1IPSEC_GOODMASK(3)          Library Functions Manual          IPSEC_GOODMASK(3)
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NAME

6       ipsec goodmask - is this Internet subnet mask a valid one?
7       ipsec masktobits - convert Internet subnet mask to bit count
8       ipsec bitstomask - convert bit count to Internet subnet mask
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SYNOPSIS

11       #include <freeswan.h>
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13       int goodmask(struct in_addr mask);
14       int masktobits(struct in_addr mask);
15       struct in_addr bitstomask(int n);
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DESCRIPTION

18       These  functions  are  obsolete; see ipsec_masktocount(3) for a partial
19       replacement.
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21       Goodmask reports whether the subnet mask is a valid one, i.e.  consists
22       of  a  (possibly  empty)  sequence of 1s followed by a (possibly empty)
23       sequence of 0s.  Masktobits takes a (valid) subnet mask and returns the
24       number of 1 bits in it.  Bitstomask reverses this, returning the subnet
25       mask corresponding to bit count n.
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27       All masks are in network byte order.
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SEE ALSO

30       inet(3), ipsec_atosubnet(3)
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DIAGNOSTICS

33       Masktobits returns -1 for an invalid mask.  Bitstomask returns an  all-
34       zeros mask for a negative or out-of-range n.
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HISTORY

37       Written for the FreeS/WAN project by Henry Spencer.
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BUGS

40       The  error-reporting  convention of bitstomask is less than ideal; zero
41       is sometimes a legitimate mask.
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45                                 11 June 2001                IPSEC_GOODMASK(3)