daemon.c

   1 #include "cache.h"
   2 #include "abspath.h"
   3 #include "alloc.h"
   4 #include "config.h"
   5 #include "pkt-line.h"
   6 #include "run-command.h"
   7 #include "strbuf.h"
   8 #include "string-list.h"
   9
  10 #ifdef NO_INITGROUPS
  11 #define initgroups(x, y) (0) /* nothing */
  12 #endif
  13
  14 static enum log_destination {
  15         LOG_DESTINATION_UNSET = -1,
  16         LOG_DESTINATION_NONE = 0,
  17         LOG_DESTINATION_STDERR = 1,
  18         LOG_DESTINATION_SYSLOG = 2,
  19 } log_destination = LOG_DESTINATION_UNSET;
  20 static int verbose;
  21 static int reuseaddr;
  22 static int informative_errors;
  23
  24 static const char daemon_usage[] =
  25 "git daemon [--verbose] [--syslog] [--export-all]\n"
  26 "           [--timeout=<n>] [--init-timeout=<n>] [--max-connections=<n>]\n"
  27 "           [--strict-paths] [--base-path=<path>] [--base-path-relaxed]\n"
  28 "           [--user-path | --user-path=<path>]\n"
  29 "           [--interpolated-path=<path>]\n"
  30 "           [--reuseaddr] [--pid-file=<file>]\n"
  31 "           [--(enable|disable|allow-override|forbid-override)=<service>]\n"
  32 "           [--access-hook=<path>]\n"
  33 "           [--inetd | [--listen=<host_or_ipaddr>] [--port=<n>]\n"
  34 "                      [--detach] [--user=<user> [--group=<group>]]\n"
  35 "           [--log-destination=(stderr|syslog|none)]\n"
  36 "           [<directory>...]";
  37
  38 /* List of acceptable pathname prefixes */
  39 static const char **ok_paths;
  40 static int strict_paths;
  41
  42 /* If this is set, git-daemon-export-ok is not required */
  43 static int export_all_trees;
  44
  45 /* Take all paths relative to this one if non-NULL */
  46 static const char *base_path;
  47 static const char *interpolated_path;
  48 static int base_path_relaxed;
  49
  50 /* If defined, ~user notation is allowed and the string is inserted
  51  * after ~user/.  E.g. a request to git://host/~alice/frotz would
  52  * go to /home/alice/pub_git/frotz with --user-path=pub_git.
  53  */
  54 static const char *user_path;
  55
  56 /* Timeout, and initial timeout */
  57 static unsigned int timeout;
  58 static unsigned int init_timeout;
  59
  60 struct hostinfo {
  61         struct strbuf hostname;
  62         struct strbuf canon_hostname;
  63         struct strbuf ip_address;
  64         struct strbuf tcp_port;
  65         unsigned int hostname_lookup_done:1;
  66         unsigned int saw_extended_args:1;
  67 };
  68 #define HOSTINFO_INIT { \
  69         .hostname = STRBUF_INIT, \
  70         .canon_hostname = STRBUF_INIT, \
  71         .ip_address = STRBUF_INIT, \
  72         .tcp_port = STRBUF_INIT, \
  73 }
  74
  75 static void lookup_hostname(struct hostinfo *hi);
  76
  77 static const char *get_canon_hostname(struct hostinfo *hi)
  78 {
  79         lookup_hostname(hi);
  80         return hi->canon_hostname.buf;
  81 }
  82
  83 static const char *get_ip_address(struct hostinfo *hi)
  84 {
  85         lookup_hostname(hi);
  86         return hi->ip_address.buf;
  87 }
  88
  89 static void logreport(int priority, const char *err, va_list params)
  90 {
  91         switch (log_destination) {
  92         case LOG_DESTINATION_SYSLOG: {
  93                 char buf[1024];
  94                 vsnprintf(buf, sizeof(buf), err, params);
  95                 syslog(priority, "%s", buf);
  96                 break;
  97         }
  98         case LOG_DESTINATION_STDERR:
  99                 /*
 100                  * Since stderr is set to buffered mode, the
 101                  * logging of different processes will not overlap
 102                  * unless they overflow the (rather big) buffers.
 103                  */
 104                 fprintf(stderr, "[%"PRIuMAX"] ", (uintmax_t)getpid());
 105                 vfprintf(stderr, err, params);
 106                 fputc('\n', stderr);
 107                 fflush(stderr);
 108                 break;
 109         case LOG_DESTINATION_NONE:
 110                 break;
 111         case LOG_DESTINATION_UNSET:
 112                 BUG("log destination not initialized correctly");
 113         }
 114 }
 115
 116 __attribute__((format (printf, 1, 2)))
 117 static void logerror(const char *err, ...)
 118 {
 119         va_list params;
 120         va_start(params, err);
 121         logreport(LOG_ERR, err, params);
 122         va_end(params);
 123 }
 124
 125 __attribute__((format (printf, 1, 2)))
 126 static void loginfo(const char *err, ...)
 127 {
 128         va_list params;
 129         if (!verbose)
 130                 return;
 131         va_start(params, err);
 132         logreport(LOG_INFO, err, params);
 133         va_end(params);
 134 }
 135
 136 static void NORETURN daemon_die(const char *err, va_list params)
 137 {
 138         logreport(LOG_ERR, err, params);
 139         exit(1);
 140 }
 141
 142 struct expand_path_context {
 143         const char *directory;
 144         struct hostinfo *hostinfo;
 145 };
 146
 147 static size_t expand_path(struct strbuf *sb, const char *placeholder, void *ctx)
 148 {
 149         struct expand_path_context *context = ctx;
 150         struct hostinfo *hi = context->hostinfo;
 151
 152         switch (placeholder[0]) {
 153         case 'H':
 154                 strbuf_addbuf(sb, &hi->hostname);
 155                 return 1;
 156         case 'C':
 157                 if (placeholder[1] == 'H') {
 158                         strbuf_addstr(sb, get_canon_hostname(hi));
 159                         return 2;
 160                 }
 161                 break;
 162         case 'I':
 163                 if (placeholder[1] == 'P') {
 164                         strbuf_addstr(sb, get_ip_address(hi));
 165                         return 2;
 166                 }
 167                 break;
 168         case 'P':
 169                 strbuf_addbuf(sb, &hi->tcp_port);
 170                 return 1;
 171         case 'D':
 172                 strbuf_addstr(sb, context->directory);
 173                 return 1;
 174         }
 175         return 0;
 176 }
 177
 178 static const char *path_ok(const char *directory, struct hostinfo *hi)
 179 {
 180         static char rpath[PATH_MAX];
 181         static char interp_path[PATH_MAX];
 182         size_t rlen;
 183         const char *path;
 184         const char *dir;
 185
 186         dir = directory;
 187
 188         if (daemon_avoid_alias(dir)) {
 189                 logerror("'%s': aliased", dir);
 190                 return NULL;
 191         }
 192
 193         if (*dir == '~') {
 194                 if (!user_path) {
 195                         logerror("'%s': User-path not allowed", dir);
 196                         return NULL;
 197                 }
 198                 if (*user_path) {
 199                         /* Got either "~alice" or "~alice/foo";
 200                          * rewrite them to "~alice/%s" or
 201                          * "~alice/%s/foo".
 202                          */
 203                         int namlen, restlen = strlen(dir);
 204                         const char *slash = strchr(dir, '/');
 205                         if (!slash)
 206                                 slash = dir + restlen;
 207                         namlen = slash - dir;
 208                         restlen -= namlen;
 209                         loginfo("userpath <%s>, request <%s>, namlen %d, restlen %d, slash <%s>", user_path, dir, namlen, restlen, slash);
 210                         rlen = snprintf(rpath, sizeof(rpath), "%.*s/%s%.*s",
 211                                         namlen, dir, user_path, restlen, slash);
 212                         if (rlen >= sizeof(rpath)) {
 213                                 logerror("user-path too large: %s", rpath);
 214                                 return NULL;
 215                         }
 216                         dir = rpath;
 217                 }
 218         }
 219         else if (interpolated_path && hi->saw_extended_args) {
 220                 struct strbuf expanded_path = STRBUF_INIT;
 221                 struct expand_path_context context;
 222
 223                 context.directory = directory;
 224                 context.hostinfo = hi;
 225
 226                 if (*dir != '/') {
 227                         /* Allow only absolute */
 228                         logerror("'%s': Non-absolute path denied (interpolated-path active)", dir);
 229                         return NULL;
 230                 }
 231
 232                 strbuf_expand(&expanded_path, interpolated_path,
 233                               expand_path, &context);
 234
 235                 rlen = strlcpy(interp_path, expanded_path.buf,
 236                                sizeof(interp_path));
 237                 strbuf_release(&expanded_path);
 238                 if (rlen >= sizeof(interp_path)) {
 239                         logerror("interpolated path too large: %s",
 240                                  interp_path);
 241                         return NULL;
 242                 }
 243
 244                 loginfo("Interpolated dir '%s'", interp_path);
 245
 246                 dir = interp_path;
 247         }
 248         else if (base_path) {
 249                 if (*dir != '/') {
 250                         /* Allow only absolute */
 251                         logerror("'%s': Non-absolute path denied (base-path active)", dir);
 252                         return NULL;
 253                 }
 254                 rlen = snprintf(rpath, sizeof(rpath), "%s%s", base_path, dir);
 255                 if (rlen >= sizeof(rpath)) {
 256                         logerror("base-path too large: %s", rpath);
 257                         return NULL;
 258                 }
 259                 dir = rpath;
 260         }
 261
 262         path = enter_repo(dir, strict_paths);
 263         if (!path && base_path && base_path_relaxed) {
 264                 /*
 265                  * if we fail and base_path_relaxed is enabled, try without
 266                  * prefixing the base path
 267                  */
 268                 dir = directory;
 269                 path = enter_repo(dir, strict_paths);
 270         }
 271
 272         if (!path) {
 273                 logerror("'%s' does not appear to be a git repository", dir);
 274                 return NULL;
 275         }
 276
 277         if ( ok_paths && *ok_paths ) {
 278                 const char **pp;
 279                 int pathlen = strlen(path);
 280
 281                 /* The validation is done on the paths after enter_repo
 282                  * appends optional {.git,.git/.git} and friends, but
 283                  * it does not use getcwd().  So if your /pub is
 284                  * a symlink to /mnt/pub, you can include /pub and
 285                  * do not have to say /mnt/pub.
 286                  * Do not say /pub/.
 287                  */
 288                 for ( pp = ok_paths ; *pp ; pp++ ) {
 289                         int len = strlen(*pp);
 290                         if (len <= pathlen &&
 291                             !memcmp(*pp, path, len) &&
 292                             (path[len] == '\0' ||
 293                              (!strict_paths && path[len] == '/')))
 294                                 return path;
 295                 }
 296         }
 297         else {
 298                 /* be backwards compatible */
 299                 if (!strict_paths)
 300                         return path;
 301         }
 302
 303         logerror("'%s': not in directory list", path);
 304         return NULL;            /* Fallthrough. Deny by default */
 305 }
 306
 307 typedef int (*daemon_service_fn)(const struct strvec *env);
 308 struct daemon_service {
 309         const char *name;
 310         const char *config_name;
 311         daemon_service_fn fn;
 312         int enabled;
 313         int overridable;
 314 };
 315
 316 static int daemon_error(const char *dir, const char *msg)
 317 {
 318         if (!informative_errors)
 319                 msg = "access denied or repository not exported";
 320         packet_write_fmt(1, "ERR %s: %s", msg, dir);
 321         return -1;
 322 }
 323
 324 static const char *access_hook;
 325
 326 static int run_access_hook(struct daemon_service *service, const char *dir,
 327                            const char *path, struct hostinfo *hi)
 328 {
 329         struct child_process child = CHILD_PROCESS_INIT;
 330         struct strbuf buf = STRBUF_INIT;
 331         char *eol;
 332         int seen_errors = 0;
 333
 334         strvec_push(&child.args, access_hook);
 335         strvec_push(&child.args, service->name);
 336         strvec_push(&child.args, path);
 337         strvec_push(&child.args, hi->hostname.buf);
 338         strvec_push(&child.args, get_canon_hostname(hi));
 339         strvec_push(&child.args, get_ip_address(hi));
 340         strvec_push(&child.args, hi->tcp_port.buf);
 341
 342         child.use_shell = 1;
 343         child.no_stdin = 1;
 344         child.no_stderr = 1;
 345         child.out = -1;
 346         if (start_command(&child)) {
 347                 logerror("daemon access hook '%s' failed to start",
 348                          access_hook);
 349                 goto error_return;
 350         }
 351         if (strbuf_read(&buf, child.out, 0) < 0) {
 352                 logerror("failed to read from pipe to daemon access hook '%s'",
 353                          access_hook);
 354                 strbuf_reset(&buf);
 355                 seen_errors = 1;
 356         }
 357         if (close(child.out) < 0) {
 358                 logerror("failed to close pipe to daemon access hook '%s'",
 359                          access_hook);
 360                 seen_errors = 1;
 361         }
 362         if (finish_command(&child))
 363                 seen_errors = 1;
 364
 365         if (!seen_errors) {
 366                 strbuf_release(&buf);
 367                 return 0;
 368         }
 369
 370 error_return:
 371         strbuf_ltrim(&buf);
 372         if (!buf.len)
 373                 strbuf_addstr(&buf, "service rejected");
 374         eol = strchr(buf.buf, '\n');
 375         if (eol)
 376                 *eol = '\0';
 377         errno = EACCES;
 378         daemon_error(dir, buf.buf);
 379         strbuf_release(&buf);
 380         return -1;
 381 }
 382
 383 static int run_service(const char *dir, struct daemon_service *service,
 384                        struct hostinfo *hi, const struct strvec *env)
 385 {
 386         const char *path;
 387         int enabled = service->enabled;
 388         struct strbuf var = STRBUF_INIT;
 389
 390         loginfo("Request %s for '%s'", service->name, dir);
 391
 392         if (!enabled && !service->overridable) {
 393                 logerror("'%s': service not enabled.", service->name);
 394                 errno = EACCES;
 395                 return daemon_error(dir, "service not enabled");
 396         }
 397
 398         if (!(path = path_ok(dir, hi)))
 399                 return daemon_error(dir, "no such repository");
 400
 401         /*
 402          * Security on the cheap.
 403          *
 404          * We want a readable HEAD, usable "objects" directory, and
 405          * a "git-daemon-export-ok" flag that says that the other side
 406          * is ok with us doing this.
 407          *
 408          * path_ok() uses enter_repo() and checks for included directories.
 409          * We only need to make sure the repository is exported.
 410          */
 411
 412         if (!export_all_trees && access("git-daemon-export-ok", F_OK)) {
 413                 logerror("'%s': repository not exported.", path);
 414                 errno = EACCES;
 415                 return daemon_error(dir, "repository not exported");
 416         }
 417
 418         if (service->overridable) {
 419                 strbuf_addf(&var, "daemon.%s", service->config_name);
 420                 git_config_get_bool(var.buf, &enabled);
 421                 strbuf_release(&var);
 422         }
 423         if (!enabled) {
 424                 logerror("'%s': service not enabled for '%s'",
 425                          service->name, path);
 426                 errno = EACCES;
 427                 return daemon_error(dir, "service not enabled");
 428         }
 429
 430         /*
 431          * Optionally, a hook can choose to deny access to the
 432          * repository depending on the phase of the moon.
 433          */
 434         if (access_hook && run_access_hook(service, dir, path, hi))
 435                 return -1;
 436
 437         /*
 438          * We'll ignore SIGTERM from now on, we have a
 439          * good client.
 440          */
 441         signal(SIGTERM, SIG_IGN);
 442
 443         return service->fn(env);
 444 }
 445
 446 static void copy_to_log(int fd)
 447 {
 448         struct strbuf line = STRBUF_INIT;
 449         FILE *fp;
 450
 451         fp = fdopen(fd, "r");
 452         if (!fp) {
 453                 logerror("fdopen of error channel failed");
 454                 close(fd);
 455                 return;
 456         }
 457
 458         while (strbuf_getline_lf(&line, fp) != EOF) {
 459                 logerror("%s", line.buf);
 460                 strbuf_setlen(&line, 0);
 461         }
 462
 463         strbuf_release(&line);
 464         fclose(fp);
 465 }
 466
 467 static int run_service_command(struct child_process *cld)
 468 {
 469         strvec_push(&cld->args, ".");
 470         cld->git_cmd = 1;
 471         cld->err = -1;
 472         if (start_command(cld))
 473                 return -1;
 474
 475         close(0);
 476         close(1);
 477
 478         copy_to_log(cld->err);
 479
 480         return finish_command(cld);
 481 }
 482
 483 static int upload_pack(const struct strvec *env)
 484 {
 485         struct child_process cld = CHILD_PROCESS_INIT;
 486         strvec_pushl(&cld.args, "upload-pack", "--strict", NULL);
 487         strvec_pushf(&cld.args, "--timeout=%u", timeout);
 488
 489         strvec_pushv(&cld.env, env->v);
 490
 491         return run_service_command(&cld);
 492 }
 493
 494 static int upload_archive(const struct strvec *env)
 495 {
 496         struct child_process cld = CHILD_PROCESS_INIT;
 497         strvec_push(&cld.args, "upload-archive");
 498
 499         strvec_pushv(&cld.env, env->v);
 500
 501         return run_service_command(&cld);
 502 }
 503
 504 static int receive_pack(const struct strvec *env)
 505 {
 506         struct child_process cld = CHILD_PROCESS_INIT;
 507         strvec_push(&cld.args, "receive-pack");
 508
 509         strvec_pushv(&cld.env, env->v);
 510
 511         return run_service_command(&cld);
 512 }
 513
 514 static struct daemon_service daemon_service[] = {
 515         { "upload-archive", "uploadarch", upload_archive, 0, 1 },
 516         { "upload-pack", "uploadpack", upload_pack, 1, 1 },
 517         { "receive-pack", "receivepack", receive_pack, 0, 1 },
 518 };
 519
 520 static void enable_service(const char *name, int ena)
 521 {
 522         int i;
 523         for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
 524                 if (!strcmp(daemon_service[i].name, name)) {
 525                         daemon_service[i].enabled = ena;
 526                         return;
 527                 }
 528         }
 529         die("No such service %s", name);
 530 }
 531
 532 static void make_service_overridable(const char *name, int ena)
 533 {
 534         int i;
 535         for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
 536                 if (!strcmp(daemon_service[i].name, name)) {
 537                         daemon_service[i].overridable = ena;
 538                         return;
 539                 }
 540         }
 541         die("No such service %s", name);
 542 }
 543
 544 static void parse_host_and_port(char *hostport, char **host,
 545         char **port)
 546 {
 547         if (*hostport == '[') {
 548                 char *end;
 549
 550                 end = strchr(hostport, ']');
 551                 if (!end)
 552                         die("Invalid request ('[' without ']')");
 553                 *end = '\0';
 554                 *host = hostport + 1;
 555                 if (!end[1])
 556                         *port = NULL;
 557                 else if (end[1] == ':')
 558                         *port = end + 2;
 559                 else
 560                         die("Garbage after end of host part");
 561         } else {
 562                 *host = hostport;
 563                 *port = strrchr(hostport, ':');
 564                 if (*port) {
 565                         **port = '\0';
 566                         ++*port;
 567                 }
 568         }
 569 }
 570
 571 /*
 572  * Sanitize a string from the client so that it's OK to be inserted into a
 573  * filesystem path. Specifically, we disallow directory separators, runs
 574  * of "..", and trailing and leading dots, which means that the client
 575  * cannot escape our base path via ".." traversal.
 576  */
 577 static void sanitize_client(struct strbuf *out, const char *in)
 578 {
 579         for (; *in; in++) {
 580                 if (is_dir_sep(*in))
 581                         continue;
 582                 if (*in == '.' && (!out->len || out->buf[out->len - 1] == '.'))
 583                         continue;
 584                 strbuf_addch(out, *in);
 585         }
 586
 587         while (out->len && out->buf[out->len - 1] == '.')
 588                 strbuf_setlen(out, out->len - 1);
 589 }
 590
 591 /*
 592  * Like sanitize_client, but we also perform any canonicalization
 593  * to make life easier on the admin.
 594  */
 595 static void canonicalize_client(struct strbuf *out, const char *in)
 596 {
 597         sanitize_client(out, in);
 598         strbuf_tolower(out);
 599 }
 600
 601 /*
 602  * Read the host as supplied by the client connection.
 603  *
 604  * Returns a pointer to the character after the NUL byte terminating the host
 605  * argument, or 'extra_args' if there is no host argument.
 606  */
 607 static char *parse_host_arg(struct hostinfo *hi, char *extra_args, int buflen)
 608 {
 609         char *val;
 610         int vallen;
 611         char *end = extra_args + buflen;
 612
 613         if (extra_args < end && *extra_args) {
 614                 hi->saw_extended_args = 1;
 615                 if (strncasecmp("host=", extra_args, 5) == 0) {
 616                         val = extra_args + 5;
 617                         vallen = strlen(val) + 1;
 618                         loginfo("Extended attribute \"host\": %s", val);
 619                         if (*val) {
 620                                 /* Split <host>:<port> at colon. */
 621                                 char *host;
 622                                 char *port;
 623                                 parse_host_and_port(val, &host, &port);
 624                                 if (port)
 625                                         sanitize_client(&hi->tcp_port, port);
 626                                 canonicalize_client(&hi->hostname, host);
 627                                 hi->hostname_lookup_done = 0;
 628                         }
 629
 630                         /* On to the next one */
 631                         extra_args = val + vallen;
 632                 }
 633                 if (extra_args < end && *extra_args)
 634                         die("Invalid request");
 635         }
 636
 637         return extra_args;
 638 }
 639
 640 static void parse_extra_args(struct hostinfo *hi, struct strvec *env,
 641                              char *extra_args, int buflen)
 642 {
 643         const char *end = extra_args + buflen;
 644         struct strbuf git_protocol = STRBUF_INIT;
 645
 646         /* First look for the host argument */
 647         extra_args = parse_host_arg(hi, extra_args, buflen);
 648
 649         /* Look for additional arguments places after a second NUL byte */
 650         for (; extra_args < end; extra_args += strlen(extra_args) + 1) {
 651                 const char *arg = extra_args;
 652
 653                 /*
 654                  * Parse the extra arguments, adding most to 'git_protocol'
 655                  * which will be used to set the 'GIT_PROTOCOL' envvar in the
 656                  * service that will be run.
 657                  *
 658                  * If there ends up being a particular arg in the future that
 659                  * git-daemon needs to parse specifically (like the 'host' arg)
 660                  * then it can be parsed here and not added to 'git_protocol'.
 661                  */
 662                 if (*arg) {
 663                         if (git_protocol.len > 0)
 664                                 strbuf_addch(&git_protocol, ':');
 665                         strbuf_addstr(&git_protocol, arg);
 666                 }
 667         }
 668
 669         if (git_protocol.len > 0) {
 670                 loginfo("Extended attribute \"protocol\": %s", git_protocol.buf);
 671                 strvec_pushf(env, GIT_PROTOCOL_ENVIRONMENT "=%s",
 672                              git_protocol.buf);
 673         }
 674         strbuf_release(&git_protocol);
 675 }
 676
 677 /*
 678  * Locate canonical hostname and its IP address.
 679  */
 680 static void lookup_hostname(struct hostinfo *hi)
 681 {
 682         if (!hi->hostname_lookup_done && hi->hostname.len) {
 683 #ifndef NO_IPV6
 684                 struct addrinfo hints;
 685                 struct addrinfo *ai;
 686                 int gai;
 687                 static char addrbuf[HOST_NAME_MAX + 1];
 688
 689                 memset(&hints, 0, sizeof(hints));
 690                 hints.ai_flags = AI_CANONNAME;
 691
 692                 gai = getaddrinfo(hi->hostname.buf, NULL, &hints, &ai);
 693                 if (!gai) {
 694                         struct sockaddr_in *sin_addr = (void *)ai->ai_addr;
 695
 696                         inet_ntop(AF_INET, &sin_addr->sin_addr,
 697                                   addrbuf, sizeof(addrbuf));
 698                         strbuf_addstr(&hi->ip_address, addrbuf);
 699
 700                         if (ai->ai_canonname)
 701                                 sanitize_client(&hi->canon_hostname,
 702                                                 ai->ai_canonname);
 703                         else
 704                                 strbuf_addbuf(&hi->canon_hostname,
 705                                               &hi->ip_address);
 706
 707                         freeaddrinfo(ai);
 708                 }
 709 #else
 710                 struct hostent *hent;
 711                 struct sockaddr_in sa;
 712                 char **ap;
 713                 static char addrbuf[HOST_NAME_MAX + 1];
 714
 715                 hent = gethostbyname(hi->hostname.buf);
 716                 if (hent) {
 717                         ap = hent->h_addr_list;
 718                         memset(&sa, 0, sizeof sa);
 719                         sa.sin_family = hent->h_addrtype;
 720                         sa.sin_port = htons(0);
 721                         memcpy(&sa.sin_addr, *ap, hent->h_length);
 722
 723                         inet_ntop(hent->h_addrtype, &sa.sin_addr,
 724                                   addrbuf, sizeof(addrbuf));
 725
 726                         sanitize_client(&hi->canon_hostname, hent->h_name);
 727                         strbuf_addstr(&hi->ip_address, addrbuf);
 728                 }
 729 #endif
 730                 hi->hostname_lookup_done = 1;
 731         }
 732 }
 733
 734 static void hostinfo_clear(struct hostinfo *hi)
 735 {
 736         strbuf_release(&hi->hostname);
 737         strbuf_release(&hi->canon_hostname);
 738         strbuf_release(&hi->ip_address);
 739         strbuf_release(&hi->tcp_port);
 740 }
 741
 742 static void set_keep_alive(int sockfd)
 743 {
 744         int ka = 1;
 745
 746         if (setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, &ka, sizeof(ka)) < 0) {
 747                 if (errno != ENOTSOCK)
 748                         logerror("unable to set SO_KEEPALIVE on socket: %s",
 749                                 strerror(errno));
 750         }
 751 }
 752
 753 static int execute(void)
 754 {
 755         char *line = packet_buffer;
 756         int pktlen, len, i;
 757         char *addr = getenv("REMOTE_ADDR"), *port = getenv("REMOTE_PORT");
 758         struct hostinfo hi = HOSTINFO_INIT;
 759         struct strvec env = STRVEC_INIT;
 760
 761         if (addr)
 762                 loginfo("Connection from %s:%s", addr, port);
 763
 764         set_keep_alive(0);
 765         alarm(init_timeout ? init_timeout : timeout);
 766         pktlen = packet_read(0, packet_buffer, sizeof(packet_buffer), 0);
 767         alarm(0);
 768
 769         len = strlen(line);
 770         if (len && line[len-1] == '\n')
 771                 line[len-1] = 0;
 772
 773         /* parse additional args hidden behind a NUL byte */
 774         if (len != pktlen)
 775                 parse_extra_args(&hi, &env, line + len + 1, pktlen - len - 1);
 776
 777         for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
 778                 struct daemon_service *s = &(daemon_service[i]);
 779                 const char *arg;
 780
 781                 if (skip_prefix(line, "git-", &arg) &&
 782                     skip_prefix(arg, s->name, &arg) &&
 783                     *arg++ == ' ') {
 784                         /*
 785                          * Note: The directory here is probably context sensitive,
 786                          * and might depend on the actual service being performed.
 787                          */
 788                         int rc = run_service(arg, s, &hi, &env);
 789                         hostinfo_clear(&hi);
 790                         strvec_clear(&env);
 791                         return rc;
 792                 }
 793         }
 794
 795         hostinfo_clear(&hi);
 796         strvec_clear(&env);
 797         logerror("Protocol error: '%s'", line);
 798         return -1;
 799 }
 800
 801 static int addrcmp(const struct sockaddr_storage *s1,
 802     const struct sockaddr_storage *s2)
 803 {
 804         const struct sockaddr *sa1 = (const struct sockaddr*) s1;
 805         const struct sockaddr *sa2 = (const struct sockaddr*) s2;
 806
 807         if (sa1->sa_family != sa2->sa_family)
 808                 return sa1->sa_family - sa2->sa_family;
 809         if (sa1->sa_family == AF_INET)
 810                 return memcmp(&((struct sockaddr_in *)s1)->sin_addr,
 811                     &((struct sockaddr_in *)s2)->sin_addr,
 812                     sizeof(struct in_addr));
 813 #ifndef NO_IPV6
 814         if (sa1->sa_family == AF_INET6)
 815                 return memcmp(&((struct sockaddr_in6 *)s1)->sin6_addr,
 816                     &((struct sockaddr_in6 *)s2)->sin6_addr,
 817                     sizeof(struct in6_addr));
 818 #endif
 819         return 0;
 820 }
 821
 822 static int max_connections = 32;
 823
 824 static unsigned int live_children;
 825
 826 static struct child {
 827         struct child *next;
 828         struct child_process cld;
 829         struct sockaddr_storage address;
 830 } *firstborn;
 831
 832 static void add_child(struct child_process *cld, struct sockaddr *addr, socklen_t addrlen)
 833 {
 834         struct child *newborn, **cradle;
 835
 836         CALLOC_ARRAY(newborn, 1);
 837         live_children++;
 838         memcpy(&newborn->cld, cld, sizeof(*cld));
 839         memcpy(&newborn->address, addr, addrlen);
 840         for (cradle = &firstborn; *cradle; cradle = &(*cradle)->next)
 841                 if (!addrcmp(&(*cradle)->address, &newborn->address))
 842                         break;
 843         newborn->next = *cradle;
 844         *cradle = newborn;
 845 }
 846
 847 /*
 848  * This gets called if the number of connections grows
 849  * past "max_connections".
 850  *
 851  * We kill the newest connection from a duplicate IP.
 852  */
 853 static void kill_some_child(void)
 854 {
 855         const struct child *blanket, *next;
 856
 857         if (!(blanket = firstborn))
 858                 return;
 859
 860         for (; (next = blanket->next); blanket = next)
 861                 if (!addrcmp(&blanket->address, &next->address)) {
 862                         kill(blanket->cld.pid, SIGTERM);
 863                         break;
 864                 }
 865 }
 866
 867 static void check_dead_children(void)
 868 {
 869         int status;
 870         pid_t pid;
 871
 872         struct child **cradle, *blanket;
 873         for (cradle = &firstborn; (blanket = *cradle);)
 874                 if ((pid = waitpid(blanket->cld.pid, &status, WNOHANG)) > 1) {
 875                         const char *dead = "";
 876                         if (status)
 877                                 dead = " (with error)";
 878                         loginfo("[%"PRIuMAX"] Disconnected%s", (uintmax_t)pid, dead);
 879
 880                         /* remove the child */
 881                         *cradle = blanket->next;
 882                         live_children--;
 883                         child_process_clear(&blanket->cld);
 884                         free(blanket);
 885                 } else
 886                         cradle = &blanket->next;
 887 }
 888
 889 static struct strvec cld_argv = STRVEC_INIT;
 890 static void handle(int incoming, struct sockaddr *addr, socklen_t addrlen)
 891 {
 892         struct child_process cld = CHILD_PROCESS_INIT;
 893
 894         if (max_connections && live_children >= max_connections) {
 895                 kill_some_child();
 896                 sleep(1);  /* give it some time to die */
 897                 check_dead_children();
 898                 if (live_children >= max_connections) {
 899                         close(incoming);
 900                         logerror("Too many children, dropping connection");
 901                         return;
 902                 }
 903         }
 904
 905         if (addr->sa_family == AF_INET) {
 906                 char buf[128] = "";
 907                 struct sockaddr_in *sin_addr = (void *) addr;
 908                 inet_ntop(addr->sa_family, &sin_addr->sin_addr, buf, sizeof(buf));
 909                 strvec_pushf(&cld.env, "REMOTE_ADDR=%s", buf);
 910                 strvec_pushf(&cld.env, "REMOTE_PORT=%d",
 911                              ntohs(sin_addr->sin_port));
 912 #ifndef NO_IPV6
 913         } else if (addr->sa_family == AF_INET6) {
 914                 char buf[128] = "";
 915                 struct sockaddr_in6 *sin6_addr = (void *) addr;
 916                 inet_ntop(AF_INET6, &sin6_addr->sin6_addr, buf, sizeof(buf));
 917                 strvec_pushf(&cld.env, "REMOTE_ADDR=[%s]", buf);
 918                 strvec_pushf(&cld.env, "REMOTE_PORT=%d",
 919                              ntohs(sin6_addr->sin6_port));
 920 #endif
 921         }
 922
 923         strvec_pushv(&cld.args, cld_argv.v);
 924         cld.in = incoming;
 925         cld.out = dup(incoming);
 926
 927         if (start_command(&cld))
 928                 logerror("unable to fork");
 929         else
 930                 add_child(&cld, addr, addrlen);
 931 }
 932
 933 static void child_handler(int signo UNUSED)
 934 {
 935         /*
 936          * Otherwise empty handler because systemcalls will get interrupted
 937          * upon signal receipt
 938          * SysV needs the handler to be rearmed
 939          */
 940         signal(SIGCHLD, child_handler);
 941 }
 942
 943 static int set_reuse_addr(int sockfd)
 944 {
 945         int on = 1;
 946
 947         if (!reuseaddr)
 948                 return 0;
 949         return setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR,
 950                           &on, sizeof(on));
 951 }
 952
 953 struct socketlist {
 954         int *list;
 955         size_t nr;
 956         size_t alloc;
 957 };
 958
 959 static const char *ip2str(int family, struct sockaddr *sin, socklen_t len)
 960 {
 961 #ifdef NO_IPV6
 962         static char ip[INET_ADDRSTRLEN];
 963 #else
 964         static char ip[INET6_ADDRSTRLEN];
 965 #endif
 966
 967         switch (family) {
 968 #ifndef NO_IPV6
 969         case AF_INET6:
 970                 inet_ntop(family, &((struct sockaddr_in6*)sin)->sin6_addr, ip, len);
 971                 break;
 972 #endif
 973         case AF_INET:
 974                 inet_ntop(family, &((struct sockaddr_in*)sin)->sin_addr, ip, len);
 975                 break;
 976         default:
 977                 xsnprintf(ip, sizeof(ip), "<unknown>");
 978         }
 979         return ip;
 980 }
 981
 982 #ifndef NO_IPV6
 983
 984 static int setup_named_sock(char *listen_addr, int listen_port, struct socketlist *socklist)
 985 {
 986         int socknum = 0;
 987         char pbuf[NI_MAXSERV];
 988         struct addrinfo hints, *ai0, *ai;
 989         int gai;
 990         long flags;
 991
 992         xsnprintf(pbuf, sizeof(pbuf), "%d", listen_port);
 993         memset(&hints, 0, sizeof(hints));
 994         hints.ai_family = AF_UNSPEC;
 995         hints.ai_socktype = SOCK_STREAM;
 996         hints.ai_protocol = IPPROTO_TCP;
 997         hints.ai_flags = AI_PASSIVE;
 998
 999         gai = getaddrinfo(listen_addr, pbuf, &hints, &ai0);
1000         if (gai) {
1001                 logerror("getaddrinfo() for %s failed: %s", listen_addr, gai_strerror(gai));
1002                 return 0;
1003         }
1004
1005         for (ai = ai0; ai; ai = ai->ai_next) {
1006                 int sockfd;
1007
1008                 sockfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1009                 if (sockfd < 0)
1010                         continue;
1011                 if (sockfd >= FD_SETSIZE) {
1012                         logerror("Socket descriptor too large");
1013                         close(sockfd);
1014                         continue;
1015                 }
1016
1017 #ifdef IPV6_V6ONLY
1018                 if (ai->ai_family == AF_INET6) {
1019                         int on = 1;
1020                         setsockopt(sockfd, IPPROTO_IPV6, IPV6_V6ONLY,
1021                                    &on, sizeof(on));
1022                         /* Note: error is not fatal */
1023                 }
1024 #endif
1025
1026                 if (set_reuse_addr(sockfd)) {
1027                         logerror("Could not set SO_REUSEADDR: %s", strerror(errno));
1028                         close(sockfd);
1029                         continue;
1030                 }
1031
1032                 set_keep_alive(sockfd);
1033
1034                 if (bind(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
1035                         logerror("Could not bind to %s: %s",
1036                                  ip2str(ai->ai_family, ai->ai_addr, ai->ai_addrlen),
1037                                  strerror(errno));
1038                         close(sockfd);
1039                         continue;       /* not fatal */
1040                 }
1041                 if (listen(sockfd, 5) < 0) {
1042                         logerror("Could not listen to %s: %s",
1043                                  ip2str(ai->ai_family, ai->ai_addr, ai->ai_addrlen),
1044                                  strerror(errno));
1045                         close(sockfd);
1046                         continue;       /* not fatal */
1047                 }
1048
1049                 flags = fcntl(sockfd, F_GETFD, 0);
1050                 if (flags >= 0)
1051                         fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
1052
1053                 ALLOC_GROW(socklist->list, socklist->nr + 1, socklist->alloc);
1054                 socklist->list[socklist->nr++] = sockfd;
1055                 socknum++;
1056         }
1057
1058         freeaddrinfo(ai0);
1059
1060         return socknum;
1061 }
1062
1063 #else /* NO_IPV6 */
1064
1065 static int setup_named_sock(char *listen_addr, int listen_port, struct socketlist *socklist)
1066 {
1067         struct sockaddr_in sin;
1068         int sockfd;
1069         long flags;
1070
1071         memset(&sin, 0, sizeof sin);
1072         sin.sin_family = AF_INET;
1073         sin.sin_port = htons(listen_port);
1074
1075         if (listen_addr) {
1076                 /* Well, host better be an IP address here. */
1077                 if (inet_pton(AF_INET, listen_addr, &sin.sin_addr.s_addr) <= 0)
1078                         return 0;
1079         } else {
1080                 sin.sin_addr.s_addr = htonl(INADDR_ANY);
1081         }
1082
1083         sockfd = socket(AF_INET, SOCK_STREAM, 0);
1084         if (sockfd < 0)
1085                 return 0;
1086
1087         if (set_reuse_addr(sockfd)) {
1088                 logerror("Could not set SO_REUSEADDR: %s", strerror(errno));
1089                 close(sockfd);
1090                 return 0;
1091         }
1092
1093         set_keep_alive(sockfd);
1094
1095         if ( bind(sockfd, (struct sockaddr *)&sin, sizeof sin) < 0 ) {
1096                 logerror("Could not bind to %s: %s",
1097                          ip2str(AF_INET, (struct sockaddr *)&sin, sizeof(sin)),
1098                          strerror(errno));
1099                 close(sockfd);
1100                 return 0;
1101         }
1102
1103         if (listen(sockfd, 5) < 0) {
1104                 logerror("Could not listen to %s: %s",
1105                          ip2str(AF_INET, (struct sockaddr *)&sin, sizeof(sin)),
1106                          strerror(errno));
1107                 close(sockfd);
1108                 return 0;
1109         }
1110
1111         flags = fcntl(sockfd, F_GETFD, 0);
1112         if (flags >= 0)
1113                 fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
1114
1115         ALLOC_GROW(socklist->list, socklist->nr + 1, socklist->alloc);
1116         socklist->list[socklist->nr++] = sockfd;
1117         return 1;
1118 }
1119
1120 #endif
1121
1122 static void socksetup(struct string_list *listen_addr, int listen_port, struct socketlist *socklist)
1123 {
1124         if (!listen_addr->nr)
1125                 setup_named_sock(NULL, listen_port, socklist);
1126         else {
1127                 int i, socknum;
1128                 for (i = 0; i < listen_addr->nr; i++) {
1129                         socknum = setup_named_sock(listen_addr->items[i].string,
1130                                                    listen_port, socklist);
1131
1132                         if (socknum == 0)
1133                                 logerror("unable to allocate any listen sockets for host %s on port %u",
1134                                          listen_addr->items[i].string, listen_port);
1135                 }
1136         }
1137 }
1138
1139 static int service_loop(struct socketlist *socklist)
1140 {
1141         struct pollfd *pfd;
1142         int i;
1143
1144         CALLOC_ARRAY(pfd, socklist->nr);
1145
1146         for (i = 0; i < socklist->nr; i++) {
1147                 pfd[i].fd = socklist->list[i];
1148                 pfd[i].events = POLLIN;
1149         }
1150
1151         signal(SIGCHLD, child_handler);
1152
1153         for (;;) {
1154                 int i;
1155
1156                 check_dead_children();
1157
1158                 if (poll(pfd, socklist->nr, -1) < 0) {
1159                         if (errno != EINTR) {
1160                                 logerror("Poll failed, resuming: %s",
1161                                       strerror(errno));
1162                                 sleep(1);
1163                         }
1164                         continue;
1165                 }
1166
1167                 for (i = 0; i < socklist->nr; i++) {
1168                         if (pfd[i].revents & POLLIN) {
1169                                 union {
1170                                         struct sockaddr sa;
1171                                         struct sockaddr_in sai;
1172 #ifndef NO_IPV6
1173                                         struct sockaddr_in6 sai6;
1174 #endif
1175                                 } ss;
1176                                 socklen_t sslen = sizeof(ss);
1177                                 int incoming = accept(pfd[i].fd, &ss.sa, &sslen);
1178                                 if (incoming < 0) {
1179                                         switch (errno) {
1180                                         case EAGAIN:
1181                                         case EINTR:
1182                                         case ECONNABORTED:
1183                                                 continue;
1184                                         default:
1185                                                 die_errno("accept returned");
1186                                         }
1187                                 }
1188                                 handle(incoming, &ss.sa, sslen);
1189                         }
1190                 }
1191         }
1192 }
1193
1194 #ifdef NO_POSIX_GOODIES
1195
1196 struct credentials;
1197
1198 static void drop_privileges(struct credentials *cred)
1199 {
1200         /* nothing */
1201 }
1202
1203 static struct credentials *prepare_credentials(const char *user_name,
1204     const char *group_name)
1205 {
1206         die("--user not supported on this platform");
1207 }
1208
1209 #else
1210
1211 struct credentials {
1212         struct passwd *pass;
1213         gid_t gid;
1214 };
1215
1216 static void drop_privileges(struct credentials *cred)
1217 {
1218         if (cred && (initgroups(cred->pass->pw_name, cred->gid) ||
1219             setgid (cred->gid) || setuid(cred->pass->pw_uid)))
1220                 die("cannot drop privileges");
1221 }
1222
1223 static struct credentials *prepare_credentials(const char *user_name,
1224     const char *group_name)
1225 {
1226         static struct credentials c;
1227
1228         c.pass = getpwnam(user_name);
1229         if (!c.pass)
1230                 die("user not found - %s", user_name);
1231
1232         if (!group_name)
1233                 c.gid = c.pass->pw_gid;
1234         else {
1235                 struct group *group = getgrnam(group_name);
1236                 if (!group)
1237                         die("group not found - %s", group_name);
1238
1239                 c.gid = group->gr_gid;
1240         }
1241
1242         return &c;
1243 }
1244 #endif
1245
1246 static int serve(struct string_list *listen_addr, int listen_port,
1247     struct credentials *cred)
1248 {
1249         struct socketlist socklist = { NULL, 0, 0 };
1250
1251         socksetup(listen_addr, listen_port, &socklist);
1252         if (socklist.nr == 0)
1253                 die("unable to allocate any listen sockets on port %u",
1254                     listen_port);
1255
1256         drop_privileges(cred);
1257
1258         loginfo("Ready to rumble");
1259
1260         return service_loop(&socklist);
1261 }
1262
1263 int cmd_main(int argc, const char **argv)
1264 {
1265         int listen_port = 0;
1266         struct string_list listen_addr = STRING_LIST_INIT_NODUP;
1267         int serve_mode = 0, inetd_mode = 0;
1268         const char *pid_file = NULL, *user_name = NULL, *group_name = NULL;
1269         int detach = 0;
1270         struct credentials *cred = NULL;
1271         int i;
1272
1273         for (i = 1; i < argc; i++) {
1274                 const char *arg = argv[i];
1275                 const char *v;
1276
1277                 if (skip_prefix(arg, "--listen=", &v)) {
1278                         string_list_append(&listen_addr, xstrdup_tolower(v));
1279                         continue;
1280                 }
1281                 if (skip_prefix(arg, "--port=", &v)) {
1282                         char *end;
1283                         unsigned long n;
1284                         n = strtoul(v, &end, 0);
1285                         if (*v && !*end) {
1286                                 listen_port = n;
1287                                 continue;
1288                         }
1289                 }
1290                 if (!strcmp(arg, "--serve")) {
1291                         serve_mode = 1;
1292                         continue;
1293                 }
1294                 if (!strcmp(arg, "--inetd")) {
1295                         inetd_mode = 1;
1296                         continue;
1297                 }
1298                 if (!strcmp(arg, "--verbose")) {
1299                         verbose = 1;
1300                         continue;
1301                 }
1302                 if (!strcmp(arg, "--syslog")) {
1303                         log_destination = LOG_DESTINATION_SYSLOG;
1304                         continue;
1305                 }
1306                 if (skip_prefix(arg, "--log-destination=", &v)) {
1307                         if (!strcmp(v, "syslog")) {
1308                                 log_destination = LOG_DESTINATION_SYSLOG;
1309                                 continue;
1310                         } else if (!strcmp(v, "stderr")) {
1311                                 log_destination = LOG_DESTINATION_STDERR;
1312                                 continue;
1313                         } else if (!strcmp(v, "none")) {
1314                                 log_destination = LOG_DESTINATION_NONE;
1315                                 continue;
1316                         } else
1317                                 die("unknown log destination '%s'", v);
1318                 }
1319                 if (!strcmp(arg, "--export-all")) {
1320                         export_all_trees = 1;
1321                         continue;
1322                 }
1323                 if (skip_prefix(arg, "--access-hook=", &v)) {
1324                         access_hook = v;
1325                         continue;
1326                 }
1327                 if (skip_prefix(arg, "--timeout=", &v)) {
1328                         timeout = atoi(v);
1329                         continue;
1330                 }
1331                 if (skip_prefix(arg, "--init-timeout=", &v)) {
1332                         init_timeout = atoi(v);
1333                         continue;
1334                 }
1335                 if (skip_prefix(arg, "--max-connections=", &v)) {
1336                         max_connections = atoi(v);
1337                         if (max_connections < 0)
1338                                 max_connections = 0;            /* unlimited */
1339                         continue;
1340                 }
1341                 if (!strcmp(arg, "--strict-paths")) {
1342                         strict_paths = 1;
1343                         continue;
1344                 }
1345                 if (skip_prefix(arg, "--base-path=", &v)) {
1346                         base_path = v;
1347                         continue;
1348                 }
1349                 if (!strcmp(arg, "--base-path-relaxed")) {
1350                         base_path_relaxed = 1;
1351                         continue;
1352                 }
1353                 if (skip_prefix(arg, "--interpolated-path=", &v)) {
1354                         interpolated_path = v;
1355                         continue;
1356                 }
1357                 if (!strcmp(arg, "--reuseaddr")) {
1358                         reuseaddr = 1;
1359                         continue;
1360                 }
1361                 if (!strcmp(arg, "--user-path")) {
1362                         user_path = "";
1363                         continue;
1364                 }
1365                 if (skip_prefix(arg, "--user-path=", &v)) {
1366                         user_path = v;
1367                         continue;
1368                 }
1369                 if (skip_prefix(arg, "--pid-file=", &v)) {
1370                         pid_file = v;
1371                         continue;
1372                 }
1373                 if (!strcmp(arg, "--detach")) {
1374                         detach = 1;
1375                         continue;
1376                 }
1377                 if (skip_prefix(arg, "--user=", &v)) {
1378                         user_name = v;
1379                         continue;
1380                 }
1381                 if (skip_prefix(arg, "--group=", &v)) {
1382                         group_name = v;
1383                         continue;
1384                 }
1385                 if (skip_prefix(arg, "--enable=", &v)) {
1386                         enable_service(v, 1);
1387                         continue;
1388                 }
1389                 if (skip_prefix(arg, "--disable=", &v)) {
1390                         enable_service(v, 0);
1391                         continue;
1392                 }
1393                 if (skip_prefix(arg, "--allow-override=", &v)) {
1394                         make_service_overridable(v, 1);
1395                         continue;
1396                 }
1397                 if (skip_prefix(arg, "--forbid-override=", &v)) {
1398                         make_service_overridable(v, 0);
1399                         continue;
1400                 }
1401                 if (!strcmp(arg, "--informative-errors")) {
1402                         informative_errors = 1;
1403                         continue;
1404                 }
1405                 if (!strcmp(arg, "--no-informative-errors")) {
1406                         informative_errors = 0;
1407                         continue;
1408                 }
1409                 if (!strcmp(arg, "--")) {
1410                         ok_paths = &argv[i+1];
1411                         break;
1412                 } else if (arg[0] != '-') {
1413                         ok_paths = &argv[i];
1414                         break;
1415                 }
1416
1417                 usage(daemon_usage);
1418         }
1419
1420         if (log_destination == LOG_DESTINATION_UNSET) {
1421                 if (inetd_mode || detach)
1422                         log_destination = LOG_DESTINATION_SYSLOG;
1423                 else
1424                         log_destination = LOG_DESTINATION_STDERR;
1425         }
1426
1427         if (log_destination == LOG_DESTINATION_SYSLOG) {
1428                 openlog("git-daemon", LOG_PID, LOG_DAEMON);
1429                 set_die_routine(daemon_die);
1430         } else
1431                 /* avoid splitting a message in the middle */
1432                 setvbuf(stderr, NULL, _IOFBF, 4096);
1433
1434         if (inetd_mode && (detach || group_name || user_name))
1435                 die("--detach, --user and --group are incompatible with --inetd");
1436
1437         if (inetd_mode && (listen_port || (listen_addr.nr > 0)))
1438                 die("--listen= and --port= are incompatible with --inetd");
1439         else if (listen_port == 0)
1440                 listen_port = DEFAULT_GIT_PORT;
1441
1442         if (group_name && !user_name)
1443                 die("--group supplied without --user");
1444
1445         if (user_name)
1446                 cred = prepare_credentials(user_name, group_name);
1447
1448         if (strict_paths && (!ok_paths || !*ok_paths))
1449                 die("option --strict-paths requires '<directory>' arguments");
1450
1451         if (base_path && !is_directory(base_path))
1452                 die("base-path '%s' does not exist or is not a directory",
1453                     base_path);
1454
1455         if (log_destination != LOG_DESTINATION_STDERR) {
1456                 if (!freopen("/dev/null", "w", stderr))
1457                         die_errno("failed to redirect stderr to /dev/null");
1458         }
1459
1460         if (inetd_mode || serve_mode)
1461                 return execute();
1462
1463         if (detach) {
1464                 if (daemonize())
1465                         die("--detach not supported on this platform");
1466         }
1467
1468         if (pid_file)
1469                 write_file(pid_file, "%"PRIuMAX, (uintmax_t) getpid());
1470
1471         /* prepare argv for serving-processes */
1472         strvec_push(&cld_argv, argv[0]); /* git-daemon */
1473         strvec_push(&cld_argv, "--serve");
1474         for (i = 1; i < argc; ++i)
1475                 strvec_push(&cld_argv, argv[i]);
1476
1477         return serve(&listen_addr, listen_port, cred);
1478 }