opt.h File Reference

#include "lwipopts.h"
#include "lwip/debug.h"

Defines
#define	SYS_LIGHTWEIGHT_PROT   0
#define	NO_SYS   0
#define	NO_SYS_NO_TIMERS   0
#define	MEMCPY(dst, src, len)   memcpy(dst,src,len)
#define	SMEMCPY(dst, src, len)   memcpy(dst,src,len)
#define	MEM_LIBC_MALLOC   0
#define	MEMP_MEM_MALLOC   0
#define	MEM_ALIGNMENT   1
#define	MEM_SIZE   1600
#define	MEMP_SEPARATE_POOLS   0
#define	MEMP_OVERFLOW_CHECK   0
#define	MEMP_SANITY_CHECK   0
#define	MEM_USE_POOLS   0
#define	MEM_USE_POOLS_TRY_BIGGER_POOL   0
#define	MEMP_USE_CUSTOM_POOLS   0
#define	LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT   0
#define	MEMP_NUM_PBUF   16
#define	MEMP_NUM_RAW_PCB   4
#define	MEMP_NUM_UDP_PCB   4
#define	MEMP_NUM_TCP_PCB   5
#define	MEMP_NUM_TCP_PCB_LISTEN   8
#define	MEMP_NUM_TCP_SEG   16
#define	MEMP_NUM_REASSDATA   5
#define	MEMP_NUM_FRAG_PBUF   15
#define	MEMP_NUM_ARP_QUEUE   30
#define	MEMP_NUM_IGMP_GROUP   8
#define	MEMP_NUM_SYS_TIMEOUT   3
#define	MEMP_NUM_NETBUF   2
#define	MEMP_NUM_NETCONN   4
#define	MEMP_NUM_TCPIP_MSG_API   8
#define	MEMP_NUM_TCPIP_MSG_INPKT   8
#define	MEMP_NUM_SNMP_NODE   50
#define	MEMP_NUM_SNMP_ROOTNODE   30
#define	MEMP_NUM_SNMP_VARBIND   2
#define	MEMP_NUM_SNMP_VALUE   3
#define	MEMP_NUM_NETDB   1
#define	MEMP_NUM_LOCALHOSTLIST   1
#define	MEMP_NUM_PPPOE_INTERFACES   1
#define	PBUF_POOL_SIZE   16
#define	LWIP_ARP   1
#define	ARP_TABLE_SIZE   10
#define	ARP_QUEUEING   0
#define	ETHARP_TRUST_IP_MAC   0
#define	ETHARP_SUPPORT_VLAN   0
#define	LWIP_ETHERNET   (LWIP_ARP || PPPOE_SUPPORT)
#define	ETH_PAD_SIZE   0
#define	ETHARP_SUPPORT_STATIC_ENTRIES   0
#define	IP_FORWARD   0
#define	IP_OPTIONS_ALLOWED   1
#define	IP_REASSEMBLY   1
#define	IP_FRAG   1
#define	IP_REASS_MAXAGE   3
#define	IP_REASS_MAX_PBUFS   10
#define	IP_FRAG_USES_STATIC_BUF   0
#define	IP_DEFAULT_TTL   255
#define	IP_SOF_BROADCAST   0
#define	IP_SOF_BROADCAST_RECV   0
#define	LWIP_ICMP   1
#define	ICMP_TTL   (IP_DEFAULT_TTL)
#define	LWIP_BROADCAST_PING   0
#define	LWIP_MULTICAST_PING   0
#define	LWIP_RAW   1
#define	RAW_TTL   (IP_DEFAULT_TTL)
#define	LWIP_DHCP   0
#define	DHCP_DOES_ARP_CHECK   ((LWIP_DHCP) && (LWIP_ARP))
#define	LWIP_AUTOIP   0
#define	LWIP_DHCP_AUTOIP_COOP   0
#define	LWIP_DHCP_AUTOIP_COOP_TRIES   9
#define	LWIP_SNMP   0
#define	SNMP_CONCURRENT_REQUESTS   1
#define	SNMP_TRAP_DESTINATIONS   1
#define	SNMP_PRIVATE_MIB   0
#define	SNMP_SAFE_REQUESTS   1
#define	SNMP_MAX_OCTET_STRING_LEN   127
#define	SNMP_MAX_TREE_DEPTH   15
#define	SNMP_MAX_VALUE_SIZE   LWIP_MAX((SNMP_MAX_OCTET_STRING_LEN)+1, sizeof(s32_t)*(SNMP_MAX_TREE_DEPTH))
#define	LWIP_IGMP   0
#define	LWIP_DNS   0
#define	DNS_TABLE_SIZE   4
#define	DNS_MAX_NAME_LENGTH   256
#define	DNS_MAX_SERVERS   2
#define	DNS_DOES_NAME_CHECK   1
#define	DNS_MSG_SIZE   512
#define	DNS_LOCAL_HOSTLIST   0
#define	DNS_LOCAL_HOSTLIST_IS_DYNAMIC   0
#define	LWIP_UDP   1
#define	LWIP_UDPLITE   0
#define	UDP_TTL   (IP_DEFAULT_TTL)
#define	LWIP_NETBUF_RECVINFO   0
#define	LWIP_TCP   1
#define	TCP_TTL   (IP_DEFAULT_TTL)
#define	TCP_WND   (4 * TCP_MSS)
#define	TCP_MAXRTX   12
#define	TCP_SYNMAXRTX   6
#define	TCP_QUEUE_OOSEQ   (LWIP_TCP)
#define	TCP_MSS   536
#define	TCP_CALCULATE_EFF_SEND_MSS   1
#define	TCP_SND_BUF   256
#define	TCP_SND_QUEUELEN   ((4 * (TCP_SND_BUF) + (TCP_MSS - 1))/(TCP_MSS))
#define	TCP_SNDLOWAT   ((TCP_SND_BUF)/2)
#define	TCP_SNDQUEUELOWAT   ((TCP_SND_QUEUELEN)/2)
#define	TCP_LISTEN_BACKLOG   0
#define	TCP_DEFAULT_LISTEN_BACKLOG   0xff
#define	TCP_OVERSIZE   TCP_MSS
#define	LWIP_TCP_TIMESTAMPS   0
#define	TCP_WND_UPDATE_THRESHOLD   (TCP_WND / 4)
#define	LWIP_EVENT_API   0
#define	PBUF_LINK_HLEN   (14 + ETH_PAD_SIZE)
#define	PBUF_POOL_BUFSIZE   LWIP_MEM_ALIGN_SIZE(TCP_MSS+40+PBUF_LINK_HLEN)
#define	LWIP_NETIF_HOSTNAME   0
#define	LWIP_NETIF_API   0
#define	LWIP_NETIF_STATUS_CALLBACK   0
#define	LWIP_NETIF_LINK_CALLBACK   0
#define	LWIP_NETIF_HWADDRHINT   0
#define	LWIP_NETIF_LOOPBACK   0
#define	LWIP_LOOPBACK_MAX_PBUFS   0
#define	LWIP_NETIF_LOOPBACK_MULTITHREADING   (!NO_SYS)
#define	LWIP_NETIF_TX_SINGLE_PBUF   0
#define	LWIP_HAVE_LOOPIF   0
#define	LWIP_HAVE_SLIPIF   0
#define	TCPIP_THREAD_NAME   "tcpip_thread"
#define	TCPIP_THREAD_STACKSIZE   0
#define	TCPIP_THREAD_PRIO   1
#define	TCPIP_MBOX_SIZE   0
#define	SLIPIF_THREAD_NAME   "slipif_loop"
#define	SLIPIF_THREAD_STACKSIZE   0
#define	SLIPIF_THREAD_PRIO   1
#define	PPP_THREAD_NAME   "pppInputThread"
#define	PPP_THREAD_STACKSIZE   0
#define	PPP_THREAD_PRIO   1
#define	DEFAULT_THREAD_NAME   "lwIP"
#define	DEFAULT_THREAD_STACKSIZE   0
#define	DEFAULT_THREAD_PRIO   1
#define	DEFAULT_RAW_RECVMBOX_SIZE   0
#define	DEFAULT_UDP_RECVMBOX_SIZE   0
#define	DEFAULT_TCP_RECVMBOX_SIZE   0
#define	DEFAULT_ACCEPTMBOX_SIZE   0
#define	LWIP_TCPIP_CORE_LOCKING   0
#define	LWIP_TCPIP_CORE_LOCKING_INPUT   0
#define	LWIP_NETCONN   1
#define	LWIP_TCPIP_TIMEOUT   1
#define	LWIP_SOCKET   1
#define	LWIP_COMPAT_SOCKETS   1
#define	LWIP_POSIX_SOCKETS_IO_NAMES   1
#define	LWIP_TCP_KEEPALIVE   0
#define	LWIP_SO_RCVTIMEO   0
#define	LWIP_SO_RCVBUF   0
#define	RECV_BUFSIZE_DEFAULT   INT_MAX
#define	SO_REUSE   0
#define	SO_REUSE_RXTOALL   0
#define	LWIP_STATS   1
#define	LWIP_STATS_DISPLAY   0
#define	LINK_STATS   1
#define	ETHARP_STATS   (LWIP_ARP)
#define	IP_STATS   1
#define	IPFRAG_STATS   (IP_REASSEMBLY || IP_FRAG)
#define	ICMP_STATS   1
#define	IGMP_STATS   (LWIP_IGMP)
#define	UDP_STATS   (LWIP_UDP)
#define	TCP_STATS   (LWIP_TCP)
#define	MEM_STATS   ((MEM_LIBC_MALLOC == 0) && (MEM_USE_POOLS == 0))
#define	MEMP_STATS   (MEMP_MEM_MALLOC == 0)
#define	SYS_STATS   (NO_SYS == 0)
#define	PPP_SUPPORT   0
#define	PPPOE_SUPPORT   0
#define	PPPOS_SUPPORT   PPP_SUPPORT
#define	CHECKSUM_GEN_IP   1
#define	CHECKSUM_GEN_UDP   1
#define	CHECKSUM_GEN_TCP   1
#define	CHECKSUM_CHECK_IP   1
#define	CHECKSUM_CHECK_UDP   1
#define	CHECKSUM_CHECK_TCP   1
#define	LWIP_CHECKSUM_ON_COPY   0
#define	LWIP_DBG_MIN_LEVEL   LWIP_DBG_LEVEL_ALL
#define	LWIP_DBG_TYPES_ON   LWIP_DBG_ON
#define	ETHARP_DEBUG   LWIP_DBG_OFF
#define	NETIF_DEBUG   LWIP_DBG_OFF
#define	PBUF_DEBUG   LWIP_DBG_OFF
#define	API_LIB_DEBUG   LWIP_DBG_OFF
#define	API_MSG_DEBUG   LWIP_DBG_OFF
#define	SOCKETS_DEBUG   LWIP_DBG_OFF
#define	ICMP_DEBUG   LWIP_DBG_OFF
#define	IGMP_DEBUG   LWIP_DBG_OFF
#define	INET_DEBUG   LWIP_DBG_OFF
#define	IP_DEBUG   LWIP_DBG_OFF
#define	IP_REASS_DEBUG   LWIP_DBG_OFF
#define	RAW_DEBUG   LWIP_DBG_OFF
#define	MEM_DEBUG   LWIP_DBG_OFF
#define	MEMP_DEBUG   LWIP_DBG_OFF
#define	SYS_DEBUG   LWIP_DBG_OFF
#define	TIMERS_DEBUG   LWIP_DBG_OFF
#define	TCP_DEBUG   LWIP_DBG_OFF
#define	TCP_INPUT_DEBUG   LWIP_DBG_OFF
#define	TCP_FR_DEBUG   LWIP_DBG_OFF
#define	TCP_RTO_DEBUG   LWIP_DBG_OFF
#define	TCP_CWND_DEBUG   LWIP_DBG_OFF
#define	TCP_WND_DEBUG   LWIP_DBG_OFF
#define	TCP_OUTPUT_DEBUG   LWIP_DBG_OFF
#define	TCP_RST_DEBUG   LWIP_DBG_OFF
#define	TCP_QLEN_DEBUG   LWIP_DBG_OFF
#define	UDP_DEBUG   LWIP_DBG_OFF
#define	TCPIP_DEBUG   LWIP_DBG_OFF
#define	PPP_DEBUG   LWIP_DBG_OFF
#define	SLIP_DEBUG   LWIP_DBG_OFF
#define	DHCP_DEBUG   LWIP_DBG_OFF
#define	AUTOIP_DEBUG   LWIP_DBG_OFF
#define	SNMP_MSG_DEBUG   LWIP_DBG_OFF
#define	SNMP_MIB_DEBUG   LWIP_DBG_OFF
#define	DNS_DEBUG   LWIP_DBG_OFF

---

Detailed Description

lwIP Options Configuration

---

Define Documentation

#define API_LIB_DEBUG   LWIP_DBG_OFF

API_LIB_DEBUG: Enable debugging in api_lib.c.

#define API_MSG_DEBUG   LWIP_DBG_OFF

API_MSG_DEBUG: Enable debugging in api_msg.c.

#define ARP_QUEUEING   0

ARP_QUEUEING==1: Multiple outgoing packets are queued during hardware address resolution. By default, only the most recent packet is queued per IP address. This is sufficient for most protocols and mainly reduces TCP connection startup time. Set this to 1 if you know your application sends more than one packet in a row to an IP address that is not in the ARP cache.

#define ARP_TABLE_SIZE   10

ARP_TABLE_SIZE: Number of active MAC-IP address pairs cached.

#define AUTOIP_DEBUG   LWIP_DBG_OFF

AUTOIP_DEBUG: Enable debugging in autoip.c.

#define CHECKSUM_CHECK_IP   1

CHECKSUM_CHECK_IP==1: Check checksums in software for incoming IP packets.

#define CHECKSUM_CHECK_TCP   1

CHECKSUM_CHECK_TCP==1: Check checksums in software for incoming TCP packets.

#define CHECKSUM_CHECK_UDP   1

CHECKSUM_CHECK_UDP==1: Check checksums in software for incoming UDP packets.

#define CHECKSUM_GEN_IP   1

CHECKSUM_GEN_IP==1: Generate checksums in software for outgoing IP packets.

#define CHECKSUM_GEN_TCP   1

CHECKSUM_GEN_TCP==1: Generate checksums in software for outgoing TCP packets.

#define CHECKSUM_GEN_UDP   1

CHECKSUM_GEN_UDP==1: Generate checksums in software for outgoing UDP packets.

#define DEFAULT_ACCEPTMBOX_SIZE   0

DEFAULT_ACCEPTMBOX_SIZE: The mailbox size for the incoming connections. The queue size value itself is platform-dependent, but is passed to sys_mbox_new() when the acceptmbox is created.

#define DEFAULT_RAW_RECVMBOX_SIZE   0

DEFAULT_RAW_RECVMBOX_SIZE: The mailbox size for the incoming packets on a NETCONN_RAW. The queue size value itself is platform-dependent, but is passed to sys_mbox_new() when the recvmbox is created.

#define DEFAULT_TCP_RECVMBOX_SIZE   0

DEFAULT_TCP_RECVMBOX_SIZE: The mailbox size for the incoming packets on a NETCONN_TCP. The queue size value itself is platform-dependent, but is passed to sys_mbox_new() when the recvmbox is created.

#define DEFAULT_THREAD_NAME   "lwIP"

DEFAULT_THREAD_NAME: The name assigned to any other lwIP thread.

#define DEFAULT_THREAD_PRIO   1

DEFAULT_THREAD_PRIO: The priority assigned to any other lwIP thread. The priority value itself is platform-dependent, but is passed to sys_thread_new() when the thread is created.

#define DEFAULT_THREAD_STACKSIZE   0

DEFAULT_THREAD_STACKSIZE: The stack size used by any other lwIP thread. The stack size value itself is platform-dependent, but is passed to sys_thread_new() when the thread is created.

#define DEFAULT_UDP_RECVMBOX_SIZE   0

DEFAULT_UDP_RECVMBOX_SIZE: The mailbox size for the incoming packets on a NETCONN_UDP. The queue size value itself is platform-dependent, but is passed to sys_mbox_new() when the recvmbox is created.

#define DHCP_DEBUG   LWIP_DBG_OFF

DHCP_DEBUG: Enable debugging in dhcp.c.

#define DHCP_DOES_ARP_CHECK   ((LWIP_DHCP) && (LWIP_ARP))

DHCP_DOES_ARP_CHECK==1: Do an ARP check on the offered address.

#define DNS_DEBUG   LWIP_DBG_OFF

DNS_DEBUG: Enable debugging for DNS.

#define DNS_DOES_NAME_CHECK   1

DNS do a name checking between the query and the response.

#define DNS_LOCAL_HOSTLIST   0

DNS_LOCAL_HOSTLIST: Implements a local host-to-address list. If enabled, you have to define define DNS_LOCAL_HOSTLIST_INIT {{"host1", 0x123}, {"host2", 0x234}} (an array of structs name/address, where address is an u32_t in network byte order). Instead, you can also use an external function: define DNS_LOOKUP_LOCAL_EXTERN(x) extern u32_t my_lookup_function(const char *name) that returns the IP address or INADDR_NONE if not found.

#define DNS_LOCAL_HOSTLIST_IS_DYNAMIC   0

If this is turned on, the local host-list can be dynamically changed at runtime.

#define DNS_MAX_NAME_LENGTH   256

DNS maximum host name length supported in the name table.

#define DNS_MAX_SERVERS   2

The maximum of DNS servers

#define DNS_MSG_SIZE   512

DNS message max. size. Default value is RFC compliant.

#define DNS_TABLE_SIZE   4

DNS maximum number of entries to maintain locally.

#define ETH_PAD_SIZE   0

ETH_PAD_SIZE: number of bytes added before the ethernet header to ensure alignment of payload after that header. Since the header is 14 bytes long, without this padding e.g. addresses in the IP header will not be aligned on a 32-bit boundary, so setting this to 2 can speed up 32-bit-platforms.

#define ETHARP_DEBUG   LWIP_DBG_OFF

ETHARP_DEBUG: Enable debugging in etharp.c.

#define ETHARP_STATS   (LWIP_ARP)

ETHARP_STATS==1: Enable etharp stats.

#define ETHARP_SUPPORT_STATIC_ENTRIES   0

ETHARP_SUPPORT_STATIC_ENTRIES==1: enable code to support static ARP table entries (using etharp_add_static_entry/etharp_remove_static_entry).

#define ETHARP_SUPPORT_VLAN   0

ETHARP_SUPPORT_VLAN==1: support receiving ethernet packets with VLAN header. Additionally, you can define ETHARP_VLAN_CHECK to an u16_t VLAN ID to check. If ETHARP_VLAN_CHECK is defined, only VLAN-traffic for this VLAN is accepted. If ETHARP_VLAN_CHECK is not defined, all traffic is accepted.

#define ETHARP_TRUST_IP_MAC   0

ETHARP_TRUST_IP_MAC==1: Incoming IP packets cause the ARP table to be updated with the source MAC and IP addresses supplied in the packet. You may want to disable this if you do not trust LAN peers to have the correct addresses, or as a limited approach to attempt to handle spoofing. If disabled, lwIP will need to make a new ARP request if the peer is not already in the ARP table, adding a little latency. The peer *is* in the ARP table if it requested our address before. Also notice that this slows down input processing of every IP packet!

#define ICMP_DEBUG   LWIP_DBG_OFF

ICMP_DEBUG: Enable debugging in icmp.c.

#define ICMP_STATS   1

ICMP_STATS==1: Enable ICMP stats.

#define ICMP_TTL   (IP_DEFAULT_TTL)

ICMP_TTL: Default value for Time-To-Live used by ICMP packets.

#define IGMP_DEBUG   LWIP_DBG_OFF

IGMP_DEBUG: Enable debugging in igmp.c.

#define IGMP_STATS   (LWIP_IGMP)

IGMP_STATS==1: Enable IGMP stats.

#define INET_DEBUG   LWIP_DBG_OFF

INET_DEBUG: Enable debugging in inet.c.

#define IP_DEBUG   LWIP_DBG_OFF

IP_DEBUG: Enable debugging for IP.

#define IP_DEFAULT_TTL   255

IP_DEFAULT_TTL: Default value for Time-To-Live used by transport layers.

#define IP_FORWARD   0

IP_FORWARD==1: Enables 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.

#define IP_FRAG   1

IP_FRAG==1: Fragment outgoing IP packets if their size exceeds MTU. Note that this option does not affect incoming packet sizes, which can be controlled via IP_REASSEMBLY.

#define IP_FRAG_USES_STATIC_BUF   0

IP_FRAG_USES_STATIC_BUF==1: Use a static MTU-sized buffer for IP fragmentation. Otherwise pbufs are allocated and reference the original packet data to be fragmented (or with LWIP_NETIF_TX_SINGLE_PBUF==1, new PBUF_RAM pbufs are used for fragments). ATTENTION: IP_FRAG_USES_STATIC_BUF==1 may not be used for DMA-enabled MACs!

#define IP_OPTIONS_ALLOWED   1

IP_OPTIONS_ALLOWED: Defines the behavior for IP options. IP_OPTIONS_ALLOWED==0: All packets with IP options are dropped. IP_OPTIONS_ALLOWED==1: IP options are allowed (but not parsed).

#define IP_REASS_DEBUG   LWIP_DBG_OFF

IP_REASS_DEBUG: Enable debugging in ip_frag.c for both frag & reass.

#define IP_REASS_MAX_PBUFS   10

IP_REASS_MAX_PBUFS: Total maximum amount of pbufs waiting to be reassembled. Since the received pbufs are enqueued, be sure to configure PBUF_POOL_SIZE > IP_REASS_MAX_PBUFS so that the stack is still able to receive packets even if the maximum amount of fragments is enqueued for reassembly!

#define IP_REASS_MAXAGE   3

IP_REASS_MAXAGE: Maximum time (in multiples of IP_TMR_INTERVAL - so seconds, normally) a fragmented IP packet waits for all fragments to arrive. If not all fragments arrived in this time, the whole packet is discarded.

#define IP_REASSEMBLY   1

IP_REASSEMBLY==1: Reassemble incoming fragmented IP packets. Note that this option does not affect outgoing packet sizes, which can be controlled via IP_FRAG.

#define IP_SOF_BROADCAST   0

IP_SOF_BROADCAST=1: Use the SOF_BROADCAST field to enable broadcast filter per pcb on udp and raw send operations. To enable broadcast filter on recv operations, you also have to set IP_SOF_BROADCAST_RECV=1.

#define IP_SOF_BROADCAST_RECV   0

IP_SOF_BROADCAST_RECV (requires IP_SOF_BROADCAST=1) enable the broadcast filter on recv operations.

#define IP_STATS   1

IP_STATS==1: Enable IP stats.

#define IPFRAG_STATS   (IP_REASSEMBLY || IP_FRAG)

IPFRAG_STATS==1: Enable IP fragmentation stats. Default is on if using either frag or reass.

#define LINK_STATS   1

LINK_STATS==1: Enable link stats.

#define LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT   0

Set this to 1 if you want to free PBUF_RAM pbufs (or call mem_free()) from interrupt context (or another context that doesn't allow waiting for a semaphore). If set to 1, mem_malloc will be protected by a semaphore and SYS_ARCH_PROTECT, while mem_free will only use SYS_ARCH_PROTECT. mem_malloc SYS_ARCH_UNPROTECTs with each loop so that mem_free can run. ATTENTION: As you can see from the above description, this leads to dis-/ enabling interrupts often, which can be slow! Also, on low memory, mem_malloc can need longer. If you don't want that, at least for NO_SYS=0, you can still use the following functions to enqueue a deallocation call which then runs in the tcpip_thread context: pbuf_free_callback(p); mem_free_callback(m);

#define LWIP_ARP   1

LWIP_ARP==1: Enable ARP functionality.

#define LWIP_AUTOIP   0

LWIP_AUTOIP==1: Enable AUTOIP module.

#define LWIP_BROADCAST_PING   0

LWIP_BROADCAST_PING==1: respond to broadcast pings (default is unicast only)

#define LWIP_CHECKSUM_ON_COPY   0

LWIP_CHECKSUM_ON_COPY==1: Calculate checksum when copying data from application buffers to pbufs.

#define LWIP_COMPAT_SOCKETS   1

LWIP_COMPAT_SOCKETS==1: Enable BSD-style sockets functions names. (only used if you use sockets.c)

#define LWIP_DBG_MIN_LEVEL   LWIP_DBG_LEVEL_ALL

LWIP_DBG_MIN_LEVEL: After masking, the value of the debug is compared against this value. If it is smaller, then debugging messages are written.

#define LWIP_DBG_TYPES_ON   LWIP_DBG_ON

LWIP_DBG_TYPES_ON: A mask that can be used to globally enable/disable debug messages of certain types.

#define LWIP_DHCP   0

LWIP_DHCP==1: Enable DHCP module.

#define LWIP_DHCP_AUTOIP_COOP   0

LWIP_DHCP_AUTOIP_COOP==1: Allow DHCP and AUTOIP to be both enabled on the same interface at the same time.

#define LWIP_DHCP_AUTOIP_COOP_TRIES   9

LWIP_DHCP_AUTOIP_COOP_TRIES: Set to the number of DHCP DISCOVER probes that should be sent before falling back on AUTOIP. This can be set as low as 1 to get an AutoIP address very quickly, but you should be prepared to handle a changing IP address when DHCP overrides AutoIP.

#define LWIP_DNS   0

LWIP_DNS==1: Turn on DNS module. UDP must be available for DNS transport.

#define LWIP_ETHERNET   (LWIP_ARP || PPPOE_SUPPORT)

LWIP_ETHERNET==1: enable ethernet support for PPPoE even though ARP might be disabled

#define LWIP_EVENT_API   0

LWIP_EVENT_API and LWIP_CALLBACK_API: Only one of these should be set to 1. LWIP_EVENT_API==1: The user defines lwip_tcp_event() to receive all events (accept, sent, etc) that happen in the system. LWIP_CALLBACK_API==1: The PCB callback function is called directly for the event.

#define LWIP_HAVE_LOOPIF   0

LWIP_HAVE_LOOPIF==1: Support loop interface (127.0.0.1) and loopif.c

#define LWIP_HAVE_SLIPIF   0

LWIP_HAVE_SLIPIF==1: Support slip interface and slipif.c

#define LWIP_ICMP   1

LWIP_ICMP==1: Enable ICMP module inside the IP stack. Be careful, disable that make your product non-compliant to RFC1122

#define LWIP_IGMP   0

LWIP_IGMP==1: Turn on IGMP module.

#define LWIP_LOOPBACK_MAX_PBUFS   0

LWIP_LOOPBACK_MAX_PBUFS: Maximum number of pbufs on queue for loopback sending for each netif (0 = disabled)

#define LWIP_MULTICAST_PING   0

LWIP_MULTICAST_PING==1: respond to multicast pings (default is unicast only)

#define LWIP_NETBUF_RECVINFO   0

LWIP_NETBUF_RECVINFO==1: append destination addr and port to every netbuf.

#define LWIP_NETCONN   1

LWIP_NETCONN==1: Enable Netconn API (require to use api_lib.c)

#define LWIP_NETIF_API   0

LWIP_NETIF_API==1: Support netif api (in netifapi.c)

#define LWIP_NETIF_HOSTNAME   0

LWIP_NETIF_HOSTNAME==1: use DHCP_OPTION_HOSTNAME with netif's hostname field.

#define LWIP_NETIF_HWADDRHINT   0

LWIP_NETIF_HWADDRHINT==1: Cache link-layer-address hints (e.g. table indices) in struct netif. TCP and UDP can make use of this to prevent scanning the ARP table for every sent packet. While this is faster for big ARP tables or many concurrent connections, it might be counterproductive if you have a tiny ARP table or if there never are concurrent connections.

#define LWIP_NETIF_LINK_CALLBACK   0

LWIP_NETIF_LINK_CALLBACK==1: Support a callback function from an interface whenever the link changes (i.e., link down)

#define LWIP_NETIF_LOOPBACK   0

LWIP_NETIF_LOOPBACK==1: Support sending packets with a destination IP address equal to the netif IP address, looping them back up the stack.

#define LWIP_NETIF_LOOPBACK_MULTITHREADING   (!NO_SYS)

LWIP_NETIF_LOOPBACK_MULTITHREADING: Indicates whether threading is enabled in the system, as netifs must change how they behave depending on this setting for the LWIP_NETIF_LOOPBACK option to work. Setting this is needed to avoid reentering non-reentrant functions like tcp_input(). LWIP_NETIF_LOOPBACK_MULTITHREADING==1: Indicates that the user is using a multithreaded environment like tcpip.c. In this case, netif->input() is called directly. LWIP_NETIF_LOOPBACK_MULTITHREADING==0: Indicates a polling (or NO_SYS) setup. The packets are put on a list and netif_poll() must be called in the main application loop.

#define LWIP_NETIF_STATUS_CALLBACK   0

LWIP_NETIF_STATUS_CALLBACK==1: Support a callback function whenever an interface changes its up/down status (i.e., due to DHCP IP acquistion)

#define LWIP_NETIF_TX_SINGLE_PBUF   0

LWIP_NETIF_TX_SINGLE_PBUF: if this is set to 1, lwIP tries to put all data to be sent into one single pbuf. This is for compatibility with DMA-enabled MACs that do not support scatter-gather. Beware that this might involve CPU-memcpy before transmitting that would not be needed without this flag! Use this only if you need to! Todo: : TCP and IP-frag do not work with this, yet:

#define LWIP_POSIX_SOCKETS_IO_NAMES   1

LWIP_POSIX_SOCKETS_IO_NAMES==1: Enable POSIX-style sockets functions names. Disable this option if you use a POSIX operating system that uses the same names (read, write & close). (only used if you use sockets.c)

#define LWIP_RAW   1

LWIP_RAW==1: Enable application layer to hook into the IP layer itself.

#define LWIP_SNMP   0

LWIP_SNMP==1: Turn on SNMP module. UDP must be available for SNMP transport.

#define LWIP_SO_RCVBUF   0

LWIP_SO_RCVBUF==1: Enable SO_RCVBUF processing.

#define LWIP_SO_RCVTIMEO   0

LWIP_SO_RCVTIMEO==1: Enable SO_RCVTIMEO processing.

#define LWIP_SOCKET   1

LWIP_SOCKET==1: Enable Socket API (require to use sockets.c)

#define LWIP_STATS   1

LWIP_STATS==1: Enable statistics collection in lwip_stats.

#define LWIP_STATS_DISPLAY   0

LWIP_STATS_DISPLAY==1: Compile in the statistics output functions.

#define LWIP_TCP   1

LWIP_TCP==1: Turn on TCP.

#define LWIP_TCP_KEEPALIVE   0

LWIP_TCP_KEEPALIVE==1: Enable TCP_KEEPIDLE, TCP_KEEPINTVL and TCP_KEEPCNT options processing. Note that TCP_KEEPIDLE and TCP_KEEPINTVL have to be set in seconds. (does not require sockets.c, and will affect tcp.c)

#define LWIP_TCP_TIMESTAMPS   0

LWIP_TCP_TIMESTAMPS==1: support the TCP timestamp option.

#define LWIP_TCPIP_CORE_LOCKING   0

LWIP_TCPIP_CORE_LOCKING: (EXPERIMENTAL!) Don't use it if you're not an active lwIP project member

#define LWIP_TCPIP_CORE_LOCKING_INPUT   0

LWIP_TCPIP_CORE_LOCKING_INPUT: (EXPERIMENTAL!) Don't use it if you're not an active lwIP project member

#define LWIP_TCPIP_TIMEOUT   1

LWIP_TCPIP_TIMEOUT==1: Enable tcpip_timeout/tcpip_untimeout tod create timers running in tcpip_thread from another thread.

#define LWIP_UDP   1

LWIP_UDP==1: Turn on UDP.

#define LWIP_UDPLITE   0

LWIP_UDPLITE==1: Turn on UDP-Lite. (Requires LWIP_UDP)

#define MEM_ALIGNMENT   1

MEM_ALIGNMENT: should be set to the alignment of the CPU 4 byte alignment -> define MEM_ALIGNMENT 4 2 byte alignment -> define MEM_ALIGNMENT 2

#define MEM_DEBUG   LWIP_DBG_OFF

MEM_DEBUG: Enable debugging in mem.c.

#define MEM_LIBC_MALLOC   0

MEM_LIBC_MALLOC==1: Use malloc/free/realloc provided by your C-library instead of the lwip internal allocator. Can save code size if you already use it.

#define MEM_SIZE   1600

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.

#define MEM_STATS   ((MEM_LIBC_MALLOC == 0) && (MEM_USE_POOLS == 0))

MEM_STATS==1: Enable mem.c stats.

#define MEM_USE_POOLS   0

MEM_USE_POOLS==1: Use an alternative to malloc() by allocating from a set of memory pools of various sizes. When mem_malloc is called, an element of the smallest pool that can provide the length needed is returned. To use this, MEMP_USE_CUSTOM_POOLS also has to be enabled.

#define MEM_USE_POOLS_TRY_BIGGER_POOL   0

MEM_USE_POOLS_TRY_BIGGER_POOL==1: if one malloc-pool is empty, try the next bigger pool - WARNING: THIS MIGHT WASTE MEMORY but it can make a system more reliable.

#define MEMCPY (  dst, src, len   )     memcpy(dst,src,len)

MEMCPY: override this if you have a faster implementation at hand than the one included in your C library

#define MEMP_DEBUG   LWIP_DBG_OFF

MEMP_DEBUG: Enable debugging in memp.c.

#define MEMP_MEM_MALLOC   0

MEMP_MEM_MALLOC==1: Use mem_malloc/mem_free instead of the lwip pool allocator. Especially useful with MEM_LIBC_MALLOC but handle with care regarding execution speed and usage from interrupts!

#define MEMP_NUM_ARP_QUEUE   30

MEMP_NUM_ARP_QUEUE: the number of simulateously queued outgoing packets (pbufs) that are waiting for an ARP request (to resolve their destination address) to finish. (requires the ARP_QUEUEING option)

#define MEMP_NUM_FRAG_PBUF   15

MEMP_NUM_FRAG_PBUF: the number of IP fragments simultaneously sent (fragments, not whole packets!). This is only used with IP_FRAG_USES_STATIC_BUF==0 and LWIP_NETIF_TX_SINGLE_PBUF==0 and only has to be > 1 with DMA-enabled MACs where the packet is not yet sent when netif->output returns.

#define MEMP_NUM_IGMP_GROUP   8

MEMP_NUM_IGMP_GROUP: The number of multicast groups whose network interfaces can be members et the same time (one per netif - allsystems group -, plus one per netif membership). (requires the LWIP_IGMP option)

#define MEMP_NUM_LOCALHOSTLIST   1

MEMP_NUM_LOCALHOSTLIST: the number of host entries in the local host list if DNS_LOCAL_HOSTLIST_IS_DYNAMIC==1.

#define MEMP_NUM_NETBUF   2

MEMP_NUM_NETBUF: the number of struct netbufs. (only needed if you use the sequential API, like api_lib.c)

#define MEMP_NUM_NETCONN   4

MEMP_NUM_NETCONN: the number of struct netconns. (only needed if you use the sequential API, like api_lib.c)

#define MEMP_NUM_NETDB   1

MEMP_NUM_NETDB: the number of concurrently running lwip_addrinfo() calls (before freeing the corresponding memory using lwip_freeaddrinfo()).

#define MEMP_NUM_PBUF   16

MEMP_NUM_PBUF: the number of memp struct pbufs (used for PBUF_ROM and PBUF_REF). If the application sends a lot of data out of ROM (or other static memory), this should be set high.

#define MEMP_NUM_PPPOE_INTERFACES   1

MEMP_NUM_PPPOE_INTERFACES: the number of concurrently active PPPoE interfaces (only used with PPPOE_SUPPORT==1)

#define MEMP_NUM_RAW_PCB   4

MEMP_NUM_RAW_PCB: Number of raw connection PCBs (requires the LWIP_RAW option)

#define MEMP_NUM_REASSDATA   5

MEMP_NUM_REASSDATA: the number of IP packets simultaneously queued for reassembly (whole packets, not fragments!)

#define MEMP_NUM_SNMP_NODE   50

MEMP_NUM_SNMP_NODE: the number of leafs in the SNMP tree.

#define MEMP_NUM_SNMP_ROOTNODE   30

MEMP_NUM_SNMP_ROOTNODE: the number of branches in the SNMP tree. Every branch has one leaf (MEMP_NUM_SNMP_NODE) at least!

#define MEMP_NUM_SNMP_VALUE   3

MEMP_NUM_SNMP_VALUE: the number of OID or values concurrently used (does not have to be changed normally) - 3 of these are used per request (1 for the value read and 2 for OIDs - input and output)

#define MEMP_NUM_SNMP_VARBIND   2

MEMP_NUM_SNMP_VARBIND: the number of concurrent requests (does not have to be changed normally) - 2 of these are used per request (1 for input, 1 for output)

#define MEMP_NUM_SYS_TIMEOUT   3

MEMP_NUM_SYS_TIMEOUT: the number of simulateously active timeouts. (requires NO_SYS==0)

#define MEMP_NUM_TCP_PCB   5

MEMP_NUM_TCP_PCB: the number of simulatenously active TCP connections. (requires the LWIP_TCP option)

#define MEMP_NUM_TCP_PCB_LISTEN   8

MEMP_NUM_TCP_PCB_LISTEN: the number of listening TCP connections. (requires the LWIP_TCP option)

#define MEMP_NUM_TCP_SEG   16

MEMP_NUM_TCP_SEG: the number of simultaneously queued TCP segments. (requires the LWIP_TCP option)

#define MEMP_NUM_TCPIP_MSG_API   8

MEMP_NUM_TCPIP_MSG_API: the number of struct tcpip_msg, which are used for callback/timeout API communication. (only needed if you use tcpip.c)

#define MEMP_NUM_TCPIP_MSG_INPKT   8

MEMP_NUM_TCPIP_MSG_INPKT: the number of struct tcpip_msg, which are used for incoming packets. (only needed if you use tcpip.c)

#define MEMP_NUM_UDP_PCB   4

MEMP_NUM_UDP_PCB: the number of UDP protocol control blocks. One per active UDP "connection". (requires the LWIP_UDP option)

#define MEMP_OVERFLOW_CHECK   0

MEMP_OVERFLOW_CHECK: memp overflow protection reserves a configurable amount of bytes before and after each memp element in every pool and fills it with a prominent default value. MEMP_OVERFLOW_CHECK == 0 no checking MEMP_OVERFLOW_CHECK == 1 checks each element when it is freed MEMP_OVERFLOW_CHECK >= 2 checks each element in every pool every time memp_malloc() or memp_free() is called (useful but slow!)

#define MEMP_SANITY_CHECK   0

MEMP_SANITY_CHECK==1: run a sanity check after each memp_free() to make sure that there are no cycles in the linked lists.

#define MEMP_SEPARATE_POOLS   0

MEMP_SEPARATE_POOLS: if defined to 1, each pool is placed in its own array. This can be used to individually change the location of each pool. Default is one big array for all pools

#define MEMP_STATS   (MEMP_MEM_MALLOC == 0)

MEMP_STATS==1: Enable memp.c pool stats.

#define MEMP_USE_CUSTOM_POOLS   0

MEMP_USE_CUSTOM_POOLS==1: whether to include a user file lwippools.h that defines additional pools beyond the "standard" ones required by lwIP. If you set this to 1, you must have lwippools.h in your inlude path somewhere.

#define NETIF_DEBUG   LWIP_DBG_OFF

NETIF_DEBUG: Enable debugging in netif.c.

#define NO_SYS   0

NO_SYS==1: Provides VERY minimal functionality. Otherwise, use lwIP facilities.

#define NO_SYS_NO_TIMERS   0

NO_SYS_NO_TIMERS==1: Drop support for sys_timeout when NO_SYS==1 Mainly for compatibility to old versions.

#define PBUF_DEBUG   LWIP_DBG_OFF

PBUF_DEBUG: Enable debugging in pbuf.c.

#define PBUF_LINK_HLEN   (14 + ETH_PAD_SIZE)

PBUF_LINK_HLEN: the number of bytes that should be allocated for a link level header. The default is 14, the standard value for Ethernet.

#define PBUF_POOL_BUFSIZE   LWIP_MEM_ALIGN_SIZE(TCP_MSS+40+PBUF_LINK_HLEN)

PBUF_POOL_BUFSIZE: the size of each pbuf in the pbuf pool. The default is designed to accomodate single full size TCP frame in one pbuf, including TCP_MSS, IP header, and link header.

#define PBUF_POOL_SIZE   16

PBUF_POOL_SIZE: the number of buffers in the pbuf pool.

#define PPP_DEBUG   LWIP_DBG_OFF

PPP_DEBUG: Enable debugging for PPP.

#define PPP_SUPPORT   0

PPP_SUPPORT==1: Enable PPP.

#define PPP_THREAD_NAME   "pppInputThread"

PPP_THREAD_NAME: The name assigned to the pppInputThread.

#define PPP_THREAD_PRIO   1

PPP_THREAD_PRIO: The priority assigned to the pppInputThread. The priority value itself is platform-dependent, but is passed to sys_thread_new() when the thread is created.

#define PPP_THREAD_STACKSIZE   0

PPP_THREAD_STACKSIZE: The stack size used by the pppInputThread. The stack size value itself is platform-dependent, but is passed to sys_thread_new() when the thread is created.

#define PPPOE_SUPPORT   0

PPPOE_SUPPORT==1: Enable PPP Over Ethernet

#define PPPOS_SUPPORT   PPP_SUPPORT

PPPOS_SUPPORT==1: Enable PPP Over Serial

#define RAW_DEBUG   LWIP_DBG_OFF

RAW_DEBUG: Enable debugging in raw.c.

#define RAW_TTL   (IP_DEFAULT_TTL)

LWIP_RAW==1: Enable application layer to hook into the IP layer itself.

#define RECV_BUFSIZE_DEFAULT   INT_MAX

If LWIP_SO_RCVBUF is used, this is the default value for recv_bufsize.

#define SLIP_DEBUG   LWIP_DBG_OFF

SLIP_DEBUG: Enable debugging in slipif.c.

#define SLIPIF_THREAD_NAME   "slipif_loop"

SLIPIF_THREAD_NAME: The name assigned to the slipif_loop thread.

#define SLIPIF_THREAD_PRIO   1

SLIPIF_THREAD_PRIO: The priority assigned to the slipif_loop thread. The priority value itself is platform-dependent, but is passed to sys_thread_new() when the thread is created.

#define SLIPIF_THREAD_STACKSIZE   0

SLIP_THREAD_STACKSIZE: The stack size used by the slipif_loop thread. The stack size value itself is platform-dependent, but is passed to sys_thread_new() when the thread is created.

#define SMEMCPY (  dst, src, len   )     memcpy(dst,src,len)

SMEMCPY: override this with care! Some compilers (e.g. gcc) can inline a call to memcpy() if the length is known at compile time and is small.

#define SNMP_CONCURRENT_REQUESTS   1

SNMP_CONCURRENT_REQUESTS: Number of concurrent requests the module will allow. At least one request buffer is required. Does not have to be changed unless external MIBs answer request asynchronously

#define SNMP_MAX_OCTET_STRING_LEN   127

The maximum length of strings used. This affects the size of MEMP_SNMP_VALUE elements.

#define SNMP_MAX_TREE_DEPTH   15

The maximum depth of the SNMP tree. With private MIBs enabled, this depends on your MIB! This affects the size of MEMP_SNMP_VALUE elements.

#define SNMP_MAX_VALUE_SIZE   LWIP_MAX((SNMP_MAX_OCTET_STRING_LEN)+1, sizeof(s32_t)*(SNMP_MAX_TREE_DEPTH))

The size of the MEMP_SNMP_VALUE elements, normally calculated from SNMP_MAX_OCTET_STRING_LEN and SNMP_MAX_TREE_DEPTH.

#define SNMP_MIB_DEBUG   LWIP_DBG_OFF

SNMP_MIB_DEBUG: Enable debugging for SNMP MIBs.

#define SNMP_MSG_DEBUG   LWIP_DBG_OFF

SNMP_MSG_DEBUG: Enable debugging for SNMP messages.

#define SNMP_PRIVATE_MIB   0

SNMP_PRIVATE_MIB: When using a private MIB, you have to create a file 'private_mib.h' that contains a 'struct mib_array_node mib_private' which contains your MIB.

#define SNMP_SAFE_REQUESTS   1

Only allow SNMP write actions that are 'safe' (e.g. disabeling netifs is not a safe action and disabled when SNMP_SAFE_REQUESTS = 1). Unsafe requests are disabled by default!

#define SNMP_TRAP_DESTINATIONS   1

SNMP_TRAP_DESTINATIONS: Number of trap destinations. At least one trap destination is required

#define SO_REUSE   0

SO_REUSE==1: Enable SO_REUSEADDR option.

#define SO_REUSE_RXTOALL   0

SO_REUSE_RXTOALL==1: Pass a copy of incoming broadcast/multicast packets to all local matches if SO_REUSEADDR is turned on. WARNING: Adds a memcpy for every packet if passing to more than one pcb!

#define SOCKETS_DEBUG   LWIP_DBG_OFF

SOCKETS_DEBUG: Enable debugging in sockets.c.

#define SYS_DEBUG   LWIP_DBG_OFF

SYS_DEBUG: Enable debugging in sys.c.

#define SYS_LIGHTWEIGHT_PROT   0

SYS_LIGHTWEIGHT_PROT==1: if you want inter-task protection for certain critical regions during buffer allocation, deallocation and memory allocation and deallocation.

#define SYS_STATS   (NO_SYS == 0)

SYS_STATS==1: Enable system stats (sem and mbox counts, etc).

#define TCP_CALCULATE_EFF_SEND_MSS   1

TCP_CALCULATE_EFF_SEND_MSS: "The maximum size of a segment that TCP really sends, the 'effective send MSS,' MUST be the smaller of the send MSS (which reflects the available reassembly buffer size at the remote host) and the largest size permitted by the IP layer" (RFC 1122) Setting this to 1 enables code that checks TCP_MSS against the MTU of the netif used for a connection and limits the MSS if it would be too big otherwise.

#define TCP_CWND_DEBUG   LWIP_DBG_OFF

TCP_CWND_DEBUG: Enable debugging for TCP congestion window.

#define TCP_DEBUG   LWIP_DBG_OFF

TCP_DEBUG: Enable debugging for TCP.

#define TCP_DEFAULT_LISTEN_BACKLOG   0xff

The maximum allowed backlog for TCP listen netconns. This backlog is used unless another is explicitly specified. 0xff is the maximum (u8_t).

#define TCP_FR_DEBUG   LWIP_DBG_OFF

TCP_FR_DEBUG: Enable debugging in tcp_in.c for fast retransmit.

#define TCP_INPUT_DEBUG   LWIP_DBG_OFF

TCP_INPUT_DEBUG: Enable debugging in tcp_in.c for incoming debug.

#define TCP_LISTEN_BACKLOG   0

TCP_LISTEN_BACKLOG: Enable the backlog option for tcp listen pcb.

#define TCP_MAXRTX   12

TCP_MAXRTX: Maximum number of retransmissions of data segments.

#define TCP_MSS   536

TCP_MSS: TCP Maximum segment size. (default is 536, a conservative default, you might want to increase this.) For the receive side, this MSS is advertised to the remote side when opening a connection. For the transmit size, this MSS sets an upper limit on the MSS advertised by the remote host.

#define TCP_OUTPUT_DEBUG   LWIP_DBG_OFF

TCP_OUTPUT_DEBUG: Enable debugging in tcp_out.c output functions.

#define TCP_OVERSIZE   TCP_MSS

TCP_OVERSIZE: The maximum number of bytes that tcp_write may allocate ahead of time in an attempt to create shorter pbuf chains for transmission. The meaningful range is 0 to TCP_MSS. Some suggested values are: 0: Disable oversized allocation. Each tcp_write() allocates a new pbuf (old behaviour). 1: Allocate size-aligned pbufs with minimal excess. Use this if your scatter-gather DMA requires aligned fragments. 128: Limit the pbuf/memory overhead to 20%. TCP_MSS: Try to create unfragmented TCP packets. TCP_MSS/4: Try to create 4 fragments or less per TCP packet.

#define TCP_QLEN_DEBUG   LWIP_DBG_OFF

TCP_QLEN_DEBUG: Enable debugging for TCP queue lengths.

#define TCP_QUEUE_OOSEQ   (LWIP_TCP)

TCP_QUEUE_OOSEQ==1: TCP will queue segments that arrive out of order. Define to 0 if your device is low on memory.

#define TCP_RST_DEBUG   LWIP_DBG_OFF

TCP_RST_DEBUG: Enable debugging for TCP with the RST message.

#define TCP_RTO_DEBUG   LWIP_DBG_OFF

TCP_RTO_DEBUG: Enable debugging in TCP for retransmit timeout.

#define TCP_SND_BUF   256

TCP_SND_BUF: TCP sender buffer space (bytes).

#define TCP_SND_QUEUELEN   ((4 * (TCP_SND_BUF) + (TCP_MSS - 1))/(TCP_MSS))

TCP_SND_QUEUELEN: TCP sender buffer space (pbufs). This must be at least as much as (2 * TCP_SND_BUF/TCP_MSS) for things to work.

#define TCP_SNDLOWAT   ((TCP_SND_BUF)/2)

TCP_SNDLOWAT: TCP writable space (bytes). This must be less than TCP_SND_BUF. It is the amount of space which must be available in the TCP snd_buf for select to return writable (combined with TCP_SNDQUEUELOWAT).

#define TCP_SNDQUEUELOWAT   ((TCP_SND_QUEUELEN)/2)

TCP_SNDQUEUELOWAT: TCP writable bufs (pbuf count). This must be grater than TCP_SND_QUEUELEN. If the number of pbufs queued on a pcb drops below this number, select returns writable (combined with TCP_SNDLOWAT).

#define TCP_STATS   (LWIP_TCP)

TCP_STATS==1: Enable TCP stats. Default is on if TCP enabled, otherwise off.

#define TCP_SYNMAXRTX   6

TCP_SYNMAXRTX: Maximum number of retransmissions of SYN segments.

#define TCP_TTL   (IP_DEFAULT_TTL)

TCP_TTL: Default Time-To-Live value.

#define TCP_WND   (4 * TCP_MSS)

TCP_WND: The size of a TCP window. This must be at least (2 * TCP_MSS) for things to work well

#define TCP_WND_DEBUG   LWIP_DBG_OFF

TCP_WND_DEBUG: Enable debugging in tcp_in.c for window updating.

#define TCP_WND_UPDATE_THRESHOLD   (TCP_WND / 4)

TCP_WND_UPDATE_THRESHOLD: difference in window to trigger an explicit window update

#define TCPIP_DEBUG   LWIP_DBG_OFF

TCPIP_DEBUG: Enable debugging in tcpip.c.

#define TCPIP_MBOX_SIZE   0

TCPIP_MBOX_SIZE: The mailbox size for the tcpip thread messages The queue size value itself is platform-dependent, but is passed to sys_mbox_new() when tcpip_init is called.

#define TCPIP_THREAD_NAME   "tcpip_thread"

TCPIP_THREAD_NAME: The name assigned to the main tcpip thread.

#define TCPIP_THREAD_PRIO   1

TCPIP_THREAD_PRIO: The priority assigned to the main tcpip thread. The priority value itself is platform-dependent, but is passed to sys_thread_new() when the thread is created.

#define TCPIP_THREAD_STACKSIZE   0

TCPIP_THREAD_STACKSIZE: The stack size used by the main tcpip thread. The stack size value itself is platform-dependent, but is passed to sys_thread_new() when the thread is created.

#define TIMERS_DEBUG   LWIP_DBG_OFF

TIMERS_DEBUG: Enable debugging in timers.c.

#define UDP_DEBUG   LWIP_DBG_OFF

UDP_DEBUG: Enable debugging in UDP.

#define UDP_STATS   (LWIP_UDP)

UDP_STATS==1: Enable UDP stats. Default is on if UDP enabled, otherwise off.

#define UDP_TTL   (IP_DEFAULT_TTL)

UDP_TTL: Default Time-To-Live value.

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