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1 | /* |
2 | * Copyright (c) 1982, 1986, 1993, 1994 | |
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 8.3 (Berkeley) 4/10/94 | |
34 | * tcp_var.h,v 1.3 1994/08/21 05:27:39 paul Exp | |
35 | */ | |
36 | ||
37 | #ifndef _TCP_VAR_H_ | |
38 | #define _TCP_VAR_H_ | |
39 | ||
40 | #include "tcpip.h" | |
41 | #include "tcp_timer.h" | |
42 | ||
f0cbd3ec FB |
43 | /* |
44 | * Tcp control block, one per tcp; fields: | |
45 | */ | |
46 | struct tcpcb { | |
429d0a3d BS |
47 | struct tcpiphdr *seg_next; /* sequencing queue */ |
48 | struct tcpiphdr *seg_prev; | |
f0cbd3ec FB |
49 | short t_state; /* state of this connection */ |
50 | short t_timer[TCPT_NTIMERS]; /* tcp timers */ | |
51 | short t_rxtshift; /* log(2) of rexmt exp. backoff */ | |
52 | short t_rxtcur; /* current retransmit value */ | |
53 | short t_dupacks; /* consecutive dup acks recd */ | |
54 | u_short t_maxseg; /* maximum segment size */ | |
55 | char t_force; /* 1 if forcing out a byte */ | |
56 | u_short t_flags; | |
57 | #define TF_ACKNOW 0x0001 /* ack peer immediately */ | |
58 | #define TF_DELACK 0x0002 /* ack, but try to delay it */ | |
59 | #define TF_NODELAY 0x0004 /* don't delay packets to coalesce */ | |
60 | #define TF_NOOPT 0x0008 /* don't use tcp options */ | |
61 | #define TF_SENTFIN 0x0010 /* have sent FIN */ | |
62 | #define TF_REQ_SCALE 0x0020 /* have/will request window scaling */ | |
63 | #define TF_RCVD_SCALE 0x0040 /* other side has requested scaling */ | |
64 | #define TF_REQ_TSTMP 0x0080 /* have/will request timestamps */ | |
65 | #define TF_RCVD_TSTMP 0x0100 /* a timestamp was received in SYN */ | |
66 | #define TF_SACK_PERMIT 0x0200 /* other side said I could SACK */ | |
67 | ||
68 | /* Make it static for now */ | |
69 | /* struct tcpiphdr *t_template; / * skeletal packet for transmit */ | |
70 | struct tcpiphdr t_template; | |
71 | ||
72 | struct socket *t_socket; /* back pointer to socket */ | |
73 | /* | |
74 | * The following fields are used as in the protocol specification. | |
75 | * See RFC783, Dec. 1981, page 21. | |
76 | */ | |
77 | /* send sequence variables */ | |
78 | tcp_seq snd_una; /* send unacknowledged */ | |
79 | tcp_seq snd_nxt; /* send next */ | |
80 | tcp_seq snd_up; /* send urgent pointer */ | |
81 | tcp_seq snd_wl1; /* window update seg seq number */ | |
82 | tcp_seq snd_wl2; /* window update seg ack number */ | |
83 | tcp_seq iss; /* initial send sequence number */ | |
84 | u_int32_t snd_wnd; /* send window */ | |
85 | /* receive sequence variables */ | |
86 | u_int32_t rcv_wnd; /* receive window */ | |
87 | tcp_seq rcv_nxt; /* receive next */ | |
88 | tcp_seq rcv_up; /* receive urgent pointer */ | |
89 | tcp_seq irs; /* initial receive sequence number */ | |
90 | /* | |
91 | * Additional variables for this implementation. | |
92 | */ | |
93 | /* receive variables */ | |
94 | tcp_seq rcv_adv; /* advertised window */ | |
95 | /* retransmit variables */ | |
96 | tcp_seq snd_max; /* highest sequence number sent; | |
97 | * used to recognize retransmits | |
98 | */ | |
99 | /* congestion control (for slow start, source quench, retransmit after loss) */ | |
100 | u_int32_t snd_cwnd; /* congestion-controlled window */ | |
101 | u_int32_t snd_ssthresh; /* snd_cwnd size threshold for | |
102 | * for slow start exponential to | |
103 | * linear switch | |
104 | */ | |
105 | /* | |
106 | * transmit timing stuff. See below for scale of srtt and rttvar. | |
107 | * "Variance" is actually smoothed difference. | |
108 | */ | |
109 | short t_idle; /* inactivity time */ | |
110 | short t_rtt; /* round trip time */ | |
111 | tcp_seq t_rtseq; /* sequence number being timed */ | |
112 | short t_srtt; /* smoothed round-trip time */ | |
113 | short t_rttvar; /* variance in round-trip time */ | |
114 | u_short t_rttmin; /* minimum rtt allowed */ | |
115 | u_int32_t max_sndwnd; /* largest window peer has offered */ | |
116 | ||
117 | /* out-of-band data */ | |
118 | char t_oobflags; /* have some */ | |
119 | char t_iobc; /* input character */ | |
120 | #define TCPOOB_HAVEDATA 0x01 | |
121 | #define TCPOOB_HADDATA 0x02 | |
122 | short t_softerror; /* possible error not yet reported */ | |
123 | ||
124 | /* RFC 1323 variables */ | |
125 | u_char snd_scale; /* window scaling for send window */ | |
126 | u_char rcv_scale; /* window scaling for recv window */ | |
127 | u_char request_r_scale; /* pending window scaling */ | |
128 | u_char requested_s_scale; | |
129 | u_int32_t ts_recent; /* timestamp echo data */ | |
130 | u_int32_t ts_recent_age; /* when last updated */ | |
131 | tcp_seq last_ack_sent; | |
132 | ||
133 | }; | |
134 | ||
135 | #define sototcpcb(so) ((so)->so_tcpcb) | |
136 | ||
137 | /* | |
138 | * The smoothed round-trip time and estimated variance | |
139 | * are stored as fixed point numbers scaled by the values below. | |
140 | * For convenience, these scales are also used in smoothing the average | |
141 | * (smoothed = (1/scale)sample + ((scale-1)/scale)smoothed). | |
142 | * With these scales, srtt has 3 bits to the right of the binary point, | |
143 | * and thus an "ALPHA" of 0.875. rttvar has 2 bits to the right of the | |
144 | * binary point, and is smoothed with an ALPHA of 0.75. | |
145 | */ | |
146 | #define TCP_RTT_SCALE 8 /* multiplier for srtt; 3 bits frac. */ | |
147 | #define TCP_RTT_SHIFT 3 /* shift for srtt; 3 bits frac. */ | |
148 | #define TCP_RTTVAR_SCALE 4 /* multiplier for rttvar; 2 bits */ | |
149 | #define TCP_RTTVAR_SHIFT 2 /* multiplier for rttvar; 2 bits */ | |
150 | ||
151 | /* | |
152 | * The initial retransmission should happen at rtt + 4 * rttvar. | |
153 | * Because of the way we do the smoothing, srtt and rttvar | |
154 | * will each average +1/2 tick of bias. When we compute | |
155 | * the retransmit timer, we want 1/2 tick of rounding and | |
156 | * 1 extra tick because of +-1/2 tick uncertainty in the | |
157 | * firing of the timer. The bias will give us exactly the | |
158 | * 1.5 tick we need. But, because the bias is | |
159 | * statistical, we have to test that we don't drop below | |
160 | * the minimum feasible timer (which is 2 ticks). | |
161 | * This macro assumes that the value of TCP_RTTVAR_SCALE | |
162 | * is the same as the multiplier for rttvar. | |
163 | */ | |
164 | #define TCP_REXMTVAL(tp) \ | |
165 | (((tp)->t_srtt >> TCP_RTT_SHIFT) + (tp)->t_rttvar) | |
166 | ||
31a60e22 | 167 | #ifdef LOG_ENABLED |
f0cbd3ec FB |
168 | /* |
169 | * TCP statistics. | |
170 | * Many of these should be kept per connection, | |
171 | * but that's inconvenient at the moment. | |
172 | */ | |
173 | struct tcpstat { | |
174 | u_long tcps_connattempt; /* connections initiated */ | |
175 | u_long tcps_accepts; /* connections accepted */ | |
176 | u_long tcps_connects; /* connections established */ | |
177 | u_long tcps_drops; /* connections dropped */ | |
178 | u_long tcps_conndrops; /* embryonic connections dropped */ | |
179 | u_long tcps_closed; /* conn. closed (includes drops) */ | |
180 | u_long tcps_segstimed; /* segs where we tried to get rtt */ | |
181 | u_long tcps_rttupdated; /* times we succeeded */ | |
182 | u_long tcps_delack; /* delayed acks sent */ | |
183 | u_long tcps_timeoutdrop; /* conn. dropped in rxmt timeout */ | |
184 | u_long tcps_rexmttimeo; /* retransmit timeouts */ | |
185 | u_long tcps_persisttimeo; /* persist timeouts */ | |
186 | u_long tcps_keeptimeo; /* keepalive timeouts */ | |
187 | u_long tcps_keepprobe; /* keepalive probes sent */ | |
188 | u_long tcps_keepdrops; /* connections dropped in keepalive */ | |
189 | ||
190 | u_long tcps_sndtotal; /* total packets sent */ | |
191 | u_long tcps_sndpack; /* data packets sent */ | |
192 | u_long tcps_sndbyte; /* data bytes sent */ | |
193 | u_long tcps_sndrexmitpack; /* data packets retransmitted */ | |
194 | u_long tcps_sndrexmitbyte; /* data bytes retransmitted */ | |
195 | u_long tcps_sndacks; /* ack-only packets sent */ | |
196 | u_long tcps_sndprobe; /* window probes sent */ | |
197 | u_long tcps_sndurg; /* packets sent with URG only */ | |
198 | u_long tcps_sndwinup; /* window update-only packets sent */ | |
199 | u_long tcps_sndctrl; /* control (SYN|FIN|RST) packets sent */ | |
200 | ||
201 | u_long tcps_rcvtotal; /* total packets received */ | |
202 | u_long tcps_rcvpack; /* packets received in sequence */ | |
203 | u_long tcps_rcvbyte; /* bytes received in sequence */ | |
204 | u_long tcps_rcvbadsum; /* packets received with ccksum errs */ | |
205 | u_long tcps_rcvbadoff; /* packets received with bad offset */ | |
206 | /* u_long tcps_rcvshort; */ /* packets received too short */ | |
207 | u_long tcps_rcvduppack; /* duplicate-only packets received */ | |
208 | u_long tcps_rcvdupbyte; /* duplicate-only bytes received */ | |
209 | u_long tcps_rcvpartduppack; /* packets with some duplicate data */ | |
210 | u_long tcps_rcvpartdupbyte; /* dup. bytes in part-dup. packets */ | |
211 | u_long tcps_rcvoopack; /* out-of-order packets received */ | |
212 | u_long tcps_rcvoobyte; /* out-of-order bytes received */ | |
213 | u_long tcps_rcvpackafterwin; /* packets with data after window */ | |
214 | u_long tcps_rcvbyteafterwin; /* bytes rcvd after window */ | |
215 | u_long tcps_rcvafterclose; /* packets rcvd after "close" */ | |
216 | u_long tcps_rcvwinprobe; /* rcvd window probe packets */ | |
217 | u_long tcps_rcvdupack; /* rcvd duplicate acks */ | |
218 | u_long tcps_rcvacktoomuch; /* rcvd acks for unsent data */ | |
219 | u_long tcps_rcvackpack; /* rcvd ack packets */ | |
220 | u_long tcps_rcvackbyte; /* bytes acked by rcvd acks */ | |
221 | u_long tcps_rcvwinupd; /* rcvd window update packets */ | |
222 | /* u_long tcps_pawsdrop; */ /* segments dropped due to PAWS */ | |
223 | u_long tcps_predack; /* times hdr predict ok for acks */ | |
224 | u_long tcps_preddat; /* times hdr predict ok for data pkts */ | |
225 | u_long tcps_socachemiss; /* tcp_last_so misses */ | |
226 | u_long tcps_didnuttin; /* Times tcp_output didn't do anything XXX */ | |
227 | }; | |
228 | ||
229 | extern struct tcpstat tcpstat; /* tcp statistics */ | |
31a60e22 BS |
230 | #endif |
231 | ||
f0cbd3ec FB |
232 | extern u_int32_t tcp_now; /* for RFC 1323 timestamps */ |
233 | ||
234 | #endif |