/*
- * Copyright (c) 2000-2008 Apple Inc. All rights reserved.
+ * Copyright (c) 2000-2011 Apple Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
#define _TCPCB_LIST_HEAD(name, type) LIST_HEAD(name, type)
#endif
-#define TCP_RETRANSHZ 10 /* tcp retrans timer (100ms) per hz */
+#define TCP_RETRANSHZ 1000 /* granularity of TCP timestamps, 1ms */
+#define TCP_TIMERHZ 100 /* frequency of TCP fast timer, 100 ms */
+
+/* Minimum time quantum within which the timers are coalesced */
+#define TCP_FASTTIMER_QUANTUM TCP_TIMERHZ /* fast mode, once every 100ms */
+#define TCP_SLOWTIMER_QUANTUM TCP_RETRANSHZ / PR_SLOWHZ /* slow mode, once every 500ms */
+
+#define TCP_RETRANSHZ_TO_USEC 1000
#ifdef KERNEL_PRIVATE
#define N_TIME_WAIT_SLOTS 128 /* must be power of 2 */
+/* Base RTT is stored for N_MIN_RTT_HISTORY slots. This is used to
+ * estimate expected minimum RTT for delay based congestion control
+ * algorithms.
+ */
+#define N_RTT_BASE 5
+
+/* Always allow at least 4 packets worth of recv window when adjusting
+ * recv window using inter-packet arrival jitter.
+ */
+#define MIN_IAJ_WIN 4
+
+/* A variation in delay of this many milliseconds is tolerable. This limit has to
+ * be low but greater than zero. We also use standard deviation on jitter to adjust
+ * this limit for different link and connection types.
+ */
+#define ALLOWED_IAJ 5
+
+/* Ignore the first few packets on a connection until the ACK clock gets going
+ */
+#define IAJ_IGNORE_PKTCNT 40
+
+/* Let the accumulated IAJ value increase by this threshold at most. This limit
+ * will control how many ALLOWED_IAJ measurements a receiver will have to see
+ * before opening the receive window
+ */
+#define ACC_IAJ_HIGH_THRESH 100
+
+/* When accumulated IAJ reaches this value, the receiver starts to react by
+ * closing the window
+ */
+#define ACC_IAJ_REACT_LIMIT 200
+
+/* If the number of small packets (smaller than IAJ packet size) seen on a
+ * connection is more than this threshold, reset the size and learn it again.
+ * This is needed because the sender might send smaller segments after PMTU
+ * discovery and the receiver has to learn the new size.
+ */
+#define RESET_IAJ_SIZE_THRESH 20
+
/*
* Kernel variables for tcp.
*/
struct tcpcb {
struct tsegqe_head t_segq;
int t_dupacks; /* consecutive dup acks recd */
- struct tcptemp *unused; /* unused now: was t_template */
-
- int t_timer[TCPT_NTIMERS]; /* tcp timers */
+ uint32_t t_timer[TCPT_NTIMERS]; /* tcp timers */
+ struct tcptimerentry tentry; /* entry in timer list */
struct inpcb *t_inpcb; /* back pointer to internet pcb */
int t_state; /* state of this connection */
#define TF_RCVD_CC 0x04000 /* a CC was received in SYN */
#define TF_SENDCCNEW 0x08000 /* send CCnew instead of CC in SYN */
#define TF_MORETOCOME 0x10000 /* More data to be appended to sock */
-#define TF_LQ_OVERFLOW 0x20000 /* UNUSED listen queue overflow */
+#define TF_LOCAL 0x20000 /* connection to a host on local link */
#define TF_RXWIN0SENT 0x40000 /* sent a receiver win 0 in response */
#define TF_SLOWLINK 0x80000 /* route is a on a modem speed link */
-
-
#define TF_LASTIDLE 0x100000 /* connection was previously idle */
#define TF_FASTRECOVERY 0x200000 /* in NewReno Fast Recovery */
#define TF_WASFRECOVERY 0x400000 /* was in NewReno Fast Recovery */
#define TF_CLOSING 0x8000000 /* pending tcp close */
#define TF_TSO 0x10000000 /* TCP Segment Offloading is enable on this connection */
#define TF_BLACKHOLE 0x20000000 /* Path MTU Discovery Black Hole detection */
+#define TF_TIMER_ONLIST 0x40000000 /* pcb is on tcp_timer_list */
+#define TF_STRETCHACK 0x80000000 /* receiver is going to delay acks */
int t_force; /* 1 if forcing out a byte */
* for slow start exponential to
* linear switch
*/
- u_int32_t snd_bandwidth; /* calculated bandwidth or 0 */
+ u_int32_t snd_bandwidth; /* calculated bandwidth or 0 */
tcp_seq snd_recover; /* for use in NewReno Fast Recovery */
u_int t_maxopd; /* mss plus options */
- u_int32_t t_rcvtime; /* inactivity time */
- u_int32_t t_starttime; /* time connection was established */
- int t_rtttime; /* round trip time */
+ u_int32_t t_rcvtime; /* time at which a packet was received */
+ u_int32_t t_starttime; /* time connection was established */
+ int t_rtttime; /* tcp clock when rtt calculation was started */
tcp_seq t_rtseq; /* sequence number being timed */
int t_bw_rtttime; /* used for bandwidth calculation */
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_int t_rttcur; /* most recent value of rtt */
u_int32_t t_rttupdated; /* number of times rtt sampled */
+ u_int32_t rxt_conndroptime; /* retxmt conn gets dropped after this time, when set */
+ u_int32_t rxt_start; /* time at a connection starts retransmitting */
u_int32_t max_sndwnd; /* largest window peer has offered */
int t_softerror; /* possible error not yet reported */
u_char rcv_scale; /* window scaling for recv window */
u_char request_r_scale; /* pending window scaling */
u_char requested_s_scale;
+ u_int16_t tcp_cc_index; /* index of congestion control algorithm */
u_int32_t ts_recent; /* timestamp echo data */
u_int32_t ts_recent_age; /* when last updated */
int t_keepidle; /* keepalive idle timer (override global if > 0) */
int t_lastchain; /* amount of packets chained last time around */
int t_unacksegs; /* received but unacked segments: used for delaying acks */
+ u_int32_t t_persist_timeout; /* ZWP persistence limit as set by PERSIST_TIMEOUT */
+ u_int32_t t_persist_stop; /* persistence limit deadline if triggered by ZWP */
/* 3529618 MSS overload prevention */
u_int32_t rcv_reset;
u_int32_t rcv_pps;
u_int32_t rcv_byps;
- u_int32_t rcv_maxbyps;
+ u_int32_t rcv_maxbyps;
+
+/* Receiver state for stretch-ack algorithm */
+ u_int32_t rcv_unackwin; /* to measure win for stretching acks */
+ u_int32_t rcv_by_unackwin; /* bytes seen during the last ack-stretching win */
+ u_int16_t rcv_waitforss; /* wait for packets during slow-start */
+ u_int16_t ecn_flags;
+#define TE_SETUPSENT 0x01 /* Indicate we have sent ECN-SETUP SYN or SYN-ACK */
+#define TE_SETUPRECEIVED 0x02 /* Indicate we have received ECN-SETUP SYN or SYN-ACK */
+#define TE_SENDIPECT 0x04 /* Indicate we haven't sent or received non-ECN-setup SYN or SYN-ACK */
+#define TE_SENDCWR 0x08 /* Indicate that the next non-retransmit should have the TCP CWR flag set */
+#define TE_SENDECE 0x10 /* Indicate that the next packet should have the TCP ECE flag set */
tcp_seq snd_high; /* for use in NewReno Fast Recovery */
tcp_seq snd_high_prev; /* snd_high prior to retransmit */
-
tcp_seq snd_recover_prev; /* snd_recover prior to retransmit */
u_char snd_limited; /* segments limited transmitted */
/* anti DoS counters */
u_int32_t rcv_second; /* start of interval second */
+
/* SACK related state */
int sack_enable; /* enable SACK for this connection */
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*/
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_long ecn_flags;
-#define TE_SETUPSENT 0x01 /* Indicate we have sent ECN-SETUP SYN or SYN-ACK */
-#define TE_SETUPRECEIVED 0x02 /* Indicate we have received ECN-SETUP SYN or SYN-ACK */
-#define TE_SENDIPECT 0x04 /* Indicate we haven't sent or received non-ECN-setup SYN or SYN-ACK */
-#define TE_SENDCWR 0x08 /* Indicate that the next non-retransmit should have the TCP CWR flag set */
-#define TE_SENDECE 0x10 /* Indicate that the next packet should have the TCP ECE flag set */
-#if TRAFFIC_MGT
- u_int32_t tot_recv_snapshot; /* snapshot of global total pkts received */
- u_int32_t bg_recv_snapshot; /* snapshot of global background pkts received */
-#endif /* TRAFFIC_MGT */
u_int32_t t_pktlist_sentlen; /* total bytes in transmit chain */
struct mbuf *t_pktlist_head; /* First packet in transmit chain */
struct mbuf *t_pktlist_tail; /* Last packet in transmit chain */
int t_keepinit; /* connection timeout, i.e. idle time in SYN_SENT or SYN_RECV state */
u_int32_t tso_max_segment_size; /* TCP Segment Offloading maximum segment unit for NIC */
u_int t_pmtud_saved_maxopd; /* MSS saved before performing PMTU-D BlackHole detection */
+
+ struct
+ {
+ u_int32_t rxduplicatebytes;
+ u_int32_t rxoutoforderbytes;
+ u_int32_t txretransmitbytes;
+ u_int32_t unused_pad_to_8;
+ } t_stat;
+
+ /* Background congestion related state */
+ uint32_t rtt_hist[N_RTT_BASE]; /* history of minimum RTT */
+ uint32_t rtt_count; /* Number of RTT samples in recent base history */
+ uint32_t bg_ssthresh; /* Slow start threshold until delay increases */
+ uint32_t t_flagsext; /* Another field to accommodate more flags */
+#define TF_RXTFINDROP 0x1 /* Drop conn after retransmitting FIN 3 times */
+#define TF_RCVUNACK_WAITSS 0x2 /* set when the receiver should not stretch acks */
+
+#if TRAFFIC_MGT
+ /* Inter-arrival jitter related state */
+ uint32_t iaj_rcv_ts; /* tcp clock when the first packet was received */
+ uint16_t iaj_size; /* Size of packet for iaj measurement */
+ uint16_t iaj_small_pkt; /* Count of packets smaller than iaj_size */
+ uint16_t iaj_pktcnt; /* packet count, to avoid throttling initially */
+ uint16_t acc_iaj; /* Accumulated iaj */
+ tcp_seq iaj_rwintop; /* recent max advertised window */
+ uint32_t avg_iaj; /* Mean */
+ uint32_t std_dev_iaj; /* Standard deviation */
+#endif /* TRAFFIC_MGT */
};
#define IN_FASTRECOVERY(tp) (tp->t_flags & TF_FASTRECOVERY)
#define ENTER_FASTRECOVERY(tp) tp->t_flags |= TF_FASTRECOVERY
#define EXIT_FASTRECOVERY(tp) tp->t_flags &= ~TF_FASTRECOVERY
+#if CONFIG_DTRACE
+enum tcp_cc_event {
+ TCP_CC_CWND_INIT,
+ TCP_CC_INSEQ_ACK_RCVD,
+ TCP_CC_ACK_RCVD,
+ TCP_CC_ENTER_FASTRECOVERY,
+ TCP_CC_IN_FASTRECOVERY,
+ TCP_CC_EXIT_FASTRECOVERY,
+ TCP_CC_PARTIAL_ACK,
+ TCP_CC_IDLE_TIMEOUT,
+ TCP_CC_REXMT_TIMEOUT,
+ TCP_CC_ECN_RCVD,
+ TCP_CC_BAD_REXMT_RECOVERY,
+ TCP_CC_OUTPUT_ERROR,
+ TCP_CC_CHANGE_ALGO
+};
+#endif /* CONFIG_DTRACE */
/*
* Structure to hold TCP options that are only used during segment
#define sototcpcb(so) (intotcpcb(sotoinpcb(so)))
/*
- * The smoothed round-trip time and estimated variance
+ * The rtt measured is in milliseconds as the timestamp granularity is
+ * a millisecond. 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
+ * With these scales, srtt has 5 bits to the right of the binary point,
+ * and thus an "ALPHA" of 0.875. rttvar has 4 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_RTT_SHIFT 5 /* shift for srtt; 5 bits frac. */
+#define TCP_RTTVAR_SCALE 16 /* multiplier for rttvar; 4 bits */
+#define TCP_RTTVAR_SHIFT 4 /* shift for rttvar; 4 bits */
#define TCP_DELTA_SHIFT 2 /* see tcp_input.c */
/*
int t_dupacks; /* consecutive dup acks recd */
u_int32_t unused; /* unused now: was t_template */
- int t_timer[TCPT_NTIMERS]; /* tcp timers */
+ int t_timer[TCPT_NTIMERS_EXT]; /* tcp timers */
_TCPCB_PTR(struct inpcb *) t_inpcb; /* back pointer to internet pcb */
int t_state; /* state of this connection */
*/
u_int t_maxopd; /* mss plus options */
- u_int32_t t_rcvtime; /* inactivity time */
+ u_int32_t t_rcvtime; /* time at which a packet was received */
u_int32_t t_starttime; /* time connection was established */
int t_rtttime; /* round trip time */
tcp_seq t_rtseq; /* sequence number being timed */
u_int32_t tcps_sack_send_blocks; /* SACK blocks (options) sent */
u_int32_t tcps_sack_sboverflow; /* SACK sendblock overflow */
-#if TRAFFIC_MGT
u_int32_t tcps_bg_rcvtotal; /* total background packets received */
-#endif /* TRAFFIC_MGT */
+ u_int32_t tcps_rxtfindrop; /* drop conn after retransmitting FIN */
};
#pragma pack(4)
u_int64_t t_segq;
int t_dupacks; /* consecutive dup acks recd */
- int t_timer[TCPT_NTIMERS]; /* tcp timers */
+ int t_timer[TCPT_NTIMERS_EXT]; /* tcp timers */
int t_state; /* state of this connection */
u_int t_flags;
*/
u_int t_maxopd; /* mss plus options */
- u_int32_t t_rcvtime; /* inactivity time */
+ u_int32_t t_rcvtime; /* time at which a packet was received */
u_int32_t t_starttime; /* time connection was established */
int t_rtttime; /* round trip time */
tcp_seq t_rtseq; /* sequence number being timed */
#endif /* !CONFIG_EMBEDDED */
+#ifdef PRIVATE
+
+struct xtcpcb_n {
+ u_int32_t xt_len;
+ u_int32_t xt_kind; /* XSO_TCPCB */
+
+ u_int64_t t_segq;
+ int t_dupacks; /* consecutive dup acks recd */
+
+ int t_timer[TCPT_NTIMERS_EXT]; /* tcp timers */
+
+ int t_state; /* state of this connection */
+ u_int t_flags;
+
+ int t_force; /* 1 if forcing out a byte */
+
+ 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_int32_t rcv_wnd; /* receive window */
+ tcp_seq rcv_up; /* receive urgent pointer */
+
+ u_int32_t snd_wnd; /* send window */
+ u_int32_t snd_cwnd; /* congestion-controlled window */
+ u_int32_t snd_ssthresh; /* snd_cwnd size threshold for
+ * for slow start exponential to
+ * linear switch
+ */
+ u_int t_maxopd; /* mss plus options */
+
+ u_int32_t t_rcvtime; /* time at which a packet was received */
+ u_int32_t t_starttime; /* time connection was established */
+ int t_rtttime; /* round trip time */
+ tcp_seq t_rtseq; /* sequence number being timed */
+
+ 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_int32_t t_rttupdated; /* number of times rtt sampled */
+ u_int32_t 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_char requested_s_scale;
+ u_int32_t ts_recent; /* timestamp echo data */
+
+ u_int32_t ts_recent_age; /* when last updated */
+ tcp_seq last_ack_sent;
+ /* RFC 1644 variables */
+ tcp_cc cc_send; /* send connection count */
+ tcp_cc cc_recv; /* receive connection count */
+ tcp_seq snd_recover; /* for use in fast recovery */
+ /* experimental */
+ u_int32_t snd_cwnd_prev; /* cwnd prior to retransmit */
+ u_int32_t snd_ssthresh_prev; /* ssthresh prior to retransmit */
+ u_int32_t t_badrxtwin; /* window for retransmit recovery */
+};
+
+#endif /* PRIVATE */
+
#pragma pack()
/*
extern int tcp_mssdflt; /* XXX */
extern int tcp_minmss;
extern int tcp_minmssoverload;
-extern int tcp_do_newreno;
extern int ss_fltsz;
extern int ss_fltsz_local;
+extern int tcp_do_rfc3390; /* Calculate ss_fltsz according to RFC 3390 */
#ifdef __APPLE__
extern u_int32_t tcp_now; /* for RFC 1323 timestamps */
+extern struct timeval tcp_uptime;
+extern lck_spin_t *tcp_uptime_lock;
+
extern int tcp_delack_enabled;
#endif /* __APPLE__ */
struct tcpcb *
tcp_drop(struct tcpcb *, int);
void tcp_drain(void);
-void tcp_fasttimo(void *);
struct rmxp_tao *
tcp_gettaocache(struct inpcb *);
void tcp_init(void) __attribute__((section("__TEXT, initcode")));
int tcp_output(struct tcpcb *);
void tcp_respond(struct tcpcb *, void *,
struct tcphdr *, struct mbuf *, tcp_seq, tcp_seq, int,
- unsigned int);
+ unsigned int, unsigned int);
struct rtentry *tcp_rtlookup(struct inpcb *, unsigned int);
void tcp_setpersist(struct tcpcb *);
void tcp_slowtimo(void);
+void tcp_check_timer_state(struct tcpcb *tp);
+void tcp_run_timerlist(void *arg1, void *arg2);
+
struct tcptemp *
tcp_maketemplate(struct tcpcb *);
void tcp_fillheaders(struct tcpcb *, void *, void *);
void tcp_free_sackholes(struct tcpcb *tp);
int32_t tcp_sbspace(struct tcpcb *tp);
void tcp_set_tso(struct tcpcb *tp, struct ifnet *ifp);
+void tcp_reset_stretch_ack(struct tcpcb *tp);
+#if TRAFFIC_MGT
+void reset_acc_iaj(struct tcpcb *tp);
+#endif /* TRAFFIC_MGT */
int tcp_lock (struct socket *, int, void *);
int tcp_unlock (struct socket *, int, void *);
+void calculate_tcp_clock(void);
+
#ifdef _KERN_LOCKS_H_
lck_mtx_t * tcp_getlock (struct socket *, int);
#else
projects / apple / xnu.git / blobdiff