mirror of
https://github.com/AdguardTeam/AdGuardHome.git
synced 2024-12-05 01:37:42 +03:00
138 lines
3.3 KiB
Go
138 lines
3.3 KiB
Go
package dnsforward
|
|
|
|
import (
|
|
"fmt"
|
|
"net"
|
|
"os"
|
|
"strings"
|
|
|
|
"github.com/AdguardTeam/AdGuardHome/internal/ipset"
|
|
"github.com/AdguardTeam/golibs/errors"
|
|
"github.com/AdguardTeam/golibs/log"
|
|
"github.com/miekg/dns"
|
|
)
|
|
|
|
// ipsetCtx is the ipset context. ipsetMgr can be nil.
|
|
type ipsetCtx struct {
|
|
ipsetMgr ipset.Manager
|
|
}
|
|
|
|
// init initializes the ipset context. It is not safe for concurrent use.
|
|
//
|
|
// TODO(a.garipov): Rewrite into a simple constructor?
|
|
func (c *ipsetCtx) init(ipsetConf []string) (err error) {
|
|
c.ipsetMgr, err = ipset.NewManager(ipsetConf)
|
|
if errors.Is(err, os.ErrInvalid) || errors.Is(err, os.ErrPermission) {
|
|
// ipset cannot currently be initialized if the server was installed
|
|
// from Snap or when the user or the binary doesn't have the required
|
|
// permissions, or when the kernel doesn't support netfilter.
|
|
//
|
|
// Log and go on.
|
|
//
|
|
// TODO(a.garipov): The Snap problem can probably be solved if we add
|
|
// the netlink-connector interface plug.
|
|
log.Info("ipset: warning: cannot initialize: %s", err)
|
|
|
|
return nil
|
|
} else if errors.Is(err, errors.ErrUnsupported) {
|
|
log.Info("ipset: warning: %s", err)
|
|
|
|
return nil
|
|
} else if err != nil {
|
|
return fmt.Errorf("initializing ipset: %w", err)
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
// close closes the Linux Netfilter connections.
|
|
func (c *ipsetCtx) close() (err error) {
|
|
if c.ipsetMgr != nil {
|
|
return c.ipsetMgr.Close()
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
func (c *ipsetCtx) dctxIsfilled(dctx *dnsContext) (ok bool) {
|
|
return dctx != nil &&
|
|
dctx.responseFromUpstream &&
|
|
dctx.proxyCtx != nil &&
|
|
dctx.proxyCtx.Res != nil &&
|
|
dctx.proxyCtx.Req != nil &&
|
|
len(dctx.proxyCtx.Req.Question) > 0
|
|
}
|
|
|
|
// skipIpsetProcessing returns true when the ipset processing can be skipped for
|
|
// this request.
|
|
func (c *ipsetCtx) skipIpsetProcessing(dctx *dnsContext) (ok bool) {
|
|
if c == nil || c.ipsetMgr == nil || !c.dctxIsfilled(dctx) {
|
|
return true
|
|
}
|
|
|
|
qtype := dctx.proxyCtx.Req.Question[0].Qtype
|
|
|
|
return qtype != dns.TypeA && qtype != dns.TypeAAAA && qtype != dns.TypeANY
|
|
}
|
|
|
|
// ipFromRR returns an IP address from a DNS resource record.
|
|
func ipFromRR(rr dns.RR) (ip net.IP) {
|
|
switch a := rr.(type) {
|
|
case *dns.A:
|
|
return a.A
|
|
case *dns.AAAA:
|
|
return a.AAAA
|
|
default:
|
|
return nil
|
|
}
|
|
}
|
|
|
|
// ipsFromAnswer returns IPv4 and IPv6 addresses from a DNS answer.
|
|
func ipsFromAnswer(ans []dns.RR) (ip4s, ip6s []net.IP) {
|
|
for _, rr := range ans {
|
|
ip := ipFromRR(rr)
|
|
if ip == nil {
|
|
continue
|
|
}
|
|
|
|
if ip.To4() == nil {
|
|
ip6s = append(ip6s, ip)
|
|
|
|
continue
|
|
}
|
|
|
|
ip4s = append(ip4s, ip)
|
|
}
|
|
|
|
return ip4s, ip6s
|
|
}
|
|
|
|
// process adds the resolved IP addresses to the domain's ipsets, if any.
|
|
func (c *ipsetCtx) process(dctx *dnsContext) (rc resultCode) {
|
|
log.Debug("dnsforward: ipset: started processing")
|
|
defer log.Debug("dnsforward: ipset: finished processing")
|
|
|
|
if c.skipIpsetProcessing(dctx) {
|
|
return resultCodeSuccess
|
|
}
|
|
|
|
log.Debug("ipset: starting processing")
|
|
|
|
req := dctx.proxyCtx.Req
|
|
host := req.Question[0].Name
|
|
host = strings.TrimSuffix(host, ".")
|
|
host = strings.ToLower(host)
|
|
|
|
ip4s, ip6s := ipsFromAnswer(dctx.proxyCtx.Res.Answer)
|
|
n, err := c.ipsetMgr.Add(host, ip4s, ip6s)
|
|
if err != nil {
|
|
// Consider ipset errors non-critical to the request.
|
|
log.Error("dnsforward: ipset: adding host ips: %s", err)
|
|
|
|
return resultCodeSuccess
|
|
}
|
|
|
|
log.Debug("dnsforward: ipset: added %d new ipset entries", n)
|
|
|
|
return resultCodeSuccess
|
|
}
|