diff options
Diffstat (limited to 'src/go/plugin/go.d/modules/dnsmasq/collect.go')
-rw-r--r-- | src/go/plugin/go.d/modules/dnsmasq/collect.go | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/src/go/plugin/go.d/modules/dnsmasq/collect.go b/src/go/plugin/go.d/modules/dnsmasq/collect.go new file mode 100644 index 000000000..9f3f963f0 --- /dev/null +++ b/src/go/plugin/go.d/modules/dnsmasq/collect.go @@ -0,0 +1,139 @@ +// SPDX-License-Identifier: GPL-3.0-or-later + +package dnsmasq + +import ( + "fmt" + "strconv" + "strings" + + "github.com/miekg/dns" +) + +func (d *Dnsmasq) collect() (map[string]int64, error) { + mx := make(map[string]int64) + + if err := d.collectCacheStatistics(mx); err != nil { + return nil, err + } + + return mx, nil +} + +func (d *Dnsmasq) collectCacheStatistics(mx map[string]int64) error { + /* + ;; flags: qr aa rd ra; QUERY: 7, ANSWER: 7, AUTHORITY: 0, ADDITIONAL: 0 + + ;; QUESTION SECTION: + ;cachesize.bind. CH TXT + ;insertions.bind. CH TXT + ;evictions.bind. CH TXT + ;hits.bind. CH TXT + ;misses.bind. CH TXT + ;auth.bind. CH TXT + ;servers.bind. CH TXT + + ;; ANSWER SECTION: + cachesize.bind. 0 CH TXT "150" + insertions.bind. 0 CH TXT "1" + evictions.bind. 0 CH TXT "0" + hits.bind. 0 CH TXT "176" + misses.bind. 0 CH TXT "4" + auth.bind. 0 CH TXT "0" + servers.bind. 0 CH TXT "10.0.0.1#53 0 0" "1.1.1.1#53 4 3" "1.0.0.1#53 3 0" + */ + + questions := []string{ + "servers.bind.", + "cachesize.bind.", + "insertions.bind.", + "evictions.bind.", + "hits.bind.", + "misses.bind.", + // auth.bind query is only supported if dnsmasq has been built to support running as an authoritative name server + // See https://github.com/netdata/netdata/issues/13766 + //"auth.bind.", + } + + for _, q := range questions { + resp, err := d.query(q) + if err != nil { + return err + } + + for _, a := range resp.Answer { + txt, ok := a.(*dns.TXT) + if !ok { + continue + } + + idx := strings.IndexByte(txt.Hdr.Name, '.') + if idx == -1 { + continue + } + + name := txt.Hdr.Name[:idx] + + switch name { + case "servers": + for _, entry := range txt.Txt { + parts := strings.Fields(entry) + if len(parts) != 3 { + return fmt.Errorf("parse %s (%s): unexpected format", txt.Hdr.Name, entry) + } + queries, err := strconv.ParseFloat(parts[1], 64) + if err != nil { + return fmt.Errorf("parse '%s' (%s): %v", txt.Hdr.Name, entry, err) + } + failedQueries, err := strconv.ParseFloat(parts[2], 64) + if err != nil { + return fmt.Errorf("parse '%s' (%s): %v", txt.Hdr.Name, entry, err) + } + + mx["queries"] += int64(queries) + mx["failed_queries"] += int64(failedQueries) + } + case "cachesize", "insertions", "evictions", "hits", "misses", "auth": + if len(txt.Txt) != 1 { + return fmt.Errorf("parse '%s' (%v): unexpected format", txt.Hdr.Name, txt.Txt) + } + v, err := strconv.ParseFloat(txt.Txt[0], 64) + if err != nil { + return fmt.Errorf("parse '%s' (%s): %v", txt.Hdr.Name, txt.Txt[0], err) + } + + mx[name] = int64(v) + } + } + } + + return nil +} + +func (d *Dnsmasq) query(question string) (*dns.Msg, error) { + msg := &dns.Msg{ + MsgHdr: dns.MsgHdr{ + Id: dns.Id(), + RecursionDesired: true, + }, + Question: []dns.Question{ + {Name: question, Qtype: dns.TypeTXT, Qclass: dns.ClassCHAOS}, + }, + } + + r, _, err := d.dnsClient.Exchange(msg, d.Address) + if err != nil { + return nil, err + } + + if r == nil { + return nil, fmt.Errorf("'%s' question '%s', returned an empty response", d.Address, question) + } + + if r.Rcode != dns.RcodeSuccess { + s := dns.RcodeToString[r.Rcode] + return nil, fmt.Errorf("'%s' question '%s' returned '%s' (%d) response code", d.Address, question, s, r.Rcode) + } + + return r, nil +} |