xref: /csrg-svn/sys/netinet/tcp_seq.h (revision 25203)
123192Smckusick /*
223192Smckusick  * Copyright (c) 1982 Regents of the University of California.
323192Smckusick  * All rights reserved.  The Berkeley software License Agreement
423192Smckusick  * specifies the terms and conditions for redistribution.
523192Smckusick  *
6*25203Skarels  *	@(#)tcp_seq.h	6.3 (Berkeley) 10/15/85
723192Smckusick  */
85124Swnj 
95124Swnj /*
105124Swnj  * TCP sequence numbers are 32 bit integers operated
115124Swnj  * on with modular arithmetic.  These macros can be
125124Swnj  * used to compare such integers.
135124Swnj  */
145124Swnj #define	SEQ_LT(a,b)	((int)((a)-(b)) < 0)
155124Swnj #define	SEQ_LEQ(a,b)	((int)((a)-(b)) <= 0)
165124Swnj #define	SEQ_GT(a,b)	((int)((a)-(b)) > 0)
175124Swnj #define	SEQ_GEQ(a,b)	((int)((a)-(b)) >= 0)
185124Swnj 
195124Swnj /*
205124Swnj  * Macros to initialize tcp sequence numbers for
215124Swnj  * send and receive from initial send and receive
225124Swnj  * sequence numbers.
235124Swnj  */
245124Swnj #define	tcp_rcvseqinit(tp) \
25*25203Skarels 	(tp)->rcv_adv = (tp)->rcv_nxt = (tp)->irs + 1
265124Swnj 
275124Swnj #define	tcp_sendseqinit(tp) \
285124Swnj 	(tp)->snd_una = (tp)->snd_nxt = (tp)->snd_max = (tp)->snd_up = \
295124Swnj 	    (tp)->iss
305124Swnj 
31*25203Skarels #define	TCP_ISSINCR	128	/* increment for tcp_iss each second */
325124Swnj 
335124Swnj #ifdef KERNEL
345124Swnj tcp_seq	tcp_iss;		/* tcp initial send seq # */
355124Swnj #endif
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