1SK_CHK_FILTER(9)               Linux Networking               SK_CHK_FILTER(9)
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NAME

6       sk_chk_filter - verify socket filter code
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SYNOPSIS

9       int sk_chk_filter(struct sock_filter * filter, int flen);
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ARGUMENTS

12       filter
13           filter to verify
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15       flen
16           length of filter
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DESCRIPTION

19       Check the user's filter code. If we let some ugly filter code slip
20       through kaboom! The filter must contain no references or jumps that are
21       out of range, no illegal instructions, and must end with a RET
22       instruction.
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24       All jumps are forward as they are not signed.
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26       Returns 0 if the rule set is legal or -EINVAL if not.
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29Kernel Hackers Manual 2.6.       November 2011                SK_CHK_FILTER(9)
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