| 1 | // SPDX-License-Identifier: GPL-3.0-or-later |
| 2 | |
| 3 | package dnsquery |
| 4 | |
| 5 | import ( |
| 6 | "math/rand" |
| 7 | "net" |
| 8 | "strconv" |
| 9 | "sync" |
| 10 | "time" |
| 11 | |
| 12 | "github.com/miekg/dns" |
| 13 | ) |
| 14 | |
| 15 | func (c *Collector) collect() (map[string]int64, error) { |
| 16 | if c.dnsClient == nil { |
| 17 | c.dnsClient = c.newDNSClient(c.Network, c.Timeout.Duration()) |
| 18 | } |
| 19 | |
| 20 | mx := make(map[string]int64) |
| 21 | domain := randomDomain(c.Domains) |
| 22 | c.Debugf("current domain : %s", domain) |
| 23 | |
| 24 | var wg sync.WaitGroup |
| 25 | var mux sync.RWMutex |
| 26 | for _, srv := range c.Servers { |
| 27 | for rtypeName, rtype := range c.recordTypes { |
| 28 | wg.Add(1) |
| 29 | go func(srv, rtypeName string, rtype uint16, wg *sync.WaitGroup) { |
| 30 | defer wg.Done() |
| 31 | |
| 32 | msg := new(dns.Msg) |
| 33 | msg.SetQuestion(dns.Fqdn(domain), rtype) |
| 34 | address := net.JoinHostPort(srv, strconv.Itoa(c.Port)) |
| 35 | |
| 36 | resp, rtt, err := c.dnsClient.Exchange(msg, address) |
| 37 | |
| 38 | mux.Lock() |
| 39 | defer mux.Unlock() |
| 40 | |
| 41 | px := "server_" + srv + "_record_" + rtypeName + "_" |
| 42 | |
| 43 | mx[px+"query_status_success"] = 0 |
| 44 | mx[px+"query_status_network_error"] = 0 |
| 45 | mx[px+"query_status_dns_error"] = 0 |
| 46 | |
| 47 | if err != nil { |
| 48 | c.Debugf("error on querying %s after %s query for %s : %s", srv, rtypeName, domain, err) |
| 49 | mx[px+"query_status_network_error"] = 1 |
| 50 | return |
| 51 | } |
| 52 | |
| 53 | if resp != nil && resp.Rcode != dns.RcodeSuccess { |
| 54 | c.Debugf("invalid answer from %s after %s query for %s (rcode %d)", srv, rtypeName, domain, resp.Rcode) |
| 55 | mx[px+"query_status_dns_error"] = 1 |
| 56 | } else { |
| 57 | mx[px+"query_status_success"] = 1 |
| 58 | } |
| 59 | mx["server_"+srv+"_record_"+rtypeName+"_query_time"] = rtt.Nanoseconds() |
| 60 | |
| 61 | }(srv, rtypeName, rtype, &wg) |
| 62 | } |
| 63 | } |
| 64 | wg.Wait() |
| 65 | |
| 66 | return mx, nil |
| 67 | } |
| 68 | |
| 69 | func randomDomain(domains []string) string { |
| 70 | src := rand.NewSource(time.Now().UnixNano()) |
| 71 | r := rand.New(src) |
| 72 | return domains[r.Intn(len(domains))] |
| 73 | } |