/*
 * 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"
#include <rtbl.h>

static krb5_log_facility *log_facility;

const char *slave_stats_file;
const char *slave_time_missing = "2 min";
const char *slave_time_gone = "5 min";

static int time_before_missing;
static int time_before_gone;

const char *master_hostname;

static krb5_socket_t
make_signal_socket (krb5_context context)
{
#ifndef NO_UNIX_SOCKETS
    struct sockaddr_un addr;
    const char *fn;
    krb5_socket_t fd;

    fn = kadm5_log_signal_socket(context);

    fd = socket (AF_UNIX, SOCK_DGRAM, 0);
    if (fd < 0)
        krb5_err (context, 1, errno, "socket AF_UNIX");
    memset (&addr, 0, sizeof(addr));
    addr.sun_family = AF_UNIX;
    strlcpy (addr.sun_path, fn, sizeof(addr.sun_path));
    unlink (addr.sun_path);
    if (bind (fd, (struct sockaddr *)&addr, sizeof(addr)) < 0)
        krb5_err (context, 1, errno, "bind %s", addr.sun_path);
    return fd;
#else
    struct addrinfo *ai = NULL;
    krb5_socket_t fd;

    kadm5_log_signal_socket_info(context, 1, &ai);

    fd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
    if (rk_IS_BAD_SOCKET(fd))
        krb5_err (context, 1, rk_SOCK_ERRNO, "socket AF=%d", ai->ai_family);

    if (rk_IS_SOCKET_ERROR( bind (fd, ai->ai_addr, ai->ai_addrlen) ))
        krb5_err (context, 1, rk_SOCK_ERRNO, "bind");
    return fd;
#endif
}

static krb5_socket_t
make_listen_socket (krb5_context context, const char *port_str)
{
    krb5_socket_t fd;
    int one = 1;
    struct sockaddr_in addr;

    fd = socket (AF_INET, SOCK_STREAM, 0);
    if (rk_IS_BAD_SOCKET(fd))
        krb5_err (context, 1, rk_SOCK_ERRNO, "socket AF_INET");
    setsockopt (fd, SOL_SOCKET, SO_REUSEADDR, (void *)&one, sizeof(one));
    memset (&addr, 0, sizeof(addr));
    addr.sin_family = AF_INET;

    if (port_str) {
        addr.sin_port = krb5_getportbyname (context,
                                              port_str, "tcp",
                                              0);
        if (addr.sin_port == 0) {
            char *ptr;
            long port;

            port = strtol (port_str, &ptr, 10);
            if (port == 0 && ptr == port_str)
                krb5_errx (context, 1, "bad port `%s'", port_str);
            addr.sin_port = htons(port);
        }
    } else {
        addr.sin_port = krb5_getportbyname (context, IPROP_SERVICE,
                                            "tcp", IPROP_PORT);
    }
    if(bind(fd, (struct sockaddr *)&addr, sizeof(addr)) < 0)
        krb5_err (context, 1, errno, "bind");
    if (listen(fd, SOMAXCONN) < 0)
        krb5_err (context, 1, errno, "listen");
    return fd;
}

static krb5_socket_t
make_listen6_socket (krb5_context context, const char *port_str)
{
    krb5_socket_t fd;
    int one = 1;
    struct sockaddr_in6 addr;

    fd = socket (AF_INET6, SOCK_STREAM, 0);
    if (rk_IS_BAD_SOCKET(fd))
        krb5_err (context, 1, rk_SOCK_ERRNO, "socket AF_INET6");
    setsockopt (fd, SOL_SOCKET, SO_REUSEADDR, (void *)&one, sizeof(one));
    memset (&addr, 0, sizeof(addr));
    addr.sin6_family = AF_INET6;

    if (port_str) {
        addr.sin6_port = krb5_getportbyname (context,
                                              port_str, "tcp",
                                              0);
        if (addr.sin6_port == 0) {
            char *ptr;
            long port;

            port = strtol (port_str, &ptr, 10);
            if (port == 0 && ptr == port_str)
                krb5_errx (context, 1, "bad port `%s'", port_str);
            addr.sin6_port = htons(port);
        }
    } else {
        addr.sin6_port = krb5_getportbyname (context, IPROP_SERVICE,
                                            "tcp", IPROP_PORT);
    }
    if(bind(fd, (struct sockaddr *)&addr, sizeof(addr)) < 0)
        krb5_err (context, 1, errno, "bind6");
    if (listen(fd, SOMAXCONN) < 0)
        krb5_err (context, 1, errno, "listen6");
    return fd;
}

#ifndef _SOCKADDR_UNION
#define _SOCKADDR_UNION
union sockaddr_union {
        struct sockaddr         sa;
        struct sockaddr_in      sin;
        struct sockaddr_in6     sin6;
};
#endif /* _SOCKADDR_UNION */

struct slave {
    krb5_socket_t fd;
    union sockaddr_union addr;
    char *name;
    krb5_auth_context ac;
    uint32_t version;
    time_t seen;
    unsigned long flags;
#define SLAVE_F_DEAD    0x1
#define SLAVE_F_AYT     0x2
    struct slave *next;
};

typedef struct slave slave;

static int
check_acl (krb5_context context, const char *name)
{
    const char *fn;
    FILE *fp;
    char buf[256];
    int ret = 1;
    char *slavefile = NULL;

    if (asprintf(&slavefile, "%s/slaves", hdb_db_dir(context)) == -1
        || slavefile == NULL)
        errx(1, "out of memory");

    fn = krb5_config_get_string_default(context,
                                        NULL,
                                        slavefile,
                                        "kdc",
                                        "iprop-acl",
                                        NULL);

    fp = fopen (fn, "r");
    free(slavefile);
    if (fp == NULL)
        return 1;
    while (fgets(buf, sizeof(buf), fp) != NULL) {
        buf[strcspn(buf, "\r\n")] = '\0';
        if (strcmp (buf, name) == 0) {
            ret = 0;
            break;
        }
    }
    fclose (fp);
    return ret;
}

static void
slave_seen(slave *s)
{
    s->flags &= ~SLAVE_F_AYT;
    s->seen = time(NULL);
}

static int
slave_missing_p (slave *s)
{
    if (time(NULL) > s->seen + time_before_missing)
        return 1;
    return 0;
}

static int
slave_gone_p (slave *s)
{
    if (time(NULL) > s->seen + time_before_gone)
        return 1;
    return 0;
}

static void
slave_dead(krb5_context context, slave *s)
{
    krb5_warnx(context, "slave %s dead", s->name);

    if (!rk_IS_BAD_SOCKET(s->fd)) {
        rk_closesocket (s->fd);
        s->fd = rk_INVALID_SOCKET;
    }
    s->flags |= SLAVE_F_DEAD;
    slave_seen(s);
}

static void
remove_slave (krb5_context context, slave *s, slave **root)
{
    slave **p;

    if (!rk_IS_BAD_SOCKET(s->fd))
        rk_closesocket (s->fd);
    if (s->name)
        free (s->name);
    if (s->ac)
        krb5_auth_con_free (context, s->ac);

    for (p = root; *p; p = &(*p)->next)
        if (*p == s) {
            *p = s->next;
            break;
        }
    free (s);
}

static void
add_slave (krb5_context context, krb5_keytab keytab, slave **root,
           krb5_socket_t fd)
{
    krb5_principal server;
    krb5_error_code ret;
    slave *s;
    socklen_t addr_len;
    krb5_ticket *ticket = NULL;
    char hostname[128];

    s = malloc(sizeof(*s));
    if (s == NULL) {
        krb5_warnx (context, "add_slave: no memory");
        return;
    }
    s->name = NULL;
    s->ac = NULL;

    addr_len = sizeof(s->addr.sin6);
    s->fd = accept (fd, (struct sockaddr *)&s->addr.sa, &addr_len);
    if (rk_IS_BAD_SOCKET(s->fd)) {
        krb5_warn (context, rk_SOCK_ERRNO, "accept");
        goto error;
    }
    if (master_hostname)
        strlcpy(hostname, master_hostname, sizeof(hostname));
    else
        gethostname(hostname, sizeof(hostname));

    ret = krb5_sname_to_principal (context, hostname, IPROP_NAME,
                                   KRB5_NT_SRV_HST, &server);
    if (ret) {
        krb5_warn (context, ret, "krb5_sname_to_principal");
        goto error;
    }

    ret = krb5_recvauth (context, &s->ac, &s->fd,
                         IPROP_VERSION, server, 0, keytab, &ticket);
    krb5_free_principal (context, server);
    if (ret) {
        krb5_warn (context, ret, "krb5_recvauth");
        goto error;
    }
    ret = krb5_unparse_name (context, ticket->client, &s->name);
    krb5_free_ticket (context, ticket);
    if (ret) {
        krb5_warn (context, ret, "krb5_unparse_name");
        goto error;
    }
    if (check_acl (context, s->name)) {
        krb5_warnx (context, "%s not in acl", s->name);
        goto error;
    }

    {
        slave *l = *root;

        while (l) {
            if (strcmp(l->name, s->name) == 0)
                break;
            l = l->next;
        }
        if (l) {
            if (l->flags & SLAVE_F_DEAD) {
                remove_slave(context, l, root);
            } else {
                krb5_warnx (context, "second connection from %s", s->name);
                goto error;
            }
        }
    }

    krb5_warnx (context, "connection from %s", s->name);

    s->version = 0;
    s->flags = 0;
    slave_seen(s);
    s->next = *root;
    *root = s;
    return;
error:
    remove_slave(context, s, root);
}

struct prop_context {
    krb5_auth_context auth_context;
    krb5_socket_t fd;
};

static int
prop_one (krb5_context context, HDB *db, hdb_entry_ex *entry, void *v)
{
    krb5_error_code ret;
    krb5_storage *sp;
    krb5_data data;
    struct slave *s = (struct slave *)v;

    ret = hdb_entry2value (context, &entry->entry, &data);
    if (ret)
        return ret;
    ret = krb5_data_realloc (&data, data.length + 4);
    if (ret) {
        krb5_data_free (&data);
        return ret;
    }
    memmove ((char *)data.data + 4, data.data, data.length - 4);
    sp = krb5_storage_from_data(&data);
    if (sp == NULL) {
        krb5_data_free (&data);
        return ENOMEM;
    }
    krb5_store_int32(sp, ONE_PRINC);
    krb5_storage_free(sp);

    ret = krb5_write_priv_message (context, s->ac, &s->fd, &data);
    krb5_data_free (&data);
    return ret;
}

static int
send_complete (krb5_context context, slave *s,
               const char *database, uint32_t current_version)
{
    krb5_error_code ret;
    krb5_storage *sp;
    HDB *db;
    krb5_data data;
    char buf[8];

    ret = hdb_create (context, &db, database);
    if (ret)
        krb5_err (context, 1, ret, "hdb_create: %s", database);
    ret = db->hdb_open (context, db, O_RDONLY, 0);
    if (ret)
        krb5_err (context, 1, ret, "db->open");

    sp = krb5_storage_from_mem (buf, 4);
    if (sp == NULL)
        krb5_errx (context, 1, "krb5_storage_from_mem");
    krb5_store_int32 (sp, TELL_YOU_EVERYTHING);
    krb5_storage_free (sp);

    data.data   = buf;
    data.length = 4;

    ret = krb5_write_priv_message(context, s->ac, &s->fd, &data);

    if (ret) {
        krb5_warn (context, ret, "krb5_write_priv_message");
        slave_dead(context, s);
        return ret;
    }

    ret = hdb_foreach (context, db, HDB_F_ADMIN_DATA, prop_one, s);
    if (ret) {
        krb5_warn (context, ret, "hdb_foreach");
        slave_dead(context, s);
        return ret;
    }

    (*db->hdb_close)(context, db);
    (*db->hdb_destroy)(context, db);

    sp = krb5_storage_from_mem (buf, 8);
    if (sp == NULL)
        krb5_errx (context, 1, "krb5_storage_from_mem");
    krb5_store_int32 (sp, NOW_YOU_HAVE);
    krb5_store_int32 (sp, current_version);
    krb5_storage_free (sp);

    data.length = 8;

    s->version = current_version;

    ret = krb5_write_priv_message(context, s->ac, &s->fd, &data);
    if (ret) {
        slave_dead(context, s);
        krb5_warn (context, ret, "krb5_write_priv_message");
        return ret;
    }

    slave_seen(s);

    return 0;
}

static int
send_are_you_there (krb5_context context, slave *s)
{
    krb5_storage *sp;
    krb5_data data;
    char buf[4];
    int ret;

    if (s->flags & (SLAVE_F_DEAD|SLAVE_F_AYT))
        return 0;

    krb5_warnx(context, "slave %s missing, sending AYT", s->name);

    s->flags |= SLAVE_F_AYT;

    data.data = buf;
    data.length = 4;

    sp = krb5_storage_from_mem (buf, 4);
    if (sp == NULL) {
        krb5_warnx (context, "are_you_there: krb5_data_alloc");
        slave_dead(context, s);
        return 1;
    }
    krb5_store_int32 (sp, ARE_YOU_THERE);
    krb5_storage_free (sp);

    ret = krb5_write_priv_message(context, s->ac, &s->fd, &data);

    if (ret) {
        krb5_warn (context, ret, "are_you_there: krb5_write_priv_message");
        slave_dead(context, s);
        return 1;
    }

    return 0;
}

static int
send_diffs (krb5_context context, slave *s, int log_fd,
            const char *database, uint32_t current_version)
{
    krb5_storage *sp;
    uint32_t ver;
    time_t timestamp;
    enum kadm_ops op;
    uint32_t len;
    off_t right, left;
    krb5_data data;
    int ret = 0;

    if (s->version == current_version) {
        krb5_warnx(context, "slave %s in sync already at version %ld",
                   s->name, (long)s->version);
        return 0;
    }

    if (s->flags & SLAVE_F_DEAD)
        return 0;

    /* if slave is a fresh client, starting over */
    if (s->version == 0) {
        krb5_warnx(context, "sending complete log to fresh slave %s",
                   s->name);
        return send_complete (context, s, database, current_version);
    }

    sp = kadm5_log_goto_end (log_fd);
    right = krb5_storage_seek(sp, 0, SEEK_CUR);
    for (;;) {
        ret = kadm5_log_previous (context, sp, &ver, &timestamp, &op, &len);
        if (ret)
            krb5_err(context, 1, ret,
                     "send_diffs: failed to find previous entry");
        left = krb5_storage_seek(sp, -16, SEEK_CUR);
        if (ver == s->version)
            return 0;
        if (ver == s->version + 1)
            break;
        if (left == 0) {
            krb5_storage_free(sp);
            krb5_warnx(context,
                       "slave %s (version %lu) out of sync with master "
                       "(first version in log %lu), sending complete database",
                       s->name, (unsigned long)s->version, (unsigned long)ver);
            return send_complete (context, s, database, current_version);
        }
    }

    krb5_warnx(context,
               "syncing slave %s from version %lu to version %lu",
               s->name, (unsigned long)s->version,
               (unsigned long)current_version);

    ret = krb5_data_alloc (&data, right - left + 4);
    if (ret) {
        krb5_storage_free(sp);
        krb5_warn (context, ret, "send_diffs: krb5_data_alloc");
        slave_dead(context, s);
        return 1;
    }
    krb5_storage_read (sp, (char *)data.data + 4, data.length - 4);
    krb5_storage_free(sp);

    sp = krb5_storage_from_data (&data);
    if (sp == NULL) {
        krb5_warnx (context, "send_diffs: krb5_storage_from_data");
        slave_dead(context, s);
        return 1;
    }
    krb5_store_int32 (sp, FOR_YOU);
    krb5_storage_free(sp);

    ret = krb5_write_priv_message(context, s->ac, &s->fd, &data);
    krb5_data_free(&data);

    if (ret) {
        krb5_warn (context, ret, "send_diffs: krb5_write_priv_message");
        slave_dead(context, s);
        return 1;
    }
    slave_seen(s);

    s->version = current_version;

    return 0;
}

static int
process_msg (krb5_context context, slave *s, int log_fd,
             const char *database, uint32_t current_version)
{
    int ret = 0;
    krb5_data out;
    krb5_storage *sp;
    int32_t tmp;

    ret = krb5_read_priv_message(context, s->ac, &s->fd, &out);
    if(ret) {
        krb5_warn (context, ret, "error reading message from %s", s->name);
        return 1;
    }

    sp = krb5_storage_from_mem (out.data, out.length);
    if (sp == NULL) {
        krb5_warnx (context, "process_msg: no memory");
        krb5_data_free (&out);
        return 1;
    }
    if (krb5_ret_int32 (sp, &tmp) != 0) {
        krb5_warnx (context, "process_msg: client send too short command");
        krb5_data_free (&out);
        return 1;
    }
    switch (tmp) {
    case I_HAVE :
        ret = krb5_ret_int32 (sp, &tmp);
        if (ret != 0) {
            krb5_warnx (context, "process_msg: client send too I_HAVE data");
            break;
        }
        /* new started slave that have old log */
        if (s->version == 0 && tmp != 0) {
            if (current_version < (uint32_t)tmp) {
                krb5_warnx (context, "Slave %s (version %lu) have later version "
                            "the master (version %lu) OUT OF SYNC",
                            s->name, (unsigned long)tmp,
                            (unsigned long)current_version);
            }
            s->version = tmp;
        }
        if ((uint32_t)tmp < s->version) {
            krb5_warnx (context, "Slave claims to not have "
                        "version we already sent to it");
        } else {
            ret = send_diffs (context, s, log_fd, database, current_version);
        }
        break;
    case I_AM_HERE :
        break;
    case ARE_YOU_THERE:
    case FOR_YOU :
    default :
        krb5_warnx (context, "Ignoring command %d", tmp);
        break;
    }

    krb5_data_free (&out);
    krb5_storage_free (sp);

    slave_seen(s);

    return ret;
}

#define SLAVE_NAME      "Name"
#define SLAVE_ADDRESS   "Address"
#define SLAVE_VERSION   "Version"
#define SLAVE_STATUS    "Status"
#define SLAVE_SEEN      "Last Seen"

static FILE *
open_stats(krb5_context context)
{
    char *statfile = NULL;
    const char *fn;
    FILE *f;

    if (slave_stats_file)
        fn = slave_stats_file;
    else {
        asprintf(&statfile,  "%s/slaves-stats", hdb_db_dir(context));
        fn = krb5_config_get_string_default(context,
                                            NULL,
                                            statfile,
                                            "kdc",
                                            "iprop-stats",
                                            NULL);
    }
    f = fopen(fn, "w");
    if (statfile)
        free(statfile);

    return f;
}

static void
write_master_down(krb5_context context)
{
    char str[100];
    time_t t = time(NULL);
    FILE *fp;

    fp = open_stats(context);
    if (fp == NULL)
        return;
    krb5_format_time(context, t, str, sizeof(str), TRUE);
    fprintf(fp, "master down at %s\n", str);

    fclose(fp);
}

static void
write_stats(krb5_context context, slave *slaves, uint32_t current_version)
{
    char str[100];
    rtbl_t tbl;
    time_t t = time(NULL);
    FILE *fp;

    fp = open_stats(context);
    if (fp == NULL)
        return;

    krb5_format_time(context, t, str, sizeof(str), TRUE);
    fprintf(fp, "Status for slaves, last updated: %s\n\n", str);

    fprintf(fp, "Master version: %lu\n\n", (unsigned long)current_version);

    tbl = rtbl_create();
    if (tbl == NULL) {
        fclose(fp);
        return;
    }

    rtbl_add_column(tbl, SLAVE_NAME, 0);
    rtbl_add_column(tbl, SLAVE_ADDRESS, 0);
    rtbl_add_column(tbl, SLAVE_VERSION, RTBL_ALIGN_RIGHT);
    rtbl_add_column(tbl, SLAVE_STATUS, 0);
    rtbl_add_column(tbl, SLAVE_SEEN, 0);

    rtbl_set_prefix(tbl, "  ");
    rtbl_set_column_prefix(tbl, SLAVE_NAME, "");

    while (slaves) {
        krb5_address addr;
        krb5_error_code ret;
        rtbl_add_column_entry(tbl, SLAVE_NAME, slaves->name);
        ret = krb5_sockaddr2address (context,
                                     (struct sockaddr*)&slaves->addr.sa, &addr);
        if(ret == 0) {
            krb5_print_address(&addr, str, sizeof(str), NULL);
            krb5_free_address(context, &addr);
            rtbl_add_column_entry(tbl, SLAVE_ADDRESS, str);
        } else
            rtbl_add_column_entry(tbl, SLAVE_ADDRESS, "<unknown>");

        snprintf(str, sizeof(str), "%u", (unsigned)slaves->version);
        rtbl_add_column_entry(tbl, SLAVE_VERSION, str);

        if (slaves->flags & SLAVE_F_DEAD)
            rtbl_add_column_entry(tbl, SLAVE_STATUS, "Down");
        else
            rtbl_add_column_entry(tbl, SLAVE_STATUS, "Up");

        ret = krb5_format_time(context, slaves->seen, str, sizeof(str), TRUE);
        if (ret)
            rtbl_add_column_entry(tbl, SLAVE_SEEN, "<error-formatting-time>");
        else
            rtbl_add_column_entry(tbl, SLAVE_SEEN, str);

        slaves = slaves->next;
    }

    rtbl_format(tbl, fp);
    rtbl_destroy(tbl);

    fclose(fp);
}


static char sHDB[] = "HDB:";
static char *realm;
static int version_flag;
static int help_flag;
static char *keytab_str = sHDB;
static char *database;
static char *config_file;
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" },
    { "database", 'd', arg_string, &database, "database", "file"},
    { "slave-stats-file", 0, arg_string, rk_UNCONST(&slave_stats_file),
      "file for slave status information", "file"},
    { "time-missing", 0, arg_string, rk_UNCONST(&slave_time_missing),
      "time before slave is polled for presence", "time"},
    { "time-gone", 0, arg_string, rk_UNCONST(&slave_time_gone),
      "time of inactivity after which a slave is considered gone", "time"},
    { "port", 0, arg_string, &port_str,
      "port ipropd will listen to", "port"},
#ifdef SUPPORT_DETACH
    { "detach", 0, arg_flag, &detach_from_console,
      "detach from console", NULL },
#endif
    { "hostname", 0, arg_string, rk_UNCONST(&master_hostname),
      "hostname of master (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]);

int
main(int argc, char **argv)
{
    krb5_error_code ret;
    krb5_context context;
    void *kadm_handle;
    kadm5_server_context *server_context;
    kadm5_config_params conf;
    krb5_socket_t signal_fd, listen_fd, listen6_fd;
    int log_fd;
    slave *slaves = NULL;
    uint32_t current_version = 0, old_version = 0;
    krb5_keytab keytab;
    int optidx;
    char **files;

    optidx = krb5_program_setup(&context, argc, argv, args, num_args, NULL);

    if(help_flag)
        krb5_std_usage(0, args, num_args);
    if(version_flag) {
        print_version(NULL);
        exit(0);
    }

    setup_signal();

    if (config_file == NULL) {
        asprintf(&config_file, "%s/kdc.conf", hdb_db_dir(context));
        if (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");

    time_before_gone = parse_time (slave_time_gone,  "s");
    if (time_before_gone < 0)
        krb5_errx (context, 1, "couldn't parse time: %s", slave_time_gone);
    time_before_missing = parse_time (slave_time_missing,  "s");
    if (time_before_missing < 0)
        krb5_errx (context, 1, "couldn't parse time: %s", slave_time_missing);

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

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

    memset(&conf, 0, sizeof(conf));
    if(realm) {
        conf.mask |= KADM5_CONFIG_REALM;
        conf.realm = realm;
    }
    ret = kadm5_init_with_skey_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;

    log_fd = open (server_context->log_context.log_file, O_RDONLY, 0);
    if (log_fd < 0)
        krb5_err (context, 1, errno, "open %s",
                  server_context->log_context.log_file);

    signal_fd = make_signal_socket (context);
    listen_fd = make_listen_socket (context, port_str);
    listen6_fd = make_listen6_socket (context, port_str);

    kadm5_log_get_version_fd (log_fd, &current_version);

    krb5_warnx(context, "ipropd-master started at version: %lu",
               (unsigned long)current_version);

    while(exit_flag == 0){
        slave *p;
        fd_set readset;
        int max_fd = 0;
        struct timeval to = {30, 0};
        uint32_t vers;

#ifndef NO_LIMIT_FD_SETSIZE
        if (signal_fd >= FD_SETSIZE || listen_fd >= FD_SETSIZE ||
            listen6_fd >= FD_SETSIZE)
            krb5_errx (context, 1, "fd too large");
#endif

        FD_ZERO(&readset);
        FD_SET(signal_fd, &readset);
        max_fd = max(max_fd, signal_fd);
        FD_SET(listen_fd, &readset);
        max_fd = max(max_fd, listen_fd);
        FD_SET(listen6_fd, &readset);
        max_fd = max(max_fd, listen6_fd);

        for (p = slaves; p != NULL; p = p->next) {
            if (p->flags & SLAVE_F_DEAD)
                continue;
            FD_SET(p->fd, &readset);
            max_fd = max(max_fd, p->fd);
        }

        ret = select (max_fd + 1,
                      &readset, NULL, NULL, &to);
        if (ret < 0) {
            if (errno == EINTR)
                continue;
            else
                krb5_err (context, 1, errno, "select");
        }

        if (ret == 0) {
            old_version = current_version;
            kadm5_log_get_version_fd (log_fd, &current_version);

            if (current_version > old_version) {
                krb5_warnx(context,
                           "Missed a signal, updating slaves %lu to %lu",
                           (unsigned long)old_version,
                           (unsigned long)current_version);
                for (p = slaves; p != NULL; p = p->next) {
                    if (p->flags & SLAVE_F_DEAD)
                        continue;
                    send_diffs (context, p, log_fd, database, current_version);
                }
            }
        }

        if (ret && FD_ISSET(signal_fd, &readset)) {
#ifndef NO_UNIX_SOCKETS
            struct sockaddr_un peer_addr;
#else
            struct sockaddr_storage peer_addr;
#endif
            socklen_t peer_len = sizeof(peer_addr);

            if(recvfrom(signal_fd, (void *)&vers, sizeof(vers), 0,
                        (struct sockaddr *)&peer_addr, &peer_len) < 0) {
                krb5_warn (context, errno, "recvfrom");
                continue;
            }
            --ret;
            assert(ret >= 0);
            old_version = current_version;
            kadm5_log_get_version_fd (log_fd, &current_version);
            if (current_version > old_version) {
                krb5_warnx(context,
                           "Got a signal, updating slaves %lu to %lu",
                           (unsigned long)old_version,
                           (unsigned long)current_version);
                for (p = slaves; p != NULL; p = p->next) {
                    if (p->flags & SLAVE_F_DEAD)
                        continue;
                    send_diffs (context, p, log_fd, database, current_version);
                }
            } else {
                krb5_warnx(context,
                           "Got a signal, but no update in log version %lu",
                           (unsigned long)current_version);
            }
        }

        for(p = slaves; p != NULL; p = p->next) {
            if (p->flags & SLAVE_F_DEAD)
                continue;
            if (ret && FD_ISSET(p->fd, &readset)) {
                --ret;
                assert(ret >= 0);
                if(process_msg (context, p, log_fd, database, current_version))
                    slave_dead(context, p);
            } else if (slave_gone_p (p))
                slave_dead(context, p);
            else if (slave_missing_p (p))
                send_are_you_there (context, p);
        }

        if (ret && FD_ISSET(listen6_fd, &readset)) {
            add_slave (context, keytab, &slaves, listen6_fd);
            --ret;
            assert(ret >= 0);
        }
        if (ret && FD_ISSET(listen_fd, &readset)) {
            add_slave (context, keytab, &slaves, listen_fd);
            --ret;
            assert(ret >= 0);
        }
        write_stats(context, slaves, current_version);
    }

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

    write_master_down(context);

    return 0;
}