/*
 * (C) Copyright 2004
 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

#include <common.h>
#include <command.h>
#include <stdio_dev.h>
#include <net.h>

DECLARE_GLOBAL_DATA_PTR;

static char input_buffer[512];
static int input_size = 0;              /* char count in input buffer */
static int input_offset = 0;            /* offset to valid chars in input buffer */
static int input_recursion = 0;
static int output_recursion = 0;
static int net_timeout;
static uchar nc_ether[6];               /* server enet address */
static IPaddr_t nc_ip;                  /* server ip */
static short nc_port;                   /* source/target port */
static const char *output_packet;       /* used by first send udp */
static int output_packet_len = 0;

static void nc_wait_arp_handler(uchar *pkt, unsigned dest,
                                 IPaddr_t sip, unsigned src,
                                 unsigned len)
{
        NetState = NETLOOP_SUCCESS;     /* got arp reply - quit net loop */
}

static void nc_handler(uchar *pkt, unsigned dest, IPaddr_t sip, unsigned src,
                        unsigned len)
{
        if (input_size)
                NetState = NETLOOP_SUCCESS;     /* got input - quit net loop */
}

static void nc_timeout (void)
{
        NetState = NETLOOP_SUCCESS;
}

void NcStart (void)
{
        if (!output_packet_len || memcmp (nc_ether, NetEtherNullAddr, 6)) {
                /* going to check for input packet */
                NetSetHandler (nc_handler);
                NetSetTimeout (net_timeout, nc_timeout);
        } else {
                /* send arp request */
                uchar *pkt;
                NetSetHandler (nc_wait_arp_handler);
                pkt = (uchar *) NetTxPacket + NetEthHdrSize () + IP_HDR_SIZE;
                memcpy (pkt, output_packet, output_packet_len);
                NetSendUDPPacket (nc_ether, nc_ip, nc_port, nc_port, output_packet_len);
        }
}

int nc_input_packet (uchar * pkt, unsigned dest, unsigned src, unsigned len)
{
        int end, chunk;

        if (dest != nc_port || !len)
                return 0;               /* not for us */

        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;
        if (end + len > sizeof input_buffer) {
                chunk = sizeof input_buffer - end;
                memcpy(input_buffer, pkt + chunk, len - chunk);
        }
        memcpy (input_buffer + end, pkt, chunk);

        input_size += len;

        return 1;
}

static void nc_send_packet (const char *buf, int len)
{
        struct eth_device *eth;
        int inited = 0;
        uchar *pkt;
        uchar *ether;
        IPaddr_t ip;

        if ((eth = eth_get_dev ()) == NULL) {
                return;
        }

        if (!memcmp (nc_ether, NetEtherNullAddr, 6)) {
                if (eth->state == ETH_STATE_ACTIVE)
                        return; /* inside net loop */
                output_packet = buf;
                output_packet_len = len;
                NetLoop (NETCONS);      /* wait for arp reply and send packet */
                output_packet_len = 0;
                return;
        }

        if (eth->state != ETH_STATE_ACTIVE) {
                if (eth_init (gd->bd) < 0)
                        return;
                inited = 1;
        }
        pkt = (uchar *) NetTxPacket + NetEthHdrSize () + IP_HDR_SIZE;
        memcpy (pkt, buf, len);
        ether = nc_ether;
        ip = nc_ip;
        NetSendUDPPacket (ether, ip, nc_port, nc_port, len);

        if (inited)
                eth_halt ();
}

static int nc_start(void)
{
        int netmask, our_ip;

        nc_port = 6666;         /* default port */

        if (getenv ("ncip")) {
                char *p;

                nc_ip = getenv_IPaddr ("ncip");
                if (!nc_ip)
                        return -1;      /* ncip is 0.0.0.0 */
                if ((p = strchr (getenv ("ncip"), ':')) != NULL)
                        nc_port = simple_strtoul (p + 1, NULL, 10);
        } else
                nc_ip = ~0;             /* ncip is not set */

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

        if (nc_ip == ~0 ||                              /* 255.255.255.255 */
            ((netmask & our_ip) == (netmask & nc_ip) && /* on the same net */
            (netmask | nc_ip) == ~0))                   /* broadcast to our net */
                memset (nc_ether, 0xff, sizeof nc_ether);
        else
                memset (nc_ether, 0, sizeof nc_ether);  /* force arp request */

        return 0;
}

static void nc_putc(char c)
{
        if (output_recursion)
                return;
        output_recursion = 1;

        nc_send_packet (&c, 1);

        output_recursion = 0;
}

static void nc_puts(const char *s)
{
        int len;

        if (output_recursion)
                return;
        output_recursion = 1;

        len = strlen(s);
        while (len) {
                int send_len = min(len, 512);
                nc_send_packet(s, send_len);
                len -= send_len;
                s += send_len;
        }

        output_recursion = 0;
}

static int nc_getc(void)
{
        uchar c;

        input_recursion = 1;

        net_timeout = 0;        /* no timeout */
        while (!input_size)
                NetLoop (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_tstc(void)
{
        struct eth_device *eth;

        if (input_recursion)
                return 0;

        if (input_size)
                return 1;

        eth = eth_get_dev ();
        if (eth && eth->state == ETH_STATE_ACTIVE)
                return 0;       /* inside net loop */

        input_recursion = 1;

        net_timeout = 1;
        NetLoop (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_FLAGS_SYSTEM;
        dev.start = nc_start;
        dev.putc = nc_putc;
        dev.puts = nc_puts;
        dev.getc = nc_getc;
        dev.tstc = nc_tstc;

        rc = stdio_register (&dev);

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