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 "locking/proto.h"
  31 #include "smbd/smbd.h"
  32 #include "rpc_server/rpc_config.h"
  33 #include "printing/load.h"
  34 #include "rpc_server/spoolss/srv_spoolss_nt.h"
  35 #include "auth.h"
  36 #include "nt_printing.h"
  37 #include "util_event.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();
 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         messaging_send_all(msg_ctx, MSG_PRINTER_PCAP, NULL, 0);
 148 }
 149
 150 struct bq_state {
 151         struct tevent_context *ev;
 152         struct messaging_context *msg;
 153         struct idle_event *housekeep;
 154 };
 155
 156 static bool print_queue_housekeeping(const struct timeval *now, void *pvt)
 157 {
 158         struct bq_state *state;
 159
 160         state = talloc_get_type_abort(pvt, struct bq_state);
 161
 162         DEBUG(5, ("print queue housekeeping\n"));
 163         pcap_cache_reload(state->ev, state->msg, &reload_pcap_change_notify);
 164
 165         return true;
 166 }
 167
 168 static bool printing_subsystem_queue_tasks(struct bq_state *state)
 169 {
 170         uint32_t housekeeping_period = lp_printcap_cache_time();
 171
 172         /* cancel any existing housekeeping event */
 173         TALLOC_FREE(state->housekeep);
 174
 175         if (housekeeping_period == 0) {
 176                 DEBUG(4, ("background print queue housekeeping disabled\n"));
 177                 return true;
 178         }
 179
 180         state->housekeep = event_add_idle(state->ev, NULL,
 181                                           timeval_set(housekeeping_period, 0),
 182                                           "print_queue_housekeeping",
 183                                           print_queue_housekeeping, state);
 184         if (state->housekeep == NULL) {
 185                 DEBUG(0,("Could not add print_queue_housekeeping event\n"));
 186                 return false;
 187         }
 188
 189         return true;
 190 }
 191
 192 static void bq_reopen_logs(char *logfile)
 193 {
 194         if (logfile) {
 195                 lp_set_logfile(logfile);
 196         }
 197         reopen_logs();
 198 }
 199
 200 static void bq_sig_term_handler(struct tevent_context *ev,
 201                                 struct tevent_signal *se,
 202                                 int signum,
 203                                 int count,
 204                                 void *siginfo,
 205                                 void *private_data)
 206 {
 207         exit_server_cleanly("termination signal");
 208 }
 209
 210 static void bq_setup_sig_term_handler(void)
 211 {
 212         struct tevent_signal *se;
 213
 214         se = tevent_add_signal(global_event_context(),
 215                                global_event_context(),
 216                                SIGTERM, 0,
 217                                bq_sig_term_handler,
 218                                NULL);
 219         if (!se) {
 220                 exit_server("failed to setup SIGTERM handler");
 221         }
 222 }
 223
 224 static void bq_sig_hup_handler(struct tevent_context *ev,
 225                                 struct tevent_signal *se,
 226                                 int signum,
 227                                 int count,
 228                                 void *siginfo,
 229                                 void *pvt)
 230 {
 231         struct bq_state *state;
 232
 233         state = talloc_get_type_abort(pvt, struct bq_state);
 234         change_to_root_user();
 235
 236         DEBUG(1, ("Reloading pcap cache after SIGHUP\n"));
 237         pcap_cache_reload(state->ev, state->msg,
 238                           &reload_pcap_change_notify);
 239         printing_subsystem_queue_tasks(state);
 240         bq_reopen_logs(NULL);
 241 }
 242
 243 static void bq_setup_sig_hup_handler(struct bq_state *state)
 244 {
 245         struct tevent_signal *se;
 246
 247         se = tevent_add_signal(state->ev, state->ev, SIGHUP, 0,
 248                                bq_sig_hup_handler, state);
 249         if (!se) {
 250                 exit_server("failed to setup SIGHUP handler");
 251         }
 252 }
 253
 254 static void bq_sig_chld_handler(struct tevent_context *ev_ctx,
 255                                 struct tevent_signal *se,
 256                                 int signum, int count,
 257                                 void *siginfo, void *pvt)
 258 {
 259         int status;
 260         pid_t pid;
 261
 262         pid = waitpid(-1, &status, WNOHANG);
 263         if (WIFEXITED(status)) {
 264                 DEBUG(6, ("Bq child process %d terminated with %d\n",
 265                           (int)pid, WEXITSTATUS(status)));
 266         } else {
 267                 DEBUG(3, ("Bq child process %d terminated abnormally\n",
 268                           (int)pid));
 269         }
 270 }
 271
 272 static void bq_setup_sig_chld_handler(struct tevent_context *ev_ctx)
 273 {
 274         struct tevent_signal *se;
 275
 276         se = tevent_add_signal(ev_ctx, ev_ctx, SIGCHLD, 0,
 277                                 bq_sig_chld_handler, NULL);
 278         if (!se) {
 279                 exit_server("failed to setup SIGCHLD handler");
 280         }
 281 }
 282
 283 static void bq_smb_conf_updated(struct messaging_context *msg_ctx,
 284                                 void *private_data,
 285                                 uint32_t msg_type,
 286                                 struct server_id server_id,
 287                                 DATA_BLOB *data)
 288 {
 289         struct bq_state *state;
 290
 291         state = talloc_get_type_abort(private_data, struct bq_state);
 292
 293         DEBUG(10,("smb_conf_updated: Got message saying smb.conf was "
 294                   "updated. Reloading.\n"));
 295         change_to_root_user();
 296         pcap_cache_reload(state->ev, msg_ctx, &reload_pcap_change_notify);
 297         printing_subsystem_queue_tasks(state);
 298 }
 299
 300 static void printing_pause_fd_handler(struct tevent_context *ev,
 301                                       struct tevent_fd *fde,
 302                                       uint16_t flags,
 303                                       void *private_data)
 304 {
 305         /*
 306          * If pause_pipe[1] is closed it means the parent smbd
 307          * and children exited or aborted.
 308          */
 309         exit_server_cleanly(NULL);
 310 }
 311
 312 /****************************************************************************
 313 main thread of the background lpq updater
 314 ****************************************************************************/
 315 pid_t start_background_queue(struct tevent_context *ev,
 316                              struct messaging_context *msg_ctx,
 317                              char *logfile)
 318 {
 319         pid_t pid;
 320         struct bq_state *state;
 321
 322         /* Use local variables for this as we don't
 323          * need to save the parent side of this, just
 324          * ensure it closes when the process exits.
 325          */
 326         int pause_pipe[2];
 327
 328         DEBUG(3,("start_background_queue: Starting background LPQ thread\n"));
 329
 330         if (pipe(pause_pipe) == -1) {
 331                 DEBUG(5,("start_background_queue: cannot create pipe. %s\n", strerror(errno) ));
 332                 exit(1);
 333         }
 334
 335         /*
 336          * Block signals before forking child as it will have to
 337          * set its own handlers. Child will re-enable SIGHUP as
 338          * soon as the handlers are set up.
 339          */
 340         BlockSignals(true, SIGTERM);
 341         BlockSignals(true, SIGHUP);
 342
 343         pid = fork();
 344
 345         /* parent or error */
 346         if (pid != 0) {
 347                 /* Re-enable SIGHUP before returnig */
 348                 BlockSignals(false, SIGTERM);
 349                 BlockSignals(false, SIGHUP);
 350                 return pid;
 351         }
 352
 353         if (pid == -1) {
 354                 DEBUG(5,("start_background_queue: background LPQ thread failed to start. %s\n", strerror(errno) ));
 355                 exit(1);
 356         }
 357
 358         if (pid == 0) {
 359                 struct tevent_fd *fde;
 360                 int ret;
 361                 NTSTATUS status;
 362
 363                 /* Child. */
 364                 DEBUG(5,("start_background_queue: background LPQ thread started\n"));
 365
 366                 close(pause_pipe[0]);
 367                 pause_pipe[0] = -1;
 368
 369                 status = smbd_reinit_after_fork(msg_ctx, ev, true, "lpqd");
 370
 371                 if (!NT_STATUS_IS_OK(status)) {
 372                         DEBUG(0,("reinit_after_fork() failed\n"));
 373                         smb_panic("reinit_after_fork() failed");
 374                 }
 375
 376                 state = talloc_zero(NULL, struct bq_state);
 377                 if (state == NULL) {
 378                         exit(1);
 379                 }
 380                 state->ev = ev;
 381                 state->msg = msg_ctx;
 382
 383                 bq_reopen_logs(logfile);
 384                 bq_setup_sig_term_handler();
 385                 bq_setup_sig_hup_handler(state);
 386                 bq_setup_sig_chld_handler(ev);
 387
 388                 BlockSignals(false, SIGTERM);
 389                 BlockSignals(false, SIGHUP);
 390
 391                 if (!printing_subsystem_queue_tasks(state)) {
 392                         exit(1);
 393                 }
 394
 395                 if (!locking_init()) {
 396                         exit(1);
 397                 }
 398                 messaging_register(msg_ctx, state, MSG_SMB_CONF_UPDATED,
 399                                    bq_smb_conf_updated);
 400                 messaging_register(msg_ctx, NULL, MSG_PRINTER_UPDATE,
 401                                    print_queue_receive);
 402                 /* Remove previous forwarder message set in parent. */
 403                 messaging_deregister(msg_ctx, MSG_PRINTER_DRVUPGRADE, NULL);
 404
 405                 messaging_register(msg_ctx, NULL, MSG_PRINTER_DRVUPGRADE,
 406                                    do_drv_upgrade_printer);
 407
 408                 fde = tevent_add_fd(ev, ev, pause_pipe[1], TEVENT_FD_READ,
 409                                     printing_pause_fd_handler,
 410                                     NULL);
 411                 if (!fde) {
 412                         DEBUG(0,("tevent_add_fd() failed for pause_pipe\n"));
 413                         smb_panic("tevent_add_fd() failed for pause_pipe");
 414                 }
 415
 416                 pcap_cache_reload(ev, msg_ctx, &reload_pcap_change_notify);
 417
 418                 DEBUG(5,("start_background_queue: background LPQ thread waiting for messages\n"));
 419                 ret = tevent_loop_wait(ev);
 420                 /* should not be reached */
 421                 DEBUG(0,("background_queue: tevent_loop_wait() exited with %d - %s\n",
 422                          ret, (ret == 0) ? "out of events" : strerror(errno)));
 423                 exit(1);
 424         }
 425
 426         close(pause_pipe[1]);
 427
 428         return pid;
 429 }
 430
 431 /* Run before the parent forks */
 432 bool printing_subsystem_init(struct tevent_context *ev_ctx,
 433                              struct messaging_context *msg_ctx,
 434                              bool start_daemons,
 435                              bool background_queue)
 436 {
 437         pid_t pid = -1;
 438
 439         if (!print_backend_init(msg_ctx)) {
 440                 return false;
 441         }
 442
 443         /* start spoolss daemon */
 444         /* start as a separate daemon only if enabled */
 445         if (start_daemons && rpc_spoolss_daemon() == RPC_DAEMON_FORK) {
 446
 447                 pid = start_spoolssd(ev_ctx, msg_ctx);
 448
 449         } else if (start_daemons && background_queue) {
 450
 451                 pid = start_background_queue(ev_ctx, msg_ctx, NULL);
 452
 453         } else {
 454                 bool ret;
 455                 struct bq_state *state;
 456
 457                 state = talloc_zero(NULL, struct bq_state);
 458                 if (state == NULL) {
 459                         exit(1);
 460                 }
 461                 state->ev = ev_ctx;
 462                 state->msg = msg_ctx;
 463
 464                 ret = printing_subsystem_queue_tasks(state);
 465
 466                 /* Publish nt printers, this requires a working winreg pipe */
 467                 pcap_cache_reload(ev_ctx, msg_ctx,
 468                                   &delete_and_reload_printers_full);
 469
 470                 return ret;
 471         }
 472
 473         if (pid == -1) {
 474                 return false;
 475         }
 476         background_lpq_updater_pid = pid;
 477
 478         return true;
 479 }
 480
 481 void printing_subsystem_update(struct tevent_context *ev_ctx,
 482                                struct messaging_context *msg_ctx,
 483                                bool force)
 484 {
 485         if (background_lpq_updater_pid != -1) {
 486                 if (pcap_cache_loaded(NULL)) {
 487                         load_printers();
 488                 }
 489                 if (force) {
 490                         /* Send a sighup to the background process.
 491                          * this will force it to reload printers */
 492                         kill(background_lpq_updater_pid, SIGHUP);
 493                 }
 494                 return;
 495         }
 496
 497         pcap_cache_reload(ev_ctx, msg_ctx,
 498                           &delete_and_reload_printers_full);
 499 }