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[heimdal.git] / lib / kadm5 / ipropd_slave.c

/*
 * Copyright (c) 1997 - 2008 Kungliga Tekniska Högskolan
 * (Royal Institute of Technology, Stockholm, Sweden).
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * 3. Neither the name of the Institute nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "iprop.h"

RCSID("$Id$");

static const char *config_name = "ipropd-slave";

static krb5_log_facility *log_facility;
static char five_min[] = "5 min";
static char *server_time_lost = five_min;
static int time_before_lost;
const char *slave_str = NULL;

static int
connect_to_master (krb5_context context, const char *master,
                   const char *port_str)
{
    char port[NI_MAXSERV];
    struct addrinfo *ai, *a;
    struct addrinfo hints;
    int error;
    int s = -1;

    memset (&hints, 0, sizeof(hints));
    hints.ai_socktype = SOCK_STREAM;

    if (port_str == NULL) {
        snprintf(port, sizeof(port), "%u", IPROP_PORT);
        port_str = port;
    }

    error = getaddrinfo (master, port_str, &hints, &ai);
    if (error) {
        krb5_warnx(context, "Failed to get address of to %s: %s",
                   master, gai_strerror(error));
        return -1;
    }

    for (a = ai; a != NULL; a = a->ai_next) {
        char node[NI_MAXHOST];
        error = getnameinfo(a->ai_addr, a->ai_addrlen,
                            node, sizeof(node), NULL, 0, NI_NUMERICHOST);
        if (error)
            strlcpy(node, "[unknown-addr]", sizeof(node));

        s = socket (a->ai_family, a->ai_socktype, a->ai_protocol);
        if (s < 0)
            continue;
        if (connect (s, a->ai_addr, a->ai_addrlen) < 0) {
            krb5_warn(context, errno, "connection failed to %s[%s]",
                      master, node);
            close (s);
            continue;
        }
        krb5_warnx(context, "connection successful "
                   "to master: %s[%s]", master, node);
        break;
    }
    freeaddrinfo (ai);

    if (a == NULL)
        return -1;

    return s;
}

static void
get_creds(krb5_context context, const char *keytab_str,
          krb5_ccache *cache, const char *serverhost)
{
    krb5_keytab keytab;
    krb5_principal client;
    krb5_error_code ret;
    krb5_get_init_creds_opt *init_opts;
    krb5_creds creds;
    char *server;
    char keytab_buf[256];

    if (keytab_str == NULL) {
        ret = krb5_kt_default_name (context, keytab_buf, sizeof(keytab_buf));
        if (ret)
            krb5_err (context, 1, ret, "krb5_kt_default_name");
        keytab_str = keytab_buf;
    }

    ret = krb5_kt_resolve(context, keytab_str, &keytab);
    if(ret)
        krb5_err(context, 1, ret, "%s", keytab_str);


    ret = krb5_sname_to_principal (context, slave_str, IPROP_NAME,
                                   KRB5_NT_SRV_HST, &client);
    if (ret) krb5_err(context, 1, ret, "krb5_sname_to_principal");

    ret = krb5_get_init_creds_opt_alloc(context, &init_opts);
    if (ret) krb5_err(context, 1, ret, "krb5_get_init_creds_opt_alloc");

    asprintf (&server, "%s/%s", IPROP_NAME, serverhost);
    if (server == NULL)
        krb5_errx (context, 1, "malloc: no memory");

    ret = krb5_get_init_creds_keytab(context, &creds, client, keytab,
                                     0, server, init_opts);
    free (server);
    krb5_get_init_creds_opt_free(context, init_opts);
    if(ret) krb5_err(context, 1, ret, "krb5_get_init_creds");

    ret = krb5_kt_close(context, keytab);
    if(ret) krb5_err(context, 1, ret, "krb5_kt_close");

    ret = krb5_cc_new_unique(context, krb5_cc_type_memory, NULL, cache);
    if(ret) krb5_err(context, 1, ret, "krb5_cc_new_unique");

    ret = krb5_cc_initialize(context, *cache, client);
    if(ret) krb5_err(context, 1, ret, "krb5_cc_initialize");

    ret = krb5_cc_store_cred(context, *cache, &creds);
    if(ret) krb5_err(context, 1, ret, "krb5_cc_store_cred");

    krb5_free_cred_contents(context, &creds);
    krb5_free_principal(context, client);
}

static krb5_error_code
ihave (krb5_context context, krb5_auth_context auth_context,
       int fd, uint32_t version)
{
    int ret;
    u_char buf[8];
    krb5_storage *sp;
    krb5_data data;

    sp = krb5_storage_from_mem (buf, 8);
    krb5_store_int32 (sp, I_HAVE);
    krb5_store_int32 (sp, version);
    krb5_storage_free (sp);
    data.length = 8;
    data.data   = buf;

    ret = krb5_write_priv_message(context, auth_context, &fd, &data);
    if (ret)
        krb5_warn (context, ret, "krb5_write_message");
    return ret;
}

static void
receive_loop (krb5_context context,
              krb5_storage *sp,
              kadm5_server_context *server_context)
{
    int ret;
    off_t left, right;
    void *buf;
    int32_t vers, vers2;
    ssize_t sret;

    /*
     * Seek to the current version of the local database.
     */
    do {
        int32_t len, timestamp, tmp;
        enum kadm_ops op;

        if(krb5_ret_int32 (sp, &vers) != 0)
            return;
        krb5_ret_int32 (sp, &timestamp);
        krb5_ret_int32 (sp, &tmp);
        op = tmp;
        krb5_ret_int32 (sp, &len);
        if ((uint32_t)vers <= server_context->log_context.version)
            krb5_storage_seek(sp, len + 8, SEEK_CUR);
    } while((uint32_t)vers <= server_context->log_context.version);

    /*
     * Read up rest of the entires into the memory...
     */
    left  = krb5_storage_seek (sp, -16, SEEK_CUR);
    right = krb5_storage_seek (sp, 0, SEEK_END);
    buf = malloc (right - left);
    if (buf == NULL && (right - left) != 0)
        krb5_errx (context, 1, "malloc: no memory");

    /*
     * ...and then write them out to the on-disk log.
     */
    krb5_storage_seek (sp, left, SEEK_SET);
    krb5_storage_read (sp, buf, right - left);
    sret = write (server_context->log_context.log_fd, buf, right-left);
    if (sret != right - left)
        krb5_err(context, 1, errno, "Failed to write log to disk");
    ret = fsync (server_context->log_context.log_fd);
    if (ret)
        krb5_err(context, 1, errno, "Failed to sync log to disk");
    free (buf);

    /*
     * Go back to the startpoint and start to commit the entires to
     * the database.
     */
    krb5_storage_seek (sp, left, SEEK_SET);

    for(;;) {
        int32_t len, len2, timestamp, tmp;
        off_t cur, cur2;
        enum kadm_ops op;

        if(krb5_ret_int32 (sp, &vers) != 0)
            break;
        ret = krb5_ret_int32 (sp, &timestamp);
        if (ret) krb5_errx(context, 1, "entry %ld: too short", (long)vers);
        ret = krb5_ret_int32 (sp, &tmp);
        if (ret) krb5_errx(context, 1, "entry %ld: too short", (long)vers);
        op = tmp;
        ret = krb5_ret_int32 (sp, &len);
        if (ret) krb5_errx(context, 1, "entry %ld: too short", (long)vers);
        if (len < 0)
            krb5_errx(context, 1, "log is corrupted, "
                      "negative length of entry version %ld: %ld",
                      (long)vers, (long)len);
        cur = krb5_storage_seek(sp, 0, SEEK_CUR);

        krb5_warnx (context, "replaying entry %d", (int)vers);

        ret = kadm5_log_replay (server_context,
                                op, vers, len, sp);
        if (ret) {
            const char *s = krb5_get_error_message(server_context->context, ret);
            krb5_warnx (context,
                        "kadm5_log_replay: %ld. Lost entry entry, "
                        "Database out of sync ?: %s (%d)",
                        (long)vers, s ? s : "unknown error", ret);
            krb5_free_error_message(context, s);
        }

        {
            /*
             * Make sure the krb5_log_replay does the right thing wrt
             * reading out data from the sp.
             */
            cur2 = krb5_storage_seek(sp, 0, SEEK_CUR);
            if (cur + len != cur2)
                krb5_errx(context, 1,
                          "kadm5_log_reply version: %ld didn't read the whole entry",
                          (long)vers);
        }

        if (krb5_ret_int32 (sp, &len2) != 0)
            krb5_errx(context, 1, "entry %ld: postamble too short", (long)vers);
        if(krb5_ret_int32 (sp, &vers2) != 0)
            krb5_errx(context, 1, "entry %ld: postamble too short", (long)vers);

        if (len != len2)
            krb5_errx(context, 1, "entry %ld: len != len2", (long)vers);
        if (vers != vers2)
            krb5_errx(context, 1, "entry %ld: vers != vers2", (long)vers);
    }

    /*
     * Update version
     */

    server_context->log_context.version = vers;
}

static void
receive (krb5_context context,
         krb5_storage *sp,
         kadm5_server_context *server_context)
{
    int ret;

    ret = server_context->db->hdb_open(context,
                                       server_context->db,
                                       O_RDWR | O_CREAT, 0600);
    if (ret)
        krb5_err (context, 1, ret, "db->open");

    receive_loop (context, sp, server_context);

    ret = server_context->db->hdb_close (context, server_context->db);
    if (ret)
        krb5_err (context, 1, ret, "db->close");
}

static void
send_im_here (krb5_context context, int fd,
              krb5_auth_context auth_context)
{
    krb5_storage *sp;
    krb5_data data;
    int ret;

    ret = krb5_data_alloc (&data, 4);
    if (ret)
        krb5_err (context, 1, ret, "send_im_here");

    sp = krb5_storage_from_data (&data);
    if (sp == NULL)
        krb5_errx (context, 1, "krb5_storage_from_data");
    krb5_store_int32(sp, I_AM_HERE);
    krb5_storage_free(sp);

    ret = krb5_write_priv_message(context, auth_context, &fd, &data);
    krb5_data_free(&data);

    if (ret)
        krb5_err (context, 1, ret, "krb5_write_priv_message");
}

static krb5_error_code
receive_everything (krb5_context context, int fd,
                    kadm5_server_context *server_context,
                    krb5_auth_context auth_context)
{
    int ret;
    krb5_data data;
    int32_t vno = 0;
    int32_t opcode;
    krb5_storage *sp;

    char *dbname;
    HDB *mydb;

    krb5_warnx(context, "receive complete database");

    asprintf(&dbname, "%s-NEW", server_context->db->hdb_name);
    ret = hdb_create(context, &mydb, dbname);
    if(ret)
        krb5_err(context,1, ret, "hdb_create");
    free(dbname);

    ret = hdb_set_master_keyfile (context,
                                  mydb, server_context->config.stash_file);
    if(ret)
        krb5_err(context,1, ret, "hdb_set_master_keyfile");

    /* I really want to use O_EXCL here, but given that I can't easily clean
       up on error, I won't */
    ret = mydb->hdb_open(context, mydb, O_RDWR | O_CREAT | O_TRUNC, 0600);
    if (ret)
        krb5_err (context, 1, ret, "db->open");

    sp = NULL;
    do {
        ret = krb5_read_priv_message(context, auth_context, &fd, &data);

        if (ret) {
            krb5_warn (context, ret, "krb5_read_priv_message");
            goto cleanup;
        }

        sp = krb5_storage_from_data (&data);
        if (sp == NULL)
            krb5_errx (context, 1, "krb5_storage_from_data");
        krb5_ret_int32 (sp, &opcode);
        if (opcode == ONE_PRINC) {
            krb5_data fake_data;
            hdb_entry_ex entry;

            krb5_storage_free(sp);

            fake_data.data   = (char *)data.data + 4;
            fake_data.length = data.length - 4;

            memset(&entry, 0, sizeof(entry));

            ret = hdb_value2entry (context, &fake_data, &entry.entry);
            if (ret)
                krb5_err (context, 1, ret, "hdb_value2entry");
            ret = mydb->hdb_store(server_context->context,
                                  mydb,
                                  0, &entry);
            if (ret)
                krb5_err (context, 1, ret, "hdb_store");

            hdb_free_entry (context, &entry);
            krb5_data_free (&data);
        } else if (opcode == NOW_YOU_HAVE)
            ;
        else
            krb5_errx (context, 1, "strange opcode %d", opcode);
    } while (opcode == ONE_PRINC);

    if (opcode != NOW_YOU_HAVE)
        krb5_errx (context, 1, "receive_everything: strange %d", opcode);

    krb5_ret_int32 (sp, &vno);
    krb5_storage_free(sp);

    ret = kadm5_log_reinit (server_context);
    if (ret)
        krb5_err(context, 1, ret, "kadm5_log_reinit");

    ret = kadm5_log_set_version (server_context, vno - 1);
    if (ret)
        krb5_err (context, 1, ret, "kadm5_log_set_version");

    ret = kadm5_log_nop (server_context);
    if (ret)
        krb5_err (context, 1, ret, "kadm5_log_nop");

    ret = mydb->hdb_rename (context, mydb, server_context->db->hdb_name);
    if (ret)
        krb5_err (context, 1, ret, "db->rename");

 cleanup:
    krb5_data_free (&data);

    ret = mydb->hdb_close (context, mydb);
    if (ret)
        krb5_err (context, 1, ret, "db->close");

    ret = mydb->hdb_destroy (context, mydb);
    if (ret)
        krb5_err (context, 1, ret, "db->destroy");

    krb5_warnx(context, "receive complete database, version %ld", (long)vno);
    return ret;
}

static char *config_file;
static char *realm;
static int version_flag;
static int help_flag;
static char *keytab_str;
static char *port_str;
#ifdef SUPPORT_DETACH
static int detach_from_console = 0;
#endif

static struct getargs args[] = {
    { "config-file", 'c', arg_string, &config_file, NULL, NULL },
    { "realm", 'r', arg_string, &realm, NULL, NULL },
    { "keytab", 'k', arg_string, &keytab_str,
      "keytab to get authentication from", "kspec" },
    { "time-lost", 0, arg_string, &server_time_lost,
      "time before server is considered lost", "time" },
    { "port", 0, arg_string, &port_str,
      "port ipropd-slave will connect to", "port"},
#ifdef SUPPORT_DETACH
    { "detach", 0, arg_flag, &detach_from_console,
      "detach from console", NULL },
#endif
    { "hostname", 0, arg_string, rk_UNCONST(&slave_str),
      "hostname of slave (if not same as hostname)", "hostname" },
    { "version", 0, arg_flag, &version_flag, NULL, NULL },
    { "help", 0, arg_flag, &help_flag, NULL, NULL }
};

static int num_args = sizeof(args) / sizeof(args[0]);

static void
usage(int status)
{
    arg_printusage(args, num_args, NULL, "master");
    exit(status);
}

int
main(int argc, char **argv)
{
    krb5_error_code ret;
    krb5_context context;
    krb5_auth_context auth_context;
    void *kadm_handle;
    kadm5_server_context *server_context;
    kadm5_config_params conf;
    int master_fd;
    krb5_ccache ccache;
    krb5_principal server;
    char **files;
    int optidx = 0;
    time_t reconnect_min;
    time_t backoff;
    time_t reconnect_max;
    time_t reconnect;
    time_t before = 0;

    const char *master;

    setprogname(argv[0]);

    if(getarg(args, num_args, argc, argv, &optidx))
        usage(1);

    if(help_flag)
        usage(0);
    if(version_flag) {
        print_version(NULL);
        exit(0);
    }

    ret = krb5_init_context(&context);
    if (ret)
        errx (1, "krb5_init_context failed: %d", ret);

    setup_signal();

    if (config_file == NULL) {
        if (asprintf(&config_file, "%s/kdc.conf", hdb_db_dir(context)) == -1
            || config_file == NULL)
            errx(1, "out of memory");
    }

    ret = krb5_prepend_config_files_default(config_file, &files);
    if (ret)
        krb5_err(context, 1, ret, "getting configuration files");

    ret = krb5_set_config_files(context, files);
    krb5_free_config_files(files);
    if (ret)
        krb5_err(context, 1, ret, "reading configuration files");

    argc -= optidx;
    argv += optidx;

    if (argc != 1)
        usage(1);

    master = argv[0];

#ifdef SUPPORT_DETACH
    if (detach_from_console)
        daemon(0, 0);
#endif
    pidfile (NULL);
    krb5_openlog (context, "ipropd-slave", &log_facility);
    krb5_set_warn_dest(context, log_facility);

    ret = krb5_kt_register(context, &hdb_kt_ops);
    if(ret)
        krb5_err(context, 1, ret, "krb5_kt_register");

    time_before_lost = parse_time (server_time_lost,  "s");
    if (time_before_lost < 0)
        krb5_errx (context, 1, "couldn't parse time: %s", server_time_lost);

    memset(&conf, 0, sizeof(conf));
    if(realm) {
        conf.mask |= KADM5_CONFIG_REALM;
        conf.realm = realm;
    }
    ret = kadm5_init_with_password_ctx (context,
                                        KADM5_ADMIN_SERVICE,
                                        NULL,
                                        KADM5_ADMIN_SERVICE,
                                        &conf, 0, 0,
                                        &kadm_handle);
    if (ret)
        krb5_err (context, 1, ret, "kadm5_init_with_password_ctx");

    server_context = (kadm5_server_context *)kadm_handle;

    ret = kadm5_log_init (server_context);
    if (ret)
        krb5_err (context, 1, ret, "kadm5_log_init");

    get_creds(context, keytab_str, &ccache, master);

    ret = krb5_sname_to_principal (context, master, IPROP_NAME,
                                   KRB5_NT_SRV_HST, &server);
    if (ret)
        krb5_err (context, 1, ret, "krb5_sname_to_principal");

    auth_context = NULL;
    master_fd = -1;

    krb5_appdefault_time(context, config_name, NULL, "reconnect-min",
                         10, &reconnect_min);
    krb5_appdefault_time(context, config_name, NULL, "reconnect-max",
                         300, &reconnect_max);
    krb5_appdefault_time(context, config_name, NULL, "reconnect-backoff",
                         10, &backoff);
    reconnect = reconnect_min;

    while (!exit_flag) {
        time_t now, elapsed;
        int connected = FALSE;

        now = time(NULL);
        elapsed = now - before;

        if (elapsed < reconnect) {
            time_t left = reconnect - elapsed;
            krb5_warnx(context, "sleeping %d seconds before "
                       "retrying to connect", (int)left);
            sleep(left);
        }
        before = now;

        master_fd = connect_to_master (context, master, port_str);
        if (master_fd < 0)
            goto retry;

        reconnect = reconnect_min;

        if (auth_context) {
            krb5_auth_con_free(context, auth_context);
            auth_context = NULL;
            krb5_cc_destroy(context, ccache);
            get_creds(context, keytab_str, &ccache, master);
        }
        ret = krb5_sendauth (context, &auth_context, &master_fd,
                             IPROP_VERSION, NULL, server,
                             AP_OPTS_MUTUAL_REQUIRED, NULL, NULL,
                             ccache, NULL, NULL, NULL);
        if (ret) {
            krb5_warn (context, ret, "krb5_sendauth");
            goto retry;
        }

        krb5_warnx(context, "ipropd-slave started at version: %ld",
                   (long)server_context->log_context.version);

        ret = ihave (context, auth_context, master_fd,
                     server_context->log_context.version);
        if (ret)
            goto retry;

        connected = TRUE;

        while (connected && !exit_flag) {
            krb5_data out;
            krb5_storage *sp;
            int32_t tmp;
            fd_set readset;
            struct timeval to;

#ifndef NO_LIMIT_FD_SETSIZE
            if (master_fd >= FD_SETSIZE)
                krb5_errx (context, 1, "fd too large");
#endif

            FD_ZERO(&readset);
            FD_SET(master_fd, &readset);

            to.tv_sec = time_before_lost;
            to.tv_usec = 0;

            ret = select (master_fd + 1,
                          &readset, NULL, NULL, &to);
            if (ret < 0) {
                if (errno == EINTR)
                    continue;
                else
                    krb5_err (context, 1, errno, "select");
            }
            if (ret == 0)
                krb5_errx (context, 1, "server didn't send a message "
                           "in %d seconds", time_before_lost);

            ret = krb5_read_priv_message(context, auth_context, &master_fd, &out);
            if (ret) {
                krb5_warn (context, ret, "krb5_read_priv_message");
                connected = FALSE;
                continue;
            }

            sp = krb5_storage_from_mem (out.data, out.length);
            krb5_ret_int32 (sp, &tmp);
            switch (tmp) {
            case FOR_YOU :
                receive (context, sp, server_context);
                ret = ihave (context, auth_context, master_fd,
                             server_context->log_context.version);
                if (ret)
                    connected = FALSE;
                break;
            case TELL_YOU_EVERYTHING :
                ret = receive_everything (context, master_fd, server_context,
                                          auth_context);
                if (ret)
                    connected = FALSE;
                break;
            case ARE_YOU_THERE :
                send_im_here (context, master_fd, auth_context);
                break;
            case NOW_YOU_HAVE :
            case I_HAVE :
            case ONE_PRINC :
            case I_AM_HERE :
            default :
                krb5_warnx (context, "Ignoring command %d", tmp);
                break;
            }
            krb5_storage_free (sp);
            krb5_data_free (&out);

        }
    retry:
        if (connected == FALSE)
            krb5_warnx (context, "disconnected for server");
        if (exit_flag)
            krb5_warnx (context, "got an exit signal");

        if (master_fd >= 0)
            close(master_fd);

        reconnect += backoff;
        if (reconnect > reconnect_max)
            reconnect = reconnect_max;
    }

    if (0);
#ifndef NO_SIGXCPU
    else if(exit_flag == SIGXCPU)
        krb5_warnx(context, "%s CPU time limit exceeded", getprogname());
#endif
    else if(exit_flag == SIGINT || exit_flag == SIGTERM)
        krb5_warnx(context, "%s terminated", getprogname());
    else
        krb5_warnx(context, "%s unexpected exit reason: %ld",
                       getprogname(), (long)exit_flag);

    return 0;
}