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

/*

 * (C) Copyright 2004

 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.

 */

#include <command.h>

#include <env.h>

#include <log.h>

#include <stdio_dev.h>

#include <net.h>

#include <vsprintf.h>

#ifndef CFG_NETCONSOLE_BUFFER_SIZE

#define CFG_NETCONSOLE_BUFFER_SIZE 512

#endif

static char input_buffer[CFG_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 = string_to_ip(env_get("netmask"));

    our_ip = string_to_ip(env_get("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) {

    char *tmp = env_get("ncip");

    if (tmp) {

      nc_ip = string_to_ip(tmp);

      if (!nc_ip.s_addr)

        return -1; /* ncip is 0.0.0.0 */

      p = strchr(tmp, ':');

      if (p != NULL) {

        nc_out_port = dectoul(p + 1, NULL);

        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 = dectoul(p, NULL);

    p = env_get("ncinport");

    if (p != NULL)

      nc_in_port = dectoul(p, NULL);

    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\"\n", 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)

{

  struct udevice *eth;

  int inited = 0;

  uchar *pkt;

  uchar *ether;

  struct in_addr ip;

  debug_cond(DEBUG_DEV_PKT, "output: \"%*.*s\"\n", 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)

{

  struct udevice *eth;

  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;

}