W6300 使用 SOCKET-less 指令实现 ping 功能

本篇总结

基于 W6300 的 SOCKET-less Command（SLCR）PING4 指令实现 ping 功能，通过 SLIR 判断结果，并统计请求、回复与丢包数量。

硬件平台：本例程基于 W6300-EVB-M4 开发板运行。

采购推荐：点击前往 WIZnet 官方淘宝店铺 选购 W6300-EVB-M4 开发板

W6300 的优势

W6300 的 TOE 引擎原生支持 PING4 免套接字指令，ICMP 报文的构造、校验和计算、收发处理全部由硬件完成。用户只需通过寄存器配置目标地址、PING ID 和序列号，触发 SLCR[PING4] 后轮询 SLIR 结果即可。相比手动构造 ICMP 报文，代码更简洁，不占用 Socket 资源，可靠性更高。

uint8_t dest_ip[4] = {192, 168, 1, 20};
uint8_t ping_num = 4;

while (1)
{
    do_ping(SOCKET_ID, dest_ip, ping_num);
}

void do_ping(uint8_t sn, uint8_t *remote_ip, uint8_t req_num)
{
    ping_config_t config;

    (void)sn;

    if (s_ping_compat_initialized == 0U)
    {
        if ((remote_ip == NULL) || (req_num == 0U))
        {
            return;
        }

        memset(&config, 0, sizeof(config));
        config.target_use_gateway = 0U;
        memcpy(config.target_ip, remote_ip, sizeof(config.target_ip));
        config.id = 0x1234U;
        config.interval_ms = 3000U;
        config.command_timeout_ms = 100U;
        config.response_timeout_ms = 5000U;

        s_ping_request_limit = req_num;
        s_ping_completed_count = 0U;
        s_ping_reply_count = 0U;

        if (ping_init(&config) < 0)
        {
            return;
        }

        s_ping_compat_initialized = 1U;
    }

    ping_run();
}

void ping_run(void)
{
    uint32_t now = wiz_platform_get_tick();
    uint8_t slir;

    switch (s_ping_state)
    {
        case PING_STATE_IDLE:
            if ((uint32_t)(now - s_ping_state_tick) >= s_ping_config.interval_ms)
            {
                ping_start(now);
            }
            break;

        case PING_STATE_WAIT_COMMAND:
            if (getSLCR() == 0U)
            {
                s_ping_state = PING_STATE_WAIT_RESULT;
            }
            else if ((uint32_t)(now - s_ping_request_tick) >= s_ping_config.command_timeout_ms)
            {
                printf("PING command: timeout\r\n");
                ping_finish_cycle(now, 0U);
            }
            break;

        case PING_STATE_WAIT_RESULT:
            slir = getSLIR();

            if ((slir & SLIR_PING4) != 0U)
            {
                printf("PING reply: %u.%u.%u.%u, seq=%u, elapsed=%lu ms\r\n",
                       (unsigned int)s_ping_target_ip[0],
                       (unsigned int)s_ping_target_ip[1],
                       (unsigned int)s_ping_target_ip[2],
                       (unsigned int)s_ping_target_ip[3],
                       (unsigned int)s_ping_sequence,
                       (unsigned long)(now - s_ping_request_tick));
                ping_finish_cycle(now, 1U);
            }
            else if ((slir & SLIR_TOUT) != 0U)
            {
                printf("PING timeout: %u.%u.%u.%u\r\n",
                       (unsigned int)s_ping_target_ip[0],
                       (unsigned int)s_ping_target_ip[1],
                       (unsigned int)s_ping_target_ip[2],
                       (unsigned int)s_ping_target_ip[3]);
                ping_finish_cycle(now, 0U);
            }
            else if ((uint32_t)(now - s_ping_request_tick) >= s_ping_config.response_timeout_ms)
            {
                printf("PING response: timeout\r\n");
                ping_finish_cycle(now, 0U);
            }
            break;

        default:
            ping_clear_result();
            s_ping_state = PING_STATE_IDLE;
            s_ping_state_tick = now;
            break;
    }
}

static void ping_start(uint32_t now)
{
    if ((s_ping_request_limit != 0U) && (s_ping_completed_count >= s_ping_request_limit))
    {
        return;
    }

    ping_clear_result();

    s_ping_sequence++;
    setPINGIDR(s_ping_config.id);
    setPINGSEQR(s_ping_sequence);
    setSLDIP4R(s_ping_target_ip);
    setSLCR(SLCR_PING4);

    s_ping_request_tick = now;
    s_ping_state = PING_STATE_WAIT_COMMAND;

    printf("PING request: %u.%u.%u.%u, id=%u, seq=%u\r\n",
           (unsigned int)s_ping_target_ip[0],
           (unsigned int)s_ping_target_ip[1],
           (unsigned int)s_ping_target_ip[2],
           (unsigned int)s_ping_target_ip[3],
           (unsigned int)s_ping_config.id,
           (unsigned int)s_ping_sequence);
}

免套接字指令要点

setPINGIDR() / setPINGSEQR() 设置 ICMP 报文的标识符和序列号，setSLDIP4R() 写入目标 IP，最后 setSLCR(SLCR_PING4) 触发命令。整个过程无需用户构造 ICMP 报文，也无需计算校验和，TOE 硬件会自动完成。

static void ping_finish_cycle(uint32_t now, uint8_t reply_received)
{
    ping_clear_result();
    s_ping_state = PING_STATE_IDLE;
    s_ping_state_tick = now;

    if ((s_ping_request_limit != 0U) && (s_ping_completed_count < s_ping_request_limit))
    {
        s_ping_completed_count++;
        if (reply_received != 0U)
        {
            s_ping_reply_count++;
        }

        if (s_ping_completed_count >= s_ping_request_limit)
        {
            printf("Ping Request = %u, Ping Reply = %u, Lost = %u\r\n",
                   (unsigned int)s_ping_completed_count,
                   (unsigned int)s_ping_reply_count,
                   (unsigned int)(s_ping_completed_count - s_ping_reply_count));
        }
    }
}