1/*
2 * Copyright (c) 2001, 2017, 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#include "jni.h"
26#include "jni_util.h"
27#include "jvm.h"
28#include "io_util.h"
29#include "io_util_md.h"
30#include <string.h>
31#include <unistd.h>
32
33#ifdef __solaris__
34#include <sys/filio.h>
35#endif
36
37#if defined(__linux__) || defined(_ALLBSD_SOURCE) || defined(_AIX)
38#include <sys/ioctl.h>
39#endif
40
41#ifdef MACOSX
42
43#include <CoreFoundation/CoreFoundation.h>
44
45__private_extern__
46jstring newStringPlatform(JNIEnv *env, const char* str)
47{
48    jstring rv = NULL;
49    CFMutableStringRef csref = CFStringCreateMutable(NULL, 0);
50    if (csref == NULL) {
51        JNU_ThrowOutOfMemoryError(env, "native heap");
52    } else {
53        CFStringAppendCString(csref, str, kCFStringEncodingUTF8);
54        CFStringNormalize(csref, kCFStringNormalizationFormC);
55        int clen = CFStringGetLength(csref);
56        int ulen = (clen + 1) * 2;        // utf16 + zero padding
57        char* chars = malloc(ulen);
58        if (chars == NULL) {
59            CFRelease(csref);
60            JNU_ThrowOutOfMemoryError(env, "native heap");
61        } else {
62            if (CFStringGetCString(csref, chars, ulen, kCFStringEncodingUTF16)) {
63                rv = (*env)->NewString(env, (jchar*)chars, clen);
64            }
65            free(chars);
66            CFRelease(csref);
67        }
68    }
69    return rv;
70}
71#endif
72
73FD
74handleOpen(const char *path, int oflag, int mode) {
75    FD fd;
76    RESTARTABLE(open64(path, oflag, mode), fd);
77    if (fd != -1) {
78        struct stat64 buf64;
79        int result;
80        RESTARTABLE(fstat64(fd, &buf64), result);
81        if (result != -1) {
82            if (S_ISDIR(buf64.st_mode)) {
83                close(fd);
84                errno = EISDIR;
85                fd = -1;
86            }
87        } else {
88            close(fd);
89            fd = -1;
90        }
91    }
92    return fd;
93}
94
95void
96fileOpen(JNIEnv *env, jobject this, jstring path, jfieldID fid, int flags)
97{
98    WITH_PLATFORM_STRING(env, path, ps) {
99        FD fd;
100
101#if defined(__linux__) || defined(_ALLBSD_SOURCE)
102        /* Remove trailing slashes, since the kernel won't */
103        char *p = (char *)ps + strlen(ps) - 1;
104        while ((p > ps) && (*p == '/'))
105            *p-- = '\0';
106#endif
107        fd = handleOpen(ps, flags, 0666);
108        if (fd != -1) {
109            jobject fdobj;
110            jboolean append;
111            SET_FD(this, fd, fid);
112
113            fdobj = (*env)->GetObjectField(env, this, fid);
114            if (fdobj != NULL) {
115                append = (flags & O_APPEND) == 0 ? JNI_FALSE : JNI_TRUE;
116                (*env)->SetBooleanField(env, fdobj, IO_append_fdID, append);
117            }
118        } else {
119            throwFileNotFoundException(env, path);
120        }
121    } END_PLATFORM_STRING(env, ps);
122}
123
124void
125fileClose(JNIEnv *env, jobject this, jfieldID fid)
126{
127    FD fd = GET_FD(this, fid);
128    if (fd == -1) {
129        return;
130    }
131
132    /* Set the fd to -1 before closing it so that the timing window
133     * of other threads using the wrong fd (closed but recycled fd,
134     * that gets re-opened with some other filename) is reduced.
135     * Practically the chance of its occurance is low, however, we are
136     * taking extra precaution over here.
137     */
138    SET_FD(this, -1, fid);
139
140    /*
141     * Don't close file descriptors 0, 1, or 2. If we close these stream
142     * then a subsequent file open or socket will use them. Instead we
143     * just redirect these file descriptors to /dev/null.
144     */
145    if (fd >= STDIN_FILENO && fd <= STDERR_FILENO) {
146        int devnull = open("/dev/null", O_WRONLY);
147        if (devnull < 0) {
148            SET_FD(this, fd, fid); // restore fd
149            JNU_ThrowIOExceptionWithLastError(env, "open /dev/null failed");
150        } else {
151            dup2(devnull, fd);
152            close(devnull);
153        }
154    } else if (close(fd) == -1) {
155        JNU_ThrowIOExceptionWithLastError(env, "close failed");
156    }
157}
158
159ssize_t
160handleRead(FD fd, void *buf, jint len)
161{
162    ssize_t result;
163    RESTARTABLE(read(fd, buf, len), result);
164    return result;
165}
166
167ssize_t
168handleWrite(FD fd, const void *buf, jint len)
169{
170    ssize_t result;
171    RESTARTABLE(write(fd, buf, len), result);
172    return result;
173}
174
175jint
176handleAvailable(FD fd, jlong *pbytes)
177{
178    int mode;
179    struct stat64 buf64;
180    jlong size = -1, current = -1;
181
182    int result;
183    RESTARTABLE(fstat64(fd, &buf64), result);
184    if (result != -1) {
185        mode = buf64.st_mode;
186        if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
187            int n;
188            int result;
189            RESTARTABLE(ioctl(fd, FIONREAD, &n), result);
190            if (result >= 0) {
191                *pbytes = n;
192                return 1;
193            }
194        } else if (S_ISREG(mode)) {
195            size = buf64.st_size;
196        }
197    }
198
199    if ((current = lseek64(fd, 0, SEEK_CUR)) == -1) {
200        return 0;
201    }
202
203    if (size < current) {
204        if ((size = lseek64(fd, 0, SEEK_END)) == -1)
205            return 0;
206        else if (lseek64(fd, current, SEEK_SET) == -1)
207            return 0;
208    }
209
210    *pbytes = size - current;
211    return 1;
212}
213
214jint
215handleSetLength(FD fd, jlong length)
216{
217    int result;
218#if defined(__linux__)
219    /*
220     * On Linux, if the file size is being increased, then ftruncate64()
221     * will modify the metadata value of the size without actually allocating
222     * any blocks which can cause a SIGBUS error if the file is subsequently
223     * memory-mapped.
224     */
225    struct stat64 sb;
226
227    if (fstat64(fd, &sb) == 0 && length > sb.st_blocks*512) {
228        RESTARTABLE(fallocate64(fd, 0, 0, length), result);
229        // Return on success or if errno is neither EOPNOTSUPP nor ENOSYS
230        if (result == 0) {
231            return 0;
232        } else if (errno != EOPNOTSUPP && errno != ENOSYS) {
233            return result;
234        }
235    }
236#endif
237    RESTARTABLE(ftruncate64(fd, length), result);
238    return result;
239}
240
241jlong
242handleGetLength(FD fd)
243{
244    struct stat64 sb;
245    if (fstat64(fd, &sb) == 0) {
246        return sb.st_size;
247    } else {
248        return -1;
249    }
250}
251