lib: Remove sys_waitpid
[metze/samba/wip.git] / source3 / printing / queue_process.c
1 /*
2    Unix SMB/Netbios implementation.
3    Version 3.0
4    printing backend routines
5    Copyright (C) Andrew Tridgell 1992-2000
6    Copyright (C) Jeremy Allison 2002
7    Copyright (C) Simo Sorce 2011
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 3 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, see <http://www.gnu.org/licenses/>.
21 */
22
23 #include "includes.h"
24 #include "smbd/globals.h"
25 #include "include/messages.h"
26 #include "lib/util/util_process.h"
27 #include "printing.h"
28 #include "printing/pcap.h"
29 #include "printing/queue_process.h"
30 #include "serverid.h"
31 #include "locking/proto.h"
32 #include "smbd/smbd.h"
33 #include "rpc_server/rpc_config.h"
34 #include "printing/load.h"
35 #include "rpc_server/spoolss/srv_spoolss_nt.h"
36 #include "auth.h"
37 #include "nt_printing.h"
38
39 extern pid_t start_spoolssd(struct tevent_context *ev_ctx,
40                             struct messaging_context *msg_ctx);
41
42 /**
43  * @brief Purge stale printers and reload from pre-populated pcap cache.
44  *
45  * This function should normally only be called as a callback on a successful
46  * pcap_cache_reload().
47  *
48  * This function can cause DELETION of printers and drivers from our registry,
49  * so calling it on a failed pcap reload may REMOVE permanently all printers
50  * and drivers.
51  *
52  * @param[in] ev        The event context.
53  *
54  * @param[in] msg_ctx   The messaging context.
55  */
56 static void delete_and_reload_printers_full(struct tevent_context *ev,
57                                             struct messaging_context *msg_ctx)
58 {
59         struct auth_session_info *session_info = NULL;
60         struct spoolss_PrinterInfo2 *pinfo2 = NULL;
61         int n_services;
62         int pnum;
63         int snum;
64         const char *pname;
65         const char *sname;
66         NTSTATUS status;
67
68         n_services = lp_numservices();
69         pnum = lp_servicenumber(PRINTERS_NAME);
70
71         status = make_session_info_system(talloc_tos(), &session_info);
72         if (!NT_STATUS_IS_OK(status)) {
73                 DEBUG(3, ("reload_printers: "
74                           "Could not create system session_info\n"));
75                 /* can't remove stale printers before we
76                  * are fully initilized */
77                 return;
78         }
79
80         /*
81          * Add default config for printers added to smb.conf file and remove
82          * stale printers
83          */
84         for (snum = 0; snum < n_services; snum++) {
85                 /* avoid removing PRINTERS_NAME */
86                 if (snum == pnum) {
87                         continue;
88                 }
89
90                 /* skip no-printer services */
91                 if (!snum_is_shared_printer(snum)) {
92                         continue;
93                 }
94
95                 sname = lp_const_servicename(snum);
96                 pname = lp_printername(session_info, snum);
97
98                 /* check printer, but avoid removing non-autoloaded printers */
99                 if (lp_autoloaded(snum) && !pcap_printername_ok(pname)) {
100                         DEBUG(3, ("removing stale printer %s\n", pname));
101
102                         if (is_printer_published(session_info, session_info,
103                                                  msg_ctx,
104                                                  NULL,
105                                                  lp_servicename(session_info,
106                                                                 snum),
107                                                  &pinfo2)) {
108                                 nt_printer_publish(session_info,
109                                                    session_info,
110                                                    msg_ctx,
111                                                    pinfo2,
112                                                    DSPRINT_UNPUBLISH);
113                                 TALLOC_FREE(pinfo2);
114                         }
115                         nt_printer_remove(session_info, session_info, msg_ctx,
116                                           pname);
117                 } else {
118                         DEBUG(8, ("Adding default registry entry for printer "
119                                   "[%s], if it doesn't exist.\n", sname));
120                         nt_printer_add(session_info, session_info, msg_ctx,
121                                        sname);
122                 }
123         }
124
125         /* finally, purge old snums */
126         delete_and_reload_printers(ev, msg_ctx);
127
128         TALLOC_FREE(session_info);
129 }
130
131
132 /****************************************************************************
133  Notify smbds of new printcap data
134 **************************************************************************/
135 static void reload_pcap_change_notify(struct tevent_context *ev,
136                                struct messaging_context *msg_ctx)
137 {
138         /*
139          * Reload the printers first in the background process so that
140          * newly added printers get default values created in the registry.
141          *
142          * This will block the process for some time (~1 sec per printer), but
143          * it doesn't block smbd's servering clients.
144          */
145         delete_and_reload_printers_full(ev, msg_ctx);
146
147         message_send_all(msg_ctx, MSG_PRINTER_PCAP, NULL, 0, NULL);
148 }
149
150 struct printing_queue_housekeeping_state {
151         struct tevent_context *ev;
152         struct messaging_context *msg;
153 };
154
155 static bool print_queue_housekeeping(const struct timeval *now, void *pvt)
156 {
157         struct printing_queue_housekeeping_state *state =
158                 talloc_get_type_abort(pvt,
159                 struct printing_queue_housekeeping_state);
160         time_t printcap_cache_time = (time_t)lp_printcap_cache_time();
161         time_t t = time_mono(NULL);
162
163         DEBUG(5, ("print queue housekeeping\n"));
164
165         /* if periodic printcap rescan is enabled,
166          * see if it's time to reload */
167         if ((printcap_cache_time != 0) &&
168             (t >= (last_printer_reload_time + printcap_cache_time))) {
169                 DEBUG( 3,( "Printcap cache time expired.\n"));
170                 pcap_cache_reload(state->ev, state->msg,
171                                   &reload_pcap_change_notify);
172                 last_printer_reload_time = t;
173         }
174
175         return true;
176 }
177
178 static bool printing_subsystem_queue_tasks(struct tevent_context *ev_ctx,
179                                            struct messaging_context *msg_ctx)
180 {
181         struct printing_queue_housekeeping_state *state;
182
183         state = talloc_zero(ev_ctx, struct printing_queue_housekeeping_state);
184         if (state == NULL) {
185                 DEBUG(0,("Could not talloc printing_queue_housekeeping_state\n"));
186                 return false;
187         }
188         state->ev = ev_ctx;
189         state->msg = msg_ctx;
190
191         if (!(event_add_idle(ev_ctx, NULL,
192                              timeval_set(SMBD_HOUSEKEEPING_INTERVAL, 0),
193                              "print_queue_housekeeping",
194                              print_queue_housekeeping,
195                              state))) {
196                 DEBUG(0,("Could not add print_queue_housekeeping event\n"));
197                 return false;
198         }
199
200         return true;
201 }
202
203 static void bq_reopen_logs(char *logfile)
204 {
205         if (logfile) {
206                 lp_set_logfile(logfile);
207         }
208         reopen_logs();
209 }
210
211 static void bq_sig_term_handler(struct tevent_context *ev,
212                                 struct tevent_signal *se,
213                                 int signum,
214                                 int count,
215                                 void *siginfo,
216                                 void *private_data)
217 {
218         exit_server_cleanly("termination signal");
219 }
220
221 static void bq_setup_sig_term_handler(void)
222 {
223         struct tevent_signal *se;
224
225         se = tevent_add_signal(server_event_context(),
226                                server_event_context(),
227                                SIGTERM, 0,
228                                bq_sig_term_handler,
229                                NULL);
230         if (!se) {
231                 exit_server("failed to setup SIGTERM handler");
232         }
233 }
234
235 static void bq_sig_hup_handler(struct tevent_context *ev,
236                                 struct tevent_signal *se,
237                                 int signum,
238                                 int count,
239                                 void *siginfo,
240                                 void *pvt)
241 {
242         struct messaging_context *msg_ctx;
243
244         msg_ctx = talloc_get_type_abort(pvt, struct messaging_context);
245         change_to_root_user();
246
247         DEBUG(1, ("Reloading pcap cache after SIGHUP\n"));
248         pcap_cache_reload(ev, msg_ctx, &reload_pcap_change_notify);
249         bq_reopen_logs(NULL);
250 }
251
252 static void bq_setup_sig_hup_handler(struct tevent_context *ev,
253                                      struct messaging_context *msg_ctx)
254 {
255         struct tevent_signal *se;
256
257         se = tevent_add_signal(ev, ev, SIGHUP, 0, bq_sig_hup_handler,
258                                msg_ctx);
259         if (!se) {
260                 exit_server("failed to setup SIGHUP handler");
261         }
262 }
263
264 static void bq_sig_chld_handler(struct tevent_context *ev_ctx,
265                                 struct tevent_signal *se,
266                                 int signum, int count,
267                                 void *siginfo, void *pvt)
268 {
269         int status;
270         pid_t pid;
271
272         pid = waitpid(-1, &status, WNOHANG);
273         if (WIFEXITED(status)) {
274                 DEBUG(6, ("Bq child process %d terminated with %d\n",
275                           (int)pid, WEXITSTATUS(status)));
276         } else {
277                 DEBUG(3, ("Bq child process %d terminated abnormally\n",
278                           (int)pid));
279         }
280 }
281
282 static void bq_setup_sig_chld_handler(struct tevent_context *ev_ctx)
283 {
284         struct tevent_signal *se;
285
286         se = tevent_add_signal(ev_ctx, ev_ctx, SIGCHLD, 0,
287                                 bq_sig_chld_handler, NULL);
288         if (!se) {
289                 exit_server("failed to setup SIGCHLD handler");
290         }
291 }
292
293 static void bq_smb_conf_updated(struct messaging_context *msg_ctx,
294                                 void *private_data,
295                                 uint32_t msg_type,
296                                 struct server_id server_id,
297                                 DATA_BLOB *data)
298 {
299         struct tevent_context *ev_ctx =
300                 talloc_get_type_abort(private_data, struct tevent_context);
301
302         DEBUG(10,("smb_conf_updated: Got message saying smb.conf was "
303                   "updated. Reloading.\n"));
304         change_to_root_user();
305         pcap_cache_reload(ev_ctx, msg_ctx, &reload_pcap_change_notify);
306 }
307
308 static void printing_pause_fd_handler(struct tevent_context *ev,
309                                       struct tevent_fd *fde,
310                                       uint16_t flags,
311                                       void *private_data)
312 {
313         /*
314          * If pause_pipe[1] is closed it means the parent smbd
315          * and children exited or aborted.
316          */
317         exit_server_cleanly(NULL);
318 }
319
320 /****************************************************************************
321 main thread of the background lpq updater
322 ****************************************************************************/
323 pid_t start_background_queue(struct tevent_context *ev,
324                              struct messaging_context *msg_ctx,
325                              char *logfile)
326 {
327         pid_t pid;
328
329         /* Use local variables for this as we don't
330          * need to save the parent side of this, just
331          * ensure it closes when the process exits.
332          */
333         int pause_pipe[2];
334
335         DEBUG(3,("start_background_queue: Starting background LPQ thread\n"));
336
337         if (pipe(pause_pipe) == -1) {
338                 DEBUG(5,("start_background_queue: cannot create pipe. %s\n", strerror(errno) ));
339                 exit(1);
340         }
341
342         /*
343          * Block signals before forking child as it will have to
344          * set its own handlers. Child will re-enable SIGHUP as
345          * soon as the handlers are set up.
346          */
347         BlockSignals(true, SIGTERM);
348         BlockSignals(true, SIGHUP);
349
350         pid = fork();
351
352         /* parent or error */
353         if (pid != 0) {
354                 /* Re-enable SIGHUP before returnig */
355                 BlockSignals(false, SIGTERM);
356                 BlockSignals(false, SIGHUP);
357                 return pid;
358         }
359
360         if (pid == -1) {
361                 DEBUG(5,("start_background_queue: background LPQ thread failed to start. %s\n", strerror(errno) ));
362                 exit(1);
363         }
364
365         if (pid == 0) {
366                 struct tevent_fd *fde;
367                 int ret;
368                 NTSTATUS status;
369
370                 /* Child. */
371                 DEBUG(5,("start_background_queue: background LPQ thread started\n"));
372
373                 close(pause_pipe[0]);
374                 pause_pipe[0] = -1;
375
376                 status = smbd_reinit_after_fork(msg_ctx, ev, true, "lpqd");
377
378                 if (!NT_STATUS_IS_OK(status)) {
379                         DEBUG(0,("reinit_after_fork() failed\n"));
380                         smb_panic("reinit_after_fork() failed");
381                 }
382
383                 bq_reopen_logs(logfile);
384                 bq_setup_sig_term_handler();
385                 bq_setup_sig_hup_handler(ev, msg_ctx);
386                 bq_setup_sig_chld_handler(ev);
387
388                 BlockSignals(false, SIGTERM);
389                 BlockSignals(false, SIGHUP);
390
391                 if (!printing_subsystem_queue_tasks(ev, msg_ctx)) {
392                         exit(1);
393                 }
394
395                 if (!serverid_register(messaging_server_id(msg_ctx),
396                                        FLAG_MSG_GENERAL |
397                                        FLAG_MSG_PRINT_GENERAL)) {
398                         exit(1);
399                 }
400
401                 if (!locking_init()) {
402                         exit(1);
403                 }
404                 messaging_register(msg_ctx, ev, MSG_SMB_CONF_UPDATED,
405                                    bq_smb_conf_updated);
406                 messaging_register(msg_ctx, NULL, MSG_PRINTER_UPDATE,
407                                    print_queue_receive);
408                 /* Remove previous forwarder message set in parent. */
409                 messaging_deregister(msg_ctx, MSG_PRINTER_DRVUPGRADE, NULL);
410
411                 messaging_register(msg_ctx, NULL, MSG_PRINTER_DRVUPGRADE,
412                                    do_drv_upgrade_printer);
413
414                 fde = tevent_add_fd(ev, ev, pause_pipe[1], TEVENT_FD_READ,
415                                     printing_pause_fd_handler,
416                                     NULL);
417                 if (!fde) {
418                         DEBUG(0,("tevent_add_fd() failed for pause_pipe\n"));
419                         smb_panic("tevent_add_fd() failed for pause_pipe");
420                 }
421
422                 pcap_cache_reload(ev, msg_ctx, &reload_pcap_change_notify);
423
424                 DEBUG(5,("start_background_queue: background LPQ thread waiting for messages\n"));
425                 ret = tevent_loop_wait(ev);
426                 /* should not be reached */
427                 DEBUG(0,("background_queue: tevent_loop_wait() exited with %d - %s\n",
428                          ret, (ret == 0) ? "out of events" : strerror(errno)));
429                 exit(1);
430         }
431
432         close(pause_pipe[1]);
433
434         return pid;
435 }
436
437 /* Run before the parent forks */
438 bool printing_subsystem_init(struct tevent_context *ev_ctx,
439                              struct messaging_context *msg_ctx,
440                              bool start_daemons,
441                              bool background_queue)
442 {
443         pid_t pid = -1;
444
445         if (!print_backend_init(msg_ctx)) {
446                 return false;
447         }
448
449         /* start spoolss daemon */
450         /* start as a separate daemon only if enabled */
451         if (start_daemons && rpc_spoolss_daemon() == RPC_DAEMON_FORK) {
452
453                 pid = start_spoolssd(ev_ctx, msg_ctx);
454
455         } else if (start_daemons && background_queue) {
456
457                 pid = start_background_queue(ev_ctx, msg_ctx, NULL);
458
459         } else {
460                 bool ret;
461
462                 ret = printing_subsystem_queue_tasks(ev_ctx, msg_ctx);
463
464                 /* Publish nt printers, this requires a working winreg pipe */
465                 pcap_cache_reload(ev_ctx, msg_ctx,
466                                   &delete_and_reload_printers_full);
467
468                 return ret;
469         }
470
471         if (pid == -1) {
472                 return false;
473         }
474         background_lpq_updater_pid = pid;
475
476         return true;
477 }
478
479 void printing_subsystem_update(struct tevent_context *ev_ctx,
480                                struct messaging_context *msg_ctx,
481                                bool force)
482 {
483         if (background_lpq_updater_pid != -1) {
484                 if (pcap_cache_loaded(NULL)) {
485                         load_printers(ev_ctx, msg_ctx);
486                 }
487                 if (force) {
488                         /* Send a sighup to the background process.
489                          * this will force it to reload printers */
490                         kill(background_lpq_updater_pid, SIGHUP);
491                 }
492                 return;
493         }
494
495         pcap_cache_reload(ev_ctx, msg_ctx,
496                           &delete_and_reload_printers_full);
497 }