sitara_depot/components/free_rtos/ethernet_ip/eth_arp.cpp

/*
 * eth_arp.cpp
 *
 *  Created on: 13 ìàð. 2023 ã.
 *      Author: sychev
 */
#include "ethernet_ip/eth_arp.hpp"
#include "ethernet/eth_frame.h"
#include "ethernet_ip/eth_prots_id.h"
#include "ethernet_ip/eth_ip_types.h"

#include <cstring>

#define ARP_ETH_TYPE_BE 0x1000

void free_rtos::clock_timeout(ClockP_Object * obj, void * arg)
{
    EthArp * p_arp = ( EthArp *)arg;

    /// Çàïðàøèâàåì ñîáñòâåííûé ip
    if (p_arp->tmrGratuitous_.tick(100))
    {
        if (p_arp->table_mac_.empty()) {
            p_arp->request(p_arp->self_ip_);
        }
    }

    for (auto& item : p_arp->table_ip_)
    {
        auto& ip_data = item.second;
        if (ip_data.tmr.tick(100))
        {
            if (++ip_data.attemps >= p_arp->max_attemps_)
            {
                ip_data.tmr.stop();
                ip_data.attemps = 0;
            }
            else
            {
                p_arp->request(item.first); /// Çàïðîñ mac àäðåñà ïî ip
            }
        }
    }
}

free_rtos::EthArp::EthArp(EthStackIface& eth_stack) :
        eth_stack_{eth_stack}
{

}

bool free_rtos::EthArp::init(TEthMacPorts eth_port_id, uint64_t self_mac, uint32_t self_ip)
{
    self_mac_ = self_mac;
    self_ip_ = self_ip;

    eth_port_id_ = eth_port_id;

    init_request_pkt(self_mac_, self_ip_);

    clock_.init(100, free_rtos::clock_timeout, this); /// 100ìñ

    tmrGratuitous_.start(1000); /// 1 ðàç â ñåêóíäó

    clock_.start();

    return true;
}

void free_rtos::EthArp::init_request_pkt(uint64_t self_mac, uint32_t self_ip)
{
    TArpHeader * arp_hdr = (TArpHeader *)(request_pkt_.data + sizeof(TEthFrameHeader));

    /// Çàïîëíÿåì çàãîëîâîê ARP
    memcpy(arp_hdr->ar_sha, &self_mac_, ETH_FRAME_MAC_ADDR_LEN_BYTES);
    memset(arp_hdr->ar_tha, 0, ETH_FRAME_MAC_ADDR_LEN_BYTES);
    memcpy(arp_hdr->ar_spa, &self_ip_, ETH_IP_ADDR_LEN);

    arp_hdr->ar_op = arp_opr_be_[e_oprRequest];
    arp_hdr->ar_hrd = ARP_ETH_TYPE_BE;
    arp_hdr->ar_pro = ETH_PROT_IP_BE;

    arp_hdr->ar_hln = ETH_FRAME_MAC_ADDR_LEN_BYTES;

    arp_hdr->ar_pln = ETH_IP_ADDR_LEN;
}

bool free_rtos::EthArp::request(uint32_t ip)
{
    TArpHeader * arp_hdr = (TArpHeader *)(request_pkt_.data + sizeof(TEthFrameHeader));

    /// Êîïèðóåì ip-àäðåñ äëÿ çàïðîñà
    memcpy(arp_hdr->ar_tpa, &ip, ETH_IP_ADDR_LEN);

    request_pkt_.length = sizeof(TArpHeader);

    /// Øèðîêîâåùàòåëüíûé çàïðîñ
    return eth_stack_.send_pkt(eth_port_id_, ETH_FRAME_MAC_ADDR_BROADCAST, ETH_PROT_ARP_BE, request_pkt_);
}

bool free_rtos::EthArp::try_request(uint32_t ip)
{
    ArpIpReqData * p_ip_req_data = nullptr;
    auto item = table_ip_.find(ip);

    if (item == table_ip_.end())
    {
        p_ip_req_data = &table_ip_[ip]; ///
    }
    else
    {
        p_ip_req_data = &item->second;
        if (p_ip_req_data->mac != 0) {
            return true; /// Ìàê àäðåñ óæå èçâåñòåí
        }
        else if (p_ip_req_data->tmr.is_started()) {
            return true; /// Îïðîñ óæå èäåò

        }
    }

    p_ip_req_data->attemps = 0;
    p_ip_req_data->tmr.start(1000); /// Îïðîñ 1 ðàçâ â ñåê

    return request(ip);
}

void free_rtos::EthArp::add(uint64_t mac, uint32_t ip) {
    table_mac_[mac] = ip;

    auto& item = table_ip_[ip];

    item.mac = mac;
    item.attemps = 0;
    item.tmr.stop();
}

bool free_rtos::EthArp::getIpAddr(uint64_t mac, uint32_t& ip) {
    auto item = table_mac_.find(mac);

    if (item == table_mac_.end()) {
        return false;
    }

    ip = item->second;

    return true;
}

bool free_rtos::EthArp::getMacAddr(uint32_t ip, uint64_t& mac) {
    auto item = table_ip_.find(ip);

    if (item == table_ip_.end()) {
        try_request(ip);
        return false;
    }

    mac = item->second.mac;

    return true;
}

int32_t free_rtos::EthArp::Process(uint8_t * p_data, uint32_t len)
{
    TArpHeader * arp_hdr = (TArpHeader *)(p_data);
    uint16_t type = arp_hdr->ar_op;

    uint64_t mac_sender = 0;
    uint32_t ip_sender = 0;

    memcpy(&mac_sender, arp_hdr->ar_sha, ETH_FRAME_MAC_ADDR_LEN_BYTES);
    memcpy(&ip_sender, arp_hdr->ar_spa, ETH_IP_ADDR_LEN);

    /**
     * åñëè ip == 0, òî ýòî çàïðîñ "Who has....".
     * Îòâå÷àòü íà íåãî íå íóæíî.
     */
    if (ip_sender == 0) {
        return 0;
    }
    /// Äîáàâëÿåì çàïèñü â arp-òàáëèöó
    add(mac_sender, ip_sender);

    if ( type == arp_opr_be_[e_oprRequest])
    {
        uint32_t ip_target;
        memcpy(&ip_target, arp_hdr->ar_tpa, ETH_IP_ADDR_LEN);

        if (ip_target == self_ip_)
        {
            /// Òèï ïàêåòà - îòâåò
            arp_hdr->ar_op = arp_opr_be_[e_oprReply];
            /// Ìåíÿåì ìåñòàìè mac àäðåñ
            memcpy(arp_hdr->ar_tha, arp_hdr->ar_sha, ETH_FRAME_MAC_ADDR_LEN_BYTES);
            memcpy(arp_hdr->ar_sha, &self_mac_, ETH_FRAME_MAC_ADDR_LEN_BYTES);
            /// Ìåíÿåì ìåñòàìè ip àäðåñ
            memcpy(arp_hdr->ar_tpa, arp_hdr->ar_spa, ETH_IP_ADDR_LEN);
            memcpy(arp_hdr->ar_spa, &self_ip_, ETH_IP_ADDR_LEN);

            /// Îòïðàâëÿåì ðàçìåð ïàêåòà äëÿ îòïðàâêè
            return len;
        }
    }

    return 0;
}