r18937: Protect against segc in the idmap winbindd child process
[tprouty/samba.git] / source / nsswitch / winbindd_dual.c
1 /* 
2    Unix SMB/CIFS implementation.
3
4    Winbind child daemons
5
6    Copyright (C) Andrew Tridgell 2002
7    Copyright (C) Volker Lendecke 2004,2005
8    
9    This program is free software; you can redistribute it and/or modify
10    it under the terms of the GNU General Public License as published by
11    the Free Software Foundation; either version 2 of the License, or
12    (at your option) any later version.
13    
14    This program is distributed in the hope that it will be useful,
15    but WITHOUT ANY WARRANTY; without even the implied warranty of
16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17    GNU General Public License for more details.
18    
19    You should have received a copy of the GNU General Public License
20    along with this program; if not, write to the Free Software
21    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 */
23
24 /*
25  * We fork a child per domain to be able to act non-blocking in the main
26  * winbind daemon. A domain controller thousands of miles away being being
27  * slow replying with a 10.000 user list should not hold up netlogon calls
28  * that can be handled locally.
29  */
30
31 #include "includes.h"
32 #include "winbindd.h"
33
34 #undef DBGC_CLASS
35 #define DBGC_CLASS DBGC_WINBIND
36
37 /* Read some data from a client connection */
38
39 static void child_read_request(struct winbindd_cli_state *state)
40 {
41         ssize_t len;
42
43         /* Read data */
44
45         len = read_data(state->sock, (char *)&state->request,
46                         sizeof(state->request));
47
48         if (len != sizeof(state->request)) {
49                 DEBUG(len > 0 ? 0 : 3, ("Got invalid request length: %d\n", (int)len));
50                 state->finished = True;
51                 return;
52         }
53
54         if (state->request.extra_len == 0) {
55                 state->request.extra_data.data = NULL;
56                 return;
57         }
58
59         DEBUG(10, ("Need to read %d extra bytes\n", (int)state->request.extra_len));
60
61         state->request.extra_data.data =
62                 SMB_MALLOC_ARRAY(char, state->request.extra_len + 1);
63
64         if (state->request.extra_data.data == NULL) {
65                 DEBUG(0, ("malloc failed\n"));
66                 state->finished = True;
67                 return;
68         }
69
70         /* Ensure null termination */
71         state->request.extra_data.data[state->request.extra_len] = '\0';
72
73         len = read_data(state->sock, state->request.extra_data.data,
74                         state->request.extra_len);
75
76         if (len != state->request.extra_len) {
77                 DEBUG(0, ("Could not read extra data\n"));
78                 state->finished = True;
79                 return;
80         }
81 }
82
83 /*
84  * Machinery for async requests sent to children. You set up a
85  * winbindd_request, select a child to query, and issue a async_request
86  * call. When the request is completed, the callback function you specified is
87  * called back with the private pointer you gave to async_request.
88  */
89
90 struct winbindd_async_request {
91         struct winbindd_async_request *next, *prev;
92         TALLOC_CTX *mem_ctx;
93         struct winbindd_child *child;
94         struct winbindd_request *request;
95         struct winbindd_response *response;
96         void (*continuation)(void *private_data, BOOL success);
97         void *private_data;
98 };
99
100 static void async_main_request_sent(void *private_data, BOOL success);
101 static void async_request_sent(void *private_data, BOOL success);
102 static void async_reply_recv(void *private_data, BOOL success);
103 static void schedule_async_request(struct winbindd_child *child);
104
105 void async_request(TALLOC_CTX *mem_ctx, struct winbindd_child *child,
106                    struct winbindd_request *request,
107                    struct winbindd_response *response,
108                    void (*continuation)(void *private_data, BOOL success),
109                    void *private_data)
110 {
111         struct winbindd_async_request *state;
112
113         SMB_ASSERT(continuation != NULL);
114
115         state = TALLOC_P(mem_ctx, struct winbindd_async_request);
116
117         if (state == NULL) {
118                 DEBUG(0, ("talloc failed\n"));
119                 continuation(private_data, False);
120                 return;
121         }
122
123         state->mem_ctx = mem_ctx;
124         state->child = child;
125         state->request = request;
126         state->response = response;
127         state->continuation = continuation;
128         state->private_data = private_data;
129
130         DLIST_ADD_END(child->requests, state, struct winbindd_async_request *);
131
132         schedule_async_request(child);
133
134         return;
135 }
136
137 static void async_main_request_sent(void *private_data, BOOL success)
138 {
139         struct winbindd_async_request *state =
140                 talloc_get_type_abort(private_data, struct winbindd_async_request);
141
142         if (!success) {
143                 DEBUG(5, ("Could not send async request\n"));
144
145                 state->response->length = sizeof(struct winbindd_response);
146                 state->response->result = WINBINDD_ERROR;
147                 state->continuation(state->private_data, False);
148                 return;
149         }
150
151         if (state->request->extra_len == 0) {
152                 async_request_sent(private_data, True);
153                 return;
154         }
155
156         setup_async_write(&state->child->event, state->request->extra_data.data,
157                           state->request->extra_len,
158                           async_request_sent, state);
159 }
160
161 static void async_request_sent(void *private_data_data, BOOL success)
162 {
163         struct winbindd_async_request *state =
164                 talloc_get_type_abort(private_data_data, struct winbindd_async_request);
165
166         if (!success) {
167                 DEBUG(5, ("Could not send async request\n"));
168
169                 state->response->length = sizeof(struct winbindd_response);
170                 state->response->result = WINBINDD_ERROR;
171                 state->continuation(state->private_data, False);
172                 return;
173         }
174
175         /* Request successfully sent to the child, setup the wait for reply */
176
177         setup_async_read(&state->child->event,
178                          &state->response->result,
179                          sizeof(state->response->result),
180                          async_reply_recv, state);
181 }
182
183 static void async_reply_recv(void *private_data, BOOL success)
184 {
185         struct winbindd_async_request *state =
186                 talloc_get_type_abort(private_data, struct winbindd_async_request);
187         struct winbindd_child *child = state->child;
188
189         state->response->length = sizeof(struct winbindd_response);
190
191         if (!success) {
192                 DEBUG(5, ("Could not receive async reply\n"));
193                 state->response->result = WINBINDD_ERROR;
194                 return;
195         }
196
197         SMB_ASSERT(cache_retrieve_response(child->pid,
198                                            state->response));
199
200         cache_cleanup_response(child->pid);
201         
202         DLIST_REMOVE(child->requests, state);
203
204         schedule_async_request(child);
205
206         state->continuation(state->private_data, True);
207 }
208
209 static BOOL fork_domain_child(struct winbindd_child *child);
210
211 static void schedule_async_request(struct winbindd_child *child)
212 {
213         struct winbindd_async_request *request = child->requests;
214
215         if (request == NULL) {
216                 return;
217         }
218
219         if (child->event.flags != 0) {
220                 return;         /* Busy */
221         }
222
223         if ((child->pid == 0) && (!fork_domain_child(child))) {
224                 /* Cancel all outstanding requests */
225
226                 while (request != NULL) {
227                         /* request might be free'd in the continuation */
228                         struct winbindd_async_request *next = request->next;
229                         request->continuation(request->private_data, False);
230                         request = next;
231                 }
232                 return;
233         }
234
235         setup_async_write(&child->event, request->request,
236                           sizeof(*request->request),
237                           async_main_request_sent, request);
238
239         talloc_destroy(child->mem_ctx);
240         return;
241 }
242
243 struct domain_request_state {
244         TALLOC_CTX *mem_ctx;
245         struct winbindd_domain *domain;
246         struct winbindd_request *request;
247         struct winbindd_response *response;
248         void (*continuation)(void *private_data_data, BOOL success);
249         void *private_data_data;
250 };
251
252 static void domain_init_recv(void *private_data_data, BOOL success);
253
254 void async_domain_request(TALLOC_CTX *mem_ctx,
255                           struct winbindd_domain *domain,
256                           struct winbindd_request *request,
257                           struct winbindd_response *response,
258                           void (*continuation)(void *private_data_data, BOOL success),
259                           void *private_data_data)
260 {
261         struct domain_request_state *state;
262
263         if (domain->initialized) {
264                 async_request(mem_ctx, &domain->child, request, response,
265                               continuation, private_data_data);
266                 return;
267         }
268
269         state = TALLOC_P(mem_ctx, struct domain_request_state);
270         if (state == NULL) {
271                 DEBUG(0, ("talloc failed\n"));
272                 continuation(private_data_data, False);
273                 return;
274         }
275
276         state->mem_ctx = mem_ctx;
277         state->domain = domain;
278         state->request = request;
279         state->response = response;
280         state->continuation = continuation;
281         state->private_data_data = private_data_data;
282
283         init_child_connection(domain, domain_init_recv, state);
284 }
285
286 static void recvfrom_child(void *private_data_data, BOOL success)
287 {
288         struct winbindd_cli_state *state =
289                 talloc_get_type_abort(private_data_data, struct winbindd_cli_state);
290         enum winbindd_result result = state->response.result;
291
292         /* This is an optimization: The child has written directly to the
293          * response buffer. The request itself is still in pending state,
294          * state that in the result code. */
295
296         state->response.result = WINBINDD_PENDING;
297
298         if ((!success) || (result != WINBINDD_OK)) {
299                 request_error(state);
300                 return;
301         }
302
303         request_ok(state);
304 }
305
306 void sendto_child(struct winbindd_cli_state *state,
307                   struct winbindd_child *child)
308 {
309         async_request(state->mem_ctx, child, &state->request,
310                       &state->response, recvfrom_child, state);
311 }
312
313 void sendto_domain(struct winbindd_cli_state *state,
314                    struct winbindd_domain *domain)
315 {
316         async_domain_request(state->mem_ctx, domain,
317                              &state->request, &state->response,
318                              recvfrom_child, state);
319 }
320
321 static void domain_init_recv(void *private_data_data, BOOL success)
322 {
323         struct domain_request_state *state =
324                 talloc_get_type_abort(private_data_data, struct domain_request_state);
325
326         if (!success) {
327                 DEBUG(5, ("Domain init returned an error\n"));
328                 state->continuation(state->private_data_data, False);
329                 return;
330         }
331
332         async_request(state->mem_ctx, &state->domain->child,
333                       state->request, state->response,
334                       state->continuation, state->private_data_data);
335 }
336
337 struct winbindd_child_dispatch_table {
338         enum winbindd_cmd cmd;
339         enum winbindd_result (*fn)(struct winbindd_domain *domain,
340                                    struct winbindd_cli_state *state);
341         const char *winbindd_cmd_name;
342 };
343
344 static struct winbindd_child_dispatch_table child_dispatch_table[] = {
345         
346         { WINBINDD_LOOKUPSID,            winbindd_dual_lookupsid,             "LOOKUPSID" },
347         { WINBINDD_LOOKUPNAME,           winbindd_dual_lookupname,            "LOOKUPNAME" },
348         { WINBINDD_LOOKUPRIDS,           winbindd_dual_lookuprids,            "LOOKUPRIDS" },
349         { WINBINDD_LIST_TRUSTDOM,        winbindd_dual_list_trusted_domains,  "LIST_TRUSTDOM" },
350         { WINBINDD_INIT_CONNECTION,      winbindd_dual_init_connection,       "INIT_CONNECTION" },
351         { WINBINDD_GETDCNAME,            winbindd_dual_getdcname,             "GETDCNAME" },
352         { WINBINDD_SHOW_SEQUENCE,        winbindd_dual_show_sequence,         "SHOW_SEQUENCE" },
353         { WINBINDD_PAM_AUTH,             winbindd_dual_pam_auth,              "PAM_AUTH" },
354         { WINBINDD_PAM_AUTH_CRAP,        winbindd_dual_pam_auth_crap,         "AUTH_CRAP" },
355         { WINBINDD_PAM_LOGOFF,           winbindd_dual_pam_logoff,            "PAM_LOGOFF" },
356         { WINBINDD_PAM_CHNG_PSWD_AUTH_CRAP,winbindd_dual_pam_chng_pswd_auth_crap,"CHNG_PSWD_AUTH_CRAP" },
357         { WINBINDD_CHECK_MACHACC,        winbindd_dual_check_machine_acct,    "CHECK_MACHACC" },
358         { WINBINDD_DUAL_SID2UID,         winbindd_dual_sid2uid,               "DUAL_SID2UID" },
359         { WINBINDD_DUAL_SID2GID,         winbindd_dual_sid2gid,               "DUAL_SID2GID" },
360         { WINBINDD_DUAL_UID2SID,         winbindd_dual_uid2sid,               "DUAL_UID2SID" },
361         { WINBINDD_DUAL_GID2SID,         winbindd_dual_gid2sid,               "DUAL_GID2SID" },
362         { WINBINDD_DUAL_UID2NAME,        winbindd_dual_uid2name,              "DUAL_UID2NAME" },
363         { WINBINDD_DUAL_NAME2UID,        winbindd_dual_name2uid,              "DUAL_NAME2UID" },
364         { WINBINDD_DUAL_GID2NAME,        winbindd_dual_gid2name,              "DUAL_GID2NAME" },
365         { WINBINDD_DUAL_NAME2GID,        winbindd_dual_name2gid,              "DUAL_NAME2GID" },
366         { WINBINDD_DUAL_IDMAPSET,        winbindd_dual_idmapset,              "DUAL_IDMAPSET" },
367         { WINBINDD_DUAL_USERINFO,        winbindd_dual_userinfo,              "DUAL_USERINFO" },
368         { WINBINDD_ALLOCATE_UID,         winbindd_dual_allocate_uid,          "ALLOCATE_UID" },
369         { WINBINDD_ALLOCATE_GID,         winbindd_dual_allocate_gid,          "ALLOCATE_GID" },
370         { WINBINDD_GETUSERDOMGROUPS,     winbindd_dual_getuserdomgroups,      "GETUSERDOMGROUPS" },
371         { WINBINDD_DUAL_GETSIDALIASES,   winbindd_dual_getsidaliases,         "GETSIDALIASES" },
372         { WINBINDD_CCACHE_NTLMAUTH,      winbindd_dual_ccache_ntlm_auth,      "CCACHE_NTLM_AUTH" },
373         /* End of list */
374
375         { WINBINDD_NUM_CMDS, NULL, "NONE" }
376 };
377
378 static void child_process_request(struct winbindd_domain *domain,
379                                   struct winbindd_cli_state *state)
380 {
381         struct winbindd_child_dispatch_table *table;
382
383         /* Free response data - we may be interrupted and receive another
384            command before being able to send this data off. */
385
386         state->response.result = WINBINDD_ERROR;
387         state->response.length = sizeof(struct winbindd_response);
388
389         state->mem_ctx = talloc_init("winbind request");
390         if (state->mem_ctx == NULL)
391                 return;
392
393         /* Process command */
394
395         for (table = child_dispatch_table; table->fn; table++) {
396                 if (state->request.cmd == table->cmd) {
397                         DEBUG(10,("process_request: request fn %s\n",
398                                   table->winbindd_cmd_name ));
399                         state->response.result = table->fn(domain, state);
400                         break;
401                 }
402         }
403
404         if (!table->fn) {
405                 DEBUG(10,("process_request: unknown request fn number %d\n",
406                           (int)state->request.cmd ));
407                 state->response.result = WINBINDD_ERROR;
408         }
409
410         talloc_destroy(state->mem_ctx);
411 }
412
413 void setup_domain_child(struct winbindd_domain *domain,
414                         struct winbindd_child *child,
415                         const char *explicit_logfile)
416 {
417         if (explicit_logfile != NULL) {
418                 pstr_sprintf(child->logfilename, "%s/log.winbindd-%s",
419                              dyn_LOGFILEBASE, explicit_logfile);
420         } else if (domain != NULL) {
421                 pstr_sprintf(child->logfilename, "%s/log.wb-%s",
422                              dyn_LOGFILEBASE, domain->name);
423         } else {
424                 smb_panic("Internal error: domain == NULL && "
425                           "explicit_logfile == NULL");
426         }
427
428         child->domain = domain;
429 }
430
431 struct winbindd_child *children = NULL;
432
433 void winbind_child_died(pid_t pid)
434 {
435         struct winbindd_child *child;
436
437         for (child = children; child != NULL; child = child->next) {
438                 if (child->pid == pid) {
439                         break;
440                 }
441         }
442
443         if (child == NULL) {
444                 DEBUG(0, ("Unknown child %d died!\n", pid));
445                 return;
446         }
447
448         remove_fd_event(&child->event);
449         close(child->event.fd);
450         child->event.fd = 0;
451         child->event.flags = 0;
452         child->pid = 0;
453
454         schedule_async_request(child);
455 }
456
457 /* Forward the online/offline messages to our children. */
458 void winbind_msg_offline(int msg_type, struct process_id src, void *buf, size_t len)
459 {
460         struct winbindd_child *child;
461
462         DEBUG(10,("winbind_msg_offline: got offline message.\n"));
463
464         if (!lp_winbind_offline_logon()) {
465                 DEBUG(10,("winbind_msg_offline: rejecting offline message.\n"));
466                 return;
467         }
468
469         /* Set our global state as offline. */
470         if (!set_global_winbindd_state_offline()) {
471                 DEBUG(10,("winbind_msg_offline: offline request failed.\n"));
472                 return;
473         }
474
475         for (child = children; child != NULL; child = child->next) {
476                 DEBUG(10,("winbind_msg_offline: sending message to pid %u.\n",
477                         (unsigned int)child->pid ));
478                 message_send_pid(pid_to_procid(child->pid), MSG_WINBIND_OFFLINE, NULL, 0, False);
479         }
480 }
481
482 /* Forward the online/offline messages to our children. */
483 void winbind_msg_online(int msg_type, struct process_id src, void *buf, size_t len)
484 {
485         struct winbindd_child *child;
486
487         DEBUG(10,("winbind_msg_online: got online message.\n"));
488
489         if (!lp_winbind_offline_logon()) {
490                 DEBUG(10,("winbind_msg_online: rejecting online message.\n"));
491                 return;
492         }
493
494         /* Set our global state as online. */
495         set_global_winbindd_state_online();
496
497         for (child = children; child != NULL; child = child->next) {
498                 DEBUG(10,("winbind_msg_online: sending message to pid %u.\n",
499                         (unsigned int)child->pid ));
500                 message_send_pid(pid_to_procid(child->pid), MSG_WINBIND_ONLINE, NULL, 0, False);
501         }
502 }
503
504 /* Forward the online/offline messages to our children. */
505 void winbind_msg_onlinestatus(int msg_type, struct process_id src, void *buf, size_t len)
506 {
507         struct winbindd_child *child;
508
509         DEBUG(10,("winbind_msg_onlinestatus: got onlinestatus message.\n"));
510
511         for (child = children; child != NULL; child = child->next) {
512                 if (child->domain && child->domain->primary) {
513                         DEBUG(10,("winbind_msg_onlinestatus: "
514                                   "sending message to pid %u of primary domain.\n",
515                                   (unsigned int)child->pid));
516                         message_send_pid(pid_to_procid(child->pid), 
517                                          MSG_WINBIND_ONLINESTATUS, buf, len, False);
518                         break;
519                 }
520         }
521 }
522
523
524 static void account_lockout_policy_handler(struct timed_event *te,
525                                            const struct timeval *now,
526                                            void *private_data)
527 {
528         struct winbindd_child *child =
529                 (struct winbindd_child *)private_data;
530
531         struct winbindd_methods *methods;
532         SAM_UNK_INFO_12 lockout_policy;
533         NTSTATUS result;
534
535         DEBUG(10,("account_lockout_policy_handler called\n"));
536
537         if (child->lockout_policy_event) {
538                 TALLOC_FREE(child->lockout_policy_event);
539         }
540
541         methods = child->domain->methods;
542
543         result = methods->lockout_policy(child->domain, child->mem_ctx, &lockout_policy);
544         if (!NT_STATUS_IS_OK(result)) {
545                 DEBUG(10,("account_lockout_policy_handler: failed to call lockout_policy\n"));
546                 return;
547         }
548
549         child->lockout_policy_event = add_timed_event(child->mem_ctx, 
550                                                       timeval_current_ofs(3600, 0),
551                                                       "account_lockout_policy_handler",
552                                                       account_lockout_policy_handler,
553                                                       child);
554 }
555
556 /* Deal with a request to go offline. */
557
558 static void child_msg_offline(int msg_type, struct process_id src, void *buf, size_t len)
559 {
560         struct winbindd_domain *domain;
561
562         DEBUG(5,("child_msg_offline received.\n"));
563
564         if (!lp_winbind_offline_logon()) {
565                 DEBUG(10,("child_msg_offline: rejecting offline message.\n"));
566                 return;
567         }
568
569         /* Set our global state as offline. */
570         if (!set_global_winbindd_state_offline()) {
571                 DEBUG(10,("child_msg_offline: offline request failed.\n"));
572                 return;
573         }
574
575         /* Mark all our domains as offline. */
576
577         for (domain = domain_list(); domain; domain = domain->next) {
578                 DEBUG(5,("child_msg_offline: marking %s offline.\n", domain->name));
579                 set_domain_offline(domain);
580         }
581 }
582
583 /* Ensure any negative cache entries with the netbios or realm names are removed. */
584
585 void winbindd_flush_negative_conn_cache(struct winbindd_domain *domain)
586 {
587         flush_negative_conn_cache_for_domain(domain->name);
588         if (*domain->alt_name) {
589                 flush_negative_conn_cache_for_domain(domain->alt_name);
590         }
591 }
592
593 /* Deal with a request to go online. */
594
595 static void child_msg_online(int msg_type, struct process_id src, void *buf, size_t len)
596 {
597         struct winbindd_domain *domain;
598
599         DEBUG(5,("child_msg_online received.\n"));
600
601         if (!lp_winbind_offline_logon()) {
602                 DEBUG(10,("child_msg_online: rejecting online message.\n"));
603                 return;
604         }
605
606         /* Set our global state as online. */
607         set_global_winbindd_state_online();
608
609         smb_nscd_flush_user_cache();
610         smb_nscd_flush_group_cache();
611
612         /* Try and mark everything online - delete any negative cache entries
613            to force a reconnect now. */
614
615         for (domain = domain_list(); domain; domain = domain->next) {
616                 DEBUG(5,("child_msg_online: marking %s online.\n", domain->name));
617                 winbindd_flush_negative_conn_cache(domain);
618                 set_domain_online_request(domain);
619         }
620 }
621
622 static const char *collect_onlinestatus(TALLOC_CTX *mem_ctx)
623 {
624         struct winbindd_domain *domain;
625         char *buf = NULL;
626
627         if ((buf = talloc_asprintf(mem_ctx, "global:%s ", 
628                                    get_global_winbindd_state_offline() ? 
629                                    "Offline":"Online")) == NULL) {
630                 return NULL;
631         }
632
633         for (domain = domain_list(); domain; domain = domain->next) {
634                 if ((buf = talloc_asprintf_append(buf, "%s:%s ", 
635                                                   domain->name, 
636                                                   domain->online ?
637                                                   "Online":"Offline")) == NULL) {
638                         return NULL;
639                 }
640         }
641
642         buf = talloc_asprintf_append(buf, "\n");
643
644         DEBUG(5,("collect_onlinestatus: %s", buf));
645
646         return buf;
647 }
648
649 static void child_msg_onlinestatus(int msg_type, struct process_id src, void *buf, size_t len)
650 {
651         TALLOC_CTX *mem_ctx;
652         const char *message;
653         struct process_id *sender;
654         
655         DEBUG(5,("winbind_msg_onlinestatus received.\n"));
656
657         if (!buf) {
658                 return;
659         }
660
661         sender = (struct process_id *)buf;
662
663         mem_ctx = talloc_init("winbind_msg_onlinestatus");
664         if (mem_ctx == NULL) {
665                 return;
666         }
667         
668         message = collect_onlinestatus(mem_ctx);
669         if (message == NULL) {
670                 talloc_destroy(mem_ctx);
671                 return;
672         }
673
674         message_send_pid(*sender, MSG_WINBIND_ONLINESTATUS, 
675                          message, strlen(message) + 1, True);
676
677         talloc_destroy(mem_ctx);
678 }
679
680 static BOOL fork_domain_child(struct winbindd_child *child)
681 {
682         int fdpair[2];
683         struct winbindd_cli_state state;
684         extern BOOL override_logfile;
685         time_t startup_time;
686
687         if (socketpair(AF_UNIX, SOCK_STREAM, 0, fdpair) != 0) {
688                 DEBUG(0, ("Could not open child pipe: %s\n",
689                           strerror(errno)));
690                 return False;
691         }
692
693         ZERO_STRUCT(state);
694         state.pid = getpid();
695
696         /* Ensure we don't process messages whilst we're
697            changing the disposition for the child. */
698         message_block();
699
700         child->pid = sys_fork();
701
702         if (child->pid == -1) {
703                 DEBUG(0, ("Could not fork: %s\n", strerror(errno)));
704                 message_unblock();
705                 return False;
706         }
707
708         if (child->pid != 0) {
709                 /* Parent */
710                 close(fdpair[0]);
711                 child->next = child->prev = NULL;
712                 DLIST_ADD(children, child);
713                 child->event.fd = fdpair[1];
714                 child->event.flags = 0;
715                 child->requests = NULL;
716                 add_fd_event(&child->event);
717                 /* We're ok with online/offline messages now. */
718                 message_unblock();
719                 return True;
720         }
721
722         /* Child */
723
724         state.sock = fdpair[0];
725         close(fdpair[1]);
726
727         /* tdb needs special fork handling */
728         if (tdb_reopen_all(1) == -1) {
729                 DEBUG(0,("tdb_reopen_all failed.\n"));
730                 _exit(0);
731         }
732
733         close_conns_after_fork();
734
735         if (!override_logfile) {
736                 lp_set_logfile(child->logfilename);
737                 reopen_logs();
738         }
739
740         /* Don't handle the same messages as our parent. */
741         message_deregister(MSG_SMB_CONF_UPDATED);
742         message_deregister(MSG_SHUTDOWN);
743         message_deregister(MSG_WINBIND_OFFLINE);
744         message_deregister(MSG_WINBIND_ONLINE);
745         message_deregister(MSG_WINBIND_ONLINESTATUS);
746
747         /* The child is ok with online/offline messages now. */
748         message_unblock();
749
750         child->mem_ctx = talloc_init("child_mem_ctx");
751         if (child->mem_ctx == NULL) {
752                 return False;
753         }
754
755         if (child->domain != NULL && lp_winbind_offline_logon()) {
756                 /* We might be in the idmap child...*/
757                 child->lockout_policy_event = add_timed_event(
758                         child->mem_ctx, timeval_zero(),
759                         "account_lockout_policy_handler",
760                         account_lockout_policy_handler,
761                         child);
762         }
763
764         /* Handle online/offline messages. */
765         message_register(MSG_WINBIND_OFFLINE,child_msg_offline);
766         message_register(MSG_WINBIND_ONLINE,child_msg_online);
767         message_register(MSG_WINBIND_ONLINESTATUS,child_msg_onlinestatus);
768
769         if ( child->domain ) {
770                 child->domain->startup = True;
771         }
772         startup_time = time(NULL);
773
774         while (1) {
775
776                 int ret;
777                 fd_set read_fds;
778                 struct timeval t;
779                 struct timeval *tp;
780                 struct timeval now;
781
782                 /* free up any talloc memory */
783                 lp_TALLOC_FREE();
784                 main_loop_TALLOC_FREE();
785
786                 run_events();
787
788                 GetTimeOfDay(&now);
789
790                 if (child->domain && child->domain->startup && (now.tv_sec > startup_time + 30)) {
791                         /* No longer in "startup" mode. */
792                         DEBUG(10,("fork_domain_child: domain %s no longer in 'startup' mode.\n",
793                                 child->domain->name ));
794                         child->domain->startup = False;
795                 }
796
797                 tp = get_timed_events_timeout(&t);
798                 if (tp) {
799                         DEBUG(11,("select will use timeout of %u.%u seconds\n",
800                                 (unsigned int)tp->tv_sec, (unsigned int)tp->tv_usec ));
801                 }
802
803                 /* Handle messages */
804
805                 message_dispatch();
806
807                 FD_ZERO(&read_fds);
808                 FD_SET(state.sock, &read_fds);
809
810                 ret = sys_select(state.sock + 1, &read_fds, NULL, NULL, tp);
811
812                 if (ret == 0) {
813                         DEBUG(11,("nothing is ready yet, continue\n"));
814                         continue;
815                 }
816
817                 if (ret == -1 && errno == EINTR) {
818                         /* We got a signal - continue. */
819                         continue;
820                 }
821
822                 if (ret == -1 && errno != EINTR) {
823                         DEBUG(0,("select error occured\n"));
824                         perror("select");
825                         return False;
826                 }
827
828                 /* fetch a request from the main daemon */
829                 child_read_request(&state);
830
831                 if (state.finished) {
832                         /* we lost contact with our parent */
833                         exit(0);
834                 }
835
836                 DEBUG(4,("child daemon request %d\n", (int)state.request.cmd));
837
838                 ZERO_STRUCT(state.response);
839                 state.request.null_term = '\0';
840                 child_process_request(child->domain, &state);
841
842                 SAFE_FREE(state.request.extra_data.data);
843
844                 cache_store_response(sys_getpid(), &state.response);
845
846                 SAFE_FREE(state.response.extra_data.data);
847
848                 /* We just send the result code back, the result
849                  * structure needs to be fetched via the
850                  * winbindd_cache. Hmm. That needs fixing... */
851
852                 if (write_data(state.sock,
853                                (const char *)&state.response.result,
854                                sizeof(state.response.result)) !=
855                     sizeof(state.response.result)) {
856                         DEBUG(0, ("Could not write result\n"));
857                         exit(1);
858                 }
859         }
860 }