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1.1 root 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.
1.1.1.3 ! root 13: * 3. Neither the name of the University nor the names of its contributors
1.1 root 14: * may be used to endorse or promote products derived from this software
15: * without specific prior written permission.
16: *
17: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27: * SUCH DAMAGE.
28: *
29: * @(#)tcp_var.h 8.3 (Berkeley) 4/10/94
30: * tcp_var.h,v 1.3 1994/08/21 05:27:39 paul Exp
31: */
32:
33: #ifndef _TCP_VAR_H_
34: #define _TCP_VAR_H_
35:
36: #include "tcpip.h"
37: #include "tcp_timer.h"
38:
39: /*
40: * Tcp control block, one per tcp; fields:
41: */
42: struct tcpcb {
1.1.1.3 ! root 43: struct tcpiphdr *seg_next; /* sequencing queue */
! 44: struct tcpiphdr *seg_prev;
1.1 root 45: short t_state; /* state of this connection */
46: short t_timer[TCPT_NTIMERS]; /* tcp timers */
47: short t_rxtshift; /* log(2) of rexmt exp. backoff */
48: short t_rxtcur; /* current retransmit value */
49: short t_dupacks; /* consecutive dup acks recd */
50: u_short t_maxseg; /* maximum segment size */
51: char t_force; /* 1 if forcing out a byte */
52: u_short t_flags;
53: #define TF_ACKNOW 0x0001 /* ack peer immediately */
54: #define TF_DELACK 0x0002 /* ack, but try to delay it */
55: #define TF_NODELAY 0x0004 /* don't delay packets to coalesce */
56: #define TF_NOOPT 0x0008 /* don't use tcp options */
57: #define TF_SENTFIN 0x0010 /* have sent FIN */
58: #define TF_REQ_SCALE 0x0020 /* have/will request window scaling */
59: #define TF_RCVD_SCALE 0x0040 /* other side has requested scaling */
60: #define TF_REQ_TSTMP 0x0080 /* have/will request timestamps */
61: #define TF_RCVD_TSTMP 0x0100 /* a timestamp was received in SYN */
62: #define TF_SACK_PERMIT 0x0200 /* other side said I could SACK */
63:
64: /* Make it static for now */
65: /* struct tcpiphdr *t_template; / * skeletal packet for transmit */
66: struct tcpiphdr t_template;
67:
68: struct socket *t_socket; /* back pointer to socket */
69: /*
70: * The following fields are used as in the protocol specification.
71: * See RFC783, Dec. 1981, page 21.
72: */
73: /* send sequence variables */
74: tcp_seq snd_una; /* send unacknowledged */
75: tcp_seq snd_nxt; /* send next */
76: tcp_seq snd_up; /* send urgent pointer */
77: tcp_seq snd_wl1; /* window update seg seq number */
78: tcp_seq snd_wl2; /* window update seg ack number */
79: tcp_seq iss; /* initial send sequence number */
80: u_int32_t snd_wnd; /* send window */
81: /* receive sequence variables */
82: u_int32_t rcv_wnd; /* receive window */
83: tcp_seq rcv_nxt; /* receive next */
84: tcp_seq rcv_up; /* receive urgent pointer */
85: tcp_seq irs; /* initial receive sequence number */
86: /*
87: * Additional variables for this implementation.
88: */
89: /* receive variables */
90: tcp_seq rcv_adv; /* advertised window */
91: /* retransmit variables */
92: tcp_seq snd_max; /* highest sequence number sent;
93: * used to recognize retransmits
94: */
95: /* congestion control (for slow start, source quench, retransmit after loss) */
96: u_int32_t snd_cwnd; /* congestion-controlled window */
97: u_int32_t snd_ssthresh; /* snd_cwnd size threshold for
98: * for slow start exponential to
99: * linear switch
100: */
101: /*
102: * transmit timing stuff. See below for scale of srtt and rttvar.
103: * "Variance" is actually smoothed difference.
104: */
105: short t_idle; /* inactivity time */
106: short t_rtt; /* round trip time */
107: tcp_seq t_rtseq; /* sequence number being timed */
108: short t_srtt; /* smoothed round-trip time */
109: short t_rttvar; /* variance in round-trip time */
110: u_short t_rttmin; /* minimum rtt allowed */
111: u_int32_t max_sndwnd; /* largest window peer has offered */
112:
113: /* out-of-band data */
114: char t_oobflags; /* have some */
115: char t_iobc; /* input character */
116: #define TCPOOB_HAVEDATA 0x01
117: #define TCPOOB_HADDATA 0x02
118: short t_softerror; /* possible error not yet reported */
119:
120: /* RFC 1323 variables */
121: u_char snd_scale; /* window scaling for send window */
122: u_char rcv_scale; /* window scaling for recv window */
123: u_char request_r_scale; /* pending window scaling */
124: u_char requested_s_scale;
125: u_int32_t ts_recent; /* timestamp echo data */
126: u_int32_t ts_recent_age; /* when last updated */
127: tcp_seq last_ack_sent;
128:
129: };
130:
131: #define sototcpcb(so) ((so)->so_tcpcb)
132:
133: /*
134: * The smoothed round-trip time and estimated variance
135: * are stored as fixed point numbers scaled by the values below.
136: * For convenience, these scales are also used in smoothing the average
137: * (smoothed = (1/scale)sample + ((scale-1)/scale)smoothed).
138: * With these scales, srtt has 3 bits to the right of the binary point,
139: * and thus an "ALPHA" of 0.875. rttvar has 2 bits to the right of the
140: * binary point, and is smoothed with an ALPHA of 0.75.
141: */
142: #define TCP_RTT_SCALE 8 /* multiplier for srtt; 3 bits frac. */
143: #define TCP_RTT_SHIFT 3 /* shift for srtt; 3 bits frac. */
144: #define TCP_RTTVAR_SCALE 4 /* multiplier for rttvar; 2 bits */
145: #define TCP_RTTVAR_SHIFT 2 /* multiplier for rttvar; 2 bits */
146:
147: /*
148: * The initial retransmission should happen at rtt + 4 * rttvar.
149: * Because of the way we do the smoothing, srtt and rttvar
150: * will each average +1/2 tick of bias. When we compute
151: * the retransmit timer, we want 1/2 tick of rounding and
152: * 1 extra tick because of +-1/2 tick uncertainty in the
153: * firing of the timer. The bias will give us exactly the
154: * 1.5 tick we need. But, because the bias is
155: * statistical, we have to test that we don't drop below
156: * the minimum feasible timer (which is 2 ticks).
157: * This macro assumes that the value of TCP_RTTVAR_SCALE
158: * is the same as the multiplier for rttvar.
159: */
160: #define TCP_REXMTVAL(tp) \
161: (((tp)->t_srtt >> TCP_RTT_SHIFT) + (tp)->t_rttvar)
162:
1.1.1.2 root 163: #ifdef LOG_ENABLED
1.1 root 164: /*
165: * TCP statistics.
166: * Many of these should be kept per connection,
167: * but that's inconvenient at the moment.
168: */
169: struct tcpstat {
170: u_long tcps_connattempt; /* connections initiated */
171: u_long tcps_accepts; /* connections accepted */
172: u_long tcps_connects; /* connections established */
173: u_long tcps_drops; /* connections dropped */
174: u_long tcps_conndrops; /* embryonic connections dropped */
175: u_long tcps_closed; /* conn. closed (includes drops) */
176: u_long tcps_segstimed; /* segs where we tried to get rtt */
177: u_long tcps_rttupdated; /* times we succeeded */
178: u_long tcps_delack; /* delayed acks sent */
179: u_long tcps_timeoutdrop; /* conn. dropped in rxmt timeout */
180: u_long tcps_rexmttimeo; /* retransmit timeouts */
181: u_long tcps_persisttimeo; /* persist timeouts */
182: u_long tcps_keeptimeo; /* keepalive timeouts */
183: u_long tcps_keepprobe; /* keepalive probes sent */
184: u_long tcps_keepdrops; /* connections dropped in keepalive */
185:
186: u_long tcps_sndtotal; /* total packets sent */
187: u_long tcps_sndpack; /* data packets sent */
188: u_long tcps_sndbyte; /* data bytes sent */
189: u_long tcps_sndrexmitpack; /* data packets retransmitted */
190: u_long tcps_sndrexmitbyte; /* data bytes retransmitted */
191: u_long tcps_sndacks; /* ack-only packets sent */
192: u_long tcps_sndprobe; /* window probes sent */
193: u_long tcps_sndurg; /* packets sent with URG only */
194: u_long tcps_sndwinup; /* window update-only packets sent */
195: u_long tcps_sndctrl; /* control (SYN|FIN|RST) packets sent */
196:
197: u_long tcps_rcvtotal; /* total packets received */
198: u_long tcps_rcvpack; /* packets received in sequence */
199: u_long tcps_rcvbyte; /* bytes received in sequence */
200: u_long tcps_rcvbadsum; /* packets received with ccksum errs */
201: u_long tcps_rcvbadoff; /* packets received with bad offset */
202: /* u_long tcps_rcvshort; */ /* packets received too short */
203: u_long tcps_rcvduppack; /* duplicate-only packets received */
204: u_long tcps_rcvdupbyte; /* duplicate-only bytes received */
205: u_long tcps_rcvpartduppack; /* packets with some duplicate data */
206: u_long tcps_rcvpartdupbyte; /* dup. bytes in part-dup. packets */
207: u_long tcps_rcvoopack; /* out-of-order packets received */
208: u_long tcps_rcvoobyte; /* out-of-order bytes received */
209: u_long tcps_rcvpackafterwin; /* packets with data after window */
210: u_long tcps_rcvbyteafterwin; /* bytes rcvd after window */
211: u_long tcps_rcvafterclose; /* packets rcvd after "close" */
212: u_long tcps_rcvwinprobe; /* rcvd window probe packets */
213: u_long tcps_rcvdupack; /* rcvd duplicate acks */
214: u_long tcps_rcvacktoomuch; /* rcvd acks for unsent data */
215: u_long tcps_rcvackpack; /* rcvd ack packets */
216: u_long tcps_rcvackbyte; /* bytes acked by rcvd acks */
217: u_long tcps_rcvwinupd; /* rcvd window update packets */
218: /* u_long tcps_pawsdrop; */ /* segments dropped due to PAWS */
219: u_long tcps_predack; /* times hdr predict ok for acks */
220: u_long tcps_preddat; /* times hdr predict ok for data pkts */
221: u_long tcps_socachemiss; /* tcp_last_so misses */
222: u_long tcps_didnuttin; /* Times tcp_output didn't do anything XXX */
223: };
224:
225: extern struct tcpstat tcpstat; /* tcp statistics */
1.1.1.2 root 226: #endif
227:
1.1 root 228: extern u_int32_t tcp_now; /* for RFC 1323 timestamps */
229:
230: #endif
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