awl/conf/plan9.go
Sam Therapy 7314122951
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more modular
Signed-off-by: Sam Therapy <sam@samtherapy.net>
2022-08-31 02:48:57 +02:00

56 lines
1.1 KiB
Go

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