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diff --git a/Projects/Webserver/Lib/uip/uip.h b/Projects/Webserver/Lib/uip/uip.h
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+
+/**
+ * \addtogroup uip
+ * @{
+ */
+
+/**
+ * \file
+ * Header file for the uIP TCP/IP stack.
+ * \author  Adam Dunkels <adam@dunkels.com>
+ * \author  Julien Abeille <jabeille@cisco.com> (IPv6 related code)
+ * \author  Mathilde Durvy <mdurvy@cisco.com> (IPv6 related code)
+ *
+ * The uIP TCP/IP stack header file contains definitions for a number
+ * of C macros that are used by uIP programs as well as internal uIP
+ * structures, TCP/IP header structures and function declarations.
+ *
+ */
+
+/*
+ * 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.h,v 1.24 2009/04/06 13:18:50 nvt-se Exp $
+ *
+ */
+
+#ifndef __UIP_H__
+#define __UIP_H__
+
+#include "uipopt.h"
+
+/**
+ * Representation of an IP address.
+ *
+ */
+#if UIP_CONF_IPV6
+typedef union uip_ip6addr_t {
+  u8_t  u8[16];			/* Initialiser, must come first!!! */
+  u16_t u16[8];
+} uip_ip6addr_t;
+
+typedef uip_ip6addr_t uip_ipaddr_t;
+#else /* UIP_CONF_IPV6 */
+typedef union uip_ip4addr_t {
+  u8_t  u8[4];			/* Initialiser, must come first!!! */
+  u16_t u16[2];
+#if 0
+  u32_t u32;
+#endif
+} uip_ip4addr_t;
+typedef uip_ip4addr_t uip_ipaddr_t;
+#endif /* UIP_CONF_IPV6 */
+
+
+/*---------------------------------------------------------------------------*/
+
+/** \brief 16 bit 802.15.4 address */
+struct uip_802154_shortaddr {
+  u8_t addr[2];
+};
+/** \brief 64 bit 802.15.4 address */
+struct uip_802154_longaddr {
+  u8_t addr[8];
+};
+
+/** \brief 802.11 address */
+struct uip_80211_addr {
+  u8_t addr[6];
+};
+
+/** \brief 802.3 address */
+struct uip_eth_addr {
+  u8_t addr[6];
+};
+
+#if UIP_CONF_LL_802154
+/** \brief 802.15.4 address */
+typedef struct uip_802154_longaddr uip_lladdr_t;
+#define UIP_802154_SHORTADDR_LEN 2
+#define UIP_802154_LONGADDR_LEN  8
+#define UIP_LLADDR_LEN UIP_802154_LONGADDR_LEN
+#else /*UIP_CONF_LL_802154*/
+#if UIP_CONF_LL_80211
+/** \brief 802.11 address */
+typedef struct uip_80211_addr uip_lladdr_t;
+#define UIP_LLADDR_LEN 6
+#else /*UIP_CONF_LL_80211*/
+/** \brief Ethernet address */
+typedef struct uip_eth_addr uip_lladdr_t;
+#define UIP_LLADDR_LEN 6
+#endif /*UIP_CONF_LL_80211*/
+#endif /*UIP_CONF_LL_802154*/
+
+/*---------------------------------------------------------------------------*/
+/* First, the functions that should be called from the
+ * system. Initialization, the periodic timer, and incoming packets are
+ * handled by the following three functions.
+ */
+/**
+ * \defgroup uipconffunc uIP configuration functions
+ * @{
+ *
+ * The uIP configuration functions are used for setting run-time
+ * parameters in uIP such as IP addresses.
+ */
+
+/**
+ * Set the IP address of this host.
+ *
+ * The IP address is represented as a 4-byte array where the first
+ * octet of the IP address is put in the first member of the 4-byte
+ * array.
+ *
+ * Example:
+ \code
+
+ uip_ipaddr_t addr;
+
+ uip_ipaddr(&addr, 192,168,1,2);
+ uip_sethostaddr(&addr);
+
+ \endcode
+ * \param addr A pointer to an IP address of type uip_ipaddr_t;
+ *
+ * \sa uip_ipaddr()
+ *
+ * \hideinitializer
+ */
+#define uip_sethostaddr(addr) uip_ipaddr_copy(&uip_hostaddr, (addr))
+
+/**
+ * Get the IP address of this host.
+ *
+ * The IP address is represented as a 4-byte array where the first
+ * octet of the IP address is put in the first member of the 4-byte
+ * array.
+ *
+ * Example:
+ \code
+ uip_ipaddr_t hostaddr;
+
+ uip_gethostaddr(&hostaddr);
+ \endcode
+ * \param addr A pointer to a uip_ipaddr_t variable that will be
+ * filled in with the currently configured IP address.
+ *
+ * \hideinitializer
+ */
+#define uip_gethostaddr(addr) uip_ipaddr_copy((addr), &uip_hostaddr)
+
+/**
+ * Set the default router's IP address.
+ *
+ * \param addr A pointer to a uip_ipaddr_t variable containing the IP
+ * address of the default router.
+ *
+ * \sa uip_ipaddr()
+ *
+ * \hideinitializer
+ */
+#define uip_setdraddr(addr) uip_ipaddr_copy(&uip_draddr, (addr))
+
+/**
+ * Set the netmask.
+ *
+ * \param addr A pointer to a uip_ipaddr_t variable containing the IP
+ * address of the netmask.
+ *
+ * \sa uip_ipaddr()
+ *
+ * \hideinitializer
+ */
+#define uip_setnetmask(addr) uip_ipaddr_copy(&uip_netmask, (addr))
+
+
+/**
+ * Get the default router's IP address.
+ *
+ * \param addr A pointer to a uip_ipaddr_t variable that will be
+ * filled in with the IP address of the default router.
+ *
+ * \hideinitializer
+ */
+#define uip_getdraddr(addr) uip_ipaddr_copy((addr), &uip_draddr)
+
+/**
+ * Get the netmask.
+ *
+ * \param addr A pointer to a uip_ipaddr_t variable that will be
+ * filled in with the value of the netmask.
+ *
+ * \hideinitializer
+ */
+#define uip_getnetmask(addr) uip_ipaddr_copy((addr), &uip_netmask)
+
+/** @} */
+
+/**
+ * \defgroup uipinit uIP initialization functions
+ * @{
+ *
+ * The uIP initialization functions are used for booting uIP.
+ */
+
+/**
+ * uIP initialization function.
+ *
+ * This function should be called at boot up to initialize the uIP
+ * TCP/IP stack.
+ */
+void uip_init(void);
+
+/**
+ * uIP initialization function.
+ *
+ * This function may be used at boot time to set the initial ip_id.
+ */
+void uip_setipid(u16_t id);
+
+/** @} */
+
+/**
+ * \defgroup uipdevfunc uIP device driver functions
+ * @{
+ *
+ * These functions are used by a network device driver for interacting
+ * with uIP.
+ */
+
+/**
+ * Process an incoming packet.
+ *
+ * This function should be called when the device driver has received
+ * a packet from the network. The packet from the device driver must
+ * be present in the uip_buf buffer, and the length of the packet
+ * should be placed in the uip_len variable.
+ *
+ * When the function returns, there may be an outbound packet placed
+ * in the uip_buf packet buffer. If so, the uip_len variable is set to
+ * the length of the packet. If no packet is to be sent out, the
+ * uip_len variable is set to 0.
+ *
+ * The usual way of calling the function is presented by the source
+ * code below.
+ \code
+ uip_len = devicedriver_poll();
+ if(uip_len > 0) {
+ uip_input();
+ if(uip_len > 0) {
+ devicedriver_send();
+ }
+ }
+ \endcode
+ *
+ * \note If you are writing a uIP device driver that needs ARP
+ * (Address Resolution Protocol), e.g., when running uIP over
+ * Ethernet, you will need to call the uIP ARP code before calling
+ * this function:
+ \code
+ #define BUF ((struct uip_eth_hdr *)&uip_buf[0])
+ uip_len = ethernet_devicedrver_poll();
+ if(uip_len > 0) {
+ if(BUF->type == HTONS(UIP_ETHTYPE_IP)) {
+ uip_arp_ipin();
+ uip_input();
+ if(uip_len > 0) {
+ uip_arp_out();
+ ethernet_devicedriver_send();
+ }
+ } else if(BUF->type == HTONS(UIP_ETHTYPE_ARP)) {
+ uip_arp_arpin();
+ if(uip_len > 0) {
+ ethernet_devicedriver_send();
+ }
+ }
+ \endcode
+ *
+ * \hideinitializer
+ */
+#define uip_input()        uip_process(UIP_DATA)
+
+
+/**
+ * Periodic processing for a connection identified by its number.
+ *
+ * This function does the necessary periodic processing (timers,
+ * polling) for a uIP TCP connection, and should be called when the
+ * periodic uIP timer goes off. It should be called for every
+ * connection, regardless of whether they are open of closed.
+ *
+ * When the function returns, it may have an outbound packet waiting
+ * for service in the uIP packet buffer, and if so the uip_len
+ * variable is set to a value larger than zero. The device driver
+ * should be called to send out the packet.
+ *
+ * The usual way of calling the function is through a for() loop like
+ * this:
+ \code
+ for(i = 0; i < UIP_CONNS; ++i) {
+ uip_periodic(i);
+ if(uip_len > 0) {
+ devicedriver_send();
+ }
+ }
+ \endcode
+ *
+ * \note If you are writing a uIP device driver that needs ARP
+ * (Address Resolution Protocol), e.g., when running uIP over
+ * Ethernet, you will need to call the uip_arp_out() function before
+ * calling the device driver:
+ \code
+ for(i = 0; i < UIP_CONNS; ++i) {
+ uip_periodic(i);
+ if(uip_len > 0) {
+ uip_arp_out();
+ ethernet_devicedriver_send();
+ }
+ }
+ \endcode
+ *
+ * \param conn The number of the connection which is to be periodically polled.
+ *
+ * \hideinitializer
+ */
+#if UIP_TCP
+#define uip_periodic(conn) do { uip_conn = &uip_conns[conn];    \
+    uip_process(UIP_TIMER); } while (0)
+
+/**
+ *
+ *
+ */
+#define uip_conn_active(conn) (uip_conns[conn].tcpstateflags != UIP_CLOSED)
+
+/**
+ * Perform periodic processing for a connection identified by a pointer
+ * to its structure.
+ *
+ * Same as uip_periodic() but takes a pointer to the actual uip_conn
+ * struct instead of an integer as its argument. This function can be
+ * used to force periodic processing of a specific connection.
+ *
+ * \param conn A pointer to the uip_conn struct for the connection to
+ * be processed.
+ *
+ * \hideinitializer
+ */
+#define uip_periodic_conn(conn) do { uip_conn = conn;   \
+    uip_process(UIP_TIMER); } while (0)
+
+/**
+ * Request that a particular connection should be polled.
+ *
+ * Similar to uip_periodic_conn() but does not perform any timer
+ * processing. The application is polled for new data.
+ *
+ * \param conn A pointer to the uip_conn struct for the connection to
+ * be processed.
+ *
+ * \hideinitializer
+ */
+#define uip_poll_conn(conn) do { uip_conn = conn;       \
+    uip_process(UIP_POLL_REQUEST); } while (0)
+
+#endif /* UIP_TCP */
+
+#if UIP_UDP
+/**
+ * Periodic processing for a UDP connection identified by its number.
+ *
+ * This function is essentially the same as uip_periodic(), but for
+ * UDP connections. It is called in a similar fashion as the
+ * uip_periodic() function:
+ \code
+ for(i = 0; i < UIP_UDP_CONNS; i++) {
+ uip_udp_periodic(i);
+ if(uip_len > 0) {
+ devicedriver_send();
+ }
+ }
+ \endcode
+ *
+ * \note As for the uip_periodic() function, special care has to be
+ * taken when using uIP together with ARP and Ethernet:
+ \code
+ for(i = 0; i < UIP_UDP_CONNS; i++) {
+ uip_udp_periodic(i);
+ if(uip_len > 0) {
+ uip_arp_out();
+ ethernet_devicedriver_send();
+ }
+ }
+ \endcode
+ *
+ * \param conn The number of the UDP connection to be processed.
+ *
+ * \hideinitializer
+ */
+#define uip_udp_periodic(conn) do { uip_udp_conn = &uip_udp_conns[conn]; \
+    uip_process(UIP_UDP_TIMER); } while(0)
+
+/**
+ * Periodic processing for a UDP connection identified by a pointer to
+ * its structure.
+ *
+ * Same as uip_udp_periodic() but takes a pointer to the actual
+ * uip_conn struct instead of an integer as its argument. This
+ * function can be used to force periodic processing of a specific
+ * connection.
+ *
+ * \param conn A pointer to the uip_udp_conn struct for the connection
+ * to be processed.
+ *
+ * \hideinitializer
+ */
+#define uip_udp_periodic_conn(conn) do { uip_udp_conn = conn;   \
+    uip_process(UIP_UDP_TIMER); } while(0)
+#endif /* UIP_UDP */
+
+/** \brief Abandon the reassembly of the current packet */
+void uip_reass_over(void);
+
+/**
+ * The uIP packet buffer.
+ *
+ * The uip_buf array is used to hold incoming and outgoing
+ * packets. The device driver should place incoming data into this
+ * buffer. When sending data, the device driver should read the link
+ * level headers and the TCP/IP headers from this buffer. The size of
+ * the link level headers is configured by the UIP_LLH_LEN define.
+ *
+ * \note The application data need not be placed in this buffer, so
+ * the device driver must read it from the place pointed to by the
+ * uip_appdata pointer as illustrated by the following example:
+ \code
+ void
+ devicedriver_send(void)
+ {
+ hwsend(&uip_buf[0], UIP_LLH_LEN);
+ if(uip_len <= UIP_LLH_LEN + UIP_TCPIP_HLEN) {
+ hwsend(&uip_buf[UIP_LLH_LEN], uip_len - UIP_LLH_LEN);
+ } else {
+ hwsend(&uip_buf[UIP_LLH_LEN], UIP_TCPIP_HLEN);
+ hwsend(uip_appdata, uip_len - UIP_TCPIP_HLEN - UIP_LLH_LEN);
+ }
+ }
+ \endcode
+*/
+extern u8_t uip_buf[UIP_BUFSIZE+2];
+
+
+
+/** @} */
+
+/*---------------------------------------------------------------------------*/
+/* Functions that are used by the uIP application program. Opening and
+ * closing connections, sending and receiving data, etc. is all
+ * handled by the functions below.
+ */
+/**
+ * \defgroup uipappfunc uIP application functions
+ * @{
+ *
+ * Functions used by an application running of top of uIP.
+ */
+
+/**
+ * Start listening to the specified port.
+ *
+ * \note Since this function expects the port number in network byte
+ * order, a conversion using HTONS() or htons() is necessary.
+ *
+ \code
+ uip_listen(HTONS(80));
+ \endcode
+ *
+ * \param port A 16-bit port number in network byte order.
+ */
+void uip_listen(u16_t port);
+
+/**
+ * Stop listening to the specified port.
+ *
+ * \note Since this function expects the port number in network byte
+ * order, a conversion using HTONS() or htons() is necessary.
+ *
+ \code
+ uip_unlisten(HTONS(80));
+ \endcode
+ *
+ * \param port A 16-bit port number in network byte order.
+ */
+void uip_unlisten(u16_t port);
+
+/**
+ * Connect to a remote host using TCP.
+ *
+ * This function is used to start a new connection to the specified
+ * port on the specified host. It allocates a new connection identifier,
+ * sets the connection to the SYN_SENT state and sets the
+ * retransmission timer to 0. This will cause a TCP SYN segment to be
+ * sent out the next time this connection is periodically processed,
+ * which usually is done within 0.5 seconds after the call to
+ * uip_connect().
+ *
+ * \note This function is available only if support for active open
+ * has been configured by defining UIP_ACTIVE_OPEN to 1 in uipopt.h.
+ *
+ * \note Since this function requires the port number to be in network
+ * byte order, a conversion using HTONS() or htons() is necessary.
+ *
+ \code
+ uip_ipaddr_t ipaddr;
+
+ uip_ipaddr(&ipaddr, 192,168,1,2);
+ uip_connect(&ipaddr, HTONS(80));
+ \endcode
+ *
+ * \param ripaddr The IP address of the remote host.
+ *
+ * \param port A 16-bit port number in network byte order.
+ *
+ * \return A pointer to the uIP connection identifier for the new connection,
+ * or NULL if no connection could be allocated.
+ *
+ */
+struct uip_conn *uip_connect(uip_ipaddr_t *ripaddr, u16_t port);
+
+
+
+/**
+ * \internal
+ *
+ * Check if a connection has outstanding (i.e., unacknowledged) data.
+ *
+ * \param conn A pointer to the uip_conn structure for the connection.
+ *
+ * \hideinitializer
+ */
+#define uip_outstanding(conn) ((conn)->len)
+
+/**
+ * Send data on the current connection.
+ *
+ * This function is used to send out a single segment of TCP
+ * data. Only applications that have been invoked by uIP for event
+ * processing can send data.
+ *
+ * The amount of data that actually is sent out after a call to this
+ * function is determined by the maximum amount of data TCP allows. uIP
+ * will automatically crop the data so that only the appropriate
+ * amount of data is sent. The function uip_mss() can be used to query
+ * uIP for the amount of data that actually will be sent.
+ *
+ * \note This function does not guarantee that the sent data will
+ * arrive at the destination. If the data is lost in the network, the
+ * application will be invoked with the uip_rexmit() event being
+ * set. The application will then have to resend the data using this
+ * function.
+ *
+ * \param data A pointer to the data which is to be sent.
+ *
+ * \param len The maximum amount of data bytes to be sent.
+ *
+ * \hideinitializer
+ */
+void uip_send(const void *data, int len);
+
+/**
+ * The length of any incoming data that is currently available (if available)
+ * in the uip_appdata buffer.
+ *
+ * The test function uip_data() must first be used to check if there
+ * is any data available at all.
+ *
+ * \hideinitializer
+ */
+/*void uip_datalen(void);*/
+#define uip_datalen()       uip_len
+
+/**
+ * The length of any out-of-band data (urgent data) that has arrived
+ * on the connection.
+ *
+ * \note The configuration parameter UIP_URGDATA must be set for this
+ * function to be enabled.
+ *
+ * \hideinitializer
+ */
+#define uip_urgdatalen()    uip_urglen
+
+/**
+ * Close the current connection.
+ *
+ * This function will close the current connection in a nice way.
+ *
+ * \hideinitializer
+ */
+#define uip_close()         (uip_flags = UIP_CLOSE)
+
+/**
+ * Abort the current connection.
+ *
+ * This function will abort (reset) the current connection, and is
+ * usually used when an error has occurred that prevents using the
+ * uip_close() function.
+ *
+ * \hideinitializer
+ */
+#define uip_abort()         (uip_flags = UIP_ABORT)
+
+/**
+ * Tell the sending host to stop sending data.
+ *
+ * This function will close our receiver's window so that we stop
+ * receiving data for the current connection.
+ *
+ * \hideinitializer
+ */
+#define uip_stop()          (uip_conn->tcpstateflags |= UIP_STOPPED)
+
+/**
+ * Find out if the current connection has been previously stopped with
+ * uip_stop().
+ *
+ * \hideinitializer
+ */
+#define uip_stopped(conn)   ((conn)->tcpstateflags & UIP_STOPPED)
+
+/**
+ * Restart the current connection, if is has previously been stopped
+ * with uip_stop().
+ *
+ * This function will open the receiver's window again so that we
+ * start receiving data for the current connection.
+ *
+ * \hideinitializer
+ */
+#define uip_restart()         do { uip_flags |= UIP_NEWDATA;    \
+    uip_conn->tcpstateflags &= ~UIP_STOPPED;                    \
+  } while(0)
+
+
+/* uIP tests that can be made to determine in what state the current
+   connection is, and what the application function should do. */
+
+/**
+ * Is the current connection a UDP connection?
+ *
+ * This function checks whether the current connection is a UDP connection.
+ *
+ * \hideinitializer
+ *
+ */
+#define uip_udpconnection() (uip_conn == NULL)
+
+/**
+ * Is new incoming data available?
+ *
+ * Will reduce to non-zero if there is new data for the application
+ * present at the uip_appdata pointer. The size of the data is
+ * available through the uip_len variable.
+ *
+ * \hideinitializer
+ */
+#define uip_newdata()   (uip_flags & UIP_NEWDATA)
+
+/**
+ * Has previously sent data been acknowledged?
+ *
+ * Will reduce to non-zero if the previously sent data has been
+ * acknowledged by the remote host. This means that the application
+ * can send new data.
+ *
+ * \hideinitializer
+ */
+#define uip_acked()   (uip_flags & UIP_ACKDATA)
+
+/**
+ * Has the connection just been connected?
+ *
+ * Reduces to non-zero if the current connection has been connected to
+ * a remote host. This will happen both if the connection has been
+ * actively opened (with uip_connect()) or passively opened (with
+ * uip_listen()).
+ *
+ * \hideinitializer
+ */
+#define uip_connected() (uip_flags & UIP_CONNECTED)
+
+/**
+ * Has the connection been closed by the other end?
+ *
+ * Is non-zero if the connection has been closed by the remote
+ * host. The application may then do the necessary clean-ups.
+ *
+ * \hideinitializer
+ */
+#define uip_closed()    (uip_flags & UIP_CLOSE)
+
+/**
+ * Has the connection been aborted by the other end?
+ *
+ * Non-zero if the current connection has been aborted (reset) by the
+ * remote host.
+ *
+ * \hideinitializer
+ */
+#define uip_aborted()    (uip_flags & UIP_ABORT)
+
+/**
+ * Has the connection timed out?
+ *
+ * Non-zero if the current connection has been aborted due to too many
+ * retransmissions.
+ *
+ * \hideinitializer
+ */
+#define uip_timedout()    (uip_flags & UIP_TIMEDOUT)
+
+/**
+ * Do we need to retransmit previously data?
+ *
+ * Reduces to non-zero if the previously sent data has been lost in
+ * the network, and the application should retransmit it. The
+ * application should send the exact same data as it did the last
+ * time, using the uip_send() function.
+ *
+ * \hideinitializer
+ */
+#define uip_rexmit()     (uip_flags & UIP_REXMIT)
+
+/**
+ * Is the connection being polled by uIP?
+ *
+ * Is non-zero if the reason the application is invoked is that the
+ * current connection has been idle for a while and should be
+ * polled.
+ *
+ * The polling event can be used for sending data without having to
+ * wait for the remote host to send data.
+ *
+ * \hideinitializer
+ */
+#define uip_poll()       (uip_flags & UIP_POLL)
+
+/**
+ * Get the initial maximum segment size (MSS) of the current
+ * connection.
+ *
+ * \hideinitializer
+ */
+#define uip_initialmss()             (uip_conn->initialmss)
+
+/**
+ * Get the current maximum segment size that can be sent on the current
+ * connection.
+ *
+ * The current maximum segment size that can be sent on the
+ * connection is computed from the receiver's window and the MSS of
+ * the connection (which also is available by calling
+ * uip_initialmss()).
+ *
+ * \hideinitializer
+ */
+#define uip_mss()             (uip_conn->mss)
+
+/**
+ * Set up a new UDP connection.
+ *
+ * This function sets up a new UDP connection. The function will
+ * automatically allocate an unused local port for the new
+ * connection. However, another port can be chosen by using the
+ * uip_udp_bind() call, after the uip_udp_new() function has been
+ * called.
+ *
+ * Example:
+ \code
+ uip_ipaddr_t addr;
+ struct uip_udp_conn *c;
+
+ uip_ipaddr(&addr, 192,168,2,1);
+ c = uip_udp_new(&addr, HTONS(12345));
+ if(c != NULL) {
+ uip_udp_bind(c, HTONS(12344));
+ }
+ \endcode
+ * \param ripaddr The IP address of the remote host.
+ *
+ * \param rport The remote port number in network byte order.
+ *
+ * \return The uip_udp_conn structure for the new connection or NULL
+ * if no connection could be allocated.
+ */
+struct uip_udp_conn *uip_udp_new(const uip_ipaddr_t *ripaddr, u16_t rport);
+
+/**
+ * Removed a UDP connection.
+ *
+ * \param conn A pointer to the uip_udp_conn structure for the connection.
+ *
+ * \hideinitializer
+ */
+#define uip_udp_remove(conn) (conn)->lport = 0
+
+/**
+ * Bind a UDP connection to a local port.
+ *
+ * \param conn A pointer to the uip_udp_conn structure for the
+ * connection.
+ *
+ * \param port The local port number, in network byte order.
+ *
+ * \hideinitializer
+ */
+#define uip_udp_bind(conn, port) (conn)->lport = port
+
+/**
+ * Send a UDP datagram of length len on the current connection.
+ *
+ * This function can only be called in response to a UDP event (poll
+ * or newdata). The data must be present in the uip_buf buffer, at the
+ * place pointed to by the uip_appdata pointer.
+ *
+ * \param len The length of the data in the uip_buf buffer.
+ *
+ * \hideinitializer
+ */
+#define uip_udp_send(len) uip_send((char *)uip_appdata, len)
+
+/** @} */
+
+/* uIP convenience and converting functions. */
+
+/**
+ * \defgroup uipconvfunc uIP conversion functions
+ * @{
+ *
+ * These functions can be used for converting between different data
+ * formats used by uIP.
+ */
+
+/**
+ * Convert an IP address to four bytes separated by commas.
+ *
+ * Example:
+ \code
+ uip_ipaddr_t ipaddr;
+ printf("ipaddr=%d.%d.%d.%d\n", uip_ipaddr_to_quad(&ipaddr));
+ \endcode
+ *
+ * \param a A pointer to a uip_ipaddr_t.
+ * \hideinitializer
+ */
+#define uip_ipaddr_to_quad(a) (a)->u8[0],(a)->u8[1],(a)->u8[2],(a)->u8[3]
+
+/**
+ * Construct an IP address from four bytes.
+ *
+ * This function constructs an IP address of the type that uIP handles
+ * internally from four bytes. The function is handy for specifying IP
+ * addresses to use with e.g. the uip_connect() function.
+ *
+ * Example:
+ \code
+ uip_ipaddr_t ipaddr;
+ struct uip_conn *c;
+
+ uip_ipaddr(&ipaddr, 192,168,1,2);
+ c = uip_connect(&ipaddr, HTONS(80));
+ \endcode
+ *
+ * \param addr A pointer to a uip_ipaddr_t variable that will be
+ * filled in with the IP address.
+ *
+ * \param addr0 The first octet of the IP address.
+ * \param addr1 The second octet of the IP address.
+ * \param addr2 The third octet of the IP address.
+ * \param addr3 The forth octet of the IP address.
+ *
+ * \hideinitializer
+ */
+#define uip_ipaddr(addr, addr0,addr1,addr2,addr3) do {  \
+    (addr)->u8[0] = addr0;                              \
+    (addr)->u8[1] = addr1;                              \
+    (addr)->u8[2] = addr2;                              \
+    (addr)->u8[3] = addr3;                              \
+  } while(0)
+
+/**
+ * Construct an IPv6 address from eight 16-bit words.
+ *
+ * This function constructs an IPv6 address.
+ *
+ * \hideinitializer
+ */
+#define uip_ip6addr(addr, addr0,addr1,addr2,addr3,addr4,addr5,addr6,addr7) do { \
+    (addr)->u16[0] = HTONS(addr0);                                      \
+    (addr)->u16[1] = HTONS(addr1);                                      \
+    (addr)->u16[2] = HTONS(addr2);                                      \
+    (addr)->u16[3] = HTONS(addr3);                                      \
+    (addr)->u16[4] = HTONS(addr4);                                      \
+    (addr)->u16[5] = HTONS(addr5);                                      \
+    (addr)->u16[6] = HTONS(addr6);                                      \
+    (addr)->u16[7] = HTONS(addr7);                                      \
+  } while(0)
+
+/**
+ * Construct an IPv6 address from sixteen 8-bit words.
+ *
+ * This function constructs an IPv6 address.
+ *
+ * \hideinitializer
+ */
+#define uip_ip6addr_u8(addr, addr0,addr1,addr2,addr3,addr4,addr5,addr6,addr7,addr8,addr9,addr10,addr11,addr12,addr13,addr14,addr15) do { \
+    (addr)->u8[0] = addr0;                                       \
+    (addr)->u8[1] = addr1;                                       \
+    (addr)->u8[2] = addr2;                                       \
+    (addr)->u8[3] = addr3;                                       \
+    (addr)->u8[4] = addr4;                                       \
+    (addr)->u8[5] = addr5;                                       \
+    (addr)->u8[6] = addr6;                                       \
+    (addr)->u8[7] = addr7;                                       \
+    (addr)->u8[8] = addr8;                                       \
+    (addr)->u8[9] = addr9;                                       \
+    (addr)->u8[10] = addr10;                                     \
+    (addr)->u8[11] = addr11;                                     \
+    (addr)->u8[12] = addr12;                                     \
+    (addr)->u8[13] = addr13;                                     \
+    (addr)->u8[14] = addr14;                                     \
+    (addr)->u8[15] = addr15;                                     \
+  } while(0)
+
+
+/**
+ * Copy an IP address to another IP address.
+ *
+ * Copies an IP address from one place to another.
+ *
+ * Example:
+ \code
+ uip_ipaddr_t ipaddr1, ipaddr2;
+
+ uip_ipaddr(&ipaddr1, 192,16,1,2);
+ uip_ipaddr_copy(&ipaddr2, &ipaddr1);
+ \endcode
+ *
+ * \param dest The destination for the copy.
+ * \param src The source from where to copy.
+ *
+ * \hideinitializer
+ */
+#ifndef uip_ipaddr_copy
+#define uip_ipaddr_copy(dest, src) (*(dest) = *(src))
+#endif
+
+/**
+ * Compare two IP addresses
+ *
+ * Compares two IP addresses.
+ *
+ * Example:
+ \code
+ uip_ipaddr_t ipaddr1, ipaddr2;
+
+ uip_ipaddr(&ipaddr1, 192,16,1,2);
+ if(uip_ipaddr_cmp(&ipaddr2, &ipaddr1)) {
+ printf("They are the same");
+ }
+ \endcode
+ *
+ * \param addr1 The first IP address.
+ * \param addr2 The second IP address.
+ *
+ * \hideinitializer
+ */
+#if !UIP_CONF_IPV6
+#define uip_ipaddr_cmp(addr1, addr2) ((addr1)->u16[0] == (addr2)->u16[0] && \
+				      (addr1)->u16[1] == (addr2)->u16[1])
+#else /* !UIP_CONF_IPV6 */
+#define uip_ipaddr_cmp(addr1, addr2) (memcmp(addr1, addr2, sizeof(uip_ip6addr_t)) == 0)
+#endif /* !UIP_CONF_IPV6 */
+
+/**
+ * Compare two IP addresses with netmasks
+ *
+ * Compares two IP addresses with netmasks. The masks are used to mask
+ * out the bits that are to be compared.
+ *
+ * Example:
+ \code
+ uip_ipaddr_t ipaddr1, ipaddr2, mask;
+
+ uip_ipaddr(&mask, 255,255,255,0);
+ uip_ipaddr(&ipaddr1, 192,16,1,2);
+ uip_ipaddr(&ipaddr2, 192,16,1,3);
+ if(uip_ipaddr_maskcmp(&ipaddr1, &ipaddr2, &mask)) {
+ printf("They are the same");
+ }
+ \endcode
+ *
+ * \param addr1 The first IP address.
+ * \param addr2 The second IP address.
+ * \param mask The netmask.
+ *
+ * \hideinitializer
+ */
+#if !UIP_CONF_IPV6
+#define uip_ipaddr_maskcmp(addr1, addr2, mask)          \
+  (((((u16_t *)addr1)[0] & ((u16_t *)mask)[0]) ==       \
+    (((u16_t *)addr2)[0] & ((u16_t *)mask)[0])) &&      \
+   ((((u16_t *)addr1)[1] & ((u16_t *)mask)[1]) ==       \
+    (((u16_t *)addr2)[1] & ((u16_t *)mask)[1])))
+#else
+#define uip_ipaddr_prefixcmp(addr1, addr2, length) (memcmp(addr1, addr2, length>>3) == 0)
+#endif
+
+
+/**
+ * Check if an address is a broadcast address for a network.
+ *
+ * Checks if an address is the broadcast address for a network. The
+ * network is defined by an IP address that is on the network and the
+ * network's netmask.
+ *
+ * \param addr The IP address.
+ * \param netaddr The network's IP address.
+ * \param netmask The network's netmask.
+ *
+ * \hideinitializer
+ */
+/*#define uip_ipaddr_isbroadcast(addr, netaddr, netmask)
+  ((uip_ipaddr_t *)(addr)).u16 & ((uip_ipaddr_t *)(addr)).u16*/
+
+
+
+/**
+ * Mask out the network part of an IP address.
+ *
+ * Masks out the network part of an IP address, given the address and
+ * the netmask.
+ *
+ * Example:
+ \code
+ uip_ipaddr_t ipaddr1, ipaddr2, netmask;
+
+ uip_ipaddr(&ipaddr1, 192,16,1,2);
+ uip_ipaddr(&netmask, 255,255,255,0);
+ uip_ipaddr_mask(&ipaddr2, &ipaddr1, &netmask);
+ \endcode
+ *
+ * In the example above, the variable "ipaddr2" will contain the IP
+ * address 192.168.1.0.
+ *
+ * \param dest Where the result is to be placed.
+ * \param src The IP address.
+ * \param mask The netmask.
+ *
+ * \hideinitializer
+ */
+#define uip_ipaddr_mask(dest, src, mask) do {                           \
+    ((u16_t *)dest)[0] = ((u16_t *)src)[0] & ((u16_t *)mask)[0];        \
+    ((u16_t *)dest)[1] = ((u16_t *)src)[1] & ((u16_t *)mask)[1];        \
+  } while(0)
+
+/**
+ * Pick the first octet of an IP address.
+ *
+ * Picks out the first octet of an IP address.
+ *
+ * Example:
+ \code
+ uip_ipaddr_t ipaddr;
+ u8_t octet;
+
+ uip_ipaddr(&ipaddr, 1,2,3,4);
+ octet = uip_ipaddr1(&ipaddr);
+ \endcode
+ *
+ * In the example above, the variable "octet" will contain the value 1.
+ *
+ * \hideinitializer
+ */
+#define uip_ipaddr1(addr) ((addr)->u8[0])
+
+/**
+ * Pick the second octet of an IP address.
+ *
+ * Picks out the second octet of an IP address.
+ *
+ * Example:
+ \code
+ uip_ipaddr_t ipaddr;
+ u8_t octet;
+
+ uip_ipaddr(&ipaddr, 1,2,3,4);
+ octet = uip_ipaddr2(&ipaddr);
+ \endcode
+ *
+ * In the example above, the variable "octet" will contain the value 2.
+ *
+ * \hideinitializer
+ */
+#define uip_ipaddr2(addr) ((addr)->u8[1])
+
+/**
+ * Pick the third octet of an IP address.
+ *
+ * Picks out the third octet of an IP address.
+ *
+ * Example:
+ \code
+ uip_ipaddr_t ipaddr;
+ u8_t octet;
+
+ uip_ipaddr(&ipaddr, 1,2,3,4);
+ octet = uip_ipaddr3(&ipaddr);
+ \endcode
+ *
+ * In the example above, the variable "octet" will contain the value 3.
+ *
+ * \hideinitializer
+ */
+#define uip_ipaddr3(addr) ((addr)->u8[2])
+
+/**
+ * Pick the fourth octet of an IP address.
+ *
+ * Picks out the fourth octet of an IP address.
+ *
+ * Example:
+ \code
+ uip_ipaddr_t ipaddr;
+ u8_t octet;
+
+ uip_ipaddr(&ipaddr, 1,2,3,4);
+ octet = uip_ipaddr4(&ipaddr);
+ \endcode
+ *
+ * In the example above, the variable "octet" will contain the value 4.
+ *
+ * \hideinitializer
+ */
+#define uip_ipaddr4(addr) ((addr)->u8[3])
+
+/**
+ * Convert 16-bit quantity from host byte order to network byte order.
+ *
+ * This macro is primarily used for converting constants from host
+ * byte order to network byte order. For converting variables to
+ * network byte order, use the htons() function instead.
+ *
+ * \hideinitializer
+ */
+#ifndef HTONS
+#   if UIP_BYTE_ORDER == UIP_BIG_ENDIAN
+#      define HTONS(n) (n)
+#      define HTONL(n) (n)
+#   else /* UIP_BYTE_ORDER == UIP_BIG_ENDIAN */
+#      define HTONS(n) (u16_t)((((u16_t) (n)) << 8) | (((u16_t) (n)) >> 8))
+#      define HTONL(n) (((u32_t)HTONS(n) << 16) | HTONS((u32_t)(n) >> 16))
+#   endif /* UIP_BYTE_ORDER == UIP_BIG_ENDIAN */
+#else
+#error "HTONS already defined!"
+#endif /* HTONS */
+
+/**
+ * Convert 16-bit quantity from host byte order to network byte order.
+ *
+ * This function is primarily used for converting variables from host
+ * byte order to network byte order. For converting constants to
+ * network byte order, use the HTONS() macro instead.
+ */
+#ifndef htons
+u16_t htons(u16_t val);
+#endif /* htons */
+#ifndef ntohs
+#define ntohs htons
+#endif
+
+#ifndef htonl
+u32_t htonl(u32_t val);
+#endif /* htonl */
+#ifndef ntohl
+#define ntohl htonl
+#endif
+
+/** @} */
+
+/**
+ * Pointer to the application data in the packet buffer.
+ *
+ * This pointer points to the application data when the application is
+ * called. If the application wishes to send data, the application may
+ * use this space to write the data into before calling uip_send().
+ */
+extern void *uip_appdata;
+
+#if UIP_URGDATA > 0
+/* u8_t *uip_urgdata:
+ *
+ * This pointer points to any urgent data that has been received. Only
+ * present if compiled with support for urgent data (UIP_URGDATA).
+ */
+extern void *uip_urgdata;
+#endif /* UIP_URGDATA > 0 */
+
+
+/**
+ * \defgroup uipdrivervars Variables used in uIP device drivers
+ * @{
+ *
+ * uIP has a few global variables that are used in device drivers for
+ * uIP.
+ */
+
+/**
+ * The length of the packet in the uip_buf buffer.
+ *
+ * The global variable uip_len holds the length of the packet in the
+ * uip_buf buffer.
+ *
+ * When the network device driver calls the uIP input function,
+ * uip_len should be set to the length of the packet in the uip_buf
+ * buffer.
+ *
+ * When sending packets, the device driver should use the contents of
+ * the uip_len variable to determine the length of the outgoing
+ * packet.
+ *
+ */
+extern u16_t uip_len;
+
+/**
+ * The length of the extension headers
+ */
+extern u8_t uip_ext_len;
+/** @} */
+
+#if UIP_URGDATA > 0
+extern u16_t uip_urglen, uip_surglen;
+#endif /* UIP_URGDATA > 0 */
+
+
+/**
+ * Representation of a uIP TCP connection.
+ *
+ * The uip_conn structure is used for identifying a connection. All
+ * but one field in the structure are to be considered read-only by an
+ * application. The only exception is the appstate field whose purpose
+ * is to let the application store application-specific state (e.g.,
+ * file pointers) for the connection. The type of this field is
+ * configured in the "uipopt.h" header file.
+ */
+struct uip_conn {
+  uip_ipaddr_t ripaddr;   /**< The IP address of the remote host. */
+
+  u16_t lport;        /**< The local TCP port, in network byte order. */
+  u16_t rport;        /**< The local remote TCP port, in network byte
+			 order. */
+
+  u8_t rcv_nxt[4];    /**< The sequence number that we expect to
+			 receive next. */
+  u8_t snd_nxt[4];    /**< The sequence number that was last sent by
+                         us. */
+  u16_t len;          /**< Length of the data that was previously sent. */
+  u16_t mss;          /**< Current maximum segment size for the
+			 connection. */
+  u16_t initialmss;   /**< Initial maximum segment size for the
+			 connection. */
+  u8_t sa;            /**< Retransmission time-out calculation state
+			 variable. */
+  u8_t sv;            /**< Retransmission time-out calculation state
+			 variable. */
+  u8_t rto;           /**< Retransmission time-out. */
+  u8_t tcpstateflags; /**< TCP state and flags. */
+  u8_t timer;         /**< The retransmission timer. */
+  u8_t nrtx;          /**< The number of retransmissions for the last
+			 segment sent. */
+
+  /** The application state. */
+  uip_tcp_appstate_t appstate;
+};
+
+
+/**
+ * Pointer to the current TCP connection.
+ *
+ * The uip_conn pointer can be used to access the current TCP
+ * connection.
+ */
+
+extern struct uip_conn *uip_conn;
+#if UIP_TCP
+/* The array containing all uIP connections. */
+extern struct uip_conn uip_conns[UIP_CONNS];
+#endif
+
+/**
+ * \addtogroup uiparch
+ * @{
+ */
+
+/**
+ * 4-byte array used for the 32-bit sequence number calculations.
+ */
+extern u8_t uip_acc32[4];
+/** @} */
+
+/**
+ * Representation of a uIP UDP connection.
+ */
+struct uip_udp_conn {
+  uip_ipaddr_t ripaddr;   /**< The IP address of the remote peer. */
+  u16_t lport;        /**< The local port number in network byte order. */
+  u16_t rport;        /**< The remote port number in network byte order. */
+  u8_t  ttl;          /**< Default time-to-live. */
+
+  /** The application state. */
+  uip_udp_appstate_t appstate;
+};
+
+/**
+ * The current UDP connection.
+ */
+extern struct uip_udp_conn *uip_udp_conn;
+extern struct uip_udp_conn uip_udp_conns[UIP_UDP_CONNS];
+
+struct uip_router {
+  int (*activate)(void);
+  int (*deactivate)(void);
+  uip_ipaddr_t *(*lookup)(uip_ipaddr_t *destipaddr, uip_ipaddr_t *nexthop);
+};
+
+#if UIP_CONF_ROUTER
+extern const struct uip_router *uip_router;
+
+/**
+ * uIP routing driver registration function.
+ */
+void uip_router_register(const struct uip_router *router);
+#endif /*UIP_CONF_ROUTER*/
+
+#if UIP_CONF_ICMP6
+struct uip_icmp6_conn {
+  uip_icmp6_appstate_t appstate;
+};
+extern struct uip_icmp6_conn uip_icmp6_conns;
+#endif /*UIP_CONF_ICMP6*/
+
+/**
+ * The uIP TCP/IP statistics.
+ *
+ * This is the variable in which the uIP TCP/IP statistics are gathered.
+ */
+#if UIP_STATISTICS == 1
+extern struct uip_stats uip_stat;
+#define UIP_STAT(s) s
+#else
+#define UIP_STAT(s)
+#endif /* UIP_STATISTICS == 1 */
+
+/**
+ * The structure holding the TCP/IP statistics that are gathered if
+ * UIP_STATISTICS is set to 1.
+ *
+ */
+struct uip_stats {
+  struct {
+    uip_stats_t recv;     /**< Number of received packets at the IP
+			     layer. */
+    uip_stats_t sent;     /**< Number of sent packets at the IP
+			     layer. */
+    uip_stats_t forwarded;/**< Number of forwarded packets at the IP
+			     layer. */
+    uip_stats_t drop;     /**< Number of dropped packets at the IP
+			     layer. */
+    uip_stats_t vhlerr;   /**< Number of packets dropped due to wrong
+			     IP version or header length. */
+    uip_stats_t hblenerr; /**< Number of packets dropped due to wrong
+			     IP length, high byte. */
+    uip_stats_t lblenerr; /**< Number of packets dropped due to wrong
+			     IP length, low byte. */
+    uip_stats_t fragerr;  /**< Number of packets dropped since they
+			     were IP fragments. */
+    uip_stats_t chkerr;   /**< Number of packets dropped due to IP
+			     checksum errors. */
+    uip_stats_t protoerr; /**< Number of packets dropped since they
+			     were neither ICMP, UDP nor TCP. */
+  } ip;                   /**< IP statistics. */
+  struct {
+    uip_stats_t recv;     /**< Number of received ICMP packets. */
+    uip_stats_t sent;     /**< Number of sent ICMP packets. */
+    uip_stats_t drop;     /**< Number of dropped ICMP packets. */
+    uip_stats_t typeerr;  /**< Number of ICMP packets with a wrong
+			     type. */
+    uip_stats_t chkerr;   /**< Number of ICMP packets with a bad
+			     checksum. */
+  } icmp;                 /**< ICMP statistics. */
+#if UIP_TCP
+  struct {
+    uip_stats_t recv;     /**< Number of received TCP segments. */
+    uip_stats_t sent;     /**< Number of sent TCP segments. */
+    uip_stats_t drop;     /**< Number of dropped TCP segments. */
+    uip_stats_t chkerr;   /**< Number of TCP segments with a bad
+			     checksum. */
+    uip_stats_t ackerr;   /**< Number of TCP segments with a bad ACK
+			     number. */
+    uip_stats_t rst;      /**< Number of received TCP RST (reset) segments. */
+    uip_stats_t rexmit;   /**< Number of retransmitted TCP segments. */
+    uip_stats_t syndrop;  /**< Number of dropped SYNs due to too few
+			     connections was available. */
+    uip_stats_t synrst;   /**< Number of SYNs for closed ports,
+			     triggering a RST. */
+  } tcp;                  /**< TCP statistics. */
+#endif
+#if UIP_UDP
+  struct {
+    uip_stats_t drop;     /**< Number of dropped UDP segments. */
+    uip_stats_t recv;     /**< Number of received UDP segments. */
+    uip_stats_t sent;     /**< Number of sent UDP segments. */
+    uip_stats_t chkerr;   /**< Number of UDP segments with a bad
+			     checksum. */
+  } udp;                  /**< UDP statistics. */
+#endif /* UIP_UDP */
+#if UIP_CONF_IPV6
+  struct {
+    uip_stats_t drop;     /**< Number of dropped ND6 packets. */
+    uip_stats_t recv;     /**< Number of received ND6 packets */
+    uip_stats_t sent;     /**< Number of sent ND6 packets */
+  } nd6;
+#endif /*UIP_CONF_IPV6*/
+};
+
+
+/*---------------------------------------------------------------------------*/
+/* All the stuff below this point is internal to uIP and should not be
+ * used directly by an application or by a device driver.
+ */
+/*---------------------------------------------------------------------------*/
+
+
+
+/* u8_t uip_flags:
+ *
+ * When the application is called, uip_flags will contain the flags
+ * that are defined in this file. Please read below for more
+ * information.
+ */
+extern u8_t uip_flags;
+
+/* The following flags may be set in the global variable uip_flags
+   before calling the application callback. The UIP_ACKDATA,
+   UIP_NEWDATA, and UIP_CLOSE flags may both be set at the same time,
+   whereas the others are mutually exclusive. Note that these flags
+   should *NOT* be accessed directly, but only through the uIP
+   functions/macros. */
+
+#define UIP_ACKDATA   1     /* Signifies that the outstanding data was
+			       acked and the application should send
+			       out new data instead of retransmitting
+			       the last data. */
+#define UIP_NEWDATA   2     /* Flags the fact that the peer has sent
+			       us new data. */
+#define UIP_REXMIT    4     /* Tells the application to retransmit the
+			       data that was last sent. */
+#define UIP_POLL      8     /* Used for polling the application, to
+			       check if the application has data that
+			       it wants to send. */
+#define UIP_CLOSE     16    /* The remote host has closed the
+			       connection, thus the connection has
+			       gone away. Or the application signals
+			       that it wants to close the
+			       connection. */
+#define UIP_ABORT     32    /* The remote host has aborted the
+			       connection, thus the connection has
+			       gone away. Or the application signals
+			       that it wants to abort the
+			       connection. */
+#define UIP_CONNECTED 64    /* We have got a connection from a remote
+                               host and have set up a new connection
+                               for it, or an active connection has
+                               been successfully established. */
+
+#define UIP_TIMEDOUT  128   /* The connection has been aborted due to
+			       too many retransmissions. */
+
+
+/**
+ * \brief process the options within a hop by hop or destination option header
+ * \retval 0: nothing to send,
+ * \retval 1: drop pkt
+ * \retval 2: ICMP error message to send
+*/
+/*static u8_t
+uip_ext_hdr_options_process(); */
+
+/* uip_process(flag):
+ *
+ * The actual uIP function which does all the work.
+ */
+void uip_process(u8_t flag);
+
+  /* The following flags are passed as an argument to the uip_process()
+   function. They are used to distinguish between the two cases where
+   uip_process() is called. It can be called either because we have
+   incoming data that should be processed, or because the periodic
+   timer has fired. These values are never used directly, but only in
+   the macros defined in this file. */
+
+#define UIP_DATA          1     /* Tells uIP that there is incoming
+				   data in the uip_buf buffer. The
+				   length of the data is stored in the
+				   global variable uip_len. */
+#define UIP_TIMER         2     /* Tells uIP that the periodic timer
+				   has fired. */
+#define UIP_POLL_REQUEST  3     /* Tells uIP that a connection should
+				   be polled. */
+#define UIP_UDP_SEND_CONN 4     /* Tells uIP that a UDP datagram
+				   should be constructed in the
+				   uip_buf buffer. */
+#if UIP_UDP
+#define UIP_UDP_TIMER     5
+#endif /* UIP_UDP */
+
+/* The TCP states used in the uip_conn->tcpstateflags. */
+#define UIP_CLOSED      0
+#define UIP_SYN_RCVD    1
+#define UIP_SYN_SENT    2
+#define UIP_ESTABLISHED 3
+#define UIP_FIN_WAIT_1  4
+#define UIP_FIN_WAIT_2  5
+#define UIP_CLOSING     6
+#define UIP_TIME_WAIT   7
+#define UIP_LAST_ACK    8
+#define UIP_TS_MASK     15
+
+#define UIP_STOPPED      16
+
+/* The TCP and IP headers. */
+struct uip_tcpip_hdr {
+#if UIP_CONF_IPV6
+  /* IPv6 header. */
+  u8_t vtc,
+    tcflow;
+  u16_t flow;
+  u8_t len[2];
+  u8_t proto, ttl;
+  uip_ip6addr_t srcipaddr, destipaddr;
+#else /* UIP_CONF_IPV6 */
+  /* IPv4 header. */
+  u8_t vhl,
+    tos,
+    len[2],
+    ipid[2],
+    ipoffset[2],
+    ttl,
+    proto;
+  u16_t ipchksum;
+  uip_ipaddr_t srcipaddr, destipaddr;
+#endif /* UIP_CONF_IPV6 */
+
+  /* TCP header. */
+  u16_t srcport,
+    destport;
+  u8_t seqno[4],
+    ackno[4],
+    tcpoffset,
+    flags,
+    wnd[2];
+  u16_t tcpchksum;
+  u8_t urgp[2];
+  u8_t optdata[4];
+};
+
+/* The ICMP and IP headers. */
+struct uip_icmpip_hdr {
+#if UIP_CONF_IPV6
+  /* IPv6 header. */
+  u8_t vtc,
+    tcf;
+  u16_t flow;
+  u8_t len[2];
+  u8_t proto, ttl;
+  uip_ip6addr_t srcipaddr, destipaddr;
+#else /* UIP_CONF_IPV6 */
+  /* IPv4 header. */
+  u8_t vhl,
+    tos,
+    len[2],
+    ipid[2],
+    ipoffset[2],
+    ttl,
+    proto;
+  u16_t ipchksum;
+  uip_ipaddr_t srcipaddr, destipaddr;
+#endif /* UIP_CONF_IPV6 */
+
+  /* ICMP header. */
+  u8_t type, icode;
+  u16_t icmpchksum;
+#if !UIP_CONF_IPV6
+  u16_t id, seqno;
+  u8_t payload[1];
+#endif /* !UIP_CONF_IPV6 */
+};
+
+
+/* The UDP and IP headers. */
+struct uip_udpip_hdr {
+#if UIP_CONF_IPV6
+  /* IPv6 header. */
+  u8_t vtc,
+    tcf;
+  u16_t flow;
+  u8_t len[2];
+  u8_t proto, ttl;
+  uip_ip6addr_t srcipaddr, destipaddr;
+#else /* UIP_CONF_IPV6 */
+  /* IP header. */
+  u8_t vhl,
+    tos,
+    len[2],
+    ipid[2],
+    ipoffset[2],
+    ttl,
+    proto;
+  u16_t ipchksum;
+  uip_ipaddr_t srcipaddr, destipaddr;
+#endif /* UIP_CONF_IPV6 */
+
+  /* UDP header. */
+  u16_t srcport,
+    destport;
+  u16_t udplen;
+  u16_t udpchksum;
+};
+
+/*
+ * In IPv6 the length of the L3 headers before the transport header is
+ * not fixed, due to the possibility to include extension option headers
+ * after the IP header. hence we split here L3 and L4 headers
+ */
+/* The IP header */
+struct uip_ip_hdr {
+#if UIP_CONF_IPV6
+  /* IPV6 header */
+  u8_t vtc;
+  u8_t tcflow;
+  u16_t flow;
+  u8_t len[2];
+  u8_t proto, ttl;
+  uip_ip6addr_t srcipaddr, destipaddr;
+#else /* UIP_CONF_IPV6 */
+  /* IPV4 header */
+  u8_t vhl,
+    tos,
+    len[2],
+    ipid[2],
+    ipoffset[2],
+    ttl,
+    proto;
+  u16_t ipchksum;
+  uip_ipaddr_t srcipaddr, destipaddr;
+#endif /* UIP_CONF_IPV6 */
+};
+
+
+/*
+ * IPv6 extension option headers: we are able to process
+ * the 4 extension headers defined in RFC2460 (IPv6):
+ * - Hop by hop option header, destination option header:
+ *   These two are not used by any core IPv6 protocol, hence
+ *   we just read them and go to the next. They convey options,
+ *   the options defined in RFC2460 are Pad1 and PadN, which do
+ *   some padding, and that we do not need to read (the length
+ *   field in the header is enough)
+ * - Routing header: this one is most notably used by MIPv6,
+ *   which we do not implement, hence we just read it and go
+ *   to the next
+ * - Fragmentation header: we read this header and are able to
+ *   reassemble packets
+ *
+ * We do not offer any means to send packets with extension headers
+ *
+ * We do not implement Authentication and ESP headers, which are
+ * used in IPSec and defined in RFC4302,4303,4305,4385
+ */
+/* common header part */
+struct uip_ext_hdr {
+  u8_t next;
+  u8_t len;
+};
+
+/* Hop by Hop option header */
+struct uip_hbho_hdr {
+  u8_t next;
+  u8_t len;
+};
+
+/* destination option header */
+struct uip_desto_hdr {
+  u8_t next;
+  u8_t len;
+};
+
+/* We do not define structures for PAD1 and PADN options */
+
+/*
+ * routing header
+ * the routing header as 4 common bytes, then routing header type
+ * specific data there are several types of routing header. Type 0 was
+ * deprecated as per RFC5095 most notable other type is 2, used in
+ * RFC3775 (MIPv6) here we do not implement MIPv6, so we just need to
+ * parse the 4 first bytes
+ */
+struct uip_routing_hdr {
+  u8_t next;
+  u8_t len;
+  u8_t routing_type;
+  u8_t seg_left;
+};
+
+/* fragmentation header */
+struct uip_frag_hdr {
+  u8_t next;
+  u8_t res;
+  u16_t offsetresmore;
+  u32_t id;
+};
+
+/*
+ * an option within the destination or hop by hop option headers
+ * it contains type an length, which is true for all options but PAD1
+ */
+struct uip_ext_hdr_opt {
+  u8_t type;
+  u8_t len;
+};
+
+/* PADN option */
+struct uip_ext_hdr_opt_padn {
+  u8_t opt_type;
+  u8_t opt_len;
+};
+
+/* TCP header */
+struct uip_tcp_hdr {
+  u16_t srcport;
+  u16_t destport;
+  u8_t seqno[4];
+  u8_t ackno[4];
+  u8_t tcpoffset;
+  u8_t flags;
+  u8_t  wnd[2];
+  u16_t tcpchksum;
+  u8_t urgp[2];
+  u8_t optdata[4];
+};
+
+/* The ICMP headers. */
+struct uip_icmp_hdr {
+  u8_t type, icode;
+  u16_t icmpchksum;
+#if !UIP_CONF_IPV6
+  u16_t id, seqno;
+#endif /* !UIP_CONF_IPV6 */
+};
+
+
+/* The UDP headers. */
+struct uip_udp_hdr {
+  u16_t srcport;
+  u16_t destport;
+  u16_t udplen;
+  u16_t udpchksum;
+};
+
+
+/**
+ * The buffer size available for user data in the \ref uip_buf buffer.
+ *
+ * This macro holds the available size for user data in the \ref
+ * uip_buf buffer. The macro is intended to be used for checking
+ * bounds of available user data.
+ *
+ * Example:
+ \code
+ snprintf(uip_appdata, UIP_APPDATA_SIZE, "%u\n", i);
+ \endcode
+ *
+ * \hideinitializer
+ */
+#define UIP_APPDATA_SIZE (UIP_BUFSIZE - UIP_LLH_LEN - UIP_TCPIP_HLEN)
+#define UIP_APPDATA_PTR (void *)&uip_buf[UIP_LLH_LEN + UIP_TCPIP_HLEN]
+
+#define UIP_PROTO_ICMP  1
+#define UIP_PROTO_TCP   6
+#define UIP_PROTO_UDP   17
+#define UIP_PROTO_ICMP6 58
+
+
+#if UIP_CONF_IPV6
+/** @{ */
+/** \brief  extension headers types */
+#define UIP_PROTO_HBHO        0
+#define UIP_PROTO_DESTO       60
+#define UIP_PROTO_ROUTING     43
+#define UIP_PROTO_FRAG        44
+#define UIP_PROTO_NONE        59
+/** @} */
+
+/** @{ */
+/** \brief  Destination and Hop By Hop extension headers option types */
+#define UIP_EXT_HDR_OPT_PAD1  0
+#define UIP_EXT_HDR_OPT_PADN  1
+/** @} */
+
+/** @{ */
+/**
+ * \brief Bitmaps for extension header processing
+ *
+ * When processing extension headers, we should record somehow which one we
+ * see, because you cannot have twice the same header, except for destination
+ * We store all this in one u8_t bitmap one bit for each header expected. The
+ * order in the bitmap is the order recommended in RFC2460
+ */
+#define UIP_EXT_HDR_BITMAP_HBHO 0x01
+#define UIP_EXT_HDR_BITMAP_DESTO1 0x02
+#define UIP_EXT_HDR_BITMAP_ROUTING 0x04
+#define UIP_EXT_HDR_BITMAP_FRAG 0x08
+#define UIP_EXT_HDR_BITMAP_AH 0x10
+#define UIP_EXT_HDR_BITMAP_ESP 0x20
+#define UIP_EXT_HDR_BITMAP_DESTO2 0x40
+/** @} */
+
+
+#endif /* UIP_CONF_IPV6 */
+
+
+/* Header sizes. */
+#if UIP_CONF_IPV6
+#define UIP_IPH_LEN    40
+#define UIP_FRAGH_LEN  8
+#else /* UIP_CONF_IPV6 */
+#define UIP_IPH_LEN    20    /* Size of IP header */
+#endif /* UIP_CONF_IPV6 */
+
+#define UIP_UDPH_LEN    8    /* Size of UDP header */
+#define UIP_TCPH_LEN   20    /* Size of TCP header */
+#ifdef UIP_IPH_LEN
+#define UIP_ICMPH_LEN   4    /* Size of ICMP header */
+#endif
+#define UIP_IPUDPH_LEN (UIP_UDPH_LEN + UIP_IPH_LEN)    /* Size of IP +
+                        * UDP
+							   * header */
+#define UIP_IPTCPH_LEN (UIP_TCPH_LEN + UIP_IPH_LEN)    /* Size of IP +
+							   * TCP
+							   * header */
+#define UIP_TCPIP_HLEN UIP_IPTCPH_LEN
+#define UIP_IPICMPH_LEN (UIP_IPH_LEN + UIP_ICMPH_LEN) /* size of ICMP
+                                                         + IP header */
+#define UIP_LLIPH_LEN (UIP_LLH_LEN + UIP_IPH_LEN)    /* size of L2
+                                                        + IP header */
+#if UIP_CONF_IPV6
+/**
+ * The sums below are quite used in ND. When used for uip_buf, we
+ * include link layer length when used for uip_len, we do not, hence
+ * we need values with and without LLH_LEN we do not use capital
+ * letters as these values are variable
+ */
+#define uip_l2_l3_hdr_len (UIP_LLH_LEN + UIP_IPH_LEN + uip_ext_len)
+#define uip_l2_l3_icmp_hdr_len (UIP_LLH_LEN + UIP_IPH_LEN + uip_ext_len + UIP_ICMPH_LEN)
+#define uip_l3_hdr_len (UIP_IPH_LEN + uip_ext_len)
+#define uip_l3_icmp_hdr_len (UIP_IPH_LEN + uip_ext_len + UIP_ICMPH_LEN)
+#endif /*UIP_CONF_IPV6*/
+
+
+#if UIP_FIXEDADDR
+extern const uip_ipaddr_t uip_hostaddr, uip_netmask, uip_draddr;
+#else /* UIP_FIXEDADDR */
+extern uip_ipaddr_t uip_hostaddr, uip_netmask, uip_draddr;
+#endif /* UIP_FIXEDADDR */
+extern const uip_ipaddr_t uip_broadcast_addr;
+extern const uip_ipaddr_t uip_all_zeroes_addr;
+
+#if UIP_FIXEDETHADDR
+extern const uip_lladdr_t uip_lladdr;
+#else
+extern uip_lladdr_t uip_lladdr;
+#endif
+
+
+
+
+#ifdef UIP_CONF_IPV6
+/**
+ * \brief Is IPv6 address a the unspecified address
+ * a is of type uip_ipaddr_t
+ */
+#define uip_is_addr_unspecified(a)               \
+  ((((a)->u16[0]) == 0) &&                       \
+   (((a)->u16[1]) == 0) &&                       \
+   (((a)->u16[2]) == 0) &&                       \
+   (((a)->u16[3]) == 0) &&                       \
+   (((a)->u16[4]) == 0) &&                       \
+   (((a)->u16[5]) == 0) &&                       \
+   (((a)->u16[6]) == 0) &&                       \
+   (((a)->u16[7]) == 0))
+
+/** \brief Is IPv6 address a the link local all-nodes multicast address */
+#define uip_is_addr_linklocal_allnodes_mcast(a)     \
+  ((((a)->u8[0]) == 0xff) &&                        \
+   (((a)->u8[1]) == 0x02) &&                        \
+   (((a)->u16[1]) == 0) &&                          \
+   (((a)->u16[2]) == 0) &&                          \
+   (((a)->u16[3]) == 0) &&                          \
+   (((a)->u16[4]) == 0) &&                          \
+   (((a)->u16[5]) == 0) &&                          \
+   (((a)->u16[6]) == 0) &&                          \
+   (((a)->u8[14]) == 0) &&                          \
+   (((a)->u8[15]) == 0x01))
+
+/** \brief set IP address a to unspecified */
+#define uip_create_unspecified(a) uip_ip6addr(a, 0, 0, 0, 0, 0, 0, 0, 0)
+
+/** \brief set IP address a to the link local all-nodes multicast address */
+#define uip_create_linklocal_allnodes_mcast(a) uip_ip6addr(a, 0xff02, 0, 0, 0, 0, 0, 0, 0x0001)
+
+/** \brief set IP address a to the link local all-routers multicast address */
+#define uip_create_linklocal_allrouters_mcast(a) uip_ip6addr(a, 0xff02, 0, 0, 0, 0, 0, 0, 0x0002)
+
+/**
+ * \brief  is addr (a) a solicited node multicast address, see RFC3513
+ *  a is of type uip_ipaddr_t*
+ */
+#define uip_is_addr_solicited_node(a)           \
+  ((((a)->u8[0]) == 0xFF) &&                     \
+  (((a)->u8[1]) == 0x02) &&                     \
+  (((a)->u16[1]) == 0) &&                       \
+  (((a)->u16[2]) == 0) &&                       \
+  (((a)->u16[3]) == 0) &&                       \
+  (((a)->u16[4]) == 0) &&                       \
+  (((a)->u16[5]) == 1) &&                       \
+  (((a)->u8[12]) == 0xFF))
+
+/**
+ * \briefput in b the solicited node address corresponding to address a
+ * both a and b are of type uip_ipaddr_t*
+ * */
+#define uip_create_solicited_node(a, b)    \
+  (((b)->u8[0]) = 0xFF);                        \
+  (((b)->u8[1]) = 0x02);                        \
+  (((b)->u16[1]) = 0);                          \
+  (((b)->u16[2]) = 0);                          \
+  (((b)->u16[3]) = 0);                          \
+  (((b)->u16[4]) = 0);                          \
+  (((b)->u8[10]) = 0);                          \
+  (((b)->u8[11]) = 0x01);                       \
+  (((b)->u8[12]) = 0xFF);                       \
+  (((b)->u8[13]) = ((a)->u8[13]));              \
+  (((b)->u16[7]) = ((a)->u16[7]))
+
+/**
+ * \brief is addr (a) a link local unicast address, see RFC3513
+ *  i.e. is (a) on prefix FE80::/10
+ *  a is of type uip_ipaddr_t*
+ */
+#define uip_is_addr_link_local(a) \
+  ((((a)->u8[0]) == 0xFE) && \
+  (((a)->u8[1]) == 0x80))
+
+/**
+ * \brief was addr (a) forged based on the mac address m
+ * a type is uip_ipaddr_t
+ * m type is uiplladdr_t
+ */
+#if UIP_CONF_LL_802154
+#define uip_is_addr_mac_addr_based(a, m) \
+  ((((a)->u8[8])  == (((m)->addr[0]) ^ 0x02)) &&   \
+   (((a)->u8[9])  == (m)->addr[1]) &&            \
+   (((a)->u8[10]) == (m)->addr[2]) &&            \
+   (((a)->u8[11]) == (m)->addr[3]) &&            \
+   (((a)->u8[12]) == (m)->addr[4]) &&            \
+   (((a)->u8[13]) == (m)->addr[5]) &&            \
+   (((a)->u8[14]) == (m)->addr[6]) &&            \
+   (((a)->u8[15]) == (m)->addr[7]))
+#else
+
+#define uip_is_addr_mac_addr_based(a, m) \
+  ((((a)->u8[8])  == (((m)->addr[0]) | 0x02)) &&   \
+   (((a)->u8[9])  == (m)->addr[1]) &&            \
+   (((a)->u8[10]) == (m)->addr[2]) &&            \
+   (((a)->u8[11]) == 0xff) &&            \
+   (((a)->u8[12]) == 0xfe) &&            \
+   (((a)->u8[13]) == (m)->addr[3]) &&            \
+   (((a)->u8[14]) == (m)->addr[4]) &&            \
+   (((a)->u8[15]) == (m)->addr[5]))
+
+#endif /*UIP_CONF_LL_802154*/
+
+/**
+ * \brief is address a multicast address, see RFC 3513
+ * a is of type uip_ipaddr_t*
+ * */
+#define uip_is_addr_mcast(a)                    \
+  (((a)->u8[0]) == 0xFF)
+
+/**
+ * \brief is group-id of multicast address a
+ * the all nodes group-id
+ */
+#define uip_is_mcast_group_id_all_nodes(a) \
+  ((((a)->u16[1])  == 0) &&                 \
+   (((a)->u16[2])  == 0) &&                 \
+   (((a)->u16[3])  == 0) &&                 \
+   (((a)->u16[4])  == 0) &&                 \
+   (((a)->u16[5])  == 0) &&                 \
+   (((a)->u16[6])  == 0) &&                 \
+   (((a)->u8[14])  == 0) &&                 \
+   (((a)->u8[15])  == 1))
+
+/**
+ * \brief is group-id of multicast address a
+ * the all routers group-id
+ */
+#define uip_is_mcast_group_id_all_routers(a) \
+  ((((a)->u16[1])  == 0) &&                 \
+   (((a)->u16[2])  == 0) &&                 \
+   (((a)->u16[3])  == 0) &&                 \
+   (((a)->u16[4])  == 0) &&                 \
+   (((a)->u16[5])  == 0) &&                 \
+   (((a)->u16[6])  == 0) &&                 \
+   (((a)->u8[14])  == 0) &&                 \
+   (((a)->u8[15])  == 2))
+
+
+#endif /*UIP_CONF_IPV6*/
+
+/**
+ * Calculate the Internet checksum over a buffer.
+ *
+ * The Internet checksum is the one's complement of the one's
+ * complement sum of all 16-bit words in the buffer.
+ *
+ * See RFC1071.
+ *
+ * \param buf A pointer to the buffer over which the checksum is to be
+ * computed.
+ *
+ * \param len The length of the buffer over which the checksum is to
+ * be computed.
+ *
+ * \return The Internet checksum of the buffer.
+ */
+u16_t uip_chksum(u16_t *buf, u16_t len);
+
+/**
+ * Calculate the IP header checksum of the packet header in uip_buf.
+ *
+ * The IP header checksum is the Internet checksum of the 20 bytes of
+ * the IP header.
+ *
+ * \return The IP header checksum of the IP header in the uip_buf
+ * buffer.
+ */
+u16_t uip_ipchksum(void);
+
+/**
+ * Calculate the TCP checksum of the packet in uip_buf and uip_appdata.
+ *
+ * The TCP checksum is the Internet checksum of data contents of the
+ * TCP segment, and a pseudo-header as defined in RFC793.
+ *
+ * \return The TCP checksum of the TCP segment in uip_buf and pointed
+ * to by uip_appdata.
+ */
+u16_t uip_tcpchksum(void);
+
+/**
+ * Calculate the UDP checksum of the packet in uip_buf and uip_appdata.
+ *
+ * The UDP checksum is the Internet checksum of data contents of the
+ * UDP segment, and a pseudo-header as defined in RFC768.
+ *
+ * \return The UDP checksum of the UDP segment in uip_buf and pointed
+ * to by uip_appdata.
+ */
+u16_t uip_udpchksum(void);
+
+/**
+ * Calculate the ICMP checksum of the packet in uip_buf.
+ *
+ * \return The ICMP checksum of the ICMP packet in uip_buf
+ */
+u16_t uip_icmp6chksum(void);
+
+
+#endif /* __UIP_H__ */
+
+
+/** @} */
+