Provided by: openswan_2.6.37-1_amd64
ipsec_initsubnet, ipsec_addrtosubnet, ipsec_subnettypeof, ipsec_masktocount, ipsec_networkof, ipsec_maskof - initialize an ip_subnet, initialize a singleton ip_subnet, get address type of an ip_subnet, convert subnet mask to bit count, get base address of an ip_subnet, get subnet mask of an ip_subnet
#include <freeswan.h> const char *initsubnet(const ip_address *addr, int maskbits, int clash, ip_subnet *dst); const char *addrtosubnet(const ip_address *addr, ip_subnet *dst); int subnettypeof(const ip_subnet *src); int masktocount(const ip_address *src); void networkof(const ip_subnet *src, ip_address *dst); void maskof(const ip_subnet *src, ip_address *dst);
The <freeswan.h> library uses an internal type ip_subnet to contain a description of an IP subnet (base address plus mask). These functions provide basic tools for creating and examining this type. Initsubnet initializes a variable *dst of type ip_subnet from a base address and a count of mask bits. The clash parameter specifies what to do if the base address includes 1 bits outside the prefix specified by the mask (that is, in the ``host number'' part of the address): '0' zero out host-number bits 'x' non-zero host-number bits are an error Initsubnet returns NULL for success and a pointer to a string-literal error message for failure; see DIAGNOSTICS. Addrtosubnet initializes an ip_subnet variable *dst to a ``singleton subnet'' containing the single address *addr. It returns NULL for success and a pointer to a string-literal error message for failure. Subnettypeof returns the address type of a subnet, normally AF_INET or AF_INET6. (The <freeswan.h> header file arranges to include the necessary headers for these names to be known.) Masktocount converts a subnet mask, expressed as an address, to a bit count suitable for use with initsubnet. It returns -1 for error; see DIAGNOSTICS. Networkof fills in *dst with the base address of subnet src. Maskof fills in *dst with the subnet mask of subnet src, expressed as an address.
inet(3), ipsec_ttosubnet(3), ipsec_rangetosubnet(3)
Fatal errors in initsubnet are: unknown address family; unknown clash value; impossible mask bit count; non-zero host-number bits and clash is 'x'. Fatal errors in addrtosubnet are: unknown address family. Fatal errors in masktocount are: unknown address family; mask bits not contiguous.
Written for the FreeS/WAN project by Henry Spencer. 12 March 2002 IPSEC_INITSUBNET(3)