2fd31cd3e0
* plugin/metadata: some cleanups Name to provider.go as that's what being defined right now in the file. Use request.Request because that's done in variables.go anyway. Name the main storage M, because there is no further meaning behind. Remove superfluous methods Signed-off-by: Miek Gieben <miek@miek.nl> * Fix test Signed-off-by: Miek Gieben <miek@miek.nl>
104 lines
2.4 KiB
Go
104 lines
2.4 KiB
Go
package variables
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import (
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"encoding/binary"
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"fmt"
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"net"
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"strconv"
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"github.com/coredns/coredns/request"
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)
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const (
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queryName = "qname"
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queryType = "qtype"
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clientIP = "client_ip"
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clientPort = "client_port"
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protocol = "protocol"
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serverIP = "server_ip"
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serverPort = "server_port"
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)
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// All is a list of available variables provided by GetMetadataValue
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var All = []string{queryName, queryType, clientIP, clientPort, protocol, serverIP, serverPort}
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// GetValue calculates and returns the data specified by the variable name.
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// Supported varNames are listed in allProvidedVars.
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func GetValue(state request.Request, varName string) ([]byte, error) {
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switch varName {
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case queryName:
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return []byte(state.QName()), nil
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case queryType:
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return uint16ToWire(state.QType()), nil
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case clientIP:
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return ipToWire(state.Family(), state.IP())
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case clientPort:
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return portToWire(state.Port())
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case protocol:
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return []byte(state.Proto()), nil
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case serverIP:
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ip, _, err := net.SplitHostPort(state.W.LocalAddr().String())
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if err != nil {
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ip = state.W.RemoteAddr().String()
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}
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return ipToWire(state.Family(), ip)
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case serverPort:
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_, port, err := net.SplitHostPort(state.W.LocalAddr().String())
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if err != nil {
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port = "0"
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}
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return portToWire(port)
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}
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return nil, fmt.Errorf("unable to extract data for variable %s", varName)
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}
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// uint16ToWire writes unit16 to wire/binary format
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func uint16ToWire(data uint16) []byte {
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buf := make([]byte, 2)
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binary.BigEndian.PutUint16(buf, uint16(data))
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return buf
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}
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// ipToWire writes IP address to wire/binary format, 4 or 16 bytes depends on IPV4 or IPV6.
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func ipToWire(family int, ipAddr string) ([]byte, error) {
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switch family {
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case 1:
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return net.ParseIP(ipAddr).To4(), nil
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case 2:
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return net.ParseIP(ipAddr).To16(), nil
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}
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return nil, fmt.Errorf("invalid IP address family (i.e. version) %d", family)
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}
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// portToWire writes port to wire/binary format, 2 bytes
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func portToWire(portStr string) ([]byte, error) {
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port, err := strconv.ParseUint(portStr, 10, 16)
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if err != nil {
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return nil, err
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}
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return uint16ToWire(uint16(port)), nil
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}
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// Family returns the family of the transport, 1 for IPv4 and 2 for IPv6.
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func family(ip net.Addr) int {
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var a net.IP
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if i, ok := ip.(*net.UDPAddr); ok {
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a = i.IP
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}
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if i, ok := ip.(*net.TCPAddr); ok {
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a = i.IP
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}
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if a.To4() != nil {
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return 1
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}
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return 2
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}
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