trusty (3) ipsec_bitstomask.3.gz

Provided by: openswan_2.6.38-1_amd64 bug

NAME
       ipsec_goodmask,  ipsec_masktobits,  ipsec_bitstomask  -  check  if Internet subnet mask is valid, convert
       Internet subnet mask to bit count, convert bit count to Internet subnet mask


SYNOPSIS
       #include <freeswan.h>

       int goodmask(struct in_addr mask);
       int masktobits(struct in_addr mask);
       struct in_addr bitstomask(int n);


DESCRIPTION
       These functions are obsolete; see ipsec_masktocount(3) for a partial replacement.

       Goodmask reports whether the subnet mask is a valid one, i.e. consists of a (possibly empty) sequence  of
       1s followed by a (possibly empty) sequence of 0s.  Masktobits takes a (valid) subnet mask and returns the
       number of 1 bits in it.  Bitstomask reverses this, returning the subnet mask corresponding to  bit  count
       n.

       All masks are in network byte order.


SEE ALSO
       inet(3), ipsec_atosubnet(3)


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


HISTORY
       Written for the FreeS/WAN project by Henry Spencer.


BUGS
       The error-reporting convention of bitstomask is less than ideal; zero is sometimes a legitimate mask.

                                                  11 June 2001                                 IPSEC_GOODMASK(3)