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