dhcp-server-conf.c

this is sample about DHCP-agent

/* $Header: /cvsroot/dhcp-agent/dhcp-agent/src/dhcp-server-conf.c,v 1.8 2003/07/15 10:56:34 actmodern Exp $
 * 
 * Copyright 2002 Thamer Alharbash <[e-mail]>
 * 
 * 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. The names of the authors may not be used to endorse or promote
 * products derived from this software without specific prior
 * written permission.
 * 
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 * 
 */

#define MODULE_NAME "dhcp-server-conf"

#include "dhcp-local.h"
#include "dhcp-limits.h"
#include "dhcp-libutil.h"
#include "dhcp-librawnet.h"
#include "dhcp-option.h"
#include "dhcp-lease.h"

#include "dhcp-conf.h"
#include "dhcp-conf-var.h"
#include "dhcp-server-conf.h"
#include "dhcp-server-defaults.h"
#include "dhcp-options-strings.h"

static const char *var_strings[] = {
    "default-renew-percent",
    "default-rebind-percent",
    "poll-timeout"
};

static const arg_symbol_t var_symbols[] = {
    SERVER_VAR_RENEW_PERCENT,
    SERVER_VAR_REBIND_PERCENT,
    SERVER_VAR_POLL_TIMEOUT,
};

static const arg_type_t     var_arg_types[] = { CONF_IDENTIFIER, CONF_ASSIGNMENT, CONF_STRING };
static const char         **var_arg_strings[] = { var_strings, NULL, NULL };
static const arg_symbol_t  *var_arg_symbols[] = { var_symbols, NULL, NULL };

static const arg_type_t     range_lease_arg_types[] = {  CONF_ADDRESS, CONF_ADDRESS, CONF_GROUP};
static const char         **range_lease_arg_strings[] = { NULL, NULL, NULL };
static const arg_symbol_t  *range_lease_arg_symbols[] = { NULL, NULL, NULL };

static const arg_type_t     hostname_lease_arg_types[] = {  CONF_STRING, CONF_ADDRESS, CONF_GROUP};
static const char         **hostname_lease_arg_strings[] = { NULL, NULL, NULL };
static const arg_symbol_t  *hostname_lease_arg_symbols[] = { NULL, NULL, NULL };

static const arg_type_t     mac_lease_arg_types[] = {  CONF_MAC_ADDRESS, CONF_ADDRESS, CONF_GROUP};
static const char         **mac_lease_arg_strings[] = { NULL, NULL, NULL };
static const arg_symbol_t  *mac_lease_arg_symbols[] = { NULL, NULL, NULL };

static const arg_type_t     option_arg_types[] = {  CONF_STRING, CONF_ASSIGNMENT, CONF_STRING_LIST };
static const char         **option_arg_strings[] = { NULL, NULL, NULL };
static const arg_symbol_t  *option_arg_symbols[] = { NULL, NULL, NULL };

/* command structures. */

/* set command. */
static const command_t command_set = {
    DIRECTIVE_SET,
    "set",
    3,
    var_arg_strings,
    var_arg_types,
    var_arg_symbols,
};

/* range-lease command. */
static const command_t command_range_lease = {
    DIRECTIVE_RANGE_LEASE,
    "range-lease",
    3,
    range_lease_arg_strings,
    range_lease_arg_types,
    range_lease_arg_symbols,
};

/* hostname-lease command. */
static const command_t command_hostname_lease = {
    DIRECTIVE_HOSTNAME_LEASE,
    "hostname-lease",
    3,
    hostname_lease_arg_strings,
    hostname_lease_arg_types,
    hostname_lease_arg_symbols,
};

/* mac-lease command. */
static const command_t command_mac_lease = {
    DIRECTIVE_MAC_LEASE,
    "mac-lease",
    3,
    mac_lease_arg_strings,
    mac_lease_arg_types,
    mac_lease_arg_symbols,
};

static const command_t command_option = {
    DIRECTIVE_OPTION,
    "option",
    3,
    option_arg_strings,
    option_arg_types,
    option_arg_symbols,
};

static const command_t *commands[] = {
    &command_set,
    &command_range_lease,
    &command_hostname_lease,
    &command_mac_lease,
    &command_option,
    NULL,
};

/* forward declaration of directive handlers. */

static int directive_set_handler(server_conf_t *server_conf, directive_t *directive, int group_type, void *group_data);
static int directive_range_handler(server_conf_t *server_conf, directive_t *directive, int group_type, void *group_data);
static int directive_option_handler(server_conf_t *server_conf, directive_t *directive, int group_type, void *group_data);
static int directive_hostname_handler(server_conf_t *server_conf, directive_t *directive, int group_type, void *group_data);
static int directive_hw_address_handler(server_conf_t *server_conf, directive_t *directive, int group_type, void *group_data);

/* indexed by directive types in dhcp-client-conf.h . */
directive_handler_t directive_handlers[] = {
    directive_set_handler,
    directive_range_handler,
    directive_hostname_handler,
    directive_hw_address_handler,
    directive_option_handler,
};

/* accessors. */

uint16_t server_conf_get_poll_timeout(server_conf_t *sc)
{
    return sc->poll_timeout;
}


/* * * * * * * * * * *
 * utility routines. *
 * * * * * * * * * * */

/* get name of configuration file for server. */
static char *get_conf_options_fname(const char *interface)
{
    char *fname;
    stringbuffer_t *sb;

    sb = stringbuffer_create();
    stringbuffer_aprintf(sb, "%s/default.conf", DHCPSYSCONF_SERVERDIR);

    if(file_exists(stringbuffer_getstring(sb))) {

        fname = xstrdup(stringbuffer_getstring(sb));
        stringbuffer_destroy(sb);
        return fname;

    }

    stringbuffer_clear(sb);
    stringbuffer_aprintf(sb, "%s/%s.conf", DHCPSYSCONF_SERVERDIR, interface);

    if(file_exists(stringbuffer_getstring(sb))) {

        fname = xstrdup(stringbuffer_getstring(sb));
        stringbuffer_destroy(sb);
        return fname;

    }

    /* otherwise there is no configuration file and this is
     * bad. signal a fatal error. */

    FATAL_MESSAGE("configuration file missing -- looked for default.conf and <interface>.conf. exiting...");
    exit(1); /* get rid of compiler warning. */
}

/* set variable. */
static int server_conf_set_variable(server_conf_t *server_conf, arg_symbol_t var_symbol, const char *var_value)
{
    switch(var_symbol) {

    case SERVER_VAR_RENEW_PERCENT:

        if(!is_unsigned_numeric(var_value))  {
            ERROR_MESSAGE("value not unsigned numeric as expected : %s\n", var_value);
            return 1;
        }

        sscanf(var_value, "%"SCNu16, &server_conf->default_renew_percent);

        if(server_conf->default_renew_percent > 100) { /* check if the percent is higher than it should be. */
            FATAL_MESSAGE("value specified for default-renew-percent is an illegal percent (over 100)");
        }

        break;

    case SERVER_VAR_REBIND_PERCENT:

        if(!is_unsigned_numeric(var_value))  {
            ERROR_MESSAGE("value not unsigned numeric as expected : %s", var_value);
            return 1;
        }

        sscanf(var_value, "%"SCNu16, &server_conf->default_rebind_percent);

        if(server_conf->default_renew_percent > 100) { /* check if the percent is higher than it should be. */
            FATAL_MESSAGE("value specified for default-rebind-percent is an illegal percent (over 100)");
        }

        break;

    case SERVER_VAR_POLL_TIMEOUT:

        if(!is_unsigned_numeric(var_value))  {
            ERROR_MESSAGE("value not unsigned numeric as expected : %s\n", var_value);
            return 1;
        }

        sscanf(var_value, "%"SCNu16, &server_conf->poll_timeout);
        break;

    default:
        
        ERROR_MESSAGE("unable to understand assignment value of : %s", var_value);
        return 1;
    }

    return 0;
}

/* load server options. */
static int server_conf_load_options(server_conf_t *sc)
{
    conf_t *conf;
    list_t *directives;
    directive_t *directive;

    conf = conf_create(commands, sc->conf_file);

    if(conf_compile_directives(conf) == CONF_ERROR) {
        ERROR_MESSAGE("error reading conf file: %s at line %d", sc->conf_file, conf_get_line_no(conf));
        conf_destroy(conf);