git.oblomov.eu Git - git/blob - 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                         loginfo("Extended attribute \"host\": %s", val);
 601                         if (*val) {
 602                                 /* Split <host>:<port> at colon. */
 603                                 char *host;
 604                                 char *port;
 605                                 parse_host_and_port(val, &host, &port);
 606                                 if (port)
 607                                         sanitize_client(&hi->tcp_port, port);
 608                                 canonicalize_client(&hi->hostname, host);
 609                                 hi->hostname_lookup_done = 0;
 610                         }
 611
 612                         /* On to the next one */
 613                         extra_args = val + vallen;
 614                 }
 615                 if (extra_args < end && *extra_args)
 616                         die("Invalid request");
 617         }
 618
 619         return extra_args;
 620 }
 621
 622 static void parse_extra_args(struct hostinfo *hi, struct argv_array *env,
 623                              char *extra_args, int buflen)
 624 {
 625         const char *end = extra_args + buflen;
 626         struct strbuf git_protocol = STRBUF_INIT;
 627
 628         /* First look for the host argument */
 629         extra_args = parse_host_arg(hi, extra_args, buflen);
 630
 631         /* Look for additional arguments places after a second NUL byte */
 632         for (; extra_args < end; extra_args += strlen(extra_args) + 1) {
 633                 const char *arg = extra_args;
 634
 635                 /*
 636                  * Parse the extra arguments, adding most to 'git_protocol'
 637                  * which will be used to set the 'GIT_PROTOCOL' envvar in the
 638                  * service that will be run.
 639                  *
 640                  * If there ends up being a particular arg in the future that
 641                  * git-daemon needs to parse specificly (like the 'host' arg)
 642                  * then it can be parsed here and not added to 'git_protocol'.
 643                  */
 644                 if (*arg) {
 645                         if (git_protocol.len > 0)
 646                                 strbuf_addch(&git_protocol, ':');
 647                         strbuf_addstr(&git_protocol, arg);
 648                 }
 649         }
 650
 651         if (git_protocol.len > 0) {
 652                 loginfo("Extended attribute \"protocol\": %s", git_protocol.buf);
 653                 argv_array_pushf(env, GIT_PROTOCOL_ENVIRONMENT "=%s",
 654                                  git_protocol.buf);
 655         }
 656         strbuf_release(&git_protocol);
 657 }
 658
 659 /*
 660  * Locate canonical hostname and its IP address.
 661  */
 662 static void lookup_hostname(struct hostinfo *hi)
 663 {
 664         if (!hi->hostname_lookup_done && hi->hostname.len) {
 665 #ifndef NO_IPV6
 666                 struct addrinfo hints;
 667                 struct addrinfo *ai;
 668                 int gai;
 669                 static char addrbuf[HOST_NAME_MAX + 1];
 670
 671                 memset(&hints, 0, sizeof(hints));
 672                 hints.ai_flags = AI_CANONNAME;
 673
 674                 gai = getaddrinfo(hi->hostname.buf, NULL, &hints, &ai);
 675                 if (!gai) {
 676                         struct sockaddr_in *sin_addr = (void *)ai->ai_addr;
 677
 678                         inet_ntop(AF_INET, &sin_addr->sin_addr,
 679                                   addrbuf, sizeof(addrbuf));
 680                         strbuf_addstr(&hi->ip_address, addrbuf);
 681
 682                         if (ai->ai_canonname)
 683                                 sanitize_client(&hi->canon_hostname,
 684                                                 ai->ai_canonname);
 685                         else
 686                                 strbuf_addbuf(&hi->canon_hostname,
 687                                               &hi->ip_address);
 688
 689                         freeaddrinfo(ai);
 690                 }
 691 #else
 692                 struct hostent *hent;
 693                 struct sockaddr_in sa;
 694                 char **ap;
 695                 static char addrbuf[HOST_NAME_MAX + 1];
 696
 697                 hent = gethostbyname(hi->hostname.buf);
 698                 if (hent) {
 699                         ap = hent->h_addr_list;
 700                         memset(&sa, 0, sizeof sa);
 701                         sa.sin_family = hent->h_addrtype;
 702                         sa.sin_port = htons(0);
 703                         memcpy(&sa.sin_addr, *ap, hent->h_length);
 704
 705                         inet_ntop(hent->h_addrtype, &sa.sin_addr,
 706                                   addrbuf, sizeof(addrbuf));
 707
 708                         sanitize_client(&hi->canon_hostname, hent->h_name);
 709                         strbuf_addstr(&hi->ip_address, addrbuf);
 710                 }
 711 #endif
 712                 hi->hostname_lookup_done = 1;
 713         }
 714 }
 715
 716 static void hostinfo_init(struct hostinfo *hi)
 717 {
 718         memset(hi, 0, sizeof(*hi));
 719         strbuf_init(&hi->hostname, 0);
 720         strbuf_init(&hi->canon_hostname, 0);
 721         strbuf_init(&hi->ip_address, 0);
 722         strbuf_init(&hi->tcp_port, 0);
 723 }
 724
 725 static void hostinfo_clear(struct hostinfo *hi)
 726 {
 727         strbuf_release(&hi->hostname);
 728         strbuf_release(&hi->canon_hostname);
 729         strbuf_release(&hi->ip_address);
 730         strbuf_release(&hi->tcp_port);
 731 }
 732
 733 static void set_keep_alive(int sockfd)
 734 {
 735         int ka = 1;
 736
 737         if (setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, &ka, sizeof(ka)) < 0) {
 738                 if (errno != ENOTSOCK)
 739                         logerror("unable to set SO_KEEPALIVE on socket: %s",
 740                                 strerror(errno));
 741         }
 742 }
 743
 744 static int execute(void)
 745 {
 746         char *line = packet_buffer;
 747         int pktlen, len, i;
 748         char *addr = getenv("REMOTE_ADDR"), *port = getenv("REMOTE_PORT");
 749         struct hostinfo hi;
 750         struct argv_array env = ARGV_ARRAY_INIT;
 751
 752         hostinfo_init(&hi);
 753
 754         if (addr)
 755                 loginfo("Connection from %s:%s", addr, port);
 756
 757         set_keep_alive(0);
 758         alarm(init_timeout ? init_timeout : timeout);
 759         pktlen = packet_read(0, NULL, NULL, packet_buffer, sizeof(packet_buffer), 0);
 760         alarm(0);
 761
 762         len = strlen(line);
 763         if (len && line[len-1] == '\n')
 764                 line[len-1] = 0;
 765
 766         /* parse additional args hidden behind a NUL byte */
 767         if (len != pktlen)
 768                 parse_extra_args(&hi, &env, line + len + 1, pktlen - len - 1);
 769
 770         for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
 771                 struct daemon_service *s = &(daemon_service[i]);
 772                 const char *arg;
 773
 774                 if (skip_prefix(line, "git-", &arg) &&
 775                     skip_prefix(arg, s->name, &arg) &&
 776                     *arg++ == ' ') {
 777                         /*
 778                          * Note: The directory here is probably context sensitive,
 779                          * and might depend on the actual service being performed.
 780                          */
 781                         int rc = run_service(arg, s, &hi, &env);
 782                         hostinfo_clear(&hi);
 783                         argv_array_clear(&env);
 784                         return rc;
 785                 }
 786         }
 787
 788         hostinfo_clear(&hi);
 789         argv_array_clear(&env);
 790         logerror("Protocol error: '%s'", line);
 791         return -1;
 792 }
 793
 794 static int addrcmp(const struct sockaddr_storage *s1,
 795     const struct sockaddr_storage *s2)
 796 {
 797         const struct sockaddr *sa1 = (const struct sockaddr*) s1;
 798         const struct sockaddr *sa2 = (const struct sockaddr*) s2;
 799
 800         if (sa1->sa_family != sa2->sa_family)
 801                 return sa1->sa_family - sa2->sa_family;
 802         if (sa1->sa_family == AF_INET)
 803                 return memcmp(&((struct sockaddr_in *)s1)->sin_addr,
 804                     &((struct sockaddr_in *)s2)->sin_addr,
 805                     sizeof(struct in_addr));
 806 #ifndef NO_IPV6
 807         if (sa1->sa_family == AF_INET6)
 808                 return memcmp(&((struct sockaddr_in6 *)s1)->sin6_addr,
 809                     &((struct sockaddr_in6 *)s2)->sin6_addr,
 810                     sizeof(struct in6_addr));
 811 #endif
 812         return 0;
 813 }
 814
 815 static int max_connections = 32;
 816
 817 static unsigned int live_children;
 818
 819 static struct child {
 820         struct child *next;
 821         struct child_process cld;
 822         struct sockaddr_storage address;
 823 } *firstborn;
 824
 825 static void add_child(struct child_process *cld, struct sockaddr *addr, socklen_t addrlen)
 826 {
 827         struct child *newborn, **cradle;
 828
 829         newborn = xcalloc(1, sizeof(*newborn));
 830         live_children++;
 831         memcpy(&newborn->cld, cld, sizeof(*cld));
 832         memcpy(&newborn->address, addr, addrlen);
 833         for (cradle = &firstborn; *cradle; cradle = &(*cradle)->next)
 834                 if (!addrcmp(&(*cradle)->address, &newborn->address))
 835                         break;
 836         newborn->next = *cradle;
 837         *cradle = newborn;
 838 }
 839
 840 /*
 841  * This gets called if the number of connections grows
 842  * past "max_connections".
 843  *
 844  * We kill the newest connection from a duplicate IP.
 845  */
 846 static void kill_some_child(void)
 847 {
 848         const struct child *blanket, *next;
 849
 850         if (!(blanket = firstborn))
 851                 return;
 852
 853         for (; (next = blanket->next); blanket = next)
 854                 if (!addrcmp(&blanket->address, &next->address)) {
 855                         kill(blanket->cld.pid, SIGTERM);
 856                         break;
 857                 }
 858 }
 859
 860 static void check_dead_children(void)
 861 {
 862         int status;
 863         pid_t pid;
 864
 865         struct child **cradle, *blanket;
 866         for (cradle = &firstborn; (blanket = *cradle);)
 867                 if ((pid = waitpid(blanket->cld.pid, &status, WNOHANG)) > 1) {
 868                         const char *dead = "";
 869                         if (status)
 870                                 dead = " (with error)";
 871                         loginfo("[%"PRIuMAX"] Disconnected%s", (uintmax_t)pid, dead);
 872
 873                         /* remove the child */
 874                         *cradle = blanket->next;
 875                         live_children--;
 876                         child_process_clear(&blanket->cld);
 877                         free(blanket);
 878                 } else
 879                         cradle = &blanket->next;
 880 }
 881
 882 static struct argv_array cld_argv = ARGV_ARRAY_INIT;
 883 static void handle(int incoming, struct sockaddr *addr, socklen_t addrlen)
 884 {
 885         struct child_process cld = CHILD_PROCESS_INIT;
 886
 887         if (max_connections && live_children >= max_connections) {
 888                 kill_some_child();
 889                 sleep(1);  /* give it some time to die */
 890                 check_dead_children();
 891                 if (live_children >= max_connections) {
 892                         close(incoming);
 893                         logerror("Too many children, dropping connection");
 894                         return;
 895                 }
 896         }
 897
 898         if (addr->sa_family == AF_INET) {
 899                 char buf[128] = "";
 900                 struct sockaddr_in *sin_addr = (void *) addr;
 901                 inet_ntop(addr->sa_family, &sin_addr->sin_addr, buf, sizeof(buf));
 902                 argv_array_pushf(&cld.env_array, "REMOTE_ADDR=%s", buf);
 903                 argv_array_pushf(&cld.env_array, "REMOTE_PORT=%d",
 904                                  ntohs(sin_addr->sin_port));
 905 #ifndef NO_IPV6
 906         } else if (addr->sa_family == AF_INET6) {
 907                 char buf[128] = "";
 908                 struct sockaddr_in6 *sin6_addr = (void *) addr;
 909                 inet_ntop(AF_INET6, &sin6_addr->sin6_addr, buf, sizeof(buf));
 910                 argv_array_pushf(&cld.env_array, "REMOTE_ADDR=[%s]", buf);
 911                 argv_array_pushf(&cld.env_array, "REMOTE_PORT=%d",
 912                                  ntohs(sin6_addr->sin6_port));
 913 #endif
 914         }
 915
 916         cld.argv = cld_argv.argv;
 917         cld.in = incoming;
 918         cld.out = dup(incoming);
 919
 920         if (start_command(&cld))
 921                 logerror("unable to fork");
 922         else
 923                 add_child(&cld, addr, addrlen);
 924 }
 925
 926 static void child_handler(int signo)
 927 {
 928         /*
 929          * Otherwise empty handler because systemcalls will get interrupted
 930          * upon signal receipt
 931          * SysV needs the handler to be rearmed
 932          */
 933         signal(SIGCHLD, child_handler);
 934 }
 935
 936 static int set_reuse_addr(int sockfd)
 937 {
 938         int on = 1;
 939
 940         if (!reuseaddr)
 941                 return 0;
 942         return setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR,
 943                           &on, sizeof(on));
 944 }
 945
 946 struct socketlist {
 947         int *list;
 948         size_t nr;
 949         size_t alloc;
 950 };
 951
 952 static const char *ip2str(int family, struct sockaddr *sin, socklen_t len)
 953 {
 954 #ifdef NO_IPV6
 955         static char ip[INET_ADDRSTRLEN];
 956 #else
 957         static char ip[INET6_ADDRSTRLEN];
 958 #endif
 959
 960         switch (family) {
 961 #ifndef NO_IPV6
 962         case AF_INET6:
 963                 inet_ntop(family, &((struct sockaddr_in6*)sin)->sin6_addr, ip, len);
 964                 break;
 965 #endif
 966         case AF_INET:
 967                 inet_ntop(family, &((struct sockaddr_in*)sin)->sin_addr, ip, len);
 968                 break;
 969         default:
 970                 xsnprintf(ip, sizeof(ip), "<unknown>");
 971         }
 972         return ip;
 973 }
 974
 975 #ifndef NO_IPV6
 976
 977 static int setup_named_sock(char *listen_addr, int listen_port, struct socketlist *socklist)
 978 {
 979         int socknum = 0;
 980         char pbuf[NI_MAXSERV];
 981         struct addrinfo hints, *ai0, *ai;
 982         int gai;
 983         long flags;
 984
 985         xsnprintf(pbuf, sizeof(pbuf), "%d", listen_port);
 986         memset(&hints, 0, sizeof(hints));
 987         hints.ai_family = AF_UNSPEC;
 988         hints.ai_socktype = SOCK_STREAM;
 989         hints.ai_protocol = IPPROTO_TCP;
 990         hints.ai_flags = AI_PASSIVE;
 991
 992         gai = getaddrinfo(listen_addr, pbuf, &hints, &ai0);
 993         if (gai) {
 994                 logerror("getaddrinfo() for %s failed: %s", listen_addr, gai_strerror(gai));
 995                 return 0;
 996         }
 997
 998         for (ai = ai0; ai; ai = ai->ai_next) {
 999                 int sockfd;
1000
1001                 sockfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1002                 if (sockfd < 0)
1003                         continue;
1004                 if (sockfd >= FD_SETSIZE) {
1005                         logerror("Socket descriptor too large");
1006                         close(sockfd);
1007                         continue;
1008                 }
1009
1010 #ifdef IPV6_V6ONLY
1011                 if (ai->ai_family == AF_INET6) {
1012                         int on = 1;
1013                         setsockopt(sockfd, IPPROTO_IPV6, IPV6_V6ONLY,
1014                                    &on, sizeof(on));
1015                         /* Note: error is not fatal */
1016                 }
1017 #endif
1018
1019                 if (set_reuse_addr(sockfd)) {
1020                         logerror("Could not set SO_REUSEADDR: %s", strerror(errno));
1021                         close(sockfd);
1022                         continue;
1023                 }
1024
1025                 set_keep_alive(sockfd);
1026
1027                 if (bind(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
1028                         logerror("Could not bind to %s: %s",
1029                                  ip2str(ai->ai_family, ai->ai_addr, ai->ai_addrlen),
1030                                  strerror(errno));
1031                         close(sockfd);
1032                         continue;       /* not fatal */
1033                 }
1034                 if (listen(sockfd, 5) < 0) {
1035                         logerror("Could not listen to %s: %s",
1036                                  ip2str(ai->ai_family, ai->ai_addr, ai->ai_addrlen),
1037                                  strerror(errno));
1038                         close(sockfd);
1039                         continue;       /* not fatal */
1040                 }
1041
1042                 flags = fcntl(sockfd, F_GETFD, 0);
1043                 if (flags >= 0)
1044                         fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
1045
1046                 ALLOC_GROW(socklist->list, socklist->nr + 1, socklist->alloc);
1047                 socklist->list[socklist->nr++] = sockfd;
1048                 socknum++;
1049         }
1050
1051         freeaddrinfo(ai0);
1052
1053         return socknum;
1054 }
1055
1056 #else /* NO_IPV6 */
1057
1058 static int setup_named_sock(char *listen_addr, int listen_port, struct socketlist *socklist)
1059 {
1060         struct sockaddr_in sin;
1061         int sockfd;
1062         long flags;
1063
1064         memset(&sin, 0, sizeof sin);
1065         sin.sin_family = AF_INET;
1066         sin.sin_port = htons(listen_port);
1067
1068         if (listen_addr) {
1069                 /* Well, host better be an IP address here. */
1070                 if (inet_pton(AF_INET, listen_addr, &sin.sin_addr.s_addr) <= 0)
1071                         return 0;
1072         } else {
1073                 sin.sin_addr.s_addr = htonl(INADDR_ANY);
1074         }
1075
1076         sockfd = socket(AF_INET, SOCK_STREAM, 0);
1077         if (sockfd < 0)
1078                 return 0;
1079
1080         if (set_reuse_addr(sockfd)) {
1081                 logerror("Could not set SO_REUSEADDR: %s", strerror(errno));
1082                 close(sockfd);
1083                 return 0;
1084         }
1085
1086         set_keep_alive(sockfd);
1087
1088         if ( bind(sockfd, (struct sockaddr *)&sin, sizeof sin) < 0 ) {
1089                 logerror("Could not bind to %s: %s",
1090                          ip2str(AF_INET, (struct sockaddr *)&sin, sizeof(sin)),
1091                          strerror(errno));
1092                 close(sockfd);
1093                 return 0;
1094         }
1095
1096         if (listen(sockfd, 5) < 0) {
1097                 logerror("Could not listen to %s: %s",
1098                          ip2str(AF_INET, (struct sockaddr *)&sin, sizeof(sin)),
1099                          strerror(errno));
1100                 close(sockfd);
1101                 return 0;
1102         }
1103
1104         flags = fcntl(sockfd, F_GETFD, 0);
1105         if (flags >= 0)
1106                 fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
1107
1108         ALLOC_GROW(socklist->list, socklist->nr + 1, socklist->alloc);
1109         socklist->list[socklist->nr++] = sockfd;
1110         return 1;
1111 }
1112
1113 #endif
1114
1115 static void socksetup(struct string_list *listen_addr, int listen_port, struct socketlist *socklist)
1116 {
1117         if (!listen_addr->nr)
1118                 setup_named_sock(NULL, listen_port, socklist);
1119         else {
1120                 int i, socknum;
1121                 for (i = 0; i < listen_addr->nr; i++) {
1122                         socknum = setup_named_sock(listen_addr->items[i].string,
1123                                                    listen_port, socklist);
1124
1125                         if (socknum == 0)
1126                                 logerror("unable to allocate any listen sockets for host %s on port %u",
1127                                          listen_addr->items[i].string, listen_port);
1128                 }
1129         }
1130 }
1131
1132 static int service_loop(struct socketlist *socklist)
1133 {
1134         struct pollfd *pfd;
1135         int i;
1136
1137         pfd = xcalloc(socklist->nr, sizeof(struct pollfd));
1138
1139         for (i = 0; i < socklist->nr; i++) {
1140                 pfd[i].fd = socklist->list[i];
1141                 pfd[i].events = POLLIN;
1142         }
1143
1144         signal(SIGCHLD, child_handler);
1145
1146         for (;;) {
1147                 int i;
1148
1149                 check_dead_children();
1150
1151                 if (poll(pfd, socklist->nr, -1) < 0) {
1152                         if (errno != EINTR) {
1153                                 logerror("Poll failed, resuming: %s",
1154                                       strerror(errno));
1155                                 sleep(1);
1156                         }
1157                         continue;
1158                 }
1159
1160                 for (i = 0; i < socklist->nr; i++) {
1161                         if (pfd[i].revents & POLLIN) {
1162                                 union {
1163                                         struct sockaddr sa;
1164                                         struct sockaddr_in sai;
1165 #ifndef NO_IPV6
1166                                         struct sockaddr_in6 sai6;
1167 #endif
1168                                 } ss;
1169                                 socklen_t sslen = sizeof(ss);
1170                                 int incoming = accept(pfd[i].fd, &ss.sa, &sslen);
1171                                 if (incoming < 0) {
1172                                         switch (errno) {
1173                                         case EAGAIN:
1174                                         case EINTR:
1175                                         case ECONNABORTED:
1176                                                 continue;
1177                                         default:
1178                                                 die_errno("accept returned");
1179                                         }
1180                                 }
1181                                 handle(incoming, &ss.sa, sslen);
1182                         }
1183                 }
1184         }
1185 }
1186
1187 #ifdef NO_POSIX_GOODIES
1188
1189 struct credentials;
1190
1191 static void drop_privileges(struct credentials *cred)
1192 {
1193         /* nothing */
1194 }
1195
1196 static struct credentials *prepare_credentials(const char *user_name,
1197     const char *group_name)
1198 {
1199         die("--user not supported on this platform");
1200 }
1201
1202 #else
1203
1204 struct credentials {
1205         struct passwd *pass;
1206         gid_t gid;
1207 };
1208
1209 static void drop_privileges(struct credentials *cred)
1210 {
1211         if (cred && (initgroups(cred->pass->pw_name, cred->gid) ||
1212             setgid (cred->gid) || setuid(cred->pass->pw_uid)))
1213                 die("cannot drop privileges");
1214 }
1215
1216 static struct credentials *prepare_credentials(const char *user_name,
1217     const char *group_name)
1218 {
1219         static struct credentials c;
1220
1221         c.pass = getpwnam(user_name);
1222         if (!c.pass)
1223                 die("user not found - %s", user_name);
1224
1225         if (!group_name)
1226                 c.gid = c.pass->pw_gid;
1227         else {
1228                 struct group *group = getgrnam(group_name);
1229                 if (!group)
1230                         die("group not found - %s", group_name);
1231
1232                 c.gid = group->gr_gid;
1233         }
1234
1235         return &c;
1236 }
1237 #endif
1238
1239 static int serve(struct string_list *listen_addr, int listen_port,
1240     struct credentials *cred)
1241 {
1242         struct socketlist socklist = { NULL, 0, 0 };
1243
1244         socksetup(listen_addr, listen_port, &socklist);
1245         if (socklist.nr == 0)
1246                 die("unable to allocate any listen sockets on port %u",
1247                     listen_port);
1248
1249         drop_privileges(cred);
1250
1251         loginfo("Ready to rumble");
1252
1253         return service_loop(&socklist);
1254 }
1255
1256 int cmd_main(int argc, const char **argv)
1257 {
1258         int listen_port = 0;
1259         struct string_list listen_addr = STRING_LIST_INIT_NODUP;
1260         int serve_mode = 0, inetd_mode = 0;
1261         const char *pid_file = NULL, *user_name = NULL, *group_name = NULL;
1262         int detach = 0;
1263         struct credentials *cred = NULL;
1264         int i;
1265
1266         for (i = 1; i < argc; i++) {
1267                 const char *arg = argv[i];
1268                 const char *v;
1269
1270                 if (skip_prefix(arg, "--listen=", &v)) {
1271                         string_list_append(&listen_addr, xstrdup_tolower(v));
1272                         continue;
1273                 }
1274                 if (skip_prefix(arg, "--port=", &v)) {
1275                         char *end;
1276                         unsigned long n;
1277                         n = strtoul(v, &end, 0);
1278                         if (*v && !*end) {
1279                                 listen_port = n;
1280                                 continue;
1281                         }
1282                 }
1283                 if (!strcmp(arg, "--serve")) {
1284                         serve_mode = 1;
1285                         continue;
1286                 }
1287                 if (!strcmp(arg, "--inetd")) {
1288                         inetd_mode = 1;
1289                         log_syslog = 1;
1290                         continue;
1291                 }
1292                 if (!strcmp(arg, "--verbose")) {
1293                         verbose = 1;
1294                         continue;
1295                 }
1296                 if (!strcmp(arg, "--syslog")) {
1297                         log_syslog = 1;
1298                         continue;
1299                 }
1300                 if (!strcmp(arg, "--export-all")) {
1301                         export_all_trees = 1;
1302                         continue;
1303                 }
1304                 if (skip_prefix(arg, "--access-hook=", &v)) {
1305                         access_hook = v;
1306                         continue;
1307                 }
1308                 if (skip_prefix(arg, "--timeout=", &v)) {
1309                         timeout = atoi(v);
1310                         continue;
1311                 }
1312                 if (skip_prefix(arg, "--init-timeout=", &v)) {
1313                         init_timeout = atoi(v);
1314                         continue;
1315                 }
1316                 if (skip_prefix(arg, "--max-connections=", &v)) {
1317                         max_connections = atoi(v);
1318                         if (max_connections < 0)
1319                                 max_connections = 0;            /* unlimited */
1320                         continue;
1321                 }
1322                 if (!strcmp(arg, "--strict-paths")) {
1323                         strict_paths = 1;
1324                         continue;
1325                 }
1326                 if (skip_prefix(arg, "--base-path=", &v)) {
1327                         base_path = v;
1328                         continue;
1329                 }
1330                 if (!strcmp(arg, "--base-path-relaxed")) {
1331                         base_path_relaxed = 1;
1332                         continue;
1333                 }
1334                 if (skip_prefix(arg, "--interpolated-path=", &v)) {
1335                         interpolated_path = v;
1336                         continue;
1337                 }
1338                 if (!strcmp(arg, "--reuseaddr")) {
1339                         reuseaddr = 1;
1340                         continue;
1341                 }
1342                 if (!strcmp(arg, "--user-path")) {
1343                         user_path = "";
1344                         continue;
1345                 }
1346                 if (skip_prefix(arg, "--user-path=", &v)) {
1347                         user_path = v;
1348                         continue;
1349                 }
1350                 if (skip_prefix(arg, "--pid-file=", &v)) {
1351                         pid_file = v;
1352                         continue;
1353                 }
1354                 if (!strcmp(arg, "--detach")) {
1355                         detach = 1;
1356                         log_syslog = 1;
1357                         continue;
1358                 }
1359                 if (skip_prefix(arg, "--user=", &v)) {
1360                         user_name = v;
1361                         continue;
1362                 }
1363                 if (skip_prefix(arg, "--group=", &v)) {
1364                         group_name = v;
1365                         continue;
1366                 }
1367                 if (skip_prefix(arg, "--enable=", &v)) {
1368                         enable_service(v, 1);
1369                         continue;
1370                 }
1371                 if (skip_prefix(arg, "--disable=", &v)) {
1372                         enable_service(v, 0);
1373                         continue;
1374                 }
1375                 if (skip_prefix(arg, "--allow-override=", &v)) {
1376                         make_service_overridable(v, 1);
1377                         continue;
1378                 }
1379                 if (skip_prefix(arg, "--forbid-override=", &v)) {
1380                         make_service_overridable(v, 0);
1381                         continue;
1382                 }
1383                 if (!strcmp(arg, "--informative-errors")) {
1384                         informative_errors = 1;
1385                         continue;
1386                 }
1387                 if (!strcmp(arg, "--no-informative-errors")) {
1388                         informative_errors = 0;
1389                         continue;
1390                 }
1391                 if (!strcmp(arg, "--")) {
1392                         ok_paths = &argv[i+1];
1393                         break;
1394                 } else if (arg[0] != '-') {
1395                         ok_paths = &argv[i];
1396                         break;
1397                 }
1398
1399                 usage(daemon_usage);
1400         }
1401
1402         if (log_syslog) {
1403                 openlog("git-daemon", LOG_PID, LOG_DAEMON);
1404                 set_die_routine(daemon_die);
1405         } else
1406                 /* avoid splitting a message in the middle */
1407                 setvbuf(stderr, NULL, _IOFBF, 4096);
1408
1409         if (inetd_mode && (detach || group_name || user_name))
1410                 die("--detach, --user and --group are incompatible with --inetd");
1411
1412         if (inetd_mode && (listen_port || (listen_addr.nr > 0)))
1413                 die("--listen= and --port= are incompatible with --inetd");
1414         else if (listen_port == 0)
1415                 listen_port = DEFAULT_GIT_PORT;
1416
1417         if (group_name && !user_name)
1418                 die("--group supplied without --user");
1419
1420         if (user_name)
1421                 cred = prepare_credentials(user_name, group_name);
1422
1423         if (strict_paths && (!ok_paths || !*ok_paths))
1424                 die("option --strict-paths requires a whitelist");
1425
1426         if (base_path && !is_directory(base_path))
1427                 die("base-path '%s' does not exist or is not a directory",
1428                     base_path);
1429
1430         if (inetd_mode) {
1431                 if (!freopen("/dev/null", "w", stderr))
1432                         die_errno("failed to redirect stderr to /dev/null");
1433         }
1434
1435         if (inetd_mode || serve_mode)
1436                 return execute();
1437
1438         if (detach) {
1439                 if (daemonize())
1440                         die("--detach not supported on this platform");
1441         }
1442
1443         if (pid_file)
1444                 write_file(pid_file, "%"PRIuMAX, (uintmax_t) getpid());
1445
1446         /* prepare argv for serving-processes */
1447         argv_array_push(&cld_argv, argv[0]); /* git-daemon */
1448         argv_array_push(&cld_argv, "--serve");
1449         for (i = 1; i < argc; ++i)
1450                 argv_array_push(&cld_argv, argv[i]);
1451
1452         return serve(&listen_addr, listen_port, cred);
1453 }