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         unsigned enter_repo_flags;
 156
 157         dir = directory;
 158
 159         if (daemon_avoid_alias(dir)) {
 160                 logerror("'%s': aliased", dir);
 161                 return NULL;
 162         }
 163
 164         if (*dir == '~') {
 165                 if (!user_path) {
 166                         logerror("'%s': User-path not allowed", dir);
 167                         return NULL;
 168                 }
 169                 if (*user_path) {
 170                         /* Got either "~alice" or "~alice/foo";
 171                          * rewrite them to "~alice/%s" or
 172                          * "~alice/%s/foo".
 173                          */
 174                         int namlen, restlen = strlen(dir);
 175                         const char *slash = strchr(dir, '/');
 176                         if (!slash)
 177                                 slash = dir + restlen;
 178                         namlen = slash - dir;
 179                         restlen -= namlen;
 180                         loginfo("userpath <%s>, request <%s>, namlen %d, restlen %d, slash <%s>", user_path, dir, namlen, restlen, slash);
 181                         rlen = snprintf(rpath, sizeof(rpath), "%.*s/%s%.*s",
 182                                         namlen, dir, user_path, restlen, slash);
 183                         if (rlen >= sizeof(rpath)) {
 184                                 logerror("user-path too large: %s", rpath);
 185                                 return NULL;
 186                         }
 187                         dir = rpath;
 188                 }
 189         }
 190         else if (interpolated_path && hi->saw_extended_args) {
 191                 struct strbuf expanded_path = STRBUF_INIT;
 192                 const char *format = interpolated_path;
 193
 194                 if (*dir != '/') {
 195                         /* Allow only absolute */
 196                         logerror("'%s': Non-absolute path denied (interpolated-path active)", dir);
 197                         return NULL;
 198                 }
 199
 200                 while (strbuf_expand_step(&expanded_path, &format)) {
 201                         if (skip_prefix(format, "%", &format))
 202                                 strbuf_addch(&expanded_path, '%');
 203                         else if (skip_prefix(format, "H", &format))
 204                                 strbuf_addbuf(&expanded_path, &hi->hostname);
 205                         else if (skip_prefix(format, "CH", &format))
 206                                 strbuf_addstr(&expanded_path,
 207                                               get_canon_hostname(hi));
 208                         else if (skip_prefix(format, "IP", &format))
 209                                 strbuf_addstr(&expanded_path,
 210                                               get_ip_address(hi));
 211                         else if (skip_prefix(format, "P", &format))
 212                                 strbuf_addbuf(&expanded_path, &hi->tcp_port);
 213                         else if (skip_prefix(format, "D", &format))
 214                                 strbuf_addstr(&expanded_path, directory);
 215                         else
 216                                 strbuf_addch(&expanded_path, '%');
 217                 }
 218
 219                 rlen = strlcpy(interp_path, expanded_path.buf,
 220                                sizeof(interp_path));
 221                 strbuf_release(&expanded_path);
 222                 if (rlen >= sizeof(interp_path)) {
 223                         logerror("interpolated path too large: %s",
 224                                  interp_path);
 225                         return NULL;
 226                 }
 227
 228                 loginfo("Interpolated dir '%s'", interp_path);
 229
 230                 dir = interp_path;
 231         }
 232         else if (base_path) {
 233                 if (*dir != '/') {
 234                         /* Allow only absolute */
 235                         logerror("'%s': Non-absolute path denied (base-path active)", dir);
 236                         return NULL;
 237                 }
 238                 rlen = snprintf(rpath, sizeof(rpath), "%s%s", base_path, dir);
 239                 if (rlen >= sizeof(rpath)) {
 240                         logerror("base-path too large: %s", rpath);
 241                         return NULL;
 242                 }
 243                 dir = rpath;
 244         }
 245
 246         enter_repo_flags = strict_paths ? ENTER_REPO_STRICT : 0;
 247         path = enter_repo(dir, enter_repo_flags);
 248         if (!path && base_path && base_path_relaxed) {
 249                 /*
 250                  * if we fail and base_path_relaxed is enabled, try without
 251                  * prefixing the base path
 252                  */
 253                 dir = directory;
 254                 path = enter_repo(dir, enter_repo_flags);
 255         }
 256
 257         if (!path) {
 258                 logerror("'%s' does not appear to be a git repository", dir);
 259                 return NULL;
 260         }
 261
 262         if ( ok_paths && *ok_paths ) {
 263                 const char **pp;
 264                 int pathlen = strlen(path);
 265
 266                 /* The validation is done on the paths after enter_repo
 267                  * appends optional {.git,.git/.git} and friends, but
 268                  * it does not use getcwd().  So if your /pub is
 269                  * a symlink to /mnt/pub, you can include /pub and
 270                  * do not have to say /mnt/pub.
 271                  * Do not say /pub/.
 272                  */
 273                 for ( pp = ok_paths ; *pp ; pp++ ) {
 274                         int len = strlen(*pp);
 275                         if (len <= pathlen &&
 276                             !memcmp(*pp, path, len) &&
 277                             (path[len] == '\0' ||
 278                              (!strict_paths && path[len] == '/')))
 279                                 return path;
 280                 }
 281         }
 282         else {
 283                 /* be backwards compatible */
 284                 if (!strict_paths)
 285                         return path;
 286         }
 287
 288         logerror("'%s': not in directory list", path);
 289         return NULL;            /* Fallthrough. Deny by default */
 290 }
 291
 292 typedef int (*daemon_service_fn)(const struct strvec *env);
 293 struct daemon_service {
 294         const char *name;
 295         const char *config_name;
 296         daemon_service_fn fn;
 297         int enabled;
 298         int overridable;
 299 };
 300
 301 static int daemon_error(const char *dir, const char *msg)
 302 {
 303         if (!informative_errors)
 304                 msg = "access denied or repository not exported";
 305         packet_write_fmt(1, "ERR %s: %s", msg, dir);
 306         return -1;
 307 }
 308
 309 static const char *access_hook;
 310
 311 static int run_access_hook(struct daemon_service *service, const char *dir,
 312                            const char *path, struct hostinfo *hi)
 313 {
 314         struct child_process child = CHILD_PROCESS_INIT;
 315         struct strbuf buf = STRBUF_INIT;
 316         char *eol;
 317         int seen_errors = 0;
 318
 319         strvec_push(&child.args, access_hook);
 320         strvec_push(&child.args, service->name);
 321         strvec_push(&child.args, path);
 322         strvec_push(&child.args, hi->hostname.buf);
 323         strvec_push(&child.args, get_canon_hostname(hi));
 324         strvec_push(&child.args, get_ip_address(hi));
 325         strvec_push(&child.args, hi->tcp_port.buf);
 326
 327         child.use_shell = 1;
 328         child.no_stdin = 1;
 329         child.no_stderr = 1;
 330         child.out = -1;
 331         if (start_command(&child)) {
 332                 logerror("daemon access hook '%s' failed to start",
 333                          access_hook);
 334                 goto error_return;
 335         }
 336         if (strbuf_read(&buf, child.out, 0) < 0) {
 337                 logerror("failed to read from pipe to daemon access hook '%s'",
 338                          access_hook);
 339                 strbuf_reset(&buf);
 340                 seen_errors = 1;
 341         }
 342         if (close(child.out) < 0) {
 343                 logerror("failed to close pipe to daemon access hook '%s'",
 344                          access_hook);
 345                 seen_errors = 1;
 346         }
 347         if (finish_command(&child))
 348                 seen_errors = 1;
 349
 350         if (!seen_errors) {
 351                 strbuf_release(&buf);
 352                 return 0;
 353         }
 354
 355 error_return:
 356         strbuf_ltrim(&buf);
 357         if (!buf.len)
 358                 strbuf_addstr(&buf, "service rejected");
 359         eol = strchr(buf.buf, '\n');
 360         if (eol)
 361                 *eol = '\0';
 362         errno = EACCES;
 363         daemon_error(dir, buf.buf);
 364         strbuf_release(&buf);
 365         return -1;
 366 }
 367
 368 static int run_service(const char *dir, struct daemon_service *service,
 369                        struct hostinfo *hi, const struct strvec *env)
 370 {
 371         const char *path;
 372         int enabled = service->enabled;
 373         struct strbuf var = STRBUF_INIT;
 374
 375         loginfo("Request %s for '%s'", service->name, dir);
 376
 377         if (!enabled && !service->overridable) {
 378                 logerror("'%s': service not enabled.", service->name);
 379                 errno = EACCES;
 380                 return daemon_error(dir, "service not enabled");
 381         }
 382
 383         if (!(path = path_ok(dir, hi)))
 384                 return daemon_error(dir, "no such repository");
 385
 386         /*
 387          * Security on the cheap.
 388          *
 389          * We want a readable HEAD, usable "objects" directory, and
 390          * a "git-daemon-export-ok" flag that says that the other side
 391          * is ok with us doing this.
 392          *
 393          * path_ok() uses enter_repo() and checks for included directories.
 394          * We only need to make sure the repository is exported.
 395          */
 396
 397         if (!export_all_trees && access("git-daemon-export-ok", F_OK)) {
 398                 logerror("'%s': repository not exported.", path);
 399                 errno = EACCES;
 400                 return daemon_error(dir, "repository not exported");
 401         }
 402
 403         if (service->overridable) {
 404                 strbuf_addf(&var, "daemon.%s", service->config_name);
 405                 git_config_get_bool(var.buf, &enabled);
 406                 strbuf_release(&var);
 407         }
 408         if (!enabled) {
 409                 logerror("'%s': service not enabled for '%s'",
 410                          service->name, path);
 411                 errno = EACCES;
 412                 return daemon_error(dir, "service not enabled");
 413         }
 414
 415         /*
 416          * Optionally, a hook can choose to deny access to the
 417          * repository depending on the phase of the moon.
 418          */
 419         if (access_hook && run_access_hook(service, dir, path, hi))
 420                 return -1;
 421
 422         /*
 423          * We'll ignore SIGTERM from now on, we have a
 424          * good client.
 425          */
 426         signal(SIGTERM, SIG_IGN);
 427
 428         return service->fn(env);
 429 }
 430
 431 static void copy_to_log(int fd)
 432 {
 433         struct strbuf line = STRBUF_INIT;
 434         FILE *fp;
 435
 436         fp = fdopen(fd, "r");
 437         if (!fp) {
 438                 logerror("fdopen of error channel failed");
 439                 close(fd);
 440                 return;
 441         }
 442
 443         while (strbuf_getline_lf(&line, fp) != EOF) {
 444                 logerror("%s", line.buf);
 445                 strbuf_setlen(&line, 0);
 446         }
 447
 448         strbuf_release(&line);
 449         fclose(fp);
 450 }
 451
 452 static int run_service_command(struct child_process *cld)
 453 {
 454         strvec_push(&cld->args, ".");
 455         cld->git_cmd = 1;
 456         cld->err = -1;
 457         if (start_command(cld))
 458                 return -1;
 459
 460         close(0);
 461         close(1);
 462
 463         copy_to_log(cld->err);
 464
 465         return finish_command(cld);
 466 }
 467
 468 static int upload_pack(const struct strvec *env)
 469 {
 470         struct child_process cld = CHILD_PROCESS_INIT;
 471         strvec_pushl(&cld.args, "upload-pack", "--strict", NULL);
 472         strvec_pushf(&cld.args, "--timeout=%u", timeout);
 473
 474         strvec_pushv(&cld.env, env->v);
 475
 476         return run_service_command(&cld);
 477 }
 478
 479 static int upload_archive(const struct strvec *env)
 480 {
 481         struct child_process cld = CHILD_PROCESS_INIT;
 482         strvec_push(&cld.args, "upload-archive");
 483
 484         strvec_pushv(&cld.env, env->v);
 485
 486         return run_service_command(&cld);
 487 }
 488
 489 static int receive_pack(const struct strvec *env)
 490 {
 491         struct child_process cld = CHILD_PROCESS_INIT;
 492         strvec_push(&cld.args, "receive-pack");
 493
 494         strvec_pushv(&cld.env, env->v);
 495
 496         return run_service_command(&cld);
 497 }
 498
 499 static struct daemon_service daemon_service[] = {
 500         { "upload-archive", "uploadarch", upload_archive, 0, 1 },
 501         { "upload-pack", "uploadpack", upload_pack, 1, 1 },
 502         { "receive-pack", "receivepack", receive_pack, 0, 1 },
 503 };
 504
 505 static void enable_service(const char *name, int ena)
 506 {
 507         for (size_t i = 0; i < ARRAY_SIZE(daemon_service); i++) {
 508                 if (!strcmp(daemon_service[i].name, name)) {
 509                         daemon_service[i].enabled = ena;
 510                         return;
 511                 }
 512         }
 513         die("No such service %s", name);
 514 }
 515
 516 static void make_service_overridable(const char *name, int ena)
 517 {
 518         for (size_t 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;
 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 (size_t 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 unsigned int max_connections = 32;
 806 static unsigned int live_children;
 807
 808 static struct child {
 809         struct child *next;
 810         struct child_process cld;
 811         struct sockaddr_storage address;
 812 } *firstborn;
 813
 814 static void add_child(struct child_process *cld, struct sockaddr *addr, socklen_t addrlen)
 815 {
 816         struct child *newborn, **cradle;
 817
 818         CALLOC_ARRAY(newborn, 1);
 819         live_children++;
 820         memcpy(&newborn->cld, cld, sizeof(*cld));
 821         memcpy(&newborn->address, addr, addrlen);
 822         for (cradle = &firstborn; *cradle; cradle = &(*cradle)->next)
 823                 if (!addrcmp(&(*cradle)->address, &newborn->address))
 824                         break;
 825         newborn->next = *cradle;
 826         *cradle = newborn;
 827 }
 828
 829 /*
 830  * This gets called if the number of connections grows
 831  * past "max_connections".
 832  *
 833  * We kill the newest connection from a duplicate IP.
 834  */
 835 static void kill_some_child(void)
 836 {
 837         const struct child *blanket, *next;
 838
 839         if (!(blanket = firstborn))
 840                 return;
 841
 842         for (; (next = blanket->next); blanket = next)
 843                 if (!addrcmp(&blanket->address, &next->address)) {
 844                         kill(blanket->cld.pid, SIGTERM);
 845                         break;
 846                 }
 847 }
 848
 849 static void check_dead_children(void)
 850 {
 851         int status;
 852         pid_t pid;
 853
 854         struct child **cradle, *blanket;
 855         for (cradle = &firstborn; (blanket = *cradle);)
 856                 if ((pid = waitpid(blanket->cld.pid, &status, WNOHANG)) > 1) {
 857                         const char *dead = "";
 858                         if (status)
 859                                 dead = " (with error)";
 860                         loginfo("[%"PRIuMAX"] Disconnected%s", (uintmax_t)pid, dead);
 861
 862                         /* remove the child */
 863                         *cradle = blanket->next;
 864                         live_children--;
 865                         child_process_clear(&blanket->cld);
 866                         free(blanket);
 867                 } else
 868                         cradle = &blanket->next;
 869 }
 870
 871 static struct strvec cld_argv = STRVEC_INIT;
 872 static void handle(int incoming, struct sockaddr *addr, socklen_t addrlen)
 873 {
 874         struct child_process cld = CHILD_PROCESS_INIT;
 875
 876         if (max_connections && live_children >= max_connections) {
 877                 kill_some_child();
 878                 sleep(1);  /* give it some time to die */
 879                 check_dead_children();
 880                 if (live_children >= max_connections) {
 881                         close(incoming);
 882                         logerror("Too many children, dropping connection");
 883                         return;
 884                 }
 885         }
 886
 887         if (addr->sa_family == AF_INET) {
 888                 char buf[128] = "";
 889                 struct sockaddr_in *sin_addr = (void *) addr;
 890                 inet_ntop(addr->sa_family, &sin_addr->sin_addr, buf, sizeof(buf));
 891                 strvec_pushf(&cld.env, "REMOTE_ADDR=%s", buf);
 892                 strvec_pushf(&cld.env, "REMOTE_PORT=%d",
 893                              ntohs(sin_addr->sin_port));
 894 #ifndef NO_IPV6
 895         } else if (addr->sa_family == AF_INET6) {
 896                 char buf[128] = "";
 897                 struct sockaddr_in6 *sin6_addr = (void *) addr;
 898                 inet_ntop(AF_INET6, &sin6_addr->sin6_addr, buf, sizeof(buf));
 899                 strvec_pushf(&cld.env, "REMOTE_ADDR=[%s]", buf);
 900                 strvec_pushf(&cld.env, "REMOTE_PORT=%d",
 901                              ntohs(sin6_addr->sin6_port));
 902 #endif
 903         }
 904
 905         strvec_pushv(&cld.args, cld_argv.v);
 906         cld.in = incoming;
 907         cld.out = dup(incoming);
 908
 909         if (start_command(&cld))
 910                 logerror("unable to fork");
 911         else
 912                 add_child(&cld, addr, addrlen);
 913 }
 914
 915 static void child_handler(int signo UNUSED)
 916 {
 917         /*
 918          * Otherwise empty handler because systemcalls should get interrupted
 919          * upon signal receipt.
 920          */
 921 }
 922
 923 static int set_reuse_addr(int sockfd)
 924 {
 925         int on = 1;
 926
 927         if (!reuseaddr)
 928                 return 0;
 929         return setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR,
 930                           &on, sizeof(on));
 931 }
 932
 933 struct socketlist {
 934         int *list;
 935         size_t nr;
 936         size_t alloc;
 937 };
 938
 939 static const char *ip2str(int family, struct sockaddr *sin, socklen_t len)
 940 {
 941 #ifdef NO_IPV6
 942         static char ip[INET_ADDRSTRLEN];
 943 #else
 944         static char ip[INET6_ADDRSTRLEN];
 945 #endif
 946
 947         switch (family) {
 948 #ifndef NO_IPV6
 949         case AF_INET6:
 950                 inet_ntop(family, &((struct sockaddr_in6*)sin)->sin6_addr, ip, len);
 951                 break;
 952 #endif
 953         case AF_INET:
 954                 inet_ntop(family, &((struct sockaddr_in*)sin)->sin_addr, ip, len);
 955                 break;
 956         default:
 957                 xsnprintf(ip, sizeof(ip), "<unknown>");
 958         }
 959         return ip;
 960 }
 961
 962 #ifndef NO_IPV6
 963
 964 static int setup_named_sock(char *listen_addr, int listen_port, struct socketlist *socklist)
 965 {
 966         int socknum = 0;
 967         char pbuf[NI_MAXSERV];
 968         struct addrinfo hints, *ai0, *ai;
 969         int gai;
 970         long flags;
 971
 972         xsnprintf(pbuf, sizeof(pbuf), "%d", listen_port);
 973         memset(&hints, 0, sizeof(hints));
 974         hints.ai_family = AF_UNSPEC;
 975         hints.ai_socktype = SOCK_STREAM;
 976         hints.ai_protocol = IPPROTO_TCP;
 977         hints.ai_flags = AI_PASSIVE;
 978
 979         gai = getaddrinfo(listen_addr, pbuf, &hints, &ai0);
 980         if (gai) {
 981                 logerror("getaddrinfo() for %s failed: %s", listen_addr, gai_strerror(gai));
 982                 return 0;
 983         }
 984
 985         for (ai = ai0; ai; ai = ai->ai_next) {
 986                 int sockfd;
 987
 988                 sockfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
 989                 if (sockfd < 0)
 990                         continue;
 991
 992 #ifdef IPV6_V6ONLY
 993                 if (ai->ai_family == AF_INET6) {
 994                         int on = 1;
 995                         setsockopt(sockfd, IPPROTO_IPV6, IPV6_V6ONLY,
 996                                    &on, sizeof(on));
 997                         /* Note: error is not fatal */
 998                 }
 999 #endif
1000
1001                 if (set_reuse_addr(sockfd)) {
1002                         logerror("Could not set SO_REUSEADDR: %s", strerror(errno));
1003                         close(sockfd);
1004                         continue;
1005                 }
1006
1007                 set_keep_alive(sockfd);
1008
1009                 if (bind(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
1010                         logerror("Could not bind to %s: %s",
1011                                  ip2str(ai->ai_family, ai->ai_addr, ai->ai_addrlen),
1012                                  strerror(errno));
1013                         close(sockfd);
1014                         continue;       /* not fatal */
1015                 }
1016                 if (listen(sockfd, 5) < 0) {
1017                         logerror("Could not listen to %s: %s",
1018                                  ip2str(ai->ai_family, ai->ai_addr, ai->ai_addrlen),
1019                                  strerror(errno));
1020                         close(sockfd);
1021                         continue;       /* not fatal */
1022                 }
1023
1024                 flags = fcntl(sockfd, F_GETFD, 0);
1025                 if (flags >= 0)
1026                         fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
1027
1028                 ALLOC_GROW(socklist->list, socklist->nr + 1, socklist->alloc);
1029                 socklist->list[socklist->nr++] = sockfd;
1030                 socknum++;
1031         }
1032
1033         freeaddrinfo(ai0);
1034
1035         return socknum;
1036 }
1037
1038 #else /* NO_IPV6 */
1039
1040 static int setup_named_sock(char *listen_addr, int listen_port, struct socketlist *socklist)
1041 {
1042         struct sockaddr_in sin;
1043         int sockfd;
1044         long flags;
1045
1046         memset(&sin, 0, sizeof sin);
1047         sin.sin_family = AF_INET;
1048         sin.sin_port = htons(listen_port);
1049
1050         if (listen_addr) {
1051                 /* Well, host better be an IP address here. */
1052                 if (inet_pton(AF_INET, listen_addr, &sin.sin_addr.s_addr) <= 0)
1053                         return 0;
1054         } else {
1055                 sin.sin_addr.s_addr = htonl(INADDR_ANY);
1056         }
1057
1058         sockfd = socket(AF_INET, SOCK_STREAM, 0);
1059         if (sockfd < 0)
1060                 return 0;
1061
1062         if (set_reuse_addr(sockfd)) {
1063                 logerror("Could not set SO_REUSEADDR: %s", strerror(errno));
1064                 close(sockfd);
1065                 return 0;
1066         }
1067
1068         set_keep_alive(sockfd);
1069
1070         if ( bind(sockfd, (struct sockaddr *)&sin, sizeof sin) < 0 ) {
1071                 logerror("Could not bind to %s: %s",
1072                          ip2str(AF_INET, (struct sockaddr *)&sin, sizeof(sin)),
1073                          strerror(errno));
1074                 close(sockfd);
1075                 return 0;
1076         }
1077
1078         if (listen(sockfd, 5) < 0) {
1079                 logerror("Could not listen to %s: %s",
1080                          ip2str(AF_INET, (struct sockaddr *)&sin, sizeof(sin)),
1081                          strerror(errno));
1082                 close(sockfd);
1083                 return 0;
1084         }
1085
1086         flags = fcntl(sockfd, F_GETFD, 0);
1087         if (flags >= 0)
1088                 fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
1089
1090         ALLOC_GROW(socklist->list, socklist->nr + 1, socklist->alloc);
1091         socklist->list[socklist->nr++] = sockfd;
1092         return 1;
1093 }
1094
1095 #endif
1096
1097 static void socksetup(struct string_list *listen_addr, int listen_port, struct socketlist *socklist)
1098 {
1099         if (!listen_addr->nr)
1100                 setup_named_sock(NULL, listen_port, socklist);
1101         else {
1102                 int socknum;
1103                 for (size_t i = 0; i < listen_addr->nr; i++) {
1104                         socknum = setup_named_sock(listen_addr->items[i].string,
1105                                                    listen_port, socklist);
1106
1107                         if (socknum == 0)
1108                                 logerror("unable to allocate any listen sockets for host %s on port %u",
1109                                          listen_addr->items[i].string, listen_port);
1110                 }
1111         }
1112 }
1113
1114 static int service_loop(struct socketlist *socklist)
1115 {
1116         struct sigaction sa;
1117         struct pollfd *pfd;
1118
1119         CALLOC_ARRAY(pfd, socklist->nr);
1120
1121         for (size_t i = 0; i < socklist->nr; i++) {
1122                 pfd[i].fd = socklist->list[i];
1123                 pfd[i].events = POLLIN;
1124         }
1125
1126         sigemptyset(&sa.sa_mask);
1127         sa.sa_flags = SA_NOCLDSTOP;
1128         sa.sa_handler = child_handler;
1129         sigaction(SIGCHLD, &sa, NULL);
1130
1131         for (;;) {
1132                 check_dead_children();
1133
1134                 if (poll(pfd, socklist->nr, -1) < 0) {
1135                         if (errno != EINTR) {
1136                                 logerror("Poll failed, resuming: %s",
1137                                       strerror(errno));
1138                                 sleep(1);
1139                         }
1140                         continue;
1141                 }
1142
1143                 for (size_t i = 0; i < socklist->nr; i++) {
1144                         if (pfd[i].revents & POLLIN) {
1145                                 union {
1146                                         struct sockaddr sa;
1147                                         struct sockaddr_in sai;
1148 #ifndef NO_IPV6
1149                                         struct sockaddr_in6 sai6;
1150 #endif
1151                                 } ss;
1152                                 socklen_t sslen = sizeof(ss);
1153                                 int incoming;
1154                                 int retry = 3;
1155
1156                         redo:
1157                                 incoming = accept(pfd[i].fd, &ss.sa, &sslen);
1158                                 if (incoming < 0) {
1159                                         switch (errno) {
1160                                         case EINTR:
1161                                                 if (--retry)
1162                                                         goto redo;
1163
1164                                                 /* fallthrough */
1165                                         case EAGAIN:
1166                                         case ECONNABORTED:
1167                                                 continue;
1168                                         default:
1169                                                 die_errno("accept returned");
1170                                         }
1171                                 }
1172                                 handle(incoming, &ss.sa, sslen);
1173                         }
1174                 }
1175         }
1176 }
1177
1178 #ifdef NO_POSIX_GOODIES
1179
1180 struct credentials;
1181
1182 static void drop_privileges(struct credentials *cred UNUSED)
1183 {
1184         /* nothing */
1185 }
1186
1187 static struct credentials *prepare_credentials(const char *user_name UNUSED,
1188                                                const char *group_name UNUSED)
1189 {
1190         die("--user not supported on this platform");
1191 }
1192
1193 #else
1194
1195 struct credentials {
1196         struct passwd *pass;
1197         gid_t gid;
1198 };
1199
1200 static void drop_privileges(struct credentials *cred)
1201 {
1202         if (cred && (initgroups(cred->pass->pw_name, cred->gid) ||
1203             setgid (cred->gid) || setuid(cred->pass->pw_uid)))
1204                 die("cannot drop privileges");
1205 }
1206
1207 static struct credentials *prepare_credentials(const char *user_name,
1208     const char *group_name)
1209 {
1210         static struct credentials c;
1211
1212         c.pass = getpwnam(user_name);
1213         if (!c.pass)
1214                 die("user not found - %s", user_name);
1215
1216         if (!group_name)
1217                 c.gid = c.pass->pw_gid;
1218         else {
1219                 struct group *group = getgrnam(group_name);
1220                 if (!group)
1221                         die("group not found - %s", group_name);
1222
1223                 c.gid = group->gr_gid;
1224         }
1225
1226         return &c;
1227 }
1228 #endif
1229
1230 static int serve(struct string_list *listen_addr, int listen_port,
1231     struct credentials *cred)
1232 {
1233         struct socketlist socklist = { NULL, 0, 0 };
1234
1235         socksetup(listen_addr, listen_port, &socklist);
1236         if (socklist.nr == 0)
1237                 die("unable to allocate any listen sockets on port %u",
1238                     listen_port);
1239
1240         drop_privileges(cred);
1241
1242         loginfo("Ready to rumble");
1243
1244         return service_loop(&socklist);
1245 }
1246
1247 int cmd_main(int argc, const char **argv)
1248 {
1249         int listen_port = 0;
1250         struct string_list listen_addr = STRING_LIST_INIT_DUP;
1251         int serve_mode = 0, inetd_mode = 0;
1252         const char *pid_file = NULL, *user_name = NULL, *group_name = NULL;
1253         int detach = 0;
1254         struct credentials *cred = NULL;
1255         int i;
1256         int ret;
1257
1258         for (i = 1; i < argc; i++) {
1259                 const char *arg = argv[i];
1260                 const char *v;
1261
1262                 if (skip_prefix(arg, "--listen=", &v)) {
1263                         string_list_append_nodup(&listen_addr, xstrdup_tolower(v));
1264                         continue;
1265                 }
1266                 if (skip_prefix(arg, "--port=", &v)) {
1267                         char *end;
1268                         unsigned long n;
1269                         n = strtoul(v, &end, 0);
1270                         if (*v && !*end) {
1271                                 listen_port = n;
1272                                 continue;
1273                         }
1274                 }
1275                 if (!strcmp(arg, "--serve")) {
1276                         serve_mode = 1;
1277                         continue;
1278                 }
1279                 if (!strcmp(arg, "--inetd")) {
1280                         inetd_mode = 1;
1281                         continue;
1282                 }
1283                 if (!strcmp(arg, "--verbose")) {
1284                         verbose = 1;
1285                         continue;
1286                 }
1287                 if (!strcmp(arg, "--syslog")) {
1288                         log_destination = LOG_DESTINATION_SYSLOG;
1289                         continue;
1290                 }
1291                 if (skip_prefix(arg, "--log-destination=", &v)) {
1292                         if (!strcmp(v, "syslog")) {
1293                                 log_destination = LOG_DESTINATION_SYSLOG;
1294                                 continue;
1295                         } else if (!strcmp(v, "stderr")) {
1296                                 log_destination = LOG_DESTINATION_STDERR;
1297                                 continue;
1298                         } else if (!strcmp(v, "none")) {
1299                                 log_destination = LOG_DESTINATION_NONE;
1300                                 continue;
1301                         } else
1302                                 die("unknown log destination '%s'", v);
1303                 }
1304                 if (!strcmp(arg, "--export-all")) {
1305                         export_all_trees = 1;
1306                         continue;
1307                 }
1308                 if (skip_prefix(arg, "--access-hook=", &v)) {
1309                         access_hook = v;
1310                         continue;
1311                 }
1312                 if (skip_prefix(arg, "--timeout=", &v)) {
1313                         if (strtoul_ui(v, 10, &timeout))
1314                                 die(_("invalid timeout '%s', expecting a non-negative integer"), v);
1315                         continue;
1316                 }
1317                 if (skip_prefix(arg, "--init-timeout=", &v)) {
1318                         if (strtoul_ui(v, 10, &init_timeout))
1319                                 die(_("invalid init-timeout '%s', expecting a non-negative integer"), v);
1320                         continue;
1321                 }
1322                 if (skip_prefix(arg, "--max-connections=", &v)) {
1323                         int parsed_value;
1324                         if (strtol_i(v, 10, &parsed_value))
1325                                 die(_("invalid max-connections '%s', expecting an integer"), v);
1326                         /* A negative value indicates unlimited children. */
1327                         max_connections = parsed_value < 0 ? 0 : parsed_value;
1328                         continue;
1329                 }
1330                 if (!strcmp(arg, "--strict-paths")) {
1331                         strict_paths = 1;
1332                         continue;
1333                 }
1334                 if (skip_prefix(arg, "--base-path=", &v)) {
1335                         base_path = v;
1336                         continue;
1337                 }
1338                 if (!strcmp(arg, "--base-path-relaxed")) {
1339                         base_path_relaxed = 1;
1340                         continue;
1341                 }
1342                 if (skip_prefix(arg, "--interpolated-path=", &v)) {
1343                         interpolated_path = v;
1344                         continue;
1345                 }
1346                 if (!strcmp(arg, "--reuseaddr")) {
1347                         reuseaddr = 1;
1348                         continue;
1349                 }
1350                 if (!strcmp(arg, "--user-path")) {
1351                         user_path = "";
1352                         continue;
1353                 }
1354                 if (skip_prefix(arg, "--user-path=", &v)) {
1355                         user_path = v;
1356                         continue;
1357                 }
1358                 if (skip_prefix(arg, "--pid-file=", &v)) {
1359                         pid_file = v;
1360                         continue;
1361                 }
1362                 if (!strcmp(arg, "--detach")) {
1363                         detach = 1;
1364                         continue;
1365                 }
1366                 if (skip_prefix(arg, "--user=", &v)) {
1367                         user_name = v;
1368                         continue;
1369                 }
1370                 if (skip_prefix(arg, "--group=", &v)) {
1371                         group_name = v;
1372                         continue;
1373                 }
1374                 if (skip_prefix(arg, "--enable=", &v)) {
1375                         enable_service(v, 1);
1376                         continue;
1377                 }
1378                 if (skip_prefix(arg, "--disable=", &v)) {
1379                         enable_service(v, 0);
1380                         continue;
1381                 }
1382                 if (skip_prefix(arg, "--allow-override=", &v)) {
1383                         make_service_overridable(v, 1);
1384                         continue;
1385                 }
1386                 if (skip_prefix(arg, "--forbid-override=", &v)) {
1387                         make_service_overridable(v, 0);
1388                         continue;
1389                 }
1390                 if (!strcmp(arg, "--informative-errors")) {
1391                         informative_errors = 1;
1392                         continue;
1393                 }
1394                 if (!strcmp(arg, "--no-informative-errors")) {
1395                         informative_errors = 0;
1396                         continue;
1397                 }
1398                 if (!strcmp(arg, "--")) {
1399                         ok_paths = &argv[i+1];
1400                         break;
1401                 } else if (arg[0] != '-') {
1402                         ok_paths = &argv[i];
1403                         break;
1404                 }
1405
1406                 usage(daemon_usage);
1407         }
1408
1409         if (log_destination == LOG_DESTINATION_UNSET) {
1410                 if (inetd_mode || detach)
1411                         log_destination = LOG_DESTINATION_SYSLOG;
1412                 else
1413                         log_destination = LOG_DESTINATION_STDERR;
1414         }
1415
1416         if (log_destination == LOG_DESTINATION_SYSLOG) {
1417                 openlog("git-daemon", LOG_PID, LOG_DAEMON);
1418                 set_die_routine(daemon_die);
1419         } else
1420                 /* avoid splitting a message in the middle */
1421                 setvbuf(stderr, NULL, _IOFBF, 4096);
1422
1423         if (inetd_mode && (detach || group_name || user_name))
1424                 die("--detach, --user and --group are incompatible with --inetd");
1425
1426         if (inetd_mode && (listen_port || (listen_addr.nr > 0)))
1427                 die("--listen= and --port= are incompatible with --inetd");
1428         else if (listen_port == 0)
1429                 listen_port = DEFAULT_GIT_PORT;
1430
1431         if (group_name && !user_name)
1432                 die("--group supplied without --user");
1433
1434         if (user_name)
1435                 cred = prepare_credentials(user_name, group_name);
1436
1437         if (strict_paths && (!ok_paths || !*ok_paths))
1438                 die("option --strict-paths requires '<directory>' arguments");
1439
1440         if (base_path && !is_directory(base_path))
1441                 die("base-path '%s' does not exist or is not a directory",
1442                     base_path);
1443
1444         if (log_destination != LOG_DESTINATION_STDERR) {
1445                 if (!freopen("/dev/null", "w", stderr))
1446                         die_errno("failed to redirect stderr to /dev/null");
1447         }
1448
1449         if (inetd_mode || serve_mode) {
1450                 ret = execute();
1451         } else {
1452                 if (detach) {
1453                         if (daemonize())
1454                                 die("--detach not supported on this platform");
1455                 }
1456
1457                 if (pid_file)
1458                         write_file(pid_file, "%"PRIuMAX, (uintmax_t) getpid());
1459
1460                 /* prepare argv for serving-processes */
1461                 strvec_push(&cld_argv, argv[0]); /* git-daemon */
1462                 strvec_push(&cld_argv, "--serve");
1463                 for (i = 1; i < argc; ++i)
1464                         strvec_push(&cld_argv, argv[i]);
1465
1466                 ret = serve(&listen_addr, listen_port, cred);
1467         }
1468
1469         string_list_clear(&listen_addr, 0);
1470         return ret;
1471 }