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freebsd/sys/netinet/tcp_var.h
John Baldwin 672dc4aea2 TCP reuses t_rxtshift to determine the backoff timer used for both the
persist state and the retransmit timer.  However, the code that implements
"bad retransmit recovery" only checks t_rxtshift to see if an ACK has been
received in during the first retransmit timeout window.  As a result, if
ticks has wrapped over to a negative value and a socket is in the persist
state, it can incorrectly treat an ACK from the remote peer as a
"bad retransmit recovery" and restore saved values such as snd_ssthresh and
snd_cwnd.  However, if the socket has never had a retransmit timeout, then
these saved values will be zero, so snd_ssthresh and snd_cwnd will be set
to 0.

If the socket is in fast recovery (this can be caused by excessive
duplicate ACKs such as those fixed by 220794), then each ACK that arrives
triggers either NewReno or SACK partial ACK handling which clamps snd_cwnd
to be no larger than snd_ssthresh.  In effect, the socket's send window
is permamently stuck at 0 even though the remote peer is advertising a
much larger window and pending data is only sent via TCP window probes
(so one byte every few seconds).

Fix this by adding a new TCP pcb flag (TF_PREVVALID) that indicates that
the various snd_*_prev fields in the pcb are valid and only perform
"bad retransmit recovery" if this flag is set in the pcb.  The flag is set
on the first retransmit timeout that occurs and is cleared on subsequent
retransmit timeouts or when entering the persist state.

Reviewed by:	bz
MFC after:	2 weeks
2011-04-29 15:40:12 +00:00

737 lines
28 KiB
C

/*-
* Copyright (c) 1982, 1986, 1993, 1994, 1995
* The Regents of the University of California. 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.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
*
* @(#)tcp_var.h 8.4 (Berkeley) 5/24/95
* $FreeBSD$
*/
#ifndef _NETINET_TCP_VAR_H_
#define _NETINET_TCP_VAR_H_
#include <netinet/tcp.h>
#ifdef _KERNEL
#include <net/vnet.h>
/*
* Kernel variables for tcp.
*/
VNET_DECLARE(int, tcp_do_rfc1323);
#define V_tcp_do_rfc1323 VNET(tcp_do_rfc1323)
#endif /* _KERNEL */
/* TCP segment queue entry */
struct tseg_qent {
LIST_ENTRY(tseg_qent) tqe_q;
int tqe_len; /* TCP segment data length */
struct tcphdr *tqe_th; /* a pointer to tcp header */
struct mbuf *tqe_m; /* mbuf contains packet */
};
LIST_HEAD(tsegqe_head, tseg_qent);
struct sackblk {
tcp_seq start; /* start seq no. of sack block */
tcp_seq end; /* end seq no. */
};
struct sackhole {
tcp_seq start; /* start seq no. of hole */
tcp_seq end; /* end seq no. */
tcp_seq rxmit; /* next seq. no in hole to be retransmitted */
TAILQ_ENTRY(sackhole) scblink; /* scoreboard linkage */
};
struct sackhint {
struct sackhole *nexthole;
int sack_bytes_rexmit;
tcp_seq last_sack_ack; /* Most recent/largest sacked ack */
int ispare; /* explicit pad for 64bit alignment */
uint64_t _pad[2]; /* 1 sacked_bytes, 1 TBD */
};
struct tcptemp {
u_char tt_ipgen[40]; /* the size must be of max ip header, now IPv6 */
struct tcphdr tt_t;
};
#define tcp6cb tcpcb /* for KAME src sync over BSD*'s */
/* Neighbor Discovery, Neighbor Unreachability Detection Upper layer hint. */
#ifdef INET6
#define ND6_HINT(tp) \
do { \
if ((tp) && (tp)->t_inpcb && \
((tp)->t_inpcb->inp_vflag & INP_IPV6) != 0) \
nd6_nud_hint(NULL, NULL, 0); \
} while (0)
#else
#define ND6_HINT(tp)
#endif
/*
* Tcp control block, one per tcp; fields:
* Organized for 16 byte cacheline efficiency.
*/
struct tcpcb {
struct tsegqe_head t_segq; /* segment reassembly queue */
void *t_pspare[2]; /* new reassembly queue */
int t_segqlen; /* segment reassembly queue length */
int t_dupacks; /* consecutive dup acks recd */
struct tcp_timer *t_timers; /* All the TCP timers in one struct */
struct inpcb *t_inpcb; /* back pointer to internet pcb */
int t_state; /* state of this connection */
u_int t_flags;
struct vnet *t_vnet; /* back pointer to parent vnet */
tcp_seq snd_una; /* send unacknowledged */
tcp_seq snd_max; /* highest sequence number sent;
* used to recognize retransmits
*/
tcp_seq snd_nxt; /* send next */
tcp_seq snd_up; /* send urgent pointer */
tcp_seq snd_wl1; /* window update seg seq number */
tcp_seq snd_wl2; /* window update seg ack number */
tcp_seq iss; /* initial send sequence number */
tcp_seq irs; /* initial receive sequence number */
tcp_seq rcv_nxt; /* receive next */
tcp_seq rcv_adv; /* advertised window */
u_long rcv_wnd; /* receive window */
tcp_seq rcv_up; /* receive urgent pointer */
u_long snd_wnd; /* send window */
u_long snd_cwnd; /* congestion-controlled window */
u_long snd_spare1; /* unused */
u_long snd_ssthresh; /* snd_cwnd size threshold for
* for slow start exponential to
* linear switch
*/
u_long snd_spare2; /* unused */
tcp_seq snd_recover; /* for use in NewReno Fast Recovery */
u_int t_maxopd; /* mss plus options */
u_int t_rcvtime; /* inactivity time */
u_int t_starttime; /* time connection was established */
u_int t_rtttime; /* RTT measurement start time */
tcp_seq t_rtseq; /* sequence number being timed */
u_int t_bw_spare1; /* unused */
tcp_seq t_bw_spare2; /* unused */
int t_rxtcur; /* current retransmit value (ticks) */
u_int t_maxseg; /* maximum segment size */
int t_srtt; /* smoothed round-trip time */
int t_rttvar; /* variance in round-trip time */
int t_rxtshift; /* log(2) of rexmt exp. backoff */
u_int t_rttmin; /* minimum rtt allowed */
u_int t_rttbest; /* best rtt we've seen */
u_long t_rttupdated; /* number of times rtt sampled */
u_long max_sndwnd; /* largest window peer has offered */
int t_softerror; /* possible error not yet reported */
/* out-of-band data */
char t_oobflags; /* have some */
char t_iobc; /* input character */
/* RFC 1323 variables */
u_char snd_scale; /* window scaling for send window */
u_char rcv_scale; /* window scaling for recv window */
u_char request_r_scale; /* pending window scaling */
u_int32_t ts_recent; /* timestamp echo data */
u_int ts_recent_age; /* when last updated */
u_int32_t ts_offset; /* our timestamp offset */
tcp_seq last_ack_sent;
/* experimental */
u_long snd_cwnd_prev; /* cwnd prior to retransmit */
u_long snd_ssthresh_prev; /* ssthresh prior to retransmit */
tcp_seq snd_recover_prev; /* snd_recover prior to retransmit */
int t_sndzerowin; /* zero-window updates sent */
u_int t_badrxtwin; /* window for retransmit recovery */
u_char snd_limited; /* segments limited transmitted */
/* SACK related state */
int snd_numholes; /* number of holes seen by sender */
TAILQ_HEAD(sackhole_head, sackhole) snd_holes;
/* SACK scoreboard (sorted) */
tcp_seq snd_fack; /* last seq number(+1) sack'd by rcv'r*/
int rcv_numsacks; /* # distinct sack blks present */
struct sackblk sackblks[MAX_SACK_BLKS]; /* seq nos. of sack blocks */
tcp_seq sack_newdata; /* New data xmitted in this recovery
episode starts at this seq number */
struct sackhint sackhint; /* SACK scoreboard hint */
int t_rttlow; /* smallest observerved RTT */
u_int32_t rfbuf_ts; /* recv buffer autoscaling timestamp */
int rfbuf_cnt; /* recv buffer autoscaling byte count */
struct toe_usrreqs *t_tu; /* offload operations vector */
int t_sndrexmitpack; /* retransmit packets sent */
int t_rcvoopack; /* out-of-order packets received */
void *t_toe; /* TOE pcb pointer */
int t_bytes_acked; /* # bytes acked during current RTT */
struct cc_algo *cc_algo; /* congestion control algorithm */
struct cc_var *ccv; /* congestion control specific vars */
struct osd *osd; /* storage for Khelp module data */
int t_ispare; /* explicit pad for 64bit alignment */
void *t_pspare2[4]; /* 4 TBD */
uint64_t _pad[12]; /* 7 UTO, 5 TBD (1-2 CC/RTT?) */
};
/*
* Flags and utility macros for the t_flags field.
*/
#define TF_ACKNOW 0x000001 /* ack peer immediately */
#define TF_DELACK 0x000002 /* ack, but try to delay it */
#define TF_NODELAY 0x000004 /* don't delay packets to coalesce */
#define TF_NOOPT 0x000008 /* don't use tcp options */
#define TF_SENTFIN 0x000010 /* have sent FIN */
#define TF_REQ_SCALE 0x000020 /* have/will request window scaling */
#define TF_RCVD_SCALE 0x000040 /* other side has requested scaling */
#define TF_REQ_TSTMP 0x000080 /* have/will request timestamps */
#define TF_RCVD_TSTMP 0x000100 /* a timestamp was received in SYN */
#define TF_SACK_PERMIT 0x000200 /* other side said I could SACK */
#define TF_NEEDSYN 0x000400 /* send SYN (implicit state) */
#define TF_NEEDFIN 0x000800 /* send FIN (implicit state) */
#define TF_NOPUSH 0x001000 /* don't push */
#define TF_PREVVALID 0x002000 /* saved values for bad rxmit valid */
#define TF_MORETOCOME 0x010000 /* More data to be appended to sock */
#define TF_LQ_OVERFLOW 0x020000 /* listen queue overflow */
#define TF_LASTIDLE 0x040000 /* connection was previously idle */
#define TF_RXWIN0SENT 0x080000 /* sent a receiver win 0 in response */
#define TF_FASTRECOVERY 0x100000 /* in NewReno Fast Recovery */
#define TF_WASFRECOVERY 0x200000 /* was in NewReno Fast Recovery */
#define TF_SIGNATURE 0x400000 /* require MD5 digests (RFC2385) */
#define TF_FORCEDATA 0x800000 /* force out a byte */
#define TF_TSO 0x1000000 /* TSO enabled on this connection */
#define TF_TOE 0x2000000 /* this connection is offloaded */
#define TF_ECN_PERMIT 0x4000000 /* connection ECN-ready */
#define TF_ECN_SND_CWR 0x8000000 /* ECN CWR in queue */
#define TF_ECN_SND_ECE 0x10000000 /* ECN ECE in queue */
#define TF_CONGRECOVERY 0x20000000 /* congestion recovery mode */
#define TF_WASCRECOVERY 0x40000000 /* was in congestion recovery */
#define IN_FASTRECOVERY(t_flags) (t_flags & TF_FASTRECOVERY)
#define ENTER_FASTRECOVERY(t_flags) t_flags |= TF_FASTRECOVERY
#define EXIT_FASTRECOVERY(t_flags) t_flags &= ~TF_FASTRECOVERY
#define IN_CONGRECOVERY(t_flags) (t_flags & TF_CONGRECOVERY)
#define ENTER_CONGRECOVERY(t_flags) t_flags |= TF_CONGRECOVERY
#define EXIT_CONGRECOVERY(t_flags) t_flags &= ~TF_CONGRECOVERY
#define IN_RECOVERY(t_flags) (t_flags & (TF_CONGRECOVERY | TF_FASTRECOVERY))
#define ENTER_RECOVERY(t_flags) t_flags |= (TF_CONGRECOVERY | TF_FASTRECOVERY)
#define EXIT_RECOVERY(t_flags) t_flags &= ~(TF_CONGRECOVERY | TF_FASTRECOVERY)
#define BYTES_THIS_ACK(tp, th) (th->th_ack - tp->snd_una)
/*
* Flags for the t_oobflags field.
*/
#define TCPOOB_HAVEDATA 0x01
#define TCPOOB_HADDATA 0x02
#ifdef TCP_SIGNATURE
/*
* Defines which are needed by the xform_tcp module and tcp_[in|out]put
* for SADB verification and lookup.
*/
#define TCP_SIGLEN 16 /* length of computed digest in bytes */
#define TCP_KEYLEN_MIN 1 /* minimum length of TCP-MD5 key */
#define TCP_KEYLEN_MAX 80 /* maximum length of TCP-MD5 key */
/*
* Only a single SA per host may be specified at this time. An SPI is
* needed in order for the KEY_ALLOCSA() lookup to work.
*/
#define TCP_SIG_SPI 0x1000
#endif /* TCP_SIGNATURE */
/*
* Structure to hold TCP options that are only used during segment
* processing (in tcp_input), but not held in the tcpcb.
* It's basically used to reduce the number of parameters
* to tcp_dooptions and tcp_addoptions.
* The binary order of the to_flags is relevant for packing of the
* options in tcp_addoptions.
*/
struct tcpopt {
u_int64_t to_flags; /* which options are present */
#define TOF_MSS 0x0001 /* maximum segment size */
#define TOF_SCALE 0x0002 /* window scaling */
#define TOF_SACKPERM 0x0004 /* SACK permitted */
#define TOF_TS 0x0010 /* timestamp */
#define TOF_SIGNATURE 0x0040 /* TCP-MD5 signature option (RFC2385) */
#define TOF_SACK 0x0080 /* Peer sent SACK option */
#define TOF_MAXOPT 0x0100
u_int32_t to_tsval; /* new timestamp */
u_int32_t to_tsecr; /* reflected timestamp */
u_char *to_sacks; /* pointer to the first SACK blocks */
u_char *to_signature; /* pointer to the TCP-MD5 signature */
u_int16_t to_mss; /* maximum segment size */
u_int8_t to_wscale; /* window scaling */
u_int8_t to_nsacks; /* number of SACK blocks */
};
/*
* Flags for tcp_dooptions.
*/
#define TO_SYN 0x01 /* parse SYN-only options */
struct hc_metrics_lite { /* must stay in sync with hc_metrics */
u_long rmx_mtu; /* MTU for this path */
u_long rmx_ssthresh; /* outbound gateway buffer limit */
u_long rmx_rtt; /* estimated round trip time */
u_long rmx_rttvar; /* estimated rtt variance */
u_long rmx_bandwidth; /* estimated bandwidth */
u_long rmx_cwnd; /* congestion window */
u_long rmx_sendpipe; /* outbound delay-bandwidth product */
u_long rmx_recvpipe; /* inbound delay-bandwidth product */
};
#ifndef _NETINET_IN_PCB_H_
struct in_conninfo;
#endif /* _NETINET_IN_PCB_H_ */
struct tcptw {
struct inpcb *tw_inpcb; /* XXX back pointer to internet pcb */
tcp_seq snd_nxt;
tcp_seq rcv_nxt;
tcp_seq iss;
tcp_seq irs;
u_short last_win; /* cached window value */
u_short tw_so_options; /* copy of so_options */
struct ucred *tw_cred; /* user credentials */
u_int32_t t_recent;
u_int32_t ts_offset; /* our timestamp offset */
u_int t_starttime;
int tw_time;
TAILQ_ENTRY(tcptw) tw_2msl;
};
#define intotcpcb(ip) ((struct tcpcb *)(ip)->inp_ppcb)
#define intotw(ip) ((struct tcptw *)(ip)->inp_ppcb)
#define sototcpcb(so) (intotcpcb(sotoinpcb(so)))
/*
* The smoothed round-trip time and estimated variance
* are stored as fixed point numbers scaled by the values below.
* For convenience, these scales are also used in smoothing the average
* (smoothed = (1/scale)sample + ((scale-1)/scale)smoothed).
* With these scales, srtt has 3 bits to the right of the binary point,
* and thus an "ALPHA" of 0.875. rttvar has 2 bits to the right of the
* binary point, and is smoothed with an ALPHA of 0.75.
*/
#define TCP_RTT_SCALE 32 /* multiplier for srtt; 3 bits frac. */
#define TCP_RTT_SHIFT 5 /* shift for srtt; 3 bits frac. */
#define TCP_RTTVAR_SCALE 16 /* multiplier for rttvar; 2 bits */
#define TCP_RTTVAR_SHIFT 4 /* shift for rttvar; 2 bits */
#define TCP_DELTA_SHIFT 2 /* see tcp_input.c */
/*
* The initial retransmission should happen at rtt + 4 * rttvar.
* Because of the way we do the smoothing, srtt and rttvar
* will each average +1/2 tick of bias. When we compute
* the retransmit timer, we want 1/2 tick of rounding and
* 1 extra tick because of +-1/2 tick uncertainty in the
* firing of the timer. The bias will give us exactly the
* 1.5 tick we need. But, because the bias is
* statistical, we have to test that we don't drop below
* the minimum feasible timer (which is 2 ticks).
* This version of the macro adapted from a paper by Lawrence
* Brakmo and Larry Peterson which outlines a problem caused
* by insufficient precision in the original implementation,
* which results in inappropriately large RTO values for very
* fast networks.
*/
#define TCP_REXMTVAL(tp) \
max((tp)->t_rttmin, (((tp)->t_srtt >> (TCP_RTT_SHIFT - TCP_DELTA_SHIFT)) \
+ (tp)->t_rttvar) >> TCP_DELTA_SHIFT)
/*
* TCP statistics.
* Many of these should be kept per connection,
* but that's inconvenient at the moment.
*/
struct tcpstat {
u_long tcps_connattempt; /* connections initiated */
u_long tcps_accepts; /* connections accepted */
u_long tcps_connects; /* connections established */
u_long tcps_drops; /* connections dropped */
u_long tcps_conndrops; /* embryonic connections dropped */
u_long tcps_minmssdrops; /* average minmss too low drops */
u_long tcps_closed; /* conn. closed (includes drops) */
u_long tcps_segstimed; /* segs where we tried to get rtt */
u_long tcps_rttupdated; /* times we succeeded */
u_long tcps_delack; /* delayed acks sent */
u_long tcps_timeoutdrop; /* conn. dropped in rxmt timeout */
u_long tcps_rexmttimeo; /* retransmit timeouts */
u_long tcps_persisttimeo; /* persist timeouts */
u_long tcps_keeptimeo; /* keepalive timeouts */
u_long tcps_keepprobe; /* keepalive probes sent */
u_long tcps_keepdrops; /* connections dropped in keepalive */
u_long tcps_sndtotal; /* total packets sent */
u_long tcps_sndpack; /* data packets sent */
u_long tcps_sndbyte; /* data bytes sent */
u_long tcps_sndrexmitpack; /* data packets retransmitted */
u_long tcps_sndrexmitbyte; /* data bytes retransmitted */
u_long tcps_sndrexmitbad; /* unnecessary packet retransmissions */
u_long tcps_sndacks; /* ack-only packets sent */
u_long tcps_sndprobe; /* window probes sent */
u_long tcps_sndurg; /* packets sent with URG only */
u_long tcps_sndwinup; /* window update-only packets sent */
u_long tcps_sndctrl; /* control (SYN|FIN|RST) packets sent */
u_long tcps_rcvtotal; /* total packets received */
u_long tcps_rcvpack; /* packets received in sequence */
u_long tcps_rcvbyte; /* bytes received in sequence */
u_long tcps_rcvbadsum; /* packets received with ccksum errs */
u_long tcps_rcvbadoff; /* packets received with bad offset */
u_long tcps_rcvmemdrop; /* packets dropped for lack of memory */
u_long tcps_rcvshort; /* packets received too short */
u_long tcps_rcvduppack; /* duplicate-only packets received */
u_long tcps_rcvdupbyte; /* duplicate-only bytes received */
u_long tcps_rcvpartduppack; /* packets with some duplicate data */
u_long tcps_rcvpartdupbyte; /* dup. bytes in part-dup. packets */
u_long tcps_rcvoopack; /* out-of-order packets received */
u_long tcps_rcvoobyte; /* out-of-order bytes received */
u_long tcps_rcvpackafterwin; /* packets with data after window */
u_long tcps_rcvbyteafterwin; /* bytes rcvd after window */
u_long tcps_rcvafterclose; /* packets rcvd after "close" */
u_long tcps_rcvwinprobe; /* rcvd window probe packets */
u_long tcps_rcvdupack; /* rcvd duplicate acks */
u_long tcps_rcvacktoomuch; /* rcvd acks for unsent data */
u_long tcps_rcvackpack; /* rcvd ack packets */
u_long tcps_rcvackbyte; /* bytes acked by rcvd acks */
u_long tcps_rcvwinupd; /* rcvd window update packets */
u_long tcps_pawsdrop; /* segments dropped due to PAWS */
u_long tcps_predack; /* times hdr predict ok for acks */
u_long tcps_preddat; /* times hdr predict ok for data pkts */
u_long tcps_pcbcachemiss;
u_long tcps_cachedrtt; /* times cached RTT in route updated */
u_long tcps_cachedrttvar; /* times cached rttvar updated */
u_long tcps_cachedssthresh; /* times cached ssthresh updated */
u_long tcps_usedrtt; /* times RTT initialized from route */
u_long tcps_usedrttvar; /* times RTTVAR initialized from rt */
u_long tcps_usedssthresh; /* times ssthresh initialized from rt*/
u_long tcps_persistdrop; /* timeout in persist state */
u_long tcps_badsyn; /* bogus SYN, e.g. premature ACK */
u_long tcps_mturesent; /* resends due to MTU discovery */
u_long tcps_listendrop; /* listen queue overflows */
u_long tcps_badrst; /* ignored RSTs in the window */
u_long tcps_sc_added; /* entry added to syncache */
u_long tcps_sc_retransmitted; /* syncache entry was retransmitted */
u_long tcps_sc_dupsyn; /* duplicate SYN packet */
u_long tcps_sc_dropped; /* could not reply to packet */
u_long tcps_sc_completed; /* successful extraction of entry */
u_long tcps_sc_bucketoverflow; /* syncache per-bucket limit hit */
u_long tcps_sc_cacheoverflow; /* syncache cache limit hit */
u_long tcps_sc_reset; /* RST removed entry from syncache */
u_long tcps_sc_stale; /* timed out or listen socket gone */
u_long tcps_sc_aborted; /* syncache entry aborted */
u_long tcps_sc_badack; /* removed due to bad ACK */
u_long tcps_sc_unreach; /* ICMP unreachable received */
u_long tcps_sc_zonefail; /* zalloc() failed */
u_long tcps_sc_sendcookie; /* SYN cookie sent */
u_long tcps_sc_recvcookie; /* SYN cookie received */
u_long tcps_hc_added; /* entry added to hostcache */
u_long tcps_hc_bucketoverflow; /* hostcache per bucket limit hit */
u_long tcps_finwait2_drops; /* Drop FIN_WAIT_2 connection after time limit */
/* SACK related stats */
u_long tcps_sack_recovery_episode; /* SACK recovery episodes */
u_long tcps_sack_rexmits; /* SACK rexmit segments */
u_long tcps_sack_rexmit_bytes; /* SACK rexmit bytes */
u_long tcps_sack_rcv_blocks; /* SACK blocks (options) received */
u_long tcps_sack_send_blocks; /* SACK blocks (options) sent */
u_long tcps_sack_sboverflow; /* times scoreboard overflowed */
/* ECN related stats */
u_long tcps_ecn_ce; /* ECN Congestion Experienced */
u_long tcps_ecn_ect0; /* ECN Capable Transport */
u_long tcps_ecn_ect1; /* ECN Capable Transport */
u_long tcps_ecn_shs; /* ECN successful handshakes */
u_long tcps_ecn_rcwnd; /* # times ECN reduced the cwnd */
/* TCP_SIGNATURE related stats */
u_long tcps_sig_rcvgoodsig; /* Total matching signature received */
u_long tcps_sig_rcvbadsig; /* Total bad signature received */
u_long tcps_sig_err_buildsig; /* Mismatching signature received */
u_long tcps_sig_err_sigopt; /* No signature expected by socket */
u_long tcps_sig_err_nosigopt; /* No signature provided by segment */
u_long _pad[12]; /* 6 UTO, 6 TBD */
};
#ifdef _KERNEL
/*
* In-kernel consumers can use these accessor macros directly to update
* stats.
*/
#define TCPSTAT_ADD(name, val) V_tcpstat.name += (val)
#define TCPSTAT_INC(name) TCPSTAT_ADD(name, 1)
/*
* Kernel module consumers must use this accessor macro.
*/
void kmod_tcpstat_inc(int statnum);
#define KMOD_TCPSTAT_INC(name) \
kmod_tcpstat_inc(offsetof(struct tcpstat, name) / sizeof(u_long))
/*
* TCP specific helper hook point identifiers.
*/
#define HHOOK_TCP_EST_IN 0
#define HHOOK_TCP_EST_OUT 1
#define HHOOK_TCP_LAST HHOOK_TCP_EST_OUT
struct tcp_hhook_data {
struct tcpcb *tp;
struct tcphdr *th;
struct tcpopt *to;
long len;
int tso;
tcp_seq curack;
};
#endif
/*
* TCB structure exported to user-land via sysctl(3).
* Evil hack: declare only if in_pcb.h and sys/socketvar.h have been
* included. Not all of our clients do.
*/
#if defined(_NETINET_IN_PCB_H_) && defined(_SYS_SOCKETVAR_H_)
struct xtcp_timer {
int tt_rexmt; /* retransmit timer */
int tt_persist; /* retransmit persistence */
int tt_keep; /* keepalive */
int tt_2msl; /* 2*msl TIME_WAIT timer */
int tt_delack; /* delayed ACK timer */
int t_rcvtime; /* Time since last packet received */
};
struct xtcpcb {
size_t xt_len;
struct inpcb xt_inp;
struct tcpcb xt_tp;
struct xsocket xt_socket;
struct xtcp_timer xt_timer;
u_quad_t xt_alignment_hack;
};
#endif
/*
* Names for TCP sysctl objects
*/
#define TCPCTL_DO_RFC1323 1 /* use RFC-1323 extensions */
#define TCPCTL_MSSDFLT 3 /* MSS default */
#define TCPCTL_STATS 4 /* statistics (read-only) */
#define TCPCTL_RTTDFLT 5 /* default RTT estimate */
#define TCPCTL_KEEPIDLE 6 /* keepalive idle timer */
#define TCPCTL_KEEPINTVL 7 /* interval to send keepalives */
#define TCPCTL_SENDSPACE 8 /* send buffer space */
#define TCPCTL_RECVSPACE 9 /* receive buffer space */
#define TCPCTL_KEEPINIT 10 /* timeout for establishing syn */
#define TCPCTL_PCBLIST 11 /* list of all outstanding PCBs */
#define TCPCTL_DELACKTIME 12 /* time before sending delayed ACK */
#define TCPCTL_V6MSSDFLT 13 /* MSS default for IPv6 */
#define TCPCTL_SACK 14 /* Selective Acknowledgement,rfc 2018 */
#define TCPCTL_DROP 15 /* drop tcp connection */
#define TCPCTL_MAXID 16
#define TCPCTL_FINWAIT2_TIMEOUT 17
#define TCPCTL_NAMES { \
{ 0, 0 }, \
{ "rfc1323", CTLTYPE_INT }, \
{ "mssdflt", CTLTYPE_INT }, \
{ "stats", CTLTYPE_STRUCT }, \
{ "rttdflt", CTLTYPE_INT }, \
{ "keepidle", CTLTYPE_INT }, \
{ "keepintvl", CTLTYPE_INT }, \
{ "sendspace", CTLTYPE_INT }, \
{ "recvspace", CTLTYPE_INT }, \
{ "keepinit", CTLTYPE_INT }, \
{ "pcblist", CTLTYPE_STRUCT }, \
{ "delacktime", CTLTYPE_INT }, \
{ "v6mssdflt", CTLTYPE_INT }, \
{ "maxid", CTLTYPE_INT }, \
}
#ifdef _KERNEL
#ifdef SYSCTL_DECL
SYSCTL_DECL(_net_inet_tcp);
SYSCTL_DECL(_net_inet_tcp_sack);
MALLOC_DECLARE(M_TCPLOG);
#endif
VNET_DECLARE(struct inpcbhead, tcb); /* queue of active tcpcb's */
VNET_DECLARE(struct inpcbinfo, tcbinfo);
VNET_DECLARE(struct tcpstat, tcpstat); /* tcp statistics */
extern int tcp_log_in_vain;
VNET_DECLARE(int, tcp_mssdflt); /* XXX */
VNET_DECLARE(int, tcp_minmss);
VNET_DECLARE(int, tcp_delack_enabled);
VNET_DECLARE(int, tcp_do_rfc3390);
VNET_DECLARE(int, path_mtu_discovery);
VNET_DECLARE(int, ss_fltsz);
VNET_DECLARE(int, ss_fltsz_local);
VNET_DECLARE(int, tcp_do_rfc3465);
VNET_DECLARE(int, tcp_abc_l_var);
#define V_tcb VNET(tcb)
#define V_tcbinfo VNET(tcbinfo)
#define V_tcpstat VNET(tcpstat)
#define V_tcp_mssdflt VNET(tcp_mssdflt)
#define V_tcp_minmss VNET(tcp_minmss)
#define V_tcp_delack_enabled VNET(tcp_delack_enabled)
#define V_tcp_do_rfc3390 VNET(tcp_do_rfc3390)
#define V_path_mtu_discovery VNET(path_mtu_discovery)
#define V_ss_fltsz VNET(ss_fltsz)
#define V_ss_fltsz_local VNET(ss_fltsz_local)
#define V_tcp_do_rfc3465 VNET(tcp_do_rfc3465)
#define V_tcp_abc_l_var VNET(tcp_abc_l_var)
VNET_DECLARE(int, tcp_do_sack); /* SACK enabled/disabled */
VNET_DECLARE(int, tcp_sc_rst_sock_fail); /* RST on sock alloc failure */
#define V_tcp_do_sack VNET(tcp_do_sack)
#define V_tcp_sc_rst_sock_fail VNET(tcp_sc_rst_sock_fail)
VNET_DECLARE(int, tcp_do_ecn); /* TCP ECN enabled/disabled */
VNET_DECLARE(int, tcp_ecn_maxretries);
#define V_tcp_do_ecn VNET(tcp_do_ecn)
#define V_tcp_ecn_maxretries VNET(tcp_ecn_maxretries)
VNET_DECLARE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST + 1]);
#define V_tcp_hhh VNET(tcp_hhh)
int tcp_addoptions(struct tcpopt *, u_char *);
int tcp_ccalgounload(struct cc_algo *unload_algo);
struct tcpcb *
tcp_close(struct tcpcb *);
void tcp_discardcb(struct tcpcb *);
void tcp_twstart(struct tcpcb *);
#if 0
int tcp_twrecycleable(struct tcptw *tw);
#endif
void tcp_twclose(struct tcptw *_tw, int _reuse);
void tcp_ctlinput(int, struct sockaddr *, void *);
int tcp_ctloutput(struct socket *, struct sockopt *);
struct tcpcb *
tcp_drop(struct tcpcb *, int);
void tcp_drain(void);
void tcp_init(void);
#ifdef VIMAGE
void tcp_destroy(void);
#endif
void tcp_fini(void *);
char *tcp_log_addrs(struct in_conninfo *, struct tcphdr *, void *,
const void *);
char *tcp_log_vain(struct in_conninfo *, struct tcphdr *, void *,
const void *);
int tcp_reass(struct tcpcb *, struct tcphdr *, int *, struct mbuf *);
void tcp_reass_init(void);
void tcp_reass_flush(struct tcpcb *);
#ifdef VIMAGE
void tcp_reass_destroy(void);
#endif
void tcp_input(struct mbuf *, int);
u_long tcp_maxmtu(struct in_conninfo *, int *);
u_long tcp_maxmtu6(struct in_conninfo *, int *);
void tcp_mss_update(struct tcpcb *, int, struct hc_metrics_lite *, int *);
void tcp_mss(struct tcpcb *, int);
int tcp_mssopt(struct in_conninfo *);
struct inpcb *
tcp_drop_syn_sent(struct inpcb *, int);
struct inpcb *
tcp_mtudisc(struct inpcb *, int);
struct tcpcb *
tcp_newtcpcb(struct inpcb *);
int tcp_output(struct tcpcb *);
void tcp_respond(struct tcpcb *, void *,
struct tcphdr *, struct mbuf *, tcp_seq, tcp_seq, int);
void tcp_tw_init(void);
#ifdef VIMAGE
void tcp_tw_destroy(void);
#endif
void tcp_tw_zone_change(void);
int tcp_twcheck(struct inpcb *, struct tcpopt *, struct tcphdr *,
struct mbuf *, int);
int tcp_twrespond(struct tcptw *, int);
void tcp_setpersist(struct tcpcb *);
#ifdef TCP_SIGNATURE
int tcp_signature_compute(struct mbuf *, int, int, int, u_char *, u_int);
int tcp_signature_verify(struct mbuf *, int, int, int, struct tcpopt *,
struct tcphdr *, u_int);
#endif
void tcp_slowtimo(void);
struct tcptemp *
tcpip_maketemplate(struct inpcb *);
void tcpip_fillheaders(struct inpcb *, void *, void *);
void tcp_timer_activate(struct tcpcb *, int, u_int);
int tcp_timer_active(struct tcpcb *, int);
void tcp_trace(short, short, struct tcpcb *, void *, struct tcphdr *, int);
/*
* All tcp_hc_* functions are IPv4 and IPv6 (via in_conninfo)
*/
void tcp_hc_init(void);
#ifdef VIMAGE
void tcp_hc_destroy(void);
#endif
void tcp_hc_get(struct in_conninfo *, struct hc_metrics_lite *);
u_long tcp_hc_getmtu(struct in_conninfo *);
void tcp_hc_updatemtu(struct in_conninfo *, u_long);
void tcp_hc_update(struct in_conninfo *, struct hc_metrics_lite *);
extern struct pr_usrreqs tcp_usrreqs;
extern u_long tcp_sendspace;
extern u_long tcp_recvspace;
tcp_seq tcp_new_isn(struct tcpcb *);
void tcp_sack_doack(struct tcpcb *, struct tcpopt *, tcp_seq);
void tcp_update_sack_list(struct tcpcb *tp, tcp_seq rcv_laststart, tcp_seq rcv_lastend);
void tcp_clean_sackreport(struct tcpcb *tp);
void tcp_sack_adjust(struct tcpcb *tp);
struct sackhole *tcp_sack_output(struct tcpcb *tp, int *sack_bytes_rexmt);
void tcp_sack_partialack(struct tcpcb *, struct tcphdr *);
void tcp_free_sackholes(struct tcpcb *tp);
int tcp_newreno(struct tcpcb *, struct tcphdr *);
u_long tcp_seq_subtract(u_long, u_long );
void cc_cong_signal(struct tcpcb *tp, struct tcphdr *th, uint32_t type);
#endif /* _KERNEL */
#endif /* _NETINET_TCP_VAR_H_ */