1 /*
   2  * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 #include "jni.h"
  27 #include "jni_util.h"
  28 #include "jvm.h"
  29 #include "jlong.h"
  30 
  31 #include <dlfcn.h>
  32 #include <string.h>
  33 
  34 #define MAGIC_MIME_TYPE 0x000010 /* Return the MIME type */
  35 
  36 typedef struct magic_set magic_t;
  37 
  38 typedef magic_t* (*magic_open_func)(int flags);
  39 typedef int (*magic_load_func)(magic_t* cookie, const char* filename);
  40 typedef const char* (*magic_file_func)(magic_t* cookie, const char* filename);
  41 typedef void (*magic_close_func)(magic_t* cookie);
  42 
  43 static void* magic_handle;
  44 static magic_open_func magic_open;
  45 static magic_load_func magic_load;
  46 static magic_file_func magic_file;
  47 static magic_close_func magic_close;
  48 
  49 #include "sun_nio_fs_MagicFileTypeDetector.h"
  50 
  51 JNIEXPORT jboolean JNICALL
  52 Java_sun_nio_fs_MagicFileTypeDetector_initialize0
  53     (JNIEnv* env, jclass this)
  54 {
  55     magic_handle = dlopen("libmagic.so", RTLD_LAZY);
  56     if (magic_handle == NULL) {
  57         magic_handle = dlopen("libmagic.so.1", RTLD_LAZY);
  58         if (magic_handle == NULL) {
  59             return JNI_FALSE;
  60         }
  61     }
  62 
  63     magic_open = (magic_open_func)dlsym(magic_handle, "magic_open");
  64 
  65     magic_load = (magic_load_func)dlsym(magic_handle, "magic_load");
  66 
  67     magic_file = (magic_file_func)dlsym(magic_handle, "magic_file");
  68 
  69     magic_close = (magic_close_func)dlsym(magic_handle, "magic_close");
  70 
  71     if (magic_open == NULL ||
  72         magic_load == NULL ||
  73         magic_file == NULL ||
  74         magic_close == NULL)
  75     {
  76         dlclose(magic_handle);
  77         return JNI_FALSE;
  78     }
  79 
  80     return JNI_TRUE;
  81 }
  82 
  83 JNIEXPORT jbyteArray JNICALL
  84 Java_sun_nio_fs_MagicFileTypeDetector_probe0
  85     (JNIEnv* env, jclass this, jlong pathAddress)
  86 {
  87     char* path = (char*)jlong_to_ptr(pathAddress);
  88     magic_t* cookie;
  89     jbyteArray result = NULL;
  90 
  91     cookie = (*magic_open)(MAGIC_MIME_TYPE);
  92 
  93     if (cookie != NULL) {
  94         if ((*magic_load)(cookie, NULL) != -1) {
  95             const char* type = (*magic_file)(cookie, path);
  96             if (type != NULL) {
  97                 jsize len = strlen(type);
  98                 result = (*env)->NewByteArray(env, len);
  99                 if (result != NULL) {
 100                     (*env)->SetByteArrayRegion(env, result, 0, len, (jbyte*)type);
 101                 }
 102             }
 103         }
 104         (*magic_close)(cookie);
 105     }
 106 
 107     return result;
 108 }