// An IP is a single IP address, an array of bytes.
// Functions in this package accept either 4-byte (IPv4)
-// or 16-byte (IPv6) arrays as input. Unless otherwise
-// specified, functions in this package always return
-// IP addresses in 16-byte form using the canonical
-// embedding.
+// or 16-byte (IPv6) arrays as input.
//
// Note that in this documentation, referring to an
// IP address as an IPv4 address or an IPv6 address
// An IP mask is an IP address.
type IPMask []byte
+// An IPNet represents an IP network.
+type IPNet struct {
+ IP IP // network number
+ Mask IPMask // network mask
+}
+
// IPv4 returns the IP address (in 16-byte form) of the
// IPv4 address a.b.c.d.
func IPv4(a, b, c, d byte) IP {
return p
}
+// CIDRMask returns an IPMask of size bits with the first n bits
+// set to to 1. nil is returned if the mask is impossible.
+func CIDRMask(ones, bits int) IPMask {
+ if bits != 8*IPv4len && bits != 8*IPv6len {
+ return nil
+ }
+ if ones < 0 || ones > bits {
+ return nil
+ }
+ l := bits / 8
+ m := make(IPMask, l)
+ n := uint(ones)
+ for i := 0; i < l; i++ {
+ if n >= 8 {
+ m[i] = 0xff
+ n -= 8
+ continue
+ }
+ m[i] = ^byte(0xff >> n)
+ n = 0
+ }
+ return m
+}
+
// Well-known IPv4 addresses
var (
IPv4bcast = IPv4(255, 255, 255, 255) // broadcast
return s
}
+func networkNumberAndMask(n *IPNet) (ip IP, m IPMask) {
+ if ip = n.IP.To4(); ip == nil {
+ ip = n.IP
+ if len(ip) != IPv6len {
+ return nil, nil
+ }
+ }
+ m = n.Mask
+ switch len(m) {
+ case IPv4len:
+ if len(ip) != IPv4len {
+ return nil, nil
+ }
+ case IPv6len:
+ if len(ip) == IPv4len {
+ m = m[12:]
+ }
+ default:
+ return nil, nil
+ }
+ return
+}
+
+// Contains reports whether the network includes ip.
+func (n *IPNet) Contains(ip IP) bool {
+ nn, m := networkNumberAndMask(n)
+ if x := ip.To4(); x != nil {
+ ip = x
+ }
+ l := len(ip)
+ if l != len(nn) {
+ return false
+ }
+ for i := 0; i < l; i++ {
+ if nn[i]&m[i] != ip[i]&m[i] {
+ return false
+ }
+ }
+ return true
+}
+
+// String returns the CIDR notation of n like "192.168.100.1/24"
+// or "2001:DB8::/48" as defined in RFC 4632 and RFC 4291.
+// If the mask is not in the canonical form, it returns the
+// string which consists of an IP address, followed by a slash
+// character and a mask expressed as hexadecimal form with no
+// punctuation like "192.168.100.1/c000ff00".
+func (n *IPNet) String() string {
+ nn, m := networkNumberAndMask(n)
+ if nn == nil || m == nil {
+ return "<nil>"
+ }
+ l := simpleMaskLength(m)
+ if l == -1 {
+ return nn.String() + "/" + m.String()
+ }
+ return nn.String() + "/" + itod(uint(l))
+}
+
// Parse IPv4 address (d.d.d.d).
func parseIPv4(s string) IP {
var p [IPv4len]byte
// ParseCIDR parses s as a CIDR notation IP address and mask,
// like "192.168.100.1/24" or "2001:DB8::/48", as defined in
// RFC 4632 and RFC 4291.
-func ParseCIDR(s string) (ip IP, mask IPMask, err os.Error) {
+//
+// It returns the IP address and the network implied by the IP
+// and mask. For example, ParseCIDR("192.168.100.1/16") returns
+// the IP address 192.168.100.1 and the network 192.168.0.0/16.
+func ParseCIDR(s string) (IP, *IPNet, os.Error) {
i := byteIndex(s, '/')
if i < 0 {
return nil, nil, &ParseError{"CIDR address", s}
}
ipstr, maskstr := s[:i], s[i+1:]
iplen := IPv4len
- ip = parseIPv4(ipstr)
+ ip := parseIPv4(ipstr)
if ip == nil {
iplen = IPv6len
ip = parseIPv6(ipstr)
}
- nn, i, ok := dtoi(maskstr, 0)
- if ip == nil || !ok || i != len(maskstr) || nn < 0 || nn > 8*iplen {
+ n, i, ok := dtoi(maskstr, 0)
+ if ip == nil || !ok || i != len(maskstr) || n < 0 || n > 8*iplen {
return nil, nil, &ParseError{"CIDR address", s}
}
- n := uint(nn)
- if iplen == IPv4len {
- v4mask := ^uint32(0xffffffff >> n)
- mask = IPv4Mask(byte(v4mask>>24), byte(v4mask>>16), byte(v4mask>>8), byte(v4mask))
- } else {
- mask = make(IPMask, IPv6len)
- for i := 0; i < IPv6len; i++ {
- if n >= 8 {
- mask[i] = 0xff
- n -= 8
- continue
- }
- mask[i] = ^byte(0xff >> n)
- n = 0
-
- }
- }
- // address must not have any bits not in mask
- mip := ip
- if iplen == IPv4len {
- mip = ip[12:]
- }
- for i := range mip {
- if mip[i]&^mask[i] != 0 {
- return nil, nil, &ParseError{"CIDR address", s}
- }
- }
- return ip, mask, nil
+ m := CIDRMask(n, 8*iplen)
+ return ip, &IPNet{ip.Mask(m), m}, nil
}
{"::ffff:127.0.0.1", IPv4(127, 0, 0, 1)},
{"2001:4860:0:2001::68", IP{0x20, 0x01, 0x48, 0x60, 0, 0, 0x20, 0x01, 0, 0, 0, 0, 0, 0, 0x00, 0x68}},
{"::ffff:4a7d:1363", IPv4(74, 125, 19, 99)},
+ {"", nil},
}
func TestParseIP(t *testing.T) {
for _, tt := range parseiptests {
if out := ParseIP(tt.in); !isEqual(out, tt.out) {
- t.Errorf("ParseIP(%#q) = %v, want %v", tt.in, out, tt.out)
+ t.Errorf("ParseIP(%q) = %v, want %v", tt.in, out, tt.out)
}
}
}
func TestIPString(t *testing.T) {
for _, tt := range ipstringtests {
if out := tt.in.String(); out != tt.out {
- t.Errorf("IP.String(%v) = %#q, want %#q", tt.in, out, tt.out)
+ t.Errorf("IP.String(%v) = %q, want %q", tt.in, out, tt.out)
}
}
}
}
var parsecidrtests = []struct {
- in string
- ip IP
- mask IPMask
- err os.Error
+ in string
+ ip IP
+ net *IPNet
+ err os.Error
}{
- {"135.104.0.0/32", IPv4(135, 104, 0, 0), IPv4Mask(255, 255, 255, 255), nil},
- {"0.0.0.0/24", IPv4(0, 0, 0, 0), IPv4Mask(255, 255, 255, 0), nil},
- {"135.104.0.0/24", IPv4(135, 104, 0, 0), IPv4Mask(255, 255, 255, 0), nil},
- {"135.104.0.1/32", IPv4(135, 104, 0, 1), IPv4Mask(255, 255, 255, 255), nil},
- {"135.104.0.1/24", nil, nil, &ParseError{"CIDR address", "135.104.0.1/24"}},
- {"::1/128", ParseIP("::1"), IPMask(ParseIP("ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff")), nil},
- {"abcd:2345::/127", ParseIP("abcd:2345::"), IPMask(ParseIP("ffff:ffff:ffff:ffff:ffff:ffff:ffff:fffe")), nil},
- {"abcd:2345::/65", ParseIP("abcd:2345::"), IPMask(ParseIP("ffff:ffff:ffff:ffff:8000::")), nil},
- {"abcd:2345::/64", ParseIP("abcd:2345::"), IPMask(ParseIP("ffff:ffff:ffff:ffff::")), nil},
- {"abcd:2345::/63", ParseIP("abcd:2345::"), IPMask(ParseIP("ffff:ffff:ffff:fffe::")), nil},
- {"abcd:2345::/33", ParseIP("abcd:2345::"), IPMask(ParseIP("ffff:ffff:8000::")), nil},
- {"abcd:2345::/32", ParseIP("abcd:2345::"), IPMask(ParseIP("ffff:ffff::")), nil},
- {"abcd:2344::/31", ParseIP("abcd:2344::"), IPMask(ParseIP("ffff:fffe::")), nil},
- {"abcd:2300::/24", ParseIP("abcd:2300::"), IPMask(ParseIP("ffff:ff00::")), nil},
- {"abcd:2345::/24", nil, nil, &ParseError{"CIDR address", "abcd:2345::/24"}},
- {"2001:DB8::/48", ParseIP("2001:DB8::"), IPMask(ParseIP("ffff:ffff:ffff::")), nil},
+ {"135.104.0.0/32", IPv4(135, 104, 0, 0), &IPNet{IPv4(135, 104, 0, 0), IPv4Mask(255, 255, 255, 255)}, nil},
+ {"0.0.0.0/24", IPv4(0, 0, 0, 0), &IPNet{IPv4(0, 0, 0, 0), IPv4Mask(255, 255, 255, 0)}, nil},
+ {"135.104.0.0/24", IPv4(135, 104, 0, 0), &IPNet{IPv4(135, 104, 0, 0), IPv4Mask(255, 255, 255, 0)}, nil},
+ {"135.104.0.1/32", IPv4(135, 104, 0, 1), &IPNet{IPv4(135, 104, 0, 1), IPv4Mask(255, 255, 255, 255)}, nil},
+ {"135.104.0.1/24", IPv4(135, 104, 0, 1), &IPNet{IPv4(135, 104, 0, 0), IPv4Mask(255, 255, 255, 0)}, nil},
+ {"::1/128", ParseIP("::1"), &IPNet{ParseIP("::1"), IPMask(ParseIP("ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff"))}, nil},
+ {"abcd:2345::/127", ParseIP("abcd:2345::"), &IPNet{ParseIP("abcd:2345::"), IPMask(ParseIP("ffff:ffff:ffff:ffff:ffff:ffff:ffff:fffe"))}, nil},
+ {"abcd:2345::/65", ParseIP("abcd:2345::"), &IPNet{ParseIP("abcd:2345::"), IPMask(ParseIP("ffff:ffff:ffff:ffff:8000::"))}, nil},
+ {"abcd:2345::/64", ParseIP("abcd:2345::"), &IPNet{ParseIP("abcd:2345::"), IPMask(ParseIP("ffff:ffff:ffff:ffff::"))}, nil},
+ {"abcd:2345::/63", ParseIP("abcd:2345::"), &IPNet{ParseIP("abcd:2345::"), IPMask(ParseIP("ffff:ffff:ffff:fffe::"))}, nil},
+ {"abcd:2345::/33", ParseIP("abcd:2345::"), &IPNet{ParseIP("abcd:2345::"), IPMask(ParseIP("ffff:ffff:8000::"))}, nil},
+ {"abcd:2345::/32", ParseIP("abcd:2345::"), &IPNet{ParseIP("abcd:2345::"), IPMask(ParseIP("ffff:ffff::"))}, nil},
+ {"abcd:2344::/31", ParseIP("abcd:2344::"), &IPNet{ParseIP("abcd:2344::"), IPMask(ParseIP("ffff:fffe::"))}, nil},
+ {"abcd:2300::/24", ParseIP("abcd:2300::"), &IPNet{ParseIP("abcd:2300::"), IPMask(ParseIP("ffff:ff00::"))}, nil},
+ {"abcd:2345::/24", ParseIP("abcd:2345::"), &IPNet{ParseIP("abcd:2300::"), IPMask(ParseIP("ffff:ff00::"))}, nil},
+ {"2001:DB8::/48", ParseIP("2001:DB8::"), &IPNet{ParseIP("2001:DB8::"), IPMask(ParseIP("ffff:ffff:ffff::"))}, nil},
+ {"2001:DB8::1/48", ParseIP("2001:DB8::1"), &IPNet{ParseIP("2001:DB8::"), IPMask(ParseIP("ffff:ffff:ffff::"))}, nil},
+ {"192.168.1.1/255.255.255.0", nil, nil, &ParseError{"CIDR address", "192.168.1.1/255.255.255.0"}},
+ {"192.168.1.1/35", nil, nil, &ParseError{"CIDR address", "192.168.1.1/35"}},
+ {"2001:db8::1/-1", nil, nil, &ParseError{"CIDR address", "2001:db8::1/-1"}},
+ {"", nil, nil, &ParseError{"CIDR address", ""}},
}
func TestParseCIDR(t *testing.T) {
for _, tt := range parsecidrtests {
- if ip, mask, err := ParseCIDR(tt.in); !tt.ip.Equal(ip) || !isEqual(mask, tt.mask) || !reflect.DeepEqual(err, tt.err) {
- t.Errorf("ParseCIDR(%q) = %v, %v, %v; want %v, %v, %v", tt.in, ip, mask, err, tt.ip, tt.mask, tt.err)
+ ip, net, err := ParseCIDR(tt.in)
+ if !reflect.DeepEqual(err, tt.err) {
+ t.Errorf("ParseCIDR(%q) = %v, %v; want %v, %v", tt.in, ip, net, tt.ip, tt.net)
+ }
+ if err == nil && (!tt.ip.Equal(ip) || !tt.net.IP.Equal(net.IP) || !isEqual(net.Mask, tt.net.Mask)) {
+ t.Errorf("ParseCIDR(%q) = %v, {%v, %v}; want %v {%v, %v}", tt.in, ip, net.IP, net.Mask, tt.ip, tt.net.IP, tt.net.Mask)
+ }
+ }
+}
+
+var ipnetcontainstests = []struct {
+ ip IP
+ net *IPNet
+ ok bool
+}{
+ {IPv4(172, 16, 1, 1), &IPNet{IPv4(172, 16, 0, 0), CIDRMask(12, 32)}, true},
+ {IPv4(172, 24, 0, 1), &IPNet{IPv4(172, 16, 0, 0), CIDRMask(13, 32)}, false},
+ {IPv4(192, 168, 0, 3), &IPNet{IPv4(192, 168, 0, 0), IPv4Mask(0, 0, 255, 252)}, true},
+ {IPv4(192, 168, 0, 4), &IPNet{IPv4(192, 168, 0, 0), IPv4Mask(0, 255, 0, 252)}, false},
+ {ParseIP("2001:db8:1:2::1"), &IPNet{ParseIP("2001:db8:1::"), CIDRMask(47, 128)}, true},
+ {ParseIP("2001:db8:1:2::1"), &IPNet{ParseIP("2001:db8:2::"), CIDRMask(47, 128)}, false},
+ {ParseIP("2001:db8:1:2::1"), &IPNet{ParseIP("2001:db8:1::"), IPMask(ParseIP("ffff:0:ffff::"))}, true},
+ {ParseIP("2001:db8:1:2::1"), &IPNet{ParseIP("2001:db8:1::"), IPMask(ParseIP("0:0:0:ffff::"))}, false},
+}
+
+func TestIPNetContains(t *testing.T) {
+ for _, tt := range ipnetcontainstests {
+ if ok := tt.net.Contains(tt.ip); ok != tt.ok {
+ t.Errorf("IPNet(%v).Contains(%v) = %v, want %v", tt.net, tt.ip, ok, tt.ok)
+ }
+ }
+}
+
+var ipnetstringtests = []struct {
+ in *IPNet
+ out string
+}{
+ {&IPNet{IPv4(192, 168, 1, 0), CIDRMask(26, 32)}, "192.168.1.0/26"},
+ {&IPNet{IPv4(192, 168, 1, 0), IPv4Mask(255, 0, 255, 0)}, "192.168.1.0/ff00ff00"},
+ {&IPNet{ParseIP("2001:db8::"), CIDRMask(55, 128)}, "2001:db8::/55"},
+ {&IPNet{ParseIP("2001:db8::"), IPMask(ParseIP("8000:f123:0:cafe::"))}, "2001:db8::/8000f1230000cafe0000000000000000"},
+}
+
+func TestIPNetString(t *testing.T) {
+ for _, tt := range ipnetstringtests {
+ if out := tt.in.String(); out != tt.out {
+ t.Errorf("IPNet.String(%v) = %q, want %q", tt.in, out, tt.out)
+ }
+ }
+}
+
+var cidrmasktests = []struct {
+ ones int
+ bits int
+ out IPMask
+}{
+ {0, 32, IPv4Mask(0, 0, 0, 0)},
+ {12, 32, IPv4Mask(255, 240, 0, 0)},
+ {24, 32, IPv4Mask(255, 255, 255, 0)},
+ {32, 32, IPv4Mask(255, 255, 255, 255)},
+ {0, 128, IPMask{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}},
+ {4, 128, IPMask{0xf0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}},
+ {48, 128, IPMask{0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}},
+ {128, 128, IPMask{0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff}},
+ {33, 32, nil},
+ {32, 33, nil},
+ {-1, 128, nil},
+ {128, -1, nil},
+}
+
+func TestCIDRMask(t *testing.T) {
+ for _, tt := range cidrmasktests {
+ if out := CIDRMask(tt.ones, tt.bits); !isEqual(out, tt.out) {
+ t.Errorf("CIDRMask(%v, %v) = %v, want %v", tt.ones, tt.bits, out, tt.out)
+ }
+ }
+}
+
+var (
+ v4addr = IP{192, 168, 0, 1}
+ v4mappedv6addr = IP{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xff, 0xff, 192, 168, 0, 1}
+ v6addr = IP{0x20, 0x1, 0xd, 0xb8, 0, 0, 0, 0, 0, 0, 0x1, 0x23, 0, 0x12, 0, 0x1}
+ v4mask = IPMask{255, 255, 255, 0}
+ v4mappedv6mask = IPMask{0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 255, 255, 255, 0}
+ v6mask = IPMask{0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0, 0, 0, 0, 0, 0, 0, 0}
+ badaddr = IP{192, 168, 0}
+ badmask = IPMask{255, 255, 0}
+ v4maskzero = IPMask{0, 0, 0, 0}
+)
+
+var networknumberandmasktests = []struct {
+ in IPNet
+ out IPNet
+}{
+ {IPNet{v4addr, v4mask}, IPNet{v4addr, v4mask}},
+ {IPNet{v4addr, v4mappedv6mask}, IPNet{v4addr, v4mask}},
+ {IPNet{v4mappedv6addr, v4mappedv6mask}, IPNet{v4addr, v4mask}},
+ {IPNet{v4mappedv6addr, v6mask}, IPNet{v4addr, v4maskzero}},
+ {IPNet{v4addr, v6mask}, IPNet{v4addr, v4maskzero}},
+ {IPNet{v6addr, v6mask}, IPNet{v6addr, v6mask}},
+ {IPNet{v6addr, v4mappedv6mask}, IPNet{v6addr, v4mappedv6mask}},
+ {in: IPNet{v6addr, v4mask}},
+ {in: IPNet{v4addr, badmask}},
+ {in: IPNet{v4mappedv6addr, badmask}},
+ {in: IPNet{v6addr, badmask}},
+ {in: IPNet{badaddr, v4mask}},
+ {in: IPNet{badaddr, v4mappedv6mask}},
+ {in: IPNet{badaddr, v6mask}},
+ {in: IPNet{badaddr, badmask}},
+}
+
+func TestNetworkNumberAndMask(t *testing.T) {
+ for _, tt := range networknumberandmasktests {
+ ip, m := networkNumberAndMask(&tt.in)
+ out := &IPNet{ip, m}
+ if !reflect.DeepEqual(&tt.out, out) {
+ t.Errorf("networkNumberAndMask(%v) = %v; want %v", tt.in, out, &tt.out)
}
}
}
func TestIPAddrFamily(t *testing.T) {
for _, tt := range ipaftests {
if af := tt.in.To4() != nil; af != tt.af4 {
- t.Errorf("verifying IPv4 address family for %#q = %v, want %v", tt.in, af, tt.af4)
+ t.Errorf("verifying IPv4 address family for %q = %v, want %v", tt.in, af, tt.af4)
}
if af := len(tt.in) == IPv6len && tt.in.To4() == nil; af != tt.af6 {
- t.Errorf("verifying IPv6 address family for %#q = %v, want %v", tt.in, af, tt.af6)
+ t.Errorf("verifying IPv6 address family for %q = %v, want %v", tt.in, af, tt.af6)
}
}
}
func TestIPAddrScope(t *testing.T) {
for _, tt := range ipscopetests {
if ok := tt.scope(tt.in); ok != tt.ok {
- t.Errorf("%s(%#q) = %v, want %v", name(tt.scope), tt.in, ok, tt.ok)
+ t.Errorf("%s(%q) = %v, want %v", name(tt.scope), tt.in, ok, tt.ok)
}
}
}