dhcp-sysconf.c

来自「this is sample about DHCP-agent」· C语言 代码 · 共 241 行

/* $Header: /cvsroot/dhcp-agent/dhcp-agent/src/dhcp-sysconf.c,v 1.22 2003/06/27 20:59:17 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.
 * 
 */

/* Configure host internal structures. */

#define MODULE_NAME "dhcp-sysconf"

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

#include "dhcp-cache-entry.h"
#include "dhcp-client-cache.h"
#include "dhcp-client-conf.h"
#include "dhcp-client.h"
#include "dhcp-sysconf.h"
#include "dhcp-client-guile.h"

/* override, prepend, and append to options. */

/* do overrides. */
static void sysconf_override(list_t *options, list_t *overrides)
{
    dhcp_opt_t *orig, *override;

    /* walk down list and override where necessary.  since we're
    * overriding the options list and will be rewriting it we
    * need to loop on overrides in order to avoid looping
    * indefinetly. unfortunately this gives us the worest case
    * scenario in terms of cpu time. FIXME: write a
    * list_replace_datum routine */

    list_rewind(overrides);
    while((override = list_next(overrides)) != NULL) {

        list_rewind(options);
        while((orig = list_next(options)) != NULL) {

            if(dhcp_opt_get_tag(override) == dhcp_opt_get_tag(orig)) {

                list_remove_by_datum(options, orig);
                dhcp_opt_destroy(orig);

                list_add(options, dhcp_option_copy(override));
                break;
            }
        }
    }

    return;
}

static void sysconf_prepend_or_append_proc(list_t *options, list_t *add_options,
                                           void (*add)(dhcp_opt_t *orig, dhcp_opt_t *add))
{
    dhcp_opt_t *orig, *add_opt;

    /* walk down list and do addition where necessary. */
    list_rewind(options);
    while((orig = list_next(options)) != NULL) {

        list_rewind(add_options);
        while((add_opt = list_next(add_options)) != NULL) {

            if(dhcp_opt_get_tag(orig) == dhcp_opt_get_tag(add_opt)) {

                /* we already know that the conf code guarantees
                 * we're only dealing with list types. no need to
                 * double check here. */

                add(orig, add_opt);
                break;
            }
        }
    }

    return;
}

/* do prepends. */
static void sysconf_prepend(list_t *options, list_t *prepends)
{
    sysconf_prepend_or_append_proc(options, prepends, dhcp_option_prepend);
    return;
}

/* do appends. */
static void sysconf_append(list_t *options, list_t *appends)
{
    sysconf_prepend_or_append_proc(options, appends, dhcp_option_append);
    return;
}

/* * * * * * * * * * * *
 * Sysconf interface.  *
 * * * * * * * * * * * */

void do_sysconf(list_t *options, dhcp_client_control_t *dc, int state)
{
    list_t *overrides, *prepends, *appends;

    overrides = client_conf_get_override_options(dc->conf,
                                                 dhcp_client_get_server_ip_address(dc),
                                                 dhcp_client_get_server_hw_address(dc));

    sysconf_override(options, overrides);

    prepends = client_conf_get_append_options(dc->conf,
                                              dhcp_client_get_server_ip_address(dc),
                                              dhcp_client_get_server_hw_address(dc));
    sysconf_prepend(options, prepends);

    appends = client_conf_get_prepend_options(dc->conf,
                                              dhcp_client_get_server_ip_address(dc),
                                              dhcp_client_get_server_hw_address(dc));
    sysconf_append(options, appends);

                                                        
    return dhcp_sysconf_guile(dc, options, state);
}

/* setup timers only. this is done internally after rebinding,
 * renewing or acquiring a new lease. */

void do_sysconf_setup_timers(list_t *options, dhcp_client_control_t *dc)
{
    dhcp_opt_t *option;
    dhcp_opt_tag_t tag;
    uint32_t *secs;
    uint32_t renew_time = 0;
    uint32_t rebind_time = 0;
    uint32_t lease_time = 0;
    uint8_t have_renew = 0;
    uint8_t have_rebind = 0;
    uint8_t have_lease_time = 0;
    float percent;

    reinitialize_timer(dc->context->timer);

    list_rewind(options);
    while((option = list_next(options)) != NULL) {

        tag = dhcp_opt_get_tag(option);

        if(tag == TAG_DHCP_RENEWAL_TIME) {

            secs = dhcp_opt_get_host_data(option);
            have_renew = 1;
            renew_time = *secs;
            continue;

        } else if(tag == TAG_DHCP_REBINDING_TIME) {

            secs = dhcp_opt_get_host_data(option);
            have_rebind = 1;
            rebind_time = *secs;
            continue;

        } else if(tag == TAG_DHCP_IP_ADDRESS_LEASE_TIME) {

            secs = dhcp_opt_get_host_data(option);
            have_lease_time = 1;
            lease_time = *secs;
            continue;
        }
    }

    if(have_lease_time != 1) {

        /* we don't have an actual lease time.  check
         * configuration options on what we should do. */

        WARN_MESSAGE("no lease time passed. assuming lease will never expire.");
        lease_time = 0xffffffff;
    }

    /* a lease time of 0xffffffff is defined by the RFC2131 as infinite. */

    if(lease_time == INFINITE_TIME) {

        INFO_MESSAGE("setting infinite lease time.");
        dhcp_client_lease_time_is_infinite(dc);

    } else {

        dhcp_client_lease_time_is_finite(dc);
        INFO_MESSAGE("setting lease time to: %"PRIu32" seconds", lease_time);

        timer_add_trigger(dc->context->timer, lease_time, TIMER_IP_LEASE);

        if(!have_renew) {

            percent = (float)client_conf_get_renew_percent(dc->conf)/100;
            INFO_MESSAGE("no renew time passed. using %%%.2f percent of lease time as renew time.", percent);

            renew_time = lease_time * percent;

        }

        INFO_MESSAGE("setting renew time to: %"PRIu32" seconds", renew_time);
        timer_add_trigger(dc->context->timer, renew_time, TIMER_RENEW);

        if(!have_rebind) {

            percent = (float)client_conf_get_rebind_percent(dc->conf)/100;
            INFO_MESSAGE("no rebind time passed. using %%%.2f percent of lease time as rebind time.", percent);

            rebind_time = lease_time * percent;
        }

        INFO_MESSAGE("setting rebind time to: %"PRIu32" seconds", rebind_time);
        timer_add_trigger(dc->context->timer, rebind_time, TIMER_REBIND);
    }

    return;
}