/*
 ******************************************************************************
 *                     INTERPEAK SOURCE FILE
 *
 *   Document no: @(#) $Name: VXWORKS_ITER40_2019102207 $ $RCSfile: ipmip6ha_pmipv6_dhcpv4.c,v $ $Revision: 1.7 $
 *   $Source: /home/interpeak/CVSRoot/ipmip6ha/config/ipmip6ha_pmipv6_dhcpv4.c,v $
 *   $Author: jhorteli $
 *   $State: Exp $ $Locker:  $
 *
 *   INTERPEAK_COPYRIGHT_STRING
 *     Design and implementation by Joel Hortelius <joel.hortelis@interpeak.se>
 ******************************************************************************
 */


/*
 ****************************************************************************
 * 1                    DESCRIPTION
 ****************************************************************************
 */

/*
 ****************************************************************************
 * 2                    CONFIGURATION
 ****************************************************************************
 */

#include "ipmip6ha_config.h"

#if defined(IPMIP_USE_INET)

/*
 ****************************************************************************
 * 3                    INCLUDE FILES
 ****************************************************************************
 */

#define IPCOM_USE_CLIB_PROTO
#include <ipcom_clib.h>
#include <ipcom_err.h>
#include <ipcom_hash.h>
#include <ipcom_inet.h>
#include <ipcom_ipd.h>
#include <ipcom_list.h>
#include <ipcom_os.h>
#include <ipcom_sock.h>
#include <ipcom_sock2.h>
#include <ipcom_syslog.h>
#include <ipcom_sysvar.h>
#include <ipcom_strlib.h>

#include <ipmip.h>
#include <private/ipmip_sysvar.h>
#include <private/ipmip_dhcp.h>

#include <ipmip6.h>
#include <private/ipmip6_context.h>
#include <private/ipmip6_netlink.h>
#include <private/ipmip6_if.h>
#include <private/ipmip6_icmp.h>
#include <private/ipmip6_util.h>

#include "ipmip6ha_h.h"
#include "ipmip6ha_attr_h.h"
#include "ipmip6ha_if.h"
#include "ipmip6ha_node.h"
#include "ipmip6ha_pktbuf.h"
#include "ipmip6ha_nemo.h"
#include "ipmip6ha_nemo_dsmipv6.h"

/*
 ****************************************************************************
 * 4                    DEFINES
 ****************************************************************************
 */
#define IPMIP6HA_PMIPV6_DHCPV4_SERVER "DHCPV4-SERVER"

/*
 ****************************************************************************
 * 5                    TYPES
 ****************************************************************************
 */
typedef struct Ipmip6ha_pmipv6_dhcpv4_config
{
    Ip_bool         enabled;
} Ipmip6ha_pmipv6_dhcpv4_config_t;

typedef struct Ipmip6ha_pmipv6_dhcpv4_config_global
{
    Ip_bool         enabled;
} Ipmip6ha_pmipv6_dhcpv4_config_global_t;

typedef struct Ipmip6ha_pmipv6_dhcpv4_node
{
    Ipmip_dhcp_node_t               dhcp;
    Ip_bool                         installed;
} Ipmip6ha_pmipv6_dhcpv4_node_t;

/*
 ****************************************************************************
 * 6                    EXTERN PROTOTYPES
 ****************************************************************************
 */

/*
 ****************************************************************************
 * 7                    LOCAL PROTOTYPES
 ****************************************************************************
 */
/*
 ****************************************************************************
 * 8                    DATA
 ****************************************************************************
 */

/*
 ****************************************************************************
 * 9                    STATIC FUNCTIONS
 ****************************************************************************
 */
IP_STATIC int
ipmip6ha_pmipv6_dhcpv4_server(int                               event,
                              Ipmip6ha_context_t                *ctx,
                              Ipmip_proc_t                      *proc,
                              Ipmip6ha_pmipv6_dhcpv4_node_t     *dnode,
                              Ipmip6ha_pktbuf_t                 *pbuf)
{
    if (event == IPMIP_TIMER_EVENT_RUN)
    {
        Ipmip6ha_node_t     *node = dnode->dhcp.opaque;
        Ipmip_dhcp_hdr_t    *pkt  = (Ipmip_dhcp_hdr_t *)IPMIP_BUFFER_PTR(&pbuf->ipmip6.ipmip.packet);

        if (pkt->op == IPMIP_DHCP_OP_BOOTREQUEST)
        {
            Ip_u8                       *opt;

            /**/
            if ((opt = ipmip_dhcp_option_buffer_find(&pbuf->ipmip6.ipmip.packet, IPMIP_DHCP_OPTCODE_DHCP_MESSAGE_TYPE)) == IP_NULL)
            {
                IPMIP6_EVENT_IF(ERR, proc, 
                                ipmip_log_event_add(&ctx->ipmip6.ipmip, 
                                                    proc, 
                                                    "No MESSAGE TYPE in DHCP Request Received by %s",
                                                    ipmip6ha_node_describe(proc, node)));
                goto done_out;

            }
            else
            {
                Ipmip6ha_pktbuf_t   *rpkt = (Ipmip6ha_pktbuf_t*)ipmip_pktbuf_alloc(&ctx->ipmip6.ipmip, proc, 512);
                Ipmip_buffer_t      *buf = &rpkt->ipmip6.ipmip.packet;
                Ip_u8               type;
                Ip_u8               *ra_opt  = ipmip_dhcp_option_buffer_find(&pbuf->ipmip6.ipmip.packet, IPMIP_DHCP_OPTCODE_RELAY_AGENT_INFO);
                Ip_u8               *req_opt = ipmip_dhcp_option_buffer_find(&pbuf->ipmip6.ipmip.packet, IPMIP_DHCP_OPTCODE_DHCP_PARAMETER_REQUEST_LIST);
                Ip_u32              tmp32;
                Ip_u32              override = 0;


                /* Do we have a override option? */
                if (ra_opt)
                {
                    Ip_u8 *oopt = ipmip_dhcp_option_find(&ra_opt[IPMIP_DHCP_OPT_DATA], ra_opt[IPMIP_DHCP_OPT_LEN], IPMIP_DHCP_SUBOPTCODE_RA_SERVER_OVERRIDE);
                    if (oopt)
                        override = IP_GET_32ON8(&oopt[IPMIP_DHCP_OPT_DATA]);
                }

                /* Add the packet */
                ipmip_buffer_append(buf, pkt, sizeof(*pkt));


                switch(opt[IPMIP_DHCP_OPT_DATA])
                {
                case IPMIP_DHCP_MSG_DISCOVER:
                    IPMIP6_EVENT_IF(INFO, proc, 
                                    ipmip_log_event_add(&ctx->ipmip6.ipmip, 
                                                        proc, 
                                                        "DHCP Discover Received by %s",
                                                        ipmip6ha_node_describe(proc, node)));
                    type = IPMIP_DHCP_MSG_OFFER;
                    break;

                case IPMIP_DHCP_MSG_REQUEST:
                    {
                        Ip_u32  sid         = 0;
                        Ip_u32  req_addr    = 0;

                        IPMIP6_EVENT_IF(INFO, proc, 
                                        ipmip_log_event_add(&ctx->ipmip6.ipmip, 
                                                            proc, 
                                                            "DHCP Request Received by %s",
                                                            ipmip6ha_node_describe(proc, node)));

                        sid         = ipmip_dhcp_option_buffer_find_ip(&pbuf->ipmip6.ipmip.packet,
                                                                        IPMIP_DHCP_OPTCODE_DHCP_SERVER_IDENTIFIER);
                        req_addr    = ipmip_dhcp_option_buffer_find_ip(&pbuf->ipmip6.ipmip.packet,
                                                                        IPMIP_DHCP_OPTCODE_DHCP_REQUESTED_ADDRESS);

                        if (req_addr == 0)
                            req_addr = IP_GET_32ON8(&pkt->ciaddr);

                        if (sid != 0 && sid != node->ifp_home->ifaddr_v4)
                        {
                            if (override == 0 || sid != override)
                                goto done_out;
                        }

                        if (req_addr != 0 && req_addr == dnode->dhcp.remote_id)
                            type = IPMIP_DHCP_MSG_ACK;
                        else
                            type = IPMIP_DHCP_MSG_NAK;
                    }
                    break;
                case IPMIP_DHCP_MSG_DECLINE:
                    /* Do what? */
                    IPMIP6_EVENT_IF(INFO, proc, 
                                    ipmip_log_event_add(&ctx->ipmip6.ipmip, 
                                                        proc, 
                                                        "DHCP Decline Received by %s",
                                                        ipmip6ha_node_describe(proc, node)));
                    goto done_out;

                case IPMIP_DHCP_MSG_RELEASE:
                    /* Do what? */
                    IPMIP6_EVENT_IF(INFO, proc, 
                                    ipmip_log_event_add(&ctx->ipmip6.ipmip, 
                                                        proc, 
                                                        "DHCP Release Received by %s",
                                                        ipmip6ha_node_describe(proc, node)));
                    goto done_out;

                case IPMIP_DHCP_MSG_INFORM:
                    /* Do what? */
                    IPMIP6_EVENT_IF(INFO, proc, 
                                    ipmip_log_event_add(&ctx->ipmip6.ipmip, 
                                                        proc, 
                                                        "DHCP Inform Received by %s",
                                                        ipmip6ha_node_describe(proc, node)));
                    if (IP_GET_32ON8(&pkt->ciaddr) == dnode->dhcp.remote_id)
                        type = IPMIP_DHCP_MSG_INFORM_ACK;
                    else
                        type = IPMIP_DHCP_MSG_NAK;
                    break;
                default:
                    IPMIP6_EVENT_IF(INFO, proc, 
                                    ipmip_log_event_add(&ctx->ipmip6.ipmip, 
                                                        proc, 
                                                        "DHCP unknown Received by %s",
                                                        ipmip6ha_node_describe(proc, node)));
                    goto done_out;
                }

                /* Add TYPE */
                ipmip_dhcp_option_buffer_append_u8(buf, IPMIP_DHCP_OPTCODE_DHCP_MESSAGE_TYPE, type);
                ipmip_dhcp_option_buffer_append_ip(buf, IPMIP_DHCP_OPTCODE_DHCP_SERVER_IDENTIFIER, override? override : node->ifp_home->ifaddr_v4);

                /**/
                if (type != IPMIP_DHCP_MSG_NAK)
                {
                    /* ACK or INFORM_ACK */
                    if (type != IPMIP_DHCP_MSG_INFORM_ACK)
                    {
#ifndef IPTESTENGINE
                        ipmip_dhcp_option_buffer_append_u32(buf, IPMIP_DHCP_OPTCODE_DHCP_LEASE_TIME, node->mip6BindingCacheEntry.mip6BindingTimeRemaining);
#else
                        ipmip_dhcp_option_buffer_append_u32(buf, IPMIP_DHCP_OPTCODE_DHCP_LEASE_TIME, 5);
#endif
                    }

                    /* Add the basic options */
                    {
                        Ipmip6ha_nemo_dsmipv6_config_t *cfg = ipmip6ha_nemo_dsmipv6_subnet_config_get(ctx, proc, node->ifp_home->nemo->nemo_dsmipv6, dnode->dhcp.remote_id);
                        if (cfg != IP_NULL)
                        {
                            Ipmip6ha_nemo_dsmipv6_config_t *ncfg;
                            Ipmip_dhcp_option_t *dopt;

                            if (req_opt != IP_NULL)
                            {
                                for (tmp32 = 0; tmp32 < req_opt[IPMIP_DHCP_OPT_LEN]; tmp32++)
                                {
                                    for (ncfg = cfg; ncfg != IP_NULL; ncfg = ncfg->parent)
                                    {
                                        dopt = ipmip_dhcp_option_entry_find(&ncfg->opts, req_opt[IPMIP_DHCP_OPT_DATA + tmp32]);
                                        if (dopt != IP_NULL)
                                        {
                                            ipmip_dhcp_buffer_append_option_entry(buf, dopt);
                                            break;
                                        }
                                    }
                                }
                            }

                            for (ncfg = cfg; ncfg != IP_NULL; ncfg = ncfg->parent)
                            {
                                for (dopt = IPCOM_LIST_FIRST(&ncfg->opts); dopt != IP_NULL; dopt = IPCOM_LIST_NEXT(&dopt->next))
                                    ipmip_dhcp_buffer_append_option_entry(buf, dopt);
                            }
                        }
                    }
                }
                else
                {
                    /* NAK */
                }

                /* Restore the RA_OPT */
                if (ra_opt)
                    ipmip_dhcp_option_buffer_append(buf, IPMIP_DHCP_OPTCODE_RELAY_AGENT_INFO, ra_opt[IPMIP_DHCP_OPT_LEN], &ra_opt[IPMIP_DHCP_OPT_DATA]);

                ipmip_dhcp_option_buffer_close(buf);

                pkt         = (Ipmip_dhcp_hdr_t *)IPMIP_BUFFER_PTR(buf);
                pkt->op     = IPMIP_DHCP_OP_BOOTREPLY;
                pkt->hops   = 0;

                if (type != IPMIP_DHCP_MSG_NAK && type != IPMIP_DHCP_MSG_INFORM_ACK)
                    IP_SET_32ON8(&pkt->yiaddr, dnode->dhcp.remote_id);

                /* Send */
                tmp32 = IP_GET_32ON8(&pkt->giaddr);
                if (tmp32 == 0)
                    tmp32 = dnode->dhcp.remote_id;

                /* Always assume unicast; unicast renew will be tunneled */
                ipmip_dhcp_server_reply(&ctx->ipmip6.ipmip, proc, &rpkt->ipmip6.ipmip, node->ifp_home->ifaddr_v4, IP_NULL, IP_FALSE);
            }
        }
        else
        {
            IPMIP6_EVENT_IF(ERR, proc, 
                            ipmip_log_event_add(&ctx->ipmip6.ipmip, 
                                                proc, 
                                                "DHCP Reply Received for %s",
                                                ipmip6ha_node_describe(proc, node)));
        }
    }

done_out:
    /* Free the DHCP packet */
    ipmip_pktbuf_release(&ctx->ipmip6.ipmip, proc, &pbuf->ipmip6.ipmip);
    return IPMIP_TIMER_RET_DONE;
}

IP_STATIC void 
ipmip6ha_pmipv6_dhcpv4_config(struct Ipmip6ha_context                       *ctx,
                              struct Ipmip_proc                             *proc,
                              int                                           action,
                              struct Ipmip6ha_if                            *ifp,
                              Ipmip6ha_pmipv6_dhcpv4_config_global_t        *gcfg,
                              Ipmip6ha_pmipv6_dhcpv4_config_t               *cfg,
                              Ipmip_cli_message_t                           *request)
{   
    IPMIP_UNUSED_PARAMETER(ctx);
    IPMIP_UNUSED_PARAMETER(proc);
    IPMIP_UNUSED_PARAMETER(ifp);

    if (action == IPMIP_CALLBACK_CONFIG_READ)
    {
        cfg->enabled   = ipmip_sysvar_bool(gcfg->enabled, "ipmip6ha.interface.%s.LMA.inet.dhcp.server", ifp->ipmip6.iff.ifname);
        if (cfg->enabled)
            ipmip_dhcp_context_create(&ctx->ipmip6.ipmip, proc);
    }   
    else if (action == IPMIP_CALLBACK_CONFIG_FREE)
    {
        /**/
    }
    else if (action == IPMIP_CALLBACK_CONFIG_DUMP)
    {
        ipmip_cli_config_printf(&request->message,
                                "ipmip6ha.interface.%s.LMA.inet.dhcp.server=%s",
                                ifp->ipmip6.iff.ifname, cfg->enabled? "enabled" : "disabled");
    }
}


IP_STATIC void 
ipmip6ha_pmipv6_dhcpv4_config_global(struct Ipmip6ha_context                        *ctx,
                                     struct Ipmip_proc                              *proc,
                                     int                                            action,
                                     Ipmip6ha_pmipv6_dhcpv4_config_global_t         *gcfg,
                                     Ipmip_cli_message_t                            *request)
{   
    IPMIP_UNUSED_PARAMETER(ctx);
    IPMIP_UNUSED_PARAMETER(proc);

    if (action == IPMIP_CALLBACK_CONFIG_READ)
    {
        gcfg->enabled   = ipmip_sysvar_bool(IP_FALSE, "ipmip6ha.LMA.inet.dhcp.server");
    }   
    else if (action == IPMIP_CALLBACK_CONFIG_FREE)
    {
    }
    else if (action == IPMIP_CALLBACK_CONFIG_DUMP)
    {
        ipmip_cli_config_printf(&request->message,
                                "ipmip6ha.LMA.inet.dhcp.server=%s",
                                gcfg->enabled? "enabled" : "disabled");
    }
}


IP_STATIC int
ipmip6ha_pmipv6_dhcpv4_provide(struct Ipmip6ha_context                  *ctx,
                               struct Ipmip_proc                        *proc,
                               int                                      action,
                               void                                     *gcfg,
                               Ipmip6ha_pmipv6_dhcpv4_config_t          *cfg,
                               Ipmip6ha_pmipv6_dhcpv4_node_t            *handle,
                               struct Ipmip6ha_node_P                   *node,
                               struct Ipmip_timer                       *service)
{
    Ipmip6ha_nemo_dsmipv6_t     *nemo;

    IPMIP_UNUSED_PARAMETER(ctx);
    IPMIP_UNUSED_PARAMETER(proc);
    IPMIP_UNUSED_PARAMETER(service);
    IPMIP_UNUSED_PARAMETER(gcfg);

    if (cfg->enabled)
    {
        if (action == IPMIP_CALLBACK_ENABLE)
        {
            nemo = IPCOM_LIST_FIRST(&node->node.nemo_hoa_v4);
            if (nemo != IP_NULL)
            {
                handle->dhcp.remote_id        = nemo->prefix;

                handle->dhcp.lock             = node->node.lock;
                handle->dhcp.opaque           = node;

                handle->dhcp.process_func     = (Ipmip_timer_func_t)ipmip6ha_pmipv6_dhcpv4_server;
                ipmip_dhcp_register(&ctx->ipmip6.ipmip, proc, &handle->dhcp);

                handle->installed             = IP_TRUE;
            }
        }
        else if (action == IPMIP_CALLBACK_DISABLE || action == IPMIP_CALLBACK_UPDATE)
        {
            if (handle->installed)                
            {
                ipmip_dhcp_unregister(&ctx->ipmip6.ipmip, proc, &handle->dhcp);
                handle->installed = IP_FALSE;
            }

            if (action == IPMIP_CALLBACK_UPDATE)
                return IPMIP_CALLBACK_RET_FAILED;
        }
    }


    /* Don't delay */
    return IPMIP_CALLBACK_RET_SUCCESS;
}

/*
 ****************************************************************************
 * 10                   GLOBAL FUNCTIONS
 ****************************************************************************
 */

IP_GLOBAL void ipmip6ha_pmipv6_dhcpv4_install(struct Ipmip6ha_context *ctx);
IP_GLOBAL void
ipmip6ha_pmipv6_dhcpv4_install(struct Ipmip6ha_context *ctx)
{
    static Ipmip6ha_extension_t   srv;

    ipcom_memset(&srv, 0, sizeof(srv));

    srv.name            = IPMIP6HA_PMIPV6_DHCPV4_SERVER;
    srv.ifp_data_size   = sizeof(Ipmip6ha_pmipv6_dhcpv4_config_t);
    srv.global_data_size= sizeof(Ipmip6ha_pmipv6_dhcpv4_config_global_t);
    srv.node_data_size  = sizeof(Ipmip6ha_pmipv6_dhcpv4_node_t);

    srv.config_global   = (Ipmip6ha_extension_config_global_t)ipmip6ha_pmipv6_dhcpv4_config_global;
    srv.config_ifp      = (Ipmip6ha_extension_config_ifp_t)ipmip6ha_pmipv6_dhcpv4_config;
    srv.provide         = (Ipmip6ha_extension_provide_t)ipmip6ha_pmipv6_dhcpv4_provide;

    /* This is a PMIP only feature */
    ipmip6ha_context_register_extension(ctx, &srv, IP_FALSE, IP_TRUE);
}


/*
 ****************************************************************************
 * 11                   PUBLIC FUNCTIONS
 ****************************************************************************
 */
#else
IP_GLOBAL void ipmip6ha_pmipv6_dhcpv4_install(struct Ipmip6ha_context *ctx);
IP_GLOBAL void
ipmip6ha_pmipv6_dhcpv4_install(struct Ipmip6ha_context *ctx)
{
    IPMIP_UNUSED_PARAMETER(ctx);
}
#endif 

/*
 ****************************************************************************
 *                      END OF FILE
 ****************************************************************************
 */