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 }