+ dnsforward: add access settings for blocking DNS requests

Block by client IP or target domain name.
This commit is contained in:
Simon Zolin 2019-05-24 14:49:26 +03:00
parent 147344afa3
commit 36ffcf7d22
2 changed files with 186 additions and 11 deletions

View File

@ -43,6 +43,12 @@ type Server struct {
stats *stats // General server statistics
once sync.Once
AllowedClients map[string]bool // IP addresses of whitelist clients
DisallowedClients map[string]bool // IP addresses of clients that should be blocked
AllowedClientsIPNet []net.IPNet // CIDRs of whitelist clients
DisallowedClientsIPNet []net.IPNet // CIDRs of clients that should be blocked
BlockedHosts map[string]bool // hosts that should be blocked
sync.RWMutex
conf ServerConfig
}
@ -70,6 +76,10 @@ type FilteringConfig struct {
BootstrapDNS []string `yaml:"bootstrap_dns"` // a list of bootstrap DNS for DoH and DoT (plain DNS only)
AllServers bool `yaml:"all_servers"` // if true, parallel queries to all configured upstream servers are enabled
AllowedClients []string `yaml:"allowed_clients"` // IP addresses of whitelist clients
DisallowedClients []string `yaml:"disallowed_clients"` // IP addresses of clients that should be blocked
BlockedHosts []string `yaml:"blocked_hosts"` // hosts that should be blocked
dnsfilter.Config `yaml:",inline"`
}
@ -121,6 +131,34 @@ func (s *Server) Start(config *ServerConfig) error {
return s.startInternal(config)
}
func convertArrayToMap(dst *map[string]bool, src []string) {
*dst = make(map[string]bool)
for _, s := range src {
(*dst)[s] = true
}
}
// Split array of IP or CIDR into 2 containers for fast search
func processIPCIDRArray(dst *map[string]bool, dstIPNet *[]net.IPNet, src []string) error {
*dst = make(map[string]bool)
for _, s := range src {
ip := net.ParseIP(s)
if ip != nil {
(*dst)[s] = true
continue
}
_, ipnet, err := net.ParseCIDR(s)
if err != nil {
return err
}
*dstIPNet = append(*dstIPNet, *ipnet)
}
return nil
}
// startInternal starts without locking
func (s *Server) startInternal(config *ServerConfig) error {
if config != nil {
@ -167,10 +205,23 @@ func (s *Server) startInternal(config *ServerConfig) error {
CacheEnabled: true,
Upstreams: s.conf.Upstreams,
DomainsReservedUpstreams: s.conf.DomainsReservedUpstreams,
Handler: s.handleDNSRequest,
BeforeRequestHandler: s.beforeRequestHandler,
RequestHandler: s.handleDNSRequest,
AllServers: s.conf.AllServers,
}
err = processIPCIDRArray(&s.AllowedClients, &s.AllowedClientsIPNet, s.conf.AllowedClients)
if err != nil {
return err
}
err = processIPCIDRArray(&s.DisallowedClients, &s.DisallowedClientsIPNet, s.conf.DisallowedClients)
if err != nil {
return err
}
convertArrayToMap(&s.BlockedHosts, s.conf.BlockedHosts)
if s.conf.TLSListenAddr != nil && s.conf.CertificateChain != "" && s.conf.PrivateKey != "" {
proxyConfig.TLSListenAddr = s.conf.TLSListenAddr
keypair, err := tls.X509KeyPair([]byte(s.conf.CertificateChain), []byte(s.conf.PrivateKey))
@ -321,6 +372,67 @@ func (s *Server) GetStatsHistory(timeUnit time.Duration, startTime time.Time, en
return s.stats.getStatsHistory(timeUnit, startTime, endTime)
}
// Return TRUE if this client should be blocked
func (s *Server) isBlockedIP(ip string) bool {
if len(s.AllowedClients) != 0 || len(s.AllowedClientsIPNet) != 0 {
_, ok := s.AllowedClients[ip]
if ok {
return false
}
if len(s.AllowedClientsIPNet) != 0 {
ipAddr := net.ParseIP(ip)
for _, ipnet := range s.AllowedClientsIPNet {
if ipnet.Contains(ipAddr) {
return false
}
}
}
return true
}
_, ok := s.DisallowedClients[ip]
if ok {
return true
}
if len(s.DisallowedClientsIPNet) != 0 {
ipAddr := net.ParseIP(ip)
for _, ipnet := range s.DisallowedClientsIPNet {
if ipnet.Contains(ipAddr) {
return true
}
}
}
return false
}
// Return TRUE if this domain should be blocked
func (s *Server) isBlockedDomain(host string) bool {
_, ok := s.BlockedHosts[host]
return ok
}
func (s *Server) beforeRequestHandler(p *proxy.Proxy, d *proxy.DNSContext) (bool, error) {
ip, _, _ := net.SplitHostPort(d.Addr.String())
if s.isBlockedIP(ip) {
log.Tracef("Client IP %s is blocked by settings", ip)
return false, nil
}
if len(d.Req.Question) == 1 {
host := strings.TrimSuffix(d.Req.Question[0].Name, ".")
if s.isBlockedDomain(host) {
log.Tracef("Domain %s is blocked by settings", host)
return false, nil
}
}
return true, nil
}
// handleDNSRequest filters the incoming DNS requests and writes them to the query log
func (s *Server) handleDNSRequest(p *proxy.Proxy, d *proxy.DNSContext) error {
start := time.Now()

View File

@ -15,12 +15,10 @@ import (
"testing"
"time"
"github.com/AdguardTeam/dnsproxy/proxy"
"github.com/stretchr/testify/assert"
"github.com/AdguardTeam/AdGuardHome/dnsfilter"
"github.com/AdguardTeam/dnsproxy/proxy"
"github.com/miekg/dns"
"github.com/stretchr/testify/assert"
)
const (
@ -460,12 +458,8 @@ func createTestServer(t *testing.T) *Server {
s.conf.FilteringConfig.SafeBrowsingEnabled = true
s.conf.Filters = make([]dnsfilter.Filter, 0)
rules := []string{
"||nxdomain.example.org^",
"||null.example.org^",
"127.0.0.1 host.example.org",
}
filter := dnsfilter.Filter{ID: 1, Rules: rules}
rules := "||nxdomain.example.org^\n||null.example.org^\n127.0.0.1 host.example.org\n"
filter := dnsfilter.Filter{ID: 1, Data: []byte(rules)}
s.conf.Filters = append(s.conf.Filters, filter)
return s
}
@ -628,3 +622,72 @@ func publicKey(priv interface{}) interface{} {
return nil
}
}
func TestIsBlockedIPAllowed(t *testing.T) {
s := createTestServer(t)
s.conf.AllowedClients = []string{"1.1.1.1", "2.2.0.0/16"}
err := s.Start(nil)
defer removeDataDir(t)
if err != nil {
t.Fatalf("Failed to start server: %s", err)
}
if s.isBlockedIP("1.1.1.1") {
t.Fatalf("isBlockedIP")
}
if !s.isBlockedIP("1.1.1.2") {
t.Fatalf("isBlockedIP")
}
if s.isBlockedIP("2.2.1.1") {
t.Fatalf("isBlockedIP")
}
if !s.isBlockedIP("2.3.1.1") {
t.Fatalf("isBlockedIP")
}
}
func TestIsBlockedIPDisallowed(t *testing.T) {
s := createTestServer(t)
s.conf.DisallowedClients = []string{"1.1.1.1", "2.2.0.0/16"}
err := s.Start(nil)
defer removeDataDir(t)
if err != nil {
t.Fatalf("Failed to start server: %s", err)
}
if !s.isBlockedIP("1.1.1.1") {
t.Fatalf("isBlockedIP")
}
if s.isBlockedIP("1.1.1.2") {
t.Fatalf("isBlockedIP")
}
if !s.isBlockedIP("2.2.1.1") {
t.Fatalf("isBlockedIP")
}
if s.isBlockedIP("2.3.1.1") {
t.Fatalf("isBlockedIP")
}
}
func TestIsBlockedIPBlockedDomain(t *testing.T) {
s := createTestServer(t)
s.conf.BlockedHosts = []string{"host1", "host2"}
err := s.Start(nil)
defer removeDataDir(t)
if err != nil {
t.Fatalf("Failed to start server: %s", err)
}
if !s.isBlockedDomain("host1") {
t.Fatalf("isBlockedDomain")
}
if !s.isBlockedDomain("host2") {
t.Fatalf("isBlockedDomain")
}
if s.isBlockedDomain("host3") {
t.Fatalf("isBlockedDomain")
}
}