60 lines
1.2 KiB
Groff
60 lines
1.2 KiB
Groff
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ONE_CSUM(3) Minix Programmer's Manual ONE_CSUM(3)
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NAME
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oneC_sum - One's complement internet checksum
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SYNOPSIS
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#define _MINIX_SOURCE 1
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#include <stddef.h>
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#include <sys/types.h>
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#include <net/gen/oneCsum.h>
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u16_t oneC_sum(u16_t prev, u16_t *data, size_t size)
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DESCRIPTION
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OneC_sum is used to calculate the one's complement checksum needed for IP
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network packets. A good document about the Internet Checksum is RFC-1071
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(Computing the Internet checksum).
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One_Csum expects three parameters:
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prev The checksum of previous blocks of data that are to be included
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in the checksum. The value of prev in first call to oneC_sum
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should be 0.
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data A pointer to the block of data. The data is interpreted as a
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series of 16 bit numbers in network byte order, but an odd
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number of bytes is also allowed.
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size The size of the data in bytes.
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SEE ALSO
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ip(4).
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RFC-1071
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AUTHOR
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Philip Homburg (philip@cs.vu.nl)
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1
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