Fix denial of service - memory corruption.
[samba.git] / source3 / winbindd / winbindd.c
1 /* 
2    Unix SMB/CIFS implementation.
3
4    Winbind daemon for ntdom nss module
5
6    Copyright (C) by Tim Potter 2000-2002
7    Copyright (C) Andrew Tridgell 2002
8    Copyright (C) Jelmer Vernooij 2003
9    Copyright (C) Volker Lendecke 2004
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 "winbindd.h"
27
28 #undef DBGC_CLASS
29 #define DBGC_CLASS DBGC_WINBIND
30
31 static bool opt_nocache = False;
32 static bool interactive = False;
33
34 extern bool override_logfile;
35
36 struct event_context *winbind_event_context(void)
37 {
38         static struct event_context *ctx;
39
40         if (!ctx && !(ctx = event_context_init(NULL))) {
41                 smb_panic("Could not init winbind event context");
42         }
43         return ctx;
44 }
45
46 struct messaging_context *winbind_messaging_context(void)
47 {
48         static struct messaging_context *ctx;
49
50         if (ctx == NULL) {
51                 ctx = messaging_init(NULL, server_id_self(),
52                                      winbind_event_context());
53         }
54         if (ctx == NULL) {
55                 DEBUG(0, ("Could not init winbind messaging context.\n"));
56         }
57         return ctx;
58 }
59
60 /* Reload configuration */
61
62 static bool reload_services_file(const char *lfile)
63 {
64         bool ret;
65
66         if (lp_loaded()) {
67                 const char *fname = lp_configfile();
68
69                 if (file_exist(fname) && !strcsequal(fname,get_dyn_CONFIGFILE())) {
70                         set_dyn_CONFIGFILE(fname);
71                 }
72         }
73
74         /* if this is a child, restore the logfile to the special
75            name - <domain>, idmap, etc. */
76         if (lfile && *lfile) {
77                 lp_set_logfile(lfile);
78         }
79
80         reopen_logs();
81         ret = lp_load(get_dyn_CONFIGFILE(),False,False,True,True);
82
83         reopen_logs();
84         load_interfaces();
85
86         return(ret);
87 }
88
89
90 /**************************************************************************** **
91  Handle a fault..
92  **************************************************************************** */
93
94 static void fault_quit(void)
95 {
96         dump_core();
97 }
98
99 static void winbindd_status(void)
100 {
101         struct winbindd_cli_state *tmp;
102
103         DEBUG(0, ("winbindd status:\n"));
104
105         /* Print client state information */
106
107         DEBUG(0, ("\t%d clients currently active\n", winbindd_num_clients()));
108
109         if (DEBUGLEVEL >= 2 && winbindd_num_clients()) {
110                 DEBUG(2, ("\tclient list:\n"));
111                 for(tmp = winbindd_client_list(); tmp; tmp = tmp->next) {
112                         DEBUGADD(2, ("\t\tpid %lu, sock %d\n",
113                                   (unsigned long)tmp->pid, tmp->sock));
114                 }
115         }
116 }
117
118 /* Print winbindd status to log file */
119
120 static void print_winbindd_status(void)
121 {
122         winbindd_status();
123 }
124
125 /* Flush client cache */
126
127 static void flush_caches(void)
128 {
129         /* We need to invalidate cached user list entries on a SIGHUP 
130            otherwise cached access denied errors due to restrict anonymous
131            hang around until the sequence number changes. */
132
133         if (!wcache_invalidate_cache()) {
134                 DEBUG(0, ("invalidating the cache failed; revalidate the cache\n"));
135                 if (!winbindd_cache_validate_and_initialize()) {
136                         exit(1);
137                 }
138         }
139 }
140
141 /* Handle the signal by unlinking socket and exiting */
142
143 static void terminate(bool is_parent)
144 {
145         if (is_parent) {
146                 /* When parent goes away we should
147                  * remove the socket file. Not so
148                  * when children terminate.
149                  */ 
150                 char *path = NULL;
151
152                 if (asprintf(&path, "%s/%s",
153                         get_winbind_pipe_dir(), WINBINDD_SOCKET_NAME) > 0) {
154                         unlink(path);
155                         SAFE_FREE(path);
156                 }
157         }
158
159         idmap_close();
160
161         trustdom_cache_shutdown();
162
163 #if 0
164         if (interactive) {
165                 TALLOC_CTX *mem_ctx = talloc_init("end_description");
166                 char *description = talloc_describe_all(mem_ctx);
167
168                 DEBUG(3, ("tallocs left:\n%s\n", description));
169                 talloc_destroy(mem_ctx);
170         }
171 #endif
172
173         if (is_parent) {
174                 pidfile_unlink();
175         }
176
177         exit(0);
178 }
179
180 static void winbindd_sig_term_handler(struct tevent_context *ev,
181                                       struct tevent_signal *se,
182                                       int signum,
183                                       int count,
184                                       void *siginfo,
185                                       void *private_data)
186 {
187         bool *is_parent = talloc_get_type_abort(private_data, bool);
188
189         DEBUG(0,("Got sig[%d] terminate (is_parent=%d)\n",
190                  signum, (int)*is_parent));
191         terminate(*is_parent);
192 }
193
194 bool winbindd_setup_sig_term_handler(bool parent)
195 {
196         struct tevent_signal *se;
197         bool *is_parent;
198
199         is_parent = talloc(winbind_event_context(), bool);
200         if (!is_parent) {
201                 return false;
202         }
203
204         *is_parent = parent;
205
206         se = tevent_add_signal(winbind_event_context(),
207                                is_parent,
208                                SIGTERM, 0,
209                                winbindd_sig_term_handler,
210                                is_parent);
211         if (!se) {
212                 DEBUG(0,("failed to setup SIGTERM handler"));
213                 talloc_free(is_parent);
214                 return false;
215         }
216
217         se = tevent_add_signal(winbind_event_context(),
218                                is_parent,
219                                SIGINT, 0,
220                                winbindd_sig_term_handler,
221                                is_parent);
222         if (!se) {
223                 DEBUG(0,("failed to setup SIGINT handler"));
224                 talloc_free(is_parent);
225                 return false;
226         }
227
228         se = tevent_add_signal(winbind_event_context(),
229                                is_parent,
230                                SIGQUIT, 0,
231                                winbindd_sig_term_handler,
232                                is_parent);
233         if (!se) {
234                 DEBUG(0,("failed to setup SIGINT handler"));
235                 talloc_free(is_parent);
236                 return false;
237         }
238
239         return true;
240 }
241
242 static void winbindd_sig_hup_handler(struct tevent_context *ev,
243                                      struct tevent_signal *se,
244                                      int signum,
245                                      int count,
246                                      void *siginfo,
247                                      void *private_data)
248 {
249         const char *file = (const char *)private_data;
250
251         DEBUG(1,("Reloading services after SIGHUP\n"));
252         flush_caches();
253         reload_services_file(file);
254 }
255
256 bool winbindd_setup_sig_hup_handler(const char *lfile)
257 {
258         struct tevent_signal *se;
259         char *file = NULL;
260
261         if (lfile) {
262                 file = talloc_strdup(winbind_event_context(),
263                                      lfile);
264                 if (!file) {
265                         return false;
266                 }
267         }
268
269         se = tevent_add_signal(winbind_event_context(),
270                                winbind_event_context(),
271                                SIGHUP, 0,
272                                winbindd_sig_hup_handler,
273                                file);
274         if (!se) {
275                 return false;
276         }
277
278         return true;
279 }
280
281 static void winbindd_sig_chld_handler(struct tevent_context *ev,
282                                       struct tevent_signal *se,
283                                       int signum,
284                                       int count,
285                                       void *siginfo,
286                                       void *private_data)
287 {
288         pid_t pid;
289
290         while ((pid = sys_waitpid(-1, NULL, WNOHANG)) > 0) {
291                 winbind_child_died(pid);
292         }
293 }
294
295 static bool winbindd_setup_sig_chld_handler(void)
296 {
297         struct tevent_signal *se;
298
299         se = tevent_add_signal(winbind_event_context(),
300                                winbind_event_context(),
301                                SIGCHLD, 0,
302                                winbindd_sig_chld_handler,
303                                NULL);
304         if (!se) {
305                 return false;
306         }
307
308         return true;
309 }
310
311 static void winbindd_sig_usr2_handler(struct tevent_context *ev,
312                                       struct tevent_signal *se,
313                                       int signum,
314                                       int count,
315                                       void *siginfo,
316                                       void *private_data)
317 {
318         print_winbindd_status();
319 }
320
321 static bool winbindd_setup_sig_usr2_handler(void)
322 {
323         struct tevent_signal *se;
324
325         se = tevent_add_signal(winbind_event_context(),
326                                winbind_event_context(),
327                                SIGUSR2, 0,
328                                winbindd_sig_usr2_handler,
329                                NULL);
330         if (!se) {
331                 return false;
332         }
333
334         return true;
335 }
336
337 /* React on 'smbcontrol winbindd reload-config' in the same way as on SIGHUP*/
338 static void msg_reload_services(struct messaging_context *msg,
339                                 void *private_data,
340                                 uint32_t msg_type,
341                                 struct server_id server_id,
342                                 DATA_BLOB *data)
343 {
344         /* Flush various caches */
345         flush_caches();
346         reload_services_file((const char *) private_data);
347 }
348
349 /* React on 'smbcontrol winbindd shutdown' in the same way as on SIGTERM*/
350 static void msg_shutdown(struct messaging_context *msg,
351                          void *private_data,
352                          uint32_t msg_type,
353                          struct server_id server_id,
354                          DATA_BLOB *data)
355 {
356         /* only the parent waits for this message */
357         DEBUG(0,("Got shutdown message\n"));
358         terminate(true);
359 }
360
361
362 static void winbind_msg_validate_cache(struct messaging_context *msg_ctx,
363                                        void *private_data,
364                                        uint32_t msg_type,
365                                        struct server_id server_id,
366                                        DATA_BLOB *data)
367 {
368         uint8 ret;
369         pid_t child_pid;
370
371         DEBUG(10, ("winbindd_msg_validate_cache: got validate-cache "
372                    "message.\n"));
373
374         /*
375          * call the validation code from a child:
376          * so we don't block the main winbindd and the validation
377          * code can safely use fork/waitpid...
378          */
379         child_pid = sys_fork();
380
381         if (child_pid == -1) {
382                 DEBUG(1, ("winbind_msg_validate_cache: Could not fork: %s\n",
383                           strerror(errno)));
384                 return;
385         }
386
387         if (child_pid != 0) {
388                 /* parent */
389                 DEBUG(5, ("winbind_msg_validate_cache: child created with "
390                           "pid %d.\n", (int)child_pid));
391                 return;
392         }
393
394         /* child */
395
396         if (!winbindd_reinit_after_fork(NULL)) {
397                 _exit(0);
398         }
399
400         /* install default SIGCHLD handler: validation code uses fork/waitpid */
401         CatchSignal(SIGCHLD, SIG_DFL);
402
403         ret = (uint8)winbindd_validate_cache_nobackup();
404         DEBUG(10, ("winbindd_msg_validata_cache: got return value %d\n", ret));
405         messaging_send_buf(msg_ctx, server_id, MSG_WINBIND_VALIDATE_CACHE, &ret,
406                            (size_t)1);
407         _exit(0);
408 }
409
410 static struct winbindd_dispatch_table {
411         enum winbindd_cmd cmd;
412         void (*fn)(struct winbindd_cli_state *state);
413         const char *winbindd_cmd_name;
414 } dispatch_table[] = {
415
416         /* User functions */
417
418         { WINBINDD_GETPWNAM, winbindd_getpwnam, "GETPWNAM" },
419         { WINBINDD_GETPWUID, winbindd_getpwuid, "GETPWUID" },
420         { WINBINDD_GETPWSID, winbindd_getpwsid, "GETPWSID" },
421
422         { WINBINDD_SETPWENT, winbindd_setpwent, "SETPWENT" },
423         { WINBINDD_ENDPWENT, winbindd_endpwent, "ENDPWENT" },
424         { WINBINDD_GETPWENT, winbindd_getpwent, "GETPWENT" },
425
426         { WINBINDD_GETGROUPS, winbindd_getgroups, "GETGROUPS" },
427         { WINBINDD_GETUSERSIDS, winbindd_getusersids, "GETUSERSIDS" },
428         { WINBINDD_GETUSERDOMGROUPS, winbindd_getuserdomgroups,
429           "GETUSERDOMGROUPS" },
430         { WINBINDD_GETSIDALIASES, winbindd_getsidaliases,
431            "LOOKUPUSERALIASES" },
432
433         /* Group functions */
434
435         { WINBINDD_GETGRNAM, winbindd_getgrnam, "GETGRNAM" },
436         { WINBINDD_GETGRGID, winbindd_getgrgid, "GETGRGID" },
437         { WINBINDD_SETGRENT, winbindd_setgrent, "SETGRENT" },
438         { WINBINDD_ENDGRENT, winbindd_endgrent, "ENDGRENT" },
439         { WINBINDD_GETGRENT, winbindd_getgrent, "GETGRENT" },
440         { WINBINDD_GETGRLST, winbindd_getgrent, "GETGRLST" },
441
442         /* PAM auth functions */
443
444         { WINBINDD_PAM_AUTH, winbindd_pam_auth, "PAM_AUTH" },
445         { WINBINDD_PAM_AUTH_CRAP, winbindd_pam_auth_crap, "AUTH_CRAP" },
446         { WINBINDD_PAM_CHAUTHTOK, winbindd_pam_chauthtok, "CHAUTHTOK" },
447         { WINBINDD_PAM_LOGOFF, winbindd_pam_logoff, "PAM_LOGOFF" },
448         { WINBINDD_PAM_CHNG_PSWD_AUTH_CRAP, winbindd_pam_chng_pswd_auth_crap, "CHNG_PSWD_AUTH_CRAP" },
449
450         /* Enumeration functions */
451
452         { WINBINDD_LIST_USERS, winbindd_list_users, "LIST_USERS" },
453         { WINBINDD_LIST_GROUPS, winbindd_list_groups, "LIST_GROUPS" },
454         { WINBINDD_LIST_TRUSTDOM, winbindd_list_trusted_domains,
455           "LIST_TRUSTDOM" },
456         { WINBINDD_SHOW_SEQUENCE, winbindd_show_sequence, "SHOW_SEQUENCE" },
457
458         /* SID related functions */
459
460         { WINBINDD_LOOKUPSID, winbindd_lookupsid, "LOOKUPSID" },
461         { WINBINDD_LOOKUPNAME, winbindd_lookupname, "LOOKUPNAME" },
462         { WINBINDD_LOOKUPRIDS, winbindd_lookuprids, "LOOKUPRIDS" },
463
464         /* Lookup related functions */
465
466         { WINBINDD_SID_TO_UID, winbindd_sid_to_uid, "SID_TO_UID" },
467         { WINBINDD_SID_TO_GID, winbindd_sid_to_gid, "SID_TO_GID" },
468         { WINBINDD_UID_TO_SID, winbindd_uid_to_sid, "UID_TO_SID" },
469         { WINBINDD_GID_TO_SID, winbindd_gid_to_sid, "GID_TO_SID" },
470         { WINBINDD_ALLOCATE_UID, winbindd_allocate_uid, "ALLOCATE_UID" },
471         { WINBINDD_ALLOCATE_GID, winbindd_allocate_gid, "ALLOCATE_GID" },
472         { WINBINDD_SET_MAPPING, winbindd_set_mapping, "SET_MAPPING" },
473         { WINBINDD_REMOVE_MAPPING, winbindd_remove_mapping, "REMOVE_MAPPING" },
474         { WINBINDD_SET_HWM, winbindd_set_hwm, "SET_HWMS" },
475
476         /* Miscellaneous */
477
478         { WINBINDD_CHECK_MACHACC, winbindd_check_machine_acct, "CHECK_MACHACC" },
479         { WINBINDD_PING, winbindd_ping, "PING" },
480         { WINBINDD_INFO, winbindd_info, "INFO" },
481         { WINBINDD_INTERFACE_VERSION, winbindd_interface_version,
482           "INTERFACE_VERSION" },
483         { WINBINDD_DOMAIN_NAME, winbindd_domain_name, "DOMAIN_NAME" },
484         { WINBINDD_DOMAIN_INFO, winbindd_domain_info, "DOMAIN_INFO" },
485         { WINBINDD_NETBIOS_NAME, winbindd_netbios_name, "NETBIOS_NAME" },
486         { WINBINDD_PRIV_PIPE_DIR, winbindd_priv_pipe_dir,
487           "WINBINDD_PRIV_PIPE_DIR" },
488         { WINBINDD_GETDCNAME, winbindd_getdcname, "GETDCNAME" },
489         { WINBINDD_DSGETDCNAME, winbindd_dsgetdcname, "DSGETDCNAME" },
490
491         /* Credential cache access */
492         { WINBINDD_CCACHE_NTLMAUTH, winbindd_ccache_ntlm_auth, "NTLMAUTH" },
493
494         /* WINS functions */
495
496         { WINBINDD_WINS_BYNAME, winbindd_wins_byname, "WINS_BYNAME" },
497         { WINBINDD_WINS_BYIP, winbindd_wins_byip, "WINS_BYIP" },
498
499         /* End of list */
500
501         { WINBINDD_NUM_CMDS, NULL, "NONE" }
502 };
503
504 static void process_request(struct winbindd_cli_state *state)
505 {
506         struct winbindd_dispatch_table *table = dispatch_table;
507
508         /* Free response data - we may be interrupted and receive another
509            command before being able to send this data off. */
510
511         SAFE_FREE(state->response.extra_data.data);  
512
513         ZERO_STRUCT(state->response);
514
515         state->response.result = WINBINDD_PENDING;
516         state->response.length = sizeof(struct winbindd_response);
517
518         state->mem_ctx = talloc_init("winbind request");
519         if (state->mem_ctx == NULL)
520                 return;
521
522         /* Remember who asked us. */
523         state->pid = state->request.pid;
524
525         /* Process command */
526
527         for (table = dispatch_table; table->fn; table++) {
528                 if (state->request.cmd == table->cmd) {
529                         DEBUG(10,("process_request: request fn %s\n",
530                                   table->winbindd_cmd_name ));
531                         table->fn(state);
532                         break;
533                 }
534         }
535
536         if (!table->fn) {
537                 DEBUG(10,("process_request: unknown request fn number %d\n",
538                           (int)state->request.cmd ));
539                 request_error(state);
540         }
541 }
542
543 /*
544  * A list of file descriptors being monitored by select in the main processing
545  * loop. winbindd_fd_event->handler is called whenever the socket is readable/writable.
546  */
547
548 static struct winbindd_fd_event *fd_events = NULL;
549
550 void add_fd_event(struct winbindd_fd_event *ev)
551 {
552         struct winbindd_fd_event *match;
553
554         /* only add unique winbindd_fd_event structs */
555
556         for (match=fd_events; match; match=match->next ) {
557 #ifdef DEVELOPER
558                 SMB_ASSERT( match != ev );
559 #else
560                 if ( match == ev )
561                         return;
562 #endif
563         }
564
565         DLIST_ADD(fd_events, ev);
566 }
567
568 void remove_fd_event(struct winbindd_fd_event *ev)
569 {
570         DLIST_REMOVE(fd_events, ev);
571 }
572
573 /*
574  * Handler for winbindd_fd_events to complete a read/write request, set up by
575  * setup_async_read/setup_async_write.
576  */
577
578 static void rw_callback(struct winbindd_fd_event *event, int flags)
579 {
580         size_t todo;
581         ssize_t done = 0;
582
583         todo = event->length - event->done;
584
585         if (event->flags & EVENT_FD_WRITE) {
586                 SMB_ASSERT(flags == EVENT_FD_WRITE);
587                 done = sys_write(event->fd,
588                                  &((char *)event->data)[event->done],
589                                  todo);
590
591                 if (done <= 0) {
592                         event->flags = 0;
593                         event->finished(event->private_data, False);
594                         return;
595                 }
596         }
597
598         if (event->flags & EVENT_FD_READ) {
599                 SMB_ASSERT(flags == EVENT_FD_READ);
600                 done = sys_read(event->fd, &((char *)event->data)[event->done],
601                                 todo);
602
603                 if (done <= 0) {
604                         event->flags = 0;
605                         event->finished(event->private_data, False);
606                         return;
607                 }
608         }
609
610         event->done += done;
611
612         if (event->done == event->length) {
613                 event->flags = 0;
614                 event->finished(event->private_data, True);
615         }
616 }
617
618 /*
619  * Request an async read/write on a winbindd_fd_event structure. (*finished) is called
620  * when the request is completed or an error had occurred.
621  */
622
623 void setup_async_read(struct winbindd_fd_event *event, void *data, size_t length,
624                       void (*finished)(void *private_data, bool success),
625                       void *private_data)
626 {
627         SMB_ASSERT(event->flags == 0);
628         event->data = data;
629         event->length = length;
630         event->done = 0;
631         event->handler = rw_callback;
632         event->finished = finished;
633         event->private_data = private_data;
634         event->flags = EVENT_FD_READ;
635 }
636
637 void setup_async_write(struct winbindd_fd_event *event, void *data, size_t length,
638                        void (*finished)(void *private_data, bool success),
639                        void *private_data)
640 {
641         SMB_ASSERT(event->flags == 0);
642         event->data = data;
643         event->length = length;
644         event->done = 0;
645         event->handler = rw_callback;
646         event->finished = finished;
647         event->private_data = private_data;
648         event->flags = EVENT_FD_WRITE;
649 }
650
651 /*
652  * This is the main event loop of winbind requests. It goes through a
653  * state-machine of 3 read/write requests, 4 if you have extra data to send.
654  *
655  * An idle winbind client has a read request of 4 bytes outstanding,
656  * finalizing function is request_len_recv, checking the length. request_recv
657  * then processes the packet. The processing function then at some point has
658  * to call request_finished which schedules sending the response.
659  */
660
661 static void request_len_recv(void *private_data, bool success);
662 static void request_recv(void *private_data, bool success);
663 static void request_main_recv(void *private_data, bool success);
664 static void request_finished(struct winbindd_cli_state *state);
665 static void response_main_sent(void *private_data, bool success);
666 static void response_extra_sent(void *private_data, bool success);
667
668 static void response_extra_sent(void *private_data, bool success)
669 {
670         struct winbindd_cli_state *state =
671                 talloc_get_type_abort(private_data, struct winbindd_cli_state);
672
673         TALLOC_FREE(state->mem_ctx);
674
675         if (!success) {
676                 state->finished = True;
677                 return;
678         }
679
680         SAFE_FREE(state->response.extra_data.data);
681
682         setup_async_read(&state->fd_event, &state->request, sizeof(uint32),
683                          request_len_recv, state);
684 }
685
686 static void response_main_sent(void *private_data, bool success)
687 {
688         struct winbindd_cli_state *state =
689                 talloc_get_type_abort(private_data, struct winbindd_cli_state);
690
691         if (!success) {
692                 state->finished = True;
693                 return;
694         }
695
696         if (state->response.length == sizeof(state->response)) {
697                 TALLOC_FREE(state->mem_ctx);
698
699                 setup_async_read(&state->fd_event, &state->request,
700                                  sizeof(uint32), request_len_recv, state);
701                 return;
702         }
703
704         setup_async_write(&state->fd_event, state->response.extra_data.data,
705                           state->response.length - sizeof(state->response),
706                           response_extra_sent, state);
707 }
708
709 static void request_finished(struct winbindd_cli_state *state)
710 {
711         /* Make sure request.extra_data is freed when finish processing a request */
712         SAFE_FREE(state->request.extra_data.data);
713         setup_async_write(&state->fd_event, &state->response,
714                           sizeof(state->response), response_main_sent, state);
715 }
716
717 void request_error(struct winbindd_cli_state *state)
718 {
719         SMB_ASSERT(state->response.result == WINBINDD_PENDING);
720         state->response.result = WINBINDD_ERROR;
721         request_finished(state);
722 }
723
724 void request_ok(struct winbindd_cli_state *state)
725 {
726         SMB_ASSERT(state->response.result == WINBINDD_PENDING);
727         state->response.result = WINBINDD_OK;
728         request_finished(state);
729 }
730
731 static void request_len_recv(void *private_data, bool success)
732 {
733         struct winbindd_cli_state *state =
734                 talloc_get_type_abort(private_data, struct winbindd_cli_state);
735
736         if (!success) {
737                 state->finished = True;
738                 return;
739         }
740
741         if (*(uint32 *)(&state->request) != sizeof(state->request)) {
742                 DEBUG(0,("request_len_recv: Invalid request size received: %d (expected %u)\n",
743                          *(uint32_t *)(&state->request), (uint32_t)sizeof(state->request)));
744                 state->finished = True;
745                 return;
746         }
747
748         setup_async_read(&state->fd_event, (uint32 *)(&state->request)+1,
749                          sizeof(state->request) - sizeof(uint32),
750                          request_main_recv, state);
751 }
752
753 static void request_main_recv(void *private_data, bool success)
754 {
755         struct winbindd_cli_state *state =
756                 talloc_get_type_abort(private_data, struct winbindd_cli_state);
757
758         if (!success) {
759                 state->finished = True;
760                 return;
761         }
762
763         if (state->request.extra_len == 0) {
764                 state->request.extra_data.data = NULL;
765                 request_recv(state, True);
766                 return;
767         }
768
769         if ((!state->privileged) &&
770             (state->request.extra_len > WINBINDD_MAX_EXTRA_DATA)) {
771                 DEBUG(3, ("Got request with %d bytes extra data on "
772                           "unprivileged socket\n", (int)state->request.extra_len));
773                 state->request.extra_data.data = NULL;
774                 state->finished = True;
775                 return;
776         }
777
778         state->request.extra_data.data =
779                 SMB_MALLOC_ARRAY(char, state->request.extra_len + 1);
780
781         if (state->request.extra_data.data == NULL) {
782                 DEBUG(0, ("malloc failed\n"));
783                 state->finished = True;
784                 return;
785         }
786
787         /* Ensure null termination */
788         state->request.extra_data.data[state->request.extra_len] = '\0';
789
790         setup_async_read(&state->fd_event, state->request.extra_data.data,
791                          state->request.extra_len, request_recv, state);
792 }
793
794 static void request_recv(void *private_data, bool success)
795 {
796         struct winbindd_cli_state *state =
797                 talloc_get_type_abort(private_data, struct winbindd_cli_state);
798
799         if (!success) {
800                 state->finished = True;
801                 return;
802         }
803
804         process_request(state);
805 }
806
807 /* Process a new connection by adding it to the client connection list */
808
809 static void new_connection(int listen_sock, bool privileged)
810 {
811         struct sockaddr_un sunaddr;
812         struct winbindd_cli_state *state;
813         socklen_t len;
814         int sock;
815
816         /* Accept connection */
817
818         len = sizeof(sunaddr);
819
820         do {
821                 sock = accept(listen_sock, (struct sockaddr *)&sunaddr, &len);
822         } while (sock == -1 && errno == EINTR);
823
824         if (sock == -1)
825                 return;
826
827         DEBUG(6,("accepted socket %d\n", sock));
828
829         /* Create new connection structure */
830
831         if ((state = TALLOC_ZERO_P(NULL, struct winbindd_cli_state)) == NULL) {
832                 close(sock);
833                 return;
834         }
835
836         state->sock = sock;
837
838         state->last_access = time(NULL);        
839
840         state->privileged = privileged;
841
842         state->fd_event.fd = state->sock;
843         state->fd_event.flags = 0;
844         add_fd_event(&state->fd_event);
845
846         setup_async_read(&state->fd_event, &state->request, sizeof(uint32),
847                          request_len_recv, state);
848
849         /* Add to connection list */
850
851         winbindd_add_client(state);
852 }
853
854 /* Remove a client connection from client connection list */
855
856 static void remove_client(struct winbindd_cli_state *state)
857 {
858         char c = 0;
859         int nwritten;
860
861         /* It's a dead client - hold a funeral */
862
863         if (state == NULL) {
864                 return;
865         }
866
867         if (!state->finished) {
868                 /* tell client, we are closing ... */
869                 nwritten = write(state->sock, &c, sizeof(c));
870                 if (nwritten == -1) {
871                         DEBUG(2, ("final write to client failed: %s\n",
872                                   strerror(errno)));
873                 }
874         }
875
876         /* Close socket */
877
878         close(state->sock);
879
880         /* Free any getent state */
881
882         free_getent_state(state->getpwent_state);
883         free_getent_state(state->getgrent_state);
884
885         /* We may have some extra data that was not freed if the client was
886            killed unexpectedly */
887
888         SAFE_FREE(state->response.extra_data.data);
889
890         TALLOC_FREE(state->mem_ctx);
891
892         remove_fd_event(&state->fd_event);
893
894         /* Remove from list and free */
895
896         winbindd_remove_client(state);
897         TALLOC_FREE(state);
898 }
899
900 /* Shutdown client connection which has been idle for the longest time */
901
902 static bool remove_idle_client(void)
903 {
904         struct winbindd_cli_state *state, *remove_state = NULL;
905         time_t last_access = 0;
906         int nidle = 0;
907
908         for (state = winbindd_client_list(); state; state = state->next) {
909                 if (state->response.result != WINBINDD_PENDING &&
910                     state->fd_event.flags == EVENT_FD_READ &&
911                     !state->getpwent_state && !state->getgrent_state) {
912                         nidle++;
913                         if (!last_access || state->last_access < last_access) {
914                                 last_access = state->last_access;
915                                 remove_state = state;
916                         }
917                 }
918         }
919
920         if (remove_state) {
921                 DEBUG(5,("Found %d idle client connections, shutting down sock %d, pid %u\n",
922                         nidle, remove_state->sock, (unsigned int)remove_state->pid));
923                 remove_client(remove_state);
924                 return True;
925         }
926
927         return False;
928 }
929
930 struct winbindd_listen_state {
931         bool privileged;
932         int fd;
933         struct tevent_fd *fde;
934 };
935
936 static void winbindd_listen_fde_handler(struct tevent_context *ev,
937                                         struct tevent_fd *fde,
938                                         uint16_t flags,
939                                         void *private_data)
940 {
941         struct winbindd_listen_state *s = talloc_get_type_abort(private_data,
942                                           struct winbindd_listen_state);
943
944         while (winbindd_num_clients() >
945                WINBINDD_MAX_SIMULTANEOUS_CLIENTS - 1) {
946                 DEBUG(5,("winbindd: Exceeding %d client "
947                          "connections, removing idle "
948                          "connection.\n",
949                          WINBINDD_MAX_SIMULTANEOUS_CLIENTS));
950                 if (!remove_idle_client()) {
951                         DEBUG(0,("winbindd: Exceeding %d "
952                                  "client connections, no idle "
953                                  "connection found\n",
954                                  WINBINDD_MAX_SIMULTANEOUS_CLIENTS));
955                         break;
956                 }
957         }
958
959         /* new, non-privileged connection */
960         new_connection(s->fd, s->privileged);
961 }
962
963 static bool winbindd_setup_listeners(void)
964 {
965         struct winbindd_listen_state *pub_state = NULL;
966         struct winbindd_listen_state *priv_state = NULL;
967
968         pub_state = talloc(winbind_event_context(),
969                            struct winbindd_listen_state);
970         if (!pub_state) {
971                 goto failed;
972         }
973
974         pub_state->privileged = false;
975         pub_state->fd = open_winbindd_socket();
976         if (pub_state->fd == -1) {
977                 goto failed;
978         }
979
980         pub_state->fde = tevent_add_fd(winbind_event_context(),
981                                        pub_state, pub_state->fd,
982                                        TEVENT_FD_READ,
983                                        winbindd_listen_fde_handler,
984                                        pub_state);
985         if (!pub_state->fde) {
986                 close(pub_state->fd);
987                 goto failed;
988         }
989         tevent_fd_set_auto_close(pub_state->fde);
990
991         priv_state = talloc(winbind_event_context(),
992                             struct winbindd_listen_state);
993         if (!priv_state) {
994                 goto failed;
995         }
996
997         priv_state->privileged = true;
998         priv_state->fd = open_winbindd_priv_socket();
999         if (priv_state->fd == -1) {
1000                 goto failed;
1001         }
1002
1003         priv_state->fde = tevent_add_fd(winbind_event_context(),
1004                                         priv_state, priv_state->fd,
1005                                         TEVENT_FD_READ,
1006                                         winbindd_listen_fde_handler,
1007                                         priv_state);
1008         if (!priv_state->fde) {
1009                 close(priv_state->fd);
1010                 goto failed;
1011         }
1012         tevent_fd_set_auto_close(priv_state->fde);
1013
1014         return true;
1015 failed:
1016         TALLOC_FREE(pub_state);
1017         TALLOC_FREE(priv_state);
1018         return false;
1019 }
1020
1021 /* Process incoming clients on listen_sock.  We use a tricky non-blocking,
1022    non-forking, non-threaded model which allows us to handle many
1023    simultaneous connections while remaining impervious to many denial of
1024    service attacks. */
1025
1026 static void process_loop(void)
1027 {
1028         struct winbindd_fd_event *ev;
1029         fd_set r_fds, w_fds;
1030         int maxfd = 0, selret;
1031         struct timeval timeout, ev_timeout;
1032
1033         if (run_events(winbind_event_context(), 0, NULL, NULL)) {
1034                 return;
1035         }
1036
1037         /* Initialise fd lists for select() */
1038
1039         FD_ZERO(&r_fds);
1040         FD_ZERO(&w_fds);
1041
1042         timeout.tv_sec = WINBINDD_ESTABLISH_LOOP;
1043         timeout.tv_usec = 0;
1044
1045         /* Check for any event timeouts. */
1046         {
1047                 struct timeval now;
1048                 GetTimeOfDay(&now);
1049
1050                 /*
1051                  * Initialize this high as event_add_to_select_args()
1052                  * uses a timeval_min() on this and next_event. Fix
1053                  * from Roel van Meer <rolek@alt001.com>.
1054                  */
1055
1056                 ev_timeout.tv_sec = 999999;
1057                 ev_timeout.tv_usec = 0;
1058
1059                 event_add_to_select_args(winbind_event_context(), &now,
1060                                          &r_fds, &w_fds, &ev_timeout, &maxfd);
1061         }
1062         if (get_timed_events_timeout(winbind_event_context(), &ev_timeout)) {
1063                 timeout = timeval_min(&timeout, &ev_timeout);
1064         }
1065
1066         for (ev = fd_events; ev; ev = ev->next) {
1067                 if (ev->fd < 0 || ev->fd >= FD_SETSIZE) {
1068                         /* Ignore here - event_add_to_select_args
1069                            should make this impossible. */
1070                         continue;
1071                 }
1072
1073                 if (ev->flags & EVENT_FD_READ) {
1074                         FD_SET(ev->fd, &r_fds);
1075                         maxfd = MAX(ev->fd, maxfd);
1076                 }
1077                 if (ev->flags & EVENT_FD_WRITE) {
1078                         FD_SET(ev->fd, &w_fds);
1079                         maxfd = MAX(ev->fd, maxfd);
1080                 }
1081         }
1082
1083         /* Call select */
1084
1085         selret = sys_select(maxfd + 1, &r_fds, &w_fds, NULL, &timeout);
1086
1087         if (selret == 0) {
1088                 goto no_fds_ready;
1089         }
1090
1091         if (selret == -1) {
1092                 if (errno == EINTR) {
1093                         goto no_fds_ready;
1094                 }
1095
1096                 /* Select error, something is badly wrong */
1097
1098                 perror("select");
1099                 exit(1);
1100         }
1101
1102         /* selret > 0 */
1103
1104         if (run_events(winbind_event_context(), selret, &r_fds, &w_fds)) {
1105                 return;
1106         }
1107
1108         ev = fd_events;
1109         while (ev != NULL) {
1110                 struct winbindd_fd_event *next = ev->next;
1111                 int flags = 0;
1112                 if (FD_ISSET(ev->fd, &r_fds))
1113                         flags |= EVENT_FD_READ;
1114                 if (FD_ISSET(ev->fd, &w_fds))
1115                         flags |= EVENT_FD_WRITE;
1116                 if (flags) {
1117                         ev->handler(ev, flags);
1118                         return;
1119                 }
1120                 ev = next;
1121         }
1122
1123         return;
1124
1125  no_fds_ready:
1126
1127         run_events(winbind_event_context(), selret, &r_fds, &w_fds);
1128
1129 #if 0
1130         winbindd_check_cache_size(time(NULL));
1131 #endif
1132 }
1133
1134 bool winbindd_use_idmap_cache(void)
1135 {
1136         return !opt_nocache;
1137 }
1138
1139 bool winbindd_use_cache(void)
1140 {
1141         return !opt_nocache;
1142 }
1143
1144 /* Main function */
1145
1146 int main(int argc, char **argv, char **envp)
1147 {
1148         static bool is_daemon = False;
1149         static bool Fork = True;
1150         static bool log_stdout = False;
1151         static bool no_process_group = False;
1152         enum {
1153                 OPT_DAEMON = 1000,
1154                 OPT_FORK,
1155                 OPT_NO_PROCESS_GROUP,
1156                 OPT_LOG_STDOUT
1157         };
1158         struct poptOption long_options[] = {
1159                 POPT_AUTOHELP
1160                 { "stdout", 'S', POPT_ARG_NONE, NULL, OPT_LOG_STDOUT, "Log to stdout" },
1161                 { "foreground", 'F', POPT_ARG_NONE, NULL, OPT_FORK, "Daemon in foreground mode" },
1162                 { "no-process-group", 0, POPT_ARG_NONE, NULL, OPT_NO_PROCESS_GROUP, "Don't create a new process group" },
1163                 { "daemon", 'D', POPT_ARG_NONE, NULL, OPT_DAEMON, "Become a daemon (default)" },
1164                 { "interactive", 'i', POPT_ARG_NONE, NULL, 'i', "Interactive mode" },
1165                 { "no-caching", 'n', POPT_ARG_NONE, NULL, 'n', "Disable caching" },
1166                 POPT_COMMON_SAMBA
1167                 POPT_TABLEEND
1168         };
1169         poptContext pc;
1170         int opt;
1171         TALLOC_CTX *frame = talloc_stackframe();
1172
1173         /* glibc (?) likes to print "User defined signal 1" and exit if a
1174            SIGUSR[12] is received before a handler is installed */
1175
1176         CatchSignal(SIGUSR1, SIG_IGN);
1177         CatchSignal(SIGUSR2, SIG_IGN);
1178
1179         fault_setup((void (*)(void *))fault_quit );
1180         dump_core_setup("winbindd");
1181
1182         load_case_tables();
1183
1184         /* Initialise for running in non-root mode */
1185
1186         sec_init();
1187
1188         set_remote_machine_name("winbindd", False);
1189
1190         /* Set environment variable so we don't recursively call ourselves.
1191            This may also be useful interactively. */
1192
1193         if ( !winbind_off() ) {
1194                 DEBUG(0,("Failed to disable recusive winbindd calls.  Exiting.\n"));
1195                 exit(1);
1196         }
1197
1198         /* Initialise samba/rpc client stuff */
1199
1200         pc = poptGetContext("winbindd", argc, (const char **)argv, long_options, 0);
1201
1202         while ((opt = poptGetNextOpt(pc)) != -1) {
1203                 switch (opt) {
1204                         /* Don't become a daemon */
1205                 case OPT_DAEMON:
1206                         is_daemon = True;
1207                         break;
1208                 case 'i':
1209                         interactive = True;
1210                         log_stdout = True;
1211                         Fork = False;
1212                         break;
1213                 case OPT_FORK:
1214                         Fork = false;
1215                         break;
1216                 case OPT_NO_PROCESS_GROUP:
1217                         no_process_group = true;
1218                         break;
1219                 case OPT_LOG_STDOUT:
1220                         log_stdout = true;
1221                         break;
1222                 case 'n':
1223                         opt_nocache = true;
1224                         break;
1225                 default:
1226                         d_fprintf(stderr, "\nInvalid option %s: %s\n\n",
1227                                   poptBadOption(pc, 0), poptStrerror(opt));
1228                         poptPrintUsage(pc, stderr, 0);
1229                         exit(1);
1230                 }
1231         }
1232
1233         if (is_daemon && interactive) {
1234                 d_fprintf(stderr,"\nERROR: "
1235                           "Option -i|--interactive is not allowed together with -D|--daemon\n\n");
1236                 poptPrintUsage(pc, stderr, 0);
1237                 exit(1);
1238         }
1239
1240         if (log_stdout && Fork) {
1241                 d_fprintf(stderr, "\nERROR: "
1242                           "Can't log to stdout (-S) unless daemon is in foreground +(-F) or interactive (-i)\n\n");
1243                 poptPrintUsage(pc, stderr, 0);
1244                 exit(1);
1245         }
1246
1247         poptFreeContext(pc);
1248
1249         if (!override_logfile) {
1250                 char *lfile = NULL;
1251                 if (asprintf(&lfile,"%s/log.winbindd",
1252                                 get_dyn_LOGFILEBASE()) > 0) {
1253                         lp_set_logfile(lfile);
1254                         SAFE_FREE(lfile);
1255                 }
1256         }
1257         setup_logging("winbindd", log_stdout);
1258         reopen_logs();
1259
1260         DEBUG(0,("winbindd version %s started.\n", samba_version_string()));
1261         DEBUGADD(0,("%s\n", COPYRIGHT_STARTUP_MESSAGE));
1262
1263         if (!lp_load_initial_only(get_dyn_CONFIGFILE())) {
1264                 DEBUG(0, ("error opening config file\n"));
1265                 exit(1);
1266         }
1267
1268         /* Initialise messaging system */
1269
1270         if (winbind_messaging_context() == NULL) {
1271                 exit(1);
1272         }
1273
1274         if (!reload_services_file(NULL)) {
1275                 DEBUG(0, ("error opening config file\n"));
1276                 exit(1);
1277         }
1278
1279         if (!directory_exist(lp_lockdir())) {
1280                 mkdir(lp_lockdir(), 0755);
1281         }
1282
1283         /* Setup names. */
1284
1285         if (!init_names())
1286                 exit(1);
1287
1288         load_interfaces();
1289
1290         if (!secrets_init()) {
1291
1292                 DEBUG(0,("Could not initialize domain trust account secrets. Giving up\n"));
1293                 return False;
1294         }
1295
1296         /* Enable netbios namecache */
1297
1298         namecache_enable();
1299
1300         /* Unblock all signals we are interested in as they may have been
1301            blocked by the parent process. */
1302
1303         BlockSignals(False, SIGINT);
1304         BlockSignals(False, SIGQUIT);
1305         BlockSignals(False, SIGTERM);
1306         BlockSignals(False, SIGUSR1);
1307         BlockSignals(False, SIGUSR2);
1308         BlockSignals(False, SIGHUP);
1309         BlockSignals(False, SIGCHLD);
1310
1311         if (!interactive)
1312                 become_daemon(Fork, no_process_group);
1313
1314         pidfile_create("winbindd");
1315
1316 #if HAVE_SETPGID
1317         /*
1318          * If we're interactive we want to set our own process group for
1319          * signal management.
1320          */
1321         if (interactive && !no_process_group)
1322                 setpgid( (pid_t)0, (pid_t)0);
1323 #endif
1324
1325         TimeInit();
1326
1327         /* Don't use winbindd_reinit_after_fork here as
1328          * we're just starting up and haven't created any
1329          * winbindd-specific resources we must free yet. JRA.
1330          */
1331
1332         if (!NT_STATUS_IS_OK(reinit_after_fork(winbind_messaging_context(),
1333                                                winbind_event_context(),
1334                                                false))) {
1335                 DEBUG(0,("reinit_after_fork() failed\n"));
1336                 exit(1);
1337         }
1338
1339         /* Setup signal handlers */
1340
1341         if (!winbindd_setup_sig_term_handler(true))
1342                 exit(1);
1343         if (!winbindd_setup_sig_hup_handler(NULL))
1344                 exit(1);
1345         if (!winbindd_setup_sig_chld_handler())
1346                 exit(1);
1347         if (!winbindd_setup_sig_usr2_handler())
1348                 exit(1);
1349
1350         CatchSignal(SIGPIPE, SIG_IGN);                 /* Ignore sigpipe */
1351
1352         /*
1353          * Ensure all cache and idmap caches are consistent
1354          * and initialized before we startup.
1355          */
1356         if (!winbindd_cache_validate_and_initialize()) {
1357                 exit(1);
1358         }
1359
1360         /* get broadcast messages */
1361         claim_connection(NULL,"",FLAG_MSG_GENERAL|FLAG_MSG_DBWRAP);
1362
1363         /* React on 'smbcontrol winbindd reload-config' in the same way
1364            as to SIGHUP signal */
1365         messaging_register(winbind_messaging_context(), NULL,
1366                            MSG_SMB_CONF_UPDATED, msg_reload_services);
1367         messaging_register(winbind_messaging_context(), NULL,
1368                            MSG_SHUTDOWN, msg_shutdown);
1369
1370         /* Handle online/offline messages. */
1371         messaging_register(winbind_messaging_context(), NULL,
1372                            MSG_WINBIND_OFFLINE, winbind_msg_offline);
1373         messaging_register(winbind_messaging_context(), NULL,
1374                            MSG_WINBIND_ONLINE, winbind_msg_online);
1375         messaging_register(winbind_messaging_context(), NULL,
1376                            MSG_WINBIND_ONLINESTATUS, winbind_msg_onlinestatus);
1377
1378         messaging_register(winbind_messaging_context(), NULL,
1379                            MSG_DUMP_EVENT_LIST, winbind_msg_dump_event_list);
1380
1381         messaging_register(winbind_messaging_context(), NULL,
1382                            MSG_WINBIND_VALIDATE_CACHE,
1383                            winbind_msg_validate_cache);
1384
1385         messaging_register(winbind_messaging_context(), NULL,
1386                            MSG_WINBIND_DUMP_DOMAIN_LIST,
1387                            winbind_msg_dump_domain_list);
1388
1389         /* Register handler for MSG_DEBUG. */
1390         messaging_register(winbind_messaging_context(), NULL,
1391                            MSG_DEBUG,
1392                            winbind_msg_debug);
1393
1394         netsamlogon_cache_init(); /* Non-critical */
1395
1396         /* clear the cached list of trusted domains */
1397
1398         wcache_tdc_clear();     
1399
1400         if (!init_domain_list()) {
1401                 DEBUG(0,("unable to initialize domain list\n"));
1402                 exit(1);
1403         }
1404
1405         init_idmap_child();
1406         init_locator_child();
1407
1408         smb_nscd_flush_user_cache();
1409         smb_nscd_flush_group_cache();
1410
1411         /* setup listen sockets */
1412
1413         if (!winbindd_setup_listeners()) {
1414                 DEBUG(0,("winbindd_setup_listeners() failed\n"));
1415                 exit(1);
1416         }
1417
1418         TALLOC_FREE(frame);
1419         /* Loop waiting for requests */
1420         while (1) {
1421                 struct winbindd_cli_state *state;
1422
1423                 frame = talloc_stackframe();
1424
1425                 /* refresh the trusted domain cache */
1426
1427                 rescan_trusted_domains();
1428
1429                 /* Dispose of client connection if it is marked as
1430                    finished */
1431                 state = winbindd_client_list();
1432                 while (state) {
1433                         struct winbindd_cli_state *next = state->next;
1434
1435                         if (state->finished) {
1436                                 remove_client(state);
1437                         }
1438
1439                         state = next;
1440                 }
1441
1442                 process_loop();
1443
1444                 TALLOC_FREE(frame);
1445         }
1446
1447         return 0;
1448 }