freebsd-skq/sys/netinet/tcp_seq.h
Paul Saab cf09195ba5 - Tighten up the Timestamp checks to prevent a spoofed segment from
setting ts_recent to an arbitrary value, stopping further
  communication between the two hosts.
- If the Echoed Timestamp is greater than the current time,
  fall back to the non RFC 1323 RTT calculation.

Submitted by:	Raja Mukerji (raja at moselle dot com)
Reviewed by:	Noritoshi Demizu, Mohan Srinivasan
2005-04-10 05:24:59 +00:00

82 lines
3.1 KiB
C

/*-
* Copyright (c) 1982, 1986, 1993, 1995
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)tcp_seq.h 8.3 (Berkeley) 6/21/95
* $FreeBSD$
*/
#ifndef _NETINET_TCP_SEQ_H_
#define _NETINET_TCP_SEQ_H_
/*
* TCP sequence numbers are 32 bit integers operated
* on with modular arithmetic. These macros can be
* used to compare such integers.
*/
#define SEQ_LT(a,b) ((int)((a)-(b)) < 0)
#define SEQ_LEQ(a,b) ((int)((a)-(b)) <= 0)
#define SEQ_GT(a,b) ((int)((a)-(b)) > 0)
#define SEQ_GEQ(a,b) ((int)((a)-(b)) >= 0)
#define SEQ_MIN(a, b) ((SEQ_LT(a, b)) ? (a) : (b))
#define SEQ_MAX(a, b) ((SEQ_GT(a, b)) ? (a) : (b))
/* for modulo comparisons of timestamps */
#define TSTMP_LT(a,b) ((int)((a)-(b)) < 0)
#define TSTMP_GT(a,b) ((int)((a)-(b)) > 0)
#define TSTMP_GEQ(a,b) ((int)((a)-(b)) >= 0)
/*
* TCP connection counts are 32 bit integers operated
* on with modular arithmetic. These macros can be
* used to compare such integers.
*/
#define CC_LT(a,b) ((int)((a)-(b)) < 0)
#define CC_LEQ(a,b) ((int)((a)-(b)) <= 0)
#define CC_GT(a,b) ((int)((a)-(b)) > 0)
#define CC_GEQ(a,b) ((int)((a)-(b)) >= 0)
/* Macro to increment a CC: skip 0 which has a special meaning */
#define CC_INC(c) (++(c) == 0 ? ++(c) : (c))
/*
* Macros to initialize tcp sequence numbers for
* send and receive from initial send and receive
* sequence numbers.
*/
#define tcp_rcvseqinit(tp) \
(tp)->rcv_adv = (tp)->rcv_nxt = (tp)->irs + 1
#define tcp_sendseqinit(tp) \
(tp)->snd_una = (tp)->snd_nxt = (tp)->snd_max = (tp)->snd_up = \
(tp)->snd_recover = (tp)->iss
#define TCP_PAWS_IDLE (24 * 24 * 60 * 60 * hz)
/* timestamp wrap-around time */
#endif /* _NETINET_TCP_SEQ_H_ */