1 /*
2 * Copyright (c) 1994, 2018, 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
54 JVM_callFileReadBytes(env, 1);
55
56 return ret & 0xFF;
57 }
58
59 /* The maximum size of a stack-allocated buffer.
60 */
61 #define BUF_SIZE 8192
62
63 /*
64 * Returns true if the array slice defined by the given offset and length
65 * is out of bounds.
66 */
67 static int
68 outOfBounds(JNIEnv *env, jint off, jint len, jbyteArray array) {
69 return ((off < 0) ||
70 (len < 0) ||
71 // We are very careful to avoid signed integer overflow,
72 // the result of which is undefined in C.
73 ((*env)->GetArrayLength(env, array) - off < len));
74 }
75
76 jint
77 readBytes(JNIEnv *env, jobject this, jbyteArray bytes,
78 jint off, jint len, jfieldID fid)
79 {
80 jint nread;
81 char stackBuf[BUF_SIZE];
82 char *buf = NULL;
83 FD fd;
84
85 if (IS_NULL(bytes)) {
86 JNU_ThrowNullPointerException(env, NULL);
87 return -1;
88 }
89
90 if (outOfBounds(env, off, len, bytes)) {
91 JNU_ThrowByName(env, "java/lang/IndexOutOfBoundsException", NULL);
92 return -1;
93 }
94
95 if (len == 0) {
96 return 0;
97 } else if (len > BUF_SIZE) {
98 buf = malloc(len);
99 if (buf == NULL) {
100 JNU_ThrowOutOfMemoryError(env, NULL);
101 return 0;
102 }
103 } else {
104 buf = stackBuf;
105 }
106
107 fd = GET_FD(this, fid);
108 if (fd == -1) {
109 JNU_ThrowIOException(env, "Stream Closed");
110 nread = -1;
111 } else {
112 nread = IO_Read(fd, buf, len);
113 if (nread > 0) {
114 (*env)->SetByteArrayRegion(env, bytes, off, nread, (jbyte *)buf);
115 JVM_callFileReadBytes(env, nread);
116 } else if (nread == -1) {
117 JNU_ThrowIOExceptionWithLastError(env, "Read error");
118 } else { /* EOF */
119 nread = -1;
120 }
121 }
122
123 if (buf != stackBuf) {
124 free(buf);
125 }
126 return nread;
127 }
128
129 void
130 writeSingle(JNIEnv *env, jobject this, jint byte, jboolean append, jfieldID fid) {
131 // Discard the 24 high-order bits of byte. See OutputStream#write(int)
132 char c = (char) byte;
133 jint n;
134 FD fd = GET_FD(this, fid);
135 if (fd == -1) {
136 JNU_ThrowIOException(env, "Stream Closed");
137 return;
138 }
139 if (append == JNI_TRUE) {
140 n = IO_Append(fd, &c, 1);
141 } else {
142 n = IO_Write(fd, &c, 1);
143 }
144 if (n == -1) {
145 JNU_ThrowIOExceptionWithLastError(env, "Write error");
146 }
147 JVM_callFileWriteBytes(env, 1);
148 }
149
150 void
151 writeBytes(JNIEnv *env, jobject this, jbyteArray bytes,
152 jint off, jint len, jboolean append, jfieldID fid)
153 {
154 jint n;
155 char stackBuf[BUF_SIZE];
156 char *buf = NULL;
157 FD fd;
158
159 if (IS_NULL(bytes)) {
160 JNU_ThrowNullPointerException(env, NULL);
161 return;
162 }
163
164 if (outOfBounds(env, off, len, bytes)) {
165 JNU_ThrowByName(env, "java/lang/IndexOutOfBoundsException", NULL);
166 return;
167 }
168
169 if (len == 0) {
170 return;
171 } else if (len > BUF_SIZE) {
172 buf = malloc(len);
173 if (buf == NULL) {
174 JNU_ThrowOutOfMemoryError(env, NULL);
175 return;
176 }
177 } else {
178 buf = stackBuf;
179 }
180
181 (*env)->GetByteArrayRegion(env, bytes, off, len, (jbyte *)buf);
182
183 if (!(*env)->ExceptionOccurred(env)) {
184 off = 0;
185 while (len > 0) {
186 fd = GET_FD(this, fid);
187 if (fd == -1) {
188 JNU_ThrowIOException(env, "Stream Closed");
189 break;
190 }
191 if (append == JNI_TRUE) {
192 n = IO_Append(fd, buf+off, len);
193 } else {
194 n = IO_Write(fd, buf+off, len);
195 }
196 if (n == -1) {
197 JNU_ThrowIOExceptionWithLastError(env, "Write error");
198 break;
199 }
200 off += n;
201 len -= n;
202 }
203 JVM_callFileWriteBytes(env, off);
204 }
205 if (buf != stackBuf) {
206 free(buf);
207 }
208 }
209
210 void
211 throwFileNotFoundException(JNIEnv *env, jstring path)
212 {
213 char buf[256];
214 size_t n;
215 jobject x;
216 jstring why = NULL;
217
218 n = getLastErrorString(buf, sizeof(buf));
219 if (n > 0) {
220 why = JNU_NewStringPlatform(env, buf);
221 CHECK_NULL(why);
222 }
223 x = JNU_NewObjectByName(env,
224 "java/io/FileNotFoundException",
225 "(Ljava/lang/String;Ljava/lang/String;)V",
226 path, why);
227 if (x != NULL) {
228 (*env)->Throw(env, x);
229 }
230 }