daemon.c

   1 #define USE_THE_REPOSITORY_VARIABLE
   2
   3 #include "git-compat-util.h"
   4 #include "abspath.h"
   5 #include "config.h"
   6 #include "environment.h"
   7 #include "gettext.h"
   8 #include "path.h"
   9 #include "pkt-line.h"
  10 #include "protocol.h"
  11 #include "run-command.h"
  12 #include "setup.h"
  13 #include "strbuf.h"
  14 #include "string-list.h"
  15
  16 #ifdef NO_INITGROUPS
  17 #define initgroups(x, y) (0) /* nothing */
  18 #endif
  19
  20 static enum log_destination {
  21         LOG_DESTINATION_UNSET = -1,
  22         LOG_DESTINATION_NONE = 0,
  23         LOG_DESTINATION_STDERR = 1,
  24         LOG_DESTINATION_SYSLOG = 2,
  25 } log_destination = LOG_DESTINATION_UNSET;
  26 static int verbose;
  27 static int reuseaddr;
  28 static int informative_errors;
  29
  30 static const char daemon_usage[] =
  31 "git daemon [--verbose] [--syslog] [--export-all]\n"
  32 "           [--timeout=<n>] [--init-timeout=<n>] [--max-connections=<n>]\n"
  33 "           [--strict-paths] [--base-path=<path>] [--base-path-relaxed]\n"
  34 "           [--user-path | --user-path=<path>]\n"
  35 "           [--interpolated-path=<path>]\n"
  36 "           [--reuseaddr] [--pid-file=<file>]\n"
  37 "           [--(enable|disable|allow-override|forbid-override)=<service>]\n"
  38 "           [--access-hook=<path>]\n"
  39 "           [--inetd | [--listen=<host_or_ipaddr>] [--port=<n>]\n"
  40 "                      [--detach] [--user=<user> [--group=<group>]]\n"
  41 "           [--log-destination=(stderr|syslog|none)]\n"
  42 "           [<directory>...]";
  43
  44 /* List of acceptable pathname prefixes */
  45 static const char **ok_paths;
  46 static int strict_paths;
  47
  48 /* If this is set, git-daemon-export-ok is not required */
  49 static int export_all_trees;
  50
  51 /* Take all paths relative to this one if non-NULL */
  52 static const char *base_path;
  53 static const char *interpolated_path;
  54 static int base_path_relaxed;
  55
  56 /* If defined, ~user notation is allowed and the string is inserted
  57  * after ~user/.  E.g. a request to git://host/~alice/frotz would
  58  * go to /home/alice/pub_git/frotz with --user-path=pub_git.
  59  */
  60 static const char *user_path;
  61
  62 /* Timeout, and initial timeout */
  63 static unsigned int timeout;
  64 static unsigned int init_timeout;
  65
  66 struct hostinfo {
  67         struct strbuf hostname;
  68         struct strbuf canon_hostname;
  69         struct strbuf ip_address;
  70         struct strbuf tcp_port;
  71         unsigned int hostname_lookup_done:1;
  72         unsigned int saw_extended_args:1;
  73 };
  74 #define HOSTINFO_INIT { \
  75         .hostname = STRBUF_INIT, \
  76         .canon_hostname = STRBUF_INIT, \
  77         .ip_address = STRBUF_INIT, \
  78         .tcp_port = STRBUF_INIT, \
  79 }
  80
  81 static void lookup_hostname(struct hostinfo *hi);
  82
  83 static const char *get_canon_hostname(struct hostinfo *hi)
  84 {
  85         lookup_hostname(hi);
  86         return hi->canon_hostname.buf;
  87 }
  88
  89 static const char *get_ip_address(struct hostinfo *hi)
  90 {
  91         lookup_hostname(hi);
  92         return hi->ip_address.buf;
  93 }
  94
  95 static void logreport(int priority, const char *err, va_list params)
  96 {
  97         switch (log_destination) {
  98         case LOG_DESTINATION_SYSLOG: {
  99                 char buf[1024];
 100                 vsnprintf(buf, sizeof(buf), err, params);
 101                 syslog(priority, "%s", buf);
 102                 break;
 103         }
 104         case LOG_DESTINATION_STDERR:
 105                 /*
 106                  * Since stderr is set to buffered mode, the
 107                  * logging of different processes will not overlap
 108                  * unless they overflow the (rather big) buffers.
 109                  */
 110                 fprintf(stderr, "[%"PRIuMAX"] ", (uintmax_t)getpid());
 111                 vfprintf(stderr, err, params);
 112                 fputc('\n', stderr);
 113                 fflush(stderr);
 114                 break;
 115         case LOG_DESTINATION_NONE:
 116                 break;
 117         case LOG_DESTINATION_UNSET:
 118                 BUG("log destination not initialized correctly");
 119         }
 120 }
 121
 122 __attribute__((format (printf, 1, 2)))
 123 static void logerror(const char *err, ...)
 124 {
 125         va_list params;
 126         va_start(params, err);
 127         logreport(LOG_ERR, err, params);
 128         va_end(params);
 129 }
 130
 131 __attribute__((format (printf, 1, 2)))
 132 static void loginfo(const char *err, ...)
 133 {
 134         va_list params;
 135         if (!verbose)
 136                 return;
 137         va_start(params, err);
 138         logreport(LOG_INFO, err, params);
 139         va_end(params);
 140 }
 141
 142 static void NORETURN daemon_die(const char *err, va_list params)
 143 {
 144         logreport(LOG_ERR, err, params);
 145         exit(1);
 146 }
 147
 148 static const char *path_ok(const char *directory, struct hostinfo *hi)
 149 {
 150         static char rpath[PATH_MAX];
 151         static char interp_path[PATH_MAX];
 152         size_t rlen;
 153         const char *path;
 154         const char *dir;
 155
 156         dir = directory;
 157
 158         if (daemon_avoid_alias(dir)) {
 159                 logerror("'%s': aliased", dir);
 160                 return NULL;
 161         }
 162
 163         if (*dir == '~') {
 164                 if (!user_path) {
 165                         logerror("'%s': User-path not allowed", dir);
 166                         return NULL;
 167                 }
 168                 if (*user_path) {
 169                         /* Got either "~alice" or "~alice/foo";
 170                          * rewrite them to "~alice/%s" or
 171                          * "~alice/%s/foo".
 172                          */
 173                         int namlen, restlen = strlen(dir);
 174                         const char *slash = strchr(dir, '/');
 175                         if (!slash)
 176                                 slash = dir + restlen;
 177                         namlen = slash - dir;
 178                         restlen -= namlen;
 179                         loginfo("userpath <%s>, request <%s>, namlen %d, restlen %d, slash <%s>", user_path, dir, namlen, restlen, slash);
 180                         rlen = snprintf(rpath, sizeof(rpath), "%.*s/%s%.*s",
 181                                         namlen, dir, user_path, restlen, slash);
 182                         if (rlen >= sizeof(rpath)) {
 183                                 logerror("user-path too large: %s", rpath);
 184                                 return NULL;
 185                         }
 186                         dir = rpath;
 187                 }
 188         }
 189         else if (interpolated_path && hi->saw_extended_args) {
 190                 struct strbuf expanded_path = STRBUF_INIT;
 191                 const char *format = interpolated_path;
 192
 193                 if (*dir != '/') {
 194                         /* Allow only absolute */
 195                         logerror("'%s': Non-absolute path denied (interpolated-path active)", dir);
 196                         return NULL;
 197                 }
 198
 199                 while (strbuf_expand_step(&expanded_path, &format)) {
 200                         if (skip_prefix(format, "%", &format))
 201                                 strbuf_addch(&expanded_path, '%');
 202                         else if (skip_prefix(format, "H", &format))
 203                                 strbuf_addbuf(&expanded_path, &hi->hostname);
 204                         else if (skip_prefix(format, "CH", &format))
 205                                 strbuf_addstr(&expanded_path,
 206                                               get_canon_hostname(hi));
 207                         else if (skip_prefix(format, "IP", &format))
 208                                 strbuf_addstr(&expanded_path,
 209                                               get_ip_address(hi));
 210                         else if (skip_prefix(format, "P", &format))
 211                                 strbuf_addbuf(&expanded_path, &hi->tcp_port);
 212                         else if (skip_prefix(format, "D", &format))
 213                                 strbuf_addstr(&expanded_path, directory);
 214                         else
 215                                 strbuf_addch(&expanded_path, '%');
 216                 }
 217
 218                 rlen = strlcpy(interp_path, expanded_path.buf,
 219                                sizeof(interp_path));
 220                 strbuf_release(&expanded_path);
 221                 if (rlen >= sizeof(interp_path)) {
 222                         logerror("interpolated path too large: %s",
 223                                  interp_path);
 224                         return NULL;
 225                 }
 226
 227                 loginfo("Interpolated dir '%s'", interp_path);
 228
 229                 dir = interp_path;
 230         }
 231         else if (base_path) {
 232                 if (*dir != '/') {
 233                         /* Allow only absolute */
 234                         logerror("'%s': Non-absolute path denied (base-path active)", dir);
 235                         return NULL;
 236                 }
 237                 rlen = snprintf(rpath, sizeof(rpath), "%s%s", base_path, dir);
 238                 if (rlen >= sizeof(rpath)) {
 239                         logerror("base-path too large: %s", rpath);
 240                         return NULL;
 241                 }
 242                 dir = rpath;
 243         }
 244
 245         path = enter_repo(dir, strict_paths);
 246         if (!path && base_path && base_path_relaxed) {
 247                 /*
 248                  * if we fail and base_path_relaxed is enabled, try without
 249                  * prefixing the base path
 250                  */
 251                 dir = directory;
 252                 path = enter_repo(dir, strict_paths);
 253         }
 254
 255         if (!path) {
 256                 logerror("'%s' does not appear to be a git repository", dir);
 257                 return NULL;
 258         }
 259
 260         if ( ok_paths && *ok_paths ) {
 261                 const char **pp;
 262                 int pathlen = strlen(path);
 263
 264                 /* The validation is done on the paths after enter_repo
 265                  * appends optional {.git,.git/.git} and friends, but
 266                  * it does not use getcwd().  So if your /pub is
 267                  * a symlink to /mnt/pub, you can include /pub and
 268                  * do not have to say /mnt/pub.
 269                  * Do not say /pub/.
 270                  */
 271                 for ( pp = ok_paths ; *pp ; pp++ ) {
 272                         int len = strlen(*pp);
 273                         if (len <= pathlen &&
 274                             !memcmp(*pp, path, len) &&
 275                             (path[len] == '\0' ||
 276                              (!strict_paths && path[len] == '/')))
 277                                 return path;
 278                 }
 279         }
 280         else {
 281                 /* be backwards compatible */
 282                 if (!strict_paths)
 283                         return path;
 284         }
 285
 286         logerror("'%s': not in directory list", path);
 287         return NULL;            /* Fallthrough. Deny by default */
 288 }
 289
 290 typedef int (*daemon_service_fn)(const struct strvec *env);
 291 struct daemon_service {
 292         const char *name;
 293         const char *config_name;
 294         daemon_service_fn fn;
 295         int enabled;
 296         int overridable;
 297 };
 298
 299 static int daemon_error(const char *dir, const char *msg)
 300 {
 301         if (!informative_errors)
 302                 msg = "access denied or repository not exported";
 303         packet_write_fmt(1, "ERR %s: %s", msg, dir);
 304         return -1;
 305 }
 306
 307 static const char *access_hook;
 308
 309 static int run_access_hook(struct daemon_service *service, const char *dir,
 310                            const char *path, struct hostinfo *hi)
 311 {
 312         struct child_process child = CHILD_PROCESS_INIT;
 313         struct strbuf buf = STRBUF_INIT;
 314         char *eol;
 315         int seen_errors = 0;
 316
 317         strvec_push(&child.args, access_hook);
 318         strvec_push(&child.args, service->name);
 319         strvec_push(&child.args, path);
 320         strvec_push(&child.args, hi->hostname.buf);
 321         strvec_push(&child.args, get_canon_hostname(hi));
 322         strvec_push(&child.args, get_ip_address(hi));
 323         strvec_push(&child.args, hi->tcp_port.buf);
 324
 325         child.use_shell = 1;
 326         child.no_stdin = 1;
 327         child.no_stderr = 1;
 328         child.out = -1;
 329         if (start_command(&child)) {
 330                 logerror("daemon access hook '%s' failed to start",
 331                          access_hook);
 332                 goto error_return;
 333         }
 334         if (strbuf_read(&buf, child.out, 0) < 0) {
 335                 logerror("failed to read from pipe to daemon access hook '%s'",
 336                          access_hook);
 337                 strbuf_reset(&buf);
 338                 seen_errors = 1;
 339         }
 340         if (close(child.out) < 0) {
 341                 logerror("failed to close pipe to daemon access hook '%s'",
 342                          access_hook);
 343                 seen_errors = 1;
 344         }
 345         if (finish_command(&child))
 346                 seen_errors = 1;
 347
 348         if (!seen_errors) {
 349                 strbuf_release(&buf);
 350                 return 0;
 351         }
 352
 353 error_return:
 354         strbuf_ltrim(&buf);
 355         if (!buf.len)
 356                 strbuf_addstr(&buf, "service rejected");
 357         eol = strchr(buf.buf, '\n');
 358         if (eol)
 359                 *eol = '\0';
 360         errno = EACCES;
 361         daemon_error(dir, buf.buf);
 362         strbuf_release(&buf);
 363         return -1;
 364 }
 365
 366 static int run_service(const char *dir, struct daemon_service *service,
 367                        struct hostinfo *hi, const struct strvec *env)
 368 {
 369         const char *path;
 370         int enabled = service->enabled;
 371         struct strbuf var = STRBUF_INIT;
 372
 373         loginfo("Request %s for '%s'", service->name, dir);
 374
 375         if (!enabled && !service->overridable) {
 376                 logerror("'%s': service not enabled.", service->name);
 377                 errno = EACCES;
 378                 return daemon_error(dir, "service not enabled");
 379         }
 380
 381         if (!(path = path_ok(dir, hi)))
 382                 return daemon_error(dir, "no such repository");
 383
 384         /*
 385          * Security on the cheap.
 386          *
 387          * We want a readable HEAD, usable "objects" directory, and
 388          * a "git-daemon-export-ok" flag that says that the other side
 389          * is ok with us doing this.
 390          *
 391          * path_ok() uses enter_repo() and checks for included directories.
 392          * We only need to make sure the repository is exported.
 393          */
 394
 395         if (!export_all_trees && access("git-daemon-export-ok", F_OK)) {
 396                 logerror("'%s': repository not exported.", path);
 397                 errno = EACCES;
 398                 return daemon_error(dir, "repository not exported");
 399         }
 400
 401         if (service->overridable) {
 402                 strbuf_addf(&var, "daemon.%s", service->config_name);
 403                 git_config_get_bool(var.buf, &enabled);
 404                 strbuf_release(&var);
 405         }
 406         if (!enabled) {
 407                 logerror("'%s': service not enabled for '%s'",
 408                          service->name, path);
 409                 errno = EACCES;
 410                 return daemon_error(dir, "service not enabled");
 411         }
 412
 413         /*
 414          * Optionally, a hook can choose to deny access to the
 415          * repository depending on the phase of the moon.
 416          */
 417         if (access_hook && run_access_hook(service, dir, path, hi))
 418                 return -1;
 419
 420         /*
 421          * We'll ignore SIGTERM from now on, we have a
 422          * good client.
 423          */
 424         signal(SIGTERM, SIG_IGN);
 425
 426         return service->fn(env);
 427 }
 428
 429 static void copy_to_log(int fd)
 430 {
 431         struct strbuf line = STRBUF_INIT;
 432         FILE *fp;
 433
 434         fp = fdopen(fd, "r");
 435         if (!fp) {
 436                 logerror("fdopen of error channel failed");
 437                 close(fd);
 438                 return;
 439         }
 440
 441         while (strbuf_getline_lf(&line, fp) != EOF) {
 442                 logerror("%s", line.buf);
 443                 strbuf_setlen(&line, 0);
 444         }
 445
 446         strbuf_release(&line);
 447         fclose(fp);
 448 }
 449
 450 static int run_service_command(struct child_process *cld)
 451 {
 452         strvec_push(&cld->args, ".");
 453         cld->git_cmd = 1;
 454         cld->err = -1;
 455         if (start_command(cld))
 456                 return -1;
 457
 458         close(0);
 459         close(1);
 460
 461         copy_to_log(cld->err);
 462
 463         return finish_command(cld);
 464 }
 465
 466 static int upload_pack(const struct strvec *env)
 467 {
 468         struct child_process cld = CHILD_PROCESS_INIT;
 469         strvec_pushl(&cld.args, "upload-pack", "--strict", NULL);
 470         strvec_pushf(&cld.args, "--timeout=%u", timeout);
 471
 472         strvec_pushv(&cld.env, env->v);
 473
 474         return run_service_command(&cld);
 475 }
 476
 477 static int upload_archive(const struct strvec *env)
 478 {
 479         struct child_process cld = CHILD_PROCESS_INIT;
 480         strvec_push(&cld.args, "upload-archive");
 481
 482         strvec_pushv(&cld.env, env->v);
 483
 484         return run_service_command(&cld);
 485 }
 486
 487 static int receive_pack(const struct strvec *env)
 488 {
 489         struct child_process cld = CHILD_PROCESS_INIT;
 490         strvec_push(&cld.args, "receive-pack");
 491
 492         strvec_pushv(&cld.env, env->v);
 493
 494         return run_service_command(&cld);
 495 }
 496
 497 static struct daemon_service daemon_service[] = {
 498         { "upload-archive", "uploadarch", upload_archive, 0, 1 },
 499         { "upload-pack", "uploadpack", upload_pack, 1, 1 },
 500         { "receive-pack", "receivepack", receive_pack, 0, 1 },
 501 };
 502
 503 static void enable_service(const char *name, int ena)
 504 {
 505         int i;
 506         for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
 507                 if (!strcmp(daemon_service[i].name, name)) {
 508                         daemon_service[i].enabled = ena;
 509                         return;
 510                 }
 511         }
 512         die("No such service %s", name);
 513 }
 514
 515 static void make_service_overridable(const char *name, int ena)
 516 {
 517         int i;
 518         for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
 519                 if (!strcmp(daemon_service[i].name, name)) {
 520                         daemon_service[i].overridable = ena;
 521                         return;
 522                 }
 523         }
 524         die("No such service %s", name);
 525 }
 526
 527 static void parse_host_and_port(char *hostport, char **host,
 528         char **port)
 529 {
 530         if (*hostport == '[') {
 531                 char *end;
 532
 533                 end = strchr(hostport, ']');
 534                 if (!end)
 535                         die("Invalid request ('[' without ']')");
 536                 *end = '\0';
 537                 *host = hostport + 1;
 538                 if (!end[1])
 539                         *port = NULL;
 540                 else if (end[1] == ':')
 541                         *port = end + 2;
 542                 else
 543                         die("Garbage after end of host part");
 544         } else {
 545                 *host = hostport;
 546                 *port = strrchr(hostport, ':');
 547                 if (*port) {
 548                         **port = '\0';
 549                         ++*port;
 550                 }
 551         }
 552 }
 553
 554 /*
 555  * Sanitize a string from the client so that it's OK to be inserted into a
 556  * filesystem path. Specifically, we disallow directory separators, runs
 557  * of "..", and trailing and leading dots, which means that the client
 558  * cannot escape our base path via ".." traversal.
 559  */
 560 static void sanitize_client(struct strbuf *out, const char *in)
 561 {
 562         for (; *in; in++) {
 563                 if (is_dir_sep(*in))
 564                         continue;
 565                 if (*in == '.' && (!out->len || out->buf[out->len - 1] == '.'))
 566                         continue;
 567                 strbuf_addch(out, *in);
 568         }
 569
 570         while (out->len && out->buf[out->len - 1] == '.')
 571                 strbuf_setlen(out, out->len - 1);
 572 }
 573
 574 /*
 575  * Like sanitize_client, but we also perform any canonicalization
 576  * to make life easier on the admin.
 577  */
 578 static void canonicalize_client(struct strbuf *out, const char *in)
 579 {
 580         sanitize_client(out, in);
 581         strbuf_tolower(out);
 582 }
 583
 584 /*
 585  * Read the host as supplied by the client connection.
 586  *
 587  * Returns a pointer to the character after the NUL byte terminating the host
 588  * argument, or 'extra_args' if there is no host argument.
 589  */
 590 static char *parse_host_arg(struct hostinfo *hi, char *extra_args, int buflen)
 591 {
 592         char *val;
 593         int vallen;
 594         char *end = extra_args + buflen;
 595
 596         if (extra_args < end && *extra_args) {
 597                 hi->saw_extended_args = 1;
 598                 if (strncasecmp("host=", extra_args, 5) == 0) {
 599                         val = extra_args + 5;
 600                         vallen = strlen(val) + 1;
 601                         loginfo("Extended attribute \"host\": %s", val);
 602                         if (*val) {
 603                                 /* Split <host>:<port> at colon. */
 604                                 char *host;
 605                                 char *port;
 606                                 parse_host_and_port(val, &host, &port);
 607                                 if (port)
 608                                         sanitize_client(&hi->tcp_port, port);
 609                                 canonicalize_client(&hi->hostname, host);
 610                                 hi->hostname_lookup_done = 0;
 611                         }
 612
 613                         /* On to the next one */
 614                         extra_args = val + vallen;
 615                 }
 616                 if (extra_args < end && *extra_args)
 617                         die("Invalid request");
 618         }
 619
 620         return extra_args;
 621 }
 622
 623 static void parse_extra_args(struct hostinfo *hi, struct strvec *env,
 624                              char *extra_args, int buflen)
 625 {
 626         const char *end = extra_args + buflen;
 627         struct strbuf git_protocol = STRBUF_INIT;
 628
 629         /* First look for the host argument */
 630         extra_args = parse_host_arg(hi, extra_args, buflen);
 631
 632         /* Look for additional arguments places after a second NUL byte */
 633         for (; extra_args < end; extra_args += strlen(extra_args) + 1) {
 634                 const char *arg = extra_args;
 635
 636                 /*
 637                  * Parse the extra arguments, adding most to 'git_protocol'
 638                  * which will be used to set the 'GIT_PROTOCOL' envvar in the
 639                  * service that will be run.
 640                  *
 641                  * If there ends up being a particular arg in the future that
 642                  * git-daemon needs to parse specifically (like the 'host' arg)
 643                  * then it can be parsed here and not added to 'git_protocol'.
 644                  */
 645                 if (*arg) {
 646                         if (git_protocol.len > 0)
 647                                 strbuf_addch(&git_protocol, ':');
 648                         strbuf_addstr(&git_protocol, arg);
 649                 }
 650         }
 651
 652         if (git_protocol.len > 0) {
 653                 loginfo("Extended attribute \"protocol\": %s", git_protocol.buf);
 654                 strvec_pushf(env, GIT_PROTOCOL_ENVIRONMENT "=%s",
 655                              git_protocol.buf);
 656         }
 657         strbuf_release(&git_protocol);
 658 }
 659
 660 /*
 661  * Locate canonical hostname and its IP address.
 662  */
 663 static void lookup_hostname(struct hostinfo *hi)
 664 {
 665         if (!hi->hostname_lookup_done && hi->hostname.len) {
 666 #ifndef NO_IPV6
 667                 struct addrinfo hints;
 668                 struct addrinfo *ai;
 669                 int gai;
 670                 static char addrbuf[HOST_NAME_MAX + 1];
 671
 672                 memset(&hints, 0, sizeof(hints));
 673                 hints.ai_flags = AI_CANONNAME;
 674
 675                 gai = getaddrinfo(hi->hostname.buf, NULL, &hints, &ai);
 676                 if (!gai) {
 677                         struct sockaddr_in *sin_addr = (void *)ai->ai_addr;
 678
 679                         inet_ntop(AF_INET, &sin_addr->sin_addr,
 680                                   addrbuf, sizeof(addrbuf));
 681                         strbuf_addstr(&hi->ip_address, addrbuf);
 682
 683                         if (ai->ai_canonname)
 684                                 sanitize_client(&hi->canon_hostname,
 685                                                 ai->ai_canonname);
 686                         else
 687                                 strbuf_addbuf(&hi->canon_hostname,
 688                                               &hi->ip_address);
 689
 690                         freeaddrinfo(ai);
 691                 }
 692 #else
 693                 struct hostent *hent;
 694                 struct sockaddr_in sa;
 695                 char **ap;
 696                 static char addrbuf[HOST_NAME_MAX + 1];
 697
 698                 hent = gethostbyname(hi->hostname.buf);
 699                 if (hent) {
 700                         ap = hent->h_addr_list;
 701                         memset(&sa, 0, sizeof sa);
 702                         sa.sin_family = hent->h_addrtype;
 703                         sa.sin_port = htons(0);
 704                         memcpy(&sa.sin_addr, *ap, hent->h_length);
 705
 706                         inet_ntop(hent->h_addrtype, &sa.sin_addr,
 707                                   addrbuf, sizeof(addrbuf));
 708
 709                         sanitize_client(&hi->canon_hostname, hent->h_name);
 710                         strbuf_addstr(&hi->ip_address, addrbuf);
 711                 }
 712 #endif
 713                 hi->hostname_lookup_done = 1;
 714         }
 715 }
 716
 717 static void hostinfo_clear(struct hostinfo *hi)
 718 {
 719         strbuf_release(&hi->hostname);
 720         strbuf_release(&hi->canon_hostname);
 721         strbuf_release(&hi->ip_address);
 722         strbuf_release(&hi->tcp_port);
 723 }
 724
 725 static void set_keep_alive(int sockfd)
 726 {
 727         int ka = 1;
 728
 729         if (setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, &ka, sizeof(ka)) < 0) {
 730                 if (errno != ENOTSOCK)
 731                         logerror("unable to set SO_KEEPALIVE on socket: %s",
 732                                 strerror(errno));
 733         }
 734 }
 735
 736 static int execute(void)
 737 {
 738         char *line = packet_buffer;
 739         int pktlen, len, i;
 740         char *addr = getenv("REMOTE_ADDR"), *port = getenv("REMOTE_PORT");
 741         struct hostinfo hi = HOSTINFO_INIT;
 742         struct strvec env = STRVEC_INIT;
 743
 744         if (addr)
 745                 loginfo("Connection from %s:%s", addr, port);
 746
 747         set_keep_alive(0);
 748         alarm(init_timeout ? init_timeout : timeout);
 749         pktlen = packet_read(0, packet_buffer, sizeof(packet_buffer), 0);
 750         alarm(0);
 751
 752         len = strlen(line);
 753         if (len && line[len-1] == '\n')
 754                 line[len-1] = 0;
 755
 756         /* parse additional args hidden behind a NUL byte */
 757         if (len != pktlen)
 758                 parse_extra_args(&hi, &env, line + len + 1, pktlen - len - 1);
 759
 760         for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
 761                 struct daemon_service *s = &(daemon_service[i]);
 762                 const char *arg;
 763
 764                 if (skip_prefix(line, "git-", &arg) &&
 765                     skip_prefix(arg, s->name, &arg) &&
 766                     *arg++ == ' ') {
 767                         /*
 768                          * Note: The directory here is probably context sensitive,
 769                          * and might depend on the actual service being performed.
 770                          */
 771                         int rc = run_service(arg, s, &hi, &env);
 772                         hostinfo_clear(&hi);
 773                         strvec_clear(&env);
 774                         return rc;
 775                 }
 776         }
 777
 778         hostinfo_clear(&hi);
 779         strvec_clear(&env);
 780         logerror("Protocol error: '%s'", line);
 781         return -1;
 782 }
 783
 784 static int addrcmp(const struct sockaddr_storage *s1,
 785     const struct sockaddr_storage *s2)
 786 {
 787         const struct sockaddr *sa1 = (const struct sockaddr*) s1;
 788         const struct sockaddr *sa2 = (const struct sockaddr*) s2;
 789
 790         if (sa1->sa_family != sa2->sa_family)
 791                 return sa1->sa_family - sa2->sa_family;
 792         if (sa1->sa_family == AF_INET)
 793                 return memcmp(&((struct sockaddr_in *)s1)->sin_addr,
 794                     &((struct sockaddr_in *)s2)->sin_addr,
 795                     sizeof(struct in_addr));
 796 #ifndef NO_IPV6
 797         if (sa1->sa_family == AF_INET6)
 798                 return memcmp(&((struct sockaddr_in6 *)s1)->sin6_addr,
 799                     &((struct sockaddr_in6 *)s2)->sin6_addr,
 800                     sizeof(struct in6_addr));
 801 #endif
 802         return 0;
 803 }
 804
 805 static int max_connections = 32;
 806
 807 static unsigned int live_children;
 808
 809 static struct child {
 810         struct child *next;
 811         struct child_process cld;
 812         struct sockaddr_storage address;
 813 } *firstborn;
 814
 815 static void add_child(struct child_process *cld, struct sockaddr *addr, socklen_t addrlen)
 816 {
 817         struct child *newborn, **cradle;
 818
 819         CALLOC_ARRAY(newborn, 1);
 820         live_children++;
 821         memcpy(&newborn->cld, cld, sizeof(*cld));
 822         memcpy(&newborn->address, addr, addrlen);
 823         for (cradle = &firstborn; *cradle; cradle = &(*cradle)->next)
 824                 if (!addrcmp(&(*cradle)->address, &newborn->address))
 825                         break;
 826         newborn->next = *cradle;
 827         *cradle = newborn;
 828 }
 829
 830 /*
 831  * This gets called if the number of connections grows
 832  * past "max_connections".
 833  *
 834  * We kill the newest connection from a duplicate IP.
 835  */
 836 static void kill_some_child(void)
 837 {
 838         const struct child *blanket, *next;
 839
 840         if (!(blanket = firstborn))
 841                 return;
 842
 843         for (; (next = blanket->next); blanket = next)
 844                 if (!addrcmp(&blanket->address, &next->address)) {
 845                         kill(blanket->cld.pid, SIGTERM);
 846                         break;
 847                 }
 848 }
 849
 850 static void check_dead_children(void)
 851 {
 852         int status;
 853         pid_t pid;
 854
 855         struct child **cradle, *blanket;
 856         for (cradle = &firstborn; (blanket = *cradle);)
 857                 if ((pid = waitpid(blanket->cld.pid, &status, WNOHANG)) > 1) {
 858                         const char *dead = "";
 859                         if (status)
 860                                 dead = " (with error)";
 861                         loginfo("[%"PRIuMAX"] Disconnected%s", (uintmax_t)pid, dead);
 862
 863                         /* remove the child */
 864                         *cradle = blanket->next;
 865                         live_children--;
 866                         child_process_clear(&blanket->cld);
 867                         free(blanket);
 868                 } else
 869                         cradle = &blanket->next;
 870 }
 871
 872 static struct strvec cld_argv = STRVEC_INIT;
 873 static void handle(int incoming, struct sockaddr *addr, socklen_t addrlen)
 874 {
 875         struct child_process cld = CHILD_PROCESS_INIT;
 876
 877         if (max_connections && live_children >= max_connections) {
 878                 kill_some_child();
 879                 sleep(1);  /* give it some time to die */
 880                 check_dead_children();
 881                 if (live_children >= max_connections) {
 882                         close(incoming);
 883                         logerror("Too many children, dropping connection");
 884                         return;
 885                 }
 886         }
 887
 888         if (addr->sa_family == AF_INET) {
 889                 char buf[128] = "";
 890                 struct sockaddr_in *sin_addr = (void *) addr;
 891                 inet_ntop(addr->sa_family, &sin_addr->sin_addr, buf, sizeof(buf));
 892                 strvec_pushf(&cld.env, "REMOTE_ADDR=%s", buf);
 893                 strvec_pushf(&cld.env, "REMOTE_PORT=%d",
 894                              ntohs(sin_addr->sin_port));
 895 #ifndef NO_IPV6
 896         } else if (addr->sa_family == AF_INET6) {
 897                 char buf[128] = "";
 898                 struct sockaddr_in6 *sin6_addr = (void *) addr;
 899                 inet_ntop(AF_INET6, &sin6_addr->sin6_addr, buf, sizeof(buf));
 900                 strvec_pushf(&cld.env, "REMOTE_ADDR=[%s]", buf);
 901                 strvec_pushf(&cld.env, "REMOTE_PORT=%d",
 902                              ntohs(sin6_addr->sin6_port));
 903 #endif
 904         }
 905
 906         strvec_pushv(&cld.args, cld_argv.v);
 907         cld.in = incoming;
 908         cld.out = dup(incoming);
 909
 910         if (start_command(&cld))
 911                 logerror("unable to fork");
 912         else
 913                 add_child(&cld, addr, addrlen);
 914 }
 915
 916 static void child_handler(int signo UNUSED)
 917 {
 918         /*
 919          * Otherwise empty handler because systemcalls will get interrupted
 920          * upon signal receipt
 921          * SysV needs the handler to be rearmed
 922          */
 923         signal(SIGCHLD, child_handler);
 924 }
 925
 926 static int set_reuse_addr(int sockfd)
 927 {
 928         int on = 1;
 929
 930         if (!reuseaddr)
 931                 return 0;
 932         return setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR,
 933                           &on, sizeof(on));
 934 }
 935
 936 struct socketlist {
 937         int *list;
 938         size_t nr;
 939         size_t alloc;
 940 };
 941
 942 static const char *ip2str(int family, struct sockaddr *sin, socklen_t len)
 943 {
 944 #ifdef NO_IPV6
 945         static char ip[INET_ADDRSTRLEN];
 946 #else
 947         static char ip[INET6_ADDRSTRLEN];
 948 #endif
 949
 950         switch (family) {
 951 #ifndef NO_IPV6
 952         case AF_INET6:
 953                 inet_ntop(family, &((struct sockaddr_in6*)sin)->sin6_addr, ip, len);
 954                 break;
 955 #endif
 956         case AF_INET:
 957                 inet_ntop(family, &((struct sockaddr_in*)sin)->sin_addr, ip, len);
 958                 break;
 959         default:
 960                 xsnprintf(ip, sizeof(ip), "<unknown>");
 961         }
 962         return ip;
 963 }
 964
 965 #ifndef NO_IPV6
 966
 967 static int setup_named_sock(char *listen_addr, int listen_port, struct socketlist *socklist)
 968 {
 969         int socknum = 0;
 970         char pbuf[NI_MAXSERV];
 971         struct addrinfo hints, *ai0, *ai;
 972         int gai;
 973         long flags;
 974
 975         xsnprintf(pbuf, sizeof(pbuf), "%d", listen_port);
 976         memset(&hints, 0, sizeof(hints));
 977         hints.ai_family = AF_UNSPEC;
 978         hints.ai_socktype = SOCK_STREAM;
 979         hints.ai_protocol = IPPROTO_TCP;
 980         hints.ai_flags = AI_PASSIVE;
 981
 982         gai = getaddrinfo(listen_addr, pbuf, &hints, &ai0);
 983         if (gai) {
 984                 logerror("getaddrinfo() for %s failed: %s", listen_addr, gai_strerror(gai));
 985                 return 0;
 986         }
 987
 988         for (ai = ai0; ai; ai = ai->ai_next) {
 989                 int sockfd;
 990
 991                 sockfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
 992                 if (sockfd < 0)
 993                         continue;
 994                 if (sockfd >= FD_SETSIZE) {
 995                         logerror("Socket descriptor too large");
 996                         close(sockfd);
 997                         continue;
 998                 }
 999
1000 #ifdef IPV6_V6ONLY
1001                 if (ai->ai_family == AF_INET6) {
1002                         int on = 1;
1003                         setsockopt(sockfd, IPPROTO_IPV6, IPV6_V6ONLY,
1004                                    &on, sizeof(on));
1005                         /* Note: error is not fatal */
1006                 }
1007 #endif
1008
1009                 if (set_reuse_addr(sockfd)) {
1010                         logerror("Could not set SO_REUSEADDR: %s", strerror(errno));
1011                         close(sockfd);
1012                         continue;
1013                 }
1014
1015                 set_keep_alive(sockfd);
1016
1017                 if (bind(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
1018                         logerror("Could not bind to %s: %s",
1019                                  ip2str(ai->ai_family, ai->ai_addr, ai->ai_addrlen),
1020                                  strerror(errno));
1021                         close(sockfd);
1022                         continue;       /* not fatal */
1023                 }
1024                 if (listen(sockfd, 5) < 0) {
1025                         logerror("Could not listen to %s: %s",
1026                                  ip2str(ai->ai_family, ai->ai_addr, ai->ai_addrlen),
1027                                  strerror(errno));
1028                         close(sockfd);
1029                         continue;       /* not fatal */
1030                 }
1031
1032                 flags = fcntl(sockfd, F_GETFD, 0);
1033                 if (flags >= 0)
1034                         fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
1035
1036                 ALLOC_GROW(socklist->list, socklist->nr + 1, socklist->alloc);
1037                 socklist->list[socklist->nr++] = sockfd;
1038                 socknum++;
1039         }
1040
1041         freeaddrinfo(ai0);
1042
1043         return socknum;
1044 }
1045
1046 #else /* NO_IPV6 */
1047
1048 static int setup_named_sock(char *listen_addr, int listen_port, struct socketlist *socklist)
1049 {
1050         struct sockaddr_in sin;
1051         int sockfd;
1052         long flags;
1053
1054         memset(&sin, 0, sizeof sin);
1055         sin.sin_family = AF_INET;
1056         sin.sin_port = htons(listen_port);
1057
1058         if (listen_addr) {
1059                 /* Well, host better be an IP address here. */
1060                 if (inet_pton(AF_INET, listen_addr, &sin.sin_addr.s_addr) <= 0)
1061                         return 0;
1062         } else {
1063                 sin.sin_addr.s_addr = htonl(INADDR_ANY);
1064         }
1065
1066         sockfd = socket(AF_INET, SOCK_STREAM, 0);
1067         if (sockfd < 0)
1068                 return 0;
1069
1070         if (set_reuse_addr(sockfd)) {
1071                 logerror("Could not set SO_REUSEADDR: %s", strerror(errno));
1072                 close(sockfd);
1073                 return 0;
1074         }
1075
1076         set_keep_alive(sockfd);
1077
1078         if ( bind(sockfd, (struct sockaddr *)&sin, sizeof sin) < 0 ) {
1079                 logerror("Could not bind to %s: %s",
1080                          ip2str(AF_INET, (struct sockaddr *)&sin, sizeof(sin)),
1081                          strerror(errno));
1082                 close(sockfd);
1083                 return 0;
1084         }
1085
1086         if (listen(sockfd, 5) < 0) {
1087                 logerror("Could not listen to %s: %s",
1088                          ip2str(AF_INET, (struct sockaddr *)&sin, sizeof(sin)),
1089                          strerror(errno));
1090                 close(sockfd);
1091                 return 0;
1092         }
1093
1094         flags = fcntl(sockfd, F_GETFD, 0);
1095         if (flags >= 0)
1096                 fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
1097
1098         ALLOC_GROW(socklist->list, socklist->nr + 1, socklist->alloc);
1099         socklist->list[socklist->nr++] = sockfd;
1100         return 1;
1101 }
1102
1103 #endif
1104
1105 static void socksetup(struct string_list *listen_addr, int listen_port, struct socketlist *socklist)
1106 {
1107         if (!listen_addr->nr)
1108                 setup_named_sock(NULL, listen_port, socklist);
1109         else {
1110                 int i, socknum;
1111                 for (i = 0; i < listen_addr->nr; i++) {
1112                         socknum = setup_named_sock(listen_addr->items[i].string,
1113                                                    listen_port, socklist);
1114
1115                         if (socknum == 0)
1116                                 logerror("unable to allocate any listen sockets for host %s on port %u",
1117                                          listen_addr->items[i].string, listen_port);
1118                 }
1119         }
1120 }
1121
1122 static int service_loop(struct socketlist *socklist)
1123 {
1124         struct pollfd *pfd;
1125         int i;
1126
1127         CALLOC_ARRAY(pfd, socklist->nr);
1128
1129         for (i = 0; i < socklist->nr; i++) {
1130                 pfd[i].fd = socklist->list[i];
1131                 pfd[i].events = POLLIN;
1132         }
1133
1134         signal(SIGCHLD, child_handler);
1135
1136         for (;;) {
1137                 int i;
1138
1139                 check_dead_children();
1140
1141                 if (poll(pfd, socklist->nr, -1) < 0) {
1142                         if (errno != EINTR) {
1143                                 logerror("Poll failed, resuming: %s",
1144                                       strerror(errno));
1145                                 sleep(1);
1146                         }
1147                         continue;
1148                 }
1149
1150                 for (i = 0; i < socklist->nr; i++) {
1151                         if (pfd[i].revents & POLLIN) {
1152                                 union {
1153                                         struct sockaddr sa;
1154                                         struct sockaddr_in sai;
1155 #ifndef NO_IPV6
1156                                         struct sockaddr_in6 sai6;
1157 #endif
1158                                 } ss;
1159                                 socklen_t sslen = sizeof(ss);
1160                                 int incoming = accept(pfd[i].fd, &ss.sa, &sslen);
1161                                 if (incoming < 0) {
1162                                         switch (errno) {
1163                                         case EAGAIN:
1164                                         case EINTR:
1165                                         case ECONNABORTED:
1166                                                 continue;
1167                                         default:
1168                                                 die_errno("accept returned");
1169                                         }
1170                                 }
1171                                 handle(incoming, &ss.sa, sslen);
1172                         }
1173                 }
1174         }
1175 }
1176
1177 #ifdef NO_POSIX_GOODIES
1178
1179 struct credentials;
1180
1181 static void drop_privileges(struct credentials *cred UNUSED)
1182 {
1183         /* nothing */
1184 }
1185
1186 static struct credentials *prepare_credentials(const char *user_name UNUSED,
1187                                                const char *group_name UNUSED)
1188 {
1189         die("--user not supported on this platform");
1190 }
1191
1192 #else
1193
1194 struct credentials {
1195         struct passwd *pass;
1196         gid_t gid;
1197 };
1198
1199 static void drop_privileges(struct credentials *cred)
1200 {
1201         if (cred && (initgroups(cred->pass->pw_name, cred->gid) ||
1202             setgid (cred->gid) || setuid(cred->pass->pw_uid)))
1203                 die("cannot drop privileges");
1204 }
1205
1206 static struct credentials *prepare_credentials(const char *user_name,
1207     const char *group_name)
1208 {
1209         static struct credentials c;
1210
1211         c.pass = getpwnam(user_name);
1212         if (!c.pass)
1213                 die("user not found - %s", user_name);
1214
1215         if (!group_name)
1216                 c.gid = c.pass->pw_gid;
1217         else {
1218                 struct group *group = getgrnam(group_name);
1219                 if (!group)
1220                         die("group not found - %s", group_name);
1221
1222                 c.gid = group->gr_gid;
1223         }
1224
1225         return &c;
1226 }
1227 #endif
1228
1229 static int serve(struct string_list *listen_addr, int listen_port,
1230     struct credentials *cred)
1231 {
1232         struct socketlist socklist = { NULL, 0, 0 };
1233
1234         socksetup(listen_addr, listen_port, &socklist);
1235         if (socklist.nr == 0)
1236                 die("unable to allocate any listen sockets on port %u",
1237                     listen_port);
1238
1239         drop_privileges(cred);
1240
1241         loginfo("Ready to rumble");
1242
1243         return service_loop(&socklist);
1244 }
1245
1246 int cmd_main(int argc, const char **argv)
1247 {
1248         int listen_port = 0;
1249         struct string_list listen_addr = STRING_LIST_INIT_DUP;
1250         int serve_mode = 0, inetd_mode = 0;
1251         const char *pid_file = NULL, *user_name = NULL, *group_name = NULL;
1252         int detach = 0;
1253         struct credentials *cred = NULL;
1254         int i;
1255         int ret;
1256
1257         for (i = 1; i < argc; i++) {
1258                 const char *arg = argv[i];
1259                 const char *v;
1260
1261                 if (skip_prefix(arg, "--listen=", &v)) {
1262                         string_list_append_nodup(&listen_addr, xstrdup_tolower(v));
1263                         continue;
1264                 }
1265                 if (skip_prefix(arg, "--port=", &v)) {
1266                         char *end;
1267                         unsigned long n;
1268                         n = strtoul(v, &end, 0);
1269                         if (*v && !*end) {
1270                                 listen_port = n;
1271                                 continue;
1272                         }
1273                 }
1274                 if (!strcmp(arg, "--serve")) {
1275                         serve_mode = 1;
1276                         continue;
1277                 }
1278                 if (!strcmp(arg, "--inetd")) {
1279                         inetd_mode = 1;
1280                         continue;
1281                 }
1282                 if (!strcmp(arg, "--verbose")) {
1283                         verbose = 1;
1284                         continue;
1285                 }
1286                 if (!strcmp(arg, "--syslog")) {
1287                         log_destination = LOG_DESTINATION_SYSLOG;
1288                         continue;
1289                 }
1290                 if (skip_prefix(arg, "--log-destination=", &v)) {
1291                         if (!strcmp(v, "syslog")) {
1292                                 log_destination = LOG_DESTINATION_SYSLOG;
1293                                 continue;
1294                         } else if (!strcmp(v, "stderr")) {
1295                                 log_destination = LOG_DESTINATION_STDERR;
1296                                 continue;
1297                         } else if (!strcmp(v, "none")) {
1298                                 log_destination = LOG_DESTINATION_NONE;
1299                                 continue;
1300                         } else
1301                                 die("unknown log destination '%s'", v);
1302                 }
1303                 if (!strcmp(arg, "--export-all")) {
1304                         export_all_trees = 1;
1305                         continue;
1306                 }
1307                 if (skip_prefix(arg, "--access-hook=", &v)) {
1308                         access_hook = v;
1309                         continue;
1310                 }
1311                 if (skip_prefix(arg, "--timeout=", &v)) {
1312                         if (strtoul_ui(v, 10, &timeout))
1313                                 die(_("invalid timeout '%s', expecting a non-negative integer"), v);
1314                         continue;
1315                 }
1316                 if (skip_prefix(arg, "--init-timeout=", &v)) {
1317                         if (strtoul_ui(v, 10, &init_timeout))
1318                                 die(_("invalid init-timeout '%s', expecting a non-negative integer"), v);
1319                         continue;
1320                 }
1321                 if (skip_prefix(arg, "--max-connections=", &v)) {
1322                         if (strtol_i(v, 10, &max_connections))
1323                                 die(_("invalid max-connections '%s', expecting an integer"), v);
1324                         if (max_connections < 0)
1325                                 max_connections = 0;  /* unlimited */
1326                         continue;
1327                 }
1328                 if (!strcmp(arg, "--strict-paths")) {
1329                         strict_paths = 1;
1330                         continue;
1331                 }
1332                 if (skip_prefix(arg, "--base-path=", &v)) {
1333                         base_path = v;
1334                         continue;
1335                 }
1336                 if (!strcmp(arg, "--base-path-relaxed")) {
1337                         base_path_relaxed = 1;
1338                         continue;
1339                 }
1340                 if (skip_prefix(arg, "--interpolated-path=", &v)) {
1341                         interpolated_path = v;
1342                         continue;
1343                 }
1344                 if (!strcmp(arg, "--reuseaddr")) {
1345                         reuseaddr = 1;
1346                         continue;
1347                 }
1348                 if (!strcmp(arg, "--user-path")) {
1349                         user_path = "";
1350                         continue;
1351                 }
1352                 if (skip_prefix(arg, "--user-path=", &v)) {
1353                         user_path = v;
1354                         continue;
1355                 }
1356                 if (skip_prefix(arg, "--pid-file=", &v)) {
1357                         pid_file = v;
1358                         continue;
1359                 }
1360                 if (!strcmp(arg, "--detach")) {
1361                         detach = 1;
1362                         continue;
1363                 }
1364                 if (skip_prefix(arg, "--user=", &v)) {
1365                         user_name = v;
1366                         continue;
1367                 }
1368                 if (skip_prefix(arg, "--group=", &v)) {
1369                         group_name = v;
1370                         continue;
1371                 }
1372                 if (skip_prefix(arg, "--enable=", &v)) {
1373                         enable_service(v, 1);
1374                         continue;
1375                 }
1376                 if (skip_prefix(arg, "--disable=", &v)) {
1377                         enable_service(v, 0);
1378                         continue;
1379                 }
1380                 if (skip_prefix(arg, "--allow-override=", &v)) {
1381                         make_service_overridable(v, 1);
1382                         continue;
1383                 }
1384                 if (skip_prefix(arg, "--forbid-override=", &v)) {
1385                         make_service_overridable(v, 0);
1386                         continue;
1387                 }
1388                 if (!strcmp(arg, "--informative-errors")) {
1389                         informative_errors = 1;
1390                         continue;
1391                 }
1392                 if (!strcmp(arg, "--no-informative-errors")) {
1393                         informative_errors = 0;
1394                         continue;
1395                 }
1396                 if (!strcmp(arg, "--")) {
1397                         ok_paths = &argv[i+1];
1398                         break;
1399                 } else if (arg[0] != '-') {
1400                         ok_paths = &argv[i];
1401                         break;
1402                 }
1403
1404                 usage(daemon_usage);
1405         }
1406
1407         if (log_destination == LOG_DESTINATION_UNSET) {
1408                 if (inetd_mode || detach)
1409                         log_destination = LOG_DESTINATION_SYSLOG;
1410                 else
1411                         log_destination = LOG_DESTINATION_STDERR;
1412         }
1413
1414         if (log_destination == LOG_DESTINATION_SYSLOG) {
1415                 openlog("git-daemon", LOG_PID, LOG_DAEMON);
1416                 set_die_routine(daemon_die);
1417         } else
1418                 /* avoid splitting a message in the middle */
1419                 setvbuf(stderr, NULL, _IOFBF, 4096);
1420
1421         if (inetd_mode && (detach || group_name || user_name))
1422                 die("--detach, --user and --group are incompatible with --inetd");
1423
1424         if (inetd_mode && (listen_port || (listen_addr.nr > 0)))
1425                 die("--listen= and --port= are incompatible with --inetd");
1426         else if (listen_port == 0)
1427                 listen_port = DEFAULT_GIT_PORT;
1428
1429         if (group_name && !user_name)
1430                 die("--group supplied without --user");
1431
1432         if (user_name)
1433                 cred = prepare_credentials(user_name, group_name);
1434
1435         if (strict_paths && (!ok_paths || !*ok_paths))
1436                 die("option --strict-paths requires '<directory>' arguments");
1437
1438         if (base_path && !is_directory(base_path))
1439                 die("base-path '%s' does not exist or is not a directory",
1440                     base_path);
1441
1442         if (log_destination != LOG_DESTINATION_STDERR) {
1443                 if (!freopen("/dev/null", "w", stderr))
1444                         die_errno("failed to redirect stderr to /dev/null");
1445         }
1446
1447         if (inetd_mode || serve_mode) {
1448                 ret = execute();
1449         } else {
1450                 if (detach) {
1451                         if (daemonize())
1452                                 die("--detach not supported on this platform");
1453                 }
1454
1455                 if (pid_file)
1456                         write_file(pid_file, "%"PRIuMAX, (uintmax_t) getpid());
1457
1458                 /* prepare argv for serving-processes */
1459                 strvec_push(&cld_argv, argv[0]); /* git-daemon */
1460                 strvec_push(&cld_argv, "--serve");
1461                 for (i = 1; i < argc; ++i)
1462                         strvec_push(&cld_argv, argv[i]);
1463
1464                 ret = serve(&listen_addr, listen_port, cred);
1465         }
1466
1467         string_list_clear(&listen_addr, 0);
1468         return ret;
1469 }