127 lines
3.1 KiB
Go
127 lines
3.1 KiB
Go
package netutils
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import "net"
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// IPScope is the scope of the IP address.
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type IPScope int8
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// Defined IP Scopes.
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const (
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Invalid IPScope = iota - 1
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Undefined
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HostLocal
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LinkLocal
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SiteLocal
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Global
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LocalMulticast
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GlobalMulticast
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)
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// ClassifyIP returns the network scope of the given IP address.
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// Deprecated: Please use the new GetIPScope instead.
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func ClassifyIP(ip net.IP) IPScope {
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return GetIPScope(ip)
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}
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// GetIPScope returns the network scope of the given IP address.
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func GetIPScope(ip net.IP) IPScope { //nolint:gocognit
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if ip4 := ip.To4(); ip4 != nil {
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// IPv4
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switch {
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case ip4[0] == 127:
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// 127.0.0.0/8 (RFC1918)
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return HostLocal
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case ip4[0] == 169 && ip4[1] == 254:
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// 169.254.0.0/16 (RFC3927)
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return LinkLocal
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case ip4[0] == 10:
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// 10.0.0.0/8 (RFC1918)
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return SiteLocal
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case ip4[0] == 100 && ip4[1]&0b11000000 == 64:
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// 100.64.0.0/10 (RFC6598)
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return SiteLocal
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case ip4[0] == 172 && ip4[1]&0b11110000 == 16:
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// 172.16.0.0/12 (RFC1918)
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return SiteLocal
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case ip4[0] == 192 && ip4[1] == 0 && ip4[2] == 2:
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// 192.0.2.0/24 (TEST-NET-1, RFC5737)
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return Invalid
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case ip4[0] == 192 && ip4[1] == 168:
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// 192.168.0.0/16 (RFC1918)
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return SiteLocal
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case ip4[0] == 198 && ip4[1] == 51 && ip4[2] == 100:
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// 198.51.100.0/24 (TEST-NET-2, RFC5737)
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return Invalid
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case ip4[0] == 203 && ip4[1] == 0 && ip4[2] == 113:
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// 203.0.113.0/24 (TEST-NET-3, RFC5737)
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return Invalid
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case ip4[0] == 224:
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// 224.0.0.0/8 (RFC5771)
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return LocalMulticast
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case ip4[0] == 233 && ip4[1] == 252 && ip4[2] == 0:
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// 233.252.0.0/24 (MCAST-TEST-NET; RFC5771, RFC6676)
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return Invalid
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case ip4[0] >= 225 && ip4[0] <= 238:
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// 225.0.0.0/8 - 238.0.0.0/8 (RFC5771)
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return GlobalMulticast
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case ip4[0] == 239:
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// 239.0.0.0/8 (RFC2365)
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return LocalMulticast
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case ip4[0] == 255 && ip4[1] == 255 && ip4[2] == 255 && ip4[3] == 255:
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// 255.255.255.255/32
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return LocalMulticast
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case ip4[0] >= 240:
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// 240.0.0.0/8 - 255.0.0.0/8 (minus 255.255.255.255/32)
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return Invalid
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default:
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return Global
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}
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} else if len(ip) == net.IPv6len {
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// IPv6
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switch {
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case ip.Equal(net.IPv6loopback):
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return HostLocal
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case ip[0]&0xfe == 0xfc:
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// fc00::/7
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return SiteLocal
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case ip[0] == 0xfe && ip[1]&0xc0 == 0x80:
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// fe80::/10
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return LinkLocal
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case ip[0] == 0xff && ip[1] <= 0x05:
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// ff00::/16 - ff05::/16
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return LocalMulticast
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case ip[0] == 0xff:
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// other ff00::/8
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return GlobalMulticast
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default:
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return Global
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}
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}
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return Invalid
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}
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// IsLocalhost returns whether the IP refers to the host itself.
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func (scope IPScope) IsLocalhost() bool {
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return scope == HostLocal
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}
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// IsLAN returns true if the scope is site-local or link-local.
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func (scope IPScope) IsLAN() bool {
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switch scope { //nolint:exhaustive // Looking for something specific.
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case SiteLocal, LinkLocal, LocalMulticast:
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return true
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default:
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return false
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}
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}
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// IsGlobal returns true if the scope is global.
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func (scope IPScope) IsGlobal() bool {
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switch scope { //nolint:exhaustive // Looking for something specific.
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case Global, GlobalMulticast:
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return true
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default:
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return false
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}
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}
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