1 /*
2 * Copyright (C) 2008 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 //#define LOG_NDEBUG 0
18
19 #include "JNIHelp.h"
20
21 #include <fcntl.h>
22 #include <sys/stat.h>
23 #include <stdio.h>
24
25 #include <utils/Log.h>
26
27 #include <android_runtime/AndroidRuntime.h>
28
29 namespace android
30 {
31
32 static struct file_descriptor_offsets_t
33 {
34 jclass mClass;
35 jmethodID mConstructor;
36 jfieldID mDescriptor;
37 } gFileDescriptorOffsets;
38
39 static struct socket_offsets_t
40 {
41 jfieldID mSocketImpl;
42 } gSocketOffsets;
43
44 static struct socket_impl_offsets_t
45 {
46 jfieldID mFileDescriptor;
47 } gSocketImplOffsets;
48
49 static struct parcel_file_descriptor_offsets_t
50 {
51 jclass mClass;
52 jfieldID mFileDescriptor;
53 } gParcelFileDescriptorOffsets;
54
android_os_ParcelFileDescriptor_getFileDescriptorFromSocket(JNIEnv * env,jobject clazz,jobject object)55 static jobject android_os_ParcelFileDescriptor_getFileDescriptorFromSocket(JNIEnv* env,
56 jobject clazz, jobject object)
57 {
58 jobject socketImpl = env->GetObjectField(object, gSocketOffsets.mSocketImpl);
59 jobject fileDescriptor = env->GetObjectField(socketImpl, gSocketImplOffsets.mFileDescriptor);
60 jint fd = env->GetIntField(fileDescriptor, gFileDescriptorOffsets.mDescriptor);
61 jobject fileDescriptorClone = env->NewObject(gFileDescriptorOffsets.mClass,
62 gFileDescriptorOffsets.mConstructor);
63 if (fileDescriptorClone != NULL) {
64 env->SetIntField(fileDescriptorClone, gFileDescriptorOffsets.mDescriptor, dup(fd));
65 }
66 return fileDescriptorClone;
67 }
68
getFd(JNIEnv * env,jobject clazz)69 static jint getFd(JNIEnv* env, jobject clazz)
70 {
71 jobject descriptor = env->GetObjectField(clazz, gParcelFileDescriptorOffsets.mFileDescriptor);
72 if (descriptor == NULL) return -1;
73 return env->GetIntField(descriptor, gFileDescriptorOffsets.mDescriptor);
74 }
75
android_os_ParcelFileDescriptor_getStatSize(JNIEnv * env,jobject clazz)76 static jlong android_os_ParcelFileDescriptor_getStatSize(JNIEnv* env,
77 jobject clazz)
78 {
79 jint fd = getFd(env, clazz);
80 if (fd < 0) {
81 jniThrowException(env, "java/lang/IllegalArgumentException", "bad file descriptor");
82 return -1;
83 }
84
85 struct stat st;
86 if (fstat(fd, &st) != 0) {
87 return -1;
88 }
89
90 if (S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)) {
91 return st.st_size;
92 }
93
94 return -1;
95 }
96
android_os_ParcelFileDescriptor_seekTo(JNIEnv * env,jobject clazz,jlong pos)97 static jlong android_os_ParcelFileDescriptor_seekTo(JNIEnv* env,
98 jobject clazz, jlong pos)
99 {
100 jint fd = getFd(env, clazz);
101 if (fd < 0) {
102 jniThrowException(env, "java/lang/IllegalArgumentException", "bad file descriptor");
103 return -1;
104 }
105
106 return lseek(fd, pos, SEEK_SET);
107 }
108
109 static const JNINativeMethod gParcelFileDescriptorMethods[] = {
110 {"getFileDescriptorFromSocket", "(Ljava/net/Socket;)Ljava/io/FileDescriptor;",
111 (void*)android_os_ParcelFileDescriptor_getFileDescriptorFromSocket},
112 {"getStatSize", "()J",
113 (void*)android_os_ParcelFileDescriptor_getStatSize},
114 {"seekTo", "(J)J",
115 (void*)android_os_ParcelFileDescriptor_seekTo}
116 };
117
118 const char* const kParcelFileDescriptorPathName = "android/os/ParcelFileDescriptor";
119
register_android_os_ParcelFileDescriptor(JNIEnv * env)120 int register_android_os_ParcelFileDescriptor(JNIEnv* env)
121 {
122 jclass clazz;
123
124 clazz = env->FindClass("java/net/Socket");
125 LOG_FATAL_IF(clazz == NULL, "Unable to find class java.net.Socket");
126 gSocketOffsets.mSocketImpl = env->GetFieldID(clazz, "impl", "Ljava/net/SocketImpl;");
127 LOG_FATAL_IF(gSocketOffsets.mSocketImpl == NULL,
128 "Unable to find impl field in java.net.Socket");
129
130 clazz = env->FindClass("java/net/SocketImpl");
131 LOG_FATAL_IF(clazz == NULL, "Unable to find class java.net.SocketImpl");
132 gSocketImplOffsets.mFileDescriptor = env->GetFieldID(clazz, "fd", "Ljava/io/FileDescriptor;");
133 LOG_FATAL_IF(gSocketImplOffsets.mFileDescriptor == NULL,
134 "Unable to find fd field in java.net.SocketImpl");
135
136 clazz = env->FindClass("java/io/FileDescriptor");
137 LOG_FATAL_IF(clazz == NULL, "Unable to find class java.io.FileDescriptor");
138 gFileDescriptorOffsets.mClass = (jclass) env->NewGlobalRef(clazz);
139 gFileDescriptorOffsets.mConstructor = env->GetMethodID(clazz, "<init>", "()V");
140 gFileDescriptorOffsets.mDescriptor = env->GetFieldID(clazz, "descriptor", "I");
141 LOG_FATAL_IF(gFileDescriptorOffsets.mDescriptor == NULL,
142 "Unable to find descriptor field in java.io.FileDescriptor");
143
144 clazz = env->FindClass(kParcelFileDescriptorPathName);
145 LOG_FATAL_IF(clazz == NULL, "Unable to find class android.os.ParcelFileDescriptor");
146 gParcelFileDescriptorOffsets.mClass = (jclass) env->NewGlobalRef(clazz);
147 gParcelFileDescriptorOffsets.mFileDescriptor = env->GetFieldID(clazz, "mFileDescriptor", "Ljava/io/FileDescriptor;");
148 LOG_FATAL_IF(gParcelFileDescriptorOffsets.mFileDescriptor == NULL,
149 "Unable to find mFileDescriptor field in android.os.ParcelFileDescriptor");
150
151 return AndroidRuntime::registerNativeMethods(
152 env, kParcelFileDescriptorPathName,
153 gParcelFileDescriptorMethods, NELEM(gParcelFileDescriptorMethods));
154 }
155
156 }
157