// SPDX-License-Identifier: GPL-2.0+

  /*
   * (C) Copyright 2004
   * Wolfgang Denk, DENX Software Engineering, wd@denx.de.

   */
  
  #include <common.h>

  #include <command.h>

  #include <env.h>

  #include <stdio_dev.h>

  #include <net.h>

  #ifndef CONFIG_NETCONSOLE_BUFFER_SIZE
  #define CONFIG_NETCONSOLE_BUFFER_SIZE 512
  #endif
  
  static char input_buffer[CONFIG_NETCONSOLE_BUFFER_SIZE];

  static int input_size; /* char count in input buffer */
  static int input_offset; /* offset to valid chars in input buffer */
  static int input_recursion;
  static int output_recursion;

  static int net_timeout;

  static uchar nc_ether[6]; /* server enet address */

  static struct in_addr nc_ip; /* server ip */

  static short nc_out_port; /* target output port */
  static short nc_in_port; /* source input port */

  static const char *output_packet; /* used by first send udp */
  static int output_packet_len;

  /*
   * Start with a default last protocol.
   * We are only interested in NETCONS or not.
   */
  enum proto_t net_loop_last_protocol = BOOTP;

  static void nc_wait_arp_handler(uchar *pkt, unsigned dest,

  				 struct in_addr sip, unsigned src,

  				 unsigned len)
  {

  	net_set_state(NETLOOP_SUCCESS); /* got arp reply - quit net loop */

  }

  static void nc_handler(uchar *pkt, unsigned dest, struct in_addr sip,
  		       unsigned src, unsigned len)

  {

  	if (input_size)

  		net_set_state(NETLOOP_SUCCESS); /* got input - quit net loop */

  }

  static void nc_timeout_handler(void)

  {

  	net_set_state(NETLOOP_SUCCESS);

  }

  static int is_broadcast(struct in_addr ip)

  {

  	static struct in_addr netmask;
  	static struct in_addr our_ip;

  	static int env_changed_id;

  	int env_id = env_get_id();

  
  	/* update only when the environment has changed */
  	if (env_changed_id != env_id) {

  		netmask = env_get_ip("netmask");
  		our_ip = env_get_ip("ipaddr");

  
  		env_changed_id = env_id;
  	}

  	return (ip.s_addr == ~0 || /* 255.255.255.255 (global bcast) */
  		((netmask.s_addr & our_ip.s_addr) ==
  		 (netmask.s_addr & ip.s_addr) && /* on the same net and */
  		 (netmask.s_addr | ip.s_addr) == ~0)); /* bcast to our net */

  }
  
  static int refresh_settings_from_env(void)
  {
  	const char *p;
  	static int env_changed_id;

  	int env_id = env_get_id();

  
  	/* update only when the environment has changed */
  	if (env_changed_id != env_id) {

  		if (env_get("ncip")) {

  			nc_ip = env_get_ip("ncip");

  			if (!nc_ip.s_addr)

  				return -1;	/* ncip is 0.0.0.0 */

  			p = strchr(env_get("ncip"), ':');

  			if (p != NULL) {
  				nc_out_port = simple_strtoul(p + 1, NULL, 10);
  				nc_in_port = nc_out_port;
  			}

  		} else {

  			nc_ip.s_addr = ~0; /* ncip is not set, so broadcast */

  		}

  		p = env_get("ncoutport");

  		if (p != NULL)
  			nc_out_port = simple_strtoul(p, NULL, 10);

  		p = env_get("ncinport");

  		if (p != NULL)
  			nc_in_port = simple_strtoul(p, NULL, 10);
  
  		if (is_broadcast(nc_ip))
  			/* broadcast MAC address */
  			memset(nc_ether, 0xff, sizeof(nc_ether));
  		else
  			/* force arp request */
  			memset(nc_ether, 0, sizeof(nc_ether));
  	}
  	return 0;
  }
  
  /**

   * Called from net_loop in net/net.c before each packet

   */

  void nc_start(void)

  {

  	refresh_settings_from_env();

  	if (!output_packet_len || memcmp(nc_ether, net_null_ethaddr, 6)) {

  		/* going to check for input packet */

  		net_set_udp_handler(nc_handler);

  		net_set_timeout_handler(net_timeout, nc_timeout_handler);

  	} else {
  		/* send arp request */

  		uchar *pkt;

  		net_set_arp_handler(nc_wait_arp_handler);

  		pkt = (uchar *)net_tx_packet + net_eth_hdr_size() +
  			IP_UDP_HDR_SIZE;

  		memcpy(pkt, output_packet, output_packet_len);

  		net_send_udp_packet(nc_ether, nc_ip, nc_out_port, nc_in_port,
  				    output_packet_len);

  	}
  }

  int nc_input_packet(uchar *pkt, struct in_addr src_ip, unsigned dest_port,

  	unsigned src_port, unsigned len)

  {

  	int end, chunk;

  	if (dest_port != nc_in_port || !len)

  		return 0; /* not for us */

  	if (src_ip.s_addr != nc_ip.s_addr && !is_broadcast(nc_ip))

  		return 0; /* not from our client */

  	debug_cond(DEBUG_DEV_PKT, "input: \"%*.*s\"
  ", len, len, pkt);

  	if (input_size == sizeof(input_buffer))
  		return 1; /* no space */
  	if (len > sizeof(input_buffer) - input_size)
  		len = sizeof(input_buffer) - input_size;

  
  	end = input_offset + input_size;

  	if (end >= sizeof(input_buffer))

  		end -= sizeof(input_buffer);

  
  	chunk = len;

  	/* Check if packet will wrap in input_buffer */
  	if (end + len >= sizeof(input_buffer)) {

  		chunk = sizeof(input_buffer) - end;

  		/* Copy the second part of the pkt to start of input_buffer */

  		memcpy(input_buffer, pkt + chunk, len - chunk);
  	}

  	/* Copy first (or only) part of pkt after end of current valid input*/

  	memcpy(input_buffer + end, pkt, chunk);

  
  	input_size += len;

  	return 1;
  }

  static void nc_send_packet(const char *buf, int len)

  {

  #ifdef CONFIG_DM_ETH
  	struct udevice *eth;
  #else

  	struct eth_device *eth;

  #endif

  	int inited = 0;
  	uchar *pkt;

  	uchar *ether;

  	struct in_addr ip;

  	debug_cond(DEBUG_DEV_PKT, "output: \"%*.*s\"
  ", len, len, buf);

  	eth = eth_get_dev();
  	if (eth == NULL)

  		return;

  	if (!memcmp(nc_ether, net_null_ethaddr, 6)) {

  		if (eth_is_active(eth))

  			return;	/* inside net loop */
  		output_packet = buf;
  		output_packet_len = len;

  		input_recursion = 1;

  		net_loop(NETCONS); /* wait for arp reply and send packet */

  		input_recursion = 0;

  		output_packet_len = 0;

  		return;
  	}

  	if (!eth_is_active(eth)) {

  		if (eth_is_on_demand_init()) {

  			if (eth_init() < 0)

  				return;
  			eth_set_last_protocol(NETCONS);

  		} else {

  			eth_init_state_only();

  		}

  		inited = 1;
  	}

  	pkt = (uchar *)net_tx_packet + net_eth_hdr_size() + IP_UDP_HDR_SIZE;

  	memcpy(pkt, buf, len);

  	ether = nc_ether;
  	ip = nc_ip;

  	net_send_udp_packet(ether, ip, nc_out_port, nc_in_port, len);

  	if (inited) {
  		if (eth_is_on_demand_init())
  			eth_halt();
  		else
  			eth_halt_state_only();
  	}

  }

  static int nc_stdio_start(struct stdio_dev *dev)

  {

  	int retval;

  	nc_out_port = 6666; /* default port */
  	nc_in_port = nc_out_port;

  	retval = refresh_settings_from_env();
  	if (retval != 0)
  		return retval;

  	/*
  	 * Initialize the static IP settings and buffer pointers

  	 * incase we call net_send_udp_packet before net_loop

  	 */
  	net_init();

  	return 0;

  }

  static void nc_stdio_putc(struct stdio_dev *dev, char c)

  {
  	if (output_recursion)
  		return;
  	output_recursion = 1;

  	nc_send_packet(&c, 1);

  
  	output_recursion = 0;
  }

  static void nc_stdio_puts(struct stdio_dev *dev, const char *s)

  {

  	int len;

  	if (output_recursion)
  		return;
  	output_recursion = 1;

  	len = strlen(s);
  	while (len) {

  		int send_len = min(len, (int)sizeof(input_buffer));

  		nc_send_packet(s, send_len);
  		len -= send_len;
  		s += send_len;
  	}

  
  	output_recursion = 0;
  }

  static int nc_stdio_getc(struct stdio_dev *dev)

  {

  	uchar c;

  	input_recursion = 1;
  
  	net_timeout = 0;	/* no timeout */

  	while (!input_size)

  		net_loop(NETCONS);

  
  	input_recursion = 0;

  	c = input_buffer[input_offset++];

  	if (input_offset >= sizeof(input_buffer))
  		input_offset -= sizeof(input_buffer);

  	input_size--;

  	return c;

  }

  static int nc_stdio_tstc(struct stdio_dev *dev)

  {

  #ifdef CONFIG_DM_ETH
  	struct udevice *eth;
  #else

  	struct eth_device *eth;

  #endif

  
  	if (input_recursion)
  		return 0;

  	if (input_size)

  		return 1;

  	eth = eth_get_dev();

  	if (eth_is_active(eth))

  		return 0;	/* inside net loop */
  
  	input_recursion = 1;
  
  	net_timeout = 1;

  	net_loop(NETCONS);	/* kind of poll */

  
  	input_recursion = 0;

  	return input_size != 0;

  }

  int drv_nc_init(void)

  {

  	struct stdio_dev dev;

  	int rc;

  	memset(&dev, 0, sizeof(dev));

  	strcpy(dev.name, "nc");

  	dev.flags = DEV_FLAGS_OUTPUT | DEV_FLAGS_INPUT;

  	dev.start = nc_stdio_start;
  	dev.putc = nc_stdio_putc;
  	dev.puts = nc_stdio_puts;
  	dev.getc = nc_stdio_getc;
  	dev.tstc = nc_stdio_tstc;

  	rc = stdio_register(&dev);

  
  	return (rc == 0) ? 1 : rc;
  }