net: change the internal form of IPMask for IPv4
This CL changes the internal form of IPMask for IPv4
from 16-byte to 4-byte, also adds Size method to IPMask
struct and changes output string format of IPMask.String
method.
R=rsc
CC=golang-dev
https://golang.org/cl/4950046
diff --git a/src/pkg/net/ip.go b/src/pkg/net/ip.go
index 474cec9..77c11ab 100644
--- a/src/pkg/net/ip.go
+++ b/src/pkg/net/ip.go
@@ -21,8 +21,8 @@
)
// An IP is a single IP address, an array of bytes.
-// Functions in this package accept either 4-byte (IP v4)
-// or 16-byte (IP v6) arrays as input. Unless otherwise
+// 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.
@@ -51,17 +51,14 @@
var v4InV6Prefix = []byte{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xff, 0xff}
-// IPv4Mask returns the IP mask (in 16-byte form) of the
+// IPv4Mask returns the IP mask (in 4-byte form) of the
// IPv4 mask a.b.c.d.
func IPv4Mask(a, b, c, d byte) IPMask {
- p := make(IPMask, IPv6len)
- for i := 0; i < 12; i++ {
- p[i] = 0xff
- }
- p[12] = a
- p[13] = b
- p[14] = c
- p[15] = d
+ p := make(IPMask, IPv4len)
+ p[0] = a
+ p[1] = b
+ p[2] = c
+ p[3] = d
return p
}
@@ -213,13 +210,13 @@
// Mask returns the result of masking the IP address ip with mask.
func (ip IP) Mask(mask IPMask) IP {
- n := len(ip)
if len(mask) == IPv6len && len(ip) == IPv4len && allFF(mask[:12]) {
mask = mask[12:]
}
if len(mask) == IPv4len && len(ip) == IPv6len && bytesEqual(ip[:12], v4InV6Prefix) {
ip = ip[12:]
}
+ n := len(ip)
if n != len(mask) {
return nil
}
@@ -238,7 +235,7 @@
p := ip
if len(ip) == 0 {
- return ""
+ return "<nil>"
}
// If IPv4, use dotted notation.
@@ -345,25 +342,27 @@
return n
}
-// String returns the string representation of mask.
-// If the mask is in the canonical form--ones followed by zeros--the
-// string representation is just the decimal number of ones.
-// If the mask is in a non-canonical form, it is formatted
-// as an IP address.
-func (mask IPMask) String() string {
- switch len(mask) {
- case IPv4len:
- n := simpleMaskLength(mask)
- if n >= 0 {
- return itod(uint(n + (IPv6len-IPv4len)*8))
- }
- case IPv6len:
- n := simpleMaskLength(mask)
- if n >= 12*8 {
- return itod(uint(n - 12*8))
- }
+// Size returns the number of leading ones and total bits in the mask.
+// If the mask is not in the canonical form--ones followed by zeros--then
+// Size returns 0, 0.
+func (m IPMask) Size() (ones, bits int) {
+ ones, bits = simpleMaskLength(m), len(m)*8
+ if ones == -1 {
+ return 0, 0
}
- return IP(mask).String()
+ return
+}
+
+// String returns the hexadecimal form of m, with no punctuation.
+func (m IPMask) String() string {
+ s := ""
+ for _, b := range m {
+ s += itox(uint(b), 2)
+ }
+ if len(s) == 0 {
+ return "<nil>"
+ }
+ return s
}
// Parse IPv4 address (d.d.d.d).
@@ -535,7 +534,7 @@
}
// ParseCIDR parses s as a CIDR notation IP address and mask,
-// like "192.168.100.1/24", "2001:DB8::/48", as defined in
+// 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) {
i := byteIndex(s, '/')
@@ -571,8 +570,12 @@
}
}
// address must not have any bits not in mask
- for i := range ip {
- if ip[i]&^mask[i] != 0 {
+ 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}
}
}
diff --git a/src/pkg/net/ip_test.go b/src/pkg/net/ip_test.go
index b189b10..5064783 100644
--- a/src/pkg/net/ip_test.go
+++ b/src/pkg/net/ip_test.go
@@ -49,22 +49,15 @@
out string
}{
// cf. RFC 5952 (A Recommendation for IPv6 Address Text Representation)
- {IP{0x20, 0x1, 0xd, 0xb8, 0, 0, 0, 0, 0, 0, 0x1, 0x23, 0, 0x12, 0, 0x1},
- "2001:db8::123:12:1"},
- {IP{0x20, 0x1, 0xd, 0xb8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x1},
- "2001:db8::1"},
- {IP{0x20, 0x1, 0xd, 0xb8, 0, 0, 0, 0x1, 0, 0, 0, 0x1, 0, 0, 0, 0x1},
- "2001:db8:0:1:0:1:0:1"},
- {IP{0x20, 0x1, 0xd, 0xb8, 0, 0x1, 0, 0, 0, 0x1, 0, 0, 0, 0x1, 0, 0},
- "2001:db8:1:0:1:0:1:0"},
- {IP{0x20, 0x1, 0, 0, 0, 0, 0, 0, 0, 0x1, 0, 0, 0, 0, 0, 0x1},
- "2001::1:0:0:1"},
- {IP{0x20, 0x1, 0xd, 0xb8, 0, 0, 0, 0, 0, 0x1, 0, 0, 0, 0, 0, 0},
- "2001:db8:0:0:1::"},
- {IP{0x20, 0x1, 0xd, 0xb8, 0, 0, 0, 0, 0, 0x1, 0, 0, 0, 0, 0, 0x1},
- "2001:db8::1:0:0:1"},
- {IP{0x20, 0x1, 0xD, 0xB8, 0, 0, 0, 0, 0, 0xA, 0, 0xB, 0, 0xC, 0, 0xD},
- "2001:db8::a:b:c:d"},
+ {IP{0x20, 0x1, 0xd, 0xb8, 0, 0, 0, 0, 0, 0, 0x1, 0x23, 0, 0x12, 0, 0x1}, "2001:db8::123:12:1"},
+ {IP{0x20, 0x1, 0xd, 0xb8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x1}, "2001:db8::1"},
+ {IP{0x20, 0x1, 0xd, 0xb8, 0, 0, 0, 0x1, 0, 0, 0, 0x1, 0, 0, 0, 0x1}, "2001:db8:0:1:0:1:0:1"},
+ {IP{0x20, 0x1, 0xd, 0xb8, 0, 0x1, 0, 0, 0, 0x1, 0, 0, 0, 0x1, 0, 0}, "2001:db8:1:0:1:0:1:0"},
+ {IP{0x20, 0x1, 0, 0, 0, 0, 0, 0, 0, 0x1, 0, 0, 0, 0, 0, 0x1}, "2001::1:0:0:1"},
+ {IP{0x20, 0x1, 0xd, 0xb8, 0, 0, 0, 0, 0, 0x1, 0, 0, 0, 0, 0, 0}, "2001:db8:0:0:1::"},
+ {IP{0x20, 0x1, 0xd, 0xb8, 0, 0, 0, 0, 0, 0x1, 0, 0, 0, 0, 0, 0x1}, "2001:db8::1:0:0:1"},
+ {IP{0x20, 0x1, 0xD, 0xB8, 0, 0, 0, 0, 0, 0xA, 0, 0xB, 0, 0xC, 0, 0xD}, "2001:db8::a:b:c:d"},
+ {nil, "<nil>"},
}
func TestIPString(t *testing.T) {
@@ -75,6 +68,46 @@
}
}
+var ipmasktests = []struct {
+ in IP
+ mask IPMask
+ out IP
+}{
+ {IPv4(192, 168, 1, 127), IPv4Mask(255, 255, 255, 128), IPv4(192, 168, 1, 0)},
+ {IPv4(192, 168, 1, 127), IPMask(ParseIP("255.255.255.192")), IPv4(192, 168, 1, 64)},
+ {IPv4(192, 168, 1, 127), IPMask(ParseIP("ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffe0")), IPv4(192, 168, 1, 96)},
+ {IPv4(192, 168, 1, 127), IPv4Mask(255, 0, 255, 0), IPv4(192, 0, 1, 0)},
+ {ParseIP("2001:db8::1"), IPMask(ParseIP("ffff:ff80::")), ParseIP("2001:d80::")},
+ {ParseIP("2001:db8::1"), IPMask(ParseIP("f0f0:0f0f::")), ParseIP("2000:d08::")},
+}
+
+func TestIPMask(t *testing.T) {
+ for _, tt := range ipmasktests {
+ if out := tt.in.Mask(tt.mask); out == nil || !tt.out.Equal(out) {
+ t.Errorf("IP(%v).Mask(%v) = %v, want %v", tt.in, tt.mask, out, tt.out)
+ }
+ }
+}
+
+var ipmaskstringtests = []struct {
+ in IPMask
+ out string
+}{
+ {IPv4Mask(255, 255, 255, 240), "fffffff0"},
+ {IPv4Mask(255, 0, 128, 0), "ff008000"},
+ {IPMask(ParseIP("ffff:ff80::")), "ffffff80000000000000000000000000"},
+ {IPMask(ParseIP("ef00:ff80::cafe:0")), "ef00ff800000000000000000cafe0000"},
+ {nil, "<nil>"},
+}
+
+func TestIPMaskString(t *testing.T) {
+ for _, tt := range ipmaskstringtests {
+ if out := tt.in.String(); out != tt.out {
+ t.Errorf("IPMask.String(%v) = %q, want %q", tt.in, out, tt.out)
+ }
+ }
+}
+
var parsecidrtests = []struct {
in string
ip IP
@@ -101,7 +134,7 @@
func TestParseCIDR(t *testing.T) {
for _, tt := range parsecidrtests {
- if ip, mask, err := ParseCIDR(tt.in); !isEqual(ip, tt.ip) || !isEqual(mask, tt.mask) || !reflect.DeepEqual(err, tt.err) {
+ 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)
}
}
