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         if (!strcmp(name, "file"))
 150                 return PROTO_LOCAL;
 151         die("I don't handle protocol '%s'", name);
 152 }
 153
 154 #define STR_(s) # s
 155 #define STR(s)  STR_(s)
 156
 157 #ifndef NO_IPV6
 158
 159 static const char *ai_name(const struct addrinfo *ai)
 160 {
 161         static char addr[INET_ADDRSTRLEN];
 162         if ( AF_INET == ai->ai_family ) {
 163                 struct sockaddr_in *in;
 164                 in = (struct sockaddr_in *)ai->ai_addr;
 165                 inet_ntop(ai->ai_family, &in->sin_addr, addr, sizeof(addr));
 166         } else if ( AF_INET6 == ai->ai_family ) {
 167                 struct sockaddr_in6 *in;
 168                 in = (struct sockaddr_in6 *)ai->ai_addr;
 169                 inet_ntop(ai->ai_family, &in->sin6_addr, addr, sizeof(addr));
 170         } else {
 171                 strcpy(addr, "(unknown)");
 172         }
 173         return addr;
 174 }
 175
 176 /*
 177  * Returns a connected socket() fd, or else die()s.
 178  */
 179 static int git_tcp_connect_sock(char *host, int flags)
 180 {
 181         int sockfd = -1, saved_errno = 0;
 182         char *colon, *end;
 183         const char *port = STR(DEFAULT_GIT_PORT);
 184         struct addrinfo hints, *ai0, *ai;
 185         int gai;
 186         int cnt = 0;
 187
 188         if (host[0] == '[') {
 189                 end = strchr(host + 1, ']');
 190                 if (end) {
 191                         *end = 0;
 192                         end++;
 193                         host++;
 194                 } else
 195                         end = host;
 196         } else
 197                 end = host;
 198         colon = strchr(end, ':');
 199
 200         if (colon) {
 201                 *colon = 0;
 202                 port = colon + 1;
 203                 if (!*port)
 204                         port = "<none>";
 205         }
 206
 207         memset(&hints, 0, sizeof(hints));
 208         hints.ai_socktype = SOCK_STREAM;
 209         hints.ai_protocol = IPPROTO_TCP;
 210
 211         if (flags & CONNECT_VERBOSE)
 212                 fprintf(stderr, "Looking up %s ... ", host);
 213
 214         gai = getaddrinfo(host, port, &hints, &ai);
 215         if (gai)
 216                 die("Unable to look up %s (port %s) (%s)", host, port, gai_strerror(gai));
 217
 218         if (flags & CONNECT_VERBOSE)
 219                 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 220
 221         for (ai0 = ai; ai; ai = ai->ai_next) {
 222                 sockfd = socket(ai->ai_family,
 223                                 ai->ai_socktype, ai->ai_protocol);
 224                 if (sockfd < 0) {
 225                         saved_errno = errno;
 226                         continue;
 227                 }
 228                 if (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
 229                         saved_errno = errno;
 230                         fprintf(stderr, "%s[%d: %s]: errno=%s\n",
 231                                 host,
 232                                 cnt,
 233                                 ai_name(ai),
 234                                 strerror(saved_errno));
 235                         close(sockfd);
 236                         sockfd = -1;
 237                         continue;
 238                 }
 239                 if (flags & CONNECT_VERBOSE)
 240                         fprintf(stderr, "%s ", ai_name(ai));
 241                 break;
 242         }
 243
 244         freeaddrinfo(ai0);
 245
 246         if (sockfd < 0)
 247                 die("unable to connect a socket (%s)", strerror(saved_errno));
 248
 249         if (flags & CONNECT_VERBOSE)
 250                 fprintf(stderr, "done.\n");
 251
 252         return sockfd;
 253 }
 254
 255 #else /* NO_IPV6 */
 256
 257 /*
 258  * Returns a connected socket() fd, or else die()s.
 259  */
 260 static int git_tcp_connect_sock(char *host, int flags)
 261 {
 262         int sockfd = -1, saved_errno = 0;
 263         char *colon, *end;
 264         char *port = STR(DEFAULT_GIT_PORT), *ep;
 265         struct hostent *he;
 266         struct sockaddr_in sa;
 267         char **ap;
 268         unsigned int nport;
 269         int cnt;
 270
 271         if (host[0] == '[') {
 272                 end = strchr(host + 1, ']');
 273                 if (end) {
 274                         *end = 0;
 275                         end++;
 276                         host++;
 277                 } else
 278                         end = host;
 279         } else
 280                 end = host;
 281         colon = strchr(end, ':');
 282
 283         if (colon) {
 284                 *colon = 0;
 285                 port = colon + 1;
 286         }
 287
 288         if (flags & CONNECT_VERBOSE)
 289                 fprintf(stderr, "Looking up %s ... ", host);
 290
 291         he = gethostbyname(host);
 292         if (!he)
 293                 die("Unable to look up %s (%s)", host, hstrerror(h_errno));
 294         nport = strtoul(port, &ep, 10);
 295         if ( ep == port || *ep ) {
 296                 /* Not numeric */
 297                 struct servent *se = getservbyname(port,"tcp");
 298                 if ( !se )
 299                         die("Unknown port %s\n", port);
 300                 nport = se->s_port;
 301         }
 302
 303         if (flags & CONNECT_VERBOSE)
 304                 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 305
 306         for (cnt = 0, ap = he->h_addr_list; *ap; ap++, cnt++) {
 307                 sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 308                 if (sockfd < 0) {
 309                         saved_errno = errno;
 310                         continue;
 311                 }
 312
 313                 memset(&sa, 0, sizeof sa);
 314                 sa.sin_family = he->h_addrtype;
 315                 sa.sin_port = htons(nport);
 316                 memcpy(&sa.sin_addr, *ap, he->h_length);
 317
 318                 if (connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 319                         saved_errno = errno;
 320                         fprintf(stderr, "%s[%d: %s]: errno=%s\n",
 321                                 host,
 322                                 cnt,
 323                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr),
 324                                 strerror(saved_errno));
 325                         close(sockfd);
 326                         sockfd = -1;
 327                         continue;
 328                 }
 329                 if (flags & CONNECT_VERBOSE)
 330                         fprintf(stderr, "%s ",
 331                                 inet_ntoa(*(struct in_addr *)&sa.sin_addr));
 332                 break;
 333         }
 334
 335         if (sockfd < 0)
 336                 die("unable to connect a socket (%s)", strerror(saved_errno));
 337
 338         if (flags & CONNECT_VERBOSE)
 339                 fprintf(stderr, "done.\n");
 340
 341         return sockfd;
 342 }
 343
 344 #endif /* NO_IPV6 */
 345
 346
 347 static void git_tcp_connect(int fd[2], char *host, int flags)
 348 {
 349 #ifndef __MINGW32__
 350         int sockfd = git_tcp_connect_sock(host, flags);
 351 #else
 352         int sockfd;
 353         WSADATA wsa;
 354
 355         if (WSAStartup(MAKEWORD(2,2), &wsa))
 356                 die("unable to initialize winsock subsystem, error %d",
 357                         WSAGetLastError());
 358         atexit((void(*)(void)) WSACleanup);
 359
 360         sockfd = git_tcp_connect_sock(host, flags);
 361         /* convert into a file descriptor */
 362         if ((sockfd = _open_osfhandle(sockfd, O_RDWR|O_BINARY)) < 0)
 363                 die("unable to make a socket file descriptor: %s",
 364                         strerror(errno));
 365 #endif
 366
 367         fd[0] = sockfd;
 368         fd[1] = dup(sockfd);
 369 }
 370
 371
 372 static char *git_proxy_command;
 373 static const char *rhost_name;
 374 static int rhost_len;
 375
 376 static int git_proxy_command_options(const char *var, const char *value)
 377 {
 378         if (!strcmp(var, "core.gitproxy")) {
 379                 const char *for_pos;
 380                 int matchlen = -1;
 381                 int hostlen;
 382
 383                 if (git_proxy_command)
 384                         return 0;
 385                 /* [core]
 386                  * ;# matches www.kernel.org as well
 387                  * gitproxy = netcatter-1 for kernel.org
 388                  * gitproxy = netcatter-2 for sample.xz
 389                  * gitproxy = netcatter-default
 390                  */
 391                 for_pos = strstr(value, " for ");
 392                 if (!for_pos)
 393                         /* matches everybody */
 394                         matchlen = strlen(value);
 395                 else {
 396                         hostlen = strlen(for_pos + 5);
 397                         if (rhost_len < hostlen)
 398                                 matchlen = -1;
 399                         else if (!strncmp(for_pos + 5,
 400                                           rhost_name + rhost_len - hostlen,
 401                                           hostlen) &&
 402                                  ((rhost_len == hostlen) ||
 403                                   rhost_name[rhost_len - hostlen -1] == '.'))
 404                                 matchlen = for_pos - value;
 405                         else
 406                                 matchlen = -1;
 407                 }
 408                 if (0 <= matchlen) {
 409                         /* core.gitproxy = none for kernel.org */
 410                         if (matchlen == 4 &&
 411                             !memcmp(value, "none", 4))
 412                                 matchlen = 0;
 413                         git_proxy_command = xmalloc(matchlen + 1);
 414                         memcpy(git_proxy_command, value, matchlen);
 415                         git_proxy_command[matchlen] = 0;
 416                 }
 417                 return 0;
 418         }
 419
 420         return git_default_config(var, value);
 421 }
 422
 423 static int git_use_proxy(const char *host)
 424 {
 425         rhost_name = host;
 426         rhost_len = strlen(host);
 427         git_proxy_command = getenv("GIT_PROXY_COMMAND");
 428         git_config(git_proxy_command_options);
 429         rhost_name = NULL;
 430         return (git_proxy_command && *git_proxy_command);
 431 }
 432
 433 static void git_proxy_connect(int fd[2], char *host)
 434 {
 435         const char *port = STR(DEFAULT_GIT_PORT);
 436         char *colon, *end;
 437         const char *argv[4];
 438         struct child_process proxy;
 439
 440         if (host[0] == '[') {
 441                 end = strchr(host + 1, ']');
 442                 if (end) {
 443                         *end = 0;
 444                         end++;
 445                         host++;
 446                 } else
 447                         end = host;
 448         } else
 449                 end = host;
 450         colon = strchr(end, ':');
 451
 452         if (colon) {
 453                 *colon = 0;
 454                 port = colon + 1;
 455         }
 456
 457         argv[0] = git_proxy_command;
 458         argv[1] = host;
 459         argv[2] = port;
 460         argv[3] = NULL;
 461         memset(&proxy, 0, sizeof(proxy));
 462         proxy.argv = argv;
 463         proxy.in = -1;
 464         proxy.out = -1;
 465         if (start_command(&proxy))
 466                 die("cannot start proxy %s", argv[0]);
 467         fd[0] = proxy.out; /* read from proxy stdout */
 468         fd[1] = proxy.in;  /* write to proxy stdin */
 469 }
 470
 471 #define MAX_CMD_LEN 1024
 472
 473 /*
 474  * This returns 0 if the transport protocol does not need fork(2),
 475  * or a process id if it does.  Once done, finish the connection
 476  * with finish_connect() with the value returned from this function
 477  * (it is safe to call finish_connect() with 0 to support the former
 478  * case).
 479  *
 480  * Does not return a negative value on error; it just dies.
 481  */
 482 pid_t git_connect(int fd[2], char *url, const char *prog, int flags)
 483 {
 484         char *host, *path = url;
 485         char *end;
 486         int c;
 487         int pipefd[2][2];
 488         pid_t pid;
 489         enum protocol protocol = PROTO_LOCAL;
 490         int free_path = 0;
 491
 492         /* Without this we cannot rely on waitpid() to tell
 493          * what happened to our children.
 494          */
 495         signal(SIGCHLD, SIG_DFL);
 496
 497         host = strstr(url, "://");
 498         if(host) {
 499                 *host = '\0';
 500                 protocol = get_protocol(url);
 501                 host += 3;
 502                 c = '/';
 503         } else {
 504                 host = url;
 505                 c = ':';
 506         }
 507
 508         if (host[0] == '[') {
 509                 end = strchr(host + 1, ']');
 510                 if (end) {
 511                         *end = 0;
 512                         end++;
 513                         host++;
 514                 } else
 515                         end = host;
 516         } else
 517                 end = host;
 518
 519         path = strchr(end, c);
 520         if (path) {
 521                 if (c == ':'
 522 #ifdef __MINGW32__
 523                     && path - end > 1     /* host must have at least 2 chars to catch DOS C:/path */
 524 #endif
 525                     ) {
 526                         protocol = PROTO_SSH;
 527                         *path++ = '\0';
 528                 }
 529         } else
 530                 path = end;
 531
 532         if (!path || !*path)
 533                 die("No path specified. See 'man git-pull' for valid url syntax");
 534
 535         /*
 536          * null-terminate hostname and point path to ~ for URL's like this:
 537          *    ssh://host.xz/~user/repo
 538          */
 539         if (protocol != PROTO_LOCAL && host != url) {
 540                 char *ptr = path;
 541                 if (path[1] == '~')
 542                         path++;
 543                 else {
 544                         path = xstrdup(ptr);
 545                         free_path = 1;
 546                 }
 547
 548                 *ptr = '\0';
 549         }
 550
 551         if (protocol == PROTO_GIT) {
 552                 /* These underlying connection commands die() if they
 553                  * cannot connect.
 554                  */
 555                 char *target_host = xstrdup(host);
 556                 if (git_use_proxy(host))
 557                         git_proxy_connect(fd, host);
 558                 else
 559                         git_tcp_connect(fd, host, flags);
 560                 /*
 561                  * Separate original protocol components prog and path
 562                  * from extended components with a NUL byte.
 563                  */
 564                 packet_write(fd[1],
 565                              "%s %s%chost=%s%c",
 566                              prog, path, 0,
 567                              target_host, 0);
 568                 free(target_host);
 569                 if (free_path)
 570                         free(path);
 571                 return 0;
 572         }
 573
 574         if (pipe(pipefd[0]) < 0 || pipe(pipefd[1]) < 0)
 575                 die("unable to create pipe pair for communication");
 576
 577         char command[MAX_CMD_LEN];
 578         char *posn = command;
 579         int size = MAX_CMD_LEN;
 580         int of = 0;
 581
 582         of |= add_to_string(&posn, &size, prog, 0);
 583         of |= add_to_string(&posn, &size, " ", 0);
 584         of |= add_to_string(&posn, &size, path, 1);
 585
 586         if (of)
 587                 die("command line too long");
 588
 589         if (protocol == PROTO_SSH) {
 590                 const char *argv[] = { NULL, host, command, NULL };
 591                 const char *ssh = getenv("GIT_SSH");
 592                 if (!ssh) ssh = "ssh";
 593                 pid = spawnvpe_pipe(ssh, argv, (const char**) environ, pipefd[1], pipefd[0]);
 594         }
 595         else {
 596                 const char *argv[] = { NULL, "-c", command, NULL };
 597                 const char **env = copy_environ();
 598                 env_unsetenv(env, ALTERNATE_DB_ENVIRONMENT);
 599                 env_unsetenv(env, DB_ENVIRONMENT);
 600                 env_unsetenv(env, GIT_DIR_ENVIRONMENT);
 601                 env_unsetenv(env, GIT_WORK_TREE_ENVIRONMENT);
 602                 env_unsetenv(env, GRAFT_ENVIRONMENT);
 603                 env_unsetenv(env, INDEX_ENVIRONMENT);
 604                 pid = spawnvpe_pipe("sh", argv, env, pipefd[1], pipefd[0]);
 605         }
 606         if (pid < 0)
 607                 die("unable to fork");
 608         fd[0] = pipefd[0][0];
 609         fd[1] = pipefd[1][1];
 610         if (free_path)
 611                 free(path);
 612         return pid;
 613 }
 614
 615 int finish_connect(pid_t pid)
 616 {
 617         if (pid == 0)
 618                 return 0;
 619
 620         while (waitpid(pid, NULL, 0) < 0) {
 621                 if (errno != EINTR)
 622                         return -1;
 623         }
 624         return 0;
 625 }