91 lines
1.9 KiB
Go
91 lines
1.9 KiB
Go
package powerdns_recursor
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import (
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"errors"
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"fmt"
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"net"
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"time"
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"github.com/influxdata/telegraf"
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)
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// V3 (4.6.0+) Protocol:
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// Standard unix stream socket
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// Synchronous request / response
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// Data structure:
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// status: uint32
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// dataLength: size_t
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// data: byte[dataLength]
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func gatherFromV3Server(address string, acc telegraf.Accumulator) error {
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conn, err := net.Dial("unix", address)
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if err != nil {
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return err
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}
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defer conn.Close()
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if err := conn.SetDeadline(time.Now().Add(defaultTimeout)); err != nil {
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return err
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}
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// Write 4-byte response code.
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if _, err = conn.Write([]byte{0, 0, 0, 0}); err != nil {
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return err
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}
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command := []byte("get-all")
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if err := writeNativeUIntToConn(conn, uint(len(command))); err != nil {
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return err
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}
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if _, err = conn.Write(command); err != nil {
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return err
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}
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// Now read the response.
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status := make([]byte, 4)
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n, err := conn.Read(status)
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if err != nil {
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return err
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}
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if n == 0 {
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return errors.New("no status code received")
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}
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responseLength, err := readNativeUIntFromConn(conn)
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if err != nil {
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return err
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}
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if responseLength == 0 {
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return errors.New("received data length was '0'")
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}
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// Don't allow more than 64kb of data to prevent DOS / issues
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// with architecture mismatch. V2 protocol allowed for up to
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// 16kb, so 64kb should give us a pretty good margin for anything
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// that has been added since.
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if responseLength > 64*1024 {
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return fmt.Errorf("received data length was '%d', we only allow up to '%d'", responseLength, 64*1024)
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}
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data := make([]byte, responseLength)
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n, err = conn.Read(data)
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if err != nil {
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return err
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}
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if uint(n) != responseLength {
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return fmt.Errorf("no data received, expected '%v' bytes but got '%v'", responseLength, n)
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}
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// Process data
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metrics := string(data)
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fields := parseResponse(metrics)
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// Add server socket as a tag
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tags := map[string]string{"server": address}
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acc.AddFields("powerdns_recursor", fields, tags)
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return nil
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}
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