1 /*
2 * Copyright (c) 2000, 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 #if defined(__linux__)
27 #define _FILE_OFFSET_BITS 64
28 #endif
29
30 #include "jni.h"
31 #include "jni_util.h"
32 #include "jvm.h"
33 #include "jlong.h"
34 #include "sun_nio_ch_FileDispatcherImpl.h"
35 #include "java_lang_Long.h"
36 #include <sys/types.h>
37 #include <sys/socket.h>
38 #include <fcntl.h>
39 #include <sys/uio.h>
40 #include <unistd.h>
41 #if defined(__linux__)
42 #include <linux/fs.h>
43 #include <sys/ioctl.h>
44 #endif
45 #include "nio.h"
46 #include "nio_util.h"
47
48 #ifdef _ALLBSD_SOURCE
49 #define stat64 stat
50 #define flock64 flock
51 #define off64_t off_t
52 #define F_SETLKW64 F_SETLKW
53 #define F_SETLK64 F_SETLK
54
55 #define pread64 pread
56 #define pwrite64 pwrite
57 #define ftruncate64 ftruncate
58 #define fstat64 fstat
59
60 #define fdatasync fsync
61 #endif
62
63 static int preCloseFD = -1; /* File descriptor to which we dup other fd's
64 before closing them for real */
65
66
67 JNIEXPORT void JNICALL
68 Java_sun_nio_ch_FileDispatcherImpl_init(JNIEnv *env, jclass cl)
69 {
70 int sp[2];
71 if (socketpair(PF_UNIX, SOCK_STREAM, 0, sp) < 0) {
72 JNU_ThrowIOExceptionWithLastError(env, "socketpair failed");
73 return;
74 }
75 preCloseFD = sp[0];
76 close(sp[1]);
77 }
78
79 JNIEXPORT jint JNICALL
80 Java_sun_nio_ch_FileDispatcherImpl_read0(JNIEnv *env, jclass clazz,
81 jobject fdo, jlong address, jint len)
82 {
83 jint fd = fdval(env, fdo);
84 void *buf = (void *)jlong_to_ptr(address);
85
86 return convertReturnVal(env, read(fd, buf, len), JNI_TRUE);
87 }
88
89 JNIEXPORT jint JNICALL
90 Java_sun_nio_ch_FileDispatcherImpl_pread0(JNIEnv *env, jclass clazz, jobject fdo,
91 jlong address, jint len, jlong offset)
92 {
93 jint fd = fdval(env, fdo);
94 void *buf = (void *)jlong_to_ptr(address);
95
96 return convertReturnVal(env, pread64(fd, buf, len, offset), JNI_TRUE);
97 }
98
99 JNIEXPORT jlong JNICALL
100 Java_sun_nio_ch_FileDispatcherImpl_readv0(JNIEnv *env, jclass clazz,
101 jobject fdo, jlong address, jint len)
102 {
103 jint fd = fdval(env, fdo);
104 struct iovec *iov = (struct iovec *)jlong_to_ptr(address);
105 return convertLongReturnVal(env, readv(fd, iov, len), JNI_TRUE);
106 }
107
108 JNIEXPORT jint JNICALL
109 Java_sun_nio_ch_FileDispatcherImpl_write0(JNIEnv *env, jclass clazz,
110 jobject fdo, jlong address, jint len)
111 {
112 jint fd = fdval(env, fdo);
113 void *buf = (void *)jlong_to_ptr(address);
114
115 return convertReturnVal(env, write(fd, buf, len), JNI_FALSE);
116 }
117
118 JNIEXPORT jint JNICALL
119 Java_sun_nio_ch_FileDispatcherImpl_pwrite0(JNIEnv *env, jclass clazz, jobject fdo,
120 jlong address, jint len, jlong offset)
121 {
122 jint fd = fdval(env, fdo);
123 void *buf = (void *)jlong_to_ptr(address);
124
125 return convertReturnVal(env, pwrite64(fd, buf, len, offset), JNI_FALSE);
126 }
127
128 JNIEXPORT jlong JNICALL
129 Java_sun_nio_ch_FileDispatcherImpl_writev0(JNIEnv *env, jclass clazz,
130 jobject fdo, jlong address, jint len)
131 {
132 jint fd = fdval(env, fdo);
133 struct iovec *iov = (struct iovec *)jlong_to_ptr(address);
134 return convertLongReturnVal(env, writev(fd, iov, len), JNI_FALSE);
135 }
136
137 static jlong
138 handle(JNIEnv *env, jlong rv, char *msg)
139 {
140 if (rv >= 0)
141 return rv;
142 if (errno == EINTR)
143 return IOS_INTERRUPTED;
144 JNU_ThrowIOExceptionWithLastError(env, msg);
145 return IOS_THROWN;
146 }
147
148 JNIEXPORT jint JNICALL
149 Java_sun_nio_ch_FileDispatcherImpl_force0(JNIEnv *env, jobject this,
150 jobject fdo, jboolean md)
151 {
152 jint fd = fdval(env, fdo);
153 int result = 0;
154
155 if (md == JNI_FALSE) {
156 result = fdatasync(fd);
157 } else {
158 #ifdef _AIX
159 /* On AIX, calling fsync on a file descriptor that is opened only for
160 * reading results in an error ("EBADF: The FileDescriptor parameter is
161 * not a valid file descriptor open for writing.").
162 * However, at this point it is not possibly anymore to read the
163 * 'writable' attribute of the corresponding file channel so we have to
164 * use 'fcntl'.
165 */
166 int getfl = fcntl(fd, F_GETFL);
167 if (getfl >= 0 && (getfl & O_ACCMODE) == O_RDONLY) {
168 return 0;
169 }
170 #endif
171 result = fsync(fd);
172 }
173 return handle(env, result, "Force failed");
174 }
175
176 JNIEXPORT jint JNICALL
177 Java_sun_nio_ch_FileDispatcherImpl_truncate0(JNIEnv *env, jobject this,
178 jobject fdo, jlong size)
179 {
180 return handle(env,
181 ftruncate64(fdval(env, fdo), size),
182 "Truncation failed");
183 }
184
185 JNIEXPORT jint JNICALL
186 Java_sun_nio_ch_FileDispatcherImpl_allocate0(JNIEnv *env, jobject this,
187 jobject fdo, jlong size)
188 {
189 #if defined(__linux__)
190 /*
191 * On Linux, if the file size is being increased, then ftruncate64()
192 * will modify the metadata value of the size without actually allocating
193 * any blocks which can cause a SIGBUS error if the file is subsequently
194 * memory-mapped.
195 */
196 // Return on success or if errno is neither EOPNOTSUPP nor ENOSYS
197 int result = posix_fallocate(fdval(env, fdo), 0, size);
198 if (result == 0) {
199 return 0;
200 } else if (errno != EOPNOTSUPP && errno != ENOSYS) {
201 return handle(env, result, "Allocation failed");
202 }
203 #endif
204 return handle(env,
205 ftruncate64(fdval(env, fdo), size),
206 "Truncation failed");
207 }
208
209 JNIEXPORT jlong JNICALL
210 Java_sun_nio_ch_FileDispatcherImpl_size0(JNIEnv *env, jobject this, jobject fdo)
211 {
212 jint fd = fdval(env, fdo);
213 struct stat64 fbuf;
214
215 if (fstat64(fd, &fbuf) < 0)
216 return handle(env, -1, "Size failed");
217
218 #ifdef BLKGETSIZE64
219 if (S_ISBLK(fbuf.st_mode)) {
220 uint64_t size;
221 if (ioctl(fd, BLKGETSIZE64, &size) < 0)
222 return handle(env, -1, "Size failed");
223 return (jlong)size;
224 }
225 #endif
226
227 return fbuf.st_size;
228 }
229
230 JNIEXPORT jint JNICALL
231 Java_sun_nio_ch_FileDispatcherImpl_lock0(JNIEnv *env, jobject this, jobject fdo,
232 jboolean block, jlong pos, jlong size,
233 jboolean shared)
234 {
235 jint fd = fdval(env, fdo);
236 jint lockResult = 0;
237 int cmd = 0;
238 struct flock64 fl;
239
240 fl.l_whence = SEEK_SET;
241 if (size == (jlong)java_lang_Long_MAX_VALUE) {
242 fl.l_len = (off64_t)0;
243 } else {
244 fl.l_len = (off64_t)size;
245 }
246 fl.l_start = (off64_t)pos;
247 if (shared == JNI_TRUE) {
248 fl.l_type = F_RDLCK;
249 } else {
250 fl.l_type = F_WRLCK;
251 }
252 if (block == JNI_TRUE) {
253 cmd = F_SETLKW64;
254 } else {
255 cmd = F_SETLK64;
256 }
257 lockResult = fcntl(fd, cmd, &fl);
258 if (lockResult < 0) {
259 if ((cmd == F_SETLK64) && (errno == EAGAIN || errno == EACCES))
260 return sun_nio_ch_FileDispatcherImpl_NO_LOCK;
261 if (errno == EINTR)
262 return sun_nio_ch_FileDispatcherImpl_INTERRUPTED;
263 JNU_ThrowIOExceptionWithLastError(env, "Lock failed");
264 }
265 return 0;
266 }
267
268 JNIEXPORT void JNICALL
269 Java_sun_nio_ch_FileDispatcherImpl_release0(JNIEnv *env, jobject this,
270 jobject fdo, jlong pos, jlong size)
271 {
272 jint fd = fdval(env, fdo);
273 jint lockResult = 0;
274 struct flock64 fl;
275 int cmd = F_SETLK64;
276
277 fl.l_whence = SEEK_SET;
278 if (size == (jlong)java_lang_Long_MAX_VALUE) {
279 fl.l_len = (off64_t)0;
280 } else {
281 fl.l_len = (off64_t)size;
282 }
283 fl.l_start = (off64_t)pos;
284 fl.l_type = F_UNLCK;
285 lockResult = fcntl(fd, cmd, &fl);
286 if (lockResult < 0) {
287 JNU_ThrowIOExceptionWithLastError(env, "Release failed");
288 }
289 }
290
291
292 static void closeFileDescriptor(JNIEnv *env, int fd) {
293 if (fd != -1) {
294 int result = close(fd);
295 if (result < 0)
296 JNU_ThrowIOExceptionWithLastError(env, "Close failed");
297 }
298 }
299
300 JNIEXPORT void JNICALL
301 Java_sun_nio_ch_FileDispatcherImpl_close0(JNIEnv *env, jclass clazz, jobject fdo)
302 {
303 jint fd = fdval(env, fdo);
304 closeFileDescriptor(env, fd);
305 }
306
307 JNIEXPORT void JNICALL
308 Java_sun_nio_ch_FileDispatcherImpl_preClose0(JNIEnv *env, jclass clazz, jobject fdo)
309 {
310 jint fd = fdval(env, fdo);
311 if (preCloseFD >= 0) {
312 if (dup2(preCloseFD, fd) < 0)
313 JNU_ThrowIOExceptionWithLastError(env, "dup2 failed");
314 }
315 }
316
317 JNIEXPORT void JNICALL
318 Java_sun_nio_ch_FileDispatcherImpl_closeIntFD(JNIEnv *env, jclass clazz, jint fd)
319 {
320 closeFileDescriptor(env, fd);
321 }