#include <netinet/tcp.h>

netinet/tcp.h

includes: sys/appleapiopts.h, sys/socket.h, sys/types.h, machine/endian.h, machine/types.h, netinet/in.h, sys/types.h

81 macros · 2 typedefs · 2 structs

typedeftcp_seq

typedef __uint32_t tcp_seq

typedeftcp_cc

typedef __uint32_t tcp_cc

connection count per rfc1644

structtcphdr

TCP header. Per RFC 793, September, 1981.

size 20, align 4

unsigned short	th_sport	source port
unsigned short	th_dport	destination port
tcp_seq	th_seq	sequence number
tcp_seq	th_ack	acknowledgement number
unsigned int:4	th_x2	(unused)
unsigned int:4	th_off	data offset
unsigned char	th_flags
unsigned short	th_win	window
unsigned short	th_sum	checksum
unsigned short	th_urp	urgent pointer

macroTH_FIN

#define TH_FIN 0x01

macroTH_SYN

#define TH_SYN 0x02

macroTH_RST

#define TH_RST 0x04

macroTH_PUSH

#define TH_PUSH 0x08

macroTH_ACK

#define TH_ACK 0x10

macroTH_URG

#define TH_URG 0x20

macroTH_ECE

#define TH_ECE 0x40

macroTH_CWR

#define TH_CWR 0x80

macroTH_FLAGS

#define TH_FLAGS (TH_FIN|TH_SYN|TH_RST|TH_ACK|TH_URG|TH_ECE|TH_CWR)

macroTH_FLAGS_ALL

#define TH_FLAGS_ALL (TH_FLAGS|TH_PUSH)

macroTH_ACCEPT

#define TH_ACCEPT (TH_FIN|TH_SYN|TH_RST|TH_ACK)

macroTH_ACE

#define TH_ACE (TH_AE|TH_CWR|TH_ECE)

macroTCPOPT_EOL

#define TCPOPT_EOL 0

macroTCPOLEN_EOL

#define TCPOLEN_EOL 1

macroTCPOPT_NOP

#define TCPOPT_NOP 1

macroTCPOLEN_NOP

#define TCPOLEN_NOP 1

macroTCPOPT_MAXSEG

#define TCPOPT_MAXSEG 2

macroTCPOLEN_MAXSEG

#define TCPOLEN_MAXSEG 4

macroTCPOPT_WINDOW

#define TCPOPT_WINDOW 3

macroTCPOLEN_WINDOW

#define TCPOLEN_WINDOW 3

macroTCPOLEN_SACK_PERMITTED

#define TCPOLEN_SACK_PERMITTED 2

macroTCPOPT_SACK

#define TCPOPT_SACK 5

macroTCPOLEN_SACKHDR

#define TCPOLEN_SACKHDR 2

macroTCPOPT_TIMESTAMP

#define TCPOPT_TIMESTAMP 8

macroTCPOLEN_TIMESTAMP

#define TCPOLEN_TIMESTAMP 10

macroTCPOPT_TSTAMP_HDR

#define TCPOPT_TSTAMP_HDR (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_TIMESTAMP<<8|TCPOLEN_TIMESTAMP)

macroTCPOPT_CCNEW

#define TCPOPT_CCNEW 12

macroTCPOPT_CCECHO

#define TCPOPT_CCECHO 13

macroTCPOLEN_CC

#define TCPOLEN_CC 6

macroTCPOLEN_CC_APPA

#define TCPOLEN_CC_APPA (TCPOLEN_CC+2)

macroTCPOPT_CC_HDR

#define TCPOPT_CC_HDR(ccopt) (TCPOPT_NOP<<24|TCPOPT_NOP<<16|(ccopt)<<8|TCPOLEN_CC)

macroTCPOLEN_SIGNATURE

#define TCPOLEN_SIGNATURE 18

macroTCPOPT_FASTOPEN

#define TCPOPT_FASTOPEN 34

macroTCPOLEN_FASTOPEN_REQ

#define TCPOLEN_FASTOPEN_REQ 2

macroTCPOPT_SACK_PERMIT_HDR

Option definitions

#define TCPOPT_SACK_PERMIT_HDR (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_SACK_PERMITTED<<8|TCPOLEN_SACK_PERMITTED)

macroTCPOPT_SACK_HDR

#define TCPOPT_SACK_HDR (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_SACK<<8)

macroTCP_MSS

Default maximum segment size for TCP. With an IP MTU of 576, this is 536, but 512 is probably more convenient. This should be defined as MIN(512, IP_MSS - sizeof (struct tcpiphdr)).

#define TCP_MSS 512

TCP_MINMSS is defined to be 216 which is fine for the smallest link MTU (256 bytes, SLIP interface) in the Internet. However it is very unlikely to come across such low MTU interfaces these days (anno dato 2004). Probably it can be set to 512 without ill effects. But we play safe. See tcp_subr.c tcp_minmss SYSCTL declaration for more comments. Setting this to "0" disables the minmss check.

#define TCP_MINMSS 216

macroTCP6_MSS

Default maximum segment size for TCP6. With an IP6 MSS of 1280, this is 1220, but 1024 is probably more convenient. (xxx kazu in doubt) This should be defined as MIN(1024, IP6_MSS - sizeof (struct tcpip6hdr))

#define TCP6_MSS 1024

macroTCP_MAXWIN

#define TCP_MAXWIN 65535

largest value for (unscaled) window

macroTTCP_CLIENT_SND_WND

#define TTCP_CLIENT_SND_WND 4096

dflt send window for T/TCP client

macroTCP_MAX_WINSHIFT

#define TCP_MAX_WINSHIFT 14

maximum window shift

macroTCP_MAXHLEN

#define TCP_MAXHLEN (0xf<<2)

max length of header in bytes

macroTCP_MAXOLEN

#define TCP_MAXOLEN (TCP_MAXHLEN - sizeof(struct tcphdr))

macroTCP_NODELAY

User-settable options (used with setsockopt).

#define TCP_NODELAY 0x01

don't delay send to coalesce packets

macroTCP_MAXSEG

#define TCP_MAXSEG 0x02

set maximum segment size

macroTCP_NOPUSH

#define TCP_NOPUSH 0x04

don't push last block of write

macroTCP_NOOPT

#define TCP_NOOPT 0x08

don't use TCP options

macroTCP_KEEPALIVE

#define TCP_KEEPALIVE 0x10

idle time used when SO_KEEPALIVE is enabled

macroTCP_CONNECTIONTIMEOUT

#define TCP_CONNECTIONTIMEOUT 0x20

connection timeout

macroPERSIST_TIMEOUT

#define PERSIST_TIMEOUT 0x40

time after which a connection in persist timeout will terminate. see draft-ananth-tcpm-persist-02.txt

macroTCP_RXT_CONNDROPTIME

#define TCP_RXT_CONNDROPTIME 0x80

time after which tcp retransmissions will be stopped and the connection will be dropped

macroTCP_RXT_FINDROP

#define TCP_RXT_FINDROP 0x100

when this option is set, drop a connection after retransmitting the FIN 3 times. It will prevent holding too many mbufs in socket buffer queues.

macroTCP_KEEPINTVL

#define TCP_KEEPINTVL 0x101

interval between keepalives

macroTCP_KEEPCNT

#define TCP_KEEPCNT 0x102

number of keepalives before close

macroTCP_SENDMOREACKS

#define TCP_SENDMOREACKS 0x103

always ack every other packet

macroTCP_ENABLE_ECN

#define TCP_ENABLE_ECN 0x104

Enable ECN on a connection

macroTCP_FASTOPEN

#define TCP_FASTOPEN 0x105

Enable/Disable TCP Fastopen on this socket

macroTCP_CONNECTION_INFO

#define TCP_CONNECTION_INFO 0x106

State of TCP connection

macroTCP_NOTSENT_LOWAT

#define TCP_NOTSENT_LOWAT 0x201

Low water mark for TCP unsent data

structtcp_connection_info

size 112, align 8

u_int8_t	tcpi_state	connection state
u_int8_t	tcpi_snd_wscale	Window scale for send window
u_int8_t	tcpi_rcv_wscale	Window scale for receive window
u_int8_t	__pad1
u_int32_t	tcpi_options	TCP options supported
u_int32_t	tcpi_flags	flags
u_int32_t	tcpi_rto	retransmit timeout in ms
u_int32_t	tcpi_maxseg	maximum segment size supported
u_int32_t	tcpi_snd_ssthresh	slow start threshold in bytes
u_int32_t	tcpi_snd_cwnd	send congestion window in bytes
u_int32_t	tcpi_snd_wnd	send widnow in bytes
u_int32_t	tcpi_snd_sbbytes	bytes in send socket buffer, including in-flight data
u_int32_t	tcpi_rcv_wnd	receive window in bytes
u_int32_t	tcpi_rttcur	most recent RTT in ms
u_int32_t	tcpi_srtt	average RTT in ms
u_int32_t	tcpi_rttvar	RTT variance
u_int32_t:1	tcpi_tfo_cookie_req	Cookie requested?
u_int32_t:1	tcpi_tfo_cookie_rcv	Cookie received?
u_int32_t:1	tcpi_tfo_syn_loss	Fallback to reg. TCP after SYN-loss
u_int32_t:1	tcpi_tfo_syn_data_sent	SYN+data has been sent out
u_int32_t:1	tcpi_tfo_syn_data_acked	SYN+data has been fully acknowledged
u_int32_t:1	tcpi_tfo_syn_data_rcv	Server received SYN+data with a valid cookie
u_int32_t:1	tcpi_tfo_cookie_req_rcv	Server received cookie-request
u_int32_t:1	tcpi_tfo_cookie_sent	Server announced cookie
u_int32_t:1	tcpi_tfo_cookie_invalid	Server received an invalid cookie
u_int32_t:1	tcpi_tfo_cookie_wrong	Our sent cookie was wrong
u_int32_t:1	tcpi_tfo_no_cookie_rcv	We did not receive a cookie upon our request
u_int32_t:1	tcpi_tfo_heuristics_disable	TFO-heuristics disabled it
u_int32_t:1	tcpi_tfo_send_blackhole	A sending-blackhole got detected
u_int32_t:1	tcpi_tfo_recv_blackhole	A receiver-blackhole got detected
u_int32_t:1	tcpi_tfo_onebyte_proxy	A proxy acknowledges all but one byte of the SYN
u_int32_t:17	__pad2
u_int64_t	tcpi_txpackets
u_int64_t	tcpi_txbytes
u_int64_t	tcpi_txretransmitbytes
u_int64_t	tcpi_rxpackets
u_int64_t	tcpi_rxbytes
u_int64_t	tcpi_rxoutoforderbytes
u_int64_t	tcpi_txretransmitpackets

macroTCPCI_OPT_TIMESTAMPS

#define TCPCI_OPT_TIMESTAMPS 0x00000001

Timestamps enabled

macroTCPCI_OPT_SACK

#define TCPCI_OPT_SACK 0x00000002

SACK enabled

macroTCPCI_OPT_WSCALE

#define TCPCI_OPT_WSCALE 0x00000004

Window scaling enabled

macroTCPCI_OPT_ECN

#define TCPCI_OPT_ECN 0x00000008

ECN enabled

macroTCPCI_FLAG_LOSSRECOVERY

#define TCPCI_FLAG_LOSSRECOVERY 0x00000001

macroTCPCI_FLAG_REORDERING_DETECTED

#define TCPCI_FLAG_REORDERING_DETECTED 0x00000002