/*
 ******************************************************************************
 *                     INTERPEAK SOURCE FILE
 *
 *   Document no: @(#) $Name: VXWORKS_ITER40_2019102207 $ $RCSfile: ipmipha_agent.c,v $ $Revision: 1.11 $
 *   $Source: /home/interpeak/CVSRoot/ipmipha/src/ipmipha_agent.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 "ipmipha_config.h"

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

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

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


#include <ipmip4.h>
#include <private/ipmip4_context.h>
#include <private/ipmip4_util.h>
#include <private/ipmip4_sysext.h>
#include <private/ipmip4_auth.h>
#include <private/ipmip4_pkt.h>

#include "ipmipha.h"
#include "ipmipha_h.h"
#include "ipmipha_attr_h.h"
#include "ipmipha_if.h"
#include "ipmipha_agent.h"
#include "ipmipha_pktbuf.h"

/*
 ****************************************************************************
 * 4                    DEFINES
 ****************************************************************************
 */

/*
 ****************************************************************************
 * 5                    TYPES
 ****************************************************************************
 */

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

/*
 ****************************************************************************
 * 7                    LOCAL PROTOTYPES
 ****************************************************************************
 */

/*
 ****************************************************************************
 * 8                    DATA
 ****************************************************************************
 */

/*
 ****************************************************************************
 * 9                    STATIC FUNCTIONS
 ****************************************************************************
 */

/*
 *===========================================================================
 *                    ipmipha_agent_advert_build
 *===========================================================================
 * Description: Create an advertisement.
 * Parameters:  data    - Context
 *              proc    - Process
 *              adv     - The buffer to create the advertisement in.
 *              iff     - The interface for which we create the buffer.
 *              lla_ext - Append the interfaces LLA extension
 * Returns:     IP_TRUE on success.
 *
 */
IP_STATIC Ip_bool
ipmipha_agent_advert_build(Ipmipha_data_t       *data,
                           Ipmip_proc_t        *proc,
                           Ipmip_buffer_t      *adv,
                           Ipmipha_iff_t        *iff)
{
    Ipmip4_icmp_advert_t     advpkt;
    Ipmip4_icmp_advert_t     *advpktp;
    Ipmip4_icmp_ext_advert_t adv_ext;
    Ip_u16                   adv_seq;

    ipcom_memset(&advpkt, 0, sizeof(advpkt));
    ipcom_memset(&adv_ext, 0, sizeof(adv_ext));

    /* ICMP advertisement header */
    advpkt.icmp_type           = IPMIP4_ICMP_AGENT_ADVERTISEMENT;
    advpkt.icmp_code           = data->ipnet_is_router ? IPMIP4_ICMP_CODE_GENERIC_ROUTER : IPMIP4_ICMP_CODE_AGENT_ONLY;
    advpkt.icmp_checksum       = 0;
    advpkt.adv_num_addrs       = 0;
    advpkt.adv_addr_entry_size = 2;
    advpkt.adv_lifetime        = ip_htons(iff->adv_lifetime);

    ipmip_buffer_append(adv, &advpkt, sizeof(advpkt));

    /* Store */
    adv_seq = iff->adv_seq;

    /* Add mobility agent advertisement extension */
    adv_ext.type         = IPMIP4_ICMP_EXT_TYPE_MOBILITY_AGENT_ADV;
    adv_ext.length       = 6;  
    adv_ext.seq          = ip_htons(adv_seq);
    adv_ext.reg_lifetime = ip_htons(iff->lifetime);
    adv_ext.flags        = ip_ntohs(IPMIP4_ICMP_ADVEXT_FLAG_HOME_AGENT);

    ipmip_buffer_append(adv, &adv_ext, sizeof(adv_ext) - sizeof(adv_ext.coa));

    if (iff->nai_ha != IP_NULL)
        ipmip4_msgext_buffer_append_shdr(adv, iff->nai_ha);

    if (++iff->adv_seq == 0)
        /* Roll-over prevention, so it does not look like we have rebooted */
        iff->adv_seq = 256;

    advpktp = IPMIP_BUFFER_PTR(adv);
    advpktp->icmp_checksum = ipcom_in_checksum(IPMIP_BUFFER_DATA(adv), IPMIP_BUFFER_SIZE(adv));

    IPMIP4_EVENT_IF(DEBUG2, proc, 
                    ipmip_log_event_add(&data->ipmip4.ipmip, 
                                        proc, 
                                        "Sending Router Advertisement on %s with sequence #%u",
                                        iff->iff.ipmip.ifname, adv_seq));

    /* Return advlen */
    return IP_TRUE;
}


/*
 *===========================================================================
 *                    ipmipha_agent_solicitation_input
 *===========================================================================
 * Description: Process received ICMP Agent solicitations.
 * Parameters:  pbuf    - The packet buffer
 * Returns:      
 *
 */
IP_STATIC Ip_bool
ipmipha_agent_solicitation_input(Ipmipha_data_t         *data,
                                 Ipmip_proc_t          *proc,
                                 Ipmipha_pktbuf_t       *pbuf)
{
    Ip_u8                   *ext_start;
    int                     ext_len;
    int                     i;
    Ipmip4_icmp_solicit_t   *solpkt;
    int                     sol_len;

    /* Solicitation packet */
    solpkt      = IPMIP_BUFFER_PTR(&pbuf->ipmip4.ipmip.packet);
    sol_len     = sizeof(Ipmip4_icmp_solicit_t);

    if (IPMIP_BUFFER_SIZE(&pbuf->ipmip4.ipmip.packet) < (unsigned)sol_len)
        return IP_FALSE;

    if (pbuf->ipmip4.ipmip.srcinfo.ttl != 1)
    {
        IPMIP4_EVENT_IF(WARNING, proc, 
                        ipmip_log_event_add(&data->ipmip4.ipmip, 
                                            proc, 
                                            "Router Solicitation input on %s from %s failed since TTL != 1",
                                            pbuf->iff.pub->ipmip.ifname,
                                            ipmip_ntop_inet(proc, pbuf->ipmip4.ipmip.srcinfo.src->sin.sin_addr.s_addr)));
        return IP_FALSE;
    }

    /* Extension part */
    ext_start   = ipmip_buffer_offset(&pbuf->ipmip4.ipmip.packet, sol_len);
    ext_len     = IPMIP_BUFFER_SIZE(&pbuf->ipmip4.ipmip.packet) - sol_len;

    i = ipmip4_msgext_icmp_parse(proc,
                                 pbuf->iff.pub->ipmip.ifname,
                                 pbuf->ipmip4.ipmip.srcinfo.src->sin.sin_addr.s_addr,
                                 &pbuf->ipmip4.ext.icmp,
                                 ext_start,
                                 ext_len);

    if (i != IPMIP4_REG_EXT_SUCCESS)
        return IP_FALSE;


    IPMIP4_EVENT_IF(DEBUG2, proc, 
                    ipmip_log_event_add(&data->ipmip4.ipmip, 
                                        proc, 
                                        "Router Solicitation received on %s from %s/%s",
                                        pbuf->iff.pub->ipmip.ifname,
                                        ipmip_ntop_inet(proc, pbuf->ipmip4.ipmip.srcinfo.src->sin.sin_addr.s_addr),
                                        ipmip_ntop_lladdr(proc, pbuf->ipmip4.ipmip.srcinfo.lladdr)));

    /* Write a directed output */
    ipmipha_agent_advert_output(data,
                                proc,
                                pbuf->iff.priv,
                                (Ip_u32 *)&pbuf->ipmip4.ipmip.srcinfo.src->sin.sin_addr.s_addr,
                                pbuf->ipmip4.ipmip.srcinfo.lladdr);
    
    return IP_FALSE;
}


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

/*
 *===========================================================================
 *                    ipmipha_agent_advert_output
 *===========================================================================
 * Description:   Write an ordinary multicast/unicast advertisement
 * Parameters:    data  - Context
 *                proc  - Process
 *                iff   - The interface to send the advertisment from.
 *                dst   - If specified, unicast dst address
 *                lla   - If specified, unicast LLA address
 * Returns:       
 *
 */
IP_GLOBAL void
ipmipha_agent_advert_output(Ipmipha_data_t          *data,
                            Ipmip_proc_t           *proc,
                            Ipmipha_iff_t           *iff,
                            Ip_u32                  *dst,
                            Ipmip_lladdr_t          *lladdr)
{
    Ipmip_buffer_t adv;

    ipmip_buffer_init(&adv);
    /* Create the advertisement */
    if (ipmipha_agent_advert_build(data, proc, &adv, iff))
    {
        /* If dst is zero, specify it as the advertisement address */
        if (dst == IP_NULL)
            dst = &iff->adv_address;

        /* Write the request */
        if (ipmip4_pkt_icmp_write(&data->ipmip4,
                                  proc,
                                  &adv,
                                  iff->iff.ifaddr,
                                  *dst,
                                  &iff->iff,
                                  lladdr) != IP_TRUE)
        {
            IPMIP4_EVENT_IF(ERR, proc, 
                            ipmip_log_event_add(&data->ipmip4.ipmip, 
                                                proc, 
                                                "Failed to send %s Router Advertisement on %s",
                                                (dst == &iff->adv_address)? "unicast" : "multicast",
                                                iff->iff.ipmip.ifname));
        }

        ipmip_buffer_release(&adv);
    }
}


/*
 *===========================================================================
 *                    ipmipha_adv_recv
 *===========================================================================
 * Description:   Handles incoming advertisements or solicitations
 * Parameters:    data          - Context
 *                proc          - Current process.
 *                pbuf          - Packet buffer
 * Returns:       
 *
 */
IP_GLOBAL void 
ipmipha_adv_recv(struct Ipmipha_data         *data,
                 struct Ipmip_proc          *proc,                 
                 Ipmipha_pktbuf_t            *pbuf)
{
    if (data->conf == IP_NULL)
        return;

    if (pbuf->ipmip4.ipmip.srcinfo.lladdr != IP_NULL)
    {
        Ipcom_icmp_header       *icmph   = IPMIP_BUFFER_PTR(&pbuf->ipmip4.ipmip.packet);

        /* Truncated packet? */
        if (IPMIP_BUFFER_SIZE(&pbuf->ipmip4.ipmip.packet) < IPCOM_ICMP_HEADER_LENGTH)
            goto done_out;

        if (pbuf->ipmip4.ipmip.srcinfo.dst->dst.sin.sin_addr.s_addr == ip_htonl(IP_INADDR_ALLHOSTS_GROUP)
            || pbuf->ipmip4.ipmip.srcinfo.dst->dst.sin.sin_addr.s_addr == ip_htonl(IP_INADDR_ALLRTRS_GROUP)
            || pbuf->ipmip4.ipmip.srcinfo.dst->dst.sin.sin_addr.s_addr == ip_htonl(IP_INADDR_ALLMA_GROUP)
            || pbuf->ipmip4.ipmip.srcinfo.dst->dst.sin.sin_addr.s_addr == 0xffffffff)
        {
            /* Must find the interface */
            if ((pbuf->iff.pub = (Ipmip4_if_t *)ipmip_if_findbyindex(&data->conf->if_head, pbuf->ipmip4.ipmip.srcinfo.dst->ifindex)) == IP_NULL)
                goto done_out;
        }
        else if ((pbuf->iff.pub = ipmip4_if_findbyaddr(&data->conf->if_head, pbuf->ipmip4.ipmip.srcinfo.dst->dst.sin.sin_addr.s_addr)) == IP_NULL)
                 goto done_out;

        switch (icmph->type)
        {
        case IPMIP4_ICMP_ROUTER_SOLICITATION:
            if (IP_BIT_ISFALSE(data->shutdown, IPMIPHA_SHUTDOWN_ADV))
            {
                if (ipmipha_agent_solicitation_input(data, proc, pbuf))
                    return;
            }
        }
    }

done_out:
    /* Free the packet buffer */
    ipmip_pktbuf_release(&data->ipmip4.ipmip, proc, &pbuf->ipmip4.ipmip);
}


/*
 ****************************************************************************
 * 11                   PUBLIC FUNCTIONS
 ****************************************************************************
 */

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