diff --git a/sys/netinet/tcp_var.h b/sys/netinet/tcp_var.h index 5632e5d8bb41..f80e9fc37ff4 100644 --- a/sys/netinet/tcp_var.h +++ b/sys/netinet/tcp_var.h @@ -1,1587 +1,1587 @@ /*- * SPDX-License-Identifier: BSD-3-Clause * * 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. * 3. 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 #include #ifdef _KERNEL #include "opt_kern_tls.h" #include #include #include #endif #define TCP_END_BYTE_INFO 8 /* Bytes that makeup the "end information array" */ /* Types of ending byte info */ #define TCP_EI_EMPTY_SLOT 0 #define TCP_EI_STATUS_CLIENT_FIN 0x1 #define TCP_EI_STATUS_CLIENT_RST 0x2 #define TCP_EI_STATUS_SERVER_FIN 0x3 #define TCP_EI_STATUS_SERVER_RST 0x4 #define TCP_EI_STATUS_RETRAN 0x5 #define TCP_EI_STATUS_PROGRESS 0x6 #define TCP_EI_STATUS_PERSIST_MAX 0x7 #define TCP_EI_STATUS_KEEP_MAX 0x8 #define TCP_EI_STATUS_DATA_A_CLOSE 0x9 #define TCP_EI_STATUS_RST_IN_FRONT 0xa #define TCP_EI_STATUS_2MSL 0xb #define TCP_EI_STATUS_MAX_VALUE 0xb #define TCP_HTTP_REQ_LOG_NEW 0x01 #define TCP_HTTP_REQ_LOG_COMPLETE 0x02 #define TCP_HTTP_REQ_LOG_FREED 0x03 #define TCP_HTTP_REQ_LOG_ALLOCFAIL 0x04 #define TCP_HTTP_REQ_LOG_MOREYET 0x05 #define TCP_HTTP_REQ_LOG_FORCEFREE 0x06 #define TCP_HTTP_REQ_LOG_STALE 0x07 #define TCP_HTTP_REQ_LOG_SEARCH 0x08 /************************************************/ /* Status bits we track to assure no duplicates, * the bits here are not used by the code but * for human representation. To check a bit we * take and shift over by 1 minus the value (1-8). */ /************************************************/ #define TCP_EI_BITS_CLIENT_FIN 0x001 #define TCP_EI_BITS_CLIENT_RST 0x002 #define TCP_EI_BITS_SERVER_FIN 0x004 #define TCP_EI_BITS_SERVER_RST 0x008 #define TCP_EI_BITS_RETRAN 0x010 #define TCP_EI_BITS_PROGRESS 0x020 #define TCP_EI_BITS_PRESIST_MAX 0x040 #define TCP_EI_BITS_KEEP_MAX 0x080 #define TCP_EI_BITS_DATA_A_CLO 0x100 #define TCP_EI_BITS_RST_IN_FR 0x200 /* a front state reset */ #define TCP_EI_BITS_2MS_TIMER 0x400 /* 2 MSL timer expired */ #if defined(_KERNEL) || defined(_WANT_TCPCB) #include /* TCP segment queue entry */ struct tseg_qent { TAILQ_ENTRY(tseg_qent) tqe_q; struct mbuf *tqe_m; /* mbuf contains packet */ struct mbuf *tqe_last; /* last mbuf in chain */ tcp_seq tqe_start; /* TCP Sequence number start */ int tqe_len; /* TCP segment data length */ uint32_t tqe_flags; /* The flags from tcp_get_flags() */ uint32_t tqe_mbuf_cnt; /* Count of mbuf overhead */ }; TAILQ_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; int32_t sack_bytes_rexmit; tcp_seq last_sack_ack; /* Most recent/largest sacked ack */ int32_t delivered_data; /* Newly acked data from last SACK */ int32_t sacked_bytes; /* Total sacked bytes reported by the * receiver via sack option */ uint32_t recover_fs; /* Flight Size at the start of Loss recovery */ uint32_t prr_delivered; /* Total bytes delivered using PRR */ uint32_t prr_out; /* Bytes sent during IN_RECOVERY */ }; #define SEGQ_EMPTY(tp) TAILQ_EMPTY(&(tp)->t_segq) STAILQ_HEAD(tcp_log_stailq, tcp_log_mem); #define TCP_HTTP_TRACK_FLG_EMPTY 0x00 /* Available */ #define TCP_HTTP_TRACK_FLG_USED 0x01 /* In use */ #define TCP_HTTP_TRACK_FLG_OPEN 0x02 /* End is not valid (open range request) */ #define TCP_HTTP_TRACK_FLG_SEQV 0x04 /* We had a sendfile that touched it */ #define TCP_HTTP_TRACK_FLG_COMP 0x08 /* Sendfile as placed the last bits (range req only) */ #define TCP_HTTP_TRACK_FLG_FSND 0x10 /* First send has been done into the seq space */ #define MAX_TCP_HTTP_REQ 5 /* Max we will have at once */ #ifdef TCP_REQUEST_TRK struct http_sendfile_track { uint64_t timestamp; /* User sent timestamp */ uint64_t start; /* Start of sendfile offset */ uint64_t end; /* End if not open-range req */ uint64_t localtime; /* Time we actually got the req */ uint64_t deadline; /* If in CU mode, deadline to delivery */ uint64_t first_send; /* Time of first send in the range */ uint64_t cspr; /* Client suggested pace rate */ uint64_t sent_at_fs; /* What was t_sndbytes as we begun sending */ uint64_t rxt_at_fs; /* What was t_snd_rxt_bytes as we begun sending */ tcp_seq start_seq; /* First TCP Seq assigned */ tcp_seq end_seq; /* If range req last seq */ uint32_t flags; /* Type of request open etc */ uint32_t sbcc_at_s; /* When we allocate what is the sb_cc */ uint32_t hint_maxseg; /* Client hinted maxseg */ uint32_t hybrid_flags; /* Hybrid flags on this request */ }; #endif /* * Change Query responses for a stack switch we create a structure * that allows query response from the new stack to the old, if * supported. * * There are three queries currently defined. * - sendmap * - timers * - rack_times * * For the sendmap query the caller fills in the * req and the req_param as the first seq (usually * snd_una). When the response comes back indicating * that there was data (return value 1), then the caller * can build a sendmap entry based on the range and the * times. The next query would then be done at the * newly created sendmap_end. Repeated until sendmap_end == snd_max. * * Flags in sendmap_flags are defined below as well. * * For timers the standard PACE_TMR_XXXX flags are returned indicating * a pacing timer (possibly) and one other timer. If pacing timer then * the expiration timeout time in microseconds is in timer_pacing_to. * And the value used with whatever timer (if a flag is set) is in * timer_rxt. If no timers are running a 0 is returned and of * course no flags are set in timer_hpts_flags. * * The rack_times are a misc collection of information that * the old stack might possibly fill in. Of course its possible * that an old stack may not have a piece of information. If so * then setting that value to zero is advised. Setting any * timestamp passed should only place a zero in it when it * is unfilled. This may mean that a time is off by a micro-second * but this is ok in the grand scheme of things. * * When switching stacks it is desireable to get as much information * from the old stack to the new stack as possible. Though not always * will the stack be compatible in the types of information. The * init() function needs to take care when it begins changing * things such as inp_flags2 and the timer units to position these * changes at a point where it is unlikely they will fail after * making such changes. A stack optionally can have an "undo" * function * * To transfer information to the old stack from the new in * respect to LRO and the inp_flags2, the new stack should set * the inp_flags2 to what it supports. The old stack in its * fini() function should call the tcp_handle_orphaned_packets() * to clean up any packets. Note that a new stack should attempt */ /* Query types */ #define TCP_QUERY_SENDMAP 1 #define TCP_QUERY_TIMERS_UP 2 #define TCP_QUERY_RACK_TIMES 3 /* Flags returned in sendmap_flags */ #define SNDMAP_ACKED 0x000001/* The remote endpoint acked this */ #define SNDMAP_OVERMAX 0x000008/* We have more retran's then we can fit */ #define SNDMAP_SACK_PASSED 0x000010/* A sack was done above this block */ #define SNDMAP_HAS_FIN 0x000040/* segment is sent with fin */ #define SNDMAP_TLP 0x000080/* segment sent as tail-loss-probe */ #define SNDMAP_HAS_SYN 0x000800/* SYN is on this guy */ #define SNDMAP_HAD_PUSH 0x008000/* Push was sent on original send */ #define SNDMAP_MASK (SNDMAP_ACKED|SNDMAP_OVERMAX|SNDMAP_SACK_PASSED|SNDMAP_HAS_FIN\ |SNDMAP_TLP|SNDMAP_HAS_SYN|SNDMAP_HAD_PUSH) #define SNDMAP_NRTX 3 struct tcp_query_resp { int req; uint32_t req_param; union { struct { tcp_seq sendmap_start; tcp_seq sendmap_end; int sendmap_send_cnt; uint64_t sendmap_time[SNDMAP_NRTX]; uint64_t sendmap_ack_arrival; int sendmap_flags; uint32_t sendmap_r_rtr_bytes; /* If FAS is available if not 0 */ uint32_t sendmap_fas; uint8_t sendmap_dupacks; }; struct { uint32_t timer_hpts_flags; uint32_t timer_pacing_to; uint32_t timer_timer_exp; }; struct { /* Timestamps and rtt's */ uint32_t rack_reorder_ts; /* Last uscts that reordering was seen */ uint32_t rack_num_dsacks; /* Num of dsacks seen */ uint32_t rack_rxt_last_time; /* Last time a RXT/TLP or rack tmr went off */ uint32_t rack_min_rtt; /* never 0 smallest rtt seen */ uint32_t rack_rtt; /* Last rtt used by rack */ uint32_t rack_tmit_time; /* The time the rtt seg was tmited */ uint32_t rack_time_went_idle; /* If in persist the time we went idle */ /* Prr data */ uint32_t rack_sacked; uint32_t rack_holes_rxt; uint32_t rack_prr_delivered; uint32_t rack_prr_recovery_fs; uint32_t rack_prr_out; uint32_t rack_prr_sndcnt; /* TLP data */ uint16_t rack_tlp_cnt_out; /* How many tlp's have been sent */ /* Various bits */ uint8_t rack_tlp_out; /* Is a TLP outstanding */ uint8_t rack_srtt_measured; /* The previous stack has measured srtt */ uint8_t rack_in_persist; /* Is the old stack in persists? */ uint8_t rack_wanted_output; /* Did the prevous stack have a want output set */ }; }; }; #define TCP_TMR_GRANULARITY_TICKS 1 /* TCP timers are in ticks (msec if hz=1000) */ #define TCP_TMR_GRANULARITY_USEC 2 /* TCP timers are in microseconds */ typedef enum { TT_REXMT = 0, TT_PERSIST, TT_KEEP, TT_2MSL, TT_DELACK, TT_N, } tt_which; typedef enum { TT_PROCESSING = 0, TT_PROCESSED, TT_STARTING, TT_STOPPING, } tt_what; /* * Tcp control block, one per tcp connection. */ struct tcpcb { struct inpcb t_inpcb; /* embedded protocol independent cb */ #define t_start_zero t_fb #define t_zero_size (sizeof(struct tcpcb) - \ offsetof(struct tcpcb, t_start_zero)) struct tcp_function_block *t_fb;/* TCP function call block */ void *t_fb_ptr; /* Pointer to t_fb specific data */ struct callout t_callout; sbintime_t t_timers[TT_N]; sbintime_t t_precisions[TT_N]; uint32_t t_maxseg:24, /* maximum segment size */ _t_logstate:8; /* State of "black box" logging */ uint32_t t_port:16, /* Tunneling (over udp) port */ t_state:4, /* state of this connection */ t_idle_reduce : 1, t_delayed_ack: 7, /* Delayed ack variable */ t_fin_is_rst: 1, /* Are fin's treated as resets */ t_log_state_set: 1, bits_spare : 2; u_int t_flags; tcp_seq snd_una; /* sent but 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 */ uint32_t snd_wnd; /* send window */ uint32_t snd_cwnd; /* congestion-controlled window */ uint32_t ts_offset; /* our timestamp offset */ uint32_t rfbuf_ts; /* recv buffer autoscaling timestamp */ int rcv_numsacks; /* # distinct sack blks present */ u_int t_tsomax; /* TSO total burst length limit */ u_int t_tsomaxsegcount; /* TSO maximum segment count */ u_int t_tsomaxsegsize; /* TSO maximum segment size in bytes */ tcp_seq rcv_nxt; /* receive next */ tcp_seq rcv_adv; /* advertised window */ uint32_t rcv_wnd; /* receive window */ u_int t_flags2; /* More tcpcb flags storage */ int t_srtt; /* smoothed round-trip time */ int t_rttvar; /* variance in round-trip time */ uint32_t ts_recent; /* timestamp echo data */ u_char snd_scale; /* window scaling for send window */ u_char rcv_scale; /* window scaling for recv window */ u_char snd_limited; /* segments limited transmitted */ u_char request_r_scale; /* pending window scaling */ tcp_seq last_ack_sent; u_int t_rcvtime; /* inactivity time */ tcp_seq rcv_up; /* receive urgent pointer */ int t_segqlen; /* segment reassembly queue length */ uint32_t t_segqmbuflen; /* total reassembly queue byte length */ struct tsegqe_head t_segq; /* segment reassembly queue */ STAILQ_HEAD(, mbuf) t_inqueue; /* HPTS input queue */ uint32_t snd_ssthresh; /* snd_cwnd size threshold for * for slow start exponential to * linear switch */ tcp_seq snd_wl1; /* window update seg seq number */ tcp_seq snd_wl2; /* window update seg ack number */ tcp_seq irs; /* initial receive sequence number */ tcp_seq iss; /* initial send sequence number */ u_int t_acktime; /* RACK and BBR incoming new data was acked */ u_int t_sndtime; /* time last data was sent */ u_int ts_recent_age; /* when last updated */ tcp_seq snd_recover; /* for use in NewReno Fast Recovery */ char t_oobflags; /* have some */ char t_iobc; /* input character */ uint8_t t_nic_ktls_xmit:1, /* active nic ktls xmit sessions */ t_nic_ktls_xmit_dis:1, /* disabled nic xmit ktls? */ t_nic_ktls_spare:6; /* spare nic ktls */ int t_rxtcur; /* current retransmit value (ticks) */ int t_rxtshift; /* log(2) of rexmt exp. backoff */ u_int t_rtttime; /* RTT measurement start time */ tcp_seq t_rtseq; /* sequence number being timed */ u_int t_starttime; /* time connection was established */ u_int t_fbyte_in; /* ticks time first byte queued in */ u_int t_fbyte_out; /* ticks time first byte queued out */ u_int t_pmtud_saved_maxseg; /* pre-blackhole MSS */ int t_blackhole_enter; /* when to enter blackhole detection */ int t_blackhole_exit; /* when to exit blackhole detection */ u_int t_rttmin; /* minimum rtt allowed */ int t_softerror; /* possible error not yet reported */ uint32_t max_sndwnd; /* largest window peer has offered */ uint32_t snd_cwnd_prev; /* cwnd prior to retransmit */ uint32_t snd_ssthresh_prev; /* ssthresh prior to retransmit */ tcp_seq snd_recover_prev; /* snd_recover prior to retransmit */ int t_sndzerowin; /* zero-window updates sent */ int snd_numholes; /* number of holes seen by sender */ u_int t_badrxtwin; /* window for retransmit recovery */ TAILQ_HEAD(sackhole_head, sackhole) snd_holes; /* SACK scoreboard (sorted) */ tcp_seq snd_fack; /* last seq number(+1) sack'd by rcv'r*/ struct sackblk sackblks[MAX_SACK_BLKS]; /* seq nos. of sack blocks */ struct sackhint sackhint; /* SACK scoreboard hint */ int t_rttlow; /* smallest observerved RTT */ int rfbuf_cnt; /* recv buffer autoscaling byte count */ struct toedev *tod; /* toedev handling this connection */ int t_sndrexmitpack; /* retransmit packets sent */ int t_rcvoopack; /* out-of-order packets received */ void *t_toe; /* TOE pcb pointer */ struct cc_algo *t_cc; /* congestion control algorithm */ struct cc_var t_ccv; /* congestion control specific vars */ int t_bytes_acked; /* # bytes acked during current RTT */ u_int t_maxunacktime; u_int t_keepinit; /* time to establish connection */ u_int t_keepidle; /* time before keepalive probes begin */ u_int t_keepintvl; /* interval between keepalives */ u_int t_keepcnt; /* number of keepalives before close */ int t_dupacks; /* consecutive dup acks recd */ int t_lognum; /* Number of log entries */ int t_loglimit; /* Maximum number of log entries */ uint32_t t_rcep; /* Number of received CE marked pkts */ uint32_t t_scep; /* Synced number of delivered CE pkts */ int64_t t_pacing_rate; /* bytes / sec, -1 => unlimited */ struct tcp_log_stailq t_logs; /* Log buffer */ struct tcp_log_id_node *t_lin; struct tcp_log_id_bucket *t_lib; const char *t_output_caller; /* Function that called tcp_output */ struct statsblob *t_stats; /* Per-connection stats */ /* Should these be a pointer to the arrays or an array? */ #ifdef TCP_ACCOUNTING uint64_t tcp_cnt_counters[TCP_NUM_CNT_COUNTERS]; uint64_t tcp_proc_time[TCP_NUM_CNT_COUNTERS]; #endif #ifdef TCP_REQUEST_TRK uint32_t tcp_hybrid_start; /* Num of times we started hybrid pacing */ uint32_t tcp_hybrid_stop; /* Num of times we stopped hybrid pacing */ uint32_t tcp_hybrid_error; /* Num of times we failed to start hybrid pacing */ #endif uint32_t t_logsn; /* Log "serial number" */ uint32_t gput_ts; /* Time goodput measurement started */ tcp_seq gput_seq; /* Outbound measurement seq */ tcp_seq gput_ack; /* Inbound measurement ack */ int32_t t_stats_gput_prev; /* XXXLAS: Prev gput measurement */ uint32_t t_maxpeakrate; /* max peak rate set by user, bytes/s */ uint32_t t_sndtlppack; /* tail loss probe packets sent */ uint64_t t_sndtlpbyte; /* total tail loss probe bytes sent */ uint64_t t_sndbytes; /* total bytes sent */ uint64_t t_snd_rxt_bytes; /* total bytes retransmitted */ uint32_t t_dsack_bytes; /* dsack bytes received */ uint32_t t_dsack_tlp_bytes; /* dsack bytes received for TLPs sent */ uint32_t t_dsack_pack; /* dsack packets we have eceived */ uint8_t t_tmr_granularity; /* Granularity of all timers srtt etc */ uint8_t t_rttupdated; /* number of times rtt sampled */ /* TCP Fast Open */ uint8_t t_tfo_client_cookie_len; /* TFO client cookie length */ uint32_t t_end_info_status; /* Status flag of end info */ unsigned int *t_tfo_pending; /* TFO server pending counter */ union { uint8_t client[TCP_FASTOPEN_MAX_COOKIE_LEN]; uint64_t server; } t_tfo_cookie; /* TCP Fast Open cookie to send */ union { uint8_t t_end_info_bytes[TCP_END_BYTE_INFO]; uint64_t t_end_info; }; #ifdef TCPPCAP struct mbufq t_inpkts; /* List of saved input packets. */ struct mbufq t_outpkts; /* List of saved output packets. */ #endif #ifdef TCP_HHOOK struct osd t_osd; /* storage for Khelp module data */ #endif uint8_t _t_logpoint; /* Used when a BB log points is enabled */ #ifdef TCP_REQUEST_TRK /* Response tracking addons. */ uint8_t t_http_req; /* Request count */ uint8_t t_http_open; /* Number of open range requests */ uint8_t t_http_closed; /* Number of closed range requests */ struct http_sendfile_track t_http_info[MAX_TCP_HTTP_REQ]; #endif }; #endif /* _KERNEL || _WANT_TCPCB */ #ifdef _KERNEL struct tcptemp { u_char tt_ipgen[40]; /* the size must be of max ip header, now IPv6 */ struct tcphdr tt_t; }; /* Enable TCP/UDP tunneling port */ #define TCP_TUNNELING_PORT_MIN 0 #define TCP_TUNNELING_PORT_MAX 65535 #define TCP_TUNNELING_PORT_DEFAULT 0 /* Enable TCP/UDP tunneling port */ #define TCP_TUNNELING_OVERHEAD_MIN sizeof(struct udphdr) #define TCP_TUNNELING_OVERHEAD_MAX 1024 #define TCP_TUNNELING_OVERHEAD_DEFAULT TCP_TUNNELING_OVERHEAD_MIN /* Minimum map entries limit value, if set */ #define TCP_MIN_MAP_ENTRIES_LIMIT 128 /* * TODO: We yet need to brave plowing in * to tcp_input() and the pru_usrreq() block. * Right now these go to the old standards which * are somewhat ok, but in the long term may * need to be changed. If we do tackle tcp_input() * then we need to get rid of the tcp_do_segment() * function below. */ /* Flags for tcp functions */ #define TCP_FUNC_BEING_REMOVED 0x01 /* Can no longer be referenced */ #define TCP_FUNC_OUTPUT_CANDROP 0x02 /* tfb_tcp_output may ask tcp_drop */ /** * If defining the optional tcp_timers, in the * tfb_tcp_timer_stop call you must use the * callout_async_drain() function with the * tcp_timer_discard callback. You should check * the return of callout_async_drain() and if 0 * increment tt_draincnt. Since the timer sub-system * does not know your callbacks you must provide a * stop_all function that loops through and calls * tcp_timer_stop() with each of your defined timers. * * Adding a tfb_tcp_handoff_ok function allows the socket * option to change stacks to query you even if the * connection is in a later stage. You return 0 to * say you can take over and run your stack, you return * non-zero (an error number) to say no you can't. * If the function is undefined you can only change * in the early states (before connect or listen). * * tfb_tcp_fb_init is used to allow the new stack to * setup its control block. Among the things it must * do is: * a) Make sure that the inp_flags2 is setup correctly * for LRO. There are two flags that the previous * stack may have set INP_MBUF_ACKCMP and * INP_SUPPORTS_MBUFQ. If the new stack does not * support these it *should* clear the flags. * b) Make sure that the timers are in the proper * granularity that the stack wants. The stack * should check the t_tmr_granularity field. Currently * there are two values that it may hold * TCP_TMR_GRANULARITY_TICKS and TCP_TMR_GRANULARITY_USEC. * Use the functions tcp_timer_convert(tp, granularity); * to move the timers to the correct format for your stack. * * The new stack may also optionally query the tfb_chg_query * function if the old stack has one. The new stack may ask * for one of three entries and can also state to the old * stack its support for the INP_MBUF_ACKCMP and * INP_SUPPORTS_MBUFQ. This is important since if there are * queued ack's without that statement the old stack will * be forced to discard the queued acks. The requests that * can be made for information by the new stacks are: * * Note also that the tfb_tcp_fb_init() when called can * determine if a query is needed by looking at the * value passed in the ptr. The ptr is designed to be * set in with any allocated memory, but the address * of the condtion (ptr == &tp->t_fb_ptr) will be * true if this is not a stack switch but the initial * setup of a tcb (which means no query would be needed). * If, however, the value is not t_fb_ptr, then the caller * is in the middle of a stack switch and is the new stack. * A query would be appropriate (if the new stack support * the query mechanism). * * TCP_QUERY_SENDMAP - Query of outstanding data. * TCP_QUERY_TIMERS_UP - Query about running timers. * TCP_SUPPORTED_LRO - Declaration in req_param of * the inp_flags2 supported by * the new stack. * TCP_QUERY_RACK_TIMES - Enquire about various timestamps * and states the old stack may be in. * * tfb_tcp_fb_fini is changed to add a flag to tell * the old stack if the tcb is being destroyed or * not. A one in the flag means the TCB is being * destroyed, a zero indicates its transitioning to * another stack (via socket option). The * tfb_tcp_fb_fini() function itself should not change timers * or inp_flags2 (the tfb_tcp_fb_init() must do that). However * if the old stack supports the LRO mbuf queuing, and the new * stack does not communicate via chg messages that it too does, * it must assume it does not and free any queued mbufs. * */ struct tcp_function_block { char tfb_tcp_block_name[TCP_FUNCTION_NAME_LEN_MAX]; int (*tfb_tcp_output)(struct tcpcb *); void (*tfb_tcp_do_segment)(struct tcpcb *, struct mbuf *, struct tcphdr *, int, int, uint8_t); int (*tfb_do_segment_nounlock)(struct tcpcb *, struct mbuf *, struct tcphdr *, int, int, uint8_t, int, struct timeval *); int (*tfb_do_queued_segments)(struct tcpcb *, int); int (*tfb_tcp_ctloutput)(struct tcpcb *, struct sockopt *); /* Optional memory allocation/free routine */ int (*tfb_tcp_fb_init)(struct tcpcb *, void **); void (*tfb_tcp_fb_fini)(struct tcpcb *, int); /* Optional timers, must define all if you define one */ int (*tfb_tcp_timer_stop_all)(struct tcpcb *); void (*tfb_tcp_rexmit_tmr)(struct tcpcb *); int (*tfb_tcp_handoff_ok)(struct tcpcb *); void (*tfb_tcp_mtu_chg)(struct tcpcb *tp); int (*tfb_pru_options)(struct tcpcb *, int); void (*tfb_hwtls_change)(struct tcpcb *, int); int (*tfb_chg_query)(struct tcpcb *, struct tcp_query_resp *); void (*tfb_switch_failed)(struct tcpcb *); bool (*tfb_early_wake_check)(struct tcpcb *); int (*tfb_compute_pipe)(struct tcpcb *tp); volatile uint32_t tfb_refcnt; uint32_t tfb_flags; uint8_t tfb_id; }; struct tcp_function { TAILQ_ENTRY(tcp_function) tf_next; char tf_name[TCP_FUNCTION_NAME_LEN_MAX]; struct tcp_function_block *tf_fb; }; TAILQ_HEAD(tcp_funchead, tcp_function); struct tcpcb * tcp_drop(struct tcpcb *, int); #ifdef _NETINET_IN_PCB_H_ #define intotcpcb(inp) __containerof((inp), struct tcpcb, t_inpcb) #define sototcpcb(so) intotcpcb(sotoinpcb(so)) #define tptoinpcb(tp) (&(tp)->t_inpcb) #define tptosocket(tp) (tp)->t_inpcb.inp_socket /* * tcp_output() * Handles tcp_drop request from advanced stacks and reports that inpcb is * gone with negative return code. * Drop in replacement for the default stack. */ static inline int tcp_output(struct tcpcb *tp) { struct inpcb *inp = tptoinpcb(tp); int rv; INP_WLOCK_ASSERT(inp); rv = tp->t_fb->tfb_tcp_output(tp); if (rv < 0) { KASSERT(tp->t_fb->tfb_flags & TCP_FUNC_OUTPUT_CANDROP, ("TCP stack %s requested tcp_drop(%p)", tp->t_fb->tfb_tcp_block_name, tp)); tp = tcp_drop(tp, -rv); if (tp) INP_WUNLOCK(inp); } return (rv); } static inline void tcp_lro_features_off(struct inpcb *inp) { inp->inp_flags2 &= ~(INP_SUPPORTS_MBUFQ| INP_MBUF_QUEUE_READY| INP_DONT_SACK_QUEUE| INP_MBUF_ACKCMP| INP_MBUF_L_ACKS); } /* * tcp_output_unlock() * Always returns unlocked, handles drop request from advanced stacks. * Always returns positive error code. */ static inline int tcp_output_unlock(struct tcpcb *tp) { struct inpcb *inp = tptoinpcb(tp); int rv; INP_WLOCK_ASSERT(inp); rv = tp->t_fb->tfb_tcp_output(tp); if (rv < 0) { KASSERT(tp->t_fb->tfb_flags & TCP_FUNC_OUTPUT_CANDROP, ("TCP stack %s requested tcp_drop(%p)", tp->t_fb->tfb_tcp_block_name, tp)); rv = -rv; tp = tcp_drop(tp, rv); if (tp) INP_WUNLOCK(inp); } else INP_WUNLOCK(inp); return (rv); } /* * tcp_output_nodrop() * Always returns locked. It is caller's responsibility to run tcp_drop()! * Useful in syscall implementations, when we want to perform some logging * and/or tracing with tcpcb before calling tcp_drop(). To be used with * tcp_unlock_or_drop() later. * * XXXGL: maybe don't allow stacks to return a drop request at certain * TCP states? Why would it do in connect(2)? In recv(2)? */ static inline int tcp_output_nodrop(struct tcpcb *tp) { int rv; INP_WLOCK_ASSERT(tptoinpcb(tp)); rv = tp->t_fb->tfb_tcp_output(tp); KASSERT(rv >= 0 || tp->t_fb->tfb_flags & TCP_FUNC_OUTPUT_CANDROP, ("TCP stack %s requested tcp_drop(%p)", tp->t_fb->tfb_tcp_block_name, tp)); return (rv); } /* * tcp_unlock_or_drop() * Handle return code from tfb_tcp_output() after we have logged/traced, * to be used with tcp_output_nodrop(). */ static inline int tcp_unlock_or_drop(struct tcpcb *tp, int tcp_output_retval) { struct inpcb *inp = tptoinpcb(tp); INP_WLOCK_ASSERT(inp); if (tcp_output_retval < 0) { tcp_output_retval = -tcp_output_retval; if (tcp_drop(tp, tcp_output_retval) != NULL) INP_WUNLOCK(inp); } else INP_WUNLOCK(inp); return (tcp_output_retval); } #endif /* _NETINET_IN_PCB_H_ */ static int inline tcp_packets_this_ack(struct tcpcb *tp, tcp_seq ack) { return ((ack - tp->snd_una) / tp->t_maxseg + ((((ack - tp->snd_una) % tp->t_maxseg) != 0) ? 1 : 0)); } #endif /* _KERNEL */ /* * Flags and utility macros for the t_flags field. */ #define TF_ACKNOW 0x00000001 /* ack peer immediately */ #define TF_DELACK 0x00000002 /* ack, but try to delay it */ #define TF_NODELAY 0x00000004 /* don't delay packets to coalesce */ #define TF_NOOPT 0x00000008 /* don't use tcp options */ #define TF_SENTFIN 0x00000010 /* have sent FIN */ #define TF_REQ_SCALE 0x00000020 /* have/will request window scaling */ #define TF_RCVD_SCALE 0x00000040 /* other side has requested scaling */ #define TF_REQ_TSTMP 0x00000080 /* have/will request timestamps */ #define TF_RCVD_TSTMP 0x00000100 /* a timestamp was received in SYN */ #define TF_SACK_PERMIT 0x00000200 /* other side said I could SACK */ #define TF_NEEDSYN 0x00000400 /* send SYN (implicit state) */ #define TF_NEEDFIN 0x00000800 /* send FIN (implicit state) */ #define TF_NOPUSH 0x00001000 /* don't push */ #define TF_PREVVALID 0x00002000 /* saved values for bad rxmit valid * Note: accessing and restoring from * these may only be done in the 1st * RTO recovery round (t_rxtshift == 1) */ #define TF_WAKESOR 0x00004000 /* wake up receive socket */ #define TF_GPUTINPROG 0x00008000 /* Goodput measurement in progress */ #define TF_MORETOCOME 0x00010000 /* More data to be appended to sock */ #define TF_SONOTCONN 0x00020000 /* needs soisconnected() on ESTAB */ #define TF_LASTIDLE 0x00040000 /* connection was previously idle */ #define TF_RXWIN0SENT 0x00080000 /* sent a receiver win 0 in response */ #define TF_FASTRECOVERY 0x00100000 /* in NewReno Fast Recovery */ #define TF_WASFRECOVERY 0x00200000 /* was in NewReno Fast Recovery */ #define TF_SIGNATURE 0x00400000 /* require MD5 digests (RFC2385) */ #define TF_FORCEDATA 0x00800000 /* force out a byte */ #define TF_TSO 0x01000000 /* TSO enabled on this connection */ #define TF_TOE 0x02000000 /* this connection is offloaded */ #define TF_CLOSED 0x04000000 /* close(2) called on socket */ #define TF_UNUSED1 0x08000000 /* unused */ #define TF_LRD 0x10000000 /* Lost Retransmission Detection */ #define TF_CONGRECOVERY 0x20000000 /* congestion recovery mode */ #define TF_WASCRECOVERY 0x40000000 /* was in congestion recovery */ #define TF_FASTOPEN 0x80000000 /* TCP Fast Open indication */ #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) #if defined(_KERNEL) && !defined(TCP_RFC7413) #define IS_FASTOPEN(t_flags) (false) #else #define IS_FASTOPEN(t_flags) (t_flags & TF_FASTOPEN) #endif #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 /* * Flags for the extended TCP flags field, t_flags2 */ #define TF2_PLPMTU_BLACKHOLE 0x00000001 /* Possible PLPMTUD Black Hole. */ #define TF2_PLPMTU_PMTUD 0x00000002 /* Allowed to attempt PLPMTUD. */ #define TF2_PLPMTU_MAXSEGSNT 0x00000004 /* Last seg sent was full seg. */ #define TF2_LOG_AUTO 0x00000008 /* Session is auto-logging. */ #define TF2_DROP_AF_DATA 0x00000010 /* Drop after all data ack'd */ #define TF2_ECN_PERMIT 0x00000020 /* connection ECN-ready */ #define TF2_ECN_SND_CWR 0x00000040 /* ECN CWR in queue */ #define TF2_ECN_SND_ECE 0x00000080 /* ECN ECE in queue */ #define TF2_ACE_PERMIT 0x00000100 /* Accurate ECN mode */ #define TF2_FBYTES_COMPLETE 0x00000400 /* We have first bytes in and out */ #define TF2_ECN_USE_ECT1 0x00000800 /* Use ECT(1) marking on session */ -#define TF2_TCP_ACCOUNTING 0x00010000 /* Do TCP accounting */ +#define TF2_TCP_ACCOUNTING 0x00001000 /* Do TCP accounting */ /* * 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_int32_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_FASTOPEN 0x0100 /* TCP Fast Open (TFO) cookie */ #define TOF_MAXOPT 0x0200 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_int8_t *to_tfo_cookie; /* pointer to the TFO cookie */ u_int16_t to_mss; /* maximum segment size */ u_int8_t to_wscale; /* window scaling */ u_int8_t to_nsacks; /* number of SACK blocks */ u_int8_t to_tfo_len; /* TFO cookie length */ u_int32_t to_spare; /* UTO */ }; /* * Flags for tcp_dooptions. */ #define TO_SYN 0x01 /* parse SYN-only options */ struct hc_metrics_lite { /* must stay in sync with hc_metrics */ uint32_t rmx_mtu; /* MTU for this path */ uint32_t rmx_ssthresh; /* outbound gateway buffer limit */ uint32_t rmx_rtt; /* estimated round trip time */ uint32_t rmx_rttvar; /* estimated rtt variance */ uint32_t rmx_cwnd; /* congestion window */ uint32_t rmx_sendpipe; /* outbound delay-bandwidth product */ uint32_t rmx_recvpipe; /* inbound delay-bandwidth product */ }; /* * Used by tcp_maxmtu() to communicate interface specific features * and limits at the time of connection setup. */ struct tcp_ifcap { int ifcap; u_int tsomax; u_int tsomaxsegcount; u_int tsomaxsegsize; }; #ifndef _NETINET_IN_PCB_H_ struct in_conninfo; #endif /* _NETINET_IN_PCB_H_ */ /* * 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 { uint64_t tcps_connattempt; /* connections initiated */ uint64_t tcps_accepts; /* connections accepted */ uint64_t tcps_connects; /* connections established */ uint64_t tcps_drops; /* connections dropped */ uint64_t tcps_conndrops; /* embryonic connections dropped */ uint64_t tcps_minmssdrops; /* average minmss too low drops */ uint64_t tcps_closed; /* conn. closed (includes drops) */ uint64_t tcps_segstimed; /* segs where we tried to get rtt */ uint64_t tcps_rttupdated; /* times we succeeded */ uint64_t tcps_delack; /* delayed acks sent */ uint64_t tcps_timeoutdrop; /* conn. dropped in rxmt timeout */ uint64_t tcps_rexmttimeo; /* retransmit timeouts */ uint64_t tcps_persisttimeo; /* persist timeouts */ uint64_t tcps_keeptimeo; /* keepalive timeouts */ uint64_t tcps_keepprobe; /* keepalive probes sent */ uint64_t tcps_keepdrops; /* connections dropped in keepalive */ uint64_t tcps_progdrops; /* drops due to no progress */ uint64_t tcps_sndtotal; /* total packets sent */ uint64_t tcps_sndpack; /* data packets sent */ uint64_t tcps_sndbyte; /* data bytes sent */ uint64_t tcps_sndrexmitpack; /* data packets retransmitted */ uint64_t tcps_sndrexmitbyte; /* data bytes retransmitted */ uint64_t tcps_sndrexmitbad; /* unnecessary packet retransmissions */ uint64_t tcps_sndacks; /* ack-only packets sent */ uint64_t tcps_sndprobe; /* window probes sent */ uint64_t tcps_sndurg; /* packets sent with URG only */ uint64_t tcps_sndwinup; /* window update-only packets sent */ uint64_t tcps_sndctrl; /* control (SYN|FIN|RST) packets sent */ uint64_t tcps_rcvtotal; /* total packets received */ uint64_t tcps_rcvpack; /* packets received in sequence */ uint64_t tcps_rcvbyte; /* bytes received in sequence */ uint64_t tcps_rcvbadsum; /* packets received with ccksum errs */ uint64_t tcps_rcvbadoff; /* packets received with bad offset */ uint64_t tcps_rcvreassfull; /* packets dropped for no reass space */ uint64_t tcps_rcvshort; /* packets received too short */ uint64_t tcps_rcvduppack; /* duplicate-only packets received */ uint64_t tcps_rcvdupbyte; /* duplicate-only bytes received */ uint64_t tcps_rcvpartduppack; /* packets with some duplicate data */ uint64_t tcps_rcvpartdupbyte; /* dup. bytes in part-dup. packets */ uint64_t tcps_rcvoopack; /* out-of-order packets received */ uint64_t tcps_rcvoobyte; /* out-of-order bytes received */ uint64_t tcps_rcvpackafterwin; /* packets with data after window */ uint64_t tcps_rcvbyteafterwin; /* bytes rcvd after window */ uint64_t tcps_rcvafterclose; /* packets rcvd after "close" */ uint64_t tcps_rcvwinprobe; /* rcvd window probe packets */ uint64_t tcps_rcvdupack; /* rcvd duplicate acks */ uint64_t tcps_rcvacktoomuch; /* rcvd acks for unsent data */ uint64_t tcps_rcvackpack; /* rcvd ack packets */ uint64_t tcps_rcvackbyte; /* bytes acked by rcvd acks */ uint64_t tcps_rcvwinupd; /* rcvd window update packets */ uint64_t tcps_pawsdrop; /* segments dropped due to PAWS */ uint64_t tcps_predack; /* times hdr predict ok for acks */ uint64_t tcps_preddat; /* times hdr predict ok for data pkts */ uint64_t tcps_pcbcachemiss; uint64_t tcps_cachedrtt; /* times cached RTT in route updated */ uint64_t tcps_cachedrttvar; /* times cached rttvar updated */ uint64_t tcps_cachedssthresh; /* times cached ssthresh updated */ uint64_t tcps_usedrtt; /* times RTT initialized from route */ uint64_t tcps_usedrttvar; /* times RTTVAR initialized from rt */ uint64_t tcps_usedssthresh; /* times ssthresh initialized from rt*/ uint64_t tcps_persistdrop; /* timeout in persist state */ uint64_t tcps_badsyn; /* bogus SYN, e.g. premature ACK */ uint64_t tcps_mturesent; /* resends due to MTU discovery */ uint64_t tcps_listendrop; /* listen queue overflows */ uint64_t tcps_badrst; /* ignored RSTs in the window */ uint64_t tcps_sc_added; /* entry added to syncache */ uint64_t tcps_sc_retransmitted; /* syncache entry was retransmitted */ uint64_t tcps_sc_dupsyn; /* duplicate SYN packet */ uint64_t tcps_sc_dropped; /* could not reply to packet */ uint64_t tcps_sc_completed; /* successful extraction of entry */ uint64_t tcps_sc_bucketoverflow;/* syncache per-bucket limit hit */ uint64_t tcps_sc_cacheoverflow; /* syncache cache limit hit */ uint64_t tcps_sc_reset; /* RST removed entry from syncache */ uint64_t tcps_sc_stale; /* timed out or listen socket gone */ uint64_t tcps_sc_aborted; /* syncache entry aborted */ uint64_t tcps_sc_badack; /* removed due to bad ACK */ uint64_t tcps_sc_unreach; /* ICMP unreachable received */ uint64_t tcps_sc_zonefail; /* zalloc() failed */ uint64_t tcps_sc_sendcookie; /* SYN cookie sent */ uint64_t tcps_sc_recvcookie; /* SYN cookie received */ uint64_t tcps_hc_added; /* entry added to hostcache */ uint64_t tcps_hc_bucketoverflow;/* hostcache per bucket limit hit */ uint64_t tcps_finwait2_drops; /* Drop FIN_WAIT_2 connection after time limit */ /* SACK related stats */ uint64_t tcps_sack_recovery_episode; /* SACK recovery episodes */ uint64_t tcps_sack_rexmits; /* SACK rexmit segments */ uint64_t tcps_sack_rexmit_bytes; /* SACK rexmit bytes */ uint64_t tcps_sack_rcv_blocks; /* SACK blocks (options) received */ uint64_t tcps_sack_send_blocks; /* SACK blocks (options) sent */ uint64_t tcps_sack_lostrexmt; /* SACK lost retransmission recovered */ uint64_t tcps_sack_sboverflow; /* times scoreboard overflowed */ /* ECN related stats */ uint64_t tcps_ecn_rcvce; /* ECN Congestion Experienced */ uint64_t tcps_ecn_rcvect0; /* ECN Capable Transport */ uint64_t tcps_ecn_rcvect1; /* ECN Capable Transport */ uint64_t tcps_ecn_shs; /* ECN successful handshakes */ uint64_t tcps_ecn_rcwnd; /* # times ECN reduced the cwnd */ /* TCP_SIGNATURE related stats */ uint64_t tcps_sig_rcvgoodsig; /* Total matching signature received */ uint64_t tcps_sig_rcvbadsig; /* Total bad signature received */ uint64_t tcps_sig_err_buildsig; /* Failed to make signature */ uint64_t tcps_sig_err_sigopt; /* No signature expected by socket */ uint64_t tcps_sig_err_nosigopt; /* No signature provided by segment */ /* Path MTU Discovery Black Hole Detection related stats */ uint64_t tcps_pmtud_blackhole_activated; /* Black Hole Count */ uint64_t tcps_pmtud_blackhole_activated_min_mss; /* BH at min MSS Count */ uint64_t tcps_pmtud_blackhole_failed; /* Black Hole Failure Count */ uint64_t tcps_tunneled_pkts; /* Packets encap's in UDP received */ uint64_t tcps_tunneled_errs; /* Packets that had errors that were UDP encaped */ /* Dsack related stats */ uint64_t tcps_dsack_count; /* Number of ACKs arriving with DSACKs */ uint64_t tcps_dsack_bytes; /* Number of bytes DSACK'ed no TLP */ uint64_t tcps_dsack_tlp_bytes; /* Number of bytes DSACK'ed due to TLPs */ /* TCPS_TIME_WAIT usage stats */ uint64_t tcps_tw_recycles; /* Times time-wait was recycled. */ uint64_t tcps_tw_resets; /* Times time-wait sent a reset. */ uint64_t tcps_tw_responds; /* Times time-wait sent a valid ack. */ /* Accurate ECN Handshake stats */ uint64_t tcps_ace_nect; /* ACE SYN packet with Non-ECT */ uint64_t tcps_ace_ect1; /* ACE SYN packet with ECT1 */ uint64_t tcps_ace_ect0; /* ACE SYN packet with ECT0 */ uint64_t tcps_ace_ce; /* ACE SYN packet with CE */ /* ECN related stats */ uint64_t tcps_ecn_sndect0; /* ECN Capable Transport */ uint64_t tcps_ecn_sndect1; /* ECN Capable Transport */ /* * BBR and Rack implement TLP's these values count TLP bytes in * two catagories, bytes that were retransmitted and bytes that * were newly transmited. Both types can serve as TLP's but they * are accounted differently. */ uint64_t tcps_tlpresends; /* number of tlp resends */ uint64_t tcps_tlpresend_bytes; /* number of bytes resent by tlp */ uint64_t _pad[4]; /* 4 TBD placeholder for STABLE */ }; #define tcps_rcvmemdrop tcps_rcvreassfull /* compat */ #ifdef _KERNEL #define TI_UNLOCKED 1 #define TI_RLOCKED 2 #include VNET_PCPUSTAT_DECLARE(struct tcpstat, tcpstat); /* tcp statistics */ /* * In-kernel consumers can use these accessor macros directly to update * stats. */ #define TCPSTAT_ADD(name, val) \ VNET_PCPUSTAT_ADD(struct tcpstat, tcpstat, name, (val)) #define TCPSTAT_INC(name) TCPSTAT_ADD(name, 1) /* * Kernel module consumers must use this accessor macro. */ void kmod_tcpstat_add(int statnum, int val); #define KMOD_TCPSTAT_ADD(name, val) \ kmod_tcpstat_add(offsetof(struct tcpstat, name) / sizeof(uint64_t), val) #define KMOD_TCPSTAT_INC(name) KMOD_TCPSTAT_ADD(name, 1) /* * Running TCP connection count by state. */ VNET_DECLARE(counter_u64_t, tcps_states[TCP_NSTATES]); #define V_tcps_states VNET(tcps_states) #define TCPSTATES_INC(state) counter_u64_add(V_tcps_states[state], 1) #define TCPSTATES_DEC(state) counter_u64_add(V_tcps_states[state], -1) /* * 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; uint32_t len; int tso; tcp_seq curack; }; #ifdef TCP_HHOOK void hhook_run_tcp_est_out(struct tcpcb *tp, struct tcphdr *th, struct tcpopt *to, uint32_t len, int tso); #endif #endif /* * TCB structure exported to user-land via sysctl(3). * * Fields prefixed with "xt_" are unique to the export structure, and fields * with "t_" or other prefixes match corresponding fields of 'struct tcpcb'. * * Legend: * (s) - used by userland utilities in src * (p) - used by utilities in ports * (3) - is known to be used by third party software not in ports * (n) - no known usage * * 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 xtcpcb { ksize_t xt_len; /* length of this structure */ struct xinpcb xt_inp; char xt_stack[TCP_FUNCTION_NAME_LEN_MAX]; /* (s) */ char xt_logid[TCP_LOG_ID_LEN]; /* (s) */ char xt_cc[TCP_CA_NAME_MAX]; /* (s) */ int64_t spare64[6]; int32_t t_state; /* (s,p) */ uint32_t t_flags; /* (s,p) */ int32_t t_sndzerowin; /* (s) */ int32_t t_sndrexmitpack; /* (s) */ int32_t t_rcvoopack; /* (s) */ int32_t t_rcvtime; /* (s) */ int32_t tt_rexmt; /* (s) */ int32_t tt_persist; /* (s) */ int32_t tt_keep; /* (s) */ int32_t tt_2msl; /* (s) */ int32_t tt_delack; /* (s) */ int32_t t_logstate; /* (3) */ uint32_t t_snd_cwnd; /* (s) */ uint32_t t_snd_ssthresh; /* (s) */ uint32_t t_maxseg; /* (s) */ uint32_t t_rcv_wnd; /* (s) */ uint32_t t_snd_wnd; /* (s) */ uint32_t xt_ecn; /* (s) */ uint32_t t_dsack_bytes; /* (n) */ uint32_t t_dsack_tlp_bytes; /* (n) */ uint32_t t_dsack_pack; /* (n) */ uint16_t xt_encaps_port; /* (s) */ int16_t spare16; int32_t spare32[22]; } __aligned(8); #ifdef _KERNEL void tcp_inptoxtp(const struct inpcb *, struct xtcpcb *); #endif #endif /* * TCP function information (name-to-id mapping, aliases, and refcnt) * exported to user-land via sysctl(3). */ struct tcp_function_info { uint32_t tfi_refcnt; uint8_t tfi_id; char tfi_name[TCP_FUNCTION_NAME_LEN_MAX]; char tfi_alias[TCP_FUNCTION_NAME_LEN_MAX]; }; /* * Identifiers for TCP sysctl nodes */ #define TCPCTL_DO_RFC1323 1 /* use RFC-1323 extensions */ #define TCPCTL_MSSDFLT 3 /* MSS default */ #define TCPCTL_STATS 4 /* statistics */ #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_STATES 16 /* connection counts by TCP state */ #ifdef _KERNEL #ifdef SYSCTL_DECL SYSCTL_DECL(_net_inet_tcp); SYSCTL_DECL(_net_inet_tcp_sack); MALLOC_DECLARE(M_TCPLOG); #endif VNET_DECLARE(int, tcp_log_in_vain); #define V_tcp_log_in_vain VNET(tcp_log_in_vain) /* * Global TCP tunables shared between different stacks. * Please keep the list sorted. */ VNET_DECLARE(int, drop_synfin); VNET_DECLARE(int, path_mtu_discovery); VNET_DECLARE(int, tcp_abc_l_var); VNET_DECLARE(int, tcp_autorcvbuf_max); VNET_DECLARE(int, tcp_autosndbuf_inc); VNET_DECLARE(int, tcp_autosndbuf_max); VNET_DECLARE(int, tcp_delack_enabled); VNET_DECLARE(int, tcp_do_autorcvbuf); VNET_DECLARE(int, tcp_do_autosndbuf); VNET_DECLARE(int, tcp_do_ecn); VNET_DECLARE(int, tcp_do_lrd); VNET_DECLARE(int, tcp_do_prr); VNET_DECLARE(int, tcp_do_prr_conservative); VNET_DECLARE(int, tcp_do_newcwv); VNET_DECLARE(int, tcp_do_rfc1323); VNET_DECLARE(int, tcp_tolerate_missing_ts); VNET_DECLARE(int, tcp_do_rfc3042); VNET_DECLARE(int, tcp_do_rfc3390); VNET_DECLARE(int, tcp_do_rfc3465); VNET_DECLARE(int, tcp_do_newsack); VNET_DECLARE(int, tcp_do_sack); VNET_DECLARE(int, tcp_do_tso); VNET_DECLARE(int, tcp_ecn_maxretries); VNET_DECLARE(int, tcp_initcwnd_segments); VNET_DECLARE(int, tcp_insecure_rst); VNET_DECLARE(int, tcp_insecure_syn); VNET_DECLARE(uint32_t, tcp_map_entries_limit); VNET_DECLARE(uint32_t, tcp_map_split_limit); VNET_DECLARE(int, tcp_minmss); VNET_DECLARE(int, tcp_mssdflt); #ifdef STATS VNET_DECLARE(int, tcp_perconn_stats_dflt_tpl); VNET_DECLARE(int, tcp_perconn_stats_enable); #endif /* STATS */ VNET_DECLARE(int, tcp_recvspace); VNET_DECLARE(int, tcp_sack_globalholes); VNET_DECLARE(int, tcp_sack_globalmaxholes); VNET_DECLARE(int, tcp_sack_maxholes); VNET_DECLARE(int, tcp_sc_rst_sock_fail); VNET_DECLARE(int, tcp_sendspace); VNET_DECLARE(int, tcp_udp_tunneling_overhead); VNET_DECLARE(int, tcp_udp_tunneling_port); VNET_DECLARE(struct inpcbinfo, tcbinfo); #define V_tcp_do_lrd VNET(tcp_do_lrd) #define V_tcp_do_prr VNET(tcp_do_prr) #define V_tcp_do_prr_conservative VNET(tcp_do_prr_conservative) #define V_tcp_do_newcwv VNET(tcp_do_newcwv) #define V_drop_synfin VNET(drop_synfin) #define V_path_mtu_discovery VNET(path_mtu_discovery) #define V_tcbinfo VNET(tcbinfo) #define V_tcp_abc_l_var VNET(tcp_abc_l_var) #define V_tcp_autorcvbuf_max VNET(tcp_autorcvbuf_max) #define V_tcp_autosndbuf_inc VNET(tcp_autosndbuf_inc) #define V_tcp_autosndbuf_max VNET(tcp_autosndbuf_max) #define V_tcp_delack_enabled VNET(tcp_delack_enabled) #define V_tcp_do_autorcvbuf VNET(tcp_do_autorcvbuf) #define V_tcp_do_autosndbuf VNET(tcp_do_autosndbuf) #define V_tcp_do_ecn VNET(tcp_do_ecn) #define V_tcp_do_rfc1323 VNET(tcp_do_rfc1323) #define V_tcp_tolerate_missing_ts VNET(tcp_tolerate_missing_ts) #define V_tcp_ts_offset_per_conn VNET(tcp_ts_offset_per_conn) #define V_tcp_do_rfc3042 VNET(tcp_do_rfc3042) #define V_tcp_do_rfc3390 VNET(tcp_do_rfc3390) #define V_tcp_do_rfc3465 VNET(tcp_do_rfc3465) #define V_tcp_do_newsack VNET(tcp_do_newsack) #define V_tcp_do_sack VNET(tcp_do_sack) #define V_tcp_do_tso VNET(tcp_do_tso) #define V_tcp_ecn_maxretries VNET(tcp_ecn_maxretries) #define V_tcp_initcwnd_segments VNET(tcp_initcwnd_segments) #define V_tcp_insecure_rst VNET(tcp_insecure_rst) #define V_tcp_insecure_syn VNET(tcp_insecure_syn) #define V_tcp_map_entries_limit VNET(tcp_map_entries_limit) #define V_tcp_map_split_limit VNET(tcp_map_split_limit) #define V_tcp_minmss VNET(tcp_minmss) #define V_tcp_mssdflt VNET(tcp_mssdflt) #ifdef STATS #define V_tcp_perconn_stats_dflt_tpl VNET(tcp_perconn_stats_dflt_tpl) #define V_tcp_perconn_stats_enable VNET(tcp_perconn_stats_enable) #endif /* STATS */ #define V_tcp_recvspace VNET(tcp_recvspace) #define V_tcp_sack_globalholes VNET(tcp_sack_globalholes) #define V_tcp_sack_globalmaxholes VNET(tcp_sack_globalmaxholes) #define V_tcp_sack_maxholes VNET(tcp_sack_maxholes) #define V_tcp_sc_rst_sock_fail VNET(tcp_sc_rst_sock_fail) #define V_tcp_sendspace VNET(tcp_sendspace) #define V_tcp_udp_tunneling_overhead VNET(tcp_udp_tunneling_overhead) #define V_tcp_udp_tunneling_port VNET(tcp_udp_tunneling_port) #ifdef TCP_HHOOK VNET_DECLARE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST + 1]); #define V_tcp_hhh VNET(tcp_hhh) #endif int tcp_addoptions(struct tcpopt *, u_char *); struct tcpcb * tcp_close(struct tcpcb *); void tcp_discardcb(struct tcpcb *); void tcp_twstart(struct tcpcb *); int tcp_ctloutput(struct socket *, struct sockopt *); void tcp_fini(void *); char *tcp_log_addrs(struct in_conninfo *, struct tcphdr *, const void *, const void *); char *tcp_log_vain(struct in_conninfo *, struct tcphdr *, const void *, const void *); int tcp_reass(struct tcpcb *, struct tcphdr *, tcp_seq *, int *, struct mbuf *); void tcp_reass_global_init(void); void tcp_reass_flush(struct tcpcb *); void tcp_dooptions(struct tcpopt *, u_char *, int, int); void tcp_dropwithreset(struct mbuf *, struct tcphdr *, struct tcpcb *, int, int); void tcp_pulloutofband(struct socket *, struct tcphdr *, struct mbuf *, int); void tcp_xmit_timer(struct tcpcb *, int); void tcp_newreno_partial_ack(struct tcpcb *, struct tcphdr *); void cc_ack_received(struct tcpcb *tp, struct tcphdr *th, uint16_t nsegs, uint16_t type); void cc_conn_init(struct tcpcb *tp); void cc_post_recovery(struct tcpcb *tp, struct tcphdr *th); void cc_ecnpkt_handler(struct tcpcb *tp, struct tcphdr *th, uint8_t iptos); void cc_ecnpkt_handler_flags(struct tcpcb *tp, uint16_t flags, uint8_t iptos); void cc_cong_signal(struct tcpcb *tp, struct tcphdr *th, uint32_t type); #ifdef TCP_HHOOK void hhook_run_tcp_est_in(struct tcpcb *tp, struct tcphdr *th, struct tcpopt *to); #endif int tcp_input(struct mbuf **, int *, int); int tcp_autorcvbuf(struct mbuf *, struct tcphdr *, struct socket *, struct tcpcb *, int); int tcp_input_with_port(struct mbuf **, int *, int, uint16_t); void tcp_do_segment(struct tcpcb *, struct mbuf *, struct tcphdr *, int, int, uint8_t); int register_tcp_functions(struct tcp_function_block *blk, int wait); int register_tcp_functions_as_names(struct tcp_function_block *blk, int wait, const char *names[], int *num_names); int register_tcp_functions_as_name(struct tcp_function_block *blk, const char *name, int wait); int deregister_tcp_functions(struct tcp_function_block *blk, bool quiesce, bool force); struct tcp_function_block *find_and_ref_tcp_functions(struct tcp_function_set *fs); int find_tcp_function_alias(struct tcp_function_block *blk, struct tcp_function_set *fs); void tcp_switch_back_to_default(struct tcpcb *tp); struct tcp_function_block * find_and_ref_tcp_fb(struct tcp_function_block *fs); int tcp_default_ctloutput(struct tcpcb *tp, struct sockopt *sopt); int tcp_ctloutput_set(struct inpcb *inp, struct sockopt *sopt); void tcp_log_socket_option(struct tcpcb *tp, uint32_t option_num, uint32_t option_val, int err); extern counter_u64_t tcp_inp_lro_direct_queue; extern counter_u64_t tcp_inp_lro_wokeup_queue; extern counter_u64_t tcp_inp_lro_compressed; extern counter_u64_t tcp_inp_lro_locks_taken; extern counter_u64_t tcp_extra_mbuf; extern counter_u64_t tcp_would_have_but; extern counter_u64_t tcp_comp_total; extern counter_u64_t tcp_uncomp_total; extern counter_u64_t tcp_bad_csums; #ifdef TCP_SAD_DETECTION /* Various SACK attack thresholds */ extern int32_t tcp_force_detection; extern int32_t tcp_sad_limit; extern int32_t tcp_sack_to_ack_thresh; extern int32_t tcp_sack_to_move_thresh; extern int32_t tcp_restoral_thresh; extern int32_t tcp_sad_decay_val; extern int32_t tcp_sad_pacing_interval; extern int32_t tcp_sad_low_pps; extern int32_t tcp_map_minimum; extern int32_t tcp_attack_on_turns_on_logging; #endif extern uint32_t tcp_ack_war_time_window; extern uint32_t tcp_ack_war_cnt; uint32_t tcp_maxmtu(struct in_conninfo *, struct tcp_ifcap *); uint32_t tcp_maxmtu6(struct in_conninfo *, struct tcp_ifcap *); void tcp6_use_min_mtu(struct tcpcb *); u_int tcp_maxseg(const struct tcpcb *); u_int tcp_fixed_maxseg(const struct tcpcb *); void tcp_mss_update(struct tcpcb *, int, int, struct hc_metrics_lite *, struct tcp_ifcap *); void tcp_mss(struct tcpcb *, int); int tcp_mssopt(struct in_conninfo *); struct tcpcb * tcp_newtcpcb(struct inpcb *); int tcp_default_output(struct tcpcb *); void tcp_state_change(struct tcpcb *, int); void tcp_respond(struct tcpcb *, void *, struct tcphdr *, struct mbuf *, tcp_seq, tcp_seq, uint16_t); bool tcp_twcheck(struct inpcb *, struct tcpopt *, struct tcphdr *, struct mbuf *, int); void tcp_setpersist(struct tcpcb *); void tcp_record_dsack(struct tcpcb *tp, tcp_seq start, tcp_seq end, int tlp); struct tcptemp * tcpip_maketemplate(struct inpcb *); void tcpip_fillheaders(struct inpcb *, uint16_t, void *, void *); void tcp_timer_activate(struct tcpcb *, tt_which, u_int); bool tcp_timer_active(struct tcpcb *, tt_which); void tcp_timer_stop(struct tcpcb *); int inp_to_cpuid(struct inpcb *inp); /* * 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 *); uint32_t tcp_hc_getmtu(struct in_conninfo *); void tcp_hc_updatemtu(struct in_conninfo *, uint32_t); void tcp_hc_update(struct in_conninfo *, struct hc_metrics_lite *); void cc_after_idle(struct tcpcb *tp); extern struct protosw tcp_protosw; /* shared for TOE */ extern struct protosw tcp6_protosw; /* shared for TOE */ uint32_t tcp_new_ts_offset(struct in_conninfo *); tcp_seq tcp_new_isn(struct in_conninfo *); int tcp_sack_doack(struct tcpcb *, struct tcpopt *, tcp_seq); int tcp_dsack_block_exists(struct tcpcb *); void tcp_update_dsack_list(struct tcpcb *, tcp_seq, tcp_seq); void tcp_update_sack_list(struct tcpcb *tp, tcp_seq rcv_laststart, tcp_seq rcv_lastend); void tcp_clean_dsack_blocks(struct tcpcb *tp); 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_do_prr_ack(struct tcpcb *, struct tcphdr *, struct tcpopt *); void tcp_lost_retransmission(struct tcpcb *, struct tcphdr *); void tcp_sack_partialack(struct tcpcb *, struct tcphdr *); void tcp_free_sackholes(struct tcpcb *tp); void tcp_sack_lost_retransmission(struct tcpcb *, struct tcphdr *); int tcp_newreno(struct tcpcb *, struct tcphdr *); int tcp_compute_pipe(struct tcpcb *); uint32_t tcp_compute_initwnd(uint32_t); void tcp_sndbuf_autoscale(struct tcpcb *, struct socket *, uint32_t); int tcp_stats_sample_rollthedice(struct tcpcb *tp, void *seed_bytes, size_t seed_len); int tcp_can_enable_pacing(void); void tcp_decrement_paced_conn(void); void tcp_change_time_units(struct tcpcb *, int); void tcp_handle_orphaned_packets(struct tcpcb *); struct mbuf * tcp_m_copym(struct mbuf *m, int32_t off0, int32_t *plen, int32_t seglimit, int32_t segsize, struct sockbuf *sb, bool hw_tls); int tcp_stats_init(void); void tcp_log_end_status(struct tcpcb *tp, uint8_t status); #ifdef TCP_REQUEST_TRK void tcp_http_free_a_slot(struct tcpcb *tp, struct http_sendfile_track *ent); struct http_sendfile_track * tcp_http_find_a_req_that_is_completed_by(struct tcpcb *tp, tcp_seq th_ack, int *ip); int tcp_http_check_for_comp(struct tcpcb *tp, tcp_seq ack_point); int tcp_http_is_entry_comp(struct tcpcb *tp, struct http_sendfile_track *ent, tcp_seq ack_point); struct http_sendfile_track * tcp_http_find_req_for_seq(struct tcpcb *tp, tcp_seq seq); void tcp_http_log_req_info(struct tcpcb *tp, struct http_sendfile_track *http, uint16_t slot, uint8_t val, uint64_t offset, uint64_t nbytes); uint32_t tcp_estimate_tls_overhead(struct socket *so, uint64_t tls_usr_bytes); void tcp_http_alloc_req(struct tcpcb *tp, union tcp_log_userdata *user, uint64_t ts); struct http_sendfile_track * tcp_http_alloc_req_full(struct tcpcb *tp, struct http_req *req, uint64_t ts, int rec_dups); #endif #ifdef TCP_ACCOUNTING int tcp_do_ack_accounting(struct tcpcb *tp, struct tcphdr *th, struct tcpopt *to, uint32_t tiwin, int mss); #endif static inline void tcp_fields_to_host(struct tcphdr *th) { th->th_seq = ntohl(th->th_seq); th->th_ack = ntohl(th->th_ack); th->th_win = ntohs(th->th_win); th->th_urp = ntohs(th->th_urp); } static inline void tcp_fields_to_net(struct tcphdr *th) { th->th_seq = htonl(th->th_seq); th->th_ack = htonl(th->th_ack); th->th_win = htons(th->th_win); th->th_urp = htons(th->th_urp); } static inline uint16_t tcp_get_flags(const struct tcphdr *th) { return (((uint16_t)th->th_x2 << 8) | th->th_flags); } static inline void tcp_set_flags(struct tcphdr *th, uint16_t flags) { th->th_x2 = (flags >> 8) & 0x0f; th->th_flags = flags & 0xff; } static inline void tcp_account_for_send(struct tcpcb *tp, uint32_t len, uint8_t is_rxt, uint8_t is_tlp, bool hw_tls) { if (is_tlp) { tp->t_sndtlppack++; tp->t_sndtlpbyte += len; } /* To get total bytes sent you must add t_snd_rxt_bytes to t_sndbytes */ if (is_rxt) tp->t_snd_rxt_bytes += len; else tp->t_sndbytes += len; #ifdef KERN_TLS if (hw_tls && is_rxt && len != 0) { uint64_t rexmit_percent = (1000ULL * tp->t_snd_rxt_bytes) / (10ULL * (tp->t_snd_rxt_bytes + tp->t_sndbytes)); if (rexmit_percent > ktls_ifnet_max_rexmit_pct) ktls_disable_ifnet(tp); } #endif } #endif /* _KERNEL */ #endif /* _NETINET_TCP_VAR_H_ */