OVMS3-idf/components/lwip/Kconfig
Angus Gratton 1c6510ed96 lwip: Allow configuring/disabling some TCP options to save RAM
RAM savings are small, but may add up when running large numbers of sockets.
2017-06-23 16:26:11 +10:00

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6.7 KiB
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menu "LWIP"
config L2_TO_L3_COPY
bool "Enable copy between Layer2 and Layer3 packets"
default n
help
If this feature is enabled, all traffic from layer2(WIFI Driver) will be
copied to a new buffer before sending it to layer3(LWIP stack), freeing
the layer2 buffer.
Please be notified that the total layer2 receiving buffer is fixed and
ESP32 currently supports 25 layer2 receiving buffer, when layer2 buffer
runs out of memory, then the incoming packets will be dropped in hardware.
The layer3 buffer is allocated from the heap, so the total layer3 receiving
buffer depends on the available heap size, when heap runs out of memory,
no copy will be sent to layer3 and packet will be dropped in layer2.
Please make sure you fully understand the impact of this feature before
enabling it.
config LWIP_MAX_SOCKETS
int "Max number of open sockets"
range 1 32
default 10
help
Sockets take up a certain amount of memory, and allowing fewer
sockets to be open at the same time conserves memory. Specify
the maximum amount of sockets here. The valid value is from 1
to 16.
config LWIP_THREAD_LOCAL_STORAGE_INDEX
int "Index for thread-local-storage pointer for lwip"
default 0
help
Specify the thread-local-storage-pointer index for lwip
use.
config LWIP_SO_REUSE
bool "Enable SO_REUSEADDR option"
default n
help
Enabling this option allows binding to a port which remains in
TIME_WAIT.
config LWIP_SO_RCVBUF
bool "Enable SO_RCVBUF option"
default n
help
Enabling this option allows checking for available data on a netconn.
config LWIP_DHCP_MAX_NTP_SERVERS
int "Maximum number of NTP servers"
default 1
range 1 16
help
Set maximum number of NTP servers used by LwIP SNTP module.
First argument of sntp_setserver/sntp_setservername functions
is limited to this value.
config LWIP_IP_FRAG
bool "Enable fragment outgoing IP packets"
default n
help
Enabling this option allows fragmenting outgoing IP packets if their size
exceeds MTU.
config LWIP_IP_REASSEMBLY
bool "Enable reassembly incoming fragmented IP packets"
default n
help
Enabling this option allows reassemblying incoming fragmented IP packets.
menu "TCP"
config TCP_MAXRTX
int "Maximum number of retransmissions of data segments"
default 12
range 3 12
help
Set maximum number of retransmissions of data segments.
config TCP_SYNMAXRTX
int "Maximum number of retransmissions of SYN segments"
default 6
range 3 12
help
Set maximum number of retransmissions of SYN segments.
config TCP_MSS
int "Maximum Segment Size (MSS)"
default 1436
range 1220 1436
help
Set maximum segment size for TCP transmission.
Can be set lower to save RAM, the default value 1436 will give best throughput.
config TCP_SND_BUF_DEFAULT
int "Default send buffer size"
default 5744 # 4 * default MSS
range 2440 65535
help
Set default send buffer size for new TCP sockets.
Per-socket send buffer size can be changed at runtime
with lwip_setsockopt(s, TCP_SNDBUF, ...).
This value must be at least 2x the MSS size, and the default
is 4x the default MSS size.
Setting a smaller default SNDBUF size can save some RAM, but
will decrease performance.
config TCP_WND_DEFAULT
int "Default receive window size"
default 5744 # 4 * default MSS
range 2440 65535
help
Set default TCP receive window size for new TCP sockets.
Per-socket receive window size can be changed at runtime
with lwip_setsockopt(s, TCP_WINDOW, ...).
Setting a smaller default receive window size can save some RAM,
but will significantly decrease performance.
config TCP_QUEUE_OOSEQ
bool "Queue incoming out-of-order segments"
default y
help
Queue incoming out-of-order segments for later use.
Disable this option to save some RAM during TCP sessions, at the expense
of increased retransmissions if segments arrive out of order.
choice TCP_OVERSIZE
prompt "Pre-allocate transmit PBUF size"
default TCP_OVERSIZE_MSS
help
Allows enabling "oversize" allocation of TCP transmission pbufs ahead of time,
which can reduce the length of pbuf chains used for transmission.
This will not make a difference to sockets where Nagle's algorithm
is disabled.
Default value of MSS is fine for most applications, 25% MSS may save
some RAM when only transmitting small amounts of data. Disabled will
have worst performance and fragmentation characteristics, but uses
least RAM overall.
config TCP_OVERSIZE_MSS
bool "MSS"
config TCP_OVERSIZE_QUARTER_MSS
bool "25% MSS"
config TCP_OVERSIZE_DISABLE
bool "Disabled"
endchoice
endmenu # TCP
config LWIP_DHCP_DOES_ARP_CHECK
bool "Enable an ARP check on the offered address"
default y
help
Enabling this option allows check if the offered IP address is not already
in use by another host on the network.
config TCPIP_TASK_STACK_SIZE
int "TCP/IP Task Stack Size"
default 2560
help
Configure TCP/IP task stack size, used by LWIP to process multi-threaded TCP/IP operations.
The default is 2560 bytes, setting this stack too small will result in stack overflow crashes.
menuconfig PPP_SUPPORT
bool "Enable PPP support (new/experimental)"
default n
help
Enable PPP stack. Now only PPP over serial is possible.
PPP over serial support is experimental and unsupported.
config PPP_PAP_SUPPORT
bool "Enable PAP support"
depends on PPP_SUPPORT
default n
help
Enable Password Authentication Protocol (PAP) support
config PPP_CHAP_SUPPORT
bool "Enable CHAP support"
depends on PPP_SUPPORT
default n
help
Enable Challenge Handshake Authentication Protocol (CHAP) support
config PPP_MSCHAP_SUPPORT
bool "Enable MSCHAP support"
depends on PPP_SUPPORT
default n
help
Enable Microsoft version of the Challenge-Handshake Authentication Protocol (MSCHAP) support
config PPP_MPPE_SUPPORT
bool "Enable MPPE support"
depends on PPP_SUPPORT
default n
help
Enable Microsoft Point-to-Point Encryption (MPPE) support
config PPP_DEBUG_ON
bool "Enable PPP debug log output"
depends on PPP_SUPPORT
default n
help
Enable PPP debug log output
menu "ICMP"
config LWIP_MULTICAST_PING
bool "Respond to multicast pings"
default n
config LWIP_BROADCAST_PING
bool "Respond to broadcast pings"
default n
endmenu # ICMP
endmenu