#include <netinet/tcp_var.h>
BSD / POSIX › Networking

netinet/tcp_var.h

includes: stdint.h, sys/types.h, sys/appleapiopts.h, sys/queue.h, netinet/in_pcb.h, netinet/tcp.h, netinet/tcp_timer.h, TargetConditionals.h
41 macros · 6 structs

macro_TCPCB_PTR

#define _TCPCB_PTR(x) u_int32_t

macro_TCPCB_LIST_HEAD

#define _TCPCB_LIST_HEAD(name, type) struct name {
	u_int32_t	lh_first;
}

structtsegqe_head

size 4, align 4
u_int32_tlh_first

structtcpcb

size 204, align 4
struct tsegqe_headt_segq
intt_dupacksconsecutive dup acks recd
u_int32_tunusedunused now: was t_template
int[4]t_timertcp timers
u_int32_tt_inpcbback pointer to internet pcb
intt_statestate of this connection
u_intt_flags
intt_force1 if forcing out a byte
tcp_seqsnd_unasend unacknowledged
tcp_seqsnd_maxhighest sequence number sent; used to recognize retransmits
tcp_seqsnd_nxtsend next
tcp_seqsnd_upsend urgent pointer
tcp_seqsnd_wl1window update seg seq number
tcp_seqsnd_wl2window update seg ack number
tcp_seqissinitial send sequence number
tcp_seqirsinitial receive sequence number
tcp_seqrcv_nxtreceive next
tcp_seqrcv_advadvertised window
u_int32_trcv_wndreceive window
tcp_seqrcv_upreceive urgent pointer
u_int32_tsnd_wndsend window
u_int32_tsnd_cwndcongestion-controlled window
u_int32_tsnd_ssthreshsnd_cwnd size threshold for for slow start exponential to linear switch
u_intt_maxopdmss plus options
u_int32_tt_rcvtimetime at which a packet was received
u_int32_tt_starttimetime connection was established
intt_rtttimeround trip time
tcp_seqt_rtseqsequence number being timed
intt_rxtcurcurrent retransmit value (ticks)
u_intt_maxsegmaximum segment size
intt_srttsmoothed round-trip time
intt_rttvarvariance in round-trip time
intt_rxtshiftlog(2) of rexmt exp. backoff
u_intt_rttminminimum rtt allowed
u_int32_tt_rttupdatednumber of times rtt sampled
u_int32_tmax_sndwndlargest window peer has offered
intt_softerrorpossible error not yet reported
chart_oobflagsout-of-band data have some
chart_iobcinput character
u_charsnd_scaleRFC 1323 variables window scaling for send window
u_charrcv_scalewindow scaling for recv window
u_charrequest_r_scalepending window scaling
u_charrequested_s_scale
u_int32_tts_recenttimestamp echo data
u_int32_tts_recent_agewhen last updated
tcp_seqlast_ack_sent
tcp_cccc_sendRFC 1644 variables send connection count
tcp_cccc_recvreceive connection count
tcp_seqsnd_recoverfor use in fast recovery
u_int32_tsnd_cwnd_prevexperimental cwnd prior to retransmit
u_int32_tsnd_ssthresh_prevssthresh prior to retransmit
u_int32_tt_badrxtwinwindow for retransmit recovery

macroTF_ACKNOW

#define TF_ACKNOW 0x00001
ack peer immediately

macroTF_DELACK

#define TF_DELACK 0x00002
ack, but try to delay it

macroTF_NODELAY

#define TF_NODELAY 0x00004
don't delay packets to coalesce

macroTF_NOOPT

#define TF_NOOPT 0x00008
don't use tcp options

macroTF_SENTFIN

#define TF_SENTFIN 0x00010
have sent FIN

macroTF_REQ_SCALE

#define TF_REQ_SCALE 0x00020
have/will request window scaling

macroTF_RCVD_SCALE

#define TF_RCVD_SCALE 0x00040
other side has requested scaling

macroTF_REQ_TSTMP

#define TF_REQ_TSTMP 0x00080
have/will request timestamps

macroTF_RCVD_TSTMP

#define TF_RCVD_TSTMP 0x00100
a timestamp was received in SYN

macroTF_SACK_PERMIT

#define TF_SACK_PERMIT 0x00200
other side said I could SACK

macroTF_NEEDSYN

#define TF_NEEDSYN 0x00400
send SYN (implicit state) - unused but needed for backwards compatibility

macroTF_NEEDFIN

#define TF_NEEDFIN 0x00800
send FIN (implicit state)

macroTF_NOPUSH

#define TF_NOPUSH 0x01000
don't push

macroTF_REQ_CC

#define TF_REQ_CC 0x02000
have/will request CC

macroTF_RCVD_CC

#define TF_RCVD_CC 0x04000
a CC was received in SYN

macroTF_SENDCCNEW

#define TF_SENDCCNEW 0x08000
Not implemented

macroTF_MORETOCOME

#define TF_MORETOCOME 0x10000
More data to be appended to sock

macroTF_LQ_OVERFLOW

#define TF_LQ_OVERFLOW 0x20000
listen queue overflow

macroTF_RXWIN0SENT

#define TF_RXWIN0SENT 0x40000
sent a receiver win 0 in response

macroTCPOOB_HAVEDATA

#define TCPOOB_HAVEDATA 0x01

macroTCPOOB_HADDATA

#define TCPOOB_HADDATA 0x02

macrotcps_ecn_setup

#define tcps_ecn_setup tcps_ecn_client_success

macrotcps_sent_cwr

#define tcps_sent_cwr tcps_ecn_recv_ece

macrotcps_sent_ece

#define tcps_sent_ece tcps_ecn_sent_ece

structtcpstat

TCP statistics. Many of these should be kept per connection, but that's inconvenient at the moment.
size 912, align 8
u_int32_ttcps_connattemptconnections initiated
u_int32_ttcps_acceptsconnections accepted
u_int32_ttcps_connectsconnections established
u_int32_ttcps_dropsconnections dropped
u_int32_ttcps_conndropsembryonic connections dropped
u_int32_ttcps_closedconn. closed (includes drops)
u_int32_ttcps_segstimedsegs where we tried to get rtt
u_int32_ttcps_rttupdatedtimes we succeeded
u_int32_ttcps_delackdelayed acks sent
u_int32_ttcps_timeoutdropconn. dropped in rxmt timeout
u_int32_ttcps_rexmttimeoretransmit timeouts
u_int32_ttcps_persisttimeopersist timeouts
u_int32_ttcps_keeptimeokeepalive timeouts
u_int32_ttcps_keepprobekeepalive probes sent
u_int32_ttcps_keepdropsconnections dropped in keepalive
u_int32_ttcps_sndtotaltotal packets sent
u_int32_ttcps_sndpackdata packets sent
u_int32_ttcps_sndbytedata bytes sent
u_int32_ttcps_sndrexmitpackdata packets retransmitted
u_int32_ttcps_sndrexmitbytedata bytes retransmitted
u_int32_ttcps_sndacksack-only packets sent
u_int32_ttcps_sndprobewindow probes sent
u_int32_ttcps_sndurgpackets sent with URG only
u_int32_ttcps_sndwinupwindow update-only packets sent
u_int32_ttcps_sndctrlcontrol (SYN|FIN|RST) packets sent
u_int32_ttcps_rcvtotaltotal packets received
u_int32_ttcps_rcvpackpackets received in sequence
u_int32_ttcps_rcvbytebytes received in sequence
u_int32_ttcps_rcvbadsumpackets received with ccksum errs
u_int32_ttcps_rcvbadoffpackets received with bad offset
u_int32_ttcps_rcvmemdroppackets dropped for lack of memory
u_int32_ttcps_rcvshortpackets received too short
u_int32_ttcps_rcvduppackduplicate-only packets received
u_int32_ttcps_rcvdupbyteduplicate-only bytes received
u_int32_ttcps_rcvpartduppackpackets with some duplicate data
u_int32_ttcps_rcvpartdupbytedup. bytes in part-dup. packets
u_int32_ttcps_rcvoopackout-of-order packets received
u_int32_ttcps_rcvoobyteout-of-order bytes received
u_int32_ttcps_rcvpackafterwinpackets with data after window
u_int32_ttcps_rcvbyteafterwinbytes rcvd after window
u_int32_ttcps_rcvafterclosepackets rcvd after "close"
u_int32_ttcps_rcvwinprobercvd window probe packets
u_int32_ttcps_rcvdupackrcvd duplicate acks
u_int32_ttcps_rcvacktoomuchrcvd acks for unsent data
u_int32_ttcps_rcvackpackrcvd ack packets
u_int32_ttcps_rcvackbytebytes acked by rcvd acks
u_int32_ttcps_rcvwinupdrcvd window update packets
u_int32_ttcps_pawsdropsegments dropped due to PAWS
u_int32_ttcps_predacktimes hdr predict ok for acks
u_int32_ttcps_preddattimes hdr predict ok for data pkts
u_int32_ttcps_cachedrtttimes cached RTT in route updated
u_int32_ttcps_cachedrttvartimes cached rttvar updated
u_int32_ttcps_cachedssthreshtimes cached ssthresh updated
u_int32_ttcps_usedrtttimes RTT initialized from route
u_int32_ttcps_usedrttvartimes RTTVAR initialized from rt
u_int32_ttcps_usedssthreshtimes ssthresh initialized from rt
u_int32_ttcps_persistdroptimeout in persist state
u_int32_ttcps_badsynbogus SYN, e.g. premature ACK
u_int32_ttcps_mturesentresends due to MTU discovery
u_int32_ttcps_listendroplisten queue overflows
u_int32_ttcps_synchallengechallenge ACK due to bad SYN
u_int32_ttcps_rstchallengechallenge ACK due to bad RST
u_int32_ttcps_minmssdropsnew stats from FreeBSD 5.4 sync up average minmss too low drops
u_int32_ttcps_sndrexmitbadunnecessary packet retransmissions
u_int32_ttcps_badrstignored RSTs in the window
u_int32_ttcps_sc_droppedcould not reply to packet
u_int32_ttcps_sc_completedsuccessful extraction of entry
u_int32_ttcps_sc_abortedsyncache entry aborted
u_int32_ttcps_sc_sendcookieSYN cookie sent
u_int32_ttcps_sc_recvcookieSYN cookie received
u_int32_ttcps_sack_recovery_episodeSACK related stats SACK recovery episodes
u_int32_ttcps_sack_rexmitsSACK rexmit segments
u_int32_ttcps_sack_rexmit_bytesSACK rexmit bytes
u_int32_ttcps_sack_rcv_blocksSACK blocks (options) received
u_int32_ttcps_sack_send_blocksSACK blocks (options) sent
u_int32_ttcps_sack_sboverflowSACK sendblock overflow
u_int32_ttcps_rack_recovery_episodeRACK related stats RACK recovery episodes
u_int32_ttcps_rack_reordering_timeout_recovery_episodeRACK recovery episodes due to reordering timeout
u_int32_ttcps_rack_rexmitsRACK rexmit segments
u_int32_ttcps_bg_rcvtotaltotal background packets received
u_int32_ttcps_rxtfindropdrop conn after retransmitting FIN
u_int32_ttcps_fcholdpacketpackets withheld because of flow control
u_int32_ttcps_limited_txtLimited transmit used
u_int32_ttcps_early_rexmtEarly retransmit used
u_int32_ttcps_sack_ackadvCumulative ack advanced along with sack
u_int32_ttcps_rcv_swcsumChecksum related stats tcp swcksum (inbound), packets
u_int32_ttcps_rcv_swcsum_bytestcp swcksum (inbound), bytes
u_int32_ttcps_rcv6_swcsumtcp6 swcksum (inbound), packets
u_int32_ttcps_rcv6_swcsum_bytestcp6 swcksum (inbound), bytes
u_int32_ttcps_snd_swcsumtcp swcksum (outbound), packets
u_int32_ttcps_snd_swcsum_bytestcp swcksum (outbound), bytes
u_int32_ttcps_snd6_swcsumtcp6 swcksum (outbound), packets
u_int32_ttcps_snd6_swcsum_bytestcp6 swcksum (outbound), bytes
u_int32_ttcps_invalid_mpcapMPTCP Related stats Invalid MPTCP capable opts
u_int32_ttcps_invalid_joinsInvalid MPTCP joins
u_int32_ttcps_mpcap_fallbackTCP fallback in primary
u_int32_ttcps_join_fallbackNo MPTCP in secondary
u_int32_ttcps_estab_fallbackDSS option dropped
u_int32_ttcps_invalid_optCatchall error stat
u_int32_ttcps_mp_reducedwinReduced subflow window
u_int32_ttcps_mp_badcsumBad DSS csum
u_int32_ttcps_mp_oodataOut of order data
u_int32_ttcps_mp_switchesnumber of subflow switch
u_int32_ttcps_mp_rcvtotalnumber of rcvd packets
u_int32_ttcps_mp_rcvbytesnumber of bytes received
u_int32_ttcps_mp_sndpacksnumber of data packs sent
u_int32_ttcps_mp_sndbytesnumber of bytes sent
u_int32_ttcps_join_rxmtsjoin ack retransmits
u_int32_ttcps_tailloss_rtoRTO due to tail loss
u_int32_ttcps_reordered_pktspackets reorderd
u_int32_ttcps_recovered_pktsrecovered after loss
u_int32_ttcps_ptoprobe timeout
u_int32_ttcps_rto_after_ptoRTO after a probe
u_int32_ttcps_tlp_recoveryTLP induced fast recovery
u_int32_ttcps_tlp_recoverlastpktTLP recoverd last pkt
u_int32_ttcps_ecn_client_successclient-side connection negotiated ECN
u_int32_ttcps_ecn_recv_eceECE received, sent CWR
u_int32_ttcps_ecn_sent_eceSent ECE notification
u_int32_ttcps_detect_reorderingDetect pkt reordering
u_int32_ttcps_delay_recoveryDelay fast recovery
u_int32_ttcps_avoid_rxmtRetransmission was avoided
u_int32_ttcps_pto_in_recoveryrescue retransmit in fast recovery
u_int32_ttcps_pmtudbh_revertedPMTU Blackhole detection, segment size reverted
u_int32_ttcps_dsack_acklossDSACK related statistics ignore DSACK due to ack loss
u_int32_ttcps_dsack_badrexmtDSACK based bad rexmt recovery
u_int32_ttcps_dsack_sentSent DSACK notification
u_int32_ttcps_dsack_recvdReceived a valid DSACK option
u_int32_ttcps_dsack_recvd_oldReceived an out of window DSACK option
u_int32_ttcps_mp_sel_rttMPTCP Subflow selection stats By RTT comparison
u_int32_ttcps_mp_sel_rtoBy RTO comparison
u_int32_ttcps_mp_num_probesNumber of probes sent
u_int32_ttcps_mp_verdowngradeMPTCP version downgrade
u_int32_ttcps_drop_after_sleepdrop after long AP sleep
u_int32_ttcps_probe_ifprobe packets after interface availability
u_int32_ttcps_probe_if_conflictCan't send probe packets for interface
u_int32_ttcps_ecn_client_setupAttempted ECN setup from client side
u_int32_ttcps_ecn_server_setupAttempted ECN setup from server side
u_int32_ttcps_ecn_server_successserver-side connection negotiated ECN
u_int32_ttcps_ecn_ace_syn_not_ectreceived AccECN SYN packet with Not-ECT
u_int32_ttcps_ecn_ace_syn_ect1received AccECN SYN packet with ECT1
u_int32_ttcps_ecn_ace_syn_ect0received AccECN SYN packet with ECT0
u_int32_ttcps_ecn_ace_syn_cereceived AccECN SYN packet with CE
u_int32_ttcps_ecn_lost_synackLost SYN-ACK with ECN setup
u_int32_ttcps_ecn_lost_synLost SYN with ECN setup
u_int32_ttcps_ecn_not_supportedServer did not support ECN setup
u_int32_ttcps_ecn_recv_ceReceived CE from the network
u_int32_ttcps_ecn_ace_recv_ceCE count received in ACE field
u_int32_ttcps_ecn_conn_recv_ceNumber of connections received CE atleast once
u_int32_ttcps_ecn_conn_recv_eceNumber of connections received ECE atleast once
u_int32_ttcps_ecn_conn_plnoceNumber of connections that received no CE and sufferred packet loss
u_int32_ttcps_ecn_conn_pl_ceNumber of connections that received CE and sufferred packet loss
u_int32_ttcps_ecn_conn_nopl_ceNumber of connections that received CE and sufferred no packet loss
u_int32_ttcps_ecn_fallback_synlossNumber of times we did fall back due to SYN-Loss
u_int32_ttcps_ecn_fallback_reorderNumber of times we fallback because we detected the PAWS-issue
u_int32_ttcps_ecn_fallback_ceNumber of times we fallback because we received too many CEs
u_int32_ttcps_tfo_syn_data_rcvTFO-related statistics Received a SYN+data with valid cookie
u_int32_ttcps_tfo_cookie_req_rcvReceived a TFO cookie-request
u_int32_ttcps_tfo_cookie_sentOffered a TFO-cookie to the client
u_int32_ttcps_tfo_cookie_invalidReceived an invalid TFO-cookie
u_int32_ttcps_tfo_cookie_reqCookie requested with the SYN
u_int32_ttcps_tfo_cookie_rcvCookie received in a SYN/ACK
u_int32_ttcps_tfo_syn_data_sentSYN+data+cookie sent
u_int32_ttcps_tfo_syn_data_ackedSYN+data has been acknowledged
u_int32_ttcps_tfo_syn_lossSYN+TFO has been lost and we fallback
u_int32_ttcps_tfo_blackholeTFO got blackholed by a middlebox.
u_int32_ttcps_tfo_cookie_wrongTFO-cookie we sent was wrong
u_int32_ttcps_tfo_no_cookie_rcvWe asked for a cookie but didn't get one
u_int32_ttcps_tfo_heuristics_disableTFO got disabled due to heuristics
u_int32_ttcps_tfo_sndblackholeTFO got blackholed in the sending direction
u_int32_ttcps_mss_to_defaultChange MSS to default using link status report
u_int32_ttcps_mss_to_mediumChange MSS to medium using link status report
u_int32_ttcps_mss_to_lowChange MSS to low using link status report
u_int32_ttcps_ecn_fallback_droprstECN fallback caused by connection drop due to RST
u_int32_ttcps_ecn_fallback_droprxmtECN fallback due to drop after multiple retransmits
u_int32_ttcps_ecn_fallback_synrstECN fallback due to rst after syn
u_int32_ttcps_mptcp_rcvmemdropMPTCP packets dropped for lack of memory
u_int32_ttcps_mptcp_rcvduppackMPTCP duplicate-only packets received
u_int32_ttcps_mptcp_rcvpackafterwinMPTCP packets with data after window
u_int32_ttcps_timer_drift_le_1_msTCP timer statistics Timer drift less or equal to 1 ms
u_int32_ttcps_timer_drift_le_10_msTimer drift less or equal to 10 ms
u_int32_ttcps_timer_drift_le_20_msTimer drift less or equal to 20 ms
u_int32_ttcps_timer_drift_le_50_msTimer drift less or equal to 50 ms
u_int32_ttcps_timer_drift_le_100_msTimer drift less or equal to 100 ms
u_int32_ttcps_timer_drift_le_200_msTimer drift less or equal to 200 ms
u_int32_ttcps_timer_drift_le_500_msTimer drift less or equal to 500 ms
u_int32_ttcps_timer_drift_le_1000_msTimer drift less or equal to 1000 ms
u_int32_ttcps_timer_drift_gt_1000_msTimer drift greater than 1000 ms
u_int32_ttcps_mptcp_handover_attemptTotal number of MPTCP-attempts using handover mode
u_int32_ttcps_mptcp_interactive_attemptTotal number of MPTCP-attempts using interactive mode
u_int32_ttcps_mptcp_aggregate_attemptTotal number of MPTCP-attempts using aggregate mode
u_int32_ttcps_mptcp_fp_handover_attemptSame as previous three but only for first-party apps
u_int32_ttcps_mptcp_fp_interactive_attempt
u_int32_ttcps_mptcp_fp_aggregate_attempt
u_int32_ttcps_mptcp_heuristic_fallbackTotal number of MPTCP-connections that fell back due to heuristics
u_int32_ttcps_mptcp_fp_heuristic_fallbackSame as previous but for first-party apps
u_int32_ttcps_mptcp_handover_success_wifiTotal number of successfull handover-mode connections that *started* on WiFi
u_int32_ttcps_mptcp_handover_success_cellTotal number of successfull handover-mode connections that *started* on Cell
u_int32_ttcps_mptcp_interactive_successTotal number of interactive-mode connections that negotiated MPTCP
u_int32_ttcps_mptcp_aggregate_successSame as previous but for aggregate
u_int32_ttcps_mptcp_fp_handover_success_wifiSame as previous four, but for first-party apps
u_int32_ttcps_mptcp_fp_handover_success_cell
u_int32_ttcps_mptcp_fp_interactive_success
u_int32_ttcps_mptcp_fp_aggregate_success
u_int32_ttcps_mptcp_handover_cell_from_wifiTotal number of connections that use cell in handover-mode (coming from WiFi)
u_int32_ttcps_mptcp_handover_wifi_from_cellTotal number of connections that use WiFi in handover-mode (coming from cell)
u_int32_ttcps_mptcp_interactive_cell_from_wifiTotal number of connections that use cell in interactive mode (coming from WiFi)
u_int64_ttcps_mptcp_handover_cell_bytesTotal number of bytes sent on cell in handover-mode (on new subflows, ignoring initial one)
u_int64_ttcps_mptcp_interactive_cell_bytesSame as previous but for interactive
u_int64_ttcps_mptcp_aggregate_cell_bytes
u_int64_ttcps_mptcp_handover_all_bytesTotal number of bytes sent in handover
u_int64_ttcps_mptcp_interactive_all_bytes
u_int64_ttcps_mptcp_aggregate_all_bytes
u_int32_ttcps_mptcp_back_to_wifiTotal number of connections that succeed to move traffic away from cell (when starting on cell)
u_int32_ttcps_mptcp_wifi_proxyTotal number of new subflows that fell back to regular TCP on cell
u_int32_ttcps_mptcp_cell_proxyTotal number of new subflows that fell back to regular TCP on WiFi
u_int32_ttcps_ka_offload_dropsTCP offload statistics Keep alive drops for timeout reported by firmware
u_int32_ttcps_mptcp_triggered_cellTotal number of times an MPTCP-connection triggered cell bringup
u_int32_ttcps_fin_timeout_drops
u_int64_ttcps_rst_dup_suppressedRST compression statistics
u_int64_ttcps_rst_not_suppressed

structtcpstat_local

size 152, align 8
u_int64_tbadformat
u_int64_tunspecv6
u_int64_tsynfin
u_int64_tbadformatipsec
u_int64_tnoconnnolist
u_int64_tnoconnlist
u_int64_tlistbadsyn
u_int64_ticmp6unreach
u_int64_tdeprecate6
u_int64_tooopacket
u_int64_trstinsynrcv
u_int64_tdospacket
u_int64_tcleanup
u_int64_tsynwindow
u_int64_tlinkheur_stealthdrop
u_int64_tlinkheur_noackpri
u_int64_tlinkheur_comprxmt
u_int64_tlinkheur_synrxmt
u_int64_tlinkheur_rxmtfloor

structxtcpcb

size 524, align 4
u_int32_txt_len
struct inpcbxt_inp
struct tcpcbxt_tp
struct xsocketxt_socket
u_quad_txt_alignment_hack

structxtcpcb64

size 472, align 4
u_int32_txt_len
struct xinpcb64xt_inpcb
u_int64_tt_segq
intt_dupacksconsecutive dup acks recd
int[4]t_timertcp timers
intt_statestate of this connection
u_intt_flags
intt_force1 if forcing out a byte
tcp_seqsnd_unasend unacknowledged
tcp_seqsnd_maxhighest sequence number sent; used to recognize retransmits
tcp_seqsnd_nxtsend next
tcp_seqsnd_upsend urgent pointer
tcp_seqsnd_wl1window update seg seq number
tcp_seqsnd_wl2window update seg ack number
tcp_seqissinitial send sequence number
tcp_seqirsinitial receive sequence number
tcp_seqrcv_nxtreceive next
tcp_seqrcv_advadvertised window
u_int32_trcv_wndreceive window
tcp_seqrcv_upreceive urgent pointer
u_int32_tsnd_wndsend window
u_int32_tsnd_cwndcongestion-controlled window
u_int32_tsnd_ssthreshsnd_cwnd size threshold for for slow start exponential to linear switch
u_intt_maxopdmss plus options
u_int32_tt_rcvtimetime at which a packet was received
u_int32_tt_starttimetime connection was established
intt_rtttimeround trip time
tcp_seqt_rtseqsequence number being timed
intt_rxtcurcurrent retransmit value (ticks)
u_intt_maxsegmaximum segment size
intt_srttsmoothed round-trip time
intt_rttvarvariance in round-trip time
intt_rxtshiftlog(2) of rexmt exp. backoff
u_intt_rttminminimum rtt allowed
u_int32_tt_rttupdatednumber of times rtt sampled
u_int32_tmax_sndwndlargest window peer has offered
intt_softerrorpossible error not yet reported
chart_oobflagsout-of-band data have some
chart_iobcinput character
u_charsnd_scaleRFC 1323 variables window scaling for send window
u_charrcv_scalewindow scaling for recv window
u_charrequest_r_scalepending window scaling
u_charrequested_s_scale
u_int32_tts_recenttimestamp echo data
u_int32_tts_recent_agewhen last updated
tcp_seqlast_ack_sent
tcp_cccc_sendRFC 1644 variables send connection count
tcp_cccc_recvreceive connection count
tcp_seqsnd_recoverfor use in fast recovery
u_int32_tsnd_cwnd_prevexperimental cwnd prior to retransmit
u_int32_tsnd_ssthresh_prevssthresh prior to retransmit
u_int32_tt_badrxtwinwindow for retransmit recovery
u_quad_txt_alignment_hack

macroTCPCTL_DO_RFC1323

Names for TCP sysctl objects
#define TCPCTL_DO_RFC1323 1
use RFC-1323 extensions

macroTCPCTL_DO_RFC1644

#define TCPCTL_DO_RFC1644 2
use RFC-1644 extensions

macroTCPCTL_MSSDFLT

#define TCPCTL_MSSDFLT 3
MSS default

macroTCPCTL_STATS

#define TCPCTL_STATS 4
statistics (read-only)

macroTCPCTL_RTTDFLT

#define TCPCTL_RTTDFLT 5
default RTT estimate

macroTCPCTL_KEEPIDLE

#define TCPCTL_KEEPIDLE 6
keepalive idle timer

macroTCPCTL_KEEPINTVL

#define TCPCTL_KEEPINTVL 7
interval to send keepalives

macroTCPCTL_SENDSPACE

#define TCPCTL_SENDSPACE 8
send buffer space

macroTCPCTL_RECVSPACE

#define TCPCTL_RECVSPACE 9
receive buffer space

macroTCPCTL_KEEPINIT

#define TCPCTL_KEEPINIT 10
timeout for establishing syn

macroTCPCTL_PCBLIST

#define TCPCTL_PCBLIST 11
list of all outstanding PCBs

macroTCPCTL_DELACKTIME

#define TCPCTL_DELACKTIME 12
time before sending delayed ACK

macroTCPCTL_V6MSSDFLT

#define TCPCTL_V6MSSDFLT 13
MSS default for IPv6

macroTCPCTL_MAXID

#define TCPCTL_MAXID 14