s3: smbd: Allow fchmod from the NFS-style mode ACL in set_nt_acl() for a SMB2 POSIX...

[Samba.git] / source3 / printing / queue_process.c

/*
   Unix SMB/Netbios implementation.
   Version 3.0
   printing backend routines
   Copyright (C) Andrew Tridgell 1992-2000
   Copyright (C) Jeremy Allison 2002
   Copyright (C) Simo Sorce 2011

   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 "includes.h"
#include <spawn.h>
#include "smbd/globals.h"
#include "include/messages.h"
#include "lib/util/util_process.h"
#include "lib/util/sys_rw.h"
#include "printing.h"
#include "printing/pcap.h"
#include "printing/printer_list.h"
#include "printing/queue_process.h"
#include "locking/proto.h"
#include "locking/share_mode_lock.h"
#include "smbd/smbd.h"
#include "rpc_server/rpc_config.h"
#include "printing/load.h"
#include "rpc_server/spoolss/srv_spoolss_nt.h"
#include "auth.h"
#include "nt_printing.h"
#include "util_event.h"
#include "lib/global_contexts.h"
#include "lib/util/pidfile.h"

/**
 * @brief Purge stale printers and reload from pre-populated pcap cache.
 *
 * This function should normally only be called as a callback on a successful
 * pcap_cache_reload().
 *
 * This function can cause DELETION of printers and drivers from our registry,
 * so calling it on a failed pcap reload may REMOVE permanently all printers
 * and drivers.
 *
 * @param[in] ev        The event context.
 *
 * @param[in] msg_ctx   The messaging context.
 */
static void delete_and_reload_printers_full(struct tevent_context *ev,
                                            struct messaging_context *msg_ctx)
{
        struct auth_session_info *session_info = NULL;
        struct spoolss_PrinterInfo2 *pinfo2 = NULL;
        const struct loadparm_substitution *lp_sub =
                loadparm_s3_global_substitution();
        int n_services;
        int pnum;
        int snum;
        const char *pname;
        const char *sname;
        NTSTATUS status;

        n_services = lp_numservices();
        pnum = lp_servicenumber(PRINTERS_NAME);

        status = make_session_info_system(talloc_tos(), &session_info);
        if (!NT_STATUS_IS_OK(status)) {
                DEBUG(3, ("reload_printers: "
                          "Could not create system session_info\n"));
                /* can't remove stale printers before we
                 * are fully initialized */
                return;
        }

        /*
         * Add default config for printers added to smb.conf file and remove
         * stale printers
         */
        for (snum = 0; snum < n_services; snum++) {
                /* avoid removing PRINTERS_NAME */
                if (snum == pnum) {
                        continue;
                }

                /* skip no-printer services */
                if (!snum_is_shared_printer(snum)) {
                        continue;
                }

                sname = lp_const_servicename(snum);
                pname = lp_printername(session_info, lp_sub, snum);

                /* check printer, but avoid removing non-autoloaded printers */
                if (lp_autoloaded(snum) &&
                    !printer_list_printername_exists(pname)) {
                        DEBUG(3, ("removing stale printer %s\n", pname));

                        if (is_printer_published(session_info, session_info,
                                                 msg_ctx,
                                                 NULL,
                                                 lp_servicename(session_info,
                                                                lp_sub,
                                                                snum),
                                                 &pinfo2)) {
                                nt_printer_publish(session_info,
                                                   session_info,
                                                   msg_ctx,
                                                   pinfo2,
                                                   DSPRINT_UNPUBLISH);
                                TALLOC_FREE(pinfo2);
                        }
                        nt_printer_remove(session_info, session_info, msg_ctx,
                                          pname);
                } else {
                        DEBUG(8, ("Adding default registry entry for printer "
                                  "[%s], if it doesn't exist.\n", sname));
                        nt_printer_add(session_info, session_info, msg_ctx,
                                       sname);
                }
        }

        /* finally, purge old snums */
        delete_and_reload_printers();

        TALLOC_FREE(session_info);
}


/****************************************************************************
 Notify smbds of new printcap data
**************************************************************************/
static void reload_pcap_change_notify(struct tevent_context *ev,
                               struct messaging_context *msg_ctx)
{
        /*
         * Reload the printers first in the background process so that
         * newly added printers get default values created in the registry.
         *
         * This will block the process for some time (~1 sec per printer), but
         * it doesn't block smbd's serving clients.
         */
        delete_and_reload_printers_full(ev, msg_ctx);

        messaging_send_all(msg_ctx, MSG_PRINTER_PCAP, NULL, 0);
}

struct bq_state {
        struct tevent_context *ev;
        struct messaging_context *msg;
        struct idle_event *housekeep;
        struct tevent_signal *sighup_handler;
        struct tevent_signal *sigchld_handler;
};

static bool print_queue_housekeeping(const struct timeval *now, void *pvt)
{
        struct bq_state *state;

        state = talloc_get_type_abort(pvt, struct bq_state);

        DEBUG(5, ("print queue housekeeping\n"));
        pcap_cache_reload(state->ev, state->msg, reload_pcap_change_notify);

        return true;
}

static bool printing_subsystem_queue_tasks(struct bq_state *state)
{
        uint32_t housekeeping_period = lp_printcap_cache_time();

        /* cancel any existing housekeeping event */
        TALLOC_FREE(state->housekeep);

        if ((housekeeping_period == 0) || !lp_load_printers()) {
                DEBUG(4, ("background print queue housekeeping disabled\n"));
                return true;
        }

        state->housekeep = event_add_idle(state->ev, NULL,
                                          timeval_set(housekeeping_period, 0),
                                          "print_queue_housekeeping",
                                          print_queue_housekeeping, state);
        if (state->housekeep == NULL) {
                DEBUG(0,("Could not add print_queue_housekeeping event\n"));
                return false;
        }

        return true;
}

static void bq_reopen_logs(char *logfile)
{
        if (logfile) {
                lp_set_logfile(logfile);
        }
        reopen_logs();
}

static void bq_sig_hup_handler(struct tevent_context *ev,
                                struct tevent_signal *se,
                                int signum,
                                int count,
                                void *siginfo,
                                void *pvt)
{
        struct bq_state *state;

        state = talloc_get_type_abort(pvt, struct bq_state);
        change_to_root_user();

        DEBUG(1, ("Reloading pcap cache after SIGHUP\n"));
        pcap_cache_reload(state->ev, state->msg,
                          reload_pcap_change_notify);
        printing_subsystem_queue_tasks(state);
        bq_reopen_logs(NULL);
}

static void bq_sig_chld_handler(struct tevent_context *ev_ctx,
                                struct tevent_signal *se,
                                int signum, int count,
                                void *siginfo, void *pvt)
{
        int status;
        pid_t pid;

        do {
                do {
                        pid = waitpid(-1, &status, WNOHANG);
                } while ((pid == -1) && (errno == EINTR));

                if (WIFEXITED(status)) {
                        DBG_INFO("Bq child process %d terminated with %d\n",
                                 (int)pid,
                                 WEXITSTATUS(status));
                } else {
                        DBG_NOTICE("Bq child process %d terminated abnormally\n",
                                   (int)pid);
                }
        } while (pid > 0);
}

static void bq_smb_conf_updated(struct messaging_context *msg_ctx,
                                void *private_data,
                                uint32_t msg_type,
                                struct server_id server_id,
                                DATA_BLOB *data)
{
        struct bq_state *state;

        state = talloc_get_type_abort(private_data, struct bq_state);

        DEBUG(10,("smb_conf_updated: Got message saying smb.conf was "
                  "updated. Reloading.\n"));
        change_to_root_user();
        pcap_cache_reload(state->ev, msg_ctx, reload_pcap_change_notify);
        printing_subsystem_queue_tasks(state);
}

static int bq_state_destructor(struct bq_state *s)
{
        struct messaging_context *msg_ctx = s->msg;
        TALLOC_FREE(s->sighup_handler);
        TALLOC_FREE(s->sigchld_handler);
        messaging_deregister(msg_ctx, MSG_PRINTER_DRVUPGRADE, NULL);
        messaging_deregister(msg_ctx, MSG_PRINTER_UPDATE, NULL);
        messaging_deregister(msg_ctx, MSG_SMB_CONF_UPDATED, s);
        return 0;
}

struct bq_state *register_printing_bq_handlers(
        TALLOC_CTX *mem_ctx,
        struct messaging_context *msg_ctx)
{
        struct bq_state *state = NULL;
        NTSTATUS status;
        bool ok;

        state = talloc_zero(mem_ctx, struct bq_state);
        if (state == NULL) {
                return NULL;
        }
        state->ev = messaging_tevent_context(msg_ctx);
        state->msg = msg_ctx;

        status = messaging_register(
                msg_ctx, state, MSG_SMB_CONF_UPDATED, bq_smb_conf_updated);
        if (!NT_STATUS_IS_OK(status)) {
                goto fail;
        }
        status = messaging_register(
                msg_ctx, NULL, MSG_PRINTER_UPDATE, print_queue_receive);
        if (!NT_STATUS_IS_OK(status)) {
                goto fail_dereg_smb_conf_updated;
        }
        status = messaging_register(
                msg_ctx, NULL, MSG_PRINTER_DRVUPGRADE, do_drv_upgrade_printer);
        if (!NT_STATUS_IS_OK(status)) {
                goto fail_dereg_printer_update;
        }

        state->sighup_handler = tevent_add_signal(
                state->ev, state, SIGHUP, 0, bq_sig_hup_handler, state);
        if (state->sighup_handler == NULL) {
                goto fail_dereg_printer_drvupgrade;
        }
        state->sigchld_handler = tevent_add_signal(
                state->ev, state, SIGCHLD, 0, bq_sig_chld_handler, NULL);
        if (state->sigchld_handler == NULL) {
                goto fail_free_handlers;
        }

        /* Initialize the printcap cache as soon as the daemon starts. */
        pcap_cache_reload(state->ev, state->msg, reload_pcap_change_notify);

        ok = printing_subsystem_queue_tasks(state);
        if (!ok) {
                goto fail_free_handlers;
        }

        talloc_set_destructor(state, bq_state_destructor);

        return state;

fail_free_handlers:
        TALLOC_FREE(state->sighup_handler);
        TALLOC_FREE(state->sigchld_handler);
fail_dereg_printer_drvupgrade:
        messaging_deregister(msg_ctx, MSG_PRINTER_DRVUPGRADE, NULL);
fail_dereg_printer_update:
        messaging_deregister(msg_ctx, MSG_PRINTER_UPDATE, NULL);
fail_dereg_smb_conf_updated:
        messaging_deregister(msg_ctx, MSG_SMB_CONF_UPDATED, state);
fail:
        TALLOC_FREE(state);
        return NULL;
}

/****************************************************************************
main thread of the background lpq updater
****************************************************************************/
pid_t start_background_queue(struct tevent_context *ev,
                             struct messaging_context *msg_ctx,
                             char *logfile)
{
        pid_t pid;
        int ret;
        ssize_t nread;
        char **argv = NULL;
        int ready_fds[2];

        DEBUG(3,("start_background_queue: Starting background LPQ thread\n"));

        ret = pipe(ready_fds);
        if (ret == -1) {
                return -1;
        }

        argv = str_list_make_empty(talloc_tos());
        str_list_add_printf(
                &argv, "%s/samba-bgqd", get_dyn_SAMBA_LIBEXECDIR());
        str_list_add_printf(
                &argv, "--ready-signal-fd=%d", ready_fds[1]);
        str_list_add_printf(
                &argv, "--parent-watch-fd=%d", 0);
        str_list_add_printf(
                &argv, "--debuglevel=%d", debuglevel_get_class(DBGC_RPC_SRV));
        if (!is_default_dyn_CONFIGFILE()) {
                str_list_add_printf(
                        &argv, "--configfile=%s", get_dyn_CONFIGFILE());
        }
        if (!is_default_dyn_LOGFILEBASE()) {
                str_list_add_printf(
                        &argv, "--log-basename=%s", get_dyn_LOGFILEBASE());
        }
        str_list_add_printf(&argv, "-F");
        if (argv == NULL) {
                goto nomem;
        }

        ret = posix_spawn(&pid, argv[0], NULL, NULL, argv, environ);
        if (ret == -1) {
                goto fail;
        }
        TALLOC_FREE(argv);

        close(ready_fds[1]);

        nread = sys_read(ready_fds[0], &pid, sizeof(pid));
        close(ready_fds[0]);
        if (nread != sizeof(pid)) {
                goto fail;
        }

        return pid;

nomem:
        errno = ENOMEM;
fail:
        {
                int err = errno;
                TALLOC_FREE(argv);
                errno = err;
        }

        return -1;
}


/* Run before the parent forks */
bool printing_subsystem_init(struct tevent_context *ev_ctx,
                             struct messaging_context *msg_ctx,
                             struct dcesrv_context *dce_ctx)
{
        pid_t pid = -1;

        pid = start_background_queue(NULL, NULL, NULL);
        if (pid == -1) {
                return false;
        }
        background_lpq_updater_pid = pid;

        if (!print_backend_init(msg_ctx)) {
                return false;
        }

        return true;
}

void send_to_bgqd(struct messaging_context *msg_ctx,
                  uint32_t msg_type,
                  const uint8_t *buf,
                  size_t buflen)
{
        pid_t bgqd = pidfile_pid(lp_pid_directory(), "samba-bgqd");

        if (bgqd == -1) {
                return;
        }
        messaging_send_buf(
                msg_ctx, pid_to_procid(bgqd), msg_type, buf, buflen);
}