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 "printing.h"
  27 #include "printing/pcap.h"
  28 #include "printing/queue_process.h"
  29 #include "serverid.h"
  30 #include "locking/proto.h"
  31 #include "smbd/smbd.h"
  32 #include "rpc_server/rpc_config.h"
  33 #include "printing/load.h"
  34
  35 extern pid_t start_spoolssd(struct event_context *ev_ctx,
  36                             struct messaging_context *msg_ctx);
  37
  38 /****************************************************************************
  39  Notify smbds of new printcap data
  40 **************************************************************************/
  41 static void reload_pcap_change_notify(struct tevent_context *ev,
  42                                struct messaging_context *msg_ctx)
  43 {
  44         /*
  45          * Reload the printers first in the background process so that
  46          * newly added printers get default values created in the registry.
  47          *
  48          * This will block the process for some time (~1 sec per printer), but
  49          * it doesn't block smbd's servering clients.
  50          */
  51         delete_and_reload_printers(ev, msg_ctx);
  52
  53         message_send_all(msg_ctx, MSG_PRINTER_PCAP, NULL, 0, NULL);
  54 }
  55
  56 struct printing_queue_housekeeping_state {
  57         struct tevent_context *ev;
  58         struct messaging_context *msg;
  59 };
  60
  61 static bool print_queue_housekeeping(const struct timeval *now, void *pvt)
  62 {
  63         struct printing_queue_housekeeping_state *state =
  64                 talloc_get_type_abort(pvt,
  65                 struct printing_queue_housekeeping_state);
  66         time_t printcap_cache_time = (time_t)lp_printcap_cache_time();
  67         time_t t = time_mono(NULL);
  68
  69         DEBUG(5, ("print queue housekeeping\n"));
  70
  71         /* if periodic printcap rescan is enabled,
  72          * see if it's time to reload */
  73         if ((printcap_cache_time != 0) &&
  74             (t >= (last_printer_reload_time + printcap_cache_time))) {
  75                 DEBUG( 3,( "Printcap cache time expired.\n"));
  76                 pcap_cache_reload(state->ev, state->msg,
  77                                   &reload_pcap_change_notify);
  78                 last_printer_reload_time = t;
  79         }
  80
  81         return true;
  82 }
  83
  84 static bool printing_subsystem_queue_tasks(struct tevent_context *ev_ctx,
  85                                            struct messaging_context *msg_ctx)
  86 {
  87         struct printing_queue_housekeeping_state *state;
  88
  89         state = talloc_zero(ev_ctx, struct printing_queue_housekeeping_state);
  90         if (state == NULL) {
  91                 DEBUG(0,("Could not talloc printing_queue_housekeeping_state\n"));
  92                 return false;
  93         }
  94         state->ev = ev_ctx;
  95         state->msg = msg_ctx;
  96
  97         if (!(event_add_idle(ev_ctx, NULL,
  98                              timeval_set(SMBD_HOUSEKEEPING_INTERVAL, 0),
  99                              "print_queue_housekeeping",
 100                              print_queue_housekeeping,
 101                              state))) {
 102                 DEBUG(0,("Could not add print_queue_housekeeping event\n"));
 103                 return false;
 104         }
 105
 106         return true;
 107 }
 108
 109 static void bq_reopen_logs(char *logfile)
 110 {
 111         if (logfile) {
 112                 lp_set_logfile(logfile);
 113         }
 114         reopen_logs();
 115 }
 116
 117 static void bq_sig_term_handler(struct tevent_context *ev,
 118                                 struct tevent_signal *se,
 119                                 int signum,
 120                                 int count,
 121                                 void *siginfo,
 122                                 void *private_data)
 123 {
 124         exit_server_cleanly("termination signal");
 125 }
 126
 127 static void bq_setup_sig_term_handler(void)
 128 {
 129         struct tevent_signal *se;
 130
 131         se = tevent_add_signal(server_event_context(),
 132                                server_event_context(),
 133                                SIGTERM, 0,
 134                                bq_sig_term_handler,
 135                                NULL);
 136         if (!se) {
 137                 exit_server("failed to setup SIGTERM handler");
 138         }
 139 }
 140
 141 static void bq_sig_hup_handler(struct tevent_context *ev,
 142                                 struct tevent_signal *se,
 143                                 int signum,
 144                                 int count,
 145                                 void *siginfo,
 146                                 void *pvt)
 147 {
 148         struct messaging_context *msg_ctx;
 149
 150         msg_ctx = talloc_get_type_abort(pvt, struct messaging_context);
 151         change_to_root_user();
 152
 153         DEBUG(1, ("Reloading pcap cache after SIGHUP\n"));
 154         pcap_cache_reload(ev, msg_ctx, &reload_pcap_change_notify);
 155         bq_reopen_logs(NULL);
 156 }
 157
 158 static void bq_setup_sig_hup_handler(struct tevent_context *ev,
 159                                      struct messaging_context *msg_ctx)
 160 {
 161         struct tevent_signal *se;
 162
 163         se = tevent_add_signal(ev, ev, SIGHUP, 0, bq_sig_hup_handler,
 164                                msg_ctx);
 165         if (!se) {
 166                 exit_server("failed to setup SIGHUP handler");
 167         }
 168 }
 169
 170 static void bq_sig_chld_handler(struct tevent_context *ev_ctx,
 171                                 struct tevent_signal *se,
 172                                 int signum, int count,
 173                                 void *siginfo, void *pvt)
 174 {
 175         int status;
 176         pid_t pid;
 177
 178         pid = sys_waitpid(-1, &status, WNOHANG);
 179         if (WIFEXITED(status)) {
 180                 DEBUG(6, ("Bq child process %d terminated with %d\n",
 181                           (int)pid, WEXITSTATUS(status)));
 182         } else {
 183                 DEBUG(3, ("Bq child process %d terminated abnormally\n",
 184                           (int)pid));
 185         }
 186 }
 187
 188 static void bq_setup_sig_chld_handler(struct tevent_context *ev_ctx)
 189 {
 190         struct tevent_signal *se;
 191
 192         se = tevent_add_signal(ev_ctx, ev_ctx, SIGCHLD, 0,
 193                                 bq_sig_chld_handler, NULL);
 194         if (!se) {
 195                 exit_server("failed to setup SIGCHLD handler");
 196         }
 197 }
 198
 199 static void bq_smb_conf_updated(struct messaging_context *msg_ctx,
 200                                 void *private_data,
 201                                 uint32_t msg_type,
 202                                 struct server_id server_id,
 203                                 DATA_BLOB *data)
 204 {
 205         struct tevent_context *ev_ctx =
 206                 talloc_get_type_abort(private_data, struct tevent_context);
 207
 208         DEBUG(10,("smb_conf_updated: Got message saying smb.conf was "
 209                   "updated. Reloading.\n"));
 210         change_to_root_user();
 211         pcap_cache_reload(ev_ctx, msg_ctx, &reload_pcap_change_notify);
 212 }
 213
 214 static void printing_pause_fd_handler(struct tevent_context *ev,
 215                                       struct tevent_fd *fde,
 216                                       uint16_t flags,
 217                                       void *private_data)
 218 {
 219         /*
 220          * If pause_pipe[1] is closed it means the parent smbd
 221          * and children exited or aborted.
 222          */
 223         exit_server_cleanly(NULL);
 224 }
 225
 226 /****************************************************************************
 227 main thread of the background lpq updater
 228 ****************************************************************************/
 229 pid_t start_background_queue(struct tevent_context *ev,
 230                              struct messaging_context *msg_ctx,
 231                              char *logfile)
 232 {
 233         pid_t pid;
 234
 235         /* Use local variables for this as we don't
 236          * need to save the parent side of this, just
 237          * ensure it closes when the process exits.
 238          */
 239         int pause_pipe[2];
 240
 241         DEBUG(3,("start_background_queue: Starting background LPQ thread\n"));
 242
 243         if (pipe(pause_pipe) == -1) {
 244                 DEBUG(5,("start_background_queue: cannot create pipe. %s\n", strerror(errno) ));
 245                 exit(1);
 246         }
 247
 248         /*
 249          * Block signals before forking child as it will have to
 250          * set its own handlers. Child will re-enable SIGHUP as
 251          * soon as the handlers are set up.
 252          */
 253         BlockSignals(true, SIGTERM);
 254         BlockSignals(true, SIGHUP);
 255
 256         pid = fork();
 257
 258         /* parent or error */
 259         if (pid != 0) {
 260                 /* Re-enable SIGHUP before returnig */
 261                 BlockSignals(false, SIGTERM);
 262                 BlockSignals(false, SIGHUP);
 263                 return pid;
 264         }
 265
 266         if (pid == -1) {
 267                 DEBUG(5,("start_background_queue: background LPQ thread failed to start. %s\n", strerror(errno) ));
 268                 exit(1);
 269         }
 270
 271         if (pid == 0) {
 272                 struct tevent_fd *fde;
 273                 int ret;
 274                 NTSTATUS status;
 275
 276                 /* Child. */
 277                 DEBUG(5,("start_background_queue: background LPQ thread started\n"));
 278
 279                 close(pause_pipe[0]);
 280                 pause_pipe[0] = -1;
 281
 282                 status = reinit_after_fork(msg_ctx, ev, true);
 283
 284                 if (!NT_STATUS_IS_OK(status)) {
 285                         DEBUG(0,("reinit_after_fork() failed\n"));
 286                         smb_panic("reinit_after_fork() failed");
 287                 }
 288
 289                 bq_reopen_logs(logfile);
 290                 bq_setup_sig_term_handler();
 291                 bq_setup_sig_hup_handler(ev, msg_ctx);
 292                 bq_setup_sig_chld_handler(ev);
 293
 294                 BlockSignals(false, SIGTERM);
 295                 BlockSignals(false, SIGHUP);
 296
 297                 if (!printing_subsystem_queue_tasks(ev, msg_ctx)) {
 298                         exit(1);
 299                 }
 300
 301                 if (!serverid_register(messaging_server_id(msg_ctx),
 302                                        FLAG_MSG_GENERAL |
 303                                        FLAG_MSG_PRINT_GENERAL)) {
 304                         exit(1);
 305                 }
 306
 307                 if (!locking_init()) {
 308                         exit(1);
 309                 }
 310                 messaging_register(msg_ctx, ev, MSG_SMB_CONF_UPDATED,
 311                                    bq_smb_conf_updated);
 312                 messaging_register(msg_ctx, NULL, MSG_PRINTER_UPDATE,
 313                                    print_queue_receive);
 314
 315                 fde = tevent_add_fd(ev, ev, pause_pipe[1], TEVENT_FD_READ,
 316                                     printing_pause_fd_handler,
 317                                     NULL);
 318                 if (!fde) {
 319                         DEBUG(0,("tevent_add_fd() failed for pause_pipe\n"));
 320                         smb_panic("tevent_add_fd() failed for pause_pipe");
 321                 }
 322
 323                 pcap_cache_reload(ev, msg_ctx, &reload_pcap_change_notify);
 324
 325                 DEBUG(5,("start_background_queue: background LPQ thread waiting for messages\n"));
 326                 ret = tevent_loop_wait(ev);
 327                 /* should not be reached */
 328                 DEBUG(0,("background_queue: tevent_loop_wait() exited with %d - %s\n",
 329                          ret, (ret == 0) ? "out of events" : strerror(errno)));
 330                 exit(1);
 331         }
 332
 333         close(pause_pipe[1]);
 334
 335         return pid;
 336 }
 337
 338 /* Run before the parent forks */
 339 bool printing_subsystem_init(struct tevent_context *ev_ctx,
 340                              struct messaging_context *msg_ctx,
 341                              bool start_daemons,
 342                              bool background_queue)
 343 {
 344         pid_t pid = -1;
 345
 346         if (!print_backend_init(msg_ctx)) {
 347                 return false;
 348         }
 349
 350         /* start spoolss daemon */
 351         /* start as a separate daemon only if enabled */
 352         if (start_daemons && rpc_spoolss_daemon() == RPC_DAEMON_FORK) {
 353
 354                 pid = start_spoolssd(ev_ctx, msg_ctx);
 355
 356         } else if (start_daemons && background_queue) {
 357
 358                 pid = start_background_queue(ev_ctx, msg_ctx, NULL);
 359
 360         } else {
 361                 bool ret;
 362
 363                 ret = printing_subsystem_queue_tasks(ev_ctx, msg_ctx);
 364
 365                 /* Publish nt printers, this requires a working winreg pipe */
 366                 pcap_cache_reload(ev_ctx, msg_ctx, &delete_and_reload_printers);
 367
 368                 return ret;
 369         }
 370
 371         if (pid == -1) {
 372                 return false;
 373         }
 374         background_lpq_updater_pid = pid;
 375
 376         return true;
 377 }
 378
 379 void printing_subsystem_update(struct tevent_context *ev_ctx,
 380                                struct messaging_context *msg_ctx,
 381                                bool force)
 382 {
 383         if (background_lpq_updater_pid != -1) {
 384                 if (pcap_cache_loaded()) {
 385                         load_printers(ev_ctx, msg_ctx);
 386                 }
 387                 if (force) {
 388                         /* Send a sighup to the background process.
 389                          * this will force it to reload printers */
 390                         kill(background_lpq_updater_pid, SIGHUP);
 391                 }
 392                 return;
 393         }
 394
 395         pcap_cache_reload(ev_ctx, msg_ctx, &delete_and_reload_printers);
 396 }