58 lines
1.1 KiB
Go
58 lines
1.1 KiB
Go
// SPDX-License-Identifier: BSD-3-Clause
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//go:build plan9
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package conf
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import (
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"errors"
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"fmt"
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"os"
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"strings"
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"github.com/miekg/dns"
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)
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// GetDNSConfig gets DNS information from Plan 9, because it's different from UNIX and Windows.
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//
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// Plan 9 stores its network data in /net/ndb, which seems to be formatted a specific way
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// Yoink it and use it.
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//
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// See ndb(7).
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func GetDNSConfig() (*dns.ClientConfig, error) {
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dat, err := os.ReadFile("/net/ndb")
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if err != nil {
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return nil, fmt.Errorf("read ndb: %w", err)
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}
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str := string(dat)
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str = strings.ReplaceAll(str, "\n", "")
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spl := strings.FieldsFunc(str, splitChars)
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var servers []string
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for _, option := range spl {
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if strings.HasPrefix(option, "dns=") {
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servers = append(servers, strings.TrimPrefix(option, "dns="))
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}
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}
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if len(servers) == 0 {
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return nil, errPlan9
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}
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// TODO: read more about how customizable Plan 9 is
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return &dns.ClientConfig{
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Servers: servers,
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Search: []string{},
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Port: "53",
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}, nil
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}
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// Split the string at either space or tabs.
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func splitChars(r rune) bool {
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return r == ' ' || r == '\t'
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}
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var errPlan9 = errors.New("plan9Config: no DNS servers found")
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