mirror of
https://github.com/Control-D-Inc/ctrld.git
synced 2026-02-03 22:18:39 +00:00
97 lines
2.2 KiB
Go
97 lines
2.2 KiB
Go
package clientinfo
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import (
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"os"
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"sync"
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"github.com/fsnotify/fsnotify"
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"github.com/jaytaylor/go-hostsfile"
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"github.com/Control-D-Inc/ctrld"
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)
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// hostsFile provides client discovery functionality using system hosts file.
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type hostsFile struct {
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watcher *fsnotify.Watcher
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mu sync.Mutex
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m map[string][]string
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}
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// init performs initialization works, which is necessary before hostsFile can be fully operated.
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func (hf *hostsFile) init() error {
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watcher, err := fsnotify.NewWatcher()
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if err != nil {
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return err
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}
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hf.watcher = watcher
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if err := hf.watcher.Add(hostsfile.HostsPath); err != nil {
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return err
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}
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m, err := hostsfile.ParseHosts(hostsfile.ReadHostsFile())
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if err != nil {
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return err
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}
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hf.mu.Lock()
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hf.m = m
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hf.mu.Unlock()
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return nil
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}
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// refresh reloads hosts file entries.
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func (hf *hostsFile) refresh() error {
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m, err := hostsfile.ParseHosts(hostsfile.ReadHostsFile())
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if err != nil {
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return err
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}
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hf.mu.Lock()
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hf.m = m
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hf.mu.Unlock()
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return nil
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}
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// watchChanges watches and updates hosts file data if any changes happens.
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func (hf *hostsFile) watchChanges() {
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if hf.watcher == nil {
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return
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}
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for {
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select {
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case event, ok := <-hf.watcher.Events:
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if !ok {
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return
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}
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if event.Has(fsnotify.Write) || event.Has(fsnotify.Rename) || event.Has(fsnotify.Chmod) || event.Has(fsnotify.Remove) {
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if err := hf.refresh(); err != nil && !os.IsNotExist(err) {
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ctrld.ProxyLogger.Load().Err(err).Msg("hosts file changed but failed to update client info")
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}
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}
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case err, ok := <-hf.watcher.Errors:
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if !ok {
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return
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}
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ctrld.ProxyLogger.Load().Err(err).Msg("could not watch client info file")
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}
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}
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}
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// LookupHostnameByIP returns hostname for given IP from current hosts file entries.
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func (hf *hostsFile) LookupHostnameByIP(ip string) string {
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hf.mu.Lock()
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defer hf.mu.Unlock()
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if names := hf.m[ip]; len(names) > 0 {
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return normalizeHostname(names[0])
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}
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return ""
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}
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// LookupHostnameByMac returns hostname for given Mac from current hosts file entries.
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func (hf *hostsFile) LookupHostnameByMac(mac string) string {
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return ""
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}
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// String returns human-readable format of hostsFile.
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func (hf *hostsFile) String() string {
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return "hosts"
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}
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