xref: /original-bsd/sys/netinet/tcp_var.h (revision 6cca134b)
1 /*
2  * Copyright (c) 1982, 1986 Regents of the University of California.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms are permitted
6  * provided that the above copyright notice and this paragraph are
7  * duplicated in all such forms and that any documentation,
8  * advertising materials, and other materials related to such
9  * distribution and use acknowledge that the software was developed
10  * by the University of California, Berkeley.  The name of the
11  * University may not be used to endorse or promote products derived
12  * from this software without specific prior written permission.
13  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
14  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
15  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
16  *
17  *	@(#)tcp_var.h	7.8 (Berkeley) 06/29/88
18  */
19 
20 /*
21  * TCP configuration:  This is a half-assed attempt to make TCP
22  * self-configure for a few varieties of 4.2 and 4.3-based unixes.
23  * If you don't have a) a 4.3bsd vax or b) a 3.x Sun (x<6), check
24  * this carefully (it's probably not right).  Please send me mail
25  * if you run into configuration problems.
26  *  - Van Jacobson (van@lbl-csam.arpa)
27  */
28 
29 #ifndef BSD
30 #define BSD 42	/* if we're not 4.3, pretend we're 4.2 */
31 #define OLDSTAT	/* set if we have to use old netstat binaries */
32 #endif
33 
34 /* #define OLDSTAT	/* set if we have to use old netstat binaries */
35 
36 #if sun || BSD < 43
37 #define TCP_COMPAT_42	/* set if we have to interop w/4.2 systems */
38 #endif
39 
40 #ifndef SB_MAX
41 #ifdef	SB_MAXCOUNT
42 #define	SB_MAX	SB_MAXCOUNT	/* Sun has to be a little bit different... */
43 #else
44 #define SB_MAX	32767		/* XXX */
45 #endif	SB_MAXCOUNT
46 #endif	SB_MAX
47 
48 #ifndef IP_MAXPACKET
49 #define	IP_MAXPACKET	65535		/* maximum packet size */
50 #endif
51 
52 /*
53  * Bill Nowicki pointed out that the page size (CLBYTES) has
54  * nothing to do with the mbuf cluster size.  So, we followed
55  * Sun's lead and made the new define MCLBYTES stand for the mbuf
56  * cluster size.  The following define makes up backwards compatible
57  * with 4.3 and 4.2.  If CLBYTES is >1024 on your machine, check
58  * this against the mbuf cluster definitions in /usr/include/sys/mbuf.h.
59  */
60 #ifndef MCLBYTES
61 #define	MCLBYTES CLBYTES	/* XXX */
62 #endif
63 
64 /*
65  * The routine in_localaddr is broken in Sun's 3.4.  We redefine ours
66  * (in tcp_input.c) so we use can it but won't have a name conflict.
67  */
68 #ifdef sun
69 #define in_localaddr tcp_in_localaddr
70 #endif
71 
72 /* --------------- end of TCP config ---------------- */
73 
74 /*
75  * Kernel variables for tcp.
76  */
77 
78 /*
79  * Tcp control block, one per tcp; fields:
80  */
81 struct tcpcb {
82 	struct	tcpiphdr *seg_next;	/* sequencing queue */
83 	struct	tcpiphdr *seg_prev;
84 	short	t_state;		/* state of this connection */
85 	short	t_timer[TCPT_NTIMERS];	/* tcp timers */
86 	short	t_rxtshift;		/* log(2) of rexmt exp. backoff */
87 	short	t_rxtcur;		/* current retransmit value */
88 	short	t_dupacks;		/* consecutive dup acks recd */
89 	u_short	t_maxseg;		/* maximum segment size */
90 	char	t_force;		/* 1 if forcing out a byte */
91 	u_char	t_flags;
92 #define	TF_ACKNOW	0x01		/* ack peer immediately */
93 #define	TF_DELACK	0x02		/* ack, but try to delay it */
94 #define	TF_NODELAY	0x04		/* don't delay packets to coalesce */
95 #define	TF_NOOPT	0x08		/* don't use tcp options */
96 #define	TF_SENTFIN	0x10		/* have sent FIN */
97 	struct	tcpiphdr *t_template;	/* skeletal packet for transmit */
98 	struct	inpcb *t_inpcb;		/* back pointer to internet pcb */
99 /*
100  * The following fields are used as in the protocol specification.
101  * See RFC783, Dec. 1981, page 21.
102  */
103 /* send sequence variables */
104 	tcp_seq	snd_una;		/* send unacknowledged */
105 	tcp_seq	snd_nxt;		/* send next */
106 	tcp_seq	snd_up;			/* send urgent pointer */
107 	tcp_seq	snd_wl1;		/* window update seg seq number */
108 	tcp_seq	snd_wl2;		/* window update seg ack number */
109 	tcp_seq	iss;			/* initial send sequence number */
110 	u_short	snd_wnd;		/* send window */
111 /* receive sequence variables */
112 	u_short	rcv_wnd;		/* receive window */
113 	tcp_seq	rcv_nxt;		/* receive next */
114 	tcp_seq	rcv_up;			/* receive urgent pointer */
115 	tcp_seq	irs;			/* initial receive sequence number */
116 /*
117  * Additional variables for this implementation.
118  */
119 /* receive variables */
120 	tcp_seq	rcv_adv;		/* advertised window */
121 /* retransmit variables */
122 	tcp_seq	snd_max;		/* highest sequence number sent
123 					 * used to recognize retransmits
124 					 */
125 /* congestion control (for slow start, source quench, retransmit after loss) */
126 	u_short	snd_cwnd;		/* congestion-controlled window */
127 	u_short snd_ssthresh;		/* snd_cwnd size threshhold for
128 					 * for slow start exponential to
129 					 * linear switch */
130 /*
131  * transmit timing stuff.
132  * srtt and rttvar are stored as fixed point; for convenience in smoothing,
133  * srtt has 3 bits to the right of the binary point, rttvar has 2.
134  * "Variance" is actually smoothed difference.
135  */
136 	short	t_idle;			/* inactivity time */
137 	short	t_rtt;			/* round trip time */
138 	tcp_seq	t_rtseq;		/* sequence number being timed */
139 	short	t_srtt;			/* smoothed round-trip time */
140 	short	t_rttvar;		/* variance in round-trip time */
141 	u_short max_rcvd;		/* most peer has sent into window */
142 	u_short	max_sndwnd;		/* largest window peer has offered */
143 /* out-of-band data */
144 	char	t_oobflags;		/* have some */
145 	char	t_iobc;			/* input character */
146 #define	TCPOOB_HAVEDATA	0x01
147 #define	TCPOOB_HADDATA	0x02
148 };
149 
150 #define	intotcpcb(ip)	((struct tcpcb *)(ip)->inp_ppcb)
151 #define	sototcpcb(so)	(intotcpcb(sotoinpcb(so)))
152 
153 /*
154  * TCP statistics.
155  * Many of these should be kept per connection,
156  * but that's inconvenient at the moment.
157  */
158 struct	tcpstat {
159 #ifdef OLDSTAT
160 	/*
161 	 * Declare statistics the same as in 4.3
162 	 * at the start of tcpstat (same size and
163 	 * position) for netstat.
164 	 */
165 	int	tcps_rcvbadsum;
166 	int	tcps_rcvbadoff;
167 	int	tcps_rcvshort;
168 	int	tcps_badsegs;
169 	int	tcps_unack;
170 #define	tcps_badsum	tcps_rcvbadsum
171 #define	tcps_badoff	tcps_rcvbadoff
172 #define	tcps_hdrops	tcps_rcvshort
173 
174 #endif OLDSTAT
175 	u_long	tcps_connattempt;	/* connections initiated */
176 	u_long	tcps_accepts;		/* connections accepted */
177 	u_long	tcps_connects;		/* connections established */
178 	u_long	tcps_drops;		/* connections dropped */
179 	u_long	tcps_conndrops;		/* embryonic connections dropped */
180 	u_long	tcps_closed;		/* conn. closed (includes drops) */
181 	u_long	tcps_segstimed;		/* segs where we tried to get rtt */
182 	u_long	tcps_rttupdated;	/* times we succeeded */
183 	u_long	tcps_delack;		/* delayed acks sent */
184 	u_long	tcps_timeoutdrop;	/* conn. dropped in rxmt timeout */
185 	u_long	tcps_rexmttimeo;	/* retransmit timeouts */
186 	u_long	tcps_persisttimeo;	/* persist timeouts */
187 	u_long	tcps_keeptimeo;		/* keepalive timeouts */
188 	u_long	tcps_keepprobe;		/* keepalive probes sent */
189 	u_long	tcps_keepdrops;		/* connections dropped in keepalive */
190 
191 	u_long	tcps_sndtotal;		/* total packets sent */
192 	u_long	tcps_sndpack;		/* data packets sent */
193 	u_long	tcps_sndbyte;		/* data bytes sent */
194 	u_long	tcps_sndrexmitpack;	/* data packets retransmitted */
195 	u_long	tcps_sndrexmitbyte;	/* data bytes retransmitted */
196 	u_long	tcps_sndacks;		/* ack-only packets sent */
197 	u_long	tcps_sndprobe;		/* window probes sent */
198 	u_long	tcps_sndurg;		/* packets sent with URG only */
199 	u_long	tcps_sndwinup;		/* window update-only packets sent */
200 	u_long	tcps_sndctrl;		/* control (SYN|FIN|RST) packets sent */
201 
202 	u_long	tcps_rcvtotal;		/* total packets received */
203 	u_long	tcps_rcvpack;		/* packets received in sequence */
204 	u_long	tcps_rcvbyte;		/* bytes received in sequence */
205 #ifndef OLDSTAT
206 	u_long	tcps_rcvbadsum;		/* packets received with ccksum errs */
207 	u_long	tcps_rcvbadoff;		/* packets received with bad offset */
208 	u_long	tcps_rcvshort;		/* packets received too short */
209 #endif
210 	u_long	tcps_rcvduppack;	/* duplicate-only packets received */
211 	u_long	tcps_rcvdupbyte;	/* duplicate-only bytes received */
212 	u_long	tcps_rcvpartduppack;	/* packets with some duplicate data */
213 	u_long	tcps_rcvpartdupbyte;	/* dup. bytes in part-dup. packets */
214 	u_long	tcps_rcvoopack;		/* out-of-order packets received */
215 	u_long	tcps_rcvoobyte;		/* out-of-order bytes received */
216 	u_long	tcps_rcvpackafterwin;	/* packets with data after window */
217 	u_long	tcps_rcvbyteafterwin;	/* bytes rcvd after window */
218 	u_long	tcps_rcvafterclose;	/* packets rcvd after "close" */
219 	u_long	tcps_rcvwinprobe;	/* rcvd window probe packets */
220 	u_long	tcps_rcvdupack;		/* rcvd duplicate acks */
221 	u_long	tcps_rcvacktoomuch;	/* rcvd acks for unsent data */
222 	u_long	tcps_rcvackpack;	/* rcvd ack packets */
223 	u_long	tcps_rcvackbyte;	/* bytes acked by rcvd acks */
224 	u_long	tcps_rcvwinupd;		/* rcvd window update packets */
225 };
226 
227 #ifdef KERNEL
228 struct	inpcb tcb;		/* head of queue of active tcpcb's */
229 struct	tcpstat tcpstat;	/* tcp statistics */
230 struct	tcpiphdr *tcp_template();
231 struct	tcpcb *tcp_close(), *tcp_drop();
232 struct	tcpcb *tcp_timers(), *tcp_disconnect(), *tcp_usrclosed();
233 #endif
234