/* libdhcp_control.h
 *
 *  DHCP client control API for libdhcp, a minimal interface to the
 *  ISC dhcp IPv4 client libdhcp4client library,
 *  and to the dhcpv6 DHCPv6 client libdhcp6client library.
 *
 *  Each DHCP client library must include this file to be controlled
 *  by libdhcp.
 *
 *  Copyright(C) Jason Vas Dias <jvdias@redhat.com> Red Hat Inc. May 2006
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation at 
 *           http://www.fsf.org/licensing/licenses/gpl.txt
 *  and included in this software distribution as the "LICENSE" file.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 */
#ifndef LIBDHCP_CONTROL_H
#define LIBDHCP_CONTROL_H

#include <stdint.h>

#define  LOG_FATAL 8

typedef enum dhcp_state_e {
    /* DHCPv4 client states
     * third callback arg will be a 'struct client_state *'
     */
    DHC4_NBI,     /* failed: no broadcast interfaces found              */
    DHC4_PREINIT, /* configuration started - bring the interface "UP"   */
    DHC4_BOUND,   /* lease obtained                                     */
    DHC4_RENEW,   /* lease renewed                                      */
    DHC4_REBOOT,  /* have valid lease, but now obtained a different one */
    DHC4_REBIND,  /* new, different lease                               */
    DHC4_STOP,    /* remove old lease                                   */
    DHC4_MEDIUM,  /* media selection begun                              */
    DHC4_TIMEOUT, /* timed out contacting DHCP server                   */
    DHC4_FAIL,    /* all attempts to contact server timed out, sleeping */
    DHC4_EXPIRE,  /* lease has expired, renewing                        */
    DHC4_RELEASE, /* releasing lease                                    */

    /* This state raised by both clients: */
    DHC_TIMEDOUT, /* libdhcp_control timeout has been exceeded          */

    /* DHCPv6 client states:    */
    DHC6_BOUND,   /* new lease obtained             - arg is optinfo *  */
    DHC6_REBIND,  /* existing expired lease rebound - arg is optinfo *  */
    DHC6_RELEASE  /* existing lease expired         - arg is dhcp6_iaidaddr*/
} DHCP_State;

struct libdhcp_control_s;

/* ala syslog(3): LOG_EMERG=0 - LOG_DEBUG=7 (+ LOG_FATAL=8 : finished -> 1) */
typedef int (*LIBDHCP_Error_Handler) (struct libdhcp_control_s *ctl,
                                      int priority, const char *fmt,
                                      va_list ap);

/* The DHCP clients will call the users' callback on important state change
 * events, with the second arg set to the client DHCP_State, and the third
 * arg set to a client specific pointer as described below. */
typedef int (*LIBDHCP_Callback) (struct libdhcp_control_s *control,
                                 enum dhcp_state_e, void*);

typedef struct libdhcp_control_s {
    /* the DHCP clients' main loop calls this on state changes */
    LIBDHCP_Callback callback;

    /* LIBDHCP_Capability bits to enable */
    uint16_t capability;

    /* set to one to make clients exit their main loop */
    uint8_t finished;

    /* set to one to decline the lease (DHCPv4 only) */
    uint8_t decline;

    /* (timeout+now) == time after which clients MUST return */
    time_t timeout;

    /* clients set this to time(0) on entering main loop */
    time_t now;

    /* user data pointer */
    void *arg;
    LIBDHCP_Error_Handler eh;
} LIBDHCP_Control;

/* DHCP client "capabilities" */
typedef enum libdhcp_capability_e {
    /* use / do not use persistent lease database files */
    DHCP_USE_LEASE_DATABASE = 1,

    /* use / do not use pid file */
    DHCP_USE_PID_FILE = 2,

    /*
     * DHCPv6 supports these capabilities in process, 
     * while the DHCPv4 client will fork and exec the dhclient-script to
     * implement them if these bits are set - otherwise, if no bits are set,
     * the callback is called and the script is not run.
     */
    /* configure interfaces UP/DOWN as required */
    DHCP_CONFIGURE_INTERFACES = 4,

    /* configure interface addresses as required */
    DHCP_CONFIGURE_ADDRESSES = 8,

    /* configure routes as required */
    DHCP_CONFIGURE_ROUTES = 16,

    /* configure resolv.conf as required */
    DHCP_CONFIGURE_RESOLVER = 32,

    /* DHCPv6 only: */
    /* configure radvd.conf & restart radvd as required */
    DHCP_CONFIGURE_RADVD = 64,
} LIBDHCP_Capability;

#endif