161 lines
3.3 KiB
Go
161 lines
3.3 KiB
Go
package dns_query
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import (
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"errors"
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"fmt"
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"github.com/miekg/dns"
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"net"
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"strconv"
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"time"
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"github.com/influxdata/telegraf"
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"github.com/influxdata/telegraf/plugins/inputs"
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)
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type DnsQuery struct {
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// Domains or subdomains to query
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Domains []string
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// Server to query
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Servers []string
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// Record type
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RecordType string `toml:"record_type"`
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// DNS server port number
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Port int
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// Dns query timeout in seconds. 0 means no timeout
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Timeout int
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}
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var sampleConfig = `
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## servers to query
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servers = ["8.8.8.8"] # required
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## Domains or subdomains to query. "."(root) is default
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domains = ["."] # optional
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## Query record type. Default is "A"
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## Posible values: A, AAAA, CNAME, MX, NS, PTR, TXT, SOA, SPF, SRV.
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record_type = "A" # optional
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## Dns server port. 53 is default
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port = 53 # optional
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## Query timeout in seconds. Default is 2 seconds
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timeout = 2 # optional
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`
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func (d *DnsQuery) SampleConfig() string {
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return sampleConfig
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}
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func (d *DnsQuery) Description() string {
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return "Query given DNS server and gives statistics"
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}
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func (d *DnsQuery) Gather(acc telegraf.Accumulator) error {
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d.setDefaultValues()
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for _, domain := range d.Domains {
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for _, server := range d.Servers {
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dnsQueryTime, err := d.getDnsQueryTime(domain, server)
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acc.AddError(err)
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tags := map[string]string{
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"server": server,
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"domain": domain,
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"record_type": d.RecordType,
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}
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fields := map[string]interface{}{"query_time_ms": dnsQueryTime}
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acc.AddFields("dns_query", fields, tags)
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}
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}
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return nil
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}
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func (d *DnsQuery) setDefaultValues() {
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if len(d.RecordType) == 0 {
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d.RecordType = "NS"
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}
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if len(d.Domains) == 0 {
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d.Domains = []string{"."}
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d.RecordType = "NS"
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}
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if d.Port == 0 {
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d.Port = 53
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}
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if d.Timeout == 0 {
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d.Timeout = 2
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}
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}
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func (d *DnsQuery) getDnsQueryTime(domain string, server string) (float64, error) {
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dnsQueryTime := float64(0)
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c := new(dns.Client)
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c.ReadTimeout = time.Duration(d.Timeout) * time.Second
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m := new(dns.Msg)
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recordType, err := d.parseRecordType()
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if err != nil {
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return dnsQueryTime, err
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}
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m.SetQuestion(dns.Fqdn(domain), recordType)
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m.RecursionDesired = true
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r, rtt, err := c.Exchange(m, net.JoinHostPort(server, strconv.Itoa(d.Port)))
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if err != nil {
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return dnsQueryTime, err
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}
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if r.Rcode != dns.RcodeSuccess {
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return dnsQueryTime, errors.New(fmt.Sprintf("Invalid answer name %s after %s query for %s\n", domain, d.RecordType, domain))
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}
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dnsQueryTime = float64(rtt.Nanoseconds()) / 1e6
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return dnsQueryTime, nil
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}
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func (d *DnsQuery) parseRecordType() (uint16, error) {
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var recordType uint16
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var error error
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switch d.RecordType {
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case "A":
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recordType = dns.TypeA
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case "AAAA":
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recordType = dns.TypeAAAA
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case "ANY":
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recordType = dns.TypeANY
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case "CNAME":
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recordType = dns.TypeCNAME
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case "MX":
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recordType = dns.TypeMX
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case "NS":
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recordType = dns.TypeNS
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case "PTR":
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recordType = dns.TypePTR
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case "SOA":
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recordType = dns.TypeSOA
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case "SPF":
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recordType = dns.TypeSPF
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case "SRV":
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recordType = dns.TypeSRV
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case "TXT":
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recordType = dns.TypeTXT
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default:
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error = errors.New(fmt.Sprintf("Record type %s not recognized", d.RecordType))
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}
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return recordType, error
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}
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func init() {
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inputs.Add("dns_query", func() telegraf.Input {
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return &DnsQuery{}
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})
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}
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