src/master/main.c

	main.c revision 00c032607ddc0603e40ff5cc2e03373df904a4a2
/* Copyright (C) 2002 Timo Sirainen */

#include "common.h"
#include "ioloop.h"
#include "lib-signals.h"
#include "network.h"
#include "env-util.h"
#include "fd-close-on-exec.h"
#include "write-full.h"

#include "auth-process.h"
#include "login-process.h"
#include "mail-process.h"
#include "ssl-init.h"
#include "log.h"

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <syslog.h>
#include <sys/stat.h>
#include <sys/wait.h>

const char *process_names[PROCESS_TYPE_MAX] = {
    "unknown",
    "auth",
    "login",
    "imap",
    "pop3",
    "ssl-param"
};

static const char *configfile = SYSCONFDIR "/" PACKAGE ".conf";
static struct timeout *to;
static unsigned int settings_reload_hup_count = 0;

struct ioloop *ioloop;
struct hash_table *pids;
int null_fd, inetd_login_fd;
uid_t master_uid;
#ifdef DEBUG
static int gdb;
#endif

static void listen_fds_open(int retry);
static void listen_fds_close(struct server_settings *server);

int validate_str(const char *str, size_t max_len)
{
    size_t i;

    for (i = 0; i < max_len; i++) {
        if (str[i] == '\0')
            return TRUE;
    }

    return FALSE;
}

void child_process_init_env(void)
{
    /* remove all environment, we don't need them */
    env_clean();

    /* we'll log through master process */
    env_put("LOG_TO_MASTER=1");

#ifdef DEBUG
    if (gdb) env_put("GDB=1");
#endif
}

static void sig_quit(int signo __attr_unused__)
{
    io_loop_stop(ioloop);
}

static void set_logfile(struct settings *set)
{
    if (set->log_path == NULL)
        i_set_failure_syslog("dovecot", LOG_NDELAY, LOG_MAIL);
    else {
        /* log to file or stderr */
        i_set_failure_file(set->log_path, "dovecot");
    }

    if (set->info_log_path != NULL)
        i_set_info_file(set->info_log_path);

    i_set_failure_timestamp_format(set->log_timestamp);
}

static void settings_reload(void)
{
    struct server_settings *old_set = settings_root;

    i_warning("SIGHUP received - reloading configuration");

    /* restart auth and login processes */
        login_processes_destroy_all();
        auth_processes_destroy_all();

    if (!master_settings_read(configfile, FALSE))
        i_warning("Invalid configuration, keeping old one");
    else {
        listen_fds_close(old_set);
        listen_fds_open(TRUE);
                set_logfile(settings_root->defaults);
    }
}

static const char *get_exit_status_message(enum fatal_exit_status status)
{
    switch (status) {
    case FATAL_LOGOPEN:
        return "Can't open log file";
    case FATAL_LOGWRITE:
        return "Can't write to log file";
    case FATAL_LOGERROR:
        return "Internal logging error";
    case FATAL_OUTOFMEM:
        return "Out of memory";
    case FATAL_EXEC:
        return "exec() failed";

    case FATAL_DEFAULT:
        return NULL;
    }

    return NULL;
}

static void timeout_handler(void *context __attr_unused__)
{
    const char *process_type_name, *msg;
    pid_t pid;
    int status, process_type;

    if (lib_signal_hup_count != settings_reload_hup_count) {
        settings_reload_hup_count = lib_signal_hup_count;
        settings_reload();
    }

    while ((pid = waitpid(-1, &status, WNOHANG)) > 0) {
        /* get the type and remove from hash */
        process_type = PID_GET_PROCESS_TYPE(pid);
        PID_REMOVE_PROCESS_TYPE(pid);

        if (process_type == PROCESS_TYPE_IMAP ||
            process_type == PROCESS_TYPE_POP3)
            mail_process_destroyed(pid);
        if (process_type == PROCESS_TYPE_SSL_PARAM)
            ssl_parameter_process_destroyed(pid);

        /* write errors to syslog */
        process_type_name = process_names[process_type];
        if (WIFEXITED(status)) {
            status = WEXITSTATUS(status);
            if (status != 0) {
                if (process_type == PROCESS_TYPE_LOGIN)
                    login_process_abormal_exit(pid);

                msg = get_exit_status_message(status);
                msg = msg == NULL ? "" :
                    t_strconcat(" (", msg, ")", NULL);
                i_error("child %s (%s) returned error %d%s",
                    dec2str(pid), process_type_name,
                    status, msg);
            }
        } else if (WIFSIGNALED(status)) {
            if (process_type == PROCESS_TYPE_LOGIN)
                login_process_abormal_exit(pid);
            i_error("child %s (%s) killed with signal %d",
                dec2str(pid), process_type_name,
                WTERMSIG(status));
        }
    }

    if (pid == -1 && errno != EINTR && errno != ECHILD)
        i_warning("waitpid() failed: %m");
}

static struct ip_addr *resolve_ip(const char *name, unsigned int *port)
{
    const char *p;
    struct ip_addr *ip;
    int ret, ips_count;

    if (name == NULL)
        return NULL; /* defaults to "*" or "[::]" */

    if (name[0] == '[') {
        /* IPv6 address */
        p = strchr(name, ']');
        if (p == NULL)
            i_fatal("Missing ']' in address %s", name);

        name = t_strdup_until(name+1, p);

        p++;
        if (*p == '\0')
            p = NULL;
        else if (*p != ':')
            i_fatal("Invalid data after ']' in address %s", name);
    } else {
        p = strrchr(name, ':');
        if (p != NULL)
            name = t_strdup_until(name, p);
    }

    if (p != NULL) {
        if (!is_numeric(p+1, '\0'))
            i_fatal("Invalid port in address %s", name);
        *port = atoi(p+1);
    }

    if (strcmp(name, "*") == 0) {
        /* IPv4 any */
        ip = t_new(struct ip_addr, 1);
        net_get_ip_any4(ip);
        return ip;
    }

    if (strcmp(name, "::") == 0) {
        /* IPv6 any */
        ip = t_new(struct ip_addr, 1);
        net_get_ip_any6(ip);
        return ip;
    }

    /* Return the first IP if there happens to be multiple. */
    ret = net_gethostbyname(name, &ip, &ips_count);
    if (ret != 0) {
        i_fatal("Can't resolve address %s: %s",
            name, net_gethosterror(ret));
    }

    if (ips_count < 1)
        i_fatal("No IPs for address: %s", name);

    return ip;
}

static void listen_protocols(struct settings *set, int retry)
{
    struct ip_addr *normal_ip, *ssl_ip, *ip;
    const char *const *proto;
    unsigned int normal_port, ssl_port, port;
    int *fd, i;

    normal_port = set->protocol == MAIL_PROTOCOL_IMAP ? 143 : 110;
#ifdef HAVE_SSL
    ssl_port = set->protocol == MAIL_PROTOCOL_IMAP ? 993 : 995;
#else
    ssl_port = 0;
#endif

    /* resolve */
    normal_ip = resolve_ip(set->listen, &normal_port);
    ssl_ip = resolve_ip(set->ssl_listen, &ssl_port);

    if (ssl_ip == NULL && set->ssl_listen == NULL)
        ssl_ip = normal_ip;

    /* register wanted protocols */
        proto = t_strsplit_spaces(set->protocols, " ");
    for (; *proto != NULL; proto++) {
        fd = NULL; ip = NULL; port = 0;
        if (strcasecmp(*proto, "imap") == 0) {
            if (set->protocol == MAIL_PROTOCOL_IMAP) {
                fd = &set->listen_fd;
                port = normal_port; ip = normal_ip;
            }
        } else if (strcasecmp(*proto, "imaps") == 0) {
            if (set->protocol == MAIL_PROTOCOL_IMAP &&
                !set->ssl_disable) {
                fd = &set->ssl_listen_fd;
                port = ssl_port; ip = ssl_ip;
            }
        } else if (strcasecmp(*proto, "pop3") == 0) {
            if (set->protocol == MAIL_PROTOCOL_POP3) {
                fd = &set->listen_fd;
                port = normal_port; ip = normal_ip;
            }
        } else if (strcasecmp(*proto, "pop3s") == 0) {
            if (set->protocol == MAIL_PROTOCOL_POP3 &&
                !set->ssl_disable) {
                fd = &set->ssl_listen_fd;
                port = ssl_port; ip = ssl_ip;
            }
        } else {
            i_fatal("Unknown protocol %s", *proto);
        }

        if (fd == NULL)
            continue;

        if (*fd != -1)
            i_fatal("Protocol %s given more than once", *proto);

        if (port == 0)
            *fd = null_fd;
        else {
            for (i = 0; i < 10; i++) {
                *fd = net_listen(ip, &port);
                if (*fd != -1 || errno != EADDRINUSE || !retry)
                    break;

                /* wait a while and try again. we're SIGHUPing
                   so we most likely just closed it ourself.. */
                sleep(1);
            }

            if (*fd == -1)
                i_fatal("listen(%d) failed: %m", port);
            net_set_nonblock(*fd, TRUE);
        }
        fd_close_on_exec(*fd, TRUE);
    }

    if (set->listen_fd == -1)
        set->listen_fd = null_fd;
    if (set->ssl_listen_fd == -1)
        set->ssl_listen_fd = null_fd;
}

static void listen_fds_open(int retry)
{
    struct server_settings *server;

    for (server = settings_root; server != NULL; server = server->next) {
        if (server->imap != NULL)
            listen_protocols(server->imap, retry);
        if (server->pop3 != NULL)
            listen_protocols(server->pop3, retry);
    }
}

static void listen_fds_close(struct server_settings *server)
{
    for (; server != NULL; server = server->next) {
        if (server->imap != NULL) {
            if (server->imap->listen_fd != null_fd &&
                close(server->imap->listen_fd) < 0)
                i_error("close(imap.listen_fd) failed: %m");
            if (server->imap->ssl_listen_fd != null_fd &&
                close(server->imap->ssl_listen_fd) < 0)
                i_error("close(imap.ssl_listen_fd) failed: %m");
        }
        if (server->pop3 != NULL) {
            if (server->pop3->listen_fd != null_fd &&
                close(server->pop3->listen_fd) < 0)
                i_error("close(pop3.listen_fd) failed: %m");
            if (server->pop3->ssl_listen_fd != null_fd &&
                close(server->pop3->ssl_listen_fd) < 0)
                i_error("close(pop3.ssl_listen_fd) failed: %m");
        }
    }
}

static int have_stderr_set(struct settings *set)
{
    if (set->log_path != NULL &&
        strcmp(set->log_path, "/dev/stderr") == 0)
        return TRUE;

    if (set->info_log_path != NULL &&
        strcmp(set->info_log_path, "/dev/stderr") == 0)
        return TRUE;

    return FALSE;
}

static int have_stderr(struct server_settings *server)
{
    while (server != NULL) {
        if (server->imap != NULL && have_stderr_set(server->imap))
            return TRUE;
        if (server->pop3 != NULL && have_stderr_set(server->pop3))
            return TRUE;

        server = server->next;
    }

    return FALSE;
}

static void open_fds(void)
{
    /* initialize fds. */
    null_fd = open("/dev/null", O_RDONLY);
    if (null_fd == -1)
        i_fatal("Can't open /dev/null: %m");
    fd_close_on_exec(null_fd, TRUE);

    /* make sure all fds between 0..3 are used. */
    while (null_fd < 4) {
        null_fd = dup(null_fd);
        fd_close_on_exec(null_fd, TRUE);
    }

    if (!IS_INETD())
        listen_fds_open(FALSE);

    /* close stdin and stdout. close stderr unless we're logging
       into /dev/stderr. */
    if (dup2(null_fd, 0) < 0)
        i_fatal("dup2(0) failed: %m");
    if (dup2(null_fd, 1) < 0)
        i_fatal("dup2(1) failed: %m");

    if (!have_stderr(settings_root)) {
        if (dup2(null_fd, 2) < 0)
            i_fatal("dup2(2) failed: %m");
    }
}

static void create_pid_file(const char *path)
{
    const char *pid;
    int fd;

    pid = t_strconcat(dec2str(getpid()), "\n", NULL);

    fd = open(path, O_WRONLY|O_CREAT|O_TRUNC, 0644);
    if (fd == -1)
        i_fatal("open(%s) failed: %m", path);
    if (write_full(fd, pid, strlen(pid)) < 0)
        i_fatal("write() failed in %s: %m", path);
    (void)close(fd);
}

static void main_init(void)
{
    /* deny file access from everyone else except owner */
        (void)umask(0077);

    set_logfile(settings_root->defaults);
    i_info("Dovecot v"VERSION" starting up");

    log_init();

    lib_init_signals(sig_quit);

    pids = hash_create(default_pool, default_pool, 128, NULL, NULL);
    to = timeout_add(100, timeout_handler, NULL);

    ssl_init();
    auth_processes_init();
    login_processes_init();

    create_pid_file(t_strconcat(settings_root->defaults->base_dir,
                    "/master.pid", NULL));
}

static void main_deinit(void)
{
        if (lib_signal_kill != 0)
        i_warning("Killed with signal %d", lib_signal_kill);

    (void)unlink(t_strconcat(settings_root->defaults->base_dir,
                 "/master.pid", NULL));

    /* make sure we log if child processes died unexpectedly */
    timeout_handler(NULL);

    login_processes_deinit();
    auth_processes_deinit();
    ssl_deinit();

    timeout_remove(to);

    if (close(null_fd) < 0)
        i_error("close(null_fd) failed: %m");

    hash_destroy(pids);
    log_deinit();
    closelog();
}

static void daemonize(struct settings *set)
{
    pid_t pid;

    pid = fork();
    if (pid < 0)
        i_fatal("fork() failed: %m");

    if (pid != 0)
        _exit(0);

    if (setsid() < 0)
        i_fatal("setsid() failed: %m");

    if (chdir(set->base_dir) < 0)
        i_fatal("chdir(%s) failed: %m", set->base_dir);
}

static void print_help(void)
{
    printf("Usage: dovecot [-F] [-c <config file>]\n");
}

int main(int argc, char *argv[])
{
    /* parse arguments */
    const char *exec_protocol = NULL, *exec_section = NULL;
    int foreground = FALSE;
    int i;

#ifdef DEBUG
    gdb = getenv("GDB") != NULL;
#endif
    lib_init();

    master_uid = geteuid();
        inetd_login_fd = -1;
    for (i = 1; i < argc; i++) {
        if (strcmp(argv[i], "-F") == 0) {
            /* foreground */
            foreground = TRUE;
        } else if (strcmp(argv[i], "-c") == 0) {
            /* config file */
            i++;
            if (i == argc) i_fatal("Missing config file argument");
            configfile = argv[i];
        } else if (strcmp(argv[i], "--exec-mail") == 0) {
            /* <protocol> [<server section>]
               read configuration and execute mail process */
            i++;
            if (i == argc) i_fatal("Missing protocol argument");
            exec_protocol = argv[i];
            if (i+1 != argc)
                exec_section = argv[++i];
        } else if (strcmp(argv[i], "--version") == 0) {
            printf("%s\n", VERSION);
            return 0;
        } else {
            print_help();
            i_fatal("Unknown argument: %s", argv[1]);
        }
    }

    if (getenv("DOVECOT_INETD") != NULL) {
        /* starting through inetd. */
        inetd_login_fd = dup(0);
        if (inetd_login_fd == -1)
            i_fatal("dup(0) failed: %m");
        fd_close_on_exec(inetd_login_fd, TRUE);
        foreground = TRUE;
    }

    /* read and verify settings before forking */
    master_settings_init();
    if (!master_settings_read(configfile, exec_protocol != NULL))
        exit(FATAL_DEFAULT);

    if (exec_protocol != NULL)
        mail_process_exec(exec_protocol, exec_section);

    /* we don't need any environment anymore */
    env_clean();

    open_fds();

    if (!foreground)
        daemonize(settings_root->defaults);

    ioloop = io_loop_create(system_pool);

    main_init();
        io_loop_run(ioloop);
    main_deinit();

    master_settings_deinit();
    io_loop_destroy(ioloop);
    lib_deinit();

        return 0;
}