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
 161         DEBUG(5, ("print queue housekeeping\n"));
 162         pcap_cache_reload(state->ev, state->msg, &reload_pcap_change_notify);
 163
 164         return true;
 165 }
 166
 167 static bool printing_subsystem_queue_tasks(struct tevent_context *ev_ctx,
 168                                            struct messaging_context *msg_ctx)
 169 {
 170         struct printing_queue_housekeeping_state *state;
 171         uint32_t housekeeping_period = lp_printcap_cache_time();
 172
 173         state = talloc_zero(ev_ctx, struct printing_queue_housekeeping_state);
 174         if (state == NULL) {
 175                 DEBUG(0,("Could not talloc printing_queue_housekeeping_state\n"));
 176                 return false;
 177         }
 178         state->ev = ev_ctx;
 179         state->msg = msg_ctx;
 180
 181         if (housekeeping_period == 0) {
 182                 DEBUG(4, ("background print queue housekeeping disabled\n"));
 183                 return true;
 184         }
 185
 186         if (!(event_add_idle(ev_ctx, NULL,
 187                              timeval_set(housekeeping_period, 0),
 188                              "print_queue_housekeeping",
 189                              print_queue_housekeeping,
 190                              state))) {
 191                 DEBUG(0,("Could not add print_queue_housekeeping event\n"));
 192                 return false;
 193         }
 194
 195         return true;
 196 }
 197
 198 static void bq_reopen_logs(char *logfile)
 199 {
 200         if (logfile) {
 201                 lp_set_logfile(logfile);
 202         }
 203         reopen_logs();
 204 }
 205
 206 static void bq_sig_term_handler(struct tevent_context *ev,
 207                                 struct tevent_signal *se,
 208                                 int signum,
 209                                 int count,
 210                                 void *siginfo,
 211                                 void *private_data)
 212 {
 213         exit_server_cleanly("termination signal");
 214 }
 215
 216 static void bq_setup_sig_term_handler(void)
 217 {
 218         struct tevent_signal *se;
 219
 220         se = tevent_add_signal(server_event_context(),
 221                                server_event_context(),
 222                                SIGTERM, 0,
 223                                bq_sig_term_handler,
 224                                NULL);
 225         if (!se) {
 226                 exit_server("failed to setup SIGTERM handler");
 227         }
 228 }
 229
 230 static void bq_sig_hup_handler(struct tevent_context *ev,
 231                                 struct tevent_signal *se,
 232                                 int signum,
 233                                 int count,
 234                                 void *siginfo,
 235                                 void *pvt)
 236 {
 237         struct messaging_context *msg_ctx;
 238
 239         msg_ctx = talloc_get_type_abort(pvt, struct messaging_context);
 240         change_to_root_user();
 241
 242         DEBUG(1, ("Reloading pcap cache after SIGHUP\n"));
 243         pcap_cache_reload(ev, msg_ctx, &reload_pcap_change_notify);
 244         bq_reopen_logs(NULL);
 245 }
 246
 247 static void bq_setup_sig_hup_handler(struct tevent_context *ev,
 248                                      struct messaging_context *msg_ctx)
 249 {
 250         struct tevent_signal *se;
 251
 252         se = tevent_add_signal(ev, ev, SIGHUP, 0, bq_sig_hup_handler,
 253                                msg_ctx);
 254         if (!se) {
 255                 exit_server("failed to setup SIGHUP handler");
 256         }
 257 }
 258
 259 static void bq_sig_chld_handler(struct tevent_context *ev_ctx,
 260                                 struct tevent_signal *se,
 261                                 int signum, int count,
 262                                 void *siginfo, void *pvt)
 263 {
 264         int status;
 265         pid_t pid;
 266
 267         pid = waitpid(-1, &status, WNOHANG);
 268         if (WIFEXITED(status)) {
 269                 DEBUG(6, ("Bq child process %d terminated with %d\n",
 270                           (int)pid, WEXITSTATUS(status)));
 271         } else {
 272                 DEBUG(3, ("Bq child process %d terminated abnormally\n",
 273                           (int)pid));
 274         }
 275 }
 276
 277 static void bq_setup_sig_chld_handler(struct tevent_context *ev_ctx)
 278 {
 279         struct tevent_signal *se;
 280
 281         se = tevent_add_signal(ev_ctx, ev_ctx, SIGCHLD, 0,
 282                                 bq_sig_chld_handler, NULL);
 283         if (!se) {
 284                 exit_server("failed to setup SIGCHLD handler");
 285         }
 286 }
 287
 288 static void bq_smb_conf_updated(struct messaging_context *msg_ctx,
 289                                 void *private_data,
 290                                 uint32_t msg_type,
 291                                 struct server_id server_id,
 292                                 DATA_BLOB *data)
 293 {
 294         struct tevent_context *ev_ctx =
 295                 talloc_get_type_abort(private_data, struct tevent_context);
 296
 297         DEBUG(10,("smb_conf_updated: Got message saying smb.conf was "
 298                   "updated. Reloading.\n"));
 299         change_to_root_user();
 300         pcap_cache_reload(ev_ctx, msg_ctx, &reload_pcap_change_notify);
 301 }
 302
 303 static void printing_pause_fd_handler(struct tevent_context *ev,
 304                                       struct tevent_fd *fde,
 305                                       uint16_t flags,
 306                                       void *private_data)
 307 {
 308         /*
 309          * If pause_pipe[1] is closed it means the parent smbd
 310          * and children exited or aborted.
 311          */
 312         exit_server_cleanly(NULL);
 313 }
 314
 315 /****************************************************************************
 316 main thread of the background lpq updater
 317 ****************************************************************************/
 318 pid_t start_background_queue(struct tevent_context *ev,
 319                              struct messaging_context *msg_ctx,
 320                              char *logfile)
 321 {
 322         pid_t pid;
 323
 324         /* Use local variables for this as we don't
 325          * need to save the parent side of this, just
 326          * ensure it closes when the process exits.
 327          */
 328         int pause_pipe[2];
 329
 330         DEBUG(3,("start_background_queue: Starting background LPQ thread\n"));
 331
 332         if (pipe(pause_pipe) == -1) {
 333                 DEBUG(5,("start_background_queue: cannot create pipe. %s\n", strerror(errno) ));
 334                 exit(1);
 335         }
 336
 337         /*
 338          * Block signals before forking child as it will have to
 339          * set its own handlers. Child will re-enable SIGHUP as
 340          * soon as the handlers are set up.
 341          */
 342         BlockSignals(true, SIGTERM);
 343         BlockSignals(true, SIGHUP);
 344
 345         pid = fork();
 346
 347         /* parent or error */
 348         if (pid != 0) {
 349                 /* Re-enable SIGHUP before returnig */
 350                 BlockSignals(false, SIGTERM);
 351                 BlockSignals(false, SIGHUP);
 352                 return pid;
 353         }
 354
 355         if (pid == -1) {
 356                 DEBUG(5,("start_background_queue: background LPQ thread failed to start. %s\n", strerror(errno) ));
 357                 exit(1);
 358         }
 359
 360         if (pid == 0) {
 361                 struct tevent_fd *fde;
 362                 int ret;
 363                 NTSTATUS status;
 364
 365                 /* Child. */
 366                 DEBUG(5,("start_background_queue: background LPQ thread started\n"));
 367
 368                 close(pause_pipe[0]);
 369                 pause_pipe[0] = -1;
 370
 371                 status = smbd_reinit_after_fork(msg_ctx, ev, true, "lpqd");
 372
 373                 if (!NT_STATUS_IS_OK(status)) {
 374                         DEBUG(0,("reinit_after_fork() failed\n"));
 375                         smb_panic("reinit_after_fork() failed");
 376                 }
 377
 378                 bq_reopen_logs(logfile);
 379                 bq_setup_sig_term_handler();
 380                 bq_setup_sig_hup_handler(ev, msg_ctx);
 381                 bq_setup_sig_chld_handler(ev);
 382
 383                 BlockSignals(false, SIGTERM);
 384                 BlockSignals(false, SIGHUP);
 385
 386                 if (!printing_subsystem_queue_tasks(ev, msg_ctx)) {
 387                         exit(1);
 388                 }
 389
 390                 if (!serverid_register(messaging_server_id(msg_ctx),
 391                                        FLAG_MSG_GENERAL |
 392                                        FLAG_MSG_PRINT_GENERAL)) {
 393                         exit(1);
 394                 }
 395
 396                 if (!locking_init()) {
 397                         exit(1);
 398                 }
 399                 messaging_register(msg_ctx, ev, MSG_SMB_CONF_UPDATED,
 400                                    bq_smb_conf_updated);
 401                 messaging_register(msg_ctx, NULL, MSG_PRINTER_UPDATE,
 402                                    print_queue_receive);
 403                 /* Remove previous forwarder message set in parent. */
 404                 messaging_deregister(msg_ctx, MSG_PRINTER_DRVUPGRADE, NULL);
 405
 406                 messaging_register(msg_ctx, NULL, MSG_PRINTER_DRVUPGRADE,
 407                                    do_drv_upgrade_printer);
 408
 409                 fde = tevent_add_fd(ev, ev, pause_pipe[1], TEVENT_FD_READ,
 410                                     printing_pause_fd_handler,
 411                                     NULL);
 412                 if (!fde) {
 413                         DEBUG(0,("tevent_add_fd() failed for pause_pipe\n"));
 414                         smb_panic("tevent_add_fd() failed for pause_pipe");
 415                 }
 416
 417                 pcap_cache_reload(ev, msg_ctx, &reload_pcap_change_notify);
 418
 419                 DEBUG(5,("start_background_queue: background LPQ thread waiting for messages\n"));
 420                 ret = tevent_loop_wait(ev);
 421                 /* should not be reached */
 422                 DEBUG(0,("background_queue: tevent_loop_wait() exited with %d - %s\n",
 423                          ret, (ret == 0) ? "out of events" : strerror(errno)));
 424                 exit(1);
 425         }
 426
 427         close(pause_pipe[1]);
 428
 429         return pid;
 430 }
 431
 432 /* Run before the parent forks */
 433 bool printing_subsystem_init(struct tevent_context *ev_ctx,
 434                              struct messaging_context *msg_ctx,
 435                              bool start_daemons,
 436                              bool background_queue)
 437 {
 438         pid_t pid = -1;
 439
 440         if (!print_backend_init(msg_ctx)) {
 441                 return false;
 442         }
 443
 444         /* start spoolss daemon */
 445         /* start as a separate daemon only if enabled */
 446         if (start_daemons && rpc_spoolss_daemon() == RPC_DAEMON_FORK) {
 447
 448                 pid = start_spoolssd(ev_ctx, msg_ctx);
 449
 450         } else if (start_daemons && background_queue) {
 451
 452                 pid = start_background_queue(ev_ctx, msg_ctx, NULL);
 453
 454         } else {
 455                 bool ret;
 456
 457                 ret = printing_subsystem_queue_tasks(ev_ctx, msg_ctx);
 458
 459                 /* Publish nt printers, this requires a working winreg pipe */
 460                 pcap_cache_reload(ev_ctx, msg_ctx,
 461                                   &delete_and_reload_printers_full);
 462
 463                 return ret;
 464         }
 465
 466         if (pid == -1) {
 467                 return false;
 468         }
 469         background_lpq_updater_pid = pid;
 470
 471         return true;
 472 }
 473
 474 void printing_subsystem_update(struct tevent_context *ev_ctx,
 475                                struct messaging_context *msg_ctx,
 476                                bool force)
 477 {
 478         if (background_lpq_updater_pid != -1) {
 479                 if (pcap_cache_loaded(NULL)) {
 480                         load_printers(ev_ctx, msg_ctx);
 481                 }
 482                 if (force) {
 483                         /* Send a sighup to the background process.
 484                          * this will force it to reload printers */
 485                         kill(background_lpq_updater_pid, SIGHUP);
 486                 }
 487                 return;
 488         }
 489
 490         pcap_cache_reload(ev_ctx, msg_ctx,
 491                           &delete_and_reload_printers_full);
 492 }