92 lines
2.2 KiB
Go
92 lines
2.2 KiB
Go
package main
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import (
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"errors"
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"strings"
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"github.com/miekg/dns"
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"github.com/mr-karan/doggo/pkg/resolvers"
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"github.com/sirupsen/logrus"
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)
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// Lookup sends the DNS queries to the server.
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func (hub *Hub) Lookup() error {
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err := hub.prepareQuestions()
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if err != nil {
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return err
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}
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// for each type of resolver do a DNS lookup
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responses := make([][]resolvers.Response, 0, len(hub.Questions))
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for _, r := range hub.Resolver {
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resp, err := r.Lookup(hub.Questions)
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if err != nil {
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return err
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}
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responses = append(responses, resp)
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}
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if len(responses) == 0 {
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return errors.New(`no DNS records found`)
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}
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hub.Output(responses)
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return nil
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}
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// prepareQuestions iterates on list of domain names
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// and prepare a list of questions
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// sent to the server with all possible combinations.
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func (hub *Hub) prepareQuestions() error {
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var (
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question dns.Question
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)
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for _, name := range hub.QueryFlags.QNames {
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var (
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domains []string
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ndots int
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)
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ndots = hub.QueryFlags.Ndots
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// If `search` flag is specified then fetch the search list
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// from `resolv.conf` and set the
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if hub.QueryFlags.UseSearchList {
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list, n, err := fetchDomainList(name, ndots)
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if err != nil {
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return err
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}
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domains = list
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ndots = n
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} else {
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domains = []string{dns.Fqdn(name)}
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}
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for _, d := range domains {
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hub.Logger.WithFields(logrus.Fields{
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"domain": d,
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"ndots": ndots,
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}).Debug("Attmepting to resolve")
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question.Name = d
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// iterate on a list of query types.
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for _, q := range hub.QueryFlags.QTypes {
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question.Qtype = dns.StringToType[strings.ToUpper(q)]
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// iterate on a list of query classes.
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for _, c := range hub.QueryFlags.QClasses {
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question.Qclass = dns.StringToClass[strings.ToUpper(c)]
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// append a new question for each possible pair.
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hub.Questions = append(hub.Questions, question)
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}
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}
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}
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}
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return nil
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}
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func fetchDomainList(d string, ndots int) ([]string, int, error) {
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cfg, err := dns.ClientConfigFromFile(DefaultResolvConfPath)
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if err != nil {
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return nil, 0, err
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}
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// if it's the default value
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if cfg.Ndots == 1 {
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// override what the user gave. If the user didn't give any setting then it's 1 by default.
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cfg.Ndots = ndots
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}
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return cfg.NameList(d), cfg.Ndots, nil
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}
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