ipmask.go

  1package pflag
  2
  3import (
  4	"fmt"
  5	"net"
  6	"strconv"
  7)
  8
  9// -- net.IPMask value
 10type ipMaskValue net.IPMask
 11
 12func newIPMaskValue(val net.IPMask, p *net.IPMask) *ipMaskValue {
 13	*p = val
 14	return (*ipMaskValue)(p)
 15}
 16
 17func (i *ipMaskValue) String() string { return net.IPMask(*i).String() }
 18func (i *ipMaskValue) Set(s string) error {
 19	ip := ParseIPv4Mask(s)
 20	if ip == nil {
 21		return fmt.Errorf("failed to parse IP mask: %q", s)
 22	}
 23	*i = ipMaskValue(ip)
 24	return nil
 25}
 26
 27func (i *ipMaskValue) Type() string {
 28	return "ipMask"
 29}
 30
 31// ParseIPv4Mask written in IP form (e.g. 255.255.255.0).
 32// This function should really belong to the net package.
 33func ParseIPv4Mask(s string) net.IPMask {
 34	mask := net.ParseIP(s)
 35	if mask == nil {
 36		if len(s) != 8 {
 37			return nil
 38		}
 39		// net.IPMask.String() actually outputs things like ffffff00
 40		// so write a horrible parser for that as well  :-(
 41		m := []int{}
 42		for i := 0; i < 4; i++ {
 43			b := "0x" + s[2*i:2*i+2]
 44			d, err := strconv.ParseInt(b, 0, 0)
 45			if err != nil {
 46				return nil
 47			}
 48			m = append(m, int(d))
 49		}
 50		s := fmt.Sprintf("%d.%d.%d.%d", m[0], m[1], m[2], m[3])
 51		mask = net.ParseIP(s)
 52		if mask == nil {
 53			return nil
 54		}
 55	}
 56	return net.IPv4Mask(mask[12], mask[13], mask[14], mask[15])
 57}
 58
 59func parseIPv4Mask(sval string) (interface{}, error) {
 60	mask := ParseIPv4Mask(sval)
 61	if mask == nil {
 62		return nil, fmt.Errorf("unable to parse %s as net.IPMask", sval)
 63	}
 64	return mask, nil
 65}
 66
 67// GetIPv4Mask return the net.IPv4Mask value of a flag with the given name
 68func (f *FlagSet) GetIPv4Mask(name string) (net.IPMask, error) {
 69	val, err := f.getFlagType(name, "ipMask", parseIPv4Mask)
 70	if err != nil {
 71		return nil, err
 72	}
 73	return val.(net.IPMask), nil
 74}
 75
 76// IPMaskVar defines an net.IPMask flag with specified name, default value, and usage string.
 77// The argument p points to an net.IPMask variable in which to store the value of the flag.
 78func (f *FlagSet) IPMaskVar(p *net.IPMask, name string, value net.IPMask, usage string) {
 79	f.VarP(newIPMaskValue(value, p), name, "", usage)
 80}
 81
 82// IPMaskVarP is like IPMaskVar, but accepts a shorthand letter that can be used after a single dash.
 83func (f *FlagSet) IPMaskVarP(p *net.IPMask, name, shorthand string, value net.IPMask, usage string) {
 84	f.VarP(newIPMaskValue(value, p), name, shorthand, usage)
 85}
 86
 87// IPMaskVar defines an net.IPMask flag with specified name, default value, and usage string.
 88// The argument p points to an net.IPMask variable in which to store the value of the flag.
 89func IPMaskVar(p *net.IPMask, name string, value net.IPMask, usage string) {
 90	CommandLine.VarP(newIPMaskValue(value, p), name, "", usage)
 91}
 92
 93// IPMaskVarP is like IPMaskVar, but accepts a shorthand letter that can be used after a single dash.
 94func IPMaskVarP(p *net.IPMask, name, shorthand string, value net.IPMask, usage string) {
 95	CommandLine.VarP(newIPMaskValue(value, p), name, shorthand, usage)
 96}
 97
 98// IPMask defines an net.IPMask flag with specified name, default value, and usage string.
 99// The return value is the address of an net.IPMask variable that stores the value of the flag.
100func (f *FlagSet) IPMask(name string, value net.IPMask, usage string) *net.IPMask {
101	p := new(net.IPMask)
102	f.IPMaskVarP(p, name, "", value, usage)
103	return p
104}
105
106// IPMaskP is like IPMask, but accepts a shorthand letter that can be used after a single dash.
107func (f *FlagSet) IPMaskP(name, shorthand string, value net.IPMask, usage string) *net.IPMask {
108	p := new(net.IPMask)
109	f.IPMaskVarP(p, name, shorthand, value, usage)
110	return p
111}
112
113// IPMask defines an net.IPMask flag with specified name, default value, and usage string.
114// The return value is the address of an net.IPMask variable that stores the value of the flag.
115func IPMask(name string, value net.IPMask, usage string) *net.IPMask {
116	return CommandLine.IPMaskP(name, "", value, usage)
117}
118
119// IPMaskP is like IP, but accepts a shorthand letter that can be used after a single dash.
120func IPMaskP(name, shorthand string, value net.IPMask, usage string) *net.IPMask {
121	return CommandLine.IPMaskP(name, shorthand, value, usage)
122}