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 /*
 157  * Returns a connected socket() fd, or else die()s.
 158  */
 159 static int git_tcp_connect_sock(char *host, int flags)
 160 {
 161         int sockfd = -1, saved_errno = 0;
 162         char *colon, *end;
 163         const char *port = STR(DEFAULT_GIT_PORT);
 164         struct addrinfo hints, *ai0, *ai;
 165         int gai;
 166
 167         if (host[0] == '[') {
 168                 end = strchr(host + 1, ']');
 169                 if (end) {
 170                         *end = 0;
 171                         end++;
 172                         host++;
 173                 } else
 174                         end = host;
 175         } else
 176                 end = host;
 177         colon = strchr(end, ':');
 178
 179         if (colon) {
 180                 *colon = 0;
 181                 port = colon + 1;
 182                 if (!*port)
 183                         port = "<none>";
 184         }
 185
 186         memset(&hints, 0, sizeof(hints));
 187         hints.ai_socktype = SOCK_STREAM;
 188         hints.ai_protocol = IPPROTO_TCP;
 189
 190         if (flags & CONNECT_VERBOSE)
 191                 fprintf(stderr, "Looking up %s ... ", host);
 192
 193         gai = getaddrinfo(host, port, &hints, &ai);
 194         if (gai)
 195                 die("Unable to look up %s (port %s) (%s)", host, port, gai_strerror(gai));
 196
 197         if (flags & CONNECT_VERBOSE)
 198                 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 199
 200         for (ai0 = ai; ai; ai = ai->ai_next) {
 201                 sockfd = socket(ai->ai_family,
 202                                 ai->ai_socktype, ai->ai_protocol);
 203                 if (sockfd < 0) {
 204                         saved_errno = errno;
 205                         continue;
 206                 }
 207                 if (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
 208                         saved_errno = errno;
 209                         close(sockfd);
 210                         sockfd = -1;
 211                         continue;
 212                 }
 213                 break;
 214         }
 215
 216         freeaddrinfo(ai0);
 217
 218         if (sockfd < 0)
 219                 die("unable to connect a socket (%s)", strerror(saved_errno));
 220
 221         if (flags & CONNECT_VERBOSE)
 222                 fprintf(stderr, "done.\n");
 223
 224         return sockfd;
 225 }
 226
 227 #else /* NO_IPV6 */
 228
 229 /*
 230  * Returns a connected socket() fd, or else die()s.
 231  */
 232 static int git_tcp_connect_sock(char *host, int flags)
 233 {
 234         int sockfd = -1, saved_errno = 0;
 235         char *colon, *end;
 236         char *port = STR(DEFAULT_GIT_PORT), *ep;
 237         struct hostent *he;
 238         struct sockaddr_in sa;
 239         char **ap;
 240         unsigned int nport;
 241
 242         if (host[0] == '[') {
 243                 end = strchr(host + 1, ']');
 244                 if (end) {
 245                         *end = 0;
 246                         end++;
 247                         host++;
 248                 } else
 249                         end = host;
 250         } else
 251                 end = host;
 252         colon = strchr(end, ':');
 253
 254         if (colon) {
 255                 *colon = 0;
 256                 port = colon + 1;
 257         }
 258
 259         if (flags & CONNECT_VERBOSE)
 260                 fprintf(stderr, "Looking up %s ... ", host);
 261
 262         he = gethostbyname(host);
 263         if (!he)
 264                 die("Unable to look up %s (%s)", host, hstrerror(h_errno));
 265         nport = strtoul(port, &ep, 10);
 266         if ( ep == port || *ep ) {
 267                 /* Not numeric */
 268                 struct servent *se = getservbyname(port,"tcp");
 269                 if ( !se )
 270                         die("Unknown port %s\n", port);
 271                 nport = se->s_port;
 272         }
 273
 274         if (flags & CONNECT_VERBOSE)
 275                 fprintf(stderr, "done.\nConnecting to %s (port %s) ... ", host, port);
 276
 277         for (ap = he->h_addr_list; *ap; ap++) {
 278                 sockfd = socket(he->h_addrtype, SOCK_STREAM, 0);
 279                 if (sockfd < 0) {
 280                         saved_errno = errno;
 281                         continue;
 282                 }
 283
 284                 memset(&sa, 0, sizeof sa);
 285                 sa.sin_family = he->h_addrtype;
 286                 sa.sin_port = htons(nport);
 287                 memcpy(&sa.sin_addr, *ap, he->h_length);
 288
 289                 if (connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) {
 290                         saved_errno = errno;
 291                         close(sockfd);
 292                         sockfd = -1;
 293                         continue;
 294                 }
 295                 break;
 296         }
 297
 298         if (sockfd < 0)
 299                 die("unable to connect a socket (%s)", strerror(saved_errno));
 300
 301         if (flags & CONNECT_VERBOSE)
 302                 fprintf(stderr, "done.\n");
 303
 304         return sockfd;
 305 }
 306
 307 #endif /* NO_IPV6 */
 308
 309
 310 static void git_tcp_connect(int fd[2], char *host, int flags)
 311 {
 312         int sockfd = git_tcp_connect_sock(host, flags);
 313
 314         fd[0] = sockfd;
 315         fd[1] = dup(sockfd);
 316 }
 317
 318
 319 static char *git_proxy_command;
 320 static const char *rhost_name;
 321 static int rhost_len;
 322
 323 static int git_proxy_command_options(const char *var, const char *value)
 324 {
 325         if (!strcmp(var, "core.gitproxy")) {
 326                 const char *for_pos;
 327                 int matchlen = -1;
 328                 int hostlen;
 329
 330                 if (git_proxy_command)
 331                         return 0;
 332                 /* [core]
 333                  * ;# matches www.kernel.org as well
 334                  * gitproxy = netcatter-1 for kernel.org
 335                  * gitproxy = netcatter-2 for sample.xz
 336                  * gitproxy = netcatter-default
 337                  */
 338                 for_pos = strstr(value, " for ");
 339                 if (!for_pos)
 340                         /* matches everybody */
 341                         matchlen = strlen(value);
 342                 else {
 343                         hostlen = strlen(for_pos + 5);
 344                         if (rhost_len < hostlen)
 345                                 matchlen = -1;
 346                         else if (!strncmp(for_pos + 5,
 347                                           rhost_name + rhost_len - hostlen,
 348                                           hostlen) &&
 349                                  ((rhost_len == hostlen) ||
 350                                   rhost_name[rhost_len - hostlen -1] == '.'))
 351                                 matchlen = for_pos - value;
 352                         else
 353                                 matchlen = -1;
 354                 }
 355                 if (0 <= matchlen) {
 356                         /* core.gitproxy = none for kernel.org */
 357                         if (matchlen == 4 &&
 358                             !memcmp(value, "none", 4))
 359                                 matchlen = 0;
 360                         git_proxy_command = xmalloc(matchlen + 1);
 361                         memcpy(git_proxy_command, value, matchlen);
 362                         git_proxy_command[matchlen] = 0;
 363                 }
 364                 return 0;
 365         }
 366
 367         return git_default_config(var, value);
 368 }
 369
 370 static int git_use_proxy(const char *host)
 371 {
 372         rhost_name = host;
 373         rhost_len = strlen(host);
 374         git_proxy_command = getenv("GIT_PROXY_COMMAND");
 375         git_config(git_proxy_command_options);
 376         rhost_name = NULL;
 377         return (git_proxy_command && *git_proxy_command);
 378 }
 379
 380 static void git_proxy_connect(int fd[2], char *host)
 381 {
 382         const char *port = STR(DEFAULT_GIT_PORT);
 383         char *colon, *end;
 384         const char *argv[4];
 385         struct child_process proxy;
 386
 387         if (host[0] == '[') {
 388                 end = strchr(host + 1, ']');
 389                 if (end) {
 390                         *end = 0;
 391                         end++;
 392                         host++;
 393                 } else
 394                         end = host;
 395         } else
 396                 end = host;
 397         colon = strchr(end, ':');
 398
 399         if (colon) {
 400                 *colon = 0;
 401                 port = colon + 1;
 402         }
 403
 404         argv[0] = git_proxy_command;
 405         argv[1] = host;
 406         argv[2] = port;
 407         argv[3] = NULL;
 408         memset(&proxy, 0, sizeof(proxy));
 409         proxy.argv = argv;
 410         proxy.in = -1;
 411         proxy.out = -1;
 412         if (start_command(&proxy))
 413                 die("cannot start proxy %s", argv[0]);
 414         fd[0] = proxy.out; /* read from proxy stdout */
 415         fd[1] = proxy.in;  /* write to proxy stdin */
 416 }
 417
 418 #define MAX_CMD_LEN 1024
 419
 420 /*
 421  * This returns 0 if the transport protocol does not need fork(2),
 422  * or a process id if it does.  Once done, finish the connection
 423  * with finish_connect() with the value returned from this function
 424  * (it is safe to call finish_connect() with 0 to support the former
 425  * case).
 426  *
 427  * Does not return a negative value on error; it just dies.
 428  */
 429 pid_t git_connect(int fd[2], char *url, const char *prog, int flags)
 430 {
 431         char *host, *path = url;
 432         char *end;
 433         int c;
 434         int pipefd[2][2];
 435         pid_t pid;
 436         enum protocol protocol = PROTO_LOCAL;
 437         int free_path = 0;
 438
 439         /* Without this we cannot rely on waitpid() to tell
 440          * what happened to our children.
 441          */
 442         signal(SIGCHLD, SIG_DFL);
 443
 444         host = strstr(url, "://");
 445         if(host) {
 446                 *host = '\0';
 447                 protocol = get_protocol(url);
 448                 host += 3;
 449                 c = '/';
 450         } else {
 451                 host = url;
 452                 c = ':';
 453         }
 454
 455         if (host[0] == '[') {
 456                 end = strchr(host + 1, ']');
 457                 if (end) {
 458                         *end = 0;
 459                         end++;
 460                         host++;
 461                 } else
 462                         end = host;
 463         } else
 464                 end = host;
 465
 466         path = strchr(end, c);
 467         if (c == ':') {
 468                 if (path) {
 469                         protocol = PROTO_SSH;
 470                         *path++ = '\0';
 471                 } else
 472                         path = host;
 473         }
 474
 475         if (!path || !*path)
 476                 die("No path specified. See 'man git-pull' for valid url syntax");
 477
 478         /*
 479          * null-terminate hostname and point path to ~ for URL's like this:
 480          *    ssh://host.xz/~user/repo
 481          */
 482         if (protocol != PROTO_LOCAL && host != url) {
 483                 char *ptr = path;
 484                 if (path[1] == '~')
 485                         path++;
 486                 else {
 487                         path = xstrdup(ptr);
 488                         free_path = 1;
 489                 }
 490
 491                 *ptr = '\0';
 492         }
 493
 494         if (protocol == PROTO_GIT) {
 495                 /* These underlying connection commands die() if they
 496                  * cannot connect.
 497                  */
 498                 char *target_host = xstrdup(host);
 499                 if (git_use_proxy(host))
 500                         git_proxy_connect(fd, host);
 501                 else
 502                         git_tcp_connect(fd, host, flags);
 503                 /*
 504                  * Separate original protocol components prog and path
 505                  * from extended components with a NUL byte.
 506                  */
 507                 packet_write(fd[1],
 508                              "%s %s%chost=%s%c",
 509                              prog, path, 0,
 510                              target_host, 0);
 511                 free(target_host);
 512                 if (free_path)
 513                         free(path);
 514                 return 0;
 515         }
 516
 517         if (pipe(pipefd[0]) < 0 || pipe(pipefd[1]) < 0)
 518                 die("unable to create pipe pair for communication");
 519         pid = fork();
 520         if (pid < 0)
 521                 die("unable to fork");
 522         if (!pid) {
 523                 char command[MAX_CMD_LEN];
 524                 char *posn = command;
 525                 int size = MAX_CMD_LEN;
 526                 int of = 0;
 527
 528                 of |= add_to_string(&posn, &size, prog, 0);
 529                 of |= add_to_string(&posn, &size, " ", 0);
 530                 of |= add_to_string(&posn, &size, path, 1);
 531
 532                 if (of)
 533                         die("command line too long");
 534
 535                 dup2(pipefd[1][0], 0);
 536                 dup2(pipefd[0][1], 1);
 537                 close(pipefd[0][0]);
 538                 close(pipefd[0][1]);
 539                 close(pipefd[1][0]);
 540                 close(pipefd[1][1]);
 541                 if (protocol == PROTO_SSH) {
 542                         const char *ssh, *ssh_basename;
 543                         ssh = getenv("GIT_SSH");
 544                         if (!ssh) ssh = "ssh";
 545                         ssh_basename = strrchr(ssh, '/');
 546                         if (!ssh_basename)
 547                                 ssh_basename = ssh;
 548                         else
 549                                 ssh_basename++;
 550                         execlp(ssh, ssh_basename, host, command, NULL);
 551                 }
 552                 else {
 553                         unsetenv(ALTERNATE_DB_ENVIRONMENT);
 554                         unsetenv(DB_ENVIRONMENT);
 555                         unsetenv(GIT_DIR_ENVIRONMENT);
 556                         unsetenv(GRAFT_ENVIRONMENT);
 557                         unsetenv(INDEX_ENVIRONMENT);
 558                         execlp("sh", "sh", "-c", command, NULL);
 559                 }
 560                 die("exec failed");
 561         }
 562         fd[0] = pipefd[0][0];
 563         fd[1] = pipefd[1][1];
 564         close(pipefd[0][1]);
 565         close(pipefd[1][0]);
 566         if (free_path)
 567                 free(path);
 568         return pid;
 569 }
 570
 571 int finish_connect(pid_t pid)
 572 {
 573         if (pid == 0)
 574                 return 0;
 575
 576         while (waitpid(pid, NULL, 0) < 0) {
 577                 if (errno != EINTR)
 578                         return -1;
 579         }
 580         return 0;
 581 }