1 /*
   2  * Copyright (c) 1994, 2013, 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 <stdlib.h>
  27 #include <string.h>
  28 #include <stddef.h>
  29 
  30 #include "jni.h"
  31 #include "jni_util.h"
  32 #include "jvm.h"
  33 #include "io_util.h"
  34 #include "io_util_md.h"
  35 
  36 /* IO helper functions */
  37 
  38 jint
  39 readSingle(JNIEnv *env, jobject this, jfieldID fid) {
  40     jint nread;
  41     char ret;
  42     FD fd = GET_FD(this, fid);
  43     if (fd == -1) {
  44         JNU_ThrowIOException(env, "Stream Closed");
  45         return -1;
  46     }
  47     nread = IO_Read(fd, &ret, 1);
  48     if (nread == 0) { /* EOF */
  49         return -1;
  50     } else if (nread == -1) { /* error */
  51         JNU_ThrowIOExceptionWithLastError(env, "Read error");
  52     }
  53     return ret & 0xFF;
  54 }
  55 
  56 /* The maximum size of a stack-allocated buffer.
  57  */
  58 #define BUF_SIZE 8192
  59 
  60 /*
  61  * Returns true if the array slice defined by the given offset and length
  62  * is out of bounds.
  63  */
  64 static int
  65 outOfBounds(JNIEnv *env, jint off, jint len, jbyteArray array) {
  66     return ((off < 0) ||
  67             (len < 0) ||
  68             // We are very careful to avoid signed integer overflow,
  69             // the result of which is undefined in C.
  70             ((*env)->GetArrayLength(env, array) - off < len));
  71 }
  72 
  73 jint
  74 readBytes(JNIEnv *env, jobject this, jbyteArray bytes,
  75           jint off, jint len, jfieldID fid)
  76 {
  77     jint nread;
  78     char stackBuf[BUF_SIZE];
  79     char *buf = NULL;
  80     FD fd;
  81 
  82     if (IS_NULL(bytes)) {
  83         JNU_ThrowNullPointerException(env, NULL);
  84         return -1;
  85     }
  86 
  87     if (outOfBounds(env, off, len, bytes)) {
  88         JNU_ThrowByName(env, "java/lang/IndexOutOfBoundsException", NULL);
  89         return -1;
  90     }
  91 
  92     if (len == 0) {
  93         return 0;
  94     } else if (len > BUF_SIZE) {
  95         buf = malloc(len);
  96         if (buf == NULL) {
  97             JNU_ThrowOutOfMemoryError(env, NULL);
  98             return 0;
  99         }
 100     } else {
 101         buf = stackBuf;
 102     }
 103 
 104     fd = GET_FD(this, fid);
 105     if (fd == -1) {
 106         JNU_ThrowIOException(env, "Stream Closed");
 107         nread = -1;
 108     } else {
 109         nread = IO_Read(fd, buf, len);
 110         if (nread > 0) {
 111             (*env)->SetByteArrayRegion(env, bytes, off, nread, (jbyte *)buf);
 112         } else if (nread == -1) {
 113             JNU_ThrowIOExceptionWithLastError(env, "Read error");
 114         } else { /* EOF */
 115             nread = -1;
 116         }
 117     }
 118 
 119     if (buf != stackBuf) {
 120         free(buf);
 121     }
 122     return nread;
 123 }
 124 
 125 void
 126 writeSingle(JNIEnv *env, jobject this, jint byte, jboolean append, jfieldID fid) {
 127     // Discard the 24 high-order bits of byte. See OutputStream#write(int)
 128     char c = (char) byte;
 129     jint n;
 130     FD fd = GET_FD(this, fid);
 131     if (fd == -1) {
 132         JNU_ThrowIOException(env, "Stream Closed");
 133         return;
 134     }
 135     if (append == JNI_TRUE) {
 136         n = IO_Append(fd, &c, 1);
 137     } else {
 138         n = IO_Write(fd, &c, 1);
 139     }
 140     if (n == -1) {
 141         JNU_ThrowIOExceptionWithLastError(env, "Write error");
 142     }
 143 }
 144 
 145 void
 146 writeBytes(JNIEnv *env, jobject this, jbyteArray bytes,
 147            jint off, jint len, jboolean append, jfieldID fid)
 148 {
 149     jint n;
 150     char stackBuf[BUF_SIZE];
 151     char *buf = NULL;
 152     FD fd;
 153 
 154     if (IS_NULL(bytes)) {
 155         JNU_ThrowNullPointerException(env, NULL);
 156         return;
 157     }
 158 
 159     if (outOfBounds(env, off, len, bytes)) {
 160         JNU_ThrowByName(env, "java/lang/IndexOutOfBoundsException", NULL);
 161         return;
 162     }
 163 
 164     if (len == 0) {
 165         return;
 166     } else if (len > BUF_SIZE) {
 167         buf = malloc(len);
 168         if (buf == NULL) {
 169             JNU_ThrowOutOfMemoryError(env, NULL);
 170             return;
 171         }
 172     } else {
 173         buf = stackBuf;
 174     }
 175 
 176     (*env)->GetByteArrayRegion(env, bytes, off, len, (jbyte *)buf);
 177 
 178     if (!(*env)->ExceptionOccurred(env)) {
 179         off = 0;
 180         while (len > 0) {
 181             fd = GET_FD(this, fid);
 182             if (fd == -1) {
 183                 JNU_ThrowIOException(env, "Stream Closed");
 184                 break;
 185             }
 186             if (append == JNI_TRUE) {
 187                 n = IO_Append(fd, buf+off, len);
 188             } else {
 189                 n = IO_Write(fd, buf+off, len);
 190             }
 191             if (n == -1) {
 192                 JNU_ThrowIOExceptionWithLastError(env, "Write error");
 193                 break;
 194             }
 195             off += n;
 196             len -= n;
 197         }
 198     }
 199     if (buf != stackBuf) {
 200         free(buf);
 201     }
 202 }
 203 
 204 void
 205 throwFileNotFoundException(JNIEnv *env, jstring path)
 206 {
 207     char buf[256];
 208     size_t n;
 209     jobject x;
 210     jstring why = NULL;
 211 
 212     n = getLastErrorString(buf, sizeof(buf));
 213     if (n > 0) {
 214 #ifdef WIN32 
 215         why = (*env)->NewStringUTF(env, buf);
 216 #else
 217         why = JNU_NewStringPlatform(env, buf);
 218 #endif
 219     }
 220     x = JNU_NewObjectByName(env,
 221                             "java/io/FileNotFoundException",
 222                             "(Ljava/lang/String;Ljava/lang/String;)V",
 223                             path, why);
 224     if (x != NULL) {
 225         (*env)->Throw(env, x);
 226     }
 227 }
--- EOF ---