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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.
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:
43: #if SIZEOF_CHAR_P == 4
44: typedef struct tcpiphdr *tcpiphdrp_32;
45: #else
46: typedef u_int32_t tcpiphdrp_32;
47: #endif
48:
49: /*
50: * Tcp control block, one per tcp; fields:
51: */
52: struct tcpcb {
53: tcpiphdrp_32 seg_next; /* sequencing queue */
54: tcpiphdrp_32 seg_prev;
55: short t_state; /* state of this connection */
56: short t_timer[TCPT_NTIMERS]; /* tcp timers */
57: short t_rxtshift; /* log(2) of rexmt exp. backoff */
58: short t_rxtcur; /* current retransmit value */
59: short t_dupacks; /* consecutive dup acks recd */
60: u_short t_maxseg; /* maximum segment size */
61: char t_force; /* 1 if forcing out a byte */
62: u_short t_flags;
63: #define TF_ACKNOW 0x0001 /* ack peer immediately */
64: #define TF_DELACK 0x0002 /* ack, but try to delay it */
65: #define TF_NODELAY 0x0004 /* don't delay packets to coalesce */
66: #define TF_NOOPT 0x0008 /* don't use tcp options */
67: #define TF_SENTFIN 0x0010 /* have sent FIN */
68: #define TF_REQ_SCALE 0x0020 /* have/will request window scaling */
69: #define TF_RCVD_SCALE 0x0040 /* other side has requested scaling */
70: #define TF_REQ_TSTMP 0x0080 /* have/will request timestamps */
71: #define TF_RCVD_TSTMP 0x0100 /* a timestamp was received in SYN */
72: #define TF_SACK_PERMIT 0x0200 /* other side said I could SACK */
73:
74: /* Make it static for now */
75: /* struct tcpiphdr *t_template; / * skeletal packet for transmit */
76: struct tcpiphdr t_template;
77:
78: struct socket *t_socket; /* back pointer to socket */
79: /*
80: * The following fields are used as in the protocol specification.
81: * See RFC783, Dec. 1981, page 21.
82: */
83: /* send sequence variables */
84: tcp_seq snd_una; /* send unacknowledged */
85: tcp_seq snd_nxt; /* send next */
86: tcp_seq snd_up; /* send urgent pointer */
87: tcp_seq snd_wl1; /* window update seg seq number */
88: tcp_seq snd_wl2; /* window update seg ack number */
89: tcp_seq iss; /* initial send sequence number */
90: u_int32_t snd_wnd; /* send window */
91: /* receive sequence variables */
92: u_int32_t rcv_wnd; /* receive window */
93: tcp_seq rcv_nxt; /* receive next */
94: tcp_seq rcv_up; /* receive urgent pointer */
95: tcp_seq irs; /* initial receive sequence number */
96: /*
97: * Additional variables for this implementation.
98: */
99: /* receive variables */
100: tcp_seq rcv_adv; /* advertised window */
101: /* retransmit variables */
102: tcp_seq snd_max; /* highest sequence number sent;
103: * used to recognize retransmits
104: */
105: /* congestion control (for slow start, source quench, retransmit after loss) */
106: u_int32_t snd_cwnd; /* congestion-controlled window */
107: u_int32_t snd_ssthresh; /* snd_cwnd size threshold for
108: * for slow start exponential to
109: * linear switch
110: */
111: /*
112: * transmit timing stuff. See below for scale of srtt and rttvar.
113: * "Variance" is actually smoothed difference.
114: */
115: short t_idle; /* inactivity time */
116: short t_rtt; /* round trip time */
117: tcp_seq t_rtseq; /* sequence number being timed */
118: short t_srtt; /* smoothed round-trip time */
119: short t_rttvar; /* variance in round-trip time */
120: u_short t_rttmin; /* minimum rtt allowed */
121: u_int32_t max_sndwnd; /* largest window peer has offered */
122:
123: /* out-of-band data */
124: char t_oobflags; /* have some */
125: char t_iobc; /* input character */
126: #define TCPOOB_HAVEDATA 0x01
127: #define TCPOOB_HADDATA 0x02
128: short t_softerror; /* possible error not yet reported */
129:
130: /* RFC 1323 variables */
131: u_char snd_scale; /* window scaling for send window */
132: u_char rcv_scale; /* window scaling for recv window */
133: u_char request_r_scale; /* pending window scaling */
134: u_char requested_s_scale;
135: u_int32_t ts_recent; /* timestamp echo data */
136: u_int32_t ts_recent_age; /* when last updated */
137: tcp_seq last_ack_sent;
138:
139: };
140:
141: #define sototcpcb(so) ((so)->so_tcpcb)
142:
143: /*
144: * The smoothed round-trip time and estimated variance
145: * are stored as fixed point numbers scaled by the values below.
146: * For convenience, these scales are also used in smoothing the average
147: * (smoothed = (1/scale)sample + ((scale-1)/scale)smoothed).
148: * With these scales, srtt has 3 bits to the right of the binary point,
149: * and thus an "ALPHA" of 0.875. rttvar has 2 bits to the right of the
150: * binary point, and is smoothed with an ALPHA of 0.75.
151: */
152: #define TCP_RTT_SCALE 8 /* multiplier for srtt; 3 bits frac. */
153: #define TCP_RTT_SHIFT 3 /* shift for srtt; 3 bits frac. */
154: #define TCP_RTTVAR_SCALE 4 /* multiplier for rttvar; 2 bits */
155: #define TCP_RTTVAR_SHIFT 2 /* multiplier for rttvar; 2 bits */
156:
157: /*
158: * The initial retransmission should happen at rtt + 4 * rttvar.
159: * Because of the way we do the smoothing, srtt and rttvar
160: * will each average +1/2 tick of bias. When we compute
161: * the retransmit timer, we want 1/2 tick of rounding and
162: * 1 extra tick because of +-1/2 tick uncertainty in the
163: * firing of the timer. The bias will give us exactly the
164: * 1.5 tick we need. But, because the bias is
165: * statistical, we have to test that we don't drop below
166: * the minimum feasible timer (which is 2 ticks).
167: * This macro assumes that the value of TCP_RTTVAR_SCALE
168: * is the same as the multiplier for rttvar.
169: */
170: #define TCP_REXMTVAL(tp) \
171: (((tp)->t_srtt >> TCP_RTT_SHIFT) + (tp)->t_rttvar)
172:
173: /* XXX
174: * We want to avoid doing m_pullup on incoming packets but that
175: * means avoiding dtom on the tcp reassembly code. That in turn means
176: * keeping an mbuf pointer in the reassembly queue (since we might
177: * have a cluster). As a quick hack, the source & destination
178: * port numbers (which are no longer needed once we've located the
179: * tcpcb) are overlayed with an mbuf pointer.
180: */
181: #if SIZEOF_CHAR_P == 4
182: typedef struct mbuf *mbufp_32;
183: #else
184: typedef u_int32_t mbufp_32;
185: #endif
186: #define REASS_MBUF(ti) (*(mbufp_32 *)&((ti)->ti_t))
187:
188: /*
189: * TCP statistics.
190: * Many of these should be kept per connection,
191: * but that's inconvenient at the moment.
192: */
193: struct tcpstat {
194: u_long tcps_connattempt; /* connections initiated */
195: u_long tcps_accepts; /* connections accepted */
196: u_long tcps_connects; /* connections established */
197: u_long tcps_drops; /* connections dropped */
198: u_long tcps_conndrops; /* embryonic connections dropped */
199: u_long tcps_closed; /* conn. closed (includes drops) */
200: u_long tcps_segstimed; /* segs where we tried to get rtt */
201: u_long tcps_rttupdated; /* times we succeeded */
202: u_long tcps_delack; /* delayed acks sent */
203: u_long tcps_timeoutdrop; /* conn. dropped in rxmt timeout */
204: u_long tcps_rexmttimeo; /* retransmit timeouts */
205: u_long tcps_persisttimeo; /* persist timeouts */
206: u_long tcps_keeptimeo; /* keepalive timeouts */
207: u_long tcps_keepprobe; /* keepalive probes sent */
208: u_long tcps_keepdrops; /* connections dropped in keepalive */
209:
210: u_long tcps_sndtotal; /* total packets sent */
211: u_long tcps_sndpack; /* data packets sent */
212: u_long tcps_sndbyte; /* data bytes sent */
213: u_long tcps_sndrexmitpack; /* data packets retransmitted */
214: u_long tcps_sndrexmitbyte; /* data bytes retransmitted */
215: u_long tcps_sndacks; /* ack-only packets sent */
216: u_long tcps_sndprobe; /* window probes sent */
217: u_long tcps_sndurg; /* packets sent with URG only */
218: u_long tcps_sndwinup; /* window update-only packets sent */
219: u_long tcps_sndctrl; /* control (SYN|FIN|RST) packets sent */
220:
221: u_long tcps_rcvtotal; /* total packets received */
222: u_long tcps_rcvpack; /* packets received in sequence */
223: u_long tcps_rcvbyte; /* bytes received in sequence */
224: u_long tcps_rcvbadsum; /* packets received with ccksum errs */
225: u_long tcps_rcvbadoff; /* packets received with bad offset */
226: /* u_long tcps_rcvshort; */ /* packets received too short */
227: u_long tcps_rcvduppack; /* duplicate-only packets received */
228: u_long tcps_rcvdupbyte; /* duplicate-only bytes received */
229: u_long tcps_rcvpartduppack; /* packets with some duplicate data */
230: u_long tcps_rcvpartdupbyte; /* dup. bytes in part-dup. packets */
231: u_long tcps_rcvoopack; /* out-of-order packets received */
232: u_long tcps_rcvoobyte; /* out-of-order bytes received */
233: u_long tcps_rcvpackafterwin; /* packets with data after window */
234: u_long tcps_rcvbyteafterwin; /* bytes rcvd after window */
235: u_long tcps_rcvafterclose; /* packets rcvd after "close" */
236: u_long tcps_rcvwinprobe; /* rcvd window probe packets */
237: u_long tcps_rcvdupack; /* rcvd duplicate acks */
238: u_long tcps_rcvacktoomuch; /* rcvd acks for unsent data */
239: u_long tcps_rcvackpack; /* rcvd ack packets */
240: u_long tcps_rcvackbyte; /* bytes acked by rcvd acks */
241: u_long tcps_rcvwinupd; /* rcvd window update packets */
242: /* u_long tcps_pawsdrop; */ /* segments dropped due to PAWS */
243: u_long tcps_predack; /* times hdr predict ok for acks */
244: u_long tcps_preddat; /* times hdr predict ok for data pkts */
245: u_long tcps_socachemiss; /* tcp_last_so misses */
246: u_long tcps_didnuttin; /* Times tcp_output didn't do anything XXX */
247: };
248:
249: extern struct tcpstat tcpstat; /* tcp statistics */
250: extern u_int32_t tcp_now; /* for RFC 1323 timestamps */
251:
252: #endif
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