cd8b136e12
in_cksum.h required ip.h to be included for struct ip. To be able to use some general checksum functions like in_addword() in a non-IPv4 context, limit the (also exported to user space) IPv4 specific functions to the times, when the ip.h header is present and IPVERSION is defined (to 4). We should consider more general checksum (updating) functions to also allow easier incremental checksum updates in the L3/4 stack and firewalls, as well as ponder further requirements by certain NIC drivers needing slightly different pseudo values in offloading cases. Thinking in terms of a better "library". Sponsored by: The FreeBSD Foundation Sponsored by: iXsystems Reviewed by: gnn (as part of the whole) MFC After: 3 days
69 lines
2.6 KiB
C
69 lines
2.6 KiB
C
/*-
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* Copyright (c) 1990 The Regents of the University of California.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* from tahoe: in_cksum.c 1.2 86/01/05
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* from: @(#)in_cksum.c 1.3 (Berkeley) 1/19/91
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* from: Id: in_cksum.c,v 1.8 1995/12/03 18:35:19 bde Exp
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* $FreeBSD$
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*/
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#ifndef _MACHINE_IN_CKSUM_H_
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#define _MACHINE_IN_CKSUM_H_ 1
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#include <sys/cdefs.h>
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#ifdef _KERNEL
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u_short in_cksum(struct mbuf *m, int len);
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u_short in_addword(u_short sum, u_short b);
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u_short in_cksum_skip(struct mbuf *m, int len, int skip);
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u_int do_cksum(const void *, int);
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#if defined(IPVERSION) && (IPVERSION == 4)
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u_int in_cksum_hdr(const struct ip *);
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#endif
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static __inline u_short
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in_pseudo(u_int sum, u_int b, u_int c)
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{
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__asm __volatile("adds %0, %0, %1\n"
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"adcs %0, %0, %2\n"
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"adc %0, %0, #0\n"
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: "+r" (sum)
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: "r" (b), "r" (c));
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sum = (sum & 0xffff) + (sum >> 16);
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if (sum > 0xffff)
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sum -= 0xffff;
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return (sum);
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}
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#endif /* _KERNEL */
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#endif /* _MACHINE_IN_CKSUM_H_ */
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