NAME

       ipsec_initaddr,  ipsec_addrtypeof, ipsec_addrlenof, ipsec_addrbytesof, ipsec_addrbytesptr - initialize an
       ip_address, get address type of an ip_address, get length of address within an ip_address,  get  copy  of
       address within an ip_address, get pointer to address within an ip_address

SYNOPSIS

       #include <freeswan.h>

       const char *initaddr(const char *src, size_t srclen,
           int af, ip_address *dst);
       int addrtypeof(const ip_address *src);
       size_t addrlenof(const ip_address *src);
       size_t addrbytesof(const ip_address *src,
           unsigned char *dst, size_t dstlen);
       size_t addrbytesptr(const ip_address *src,
           const unsigned char **dst);

DESCRIPTION

       The  <freeswan.h> library uses an internal type ip_address to contain one of the (currently two) types of
       IP address.  These functions provide basic tools for creating and examining this type.

       Initaddr initializes a variable *dst of type ip_address from an address (in network byte order, indicated
       by  a  pointer  src  and  a length srclen) and an address family af (typically AF_INET or AF_INET6).  The
       length must be consistent with the address family.

       Addrtypeof returns the address type of an address,  normally  AF_INET  or  AF_INET6.   (The  <freeswan.h>
       header file arranges to include the necessary headers for these names to be known.)

       Addrlenof  returns  the size (in bytes) of the address within an ip_address, to permit storage allocation
       etc.

       Addrbytesof copies the address within the ip_address src to the buffer indicated by the pointer  dst  and
       the length dstlen, and returns the address length (in bytes).  If the address will not fit, as many bytes
       as will fit are copied; the returned length is still the full length.  It is the caller's  responsibility
       to check the returned value to ensure that there was enough room.

       Addrbytesptr  sets  *dst  to  a  pointer  to  the internal address within the ip_address, and returns the
       address length (in bytes).  If dst is NULL, it just returns the address length.  The  pointer  points  to
       const to discourage misuse.

       Initaddr  returns  NULL  for  success  and  a  pointer to a string-literal error message for failure; see
       DIAGNOSTICS.

       The functions which return size_t return 0 for a failure.

SEE ALSO

       inet(3), ipsec_ttoaddr(3)

DIAGNOSTICS

       An unknown address family is a fatal error for any of these functions except addrtypeof.  An address-size
       mismatch is a fatal error for initaddr.

HISTORY

       Written for the FreeS/WAN project by Henry Spencer.

BUGS

       Addrtypeof should probably have been named addrfamilyof.

                                                  11 Sept 2000                                 IPSEC_INITADDR(3)