) || buffer[40] != ' ')
  61                         die("protocol error: expected sha/ref, got '%s'", buffer);
  62                 name = buffer + 41;
  63
  64                 name_len = strlen(name);
  65                 if (len != name_len + 41) {
  66                         if (server_capabilities)
  67                                 free(server_capabilities);
  68                         server_capabilities = xstrdup(name + name_len + 1);
  69                 }
  70
  71                 if (!check_ref(name, name_len, flags))
  72                         continue;
  73                 if (nr_match && !path_match(name, nr_match, match))
  74                         continue;
  75                 ref = xcalloc(1, sizeof(*ref) + len - 40);
  76                 hashcpy(ref->old_sha1, old_sha1);
  77                 memcpy(ref->name, buffer + 41, len - 40);
  78                 *list = ref;
  79                 list = &ref->next;
  80         }
  81         return list;
  82 }
  83
  84 int server_supports(const char *feature)
  85 {
  86         return server_capabilities &&
  87                 strstr(server_capabilities, feature) != NULL;
  88 }
  89
  90 int get_ack(int fd, unsigned char *result_sha1)
  91 {
  92         static char line[1000];
  93         int len = packet_read_line(fd, line, sizeof(line));
  94
  95         if (!len)
  96                 die("git-fetch-pack: expected ACK/NAK, got EOF");
  97         if (line[len-1] == '\n')
  98                 line[--len] = 0;
  99         if (!strcmp(line, "NAK"))
 100                 return 0;
 101         if (!prefixcmp(line, "ACK ")) {
 102                 if (!get_sha1_hex(line+4, result_sha1)) {
 103                         if (strstr(line+45, "continue"))
 104                                 return 2;
 105                         return 1;
 106                 }
 107         }
 108         die("git-fetch_pack: expected ACK/NAK, got '%s'", line);
 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         die("I don't handle protocol '%s'", name);
 149 }
 150
 151 #define STR_(s) # s
 152 #define STR(s)  STR_(s)
 153
 154 #ifndef NO_IPV6
 155
 156 static const char *ai_name(const struct addrinfo *ai)
 157 {
 158         static char addr[INET_ADDRSTRLEN];
 159         if ( AF_INET == ai->ai_family ) {
 160                 struct sockaddr_in *in;
 161                 in = (struct sockaddr_in *)ai->ai_addr;
 162                 inet_ntop(ai->ai_family, &in->sin_addr, addr, sizeof(addr));
 163         } else if ( AF_INET6 == ai->ai_family ) {
 164                 struct sockaddr_in6 *in;
 165                 in = (struct sockaddr_in6 *)ai->ai_addr;
 166                 inet_ntop(ai->ai_family, &in->sin6_addr, addr, sizeof(addr));
 167         } else {
 168                 strcpy(addr, "(unknown)");
 169         }
 170         return addr;
 171 }
 172
 173 /*
 174  * Returns a connected socket() fd, or else die()s.
 175  */
 176 static int git_tcp_connect_sock(char *host, int flags)
 177 {
 178         int sockfd = -1, saved_errno = 0;
 179         char *colon, *end;
 180         const char *port = STR(DEFAULT_GIT_PORT);
 181         struct addrinfo hints, *ai0, *ai;
 182         int gai;
 183         int cnt = 0;
 184
 185         if (host[0] == '[') {
 186                 end = strchr(host + 1, ']');
 187                 if (end) {
 188                         *end = 0;
 189                         end++;
 190                         host++;
 191                 } else
 192                         end = host;
 193         } else
 194                 end = host;
 195         colon = strchr(end, ':');
 196
 197         if (colon) {
 198                 *colon = 0;
 199                 port = colon + 1;
 200                 if (!*port)
 201                         port = "<none>";
 202         }
 203
 204         memset(&hints, 0, sizeof(hints));
 205         hints.ai_socktype = SOCK_STREAM;
 206         hints.ai_protocol = IPPROTO_TCP;
 207
 208         if (flags & CONNECT_VERBOSE)
 209                 fprintf(stderr, "Looking up %s ... ", host);
 210
 211         gai = getaddrinfo(host, port, &hints, &ai);
 212         if (gai)
 213                 die("Unable to look up %s (port %s) (%s)", host, port, gai_strerror(gai));
 214
 215         if (flags & CONNECT_VERBOSE)
 216                 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 217
 218         for (ai0 = ai; ai; ai = ai->ai_next) {
 219                 sockfd = socket(ai->ai_family,
 220                                 ai->ai_socktype, ai->ai_protocol);
 221                 if (sockfd < 0) {
 222                         saved_errno = errno;
 223                         continue;
 224                 }
 225                 if (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
 226                         saved_errno = errno;
 227                         fprintf(stderr, "%s[%d: %s]: net=%s, errno=%s\n",
 228                                 host,
 229                                 cnt,
 230                                 ai_name(ai),
 231                                 hstrerror(h_errno),
 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]: net=%s, errno=%s\n",
 319                                 host,
 320                                 cnt,
 321                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr),
 322                                 hstrerror(h_errno),
 323                                 strerror(saved_errno));
 324                         close(sockfd);
 325                         sockfd = -1;
 326                         continue;
 327                 }
 328                 if (flags & CONNECT_VERBOSE)
 329                         fprintf(stderr, "%s ",
 330                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr));
 331                 break;
 332         }
 333
 334         if (sockfd < 0)
 335                 die("unable to connect a socket (%s)", strerror(saved_errno));
 336
 337         if (flags & CONNECT_VERBOSE)
 338                 fprintf(stderr, "done.\n");
 339
 340         return sockfd;
 341 }
 342
 343 #endif /* NO_IPV6 */
 344
 345
 346 static void git_tcp_connect(int fd[2], char *host, int flags)
 347 {
 348         int sockfd = git_tcp_connect_sock(host, flags);
 349
 350         fd[0] = sockfd;
 351         fd[1] = dup(sockfd);
 352 }
 353
 354
 355 static char *git_proxy_command;
 356 static const char *rhost_name;
 357 static int rhost_len;
 358
 359 static int git_proxy_command_options(const char *var, const char *value)
 360 {
 361         if (!strcmp(var, "core.gitproxy")) {
 362                 const char *for_pos;
 363                 int matchlen = -1;
 364                 int hostlen;
 365
 366                 if (git_proxy_command)
 367                         return 0;
 368                 /* [core]
 369                  * ;# matches www.kernel.org as well
 370                  * gitproxy = netcatter-1 for kernel.org
 371                  * gitproxy = netcatter-2 for sample.xz
 372                  * gitproxy = netcatter-default
 373                  */
 374                 for_pos = strstr(value, " for ");
 375                 if (!for_pos)
 376                         /* matches everybody */
 377                         matchlen = strlen(value);
 378                 else {
 379                         hostlen = strlen(for_pos + 5);
 380                         if (rhost_len < hostlen)
 381                                 matchlen = -1;
 382                         else if (!strncmp(for_pos + 5,
 383                                           rhost_name + rhost_len - hostlen,
 384                                           hostlen) &&
 385                                  ((rhost_len == hostlen) ||
 386                                   rhost_name[rhost_len - hostlen -1] == '.'))
 387                                 matchlen = for_pos - value;
 388                         else
 389                                 matchlen = -1;
 390                 }
 391                 if (0 <= matchlen) {
 392                         /* core.gitproxy = none for kernel.org */
 393                         if (matchlen == 4 &&
 394                             !memcmp(value, "none", 4))
 395                                 matchlen = 0;
 396                         git_proxy_command = xmalloc(matchlen + 1);
 397                         memcpy(git_proxy_command, value, matchlen);
 398                         git_proxy_command[matchlen] = 0;
 399                 }
 400                 return 0;
 401         }
 402
 403         return git_default_config(var, value);
 404 }
 405
 406 static int git_use_proxy(const char *host)
 407 {
 408         rhost_name = host;
 409         rhost_len = strlen(host);
 410         git_proxy_command = getenv("GIT_PROXY_COMMAND");
 411         git_config(git_proxy_command_options);
 412         rhost_name = NULL;
 413         return (git_proxy_command && *git_proxy_command);
 414 }
 415
 416 static void git_proxy_connect(int fd[2], char *host)
 417 {
 418         const char *port = STR(DEFAULT_GIT_PORT);
 419         char *colon, *end;
 420         const char *argv[4];
 421         struct child_process proxy;
 422
 423         if (host[0] == '[') {
 424                 end = strchr(host + 1, ']');
 425                 if (end) {
 426                         *end = 0;
 427                         end++;
 428                         host++;
 429                 } else
 430                         end = host;
 431         } else
 432                 end = host;
 433         colon = strchr(end, ':');
 434
 435         if (colon) {
 436                 *colon = 0;
 437                 port = colon + 1;
 438         }
 439
 440         argv[0] = git_proxy_command;
 441         argv[1] = host;
 442         argv[2] = port;
 443         argv[3] = NULL;
 444         memset(&proxy, 0, sizeof(proxy));
 445         proxy.argv = argv;
 446         proxy.in = -1;
 447         proxy.out = -1;
 448         if (start_command(&proxy))
 449                 die("cannot start proxy %s", argv[0]);
 450         fd[0] = proxy.out; /* read from proxy stdout */
 451         fd[1] = proxy.in;  /* write to proxy stdin */
 452 }
 453
 454 #define MAX_CMD_LEN 1024
 455
 456 /*
 457  * This returns 0 if the transport protocol does not need fork(2),
 458  * or a process id if it does.  Once done, finish the connection
 459  * with finish_connect() with the value returned from this function
 460  * (it is safe to call finish_connect() with 0 to support the former
 461  * case).
 462  *
 463  * Does not return a negative value on error; it just dies.
 464  */
 465 pid_t git_connect(int fd[2], char *url, const char *prog, int flags)
 466 {
 467         char *host, *path = url;
 468         char *end;
 469         int c;
 470         int pipefd[2][2];
 471         pid_t pid;
 472         enum protocol protocol = PROTO_LOCAL;
 473         int free_path = 0;
 474
 475         /* Without this we cannot rely on waitpid() to tell
 476          * what happened to our children.
 477          */
 478         signal(SIGCHLD, SIG_DFL);
 479
 480         host = strstr(url, "://");
 481         if(host) {
 482                 *host = '\0';
 483                 protocol = get_protocol(url);
 484                 host += 3;
 485                 c = '/';
 486         } else {
 487                 host = url;
 488                 c = ':';
 489         }
 490
 491         if (host[0] == '[') {
 492                 end = strchr(host + 1, ']');
 493                 if (end) {
 494                         *end = 0;
 495                         end++;
 496                         host++;
 497                 } else
 498                         end = host;
 499         } else
 500                 end = host;
 501
 502         path = strchr(end, c);
 503         if (c == ':') {
 504                 if (path) {
 505                         protocol = PROTO_SSH;
 506                         *path++ = '\0';
 507                 } else
 508                         path = host;
 509         }
 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         if (protocol == PROTO_GIT) {
 531                 /* These underlying connection commands die() if they
 532                  * cannot connect.
 533                  */
 534                 char *target_host = xstrdup(host);
 535                 if (git_use_proxy(host))
 536                         git_proxy_connect(fd, host);
 537                 else
 538                         git_tcp_connect(fd, host, flags);
 539                 /*
 540                  * Separate original protocol components prog and path
 541                  * from extended components with a NUL byte.
 542                  */
 543                 packet_write(fd[1],
 544                              "%s %s%chost=%s%c",
 545                              prog, path, 0,
 546                              target_host, 0);
 547                 free(target_host);
 548                 if (free_path)
 549                         free(path);
 550                 return 0;
 551         }
 552
 553         if (pipe(pipefd[0]) < 0 || pipe(pipefd[1]) < 0)
 554                 die("unable to create pipe pair for communication");
 555         pid = fork();
 556         if (pid < 0)
 557                 die("unable to fork");
 558         if (!pid) {
 559                 char command[MAX_CMD_LEN];
 560                 char *posn = command;
 561                 int size = MAX_CMD_LEN;
 562                 int of = 0;
 563
 564                 of |= add_to_string(&posn, &size, prog, 0);
 565                 of |= add_to_string(&posn, &size, " ", 0);
 566                 of |= add_to_string(&posn, &size, path, 1);
 567
 568                 if (of)
 569                         die("command line too long");
 570
 571                 dup2(pipefd[1][0], 0);
 572                 dup2(pipefd[0][1], 1);
 573                 close(pipefd[0][0]);
 574                 close(pipefd[0][1]);
 575                 close(pipefd[1][0]);
 576                 close(pipefd[1][1]);
 577                 if (protocol == PROTO_SSH) {
 578                         const char *ssh, *ssh_basename;
 579                         ssh = getenv("GIT_SSH");
 580                         if (!ssh) ssh = "ssh";
 581                         ssh_basename = strrchr(ssh, '/');
 582                         if (!ssh_basename)
 583                                 ssh_basename = ssh;
 584                         else
 585                                 ssh_basename++;
 586                         execlp(ssh, ssh_basename, host, command, NULL);
 587                 }
 588                 else {
 589                         unsetenv(ALTERNATE_DB_ENVIRONMENT);
 590                         unsetenv(DB_ENVIRONMENT);
 591                         unsetenv(GIT_DIR_ENVIRONMENT);
 592                         unsetenv(GRAFT_ENVIRONMENT);
 593                         unsetenv(INDEX_ENVIRONMENT);
 594                         execlp("sh", "sh", "-c", command, NULL);
 595                 }
 596                 die("exec failed");
 597         }
 598         fd[0] = pipefd[0][0];
 599         fd[1] = pipefd[1][1];
 600         close(pipefd[0][1]);
 601         close(pipefd[1][0]);
 602         if (free_path)
 603                 free(path);
 604         return pid;
 605 }
 606
 607 int finish_connect(pid_t pid)
 608 {
 609         if (pid == 0)
 610                 return 0;
 611
 612         while (waitpid(pid, NULL, 0) < 0) {
 613                 if (errno != EINTR)
 614                         return -1;
 615         }
 616         return 0;
 617 }