source4/smbd/server.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    Main SMB server routines
   5
   6    Copyright (C) Andrew Tridgell                1992-2005
   7    Copyright (C) Martin Pool                    2002
   8    Copyright (C) Jelmer Vernooij                2002
   9    Copyright (C) James J Myers                  2003 <myersjj@samba.org>
  10
  11    This program is free software; you can redistribute it and/or modify
  12    it under the terms of the GNU General Public License as published by
  13    the Free Software Foundation; either version 3 of the License, or
  14    (at your option) any later version.
  15
  16    This program is distributed in the hope that it will be useful,
  17    but WITHOUT ANY WARRANTY; without even the implied warranty of
  18    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19    GNU General Public License for more details.
  20
  21    You should have received a copy of the GNU General Public License
  22    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  23 */
  24
  25 #include "includes.h"
  26 #include "lib/events/events.h"
  27 #include "version.h"
  28 #include "lib/cmdline/popt_common.h"
  29 #include "system/dir.h"
  30 #include "system/filesys.h"
  31 #include "auth/gensec/gensec.h"
  32 #include "libcli/auth/schannel.h"
  33 #include "smbd/process_model.h"
  34 #include "param/secrets.h"
  35 #include "lib/util/pidfile.h"
  36 #include "param/param.h"
  37 #include "dsdb/samdb/samdb.h"
  38 #include "auth/session.h"
  39 #include "lib/messaging/irpc.h"
  40 #include "librpc/gen_ndr/ndr_irpc.h"
  41 #include "cluster/cluster.h"
  42 #include "dynconfig/dynconfig.h"
  43 #include "lib/util/samba_modules.h"
  44 #include "nsswitch/winbind_client.h"
  45 #include "libds/common/roles.h"
  46
  47 /*
  48   recursively delete a directory tree
  49 */
  50 static void recursive_delete(const char *path)
  51 {
  52         DIR *dir;
  53         struct dirent *de;
  54
  55         dir = opendir(path);
  56         if (!dir) {
  57                 return;
  58         }
  59
  60         for (de=readdir(dir);de;de=readdir(dir)) {
  61                 char *fname;
  62                 struct stat st;
  63
  64                 if (ISDOT(de->d_name) || ISDOTDOT(de->d_name)) {
  65                         continue;
  66                 }
  67
  68                 fname = talloc_asprintf(path, "%s/%s", path, de->d_name);
  69                 if (stat(fname, &st) != 0) {
  70                         continue;
  71                 }
  72                 if (S_ISDIR(st.st_mode)) {
  73                         recursive_delete(fname);
  74                         talloc_free(fname);
  75                         continue;
  76                 }
  77                 if (unlink(fname) != 0) {
  78                         DEBUG(0,("Unabled to delete '%s' - %s\n",
  79                                  fname, strerror(errno)));
  80                         smb_panic("unable to cleanup tmp files");
  81                 }
  82                 talloc_free(fname);
  83         }
  84         closedir(dir);
  85 }
  86
  87 /*
  88   cleanup temporary files. This is the new alternative to
  89   TDB_CLEAR_IF_FIRST. Unfortunately TDB_CLEAR_IF_FIRST is not
  90   efficient on unix systems due to the lack of scaling of the byte
  91   range locking system. So instead of putting the burden on tdb to
  92   cleanup tmp files, this function deletes them.
  93 */
  94 static void cleanup_tmp_files(struct loadparm_context *lp_ctx)
  95 {
  96         char *path;
  97         TALLOC_CTX *mem_ctx = talloc_new(NULL);
  98
  99         path = smbd_tmp_path(mem_ctx, lp_ctx, NULL);
 100
 101         recursive_delete(path);
 102         talloc_free(mem_ctx);
 103 }
 104
 105 static void sig_hup(int sig)
 106 {
 107         debug_schedule_reopen_logs();
 108 }
 109
 110 static void sig_term(int sig)
 111 {
 112 #if HAVE_GETPGRP
 113         static int done_sigterm;
 114         if (done_sigterm == 0 && getpgrp() == getpid()) {
 115                 DEBUG(0,("SIGTERM: killing children\n"));
 116                 done_sigterm = 1;
 117                 kill(-getpgrp(), SIGTERM);
 118         }
 119 #endif
 120         DEBUG(0,("Exiting pid %d on SIGTERM\n", (int)getpid()));
 121         exit(127);
 122 }
 123
 124 /*
 125   setup signal masks
 126 */
 127 static void setup_signals(void)
 128 {
 129         /* we are never interested in SIGPIPE */
 130         BlockSignals(true,SIGPIPE);
 131
 132 #if defined(SIGFPE)
 133         /* we are never interested in SIGFPE */
 134         BlockSignals(true,SIGFPE);
 135 #endif
 136
 137         /* We are no longer interested in USR1 */
 138         BlockSignals(true, SIGUSR1);
 139
 140 #if defined(SIGUSR2)
 141         /* We are no longer interested in USR2 */
 142         BlockSignals(true,SIGUSR2);
 143 #endif
 144
 145         /* POSIX demands that signals are inherited. If the invoking process has
 146          * these signals masked, we will have problems, as we won't receive them. */
 147         BlockSignals(false, SIGHUP);
 148         BlockSignals(false, SIGTERM);
 149
 150         CatchSignal(SIGHUP, sig_hup);
 151         CatchSignal(SIGTERM, sig_term);
 152 }
 153
 154 /*
 155   handle io on stdin
 156 */
 157 static void server_stdin_handler(struct tevent_context *event_ctx, struct tevent_fd *fde,
 158                                  uint16_t flags, void *private_data)
 159 {
 160         const char *binary_name = (const char *)private_data;
 161         uint8_t c;
 162         if (read(0, &c, 1) == 0) {
 163                 DEBUG(0,("%s: EOF on stdin - PID %d terminating\n", binary_name, (int)getpid()));
 164 #if HAVE_GETPGRP
 165                 if (getpgrp() == getpid()) {
 166                         DEBUG(0,("Sending SIGTERM from pid %d\n", (int)getpid()));
 167                         kill(-getpgrp(), SIGTERM);
 168                 }
 169 #endif
 170                 exit(0);
 171         }
 172 }
 173
 174 /*
 175   die if the user selected maximum runtime is exceeded
 176 */
 177 _NORETURN_ static void max_runtime_handler(struct tevent_context *ev,
 178                                            struct tevent_timer *te,
 179                                            struct timeval t, void *private_data)
 180 {
 181         const char *binary_name = (const char *)private_data;
 182         DEBUG(0,("%s: maximum runtime exceeded - terminating PID %d at %llu, current ts: %llu\n",
 183                  binary_name, (int)getpid(), (unsigned long long)t.tv_sec, (unsigned long long) time(NULL)));
 184         exit(0);
 185 }
 186
 187 /*
 188   pre-open the key databases. This saves a lot of time in child
 189   processes
 190  */
 191 static void prime_ldb_databases(struct tevent_context *event_ctx)
 192 {
 193         TALLOC_CTX *db_context;
 194         db_context = talloc_new(event_ctx);
 195
 196         samdb_connect(db_context, event_ctx, cmdline_lp_ctx, system_session(cmdline_lp_ctx), 0);
 197         privilege_connect(db_context, cmdline_lp_ctx);
 198
 199         /* we deliberately leave these open, which allows them to be
 200          * re-used in ldb_wrap_connect() */
 201 }
 202
 203
 204 /*
 205   called when a fatal condition occurs in a child task
 206  */
 207 static NTSTATUS samba_terminate(struct irpc_message *msg,
 208                                 struct samba_terminate *r)
 209 {
 210         DEBUG(0,("samba_terminate of %d: %s\n",
 211                  (int)getpid(), r->in.reason));
 212         exit(1);
 213 }
 214
 215 /*
 216   setup messaging for the top level samba (parent) task
 217  */
 218 static NTSTATUS setup_parent_messaging(struct tevent_context *event_ctx,
 219                                        struct loadparm_context *lp_ctx)
 220 {
 221         struct imessaging_context *msg;
 222         NTSTATUS status;
 223
 224         msg = imessaging_init(talloc_autofree_context(),
 225                               lp_ctx,
 226                               cluster_id(0, SAMBA_PARENT_TASKID), event_ctx);
 227         NT_STATUS_HAVE_NO_MEMORY(msg);
 228
 229         status = irpc_add_name(msg, "samba");
 230         if (!NT_STATUS_IS_OK(status)) {
 231                 return status;
 232         }
 233
 234         status = IRPC_REGISTER(msg, irpc, SAMBA_TERMINATE,
 235                                samba_terminate, NULL);
 236
 237         return status;
 238 }
 239
 240
 241 /*
 242   show build info
 243  */
 244 static void show_build(void)
 245 {
 246 #define CONFIG_OPTION(n) { #n, dyn_ ## n }
 247         struct {
 248                 const char *name;
 249                 const char *value;
 250         } config_options[] = {
 251                 CONFIG_OPTION(BINDIR),
 252                 CONFIG_OPTION(SBINDIR),
 253                 CONFIG_OPTION(CONFIGFILE),
 254                 CONFIG_OPTION(NCALRPCDIR),
 255                 CONFIG_OPTION(LOGFILEBASE),
 256                 CONFIG_OPTION(LMHOSTSFILE),
 257                 CONFIG_OPTION(DATADIR),
 258                 CONFIG_OPTION(MODULESDIR),
 259                 CONFIG_OPTION(LOCKDIR),
 260                 CONFIG_OPTION(STATEDIR),
 261                 CONFIG_OPTION(CACHEDIR),
 262                 CONFIG_OPTION(PIDDIR),
 263                 CONFIG_OPTION(PRIVATE_DIR),
 264                 CONFIG_OPTION(CODEPAGEDIR),
 265                 CONFIG_OPTION(SETUPDIR),
 266                 CONFIG_OPTION(WINBINDD_SOCKET_DIR),
 267                 CONFIG_OPTION(NTP_SIGND_SOCKET_DIR),
 268                 { NULL, NULL}
 269         };
 270         int i;
 271
 272         printf("Samba version: %s\n", SAMBA_VERSION_STRING);
 273         printf("Build environment:\n");
 274 #ifdef BUILD_SYSTEM
 275         printf("   Build host:  %s\n", BUILD_SYSTEM);
 276 #endif
 277
 278         printf("Paths:\n");
 279         for (i=0; config_options[i].name; i++) {
 280                 printf("   %s: %s\n", config_options[i].name, config_options[i].value);
 281         }
 282
 283         exit(0);
 284 }
 285
 286 static int event_ctx_destructor(struct tevent_context *event_ctx)
 287 {
 288         imessaging_dgm_unref_all();
 289         return 0;
 290 }
 291
 292 /*
 293  main server.
 294 */
 295 static int binary_smbd_main(const char *binary_name, int argc, const char *argv[])
 296 {
 297         bool opt_daemon = false;
 298         bool opt_interactive = false;
 299         int opt;
 300         poptContext pc;
 301 #define _MODULE_PROTO(init) extern NTSTATUS init(void);
 302         STATIC_service_MODULES_PROTO;
 303         init_module_fn static_init[] = { STATIC_service_MODULES };
 304         init_module_fn *shared_init;
 305         struct tevent_context *event_ctx;
 306         uint16_t stdin_event_flags;
 307         NTSTATUS status;
 308         const char *model = "standard";
 309         int max_runtime = 0;
 310         struct stat st;
 311         enum {
 312                 OPT_DAEMON = 1000,
 313                 OPT_INTERACTIVE,
 314                 OPT_PROCESS_MODEL,
 315                 OPT_SHOW_BUILD
 316         };
 317         struct poptOption long_options[] = {
 318                 POPT_AUTOHELP
 319                 {"daemon", 'D', POPT_ARG_NONE, NULL, OPT_DAEMON,
 320                  "Become a daemon (default)", NULL },
 321                 {"interactive", 'i', POPT_ARG_NONE, NULL, OPT_INTERACTIVE,
 322                  "Run interactive (not a daemon)", NULL},
 323                 {"model", 'M', POPT_ARG_STRING, NULL, OPT_PROCESS_MODEL,
 324                  "Select process model", "MODEL"},
 325                 {"maximum-runtime",0, POPT_ARG_INT, &max_runtime, 0,
 326                  "set maximum runtime of the server process, till autotermination", "seconds"},
 327                 {"show-build", 'b', POPT_ARG_NONE, NULL, OPT_SHOW_BUILD, "show build info", NULL },
 328                 POPT_COMMON_SAMBA
 329                 POPT_COMMON_VERSION
 330                 { NULL }
 331         };
 332
 333         pc = poptGetContext(binary_name, argc, argv, long_options, 0);
 334         while((opt = poptGetNextOpt(pc)) != -1) {
 335                 switch(opt) {
 336                 case OPT_DAEMON:
 337                         opt_daemon = true;
 338                         break;
 339                 case OPT_INTERACTIVE:
 340                         opt_interactive = true;
 341                         break;
 342                 case OPT_PROCESS_MODEL:
 343                         model = poptGetOptArg(pc);
 344                         break;
 345                 case OPT_SHOW_BUILD:
 346                         show_build();
 347                         break;
 348                 default:
 349                         fprintf(stderr, "\nInvalid option %s: %s\n\n",
 350                                   poptBadOption(pc, 0), poptStrerror(opt));
 351                         poptPrintUsage(pc, stderr, 0);
 352                         return 1;
 353                 }
 354         }
 355
 356         if (opt_daemon && opt_interactive) {
 357                 fprintf(stderr,"\nERROR: "
 358                           "Option -i|--interactive is not allowed together with -D|--daemon\n\n");
 359                 poptPrintUsage(pc, stderr, 0);
 360                 return 1;
 361         } else if (!opt_interactive) {
 362                 /* default is --daemon */
 363                 opt_daemon = true;
 364         }
 365
 366         poptFreeContext(pc);
 367
 368         talloc_enable_null_tracking();
 369
 370         setup_logging(binary_name, opt_interactive?DEBUG_STDOUT:DEBUG_FILE);
 371         setup_signals();
 372
 373         /* we want total control over the permissions on created files,
 374            so set our umask to 0 */
 375         umask(0);
 376
 377         DEBUG(0,("%s version %s started.\n", binary_name, SAMBA_VERSION_STRING));
 378         DEBUGADD(0,("Copyright Andrew Tridgell and the Samba Team 1992-2017\n"));
 379
 380         if (sizeof(uint16_t) < 2 || sizeof(uint32_t) < 4 || sizeof(uint64_t) < 8) {
 381                 DEBUG(0,("ERROR: Samba is not configured correctly for the word size on your machine\n"));
 382                 DEBUGADD(0,("sizeof(uint16_t) = %u, sizeof(uint32_t) %u, sizeof(uint64_t) = %u\n",
 383                             (unsigned int)sizeof(uint16_t), (unsigned int)sizeof(uint32_t), (unsigned int)sizeof(uint64_t)));
 384                 return 1;
 385         }
 386
 387         if (opt_daemon) {
 388                 DEBUG(3,("Becoming a daemon.\n"));
 389                 become_daemon(true, false, false);
 390         }
 391
 392         cleanup_tmp_files(cmdline_lp_ctx);
 393
 394         if (!directory_exist(lpcfg_lock_directory(cmdline_lp_ctx))) {
 395                 mkdir(lpcfg_lock_directory(cmdline_lp_ctx), 0755);
 396         }
 397
 398         pidfile_create(lpcfg_pid_directory(cmdline_lp_ctx), binary_name);
 399
 400         if (lpcfg_server_role(cmdline_lp_ctx) == ROLE_ACTIVE_DIRECTORY_DC) {
 401                 if (!open_schannel_session_store(talloc_autofree_context(), cmdline_lp_ctx)) {
 402                         exit_daemon("Samba cannot open schannel store for secured NETLOGON operations.", EACCES);
 403                 }
 404         }
 405
 406         /* make sure we won't go through nss_winbind */
 407         if (!winbind_off()) {
 408                 exit_daemon("Samba failed to disable recusive winbindd calls.", EACCES);
 409         }
 410
 411         gensec_init(); /* FIXME: */
 412
 413         process_model_init(cmdline_lp_ctx);
 414
 415         shared_init = load_samba_modules(NULL, "service");
 416
 417         run_init_functions(static_init);
 418         run_init_functions(shared_init);
 419
 420         talloc_free(shared_init);
 421
 422         /* the event context is the top level structure in smbd. Everything else
 423            should hang off that */
 424         event_ctx = s4_event_context_init(talloc_autofree_context());
 425
 426         if (event_ctx == NULL) {
 427                 exit_daemon("Initializing event context failed", EACCES);
 428         }
 429
 430         talloc_set_destructor(event_ctx, event_ctx_destructor);
 431
 432         if (opt_interactive) {
 433                 /* terminate when stdin goes away */
 434                 stdin_event_flags = TEVENT_FD_READ;
 435         } else {
 436                 /* stay alive forever */
 437                 stdin_event_flags = 0;
 438         }
 439
 440         /* catch EOF on stdin */
 441 #ifdef SIGTTIN
 442         signal(SIGTTIN, SIG_IGN);
 443 #endif
 444
 445         if (fstat(0, &st) != 0) {
 446                 exit_daemon("Samba failed to set standard input handler", ENOTTY);
 447         }
 448
 449         if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode)) {
 450                 tevent_add_fd(event_ctx,
 451                                 event_ctx,
 452                                 0,
 453                                 stdin_event_flags,
 454                                 server_stdin_handler,
 455                                 discard_const(binary_name));
 456         }
 457
 458         if (max_runtime) {
 459                 DEBUG(0,("%s PID %d was called with maxruntime %d - current ts %llu\n",
 460                          binary_name, (int)getpid(),
 461                          max_runtime, (unsigned long long) time(NULL)));
 462                 tevent_add_timer(event_ctx, event_ctx,
 463                                  timeval_current_ofs(max_runtime, 0),
 464                                  max_runtime_handler,
 465                                  discard_const(binary_name));
 466         }
 467
 468         if (lpcfg_server_role(cmdline_lp_ctx) != ROLE_ACTIVE_DIRECTORY_DC
 469             && !lpcfg_parm_bool(cmdline_lp_ctx, NULL, "server role check", "inhibit", false)
 470             && !str_list_check_ci(lpcfg_server_services(cmdline_lp_ctx), "smb")
 471             && !str_list_check_ci(lpcfg_dcerpc_endpoint_servers(cmdline_lp_ctx), "remote")
 472             && !str_list_check_ci(lpcfg_dcerpc_endpoint_servers(cmdline_lp_ctx), "mapiproxy")) {
 473                 DEBUG(0, ("At this time the 'samba' binary should only be used for either:\n"));
 474                 DEBUGADD(0, ("'server role = active directory domain controller' or to access the ntvfs file server with 'server services = +smb' or the rpc proxy with 'dcerpc endpoint servers = remote'\n"));
 475                 DEBUGADD(0, ("You should start smbd/nmbd/winbindd instead for domain member and standalone file server tasks\n"));
 476                 exit_daemon("Samba detected misconfigured 'server role' and exited. Check logs for details", EINVAL);
 477         };
 478
 479         prime_ldb_databases(event_ctx);
 480
 481         status = setup_parent_messaging(event_ctx, cmdline_lp_ctx);
 482         if (!NT_STATUS_IS_OK(status)) {
 483                 exit_daemon("Samba failed to setup parent messaging", NT_STATUS_V(status));
 484         }
 485
 486         DEBUG(0,("%s: using '%s' process model\n", binary_name, model));
 487
 488         status = server_service_startup(event_ctx, cmdline_lp_ctx, model,
 489                                         lpcfg_server_services(cmdline_lp_ctx));
 490         if (!NT_STATUS_IS_OK(status)) {
 491                 exit_daemon("Samba failed to start services", NT_STATUS_V(status));
 492         }
 493
 494         if (opt_daemon) {
 495                 daemon_ready("samba");
 496         }
 497
 498         /* wait for events - this is where smbd sits for most of its
 499            life */
 500         tevent_loop_wait(event_ctx);
 501
 502         /* as everything hangs off this event context, freeing it
 503            should initiate a clean shutdown of all services */
 504         talloc_free(event_ctx);
 505
 506         return 0;
 507 }
 508
 509 int main(int argc, const char *argv[])
 510 {
 511         return binary_smbd_main("samba", argc, argv);
 512 }