syncthing-android/patches/golang/all/dns.patch

diff --git a/net/dnsclient_unix.go b/net/dnsclient_unix.go
index 17188f0..15a1663 100644
--- a/net/dnsclient_unix.go
+++ b/net/dnsclient_unix.go
@@ -279,12 +279,6 @@ func (conf *resolverConfig) tryUpdate(name string) {
 			return
 		}
 		conf.modTime = fi.ModTime()
-	} else {
-		// If modTime wasn't set prior, assume nothing has changed.
-		if conf.modTime.IsZero() {
-			return
-		}
-		conf.modTime = time.Time{}
 	}
 
 	dnsConf := dnsReadConfig(name)
diff --git a/net/dnsconfig_unix.go b/net/dnsconfig_unix.go
index 6073fdb..bd6ca41 100644
--- a/net/dnsconfig_unix.go
+++ b/net/dnsconfig_unix.go
@@ -8,7 +8,53 @@
 
 package net
 
-var defaultNS = []string{"127.0.0.1", "::1"}
+import (
+	"fmt"
+	"os/exec"
+	"strings"
+)
+
+var currentNS []string
+
+func getDefaultNS() []string {
+	var servers []string
+	for _, prop := range []string{"net.dns1", "net.dns2"} {
+		cmd := exec.Command("getprop", prop)
+		outputBytes, err := cmd.Output()
+		if err != nil {
+			continue
+		}
+		output := strings.Trim(string(outputBytes), "\n")
+		if ParseIP(output) != nil {
+			servers = append(servers, output)
+		}
+	}
+
+	if len(servers) == 0 {
+		servers = []string{"8.8.8.8", "8.8.4.4", "4.2.2.1"}
+	}
+
+	if !slicesEqual(currentNS, servers) {
+		fmt.Println("Using DNS servers:", servers)
+		currentNS = servers
+	}
+
+	return currentNS
+}
+
+func slicesEqual(a, b []string) bool {
+	if len(a) != len(b) {
+		return false
+	}
+
+	for i := range a {
+		if a[i] != b[i] {
+			return false
+		}
+	}
+
+	return true
+}
 
 type dnsConfig struct {
 	servers    []string // servers to use
@@ -33,7 +79,7 @@ func dnsReadConfig(filename string) *dnsConfig {
 	}
 	file, err := open(filename)
 	if err != nil {
-		conf.servers = defaultNS
+		conf.servers = getDefaultNS()
 		conf.err = err
 		return conf
 	}
@@ -110,7 +156,7 @@ func dnsReadConfig(filename string) *dnsConfig {
 		}
 	}
 	if len(conf.servers) == 0 {
-		conf.servers = defaultNS
+		conf.servers = getDefaultNS()
 	}
 	return conf
 }