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]: errno=%s\n",
 228                                 host,
 229                                 cnt,
 230                                 ai_name(ai),
 231                                 strerror(saved_errno));
 232                         close(sockfd);
 233                         sockfd = -1;
 234                         continue;
 235                 }
 236                 if (flags & CONNECT_VERBOSE)
 237                         fprintf(stderr, "%s ", ai_name(ai));
 238                 break;
 239         }
 240
 241         freeaddrinfo(ai0);
 242
 243         if (sockfd < 0)
 244                 die("unable to connect a socket (%s)", strerror(saved_errno));
 245
 246         if (flags & CONNECT_VERBOSE)
 247                 fprintf(stderr, "done.\n");
 248
 249         return sockfd;
 250 }
 251
 252 #else /* NO_IPV6 */
 253
 254 /*
 255  * Returns a connected socket() fd, or else die()s.
 256  */
 257 static int git_tcp_connect_sock(char *host, int flags)
 258 {
 259         int sockfd = -1, saved_errno = 0;
 260         char *colon, *end;
 261         char *port = STR(DEFAULT_GIT_PORT), *ep;
 262         struct hostent *he;
 263         struct sockaddr_in sa;
 264         char **ap;
 265         unsigned int nport;
 266         int cnt;
 267
 268         if (host[0] == '[') {
 269                 end = strchr(host + 1, ']');
 270                 if (end) {
 271                         *end = 0;
 272                         end++;
 273                         host++;
 274                 } else
 275                         end = host;
 276         } else
 277                 end = host;
 278         colon = strchr(end, ':');
 279
 280         if (colon) {
 281                 *colon = 0;
 282                 port = colon + 1;
 283         }
 284
 285         if (flags & CONNECT_VERBOSE)
 286                 fprintf(stderr, "Looking up %s ... ", host);
 287
 288         he = gethostbyname(host);
 289         if (!he)
 290                 die("Unable to look up %s (%s)", host, hstrerror(h_errno));
 291         nport = strtoul(port, &ep, 10);
 292         if ( ep == port || *ep ) {
 293                 /* Not numeric */
 294                 struct servent *se = getservbyname(port,"tcp");
 295                 if ( !se )
 296                         die("Unknown port %s\n", port);
 297                 nport = se->s_port;
 298         }
 299
 300         if (flags & CONNECT_VERBOSE)
 301                 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 302
 303         for (cnt = 0, ap = he->h_addr_list; *ap; ap++, cnt++) {
 304                 sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 305                 if (sockfd < 0) {
 306                         saved_errno = errno;
 307                         continue;
 308                 }
 309
 310                 memset(&sa, 0, sizeof sa);
 311                 sa.sin_family = he->h_addrtype;
 312                 sa.sin_port = htons(nport);
 313                 memcpy(&sa.sin_addr, *ap, he->h_length);
 314
 315                 if (connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 316                         saved_errno = errno;
 317                         fprintf(stderr, "%s[%d: %s]: errno=%s\n",
 318                                 host,
 319                                 cnt,
 320                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr),
 321                                 strerror(saved_errno));
 322                         close(sockfd);
 323                         sockfd = -1;
 324                         continue;
 325                 }
 326                 if (flags & CONNECT_VERBOSE)
 327                         fprintf(stderr, "%s ",
 328                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr));
 329                 break;
 330         }
 331
 332         if (sockfd < 0)
 333                 die("unable to connect a socket (%s)", strerror(saved_errno));
 334
 335         if (flags & CONNECT_VERBOSE)
 336                 fprintf(stderr, "done.\n");
 337
 338         return sockfd;
 339 }
 340
 341 #endif /* NO_IPV6 */
 342
 343
 344 static void git_tcp_connect(int fd[2], char *host, int flags)
 345 {
 346         int sockfd = git_tcp_connect_sock(host, flags);
 347
 348         fd[0] = sockfd;
 349         fd[1] = dup(sockfd);
 350 }
 351
 352
 353 static char *git_proxy_command;
 354 static const char *rhost_name;
 355 static int rhost_len;
 356
 357 static int git_proxy_command_options(const char *var, const char *value)
 358 {
 359         if (!strcmp(var, "core.gitproxy")) {
 360                 const char *for_pos;
 361                 int matchlen = -1;
 362                 int hostlen;
 363
 364                 if (git_proxy_command)
 365                         return 0;
 366                 /* [core]
 367                  * ;# matches www.kernel.org as well
 368                  * gitproxy = netcatter-1 for kernel.org
 369                  * gitproxy = netcatter-2 for sample.xz
 370                  * gitproxy = netcatter-default
 371                  */
 372                 for_pos = strstr(value, " for ");
 373                 if (!for_pos)
 374                         /* matches everybody */
 375                         matchlen = strlen(value);
 376                 else {
 377                         hostlen = strlen(for_pos + 5);
 378                         if (rhost_len < hostlen)
 379                                 matchlen = -1;
 380                         else if (!strncmp(for_pos + 5,
 381                                           rhost_name + rhost_len - hostlen,
 382                                           hostlen) &&
 383                                  ((rhost_len == hostlen) ||
 384                                   rhost_name[rhost_len - hostlen -1] == '.'))
 385                                 matchlen = for_pos - value;
 386                         else
 387                                 matchlen = -1;
 388                 }
 389                 if (0 <= matchlen) {
 390                         /* core.gitproxy = none for kernel.org */
 391                         if (matchlen == 4 &&
 392                             !memcmp(value, "none", 4))
 393                                 matchlen = 0;
 394                         git_proxy_command = xmalloc(matchlen + 1);
 395                         memcpy(git_proxy_command, value, matchlen);
 396                         git_proxy_command[matchlen] = 0;
 397                 }
 398                 return 0;
 399         }
 400
 401         return git_default_config(var, value);
 402 }
 403
 404 static int git_use_proxy(const char *host)
 405 {
 406         rhost_name = host;
 407         rhost_len = strlen(host);
 408         git_proxy_command = getenv("GIT_PROXY_COMMAND");
 409         git_config(git_proxy_command_options);
 410         rhost_name = NULL;
 411         return (git_proxy_command && *git_proxy_command);
 412 }
 413
 414 static void git_proxy_connect(int fd[2], char *host)
 415 {
 416         const char *port = STR(DEFAULT_GIT_PORT);
 417         char *colon, *end;
 418         const char *argv[4];
 419         struct child_process proxy;
 420
 421         if (host[0] == '[') {
 422                 end = strchr(host + 1, ']');
 423                 if (end) {
 424                         *end = 0;
 425                         end++;
 426                         host++;
 427                 } else
 428                         end = host;
 429         } else
 430                 end = host;
 431         colon = strchr(end, ':');
 432
 433         if (colon) {
 434                 *colon = 0;
 435                 port = colon + 1;
 436         }
 437
 438         argv[0] = git_proxy_command;
 439         argv[1] = host;
 440         argv[2] = port;
 441         argv[3] = NULL;
 442         memset(&proxy, 0, sizeof(proxy));
 443         proxy.argv = argv;
 444         proxy.in = -1;
 445         proxy.out = -1;
 446         if (start_command(&proxy))
 447                 die("cannot start proxy %s", argv[0]);
 448         fd[0] = proxy.out; /* read from proxy stdout */
 449         fd[1] = proxy.in;  /* write to proxy stdin */
 450 }
 451
 452 #define MAX_CMD_LEN 1024
 453
 454 /*
 455  * This returns 0 if the transport protocol does not need fork(2),
 456  * or a process id if it does.  Once done, finish the connection
 457  * with finish_connect() with the value returned from this function
 458  * (it is safe to call finish_connect() with 0 to support the former
 459  * case).
 460  *
 461  * Does not return a negative value on error; it just dies.
 462  */
 463 pid_t git_connect(int fd[2], char *url, const char *prog, int flags)
 464 {
 465         char *host, *path = url;
 466         char *end;
 467         int c;
 468         int pipefd[2][2];
 469         pid_t pid;
 470         enum protocol protocol = PROTO_LOCAL;
 471         int free_path = 0;
 472
 473         /* Without this we cannot rely on waitpid() to tell
 474          * what happened to our children.
 475          */
 476         signal(SIGCHLD, SIG_DFL);
 477
 478         host = strstr(url, "://");
 479         if(host) {
 480                 *host = '\0';
 481                 protocol = get_protocol(url);
 482                 host += 3;
 483                 c = '/';
 484         } else {
 485                 host = url;
 486                 c = ':';
 487         }
 488
 489         if (host[0] == '[') {
 490                 end = strchr(host + 1, ']');
 491                 if (end) {
 492                         *end = 0;
 493                         end++;
 494                         host++;
 495                 } else
 496                         end = host;
 497         } else
 498                 end = host;
 499
 500         path = strchr(end, c);
 501         if (c == ':') {
 502                 if (path) {
 503                         protocol = PROTO_SSH;
 504                         *path++ = '\0';
 505                 } else
 506                         path = host;
 507         }
 508
 509         if (!path || !*path)
 510                 die("No path specified. See 'man git-pull' for valid url syntax");
 511
 512         /*
 513          * null-terminate hostname and point path to ~ for URL's like this:
 514          *    ssh://host.xz/~user/repo
 515          */
 516         if (protocol != PROTO_LOCAL && host != url) {
 517                 char *ptr = path;
 518                 if (path[1] == '~')
 519                         path++;
 520                 else {
 521                         path = xstrdup(ptr);
 522                         free_path = 1;
 523                 }
 524
 525                 *ptr = '\0';
 526         }
 527
 528         if (protocol == PROTO_GIT) {
 529                 /* These underlying connection commands die() if they
 530                  * cannot connect.
 531                  */
 532                 char *target_host = xstrdup(host);
 533                 if (git_use_proxy(host))
 534                         git_proxy_connect(fd, host);
 535                 else
 536                         git_tcp_connect(fd, host, flags);
 537                 /*
 538                  * Separate original protocol components prog and path
 539                  * from extended components with a NUL byte.
 540                  */
 541                 packet_write(fd[1],
 542                              "%s %s%chost=%s%c",
 543                              prog, path, 0,
 544                              target_host, 0);
 545                 free(target_host);
 546                 if (free_path)
 547                         free(path);
 548                 return 0;
 549         }
 550
 551         if (pipe(pipefd[0]) < 0 || pipe(pipefd[1]) < 0)
 552                 die("unable to create pipe pair for communication");
 553         pid = fork();
 554         if (pid < 0)
 555                 die("unable to fork");
 556         if (!pid) {
 557                 char command[MAX_CMD_LEN];
 558                 char *posn = command;
 559                 int size = MAX_CMD_LEN;
 560                 int of = 0;
 561
 562                 of |= add_to_string(&posn, &size, prog, 0);
 563                 of |= add_to_string(&posn, &size, " ", 0);
 564                 of |= add_to_string(&posn, &size, path, 1);
 565
 566                 if (of)
 567                         die("command line too long");
 568
 569                 dup2(pipefd[1][0], 0);
 570                 dup2(pipefd[0][1], 1);
 571                 close(pipefd[0][0]);
 572                 close(pipefd[0][1]);
 573                 close(pipefd[1][0]);
 574                 close(pipefd[1][1]);
 575                 if (protocol == PROTO_SSH) {
 576                         const char *ssh, *ssh_basename;
 577                         ssh = getenv("GIT_SSH");
 578                         if (!ssh) ssh = "ssh";
 579                         ssh_basename = strrchr(ssh, '/');
 580                         if (!ssh_basename)
 581                                 ssh_basename = ssh;
 582                         else
 583                                 ssh_basename++;
 584                         execlp(ssh, ssh_basename, host, command, NULL);
 585                 }
 586                 else {
 587                         unsetenv(ALTERNATE_DB_ENVIRONMENT);
 588                         unsetenv(DB_ENVIRONMENT);
 589                         unsetenv(GIT_DIR_ENVIRONMENT);
 590                         unsetenv(GRAFT_ENVIRONMENT);
 591                         unsetenv(INDEX_ENVIRONMENT);
 592                         execlp("sh", "sh", "-c", command, NULL);
 593                 }
 594                 die("exec failed");
 595         }
 596         fd[0] = pipefd[0][0];
 597         fd[1] = pipefd[1][1];
 598         close(pipefd[0][1]);
 599         close(pipefd[1][0]);
 600         if (free_path)
 601                 free(path);
 602         return pid;
 603 }
 604
 605 int finish_connect(pid_t pid)
 606 {
 607         if (pid == 0)
 608                 return 0;
 609
 610         while (waitpid(pid, NULL, 0) < 0) {
 611                 if (errno != EINTR)
 612                         return -1;
 613         }
 614         return 0;
 615 }