mirror of
https://github.com/Control-D-Inc/ctrld.git
synced 2026-02-03 22:18:39 +00:00
f0cb810dd6
Make nameserver resolution functions more consistent and accessible: - Rename currentNameserversFromResolvconf to CurrentNameserversFromResolvconf - Move function to public API for better reusability - Update all internal references to use the new public API - Add comprehensive godoc comments for nameserver functions - Improve code organization by centralizing DNS resolution logic This change makes the nameserver resolution functionality more maintainable and easier to use across different parts of the codebase.
115 lines
3.2 KiB
Go
115 lines
3.2 KiB
Go
package cli
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import (
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"bufio"
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"bytes"
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"fmt"
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"net"
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"os/exec"
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"strings"
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"github.com/Control-D-Inc/ctrld"
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)
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// allocate loopback ip
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// sudo ifconfig lo0 alias 127.0.0.2 up
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func allocateIP(ip string) error {
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cmd := exec.Command("ifconfig", "lo0", "alias", ip, "up")
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if err := cmd.Run(); err != nil {
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mainLog.Load().Error().Err(err).Msg("allocateIP failed")
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return err
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}
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return nil
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}
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func deAllocateIP(ip string) error {
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cmd := exec.Command("ifconfig", "lo0", "-alias", ip)
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if err := cmd.Run(); err != nil {
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mainLog.Load().Error().Err(err).Msg("deAllocateIP failed")
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return err
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}
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return nil
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}
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// setDnsIgnoreUnusableInterface likes setDNS, but return a nil error if the interface is not usable.
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func setDnsIgnoreUnusableInterface(iface *net.Interface, nameservers []string) error {
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if err := setDNS(iface, nameservers); err != nil {
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// TODO: investiate whether we can detect this without relying on error message.
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if strings.Contains(err.Error(), " is not a recognized network service") {
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return nil
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}
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return err
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}
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return nil
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}
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// set the dns server for the provided network interface
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// networksetup -setdnsservers Wi-Fi 8.8.8.8 1.1.1.1
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// TODO(cuonglm): use system API
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func setDNS(iface *net.Interface, nameservers []string) error {
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// Note that networksetup won't modify search domains settings,
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// This assignment is just a placeholder to silent linter.
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_ = searchDomains
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cmd := "networksetup"
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args := []string{"-setdnsservers", iface.Name}
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args = append(args, nameservers...)
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if out, err := exec.Command(cmd, args...).CombinedOutput(); err != nil {
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return fmt.Errorf("%v: %w", string(out), err)
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}
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return nil
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}
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// resetDnsIgnoreUnusableInterface likes resetDNS, but return a nil error if the interface is not usable.
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func resetDnsIgnoreUnusableInterface(iface *net.Interface) error {
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if err := resetDNS(iface); err != nil {
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// TODO: investiate whether we can detect this without relying on error message.
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if strings.Contains(err.Error(), " is not a recognized network service") {
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return nil
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}
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return err
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}
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return nil
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}
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// TODO(cuonglm): use system API
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func resetDNS(iface *net.Interface) error {
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cmd := "networksetup"
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args := []string{"-setdnsservers", iface.Name, "empty"}
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if out, err := exec.Command(cmd, args...).CombinedOutput(); err != nil {
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return fmt.Errorf("%v: %w", string(out), err)
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}
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return nil
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}
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// restoreDNS restores the DNS settings of the given interface.
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// this should only be executed upon turning off the ctrld service.
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func restoreDNS(iface *net.Interface) (err error) {
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if ns := ctrld.SavedStaticNameservers(iface); len(ns) > 0 {
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err = setDNS(iface, ns)
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}
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return err
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}
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func currentDNS(_ *net.Interface) []string {
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return ctrld.CurrentNameserversFromResolvconf()
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}
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// currentStaticDNS returns the current static DNS settings of given interface.
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func currentStaticDNS(iface *net.Interface) ([]string, error) {
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cmd := "networksetup"
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args := []string{"-getdnsservers", iface.Name}
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out, err := exec.Command(cmd, args...).Output()
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if err != nil {
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return nil, err
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}
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scanner := bufio.NewScanner(bytes.NewReader(out))
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var ns []string
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for scanner.Scan() {
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line := scanner.Text()
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if ip := net.ParseIP(line); ip != nil {
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ns = append(ns, ip.String())
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}
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}
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return ns, nil
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}
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