src/login-common/main.c

	main.c revision 5da4bfdce070b54ce8dfcd1bf6249798cda86bd6
/* Copyright (c) 2002-2012 Dovecot authors, see the included COPYING file */

#include "login-common.h"
#include "ioloop.h"
#include "randgen.h"
#include "process-title.h"
#include "restrict-access.h"
#include "restrict-process-size.h"
#include "master-auth.h"
#include "master-service.h"
#include "master-interface.h"
#include "client-common.h"
#include "access-lookup.h"
#include "anvil-client.h"
#include "auth-client.h"
#include "ssl-proxy.h"
#include "login-proxy.h"

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

#define DEFAULT_LOGIN_SOCKET "login"
#define AUTH_CLIENT_IDLE_TIMEOUT_MSECS (1000*60)

struct login_access_lookup {
    struct master_service_connection conn;
    struct io *io;

    char **sockets, **next_socket;
    struct access_lookup *access;
};

const struct login_binary *login_binary;
struct auth_client *auth_client;
struct master_auth *master_auth;
bool closing_down;
struct anvil_client *anvil;
const char *login_rawlog_dir = NULL;
unsigned int initial_service_count;

const struct login_settings *global_login_settings;
void **global_other_settings;

static struct timeout *auth_client_to;
static bool shutting_down = FALSE;
static bool ssl_connections = FALSE;
static bool auth_connected_once = FALSE;

static void login_access_lookup_next(struct login_access_lookup *lookup);

void login_refresh_proctitle(void)
{
    struct client *client = clients;
    const char *addr;

    if (!global_login_settings->verbose_proctitle)
        return;

    if (clients_get_count() == 0) {
        process_title_set("");
    } else if (clients_get_count() > 1 || client == NULL) {
        process_title_set(t_strdup_printf("[%u connections (%u TLS)]",
            clients_get_count(), ssl_proxy_get_count()));
    } else if ((addr = net_ip2addr(&client->ip)) != NULL) {
        process_title_set(t_strdup_printf(client->tls ?
                          "[%s TLS]" : "[%s]", addr));
    } else {
        process_title_set(client->tls ? "[TLS]" : "");
    }
}

static void auth_client_idle_timeout(struct auth_client *auth_client)
{
    i_assert(clients == NULL);

    auth_client_disconnect(auth_client, "idle disconnect");
    timeout_remove(&auth_client_to);
}

void login_client_destroyed(void)
{
    if (clients == NULL && auth_client_to == NULL) {
        auth_client_to = timeout_add(AUTH_CLIENT_IDLE_TIMEOUT_MSECS,
                         auth_client_idle_timeout,
                         auth_client);
    }
}

static void login_die(void)
{
    shutting_down = TRUE;
    login_proxy_kill_idle();

    if (!auth_client_is_connected(auth_client)) {
        /* we don't have auth client, and we might never get one */
        clients_destroy_all();
    }
}

static void
client_connected_finish(const struct master_service_connection *conn)
{
    struct client *client;
    struct ssl_proxy *proxy;
    struct ip_addr local_ip;
    const struct login_settings *set;
    unsigned int local_port;
    pool_t pool;
    int fd_ssl;
    void **other_sets;

    if (net_getsockname(conn->fd, &local_ip, &local_port) < 0) {
        memset(&local_ip, 0, sizeof(local_ip));
        local_port = 0;
    }

    pool = pool_alloconly_create("login client", 8*1024);
    set = login_settings_read(pool, &local_ip,
                  &conn->remote_ip, NULL, &other_sets);

    if (!ssl_connections && !conn->ssl) {
        client = client_create(conn->fd, FALSE, pool, set, other_sets,
                       &local_ip, &conn->remote_ip);
    } else {
        fd_ssl = ssl_proxy_alloc(conn->fd, &conn->remote_ip, pool, set,
                     &proxy);
        if (fd_ssl == -1) {
            net_disconnect(conn->fd);
            pool_unref(&pool);
            master_service_client_connection_destroyed(master_service);
            return;
        }

        client = client_create(fd_ssl, TRUE, pool, set, other_sets,
                       &local_ip, &conn->remote_ip);
        client->ssl_proxy = proxy;
        ssl_proxy_set_client(proxy, client);
        ssl_proxy_start(proxy);
    }

    client->remote_port = conn->remote_port;
    client->local_port = local_port;

    if (auth_client_to != NULL)
        timeout_remove(&auth_client_to);
}

static void login_access_lookup_free(struct login_access_lookup *lookup)
{
    if (lookup->io != NULL)
        io_remove(&lookup->io);
    if (lookup->access != NULL)
        access_lookup_destroy(&lookup->access);
    if (lookup->conn.fd != -1) {
        if (close(lookup->conn.fd) < 0)
            i_error("close(client) failed: %m");
        master_service_client_connection_destroyed(master_service);
    }

    p_strsplit_free(default_pool, lookup->sockets);
    i_free(lookup);
}

static void login_access_callback(bool success, void *context)
{
    struct login_access_lookup *lookup = context;

    if (!success) {
        i_info("access(%s): Client refused (rip=%s)",
               *lookup->next_socket,
               net_ip2addr(&lookup->conn.remote_ip));
        login_access_lookup_free(lookup);
    } else {
        lookup->next_socket++;
        login_access_lookup_next(lookup);
    }
}

static void login_access_lookup_next(struct login_access_lookup *lookup)
{
    if (*lookup->next_socket == NULL) {
        /* last one */
        if (lookup->io != NULL)
            io_remove(&lookup->io);
        client_connected_finish(&lookup->conn);
        lookup->conn.fd = -1;
        login_access_lookup_free(lookup);
        return;
    }
    lookup->access = access_lookup(*lookup->next_socket, lookup->conn.fd,
                       login_binary->protocol,
                       login_access_callback, lookup);
    if (lookup->access == NULL)
        login_access_lookup_free(lookup);
}

static void client_input_error(struct login_access_lookup *lookup)
{
    char c;
    int ret;

    ret = recv(lookup->conn.fd, &c, 1, MSG_PEEK);
    if (ret <= 0) {
        i_info("access(%s): Client disconnected during lookup (rip=%s)",
               *lookup->next_socket,
               net_ip2addr(&lookup->conn.remote_ip));
        login_access_lookup_free(lookup);
    } else {
        /* actual input. stop listening until lookup is done. */
        io_remove(&lookup->io);
    }
}

static void client_connected(struct master_service_connection *conn)
{
    const char *access_sockets =
        global_login_settings->login_access_sockets;
    struct login_access_lookup *lookup;

    master_service_client_connection_accept(conn);
    if (conn->remote_ip.family != 0) {
        /* log the connection's IP address in case we crash. it's of
           course possible that another earlier client causes the
           crash, but this is better than nothing. */
        i_set_failure_send_ip(&conn->remote_ip);
    }

    /* make sure we're connected (or attempting to connect) to auth */
    auth_client_connect(auth_client);

    if (*access_sockets == '\0') {
        /* no access checks */
        client_connected_finish(conn);
        return;
    }

    lookup = i_new(struct login_access_lookup, 1);
    lookup->conn = *conn;
    lookup->io = io_add(conn->fd, IO_READ, client_input_error, lookup);
    lookup->sockets = p_strsplit_spaces(default_pool, access_sockets, " ");
    lookup->next_socket = lookup->sockets;

    login_access_lookup_next(lookup);
}

static void auth_connect_notify(struct auth_client *client ATTR_UNUSED,
                bool connected, void *context ATTR_UNUSED)
{
    if (connected) {
        auth_connected_once = TRUE;
        clients_notify_auth_connected();
    } else if (shutting_down)
        clients_destroy_all();
    else if (!auth_connected_once) {
        /* auth disconnected without having ever succeeded, so the
           auth process is probably misconfigured. no point in
           keeping the client connections hanging. */
        clients_destroy_all_reason("Disconnected: Auth process broken");
    }
}

static bool anvil_reconnect_callback(void)
{
    /* we got disconnected from anvil. we can't reconnect to it since we're
       chrooted, so just die after we've finished handling the current
       connections. */
    master_service_stop_new_connections(master_service);
    return FALSE;
}

static void main_preinit(bool allow_core_dumps)
{
    unsigned int max_fds;

    random_init();
    /* Initialize SSL proxy so it can read certificate and private
       key file. */
    ssl_proxy_init();

    /* set the number of fds we want to use. it may get increased or
       decreased. leave a couple of extra fds for auth sockets and such.

       worst case each connection can use:

        - 1 for client
        - 1 for login proxy
        - 2 for client-side ssl proxy
        - 2 for server-side ssl proxy (with login proxy)
    */
    max_fds = MASTER_LISTEN_FD_FIRST + 16 +
        master_service_get_socket_count(master_service) +
        master_service_get_client_limit(master_service)*6;
    restrict_fd_limit(max_fds);
    io_loop_set_max_fd_count(current_ioloop, max_fds);

    i_assert(strcmp(global_login_settings->ssl, "no") == 0 ||
         ssl_initialized);

    if (global_login_settings->mail_max_userip_connections > 0) {
        anvil = anvil_client_init("anvil", anvil_reconnect_callback, 0);
        if (anvil_client_connect(anvil, TRUE) < 0)
            i_fatal("Couldn't connect to anvil");
    }

    restrict_access_by_env(NULL, TRUE);
    if (allow_core_dumps)
        restrict_access_allow_coredumps(TRUE);
    initial_service_count = master_service_get_service_count(master_service);

    if (restrict_access_get_current_chroot() == NULL) {
        if (chdir("login") < 0)
            i_fatal("chdir(login) failed: %m");
    }

    if (login_rawlog_dir != NULL &&
        access(login_rawlog_dir, W_OK | X_OK) < 0) {
        i_error("access(%s, wx) failed: %m - disabling rawlog",
            login_rawlog_dir);
        login_rawlog_dir = NULL;
    }
}

static void main_init(const char *login_socket)
{
    /* make sure we can't fork() */
    restrict_process_count(1);

    master_service_set_avail_overflow_callback(master_service,
                           client_destroy_oldest);
    master_service_set_die_callback(master_service, login_die);

    auth_client = auth_client_init(login_socket, (unsigned int)getpid(),
                       FALSE);
        auth_client_set_connect_notify(auth_client, auth_connect_notify, NULL);
    master_auth = master_auth_init(master_service, login_binary->protocol);

    login_binary->init();
    login_proxy_init("proxy-notify");
}

static void main_deinit(void)
{
    ssl_proxy_deinit();
    login_proxy_deinit();

    login_binary->deinit();
    auth_client_deinit(&auth_client);
    master_auth_deinit(&master_auth);

    if (anvil != NULL)
        anvil_client_deinit(&anvil);
    if (auth_client_to != NULL)
        timeout_remove(&auth_client_to);
    login_settings_deinit();
}

int login_binary_run(const struct login_binary *binary,
             int argc, char *argv[])
{
    enum master_service_flags service_flags =
        MASTER_SERVICE_FLAG_KEEP_CONFIG_OPEN |
        MASTER_SERVICE_FLAG_TRACK_LOGIN_STATE;
    pool_t set_pool;
    bool allow_core_dumps = FALSE;
    const char *login_socket = DEFAULT_LOGIN_SOCKET;
    int c;

    login_binary = binary;

    master_service = master_service_init(login_binary->process_name,
                         service_flags, &argc, &argv,
                         "DR:S");
    master_service_init_log(master_service, t_strconcat(
        login_binary->process_name, ": ", NULL));

    while ((c = master_getopt(master_service)) > 0) {
        switch (c) {
        case 'D':
            allow_core_dumps = TRUE;
            break;
        case 'R':
            login_rawlog_dir = optarg;
            break;
        case 'S':
            ssl_connections = TRUE;
            break;
        default:
            return FATAL_DEFAULT;
        }
    }
    if (argv[optind] != NULL)
        login_socket = argv[optind];

    login_binary->preinit();

    set_pool = pool_alloconly_create("global login settings", 4096);
    global_login_settings =
        login_settings_read(set_pool, NULL, NULL, NULL,
                    &global_other_settings);

    main_preinit(allow_core_dumps);
    master_service_init_finish(master_service);
    main_init(login_socket);

    master_service_run(master_service, client_connected);
    main_deinit();
    pool_unref(&set_pool);
    master_service_deinit(&master_service);
        return 0;
}