8299593: getprotobyname should not be used

Reviewed-by: cjplummer

Author: djelinski

src/jdk.jdwp.agent/unix/native/libdt_socket/socket_md.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1998, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1998, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -189,11 +189,9 @@ int
 dbgsysSetSocketOption(int fd, jint cmd, jboolean on, jvalue value)
 {
     if (cmd == TCP_NODELAY) {
-        struct protoent *proto = getprotobyname("TCP");
-        int tcp_level = (proto == 0 ? IPPROTO_TCP: proto->p_proto);
         uint32_t onl = (uint32_t)on;
 
-        if (setsockopt(fd, tcp_level, TCP_NODELAY,
+        if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY,
                        (char *)&onl, sizeof(uint32_t)) < 0) {
                 return SYS_ERR;
         }

src/jdk.jdwp.agent/windows/native/libdt_socket/socket_md.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1998, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1998, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -268,11 +268,9 @@ int
 dbgsysSetSocketOption(int fd, jint cmd, jboolean on, jvalue value)
 {
     if (cmd == TCP_NODELAY) {
-        struct protoent *proto = getprotobyname("TCP");
-        int tcp_level = (proto == 0 ? IPPROTO_TCP: proto->p_proto);
         long onl = (long)on;
 
-        if (setsockopt(fd, tcp_level, TCP_NODELAY,
+        if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY,
                        (char *)&onl, sizeof(long)) < 0) {
                 return SYS_ERR;
         }