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