/**
 * @file
 * Ethernet Interface Skeleton
 *
 */

/*
 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
 * All rights reserved. 
 * 
 * Redistribution and use in source and binary forms, with or without modification, 
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission. 
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 
 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 
 * OF SUCH DAMAGE.
 *
 * This file is part of the lwIP TCP/IP stack.
 * 
 * Author: Adam Dunkels <adam@sics.se>
 *
 */

/*
 * This file is a skeleton for developing Ethernet network interface
 * drivers for lwIP. Add code to the low_level functions and do a
 * search-and-replace for the word "ethernetif" to replace it with
 * something that better describes your network interface.
 */

#include "lwip/opt.h"

#if 1 /* don't build, this is only a skeleton, see previous comment */

#include "lwip/def.h"
#include "lwip/mem.h"
#include "lwip/pbuf.h"
#include <lwip/stats.h>
#include <lwip/snmp.h>
#include "netif/etharp.h"
#include "netif/ppp_oe.h"

#include <string.h>
#include <sys/ioctl.h>
#include <xbook/driver.h>
#include <xbook/net.h>
#include <xbook/debug.h>

/* Define those to better describe your network interface. */
#define IFNAME0 'e'
#define IFNAME1 'n'


#define ETHDEVNAME "rtl8139"

#define ETH_MTU 1500

/**
 * Helper struct to hold private data used to operate your ethernet interface.
 * Keeping the ethernet address of the MAC in this struct is not necessary
 * as it is already kept in the struct netif.
 * But this is only an example, anyway...
 */
struct ethernetif {
  struct eth_addr *ethaddr;
  /* Add whatever per-interface state that is needed here. */
  int netsolt;      /* netcard solt */
};

/* Forward declarations. */
//static void ethernetif_input(struct netif *netif);

/**
 * In this function, the hardware should be initialized.
 * Called from ethernetif_init().
 *
 * @param netif the already initialized lwip network interface structure
 *        for this ethernetif
 */
static void
low_level_init(struct netif *netif)
{
    struct ethernetif *ethernetif = netif->state;

    /* 查找第一张网卡 */
    ethernetif->netsolt = netcard_find_by_name("netcard0");
    if (ethernetif->netsolt < 0) {
        dbgprint("[lwip]: can't found netcard, stop TCP/IP service.\n");
        spin("low_level_init");
    }
    if (drv_netcard.open(ethernetif->netsolt) < 0) {
        dbgprint("[lwip]: open netcard failed!\n");
        spin("low_level_init");
        return;
    }
    u8_t mac_addr[ETHARP_HWADDR_LEN] = {0};
#if 1
    drv_netcard.ioctl(ethernetif->netsolt, NETIO_GETMAC, &mac_addr[0]);
    dbgprint("mac: %x %x %x %x %x %x\n", mac_addr[0], mac_addr[1], mac_addr[2], mac_addr[3], mac_addr[4], mac_addr[5]);
#endif
  /* set MAC hardware address length */
  netif->hwaddr_len = ETHARP_HWADDR_LEN;

    /* set MAC hardware address in netif*/
    int i;
    for (i = 0; i < ETHARP_HWADDR_LEN; i++) {
        netif->hwaddr[i] = mac_addr[i];
    }

  /* set maximum transfer unit */
  netif->mtu = ETH_MTU;
  
  /* set device capabilities */
  /* don't set NETIF_FLAG_ETHARP if this device is not an ethernet one */
  netif->flags = NETIF_FLAG_BROADCAST | NETIF_FLAG_ETHARP | NETIF_FLAG_LINK_UP;
 
  /* Do whatever else is needed to initialize interface. */  
}

/* 包缓冲区，存放多个包，然后一次性发送 */
static unsigned char eth_send_buf[ETH_MTU];
/**
 * This function should do the actual transmission of the packet. The packet is
 * contained in the pbuf that is passed to the function. This pbuf
 * might be chained.
 *
 * @param netif the lwip network interface structure for this ethernetif
 * @param p the MAC packet to send (e.g. IP packet including MAC addresses and type)
 * @return ERR_OK if the packet could be sent
 *         an err_t value if the packet couldn't be sent
 *
 * @note Returning ERR_MEM here if a DMA queue of your MAC is full can lead to
 *       strange results. You might consider waiting for space in the DMA queue
 *       to become availale since the stack doesn't retry to send a packet
 *       dropped because of memory failure (except for the TCP timers).
 */
static err_t
low_level_output(struct netif *netif, struct pbuf *p)
{
  struct ethernetif *ethernetif = netif->state;
  struct pbuf *q;
  err_t retval = ERR_OK;
    int len;
#if ETH_PAD_SIZE
  pbuf_header(p, -ETH_PAD_SIZE); /* drop the padding word */
#endif
  unsigned int templen = 0;
  for(q = p; q != NULL; q = q->next) {
    /* Send the data from the pbuf to the interface, one pbuf at a
       time. The size of the data in each pbuf is kept in the ->len
       variable. */
    memcpy(&eth_send_buf[templen], q->payload, q->len);
    templen += q->len;
    /* 有效性校验，防止数据溢出 */
    if (templen > ETH_MTU || templen > p->tot_len) {
        LWIP_PLATFORM_DIAG(("packet send: error, templen=%d, tolen=%d\n", 
            templen, p->tot_len));
        return ERR_BUF;
    }
  }
  /* 拷贝完毕，进行数据发送 */
  if (templen == p->tot_len) {
    len = drv_netcard.write(ethernetif->netsolt, eth_send_buf, templen);
    if (len < 0) {
        retval = ERR_BUF;
    }
  }
#if ETH_PAD_SIZE
  pbuf_header(p, ETH_PAD_SIZE); /* reclaim the padding word */
#endif
  
  LINK_STATS_INC(link.xmit);   //协议栈内部的数据统计

  return retval;
}

/* 包缓冲区，存放一个包，然后解析成pbuf */
static unsigned char eth_recv_buf[ETH_MTU];
/**
 * Should allocate a pbuf and transfer the bytes of the incoming
 * packet from the interface into the pbuf.
 *
 * @param netif the lwip network interface structure for this ethernetif
 * @return a pbuf filled with the received packet (including MAC header)
 *         NULL on memory error
 */
static struct pbuf *
low_level_input(struct netif *netif)
{
  struct ethernetif *ethernetif = netif->state;
  struct pbuf *p, *q;
  int recvlen;
  unsigned int i = 0;
  recvlen = drv_netcard.read(ethernetif->netsolt, eth_recv_buf, ETH_MTU);
  if (recvlen < 0)
    return 0;
#if ETH_PAD_SIZE
  recvlen += ETH_PAD_SIZE; /* allow room for Ethernet padding */
#endif

  /* We allocate a pbuf chain of pbufs from the pool. */
  p = pbuf_alloc(PBUF_RAW, recvlen, PBUF_RAM);
  
  if (p != NULL) {

#if ETH_PAD_SIZE
    pbuf_header(p, -ETH_PAD_SIZE); /* drop the padding word */
#endif

    /* We iterate over the pbuf chain until we have read the entire
     * packet into the pbuf. */
    q = p;
    while (q != NULL) {
        /* Read enough bytes to fill this pbuf in the chain. The
       * available data in the pbuf is given by the q->len
       * variable.
       * This does not necessarily have to be a memcpy, you can also preallocate
       * pbufs for a DMA-enabled MAC and after receiving truncate it to the
       * actually received size. In this case, ensure the tot_len member of the
       * pbuf is the sum of the chained pbuf len members.
       */
        memcpy((u8_t*)q->payload, &eth_recv_buf[i], q->len);
        i += q->len;
        q = q->next;
        if (i >= recvlen)
            break;
    }

#if ETH_PAD_SIZE
    pbuf_header(p, ETH_PAD_SIZE); /* reclaim the padding word */
#endif

    LINK_STATS_INC(link.recv);
  } else {
    LWIP_PLATFORM_DIAG(("packet receive: pbuf alloc fail, len=%d\n", 
        recvlen));
    //drop packet();
    LINK_STATS_INC(link.memerr);
    LINK_STATS_INC(link.drop);
  }

  return p;  
}

/**
 * This function should be called when a packet is ready to be read
 * from the interface. It uses the function low_level_input() that
 * should handle the actual reception of bytes from the network
 * interface. Then the type of the received packet is determined and
 * the appropriate input function is called.
 *
 * @param netif the lwip network interface structure for this ethernetif
 */
void ethernetif_input(struct netif *netif)
{
  //struct ethernetif *ethernetif;
  struct eth_hdr *ethhdr;
  struct pbuf *p;

  //ethernetif = netif->state;

  /* move received packet into a new pbuf */
  p = low_level_input(netif);
  /* no packet could be read, silently ignore this */
  if (p == NULL) return;
  /* points to packet payload, which starts with an Ethernet header */
  ethhdr = p->payload;

  switch (htons(ethhdr->type)) {
  /* IP or ARP packet? */
  case ETHTYPE_IP:
  case ETHTYPE_ARP:
#if PPPOE_SUPPORT
  /* PPPoE packet? */
  case ETHTYPE_PPPOEDISC:
  case ETHTYPE_PPPOE:
#endif /* PPPOE_SUPPORT */
    /* full packet send to tcpip_thread to process */
    if (netif->input(p, netif)!=ERR_OK)
     { LWIP_DEBUGF(NETIF_DEBUG, ("ethernetif_input: IP input error\n"));
       pbuf_free(p);
       p = NULL;
     }
    break;

  default:
    pbuf_free(p);
    p = NULL;
    break;
  }
}

/**
 * Should be called at the beginning of the program to set up the
 * network interface. It calls the function low_level_init() to do the
 * actual setup of the hardware.
 *
 * This function should be passed as a parameter to netif_add().
 *
 * @param netif the lwip network interface structure for this ethernetif
 * @return ERR_OK if the loopif is initialized
 *         ERR_MEM if private data couldn't be allocated
 *         any other err_t on error
 */
err_t
ethernetif_init(struct netif *netif)
{
  struct ethernetif *ethernetif;

  LWIP_ASSERT("netif != NULL", (netif != NULL));
    
  ethernetif = mem_malloc(sizeof(struct ethernetif));
  if (ethernetif == NULL) {
    LWIP_DEBUGF(NETIF_DEBUG, ("ethernetif_init: out of memory\n"));
    return ERR_MEM;
  }

#if LWIP_NETIF_HOSTNAME
  /* Initialize interface hostname */
  netif->hostname = "lwip";
#endif /* LWIP_NETIF_HOSTNAME */

  /*
   * Initialize the snmp variables and counters inside the struct netif.
   * The last argument should be replaced with your link speed, in units
   * of bits per second.
   */
  NETIF_INIT_SNMP(netif, snmp_ifType_ethernet_csmacd, 0);

  netif->state = ethernetif;
  netif->name[0] = IFNAME0;
  netif->name[1] = IFNAME1;
  /* We directly use etharp_output() here to save a function call.
   * You can instead declare your own function an call etharp_output()
   * from it if you have to do some checks before sending (e.g. if link
   * is available...) */
  netif->output = etharp_output;
  netif->linkoutput = low_level_output;
  
  ethernetif->ethaddr = (struct eth_addr *)&(netif->hwaddr[0]);
  
  /* initialize the hardware */
  low_level_init(netif);

  return ERR_OK;
}

#endif /* 0 */
