daemon.c

   1 #include "cache.h"
   2 #include "config.h"
   3 #include "pkt-line.h"
   4 #include "run-command.h"
   5 #include "strbuf.h"
   6 #include "string-list.h"
   7
   8 #ifdef NO_INITGROUPS
   9 #define initgroups(x, y) (0) /* nothing */
  10 #endif
  11
  12 static int log_syslog;
  13 static int verbose;
  14 static int reuseaddr;
  15 static int informative_errors;
  16
  17 static const char daemon_usage[] =
  18 "git daemon [--verbose] [--syslog] [--export-all]\n"
  19 "           [--timeout=<n>] [--init-timeout=<n>] [--max-connections=<n>]\n"
  20 "           [--strict-paths] [--base-path=<path>] [--base-path-relaxed]\n"
  21 "           [--user-path | --user-path=<path>]\n"
  22 "           [--interpolated-path=<path>]\n"
  23 "           [--reuseaddr] [--pid-file=<file>]\n"
  24 "           [--(enable|disable|allow-override|forbid-override)=<service>]\n"
  25 "           [--access-hook=<path>]\n"
  26 "           [--inetd | [--listen=<host_or_ipaddr>] [--port=<n>]\n"
  27 "                      [--detach] [--user=<user> [--group=<group>]]\n"
  28 "           [<directory>...]";
  29
  30 /* List of acceptable pathname prefixes */
  31 static const char **ok_paths;
  32 static int strict_paths;
  33
  34 /* If this is set, git-daemon-export-ok is not required */
  35 static int export_all_trees;
  36
  37 /* Take all paths relative to this one if non-NULL */
  38 static const char *base_path;
  39 static const char *interpolated_path;
  40 static int base_path_relaxed;
  41
  42 /* If defined, ~user notation is allowed and the string is inserted
  43  * after ~user/.  E.g. a request to git://host/~alice/frotz would
  44  * go to /home/alice/pub_git/frotz with --user-path=pub_git.
  45  */
  46 static const char *user_path;
  47
  48 /* Timeout, and initial timeout */
  49 static unsigned int timeout;
  50 static unsigned int init_timeout;
  51
  52 struct hostinfo {
  53         struct strbuf hostname;
  54         struct strbuf canon_hostname;
  55         struct strbuf ip_address;
  56         struct strbuf tcp_port;
  57         unsigned int hostname_lookup_done:1;
  58         unsigned int saw_extended_args:1;
  59 };
  60
  61 static void lookup_hostname(struct hostinfo *hi);
  62
  63 static const char *get_canon_hostname(struct hostinfo *hi)
  64 {
  65         lookup_hostname(hi);
  66         return hi->canon_hostname.buf;
  67 }
  68
  69 static const char *get_ip_address(struct hostinfo *hi)
  70 {
  71         lookup_hostname(hi);
  72         return hi->ip_address.buf;
  73 }
  74
  75 static void logreport(int priority, const char *err, va_list params)
  76 {
  77         if (log_syslog) {
  78                 char buf[1024];
  79                 vsnprintf(buf, sizeof(buf), err, params);
  80                 syslog(priority, "%s", buf);
  81         } else {
  82                 /*
  83                  * Since stderr is set to buffered mode, the
  84                  * logging of different processes will not overlap
  85                  * unless they overflow the (rather big) buffers.
  86                  */
  87                 fprintf(stderr, "[%"PRIuMAX"] ", (uintmax_t)getpid());
  88                 vfprintf(stderr, err, params);
  89                 fputc('\n', stderr);
  90                 fflush(stderr);
  91         }
  92 }
  93
  94 __attribute__((format (printf, 1, 2)))
  95 static void logerror(const char *err, ...)
  96 {
  97         va_list params;
  98         va_start(params, err);
  99         logreport(LOG_ERR, err, params);
 100         va_end(params);
 101 }
 102
 103 __attribute__((format (printf, 1, 2)))
 104 static void loginfo(const char *err, ...)
 105 {
 106         va_list params;
 107         if (!verbose)
 108                 return;
 109         va_start(params, err);
 110         logreport(LOG_INFO, err, params);
 111         va_end(params);
 112 }
 113
 114 static void NORETURN daemon_die(const char *err, va_list params)
 115 {
 116         logreport(LOG_ERR, err, params);
 117         exit(1);
 118 }
 119
 120 struct expand_path_context {
 121         const char *directory;
 122         struct hostinfo *hostinfo;
 123 };
 124
 125 static size_t expand_path(struct strbuf *sb, const char *placeholder, void *ctx)
 126 {
 127         struct expand_path_context *context = ctx;
 128         struct hostinfo *hi = context->hostinfo;
 129
 130         switch (placeholder[0]) {
 131         case 'H':
 132                 strbuf_addbuf(sb, &hi->hostname);
 133                 return 1;
 134         case 'C':
 135                 if (placeholder[1] == 'H') {
 136                         strbuf_addstr(sb, get_canon_hostname(hi));
 137                         return 2;
 138                 }
 139                 break;
 140         case 'I':
 141                 if (placeholder[1] == 'P') {
 142                         strbuf_addstr(sb, get_ip_address(hi));
 143                         return 2;
 144                 }
 145                 break;
 146         case 'P':
 147                 strbuf_addbuf(sb, &hi->tcp_port);
 148                 return 1;
 149         case 'D':
 150                 strbuf_addstr(sb, context->directory);
 151                 return 1;
 152         }
 153         return 0;
 154 }
 155
 156 static const char *path_ok(const char *directory, struct hostinfo *hi)
 157 {
 158         static char rpath[PATH_MAX];
 159         static char interp_path[PATH_MAX];
 160         size_t rlen;
 161         const char *path;
 162         const char *dir;
 163
 164         dir = directory;
 165
 166         if (daemon_avoid_alias(dir)) {
 167                 logerror("'%s': aliased", dir);
 168                 return NULL;
 169         }
 170
 171         if (*dir == '~') {
 172                 if (!user_path) {
 173                         logerror("'%s': User-path not allowed", dir);
 174                         return NULL;
 175                 }
 176                 if (*user_path) {
 177                         /* Got either "~alice" or "~alice/foo";
 178                          * rewrite them to "~alice/%s" or
 179                          * "~alice/%s/foo".
 180                          */
 181                         int namlen, restlen = strlen(dir);
 182                         const char *slash = strchr(dir, '/');
 183                         if (!slash)
 184                                 slash = dir + restlen;
 185                         namlen = slash - dir;
 186                         restlen -= namlen;
 187                         loginfo("userpath <%s>, request <%s>, namlen %d, restlen %d, slash <%s>", user_path, dir, namlen, restlen, slash);
 188                         rlen = snprintf(rpath, sizeof(rpath), "%.*s/%s%.*s",
 189                                         namlen, dir, user_path, restlen, slash);
 190                         if (rlen >= sizeof(rpath)) {
 191                                 logerror("user-path too large: %s", rpath);
 192                                 return NULL;
 193                         }
 194                         dir = rpath;
 195                 }
 196         }
 197         else if (interpolated_path && hi->saw_extended_args) {
 198                 struct strbuf expanded_path = STRBUF_INIT;
 199                 struct expand_path_context context;
 200
 201                 context.directory = directory;
 202                 context.hostinfo = hi;
 203
 204                 if (*dir != '/') {
 205                         /* Allow only absolute */
 206                         logerror("'%s': Non-absolute path denied (interpolated-path active)", dir);
 207                         return NULL;
 208                 }
 209
 210                 strbuf_expand(&expanded_path, interpolated_path,
 211                               expand_path, &context);
 212
 213                 rlen = strlcpy(interp_path, expanded_path.buf,
 214                                sizeof(interp_path));
 215                 if (rlen >= sizeof(interp_path)) {
 216                         logerror("interpolated path too large: %s",
 217                                  interp_path);
 218                         return NULL;
 219                 }
 220
 221                 strbuf_release(&expanded_path);
 222                 loginfo("Interpolated dir '%s'", interp_path);
 223
 224                 dir = interp_path;
 225         }
 226         else if (base_path) {
 227                 if (*dir != '/') {
 228                         /* Allow only absolute */
 229                         logerror("'%s': Non-absolute path denied (base-path active)", dir);
 230                         return NULL;
 231                 }
 232                 rlen = snprintf(rpath, sizeof(rpath), "%s%s", base_path, dir);
 233                 if (rlen >= sizeof(rpath)) {
 234                         logerror("base-path too large: %s", rpath);
 235                         return NULL;
 236                 }
 237                 dir = rpath;
 238         }
 239
 240         path = enter_repo(dir, strict_paths);
 241         if (!path && base_path && base_path_relaxed) {
 242                 /*
 243                  * if we fail and base_path_relaxed is enabled, try without
 244                  * prefixing the base path
 245                  */
 246                 dir = directory;
 247                 path = enter_repo(dir, strict_paths);
 248         }
 249
 250         if (!path) {
 251                 logerror("'%s' does not appear to be a git repository", dir);
 252                 return NULL;
 253         }
 254
 255         if ( ok_paths && *ok_paths ) {
 256                 const char **pp;
 257                 int pathlen = strlen(path);
 258
 259                 /* The validation is done on the paths after enter_repo
 260                  * appends optional {.git,.git/.git} and friends, but
 261                  * it does not use getcwd().  So if your /pub is
 262                  * a symlink to /mnt/pub, you can whitelist /pub and
 263                  * do not have to say /mnt/pub.
 264                  * Do not say /pub/.
 265                  */
 266                 for ( pp = ok_paths ; *pp ; pp++ ) {
 267                         int len = strlen(*pp);
 268                         if (len <= pathlen &&
 269                             !memcmp(*pp, path, len) &&
 270                             (path[len] == '\0' ||
 271                              (!strict_paths && path[len] == '/')))
 272                                 return path;
 273                 }
 274         }
 275         else {
 276                 /* be backwards compatible */
 277                 if (!strict_paths)
 278                         return path;
 279         }
 280
 281         logerror("'%s': not in whitelist", path);
 282         return NULL;            /* Fallthrough. Deny by default */
 283 }
 284
 285 typedef int (*daemon_service_fn)(const struct argv_array *env);
 286 struct daemon_service {
 287         const char *name;
 288         const char *config_name;
 289         daemon_service_fn fn;
 290         int enabled;
 291         int overridable;
 292 };
 293
 294 static int daemon_error(const char *dir, const char *msg)
 295 {
 296         if (!informative_errors)
 297                 msg = "access denied or repository not exported";
 298         packet_write_fmt(1, "ERR %s: %s", msg, dir);
 299         return -1;
 300 }
 301
 302 static const char *access_hook;
 303
 304 static int run_access_hook(struct daemon_service *service, const char *dir,
 305                            const char *path, struct hostinfo *hi)
 306 {
 307         struct child_process child = CHILD_PROCESS_INIT;
 308         struct strbuf buf = STRBUF_INIT;
 309         const char *argv[8];
 310         const char **arg = argv;
 311         char *eol;
 312         int seen_errors = 0;
 313
 314         *arg++ = access_hook;
 315         *arg++ = service->name;
 316         *arg++ = path;
 317         *arg++ = hi->hostname.buf;
 318         *arg++ = get_canon_hostname(hi);
 319         *arg++ = get_ip_address(hi);
 320         *arg++ = hi->tcp_port.buf;
 321         *arg = NULL;
 322
 323         child.use_shell = 1;
 324         child.argv = argv;
 325         child.no_stdin = 1;
 326         child.no_stderr = 1;
 327         child.out = -1;
 328         if (start_command(&child)) {
 329                 logerror("daemon access hook '%s' failed to start",
 330                          access_hook);
 331                 goto error_return;
 332         }
 333         if (strbuf_read(&buf, child.out, 0) < 0) {
 334                 logerror("failed to read from pipe to daemon access hook '%s'",
 335                          access_hook);
 336                 strbuf_reset(&buf);
 337                 seen_errors = 1;
 338         }
 339         if (close(child.out) < 0) {
 340                 logerror("failed to close pipe to daemon access hook '%s'",
 341                          access_hook);
 342                 seen_errors = 1;
 343         }
 344         if (finish_command(&child))
 345                 seen_errors = 1;
 346
 347         if (!seen_errors) {
 348                 strbuf_release(&buf);
 349                 return 0;
 350         }
 351
 352 error_return:
 353         strbuf_ltrim(&buf);
 354         if (!buf.len)
 355                 strbuf_addstr(&buf, "service rejected");
 356         eol = strchr(buf.buf, '\n');
 357         if (eol)
 358                 *eol = '\0';
 359         errno = EACCES;
 360         daemon_error(dir, buf.buf);
 361         strbuf_release(&buf);
 362         return -1;
 363 }
 364
 365 static int run_service(const char *dir, struct daemon_service *service,
 366                        struct hostinfo *hi, const struct argv_array *env)
 367 {
 368         const char *path;
 369         int enabled = service->enabled;
 370         struct strbuf var = STRBUF_INIT;
 371
 372         loginfo("Request %s for '%s'", service->name, dir);
 373
 374         if (!enabled && !service->overridable) {
 375                 logerror("'%s': service not enabled.", service->name);
 376                 errno = EACCES;
 377                 return daemon_error(dir, "service not enabled");
 378         }
 379
 380         if (!(path = path_ok(dir, hi)))
 381                 return daemon_error(dir, "no such repository");
 382
 383         /*
 384          * Security on the cheap.
 385          *
 386          * We want a readable HEAD, usable "objects" directory, and
 387          * a "git-daemon-export-ok" flag that says that the other side
 388          * is ok with us doing this.
 389          *
 390          * path_ok() uses enter_repo() and does whitelist checking.
 391          * We only need to make sure the repository is exported.
 392          */
 393
 394         if (!export_all_trees && access("git-daemon-export-ok", F_OK)) {
 395                 logerror("'%s': repository not exported.", path);
 396                 errno = EACCES;
 397                 return daemon_error(dir, "repository not exported");
 398         }
 399
 400         if (service->overridable) {
 401                 strbuf_addf(&var, "daemon.%s", service->config_name);
 402                 git_config_get_bool(var.buf, &enabled);
 403                 strbuf_release(&var);
 404         }
 405         if (!enabled) {
 406                 logerror("'%s': service not enabled for '%s'",
 407                          service->name, path);
 408                 errno = EACCES;
 409                 return daemon_error(dir, "service not enabled");
 410         }
 411
 412         /*
 413          * Optionally, a hook can choose to deny access to the
 414          * repository depending on the phase of the moon.
 415          */
 416         if (access_hook && run_access_hook(service, dir, path, hi))
 417                 return -1;
 418
 419         /*
 420          * We'll ignore SIGTERM from now on, we have a
 421          * good client.
 422          */
 423         signal(SIGTERM, SIG_IGN);
 424
 425         return service->fn(env);
 426 }
 427
 428 static void copy_to_log(int fd)
 429 {
 430         struct strbuf line = STRBUF_INIT;
 431         FILE *fp;
 432
 433         fp = fdopen(fd, "r");
 434         if (fp == NULL) {
 435                 logerror("fdopen of error channel failed");
 436                 close(fd);
 437                 return;
 438         }
 439
 440         while (strbuf_getline_lf(&line, fp) != EOF) {
 441                 logerror("%s", line.buf);
 442                 strbuf_setlen(&line, 0);
 443         }
 444
 445         strbuf_release(&line);
 446         fclose(fp);
 447 }
 448
 449 static int run_service_command(struct child_process *cld)
 450 {
 451         argv_array_push(&cld->args, ".");
 452         cld->git_cmd = 1;
 453         cld->err = -1;
 454         if (start_command(cld))
 455                 return -1;
 456
 457         close(0);
 458         close(1);
 459
 460         copy_to_log(cld->err);
 461
 462         return finish_command(cld);
 463 }
 464
 465 static int upload_pack(const struct argv_array *env)
 466 {
 467         struct child_process cld = CHILD_PROCESS_INIT;
 468         argv_array_pushl(&cld.args, "upload-pack", "--strict", NULL);
 469         argv_array_pushf(&cld.args, "--timeout=%u", timeout);
 470
 471         argv_array_pushv(&cld.env_array, env->argv);
 472
 473         return run_service_command(&cld);
 474 }
 475
 476 static int upload_archive(const struct argv_array *env)
 477 {
 478         struct child_process cld = CHILD_PROCESS_INIT;
 479         argv_array_push(&cld.args, "upload-archive");
 480
 481         argv_array_pushv(&cld.env_array, env->argv);
 482
 483         return run_service_command(&cld);
 484 }
 485
 486 static int receive_pack(const struct argv_array *env)
 487 {
 488         struct child_process cld = CHILD_PROCESS_INIT;
 489         argv_array_push(&cld.args, "receive-pack");
 490
 491         argv_array_pushv(&cld.env_array, env->argv);
 492
 493         return run_service_command(&cld);
 494 }
 495
 496 static struct daemon_service daemon_service[] = {
 497         { "upload-archive", "uploadarch", upload_archive, 0, 1 },
 498         { "upload-pack", "uploadpack", upload_pack, 1, 1 },
 499         { "receive-pack", "receivepack", receive_pack, 0, 1 },
 500 };
 501
 502 static void enable_service(const char *name, int ena)
 503 {
 504         int i;
 505         for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
 506                 if (!strcmp(daemon_service[i].name, name)) {
 507                         daemon_service[i].enabled = ena;
 508                         return;
 509                 }
 510         }
 511         die("No such service %s", name);
 512 }
 513
 514 static void make_service_overridable(const char *name, int ena)
 515 {
 516         int i;
 517         for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
 518                 if (!strcmp(daemon_service[i].name, name)) {
 519                         daemon_service[i].overridable = ena;
 520                         return;
 521                 }
 522         }
 523         die("No such service %s", name);
 524 }
 525
 526 static void parse_host_and_port(char *hostport, char **host,
 527         char **port)
 528 {
 529         if (*hostport == '[') {
 530                 char *end;
 531
 532                 end = strchr(hostport, ']');
 533                 if (!end)
 534                         die("Invalid request ('[' without ']')");
 535                 *end = '\0';
 536                 *host = hostport + 1;
 537                 if (!end[1])
 538                         *port = NULL;
 539                 else if (end[1] == ':')
 540                         *port = end + 2;
 541                 else
 542                         die("Garbage after end of host part");
 543         } else {
 544                 *host = hostport;
 545                 *port = strrchr(hostport, ':');
 546                 if (*port) {
 547                         **port = '\0';
 548                         ++*port;
 549                 }
 550         }
 551 }
 552
 553 /*
 554  * Sanitize a string from the client so that it's OK to be inserted into a
 555  * filesystem path. Specifically, we disallow slashes, runs of "..", and
 556  * trailing and leading dots, which means that the client cannot escape
 557  * our base path via ".." traversal.
 558  */
 559 static void sanitize_client(struct strbuf *out, const char *in)
 560 {
 561         for (; *in; in++) {
 562                 if (*in == '/')
 563                         continue;
 564                 if (*in == '.' && (!out->len || out->buf[out->len - 1] == '.'))
 565                         continue;
 566                 strbuf_addch(out, *in);
 567         }
 568
 569         while (out->len && out->buf[out->len - 1] == '.')
 570                 strbuf_setlen(out, out->len - 1);
 571 }
 572
 573 /*
 574  * Like sanitize_client, but we also perform any canonicalization
 575  * to make life easier on the admin.
 576  */
 577 static void canonicalize_client(struct strbuf *out, const char *in)
 578 {
 579         sanitize_client(out, in);
 580         strbuf_tolower(out);
 581 }
 582
 583 /*
 584  * Read the host as supplied by the client connection.
 585  *
 586  * Returns a pointer to the character after the NUL byte terminating the host
 587  * arguemnt, or 'extra_args' if there is no host arguemnt.
 588  */
 589 static char *parse_host_arg(struct hostinfo *hi, char *extra_args, int buflen)
 590 {
 591         char *val;
 592         int vallen;
 593         char *end = extra_args + buflen;
 594
 595         if (extra_args < end && *extra_args) {
 596                 hi->saw_extended_args = 1;
 597                 if (strncasecmp("host=", extra_args, 5) == 0) {
 598                         val = extra_args + 5;
 599                         vallen = strlen(val) + 1;
 600                         if (*val) {
 601                                 /* Split <host>:<port> at colon. */
 602                                 char *host;
 603                                 char *port;
 604                                 parse_host_and_port(val, &host, &port);
 605                                 if (port)
 606                                         sanitize_client(&hi->tcp_port, port);
 607                                 canonicalize_client(&hi->hostname, host);
 608                                 hi->hostname_lookup_done = 0;
 609                         }
 610
 611                         /* On to the next one */
 612                         extra_args = val + vallen;
 613                 }
 614                 if (extra_args < end && *extra_args)
 615                         die("Invalid request");
 616         }
 617
 618         return extra_args;
 619 }
 620
 621 static void parse_extra_args(struct hostinfo *hi, struct argv_array *env,
 622                              char *extra_args, int buflen)
 623 {
 624         const char *end = extra_args + buflen;
 625         struct strbuf git_protocol = STRBUF_INIT;
 626
 627         /* First look for the host argument */
 628         extra_args = parse_host_arg(hi, extra_args, buflen);
 629
 630         /* Look for additional arguments places after a second NUL byte */
 631         for (; extra_args < end; extra_args += strlen(extra_args) + 1) {
 632                 const char *arg = extra_args;
 633
 634                 /*
 635                  * Parse the extra arguments, adding most to 'git_protocol'
 636                  * which will be used to set the 'GIT_PROTOCOL' envvar in the
 637                  * service that will be run.
 638                  *
 639                  * If there ends up being a particular arg in the future that
 640                  * git-daemon needs to parse specificly (like the 'host' arg)
 641                  * then it can be parsed here and not added to 'git_protocol'.
 642                  */
 643                 if (*arg) {
 644                         if (git_protocol.len > 0)
 645                                 strbuf_addch(&git_protocol, ':');
 646                         strbuf_addstr(&git_protocol, arg);
 647                 }
 648         }
 649
 650         if (git_protocol.len > 0)
 651                 argv_array_pushf(env, GIT_PROTOCOL_ENVIRONMENT "=%s",
 652                                  git_protocol.buf);
 653         strbuf_release(&git_protocol);
 654 }
 655
 656 /*
 657  * Locate canonical hostname and its IP address.
 658  */
 659 static void lookup_hostname(struct hostinfo *hi)
 660 {
 661         if (!hi->hostname_lookup_done && hi->hostname.len) {
 662 #ifndef NO_IPV6
 663                 struct addrinfo hints;
 664                 struct addrinfo *ai;
 665                 int gai;
 666                 static char addrbuf[HOST_NAME_MAX + 1];
 667
 668                 memset(&hints, 0, sizeof(hints));
 669                 hints.ai_flags = AI_CANONNAME;
 670
 671                 gai = getaddrinfo(hi->hostname.buf, NULL, &hints, &ai);
 672                 if (!gai) {
 673                         struct sockaddr_in *sin_addr = (void *)ai->ai_addr;
 674
 675                         inet_ntop(AF_INET, &sin_addr->sin_addr,
 676                                   addrbuf, sizeof(addrbuf));
 677                         strbuf_addstr(&hi->ip_address, addrbuf);
 678
 679                         if (ai->ai_canonname)
 680                                 sanitize_client(&hi->canon_hostname,
 681                                                 ai->ai_canonname);
 682                         else
 683                                 strbuf_addbuf(&hi->canon_hostname,
 684                                               &hi->ip_address);
 685
 686                         freeaddrinfo(ai);
 687                 }
 688 #else
 689                 struct hostent *hent;
 690                 struct sockaddr_in sa;
 691                 char **ap;
 692                 static char addrbuf[HOST_NAME_MAX + 1];
 693
 694                 hent = gethostbyname(hi->hostname.buf);
 695                 if (hent) {
 696                         ap = hent->h_addr_list;
 697                         memset(&sa, 0, sizeof sa);
 698                         sa.sin_family = hent->h_addrtype;
 699                         sa.sin_port = htons(0);
 700                         memcpy(&sa.sin_addr, *ap, hent->h_length);
 701
 702                         inet_ntop(hent->h_addrtype, &sa.sin_addr,
 703                                   addrbuf, sizeof(addrbuf));
 704
 705                         sanitize_client(&hi->canon_hostname, hent->h_name);
 706                         strbuf_addstr(&hi->ip_address, addrbuf);
 707                 }
 708 #endif
 709                 hi->hostname_lookup_done = 1;
 710         }
 711 }
 712
 713 static void hostinfo_init(struct hostinfo *hi)
 714 {
 715         memset(hi, 0, sizeof(*hi));
 716         strbuf_init(&hi->hostname, 0);
 717         strbuf_init(&hi->canon_hostname, 0);
 718         strbuf_init(&hi->ip_address, 0);
 719         strbuf_init(&hi->tcp_port, 0);
 720 }
 721
 722 static void hostinfo_clear(struct hostinfo *hi)
 723 {
 724         strbuf_release(&hi->hostname);
 725         strbuf_release(&hi->canon_hostname);
 726         strbuf_release(&hi->ip_address);
 727         strbuf_release(&hi->tcp_port);
 728 }
 729
 730 static void set_keep_alive(int sockfd)
 731 {
 732         int ka = 1;
 733
 734         if (setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, &ka, sizeof(ka)) < 0) {
 735                 if (errno != ENOTSOCK)
 736                         logerror("unable to set SO_KEEPALIVE on socket: %s",
 737                                 strerror(errno));
 738         }
 739 }
 740
 741 static int execute(void)
 742 {
 743         char *line = packet_buffer;
 744         int pktlen, len, i;
 745         char *addr = getenv("REMOTE_ADDR"), *port = getenv("REMOTE_PORT");
 746         struct hostinfo hi;
 747         struct argv_array env = ARGV_ARRAY_INIT;
 748
 749         hostinfo_init(&hi);
 750
 751         if (addr)
 752                 loginfo("Connection from %s:%s", addr, port);
 753
 754         set_keep_alive(0);
 755         alarm(init_timeout ? init_timeout : timeout);
 756         pktlen = packet_read(0, NULL, NULL, packet_buffer, sizeof(packet_buffer), 0);
 757         alarm(0);
 758
 759         len = strlen(line);
 760         if (pktlen != len)
 761                 loginfo("Extended attributes (%d bytes) exist <%.*s>",
 762                         (int) pktlen - len,
 763                         (int) pktlen - len, line + len + 1);
 764         if (len && line[len-1] == '\n') {
 765                 line[--len] = 0;
 766                 pktlen--;
 767         }
 768
 769         /* parse additional args hidden behind a NUL byte */
 770         if (len != pktlen)
 771                 parse_extra_args(&hi, &env, line + len + 1, pktlen - len - 1);
 772
 773         for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
 774                 struct daemon_service *s = &(daemon_service[i]);
 775                 const char *arg;
 776
 777                 if (skip_prefix(line, "git-", &arg) &&
 778                     skip_prefix(arg, s->name, &arg) &&
 779                     *arg++ == ' ') {
 780                         /*
 781                          * Note: The directory here is probably context sensitive,
 782                          * and might depend on the actual service being performed.
 783                          */
 784                         int rc = run_service(arg, s, &hi, &env);
 785                         hostinfo_clear(&hi);
 786                         argv_array_clear(&env);
 787                         return rc;
 788                 }
 789         }
 790
 791         hostinfo_clear(&hi);
 792         argv_array_clear(&env);
 793         logerror("Protocol error: '%s'", line);
 794         return -1;
 795 }
 796
 797 static int addrcmp(const struct sockaddr_storage *s1,
 798     const struct sockaddr_storage *s2)
 799 {
 800         const struct sockaddr *sa1 = (const struct sockaddr*) s1;
 801         const struct sockaddr *sa2 = (const struct sockaddr*) s2;
 802
 803         if (sa1->sa_family != sa2->sa_family)
 804                 return sa1->sa_family - sa2->sa_family;
 805         if (sa1->sa_family == AF_INET)
 806                 return memcmp(&((struct sockaddr_in *)s1)->sin_addr,
 807                     &((struct sockaddr_in *)s2)->sin_addr,
 808                     sizeof(struct in_addr));
 809 #ifndef NO_IPV6
 810         if (sa1->sa_family == AF_INET6)
 811                 return memcmp(&((struct sockaddr_in6 *)s1)->sin6_addr,
 812                     &((struct sockaddr_in6 *)s2)->sin6_addr,
 813                     sizeof(struct in6_addr));
 814 #endif
 815         return 0;
 816 }
 817
 818 static int max_connections = 32;
 819
 820 static unsigned int live_children;
 821
 822 static struct child {
 823         struct child *next;
 824         struct child_process cld;
 825         struct sockaddr_storage address;
 826 } *firstborn;
 827
 828 static void add_child(struct child_process *cld, struct sockaddr *addr, socklen_t addrlen)
 829 {
 830         struct child *newborn, **cradle;
 831
 832         newborn = xcalloc(1, sizeof(*newborn));
 833         live_children++;
 834         memcpy(&newborn->cld, cld, sizeof(*cld));
 835         memcpy(&newborn->address, addr, addrlen);
 836         for (cradle = &firstborn; *cradle; cradle = &(*cradle)->next)
 837                 if (!addrcmp(&(*cradle)->address, &newborn->address))
 838                         break;
 839         newborn->next = *cradle;
 840         *cradle = newborn;
 841 }
 842
 843 /*
 844  * This gets called if the number of connections grows
 845  * past "max_connections".
 846  *
 847  * We kill the newest connection from a duplicate IP.
 848  */
 849 static void kill_some_child(void)
 850 {
 851         const struct child *blanket, *next;
 852
 853         if (!(blanket = firstborn))
 854                 return;
 855
 856         for (; (next = blanket->next); blanket = next)
 857                 if (!addrcmp(&blanket->address, &next->address)) {
 858                         kill(blanket->cld.pid, SIGTERM);
 859                         break;
 860                 }
 861 }
 862
 863 static void check_dead_children(void)
 864 {
 865         int status;
 866         pid_t pid;
 867
 868         struct child **cradle, *blanket;
 869         for (cradle = &firstborn; (blanket = *cradle);)
 870                 if ((pid = waitpid(blanket->cld.pid, &status, WNOHANG)) > 1) {
 871                         const char *dead = "";
 872                         if (status)
 873                                 dead = " (with error)";
 874                         loginfo("[%"PRIuMAX"] Disconnected%s", (uintmax_t)pid, dead);
 875
 876                         /* remove the child */
 877                         *cradle = blanket->next;
 878                         live_children--;
 879                         child_process_clear(&blanket->cld);
 880                         free(blanket);
 881                 } else
 882                         cradle = &blanket->next;
 883 }
 884
 885 static struct argv_array cld_argv = ARGV_ARRAY_INIT;
 886 static void handle(int incoming, struct sockaddr *addr, socklen_t addrlen)
 887 {
 888         struct child_process cld = CHILD_PROCESS_INIT;
 889
 890         if (max_connections && live_children >= max_connections) {
 891                 kill_some_child();
 892                 sleep(1);  /* give it some time to die */
 893                 check_dead_children();
 894                 if (live_children >= max_connections) {
 895                         close(incoming);
 896                         logerror("Too many children, dropping connection");
 897                         return;
 898                 }
 899         }
 900
 901         if (addr->sa_family == AF_INET) {
 902                 char buf[128] = "";
 903                 struct sockaddr_in *sin_addr = (void *) addr;
 904                 inet_ntop(addr->sa_family, &sin_addr->sin_addr, buf, sizeof(buf));
 905                 argv_array_pushf(&cld.env_array, "REMOTE_ADDR=%s", buf);
 906                 argv_array_pushf(&cld.env_array, "REMOTE_PORT=%d",
 907                                  ntohs(sin_addr->sin_port));
 908 #ifndef NO_IPV6
 909         } else if (addr->sa_family == AF_INET6) {
 910                 char buf[128] = "";
 911                 struct sockaddr_in6 *sin6_addr = (void *) addr;
 912                 inet_ntop(AF_INET6, &sin6_addr->sin6_addr, buf, sizeof(buf));
 913                 argv_array_pushf(&cld.env_array, "REMOTE_ADDR=[%s]", buf);
 914                 argv_array_pushf(&cld.env_array, "REMOTE_PORT=%d",
 915                                  ntohs(sin6_addr->sin6_port));
 916 #endif
 917         }
 918
 919         cld.argv = cld_argv.argv;
 920         cld.in = incoming;
 921         cld.out = dup(incoming);
 922
 923         if (start_command(&cld))
 924                 logerror("unable to fork");
 925         else
 926                 add_child(&cld, addr, addrlen);
 927 }
 928
 929 static void child_handler(int signo)
 930 {
 931         /*
 932          * Otherwise empty handler because systemcalls will get interrupted
 933          * upon signal receipt
 934          * SysV needs the handler to be rearmed
 935          */
 936         signal(SIGCHLD, child_handler);
 937 }
 938
 939 static int set_reuse_addr(int sockfd)
 940 {
 941         int on = 1;
 942
 943         if (!reuseaddr)
 944                 return 0;
 945         return setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR,
 946                           &on, sizeof(on));
 947 }
 948
 949 struct socketlist {
 950         int *list;
 951         size_t nr;
 952         size_t alloc;
 953 };
 954
 955 static const char *ip2str(int family, struct sockaddr *sin, socklen_t len)
 956 {
 957 #ifdef NO_IPV6
 958         static char ip[INET_ADDRSTRLEN];
 959 #else
 960         static char ip[INET6_ADDRSTRLEN];
 961 #endif
 962
 963         switch (family) {
 964 #ifndef NO_IPV6
 965         case AF_INET6:
 966                 inet_ntop(family, &((struct sockaddr_in6*)sin)->sin6_addr, ip, len);
 967                 break;
 968 #endif
 969         case AF_INET:
 970                 inet_ntop(family, &((struct sockaddr_in*)sin)->sin_addr, ip, len);
 971                 break;
 972         default:
 973                 xsnprintf(ip, sizeof(ip), "<unknown>");
 974         }
 975         return ip;
 976 }
 977
 978 #ifndef NO_IPV6
 979
 980 static int setup_named_sock(char *listen_addr, int listen_port, struct socketlist *socklist)
 981 {
 982         int socknum = 0;
 983         char pbuf[NI_MAXSERV];
 984         struct addrinfo hints, *ai0, *ai;
 985         int gai;
 986         long flags;
 987
 988         xsnprintf(pbuf, sizeof(pbuf), "%d", listen_port);
 989         memset(&hints, 0, sizeof(hints));
 990         hints.ai_family = AF_UNSPEC;
 991         hints.ai_socktype = SOCK_STREAM;
 992         hints.ai_protocol = IPPROTO_TCP;
 993         hints.ai_flags = AI_PASSIVE;
 994
 995         gai = getaddrinfo(listen_addr, pbuf, &hints, &ai0);
 996         if (gai) {
 997                 logerror("getaddrinfo() for %s failed: %s", listen_addr, gai_strerror(gai));
 998                 return 0;
 999         }
1000
1001         for (ai = ai0; ai; ai = ai->ai_next) {
1002                 int sockfd;
1003
1004                 sockfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1005                 if (sockfd < 0)
1006                         continue;
1007                 if (sockfd >= FD_SETSIZE) {
1008                         logerror("Socket descriptor too large");
1009                         close(sockfd);
1010                         continue;
1011                 }
1012
1013 #ifdef IPV6_V6ONLY
1014                 if (ai->ai_family == AF_INET6) {
1015                         int on = 1;
1016                         setsockopt(sockfd, IPPROTO_IPV6, IPV6_V6ONLY,
1017                                    &on, sizeof(on));
1018                         /* Note: error is not fatal */
1019                 }
1020 #endif
1021
1022                 if (set_reuse_addr(sockfd)) {
1023                         logerror("Could not set SO_REUSEADDR: %s", strerror(errno));
1024                         close(sockfd);
1025                         continue;
1026                 }
1027
1028                 set_keep_alive(sockfd);
1029
1030                 if (bind(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
1031                         logerror("Could not bind to %s: %s",
1032                                  ip2str(ai->ai_family, ai->ai_addr, ai->ai_addrlen),
1033                                  strerror(errno));
1034                         close(sockfd);
1035                         continue;       /* not fatal */
1036                 }
1037                 if (listen(sockfd, 5) < 0) {
1038                         logerror("Could not listen to %s: %s",
1039                                  ip2str(ai->ai_family, ai->ai_addr, ai->ai_addrlen),
1040                                  strerror(errno));
1041                         close(sockfd);
1042                         continue;       /* not fatal */
1043                 }
1044
1045                 flags = fcntl(sockfd, F_GETFD, 0);
1046                 if (flags >= 0)
1047                         fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
1048
1049                 ALLOC_GROW(socklist->list, socklist->nr + 1, socklist->alloc);
1050                 socklist->list[socklist->nr++] = sockfd;
1051                 socknum++;
1052         }
1053
1054         freeaddrinfo(ai0);
1055
1056         return socknum;
1057 }
1058
1059 #else /* NO_IPV6 */
1060
1061 static int setup_named_sock(char *listen_addr, int listen_port, struct socketlist *socklist)
1062 {
1063         struct sockaddr_in sin;
1064         int sockfd;
1065         long flags;
1066
1067         memset(&sin, 0, sizeof sin);
1068         sin.sin_family = AF_INET;
1069         sin.sin_port = htons(listen_port);
1070
1071         if (listen_addr) {
1072                 /* Well, host better be an IP address here. */
1073                 if (inet_pton(AF_INET, listen_addr, &sin.sin_addr.s_addr) <= 0)
1074                         return 0;
1075         } else {
1076                 sin.sin_addr.s_addr = htonl(INADDR_ANY);
1077         }
1078
1079         sockfd = socket(AF_INET, SOCK_STREAM, 0);
1080         if (sockfd < 0)
1081                 return 0;
1082
1083         if (set_reuse_addr(sockfd)) {
1084                 logerror("Could not set SO_REUSEADDR: %s", strerror(errno));
1085                 close(sockfd);
1086                 return 0;
1087         }
1088
1089         set_keep_alive(sockfd);
1090
1091         if ( bind(sockfd, (struct sockaddr *)&sin, sizeof sin) < 0 ) {
1092                 logerror("Could not bind to %s: %s",
1093                          ip2str(AF_INET, (struct sockaddr *)&sin, sizeof(sin)),
1094                          strerror(errno));
1095                 close(sockfd);
1096                 return 0;
1097         }
1098
1099         if (listen(sockfd, 5) < 0) {
1100                 logerror("Could not listen to %s: %s",
1101                          ip2str(AF_INET, (struct sockaddr *)&sin, sizeof(sin)),
1102                          strerror(errno));
1103                 close(sockfd);
1104                 return 0;
1105         }
1106
1107         flags = fcntl(sockfd, F_GETFD, 0);
1108         if (flags >= 0)
1109                 fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
1110
1111         ALLOC_GROW(socklist->list, socklist->nr + 1, socklist->alloc);
1112         socklist->list[socklist->nr++] = sockfd;
1113         return 1;
1114 }
1115
1116 #endif
1117
1118 static void socksetup(struct string_list *listen_addr, int listen_port, struct socketlist *socklist)
1119 {
1120         if (!listen_addr->nr)
1121                 setup_named_sock(NULL, listen_port, socklist);
1122         else {
1123                 int i, socknum;
1124                 for (i = 0; i < listen_addr->nr; i++) {
1125                         socknum = setup_named_sock(listen_addr->items[i].string,
1126                                                    listen_port, socklist);
1127
1128                         if (socknum == 0)
1129                                 logerror("unable to allocate any listen sockets for host %s on port %u",
1130                                          listen_addr->items[i].string, listen_port);
1131                 }
1132         }
1133 }
1134
1135 static int service_loop(struct socketlist *socklist)
1136 {
1137         struct pollfd *pfd;
1138         int i;
1139
1140         pfd = xcalloc(socklist->nr, sizeof(struct pollfd));
1141
1142         for (i = 0; i < socklist->nr; i++) {
1143                 pfd[i].fd = socklist->list[i];
1144                 pfd[i].events = POLLIN;
1145         }
1146
1147         signal(SIGCHLD, child_handler);
1148
1149         for (;;) {
1150                 int i;
1151
1152                 check_dead_children();
1153
1154                 if (poll(pfd, socklist->nr, -1) < 0) {
1155                         if (errno != EINTR) {
1156                                 logerror("Poll failed, resuming: %s",
1157                                       strerror(errno));
1158                                 sleep(1);
1159                         }
1160                         continue;
1161                 }
1162
1163                 for (i = 0; i < socklist->nr; i++) {
1164                         if (pfd[i].revents & POLLIN) {
1165                                 union {
1166                                         struct sockaddr sa;
1167                                         struct sockaddr_in sai;
1168 #ifndef NO_IPV6
1169                                         struct sockaddr_in6 sai6;
1170 #endif
1171                                 } ss;
1172                                 socklen_t sslen = sizeof(ss);
1173                                 int incoming = accept(pfd[i].fd, &ss.sa, &sslen);
1174                                 if (incoming < 0) {
1175                                         switch (errno) {
1176                                         case EAGAIN:
1177                                         case EINTR:
1178                                         case ECONNABORTED:
1179                                                 continue;
1180                                         default:
1181                                                 die_errno("accept returned");
1182                                         }
1183                                 }
1184                                 handle(incoming, &ss.sa, sslen);
1185                         }
1186                 }
1187         }
1188 }
1189
1190 #ifdef NO_POSIX_GOODIES
1191
1192 struct credentials;
1193
1194 static void drop_privileges(struct credentials *cred)
1195 {
1196         /* nothing */
1197 }
1198
1199 static struct credentials *prepare_credentials(const char *user_name,
1200     const char *group_name)
1201 {
1202         die("--user not supported on this platform");
1203 }
1204
1205 #else
1206
1207 struct credentials {
1208         struct passwd *pass;
1209         gid_t gid;
1210 };
1211
1212 static void drop_privileges(struct credentials *cred)
1213 {
1214         if (cred && (initgroups(cred->pass->pw_name, cred->gid) ||
1215             setgid (cred->gid) || setuid(cred->pass->pw_uid)))
1216                 die("cannot drop privileges");
1217 }
1218
1219 static struct credentials *prepare_credentials(const char *user_name,
1220     const char *group_name)
1221 {
1222         static struct credentials c;
1223
1224         c.pass = getpwnam(user_name);
1225         if (!c.pass)
1226                 die("user not found - %s", user_name);
1227
1228         if (!group_name)
1229                 c.gid = c.pass->pw_gid;
1230         else {
1231                 struct group *group = getgrnam(group_name);
1232                 if (!group)
1233                         die("group not found - %s", group_name);
1234
1235                 c.gid = group->gr_gid;
1236         }
1237
1238         return &c;
1239 }
1240 #endif
1241
1242 static int serve(struct string_list *listen_addr, int listen_port,
1243     struct credentials *cred)
1244 {
1245         struct socketlist socklist = { NULL, 0, 0 };
1246
1247         socksetup(listen_addr, listen_port, &socklist);
1248         if (socklist.nr == 0)
1249                 die("unable to allocate any listen sockets on port %u",
1250                     listen_port);
1251
1252         drop_privileges(cred);
1253
1254         loginfo("Ready to rumble");
1255
1256         return service_loop(&socklist);
1257 }
1258
1259 int cmd_main(int argc, const char **argv)
1260 {
1261         int listen_port = 0;
1262         struct string_list listen_addr = STRING_LIST_INIT_NODUP;
1263         int serve_mode = 0, inetd_mode = 0;
1264         const char *pid_file = NULL, *user_name = NULL, *group_name = NULL;
1265         int detach = 0;
1266         struct credentials *cred = NULL;
1267         int i;
1268
1269         for (i = 1; i < argc; i++) {
1270                 const char *arg = argv[i];
1271                 const char *v;
1272
1273                 if (skip_prefix(arg, "--listen=", &v)) {
1274                         string_list_append(&listen_addr, xstrdup_tolower(v));
1275                         continue;
1276                 }
1277                 if (skip_prefix(arg, "--port=", &v)) {
1278                         char *end;
1279                         unsigned long n;
1280                         n = strtoul(v, &end, 0);
1281                         if (*v && !*end) {
1282                                 listen_port = n;
1283                                 continue;
1284                         }
1285                 }
1286                 if (!strcmp(arg, "--serve")) {
1287                         serve_mode = 1;
1288                         continue;
1289                 }
1290                 if (!strcmp(arg, "--inetd")) {
1291                         inetd_mode = 1;
1292                         log_syslog = 1;
1293                         continue;
1294                 }
1295                 if (!strcmp(arg, "--verbose")) {
1296                         verbose = 1;
1297                         continue;
1298                 }
1299                 if (!strcmp(arg, "--syslog")) {
1300                         log_syslog = 1;
1301                         continue;
1302                 }
1303                 if (!strcmp(arg, "--export-all")) {
1304                         export_all_trees = 1;
1305                         continue;
1306                 }
1307                 if (skip_prefix(arg, "--access-hook=", &v)) {
1308                         access_hook = v;
1309                         continue;
1310                 }
1311                 if (skip_prefix(arg, "--timeout=", &v)) {
1312                         timeout = atoi(v);
1313                         continue;
1314                 }
1315                 if (skip_prefix(arg, "--init-timeout=", &v)) {
1316                         init_timeout = atoi(v);
1317                         continue;
1318                 }
1319                 if (skip_prefix(arg, "--max-connections=", &v)) {
1320                         max_connections = atoi(v);
1321                         if (max_connections < 0)
1322                                 max_connections = 0;            /* unlimited */
1323                         continue;
1324                 }
1325                 if (!strcmp(arg, "--strict-paths")) {
1326                         strict_paths = 1;
1327                         continue;
1328                 }
1329                 if (skip_prefix(arg, "--base-path=", &v)) {
1330                         base_path = v;
1331                         continue;
1332                 }
1333                 if (!strcmp(arg, "--base-path-relaxed")) {
1334                         base_path_relaxed = 1;
1335                         continue;
1336                 }
1337                 if (skip_prefix(arg, "--interpolated-path=", &v)) {
1338                         interpolated_path = v;
1339                         continue;
1340                 }
1341                 if (!strcmp(arg, "--reuseaddr")) {
1342                         reuseaddr = 1;
1343                         continue;
1344                 }
1345                 if (!strcmp(arg, "--user-path")) {
1346                         user_path = "";
1347                         continue;
1348                 }
1349                 if (skip_prefix(arg, "--user-path=", &v)) {
1350                         user_path = v;
1351                         continue;
1352                 }
1353                 if (skip_prefix(arg, "--pid-file=", &v)) {
1354                         pid_file = v;
1355                         continue;
1356                 }
1357                 if (!strcmp(arg, "--detach")) {
1358                         detach = 1;
1359                         log_syslog = 1;
1360                         continue;
1361                 }
1362                 if (skip_prefix(arg, "--user=", &v)) {
1363                         user_name = v;
1364                         continue;
1365                 }
1366                 if (skip_prefix(arg, "--group=", &v)) {
1367                         group_name = v;
1368                         continue;
1369                 }
1370                 if (skip_prefix(arg, "--enable=", &v)) {
1371                         enable_service(v, 1);
1372                         continue;
1373                 }
1374                 if (skip_prefix(arg, "--disable=", &v)) {
1375                         enable_service(v, 0);
1376                         continue;
1377                 }
1378                 if (skip_prefix(arg, "--allow-override=", &v)) {
1379                         make_service_overridable(v, 1);
1380                         continue;
1381                 }
1382                 if (skip_prefix(arg, "--forbid-override=", &v)) {
1383                         make_service_overridable(v, 0);
1384                         continue;
1385                 }
1386                 if (!strcmp(arg, "--informative-errors")) {
1387                         informative_errors = 1;
1388                         continue;
1389                 }
1390                 if (!strcmp(arg, "--no-informative-errors")) {
1391                         informative_errors = 0;
1392                         continue;
1393                 }
1394                 if (!strcmp(arg, "--")) {
1395                         ok_paths = &argv[i+1];
1396                         break;
1397                 } else if (arg[0] != '-') {
1398                         ok_paths = &argv[i];
1399                         break;
1400                 }
1401
1402                 usage(daemon_usage);
1403         }
1404
1405         if (log_syslog) {
1406                 openlog("git-daemon", LOG_PID, LOG_DAEMON);
1407                 set_die_routine(daemon_die);
1408         } else
1409                 /* avoid splitting a message in the middle */
1410                 setvbuf(stderr, NULL, _IOFBF, 4096);
1411
1412         if (inetd_mode && (detach || group_name || user_name))
1413                 die("--detach, --user and --group are incompatible with --inetd");
1414
1415         if (inetd_mode && (listen_port || (listen_addr.nr > 0)))
1416                 die("--listen= and --port= are incompatible with --inetd");
1417         else if (listen_port == 0)
1418                 listen_port = DEFAULT_GIT_PORT;
1419
1420         if (group_name && !user_name)
1421                 die("--group supplied without --user");
1422
1423         if (user_name)
1424                 cred = prepare_credentials(user_name, group_name);
1425
1426         if (strict_paths && (!ok_paths || !*ok_paths))
1427                 die("option --strict-paths requires a whitelist");
1428
1429         if (base_path && !is_directory(base_path))
1430                 die("base-path '%s' does not exist or is not a directory",
1431                     base_path);
1432
1433         if (inetd_mode) {
1434                 if (!freopen("/dev/null", "w", stderr))
1435                         die_errno("failed to redirect stderr to /dev/null");
1436         }
1437
1438         if (inetd_mode || serve_mode)
1439                 return execute();
1440
1441         if (detach) {
1442                 if (daemonize())
1443                         die("--detach not supported on this platform");
1444         }
1445
1446         if (pid_file)
1447                 write_file(pid_file, "%"PRIuMAX, (uintmax_t) getpid());
1448
1449         /* prepare argv for serving-processes */
1450         argv_array_push(&cld_argv, argv[0]); /* git-daemon */
1451         argv_array_push(&cld_argv, "--serve");
1452         for (i = 1; i < argc; ++i)
1453                 argv_array_push(&cld_argv, argv[i]);
1454
1455         return serve(&listen_addr, listen_port, cred);
1456 }