package pflag import ( "fmt" "net" "strconv" ) // -- net.IPMask value type ipMaskValue net.IPMask func newIPMaskValue(val net.IPMask, p *net.IPMask) *ipMaskValue { *p = val return (*ipMaskValue)(p) } func (i *ipMaskValue) String() string { return net.IPMask(*i).String() } func (i *ipMaskValue) Set(s string) error { ip := ParseIPv4Mask(s) if ip == nil { return fmt.Errorf("failed to parse IP mask: %q", s) } *i = ipMaskValue(ip) return nil } func (i *ipMaskValue) Type() string { return "ipMask" } // Parse IPv4 netmask written in IP form (e.g. 255.255.255.0). // This function should really belong to the net package. func ParseIPv4Mask(s string) net.IPMask { mask := net.ParseIP(s) if mask == nil { if len(s) != 8 { return nil } // net.IPMask.String() actually outputs things like ffffff00 // so write a horrible parser for that as well :-( m := []int{} for i := 0; i < 4; i++ { b := "0x" + s[2*i:2*i+2] d, err := strconv.ParseInt(b, 0, 0) if err != nil { return nil } m = append(m, int(d)) } s := fmt.Sprintf("%d.%d.%d.%d", m[0], m[1], m[2], m[3]) mask = net.ParseIP(s) if mask == nil { return nil } } return net.IPv4Mask(mask[12], mask[13], mask[14], mask[15]) } func parseIPv4Mask(sval string) (interface{}, error) { mask := ParseIPv4Mask(sval) if mask == nil { return nil, fmt.Errorf("unable to parse %s as net.IPMask", sval) } return mask, nil } // GetIPv4Mask return the net.IPv4Mask value of a flag with the given name func (f *FlagSet) GetIPv4Mask(name string) (net.IPMask, error) { val, err := f.getFlagType(name, "ipMask", parseIPv4Mask) if err != nil { return nil, err } return val.(net.IPMask), nil } // IPMaskVar defines an net.IPMask flag with specified name, default value, and usage string. // The argument p points to an net.IPMask variable in which to store the value of the flag. func (f *FlagSet) IPMaskVar(p *net.IPMask, name string, value net.IPMask, usage string) { f.VarP(newIPMaskValue(value, p), name, "", usage) } // Like IPMaskVar, but accepts a shorthand letter that can be used after a single dash. func (f *FlagSet) IPMaskVarP(p *net.IPMask, name, shorthand string, value net.IPMask, usage string) { f.VarP(newIPMaskValue(value, p), name, shorthand, usage) } // IPMaskVar defines an net.IPMask flag with specified name, default value, and usage string. // The argument p points to an net.IPMask variable in which to store the value of the flag. func IPMaskVar(p *net.IPMask, name string, value net.IPMask, usage string) { CommandLine.VarP(newIPMaskValue(value, p), name, "", usage) } // Like IPMaskVar, but accepts a shorthand letter that can be used after a single dash. func IPMaskVarP(p *net.IPMask, name, shorthand string, value net.IPMask, usage string) { CommandLine.VarP(newIPMaskValue(value, p), name, shorthand, usage) } // IPMask defines an net.IPMask flag with specified name, default value, and usage string. // The return value is the address of an net.IPMask variable that stores the value of the flag. func (f *FlagSet) IPMask(name string, value net.IPMask, usage string) *net.IPMask { p := new(net.IPMask) f.IPMaskVarP(p, name, "", value, usage) return p } // Like IPMask, but accepts a shorthand letter that can be used after a single dash. func (f *FlagSet) IPMaskP(name, shorthand string, value net.IPMask, usage string) *net.IPMask { p := new(net.IPMask) f.IPMaskVarP(p, name, shorthand, value, usage) return p } // IPMask defines an net.IPMask flag with specified name, default value, and usage string. // The return value is the address of an net.IPMask variable that stores the value of the flag. func IPMask(name string, value net.IPMask, usage string) *net.IPMask { return CommandLine.IPMaskP(name, "", value, usage) } // Like IP, but accepts a shorthand letter that can be used after a single dash. func IPMaskP(name, shorthand string, value net.IPMask, usage string) *net.IPMask { return CommandLine.IPMaskP(name, shorthand, value, usage) }