/**
 * \defgroup uip The uIP TCP/IP stack
 * @{
 *
 * uIP is an implementation of the TCP/IP protocol stack intended for
 * small 8-bit and 16-bit microcontrollers.
 *
 * uIP provides the necessary protocols for Internet communication,
 * with a very small code footprint and RAM requirements - the uIP
 * code size is on the order of a few kilobytes and RAM usage is on
 * the order of a few hundred bytes.
 */

/**
 * \file
 * The uIP TCP/IP stack code.
 * \author Adam Dunkels <adam@dunkels.com>
 */

/*
 * Copyright (c) 2001-2003, Adam Dunkels.
 * 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 uIP TCP/IP stack.
 *
 * $Id: uip.c,v 1.65 2006/06/11 21:46:39 adam Exp $
 *
 */

/*
 * uIP is a small implementation of the IP, UDP and TCP protocols (as
 * well as some basic ICMP stuff). The implementation couples the IP,
 * UDP, TCP and the application layers very tightly. To keep the size
 * of the compiled code down, this code frequently uses the goto
 * statement. While it would be possible to break the uip_process()
 * function into many smaller functions, this would increase the code
 * size because of the overhead of parameter passing and the fact that
 * the optimier would not be as efficient.
 *
 * The principle is that we have a small buffer, called the uip_buf,
 * in which the device driver puts an incoming packet. The TCP/IP
 * stack parses the headers in the packet, and calls the
 * application. If the remote host has sent data to the application,
 * this data is present in the uip_buf and the application read the
 * data from there. It is up to the application to put this data into
 * a byte stream if needed. The application will not be fed with data
 * that is out of sequence.
 *
 * If the application whishes to send data to the peer, it should put
 * its data into the uip_buf. The uip_appdata pointer points to the
 * first available byte. The TCP/IP stack will calculate the
 * checksums, and fill in the necessary header fields and finally send
 * the packet back to the peer.
 */

#include "uip.h"
#include "uip_arch.h"

#if (UIP_USE_DEBUG == pdON)
#include "stdio_uc.h"
#endif

#if UIP_CONF_IPV6
#include "uip-neighbor.h"
#endif /* UIP_CONF_IPV6 */

#include <string.h>

/*---------------------------------------------------------------------------*/
/* Variable definitions. */

/* The IP address of this host. If it is defined to be fixed (by
 setting UIP_FIXEDADDR to 1 in uipopt.h), the address is set
 here. Otherwise, the address */
#if UIP_FIXEDADDR > 0
const uip_ipaddr_t uip_hostaddr =
{	HTONS((UIP_IPADDR0 << 8) | UIP_IPADDR1),
	HTONS((UIP_IPADDR2 << 8) | UIP_IPADDR3)};
const uip_ipaddr_t uip_draddr =
{	HTONS((UIP_DRIPADDR0 << 8) | UIP_DRIPADDR1),
	HTONS((UIP_DRIPADDR2 << 8) | UIP_DRIPADDR3)};
const uip_ipaddr_t uip_netmask =
{	HTONS((UIP_NETMASK0 << 8) | UIP_NETMASK1),
	HTONS((UIP_NETMASK2 << 8) | UIP_NETMASK3)};
#else
uip_ipaddr_t uip_hostaddr, uip_draddr, uip_netmask;
#endif /* UIP_FIXEDADDR */

static const uip_ipaddr_t all_ones_addr =
#if UIP_CONF_IPV6
		{	0xffff,0xffff,0xffff,0xffff,0xffff,0xffff,0xffff,0xffff};
#else /* UIP_CONF_IPV6 */
		{ 0xffff, 0xffff };
#endif /* UIP_CONF_IPV6 */
static const uip_ipaddr_t all_zeroes_addr =
#if UIP_CONF_IPV6
		{	0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000};
#else /* UIP_CONF_IPV6 */
		{ 0x0000, 0x0000 };
#endif /* UIP_CONF_IPV6 */

#if UIP_FIXEDETHADDR
const struct uip_eth_addr uip_ethaddr = { {UIP_ETHADDR0,
		UIP_ETHADDR1,
		UIP_ETHADDR2,
		UIP_ETHADDR3,
		UIP_ETHADDR4,
		UIP_ETHADDR5}};
#else
struct uip_eth_addr uip_ethaddr = { { 0, 0, 0, 0, 0, 0 } };
#endif

#ifndef UIP_CONF_EXTERNAL_BUFFER
u8 uip_buf[UIP_BUFSIZE + 2]; /* The packet buffer that contains
 incoming packets. */
#endif /* UIP_CONF_EXTERNAL_BUFFER */

void *uip_appdata; /* The uip_appdata pointer points to
 application data. */
void *uip_sappdata; /* The uip_appdata pointer points to
 the application data which is to
 be sent. */
#if UIP_URGDATA > 0
void *uip_urgdata; /* The uip_urgdata pointer points to
 urgent data (out-of-band data), if
 present. */
u16 uip_urglen, uip_surglen;
#endif /* UIP_URGDATA > 0 */

u16 uip_len, uip_slen;
/* The uip_len is either 8 or 16 bits,
 depending on the maximum packet
 size. */

u8 uip_flags; /* The uip_flags variable is used for
 communication between the TCP/IP stack
 and the application program. */
struct uip_conn *uip_conn; /* uip_conn always points to the current
 connection. */

struct uip_conn uip_conns[UIP_CONNS];
/* The uip_conns array holds all TCP
 connections. */
u16 uip_listenports[UIP_LISTENPORTS];
/* The uip_listenports list all currently
 listning ports. */
#if UIP_UDP
struct uip_udp_conn *uip_udp_conn;
struct uip_udp_conn uip_udp_conns[UIP_UDP_CONNS];
#endif /* UIP_UDP */

static u16 ipid; /* Ths ipid variable is an increasing
 number that is used for the IP ID
 field. */

void uip_setipid(u16 id) {
	ipid = id;
}

static u8 iss[4]; /* The iss variable is used for the TCP
 initial sequence number. */

#if UIP_ACTIVE_OPEN
static u16 lastport; /* Keeps track of the last port used for
 a new connection. */
#endif /* UIP_ACTIVE_OPEN */

/* Temporary variables. */
u8 uip_acc32[4];
static u8 c, opt;
static u16 tmp16;

/* Structures and definitions. */
#define TCP_FIN 0x01
#define TCP_SYN 0x02
#define TCP_RST 0x04
#define TCP_PSH 0x08
#define TCP_ACK 0x10
#define TCP_URG 0x20
#define TCP_CTL 0x3f

#define TCP_OPT_END     0   /* End of TCP options list */
#define TCP_OPT_NOOP    1   /* "No-operation" TCP option */
#define TCP_OPT_MSS     2   /* Maximum segment size TCP option */

#define TCP_OPT_MSS_LEN 4   /* Length of TCP MSS option. */

#define ICMP_ECHO_REPLY 0
#define ICMP_ECHO       8

#define ICMP6_ECHO_REPLY             129
#define ICMP6_ECHO                   128
#define ICMP6_NEIGHBOR_SOLICITATION  135
#define ICMP6_NEIGHBOR_ADVERTISEMENT 136

#define ICMP6_FLAG_S (1 << 6)

#define ICMP6_OPTION_SOURCE_LINK_ADDRESS 1
#define ICMP6_OPTION_TARGET_LINK_ADDRESS 2

/* Macros. */
#define BUF ((struct __attribute__((packed)) uip_tcpip_hdr *)&uip_buf[UIP_LLH_LEN])
#define FBUF ((struct __attribute__((packed)) uip_tcpip_hdr *)&uip_reassbuf[0])
#define ICMPBUF ((struct __attribute__((packed)) uip_icmpip_hdr *)&uip_buf[UIP_LLH_LEN])
#define UDPBUF ((struct __attribute__((packed)) uip_udpip_hdr *)&uip_buf[UIP_LLH_LEN])

#if UIP_STATISTICS == 1
struct uip_stats uip_stat;
#define UIP_STAT(s) s
#else
#define UIP_STAT(s)
#endif /* UIP_STATISTICS == 1 */

#if (UIP_USE_DEBUG == pdON)
#include "stdio_uc.h"
#endif /* UIP_USE_DEBUG == pdON */

#if ! UIP_ARCH_ADD32
void uip_add32(u8 *op32, u16 op16) {
	uip_acc32[3] = op32[3] + (op16 & 0xff);
	uip_acc32[2] = op32[2] + (op16 >> 8);
	uip_acc32[1] = op32[1];
	uip_acc32[0] = op32[0];

	if (uip_acc32[2] < (op16 >> 8)) {
		++uip_acc32[1];
		if (uip_acc32[1] == 0) {
			++uip_acc32[0];
		}
	}

	if (uip_acc32[3] < (op16 & 0xff)) {
		++uip_acc32[2];
		if (uip_acc32[2] == 0) {
			++uip_acc32[1];
			if (uip_acc32[1] == 0) {
				++uip_acc32[0];
			}
		}
	}
}

#endif /* UIP_ARCH_ADD32 */

#if ! UIP_ARCH_CHKSUM
/*---------------------------------------------------------------------------*/
static u16 chksum(u16 sum, const u8 *data, u16 len) {
	u16 t;
	const u8 *dataptr;
	const u8 *last_byte;

	dataptr = data;
	last_byte = data + len - 1;

	while (dataptr < last_byte) { /* At least two more bytes */
		t = (dataptr[0] << 8) + dataptr[1];
		sum += t;
		if (sum < t) {
			sum++; /* carry */
		}
		dataptr += 2;
	}

	if (dataptr == last_byte) {
		t = (dataptr[0] << 8) + 0;
		sum += t;
		if (sum < t) {
			sum++; /* carry */
		}
	}

	/* Return sum in host byte order. */
	return sum;
}
/*---------------------------------------------------------------------------*/
u16 uip_chksum(u16 *data, u16 len) {
	return htons(chksum(0, (u8 *) data, len));
}
/*---------------------------------------------------------------------------*/
#ifndef UIP_ARCH_IPCHKSUM
u16 uip_ipchksum(void) {
	u16 sum;

	sum = chksum(0, &uip_buf[UIP_LLH_LEN], UIP_IPH_LEN);
	#if (UIP_USE_DEBUG == pdON)
	plog("UIP: uip_ipchksum: sum 0x%04x"CMD_TERMINATOR, sum);
	#endif
	return (sum == 0) ? 0xffff : htons(sum);
}
#endif
/*---------------------------------------------------------------------------*/
static u16 upper_layer_chksum(u8 proto) {
	u16 upper_layer_len;
	u16 sum;

#if UIP_CONF_IPV6
	upper_layer_len = (((u16)(BUF->len[0]) << 8) + BUF->len[1]);
#else /* UIP_CONF_IPV6 */
	upper_layer_len = (((u16)(BUF->len[0]) << 8) + BUF->len[1]) - UIP_IPH_LEN;
#endif /* UIP_CONF_IPV6 */

	/* First sum pseudoheader. */

	/* IP protocol and length fields. This addition cannot carry. */
	sum = upper_layer_len + proto;
	/* Sum IP source and destination addresses. */
	sum = chksum(sum, (u8 *) &BUF->srcipaddr[0], 2 * sizeof(uip_ipaddr_t));

	/* Sum TCP header and data. */
	sum = chksum(sum, &uip_buf[UIP_IPH_LEN + UIP_LLH_LEN], upper_layer_len);

	return (sum == 0) ? 0xffff : htons(sum);
}
/*---------------------------------------------------------------------------*/
#if UIP_CONF_IPV6
u16
uip_icmp6chksum(void)
{
	return upper_layer_chksum(UIP_PROTO_ICMP6);

}
#endif /* UIP_CONF_IPV6 */
/*---------------------------------------------------------------------------*/
u16 uip_tcpchksum(void) {
	return upper_layer_chksum(UIP_PROTO_TCP);
}
/*---------------------------------------------------------------------------*/
#if UIP_UDP_CHECKSUMS
u16
uip_udpchksum(void)
{
	return upper_layer_chksum(UIP_PROTO_UDP);
}
#endif /* UIP_UDP_CHECKSUMS */
#endif /* UIP_ARCH_CHKSUM */
/*---------------------------------------------------------------------------*/
void uip_init(void) {
	for (c = 0; c < UIP_LISTENPORTS; ++c) {
		uip_listenports[c] = 0;
	}
	for (c = 0; c < UIP_CONNS; ++c) {
		uip_conns[c].tcpstateflags = UIP_CLOSED;
	}
#if UIP_ACTIVE_OPEN
	lastport = 1024;
#endif /* UIP_ACTIVE_OPEN */

#if UIP_UDP
	for(c = 0; c < UIP_UDP_CONNS; ++c) {
		uip_udp_conns[c].lport = 0;
	}
#endif /* UIP_UDP */

	/* IPv4 initialization. */
#if UIP_FIXEDADDR == 0
	/*  uip_hostaddr[0] = uip_hostaddr[1] = 0;*/
#endif /* UIP_FIXEDADDR */

}
/*---------------------------------------------------------------------------*/
#if UIP_ACTIVE_OPEN
struct uip_conn *
uip_connect(uip_ipaddr_t *ripaddr, u16 rport)
{
	register struct uip_conn *conn, *cconn;

	/* Find an unused local port. */
	again:
	++lastport;

	if(lastport >= 32000) {
		lastport = 4096;
	}

	/* Check if this port is already in use, and if so try to find
	 another one. */
	for(c = 0; c < UIP_CONNS; ++c) {
		conn = &uip_conns[c];
		if(conn->tcpstateflags != UIP_CLOSED &&
				conn->lport == htons(lastport)) {
			goto again;
		}
	}

	conn = 0;
	for(c = 0; c < UIP_CONNS; ++c) {
		cconn = &uip_conns[c];
		if(cconn->tcpstateflags == UIP_CLOSED) {
			conn = cconn;
			break;
		}
		if(cconn->tcpstateflags == UIP_TIME_WAIT) {
			if(conn == 0 ||
					cconn->timer > conn->timer) {
				conn = cconn;
			}
		}
	}

	if(conn == 0) {
		return 0;
	}

	conn->tcpstateflags = UIP_SYN_SENT;

	conn->snd_nxt[0] = iss[0];
	conn->snd_nxt[1] = iss[1];
	conn->snd_nxt[2] = iss[2];
	conn->snd_nxt[3] = iss[3];

	conn->initialmss = conn->mss = UIP_TCP_MSS;

	conn->len = 1; /* TCP length of the SYN is one. */
	conn->nrtx = 0;
	conn->timer = 1; /* Send the SYN next time around. */
	conn->rto = UIP_RTO;
	conn->sa = 0;
	conn->sv = 16; /* Initial value of the RTT variance. */
	conn->lport = htons(lastport);
	conn->rport = rport;
	uip_ipaddr_copy(&conn->ripaddr, ripaddr);

	return conn;
}
#endif /* UIP_ACTIVE_OPEN */
/*---------------------------------------------------------------------------*/
#if UIP_UDP
struct uip_udp_conn *
uip_udp_new(uip_ipaddr_t *ripaddr, u16 rport)
{
	register struct uip_udp_conn *conn;

	/* Find an unused local port. */
	again:
	++lastport;

	if(lastport >= 32000) {
		lastport = 4096;
	}

	for(c = 0; c < UIP_UDP_CONNS; ++c) {
		if(uip_udp_conns[c].lport == htons(lastport)) {
			goto again;
		}
	}

	conn = 0;
	for(c = 0; c < UIP_UDP_CONNS; ++c) {
		if(uip_udp_conns[c].lport == 0) {
			conn = &uip_udp_conns[c];
			break;
		}
	}

	if(conn == 0) {
		return 0;
	}

	conn->lport = HTONS(lastport);
	conn->rport = rport;
	if(ripaddr == NULL) {
		memset(conn->ripaddr, 0, sizeof(uip_ipaddr_t));
	} else {
		uip_ipaddr_copy(&conn->ripaddr, ripaddr);
	}
	conn->ttl = UIP_TTL;

	return conn;
}
#endif /* UIP_UDP */
/*---------------------------------------------------------------------------*/
void uip_unlisten(u16 port) {
	for (c = 0; c < UIP_LISTENPORTS; ++c) {
		if (uip_listenports[c] == port) {
			uip_listenports[c] = 0;
			return;
		}
	}
}
/*---------------------------------------------------------------------------*/
void uip_listen(u16 port) {
	for (c = 0; c < UIP_LISTENPORTS; ++c) {
		if (uip_listenports[c] == 0) {
			uip_listenports[c] = port;
			return;
		}
	}
}
/*---------------------------------------------------------------------------*/
/* XXX: IP fragment reassembly: not well-tested. */

#if UIP_REASSEMBLY && !UIP_CONF_IPV6
#define UIP_REASS_BUFSIZE (UIP_BUFSIZE - UIP_LLH_LEN)
static u8 uip_reassbuf[UIP_REASS_BUFSIZE];
static u8 uip_reassbitmap[UIP_REASS_BUFSIZE / (8 * 8)];
static const u8 bitmap_bits[8] = {0xff, 0x7f, 0x3f, 0x1f,
	0x0f, 0x07, 0x03, 0x01};
static u16 uip_reasslen;
static u8 uip_reassflags;
#define UIP_REASS_FLAG_LASTFRAG 0x01
static u8 uip_reasstmr;

#define IP_MF   0x20

static u8
uip_reass(void)
{
	u16 offset, len;
	u16 i;

	/* If ip_reasstmr is zero, no packet is present in the buffer, so we
	 write the IP header of the fragment into the reassembly
	 buffer. The timer is updated with the maximum age. */
	if(uip_reasstmr == 0) {
		memcpy(uip_reassbuf, &BUF->vhl, UIP_IPH_LEN);
		uip_reasstmr = UIP_REASS_MAXAGE;
		uip_reassflags = 0;
		/* Clear the bitmap. */
		memset(uip_reassbitmap, 0, sizeof(uip_reassbitmap));
	}

	/* Check if the incoming fragment matches the one currently present
	 in the reasembly buffer. If so, we proceed with copying the
	 fragment into the buffer. */
	if(BUF->srcipaddr[0] == FBUF->srcipaddr[0] &&
			BUF->srcipaddr[1] == FBUF->srcipaddr[1] &&
			BUF->destipaddr[0] == FBUF->destipaddr[0] &&
			BUF->destipaddr[1] == FBUF->destipaddr[1] &&
			BUF->ipid[0] == FBUF->ipid[0] &&
			BUF->ipid[1] == FBUF->ipid[1]) {

		len = (BUF->len[0] << 8) + BUF->len[1] - (BUF->vhl & 0x0f) * 4;
		offset = (((BUF->ipoffset[0] & 0x3f) << 8) + BUF->ipoffset[1]) * 8;

		/* If the offset or the offset + fragment length overflows the
		 reassembly buffer, we discard the entire packet. */
		if(offset > UIP_REASS_BUFSIZE ||
				offset + len > UIP_REASS_BUFSIZE) {
			uip_reasstmr = 0;
			goto nullreturn;
		}

		/* Copy the fragment into the reassembly buffer, at the right
		 offset. */
		memcpy(&uip_reassbuf[UIP_IPH_LEN + offset],
				(char *)BUF + (int)((BUF->vhl & 0x0f) * 4),
				len);

		/* Update the bitmap. */
		if(offset / (8 * 8) == (offset + len) / (8 * 8)) {
			/* If the two endpoints are in the same byte, we only update
			 that byte. */

			uip_reassbitmap[offset / (8 * 8)] |=
			bitmap_bits[(offset / 8 ) & 7] &
			~bitmap_bits[((offset + len) / 8 ) & 7];
		} else {
			/* If the two endpoints are in different bytes, we update the
			 bytes in the endpoints and fill the stuff inbetween with
			 0xff. */
			uip_reassbitmap[offset / (8 * 8)] |=
			bitmap_bits[(offset / 8 ) & 7];
			for(i = 1 + offset / (8 * 8); i < (offset + len) / (8 * 8); ++i) {
				uip_reassbitmap[i] = 0xff;
			}
			uip_reassbitmap[(offset + len) / (8 * 8)] |=
			~bitmap_bits[((offset + len) / 8 ) & 7];
		}

		/* If this fragment has the More Fragments flag set to zero, we
		 know that this is the last fragment, so we can calculate the
		 size of the entire packet. We also set the
		 IP_REASS_FLAG_LASTFRAG flag to indicate that we have received
		 the final fragment. */

		if((BUF->ipoffset[0] & IP_MF) == 0) {
			uip_reassflags |= UIP_REASS_FLAG_LASTFRAG;
			uip_reasslen = offset + len;
		}

		/* Finally, we check if we have a full packet in the buffer. We do
		 this by checking if we have the last fragment and if all bits
		 in the bitmap are set. */
		if(uip_reassflags & UIP_REASS_FLAG_LASTFRAG) {
			/* Check all bytes up to and including all but the last byte in
			 the bitmap. */
			for(i = 0; i < uip_reasslen / (8 * 8) - 1; ++i) {
				if(uip_reassbitmap[i] != 0xff) {
					goto nullreturn;
				}
			}
			/* Check the last byte in the bitmap. It should contain just the
			 right amount of bits. */
			if(uip_reassbitmap[uip_reasslen / (8 * 8)] !=
					(u8)~bitmap_bits[uip_reasslen / 8 & 7]) {
				goto nullreturn;
			}

			/* If we have come this far, we have a full packet in the
			 buffer, so we allocate a pbuf and copy the packet into it. We
			 also reset the timer. */
			uip_reasstmr = 0;
			memcpy(BUF, FBUF, uip_reasslen);

			/* Pretend to be a "normal" (i.e., not fragmented) IP packet
			 from now on. */
			BUF->ipoffset[0] = BUF->ipoffset[1] = 0;
			BUF->len[0] = uip_reasslen >> 8;
			BUF->len[1] = uip_reasslen & 0xff;
			BUF->ipchksum = 0;
			BUF->ipchksum = ~(uip_ipchksum());

			return uip_reasslen;
		}
	}

	nullreturn:
	return 0;
}
#endif /* UIP_REASSEMBLY */
/*---------------------------------------------------------------------------*/
static void uip_add_rcv_nxt(u16 n) {
	uip_add32(uip_conn->rcv_nxt, n);
	uip_conn->rcv_nxt[0] = uip_acc32[0];
	uip_conn->rcv_nxt[1] = uip_acc32[1];
	uip_conn->rcv_nxt[2] = uip_acc32[2];
	uip_conn->rcv_nxt[3] = uip_acc32[3];
}
/*---------------------------------------------------------------------------*/
void uip_process(u8 flag) {
	register struct uip_conn *uip_connr = uip_conn;

#if UIP_UDP
	if(flag == UIP_UDP_SEND_CONN) {
		goto udp_send;
	}
#endif /* UIP_UDP */

	uip_sappdata = uip_appdata = &uip_buf[UIP_IPTCPH_LEN + UIP_LLH_LEN];

	/* Check if we were invoked because of a poll request for a
	 particular connection. */
	if (flag == UIP_POLL_REQUEST) {
		if ((uip_connr->tcpstateflags & UIP_TS_MASK) == UIP_ESTABLISHED
				&& !uip_outstanding(uip_connr)) {
			uip_flags = UIP_POLL;
			UIP_APPCALL();
			goto appsend;
		}
		goto drop;

		/* Check if we were invoked because of the perodic timer fireing. */
	} else if (flag == UIP_TIMER) {
#if UIP_REASSEMBLY
		if(uip_reasstmr != 0) {
			--uip_reasstmr;
		}
#endif /* UIP_REASSEMBLY */
		/* Increase the initial sequence number. */
		if (++iss[3] == 0) {
			if (++iss[2] == 0) {
				if (++iss[1] == 0) {
					++iss[0];
				}
			}
		}

		/* Reset the length variables. */
		uip_len = 0;
		uip_slen = 0;

		/* Check if the connection is in a state in which we simply wait
		 for the connection to time out. If so, we increase the
		 connection's timer and remove the connection if it times
		 out. */
		if (uip_connr->tcpstateflags == UIP_TIME_WAIT
				|| uip_connr->tcpstateflags == UIP_FIN_WAIT_2) {
			++(uip_connr->timer);
			if (uip_connr->timer == UIP_TIME_WAIT_TIMEOUT) {
				uip_connr->tcpstateflags = UIP_CLOSED;
			}
		} else if (uip_connr->tcpstateflags != UIP_CLOSED) {
			/* If the connection has outstanding data, we increase the
			 connection's timer and see if it has reached the RTO value
			 in which case we retransmit. */
			if (uip_outstanding(uip_connr)) {
				if (uip_connr->timer-- == 0) {
					if (uip_connr->nrtx == UIP_MAXRTX
							|| ((uip_connr->tcpstateflags == UIP_SYN_SENT
									|| uip_connr->tcpstateflags == UIP_SYN_RCVD)
									&& uip_connr->nrtx == UIP_MAXSYNRTX)) {
						uip_connr->tcpstateflags = UIP_CLOSED;

						/* We call UIP_APPCALL() with uip_flags set to
						 UIP_TIMEDOUT to inform the application that the
						 connection has timed out. */
						uip_flags = UIP_TIMEDOUT;
						UIP_APPCALL();

						/* We also send a reset packet to the remote host. */BUF->flags =
								TCP_RST | TCP_ACK;
						goto tcp_send_nodata;
					}

					/* Exponential backoff. */
					uip_connr->timer = UIP_RTO
							<< (uip_connr->nrtx > 4 ? 4 : uip_connr->nrtx);
					++(uip_connr->nrtx);

					/* Ok, so we need to retransmit. We do this differently
					 depending on which state we are in. In ESTABLISHED, we
					 call upon the application so that it may prepare the
					 data for the retransmit. In SYN_RCVD, we resend the
					 SYNACK that we sent earlier and in LAST_ACK we have to
					 retransmit our FINACK. */
					UIP_STAT(++uip_stat.tcp.rexmit);
					switch (uip_connr->tcpstateflags & UIP_TS_MASK) {
					case UIP_SYN_RCVD:
						/* In the SYN_RCVD state, we should retransmit our
						 SYNACK. */
						goto tcp_send_synack;

#if UIP_ACTIVE_OPEN
						case UIP_SYN_SENT:
						/* In the SYN_SENT state, we retransmit out SYN. */
						BUF->flags = 0;
						goto tcp_send_syn;
#endif /* UIP_ACTIVE_OPEN */

					case UIP_ESTABLISHED:
						/* In the ESTABLISHED state, we call upon the application
						 to do the actual retransmit after which we jump into
						 the code for sending out the packet (the apprexmit
						 label). */
						uip_flags = UIP_REXMIT;
						UIP_APPCALL();
						goto apprexmit;

					case UIP_FIN_WAIT_1:
					case UIP_CLOSING:
					case UIP_LAST_ACK:
						/* In all these states we should retransmit a FINACK. */
						goto tcp_send_finack;

					}
				}
			} else if ((uip_connr->tcpstateflags & UIP_TS_MASK)
					== UIP_ESTABLISHED) {
				/* If there was no need for a retransmission, we poll the
				 application for new data. */
				uip_flags = UIP_POLL;
				UIP_APPCALL();
				goto appsend;
			}
		}
		goto drop;
	}
#if UIP_UDP
	if(flag == UIP_UDP_TIMER) {
		if(uip_udp_conn->lport != 0) {
			uip_conn = NULL;
			uip_sappdata = uip_appdata = &uip_buf[UIP_LLH_LEN + UIP_IPUDPH_LEN];
			uip_len = uip_slen = 0;
			uip_flags = UIP_POLL;
			UIP_UDP_APPCALL();
			goto udp_send;
		} else {
			goto drop;
		}
	}
#endif

	/* This is where the input processing starts. */
	UIP_STAT(++uip_stat.ip.recv);

	/* Start of IP input header processing code. */

#if UIP_CONF_IPV6
	/* Check validity of the IP header. */
	if((BUF->vtc & 0xf0) != 0x60) { /* IP version and header length. */
		UIP_STAT(++uip_stat.ip.drop);
		UIP_STAT(++uip_stat.ip.vhlerr);
		#if (UIP_USE_DEBUG == pdON)
		plog("UIP: ipv6: invalid version."CMD_TERMINATOR);
		#endif
		goto drop;
	}
#else /* UIP_CONF_IPV6 */
	/* Check validity of the IP header. */
	if (BUF->vhl != 0x45) { /* IP version and header length. */
		UIP_STAT(++uip_stat.ip.drop); UIP_STAT(++uip_stat.ip.vhlerr);
		#if (UIP_USE_DEBUG == pdON)
		plog("UIP: ip: invalid version or header length."CMD_TERMINATOR);
		#endif
		goto drop;
	}
#endif /* UIP_CONF_IPV6 */

	/* Check the size of the packet. If the size reported to us in
	 uip_len is smaller the size reported in the IP header, we assume
	 that the packet has been corrupted in transit. If the size of
	 uip_len is larger than the size reported in the IP packet header,
	 the packet has been padded and we set uip_len to the correct
	 value.. */

	if ((BUF->len[0] << 8) + BUF->len[1] <= uip_len) {
		uip_len = (BUF->len[0] << 8) + BUF->len[1];
#if UIP_CONF_IPV6
		uip_len += 40; /* The length reported in the IPv6 header is the
		 length of the payload that follows the
		 header. However, uIP uses the uip_len variable
		 for holding the size of the entire packet,
		 including the IP header. For IPv4 this is not a
		 problem as the length field in the IPv4 header
		 contains the length of the entire packet. But
		 for IPv6 we need to add the size of the IPv6
		 header (40 bytes). */
#endif /* UIP_CONF_IPV6 */
	} else {
		#if (UIP_USE_DEBUG == pdON)
		plog("UIP: ip: packet shorter than reported in IP header."CMD_TERMINATOR);
		#endif
		goto drop;
	}

#if !UIP_CONF_IPV6
	/* Check the fragment flag. */
	if ((BUF->ipoffset[0] & 0x3f) != 0 || BUF->ipoffset[1] != 0) {
#if UIP_REASSEMBLY
		uip_len = uip_reass();
		if(uip_len == 0) {
			goto drop;
		}
#else /* UIP_REASSEMBLY */
		UIP_STAT(++uip_stat.ip.drop); UIP_STAT(++uip_stat.ip.fragerr);
#if (UIP_USE_DEBUG == pdON)
		plog("UIP: ip: fragment dropped."CMD_TERMINATOR);
#endif
		goto drop;
#endif /* UIP_REASSEMBLY */
	}
#endif /* UIP_CONF_IPV6 */

	if (uip_ipaddr_cmp(uip_hostaddr, all_zeroes_addr)) {
		/* If we are configured to use ping IP address configuration and
		 hasn't been assigned an IP address yet, we accept all ICMP
		 packets. */
#if UIP_PINGADDRCONF && !UIP_CONF_IPV6
		if(BUF->proto == UIP_PROTO_ICMP) {
#if (UIP_USE_DEBUG == pdON)
			plog("UIP: ip: possible ping config packet received."CMD_TERMINATOR);
#endif
			goto icmp_input;
		} else {
#if (UIP_USE_DEBUG == pdON)
			plog("UIP: ip: packet dropped since no address assigned."CMD_TERMINATOR);
#endif
			goto drop;
		}
#endif /* UIP_PINGADDRCONF */

	} else {
		/* If IP broadcast support is configured, we check for a broadcast
		 UDP packet, which may be destined to us. */
#if UIP_BROADCAST
		#if (UIP_USE_DEBUG == pdON)
		plog("UIP: UDP IP checksum 0x%04x"CMD_TERMINATOR, uip_ipchksum());
		#endif
		if(BUF->proto == UIP_PROTO_UDP &&
				uip_ipaddr_cmp(BUF->destipaddr, all_ones_addr)
				/*&&
				 uip_ipchksum() == 0xffff*/) {
			goto udp_input;
		}
#endif /* UIP_BROADCAST */

		/* Check if the packet is destined for our IP address. */
#if !UIP_CONF_IPV6
		if (!uip_ipaddr_cmp(BUF->destipaddr, uip_hostaddr)) {
			UIP_STAT(++uip_stat.ip.drop);
			goto drop;
		}
#else /* UIP_CONF_IPV6 */
		/* For IPv6, packet reception is a little trickier as we need to
		 make sure that we listen to certain multicast addresses (all
		 hosts multicast address, and the solicited-node multicast
		 address) as well. However, we will cheat here and accept all
		 multicast packets that are sent to the ff02::/16 addresses. */
		if(!uip_ipaddr_cmp(BUF->destipaddr, uip_hostaddr) &&
				BUF->destipaddr[0] != HTONS(0xff02)) {
			UIP_STAT(++uip_stat.ip.drop);
			goto drop;
		}
#endif /* UIP_CONF_IPV6 */
	}

#if !UIP_CONF_IPV6
	if (uip_ipchksum() != 0xffff) { /* Compute and check the IP header
	 checksum. */
		UIP_STAT(++uip_stat.ip.drop); UIP_STAT(++uip_stat.ip.chkerr);
#if (UIP_USE_DEBUG == pdON)
		plog("UIP: ip: bad checksum."CMD_TERMINATOR);
#endif
		goto drop;
	}
#endif /* UIP_CONF_IPV6 */

	if (BUF->proto == UIP_PROTO_TCP) { /* Check for TCP packet. If so,
	 proceed with TCP input
	 processing. */
		goto tcp_input;
	}

#if UIP_UDP
	if(BUF->proto == UIP_PROTO_UDP) {
		goto udp_input;
	}
#endif /* UIP_UDP */

#if !UIP_CONF_IPV6
	/* ICMPv4 processing code follows. */
	if (BUF->proto != UIP_PROTO_ICMP) { /* We only allow ICMP packets from
	 here. */
		UIP_STAT(++uip_stat.ip.drop); UIP_STAT(++uip_stat.ip.protoerr);
#if (UIP_USE_DEBUG == pdON)
		plog("UIP: ip: neither tcp nor icmp."CMD_TERMINATOR);
#endif
		goto drop;
	}

#if UIP_PINGADDRCONF
	icmp_input:
#endif /* UIP_PINGADDRCONF */
	UIP_STAT(++uip_stat.icmp.recv);

	/* ICMP echo (i.e., ping) processing. This is simple, we only change
	 the ICMP type from ECHO to ECHO_REPLY and adjust the ICMP
	 checksum before we return the packet. */
	if (ICMPBUF->type != ICMP_ECHO) {
		UIP_STAT(++uip_stat.icmp.drop); UIP_STAT(++uip_stat.icmp.typeerr);
#if (UIP_USE_DEBUG == pdON)
		plog("UIP: icmp: not icmp echo."CMD_TERMINATOR);
#endif
		goto drop;
	}

	/* If we are configured to use ping IP address assignment, we use
	 the destination IP address of this ping packet and assign it to
	 ourself. */
#if UIP_PINGADDRCONF
	if((uip_hostaddr[0] | uip_hostaddr[1]) == 0) {
		uip_hostaddr[0] = BUF->destipaddr[0];
		uip_hostaddr[1] = BUF->destipaddr[1];
	}
#endif /* UIP_PINGADDRCONF */

	ICMPBUF->type = ICMP_ECHO_REPLY;

	if (ICMPBUF->icmpchksum >= HTONS(0xffff - (ICMP_ECHO << 8))) {
		ICMPBUF->icmpchksum += HTONS(ICMP_ECHO << 8) + 1;
	} else {
		ICMPBUF->icmpchksum += HTONS(ICMP_ECHO << 8);
	}

	/* Swap IP addresses. */
	uip_ipaddr_copy(BUF->destipaddr, BUF->srcipaddr);
	uip_ipaddr_copy(BUF->srcipaddr, uip_hostaddr);

	UIP_STAT(++uip_stat.icmp.sent);
	goto send;

	/* End of IPv4 input header processing code. */
#else /* !UIP_CONF_IPV6 */

	/* This is IPv6 ICMPv6 processing code. */
	plog("UIP: icmp6_input: length %d"CMD_TERMINATOR, uip_len);

	if(BUF->proto != UIP_PROTO_ICMP6) { /* We only allow ICMPv6 packets from
	 here. */
		UIP_STAT(++uip_stat.ip.drop);
		UIP_STAT(++uip_stat.ip.protoerr);
#if (UIP_USE_DEBUG == pdON)
		plog("UIP: ip: neither tcp nor icmp6."CMD_TERMINATOR);
#endif
		goto drop;
	}

	UIP_STAT(++uip_stat.icmp.recv);

	/* If we get a neighbor solicitation for our address we should send
	 a neighbor advertisement message back. */
	if(ICMPBUF->type == ICMP6_NEIGHBOR_SOLICITATION) {
		if(uip_ipaddr_cmp(ICMPBUF->icmp6data, uip_hostaddr)) {

			if(ICMPBUF->options[0] == ICMP6_OPTION_SOURCE_LINK_ADDRESS) {
				/* Save the sender's address in our neighbor list. */
				uip_neighbor_add(ICMPBUF->srcipaddr, &(ICMPBUF->options[2]));
			}

			/* We should now send a neighbor advertisement back to where the
			 neighbor solicication came from. */
			ICMPBUF->type = ICMP6_NEIGHBOR_ADVERTISEMENT;
			ICMPBUF->flags = ICMP6_FLAG_S; /* Solicited flag. */

			ICMPBUF->reserved1 = ICMPBUF->reserved2 = ICMPBUF->reserved3 = 0;

			uip_ipaddr_copy(ICMPBUF->destipaddr, ICMPBUF->srcipaddr);
			uip_ipaddr_copy(ICMPBUF->srcipaddr, uip_hostaddr);
			ICMPBUF->options[0] = ICMP6_OPTION_TARGET_LINK_ADDRESS;
			ICMPBUF->options[1] = 1; /* Options length, 1 = 8 bytes. */
			memcpy(&(ICMPBUF->options[2]), &uip_ethaddr, sizeof(uip_ethaddr));
			ICMPBUF->icmpchksum = 0;
			ICMPBUF->icmpchksum = ~uip_icmp6chksum();
			goto send;

		}
		goto drop;
	} else if(ICMPBUF->type == ICMP6_ECHO) {
		/* ICMP echo (i.e., ping) processing. This is simple, we only
		 change the ICMP type from ECHO to ECHO_REPLY and update the
		 ICMP checksum before we return the packet. */

		ICMPBUF->type = ICMP6_ECHO_REPLY;

		uip_ipaddr_copy(BUF->destipaddr, BUF->srcipaddr);
		uip_ipaddr_copy(BUF->srcipaddr, uip_hostaddr);
		ICMPBUF->icmpchksum = 0;
		ICMPBUF->icmpchksum = ~uip_icmp6chksum();

		UIP_STAT(++uip_stat.icmp.sent);
		goto send;
	} else {
		plog("UIP: Unknown icmp6 message type %d"CMD_TERMINATOR, ICMPBUF->type);
		UIP_STAT(++uip_stat.icmp.drop);
		UIP_STAT(++uip_stat.icmp.typeerr);
#if (UIP_USE_DEBUG == pdON)
		plog("UIP: icmp: unknown ICMP message."CMD_TERMINATOR);
#endif
		goto drop;
	}

	/* End of IPv6 ICMP processing. */

#endif /* !UIP_CONF_IPV6 */

#if UIP_UDP
	/* UDP input processing. */
	udp_input:
	/* UDP processing is really just a hack. We don't do anything to the
	 UDP/IP headers, but let the UDP application do all the hard
	 work. If the application sets uip_slen, it has a packet to
	 send. */
#if UIP_UDP_CHECKSUMS
	uip_len = uip_len - UIP_IPUDPH_LEN;
	uip_appdata = &uip_buf[UIP_LLH_LEN + UIP_IPUDPH_LEN];
	if(UDPBUF->udpchksum != 0 && uip_udpchksum() != 0xffff) {
		UIP_STAT(++uip_stat.udp.drop);
		UIP_STAT(++uip_stat.udp.chkerr);
#if (UIP_USE_DEBUG == pdON)
		plog("UIP: udp: bad checksum."CMD_TERMINATOR);
#endif
		goto drop;
	}
#else /* UIP_UDP_CHECKSUMS */
	uip_len = uip_len - UIP_IPUDPH_LEN;
#endif /* UIP_UDP_CHECKSUMS */

	/* Demultiplex this UDP packet between the UDP "connections". */
	for(uip_udp_conn = &uip_udp_conns[0];
			uip_udp_conn < &uip_udp_conns[UIP_UDP_CONNS];
			++uip_udp_conn) {
		/* If the local UDP port is non-zero, the connection is considered
		 to be used. If so, the local port number is checked against the
		 destination port number in the received packet. If the two port
		 numbers match, the remote port number is checked if the
		 connection is bound to a remote port. Finally, if the
		 connection is bound to a remote IP address, the source IP
		 address of the packet is checked. */
		if(uip_udp_conn->lport != 0 &&
				UDPBUF->destport == uip_udp_conn->lport &&
				(uip_udp_conn->rport == 0 ||
						UDPBUF->srcport == uip_udp_conn->rport) &&
				(uip_ipaddr_cmp(uip_udp_conn->ripaddr, all_zeroes_addr) ||
						uip_ipaddr_cmp(uip_udp_conn->ripaddr, all_ones_addr) ||
						uip_ipaddr_cmp(BUF->srcipaddr, uip_udp_conn->ripaddr))) {
			goto udp_found;
		}
	}
#if (UIP_USE_DEBUG == pdON)
	plog("UIP: udp: no matching connection found"CMD_TERMINATOR);
#endif
	goto drop;

	udp_found:
	uip_conn = NULL;
	uip_flags = UIP_NEWDATA;
	uip_sappdata = uip_appdata = &uip_buf[UIP_LLH_LEN + UIP_IPUDPH_LEN];
	uip_slen = 0;
	UIP_UDP_APPCALL();
	udp_send:
	if(uip_slen == 0) {
		goto drop;
	}
	uip_len = uip_slen + UIP_IPUDPH_LEN;

#if UIP_CONF_IPV6
	/* For IPv6, the IP length field does not include the IPv6 IP header
	 length. */
	BUF->len[0] = ((uip_len - UIP_IPH_LEN) >> 8);
	BUF->len[1] = ((uip_len - UIP_IPH_LEN) & 0xff);
#else /* UIP_CONF_IPV6 */
	BUF->len[0] = (uip_len >> 8);
	BUF->len[1] = (uip_len & 0xff);
#endif /* UIP_CONF_IPV6 */

	BUF->ttl = uip_udp_conn->ttl;
	BUF->proto = UIP_PROTO_UDP;

	UDPBUF->udplen = HTONS(uip_slen + UIP_UDPH_LEN);
	UDPBUF->udpchksum = 0;

	BUF->srcport = uip_udp_conn->lport;
	BUF->destport = uip_udp_conn->rport;

	uip_ipaddr_copy(BUF->srcipaddr, uip_hostaddr);
	uip_ipaddr_copy(BUF->destipaddr, uip_udp_conn->ripaddr);

	uip_appdata = &uip_buf[UIP_LLH_LEN + UIP_IPTCPH_LEN];

#if UIP_UDP_CHECKSUMS
	/* Calculate UDP checksum. */
	UDPBUF->udpchksum = ~(uip_udpchksum());
	if(UDPBUF->udpchksum == 0) {
		UDPBUF->udpchksum = 0xffff;
	}
#endif /* UIP_UDP_CHECKSUMS */

	goto ip_send_nolen;
#endif /* UIP_UDP */

	/* TCP input processing. */
	tcp_input: UIP_STAT(++uip_stat.tcp.recv);

	/* Start of TCP input header processing code. */
	if (uip_tcpchksum() != 0xffff) { /* Compute and check the TCP
	 checksum. */
		UIP_STAT(++uip_stat.tcp.drop); UIP_STAT(++uip_stat.tcp.chkerr);
#if (UIP_USE_DEBUG == pdON)
		plog("UIP: tcp: bad checksum."CMD_TERMINATOR);
#endif
		goto drop;
	}

	/* Demultiplex this segment. */
	/* First check any active connections. */
	for (uip_connr = &uip_conns[0]; uip_connr <= &uip_conns[UIP_CONNS - 1];
			++uip_connr) {
		if (uip_connr->tcpstateflags != UIP_CLOSED
				&& BUF->destport == uip_connr->lport
				&& BUF->srcport == uip_connr->rport
				&& uip_ipaddr_cmp(BUF->srcipaddr, uip_connr->ripaddr)) {
			goto found;
		}
	}

	/* If we didn't find and active connection that expected the packet,
	 either this packet is an old duplicate, or this is a SYN packet
	 destined for a connection in LISTEN. If the SYN flag isn't set,
	 it is an old packet and we send a RST. */
	if ((BUF->flags & TCP_CTL) != TCP_SYN) {
		goto reset;
	}

	tmp16 = BUF->destport;
	/* Next, check listening connections. */
	for (c = 0; c < UIP_LISTENPORTS; ++c) {
		if (tmp16 == uip_listenports[c])
			goto found_listen;
	}

	/* No matching connection found, so we send a RST packet. */
	UIP_STAT(++uip_stat.tcp.synrst);
	reset:

	/* We do not send resets in response to resets. */
	if (BUF->flags & TCP_RST) {
		goto drop;
	}

	UIP_STAT(++uip_stat.tcp.rst);

	BUF->flags = TCP_RST | TCP_ACK;
	uip_len = UIP_IPTCPH_LEN;
	BUF->tcpoffset = 5 << 4;

	/* Flip the seqno and ackno fields in the TCP header. */
	c = BUF->seqno[3];
	BUF->seqno[3] = BUF->ackno[3];
	BUF->ackno[3] = c;

	c = BUF->seqno[2];
	BUF->seqno[2] = BUF->ackno[2];
	BUF->ackno[2] = c;

	c = BUF->seqno[1];
	BUF->seqno[1] = BUF->ackno[1];
	BUF->ackno[1] = c;

	c = BUF->seqno[0];
	BUF->seqno[0] = BUF->ackno[0];
	BUF->ackno[0] = c;

	/* We also have to increase the sequence number we are
	 acknowledging. If the least significant byte overflowed, we need
	 to propagate the carry to the other bytes as well. */
	if (++BUF->ackno[3] == 0) {
		if (++BUF->ackno[2] == 0) {
			if (++BUF->ackno[1] == 0) {
				++BUF->ackno[0];
			}
		}
	}

	/* Swap port numbers. */
	tmp16 = BUF->srcport;
	BUF->srcport = BUF->destport;
	BUF->destport = tmp16;

	/* Swap IP addresses. */
	uip_ipaddr_copy(BUF->destipaddr, BUF->srcipaddr);
	uip_ipaddr_copy(BUF->srcipaddr, uip_hostaddr);

	/* And send out the RST packet! */
	goto tcp_send_noconn;

	/* This label will be jumped to if we matched the incoming packet
	 with a connection in LISTEN. In that case, we should create a new
	 connection and send a SYNACK in return. */
	found_listen:
	/* First we check if there are any connections avaliable. Unused
	 connections are kept in the same table as used connections, but
	 unused ones have the tcpstate set to CLOSED. Also, connections in
	 TIME_WAIT are kept track of and we'll use the oldest one if no
	 CLOSED connections are found. Thanks to Eddie C. Dost for a very
	 nice algorithm for the TIME_WAIT search. */
	uip_connr = 0;
	for (c = 0; c < UIP_CONNS; ++c) {
		if (uip_conns[c].tcpstateflags == UIP_CLOSED) {
			uip_connr = &uip_conns[c];
			break;
		}
		if (uip_conns[c].tcpstateflags == UIP_TIME_WAIT) {
			if (uip_connr == 0 || uip_conns[c].timer > uip_connr->timer) {
				uip_connr = &uip_conns[c];
			}
		}
	}

	if (uip_connr == 0) {
		/* All connections are used already, we drop packet and hope that
		 the remote end will retransmit the packet at a time when we
		 have more spare connections. */
		UIP_STAT(++uip_stat.tcp.syndrop);
#if (UIP_USE_DEBUG == pdON)
		plog("UIP: tcp: found no unused connections."CMD_TERMINATOR);
#endif
		goto drop;
	}
	uip_conn = uip_connr;

	/* Fill in the necessary fields for the new connection. */
	uip_connr->rto = uip_connr->timer = UIP_RTO;
	uip_connr->sa = 0;
	uip_connr->sv = 4;
	uip_connr->nrtx = 0;
	uip_connr->lport = BUF->destport;
	uip_connr->rport = BUF->srcport;
	uip_ipaddr_copy(uip_connr->ripaddr, BUF->srcipaddr);
	uip_connr->tcpstateflags = UIP_SYN_RCVD;

	uip_connr->snd_nxt[0] = iss[0];
	uip_connr->snd_nxt[1] = iss[1];
	uip_connr->snd_nxt[2] = iss[2];
	uip_connr->snd_nxt[3] = iss[3];
	uip_connr->len = 1;

	/* rcv_nxt should be the seqno from the incoming packet + 1. */
	uip_connr->rcv_nxt[3] = BUF->seqno[3];
	uip_connr->rcv_nxt[2] = BUF->seqno[2];
	uip_connr->rcv_nxt[1] = BUF->seqno[1];
	uip_connr->rcv_nxt[0] = BUF->seqno[0];
	uip_add_rcv_nxt(1);

	/* Parse the TCP MSS option, if present. */
	if ((BUF->tcpoffset & 0xf0) > 0x50) {
		for (c = 0; c < ((BUF->tcpoffset >> 4) - 5) << 2;) {
			opt = uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + c];
			if (opt == TCP_OPT_END) {
				/* End of options. */
				break;
			} else if (opt == TCP_OPT_NOOP) {
				++c;
				/* NOP option. */
			} else if (opt == TCP_OPT_MSS
					&& uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c]
							== TCP_OPT_MSS_LEN) {
				/* An MSS option with the right option length. */
				tmp16 = ((u16) uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 2 + c]
						<< 8)
						| (u16) uip_buf[UIP_IPTCPH_LEN + UIP_LLH_LEN + 3 + c];
				uip_connr->initialmss = uip_connr->mss =
						tmp16 > UIP_TCP_MSS ? UIP_TCP_MSS : tmp16;

				/* And we are done processing options. */
				break;
			} else {
				/* All other options have a length field, so that we easily
				 can skip past them. */
				if (uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c] == 0) {
					/* If the length field is zero, the options are malformed
					 and we don't process them further. */
					break;
				}
				c += uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c];
			}
		}
	}

	/* Our response will be a SYNACK. */
#if UIP_ACTIVE_OPEN
	tcp_send_synack:
	BUF->flags = TCP_ACK;

	tcp_send_syn:
	BUF->flags |= TCP_SYN;
#else /* UIP_ACTIVE_OPEN */
	tcp_send_synack:
	BUF->flags = TCP_SYN | TCP_ACK;
#endif /* UIP_ACTIVE_OPEN */

	/* We send out the TCP Maximum Segment Size option with our
	 SYNACK. */BUF->optdata[0] = TCP_OPT_MSS;
	BUF->optdata[1] = TCP_OPT_MSS_LEN;
	BUF->optdata[2] = (UIP_TCP_MSS) / 256;
	BUF->optdata[3] = (UIP_TCP_MSS) & 255;
	uip_len = UIP_IPTCPH_LEN + TCP_OPT_MSS_LEN;
	BUF->tcpoffset = ((UIP_TCPH_LEN + TCP_OPT_MSS_LEN) / 4) << 4;
	goto tcp_send;

	/* This label will be jumped to if we found an active connection. */
	found: uip_conn = uip_connr;
	uip_flags = 0;
	/* We do a very naive form of TCP reset processing; we just accept
	 any RST and kill our connection. We should in fact check if the
	 sequence number of this reset is wihtin our advertised window
	 before we accept the reset. */
	if (BUF->flags & TCP_RST) {
		uip_connr->tcpstateflags = UIP_CLOSED;
#if (UIP_USE_DEBUG == pdON)
		plog("UIP: tcp: got reset, aborting connection."CMD_TERMINATOR);
#endif
		uip_flags = UIP_ABORT;
		UIP_APPCALL();
		goto drop;
	}
	/* Calculated the length of the data, if the application has sent
	 any data to us. */
	c = (BUF->tcpoffset >> 4) << 2;
	/* uip_len will contain the length of the actual TCP data. This is
	 calculated by subtracing the length of the TCP header (in
	 c) and the length of the IP header (20 bytes). */
	uip_len = uip_len - c - UIP_IPH_LEN;

	/* First, check if the sequence number of the incoming packet is
	 what we're expecting next. If not, we send out an ACK with the
	 correct numbers in. */
	if (!(((uip_connr->tcpstateflags & UIP_TS_MASK) == UIP_SYN_SENT)
			&& ((BUF->flags & TCP_CTL) == (TCP_SYN | TCP_ACK)))) {
		if ((uip_len > 0 || ((BUF->flags & (TCP_SYN | TCP_FIN)) != 0))
				&& (BUF->seqno[0] != uip_connr->rcv_nxt[0]
						|| BUF->seqno[1] != uip_connr->rcv_nxt[1]
						|| BUF->seqno[2] != uip_connr->rcv_nxt[2]
						|| BUF->seqno[3] != uip_connr->rcv_nxt[3])) {
			goto tcp_send_ack;
		}
	}

	/* Next, check if the incoming segment acknowledges any outstanding
	 data. If so, we update the sequence number, reset the length of
	 the outstanding data, calculate RTT estimations, and reset the
	 retransmission timer. */
	if ((BUF->flags & TCP_ACK) && uip_outstanding(uip_connr)) {
		uip_add32(uip_connr->snd_nxt, uip_connr->len);

		if (BUF->ackno[0] == uip_acc32[0] && BUF->ackno[1] == uip_acc32[1]
				&& BUF->ackno[2] == uip_acc32[2]
				&& BUF->ackno[3] == uip_acc32[3]) {
			/* Update sequence number. */
			uip_connr->snd_nxt[0] = uip_acc32[0];
			uip_connr->snd_nxt[1] = uip_acc32[1];
			uip_connr->snd_nxt[2] = uip_acc32[2];
			uip_connr->snd_nxt[3] = uip_acc32[3];

			/* Do RTT estimation, unless we have done retransmissions. */
			if (uip_connr->nrtx == 0) {
				signed char m;
				m = uip_connr->rto - uip_connr->timer;
				/* This is taken directly from VJs original code in his paper */
				m = m - (uip_connr->sa >> 3);
				uip_connr->sa += m;
				if (m < 0) {
					m = -m;
				}
				m = m - (uip_connr->sv >> 2);
				uip_connr->sv += m;
				uip_connr->rto = (uip_connr->sa >> 3) + uip_connr->sv;

			}
			/* Set the acknowledged flag. */
			uip_flags = UIP_ACKDATA;
			/* Reset the retransmission timer. */
			uip_connr->timer = uip_connr->rto;

			/* Reset length of outstanding data. */
			uip_connr->len = 0;
		}

	}

	/* Do different things depending on in what state the connection is. */
	switch (uip_connr->tcpstateflags & UIP_TS_MASK) {
	/* CLOSED and LISTEN are not handled here. CLOSE_WAIT is not
	 implemented, since we force the application to close when the
	 peer sends a FIN (hence the application goes directly from
	 ESTABLISHED to LAST_ACK). */
	case UIP_SYN_RCVD:
		/* In SYN_RCVD we have sent out a SYNACK in response to a SYN, and
		 we are waiting for an ACK that acknowledges the data we sent
		 out the last time. Therefore, we want to have the UIP_ACKDATA
		 flag set. If so, we enter the ESTABLISHED state. */
		if (uip_flags & UIP_ACKDATA) {
			uip_connr->tcpstateflags = UIP_ESTABLISHED;
			uip_flags = UIP_CONNECTED;
			uip_connr->len = 0;
			if (uip_len > 0) {
				uip_flags |= UIP_NEWDATA;
				uip_add_rcv_nxt(uip_len);
			}
			uip_slen = 0;
			UIP_APPCALL();
			goto appsend;
		}
		goto drop;
#if UIP_ACTIVE_OPEN
		case UIP_SYN_SENT:
		/* In SYN_SENT, we wait for a SYNACK that is sent in response to
		 our SYN. The rcv_nxt is set to sequence number in the SYNACK
		 plus one, and we send an ACK. We move into the ESTABLISHED
		 state. */
		if((uip_flags & UIP_ACKDATA) &&
				(BUF->flags & TCP_CTL) == (TCP_SYN | TCP_ACK)) {

			/* Parse the TCP MSS option, if present. */
			if((BUF->tcpoffset & 0xf0) > 0x50) {
				for(c = 0; c < ((BUF->tcpoffset >> 4) - 5) << 2;) {
					opt = uip_buf[UIP_IPTCPH_LEN + UIP_LLH_LEN + c];
					if(opt == TCP_OPT_END) {
						/* End of options. */
						break;
					} else if(opt == TCP_OPT_NOOP) {
						++c;
						/* NOP option. */
					} else if(opt == TCP_OPT_MSS &&
							uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c] == TCP_OPT_MSS_LEN) {
						/* An MSS option with the right option length. */
						tmp16 = (uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 2 + c] << 8) |
						uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 3 + c];
						uip_connr->initialmss =
						uip_connr->mss = tmp16 > UIP_TCP_MSS? UIP_TCP_MSS: tmp16;

						/* And we are done processing options. */
						break;
					} else {
						/* All other options have a length field, so that we easily
						 can skip past them. */
						if(uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c] == 0) {
							/* If the length field is zero, the options are malformed
							 and we don't process them further. */
							break;
						}
						c += uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c];
					}
				}
			}
			uip_connr->tcpstateflags = UIP_ESTABLISHED;
			uip_connr->rcv_nxt[0] = BUF->seqno[0];
			uip_connr->rcv_nxt[1] = BUF->seqno[1];
			uip_connr->rcv_nxt[2] = BUF->seqno[2];
			uip_connr->rcv_nxt[3] = BUF->seqno[3];
			uip_add_rcv_nxt(1);
			uip_flags = UIP_CONNECTED | UIP_NEWDATA;
			uip_connr->len = 0;
			uip_len = 0;
			uip_slen = 0;
			UIP_APPCALL();
			goto appsend;
		}
		/* Inform the application that the connection failed */
		uip_flags = UIP_ABORT;
		UIP_APPCALL();
		/* The connection is closed after we send the RST */
		uip_conn->tcpstateflags = UIP_CLOSED;
		goto reset;
#endif /* UIP_ACTIVE_OPEN */

	case UIP_ESTABLISHED:
		/* In the ESTABLISHED state, we call upon the application to feed
		 data into the uip_buf. If the UIP_ACKDATA flag is set, the
		 application should put new data into the buffer, otherwise we are
		 retransmitting an old segment, and the application should put that
		 data into the buffer.

		 If the incoming packet is a FIN, we should close the connection on
		 this side as well, and we send out a FIN and enter the LAST_ACK
		 state. We require that there is no outstanding data; otherwise the
		 sequence numbers will be screwed up. */

		if (BUF->flags & TCP_FIN && !(uip_connr->tcpstateflags & UIP_STOPPED)) {
			if (uip_outstanding(uip_connr)) {
				goto drop;
			}
			uip_add_rcv_nxt(1 + uip_len);
			uip_flags |= UIP_CLOSE;
			if (uip_len > 0) {
				uip_flags |= UIP_NEWDATA;
			}
			UIP_APPCALL();
			uip_connr->len = 1;
			uip_connr->tcpstateflags = UIP_LAST_ACK;
			uip_connr->nrtx = 0;
			tcp_send_finack:
			BUF->flags = TCP_FIN | TCP_ACK;
			goto tcp_send_nodata;
		}

		/* Check the URG flag. If this is set, the segment carries urgent
		 data that we must pass to the application. */
		if ((BUF->flags & TCP_URG) != 0) {
#if UIP_URGDATA > 0
			uip_urglen = (BUF->urgp[0] << 8) | BUF->urgp[1];
			if(uip_urglen > uip_len) {
				/* There is more urgent data in the next segment to come. */
				uip_urglen = uip_len;
			}
			uip_add_rcv_nxt(uip_urglen);
			uip_len -= uip_urglen;
			uip_urgdata = uip_appdata;
			uip_appdata += uip_urglen;
		} else {
			uip_urglen = 0;
#else /* UIP_URGDATA > 0 */
			uip_appdata = ((char *) uip_appdata)
					+ ((BUF->urgp[0] << 8) | BUF->urgp[1]);
			uip_len -= (BUF->urgp[0] << 8) | BUF->urgp[1];
#endif /* UIP_URGDATA > 0 */
		}

		/* If uip_len > 0 we have TCP data in the packet, and we flag this
		 by setting the UIP_NEWDATA flag and update the sequence number
		 we acknowledge. If the application has stopped the dataflow
		 using uip_stop(), we must not accept any data packets from the
		 remote host. */
		if (uip_len > 0 && !(uip_connr->tcpstateflags & UIP_STOPPED)) {
			uip_flags |= UIP_NEWDATA;
			uip_add_rcv_nxt(uip_len);
		}

		/* Check if the available buffer space advertised by the other end
		 is smaller than the initial MSS for this connection. If so, we
		 set the current MSS to the window size to ensure that the
		 application does not send more data than the other end can
		 handle.

		 If the remote host advertises a zero window, we set the MSS to
		 the initial MSS so that the application will send an entire MSS
		 of data. This data will not be acknowledged by the receiver,
		 and the application will retransmit it. This is called the
		 "persistent timer" and uses the retransmission mechanim.
		 */
		tmp16 = ((u16)BUF->wnd[0] << 8) + (u16)BUF->wnd[1];
		if (tmp16 > uip_connr->initialmss || tmp16 == 0) {
			tmp16 = uip_connr->initialmss;
		}
		uip_connr->mss = tmp16;

		/* If this packet constitutes an ACK for outstanding data (flagged
		 by the UIP_ACKDATA flag, we should call the application since it
		 might want to send more data. If the incoming packet had data
		 from the peer (as flagged by the UIP_NEWDATA flag), the
		 application must also be notified.

		 When the application is called, the global variable uip_len
		 contains the length of the incoming data. The application can
		 access the incoming data through the global pointer
		 uip_appdata, which usually points UIP_IPTCPH_LEN + UIP_LLH_LEN
		 bytes into the uip_buf array.

		 If the application wishes to send any data, this data should be
		 put into the uip_appdata and the length of the data should be
		 put into uip_len. If the application don't have any data to
		 send, uip_len must be set to 0. */
		if (uip_flags & (UIP_NEWDATA | UIP_ACKDATA)) {
			uip_slen = 0;
			UIP_APPCALL();
			#if (UIP_USE_DEBUG == pdON)
			plog("UIP: uip_slen  %u [%u] "CMD_TERMINATOR, uip_slen, __LINE__);
			#endif

			appsend:

			if (uip_flags & UIP_ABORT) {
				uip_slen = 0;
				uip_connr->tcpstateflags = UIP_CLOSED;
				BUF->flags = TCP_RST | TCP_ACK;
				#if (UIP_USE_DEBUG == pdON)
				plog("UIP: uip abort"CMD_TERMINATOR);
				#endif

				goto tcp_send_nodata;
			}

			if (uip_flags & UIP_CLOSE) {
				uip_slen = 0;
				uip_connr->len = 1;
				uip_connr->tcpstateflags = UIP_FIN_WAIT_1;
				uip_connr->nrtx = 0;
				BUF->flags = TCP_FIN | TCP_ACK;
				#if (UIP_USE_DEBUG == pdON)
				plog("UIP: uip close"CMD_TERMINATOR);
				#endif

				goto tcp_send_nodata;
			}

			/* If uip_slen > 0, the application has data to be sent. */
			if (uip_slen > 0) {

				/* If the connection has acknowledged data, the contents of
				 the ->len variable should be discarded. */
				if ((uip_flags & UIP_ACKDATA) != 0) {
					uip_connr->len = 0;
				}

				/* If the ->len variable is non-zero the connection has
				 already data in transit and cannot send anymore right
				 now. */
				if (uip_connr->len == 0) {

					/* The application cannot send more than what is allowed by
					 the mss (the minumum of the MSS and the available
					 window). */
					if (uip_slen > uip_connr->mss) {
						uip_slen = uip_connr->mss;
					}

					/* Remember how much data we send out now so that we know
					 when everything has been acknowledged. */
					uip_connr->len = uip_slen;
				} else {

					/* If the application already had unacknowledged data, we
					 make sure that the application does not send (i.e.,
					 retransmit) out more than it previously sent out. */
					uip_slen = uip_connr->len;
				}
			}
			uip_connr->nrtx = 0;
			apprexmit: uip_appdata = uip_sappdata;

			/* If the application has data to be sent, or if the incoming
			 packet had new data in it, we must send out a packet. */
			if (uip_slen > 0 && uip_connr->len > 0) {
				/* Add the length of the IP and TCP headers. */
				uip_len = uip_connr->len + UIP_TCPIP_HLEN;
				/* We always set the ACK flag in response packets. */BUF->flags =
						TCP_ACK | TCP_PSH;
				/* Send the packet. */
				goto tcp_send_noopts;
			}
			/* If there is no data to send, just send out a pure ACK if
			 there is newdata. */
			if (uip_flags & UIP_NEWDATA) {
				uip_len = UIP_TCPIP_HLEN;
				BUF->flags = TCP_ACK;
				goto tcp_send_noopts;
			}
		}
		goto drop;
	case UIP_LAST_ACK:
		/* We can close this connection if the peer has acknowledged our
		 FIN. This is indicated by the UIP_ACKDATA flag. */
		if (uip_flags & UIP_ACKDATA) {
			uip_connr->tcpstateflags = UIP_CLOSED;
			uip_flags = UIP_CLOSE;
			UIP_APPCALL();
		}
		break;

	case UIP_FIN_WAIT_1:
		/* The application has closed the connection, but the remote host
		 hasn't closed its end yet. Thus we do nothing but wait for a
		 FIN from the other side. */
		if (uip_len > 0) {
			uip_add_rcv_nxt(uip_len);
		}
		if (BUF->flags & TCP_FIN) {
			if (uip_flags & UIP_ACKDATA) {
				uip_connr->tcpstateflags = UIP_TIME_WAIT;
				uip_connr->timer = 0;
				uip_connr->len = 0;
			} else {
				uip_connr->tcpstateflags = UIP_CLOSING;
			}
			uip_add_rcv_nxt(1);
			uip_flags = UIP_CLOSE;
			UIP_APPCALL();
			goto tcp_send_ack;
		} else if (uip_flags & UIP_ACKDATA) {
			uip_connr->tcpstateflags = UIP_FIN_WAIT_2;
			uip_connr->len = 0;
			goto drop;
		}
		if (uip_len > 0) {
			goto tcp_send_ack;
		}
		goto drop;

	case UIP_FIN_WAIT_2:
		if (uip_len > 0) {
			uip_add_rcv_nxt(uip_len);
		}
		if (BUF->flags & TCP_FIN) {
			uip_connr->tcpstateflags = UIP_TIME_WAIT;
			uip_connr->timer = 0;
			uip_add_rcv_nxt(1);
			uip_flags = UIP_CLOSE;
			UIP_APPCALL();
			goto tcp_send_ack;
		}
		if (uip_len > 0) {
			goto tcp_send_ack;
		}
		goto drop;

	case UIP_TIME_WAIT:
		goto tcp_send_ack;

	case UIP_CLOSING:
		if (uip_flags & UIP_ACKDATA) {
			uip_connr->tcpstateflags = UIP_TIME_WAIT;
			uip_connr->timer = 0;
		}
	}
	goto drop;

	/* We jump here when we are ready to send the packet, and just want
	 to set the appropriate TCP sequence numbers in the TCP header. */
	tcp_send_ack:
	BUF->flags = TCP_ACK;
	tcp_send_nodata: uip_len = UIP_IPTCPH_LEN;
	tcp_send_noopts:
	BUF->tcpoffset = (UIP_TCPH_LEN / 4) << 4;
	tcp_send:
	/* We're done with the input processing. We are now ready to send a
	 reply. Our job is to fill in all the fields of the TCP and IP
	 headers before calculating the checksum and finally send the
	 packet. */
	BUF->ackno[0] = uip_connr->rcv_nxt[0];
	BUF->ackno[1] = uip_connr->rcv_nxt[1];
	BUF->ackno[2] = uip_connr->rcv_nxt[2];
	BUF->ackno[3] = uip_connr->rcv_nxt[3];

	BUF->seqno[0] = uip_connr->snd_nxt[0];
	BUF->seqno[1] = uip_connr->snd_nxt[1];
	BUF->seqno[2] = uip_connr->snd_nxt[2];
	BUF->seqno[3] = uip_connr->snd_nxt[3];

	BUF->proto = UIP_PROTO_TCP;

	BUF->srcport = uip_connr->lport;
	BUF->destport = uip_connr->rport;

	uip_ipaddr_copy(BUF->srcipaddr, uip_hostaddr);
	uip_ipaddr_copy(BUF->destipaddr, uip_connr->ripaddr);

	if (uip_connr->tcpstateflags & UIP_STOPPED) {
		/* If the connection has issued uip_stop(), we advertise a zero
		 window so that the remote host will stop sending data. */
		BUF->wnd[0] = BUF->wnd[1] = 0;
	} else {
		BUF->wnd[0] = ((UIP_RECEIVE_WINDOW) >> 8);
		BUF->wnd[1] = ((UIP_RECEIVE_WINDOW) & 0xff);
	}

	tcp_send_noconn:
	BUF->ttl = UIP_TTL;
#if UIP_CONF_IPV6
	/* For IPv6, the IP length field does not include the IPv6 IP header
	 length. */
	BUF->len[0] = ((uip_len - UIP_IPH_LEN) >> 8);
	BUF->len[1] = ((uip_len - UIP_IPH_LEN) & 0xff);
#else /* UIP_CONF_IPV6 */
	BUF->len[0] = (uip_len >> 8);
	BUF->len[1] = (uip_len & 0xff);
#endif /* UIP_CONF_IPV6 */

	BUF->urgp[0] = BUF->urgp[1] = 0;

	/* Calculate TCP checksum. */BUF->tcpchksum = 0;
	BUF->tcpchksum = ~(uip_tcpchksum());

#if UIP_UDP
	ip_send_nolen:
#endif

#if UIP_CONF_IPV6
	BUF->vtc = 0x60;
	BUF->tcflow = 0x00;
	BUF->flow = 0x00;
#else /* UIP_CONF_IPV6 */
	BUF->vhl = 0x45;
	BUF->tos = 0;
	BUF->ipoffset[0] = BUF->ipoffset[1] = 0;
	++ipid;
	BUF->ipid[0] = ipid >> 8;
	BUF->ipid[1] = ipid & 0xff;
	/* Calculate IP checksum. */BUF->ipchksum = 0;
	BUF->ipchksum = ~(uip_ipchksum());
	#if (UIP_USE_DEBUG == pdON)
	plog("UIP: uip ip_send_nolen: chkecum 0x%04x [%u]"CMD_TERMINATOR, uip_ipchksum(), __LINE__);
	#endif
#endif /* UIP_CONF_IPV6 */

	UIP_STAT(++uip_stat.tcp.sent);
	send:
	#if (UIP_USE_DEBUG == pdON)
	plog("UIP: Sending packet with length %d (%d) [%u]"CMD_TERMINATOR, uip_len,
			(BUF->len[0] << 8) | BUF->len[1], __LINE__);
	#endif

	UIP_STAT(++uip_stat.ip.sent);
	/* Return and let the caller do the actual transmission. */
	uip_flags = 0;
	return;
	drop: uip_len = 0;
	uip_flags = 0;
	return;
}
/*---------------------------------------------------------------------------*/
u16 htons(u16 val) {
	return HTONS(val);
}
/*---------------------------------------------------------------------------*/

void uip_send(const void *data, int len) {
	if(len > 0) {
		uip_slen = len;

		if(data != uip_sappdata) {
			memcpy(uip_sappdata, (data), uip_slen);
		}
		#if (UIP_USE_DEBUG == pdON)
		plog("UIP: uip send. uip_slen = %u bytes [%u]"CMD_TERMINATOR, uip_slen, __LINE__);
		#endif
	}
}

/*
void uip_send(const void *data, int len) {
	if (len > 0) {
		if (data != uip_sappdata) {
				memcpy(uip_sappdata, (data), len);
		}
		uip_slen = len;

		#if (UIP_USE_DEBUG == pdON)
		plog("UIP: uip send. uip_slen = %u bytes [%u]"CMD_TERMINATOR, uip_slen, __LINE__);
		#endif
	}
}
*/
/** @} */

