src/pop3/main.c

	main.c revision d4e141553b783ed96d0709ff52a6a41c0384206e


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/* Copyright (C) 2002-2003 Timo Sirainen */

#include "common.h"
#include "ioloop.h"
#include "file-lock.h"
#include "network.h"
#include "lib-signals.h"
#include "restrict-access.h"
#include "fd-close-on-exec.h"
#include "process-title.h"
#include "randgen.h"
#include "module-dir.h"
#include "var-expand.h"
#include "dict-client.h"
#include "mail-storage.h"

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

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

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

struct client_workaround_list client_workaround_list[] = {
    { "outlook-no-nuls", WORKAROUND_OUTLOOK_NO_NULS },
    { "oe-ns-eoh", WORKAROUND_OE_NS_EOH },
    { NULL, 0 }
};

struct ioloop *ioloop;

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

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

enum client_workarounds client_workarounds = 0;
bool enable_last_command = FALSE;
bool no_flag_updates = FALSE;
bool reuse_xuidl = FALSE;
bool lock_session = FALSE;
const char *uidl_format, *logout_format;
enum uidl_keys uidl_keymask;

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__)
{
    io_loop_stop(ioloop);
}

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

    env = getenv("POP3_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 enum uidl_keys parse_uidl_keymask(const char *format)
{
    enum uidl_keys mask = 0;

    for (; *format != '\0'; format++) {
        if (format[0] == '%' && format[1] != '\0') {
            switch (var_get_key(++format)) {
            case 'v':
                mask |= UIDL_UIDVALIDITY;
                break;
            case 'u':
                mask |= UIDL_UID;
                break;
            case 'm':
                mask |= UIDL_MD5;
                break;
            case 'f':
                mask |= UIDL_FILE_NAME;
                break;
            }
        }
    }
    return mask;
}

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

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

    if (getenv("LOG_PREFIX") != NULL)
        strocpy(log_prefix, getenv("LOG_PREFIX"), sizeof(log_prefix));
    else {
        user = getenv("USER");
        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), "pop3(%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, pop3 is v"PACKAGE_VERSION" "
            "(if you don't care, set version_ignore=yes)", version);
    }

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

    /* Most likely needed. Have to open /dev/urandom before possible
       chrooting. */
    random_init();

    /* 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"/pop3";
        modules = module_dir_load(plugin_dir, getenv("MAIL_PLUGINS"),
                      TRUE, version);
    }

    restrict_access_by_env(!IS_STANDALONE());
}

static int main_init(void)
{
        enum mail_storage_flags flags;
        enum file_lock_method lock_method;
    struct mail_storage *storage;
    const char *mail;

    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);

    if (getenv("USER") == NULL)
        i_fatal("USER environment missing");

    if (getenv("DEBUG") != NULL) {
        i_info("Effective uid=%s, gid=%s",
               dec2str(geteuid()), dec2str(getegid()));
    }

    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);
    }

    dict_driver_register(&dict_driver_client);
        mail_storage_init();
    mail_storage_register_all();
    mailbox_list_register_all();
    clients_init();

    module_dir_init(modules);

    mail = getenv("MAIL");
    if (mail == NULL) {
        /* support also maildir-specific environment */
        mail = getenv("MAILDIR");
        if (mail != NULL)
            mail = t_strconcat("maildir:", mail, NULL);
    }

    parse_workarounds();
    enable_last_command = getenv("POP3_ENABLE_LAST") != NULL;
    no_flag_updates = getenv("POP3_NO_FLAG_UPDATES") != NULL;
    reuse_xuidl = getenv("POP3_REUSE_XUIDL") != NULL;
    lock_session = getenv("POP3_LOCK_SESSION") != NULL;

    uidl_format = getenv("POP3_UIDL_FORMAT");
    if (uidl_format == NULL || *uidl_format == '\0')
        i_fatal("Set pop3_uidl_format in config file");
    logout_format = getenv("POP3_LOGOUT_FORMAT");
    if (logout_format == NULL)
        logout_format = "top=%t/%p, retr=%r/%b, del=%d/%m, size=%s";
    uidl_keymask = parse_uidl_keymask(uidl_format);
    if (uidl_keymask == 0)
        i_fatal("pop3_uidl_format setting doesn't contain any "
            "%% variables.");

    mail_storage_parse_env(&flags, &lock_method);
    storage = mail_storage_create_with_data(mail, getenv("USER"),
                        flags, lock_method);
    if (storage == NULL) {
        /* failed */
        if (mail != NULL && *mail != '\0')
            i_fatal("Failed to create storage with data: %s", mail);
        else {
            const char *home;

            home = getenv("HOME");
            if (home == NULL) home = "not set";

            i_fatal("MAIL environment missing and "
                "autodetection failed (home %s)", home);
        }
    }

    return client_create(0, 1, storage) != NULL;
}

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

    module_dir_unload(&modules);
    mail_storage_deinit();
    dict_driver_unregister(&dict_driver_client);
    random_deinit();

    lib_signals_deinit();
    closelog();
}

int main(int argc __attr_unused__, char *argv[], char *envp[])
{
#ifdef DEBUG
    if (getenv("LOGGED_IN") != NULL && getenv("GDB") == NULL)
        fd_debug_verify_leaks(3, 1024);
#endif
    if (IS_STANDALONE() && getuid() == 0 &&
        net_getpeername(1, NULL, NULL) == 0) {
        printf("-ERR pop3 binary must not be started from "
               "inetd, use pop3-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();

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

    io_loop_destroy(&ioloop);
    lib_deinit();

    return 0;
}