src/imap/main.c

	main.c revision 2421fd34d51fed6da985c62b5e078d7e96640653
/* Copyright (c) 2002-2009 Dovecot authors, see the included COPYING file */

#include "common.h"
#include "ioloop.h"
#include "network.h"
#include "ostream.h"
#include "str.h"
#include "base64.h"
#include "istream.h"
#include "lib-signals.h"
#include "restrict-access.h"
#include "fd-close-on-exec.h"
#include "process-title.h"
#include "module-dir.h"
#include "dict.h"
#include "mail-storage.h"
#include "commands.h"
#include "mail-namespace.h"

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <syslog.h>

#define IS_STANDALONE() \
        (getenv("IMAPLOGINTAG") == NULL)

struct client_workaround_list {
    const char *name;
    enum client_workarounds num;
};

static struct client_workaround_list client_workaround_list[] = {
    { "delay-newmail", WORKAROUND_DELAY_NEWMAIL },
    { "outlook-idle", 0 }, /* only for backwards compatibility */
    { "netscape-eoh", WORKAROUND_NETSCAPE_EOH },
    { "tb-extra-mailbox-sep", WORKAROUND_TB_EXTRA_MAILBOX_SEP },
    { NULL, 0 }
};

struct ioloop *ioloop;
unsigned int imap_max_line_length;
enum client_workarounds client_workarounds = 0;
const char *logout_format;
const char *imap_id_send, *imap_id_log;

static struct io *log_io = NULL;
static struct module *modules = NULL;
static char log_prefix[128]; /* syslog() needs this to be permanent */

void (*hook_client_created)(struct client **client) = NULL;

string_t *capability_string;

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 log_error_callback(void *context ATTR_UNUSED)
{
    /* the log fd is closed, don't die when trying to log later */
    i_set_failure_ignore_errors(TRUE);

    io_loop_stop(ioloop);
}

static void parse_workarounds(void)
{
        struct client_workaround_list *list;
    const char *env, *const *str;

    env = getenv("IMAP_CLIENT_WORKAROUNDS");
    if (env == NULL)
        return;

    for (str = t_strsplit_spaces(env, " ,"); *str != NULL; str++) {
        list = client_workaround_list;
        for (; list->name != NULL; list++) {
            if (strcasecmp(*str, list->name) == 0) {
                client_workarounds |= list->num;
                break;
            }
        }
        if (list->name == NULL)
            i_fatal("Unknown client workaround: %s", *str);
    }
}

static void open_logfile(void)
{
    const char *user;

    if (getenv("LOG_TO_MASTER") != NULL) {
        i_set_failure_internal();
        return;
    }

    if (getenv("LOG_PREFIX") != NULL)
        i_strocpy(log_prefix, getenv("LOG_PREFIX"), sizeof(log_prefix));
    else {
        user = getenv("USER");
        if (user == NULL) {
            if (IS_STANDALONE())
                user = getlogin();
            if (user == NULL)
                user = "??";
        }
        if (strlen(user) >= sizeof(log_prefix)-6) {
            /* quite a long user name, cut it */
            user = t_strndup(user, sizeof(log_prefix)-6-2);
            user = t_strconcat(user, "..", NULL);
        }
        i_snprintf(log_prefix, sizeof(log_prefix), "imap(%s): ", user);
    }
    if (getenv("USE_SYSLOG") != NULL) {
        const char *env = getenv("SYSLOG_FACILITY");
        i_set_failure_syslog(log_prefix, LOG_NDELAY,
                     env == NULL ? LOG_MAIL : atoi(env));
    } else {
        /* log to file or stderr */
        i_set_failure_file(getenv("LOGFILE"), log_prefix);
    }

    if (getenv("INFOLOGFILE") != NULL)
        i_set_info_file(getenv("INFOLOGFILE"));

    i_set_failure_timestamp_format(getenv("LOGSTAMP"));
}

static void drop_privileges(void)
{
    const char *version;

    version = getenv("DOVECOT_VERSION");
    if (version != NULL && strcmp(version, PACKAGE_VERSION) != 0) {
        i_fatal("Dovecot version mismatch: "
            "Master is v%s, imap is v"PACKAGE_VERSION" "
            "(if you don't care, set version_ignore=yes)", version);
    }

    /* Log file or syslog opening probably requires roots */
    open_logfile();

    /* Load the plugins before chrooting. Their init() is called later. */
    if (getenv("MAIL_PLUGINS") != NULL) {
        const char *plugin_dir = getenv("MAIL_PLUGIN_DIR");

        if (plugin_dir == NULL)
            plugin_dir = MODULEDIR"/imap";
        modules = module_dir_load(plugin_dir, getenv("MAIL_PLUGINS"),
                      TRUE, version);
    }

    restrict_access_by_env(!IS_STANDALONE());
}

static void main_init(void)
{
    struct client *client;
    struct ostream *output;
    struct mail_user *user;
    const char *username, *home, *str, *tag;

    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, TRUE);
        lib_signals_ignore(SIGALRM, FALSE);

    username = getenv("USER");
    if (username == NULL) {
        if (IS_STANDALONE())
            username = getlogin();
        if (username == NULL)
            i_fatal("USER environment missing");
    }

    home = getenv("HOME");
    if (getenv("DEBUG") != NULL) {
        i_info("Effective uid=%s, gid=%s, home=%s",
               dec2str(geteuid()), dec2str(getegid()),
               home != NULL ? home : "(none)");
    }

    if (getenv("STDERR_CLOSE_SHUTDOWN") != NULL) {
        /* If master dies, the log fd gets closed and we'll quit */
        log_io = io_add(STDERR_FILENO, IO_ERROR,
                log_error_callback, NULL);
    }

    capability_string = str_new(default_pool, sizeof(CAPABILITY_STRING)+32);
    str_append(capability_string, CAPABILITY_STRING);

    dict_drivers_register_builtin();
    mail_users_init(getenv("AUTH_SOCKET_PATH"), getenv("DEBUG") != NULL);
        mail_storage_init();
    mail_storage_register_all();
    mailbox_list_register_all();
    clients_init();
    commands_init();

    module_dir_init(modules);

    if (getenv("DUMP_CAPABILITY") != NULL) {
        printf("%s\n", str_c(capability_string));
        exit(0);
    }

    str = getenv("IMAP_CAPABILITY");
    if (str != NULL && *str != '\0') {
        /* Overrides all capabilities */
        str_truncate(capability_string, 0);
        str_append(capability_string, str);
    }

    str = getenv("IMAP_MAX_LINE_LENGTH");
    imap_max_line_length = str != NULL ?
        (unsigned int)strtoul(str, NULL, 10) :
        DEFAULT_IMAP_MAX_LINE_LENGTH;

    logout_format = getenv("IMAP_LOGOUT_FORMAT");
    if (logout_format == NULL)
        logout_format = "bytes=%i/%o";

    imap_id_send = getenv("IMAP_ID_SEND");
    imap_id_log = getenv("IMAP_ID_LOG");

        parse_workarounds();

    user = mail_user_init(username);
    mail_user_set_home(user, home);
    if (mail_namespaces_init(user) < 0)
        i_fatal("Namespace initialization failed");
    client = client_create(0, 1, user);

    output = client->output;
    o_stream_ref(output);
    o_stream_cork(output);

    /* IMAPLOGINTAG environment is compatible with mailfront */
    tag = getenv("IMAPLOGINTAG");
    if (tag == NULL) {
        client_send_line(client, t_strconcat(
            "* PREAUTH [CAPABILITY ",
            str_c(capability_string), "] "
            "Logged in as ", user->username, NULL));
    } else {
        client_send_line(client, t_strconcat(
            tag, " OK [CAPABILITY ",
            str_c(capability_string), "] Logged in", NULL));
    }
    str = getenv("CLIENT_INPUT");
    if (str != NULL) T_BEGIN {
        buffer_t *buf = t_base64_decode_str(str);
        if (buf->used > 0) {
            if (!i_stream_add_data(client->input, buf->data,
                           buf->used))
                i_panic("Couldn't add client input to stream");
            (void)client_handle_input(client);
        }
    } T_END;
        o_stream_uncork(output);
    o_stream_unref(&output);
}

static void main_deinit(void)
{
    if (log_io != NULL)
        io_remove(&log_io);
    clients_deinit();

    module_dir_unload(&modules);
    commands_deinit();
    mail_storage_deinit();
    mail_users_deinit();
    dict_drivers_unregister_builtin();

    str_free(&capability_string);

    lib_signals_deinit();
    closelog();
}

int main(int argc ATTR_UNUSED, char *argv[], char *envp[])
{
#ifdef DEBUG
    if (!IS_STANDALONE() && getenv("GDB") == NULL)
        fd_debug_verify_leaks(3, 1024);
#endif
    if (IS_STANDALONE() && getuid() == 0 &&
        net_getpeername(1, NULL, NULL) == 0) {
        printf("* BAD [ALERT] imap binary must not be started from "
               "inetd, use imap-login instead.\n");
        return 1;
    }

    /* NOTE: we start rooted, so keep the code minimal until
       restrict_access_by_env() is called */
    lib_init();
    drop_privileges();

        process_title_init(argv, envp);
    ioloop = io_loop_create();

    /* fake that we're running, so we know if client was destroyed
       while initializing */
    io_loop_set_running(ioloop);
    main_init();
    if (io_loop_is_running(ioloop))
        io_loop_run(ioloop);
    main_deinit();

    io_loop_destroy(&ioloop);
    lib_deinit();

    return 0;
}