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