Pull request 258: 5874-openwrt-setsockopt

Merge in GO/dnsproxy from 5874-openwrt-setsockopt to master Squashed commit of the following: commit 8897679 Author: Ainar Garipov <[email protected]> Date: Thu Jun 8 12:27:17 2023 +0300 netutil: warn about setsockopt fail
AdguardTeam · Jun 8, 2023 · 20fd473 · 20fd473
1 parent af10111
commit 20fd473
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Showing 2 changed files with 14 additions and 1 deletion.
diff --git a/internal/netutil/listenconfig.go b/internal/netutil/listenconfig.go
@@ -7,6 +7,11 @@ import "net"
 //
 // TODO(a.garipov): Add tests.
 //
+// TODO(a.garipov): Add an option to not set SO_REUSEPORT on Unix to prevent
+// issues with OpenWrt.
+//
+// See https://github.com/AdguardTeam/AdGuardHome/issues/5872.
+//
 // TODO(a.garipov): DRY with AdGuard DNS when we can.
 func ListenConfig() (lc *net.ListenConfig) {
 	return &net.ListenConfig{

diff --git a/internal/netutil/listenconfig_unix.go b/internal/netutil/listenconfig_unix.go
@@ -7,6 +7,7 @@ import (
 	"syscall"
 
 	"github.com/AdguardTeam/golibs/errors"
+	"github.com/AdguardTeam/golibs/log"
 	"golang.org/x/sys/unix"
 )
 
@@ -25,7 +26,14 @@ func defaultListenControl(_, _ string, c syscall.RawConn) (err error) {
 
 		opErr = unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_REUSEPORT, 1)
 		if opErr != nil {
-			opErr = fmt.Errorf("setting SO_REUSEPORT: %w", opErr)
+			if errors.Is(opErr, unix.ENOPROTOOPT) {
+				// Some Linux OSs do not seem to support SO_REUSEPORT, including
+				// some varieties of OpenWrt.  Issue a warning.
+				log.Info("warning: SO_REUSEPORT not supported: %s", opErr)
+				opErr = nil
+			} else {
+				opErr = fmt.Errorf("setting SO_REUSEPORT: %w", opErr)
+			}
 		}
 	})