mirror of
https://github.com/netbirdio/netbird.git
synced 2024-12-03 13:34:41 +01:00
17b1099032
* Fix using wrong array index in log to avoid potential panic * Increase gRPC connection timeout and add the timeout resolv.conf option This makes sure the dns client is able to failover to a second configured nameserver, if present. That is the case then when using the dns `file` manager and a resolv.conf file generated for netbird. * On file backup restore, remove the first NS if it's the netbird NS * Bump dns mangager discovery message from debug to info to ease debugging
109 lines
3.0 KiB
Go
109 lines
3.0 KiB
Go
//go:build !android
|
|
|
|
package dns
|
|
|
|
import (
|
|
"bytes"
|
|
"fmt"
|
|
"net/netip"
|
|
"os/exec"
|
|
|
|
log "github.com/sirupsen/logrus"
|
|
)
|
|
|
|
const resolvconfCommand = "resolvconf"
|
|
|
|
type resolvconf struct {
|
|
ifaceName string
|
|
|
|
originalSearchDomains []string
|
|
originalNameServers []string
|
|
othersConfigs []string
|
|
}
|
|
|
|
// supported "openresolv" only
|
|
func newResolvConfConfigurator(wgInterface string) (hostManager, error) {
|
|
resolvConfEntries, err := parseDefaultResolvConf()
|
|
if err != nil {
|
|
log.Errorf("could not read original search domains from %s: %s", defaultResolvConfPath, err)
|
|
}
|
|
|
|
return &resolvconf{
|
|
ifaceName: wgInterface,
|
|
originalSearchDomains: resolvConfEntries.searchDomains,
|
|
originalNameServers: resolvConfEntries.nameServers,
|
|
othersConfigs: resolvConfEntries.others,
|
|
}, nil
|
|
}
|
|
|
|
func (r *resolvconf) supportCustomPort() bool {
|
|
return false
|
|
}
|
|
|
|
func (r *resolvconf) applyDNSConfig(config HostDNSConfig) error {
|
|
var err error
|
|
if !config.RouteAll {
|
|
err = r.restoreHostDNS()
|
|
if err != nil {
|
|
log.Errorf("restore host dns: %s", err)
|
|
}
|
|
return fmt.Errorf("unable to configure DNS for this peer using resolvconf manager without a nameserver group with all domains configured")
|
|
}
|
|
|
|
searchDomainList := searchDomains(config)
|
|
searchDomainList = mergeSearchDomains(searchDomainList, r.originalSearchDomains)
|
|
|
|
options := prepareOptionsWithTimeout(r.othersConfigs, int(dnsFailoverTimeout.Seconds()), dnsFailoverAttempts)
|
|
|
|
buf := prepareResolvConfContent(
|
|
searchDomainList,
|
|
append([]string{config.ServerIP}, r.originalNameServers...),
|
|
options)
|
|
|
|
// create a backup for unclean shutdown detection before the resolv.conf is changed
|
|
if err := createUncleanShutdownIndicator(defaultResolvConfPath, resolvConfManager, config.ServerIP); err != nil {
|
|
log.Errorf("failed to create unclean shutdown resolv.conf backup: %s", err)
|
|
}
|
|
|
|
err = r.applyConfig(buf)
|
|
if err != nil {
|
|
return fmt.Errorf("apply config: %w", err)
|
|
}
|
|
|
|
log.Infof("added %d search domains. Search list: %s", len(searchDomainList), searchDomainList)
|
|
return nil
|
|
}
|
|
|
|
func (r *resolvconf) restoreHostDNS() error {
|
|
// openresolv only, debian resolvconf doesn't support "-f"
|
|
cmd := exec.Command(resolvconfCommand, "-f", "-d", r.ifaceName)
|
|
_, err := cmd.Output()
|
|
if err != nil {
|
|
return fmt.Errorf("removing resolvconf configuration for %s interface, error: %w", r.ifaceName, err)
|
|
}
|
|
|
|
if err := removeUncleanShutdownIndicator(); err != nil {
|
|
log.Errorf("failed to remove unclean shutdown resolv.conf backup: %s", err)
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
func (r *resolvconf) applyConfig(content bytes.Buffer) error {
|
|
// openresolv only, debian resolvconf doesn't support "-x"
|
|
cmd := exec.Command(resolvconfCommand, "-x", "-a", r.ifaceName)
|
|
cmd.Stdin = &content
|
|
_, err := cmd.Output()
|
|
if err != nil {
|
|
return fmt.Errorf("applying resolvconf configuration for %s interface, error: %w", r.ifaceName, err)
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func (r *resolvconf) restoreUncleanShutdownDNS(*netip.Addr) error {
|
|
if err := r.restoreHostDNS(); err != nil {
|
|
return fmt.Errorf("restoring dns for interface %s: %w", r.ifaceName, err)
|
|
}
|
|
return nil
|
|
}
|