/*
 * Copyright (c) 2001-2003 Swedish Institute of Computer Science.
 * 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 lwIP TCP/IP stack.
 * 
 * Author: Adam Dunkels <adam@sics.se>
 *
 */
#ifndef __LWIP_OPT_H__
#define __LWIP_OPT_H__

#include "lwip/debug.h"
/* Include user defined options first */
#include "lwipopts.h"
#include "lib.h" // add by zhigang 2004-2-1

/* Define default values for unconfigured parameters. */

/* Platform specific locking */

/*
 * enable SYS_LIGHTWEIGHT_PROT in lwipopts.h if you want inter-task protection
 * for certain critical regions during buffer allocation, deallocation and memory
 * allocation and deallocation.
 */
#ifndef SYS_LIGHTWEIGHT_PROT
#define SYS_LIGHTWEIGHT_PROT            0
#endif

#ifndef NO_SYS
#define NO_SYS                          0
#endif
/* ---------- Memory options ---------- */
/* MEM_ALIGNMENT: should be set to the alignment of the CPU for which
   lwIP is compiled. 4 byte alignment -> define MEM_ALIGNMENT to 4, 2
   byte alignment -> define MEM_ALIGNMENT to 2. */

#ifndef MEM_ALIGNMENT
#define MEM_ALIGNMENT                   1
#endif

/* MEM_SIZE: the size of the heap memory. If the application will send
a lot of data that needs to be copied, this should be set high. */
#ifndef MEM_SIZE
#define MEM_SIZE                        1600
#endif

/* MEMP_NUM_PBUF: the number of memp struct pbufs. If the application
   sends a lot of data out of ROM (or other static memory), this
   should be set high. */
#ifndef MEMP_NUM_PBUF
#define MEMP_NUM_PBUF                   16
#endif

/* MEMP_NUM_UDP_PCB: the number of UDP protocol control blocks. One
   per active UDP "connection". */
#ifndef MEMP_NUM_UDP_PCB
#define MEMP_NUM_UDP_PCB                4
#endif
/* MEMP_NUM_TCP_PCB: the number of simulatenously active TCP
   connections. */
#ifndef MEMP_NUM_TCP_PCB
#define MEMP_NUM_TCP_PCB                5
#endif
/* MEMP_NUM_TCP_PCB_LISTEN: the number of listening TCP
   connections. */
#ifndef MEMP_NUM_TCP_PCB_LISTEN
#define MEMP_NUM_TCP_PCB_LISTEN         8
#endif
/* MEMP_NUM_TCP_SEG: the number of simultaneously queued TCP
   segments. */
#ifndef MEMP_NUM_TCP_SEG
#define MEMP_NUM_TCP_SEG                16
#endif
/* MEMP_NUM_SYS_TIMEOUT: the number of simulateously active
   timeouts. */
#ifndef MEMP_NUM_SYS_TIMEOUT
#define MEMP_NUM_SYS_TIMEOUT            3
#endif

/* The following four are used only with the sequential API and can be
   set to 0 if the application only will use the raw API. */
/* MEMP_NUM_NETBUF: the number of struct netbufs. */
#ifndef MEMP_NUM_NETBUF
#define MEMP_NUM_NETBUF                 2
#endif
/* MEMP_NUM_NETCONN: the number of struct netconns. */
#ifndef MEMP_NUM_NETCONN
#define MEMP_NUM_NETCONN                4
#endif
/* MEMP_NUM_APIMSG: the number of struct api_msg, used for
   communication between the TCP/IP stack and the sequential
   programs. */
#ifndef MEMP_NUM_API_MSG
#define MEMP_NUM_API_MSG                8
#endif
/* MEMP_NUM_TCPIPMSG: the number of struct tcpip_msg, which is used
   for sequential API communication and incoming packets. Used in
   src/api/tcpip.c. */
#ifndef MEMP_NUM_TCPIP_MSG
#define MEMP_NUM_TCPIP_MSG              8
#endif

/* ---------- Pbuf options ---------- */
/* PBUF_POOL_SIZE: the number of buffers in the pbuf pool. */

#ifndef PBUF_POOL_SIZE
#define PBUF_POOL_SIZE                  16
#endif

/* PBUF_POOL_BUFSIZE: the size of each pbuf in the pbuf pool. */

#ifndef PBUF_POOL_BUFSIZE
#define PBUF_POOL_BUFSIZE               128
#endif

/* PBUF_LINK_HLEN: the number of bytes that should be allocated for a
   link level header. */

#ifndef PBUF_LINK_HLEN
#define PBUF_LINK_HLEN                  0
#endif



/* ---------- ARP options ---------- */

/** Number of active hardware address, IP address pairs cached */
#ifndef ARP_TABLE_SIZE
#define ARP_TABLE_SIZE                  10
#endif

/**
 * If enabled, outgoing packets are queued during hardware address
 * resolution. The etharp.c implementation queues 1 packet only.
 */
#ifndef ARP_QUEUEING
#define ARP_QUEUEING                    1
#endif
/** If enabled, the first packet queued will not be overwritten by
 * later packets. If disabled, later packets overwrite early packets
 * in the queue. Default is disabled, which is recommended. 
 */
#ifndef ARP_QUEUE_FIRST
#define ARP_QUEUE_FIRST                 0
#endif
/**
 * If defined to 1, cache entries are updated or added for every kind of ARP traffic
 * or broadcast IP traffic. Recommended for routers.
 * If defined to 0, only existing cache entries are updated. Entries are added when
 * lwIP is sending to them. Recommended for embedded devices.
 */
#ifndef ETHARP_ALWAYS_INSERT
#define ETHARP_ALWAYS_INSERT            1
#endif

/* ---------- IP options ---------- */
/* Define IP_FORWARD to 1 if you wish to have the ability to forward
   IP packets across network interfaces. If you are going to run lwIP
   on a device with only one network interface, define this to 0. */
#ifndef IP_FORWARD
#define IP_FORWARD                      0
#endif

/* If defined to 1, IP options are allowed (but not parsed). If
   defined to 0, all packets with IP options are dropped. */
#ifndef IP_OPTIONS
#define IP_OPTIONS                      1
#endif

/** IP reassembly and segmentation. Even if they both deal with IP
 *  fragments, note that these are orthogonal, one dealing with incoming
 *  packets, the other with outgoing packets
 */

/** Reassemble incoming fragmented IP packets */
#ifndef IP_REASSEMBLY
#define IP_REASSEMBLY                   1
#endif

/** Fragment outgoing IP packets if their size exceeds MTU */
#ifndef IP_FRAG
#define IP_FRAG                         1
#endif

/* ---------- ICMP options ---------- */

#ifndef ICMP_TTL
#define ICMP_TTL                        255
#endif

/* ---------- DHCP options ---------- */

#ifndef LWIP_DHCP
#define LWIP_DHCP                       0
#endif

/* 1 if you want to do an ARP check on the offered address
   (recommended). */
#ifndef DHCP_DOES_ARP_CHECK
#define DHCP_DOES_ARP_CHECK             1
#endif

/* ---------- UDP options ---------- */
#ifndef LWIP_UDP
#define LWIP_UDP                        1
#endif

#ifndef UDP_TTL
#define UDP_TTL                         255
#endif

/* ---------- TCP options ---------- */
#ifndef LWIP_TCP
#define LWIP_TCP                        1
#endif

#ifndef TCP_TTL
#define TCP_TTL                         255
#endif

#ifndef TCP_WND
#define TCP_WND                         2048
#endif 

#ifndef TCP_MAXRTX
#define TCP_MAXRTX                      12
#endif

#ifndef TCP_SYNMAXRTX
#define TCP_SYNMAXRTX                   6
#endif


/* Controls if TCP should queue segments that arrive out of
   order. Define to 0 if your device is low on memory. */
#ifndef TCP_QUEUE_OOSEQ
#define TCP_QUEUE_OOSEQ                 1
#endif

/* TCP Maximum segment size. */
#ifndef TCP_MSS
#define TCP_MSS                         128 /* A *very* conservative default. */
#endif

/* TCP sender buffer space (bytes). */
#ifndef TCP_SND_BUF
#define TCP_SND_BUF                     256
#endif

/* TCP sender buffer space (pbufs). This must be at least = 2 *
   TCP_SND_BUF/TCP_MSS for things to work. */
#ifndef TCP_SND_QUEUELEN
#define TCP_SND_QUEUELEN                4 * TCP_SND_BUF/TCP_MSS
#endif


/* Maximum number of retransmissions of data segments. */