8201369: Inet4AddressImpl_getLocalHostName reverse lookup on Solaris only

Reviewed-by: clanger, chegar
Contributed-by: sshamaia@in.ibm.com

src/solaris/native/java/net/Inet4AddressImpl.c

@@ -67,38 +67,36 @@ extern jobjectArray lookupIfLocalhost(JNIEnv *env, const char *hostname, jboolea
  */
 JNIEXPORT jstring JNICALL
 Java_java_net_Inet4AddressImpl_getLocalHostName(JNIEnv *env, jobject this) {
-    char hostname[NI_MAXHOST+1];
+    char hostname[NI_MAXHOST + 1];
 
     hostname[0] = '\0';
     if (JVM_GetHostName(hostname, NI_MAXHOST)) {
-        /* Something went wrong, maybe networking is not setup? */
         strcpy(hostname, "localhost");
+#if defined(__solaris__)
     } else {
+        // try to resolve hostname via nameservice
+        // if it is known but getnameinfo fails, hostname will still be the
+        // value from gethostname
         struct addrinfo hints, *res;
-         int error;
 
+        // make sure string is null-terminated
+        hostname[NI_MAXHOST] = '\0';
         memset(&hints, 0, sizeof(hints));
         hints.ai_flags = AI_CANONNAME;
-         hints.ai_family = AF_UNSPEC;
-
-         error = getaddrinfo(hostname, NULL, &hints, &res);
-
-         if (error == 0) {
-             /* host is known to name service */
-             error = getnameinfo(res->ai_addr,
-                                 res->ai_addrlen,
-                                 hostname,
-                                 NI_MAXHOST,
-                                 NULL,
-                                 0,
-                                 NI_NAMEREQD);
-
-             /* if getnameinfo fails hostname is still the value
-                from gethostname */
+        hints.ai_family = AF_INET;
 
+        if (getaddrinfo(hostname, NULL, &hints, &res) == 0) {
+            getnameinfo(res->ai_addr, res->ai_addrlen, hostname, NI_MAXHOST,
+                        NULL, 0, NI_NAMEREQD);
             freeaddrinfo(res);
         }
     }
+#else
+    } else {
+        // make sure string is null-terminated
+        hostname[NI_MAXHOST] = '\0';
+    }
+#endif
     return (*env)->NewStringUTF(env, hostname);
 }
 

src/solaris/native/java/net/Inet6AddressImpl.c

@@ -66,49 +66,36 @@
  */
 JNIEXPORT jstring JNICALL
 Java_java_net_Inet6AddressImpl_getLocalHostName(JNIEnv *env, jobject this) {
-    char hostname[NI_MAXHOST+1];
+    char hostname[NI_MAXHOST + 1];
 
     hostname[0] = '\0';
     if (JVM_GetHostName(hostname, sizeof(hostname))) {
-        /* Something went wrong, maybe networking is not setup? */
         strcpy(hostname, "localhost");
-    } else {
-        // ensure null-terminated
-        hostname[NI_MAXHOST] = '\0';
-
-        /* Solaris doesn't want to give us a fully qualified domain name.
-         * We do a reverse lookup to try and get one.  This works
-         * if DNS occurs before NIS in /etc/resolv.conf, but fails
-         * if NIS comes first (it still gets only a partial name).
-         * We use thread-safe system calls.
-         */
 #if defined(__solaris__) && defined(AF_INET6)
+    } else {
+        // try to resolve hostname via nameservice
+        // if it is known but getnameinfo fails, hostname will still be the
+        // value from gethostname
         struct addrinfo hints, *res;
-        int error;
 
+        // make sure string is null-terminated
+        hostname[NI_MAXHOST] = '\0';
         memset(&hints, 0, sizeof(hints));
         hints.ai_flags = AI_CANONNAME;
         hints.ai_family = AF_UNSPEC;
 
-        error = getaddrinfo(hostname, NULL, &hints, &res);
-
-        if (error == 0) {
-            /* host is known to name service */
-            error = getnameinfo(res->ai_addr,
-                                res->ai_addrlen,
-                                hostname,
-                                NI_MAXHOST,
-                                NULL,
-                                0,
-                                NI_NAMEREQD);
-
-            /* if getnameinfo fails hostname is still the value
-               from gethostname */
-
+        if (getaddrinfo(hostname, NULL, &hints, &res) == 0) {
+            getnameinfo(res->ai_addr, res->ai_addrlen, hostname, NI_MAXHOST,
+                        NULL, 0, NI_NAMEREQD);
             freeaddrinfo(res);
         }
-#endif
     }
+#else
+    } else {
+        // make sure string is null-terminated
+        hostname[NI_MAXHOST] = '\0';
+    }
+#endif
     return (*env)->NewStringUTF(env, hostname);
 }