src/lib-master/master-service.c

	master-service.c revision 9b0f6b90ff8d1d6efd718b0d7cbe01b2454e9fd6
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen/* Copyright (c) 2005-2015 Dovecot authors, see the included COPYING file */
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen#include "lib.h"
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen#include "lib-signals.h"
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen#include "ioloop.h"
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen#include "abspath.h"
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen#include "array.h"
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen#include "strescape.h"
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen#include "env-util.h"
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen#include "home-expand.h"
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen#include "process-title.h"
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen#include "restrict-access.h"
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen#include "fd-close-on-exec.h"
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen#include "settings-parser.h"
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen#include "syslog-util.h"
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen#include "master-instance.h"
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen#include "master-login.h"
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen#include "master-service-ssl.h"
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen#include "master-service-private.h"
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen#include "master-service-settings.h"
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen#include <stdlib.h>
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen#include <unistd.h>
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen#include <sys/stat.h>
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen#include <syslog.h>
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen#define DEFAULT_CONFIG_FILE_PATH SYSCONFDIR"/dovecot.conf"
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen/* getenv(MASTER_CONFIG_FILE_ENV) provides path to configuration file/socket */
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen#define MASTER_CONFIG_FILE_ENV "CONFIG_FILE"
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen/* getenv(MASTER_DOVECOT_VERSION_ENV) provides master's version number */
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen#define MASTER_DOVECOT_VERSION_ENV "DOVECOT_VERSION"
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen/* when we're full of connections, how often to check if login state has
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen   changed. we normally notice it immediately because of a signal, so this is
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen   just a fallback against race conditions. */
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen#define MASTER_SERVICE_STATE_CHECK_MSECS 1000
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen/* If die callback hasn't managed to stop the service for this many seconds,
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen   force it. */
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen#define MASTER_SERVICE_DIE_TIMEOUT_MSECS (30*1000)
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainenstruct master_service *master_service;
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainenstatic void master_service_io_listeners_close(struct master_service *service);
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainenstatic void master_service_refresh_login_state(struct master_service *service);
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainenconst char *master_service_getopt_string(void)
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen{
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen    return "c:i:ko:OL";
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen}
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainenstatic void sig_die(const siginfo_t *si, void *context)
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen{
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen    struct master_service *service = context;
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen    /* SIGINT comes either from master process or from keyboard. we don't
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen       want to log it in either case.*/
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen    if (si->si_signo != SIGINT) {
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen        i_warning("Killed with signal %d (by pid=%s uid=%s code=%s)",
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen              si->si_signo, dec2str(si->si_pid),
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen              dec2str(si->si_uid),
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen              lib_signal_code_to_str(si->si_signo, si->si_code));
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen    } else if ((service->flags & MASTER_SERVICE_FLAG_NO_IDLE_DIE) != 0) {
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen        /* never die when idling */
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen        return;
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen    } else if ((service->flags & MASTER_SERVICE_FLAG_STANDALONE) == 0) {
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen        /* SIGINT came from master. die only if we're not handling
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen           any clients currently. */
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen        if (service->master_status.available_count !=
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen            service->total_available_count)
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen            return;
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen        if (service->idle_die_callback != NULL &&
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen            !service->idle_die_callback())
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen            return;
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen    }
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen    service->killed = TRUE;
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen    io_loop_stop(service->ioloop);
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen}
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainenstatic void
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainensig_state_changed(const siginfo_t *si ATTR_UNUSED, void *context)
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen{
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen    struct master_service *service = context;
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen    master_service_refresh_login_state(service);
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen}
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainenstatic void master_service_verify_version_string(struct master_service *service)
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen{
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen    if (service->version_string != NULL &&
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen        strcmp(service->version_string, PACKAGE_VERSION) != 0) {
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen        i_fatal("Dovecot version mismatch: "
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen            "Master is v%s, %s is v"PACKAGE_VERSION" "
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen            "(if you don't care, set version_ignore=yes)",
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen            service->version_string, service->name);
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen    }
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen}
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainenstruct master_service *
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainenmaster_service_init(const char *name, enum master_service_flags flags,
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen            int *argc, char **argv[], const char *getopt_str)
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen{
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen    struct master_service *service;
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen    const char *value;
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen    unsigned int count;
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen    i_assert(name != NULL);
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen#ifdef DEBUG
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen    if (getenv("GDB") == NULL &&
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen        (flags & MASTER_SERVICE_FLAG_STANDALONE) == 0) {
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen        int count;
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen        value = getenv("SOCKET_COUNT");
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen        count = value == NULL ? 0 : atoi(value);
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen        fd_debug_verify_leaks(MASTER_LISTEN_FD_FIRST + count, 1024);
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen    }
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen#endif
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen    if ((flags & MASTER_SERVICE_FLAG_STANDALONE) == 0) {
ecc81625167ed96c04c02aa190a1ea5baa65b474Timo Sirainen        /* make sure we can dump core, at least until
           privileges are dropped. (i'm not really sure why this
           is needed, because doing the same just before exec
           doesn't help, and exec shouldn't affect this with
           non-setuid/gid binaries..) */
        restrict_access_allow_coredumps(TRUE);
    }

    /* NOTE: we start rooted, so keep the code minimal until
       restrict_access_by_env() is called */
    lib_init();
    /* Set a logging prefix temporarily. This will be ignored once the log
       is properly initialized */
    i_set_failure_prefix("%s(init): ", name);

    /* ignore these signals as early as possible */
    lib_signals_init();
        lib_signals_ignore(SIGPIPE, TRUE);
        lib_signals_ignore(SIGALRM, FALSE);

    if (getenv(MASTER_UID_ENV) == NULL)
        flags |= MASTER_SERVICE_FLAG_STANDALONE;

    process_title_init(argv);

    service = i_new(struct master_service, 1);
    service->argc = *argc;
    service->argv = *argv;
    service->name = i_strdup(name);
    /* keep getopt_str first in case it contains "+" */
    service->getopt_str = *getopt_str == '\0' ?
        i_strdup(master_service_getopt_string()) :
        i_strconcat(getopt_str, master_service_getopt_string(), NULL);
    service->flags = flags;
    service->ioloop = io_loop_create();
    service->service_count_left = UINT_MAX;
    service->config_fd = -1;

    service->config_path = i_strdup(getenv(MASTER_CONFIG_FILE_ENV));
    if (service->config_path == NULL)
        service->config_path = i_strdup(DEFAULT_CONFIG_FILE_PATH);
    else
        service->config_path_from_master = TRUE;

    if ((flags & MASTER_SERVICE_FLAG_STANDALONE) == 0) {
        service->version_string = getenv(MASTER_DOVECOT_VERSION_ENV);
        service->socket_count = 1;
    } else {
        service->version_string = PACKAGE_VERSION;
    }
    value = getenv("SOCKET_COUNT");
    if (value != NULL)
        service->socket_count = atoi(value);
    value = getenv("SSL_SOCKET_COUNT");
    if (value != NULL)
        service->ssl_socket_count = atoi(value);
    value = getenv("SOCKET_NAMES");
    if (value != NULL) {
        service->listener_names =
            p_strsplit_tabescaped(default_pool, value);
        service->listener_names_count =
            str_array_length((void *)service->listener_names);
    }
    service->want_ssl_settings = service->ssl_socket_count > 0 ||
        (flags & MASTER_SERVICE_FLAG_USE_SSL_SETTINGS) != 0;

    /* set up some kind of logging until we know exactly how and where
       we want to log */
    if (getenv("LOG_SERVICE") != NULL)
        i_set_failure_internal();
    if (getenv("USER") != NULL)
        i_set_failure_prefix("%s(%s): ", name, getenv("USER"));
    else
        i_set_failure_prefix("%s: ", name);

    if ((flags & MASTER_SERVICE_FLAG_STANDALONE) == 0) {
        /* initialize master_status structure */
        value = getenv(MASTER_UID_ENV);
        if (value == NULL ||
            str_to_uint(value, &service->master_status.uid) < 0)
            i_fatal(MASTER_UID_ENV" missing");
        service->master_status.pid = getpid();

        /* set the default limit */
        value = getenv(MASTER_CLIENT_LIMIT_ENV);
        if (value == NULL || str_to_uint(value, &count) < 0 ||
            count == 0)
            i_fatal(MASTER_CLIENT_LIMIT_ENV" missing");
        master_service_set_client_limit(service, count);

        /* seve the process limit */
        value = getenv(MASTER_PROCESS_LIMIT_ENV);
        if (value != NULL && str_to_uint(value, &count) == 0 &&
            count > 0)
            service->process_limit = count;

        value = getenv(MASTER_PROCESS_MIN_AVAIL_ENV);
        if (value != NULL && str_to_uint(value, &count) == 0 &&
            count > 0)
            service->process_min_avail = count;

        /* set the default service count */
        value = getenv(MASTER_SERVICE_COUNT_ENV);
        if (value != NULL && str_to_uint(value, &count) == 0 &&
            count > 0)
            master_service_set_service_count(service, count);

        /* set the idle kill timeout */
        value = getenv(MASTER_SERVICE_IDLE_KILL_ENV);
        if (value != NULL && str_to_uint(value, &count) == 0)
            service->idle_kill_secs = count;
    } else {
        master_service_set_client_limit(service, 1);
        master_service_set_service_count(service, 1);
    }
    if ((flags & MASTER_SERVICE_FLAG_KEEP_CONFIG_OPEN) != 0) {
        /* since we're going to keep the config socket open anyway,
           open it now so we can read settings even after privileges
           are dropped. */
        master_service_config_socket_try_open(service);
    }

    master_service_verify_version_string(service);
    return service;
}

int master_getopt(struct master_service *service)
{
    int c;

    i_assert(master_getopt_str_is_valid(service->getopt_str));

    while ((c = getopt(service->argc, service->argv,
               service->getopt_str)) > 0) {
        if (!master_service_parse_option(service, c, optarg))
            break;
    }
    return c;
}

bool master_getopt_str_is_valid(const char *str)
{
    unsigned int i, j;

    /* make sure there are no duplicates. there are few enough characters
       that this should be fast enough. */
    for (i = 0; str[i] != '\0'; i++) {
        if (str[i] == ':' || str[i] == '+' || str[i] == '-')
            continue;
        for (j = i+1; str[j] != '\0'; j++) {
            if (str[i] == str[j])
                return FALSE;
        }
    }
    return TRUE;
}

void master_service_init_log(struct master_service *service,
                 const char *prefix)
{
    const char *path, *timestamp;

    if ((service->flags & MASTER_SERVICE_FLAG_STANDALONE) != 0 &&
        (service->flags & MASTER_SERVICE_FLAG_DONT_LOG_TO_STDERR) == 0) {
        timestamp = getenv("LOG_STDERR_TIMESTAMP");
        if (timestamp != NULL)
            i_set_failure_timestamp_format(timestamp);
        i_set_failure_file("/dev/stderr", "");
        return;
    }

    if (getenv("LOG_SERVICE") != NULL && !service->log_directly) {
        /* logging via log service */
        i_set_failure_internal();
        i_set_failure_prefix("%s", prefix);
        return;
    }

    if (service->set == NULL) {
        i_set_failure_file("/dev/stderr", prefix);
        return;
    }

    if (strcmp(service->set->log_path, "syslog") != 0) {
        /* error logging goes to file or stderr */
        path = home_expand(service->set->log_path);
        i_set_failure_file(path, prefix);
    }

    if (strcmp(service->set->log_path, "syslog") == 0 ||
        strcmp(service->set->info_log_path, "syslog") == 0 ||
        strcmp(service->set->debug_log_path, "syslog") == 0) {
        /* something gets logged to syslog */
        int facility;

        if (!syslog_facility_find(service->set->syslog_facility,
                      &facility))
            facility = LOG_MAIL;
        i_set_failure_syslog("dovecot", LOG_NDELAY, facility);
        i_set_failure_prefix("%s", prefix);

        if (strcmp(service->set->log_path, "syslog") != 0) {
            /* set error handlers back to file */
            i_set_fatal_handler(default_fatal_handler);
            i_set_error_handler(default_error_handler);
        }
    }

    if (*service->set->info_log_path != '\0' &&
        strcmp(service->set->info_log_path, "syslog") != 0) {
        path = home_expand(service->set->info_log_path);
        if (*path != '\0')
            i_set_info_file(path);
    }

    if (*service->set->debug_log_path != '\0' &&
        strcmp(service->set->debug_log_path, "syslog") != 0) {
        path = home_expand(service->set->debug_log_path);
        if (*path != '\0')
            i_set_debug_file(path);
    }
    i_set_failure_timestamp_format(service->set->log_timestamp);
}

void master_service_set_die_with_master(struct master_service *service,
                    bool set)
{
    service->die_with_master = set;
}

void master_service_set_die_callback(struct master_service *service,
                     void (*callback)(void))
{
    service->die_callback = callback;
}

void master_service_set_idle_die_callback(struct master_service *service,
                      bool (*callback)(void))
{
    service->idle_die_callback = callback;
}

static bool get_instance_config(const char *name, const char **config_path_r)
{
    struct master_instance_list *list;
    const struct master_instance *inst;
    const char *instance_path, *path;

    /* note that we don't have any settings yet. we're just finding out
       which dovecot.conf we even want to read! so we must use the
       hardcoded state_dir path. */
    instance_path = t_strconcat(PKG_STATEDIR"/"MASTER_INSTANCE_FNAME, NULL);
    list = master_instance_list_init(instance_path);
    inst = master_instance_list_find_by_name(list, name);
    if (inst != NULL) {
        path = t_strdup_printf("%s/dovecot.conf", inst->base_dir);
        if (t_readlink(path, config_path_r) < 0)
            i_fatal("readlink(%s) failed: %m", path);
    }
    master_instance_list_deinit(&list);
    return inst != NULL;
}

bool master_service_parse_option(struct master_service *service,
                 int opt, const char *arg)
{
    const char *path;

    switch (opt) {
    case 'c':
        service->config_path = i_strdup(arg);
        service->config_path_changed_with_param = TRUE;
        break;
    case 'i':
        if (!get_instance_config(arg, &path))
            i_fatal("Unknown instance name: %s", arg);
        service->config_path = i_strdup(path);
        service->config_path_changed_with_param = TRUE;
        break;
    case 'k':
        service->keep_environment = TRUE;
        break;
    case 'o':
        if (!array_is_created(&service->config_overrides))
            i_array_init(&service->config_overrides, 16);
        array_append(&service->config_overrides, &arg, 1);
        break;
    case 'O':
        service->flags |= MASTER_SERVICE_FLAG_NO_CONFIG_SETTINGS;
        break;
    case 'L':
        service->log_directly = TRUE;
        break;
    default:
        return FALSE;
    }
    return TRUE;
}

static void master_service_error(struct master_service *service)
{
    master_service_stop_new_connections(service);
    if (service->master_status.available_count ==
        service->total_available_count || service->die_with_master) {
        if (service->die_callback == NULL)
            master_service_stop(service);
        else {
            service->to_die =
                timeout_add(MASTER_SERVICE_DIE_TIMEOUT_MSECS,
                        master_service_stop,
                        service);
            service->die_callback();
        }
    }
}

static void master_status_error(struct master_service *service)
{
    /* status fd is a write-only pipe, so if we're here it means the
       master wants us to die (or died itself). don't die until all
       service connections are finished. */
    io_remove(&service->io_status_error);

    /* the log fd may also be closed already, don't die when trying to
       log later */
    i_set_failure_ignore_errors(TRUE);

    master_service_error(service);
}

void master_service_init_finish(struct master_service *service)
{
    enum libsig_flags sigint_flags = LIBSIG_FLAG_DELAYED;
    struct stat st;

    /* set default signal handlers */
    if ((service->flags & MASTER_SERVICE_FLAG_STANDALONE) == 0)
        sigint_flags |= LIBSIG_FLAG_RESTART;
        lib_signals_set_handler(SIGINT, sigint_flags, sig_die, service);
    lib_signals_set_handler(SIGTERM, LIBSIG_FLAG_DELAYED, sig_die, service);
    if ((service->flags & MASTER_SERVICE_FLAG_TRACK_LOGIN_STATE) != 0) {
        lib_signals_set_handler(SIGUSR1, LIBSIG_FLAGS_SAFE,
                    sig_state_changed, service);
    }

    if ((service->flags & MASTER_SERVICE_FLAG_STANDALONE) == 0) {
        if (fstat(MASTER_STATUS_FD, &st) < 0 || !S_ISFIFO(st.st_mode))
            i_fatal("Must be started by dovecot master process");

        /* start listening errors for status fd, it means master died */
        service->io_status_error = io_add(MASTER_DEAD_FD, IO_ERROR,
                          master_status_error, service);
    }
    master_service_io_listeners_add(service);
    if (service->want_ssl_settings &&
        (service->flags & MASTER_SERVICE_FLAG_NO_SSL_INIT) == 0)
        master_service_ssl_ctx_init(service);

    if ((service->flags & MASTER_SERVICE_FLAG_STD_CLIENT) != 0) {
        /* we already have a connection to be served */
        service->master_status.available_count--;
    }
    master_status_update(service);
}

void master_service_env_clean(void)
{
    const char *value = getenv(DOVECOT_PRESERVE_ENVS_ENV);

    if (value == NULL || *value == '\0')
        env_clean();
    else T_BEGIN {
        value = t_strconcat(value, " "DOVECOT_PRESERVE_ENVS_ENV, NULL);
        env_clean_except(t_strsplit_spaces(value, " "));
    } T_END;
}

void master_service_set_client_limit(struct master_service *service,
                     unsigned int client_limit)
{
    unsigned int used;

    i_assert(service->master_status.available_count ==
         service->total_available_count);

    used = service->total_available_count -
        service->master_status.available_count;
    i_assert(client_limit >= used);

    service->total_available_count = client_limit;
    service->master_status.available_count = client_limit - used;
}

unsigned int master_service_get_client_limit(struct master_service *service)
{
    return service->total_available_count;
}

unsigned int master_service_get_process_limit(struct master_service *service)
{
    return service->process_limit;
}

unsigned int master_service_get_process_min_avail(struct master_service *service)
{
    return service->process_min_avail;
}

unsigned int master_service_get_idle_kill_secs(struct master_service *service)
{
    return service->idle_kill_secs;
}

void master_service_set_service_count(struct master_service *service,
                      unsigned int count)
{
    unsigned int used;

    used = service->total_available_count -
        service->master_status.available_count;
    i_assert(count >= used);

    if (service->total_available_count > count) {
        service->total_available_count = count;
        service->master_status.available_count = count - used;
    }
    service->service_count_left = count;
}

unsigned int master_service_get_service_count(struct master_service *service)
{
    return service->service_count_left;
}

unsigned int master_service_get_socket_count(struct master_service *service)
{
    return service->socket_count;
}

const char *master_service_get_socket_name(struct master_service *service,
                       int listen_fd)
{
    unsigned int i;

    i_assert(listen_fd >= MASTER_LISTEN_FD_FIRST);

    i = listen_fd - MASTER_LISTEN_FD_FIRST;
    return i < service->listener_names_count ?
        service->listener_names[i] : "";
}

void master_service_set_avail_overflow_callback(struct master_service *service,
                        void (*callback)(void))
{
    service->avail_overflow_callback = callback;
}

const char *master_service_get_config_path(struct master_service *service)
{
    return service->config_path;
}

const char *master_service_get_version_string(struct master_service *service)
{
    return service->version_string;
}

const char *master_service_get_name(struct master_service *service)
{
    return service->name;
}

void master_service_run(struct master_service *service,
            master_service_connection_callback_t *callback)
{
    service->callback = callback;
    io_loop_run(service->ioloop);
    service->callback = NULL;
}

void master_service_stop(struct master_service *service)
{
        io_loop_stop(service->ioloop);
}

void master_service_stop_new_connections(struct master_service *service)
{
    unsigned int current_count;

    if (service->stopping)
        return;

    service->stopping = TRUE;
    master_service_io_listeners_remove(service);
    master_service_io_listeners_close(service);

    /* make sure we stop after servicing current connections */
    current_count = service->total_available_count -
        service->master_status.available_count;
    service->service_count_left = current_count;
    service->total_available_count = current_count;

    if (current_count == 0)
        master_service_stop(service);
    else {
        /* notify master that we're not accepting any more
           connections */
        service->master_status.available_count = 0;
        master_status_update(service);
    }
    if (service->login != NULL)
        master_login_stop(service->login);
}

bool master_service_is_killed(struct master_service *service)
{
    return service->killed;
}

bool master_service_is_master_stopped(struct master_service *service)
{
    return service->io_status_error == NULL;
}

void master_service_anvil_send(struct master_service *service, const char *cmd)
{
    ssize_t ret;

    if ((service->flags & MASTER_SERVICE_FLAG_STANDALONE) != 0)
        return;

    ret = write(MASTER_ANVIL_FD, cmd, strlen(cmd));
    if (ret < 0) {
        if (errno == EPIPE) {
            /* anvil process was probably recreated, don't bother
               logging an error about losing connection to it */
            return;
        }
        i_error("write(anvil) failed: %m");
    } else if (ret == 0)
        i_error("write(anvil) failed: EOF");
    else {
        i_assert((size_t)ret == strlen(cmd));
    }
}

void master_service_client_connection_created(struct master_service *service)
{
    i_assert(service->master_status.available_count > 0);
    service->master_status.available_count--;
    master_status_update(service);
}

void master_service_client_connection_accept(struct master_service_connection *conn)
{
    conn->accepted = TRUE;
}

void master_service_client_connection_destroyed(struct master_service *service)
{
    /* we can listen again */
    master_service_io_listeners_add(service);

    i_assert(service->total_available_count > 0);
    i_assert(service->service_count_left > 0);

    if (service->service_count_left == service->total_available_count) {
        service->total_available_count--;
                service->service_count_left--;
    } else {
        if (service->service_count_left != UINT_MAX)
            service->service_count_left--;

        i_assert(service->master_status.available_count <
             service->total_available_count);
        service->master_status.available_count++;
    }

    if (service->service_count_left == 0) {
        i_assert(service->master_status.available_count ==
             service->total_available_count);
        master_service_stop(service);
    } else if ((service->io_status_error == NULL ||
            service->listeners == NULL) &&
           service->master_status.available_count ==
           service->total_available_count) {
        /* we've finished handling all clients, and
           a) master has closed the connection
           b) there are no listeners (std-client?) */
        master_service_stop(service);
    } else {
        master_status_update(service);
    }
}

static void master_service_set_login_state(struct master_service *service,
                       enum master_login_state state)
{
    if (service->to_overflow_state != NULL)
        timeout_remove(&service->to_overflow_state);

    switch (state) {
    case MASTER_LOGIN_STATE_NONFULL:
        service->call_avail_overflow = FALSE;
        if (service->master_status.available_count > 0)
            return;

        /* some processes should now be able to handle new connections,
           although we can't. but there may be race conditions, so
           make sure that we'll check again soon if the state has
           changed to "full" without our knowledge. */
        service->to_overflow_state =
            timeout_add(MASTER_SERVICE_STATE_CHECK_MSECS,
                    master_service_refresh_login_state,
                    service);
        return;
    case MASTER_LOGIN_STATE_FULL:
        /* make sure we're listening for more connections */
        service->call_avail_overflow = TRUE;
        master_service_io_listeners_add(service);
        return;
    }
    i_error("Invalid master login state: %d", state);
}

static void master_service_refresh_login_state(struct master_service *service)
{
    int ret;

    ret = lseek(MASTER_LOGIN_NOTIFY_FD, 0, SEEK_CUR);
    if (ret < 0)
        i_error("lseek(login notify fd) failed: %m");
    else
        master_service_set_login_state(service, ret);
}

void master_service_close_config_fd(struct master_service *service)
{
    if (service->config_fd != -1) {
        if (close(service->config_fd) < 0)
            i_error("close(master config fd) failed: %m");
        service->config_fd = -1;
    }
}

void master_service_deinit(struct master_service **_service)
{
    struct master_service *service = *_service;

    *_service = NULL;

    master_service_io_listeners_remove(service);
    master_service_ssl_ctx_deinit(service);

    master_service_close_config_fd(service);
    if (service->to_die != NULL)
        timeout_remove(&service->to_die);
    if (service->to_overflow_state != NULL)
        timeout_remove(&service->to_overflow_state);
    if (service->to_status != NULL)
        timeout_remove(&service->to_status);
    if (service->io_status_error != NULL)
        io_remove(&service->io_status_error);
    if (service->io_status_write != NULL)
        io_remove(&service->io_status_write);
    if (array_is_created(&service->config_overrides))
        array_free(&service->config_overrides);

    if (service->set_parser != NULL) {
        settings_parser_deinit(&service->set_parser);
        pool_unref(&service->set_pool);
    }
    lib_signals_deinit();
    /* run atexit callbacks before destroying ioloop */
    lib_atexit_run();
    io_loop_destroy(&service->ioloop);

    if (service->listener_names != NULL)
        p_strsplit_free(default_pool, service->listener_names);
    i_free(service->listeners);
    i_free(service->getopt_str);
    i_free(service->name);
    i_free(service->config_path);
    i_free(service);

    lib_deinit();
}

static void master_service_listen(struct master_service_listener *l)
{
    struct master_service *service = l->service;
    struct master_service_connection conn;

    if (service->master_status.available_count == 0) {
        /* we are full. stop listening for now, unless overflow
           callback destroys one of the existing connections */
        if (service->call_avail_overflow &&
            service->avail_overflow_callback != NULL)
            service->avail_overflow_callback();

        if (service->master_status.available_count == 0) {
            master_service_io_listeners_remove(service);
            return;
        }
    }

    memset(&conn, 0, sizeof(conn));
    conn.listen_fd = l->fd;
    conn.fd = net_accept(l->fd, &conn.remote_ip, &conn.remote_port);
    if (conn.fd < 0) {
        struct stat st;
        int orig_errno = errno;

        if (conn.fd == -1)
            return;

        if (errno == ENOTSOCK) {
            /* it's not a socket. should be a fifo. */
        } else if (errno == EINVAL &&
               (fstat(l->fd, &st) == 0 && S_ISFIFO(st.st_mode))) {
            /* BSDI fails accept(fifo) with EINVAL. */
        } else {
            errno = orig_errno;
            i_error("net_accept() failed: %m");
            /* try again later after one of the existing
               connections has died */
            master_service_io_listeners_remove(service);
            return;
        }
        /* use the "listener" as the connection fd and stop the
           listener. */
        conn.fd = l->fd;
        conn.listen_fd = l->fd;
        conn.fifo = TRUE;

        io_remove(&l->io);
        l->fd = -1;
    }
    conn.ssl = l->ssl;
    conn.name = l->name;
    net_set_nonblock(conn.fd, TRUE);

    master_service_client_connection_created(service);

    service->callback(&conn);

    if (!conn.accepted) {
        if (close(conn.fd) < 0)
            i_error("close(service connection) failed: %m");
        master_service_client_connection_destroyed(service);
    } else if (conn.fifo) {
        /* reading FIFOs stays open forever, don't count them
           as real clients */
        master_service_client_connection_destroyed(service);
    }
    if (service->master_status.available_count == 0 &&
        service->service_count_left == 1) {
        /* we're not going to accept any more connections after this.
           go ahead and close the connection early. don't do this
           before calling callback, because it may want to access
           the listen_fd (e.g. to check socket permissions). */
        i_assert(service->listeners != NULL);
        master_service_io_listeners_remove(service);
        master_service_io_listeners_close(service);
    }
}

static void io_listeners_init(struct master_service *service)
{
    unsigned int i;

    if (service->socket_count == 0)
        return;

    service->listeners =
        i_new(struct master_service_listener, service->socket_count);

    for (i = 0; i < service->socket_count; i++) {
        struct master_service_listener *l = &service->listeners[i];

        l->service = service;
        l->fd = MASTER_LISTEN_FD_FIRST + i;
        l->name = i < service->listener_names_count ?
            service->listener_names[i] : "";

        if (i >= service->socket_count - service->ssl_socket_count)
            l->ssl = TRUE;
    }
}

void master_service_io_listeners_add(struct master_service *service)
{
    unsigned int i;

    if (service->stopping)
        return;

    if (service->listeners == NULL)
        io_listeners_init(service);

    for (i = 0; i < service->socket_count; i++) {
        struct master_service_listener *l = &service->listeners[i];

        if (l->io == NULL && l->fd != -1) {
            l->io = io_add(MASTER_LISTEN_FD_FIRST + i, IO_READ,
                       master_service_listen, l);
        }
    }
}

void master_service_io_listeners_remove(struct master_service *service)
{
    unsigned int i;

    if (service->listeners != NULL) {
        for (i = 0; i < service->socket_count; i++) {
            if (service->listeners[i].io != NULL)
                io_remove(&service->listeners[i].io);
        }
    }
}

void master_service_ssl_io_listeners_remove(struct master_service *service)
{
    unsigned int i;

    if (service->listeners != NULL) {
        for (i = 0; i < service->socket_count; i++) {
            if (service->listeners[i].io != NULL &&
                service->listeners[i].ssl)
                io_remove(&service->listeners[i].io);
        }
    }
}

static void master_service_io_listeners_close(struct master_service *service)
{
    unsigned int i;

    if (service->listeners != NULL) {
        /* close via listeners. some fds might be pipes that are
           currently handled as clients. we don't want to close them. */
        for (i = 0; i < service->socket_count; i++) {
            if (service->listeners[i].fd != -1) {
                if (close(service->listeners[i].fd) < 0) {
                    i_error("close(listener %d) failed: %m",
                        service->listeners[i].fd);
                }
                service->listeners[i].fd = -1;
            }
        }
    } else {
        for (i = 0; i < service->socket_count; i++) {
            int fd = MASTER_LISTEN_FD_FIRST + i;

            if (close(fd) < 0)
                i_error("close(listener %d) failed: %m", fd);
        }
    }
}

static bool master_status_update_is_important(struct master_service *service)
{
    if (service->master_status.available_count == 0)
        return TRUE;
    if (!service->initial_status_sent)
        return TRUE;
    return FALSE;
}

void master_status_update(struct master_service *service)
{
    ssize_t ret;
    bool important_update;

    if ((service->flags & MASTER_SERVICE_FLAG_UPDATE_PROCTITLE) != 0 &&
        service->set != NULL && service->set->verbose_proctitle) T_BEGIN {
        unsigned int used_count = service->total_available_count -
            service->master_status.available_count;

        process_title_set(t_strdup_printf("[%u connections]",
                          used_count));
    } T_END;

    important_update = master_status_update_is_important(service);
    if (service->master_status.pid == 0 ||
        service->master_status.available_count ==
        service->last_sent_status_avail_count) {
        /* a) closed, b) updating to same state */
        if (service->to_status != NULL)
            timeout_remove(&service->to_status);
        if (service->io_status_write != NULL)
            io_remove(&service->io_status_write);
        return;
    }
    if (ioloop_time == service->last_sent_status_time &&
        !important_update) {
        /* don't spam master */
        if (service->to_status != NULL)
            timeout_reset(service->to_status);
        else {
            service->to_status =
                timeout_add(1000, master_status_update,
                        service);
        }
        if (service->io_status_write != NULL)
            io_remove(&service->io_status_write);
        return;
    }

    if (service->to_status != NULL)
        timeout_remove(&service->to_status);

    ret = write(MASTER_STATUS_FD, &service->master_status,
            sizeof(service->master_status));
    if (ret == sizeof(service->master_status)) {
        /* success */
        if (service->io_status_write != NULL) {
            /* delayed important update sent successfully */
            io_remove(&service->io_status_write);
        }
        service->last_sent_status_time = ioloop_time;
        service->last_sent_status_avail_count =
            service->master_status.available_count;
        service->initial_status_sent = TRUE;
    } else if (ret >= 0) {
        /* shouldn't happen? */
        i_error("write(master_status_fd) returned %d", (int)ret);
        service->master_status.pid = 0;
    } else if (errno != EAGAIN) {
        /* failure */
        if (errno != EPIPE)
            i_error("write(master_status_fd) failed: %m");
        service->master_status.pid = 0;
    } else if (important_update) {
        /* reader is busy, but it's important to get this notification
           through. send it when possible. */
        if (service->io_status_write == NULL) {
            service->io_status_write =
                io_add(MASTER_STATUS_FD, IO_WRITE,
                       master_status_update, service);
        }
    }
}

bool version_string_verify(const char *line, const char *service_name,
               unsigned major_version)
{
    unsigned int minor_version;

    return version_string_verify_full(line, service_name,
                      major_version, &minor_version);
}

bool version_string_verify_full(const char *line, const char *service_name,
                unsigned major_version,
                unsigned int *minor_version_r)
{
    unsigned int service_name_len = strlen(service_name);
    bool ret;

    if (strncmp(line, "VERSION\t", 8) != 0)
        return FALSE;
    line += 8;

    if (strncmp(line, service_name, service_name_len) != 0 ||
        line[service_name_len] != '\t')
        return FALSE;
    line += service_name_len + 1;

    T_BEGIN {
        const char *p = strchr(line, '\t');

        if (p == NULL)
            ret = FALSE;
        else {
            ret = str_uint_equals(t_strdup_until(line, p),
                          major_version);
            if (str_to_uint(p+1, minor_version_r) < 0)
                ret = FALSE;
        }
    } T_END;
    return ret;
}