daemon.c

   1 #include "cache.h"
   2 #include "abspath.h"
   3 #include "alloc.h"
   4 #include "config.h"
   5 #include "environment.h"
   6 #include "pkt-line.h"
   7 #include "run-command.h"
   8 #include "setup.h"
   9 #include "strbuf.h"
  10 #include "string-list.h"
  11 #include "wrapper.h"
  12
  13 #ifdef NO_INITGROUPS
  14 #define initgroups(x, y) (0) /* nothing */
  15 #endif
  16
  17 static enum log_destination {
  18         LOG_DESTINATION_UNSET = -1,
  19         LOG_DESTINATION_NONE = 0,
  20         LOG_DESTINATION_STDERR = 1,
  21         LOG_DESTINATION_SYSLOG = 2,
  22 } log_destination = LOG_DESTINATION_UNSET;
  23 static int verbose;
  24 static int reuseaddr;
  25 static int informative_errors;
  26
  27 static const char daemon_usage[] =
  28 "git daemon [--verbose] [--syslog] [--export-all]\n"
  29 "           [--timeout=<n>] [--init-timeout=<n>] [--max-connections=<n>]\n"
  30 "           [--strict-paths] [--base-path=<path>] [--base-path-relaxed]\n"
  31 "           [--user-path | --user-path=<path>]\n"
  32 "           [--interpolated-path=<path>]\n"
  33 "           [--reuseaddr] [--pid-file=<file>]\n"
  34 "           [--(enable|disable|allow-override|forbid-override)=<service>]\n"
  35 "           [--access-hook=<path>]\n"
  36 "           [--inetd | [--listen=<host_or_ipaddr>] [--port=<n>]\n"
  37 "                      [--detach] [--user=<user> [--group=<group>]]\n"
  38 "           [--log-destination=(stderr|syslog|none)]\n"
  39 "           [<directory>...]";
  40
  41 /* List of acceptable pathname prefixes */
  42 static const char **ok_paths;
  43 static int strict_paths;
  44
  45 /* If this is set, git-daemon-export-ok is not required */
  46 static int export_all_trees;
  47
  48 /* Take all paths relative to this one if non-NULL */
  49 static const char *base_path;
  50 static const char *interpolated_path;
  51 static int base_path_relaxed;
  52
  53 /* If defined, ~user notation is allowed and the string is inserted
  54  * after ~user/.  E.g. a request to git://host/~alice/frotz would
  55  * go to /home/alice/pub_git/frotz with --user-path=pub_git.
  56  */
  57 static const char *user_path;
  58
  59 /* Timeout, and initial timeout */
  60 static unsigned int timeout;
  61 static unsigned int init_timeout;
  62
  63 struct hostinfo {
  64         struct strbuf hostname;
  65         struct strbuf canon_hostname;
  66         struct strbuf ip_address;
  67         struct strbuf tcp_port;
  68         unsigned int hostname_lookup_done:1;
  69         unsigned int saw_extended_args:1;
  70 };
  71 #define HOSTINFO_INIT { \
  72         .hostname = STRBUF_INIT, \
  73         .canon_hostname = STRBUF_INIT, \
  74         .ip_address = STRBUF_INIT, \
  75         .tcp_port = STRBUF_INIT, \
  76 }
  77
  78 static void lookup_hostname(struct hostinfo *hi);
  79
  80 static const char *get_canon_hostname(struct hostinfo *hi)
  81 {
  82         lookup_hostname(hi);
  83         return hi->canon_hostname.buf;
  84 }
  85
  86 static const char *get_ip_address(struct hostinfo *hi)
  87 {
  88         lookup_hostname(hi);
  89         return hi->ip_address.buf;
  90 }
  91
  92 static void logreport(int priority, const char *err, va_list params)
  93 {
  94         switch (log_destination) {
  95         case LOG_DESTINATION_SYSLOG: {
  96                 char buf[1024];
  97                 vsnprintf(buf, sizeof(buf), err, params);
  98                 syslog(priority, "%s", buf);
  99                 break;
 100         }
 101         case LOG_DESTINATION_STDERR:
 102                 /*
 103                  * Since stderr is set to buffered mode, the
 104                  * logging of different processes will not overlap
 105                  * unless they overflow the (rather big) buffers.
 106                  */
 107                 fprintf(stderr, "[%"PRIuMAX"] ", (uintmax_t)getpid());
 108                 vfprintf(stderr, err, params);
 109                 fputc('\n', stderr);
 110                 fflush(stderr);
 111                 break;
 112         case LOG_DESTINATION_NONE:
 113                 break;
 114         case LOG_DESTINATION_UNSET:
 115                 BUG("log destination not initialized correctly");
 116         }
 117 }
 118
 119 __attribute__((format (printf, 1, 2)))
 120 static void logerror(const char *err, ...)
 121 {
 122         va_list params;
 123         va_start(params, err);
 124         logreport(LOG_ERR, err, params);
 125         va_end(params);
 126 }
 127
 128 __attribute__((format (printf, 1, 2)))
 129 static void loginfo(const char *err, ...)
 130 {
 131         va_list params;
 132         if (!verbose)
 133                 return;
 134         va_start(params, err);
 135         logreport(LOG_INFO, err, params);
 136         va_end(params);
 137 }
 138
 139 static void NORETURN daemon_die(const char *err, va_list params)
 140 {
 141         logreport(LOG_ERR, err, params);
 142         exit(1);
 143 }
 144
 145 struct expand_path_context {
 146         const char *directory;
 147         struct hostinfo *hostinfo;
 148 };
 149
 150 static size_t expand_path(struct strbuf *sb, const char *placeholder, void *ctx)
 151 {
 152         struct expand_path_context *context = ctx;
 153         struct hostinfo *hi = context->hostinfo;
 154
 155         switch (placeholder[0]) {
 156         case 'H':
 157                 strbuf_addbuf(sb, &hi->hostname);
 158                 return 1;
 159         case 'C':
 160                 if (placeholder[1] == 'H') {
 161                         strbuf_addstr(sb, get_canon_hostname(hi));
 162                         return 2;
 163                 }
 164                 break;
 165         case 'I':
 166                 if (placeholder[1] == 'P') {
 167                         strbuf_addstr(sb, get_ip_address(hi));
 168                         return 2;
 169                 }
 170                 break;
 171         case 'P':
 172                 strbuf_addbuf(sb, &hi->tcp_port);
 173                 return 1;
 174         case 'D':
 175                 strbuf_addstr(sb, context->directory);
 176                 return 1;
 177         }
 178         return 0;
 179 }
 180
 181 static const char *path_ok(const char *directory, struct hostinfo *hi)
 182 {
 183         static char rpath[PATH_MAX];
 184         static char interp_path[PATH_MAX];
 185         size_t rlen;
 186         const char *path;
 187         const char *dir;
 188
 189         dir = directory;
 190
 191         if (daemon_avoid_alias(dir)) {
 192                 logerror("'%s': aliased", dir);
 193                 return NULL;
 194         }
 195
 196         if (*dir == '~') {
 197                 if (!user_path) {
 198                         logerror("'%s': User-path not allowed", dir);
 199                         return NULL;
 200                 }
 201                 if (*user_path) {
 202                         /* Got either "~alice" or "~alice/foo";
 203                          * rewrite them to "~alice/%s" or
 204                          * "~alice/%s/foo".
 205                          */
 206                         int namlen, restlen = strlen(dir);
 207                         const char *slash = strchr(dir, '/');
 208                         if (!slash)
 209                                 slash = dir + restlen;
 210                         namlen = slash - dir;
 211                         restlen -= namlen;
 212                         loginfo("userpath <%s>, request <%s>, namlen %d, restlen %d, slash <%s>", user_path, dir, namlen, restlen, slash);
 213                         rlen = snprintf(rpath, sizeof(rpath), "%.*s/%s%.*s",
 214                                         namlen, dir, user_path, restlen, slash);
 215                         if (rlen >= sizeof(rpath)) {
 216                                 logerror("user-path too large: %s", rpath);
 217                                 return NULL;
 218                         }
 219                         dir = rpath;
 220                 }
 221         }
 222         else if (interpolated_path && hi->saw_extended_args) {
 223                 struct strbuf expanded_path = STRBUF_INIT;
 224                 struct expand_path_context context;
 225
 226                 context.directory = directory;
 227                 context.hostinfo = hi;
 228
 229                 if (*dir != '/') {
 230                         /* Allow only absolute */
 231                         logerror("'%s': Non-absolute path denied (interpolated-path active)", dir);
 232                         return NULL;
 233                 }
 234
 235                 strbuf_expand(&expanded_path, interpolated_path,
 236                               expand_path, &context);
 237
 238                 rlen = strlcpy(interp_path, expanded_path.buf,
 239                                sizeof(interp_path));
 240                 strbuf_release(&expanded_path);
 241                 if (rlen >= sizeof(interp_path)) {
 242                         logerror("interpolated path too large: %s",
 243                                  interp_path);
 244                         return NULL;
 245                 }
 246
 247                 loginfo("Interpolated dir '%s'", interp_path);
 248
 249                 dir = interp_path;
 250         }
 251         else if (base_path) {
 252                 if (*dir != '/') {
 253                         /* Allow only absolute */
 254                         logerror("'%s': Non-absolute path denied (base-path active)", dir);
 255                         return NULL;
 256                 }
 257                 rlen = snprintf(rpath, sizeof(rpath), "%s%s", base_path, dir);
 258                 if (rlen >= sizeof(rpath)) {
 259                         logerror("base-path too large: %s", rpath);
 260                         return NULL;
 261                 }
 262                 dir = rpath;
 263         }
 264
 265         path = enter_repo(dir, strict_paths);
 266         if (!path && base_path && base_path_relaxed) {
 267                 /*
 268                  * if we fail and base_path_relaxed is enabled, try without
 269                  * prefixing the base path
 270                  */
 271                 dir = directory;
 272                 path = enter_repo(dir, strict_paths);
 273         }
 274
 275         if (!path) {
 276                 logerror("'%s' does not appear to be a git repository", dir);
 277                 return NULL;
 278         }
 279
 280         if ( ok_paths && *ok_paths ) {
 281                 const char **pp;
 282                 int pathlen = strlen(path);
 283
 284                 /* The validation is done on the paths after enter_repo
 285                  * appends optional {.git,.git/.git} and friends, but
 286                  * it does not use getcwd().  So if your /pub is
 287                  * a symlink to /mnt/pub, you can include /pub and
 288                  * do not have to say /mnt/pub.
 289                  * Do not say /pub/.
 290                  */
 291                 for ( pp = ok_paths ; *pp ; pp++ ) {
 292                         int len = strlen(*pp);
 293                         if (len <= pathlen &&
 294                             !memcmp(*pp, path, len) &&
 295                             (path[len] == '\0' ||
 296                              (!strict_paths && path[len] == '/')))
 297                                 return path;
 298                 }
 299         }
 300         else {
 301                 /* be backwards compatible */
 302                 if (!strict_paths)
 303                         return path;
 304         }
 305
 306         logerror("'%s': not in directory list", path);
 307         return NULL;            /* Fallthrough. Deny by default */
 308 }
 309
 310 typedef int (*daemon_service_fn)(const struct strvec *env);
 311 struct daemon_service {
 312         const char *name;
 313         const char *config_name;
 314         daemon_service_fn fn;
 315         int enabled;
 316         int overridable;
 317 };
 318
 319 static int daemon_error(const char *dir, const char *msg)
 320 {
 321         if (!informative_errors)
 322                 msg = "access denied or repository not exported";
 323         packet_write_fmt(1, "ERR %s: %s", msg, dir);
 324         return -1;
 325 }
 326
 327 static const char *access_hook;
 328
 329 static int run_access_hook(struct daemon_service *service, const char *dir,
 330                            const char *path, struct hostinfo *hi)
 331 {
 332         struct child_process child = CHILD_PROCESS_INIT;
 333         struct strbuf buf = STRBUF_INIT;
 334         char *eol;
 335         int seen_errors = 0;
 336
 337         strvec_push(&child.args, access_hook);
 338         strvec_push(&child.args, service->name);
 339         strvec_push(&child.args, path);
 340         strvec_push(&child.args, hi->hostname.buf);
 341         strvec_push(&child.args, get_canon_hostname(hi));
 342         strvec_push(&child.args, get_ip_address(hi));
 343         strvec_push(&child.args, hi->tcp_port.buf);
 344
 345         child.use_shell = 1;
 346         child.no_stdin = 1;
 347         child.no_stderr = 1;
 348         child.out = -1;
 349         if (start_command(&child)) {
 350                 logerror("daemon access hook '%s' failed to start",
 351                          access_hook);
 352                 goto error_return;
 353         }
 354         if (strbuf_read(&buf, child.out, 0) < 0) {
 355                 logerror("failed to read from pipe to daemon access hook '%s'",
 356                          access_hook);
 357                 strbuf_reset(&buf);
 358                 seen_errors = 1;
 359         }
 360         if (close(child.out) < 0) {
 361                 logerror("failed to close pipe to daemon access hook '%s'",
 362                          access_hook);
 363                 seen_errors = 1;
 364         }
 365         if (finish_command(&child))
 366                 seen_errors = 1;
 367
 368         if (!seen_errors) {
 369                 strbuf_release(&buf);
 370                 return 0;
 371         }
 372
 373 error_return:
 374         strbuf_ltrim(&buf);
 375         if (!buf.len)
 376                 strbuf_addstr(&buf, "service rejected");
 377         eol = strchr(buf.buf, '\n');
 378         if (eol)
 379                 *eol = '\0';
 380         errno = EACCES;
 381         daemon_error(dir, buf.buf);
 382         strbuf_release(&buf);
 383         return -1;
 384 }
 385
 386 static int run_service(const char *dir, struct daemon_service *service,
 387                        struct hostinfo *hi, const struct strvec *env)
 388 {
 389         const char *path;
 390         int enabled = service->enabled;
 391         struct strbuf var = STRBUF_INIT;
 392
 393         loginfo("Request %s for '%s'", service->name, dir);
 394
 395         if (!enabled && !service->overridable) {
 396                 logerror("'%s': service not enabled.", service->name);
 397                 errno = EACCES;
 398                 return daemon_error(dir, "service not enabled");
 399         }
 400
 401         if (!(path = path_ok(dir, hi)))
 402                 return daemon_error(dir, "no such repository");
 403
 404         /*
 405          * Security on the cheap.
 406          *
 407          * We want a readable HEAD, usable "objects" directory, and
 408          * a "git-daemon-export-ok" flag that says that the other side
 409          * is ok with us doing this.
 410          *
 411          * path_ok() uses enter_repo() and checks for included directories.
 412          * We only need to make sure the repository is exported.
 413          */
 414
 415         if (!export_all_trees && access("git-daemon-export-ok", F_OK)) {
 416                 logerror("'%s': repository not exported.", path);
 417                 errno = EACCES;
 418                 return daemon_error(dir, "repository not exported");
 419         }
 420
 421         if (service->overridable) {
 422                 strbuf_addf(&var, "daemon.%s", service->config_name);
 423                 git_config_get_bool(var.buf, &enabled);
 424                 strbuf_release(&var);
 425         }
 426         if (!enabled) {
 427                 logerror("'%s': service not enabled for '%s'",
 428                          service->name, path);
 429                 errno = EACCES;
 430                 return daemon_error(dir, "service not enabled");
 431         }
 432
 433         /*
 434          * Optionally, a hook can choose to deny access to the
 435          * repository depending on the phase of the moon.
 436          */
 437         if (access_hook && run_access_hook(service, dir, path, hi))
 438                 return -1;
 439
 440         /*
 441          * We'll ignore SIGTERM from now on, we have a
 442          * good client.
 443          */
 444         signal(SIGTERM, SIG_IGN);
 445
 446         return service->fn(env);
 447 }
 448
 449 static void copy_to_log(int fd)
 450 {
 451         struct strbuf line = STRBUF_INIT;
 452         FILE *fp;
 453
 454         fp = fdopen(fd, "r");
 455         if (!fp) {
 456                 logerror("fdopen of error channel failed");
 457                 close(fd);
 458                 return;
 459         }
 460
 461         while (strbuf_getline_lf(&line, fp) != EOF) {
 462                 logerror("%s", line.buf);
 463                 strbuf_setlen(&line, 0);
 464         }
 465
 466         strbuf_release(&line);
 467         fclose(fp);
 468 }
 469
 470 static int run_service_command(struct child_process *cld)
 471 {
 472         strvec_push(&cld->args, ".");
 473         cld->git_cmd = 1;
 474         cld->err = -1;
 475         if (start_command(cld))
 476                 return -1;
 477
 478         close(0);
 479         close(1);
 480
 481         copy_to_log(cld->err);
 482
 483         return finish_command(cld);
 484 }
 485
 486 static int upload_pack(const struct strvec *env)
 487 {
 488         struct child_process cld = CHILD_PROCESS_INIT;
 489         strvec_pushl(&cld.args, "upload-pack", "--strict", NULL);
 490         strvec_pushf(&cld.args, "--timeout=%u", timeout);
 491
 492         strvec_pushv(&cld.env, env->v);
 493
 494         return run_service_command(&cld);
 495 }
 496
 497 static int upload_archive(const struct strvec *env)
 498 {
 499         struct child_process cld = CHILD_PROCESS_INIT;
 500         strvec_push(&cld.args, "upload-archive");
 501
 502         strvec_pushv(&cld.env, env->v);
 503
 504         return run_service_command(&cld);
 505 }
 506
 507 static int receive_pack(const struct strvec *env)
 508 {
 509         struct child_process cld = CHILD_PROCESS_INIT;
 510         strvec_push(&cld.args, "receive-pack");
 511
 512         strvec_pushv(&cld.env, env->v);
 513
 514         return run_service_command(&cld);
 515 }
 516
 517 static struct daemon_service daemon_service[] = {
 518         { "upload-archive", "uploadarch", upload_archive, 0, 1 },
 519         { "upload-pack", "uploadpack", upload_pack, 1, 1 },
 520         { "receive-pack", "receivepack", receive_pack, 0, 1 },
 521 };
 522
 523 static void enable_service(const char *name, int ena)
 524 {
 525         int i;
 526         for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
 527                 if (!strcmp(daemon_service[i].name, name)) {
 528                         daemon_service[i].enabled = ena;
 529                         return;
 530                 }
 531         }
 532         die("No such service %s", name);
 533 }
 534
 535 static void make_service_overridable(const char *name, int ena)
 536 {
 537         int i;
 538         for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
 539                 if (!strcmp(daemon_service[i].name, name)) {
 540                         daemon_service[i].overridable = ena;
 541                         return;
 542                 }
 543         }
 544         die("No such service %s", name);
 545 }
 546
 547 static void parse_host_and_port(char *hostport, char **host,
 548         char **port)
 549 {
 550         if (*hostport == '[') {
 551                 char *end;
 552
 553                 end = strchr(hostport, ']');
 554                 if (!end)
 555                         die("Invalid request ('[' without ']')");
 556                 *end = '\0';
 557                 *host = hostport + 1;
 558                 if (!end[1])
 559                         *port = NULL;
 560                 else if (end[1] == ':')
 561                         *port = end + 2;
 562                 else
 563                         die("Garbage after end of host part");
 564         } else {
 565                 *host = hostport;
 566                 *port = strrchr(hostport, ':');
 567                 if (*port) {
 568                         **port = '\0';
 569                         ++*port;
 570                 }
 571         }
 572 }
 573
 574 /*
 575  * Sanitize a string from the client so that it's OK to be inserted into a
 576  * filesystem path. Specifically, we disallow directory separators, runs
 577  * of "..", and trailing and leading dots, which means that the client
 578  * cannot escape our base path via ".." traversal.
 579  */
 580 static void sanitize_client(struct strbuf *out, const char *in)
 581 {
 582         for (; *in; in++) {
 583                 if (is_dir_sep(*in))
 584                         continue;
 585                 if (*in == '.' && (!out->len || out->buf[out->len - 1] == '.'))
 586                         continue;
 587                 strbuf_addch(out, *in);
 588         }
 589
 590         while (out->len && out->buf[out->len - 1] == '.')
 591                 strbuf_setlen(out, out->len - 1);
 592 }
 593
 594 /*
 595  * Like sanitize_client, but we also perform any canonicalization
 596  * to make life easier on the admin.
 597  */
 598 static void canonicalize_client(struct strbuf *out, const char *in)
 599 {
 600         sanitize_client(out, in);
 601         strbuf_tolower(out);
 602 }
 603
 604 /*
 605  * Read the host as supplied by the client connection.
 606  *
 607  * Returns a pointer to the character after the NUL byte terminating the host
 608  * argument, or 'extra_args' if there is no host argument.
 609  */
 610 static char *parse_host_arg(struct hostinfo *hi, char *extra_args, int buflen)
 611 {
 612         char *val;
 613         int vallen;
 614         char *end = extra_args + buflen;
 615
 616         if (extra_args < end && *extra_args) {
 617                 hi->saw_extended_args = 1;
 618                 if (strncasecmp("host=", extra_args, 5) == 0) {
 619                         val = extra_args + 5;
 620                         vallen = strlen(val) + 1;
 621                         loginfo("Extended attribute \"host\": %s", val);
 622                         if (*val) {
 623                                 /* Split <host>:<port> at colon. */
 624                                 char *host;
 625                                 char *port;
 626                                 parse_host_and_port(val, &host, &port);
 627                                 if (port)
 628                                         sanitize_client(&hi->tcp_port, port);
 629                                 canonicalize_client(&hi->hostname, host);
 630                                 hi->hostname_lookup_done = 0;
 631                         }
 632
 633                         /* On to the next one */
 634                         extra_args = val + vallen;
 635                 }
 636                 if (extra_args < end && *extra_args)
 637                         die("Invalid request");
 638         }
 639
 640         return extra_args;
 641 }
 642
 643 static void parse_extra_args(struct hostinfo *hi, struct strvec *env,
 644                              char *extra_args, int buflen)
 645 {
 646         const char *end = extra_args + buflen;
 647         struct strbuf git_protocol = STRBUF_INIT;
 648
 649         /* First look for the host argument */
 650         extra_args = parse_host_arg(hi, extra_args, buflen);
 651
 652         /* Look for additional arguments places after a second NUL byte */
 653         for (; extra_args < end; extra_args += strlen(extra_args) + 1) {
 654                 const char *arg = extra_args;
 655
 656                 /*
 657                  * Parse the extra arguments, adding most to 'git_protocol'
 658                  * which will be used to set the 'GIT_PROTOCOL' envvar in the
 659                  * service that will be run.
 660                  *
 661                  * If there ends up being a particular arg in the future that
 662                  * git-daemon needs to parse specifically (like the 'host' arg)
 663                  * then it can be parsed here and not added to 'git_protocol'.
 664                  */
 665                 if (*arg) {
 666                         if (git_protocol.len > 0)
 667                                 strbuf_addch(&git_protocol, ':');
 668                         strbuf_addstr(&git_protocol, arg);
 669                 }
 670         }
 671
 672         if (git_protocol.len > 0) {
 673                 loginfo("Extended attribute \"protocol\": %s", git_protocol.buf);
 674                 strvec_pushf(env, GIT_PROTOCOL_ENVIRONMENT "=%s",
 675                              git_protocol.buf);
 676         }
 677         strbuf_release(&git_protocol);
 678 }
 679
 680 /*
 681  * Locate canonical hostname and its IP address.
 682  */
 683 static void lookup_hostname(struct hostinfo *hi)
 684 {
 685         if (!hi->hostname_lookup_done && hi->hostname.len) {
 686 #ifndef NO_IPV6
 687                 struct addrinfo hints;
 688                 struct addrinfo *ai;
 689                 int gai;
 690                 static char addrbuf[HOST_NAME_MAX + 1];
 691
 692                 memset(&hints, 0, sizeof(hints));
 693                 hints.ai_flags = AI_CANONNAME;
 694
 695                 gai = getaddrinfo(hi->hostname.buf, NULL, &hints, &ai);
 696                 if (!gai) {
 697                         struct sockaddr_in *sin_addr = (void *)ai->ai_addr;
 698
 699                         inet_ntop(AF_INET, &sin_addr->sin_addr,
 700                                   addrbuf, sizeof(addrbuf));
 701                         strbuf_addstr(&hi->ip_address, addrbuf);
 702
 703                         if (ai->ai_canonname)
 704                                 sanitize_client(&hi->canon_hostname,
 705                                                 ai->ai_canonname);
 706                         else
 707                                 strbuf_addbuf(&hi->canon_hostname,
 708                                               &hi->ip_address);
 709
 710                         freeaddrinfo(ai);
 711                 }
 712 #else
 713                 struct hostent *hent;
 714                 struct sockaddr_in sa;
 715                 char **ap;
 716                 static char addrbuf[HOST_NAME_MAX + 1];
 717
 718                 hent = gethostbyname(hi->hostname.buf);
 719                 if (hent) {
 720                         ap = hent->h_addr_list;
 721                         memset(&sa, 0, sizeof sa);
 722                         sa.sin_family = hent->h_addrtype;
 723                         sa.sin_port = htons(0);
 724                         memcpy(&sa.sin_addr, *ap, hent->h_length);
 725
 726                         inet_ntop(hent->h_addrtype, &sa.sin_addr,
 727                                   addrbuf, sizeof(addrbuf));
 728
 729                         sanitize_client(&hi->canon_hostname, hent->h_name);
 730                         strbuf_addstr(&hi->ip_address, addrbuf);
 731                 }
 732 #endif
 733                 hi->hostname_lookup_done = 1;
 734         }
 735 }
 736
 737 static void hostinfo_clear(struct hostinfo *hi)
 738 {
 739         strbuf_release(&hi->hostname);
 740         strbuf_release(&hi->canon_hostname);
 741         strbuf_release(&hi->ip_address);
 742         strbuf_release(&hi->tcp_port);
 743 }
 744
 745 static void set_keep_alive(int sockfd)
 746 {
 747         int ka = 1;
 748
 749         if (setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, &ka, sizeof(ka)) < 0) {
 750                 if (errno != ENOTSOCK)
 751                         logerror("unable to set SO_KEEPALIVE on socket: %s",
 752                                 strerror(errno));
 753         }
 754 }
 755
 756 static int execute(void)
 757 {
 758         char *line = packet_buffer;
 759         int pktlen, len, i;
 760         char *addr = getenv("REMOTE_ADDR"), *port = getenv("REMOTE_PORT");
 761         struct hostinfo hi = HOSTINFO_INIT;
 762         struct strvec env = STRVEC_INIT;
 763
 764         if (addr)
 765                 loginfo("Connection from %s:%s", addr, port);
 766
 767         set_keep_alive(0);
 768         alarm(init_timeout ? init_timeout : timeout);
 769         pktlen = packet_read(0, packet_buffer, sizeof(packet_buffer), 0);
 770         alarm(0);
 771
 772         len = strlen(line);
 773         if (len && line[len-1] == '\n')
 774                 line[len-1] = 0;
 775
 776         /* parse additional args hidden behind a NUL byte */
 777         if (len != pktlen)
 778                 parse_extra_args(&hi, &env, line + len + 1, pktlen - len - 1);
 779
 780         for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
 781                 struct daemon_service *s = &(daemon_service[i]);
 782                 const char *arg;
 783
 784                 if (skip_prefix(line, "git-", &arg) &&
 785                     skip_prefix(arg, s->name, &arg) &&
 786                     *arg++ == ' ') {
 787                         /*
 788                          * Note: The directory here is probably context sensitive,
 789                          * and might depend on the actual service being performed.
 790                          */
 791                         int rc = run_service(arg, s, &hi, &env);
 792                         hostinfo_clear(&hi);
 793                         strvec_clear(&env);
 794                         return rc;
 795                 }
 796         }
 797
 798         hostinfo_clear(&hi);
 799         strvec_clear(&env);
 800         logerror("Protocol error: '%s'", line);
 801         return -1;
 802 }
 803
 804 static int addrcmp(const struct sockaddr_storage *s1,
 805     const struct sockaddr_storage *s2)
 806 {
 807         const struct sockaddr *sa1 = (const struct sockaddr*) s1;
 808         const struct sockaddr *sa2 = (const struct sockaddr*) s2;
 809
 810         if (sa1->sa_family != sa2->sa_family)
 811                 return sa1->sa_family - sa2->sa_family;
 812         if (sa1->sa_family == AF_INET)
 813                 return memcmp(&((struct sockaddr_in *)s1)->sin_addr,
 814                     &((struct sockaddr_in *)s2)->sin_addr,
 815                     sizeof(struct in_addr));
 816 #ifndef NO_IPV6
 817         if (sa1->sa_family == AF_INET6)
 818                 return memcmp(&((struct sockaddr_in6 *)s1)->sin6_addr,
 819                     &((struct sockaddr_in6 *)s2)->sin6_addr,
 820                     sizeof(struct in6_addr));
 821 #endif
 822         return 0;
 823 }
 824
 825 static int max_connections = 32;
 826
 827 static unsigned int live_children;
 828
 829 static struct child {
 830         struct child *next;
 831         struct child_process cld;
 832         struct sockaddr_storage address;
 833 } *firstborn;
 834
 835 static void add_child(struct child_process *cld, struct sockaddr *addr, socklen_t addrlen)
 836 {
 837         struct child *newborn, **cradle;
 838
 839         CALLOC_ARRAY(newborn, 1);
 840         live_children++;
 841         memcpy(&newborn->cld, cld, sizeof(*cld));
 842         memcpy(&newborn->address, addr, addrlen);
 843         for (cradle = &firstborn; *cradle; cradle = &(*cradle)->next)
 844                 if (!addrcmp(&(*cradle)->address, &newborn->address))
 845                         break;
 846         newborn->next = *cradle;
 847         *cradle = newborn;
 848 }
 849
 850 /*
 851  * This gets called if the number of connections grows
 852  * past "max_connections".
 853  *
 854  * We kill the newest connection from a duplicate IP.
 855  */
 856 static void kill_some_child(void)
 857 {
 858         const struct child *blanket, *next;
 859
 860         if (!(blanket = firstborn))
 861                 return;
 862
 863         for (; (next = blanket->next); blanket = next)
 864                 if (!addrcmp(&blanket->address, &next->address)) {
 865                         kill(blanket->cld.pid, SIGTERM);
 866                         break;
 867                 }
 868 }
 869
 870 static void check_dead_children(void)
 871 {
 872         int status;
 873         pid_t pid;
 874
 875         struct child **cradle, *blanket;
 876         for (cradle = &firstborn; (blanket = *cradle);)
 877                 if ((pid = waitpid(blanket->cld.pid, &status, WNOHANG)) > 1) {
 878                         const char *dead = "";
 879                         if (status)
 880                                 dead = " (with error)";
 881                         loginfo("[%"PRIuMAX"] Disconnected%s", (uintmax_t)pid, dead);
 882
 883                         /* remove the child */
 884                         *cradle = blanket->next;
 885                         live_children--;
 886                         child_process_clear(&blanket->cld);
 887                         free(blanket);
 888                 } else
 889                         cradle = &blanket->next;
 890 }
 891
 892 static struct strvec cld_argv = STRVEC_INIT;
 893 static void handle(int incoming, struct sockaddr *addr, socklen_t addrlen)
 894 {
 895         struct child_process cld = CHILD_PROCESS_INIT;
 896
 897         if (max_connections && live_children >= max_connections) {
 898                 kill_some_child();
 899                 sleep(1);  /* give it some time to die */
 900                 check_dead_children();
 901                 if (live_children >= max_connections) {
 902                         close(incoming);
 903                         logerror("Too many children, dropping connection");
 904                         return;
 905                 }
 906         }
 907
 908         if (addr->sa_family == AF_INET) {
 909                 char buf[128] = "";
 910                 struct sockaddr_in *sin_addr = (void *) addr;
 911                 inet_ntop(addr->sa_family, &sin_addr->sin_addr, buf, sizeof(buf));
 912                 strvec_pushf(&cld.env, "REMOTE_ADDR=%s", buf);
 913                 strvec_pushf(&cld.env, "REMOTE_PORT=%d",
 914                              ntohs(sin_addr->sin_port));
 915 #ifndef NO_IPV6
 916         } else if (addr->sa_family == AF_INET6) {
 917                 char buf[128] = "";
 918                 struct sockaddr_in6 *sin6_addr = (void *) addr;
 919                 inet_ntop(AF_INET6, &sin6_addr->sin6_addr, buf, sizeof(buf));
 920                 strvec_pushf(&cld.env, "REMOTE_ADDR=[%s]", buf);
 921                 strvec_pushf(&cld.env, "REMOTE_PORT=%d",
 922                              ntohs(sin6_addr->sin6_port));
 923 #endif
 924         }
 925
 926         strvec_pushv(&cld.args, cld_argv.v);
 927         cld.in = incoming;
 928         cld.out = dup(incoming);
 929
 930         if (start_command(&cld))
 931                 logerror("unable to fork");
 932         else
 933                 add_child(&cld, addr, addrlen);
 934 }
 935
 936 static void child_handler(int signo UNUSED)
 937 {
 938         /*
 939          * Otherwise empty handler because systemcalls will get interrupted
 940          * upon signal receipt
 941          * SysV needs the handler to be rearmed
 942          */
 943         signal(SIGCHLD, child_handler);
 944 }
 945
 946 static int set_reuse_addr(int sockfd)
 947 {
 948         int on = 1;
 949
 950         if (!reuseaddr)
 951                 return 0;
 952         return setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR,
 953                           &on, sizeof(on));
 954 }
 955
 956 struct socketlist {
 957         int *list;
 958         size_t nr;
 959         size_t alloc;
 960 };
 961
 962 static const char *ip2str(int family, struct sockaddr *sin, socklen_t len)
 963 {
 964 #ifdef NO_IPV6
 965         static char ip[INET_ADDRSTRLEN];
 966 #else
 967         static char ip[INET6_ADDRSTRLEN];
 968 #endif
 969
 970         switch (family) {
 971 #ifndef NO_IPV6
 972         case AF_INET6:
 973                 inet_ntop(family, &((struct sockaddr_in6*)sin)->sin6_addr, ip, len);
 974                 break;
 975 #endif
 976         case AF_INET:
 977                 inet_ntop(family, &((struct sockaddr_in*)sin)->sin_addr, ip, len);
 978                 break;
 979         default:
 980                 xsnprintf(ip, sizeof(ip), "<unknown>");
 981         }
 982         return ip;
 983 }
 984
 985 #ifndef NO_IPV6
 986
 987 static int setup_named_sock(char *listen_addr, int listen_port, struct socketlist *socklist)
 988 {
 989         int socknum = 0;
 990         char pbuf[NI_MAXSERV];
 991         struct addrinfo hints, *ai0, *ai;
 992         int gai;
 993         long flags;
 994
 995         xsnprintf(pbuf, sizeof(pbuf), "%d", listen_port);
 996         memset(&hints, 0, sizeof(hints));
 997         hints.ai_family = AF_UNSPEC;
 998         hints.ai_socktype = SOCK_STREAM;
 999         hints.ai_protocol = IPPROTO_TCP;
1000         hints.ai_flags = AI_PASSIVE;
1001
1002         gai = getaddrinfo(listen_addr, pbuf, &hints, &ai0);
1003         if (gai) {
1004                 logerror("getaddrinfo() for %s failed: %s", listen_addr, gai_strerror(gai));
1005                 return 0;
1006         }
1007
1008         for (ai = ai0; ai; ai = ai->ai_next) {
1009                 int sockfd;
1010
1011                 sockfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1012                 if (sockfd < 0)
1013                         continue;
1014                 if (sockfd >= FD_SETSIZE) {
1015                         logerror("Socket descriptor too large");
1016                         close(sockfd);
1017                         continue;
1018                 }
1019
1020 #ifdef IPV6_V6ONLY
1021                 if (ai->ai_family == AF_INET6) {
1022                         int on = 1;
1023                         setsockopt(sockfd, IPPROTO_IPV6, IPV6_V6ONLY,
1024                                    &on, sizeof(on));
1025                         /* Note: error is not fatal */
1026                 }
1027 #endif
1028
1029                 if (set_reuse_addr(sockfd)) {
1030                         logerror("Could not set SO_REUSEADDR: %s", strerror(errno));
1031                         close(sockfd);
1032                         continue;
1033                 }
1034
1035                 set_keep_alive(sockfd);
1036
1037                 if (bind(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
1038                         logerror("Could not bind 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                 if (listen(sockfd, 5) < 0) {
1045                         logerror("Could not listen to %s: %s",
1046                                  ip2str(ai->ai_family, ai->ai_addr, ai->ai_addrlen),
1047                                  strerror(errno));
1048                         close(sockfd);
1049                         continue;       /* not fatal */
1050                 }
1051
1052                 flags = fcntl(sockfd, F_GETFD, 0);
1053                 if (flags >= 0)
1054                         fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
1055
1056                 ALLOC_GROW(socklist->list, socklist->nr + 1, socklist->alloc);
1057                 socklist->list[socklist->nr++] = sockfd;
1058                 socknum++;
1059         }
1060
1061         freeaddrinfo(ai0);
1062
1063         return socknum;
1064 }
1065
1066 #else /* NO_IPV6 */
1067
1068 static int setup_named_sock(char *listen_addr, int listen_port, struct socketlist *socklist)
1069 {
1070         struct sockaddr_in sin;
1071         int sockfd;
1072         long flags;
1073
1074         memset(&sin, 0, sizeof sin);
1075         sin.sin_family = AF_INET;
1076         sin.sin_port = htons(listen_port);
1077
1078         if (listen_addr) {
1079                 /* Well, host better be an IP address here. */
1080                 if (inet_pton(AF_INET, listen_addr, &sin.sin_addr.s_addr) <= 0)
1081                         return 0;
1082         } else {
1083                 sin.sin_addr.s_addr = htonl(INADDR_ANY);
1084         }
1085
1086         sockfd = socket(AF_INET, SOCK_STREAM, 0);
1087         if (sockfd < 0)
1088                 return 0;
1089
1090         if (set_reuse_addr(sockfd)) {
1091                 logerror("Could not set SO_REUSEADDR: %s", strerror(errno));
1092                 close(sockfd);
1093                 return 0;
1094         }
1095
1096         set_keep_alive(sockfd);
1097
1098         if ( bind(sockfd, (struct sockaddr *)&sin, sizeof sin) < 0 ) {
1099                 logerror("Could not bind to %s: %s",
1100                          ip2str(AF_INET, (struct sockaddr *)&sin, sizeof(sin)),
1101                          strerror(errno));
1102                 close(sockfd);
1103                 return 0;
1104         }
1105
1106         if (listen(sockfd, 5) < 0) {
1107                 logerror("Could not listen to %s: %s",
1108                          ip2str(AF_INET, (struct sockaddr *)&sin, sizeof(sin)),
1109                          strerror(errno));
1110                 close(sockfd);
1111                 return 0;
1112         }
1113
1114         flags = fcntl(sockfd, F_GETFD, 0);
1115         if (flags >= 0)
1116                 fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
1117
1118         ALLOC_GROW(socklist->list, socklist->nr + 1, socklist->alloc);
1119         socklist->list[socklist->nr++] = sockfd;
1120         return 1;
1121 }
1122
1123 #endif
1124
1125 static void socksetup(struct string_list *listen_addr, int listen_port, struct socketlist *socklist)
1126 {
1127         if (!listen_addr->nr)
1128                 setup_named_sock(NULL, listen_port, socklist);
1129         else {
1130                 int i, socknum;
1131                 for (i = 0; i < listen_addr->nr; i++) {
1132                         socknum = setup_named_sock(listen_addr->items[i].string,
1133                                                    listen_port, socklist);
1134
1135                         if (socknum == 0)
1136                                 logerror("unable to allocate any listen sockets for host %s on port %u",
1137                                          listen_addr->items[i].string, listen_port);
1138                 }
1139         }
1140 }
1141
1142 static int service_loop(struct socketlist *socklist)
1143 {
1144         struct pollfd *pfd;
1145         int i;
1146
1147         CALLOC_ARRAY(pfd, socklist->nr);
1148
1149         for (i = 0; i < socklist->nr; i++) {
1150                 pfd[i].fd = socklist->list[i];
1151                 pfd[i].events = POLLIN;
1152         }
1153
1154         signal(SIGCHLD, child_handler);
1155
1156         for (;;) {
1157                 int i;
1158
1159                 check_dead_children();
1160
1161                 if (poll(pfd, socklist->nr, -1) < 0) {
1162                         if (errno != EINTR) {
1163                                 logerror("Poll failed, resuming: %s",
1164                                       strerror(errno));
1165                                 sleep(1);
1166                         }
1167                         continue;
1168                 }
1169
1170                 for (i = 0; i < socklist->nr; i++) {
1171                         if (pfd[i].revents & POLLIN) {
1172                                 union {
1173                                         struct sockaddr sa;
1174                                         struct sockaddr_in sai;
1175 #ifndef NO_IPV6
1176                                         struct sockaddr_in6 sai6;
1177 #endif
1178                                 } ss;
1179                                 socklen_t sslen = sizeof(ss);
1180                                 int incoming = accept(pfd[i].fd, &ss.sa, &sslen);
1181                                 if (incoming < 0) {
1182                                         switch (errno) {
1183                                         case EAGAIN:
1184                                         case EINTR:
1185                                         case ECONNABORTED:
1186                                                 continue;
1187                                         default:
1188                                                 die_errno("accept returned");
1189                                         }
1190                                 }
1191                                 handle(incoming, &ss.sa, sslen);
1192                         }
1193                 }
1194         }
1195 }
1196
1197 #ifdef NO_POSIX_GOODIES
1198
1199 struct credentials;
1200
1201 static void drop_privileges(struct credentials *cred)
1202 {
1203         /* nothing */
1204 }
1205
1206 static struct credentials *prepare_credentials(const char *user_name,
1207     const char *group_name)
1208 {
1209         die("--user not supported on this platform");
1210 }
1211
1212 #else
1213
1214 struct credentials {
1215         struct passwd *pass;
1216         gid_t gid;
1217 };
1218
1219 static void drop_privileges(struct credentials *cred)
1220 {
1221         if (cred && (initgroups(cred->pass->pw_name, cred->gid) ||
1222             setgid (cred->gid) || setuid(cred->pass->pw_uid)))
1223                 die("cannot drop privileges");
1224 }
1225
1226 static struct credentials *prepare_credentials(const char *user_name,
1227     const char *group_name)
1228 {
1229         static struct credentials c;
1230
1231         c.pass = getpwnam(user_name);
1232         if (!c.pass)
1233                 die("user not found - %s", user_name);
1234
1235         if (!group_name)
1236                 c.gid = c.pass->pw_gid;
1237         else {
1238                 struct group *group = getgrnam(group_name);
1239                 if (!group)
1240                         die("group not found - %s", group_name);
1241
1242                 c.gid = group->gr_gid;
1243         }
1244
1245         return &c;
1246 }
1247 #endif
1248
1249 static int serve(struct string_list *listen_addr, int listen_port,
1250     struct credentials *cred)
1251 {
1252         struct socketlist socklist = { NULL, 0, 0 };
1253
1254         socksetup(listen_addr, listen_port, &socklist);
1255         if (socklist.nr == 0)
1256                 die("unable to allocate any listen sockets on port %u",
1257                     listen_port);
1258
1259         drop_privileges(cred);
1260
1261         loginfo("Ready to rumble");
1262
1263         return service_loop(&socklist);
1264 }
1265
1266 int cmd_main(int argc, const char **argv)
1267 {
1268         int listen_port = 0;
1269         struct string_list listen_addr = STRING_LIST_INIT_NODUP;
1270         int serve_mode = 0, inetd_mode = 0;
1271         const char *pid_file = NULL, *user_name = NULL, *group_name = NULL;
1272         int detach = 0;
1273         struct credentials *cred = NULL;
1274         int i;
1275
1276         for (i = 1; i < argc; i++) {
1277                 const char *arg = argv[i];
1278                 const char *v;
1279
1280                 if (skip_prefix(arg, "--listen=", &v)) {
1281                         string_list_append(&listen_addr, xstrdup_tolower(v));
1282                         continue;
1283                 }
1284                 if (skip_prefix(arg, "--port=", &v)) {
1285                         char *end;
1286                         unsigned long n;
1287                         n = strtoul(v, &end, 0);
1288                         if (*v && !*end) {
1289                                 listen_port = n;
1290                                 continue;
1291                         }
1292                 }
1293                 if (!strcmp(arg, "--serve")) {
1294                         serve_mode = 1;
1295                         continue;
1296                 }
1297                 if (!strcmp(arg, "--inetd")) {
1298                         inetd_mode = 1;
1299                         continue;
1300                 }
1301                 if (!strcmp(arg, "--verbose")) {
1302                         verbose = 1;
1303                         continue;
1304                 }
1305                 if (!strcmp(arg, "--syslog")) {
1306                         log_destination = LOG_DESTINATION_SYSLOG;
1307                         continue;
1308                 }
1309                 if (skip_prefix(arg, "--log-destination=", &v)) {
1310                         if (!strcmp(v, "syslog")) {
1311                                 log_destination = LOG_DESTINATION_SYSLOG;
1312                                 continue;
1313                         } else if (!strcmp(v, "stderr")) {
1314                                 log_destination = LOG_DESTINATION_STDERR;
1315                                 continue;
1316                         } else if (!strcmp(v, "none")) {
1317                                 log_destination = LOG_DESTINATION_NONE;
1318                                 continue;
1319                         } else
1320                                 die("unknown log destination '%s'", v);
1321                 }
1322                 if (!strcmp(arg, "--export-all")) {
1323                         export_all_trees = 1;
1324                         continue;
1325                 }
1326                 if (skip_prefix(arg, "--access-hook=", &v)) {
1327                         access_hook = v;
1328                         continue;
1329                 }
1330                 if (skip_prefix(arg, "--timeout=", &v)) {
1331                         timeout = atoi(v);
1332                         continue;
1333                 }
1334                 if (skip_prefix(arg, "--init-timeout=", &v)) {
1335                         init_timeout = atoi(v);
1336                         continue;
1337                 }
1338                 if (skip_prefix(arg, "--max-connections=", &v)) {
1339                         max_connections = atoi(v);
1340                         if (max_connections < 0)
1341                                 max_connections = 0;            /* unlimited */
1342                         continue;
1343                 }
1344                 if (!strcmp(arg, "--strict-paths")) {
1345                         strict_paths = 1;
1346                         continue;
1347                 }
1348                 if (skip_prefix(arg, "--base-path=", &v)) {
1349                         base_path = v;
1350                         continue;
1351                 }
1352                 if (!strcmp(arg, "--base-path-relaxed")) {
1353                         base_path_relaxed = 1;
1354                         continue;
1355                 }
1356                 if (skip_prefix(arg, "--interpolated-path=", &v)) {
1357                         interpolated_path = v;
1358                         continue;
1359                 }
1360                 if (!strcmp(arg, "--reuseaddr")) {
1361                         reuseaddr = 1;
1362                         continue;
1363                 }
1364                 if (!strcmp(arg, "--user-path")) {
1365                         user_path = "";
1366                         continue;
1367                 }
1368                 if (skip_prefix(arg, "--user-path=", &v)) {
1369                         user_path = v;
1370                         continue;
1371                 }
1372                 if (skip_prefix(arg, "--pid-file=", &v)) {
1373                         pid_file = v;
1374                         continue;
1375                 }
1376                 if (!strcmp(arg, "--detach")) {
1377                         detach = 1;
1378                         continue;
1379                 }
1380                 if (skip_prefix(arg, "--user=", &v)) {
1381                         user_name = v;
1382                         continue;
1383                 }
1384                 if (skip_prefix(arg, "--group=", &v)) {
1385                         group_name = v;
1386                         continue;
1387                 }
1388                 if (skip_prefix(arg, "--enable=", &v)) {
1389                         enable_service(v, 1);
1390                         continue;
1391                 }
1392                 if (skip_prefix(arg, "--disable=", &v)) {
1393                         enable_service(v, 0);
1394                         continue;
1395                 }
1396                 if (skip_prefix(arg, "--allow-override=", &v)) {
1397                         make_service_overridable(v, 1);
1398                         continue;
1399                 }
1400                 if (skip_prefix(arg, "--forbid-override=", &v)) {
1401                         make_service_overridable(v, 0);
1402                         continue;
1403                 }
1404                 if (!strcmp(arg, "--informative-errors")) {
1405                         informative_errors = 1;
1406                         continue;
1407                 }
1408                 if (!strcmp(arg, "--no-informative-errors")) {
1409                         informative_errors = 0;
1410                         continue;
1411                 }
1412                 if (!strcmp(arg, "--")) {
1413                         ok_paths = &argv[i+1];
1414                         break;
1415                 } else if (arg[0] != '-') {
1416                         ok_paths = &argv[i];
1417                         break;
1418                 }
1419
1420                 usage(daemon_usage);
1421         }
1422
1423         if (log_destination == LOG_DESTINATION_UNSET) {
1424                 if (inetd_mode || detach)
1425                         log_destination = LOG_DESTINATION_SYSLOG;
1426                 else
1427                         log_destination = LOG_DESTINATION_STDERR;
1428         }
1429
1430         if (log_destination == LOG_DESTINATION_SYSLOG) {
1431                 openlog("git-daemon", LOG_PID, LOG_DAEMON);
1432                 set_die_routine(daemon_die);
1433         } else
1434                 /* avoid splitting a message in the middle */
1435                 setvbuf(stderr, NULL, _IOFBF, 4096);
1436
1437         if (inetd_mode && (detach || group_name || user_name))
1438                 die("--detach, --user and --group are incompatible with --inetd");
1439
1440         if (inetd_mode && (listen_port || (listen_addr.nr > 0)))
1441                 die("--listen= and --port= are incompatible with --inetd");
1442         else if (listen_port == 0)
1443                 listen_port = DEFAULT_GIT_PORT;
1444
1445         if (group_name && !user_name)
1446                 die("--group supplied without --user");
1447
1448         if (user_name)
1449                 cred = prepare_credentials(user_name, group_name);
1450
1451         if (strict_paths && (!ok_paths || !*ok_paths))
1452                 die("option --strict-paths requires '<directory>' arguments");
1453
1454         if (base_path && !is_directory(base_path))
1455                 die("base-path '%s' does not exist or is not a directory",
1456                     base_path);
1457
1458         if (log_destination != LOG_DESTINATION_STDERR) {
1459                 if (!freopen("/dev/null", "w", stderr))
1460                         die_errno("failed to redirect stderr to /dev/null");
1461         }
1462
1463         if (inetd_mode || serve_mode)
1464                 return execute();
1465
1466         if (detach) {
1467                 if (daemonize())
1468                         die("--detach not supported on this platform");
1469         }
1470
1471         if (pid_file)
1472                 write_file(pid_file, "%"PRIuMAX, (uintmax_t) getpid());
1473
1474         /* prepare argv for serving-processes */
1475         strvec_push(&cld_argv, argv[0]); /* git-daemon */
1476         strvec_push(&cld_argv, "--serve");
1477         for (i = 1; i < argc; ++i)
1478                 strvec_push(&cld_argv, argv[i]);
1479
1480         return serve(&listen_addr, listen_port, cred);
1481 }