Adding support for tcnative fedora flavour in uber jar

Motivation:

We want to allow the use of an uber jar that contains shared dynamic libraries for all platforms (including fedora).

Modifications:

Modified OpenSsl to try and load the fedora library if the OS is Linux and the platform specified library fails before using the default lib.

Result:

True uber support.

common/src/main/java/io/netty/util/internal/NativeLibraryLoader.java

@@ -24,6 +24,7 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.net.URL;
+import java.util.Arrays;
 import java.util.Locale;
 
 /**
@@ -147,6 +148,26 @@ public final class NativeLibraryLoader {
         return OSNAME.startsWith("macosx") || OSNAME.startsWith("osx");
     }
 
+    /**
+     * Loads the first available library in the collection with the specified
+     * {@link ClassLoader}.
+     *
+     * @throws IllegalArgumentException
+     *         if none of the given libraries load successfully.
+     */
+    public static void loadFirstAvailable(ClassLoader loader, String... names) {
+        for (String name : names) {
+            try {
+                NativeLibraryLoader.load(name, loader);
+                return;
+            } catch (Throwable t) {
+                logger.debug("Unable to load the library: " + name + '.', t);
+            }
+        }
+        throw new IllegalArgumentException("Failed to load any of the given libraries: "
+                                           + Arrays.toString(names));
+    }
+
     /**
      * Load the given library with the specified {@link java.lang.ClassLoader}
      */

handler/src/main/java/io/netty/handler/ssl/OpenSsl.java

@@ -39,6 +39,7 @@ import java.util.Set;
 public final class OpenSsl {
 
     private static final InternalLogger logger = InternalLoggerFactory.getInstance(OpenSsl.class);
+    private static final String LINUX = "linux";
     private static final String UNKNOWN = "unknown";
     private static final Throwable UNAVAILABILITY_CAUSE;
 
@@ -62,19 +63,20 @@ public final class OpenSsl {
             try {
                 String os = normalizeOs(SystemPropertyUtil.get("os.name", ""));
                 String arch = normalizeArch(SystemPropertyUtil.get("os.arch", ""));
-                String libName = "netty-tcnative-" + os + '-' + arch;
-                try {
-                    // First, try loading the platform-specific library. Platform-specific
-                    // libraries will be available if using a tcnative uber jar.
-                    NativeLibraryLoader.load(libName, SSL.class.getClassLoader());
-                } catch (Throwable t) {
-                    // Either the uber jar isn't on classpath, or it doesn't contain a library
-                    // for this platform. Load the default library.
-                    logger.debug("Unable to load platform-specific netty-tcnative library: " +
-                        libName + ". Will attempt to load the default netty-tcnative library.", t);
 
-                    NativeLibraryLoader.load("netty-tcnative", SSL.class.getClassLoader());
+                Set<String> libNames = new LinkedHashSet<String>(3);
+                // First, try loading the platform-specific library. Platform-specific
+                // libraries will be available if using a tcnative uber jar.
+                libNames.add("netty-tcnative-" + os + '-' + arch);
+                if (LINUX.equalsIgnoreCase(os)) {
+                    // Fedora SSL lib so naming (libssl.so.10 vs libssl.so.1.0.0)..
+                    libNames.add("netty-tcnative-" + os + '-' + arch + "-fedora");
                 }
+                // finally the default library.
+                libNames.add("netty-tcnative");
+
+                NativeLibraryLoader.loadFirstAvailable(SSL.class.getClassLoader(),
+                        libNames.toArray(new String[libNames.size()]));
 
                 Library.initialize("provided");
                 SSL.initialize(null);
@@ -231,8 +233,8 @@ public final class OpenSsl {
                 return "os400";
             }
         }
-        if (value.startsWith("linux")) {
+        if (value.startsWith(LINUX)) {
-            return "linux";
+            return LINUX;
         }
         if (value.startsWith("macosx") || value.startsWith("osx")) {
             return "osx";