// SPDX-License-Identifier: GPL-2.0-or-later

  /*

   *
   * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
   */

  #include <linux/module.h>
  #include <linux/proc_fs.h>
  #include <linux/kernel.h>

  #include <linux/interrupt.h>
  #include <linux/fs.h>
  #include <linux/types.h>
  #include <linux/sysctl.h>
  #include <linux/string.h>
  #include <linux/socket.h>
  #include <linux/errno.h>
  #include <linux/fcntl.h>
  #include <linux/in.h>
  #include <linux/if_ether.h>

  #include <linux/slab.h>

  #include <asm/io.h>
  
  #include <linux/inet.h>
  #include <linux/netdevice.h>
  #include <linux/etherdevice.h>
  #include <linux/if_arp.h>
  #include <linux/skbuff.h>
  
  #include <net/ip.h>
  #include <net/arp.h>
  
  #include <net/ax25.h>
  #include <net/rose.h>

  static int rose_header(struct sk_buff *skb, struct net_device *dev,
  		       unsigned short type,

  		       const void *daddr, const void *saddr, unsigned int len)

  {
  	unsigned char *buff = skb_push(skb, ROSE_MIN_LEN + 2);

  	if (daddr)
  		memcpy(buff + 7, daddr, dev->addr_len);

  	*buff++ = ROSE_GFI | ROSE_Q_BIT;
  	*buff++ = 0x00;
  	*buff++ = ROSE_DATA;
  	*buff++ = 0x7F;
  	*buff++ = AX25_P_IP;
  
  	if (daddr != NULL)
  		return 37;
  
  	return -37;
  }

  static int rose_set_mac_address(struct net_device *dev, void *addr)
  {
  	struct sockaddr *sa = addr;

  	int err;

  	if (!memcmp(dev->dev_addr, sa->sa_data, dev->addr_len))

  		return 0;

  	if (dev->flags & IFF_UP) {

  		err = rose_add_loopback_node((rose_address *)sa->sa_data);

  		if (err)
  			return err;
  
  		rose_del_loopback_node((rose_address *)dev->dev_addr);
  	}

  	memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);

  
  	return 0;
  }
  
  static int rose_open(struct net_device *dev)
  {

  	int err;
  
  	err = rose_add_loopback_node((rose_address *)dev->dev_addr);
  	if (err)
  		return err;

  	netif_start_queue(dev);

  	return 0;
  }
  
  static int rose_close(struct net_device *dev)
  {
  	netif_stop_queue(dev);
  	rose_del_loopback_node((rose_address *)dev->dev_addr);
  	return 0;
  }

  static netdev_tx_t rose_xmit(struct sk_buff *skb, struct net_device *dev)

  {

  	struct net_device_stats *stats = &dev->stats;

  	unsigned int len = skb->len;

  
  	if (!netif_running(dev)) {
  		printk(KERN_ERR "ROSE: rose_xmit - called when iface is down
  ");

  		return NETDEV_TX_BUSY;

  	}

  
  	if (!rose_route_frame(skb, NULL)) {
  		dev_kfree_skb(skb);
  		stats->tx_errors++;
  		return NETDEV_TX_OK;
  	}
  
  	stats->tx_packets++;
  	stats->tx_bytes += len;

  	return NETDEV_TX_OK;

  }

  static const struct header_ops rose_header_ops = {
  	.create	= rose_header,

  };

  static const struct net_device_ops rose_netdev_ops = {
  	.ndo_open		= rose_open,
  	.ndo_stop		= rose_close,
  	.ndo_start_xmit		= rose_xmit,
  	.ndo_set_mac_address    = rose_set_mac_address,
  };

  void rose_setup(struct net_device *dev)
  {

  	dev->mtu		= ROSE_MAX_PACKET_SIZE - 2;

  	dev->netdev_ops		= &rose_netdev_ops;

  	dev->header_ops		= &rose_header_ops;

  	dev->hard_header_len	= AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN;
  	dev->addr_len		= ROSE_ADDR_LEN;
  	dev->type		= ARPHRD_ROSE;

  
  	/* New-style flags. */

  	dev->flags		= IFF_NOARP;

  }