unix: on linux use accept4 in Accept, fall back to accept

tklauser · tklauser · commit d19ff857e887 · 2021-04-26T23:07:00.000Z
Android seems to block the accept syscall in newer versions. Use accept4 instead on kernel versions that support it (Linux 2.6.28 and newer) and fall back to accept on ENOSYS. Updates golang/go#45767 Change-Id: If557eaaaa0b69112bbe66ed820fbb382afb53b04 Reviewed-on: https://go-review.googlesource.com/c/sys/+/313690 Trust: Tobias Klauser <tobias.klauser@gmail.com> Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
diff --git a/unix/syscall_linux.go b/unix/syscall_linux.go
@@ -1151,7 +1151,11 @@ func anyToSockaddr(fd int, rsa *RawSockaddrAny) (Sockaddr, error) {
 func Accept(fd int) (nfd int, sa Sockaddr, err error) {
 	var rsa RawSockaddrAny
 	var len _Socklen = SizeofSockaddrAny
-	nfd, err = accept(fd, &rsa, &len)
+	// Try accept4 first for Android, then try accept for kernel older than 2.6.28
+	nfd, err = accept4(fd, &rsa, &len, 0)
+	if err == ENOSYS {
+		nfd, err = accept(fd, &rsa, &len)
+	}
 	if err != nil {
 		return
 	}
