diff options
Diffstat (limited to 'source3/printing/samba-bgqd.c')
| -rw-r--r-- | source3/printing/samba-bgqd.c | 359 |
1 files changed, 359 insertions, 0 deletions
diff --git a/source3/printing/samba-bgqd.c b/source3/printing/samba-bgqd.c new file mode 100644 index 0000000..59ed0cc --- /dev/null +++ b/source3/printing/samba-bgqd.c @@ -0,0 +1,359 @@ +/* + * Printing background queue helper + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see <http://www.gnu.org/licenses/>. + */ + +#include "replace.h" +#include "system/filesys.h" +#include "lib/util/server_id.h" +#include "source3/locking/share_mode_lock.h" +#include "source3/param/loadparm.h" +#include "source3/param/param_proto.h" +#include "lib/cmdline/cmdline.h" +#include "lib/cmdline/closefrom_except.h" +#include "lib/util/talloc_stack.h" +#include "lib/util/debug.h" +#include "lib/util/signal.h" +#include "lib/util/fault.h" +#include "lib/util/become_daemon.h" +#include "lib/util/charset/charset.h" +#include "lib/util/samba_util.h" +#include "lib/util/sys_rw.h" +#include "lib/util/pidfile.h" +#include "lib/async_req/async_sock.h" +#include "dynconfig/dynconfig.h" +#include "source3/lib/global_contexts.h" +#include "messages.h" +#include "nsswitch/winbind_client.h" +#include "source3/include/auth.h" +#include "source3/lib/util_procid.h" +#include "source3/auth/proto.h" +#include "source3/printing/queue_process.h" +#include "source3/lib/substitute.h" + +static void watch_handler(struct tevent_req *req) +{ + bool *pdone = tevent_req_callback_data_void(req); + *pdone = true; +} + +static void bgqd_sig_term_handler( + struct tevent_context *ev, + struct tevent_signal *se, + int signum, + int count, + void *siginfo, + void *private_data) +{ + bool *pdone = private_data; + *pdone = true; +} + +static bool ready_signal_filter( + struct messaging_rec *rec, void *private_data) +{ + pid_t pid = getpid(); + ssize_t written; + + if (rec->msg_type != MSG_DAEMON_READY_FD) { + return false; + } + if (rec->num_fds != 1) { + return false; + } + + written = sys_write(rec->fds[0], &pid, sizeof(pid)); + if (written != sizeof(pid)) { + DBG_ERR("Could not write pid: %s\n", strerror(errno)); + } + + return false; +} + +static int samba_bgqd_pidfile_create( + struct messaging_context *msg_ctx, + const char *progname, + int ready_signal_fd) +{ + const char *piddir = lp_pid_directory(); + size_t len = strlen(piddir) + strlen(progname) + 6; + char pidFile[len]; + pid_t existing_pid; + int fd, ret; + + snprintf(pidFile, + sizeof(pidFile), + "%s/%s.pid", + piddir, progname); + + ret = pidfile_path_create(pidFile, &fd, &existing_pid); + if (ret == 0) { + struct tevent_req *ready_signal_req = NULL; + + /* + * Listen for fd's sent via MSG_DAEMON_READY_FD: + * Multiple instances of this process might have raced + * for creating the pidfile. Make sure the parent does + * not suffer from this race, reply on behalf of the + * loser of this race. + */ + + ready_signal_req = messaging_filtered_read_send( + msg_ctx, + messaging_tevent_context(msg_ctx), + msg_ctx, + ready_signal_filter, + NULL); + if (ready_signal_req == NULL) { + DBG_DEBUG("messaging_filtered_read_send failed\n"); + pidfile_unlink(piddir, progname); + pidfile_fd_close(fd); + return ENOMEM; + } + + /* leak fd */ + return 0; + } + + if (ret != EAGAIN) { + DBG_DEBUG("pidfile_path_create() failed: %s\n", + strerror(ret)); + return ret; + } + + DBG_DEBUG("%s pid %d exists\n", progname, (int)existing_pid); + + if (ready_signal_fd != -1) { + /* + * We lost the race for the pidfile, but someone else + * can report readiness on our behalf. + */ + NTSTATUS status = messaging_send_iov( + msg_ctx, + pid_to_procid(existing_pid), + MSG_DAEMON_READY_FD, + NULL, + 0, + &ready_signal_fd, + 1); + if (!NT_STATUS_IS_OK(status)) { + DBG_DEBUG("Could not send ready_signal_fd: %s\n", + nt_errstr(status)); + } + } + + return EAGAIN; +} + +int main(int argc, const char *argv[]) +{ + struct samba_cmdline_daemon_cfg *cmdline_daemon_cfg = NULL; + const struct loadparm_substitution *lp_sub = + loadparm_s3_global_substitution(); + const char *progname = getprogname(); + TALLOC_CTX *frame = NULL; + poptContext pc; + struct messaging_context *msg_ctx = NULL; + struct tevent_context *ev = NULL; + struct tevent_req *watch_req = NULL; + struct tevent_signal *sigterm_handler = NULL; + struct bq_state *bq = NULL; + int log_stdout = 0; + int ready_signal_fd = -1; + int watch_fd = -1; + NTSTATUS status; + int ret; + bool ok; + bool done = false; + int exitcode = 1; + + struct poptOption long_options[] = { + POPT_AUTOHELP + POPT_COMMON_SAMBA + POPT_COMMON_DAEMON + + /* + * File descriptor to write the PID of the helper + * process to + */ + { + .longName = "ready-signal-fd", + .argInfo = POPT_ARG_INT, + .arg = &ready_signal_fd, + .descrip = "Fd to signal readiness to" , + }, + + /* + * Read end of a pipe held open by the parent + * smbd. Exit this process when it becomes readable. + */ + { + .longName = "parent-watch-fd", + .argInfo = POPT_ARG_INT, + .arg = &watch_fd, + .descrip = "Fd to watch for exiting", + }, + POPT_TABLEEND + }; + + { + const char *fd_params[] = { + "ready-signal-fd", "parent-watch-fd", + }; + + closefrom_except_fd_params( + 3, ARRAY_SIZE(fd_params), fd_params, argc, argv); + } + + talloc_enable_null_tracking(); + frame = talloc_stackframe(); + umask(0); + set_remote_machine_name("smbd-bgqd", true); + + ok = samba_cmdline_init(frame, + SAMBA_CMDLINE_CONFIG_SERVER, + true /* require_smbconf */); + if (!ok) { + DBG_ERR("Failed to setup cmdline parser!\n"); + exit(ENOMEM); + } + + cmdline_daemon_cfg = samba_cmdline_get_daemon_cfg(); + + pc = samba_popt_get_context(progname, + argc, + argv, + long_options, + 0); + if (pc == NULL) { + DBG_ERR("Failed to get popt context!\n"); + exit(ENOMEM); + } + + ret = poptGetNextOpt(pc); + if (ret < -1) { + fprintf(stderr, "invalid options: %s\n", poptStrerror(ret)); + goto done; + } + + poptFreeContext(pc); + + log_stdout = (debug_get_log_type() == DEBUG_STDOUT); + + /* main process will notify systemd */ + daemon_sd_notifications(false); + + if (!cmdline_daemon_cfg->fork) { + daemon_status(progname, "Starting process ... "); + } else { + become_daemon(true, + cmdline_daemon_cfg->no_process_group, + log_stdout); + } + + BlockSignals(true, SIGPIPE); + + smb_init_locale(); + dump_core_setup(progname, lp_logfile(frame, lp_sub)); + + msg_ctx = global_messaging_context(); + if (msg_ctx == NULL) { + DBG_ERR("messaging_init() failed\n"); + goto done; + } + ev = messaging_tevent_context(msg_ctx); + + ret = samba_bgqd_pidfile_create(msg_ctx, progname, ready_signal_fd); + if (ret != 0) { + goto done; + } + + if (watch_fd != -1) { + watch_req = wait_for_read_send(ev, ev, watch_fd, true); + if (watch_req == NULL) { + fprintf(stderr, "tevent_add_fd failed\n"); + goto done; + } + tevent_req_set_callback(watch_req, watch_handler, &done); + } + + (void)winbind_off(); + ok = init_guest_session_info(frame); + (void)winbind_on(); + if (!ok) { + DBG_ERR("init_guest_session_info failed\n"); + goto done; + } + + (void)winbind_off(); + status = init_system_session_info(frame); + (void)winbind_on(); + if (!NT_STATUS_IS_OK(status)) { + DBG_ERR("init_system_session_info failed: %s\n", + nt_errstr(status)); + goto done; + } + + sigterm_handler = tevent_add_signal( + ev, frame, SIGTERM, 0, bgqd_sig_term_handler, &done); + if (sigterm_handler == NULL) { + DBG_ERR("Could not install SIGTERM handler\n"); + goto done; + } + + bq = register_printing_bq_handlers(frame, msg_ctx); + if (bq == NULL) { + DBG_ERR("Could not register bq handlers\n"); + goto done; + } + + ok = locking_init(); + if (!ok) { + DBG_ERR("locking_init failed\n"); + goto done; + } + + if (ready_signal_fd != -1) { + pid_t pid = getpid(); + ssize_t written; + + written = sys_write(ready_signal_fd, &pid, sizeof(pid)); + if (written != sizeof(pid)) { + DBG_ERR("Reporting readiness failed\n"); + goto done; + } + close(ready_signal_fd); + ready_signal_fd = -1; + } + + while (!done) { + TALLOC_CTX *tmp = talloc_stackframe(); + ret = tevent_loop_once(ev); + TALLOC_FREE(tmp); + if (ret != 0) { + DBG_ERR("tevent_loop_once failed\n"); + break; + } + } + + exitcode = 0; +done: + TALLOC_FREE(watch_req); + TALLOC_FREE(bq); + TALLOC_FREE(sigterm_handler); + global_messaging_context_free(); + TALLOC_FREE(frame); + return exitcode; +} |