trusty (3) ipsec_rangetoa.3.gz

NAME

       ipsec_atoasr,  ipsec_rangetoa  -  convert  ASCII  to Internet address, subnet, or range, convert Internet
       address range to ASCII

SYNOPSIS

       #include <freeswan.h>

       const char *atoasr(const char *src, size_t srclen,
           char *type, struct in_addr *addrs);
       size_t rangetoa(struct in_addr *addrs, int format,
           char *dst, size_t dstlen);

DESCRIPTION

       These functions are obsolete; there is no current equivalent, because so far they have not proved useful.

       Atoasr converts an ASCII address, subnet,  or  address  range  into  a  suitable  combination  of  binary
       addresses  (in  network  byte  order).  Rangetoa converts an address range back into ASCII, using dotted-
       decimal form for the addresses (the  other  reverse  conversions  are  handled  by  ipsec_addrtoa(3)  and
       ipsec_subnettoa(3)).

       A single address can be any form acceptable to ipsec_atoaddr(3): dotted decimal, DNS name, or hexadecimal
       number.  A subnet specification uses the form network/mask interpreted by ipsec_atosubnet(3).

       An address range is two ipsec_atoaddr(3) addresses separated by a ...  delimiter.  If there are four dots
       rather  than  three,  the first is taken as part of the begin address, e.g. for a complete DNS name which
       ends with .  to suppress completion attempts.  The begin address of a range must be less than or equal to
       the end address.

       The srclen parameter of atoasr specifies the length of the ASCII string pointed to by src; it is an error
       for there to be anything else (e.g., a terminating NUL) within that length.  As a convenience  for  cases
       where  an  entire  NUL-terminated  string  is  to  be  converted,  a  srclen  value of 0 is taken to mean
       strlen(src).

       The type parameter of atoasr must point to a char variable used to record  which  form  was  found.   The
       addrs  parameter  must  point  to  a two-element array of struct in_addr which receives the results.  The
       values stored into *type, and the corresponding values in the array, are:

                   *type   addrs[0]    addrs[1]

       address     'a'     address     -
       subnet      's'     network     mask
       range       'r'     begin       end

       The dstlen parameter of rangetoa specifies the size of the dst parameter; under no circumstances are more
       than  dstlen  bytes  written  to  dst.  A result which will not fit is truncated.  Dstlen can be zero, in
       which case dst need not be valid and no result is written, but the return value  is  unaffected;  in  all
       other  cases,  the  (possibly  truncated) result is NUL-terminated.  The freeswan.h header file defines a
       constant, RANGETOA_BUF, which is the size of a buffer just large enough for worst-case results.

       The format parameter of rangetoa specifies what format is to be used for the  conversion.   The  value  0
       (not  the  ASCII character '0', but a zero value) specifies a reasonable default, and is in fact the only
       format currently available.  This parameter is a hedge against future needs.

       Atoasr returns NULL for success and a  pointer  to  a  string-literal  error  message  for  failure;  see
       DIAGNOSTICS.   Rangetoa  returns  0  for a failure, and otherwise always returns the size of buffer which
       would be needed to accommodate the full conversion result, including terminating NUL; it is the  caller's
       responsibility  to check this against the size of the provided buffer to determine whether truncation has
       occurred.

SEE ALSO

       ipsec_atoaddr(3), ipsec_atosubnet(3)

DIAGNOSTICS

       Fatal errors in  atoasr  are:  empty  input;  error  in  ipsec_atoaddr(3)  or  ipsec_atosubnet(3)  during
       conversion; begin address of range exceeds end address.

       Fatal errors in rangetoa are: unknown format.

HISTORY

       Written for the FreeS/WAN project by Henry Spencer.

BUGS

       The  restriction  of  error reports to literal strings (so that callers don't need to worry about freeing
       them or copying them) does limit the precision of error reporting.

       The error-reporting convention lends itself to slightly obscure code, because many readers will not think
       of NULL as signifying success.  A good way to make it clearer is to write something like:

              const char *error;

              error = atoasr( /* ... */ );
              if (error != NULL) {
                      /* something went wrong */

                                                  11 June 2001                                   IPSEC_ATOASR(3)