src/master/main.c

	main.c revision b0822c7c04d142ad5b0a07c5fa49c0723a276d91
/* 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 "askpass.h"
#include "auth-process.h"
#include "dict-process.h"
#include "login-process.h"
#include "mail-process.h"
#include "syslog-util.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",
    "auth-worker",
    "login",
    "imap",
    "pop3",
    "ssl-build-param",
    "dict"
};

static const char *configfile = SYSCONFDIR "/" PACKAGE ".conf";
static const char *env_tz;

struct ioloop *ioloop;
struct hash_table *pids;
int null_fd, inetd_login_fd;
uid_t master_uid;
char program_path[PATH_MAX];
char ssl_manual_key_password[100];
#ifdef DEBUG
static bool gdb;
#endif

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

bool 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)
{
    int facility;

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

    /* we'll log through master process */
    env_put("LOG_TO_MASTER=1");
    if (env_tz != NULL)
        env_put(t_strconcat("TZ=", env_tz, NULL));

    if (settings_root == NULL ||
        !syslog_facility_find(settings_root->defaults->syslog_facility,
                  &facility))
        facility = LOG_MAIL;
    env_put(t_strdup_printf("SYSLOG_FACILITY=%d", facility));

    if (settings_root != NULL && !settings_root->defaults->version_ignore)
        env_put("DOVECOT_VERSION="PACKAGE_VERSION);
#ifdef DEBUG
    if (gdb) env_put("GDB=1");
#endif
}

void client_process_exec(const char *cmd, const char *title)
{
    const char *executable, *p, **argv;

    /* very simple argument splitting. */
    if (*title == '\0')
        argv = t_strsplit(cmd, " ");
    else
        argv = t_strsplit(t_strconcat(cmd, " ", title, NULL), " ");

    executable = argv[0];

    /* hide the path, it's ugly */
    p = strrchr(argv[0], '/');
    if (p != NULL) argv[0] = p+1;

    execv(executable, (char **)argv);
}

static void set_logfile(struct settings *set)
{
    int facility;

    if (*set->log_path == '\0') {
        if (!syslog_facility_find(set->syslog_facility, &facility))
            facility = LOG_MAIL;

        i_set_failure_syslog("dovecot", LOG_NDELAY, facility);
    } else {
        /* log to file or stderr */
        i_set_failure_file(set->log_path, "dovecot");
    }

    if (*set->info_log_path != '\0')
        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();
        dict_process_kill();

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

static void sig_die(int signo, void *context __attr_unused__)
{
    /* warn about being killed because of some signal, except SIGINT (^C)
       which is too common at least while testing :) */
    if (signo != SIGINT)
        i_warning("Killed with signal %d", signo);
    io_loop_stop(ioloop);
}

static void sig_reload_settings(int signo __attr_unused__,
                void *context __attr_unused__)
{
    settings_reload();
}

static void sig_reopen_logs(int signo __attr_unused__,
                void *context __attr_unused__)
{
    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 sigchld_handler(int signo __attr_unused__,
                void *context __attr_unused__)
{
    const char *process_type_name, *msg;
    pid_t pid;
    int status, process_type;
    bool abnormal_exit;

    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);

        abnormal_exit = TRUE;

        /* write errors to syslog */
        process_type_name = process_names[process_type];
        if (WIFEXITED(status)) {
            status = WEXITSTATUS(status);
            if (status == 0)
                abnormal_exit = FALSE;
            else {
                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)) {
            i_error("child %s (%s) killed with signal %d",
                dec2str(pid), process_type_name,
                WTERMSIG(status));
        }

        switch (process_type) {
        case PROCESS_TYPE_LOGIN:
            login_process_destroyed(pid, abnormal_exit);
            break;
        case PROCESS_TYPE_IMAP:
        case PROCESS_TYPE_POP3:
            mail_process_destroyed(pid);
            break;
        case PROCESS_TYPE_SSL_PARAM:
            ssl_parameter_process_destroyed(pid);
            break;
        case PROCESS_TYPE_DICT:
            dict_process_restart();
            break;
        }
    }

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

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

    if (*name == '\0') {
                /* defaults to "*" or "[::]" */
        ip->family = 0;
        return;
    }

    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 */
        net_get_ip_any4(ip);
        return;
    }

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

    /* Return the first IP if there happens to be multiple. */
    ret = net_gethostbyname(name, &ip_list, &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);

    *ip = ip_list[0];
}

static void
check_conflicts_set(const struct settings *set, const struct ip_addr *ip,
            unsigned int port, const char *name1, const char *name2)
{
    if (set->listen_port == port && net_ip_compare(ip, &set->listen_ip) &&
        set->listen_fd > 0) {
        i_fatal("Protocols %s and %s are listening in same ip/port",
            name1, name2);
    }
    if (set->ssl_listen_port == port &&
        net_ip_compare(ip, &set->ssl_listen_ip) && set->ssl_listen_fd > 0) {
        i_fatal("Protocols %ss and %s are listening in same ip/port",
            name1, name2);
    }
}

static void check_conflicts(const struct ip_addr *ip, unsigned int port,
                const char *proto)
{
    struct server_settings *server;

    for (server = settings_root; server != NULL; server = server->next) {
        if (server->imap != NULL) {
            check_conflicts_set(server->imap, ip, port,
                        "imap", proto);
        }
        if (server->pop3 != NULL) {
            check_conflicts_set(server->pop3, ip, port,
                        "pop3", proto);
        }
    }
}

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

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

    /* resolve */
    resolve_ip(set->listen, &set->listen_ip, &set->listen_port);
    resolve_ip(set->ssl_listen, &set->ssl_listen_ip, &set->ssl_listen_port);

    /* if ssl_listen wasn't explicitly set in the config file,
       use the non-ssl IP settings for the ssl listener, too. */
    if (set->ssl_listen_ip.family == 0 && *set->ssl_listen == '\0')
        set->ssl_listen_ip = set->listen_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 = set->listen_port;
                ip = &set->listen_ip;
            }
        } else if (strcasecmp(*proto, "imaps") == 0) {
            if (set->protocol == MAIL_PROTOCOL_IMAP &&
                !set->ssl_disable) {
                fd = &set->ssl_listen_fd;
                port = set->ssl_listen_port;
                ip = &set->ssl_listen_ip;
            }
        } else if (strcasecmp(*proto, "pop3") == 0) {
            if (set->protocol == MAIL_PROTOCOL_POP3) {
                fd = &set->listen_fd;
                port = set->listen_port;
                ip = &set->listen_ip;
            }
        } else if (strcasecmp(*proto, "pop3s") == 0) {
            if (set->protocol == MAIL_PROTOCOL_POP3 &&
                !set->ssl_disable) {
                fd = &set->ssl_listen_fd;
                port = set->ssl_listen_port;
                ip = &set->ssl_listen_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, 8);
                if (*fd != -1 || errno != EADDRINUSE)
                    break;

                check_conflicts(ip, port, *proto);
                if (!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(bool 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 bool have_stderr_set(struct settings *set)
{
    if (*set->log_path != '\0' &&
        strcmp(set->log_path, "/dev/stderr") == 0)
        return TRUE;

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

    return FALSE;
}

static bool 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);
        if (null_fd == -1)
            i_fatal("dup(null_fd) failed: %m");
        fd_close_on_exec(null_fd, TRUE);
    }

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

    /* close stdin and stdout. */
    if (dup2(null_fd, 0) < 0)
        i_fatal("dup2(0) failed: %m");
    if (dup2(null_fd, 1) < 0)
        i_fatal("dup2(1) 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);

    /* close stderr unless we're logging into /dev/stderr. keep as little
       distance between closing it and opening the actual log file so that
       we don't lose anything. */
    if (!have_stderr(settings_root)) {
        if (dup2(null_fd, 2) < 0)
            i_fatal("dup2(2) failed: %m");
    }

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

    log_init();

    lib_signals_init();
        lib_signals_set_handler(SIGINT, TRUE, sig_die, NULL);
        lib_signals_set_handler(SIGTERM, TRUE, sig_die, NULL);
        lib_signals_ignore(SIGPIPE);
        lib_signals_set_handler(SIGALRM, FALSE, NULL, NULL);
        lib_signals_set_handler(SIGHUP, TRUE, sig_reload_settings, NULL);
        lib_signals_set_handler(SIGUSR1, TRUE, sig_reopen_logs, NULL);

    pids = hash_create(default_pool, default_pool, 128, NULL, NULL);
    lib_signals_set_handler(SIGCHLD, TRUE, sigchld_handler, NULL);

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

    /* make sure we log if child processes died unexpectedly */
    sigchld_handler(SIGCHLD, NULL);

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

    lib_signals_unset_handler(SIGCHLD, sigchld_handler, NULL);

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

    hash_destroy(pids);
    lib_signals_deinit();
    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>] [-p] [-n] [-a]\n"
"       [--exec-mail <protocol>] [--version] [--build-options]\n");
}

static void print_build_options(void)
{
    printf("Build options:"
#ifdef IOLOOP_EPOLL
        " ioloop=epoll"
#endif
#ifdef IOLOOP_KQUEUE
        " ioloop=kqueue"
#endif
#ifdef IOLOOP_POLL
        " ioloop=poll"
#endif
#ifdef IOLOOP_SELECT
        " ioloop=select"
#endif
#ifdef IOLOOP_NOTIFY_DNOTIFY
        " notify=dnotify"
#endif
#ifdef IOLOOP_NOTIFY_INOTIFY
        " notify=inotify"
#endif
#ifdef IOLOOP_NOTIFY_KQUEUE
        " notify=kqueue"
#endif
#ifdef HAVE_IPV6
        " ipv6"
#endif
#ifdef HAVE_GNUTLS
        " gnutls"
#endif
#ifdef HAVE_OPENSSL
        " openssl"
#endif
    "\nSQL drivers:"
#ifdef BUILD_MYSQL
        " mysql"
#endif
#ifdef BUILD_PGSQL
        " postgresql"
#endif
#ifdef BUILD_SQLITE
        " sqlite"
#endif
    "\nPassdb:"
#ifdef PASSDB_BSDAUTH
        " bsdauth"
#endif
#ifdef PASSDB_CHECKPASSWORD
        " checkpassword"
#endif
#ifdef PASSDB_LDAP
        " ldap"
#endif
#ifdef PASSDB_PAM
        " pam"
#endif
#ifdef PASSDB_PASSWD
        " passwd"
#endif
#ifdef PASSDB_PASSWD_FILE
        " passwd-file"
#endif
#ifdef PASSDB_SHADOW
        " shadow"
#endif
#ifdef PASSDB_SQL
        " sql"
#endif
#ifdef PASSDB_VPOPMAIL
        " vpopmail"
#endif
    "\nUserdb:"
#ifdef USERDB_CHECKPASSWORD
        " checkpassword"
#endif
#ifdef USERDB_LDAP
        " ldap"
#endif
#ifdef USERDB_PASSWD
        " passwd"
#endif
#ifdef USERDB_PREFETCH
        " prefetch"
#endif
#ifdef USERDB_PASSWD_FILE
        " passwd-file"
#endif
#ifdef USERDB_SQL
        " sql"
#endif
#ifdef USERDB_STATIC
        " static"
#endif
#ifdef USERDB_VPOPMAIL
        " vpopmail"
#endif
    "\n");
}

int main(int argc, char *argv[])
{
    /* parse arguments */
    const char *exec_protocol = NULL, *exec_section = NULL, *user, *home;
    bool foreground = FALSE, ask_key_pass = FALSE;
    bool dump_config = FALSE, dump_config_nondefaults = 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], "-a") == 0) {
            dump_config = 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], "-n") == 0) {
            dump_config_nondefaults = TRUE;
        } else if (strcmp(argv[i], "-p") == 0) {
            /* Ask SSL private key password */
            ask_key_pass = TRUE;
        } 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 if (strcmp(argv[i], "--build-options") == 0) {
            print_build_options();
            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;
    }

    if (dump_config || dump_config_nondefaults) {
        /* print the config file path before parsing it, so in case
           of errors it's still shown */
        printf("# %s\n", configfile);
    }

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

    if (dump_config || dump_config_nondefaults) {
        master_settings_dump(settings_root, dump_config_nondefaults);
        return 0;
    }

    if (ask_key_pass) {
        const char *prompt;

        t_push();
        prompt = t_strdup_printf("Give the password for SSL key file "
                     "%s: ",
                     settings_root->defaults->ssl_key_file);
        askpass(prompt, ssl_manual_key_password,
            sizeof(ssl_manual_key_password));
        t_pop();
    }

    /* save TZ environment. AIX depends on it to get the timezone
       correctly. */
    env_tz = getenv("TZ");
    user = getenv("USER");
    home = getenv("HOME");

    /* clean up the environment of everything */
    env_clean();

    /* put back the TZ */
    if (env_tz != NULL)
        env_put(t_strconcat("TZ=", env_tz, NULL));

    if (exec_protocol != NULL) {
        /* Put back user and home */
        env_put(t_strconcat("USER=", user, NULL));
        env_put(t_strconcat("HOME=", home, NULL));
        mail_process_exec(exec_protocol, exec_section);
    }

    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;
}