1/*
2 * Copyright (c) 1982, 1986, 1993, 1994, 1995
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 * @(#)tcp_var.h 8.4 (Berkeley) 5/24/95
34 * $Id: tcp_var.h,v 1.23 1995/11/14 20:34:50 phk Exp $
35 */
36
37#ifndef _NETINET_TCP_VAR_H_
38#define _NETINET_TCP_VAR_H_
39/*
40 * Kernel variables for tcp.
41 */
42
43/*
44 * Tcp control block, one per tcp; fields:
45 */
46struct tcpcb {
47 struct tcpiphdr *seg_next; /* sequencing queue */
48 struct tcpiphdr *seg_prev;
49 int t_state; /* state of this connection */
50 int t_timer[TCPT_NTIMERS]; /* tcp timers */
51 int t_rxtshift; /* log(2) of rexmt exp. backoff */
52 int t_rxtcur; /* current retransmit value */
53 int t_dupacks; /* consecutive dup acks recd */
54 u_int t_maxseg; /* maximum segment size */
55 u_int t_maxopd; /* mss plus options */
56 int t_force; /* 1 if forcing out a byte */
57 u_int t_flags;
58#define TF_ACKNOW 0x0001 /* ack peer immediately */
59#define TF_DELACK 0x0002 /* ack, but try to delay it */
60#define TF_NODELAY 0x0004 /* don't delay packets to coalesce */
61#define TF_NOOPT 0x0008 /* don't use tcp options */
62#define TF_SENTFIN 0x0010 /* have sent FIN */
63#define TF_REQ_SCALE 0x0020 /* have/will request window scaling */
64#define TF_RCVD_SCALE 0x0040 /* other side has requested scaling */
65#define TF_REQ_TSTMP 0x0080 /* have/will request timestamps */
66#define TF_RCVD_TSTMP 0x0100 /* a timestamp was received in SYN */
67#define TF_SACK_PERMIT 0x0200 /* other side said I could SACK */
68#define TF_NEEDSYN 0x0400 /* send SYN (implicit state) */
69#define TF_NEEDFIN 0x0800 /* send FIN (implicit state) */
70#define TF_NOPUSH 0x1000 /* don't push */
71#define TF_REQ_CC 0x2000 /* have/will request CC */
72#define TF_RCVD_CC 0x4000 /* a CC was received in SYN */
73#define TF_SENDCCNEW 0x8000 /* send CCnew instead of CC in SYN */
74
75 struct tcpiphdr *t_template; /* skeletal packet for transmit */
76 struct inpcb *t_inpcb; /* back pointer to internet pcb */
77/*
78 * The following fields are used as in the protocol specification.
79 * See RFC783, Dec. 1981, page 21.
80 */
81/* send sequence variables */
82 tcp_seq snd_una; /* send unacknowledged */
83 tcp_seq snd_nxt; /* send next */
84 tcp_seq snd_up; /* send urgent pointer */
85 tcp_seq snd_wl1; /* window update seg seq number */
86 tcp_seq snd_wl2; /* window update seg ack number */
87 tcp_seq iss; /* initial send sequence number */
88 u_long snd_wnd; /* send window */
89/* receive sequence variables */
90 u_long rcv_wnd; /* receive window */
91 tcp_seq rcv_nxt; /* receive next */
92 tcp_seq rcv_up; /* receive urgent pointer */
93 tcp_seq irs; /* initial receive sequence number */
94/*
95 * Additional variables for this implementation.
96 */
97/* receive variables */
98 tcp_seq rcv_adv; /* advertised window */
99/* retransmit variables */
100 tcp_seq snd_max; /* highest sequence number sent;
101 * used to recognize retransmits
102 */
103/* congestion control (for slow start, source quench, retransmit after loss) */
104 u_long snd_cwnd; /* congestion-controlled window */
105 u_long snd_ssthresh; /* snd_cwnd size threshhold for
106 * for slow start exponential to
107 * linear switch
108 */
109/*
110 * transmit timing stuff. See below for scale of srtt and rttvar.
111 * "Variance" is actually smoothed difference.
112 */
113 u_int t_idle; /* inactivity time */
114 int t_rtt; /* round trip time */
115 tcp_seq t_rtseq; /* sequence number being timed */
116 int t_srtt; /* smoothed round-trip time */
117 int t_rttvar; /* variance in round-trip time */
118 u_int t_rttmin; /* minimum rtt allowed */
119 u_long max_sndwnd; /* largest window peer has offered */
120
121/* out-of-band data */
122 char t_oobflags; /* have some */
123 char t_iobc; /* input character */
124#define TCPOOB_HAVEDATA 0x01
125#define TCPOOB_HADDATA 0x02
126 int t_softerror; /* possible error not yet reported */
127
128/* RFC 1323 variables */
129 u_char snd_scale; /* window scaling for send window */
130 u_char rcv_scale; /* window scaling for recv window */
131 u_char request_r_scale; /* pending window scaling */
132 u_char requested_s_scale;
133 u_long ts_recent; /* timestamp echo data */
134 u_long ts_recent_age; /* when last updated */
135 tcp_seq last_ack_sent;
136/* RFC 1644 variables */
137 tcp_cc cc_send; /* send connection count */
138 tcp_cc cc_recv; /* receive connection count */
139 u_long t_duration; /* connection duration */
140
141/* TUBA stuff */
142 caddr_t t_tuba_pcb; /* next level down pcb for TCP over z */
143/* More RTT stuff */
144 u_long t_rttupdated; /* number of times rtt sampled */
145};
146
147/*
148 * Structure to hold TCP options that are only used during segment
149 * processing (in tcp_input), but not held in the tcpcb.
150 * It's basically used to reduce the number of parameters
151 * to tcp_dooptions.
152 */
153struct tcpopt {
154 u_long to_flag; /* which options are present */
155#define TOF_TS 0x0001 /* timestamp */
156#define TOF_CC 0x0002 /* CC and CCnew are exclusive */
157#define TOF_CCNEW 0x0004
158#define TOF_CCECHO 0x0008
159 u_long to_tsval;
160 u_long to_tsecr;
161 tcp_cc to_cc; /* holds CC or CCnew */
162 tcp_cc to_ccecho;
163};
164
165/*
166 * The TAO cache entry which is stored in the protocol family specific
167 * portion of the route metrics.
168 */
169struct rmxp_tao {
170 tcp_cc tao_cc; /* latest CC in valid SYN */
171 tcp_cc tao_ccsent; /* latest CC sent to peer */
172 u_short tao_mssopt; /* peer's cached MSS */
173#ifdef notyet
174 u_short tao_flags; /* cache status flags */
175#define TAOF_DONT 0x0001 /* peer doesn't understand rfc1644 */
176#define TAOF_OK 0x0002 /* peer does understand rfc1644 */
177#define TAOF_UNDEF 0 /* we don't know yet */
178#endif /* notyet */
179};
180#define rmx_taop(r) ((struct rmxp_tao *)(r).rmx_filler)
181
182#define intotcpcb(ip) ((struct tcpcb *)(ip)->inp_ppcb)
183#define sototcpcb(so) (intotcpcb(sotoinpcb(so)))
184
185/*
186 * The smoothed round-trip time and estimated variance
187 * are stored as fixed point numbers scaled by the values below.
188 * For convenience, these scales are also used in smoothing the average
189 * (smoothed = (1/scale)sample + ((scale-1)/scale)smoothed).
190 * With these scales, srtt has 3 bits to the right of the binary point,
191 * and thus an "ALPHA" of 0.875. rttvar has 2 bits to the right of the
192 * binary point, and is smoothed with an ALPHA of 0.75.
193 */
194#define TCP_RTT_SCALE 8 /* multiplier for srtt; 3 bits frac. */
195#define TCP_RTT_SHIFT 3 /* shift for srtt; 3 bits frac. */
196#define TCP_RTTVAR_SCALE 4 /* multiplier for rttvar; 2 bits */
197#define TCP_RTTVAR_SHIFT 2 /* shift for rttvar; 2 bits */
198
199/*
200 * The initial retransmission should happen at rtt + 4 * rttvar.
201 * Because of the way we do the smoothing, srtt and rttvar
202 * will each average +1/2 tick of bias. When we compute
203 * the retransmit timer, we want 1/2 tick of rounding and
204 * 1 extra tick because of +-1/2 tick uncertainty in the
205 * firing of the timer. The bias will give us exactly the
206 * 1.5 tick we need. But, because the bias is
207 * statistical, we have to test that we don't drop below
208 * the minimum feasible timer (which is 2 ticks).
209 * This macro assumes that the value of TCP_RTTVAR_SCALE
210 * is the same as the multiplier for rttvar.
211 */
212#define TCP_REXMTVAL(tp) \
213 (((tp)->t_srtt >> TCP_RTT_SHIFT) + (tp)->t_rttvar)
214
215/* XXX
216 * We want to avoid doing m_pullup on incoming packets but that
217 * means avoiding dtom on the tcp reassembly code. That in turn means
218 * keeping an mbuf pointer in the reassembly queue (since we might
219 * have a cluster). As a quick hack, the source & destination
220 * port numbers (which are no longer needed once we've located the
221 * tcpcb) are overlayed with an mbuf pointer.
222 */
223#define REASS_MBUF(ti) (*(struct mbuf **)&((ti)->ti_t))
224
225/*
226 * TCP statistics.
227 * Many of these should be kept per connection,
228 * but that's inconvenient at the moment.
229 */
230struct tcpstat {
231 u_long tcps_connattempt; /* connections initiated */
232 u_long tcps_accepts; /* connections accepted */
233 u_long tcps_connects; /* connections established */
234 u_long tcps_drops; /* connections dropped */
235 u_long tcps_conndrops; /* embryonic connections dropped */
236 u_long tcps_closed; /* conn. closed (includes drops) */
237 u_long tcps_segstimed; /* segs where we tried to get rtt */
238 u_long tcps_rttupdated; /* times we succeeded */
239 u_long tcps_delack; /* delayed acks sent */
240 u_long tcps_timeoutdrop; /* conn. dropped in rxmt timeout */
241 u_long tcps_rexmttimeo; /* retransmit timeouts */
242 u_long tcps_persisttimeo; /* persist timeouts */
243 u_long tcps_keeptimeo; /* keepalive timeouts */
244 u_long tcps_keepprobe; /* keepalive probes sent */
245 u_long tcps_keepdrops; /* connections dropped in keepalive */
246
247 u_long tcps_sndtotal; /* total packets sent */
248 u_long tcps_sndpack; /* data packets sent */
249 u_long tcps_sndbyte; /* data bytes sent */
250 u_long tcps_sndrexmitpack; /* data packets retransmitted */
251 u_long tcps_sndrexmitbyte; /* data bytes retransmitted */
252 u_long tcps_sndacks; /* ack-only packets sent */
253 u_long tcps_sndprobe; /* window probes sent */
254 u_long tcps_sndurg; /* packets sent with URG only */
255 u_long tcps_sndwinup; /* window update-only packets sent */
256 u_long tcps_sndctrl; /* control (SYN|FIN|RST) packets sent */
257
258 u_long tcps_rcvtotal; /* total packets received */
259 u_long tcps_rcvpack; /* packets received in sequence */
260 u_long tcps_rcvbyte; /* bytes received in sequence */
261 u_long tcps_rcvbadsum; /* packets received with ccksum errs */
262 u_long tcps_rcvbadoff; /* packets received with bad offset */
263 u_long tcps_rcvshort; /* packets received too short */
264 u_long tcps_rcvduppack; /* duplicate-only packets received */
265 u_long tcps_rcvdupbyte; /* duplicate-only bytes received */
266 u_long tcps_rcvpartduppack; /* packets with some duplicate data */
267 u_long tcps_rcvpartdupbyte; /* dup. bytes in part-dup. packets */
268 u_long tcps_rcvoopack; /* out-of-order packets received */
269 u_long tcps_rcvoobyte; /* out-of-order bytes received */
270 u_long tcps_rcvpackafterwin; /* packets with data after window */
271 u_long tcps_rcvbyteafterwin; /* bytes rcvd after window */
272 u_long tcps_rcvafterclose; /* packets rcvd after "close" */
273 u_long tcps_rcvwinprobe; /* rcvd window probe packets */
274 u_long tcps_rcvdupack; /* rcvd duplicate acks */
275 u_long tcps_rcvacktoomuch; /* rcvd acks for unsent data */
276 u_long tcps_rcvackpack; /* rcvd ack packets */
277 u_long tcps_rcvackbyte; /* bytes acked by rcvd acks */
278 u_long tcps_rcvwinupd; /* rcvd window update packets */
279 u_long tcps_pawsdrop; /* segments dropped due to PAWS */
280 u_long tcps_predack; /* times hdr predict ok for acks */
281 u_long tcps_preddat; /* times hdr predict ok for data pkts */
282 u_long tcps_pcbcachemiss;
283 u_long tcps_cachedrtt; /* times cached RTT in route updated */
284 u_long tcps_cachedrttvar; /* times cached rttvar updated */
285 u_long tcps_cachedssthresh; /* times cached ssthresh updated */
286 u_long tcps_usedrtt; /* times RTT initialized from route */
287 u_long tcps_usedrttvar; /* times RTTVAR initialized from rt */
288 u_long tcps_usedssthresh; /* times ssthresh initialized from rt*/
289 u_long tcps_persistdrop; /* timeout in persist state */
290 u_long tcps_badsyn; /* bogus SYN, e.g. premature ACK */
291 u_long tcps_mturesent; /* resends due to MTU discovery */
292};
293
294/*
295 * Names for TCP sysctl objects
296 */
297#define TCPCTL_DO_RFC1323 1 /* use RFC-1323 extensions */
298#define TCPCTL_DO_RFC1644 2 /* use RFC-1644 extensions */
299#define TCPCTL_MSSDFLT 3 /* MSS default */
300#define TCPCTL_STATS 4 /* statistics (read-only) */
301#define TCPCTL_RTTDFLT 5 /* default RTT estimate */
302#define TCPCTL_KEEPIDLE 6 /* keepalive idle timer */
303#define TCPCTL_KEEPINTVL 7 /* interval to send keepalives */
304#define TCPCTL_SENDSPACE 8 /* send buffer space */
305#define TCPCTL_RECVSPACE 9 /* receive buffer space */
306#define TCPCTL_MAXID 10
307
308#define TCPCTL_NAMES { \
309 { 0, 0 }, \
310 { "rfc1323", CTLTYPE_INT }, \
311 { "rfc1644", CTLTYPE_INT }, \
312 { "mssdflt", CTLTYPE_INT }, \
313 { "stats", CTLTYPE_STRUCT }, \
314 { "rttdflt", CTLTYPE_INT }, \
315 { "keepidle", CTLTYPE_INT }, \
316 { "keepintvl", CTLTYPE_INT }, \
317 { "sendspace", CTLTYPE_INT }, \
318 { "recvspace", CTLTYPE_INT }, \
319}
320
321#ifdef KERNEL
322extern struct inpcbhead tcb; /* head of queue of active tcpcb's */
323extern struct inpcbinfo tcbinfo;
324extern struct tcpstat tcpstat; /* tcp statistics */
325extern int tcp_do_rfc1323; /* XXX */
326extern int tcp_do_rfc1644; /* XXX */
327extern int tcp_mssdflt; /* XXX */
328extern u_long tcp_now; /* for RFC 1323 timestamps */
329extern int tcp_rttdflt; /* XXX */
330extern u_short tcp_lastport; /* last assigned port */
331
332void tcp_canceltimers __P((struct tcpcb *));
333struct tcpcb *
334 tcp_close __P((struct tcpcb *));
335void tcp_ctlinput __P((int, struct sockaddr *, struct ip *));
336int tcp_ctloutput __P((int, struct socket *, int, int, struct mbuf **));
337struct tcpcb *
338 tcp_drop __P((struct tcpcb *, int));
339void tcp_drain __P((void));
340void tcp_fasttimo __P((void));
341struct rmxp_tao *
342 tcp_gettaocache __P((struct inpcb *));
343void tcp_init __P((void));
344void tcp_input __P((struct mbuf *, int));
345void tcp_mss __P((struct tcpcb *, int));
346int tcp_mssopt __P((struct tcpcb *));
347void tcp_mtudisc __P((struct inpcb *, int));
348struct tcpcb *
349 tcp_newtcpcb __P((struct inpcb *));
350int tcp_output __P((struct tcpcb *));
351void tcp_quench __P((struct inpcb *, int));
352void tcp_respond __P((struct tcpcb *,
353 struct tcpiphdr *, struct mbuf *, u_long, u_long, int));
354struct rtentry *
355 tcp_rtlookup __P((struct inpcb *));
356void tcp_setpersist __P((struct tcpcb *));
357void tcp_slowtimo __P((void));
358struct tcpiphdr *
359 tcp_template __P((struct tcpcb *));
360struct tcpcb *
361 tcp_timers __P((struct tcpcb *, int));
362void tcp_trace __P((int, int, struct tcpcb *, struct tcpiphdr *, int));
363int tcp_usrreq __P((struct socket *,
364 int, struct mbuf *, struct mbuf *, struct mbuf *));
365
366extern u_long tcp_sendspace;
367extern u_long tcp_recvspace;
368
369#endif /* KERNEL */
370
371#endif /* _NETINET_TCP_VAR_H_ */
2 * Copyright (c) 1982, 1986, 1993, 1994, 1995
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 * @(#)tcp_var.h 8.4 (Berkeley) 5/24/95
34 * $Id: tcp_var.h,v 1.23 1995/11/14 20:34:50 phk Exp $
35 */
36
37#ifndef _NETINET_TCP_VAR_H_
38#define _NETINET_TCP_VAR_H_
39/*
40 * Kernel variables for tcp.
41 */
42
43/*
44 * Tcp control block, one per tcp; fields:
45 */
46struct tcpcb {
47 struct tcpiphdr *seg_next; /* sequencing queue */
48 struct tcpiphdr *seg_prev;
49 int t_state; /* state of this connection */
50 int t_timer[TCPT_NTIMERS]; /* tcp timers */
51 int t_rxtshift; /* log(2) of rexmt exp. backoff */
52 int t_rxtcur; /* current retransmit value */
53 int t_dupacks; /* consecutive dup acks recd */
54 u_int t_maxseg; /* maximum segment size */
55 u_int t_maxopd; /* mss plus options */
56 int t_force; /* 1 if forcing out a byte */
57 u_int t_flags;
58#define TF_ACKNOW 0x0001 /* ack peer immediately */
59#define TF_DELACK 0x0002 /* ack, but try to delay it */
60#define TF_NODELAY 0x0004 /* don't delay packets to coalesce */
61#define TF_NOOPT 0x0008 /* don't use tcp options */
62#define TF_SENTFIN 0x0010 /* have sent FIN */
63#define TF_REQ_SCALE 0x0020 /* have/will request window scaling */
64#define TF_RCVD_SCALE 0x0040 /* other side has requested scaling */
65#define TF_REQ_TSTMP 0x0080 /* have/will request timestamps */
66#define TF_RCVD_TSTMP 0x0100 /* a timestamp was received in SYN */
67#define TF_SACK_PERMIT 0x0200 /* other side said I could SACK */
68#define TF_NEEDSYN 0x0400 /* send SYN (implicit state) */
69#define TF_NEEDFIN 0x0800 /* send FIN (implicit state) */
70#define TF_NOPUSH 0x1000 /* don't push */
71#define TF_REQ_CC 0x2000 /* have/will request CC */
72#define TF_RCVD_CC 0x4000 /* a CC was received in SYN */
73#define TF_SENDCCNEW 0x8000 /* send CCnew instead of CC in SYN */
74
75 struct tcpiphdr *t_template; /* skeletal packet for transmit */
76 struct inpcb *t_inpcb; /* back pointer to internet pcb */
77/*
78 * The following fields are used as in the protocol specification.
79 * See RFC783, Dec. 1981, page 21.
80 */
81/* send sequence variables */
82 tcp_seq snd_una; /* send unacknowledged */
83 tcp_seq snd_nxt; /* send next */
84 tcp_seq snd_up; /* send urgent pointer */
85 tcp_seq snd_wl1; /* window update seg seq number */
86 tcp_seq snd_wl2; /* window update seg ack number */
87 tcp_seq iss; /* initial send sequence number */
88 u_long snd_wnd; /* send window */
89/* receive sequence variables */
90 u_long rcv_wnd; /* receive window */
91 tcp_seq rcv_nxt; /* receive next */
92 tcp_seq rcv_up; /* receive urgent pointer */
93 tcp_seq irs; /* initial receive sequence number */
94/*
95 * Additional variables for this implementation.
96 */
97/* receive variables */
98 tcp_seq rcv_adv; /* advertised window */
99/* retransmit variables */
100 tcp_seq snd_max; /* highest sequence number sent;
101 * used to recognize retransmits
102 */
103/* congestion control (for slow start, source quench, retransmit after loss) */
104 u_long snd_cwnd; /* congestion-controlled window */
105 u_long snd_ssthresh; /* snd_cwnd size threshhold for
106 * for slow start exponential to
107 * linear switch
108 */
109/*
110 * transmit timing stuff. See below for scale of srtt and rttvar.
111 * "Variance" is actually smoothed difference.
112 */
113 u_int t_idle; /* inactivity time */
114 int t_rtt; /* round trip time */
115 tcp_seq t_rtseq; /* sequence number being timed */
116 int t_srtt; /* smoothed round-trip time */
117 int t_rttvar; /* variance in round-trip time */
118 u_int t_rttmin; /* minimum rtt allowed */
119 u_long max_sndwnd; /* largest window peer has offered */
120
121/* out-of-band data */
122 char t_oobflags; /* have some */
123 char t_iobc; /* input character */
124#define TCPOOB_HAVEDATA 0x01
125#define TCPOOB_HADDATA 0x02
126 int t_softerror; /* possible error not yet reported */
127
128/* RFC 1323 variables */
129 u_char snd_scale; /* window scaling for send window */
130 u_char rcv_scale; /* window scaling for recv window */
131 u_char request_r_scale; /* pending window scaling */
132 u_char requested_s_scale;
133 u_long ts_recent; /* timestamp echo data */
134 u_long ts_recent_age; /* when last updated */
135 tcp_seq last_ack_sent;
136/* RFC 1644 variables */
137 tcp_cc cc_send; /* send connection count */
138 tcp_cc cc_recv; /* receive connection count */
139 u_long t_duration; /* connection duration */
140
141/* TUBA stuff */
142 caddr_t t_tuba_pcb; /* next level down pcb for TCP over z */
143/* More RTT stuff */
144 u_long t_rttupdated; /* number of times rtt sampled */
145};
146
147/*
148 * Structure to hold TCP options that are only used during segment
149 * processing (in tcp_input), but not held in the tcpcb.
150 * It's basically used to reduce the number of parameters
151 * to tcp_dooptions.
152 */
153struct tcpopt {
154 u_long to_flag; /* which options are present */
155#define TOF_TS 0x0001 /* timestamp */
156#define TOF_CC 0x0002 /* CC and CCnew are exclusive */
157#define TOF_CCNEW 0x0004
158#define TOF_CCECHO 0x0008
159 u_long to_tsval;
160 u_long to_tsecr;
161 tcp_cc to_cc; /* holds CC or CCnew */
162 tcp_cc to_ccecho;
163};
164
165/*
166 * The TAO cache entry which is stored in the protocol family specific
167 * portion of the route metrics.
168 */
169struct rmxp_tao {
170 tcp_cc tao_cc; /* latest CC in valid SYN */
171 tcp_cc tao_ccsent; /* latest CC sent to peer */
172 u_short tao_mssopt; /* peer's cached MSS */
173#ifdef notyet
174 u_short tao_flags; /* cache status flags */
175#define TAOF_DONT 0x0001 /* peer doesn't understand rfc1644 */
176#define TAOF_OK 0x0002 /* peer does understand rfc1644 */
177#define TAOF_UNDEF 0 /* we don't know yet */
178#endif /* notyet */
179};
180#define rmx_taop(r) ((struct rmxp_tao *)(r).rmx_filler)
181
182#define intotcpcb(ip) ((struct tcpcb *)(ip)->inp_ppcb)
183#define sototcpcb(so) (intotcpcb(sotoinpcb(so)))
184
185/*
186 * The smoothed round-trip time and estimated variance
187 * are stored as fixed point numbers scaled by the values below.
188 * For convenience, these scales are also used in smoothing the average
189 * (smoothed = (1/scale)sample + ((scale-1)/scale)smoothed).
190 * With these scales, srtt has 3 bits to the right of the binary point,
191 * and thus an "ALPHA" of 0.875. rttvar has 2 bits to the right of the
192 * binary point, and is smoothed with an ALPHA of 0.75.
193 */
194#define TCP_RTT_SCALE 8 /* multiplier for srtt; 3 bits frac. */
195#define TCP_RTT_SHIFT 3 /* shift for srtt; 3 bits frac. */
196#define TCP_RTTVAR_SCALE 4 /* multiplier for rttvar; 2 bits */
197#define TCP_RTTVAR_SHIFT 2 /* shift for rttvar; 2 bits */
198
199/*
200 * The initial retransmission should happen at rtt + 4 * rttvar.
201 * Because of the way we do the smoothing, srtt and rttvar
202 * will each average +1/2 tick of bias. When we compute
203 * the retransmit timer, we want 1/2 tick of rounding and
204 * 1 extra tick because of +-1/2 tick uncertainty in the
205 * firing of the timer. The bias will give us exactly the
206 * 1.5 tick we need. But, because the bias is
207 * statistical, we have to test that we don't drop below
208 * the minimum feasible timer (which is 2 ticks).
209 * This macro assumes that the value of TCP_RTTVAR_SCALE
210 * is the same as the multiplier for rttvar.
211 */
212#define TCP_REXMTVAL(tp) \
213 (((tp)->t_srtt >> TCP_RTT_SHIFT) + (tp)->t_rttvar)
214
215/* XXX
216 * We want to avoid doing m_pullup on incoming packets but that
217 * means avoiding dtom on the tcp reassembly code. That in turn means
218 * keeping an mbuf pointer in the reassembly queue (since we might
219 * have a cluster). As a quick hack, the source & destination
220 * port numbers (which are no longer needed once we've located the
221 * tcpcb) are overlayed with an mbuf pointer.
222 */
223#define REASS_MBUF(ti) (*(struct mbuf **)&((ti)->ti_t))
224
225/*
226 * TCP statistics.
227 * Many of these should be kept per connection,
228 * but that's inconvenient at the moment.
229 */
230struct tcpstat {
231 u_long tcps_connattempt; /* connections initiated */
232 u_long tcps_accepts; /* connections accepted */
233 u_long tcps_connects; /* connections established */
234 u_long tcps_drops; /* connections dropped */
235 u_long tcps_conndrops; /* embryonic connections dropped */
236 u_long tcps_closed; /* conn. closed (includes drops) */
237 u_long tcps_segstimed; /* segs where we tried to get rtt */
238 u_long tcps_rttupdated; /* times we succeeded */
239 u_long tcps_delack; /* delayed acks sent */
240 u_long tcps_timeoutdrop; /* conn. dropped in rxmt timeout */
241 u_long tcps_rexmttimeo; /* retransmit timeouts */
242 u_long tcps_persisttimeo; /* persist timeouts */
243 u_long tcps_keeptimeo; /* keepalive timeouts */
244 u_long tcps_keepprobe; /* keepalive probes sent */
245 u_long tcps_keepdrops; /* connections dropped in keepalive */
246
247 u_long tcps_sndtotal; /* total packets sent */
248 u_long tcps_sndpack; /* data packets sent */
249 u_long tcps_sndbyte; /* data bytes sent */
250 u_long tcps_sndrexmitpack; /* data packets retransmitted */
251 u_long tcps_sndrexmitbyte; /* data bytes retransmitted */
252 u_long tcps_sndacks; /* ack-only packets sent */
253 u_long tcps_sndprobe; /* window probes sent */
254 u_long tcps_sndurg; /* packets sent with URG only */
255 u_long tcps_sndwinup; /* window update-only packets sent */
256 u_long tcps_sndctrl; /* control (SYN|FIN|RST) packets sent */
257
258 u_long tcps_rcvtotal; /* total packets received */
259 u_long tcps_rcvpack; /* packets received in sequence */
260 u_long tcps_rcvbyte; /* bytes received in sequence */
261 u_long tcps_rcvbadsum; /* packets received with ccksum errs */
262 u_long tcps_rcvbadoff; /* packets received with bad offset */
263 u_long tcps_rcvshort; /* packets received too short */
264 u_long tcps_rcvduppack; /* duplicate-only packets received */
265 u_long tcps_rcvdupbyte; /* duplicate-only bytes received */
266 u_long tcps_rcvpartduppack; /* packets with some duplicate data */
267 u_long tcps_rcvpartdupbyte; /* dup. bytes in part-dup. packets */
268 u_long tcps_rcvoopack; /* out-of-order packets received */
269 u_long tcps_rcvoobyte; /* out-of-order bytes received */
270 u_long tcps_rcvpackafterwin; /* packets with data after window */
271 u_long tcps_rcvbyteafterwin; /* bytes rcvd after window */
272 u_long tcps_rcvafterclose; /* packets rcvd after "close" */
273 u_long tcps_rcvwinprobe; /* rcvd window probe packets */
274 u_long tcps_rcvdupack; /* rcvd duplicate acks */
275 u_long tcps_rcvacktoomuch; /* rcvd acks for unsent data */
276 u_long tcps_rcvackpack; /* rcvd ack packets */
277 u_long tcps_rcvackbyte; /* bytes acked by rcvd acks */
278 u_long tcps_rcvwinupd; /* rcvd window update packets */
279 u_long tcps_pawsdrop; /* segments dropped due to PAWS */
280 u_long tcps_predack; /* times hdr predict ok for acks */
281 u_long tcps_preddat; /* times hdr predict ok for data pkts */
282 u_long tcps_pcbcachemiss;
283 u_long tcps_cachedrtt; /* times cached RTT in route updated */
284 u_long tcps_cachedrttvar; /* times cached rttvar updated */
285 u_long tcps_cachedssthresh; /* times cached ssthresh updated */
286 u_long tcps_usedrtt; /* times RTT initialized from route */
287 u_long tcps_usedrttvar; /* times RTTVAR initialized from rt */
288 u_long tcps_usedssthresh; /* times ssthresh initialized from rt*/
289 u_long tcps_persistdrop; /* timeout in persist state */
290 u_long tcps_badsyn; /* bogus SYN, e.g. premature ACK */
291 u_long tcps_mturesent; /* resends due to MTU discovery */
292};
293
294/*
295 * Names for TCP sysctl objects
296 */
297#define TCPCTL_DO_RFC1323 1 /* use RFC-1323 extensions */
298#define TCPCTL_DO_RFC1644 2 /* use RFC-1644 extensions */
299#define TCPCTL_MSSDFLT 3 /* MSS default */
300#define TCPCTL_STATS 4 /* statistics (read-only) */
301#define TCPCTL_RTTDFLT 5 /* default RTT estimate */
302#define TCPCTL_KEEPIDLE 6 /* keepalive idle timer */
303#define TCPCTL_KEEPINTVL 7 /* interval to send keepalives */
304#define TCPCTL_SENDSPACE 8 /* send buffer space */
305#define TCPCTL_RECVSPACE 9 /* receive buffer space */
306#define TCPCTL_MAXID 10
307
308#define TCPCTL_NAMES { \
309 { 0, 0 }, \
310 { "rfc1323", CTLTYPE_INT }, \
311 { "rfc1644", CTLTYPE_INT }, \
312 { "mssdflt", CTLTYPE_INT }, \
313 { "stats", CTLTYPE_STRUCT }, \
314 { "rttdflt", CTLTYPE_INT }, \
315 { "keepidle", CTLTYPE_INT }, \
316 { "keepintvl", CTLTYPE_INT }, \
317 { "sendspace", CTLTYPE_INT }, \
318 { "recvspace", CTLTYPE_INT }, \
319}
320
321#ifdef KERNEL
322extern struct inpcbhead tcb; /* head of queue of active tcpcb's */
323extern struct inpcbinfo tcbinfo;
324extern struct tcpstat tcpstat; /* tcp statistics */
325extern int tcp_do_rfc1323; /* XXX */
326extern int tcp_do_rfc1644; /* XXX */
327extern int tcp_mssdflt; /* XXX */
328extern u_long tcp_now; /* for RFC 1323 timestamps */
329extern int tcp_rttdflt; /* XXX */
330extern u_short tcp_lastport; /* last assigned port */
331
332void tcp_canceltimers __P((struct tcpcb *));
333struct tcpcb *
334 tcp_close __P((struct tcpcb *));
335void tcp_ctlinput __P((int, struct sockaddr *, struct ip *));
336int tcp_ctloutput __P((int, struct socket *, int, int, struct mbuf **));
337struct tcpcb *
338 tcp_drop __P((struct tcpcb *, int));
339void tcp_drain __P((void));
340void tcp_fasttimo __P((void));
341struct rmxp_tao *
342 tcp_gettaocache __P((struct inpcb *));
343void tcp_init __P((void));
344void tcp_input __P((struct mbuf *, int));
345void tcp_mss __P((struct tcpcb *, int));
346int tcp_mssopt __P((struct tcpcb *));
347void tcp_mtudisc __P((struct inpcb *, int));
348struct tcpcb *
349 tcp_newtcpcb __P((struct inpcb *));
350int tcp_output __P((struct tcpcb *));
351void tcp_quench __P((struct inpcb *, int));
352void tcp_respond __P((struct tcpcb *,
353 struct tcpiphdr *, struct mbuf *, u_long, u_long, int));
354struct rtentry *
355 tcp_rtlookup __P((struct inpcb *));
356void tcp_setpersist __P((struct tcpcb *));
357void tcp_slowtimo __P((void));
358struct tcpiphdr *
359 tcp_template __P((struct tcpcb *));
360struct tcpcb *
361 tcp_timers __P((struct tcpcb *, int));
362void tcp_trace __P((int, int, struct tcpcb *, struct tcpiphdr *, int));
363int tcp_usrreq __P((struct socket *,
364 int, struct mbuf *, struct mbuf *, struct mbuf *));
365
366extern u_long tcp_sendspace;
367extern u_long tcp_recvspace;
368
369#endif /* KERNEL */
370
371#endif /* _NETINET_TCP_VAR_H_ */