Adding upstream version 1.21.8.upstream/1.21.8

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 542 insertions, 0 deletions

diff --git a/src/net/ip.go b/src/net/ip.go
new file mode 100644
index 0000000..d51ba10
--- /dev/null
+++ b/src/net/ip.go
@@ -0,0 +1,542 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// IP address manipulations
+//
+// IPv4 addresses are 4 bytes; IPv6 addresses are 16 bytes.
+// An IPv4 address can be converted to an IPv6 address by
+// adding a canonical prefix (10 zeros, 2 0xFFs).
+// This library accepts either size of byte slice but always
+// returns 16-byte addresses.
+
+package net
+
+import (
+	"internal/bytealg"
+	"internal/itoa"
+	"net/netip"
+)
+
+// IP address lengths (bytes).
+const (
+	IPv4len = 4
+	IPv6len = 16
+)
+
+// An IP is a single IP address, a slice of bytes.
+// Functions in this package accept either 4-byte (IPv4)
+// or 16-byte (IPv6) slices as input.
+//
+// Note that in this documentation, referring to an
+// IP address as an IPv4 address or an IPv6 address
+// is a semantic property of the address, not just the
+// length of the byte slice: a 16-byte slice can still
+// be an IPv4 address.
+type IP []byte
+
+// An IPMask is a bitmask that can be used to manipulate
+// IP addresses for IP addressing and routing.
+//
+// See type IPNet and func ParseCIDR for details.
+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 {
+	p := make(IP, IPv6len)
+	copy(p, v4InV6Prefix)
+	p[12] = a
+	p[13] = b
+	p[14] = c
+	p[15] = d
+	return p
+}
+
+var v4InV6Prefix = []byte{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xff, 0xff}
+
+// 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, IPv4len)
+	p[0] = a
+	p[1] = b
+	p[2] = c
+	p[3] = d
+	return p
+}
+
+// CIDRMask returns an IPMask consisting of 'ones' 1 bits
+// followed by 0s up to a total length of 'bits' bits.
+// For a mask of this form, CIDRMask is the inverse of IPMask.Size.
+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) // limited broadcast
+	IPv4allsys    = IPv4(224, 0, 0, 1)       // all systems
+	IPv4allrouter = IPv4(224, 0, 0, 2)       // all routers
+	IPv4zero      = IPv4(0, 0, 0, 0)         // all zeros
+)
+
+// Well-known IPv6 addresses
+var (
+	IPv6zero                   = IP{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}
+	IPv6unspecified            = IP{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}
+	IPv6loopback               = IP{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1}
+	IPv6interfacelocalallnodes = IP{0xff, 0x01, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x01}
+	IPv6linklocalallnodes      = IP{0xff, 0x02, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x01}
+	IPv6linklocalallrouters    = IP{0xff, 0x02, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x02}
+)
+
+// IsUnspecified reports whether ip is an unspecified address, either
+// the IPv4 address "0.0.0.0" or the IPv6 address "::".
+func (ip IP) IsUnspecified() bool {
+	return ip.Equal(IPv4zero) || ip.Equal(IPv6unspecified)
+}
+
+// IsLoopback reports whether ip is a loopback address.
+func (ip IP) IsLoopback() bool {
+	if ip4 := ip.To4(); ip4 != nil {
+		return ip4[0] == 127
+	}
+	return ip.Equal(IPv6loopback)
+}
+
+// IsPrivate reports whether ip is a private address, according to
+// RFC 1918 (IPv4 addresses) and RFC 4193 (IPv6 addresses).
+func (ip IP) IsPrivate() bool {
+	if ip4 := ip.To4(); ip4 != nil {
+		// Following RFC 1918, Section 3. Private Address Space which says:
+		//   The Internet Assigned Numbers Authority (IANA) has reserved the
+		//   following three blocks of the IP address space for private internets:
+		//     10.0.0.0        -   10.255.255.255  (10/8 prefix)
+		//     172.16.0.0      -   172.31.255.255  (172.16/12 prefix)
+		//     192.168.0.0     -   192.168.255.255 (192.168/16 prefix)
+		return ip4[0] == 10 ||
+			(ip4[0] == 172 && ip4[1]&0xf0 == 16) ||
+			(ip4[0] == 192 && ip4[1] == 168)
+	}
+	// Following RFC 4193, Section 8. IANA Considerations which says:
+	//   The IANA has assigned the FC00::/7 prefix to "Unique Local Unicast".
+	return len(ip) == IPv6len && ip[0]&0xfe == 0xfc
+}
+
+// IsMulticast reports whether ip is a multicast address.
+func (ip IP) IsMulticast() bool {
+	if ip4 := ip.To4(); ip4 != nil {
+		return ip4[0]&0xf0 == 0xe0
+	}
+	return len(ip) == IPv6len && ip[0] == 0xff
+}
+
+// IsInterfaceLocalMulticast reports whether ip is
+// an interface-local multicast address.
+func (ip IP) IsInterfaceLocalMulticast() bool {
+	return len(ip) == IPv6len && ip[0] == 0xff && ip[1]&0x0f == 0x01
+}
+
+// IsLinkLocalMulticast reports whether ip is a link-local
+// multicast address.
+func (ip IP) IsLinkLocalMulticast() bool {
+	if ip4 := ip.To4(); ip4 != nil {
+		return ip4[0] == 224 && ip4[1] == 0 && ip4[2] == 0
+	}
+	return len(ip) == IPv6len && ip[0] == 0xff && ip[1]&0x0f == 0x02
+}
+
+// IsLinkLocalUnicast reports whether ip is a link-local
+// unicast address.
+func (ip IP) IsLinkLocalUnicast() bool {
+	if ip4 := ip.To4(); ip4 != nil {
+		return ip4[0] == 169 && ip4[1] == 254
+	}
+	return len(ip) == IPv6len && ip[0] == 0xfe && ip[1]&0xc0 == 0x80
+}
+
+// IsGlobalUnicast reports whether ip is a global unicast
+// address.
+//
+// The identification of global unicast addresses uses address type
+// identification as defined in RFC 1122, RFC 4632 and RFC 4291 with
+// the exception of IPv4 directed broadcast addresses.
+// It returns true even if ip is in IPv4 private address space or
+// local IPv6 unicast address space.
+func (ip IP) IsGlobalUnicast() bool {
+	return (len(ip) == IPv4len || len(ip) == IPv6len) &&
+		!ip.Equal(IPv4bcast) &&
+		!ip.IsUnspecified() &&
+		!ip.IsLoopback() &&
+		!ip.IsMulticast() &&
+		!ip.IsLinkLocalUnicast()
+}
+
+// Is p all zeros?
+func isZeros(p IP) bool {
+	for i := 0; i < len(p); i++ {
+		if p[i] != 0 {
+			return false
+		}
+	}
+	return true
+}
+
+// To4 converts the IPv4 address ip to a 4-byte representation.
+// If ip is not an IPv4 address, To4 returns nil.
+func (ip IP) To4() IP {
+	if len(ip) == IPv4len {
+		return ip
+	}
+	if len(ip) == IPv6len &&
+		isZeros(ip[0:10]) &&
+		ip[10] == 0xff &&
+		ip[11] == 0xff {
+		return ip[12:16]
+	}
+	return nil
+}
+
+// To16 converts the IP address ip to a 16-byte representation.
+// If ip is not an IP address (it is the wrong length), To16 returns nil.
+func (ip IP) To16() IP {
+	if len(ip) == IPv4len {
+		return IPv4(ip[0], ip[1], ip[2], ip[3])
+	}
+	if len(ip) == IPv6len {
+		return ip
+	}
+	return nil
+}
+
+// Default route masks for IPv4.
+var (
+	classAMask = IPv4Mask(0xff, 0, 0, 0)
+	classBMask = IPv4Mask(0xff, 0xff, 0, 0)
+	classCMask = IPv4Mask(0xff, 0xff, 0xff, 0)
+)
+
+// DefaultMask returns the default IP mask for the IP address ip.
+// Only IPv4 addresses have default masks; DefaultMask returns
+// nil if ip is not a valid IPv4 address.
+func (ip IP) DefaultMask() IPMask {
+	if ip = ip.To4(); ip == nil {
+		return nil
+	}
+	switch {
+	case ip[0] < 0x80:
+		return classAMask
+	case ip[0] < 0xC0:
+		return classBMask
+	default:
+		return classCMask
+	}
+}
+
+func allFF(b []byte) bool {
+	for _, c := range b {
+		if c != 0xff {
+			return false
+		}
+	}
+	return true
+}
+
+// Mask returns the result of masking the IP address ip with mask.
+func (ip IP) Mask(mask IPMask) IP {
+	if len(mask) == IPv6len && len(ip) == IPv4len && allFF(mask[:12]) {
+		mask = mask[12:]
+	}
+	if len(mask) == IPv4len && len(ip) == IPv6len && bytealg.Equal(ip[:12], v4InV6Prefix) {
+		ip = ip[12:]
+	}
+	n := len(ip)
+	if n != len(mask) {
+		return nil
+	}
+	out := make(IP, n)
+	for i := 0; i < n; i++ {
+		out[i] = ip[i] & mask[i]
+	}
+	return out
+}
+
+// String returns the string form of the IP address ip.
+// It returns one of 4 forms:
+//   - "<nil>", if ip has length 0
+//   - dotted decimal ("192.0.2.1"), if ip is an IPv4 or IP4-mapped IPv6 address
+//   - IPv6 conforming to RFC 5952 ("2001:db8::1"), if ip is a valid IPv6 address
+//   - the hexadecimal form of ip, without punctuation, if no other cases apply
+func (ip IP) String() string {
+	if len(ip) == 0 {
+		return "<nil>"
+	}
+
+	if len(ip) != IPv4len && len(ip) != IPv6len {
+		return "?" + hexString(ip)
+	}
+	// If IPv4, use dotted notation.
+	if p4 := ip.To4(); len(p4) == IPv4len {
+		return netip.AddrFrom4([4]byte(p4)).String()
+	}
+	return netip.AddrFrom16([16]byte(ip)).String()
+}
+
+func hexString(b []byte) string {
+	s := make([]byte, len(b)*2)
+	for i, tn := range b {
+		s[i*2], s[i*2+1] = hexDigit[tn>>4], hexDigit[tn&0xf]
+	}
+	return string(s)
+}
+
+// ipEmptyString is like ip.String except that it returns
+// an empty string when ip is unset.
+func ipEmptyString(ip IP) string {
+	if len(ip) == 0 {
+		return ""
+	}
+	return ip.String()
+}
+
+// MarshalText implements the encoding.TextMarshaler interface.
+// The encoding is the same as returned by String, with one exception:
+// When len(ip) is zero, it returns an empty slice.
+func (ip IP) MarshalText() ([]byte, error) {
+	if len(ip) == 0 {
+		return []byte(""), nil
+	}
+	if len(ip) != IPv4len && len(ip) != IPv6len {
+		return nil, &AddrError{Err: "invalid IP address", Addr: hexString(ip)}
+	}
+	return []byte(ip.String()), nil
+}
+
+// UnmarshalText implements the encoding.TextUnmarshaler interface.
+// The IP address is expected in a form accepted by ParseIP.
+func (ip *IP) UnmarshalText(text []byte) error {
+	if len(text) == 0 {
+		*ip = nil
+		return nil
+	}
+	s := string(text)
+	x := ParseIP(s)
+	if x == nil {
+		return &ParseError{Type: "IP address", Text: s}
+	}
+	*ip = x
+	return nil
+}
+
+// Equal reports whether ip and x are the same IP address.
+// An IPv4 address and that same address in IPv6 form are
+// considered to be equal.
+func (ip IP) Equal(x IP) bool {
+	if len(ip) == len(x) {
+		return bytealg.Equal(ip, x)
+	}
+	if len(ip) == IPv4len && len(x) == IPv6len {
+		return bytealg.Equal(x[0:12], v4InV6Prefix) && bytealg.Equal(ip, x[12:])
+	}
+	if len(ip) == IPv6len && len(x) == IPv4len {
+		return bytealg.Equal(ip[0:12], v4InV6Prefix) && bytealg.Equal(ip[12:], x)
+	}
+	return false
+}
+
+func (ip IP) matchAddrFamily(x IP) bool {
+	return ip.To4() != nil && x.To4() != nil || ip.To16() != nil && ip.To4() == nil && x.To16() != nil && x.To4() == nil
+}
+
+// If mask is a sequence of 1 bits followed by 0 bits,
+// return the number of 1 bits.
+func simpleMaskLength(mask IPMask) int {
+	var n int
+	for i, v := range mask {
+		if v == 0xff {
+			n += 8
+			continue
+		}
+		// found non-ff byte
+		// count 1 bits
+		for v&0x80 != 0 {
+			n++
+			v <<= 1
+		}
+		// rest must be 0 bits
+		if v != 0 {
+			return -1
+		}
+		for i++; i < len(mask); i++ {
+			if mask[i] != 0 {
+				return -1
+			}
+		}
+		break
+	}
+	return n
+}
+
+// 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
+}
+
+// String returns the hexadecimal form of m, with no punctuation.
+func (m IPMask) String() string {
+	if len(m) == 0 {
+		return "<nil>"
+	}
+	return hexString(m)
+}
+
+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
+}
+
+// Network returns the address's network name, "ip+net".
+func (n *IPNet) Network() string { return "ip+net" }
+
+// String returns the CIDR notation of n like "192.0.2.0/24"
+// 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 "198.51.100.0/c000ff00".
+func (n *IPNet) String() string {
+	if n == nil {
+		return "<nil>"
+	}
+	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() + "/" + itoa.Uitoa(uint(l))
+}
+
+// ParseIP parses s as an IP address, returning the result.
+// The string s can be in IPv4 dotted decimal ("192.0.2.1"), IPv6
+// ("2001:db8::68"), or IPv4-mapped IPv6 ("::ffff:192.0.2.1") form.
+// If s is not a valid textual representation of an IP address,
+// ParseIP returns nil.
+func ParseIP(s string) IP {
+	if addr, valid := parseIP(s); valid {
+		return IP(addr[:])
+	}
+	return nil
+}
+
+func parseIP(s string) ([16]byte, bool) {
+	ip, err := netip.ParseAddr(s)
+	if err != nil || ip.Zone() != "" {
+		return [16]byte{}, false
+	}
+	return ip.As16(), true
+}
+
+// ParseCIDR parses s as a CIDR notation IP address and prefix length,
+// like "192.0.2.0/24" or "2001:db8::/32", as defined in
+// RFC 4632 and RFC 4291.
+//
+// It returns the IP address and the network implied by the IP and
+// prefix length.
+// For example, ParseCIDR("192.0.2.1/24") returns the IP address
+// 192.0.2.1 and the network 192.0.2.0/24.
+func ParseCIDR(s string) (IP, *IPNet, error) {
+	i := bytealg.IndexByteString(s, '/')
+	if i < 0 {
+		return nil, nil, &ParseError{Type: "CIDR address", Text: s}
+	}
+	addr, mask := s[:i], s[i+1:]
+
+	ipAddr, err := netip.ParseAddr(addr)
+	if err != nil || ipAddr.Zone() != "" {
+		return nil, nil, &ParseError{Type: "CIDR address", Text: s}
+	}
+
+	n, i, ok := dtoi(mask)
+	if !ok || i != len(mask) || n < 0 || n > ipAddr.BitLen() {
+		return nil, nil, &ParseError{Type: "CIDR address", Text: s}
+	}
+	m := CIDRMask(n, ipAddr.BitLen())
+	addr16 := ipAddr.As16()
+	return IP(addr16[:]), &IPNet{IP: IP(addr16[:]).Mask(m), Mask: m}, nil
+}
+
+func copyIP(x IP) IP {
+	y := make(IP, len(x))
+	copy(y, x)
+	return y
+}