40 lines
926 B
Go
40 lines
926 B
Go
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//go:build !windows
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package dns
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import (
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"fmt"
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"os"
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"regexp"
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)
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var (
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// nameserver xxx.xxx.xxx.xxx
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nameserverPattern = regexp.MustCompile(`nameserver\s+(?P<ip>\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})`)
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)
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func loadSystemResolver() (clients []dnsClient, err error) {
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content, err := os.ReadFile("/etc/resolv.conf")
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if err != nil {
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err = fmt.Errorf("failed to read /etc/resolv.conf: %w", err)
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return
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}
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nameservers := make([]string, 0)
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for _, line := range nameserverPattern.FindAllStringSubmatch(string(content), -1) {
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addr := line[1]
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nameservers = append(nameservers, addr)
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}
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if len(nameservers) == 0 {
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err = fmt.Errorf("no nameserver found in /etc/resolv.conf")
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return
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}
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servers := make([]NameServer, 0, len(nameservers))
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for _, addr := range nameservers {
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servers = append(servers, NameServer{
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Addr: fmt.Sprintf("%s:%d", addr, 53),
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Net: "udp",
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})
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}
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return transform(servers, nil), nil
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}
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